Linking polymorphic p53 response elements with gene expression in airway epithelial cells of smokers and cancer risk

Genetic variants in promoter region of TFR2 is associated with the risk of non-alcoholic fatty liver disease in a Chinese Han population: a case-control study

Background

Iron overload is frequently observed in non-alcoholic fatty liver disease (NAFLD). Transferrin receptor 2 (TFR2) is an important key factor in iron regulation. We aimed to investigate whether TFR2 single nucleotide polymorphisms (SNPs) contribute to susceptibility to NAFLD in a Chinese Han population.

Methods

Five tag SNPs (rs10247962, rs4434553, rs2075672, rs1052897, and rs3757859) in the TFR2 gene were selected and genotyped in a case–control study on participants who visited two affiliated hospitals of Fujian Medical University between June 2011 and August 2017. Propensity score matching and inverse probability of treatment weighting analyses were used to verify the risk associated with TFR2 SNPs.

Results

Logistic regression analyses suggested that subjects with the rs4434553 GA or GG genotype had a lower risk of NAFLD than those carrying the AA genotype (odds ratio = 0.630, 95% confidence interval = 0.504–0.788). Moreover, the rs4434553 GA or GG genotype was negatively correlated with body mass index, hepatic steatosis index, and serum ferritin (b = −0.363, P = 0.008; b = −1.040, P = 0.009; b = −35.258, P = 0.015, respectively), and positively associated with serum hepcidin level (b = 35.308, P < 0.001). Moreover, rs10247962 and rs1052897 had multiplicative interactions with age in relation to the risk of NAFLD (P for interactions, 0.041 and 0.034, respectively). The cumulative effects of the rs10247962, rs1052897, and rs4434553 SNPs were positively associated with the risk of NAFLD (adjusted P_trend = 0.012).

Conclusions

In this Chinese Han population, the rs4434553 polymorphism in TFR2 may be an independent influencing factor associated with the susceptibility to NAFLD. The ageing effect on the development of NAFLD may be inhibited by SNPs rs10247962 and rs1052897.

National Institute of Environmental Health Sciences: 50 Years of Advancing Science and Improving Lung Health

The American Thoracic Society celebrates the 50th anniversary of the National Institute of Environmental Health Sciences (NIEHS). The NIEHS has had enormous impact through its focus on research, training, and translational science on lung health. It has been an advocate for clean air both in the United States and across the world. The cutting-edge science funded by the NIEHS has led to major discoveries that have broadened our understanding of the pathogenesis and treatment for lung disease. Importantly, the NIEHS has developed and fostered mechanisms that require cross-cutting science across the spectrum of areas of inquiry, bringing together environmental and social scientists with clinicians to bring their expertise on specific areas of investigation. The intramural program of the NIEHS nurtures cutting-edge science, and the extramural program encourages investigator-initiated research while at the same time providing broader direction through important initiatives. Under the umbrella of the NIEHS and guided by Dr. Linda Birnbaum, the director of the NIEHS, important collaborative programs, such as the Superfund Program and the National Toxicology Program, work to discover mechanisms to protect from environmental toxins. The American Thoracic Society has overlapping goals with the NIEHS, and the strategic plans of both august bodies converge to synergize on population lung health. These bonds must be tightened and highlighted as we work toward our common goals.

Genetic Modifiers of the p53 Pathway

The tumor suppressor gene TP53 is the most frequently mutated gene in human cancer; this gene is subject to inactivation by mutation or deletion in >50% of sporadic cancers. Genes that encode proteins that regulate p53 function, such as MDM2, MDM4, and CDKN2A (p14(ARF)) are also frequently altered in tumors, and it is generally believed that the p53 pathway is likely to be inactivated by mutation in close to 100% of human tumors. Unlike most other cancer-relevant signaling pathways, some of the genes in the p53 pathway contain functionally significant single nucleotide polymorphisms (SNPs) that alter the amplitude of signaling by this protein. These variants, thus, have the potential to impact cancer risk, progression, and the efficacy of radiation and chemotherapy. In addition, the p53 pathway plays a role in other biological processes, including metabolism and reproductive fitness, so these variants have the potential to modify other diseases as well. Here we have chosen five polymorphisms in three genes in the p53 pathway for review, two in TP53, two in MDM2, and one in MDM4. These five variants were selected based on the quality and reproducibility of functional data associated with them, as well as the convincingness of epidemiological data in support of their association with disease. We also highlight two other polymorphisms that may affect p53 signaling, but for which functional or association data are still forthcoming (KITLG and ANRIL). Finally, we touch on three questions regarding genetic modifiers of the p53 pathway: Why did these variants arise? Were they under selection pressure? And, is there compelling evidence to support genotyping these variants to better predict disease risk and prognosis?