SIVA-1 interaction with PCBP1 serves as a predictive biomarker for cisplatin sensitivity in gastric cancer and its inhibitory effect on tumor growth in vivo.

Background: SIVA-1 has been reported to play a key role in cell apoptosis and gastric cancer (GC) chemoresistance in vitro. Nevertheless, the clinical significance of SIVA-1 in GC chemotherapy remains unclear. Methods and results: Immunohistochemistry and histoculture drug response assays were used to determine SIVA-1 expression and the inhibition rate (IR) of agents to GC and to further analyze the relationship between these two phenomena. Additionally, cisplatin (DDP)-resistant GC cells were used to elucidate the role and mechanism of SIVA-1 in vivo. The results demonstrated that SIVA-1 expression was positively correlated with the IR of DDP to GC but not with those of 5-fluorouracil (5-FU) or adriamycin (ADM). Furthermore, SIVA-1 overexpression with DDP treatment synergistically inhibited tumor growth in vivo by increasing PCBP1 and decreasing Bcl-2 and Bcl-xL expression. Conclusions: Our study demonstrated that SIVA-1 may serve as an indicator of the GC sensitivity to DDP, and the mechanism of SIVA-1 in GC resistance to DDP was preliminarily revealed.

Inflammatory proteins may mediate the causal relationship between gut microbiota and inflammatory bowel disease: A mediation and multivariable Mendelian randomization study.

This research investigates the causal relationships among gut microbiota, inflammatory proteins, and inflammatory bowel disease (IBD), including crohn disease (CD) and ulcerative colitis (UC), and identifies the role of inflammatory proteins as potential mediators. Our study analyzed gut microbiome data from 13,266 samples collected by the MiBioGen alliance, along with inflammatory protein data from recent research by Zhao et al, and genetic data on CD and UC from the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC). We used Mendelian randomization (MR) to explore the associations, complemented by replication, meta-analysis, and multivariable MR techniques for enhanced accuracy and robustness. Our analysis employed several statistical methods, including inverse-variance weighting, MR-Egger, and the weighted median method, ensuring comprehensive and precise evaluation. After MR analysis, replication and meta-analysis, we revealed significant associations between 11 types of gut microbiota and 17 inflammatory proteins were associated with CD and UC. Mediator MR analysis and multivariable MR analysis showed that in CD, the CD40L receptor mediated the causal effect of Defluviitaleaceae UCG-011 on CD (mediation ratio 8.3%), and the Hepatocyte growth factor mediated the causal effect of Odoribacter on CD (mediation ratio 18%). In UC, the C-C motif chemokine 4 mediated the causal effect of Ruminococcus2 on UC (mediation ratio 4%). This research demonstrates the interactions between specific gut microbiota, inflammatory proteins, and CD and UC. Furthermore, the CD40L receptor may mediate the relationship between Defluviitaleaceae UCG-011 and CD; the Hepatocyte growth factor may mediate the relationship between Odoribacter and CD; and the C-C motif chemokine 4 may mediate the relationship between Ruminococcus2 and UC. The identified associations and mediation effects offer insights into potential therapeutic approaches targeting the gut microbiome for managing CD and UC.

SIVA-1 enhances acquired chemotherapeutic drug resistance of gastric cancer in vivo by regulating the ARF/MDM2/p53 pathway.

SIVA-1 has been shown to affect apoptotic processes in various different cell lines, and SIVA-1 significantly contributes to the decreased responsiveness of cancer cells to some chemotherapy agents. However, whether SIVA-1 has potential application in gastric cancer remains unknown. Therefore, the objective of this investigation was to clarify the distinct function of SIVA-1 in chemotherapeutic drug resistance within a living murine model with gastric malignancy, and initially elucidate the underlying mechanisms. In an established multidrug-resistant gastric cancer xenograft mouse model, lentivirus, named Lv-SIVA-1, was injected into xenograft tumors, and increased the mRNA and protein expression of endogenous SIVA-1 in tumors. Immunohistochemical assays of xenograft tumor showed that SIVA-1 was significantly upregulated, and the protein expression levels of SIVA-1 were highly increased, as detected by Western blotting. In addition, we detected the role of SIVA-1 in cell proliferation and cell apoptosis in gastric cancer cells by TUNEL and found that SIVA-1 decreased tumor cell apoptosis and promoted tumor growth in vivo. Using a TMT assay between tumor tissues of experimental and control groups, differentially expressed proteins were examined and three potential biomarkers of multidrug resistance (ARF, MDM2, and p53) were screened. We further investigated the molecular mechanism by which SIVA-1 played an efficient role against chemotherapies and found that overexpressed SIVA-1 leads to increased ARF and MDM2 expression and suppressed expression of p53 in tumor tissue. In conclusion, SIVA-1 plays a significant role in the multidrug resistance of gastric tumors. In addition, overexpressed SIVA-1 positively regulates cell proliferation, adjusts cycle progression, and reduces the response to drug treatment for gastric cancer in an ARF/MDM2/p53-dependent manner. This novel research provides a basis for chemical management of gastric cancer through regulation of SIVA-1 expression.

Trocar puncture with modified sump drainage for duodenal stump fistula after radical gastrectomy for gastric cancer: A retrospective controlled study.

Duodenal stump fistula (DSF) is a serious complication of radical gastrectomy for gastric cancer. Herein, we illustrated an innovative choice for treating duodenal stump fistulas by placing a modified sump drainage through trocar puncture into the DSF-related abscess (DSF-abscess) cavity. We retrospectively analyzed 974 consecutive patients who underwent gastrectomy for gastric cancer between 2011 and 2021. Of these patients, 34 who developed postoperative duodenal stump fistulas postoperatively were enrolled into our study, and their clinical data were retrospectively assessed. From January 2011 to December 2017, 15 patients received conventional treatments (percutaneous catheter drainage, PCD group) known as the traditional percutaneous method, and 19 patients from January 2018 to December 2021 received new treatments (Troca's SD group) consisting of conventional therapies and placement of a modified sump drainage through trocar puncture into DSF-abscess cavity. The demographics, clinical characteristics and treatment outcomes were compared between two groups. Compared with the PCD group, the rates of postoperative complications, duodenostomy creation, subsequent surgery, fistula healing rates of the DSF, and length of postoperative hospital stay were significantly decreased in the Troca SD group. However, there was no significant difference in the abscess recurrence rate and mortality rates. Trocar puncture with a modified sump drainage is an safe, effective, and technically feasible treatment for duodenal stump fistula after radical gastrectomy for gastric cancer. This novel technique should be further investigated using large-scale RCT research.

Epidemiology and nomogram for predicting the cancer-specific survival of ovarian granulosa cell tumor: A seer database study.

OBJECTIVE: ovarian granulosa cell tumor (OGCT) is a kind of infrequent ovarian malignant tumor with limited epidemiological data available. we established a predictive nomograph to verify the clinical prognosis. METHODS: 1005 diagnosed with ovarian granulosa cell tumor (OGCT) were extracted from Surveillance, Epidemiology, and End Results (SEER) public database from 2000-2018. Kaplan-Meier analysis was applied to distinguish risk factors, univariate and multivariate Cox analyses were used to determine the independent prognostic factors for cancer-specific survival (CSS) of OGCT patients. The obtained prognostic variables were combined to construct a nomogram model for predicting CSS in OGCT patients. RESULTS: Model performance was detected and evaluated with ROC curves and calibration plots. Data collected from 1005 patients were divided into two groups: training cohort(n=703,70%) and validation cohort(n=302,30%). The multivariate Cox model identified five covariates including age, marital status, AJCC stages, surgery and chemotherapy as independent interfering factors of CSS. The nomogram has shown a promising and excellent accuracy in evaluating 3 -, 5 -, 8-year CSS in OGCT patients. In terms of the CSS of the training cohort, the AUC values of the 3 -, 5 -, 8-year ROC curves were 0.819,0.8,0.819, while in terms of the CSS of the validation cohort, the AUC values of the validation cohort were 0.822,0.84,0.823, respectively. All the calibration curves showed pleasant consistency between predicted and actual survival rates. The nomogram model established in the study can improve the veracity of prognosis prediction, thereby improving the accuracy of individualized survival risk assessment, and providing targeted and constructive recommendations for specific treatment options. CONCLUSION: Age, advanced clinical stage, widower and without surgery therapy are independent risk factors for poor prognosis and the nomogram we constructed can help clinicians efficiently recognize high-risk OGCT patients to guide targeted therapies and improve their outcomes.

Propensity score-matched comparison between totally laparoscopic right hemicolectomy with transcolonic natural orifice specimen extraction and conventional laparoscopic surgery with mini-laparotomy in the treatment of ascending colon cancer (with video).

BACKGROUND AND AIMS: Now that the debate about the safety and effectiveness of laparoscopic versus open surgery is over, attention has turned to innovations that can verify whether minimizing the impact of laparoscopy on the abdominal wall can further reduce pain, improve patient comfort, lead to superior cosmesis, and reduce morbidity. The aim of this study was to further explore the application value of totally laparoscopic right hemicolectomy with transcolonic natural orifice specimen extraction (NOSE) and to evaluate the short-term efficacy of transcolonic NOSE surgery for resecting specimens of ascending colon cancer. METHODS: From January 2016 to May 2017, a retrospective study was conducted in Guangxi. Propensity score matching was used to minimize the bias from nonrandomized treatment assignment. Patients were followed up through May 2020. RESULTS: Forty-nine patients underwent totally laparoscopic right hemicolectomy with transcolonic NOSE and 116 patients laparoscopic right hemicolectomy with mini-laparotomy (ML) procedures at our institution. After propensity score matching, each group included 45 patients, and all covariate imbalances were alleviated. The transcolonic NOSE group and the ML group did not differ significantly in terms of baseline clinical characteristics. The transcolonic NOSE group was associated with a shorter time to first flatus (NOSE vs ML: 1.8 ± .5 vs 3.2 ± .8, P = .032), a shorter length of hospital stay (11.3 ± 2.5 days vs 13.0 ± 3.1 days, P = .034), a shorter time to first liquid intake (2.6 ± .8 vs 3.8 ± .9, P = .068), less pain (1.8 ± .8 vs 4.2 ± .7, P = .013), less analgesia requirement (6 [13.3%] vs 21 [46.7%], P = .001), and lower C-reactive protein levels on postoperative day 1 (3.6 ± 1.7 vs 8.2 ± 2.2, P = .001) and postoperative day 3 (NOSE 2.4 ± 1.4 vs M: 4.6 ± 1.7 [P = .013]) than the ML group. The median follow-up was 28.4 months (interquartile range, 18.0-36.0). The 3-year overall survival rates were similar between the transcolonic NOSE group and the ML group. CONCLUSIONS: In total, laparoscopic right hemicolectomy with transcolonic specimen extraction appears to be safe for selected patients with ascending colon cancer as a minimally invasive surgery.

Lentivirus-Mediated Overexpression of SIVA-1 Reverses Cisplatin Resistance in Gastric Cancer in vitro.

SIVA-1 plays a critical role in the induction of apoptosis in a number of different cell lines and participates in the mechanism of cisplatin (DDP)-mediated antitumor effects. However, the involvement of SIVA-1 in cisplatin resistance in gastric carcinoma has not been revealed. To explore the effect of SIVA-1 on DDP resistance, a recombinant pGV358-GFP-SIVA-1 lentiviral vector was constructed and transfected into human cisplatin-resistant MKN45/DDP gastric cancer cells. Subsequently, stable SIVA-1 overexpression was established in MKN45/DDP cells, which resulted in increased DDP sensitivity in MKN45/DDP cells in vitro. Flow cytometry demonstrated that SIVA-1 overexpression increased the percentage of apoptotic cells compared to that in the control. The colony formation assay clearly revealed that cell growth and proliferation were significantly suppressed following SIVA-1 overexpression. In addition, overexpression of SIVA-1 inhibited the migratory and invasive potential of MKN45/DDP cells in vitro. Western blot analysis indicated that SIVA-1 increased the expression levels of p53, p73, and p14ARF, whereas it reduced Bcl-2, MDM2, and Bcl-xL expression. In short, SIVA-1 upregulated the protein expression of p53, p73, and p14ARF and decreased that of Bcl-2, MDM2, and Bcl-xL in vitro and subsequently reversed cisplatin resistance in gastric cancer cells, suggesting that SIVA-1 serves as a valuable potential target for attenuating chemotherapy resistance.

Siva­1 regulates multidrug resistance of gastric cancer by targeting MDR1 and MRP1 via the NF­κB pathway.

Siva­1 is a well­known anti­apoptosis protein that serves a role in multiple types of cancer cells. However, whether Siva­1 affects multidrug resistance via the NF­κB pathway in gastric cancer is currently unknown. The present study aimed to determine the possible involvement of Siva­1 in gastric cancer anticancer drug resistance in vitro. A vincristine (VCR)­resistant KATO III/VCR gastric cancer cell line with stable Siva­1 overexpression was established. The protein expression levels of Siva­1, NF­κB, multidrug resistance 1 (MDR1) and multidrug resistance protein 1 (MRP1) were detected via western blotting. The effect of Siva­1 overexpression on anticancer drug resistance was assessed by measuring the 50% inhibitory concentration of KATO III/VCR cells to VCR, 5­fluorouracil and doxorubicin. The rate of doxorubicin efflux and apoptosis were detected by flow cytometry. Additionally, colony formation, wound healing and Transwell assays were used to detect the proliferation, migration and invasion of cells, respectively. The results of the current study revealed that the Siva­1­overexpressed KATO III/VCR gastric cancer cells exhibited a significantly decreased sensitivity to VCR, 5­fluorouracil and doxorubicin. The results of flow cytometry revealed that the percentage of apoptotic cells decreased following overexpression of Siva­1. The colony formation assay demonstrated that cell growth and proliferation were significantly promoted by Siva­1 overexpression. Additionally, Siva­1 overexpression increased the migration and invasion of KATO III/VCR cells in vitro. Western blot analysis determined that Siva­1 overexpression increased NF­κB, MDR1 and MRP1 levels. The current study demonstrated that overexpression of Siva­1, which functions as a regulator of MDR1 and MRP1 gene expression in gastric cancer cells via promotion of NF­κB expression, inhibited the sensitivity of gastric cancer cells to certain chemotherapies. These data provided novel insight into the molecular mechanisms of gastric cancer, and may be of significance for the clinical diagnosis and therapy of patients with gastric cancer.

Surgical-related risk factors associated with anastomotic leakage after resection for rectal cancer: a meta-analysis.

OBJECTIVES: Anastomotic leakage (AL) after anterior resection always leads to longer hospital stays, decreased quality of life and even increased mortality. Despite extensive research, no consensus on the world well-concerned surgical-related risk factors exists. We therefore conducted a meta-analysis of the available published literature to identify the effects of surgical-related risk factors for AL after anterior resection for rectal cancer, hoping to provide more information and improved guidance for clinical workers managing patients with rectal cancer who are at a high risk for AL. METHODS: In this study, the relevant articles were systematically searched from EMBASE, MEDLINE, PubMed, WangFang (Database of Chinese Ministry of Science & Technology), Chinese National Knowledge Infrastructure Database and China Biological Medicine Database. The pooled odds ratio (OR) with 95% confidence interval (95% CI) were calculated. Meta-analysis was performed using of RevMan 5.3 software. RESULTS: A total of 26 studies met the inclusion criteria and comprised 34238 cases. Analysis of these 26 studies showed that no defunctioning stoma was highly correlated with AL (pooled OR = 1.28, 95%CI: 1.05-1.57, P = 0.01, random effect), and intraoperative blood transfusion was significantly associated with AL (pooled OR = 1.64, 95%CI: 1.34-2.02, P = 0.02, random effect). However, the AL was not associated with type of anastomosis, type of surgery, technique of anastomosis, level of inferior mesenteric artery ligation, operation time and splenic flexure mobilization. CONCLUSIONS: Depend on this meta-analysis, no defunctioning stoma and intraoperative blood transfusion are the major surgical-related risk factors for AL after resection for rectal cancer. Because of the inherent limitations of the research, future prospective randomized controlled trials will need to confirm this conclusion.

MUC1 Immunohistochemical Expression as a Prognostic Factor in Gastric Cancer: Meta-Analysis.

MUC1, a member of the mucin family, is expressed in tumors of various human organs and may function as an antiadhesion molecule that inhibits cell-to-cell adhesion, inducing tumor metastasis, and served as a potential biomarker of tumor progression in early gastric cancer. However, its prognostic significance in gastric cancer is still in dispute. We performed a meta-analysis to evaluate the relationship between MUC1 expression and prognosis of gastric cancer. A total of ten eligible studies with 834 cases and 548 controls were included. MUC1 positive cases were highly positive in intestinal-type carcinomas (OR = 1.76, 95% CI: 1.27-2.44, P = 0.0008 fixed-effect), higher rate of vascular invasion (OR = 1.64, 95% CI: 1.13-2.39, P = 0.009 fixed-effect), and lymph node metastasis (OR = 2.10, 95% CI: 1.20-3.67, P = 0.01 random-effect), as well as lower 5-year survival rate (HR = 0.27, 95% CI: 0.11-0.66, P = 0.004 random-effect). However, the presence of MUC1 was not associated with gender, tumor size, histologic differentiation, and clinical stage. In summary, MUC1 is a prognostic factor in gastric cancer, which acts as a marker of poor outcome in patients with gastric cancer. Further clinical studies are needed to confirm the role of MUC1 in clinical practice.

Meta-analysis of oncological outcome after abdominoperineal resection or low anterior resection for lower rectal cancer.

In lower rectal cancer, postoperative outcome is still subject of controversy between the advocates of abdominoperineal resection (APR) and low anterior resection (LAR). Reports suggest that low anterior resection may be oncologically superior to abdominoperineal excision, although no good evidence exists to support this. Publications were identified which assessed the differences comparing 5-year survival, local recurrence, circumferential resection margin rate, complications and so on. A meta-analysis was performed to clarify the safety and feasibility of the two procedures with several types of outcome measures. A total of 13 studies met the inclusion criteria, and comprised 6,850 cases. Analysis of these data showed that LAR group was highly correlated with 5-year survival (pooled OR = 1.73, 95%CI: 1.30-2.29, P = 0.0002 random-effect). And local recurrence rate of APR group was significantly higher than that in LAR group (pooled OR = 0.63, 95%CI: 0.53-0.75, P < 0.00001 fixed-effect). Also, the circumferential resection margin (CRM) were high involved in APR group than in LAR group. (5 trials reported the data, pooled OR = 0.43, 95%CI: 0.36-0.52, P < 0.00001 fixed-effect). Besides, the incidents of overall complications of APR group was higher compared with LAR group (pooled OR = 0.52, 95%CI: 0.29-0.92, P = 0.03 random-effect). Patients treated by APR have a higher rate of CRM involvement, a higher local recurrence, and poorer prognosis than LAR. And there is evidence that in selected low rectal cancer patients, LAR can be used safely with a better oncological outcome than APR. due to the inherent limitations of the present study, for example, the trails available for this systematic review are limited and the finite retrospective data, future prospective randomized controlled trials will be useful to fully investigate these outcome measures and to confirm this conclusion.

[Commercial orange juice beverages detection by fluorescence spectroscopy combined with PCA-ED and PLSR methods].

In order to classify the orange juiice beverages effectively, the fluorescence character differences of two kinds of orange juice beverages including 100% orange juice and orange drink were analyzed and compared, principal component analysis combined with Euclidean distance was adopted to classify two kinds of orange juice beverages, and ideal classification results were obtained. Meanwhile, the orange juice content estimation model was established by using fluorescence spectroscopy combined with partial least squares regression method, and the correlation coefficient R, root mean square error of calibration RMSEC and root mean square error of prediction RMSEP were 0.997, 0.87% and 2.05%, respectively. The experimental results indicate that the calibration model offers comparatively accurate content estimation, which reflect the actual orange juice content in the commercial orange juice beverages. The exploration to classify orange juice beverages was carried out from two aspects of qualitative and quantitative analysis by employing fluorescence spectroscopy combined with chemometrics method, which can provide a new idea for the classification and adulteration detection of commercial orange juice beverages, and also can give certain reference basis for the quality control of orange juice raw material.

[Quantitative analysis of two food colors using excitation-emission matrix spectra coupled with parallel factor algorithm].

In the present paper, British Edinburgh FLS920P Steady State and Time-Resolved Fluorescence Spectrometer was applied to measure three dimensional fluorescence spectra of 12 pigment solution samples and the parallel factor algorithm was combined with the excitation-emission matrix to find a way to detect the food colors. In the experiment, making use of CORCONDIA determination method to confirm that the number of the components is 3 in mixed solution, and then by using parallel factor analysis (PARAFAC) algorithms, get the average recoveries of carminum and Allura red were 99.3% +/- 5.0% and 102.2% +/- 5.6%, and the root mean square errors of prediction (RMSEP) were 0.054 and 0.205, respectively. The results show that the method can be applied to determine carminum and Allura red in the mixed solution simultaneously even in the presence of interfering amaranth, which was simple and convenient, rapid, etc, and provides references for synthetic food pigments detection.

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.

[Determination of carmine in carbonated beverages using 3-D fluorescence spectra coupled with second-order calibration algorithm].

Three-dimensional fluorescence spectra combined with second-order calibration algorithm based on alternate a weighted residual (ANWE) was applied to the direct concentration determination of carmine in carbonated beverages. Firstly, 3-D fluorescence spectra of carmine and sunset yellow mixed solutions with different concentrations were obtained by employing spectrometer, and analyzed by using ANWE, the correlation coefficient between calibration concentration and the actual concentration was 0.9917, and the average recovery was 100.92%±2.71%. The results show that the ANWE algorithm is reliable. Then, the commercial carbonated soft drinks in 8, 9, 12 and 13 times diluted concentration were detected by using ANWE algorithm, the correlation coefficient between relative concentration and the actual concentration were 0.9930, 0.9930, 0.9932 and 0.7932, respectively, and the contents of carmine in beverage were 38.88, 37.71, 37.68 and 39.65 µg · mL(-1), respectively. The average concentration was (38.48±0.96) µg · mL(-1). Finally, the standard addition method was applied to estimate the prediction accuracy between calibration concentration and the actual concentration was 0.9935, and the average recovery was 102.99%±2.15%. The results can provide a new idea for the rapid content determination of food pigments in commercial beverages.

[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.