Granulocyte Colony-Stimulating Factor Enhances the Anticancer Effects of Cisplatin against Lung Cancer by Promoting Angiogenesis

The G-CSF is used as a therapeutic drug of the febrile neutropenia in lung cancer chemotherapy, however, there were few reports that showed the effects of combination effects of G-CSF and anticancer drugs against lung cancer. In the present study, we investigated the effects of G-CSF and the combination effects of G-CSF and cisplatin on lung cancer growth. We investigated the effect of G-CSF against the LL-2 and KLN-205 cells by MTT assay and tried to detect the G-CSF receptor by RT-PCR. Next, to analyze the G-CSF effects in vivo, we transplanted the LL-2 into C57BL/6 mice, intraperitoneally administered G-CSF (30 micro/kg/day) with or without cisplatin (5 mg/kg), measured the tumor size and analyzed pathologically by HE and immunostaining. In vitro analyses, G-CSF showed no effects in LL-2 and KLN-205 cells, and RT-PCR revealed no G-CSF receptor mRNA. In vivo analyses, G-CSF alone did not significantly suppress tumor growth. However, concurrent G-CSF administration with cisplatin significantly enhanced the tumor suppressing effect of cisplatin in early stage of tumor growth. The analysis data of vWF immunostaining indicated that the neovascularization in the peripheral region of the tumors was more enhanced in G-CSF treatment mice. ELISA assay revealed that G-CSF did not influence the serum concentration of TNF-alpha and IL-12 in tumor-bearing mice. This study suggests that concurrent (combination) administration of cisplatin with G-CSF is a safe and effective method for enhancing anticancer effects and reducing chemotherapeutic agent-induced myelosuppression.