Post-transcriptional regulation plays a key role in modulating gene expression, and the perturbation of transcriptomic equilibrium has been shown to drive the development of multiple diseases including cancer

Post-transcriptional regulation plays a key role in modulating gene expression, and the perturbation of transcriptomic equilibrium has been shown to drive the development of multiple diseases including cancer. subsequent upregulation of KRAS in non-small cell lung cancer (NSCLC) patients [59]. Point mutations in miRNA target genes can be harnessed to develop powerful, targeted cancer therapies. Senkyunolide A Acunzo et al. [60] devised miRNA-like artificial molecules (amiRNAs) and showed that amiR-KS3 specifically targets mutant transcripts carrying the G12S mutation without affecting wild-type transcripts in NSCLC. This Senkyunolide A amiR-KS3 treatment was also found to be effective in other cancers associated with G12S mutation. As more than 30% of all human cancers, including 95% of pancreatic cancers and 45% of colorectal cancers, are driven by family mutations, these amiRNAs specific to oncogenic may represent a significant breakthrough towards using miRNA drugs as personalized therapies for cancer. 5. 3UTR Shortening Transforms the miRNA Regulatory Scenery In addition to genetic mutations, alterations in post-transcriptional regulatory processes can also transform miRNA/target interactomes. The majority of identified miRNA binding sites are in the 3UTRs of target transcripts, which were once thought to be unimportant as they did not possess protein-coding potential. Now established as crucial regulatory regions of mRNAs, 3UTRs frequently undergo option cleavage and polyadenylation (APA), which results in the loss or gain of multiple miRNA binding sites. Genome-wide studies have revealed a high prevalence of APA: 50C70% of human mRNAs possess multiple 3UTR isoforms [61,62]. APA-mediated 3UTR shortening has been described in multiple cancers [63,64,65,66,67,68,69,70,71,72,73,74,75]. NUDT21, a key regulator of APA, is frequently downregulated in several cancers [66,67,69,70,76]. Knockdown of NUDT21 causes 3UTR shortening of various oncogenes by increasing the usage of proximal polyadenylation sites, leading to significant increases in cell proliferation, migration, and xenograft growth [66,68,70]. Conversely, restoration of NUDT21 expression guarded the proximal actual polyadenylation site (PAS) from cleavage by CPSF, leaving only the cleavage of distal PAS. This increased miRNA-mediated transcript repression, and thus decreased malignancy growth. Oncogene transcripts that undergo 3UTR truncation often exhibit enhanced oncogenic properties [77,78]. Mechanistically, the shorter 3UTR Rabbit polyclonal to COT.This gene was identified by its oncogenic transforming activity in cells.The encoded protein is a member of the serine/threonine protein kinase family.This kinase can activate both the MAP kinase and JNK kinase pathways. isoforms exhibit greater Senkyunolide A stability, and subsequently higher protein expression than the corresponding full-length transcripts, in part because of the loss of miRNA binding sites [63,65,79,80]. These studies in cell lines were corroborated by a study by Andres and colleagues [65], who found that 3UTR shortening of insulin-like growth factor mRNA binding protein 1 (IGF2BP1) led to the loss of let-7 regulation, resulting in elevated IGF2BP1 expression and accelerated liver metastasis in colorectal cancer patients. Multiple studies have exhibited that the loss of miRNA regulation around the shortened 3UTRs of oncogenes promotes tumor phenotypes in several cancers, thus suggesting that it is a widespread mechanism by which oncogenes evade post-transcriptional repression [79,81,82,83,84]. 3UTR shortening also has a ripple effect on the associated ceRNA networks, as the loss of MREs increases the available pool of miRNAs, shifting miRNA-directed repression onto the wider ceRNA network and decreasing ceRNA expression (Physique 2B). This has been observed in breast malignancy cell lines, where the shortening of the 3UTR causes the downregulation of its ceRNA 3UTR shortening decreases the expression of its ceRNA [85]. In addition to the loss of RNA/RNA interactions, 3UTR shortening also results in a loss of RNA/protein interactions with RNA binding proteins (RBPs) [86]. For example, the long 3UTR of is usually associated with HuR and SET, facilitating the translocation Senkyunolide A of CD47 protein to the plasma membrane. In contrast, the short 3UTR isoform has fewer HuR binding sites, resulting in CD47 protein localization to the endoplasmic reticulum [86]. As RBPs regulate transcripts at multiple stages of their life cycle, it is likely that the loss of RBP regulation on shortened 3UTR transcripts could have a variety of effects on transcript expression and downstream protein function. Clinically, APA has shown promise as a prognostic marker, whereby the different clusters of APA have been used successfully to predict survival outcome of lymphoma patients [73] and relapse in prostate cancer patients [87]. 6. RNA Methylation Regulates Epitranscriptomic Plasticity In the 1970s, the discovery of modifications on specific nucleotides around the mRNAs of rat Novikoff hepatoma.