In vivo comparison of transduction efficiency with recombinant adenovirus-mediated p53 in a human colon cancer mouse model by different delivery routes

Antitumor effects of recombinant human adenovirus-p53 against human cutaneous squamous cell carcinoma in mice

The present study was conducted to identify the anti-tumor effects of rAd/p53, which is a recombinant human serotype 5 adenovirus, in cutaneous squamous cell carcinoma (cSCC). Mouse models of human cSCC were constructed by injecting human cutaneous squamous cell carcinoma cells into both flanks of nude mice. Subsequently, the 75 nude mice with cSCC xenograft tumors were randomly divided into recombinant human serotype 5 adenovirus (rAd)/p53, rAd/p53 + 5-fluorouracil (5-Fu) and 5-Fu groups. One side of the tumors was administered the therapeutic agents as the therapeutic group, whereas the remaining side was treated with medical saline as the control. At 24, 48, 72, 120 and 168 h post-intratumoral injection, alterations in tumor volume, tumor necrosis and the expression of several tumor-associated genes, including Smad4, Brca1 and matrix metalloproteinase (MMP-2), were analyzed. Compared with its control group, the rAd/P53 group exhibited a significantly increased tumor necrosis ratio. In addition, Smad4 and Brca1 expression levels increased significantly at various time points (P<0.05), and MMP-2 expression decreased significantly (P<0.05). In the rAd/p53 + 5-Fu group, the tumor necrosis ratio, and Smad4 and Brca1 expression levels also significantly increased at various time points (P<0.05). MMP-2 gene transcription gradually decreased, high expression of Smad4 was prolonged, and high expression of Brca1 was observed in the early period following treatment compared with the rAd/P53 group. In addition, p53 expression exhibited a positive correlation with the tumor necrosis ratio and Smad4 expression, and showed a negative correlation with MMP-2 gene transcription (P<0.05). These findings indicate that rAd/p53 has a potent anti-tumor effect in cSCC via the promotion of tumor necrosis and regulating the expression of various tumor-associated genes.

Synergistic anticancer effect of rAd/P53 combined with 5-fluorouracil or iodized oil in the early therapeutic response of human colon cancer in vivo

Exogenous wild-type p53 (wt-p53) tumor suppression increases the sensitivity of tumor cells to radiotherapy and chemotherapy. An iodized oil emulsion was used as a p53 vector for intra-arterial gene delivery to treat hepatic tumors. Whether the chemotherapeutic agent or the iodized oil affects exogenous wt-p53 activity remains poorly understood. In the present study, the early therapeutic response of rAd/p53, combined with 5-fluorouracil (5-FU) or with iodized oil, was observed in a human colon cancer model. Allograft models in 82 nude mice with human colon carcinoma SW480 were divided randomly into four groups and administered with physiologic saline, rAd/p53, rAd/p53+5-FU, and rAd/p53+iodized oil by intratumoral injection. At 24, 48, 72, 120, and 168 h after treatment, p53 expression, the Ki-67 index (KI), and the degree of tumor necrosis were assessed. The p53 expression and tumor necrosis in the therapeutic groups were higher than those in the control group. p53 expression reached its peak at 120 h in the rAd/p53 group, at 72 h in the rAd/p53+5-FU group, and at 48 h in the rAd/p53+iodized oil group. The p53 expression in the rAd/P53+5-FU group and the iodized oil group was significantly higher than those in the rAd/P53 group at 24 and 48 h. The results revealed that tumor necrosis is positively correlated with p53 expression. The KI of the rAd/p53+5-FU group increased significantly at 24 h. 5-FU and iodized oil increase the anticancer effect of rAd/p53, and 5-FU combined with rAd/p53 has a synergistic anticancer effect.