ObjectiveTo explore the influence of different radiation doses of 125Ⅰseed on human poorly differentiated gastric cancer cells (BGC823). MethodsSixty four male nude mice of BLAB nu/nu inoculated with human poorly differentiated gastric cancer cells (BGC823) were took as animal models. When tumors of nude mice grew to 0.7-1.2 cm, the nude mice were randomly divided into blank control group, low dose group, middle dose group, and high dose group (n=16). The tumors of nude mice in blank control group were implanted with blank seed, but tumors of nude mice in low dose group, middle dose group, and high dose group were implanted with 125Ⅰseed (the radiation doses of 3 groups were 1.48×10-7 Bq, 2.22×10-7 Bq, and 2.96×10-7 Bq respectively). Four nude mice of 4 groups were randomly collected to measure the tumor volume and weight before implantation, and on 7, 14, 21, and 28 days after implantation, but apoptosis rates and expression levels of cyclinE mRNA were measured on 14 days and 28 days after implantation, by using flow cytometer and semi quantitative RT-PCR method respectively. Results①Except for the blank control group, the tumor volume and weight decreased over time in low dose group, middle dose group, and high dose group. The tumor volume and weight in blank control group were higher than those of other 3 groups on 7, 14, 21, and 28 days after implantation (P < 0.05);in addition, on 28 days after implantation, tumor volume and weight in low dose group were lower than those of middle dose group and high dose group (P < 0.05).②On 14 days and 28 days after implantation, the apoptosis rates of blank control group were lower than those of other 3 groups (P < 0.05), but expression levels of cyclinE mRNA were all higher than those of other 3 groups (P < 0.05). In addition, on 28 days after implantation, apoptosis rate of low dose group was higher than both of middle dose group and high dose group (P < 0.05), but expression level of cyclinE mRNA was lower (P < 0.05). Compared with 14 days in the same group, except for the blank control group (P > 0.05), the apoptosis rates in other 3 groups on 28 days were higher (P < 0.05), with the lower expression levels of cyclinE mRNA (P < 0.05). Conclusions125Ⅰseed in organizational implantation can effectively inhibit the expression of cyclinE mRNA and the growth of human poorly differentiated gastric cancer tissue. Compared with doses of 2.22×10-7 Bq and 2.96×10-7 Bq of 125Ⅰ, low dose (1.48×10-7 Bq) contributes to the apoptosis of human poorly differentiated gastric cancer cells (BGC823).
【Abstract】 Objective To investigate the expression and significance of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors in pancreatic cancer. Methods Thirty-two samples of pancreatic cancer tissue were collected from year 2002 to 2004. All of them were verified by histopathology and there were 9 cases of well-differentiated, 12 of moderately differentiated, and 11 of poorly differentiated, in which 12 cases were in the stage of Ⅰor Ⅱand 20 in the stage of Ⅲ or Ⅳ according to the TNM staging method. Eighteen normal pancreatic tissues were used as control group. The expressions of TRAIL receptors (death receptor 4, death receptor 5, decoy receptor 4 and decoy receptor 5) mRNA were assayed by semi-quantitive reverse transcription polymerase chain reaction (RT-PCR) in the pancreatic cancer tissues and the normal pancreatic tissues. Results The expressions of death receptor 4 (DR4) and death receptor 5 (DR5) were detected in all the pancreatic cancer tissues and the normal pancreatic tissues and the levels of DR4 and DR5 were significantly higher than those of the normal pancreatic tissues (P＜0.01). Decoy receptor 1 (DcR1) and decoy receptor 2 (DcR2) were also expressed in normal pancreatic tissues, whereas DcR1 and DcR2 were only expressed in 18 and 20 pancreatic cancer tissues, respectively. However, there were no significant difference of the expression of DcR1 and DcR2 between the pancreatic cancer tissues and the normal pancreatic tissues （Pgt;0.05）. The expression level of DR5 in pancreatic cancer tissue was correlated with tumor differentiation and clinical stage, and the levels in stage Ⅲ and stage Ⅳwere significantly lower than those of stageⅠand stageⅡ(P＜0.05). The expressions of DR4, DcR1 and DcR2 were not correlated with tumor differentiation and clinical stage (Pgt;0.05). Conclusion ①The expression of TRAIL receptors in pancreatic cancer tissues is prevalent, but the types of receptors expressed in different tissues were also different. High expression of death receptors may play an important role in TRAIL recptors regulated pancreatic cancer apoptosis. ②The expression of DR5 is correlated with the differentiation degree of pancreatic cancer cell and clinical stage of tumor. The expressions of DR4, DcR1 and DcR2 should not be considered as related indexes of differentiation degree or clinical stage of pancreatic cancer.
ObjectiveTo investigate the effects of phenethyl isothiocyanate (PEITC) on apoptosis and proliferation of breast cancer SK-BR-3 cells. MethodsSK-BR-3 cells were treated with different concentrations (0, 10, 30, 50 μmol/L) of PEITC respectively. The proliferation capacity of SK-BR-3 cells was detected by MTT and BrdU staining methods. The cell apoptosis was detected by TUNEL and flow cytometry methods. The protein and mRNA expressions levels of indexes related apoptosis such as Bcl-2, Bax, and MCL-1 and indexes related endoplasmic reticulum stress (ERS) such as PERK, eIF2α, CHOP, IRE1α, ATF6α were detected by Western blot and quantitative real-time PCR (qRT-PCR), respectively. ResultsCompared with the control group (0 μmol/L PEITC treatment group), the results of MTT and BrdU staining methods showed that the proliferations of SK-BR-3 cells in the 10, 30 and 50 μmol/L PEITC treatment group were decreased in turn with the increase of concentration. The results of TUNEL and flow cytometry methods showed that the apoptosis rates of SK-BR-3 cells in the 10, 30 and 50 μmol/L PEITC treatment group were increased in turn with the increase of concentration. The results of Western blot and qRT-PCR methods showed that the protein and mRNA expression levels of anti-apoptotic indexes (Bcl-2, MCL-1) were decreased with the increase of concentration, while the expression levels of protein and mRNA of the pro-apoptotic index (Bax) and ERS-related indexes (PERK, eIF2α, CHOP, IRE1α, ATF6α) increased with the increase of concentration. ConclusionFrom the preliminary results of this study, PEITC can promote the apoptosis of breast cancer SK-BR-3 cells and inhibit cell proliferation, which might be achieved by regulating the expression levels of indexes related apoptosis and ERS.
ObjectiveTo study the expression of apoptosissuppressing gene (bcl2) and apoptosispromoting gene (bax) in colorectal cancerous tissue and transitional mucosas. MethodsColorectal cancerous tissue, transitional mucosas (3 cm from the cancerous tissue) and normal tissue were taken respectively in thirtyone cases. Immunohistochemical technique SP method was used to detect the expression in those tissues. ResultsThe positive expression rate of bcl2 protein in cancerous tissue and transitional mucosa were 64.5%and 60.0% respectively and significantly higher than that in normal tissue (P＜0.05). The positive expression rate of bcl2 protein in normal tissue was 35.0%. The positive expression rate of bax protein in cancerous tissue and transitional mucosa were 45.2%and 45.0% respectively and significantly lower than that in normal mucosa (P＜0.05). The positive expression rate of bax protein in normal tissue was 60.0%. There was no obvious difference in the positive rate of bax and bcl2 protein between cancerous tissue and transitional mucosa (Pgt;0.05). The expression rate of bax and bcl2 protein in colorectal cancer was irrelative to clinical pathological gradation and clinical stage (Pgt;0.05). ConclusionThere is over expression of bcl2 protein and low expression of bax protein in colorectal cancer and transitional mucosa. bcl2 protein and bax protein can affect the generation of colorectal cancer by participating in the regulation of apoptosis. But it is irrelative to clinical pathological gradation and clinical stage. Transitional mucosas should be viewed as precancerous lesion and resected during operation.
Objective To investigate the mechanism of the resistance of pancreatic cancer cells to tumor necrosis factor related apoptosis inducing ligand (TRAIL)mediated apoptosis. MethodsThe expression of TRAIL receptor-4 (TRAIL-R4) in normal pancreas tissue and pancreatic cancer was analyzed by using Northern blotting, Western blotting and immunohistochemistry.ResultsTRAIL-R4 mRNA and protein were expressed at moderate to high levels in human pancreatic cancer, but demonstrated weak to negative in the normal pancreas. Moreover, pancreatic cancer cells showed b TRAIL-R4 immunostaining throughout the tumor mass. Conclusion TRAIL-R4 levels are significantly different in pancreatic cancer in comparison to the normal pancreas. These findings give new insights into the resistance mechanisms of pancreatic cancer cells towards TRAILmediated apoptosis.
Abstract： Objective To investigate the effects of calcium preconditioning (CP) on immature myocardial cell apoptosis and apoptosisregulated proteins. Methods The experiment was carried out from June 2000 to December 2001 in the Renmin Hospital of Wuhan University. Twelve rabbits with the age of 1421 d and the weight of 230300 g were divided into 2 groups with 6 in each group by random digital table. For rabbits in the ischemia/reperfusion group (I/R group), after Langendorff models were routinely set up, KrebsHenseleit (KH) solution was perfused for 20 minutes and reperfused for 120 minutes after 45 minutes of ischemia. For rabbits in the CP group, after Langendorff models were established, KH solution was perfused for20 minutes, and 45 seconds’ noncalcium KH solution perfusion and 5 minutes’ KH solution perfusion were repeated 3 times before 45 minutes of ischemia and 120 minutes of reperfusion of KH solution. In situ apoptosis identification and semiquantitative analysis were used to detect the myocardial cell apoptosis; agarose gel electrophoresis was used to detect the nucleosomal ladder of DNA fragments; and the expression of bcl-2, bax and fas were detected with Western blot method. Results The apoptosis rate for the CP group was lower than that of the I/R group (4.53%±1.22% vs. 12.30%±2.12%,t=7.780, P=0.000). Nucleosomal ladder of DNA fragments of the CP group was lower than that of the I/R group (OD value: 56 460±1 640 vs. 135 212±3 370,t=51.460,P=0.000). The expression of bcl-2 in the I/R group was lower than that of the CP group (OD value: 13 217±1 770 vs. 31 790±1 018,t=22.280, P=0.000). The expression of bax (OD value: 30 176±1 025 vs. 7 954±730, t=43.260, P=0.000) and fas (OD value: 29 197±1 233 vs. 8 140±867, t=34.220, P=0.000) in the I/R group was higher than that of the CP group. Conclusion CP can affect the expression of myocardial bcl-2, bax, and fas, and decrease immature myocardial cell apoptosis.
Objective To investigate the effect of ursolic acid on the proliferation and apoptosis of human osteosarcoma cell line U2-OS and analyze its mechanism. Methods Human osteosarcoma cell line U2-OS was divided into 4 groups, which was cultured with ursolic acid of 0, 10, 20, and 40 μmol/L, respectively. At 0, 24, 48, and 72 hours after being cultured, the cell proliferation ability was detected by cell counting kit 8 (CCK-8). At 48 hours, the effects of ursolic acid on cell cycle and apoptosis of U2-OS cells were measured by flow cytometry. Besides, the expressions of cyclin D1 and Caspase-3 were detected by real-time fluorescent quantitative PCR and Western blot. Results CCK-8 tests showed that the absorbance (A) value of each group was not significant at 0 and 24 hours (P>0.05); but the differences between groups were significant at 48 and 72 hours (P<0.05). Flow cytometry results showed that, with the ursolic acid concentration increasing, the G1 phase of U2-OS cells increased, the S phase and G2/M phase decreased, and cell apoptosis rate increased gradually. There were significant differences between groups (P<0.05). Compared with the 0 μmol/L group, the relative expressions of cyclin D1 mRNA and protein in 10, 20, and 40 μmol/L groups significantly decreased (P<0.05); whereas, there was no significant difference in relative expression of Caspase-3 mRNA between groups (P>0.05). However, with the ursolic acid concentration increasing, the relative expressions of pro-Caspase-3 protein decreased and the relative expressions of activated Caspase-3 increased; there were significant differences between groups (P<0.05). Conclusion Ursolic acid can effectively inhibit the proliferation of osteosarcoma cell line U2-OS, induce the down-regulation of cyclin D1 expression leading to G0/G1 phase arrest, increase the activation of Caspase-3 and promote cell apoptosis.
ObjectiveTo observe apoptosis and proliferation of choledochus wall epithelial cell and fibrocyte, to understand the effects of apoptosis and proliferation on choledochal cyst development.MethodsThirty two cases of cystic dilatation,35 cases of cylindrical dilatation，and 25 cases of cholangiectasis caused by choledocholith were collected. All specimens were offered by department of hepatobiliarypediatric surgery. The apoptosis related index (bcl2 and bax) and cell proliferation index (PCNA) were detected by the immunohistochemical technique; Apoptosis was detected by TUNEL method. ResultsThere was serious mucosal epithelial cell damage in cystic dilatation group. In cylindrical dilatation group there was a damage similar to that of the cystis dilatation group, but the damage was not serious. In control group there was little damage in the duct wall, but there was a low positive rate of apoptosis of 〔epithelium cell (2.74±1.00)% and fibroblast (2.95±0.87）%〕, and a low bcl2 and bax’s expression rate, and a high PCNA’s expression rate 〔epithelium cell (3.74±1.00)%, fibroblast (3.71±1.77)%〕. There was no obvious difference between cylindrical dilatation group and cystic dilatation group (Pgt;0.05): the PCNA’s expression rate was low 〔(0.99±0.51)% and (0.90±0.38)% respectively〕, the bax expression rate was high in remaining epithelial cell, and the positive rate of bax was apparently higher than that of bcl2 (P＜0.05), the positive rate of the apoptosis cell was high 〔(13.94±4.77)%, (7.51±3.46)%〕; the expression rate PCNA were high 〔(9.91±2.91)%,(9.70±3.18)%〕, and expression rate of bax’s was low in the fibre tissue, the positive rate of bcl2 was markedly higher than that of bax, and the positive rate of the apoptosis cell was low 〔(3.74±2.12)%,(4.46±2.41)%〕. There were no marked difference between the two groups (Pgt;0.05). The expression of bcl2 and bax had marked difference both in cylindrical dilatation group and cystic dilatation group and as compared to control group (P＜0.05). ConclusionApoptosis has certain promoting effect in the course of choledochal cyst formation.
ObjectiveTo investigate the effects of dipyridamole (DP), one of the human equilibrative nucleoside transporters (hENTs) blockers, on 5-fluorouracil (5-FU) induced cell apoptosis and cell cycle changes of the pancreatic cancer Panc-1 cell line. MethodsPancreatic cancer cell line Panc-1 was divided into hENTs blocked group and hENTs unblocked group. The hENTs blocked group was further divided into two subgroups according to the DP concentration, 5 μmol/L DP group and 10 μmol/L DP group. Each group was incubated in culture medium with or without 1.5×106 ng/L 5-FU for 24 h. Cell apoptosis and cell cycle were detected by flow cytometry. Results①The apoptosis results of each group： Incubated in culture medium with 1.5×106 ng/L 5-FU for 24 h, the apoptosis rates of 5 μmol/L DP group and 10 μmol/L DP group were higer than those of hENTs unblocked group （Plt;0.05）, and which of 10 μmol/L DP group was higer than that of 5 μmol/L DP group (Plt;0.05). Incubated in culture medium without 5-FU for 24 h, there were no significant differences of the apoptosis rates among three groups (Pgt;0.05). ②The cell cycle results of each group: Incubated in culture medium with 1.5×106 ng/L 5-FU for 24 h, the percentages of S phase cells in the 5 μmol/L DP group and 10 μmol/L DP group were less than those of hENTs unblocked group (Plt;0.05). The percentage of S phase cell of 5 μmol/L DP group reduced to 87.09% and that of 10 μmol/L DP group reduced to 74.06% as compared with hENTs unblocked group. 5-FU had little influence on G2 phase (Pgt;0.05) except for the percentage of G2 phase cells in the 5 μmol/L DP group increased significantly (Plt;0.05) as compared with the hENTs unblocked group. Incubated in culture medium without 5-FU for 24 h, there were no significant differences of the cell cycles among three groups (Pgt;0.05). ConclusionsIn pancreatic cancer Panc-1 cell, DP could enhance the cytotoxicity of 5-FU by blocking hENTs. The enhanced cytotoxicity is related to elevation of 5-FU concentration in cells, and unrelated to DP itself.
Objective To investigate the inhibitory effect of survivin antisense oligonucleotides (ASODN) on proliferation of pancreatic cancer cells PANC-1. Methods The ASODN and sense oligodeoxynucleotides (SODN) were complementary to survivin sequences. FAM-marked ASODN was transfected into PANC-1 cells mediated by positive ion liposome as ASODN group. Blank control group (normal cells), negative control group (normal medium)， and SODN group were established for comparison. The transfection efficiency was detected by flow cytometry (FCM) after transfection; MTT assay was used to detect cytotoxicity; Cell morphological changes were examined by transmission electron microscopy; The cell cycle and apoptotic rate were analyzed by FCM; Immunohistochemical staining techniques were used, and the expressions of survivin were observed under light microscopy, examined and analysed by computer image. Results ①The transfection efficiency was 31.9%, 37.4%, 41.4%, 52.6%, 24.2%, 11.4%, 16.1%, and 15.5% when the transfecting concentration of ASODN was 50, 100, 150, 200, 250, 400, 600, and 800 nmol/L, respectively; The transfection efficiency was 12.0%, 50.8%, and 11.2% when the inoculated cells was 2×104/well, 2×105/well, and 2×106/well, respectively; The transfection efficiency was 58.8%, 34.0%, and 23.6% when 2 μl, 3 μl, and 4 μl liposome was used during transfection, respectively. ②Cell gap was oversize, morphous was round, adherent cells were less after transfection under fluorescence microscope. ③The inhibition rate in the ASODN group was higher than that in each control group (Plt;0.05) on 24, 36, 48 h after treating by survivin ASODN, which increased as time prolonged (Plt;0.05). ④The apoptosis showed a ladder-shaped line in the ASODN group. ⑤Apoptotic morphology was demonstrated in the ASODN group, such as apoptotic cells with nuclear chromatin highly concentrated, crescent nuclear staining aggregated by the side nuclear membrane, nucleolus disappeared by AO and EB stains. ⑥The apoptotic rate 〔（38.1±3.4）%〕 in the ASODN group was higher than that in the SODN group 〔（4.16±1.7）%〕, Plt;0.05. ⑦G2/M cell cycle arrested in the ASODN group. ⑧After transfection, the expression of survivin protein in the ASODN group was significantly lower than that of each control group (Plt;0.05). Conclusions The optimal transfection conditions are as following: the cell count of 2×105/well, concentration of ASODN 200 nmol/L, and cationic liposome oligofectamine 2 μl, respectively. Survivin ASODN can inhibit the proliferation of pancreatic cancer cells and induce their apoptosis.