Objective:By analyzing the clinical data of patients with primary duodenal adenocarcinoma (PDA), the risk factors affecting the postoperative prognosis of PDA patients were discussed.Methods:The clinical data of 191 patients diagnosed with PDA in Peking University First Hospital from Jan 2009 to Dec 2022 were collected. The survival rate was calculated and the survival curve was plotted by Kaplan-Meier method. Univariate analysis was performed by Log-Rank test, and multivariate analysis was performed by COX proportional hazards regression model to obtain independent risk factors.Results:The median age of onset in patients with PDA is 65 years old, and the most common symptoms are abdominal pain and abdominal distension. Prognostic analysis showed that the survival rates at 1, 3 and 5 years were 73.8%, 44.6%, and 23.0%. The analysis of Cox risk proportional regression model showed that preoperative CA19-9 level, depth of tumor invasion, degree of differentiation, TNM stage, and surgical mode were independent risk factors for the prognosis of PDA (all P<0.01). Conclusion:The overall incidence of PDA is low, but the prognosis is rather poor. Multvariable factors are associated with its prognosis and surgery is still the mainstay for hope of cure.

Objective: More than 75% of ovarian cancer patients are diagnosed at advanced stages and die of tumor cell metastasis. This study aimed to identify new epigenetic and transcriptomic alterations associated with ovarian cancer metastasis. Methods: Two cell sublines with low- and high-metastasis potentials were derived from the ovarian cancer cell line A2780. Genome-wide DNA methylome and transcriptome profiling were carried out in these two sublines by Reduced Representation Bisulfite Sequencing and RNA-seq technologies. Cell-based assays were conducted to support the clinical findings. Results: There are distinct DNA methylation and gene expression patterns between the two cell sublines with low- and high-metastasis potentials. Integrated analysis identified 33 methylation-induced genes potentially involved in ovarian cancer metastasis. The DNA methylation patterns of two of them (i.e., SFRP1 and LIPG) were further validated in human specimens, indicating that they were hypermethylated and downregulated in peritoneal metastatic ovarian carcinoma compared to primary ovarian carcinoma. Patients with lower SFRP1 and LIPG expression tend to have a worse prognosis. Functionally, knockdown of SFRP1 and LIPG promoted cell growth and migration, whereas their overexpression resulted in the opposite effects. In particular, knockdown of SFRP1 could phosphorylate GSK3β and increase β-catenin expression, leading to deregulated activation of the Wnt/β-catenin signaling. Conclusion Many systemic and important epigenetic and transcriptomic alterations occur in the progression of ovarian cancer. In particular, epigenetic silencing of SFRP1 and LIPG is a potential driver event in ovarian cancer metastasis. They can be used as prognostic biomarkers and therapeutic targets for ovarian cancer patients.

Objective:To evaluate the safety of double and a half layered esophagojejunal anastomosis in radical gastrectomy.Methods:This prospective, multi-center, single-arm study was initiated by the Affiliated Cancer Hospital of Zhengzhou University in June 2021 (CRAFT Study, NCT05282563). Participating institutions included Nanyang Central Hospital, Zhumadian Central Hospital, Luoyang Central Hospital, First Affiliated Hospital of Henan Polytechnic University, First Affiliated Hospital of Henan University, Luohe Central Hospital, the People's Hospital of Hebi, First People's Hospital of Shangqiu, Anyang Tumor Hospital, First People's Hospital of Pingdingshan, and Zhengzhou Central Hospital Affiliated to Zhengzhou University. Inclusion criteria were as follows: (1) gastric adenocarcinoma confirmed by preoperative gastroscopy;(2) preoperative imaging assessment indicated that R0 resection was feasible; (3) preoperative assessment showed no contraindications to surgery;(4) esophagojejunostomy planned during the procedure; (5) patients volunteered to participate in this study and gave their written informed consent; (6) ECOG score 0–1; and (7) ASA score I–III. Exclusion criteria were as follows: (1) history of upper abdominal surgery (except laparoscopic cholecystectomy);(2) history of gastric surgery (except endoscopic submucosal dissection and endoscopic mucosal resection); (3) pregnancy or lactation;(4) emergency surgery for gastric cancer-related complications (perforation, hemorrhage, obstruction); (5) other malignant tumors within 5 years or coexisting malignant tumors;(6) arterial embolism within 6 months, such as angina pectoris, myocardial infarction, and cerebrovascular accident; and (7) comorbidities or mental health abnormalities that could affect patients' participation in the study. Patients were eliminated from the study if: (1) radical gastrectomy could not be completed; (2) end-to-side esophagojejunal anastomosis was not performed during the procedure; or (3) esophagojejunal anastomosis reinforcement was not possible. Double and a half layered esophagojejunal anastomosis was performed as follows: (1) Open surgery: the full thickness of the anastomosis is continuously sutured, followed by embedding the seromuscular layer with barbed or 3-0 absorbable sutures. The anastomosis is sutured with an average of six to eight stitches. (2) Laparoscopic surgery: the anastomosis is strengthened by counterclockwise full-layer sutures. Once the anastomosis has been sutured to the right posterior aspect of the anastomosis, the jejunum stump is pulled to the right and the anastomosis turned over to continue to complete reinforcement of the posterior wall. The suture interval is approximately 5 mm. After completing the full-thickness suture, the anastomosis is embedded in the seromuscular layer. Relevant data of patients who had undergone radical gastrectomy in the above 12 centers from June 2021 were collected and analyzed. The primary outcome was safety (e.g., postoperative complications, and treatment). Other studied variables included details of surgery (e.g., surgery time, intraoperative bleeding), postoperative recovery (postoperative time to passing flatus and oral intake, length of hospital stay), and follow-up conditions (quality of life as assessed by Visick scores).Result:[1] From June 2021 to September 2022,457 patients were enrolled, including 355 men and 102 women of median age 60.8±10.1 years and BMI 23.7±3.2 kg/m2. The tumors were located in the upper stomach in 294 patients, mid stomach in 139; and lower stomach in 24. The surgical procedures comprised 48 proximal gastrectomies and 409 total gastrectomies. Neoadjuvant chemotherapy was administered to 85 patients. Other organs were resected in 85 patients. The maximum tumor diameter was 4.3±2.2 cm, number of excised lymph nodes 28.3±15.2, and number of positive lymph nodes five (range one to four. As to pathological stage,83 patients had Stage I disease, 128 Stage II, 237 Stage III, and nine Stage IV. [2] The studied surgery-related variables were as follows: The operation was successfully completed in all patients, 352 via a transabdominal approach, 25 via a transhiatus approach, and 80 via a transthoracoabdominal approach. The whole procedure was performed laparoscopically in 53 patients (11.6%), 189 (41.4%) underwent laparoscopic-assisted surgery, and 215 (47.0%) underwent open surgery. The median intraoperative blood loss was 200 (range, 10–1 350) mL, and the operating time 215.6±66.7 minutes. The anastomotic reinforcement time was 2 (7.3±3.9) minutes for laparoscopic-assisted surgery, 17.6±1.7 minutes for total laparoscopy, and 6.0±1.2 minutes for open surgery. [3] The studied postoperative variables were as follows: The median time to postoperative passage of flatus was 3.1±1.1 days and the postoperative gastrointestinal angiography time 6 (range, 4–13) days. The median time to postoperative oral intake was 7 (range, 2–14) days, and the postoperative hospitalization time 15.8±6.7 days. [4] The safety-related variables were as follows: In total, there were 184 (40.3%) postoperative complications. These comprised esophagojejunal anastomosis complications in 10 patients (2.2%), four (0.9%) being anastomotic leakage (including two cases of subclinical leakage and two of clinical leakage; all resolved with conservative treatment); and six patients (1.3%) with anastomotic stenosis (two who underwent endoscopic balloon dilation 21 and 46 days after surgery, the others improved after a change in diet). There was no anastomotic bleeding. Non-anastomotic complications occurred in 174 patients (38.1%). All patients attended for follow-up at least once, the median follow-up time being 10 (3–18) months. Visick grades were as follows: Class I, 89.1% (407/457); Class II, 7.9% (36/457); Class III, 2.6% (12/457); and Class IV 0.4% (2/457).Conclusion:Double and a half layered esophagojejunal anastomosis in radical gastrectomy is safe and feasible.

Objective:To evaluate the safety of double and a half layered esophagojejunal anastomosis in radical gastrectomy.Methods:This prospective, multi-center, single-arm study was initiated by the Affiliated Cancer Hospital of Zhengzhou University in June 2021 (CRAFT Study, NCT05282563). Participating institutions included Nanyang Central Hospital, Zhumadian Central Hospital, Luoyang Central Hospital, First Affiliated Hospital of Henan Polytechnic University, First Affiliated Hospital of Henan University, Luohe Central Hospital, the People's Hospital of Hebi, First People's Hospital of Shangqiu, Anyang Tumor Hospital, First People's Hospital of Pingdingshan, and Zhengzhou Central Hospital Affiliated to Zhengzhou University. Inclusion criteria were as follows: (1) gastric adenocarcinoma confirmed by preoperative gastroscopy;(2) preoperative imaging assessment indicated that R0 resection was feasible; (3) preoperative assessment showed no contraindications to surgery;(4) esophagojejunostomy planned during the procedure; (5) patients volunteered to participate in this study and gave their written informed consent; (6) ECOG score 0–1; and (7) ASA score I–III. Exclusion criteria were as follows: (1) history of upper abdominal surgery (except laparoscopic cholecystectomy);(2) history of gastric surgery (except endoscopic submucosal dissection and endoscopic mucosal resection); (3) pregnancy or lactation;(4) emergency surgery for gastric cancer-related complications (perforation, hemorrhage, obstruction); (5) other malignant tumors within 5 years or coexisting malignant tumors;(6) arterial embolism within 6 months, such as angina pectoris, myocardial infarction, and cerebrovascular accident; and (7) comorbidities or mental health abnormalities that could affect patients' participation in the study. Patients were eliminated from the study if: (1) radical gastrectomy could not be completed; (2) end-to-side esophagojejunal anastomosis was not performed during the procedure; or (3) esophagojejunal anastomosis reinforcement was not possible. Double and a half layered esophagojejunal anastomosis was performed as follows: (1) Open surgery: the full thickness of the anastomosis is continuously sutured, followed by embedding the seromuscular layer with barbed or 3-0 absorbable sutures. The anastomosis is sutured with an average of six to eight stitches. (2) Laparoscopic surgery: the anastomosis is strengthened by counterclockwise full-layer sutures. Once the anastomosis has been sutured to the right posterior aspect of the anastomosis, the jejunum stump is pulled to the right and the anastomosis turned over to continue to complete reinforcement of the posterior wall. The suture interval is approximately 5 mm. After completing the full-thickness suture, the anastomosis is embedded in the seromuscular layer. Relevant data of patients who had undergone radical gastrectomy in the above 12 centers from June 2021 were collected and analyzed. The primary outcome was safety (e.g., postoperative complications, and treatment). Other studied variables included details of surgery (e.g., surgery time, intraoperative bleeding), postoperative recovery (postoperative time to passing flatus and oral intake, length of hospital stay), and follow-up conditions (quality of life as assessed by Visick scores).Result:[1] From June 2021 to September 2022,457 patients were enrolled, including 355 men and 102 women of median age 60.8±10.1 years and BMI 23.7±3.2 kg/m2. The tumors were located in the upper stomach in 294 patients, mid stomach in 139; and lower stomach in 24. The surgical procedures comprised 48 proximal gastrectomies and 409 total gastrectomies. Neoadjuvant chemotherapy was administered to 85 patients. Other organs were resected in 85 patients. The maximum tumor diameter was 4.3±2.2 cm, number of excised lymph nodes 28.3±15.2, and number of positive lymph nodes five (range one to four. As to pathological stage,83 patients had Stage I disease, 128 Stage II, 237 Stage III, and nine Stage IV. [2] The studied surgery-related variables were as follows: The operation was successfully completed in all patients, 352 via a transabdominal approach, 25 via a transhiatus approach, and 80 via a transthoracoabdominal approach. The whole procedure was performed laparoscopically in 53 patients (11.6%), 189 (41.4%) underwent laparoscopic-assisted surgery, and 215 (47.0%) underwent open surgery. The median intraoperative blood loss was 200 (range, 10–1 350) mL, and the operating time 215.6±66.7 minutes. The anastomotic reinforcement time was 2 (7.3±3.9) minutes for laparoscopic-assisted surgery, 17.6±1.7 minutes for total laparoscopy, and 6.0±1.2 minutes for open surgery. [3] The studied postoperative variables were as follows: The median time to postoperative passage of flatus was 3.1±1.1 days and the postoperative gastrointestinal angiography time 6 (range, 4–13) days. The median time to postoperative oral intake was 7 (range, 2–14) days, and the postoperative hospitalization time 15.8±6.7 days. [4] The safety-related variables were as follows: In total, there were 184 (40.3%) postoperative complications. These comprised esophagojejunal anastomosis complications in 10 patients (2.2%), four (0.9%) being anastomotic leakage (including two cases of subclinical leakage and two of clinical leakage; all resolved with conservative treatment); and six patients (1.3%) with anastomotic stenosis (two who underwent endoscopic balloon dilation 21 and 46 days after surgery, the others improved after a change in diet). There was no anastomotic bleeding. Non-anastomotic complications occurred in 174 patients (38.1%). All patients attended for follow-up at least once, the median follow-up time being 10 (3–18) months. Visick grades were as follows: Class I, 89.1% (407/457); Class II, 7.9% (36/457); Class III, 2.6% (12/457); and Class IV 0.4% (2/457).Conclusion:Double and a half layered esophagojejunal anastomosis in radical gastrectomy is safe and feasible.

Myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are bone marrow disorders characterized by cytopenias and progression to acute myeloid leukemia. Hypomethylating agents (HMAs) are Food and Drug Administration-approved therapies for MDS and MDS/MPN patients. HMAs have improved patients’ survival and quality of life when compared with other therapies. Although HMAs are effective in MDS and MDS/MPN patients, they are associated with significant toxicities that place a large burden on patients. Our goal is to develop a safer and more effective HMA from natural products. We previously reported that black raspberries (BRBs) have hypomethylating effects in the colon, blood, spleen, and bone marrow of mice. In addition, BRBs exert hypomethylating effects in patients with colorectal cancer and familial adenomatous polyposis. In the current study, we conducted a pilot clinical trial to evaluate the hypomethylating effects of BRBs in patients with low-risk MDS or MDS/MPN. Peripheral blood mononuclear cells (PBMCs) were isolated before and after three months of BRB intervention. CD45 + cells were isolated from PBMCs for methylation analysis using a reduced-representation bisulfite sequencing assay. Each patient served as their own matched control, with their measurements assessed before intervention providing a baseline for post-intervention results. Clinically, our data showed that BRBs were well-tolerated with no side effects. When methylation data was combined, BRBs significantly affected methylation levels of 477 promoter regions. Pathway analysis suggests that BRB-induced intragenic hypomethylation drives leukocyte differentiation. A randomized, placebo-controlled clinical trial of BRB use in low-risk MDS or MDS/ MPN patients is warranted.

Malignant tumor is a persistent disease that perplexes public health. Traditional treatment appears ineffective for patients with advanced metastasis. In recent years, immune checkpoint inhibitor therapy has developed rapidly and has great potential, but the overall clinical efficiency is still low. Carcinoma changes the tumor microenvironment through various mechanisms, resulting in immune resistance, which greatly reduces the efficacy of immune checkpoint inhibitors. Hyperthermia can not only play the anti-tumor advantage of thermal effect, but also play a direct and indirect immune sensitization effect through a variety of ways, transforming" cold tumor" into" hot tumor" , to enhance the impact of immune checkpoint inhibitors in many patterns. Numerous basic experiments have proved that hyperthermia combined with immune checkpoint inhibitors has achieved a classy impression in mice. Presently, some ongoing clinical trials of hyperthermia combined with immune checkpoint inhibitors have gained promising progress. In this paper, the merits of combination therapy were analyzed from three aspects: immune checkpoint inhibitors, hyperthermia, hyperthermia combined with immune checkpoint inhibitors, and the future research directions of hyperthermia combined with immune checkpoint inhibitors were prospected.

Numerous studies on cancers, biopharmaceuticals, and clinical trials have necessitated comprehensive and precise analysis of protein O-glycosylation. However, the lack of updated and convenient databases deters the storage of and reference to emerging O-glycoprotein data. To resolve this issue, an O-glycoprotein repository named OGP was established in this work. It was constructed with a collection of O-glycoprotein data from different sources. OGP contains 9354 O-glycosylation sites and 11,633 site-specific O-glycans mapping to 2133 O-glycoproteins, and it is the largest O-glycoprotein repository thus far. Based on the recorded O-glycosylation sites, an O-glycosylation site prediction tool was developed. Moreover, an OGP-based website is already available (http://www.oglyp.org/). The website comprises four specially designed and user-friendly modules:statistical analysis, database search, site prediction, and data submission. The first version of OGP repository and the website allow users to obtain various O-glycoprotein-related information, such as protein accession Nos., O-glycosylation sites, O-glycopeptide sequences, site-specific O-glycan structures, experimental methods, and potential O-glycosylation sites. O-glycosylation data mining can be performed efficiently on this website, which will greatly facilitate related studies. In addition, the database is accessible from OGP website (http://www.oglyp.org/download.php).

Objective:To evaluate the factors affecting the degree of radical resection and the prognosis of patients with locally recurrent rectal cancer (LRRC).Methods:A retrospective case-control study was performed. Clinical data of 111 patients with LRRC undergoing operation at the General Surgery Department of Peking University First Hospital from January 2009 to August 2019 were analyzed retrospectively. The "Peking University First Hospital F typing" was performed according to the preoperative images of the pelvic involvement. The pelvis was assigned into four directions: the front wall, lateral sides of the pelvic wall and the sacrum. According to the degree of pelvic wall involvement, F typing included F0 type (no involvement of the pelvic wall, the cancer only involved the adjacent organs or invaded conteriorly the urinary tract, genital organs or small intestine), F1 type (cancer involved the pelvic wall in one direction, such as the sacrum, or one side of the pelvic wall), F2 type (cancer involved the pelvic wall in two directions) and F3 type (cancer involved the pelvic wall in three directions). Case inclusion criteria: (1) LRRC was confirmed by imaging and pathological examination of samples (puncture or endoscopic biopsy); (2) complete clinical and follow-up data; (3) informed consent of patient. Those with dysfunction of heart, lung, etc., intolerance of operation, F3 type indicated by image, and distant metastasis were excluded. The degree of radical resection was evaluated according to the postoperative pathological results. Patients were followed up every 12 months and related examinations were arranged. The univariate analysis of radical resection was performed by χ 2 test, and the multivariate analysis was performed by logistic methods. The survival rate was calculated by Kaplan-Meier method and the survival curve was drawn. The survival rate was compared by log-rank test. Cox proportional hazards model was used to analyze the factors affecting the prognosis of patients with LRRC. Results:A total of 111 patients were included in this study. Of 111 patients, 59 were male and 52 were female; recurrent age of 36 cases was ≥ 65 years old; CEA level of 48 cases was ≥15 μg/L. According to the "Peking University First Hospital F typing", 70 cases were F0 type, 38 F1 type and 3 F2 type. Surgical procedures were abdominoperineal resection ( n=28), posterior pelvic exenteration ( n=32), and total pelvic exenteration ( n=51, including 1 case of TPE combined with sacrectomy). According to the postoperative pathological results, R0, R1 and R2 resections were 83, 20 and 8 cases, respectively. Univariate analysis showed that the degree of radical resection was associated with the secondary surgical procedure, F typing and lymph node metastasis (all P<0.05). Multivariate analysis showed that F typing (F1-F2) was an independent risk factor for non- R0 resection (OR=37.256, 95%CI:8.572 to 161.912, P<0.001). The morbidity of operative complications was 22.5% (25/111); the perioperative mortality was 1.8% (2/111); the local recurrence rate after the second operation was 37.8% (42/111). The 3- and 5-year overall survival rates were 41.2% and 21.9% respectively. The 3-year survival rates of patients with and without postoperative chemotherapy were 52.7% and 32.4% respectively ( P=0.005). The 3-year survival rates of patients with lower (<15 μg/L) and higher CEA level (≥15 μg/L) were 52.9% and 24.3% respectively ( P<0.001). The 3-year survival rates of patients with R0, R1 and R2 resection were 49.8%, 21.3% and 8.5% respectively ( P=0.002). The 3-year survival rates of patients with F0, F1 and F2 type were 52.7%, 22.0% and 0 respectively ( P<0.001). Cox analysis confirmed that the degree of radical resection (HR=2.088, 95%CI:1.095 to 3.979, P=0.025), the CEA level before the secondary operation (HR=1.857, 95%CI:1.157 to 2.980, P=0.010) and postoperative chemotherapy (HR=1.826, 95%CI:1.137 to 2.934, P=0.013) were independent factors affecting the prognosis. Conclusions:The indication of LRRC surgical treatments must be strictly limited. Evaluation of the fixation site to the pelvic wall is helpful for improving the rate of R0 resection. Lower preoperative CEA level, radical resection and postoperative chemotherapy are protective factors of prolonged overall survival time of patients with LRRC.

Objective:To evaluate the factors affecting the degree of radical resection and the prognosis of patients with locally recurrent rectal cancer (LRRC).Methods:A retrospective case-control study was performed. Clinical data of 111 patients with LRRC undergoing operation at the General Surgery Department of Peking University First Hospital from January 2009 to August 2019 were analyzed retrospectively. The "Peking University First Hospital F typing" was performed according to the preoperative images of the pelvic involvement. The pelvis was assigned into four directions: the front wall, lateral sides of the pelvic wall and the sacrum. According to the degree of pelvic wall involvement, F typing included F0 type (no involvement of the pelvic wall, the cancer only involved the adjacent organs or invaded conteriorly the urinary tract, genital organs or small intestine), F1 type (cancer involved the pelvic wall in one direction, such as the sacrum, or one side of the pelvic wall), F2 type (cancer involved the pelvic wall in two directions) and F3 type (cancer involved the pelvic wall in three directions). Case inclusion criteria: (1) LRRC was confirmed by imaging and pathological examination of samples (puncture or endoscopic biopsy); (2) complete clinical and follow-up data; (3) informed consent of patient. Those with dysfunction of heart, lung, etc., intolerance of operation, F3 type indicated by image, and distant metastasis were excluded. The degree of radical resection was evaluated according to the postoperative pathological results. Patients were followed up every 12 months and related examinations were arranged. The univariate analysis of radical resection was performed by χ 2 test, and the multivariate analysis was performed by logistic methods. The survival rate was calculated by Kaplan-Meier method and the survival curve was drawn. The survival rate was compared by log-rank test. Cox proportional hazards model was used to analyze the factors affecting the prognosis of patients with LRRC. Results:A total of 111 patients were included in this study. Of 111 patients, 59 were male and 52 were female; recurrent age of 36 cases was ≥ 65 years old; CEA level of 48 cases was ≥15 μg/L. According to the "Peking University First Hospital F typing", 70 cases were F0 type, 38 F1 type and 3 F2 type. Surgical procedures were abdominoperineal resection ( n=28), posterior pelvic exenteration ( n=32), and total pelvic exenteration ( n=51, including 1 case of TPE combined with sacrectomy). According to the postoperative pathological results, R0, R1 and R2 resections were 83, 20 and 8 cases, respectively. Univariate analysis showed that the degree of radical resection was associated with the secondary surgical procedure, F typing and lymph node metastasis (all P<0.05). Multivariate analysis showed that F typing (F1-F2) was an independent risk factor for non- R0 resection (OR=37.256, 95%CI:8.572 to 161.912, P<0.001). The morbidity of operative complications was 22.5% (25/111); the perioperative mortality was 1.8% (2/111); the local recurrence rate after the second operation was 37.8% (42/111). The 3- and 5-year overall survival rates were 41.2% and 21.9% respectively. The 3-year survival rates of patients with and without postoperative chemotherapy were 52.7% and 32.4% respectively ( P=0.005). The 3-year survival rates of patients with lower (<15 μg/L) and higher CEA level (≥15 μg/L) were 52.9% and 24.3% respectively ( P<0.001). The 3-year survival rates of patients with R0, R1 and R2 resection were 49.8%, 21.3% and 8.5% respectively ( P=0.002). The 3-year survival rates of patients with F0, F1 and F2 type were 52.7%, 22.0% and 0 respectively ( P<0.001). Cox analysis confirmed that the degree of radical resection (HR=2.088, 95%CI:1.095 to 3.979, P=0.025), the CEA level before the secondary operation (HR=1.857, 95%CI:1.157 to 2.980, P=0.010) and postoperative chemotherapy (HR=1.826, 95%CI:1.137 to 2.934, P=0.013) were independent factors affecting the prognosis. Conclusions:The indication of LRRC surgical treatments must be strictly limited. Evaluation of the fixation site to the pelvic wall is helpful for improving the rate of R0 resection. Lower preoperative CEA level, radical resection and postoperative chemotherapy are protective factors of prolonged overall survival time of patients with LRRC.

Objective To analyze the impact of Helicobacter pylori standard strain (Hp P12) and its virulence factor vacuolating cytotoxin A ( VacA) on DNA damage and homologous recombination ( HR) repair in a human gastric epithelial cell line (GES-1). Methods Strains of Hp P12 and vacA gene knock-out Hp P12 ( Hp P12 ΔvacA) were respectively used to infect GES-1 cells at a multiplicity of infection of 100. GES-1 cells treated with etoposide (50μmol/L) or mitomycin (0. 5μg/ml) for 2 h were used as posi-tive control. Western blot and immunofluorescence were performed to detect the expression of DNA damage marker protein γH2AX and key HR repair proteins (Rad51, pMRE11, CtIP and pCtIP) and the recruitment of them at DNA damage sites. Human embryonic kidney HEK-293 ( DR-GFP) cells were infected with Hp P12 and Hp P12 ΔvacA strains to verify the impact of VacA on HR repair efficiency. Results The expres-sion and recruitment of γH2AX and key HR repair proteins ( Rad51, pMRE11, CtIP and pCtIP) were in-creased in Hp P12-infected cells as compared with that in uninfected and Hp P12 ΔvacA-infected cells ( all P<0. 05). To evaluate the HR repair efficiency, I-SceⅠ plasmid-transfected HEK-293 (DR-GFP) cells were infected with Hp P12 and Hp P12 ΔvacA and the results showed that green fluorescent protein ( GFP)-positive cells were decreased after infection, especially in Hp P12 ΔvacA-infected cells (both P<0. 05). Conclusions Hp P12 infection could cause DNA damage and promote HR repair in GES-1 cells, in which the virulence factor VacA played an important role.