The M2 splice isoform of pyruvate kinase is important for cancer metabolism and tumour growth.

Nature
Authors
Keywords
Abstract

Many tumour cells have elevated rates of glucose uptake but reduced rates of oxidative phosphorylation. This persistence of high lactate production by tumours in the presence of oxygen, known as aerobic glycolysis, was first noted by Otto Warburg more than 75 yr ago. How tumour cells establish this altered metabolic phenotype and whether it is essential for tumorigenesis is as yet unknown. Here we show that a single switch in a splice isoform of the glycolytic enzyme pyruvate kinase is necessary for the shift in cellular metabolism to aerobic glycolysis and that this promotes tumorigenesis. Tumour cells have been shown to express exclusively the embryonic M2 isoform of pyruvate kinase. Here we use short hairpin RNA to knockdown pyruvate kinase M2 expression in human cancer cell lines and replace it with pyruvate kinase M1. Switching pyruvate kinase expression to the M1 (adult) isoform leads to reversal of the Warburg effect, as judged by reduced lactate production and increased oxygen consumption, and this correlates with a reduced ability to form tumours in nude mouse xenografts. These results demonstrate that M2 expression is necessary for aerobic glycolysis and that this metabolic phenotype provides a selective growth advantage for tumour cells in vivo.

Year of Publication
2008
Journal
Nature
Volume
452
Issue
7184
Pages
230-3
Date Published
2008 Mar 13
ISSN
1476-4687
DOI
10.1038/nature06734
PubMed ID
18337823
Links
Grant list
R01 GM056203 / GM / NIGMS NIH HHS / United States
T32 CA009172 / CA / NCI NIH HHS / United States
Howard Hughes Medical Institute / United States