Role of pyruvate kinase type M2 in the migration and invasion of renal cell carcinoma and possible mechanisms

Objective To analyze the alterations of glucose metabolism upon the knockdown of pyruvate kinase type M2 (PKM2) in renal cell carcinoma cell line ACHN, and explore the potential role of PKM2 in migration and invasion of renal cell carcinoma and the possible mechnisms. Methods The pLV lentivirus vector with PKM2-short hairpin RNA (shRNA) was constructed and the stably expressed cell line was generated. The effects of PKM2 knockdown on proliferation of ACHN cells were detected by cell counting kit-8 (CCK-8) assay, migration and invasion ability detected by Transwell assay, and alteration of Warburg effect detected by measuring glucose uptake and lactate production. Western blotting and real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) were performed to examine the expression of E-cadherin and Vimentin after the knockdown of PKM2. Results CCK-8 assay showed that cell viability of shPKM2 group was significantly lower than that in control group. The glucose uptake and lactate production in control group were (3.493±0.179) and (3.553±0.185) nmol/106 cells/min repectively, while those in shPKM2 group were (1.457±0.081) and (5.820±0.352) nmol/106 cells/min (P=0.001, P=0.005). The number of migrating cells in control and shPKM2 groups was 62±6 and 39±5 (P=0.001), and that of invasive cells in control and shPKM2 groups was 40±7 and 26±6 (P=0.009), respectively. The relative expressions of E-cadherin protein and mRNA in shPKM2 group (1.560±0.110 and 2.534±0.342) were higher than that in control group (0.833±0.070 and 1.312±0.284) by Western blotting and RT-qPCR (P=0.001, P=0.009). The relative expressions of Vimentin protein and mRNA in shPKM2 group (0.340±0.110 and 1.631±0.123) were lower than that in control group (0.653±0.100 and 3.530±0.511, P=0.022, P=0.003). Conclusion Knockdown of PKM2 can impair the glucose metabolism and suppress cell proliferation, migration and invasion in vitro and in vivo. Knockdown of PKM2 decreases the expression of Vimentin, and increase the expression of E-cadherin. Key words: Clear cell renal cell carcinoma; Pyruvate kinase type M2; Migration; Invasion; Epithelial-mesenchymal transition