The Unexplored Ramifications of Junk DNA in Cancer Genetics

The realm of molecular biology has followed and developed upon the theory of Central Dogma since the time it was proposed by Francis Crick in 1958. It states that the transfer of genetic information occurs from the DNA to make proteins via RNA. It makes up one of the indispensable elements of contemporary biology theory. Lately, due to the advancements in the study of regulatory mechanisms of the non-coding RNA such as micro-RNA, this dogma can face numerous challenges. Earlier, just like judging a book by its cover, we believed that a big part of an organism’s genome that does not code for a translatable RNA is useless. We called this DNA “junk” DNA because it could not produce proteins. But, with the recent developments in the study of this junk DNA, it’s established that this DNA codes for a specific type of RNA, called non-coding RNA.

The contributions of non-coding RNA in pathological SNPs, and translative and transcriptional regulators have changed the narrative for junk DNA categorization. Although there is a lot unknown about these non-coding RNAs and their functionalities, it is a possibility that no DNA in humans or any other organism can be called “Junk” DNA. The lncRNA is a focal point for research because of its interactions with DNA in human cancers. The genome-wide association studies (GWAS) highlight that nearly half of the disease-related single-nucleotide polymorphisms (SNPs) are not in the protein-coding genes, i.e., gene-desert regions. On the contrary, only 10% of these SNPs are in the protein-coding parts of DNA. This observation points toward a vivid inference that the actual culprits for many diseases- phenotypes reside in these gene desert regions. For example, miRNA-15a/16-1 can cause deletions in the 13q14.3 region of the genome (which is associated with chronic lymphocytic leukemia (CLL)).?

The principal mechanism of action of these lncRNAs in cancer genetics can be of two types: Cis and trans regulations, depending on whether the gene affected by the regulation is a neighboring gene on the same chromosome (cis) or a faraway gene on another chromosome (trans). The principal lncRNAs were found and portrayed right around thirty years prior for their inclusion in genomic imprinting and chromosome dosage compensation. From that point forward, the quantity of mammalian non-coding records has stupendously expanded to a current gauge of around 30,000 lncRNAs for the human genome. Therefore, drugs focusing on lncRNAs could accomplish a more specific remedial impact than ordinary medications. LncRNAs can also serve as biomarkers because of their potential progression-free survival in diseases like prostate cancer.

The allele-explicit regulatory mechanisms of lncRNAs might be taken advantage of for precise control of gene expression, probably with lesser incidental effects. Manufactured oligonucleotides with high proclivity and specificity, for example, those with locked nucleic modifications, can permit designated regulation of lncRNA expression.?Therefore, if known and understood properly, these lncRNAs can be very effective in developing clinical applications for cancer patients. The diverse roles of these lncRNAs in cancer cells affecting cell proliferation, apoptosis, migration, invasion, and maintenance of stemness can be targeted separately according to the needs of the patient.

In addition to this, the tissue-specific expression pattern of these lncRNAs can be utilized to make them serve as biomarkers in urine or plasma for detection of cancer metastasis, predictions of clinical outcomes, and divulging the origin of metastatic cancers. They can also be viewed as potential high-specificity therapeutic targets due to their ability to increase protein output more naturally by targeting NATs. Human beings are complex creatures such that a single molecule can never explain a pathology entirely. But for a comprehensive exploration of therapeutic manipulation for a grave and complex disease like cancer, it becomes necessary to consider all the possible agents responsible for it. So, the study and consequent applications of lncRNA, and even the part of DNA considered junk are equally relevant for covering all bases to put up a strong fight against cancer.

A Scientific Blog written by Lavina Mulani - Scientific Content Writer & Mentor at Bioscinova .