Effects of glucocorticoids on the growth of human fibrosarcoma cell line HT-1080

The human fibrosarcoma cell line HT-1080 exhibits rapid growth following s.c. inoculation in 4-6-week-old male athymic mice. Cytosols from tumors carried in athymic mice bind glucocorticoid (Kd, 1.8 +/- 0.48 X 10(-8) M; Bmax, 240.5 +/- 35.3 fmol/mg cytosol protein, mean +/- SEM). Receptor sediments primarily in the 8-9S region on 5-20% sucrose gradients and is specific for the glucocorticoids. HT-1080 growth in vitro (as measured by cell count) was inhibited over a range of 10(-6)-10(-8) M after 7 days of incubation with dexamethasone and triamcinolone acetonide. Progesterone, estradiol, and dihydrotestosterone had no effect on HT-1080 growth in vitro. Preincubation with a 100-fold excess of progesterone reversed the growth inhibition observed with triamcinolone acetonide but not dexamethasone acetate. HT-1080 tumor cell growth responded biphasically to dexamethasone in vivo. Athymic mice given s.c. injections every other day with 5 or 25 micrograms dexamethasone showed an increase in tumor size inversely proportional to dose. In contrast, 200 micrograms of dexamethasone significantly inhibited tumor growth. Adrenalectomy did not significantly alter HT-1080 growth or glucocorticoid binding to tumor cytosols (Kd, 3.4 X 10(-8) +/- 1.1, Bmax, 236.9 +/- 9.9 fmol/mg cytosol protein, mean +/- SEM) although tumor incidence was decreased in sham adrenalectomized mice. Glucocorticoid binding in tumors grown in vivo was decreased by increasing amounts of dexamethasone. High pharmacological doses of glucocorticoids inhibit the growth of human fibrosarcomas in vivo and in vitro.     

Status of sex steroid hormone receptors in large bowel cancer

To determine the potential role of sex steroid hormones in the development of colorectal tumors in humans, specific androgen (AR), estrogen (ER), and progesterone (PGR) receptors were investigated in normal mucosa (NM) and in tumor (T) paired biopsy specimens from 94 patients. Androgen receptors were detected in 98% and 96% of NM and T samples, ER in 91% and 83% of NM and T biopsy samples, whereas PGR were detected only in 14% and 10% of NM and T specimens, respectively. These incidences are independent of the sex and age of the patients. They are not related to tumor localization, histologic grade, or stages of Dukes' classification. Scatchard analysis of labeled ligand binding indicated the existence of one single class of high affinity binding sites; the calculated dissociation constant (Kd) was 1.7 +/- 0.6 10(-9) molar concentration (M) for 5 alpha-dihydrotestosterone (DHT) and 0.6 +/- 0.3 10(-9) M for estradiol (E2). These values were identical in NM and T tissue for both AR and ER. The binding capacity for DHT was 148 +/- 67 and 93 +/- 43 fmol/mg of cytosol protein in NM and T tissues, respectively (P less than 0.05). The ER content was lower and similar in NM and T biopsy specimens: 19 +/- 9 and 18 +/- 10 fmol/mg protein, respectively. The PGR content was 10 +/- 4 in NM versus 17.5 +/- 6 fmol/mg protein in T specimens. It is observed that the elevated AR in normal mucosa is not related to any known function for androgens in the digestive tract. The receptor pattern observed in tumors does not support the hypothesis previously raised in the case of chemically induced colonic tumors in rodents.     

Gonadotrophin releasing hormone (GnRH) receptor and steroid receptors in human uterine leiomyoma, myometrium and endometrium

The present study evaluated the presence of GnRH-R in leiomyomas, in associated, non-involved uterine tissues (myometrium and endometrium) and the possible relationships between GnRH-R and the receptors for estrogen and progesterone in the same tissues. GnRH-R was found in all uterine tissues and both GnRH and the GnRH analog, goserelin, displaced its binding consistent with a single type of high affinity receptor (Kd approximate to 10(-8) M). GnRH-R were found more frequently in myometrium (81% of samples) than in endometrium (58%) or leiomyoma (42%). However, the mean receptor content was lowest in myometrium (139+/-19 fmol/mg protein) with both leiomyomas (288+/-77 fmol/mg protein) and endometrium (372+/-96 fmol/mg protein) having significantly higher values. Endometrial GnRH binding varied from 596+/-42 in uteri that were GnRH-R positive in the endothelium alone to 231+/-49 when GnRH-R was present also in the other tissues. Endometrium negative for the GnRH-R had significantly higher levels of estrogen receptor than all the other uterine samples (266+/-25 vs 61+/-7.5 fmol/mg protein, respectively). Endometrial GnRH-R seem to be dependent on its presence and/or level in other uterine tissues. Further, when GnRH-R is absent in the endometrium this tissue expresses greatly increased levels of steroid receptors.     

Characterization of 3-methylcholanthrene effects on the rat glucocorticoid receptor in vivo

The effects of 3-methylcholanthrene and phenobarbital treatment on the adult rat hepatic cytosolic glucocorticoid (GRc) receptor were investigated. Analyses of sucrose gradient profiles and equilibrium binding data of [3H]dexamethasone bound to the GRc revealed that administration of 3-methylcholanthrene (20-40 mg/kg daily i.p. for 2 days) to adult female Fischer F344 rats led to a significant decrease in the maximal binding capacity of the 5-7S GRc [Bmax = 209 +/- 3 (SE) fmol/mg of protein] compared to the vehicle-treated controls (Bmax = 277 +/- 13 fmol/mg) but had no significant influence on the affinity of the GRc (Kd = 0.9 +/- 0.1 nM). This response was not dependent upon the sex or rat strain (female F344 versus Sprague-Dawley). Phenobarbital treatment (80 mg/kg daily i.p. for 4 days) decreased Bmax and Kd values compared to the vehicle treated controls (P less than 0.05). 3-Methylcholanthrene treatment did not significantly alter the equilibrium parameters of [3H]methyltrienolone bound to the hepatic androgen receptor indicating that the effect was specific to the hepatic GRc. Our data suggest that carcinogens and tumor promoters cause a functional decrease of the cytosolic glucocorticoid receptor in vivo.     

Characterization of estrogen receptor in human gastric cancer

Estrogen receptors (ER) were examined in cytosol, nuclear potassium chloride (KCl) extractable fraction, and nuclear KCl unextractable fraction by the dextran-coated charcoal adsorption method in various gastric cancer tissue. The overall ER-positive rate in the cytosol and nuclear fraction was 19.2%. The maximum binding site (Bmax) was 36.0 to 175.0 fmol/mg of protein, and the dissociation constant (Kd) was 0.6 to 1.6 X 10(-9) in cytosol fraction. In the nuclear fraction, Bmax was 7.5 fmol/mg of DNA and Kd was 2.3 X 10(-9). Estrogen receptors were characterized in cytosol protein. In cytosol, the estrogen (E2)-ER complex was sedimented at approximately the 5S and 8S regions by 5% to 20% linear sucrose gradient centrifugation. A steroid specificity study of ER showed the presence of an binder in gastric cancer tissue. In conclusion, these results that gastric cancer tissue has E2 binding sites with the same biochemical characteristics as in breast cancer and endometrial cancer strongly suggest the hormonal dependency of gastric cancer.     

Differences in oestrogen receptors in malignant and normal breast tissue as identified by the binding of a new synthetic progestogen

Oestrogen receptor protein (ER) was detected in 9 of 11 samples of malignant breast tissue and 8 of 9 samples of normal breast tissue. Levels of cytosolic ER (ERc) in malignant breast were 21-1102 fmol mg-1 soluble protein (Kd 1.8 X 10(-9)-3.1 X 10(-8) mol l-1) and those of nucleosolic ER (ERn), 13-526 fmol mg-1 soluble protein (Kd 2.1 X 10(-9)-1.4 X 10(-8) mol l-1). In normal breast tissue ERc levels were 33-640 fmol mg-1 soluble protein (Kd 1.3 X 10(-10)-3.2 X 10(-9) mol l-1), ERn was detected in only 2 samples, 8 and 87 fmol mg-1 soluble protein with Kd 3.2 X 10(-9) and 1.4 X 10(-9) l mol-1 respectively. 17 alpha-ethinyl-13 beta-ethyl-17 beta-hydroxy-4,15-gonadiene-3-one (gestodene), a new synthetic progestogen displaced 3H-oestradiol (3H-E2) from both ERc and ERn in malignant tissue but not in normal breast, or these receptors from endometrial tissue. In competition studies gestodene was approximately 3 times more effective in displacing 3H-E2 from ERc and ERn in malignant breast tissue than the natural ligand. Quantitation of ER by gestodene were ERc, 12-1134 fmol gestodene bound mg-1 soluble protein (Kd 1 X 10(-9)-8.1 X 10(-9) mol l-1); ERn, 17-531 fmol gestodene bound mg-1 soluble protein (Kd 1.6 X 10(-9)-1.1 X 10(-8) mol l-1). L-13-ethyl-17 alpha-ethinyl, 17 beta-hydroxy-gonen-3-one (levonorgestrel) showed no binding to ER in malignant breast, normal breast or endometrial tissue. In circulation both gestodene and levonorgestrel displaced E2 from sex hormone binding globulin more than any of the androgens tested. These results suggest that gestodene is a progestogen with oestrogenic and/or antioestrogenic properties and provide strong evidence for differences in ER from malignant and normal breast tissue.     

Prognostic value of estrogen and progesterone receptors measured by enzyme immunoassays in human breast tumor cytosols

Clinically significant cut-off values to discriminate between receptor-positive and -negative, and the prognostic value of estrogen receptors (ER) and progesterone receptors (PgR) measured by enzyme immunoassay (EIA) have not yet been established. We have therefore measured ER and PgR by EIA in cytosols from 205 primary breast cancer biopsies. Clinically significant cut-off values (30 fmol/mg protein for ER; 27 fmol/mg protein for PgR), as related to tumor recurrence (median follow-up, 47 months), have been established by isotonic regression analysis. These data were compared to those obtained by simultaneously performed dextran-coated charcoal (DCC) assays (cut-off values: 18 fmol/mg protein for ER, and 26 fmol/mg protein for PgR) on the same cytosols, and to DCC assays performed previously (up to 10 years ago) on cytosols prepared from other parts of the tissue biopsies (cut-off values: 18 fmol/mg protein for ER, and 23 fmol/mg protein for PgR). Using the cut-off values for the EIA and the DCC assays performed on the same cytosols, the discrepancies between receptor status appeared less than 10% both for ER and for PgR. Furthermore, the concentrations of ER or PgR detected with the EIA or DCC assay were highly and significantly correlated (Spearman rank correlations: for ER, Rs = 0.94; for PgR, Rs = 0.88; P less than 0.0001). After classification in different phenotypes with respect to ER/PgR status (+/+, +/-, -/+, and -/-), analysis for relapse-free survival and overall survival showed equal prognostic power in the comparable groups in the order, from favorable to unfavorable, of +/+ greater than +/-(-/+) greater than -/- (chi2: P less than 0.0001), irrespective of the assay which has been used for quantification of the receptor. It is concluded that both the conventionally used DCC and the newly available EIA methods are equally useful for assessing ER and PgR status.     

Comparison of steroid receptor levels in renal-cell carcinoma and autologous normal kidney

Since a number of renal-cell carcinomas regress with hormonal manipulation, we have identified and measured the levels of estrogen, progestin and glucocorticoid receptors in 47 autologous pairs of normal and neoplastic kidney tissues. High-affinity receptors for these hormones were detected in kidney tissues of both sexes by means of a dextran-coated charcoal assay. Glucocorticoid receptors were demonstrated in renal cancer tissues for the first time, and were higher in the tumor (mean 31.3 ± sem 5.6) than in the normal tissue (mean 18.5 ± sem 3.1 fmol/mg cytosol protein). There was a significant difference in the quantities of progestin receptors (expressed as fmol/mg cytosol protein) in normal (mean 18.4 ± sem 3.3) versus neoplastic (mean 10.4 ± sem 4.0) kidney specimens (p < 0.007). There was a significant difference between the binding affinity of the progestin receptor in the male tumors (Kd = 2.2 ± sem 0.9 nM, n = 10) and that of the females, (Kd = 9.3 ± sem 6.5 nM) (p < 0.04). When an affinity of < 9.9 × I0^?9M and > 10 fmol/mg cytosol protein were used as criteria for classifying a tissue as positive for progestin receptors, only 17% of tumors contained these receptors while 45% of normal tissues exhibited them. According to these criteria, no differences were observed in the frequency of occurrence of either estrogen receptors or glucocorticoid receptors in tumor versus normal kidney. Data from this study suggest that the use of endocrine therapy should be re-examined in the treatment of renal-cell carcinoma.     

Characterization of estrogen and progesterone receptors and the dissociated regulation of growth and progesterone receptor stimulation by estrogen in MDA-MB-134 human breast cancer cells

We have examined the properties of the estrogen receptor and progesterone receptor in MDA-MB-134 human breast cells and have evaluated the effects of estrogen on cell proliferation and progesterone receptor levels in these cells as indices of hormonal sensitivity. These cells contain high levels of estrogen receptor (approximately 1.5 pmol/mg DNA) and low levels of progesterone receptor (0.15 pmol/mg DNA). More than 80% of the estrogen receptor is found in the nuclear fraction in the absence of estrogen, and the Kd of the receptor for estradiol is approximately 1.5 X 10(-10) M. Upon exposure to estradiol, the receptors become occupied, but there is no processing or apparent decrease in either nuclear or total cellular estrogen receptor content, as can be seen in MCF-7 human breast cancer cells. The nuclear estrogen receptor sediments as a 4.6 S species on high salt sucrose gradients, and it can be detected on sodium dodecyl sulfate-polyacrylamide gel immunoblot analysis as a species of molecular weight 65,000, identical to that of the MCF-7 estrogen receptor, using the monoclonal antibodies D75P3 gamma and H222Sp gamma prepared against the MCF-7 estrogen receptor. The estrogen receptor shows binding selectivity for estrogens and antiestrogens, and its affinity for ligands follows the order diethylstilbestrol (190%) greater than estradiol (100%) greater than estriol (13%) greater than tamoxifen (3%), as expected for estrogen receptor. Hence the receptor appears normal in many of its physicochemical properties and in terms of its binding affinity and specificity for estrogens and antiestrogens. Control cells contain low levels of progesterone receptor that display high affinity (Kd = 6 X 10(-9) M) for the synthetic progestin R5020, but exposure to estradiol (10(-11)-10(-7)M) fails to increase cellular progesterone receptor levels. In contrast, estradiol markedly stimulates the rate of cell proliferation, while tamoxifen suppresses the growth of control and of estradiol treated cells. Hence, our data show that these cells, which contain substantial levels of estrogen receptor, respond to estrogen with enhanced cell proliferation but fail to have their progesterone receptor level modulated by estradiol. These cells represent an interesting and unusual situation in which estrogenic regulation of proliferation and the stimulation of progesterone receptor are dissociated. These cells should prove useful in further evaluation of estrogenic regulation of cell proliferation and specific protein synthesis in human breast cancer.     

Estrogen receptor in very small breast tumor specimens: a modified charcoal-gelatin assay

We described recently a modified charcoal-gelatin (MCG) assay for measuring progesterone receptor activity in low-protein cytosols. We showed that pre-mixing of gelatin with sample cytosols (final gelatin concentration 0.1%) and removal of unbound steroid by a 1% charcoal suspension with 0.1% gelatin but without dextran preserves the progesterone receptor activity in dilute cytosol. For estrogen receptor (ER), as for progesterone receptor, the efficiency of the standard dextran-coated charcoal (DCC) assay drops rapidly as samples are diluted much below 1 mg protein per ml. We have therefore applied the MCG procedure to the assay of ER in breast tumor cytosols. We find that MCG is far more efficient for ER at low protein concentrations than either the DCC method or three other methods recommended previously for dilute samples, retaining at least 60% efficiency even at 0.01 mg protein per ml. The measured Kd of the receptor for estradiol is the same by MCG as by DCC. A series of human breast tumor biopsies assayed by MCG at 0.1 mg protein per ml gave about the same ER values (fmol/mg) as at 1 mg/ml, while the DCC efficiency for ER at the lower concentration averaged only 32%. In combination with 125I-labeled estradiol, this MCG method should allow accurate ER assays of extremely small breast cancer specimens.     

The expression of mRNA for glucocorticoid receptor gene and functional glucocorticoid receptors detected in PA-III rat prostate adenocarcinoma cells.

The metastatic capacity of PA-III rat prostate adenocarcinoma cells has been well documented, although little is known about the biological and biochemical characteristics of PA-III cells. This study characterizes PA-III cells with regard to the presence or absence of glucocorticoid and androgen receptors. Cytosols of PA-III cells possessed [3H]-dexamethasone binding sites with association constant (Ka) 0.46 +/- 0.17 x 10(9) M-1 and number 341 +/- 175 fmols/mg protein. Displacement of [3H]-dexamethasone binding from PA-III cytosols achieved by increasing doses of unlabelled dexamethasone, corticosterone, cortisol, progesterone, deoxycorticosterone and aldosterone documented glucocorticoid binding specificity. Northern and dot blot analyses detected the expression of mRNA for glucocorticoid receptor using a 750 bp cDNA probe of the glucocorticoid receptor gene. Twenty-four hours incubation of PA-III cells with increasing amounts of dexamethasone resulted in a remarkable inhibition of the growth of PA-III cells. Binding studies with [3H]-R1881 as well as dot blot and Northern blot analyses using a 500 bp cDNA probe of androgen receptor gene could not detect the presence of androgen receptors in PA-III cells. The present study documented functional glucocorticoid receptors in the androgen-independent PA-III rat prostate adenocarcinoma cells. These results suggest that glucocorticoids may regulate important aspects of androgen-independent prostate cancer cells growth and functions.     

Inhibition of hamster melanoma growth by estrogen

A malignant hamster melanoma cell line HM-1 derived from the heterogenous malignant hamster melanoma MM1 contains a specific, high affinity binding protein for estrogens. Partial purification of the binding protein with ammonium sulfate (40% saturation) increased mean binding content (3.1 +/- 1.2 (SD) fmol/mg protein) 15-fold without any change in affinity (10(10) M-1). The binding protein sedimented at 8-9S on 10-30% low salt sucrose gradients and 9-10S in the presence of 20 mM molybdate ion. Addition of 0.4 M KCl shifted the 8S peak to 4S. Binding was specific, saturable, and indicative of a single class of high affinity sites over a concentration range of 0.01-10.0 nM [3H]estradiol. Estradiol produced a dose related inhibition of HM-1 growth in vitro without altering the growth of an additional line (HM-2) which did not bind estrogen. The antiestrogen tamoxifen (10(-7) M) also significantly inhibited HM-1 melanoma growth in vitro, which was reversed by the addition of estradiol (10(-9) M). HM-1 xenografts grew faster in female BALB/c-nu/nu mice than male mice while there was no sex difference in HM-2 growth. Pharmacological doses of estradiol and the antiestrogen nafoxidine significantly inhibited HM-1 growth without altering tumor incidence or latency. Our observations suggest that HM-1 cell lines bind estrogens specifically and with high affinity and that hamster melanoma cells positive for this binding protein respond to estrogen.     

DCC法检测食管鳞癌组织中雌,孕激素胞浆,胞核受体

对３０例原发食管鳞癌组织及１６例正常食管组织中雌、孕激素受体在胞浆和胞核（ＥＲｃ、ＥＲｎ、ＰｇＲｃ、ＰｇＲｎ）中分布进行分析，结果显示：正常食管组织中ＥＲｃ、ＥＲｎ、ＰｇＲｃ和ＰｇＲｎ均未检出；癌组织中上述受体含量分别为０～８４．６ｆｍｏｌ／ｍｇ蛋白、０～８７．７ｆｍｏｌ／ｍｇＤＮＡ、０～６８．０ｆｍｏｌ／ｍｇ蛋白和０～６９．４ｆｍｏｌ／ｍｇＤＮＡ，阳性率分别为３６．７％、３３．３％、３０％和３０％，受体含量及阳性率均明显高于正常食管组织（Ｐ＜０．０５）。上述受体阳性率随癌组织学分级增加而明显下降，且女性高于男性（Ｐ＜０．０５）。     

Regulation of estrogen-binding capacity by insulin in 7,12-dimethylbenz(a)anthracene-induced mammary tumors in rats

The role of insulin as a regulator of estrogen receptors (ER's) was investigated in 7,12-dimethylbenz(a)anthracene-induced mammary tumors in diabetic and insulin-treated rats. Induction of diabetes with streptozotocin produced regression of lesions classified as insulin dependent; lesions that continued to grow in diabetic rats were classified as insulin independent. Compared to tumors in intact hosts [ER, 39 +/- 4 (S.E.) fmol/mg cytosol protein], regressing insulin-dependent lesions had ER levels of 8.5 +/- 0.7 fmol, and insulin-independent tumors had ER levels of 24 +/- 3 fmol. Treatment of diabetic rats with insulin 8 IU/day, caused insulin-dependent regressing tumors to resume growth; these lesions had ER levels of 53 +/- 10 fmol. Insulin-independent lesions in diabetic rats demonstrated two patterns after treatment with insulin; continued growth resulted in tumors having ER levels of 28 +/- 11 fmol, whereas insulin-induced tumor regression resulted in tumors that demonstrated ER levels of 40 +/- 6 fmol/mg cytosol protein, a value equal to the level of ER in tumors growing in intact rats. Scatchard analysis of the saturation-binding data gave linear representations, and the estimated Kd for the ER was comparable for all groups, ranging from 0.44 to 1.90 x 10(-9) M. Several additional tumors were classified as demonstrating static growth. When this behavior represented a response due to insulin treatment, ER levels were elevated. Static tumors remaining static after insulin treatment demonstrated low ER levels. We conclude that (a) cessation of tumor growth after induction of diabetes resulted in reduction of ER levels, (b) treatment with insulin that resulted in an altered tumor growth was accompanied by elevated ER levels, and (c) insulin may play a role in regulation of ER independent of tumor growth.     

Medroxyprogesterone acetate inhibits the proliferation of estrogen- and progesterone-receptor negative MFM-223 human mammary cancer cells via the androgen receptor

Summary This study demonstrates for the first time, that medroxyprogesterone acetate (MPA) inhibits the proliferation of the estrogen and progesterone receptor negative mammary cancer cell line MFM-223 via the androgen receptor. MPA is a progestin, which is used in the hormonal treatment of disseminated breast cancer. It binds to the progesterone, androgen, and glucocorticoid receptor and may exert its antiproliferative effects via different receptors. MFM-223 human mammary cancer cells contain a very high level of androgen receptors (160 fmol/mg protein) and low levels of estrogen, progesterone, and glucocorticoid receptors (<20 fmol/mg protein). This cell line provides therefore a good model system to analyze the possible role of the androgen receptor in the action of MPA avoiding interference with other steroid hormone receptors. Effective inhibition of proliferation is achieved by 10 nM MPA or 1 nM of the androgen dihydrotestosterone, corresponding well to the binding affinities of both compounds (3.6 and 0.18 nM, respectively). The involvement of the androgen receptor was confirmed by competition experiments with antiandrogens. Furthermore, MFMDHT cells, which are an androgen resistant subline of MFM-223 cells, are also resistant to MPA. This data supports the involvement of the androgen receptor in the action of MPA and additionally rules out direct hormone-independent cytotoxic effects of MPA.Dedicated to Prof. Dr. Heinrich Maass, Director of the Department of Obstetrics and Gynecology of the University of Hamburg, on the occasion of his 65^th birthday.     

Sex steroid receptor proteins in foetal, adult and malignant human liver tissue.

Sex steroid receptor proteins were studied in human normal liver and hepatocellular carcinoma (HCC). Oestrogen receptor (ER) was detected in nucleosol and cytosol of 4 normal adult and 5 malignant liver specimens and in the cytosol of 6 foetal liver samples. Levels were 27.6-500 fmol mg-1 soluble protein in normal adults (Kd 1.48 X 10(-8) -1.12 X 10(-10) mol 1(-1) ), 45-290 fmol mg-1 in malignant liver tissue (Kd 3.26 X 10(-9) -3.64 X 10(-10) mol 1(-1] and a mean of 93 fmol mg-1 in foetal tissue (Kd 1.55 X 10(-9) mol 1(-1]. Androgen receptors (AR) were found only in cytosol and nucleosol of HCC (23-370 fmol mg-1) and in cytosol from foetal liver (29 fmol mg-1) with Kd from 2.90 X 10(-9) to 3.734 X 10(-10) mol 1(-1]. AR was distinguished from sex hormone binding globulin, which was also present in all cytosol samples, by the former''s ability to selectively bind to methyltrienolone and the latter''s absence from nucleosol. These findings provide further support for suggestions that oestrogen-related hepatic functions in man may be mediated by receptors and raise the possibility that hepatocellular carcinoma may be androgen dependent.     

Overexpression of cholecystokinin receptors in azaserine-induced neoplasms of the rat pancreas.

Cholecystokinin (CCK) is a growth factor for normal pancreas. Numerous studies also suggest that CCK promotes pancreatic carcinogenesis in the rat. Our previous studies suggested that growth of preneoplastic pancreatic foci was stimulated by CCK more than that of normal pancreas. We hypothesized that such differential growth might be due to increased numbers of CCK receptors in neoplastic tissue. Azaserine-induced pancreatic carcinoma (DSL6) had an increased high-affinity CCK receptor binding capacity of 122 +/- 23 (SD) fmol/mg protein compared to 12 +/- 2 fmol/mg protein in normal pancreas (P less than 0.001). The Kd of the high-affinity site was 0.33 +/- 0.04 nM for carcinoma and 0.46 +/- 0.08 nM for normal pancreas (P less than 0.01). The amount of cholecystokinin octapeptide (CCK-8) bound to high-affinity receptor was 8.6 +/- 1.9 fmol/mg protein for DSL6 compared to 0.6 +/- 0.2 fmol/mg protein in normal pancreas (P less than 0.001). Azaserine-induced premalignant nodules were compared to remaining internodular pancreas. Nodules demonstrated a mean high-affinity CCK receptor binding capacity of 38 +/- 9 fmol/mg protein compared to 6 +/- 3 fmol/mg protein in internodular pancreas (P less than 0.001). The amount of CCK-8 bound to high-affinity receptor was 3.1 +/- 0.8 fmol/mg protein in nodules compared to 0.6 +/- 0.3 fmol/mg protein in internodular pancreas (P less than 0.001). Overexpression of high-affinity CCK-8 receptor in premalignant and malignant azaserine-induced tumors may result in a growth advantage relative to normal pancreas.     

Acetylsalicylic acid (ASA) protects the prostaglandin-cAMP-system of human hypernephroma cells against irradiation-induced alterations.

There is abundant evidence that inhibitors of prostaglandin (PG) biosynthesis might increase the radioresponse of certain tumour cells. This study investigated specific PG binding sites, eicosanoid production as well as intracellular cAMP levels in cultured human hypernephroma cells derived from 11 patients upon nephrectomy. Scatchard analyses of the binding data revealed specific PGE1-, PGE2- as well as PGI2-binding sites (PGE1: Bmax = 755 +/- 206 fmol mg-1 protein, Kd = 3.7 +/- 2.7 nM PGE2: Bmax = 494 +/- 221 fmol mg-1 protein, Kd = 4.2 +/- 2.5 nM; PGI2: Bmax = 693 +/- 164 fmol mg-1 protein, Kd = 6.0 +/- 4.5 nM). Significant (P < 0.01) increase in PG binding sites expressed on human hypernephroma cells (PGE1: Bmax = 1084 +/- 303 fmol mg-1 protein, Kd = 2.8 +/- 1.3 nM; PGE2: Bmax = 663 +/- 309 fmol mg-1 protein, Kd = 2.2 +/- 1.5 nM; PGI2: Bmax = 1021 +/- 391 fmol/protein, Kd = 4.2 +/- 3.6 nM) and inhibition of PG biosynthesis (TXB2: -82.5%, PGE2: -87.5%. PGD2: -80.6%, PGF2: -81.3%) were found after acetylsalicylic acid (ASA)-treatment (0.5 mg 10(-6) cells for 24 h). Following irradiation (60Co, 1.0 Gy/min-1 over 10(min), PG binding sites (PGE1: Bmax = 266 +/- 153 fmol mg-1 protein, Kd = 5.0 +/- 5.0 nM; PGE2: Bmax = 148 +/- 66 fmol mg-1 protein, Kd = 4.7 +/- 3.6 nM; PGI2: Bmax = 325 +/- 194 fmol mg-1 protein, Kd = 6.8 +/- 7.1 nM) were significantly (P < 0.01) diminished. However, irradiation had no significant effect on PG binding sites in ASA-pretreated cells (PGE1: Bmax = 699 +/- 240 fmol mg-1 protein, Kd = 3.5 +/- 1.8 nM; iloprost: Bmax = 766 +/- 452 fmol mg-1 protein, Kd = 3.2 +/- 2.2 nM). Although there was no significant difference in the basal values for cAMP between control and ASA-treated group cells, the PG-induced cAMP-production was less pronounced in the control group. Taken together, the findings suggest that ASA may modify the radioresponse of cultured human hypernephroma cells by preventing the decrease of PG binding sites induced by irradiation.     

Hormone receptor status in human endometrial adenocarcinoma

Steroid receptor levels were determined in 196 samples of endometrial adenocarcinoma: cytosol estradiol receptors (ERc) were measured in 171 samples, cytosol progesterone receptors (PRc) in all samples; nuclear estradiol receptors (ERn) and nuclear progesterone receptors (PRn) in 68 samples; total estradiol receptors (ERt = ERc plus ERn) and total progesterone receptors (PRt = PRc plus PRn) were measured in 68 samples. The ERc levels were 88.2 +/- 8.9 (mean +/- SEM) and ERn were 94.4 +/- 15.6 fmol/mg protein; PRc levels were 197.9 +/- 25.9 and PRn 178.3 +/- 55.9 fmol/mg protein. The ERt levels were 162.6 +/- 23.2 and PRt 249.8 +/- 75.7 fmol/mg protein. The presence of PRc was related to the ERc levels according to the cut-off used. Estradiol receptors (ER) and progesterone receptors (PR) were present in the cytoplasmic and nuclear fractions in 60.2% and 36.8% of cases, respectively. The simultaneous presence of both ERt and PRt was observed only in 27.9% of cases. In the normal endometrium ERc and PRc were negatively correlated (r = -0.525, P less than 0.005), whereas in endometrial adenocarcinoma the correlation was positive (r = 0.491, P less than 0.001). In contrast with the normal endometrium the correlation between ERc and ERn was positive (r = 0.582, P less than 0.001) in tumor tissue. In neoplastic tissue Scatchard analysis showed a single class of specific ERc sites with a dissociation constant (Kd) of 1.39 +/- 0.8 X 10(-9) mol/l, one tenth of that found in the normal premenopausal endometrium. Qualitative and quantitative analysis of the receptor status showed that in 30% to 40% of cases studied the behavior of the neoplastic cell was similar to that found in the normal endometrial cell. In a 4-year follow-up of patients affected by endometrial adenocarcinoma there is better survival in the groups of patients with a simultaneous presence of ERt and PRt than in the group with their absence.     

Steroid receptor pattern of human colorectal neoplasms

Twenty-four colorectal carcinomas were assayed for estrogen and progestin receptors by sucrose gradient centrifugation. Most biopsies were either completely estrogen receptor negative or displayed low titers of specific estrogen binding. Only three tumors demonstrated moderate estrogen binding activity (10-18 fmol/mg cytosol protein). In four tumors specific progestin binding exceeded 20 fmol/mg protein. Only a minor subset of the binders sedimented at 8S. Twenty-one colorectal tumors examined for the presence of glucocorticoid receptors were found to be receptor positive, without exception. Biopsies from normal colorectal mucosa displayed minute quantities of specific 8S estrogen and progestin binding, but significant titers of specific glucocorticoid binding. Our findings support the hypothesis that estrogens and progestins are unlikely to play a major role in endocrine control of colorectal neoplasms. The role of glucocorticoids in growth control of colorectal neoplasms remains to be defined.