Genotyping, in silico screening and molecular dynamics simulation of SNPs of MGMT and ERCC1 gene in lung cancer patients treated with platinum-based doublet chemotherapy

Assessing the impact of MSH3 and MSH6 polymorphisms on lung cancer risk in North Indian patients undergoing platinum chemotherapy through molecular dynamics simulation

The present study investigated the relationship between MSH3 and MSH6 genes in lung cancer patients. Genotyping of lung cancer patients and healthy controls was performed. Odds ratio values were calculated and survival analysis performed. Patients with mutant genotype (TT) for MSH6 polymorphism have 1.5-fold risk for the development of lung cancer (p = 0.03). For non-smokers, the mutant-type genotype had a threefold increased risk of lung cancer (p = 0.01). Patients administered with docetaxel and carbo/cisplatin and carrying GT genotype for MSH6 polymorphism, patients reported a decrease in median survival time (4.9 vs 9.13 months). MSH3 and MSH6 polymorphisms are involved in modulating the risk towards lung cancer. MSH6 polymorphism is associated with high mortality rate for patients undergoing cisplatin and docetaxel chemotherapy.

Evaluation of mutations on O6-methylguanine methyl transferase structure and its interactions: molecular dynamics simulation study

O6-methylguanine DNA methyl transferase (MGMT) is a significant vehicle for the cellular clearance of alkyl lesions, particularly the methyl group of the O-6 and O-4 positions of guanine and thymine, respectively. Many publications have studied the correlation between polymorphisms in MGMT and susceptibility to various cancers. In the present study, we investigated the consequence of L84F, common single-nucleotide polymorphism, K125E, site-specific mutagenesis, and L84F/K125E on conformation, stability, and behavior of MGMT in the free form and interaction with proliferating cell nuclear antigen (PCNA) and DNA as partners in the biochemical network by using molecular dynamics simulation method. Our results showed that all free variants of MGMT differed from the native form. However, among all free variants of MGMT, the L84F/K125E variant exhibited similar properties compared with the wild-type. In contrast, in complex modes, only amino acid residues of the L84F variant are involved in the interactions with PCNA and DNA somewhat differently relative to the wild-type. Furthermore, L84F SNP showed the highest binding free energy compared to other variants and native forms. These alterations in the amino acids and binding free energy of L84F relative to the native are the reasons for changing its region connection compared to the native form. Therefore, we propose conducting further investigations into the impact of inhibitors or chemotherapeutic agents to assess their effectiveness on MGMT variants compared to the wild-type, aiming to reduce the cost of cancer treatment that will depend on inhibiting native MGMT protein.Communicated by Ramaswamy H. Sarma.