en Cancer Biology Cancer Biology مقاله کامل Full Length/Original Article <span style="font-size:11px;"><span style="line-height:normal"><span calibri=""><b><span style="color:black">Background:</span></b><span style="color:black"> Let-7f has essential impacts on biological processes; however, its biological and molecular functions in lung cancer pathogenesis have yet been remained unclear. We aimed to investigate the expression level of let-7f and its candidate target genes both in lung cancer tissues and A549 cell line.</span></span></span><br> <span style="line-height:normal"><span calibri=""><b><span style="color:black">Methods:</span></b><span style="color:black"> Bioinformatics databases were first used to select candidate target genes of let-7f. Then the relative gene and protein expressions of let-7f and its target genes, including HMGA2, ARID3B, SMARCAD1, and FZD3, were measured in lung tissues of Non-Small Cell Lung Cancer (NSCLC) patients and A549 cell line using </span><span style="background:white"><span style="color:black">quantitative real-time PCR</span></span><span style="color:black"> and Western blotting. The electroporation method was used to transfect A549 cells with let-7f mimic and microRNA inhibitor. The impact of let-7f transfection on the viability of A549 cells was assessed using MTT assay. The expression data of studied genes were analyzed statistically</span></span></span><br> <span style="line-height:normal"><span calibri=""><b><span style="color:black">Results:</span></b><span style="color:black"> Results indicated significant downregulated expression level of let-7f-5p (<i>p</i> = 0.0013) and upregulated level of the HMGA2 and FZD3 in NSCLC cases (<i>p</i> < 0.05). In A549 cells, after transfection with let-7f mimic, the expression of both mRNA and protein levels of HMGA2, ARID3B, SMARCAD1, and FZD3 decreased. Also, the overexpression of let-7f significantly inhibited the A549 cell proliferation and viability (<i>p</i> = 0.017).</span></span></span><br> <b><span style="line-height:115%"><span calibri=""><span style="color:black">Conclusion: </span></span></span></b><span style="line-height:115%"><span calibri=""><span style="color:black">Our findings<b> </b>exhibited the high value of let-7f and HMGA2 as biomarkers for NSCLC. The let-7f, as a major tumor suppressor regulatory factor via direct targeting genes (e.g. HMGA2), inhibits lung cancer cell viability and proliferation and could serve as a marker for the early diagnostic of</span> NSCLC. </span></span></span> MicroRNAs, Biomarkers, Carcinoma, Non-Small-Cell Lung 209 218 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-3370-3&slc_lang=en&sid=1 Venus Zafari venuszafari1389@gmail.com 0000-0003-0027-7029 No Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Milad Asadi miladasadi1389@gmail.com 0000-0001-7846-2908 No Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Nasim Bakhtiyari Bakhtiyari.nasim1@gmail.com 0000-0001-7911-2969 No Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Mahsa Sadeghzadeh Mahsa_Sadeghzadeh89@yahoo.com 0000-0003-2440-0052 No Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Majid Khalili Khalili876@gmail.com 0000-0001-5162-2174 No Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Habib Zarredar Habib_zarredar@yahoo.com 0000-0002-7217-7521 No Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Soghra Bornehdeli Soghra.bornedeli1988@gmail.com 0000-0002-5513-4175 No Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Ensiyeh Seyedrezazadeh e.s.rezazadeh@gmail.com 0000-0001-5783-5217 Yes Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran