ABSTRACT
【Objective】 To investigate the effect of polymerized human cord hemoglobin (PolyCHb) on the chemosensitivity of human breast cancer MCF-7 cell subcutaneous xenografts in nude mice and its mechanism. 【Methods】 The MCF-7 cells in exponential growth phase were collected and made into suspension cells at a density of 5×107 cells/mL.Subsequently, the cells were inoculated subcutaneously in the right limb of 18 BALB/c-nu nude mice with 0.2 mL cells per mouse to establish subcutaneous xenograft.When the tumor volume reached about 100 mm3, they were randomly divided into chemotherapy group: doxorubicin 5 mg·kg-1, once/week; chemotherapy + PolyCHb group: in addition to doxorubicin (chemotherapy group), PolyCHb 600 mg·kg-1, 3 times/week; the control group: normal saline 90 mg·kg-1, once/week; all were injected through tail vein continuously for 4 weeks.From the day of injection (d 0), the tumor volume of each group of nude mice was measured every 3 days, and the tumor growth curves were drawn accordingly.After 38 days, the tumor growth observation was completed.The tumor was removed and weighed to calculate the tumor inhibition rate.HE staining, immunohistochemistry and TUNEL method were used to observe the pathological changes of tumor tissue, detect the expression of HIF-1α, and detect tumor cell apoptosis respectively.The content of reactive oxygen species (ROS) of each group was determined by fluorescence staining. 【Results】 The tumor volume (mm3) of chemotherapy + PolyCHb group, chemotherapy group and the control group at day 38 were 196.35±103.45 vs 316.29±62.88 vs 519.42±177.33 (P<0.05), and the tumor inhibition rate (%) of chemotherapy + PolyCHb treatment group and chemotherapy group was 62.20 vs 39.11, respectively.HE staining and TUNEL detection showed that cell necrosis and apoptosis in the growth area of tumor tissue increased in chemotherapy + PolyCHb group.Immunohistochemistry and fluorescence staining showed that HIF-1α expression in chemotherapy + PolyCHb group decreased and reactive oxygen species (ROS) content increased. 【Conclusion】 PolyCHb increases the chemosensitivity of subcutaneous xenograft in nude mice with breast cancer, and its mechanism may be related to the increase of ROS in tumor tissue and the promotion of tumor cell apoptosis.
ABSTRACT
Objective To establish a mouse model by transplanting subcutaneously human pancreatic cancer tissue fragments.Methods Surgically resected pancreatic cancer tissue fragments from patients were transplanted into NOD/SCID mice subcutaneously,and then the growth of the tumor and transplanting it into the next generation were observed.The growth rate,HE staining and immunohistochemistry staining of Ki67 and VEGF were compared.Results We have obtained 13 cases ofpancreatic cancer tissues and 6 cases of biopsy specimens.In 5 cases transplantation was successful,in onemouse model passing to fourth generation,in 4 models to second generation.With the increase of generaions,tumor growth accelerated.HE staining showed later passage cells behavior in an identical manner as the primary cells.Immunohistochemistry staining showed that expressions of Ki67 and VEGF are increasing.Conclusions Through transplanting human pancreatic cancer tissue fragments directly,we have constructed mouse model of pancreatic cancer successfully.With the passage of subculture,the malignant degree and invasiveness may increase.
ABSTRACT
Objective:To investigate the inhibitory effect and its possible molecular mechanisms of MicroRNA-34a(miR-34a) on the human nasopharyngeal carcinoma CNE-2 cell line subcutaneous xenograft tumor in nude mice.Methods: The human nasopharyngeal carcinoma CNE-2 cell line was cultured in vitro.miR-34a and Scrambled miRNA recombinant plasmids were successfully established and stably transfected into CNE-2 cells.Fifteen six-week-old male nude mice were divided randomly into three groups:miR-34a group(5 mice) ,Scrambled miRNA group(5 mice) ,Blank control group(5 mice).Different CNE-2 cells were subcuta-neously injected on the back near right lower limb.Tumor volumes were examined every 7 days.Mice were executed on the 35 days,and the eventual average tumor volumes and weights were examined.Total RNA and protein were isolated from tumors,and the expression of miR-34a,CDK6,and Bcl-2 mRNA and protein were determined by qRT-PCR and western blot,respectively.Results: The relative expressions of miR-34a was significantly up-regulated in miR-34a transfected group compared to Scrambled miRNA transfected group (P (849.62±101.32) mm3 ,respectively,and the eventual average tumor weights in miR-34a group,Scrambled miRNA group and blank control group were(0.81±0.13)g,(1.47±0.21)g and(1.58±0.37)g,respectively.Both the eventual average tumor volumes and weights in miR-34a group were lower compared to the other two groups(P<0.05).qRT-PCR results revealed that the expression of miR-34a in miR-34a transfected group was significantly higher than in the other two groups,while the mRNA and protein expression of CDK6 and Bcl-2 were lower than the other two groups ( P<0.05 ) .Conclusion: miR-34a may inhibit the growth of human nasopharyngeal carcinoma CNE-2 cell line subcutaneous xenograft tumor in nude mice by down-regulating CDK6 and Bcl-2.