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Zeng Q, Chen J, Li Y, Werle KD, Zhao RX, Quan CS, Wang YS, Zhai YX, Wang JW, Youssef M, Cui R, Liang J, Genovese N, Chow LT, Li YL, Xu ZX. LKB1 inhibits HPV-associated cancer progression by targeting cellular metabolism. Oncogene 2016; 36:1245-1255. [PMID: 27546620 PMCID: PMC5322260 DOI: 10.1038/onc.2016.290] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/04/2016] [Accepted: 07/05/2016] [Indexed: 12/14/2022]
Abstract
Liver kinase B1 (LKB1) is mutationally inactivated in Peutz-Jeghers syndrome and in a variety of cancers including human papillomavirus (HPV)-caused cervical cancer. However, the significance of LKB1 mutations in cervical cancer initiation and progress has not been examined. Herein, we demonstrated that, in mouse embryonic fibroblasts, loss of LKB1 and transduction of HPV16 E6/E7 had an additive effect on constraining cell senescence while promoting cell proliferation and increasing glucose consumption, lactate production, and ATP generation. Knock-down of LKB1 increased and ectopic expression of LKB1 decreased glycolysis, anchorage-independent cell growth, and cell migration and invasion in HPV transformed cells. In the tumorigenesis and lung metastasis model in syngeneic mice, depletion of LKB1 markedly increased tumor metastatic colonies in lungs without affecting subcutaneous tumor growth. We showed that HPV16 E6/E7 enhanced the expression of hexokinase-ll (HK-II) in the glycolytic pathway through elevated c-MYC. Ectopic LKB1 reduced HK-II along with glycolysis. The inverse relationship between HK-II and LKB1 was also observed in normal and HPV-associated cervical lesions. We propose that LKB1 acts as a safeguard against HPV-stimulated aerobic glycolysis and tumor progression. These findings may eventually aid in the development of therapeutic strategy for HPV-associated malignancies by targeting cell metabolism.
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Affiliation(s)
- Q Zeng
- Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China.,Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - J Chen
- Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Y Li
- Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - K D Werle
- Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - R-X Zhao
- Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - C-S Quan
- Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China
| | - Y-S Wang
- Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China
| | - Y-X Zhai
- Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China
| | - J-W Wang
- Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China
| | - M Youssef
- Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - R Cui
- Department of Dermatology, Boston University, School of Medicine, Boston, MA, USA
| | - J Liang
- Department of Systems Biology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - N Genovese
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - L T Chow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Y-L Li
- Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China
| | - Z-X Xu
- Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China.,Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
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Van Tine BA, Knops J, Broker TR, Chow LT, Moen PT. In situ analysis of the transcriptional activity of integrated viral DNA using tyramide-FISH. Dev Biol (Basel) 2002; 106:381-5. [PMID: 11761253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Infection by the oncogenic human papillomavirus (HPV) types 16 and type 18 can progress to cancers. Two well studied cervical carcinoma cell lines, SiHa and CaSki, contain two to four copies, or several hundred copies of integrated HPV-16, respectively. To define the chromosomal loci from which HPV mRNAs are transcribed in these cells, we have simultaneously visualized chromosomal DNA territories, HPV DNA or nascent HPV RNA sequences by using a highly sensitive in situ hybridization (T-FISH) technique employing deposition of fluorescent tyramides. We found that, in SiHa cells, nascent HPV RNAs co-localized with both integrated HPV copies on chromosome 13. Surprisingly, in CaSki cells, nascent HPV RNA only co-localized with one minor HPV DNA-positive locus on chromosome 14. The DNA signal intensity of this locus was consistent with a single to a few HPV intergrants. The tyramide methodologies described here provide an in-depth molecular cytological analyses applicable to research and diagnosis.
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Affiliation(s)
- B A Van Tine
- Department of Molecular and Cellular Pathology, University of Alabama at Birmingham, 35294, USA
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Broker TR, Chow LT. Human papillomaviruses: A window into the mechanism and regulation of eucaryotic cellular DNA replication. Dev Biol (Basel) 2002; 106:367-73. [PMID: 11761250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Papillomaviruses are ubiquitous pathogens of humans and other vertebrates. Productive infections lead to hyperproliferative lesions in squamous epithelia from diverse anatomic sites, both cutaneous and mucosal. The 7,900 bp double-stranded, circular DNA genome replicates as extrachromosomal plasmids in the nuclei of infected cells. The productive phase of the HPV infection takes place in differentiated, post-mitotic squamous keratinocytes. However, viral DNA replication requires the host cells to supply much of the replication machinery and substrates. Consequently, these viruses usurp the cellular control mechanisms via protein interactions and provide an excellent model system to investigate cellular processes. This paper summarize our investigations and insight into the virus-host interactions observed in productively infected patient lesions, in a model organotypic culture system of primary human keratinocytes transduced with viral genes, and in a cell-free viral DNA replication system with purified viral and host protein.
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Affiliation(s)
- T R Broker
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294-0005, USA
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Broker TR, Jin G, Croom-Rivers A, Bragg SM, Richardson M, Chow LT, Vermund SH, Alvarez RD, Pappas PG, Squires KE, Hoesley CJ. Viral latency--the papillomavirus model. Dev Biol (Basel) 2002; 106:443-51; discussion 452-3, 465-75. [PMID: 11761260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
To investigate the prevalence and the natural history of human papillomavirus infections, we monitored HPV DNA shedding as a consequence of immunosuppression, with the expectation that latent viral infections would reactivate and become detectable. The study populations consisted of women who were in end-stage renal failure, those who ultimately received kidney transplantations, and those who had HIV/AIDS with various degrees of immune depression at entry. For each woman, cervico-vaginal lavage to sample viral shedding from the lower genital tract was performed at approximately six month intervals, and the cohorts have been followed since 1996. Nested polymerase chain reaction amplification of papillomavirus DNA using novel pairs of primers was followed by diagnostic restriction endonuclease cleavage or by DNA sequencing. This strategy is particularly capable of identifying single and multiple infections and determining the genotypes of any viruses present. Of the 225 women in the HIV cohort, 177 (79%) were HPV-positive and 111 (49%) shed from two up to eight different HPV types over the course of the survey. Thirty-five different mucosotropic HPV types, virtually all that have ever been described worldwide, were isolated from these 225 women, and nine additional new (provisional) types were discovered. As is always the case, HPV-6 was very common. However, all the other frequently detected HPV types (45, 52, 53, 54, 58, 74) were more prevalent than the types typically reported forthe general population (HPV-11, 16, 18, 31, 33, 35). Notably, the 14 members of the A3 phylogenetic subgroup (HPV-61, 62, 72, 81, 83, 84, and all the new types) were by far the most frequently observed viral types in the AIDS cohort. The HPV prevalence in the cohorts of kidney transplantation candidates and recipients was only slightly lower than that in the AIDS cohort. We conclude that HPV infections are extraordinarily common and are normally held in a sub-clinical state by functional immune systems, but can be reactivated by immunosuppressive conditions. The question of how so many distinct types persist in the human population and can be repeatedly isolated from specimens collected around the world raises complex issues concerning the nature of viral transmission, reproduction, shedding, and mutational drift. These molecular epidemiological observations signal the likelihood that HPV is part of the commensal microflora of human epithelia. Their prevalence elicits a caution that latent HPV DNA may be present in primary human epithelial tissues.
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Affiliation(s)
- T R Broker
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294-0005, USA
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Boxman IL, Mulder LH, Noya F, de Waard V, Gibbs S, Broker TR, ten Kate F, Chow LT, ter Schegget J. Transduction of the E6 and E7 genes of epidermodysplasia-verruciformis-associated human papillomaviruses alters human keratinocyte growth and differentiation in organotypic cultures. J Invest Dermatol 2001; 117:1397-404. [PMID: 11886500 DOI: 10.1046/j.0022-202x.2001.01602.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Epidermodysplasia-verruciformis-associated human papilloma virus DNA has been detected in skin cancers, in premalignant and benign skin lesions, and in plucked hairs from immunocompetent and immunosuppressed patients. The role of epidermodysplasia-verruciformis-associated human papilloma virus in the pathogenesis of nonmelanoma skin cancer is still enigmatic. In organotypic cultures we investigated the effects of retroviral transduction of the E6 and E7 genes of epidermodysplasia-verruciformis-associated human papilloma virus types 5, 12, 15, 17, 20, and 38 on the growth and differentiation of human keratinocytes. Differentiation was disturbed to different degrees as revealed by histology and by the expression patterns of differentiation markers keratin 10 and small proline rich protein 2. Conversely, proliferating cell nuclear antigen was induced in some of the suprabasal, differentiated cells to varying extent. No unscheduled DNA synthesis was detected in these cells, however, as probed by 5'-bromo-2'-deoxyuridine incorporation. Most intriguingly, when the E6 and E7 genes of epidermodysplasia-verruciformis-associated human papilloma virus types 15 and 17 were transduced, a broadening layer of basal cells and an accelerated differentiation were observed. In addition, "papilla-like structures" comprising basal-like keratinocytes arose from the basal layer into the differentiated layers. These cells did not express the differentiation markers keratin 10 and small proline rich protein 2, but did actively replicate DNA. These observations warrant further research by using this system to elucidate the replication strategy of epidermodysplasia-verruciformis-associated human papilloma virus types in keratinocytes and to shed light on the role of these human papilloma virus types in the pathogenesis of skin cancer.
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Affiliation(s)
- I L Boxman
- Department of Virology, Academic Medical Center, Amsterdam, The Netherlands
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Kumta SM, Zhu QS, Lee KM, Griffith J, Chow LT, Leung PC. Clinical significance of P-glycoprotein immunohistochemistry and doxorubicin binding assay in patients with osteosarcoma. Int Orthop 2001; 25:279-82. [PMID: 11794258 PMCID: PMC3620808 DOI: 10.1007/s002640100273] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In 45 osteosarcoma patients, mean age 18 (4-61) years and followed for 14 (5-48) months, we studied the sensitivity to doxorubicin as well as P-glycoprotein expression, and compared these with the extent of tumour necrosis following chemotherapy. Doxorubicin assay was positive in 37 patients in whom necrosis induced by chemotherapy was good in 20 and poor in 17. Metastases developed in nine patients. In eight patients in whom doxorubicin assay indicated tumour resistance, chemonecrosis was poor and all developed pulmonary metastases. P-glycoprotein was studied in pre-treatment biopsies and post-treatment resection specimens. Its expression was positive in 16 patients in whom the necrosis induced by chemotherapy was good in four and poor in 12. In 29 patients with negative P-glycoprotein expression, necrosis was good in 16 and poor in 13. The doxorubicin sensitivity had a high correlation with chemonecrosis (P=0.006) and the incidence of metastases (P<0.001). However, P-glycoprotein expression at the time of diagnosis did not correlate statistically with chemonecrosis (P=0.066). Doxorubicin sensitivity prior to treatment is a better determinant of the response to chemotherapy and clinical outcome than is the P-glycoprotein expression.
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Affiliation(s)
- S M Kumta
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin NT, SAR.
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Chow LT, Chow SS, Anderson RH, Gosling JA. Autonomic innervation of the human cardiac conduction system: changes from infancy to senility--an immunohistochemical and histochemical analysis. Anat Rec 2001; 264:169-82. [PMID: 11590594 DOI: 10.1002/ar.1158] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In order to study the changes in the pattern of autonomic innervation of the human cardiac conduction system in relation to age, the innervation of the conduction system of 24 human hearts (the age of the individuals ranged from newborn to 80 years), freshly obtained at autopsy, was evaluated by a combination of immunofluorescence and histochemical techniques. The pattern of distribution and density of nerves exhibiting immunoreactivity against protein gene product 9.5 (PGP), a general neural marker, dopamine beta-hydroxylase (DBH) and tyrosine hydroxylase (TH), indicators for presumptive sympathetic neural tissue, and those demonstrating positive acetylcholinesterase (AChE) activity, were studied. All these nerves showed a similar pattern of distribution and developmental changes. The density of innervation, assessed semiquantitatively, was highest in the sinus node, and exhibited a decreasing gradient through the atrioventricular node, penetrating and branching bundle, to the bundle branches. Other than a paucity of those showing AChE activity, nerves were present in substantial quantities in infancy. They then increased in density to a maximum in childhood, at which time the adult pattern was achieved and then gradually decreased in density in the elders to a level similar to or slightly less than that in infancy. In contrast, only scattered AChE-positive nerves were found in the sinus and atrioventricular nodes, but were absent from the bundle branches of the infant heart, whereas these conduction tissues themselves possessing a substantial amount of pseudocholinesterase. During maturation into adulthood, however, the conduction tissues gradually lost their content of pseudocholinesterase but acquired a rich supply of AChE-positive nerves, comparable in density to those of DBH and TH nerves. The decline in density of AChE-positive nerves in the conduction tissues in the elders was also similar to those of DBH and TH nerves. Our findings of initial sympathetic dominance in the neural supply to the human cardiac conduction system in infancy, and its gradual transition into a sympathetic and parasympathetic codominance in adulthood, correlate well with the physiologic alterations known to occur in cardiac rate during postnatal development. The finding of reduction in density of innervation of the conduction tissue with ageing is also in agreement with clinical and electrophysiological findings such as age-associated reduction in cardiac response to parasympathetic stimulation. Finally, our findings also support the hypothesis that, in addition to the para-arterial route, the parafascicular route of extension along the conduction tissue constitutes another pathway for the innervation of the conduction system of the human heart during development.
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Affiliation(s)
- L T Chow
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Shatin, Hong Kong.
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Balagué C, Noya F, Alemany R, Chow LT, Curiel DT. Human papillomavirus E6E7-mediated adenovirus cell killing: selectivity of mutant adenovirus replication in organotypic cultures of human keratinocytes. J Virol 2001; 75:7602-11. [PMID: 11462032 PMCID: PMC114995 DOI: 10.1128/jvi.75.16.7602-7611.2001] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Replication-competent adenoviruses are being investigated as potential anticancer agents. Exclusive virus replication in cancer cells has been proposed as a safety trait to be considered in the design of oncolytic adenoviruses. From this perspective, we have investigated several adenovirus mutants for their potential to conditionally replicate and promote the killing of cells expressing human papillomavirus (HPV) E6 and E7 oncoproteins, which are present in a high percentage of anogenital cancers. For this purpose, we have employed an organotypic model of human stratified squamous epithelium derived from primary keratinocytes that have been engineered to express HPV-18 oncoproteins stably. We show that, whereas wild-type adenovirus promotes a widespread cytopathic effect in all infected cells, E1A- and E1A/E1B-deleted adenoviruses cause no deleterious effect regardless of the coexpression of HPV18 E6E7. An adenovirus deleted in the CR2 domain of E1A, necessary for binding to the pRB family of pocket proteins, shows no selectivity of replication as it efficiently kills all normal and E6E7-expressing keratinocytes. Finally, an adenovirus mutant deleted in the CR1 and CR2 domains of E1A exhibits preferential replication and cell killing in HPV E6E7-expressing cultures. We conclude that the organotypic keratinocyte culture represents a distinct model to evaluate adenovirus selectivity and that, based on this model, further modifications of the adenovirus genome are required to restrict adenovirus replication to tumor cells.
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Affiliation(s)
- C Balagué
- Division of Human Gene Therapy, Departments of Medicine, Pathology, and Surgery, Gene Therapy Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
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Noya F, Chien WM, Broker TR, Chow LT. p21cip1 Degradation in differentiated keratinocytes is abrogated by costabilization with cyclin E induced by human papillomavirus E7. J Virol 2001; 75:6121-34. [PMID: 11390614 PMCID: PMC114328 DOI: 10.1128/jvi.75.13.6121-6134.2001] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2001] [Accepted: 04/09/2001] [Indexed: 01/29/2023] Open
Abstract
The human papillomavirus (HPV) E7 protein promotes S-phase reentry in a fraction of postmitotic, differentiated keratinocytes. Here we report that these cells contain an inherent mechanism that opposes E7-induced DNA replication. In organotypic raft cultures of primary human keratinocytes, neither cyclin E nor p21cip1 is detectable in situ. However, E7-transduced differentiated cells not in S phase accumulate abundant cyclin E and p21cip1. We show that normally p21cip1 protein is rapidly degraded by proteasomes. In the presence of E7 or E6/E7, p21cip1, cyclin E, and cyclin E2 proteins were all up-regulated. The accumulation of p21cip1 protein is a posttranscriptional event, and ectopic cyclin E expression was sufficient to trigger it. In constract, cdk2 and p27kip1 were abundant in normal differentiated cells and were not significantly affected by E7. Cyclin E, cdk2, and p21cip1 or p27kip1 formed complexes, and relatively little kinase activity was found associated with cyclin E or cdk2. In patient papillomas and E7 raft cultures, all p27kip1-positive cells were negative for bromodeoxyuridine (BrdU) incorporation, but only some also contained cyclin E and p21cip1. In contrast, all cyclin E-positive cells also contained p27kip1. When the expression of p21cip1 was reduced by rottlerin, a PKC delta inhibitor, p27kip1- and BrdU-positive cells remained unchanged. These observations show that high levels of endogenous p27kip1 can prevent E7-induced S-phase reentry. This inhibition then leads to the stabilization of cyclin E and p21cip1. Since efficient initiation of viral DNA replication requires cyclin E and cdk2, its inhibition accounts for heterogeneous viral activities in productively infected lesions.
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Affiliation(s)
- F Noya
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0005, USA
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Southern SA, Noya F, Meyers C, Broker TR, Chow LT, Herrington CS. Tetrasomy is induced by human papillomavirus type 18 E7 gene expression in keratinocyte raft cultures. Cancer Res 2001; 61:4858-63. [PMID: 11406563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
We have demonstrated previously that oncogenic human papillomaviruses (HPVs) induce basal cell tetrasomy in low-grade squamous intraepithelial lesions of the cervix. To identify HPV genes and growth conditions involved in this process, we analyzed: (a) organotypic raft cultures of primary human keratinocytes transfected with whole HPV-18 genomes; and (b) organotypic raft cultures acutely infected with recombinant retroviruses expressing the HPV-18 E6, E7, or E6/E7 genes from the differentiation-dependent HPV-18 enhancer-promoter. Cultures were examined for HPV DNA by in situ hybridization and for karyotype by interphase cytogenetics. Tetrasomy occurred in the suprabasal strata of raft cultures expressing E7 and E6/E7 but not in those expressing E6 alone or in a control culture. These data indicate that suprabasal tetrasomy occurs in association with expression of the E7 gene alone. Basal cell tetrasomy was additionally observed in the raft culture transfected with whole HPV-18 genomes, consistent with observations in low-grade squamous intraepithelial lesions. The distribution of tetrasomic cells in these raft cultures may reflect the involvement of additional viral genes or possibly differences in the pattern of viral oncogene and host gene expression.
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Affiliation(s)
- S A Southern
- Department of Pathology, University of Liverpool, Royal Liverpool University Hospital, Liverpool L69 3GA, United Kingdom
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Chow LT, Griffith J, Chow WH, Kumta SM. Monostotic fibrous dysplasia of the spine: report of a case involving the lumbar transverse process and review of the literature. Arch Orthop Trauma Surg 2001; 120:460-4. [PMID: 10968541 DOI: 10.1007/pl00013774] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Monostotic fibrous dysplasia of the spine is rare. We report its clinical, radiologic and histologic features affecting a 47-year-old housewife. She presented with low-back pain of 1-year's duration, and radiographs showed a diffuse expansile lesion in the left transverse process of the fourth lumbar vertebra. The lesion was excised and histologically confirmed to be fibrous dysplasia. The patient remained well 8 years after operation. Including the present case, a total of 22 cases of monostotic fibrous dysplasia of the spine were found in the literature. Combining these reported cases, we found that the condition affects either sex with equal frequency and presents at any age, the mean being 32 years. There is no predilection for any part of the spinal column, though sacral or coccygeal involvement is distinctly rare. It most commonly involves the body and adjacent pedicle, although no part of the vertebra is spared. It is worth noting that a propensity for progressive enlargement, even to the extent of causing graft destruction, exists if the lesion is left untreated or incompletely treated. Complete removal of all involved bone, together with stabilization, should therefore be the treatment of choice for this condition.
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Affiliation(s)
- L T Chow
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Shatin, Hong Kong.
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Ma T, Van Tine BA, Wei Y, Garrett MD, Nelson D, Adams PD, Wang J, Qin J, Chow LT, Harper JW. Cell cycle-regulated phosphorylation of p220(NPAT) by cyclin E/Cdk2 in Cajal bodies promotes histone gene transcription. Genes Dev 2000; 14:2298-313. [PMID: 10995387 PMCID: PMC316935 DOI: 10.1101/gad.829500] [Citation(s) in RCA: 260] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2000] [Accepted: 08/01/2000] [Indexed: 11/24/2022]
Abstract
Cyclin E/Cdk2 acts at the G1/S-phase transition to promote the E2F transcriptional program and the initiation of DNA synthesis. To explore further how cyclin E/Cdk2 controls S-phase events, we examined the subcellular localization of the cyclin E/Cdk2 interacting protein p220(NPAT) and its regulation by phosphorylation. p220 is localized to discrete nuclear foci. Diploid fibroblasts in Go and G1 contain two p220 foci, whereas S- and G2-phase cells contain primarily four p220 foci. Cells in metaphase and telophase have no detectable focus. p220 foci contain cyclin E and are coincident with Cajal bodies (CBs), subnuclear organelles that associate with histone gene clusters on chromosomes 1 and 6. Interestingly, p220 foci associate with chromosome 6 throughout the cell cycle and with chromosome 1 during S phase. Five cyclin E/Cdk2 phosphorylation sites in p220 were identified. Phospho-specific antibodies against two of these sites react with p220 within CBs in a cell cycle-specific manner. The timing of p220 phosphorylation correlates with the appearance of cyclin E in CBs at the G1/S boundary, and this phosphorylation is maintained until prophase. Expression of p220 activates transcription of the histone H2B promoter. Importantly, mutation of Cdk2 phosphorylation sites to alanine abrogates the ability of p220 to activate the histone H2B promoter. Collectively, these results strongly suggest that p220(NPAT) links cyclical cyclin E/Cdk2 kinase activity to replication-dependent histone gene transcription.
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Affiliation(s)
- T Ma
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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Griffith JF, Chan AC, Ahuja AT, Leung SF, Chow LT, Chung SC, Metreweli C. Neck ultrasound in staging squamous oesophageal carcinoma - a high yield technique. Clin Radiol 2000; 55:696-701. [PMID: 10988048 DOI: 10.1053/crad.2000.0502] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AIM This study evaluates the use of neck ultrasound in staging squamous oesophageal carcinoma. MATERIALS AND METHODS A prospective analysis of the clinical, neck ultrasound (US) and thoraco-abdominal computed tomography (CT) findings in 121 patients with squamous oesophageal carcinoma at presentation was performed. The relationship between malignant neck nodes, mediastinal and abdominal adenopathy, location and size of the primary tumour was analysed. RESULTS Ten of 121 patients (8%) had clinically palpable neck nodes which were deemed malignant in six (5%) following US and fine-needle aspiration for cytology. Of those 111 patients with no palpable neck nodes, 31 (28%) had malignant nodes shown on US. The more cephalad the location of the primary tumour, the higher the frequency of malignant neck nodes which were found in 80%, 52%, 29% and 9% of cervical, upper thoracic, mid-thoracic and lower thoracic oesophageal tumours, respectively. Eleven (29%) of the 38 patients with malignant neck nodes shown on US had no CT evidence of additional adenopathy in the mediastinum or upper abdomen. Neck US altered TNM staging in 22/121 (18%) patients at presentation. CONCLUSION Neck US frequently detects clinically impalpable metastatic nodes leading to altered TNM staging in patients with squamous oesophageal carcinoma. We advocate its routine use when staging squamous oesophageal carcinoma.
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Affiliation(s)
- J F Griffith
- Departments of Diagnostic Radiology and Organ Imaging, Chinese University of Hong Kong, New Terrorities.
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Chien WM, Parker JN, Schmidt-Grimminger DC, Broker TR, Chow LT. Casein kinase II phosphorylation of the human papillomavirus-18 E7 protein is critical for promoting S-phase entry. Cell Growth Differ 2000; 11:425-35. [PMID: 10965847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The human papillomavirus type 18 E7 protein subverts the pRb/E2F pathway to promote S-phase reentry by postmitotic, differentiated primary human keratinocytes in support of viral DNA amplification. We prepared a panel of HPV-18 E7 mutations in pRb binding or in casein kinase II (CKII) phosphorylation. Our results showed that the ability of E7 binding to pRb correlated with the activation of DNA polymerase alpha or cyclin E to various extents in differentiated keratinocytes of organotypic cultures but was insufficient to induce the proliferating cell nuclear antigen. Proteins mutated in the CKII recognition sequence or in one or both serine substrates (S32 and S34) bound pRb in vitro, but only those with negative charges at these two residues induced proliferating cell nuclear antigen effectively. Nevertheless, unscheduled cellular DNA synthesis occurred very inefficiently relative to the wild-type E7, if at all. Thus, both pRb binding and CKII phosphorylation of E7 are critical for activating cellular genes essential for S-phase entry.
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Affiliation(s)
- W M Chien
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294-0005, USA
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16
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Abstract
OBJECTIVES We sought to compare the effects of two different beta-blockers, carvedilol and metoprolol, to an angiotensin-converting enzyme (ACE) inhibitor (captopril) on myocardial collagen deposition during healing and ventricular remodeling after myocardial infarction (MI). BACKGROUND Beta-adrenergic blockade has been shown to be beneficial post-MI and in chronic heart failure. Carvedilol is a new-generation vasodilating beta-blocker with additional alpha1-adrenoceptor antagonism and an antiproliferative action, but it is not known if it is more beneficial than standard selective beta-blockers. METHODS Using a rat model of MI, induced by left coronary ligation, we studied the effects of 11 weeks of therapy with oral carvedilol, metoprolol or captopril on hemodynamics, tissue weights, collagen volume fraction and hydroxyproline content. RESULTS Both beta-blockers caused similar decreases in heart rate and LVEDP compared with untreated post-MI rats. At equivalent beta-adrenoceptor blocking doses, however, carvedilol, but not metoprolol, attenuated the increase in collagen content in noninfarcted regions and prevented the increase in right ventricular weight/body weight (all p < 0.05), and its effect was similar to captopril. Metoprolol treatment tended to increase right ventricular weight and heart weight (p < 0.05). There were no differences in infarct size between the groups. CONCLUSIONS Long-term treatment with both beta-blockers, as well as an ACE inhibitor, benefited the healing process in rats post-MI. At equivalent myocardial beta-adrenoceptor blocking doses, however, carvedilol significantly reduced myocardial collagen in the noninfarcted myocardium and cardiac hypertrophy in the right ventricle, whereas metoprolol had no effect on myocardial collagen deposition.
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Affiliation(s)
- S Wei
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, SAR
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17
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Zou N, Lin BY, Duan F, Lee KY, Jin G, Guan R, Yao G, Lefkowitz EJ, Broker TR, Chow LT. The hinge of the human papillomavirus type 11 E2 protein contains major determinants for nuclear localization and nuclear matrix association. J Virol 2000; 74:3761-70. [PMID: 10729151 PMCID: PMC111885 DOI: 10.1128/jvi.74.8.3761-3770.2000] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The E2 protein of papillomaviruses is a site-specific DNA binding nuclear protein. It functions as the primary replication origin recognition protein and assists in the assembly of the preinitiation complex. It also helps regulate transcription from the native viral promoter. The E2 protein consists of an amino-terminal (N) trans-acting domain, a central hinge (H) domain, and a carboxyl-terminal (C) protein dimerization and DNA binding domain. The hinge is highly divergent among papillomaviruses, and little is known about its functions. We fused the enhanced green fluorescent protein (GFP) with the full-length human papillomavirus type 11 (HPV-11) E2 protein and showed that the resultant fusion, called gfpE2, maintained transcription and replication functions of the wild-type protein and formed similar subnuclear foci. Using a series of GFP fusion proteins, we showed that the hinge conferred strong nuclear localization, whereas the N or C domain was present in both cytoplasm and nucleus. Biochemical fractionation demonstrated that the N domain and hinge, but not the C domain, independently associated with the nuclear matrix. Mutational analyses showed that a cluster of basic amino acid residues, which is conserved among many mucosotropic papillomaviruses, was required for efficient nuclear localization and nuclear matrix association. This mutation no longer repressed the HPV-11 upstream regulatory region-controlled reporter expression. However, a very small fraction of this mutant colocalized with E1 in the nucleus, perhaps by a piggyback mechanism, and was able to support transient replication. We propose that the hinge is critical for the diverse regulatory functions of the HPV-11 E2 protein during mRNA transcription and viral DNA replication.
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Affiliation(s)
- N Zou
- Department of Biochemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005, USA
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18
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Kumta SM, Leung PC, Griffith JF, Kew J, Chow LT. Vascularised bone grafting for fibrous dysplasia of the upper limb. J Bone Joint Surg Br 2000; 82:409-12. [PMID: 10813179 DOI: 10.1302/0301-620x.82b3.10221] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We describe our experience with vascularised bone grafting for the treatment of fibrous dysplasia of the upper limb in eight patients, five men and three women, aged between 17 and 36 years. The site was in the humerus in six and the radius in two. Persistent pain, progression of the lesion and pathological fracture with delayed union were the indications for surgical intervention. We used a vascularised fibular graft after curettage of the lesion. Function and radiological progress were serially monitored. Early radiological union of the graft occurred at periods ranging from 8 to 14 weeks. The mean period for reconstitution of the diameter of the bone was 14 months (12 to 18) predominantly through inductive formation of bone around the vascularised graft, which was a prominent feature in all patients. There were no recurrences and none of the grafts sustained a fracture or failed to unite. After operation function was excellent in three patients and good in five. Vascularised bone grafts provide a safe and reliable means of ensuring good continuity of bone with little risk of recurrence and failure.
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Affiliation(s)
- S M Kumta
- Chinese University of Hong Kong, Hong Kong
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19
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Lin BY, Ma T, Liu JS, Kuo SR, Jin G, Broker TR, Harper JW, Chow LT. HeLa cells are phenotypically limiting in cyclin E/CDK2 for efficient human papillomavirus DNA replication. J Biol Chem 2000; 275:6167-74. [PMID: 10692408 DOI: 10.1074/jbc.275.9.6167] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human papillomaviral (HPV) origin-containing plasmids replicate efficiently in human 293 cells or cell extracts in the presence of HPV origin-recognition protein E2 and replication initiation protein E1, whereas cervical carcinoma-derived, HPV-18-positive HeLa cells or cell extracts support HPV DNA replication poorly. We recently showed that HPV-11 E1 interacts with cyclin/cyclin-dependent kinase (cdk) complexes through an RXL motif and is a substrate for these kinases. E1 mutations in this motif or in candidate cdk phosphorylation sites are impaired in replication, suggesting a role for cdks in HPV replication. We now demonstrate that one limiting activity in HeLa cells is cyclin E/CDK2. Purified cyclin E/CDK2 or cyclin E/CDK3 complex, but not other cdks, partially complemented HeLa cell extracts. Cyclin E/CDK2 expression vectors also enhanced transient HPV replication in HeLa cells. HeLa cell-derived HPV-18 E1 protein is truncated at the carboxyl terminus but can associate with cyclin E/CDK2. This truncated E1 was replication-incompetent and inhibited cell-free HPV replication. These results indicate that HeLa cells are phenotypically limiting in cyclin E/CDK2 for efficient HPV replication, most likely due to sequestration by the endogenous, defective HPV-18 E1 protein. Further analyses of the regulation of HPV E1 and HPV replication by cyclin E may shed light on the roles of cyclin E/CDK2 in cellular DNA replication.
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Affiliation(s)
- B Y Lin
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0005, USA
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20
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Abstract
The promyelocytic leukemia (PML) gene, which encodes a transformation and growth suppressor, was first identified at the chromosomal translocation break point t(15;17) in acute promyelocytic leukemia (PML). To determine if the PML gene might be involved in other neoplasias such as lung cancer, PML expression was analyzed by immunohistochemical staining and in situ hybridization. Considerable PML protein expression in the PML-oncogenic domain (POD) structure was found in adenocarcinomas (ADC) and squamous cell carcinomas (SCC) of the lung, but was almost completely absent in all the small cell lung carcinomas (SCLC) examined. In situ hybridization showed that both mRNA and DNA of PML were present in SCLC and in normal lung, suggesting that the decreased protein expression was due to either a defect in translation or protein instability, rather than the consequence of decreased transcription or gene deletion. Double staining showed that PML expression was inversely correlated with the proliferation marker Ki-67 and positively correlated with levels of apoptotic cells in these tumors. To determine if the precursor cells of SCLC, the neuroendocrine-producing cells, express PML, double labeling was performed with PML and chromogranin A, a bio-marker for neuroendocrine cells. Neuroendocrine cells from normal tissues were found to be PML positive, indicating that the lack of PML protein in SCLC is associated with the tumorigenic phenotype and is not the result of cell-lineage specificity. Thus, the decreased PML expression may play an important role in SCLC development.
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Affiliation(s)
- P Zhang
- Department of Surgery, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China
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21
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Griffith JF, Chan AC, Chow LT, Leung SF, Lam YH, Liang EY, Chung SC, Metreweli C. Assessing chemotherapy response of squamous cell oesophageal carcinoma with spiral CT. Br J Radiol 1999; 72:678-84. [PMID: 10624325 DOI: 10.1259/bjr.72.859.10624325] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
45 patients with squamous cell carcinoma of the oesophagus were examined prior to, and following, pre-operative chemotherapy by spiral CT. Oesophageal CT was performed following gaseous distention of the oesophagus. TNM stage and perceived resectability on CT before and after chemotherapy were compared and related to surgical resectability and pathological staging. T-stage changed in 26% and N-stage changed in 9% of tumours after chemotherapy. Post-chemotherapy CT predicted pathological T-stage with an accuracy of 88% and N-stage with an accuracy of 84%. Six of 14 tumours considered irresectable on CT pre-chemotherapy were considered resectable on post-chemotherapy CT. Five of these six tumours were resectable at surgery. Post-chemotherapy CT predicted surgical resectability with an accuracy of 88%, the main pitfall being underestimation and overestimation of tracheobronchial invasion. CT prediction of chemotherapy response as judged by change in tumour volume was compared with a quantitative pathological assessment of chemotherapy response. 93% of oesophageal tumours changed volume after chemotherapy with 51% having a volume reduction of > or = 50%. However, no correlation was found between tumour volume reduction on serial CT examinations and either a quantitative pathological assessment of tumour response or patient survival.
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Affiliation(s)
- J F Griffith
- Department of Diagnostic Radiology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong
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22
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Xie W, Chow LT, Paterson AJ, Chin E, Kudlow JE. Conditional expression of the ErbB2 oncogene elicits reversible hyperplasia in stratified epithelia and up-regulation of TGFalpha expression in transgenic mice. Oncogene 1999; 18:3593-607. [PMID: 10380881 DOI: 10.1038/sj.onc.1202673] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ErbB2 receptor tyrosine kinase (RTK) is expressed in basal cells of squamous epithelia and the outer root sheath of hair follicles. We previously showed that constitutive expression of activated ErbB2 directed to these sites in the skin by the keratin 14 (K14) promoter produces prominent hair follicle abnormalities and striking skin hyperplasia in transgenic mice. However, perinatal lethality precluded the establishment of a transgenic line for analysis of ErbB2 function in adult animals. To investigate the significance of ErbB2 signaling in epithelial tissues during and post development, we developed a K14-rtTA/TetRE-ErbB2 'Tet-On' bitransgenic mouse system. These mice were normal until the ErbB2 transgene was induced by exposure to doxycycline (Dox). Prenatal induction resulted in perinatal death. Postnatally, ErbB2 transgene expression was observed at 4 h after the initiation of Dox, and reached a plateau at 24 h. Skin hyperplasia followed after 2 days and these changes reverted to normal upon Dox withdrawal. In adults, as in the neonates, prolonged ErbB2 induction caused prominent skin and hair follicle hyperplasias. Severe hyperplasias in the cornea, eye lids, tongue and esophagus were also observed. ErbB2 transgene induction was accompanied by increased expression of TGFalpha, a ligand of epidermal growth factor receptor (EGFR), and to a lesser extent, EGFR, further enhancing RTK signal transduction. We conclude that ErbB2 plays important roles in both development and maintenance of hair follicles and diverse squamous epithelia and that this ligand-inducible and tissue-specific 'Tet-On' transgenic mouse system provides a means to study transgenes with perinatal toxicity.
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Affiliation(s)
- W Xie
- Department of Medicine/Endocrinology, University of Alabama at Birmingham, 35294-0012, USA
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23
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Foster KW, Ren S, Louro ID, Lobo-Ruppert SM, McKie-Bell P, Grizzle W, Hayes MR, Broker TR, Chow LT, Ruppert JM. Oncogene expression cloning by retroviral transduction of adenovirus E1A-immortalized rat kidney RK3E cells: transformation of a host with epithelial features by c-MYC and the zinc finger protein GKLF. Cell Growth Differ 1999; 10:423-34. [PMID: 10392904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
The function of several known oncogenes is restricted to specific host cells in vitro, suggesting that new genes may be identified by using alternate hosts. RK3E cells exhibit characteristics of epithelia and are susceptible to transformation by the G protein RAS and the zinc finger protein GLI. Expression cloning identified the major transforming activities in squamous cell carcinoma cell lines as c-MYC and the zinc finger protein gut-enriched Kruppel-like factor (GKLF)/epithelial zinc finger. In oral squamous epithelium, GKLF expression was detected in the upper, differentiating cell layers. In dysplastic epithelium, expression was prominently increased and was detected diffusely throughout the entire epithelium, indicating that GKLF is misexpressed in the basal compartment early during tumor progression. The results demonstrate transformation of epithelioid cells to be a sensitive and specific assay for oncogenes activated during tumorigenesis in vivo, and identify GKLF as an oncogene that may function as a regulator of proliferation or differentiation in epithelia.
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Affiliation(s)
- K W Foster
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294-3300, USA
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24
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Abstract
BACKGROUND Types I and III collagen have different physical properties, and an increase of type I/III ratio can have a deleterious impact on myocardial compliance and left and right ventricular diastolic function. Post-myocardial infarction, these changes in collagen types may be relevant to the remodeling process and the development of heart failure. METHODS AND RESULTS In the rat coronary ligation heart failure model, we studied the time course of changes in types I and III and total collagen levels over 10 weeks postinfarction. Collagen types were separately quantified in the left (LV) and right ventricles (RV) by computerized morphometry and standard immunohistochemistry techniques, and also by hydroxyproline analysis, and these were correlated with hemodynamic changes. Compared with sham-operated rats, total collagen level increased 2.5- to 2.9-fold and 1.7- to 2.9-fold in the noninfarcted areas (NIAs) of the LV and RV, respectively, over the 10-week period and showed a good relation with changes in hydroxyproline content (r2 = 0.62; P < .0001). In the NIAs of both the LV and RV, type III collagen level showed a transient twofold increase at 2 weeks, which declined to normal at 4 weeks. Type I collagen level increased twofold at 4 weeks in the NIA of the LV and remained elevated at 10 weeks. In the RV, type I collagen level increased 2.7-fold to a peak at 4 weeks and declined gradually to 1.7 times baseline at 10 weeks. The patterns of change in type I collagen level in the RV correlated with the changes in LV end-diastolic pressure (r = 0.73; P < .0001) and RV weight to body weight ratio (r = 0.73; P < .0001). CONCLUSION There is a relative greater increase of type I collagen level in the NIA and RV postinfarction, and this may lead to left and right ventricular dysfunction. Separate mechanisms might be involved in the induction of the different types of collagen deposition, with type I collagen levels apparently closely correlating with hemodynamic stress.
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Affiliation(s)
- S Wei
- Department of Medicine, Chinese University of Hong Kong, Prince of Wales Hospital, China
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25
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Zhao W, Noya F, Chen WY, Townes TM, Chow LT, Broker TR. Trichostatin A up-regulates human papillomavirus type 11 upstream regulatory region-E6 promoter activity in undifferentiated primary human keratinocytes. J Virol 1999; 73:5026-33. [PMID: 10233965 PMCID: PMC112547 DOI: 10.1128/jvi.73.6.5026-5033.1999] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human papillomavirus (HPV) gene expression in squamous epithelia is differentiation dependent in benign patient lesions and in organotypic raft cultures of primary human keratinocytes (PHKs). Using the lacZ reporter in raft cultures, we previously showed that this transcriptional regulation of the HPV type 11 (HPV-11) enhancer-promoter located in the upstream regulatory region (URR) appears to have resulted from coordination between the transcription transactivators AP1, Oct1, and Sp1 in differentiated upper strata and the repressor C/EBP in proliferating basal cells. We report here that trichostatin A, a specific inhibitor of histone deacetylase, dramatically stimulated reporter gene activity from the wild-type HPV-11 URR or the C/EBP mutation in PHKs grown in undifferentiated submerged cultures. In epithelial raft cultures, up-regulation occurred predominantly in basal and parabasal strata; this effect was promoter specific, as expression of the lacZ reporter gene driven by the murine leukemia virus long terminal repeat (LTR), the keratin 14 promoter, or the involucrin promoter was not altered, nor was expression of endogenous keratin 10 and profilaggrin affected. However, the responses were not cell type or species specific, as identical results were observed for both HPV-11 URR-lacZ and LTR-lacZ in murine retrovirus producer cell lines of fibroblast origin.
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Affiliation(s)
- W Zhao
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005, USA
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26
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Gadi VK, Zou N, Liu JS, Cheng S, Broker TR, Sorscher EJ, Chow LT. Components of human papillomavirus that activate transcription and support plasmid replication in human airway cells. Am J Respir Cell Mol Biol 1999; 20:1001-6. [PMID: 10226070 DOI: 10.1165/ajrcmb.20.5.3479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Human papillomaviruses (HPVs) such as types 6 and 11 can establish lifelong infections in airway epithelial cells in patients, and long-term infection can lead to pulmonary involvement and death. The mechanisms underlying this persistence depend on both the transcriptional activity of the viral enhancers and promoters and the ability of this virus to maintain its double-stranded circular DNA genome in infected tissues. We investigated the transcription and replication properties of HPV sequence elements and protein products in a human airway cell line. We showed that incorporation of the upstream regulatory region and cotransfection with expression vectors of two virus-encoded proteins, E1 and E2, conferred approximately 5,000-fold stimulation of reporter gene expression. Transient plasmid replication in transfected human airway cells and lungs of FVB/N-C57BL/6 mice was demonstrated by a modified transient replication assay. These results have important implications for viral pathogenesis in airway cells and the potential of HPV-based replicons for gene transfer into airway epithelium.
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Affiliation(s)
- V K Gadi
- Departments of Physiology and Biophysics, Biochemistry and Molecular Genetics, and Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Chow LT, Griffith JF, Kumta SM, Leung PC. Chronic recurrent multifocal osteomyelitis: a great clinical and radiologic mimic in need of recognition by the pathologist. APMIS 1999; 107:369-79. [PMID: 10230689 DOI: 10.1111/j.1699-0463.1999.tb01567.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The spectrum of histopathologic changes in four cases of chronic recurrent multifocal osteomyelitis encountered in our orthopedic outpatient clinic in the past 3 years was studied in conjunction with clinical and radiologic findings. All presented with pain with or without swelling in the affected region. Radiographically, the appearance of the lesions varied from a mixed picture of bone lysis and sclerosis with expansion to sclerosis alone to bone collapse. Bone scintigraphy demonstrated asymptomatic and separate foci of activity in all cases. Prior to biopsy, the clinical and radiologic differential diagnoses included Ewing's sarcoma, metastatic neuroblastoma, hematolymphoid malignancy, Langerhans cell histiocytosis and chronic infection, notably tuberculosis. The spectrum of histopathologic changes ranged from acute (acute inflammatory infiltration, active bone resorption and necrosis, reactive bone formation) to subacute (predominantly lymphocytic and plasma cell infiltration) to chronic inflammation (fibroblastic organization and bony sclerosis). Histologic changes correlated poorly with clinical features, but relatively well with radiologic findings. Lesional excision was performed in one case, cortical saucerization in another, while the final two cases received supportive treatment. All remained well 18-21 months post-therapy. Chronic recurrent multifocal osteomyelitis is a great clinical and radiologic mimic, which merits recognition by the pathologist. Awareness of the spectrum of histologic features encountered enables a correct diagnosis to be made in the appropriate clinical setting. The patient can thus be reassured of a favorable prognosis.
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Affiliation(s)
- L T Chow
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Shatin, Hong Kong
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28
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Swindle CS, Zou N, Van Tine BA, Shaw GM, Engler JA, Chow LT. Human papillomavirus DNA replication compartments in a transient DNA replication system. J Virol 1999; 73:1001-9. [PMID: 9882301 PMCID: PMC103920 DOI: 10.1128/jvi.73.2.1001-1009.1999] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/1998] [Accepted: 10/28/1998] [Indexed: 01/12/2023] Open
Abstract
Many DNA viruses replicate their genomes at nuclear foci in infected cells. Using indirect immunofluorescence in combination with fluorescence in situ hybridization, we colocalized the human papillomavirus (HPV) replicating proteins E1 and E2 and the replicating origin-containing plasmid to nuclear foci in transiently transfected cells. The host replication protein A (RP-A) was also colocalized to these foci. These nuclear structures were identified as active sites of viral DNA synthesis by bromodeoxyuridine (BrdU) pulse-labeling. Unexpectedly, the great majority of RP-A and BrdU incorporation was found in these HPV replication domains. Furthermore, E1, E2, and RP-A were also colocalized to nuclear foci in the absence of an origin-containing plasmid. These observations suggest a spatial reorganization of the host DNA replication machinery upon HPV DNA replication or E1 and E2 expression. Alternatively, viral DNA replication might be targeted to host nuclear domains that are active during the late S phase, when such domains are limited in number. In a fraction of cells expressing E1 and E2, the promyelocytic leukemia protein, a component of nuclear domain 10 (ND10), was either partially or completely colocalized with E1 and E2. Since ND10 structures were recently hypothesized to be sites of bovine papillomavirus virion assembly, our observation suggests that HPV DNA amplification might be partially coupled to virion assembly.
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Affiliation(s)
- C S Swindle
- Departments of Biochemistry and Molecular Genetics, Schools of Medicine and Dentistry, University of Alabama at Birmingham, Birmingham, Alabama, USA
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29
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Jian Y, Van Tine BA, Chien WM, Shaw GM, Broker TR, Chow LT. Concordant induction of cyclin E and p21cip1 in differentiated keratinocytes by the human papillomavirus E7 protein inhibits cellular and viral DNA synthesis. Cell Growth Differ 1999; 10:101-11. [PMID: 10074904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Productive infections by human papillomaviruses (HPVs) occur only in differentiated keratinocytes in squamous epithelia in which the HPV E7 protein reactivates the host DNA replication machinery to support viral DNA replication. In a fraction of the differentiated keratinocytes, E7 also posttranscriptionally induces p21Cip1, which is distributed in a mutually exclusive manner with unscheduled cellular DNA synthesis. In this study, double immunofluorescence labeling unexpectedly revealed that E7 caused a concordant accumulation of both cyclin E and p21Cip1 to high levels in patient papillomas and in organotypic cultures of primary human keratinocytes. The induction of cyclin E is mutually exclusive with unscheduled cellular DNA synthesis or abundant viral DNA. These novel virus-host interactions in differentiated keratinocytes are in contrast to previous observations made in submerged proliferating cultures, in which HPV E7 induces cyclin E and overcomes p21Cip1 inhibition of S-phase entry. We propose that an appropriately timed induction of cyclin E/cyclin-dependent kinase 2 by HPV E7 in postmitotic cells enables S-phase reentry and HPV DNA amplification, whereas prematurely induced cyclin E stabilizes p21Cip1 protein, which then inhibits cyclin E/cyclin-dependent kinase 2. Consequently, cyclin E and p21Cip1 both fail to turn over, and DNA synthesis does not occur.
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Affiliation(s)
- Y Jian
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294-0005, USA
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Abstract
PURPOSE The purpose of this study was to determine the correlations between the sonographic measurement of splenic length and the actual splenic length, volume, and weight. METHODS Before autopsy, sonographic measurements of splenic length were obtained in 30 cadavers, and these values were compared with the actual length, volume, and weight of the spleen at autopsy. RESULTS There were clear linear correlations between maximum sonographic length and actual length (r = 0.831), volume (r = 0.817), and weight (r = 0.810). CONCLUSION This study shows that a single, simple sonographic measurement gives a clinically useful indication of true splenic size.
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Affiliation(s)
- W K Loftus
- Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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31
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Conger KL, Liu JS, Kuo SR, Chow LT, Wang TS. Human papillomavirus DNA replication. Interactions between the viral E1 protein and two subunits of human dna polymerase alpha/primase. J Biol Chem 1999; 274:2696-705. [PMID: 9915800 DOI: 10.1074/jbc.274.5.2696] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Papovaviruses are valuable models for the study of DNA replication in higher eukaryotic organisms, as they depend on host factors for replication of their DNA. In this study we investigate the interactions between the human papillomavirus type 11 (HPV-11) origin recognition and initiator protein E1 and human polymerase alpha/primase (pol alpha/primase) subunits. By using a variety of physical assays, we show that both 180- (p180) and 70-kDa (p70) subunits of pol alpha/primase interact with HPV-11 E1. The interactions of E1 with p180 and p70 are functionally different in cell-free replication of an HPV-11 origin-containing plasmid. Exogenously added p180 inhibits both E2-dependent and E2-independent cell-free replication of HPV-11, whereas p70 inhibits E2-dependent but stimulates E2-independent replication. Our experiments indicate that p70 does not physically interact with E2 and suggest that it may compete with E2 for binding to E1. A model of how E2 and p70 sequentially interact with E1 during initiation of viral DNA replication is proposed.
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Affiliation(s)
- K L Conger
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305-5324, USA
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Zhao W, Chow LT, Broker TR. A distal element in the HPV-11 upstream regulatory region contributes to promoter repression in basal keratinocytes in squamous epithelium. Virology 1999; 253:219-29. [PMID: 9918880 DOI: 10.1006/viro.1998.9478] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In benign squamous lesions and in organotypic epithelial cultures, the human papillomavirus (HPV) E6 and E7 genes are transcriptionally up-regulated in differentiated, spinous keratinocytes. We previously identified sequence elements in the enhancer-promoter regions of HPV types 18 and 11 important for this promoter regulation by using the bacterial LacZ reporter gene in stratified raft cultures of primary human keratinocytes (PHKs) or in submerged, proliferating cultures acutely transduced with recombinant retroviruses. Notably, mutations in the promoter-proximal Sp1, Oct1, and AP1 sites each significantly reduce reporter activity in differentiated cells, indicating that the bound factors are transcription transactivators. In the present study, we performed further mutagenesis on distal motifs in the HPV-11 regulatory region in PHKs in submerged and raft cultures. Mutations in an AP2-like site, three individual NF-1 sites, or five NF-1 sites collectively reduced promoter activity slightly in differentiated cells. A mutation in a putative glucocorticoid response element had no discernable effect in the presence or the absence of dexamethasone. However, mutations in a C/EBP binding site, especially the distal site, strikingly up-regulated reporter gene expression, particularly in basal and lower spinous cells, implicating bound protein as a transcription repressor. Collectively, these results demonstrate that the overall differentiation-dependent papillomaviral gene expression observed in vivo and in vitro involves promoter repression in the lower strata and activation in the upper, differentiated strata.
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Affiliation(s)
- W Zhao
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35294-0005, USA
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Ma T, Zou N, Lin BY, Chow LT, Harper JW. Interaction between cyclin-dependent kinases and human papillomavirus replication-initiation protein E1 is required for efficient viral replication. Proc Natl Acad Sci U S A 1999; 96:382-7. [PMID: 9892642 PMCID: PMC15145 DOI: 10.1073/pnas.96.2.382] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/1998] [Accepted: 11/23/1998] [Indexed: 11/18/2022] Open
Abstract
We have identified the human papillomavirus (HPV) DNA replication initiation protein E1 as a tight-binding substrate of cyclin E/cyclin-dependent kinase (Cdk) complexes by using expression cloning. E1, a DNA helicase, collaborates with the HPV E2 protein in ori-dependent replication. E1 formed complexes with cyclin E in insect and mammalian cells, independent of Cdks and E2. Additional cyclins, including A-, B-, and F-type (but not D-type), interacted with the E1/E2 complex, and A- and E-type cyclin kinases were capable of phosphorylating E1 and E2 in vitro. Association with cyclins and efficient phosphorylation of E1 required the presence of a cyclin interaction motif (the RXL motif). E1 lacking the RXL motif displayed defects in E2-dependent HPV ori replication in vivo. Consistent with a role for Cdk-mediated phosphorylation in E1 function, an E1 protein lacking all four candidate Cdk phosphorylation sites still associated with E2 and cyclin E but was impaired in HPV replication in vitro and in vivo. Our data reveal a link between cyclin/Cdk function and activation of HPV DNA replication through targeting of Cdk complexes to the E1 replication-initiation protein and suggest a functional role for E1 phosphorylation by Cdks. The use of cyclin-binding RXL motifs is now emerging as a major mechanism by which cyclins are targeted to key substrates.
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Affiliation(s)
- T Ma
- Department of Biochemistry, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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Abstract
BACKGROUND In the progress toward "off-pump" endoscopic coronary artery surgical procedures, new techniques for coronary artery anastomoses are being developed. One such approach is the use of nonpenetrating titanium clips. We evaluated the quality of anastomoses achieved using this technique in a porcine model of saphenous vein-carotid artery grafting using scanning electron microscopy. METHODS Bilateral saphenous vein-carotid artery interposition grafts were implanted in 10 "white race" pigs, using the nonpenetrating clips in one side of the neck and conventional hand suturing on the opposite side. One week after operation, the grafts were harvested. RESULTS All grafts were patent 7 days after operation, and 40 anastomoses underwent scanning electron microscopic study. In all samples, the luminal surfaces of both the carotid artery and vein graft were covered by a continuous layer of endothelial cells up to the anastomosis. Anastomotic sites in all clipped samples and most of the sutured anastomoses were completely endothelialized, and anastomotic clefts were indistinguishable. However, in 25% of sutured specimens, the suture material remained clearly visible inside the lumen of the vessel, and the subendothelial matrix remained exposed, with extensive fibrin, red blood cells, and platelet deposition on its surface. CONCLUSIONS Because the endothelial coverage consistently appeared to be complete and the subendothelial matrix was not exposed, it is likely that the risk of early anastomotic thrombosis is reduced by using the nonpenetrating titanium clips.
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Affiliation(s)
- M B Izzat
- Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin.
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Liu JS, Kuo SR, Makhov AM, Cyr DM, Griffith JD, Broker TR, Chow LT. Human Hsp70 and Hsp40 chaperone proteins facilitate human papillomavirus-11 E1 protein binding to the origin and stimulate cell-free DNA replication. J Biol Chem 1998; 273:30704-12. [PMID: 9804845 DOI: 10.1074/jbc.273.46.30704] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human papillomavirus replication initiator, the E1 helicase, binds weakly to the origin of DNA replication. Purified human chaperone proteins Hsp70 and Hsp40 (HDJ-1 and HDJ-2) independently and additively enhanced E1 binding to the origin. The interaction between E1 and Hsp70 was transient and required ATP hydrolysis, whereas Hsp40 bound to E1 directly and remained in the complex. A peptide of 20 residues spanning the HPD loop and helix II of the J domain of YDJ-1 also stimulated E1 binding to the origin, alone or in combination with Hsp70 or Hsp40. A mutated peptide (H34Q) had a reduced activity, while an adjacent or an overlapping peptide had no effect. Neither Hsp70 nor the J peptide altered the E1/DNA ratio in the complex. Electron microscopy showed that E1 mainly bound to DNA as a hexamer. In the presence of Hsp40, E1 primarily bound to DNA as a dihexamer. Preincubation of chaperones with viral E1 and template shortened the lag time and increased replication in a cell-free system. Since two helicases are essential for bidirectional replication of human papillomavirus DNA, these results demonstrate that, as in prokaryotes, chaperones play an important role in the assembly of preinitiation complexes on the origin.
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Affiliation(s)
- J S Liu
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005, USA
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Kumta SM, Leung PC, Griffith JF, Roebuck DJ, Chow LT, Li CK. A technique for enhancing union of allograft to host bone. J Bone Joint Surg Br 1998; 80:994-8. [PMID: 9853491 DOI: 10.1302/0301-620x.80b6.8982] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The aim of limb-salvage surgery in malignant bone tumours in children is to restore function and eradicate local disease with as little morbidity as possible. Allografts are associated with a high rate of complications, particularly malunion at the allograft-host junction. We describe a simple technique which enhances union of allograft to host bone taking advantage of the discrepancy in size between the adult allograft and the child's bone. This involves lifting a flap of periosteum before resection from the host bone, which is then telescoped into the allograft medullary canal, which may require internal burring or splitting, for a distance of 1.5 to 2 cm and covering the bone junction with the periosteal flap. This is more stable than conventional end-to-end opposition. For each centimetre of telescoping the surface area available for bony union is increased more than three times. The periosteal flap also augments union. Additional surface fixation with a plate and screws is not necessary. We have used this technique in nine children, in eight of whom there was complete union at a mean of 16 weeks. Delayed union, associated with generalised limb osteoporosis, occurred in one. Early mobilisation, with weight-bearing by three weeks, was possible. There was only one fracture of the allograft.
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Affiliation(s)
- S M Kumta
- Prince of Wales Hospital, Chinese University of Hong Kong, New Territories, Shatin
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Jian Y, Schmidt-Grimminger DC, Chien WM, Wu X, Broker TR, Chow LT. Post-transcriptional induction of p21cip1 protein by human papillomavirus E7 inhibits unscheduled DNA synthesis reactivated in differentiated keratinocytes. Oncogene 1998; 17:2027-38. [PMID: 9798674 DOI: 10.1038/sj.onc.1202142] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Productive infection by human papillomaviruses (HPVs) occurs only in differentiated squamous epithelial cells in papillomas, condylomata, and low grade intraepithelial neoplasias. Host DNA replication is reactivated in a fraction of terminally differentiated keratinocytes in benign human lesions and in organotypic raft cultures of primary human keratinocytes (PHKs) transduced with retroviruses expressing HPV-18 E7 oncogene from its native upstream regulatory region (URR). Thus the natural function of E7 protein, which inactivates pRB family proteins, is to induce host genes essential to support viral DNA replication in post-mitotic cells. Using this raft culture model system, we show that HPV-18 URR-E7 induces the universal cyclin-dependent kinase inhibitor p21cip1 protein in a fraction of differentiated PHKs. Induction is mediated by posttranscriptional mechanisms independent of p53. Double immunofluorescence studies demonstrate that, in raft cultures and in laryngeal papillomas, p21cip1 induction and reactivated host DNA synthesis take place in a mutually exclusive manner in PCNA-positive, differentiated keratinocytes. We suggest that p21cip1 induction effectively blocks unscheduled DNA synthesis reactivated by E7. These results begin to explain the inverse relationship between p21cip1 induction and HPV activities previously observed in a spectrum of benign lesions regardless of HPV types present.
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Affiliation(s)
- Y Jian
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294-0005, USA
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Abstract
We present the clinical, radiographic and pathological features of a juxtacortical chondrosarcoma which underwent dedifferentiation to an osteosarcoma in a 47-year-old woman. The tumour, abutting the femoral diaphysis, had initially presented 20 years earlier. Local excision was performed at presentation and again 10 years later, but the tumour recurred on each occasion. Serial radiographs showed cortical saucerisation evolving to cortical buttressing and mounding. After 20 years a dramatic radiographic change heralded tumour dedifferentiation.
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Affiliation(s)
- S M Kumta
- Department of Orthopaedic Surgery and Traumatology, Chinese University of Hong Kong, Shatin, NT
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39
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Abstract
Benign fibrous histiocytoma (BFH) is a common soft tissue tumour. However, its occurrence in the orbit was not well recognised in the past. It is only in recent years that this condition has become more frequently diagnosed. Now, it is believed to be the commonest mesenchymal tumour of the orbit in adults. Its occurrence in the uveal tract is, however, exceedingly rare. Only one case of presumed fibrous histiocytoma of the choroid has been reported in the literature. We report herein a case of BFH of the choroid in the left eye of a Chinese woman. The patient presented with a huge but asymptomatic raised choroidal mass. Results of choroidal biopsy showed no sign of malignancy but definitive diagnosis could not be made. Enucleation was finally performed. The diagnosis was made on detailed evaluation of the results of the immunohistochemical staining and the ultrastructural findings. The patient remained well at the latest follow-up, which was 33 months after enucleation. Although BFH of the choroid is vary rare, its benign nature and the availability of choroidal biopsy for tissue diagnosis make it important to include this as one of the differential diagnoses for amelanotic choroidal mass.
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Affiliation(s)
- D S Lam
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin N.T.
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40
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Abstract
Intraventricular together with atrial-axis and nodoventricular discontinuity, in which various parts of the conduction system are replaced by fibrous or fatty tissue, constitute the three major pathological categories of isolated congenitally complete heart block. Intraventricular discontinuity is distinctly rare, with only two previous cases reported in the literature, one of which was associated with a familial history of heart block. The cardiac conduction systems of two cases of isolated congenitally complete heart block were serially sectioned and analyzed histopathologically. The findings were correlated with the clinical features, in particular, the family histories and maternal serum anti-Ro antibodies. Both cases, a 9-day-old neonate and an 8-year-old schoolgirl, showed a combination of nodoventricular and intraventricular discontinuity, with absence of the atrioventricular penetrating bundle, the entire right, and the proximal portion of the left bundle branch. The branching bundle was absent in the first case and replaced by fatty tissue in the second. In contrast to the commoner atrial-axis discontinuity in which the atrioventricular node itself is usually replaced by fibrous or fatty tissue with variable involvement distally, the sinus node, and in particular, the atrioventricular node were normal in both of our cases. There was no family history in either case, whereas tests for the maternal serum anti-Ro antibody were positive in the first but negative in the second case. Intraventricular discontinuity as a cause of isolated congenitally complete heart block is very rare. In our cases, it co-existed with nodoventricular discontinuity. It can be sporadic, familial, or associated with positive maternal serum anti-Ro antibodies.
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Affiliation(s)
- L T Chow
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Shatin, Hong Kong
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41
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Lee KY, Broker TR, Chow LT. Transcription factor YY1 represses cell-free replication from human papillomavirus origins. J Virol 1998; 72:4911-7. [PMID: 9573258 PMCID: PMC110050 DOI: 10.1128/jvi.72.6.4911-4917.1998] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/1997] [Accepted: 03/05/1998] [Indexed: 02/07/2023] Open
Abstract
We have established cell-free replication for the human papillomavirus type 18 (HPV-18) origin of replication (ori)-containing DNA by using purified HPV-18 E1 and E2 gene products expressed as fusion proteins in Escherichia coli. The transcription factor YY1 has been shown to regulate RNA transcription by binding to a sequence overlapping the putative E1 protein binding site in the HPV-18 ori. We show that exogenously added YY1 fusion protein inhibited HPV-18 ori replication. Cotransfection of YY1 expression vectors also inhibited transient replication in 293 cells. However, inhibition did not appear to be mediated by binding to its cognate site in the ori as YY1 also inhibited the replication of the HPV-11 ori, which does not have a known or suspected YY1 binding site. Moreover, inhibition was not alleviated by the inclusion of YY1 binding oligonucleotides in the replication reaction mixtures. Rather, we demonstrated a direct interaction between purified fusion E2 protein and fusion YY1 protein by the pull-down assay and a partial restoration of replication activity by an elevated E2 protein concentration. These results suggest that YY1 can inhibit HPV ori replication by interfering with E2 protein functions.
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Affiliation(s)
- K Y Lee
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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42
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Chow LT, Allen PW, Kumta SM, Griffith J, Li CK, Leung PC. Angiomatoid malignant fibrous histiocytoma: report of an unusual case with highly aggressive clinical course. J Foot Ankle Surg 1998; 37:235-8. [PMID: 9638550 DOI: 10.1016/s1067-2516(98)80117-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The authors report a case of angiomatoid malignant fibrous histiocytoma (AMFH), affecting a 9-year-old girl, with a highly aggressive clinical course. The tumor, noticed by the patient as a painless nodule in the dorsum of her left foot for 12 months, recurred 8 months after initial excision, and despite wide local reexcision, metastasized 4 months later to the liver and lung, where it grew at an alarming rate, to the extent of occupying the entire left hemithorax in a period of 10 weeks and killed the patient 14 months after initial excision. Review of the literature showed that the culminated rates of recurrence, metastasis, and mortality for AMFH were 23.2%, 8.7%, and 4.3%, respectively, indicating that it is definitely a malignant neoplasm with a potentially fatal outcome.
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Affiliation(s)
- L T Chow
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Hong Kong
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Xie W, Wu X, Chow LT, Chin E, Paterson AJ, Kudlow JE. Targeted expression of activated erbB-2 to the epidermis of transgenic mice elicits striking developmental abnormalities in the epidermis and hair follicles. Cell Growth Differ 1998; 9:313-25. [PMID: 9563851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The erbB-2 proto-oncogene belongs to a receptor tyrosine kinase family that includes the epidermal growth factor receptor, erbB-2, erbB-3, and erbB-4. erbB-2 is expressed in basal cells of the squamous epithelia and the outer root sheath of the hair follicles, but its function in epidermal development has not been well studied. To investigate its role in the skin, we created transgenic mice harboring an activated erbB-2 oncogene under the control of the human keratin 14 promoter. The keratin 14 promoter directed its expression to cells in which erbB-2 is normally expressed, whereas the activated receptor gene ensured increased signaling. All transgenic founder mice exhibited extensive and striking skin phenotype, including epidermal hyperplasia, preneoplasia, papilloma, hyperkeratosis, and dyskeratosis. The majority of the hair follicles were replaced by bizarre hyperproliferative intradermal squamous invaginations, whereas the rest of the follicles exhibited severe hyperplasia and disorganization. All but one of the transgenic mice died before or shortly after birth, probably as a consequence of defects in the skin and esophagus. These observations demonstrate that the skin is sensitive to erbB-2 signaling, suggesting an important role for this receptor tyrosine kinase in epidermal growth, differentiation, and hair follicle morphogenesis.
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Affiliation(s)
- W Xie
- Department of Medicine/Endocrinology, University of Alabama at Birmingham, 35294-0012, USA
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44
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Zou N, Liu JS, Kuo SR, Broker TR, Chow LT. The carboxyl-terminal region of the human papillomavirus type 16 E1 protein determines E2 protein specificity during DNA replication. J Virol 1998; 72:3436-41. [PMID: 9525677 PMCID: PMC109845 DOI: 10.1128/jvi.72.4.3436-3441.1998] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/1997] [Accepted: 12/17/1997] [Indexed: 02/06/2023] Open
Abstract
The mechanism of DNA replication is conserved among papillomaviruses. The virus-encoded E1 and E2 proteins collaborate to target the origin and recruit host DNA replication proteins. Expression vectors of E1 and E2 proteins support homologous and heterologous papillomaviral origin replication in transiently transfected cells. Viral proteins from different genotypes can also collaborate, albeit with different efficiencies, indicating a certain degree of specificity in E1-E2 interactions. We report that, in the assays of our study, the human papillomavirus type 11 (HPV-11) E1 protein functioned with the HPV-16 E2 protein, whereas the HPV-16 E1 protein exhibited no detectable activity with the HPV-11 E2 protein. Taking advantage of this distinction, we used chimeric E1 proteins to delineate the E1 protein domains responsible for this specificity. Hybrids containing HPV-16 E1 amino-terminal residues up to residue 365 efficiently replicated either viral origin in the presence of either E2 protein. The reciprocal hybrids containing amino-terminal HPV-11 sequences exhibited a high activity with HPV-16 E2 but no activity with HPV-11 E2. Reciprocal hybrid proteins with the carboxyl-terminal 44 residues from either E1 had an intermediate property, but both collaborated more efficiently with HPV-16 E2 than with HPV-11 E2. In contrast, chimeras with a junction in the putative ATPase domain showed little or no activity with either E2 protein. We conclude that the E1 protein consists of distinct structural and functional domains, with the carboxyl-terminal 284 residues of the HPV-16 E1 protein being the primary determinant for E2 specificity during replication, and that chimeric exchanges in or bordering the ATPase domain inactivate the protein.
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Affiliation(s)
- N Zou
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294-0005, USA
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45
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Schmidt-Grimminger DC, Wu X, Jian Y, Broker TR, Chow LT. Post-transcriptional induction of p21cip1 protein in condylomata and dysplasias is inversely related to human papillomavirus activities. Am J Pathol 1998; 152:1015-24. [PMID: 9546362 PMCID: PMC1858250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Infections of the genital and oral epithelia by human papillomaviruses cause condylomata, papillomas, and squamous intraepithelial neoplasms, some of which can progress to invasive cancers. We describe an induction of p21cip1/WAF1/sdi1 protein in a fraction of the spinous cells in benign lesions and in cervical intraepithelial neoplasia grades I and II. The induction appears to be post-transcriptional and independent of p53. p21cip1 antigen-positive cells were sporadic in cervical intraepithelial neoplasia III and rare and focal in carcinomas. In contrast, p21cip1 protein was below or at the threshold of detection in the differentiated cells of normal squamous epithelia from different body sites despite an up-regulation of p21cip1 RNA. In cervical intraepithelial neoplasias from patients who were also positive for the human immunodeficiency virus, there was an additional increase in p21cip1 RNA in the upper spinous cells without concomitant p21cip1 protein induction. A consistent inverse relationship was observed between the p21cip1 protein induction and abundant human papillomavirus DNA and RNAs. We propose that p21cip1 protein induction is a novel host response that inhibits viral DNA replication and thus prevents elevated viral transcription. This hypothesis can partly account for the heterogeneity and the differentiation-dependent viral activities commonly observed in benign human papillomavirus lesions.
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Affiliation(s)
- D C Schmidt-Grimminger
- The Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294-0005, USA
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46
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Abstract
Intracortical osteosarcomas originate in the bone cortex and represent the rarest type of osteosarcoma. We describe the clinical, radiological and histological features of an intracortical osteosarcoma occurring in the femur of a young man and discuss the pertinent features of this tumour compared to those previously reported.
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Affiliation(s)
- J F Griffith
- Department of Diagnostic Radiology and Organ Imaging, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong
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47
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Abstract
Pigmented villonodular synovitis, a benign but locally destructive fibrohistiocytic proliferative lesion involving tendon sheaths, bursae and diarthrodial joints, is distinctly rare in the temporomandibular joint. We report one such case occurring in a 42-year-old housewife who presented with a progressively enlarging right zygomatic mass for six months. On exploration, an orange-brown firm mass, 5 x 3 x 2 cm, was seen adherent to the lateral aspect of the capsule of the right temporomandibular joint, and eroding into the inferior aspect of the right temporal bone and part of the mandibular condyle. The mass was completely excised. Pathological examination showed features typical of those of pigmented villonodular synovitis and the lesion was entirely extra-articular in location. The patient remained well with no evidence of local recurrence two years after operation. Review of the literature and careful analysis of the clinicopathological features showed that the vast majority of the reported cases of pigmented villonodular synovitis of the temporomandibular joint belonged to the extra-articular variant, which is associated with a more aggressive local infiltrative behaviour and higher rate of local recurrence than the localized type. The recommended treatment for this condition is therefore wide local excision, aiming to remove the lesion as completely as possible without producing severe disability for the patient.
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Affiliation(s)
- L T Chow
- Department of Anatomical, Prince of Wales Hospital, Hong Kong
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48
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Steenbergen RD, Parker JN, Isern S, Snijders PJ, Walboomers JM, Meijer CJ, Broker TR, Chow LT. Viral E6-E7 transcription in the basal layer of organotypic cultures without apparent p21cip1 protein precedes immortalization of human papillomavirus type 16- and 18-transfected human keratinocytes. J Virol 1998; 72:749-57. [PMID: 9420282 PMCID: PMC109431 DOI: 10.1128/jvi.72.1.749-757.1998] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/1997] [Accepted: 10/03/1997] [Indexed: 02/05/2023] Open
Abstract
Organotypic cultures of human keratinocytes provide a useful model system to study human papillomavirus (HPV)-host cell interactions. In this study, we analyzed organotypic cultures of two HPV type 16 (HPV16) (FK16A and FK16B)- and two HPV18 (FK18A and FK18B)-transfected keratinocyte cell lines through the process of immortalization in vitro. For FK16A and FK18B cells, passages of both mortal cells in their extended life span and subsequent immortal stages were studied. Mortal cells of FK16A and FK18B showed a morphology reminiscent of mild to moderate dysplasia, whereas in their immortal descendants, severely dysplastic features were observed. Immortal FK18A cells were mildly to moderately dysplastic, while FK16B cells were severely dysplastic. The increasing degrees of dysplasia were associated with a decreasing expression of differentiation markers cytokeratin 10 and profilaggrin. All raft cultures expressed E6-E7 mRNAs in the basal layer, while the amount of viral transcripts in the suprabasal cells was in general proportional to the degree of dysplasia. In all cases, E6-E7 transcription and dysplastic features were highly correlated with cellular proliferation, as assessed by Ki-67 (MIB-1) antigen expression. Moreover, high levels of E6-E7 transcription and expression of p21cip1 protein in the basal layer seemed to be mutually exclusive. We conclude that expression of E6-E7 in the basal cells associated with increased proliferation in the absence of detectable p21cip1 protein is apparently necessary but not sufficient for immortalization, or for the loss of terminal differentiation, for which yet to be discovered additional events are required. The model system described in this study provides a valuable tool to analyze alterations in viral transcription regulation during HPV-mediated cell transformation.
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Affiliation(s)
- R D Steenbergen
- Department of Pathology, University Hospital Vrije Universiteit, Amsterdam, The Netherlands
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Chow LT, Chow WH. Hemopericardium secondary to infective aortitis complicating discrete membranous subaortic stenosis. West J Med 1998; 168:43-5. [PMID: 9448495 PMCID: PMC1304759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- L T Chow
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Hong Kong
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Chow LT, Chow WH, Lee JC, Chow SS, Anderson RH, Gosling JA. Postmortem changes in the immunohistochemical demonstration of nerves in human ventricular myocardium. J Anat 1998; 192 ( Pt 1):73-80. [PMID: 9568562 PMCID: PMC1467740 DOI: 10.1046/j.1469-7580.1998.19210073.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In order to delineate the effects of death on the immunofluorescence of autonomic nerves supplying the human ventricular myocardium, we studied percutaneous myocardial samples obtained postmortem from 5 individuals within 3 h of death. Subsequent samples were obtained daily from the same individuals up to a total of 5-11 d. The antibodies employed included those against protein gene product 9.5 to demonstrate nervous tissue, dopamine beta-hydroxylase and tyrosine hydroxylase to reveal catecholaminergic neural tissue and neuropeptide Y. An indirect immunofluorescence technique using the avidin-biotin method was employed. The density of myocardial protein gene product 9.5 immunoreactive nerves declined on the 7th day, and became markedly diminished by the 11th day. Immunoreactive dopamine beta-hydroxylase nerves decreased on the 5th day, and were difficult to identify by the 9th day. The density of tyrosine hydroxylase and neuropeptide Y containing nerves rapidly diminished on the 3rd and 4th days, and became undetectable by the 7th and 8th days, respectively. The present results indicate that, depending on the type of antibodies used, immunohistochemical techniques can be used on human hearts obtained up to within 6 d of death to study cardiac innervation.
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Affiliation(s)
- L T Chow
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Shatin, Hong Kong
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