DNA methylation profiling reveals the presence of population-specific signatures correlating with phenotypic characteristics.

Phenotypic characteristics are known to vary substantially among different ethnicities around the globe. These variations are mediated by number of stochastic events and cannot be attributed to genetic architecture alone. DNA methylation is a well-established mechanism that sculpts our epigenome influencing phenotypic variation including disease manifestation. Since DNA methylation is an important determinant for health issues of a population, it demands a thorough investigation of the natural differences in genome wide DNA methylation patterns across different ethnic groups. This study is based on comparative analyses of methylome from five different ethnicities with major focus on Indian subjects. The current study uses hierarchical clustering approaches, principal component analysis and locus specific differential methylation analysis on Illumina 450K methylation data to compare methylome of different ethnic subjects. Our data indicates that the variations in DNA methylation patterns of Indians are less among themselves compared to other global population. It empirically correlated with dietary, cultural and demographical divergences across different ethnic groups. Our work further suggests that Indians included in this study, despite their genetic similarity with the Caucasian population, are in close proximity with Japanese in terms of their methylation signatures.

Association of IL-10 GTC haplotype with serum level and HPV infection in the development of cervical carcinoma.

AIM: Cervical cancer is the most common gynecological malignancy in the developing countries like India. In addition to human papillomavirus (HPV) infection, host genetic factors play an important role in viral persistence and neoplastic growth. IL-10, a multifunctional cytokine, plays an active role to promote tumor growth in the presence of HPV. The present study aims to find out the impact of IL-10 promoter polymorphisms at -1082A/G (rs1800896), -819C/T (rs1800872), and -592C/A (rs1800871) sites along with IL-10 production and HPV infection in the progression of cervical cancer. METHODS: We have genotyped a total of 506 subjects, 256 cases (208 cervical cancer + 48 precancer), and 250 healthy controls by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method followed by sequencing. IL-10 serum concentration was measured by enzyme-linked immunosorbent assay. RESULTS: The frequency of IL-10 -592 variant genotype (AA) was found significantly reduced in cases as compare to controls while -1082 variant genotype (GG) was found ~4-fold higher risk of cervical cancer (p = <0.0001, OR = 3.667, 95% CI = 2.329-5.773). On construction of haplotypes, GTC haplotype was emerged as a major risk haplotype while ACA haplotype was seemed as a marker for precancerous lesions. IL-10 serum concentration was observed higher in HPV-infected precancer and cancer cases. GTC haplotype was found to be coupled with higher serum concentration of IL-10 and HPV infection. CONCLUSION: IL-10 polymorphisms play a role in cervical cancer development and that GTC haplotype, which is closely related to its serum concentration, maybe a useful biomarker for HPV-mediated cervical cancer.

Cellular enlargement - A new hallmark of aging?

Years of important research has revealed that cells heavily invest in regulating their size. Nevertheless, it has remained unclear why accurate size control is so important. Our recent study using hematopoietic stem cells (HSCs) in vivo indicates that cellular enlargement is causally associated with aging. Here, we present an overview of these findings and their implications. Furthermore, we performed a broad literature analysis to evaluate the potential of cellular enlargement as a new aging hallmark and to examine its connection to previously described aging hallmarks. Finally, we highlight interesting work presenting a correlation between cell size and age-related diseases. Taken together, we found mounting evidence linking cellular enlargement to aging and age-related diseases. Therefore, we encourage researchers from seemingly unrelated areas to take a fresh look at their data from the perspective of cell size.