Submission ID 93303

Poster Code HR-P-83
Abstract Submission Clinical literature shows that high expression of calpain-1/2 correlates with poor survival in breast cancer. Proteolytic cleavage of calpain-1/2 substrates in cancer is known to affect cell survival signaling, migration, invasion, and sensitivity to chemotherapeutics. Therefore, we hypothesized that genetic abrogation of calpain-1 and/or calpain-2 activity will make MDA-MB-231 human triple-negative breast cancer (TNBC) cells less motile, more sensitive to chemotherapeutic challenges, and will reduce their tumorigenic and metastatic potential. We developed a panel of CAPN1, CAPN2, and CAPNS1 genetic knock-out and lentiviral add-back MDA-MB-231 cell lines. We showed that we can successfully abrogate/restore calpain expression and activity. We demonstrate a phenotype of diminished cell migration in vitro, induced by calpain-1 deficiency through CAPN1 or CAPNS1 knock-out and rescued by the respective add-back. We also demonstrate reduced metastatic potential of these calpain-deficient TNBC cells in a mouse orthotopic engraftment model, while growth of a primary tumor is unaltered. To develop a pharmacological approach to induce the above-mentioned phenotypes, we developed a split NanoLuciferse reconstitution biosensor to measure the PEF-PEF interactions in calpain-1/2 and to screen for single amino acid substitutions that can disrupt the PEF-PEF dimerization that would be indicative of potential small-molecule binding sites. With the biosensor, we have demonstrated differences in PEF-PEF interactions of CAPN1/2 with CAPNS1, and we have employed these biosensors in an in vitro and an in silico high-throughput screening campaign with the eventual goal of developing allosteric isoform-specific inhibitors of calpain-1 and calpain-2 for in vivo applications. P.G. holds a Canadian Institutes of Health Research (CIHR) grant that supports the above-mentioned research, and I.Sh. is a recipient of The Canada Graduate Scholarships - Doctoral (CGS D).
Please indicate who nominated you Queen's University, Dept Pathology and Molecular Medicine
What Canadian Institutes of Health Research (CIHR) institute is your research most closely aligned? Cancer Research
What Canadian Institutes of Health Research (CIHR) pillar of health research does your research fall under? Biomedical
PDF of abstract ISh_CSHRF_2023_Abstract.pdf
2023-02-13 at 12:40:20
Presenter and Author(s) Ivan Shapovalov
Ivan Shapovalov
Yan Gao
Kazem Nouri
Peter Greer

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