目的：研究小鼠头颈鳞癌细胞株SCCⅦ体外放射敏感性，并探讨其与细胞周期阻滞的可能关系。方法：利用细胞克隆形成试验及MTT法检测SCCⅦ细胞受X射线照射后细胞存活能力及细胞生长趋势的变化，通过流式细胞学检测X射线照射后细胞周期分布的变化。结果：相同剂量照射后的SCCⅦ细胞存活分数高于Hela细胞（Plt;0.05）；4 Gy照射后的SCCⅦ细胞在96 h内细胞生长速度仍高于Hela细胞（Plt;0.05）；4 Gy照射后SCCⅦ细胞G1期和G2期细胞比例明显升高（Plt;0.05）。结论：SCCⅦ细胞对放射线不敏感性，放射线导致的细胞周期阻滞是SCCⅦ细胞放射抵抗的可能原因之一
ObjectiveTo investigate the growth characteristics of pancreatic cancer cells in the twodimensional culture system (monolayer) and threedimensional culture system (type Ⅰ collagen and extracellular matrix gel). MethodsThree pancreatic cancer cell lines (SW1990, PCT, and ASPC1) were cultured in monolayer, type Ⅰ collagen, and extracellular matrix gel, respectively. The growth patterns were observed, growth curves were detected by CCK8 test, and the cell cycle distributions were analyzed by propidium iodide staining. Results In the twodimensional culture system, cells grew in monolayer. In the type Ⅰ collagen and the ECM gel threedimensional culture system, cells formed multicellular spheroids (MCS), of which the growth rates were slower than those of the cells in monolayer. The proportions of S phase of SW1990, PCT, and ASPC1 cells in twodimensional culture system were significantly more than those in the type Ⅰ collagen on 4 d and 8 d 〔(29.6±3.0)% vs. (18.2±5.1)%, (33.6±2.1)% vs. (14.5±3.2)%, (33.1±1.8)% vs. (24.7±2.6)%; Plt;0.05〕, while the difference of proportion of three cell lines in G2/M phase was not different between twodimensional culture system and type Ⅰ collagen (Pgt;0.05). The proportions of G0/G1 phase of SW1990 and PCT cells cultured in the type Ⅰ collagen on 4 d and 8 d and ASPC1 cells cultured in the type Ⅰ collagen on 4 d were significant more than those cultured in twodimensional culture system (Plt;0.05). The proportions of S phase of ASPC1 cells and SW1990 cells cultured in the type Ⅰ collagen on 4 d were significant more than those cultured in the type Ⅰ collagen on 8 d (Plt;0.05). ConclusionsThe characteristics of pancreatic cancer cells in twodimensional and threedimensional culture systems are different. MCS culture system can better mimic the in vivo growth environment of cells in tumors.
【Abstract】ObjectiveTo investigate the inhibitory effects of somatostatin analogue (SSTA) on the colonic carcinoma cell growth in vitro and in vivo and its possible mechanism. MethodsThe somatostatin receptor type Ⅱ (SSTR2) mRNA of colonic carcinoma cell line HCT116 was detected by using RTPCR and hybridization in situ. The effects of octreotide (Oct) or NC-8-12 (specific agonist of SSTR2 ) on the proliferation of HCT116 was measured with MTT after HCT116 stimulated by insulin or epidermal growth factor (EGF) and incubated with Oct or NC-8-12 simultaneously for 24 hours. The expression of cyclin D1 was detected with flow cytometry. The HCT116 were implanted in nude mice subcutaneously and treated with Oct or NC-8-12. The tumor volume and tumor weight were measured according to schedule. Results①SSTR2 mRNA was detected in HCT116 and the tumor implanted in nude mice; ②Insulin and EGF increased the proliferation of HCT116 significantly, and this proliferation could be inhibited by Oct and NC-8-12 partially; ③Insulin increased the Cyclin D1 expression of HCT116, its level decreased slightly when treated with Oct or NC-8-12 but not significantly (Pgt;0.05); ④The weight and volume of implanted tumor in nude mice treated with Oct or NC-8-12 showed no significant difference compared with the control group (Pgt;0.05). ConclusionBoth Oct and NC-8-12 could inhibit the proliferation of colonic carcinoma cell line HCT116 in vitro, which indicated that SSTR2 may mediated the inhibition. Oct and NC-8-12 have no effect on the growth of implanted HCT116 in nude mice in this experiment.
ObjectiveTo study the effects of recombinant human growth hormone (rhGH) on proliferation of human rectal cancer cell in vitro. MethodsThe experiment was divided into control group,rhGH group,Oxaliplatin (LOHP) group and rhGH+LOHP group. The double proliferation time of cells,cell inhibition rate,cell cycle, proliferation index (PI) and DNA inhibition rate of human rectal cancer line,HR8348,were studied by cell culture, MTT assay and flow cytometry on different concentration of rhGH. ResultsIn vitro the markedly accelerated effects of rhGH on multiplication of HR8348 cell line were not found: there was no statistical significance as compared rhGH group with control group or compared rhGH+LOHP group and LOHP group （Pgt;0.05）. The double proliferation time of cells was markedly lengthened, cell inhibition rate and the cells arrested in G0-G1 phase were obviously increased, meanwhile, the cells in S phase （P＜0.05） and G2-M phase and PI were markedly decreased and DNA inhibition rate was obviously risen as compared rhGH+LOHP group with control group or rhGH+LOHP group and rhGH group （P＜0.01）.ConclusionIn vitro rhGH does not accelerate the multiplication of human rectal cancer cells.
Objective To investigate the effect of cholecystectomy on the induction of large intestine cancer and its mechanism. Methods After cholecystectomy, the large intestine neoplasm in mice was induced with dimethylhydrazine(DMH).The histogenesis and growth pattern of large intestine cancer were observed.The Sphase fraction (SPF) of epithelium cells in large intestine mucosa was determined using flow cytometry. Before and after operation, the feces of mice were collected to determine the cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA) and lithocholic acid (LCA) concentration by highperformance liquid chromatography. Results The average number of large intestine neoplasms per mouse,percentage of large intestine adenomas in examined mice and SPF of experimental group were significantly higher than those of control group (P＜0.05). The fecal LCA concentration in postcholecystectomy was significantly higher than that in precholecystectomy and in sham operation group (P=0.00). Conclusion The large intestine neoplasm of mice induced by DMH is increased and the proliferation of epithelium cell in large intestine mucosa is increased after cholecystectomy. This suggests that cholecystectomy has promoting effect on induction of large intestine neoplasm in mice. The gut may deal with the increased secondary bile acid(LCA) concentration postcholecystectomy.
ObjectiveTo construct DPC4 gene recombinant expression vector and to study the inhibitory effect of DPC4 on the growth of human pancreatic adenocarcinoma cell line (PC3) cells.MethodsDPC4 cDNA was amplified from K562 cell line using RTPCR, and was cloned into the pcDNA3.1 vector to construct a recombinant expression vector plasmid pcDNA3.1DPC4. The recombinant expression plasmid was transferred into PC3 cells by liposome method. After G418 selection, cell cycle and apoptosis were assessed by flow cytometry, then the cell growth rate was estimated by cell count. The cells being not transferred plasmid and transferred pcDNA3.1 plasmid were used as controls.ResultsThe DPC4 gene recombinant expression vector was constructed. Wildtype DPC4 gene attributed to the increase of G1 phase cells and the decrease of S phase cells in PC3 cells,and could inhibit the growth of PC3 cells, the cell growth rates was reduced to 34.3%-41.1% of that of the controls, but cell apoptosis was not observed on all groups. ConclusionWildtype DPC4 gene could inhibit the proliferation of human pancreatic adenocarcinoma cells and could become one of the target genes of pancreas adenocarcinoma gene therapy
Objective To study the expression and its significance of cyclin D1,cyclin E and p27 protein in gastric carcinoma. Methods The expression of cyclin D1,cyclin E and p27 protein in 60 cases of gastric carcinoma were detected by immunostaining method. Results The positive rates of cyclin D1,cyclin E and p27 protein expression in gastric carcinoma were 41.7%（25/60）,38.3%（23/60）and 36.7%（22/60）,respectively.The expression of cyclin D1 was significantly correlated with Lauren type of tumor,the expression of cyclin E was significantly correlated with tumor differentiation,infiltration and stage,while the expression of p27 protein was significantly correlated with tumor infiltration,lymph nodes metastasis and stage. Further more, the expression of cyclin E was inversely correlated with the expression of p27. Conclusion Detection of cyclin D1,cyclin E and p27 expression in gastric carcinoma may be helpful in determining tumor progression.
For research the relationship between the expression of vascular endothelial growth factor (VEGF) and the cell proliferation. The expression of VEGF was evaluated while the cell cycle of hepatoma cell line Hep G2, which was synchronized at G0 phase with serum deprivation, and reinitiated with TPA and blocked with antisense oligonucleotides of c-jun. Results: Hep G2 cell did not express VEGF at G0 phase. TPA could induce the expression of VEGF as well as initiation of cell cycle. The antisense oligonucleotides of c-jun could prohibit the expression of VEGF and arrest the cell cycle at G0 phase. Conclusion: The fact that the expression of VEGF accompanies the initiation of cell cycle suggests that they be regulated by the same singnal pathway, the expression of VEGF may be a marker indicating the proliferation of hepatoma cells.
Objective To investigate the effects of extracellular signal regulated kinase ( ERK)signaling pathway on cell cycle of airway smooth muscle cells( ASMCs) in asthmatic rats. Methods Thirty Wistar rats were randomly assigned to a control group and an asthma group( 15 rats in each group) . Asthma model was established by ovalbumim sensitization and challenge. ASMC were isolated and cultured in vitro. The ASMCs from the asthmatic rats were treated with ERK activator epidermal growth factor ( EGF)and inhibitor PD98059, respectively. The expressions of cyclin D1 and CDK2 in ASMCs were detected by immunocytochemical staining. The expressions of ERK1 /2 and p-ERK1 /2 protein were observed by western blotting for measurement of ERK activation rate. Results Compared with the control group[ 54. 17 ±6. 11,61. 04 ±4. 09, ( 49. 91 ±3. 26) % , respectively] , the expressions of cyclin D1 protein and CDK2 protein,and the rate of ERK activation of ASMCs from the asthmatic rats significantly increased[ 76. 15 ±4. 88,92. 30 ±7. 95, ( 82. 37 ±5. 78) % , respectively] ( P lt; 0. 05) . Furthermore, compared with those before treatment, the expression of cyclin D1 and CDK2, and the rate of ERK activation of ASMCs significantly decreased after treatment with PD98059 [ 58. 78 ±4. 60, 69. 15 ±5. 83, ( 54. 01 ±4. 12) % , respectively]( P lt; 0. 05) , and significantly increased after treatment with EGF[ 119. 28 ±8. 14, 134. 77 ±9. 26, ( 91. 57 ±5. 32) %, respectively] ( P lt;0. 05) . Conclusion ERK1/ 2 participates in proliferation regulation of ASMCs in asthma by enhancing the expressions of cyclin D1 and CDK2, which promotes quiescent cells into S phase.
Objective Metal wear products cause the aseptic loosening of joint prosthesis. To investigate the effect of metal ions Co2+ and Cr3+ on the osteoblast apoptosis, cell cycle distribution, and secretion of alkal ine phosphatase (ALP), and to search a method to prevent and treat aseptic loosening. Methods The mouse calvarial osteoblasts (MC3T3-E1) were cultured in vitro to 3-5 generations (5 × 105 cells/ mL) and divided into 2 groups: the experimental group and the controlgroup. The osteoblasts were cultured in α-MEM medium containing 10%FBS (the control group), and the mixed solution ofCoCl2 and CrCl3 was added after the osteoblasts cultured in α-MEM medium containing 10%FBS attached completely (the experimental group). At 12, 24, and 48 hours after culture, the osteoblast apoptosis and the cell cycle distribution were assessed by flow cytometry; and ELISA method was appl ied to detect ALP content in serum supernatant. Results At 12, 24, and 48 hours after culture, the apoptosis rates in the experimental group (13.90% ± 0.52%, 14.80% ± 0.41%, and 13.40% ± 0.26%) were significantly higher than those in the control group (8.56% ± 0.31%, 8.19% ± 0.24%, and 2.15% ± 0.11%), (P lt; 0.05); G2M (dividing phase) distribution ratio significantly decreased and G0G1 (dormancy stage) distribution ratio significantly increased when compared with those in the control group (P lt; 0.05); and the absorbency (A) values of ALP were 0.955 ± 0.052, 0.624 ± 0.041, and 0.498 ± 0.026 in the exprimental group, and were 1.664 ± 0.041, 1.986 ± 0.024, and 2.192 ± 0.041 in the control group, showing significant differences between 2 groups (P lt; 0.05). Conclusion Metal ions Co2+ and Cr3+ have a marked effect on osteoblasts cell cycle distribution, which can make most of the cells to be in dormancy stage (G0G1), up-regulate the apoptosis rate and inhibit the releasion of ALP from osteoblasts.