AIM:To evaluate the safety and feasibility of using vascular endothelial growth factor (VEGF) in the establishment of Walker-256 transplanted liver cancer model .METHODS: SD rats ( n =45) were divided into 3 groups:via the caudal vein, the rats in normal saline (NS) group were injected with 0.9%sodium chloride (0.1 mL/d), the rats in 20 mg/L VEGF group were injected with 20 mg/L VEGF (0.1 mL/d), and the rats in 40 mg/L VEGF group were injected with 40 mg/L VEGF (0.1 mL/d).All the injection began 1 week before transplantation of liver cancer , and stopped on the day the cancer model was established .Prepared tumor tissue was transplanted into the subcapsular space of the liver.Three days, 1 week and 2 weeks after the transplantation, magnetic resonance imaging (MRI) was performed for analyzing the tumor growth and the characteristics .The overall survival of the rats was also recorded .RESULTS:Success-ful establishment of Walker-256 transplanted liver cancer model was achieved .Among 45 rats, 1 rat died 1 d after implan-ting the tumor both in NS group and 20 mg/L VEGF group, while 3 rats died in 40 mg/L VEGF group 1 week after building the model, mainly because of the progression of tumors .Three days after modeling,the numbers of the rats in which the tumor was positively detected by MRI in 3 groups were 0, 7 and 10, respectively;1 week after modeling, those were 3, 13 and 13, respectively;2 weeks after modeling,those were 12, 13 and 10, respectively.Between NS group and 20 mg/L VEGF group, the statistical significance existed in the number of the rats in which the tumor was positively detected by MRI after 3 d of implanting, so did the NS group and 40 mg/L VEGF group.No statistical significance in the overall survival time between NS group and 20 mg/L VEGF group (P>0.05) was observed, but the significance existed between 40 mg/L VEGF group and NS group (P<0.01).CfONCLUSION:The application of VEGF at dose of 20 mg/L and 0.1 mL/d shortens the time to establish the transplanted liver cancer model without influence on the overall survival , which is a safe, feasible and efficient way, and is more suitable for anti-VEGF drug investigation.

AIM:To establish an effective and rapid method to develop transplanted subcutaneous pancreatic carcinoma by inducing PANC-1 cells into nude mice, and then use this mouse model to evaluate the tumor-homing and gene-silencing effects of siRNA-loading nanoparticles in vivo.METHODS:Different numbers of PANC-1 cells in 100 μL or 300 μL PBS were inoculated subcutaneously into the right flank of BALB /c (nu/nu) mice.When the tumor volume reached 100 mm 3 , siRNACY 5.5 nanoparticles were injected through the mouse tail vein to perform in vivo imaging assay.Be-sides, the mice were randomly divided into 3 treatment groups treated with PBS, scrambled control RNA nanoparticles and siKras nanoparticles, respectively.The protein expression of Kras was detected by Western blotting and immunohistochemi-cal staining.RESULTS:After inoculated with 1 ×10 7 PANC-1 cells in 300 μL PBS, all mice developed tumors within 2 weeks.The in vivo results showed that siRNA-loading nanoparticles accumulated in the tumor tissues and exerted gene si-lencing effect.CONCLUSION:In the present study, an effective and rapid method was established for PANC-1 cells to induce transplanted subcutaneous pancreatic carcinoma in nude mice within 2 weeks, which is suitable for in vivo imaging and treatment evaluations as a reproducible and reliable way for the further experiments .

AIM:To observe the effect of captopril on the genesis and development of gastric cancer , and to explore its clinical treatment feasibility for gastric cancer .METHODS:The human gastric cancer cell line AGS was used to establish a tumor model in nude mice , and the model mice were randomly divided into 3 groups: positive control ( 5-fluorouracil) group, normal control (saline) group and experimental (captopril) group.After intraperitoneal injection or intragastric administration of the drugs , the tumor growth curve was determined , and the tumor tissues were also sampled to detect the expression of Ki-67, STAT3, Bax and Bcl-2 by real-time quantitative PCR and immunohistochemistry .The apop-tosis was detected by TUNEL +DAPI staining .RESULTS: The tumor growth curve showed that the tumor model in the nude mice was successfully established .The tumor volumes among groups showed significantly different after 14 d growth. The increase in the tumor volume in normal control group was significantly faster than that in the other two groups , and that in positive control group was the slowest .The expression of Bax in captopril group increased , and the expression of STAT3, Ki-67 and Bcl-2 was reduced as compared with normal control group and positive control group .Compared with normal con-trol group, the apoptotic rate increased significantly , and the protein expression of p-STAT3 and STAT3 decreased obviously in positive control group and captopril group .CONCLUSION:With better feasibility , angiotensin-converting enzyme in-hibitor captopril has a significant effect on treating gastric cancer in the AGS nude mouse model by regulating the expression of STAT3, Bax, Bcl-2 and Ki-67 to accelerate the apoptosis of cancer cells , thus inhibiting tumor growth .

AIM:To study the effect and the molecular mechanism of CDX 2 over-expression on the prolifera-tion, growth and cell cycle of human gastric cancer cell line SGC-7901.METHODS:The SGC-7901 cells in LV-CDX2-GFP group were transfected with the recombinant lentivirus vector LV-CDX2-GFP, the cells in LV-GFP group were trans-fected with the negative control lentiviral vector for the negative control , and the cells in blank control group were without any treatment.The cell proliferation was detected by CCK-8 assay.The cell cycle distribution was analyzed by flow cytome-try.The expression of CDX2, Bax, Bcl-2, cyclin D1 and survivin was determined by semi-quantitative RT-PCR and Wes-tern blotting .RESULTS:Compared with LV-GFP group and blank control group , the proliferation activity of the SGC-7901 cells was significantly lower (P<0.05), the G0/G1 phase proportion increased (P<0.05), the mRNA and protein levels of Bcl-2, cyclin D1 and survivin were reduced (P<0.05), and the mRNA and protein levels of Bax were up-regula-ted (P<0.05) in LV-CDX2-GFP group.No statistically significant difference of the above indexes was observed (P>0.05) between LV-GFP group and blank control group .CONCLUSION:Over-expression of CDX2 mediated by lentivirus inhibits the proliferation and growth of human gastric cancer SGC-7901 cells and arrestes the cell cycle at G 0/G1 phase, which may be related to down-regulation of Bcl-2, cyclin D1 and survivin and up-regulation of Bax .

AIM:To explore the effects of miR-21 on biological behavior of colon cancer cells and their sensi-tivity to epidermal growth factor receptor monoclonal antibody cetuximab .METHODS:Lentiviral vectors were constructed to generate up-and down-regulations of miR-21 lentiviruses (LV-miR-21 and LV-anti-miR-21, respectively), and the cor-responding negative control viruses (LV-miR-21 NC and LV-anti-miR-21 NC, respectively) were also constructed.The vi-ruses were used to infect human colon cancer RKO cells .The changes of the miR-21 expression level , the cell prolifera-tion, the colony-forming ability, the cell apoptosis and the sensitivity of the cells to cetuximab were detected by real -time PCR, MTT assay, soft agar colony assay , flow cytometry and CCK-8 assay.RESULTS: The lentivirus titers of LV-miR-21, LV-miR-2 NC, LV-anti-miR-21 and LV-anti-miR-21 NC were 3.0 ×1012 TU/L, 6.0 ×1011 TU/L, 2.0 ×1012 TU/L and 8.0 ×1011 TU/L, respectively.The infection efficiency was over 80% by the observation of green fluorescence .The miR-21 expression level , the cell proliferation , and the colony-forming ability in LV-miR-21 group were significantly higher than those in LV-anti-miR-21 group.The early apoptotic rate and the inhibitory rate of cetuximab for the cells in LV-anti-miR-21 group were higher than those in LV-miR-21 group.CONCLUSION: miR-21 promotes the proliferation of colon cancer cells.Down-regulation of miR-21 enhances the sensitivity of the colon cancer cells to the targeted therapy drug cetuximab.

AIM:To explore the effect of Vaccinium vitis procyanidin on the growth of glioma cells .METH-ODS:Glioma C6 cells were cultured and divided into control and 10, 20 and 40μg/L Vaccinium vitis procyanidin groups . The influence of Vaccinium vitis procyanidin on the growth of C 6 cells was measured by MTT assay and the observation un-der inverted microscope .The apoptotic rate was detected by Annexin V/PI staining .The protein expression of Bcl-2 and Bax was determined by immunocytochemistry .The protein levels of Bcl-2, Bax and caspase-3 were also examined by West-ern blotting .RESULTS:The growth of C6 glioma cells was inhibited by Vaccinium vitis procyanidin at concentrations of 10, 20 and 40 μg/L.The growth was significantly inhibited in 40 μg/L Vaccinium vitis procyanidin group at 24 h and 48 h, and in 20 and 40 μg/L Vaccinium vitis procyanidin groups at 72 h (P<0.01).The density of the cells was decreased when the concentration of Vaccinium vitis procyanidin increased .The apoptotic rate was increased when the concentration of Vaccinium vitis procyanidin increased either .The expression of Bcl-2 was decreased and Bax was increased after 10, 20 and 40 μg/L Vaccinium vitis procyanidin treatments .The ratio of Bax/Bcl-2 was increased when the dose of Vaccinium vitis pro-cyanidin increased (P<0.05 or P<0.01).The expression of Bcl-2 was decreased (P<0.01), and Bax and caspase-3 were increased after 10, 20 and 40 μg/L Vaccinium vitis procyanidin treatments .The ratio of Bax/Bcl-2 was increased when the dose of Vaccinium vitis procyanidin increased (P<0.01).CONCLUSION:Vaccinium vitis procyanidin inhibits the growth of glioma cells by down-regulating Bcl-2 protein and up-regulating Bax protein to activate caspase-3, thus indu-cing apoptosis .

AIM:To observe the expression of nuclear factor-kappa B ( NF-κB) , N-methyl-D-aspartic acid re-ceptor 2B (NR2B) and inducible nitric oxide synthase (iNOS) in the spinal cord in a rat model of chronic constriction in-jury (CCI) of the sciatic nerve.METHODS:Fifty-six adult male Sprague-Dawley rats weighing 180~220 g were random-ly divided into sham group (n=8) and CCI group (n=48).The mechanical withdrawal threshold (MWT) and paw with-drawal latency (PWL) of the hind paws were measured 1 d before CCI and 1 d, 4 d, 7 d, 14 d and 21 d after surgery.The L4~L6 segment of the spinal cord was taken for determining the expression of NF-κB, NR2B and iNOS by RT-PCR and Western blotting.RESULTS:At 1 d, 4 d, 7 d, 14 d and 21 d after surgery, the MWT and PWL in CCI group were obviously lower than those in sham group .The expression of NF-κB, NR2B and iNOS at mRNA and protein levels in-creased significantly.Positive correlations were found between the mRNA expression of NF-κB and iNOS (r=0.842, P<0.05), and between the mRNA expression of NR2B and iNOS (r=0.833, P<0.05).CONCLUSION:The generation and maintenance of hyperalgesia in sciatic nerve injury rats may attribute to the activation of NF -κB and NR2B and concom-itant increase in iNOS .

AIM: To verify the neuroprotective effect and optimize the therapeutic dose and time window of picroside Ⅱon cerebral ischemic injury in rats .METHODS:The forebrain ischemia model was established by the method of bilateral common carotid artery occlusion ( BCCAO ) .The successful model rats were randomly divided into 16 groups according to orthogonal design and treated by intraperitoneal injection of picroside Ⅱat different ischemic time poinis and different doses .The changes of the nerve fiber myelin were observed by fast green staining .The immunohistochemical assay and Western blotting were used to quantitatively and qualitatively determine the expression of myelin basic protein (MBP). The mRNA level of MBP in the brain tissues was tested by reverse transcription polymerase chain reaction (RT-PCR).RE-SULTS:Picroside Ⅱ increased the expression of MBP and decreased demyelination after cerebral ischemic injury .The best therapeutic time window and dose were:(1) ischemia for 2.0 h with picrosideⅡat dose of 10 mg/kg according to the results of fast green staining;(2) ischemia for 2.0 h with the dose of 10 mg/kg according to the results of immunohisto-chemical assay;(3) ischemia for 2.0 h with the dose of 10 mg/kg according to the analysis of Western blotting;(4) is-chemia for 1.5 h with the dose of 20 mg/kg according to the detection of RT-PCR.CONCLUSION:Given the principle of the lowest therapeutic dose with the longest time window , the optimized therapeutic dose and time window for rat cerebral ischemic injury is intraperitoneal injection of picroside Ⅱat the doses of 10~20 mg/kg and the time window of ischemia for 1.5~2.0 h.

AIM: To study the effect of G-protein-coupled receptor kinase 5 (GRK5) on the activation of astrocytesin the brain cortex of newborn Wistar rats .METHODS: GRK5 gene was silenced in the model of rat brain cortexastrocytes in vitro for 24 h.N-acetylcysteine (NAC), which is a known inhibitor of NF-κB, was added into the culture mediumaccording to gene silencing for 24 h.The expression levels of GFAP and caspase-3 were detected by the method of immunofluorescence,and the mRNA levels of NF-κB, TNF-α, IL-1βand iNOS were determined by real-time PCR.Moreover,the activity of SOD and concentrations of TNF -αand NO were measured.RESULTS: GRK5 gene silencing increasedthe expression of NF-κB at mRNA and protein levels obviously (P <0.01), and the mRNA levels of IL-1βand iNOS increasedsynchronously (P <0.01).Furthermore, caspase-3-positive cells in GRK5 siRNA group were increased comparedwith control siRNA group (P <0.01).Treatment with NAC obviously reduced the activity of NF -κB and weakened theeffects induced by GRK5 siRNA (P <0.05).CONCLUSION: GRK5 siRNA increases NF-κB activity and induces the activationof astrocytes.

AIM:To investigate the effects of 17β-estradiol on the expression of macrophage migration inhibi-tory factor ( MIF) in cultured endometrial stromal cells from endometriosis .METHODS:Immunohistochemistry was used to identify the endometrial stromal cells .The expression of MIF at mRNA and protein levels was assessed by RT-PCR and Western blotting .RESULTS:Elevated expression of MIF at mRNA and protein levels was observed in the cultured endom-etrial stromal cells treated with 17β-estradiol.In endometrial stromal cells from the women with endometriosis , the level of MIF up-regulation by 17β-estradiol was significantly higher than that in the cells from the women without endometriosis . CONCLUSION:Endometrial stromal cells from endometriosis are more sensitive to 17β-estradiol, which up-regulates the expression of MIF and contribute to the pathogenesis and progression of endometriosis .