Researchers have identified Capn4 as a potential prognostic marker for patients with ovarian cancer.
Ovarian cancer is a common gynaecological cancer that is associated with several risk factors such as increasing age, early menarche or late menopause, and BRCA1 or BRCA2 mutations. Like many other types of malignancy, ovarian cancer progresses through processes that include initiation, local progression and metastasis. Women are often diagnosed at a late stage due to the location of tumours in the pelvis.
Calpain is a highly conserved family of calcium-dependent, non-lysosomal cysteine proteases that selectively catalyze the proteolysis of many specific substrates involved in various cell processes, including motility, proliferation and apoptosis. Capn4 is a small regulatory subunit of the calpain proteolytic system and plays an essential role in maintaining calpain-1 and calpain-2 stability and activity.
Researchers at The First Affiliated Hospital of Nanchang University in China investigated the expression of Capn4 in 113 ovarian cancer and 35 non-tumour tissue samples using quantitative real-time polymerase chain reaction. This study led by Dr. Ming-Fang Yang found that Capn4 expression was significantly upregulated in ovarian cancer tissues compared with non-tumour tissues and was positively correlated to FIGO stage, tumour grade and distant metastasis of ovarian cancer. Kaplan-Meier analysis indicated that patients with high Capn4 expression had shorter overall survival and progress-free survival. Moreover, univariate Cox regression analysis demonstrated that Capn4 overexpression was an unfavourable prognostic factor for ovarian cancer.
The results from this study suggest that Capn4 could serve as a novel prognostic biomarker for ovarian cancer. However, this study has limitations because researchers did not explore the precise mechanism by which Capn4 affects prognosis and outcome in ovarian cancer patient. Further experiments in cell and animal models of ovarian cancer are needed to understand biological processes regulated by Capn4 in ovarian cancer progression.