H19-Dependent Transcriptional Regulation of β3 and β4 Integrins Upon Estrogen and Hypoxia Favors Metastatic Potential in Prostate Cancer

Abstract

Estrogen and hypoxia promote an aggressive phenotype in prostate cancer (PCa), driving transcription of progression-associated genes. Here, we molecularly dissect the contribution of long non-coding RNA H19 to PCa metastatic potential under combined stimuli, a topic largely uncovered. The effects of estrogen and hypoxia on H19 and cell adhesion molecules’ expression were investigated in PCa cells and PCa-derived organotypic slice cultures (OSCs) by qPCR and Western blot. The molecular mechanism was addressed by chromatin immunoprecipitations, overexpression, and silencing assays. PCa cells’ metastatic potential was analyzed by in vitro cell-cell adhesion, motility test, and trans-well invasion assay. We found that combined treatment caused a significant H19 down-regulation as compared with hypoxia. In turn, H19 acts as a transcriptional repressor of cell adhesion molecules, as revealed by up-regulation of both β3 and β4 integrins and E-cadherin upon H19 silencing or combined treatment. Importantly, H19 down-regulation and β integrins induction were also observed in treated OSCs. Combined treatment increased both cell motility and invasion of PCa cells. Lastly, reduction of β integrins and invasion was achieved through epigenetic modulation of H19-dependent transcription. Our study revealed that estrogen and hypoxia transcriptionally regulate, via H19, cell adhesion molecules redirecting metastatic dissemination from EMT to a β integrin-mediated invasion.

Metabolic Reprogramming by Malat1 Depletion in Prostate Cancer

“…During the progress of this study, we developed an ex vivo human prostate cancer model based on organotypic slice cultures (OSCs). OSCs recapitulate the distinctive characteristics of the tissue of origin (including androgen/estrogen responsiveness of known targets such as PSA or pS2) with the advantage that can be cultured and genetically manipulated, representing a unique source of relevant translational information at a single patient level [ 37 , 38 ] to investigate PCa biology ( Figure 8 A). We collected a series of OSCs obtained from a cohort of 50 PCa patients diagnosed with localized disease and undergoing surgery ( Table 1 ).…”

“…The OSCs in which parameters such as morphology, immunophenotype, and hormone responsiveness were not appropriate [ 37 , 38 ] or the amount of tumor tissue was ≤60%, as estimated by the pathologist on the original histopathological slide, were excluded from the study. Of the remaining 40, qPCR’s MALAT1 basal levels presented a broad distribution ( Figure S8A ), and transfection with MALAT1 gapmer resulted in a significant depletion of MALAT1 in 17 out of 40 ( Figure 8 B and Figure S8B ).…”

“…CHKA 5'-GGTCACTTGGGCCAAAACTC-3' and 5 -GCCGGCTCGGGATGA-3'; CS 5 -GGGTGCTGCTCCAGTATTATGG-3 and 5 -GCTCGTGACACCCCAAACA-3 . Primers specific to MALAT1, pS2, PSA, hTERT, GAPDH, and β-actin were as in [37]; those for CDH1 as in [38], those for tRNA-LeutRNA-Arg as in [60].…”

“…Antibodies: Antibody to E-cadherin, vimentin, fibrillarin, and HIF1α were as described in [ 38 ]. Antibody to androgen receptor as in [ 37 ].…”

Impact of H19 Polymorphisms on Prostate Cancer Clinicopathologic Characteristics

“…LncRNA H19, which is located in 11p15.5, is upregulated in various human solid tumors, including bladder cancer, non–small cell lung cancer, breast cancer, and gastric cancer [ 24 , 25 , 26 ]. Although evidence suggests that H19 functions as an oncogene, its expression and regulatory mechanism in prostate cancer remain controversial [ 27 , 28 , 29 ]. Single-nucleotide polymorphisms (SNPs) in the H19 gene are associated with cancer susceptibilities and clinicopathologic features [ 30 , 31 , 32 , 33 , 34 ].…”