MicroRNAs are non-coding RNAs which expresses the regulation of genes both at transcriptional and translational level. The effect and de-regulation of microRNAs has been related to almost every type of cancer especially lung cancer with respect to non-tumor tissue. The effect of microRNA contributes to human carcinogenesis; evidence shows that microRNA can be detected in human body fluids, it can be used as tumor biomarker with diagnostic and prognostic implications. It is shown that microRNA can have hundreds of different targets and a good percentage of genes are regulated by at least one microRNA.
However, tumor formation is a complex multistep process characterized by several events such as accumulation of genomic alterations, uncontrolled growth, angiogenesis invasion and metastasis, all these processes are possibly regulated by microRNAs. The involvement of microRNAs in cancer arises from the observation that small molecules are expressed in neoplastic tissues compared to normal tissues. Lung cancer is the most common cause of cancer death among others types of cancer worldwide. microRNAs binds other target microRNAs which causes the degradation of microRNA; researches shows that MicroRNAs play diverse roles in regulating cell growth which leads to cancer generation especially lung cancer, non-small cell cancer specifically.
There are several examples of microRNAs related to non-small cell lung cancer, they are micro-221, microRNA-222, microRNA-449a, microRNA-21, microRNA-21 etc., and research shows that deregulation of these microRNA expression can leads to the development of non-small cell cancer. MicroRNAs are generally hazardous to human body since it supports the development of cancer, therefore every possible means that can be used to remove them from the body system should be carried out so as to reduce the risk of cancer. Interestingly some microRNA actually helps in suppressing cancer tumor, these microRNAs having a tumor suppressor function ends with the cluster microRNA-143 and microRNA-145.