Targeting of Several Glycolytic Enzymes Using RNA Interference Reveals Aldolase Affects Cancer Cell Proliferation through a Non-glycolytic Mechanism

• Published in: The Journal of biological chemistry 2012-12, Vol.287 (51), p.42554-42563
• Main Authors: Lew, Carolyn Ritterson, Tolan, Dean R.
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - metabolism; Animals; Cancer Biology; Carbohydrate Metabolism; Cell Biology; Cell Line; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic - pathology; Cytokinesis; Cytoskeleton; Fructose-Bisphosphate Aldolase - genetics; Gene Knockdown Techniques; Giant Cells - metabolism; Giant Cells - pathology; Glycolysis - genetics; Glycolytic Flux; Humans; Intracellular Space - metabolism; Mice; Models, Biological; Moonlighting; Neoplasms - enzymology; Neoplasms - pathology; Phenotype; Rats; RNA Interference; RNA, Small Interfering - metabolism; Transfection; Warburg Effect
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M112.405969

In cancer, glucose uptake and glycolysis are increased regardless of the oxygen concentration in the cell, a phenomenon known as the Warburg effect. Several (but not all) glycolytic enzymes have been investigated as potential therapeutic targets for cancer treatment using RNAi. Here, four previously untargeted glycolytic enzymes, aldolase A, glyceraldehyde 3-phosphate dehydrogenase, triose phosphate isomerase, and enolase 1, are targeted using RNAi in Ras-transformed NIH-3T3 cells. Of these enzymes, knockdown of aldolase causes the greatest effect, inhibiting cell proliferation by 90%. This defect is rescued by expression of exogenous aldolase. However, aldolase knockdown does not affect glycolytic flux or intracellular ATP concentration, indicating a non-metabolic cause for the cell proliferation defect. Furthermore, this defect could be rescued with an enzymatically dead aldolase variant that retains the known F-actin binding ability of aldolase. One possible model for how aldolase knockdown may inhibit transformed cell proliferation is through its disruption of actin-cytoskeleton dynamics in cell division. Consistent with this hypothesis, aldolase knockdown cells show increased multinucleation. These results are compared with other studies targeting glycolytic enzymes with RNAi in the context of cancer cell proliferation and suggest that aldolase may be a useful target in the treatment of cancer. Background: Due to renewed interest in the Warburg effect, glycolytic enzymes have garnered interest as therapeutic targets for cancer. Results: Proliferation of transformed cell lines is halted upon aldolase knockdown using RNAi, an effect not seen upon knockdown of other glycolytic enzymes. Conclusion: Aldolase knockdown inhibits proliferation through a non-glycolytic function, likely affecting cytokinesis. Significance: Non-glycolytic aldolase functions represent a new potential target for cancer therapeutics.