Renal cell carcinoma (RCC) originates in the lining of the proximal convoluted tubule and accounts for approximately 3% of adult malignancies. The RCC incidence rate increases annually and is twofold higher in males than in females. Female hormones such as estrogen may play important roles during RCC carcinogenesis and result in significantly different incidence rates between males and females. In this study, we found that estrogen receptor β (ERβ) was more highly expressed in RCC cell lines (A498, RCC-1, 786-O, ACHN, and Caki-1) than in breast cancer cell lines (MCF-7 and HBL-100); however, no androgen receptor (AR) or estrogen receptor α (ERα) could be detected by western blot. In addition, proliferation of RCC cell lines was significantly decreased after estrogen (17-β-estradiol, E2) treatment. Since ERβ had been documented to be a potential tumor suppressor gene, we hypothesized that estrogen activates ERβ tumor suppressive function, which leads to different RCC incidence rates between males and females. We found that estrogen treatment inhibited cell proliferation, migration, invasion, and increased apoptosis of 786-O (high endogenous ERβ), and ERβ siRNA-induced silencing attenuated the estrogen-induced effects. Otherwise, ectopic ERβ expression in A498 (low endogenous ERβ) increased estrogen sensitivity and thus inhibited cell proliferation, migration, invasion, and increased apoptosis. Analysis of the molecular mechanisms revealed that estrogen-activated ERβ not only remarkably reduced growth hormone downstream signaling activation of the AKT, ERK, and JAK signaling pathways but also increased apoptotic cascade activation. In conclusion, this study found that estrogen-activated ERβ acts as a tumor suppressor. It may explain the different RCC incidence rates between males and females. Furthermore, it implies that ERβ may be a useful prognostic marker for RCC progression and a novel developmental direction for RCC treatment improvement.

The causal role of human papillomavirus (HPV) in cervical carcinogenesis is beyond reasonable questioning. The progression from HPV infection, squamous intraepithelial lesions (SIL) to squamous cell carcinomata (SCC), however, is very uncommon and inefficient. Host genetic factors that may confer the susceptibility of disease progression are largely unknown. Apoptosis is an important fail‐safe check for tumor development, in which Fas/FasL interaction contributes substantially. The purpose of our study is to test the hypothesis that an A/G polymorphism at −670 of Fas promoter with different transcriptional activity is associated with the risk for cervical neoplasia. A hospital‐based case‐control study was conducted, in which 104 patients of low grade SIL (LSIL), 131 high grade SIL (HSIL) and 176 SCC as well as age‐matched, 1:1 controls were tested for Fas polymorphism by PCR‐RFLP. HPV genotypes were determined in case groups by MY PCR‐reverse line blot. The frequency of A allele was significantly (p = 0.006) higher in SCC than in control, conferring an odd ratio of 1.5 (95% CI = 1.1–2.0). The distribution of Fas (−670) genotypes also differed significantly between HSIL, SCC and each of their control (p = 0.017 and 0.03, respectively), with the A/A genotype conferring an OR of 1.3 (95% CI = 1.1–1.6) and 1.6 (95% CI = 1.0–2.5), respectively. Remarkably, the frequency of A allele and A/A genotype increased gradually in accordance with the multi‐step carcinogenesis from LSIL, HSIL to SCC (p_{test for trend} = 0.0066 and 0.0007, respectively). In addition, there was no difference of Fas genotypes between HPV (+) and HPV (−) cases. Fas genotypes, however, differed in LSIL infected with different HPV types (p = 0.033). The present study demonstrated an association between Fas polymorphism and cervical carcinogenesis. We deduced a possible effect of apoptosis of immune cells in this virus‐induced cancer.

Adiponectin is a peptide hormone secreted exclusively by adipocytes, and obesity is an established risk factor for breast cancer. We have, thus, evaluated the associations of anthropometric measures of adiposity and adiponectin with the development of breast cancer in a case–control study. Questionnaire information, anthropometric measures, and blood samples were taken before treatment from 244 incident cases with breast cancer, including 141 premenopausal and 103 postmenopausal cases, and 244 controls admitted for health examination at the Tri-Service General Hospital, Taipei between 2004 and 2005. Plasma levels of adiponectin were measured by RIA. The relationship between anthropometric measures of adiposity and breast cancer risk was modified by menopausal status, with a significant increase in risk observed in postmenopausal but not premenopausal women. Moreover, a fairly robust inverse association of adiponectin with the risk was observed only in postmenopausal women (adjusted odds ratio (OR), 0.55; 95% confidence interval (CI), 0.23–0.97), but not in premenopausal women. Additionally, the plasma adiponectin levels tended to be inversely associated with estrogen receptor (ER)-positive (adjusted OR, 0.53; 95% CI, 0.27–0.98) but not ER-negative breast tumors. Furthermore, the associations of adiponectin with breast cancer risk overall and by menopausal and ER status remained after adjustment for obesity indices. These results suggest that adiponectin may have an independent role in breast carcinogenesis, particularly in the postmenopausal and ER-positive breast cancer risk.

MicroRNA-382-5p aggravates breast cancer progression by regulating the RERG/Ras/ERK signaling axis

Renal cell carcinoma (RCC) is a malignancy with poor prognosis. WNT/β-catenin signaling dysregulation, especially β-catenin overactivation and WNT antagonist silencing, is associated with RCC carcinogenesis and progression. However, the role of WNT ligands in RCC has not yet been determined. We screened 19 WNT ligands from normal kidney and RCC cell lines and tissues and found that WNT10A was significantly increased in RCC cell lines and tissues as compared to that in normal controls. The clinical significance of increase in WNT10A was evaluated by performing an immunohistochemical association study in a 19-year follow-up cohort comprising 284 RCC and 267 benign renal disease (BRD) patients. The results of this study showed that WNT10A was dramatically upregulated in RCC tissues as compared to that in BRD tissues. This result suggests that WNT10A, nuclear β-catenin, and nuclear cyclin D1 act as independent risk factors for RCC carcinogenesis and progression, with accumulative risk effects. Molecular validation of cell line models with gain- or loss-of-function designs showed that forced WNT10A expression induced RCC cell proliferation and aggressiveness, including higher chemoresistance, cell migration, invasiveness, and cell transformation, due to the activation of β-catenin-dependent signaling. Conversely, WNT10A siRNA knockdown decreased cell proliferation and aggressiveness of RCC cells. In conclusion, we showed that WNT10A acts as an autocrine oncogene both in RCC carcinogenesis and progression by activating WNT/β-catenin signaling.