In order to explore the new mechanism that obesity worsens the prognosis of breast cancer, we reanalyzed the data about gene expression of normal, overweight, and obese breast cancer patients to explore potential genes and validate its function by clinical and experimental data. The fold change of 15-hydroxyprostaglandin dehydrogenate (HPGD) gene which displayed declining trend with BMI increase was 0.46 in obese versus normal weight patients. HPGD protein was highest expressed in normal weight group and lowest expressed in obese group. The rate of positive lymph nodes was 67% in low expression of HPGD group and 35% in high expression of HPGD group. The recurrence-free survival (RFS) rate and overall survival (OS) rate of 5 years had significant difference between low expression of HPGD group and high expression of HPGD group. Obesity dramatically decreased the RFS rate and OS rate of 5 years. Down regulation of HPGD expression could increase the migration and proliferation ability of breast cancer cell line MCF-7. Taken together, our results indicate that low expression of HPGD may be a reason for poor prognosis of obese breast cancer patients.
Keywords: HPGD; breast cancer; obese; prognosis.