Metabolic synergy of breast cancer cells with tumor microenvironment: Interactionof breast cancer cells with normal fibroblasts, cancer-associated fibroblasts andadipocytes in vitro

Abstract

Tumor microenvironment (TME) plays an important role on the progression and metastasis of tumors because of metabolic coupling and interaction between nonmalignant cells in the TME and cancer cells. We have investigated the role of cancer associated fibroblasts (CAF), normal fibroblasts (NF) and adipocytes on the growth ofbreast carcinoma cells in vitro. Additionally, the anti-glycolytic effects of supercritical CO extract of mango ginger (Curcuma amada Roxb) (CA) on both conventional and 2 reverse Warburg effects were studied in the monocultures of CAF (CAF-05), NF (CCL-110), adipocytes (HPAd) and breast cancer (MCF-7) cells and co-cultures of breast cancer cells with CAFs, NF and HPAd. CA was highly cytotoxic to CAF-05 and MCF-7 cell lines compared to CCL-110 and HPAd cell lines. CA inhibited ATP synthesis in monocultures and co-cultures, though the rate of inhibition is higher in co-cultures than MCF-7 monoculture. Although non-malignant cell lines (CAF-05, CCL-110 and HPAd) have lower levels of lactate synthesis than MCF-7 cells, inhibitory effect of CA is more pronounced in co-cultures of MCF-7 with CAF-05, CCL110 and HPAd cells, respectively than MCF-7 cells alone. Gene expression studies showed that although transcripts of glycolysis-associated genes HIF-1á, MCT1, MCT4, Caveolin-1 and GLUT1 were present in non-malignant monocultures, protein translation of these genes were absent. Treatment of co-cultures of MCF-7+CAF-05 and MCF-7+HPAd cells with supercritical CO extract of mango ginger [Curcuma amada Roxb. (CA) - 5 g/ml] down 2 regulated MCT1, MCT4, and Caveolin-1 proteins. CA treatment also inhibited HIF-1á and GLUT1 protein expression in co-cultures of MCF-7+HPAd cells. These results indicate that CA inhibits both Warburg and reverse Warburg effects in TME.