The Impact Of Recombinant Human Growth Hormone On Human Gastric Cancer Xenografts In Nude Mice And Bone Marrow

Objective To study effects recombinant human growth hormone on growth of human gastric cancer cell and part mechanism in vivo and on hematopoietic function of bone marrow of nude mice.Methods In our study,human gastric cancer xenograft model of node mice was successfully founded after human gastric cancer cell line(MKN45)was cultured. Experiment was divided into control group,cisplatin(DDP)group(celiac injection, DDP),recombinant human growth hormone(rhGH)group(subcutanenous injection rhGH)and DDP+rhGH group(celiac injection,DDP and subcutanenous injection, rhGH)and 6 nude mouse in each group.and drugs were used for 6 days.We investigated the effects of rhGH on below index of nude mouse:volume of tumor, inhibitory rate of tumor,weight of nude mouse,coefficient of organ,cell cycle,cell proliferation index(PI),DNA inhibitory rate,apoptosis rate,caryon proliferation antigen(PCNA),apoptosis index(AI)of xenograft,growth hormone(GH),insulin-like growth factor-â… (IGF-â… ),insulin-like growth factor binding protein(IGFBP)-3, vascular endothelial growth factor(VEGF)of blood serum,IGF-â… mRNA, insulin-like growth factor-â… ecoptor(IGF-â… R)mRNA,IGFBP-3 mRNA and VEGFmRNA of xenograft count of myeloid cells and myeloid pathomorphology by flow cytometry,immuno- histochemistry,Terminal Deoxynucleotidyl Transferase -mediated deoxyuridine triphosphate biotin nick end labeling(TUNEL),Reverse transcriptase-polymerase chain reaction(RT-PCR),Enzyme linked immunosorbent assay(ELISA),bone marrow slides and myeloid pathology on the next day and the third day of completing use of drugs later respectively.Resultsâ‘ Volume of xenograft,Tumor inhibitory rate,Weight of nude mouse and Organ coefficient:On the next day and the third day of completing use of drugs later, xenograft grew obviously slowly,tumor inhibitory rate obviously rose,weight of nude mouse obviously decreased and organ coefficient of spleen obviously also dropped in DDP group and DDP+rhGH group compared with control group and rhGH group(p＜0.05);but volume of xenograft,tumor inhibitory rate,weight of nude mouse and organ coefficient were not remarkably different between DDP group and DDP+rhGH group or between control group and rhGH group(p＞0.05).â‘¡Cycle of cell:Cells of gastric cancer xenograft in S phase distictly diminished in DDP group and DDP+rhGH group compared with control group and rhGH group(p＜0.05)on the next day and the third day of completing use of drugs later;but there was not statistically significant in G₀-G₁ phase and G2-M phase among all groups and it was not statistically significant between DDP group and DDP+rhGH group or between control group and rhGH group yet(p＞0.05).â‘¢Proliferation index(PI)and DNA inhibitory rate:On the next day and the third day of completing use of drugs later, there was not statistically significant in PI among all groups(p＞0.05),but DNA inhibitory rate rose in DDP group and DDP+rhGH group compared with control group and rhGH group.â‘£Caryon proliferation antigen(PCNA)and Apoptosis Index (AI):On the next day of completing use of drugs later,PCNA obviously dropped in DDP group compared with control group and rhGH group and AI obviously rose in DDP group and DDP+rhGH group compared with control group and rhGH group(p＜0.05);meanwhile,on the third day of completing use of drugs later,PCNA obviously dropped and AI obviously rose in DDP group and DDP+rhGH group compared with control group and rhGH group(p＜0.05).But PCNA and AI were not statistical difference between DDP group and DDP+rhGH group or between control group and rhGH group(p＞0.05).⑤Examination of RT-PCR:On the next day and the third day of completing use of drugs later,express of IGF-â… mRNA and IGF-â… R mRNA did not obviously increase,but express of IGFBP-3 mRNA and VEGF mRNA obviously increased in rhGH group compared with control group,meanwhile,express of IGFBP-3 mRNA also obviously increased in DDP group and DDP+rhGH group compared with control group and rhGH group,and it more expressed in DDP+rhGH group.On the third day of completing use of drugs later,express of VEGF mRNA obviously dropped in DDP+rhGH group.â‘¥Examination of blood serum:On the next day of completing use of drugs later,GH,IGF-â… ,IGFBP-3 of blood serum of nude mouse obviously rose in rhGH group and DDP+rhGH group compared with control group and DDP group,but VEGF obviously dropped in DDP group compared with control group and rhGH group(p＜0.05).On the third day of completing use of drugs later,VEGF obviously dropped in DDP group and DDP+rhGH group compared with control group and rhGH group(p＜0.05)and there was no statistic difference in GH,IGF-â… and IGFBP-3 among all groups.⑦Count of bone marrow slides:On the next day and the third day of completing use of drugs later,granulocytic series of bone marrow obviously dropped and monocytic series obviously rose in DDP group compared with other three groups and erythrocytic series also dropped in DDP group Compared with control group and rhGH group(p＜0.05),but there was no statistic difference in lymphocytic series among all groups and it was so in all cell series between rhGH group and control group or between DDP+rhGH group with DDP group.⑧pathomorphology of bone marrow:On the next day of completing use of drugs later,all cells,multinucleated giant cell,granulocyt and near mature granulocyt decreased and cellular nucleus of most cells concentrated in DDP group.On the third day of completing use of drugs later,all cells decrease relatively and constitution of tissue and ratio of all cell series were normal on the whole and part cellular nucleus of most cells concentrated.But cells actively proliferated and constitution of tissue and ratio of all cell series were normal on the whole in other three groups on the next day and the third day of completing use of drugs later.Conclusion Our results indicated rhGH in short time use did not improve proliferation of human gastric cancer cell lines.Its mechanism was possibly that rhGH transiently rose GH,IGF-â… and IGFBP-3 of blood serum and did not increase express of IGF-â… mRNA and IGF-â… R mRNA but increased IGFBP-3 mRNA in human grastic cancer cells,meanwhile,rhGH obviously dropped express of VEGF mRNA combining with chemotherapic drug.RhGH could protect granulocytic series and erythrocytic series of marrow and could improve constitution of tissue of marrow in chemotherapied rats with bearing gastric cancer.