Related Experiment Video
Updated: Feb 2, 2026

Measuring Calpain Activity in Fixed and Living Cells by Flow Cytometry
Published on: July 8, 2010
Calpain system protein expression and activity in ovarian cancer
Siwei Zhang1, Suha Deen2, Sarah J Storr1
1Academic Clinical Oncology, Nottingham Breast Cancer Research Centre, School of Medicine, University of Nottingham, Nottingham University Hospitals NHS Trust, City Hospital Campus, Nottingham, NG5 1PB, UK.
Purpose:
Expression of members of the calpain system are associated with clinical outcome of patients with, amongst others, breast and ovarian cancers, with calpain-2 expression in ovarian cancer being implicated in chemo-resistance and survival. This study aimed, using a large patient cohort and in vitro models, to verify its importance and further investigate the role in ovarian cancer chemoresponse.
Methods:
Calpain-1, calpain-2, calpain-4 and calpastatin expression were evaluated in primary ovarian carcinomas (n = 575) by immunohistochemistry. Protein expression was assessed, via western blotting, in five ovarian cancer cell lines with various sensitivities towards cisplatin/carboplatin. In vitro calpain activity was inhibited by calpeptin treatment to assess changes in platinum sensitivity by proliferation assay, with expression of genes associated with epithelial-mesenchymal transition being examined by RT2 Profiler™ PCR Array.
Results:
The current study confirmed previous data that high calpain-2 expression is associated with poor overall survival (P = 0.026) and that calpain-1 was not associated with overall survival or progression-free survival. Low expression of calpastatin (P = 0.010) and calpain-4 (P = 0.003) were also associated with adverse survival. Such prognostic associations do not seem to be linked with altered tumour sensitivity towards platinum-based chemotherapy. Interestingly, low calpain-1 expression was more frequent in patients with confined tumours (stage 1) (χ2 = 11.310, df = 1, P = 0.001). Calpain and calpastatin expression varied among ovarian cancer cell lines yet their expression levels were similar between chemo-sensitive cells and resistant counterparts. Moreover, calpeptin treatment did not alter cellular response to platinum-based chemotherapy or epithelial-mesenchymal transition-related gene expression.
Conclusions:
The conventional calpains and calpastatin have been confirmed to play an important role in ovarian cancer; however, the precise mechanisms whereby they exert effects remain to be elucidated.
Related Concept Videos
Activation and Inactivation of G Proteins
Chromatin Position Affects Gene Expression
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the...
Ovarian Cycle
What is Gene Expression?
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...
Co-activators and Co-repressors
Regulation of Expression Occurs at Multiple Steps
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...

