miR-877-5p as a Potential Link between Triple-Negative Breast Cancer Development and Metabolic Syndrome.

Metabolic syndrome (MS) is a risk factor for breast cancer (BC) that increases its aggressiveness and metastasis. The prevalence of MS is higher in triple-negative breast cancer (TNBC), which is the molecular subtype with the worst prognosis. The molecular mechanisms underlying this association have not been fully elucidated. MiRNAs are small, non-coding RNAs that regulate gene expression. Aberrant expression of miRNAs in both tissues and fluids are linked to several pathologies. The aim of this work was to identify circulating miRNAs in patients with alterations associated with MS (AAMS) that also impact on BC. Using microarray technology, we detected 23 miRNAs altered in the plasma of women with AAMS that modulate processes linked to cancer. We found that let-7b-5p and miR-28-3p were decreased in plasma from patients with AAMS and also in BC tumors, while miR-877-5p was increased. Interestingly, miR-877-5p expression was associated with lower patient survival, and its expression was higher in PAM50 basal-like BC tumors compared to the other molecular subtypes. Analyses from public databases revealed that miR-877-5p was also increased in plasma from BC patients compared to plasma from healthy donors. We identified IGF2 and TIMP3 as validated target genes of miR-877-5p whose expression was decreased in BC tissue and moreover, was negatively correlated with the levels of this miRNA in the tumors. Finally, a miRNA inhibitor against miR-877-5p diminished viability and tumor growth of the TNBC model 4T1. These results reveal that miR-877-5p inhibition could be a therapeutic option for the treatment of TNBC. Further studies are needed to investigate the role of this miRNA in TNBC progression.

Hsa-miR-133a-3p, miR-1-3p, GOLPH3 and JUP combination results in a good biomarker to distinguish between prostate cancer and non-prostate cancer patients.

The incidence and mortality of Prostate Cancer (PCa) worldwide correlate with age and bad dietary habits. Previously, we investigated the mRNA/miRNA role on PCa development and progression using high fat diet (HFD) fed mice. Here our main goal was to investigate the effect of HFD on the expression of PCa-related miRNAs and their relevance in PCa patients. We identified 6 up- and 18 down-regulated miRNAs in TRAMP-C1 mice prostate tumors under HFD conditions using miRNA microarrays. Three down-regulated miRNAs: mmu-miR-133a-3p, -1a-3p and -29c-3p were validated in TRAMP-C1 mice prostate tumor by stem-loop RT-qPCR. Hsa-miR-133a-3p/1-3p expression levels were significantly decreased in PCa compared to normal tissues while hsa-miR-133a-3p was found to be further decreased in metastatic prostate cancer tumors compared to non-metastatic PCa. We examined the promoter region of hsa-miR-133a-3p/1-3p genes and compared methylation at these loci with mature miRNA expression. We found that hsa-miR-1-2/miR-133a-1 cluster promoter hypermethylation decreased hsa-miR-133a-3p/1-3p expression in PCa. GOLPH3 and JUP, two hsa-miR-133a-3p and miR-1-3p predicted target genes, were up-regulated in PCa. ROC analysis showed that the combination of hsa-miR-133a-3p, miR-1-3p, GOLPH3 and JUP is a promising panel biomarker to distinguish between PCa and normal adjacent tissue (NAT). These results link PCa aggressiveness to the attenuation of hsa-miR-133a-3p and miR-1-3p expression by promoter hypermethylation. Hsa-miR-133a-3p and miR-1-3p down-regulation may enhance PCa aggressiveness in part by targeting GOLPH3 and JUP.

MiR-106b-5p: A Master Regulator of Potential Biomarkers for Breast Cancer Aggressiveness and Prognosis.

Breast cancer (BCa) is the leading cause of death by cancer in women worldwide. This disease is mainly stratified in four subtypes according to the presence of specific receptors, which is important for BCa aggressiveness, progression and prognosis. MicroRNAs (miRNAs) are small non-coding RNAs that have the capability to modulate several genes. Our aim was to identify a miRNA signature deregulated in preclinical and clinical BCa models for potential biomarker discovery that would be useful for BCa diagnosis and/or prognosis. We identified hsa-miR-21-5p and miR-106b-5p as up-regulated and hsa-miR-205-5p and miR-143-3p as down-regulated in BCa compared to normal breast or normal adjacent (NAT) tissues. We established 51 shared target genes between hsa-miR-21-5p and miR-106b-5p, which negatively correlated with the miRNA expression. Furthermore, we assessed the pathways in which these genes were involved and selected 12 that were associated with cancer and metabolism. Additionally, GAB1, GNG12, HBP1, MEF2A, PAFAH1B1, PPP1R3B, RPS6KA3 and SESN1 were downregulated in BCa compared to NAT. Interestingly, hsa-miR-106b-5p was up-regulated, while GAB1, GNG12, HBP1 and SESN1 were downregulated in aggressive subtypes. Finally, patients with high levels of hsa-miR-106b-5 and low levels of the abovementioned genes had worse relapse free survival and worse overall survival, except for GAB1.

MiR-19b-3p and miR-101-3p as potential biomarkers for prostate cancer diagnosis and prognosis.

Prostate cancer (PCa) is the most commonly diagnosed male malignancy worldwide. Early diagnosis and metastases detection are crucial features to diminish patient mortality. High fat diet (HFD) and metabolic syndrome increase PCa risk and aggressiveness. Our goal was to identify miRNAs-based biomarkers for PCa diagnosis and prognosis associated with HFD. Mice chronically fed with a HFD or control diet (CD) were subcutaneously inoculated with androgen insensitive PC3 cells. Xenografts from HFD-fed mice showed increased expression of 7 miRNAs that we named "candidates" compared to CD-fed mice. These miRNAs modulate specific metabolic and cancer related pathways. Using bioinformatic tools and human datasets we found that hsa-miR-19b-3p and miR-101-3p showed more than 1,100 validated targets involved in proteoglycans in cancer and fatty acid biosynthesis. These miRNAs were significantly increased in the bloodstream of PCa patients compared to non-PCa volunteers, and in prostate tumors compared to normal adjacent tissues (NAT). Interestingly, both miRNAs were also increased in tumors of metastatic patients compared to tumors of non-metastatic patients. Further receiver-operating characteristic (ROC) analysis determined that hsa-miR-19b-3p and hsa-miR-101-3p in serum showed poor predictive power to discriminate PCa from non-PCa patients. Hsa-miR-19b-3p showed the best score to discriminate between tumor and NAT, while hsa-miR-101-3p was useful to differentiate between metastatic and non-metastatic PCa patients. Hsa-miR-101-3p was increased in exosomes isolated from blood of PCa patients. Although more detailed functional exploration and validation of the molecular mechanisms are required, we identified hsa-miR-19b-3p and hsa-miR-101-3p with high potential for PCa diagnosis and prognosis.

Adipose tissue from metabolic syndrome mice induces an aberrant miRNA signature highly relevant in prostate cancer development.

Prostate cancer (PCa) remains an important public health concern in Western countries. Metabolic syndrome (MeS) is a cluster of pathophysiological disorders with increasing prevalence in the general population that is a risk factor for PCa. Several studies have determined that a crosstalk between white adipose tissue (WAT) and solid tumors favors cancer aggressiveness. In this work, our main goal was to investigate the interaction between WAT and PCa cells through microRNAs (miRNAs), in MeS mice. We developed a MeS-like disease model using C57BL/6J mice chronically fed with high-fat diet (HFD) that were inoculated with TRAMP-C1 PCa cells. A group of five miRNAs (mmu-miR-221-3p, 27a-3p, 34a-5p, 138-5p, and 146a-5p) were increased in gonadal WAT (gWAT), tumors, and plasma of MeS mice compared to control animals. Three of these five miRNAs were detected in the media from gWAT and TRAMP-C1 cell cocultures, and significantly increased in MeS context. More importantly, hsa-miR-221-3p, 146a-5p, and 27a-3p were increased in bloodstream of PCa patients compared to healthy donors. Using miRNA microarrays, we found that 121 miRNAs were differentially released to the coculture media between HFD-gWAT and tumor cells compared to control diet-gWAT and tumor cells. Target genes for the 66 most deregulated miRNAs were involved in common pathways, mainly related to fatty acid metabolism, ER protein processing, amino acid degradation, PI3K AKT signaling, and PCa. Our findings show for the first time a signature of five miRNAs as important players involved in the interaction between WAT and PCa in MeS mice. Further research will be necessary to track these miRNAs in the interaction between these tissues as well as their role in PCa patients with MeS.

CTBP1 depletion on prostate tumors deregulates miRNA/mRNA expression and impairs cancer progression in metabolic syndrome mice.

About 20% of prostate cancer (PCa) patients progress to metastatic disease. Metabolic syndrome (MeS) is a pathophysiological disorder that increases PCa risk and aggressiveness. C-terminal binding protein (CTBP1) is a transcriptional corepressor that is activated by high-fat diet (HFD). Previously, our group established a MeS/PCa mice model that identified CTBP1 as a novel link associating both diseases. Here, we integrated in vitro (prostate tumor cell lines) and in vivo (MeS/PCa NSG mice) models with molecular and cell biology techniques to investigate MeS/CTBP1 impact over PCa progression, particularly over cell adhesion, mRNA/miRNA expression and PCa spontaneous metastasis development. We found that CTBP1/MeS regulated expression of genes relevant to cell adhesion and PCa progression, such as cadherins, integrins, connexins, and miRNAs in PC3 xenografts. CTBP1 diminished PCa cell adhesion, membrane attachment to substrate and increased filopodia number by modulating gene expression to favor a mesenchymal phenotype. NSG mice fed with HFD and inoculated with CTBP1-depleted PC3 cells, showed a decreased number and size of lung metastases compared to control. Finally, CTBP1 and HFD reduce hsa-mir-30b-5p plasma levels in mice. This study uncovers for the first time the role of CTBP1/MeS in PCa progression and its molecular targets.

CTBP1 and metabolic syndrome induce an mRNA and miRNA expression profile critical for breast cancer progression and metastasis.

Metastatic breast cancer (BrCa) is still one of the main causes of cancer death in women. Metabolic syndrome (MeS), a risk factor for BrCa, is associated to high grade tumors, increased metastasis and recurrence of this disease. C-terminal binding protein 1 (CTBP1) is a co-repressor of tumor suppressor genes that is activated by low NAD+/NADH ratio. Previously, we demonstrated that CTBP1 hyperactivation by MeS increased tumor growth in MDA-MB-231-derived xenografts regulating several genes and miRNAs. In this work, our aim was to elucidate the role of CTBP1 and MeS in BrCa metastasis. We found that CTBP1 protein diminished adhesion while increased migration of triple negative BrCa cells. CTBP1 and MeS modulated the expression of multiple genes (ITGB4, ITGB6, PRSS2, COL17A1 and FABP4) and miRNAs (miR-378a-3p, miR-146a-5p, let-7e-3p, miR-381-5p, miR-194-5p, miR-494-3p) involved in BrCa progression of MDA-MB-231-derived xenografts. Furthermore, we demonstrated that MeS increased lung micrometastasis and liver neoplastic disease in mice. CTBP1 hyperactivation seems to be critical for MeS effect on BrCa metastasis since CTBP1 depletion completely impaired the detection of circulating tumor cells. Our results highlight CTBP1 and MeS impact on BrCa progression positioning them as key properties to be considered for BrCa patient prognosis and management.