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Abstract
Sphingolipids are key components of the plasma membrane and are regulators of complex biological processes often altered in cancer cells. In human tumors, genes of key enzymes that regulate levels of glucosylceramide and lactosylceramide are often amplified. However, it is unknown why these traits are positively selected in transformed cells. In this work, we used CRISPR-Cas9 to knockout two key enzymes amplified in tumors in HeLa and H1703 tumor-derived cell-lines. As expected, the knockout lines had dramatic accumulation of GlcCer and LacCer. However, unexpectedly, they showed significantly decreased in-vitro wound-healing capacity and an almost complete loss of in-vitro extra-cellular matrix invasion. Based on these results, we probed for protein markers of the epithelial-to-mesenchymal transition (EMT). Data showed a significant increase of the levels of E-cadherin and a decrease of N-cadherin, suggesting that knockout cells acquired a more epithelial-like phenotype. Knockout lines also had significant changes in SNAIL levels, an important regulator of E-cadherin expression and EMT marker. As SNAIL can be regulated by growth factor receptors such as EGFR, we probed for global changes in growth factor receptor tyrosine kinase (RTK) activation. Results showed that, compared to their otherwise isogenic wild-type counterparts, knockout lines had broad changes in growth factor RTK activation patterns. The knockout cells also had significant changes in their responses to cytotoxic chemotherapeutic agents. Our work suggests that increased expression of key glycosphingolipid regulating enzymes in transformed cells are critical to promote malignant phenotypes by impacting EMT, sustained activity of growth factor RTKs, and responses to therapy.
Publication Date
2023
Subject Major(s)
Cellular biology, cancer biology
Keywords
Sphingolipids, GBA, glucosylceramide, cancer, EMT
Disciplines
Cancer Biology | Cell Biology
Current Academic Year
Senior
Faculty Advisor/Mentor
Santiago Lima
Rights
© The Author(s)
Recommended Citation
Clark, L., Dickinson, A., & Lima, S. (2023). Cellular glycosphingolipid imbalance modulates EMT in cancer cells. [Symposium]. Undergraduate Research Opportunities Program, Virginia Commonwealth University.