Expression of oestrogen receptor and oestrogen-inducible genes pS2 and ERD5 in large bowel mucosa and cancer

Cytosolic Levels of An Estrogen-Induced Breast Cancer-Associated Peptide (TFF1/pS2) in Colorectal Cancer: Clinical Significance and Relationship with Steroid Receptors

Background

The Trefoil Factor 1 (TFF1/pS2), a peptide consisting of 60 amino acids, is the most abundant estrogen-induced messenger RNA in MCF-7 breast cancer cells and is also expressed by colorectal carcinomas. The objective of this work was to evaluate the cytosolic TFF1 content in colorectal carcinomas, its possible relationship with estrogen and progesterone receptors as well as with clinicopathological tumor parameters, and its potential prognostic significance.

Methods

Cytosolic TFF1 levels were examined by immunoradiometric assay in 178 patients with resectable colorectal cancer. The mean follow-up period was 32 months.

Results

There was a wide variability of cytosolic TFF1 levels in tumor-surrounding mucosa samples (0.09-42.5 ng/mg protein) as well as in tumors (0.01-270 ng/mg protein). Comparison of paired mucosa and carcinoma samples showed significantly higher TFF1 levels in tumors (mean: 17.1 ng/mg protein) than in mucosa samples (10 ng/mg protein) (p=0.027). TFF1 levels were significantly higher in mucosa samples surrounding distal colon and rectal tumors (p=0.0001) and in tumor samples obtained from older patients (p=0.007). However, there were no significant differences in tumor TFF1 levels with respect to clinicopathological parameters such as the patient's sex, tumor location, stage, histological grade, ploidy, S-phase, or tumor estrogen and progesterone receptors. In addition, there was no significant relationship between tumor TFF1 levels and disease outcome.

Conclusions

TFF1 may play an as yet undetermined role in the tumorigenesis of colorectal carcinomas. However, cytosolic levels of TFF1 do not seem to have any prognostic significance in colorectal carcinomas.

Sustained expression of steroid receptor coactivator SRC-2/TIF-2 is associated with better prognosis in malignant pleural mesothelioma

INTRODUCTION

Estrogen receptor beta (ERβ) overexpression by malignant pleural mesothelioma (MPM) tumor cells correlates with enhanced patient survival. ER-regulated transcription is mediated by the p160 family of steroid receptor coactivators (SRCs), and SRC isoform overexpression is associated with worse prognosis in many steroid-related malignancies. The aim of this study was to establish whether SRC isoform expression varied between individual MPM tumors with positive or negative prognostic significance.

METHODS

Immunohistochemical analysis of tumor biopsies from 89 subjects with confirmed histological diagnosis of MPM and biopsies from 3 normal control subjects was performed to detect the expression of SRC-1, SRC-2 (TIF-2), SRC-3 (AIB-1), and ERβ. Allred scores for expression of ERβ and each of the SRCs were determined, and Kaplan-Meier survival curves were calculated to correlate biomarker expression, gender, and histology type with postdiagnosis survival.

RESULTS

ERβ and all the SRCs were expressed at high levels in normal pleural mesothelium, and expression of each biomarker was reduced or lost in a subset of the MPM subjects; however, postdiagnosis survival only significantly correlated with TIF-2 expression. Low or intermediate expression of TIF-2 correlated with reduced median postdiagnosis survival (9 months) compared with those subjects whose tumors highly expressed TIF-2 (20 months) (p = 0.036, log-rank test).

CONCLUSIONS

Maintained high expression of TIF-2 in tumor cells is a positive prognostic indicator for postdiagnosis survival in patients with confirmed MPM. This is the first clinical study to correlate high TIF-2 expression with improved patient prognosis in any malignancy.

Potential of an in vitro toolbox combined with exposure data as a first step for the risk assessment of dietary chemical contaminants

In vitro risk assessment of dietary contaminants has become a priority in human food safety. This paper proposes an in vitro approach associating different complementary tools in an original toolbox and aims to improve the assessment of the toxicological impact of dietary contaminants at realistic human exposure levels, with a special focus on the intestinal compartment. The system is based on the use of four complementary cellular tools, namely stress gene induction in transgenic strains of Escherichia coli, modulation of the activity of key biotransformation enzymes (cytochrome P-450 (CYP) 1A1 and 3A4) in a human intestinal cell line, and activation of aryl hydrocarbon receptor (AhR) and oestrogenic receptor (ER)-dependent genes in agonistic and antagonistic assays with luciferase reporter cells. It was applied to four chosen model molecules: ochratoxin A (OTA) and deoxynivalenol (DON), two common food-borne mycotoxins, and imazalil (IMA) and benomyl (BEN), two fungicides widely occurring in foodstuffs. All these assays were performed at or around a realistic intestinal concentration, determined through a deterministic approach based on the calculation of a theoretical maximum daily intake (TMDI). Using the four model molecules, it is clearly highlighted that induction of CYP1A1 activity and inhibition of CYP3A4 activity occurred in Caco-2 cells at a realistic intestinal concentration of IMA. Furthermore, some bacterial stress genes were induced in a range of realistic concentrations, following exposure to DON and IMA. In addition, BEN clearly provoked an ER agonistic activity in a human oestrogen sensitive reporter cell line. All these results are in accordance with the literature, suggesting that the in vitro toolbox constitutes an interesting approach in order to obtain a first 'fingerprint' of dietary contaminants at realistic human exposure for further risk assessment.

Estrogen receptor alpha/beta, AIB1, and TIF2 in colorectal carcinogenesis: do coregulators have prognostic significance?

PURPOSE

Estrogen receptor beta (ER beta) is abundantly expressed in colorectal tissue, but its role in colorectal carcinogenesis remains elusive. Estrogen receptor coregulators, amplified in breast cancer 1 (AIB1) and transcription intermediary factor 2 (TIF2), have been well-characterized, but their expression in colorectal carcinomas has not been investigated.

MATERIALS AND METHODS

Estrogen receptor alpha (ER alpha), ER beta, AIB1, and TIF2 protein expression were evaluated by immunohistochemistry in colorectal normal mucosa, adenomas, and adenocarcinomas from 110 patients with colorectal cancer.

RESULTS

ER alpha expression was rare in colorectal tissue and its expression does not appear to be associated with colorectal carcinogenesis. ER beta, AIB1, and TIF2 were detected in the nucleus of epithelial, endothelial, inflammatory, smooth muscle cells, and myofibroblasts. The expression of the three proteins was significantly increased in epithelial cells of carcinomas compared to normal mucosa. In carcinomas, a significant correlation between the levels of expression of AIB1 and TIF2 was noted. Although AIB1 overexpression was associated with local tumor invasion, it was also found to correlate independently with prolonged overall survival.

CONCLUSIONS

ER beta, AIB1, and TIF2 appear to be involved in colorectal tumorigenesis and might have prognostic significance.

pS2 (TFF1) expression in prostate carcinoma: correlation with steroid receptor status

pS2 or TFF1 is a member of the trefoil factor family, which is distributed throughout the gastrointestinal tract in both normal and diseased tissues. It is also considered to be one of the major estrogen-regulated proteins and an indicator of estrogen receptor (ER) functionality. pS2 has previously been investigated in benign and malignant prostate lesions with little information about its relationship to steroid receptor status. Our purpose was to correlate pS2 expression with steroid receptor status (ER alpha and progesterone receptor (PR)) and other pathologic variables in prostate carcinoma. 15 benign prostate hyperplasia (BPH) and 47 prostate carcinoma cases were investigated by means of immunohistochemistry for pS2, ER and PR expression. 80% of BPH showed pS2 cytoplasmic immunoreactivity in hyperplastic acini and about half of these cases also exhibited nuclear staining decorating basal or both basal and luminal nuclei. pS2 was highly expressed in prostate carcinoma (91.4%) with both cytoplasmic and nuclear patterns of staining. The latter pattern was significantly associated with carcinoma having a low Gleason score (p=0.02). pS2 lacked any significant correlation with steroid receptor status, stage or grade. Univariate survival analysis revealed a significant impact of stage (p=0.03) and nodal status (p<0.0001) on patient outcome. The diagnostic value of pS2 expression in prostate carcinoma validated 74.19% accuracy, 91.48% sensitivity and 78.18% positive predictive value. The high sensitivity of pS2 expression in prostate carcinoma could make it a suitable marker for diagnosis of prostate carcinoma, especially in metastatic cases of unknown origin. The absence of correlation and dissimilarity in immunolocalization between pS2 and ER alpha leads to the assumption that ER alpha could not be the regulatory protein for pS2 and may raise questions about the functionality of ER alpha in prostate. The nuclear pattern of pS2 immunoreactivity either in benign or malignant prostatic lesions is similar to the published data on ER beta distribution and could also identify a subset of carcinoma patients with a favorable prognosis.

A comparison of the effects of soya isoflavonoids and fish oil on cell proliferation, apoptosis and the expression of oestrogen receptors alpha and beta in the mammary gland and colon of the rat

Isoflavonoids and fish oil may be protective against colorectal cancer, but the evidence in relation to breast cancer risk is ambiguous. In the present study, we have investigated the impact of soya-derived isoflavonoids and n-3 fatty acids from fish oil, both individually and in combination, on apoptosis, cell proliferation and oestrogen receptor (ER) expression in the colon and mammary gland of the rat. Female rats were fed diets high in n-3 fatty acids (80 g/kg diet) or soya protein (765 mg/kg diet isoflavones) for 2 weeks, and then killed before the removal of the colon and mammary glands. Cell proliferation and apoptosis were quantified morphologically in whole crypts and terminal end buds. The expressions of ERalpha and ERbeta were measured in colon tissue scrapes and the mammary gland. Fish oil significantly increased apoptosis and decreased mitosis in both tissues, an effect associated with a decrease in the expressions of ERalpha and ERbeta. Soya had no effect on apoptosis in either tissue, but reduced mitosis in the colon (P < 0.001) while increasing it in the mammary gland (P = 0.001). The changes in proliferation were associated with contrasting changes in the ER expression such that fish oil significantly decreased both ERbeta and ERalpha, while soya increased ERalpha and decreased ERbeta. The results may provide a novel mechanism by which n-3 fatty acids could reduce cancer risk, but the interpretation of the results in relation to soya consumption and breast cancer risk requires further investigation.

Map of differential transcript expression in the normal human large intestine

While there is considerable research related to using differential gene expression to predict disease phenotype classification, e.g., neoplastic tissue from nonneoplastic controls, there is little understanding of the range of expression in normal tissues. Understanding patterns of gene expression in nonneoplastic tissue, including regional anatomic expression changes within an organ, is vital to understanding gene expression changes in diseased tissue. To explore the gene expression change along the proximal-distal axis of the large intestine, we analyzed microarray data in 184 normal human specimens using univariate and multivariate techniques. We found 219 probe sets that were differentially expressed between the proximal and distal colorectal regions and 115 probe sets that were differentially expressed between the terminal segments, i.e., the cecum and rectum. We did not observe any probe sets that were statistically different between any two contiguous colorectal segments. The dominant expression pattern (65 probe sets) follows a dichotomous expression pattern consistent with the midgut-hindgut embryonic origins of the gut while a second pattern (50 probe sets) depicts a gradual change in transcript levels from the cecum to the rectum. While the dichotomous pattern includes roughly equal numbers of probe sets that are elevated proximally and distally, nearly all probe sets that show a gradual change demonstrate increasing expression levels moving from proximal to distal segments. These patterns describe an expression map of individual transcript variation as well as multigene expression patterns along the large intestine. This is the first gene expression map of an entire human organ.

Hormone replacement therapy, reproductive history, and colorectal adenomas: data from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial (United States)

OBJECTIVE

Findings from some epidemiologic studies of colorectal cancer and adenoma suggest that the protective effect of post-menopausal hormone replacement therapy (HRT) may differ across categories of age and body mass index (BMI). We conducted an analysis of women participating in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial to investigate the relationship between HRT use and prevalent adenoma, both overall and across different population subgroups.

METHODS

Women aged 55-74 were randomized to screening by flexible sigmoidoscopy at ten PLCO screening centers between September 1993 and September 2001. We identified 1468 women with at least one left-sided adenoma and 19,203 without adenoma or colorectal cancer. Information about HRT and reproductive factors was obtained from a self-administered questionnaire.

RESULTS

Compared to never use of HRT, current use was associated with a decreased prevalence of left-sided adenoma (odds ratio (OR) 0.85; 95% confidence interval (CI) 0.75-0.97). We found no evidence of dose-response with increasing duration of use for current or former users. The association with current HRT use was stronger among women aged 65+ (OR 0.69; 95% CI 0.56-0.84), with a BMI<30 (OR 0.82; 95% CI 0.71-0.95) and who regularly use aspirin or ibuprofen (OR 0.77; 95% CI 0.65-0.91). Other reproductive factors were not significantly associated with adenoma prevalence.

CONCLUSIONS

Our findings suggest that current HRT use may protect against colorectal adenoma, and that this protective effect is short-lived following cessation of use.

ERbeta isoform expression in colorectal carcinoma: an in vivo and in vitro study of clinicopathological and molecular correlates

Colorectal carcinoma shows several sex-related differences with regard to incidence, response to chemotherapy and microsatellite instability. These differences may relate to differential expression of ERbeta1 (wild-type) as well as the truncated ERbeta2 and ERbeta5 splice variant isoforms, which have recently been detected in normal and malignant colorectal epithelium. This hypothesis was tested through the study of ERbeta isoform protein and/or mRNA expression amongst 91 primary colorectal carcinoma cases and 20 colorectal carcinoma cell lines. Study of the latter showed an absolute correlation between mRNA and protein expressions for ERbeta1 and ERbeta2. ERbeta1 and ERbeta2 protein expression was lost in 22% and 49%, respectively, of the primary colorectal carcinomas. By contrast, ERbeta5 expression was found in all primary colorectal carcinomas and all colorectal carcinoma cell lines studied. Lower ERbeta1 protein expression was associated with poorer differentiation, higher pT stage and absence of microsatellite instability. Higher ERbeta2 protein expression was associated with right-sided location and presence of lymph node metastases. Protein expression of ERbeta1 correlated positively with expression of the oestrogen-responsive protein trefoil factor 1 (TFF1). There was no correlation between ERbeta protein isoform expression and response to 5-fluorouracil therapy, tumour proliferation, or thymidylate synthase expression. These data suggest that ERbeta1 and/or ERbeta2 isoform expression may have prognostic value and may explain sex-related differences in microsatellite instability and colorectal carcinoma. The opposing associations shown by ERbeta1 and/or ERbeta2 in relation to colorectal carcinoma are in keeping with differential activities shown by the two isoforms.

Identification and localization of estrogen receptor alpha- and beta-positive cells in adult male and female mouse intestine at various estrogen levels

Although estrogen is implicated in the regulation of mammalian intestinal function, the presence and the distribution of estrogen receptor (ER)-positive cells in the intestine are still controversial. The present study was designed to localize ERalpha- and ERbeta-expressing cells in female and male mouse intestines immunohistochemically under various estrogen conditions, especially in female mice, ovariectomized as well at various phases of the estrous cycle. Western blot analysis detected both ERalpha (66-kDa band) and ERbeta (56-kDa band). Immunohistochemical staining of paraffin-embedded sections after antigen-retrieval treatment with autoclaving revealed staining for ERalpha in submucosal interstitial cells, and double staining identified these cells as a subtype of intestinal macrophages. The number of these cells varied according to the estrous cycle phase. Administration of 17beta-estradiol to ovariectomized mice resulted in a significant increase in the number of ERalpha-positive macrophages. On the other hand, the nuclei of nerve cells in Auerbach and Meissner plexuses were positive for both ERalpha and ERbeta, but the number of positive nerve cells was not affected by estrogen. Our results indicate that estrogen and estrogenic compounds may exert their actions on the intestine in two ways; one is through interstitial macrophages and the other is through intestinal neurons.

GATA-4 and GATA-5 transcription factor genes and potential downstream antitumor target genes are epigenetically silenced in colorectal and gastric cancer

The GATA family of transcription factors participates in gastrointestinal (GI) development. Increases in GATA-4 and -5 expression occur in differentiation and GATA-6 expression in proliferation in embryonic and adult settings. We now show that in colorectal cancer (CRC) and gastric cancer promoter hypermethylation and transcriptional silencing are frequent for GATA-4 and -5 but are never seen for GATA-6. Potential antitumor target genes upregulated by GATA-4 and -5, the trefoil factors, inhibinalpha, and disabled-2 (Dab2) are also silenced, in GI cancers, with associated methylation of the promoters. Drug or genetically induced demethylation simultaneously leads to expression, in CRC cells, of all of the GATA-4, -5, and downstream genes. Expression of exogenous GATA-5 overrides methylation at the downstream promoters to activate the target genes. Selection for silencing of both upstream transcription factors and their target genes in GI cancers could indicate that epigenetic silencing of the involved genes provides a summated contribution to tumor progression.

Hormone replacement therapy and colorectal adenoma recurrence among women in the Polyp Prevention Trial

BACKGROUND

Epidemiologic studies have suggested that estrogen may protect against the development of colorectal cancers and adenomatous polyps. We conducted a prospective study to evaluate the association between hormone replacement therapy (HRT) and adenoma recurrence among perimenopausal and postmenopausal women participating in the Polyp Prevention Trial, a randomized dietary intervention study of individuals with colorectal adenomas.

METHODS

We used a questionnaire and interviews to collect detailed information, at baseline and at each of four annual study visits, from 620 women regarding hormone use, menopausal status, diet, alcohol consumption, and other risk factors. Adenoma recurrence was ascertained by complete colonoscopy at baseline and after 1 and 4 years. Logistic regression models were used to evaluate the association between hormone use and adenoma recurrence after adjusting for intervention group and for age and body mass index at baseline. All statistical tests were two-sided.

RESULTS

Adenomas recurred in 200 women. There was no overall association between adenoma recurrence and either overall hormone use (odds ratio [OR] = 1.01; 95% confidence interval [CI] = 0.70 to 1.45), combined estrogen and progestin use (OR = 0.94; 95% CI = 0.57 to 1.56), or unopposed estrogen use (OR = 1.04; 95% CI = 0.68 to 1.59). HRT use was associated with a reduction in risk for recurrence of distal adenomas (OR = 0.56; 95% CI = 0.32 to 1.00) and a statistically nonsignificant increase in risk for recurrence of proximal adenomas (OR = 1.39; 95% CI = 0.85 to 2.26). We observed a statistically significant interaction between the HRT-adenoma recurrence association and age (P =.02). HRT was associated with a 40% reduced risk of adenoma recurrence among women older than 62 years (OR = 0.58; 95% CI = 0.35 to 0.97) but with an increased risk among women younger than 62 years (OR = 1.99; 95% CI = 1.11 to 3.55).

CONCLUSIONS

HRT was not associated with a reduced risk for overall adenoma recurrence in this trial cohort, although there was a suggestion of an age interaction. The effect of age on the association needs to be confirmed in other adenoma recurrence trials.

Estrogen metabolism and malignancy: analysis of the expression and function of 17beta-hydroxysteroid dehydrogenases in colonic cancer

Age and sex differences in the incidence of gastrointestinal cancers suggest the involvement of sex steroids. Post-menopausal loss of estrogen in women appears to be associated with a lower risk of colonic cancer, and studies in vitro have shown that estradiol (E2) stimulates the growth of colonic cancer cell lines. Paradoxically more recent epidemiological data have shown that hormone replacement therapy (HRT) is associated with a lower risk of colonic cancer, although this may reflect differences in the composition and route of administration of HRT regimes. The precise mechanism by which estrogens influence colonic cancer in vivo remains unclear, although E2-induced growth of colonic cancer cells in vitro appears to be dependent on estrogen receptor (ER) expression. We have previously demonstrated differential responses to E2 in pre-malignant and malignant colonic cancer cell lines, without any apparent difference in ER expression. Analogous to well documented studies in breast cancer, we have postulated that local steroid metabolism in the colon may play a key role in modulating the effects of oestrogens by determining the tissue availability of active E2. Using biopsy material we have shown that the normal colonic mucosa has a high level of 17beta-hydroxysteroid dehydrogenase (17beta-HSD)-mediated E2 metabolism. Furthermore, the predominant enzyme activity, inactivation of E2 to estrone (E1), was significantly decreased in paired tumor biopsies. The presence of 17beta-HSD activity in the colon appears to be due to expression of the type 2 and 4 isozymes of 17beta-HSD (17beta-HSD2 and 4), and expression of mRNA for the latter was shown to be significantly decreased in tumours compared to normal mucosa. Further studies have characterised the expression of 17beta-HSD2 and 4 in colonic epithelial cells and in colonic cancer cell lines, and have suggested a link between estrogen metabolism and colonic cell proliferation. Data reviewed here provide evidence for the importance of 17beta-HSD isozymes as attenuators of E2 bioavailability in the colon, and emphasise a possible role for 17beta-HSD2 and 4 in the pathogenesis of colon cancer.

Oestrogen inactivation in the colon: analysis of the expression and regulation of 17beta-hydroxysteroid dehydrogenase isozymes in normal colon and colonic cancer

Epidemiological data suggest that oestrogen contributes to the aetiology of colonic cancer. Furthermore, recent studies have suggested that local hormone metabolism may play a key role in determining colonic responsiveness to oestrogen. To further clarify this mechanism we have characterized the expression and regulation of isozymes of 17beta-hydroxysteroid dehydrogenase (17beta-HSD) in vitro and in situ. Immunohistochemistry was used to confirm expression of the type 2 and 4 isozymes of 17beta-HSD (17beta-HSD2 and 4) in normal colonic epithelial cells. Parallel studies suggested that both isozymes were abnormally expressed in colonic tumours and this was confirmed by Western blot analyses. Abnormal expression of 17beta-HSD2 and 4 proteins was also observed in Caco-2, HT-29 and SW620 colonic cancer cell lines, although the overall pattern of oestrogen metabolism in these cells was similar to that seen in primary colonic mucosal tissue. The predominant activity (conversion of oestradiol to oestrone) was highest in Caco-2>SW620>HT-29, which correlated inversely with the rate of proliferation of the cell lines. Regulatory studies using SW620 cells indicated that the most potent stimulator of oestradiol to oestrone inactivation was the antiproliferative agent 1,25-dihydroxyvitamin D3 (1,25D3), whilst oestradiol itself inhibited 17beta-HSD activity. Both oestradiol and 1,25D3 decreased mRNA for 17beta-HSD2 and 4. Data indicate that the high capacity for inactivation of oestrogens in the colon is associated with the presence of 17beta-HSD2 and 4 in epithelial cells. Abnormal expression of both isozymes in colonic cancer cells and the stimulation of oestrogen inactivation by the antiproliferative agent 1,25D3 highlights a possible role for 17beta-HSD isozymes as modulators of colonic cell proliferation.

Changes in expression of estrogen receptors alpha and beta in relation to progesterone receptor and pS2 status in normal and malignant endometrium

To clarify changes in estrogen receptor (ER) alpha and ERbeta during endometrial tumorigenesis, 48 endometrial carcinomas (endometrioid type), as well as 40 samples of normal endometrial tissue, were investigated using a combination of reverse-transcription and polymerase chain reaction with Southern blot hybridization and western blot assays, and the results were compared with findings for progesterone receptor (PR) and pS2 mRNA status. In addition, 166 carcinomas were also examined for immunohistochemistry, along with 171 normal specimens. Relative amounts of ERalpha at both mRNA and protein levels were significantly greater than those for ERbeta in normal and malignant endometrial lesions. ERalpha mRNA showed a stepwise decrease from normal or grade (G) 1 through to G3 tumor lesions, in line with changes in the protein levels, in contrast to ERbeta mRNA or protein expression, which did not alter, suggesting a shift in the ratio of the two ER subtypes during endometrial tumorigenesis. PR mRNA expression was significantly correlated with ERalpha, but not ERbeta mRNA status. Although significantly higher expression of pS2 mRNA or protein was observed in carcinomas than in the normal cases, there was no apparent association with the ER status. The findings suggest that alteration in estrogen signaling pathways may occur during endometrial tumorigenesis, and provide evidence that ERalpha expression may play an important role in the regulation of PR, but not pS2 expression in normal and malignant endometrium.

Estrogen receptor beta mRNA in colon cancer cells: growth effects of estrogen and genistein

Knowledge regarding the expression of the recently cloned estrogen receptor beta (ERbeta) in colonic mucosa is limited. In this study, we demonstrated that five human colon cancer cell lines, HT29, Colo320, Lovo, SW480, and HCT116, expressed ERbeta mRNA, but lacked ERalpha mRNA. Results from a cell growth assay demonstrated that these colon cancer cells were not influenced by estrogen, while genistein possessed slight growth inhibitory effects on HT29, Colo320 and Lovo cells at 10 microM, at which concentration is stimulated the growth of ERalpha-positive human breast cancer MCF-7 cells. Tamoxifen inhibited the growth of HT29 and Colo320 cells, dose-dependently, as well as MCF-7 cells. A transfected reporter plasmid containing a vitellogenin estrogen response element could be activated by estradiol in Colo320 cells. Taken together with previous reports, these data suggest that ERalpha and ERbeta may have different biological functions in colon cells.

Up-regulation of pS2 expression during the development of adenocarcinomas but not squamous cell carcinomas of the uterine cervix, independently of expression of c-jun or oestrogen and progesterone receptors

The pS2 gene product was firstly identified as an oestrogen-induced molecule in a breast cancer cell line, while recent studies demonstrate a close association with mucus-secreting epithelia. To assess pS2 expression in uterine cervical adenocarcinomas (C-ACas) and invasive squamous cell carcinomas (C-ISCCs), a series of 94 and 86 cases, respectively, as well as 77 samples of normal cervix, were immunohistochemically investigated and the results compared with data for expression of oestrogen and progesterone receptors (ER and PR) and c-jun. RT-PCR and western blot assays were also applied to 21 cervical carcinomas and 24 normal tissues. With cervical glandular lesions, significant up-regulation of pS2 expression at both the mRNA and the protein levels was observed for adenocarcinomas in situ (AISs) and overt carcinomas, closely linked with mucinous differentiation and tumour grades. pS2 scores were inversely related to ERalpha status for all cervical glandular categories, while there was no association with ERbeta and PR values. In squamous lesions, pS2 values did not differ between normal and malignant lesions, in contrast to the significant down-regulation of ERalpha expression with tumour development. Although c-jun expression significantly correlated with ERalpha values for all squamous categories, it did not relate to pS2 status in either C-ACas or ISCCs. These results indicate that alterations in pS2 expression may occur relatively early in the development of cervical glandular, but not squamous lesions, independently of factors known to promote transcription of the pS2 gene.

Patterns of expression of trefoil peptides and mucins in gastric polyps with and without malignant transformation

The expression of two trefoil peptides (TFF1 and TFF2) and four mucins (MUC1, MUC2, MUC5AC, and MUC6) was evaluated by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) in 29 gastric polyps, 10 hyperplastic and 19 adenomatous, eight of which displayed malignant transformation. The aims of this study were to characterize the expression profile of these molecules in each type of polyp and to investigate possible modifications of the profile during the process of malignant transformation. All hyperplastic polyps displayed immunoreactivity for TFF1, MUC5AC, and MUC1 in more than 75 per cent of the cells. In adenomatous polyps, three main phenotypes could be identified: complete gastric phenotype (co-expression of TFF1 and MUC5AC)-nine cases (47.4 per cent); incomplete gastric phenotype (TFF1-positive and MUC5AC-negative)-seven cases (36.8 per cent); non-gastric (intestinal) phenotype (no expression of TFF1 or MUC5AC)-three cases (15.8 per cent). Data yielded by immunohistochemistry and RT-PCR showed a good correlation for both TFF1 and TFF2. One hyperplastic and seven adenomatous polyps with villous architecture displayed foci of diffuse and intestinal-type carcinoma, respectively; in all of these cases, MUC1 expression and signs of gastric differentiation were observed in both the non-malignant and the carcinomatous component. It is concluded that gastric differentiation is a feature of hyperplastic polyps and of a subset of adenomatous polyps which is shared by early carcinomas arising in some of these polyps, regardless of the histological type of polyp and of carcinoma.

DNA hypermethylation at the pS2 promoter region is associated with early stage of stomach carcinogenesis

pS2, a member of the trefoil peptide family, has been suggested to be a gastric-specific tumor suppressor. We examined the expression of pS2 in gastric carcinomas, adenomas and non-neoplastic mucosa and analyzed the DNA methylation in the pS2 promoter. Reduced expression of pS2 was frequently associated with well-differentiated adenocarcinomas. The CpG sites within the promoter region of the pS2 gene were methylated in pS2-negative gastric carcinoma cell lines whereas it was not in pS2-positive cell line. The promoter methylation was detected in gastric carcinoma tissues and intestinal metaplasia with reduced pS2 expression whereas none of the carcinomas with preserved pS2 expression showed the promoter methylation. These findings suggest that reduced expression of pS2 due to the promoter methylation may participate in an early stage of stomach carcinogenesis, especially of well differentiated type.

Expression of receptors for estrogen and progesterone in malignant colonic mucosa as a prognostic factor for patient survival

BACKGROUND AND OBJECTIVES

Estrogen receptors (ER) and progesterone receptors (PR) have been detected in both normal and malignant colonic mucosa, but the prognostic value of this observation is unknown. We aimed to define the prognostic significance of the presence of ER and PR in malignant cells from colorectal adenocarcinoma specimens.

METHODS

An immunohistochemical assay for ER and PR was performed on paraffinized sections from 65 colorectal adenocarcinoma specimens. Survival curves were analyzed to define the prognostic implications of ER and PR.

RESULTS

Twenty nine (45%) tumors tested receptor positive (32% for ER and 23% for PR). Tumors of advanced stage were more likely to express receptors than early stage tumors (56% vs. 32%; P = 0.01). Median survival of patients with neoplasms expressing PR was 30 months. For patients whose tumors did not express any receptors, median survival had not been reached at the time of follow-up (P = 0.04). Similarly, patients with tumors expressing both receptors had significantly reduced survival (median survival = 20 months; P = 0.003).

CONCLUSIONS

Expression of receptors for sex steroids correlates with advanced stage disease. Expression of PR by the tumor cells is associated with a shorter patient survival. The results suggest that sex steroids may play a role in carcinogenesis and tumor progression.

Trefoil peptides and surgical disease

BACKGROUND

Trefoil peptides are a family of small proteins that are expressed in a site-specific fashion by certain epithelial tissues. These peptides appear to be important in mucosal healing processes and in neoplastic disease.

METHODS

This manuscript reviews the relevant literature obtained by an extensive text word search of the Medline database and a manual search of references from the articles identified.

RESULTS AND CONCLUSION

Trefoil peptides are aberrantly expressed by a wide range of human carcinomas and gastrointestinal inflammatory conditions. They impart protection from injury to the gastrointestinal mucosa by possible interaction with mucin glycoproteins. Trefoil peptides influence epithelial cell migration and mucosal restitution following injury. In the future, serum levels of trefoil peptides might be used as markers for both neoplastic and inflammatory diseases. In addition, novel therapies based on such peptides might be used for gastrointestinal inflammatory conditions and to accelerate repair of the gastrointestinal mucosa after surgery.

Patterns of expression of trefoil peptides and mucins in gastric polyps with and without malignant transformation

The expression of two trefoil peptides (TFF1 and TFF2) and four mucins (MUC1, MUC2, MUC5AC, and MUC6) was evaluated by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) in 29 gastric polyps, 10 hyperplastic and 19 adenomatous, eight of which displayed malignant transformation. The aims of this study were to characterize the expression profile of these molecules in each type of polyp and to investigate possible modifications of the profile during the process of malignant transformation. All hyperplastic polyps displayed immunoreactivity for TFF1, MUC5AC, and MUC1 in more than 75 per cent of the cells. In adenomatous polyps, three main phenotypes could be identified: complete gastric phenotype (co-expression of TFF1 and MUC5AC)-nine cases (47.4 per cent); incomplete gastric phenotype (TFF1-positive and MUC5AC-negative)-seven cases (36.8 per cent); non-gastric (intestinal) phenotype (no expression of TFF1 or MUC5AC)-three cases (15.8 per cent). Data yielded by immunohistochemistry and RT-PCR showed a good correlation for both TFF1 and TFF2. One hyperplastic and seven adenomatous polyps with villous architecture displayed foci of diffuse and intestinal-type carcinoma, respectively; in all of these cases, MUC1 expression and signs of gastric differentiation were observed in both the non-malignant and the carcinomatous component. It is concluded that gastric differentiation is a feature of hyperplastic polyps and of a subset of adenomatous polyps which is shared by early carcinomas arising in some of these polyps, regardless of the histological type of polyp and of carcinoma.