S-ketamine Infusion on Chronic Postoperative Pain Following Breast Cancer Surgery: A Randomized Double-Blind Placebo-Controlled Trial.

BACKGROUND: Chronic postoperative surgical pain (CPSP) is a frequent complication following breast surgery and poses a challenge in terms of treatment. We hypothesized that the incidence of CPSP would be reduced at 3 months post-breast surgery with the administration of S-ketamine compared to a placebo. PATIENTS AND METHODS: Participants were recruited and randomly assigned to either the S-ketamine group (S) or the control group (C). In group S, S-ketamine was administered as a 1.5 mg kg-1 bolus followed by 2 mg kg-1h-1 infusion, while in group C, a placebo of 0.9% saline was administered in the same volume and rate as S-ketamine. The primary outcome was the incidence of CPSP, measured using a 0-10 numeric rating scale (NRS), at 3 months postsurgery. RESULTS: A total of 72 patients scheduled for mastectomy were enrolled (group S, n = 33; group C, n = 32). The incidence of CPSP at 3 months postsurgery was significantly lower in group S compared to group C (18.2% vs. 48.3%, P < .05). There was no statistical difference between the 2 groups in terms of the incidence of moderate to severe pain. NRS scores for postoperative pain at rest and during movement were significantly lower at 4 h and 24 h post-surgery (P < .05, respectively). Patients in Group S had lower Patient Health Questionnaire-9 (PHQ-9) scores at one week and 3 months post-surgery compared to Group C (P < .05, respectively). CONCLUSION: S-ketamine infusion reduces the incidence of CPSP 3 months after breast surgery.

Association Between Preoperative Sleep Disturbance and Postoperative Delirium in Elderly: A Retrospective Cohort Study.

Purpose: Postoperative sleep disturbance, characterized by diminished postoperative sleep quality, is a risk factor for postoperative delirium (POD); however, the association between pre-existing sleep disturbance and POD remains unclear. This study aimed to evaluate the association between preoperative sleep disturbance and POD in elderly patients after non-cardiac surgery. Patients and methods: This retrospective cohort study was conducted at a single center and enrolled 489 elderly patients who underwent surgery between May 1, 2020, and March 31, 2021. Patients were divided into the sleep disorder (SD) and non-sleep disorder (NSD) groups according to the occurrence of one or more symptoms of insomnia within one month or sleep- Numerical Rating Scale (NRS)≥6 before surgery. The primary outcome was the incidence of POD. Propensity score matching analysis was performed between the two groups. Multiple logistic regression analysis was performed to identify the risk factors for POD. Results: In both the unmatched cohort (16.0% vs 6.7%, P=0.003) and the matched cohort (17.0% vs 6.2%, P=0.023), the incidence of POD was higher in the SD group than in the NSD group. In addition, the postoperative sleep quality and the VAS score at postoperative 24 h were significantly lower in the SD group than in the NSD group. Multivariate logistic regression analysis indicated that age (Odds Ratio, 1.13 [95% CI: 1.04-1.23], P=0.003) and preoperative sleep disturbance (Odds Ratio, 3.03 [95% CI: 1.09-9.52], P=0.034) were independent risk factors for the development of POD. Conclusion: The incidence of POD was higher in patients with pre-existing sleep disturbance than those without it. Whether improving sleep quality for preoperative sleep disturbance may help prevent POD remains to be determined.

Myocardial protective effects of dexmedetomidine in patients undergoing cardiac surgery: A meta-analysis and systematic review.

Arrhythmias are the common complications following cardiac surgery and contribute to hemodynamic instability, cognitive impairment, thromboembolic events, and congestive heart failure. Prevention of atrial fibrillation following cardiac surgery reduces morbidity and among the many available preventive approaches dexmedetomidine shows many positive effects on cardiovascular stability. Even though many studies indicated the beneficial effects of dexmedetomidine, the power of the analysis and conclusion of these studies is rather weak due to relatively smaller number of patients in these studies. In the present meta-analysis, we included a large number of patients, both children and adults, undergoing cardiac surgery, to address the efficacy of dexmedetomidine. Several databases were searched to identify clinical studies comparing the efficacy of dexmedetomidine in myocardial protection in patients undergoing cardiac surgery. Cardiac function related parameters including heart rate, blood pressure, tachycardia, arrhthmias, and bradycardia were measured. In accordance with the selection criteria, a total of 18 studies published between 2003 and 2016, with a total of 19,225 patients were included in the present meta-analysis. Dosage of dexmedetomidine was in the range of 0.5-1 µg/kg body weight loading followed by continuous infusion at a rate of 0.2-0.7 µg/kg/h. Dexmedetomidine treatment was found to lower heart rate, systolic blood pressure, incidence of tachycardia and arrhythmias in both adult and pediatric patients, but elevated the risk of bradycardia. In conclusion, results of this meta-analysis indicate that dexmedetomidine is an efficacious cardioprotective drug in adults and children undergoing cardiac surgery.

E2F-1 overexpression inhibits human gastric cancer MGC-803 cell growth in vivo.

AIM: To evaluate the influence of E2F-1 on the growth of human gastric cancer (GC) cells in vivo and the mechanism involved. METHODS: E2F-1 recombinant lentiviral vectors were injected into xenograft tumors of MGC-803 cells in nude mice, and then tumor growth was investigated. Overexpression of transcription factor E2F-1 was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting analysis. Apoptosis rates were determined using a terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Expression levels of certain cell cycle regulators and apoptosis-related proteins, such as Bax, survivin, Bcl-2, cyclin D1, S-phase kinase-associated protein 2, and c-Myc were examined by Western blotting and RT-PCR. RESULTS: Xenograft tumors of MGC-803 cells in nude mice injected with E2F-1 recombinant lentiviral vectors stably overexpressed the E2F-1 gene as measured by semi-quantitative RT-PCR (relative mRNA expression: 0.10 ± 0.02 vs 0.05 ± 0.02 for control vector and 0.06 ± 0.03 for no infection; both P < 0.01) and Western blotting (relative protein expression: 1.90 ± 0.05 vs 1.10 ± 0.03 in control vector infected and 1.11 ± 0.02 for no infection; both P < 0.01). The growth-curve of tumor volumes revealed that infection with E2F-1 recombinant lentiviral vectors significantly inhibited the growth of human GC xenografts (2.81 ± 1.02 vs 6.18 ± 1.15 in control vector infected and 5.87 ± 1.23 with no infection; both P < 0.05) at 15 d after treatment. TUNEL analysis demonstrated that E2F-1 overexpression promoted tumor cell apoptosis (18.6% ± 2.3% vs 6.7% ± 1.2% in control vector infected 6.3% ± 1.2% for no infection; both P < 0.05). Furthermore, lentiviral vector-mediated E2F-1 overexpression increased the expression of Bax and suppressed survivin, Bcl-2, cyclin D1, Skp2, and c-Myc expression in tumor tissue. CONCLUSION: E2F-1 inhibits growth of GC cells via regulating multiple signaling pathways, and may play an important role in targeted therapy for GC.

Overexpression of CDX2 in gastric cancer cells promotes the development of multidrug resistance.

Modulator of multidrug resistance (MDR) gene is a direct transcriptional target of CDX2. However, we still speculate whether CDX2 affects MDR through other ways. In this study, a cisplatin-resistant (SGC7901/DDP) and a 5-fluoro-2, 4(1h,3h)pyrimidinedione-resistant (BGC823/5-FU) gastric cancer cell line with stable overexpression of CDX2 were established. The influence of overexpression of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP and BGC823/5-FU cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2-overexpression lentiviral vector (LV-CDX2-GFP) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. Results showed that LV-CDX2-GFP led to up-regulation of CDX2 mRNA and protein expression. It significantly inhibited the sensitivity of SGC7901/DDP and BGC823/5-FU cells to cisplatin, doxorubicin, and 5-fluorouracil. Flow cytometry confirmed that the percentage of apoptotic cells decreased after CDX2 up-regulation. This notion was further supported by the observation that up-regulation of CDX2 blocked entry into the M-phase of the cell cycle. Furthermore, up-regulation of CDX2 significantly decreased intracellular accumulation of doxorubicin. In molecular studies, quantitative reverse-transcriptase real-time polymerase chain reaction and western blotting revealed that CDX2 up-regulation could suppress expression of Caspase-3, Caspase-9 and PTEN, and increased the expression of MDR1, MRP, mTOR, HIF-1α.

Overexpression of E2F1 in human gastric carcinoma is involved in anti-cancer drug resistance.

BACKGROUND: Routine chemotherapy often cannot achieve good therapeutic effects because of multidrug resistance (MDR). MDR is frequently caused by the elevated expression of the MDR1 gene encoding P-glycoprotein (P-gp). E2F1 is a frequently overexpressed protein in human tumor cells that increases the activity of the MDR1 promoter, resulting in higher P-gp levels. The upregulation of P-gp might contribute to the survival of tumor cells during chemotherapy. E2F1 confers anticancer drug resistance; however, we speculate whether E2F1 affects MDR through other pathways. This study investigated the possible involvement of E2F1 in anticancer drug resistance of gastric carcinoma in vitro and in vivo. METHODS: A cisplatin-resistant SGC7901/DDP gastric cancer cell line with stable overexpression of E2F1 was established. Protein expression levels of E2F1, MDR1, MRP, TAp73, GAX, ZEB1, and ZEB2 were detected by western blotting. The influence of overexpression of E2F1 on anticancer drug resistance was assessed by measuring IC50 of SGC7901/DDP cells to cisplatin, doxorubicin, and 5-fluorouracil, as well as the rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. We determined the in vivo effects of E2F1-overexpression on tumor size in nude mice, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. RESULTS: The SGC7901/DDP gastric cancer cell line stably overexpressing E2F1 exhibited significantly inhibited sensitivity to cisplatin, doxorubicin, and 5-fluorouracil. Flow cytometry confirmed that the percentage of apoptotic cells decreased after E2F1 upregulation, and that upregulation of E2F1 potentiated S phase arrest of the cell cycle. Furthermore, upregulation of E2F1 significantly decreased intracellular accumulation of doxorubicin. Western blot revealed that E2F1 upregulation suppressed expression of GAX, and increased the expression of MDR1, MRP, ZEB1, TAp73, and ZEB2. CONCLUSIONS: Overexpression of E2F1 promotes the development of MDR in gastric carcinoma, suggesting that E2F1 may represent an efficacious target for gastric cancer therapy.

New insights into the functions and localization of the homeotic gene CDX2 in gastric cancer.

Gastric cancer is one of the most frequent cancers, and it ranks the third most common cancer in China. The most recently caudal-related homeobox transcription factor 2 (CDX2) is expressed in a large number of human gastrointestinal cancers. In addition, gastric epithelial cell mutations in CDX2 result in tumor promotion, which is characterized by cellular drug resistance and a high proclivity for developing cancer. A series of publications over the past years suggests a mechanism by which CDX2 overexpression results in multidrug resistance. CDX2 appears to forward control regenerating IV and the multidrug resistance 1 expression signaling pathway for regulation of cell drug resistance.

Reversal of multidrug resistance in gastric cancer cells by E2F-1 downregulation in vitro and in vivo.

UNLABELLED: Transcription Factor E2F-1 plays a critical role in cell cycle regulation and other biological processes in cells. However whether or not it is involved in the multi-drug resistance (MDR) process of gastric cancer has not been fully elucidated yet. To explore the role of E2F-1 in the MDR process of gastric cancer in vitro and in vivo, a cisplatin-resistant gastric cancer cell line with stable downregulation of E2F-1 was established. E2F-1 shRNA led to downregulation of endogenous E2F-1 mRNA and protein. It significantly promoted the sensitivity of SGC7901/DDP cells to cisplatin, doxorubicin, and fluorouracil. Flow cytometry confirmed that the percentage of apoptotic cells increased after E2F-1 downregulation. This notion was further supported by the observation that downregulation of E2F-1 blocked entry into the S-phase of the cell cycle. Furthermore, downregulation of E2F-1 significantly increased intracellular accumulation of doxorubicin. In addition, we determined the in vivo effects of E2F-1 small interfering RNA (shRNA) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. In molecular studies, semiquantitative RT-PCR and western blotting revealed that E2F-1 downregulation could inhibit expression of MDR1, MRP, Bcl-2/Bax, c-Myc, Skp2, Survivin, and Cyclin D1. IN CONCLUSION: E2F-1 may be involved in regulating multiple signaling pathways in reversing MDR, suggesting that E2F-1 may represent a novel target for gastric cancer therapy.

[Inhibitory effect of E2F-1-silencing lentivirus vector on chemoresistance of subcutaneous human gastric cancer in nude mice].

OBJECTIVE: To study the effects of E2F-1-silencing lentivirus vector on the growth and chemoresistance of subcutaneous human gastric cancer in nude mice. METHODS: Thirty-six nude mice were inoculated subcutaneously with chemoresistant SGC-7901/DDP cells to establish subcutaneous tumor models of gastric carcinoma. The mice were randomly divided into E2F-1/RNAi-LV group, LV-scrRNAi group and PBS group (n = 12). E2F-1/RNAi-LV, LV-scrRNAi or PBS (0.1 ml per time) was injected into the mice, respectively, every two days. The nude mice received an intraperitoneal injection of cisplatin (25 mg/kg) every two days. The tumor volume was measured and histopathological changes of the tumors were observed by HE staining. The expressions of E2F-1, c-Myc, survivin, MDR1 and MRP were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Apoptosis in tumor xenografts was determined by in situ TUNEL labeling technique. RESULTS: The mean tumor growth rate of the E2F-1/RNAi-LV group was significantly slower than that of the LV-scrRNAi and control groups (P < 0.05). The tumor volume of the E2F-1/RNAi-LV group was (745.13 ± 154.42)mm(3), significantly lower than that of the LV-scrRNAi and PBS groups (P < 0.05). Compared with that in the LV-scrRNAi and PBS groups, the expressions of mRNA and protein of E2F-1, c-Myc, survivin, MDR1 and MRP were significantly decreased in the E2F-1/RNAi-LV group (P < 0.05). The apoptotic rate in the E2F-1/RNAi-LV treatment group was (27.5 ± 9.7)%, significantly higher than (7.0 ± 1.1)% in the LV-scrRNAi group and (7.3 ± 1.2)% in the PBS group (P < 0.05). CONCLUSION: Intra-tumoral injection of E2F-1/RNAi-LV shows significantly inhibitory effect on the tumor growth and chemoresistance of subcutaneous human gastric cancer in nude mice.

Reversal of multidrug resistance in gastric cancer cells by CDX2 downregulation.

AIM: To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo. METHODS: A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was established. mRNA and protein expression levels of CDX2, survivin, cyclin D1, and c-Myc were detected by western blotting and semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The influence of downregulation of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2 small interfering RNA (siRNA) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. RESULTS: CDX2 siRNA led to downregulation of endogenous CDX2 mRNA (0.31 ± 0.05 vs 1.10 ± 0.51, 0.31 ± 0.05 vs 1.05 ± 0.21, P = 0.003) and protein (0.12 ± 0.08 vs 0.51 ± 0.07, 0.12 ± 0.08 vs 0.55 ± 0.16, P = 2.57 × 10(-4)) expression. It significantly promoted the sensitivity of SGC7901/DDP cells to cisplatin (0.12 ± 0.05 vs 0.33 ± 0.08, 0.12 ± 0.05 vs 0.39 ± 0.15, P = 0.001), doxorubicin (0.52 ± 0.13 vs 4.11 ± 1.25, 0.52 ± 0.13 vs 4.05 ± 1.44, P = 2.81 × 10(-4)), and 5-fluorouracil (0.82 ± 0.13 vs 2.81 ± 0.51, 0.82 ± 0.13 vs 3.28 ± 1.03, P = 1.71 × 10(-4)). Flow cytometry confirmed that the percentage of apoptotic cells increased after CDX2 downregulation (32.15% ± 2.15% vs 17.63% ± 3.16%, 32.15% ± 2.15% vs 19.3% ± 2.25%, P = 1.73 × 10(-6)). This notion was further supported by the observation that downregulation of CDX2 blocked entry into the S-phase of the cell cycle (31.53% ± 3.78% vs 65.05% ± 7.25%, 31.53% ± 3.78% vs 62.27% ± 5.02%, P = 7.55 × 10(-7)). Furthermore, downregulation of CDX2 significantly increased intracellular accumulation of doxorubicin (0.21 ± 0.06 vs 0.41 ± 0.11, 0.21 ± 0.06 vs 0.40 ± 0.08, P = 0.003). In molecular studies, semiquantitative RT-PCR and western blotting revealed that CDX2 downregulation could inhibit expression of c-Myc, survivin and cyclin D1. CONCLUSION: CDX2 may be involved in regulating multiple signaling pathways in reversing MDR, suggesting that CDX2 may represent a novel target for gastric cancer therapy.

Prognostic significance of Cdx2 immunohistochemical expression in gastric cancer: a meta-analysis of published literatures.

Cdx2 is a homeobox domain-containing transcription factor that is important in the development and differentiation of the intestinal cells, and served as a potential biomarker of tumor progression in early intestinal-type gastric cancer. However, its prognostic value and significance in gastric cancer remain controversial. A meta-analysis based on published studies was performed to obtain an accurate evaluation of the association between the presence of Cdx2-positive in clinical samples and clinical outcome. A total of 13 eligible retrospective cohort studies with 1513 patients were included. Cdx2-positive cases were significantly associated with higher male-to-female ratio (RR=1.27, 95% CI: 1.17-1.38, P<0.00001 fixed-effect), lower (I+II) clinical stage (RR=1.63, 95% CI: 1.42-1.87, P<0.00001 fixed-effect), better histologic differentiation (RR=1.54, 95% CI: 1.34-1.76, P<0.00001 fixed-effect), and lower rate of vascular invasion (RR=1.23, 95% CI: 1.08-1.41, P=0.002 fixed-effect) and lymph node metastasis (RR=1.52, 95% CI: 1.33-1.73, P<0.00001 fixed-effect), as well as higher 5-year survival rate (HR=2.22, 95% CI: 1.78-2.75, P<0.00001 fixed-effect). However, the presence of Cdx2 was not associated with tumor size. In summary, Cdx2 is a prognostic factor in gastric cancer, which acts as a marker of good outcome in patients with gastric cancer. Further clinical studies are needed to confirm the role of Cdx2 in clinical practice.

Exogenous morphine inhibits human gastric cancer MGC- 803 cell growth by cell cycle arrest and apoptosis induction.

Morphine is not only an analgesic treating pain for patients with cancer but also a potential anticancer drug inhibiting tumor growth and proliferation. To gain better insight into the involvement of morphine in the biological characteristics of gastric cancer, we investigated effects on progression of gastric carcinoma cells and the expression of some apoptosis-related genes including caspase-9, caspase-3, survivin and NF-κB using the MGC-803 human gastric cancer cell line. The viability of cells was assessed by MTT assay, proliferation by colony formation assay, cell cycle progression and apoptosis by flow cytometry and ultrastructural alteration by transmission electron microscopy. The influences of morphine on caspase-9, caspase-3, survivin and NF-κB were evaluated by semi-quantitative RT-PCR and Western blot. Our data showed that morphine could significantly inhibit cell growth and proliferation and cause cell cycle arrest in the G2/M phase. MGC-803 cells which were incubated with morphine also had a higher apoptotic rate than control cells. Morphine also led to morphological changes of gastric cancer cells. The mechanism of morphine inhibiting gastric cancer progression in vitro might be associated with activation of caspase-9 and caspase-3 and inhibition of survivin and NF-κB.

siRNA targeting of Cdx2 inhibits growth of human gastric cancer MGC-803 cells.

AIM: To investigate the effects of small interference RNA (siRNA) targeting of Cdx2 on human gastric cancer MGC-803 cells in vitro and in vivo. METHODS: The recombinant pSilencer 4.1-Cdx2 siRNA plasmids were constructed and transfected into gastric cancer MGC-803 cells in vitro. The stable transfectants were selected. The effects of Cdx2 siRNA on growth, proliferation, cell cycle, apoptosis, migration and invasiveness of human gastric cancer MGC-803 cells were evaluated and the expression of phosphatase and tensin homolog (PTEN), caspase-9 and caspase-3 was observed in vitro by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting analysis. We also investigated the effect of Cdx2 siRNA on growth of MGC-803 cells in nude mice in vivo. RESULTS: Cdx2 siRNA led to inhibition of endogenous Cdx2 mRNA and protein expression as determined by RT-PCR and Western blotting analysis. Cdx2 siRNA significantly inhibited cell growth and proliferation, blocked entry into the S-phase of the cell cycle, induced cell apoptosis, and reduced the motility and invasion of MGC-803 cells. Cdx2 siRNA also increased PTEN expression, and activated caspase-9 and caspase-3 in MGC-803 cells in vitro . In addition, siRNA targeting of Cdx2 inhibited the growth of MGC-803 cells and promoted tumor cell apoptosis in vivo in nude mice tumor models. CONCLUSION: Cdx2 was involved in regulating pro-gression of human gastric cancer cells MGC-803. Manipulation of Cdx2 expression may be a potential therapeutic strategy for gastric cancer.

Lentivirus-mediated RNA interference targeting E2F-1 inhibits human gastric cancer MGC-803 cell growth in vivo.

The E2F-1 transcription factor is post-translationally modified and stabilized in response to various forms of DNA damage to regulate the expression of cell-cycle and pro-apoptotic genes. The sustained overexpression of E2F-1 is a characteristic feature of gastric cancer. In this study, we investigated the role of short hairpin RNA (shRNA) targeting E2F-1 gene on human gastric cancer MGC-803 cell growth in vivo, and preliminarily revealed the mechanism. Thus, we constructed recombinant pGCSIL-GFP-shRNA-E2F-1 lentiviral vector to knock down E2F-1 expression in human gastric cancer MGC-803 cells in vivo, and studied the effect of E2F-1 shRNA on growth of MGC-803 tumor and evaluated its treatment efficacy. Our data demonstrated that in a mouse model of established gastric cancer, intratumor injection of lentiviral shRNA targeting E2F-1 definitely decreased the endogenous E2F-1 mRNA and protein expression in MGC-803 tumor, and inhibited tumor growth and promoted tumor cells apoptosis. Moreover, we found that E2F-1 shRNA increased the expression of phosphatase and tensin homolog (PTEN), activated caspase-3 and caspase-9, and suppressed nuclear factor (NF)-κB expression in tumor tissue as determined by reverse transcription (RT)-PCR and western blotting. In summary, shRNA targeting of E2F-1 can effectively inhibits human gastric cancer MGC-803 cell growth in vivo and may be a potential therapeutic strategy for gastric cancer.

[Effects of E2F-1 overexpression on apoptosis of gastric cancer cells and expressions of apoptosis-related genes].

BACKGROUND AND OBJECTIVE: E2F transcription factor 1 (E2F-1) is an important transcription factor in cell cycle. This study was to investigate the effects of E2F-1 overexpression on apoptosis of gastric cancer MGC-803 cells and expressions of the downstream genes. METHODS: The apoptotic rates were measured by flow cytometry in MGC-803/E2F-1 cells, MGC-803/EV cells or untransfected MGC-803 cells. The total RNA was extracted from MGC-803/E2F-1 cells or MGC-803 cells, and cDNA was obtained by RT-PCR. Fluorescent (fluorescence exchange clip) probes marked by Cy5 and Cy3 were hybridized with gene chips containing 21522 human genes. Subsequently, the two signal images were scanned by Lux Scan 10K/A dual pathways laser scanner and analyzed by LuxScan3.0 image analysis software. RT-PCR was used to verify the target genes. RESULTS: The apoptotic rate of MGC-803/E2F-1 cells [(8.40+/-0.91)%] was higher than that of MGC-803/EV [(4.53+/-0.61)%] and MGC-803 cells [(4.97+/-0.47)%]. Fifteen differentially expressed apoptosis-related genes were detected, 4 of which were up-expressed and 11 were down-expressed genes, and the same results were verified by RT-PCR. CONCLUSION: Overexpression of E2F-1 accelerates apoptosis of gastric carcinoma MGC-803 cells, which may be related to the 15 differentially expressed genes.

[Caudal-related homeobox 2 gene expression and its effects on human gastric carcinoma cell line].

OBJECTIVE: To investigate the effect of human caudal-related homeobox 2 (Cdx2) gene expression on human gastric carcinoma cell line MGC-803. METHODS: pCMV-Cdx2-HA eukaryotic expression plasmid was constructed by using DNA recombinant method. The MGC-803 cells were divided into 4 groups: non-transfected, transfected with pCMV-HA, transfected with pCMV-GAPDH-HA, transfected with pCMV-Cdx2-HA. Cdx2 gene and its protein expression was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot techniques respectively. The effects of Cdx2 overexpression on the growth of MGC-803 cells in vitro was assessed by measuring MTT, flow cytometry and transmission electron microscopy analysis. RESULTS: In MGC-803 cells transfected with pCMV-Cdx2-HA, cell proliferation was significantly suppressed, the cells was ultrastructurally destroyed, cell cycle progression was blocked in G0/G1 and apoptosis rate was higher (P<0.05) in comparison with non-transfected cells or cells transfected with empty vector. CONCLUSION: It indicated that Cdx2 gene can suppress the growth of gastric carcinoma and may save as a novel therapeutic target.

[Inhibitory effects of transcription factor E2F-1 siRNA on invasion and proliferation of gastric cancer cell line MGC803].

BACKGROUND & OBJECTIVE: As an important regulatory factor of cell cycle, transcription factor E2F-1 is closely related to tumorigenesis. This study was to investigate the effects of E2F-1 small interfering RNA (siRNA) on invasion and proliferation of human gastric cancer MGC803 cells. METHODS: E2F-1 siRNA vector containing short hairpin structure was transfected into MGC803 cells. Untransfected and pSilencer4.1-negative-transfected cells were used as controls. The expression of E2F-1 was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Cell matrigel invasion assay and cloning assay were used to detect the invasion and proliferation of MGC803 cells after E2F-1 siRNA transfection. RESULTS: At 48 h after E2F-1 siRNA transfection, the mRNA level of E2F-1 was down-regulated by over 90.0% of controls; the protein level of E2F-1 was down-regulated by 79.6% of negative control and by 81.5% of empty control. The number of migrated cells was significantly smaller in E2F-1 siRNA group than in negative and empty control groups (18.0+/-2.6 vs. 48.0+/-4.6 and 54.0+/-5.6, P<0.05). The number of cell clones was also significantly smaller in E2F-1 siRNA group than in negative and empty control groups (46.0+/-2.0 vs. 122.3+/-1.5 and 128.7+/-2.1, P<0.05) CONCLUSION: E2F-1 siRNA could down-regulate E2F-1 expression in human gastric cancer MGC803 cells and suppress its invasion and proliferation to some extent.

[Construction of a eukaryotic vector expressing E2F-1 Gene and its effect on proliferation of gastric cancer cell line MKN-45].

BACKGROUND & OBJECTIVE: E2F-1 is overexpressed in many tumors and functions as an oncogene or tumor suppressor gene. This study was to construct the recombinant eukaryotic vector expressing E2F-1 cDNA, and explore the effect of E2F-1 overexpression on the proliferation of human gastric carcinoma cell line MKN-45. METHODS: The fragment of E2F-1 gene was amplified by polymerase chain reaction (PCR). A eukaryotic vector expressing E2F-1 (pCMV-E2F1-HA) was constructed with pCMV-HA, and transfected into COS-7 cells to identify whether E2F-1 was successfully subcloned into the eukaryotic vector. pCMV-E2F1-HA was transfected into MKN-45 cells. The expression of E2F-1 in MKN-45 cells was detected by Western blot. The proliferation of MKN-45 cells was observed by colony formation assay and MTS method. Cell cycle was analyzed by flow cytometry (FCM). RESULTS: Recombinant plasmid pCMV-E2F1-HA was successfully constructed and transfected into COS-7 and MKN-45 cells. MKN-45 cell clones were significantly fewer in pCMV-E2F1-HA group than in pCMV-HA group (4.7+/-1.8 vs. 30.2+/-6.7, P<0.01). The proliferation rate of MKN-45 cells was significantly lower in pCMV-E2F1-HA group (73.5% on Day 5, 63.5% on Day 6, 56.1% on Day 7) than in pCMV-HA group (100%, P<0.01). The G0/G1 phase proportion of MKN-45 cells was significantly higher in pCMV-E2F1-HA group than in pCMV-HA group (71.4% vs. 59.7%, P<0.05); the S phase proportion was significantly lower in pCMV-E2F1-HA group than in pCMV-HA group (18.7% vs. 30.7%, P<0.05). CONCLUSION: Overexpression of E2F-1 suppresses the proliferation of gastric cancer MKN-45 cells.