In Vitro and Clinical Studies of Gene Therapy with Recombinant Human Adenovirus-p53 Injection for Malignant Melanoma.

Malignant melanoma is an aggressive tumor with high fatality rates and poor prognosis, mainly due to the lack of efficient treatment methods. The present study investigated the potential antitumor effects of recombinant adenovirus p53 (rAd-p53) on human malignant melanoma. The optimal viral titer on a human malignant melanoma (A-375) cell line was determined for the rAd-p53 treatment. The invasive abilities, apoptosis, variations in the cell cycle, and molecular expression levels of A-375 cells were detected after infection by rAd-p53. A tumor growth curve and hematoxylin and eosin staining were carried out for experiments in nude mice. Twenty-one patients with malignant melanoma were evaluated, including 12 cases without gene therapy and nine cases with rAd-p53 gene therapy. The overall survival rate and the median survival time were analyzed between the two groups of patients. When the multiplicity of infection was 100, the cells showed the best transfection efficiency. The invasive ability, apoptosis, cycle changes of the cells, and the expression of the p53, p21, and Bax genes and proteins were significantly changed in the experimental group. In nude mice, the tumor growth curve and the tumor size in the experimental group were significantly smaller than those of the control group. Hematoxylin and eosin staining revealed tumor metastasis in the blank group and the control group but not in the experimental group. Between the two groups of patients, the median survival of the gene therapy group (38 months) was greater than that of the group without gene therapy (27 months). In this study, high expression of the p53 gene could regulate the gene expression and reduce the invasive and metastatic abilities of the tumor cells. Furthermore, rAd-p53 effectively improved the survival of patients with malignant melanoma. Therefore, rAd-p53 may be a potential treatment method for human malignant melanoma.