Progesterone receptor isoform ratio dictates antiprogestin/progestin effects on breast cancer growth and metastases: A role for NDRG1.

Progesterone receptors (PRs) ligands are being tested in luminal breast cancer. There are mainly two PR isoforms, PRA and PRB, and their ratio (PRA/PRB) may be predictive of antiprogestin response. Our aim was to investigate: the impact of the PR isoform ratio on metastatic behaviour, the PR isoform ratio in paired primary tumours and lymph node metastases (LNM) and, the effect of antiprogestin/progestins on metastatic growth. Using murine and human metastatic models, we demonstrated that tumours with PRB > PRA (PRB-H) have a higher proliferation index but less metastatic ability than those with PRA > PRB (PRA-H). Antiprogestins and progestins inhibited metastatic burden in PRA-H and PRB-H models, respectively. In breast cancer samples, LNM retained the same PRA/PRB ratio as their matched primary tumours. Moreover, PRA-H LNM expressed higher total PR levels than the primary tumours. The expression of NDRG1, a metastasis suppressor protein, was higher in PRB-H compared to PRA-H tumours and was inversely regulated by antiprogestins/progestins. The binding of the corepressor SMRT at the progesterone responsive elements of the NDRG1 regulatory sequences, together with PRA, impeded its expression in PRA-H cells. Antiprogestins modulate the interplay between SMRT and AIB1 recruitment in PRA-H or PRB-H contexts regulating NDRG1 expression and thus, metastasis. In conclusion, we provide a mechanistic interpretation to explain the differential role of PR isoforms in metastatic growth and highlight the therapeutic benefit of using antiprogestins in PRA-H tumours. The therapeutic effect of progestins in PRB-H tumours is suggested.

Gonadal Degeneration Is Mediated by Apoptotic Processes in the Semelparous Gray Side-Gilled Sea Slug Pleurobranchaea maculata.

AbstractSpecies undergoing postreproductive death experience great changes in their reproductive organs, which are driven by numerous physiological processes. To assess whether apoptotic processes are involved in the dynamics of the reproductive organs of Pleurobranchaea maculata, the gonadal structure of this semelparous side-gilled sea slug was studied using light and scanning electron microscopy. Apoptotic cells at different gonadal developmental stages were detected by in situ TUNEL assay. Apoptosis was primarily focused on spermatogonia during gonadal cell proliferation, probably as a regulatory mechanism that maintains homeostasis in reproductive cells. Visible gonadal degeneration at the end of the reproductive period is accompanied by apoptosis of the basal lamina cells of the acini, suggesting that apoptotic processes are involved in the gonadal degeneration observed in P. maculata.

E-cadherin: A determinant molecule associated with ovarian cancer progression, dissemination and aggressiveness.

Ovarian cancer (OC) is the fifth cancer death cause in women worldwide. The malignant nature of this disease stems from its unique dissemination pattern. Epithelial-to-mesenchymal transition (EMT) has been reported in OC and downregulation of Epithelial cadherin (E-cadherin) is a hallmark of this process. However, findings on the relationship between E-cadherin levels and OC progression, dissemination and aggressiveness are controversial. In this study, the evaluation of E-cadherin expression in an OC tissue microarray revealed its prognostic value to discriminate between advanced- and early-stage tumors, as well as serous tumors from other histologies. Moreover, E-cadherin, Neural cadherin (N-cadherin), cytokeratins and vimentin expression was assessed in TOV-112, SKOV-3, OAW-42 and OV-90 OC cell lines grown in monolayers and under anchorage-independent conditions to mimic ovarian tumor cell dissemination, and results were associated with cell aggressiveness. According to these EMT-related markers, cell lines were classified as mesenchymal (M; TOV-112), intermediate mesenchymal (IM; SKOV-3), intermediate epithelial (IE; OAW-42) and epithelial (E; OV-90). M- and IM-cells depicted the highest migration capacity when grown in monolayers, and aggregates derived from M- and IM-cell lines showed lower cell death, higher adhesion to extracellular matrices and higher invasion capacity than E- and IE-aggregates. The analysis of E-cadherin, N-cadherin, cytokeratin 19 and vimentin mRNA levels in 20 advanced-stage high-grade serous human OC ascites showed an IM phenotype in all cases, characterized by higher proportions of N- to E-cadherin and vimentin to cytokeratin 19. In particular, higher E-cadherin mRNA levels were associated with cancer antigen 125 levels more than 500 U/mL and platinum-free intervals less than 6 months. Altogether, E-cadherin expression levels were found relevant for the assessment of OC progression and aggressiveness.

CDH1/E-cadherin and solid tumors. An updated gene-disease association analysis using bioinformatics tools.

Cancer is a group of diseases that causes millions of deaths worldwide. Among cancers, Solid Tumors (ST) stand-out due to their high incidence and mortality rates. Disruption of cell-cell adhesion is highly relevant during tumor progression. Epithelial-cadherin (protein: E-cadherin, gene: CDH1) is a key molecule in cell-cell adhesion and an abnormal expression or/and function(s) contributes to tumor progression and is altered in ST. A systematic study was carried out to gather and summarize current knowledge on CDH1/E-cadherin and ST using bioinformatics resources. The DisGeNET database was exploited to survey CDH1-associated diseases. Reported mutations in specific ST were obtained by interrogating COSMIC and IntOGen tools. CDH1 Single Nucleotide Polymorphisms (SNP) were retrieved from the dbSNP database. DisGeNET analysis identified 609 genes annotated to ST, among which CDH1 was listed. Using CDH1 as query term, 26 disease concepts were found, 21 of which were neoplasms-related terms. Using DisGeNET ALL Databases, 172 disease concepts were identified. Of those, 80 ST disease-related terms were subjected to manual curation and 75/80 (93.75%) associations were validated. On selected ST, 489 CDH1 somatic mutations were listed in COSMIC and IntOGen databases. Breast neoplasms had the highest CDH1-mutation rate. CDH1 was positioned among the 20 genes with highest mutation frequency and was confirmed as driver gene in breast cancer. Over 14,000 SNP for CDH1 were found in the dbSNP database. This report used DisGeNET to gather/compile current knowledge on gene-disease association for CDH1/E-cadherin and ST; data curation expanded the number of terms that relate them. An updated list of CDH1 somatic mutations was obtained with COSMIC and IntOGen databases and of SNP from dbSNP. This information can be used to further understand the role of CDH1/E-cadherin in health and disease.