Overexpression of CLDN16 in ovarian cancer is modulated by PI3K and PKC pathways.

Epithelial ovarian cancer (EOC) is the gynecological malignant tumor of poorest prognosis and higher mortality rate. Chemotherapy is the base of high-grade serous ovarian cancer (HGSOC) treatment; however, it favors the emergence of chemoresistance and metastasis. Thus, there is an urge to search for new therapeutic targets, such as proteins related to cellular proliferation and invasion. Herein, we investigated the expression profile of claudin-16 (CLDN16 protein and CLDN16 transcript) and its possible functions in EOC. In silico analysis of CLDN16 expression profile was performed using data extracted from GENT2 and GEPIA2 platforms. A retrospective study was carried out with 55 patients to evaluate the expression of CLDN16. The samples were evaluated by immunohistochemistry, immunofluorescence, qRT-PCR, molecular docking, sequencing, and immunoblotting assays. Statistical analyzes were performed using Kaplan-Meier curves, one-way ANOVA, Turkey posttest. Data were analyzed using GraphPad Prism 8.0. In silico experiments showed that CLDN16 is overexpressed in EOC. 80.0% of all EOC types overexpressed CLDN16, of which in 87% of the cases the protein is restricted to cellular cytoplasm. CLDN16 expression was not related to tumor stage, tumor cells differentiation status, tumor responsiveness to cisplatin, or patients' survival rate. When compared to data obtained from in silico analysis regarding EOC stage and degree of differentiation, differences were found in the former but not in the later, neither in survival curves. CLDN16 expression in HGSOC OVCAR-3 cells increased by 1.95-fold (p < 0.001), 2.32-fold (p < 0.001), and 6.57-fold (p < 0.001) via PKC, PI3K, and estrogen pathways, respectively. Altogether, our results suggest that despite the low number of samples included in our in vitro studies, adding to the expression profile findings, we provided a comprehensive study of CLDN16 expression in EOC. Therefore, we hypothesize that CLDN16 is a potential target in the diagnosis and treatment of the disease.

Prevalence of estrogen receptor alpha PvuII (c454-397T>C) and XbaI (c454A>G) polymorphisms in a population of Brazilian women

The aim of this work was to study the estrogen receptor alpha (ERS1) PvuII and XbaI gene polymorphisms prevalence in randomly selected women population from Rio de Janeiro and Espírito Santo states in Brazil by polymerase chain reaction restriction fragment lengths polymorphism (PCR_RFLP) methodology. It was shown that Rio de Janeiro women exhibited a significantly different prevalence of XbaI polymorphism comparing to Espirito Santo women. Nonetheless, similar prevalence of PvuII polymorphism was found in both women´s populations. Moreover, a strong linkage disequilibrium was observed between these SNPs reinforcing the hypothesis of differential pattern of inheritance observed on such populations.

Evaluation of PvuII and XbaI polymorphisms in the estrogen receptor alpha gene (ESR1) in relation to menstrual cycle timing and reproductive parameters in post-menopausal women.

OBJECTIVE: To evaluate the association of -397T>C and -351A>G single nucleotide polymorphisms (SNPs) - also called PvuII and XbaI, respectively - located on estrogen receptor alpha (ERS1) gene with age at menarche, menopause onset, fertility and miscarriage in a population of post-menopausal women. STUDY DESIGN: Cross-sectional study with 273 healthy, high miscegenated, post-menopausal women (mean age of 63.1±9.7 years old). Subjects were genotyped for PvuII and XbaI SNPs by PCR-RFLP and confirmed by automatic sequencing. Reproduction informations (age at menarche, age at menopause, number of pregnancies, fertility rate and miscarriages) were obtained by retrospective study using a questionnaire. RESULT(S): Age at menarche, menopause onset, number of pregnancies, total fertility rate, and parity did not seem to be influenced by any of the studied genotypes (chi-square, p>0.05). However, women carrying the xx genotype showed a 44% higher chance of miscarriage, whereas this value did not trespass 16% for any other genotype analyzed. It has been also observed a higher occurrence of miscarriage in association with combined xxpp genotype of ERS1 gene (chi-square, p<0.01). CONCLUSION(S): The present data indicate that the studied SNPs on ERS1 gene do not influence the menstrual cycle timing and parity but there is a strong relationship between the xx ERS1 SNP genotype and the incidence of miscarriage in the post-menopausal population analyzed.

The Cotransporter NaPi-IIb: characteristics, regulation and its role in carcinogenesis

Inorganic phosphate (Pi) presents a crucial role in cellular metabolism, with the kidney and intestine as the principal regulating organs of the homeostasis of this nutrient. Maintaining phosphate balance results from the activity of different subtype of transporters of sodium-dependent phosphate that use the electrochemical gradient of sodium ions to carry out cotransport. Several diseases have been related to dysfunctions of phosphate cotransporters, including in the area of oncology. A study using the SAGE technique pointed to a possible role of the type IIb sodium-phosphate cotransporter (NaPi-IIb), encoded by the SLC34A2 gene, in ovarian carcinogenesis. More recently, such protein was associated with the development of other carcinomas and some of the components that regulate its function were determined. It is believed that in the future, the analysis of SLC34A2 expression in tumor samples will help in the choice of treatment, evaluation of prognosis and be a possible target for new therapeutic strategies.