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

The influence of sex hormones on renal cell carcinoma

Kidney cancer is a common malignancy that constitutes around 5% of all cancer cases. Males are twice as likely to acquire renal cell carcinoma (RCC) compared to females and experience a higher rate of mortality. These disparities indicate that sex hormone (SH)-dependent pathways may have an impact on the aetiology and pathophysiology of RCC. Examination of SH involvement in conventional signalling pathways, as well as genetics and genomics, especially the involvement of ribonucleic acid, reveal further insights into sex-related differences. An understanding of SHs and their influence on kidney cancer is essential to offer patients individualized medicine that would better meet their needs in terms of prevention, diagnosis and treatment. This review presents the understanding of sex-related differences in the clinical manifestation of kidney cancer patients and the underlying biological processes.

Sex and Gender Differences in Kidney Cancer: Clinical and Experimental Evidence

Simple Summary

Kidney cancer is a frequent malignant tumor that accounts for approximately 5% of all cancer incidences. It affects both males and females, but males are twice as likely to develop kidney cancer than females. Evidence shows that this discrepancy takes root in individual differences, such as genetics or pathologies that affect the patient. It is then reflected in the clinical characteristics of the tumors, as males have larger and more aggressive tumors. Understanding the sex- and gender-based differences in kidney cancer is essential to be able to offer patients individualized medicine that would better cover their needs in terms of prevention, diagnosis and treatment.

Abstract

Sex and gender disparities have been reported for different types of non-reproductive cancers. Males are two times more likely to develop kidney cancer than females and have a higher death rate. These differences can be explained by looking at genetics and genomics, as well as other risk factors such as hypertension and obesity, lifestyle, and female sex hormones. Examination of the hormonal signaling pathways bring further insights into sex-related differences. Sex and gender-based disparities can be observed at the diagnostic, histological and treatment levels, leading to significant outcome difference. This review summarizes the current knowledge about sex and gender-related differences in the clinical presentation of patients with kidney cancer and the possible biological mechanisms that could explain these observations. Underlying sex-based differences may contribute to the development of sex-specific prognostic and diagnostic tools and the improvement of personalized therapies.

Tamoxifen attenuates renal fibrosis in human kidney slices and rats subjected to unilateral ureteral obstruction

BACKGROUND AND PURPOSE

Renal fibrosis plays an important role in the development and progression of chronic kidney disease (CKD). Clinical studies have shown that CKD progresses differently in males and females, which may be related to circulating levels of sex hormones. In this study, we investigated the effect of tamoxifen (TAM), a selective estrogen receptor modulator (SERM), on renal fibrosis in male and female rats subjected to unilateral ureteral obstruction (UUO) and human precision-cut kidney slices (PCKS).

EXPERIMENTAL APPROACH

Female, ovariectomized female (OVX), and male rats were subjected to 7 days of UUO and treated with TAM by oral gavage. Moreover, we studied individual responses to TAM treatment in PCKS prepared from female and male patients. In all models, the expression of fibrosis markers was examined by western blot, qPCR, and immunohistochemistry.

KEY RESULTS

TAM decreased the expression of fibronectin, α-smooth muscle actin, and collagen-1 and -3 in female, OVX, and male rats. In addition, TAM mitigated TGF-β-induced fibrosis in human PCKS, irrespective of sex, yet interindividual differences in treatment response were observed.

CONCLUSION AND IMPLICATIONS

TAM ameliorates renal fibrosis in males and females, although we did observe sex differences in drug response. These findings warrant further research into the clinical applicability of TAM, or other SERMs, for the personalized treatment of renal disease.

Hormone Treatment and Sex Steroid Receptors in Metastatic Renal Cell Carcinoma: Report of a Multicentric Prospective Study

Twenty-eight patients with metastatic renal cell carcinoma entered a multicentric prospective study to evaluate the response to high-dose medroxyprogesterone acetate (MPA) and testosterone in MPA failures in relation to sex steroid receptors. No objective remission was seen in the 24 evaluable patients, and only disease stabilizations of short duration were achieved in one-third of treated patients. Stabilizations achieved with second line testosterone were all seen in patients unresponsive to MPA. Receptor studies demonstrated that estrogen, progesterone, or androgen receptors were found in low concentrations and in only 6 of 23 tumors (26%) and 13 normal tissue samples (56%). Surprisingly, no disease stabilization was achieved in patients positive for receptors. It can be concluded that the occasional objective responses to hormone therapy reported in the literature may have been due to some cytotoxic effect of hormone therapy rather than to a true hormonal mechanism.

Evaluation of steroid hormones and their receptors in development and progression of renal cell carcinoma

Steroid hormones and their receptors have important roles in normal kidney biology, and alterations in their expression and function help explain the differences in development of kidney diseases, such as nephrotic syndrome and chronic kidney disease. The distinct gender difference in incidence of renal cell carcinoma (RCC), with males having almost twice the incidence as females globally, also suggests a role for sex hormones or their receptors in RCC development and progression. There was a peak in interest in evaluating the roles of androgen and estrogen receptors in RCC pathogenesis in the late 20^th century, with some positive outcomes for RCC therapy that targeted estrogen receptors, especially for metastatic disease. Since that time, however, there have been few studies that look at use of steroid hormone modulators for RCC, especially in the light of new therapies such as the tyrosine kinase inhibitors and new immune therapies, which are having some success for treatment of metastatic RCC. This review summarises past and current literature and attempts to stimulate renewed interest in research into the steroid hormones and their receptors, which might be used to effect, for example, in combination with the other newer targeted therapies for RCC.

Expression of the glucocorticoid receptor in renal cell neoplasms: an immunohistochemical and quantitative reverse transcriptase polymerase chain reaction study

Glucocorticoid receptors mediate the action of steroid hormones in a variety of tissues, including the kidney. Our goal was to determine the expression pattern and prognostic significance of glucocorticoid receptor in renal cell neoplasms. Paraffin-embedded microarrays from 200 patients with RCNs including 147 clear cell renal cell carcinomas, 23 papillary, 16 chromophobe renal cell carcinoma, and 14 oncocytomas were analyzed for glucocorticoid receptor expression by immunohistochemistry. Glucocorticoid receptor expression was also quantitated by real-time reverse transcriptase polymerase chain reaction in 45 cases (33 clear cell renal cell carcinomas, 5 chromophobe renal cell carcinomas, and 3 oncocytomas). Strong nuclear glucocorticoid receptor expression was present in normal glomeruli and in the proximal convoluted tubules. Nuclear glucocorticoid receptor expression was found in most clear cell renal cell carcinomas (66%), in 26% of papillary renal cell carcinomas, and in only 6% of chromophobe renal cell carcinomas and 14% of oncocytoma (P < .005). Within the clear cell renal cell carcinoma group, most positive cases (87%) demonstrated strong immunoreactivity (2+ and 3+), whereas only 1 papillary renal cell carcinoma, 1 chromophobe renal cell carcinoma, and none of the oncocytomas showed strong expression. Glucocorticoid receptor α messenger RNA expression was significantly higher in clear cell renal cell carcinoma than in chromophobe renal cell carcinoma, oncocytoma, or in the normal kidney. Significantly more frequent glucocorticoid receptor expression was associated with tumors of low nuclear grade (Fuhrman grade 1 and 2) and low stage (stages 1 and 2; P = .0068 and P = .0002). Survival analysis revealed a significant direct correlation between glucocorticoid receptor expression and overall survival in clear cell renal cell carcinoma (P = .01). In summary, strong glucocorticoid receptor expression was most commonly seen in clear cell renal cell carcinoma and only rarely seen in other subtypes. The glucocorticoid receptor expression pattern in RCNs seems to reflect the histogenetic origin of clear cell renal cell carcinoma from the proximal nephron. Finally, glucocorticoid receptor expression proved to be a marker of less aggressive behavior in clear cell renal cell carcinoma.

Down-regulation of vascular endothelial growth factor in renal cell carcinoma cells by glucocorticoids

Metastatic renal cell carcinomas (RCC) remain highly resistant to systemic therapy. RCCs are highly vascular tumors, which overproduce angiogenic peptides such as vascular endothelial growth factor (VEGF) even under normoxic conditions. A potential suggested role of antiangiogenic therapeutic strategies is the treatment of RCC by inhibiting VEGF production. The down-regulation of VEGF expression by glucocorticoids has recently been demonstrated in several cells. In this study, the direct effects of glucocorticoids on VEGF production by RCC cells were evaluated. Four RCC cell lines A498, RCC270, Caki1, and ACHN were treated with dexamethasone (DEX), hydrocortisone (HC), 5-alpha-dihydrotestosterone (DHT), or estradiol (E2). RU486 was used as a glucocorticoid receptor (GR) antagonist. Cell growth was studied with MTS assays. VEGF mRNA and protein were evaluated with quantitative real-time RT-PCR and ELISA, respectively, and GR expression was examined using RT-PCR and immunocytochemistry. All four RCC cell lines expressed GR. DEX at 100 nM down-regulated VEGF secretions by more than 50% in three lines (A498, RCC270, and Caki1) and had a weak inhibitory effect on ACHN cells. The effect of DEX on reducing VEGF mRNA levels in A498 cells was concentration-dependent and maximal at 100 nM (80% inhibition). HC had similar but weaker effects on VEGF production in the RCC cells, but E2 and DHT had no effect. RU486 reversed the effects of DEX. DEX at 1-1000 nM did not affect cell growth in any of the four RCC cell lines. This is the first study showing that glucocorticoids, at concentrations achievable in vivo by oral administration of low doses of DEX, have an inhibitory effect on VEGF mRNA expression and protein secretion of RCC cells possibly through the GR pathway. Furthermore, DEX might have a potential role in antiangiogenic therapeutic strategies by inhibiting VEGF production during metastatic RCC treatment.

Estrogen receptor alpha polymorphisms and renal cell carcinoma--a possible risk

Renal cell carcinoma is the most common form of kidney cancer. However, the genetic basis of renal cancer is not fully understood. Estrogens and their receptors (ERs) have been shown to play a role in various cancers and it is speculated that they can also affect the human kidney. One of the animal models utilized to study the effects of estrogens on renal cancer is the Syrian hamster. Exposing these hamsters to estrogens results in the development of kidney cancer and thus, the hormone-ER complex may be playing a role. The ER is expressed in reproductive as well as non-reproductive tissues and is implicated in the control of proliferation, differentiation, and development of many tissues. There are two types of ERs and they are the alpha and beta forms. Genetic polymorphisms of various factors have been shown to play a role in the alteration of their functions. The NH2-terminal region of the ERalpha protein influences its structure and function and thus, inherited variants of the ERalpha gene may alter tissue responsiveness to estrogens and possibly lead to renal carcinogenesis. Polymorphisms have been determined in the coding region of the human ERalpha gene and are located at the following codons: 10 T-->C, 85 G-->C, 87 G-->C, 243 C-->T, 325 C-->G, and 594 G-->A. There are also two polymorphisms that have been identified in intron 1 and give rise to a PvuII and XbaI restriction site. These polymorphisms of ERalpha have been shown to be associated with various cancers. Based on the evidence, it is hypothesized that polymorphisms of the ERalpha gene are associated with renal cell carcinoma.

Coactivation of an endogenous progesterone receptor by TIF2 in COS-7 cells

Transfection experiments, a powerful tool to study the function of steroid hormone receptors and their coregulators, are often performed in COS-7 cells, because of high transfection efficiencies and expression levels. Here we report on the presence in COS-7 cells of an endogenous steroid hormone receptor, which is highly responsive to progesterone and the synthetic steroids R1881 and ORG2058, but not to 5 alpha-DHT. A 10-fold excess of the progesterone antagonist RU486 abolishes the stimulation by progesterone, while cotransfection with the coactivator TIF2 increases its activity 6- to 7-fold. A comparison of the ligand specificity with transfected androgen or progesterone receptors indicates that the endogenous receptor is a progesterone receptor. Its presence is confirmed by steroid-binding experiments, RT-PCR and Northern blot analysis. Consequently, progesterone receptor function may be studied conveniently in COS-7 cells without cotransfection of receptor, but the endogenous receptor may interfere in studies of ligand specificity and coactivation of cotransfected receptors.

Hormone receptors in renal cancer: an overview

The current literature concerning hormone receptors in renal cell cancer is reviewed. Our own results of histochemical determination of estrogen receptors by means of monoclonal antibodies are presented. Based on the studies that have been reviewed and the differing results of the receptor assays, we conclude that there is a very limited basis to apply hormone therapy in renal cell cancer. However, the new immunohisto-chemical methods should be used to resolve the question about the hormone dependency of renal carcinoma.

Adjuvant medroxyprogesterone acetate and steroid hormone receptors in category M0 renal cell carcinoma. An interim report of a prospective randomized study

From July 1, 1979 to June 30, 1983, 136 consecutive patients with category M0 renal cell cancer who had undergone transperitoneal radical nephrectomy at 5 centers entered a prospective randomized trial to compare 500 mg. adjuvant medroxyprogesterone 3 times a week for 1 year to no treatment. Sex steroid hormone receptors also were studied in the renal tumor and in the surrounding healthy parenchyma with the dextran-coated charcoal technique. After a median followup period of 3 years (range 13 to 60 months) 30 of 121 evaluable patients (24.8 per cent) experienced relapse, usually in the lung or bones. Relapses occurred in 15 of 58 evaluable patients in the adjuvant treatment group (25.8 per cent) and 15 of 63 evaluable controls (23.8 per cent). The disease recurred more frequently (35.1 per cent) in the 57 patients with no receptors in the tumor than in the 45 with at least 1 receptor (17.8 per cent). These results were independent of adjuvant therapy. After a median 3-year followup, adjuvant medroxyprogesterone acetate was of no therapeutic benefit in patients who had undergone radical nephrectomy and the side effects of the therapy were evident in more than 50 per cent of the patients.

Effects of steroid hormone therapy on primarily xenotransplanted human colorectal adenocarcinomas

Primary xenotransplantation of six different human colorectal adenocarcinomas onto nude mice yielded a mean tumor take of 85%. Administration of steroid hormones induced tumor remissions in some cases. Neither the stage of the original patient's tumors nor their hormone receptor content seemed to be related to the result of the hormone therapies. It is concluded that some colorectal cancers can be treated as hormone-sensitive tumors.

Steroid hormone receptors in normal and malignant human renal tissue: relationship with progestin therapy

Documented hormone dependence of renal tumors in animal models, hypothetical hormonal environment of human kidney neoplasms and their controversial response to endocrine therapy prompted us to undertake a prospective multicentric cooperative study to evaluate the hormone-dependence/responsiveness of renal tumors. Patients with renal carcinoma were stratified according to the TNM classification and after nephrectomy were treated with high-dose medroxyprogesterone acetate (MPA). Specimens of tumor and healthy surrounding kidney tissue were studied for titration of steroid receptor proteins (78 for androgen, AR, 89 for estrogen, ER, and progestin, PgR). Their true receptor nature was estimated. Very low titers (on an average less than 10 fmol/mg protein) were found, especially for ER and PgR in neoplastic samples. Occurrence rate of AR was low for both tissues (less than 20%), whereas ER and PgR were detected at a higher frequency in healthy parenchyma than in tumor tissue (42.2 vs 23.3% and 30.7 vs 11.2%, respectively). AR was moderately affected by metastatic status of the disease and by sex. All three steroid receptors were simultaneously detected in normal tissue in 11.7% of cases and in tumor tissue in only 3.8%. No significant correlation between receptor status in the tumor and clinical response to hormone therapy was found. In 27 cases who received adjuvant MPA therapy, relapses were respectively 43.8 and 18.2% in the patients with negative receptors or with at least one detectable receptor. In metastatic renal carcinoma, stabilization of the disease with MPA was achieved more frequently in receptor-negative patients. Therefore, we conclude that the receptor assay is not a valid tool to select renal carcinoma patients for therapy with MPA.

Steroid receptors in renal cell carcinoma: relevance to hormonal therapy

The relevance of the presence of steroid receptors in the response to hormonal therapy was examined in 19 patients with renal cell carcinoma who were treated by surgery and progestins. Estrogen and progesterone receptors were determined in tissue samples obtained from the tumors, and normal (autologous) and control kidneys. The tumoral tissues had the lowest content of estrogen and progesterone receptors, and the lowest percentage of samples positive for receptor. Autologous kidneys had a higher percentage of positive estrogen and progesterone receptors compared to tumoral tissues, and a lower estrogen receptor content compared to control kidneys. The 18-month survival rate under progesterone therapy for 9 patients with stages I and II tumor was 86 per cent and for 10 with stage IV tumor it was 8 per cent. The low content of progesterone and estrogen receptors in patients with renal cell carcinoma may explain the poor response rate of these patients to hormonal therapy.

Clinical aspects of steroid hormone receptors in human renal cell carcinoma

A review of the role of steroid hormone receptors and hormonal dependence of renal cell carcinoma in certain patients is presented. The results of a cumulative series of estrogen, progesterone, and androgen receptor assays performed on 48 normal and malignant human renal tumor specimens are given. The detectable presence of receptor proteins in certain patients could obviate the empirical use of hormonal therapy, an issue that may be resolved through a randomized multiinstitutional trial.

Measurement of progesterone receptor in human renal cell carcinoma and normal renal tissue

Progesterone receptor was measured in eight samples of renal cell carcinoma, nine samples of normal renal tissue, and one sample of melanoma tissue. Progesterone receptor was identified in all samples, with the exception of one renal cell carcinoma. Three patients, all with receptor-positive tumors, were treated with medroxyprogesterone acetate for metastatic disease. In one of these patients there was a partial objective response to treatment. Further research regarding progesterone receptor in renal cell carcinoma is indicated.