¹Laboratory of Macromolecular Engineering, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universitas Gadjah Mada Sekip Utara II, 55281 Yogyakarta, Indonesia
²Cancer Chemoprevention Research Center, Faculty of Pharmacy, Universitas Gadjah Mada Sekip Utara II, 55281 Yogyakarta, Indonesia
³Laboratory of Advanced Pharmaceutical Sciences. Faculty of Pharmacy, Universitas Gadjah Mada Sekip Utara II, 55281 Yogyakarta, Indonesia DOI : 10.29228/jrp.2022.00 Epigenetic alterations in regulatory genes, genetic factors, and genomic instability, which cause breast cancer, can also contribute to disease resistance. HORMAD , which encode proteins containing HORMA domains and are involved in homologous recombination, have important roles in cancer emergence and progression. In this study, we uncovered putative breast cancer therapeutic targets by examining HORMAD1 and HORMAD2 genetic and epigenetic alterations. mRNA levels of HORMAD1 and HORMAD2 in breast cancer samples and normal breast tissues, as well as mRNA levels in normal, breast cancer, and metastatic breast cancer samples, were analyzed using TNMplot. Prognostic value, genetic alterations, epigenetic alterations, genetic variations, ROC plots, functional prediction, and immune infiltration of HORMAD1 and HORMAD2 were conducted with KMPlotter, cBioportal, methsurv, ClinVar, ROC Plotter, PredictSNP, PANTHER, and TIMER 2.0, respectively. Both HORMAD1 and HORMAD2 mRNA levels were lower in breast cancer samples, and lower in metastatic breast cancer samples. Patients expressing higher HORMAD1 and HORMAD2 levels had favorable overall survival (OS) rates than the opposite groups. HORMAD1 and HORMAD2 gene amplifications and deletions were also observed. Pathway enrichment analyses showed that Wnt signaling alterations contributed to cell proliferation. Increased DNA methylation levels were identified in HORMAD2 when compared with HORMAD1 in patients. Two 1021C>T (Q334) and 430A>G (T144A) variants of HORMAD1 were shown to have clinical significance in patients. Also, functional prediction mutant analysis of HORMAD1 confirmed that S287F exerted a deleterious effect on amino acid impact, however, further investigations are warranted. Receiver operating characteristic (ROC) plot data indicated a significant correlation between HORMAD2 levels and anti-human epidermal growth factor receptor 2 (HER2) sensitivity. Genetic and epigenetic changes in HORMAD1 and HORMAD2 genes may be used as indicators and targets for overcoming breast cancer resistance and limiting metastasis in breast cancer cells via Wnt targeting. Further research is required to verify our findings. Keywords : HORMAD; breast cancer resistance; metastasis; bioinformatics; genetic and epigenetic alterations