NRAL mediates cisplatin resistance in hepatocellular carcinoma via miR-340-5p/Nrf2 axis.

Recent studies have shown that long non-coding RNAs (lncRNAs) play a pivotal role in the pathogenesis and progression of hepatocellular carcinoma (HCC). However, the biological action and potential mechanism of liver cancer cell drug resistance have not been clearly clarified. In this study, lncRNAs were screened and differentially expressed in parental and cisplatin-resistant cell lines (HepG2 and HepG2/CDDP). A novel lncRNA, termed NRAL (Nrf2 regulation-associated lncRNA), was identified, and the initial results indicated that it was highly expressed in HepG2 cisplatin resistant cell lines compared to their parental counterparts. Functionally, NRAL depletion significantly enhanced CDDP-mediated cytotoxicity and apoptosis in two cisplatin-resistant HCC cell lines. Mechanistically, the results indicated that NRAL regulates Nrf2 expression through miR-340-5p serving as a competing endogenous RNA (ceRNA), thus influencing the CDDP-induced phenotype in HCC. Collectively, the present investigation suggest that the NRAL/miR-340-5p/Nrf2 axis mediates cisplatin resistance in HCC, which may provide novel targets for overcoming cisplatin resistance in hepatocellular carcinoma cells.

Estrogen receptor alpha gene polymorphisms and breast cancer risk: a case-control study with meta-analysis combined.

Molecular epidemiological studies have shown that gene polymorphisms of estrogen receptor alpha gene (ESR-α) are associated with breast cancer risk. However, previous results from many molecular studies have been inconsistent. In this study, we examined two polymorphisms (PvuII and XbaI RFLPs) of the ESR-α gene in 542 breast cancer cases and 1,016 controls from China. Associations between the polymorphisms and breast cancer risk were calculated with an unconditional logistic regression model. Linkage disequilibrium and haplotypes were analyzed with the SHEsis software. In addition, we also performed a systematic meta-analysis of 24 published studies evaluating the association. No significant associations were found between the PvuII polymorphism and breast cancer risk. However, a significantly decreased risk of breast cancer was observed among carriers of the XbaI 'G' allele (age-adjusted OR = 0.80; 95% CI = 0.66- 0.97) compared with carriers of the 'A' allele. Haplotype analysis showed significantly decreased cancer risk for carriers of the 'CG' haplotype (OR = 0.79; 95% CI = 0.66- 0.96). In the systematic meta-analysis, the XbaI 'G' allele was associated with an overall significantly decreased risk of breast cancer (OR = 0.90, 95% CI = 0.82- 1.00). In addition, the PvuII 'C' allele showed a 0.96- fold decreased disease risk (95% CI = 0.92- 0.99). In subgroup analysis, an association between the PvuII 'C' and XbaI 'G' alleles and breast cancer risk was significant in Asians ('C' vs. 'T': OR = 0.93, 95% CI = 0.85- 1.00; 'G' vs. 'A': OR = 0.82, 95% CI = 0.68- 0.98), but not in Euro-Americans. Thus, our results provide evidence that ESR-α polymorphisms are associated with susceptibility to breast cancer. These associations may largely depend on population characteristics and geographic location.

Serum peroxiredoxin3 is a useful biomarker for early diagnosis and assessemnt of prognosis of hepatocellular carcinoma in Chinese patients.

BACKGROUND: Recently, peroxiredoxin3 (PRDX3) was identified as a novel molecular marker for the progression of hepatocellular carcinoma (HCC). However, its potential clinical application as a serum marker for the early diagnosis and prognosis of HCC has not been investigated. METHODS: PRDX3, alpha-fetaprotein (AFP), and other biochemical parameters were measured in serum samples from 297 Chinese patients, including 96 with HCC, 98 with liver cirrhosis (LC), and 103 healthy controls (HCs). Correlations between serum PRDX3 expression and clinicopathological variables and the relationship between serum PRDX3 expression and prognosis were analyzed. RESULTS: Serum PRDX3 was significantly higher in HCC patients than in the LC and HC groups. The sensitivity and specificity of serum PRDX3 for the diagnosis of HCC were 85.9% and 75.3%, respectively, at a cutoff of 153.26 ng/mL, and the area under the curve was 0.865. Moreover, serum PRDX3 expression was strongly associated with AFP level, tumor diameter, TNM stage, and portal vein invasion. Kaplan-Meier curve analysis revealed that HCC patients with high serum PRDX3 expression had a shorter median survival time than those with low PRDX3 expression. Moreover, serum PRDX3 expression was an independent risk factor for overall survival. The inverse correlation between serum PRDX3 and patient survival remained significant in patients with early-stage HCC and in those with normal serum AFP levels. CONCLUSIONS: Serum PRDX3 can be used as a noninvasive biomarker for the diagnosis and/or prognosis of HCC.

miR-340 reverses cisplatin resistance of hepatocellular carcinoma cell lines by targeting Nrf2-dependent antioxidant pathway.

Many chemotherapeutic agents have been successfully used to treat hepatocellular carcinoma (HCC); however, the development of chemoresistance in liver cancer cells usually results in a relapse and worsening of prognosis. It has been demonstrated that DNA methylation and histone modification play crucial roles in chemotherapy resistance. Currently, extensive research has shown that there is another potential mechanism of gene expression control, which is mediated through the function of short noncoding RNAs, especially for microRNAs (miRNAs), but little is known about their roles in cancer cell drug resistance. In present study, by taking advantage of miRNA effects on the resistance of human hepatocellular carcinoma cells line to cisplatin, it has been demonstrated that miR-340 were significantly downregulated whereas Nrf2 was upregulated in HepG2/ CDDP (cisplatin) cells, compared with parental HepG2 cells. Bioinformatics analysis and luciferase assays of Nrf2-3'-untranslated region-based reporter constructor indicated that Nrf2 was the direct target gene of miR- 340, miR-340 mimics suppressing Nrf2-dependent antioxidant pathway and enhancing the sensitivity of HepG2/ CDDP cells to cisplatin. Interestingly, transfection with miR-340 mimics combined with miR-340 inhibitors reactivated the Nrf2 related pathway and restored the resistance of HepG2/CDDP cells to CDDP. Collectively, the results first suggested that lower expression of miR-340 is involved in the development of CDDP resistance in hepatocellular carcinoma cell line, at least partly due to regulating Nrf2-dependent antioxidant pathway.