The clinical significance between activation of nuclear factor kappa B transcription factor and overexpression of HER-2/neu oncoprotein in Taiwanese patients with breast cancer

Abstract

Background: This study investigated the role of nuclear factor-kappa B (NF-κB) activity in human breast cancer with overexpression of HER-2/neu oncoprotein, as well as its role on expression of different histological grades of cancer cells taken from Taiwanese breast cancer patients. Materials and methods: Specimens were collected from 82 female breast cancer patients. The HER-2/neu oncoprotein was measured by immunohistochemistry. NF-κB activity expression was assessed by the electrophoretic mobility shift assay, and confirmed by the supershift technique using anti-P65 antibody in both breast cancer tissue and the adjacent normal tissue. The histological grades were measured by Modified Bloom–Richardson Grading Scheme. Results: Of the 82 cancer specimens, 81 (98.7%) showed higher or equal expressions of NF-κB activity when compared to the adjacent normal tissue. Fifty-five cases (67.1%) had higher levels of NF-κB activity in the cancerous tissue than in the adjacent normal tissue ( p<0.005). With regard to tumor size, steroid receptors, stages, histological types, and node status, there were no statistically significant differences in NF-κB activity between cancerous tissues and adjacent normal tissues. However, significantly higher expressions of NF-κB activity were seen in those cases with positive HER2/neu oncoprotein, poorly differentiated histological grades, high nuclear pleomorphisms, and high mitotic counts ( p<0.05). Positive HER-2/neu overexpression of oncoprotein had higher NF-κB activity (86%) than negative overexpression (60%) ( p<0.05). It has been shown that the NF-κB activity increases in the HER-2/neu oncoprotein overexpression in human breast cancer. Conclusion: Overexpression of HER-2/neu gene could induce NF-κB activity in human breast cancer cells, as has been confirmed in other research on cell lines.