BackgroundEmerging evidences proposed that microRNAs are associated with regulation of distinct physio-pathological processes including development of normal stem cells and carcinogenesis. In this study we aimed to investigate microRNA profile of cancer stem-like cells (CSLCs) isolated form freshly resected larynx cancer (LCa) tissue samples.MethodsCD133 positive (CD133+) stem-like cells were isolated from freshly resected LCa tumor specimens. MicroRNA profile of 12 pair of CD133+ and CD133− cells was determined using microRNA microarray and differential expressions of selvected microRNAs were validated by quantitative real time PCR (qRT-PCR).ResultsMicroRNA profiling of CD133+ and CD133− LCa samples with microarray revealed that miR-26b, miR-203, miR-200c, and miR-363-3p were significantly downregulated and miR-1825 was upregulated in CD133+ larynx CSLCs. qRT-PCR analysis in a total of 25 CD133+/CD133− sample pairs confirmed the altered expressions of these five microRNAs. Expressions of miR-26b, miR-200c, and miR-203 were significantly correlated with miR-363-3p, miR-203, and miR-363-3p expressions, respectively. Furthermore, in silico analysis revealed that these microRNAs target both cancer and stem-cell associated signaling pathways.ConclusionsOur results showed that certain microRNAs in CD133+ cells could be used as cancer stem cell markers. Based on these results, we propose that this panel of microRNAs might carry crucial roles in LCa pathogenesis through regulating stem cell properties of tumor cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2863-3) contains supplementary material, which is available to authorized users.

Patients with end-stage renal disease (ESRD) display enhanced genomic damage. DNA repair gene polymorphisms may affect DNA repair capacity and modulate susceptibility to ESRD. In this study, we aimed to determine the frequency of polymorphisms in two DNA repair enzyme genes, Xeroderma pigmentosum complementation group D (XPD) and X-ray cross-complementing group 1 (XRCC1), in patients with ESRD and to evaluate their association with ESRD development. By using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), we genotyped four single nucleotide polymorphisms (SNPs) in XPD codons 312 and 751 and XRCC1 codons 194 and 399 in 136 dialysis patients (71 patients undergoing hemodialysis and 65 subjected to peritoneal dialysis) and 147 healthy controls. Patients having XRCC1 399 Arg/Gln (OR:1.98; 95% CI: 1.21-3.25, P = 0.007) or XRCC1-399 Gln/Gln (OR: 3.95; 95% CI: 1.45-10.76, P = 0.005) genotype had a significantly higher risk of ESRD than those with XRCC1 399 Arg/Arg genotype. We also found a significantly higher frequency of the XRCC1 399Gln allele in patients with ESRD than in controls, with OR = 2.03 (95% CI = 1.08-3.81, P = 0.03). We further investigated the potential combined effect of these DNA repair variants on the risk of ESRD development. It was found that combination of the Arg/Gln or Gln/Gln genotypes of XRCC1 Arg399Gln polymorphism with the two possible genotypes of XPD-Asp312Asn or with the Lys/Gln or Gln/Gln genotypes of XPD Lys751Gln was significantly associated with the development of ESRD. This is the first report showing an association between DNA repair gene polymorphisms and ESRD development, and suggests that XRCC1 Arg399Gln polymorphism may confer increased risk for the development of the disease. Further larger studies should be conducted to confirm these results.

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