Jornal de Biomarcadores Moleculares e Diagnóstico

Biomarkers are regarded highly for their ability to discriminate between genotypes in fields of genetic science. The first molecules to differentiate between various plant types were secondary metabolites such as anthocyanin, phenolic etc. Nevertheless, their wide use was restricted by several factors including uncertainty and limited availability. For the short period prior to the development of more effective DNA markers, enzyme markers (allozymes and isozymes) gained significance but with the development of the powerful DNA markers that detect variation among individuals based on the polymorphism in their DNA they regained their status. Initial application of DNA marker technology began with the use of RFLP markers for the creation of the human genome's first molecular map.

The Biomarker is “a biological molecule contained in blood, other body fluids, or tissues, a sign of a normal or abnormal process, or of a disorder or disease," like cancer as described by the National Cancer Institute (NCI). Usually biomarkers differentiate the healthy person from the patient with disease. The modifications may be caused by many factors, such as germ or somatic mutations, transcriptional changes, and post-translational changes. The spectrum of biomarkers is vast, including proteins (for instance, an enzyme or receptor), nucleic acids (e.g. micro-RNA or other non-encoding ARNs), antibodies and peptides, etc. A biomarker may also be a series of changes such as gene expression, proteomic signatures and metabolomics. Biomarker can be found in the bloodstream or excretions (stool, urine, sputum or nipple discharge) (wholly blood, serum, or plasma). 

Cancer is designated as unhindered cell growth. Gene mutations can initiatemalignancy by increasing the rate of cell division or preventing usual controls on the system, like cell cycle arrest or apoptosis. As per earlier established studies, it is well known that the primary cause of cancer is some unwanted changes in the structure of DNA that are else considered as mutations. Mutations causing cancer can be due to a number of reasons including the lack of fidelity of the DNA replication machinery, disclosures to the mutagen, enzymatic DNA alteration, and faulty repair of DNA that consequences a certain fingerprint on DNA damage. Every living cell of the human body retains somatic mutations all through life. 

Heart failure implies that the heart works less effectively and not that the heart has quit working. Heart failure is caused by many conditions that damage the heart muscle. Coronary artery disease is where the arteries minimises the supply of oxygen and blood flow to the heart muscle. When the heart muscles are damaged from infections or alcohol or drug abuse rather than the minimal supply of oxygen or blood, is known as Cardiomyopathy.

Prevention and early detection are key components of controlling the overburdened cases of mouth cancer. Mouth cancers are the 6th commonest cancer in the world with a high lethality rate. Even with technological advances happening around the globe, visual examination still remains the mostly practiced screening method for oral cancer. 

Background: Obstructive Sleep Apnea (OSA) is a highly prevalent condition that is associated with several comorbidities including cardiovascular disease (CVD). Recent studies have revealed mixed results as to whether standard OSA therapy reverses CVD in adult patients. Thus, many advocate for earlier recognition of OSA induced CVD, as early as childhood, to prompt treatment antecedent to the onset of irreversible CVD. Here we investigated if the serum level of miR-92a, a known biomarker for CVD, can be used to identify patients with OSA in both children and adults. Methods: Consecutive snoring patients undergoing polysomnography were recruited for determination of circulating miR-92a, in addition to inflammatory and metabolic profiles. We assessed whether circulating miR-92a was associated with OSA severity. Results: Using two separate cohorts of adults (n=57) and children (n=13), we report a significant increase in the serum level of miR-92a in patients with severe OSA (p=0.021) and further demonstrate a significant correlation (Spearman rank correlation 0.308, p=0.010) with serum miR-92a levels and the apnea hypopnea index (AHI), a primary measure of OSA severity. Stepwise regression analysis revealed that serum miR-92a levels were independently associated with AHI (ß=0.332, p=0.003), age (ß=0.394, p=0.002) and LDL cholesterol levels (ß=0.368, p=0.004). Conclusion: Our study is the first to establish that miR-92a is a useful biomarker for OSA severity in both children and adults. Given the canonical role of miR-92a on endothelial dysfunction, miR-92a may be useful to identify early onset CVD in OSA patients or stratify patient CVD risk to identify those that may benefit from earlier OSA treatment.