Mitochondria are cellular machines essential for energy production. The biogenesis of mitochondria is a highly complex and it depends on the coordination of the nuclear and mitochondrial genome. Mitochondrial DNA (mtDNA) mutations and deletions are suspected to be associated with carcinogenesis. The most described mtDNA deletion in various human cancers is called the 4977-bp common deletion (mDNA4977) and it has been explored since two decades. In spite of that, its implication in carcinogenesis still unknown and its predictive and prognostic impact remains controversial. This review article provides an overview of some of the cellular and molecular mechanisms underlying mDNA4977 formation and a detailed summary about mDNA4977 reported in various types of cancers. The current knowledges of mDNA4977 as a prognostic and predictive marker are also discussed.
MicroRNA (miRNA) is a small non-coding RNA with an established function to regulate genes at the post-transcriptional level leading to suppression or degradation of its messenger RNA expression (mRNA). Its dysregulation plays a vital role in a variety of biological and pathological processes including cancer. A lot of algorithms have been established to predict the target sites of miRNA, but experimentally identifying and validating its target region is still lacking. Guidance in experimental procedures is really needed to find genuine miRNA targets. Therefore, in this review, we provide an outline on the workflow in predicting and validating the targeted sites of miRNA using several methods as a guideline for the scientists. The final outcome of this type of experiment is essential to explore the major impact of miRNAmRNA interaction involved in the biological processes and to assist miRNA-based drug development in the future.