Type II estrogen receptors in the papillary cystic tumor of the pancreas

Natural history and malignant risk factors of solid pseudopapillary tumors of the pancreas

BACKGROUND AND AIM

Solid pseudopapillary tumors (SPTs) of the pancreas are unusual neoplasms of uncertain prognosis. Most patients with SPTs have a good prognosis after undergoing surgical resection, but there are rare cases in which a locally infiltrative growth pattern and metastatic variety are exhibited, or recurrence of the disease after surgery occurs; these cases have been reported with very poor clinical outcomes. Our study investigated the natural history of SPTs and delineated the clinicopathologic features that may predict the malignancy potential of the disease.

METHODS

A total of 100 patients with suspected SPTs were enrolled in our study and 77 patients underwent surgical resection. A resulting 60 tumors were pathologically proven to be SPTs and the affected patients were followed-up regularly after surgery. Clinical and pathologic data for all 100 patients were analyzed.

RESULTS

Of the 60 total patients with histologically positive SPTs, 55 (92%) were women and 5 (8%) were men. The median patient age was 34 years (range, 13-77 years). Among the 60 patients, 9 had malignant SPTs and 51 had benign SPTs. Deep parenchymal invasion into the surrounding tissue was the most frequent pathologic feature suggesting malignancy (75%) among the 60 patients who underwent surgical resection. Patient clinicopathologic characteristics and demographic factors were compared between those who had benign SPTs and those who had malignant SPTs. There were no significant differences in the various patient features between the 2 groups, including age, sex, symptoms, tumor size, tumor location, internal tumor composition, pattern of tumor calcification, tumor necrosis, hemorrhage, and immunohistochemical tumor tissue patterns. There were 2 patients who had distant metastasis; 1 presented with distal metastasis in the liver and the other patient had recurrence of cancer with a peritoneal mass after surgery. Metastasectomy was performed on the 2 patients and there was no mortality or disease progression during the follow-up period (median, 143 months; range, 53-319 months).

CONCLUSION

Solid pseudopapillary tumors are low-grade tumors that have a generally good prognosis. However, the clinical development and malignancy potential of SPTs are neither fully understood nor predictable, even with histologically benign tumors. Further investigations in tumor biology, along with long-term patient follow-up, may provide insight into the disease process and clinical development of SPTs.

Luteolin and gefitinib regulation of EGF signaling pathway and cell cycle pathway genes in PC-3 human prostate cancer cells

cRNA microarray and real-time PCR (qPCR) studies from our lab identified five Cell Cycle Pathway (CCP) genes (CCNA2, CCNE2, CDC25A, CDKN1B, and PLK-1) as targets for luteolin in PC-3 prostate cancer cells [Shoulars et al., J. Steroid Biochem. Mol. Biol. 118 (2010) 41-50]. In this paper, Ingenuity Pathway Analysis of the microarray data identified 7 luteolin-regulated genes (EGFR, c-Fos, SOS, GRB2, JNK1, MKK4 and RasGAP) in the Epidermal Growth Factor Signaling Pathway (EGFSP) potentially involved in luteolin regulation of CCP genes and cell proliferation. To address these possibilities, we compared the response profiles (RNA and protein) of these EGFSP and CCP genes to luteolin and gefitinib by real-time PCR (qPCR) and Western blot analyses. Luteolin and gefitinib are known antagonists of EGFR-associated tyrosine protein kinase. Thus, the response profiles of EGFR regulated EGFSP or CCP genes should be very similar if genes in both pathways are controlled through this common mechanism of action. Treatment of PC-3 cell with luteolin for 24h caused a 4-fold stimulation of c-Fos gene expression, significant inhibition (p<0.001) of the CCP genes and G2/M arrest. Treatment of PC-3 cells with gefitinib also inhibited most of the CCP genes in a fashion similar to that of luteolin, however, the EGFR antagonist inhibited c-Fos gene expression, stimulated CDKN1B (p27) and arrested the cells in G0/G1. Thus, although the response patterns of most of the CCP genes to luteolin or gefitinib were similar, the effects of the two compounds on EGFSP gene expression and cell cycle arrest were clearly different. Combination studies revealed that the response of EGFSP genes to luteolin was not affected by gefitinib, even though the two compounds were additive with respect to their abilities to inhibit CCNA2, CCNE2, CDC25A and PCNA. These findings suggest that luteolin and gefitinib regulate CCP gene expression through a common mechanism involving EGFR-associated tyrosine kinase. Conversely, luteolin regulates PC-3 cell proliferation through an EGFR-tyrosine kinase independent mechanism(s), likely involving the epigenetic control of gene EGFSP gene expression through histone H4 binding interactions resulting in the upregulation of c-Fos and p21 gene expression.

Regulation of cell cycle and RNA transcription genes identified by microarray analysis of PC-3 human prostate cancer cells treated with luteolin

Prostate cancer is the second leading cause of cancer-related deaths in men in the United States. Our previous studies have shown that ligands for the nuclear type II [(3)H]estradiol binding site such as luteolin significantly inhibit prostate cancer cells in vitro and in vivo; however, the role of these ligands in cell growth and proliferation is poorly understood. In order to further elucidate the molecular mechanism through which luteolin exerts its effects on PC-3 cells, cRNA microarray analyses was performed on 38,500 genes to determine the genes altered by luteolin treatment. The expression of 3331 genes was changed greater than 1.2-fold after luteolin treatment. Analysis of the altered genes identified two pathways that were significantly affected by luteolin. The Cell Cycle Pathway contained 22 down-regulated genes (including polo-like kinase 1, cyclin A2, cyclin E2 and proliferation cell nuclear antigen) and one up-regulated gene (cyclin-dependent kinase inhibitor 1B). In addition, 13 genes were down-regulated by luteolin in the RNA Transcription Pathway. Real-time polymerase chain reactions and western blots verified the observations from the microarray. In addition, two synthetic, chemically distinct type II ligands, ZN-2 and BMHPC, mimicked the effects of luteolin on gene expression at the mRNA and protein level in PC-3 cells. Finally, chromatin immunoprecipitation assays indicated that luteolin exerts its effects on genes by altering the acetylation state of promoter-associated histones. Taken together, the data suggest that type II ligands inhibit cell growth and proliferation through epigenetic control of key genes involved in cell cycle progression and RNA transcription.

Solid pseudopapillary neoplasms of the pancreas

SPN is a rare neoplasm that affects mainly young women. Despite this feature, SPN have been seen in both genders, multiple races, and at a wide range of ages. The genetic mechanism behind the development of SPN is distinct from the more lethal ductal carcinoma of the pancreas. This difference is reflected in the favorable outcome for patients with SPN. Surgery is typically curative in patents with localized disease and possibly in patients with limited metastasis or local extension. No consensus exists on an effective systemic therapy. There are no reliable predictors for disease-specific mortality or recurrence in the minority of patients who develop aggressive disease.

Solid-pseudopapillary neoplasm of the pancreas: Three cases with a literature review

Solid-pseudopapillary neoplasm of the pancreas is a very rare tumor. It most commonly occurs in young women and has unique pathologic features. Previous immunohistochemical studies demonstrated that most solid-pseudopapillary neoplasms were immunoreactive with antibodies directed against vimentin and neuron-specific enolase. Recently, expression of CD10 and CD56 in this tumor has been reported. In this report, we expanded the demographic profile, highlighting 3 cases of solid-pseudopapillary neoplasm of the pancreas that presented in an elderly woman, a young man, and a young woman and further characterized them histologically and immunophenotypically. Grossly, all 3 tumors were well circumscribed and had a variable degree of cystic formation, necrosis, and hemorrhage. Microscopically, these tumors were characterized by a pseudopapillary pattern of epithelioid cells arranged around a delicate fibrovascular core with sheets of bland epithelioid cells filling cystic spaces. Hyaline globules, cholesterol granulomas, and foamy cells were all seen to be common findings. Although these 3 tumors were strongly immunoreactive for vimentin, alpha-1-antitrypsin, alpha-1-antichymotrypsin, neuron-specific enolase, CD10, CD56, and progesterone receptor, they demonstrated only variable "positivity" for epithelial membrane antigen and broad-spectrum cytokeratin, but were being consistently nonreactive for synaptophysin, insulin, glucogon, chromogranin A, and estrogen receptor. Interestingly, 2 of the 3 tumors were S-100 protein and melanin A reactive but were nonreactive for HMB45.

Solid and Pseudopapillary Tumor of the Pancreas—Review and New Insights Into Pathogenesis

Solid pseudopapillary tumors (SPT) of the pancreas are rare neoplasms that occur mostly in young women. Despite of a low malignant potential, 10% to 15% of the cases have aggressive behavior with metastatic dissemination possibly leading to death. To date, no pathological factor can reliably predict the outcome of these tumours. Galectin-3, a major actor in the carcinogenesis of pancreatic ductal adenocarcinoma, has not been investigated in SPT. The presence of progesterone receptors is frequently reported in SPT, whereas that of estrogen receptor (ER) is unclear. We studied 5 cases of SPT consisting of 4 pancreatic tumors and 1 metastatic case. The morphological distinctive feature of metastatic nodules was the presence of polygonal or spindle cells with pleiomorphic nuclei and high mitotic count exhibiting a diffuse, infiltrative growth pattern. We found a strong expression of galectin-3 in all SPTs, whereas, interestingly, it was lower in metastatic nodules. Conversely, no galectin-3 expression was found in normal pancreatic endocrine cells or in neuroendocrine tumors. We suggest therefore that galectin-3 is a useful marker to distinguish SPT from neuroendocrine tumor, and also indicator of behavior because its low expression is associated with metastatic spreading. Moreover, the presence of galectin-3 in both SPT and pancreatic ducts rises the hypothesis of a posible ductal origin of these tumors. Specific antibodies for anti-ERalpha and anti-ERbeta demonstrated a strong expression of ERbeta whereas ERalpha was not detected. In conclusion, the present study brings the first evidence of the involvement of galectin-3 in SPT but also brought up clues which allowed to reconcile previously conflicting results on the presence of ER.

Estrogen receptors in pancreatic tumors

OBJECTIVES

Although a potential role for estrogen receptors (ER) in pancreatic tumors has been debated for many years, the importance of the receptors in these neoplasms remains unknown. Even the expression of the 2 ER isoforms, ER-alpha and ER-beta, in histological subtypes of pancreatic neoplasms is controversial. The aim of the present study was to systematically review the available literature about ER expression in pancreatic tumors and to discuss the potential importance of estrogen signaling in them.

METHODS

We performed a comprehensive literature search and analyzed the results regarding ER expression in pancreatic tumors, with special emphasis on the specificity of the antibodies used for immunohistochemistry.

RESULTS

Many articles have been published investigating the expression of ERs in pancreatic tumors, but the results are inconsistent. Moreover, most studies used antibodies that detected only ER-alpha, not ER-beta. Thus, the expression pattern of ER-beta in pancreatic neoplasm remains especially unclear.

CONCLUSIONS

The lack of detailed studies evaluating the expression of both ER-alpha and ER-beta receptors using isoform-specific antibodies likely contributes to the inconsistency of published results concerning ER expression in pancreatic tumors. Available published evidence suggests that a thorough reexamination of the potential role of ERs in pancreatic neoplasms is warranted.

Impact of menopausal status on the behavior of pancreatic cystic neoplasms in women

PURPOSE

Pancreatic cystic neoplasms have predilections for occurring in young women, for containing "ovarian-like" stroma, and for expressing estrogen and progesterone receptors; these factors suggest a potentially important influence of the hormonal milieu on the biology of these tumors. Therefore, we examined the impact of menopausal status on the clinical features of pancreatic cystic neoplasms in women.

METHODS

Seventy-six women with pancreatic cystic neoplasms treated at our institution from 1992 to 2003 were classified into 2 groups according to menopausal status based on the U.S. average menopausal age of 51 years: group I (premenopausal, ages 22-50; n = 36) and group II (postmenopausal, ages 51-80; n = 40). Chi-square and the 2-tailed t-tests compared categorical and continuous variables, respectively. Kaplan-Meier survival estimates were determined and compared with the log rank test.

RESULTS

Abdominal pain at presentation occurred more commonly among group I than among group II patients (78% vs 48%, p < 0.05). Solid pseudopapillary tumors were more prevalent among group I than among group II patients (21% vs 3%, p = 0.02).

CONCLUSIONS

The clinicopathologic features of pancreatic cystic neoplasms in premenopausal women are not significantly different from those in postmenopausal women. Menopausal status should not bias diagnostic and treatment algorithms for women with these neoplasms.

Therapeutic strategy of papillary cystic and solid neoplasm (PCSN): a rare non-endocrine tumor of the pancreas in children

Papillary-cystic and solid neoplasm (PCSN) are rare tumors. Two personal observations and a review of the literature are presented with a total of 44 pediatric patients in addition to a total of 67 published cases in the review of Cohen (Pediatr. Surg. Int. 6 (1991) 128) and Snadjauf (Eur. J. Pediatr. Surg. 9 (1999) 416). Overall, PCSN shows a clear predominance in females and only occasionally occurs in males. Typically they grow to a large tumor mass with minimal symptoms. Their histologic and immunocytologic characteristics cause diagnostic difficulties, especially on frozen sections of small biopsies. The tumors are assumed to origin from pluripotent stem cells and present as tumors of low malignancy with a favorable prognosis. Nevertheless 10 children have been reported to develop metastases, 5 have demonstrated an invasive growth pattern and 4 local recurrence. But only two of the 111 pediatric cases have died from their tumor burden. Treatment of choice is a complete surgical resection, which is true for the primary tumor and for metastases as well as local recurrences. In our 2 patients one had spleen-conserving left pancreatic resection and one mesopancreatectomy with roux-en-y-reconstruction leading to long-term cure. Adjuvant therapy in curative resected patients is unnecessary and does not appear to improve prognosis.

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.

Comparative study of non-functional islet cell tumors and pancreatic solid and papillary neoplasms: biological behavior and immunohistochemistry

Although non-functional islet cell tumor (NFICT) and solid and papillary neoplasm (SPN) share similar clinical and pathological features, the outcome of each is different. Because NFICT often follow a malignant course and SPN are usually benign, the correct differential diagnosis is very important. We investigated the clinical and pathological findings in 10 cases of NFICT and 12 cases of SPN, including immunohistochemical analysis for chromogranin, vimentin, neuron-specific enolase, somatostatin, alpha-1-antitrypsin, estrogen receptor, progesterone receptor, CD99, p21 and Ki-67. The current study shows that chromogranin is the most valuable marker in differentiating between the tumors (P < 0.01). In contrast to previous reports stating that SPN express the progesterone and/or estrogen receptors, which are absent in other pancreatic tumors, our results show that one-third of SPN were positive for the progesterone receptor. Downregulation of p21 was found more frequently in NFICT (40%) than SPN (17%). The mean value of the Ki-67 proliferation index for NFICT (2.77% +/- 2.53%) was significantly higher than that for SPN (0.94% +/- 0.89%; P = 0.043). These results are consistent with NFICT having more malignant behavior than SPN.

Are Pancreatic Tumors Hormone Dependent?: A Case Report of Unusual, Rapidly Growing Pancreatic Tumor during Pregnancy, Its Possible Relationship to Female Sex Hormones, and Review of the Literature

The occurrence of a pancreatic tumor in a young patient is rare. However, when one identifies a pancreatic mass during pregnancy and particularly when the lesion is located in the tail of the pancreas, “unusual tumors” of the pancreas should be considered. The management of these tumors during pregnancy presents unusual challenges because of rapid tumor growth probably related to elevated levels of sex hormones. An immunohistochemical study was done to evaluate for hormone receptors of the tissue removed from the tumor. We present a case of a 37-year-old female patient in her 4th week of pregnancy who was found to have a pancreatic mass; she was followed with ultrasonography. At the 23rd week of gestation, the tumor increased in size to more than 12 cm and required resection. Immunohistochemical studies were done to evaluate receptors for progesterone, estrogen, PS2-estrogen-related protein, pancreatic polypeptide antigen, flow cytometry, DNA ploidy, and proliferative activity in tumor cells. Pathology showed a low-grade multiloculated mucinous cystic neoplasm of the pancreas. There was a positivity for progesterone receptor and PS2-estrogen-related protein but not for estrogen receptor in the tumor. We conclude that a pancreatic mass detected during pregnancy requires a different consideration for its management. Early tissue diagnosis with CT or ultrasound-guided biopsy is essential. Even those lesions diagnosed as benign would require early intervention because of their rapid growth, probably influenced by female sex hormones.

Papillary-cystic neoplasm of the pancreas. A sex-steroid dependent tumor

CONCLUSION

The rate of growth of a papillary-cystic tumor of the pancreas seemed to be enhanced by the concurrence of pregnancy. Progesterone receptors in the tumor were demonstrated by immunohistochemistry and by molecular biology methods.

BACKGROUND

Papillary cystic tumor of the pancreas is extremely rare, occurring predominantly young females. Owing to the low frequency of the tumor, there is scarce information about the conditions that promote tumor growth.

METHODS

In this report, we present the temporal association between very rapid growth of a papillary-cystic neoplasm and pregnancy. Clinicopathological, immunohistochemical, and molecular biology analyses were performed.

RESULTS

A 21-yr-old woman was admitted because of recurrent epigastric abdominal pain associated with episodes of nausea and vomiting, and a history of an abdominal tumor of about 50 mm near the head of the pancreas, detected by ultrasound. On admission the patient had a flat, nontender abdomen without palpable masses. Laboratory analysis including hematologic and hepatic tests were strictly normal; only CA 19-9 (42 U/mL, normal 37 U/mL) was above normal values. One week after admission, an abdominal computerized axial tomography (CAT) scan revealed an 81.6-mm cystic mass localized in the head of the pancreas, and 1 wk later, in a laparotomy, a papillary-cystic neoplasm of 120 mm, limited to the head of the pancreas, was found. Three months later, in a routine follow-up visit, an 18-wk pregnancy was clinically diagnosed and confirmed by ultrasound exploration. The pregnancy continued without complications, and a normal male infant (3.7 kg) was born at 39 wk of gestation, by vaginal delivery. Eighteen months after tumor resection, the patient was asymptomatic and her child was in good health. We propose that progesterone affects tumor growth.

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

In steroid target tissues, the presence of the corresponding hormone receptors is indicative of hormone dependence. In an attempt to assess the possible role of steroid hormones in the mechanism of growth and/or differentiation of cancerous pancreatic duct cells, the expression of estrogen receptor (ERalpha) was evaluated in human cancerous pancreatic duct cells (Capan-1) maintained in culture. These cells were selected as they acquire progressively a high degree of differentiation during growth in culture. In the present study, we showed that Capan-1 cells during growth in steroid-free medium associate spontaneously, become polarized, and form duct-like structures, features that are indicative of a high degree of differentiation. Capan-1 cells were also found to express ERalpha and progesterone receptor (PR). Immunoenzymatic assay showed maximal expression of ERalpha (236 +/ 55 fmol/mg protein) on the first day of the exponential growth phase, followed by a marked fall in expression (76.3%). At the onset of the stationary phase (Day 5), ERalpha levels were below 10 fmol/mg protein, becoming undetectable by Day 7. A similar time course was observed for PR: 18 +/- 0.9 fmol/mg protein at the onset of the exponential growth phase and no expression during the stationary phase. Addition of estradiol to 1-d-old cultures resulted in a twofold increase in PR expression, suggesting an induction of PR expression by estrogen. Immunocytochemical analysis with anti-ERalpha-1D5 antibodies showed nuclear and cytoplasmic localization of ERalpha in Capan-1 cells in the first 24 h of culture followed by a progressive disappearance thereafter. We also showed that cellular multiplication was increased by estradiol and progesterone during the exponential growth phase, pointing to the involvement of steroid hormones in the proliferation of nonpolarized Capan-1 cells. These results indicate that the expression of ERalpha is linked to the state of differentiation of the cells and make Capan-1 cells a model of choice to study ER regulation in nontarget tissues.

Papillary cystic and solid tumors of the pancreas: a pancreatic embryonic tumor? Studies of three cases and cumulative review of the world's literature

BACKGROUND

The papillary cystic and solid tumor of the pancreas is rare. It occurs predominantly in young women, and most present a benign behavior. The pathogenesis of this tumor has attracted a number of investigations but remains unclear.

METHODS

We present three patients with this tumor and a review of 289 others from the world's literature, a total of 292 cases. On the basis of the analyses of the clinical and pathologic features from the reported cases, the pathogenesis of this unusual tumor has been further explored.

RESULTS

Ninety percent of the patients were female, with a mean age of 23.9 years. The tumors were usually quite large with a mean diameter of 10.3 cm. Ninety-two percent of these tumors were totally or partially cystic. Rupture of the capsule resulted in hemoperitoneum in eight cases, five of which were without any identifiable cause. Forty-three tumors (14.7%) have been recognized as malignant. The overall prognosis has been excellent and an aggressive approach to resection is indicated.

CONCLUSIONS

The results of immunohistochemical staining and electromicroscopy were rather diverse, but most, including the current cases, support the hypothesis that the tumor originates from pleuripotential embryonic stem cells. Thus the term pancreatic embryonic tumors seems preferable to papillary cystic and solid tumor of the pancreas to delineate the origin of the tumor and to reflect some of its biologic characteristics.

Expression of progesterone receptors in solid-cystic tumour of the pancreas: a clinicopathological and immunohistochemical study of ten cases

A role for sex hormones in the pathogenesis of solid-cystic tumour (SCT) of the pancreas is suggested by its predilection for young fertile women. Controversial data have been provided for the presence of progesterone receptors (PR) and/or oestrogen receptors (ER) in SCT. We report the immunohistochemical detection of PR in ten cases of SCT. Eight were from young women. The remaining two were from a post-menopausal woman and a young boy. All cases showed PR immunoreactivity in the large majority of neoplastic cells, whereas none exhibited ER positivity. In one tumour two types of cell populations were noted, the more anaplastic invasive-type being PR negative, whereas the more typical was PR positive. PR immunoreactivity in the absence of ER may simply reflect a lower sensitivity of ER antibody failing to reveal the biochemically detectable ER, or that the PR in cells of SCT are constitutively synthesized in an oestrogen-independent way, as in T47D breast carcinoma cell line, meningioma cells and some gastric cancer cells. Our findings support the hypothesis of a possible pathogenetic role of progesterone in SCT, independent of the patient's sex and age.

Papillary cystic tumor of the pancreas. Is it a hormone-dependent neoplasm?

In order to attempt to examine the question of whether papillary cystic tumors (PCT) of the pancreas represent a hormone-dependent neoplasm or not, three cases of PCT were biochemically and immunohistochemically investigated. The patients included a 27-year-old man, a 14-year-old girl and a 21-year-old female. Two of the three patients showed measurable biochemical levels of progesterone receptor in the tumors by the dextran-coated charcoal (DCC) method, and an immunohistochemical study revealed that the nuclei of the tumor cells in all the three cases were diffusely positive for progesterone receptor. In the literature, there have been more than 300 female patients of PCT with a significant minority of only twenty male patients, and the mean age of the cases with PCT in men (31.4 years old) is higher than that in women (25.5 years old) (P < 0.05). These results therefore suggest that PCT is a sex hormone-dependent neoplasm.

Solid and cystic pancreatic tumors. Clinical, histochemical, and electron microscopic features in ten cases

Ten cases of the rare solid and cystic pancreatic tumors are presented. All except one occurred in young women (mean age, 25 +/- 9.2 years). The large neoplasms were evenly distributed across the pancreas; in one case, metastasis occurred; all other cases were free from disease after complete resection. Histologic hallmarks of solid and cystic neoplasms were papillary growth, large intracytoplasmic granules, and immunoreactivity with alpha 1-antitrypsin, alpha 1-antichymotrypsin, phospholipase A2, and neuroendocrine markers (neuron-specific enolase [NSE], synaptophysin). This suggests both endocrine as well as exocrine differentiation.

Type-II estrogen binding sites in a lymphoblastoid cell line and growth-inhibitory effect of estrogen, anti-estrogen and bioflavonoids

Type-II estrogen-binding sites (type-II EBS) have been demonstrated in the human lymphoblastoid cell line IM-9 using a whole-cell assay with (6,7-3H) estradiol (3H-E2) as tracer. Competition analysis showed that the anti-estrogen tamoxifen and the flavonoids quercetin and rutin competed for (3H)-E2 binding to type-II EBS. Growth experiments demonstrated that diethylstilbestrol (DES) tamoxifen (TAM), quercetin and rutin exerted a reversible dose-dependent inhibition of cell proliferation in the range of concentrations between 10 nM and 10 microM. The relative binding affinity of quercetin, rutin, DES and TAM for type-II EBS correlated well with their potency as cell growth inhibitors. Moreover, hesperidin, a flavonoid which does not bind to type-II EBS, was ineffective in inhibiting cell growth. Cell-cycle analysis showed that the growth-inhibitory effect of DES, TAM or quercetin was due to a blocking effect in the G0-G1 phases. Our results suggest that high estrogen and anti-estrogen concentrations and flavonoids may regulate IM-9 cell growth through a common mechanism involving a binding interaction with type-II EBS.

Type II oestrogen binding sites in human colorectal carcinoma

Seven cases of colorectal adenocarcinomas were investigated for the presence of oestrogen receptors and progesterone receptors. The tumours specifically bound oestradiol. This binding almost exclusively resulted from the presence of high numbers of type II oestrogen binding sites. Oestrogen receptors were absent or present at very low concentrations. Immunohistochemical investigation of nuclear oestrogen receptors gave negative results. This indicates that antioestrogen receptor antibodies recognise oestrogen receptors but not type II oestrogen binding sites. The presence of specific type II oestrogen binding sites and progesterone binding offers further evidence for a potential role for these steroids and their receptors in colorectal carcinoma.