Synergistic combination of flavopiridol and carfilzomib targets commonly dysregulated pathways in adrenocortical carcinoma and has biomarkers of response

Abstract

Drug repurposing is an effective approach to identify active drugs with known toxicity profiles for rare cancers such as ACC. The objective of this study was to determine the anticancer activity of combination treatment for ACC from previously identified candidate agents using quantitative high-throughput screening (qHTS). In this study, we evaluated the anticancer activity of flavopiridol and carfilzomib in three ACC cell lines in vitro and in vivo. Human ACC samples were analyzed for drug-target analysis, and cancer-related pathway arrays were used to identify biomarkers of treatment response. Because flavopiridol is a potent cyclin-dependent kinase (CDK) inhibitor, we found significantly higher CDK1 and CDK2 mRNA expression in three independent cohorts human ACC (p<0.01) and CDK1 protein by immunohistochemistry (p<0.01) in human ACC samples. In vitro treatment with flavopiridol and carfilzomib in all three ACC cell lines resulted in a dose-dependent, anti-proliferative effect, and the combination had synergistic activity as well as in three-dimensional tumor spheroids. We observed increased G2M cell-cycle arrest and apoptosis with combination treatment compared to other groups in vitro. The combination treatment decreased XIAP protein expression in ACC cell lines. Mice with human ACC xenografts treated with flavopiridol and carfilzomib had significantly lower tumor burden, compared to other groups (p<0.05). We observed increased cleaved-caspase expression and decreased XIAP in tumor xenografts of mice treated with combined agents. Our preclinical data supports the evaluation of combination therapy with flavopiridol and carfilzomib in patients with advanced ACC.

Drug repurposing in oncology: Compounds, pathways, phenotypes and computational approaches for colorectal cancer

“…Promptly developing computational approached merging different “-omics” and multi-network multi-layered data sets, will facilitate future repurposing of drugs for multiple oncological indications. As already demonstrated [ 230 , 231 ], repurposing drugs in combination with other agents could potentially improve clinical outcomes in cancer patients.…”

Screening and identification of key biomarkers in adrenocortical carcinoma based on bioinformatics analysis

“…CDK1 serves an important role in regulating cell cycle progression and mediating the phosphorylation of Bcl-2 by binding with cyclin B to form a complex called cyclin B-CDK1 (42). In adrenocortical tumors, CDK1 overexpression is associated with tumor suppressor miR-7 downregulation, which may serve as a target for inhibiting the progression of ACC (43,44). EZH2 was significantly associated with poorer outcomes in ACC (45).…”

GATA3 and APOBEC3B are prognostic markers in adrenocortical carcinoma and APOBEC3B is directly transcriptionally regulated by GATA3

“…Human ACC cell lines H295R and SW13 were purchased from ATTC (Rockville, MD, USA) and were grown in DMEM supplemented with 1% insulin transferrin selenium and 2.5% NuSerum I (Corning, Bedford, MA, USA). The ACC BD140A cell line [ 13 , 36 , 37 ] was kindly provided by Drs. Kimberly Bussey and Michael Demeure (TGen, Pheonix, AZ, USA), it was cultured in RPMI-1640 medium supplemented with 10% FBS, 1% penicillin-streptomycin and 1% L-glutamate (Life Technologies, Grand Island, NY, USA).…”