The Interaction of NTN4 and miR-17-92 Polymorphisms on Breast Cancer Susceptibility in a Chinese Population.

INTRODUCTION: Genome-wide association studies have identified a genetic variant rs17356907 in netrin 4 (NTN4) as a risk locus of breast cancer (BC) in Europeans. NTN4 is a target gene of miR-17-92 cluster that is an oncogenic miRNA in BC development. We aimed to replicate the rs17356907 in a Chinese population and examine the interaction of NTN4 and miR-17-92 on BC susceptibility. MATERIALS AND METHODS: The rs17356907 in NTN4 and 3 additional polymorphisms in the promoter of miR-17-92 (ie, rs9588884, rs982873, and rs1813389) were determined in 415 patients with BC and 420 healthy controls using a TaqMan assay. The expression levels of NTN4 in BC and normal tissues were performed using the quantitative reverse transcription-PCR. RESULTS: With reference to the rs17356907AA genotype, the GG genotype was associated with a decreased risk of BC with an adjusted OR of 0.38 (95% CI: 0.20-0.74). With reference to the rs17356907AA-rs982873CT/CC genotypes, the rs17356907 AG/GG-rs982873CT/CC genotypes were associated with a borderline decreased risk of BC with an adjusted OR of 0.67 (95% CI: 0.48-0.93). Gene-gene interaction analysis showed that the rs17356907-rs982873-rs9588884-rs1813389 was the best model on BC susceptibility. Furthermore, the rs17356907GG genotype displayed higher levels of NTN4 mRNA. CONCLUSIONS: The NTN4 rs17356907 may have a single and interactive effect with miR-17-92 polymorphisms on the risk of BC.

Heat shock factor 2 is associated with the occurrence of lung cancer by enhancing the expression of heat shock proteins.

Cancer is the leading cause of morbidity and mortality worldwide, particularly lung cancer. Heat shock proteins and their upstream heat shock factors are involved in the occurrence of cancer and have been widely researched. However, the role of heat shock factor 2 (HSF2) in lung cancer remains unclear. In the present study, expression levels of HSF2 in lung cancer tissues from 50 lung cancer patients were detected by reverse transcription quantitative polymerase chain reaction, and 76% (38/50) were upregulated compared with the matched normal tissues. This suggested possible involvement of HSF2 in lung cancer. To additionally investigate the role of HSF2 in lung cancer occurrence, a plasmid encoding HSF2 was constructed. HSF2 was over expressed in normal lung epithelial BEAS-2B cells and lung cancer A549 cells. The results showed that HSF2 overexpression promoted cell proliferation and cell migration in BEAS-2B and A549 cells. Additional experiments showed that the HSF2-induced cell proliferation and cell migration were dependent on induction of HSPs, particularly HSP27 and HSP90, as co-transfection of HSP27 small interfering RNA (siRNA) or HSP90 siRNA attenuated HSF2-induced cell growth and migration. In conclusion, the present study showed that HSF2 is aberrantly expressed in lung cancer, and it may be an upstream regulator of HSPs, which may strongly affect cell growth and cell migration. Additional studies are required to explain the detailed mechanism between lung cancer, HSF2, HSPs and other possible signaling pathways.