Lixin Hua

A functional polymorphism in Pre-miR-146a gene is associated with prostate cancer risk and mature miR-146a expression in vivo.

A G > C polymorphism (rs2910164) which is located in the sequence of miR‐146a precursor, results in a change from a G:U pair to a C:U mismatch in its stem region. To explore whether rs2910164 plays any role in prostate cancer (CaP), we analyzed the association between miR‐146a polymorphism and risk of CaP and the expression of miR‐146a with different genotypes in CaP tissues in southern Chinese Han population.

A functional polymorphism in MSMB gene promoter is associated with prostate cancer risk and serum MSMB expression.

To explore the reported association of SNP marker rs10993994 with prostate cancer identified by two independent in two genome‐wide association studies (GWAS) further, we performed a case–control study in southern Chinese Han population. Consequently, we detected the serum levels of MSMB expression with different genotypes in the cases and controls to characterize the functional consequences of rs10993994.

MiR-146a suppresses tumor growth and progression by targeting EGFR pathway and in a p-ERK-dependent manner in castration-resistant prostate cancer†‡

Castration‐resistant prostate cancer (CRPC) is a leading cause of cancer‐related deaths in elder men. This disease has limited therapeutic options and poor prognosis as the underlying molecular mechanisms are not clearly understood. Given the emerging roles of microRNA (miRNA) as a key regulator, we postulated that miRNA may play a significant role in CRPC formation.

miR-152 controls migration and invasive potential by targeting TGFα in prostate cancer cell lines†

MicroRNAs (miRNAs) are a class of short non‐coding RNAs that function in diverse biological processes. Aberrant miR‐152 expression has been frequently reported in various malignant tumors. However, the mechanism of miR‐152 in prostate cancer (PCa) remains unclear. This study aims to determine the function of miR‐152 in PCa cells and identify the novel molecular targets regulated by miR‐152.

miR-154 inhibits EMT by targeting HMGA2 in prostate cancer cells.

Epithelial–mesenchymal transition (EMT) is a crucial process that plays an important role in the invasion and metastasis of human cancers. High-mobility group AT-hook 2 (HMGA2) has been found to be involved in the EMT program, with its aberrant expression having been observed in a variety of malignant tumors. However, the mechanisms regulating HMGA2 expression remain incompletely understood. The objective of this study was to investigate whether mir-154 plays a critical role in EMT by regulating HMGA2. The expression levels of HMGA2 were examined in four samples of prostate cancer (PCa) tissue and adjacent non-tumorous tissue by Western blot analysis. The effects of forced expression of miR-154 or HMGA2 knockdown on PCa cells were evaluated by cell migration and invasion assays and Western blot analysis. HMGA2 was upregulated in the PCa tissue samples compared with the adjacent normal ones. Forced expression of miR-154 or HMGA2 knockdown significantly reduced the migratory and invasive capabilities of PCa cells in vitro and inhibited EMT gene expression, increased the levels of E-cadherin, an epithelial marker, and decreased the levels of vimentin, a mesenchymal marker. HMGA2 is a direct target gene of miR-154 by dual-luciferase reporter assay. Our findings suggest that miR-154 plays a role in regulating EMT by targeting HMGA2. Understanding the targets and regulating pathways of miR-154 may provide new insights into the underlying pathogenesis of PCa.

miR-205 is frequently downregulated in prostate cancer and acts as a tumor suppressor by inhibiting tumor growth

The purpose of this study was to elucidate the molecular mechanisms of microRNA-205 (miR-205) as a tumor suppressor in prostate cancer (PCa). In the present study, microRNA microarray analysis suggested that the expression of miR-205 was significantly decreased in advanced PCa compared with early PCa. Real-time PCR analysis also indicated that miR-205 expression was significantly decreased in PCa tissues compared with non-cancerous tissues. Moreover, the expression of miR-205 has been demonstrated to be associated with the clinicopathological stage and total/free prostate-specific antigen (PSA) level of PCa. Functional analyses showed that both the overexpression of miR-205 and the knockdown of c-SRC in PCa cell lines could inhibit cell growth, colony formation, migration, invasion and the cell cycle as well as induce cell apoptosis in vitro. Furthermore, over-expressing miR-205 reduced tumorigenicity in vivo. Through a luciferase activity assay and Western blotting, c-SRC was identified as a target of miR-205 in cells. The overexpression of miR-205 suppressed c-SRC and its downstream signaling molecules, including FAK, p-FAK, ERK1/2 and p-ERK1/2, and attenuated cell proliferation, invasion and tumor growth.

Fenofibrate down-regulates the expressions of androgen receptor (AR) and AR target genes and induces oxidative stress in the prostate cancer cell line LNCaP

Fenofibrate, a peroxisome proliferator-androgen receptor-alpha agonist, is widely used in treating different forms of hyperlipidemia and hypercholesterolemia. Recent reports have indicated that fenofibrate exerts anti-proliferative and pro-apoptotic properties. This study aims to investigate the effects of fenofibrate on the prostate cancer (PCa) cell line LNCaP. The effects of fenofibrate on LNCaP cells were evaluated by flow cytometry, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assays, Western blot analysis, and dual-luciferase reporter assay. Fenofibrate induces cell cycle arrest in G1 phase and apoptosis in LNCaP cells, reduces the expressions of androgen receptor (AR) and AR target genes (prostate-specific antigen and TMPRSS2), and inhibits Akt phosphorylation. Fenofibrate can induce the accumulation of intracellular reactive oxygen species and malondialdehyde, and decrease the activities of total anti-oxidant and superoxide dismutase in LNCaP cells. Fenofibrate exerts an anti-proliferative property by inhibiting the expression of AR and induces apoptosis by causing oxidative stress. Therefore, our data suggest fenofibrate may have beneficial effects in fenofibrate users by preventing prostate cancer growth through inhibition of androgen activation and expression.

The association between MIF-173 G>C polymorphism and prostate cancer in southern Chinese

Accumulating epidemiological and molecular evidence suggests that inflammation is an important component in the etiology of PCa. Macrophage migration inhibitory factor (MIF) plays an important role in the pro‐ and anti‐inflammatory response to infection. This study is aimed at investigating the potential association between MIF‐173 G>C polymorphism, Gleason score, clinical stage, and prostate‐specific antigen (PSA) value with respect to PCa incidence among the Han nationality in Southern China.

miRNA-154-5p Inhibits Proliferation, Migration and Invasion by Targeting E2F5 in Prostate Cancer Cell Lines.

Background: MicroRNAs (miRNAs) are a class of small non-coding RNAs (18-25 nucleotides) which post-transcriptionally regulate gene expression by negatively regulating the stability or translational efficiency of their target mRNAs. This study aimed to determine the function of miR-154-5p in prostate cancer (PCa) cells and identify the novel molecular targets regulated by miR-154-5p. Materials and Methods: The effects of forced miR-154-5p expression or E2F transcription factor 5 (E2F5) knockdown on PCa cells were evaluated by cell proliferation, flow cytometry, cell migration and invasion assays as well as by Western blot analysis. Dual-luciferase reporter assay was performed to verify the precise target of miR-154-5p. Results: The forced expression of miR-154-5p or E2F5 knockdown significantly restrained cell growth, as well as the migratory and invasive capabilities. Such expression also induced G1 cell cycle arrest of PCa cells in vitro. Hence, E2F5 is a direct target gene of miR-154-5p. Conclusions: miR-154-5p may play an important role as an inhibitor of proliferation, migration and invasion of PCa by targeting E2F5 in PCa cell lines.

Genetic Polymorphisms in IGF-I and IGFBP-3 Are Associated with Prostate Cancer in the Chinese Population

Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) are members of the insulin-like growth factor (IGF) family that play important roles in carcinogenesis. We hypothesized that the functional polymorphisms in IGF-I and IGFBP-3 may be associated with the risk of prostate cancer (PCa) in the Chinese population. This hospital-based case-control study included 664 PCa patients and 702 cancer-free controls. Nine SNPs in IGF-I and IGFBP-3 were genotyped using the TaqMan assay. The genetic associations between the pathogenesis and progression of PCa were assessed by logistic regression. We found that the genotype and allele frequency distribution of rs6218, rs35767 and rs5742612 were significantly different when comparing PCa cases to controls (P  = 0.005, 0.005 and 0.020, respectively). In the combined analysis, individuals with 2–6 risk alleles had an elevated risk of PCa compared to those with 0–1 risk alleles. We also found that the association between the combined risk alleles and the risk of PCa appeared stronger in the following subgroups: individuals older than 71 years of age (OR  = 1.41, 95%CI  = 1.05–1.91, P  = 0.020), nonsmokers (OR  = 1.68, 95%CI  = 1.21–2.32, P  = 0.002), nondrinkers (OR  = 1.32, 95%CI  = 1.02–1.61, P  = 0.002), and those with a negative family history of PCa (OR  = 1.28, 95%CI  = 1.02–1.71, P  = 0.022). Our results indicate that the three SNPs (rs6218, rs35767 and rs5742612) and the joint genotypes with 2–6 risk alleles, may contribute to the susceptibility to PCa, but not the progression, in the Chinese population.