Cancer

Cell culture and mouse studies suggest inhibiting autophagy could treat breast cancer metastasis arising from dormant tumor cells. In human breast cancer cell lines, autophagy was higher in a dormant cell line than in a proliferative cell line. In the dormant cells, the autophagy inhibitor hydroxychloroquine increased cell death compared with vehicle, whereas in the proliferating cells, the compound had no effect on cell death. In a mouse model of breast cancer that metastasizes to the lung one to three weeks after dormant cell seeding, hydroxychloroquine or shRNA targeting the autophagy regulator ATG7 administered during cell seeding decreased lung tumor burden compared with vehicle or scrambled shRNA, whereas hydroxychloroquine administered one week after cell seeding did not affect lung tumor burden. Next steps could include testing autophagy inhibitors in other metastatic breast cancer models.

VG Life Sciences Inc. has hydroxychloroquine (HCQ) in Phase I testing to treat ovarian cancer and solid tumors...