Cetuximab Enhances the Anti-proliferative Effect of Trastuzumab in ERBB2 Over-expressing Breast Cancer Cells – Preliminary Study

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Klin Onkol 2011; 24(5): 356-360. DOI: 10.14735/amko2011356.

Summary
Background: The tyrosine kinase receptor comprises a subclass of cell surface growth factor receptors. Inhibition of certain members of the Epidermal Growth Factor Receptor (EGFR) family is an effective treatment approach in some cancers. The anti-tumor effects are greater when this approach is combined with inhibition of the ERBB2 receptors. These studies provide novel experimental data demonstrating a significant augmentation of the anti-proliferative effects of monoclonal antibodies (cetuximab and trastuzumab) on human breast carcinoma cell lines with different level of ERBB receptor expression. Materials and Methods: Three breast cancer cell lines, MCF-7, BT-474, and SK-BR-3 were used. These are characterised by different levels of EGFR and/or other ERBB family members. Inhibition of cell growth in response to cetuximab, trastuzumab or their combination was assessed by MTT assay. Results: The breast cancer cell lines differed in their sensitivity to TZ, CTX and their combination. The SK-BR-3 cancer cell line was sensitive to TZ. On the other hand, CTX had no effect on BT-474 or on SK-BR-3 that expressed low levels of EGFR and high levels of ERBB2. Conclusion: Our new experimental data show that the combination of anti-EGF receptor and anti-ERBB2 mAb may inhibit cancer cells expressing both EGF and ERBB2 receptors.

http://dx.doi.org/10.14735/amko2011356

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