多药耐药结直肠癌细胞的代谢组学特征

Colorectal cancer is one of the deadliest cancers with almost 50,000 deaths each year in the US. Many of the deaths are due to a serious issue of multidrug resistance (MDR) where the cancer cells are unaffected by chemotherapy resistance. The use of metabolic profiling in MDR cancer cells may be useful for identifying weaknesses in the cells. This study analyzes the metabolomic profiles of colorectal cancer cell lines that were treated for a long-term with chemotherapy medication and a non-chemotherapy drug. We treated the colorectal cancer cell lines with medications for approximately 3-4 months and monitored drug resistant markers through expression analysis using qPCR. Once the markers were confirmed using RNASeq and western blots, the cells analyzed for Biolog Phenotype Mammalian Microarray 1 (PM-M1) to assess the metabolic profile of the drug-resistant colon cancer cells. The PM-M1 assay allowed us to evaluate the production of NADH in the presence of different carbon-based energy sources, providing functional information on the major energy pathways of the cells. Other PM-M assays helped to identify and validate possible trends pathways such as glycolysis and major energy sources. Exposing the cells to atorvastatin (10 and 40 µM), the chemotherapeutic drug doxorubicin (positive control), or untreated/DMSO (negative control) resulted in the overexpression of ABCB1 by the 5 th month of the study with bi-weekly treatments of the medication. The protein analysis with western blots and RNASeq analysis confirmed the expression of the transporter. Comparison of the NADH levels from the cells exposed to DMSO (negative control) to the ones from the cells exposed to doxorubicin (positive controls), we noted 21 compounds showing differences. The cells exposed to atorvastatin showed dose-dependent trends: the NADH levels observed with the 10 µM dose showed very few differences when compared to both DMSO- and doxorubicin-treated cells, while the ones with the 40 µM dose were significantly decreased, with lower NADH levels than both DMSO- and doxorubicin-treated cells in about one third of the PM-M1 wells. Overall, our experiments confirmed that the MDR cancer cells in the doxorubicin and 10 µM atorvastatin, showed very little difference from the negative control in metabolic profiling, while the 40 µM atorvastatin-treated cells caused a drastic reduction of energy production, with deleterious effects on compounds encompassing various metabolic pathways. In conclusion, this study provides a promising approach, both alone and in combination with molecular tools by exploring potential biomarkers and molecular targets for treatment development. These results provide insight into how selective pressures through medication can cause the cells to still be able to slowly develop back to the original metabolic levels once they are resistant to the drug.