AGR2-Dependent Nuclear Import of RNA Polymerase II Constitutes a Specific Target of Pancreatic Ductal Adenocarcinoma in the Context of Wild-Type p53

BACKGROUND & AIMS

Promoted by pancreatitis, oncogenic KrasG12D triggers acinar cells' neoplastic transformation through acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia. Anterior gradient 2 (Agr2), a known inhibitor of p53, is detected at early stage of pancreatic ductal adenocarcinoma (PDAC) development. RNA polymerase II (RNAPII) is a key nuclear enzyme; regulation of its nuclear localization in mammalian cells represents a potential therapeutic target.

METHODS

A mouse model of inflammation-accelerated KrasG12D-driven ADM and pancreatic intraepithelial neoplasia development was used. Pancreas-specific Agr2 ablation was performed to access its role in pancreatic carcinogenesis. Hydrophobic hexapeptides loaded in liposomes were developed to disrupt Agr2-RNAPII complex.

RESULTS

We found that Agr2 is up-regulated in ADM-to-pancreatic intraepithelial neoplasia transition in inflammation and KrasG12D-driven early pancreatic carcinogenesis. Genetic ablation of Agr2 specifically blocks this metaplastic-to-neoplastic process. Mechanistically, Agr2 directs the nuclear import of RNAPII via its C-terminal nuclear localization signal, undermining the ATR-dependent p53 activation in ADM lesions. Because Agr2 binds to the largest subunit of RNAPII in a peptide motif-dependent manner, we developed a hexapeptide to interfere with the nuclear import of RNAPII by competitively disrupting the Agr2-RNAPII complex. This novel hexapeptide leads to dysfunction of RNAPII with concomitant activation of DNA damage response in early neoplastic lesions; hence, it dramatically compromises PDAC initiation in vivo. Moreover, the hexapeptide sensitizes PDAC cells and patient-derived organoids harboring wild-type p53 to RNAPII inhibitors and first-line chemotherapeutic agents in vivo. Of note, this therapeutic effect is efficient across various cancer types.

CONCLUSIONS

Agr2 is identified as a novel adaptor protein for nuclear import of RNAPII in mammalian cells. Also, we provide genetic evidence defining Agr2-dependent nuclear import of RNAPII as a pharmaceutically accessible target for prevention and treatment in PDAC in the context of wild-type p53.

High Expression of Human Telomerase Reverse Transcriptase in High-Grade Intraepithelial Neoplasia and Carcinoma of Uterine Cervix and Its Correlation With Human Papillomavirus Infection

Most of cervical intraepithelial neoplasia 1 (CIN 1) will regress and 12% to 40% of high-grade CIN may progress to squamous cell carcinoma (SCC) of the uterine cervix. However, the differentiation of CIN 1 and high-grade CIN is sometimes controversial among pathologists. Human telomerase reverse transcriptase (hTERT) is therefore applied to detect the differences among normal, CIN 1, high-grade CIN, and SCC tissues of uterine cervix. One hundred six cervical specimens were collected for immunohistochemical study of hTERT. These data were compared with the human papillomavirus (HPV) DNA status. Expression of hTERT in high-grade CIN increased significantly compared to that in CIN 1 ( P < .001). A positive relationship was found between high hTERT expression and degree of malignant transformation ( P < .001). Most of the cases with high hTERT expression tested positive for the high-risk HPV groups. High hTERT expression was detected in 88.73% of the samples with cervical high-grade CIN or SCC. Low hTERT expression was found in 94.29% of low-grade CIN or normal tissues. Furthermore, 96.92% of the cervical tissues with high hTERT expression were high-grade CIN or SCC. A total of 80.49% of samples with low hTERT expression were low-grade CIN or normal tissues. A significantly increased hTERT expression between CIN 1 and high-grade CIN exhibits a critical progression in cervical carcinogenesis. hTERT can be offered as additional molecular information correlated with more severe dysplasia and SCC. Furthermore, this increased hTERT expression is correlated whigh-risk HPVs infection.

Inhibition of Chronic Pancreatitis and Murine Pancreatic Intraepithelial Neoplasia by a Dual Inhibitor of c-RAF and Soluble Epoxide Hydrolase in LSL-KrasG¹²D/Pdx-1-Cre Mice

Mutation of Kirsten rat sarcoma viral oncogene homolog (KRAS) and chronic pancreatitis are the most common pathogenic events involved in human pancreatic carcinogenesis. In the process of long-standing chronic inflammation, aberrant metabolites of arachidonic acid play a crucial role in promoting carcinogenesis, in which the soluble epoxide hydrolase (sEH), as a pro-inflammatory enzyme, generally inactivates anti-inflammatory epoxyeicosatrienoic acids (EETs). Herein, we determined the effect of our newly-synthesized novel compound trans-4-{4-[3-(4-chloro-3-trifluoromethyl-phenyl)-ureido]-cyclohexyloxy}-pyridine-2-carboxylic acid methylamide (t-CUPM), a dual inhibitor of sEH and RAF1 proto-oncogene serine/threonine kinase (c-RAF), on inhibiting the development of pancreatitis and pancreatic intraepithelial neoplasia (mPanIN) in LSL-Kras(G12D)/Pdx1-Cre mice. The results showed that t-CUPM significantly reduced the severity of chronic pancreatitis, as measured by the extent of acini loss, inflammatory cell infiltration and stromal fibrosis. The progression of low-grade mPanIN I to high-grade mPanIN II/III was significantly suppressed. Inhibition of mutant Kras-transmitted phosphorylation of mitogen-activated protein kinase's kinase/extracellular signal-regulated kinases was demonstrated in pancreatic tissues by western blots. Quantitative real-time polymerase chain reaction analysis revealed that t-CUPM treatment significantly reduced the levels of inflammatory cytokines including tumor necrosis facor-α, monocyte chemoattractant protein-1, as well as vascular adhesion molecule-1, and the levels of Sonic hedgehog and Gli transcription factor (Hedgehog pathway). Analysis of the eicosanoid profile revealed a significant increase of the EETs/dihydroxyeicosatrienoic acids ratio, which further confirmed sEH inhibition by t-CUPM. These results indicate that simultaneous inhibition of sEH and c-RAF by t-CUPM is important in preventing chronic pancreatitis and carcinogenesis.

Overexpression of p16(INK4a) in urothelial carcinoma in situ is a marker for MAPK-mediated epithelial-mesenchymal transition but is not related to human papillomavirus infection

BACKGROUND

The role of human papillomavirus (HPV) in bladder carcinogenesis remains controversial. Overexpression of p16(INK4a), a surrogate marker for infection with oncogenic HPV in other tumours, has been described for urothelial carcinoma in situ (UCIS). Our goal was therefore to evaluate whether overexpression of p16(INK4a) is associated with HPV infection and to identify mechanisms of p16(INK4a) upregulation in UCIS.

MATERIALS AND METHODS

In 60 tissue specimens from a total of 45 patients (UCIS and controls), we performed p16(INK4a) immunohistochemistry followed by detection and subclassification of HPV DNA. In a subset of samples, we tested for gene amplification of p16(INK4a) applying fluorescence in situ hybridization (FISH). RAS/MAPK signalling and epithelial-mesenchymal transition (EMT) was assessed using immunohistochemistry. Finally, we transfected urothelial carcinoma cells with KRAS and examined the expression of p16(INK4a) as well as markers of EMT.

RESULTS

We found overexpression of p16(INK4a) in 92.6% of UCIS and in all cervical intraepithelial neoplasia (CIN) controls. In contrast, we detected high-risk HPV DNA in 80% of CIN, but none in UCIS. There was no gene amplification of p16(INK4a). High levels of phosphorylated kinases and urokinase plasminogen activator (uPA) and loss of membraneous E-cadherin were detected in UCIS. KRAS transfection of urothelial carcinoma cells led to upregulation of p16(INK4a) and uPA accompanied by loss of E-cadherin that could be inhibited by application of the kinase-inhibitor Sorafenib.

CONCLUSIONS

Our results show that overexpression of p16(INK4a) in UCIS is neither associated with HPV infection nor p16(INK4a) gene amplification but is a consequence of enhanced RAS/MAPK signalling that promotes EMT, possibly due to Sorafenib-sensitive paracrine secretion of the EMT activator uPA. These findings might open a novel therapeutic option for localized but aggressive urothelial cancer.

Phosphorylated c-Src is a novel predictor for recurrence in cervical squamous cell cancer patients

AIMS

The molecular mechanisms of the tumorigenesis and recurrence of cervical cancer are poorly understood. The objective of this study was to analyze the expression of phosphorylated c-Src (phospho-c-Src) and its clinical significance in human cervical cancer.

METHODS

The expression of phospho-c-Src was determined by immunohistochemistry in a total of 127 cervical specimens including 20 normal cervix tissues, 20 cases of carcinoma in situ of cervix (CIS), and 87 cases of cervical squamous cell carcinoma (CSCC).

RESULTS

The expression of phospho-Src in normal cervix, CIS, and CSCC increased gradually in ascending order (p=0.026). In addition, the expression of phospho-Src was correlated with overall (p=0.037) and recurrence (p=0.001) survival of cervical cancer. In multivariate Cox regression analysis, phospho-Src expression was an independent prognosis factor for recurrence-free survival (p=0.004).

CONCLUSION

Our present study suggests that Src signaling may play essential role in cervical cancer progression. Phospho-Src expression may be considered as a prognostic marker to predict recurrence in CSCC.

Heparanase and cyclooxygenase-2 gene and protein expressions during progression of oral epithelial dysplasia to carcinoma

Heparanase and cyclooxygenase-2 (COX-2) are 2 key enzymes that modulate diverse physiological processes during embryonic development and in adult life. Their deregulations have been implicated in the growth and progression of many cancer types. To date, comparatively little is known about the roles of these molecules during oral carcinogenesis. The aim of this study was to investigate the expression patterns of heparanase and COX-2 during progression of oral epithelial dysplasia (OED) to carcinoma. In situ hybridization and immunohistochemistry were performed on 5 cases of normal mucosa, 15 cases of OED, 5 cases of carcinoma in situ and/or microinvasive carcinoma, and 40 cases of oral squamous cell carcinoma (OSCC). Results demonstrated that heparanase and COX-2 messenger RNA and protein were absent in normal oral mucosa but were coexpressed in increasing intensity as OED progressed to OSCC. Concomitant heparanase- and COX-2-positive staining in the stromal cells suggests that OED/OSCC progression may be modulated by stromal-cancer cell interactions. Diffuse intense staining of poorly differentiated OSCC compared with staining localized to tumor nest periphery in well- and moderately differentiated OSCC suggests that heparanase and COX-2 overexpressions correlated with tumor grade. Strong expression of these enzymes in tumor cells at the advancing front suggests a role in local tumor spread. These results, taken together, suggest that heparanase and COX-2 might play complementary roles in the stepwise progression of OED to carcinoma.

[Expression of ERK1/2 MAPK signaling transduction pathway in esophageal cancers in Kazakh patients]

OBJECTIVE

To investigate the expression variation and significance of ERK1/2 MAPK signaling transduction pathway in the pathogenesis of esophageal squamous cell carcinoma (ESCC) in Kazakh patients.

METHODS

The expression level of p-ERK1/2 after serum starvation and treatment with U0126 inhibitor was detected in esophageal cancer cell line EC9706 by Western blot assay. The mRNA level of total ERK1/2 (t-ERK1/2) and expression level of t-ERK1/2 and p-ERK1/2 proteins of 25 pairs of ESCC and adjacent normal esophageal mucosal tissues of Kazakh patients were examined and identified by real-time quantitative PCR (qRT-PCR) and Western blotting, respectively. The expression of p-ERK1/2 protein was verified by immunohistochemistry in 126 paraffin-embeded specimens, including 19 normal esophageal mucosa, 55 esophageal carcinomas in situ and 52 invasive carcinomas.

RESULTS

ERK1/2 MAPK signaling transduction pathway was in an active status in the EC9706 cells. The expression level of p-ERK1/2 in Ec9706 cells reached a peak at 10 min after transient serum stimulation, and p-ERK1/2 expression was totally restrained after the treatment with 50 µmol/L U0126. In the 25 pairs of ESCC and adjacent normal mucosa, the t-ERK1 mRNA level was 1.92 ± 3.49 in the ESCC tissues and 3.67 ± 7.47 in the adjacent normal mucosa. The t-ERK1 mRNA level in ESCC tissues was significantly lower than that in adjacent normal mucosa (P < 0.05), whereas there was no significant difference of t-ERK2 mRNA level between them(P > 0.05). The expression levels of p-ERK1 and p-ERK2 proteins were 0.87 ± 0.14 and 0.79 ± 0.10 in the ESCC tissues, and 1.10 ± 0.13 and 1.32 ± 0.12 in the adjacent normal mucosae. p-ERK1/2 protein in the ESCC tissues was significantly lower than that in the adjacent normal tissue (P < 0.01). However, there was no significant difference between their t-ERK1/2 protein levels (P > 0.05). In the 126 cases of paraffin-embeded specimens, positive expressions of both p-ERK1 and p-ERK2 in esophageal cancer tissues were 7.7% (4/52), significantly lower than those in adjacent normal mucosa (31.6%, 6/19) and carcinoma in situ (85.5%, 47/55, P < 0.05).

CONCLUSIONS

ERK1/2 MAPK signaling pathway is in an active status in esophageal cancer and adjacent normal mucosa. Our results imply that the activation of p-ERK1/2 MAPK signaling transduction pathway plays a role in the early pathogenesis of ESCC in Kazakh patients.

Overexpression of 5-lipoxygenase in sporadic colonic adenomas and a possible new aspect of colon carcinogenesis

PURPOSE

We aimed to study the intracellular expression of 5-lipoxygenase (5-LOX), the primary competitor with cyclooxygenase-2 in arachidonic acid metabolism, as inflammatory enzymes may be involved in blocking apoptosis and promoting cancer growth by changing arachidonic acid metabolism within cells. Our purpose was to investigate the possible connection between 5-LOX expression and colon carcinogenesis by characterizing 5-LOX expression in histologically different colonic adenomas, determining the relationship between high expression of 5-LOX and various conventional clinicopathological features of adenomas, and finally characterizing the histological localization of cells with 5-LOX overexpression.

METHODS

A total of 111 patients were examined and 120 histologically different colonic adenomas analyzed (including four cases of intramucosal adenocarcinoma in a polyp). Immunohistochemical staining with polyclonal anti-5-LOX antibodies was performed.

RESULTS

There was a significant correlation between high 5-LOX expression and patient age, increased polyp size, high grade of intraepithelial neoplasia, villous and tubulovillous adenoma, and histological epithelial localization.

CONCLUSIONS

We observed a strong positive correlation between 5-LOX overexpression and the appearance of typical high-risk factors for malignant transformation in adenomatous polyps. The results support the role of 5-LOX in early stages of colon carcinogenesis.

Aurora kinase A in Barrett's carcinogenesis

In Barrett's mucosa, both aneuploidy and TP53 mutations are consistently recognized as markers of an increased risk of Barrett's adenocarcinoma. Overexpression of the mitotic kinase encoding gene (AURKA) results in chromosome instability (assessed from the micronuclei count) and ultimately in aneuploidy. Eighty-seven esophageal biopsy samples representative of all the phenotypic lesions occurring in the multistep process of Barrett's carcinogenesis (gastric metaplasia in 25, intestinal metaplasia in 25, low-grade intraepithelial neoplasia in 16, high-grade intraepithelial neoplasia in 11, and Barrett's adenocarcinoma in 10) were obtained from long segments of Barrett's mucosa. Twenty-five additional biopsy samples of native esophageal mucosa were used for control purposes. In all tissue samples, the immunohistochemical expression of both AURKA and TP53 gene products was scored; and the micronuclei index was calculated. AURKA immunostaining increased progressively and significantly along with dedifferentiation of the histologic phenotype (P < .001). Nine of 10 Barrett's adenocarcinomas showed AURKA immunostaining. AURKA expression correlated significantly with p53 expression and the micronuclei index (both Ps < .001). AURKA overexpression is significantly associated with Barrett's mucosa progressing to Barrett's adenocarcinoma and contributes to esophageal carcinogenesis via chromosome instability. The identification of AURKA as a novel molecular target of cancer progression in Barrett's mucosa provides a lead for the development of new therapeutic approaches in Barrett's mucosa patients.

COX-2 localization within plasma membrane caveolae-like structures in human lobular intraepithelial neoplasia of the breast

Cyclooxygenase-2 (COX-2) is highly expressed in human intraepithelial neoplasia of the breast and takes part in the molecular pathway implicated in progression of breast cancer. Recently, we demonstrated that COX-2 protein is mainly located in plasma membrane of lobular intraepithelial neoplasia (LIN) cells suggesting a localization in caveolae-like structures. The aim of the present study is to establish subcellular locations of COX-2 and its colocalization with caveolin-1 (CAV-1) to caveolae structures in LIN. To establish a relationship between COX-2 and CAV-1, 39 LINs were studied by immunohistochemistry and confocal microscopy analysis. COX-2 and CAV-1 expression was observed respectively in 79.5 and in 94.9% of LIN studied. A positive correlation was found between membrane COX-2 staining pattern and CAV-1 expression, while no correlation was found between cytoplasm COX-2 staining pattern and CAV-1. Confocal analysis showed that COX-2 localized to plasma membrane was strictly associated to CAV-1 suggesting that an amount of COX-2 protein is placed in caveolae-like structures. Our results show that COX-2 is localized within caveolae compartment and colocalized with CAV-1 protein in LIN lesions. Because caveolae are rich in signaling molecules, this COX-2 compartment may play an important role in diverse breast cancer carcinogenesis processes.

Expression of orotate phosphoribosyltransferase (OPRT) in hepatobiliary and pancreatic carcinoma

The purpose of this study was to clarify the role of orotate phosphoribosyltransferase (OPRT) in the progression of hepatobiliary and pancreatic carcinomas. Representative sections from 8 surgically resected pancreatic carcinomas, 5 gallbladder carcinomas and 19 hepatocellular carcinomas (HCCs) were examined microscopically. Sites of pancreatic intraepithelial neoplasia (PanIN) were counted, and histologic subtypes of invasive ductal carcinoma of the pancreas (IDC) were determined. Gallbladder carcinomas and HCCs were examined histologically, and the subtypes and spread patterns were assessed. Expression of OPRT was examined immunohistochemically. A total of 75 PanINs were identified. Expression of OPRT increased as lesions progressed from early to high-grade PanINs (PanIN-1A and -1B versus PanIN-2 and -3, p=0.0004). Three (37.5%) of the 8 pancreatic IDCs were positive for OPRT. In the remaining 5 cases, OPRT was expressed only in the neoplastic ducts adjacent to PanIN-3s. In gallbladder carcinomas, mucosal neoplastic epithelium showed dense cytoplasmic expression in 4 of the 5 cases, but expression was absent in the deeply invasive lesions. Among HCCs, 15 of the 19 cases were negative for OPRT in the central area of the tumor, but 8 of the 19 cases expressed OPRT in vascularly invasive lesions. Our data suggest that OPRT is involved in early events of pancreatic and gallbladder carcinogenesis and invasion of HCC.

Stromal cells associated with early invasive foci in human mammary ductal carcinoma in situ coexpress urokinase and urokinase receptor

The transition from ductal carcinoma in situ (DCIS) of the breast to invasive ductal carcinoma is facilitated by proteolytic degradation of basement membrane. The transition can be identified as microinvasive foci in a small proportion of DCIS lesions. We have previously found that MMP-13 is frequently expressed in such foci. To establish whether plasmin-directed proteolysis is likely to be involved in early invasion, we have here studied the expression of urokinase plasminogen activator (uPA) and its receptor (uPAR) in human DCIS lesions with and without microinvasion. uPA mRNA was detected in periductal stromal cells in all of 9 DCIS lesions with microinvasion and in 2 of 9 DCIS lesions without microinvasion by in situ hybridization. The uPA mRNA signal was seen in numerous stromal cells in microinvasive areas together with MMP-13 mRNA expressing cells. Double immunofluorescence analyses, using emission fingerprinting, showed that the uPA expressing stromal cells included both myofibroblasts and macrophages. The early invasive carcinoma cells were negative for uPA. uPAR immunoreactivity was focally upregulated in periductal stromal cells in all of the 9 DCIS lesions with microinvasion and in only 2 of the 9 DCIS lesions without microinvasion. uPAR was seen in both macrophages and myofibroblasts in microinvasive areas, and it was evident that uPA and uPAR colocalized in both fibroblast-like cells and macrophage-like cells. We conclude that periductal macrophages and myofibroblasts are strongly involved in the initial steps of breast cancer invasion by focally upregulating the expression of the plasminogen activation system and MMP-13.

Expression of nm23, MMP-2, TIMP-2 in breast neoplasm in Zhengzhou Center Hospital, China

BACKGROUND

In recent years, the carcinoma of the breast threatens to women's health heavily. Invasion and metastasis is the main reason that results in the patients death.

OBJECTIVE

A prospective study is made in the center hospital of zhengzhou, in order to approach the expression of nm23, MMP-2 (Matrix metallo-proteinase-2), TIMP-2 (it's tissue-inhibitor of the metalloproteinase-2) in the breast neoplasm and the relationship with invasion and metastasis.

METHODOLOGY

This study applied the immunohistochemistry technique SP method

RESULTS

In fibroadenoma, ductal carcinoma in situ and invasive ductal carcinoma of the breast 4 groups, the positive immunostaining rate of nm23, MMP-2 and TIMP-2 have significant difference among 4 groups (p < 0.05). In the breast invasive ductal carcinoma, the expression of nm23 and TIMP-2 decreased or the expression of MMP-2 increased

CONCLUSION

This suggested that invasion and metastasis is ability of the neoplasm. MMP-2 in the breast ductal carcinoma in situ appears of high expression and this suggested that the positive expression of this onco-proteins was the early incident in the genetic course of the breast cancer The unite detection of nm23, MMP-2 and TIMP-2 expression would contribute to the early diagnosis and prognostic assessment of the carcinoma of the breast.

PLCγ contributes to metastasis of in situ-occurring mammary and prostate tumors

Phospholipase C-gamma (PLCgamma) has been implicated in tumor cell motility required for invasiveness and metastasis. Diminished tumor dissemination has been demonstrated in xenograft models, but studies in naturally-occurring tumors are lacking, having been limited by the timing of the interventions. Therefore, we generated mice that express a doxycycline (DOX)-inducible dominant-negative fragment of PLCgamma, PLCz; this approach avoids the in utero lethality caused by the absence of PLCgamma. As we targeted two de novo-occurring carcinomas of the mammary (MMTV-driven polyoma middle T antigen model, PyVmT) and prostate (TRAMP model) glands, we limited expression to these epithelial cells by driving DOX transactivator from the prostatein C3 promoter. This avoids the confounding variable of potentially abrogating motility in stromal and endothelial cells. These mice developed normally in the presence of DOX, except for limited mammary development if treated before 6 weeks and immaturity of the prostate gland if treated before 2 weeks of age. DOX-mediated induction of PLCz from age 8 to 16 weeks in PyVmT mice decreased the number of lung metastases by >10-fold (P<0.06) without a detectable effect on in situ tumor cell proliferation or tumor size. Lung metastases were also significantly decreased in the TRAMP model in which the mice expressed the PLCz fragment (P<0.05). DOX treatment itself had no effect on tumor size or metastasis in control mice, nor did it affect tumor dissemination in nontransgenic littermates. In conclusion, abrogation of the PLCgamma signaling pathway can limit the metastatic potential of carcinomas.

The association between intratubular seminoma and invasive germ cell tumors☆

Intratubular seminoma (ITS) has been defined as the complete filling of the seminiferous tubules with seminoma cells with no Sertoli cells present. This contrasts with intratubular germ cell neoplasia, unclassified (IGCNU), where the malignant germ cells are interspersed by Sertoli cells. We aimed to determine the relationship between these 2 entities and the association between ITS and invasive classic seminomas. We therefore examined the morphology and immunochemistry of ITS and IGCNU adjacent to germ cell tumors to differentiate the patterns, frequency, and distribution of these lesions. We found that ITS was seen in equal frequency adjacent to seminomas as it was to nonseminomas. The presence of ITS in non-seminomatous germ cell tumors suggests that it is a true in situ lesion rather than representative of intratubular spread of an existing seminoma. However, because it is not specifically associated with seminoma, we suggest that it is not useful to discriminate this lesion from IGCNU and that it merely represents an advanced form of IGCNU on the way to invasive malignancy.

Matrix Metalloproteinase 26 Proteolysis of the NH2-Terminal Domain of the Estrogen Receptor β Correlates with the Survival of Breast Cancer Patients

Estrogens have many cellular functions, including their interactions with estrogen receptors alpha and beta (ERalpha and ERbeta). Earlier, we determined that the estrogen-ER complex stimulates the transcriptional activity of the matrix metalloproteinase 26 (MMP-26) gene promoter. We then determined that ERbeta is susceptible to MMP-26 proteolysis whereas ERalpha is resistant to the protease. MMP-26 targets the NH(2)-terminal region of ERbeta coding for the divergent NH(2)-terminal A/B domain that is responsible for the ligand-independent transactivation function. As a result, MMP-26 proteolysis generates the COOH-terminal fragments of ERbeta. Immunohistochemical analysis of tissue microarrays derived from 121 cancer patients corroborated these data and revealed an inverse correlation between the ERalpha-dependent expression of MMP-26 and the levels of the intact ERbeta in breast carcinomas. MMP-26 is not expressed in normal mammary epithelium. The levels of MMP-26 are strongly up-regulated in ductal carcinoma in situ (DCIS). In the course of further disease progression through stages I to III, the expression of MMP-26 decreases. In contrast to many tumor-promoting MMPs, the expression of MMP-26 in DCIS correlated with a longer patient survival. Our data suggest the existence of an MMP-26-mediated intracellular pathway that targets ERbeta and that MMP-26, a novel and valuable cancer marker, contributes favorably to the survival of the ERalpha/beta-positive cohort of breast cancer patients.

Enzymes of estrogen metabolism in endometrial cancer

Activities of estrogen metabolism enzymes (aromatase, 2- and 4-estrogen hydroxylases, catechol-O-methyltransferase, and glutathione transferase) were studied by modern biochemical methods in tumors of patients with endometrial cancer. Relationships between enzyme activities and body weight index, age of menarche, stage of the disease, tumor histotype, differentiation degree, and depth of invasion into the myometrium were detected. The detected relationships between enzyme activities and serum concentrations of estradiol and progesterone and level of estrogen receptors in tumor tissue attest to hormone dependence of aromatase, estrogen hydroxylases, and glutathione transferase.

Expression of COX-2 in normal and pyelonephritic kidney, renal intraepithelial neoplasia, and renal cell carcinoma

OBJECTIVES

The role of inflammation in carcinogenesis is unknown. To determine the relationship between cyclooxygenase 2 (COX-2) expression, inflammation, and carcinogenesis in human renal cell carcinoma (RCC), we looked for COX-2 expression in normal and pyelonephritic kidney, renal intratubular neoplasia (RIN), and RCC tissues.

METHODS

COX-2 expression was assessed immunohistochemically in tissues obtained from 20 pyelonephritic kidneys, 16 normal kidneys, 19 RIN, and 75 RCC cases.

RESULTS

COX-2 expression was found to be positive in 64% of RCCs. It was positive in 13 chronic pyelonephritic (65%), 9 normal (56%), and 15 RIN (79%) cases. COX-2 expression was significantly higher in RCC and RIN than the normal and pyelonephritic cases (p<0.001 and p<0.001, respectively). No statistically significant difference was noted between RCC and RIN cases.

CONCLUSIONS

Although the function of COX-2 in tumor development has not been exactly elucidated, the increased expression of COX-2 in RIN and RCC might be a factor that may play a role in the development of RIN or progression to RCC, which warrants further research.

Telomerase Expression in Noncancerous Bronchial Epithelia Is a Possible Marker of Early Development of Lung Cancer

Centrally located lung cancers in smokers frequently associated with subsequent primary tumors. We evaluated the telomerase expression chronologically in noncancerous epithelia as a risk factor of susceptibility to lung cancer development. Telomerase protein expression was examined in situ by immunohistochemistry in 26 noncancerous bronchial epithelia adjacent to centrally located early-stage lung cancers in sequential 23 patients treated by photodynamic therapy or surgery among 206 patients who underwent autofluorescence bronchoscopy from 1997 to 2003. Among the 15 lesions in 12 patients treated by photodynamic therapy alone, 11 lesions achieved complete remission after photodynamic therapy, and none of their noncancerous bronchial epithelia was telomerase positive. On the contrary, in the remaining four lesions, either recurrence or secondary lung cancer developed adjacent to the successfully treated primary cancer within 26 months, and the telomerase protein expression in noncancerous epithelia was detected before the secondary cancer development (P &lt; 0.001). The overall relationship of human telomerase reverse transcriptase positivity in noncancerous epithelia and subsequent lung cancer development, including patients treated by radiation or surgery, showed higher significance (P &lt; 0.0001). Histologically “normal” bronchial epithelia in smokers may unphysiologically express telomerase as a field, and such epithelia are likely susceptible to develop lung cancer. We propose that ectopic expression of telomerase in bronchial epithelia may precede transformation in human lung cancer development and that detection of telomerase protein in noncancerous bronchial epithelia will become a useful marker detecting high-risk patients for lung cancer development.

DAPK promotor methylation is an early event in colorectal carcinogenesis

Death-associated protein kinase (DAPK) is frequently inactivated by promotor hypermethylation in various human cancers. At present, little is known about the significance of DAPK inactivation in colorectal carcinogenesis. We therefore, investigated macrodissected samples of 22 formalin-fixed and paraffin-embedded T1-carcinomas showing normal colon mucosa, intraepithelial neoplasia and carcinoma tissue on the same slice. Dissected carcinoma areas showed a higher frequency of DAPK promotor methylation (81.2%) compared to intraepithelial neoplasia (68.2%). Colon mucosa adjacent to intraepithelial neoplasia or carcinoma showed DAPK promotor methylation in only two of eight cases (25%). We suggest that DAPK promotor hypermethylation may play an important role in the early steps of tumor progression in colorectal carcinoma.

5-Lipoxygenase, a Marker for Early Pancreatic Intraepithelial Neoplastic Lesions

Pancreatic cancer has an abysmal prognosis because of late diagnosis. Therefore, it is important to identify risk factors if we are to be able to prevent and detect this cancer in an early, noninvasive stage. Pancreatic intraepithelial neoplasias (PanIN) are the precursor lesions which could be an ideal target for chemoprevention. This study shows up-regulation of 5-lipoxygenase (5-LOX) in all grades of human PanINs and early lesions of pancreatic cancer in two different animal models (EL-Kras mice and N-nitrosobis(2-oxopropyl)amine-treated hamsters) by immunohistochemistry. The results were consistent in all tissues examined, including seven chronic pancreatitis patients, four pancreatic cancer patients, one multiorgan donor, nine EL-Kras mice, and three N-nitrosobis(2-oxopropyl)amine-treated hamsters, all with PanINs. Overexpression of 5-LOX in NIH3T3 cells resulted in greater sensitivity of these cells to the growth inhibitory effects of the 5-LOX inhibitor Rev5901. These findings provide evidence that 5-LOX plays a key role in the development of pancreatic cancer. Furthermore, the lipoxygenase pathway may be a target for the prevention of this devastating disease.

Cyclooxygenase-2 expression associated with severity of PanIN lesions: a possible link between chronic pancreatitis and pancreatic cancer

BACKGROUND

Cyclooxygenase-2 (COX-2) is a key modulatory molecule in inflammation and neoplasia. Increasing evidence suggests a role for COX-2 in pancreatic cancer (PAC). However, expression of COX-2 in pancreatic intraepithelial neoplasia (PanIN), the precursor lesion of PAC which is often present in chronic pancreatitis (CP), has received little attention.

METHOD

COX-2 immunostaining was performed on sections of PAC (n = 26), CP (n = 34), PanIN (n = 68) and normal pancreas (n = 11). Sections were also stained for macrophages (CD68), activated pancreatic stellate cells (alphaSMA), and collagen (Sirius Red) as markers of fibrosis. Semiquantitative scoring was based on the extent and intensity of immunostaining.

RESULTS

COX-2 expression was increased in PAC compared to normal (p = 0.02) with 89% of cases exceeding COX-2 immunostaining in normal ducts. In PanIN lesions, COX-2 expression increased with escalating severity of the PanIN change (p < or = 0.01). COX-2 expression was increased in PanIN-2/3 compared to normal pancreas and CP (p < or = 0.001). In ducts of CP, COX-2 expression did not differ from that in normal tissue. There was no association between COX-2 expression and clinicopathological variables.

CONCLUSION

The high level of COX-2 expression in PanIN lesions suggests that this enzyme could be a therapeutic target at a non-invasive stage of pancreatic carcinogenesis and feasible for chemoprevention in CP.

Biological inferences from a mathematical model of comedo ductal carcinoma in situ of the breast

The growth of a tumour in a duct is examined in order to model ductal carcinoma in situ (DCIS) of the breast, the earliest known stage of breast cancer. Interactions between the expansive forces created by tumour cell proliferation and the stresses that develop in the compliant basement membrane are studied using numerical and analytical techniques. Particular attention focuses on the impact that proteolytic enzymes have on the tumour's progression. As the tumour expands and the duct wall deforms, the tumour cells are subjected to mechanical and nutritional stresses caused by high pressures and oxygen deprivation. Such stresses may stimulate the cells to produce proteolytic enzymes that degrade the duct wall, making it more compliant and prone to penetration by the tumour cells. We use our model to compare these two hypotheses for enzyme production and find that mechanical stress is likely the dominant mechanism, with the wall deforming most at the centre of the duct. We then discuss the biological implications of our theoretical results and suggest possible directions for future work.

Ductal carcinoma in situ of the breast and heparanase-1 expression: A molecular explanation for more aggressive subtypes

BACKGROUND

Ductal carcinoma in situ of the breast (DCIS) forms a heterogeneous group of lesions with varying invasive potential. This study tested whether heparanase-1 (HPR1), an endoglycosidase that specifically degrades the heparan sulfate (HS) proteoglycans in the breast extracellular matrix, was associated with the most aggressive DCIS subtypes.

STUDY DESIGN

Fifty-seven DCIS specimens and 10 normal breast specimens were examined for HPR1 expression using immunohistochemical staining. Twenty-seven arbitrarily selected specimens were also examined for HS deposition by immunofluorescence staining, confirming HPR1 activity. Patient medical records were obtained to explore a possible association between biologic potential using Van Nuys Prognostic Index (VNPI) and HPR1 expression.

RESULTS

Twenty-one (75%) of 28 comedo and microinvasive DCIS specimens stained HPR1 positive; 4 (14%) of 29 other subtypes (papillary, cribriform, and solid subtypes) stained HPR1 positive on immunohistochemistry (p = 0.003). Among 27 DCIS stained for HS, we found that 8 (67%) of 12 HPR1-negative DCIS had intact HS deposition in the extracellular basement membrane; none of the 15 HPR1-positive DCIS stained HS positive. Six (86%) of seven DCIS with VNPI scores 8 to 9 and 14 (50%) of 28 DCIS with VNPI scores 5 to 7 were HPR1 positive; only 3 (17%) of 18 DCIS with VNPI scores 3 to 4 were HPR1 positive. Median VNPI score in patients with HPR1-positive DCIS was 7 (range 3 to 9), compared with 4.5 (range 3 to 7) in patients with HPR1-negative DCIS (p < 0.001).

CONCLUSIONS

HPR1 was expressed at a significantly higher frequency in the invasive comedo and DCIS with microinvasion subtypes than in the noninvasive subtypes. HPR1 expression was inversely associated with HS deposition in the extracellular basement membrane of the DCIS. HPR1 expression was associated with a higher VNPI score. These observations suggest that HPR1 expression in DCIS can play an important role in development of DCIS into an invasive breast cancer.

Activation of the ERK/MAP kinase pathway in cervical intraepithelial neoplasia is related to grade of the lesion but not to high-risk human papillomavirus, virus clearance, or prognosis in cervical cancer

We subjected 302 archival samples (150 squamous cell carcinomas [SCCs] and 152 cervical intraepithelial neoplasia [CIN] lesions) to immunohistochemical staining with extracellular signal-regulated kinase-1 (ERK1) antibody and human papillomavirus (HPV) testing with 3 primer sets. Follow-up data were available for all SCC cases and 67 CIN cases. High-risk (HR) HPV types were associated with CIN (odds ratio [OR], 19.12; 95% confidence interval [CI], 2.31-157.81) and SCC (OR, 27.25; 95% CI, 3.28226.09). There was a significant linear relationship between lesion grade and ERK1 staining intensity (P = .0001). ERK1 staining was a 100% specific indicator of CIN, with a 100% positive predictive value, but a poor predictor of HR HPV. ERK1 expression did not predict clearance or persistence of HR HPV after CIN treatment. ERK1 staining did not significantly predict survival in cervical cancer in univariate (P = .915) or multivariate analysis. After adjustment for HR HPV, stage, age, and tumor grade in the Cox regression model, only stage (P = .0001) and age (P = .002) remained independent prognostic factors. ERK1 expression seems to be an early marker of cervical carcinogenesis. ERK1 overexpression is not a specific marker of HR-HPV in CIN and cervical cancer, nor does it predict virus clearance after CIN treatment or disease outcome in cervical cancer.

The centrosomal kinase Nek2 displays elevated levels of protein expression in human breast cancer

Aneuploidy and chromosome instability are common abnormalities in human cancer. Loss of control over mitotic progression, multipolar spindle formation, and cytokinesis defects are all likely to contribute to these phenotypes. Nek2 is a cell cycle-regulated protein kinase with maximal activity at the onset of mitosis that localizes to the centrosome. Functional studies have implicated Nek2 in regulation of centrosome separation and spindle formation. Here, we present the first study of the protein expression levels of the Nek2 kinase in human cancer cell lines and primary tumors. Nek2 protein is elevated 2- to 5-fold in cell lines derived from a range of human tumors including those of cervical, ovarian, breast, prostate, and leukemic origin. Most importantly, by immunohistochemistry, we find that Nek2 protein is significantly up-regulated in preinvasive in situ ductal carcinomas of the breast as well as in invasive breast carcinomas. Finally, by ectopic expression of Nek2A in immortalized HBL100 breast epithelial cells, we show that increased Nek2 protein leads to accumulation of multinucleated cells with supernumerary centrosomes. These data highlight the Nek2 kinase as novel potential target for chemotherapeutic intervention in breast cancer.

Sequential expression of inducible nitric oxide synthase and cyclooxygenase-2 during DMBA-induced hamster buccal pouch carcinogenesis

BACKGROUND

Although it is known that iNOS and COX-2 are abundantly expressed in oral premalignant and malignant lesions, respectively, the interaction between iNOS and COX-2 has not been extensively studied. The purpose of this study was to examine the alteration of the iNOS and COX-2 expression level during hamster buccal pouch (HBP) carcinogenesis.

MATERIALS AND METHODS

The expression of both iNOS and COX-2 on normal, dysplastic mucosa and squamous cell carcinoma (SCC) from different differentiation stages in 7, 12-dimethylbenz[a]anthracene (DMBA)-induced HBP carcinogenesis was examined using immunohistochemical analysis.

RESULTS

The mean values of both iNOS and COX-2 expression increased gradually from control to dysplastic lesions and more to invasive SCC. The highest mean expression was SCC. The differences between both iNOS and COX-2 expression in the normal and that in the dysplastic and carcinoma lesions were statistically significant.

CONCLUSION

The results suggest that iNOS can enhance its ability to promote tumor growth in cooperation with COX-2. The expression of iNOS and COX-2 may be one of the factors that contribute to oral carcinogenesis.

[Elevated expression of matrix metalloproteinase-9, and fibronectin concentration in recurrent epithelial ovarian cancer]

INTRODUCTION

Ovarian cancer is the leading cause of mortality from gynecologic malignancies in developed countries. However, the outcome of apparently similar cases with regard to histology and stage is highly variable. In contrast to carcinomas of parenchymal organs such as the breast, lung, and colon, the spread of the epithelial ovarian carcinomas is characterized by transcoelomic dissemination of tumor cells into the peritoneal cavity. Matrix metalloproteinases, and fibronectin play an important role in this process.

OBJECTIVES AND METHODS

The authors made an attempt to predict recurrence of ovarian cancer by comparing the clinico-pathologic characteristics, grading and biological behavior of the ovarian malignancies with the matrix metalloproteases activities and fibronectin expression. This study involved 17 patients with epithelial ovarian cancers, 5 patients with benign ovarian tumours, 5 patients with normal ovaries, 5 patients with ovarian tumours of low malignant potential, 4 patients with sex-cord stromal ovarian tumours and 2 patients with germ cell ovarian tumours. Matriolytic activity was detected in the surgically removed tumours, in serum and in ascites by gelatin zymography and quantitative assessment was performed by using densitometric scanning wih an Eagle Eye II (Stratagenic CA. USA). MMP-2 and MMP-9 activity was expressed in arbitrary units (U) per 10 g of ovarian cancer tissue. Fibronectin content was identified by Western blot analysis and quantity estimated by densitometric analysis. The-median follow-up period was 20.5 months.

RESULTS

Activated forms of matrix metalloproteinase-2,-and-9 were not detected in normal ovaries. The expression levels of MMP-2 and MMP-9 were higher in epithelial ovarian cancers than in benign ovarian tumors, but the differences were not statistically significant. The MMP-9 activity was markedly elevated in advanced-stage and poorly-differentiated ovarian cancer compared to early-stage and well-differentiated ovarian malignancy. This relationship was not observed with regard to MMP-2 activity. The fibronectin concentration was significantly higher in ovarian cancers compared with benign ovarian tumors and normal ovaries. Fibronectin concentration significantly elevated in ovarian cancer patients with recurrent disease compared with ovarian cancer patients without recurrence. In patients with recurrent ovarian cancer the activated forms of MMP-9 were significantly higher compared to ovarian cancers without recurrence.

CONCLUSION

In conclusion, our data support the hypothesis that the expression of tumor-derived matriolytic enzymes and fibronectin are important in the growth of ovarian tumours. The interaction of MMP-9 with fibronectin appears to be one of the key factors in the biology of epithelial ovarian cancers.

Overexpression of cyclooxygenase-2 is associated with breast carcinoma and its poor prognostic factors

Cyclooxygenase is the rate-limiting enzyme that catalyzes the conversion of arachidonic acid to prostaglandins. The inducible form, cyclooxygenase-2, is known to be overexpressed in various human cancers including the colon, stomach, and urinary bladder. In this study, we evaluated the overexpression of cyclooxygenase-2 in 64 cases of breast cancer and correlated the results with clinicopathologic parameters. Immunohistochemical staining for cyclooxygenase-2 demonstrated positivity of the tumor cells in 46 of 64 cases (72%). Cyclooxygenase-2 overexpression was significantly correlated with larger tumor size and advanced clinical stage. Cyclooxygenase-2 overexpression tended to be more frequently observed in cases with presence of lymph node metastasis and in cases without expression of estrogen and progesterone; however, there was no significant correlation statistically. Nuclear and histologic grade were not well correlated with cyclooxygenase-2 overexpression. When ductal carcinoma in situ was considered separately, 32 of 42 cases (76%) were positive for cyclooxygenase-2. We conclude that cyclooxygenase-2 is up-regulated in a high proportion of breast cancers. The overexpression of cyclooxygenase-2 was associated with larger tumor size and advanced clinical stage, although lymph node status, estrogen and progesterone expression, and nuclear and histologic grade were not significantly correlated. Therefore, cyclooxygenase-2 overexpression may be a feature of the aggressive phenotype and may be useful as a prognostic indicator in breast cancer.

Thioredoxin is associated with proliferation, p53 expression and negative estrogen and progesterone receptor status in breast carcinoma

We investigated the expression of thioredoxin and thioredoxin reductase in a large set of breast invasive and in situ carcinomas by immunohistochemistry. Additionally, NF-kappa B, p53 and proliferating cell nuclear antigen (PCNA) expression was studied. Thioredoxin and thioredoxin reductase expression was located in both cytoplasmic and nuclear compartments of the cell. Cytoplasmic thioredoxin positivity was found in 67 % and nuclear in 59 % of the cases, while thioredoxin reductase was found in 55 % and 6 % of cases, respectively. Ductal carcinomas showed stronger cytoplasmic thioredoxin immunoreactivity than lobular ones. Nuclear thioredoxin positivity was more often found in in situ lesions, and lobular carcinomas were more often negative than ductal ones. Both cytoplasmic and nuclear thioredoxin-positive cases had a high proliferation measured by PCNA staining. Positive nuclear immunostaining was associated with negative estrogen and progesterone receptor status. Cases with high p53 expression showed significantly higher nuclear thioredoxin positivity, but lower thioredoxin reductase positivity. Whilst thioredoxin or thioredoxin reductase was not associated with patient survival, cases showing both cytoplasmic and nuclear thioredoxin reductase-positive tumours had a shorter disease-free interval than those with negative immunostaining.

Elevated hTERT mRNA levels: A potential determinant of bronchial squamous cell carcinoma (in situ)

Expression levels of hTERT mRNA were investigated by RT-PCR in tissue specimens of patients with (Group A) and without (Group B) clinically overt bronchial carcinoma, respectively. Bronchial carcinoma (n = 9) and distant normal (n = 9) specimens were analyzed in Group A. The chance of carcinoma seemed to increase with increasing hTERT mRNA levels (OR = 6.04, 95% CI = 1.02-37). Group B was comprised of 21 patients who underwent autofluorescence bronchoscopy. After analysis of 66 bronchial biopsies the chance of prevalent carcinoma in situ or carcinoma increased with increasing hTERT mRNA levels (OR = 6.19, 95% CI = 1.55-25). Variables like age, gender, smoking history, history of cancer within the airways or the degree of lymphocyte infiltrate in the specimens did not modify this relation. In 7 Group B patients in whom bronchial cancer was diagnosed during follow-up, biopsies taken before cancer diagnosis from both the area of the newly developed tumor and distantly from this area had been analyzed for hTERT expression. The median hTERT mRNA level in the biopsies from the area of future cancer was significantly higher than in biopsies taken from distant sites (p < 0.03). These data indicate that elevated hTERT mRNA is associated with an increased relative risk of prevalent and incident bronchial squamous cell carcinoma (in situ).

Expression of stratum corneum chymotryptic enzyme in ichthyoses and squamoproliferative processes

OBJECTIVE

Stratum corneum chymotryptic enzyme (SCCE) is a serine protease, which is thought to play a role in the desquamation of skin via the proteolysis of desmosomes in the stratum corneum. The objective of this study was to investigate the expression of SCCE in ichthyoses and squamoproliferative processes, conditions in which the shedding and replacement of epidermal cells is disrupted.

DESIGN

Tissue samples from cases of Netherton's syndrome, congenital ichthyosiform erythroderma, ichthyosis vulgaris, actinic keratosis, squamous cell carcinoma in situ, and invasive squamous cell carcinoma were examined for expression of SCCE using immunohistochemistry.

MAIN OUTCOME MEASURES

The slides were qualitatively analyzed for the expression of SCCE by a certified dermatopathologist.

RESULTS

In all disease states, we found that the expression of SCCE was absent in areas of parakeratotic stratum corneum of normal thickness. In areas of mixed orthokeratosis and parakeratosis where the stratum corneum was greatly thickened as might correspond clinically to a cutaneous horn, SCCE staining was either absent or focally aggregated without regard to orthokeratosis or parakeratosis. Of note, complete absence of SCCE expression was not observed in any of the cases of ichthyosis examined, nor was there increased expression of SCCE in the atypical cells of the squamoproliferative disorders.

CONCLUSIONS

These results suggest that SCCE is abnormally expressed in skin where epidermal cell kinetics are disrupted due to inherited and acquired defects. Further investigation is needed to determine causality between the abnormal expression of SCCE and the altered cell kinetics in these diseases.

Expression of cyclooxygenase-2 in malignant and benign breast tumors

Cyclooxygenase-2 (COX-2) is reported to play an important role in carcinogenesis. We examined COX-2 expression in patients with breast cancer and benign breast tumors. Immunohistochemical staining revealed a high level of COX-2 expression in malignant lesions of invasive ductal carcinoma (IDC) at a rate of 40% and a low level of expression in 15% of adjacent normal-appearing breast epithelia. Similarly, in ductal carcinoma in situ (DCIS), a high level of COX-2 expression was found in 80% of malignant lesions and a low level of expression in 50% of normal epithelia. Reverse transcriptional polymerase chain reaction (RT-PCR) performed in 7 of these cases disclosed that COX-2 expression was restricted to the malignant lesion. Further, all 10 cases of fibroadenoma and 10 cases of intraductal papilloma, both of which are benign tumors, had a high level of COX-2 expression. When overexpression of COX-2 was analyzed in relation to the clinicopathological features of the patients, no characteristic correlation was noted. Our results demonstrated that COX-2 is expressed in mammary tissue during tumorigenesis of the breast gland, suggesting that the cyclooxygenase isoenzyme may be a target for the prevention and treatment of breast cancer.

Cyclooxygenase-2 expression is related to nuclear grade in ductal carcinoma in situ and is increased in its normal adjacent epithelium

Cyclooxygenase-2 (COX-2) is emerging as an important cancer biomarker and is now an experimental target for solid tumor treatment.However, no study has exclusively focused on COX-2 expression in early lesions such as ductal carcinoma in situ (DCIS). We examined COX-2 expression by immunohistochemistry in 46 cases of women undergoing surgical resection for DCIS. We found that COX-2 expression was detected in 85% of all DCIS specimens, with increased COX-2 staining correlating with higher nuclear grade. Strikingly, COX-2 staining intensity in the normal adjacent epithelium was stronger than in the DCIS lesion itself. Our observations demonstrate that COX-2 is up-regulated in the normal adjacent epithelium and supports the hypothesis that the surrounding epithelial tissue is part of the disease process in DCIS.

In situ production of estrogens in human breast carcinoma

Recent studies have demonstrated that biologically active estrogens are locally produced from circulating inactive steroids in the estrogen-dependent breast carcinoma. The in situ production of estrogens in the breast carcinoma is considered to play an important role in the proliferation of breast cancer cells, especially in the postmenopausal women. Therefore, the total blockade of this pathway may inhibit estrogenic actions in breast cancer tissues and lead to an improvement in the prognosis in these patients. In this review, we describe the recent studies concerning the expression of enzymes related to intratumoral estrogen production, including aromatase, 17beta-hydroxysteroid dehydrogenase, steroid sulfatase, and estrogen sulfotransferase in human breast carcinoma tissues, and discuss the biological significance of local production of estrogens in human breast cancer.

Overexpression of the receptor tyrosine kinase Tie-1 intracellular domain in breast cancer

OBJECTIVE

Tyrosine kinase with immunoglobulin and epidermal growth factor homology domains (Tie-1) is a receptor tyrosine kinase that regulates angiogenesis and antiapoptotic survival signaling. Tie-1 expression is generally associated with endothelial cells and neovascularization. We previously identified Tie-1 in human breast tumor samples using a PCR-based screen for protein kinases expressed in breast tumors. The purpose of this study was to determine the cell types expressing Tie-1, whether Tie-1 is expressed in tumor cells, and to examine the regulation of Tie-1 in breast cancer.

METHODS

Tie-1 expression was analyzed by Western blot and immunohistochemistry using an antibody to the carboxy terminus of Tie-1. Tie-1 expression was determined in a variety of cancer cell lines, clinical breast and colon tumor samples, and in corresponding benign tissue from the same patient. Tie-1 expression and distribution in breast tumors was scored by immunohistochemistry.

RESULTS

Tie-1 was overexpressed in 14/23 breast tumors compared with 0/9 corresponding normal tissues from the same patients. Immunohistochemistry revealed that Tie-1 was overexpressed in epithelial breast cancer cells and ductal carcinoma in situ. In all breast tumor samples, Tie-1 was expressed as a truncated 40- to 43-kD doublet consisting of the intracellular portion of the protein, which contains the tyrosine kinase catalytic domain. The 40- to 43-kD Tie-1 doublet was expressed in a broad variety of cell lines.

CONCLUSIONS

We have shown that breast cancer cells overexpress a cleaved form of the Tie-1 protein. Our results implicate the intracellular domain of Tie-1, which includes the catalytic kinase domain, in breast cancer progression.

Focal adhesion kinase as a marker of malignant phenotype in breast and cervical carcinomas

Integrins mediate cell adhesion to extracellular matrix and stimulate signals involved in cell proliferation, survival, and migration. Focal adhesion kinase (FAK) is considered the central molecule in integrin-mediated signaling. Previously, FAK has been implicated in invasive tumor behavior based on Northern or Western blot (immunoblot) using total tumor tissue homogenates. We used immunohistochemistry to demonstrate FAK expression in benign cervical epithelium, dysplasia, carcinoma in situ (CIS), and invasive cervical squamous cell carcinomas (SCCs), as well as in benign breast tissue, atypical ductal hyperplasia, and ductal carcinoma in situ (DCIS) and invasive carcinomas of the breast. We also used polymerase chain reaction to analyze whether infection with the high-risk human papillomavirus (HPV) subtypes correlated with FAK overexpression in CIS of the cervix. We found minimal FAK expression in benign cervical and breast epithelium and in low-grade squamous dysplasia (CIN I and CIN I-II) of the cervix, and variable FAK expression in CIS lesions of the cervix (10 of 14 cases). Most of the invasive SCCs of the cervix (13 of 16 cases) and DCIS of the breast (6 of 8 cases) were positive for FAK. Surprisingly, all DCIS of the breast were also strongly positive (7 of 7). Only 3 of 13 cases of atypical ductal hyperplasia were focally positive for FAK. Regardless of the intensity of FAK staining, all CIS of the cervix were positive for either HPV 16 or 18. We conclude that FAK overexpression is not restricted to invasive phenotype, but rather appears to be a marker for malignant transformation.

Elevated focal adhesion kinase expression facilitates oral tumor cell invasion

BACKGROUND

Understanding the molecular mechanisms of metastasis is critical with respect to oral tumorigenesis. The focal adhesion kinase (FAK) is an intracellular tyrosine kinase associated with the regulation of cell growth, migration, and survival. The purpose of the current study was to determine whether elevated FAK expression in oral malignancies was associated with increased invasiveness and oral carcinoma.

METHODS

Immunohistochemical analysis was used to assess levels of FAK expression in archived oral carcinoma tissue samples. Invasion assays after transfections were used to assess the effect of increased FAK expression on invasive potential of oral tumor cells.

RESULTS

The human oral carcinoma cell line SCC25 was significantly more invasive (P < 0.05) and expressed higher levels of FAK compared with the less invasive human oral carcinoma cell line SCC15. FAK expression was 3.0-fold higher in the SCC15 cell line and 5.0-fold higher in the SCC25 cell line compared with normal epithelial cells. In the highly invasive SCC25 cell line, FAK expression was 1.5-fold higher compared with the less invasive SCC15 cell line. FAK immunostaining in oral tumors was significantly more intense compared with the immunostaining in surrounding normal epithelium or chronic mucositis. Overexpression of FAK in low-invading SCC15 cells resulted in a 4.5-fold increase in the rate of invasion compared with untransfected or neotransfected control SCC15 cell lines and a nearly 1.5-fold greater rate compared with the highly invasive untransfected SCC25 cell line.

CONCLUSIONS

The current results suggest that enhanced expression of FAK in oral carcinoma cells may lead to a selective growth advantage and increased invasive potential of the primary oral tumor.

Cyclooxygenase 2 expression in pancreatic adenocarcinoma and pancreatic intraepithelial neoplasia: an immunohistochemical analysis with automated cellular imaging

We immunohistochemically examined material from 36 pancreata (adenocarcinomas, 30 lesions; pancreatic intraepithelial neoplasia [PanIN], 65; normal pancreatic ducts, 30) for cyclooxygenase 2 (COX-2) with an automated platform. We analyzed 7 to 10 discrete foci and generated an average percentage of positive cells and average staining intensity for each lesion. These 2 values were then multiplied to create an overall "HistoScore" for each lesion. COX-2 demonstrated considerable heterogeneity of expression between and within cases. The overall average percentage of positive cells in adenocarcinomas was 47.3%; in PanINs, 36.3%; and in normal ducts, 19.2%. COX-2 was expressed in more than 20% of cells in 23 adenocarcinomas (77%), 42 PanINs (65%), and 12 normal ducts (40%). The overall average HistoScore for adenocarcinomas was 6.1; for PanINs, 5.4; and for normal ducts, 3.5. Significant differences in COX-2 expression were demonstrable in adenocarcinomas vs normal ducts, PanINs vs normal ducts, and PanIN 2/3 vs PanIN 1a/1b. In general, the pattern of COX-2 expression increased from normal to PanIN to adenocarcinoma. The up-regulation of COX-2 in a subset of noninvasive precursor lesions makes it a potential target for chemoprevention with selective COX-2 inhibitors.

Telomerase activity and hTERT mRNA in development and progression of adenoma to colorectal cancer

Telomerase activity and hTERT mRNA expression are upregulated in colorectal cancer. Whether they are inherent in colorectal adenomas, premalignant lesions to cancer, however, remains to be elucidated. We examined telomerase activity by the fluorescence-based telomeric repeat amplification protocol method and analyzed the level of hTERT mRNA by real-time polymerase chain reaction in 74 surgically obtained neoplasms from 29 patients. The specimens were divided into 6 categories according to the criteria of the Vienna Classification. The control comprising 29 non-pathological mucosa were classified into category 1, 6 adenomas indefinite for neoplasia into category 2, 21 non-invasive low grade adenomas into category 3, 23 high grade adenomas or non-invasive carcinomas into category 4, and 15 intramucosal or submucosal carcinomas into category 5. Carcinoma invading beyond the submucosa (9 samples) was referentially subdivided into category 6. Telomerase activity (mean +/- standard error) in 1 categories to 6 were 5.0+/-1.2, 1.8+/-1.7, 4.3+/-1.6, 20.2+/-2.1, 36.4+/-5.5, and 55.5+/-8.2 units/microg protein, respectively. There were no statistical differences between categories 1 and 2, 1 and 3, and 2 and 3. A significant statistical difference in the other two was observed by the multiple comparison test. The mean levels of hTERT mRNA was 103.1+/-102.4, 103.6+/-103.0, 103.6+/-102.9, 103.7+/-102.9, 104.0+/-103.4, and 104.4+/-104.0 copies/microg total RNA, respectively. There was a significant statistical difference only between category 6 and each of the other categories. These results suggest that telomerase activation occurs during the progression from low-grade to high-grade dysplasia in adenomas and increases steadily with the progression of the degree of dysplasia and invasion during colorectal carcinogenesis, and that hTERT mRNA expression is a feature of the late stage development of colorectal cancer.

Expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase in cervical intraepithelial neoplasia

Angiogenesis contributes to the growth and secondary spreading of solid tumors. Platelet-derived endothelial cell growth factor (PD-ECGF)/thymidine phosphorylase (TP) has been identified as such an angiogenic factor. In this study, the expression of PD-ECGF/TP and VEGF was evaluated by immunohistochemical staining of tumor specimens from 40 patients with cervical intraepithelial neoplasia (10 with moderate dysplasia; 10 with severe dysplasia; 10 with carcinoma in situ; 10 with invasive carcinoma). The microvessel density was assessed by immunostaining for factor VIII-related antigen in the most highly neovascularized area. In both the nucleus and cytoplasm, the intensity of PD-ECGF/TP expression in carcinoma in situ and invasive carcinoma was significantly stronger than that in moderate dysplasia. However, the intensity of VEGF expression was not significantly different in the various specimens. The microvessel density in mild dysplasia was significantly different from that in carcinoma in situ (p<0.05), and that in invasive carcinoma (p<0.05). There was no significant relationship between the microvessel density and the expression of PD-ECGF/TP or that of VEGF. These results show that the expression of PD-ECGF/TP appears to be involved in the promotion of angiogenesis in cervical intraepithelial neoplasia.

Increased membrane type 1 matrix metalloproteinase expression from adenoma to colon cancer: a possible mechanism of neoplastic progression

PURPOSE

Membrane type 1 matrix metalloproteinase is a membrane-associated matrix metalloproteinase central to the degradation of basement membrane components via the activation of matrix metalloproteinase-2. Although membrane type 1 matrix metalloproteinase is overexpressed in invasive colon cancer, its expression in colonic polyps and carcinoma in situ has not been defined. In addition, the association of membrane type 1 matrix metalloproteinase expression by a primary tumor and recurrence of colon cancers has not been examined.

METHODS

Immunoperoxidase staining was performed on randomly selected specimens containing adenoma (n = 17), carcinoma in situ (n = 9), or metastatic colon carcinoma (n = 8) with mouse monoclonal antibody to human membrane type 1 matrix metalloproteinase. Similar staining was also performed on randomly selected node-negative colon cancers that recurred within five years of resection (n = 17), matched for age, gender, stage, grade, and vascular, lymphatic, and perineural invasion, and node-negative colon cancers that did not recur within five years of resection (n = 17). Staining for membrane type 1 matrix metalloproteinase was graded. Mean scores for the groups were compared by Wilcoxon test.

RESULTS

We found a progressive and significant increase in the mean score of membrane type 1 matrix metalloproteinase from normal mucosa to adenoma (P < 0.001), carcinoma in situ (P < 0.006), and invasive cancer (P < 0.009). However, there was no difference in membrane type 1 matrix metalloproteinase expression between the recurrent and nonrecurrent groups of node-negative colon cancer (P = not significant).

CONCLUSIONS

These data suggest that membrane type 1 matrix metalloproteinase expression increases with progression from normal mucosa to invasive adenocarcinoma; however, it cannot be used as a prognostic indicator on which adjuvant therapy is based in node-negative colon cancer because of its failure to predict recurrence in this patient group.

Cyclooxygenase-2 expression in human breast cancers and adjacent ductal carcinoma in situ

Cyclooxygenase-2 (COX-2) is an inducible enzyme that converts arachidonic acid to prostaglandins. Overexpression of the COX-2 gene in mammary glands of transgenic mice was sufficient to induce tumorigenesis. We analyzed COX-2 expression in human breast cancers (and breast cancer cell lines) and adjacent ductal carcinoma in situ (DCIS) as well as its association with HER2/neu and clinicopathological variables. Archival primary breast carcinomas (n = 57), adjacent DCIS (n = 14) and DCIS alone (n = 2) were analyzed for COX-2 and HER2 expression by immunohistochemistry using specific monoclonal antibodies. An immunohistochemical scoring system was used. HER2 gene amplification had been analyzed previously by fluorescence in situ hybridization (n = 20). Histology of carcinomas included infiltrating ductal (n = 44), lobular (n = 2), and other (n = 7). Frozen breast cancers and adjacent normal tissue pairs (n = 9) were analyzed for COX-2 mRNA by reverse transcription-PCR. COX-2 and HER2 expression were also analyzed in human breast cancer cell lines (MCF-7, MCF-7/HER2, SK-BR-3, and MDA-MB-231) by immunoblotting. Cytoplasmic COX-2 expression was detected at an intermediate or high level in epithelial cells in 18 of 42 (43%) invasive breast cancers and in 10 of 16 (63%) cases of DCIS. Normal-appearing breast epithelia adjacent to cancer expressed COX-2 in 81% of cases and was generally focal and of similar or decreased intensity relative to adjacent neoplastic epithelia. COX-2 mRNA was detected in all samples analyzed by reverse transcription-PCR and was increased in eight of nine breast cancers relative to paired normal tissue. In archival tumors, no significant correlation was found between COX-2 and HER2 expression/amplification and clinicopathological variables. COX-2 expression was induced in MCF-7 cells stably transfected with HER2, in contrast to parental MCF-7 cells, and was detected in MDA-MB-231, but not SK-BR-3 cells. COX-2 is frequently overexpressed in invasive breast cancers and in adjacent DCIS and, thus, may be an early event in mammary tumorigenesis. Forced HER2 expression in MCF-7 cells was shown to up-regulate COX-2, although no association was found in human tumors. Our results suggest that nonsteroidal anti-inflammatory drugs and selective COX-2 inhibitors may be useful in the chemoprevention and therapy of human breast cancer.

Reduced Fhit expression occurs in the early stage of esophageal tumorigenesis: no correlation with p53 expression and apoptosis

The FHIT gene, encompassing the FRA3B fragile site at chromosome 3p14.2, is a candidate tumor suppressor gene involved in multiple tumors, including esophageal carcinoma. We analyzed Fhit expression using an immunohistochemical method in invasive carcinoma, carcinoma in situ (CIS) and dysplasia, in paraffin sections of 75 esophageal squamous cell carcinomas (ESCs) to further elucidate the role of Fhit protein in esophageal carcinogenesis. In addition, we also examined whether Fhit expression correlated with p53 expression and apoptosis. Compared to adjacent normal mucosa, significant loss or reduction of Fhit expression was noted in 67 of 75 (89.3%) invasive ESCs, in 13 of 19 (68.4%) CIS lesions, and in 10 of 23 (43.5%) dysplastic lesions. There was a progressive loss or reduction of Fhit expression with progressive increases in the severity of histopathological changes (p < 0.001). However, there was no association between Fhit expression and clinicopathological findings, including tumor stage, lymph node metastasis, or overall survival. Moreover, Fhit expression was not significantly associated with p53 expression and apoptosis. These results indicate that abnormal Fhit expression is a common event in the early stage of ESC development and may occur independently of p53 expression and apoptosis mechanisms.

Effect of epidermal growth factor receptor tyrosine kinase inhibition on epithelial proliferation in normal and premalignant breast

The factors controlling epithelial proliferation in ductal carcinoma in situ (DCIS) are unclear. Antiestrogens are effective in the prevention of the majority of estrogen receptor-positive, but not estrogen receptor (ER)-negative breast cancers, which suggests that other factor(s) are promoting proliferation in ER-negative DCIS. Mutated or overexpressed tyrosine kinases are frequently associated with tumor development. Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is involved with mitogenesis and is expressed in ER-negative DCIS. We hypothesized that EGFR is central in driving proliferation in ER-negative/EGFR-positive DCIS. The purpose of this study was to establish whether the EGFR tyrosine kinase inhibitor (EGFR-TKI), ZD1839 (Iressa), can reduce epithelial proliferation and increase apoptosis in EGFR-positive DCIS. Breast tissue from 16 women undergoing surgery for DCIS were implanted into 16-32 immunosuppressed mice/experiment (8 xenografts/mouse). Treatment commenced 2 weeks after implantation and consisted of once daily oral gavage with ZD1839 at doses ranging from 10 to 200 mg/kg for 14-28 days; appropriate controls were present. Xenografts were removed on days 14, 21, 28, and 42 after implantation and then assessed for proliferation (LI) by Ki67 immunostaining and apoptosis index (AI) by morphology. All Ps reported are two-sided. Overall, a 56% reduction in epithelial proliferation was seen with Iressa in EGFR-positive DCIS. EGFR-TK inhibition compared with vehicle controls resulted in a fall in Geometric Mean Labeling Index (LI) after 14 days (day 28) of treatment both in ER-negative/EGFR-positive DCIS [6.5% interquartile range (IQR, 3.8-11.1) versus 13.9% (IQR, 12.0-16.3%); F(1,3) = 103; P = 0.002] and ER-positive/EGFR-positive DCIS [4.6% (IQR, 3.9-5.2%) versus 11.7% (IQR, 9.2-15.5); F(1,2) = 32.3; P = 0.03]. EGFR-TK inhibition had similar effects on the "at risk" normal breast epithelium adjacent to DCIS in the treated epithelium LI day 28 [ZD1839 2.2% (IQR, 1.7-3.3%) compared with control 3.8% (IQR, 2.4-5.4%); F(1,14) = 29.2; P = 0.00009] and in addition increased epithelial apoptotic index at day 21 [ZD1839 0.38 (0.23-0.83) compared with control 0.19 (0.1-0.25); F(1,6) = 12.2; P = 0.013]. The effect on epithelial proliferation was still significant after 28 days of treatment [for both DCIS (F1,29) = 24; P = 0.039 and normal breast F(1,6) = 47.3; P = 0.0005]. EGFR-TK inhibition with ZD1839 offers a novel approach to the treatment of EGFR-positive DCIS, regardless of ER status, and provides a potential new chemopreventative approach in patients at high risk of breast cancer.

Collagenase-3 expression in breast myofibroblasts as a molecular marker of transition of ductal carcinoma in situ lesions to invasive ductal carcinomas

Collagenase-3 (matrix metalloproteinase 13; MMP-13), a protease originally identified in breast carcinoma, is characterized by a potent degrading activity against a wide spectrum of extracellular matrix proteins. The aims of this study were to localize and identify the MMP-13-expressing cells in invasive human breast carcinoma and to evaluate the role of MMP-13 in transition to invasive lesions by studying ductal carcinoma in situ (DCIS). We found expression of MMP-13 in stromal fibroblast-like cells in all 21 invasive ductal carcinomas studied and in 4 of 9 invasive lobular carcinomas. In most carcinomas, expression of MMP-13 was limited to small stromal foci in the tumor area. Combined in situ hybridization and immunohistochemistry showed coexpression of alpha-smooth muscle actin immunoreactivity and MMP-13 mRNA in myofibroblasts. In contrast, cytokeratin-positive cancer cells, alpha-smooth muscle actin-positive vascular smooth muscle cells, CD68-positive macrophages, and CD31-positive endothelial cells were all MMP-13 mRNA negative. In situ hybridization for MMP-13 in 17 DCIS lesions revealed expression in 10 cases. Immunohistochemical analysis of all DCIS cases identified microinvasion in 8 of the 17 lesions. Seven of the eight lesions with microinvasion were MMP-13 positive. Further analysis showed that MMP-13 expression was often associated with the microinvasive events. This particular expression pattern was unique for MMP-13 among other MMPs analyzed, including MMP-2, -11, and -14. We conclude that MMP-13 is primarily expressed by myofibroblasts in human breast carcinoma and that expression in DCIS lesions often is associated with microinvasive events. On the basis of these data, we propose that MMP-13 may play an essential role during transition of DCIS lesions to invasive ductal carcinomas.

MnSOD expression is less frequent in tumour cells of invasive breast carcinomas than in in situ carcinomas or non-neoplastic breast epithelial cells

Manganese superoxide dismutase (MnSOD) is an antioxidant enzyme capable of neutralizing superoxide anion molecules. In previous studies it has been suggested to suppress both tumour proliferation and apoptosis. This study investigated 65 invasive, 50 in situ and 19 benign hyperplastic breast lesions for its immunohistochemical expression. MnSOD expression was also tested with in situ hybridization. To study cell proliferation, apoptosis and their association with MnSOD expression the neoplastic breast lesions were immunostained with a monoclonal antibody to Ki-67 and the extent of apoptosis in them was determined by the TUNEL method. 32/65 (49%) of the invasive ductal carcinomas, 41/50 (82%) of the in situ and 15/19 (79%) of the benign hyperplasias expressed the MnSOD protein. There were significantly more MnSOD positive cases in in situ carcinoma and in benign hyperplasia than in invasive carcinoma (p=0.00016 and p=0.022, respectively). Positivity was also more frequently found in non-neoplastic ductal and acinar epithelial cells than in invasive carcinoma. On the other hand, neoplastic epithelial cells of invasive and in situ carcinoma showed strong positivity more often than the epithelial cells of benign hyperplasia or non-neoplastic epithelium. In breast lesions, MnSOD positivity did not associate with proliferation or apoptosis. The lower frequency of MnSOD positive cases in invasive breast carcinoma suggests that the lack of its expression might contribute to the development of an invasive breast carcinoma phenotype and that it could in this way operate as a tumour suppressor gene, as previously suggested.