Shiga toxin 2 A-subunit induces mitochondrial damage, mitophagy and apoptosis via the interaction of Tom20 in Caco-2 cells.

Shiga toxin type 2 (Stx2) is the primary virulence factor produced by Shiga toxin-producing enterohemorrhagic Escherichia coli (STEC), which causes epidemic outbreaks of gastrointestinal sickness and potentially fatal sequela hemolytic uremic syndrome (HUS). Most studies on Stx2-induced apoptosis have been performed with holotoxins, but the mechanism of how the A and B subunits of Stx2 cause apoptosis in cells is not clear. Here, we found that Stx2 A-subunit (Stx2A) induced mitochondrial damage, PINK1/Parkin-dependent mitophagy and apoptosis in Caco-2 cells. PINK1/Parkin-dependent mitophagy caused by Stx2A reduced apoptosis by decreasing the accumulation of reactive oxidative species (ROS). Mechanistically, Stx2A interacts with Tom20 on mitochondria to initiate the translocation of Bax to mitochondria, leading to mitochondrial damage and apoptosis. Overall, these data suggested that Stx2A induces mitochondrial damage, mitophagy and apoptosis via the interaction of Tom20 in Caco-2 cells and that mitophagy caused by Stx2A ameliorates apoptosis by eliminating damaged mitochondria. These findings provide evidence for the potential use of Tom20 inhibition as an anti-Shiga toxin therapy.

MicroRNA-31 induced by Fusobacterium nucleatum infection promotes colorectal cancer tumorigenesis.

Persistent Fusobacterium nucleatum infection is associated with the development of human colorectal cancer (CRC) and promotes tumorigenicity, but the underlying mechanisms remain unclear. Here, we reported that F. nucleatum promoted the tumorigenicity of CRC, which was associated with F. nucleatum-induced microRNA-31 (miR-31) expression in CRC tissues and cells. F. nucleatum infection inhibited autophagic flux by miR-31 through inhibiting syntaxin-12 (STX12) and was associated with the increased intracellular survival of F. nucleatum. Overexpression of miR-31 in CRC cells promoted their tumorigenicity by targeting eukaryotic initiation factor 4F-binding protein 1/2 (eIF4EBP1/2), whereas miR-31 knockout mice were resistant to the formation of colorectal tumors. In conclusion, F. nucleatum, miR-31, and STX12 form a closed loop in the autophagy pathway, and continuous F. nucleatum-induced miR-31 expression promotes the tumorigenicity of CRC cells by targeting eIF4EBP1/2. These findings reveal miR-31 as a potential diagnostic biomarker and therapeutic target in CRC patients with F. nucleatum infection.

Isolation of Fusobacterium nucleatum from human feces using immunomagnetic separation coupled with fastidious anaerobe agar.

AIM: Fusobacterium nucleatum (F. nucleatum) is associated with the initiation, development, and metastasis of colorectal cancer. However, it is difficult to isolate F. nucleatum from clinical specimens. In this study, we aimed to develop an effective and rapid method for isolating F. nucleatum from human feces using polyclonal antibody (PAB)-coated immunomagnetic beads (IMBs) with selective media. METHODS AND RESULTS: IMBs conjugated with PAB were prepared and used to isolate F. nucleatum from human feces, and the bacteria were cultured with selective culture media (fastidious anaerobe agar + nalidixic acid + vancomycin). Under optimized experimental conditions, IMBs could selectively recover F. nucleatum from fecal microbiota samples spiked with Peptostreptococcus or Bacteroides fragilis. In artificial fecal samples, the detection sensitivity of IMBs for F. nucleatum was 103 CFU mL-1. In addition, IMBs combined with selective media could rapidly isolate F. nucleatum from human feces. CONCLUSIONS: This study successfully established an effective method for the rapid isolation of F. nucleatum from human feces by IMBs. The whole procedure requires 2-3 days, and has a sensitivity of 103 CFU mL-1 feces.

Fusobacterium nucleatum induces excess methyltransferase-like 3-mediated microRNA-4717-3p maturation to promote colorectal cancer cell proliferation.

Fusobacterium nucleatum infection plays vital roles in colorectal cancer (CRC) progression. Overexpression of microRNA-4717-3p (miR-4717) was reported to be upregulated in F. nucleatum positive CRC tissues, however, the underlying mechanism is unknown. In this study, we found that miR-4717 promoted CRC cell proliferation in vitro and growth of CRC in vivo following F. nucleatum infection. MicroRNA-4717 suppressed the expression of mitogen-activated protein kinase kinase 4 (MAP2K4), a tumor suppressor, by directly targeting its 3'-UTR. Furthermore, we confirmed that methyltransferase-like 3 (METTL3)-dependent m6 A methylation could methylate primary (pri)-miR-4717, which further promoted the maturation of pri-miR-4717, and METTL3 positively regulated CRC cell proliferation through miR-4717/MAP2K4 pathways. In conclusion, F. nucleatum-induced miR-4717 excessive maturation through METTL3-dependent m6 A modification promotes CRC cell proliferation, which provides a potential therapeutic target and diagnostic biomarker for CRC.

Long non-coding RNA EVADR induced by Fusobacterium nucleatum infection promotes colorectal cancer metastasis.

Both Fusobacterium nucleatum (F. nucleatum) and long non-coding RNA (lncRNA) EVADR are associated with colorectal cancer (CRC), but their relationship with CRC metastasis and the mechanisms by which EVADR promotes CRC metastasis are poorly understood. Here, we report that F. nucleatum promotes colorectal cancer cell metastasis to the liver and lung and that it can be detected in CRC-metastasis colonization in mouse models. Furthermore, F. nucleatum upregulates the expression of EVADR, which can increase the metastatic ability of CRC cells in vivo and in vitro. Mechanistically, elevated EVADR serves as a modular scaffold for the Y-box binding protein 1 (YBX1) to directly enhance the translation of epithelial-mesenchymal transition (EMT)-related factors, such as Snail, Slug, and Zeb1. These findings suggest that EVADR induced by F. nucleatum promotes colorectal cancer metastasis through YBX1-dependent translation. The EVADR-YBX1 axis may be useful for the prevention and treatment of patients with F. nucleatum-associated CRC metastasis.

Three novel immunogenic proteins determined through 2-Dimensional electrophoresis and mass spectrometry with immune serum confer protection against challenge with porcine Pasteurella multocida in mouse models.

Pasteurella multocida is an important zoonotic pathogen that causes multiple diseases in both animals and humans. Test of good immunogenic proteins is beneficial for vaccine development and disease control. In the present study, we determined four novel immunogenic proteins of P. multocida by using 2-DE MALDI-TOF MS with immune serum. These four proteins included a trimethylamine-N-oxide reductase TorA, a translation elongation factor Ts, a phosphoglyceromutase PGAM, and a peroxiredoxin PrX. Among these proteins, TorA, Prx, and PGAM were successfully expressed by using E. coli. Western-blotting assays showed that recombinant TorA, Prx, and/or PGAM displayed good reactions with infectious sera of P. multocida serogroups A, B, D and F. Immunization of either rTorA, rPrx, and/or rPGAM induced significantly high levels of antibodies as well as IFN-γ, IL-4 and IL-10 in mice (P < 0.01). Protective efficacy tests revealed that vaccination of either rTorA, rPrx, and/or rPGAM protected 60% ~ 80% of the tested mice against the challenge with P. multocida field isolate. Our results obtained from the present study suggest that these three proteins could be tested as good vaccine candidates against P. multocida infections.

Mine disaster survivor's pelvic floor hernia treated with laparoscopic surgery and a perineal approach: A case report.

BACKGROUND: A pelvic floor hernia is defined as a pelvic floor defect through which the intraabdominal viscera may protrude. It is an infrequent complication following abdominoperineal surgeries. This type of hernia requires surgical repair by conventional or reconstructive techniques. The main treatments could be transabdominal, transperineal or a combination. CASE SUMMARY: In this article, we present the case of a recurrent perineal incisional hernia, postresection of the left side of the pelvis, testis and lower limbs resulting from a mine disaster 18 years ago. Combined laparoscopic surgery with a perineal approach was performed. The pelvic floor defect was repaired by a biological mesh and one pedicle skin flap. No signs of recurrence were indicated during the 2 years of follow-up. CONCLUSION: The combination of laparoscopic surgery with a perineal approach was effective. The use of the biological mesh and pedicle skin flap to restructure the pelvic floor was effective.

Alteration of microRNA-4474/4717 expression and CREB-binding protein in human colorectal cancer tissues infected with Fusobacterium nucleatum.

Colorectal cancer (CRC) is a common and highly lethal form of cancer. Although the etiologic role of Fusobacterium nucleatum (F. nucleatum) in the development of CRC has been elucidated, the specific tumor molecules involved in the progression of CRC induced by F. nucleatum have not been identified. This study investigated several miRNAs and genes involved in the progression of F. nucleatum-induced CRC by Affymetrix miRNA microarray technology and GeneChip Human Transcriptome Array 2.0. The results suggest that miR-4474 and miR-4717 are up-regulated in CRC tissues in response to F. nucleatum infection, compared with the control group (paracancerous tissues), while other genes associated with signaling pathways in cancer, including CREB-binding protein (CREBBP), STAT1, PRKACB, CAMK2B, JUN, TP53 and EWSR1, were dysregulated. Bioinformatic analysis identified CREBBP as the primary aberrantly expressed gene in F. nucleatum-induced CRC. Consistent with the microarray analysis results, real-time RT-PCR analysis demonstrated that the expression of miR-4474/4717 was upregulated while that of CREBBP mRNA was downregulated in CRC patients infected with F. nucleatum. Additionally, CREBBP was identified as a novel target of miR-4474/4717. The results of this study suggest that miR-4474 and miR-4717 are involved in the progression of F. nucleatum-induced CRC by posttranscriptionally regulating the target gene CREBBP.

[Status of diagnosis and management of acute appendicitis in 2017: a national multi-center retrospective study].

OBJECTIVE: To analyze the current status of diagnosis and management of acute appendicitis (AA) in China. METHODS: Questionnaire survey was used to retrospectively collect data of hospitalized patients with AA from 43 medical centers nationwide in 2017 (Sort by number of cases provided: Jinling Hospital of Medical School of Nanjing University, The First Affiliated Hospital of Xinjiang Medical University, Lu'an People's Hospital, Tengzhou Central People's Hospital, Dalian Central Hospital, The Affiliated Hospital of Xuzhou Medical University, Dongying People's Hospital, Jinjiang Hospital of Traditional Chinese Medicine, Huangshan Shoukang Hospital, Xuyi People's Hospital, Nanjing Jiangbei People's Hospital, Lanzhou 940th Hospital of PLA, Heze Municipal Hospital, The First College of Clinical Medical Science of China Three Gorges University, Affiliated Jiujiang Hospital of Nanchang University, The Second People's Hospital of Hefei, Affiliated Central Hospital of Shandong Zaozhuang Mining Group, The Third People's Hospital of Kunshan City, Xuzhou First People's Hospital, The 81st Group Army Hospital of PLA, Linyi Central Hospital, The General Hospital of Huainan Eastern Hospital Group, The 908th Hospital of PLA, Liyang People's Hospital, The 901th Hospital of Joint Logistic Support Force, The Third Affiliated Hospital of Chongqing Medical University, The Fourth Hospital of Jilin University, Harbin Acheng District People's Hospital, The First Affiliated Hospital of Zhengzhou University, Nanjing Luhe People's Hospital, Taixing Municipal People's Hospital, Baotou Central Hospital, The Affiliated Hospital of Nantong University, Linyi People's Hospital, The 72st Group Army Hospital of PLA, Zaozhuang Municipal Hospital, People's Hospital of Dayu County, Taixing City Hospital of Traditional Chinese Medicine, Suzhou Municipal Hospital, Beijing Guang'anmen Hospital, Langxi County Hospital of Traditional Chinese Medicine, Nanyang Central Hospital, The Affiliated People's Hospital of Inner Mongolia Medical University).The diagnosis and management of AA were analyzed through unified summary. Different centers collected and summarized their data in 2017 and sent back the questionnaires for summary. RESULTS: A total of 8 766 AA patients were enrolled from 43 medical centers, including 4 711 males (53.7%) with median age of 39 years and 958 (10.9%) patients over 65 years old. Of 8 776 patients, 5 677 cases (64.6%) received one or more imaging examinations, and the other 3 099 (35.4%) did not receive any imaging examination. A total of 1 858 (21.2%) cases received medical treatment, mainly a combination of nitroimidazoles (1 107 cases, 59.8%) doublet regimen, followed by a single-agent regimen of non-nitroimidazoles (451 cases, 24.4%), a nitroimidazole-free doublet regimen (134 cases, 7.2%), a triple regimen of combined nitroimidazoles (116 cases, 6.3%), nitroimidazole alone (39 cases, 2.1%) and nitroimidazole-free triple regimen (3 cases, 0.2%). Of the 6 908 patients (78.8%) who underwent surgery, 4 319 (62.5%) underwent laparoscopic appendectomy and 2589 (37.5%) underwent open surgery. Ratio of laparotomy was higher in those patients under 16 years old (392 cases) or over 65 years old (258 cases) [15.1%(392/2 589) and 10.0%(258/2 589), respectively, compared with 8.5%(367/4 316) and 8.0%(347/4 316) in the same age group for laparoscopic surgery, χ²=91.415, P<0.001; χ²=15.915,P<0.001]. Patients with complicated appendicitis had higher ratio of undergoing open surgery as compared to those undergoing laparoscopic surgery [26.7%(692/2 589) vs. 15.6%(672/4 316), χ²=125.726, P<0.001].The cure rates of laparoscopic and open surgery were 100.0% and 99.8%(2 585/2 589) respectively without significant difference (P=0.206). Postoperative complication rates were 4.5%(121/2 589) and 4.7%(196/4 316) respectively, and the difference was not statistically significant (χ²=0.065, P=0.799). The incidence of surgical site infection was lower (0.6% vs. 1.7%, χ²=17.315, P<0.001), and hospital stay was shorter [6(4-7) days vs. 6(5-8) days, U=4 384 348.0, P<0.001] in the laparoscopic surgery group, while hospitalization cost was higher (median 12 527 yuan vs. 9 342 yuan, U=2 586 809.0, P<0.001). CONCLUSIONS: The diagnosis of acute appendicitis is still clinically based, supplemented by imaging examination. Appendectomy is still the most effective treatment at present. Laparoscopic appendectomy has become the main treatment strategy, but anti-infective drugs are also very effective.

Robotic Total Mesorectal Excision for Rectal Cancer: A Series of 392 Cases and Mid-Term Outcomes from A Single Center in China.

BACKGROUND: Robotic total mesorectal excision (RTME) for rectal cancer has recently been increasingly used; technical feasibility and short-term outcomes have been reported in detail. Few studies have presented clinical efficacy and mid-term outcomes for a large sample size. The aim of this study is to present oncologic efficacy and mid-term outcomes of robotic total mesorectal excision for rectal cancer and to provide our experiences regarding these surgically challenging issues. METHODS: Three hundred ninety-two patients received RTME between March 2010 and June 2015. Patient characteristics, perioperative clinical results, complications, pathologic details, recurrence, and mid-term outcomes were evaluated. RESULTS: Duration of surgery ranged from 80 to 388 min (median 224 min). There were no deaths during surgery and no anesthesiology complications in our series. The conversion rate was 1.1% (4/392). The postoperative complication rate was 10.2%; anastomosis leakage was the most common complication with an incidence of 4.1% (16/392). The median blood loss was 67.5±34.3 (20-600). The mean postoperative hospital stay was 12.1±6.1 (6-64). Circumferential resection margins were negative in 387 out of 392 cases (98.7%). The mean number of harvested lymph nodes was 14.6. Two deaths occurred during 30-day mortality. At a mean follow-up of 24 months (range 3-66 months), there were 35 deaths. CONCLUSION: Our results suggest that RTME is technically feasible for rectal cancer and can yield good short- and mid-term oncologic outcomes.

Fusobacterium nucleatum-Induced Impairment of Autophagic Flux Enhances the Expression of Proinflammatory Cytokines via ROS in Caco-2 Cells.

Fusobacterium nucleatum (F. nucleatum) plays a critical role in gastrointestinal inflammation. However, the exact mechanism by which F. nucleatum contributes to inflammation is unclear. In the present study, it was revealed that F. nucleatum could induce the production of proinflammatory cytokines (IL-8, IL-1ß and TNF-α) and reactive oxygen species (ROS) in Caco-2 colorectal) adenocarcinoma cells. Furthermore, ROS scavengers (NAC or Tiron) could decrease the production of proinflammatory cytokines during F. nucleatum infection. In addition, we observed that autophagy is impaired in Caco-2 cells after F. nucleatum infection. The production of proinflammatory cytokines and ROS induced by F. nucleatum was enhanced with either autophagy pharmacologic inhibitors (3-methyladenine, bafilomycin A1) or RNA interference in essential autophagy genes (ATG5 or ATG12) in Caco-2 cells. Taken together, these results indicate that F. nucleatum-induced impairment of autophagic flux enhances the expression of proinflammatory cytokines via ROS in Caco-2 Cells.

Comparison of laparoscopy-assisted and open radical gastrectomy for advanced gastric cancer: A retrospective study in a single minimally invasive surgery center.

Laparoscopy-assisted gastrectomy (LAG) has gained international acceptance for the treatment of early gastric cancer (EGC). However, the use of laparoscopic surgery in the management of advanced gastric cancer (AGC) has not attained widespread acceptance. This retrospective large-scale patient study in a single center for minimally invasive surgery assessed the feasibility and safety of LAG for T2 and T3 stage AGC. A total of 628 patients underwent LAG and 579 patients underwent open gastrectomy (OG) from Jan 2004 to Dec 2011. All cases underwent radical lymph node (LN) dissection from D1 to D2+. This study compared short- and long-term results between the 2 groups after stratifying by pTNM stages, including the mean operation time, volume of blood loss, number of harvested LNs, average days of postoperative hospital stay, mean gastrointestinal function recovery time, intra- and post-operative complications, recurrence rate, recurrence site, and 5-year survival curve. Thirty-five patients (5.57%) converted to open procedures in the LAG group. There were no significant differences in retrieved LN number (30.4 ±â€Š13.4 vs 28.1 ±â€Š17.2, P = 0.43), proximal resection margin (PRM) (6.15 ±â€Š1.63 vs 6.09 ±â€Š1.91, P = 0.56), or distal resection margin (DRM) (5.46 ±â€Š1.74 vs 5.40 ±â€Š1.95, P = 0.57) between the LAG and OG groups, respectively. The mean volume of blood loss (154.5 ±â€Š102.6 vs 311.2 ±â€Š118.9 mL, P < 0.001), mean postoperative hospital stay (7.6 ±â€Š2.5 vs 10.7 ±â€Š3.6 days, P < 0.001), mean time for gastrointestinal function recovery (3.3 ±â€Š1.4 vs 3.9 ±â€Š1.5 days, P < 0.001), and postoperative complications rate (6.4% vs 10.5%, P = 0.01) were clearly lower in the LAG group compared to the OG group. However, the recurrence pattern and site were not different between the 2 groups, even they were stratified by the TNM stage. The 5-year overall survival (OS) rates were 85.38%, 79.70%, 57.81%, 34.60% and 88.31%, 75.49%, 56.84%, 33.08% in patients with stage Ib, IIa, IIb, and IIIa, respectively, in the LAG and OG groups. There were no statistically significant differences in the OS rate for patients with the same TNM stage between the 2 groups. LAG with radical LN dissection is a safe and technically feasible procedure for the treatment of AGC staged below T3.

Single-Tubed Wild-Type Blocking Quantitative PCR Detection Assay for the Sensitive Detection of Codon 12 and 13 KRAS Mutations.

The high degree of intra-tumor heterogeneity has meant that it is important to develop sensitive and selective assays to detect low-abundance KRAS mutations in metastatic colorectal carcinoma (mCRC) patients. As a major potential source of tumor DNA in the aforementioned genotyping assays, it was necessary to conduct an analysis on both the quality and quantity of DNA extracted from formalin-fixed paraffin-embedded (FFPE). Therefore, four commercial FFPE DNA extraction kits were initially compared with respect to their ability to facilitate extraction of amplifiable DNA. The results showed that TrimGen kits showed the greatest performance in relation to the quality and quantity of extracted FFPE DNA solutions. Using DNA extracted by TrimGen kits as a template for tumor genotyping, a real-time wild-type blocking PCR (WTB-PCR) assay was subsequently developed to detect the aforementioned KRAS mutations in mCRC patients. The results showed that WTB-PCR facilitated the detection of mutated alleles at a ratio of 1:10,000 (i.e. 0.01%) wild-type alleles. When the assay was subsequently used to test 49 mCRC patients, the results showed that the mutation detection levels of the WTB-PCR assay (61.8%; 30/49) were significantly higher than that of traditional PCR (38.8%; 19/49). Following the use of the real-time WTB-PCR assay, the ΔCq method was used to quantitatively analyze the mutation levels associated with KRAS in each FFPE sample. The results showed that the mutant levels ranged from 53.74 to 0.12% in the patients analyzed. In conclusion, the current real-time WTB-PCR is a rapid, simple, and low-cost method that permits the detection of trace amounts of the mutated KRAS gene.

miR-203 suppression in gastric carcinoma promotes Slug-mediated cancer metastasis.

MicroRNAs (miRNAs) play critical roles in tumorigenesis and cancer metastasis. Recently, miR-203 was reported as a tumor suppressor microRNA silenced in different malignancies including hepatocellular carcinoma, prostate cancer, oral cancer, breast cancer, and hematopoietic malignancy, whereas its role in the carcinogenesis of gastric carcinoma (GC) has not been evaluated. Here, we analyzed the levels of miR-203 and Slug in the GC specimen and studied their correlation. We analyzed the binding of miR-203 to the 3'-UTR of Slug messenger RNA (mRNA) and its effects on Slug translation by bioinformatics analysis and by luciferase-reporter assay, respectively. We modified miR-203 levels in GC cells and studied their effects on the cell invasiveness in transwell cell migration assay. We found that in GC, miR-203 levels were significantly decreased and Slug levels were significantly increased. miR-203 and Slug inversely correlated in patients' specimen. Bioinformatic analysis predicted that miR-203 may target the 3'-UTR of Slug mRNA to inhibit its translation, which was confirmed by luciferase-reporter assay. Overexpression of miR-203 inhibited Slug and cell invasiveness, while depletion of miR-203 increased Slug and cell invasiveness. These data suggest that miR-203 suppression in GC promotes Slug-mediated cancer metastasis.

Dose-response meta-analysis of poultry intake and colorectal cancer incidence and mortality.

PURPOSE: Poultry intake has been inconsistently associated with incidence or mortality of colorectal cancer (CRC) in epidemiologic studies. The purpose of this study was to assess their relationships by performing a dose-response meta-analysis. METHODS: We conducted a search of PubMed database between January 1966 and July 2013 for prospective studies that reported relative risks (RRs) with 95 % confidence interval (CIs) of CRC for at least three categories of poultry intake. Dose-response relationships were examined with the generalized least-squares trend estimation. Study-specific results were pooled with a random-effects model. Subgroup, sensitivity, and meta-regression analyses were also conducted to explore heterogeneity. RESULTS: Sixteen studies on poultry intake and CRC incidence, and four studies regarding poultry intake and CRC mortality were identified. These studies involved a total of 13,949 incident CRC cases and 983 CRC deaths. The RRs of CRC for higher compared with lower intake of poultry were reported in these studies, and the reported levels of poultry intake varied substantially. Results of the dose-response meta-analysis conferred a RR of 0.89 (95 % CI 0.81-0.97) for an increase in poultry intake of 50 g/day. The results were not sensitive to any individual studies and were similar for colon and rectal cancer. Poultry intake was not associated with CRC mortality (RR for 50 g/day = 0.97, 95 % CI 0.79-1.20). CONCLUSIONS: This meta-analysis indicates that poultry intake may be moderately associated with reduced incidence of CRC.

Suppression of vascular endothelial growth factor abrogates the immunosuppressive capability of murine gastric cancer cells and elicits antitumor immunity.

The mechanisms underlying immune evasion by gastric cancer have not been well described due to a lack of gastric tumor models in immunocompetent mice. In the current study, we found that supernatants from MFC cells, a murine gastric cancer line, inhibited the lipopolysaccharide (LPS) induced maturation and cross-presentation of bone-marrow-derived dendritic cells (BMDCs). Moreover, MFC tumor-derived factors markedly altered the cytokine profiles of BMDCs, leading to a trend of increased levels of interleukin 4 (IL4), IL6, IL23 and transforming growth factor ß, as well as decreased levels of tumor necrosis factor α. qPCR and ELISA revealed that MFC cells expressed a high level of vascular endothelial growth factor (VEGF). Downregulating VEGF expression abrogated the inhibitory effect of MFC-derived factors on the maturation and cross-presentation of BMDCs. In addition, VEGF knockdown greatly impaired the tumorigenicity of MFC cells in immunocompetent mice. Compared with parental MFC tumors, VEGF-low MFC tumors grew much more slowly and the survival of tumor-inoculated mice was significantly improved. More importantly, mice rejecting inoculated VEGF-low MFC tumor cells gained resistance to re-challenged parental tumors, which was attributed to an antitumor immunity response against parental MFC tumors. These results reveal an immunosuppressive role for VEGF in murine gastric cancer.

Aberrant expression of Cx43 is associated with the peritoneal metastasis of gastric cancer and Cx43-mediated gap junction enhances gastric cancer cell diapedesis from peritoneal mesothelium.

The process of peritoneal metastasis involves the diapedesis of intra-abdominal exfoliated gastric cancer cells through the mesothelial cell monolayers; however, the related molecular mechanisms for this process are still unclear. Heterocellular gap-junctional intercellular communication (GJIC) between gastric cancer cells and mesothelial cells may play an active role during diapedesis. In this study we detected the expression of connexin 43 (Cx43) in primary gastric cancer tissues, intra-abdominal exfoliated cancer cells, and matched metastatic peritoneal tissues. We found that the expression of Cx43 in primary gastric cancer tissues was significantly decreased; the intra-abdominal exfoliated cancer cells and matched metastatic peritoneal tissues exhibited increasing expression compared with primary gastric cancer tissues. BGC-823 and SGC-7901 human gastric cancer cells were engineered to express Cx43 or Cx43T154A (a mutant protein that only couples gap junctions but provides no intercellular communication) and were co-cultured with human peritoneal mesothelial cells (HPMCs). Heterocellular GJIC and diapedesis through HPMC monolayers on matrigel-coated coverslips were investigated. We found that BGC-823 and SGC-7901 gastric cancer cells expressing Cx43 formed functional heterocellular gap junctions with HPMC monolayers within one hour. A significant increase in diapedesis was observed in engineered Cx43-expressing cells compared with Cx43T154A and control group cells, which suggested that the observed upregulation of diapedesis in Cx43-expressing cells required heterocellular GJIC. Further study revealed that the gastric cancer cells transmigrated through the intercellular space between the mesothelial cells via a paracellular route. Our results suggest that the abnormal expression of Cx43 plays an essential role in peritoneal metastasis and that Cx43-mediated heterocellular GJIC between gastric cancer cells and mesothelial cells may be an important regulatory step during metastasis. Finally, we observed that the diapedesis of exfoliated gastric cancer cells through mesothelial barriers is a viable route of paracellular migration.

[Short-term efficacy of da Vinci robotic surgical system on rectal cancer in 101 patients].

OBJECTIVE: To investigate the feasibility and safety of da Vinci robotic surgical system in rectal cancer radical operation, and to summarize its short-term efficacy and clinical experience. METHODS: Data of 101 cases undergoing da Vinci robotic surgical system for rectal cancer radical operation from March 2010 to September 2012 were retrospectively analyzed. Evaluation was focused on operative procedure, complication, recovery and pathology. RESULTS: All the 101 cases underwent operation successfully and safely without conversion to open procedure. Rectal cancer radical operation with da Vinci robotic surgical system included 73 low anterior resections and 28 abdominoperineal resections. The average operative time was (210.3±47.2) min. The average blood lose was (60.5±28.7) ml without transfusion. Lymphadenectomy harvest was 17.3±5.4. Passage of first flatus was (2.7±0.7) d. Distal margin was (5.3±2.3) cm without residual cancer cells. The complication rate was 6.9%, including anastomotic leakage(n=2), perineum incision infection(n=2), pulmonary infection (n=2), urinary retention (n=1). There was no postoperative death. The mean follow-up time was(12.9±8.0) months. No local recurrence was found except 2 cases with distant metastasis. CONCLUSION: Application of da Vinci robotic surgical system in rectal cancer radical operation is safe and patients recover quickly The short-term efficacy is satisfactory.

Autophagy protects against oxaliplatin-induced cell death via ER stress and ROS in Caco-2 cells.

Oxaliplatin is included in a number of effective combination regimens used as first and subsequent lines of therapy for metastatic colorectal cancer. Accumulating evidence indicates that autophagy plays a significant role in response to cancer therapy. However, the role of autophagy in oxaliplatin-induced cell death remains to be clarified. In this study, we showed that oxaliplatin induced cell death and autophagy in Caco-2 colorectal cancer cells. The suppression of autophagy using either pharmacologic inhibitors (3-methyladenine, bafilomycin A1) or RNA interference in essential autophagy genes (ATG5 or Beclin1) enhanced the cell death and reactive oxygen species (ROS) production induced by oxaliplatin in Caco-2 cells. Blocking oxaliplatin-induced ROS production by using ROS scavengers (NAC or Tiron) decreased autophagy. Furthermore, numerous dilated endoplasmic reticula (ER) were present in oxaliplatin-treated Caco-2 cells, and blocking ER stress by RNA interference against candidate of metastasis-1 (P8) and C/EBP-homologous protein (CHOP) decreased autophagy and ROS production. Taken together, these data indicate that oxaliplatin activates autophagy as a cytoprotective response via ER stress and ROS in human colorectal cancer cells.