Lung has critic function in gas exchange, supplying oxygen to all cells. Rapid metastasis and the high rate of mortality characterises lung cancer. There are two types of this disease, small cell and non-small cell, which differs from each other according to histopathologic features. To date, many therapeutic approaches have been developed to destroy this deadly type of cancer, which one of them is mRNA targeted therapies through miRNA. miRNAs are 19-25 base paired molecules be able to suppress and destruct mRNA and found to be involved in development and progression of lung cancer. Transmembrane Protein 48 (TMEM48) is localised on nuclear pore complex and plays critic roles in nuclear traffic. Known that TMEM48 gene overexpressed in non-small lung cancer cells. Growing TMEM48 suppressed therapeutic studies indicated that decreased TMEM48 level might reveal a therapeutic effect for non-small cell lung cancers. TMEM48 studies based on the same strategy of gene-silencing, however, to our knowledge, any report has been published evaluates TMEM48's regulation by miRNAs. We aimed to clarify if miR-421 might be therapeutic player for non-small cancer cell lines (A549), hereby we suppressed TMEM48 by miR-421 and performed advanced molecular tests. Consequently, we recorded that while miR-421 is significantly suppressing TMEM48 expression; it increased apoptotic and tumor suppressor players CASPASE 3, PTEN and TP53 in A549 line, which is consistent with Annexin V - PI results: 30,6% of A549 observed to be apoptotic - 68,5% of A549 was in GO/G1. Our study indicated that miR-421 can suppress TMEM48 so that leads the cells to apoptosis. But it is not entirely clear how miR-421 triggers apoptosis and whether it interacts with the other cellular death pathways in A549. (C) 2018 Elsevier Inc. All rights reserved.