These findings suggested that SNPs rs71428439 (miR-149), rs2910164 (miR-146a), rs928508 (mir-30c-1) and rs629367 (let-7a-2) were associated with the lung cancer prevalence, polymorphisms of rs11614913 (miR-196a-2) and rs9280508 (miR-30c-1) significantly influenced the patients' response to platinum-based chemotherapy, which may serve as potential clinical biomarkers to predict lung cancer risk and platinum-based chemotherapy response.
Our study suggested that the miR-196a2 gene rs11614913 polymorphism and the miR-146a gene rs2910164 polymorphism might associate with lung cancer risk.
We also found, in clinical formalin fixed paraffin embedded (FFPE) lung cancer samples, that low expression of miR-146a was correlated with advanced clinical TNM stages and distant metastasis in NSCLC (P<0.05).
The individuals with both risk genotypes of miRNA SNPs and exposure to risk factor (cooking oil fumes) were in a higher risk of lung cancer than persons with only one of the two risk factors (ORs were 1.91, 1.05 and 1.41 for miR-146ars2910164, ORs were 1.94, 1.23 and 1.34 for miR-196a2 rs11614913, ORs were 2.06, 1.41 and 1.68 for miR-608 rs4919510, ORs were 1.76, 0.82 and 1.07 for miR-27a rs895819, and ORs were 2.13, 1.15 and 1.02 for miR-423 rs6505162, respectively).
In a CAM xenograft tumor model, overexpression of miR‑146a‑5p inhibited the tumorigenesis and angiogenesis of an NSCLC cell line. miR‑146a‑5p may act as a tumor suppressor gene in NSCLC and have moderate prognostic value in lung cancer.
These findings suggest that the rs2910164C>G in pre-miR-146a may contribute to genetic susceptibility to lung cancer, and that miR-146a might be involved in lung cancer development.
In conclusion, miR-146a and miR-196a-2 genes polymorphisms and their circulating levels were associated with lung cancer risk in Egyptians and may be helpful in early detection of lung cancer.
These findings suggest that miR-146a rs2910164C>G and miR-423 rs6505162C>A polymorphisms may contribute to genetic susceptibility to lung cancer and lung adenocarcinoma in Chinese non-smoking females.