Identification of annexin A13 as a regulator of chemotherapy resistance using random homozygous gene perturbation.

OBJECTIVE: To utilize a powerful new technology for target discovery, Random Homozygous Gene Perturbation (RHGP), and to identify novel targets that cause tumor cells to become chemoresistant. STUDY
DESIGN: RHGP was used to identify and validate genetic changes that cause chemoresistance of tumor cells to Rapamycin.
RESULTS: A series of targets was identified that allowed tumor cells to survive treatment with Rapamycin. We validated these targets and focused on Annexin A13, a target where decreased expression caused tumor cell insensitivity to Rapamycin. Ectopic overexpression of Annexin A13 was likewise sufficient to sensitize malignant breast cancer cells to treatment with Rapamycin.
CONCLUSION: These findings expand our knowledge of mechanisms that allow tumor cell drug resistance and demonstrate the power of RHGP to identify novel targets and mechanisms.