Hyperglycemic Conditions Proliferate Triple Negative Breast Cancer Cells: Role of Ornithine Decarboxylase [post]

Surabhi Chandra, Caleb C. Capellen, Jose A. Ortega, M. Jane Morwitzer, Hadassha Tofilau, Matthew Dunworth, Robert A. Casero
2021 unpublished
Several cancer subtypes (pancreatic, breast, liver, and colorectal) rapidly advance to higher aggressive stages in diabetes. Though hyperglycemia has been considered as a fuel for growth of cancer cells, pathways leading to this condition are still under investigation. Cellular polyamines can modulate normal and cancer cell growth, and inhibitors of polyamine synthesis have been approved for treating colon cancer, however the role of polyamines in diabetes-mediated cancer advancement is unclear
more » ... as yet. We hypothesized that polyamine metabolic pathway is involved with increased proliferation of breast cancer cells under high glucose(HG) conditions. Studies were performed with varying concentrations of glucose (5mM-25mM) exposure in invasive, triple negative breast cancer cells, MDA-MB-231; non-invasive, estrogen/progesterone receptor positive breast cancer cells, MCF-7; and non-tumorigenic mammary epithelial cells, MCF-10A. There was a significant increase in proliferation with HG (25mM) at 48-72h in both MDA-MB-231 and MCF-10A cells but no such effect was observed in MCF-7 cells. This was correlated to higher activity of ornithine decarboxylase (ODC), the rate limiting enzyme in polyamine synthesis pathway. Inhibitor of polyamine synthesis (difluoromethylornithine, DFMO, 5mM) was quite effective in suppressing HG-mediated cell proliferation and ODC activity in MDA-MB-231 and MCF-10A cells. Polyamine (putrescine) levels were significantly elevated with HG treatment in MDA-MB-231 cells. HG exposure also increased the metastasis of MDA-MB-231 cells. Our findings are the first to indicate that polyamine inhibition can improve prognosis of breast cancer patients with diabetes, and also prevent proliferation of normal breast epithelial cells, which could potentially become tumorigenic.
doi:10.21203/rs.3.rs-520490/v1 fatcat:7ji5m57fzngllfypkrtsinajx4