[Circular RNA-Encoded Proteins in Gastrointestinal Cancer:A Review].

Circular RNAs(CircRNAs)are a class of non-coding RNAs with a covalently closed-loop structure,high stability,and tissue specificity,with the production mechanisms different from linear RNAs.Recent studies have discovered that some CircRNAs can encode proteins via cap-independent translation mechanisms such as internal ribosome entry site,N6-methyladenosine,and rolling loop translation.The encoded proteins regulate homologous linear proteins or downstream signaling pathways via protein bait or other mechanisms,thereby exerting biological functions.Studies have shown that CircRNAs play a role in various diseases,especially in tumor progression,proliferation,invasion,and metastasis and immune regulation.Therefore,by elucidating the expression and roles of proteins encoded by CircRNAs in tumorigenesis and development,this paper is expected to provide new tumor markers and potential targets for tumor diagnosis and treatment.

Comparative study of oncologic efficacy of cephalomedial to lateral dissection versus medial to lateral dissection in laparoscopic total mesorectal excision for rectal cancer: An RCT study.

BACKGROUND AND OBJECTIVES: We compared the 3-year overall survival between cephalomedial-to-lateral approach proctectomy (CEMP) and medial-to-lateral approach proctectomy (MAP) in patients undergoing laparoscopic total mesorectal excision for rectal cancer. The advantages of CEMP and the clinical value of No. 253 lymph nodes resection have not been objectively analyzed in literature. METHODS: This was a prospective, two-arm, multicenter, single-blinded, randomized trial. The primary endpoint was 3-year overall survival, and secondary endpoints included safety, feasibility, oncological radicality (including number of No. 253 lymph nodes harvested), short-term outcome, 3-year disease-free survival, rate of postoperative complications, mortality, and rate of recurrence. RESULTS: From May 2016 to July 2020, 506 patients were enrolled-256 in the CEMP group and 250 in the MAP group. Comparison of overall survival and disease-free survival showed that there was treatment benefit in the CEMP group (28.22 ± 12.12 vs. 27.44 ± 13.06, p = 0.485; 27.24 ± 12.01 vs. 26.42 ± 12.81; p = 0.457). More No. 253 lymph nodes were harvested in the CEMP group, and cases with positive No. 253 lymph nodes had worse prognosis in stage III. Surgical safety was equal for both approaches. CONCLUSIONS: Dissection of No. 253 lymph nodes may be important to improve clinical prognosis, but further studies with larger samples are needed to confirm this finding.

Identification of Varieties of Dried Red Jujubes with Near-Infrared Hyperspectral Imaging.

In order to realize rapid identification of dried red jujubes, this paper proposes a method based on near-infrared hyperspectral imaging technology. The near-infrared hyperspectral images (1 000～1 600 nm) of 240 samples in total from 4 cultivars of dried red jujubes will be acquired. The samples are to be divided into the calibration set and the prediction set in the ratio of 2∶1. 7, 8, 10 effective wavelengths are to be selected by principal component analysis(PCA), x-loading weight(x-LW)and successive projection algorithm(SPA) respectively. The dimensionality of original hyperspectral images will be reduced with PCA, and texture features of the first principal component image are to be extracted with gray-level co-occurrence matrix(GLCM).The partial least squares-discriminant analysis(PLS-DA), back propagation neural network(BPNN)and least square support vector machine(LS-SVM) are to be applied to build identification models with the selected effective wavelengths, texture features and fusion of the former two features. The identification rates of the models based on fusion features will be higher than those of models based on the spectral features or texture features respectively. The BPNN models based on the fusion features will obtain the best results, whose identification rates of prediction set are to be 100%. The results in this paper indicate that the near-infrared hyperspectral imaging technology has great potential to identify the dried red jujubes rapidly.

[Study on Visual Identification of Corn Seeds Based on Hyperspectral Imaging Technology].

The seed purity is an important indicator of seed quality. The paper proposes a visual identification method of corn seed based on the near-infrared (874~1,734 nm) hyperspectral image technology. Hyperspectral image data of 4 cultivars of a total of 384 corn seed samples will be acquired. Then 288 of samples are to be selected randomly as the calibration set, and the remaining 96 samples will be used for the prediction set. After inspection of the near-infrared spectral curves, 7 effective wavelengths (EWs) are to be selected by successive projection algorithm (SPA). And then 7 EWs of the calibration set will be used as input to build a partial least squares (PLS) model. Good results are to be obtained with Rc = 0.917 7, RMSECV = 0.444 2; Rcv = 0.911 5, RMSECV = 0.459 9. And the total identification rate of the developed PLS model will be 78.5% for the calibration set and 70.8% for the prediction set. Finally, average spectral data of each corn seed in a hyperspectral image will be extracted by image process technology, and used as input of the developed SPA-PLS model. In the produced identification map, different colors are to be used to represent different predicted cultivars. 3 mixture samples of corn seeds will be identified, and help to achieve satisfied visual effects. The result indicates that, by means of the visual identification technology we could intuitively observe the distribution of corn seeds of different cultivars in mixture samples. The research provides help for the identification and screening of seeds in agricultural production.

[Study on Non-Detective Determination of ß-Carotene Content in Loquats with Raman Spectroscopy].

In china, researches on Raman spectroscopy in terms of foodstuff mainly focus on carbohydrates, fatty acids, proteins and vitamins. Conventional methods for determining the carotenoids content require the extraction of the samples as well as other cleanup steps. In this work, Raman spectroscopy is applied to get the measured value form loquats with different mature stage which are compared with the reference value get from High Performance Liquid Chromatography (HPLC)，in order to find new, fast, and nondestructive calibration methods for quantification of ß-carotene content in loquat fruits. Least Squares Support Vector Machine and Partial least squares data processing methods are used to analyze the Raman spectra while PLS model has a prediction quality with the correlation coefficient of 0.845; the root-mean-square error of 0.022 µg·g(-1) and LS-SVM model has a better prediction quality with the correlation coefficient of 0.910 with the root-mean-square error of 0.058 µg·g(-1).

[Study on the Visualization of the Biomass of Chlorella sp., Isochrysis galbana, and Spirulina sp. Based on Hyperspectral Imaging Technique].

Effective cultivation of the microalgae is the key issue for microalgal bio-energy utilization. In nutrient rich culture conditions, the microalge have a fast growth rate, but they are more susceptible to environmental pollution and influence. So to monitor the the growth process of microalgae is significant during cultivating. Hyperspectral imaging has the advantages of both spectra and image analysis. The spectra contain abundant material quality signal and the image contains abundant spatial information of the material about the chemical distribution. It can achieve the rapid information acquisition and access a large amount of data. In this paper, the authors collected the hyperspectral images of forty-five samples of Chlorella sp., Isochrysis galbana, and Spirulina sp., respectively. The average spectra of the region of interest (ROI) were extracted. After applying successive projection algorithm (SPA), the authors established the multiple linear regression (MLR) model with the spectra and corresponding biomass of 30 samples, 15 samples were used as the prediction set. For Chlorella sp., Isochrysis galbana, and Spirulina sp., the correlation coefficient of prediction (r(pre)) are 0.950, 0.969 and 0.961, the root mean square error of prediction (RMSEP) for 0.010 2, 0.010 7 and 0.007 1, respectively. Finally, the authors used the MLR model to predict biomass for each pixel in the images of prediction set; images displayed in different colors for visualization based on pseudo-color images with the help of a Matlab program. The results show that using hyperspectral imaging technique to predict the biomass of Chlorella sp. and Spirulina sp. were better, but for the Isochrysis galbana visualization needs to be further improved. This research set the basis for rapidly detecting the growth of microalgae and using the microalgae as the bio-energy.

[Study on the Nondestructive Detection Methods for Dynamica Change of Lipid Content in Chlorella sp.].

Microalgae based biodiesel production requires a large amount of lipid accumulation in the cells, and the accumulation is greatly influenced by the environment. Therefore, it is necessary to find fast and non-destructive methods for lipid change detection. In this paper, Chlorella sp. was adopted as the objective, which was cultured under different light condition consisted of red and blue lights with different proportion. We applied the visible near-infrared spectroscopy (Vis/NIRs) technique to detect the dynamic change of lipid during the microalgae growth processes and utilized hyperspectral imaging technology for visualization of lipid distribution in the suspension. The transmittance and reflectance spectra of microalgae were acquired with Vis/NIRs and hyper-spectroscopy, respectively. In the comparison of the transmittance and reflectance spectra, they showed some different characteristics. Meanwhile it also varied in terms of the number and the area of feature wavelengths obtained by successive projections algorithm (SPA) based on the different spectra. But the established multiple linear regression (MLR) model for lipid content prediction had similar results with rpre of 0.940, RMSEP of 0.003 56 and rpre of 0.932, RMSEP of 0.004 23, respectively. Based on the predictive model, we obtained the spectra and analyzed the lipid dynamic change in microalgae in one life cycle. In the life cycle, the lipid content in Chlorella sp. was relatively stable from the beginning of inoculation to exponential phase, the increase and accumulation of lipid phenomenon occurred in the late exponential phase. Combined with the MLR model and the hypersepctral images, we studied the visualization result of microalgae suspension in the steady phase. The stimulated images showed that the microalgae with higher lipid content appeared gathering. This study compared the difference and the feasibility of the Vis/NIRs and hyperspectral imaging technique in lipid content detection applied in microalgae growing microalgae. The results are meaningful for the fast and non-destructive detection of the growth information of microalgae. It has boththeoretical and practical significance for developing microalgal culture and harvest strategy in practice.

Preoperative diabetes as a protective factor for pancreatic fistula after pancreaticoduodenectomy: a meta-analysis.

BACKGROUND: The role of diabetes mellitus (DM) in pancreatic fistula (PF) or clinical relevant PF (CR-PF) after pancreaticoduodenectomy (PD) or pylorus-preserving pancreaticoduodenectomy (PPPD) is unclear. We conducted a meta-analysis to investigate the relationship between DM and PF or CR-PF. DATA SOURCES: Embase, MEDLINE and Cochrane databases were searched systematically for relevant articles from January 2005 to June 2013. The selected studies that examined clinical risk factors of PF or CR-PF were included. We created pooled estimates for our outcomes using the random-effects model. RESULTS: Sixteen observational clinical studies were included. Pooling of PF rates from ten studies revealed that DM was associated with a decreased risk of PF (P=0.01). CR-PF rates from 8 studies showed no significant difference between DM and control group (P=0.14). CONCLUSIONS: DM is not a risk factor for PF in patients undergoing PD or PPPD. On the contrary, patients without DM are at a higher risk of PF because the pancreases in these patients have more fatty tissue and the pancreas is soft.

Application of international videoconferences for continuing medical education programs related to laparoscopic surgery.

BACKGROUND: Continuing medical education (CME) is an effective way for practicing physicians to acquire up-to-date clinical information. MATERIALS AND METHODS: We conducted four CME seminars in 2007-2010 endorsed by the Chinese Medical Association Council on Medical Education. Overseas telelectures and live case demonstrations were introduced in each seminar via telemedicine based on a digital video transport system. Network stability and packet loss were recorded. An anonymous mini-questionnaire was conducted to evaluate the satisfaction of attendees regarding the image and sound quality, content selection, and overall evaluation. RESULTS: Four telelectures and five live case demonstrations were successfully conducted. Stability of the network was maintained during each videoconference. High-quality videos of 720 × 480 pixels at the rate of 30 frames per second were shown to the entire group of attendees. The time delay between Shanghai and Fukuoka, Japan, was only 0.3 s, and the packet loss was 0%. We obtained 129 valid responses to the mini-questionnaire from a total of 146 attendees. The majority of the attendees were satisfied with the quality of transmitted images and voices and with the selected contents. The overall evaluation was ranked as excellent or good. CONCLUSIONS: Videoconferences are excellent channels for CME programs associated with laparoscopic training.

Insights into the history and tendency of glycosylation and digestive system tumor: A bibliometric-based visual analysis.

BACKGROUND: Glycosylation, a commonly occurring post-translational modification, is highly expressed in several tumors, specifically in those of the digestive system, and plays a role in various cellular pathophysiological mechanisms. Although the importance and detection methods of glycosylation in digestive system tumors have garnered increasing attention in recent years, bibliometric analysis of this field remains scarce. The present study aims to identify the developmental trends and research hotspots of glycosylation in digestive system tumors. AIM: To find and identify the developmental trends and research hotspots of glycosylation in digestive system tumors. METHODS: We obtained relevant literature from the Web of Science Core Collection and employed VOSviewer 1.6.19 and CiteSpace (version 6.1.R6) to perform bibliometric analysis. RESULTS: A total of 2042 documents spanning from 1978 to the present were analyzed, with the research process divided into three phases: the period of obscurity (1978-1990), continuous development period (1991-2006), and the rapid outbreak period (2007-2023). These documents were authored by researchers from 66 countries or regions, with the United States and China leading in terms of publication output. Reis Celso A had the highest number of publications, while Pinho SS was the most cited author. Co-occurrence analysis revealed the most popular keywords in this field are glycosylation, expression, cancer, colorectal cancer, and pancreatic cancer. Furthermore, the Journal of Proteome Research was the most prolific journal in terms of publications, while the Journal of Biological Chemistry had the most citations. CONCLUSION: The bibliometric analysis shows current research focus is primarily on basic research in this field. However, future research should aim to utilize glycosylation as a target for treating tumor patients.

Hypoxia-induced snail expression through transcriptional regulation by HIF-1α in pancreatic cancer cells.

BACKGROUND: Intratumoral hypoxia and epithelial-mesenchymal transition are involved in tumor invasion and metastasis. AIMS: This study investigated the molecular mechanisms that relay the hypoxia signal into the epithelial-mesenchymal transition and metastasis. METHODS: Morphology analysis and tumor cell migration and invasion assays were performed to detect phenotypic changes of pancreatic cancer cells under normoxic and hypoxic conditions after lentiviral HIF-1α shRNA transfection. Quantitative reverse transcription polymerase chain reaction, western blot, and immunohistochemistry were used to detect gene expression in pancreatic cancer cell lines and tissues or normal pancreatic tissues. Luciferase, gel shift, and ChIP assays were used to assess gene regulation. RESULTS: Under hypoxic conditions, these tumor cells underwent typical morphological and molecular changes to epithelial-mesenchymal transition. Moreover, Snail expression was induced by hypoxic conditions and was regulated by HIF-1α expression at the transcriptional level through HIF-1α-binding to the second site of hypoxia-responsive elements of the Snail gene promoter. In addition, Snail expression was associated with HIF-1α expression in pancreatic cancer tissues, and expression of both was associated with tumor metastasis and poor patient survival. CONCLUSIONS: Our study provides key evidence that HIF-1α and Snail are responsible for hypoxia-induced metastasis phenotypes in pancreatic cancer and that HIF-1α and Snail expression can be used as biomarkers to predict tumor metastasis and patient survival.

Current research status of endoscopic submucosal dissection for colorectal neoplasms.

Endoscopic submucosal dissection (ESD) has been applied to, and gradually standardized for, early gastric cancers; however, it has not yet been widely used for treatment of colorectal neoplasms. Compared with gastric ESD, the thinner colorectal wall and winding nature of the colon make colorectal ESD a much more difficult operative technique. Despite greater risks of postoperative complications, particularly perforation of the colon, more and more endoscopists are making an effort to study this new technique in terms of its capability of larger neoplastic resection, higher en bloc resection rate and lower local recurrence rate of neoplasms in comparison with other endoscopic treatments. Thus, colorectal ESD may become the standard treatment for early colorectal neoplasms in the future. This review article discusses the current research on endoscopic submucosal dissection for colorectal neoplasms. Please see supplementary files for the accompanying video ESD with snare.

Long noncoding RNA negative regulator of antiviral response contributes to pancreatic ductal adenocarcinoma progression via targeting miR-299-3p.

BACKGROUND: Pancreatic ductal cancer (PDAC) has high malignancy and poor prognosis. Long noncoding RNAs (lncRNAs) are associated with high levels of malignancy, including PDAC. However, the biological and clinical significance of negative regulator of antiviral response (NRAV) in PDAC is unclear. AIM: To study the regulatory role of lncRNA NRAV in PDAC. METHODS: GEPIA analyzed lncRNA NRAV and miRNA (miR-299-3p) expression levels in PDAC tissues and measured them in PDAC cells by quantitative measurements in real time. The specific role of NRAV and miR-299-3p in cell proliferation and transfer potential was evaluated by cell formation analysis, Cell Counting Kit-8 and Transwell analysis. The relationship between NRAV and miR-299-3p was studied by predictive bioinformatics, RNA immunoassay, and fluorescence enzyme analysis. In vivo experiments included transplantation of simulated tumor cells under naked mice. RESULTS: The expression level of lncRNA NRAV was higher in both tumor tissues and cell lines of PDAC and was negatively associated with the clinical survival of PDAC patients. Functionally, overexpression of NRAV promoted cell proliferation and metastasis of PDAC cells, while knockdown of NRAV reversed these effects. Finally, NRAV was performed as a molecular sponge of miR-299-3p. Moreover, overexpression of miR-299-3p could reverse the promoting effects of NRAV on cell proliferation and metastasis of PDAC cells. CONCLUSION: NRAV facilitates progression of PDAC as a molecular sponge of miR-299-3p and may be a potential molecular marker for diagnosis and treatment of PDAC.

Correction to "Genome-wide CRISPR-Cas9 screening identifies that hypoxia-inducible factor-1a-induced CBX8 transcription promotes pancreatic cancer progression via IRS1/AKT axis".

[This corrects the article on p. 1709 in vol. 13, PMID: 34853645.].

Expression and prognostic significance of CD151, c-Met, and integrin alpha3/alpha6 in pancreatic ductal adenocarcinoma.

BACKGROUND: CD151, c-Met, and integrin alpha3/alpha6 are all involved in the hepatocyte growth factor (HGF)/c-Met signal pathway, which plays an important role in the malignant progression of tumors. AIMS: The purpose of this study was to explore the expression and prognostic significance of these proteins in pancreatic ductal adenocarcinoma (PDAC). METHODS: We used immunohistochemical methods to investigate the expression patterns of CD151, c-Met, and integrin alpha3/alpha6proteins in 71 patients with PDAC and in ten samples of normal pancreatic tissue. We also assessed correlations between these proteins and clinicopathological parameters and survival of PDAC patients using various statistical methods. RESULTS: CD151, c-Met, and integrin alpha3/alpha6 were all overexpressed in PDAC. CD151 and c-Met overexpressions were significantly associated with TNM stage (p=0.001 and p=0.038, respectively) and lymph node invasion (p=0.000, p=0.012, respectively). A significant positive linear correlation was found between CD151 and c-Met (r=0.583; p=0.000), integrin alpha3 (r=0.457; p=0.000), and integrin alpha6 (r=0.671; p=0.000). Overexpression of CD151, c-Met, integrin alpha3, or integrin alpha6 was related to poor survival of PDAC patients (p=0.000, p=0.000, p=0.005, and p=0.003, respectively), and CD151 and c-Met were independent factors in prognosis of PDAC. CONCLUSIONS: CD151, c-Met, and integrin alpha3/alpha6 were all overexpressed in PDAC. CD151 and c-Met might be new molecular markers to predict the prognosis of PDAC patients.

Long non-coding RNA TP73-AS1 promotes pancreatic cancer growth and metastasis through miRNA-128-3p/GOLM1 axis.

BACKGROUND: Previous studies have suggested that long non-coding RNAs (lncRNA) TP73-AS1 is significantly upregulated in several cancers. However, the biological role and clinical significance of TP73-AS1 in pancreatic cancer (PC) remain unclear. AIM: To investigate the role of TP73-AS1 in the growth and metastasis of PC. METHODS: The expression of lncRNA TP73-AS1, miR-128-3p, and GOLM1 in PC tissues and cells was detected by quantitative real-time polymerase chain reaction. The bioinformatics prediction software ENCORI was used to predict the putative binding sites of miR-128-3p. The regulatory roles of TP73-AS1 and miR-128-3p in cell proliferation, migration, and invasion abilities were verified by Cell Counting Kit-8, wound-healing, and transwell assays, as well as flow cytometry and Western blot analysis. The interactions among TP73-AS1, miR-128-3p, and GOLM1 were explored by bioinformatics prediction, luciferase assay, and Western blot. RESULTS: The expression of TP73-AS1 and miRNA-128-3p was dysregulated in PC tissues and cells. High TP73-AS1 expression was correlated with a poor prognosis. TP73-AS1 silencing inhibited PC cell proliferation, migration, and invasion in vitro as well as suppressed tumor growth in vivo. Mechanistically, TP73-AS1 was validated to promote PC progression through GOLM1 upregulation by competitively binding to miR-128-3p. CONCLUSION: Our results demonstrated that TP73-AS1 promotes PC progression by regulating the miR-128-3p/GOLM1 axis, which might provide a potential treatment strategy for patients with PC.

Genome-wide CRISPR-Cas9 screening identifies that hypoxia-inducible factor-1a-induced CBX8 transcription promotes pancreatic cancer progression via IRS1/AKT axis.

BACKGROUND: Pancreatic cancer (PC) is one of the most lethal malignancies worldwide. It is known that the proliferation of PC cells is a critical process in the disease. Previous studies have failed to identify the key genes associated with PC cell proliferation, using bioinformatic analysis, genome-wide association studies, and candidate gene testing. AIM: To investigate the function of the chromobox 8 (CBX8)/receptor substrate 1 (IRS1)/AKT axis in PC. METHODS: A genome-wide CRISPR-Cas9 screening was performed to select genes that could facilitate PC cell proliferation. Quantitative reverse transcription-polymerase chain reaction was used to detect the expression of CBX8 in PC tissues and cells. The regulatory roles of CBX8 in cell proliferation, migration, and invasion were verified by in vivo and in vitro functional assays. RESULTS: CBX8 was upregulated in PC tissues and shown to drive PC cell proliferation. Higher expression of CBX8 was correlated with worse outcomes of PC patients from two independent cohorts comprising a total of 116 cases. CBX8 was also proved to serve as a promising therapeutic target for a PC xenograft model. We demonstrated that hypoxia-inducible factor (HIF)-1a induced CBX8 transcription by binding to the promoter of CBX8. CBX8 efficiently activated the PI3K/AKT signaling by upregulating insulin IRS1. CONCLUSION: CBX8 is a key gene regulated by HIF-1α, and activates the IRS1/AKT pathway, which suggests that targeting CBX8 may be a promising therapeutic strategy for PC.

MiR-301a transcriptionally activated by HIF-2α promotes hypoxia-induced epithelial-mesenchymal transition by targeting TP63 in pancreatic cancer.

BACKGROUND: Pancreatic cancer (PC) is one of the deadliest cancers worldwide. PC metastasis involves a complex set of events, including epithelial-mesenchymal transition (EMT), that increase tumor cell invasiveness. Recent evidence has shown that hypoxia is a major EMT regulator in pancreatic cancer cells and facilitates metastasis; however, the mechanisms remain elusive. AIM: To investigate the role of miR-301a in hypoxia-induced EMT in PC cells. METHODS: Real-time PCR and Western blot analysis were used to detect the expression of miR-301a and EMT markers in PDAC cells cultured in hypoxic and normoxic conditions. Western blot analysis was used to detect the expression of EMT markers in PDAC cells with miR-301a overexpression. Wound healing assay and Transwell assay were used to detect the migration capabilities of PDAC cells with miR-301a overexpression and knockout. Luciferase assay was used to detect the miR-301a promoter and the 3' untranslated region activity of TP63. Orthotopic PC mouse models were used to study the role of miR-301a in metastasis of PDAC cells in vivo. In situ hybridization assay was used to detect the expression of miR-301a in PDAC patient samples (adjacent paratumor and paired tumor tissues). . RESULTS: Hypoxic environment could directly promote the EMT of PC cells. The expression level of miR-301a was increased in a HIF2α dependent manner in hypoxia-cultured CFPAC-1 and BxPC-3 cells. Overexpression of miR-301a enhanced the hypoxia-induced EMT of PC cells, while knocking out miR-301a result in the suppression of hypoxia-induced EMT. TP63 was a direct target of miR-301a and involved in the metastatic process of PC cells. Furthermore, miR-301a upregulation facilitated PDAC distant metastasis and lymph node metastasis in vivo. Additionally, miR-301a overexpression was indicative of aggressive clinicopathological behaviors and poor prognosis. CONCLUSION: The newly identified HIF-2α-miR301a-TP63 signaling pathway may play a crucial role in hypoxia-induced EMT in PDAC cells.

Uncompressed video image transmission of laparoscopic or endoscopic surgery for telemedicine.

Traditional narrowband telemedicine cannot provide quality dynamic images. We conducted videoconferences of laparoscopic and endoscopic operations via an uncompressed video transmission technique. A superfast broadband Internet link was set up between Shanghai in the People's Republic of China and Fukuoka in Japan. Uncompressed dynamic video images of laparoscopic and endoscopic operations were transmitted by a digital video transfer system (DVTS). Seven teleconferences were conducted between June 2005 and June 2007. Of the 7 teleconferences, 5 were live surgical demonstrations and 3 were recorded video teleconsultations. Smoothness of the motion picture, sharpness of images, and clarity of sound were benefited by this form of telemedicine based upon DVTS. Telemedicine based upon DVTS is a superior choice for laparoscopic and endoscopic skill training across the borders.

[Effect of RNAi-mediated STAT3 gene inhibition on metastasis of human pancreatic cancer cells].

OBJECTIVE: To investigate the effect of RNAi-mediated STAT3 gene inhibition on metastasis of human pancreatic cancer cells and its underlying mechanism. METHODS: STAT3 shRNA expression vector was constructed and transfected into SW1990 cells. STAT3 mRNA and STAT3 DNA-binding activity were examined using reverse transcription polymerase chain reaction (RT-PCR) and electrophoretic mobility shift assay (EMSA), respectively. The metastasis ability of SW1990 cells in vivo was determined in acute hematogenous metastasis model using nude mice. RT-PCR was performed to detect the mRNA expression of the MMP-2 and VEGF. RESULTS: The mRNA expression of STAT3 and STAT3 DNA-binding activity were inhibited significantly by stable transfection of STAT3 shRNA expressing vectors. RNAi inhibition of STAT3 significantly suppressed the metastasis ability of SW1990 cells in vivo, and also markedly reduced the mRNA expression of MMP-2 and VEGF in SW1990 cells. CONCLUSIONS: Inhibition of STAT3 by RNAi significantly inhibits the metastasis ability of pancreatic cancer cells through down-regulation of MMP-2 and VEGF, and may provide a novel strategy for preventing the metastasis of pancreatic cancer.