Examining CASC5 Expression in Urinary Bladder Cancer

By GU Oncology Now Editors - Last Updated: January 14, 2022

According to a report, published in Drug Discoveries & Therapeutics, current understanding of cancer susceptibility candidate 5 (CASC5) expression and its clinical significance in human urinary bladder cancer (UBC) is lacking. Lead author Pankaj Kumar Singh and colleagues assessed the diagnostic potential of CASC5, as well as its mRNA and protein expression pattern, and found that CASC5 was overexpressed in patients with UBC compared to control patients with benign prostatic hyperplasia (BPH).

Further, the study’s authors concluded that CASC5 in UBC is potentially a member of the cancer-testis gene family, which is defined by elevated expression in the presence of malignant cancers.

The investigators used quantitative real time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) to evaluate the expression profile of CASC5 in patients with UBC. They observed overexpression of CASC5 in mRNA in testis tissue and a relatively high frequency of CASC5 mRNA in UBC tissues (59.2%; 45 of 76). The CASC5 mRNA relative expression was also found to be significantly higher in muscle-invasive versus non-muscle-invasive tumor tissues (12.26 ± 9.53 vs. 4.64 ± 2.50; p = 0.005).

Regarding CASC5 protein patterns, overexpression was seen in 67.7% (44 of 65) patients with UBC, but not in control samples from patients with BPH. The authors highlighted the additional finding that CASC5 protein expression was also significantly associated with a habit of cigarette smoking in patients with UBC (p < 0.001).

Ultimately, the authors concluded that CASC5 mRNA and protein expression profiles were potentially relevant tools for diagnostic management of patients with UBC. Further, the identification of the cancer-testis gene family characteristics of CASC5 could signal it as a “productive target for peptide vaccines development specifically in [bladder cancers].” However, the authors acknowledged that larger prospective trials are needed to validate their study’s findings.