ObjectiveTo study the effects of astaxanthin on the apoptosis after spinal cord injury in rats.MethodsOne hundred and forty-four healthy adult Sprague Dawley rats were divided into experimental group, control group, and sham group according to the random number table (n=48). In the control group and the experimental group, the modified Allen’s method was used to make the spinal cord injury model; in the sham group, only the lamina was cut without damaging the spinal cord. At immediate after operation, the rats in the experimental group were given intragastric administration of astaxanthin (75 mg/kg) twice a day; and the rats in the control group and the sham group were given equal amount of olive oil by gavage twice a day. BBB score was used to assess the motor function at 1 day and 1, 2, 3, and 4 weeks after operation. The malondialdehyde (MDA) content was determined by the thiobarbituric acid method at 24 hours after operation; and the activity of superoxide dismutase (SOD) was determined by the xanthine oxidase method. Apoptosis index (AI) was determined by TUNEL method at 6, 24, and 48 hours after operation. At 48 hours after operation, the water content of spinal cord was measured by dry-wet weight method, the lesion ratio of spinal cord was calculated, the ultrastructure of the spinal cord was observed by transmission electron microscopy, and ultrastructure scoring was performed using the Kaptanoglu score method.ResultsThe BBB score in the control group and the experimental group was significantly lower than that in the sham group at each postoperative time point (P<0.05); and the BBB score in the experimental group were significantly higher than that in the control group at 1-4 weeks postoperatively (P<0.05). The MDA content in the control group and the experimental group was significantly higher than that in the sham group at 24 hours after operation, and in the experimental group was significantly lower than in the control group (P<0.05). The SOD activity in the control group and the experimental group was significantly lower than that in the sham group, and in the experimental group was significantly higher than in the control group (P<0.05). At each time point postoperatively, the AI in the control group and the experimental group was significantly higher than that in the sham group, and in the experimental group was significantly lower than in the control group (P<0.05). At 48 hours after operation, the water content of spinal cord, the lesion ratio of spinal cord, and the ultrastructure score in the control group and the experimental group were significantly higher than those in the sham group, and in the experimental group were significantly lower than in the control group (P<0.05).ConclusionAstaxanthin can inhibit the lipid peroxidation, reduce the apoptosis, reduce the spinal cord edema, reduce the spinal cord lesion, reduce the histopathological damage after spinal cord injury, and improve the motor function of rats with spinal cord injury, and protect the spinal cord tissue, showing an obvious neuroprotective effect.
Objective To observe the outcomes of using different concentrations of arsenic trioxide at varying phases on the breast cancer cell line MCF-7 and to study the mechanism of this effect. Methods The effect of arsenic trioxide on the growth of breast cancer cell line MCF-7 was observed after applying arsenic trioxide of different concentrations （0.5-16 μmol/Ｌ）. The inhibitory effect of arsenic trioxide on the cell proliferation was investigated with 3-(4，5-dimethyl-thizazol-2-yl)-2， 5-diphenyl tetrazolium bromide (MTT) and the induction of arsenic trioxide on cell apoptosis was detected by DNA ladder and terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). Results The effect of arsenic trioxide on breast cancer cell line MCF-7 depended on the phase and the dose. The number of cell decreased significantly and there were conspicuously typical morphological changes of apoptosis after the use of arsenic trioxide， including membrane blebbing， chromatin pyknosis, nuclear fragmentation and the formation of apoptotic body. The typical DNA ladders were observed in the MCF-7 cells after 48 h administration of arsenic trioxide at concentrations 1-8 μmol/Ｌ. Significant elevations of apoptosis index at 24 h, 48 h and 72 h were all detected by TUNEL after incubating with 4 μmol/L arsenic trioxide. Conclusion Arsenic trioxide may inhibit the growth of breast cancer cell line MCF-7 significantly by inducing the apoptosis of breast cancer cell.
To study the effect of the proliferation and apoptosis of Survivin-T34A mutant on breast cancer MCF-7 cell, we adopted the method of cell culture in vitro to observe the proliferation and apoptosis of the cell. In the experiment, MCF-7 cells were randomly divided into three groups and transfected with normal saline, PORF-9-null and Survivin-T34A, respectively. Breast cancer nude mouse models were established to study anti-tumor effect of Survivin-T34A in vivo. The activity of the cells in the Survivin-T34A-transfected group was lower than that in PORF-9-null group. The increase of cell apoptosis was observed under electron microscopy, meanwhile the apoptotic rate was obviously higher than that in PORF-9-null control by flow cytometry. Tumor inhibition effects of the mouse which received the injection of Survivin-T34A intratumoral injection were apparent, and the inhibition ratio was as high as 47.1%. In conclusion, Survivin-T34A mutant has anti-tumor effect through efficiently inhibiting the growth of breast cancer MCF-7 cell and actively promoting apoptosis of cancer cells.
Objective To research the effect of γ-ray released from 103Pd radioactive stent on the expression of Fas gene and its relation with apoptosis of cholangiocarcinoma cell and the significances through the establishment of human cholangiocarcinoma model. Methods The model of nude mouse with implanted human cholangiocarcinoma was established. The mice were divided into study group and control group, 37 MBq 103Pd biliary stent was implanted in the study group and the ordinary metal biliary stent was implanted in the control group. The volume of tumor was measured, the cell apoptosis was detected by the TUNEL method and the expression of Fas gene of the cell apoptosis of the induced human cholangiocarcinoma was checked out by immunohistochemistry staining 10 d after the implantation. Results Compared with the control group, the growing speed of the volume of tumor in study group was significantly reduced (Plt;0.05), the expression positive rate of Fas gene was significantly higher (Plt;0.05), and the apoptotic rate of cancer cells was also higher (Plt;0.01). Conclusions The 103Pd radioactive stent can induce the cell apoptosis in nude mouse model with implanted human cholangiocarcinoma inhibit the cell growth of bile duct cancer and may promote the apoptosis of cancer cells by increasing the expression of Fas gene. It may be helpful for the further study of treatment for bile duct cancer using 103Pd radioactive stent.
Objective Endoplasmic reticulum stress (ERS) mediated apoptosis is one of the eukaryotic cellularapoptotic pathways, to investigate the potential role of ERS during myocardium apoptosis in rats with severe burninjury. Methods Sixty-four 7-week-old male Wistar rats, weighing 200-220 g, were randomly divided into 2 groups. Thirtypercentage of total body surface area full-thickness thermal injury was produced in 32 rats of burn group, while sham burn wasproduced in 32 rats of control group. The heart tissues were harvested from 8 rats in each group at 1, 4, 7, and 14 days after burnto observe the changes of myocardium ultrastructure with transmission electron microscope (TEM). Myocardium apoptosis wasdetected with TUNEL assay. The expressions of glucose regulated protein 78 (GRP 78), C/EBP-homologous protein (CHOP),and cleaved Caspase 12 in different pathways of ERS were analysed with Western blot. Results All rats survived during theexperiment. Apoptotic changes of cardiomyocytes were observed in burn group, and the apoptosis index in burn group wassignificantly higher than that in control group at each time point (P lt; 0.05), and it reached peak at 7 days after burn injury(P lt; 0.05). The expressions of myocardial GRP 78, CHOP, and cleaved Caspase 12 showed persistent elevation in burn group.The expressions of GRP 78 and cleaved Caspase 12 in burn group were significantly higher than those in control group at eachtime point (P lt; 0.05), while the expression of CHOP was higher than that in control group at the other time points (P lt; 0.05)except 1st day after burn injury. Conclusion ERS and CHOP, Caspase 12 mediated apoptotic pathway are activated inmyocardium after severe burn injury, and this may be one pathway of myocardium apoptosis.
Objective To investigate the role of chemokine receptor CXCR7 in the development and progression of pancreatic carcinoma. Methods The short hairpin RNA (shRNA) targeting CXCR7 was designed and delivered into AsPC-1 pancreatic carcinoma cells to knock down CXCR7 expression. The cell proliferation, cell cycle, and apoptosis after CXCR7 knockdown was determined by MTT and flow cytometry, respectively. The invasive ability of pancreatic carcinoma cells was evaluated by using the Transwell system. Results Compared with the blank control group (BC group), transfection of AsPC-1 cells with CXCR7-shRNA resulted in a significantly decreased expression of CXCR7 at both mRNA and protein levels (P<0.05), and the ability of proliferation and invasion significantly decreased (P<0.05). Knockdown of CXCR7 also significantly increase apoptosis (P<0.05), induce cell cycle arrest at G0/G1 phase (P<0.05). Conclusions Taken together, the present study showes that the knockdown of CXCR7 expression may play an important role in pancreatic carcinoma development, invasion, and metastasis, CXCR7 may be a potential therapeutic target for the treatment of pancreatic carcinoma.
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 introduce the relationship between the apoptosis hepatocyte and its genic mediation and the ischemia of portal vein. MethodsThe combination of related literatures and our research findings were made.ResultsPortal vein ischemia may induced hepatocyte apoptosis, p53 and bcl2 gene alternatively adjust hepatocyte apoptosis. Expression of p53 gene is enhanced in hepatic tissue when hepatocyte apoptosis is not obvious, but after 24-72 h of portal vein ischemia, when hepatocyte apoptosis is obvious, enhanced expression of p53 gene or reduced expression of bcl2 gene occur. There exists close relationship between portal vein ischemia and hepatocyte apoptosis. Conclusion Apoptosis hepatocyte is involved in organic atrophy after ischemia of portal vein, and p53 and bcl2 gene alternatively adjust hepatocyte apoptosis. At present, the mechanism of apoptosis of hepatocyte induced by ischemia of portal vein is not clear, which needs further study.
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.
ObjectiveTo study the role of survivin gene in the research work of tumor. MethodsLiteratures about the molecular structure, function, mechanism,distribution of survivin gene and its role in the treatment of tumor were reviewed.ResultsSurvivin was a new member of inhibitor of apoptosis protein family, expressed in almost all the human tumors independent to the expression of bcl2. The expression of survivin was significantly correlated with the poor prognosis of tumor patients. Survivin inhibited the apoptosis of tumor cells via inhibiting the activity of caspase3, the effector molecule of the apoptosis signal transduction pathway. Inhibition of the expression of survivin gene could block its effect of inhibiting apoptosis and consequently get a therapeutic effect of tumors.ConclusionSurvivin is commonly expressed in human tumor tissues. It can be identified as an important prognostic parameter of poor outcome and a new therapeutic target in cancer.