Objective: It is generally accepted that bFGF is an important molecule that involved with proliferation, apoptosis, angiogenesis, invasion and metastasis.bFGF and its receptor (FGFR1) are often found over-expressed in melanoma, lung cancer and breast cancer.Recent studies indicate bFGF expression is closely related with tumor lymph node metastasis and poor prognosis.Treatment of tumor cells with chemotherapy drugs could result in a substantial increase in the production of bFGF.Irradiation might induce tumor cells releasing cell growth factor bFGF.Inhibition of vascular endothelial growth factor (VEGF) appears to stimulate bFGF level.Also,bFGF could participate the process of epithel(i)al-mesenchymal transition.It suggested bFGF might be potential marker for resistance of cancer chemotherapy, radiotherapy and molecular target treatment.Focused on bFGF key role in individual molecular diagnosis, carcinogenesis and cancer prognosis, we have conducted bFGF-targeted therapy research and developed new monoclonal antibody targeting bFGF (anti-bFGF mAb) which neutralizes bFGF, blocking its ability to activate FGFR1 in treating solid tumors.However, the underlying mechanism is largely unknown.Therefore, the antitumor, antiangiogenesis, antimetastatic and reversal multidrug resistance (MDR)activities of anti-bFGF mAb could be investigated.The effectiveness in combination with standard therapeutic schedules and pharmacokinetic profile of anti-bFGF mAb in cancer will be established in this study.Methods: The effect of anti-bFGF mAb on the proliferation of cancer cells was detected by CCK-8 method.Cellular apoptosis, cell cycle distribution and the expression of associated protein were analyzed by flow cytometry.TUNEL staining was used to detect the apoptosis rate of transplanted tumors.Immunohistochemical staining was used to examine the positive expression of bFGF, vascular endothelial growth factor (VEGF) and microvessel density (MVD) in transplanted tumor tissues.The tube formation of human umbilical vein endothelial cells (HUVECs) in vitro was used to study anti-bFGF mAb in inhibition ofangiogenesis.The inhibitionof anti-bFGF mAb in migration and invasion of cancer cells was examined by Matrigel invasion assay.The expressions of associated protein with apoptosis, metastasis,multidrug resistance, anti-bFGF mAb in suppressing cancer cells growth through the PI3K/AKT/mTOR pathway were examined by real-time fluorescence quantitative PCR and Western blotting.Preclinical pharmacokinetics of anti-bFGF mAb was measured in mice.Data of anti-bFGF mAb plasma concentration were analyzed using 3P97 software.Results: Anti-bFGF mAb significantly could inhibit the proliferation and induce apoptosis of melanoma, lung cancer and breast cancer cells, and show obvous inhibitory effects on the migration of cancer cells and the tube formation of HUVECs in vitro.Firstly, treatment of transplanted melanoma and lung cancer with anti-bFGF mAb in vivo resulted in significant reduction in tumor size and prolonged survival time of mice.Moreover, TUNEL assay and CD31 staining confirned the increase of apoptosis and decrease of intratumoral microvessel density in tumor sections from mice treated with anti-bFGF mAb.Secondly, there was a significant reduction in proliferation and significant increase in apoptosis in cancer cells treated with anti-bFGF mAb and chemotherapy drug.Lung cancer metastatic nodules and MVD in the combination group were significantly lower than those of single treatment groups.The expression of caspase-3, caspase-9, PARP, and BAX in combination group was higher than those from either agent alone.Anti-bFGF mAb suppressed the PI3K/AKT/mTOR pathway.Thirdly, the inhibitory rate of tumor growth in the combined of anti-bFGF mAb treatment group and radiotherapy group was significantly higher than radiotherapy group.The radiotherapy sensitization enhancement ratio of the combined treatment group was 2.37 times that in the radiotherapy group.The apoptosis rate of transplanted tumor cells was significantly increased by anti-bFGF mAb.bFGF, VEGF expression and MVD were significantly decreased by anti-bFGF mAb.Fourthly, the growth inhibition rates of breast cancer drug-sensitive MCF-7 cells and drug-resistant MCF-7/ADM cells after treatment with anti-bFGF mAb were (19.87±1.05)% and (27.34±2.79)% (P < 0.01).Anti-bFGF mAb could reverse doxorubicin, gemcitabine and oxaliplatin resistance of MCF-7/ADM cells, and the corresponding reversal index were 4.46, 4.25 and 2.18, respectively.Cell cycle of MCF-7/ADM cells after anti-bFGF mAb treatment was arrested at G0/G1 phase.The expression of P-glycoprotein was down-regulated.Intracellular Rho 123 fluorescence intensity was increased and the expression levels of MDR 1 and bFGF mRNAs were both decreased.Lastly, radiochemical purity level of 125I-bFGF-mAb was more than 98%, and trichloroacetic acid (TCA) precipitation of 125I-bFGFmAb was (90.8 ± 10.2) %.The main pharmacokinetic parameters were as follows: T1/2α (0.1~ 0.2 h), T1/2β (1.05~1.84h) and T1/2γ(81.6~90.3h).Heart,liver and lung were the major organs for deposition of125I-bFGF-mAb.Conclusion: Our data indicate that anti-bFGF mAbs display remarkable anti-tumor and anti-angiogenic effects in vitro and in vivo.Anti-bFGF mAb is potential therapeutic candidates for melanoma, lung cancer and breast cancer by effectively suppressing the tumor growth through inhibition of angiogenesis, proliferation and induction of apoptosis in the tumor.Anti-bFGF mAb combined with radiotherapy have synergistic inhibitory effect on the growth of transplanted melanoma tumor,and increase the radio-sensitivity of tumor cells by reducing the expressions of bFGF and VEGF, decrease angiogenesis, and promote apoptosis.Anti-bFGF mAb could have synergistic inhibitory effects on transplanted lung cancer, enhance chemotherapeutic agent-induced cytotoxicity and apoptosis by increasing the level of cleaved caspase-3, caspase-9 and PARP, decreasing the PI3K/AKT/mTOR pathway.Anti-bFGF mAb could inhibit the proliferation of breast cancer MDR cells,whichrelated to down-regulation of the expression of MDR-1 gene, inhibition of the function of P-glycoprotein, increasing intracellular concentration of chemotherapeutic drugs.The plasma concentration-time course of anti-bFGF mAb could consistent withthree-compartment model and specificity of tissue distribution.Further preclinical and systematical investigation on anti-bFGF mAb may help to increase efficacy and safety of molecular target therapy in melanoma, lung cancer and breast cancer.