Predicting cisplatin response in cholangiocarcinoma patients using chromosome pattern and related gene expression

Cholangiocarcinoma (CCA) is a prevalent bile duct cancer with limited treatment options. Cisplatin-based chemotherapy is a common approach, but response rates vary. Recently, chromosome aberrations have emerged as predictors of chemotherapy response in various malignancies. This study aimed to identify chromosomal aberrations associated with cisplatin response in CCA. A histoculture drug response assay was conducted on 20 fresh CCA tissues to determine cisplatin sensitivity. In parallel, chromosome aberration analysis was performed using chromosome microarray. Using chromosome microarray analysis on 20 CCA samples, we found distinct chromosomal aberration patterns between cisplatin responders and non-responders. Gains in 18q and 20q, and losses in 1p and 8p were more common in non-responders. Conversely, the responders exhibited gains in 8q and losses in 16q. Our heatmap analysis of log-2 ratio demonstrated difference in various chromosomes including 2, 3p, 5q, 6q, 7, 9p, 11q, 14q, 15q, 18q, 20q, and 22q between the response and the non-response to cisplatin. Further analysis using machine learning with random forest model identified genes like NCOA3, TPK1, CEP57L1, DEPDC5, and PLXNA4 as potential predictors of cisplatin response. Validation in a separate cohort of 33 CCA samples confirmed the association of NCOA3 and DEPDC5 with cisplatin response. Our findings suggest that chromosomal aberrations and specific genes may predict cisplatin response in CCA, potentially guiding personalized treatment strategies.