Knockdown of PPARδ Induces VEGFA-Mediated Angiogenesis via Interaction With ERO1A in Human Colorectal Cancer

MicroRNA-218-5p affects lung adenocarcinoma progression through targeting endoplasmic reticulum oxidoreductase 1 alpha

Lung adenocarcinoma (LUAD) severely threatens the health of people owing to its lethality. Nonetheless, the underlying mechanisms on LUAD development remain unclear to a great extent. This work aimed to probe the functions of miR-218-5p in LUAD. MiR-218-5p and endoplasmic reticulum oxidoreductase 1 alpha (ERO1A) were screened as differently downregulated and upregulated RNAs in LUAD, respectively, by bioinformatics analyses. The results of cell functional assays stated that enforced expression of miR-218-5p notably restrained cell viability, invasion, and migration in LUAD. MiR-218-5p may interact with 3’-untranslated region of ERO1A mRNA as analyzed by bioinformatics. Afterward, western blot and dual-luciferase reporter gene analyses were introduced to identify their interaction. ERO1A overexpression reversed the suppressive impacts of miR-218-5p on LUAD cell progression, indicating the implication of miR-218-5p/ERO1A axis in suppressing cancer development. We also observed that this regulatory axis suppressed angiogenesis in LUAD. Taken together, miR-218-5p/ERO1A axis exerted an imperative role in LUAD cell progression, which provides a valuable clue for the development of LUAD therapeutic regimen.

Hyperglycemic conditions proliferate triple negative breast cancer cells: role of ornithine decarboxylase

PURPOSE

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 as yet. We hypothesized that polyamine metabolic pathway is involved with increased proliferation of breast cancer cells under high glucose (HG) conditions.

METHODS

Studies were performed with varying concentrations of glucose (5-25 mM) 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.

RESULTS

There was a significant increase in proliferation with HG (25 mM) at 48-72 h 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), a rate-limiting enzyme in polyamine synthesis pathway. Inhibitor of polyamine synthesis (difluoromethylornithine, DFMO, 5 mM) 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.

CONCLUSIONS

Our cellular findings indicate that polyamine inhibition should be explored in patient population as a target for future chemotherapeutics in diabetic breast cancer.