A comprehensive evaluation for polymorphisms in let-7 family in cancer risk and prognosis: a system review and meta-analysis

Abstract

miRNA polymorphisms had potential to be biomarkers for cancer susceptibility and prognosis. The mature miRNA-let-7 family was considered as the most important miRNA for the cancer incidence and progression. Recently, the promising let-7 miRNAs were reported to be associated with various cancers, but the results were inconsistent. We performed a first-reported systematic review with a meta-analysis for the association of let-7 family single nucleotide polymorphisms (SNPs) with cancer risk/prognosis. Ten studies were included with a total of 3878 cancer cases and 4725 controls for the risk study and 1665 cancer patients for the prognosis study in this meta-analysis. In the risk study, the let-7i rs10877887 and let-7a-1/let-7f-1/let-7d rs13293512 were shown no significant association for the overall cancer risk. In the stratified analysis, the rs10877887 variant genotype was significantly associated with a decreased cancer risk in head and neck cancer (TC compared with TT: P=0.017; odds ratio (OR) = 0.81; TC + CC compared with TT: P=0.020; OR = 0.82). In the prognosis study, the let-7i rs10877887 SNP was shown to be associated with a higher risk for cancer prognosis in the dominate model (P=0.004; hazard ratio (HR) = 1.32). The other two SNPs (let-7a-1 rs10739971 and let-7a-2 rs629367) were not found to be associated with cancer survival. None of the let-7 family polymorphisms had potential to be biomarkers for cancer susceptibility but let-7i rs10877887 SNP had potential to be predicting markers for cancer prognosis. In the future, large-sample studies are still needed to verify our findings.

Serum expression of selected miRNAs in patients with laryngeal squamous cell carcinoma (LSCC)

“…Members of the Let-7 miRNA family have been reported to be differentially expressed in various types of cancers [25], and serum miRNA Let-7a was found to be overexpressed in LSCC subjects in the present study. In contrast, Song et al [26] demonstrated significant down-regulation of Let-7a in laryngeal cancer tissue compared to adjacent normal tissue, including 59 paired laryngeal tissues, and that Let-7a expression negatively correlated with higher TNM stage and lymph node metastasis.…”

Association between Cyclin D1 G870A (rs9344) polymorphism and cancer risk in Indian population: meta-analysis and trial sequential analysis

“…In the similar lines, study by Zheng et al (2015) [ 53 ] suggested that CCND1 polymorphism may not be associated with the risk of prostate cancer. Similarly, Wang et al (2018) [ 54 ] also found no significant association between the let-7i rs10877887 and let-7a-1/let-7f-1/let-7d rs13293512 polymorphisms and overall cancer risk. In disagreement with our findings a meta-analysis by Pabalan et al (2008) [ 51 ], showed an increased cancer risk associated with CCND1 -A870G polymorphism in the human population.…”

Genetic variations in MicroRNA genes and cancer risk: A field synopsis and meta‐analysis

“…We concluded that many of the existing statistically significant meta‐analyses on associations of cancer with miRNA polymorphism may not be significant under strict criteria using FPRP. There have been multiple studies assessing the noteworthiness of results from meta‐analyses identifying SNP by using FPRP; however, they only assessed a single cancer type . In spite of the limitations, our study is a systematic review to provide evidence for miRNA variance to be related to various types of cancer.…”

“…There have been multiple studies assessing the noteworthiness of results from meta-analyses identifying SNP by using FPRP; however, they only assessed a single cancer type. 43,44 In spite of the limitations, our study is a systematic review to provide evidence for miRNA variance to be related to various types of cancer. It encourages the site-specific investigation of miRNA variant function and its associations with ethnicity.…”