Uncertain areas in the diagnosis of allergic bronchopulmonary aspergillosis in patients with asthma

BACKGROUND AND OBJECTIVE

The prevalence of allergic bronchopulmonary aspergillosis (ABPA) in patients with bronchial asthma remains unknown. We evaluated the roles of various laboratory tests in the diagnosis of ABPA, including, skin prick test (SPT) for Aspergillus fumigatus (Af), and serum Af specific IgE and IgG antibody measurement.

METHODS

A total of 50 asthma patients with more than 1000cell/μL of peripheral blood eosinophils were prospectively collected between January 2007 and September 2011. Evaluations using SPT for Af, serum total IgE and specific IgE antibody to Af by CAP system, IgG antibody to Af by enzyme immunoassay (EIA) or CAP system were performed according to the essential minimal criteria for the diagnosis of ABPA - asthma, immediate cutaneous reactivity to Af, elevated total IgE, and raised Af specific IgE and IgG.

RESULTS

Among 50 patients, three patients (6.0%) were diagnosed as ABPA, of whom each confirmed five items of the essential minimal diagnostic criteria for the diagnosis of ABPA. Six patients (12.0%) showed negative responses to Af in SPT, but positive responses in specific IgE by CAP system. Eight patients (16.0%) showed negative responses to IgG to Af by CAP system, but positive responses by enzyme immunoassay (EIA).

CONCLUSIONS

SPT and serum IgE to Af measurement by CAP system should be performed simultaneously. It is reasonable to set up cut-off values in Af specific IgE/IgG by CAP system for the differentiation of ABPA from Af sensitised asthma patients.

Clinical features of drug-induced hypersensitivity syndrome in 38 patients

BACKGROUND

The clinical features of drug-induced hypersensitivity syndrome (DIHS) or drug rash with eosinophilia and systemic symptoms (DRESS) syndrome are complicated, and the incidence of this condition is very low.

OBJECTIVE

To evaluate the clinical course of DIHS/DRESS and identify effective treatment options.

METHODS

This study was a retrospective analysis of prospectively collected clinical data in 38 consecutive patients with DIHS/DRESS diagnosed between March 2004 and January 2009. We investigated the clinical features, response to treatment, and outcome of 38 patients.

RESULTS

The study patients consisted of 18 men (47.4%) and 20 women (52.6%). The most common causative drugs were anticonvulsants (47.4%) and antibiotics (18.4%), followed by nonsteroidal anti-inflammatory drugs (NSAIDs) (13.2%), allopurinol (5.3%), and undetermined agents (15.8%). The latency period ranged from 3 to 105 days, with a mean (SD) of 25.2 (21.5) days. Systemic corticosteroids were administered to 16 patients (42.1%). Twenty-two (57.9%) patients were treated with topical corticosteroids and antihistamines (no systemic corticosteroids). Complete recovery was noted in 36 patients (94.8%). Two of the patients treated with systemic corticosteroids had a poor outcome: one died due to an opportunistic infection secondary to long-term systemic corticosteroid treatment; the other showed progressive deterioration of liver damage, although the final outcome is not known.

CONCLUSION

The drugs associated with DIHS/DRESS were variable and most frequently included anticonvulsants, beta-lactam antibiotics, and NSAIDs. The syndrome was more common than generally recognized. Additional studies are needed to evaluate the clinical indications for systemic corticosteroids in patients with DIHS/DRESS.

Comparative effect of seeds of Rhynchosia volubilis and soybean on MG-63 human osteoblastic cell proliferation and estrogenicity

The seeds of Rhynchosia volubilis (SRV) (Leguminosae) and soybean have been used in oriental folk medicine to prevent postmenopausal osteoporosis. Their beneficial effects are caused by a high content of isoflavone, which function as partial agonists or antagonists of estrogen. To compare the estrogenic effects of SRV and soybean on the MG-63 osteoblastic cell proliferation, 70% methanol extracts of SRV or soybean were treated on MG-63 cells. Although biphasic over a concentration range of 0.001 mg/ml-0.1 mg/ml, both SRV and soybean extracts increased MG-63 cell proliferation. However SRV was more effective at increasing the cell proliferation that paralleled with the greater estrogenic effects as determined by estrogen receptor alpha (ERalpha) expression, an estrogenic response element (ERE)-luciferase activity and the selective expression of insulin-like growth factor-I (IGF-I). SRV-induced IGF-I expression resulted from increases in the mRNA levels. Despite the increased expression of ERbeta, ERE activity and IGF-I expression by soybean were lower than those by SRV. Furthermore, the comparable estrogenic effects between SRV and the combined treatment of genistein and daidzein standards at 0.5 x 10(-8) M, which is a concentration of these two isoflavones similar to that of SRV at 0.001 mg/ml, demonstrate that the greater estrogenicity of SRV for MG-63 cell proliferation is mediated by the synergism of low levels of isoflavones for the selective expression of IGF-I.

Gene-gene and gene-environmental interactions of p53, p21, and IRF-1 polymorphisms in Korean women with cervix cancer

BACKGROUND

The aim of this study was to identify gene-gene and gene-environmental factors affecting cervix carcinogenesis in Korean women.

METHODS

We evaluated 530 subjects composed of 185 female cervix cancer patients and 345 normal healthy women. The single nucleotide polymorphisms (SNPs) of p53 codon 72, p21 codon 31, and interferon regulatory factor-1 (IRF-1) intron 6 were evaluated from extracted DNA of peripheral blood with an automatic DNA sequencer. The differences of each SNP, gene-gene and gene-environmental interactions between normal controls and patients were evaluated in the adjusted environmental background.

RESULTS

In the environmental aspect, the rate of cervix cancer increased in the women with a lower level of education, a younger age at first sexual intercourse and more childbearing. The women who had p53 (Arg/Arg), IRF-1 (T/T), and <6 years of education showed a 14.7-fold increased risk of cervix cancer compared to the women who had p53 ( approximately Pro), IRF-1 ( approximately C), and >15 years of education. The women who had p53 (Arg/Arg), p21 (Ser/Ser), and >3 children showed a 6.4-fold increased risk of cervix cancer compared to the women who had p53 ( approximately Pro), p21 ( approximately Arg), and no children. The women who had p53 (Arg/Arg), IRF-1 (T/T), and first sexual intercourse before 22 years old showed a 5.5-fold increased risk of cervix cancer compared to the women who had p53 ( approximately Pro), IRF-1 ( approximately C), and first sexual intercourse after 26 years old.

CONCLUSIONS

We found that the level of education, the age at first intercourse, and the number of children were independent risk factors in cervix carcinogenesis. The specific combinations of p53, p21, and IRF-1 gene-gene and gene-environmental interactions were significantly noted in the cervix carcinogenesis of Korean women.

Gene–gene and gene–environmental interactions of p53, p21, and IRF-1 polymorphisms in Korean women with cervix cancer

Background

The aim of this study was to identify gene–gene and gene–environmental factors affecting cervix carcinogenesis in Korean women.

Methods

We evaluated 530 subjects composed of 185 female cervix cancer patients and 345 normal healthy women. The single nucleotide polymorphisms (SNPs) of p53 codon 72, p21 codon 31, and interferon regulatory factor-1 (IRF-1) intron 6 were evaluated from extracted DNA of peripheral blood with an automatic DNA sequencer. The differences of each SNP, gene–gene and gene–environmental interactions between normal controls and patients were evaluated in the adjusted environmental background.

Results

In the environmental aspect, the rate of cervix cancer increased in the women with a lower level of education, a younger age at first sexual intercourse and more childbearing. The women who had p53 (Arg/Arg), IRF-1 (T/T), and <6 years of education showed a 14.7-fold increased risk of cervix cancer compared to the women who had p53 (∼Pro), IRF-1 (∼C), and >15 years of education. The women who had p53 (Arg/Arg), p21 (Ser/Ser), and >3 children showed a 6.4-fold increased risk of cervix cancer compared to the women who had p53 (∼Pro), p21 (∼Arg), and no children. The women who had p53 (Arg/Arg), IRF-1 (T/T), and first sexual intercourse before 22 years old showed a 5.5-fold increased risk of cervix cancer compared to the women who had p53 (∼Pro), IRF-1 (∼C), and first sexual intercourse after 26 years old.

Conclusions

We found that the level of education, the age at first intercourse, and the number of children were independent risk factors in cervix carcinogenesis. The specific combinations of p53, p21, and IRF-1 gene–gene and gene–environmental interactions were significantly noted in the cervix carcinogenesis of Korean women.

The effect of codon 98 of the FHIT gene on cervical cancer in Korean women

The Fragile Histadine Triad (FHIT) is a putative tumor suppressor gene involved in different tumors. The objective of this study was to examine the effect of codon 98 of FHIT on cervical carcinogenesis. The study subjects were patients who were pathologically diagnosed with cervical neoplasia and who had a positive result for human papillomavirus (n = 567) compared to normal healthy women as normal controls (n = 506). The FHIT-specific sequences of DNA from peripheral blood samples from study subjects were determined by PCR using allele-specific primers and were compared with those of the controls. The genetic susceptibility of codon 98 of the FHIT gene (3p14.2) in cervical carcinogenesis was determined by examining the effect of the gene and environmental factors vs. the different stages of cervical intraepithelial lesions and the different histopathologic types of invasive cervical cancers. On assessing FHIT polymorphisms, the percentages of individuals homozygous for the T allele, homozygous for the C allele, and heterozygous for these two alleles were 42.1%, 11.3, and 46.6% in the control group. The corresponding figures were 39.5%, 14.8%, and 45.7% among in women with cervical cancer. Compared with FHIT T/ T, odds ratio (95% confidence interval) for FHIT C/C was 1.4 (0.8-2.5) for invasive cervical cancer and 1.7 (0.9-3.1) for cervical intraepithelial neoplasia (CIN) II or III. The risks for invasive cervical cancer were higher with early onset cervical carcinogenesis (2.3, 1.0-5.5, P = 0.0438), than with late onset (1.0, 0.5-2.1, P = 0.9306). The risks of FHIT C/C or C/ T also increased for ever smokers or women with two or more children compared with FHIT T/ T. Polymorphisms of FHIT are associated with a higher risk of developing cervical cancer, in particular early onset cervical carcinogenesis.

The effect of codon 98 of the FHIT gene on cervical cancer in Korean women

The Fragile Histadine Triad (FHIT) is a putative tumor suppressor gene involved in different tumors. The objective of this study was to examine the effect of codon 98 of FHIT on cervical carcinogenesis. The study subjects were patients who were pathologically diagnosed with cervical neoplasia and who had a positive result for human papillomavirus (n = 567) compared to normal healthy women as normal controls (n = 506). The FHIT-specific sequences of DNA from peripheral blood samples from study subjects were determined by PCR using allele-specific primers and were compared with those of the controls. The genetic susceptibility of codon 98 of the FHIT gene (3p14.2) in cervical carcinogenesis was determined by examining the effect of the gene and environmental factors vs. the different stages of cervical intraepithelial lesions and the different histopathologic types of invasive cervical cancers. On assessing FHIT polymorphisms, the percentages of individuals homozygous for the T allele, homozygous for the C allele, and heterozygous for these two alleles were 42.1%, 11.3, and 46.6% in the control group. The corresponding figures were 39.5%, 14.8%, and 45.7% among in women with cervical cancer. Compared with FHIT T/ T, odds ratio (95% confidence interval) for FHIT C/C was 1.4 (0.8–2.5) for invasive cervical cancer and 1.7 (0.9–3.1) for cervical intraepithelial neoplasia (CIN) II or III. The risks for invasive cervical cancer were higher with early onset cervical carcinogenesis (2.3, 1.0–5.5, P = 0.0438), than with late onset (1.0, 0.5–2.1, P = 0.9306). The risks of FHIT C/C or C/ T also increased for ever smokers or women with two or more children compared with FHIT T/ T. Polymorphisms of FHIT are associated with a higher risk of developing cervical cancer, in particular early onset cervical carcinogenesis.

Antiproliferative mechanism of retinoid derivatives in ovarian cancer cells

Retinoid derivatives have been implicated for the growth regulation of ovarian cancer cells. However, the molecular mechanisms are not yet fully defined. To dissect detailed mechanisms of each derivative, four ovarian cancer cells (A2774, PA-1, OVCAR-3, SKOV-3) were treated with all-trans retinoic acid (ATRA), 9-cis retinoic acid (9-cis RA), 13-cis RA, or 4-hydroxyphenyl retinamide (4-HPR). When treated with 1 microm, HPR inhibits most effectively the growth of all four cells. Depending on cell types treated, IC(50) values were 0.7-2.7 microm for 4-HPR, and 2.7-9.0 microm for other retinoid derivatives. DNA fragmentation assay indicated that the antiproliferative effect of HPR could be mediated by apoptosis. Transcription assays coupled with transient transfection in OVCAR-3 cells indicated that ATRA, 9-cis RA, and 13-cis RA were active for all RAR/RXR subtypes, whereas 4-HPR was only active for RARgamma. However, 4-HPR exerted the strongest suppression on AP-1 (c-Jun) activity. As expected from AP-1 data, in vitro invasion assays showed that HPR blocked effectively the migration of OVCAR-3 cells. Thus, 4-HPR showed not only more potent antiproliferative activity than any other retinoid derivatives used, but also effectively inhibited the invasion, probably through the suppression of AP-1 activity. Taken together coupled with its selective activity only for RARgamma, these results suggest that 4-HPR could be less toxic, and very effective anticancer drugs for late stage ovarian cancer.

Functional inactivation of p73, a homolog of p53 tumor suppressor protein, by human papillomavirus E6 proteins

Human papillomavirus (HPV) is strongly implicated as a causative agent in the etiology of cervical cancer. Of its gene products, E6 binds to and inactivates p53 tumor suppressor protein by ubiquitin/proteasome-dependent degradation. Recently, p73, a novel family of p53, has been identified and demonstrated, like p53, to activate p21(WAF1). Here we show that p73 is also inactivated by HPV-E6, but ubiquitin-mediated proteolysis is not responsive. Yeast two-hybrid and GST pull-down assays indicate a physical interaction between p73 and either HPV-16 or HPV-11 E6 proteins in vivo and in vitro, respectively. The transactivation domain (amino acid residues 1 to 49) is found to be absolutely required for the interaction. Transient co-expression of E6 significantly inhibits the p73-mdiated activation of p21(WAF1) promoter in a p53-defective C33A cell line. Using Gal4-p73 fusion protein, we demonstrate that E6 inhibition of p73 transactivation function is independent of sequence-specific DNA binding, which is confirmed by a direct electrophoretic mobility shift assay. Moreover, E6 inhibits p73 function by interfering with the activity of the amino-terminal activation domain. Co-transfection of E6 mutants reveals that the same portion of E6 appears to be responsible for the inactivation of p53 and p73 function. However, the inactivation mechanism of p73 is clearly different from that of p53, because p73, unlike p53, is inactivated by both high- and low-risk E6s and is not susceptible to E6-dependent proteolysis. These overall results, consequently, suggest that in addition to the inactivation of p53, the functional interference of p73 by HPV-E6 may, at least in part, contribute to E6-mediated transformation and hyperproliferation of cervical cells.

Effect of BPV1 E2-mediated inhibition of E6/E7 expression in HPV16-positive cervical carcinoma cells

OBJECTIVE

E6 and E7 proteins of high-risk-type human papillomavirus are major etiological agents for cervical carcinomas and are continuously expressed in those cancer cells. They inhibit cell cycle control functions by inactivating p53 and Rb proteins and also immortalize cells through the induction of telomerase activity. Expression of E6 and E7 genes in HeLa, an HPV18-positive cell line, has been shown to be inhibited by the E2 protein of bovine papillomavirus (BPV1), and this resulted in the activation of the p53-mediated growth inhibitory pathway followed by an inhibition of cell proliferation. In this study, the effect of BPV1 E2-mediated inhibition of E6 and E7 expression was examined in HPV16-positive cervical carcinoma cell lines recently established from Korean patients.

METHODS

BPV1 E2 was expressed in the test cells through acute infection of an SV40-BPV1 recombinant virus. Its effect on cell proliferation was assessed through MTT and DNA synthesis assays, and the status of factors involved in cell cycle control was examined through Western blotting and reverse transcription-polymerase chain reaction.

RESULTS

BPV1 E2 expression caused a significant decrease in E6/E7 transcription in all three cell lines. This was accompanied by an increase in the levels of p53 protein and activity and a decrease in the expression of Cdc25A, a Cdk2-activating phosphatase. Concomitantly, E2F1 activity and cellular DNA synthesis capacity were significantly reduced.

CONCLUSIONS

These results indicate that inhibition of E6/E7 gene expression in the HPV16-positive cervical carcinoma cells induces suppression in cell proliferation by activating the growth inhibitory factors, p53 and Rb, and also by downregulating the cell cycle stimulatory factor, Cdc25A.

Expression of thrombospondin-1 in human hepatocarcinoma cell lines and its regulation by transcription factor Jun/AP-1

Thrombospondin-1 (TSP-1) is a homotrimeric glycoprotein synthesized in a variety of normal and transformed cells, and secreted into the extracellular matrix. Based on its known effects on the tumor and endothelial cells, TSP-1 was implicated in the tumor growth and metastasis. In the present study, we have demonstrated the expression of TSP-1 in the human hepatocarcinoma cell lines. TSP-1 was detected in human hepatocarcinoma SK-HEP-1, Hep 3B and immortalized human liver Chang cells. Using two different cell lines, SK-HEP-1 and Hep 3B cells, we have studied effects of phorbol 12-myristate 13-acetate (PMA) on TSP-1 expression. TSP-1 synthesis was stimulated by PMA in both cell lines. When the cells were treated with PMA, the TSP-1 mRNA started to increase at 30 min and reached the maximal level at 6 h. TSP-1 induction by PMA was completely inhibited by the pre-treatment of 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), a potent protein kinase C inhibitor. A TSP-1 promoter-luciferase reporter gene was transcriptionally activated by PMA, as well as by the expression of c-Jun. Among three putative AP-1 recognition sites on the TSP-1 promoter, a deletion of the 1st and 2nd sites caused loss of PMA-induced upregulation, while the 3rd site deletion showed no effect. In subsequent experiments, both the recombinant c-Jun and nuclear proteins induced by PMA have a stronger binding affinity for the 2nd AP-1 recognition site than the 1st and 3rd ones. Our study demonstrated that TSP-1 could be expressed and secreted by human hepatoma cell lines and its expression could be effectively regulated by PMA. We also suggest that AP-1 binding activity through the protein kinase C activation is a critical event for the TSP-1 gene expression and consequently affects production and processing of the protein.

Inactivation of interferon regulatory factor-1 tumor suppressor protein by HPV E7 oncoprotein. Implication for the E7-mediated immune evasion mechanism in cervical carcinogenesis

In studying biological roles of interferon regulatory factor (IRF)-1 tumor suppressor in cervical carcinogenesis, we found that HPV E7 is functionally associated with IRF-1. Binding assays indicate a physical interaction between IRF-1 and HPV E7 in vivo and in vitro. The carboxyl-terminal transactivation domain of IRF-1 was required for the interaction. Transient co-expression of E7 significantly inhibits the IRF-1-mediated activation of IFN-beta promoter in NIH-3T3 cells. Co-transfection of E7 mutants reveals that the pRb-binding portion of E7 is necessary for the E7-mediated inactivation of IRF-1. It was next determined whether histone deacetylase (HDAC) is involved in the inactivation mechanism as recently suggested, where the carboxyl-terminal zinc finger domain of E7 associates with NURD complex containing HDAC. When trichostatin A, an inhibitor of HDAC, was treated, the repressing activity of E7 was released in a dose-dependent manner. Furthermore, the mutation of zinc finger abrogates such activity without effect on the interaction with IRF-1. These results suggest that HPV E7 interferes with the transactivation function of IRF-1 by recruiting HDAC to the promoter. The immune-promoting role of IRF-1 evokes the idea that our novel finding might be important for the elucidation of the E7-mediated immune evading mechanism that is frequently found in cervical cancer.

Antiproliferative effects of retinoic acid/interferon in cervical carcinoma cell lines: cooperative growth suppression of IRF-1 and p53

Retinoids and interferons have been implicated in the growth regulation of cervical cancer cells. However, the molecular mechanisms are not fully defined. To analyze detailed mechanisms, HPV-positive (HeLa, CaSki), HPV-negative (C33A, HT-3) and non-cervical Cos-1 cell lines were treated with I microM all-trans-retinoic acid (RA) and/or 10 ng/ml interferon-gamma (IFN-gamma). The growth of RA-treated HeLa cells was less effectively suppressed than that of IFN-gamma-treated ones. A combination of RA and IFN-gamma leads to an additive antiproliferative effect on the cell growth. CaSki cell growth was also inhibited by IFN-gamma but was little stimulated by RA treatment, and the IFN effect was attenuated when IFN-gamma was combined with RA. HPV-negative C33A and HT-3 cells, which are defective in p53 and Rb, and Cos- 1 cells were weakly or not responsive to all combined treatments. The molecular mechanism underlying the differential effects of RA/IFN on HeLa and C33A cells was investigated. Combined RA/IFN-gamma treatment caused a marked increase in the level of IFN regulatory factor-1 (IRF-1) in HeLa, whereas no induction of IRF-1 was observed in C33A, consistent with the findings that IFN signaling is functional in HeLa but is defective in C33A cells. The increase of p53 in HeLa cells might account for the down-regulation of HPV-18 E6 gene expression by RA/IFN-gamma. Furthermore, RA/IFN-gamma treatment resulted in the concurrent induction of p21WAF1 CDK inhibitor and dephosphorylation of Rb protein. Transient co-expression of IRF-1 and p53 led to the cooperative activation of the p21WAF1 promoter. Our results indicate that 2 transcription factors, increased in response to RA/IFN-gamma, cooperate functionally to regulate the cell cycle through the activation of a common p21WAF1 gene in HeLa cells.

Regulation of cell growth and HPV genes by exogenous estrogen in cervical cancer cells

Human papillomavirus (HPV) infection is known as the major cause of the development of cervical cancer. The E6 and E7 proteins of oncogenic HPV can play critical roles in immortalization and malignant transformation of cervical epithelial cells. From the previous epidemiologic data, it has been determined that long-term use of oral contraceptives may be a risk factor for cervical cancer. Investigation of the estrogenic and antiestrogenic effects on the proliferation of cervical cancer cells and the gene expression of HPV would help to explain the role of estrogen in the HPV-associated pathogenesis of cervical cancer. In this study, cervical cancer cells (HeLa, CaSki, and C33A) were cultured in vitro in the presence of 17beta-estradiol or tamoxifen to observe their regulatory growth effect and HPV E6/E7 gene expression. The estrogenic effect on the promoter activity of HPV URR was further confirmed by transient transfection assay, which was conducted in C33A cells using the HPV-18 URR-CAT reporter plasmid. The supplemental effect of estrogen receptors on URR promoter activity was also evaluated. The proliferation of HeLa and CaSki cells was stimulated by estradiol at physiologic concentration levels (</=1 x 10-6 M). At a low concentration (0.1 x 10-6 M), tamoxifen also stimulated the proliferation of HeLa and CaSki cells. In contrast to HPV-positive cervical cells, the proliferation of C33A was not influenced by exogenous estradiol or tamoxifen, indicating that HPV might play a role in the hormonal stimulation of cell growth. Interestingly, the proliferation of HeLa was markedly suppressed at high concentrations of estradiol and tamoxifen (5 and 10 x 10-6 M). The levels of HPV-18 E6 and E7 mRNA were significantly increased by estradiol at a concentration of 0.5 x 10-6 M. Transient transfection experiments using the HPV URR-CAT reporter plasmid in C33A cells indicated that the expression of HPV E6/E7 genes was increased by the treatment of estradiol and tamoxifen. Co-transfection of estrogen receptors (ER) and URR-CAT leads to a fourfold increase in CAT activity by estradiol or tamoxifen at physiologic concentrations. When estradiol or tamoxifen was administered at high concentrations (5 x 10-6 M), a DNA ladder, typically indicative of apoptosis, was observed in HeLa cells. In conclusion, estradiol stimulated the growth of HPV-positive cervical cancer cells, as did tamoxifen at low concentrations (0.1 x 10-6 M). The growth stimulation of HPV-positive cervical cancer cells by estrogen appeared to be related to the increased expression of HPV E6/E7. Growth suppression observed at high concentrations of estradiol and tamoxifen in HeLa cells might be a result of apoptosis. Taken together, these data suggested that exogenous estradiol might be a risk factor in HPV-mediated cervical carcinogenesis.

Mutational and functional analysis of HPV-16 URR derived from Korean cervical neoplasia

OBJECTIVE

The YY1 mutation has been suggested as one of the indicators that explains development of cervical neoplasia by episomal-type HPV. To extend this hypothesis, we examined whether a mutation(s) in the YY1 site is functionally related to the invasiveness of cervical neoplasia and the physical status of HPV DNA.

METHODS

The URR sequences were obtained by PCR amplification of HPV-16 genome from CIN and invasive cancer patients and cloned into pUC18 for sequencing and into pBLCAT8+ for functional CAT assay.

RESULTS

Our previous data classified HPV-infected patients into three groups: 3 cancer cases carrying episomal HPV DNA; 12 cancer cases carrying integrated HPV DNA; 12 CIN cases carrying episomal HPV DNA. The specific variants in HPV-16 URR were found in Korean women: G-->A transition at nt 7520 (100%, 27/27), A-->C transition at nt 7729 (70%; 19/27), and G-->A transition at nt 7841 (78%; 21/27). Selective mutations were observed at the YY1 binding sites of HPV-16 URR in the 3 patients with invasive cervical cancer who have the episomal forms of HPV-16 DNA: A-->C transition at nt 7484 and G-->A transition at nt 7488 (YY1-binding site 2; from 7481 to 7489). Additionally, C-->T transition at nt 7785 (YY1-binding site 3; from 7781 to 7790) was found in 2 of 3 patients. No YY1 site mutations were detected in the 12 CIN patients and in the HPV-integrated invasive cancer patients. To determine whether these mutations have effects on the expression of HPV E6/E7 genes driven by URR, the transient transfection assay was employed using URR-CAT reporter plasmid. The relative activities of three URR mutants from episomal HPV-16 DNA of cervical cancers were two- to fourfold higher than that of the HPV-16 URR prototype. In contrast, the URRs from integrated HPV-16 DNA in cervical cancer and from episomal HPV-16 DNA in CIN, where no mutation of the YY1 binding site was detected, showed similar levels of promoter activity to that of the URR prototype.

CONCLUSIONS

Our results support the hypothesis that the mutation at the YY1 binding site is functionally related to the development of cervical neoplasia caused by episomal HPV-16 DNA in Korean cervical cancer patients. Thus, mutation in the YY1 site of episomal HPV-16 URR may play a corresponding role of HPV integration in the progression of cervical cancer.

Recognition, targeting, and hydrolysis of the lambda O replication protein by the ClpP/ClpX protease

It has previously been established that sequences at the C termini of polypeptide substrates are critical for efficient hydrolysis by the ClpP/ClpX ATP-dependent protease. We report for the bacteriophage lambda O replication protein, however, that N-terminal sequences play the most critical role in facilitating proteolysis by ClpP/ClpX. The N-terminal portion of lambda O is degraded at a rate comparable with that of wild type O protein, whereas the C-terminal domain of O is hydrolyzed at least 10-fold more slowly. Consistent with these results, deletion of the first 18 amino acids of lambda O blocks degradation of the N-terminal domain, whereas proteolysis of the O C-terminal domain is only slightly diminished as a result of deletion of the C-terminal 15 amino acids. We demonstrate that ClpX retains its capacity to bind to the N-terminal domain following removal of the first 18 amino acids of O. However, ClpX cannot efficiently promote the ATP-dependent binding of this truncated O polypeptide to ClpP, the catalytic subunit of the ClpP/ClpX protease. Based on our results with lambda O protein, we suggest that two distinct structural elements may be required in substrate polypeptides to enable efficient hydrolysis by the ClpP/ClpX protease: (i) a ClpX-binding site, which may be located remotely from substrate termini, and (ii) a proper N- or C-terminal sequence, whose exposure on the substrate surface may be induced by the binding of ClpX.

Detection of p16 gene alteration in cervical cancer using tissue microdissection and LOH study

The p16 gene was identified as cyclin-dependent kinase inhibitor (CDKI) and this may negatively regulate the cell cycle by acting as a tumor suppressor. Using tissue microdissection, the molecular changes at p16 and Rb genes were analysed in the spectrum of disease from dysplasia to invasive cancer of the uterine cervix. Six of 27 (22%) cases informative for D9S171 and IFNA of 9p21-22 marker (p16INK4a) showed loss of one or both alleles in at least one of these loci. LOH of pRb was detected in 29% (5/17). Gene alterations at p16 and pRb loci were only detectable in some cases of HPV-16/18 DNA positive cervical cancer. Three cases demonstrated mutational changes of p16INK4a, and the alterations were determined to be G to T shift, suggesting transitional missense mutation. In summary, the inactivation of the p16/cdk-cyclin/Rb cascade may play an additional role during the malignant progression in HPV-16/18 positive cervical cancers.

The antibody response to HPV proteins and the genomic state of HPVs in patients with cervical cancer

Human papillomavirus (HPV) DNAs are often found to be integrated into the human genome in high-grade cervical intraepithelial neoplasia (CIN) as well as in invasive cervical cancers. Investigation of the relationship between the genomic status of specific HPV genes and their antibody responses to the virus-like particles (VLPs) of HPV-16 L1/L2 proteins and the in vitro translated HPV-16 E6 and E7 proteins may help to illustrate the mechanism of HPV-related cervical carcinogenesis and host immune response. Cervical cancer tissues obtained from 39 patients were studied to evaluate the physical status of HPV genes by Southern blotting, DNA-PCR, and RT-PCR of E2. The antibody response against the HPV-16 L1/L2 VLPs of serum specimens were tested by ELISA and the antibody response against the HPV-16 E6 and E7 proteins were tested by radioimmunoprecipitation assay (RIPA), respectively. Integrated forms of HPV-16 DNA were found in 23 of the 38 patients (60.5%). The HPV-16 positive cervical cancer patients showed a significantly higher prevalence rate (39.5%; 15/38) of antibodies to HPV-16 L1/L2 VLPs than that of the control group (8.7%; 2/28) (P < 0.05). Antibodies to HPV-16 L1/L2 VLPs were more commonly detectable in cervical cancer patients having the episomal form of HPV-16 DNA (pure episomal and mixed forms) (60%; 9/15) than in those who had only the integrated forms of HPV-16 DNA (26.1%; 6/23) (P < 0.05). Antibodies to E6 and E7 proteins were positive in 36.8% (14/38) and 50% (19/38) of the patients with HPV-16 positive cervical cancer, respectively. These were significantly higher than the positive rates for the control group (8.3% and 2.8%) (P < 0.05). The differences between sero-reactivities to E6 and E7 proteins in the patients with episomal forms of HPV-16 DNA and those with integrated forms of HPV-16 DNA were not statistically significant (P > 0.05). Integrated forms of HPV-16 DNA were prevalent in most patients with cervical cancer in Korea. Antibodies to HPV-16 L1/L2 VLPs, in vitro translated HPV-16 E6 and E7 proteins, appeared in a significantly larger proportion of the HPV-associated cervical cancer patients than in the controls. Antibodies to HPV-16 L1/L2 VLPs were more often detected in cervical cancer patients having the episomal form of HPV-16 DNA than in those having only integrated forms of HPV-16 DNA. Antibody responses to HPV-16 E6 and E7 proteins were not influenced by the different viral states.

The yeast Ada complex mediates the ligand-dependent activation function AF-2 of retinoid X and estrogen receptors

Nuclear receptors can function as ligand-inducible transregulators in both mammalian and yeast cells, indicating that important features of control of transcription have been conserved throughout evolution. Here, we report the isolation and characterization of a yeast protein that exhibits properties expected for a coactivator/mediator of the ligand-dependent activation function AF-2 present in the ligand-binding domain (LBD, region E) of the retinoid X (RXRalpha) and estrogen (ERalpha) receptors. This protein is identical to Ada3, a component of the yeast Ada coactivator complex. We demonstrate that: (1) the region encompassing residues 347-702 of Ada3 interacts with the LBD of RXRalpha and ERalpha in a ligand-dependent manner in yeast; (2) this interaction corresponds to a direct binding and requires the integrity of the core of the AF-2 activating domain (AF-2 AD) of both RXRalpha and ERalpha; (3) Ada3 as well as Ada2 and Gcn5, two other components of the Ada complex, are required for maximal AF-2 activity in yeast; and (4) Ada3 is able to enhance the AF-2 activity of RXRalpha and ERalpha when overexpressed in yeast and mammalian cells. Taken together, these data indicate that ligand-dependent transactivation by RXRalpha and ERalpha in yeast is mediated at least in part by the Ada complex, in which the Ada3 subunit directly binds to the holoreceptor LBD.

HPV-16-related proteins as the serologic markers in cervical neoplasia

OBJECTIVE

Recently, a variety of HPV-related proteins have been synthesized and their utility as diagnostic and prognostic markers in cervical cancers needs to be assessed. The ability to generate preparative amounts of HPV-16 L1/L2 VLPs and E6, E7 proteins may have implications for the development of a serologic assay to detect anti-HPV-16 virion immune responses. The purpose of the study is to improve the way of proper management of the cervical cancer by investigating the utility of the recently developed HPV-16 L1/L2 VLPs, HPV-16 E6, E7 proteins as the clinical serologic markers through antibody reactions by comparison with those of SCCA and CEA which have been used as tumor markers for cervical cancer.

METHODS

The serologic responses in Korean women with cervical neoplasia by ELISA using HPV-16 L1/L2 VLPs and radioimmunoprecipitation assay (RIPA) using in vitro translated HPV-16 E6, E7 proteins were investigated. PCR using E6 type-specific primers for HPV-16/18 was used to determine the presence and type of HPV infection (normal controls, 15 cases; preinvasive lesions, 28 cases; invasive cervical cancers, 124 cases).

RESULTS

The sera of 34% (42/124) of cervical cancers were positive for SCCA and the sera of 18% (22/124) of cervical cancers were positive for CEA. The positivity of SCCA was increased with advancing clinical stages, but the antibody levels were not correlated with clinical stage of disease. The sera of 7% (1/15) of normal controls, 39% (11/28) of preinvasive lesions, and 56% (70/124) of patients with cervical cancer were ELISA positive for HPV-16 L1/L2 VLPs (P < 0.05). The sera of 7% (2/28) of preinvasive lesions and 51% (63/124) of cervical cancers were positive for in vitro translated HPV-16 E6 protein (P < 0.05) and the sera of 11% (3/28) of preinvasive lesions and 33% (41/124) of cervical cancers were positive for in vitro translated HPV-16 E7 protein (P < 0.05). The antibody levels to HPV-16 E7 protein were correlated to clinical stage and tumor burden in a significant number of cervical cancers.

CONCLUSIONS

These data suggest that a considerable number of patients with cervical neoplasia generated positive antibody response to L1/L2 VLPs and in vitro translated E6, E7 proteins of HPV-16. These HPV-16-associated proteins might be disease-specific markers which could be useful in an adjunctive diagnostic assay and a seroepidemiologic study of HPV-related cervical neoplasia. In particular, the monitoring of antibody to HPV-16 E7 protein seems to be valuable in the proper management of cervical cancers for specific tumor markers.

Physical status and expression of HPV genes in cervical cancers

It is known that E2 protein of oncogenic human papillomavirus (HPV) inhibits the expression of E6 and E7 genes from their major promoters in vitro and suppresses the proliferation of cervical cancer cells. This suggests that the loss of functional E2 gene may provide selective advantages in the development of cervical cancer. Investigation of the relationship between the disruption of HPV-16/18 E2 genes by DNA integration and clinical outcome of cervical cancer may not only help to understand the mechanism of HPV-related cervical carcinogenesis, but may also provide novel management of cervical cancer. It was noted that integrated HPV-16/18 DNA was predominant in most patients with cervical cancers, marking 51 of a total of 68 cases (75%); episomal HPV DNAs were found in 5 cases (7.4%), and finally mixed forms of HPV DNAs with episome and integration were found in 12 cases (17.6%). Whole portions of E2 DNA of HPV-16 could be amplified by PCR in 19 (36.5%) of 52 cases of cervical intraepithelial neoplasia. It was shown that there was not statistically significant association with the different stages, but integrated HPV DNAs were detectable only in the patients with far-advanced stage of cervical cancers, which also means no episomal forms were detected. Episomal forms of HPV DNA were detectable in 14 (25.9%) of 54 squamous cell carcinomas (4 pure episomal forms and 10 mixed forms), whereas only 1 (8.3%) of 12 adenocarcinomas and adenosquamous cell carcinomas contained episomal viral DNA. When HPV DNA forms were compared with initial tumor size, lymphovascular space involvement, and frequency of nodal metastasis, statistically significant relationships were not found. The association of DNA integration with invasive cervical cancers was seen regardless of HPV type; however, there were differences between the integration profiles of HPV-16 and HPV-18 DNA. Of the 51 HPV-16-containing cancers, 36 (70.6%) revealed purely integrated HPV DNA, and another 10 cases (19.6%) displayed both integrated and episomal HPV DNAs. However, 5 (9.8%) cases showed only episomal copies of the HPV-16 genome. In contrast, all 17 HPV-18-containing cancers (5 cases positive for HPV-18 and 12 cases positive for both HPV-16 and -18) revealed only the integrated form of HPV-18 DNA. The expression of E6 and E7 transcripts of HPV-16/18 is uniformly correlated with the physical status of HPV DNAs. HPV E2 mRNAs were constantly expressed in the presence of the intact virus in cases with episome and mixed forms of HPV DNA. In general, amplified signals from HPV E2 RT-PCR are more intensive than those from DNA-PCR in the same patients. It is suggested that RT-PCR is a valuable method to evaluate dynamic expression of the specific gene and seems to be more sensitive than the DNA-PCR method in detecting intact E2 gene because of the gene copy numbers.

Cryptic single-stranded-DNA binding activities of the phage lambda P and Escherichia coli DnaC replication initiation proteins facilitate the transfer of E. coli DnaB helicase onto DNA

The bacteriophage lambda P and Escherichia coli DnaC proteins are known to recruit the bacterial DnaB replicative helicase to initiator complexes assembled at the phage and bacterial origins, respectively. These specialized nucleoprotein assemblies facilitate the transfer of one or more molecules of DnaB helicase onto the chromosome; the transferred DnaB, in turn, promotes establishment of a processive replication fork apparatus. To learn more about the mechanism of the DnaB transfer reaction, we investigated the interaction of replication initiation proteins with single-stranded DNA (ssDNA). These studies indicate that both P and DnaC contain a cryptic ssDNA-binding activity that is mobilized when each forms a complex with the DnaB helicase. Concomitantly, the capacity of DnaB to bind to ssDNA, as judged by UV-crosslinking analysis, is suppressed upon formation of a P x DnaB or a DnaB x DnaC complex. This novel switch in ssDNA-binding activity evoked by complex formation suggests that interactions of P or DnaC with ssDNA may precede the transfer of DnaB onto DNA during initiation of DNA replication. Further, we find that the lambda O replication initiator enhances interaction of the P x DnaB complex with ssDNA. Partial disassembly of a ssDNA:O x P x DnaB complex by the DnaK/DnaJ/GrpE molecular chaperone system results in the transfer in cis of DnaB to the ssDNA template. On the basis of these findings, we present a general model for the transfer of DnaB onto ssDNA or onto chromosomal origins by replication initiation proteins.