Expression of LKB1 tumor suppressor in non-small cell lung cancer determines sensitivity to 2-deoxyglucose.

OBJECTIVE

Targeted therapy promises to improve patient outcome in non-small cell lung cancer. Biomarkers can direct targeted therapy toward patients who are most likely to respond, thus optimizing benefit. A novel agent with antineoplastic potential is the glucose analog, 2-deoxyglucose. 2-Deoxyglucose targets tumor cells, owing to their increased glucose uptake, inhibiting cellular metabolism and inducing energetic stress, resulting in decreased cellular viability. The tumor suppressor LKB1 is activated by energetic stress, and cells that lack LKB1 fail to respond and undergo cell death, suggesting that LKB1-null non-small cell lung cancer may have an increased susceptibility to 2-deoxyglucose. Inasmuch as somatic loss of LKB1 is a frequent event in non-small cell lung cancer, LKB1 expression could be used as a biomarker for directing 2-deoxyglucose therapy in patients with this type of cancer.

METHODS

LKB1-positive and LKB1-negative non-small cell lung cancer cell lines were evaluated for cell viability, markers of apoptosis, and gene expression after 2-deoxyglucose treatment and compared with vehicle control.

RESULTS

LKB1-negative cells treated with 2-deoxyglucose displayed a significant decrease in cell viability compared with LKB1-positive cells. Gene expression profiles of 2-deoxyglucose treated cells revealed changes in apoptotic markers in LKB1-negative cells, correlating with activation of apoptosis. Re-expression of LKB1 prevented 2-deoxyglucose mediated apoptosis, demonstrating the critical role of LKB1 in mediating 2-deoxyglucose toxicity.

CONCLUSIONS

LKB1 loss increases susceptibility to 2-deoxyglucose treatment in non-small cell lung cancer lines, even at low doses. Thus, determination of LKB1 status may help direct therapy to those patients most likely to benefit from this novel approach, making it useful in the treatment of patients with non-small cell lung cancer.