MALAT1 as a Versatile Regulator of Cancer: Overview of the Updates from Predatory Role as Competitive Endogenous RNA to Mechanistic Insights

Abstract

The central dogma of molecular biology, has remained a cornerstone of classical molecular biology. However, serendipitously discovered microRNAs (miRNAs) in nematodes paradigmatically shifted our current knowledge of the intricate mechanisms during transitions from transcription to translation. Thediscovery of miRNA captured considerable attention and appreciation, and we had witnessed an explosion in the field of non-coding RNAs. Ground-breaking discoveries in the field of non-coding RNAs have helped in better characterization of microRNAs and long noncoding RNAs (LncRNAs). There is an ever-increasing list of miRNA targets that are regulated by MALAT1 to stimulate or repress the expression of target genes. However, in this review, our main focus is to summarize mechanistic insights on MALAT1-mediated regulation of oncogenic signaling pathways. We have discussed how MALAT1 modulated TGF/SMAD and Hippo pathways in various cancers. We have also comprehensively summarized how JAK/STAT and Wnt/β-catenin pathways stimulated MALAT1 expression and consequentially how MALAT1 potentiated these signaling cascades to promote cancer. MALAT1 research has undergone substantial broadening. However, there is still a need to identify additional mechanisms. MALAT1 is involved in the multi- -layered regulation of multiple transduction cascades, and detailed analysis of different pathways will be advantageous in getting a step closer to individualized medicine.