A proteomic approach links decreased pyruvate kinase M2 expression to oxaliplatin resistance in patients with colorectal cancer and in human cell lines

Abstract

We aimed to gain further understanding of the molecular mechanisms involved in oxaliplatin resistance in colorectal cancer by using a proteomic approach. A 5-fold oxaliplatinresistant cell line, HTOXAR3, was compared with its parental cell line, HT29, using two-dimensional PAGE. Mass spectrometry, Western blot, and real-time quantitative PCR confirmed the down-regulation of pyruvate kinase M2 (PK-M2) in HTOXAR3 cells. In a panel of eight colorectal cancer cell lines, we found a negative correlation between oxaliplatin resistance and PK-M2 mRNA levels (Spearman r = −0.846, P = 0.008). Oxaliplatin exposure in both HT29 and HTOXAR3 led to PK-M2 mRNA up-regulation. PK-M2 mRNA levels were measured by real-time quantitative PCR in 41 tumors treated with oxaliplatin/5-fluorouracil. Tumors with the lowest PK-M2 levels attained the lowest response rates (20% versus 64.5%, P = 0.026). High PK-M2 levels were associated with high p53 levels (P = 0.032). In conclusion, the data provided clearly link PK-M2 expression and oxaliplatin resistance mechanisms and further implicate PK-M2 as a predictive marker of response in patients with oxaliplatintreated colorectal cancer. [Mol Cancer Ther 2009;8(4): 771-8]

Down-regulation of Ras-related Protein Rab 5C-dependent Endocytosis and Glycolysis in Cisplatin-resistant Ovarian Cancer Cell Lines

“…This is consistent with an earlier report showing that ALDO and PGK are downregulated in drug-resistant cells (32). The other proteomic study has also linked the decreased pyruvate kinase M2 expression to oxaliplatin resistance in patients with colorectal cancer, showing tumors with the lowest PKM2 levels attain the lowest oxaliplatin response rates and the high PKM2 levels are associated with high p53 levels (44). In the present study, the expression level of PKM in A2780-DR cells was about half of that in A2780 cells (Table III) by quantitative proteomic analysis.…”

“…As a key enzyme for cancer metabolism and tumor growth, PKM2 and other glycolytic enzymes were found to be up-regulated in most cancer cells (45)(46)(47). However, our results and previous studies have shown that down-regulation of glycolytic enzymes are a characteristic of drug-resistant ovarian cancer and colorectal cancer cells (32,44). Although the molecular events leading to down-regulation of glycolytic enzymes are still not clear, we have found that expression levels of c-Myc and HIF1A are down-regulated in drug-resistant cells.…”

Proteomic analysis of ubiquitination-associated proteins in a cisplatin-resistant human lung adenocarcinoma cell line

“…A previous study revealed a negative correlation between the expression level of PKM2 and the level of drug-resistance of tumors, and the expression level of PKM2 in A549/CDDP cells was lower than that in A549 cells. The sensitivity of A549 cells to CDDP decreased dramatically, and the drug-resistance increased markedly after the inhibition of PKM2 expression in A549 cells (22)(23)(24), in agreement with the results of this study.…”

Knockdown of PKM2 Enhances Radiosensitivity of Non-small cell Lung Cancer

“…Red label stands for TUNEL positive and DAPI was used for counter stain; b Apoptosis and ER stress genes probe by western blot (Color figure online) Cell Biochem Biophys resistance and radioresistance are controversial. In one side, several studies showed a negative correlation between PKM2 expression and drug resistance [21][22][23]: Decreased PKM2 protein activity is linked to cisplatin resistance, while suppression of PKM2 expression by siRNA increased cisplatin resistance. Both PKM2 mRNA and protein levels are down-regulated in oxaliplatin-resistant cells, and PKM2 mRNA levels are inversely correlated with oxaliplatin resistance in a panel of eight colorectal cancer cell lines.…”