Genetic Mutations in Senegalese Women with Breast Cancer

Document Type : Research Articles

Authors

Genomic laboratory, Department of animal biology, Faculty of sciences and technology, Cheikh Anta Diop university, Dakar, Senegal.

Abstract

Objective: This study aimed to understand the effect of nucleotide mutations and microsatellite locus instability on breast cancer in Senegalese women. Methods: A total of 120 healthy and cancerous tissue samples were analyzed. After PCR/sequencing analysis, the nucleotide variability of two mitochondrial genes (MTCYB and D-loop) and polymorphisms of two microsatellite loci (BAT-25 and BAT-26) were determined. Additionally, structural and correlation analyses were performed between the clinicopathological features and polymorphisms of the genes studied. Result: Multiple variations in MTCYB and the D-loop were identified with much higher frequencies in cancerous tissues. However, MTCYB appeared more affected than the D-loop during carcinogenesis. Regarding the BAT-25 and BAT-26 loci, breast carcinogenesis was associated with instability of these microsatellite loci, with an MSI-H phenotype in 60.71% of tumors. Furthermore, the number of pears and the histological grade impacted patient survival. In addition, mutations at D-loop sites 150 and 152 and BAT-25 stability negatively impacted patient survival. In contrast, BAT-26 instability conferred the advantage of longer post-operative survival. Molecular variance analysis revealed that the clinical heterogeneity of the tumors was a function of the number of invading lymph nodes. Conclusion: This study highlights the high penetrance of mitochondrial mutations in breast cancer in Senegalese women, as well as the predominant role of BAT-25 marker stability and BAT-26 marker instability in breast carcinogenesis. 

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