Objective To investigate the inhibitory effects of RNA interference (RNAi) expression vector on the expression of survivin in pancreatic cancer cell PANC-1. Methods The protein and mRNA expressions of survivin were examined with immunofluorescence and RT-PCR. The survivin gene was cloned into the T-vector and sequenced. The RNAi expression vectors targeting survivin, named si-svv-1 and si-svv-2 respectively according to whether they harbored a mutation or no mutation, were constructed and transfected into PANC-1 cells with liposome. The expression of survivin mRNA was detected with RT-PCR. Apoptosis of PANC-1 cells was analyzed with DNA ladder and FACS. Results There was a high degree expression of survivin in PANC-1 cells. The expression of survivin was not inhibited by RNAi expression vectors si-svv-1, but inhibited about (72.43±8.04)% by si-svv-2 and the apoptosis rate of PANC-1 cells increased to （12.36±1.44）% after 72 h. Conclusion The RNAi expression vector can effectively inhibit the expression of survivin in pancreatic cancer cell PANC-1 cells and induce the apoptosis in PANC-1 cells.
OBJECTIVE: To investigate apoptosis of chondrocytes cultured in vitro and related expression of caspase-3. METHODS: Apoptosis of chondrocytes were detected by flow cytometry analysis and TUNEL staining. The expression of caspase-3 was determined by RT-PCR and Western blot, and caspase-3 protein activity was determined by ELISA. RESULTS: Apoptosis was observed in chondrocytes cultured in vitro from passage 1 to passage 4 at various degrees. The percentage of apoptosis of chondrocytes on day 7 was much higher than that on day 3 (15.7% +/- 0.3% vs 8.9% +/- 0.6%, P lt; 0.01). caspase-3 mRNA and protein expressed in chondrocytes during whole culture process. Along with the culture time extension in vitro, caspase-3 expression and protein activity up-regulated, coincident with apoptosis of chondrocyte. caspase-3 was activated and a fragment of 20 kDa was detected after 7 days of culture. CONCLUSION: caspase-3 is involved in apoptosis of chondrocytes cultured in vitro.
Objective To evaluate the phenomena of apoptosis and its relevant mechanism during ischemia-reperfusion period. Methods The published papers to explore the apoptotic phenomena and its mechanism in organs or tissues which experienced ischemia-reperfusion injury were reviewed. Results Apoptosis was common in ischemia-reperfusioned organ or tissue. The severity of apoptosis was influenced by many factors such as ischemia, hypoxia, oxygen free radials, intracellular free calcium ion overloading, various cytokines, et al; and also was regulated by bcl-2 family, caspase family and NF-κB，et al. Conclusion Apoptosis is a common phenomenum in ischemiareperfusioned organ or tissue which is affected and regulated by various factors.
Objective To study the effect of low-dose cyclophosphamide (CY) on apoptosis of lung parenchyma cells in the early severe burn stage in rats. Methods Ninety clean SD male rats were randomly divided into 3 groups: the normal group (n=10), the experimental group (n=40) and the burn group (n=40). The model of degree III with 30% burn area was made in the experimental group and the burn group. CY (2 mg/kg) was injected into the abdominal cavity right after burn in the experimental group. No treatment was done in the normal group and burn group. Lung tissues were obtained at 3, 6, 12and 24 hours, respectively, after burn, and were observed by HE staining. Apoptosis of lung parenchyma cells was observed by TUNEL. Results Lung tissues were observed under the opticalmicroscopy in the normal group: the pulmonary structure was clear, and there were no inflammatory cells and exudation in the alveolar space and bronchial lumen. Besides, a few RBCs were seen. Pathological changes of lung tissues were observed under the opticalmicroscopy in the burn group: alveolar septum was obviously widened; alveolar wall was destroyed; interstitial edema and atelectasis occurred; and pathological lesion was gradually aggravated as time passed by. The pathological lesion of lung tissues mentioned above in the experimental group was better than those in the burn group. Compared with the normal group, the apoptosis ratio of lung parenchyma cells continuously increased in the burn group from the 3 hour after burn, and reached the peak at 12 hours. There were significant differences between the two groups (P lt; 0.05). However, in the experimental group, the apoptosis ratio of lung parenchyma cells increased at 3 hours after burn, cut down to normal at 6 and 12 hours, respectively, and notably decreased at 24 hours. There were significant differences between the experimental group and the normal group (P lt; 0.05). Compared with the burn group, the apoptosisrate of lung parenchyma cells in the experimental group began to decrease strikingly from the 6 hours after burn, and there were significant differences between the two groups (P lt; 0.05). Conclusion Low-dose CY can restrain the apoptosis of lung parenchyma cells in the early severe burn stage in rats and alleviate the injury of the lung.
To evaluate the significance of bcl-2 protein, estrogen receptor (ER), progesterone receptor (PR) and p53 oncogene in invasive breast cancer of ductal and lobular type. Tumor tissues were examined immunohistochemically in paraffin embedded tissues from 125 patients. Results: The invasive ductal breast carcinomas expressed bcl-2 protein significantly less frequently than the lobular type (Ｐ＜0.001). And the expression of bcl-2 protein was significantly correlated with ER, PR (Ｐ＜0.001) and p53 (Ｐ＜0.001), also correlated with primary tumor size and grade. No statistical evidence was found to indicate the relationship between bcl-2 protein expression and anxillary lymph node metastasis. Conclusions: The expression of bcl-2 protein may be regarded as a biological index and may play important role in evaluating the biological characteristics of breast cancer.
Objective To study the effect of water soluble chitosan (WSC) on the apoptosis of peritoneal macrophage induced by lipopolysaccharides (LPS), and discuss the mechanism. Methods Peritoneal macrophages were divided to three groups: phosphate buffered saline (PBS) group, LPS group and LPS plus WSC group. At hour 24, apoptosis cell and active caspase-3 were detected by flow cytometry; nitric oxide (NO) was determined with Griess reagent. Results There were more apoptosis cells in the LPS group than the PBS group. The percentage of apoptosis cells was significantly decreased in the LPS plus WSC group than the LPS group. The expression of active caspase-3 and the secretion of NO were also inhibited by WSC after LPS intervention. Conclusion WSC inhibits apoptosis of peritoneal macrophage induced by LPS.
【Abstract】 Objective To investigate the effect of retinoic acid (RA) on cell apoptosis and gene regulation of IGF-2in chondrocyte. Methods One 1-month-old Chinese rabbit weighted 500 g was used in this experiment. The chondrocyte from rabbit knee were cultured by enzyme digestion. Twenty-five μL all-trans-retinoic acid (ATRA) (1×10-6 mol/L) were added in the media of cultured chondrocyte for 24 hours as experimental group, while 25 μL DMEM were added as control group. The secretion of collagen Ⅱ was observed by immunohistochemistry method, cell apoptosis was detected by flow cytometry, IGF-2 mRNA and protein expression in chondrocyte were detected by RT-PCR and Western blot analysis. Results The expression of collagen Ⅱ was down-regulated by ATRA in the experimental group. The cell apoptosis in chondrocyte exposed to ATRA at 1 ×10-6 mol/L was 21% ± 2%, which increased 5 times compared with the control group（5% ± 1%）. The IGF-2 mRNA and protein level in the experimental group were decreased 75% and 57%, respectively, compared to the control group. There weresignificant difference between the experimental group and control group in each index (P lt; 0.05). Conclusion RA may down-regulate the secretion and cell prol iferation, but up-regulate the cell apoptosis in chondrocyte. The apoptotic effect may carry out through inhibiting the IGF-2 expression of chondrocyte.
Objective To investigate the temporal and spatial expression pattern of Caspase3、Bax and Bclxl in NmethylNnitrosourea (MNU) damaged rat retina. Methods Twenty-four 50 dayold female Sprague-Dawley rats (n=24) received single intraperitoneal injection of MNU 40 mg/kg and were examined at 1, 3, 7 and 10 days after MNU treatment (6 rats sacrificed at each timepoint). As control, six rats were injected with saline (5 ml/kg) and sacrificed 3d after injection. Expressions of Caspase-3 and bax and bcl-xl were detected by RTPCR and immunofluorescence assays, photoreceptor cell apoptosis was measured by terminal deoxynucleotidyl transferasemediated deoxyuridine triphosphatedigoxigenin nick-end labeling (TUNEL). Results Animal models were successful established and confirmed by pathological studies. RTPCR results indicated that caspase3 and bax upregulated at 1 d (caspase-3 RA =83.23plusmn;8.11，P= 0.009; bax-RA=72.73plusmn;9.46，P=0.004) and peaked at 3 d （caspase-3 RA=140.48plusmn;18.40，P=0.000；bax-RA=102.36plusmn;13.97，P=0.001）compared with control (caspase-3 RA=62.45plusmn;7.65; bax-RA =46.53plusmn;4.41). Bcl-xl expression increased and peaked at 3d (3d RA=79.83plusmn;5.58, P=0.000 vs control 45.98plusmn;3.06). It was noted that the ratios of bax / bclxl expression at 1 d, 3 d and 7 d after MNU injection were enhanced (1 d 1.15plusmn;0.14, P= 0.143; 3 d 1.28plusmn;0.16, P=0.001; 7 d 1.17plusmn;0.08, P= 0.079, vs control 1.01plusmn;0.09), and at 3 d the ratio reached the peak, whereas at10 d bax / bcl-xl ratio (0.73plusmn;0.07, P= 0.001) was decreased compared with the control. Immunofluorescence assays demonstrated that the changes of bax, bclxl and caspases3 protein expressions coincided with their RTPCR results respectively. The Bax positive cells were detected in the outer nuclear layer; while caspase3 and bclxl positive cells emerged in several layers of retina included the pigment epithelium layer, the photoreceptor cell inner segments, the outer nuclear layer, the outer plexiform layer, the inner plexiform layer and the ganglion cell layer. Photoreceptor cell apoptosis was only detected in the outer nuclear layer and peaked at 3 d in MNU treated rats (AI= 76.97plusmn;5.83, P= 0.000 vs control 0.00 plusmn; 0.00). Conclusions These data suggest that bax and bcl-xl and caspases3 may involve in the MNUinduced rat photoreceptor cell apoptosis.
Objective To investigate the expression of multigenes mediated by adenovirus in liver cancer cells and the effects on growth of cells transducted with multigenes. MethodsBy construction of recombinant adenovirus containing human p53, B7-1, GM-CSF, and IL-2 genes (Ad-multigenes), the expression level of target genes in three human hepatocellular carcinoma cell lines and a human hepatocellular cell line L02 was detected using ELISA, immunohistochemistry and FACS assay and the change of growth of these cells and the tumor cell apoptosis were observed. Results The human hepatic cells and liver cancer cells were all sensitive to adenovirus infection. At a MOI of 50 PFU/cell, among the cells examined nearly 90% were positive expression and except IL-2, other three genes were expressed with high efficiency. The growth of Ad-multigenes-transduced liver cancer cell lines was inhibited and apoptosis was induced, but the growth of Ad-multigenes-transduced normal hepatic cell line L02 did not change. Conclusion These results indicate that the adenovirus is an efficient vector for gene transfer into human liver cancer cells. These liver cancer cell lines transduced with multigenes constructed on one recombinant adenoviral vector can highly express target genes and their growth was inhibited, and apoptosis appeared.
Objective To study hyperthermia induced apoptosis and the effect of aspirin on hyperthermia induced apoptosis in retinoblastoma cells. Methods Retinoblastoma cells (Y79) were divided into two groups:hyperthermia groups,hyperthermia+aspirin (0.18～18mu;g/ml) groups.Heat shock condition:44℃,heat shock time:10,20,30, and 40 minutes respectively.The following events were studied after heat shock by using FAC Scan: ①cell apoptosis; ②heat shock protein 70 (HSP70) expression；③bcl-2 expression. Results Apoptosis was induced by the treatment of hyperthermia (44℃) in Y79 cells in a heat dose dependent fashion.Longer time heating (44℃，40 minutes) induced necrosis rather than apoptosis.Aspirin could rescue Y79 cells from hyperthermia induced apoptosis in a dose dependent manner．HSP70 was induced in Y79 cells after heat shock,it was further enhanced by the treatment of aspirin(＞1.8mu;g/ml).Heat shock itself showed no effect on bcl-2 expression in Y79 cells,aspirin,on the other hand,could enhance bcl-2 expression in a modest level in heat treated Y79 cells. Conclusions Hyperthermia may induce apoptosis in Y79 cells which can be protected by use of aspirin．The enhancement of HSP70 and bcl-2 expression in Y79 cells by the treatment of aspirin in heating condition may be responsible for the protective function. (Chin J Ocul Fundus Dis, 1999, 15: 143-145)