Epigenetic Suppression of the T-box Subfamily 2 (TBX2) in Human Non-Small Cell Lung Cancer.

(1) The TBX2 subfamily of transcription factors (TBXs 2, 3, 4 and 5) are markedly down-regulated in human non-small cell lung cancer (NSCLC) and exert tumor suppressor effects in lung malignancy. Yet, mechanisms underlying suppressed expression of the TBX2 subfamily in NSCLC are elusive. Here, we interrogated probable epigenetic mechanisms in suppressed expression of the TBX2 subfamily in human NSCLC. (2) TBX2 subfamily gene expression and methylation levels in NSCLC and normal lung tissues were surveyed using publicly available RNA-sequence and genome-wide methylation datasets. Methylation ß-values of the four genes were statistically compared between NSCLCs and normal lung tissues, correlated with gene expression levels, and interrogated with clinicopathological variables. Expression and methylation levels of TBXs were quantified in NSCLC cells using real-time PCR and methylation-specific PCR assays, respectively. Effects of the DNA methyltransferase inhibitor 5-azacytidine (Aza) on TBX2 subfamily expression were assessed in NSCLC cells. Impact of TBX2 subfamily expression on Aza-treated cells was evaluated by RNA interference. (3) All four TBXs were significantly hypermethylated in NSCLCs relative to normal lung tissues (p < 0.05). Methylation ß-values of the genes, with exception of TBX2, were significantly inversely correlated with corresponding mRNA expression levels (p < 0.05). We found no statistically significant differences in hypermethylation levels of the TBX2 subfamily by clinicopathological features including stage and tobacco history. Expression levels of the TBX genes were overall suppressed in NSCLC cells relative to normal alveolar cells. Members of the subfamily were significantly hypermethylated in all tested NSCLC cell lines relative to normal alveolar cells. Treatment with Aza induced the expression of the TBX2 subfamily concomitant with NSCLC cell growth inhibition. Further, simultaneous knockdown of the four TBX genes markedly reduced anti-growth effects of Aza in NSCLC cells. (4) Our study sheds light on new epigenetic profiles in the molecular pathogenesis of human NSCLC.

The Emerging Role of Proteomics in Precision Medicine: Applications in Neurodegenerative Diseases and Neurotrauma.

Inter-individual variability in response to pharmacotherapy has provoked a higher demand to personalize medical decisions. As the field of pharmacogenomics has served to translate personalized medicine from concept to practice, the contribution of the "omics" disciplines to the era of precision medicine seems to be vital in improving therapeutic outcomes. Although we have observed significant advances in the field of genomics towards personalized medicine , the field of proteomics-with all its capabilities- is still in its infancy towards the area of personalized precision medicine. Neurodegenerative diseases and neurotrauma are among the areas where the implementation of neuroproteomics approaches has enabled neuroscientists to broaden their understanding of neural disease mechanisms and characteristics. It has been shown that the influence of epigenetics, genetics and environmental factors were among the recognized factors contributing to the diverse presentation of a single disease as well as its treatment establishing the factor-disease interaction. Thus, management of these variable single disease presentation/outcome necessitated the need for factoring the influence of epigenetics, genetics, epigenetics, and other factors on disease progression to create a custom treatment plan unique to each individual. In fact, neuroproteomics with its high ability to decipher protein alterations along with their post translational modifications (PTMs) can be an ideal tool for personalized medicine goals including: discovery of molecular mechanisms underlying disease pathobiology, development of novel diagnostics, enhancement of pharmacological neurotherapeutic approaches and finally, providing a "proteome identity" for patients with certain disorders and diseases. So far, neuroproteomics approaches have excelled in the areas of biomarker discovery arena where several diagnostic, prognostic and injury markers have been identified with a direct impact on the neurodegenerative diseases and neurotrauma. However, other applications in proteomics such as "individual" proteome sequencing with its signature PTMs, have not been fully investigated as compared to the achievements in the genomics discipline This infers that proteomics research work has promising potential, yet to be discovered, in the precision medicine and comprises a major component of the personalized medicine infrastructure as it allows individual characterization of disease at the protein level. To conclude, the field of proteomics-based personalized medicine is still in its infancy compared to genomics field due to several technical and instrumentation-based obstacles; however, we anticipate to have this initiative leading in the coming future. This chapter will discuss briefly how neuroproteomics can impact personalized medicine in the fields of neurodegenerative disorders particularly in Alzheimer's disease and brain injury .