Research On Effect Of Recombinant Human Basic Fibroblast Growth Factor On Tumor Genesis And Development

Aims: To investigate the effect of recombinant human basic fibroblast growth factor (rh-bFGF) on the process of tumor genesis and development in vivo and in vitro. Methods: MTT assay was utilized to estimate the effect of rh-bFGF on stimulating the growth of human-derived tumor cells in vitro. In order to investigate the possible mechanism of rh-bFGF to stimulate tumor cell抯 proliferation fundamentally. We have studied the effects of rh-bFGF on the cell cycle of human stomach cell lines (BGC-823) and the apoptosis of BGC-823 cells induced by cisplatin via flow cytometry and optical microscopy. According to the requirements of ICH about preclinical safety evaluation of biotechnology-derived pharmaceuticals, we have also detected the expression level of FGFR- I in cultured cells and tissues of normal epidermis from Kunming strain mice, of transplanted tumor in nude mice and of two-stage experiment induced papillary tumor in skin of Kunming strain mice by western-blot and immunohistochemistry. And meantime we detected the neutralizational antibody of bFGF in mice serum by ELISA after rh-bFGF was continuously injected subcutaneously. The expression of FGFR- I and bFGF was estimated after rh-bFGF is administrated in alt tumor tissues. We observed the effect of rh-bFGF injected subcutaneously on malignant tumor transplanted into nude mice in vivo. By the model of two-stage skin carcinogenesis induced papillary tumor, we observed the effect of rh-bFGF administration with different concentration, different duration and different time. Results: 1) rh-bFGF can stimulate the growth of human tumor cell lines (A549.. BGC-823, HCT% HepG2,. KB, KCC-853, MKN-45, SGC-7901) with the minimum EC5O value at 32.46pg/ml (A549) and the maximal EC5O value at 1.256ng/ml (KB). 2) rh-bFGF lng/ml can significantly increase the ratio of BGC-823 cells during S phase and inhibit it's apoptosis induced by cisplatin. 3) the expression of FGFR- I was found in all of cultured cells and in the tissues of normal epidermis from Kunming strain mice, of transplanted tumor in nude mice and of induced papillary tumor in skin of Kunming strain mice by two-stage carcinogenesis experiment with molecular weight 1 OOkD in malignant cells, whereas 1 2OkD in the tissues of epidermis from natural Kunming strain mice. There is significant difference in site or degree of FGFR- I expression between the tissues of normal epidermis from Kunming strain mice and induced papillary tumor tissues. On the other hand, there is no significant difference in site or degree of FGFR- I expression between induced papillary tumor tissues and transplanted tumor tissues after rh-bFGF was administrated. 4) It was not found that rh-bFGF stimulated the growth of grafted tumor in nude mice. 5) Neutralization antibody was not produced in the serum of mouse after rh-bFGF was injected subcutaneously one time per day for 40 days. 6) rh-bFGF had no effect on the damage of DNA at the stage of tumor initiation; At the stage of tumor promotion, rh-bFGF can raise the ratio of tumor formation and tumor number per mouse, but there is no significant difference. At the early stage of tumor promotion, rh-bFGF high dose (120 i, glkg) and several times for administration can remarkably enhance tumor development promoted by croton oil. With croton oil, rh-bFGF can significantly increase the tumor number per mouse depending on dosage, times, and initiative time of of rh-bFGF administration. The tumor number per mouse after typical two-stage skin carcinogenesis experiment is...