Expression of estrogen receptors during growth of human pancreatic adenocarcinoma cells (Capan-1)-relationship with differentiation

Sex Differences in the Exocrine Pancreas and Associated Diseases

Differences in pancreatic anatomy, size, and function exist in men and women. The anatomical differences could contribute to the increase in complications associated with pancreatic surgery in women. Although diagnostic criteria for pancreatitis are the same in men and women, major sex differences in etiology are reported. Alcohol and tobacco predominate in men, whereas idiopathic and obstructive etiologies predominate in women. Circulating levels of estrogens, progesterone, and androgens contribute significantly to overall health outcomes; premenopausal women have lower prevalence of cardiovascular and pancreatic diseases suggesting protective effects of estrogens, whereas androgens promote growth of normal and cancerous cells. Sex chromosomes and gonadal and nongonadal hormones together determine an individual's sex, which is distinct from gender or gender identity. Human pancreatic disease etiology, outcomes, and sex-specific mechanisms are largely unknown. In rodents of both sexes, glucocorticoids and estrogens from the adrenal glands influence pancreatic secretion and acinar cell zymogen granule numbers. Lack of corticotropin-releasing factor receptor 2 function, a G protein-coupled receptor whose expression is regulated by both estrogens and glucocorticoids, causes sex-specific changes in pancreatic histopathology, zymogen granule numbers, and endoplasmic reticulum ultrastructure changes in acute pancreatitis model. Here, we review existing literature on sex differences in the normal exocrine pancreas and mechanisms that operate at homeostasis and diseased states in both sexes. Finally, we review pregnancy-related pancreatic diseases and discuss the effects of sex differences on proposed treatments in pancreatic disease.

Association of Sex Hormones with Risk of Cancers of the Pancreas, Kidney, and Brain in the UK Biobank Cohort Study

BACKGROUND

There is some evidence to suggest that endogenous levels of sex hormones might influence the etiology of cancers of the pancreas, kidney, and brain, but epidemiologic data are lacking.

METHODS

We evaluated the association of circulating levels of total and free testosterone, and of sex hormone-binding globulin (SHBG), with the risk of cancers of the pancreas, kidney, and brain, and of total and free estradiol with the risk of kidney cancer, in the UK Biobank cohort study (n = 425,793; 225 pancreatic cancers, 749 kidney cancers, 467 brain cancers). Multivariable Cox proportional hazards models were used to estimate HRs and 95% confidence intervals for the associations.

RESULTS

Testosterone and SHBG levels were not associated with risk of pancreatic cancer. Most of the associations for the other two anatomic sites were null. There were inverse associations between total testosterone and brain cancer in men and between SHBG and risk of kidney cancer in the total sample and in women. Estradiol was not associated with the risk of kidney cancer.

CONCLUSIONS

The results of this study provide little support for associations between sex hormones/SHBG and risk of cancers of the pancreas, kidney, and brain. Larger studies are warranted.

IMPACT

Although these results provide little support for roles for sex hormones and SHBG in the etiology of cancers of the pancreas, kidney, and brain, there is a need for studies with larger numbers of cases.

The flavonoid beverage Haelan 951 induces growth arrest and apoptosis in pancreatic carcinoma cell lines in vitro

BACKGROUND

A major challenge in pancreatic cancer treatment is the resistance of human pancreatic cancer cells to apoptosis. Soy isoflavones and calpain inhibition have been suggested to exert inhibitory effects on cancer development and progression. We investigated the effects of the isoflavone containing beverage Haelan 951 and the calpain inhibitor PD150606 on the viability, growth and apoptosis of the human pancreatic cancer cell lines CAPAN-1 and BxPC-3, on the rat pancreatic cancer cell line AR42J, and on human fibroblasts as the control cell line.

METHODS

Cellular viability and proliferation were determined using the LDH cytotoxicity and WST-1 assay, respectively. Apoptosis was detected by flow cytometric analyses of Annexin V-FITC labeled-cells, TUNEL assay and caspase activation. Student's t test or Mann-Whitney Rank Sum test were used to compare the data.

RESULTS

Haelan concentrations lower than 8% showed no cytotoxic effects, whereas higher concentrations led to necrosis. Eight percent Haelan induced significant growth inhibition of CAPAN-1 and BxPC-3 cell lines by 30% and 35%, respectively, compared with the control. The proliferation rate of AR42J cells decreased by 50%, whereas the fibroblasts remained unaffected. An 1.1-fold increase in apoptosis was found in CAPAN-1 cells, whereas the number of apoptotic BxPC-3 cells was elevated 2-fold. The number of apoptotic AR42J cells and fibroblasts was elevated 1.5-fold, each. Inhibition of calpain activity amplified the Haelan-induced growth inhibition of CAPAN-1 and BxPC-3 cells, but failed to amplify the growth inhibition of Haelan-treated AR42J cells. In fibroblasts, calpain inhibition induced Haelan-independent growth inhibition. Calpain inhibition also amplified the Haelan-induced apoptotic activity in all cancer cell lines, but exerted no further effect in fibroblasts.

CONCLUSIONS

The proliferation-inhibiting and apoptosis-inducing effects of Haelan are highly dependent on cell type and concentration administered. The results show for the first time that Haelan may be a promising candidate in the treatment of human pancreatic cancer, and its anticancer activity may be potentiated when administered with calpain inhibitors.

Estrogen receptor beta/alpha ratio predicts response of pancreatic cancer cells to estrogens and phytoestrogens

BACKGROUND

Reports on hormone receptor expression of pancreatic cancer (PaCa) cells and treatment responses to antihormonal therapy are conflicting. We examined estrogen receptor (ER) expression in PaCa cells and investigated its function in estrogen-mediated cell proliferation.

METHODS

Protein levels of ERalpha and ERbeta in 8 human PaCa lines were detected by Western blot analysis. Cell proliferation was measured by sulforhodamine B analysis. ER modulators included diethylstilbestrol (DES), estradiol (E2), 4-hydroxytamoxifen (Tam), genistein (Gen), and Coumestrol (Coum).

RESULTS

ERalpha levels were detected in all eight, and ERbeta in seven cell lines. ERbeta/ERalpha ratio ranged from 0.4 to 111 (median: 6.4, >5 in seven lines). Median maximal growth stimulation (in %, observed at 20 to 200 nM) was 19 (DES), 39 (E2), 20 (Tam), 22 (Gen), and -9 (Coum); median maximal inhibition (at 40 to 60 microM) was 59 (DES), 36 (E2), 25 (Tam), 43 (Gen), and 50 (Coum). The extent of E2 and Gen stimulatory effects correlated with the ERbeta/ERalpha ratio (Kendall's tau: 0.714, P = 0.024), but not ERalpha or ERbeta levels alone. Only Coum-induced inhibition correlated with the ERbeta/ERalpha ratio (P = 0.006) and with ERalpha expression (r = 0.753, P = 0.03). Gemcitabine-induced PaCa cytotoxicity (at IC(40)) was significantly reduced by E2, Gen, and Coum.

CONCLUSIONS

PaCa proliferation in vitro is highly estrogen sensitive, and in contrast to other reports, ERs are frequently expressed. In 7/8 cell lines, ERbeta expression outweighs ERalpha expression. The impact of the ERbeta/ERalpha ratio on estrogen-mediated growth stimulation and reduced cytotoxicity at physiological concentrations may have clinical implications on PaCa therapy.

Down-Regulation of BRCA1 in Chronic Pancreatitis and Sporadic Pancreatic Adenocarcinoma

PURPOSE

BRCA1 and BRCA2 are considered to be breast cancer susceptibility genes that may also contribute to pancreatic cancer development because family studies revealed mutation carriers to have an increased risk of developing pancreatic cancer. However, as demonstrated for breast and ovarian cancer, inactivation of BRCA in sporadic diseases is based on alteration in gene expression or functional alteration.

EXPERIMENTAL DESIGN

To study a potential correlation of BRCA1 and BRCA2 to chronic pancreatitis and development of sporadic pancreatic adenocarcinoma, we have analyzed the expression of these genes by quantitative PCR and performed immunohistochemical analyses in normal pancreatic tissues, chronic pancreatitis, and pancreatic cancer specimens.

RESULTS

BRCA1 expression was down-regulated in chronic alcoholic pancreatitis, in particular on the RNA level. Furthermore, our data indicate suppressed BRCA1 expression in pancreatic cancer on both the RNA and protein levels. Quantitative analysis of BRCA1 protein expression demonstrated regular staining in 50% of tumor specimens tested and reduced staining in 50% of tumor specimens tested. Correlation with the clinical outcome revealed a significantly better 1-year overall survival for patients with BRCA1-regular as compared with BRCA1-reduced or BRCA1-absent tumors. In contrast, no substantial differences in BRCA2 expression were found in chronic pancreatitis and pancreatic cancer samples.

CONCLUSIONS

Our data demonstrate alteration of BRCA1 expression in chronic pancreatitis and sporadic pancreatic adenocarcinoma. We, for the first time, provide evidence for a role of BRCA1 in pancreatic carcinogenesis of noninherited tumors and for clinical outcome.

The beta form of the estrogen receptor is predominantly expressed in the papillary cystic neoplasm of the pancreas

INTRODUCTION

Papillary cystic neoplasm (PCN) of the pancreas is a low-malignancy tumor affecting predominantly young females. Sex steroid hormones have been involved in its development and/or growth. Estrogen receptor (ER) has been scarcely found in this tumor, although there is some evidence suggesting expression of the beta-isoform. Unlike ER, progesterone receptor (PR) expression has been consistently observed. Immunohistochemical analysis of the two isoforms of ER has not been performed in this tumor.

AIM

To characterize expression of ER isoforms with an immunohistochemical method.

METHODOLOGY

Expression of ER-alpha, ER-beta, and PR was analyzed by immunohistochemistry using isoform-specific ER and PR antibodies in paraffin-embedded tissue blocks from seven cases of PCN of the pancreas.

RESULTS

Most patients were young females. ER-alpha and ER-beta were present in two and six tumors, respectively. PR was identified in six tumors.

CONCLUSIONS

ER-beta expression predominates over the alpha-isoform in PCN of the pancreas. This finding supports the idea that previous negative results on ER expression were a consequence of the use of antibodies with no anti-beta activity. The role of ER-beta in the milieu of factors promoting the development and aggressiveness of PCN needs to be elucidated to address novel diagnostic and therapeutic approaches.