Characterization of Small Genetic Variants in Breast Cancer Cell Line Under Tamoxifen Therapy

Background: Tamoxifen (TAM) is an effective hormone therapy that reduces the risk of cancer recurrence. According to evidence, TAM contributes to the alterations of genetic variants back-ground and plays a role in the effectiveness of treatments via alteration of the genetic variants. The effects of TAM on genomic features were investigated in the current study by discovering genet-ic variants and finding the answer to the following question: "Is there any association between the alterations of genetic variants under TAM consumption and an effective treatment process?" Materials and Methods: Whole-transcriptome (RNA-seq) dataset from four in-vestigations including 10 TAM-treated samples and 9 untreated samples as the con-trol groups were derived from European Bioinformatics Institute (EBI). Using the process of variants calling, the differential genetic variants between and gene on-tology enrichment analysis were detected by CLC Genomics Workbench (12). Results: Current study reported about 5.8 million genetic variants. The outcomes of the chi-square test showed that distributions of genetic variants between control and treated samples were significant (p<0.05). The genetic variants comparison between the control and TAM -treat-ed samples indicated that there were 67 differential genetic variants. Gene ontology enrich-ment analysis indicated that differential genetic variants were associated with several tumor suppressors and oncogenes including IL6ST, GEN1, FNTA. HSPA5, NSMCE2, and DDX11. Conclusion: Most of the candidate genes with different genetic variants had dual roles as oncogenes or tumor suppressors. Therefore, it can be argued that TAM does not play a significant role in an effective treatment through alteration of the genet-ic variants. In other words, it cannot be concluded that the TAM therapy-resulted al-terations of genetic variants play a positive or negative role in the treatment process. [GMJ.2023;12:e2598] DOI:10.31661/gmj.v12i0.2598