Advantages of McKeown minimally invasive oesophagectomy for the treatment of oesophageal cancer: propensity score matching analysis of 169 cases.

BACKGROUND: Oesophagectomy, the gold standard for oesophageal cancer treatment, causes significantly high morbidity and mortality. McKeown minimally invasive oesophagectomy (MIE) is preferred for treating oesophageal malignancies; however, limited studies with large sample sizes focusing on the surgical and oncological outcomes of this procedure have been reported. We aimed to compare the clinical safety and efficacy of McKeown MIE with those of open oesophagectomy (OE). PATIENTS AND METHODS: Overall, 338 oesophageal cancer patients matched by gender, age, location, size, and T and N stages (McKeown MIE: 169 vs OE: 169) were analysed. The clinicopathologic features, operational factors, postoperative complications, and prognoses were compared between the groups. RESULTS: McKeown MIE resulted in less bleeding (200 mL vs 300 mL, p<0.01), longer operation time (335.0 h vs 240.0 h, p<0.01), and higher number of harvested lymph nodes (22 vs 9, p<0.01) than OE did. Although the rate of recurrent laryngeal nerve injury in the two groups was not significantly different, incidence of anastomotic leakage (8 vs 24, p=0.003) was significantly lower in the McKeown MIE group. In addition, patients who underwent McKeown MIE had higher 5-year overall survival than those who underwent OE (69.9% vs 40.4%, p<0.001). CONCLUSION: McKeown MIE is proved to be feasible and safe to achieve better surgical and oncological outcomes for oesophageal cancer compared with OE.

HABP1 promotes proliferation and invasion of lung adenocarcinoma cells through NFκB pathway.

The aim of this research was to investigate the role of hyaluronan-binding protein 1 (HABP1) in lung adenocarcinoma. It was demonstrated by bioinformatics analysis that HABP1 was one of the differentially expressed genes in lung adenocarcinoma. Then, it was confirmed by qPCR, western blot, and immunohistochemistry analysis that HABP1 was upregulated in human tissue specimens we collected. Survival analysis showed that HABP1 was promised to serve as a new biomarker to predict the progress and prognosis of lung adenocarcinoma patients. In addition, we further studied the effects of regulating the expression of HABP1 on lung adenocarcinoma cells, indicating that altered expression of HABP1 could adjust cell proliferation and invasion through the NFκB signaling pathway.

Integrative analysis of differential circular RNA and long non-coding RNA profiles and associated competing endogenous RNA networks in esophageal squamous cell carcinoma.

Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) play vital roles in the tumorigenesis of esophageal squamous cell carcinoma (ESCC). Nevertheless, the mechanism and regulatory network associated with this process remain largely unknown. In this study, we performed a comprehensive analysis of the expression of mRNAs, lncRNAs, and circRNAs by RNA-seq. A total of 3265 mRNAs, 1084 lncRNAs, and 38 circRNAs were found to be differentially expressed. Among these, 269 mRNAs were found to encode transcription factors (TFs). Functional enrichment analysis indicated that the dysregulated TFs are associated with the Hedgehog, Jak-STAT, TGF-beta, and MAPK signaling pathways. Furthermore, we constructed co-expression networks to screen the core lncRNAs and circRNAs involved in the regulation of transcription factors in these four pathways. Finally, we constructed a competing endogenous RNA (ceRNA) network of ESCC based on the abovementioned pathways. Our findings provide important insight into the role of lncRNAs and circRNAs in ESCC; the differentially expressed lncRNAs and circRNAs may represent potential targets for ESCC diagnosis and therapy.

Ubiquitin specific peptidase 49 inhibits non-small cell lung cancer cell growth by suppressing PI3K/AKT signaling.

Ubiquitin specific peptidase 49 (USP49) has been reported as a tumor suppressor in several tumors, but its function and molecular mechanism in non-small cell lung cancer (NSCLC) are still unknown. In this study, USP49 was found downregulated in NSCLC primary tissues and cell lines, and high USP49 predicted a positive index for the overall survival of NSCLC patients. Overexpression of USP49 downregulated the expression levels of Cyclin D1, and upregulated p53 expression. Further flow cytometry analysis showed that overexpressed USP49 induced cell cycle arrest at G0/G1 phase. As a result, overexpression of USP49 significantly inhibited cell growth of NSCLC cells. In mechanism, overexpression of USP49 inhibited PI3K/AKT signaling, but knockdown of USP49 enhanced this signaling. Further studies indicated that USP49 deubiquitinated PTEN and stabilized PTEN protein, which suggested that USP49 inhibited PI3K/AKT signaling by stabilizing PTEN in NSCLC cells. In conclusion, we demonstrated that USP49 was functional in NSCLC cells, and inhibited NSCLC cell growth by suppressing PI3K/AKT signaling, suggesting that USP49 could be as a novel target for NSCLC therapy.

Microenviromental change after synthetic E-selectins interfere in ischemia-reperfusion in rats and its contribution to endogenetic/exogenous never stem cells.

OBJECTIVE: To explore the special significances in advantages of using anti-inflammatory drugs, such as amelioration of growing conditions and the promotion of cell growth. METHODS: Utilizing anti-adhesive effects of synthetic E-selectins, we observed the changes of inflammatory cytokines (TNF-α, IL-1ß) contented in brain tissues and rat serums in rats hind cerebral ischemia-reperfusion models. Both growth and expression of endogenetic/exogenous neurological stem cells were detected after ameliorated local microenvironment. RESULTS: The contents of TNF-α and IL-1ß were decreased in brain tissues and rat serums after applying synthetic E-selectins. Expression of exogenous neurological stem cells was enhanced. Animal neurological functions improved. CONCLUSION: Anti-inflammatory therapy in early stage could enhance proliferation of stem cells so that it has vital significations in treating cerebrovascular diseases.

Significance of Fas and FasL protein expression in cardiac carcinoma and local lymph node tissues.

OBJECTIVE: To investigate the relation of Fas and Fas ligand (FasL) protein expression with carcinogenesis and metastasis of cardiac carcinoma. METHODS: Immunohistochemistry was used to detect Fas and FasL protein expression in 64 cardiac carcinoma tissue samples and 20 normal gastric tissue samples. Relation between FasL and Fas expression, age and gender of gastric cancer patients, and pathological subtype and lymph node metastasis of gastric cancer was analyzed. RESULTS: The Fas expression level was significantly higher in normal gastric tissue samples than in cardiac carcinoma tissue samples (85.0% vs. 25.0%, P<0.001), while the FasL expression level was significantly lower in normal gastric tissue samples than in cardiac carcinoma tissue samples (30.0% vs. 81.3%, P<0.001). The Fas expression level was significantly higher in invasive lymph nodes than in non-invasive lymph nodes (82.9% vs. 56.5%, P<0.003) and in well-differentiated gastric carcinoma tissue samples than in poorly-differentiated cardiac carcinoma tissue samples (50.0% vs. 18.0%, P=0.015). The FasL expression level was significantly lower in well-differentiated cardiac carcinoma tissue samples than in poorly- differentiated cardiac carcinoma tissue samples (42.9% vs. 84.0%, P=0.021). The Fas and FasL expression levels (25.0% and 81.3%) were significantly different in cardiac carcinoma tissue samples (P<0.001), but had a non-linear correlation (P=0.575). CONCLUSION: Abnormal Fas and FasL expressions in cardiac carcinoma and lymph node tissues are involved in carcinogenesis and metastasis of gastric cancer.

Clinicopathological significance of Fas and Fas ligand expressions in esophageal cancer.

Esophageal carcinomas have recently been shown to express Fas ligand (FasL) and down-regulate Fas to escape from host immune surveillance. However, the prognostic importance of Fas/FasL and their correlation with clinicopathological characteristics are yet to be delineated in this highly malignant carcinoma. Specimens from 106 esophageal squamous cell carcinoma patients were used for immuno-histochemical evaluation of Fas, FasL, and CD8 expressions. Fifty-two (49%) and 34 (32%) patients were positive for FasL and Fas, respectively. There were no associations between FasL expression and clinicopathological characteristics except lymph vessel invasion. Strong FasL expression correlated with significant (P < 0.001) decrease in tumor nest CD81 cells. However, neither FasL nor CD81 had any impact on patient survival. Strong Fas expression was correlated with depth of invasion (40.3% in pT1, T2 versus 20.5% in pT3, T4; P5 0.0308), histological differentiation (45.7% in well versus 25.4% in nonwell; P < 0.05), and lymph node metastasis (22.6% in positive versus 45.5% in negative; P < 0.01). Fas expression was one of the independent favorable prognosticators for patients' survival (risk ratio, 3.26; P < 0.01) in esophageal SCC. Fas expression was an independent prognosticator for recurrencefree survival, whereas FasL expression did not influence the survival in esophageal squamous cell carcinoma. Down-regulation of tumor Fas may be the hallmark of immune privilege for the tumor, thus causing the patients' poorer outcome. Tumor FasL may counterattack the host immune cells to such an extent that the prognosis is not affected.

Adenovirus-mediated IL-24 confers radiosensitization to human lung adenocarcinoma in vitro and in vivo.

The current paper aims to study the effect of adenovirus-mediated IL-24 (Ad-IL-24) on human lung adenocarcinoma in vitro and in vivo and determine its possible mechanism of action. The growth-suppressing and apoptosis-inducing effects of Ad-IL-24, radiotherapy, and Ad-IL-24+ radiotherapy (hereinafter referred to as the joint group) on SPC-A1 lung carcinoma cells were assessed by using 3-(4,5-dimethyliazolyl-2)-2,5-diphnyltetrazolium bromide and flow cytometry. A human lung model was established with SPC-A1 cells in nude mice. Groups of mice were subjected to multi-point injections to their tumors. Gross tumor volumes were measured dynamically. The ratios of tumor suppression and radiosensitization effect were evaluated according to the method of probability sum Q values. The expressions of Bax, Bcl-2, Survivin, and Caspase-3 in tumor samples were detected by immunohistochemistry. The ratios of inhibition and apoptosis in the joint group were higher than those in the individual Ad-IL-24 and radiotherapy groups. In vitro, the joint group suppressed tumor growth conspicuously, showing a weight inhibition rate of about 64 %. The expressions of FasL, Bax and Caspase-3 were upregulated in the joint group, while the expressions of Cox,Bcl-2,VEGF,CD34 and Survivin were downregulated. The current study proves that Ad-IL-24 suppresses growth of SPC-A1 cells both in vitro and in vivo. Its functions appear to be related to cell apoptosis and antiangiogenesis.

Relationship of Fas, FasL, p53 and bcl-2 expression in human non-small cell lung carcinomas.

OBJECTIVE: Lack of surface Fas expression is a main route for apoptotic resistance which is considered an important mechanism of tumorigenesis and tumor progression. Fas and FasL expression in 110 non-small cell lung carcinomas (NSCLCs) were investigated to evaluate their roles in pulmonary carcinogenesis and to examine the clinicopathologic significance of Fas expression with its relationship with p53 and bcl-2 over- expression. METHODS: Immunohistochemical analysis using tissue microarray demonstrated that a large proportion of NSCLC patients (60%) showed lack of membranous Fas expression. The Fas-negative cases revealed the significantly lower survival rate than Fas-positive ones. Also, the loss of Fas receptor expression was found more frequently in advanced stage and higher nodal status. FasL protein was increased in most NSCLCs (89%) compared to normal lungs. RESULTS: p53 and bcl-2 overexpression showed no association with Fas expression. Conclusively, reduced membranous Fas expression as a mechanism of apoptotic resistance is considered to play an important part of the pulmonary carcinogenesis, which may predict poor survival and have a negative prognostic influence. CONCLUSION: Increased FasL expression is thought to be a basis for the immune evasion in NSCLCs. The rare bcl-2 overexpression suggests that this anti-apoptotic protein is unlikely to play a role in the apoptotic resistance of NSCLCs.

Experimental studies of erythropoietin protection following traumatic brain injury in rats.

This study aimed to explore the effect of erythropoietin (EPO) on brain tissue after traumatic brain injury in rats. Animals were divided into sham, control and EPO groups. The model was constructed using the improved Feeney's free falling weight traumatic brain injury model. The brain water content and the number of the apoptotic monocyte chemotactic protein-1(+) (MCP-1(+)) and CD68(+) cells were monitored at 12, 48 and 120 h post-trauma. The water content was lower in the EPO group at each time point compared to the control group. The number of apoptotic MCP-1(+) and CD68(+) cells surrounding the traumatic brain injury lesion was less in the EPO group compared to these values in the control group. In conclusion, following traumatic brain injury, EPO significantly decreased the number of apoptotic cells, the expression of MCP-1, the infiltration of CD68(+) cells as well as brain edema to protect the brain.

Transplantation of human amniotic mesenchymal stem cells in the treatment of focal cerebral ischemia.

Cerebrovascular injury is one of the three major causes of death and is the leading cause of adult disability. Despite the increasing progress in emergency treatment and early rehabilitation in patients with cerebrovascular injury, treatment options for neurological dysfunction that presents at a later stage are lacking. This study examined the potential of human amniotic mesenchymal stem cell (hAMSC) transplantation in the repair of neurological deficits in an experimental focal cerebral ischemia model. Following the isolation of hAMSCs, growth characteristics and surface antigen expression were observed. Butylated hydroxyanisole (BHA) was used to induce the cultured cells into neuron-like cells, which were identified by immunocytochemistry. The suture model was used to induce focal cerebral ischemia in rats, which were subsequently randomly divided into experimental and control groups for treatment with BrdU-labeled hAMSCs or PBS, respectively. Neurological deficits were assessed following transplantation using the neurological severity score, beam balance test and elevated body swing test. Eight weeks later, rat brain tissue was analyzed with H&E staining and BrdU immunohistochemistry, and the survival and spatial distribution of the transplanted hAMSCs were determined. The hAMSCs proliferated in vitro, and it was found that neuron-specific enolase (NSE) was expressed in neurons, whereas glial fibrillary acidic protein (GFAP) was expressed in astrocytes. The focal ischemia model caused varying degrees of left limb hemiplegia accompanied by right sided Horner's Syndrome. When examined 1, 3, 6 and 8 weeks later, significant recovery in neurological behavior was detected in the rats treated with hAMSC transplantation compared with the control (P<0.01). BrdU-labeled hAMSCs were concentrated near the graft site and surrounding areas, in certain cases migrating towards the ischemic lesion. Local gliosis and lymphocytic infiltration were not detected. hAMSCs exhibit great potential for proliferation and are induced to differentiate into NSE-expressing neuron-like cells following treatment with BHA. Moreover, hAMSC transplantation may improve neurological symptoms following focal cerebral ischemia.

Human placenta-derived mesenchymal stem cells with silk fibroin biomaterial in the repair of articular cartilage defects.

Cartilage tissue engineering requires a porous biodegradable scaffold and nonimmunogenic cells with chondrogenic potential. In this study, the ability of the placenta-derived mesenchymal stem cells (PMSCs) to grow on silk fibroin (SF) biomaterial was determined, and the potential of a SF biomaterial serving as a delivery vehicle for human PMSCs in a rabbit articular cartilage defects model was evaluated. Human PMSCs were maintained in vitro in an allogeneic mixed lymphocyte reactions (MLR) system to investigate the suppressive effects on T cell proliferation. A total of 12 healthy adult New Zealand rabbits were implanted with a PMSC/SF biomaterial complex after articular cartilage defects of the femoral condyle in the knee were established. The repair of the articular cartilage defects was observed after 4 weeks, 8 weeks, and 12 weeks. Results from the MLR indicated that human PMSCs inhibited rabbit T cell responses. Knee damage was repaired by the newly formed hyaline cartilage, and within 12 weeks there was neither degeneration nor infiltration with lymphocytes or leukocytes, and no silk fibroin biomaterial residue was detected. In conclusion, the silk fibroin biomaterial can be applied as a new scaffold for cartilage tissue engineering, and implantation of human PMSCs on the cartilage can enhance repair of articular cartilage defects in a rabbit model.

Clinical outcomes of downregulation of E-cadherin gene expression in non-small cell lung cancer.

OBJECTIVE: To investigate the promoter methylation status of the E-cadherin gene in non-small cell lung cancer (NSCLC) and its association with clinical pathological parameters, and to explore the relationship between downregulation of E-cadherin gene expression and the methylation status of its promoter region. METHODS: Nested methylation-specific PCR was performed to examine CpG methylation within the 5' CpG island of the E-cadherin gene in lung cancer and para-cancerous tissue from 37 patients with primary non-small cell lung cancer. Quantitative real-time PCR was performed to measure the level of E-cadherin mRNA. RESULTS: Of thirty-seven cases, 12 (32.4%) samples showed aberrant CpG methylation in tumor tissues compared with the corresponding normal tissues. In addition, a reduction in E-cadherin mRNA levels was observed in 11 of the 12 (91.7%) tumor tissues carrying a methylated E-cadherin gene. However, only 10 (43.5%) cases displayed reduced mRNA levels in tumor tissues from the remaining 23 cases (excluding 2 samples from which mRNA was unavailable) without methylation events. Downregulation of E-cadherin gene expression significantly correlated with the promoter methylation status of this gene. CONCLUSION: These results provide strong evidence that the methylation status of E-cadherin gene contributes to a reduction in the expression of E-cadherin mRNA, and may play a role in the development and progression of NSCLC.

Clinical application of the adenosine triphosphate-based response assay in intravesical chemotherapy for superficial bladder cancer.

OBJECTIVE: To investigate correlations between adenosine triphosphate chemotherapy response assay (ATP-CRA) and clinical outcomes after ATP-CRA-based chemotherapy for drug selection in patients receiving intravesical chemotherapy to prevent recurrence of superficial bladder cancer after surgery. METHODS: The chemosensitivities of 12 anticancer drugs were evaluated, including 5-Fu ADM, and EPI, using ATP-CRA and primary tumor cell culture in 54 patients. In addition, a further 58 patients were treated according to clinical experience. Differences in post-chemotherapeutical effects between drug sensitivity assay and experience groups were compared. RESULTS: The evaluable rate of the test was 96.3%, the clinical effective rate was 80.8%, the sensitivity rate was 97.6% (41/42), the specificity was 20%, the total predicting accuracy was 74.3%, the positive predictive value was 83.7% (41/49), the negative predictive value was 66.7% (2/3); in the drug sensitivity test group, the clinical effective rate was 80.8%, the experience group response rate was 63.8%, with a significant difference in clinical effects between the ATP-based sensitivity and experience groups (χ2 =7.0153, P<0.01). CONCLUSION: ATP-CRA is a stable, accurate and potentially practical chemosensitivity test providing a predictor of chemotherapeutic response in patients with superficial bladder cancer.

Clinical significance of expression and amplification of the DcR3 gene in pancreatic carcinomas.

This study aimed to investigate the clinical significance of expression and amplification of decoy receptor 3 (DcR3) in pancreatic carcinomas (PC). mRNA expression was detected by PQ-PCR, and amplification was determined. DcR3 protein expression was detected by immunohistochemistry and ELISA. Correlations between DcR3 expression and clinical pathological factors were analyzed. The relative amount of DcR3 in PC tissues and non-cancerous tissues showed a statistically significant difference, 21 cases displaying more than two fold DcR3 amplification, while no such amplification was found in normal pancreatic tissues. DcR3 positive cell staining was located in the cytoplasm. The positive rate of DcR3 in PC and non-cancerous tissues showed a significant difference. DcR3 mRNA expression was correlated with clinical staging, size of the tumor, lymph node metastasis and histological staging, while protein expression was correlated with clinical data like tumor size. DcR3 gene amplification only correlated with tumor size. The level of DcR3 in serum of the PC resectable group before operation was 72.2±10.2 pg/ml, showing a significant difference compared to gallbladder carcinoma group (GC) or pancreatic benign tumor (PBT) group (P <0.01). In conclusion, DcR3 amplification is correlated with DcR3 expression in PC tissues, especially those clinical pathological factors which reflect tumor progression. Assessment of DcR3 level in sera of PC patients may be helpful for the early diagnosis and prognostic judgement.

Anticancer effect and apoptosis induction by quercetin in the human lung cancer cell line A-549.

The aim of the present study was to investigate the anticancer effect of quercetin (QC) in the human lung cancer cell line A-549 and further study the mechanism of apoptosis induction by QC. Low differentiation potential A-549 human lung cancer cells were treated with QC at different doses and for different times, and the growth inhibitory rates were detected by MTT assay. Apoptosis induced by QC in A-549 cells was observed by Annexin V/PI double staining and flow cytometric assay. The relative tumor growth ratio of the treated/control tumors (T/C) (%) was chosen to represent the tumor growth inhibition of A-549 cell nude mouse xenografts by QC. Apoptosis of the nude mouse xenografts was observed by Annexin V/PI double staining and flow cytometric assay and DNA fragmentation assay. To further determine the molecular mechanism of apoptosis induced by QC, changes in the expression of bcl-2 and bax genes were detected by RT-PCR. Following incubation with QC, the cell growth of the low differentiation potential A-549 human lung cancer cells was dramatically inhibited in a dose-dependent manner. After the cells were exposed to QC for 24, 48 and 72 h, the IC50 value was 1.02 ± 0.05, 1.41 ± 0.20 and 1.14 ± 0.19 µmol/l, respectively. Apoptosis in the A-549 cells induced by QC was noted. The apoptotic subpopulation of A-549 cells was approximately 12.96 and 24.58%, respectively, when cells were incubated with 1.2 µmol/l QC for 48 and 72 h. T/C (%) of A-549 nude mouse xenografts was 44.3, when the nude mice were treated with QC (8 mg/kg). Meanwhile, apoptosis induced by QC was observed in the A-549 nude mouse xenografts. Increased expression of the bax gene and decreased expression of the bc1-2 gene were noted using RT-PCR. Our results provide further evidence of the growth inhibition of the A-549 human lung adenocarcinoma cancer cell line by QC. This effect is associated with the induction of apoptosis in A-549 cells and the molecular mechanism may be related to the reduction in expression of the apoptosis-regulating gene bcl-2, and increase in expression of the apoptosis-regulating gene bax. These results were also confirmed in vivo.

No association between TGFBR1*6A and lung cancer.

INTRODUCTION: TGFBR1*6A, a functionally polymorphic allele in the transforming growth factor [beta] receptor 1 gene (TGFBR1), has been hypothesized to increase risk of various cancers. However, little has been documented about connection of this variant with lung cancer. METHODS: In an attempt to explore whether the TGFBR1*6A is associated with lung cancer, we performed genotyping followed by sequencing in 252 patients with lung cancer and 250 healthy controls. RESULTS: The frequency for the heterozygote 9A/6A is 13.9% in cases compared with 12.4% in controls, and the odds ratio is 1.14 (95% confidence interval: 0.68-1.91), which is not statistically significant (p = 0.62), suggesting that TGFBR1*6A could not be a cancer susceptibility factor for Chinese patients with lung cancer. CONCLUSIONS: We have no evidence to support the hypothesis that TGFBR1*6A is associated with lung cancer.

Adenovirus-mediated FasL gene transfer into human gastric carcinoma.

AIM: To evaluate the possible value of FasL in gastric cancer gene therapy by investigating the effects of FasL expression on human gastric cancer cell line. METHODS: An adenoviral vector encoding the full-length human FasL cDNA was constructed and used to infect a human gastric cancer (SGC-7901) cell line. FasL expression was confirmed by X-gal staining, flow cytometric analysis and RT-PCR. The effect of FasL on cell proliferation was determined by clonogenic assay, cytotoxicity was detected by MTT assay, and cell viability was measured by trypan blue exclusion. The therapeutic efficiency of Ad-FasL in vivo was investigated with a xenograft tumor model in nude mice. RESULTS: SGC-7901 cells infected with Ad-FasL showed increased expression of FasL, resulting in significantly decreased cell growth and colony-forming activity when compared with control adenovirus-infected cells. The cytotoxicity of anti-Fas antibody (CH-11) in gastric cancer cells was stronger than that of ActD (91+/-8 vs 60+/-5, P<0.01), and the cytotoxicity of Ad-FasL was stronger than that of CH-11 (60+/-5 vs 50+/-2, P<0.05). In addition, G1-phase arrest (67.75+/-0.39 vs 58.03+/-2.16, P<0.05) and apoptosis were observed in Ad-FasL-infected SGC-7901 cells, and the growth of SGC-7901 xenografts in nude mice was retarded after intra-tumoral injection with Ad-FasL (54% vs 0%, P<0.0001). CONCLUSION: Infection of human gastric carcinoma cells with Ad-FasL induces apoptosis, indicating that this target gene might be of potential value in gene therapy for gastric cancer.

Anti-gastric cancer active immunity induced by FasL/B7-1 gene-modified tumor cells.

AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tumor cells could initiate synergistic antitumor effect. METHODS: FasL and B7-1 genes were transfected into human SGC-7901 gastric cancer cells with adenovirus vectors. The positive clones were selected by G418. FasL and B7-1 genes were detected by flow cytometry and RT-PCR. Abdominal infiltrating lymphocytes and sensitized spleen cells were obtained from mice that were immunized with SGC-7901/FB-11 or wild type SGC-7901 cells intraperitoneally, and cytotoxicity of these CTLs against tumor cells was determined by MTT assay. RESULTS: Flow cytometry and RT-PCR showed that FasL and B7-1 genes were highly expressed. FasL and B7-1 transfected cancer cells had a high apoptosis index. DNA laddering suggested that FasL and B7-1 genes induced gastric cancer cell apoptosis. FasL(+)/B7-1(+)SGC-7901 cells (SGC-7901/FB-11) were inoculated subcutaneously in the dorsal skin of C57BL/6 mice and then decreased their tumorigenicity greatly (z = 2.15-46.10, P<0.01). SGC-7901/FB-11 cell-sensitized mice obtained protective immune activity against the rechallenge of wild type SGC-7901 cells (z = 2.06-44.30, P<0.05). The cytotoxicity of CTLs induced by SGC-7901/FB-11 cells against SGC-7901 was significantly higher than that of CTLs activated by wild-type SGC-7901 cells (84.1+/-2.4% vs 30.5+/-2.3%, P<0.05). CONCLUSION: FasL and B7-1 genes can effectively promote the activity of CTLs against gastric cancer cells. FasL/B7-1 molecules play an important role in CTL cytotoxicity.