YB-1 Expression Is Associated with Lymph Node Metastasis and Drug Resistance to Adriamycin in Breast Cancer.

Background: Breast cancer (BC) is the most common malignant tumor among females. Although there are multiple treatments for breast cancer, many patients still face the dilemma of drug resistance after multiline treatment. It would be greatly helpful for clinical work to identify additional and improved prognostic predictors. Y-box binding protein-1 (YB-1) is a member of the cold shock protein family, and patients with overexpression of YB-1 have a worse prognosis.

Methods: This study collected 48 specimens from 48 patients with breast cancer and analyzed the clinicopathological characteristics of the patients. Immunohistochemistry, immunofluorescence, cell viability analysis, tumor spheroid formation and cell morphology, cell invasion, cycle analysis, qRT-PCR, Western blot, and tumorigenicity in BALB/c nude mice were performed to verify the results.

Results: We found that patients with overexpression of YB-1 were related to lymph node metastasis and the patients' age tended to be young. Because of the short follow-up time, a survival analysis could not be performed. Based on the results of in vitro and in vivo experiments, this study indicated that breast cancer cells with overexpression of YB-1 had stronger proliferation, migration, and invasion abilities than cells with low expression of YB-1. Compared with cells with low expression of YB-1, the proliferation, migration, and invasion abilities of YB-1 overexpressed cells were not significantly affected by adriamycin.

Conclusion: This suggested that breast cancer cells with overexpression of YB-1 were resistant to adriamycin. Therefore, YB-1 is associated with lymph node metastasis of breast cancer cell. YB-1 could be a prognostic, predictive factor and a novel therapeutic target of BC.