Experimental studies on ErbB targeted therapy in malignant melanoma

Abstract: Malignant melanoma has one of the fastest increasing incidences among the different types of cancer in the Western world. This raise can partly be ascribed to the change in sun habits that has taken place during the last decades, since the major external risk factor for melanoma is exposure to ultraviolet radiation. In the case of patients with early stages of melanoma, the prognosis is usually good and the disease may be cured by surgery alone. However, with conventional anti-cancer treatments, patients diagnosed with unresectable or metastatic melanoma have a very low 5-year survival rate ranging from less than 10 percent to about 20 percent, depending on the location and extent of metastatic spread. Despite the development of novel promising targeted drugs, such as the immunomodulating antibody ipilimumab and the B-raf inhibitor vemurafenib, that have been shown to significantly extend patient survival, there is still an urgent need for new and improved treatment strategies which can further increase the survival of patients with advanced malignant melanoma.The aim of this thesis was to investigate the anti-tumor effect of two different tyrosine kinase inhibitors (TKIs), gefitinib and canertinib, on human malignant melanoma cell lines with wild-type BRAF and NRAS. We investigated the effect of these two drugs on cell proliferation, survival and on the ErbB1-4 receptor phosphorylation, as well as the downstream signaling molecules Akt, Erk1/2 and Stat3. We also established a melanoma cell line resistant to gefitinib treatment and studied the resistance mechanisms developed by the cells.The aim of this thesis was to investigate the anti-tumor effect of two different tyrosine kinase inhibitors (TKIs), gefitinib and canertinib, on human malignant melanoma cell lines with wild-type BRAF and NRAS. We investigated the effect of these two drugs on cell proliferation, survival and on the ErbB1-4 receptor phosphorylation, as well as the downstream signaling molecules Akt, Erk1/2 and Stat3. We also established a melanoma cell line resistant to gefitinib treatment and studied the resistance mechanisms developed by the cells.In conclusion, gefitinib and canertinib display promising anti-tumor effects on ErbB-expressing malignant melanoma and might be used in future studies in combination with conventional chemotherapy or other targeted therapies in the treatment of malignant melanoma patients not harboring BRAF or NRAS mutations.