LRP10, PGK1 and RPLP0: Best Reference Genes in Periprostatic Adipose Tissue under Obesity and Prostate Cancer Conditions.

Obesity (OB) is a metabolic disorder characterized by adipose tissue dysfunction that has emerged as a health problem of epidemic proportions in recent decades. OB is associated with multiple comorbidities, including some types of cancers. Specifically, prostate cancer (PCa) has been postulated as one of the tumors that could have a causal relationship with OB. Particularly, a specialized adipose tissue (AT) depot known as periprostatic adipose tissue (PPAT) has gained increasing attention over the last few years as it could be a key player in the pathophysiological interaction between PCa and OB. However, to date, no studies have defined the most appropriate internal reference genes (IRGs) to be used in gene expression studies in this AT depot. In this work, two independent cohorts of PPAT samples (n = 20/n = 48) were used to assess the validity of a battery of 15 literature-selected IRGs using two widely used techniques (reverse transcription quantitative PCR [RT-qPCR] and microfluidic-based qPCR array). For this purpose, ΔCt method, GeNorm (v3.5), BestKeeper (v1.0), NormFinder (v.20.0), and RefFinder software were employed to assess the overall trends of our analyses. LRP10, PGK1, and RPLP0 were identified as the best IRGs to be used for gene expression studies in human PPATs, specifically when considering PCa and OB conditions.

Somatostatin, Cortistatin and Their Receptors Exert Antitumor Actions in Androgen-Independent Prostate Cancer Cells: Critical Role of Endogenous Cortistatin.

Somatostatin (SST), cortistatin (CORT), and their receptors (SSTR1-5/sst5TMD4-TMD5) comprise a multifactorial hormonal system involved in the regulation of numerous pathophysiological processes. Certain components of this system are dysregulated and play critical roles in the development/progression of different endocrine-related cancers. However, the presence and therapeutic role of this regulatory system in prostate cancer (PCa) remain poorly explored. Accordingly, we performed functional (proliferation/migration/colonies-formation) and mechanistic (Western-blot/qPCR/microfluidic-based qPCR-array) assays in response to SST and CORT treatments and CORT-silencing (using specific siRNA) in different PCa cell models [androgen-dependent (AD): LNCaP; androgen-independent (AI)/castration-resistant PCa (CRPC): 22Rv1 and PC-3], and/or in the normal-like prostate cell-line RWPE-1. Moreover, the expression of SST/CORT system components was analyzed in PCa samples from two different patient cohorts [internal (n = 69); external (Grasso, n = 88)]. SST and CORT treatment inhibited key functional/aggressiveness parameters only in AI-PCa cells. Mechanistically, antitumor capacity of SST/CORT was associated with the modulation of oncogenic signaling pathways (AKT/JNK), and with the significant down-regulation of critical genes involved in proliferation/migration and PCa-aggressiveness (e.g., MKI67/MMP9/EGF). Interestingly, CORT was highly expressed, while SST was not detected, in all prostate cell-lines analyzed. Consistently, endogenous CORT was overexpressed in PCa samples (compared with benign-prostatic-hyperplasia) and correlated with key clinical (i.e., metastasis) and molecular (i.e., SSTR2/SSTR5 expression) parameters. Remarkably, CORT-silencing drastically enhanced proliferation rate and blunted the antitumor activity of SST-analogues (octreotide/pasireotide) in AI-PCa cells. Altogether, we provide evidence that SST/CORT system and SST-analogues could represent a potential therapeutic option for PCa, especially for CRPC, and that endogenous CORT could act as an autocrine/paracrine regulator of PCa progression.

Dysregulation of RNA-Exosome machinery is directly linked to major cancer hallmarks in prostate cancer: Oncogenic role of PABPN1.

Novel biomarkers and therapeutic strategies for prostate-cancer (PCa) are required to overcome its lethal progression. The dysregulation/implication of the RNA-Exosome-complex (REC; cellular machinery controlling the 3'-5'processing/degradation of most RNAs) in different cancer-types, including PCa, is poorly known. Herein, different cellular/molecular/preclinical approaches with human PCa-samples (tissues and/or plasma of 7 independent cohorts), and in-vitro/in-vivo PCa-models were used to comprehensively characterize the REC-profile and explore its role in PCa. Moreover, isoginkgetin (REC-inhibitor) effects were evaluated on PCa-cells. We demonstrated a specific dysregulation of the REC-components in PCa-tissues, identifying the Poly(A)-Binding-Protein-Nuclear 1 (PABPN1) factor as a critical regulator of major cancer hallmarks. PABPN1 is consistently overexpressed in different human PCa-cohorts and associated with poor-progression, invasion and metastasis. PABPN1 silencing decreased relevant cancer hallmarks in multiple PCa-models (proliferation/migration/tumourspheres/colonies, etc.) through the modulation of key cancer-related lncRNAs (PCA3/FALEC/DLEU2) and mRNAs (CDK2/CDK6/CDKN1A). Plasma PABPN1 levels were altered in patients with metastatic and tumour-relapse. Finally, pharmacological inhibition of REC-activity drastically inhibited PCa-cell aggressiveness. Altogether, the REC is drastically dysregulated in PCa, wherein this novel molecular event/mechanism, especially PABPN1 alteration, may be potentially exploited as a novel prognostic and therapeutic tool for PCa.

SRSF6 modulates histone-chaperone HIRA splicing to orchestrate AR and E2F activity in prostate cancer.

Despite novel therapeutic strategies, advanced-stage prostate cancer (PCa) remains highly lethal, pointing out the urgent need for effective therapeutic strategies. While dysregulation of the splicing process is considered a cancer hallmark, the role of certain splicing factors remains unknown in PCa. This study focuses on characterizing the levels and role of SRSF6 in this disease. Comprehensive analyses of SRSF6 alterations (copy number/mRNA/protein) were conducted across eight well-characterized PCa cohorts and the Hi-MYC transgenic model. SRSF6 was up-regulated in PCa samples, correlating with adverse clinical parameters. Functional assays, both in vitro (cell proliferation, migration, colony, and tumorsphere formation) and in vivo (xenograft tumors), demonstrated the impact of SRSF6 modulation on critical cancer hallmarks. Mechanistically, SRSF6 regulates the splicing pattern of the histone-chaperone HIRA, consequently affecting the activity of H3.3 in PCa and breast cancer cell models and disrupting pivotal oncogenic pathways (AR and E2F) in PCa cells. These findings underscore SRSF6 as a promising therapeutic target for PCa/advanced-stage PCa.

Dysregulation of the miRNome unveils a crosstalk between obesity and prostate cancer: miR-107 asa personalized diagnostic and therapeutic tool.

Prostate-specific antigen (PSA) is the gold-standard marker to screen prostate cancer (PCa) nowadays. Unfortunately, its lack of specificity and sensitivity makes the identification of novel tools to diagnose PCa an urgent medical need. In this context, microRNAs (miRNAs) have emerged as potential sources of non-invasive diagnostic biomarkers in several pathologies. Therefore, this study was aimed at assessing for the first time the dysregulation of the whole plasma miRNome in PCa patients and its putative implication in PCa from a personalized perspective (i.e., obesity condition). Plasma miRNome from a discovery cohort (18 controls and 19 PCa patients) was determined using an Affymetrix-miRNA array, showing that the expression of 104 miRNAs was significantly altered, wherein six exhibited a significant receiver operating characteristic (ROC) curve to distinguish between control and PCa patients (area under the curve [AUC] = 1). Then, a systematic validation using an independent cohort (135 controls and 160 PCa patients) demonstrated that miR-107 was the most profoundly altered miRNA in PCa (AUC = 0.75). Moreover, miR-107 levels significantly outperformed the ability of PSA to distinguish between control and PCa patients and correlated with relevant clinical parameters (i.e., PSA). These differences were more pronounced when considering only obese patients (BMI > 30). Interestingly, miR-107 levels were reduced in PCa tissues versus non-tumor tissues (n = 84) and in PCa cell lines versus non-tumor cells. In vitro miR-107 overexpression altered key aggressiveness features in PCa cells (i.e., proliferation, migration, and tumorospheres formation) and modulated the expression of important genes involved in PCa pathophysiology (i.e., lipid metabolism [i.e., FASN] and splicing process). Altogether, miR-107 might represent a novel and useful personalized diagnostic and prognostic biomarker and a potential therapeutic tool in PCa, especially in obese patients.