Comparative long-term outcomes of natural orifice specimen extraction surgery and conventional laparoscopic colectomy for left-sided colorectal cancer: a propensity score-matched analysis

BACKGROUND

Natural orifice specimen extraction surgery (NOSES) is currently widely used in left-sided colorectal cancer. Some clinical comparative studies have been conducted, providing evidence of its safety and oncological benefits. However, these studies are typically characterized by small sample sizes and short postoperative follow-up periods. Consequently, in this research, the authors adopt the propensity score matching method to undertake a large-scale retrospective comparative study on NOSES colectomy for left-sided colorectal cancer, with the goal of further augmenting the body of evidence-based medical support for NOSES.

METHODS

This retrospective study involved patients who underwent NOSES colectomy and conventional laparoscopic (CL) colectomy for left-sided colorectal cancer between January 2014 and April 2021. In the NOSES group, specimens were extracted through the anus with the help of a Cai tube (homemade invention: ZL201410168748.2). The patients were matched at a ratio of 1:1 according to age, sex, BMI, tumor diameter, tumor location (descending and splenic flexure colon/ sigmoid colon/ middle and upper rectum), tumor height from anal verge, ASA grade, previous abdominal surgery, clinical pathologic stage, preoperative CEA. After matching, 132 patients in the NOSES group and 132 patients in the CL group were eligible for analysis.

RESULTS

Compared with CL group, NOSES group was associated with decreased postoperative maximum pain score (2.6±0.7 vs. 4.7±1.7, P=0.000), less additional analgesia required (6.8 vs. 34.8%, P=0.000), faster time to passage of flatus (2.3±0.6 days vs. 3.3±0.7 days, P=0.000), less wound infection (0.0 vs. 6.1%, P=0.007), and longer operative time (212.5±45.8 min vs. 178.0±43.4 min, P=0.000). No significant differences were observed in estimated blood loss, time to resume regular diet, postoperative hospital stay, conversion to open surgery or conventional minilaparotomy, total morbidity, readmission, mortality, pathologic outcomes, and Wexner incontinence score between groups. After a median follow-up of 63.0 months, the 5-year overall survival rates were 88.3 versus 85.0% (P=0.487), disease-free survival rates were 82.9 versus 83.6% (P=0.824), and the local recurrence rates were 4.4 versus 4.0% (P=0.667) in the NOSES and CL groups, respectively.

CONCLUSIONS

This study suggests that NOSES colectomy using a Cai tube for left-sided colorectal cancer is a safe and feasible option with better cosmetic results, less pain, faster recovery of gastrointestinal function, and comparable long-term clinical and oncologic outcomes to CL colectomy.

Neoadjuvant camrelizumab and apatinib combined with chemotherapy versus chemotherapy alone for locally advanced gastric cancer: a multicenter randomized phase 2 trial

Prospective evidence regarding the combination of programmed cell death (PD)-1 and angiogenesis inhibitors in treating locally advanced gastric cancer (LAGC) is limited. In this multicenter, randomized, phase 2 trial (NCT04195828), patients with gastric adenocarcinoma (clinical T2-4N + M0) were randomly assigned (1:1) to receive neoadjuvant camrelizumab and apatinib combined with nab-paclitaxel plus S-1 (CA-SAP) or chemotherapy SAP alone (SAP) for 3 cycles. The primary endpoint was the major pathological response (MPR), defined as <10% residual tumor cells in resection specimens. Secondary endpoints included R0 resection rate, radiologic response, safety, overall survival, and progression-free survival. The modified intention-to-treat population was analyzed (CA-SAP [n = 51] versus SAP [n = 53]). The trial has met pre-specified endpoints. CA-SAP was associated with a significantly higher MPR rate (33.3%) than SAP (17.0%, P = 0.044). The CA-SAP group had a significantly higher objective response rate (66.0% versus 43.4%, P = 0.017) and R0 resection rate (94.1% versus 81.1%, P = 0.042) than the SAP group. Nonsurgical grade 3-4 adverse events were observed in 17 patients (33.3%) in the CA-SAP group and 14 (26.4%) in the SAP group. Survival results were not reported due to immature data. Camrelizumab and apatinib combined with chemotherapy as a neoadjuvant regimen was tolerable and associated with favorable responses for LAGC.

[Comparison between laparoscopic-assisted natural orifice specimen extraction surgery and conventional laparoscopic surgery for left colorectal cancer: 5-year follow-up results of a randomized controlled study]

Objective: To evaluate the long-term efficacy of laparoscopic-assisted natural orifice specimen extraction surgery (NOSES) colectomy using Cai tube for treating left-sided colorectal cancer. Methods: This was a randomized controlled trial. Inclusion criteria were as follows: preoperative pathological diagnosis of left-sided colorectal adenocarcinoma (rectal, sigmoid colon, descending colon, or left transverse colon cancer with the caudad margin ≥8 cm from the anal margin); preoperative abdominal and pelvic computed tomography (or magnetic resonance imaging) showing maximum tumor diameter <4.5 cm; and BMI <30 kg/m2. Patients with synchronous multiple primary cancers or recurrent cancers, a history of neoadjuvant chemoradiotherapy, preoperative evidence of significant local infiltration, distant metastasis, or complications such as intestinal obstruction and intestinal perforation, or who were not otherwise considered suitable for laparoscopic surgery were excluded. A random number table was used to randomize sequential patients to NOSES surgery using Cai tube (non-assisted incision anal sleeve: patent number ZL201410168748.2) (NOSES group) or traditional laparoscopic-assisted surgery (CLS group). Relevant clinical data of the two groups of patients were analyzed, the main outcomes being disease-free survival, overall survival, overall recurrence rate, and local recurrence rate 5 years after surgery. Results: Patients in both study groups completed the surgery successfully with no requirement for additional surgery. After mean 70 (7-83) months postoperative follow-up, the 5-year overall postoperative survival in the NOSES and CLS groups was 90.0% and 83.3%, respectively (P=0.455); disease free survival was 90.0% and 83.3%, respectively (P=0.455); overall recurrence rate 6.6% and 10.0%, respectively (P=0.625); and local recurrence rate both were 3.3% (P=0.990), respectively. None of these differences was statistically significant. Conclusions: NOSES and CLS have similar long-term efficacy, and NOSES deserves to be used in clinical practice.

CXCR4 Expressed by Tumor-Infiltrating B Cells in Gastric Cancer Related to Survival in the Tumor Microenvironment: An Analysis Combining Single-Cell RNA Sequencing with Bulk RNA Sequencing

According to the World Health Organization (WHO), gastric cancer (GC) is the fourth leading cause of tumor-related mortality globally and one of the most prevalent malignant tumors. To better understand the role of tumor-infiltrating B cells (TIBs) in GC, this work used single-cell RNA sequencing (scRNA-Seq) and bulk RNA sequencing (bulk RNA-Seq) data to identify candidate hub genes. Both scRNA-Seq and bulk RNA-Seq data for stomach adenocarcinoma (STAD) were obtained from the GEO and TCGA databases, respectively. Using scRNA-seq data, the FindNeighbors and FindClusters tools were used to group the cells into distinct groups. Immune cell clusters were sought in the massive RNA-seq expression matrix using the single-sample gene set enrichment analysis (ssGSEA). The expression profiles were used in Weighted Gene Coexpression Network Analysis (WGCNA) to build TCGA's gene coexpression networks. Next, univariate Cox regression, LASSO regression, and Kaplan-Meier analyses were used to identify hub genes in scRNA-seq data from sequential B-cell analyses. Finally, we examined the correlation between the hub genes and TIBs utilizing the TISIDB database. We confirmed the immune-related markers in clinical validation samples using reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). 15 cell clusters were classified in the scRNA-seq database. According to the WGCNA findings, the green module is most associated with cancer and B cells. The intersection of 12 genes in two separate datasets (scRNA and bulk) was attained for further analysis. However, survival studies revealed that increased C-X-C motif chemokine receptor 4 (CXCR4) expression was linked to worse overall survival. CXCR4 expression is correlated with active, immature, and memory B cells in STAD were identified. Finally, RT-PCR and IHC assays verified that in GC, CXCR4 is overexpressed, and its expression level correlates with TIBs. We used scRNA-Seq and bulk RNA-Seq to study STAD's cellular composition. We found that CXCR4 is highly expressed by TIBs in GC, suggesting that it may serve as a hub gene for these cells and a starting point for future research into the molecular mechanisms by which these immune cells gain access to tumors and potentially identify therapeutic targets.

[Specimen extraction through natural orifices with Cai tubes in gastrointestinal surgery: a single-institute series of 234 cases]

Objective: To investigate the feasibility of Cai tube-assisted natural orifice specimen extraction surgery (NOSES) in gastrointestinal surgery. Methods: This was a descriptive case-series study. Inclusion criteria: (1) colorectal or gastric cancer diagnosed by preoperative pathological examination or redundant sigmoid or transverse colon detected by barium enema; (2) indications for laparoscopic surgery; (3) body mass index <30 kg/m² (transanal surgery) and 35 kg/m² (transvaginal surgery); (4) no vaginal stenosis or adhesions in female patients undergoing transvaginal specimen extraction; and (5) patients with redundant colon aged 18-70 years and a history of intractable constipation for more than 10 years. Exclusion criteria: (1) colorectal cancer with intestinal perforation or obstruction, or gastric cancer with gastric perforation, gastric hemorrhage, or pyloric obstruction; (2) simultaneous resection of lung, bone, or liver metastases ; (3) history of major abdominal surgery or intestinal adhesions; and (4) incomplete clinical data. From January 2014 to October 2022, 209 patients with gastrointestinal tumors and 25 with redundant colons who met the above criteria were treated by NOSES utilizing a Cai tube (China invention patent number:ZL201410168748.2) in the Department of Gastrointestinal Surgery, Zhongshan Hospital, Xiamen University. The procedures included eversion and pull-out NOSES radical resection in 14 patients with middle and low rectal cancer, NOSES radical left hemicolectomy in 171 patients with left-sided colorectal cancer, NOSES radical right hemicolectomy in 12 patients with right-sided colon cancer, NOSES systematic mesogastric resection in 12 patients with gastric cancer, and NOSES subtotal colectomy in 25 patients with redundant colons. All specimens were collected by using an in-house-made anal cannula (Cai tube) with no auxiliary incisions. The primary outcomes included 1-year recurrence-free survival (RFS) and postoperative complications. Results: Among 234 patients, 116 were male and 118 were female. The mean age was (56.6±10.9) years. NOSES was successfully completed in all patients without conversion to open surgery or procedure-related death. The negative rate of circumferential resection margin was 98.8% (169/171) with both two positive cases having left-sided colorectal cancer. Postoperative complications occurred in 37 patients (15.8%), including 11 cases (4.7%) of anastomotic leakage, 3 cases(1.3%) of anastomotic bleeding, 2 cases (0.9%) of intraperitoneal bleeding, 4 cases (1.7%) of abdominal infection, and 8 cases (3.4%) of pulmonary infection. Reoperations were required in 7 patients (3.0%), all of whom consented to creation of an ileostomy after anastomotic leakage. The total readmission rate within 30 days after surgery was 0.9% (2/234). After a follow-up of (18.3±3.6) months, the 1-year RFS was 94.7%. Five of 209 patients (2.4%) with gastrointestinal tumors had local recurrence, all of which was anastomotic recurrence. Sixteen patients (7.7%) developed distant metastases, including liver metastases(n=8), lung metastases(n=6), and bone metastases (n=2). Conclusion: NOSES assisted by Cai tube is feasible and safe in radical resection of gastrointestinal tumors and subtotal colectomy for redundant colon.

Clinical outcomes of laparoscopic-assisted natural orifice specimen extraction colectomy using a Cai tube for left-sided colon cancer: a prospective randomized trial

BACKGROUND

The role of laparoscopic-assisted natural orifice specimen extraction (LA-NOSE) colectomy in the treatment of left-sided colon cancer has not been well defined, and there remains confusion about how to conveniently exteriorize specimens through natural orifices. Therefore, we introduced a homemade invention, the Cai tube, to facilitate the extraction of specimens and compared the clinical outcomes of LA-NOSE with conventional laparoscopic (CL) colectomy for left-sided colon cancer.

METHODS

From March 2015 to August 2017, patients with left-sided colon cancer were randomly divided into LA-NOSE and CL groups. Specimens were extracted through the anus with the help of a Cai tube (Patent Number: ZL201410168748.2) in the LA-NOSE group. The primary outcome measure was postoperative pain. Secondary outcomes were the duration of operation, postoperative recovery, surgical morbidity, pathological quality of the specimen, and long-term outcomes, including 3-year overall survival, disease-free survival, local recurrence, and overall recurrence.

RESULTS

A total of 60 patients (30 per group) were recruited for this study. None of the patients required emergency conversion to conventional laparoscopic or open surgery during the operation. The postoperative maximum pain score was significantly lower in the LA-NOSE group (mean 2.5 vs. 5.1, P = 0.001), as was the additional analgesia requirement (mean 2/30 vs. 10/30, P = 0.021). Patients in the LA-NOSE group experienced a shorter first time to passage of flatus (mean 2.2 vs. 3.1 days, P = 0.026). All patients could control their defecation at 6 months after surgery. The comparison between the two groups showed no significant differences in the operative time, bleeding volume, postoperative hospital stay, surgical morbidity rates, number of lymph nodes harvested, or resection margin status. The mean follow-up was 48 months (range 7-59) and was similar in both groups. The results showed no differences in long-term outcomes between the two groups.

CONCLUSION

In the treatment of left-sided colon cancer, compared with conventional laparoscopic colectomy, LA-NOSE colectomy using the Cai tube exhibited lower postoperative pain, shorter recovery of gastrointestinal function, and similar long-term outcomes.

REGISTRATION NUMBER

ChiCTR-OOR-15007060 ( http://www.chictr.org.cn/ ).

Proteomic signatures of infiltrative gastric cancer by proteomic and bioinformatic analysis

BACKGROUND

Proteomic signatures of Ming's infiltrative gastric cancer (IGC) remain unknown.

AIM

To elucidate the molecular characteristics of IGC at the proteomics level.

METHODS

Twelve pairs of IGC and adjacent normal tissues were collected and their proteomes were analyzed by high performance liquid chromatography tandem mass spectrometry. The identified peptides were sequenced de novo and matched against the SwissProt database using Maxquant software. The differentially expressed proteins (DEPs) were screened using |log2(Fold change)| > 1 and P-adj < 0.01 as the thresholds. The expression levels of selected proteins were verified by Western blotting. The interaction network of the DEPs was constructed with the STRING database and visualized using Cytoscape with cytoHubba software. The DEPs were functionally annotated using clusterProfiler, STRING and DAVID for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. P < 0.05 was considered statistically significant.

RESULTS

A total of 7361 DEPs were identified, of which 94 were significantly up-regulated and 223 were significantly down-regulated in IGC relative to normal gastric tissues. The top 10 up-regulated proteins were MRTO4, BOP1, PES1, WDR12, BRIX1, NOP2, POLR1C, NOC2L, MYBBP1A and TSR1, and the top 10 down-regulated proteins were NDUFS8, NDUFS6, NDUFA8, NDUFA5, NDUFC2, NDUFB8, NDUFB5, NDUFB9, UQCRC2 and UQCRC1. The up-regulated proteins were enriched for 9 biological processes including DNA replication, ribosome biogenesis and initiation of DNA replication, and the cellular component MCM complex. Among the down-regulated proteins, 17 biological processes were enriched, including glucose metabolism, pyruvic acid metabolism and fatty acid β-oxidation. In addition, the mitochondrial inner membrane, mitochondrial matrix and mitochondrial proton transport ATP synthase complex were among the 6 enriched cellular components, and 11 molecular functions including reduced nicotinamide adenine dinucleotide dehydrogenase activity, acyl-CoA dehydrogenase activity and nicotinamide adenine dinucleotide binding were also enriched. The significant KEGG pathways for the up-regulated proteins were DNA replication, cell cycle and mismatch repair, whereas 18 pathways including oxidative phosphorylation, fatty acid degradation and phenylalanine metabolism were significantly enriched among the down-regulated proteins.

CONCLUSION

The proteins involved in cell cycle regulation, DNA replication and mismatch repair, and metabolism were significantly altered in IGC, and the proteomic profile may enable the discovery of novel biomarkers.

Identification of Essential Tumor-Infiltrating Immune Cells and Relevant Genes in Left-Sided and Right-Sided Colon Cancers

Simple Summary

Differences in oncogenes between left-sided colon cancer and right-sided colon cancer have been reported in-depth. Tumor-infiltrating immune cells and relevant genes between left-sided and right-sided colon cancers are unclear. Bioinformatic analysis was used to identify these hub immune cells and relevant genes. Colon cancer outcomes are associated with changes in MDSC infiltration, and therefore LCP1, ITGB2, and IKZF1 may be novel targets for immunotherapy.

Abstract

Backgrounds: Colorectal cancer is the third most prevalent cancer worldwide. A right-sided colon cancer patient typically has a worse prognosis than one who has a left-sided colon cancer. There is an unclear understanding of how left-sided colon cancer differs from right-sided colon cancer in tumor-infiltrating immune cells (TIICs) and relevant genes. Methods: The Cancer Genome Atlas provided RNA-seq data and clinical information regarding colon adenocarcinoma. We conducted a single-sample gene set enrichment analysis (ssGSEA) to quantify the level of 24 immune cells infiltrating the tissues. Based on an analysis of univariate Cox regression, immune cell types associated with survival were identified. Weighted gene co-expression network analysis (WGCNA) was used to identify hub genes related to location and critical immune cells. Based on the Search Tool for the Retrieval of Interacting Genes (STRING), interaction potential was predicted among the hub genes. Hub genes that influence outcomes through immune infiltration were identified using the least absolute shrinkage and selection operator (LASSO). Then, we used the TISIDB database (a repository portal for tumor–immune system interactions) to validate the correlation between hub genes and immune cell infiltration. Finally, immunohistochemical assays were conducted to determine the levels of proteins expressed by critical TIICs and cancer cells. Results: Colon cancers on the right side of the body had higher levels of myeloid-derived suppressor cells (MDSCs) than on the left side. There were three key genes: LCP1, ITGB2, and IKZF1. It was found that their expression was linked to poor prognosis and an increased level of MDSC infiltration. An immunohistochemical study confirmed these findings. Conclusions: There is a higher rate of MDSC infiltration in right-sided colon cancer when compared with left-sided colon cancer. COAD outcomes are associated with changes in MDSC infiltration, and therefore LCP1, ITGB2, and IKZF1 may be novel targets for immunotherapy.

[Comparison between laparoscopic-assisted natural orifice specimen extraction surgery and conventional laparoscopic surgery for left colorectal cancer: a randomized controlled study with 3-year follow-up results]

Objective: To evaluate the mid-term efficacy of laparoscopic-assisted natural orifice specimen extraction surgery (NOSES) colectomy using the Cai tube in the treatment of left colorectal cancer. Methods: A prospective randomized control trial (China Clinical Trials Registration Number: ChiCTR-OOR-15007060) was performed. Sixty patients with left colorectal cancer at Department of Gastrointestinal Surgery of Zhongshan Hospital from September 2015 to August 2017 were prospectively enrolled. Case inclusion criteria: (1) left colorectal adenocarcinoma (rectal cancer with distance ≥ 8 cm from tumor low margin to anal edge, sigmoid colon cancer, descending colon cancer and left transverse colon cancer) confirmed by preoperative pathology; (2) satisfactory conditions of conventional laparoscopic surgery; (3) maximum diameter of the tumor < 4.5 cm confirmed by preoperative abdominal and pelvic CT or MRI; (4) BMI < 30 kg/m². Case exclusion criteria: (1) benign lesions, mucinous adenocarcinoma, signet-ring cell carcinoma and other special pathological types of tumors confirmed by preoperative pathological examination; (2) multiple or recurrent cancers; (3) with a history of neoadjuvant chemoradiotherapy; (4) obvious regional infiltration or distant metastasis indicated by preoperative imaging examination; (5) intestinal obstruction, intestinal perforation, etc. Participants were randomly assigned to NOSES group (using the Cai tube) and conventional laparoscopy (CL) group by random number table method. Clinical data between two groups were compared and analyzed, including perioperative conditions, tumor exfoliation cell detection and bacterial culture results of intraperitoneal lavage fluid, postoperative complications (Clavien-Dindo grading), postoperative pain [visual simulation scoring (VAS) assessment], anal function (Kirwan anal function grading assessment), and postoperative 3-year disease-free survival (DFS), overall survival (OS), overall recurrence rate, and local recurrence rate. Results: A total of 60 patients were enrolled, with 30 in the NOSES group and 30 in the CL group. All the patients in the NOSES group successfully completed operation with Cai tube. Baseline data between the two groups were not significantly different (all P>0.05). There were no statistically significant differences between two groups in conversion rate to open surgery, number of lymph node harivested, proximal and distal resection margin of tumor, negative rate of circumferential margin, operation time, blood loss, inflammatory indexes, postoperative anal function, postoperative hospital stay, hospitalization cost, morbidity of postoperative complications (Clavien-Dindo grade II or above) (all P>0.05). Compared to the CL group, the NOSES group had lower maximum postoperative VAS score (2.5±0.3 vs. 5.1±0.4, t=3.187, P<0.01), and fewer use of additional postoperative analgesia [6.7% (2/30) vs. 33.3% (10/30),χ²=6.670, P=0.02]. The postoperative time to gas passage was shorter in the NOSES group [(2.2±1.4) days vs. (3.1±1.2) days,P=0.026]. No tumor cells and bacterial contamination were found in abdominal lavage fluid before and after operation in either group. The anal function at postoperative 3-month of all the patients in the NOSES group was Kirwan grade I to II, while in the CL group, anal function of 2 cases (6.7%) was Kirwan grade III, and of 28 cases was also Kirwan grade I to II, whose difference was not statistically significant (P>0.05). In the NOSES group and the CL group, 3-year DFS was 96.7% and 83.3% (P=0.090), OS was 100% and 90% (P=0.096), overall recurrence rate was 3.3% and 10.0% (P=0.166), and local recurrence rate was 3.3% and 3.3% (P=0.999), respectively, whose differences were not statistically significant (all P>0.05). Conclusions: In the treatment of left colorectal cancer, compared with conventional laparoscopic colectomy, NOSES colectomy using Cai tube exhibits less scar, less postoperative pain, shorter recovery of gastrointestinal function, and similar mid-term outcomes. Given proper surgical indications, the surgical procedure is safe and feasible.

Laparoscopic-Assisted Natural Orifice Specimen Extraction Gastrectomy Using an Auxiliary Incision-free Tube for Gastric Cancer

BACKGROUND

Laparoscopic-assisted natural orifice specimen extraction (LA-NOSE) gastrectomy effectively avoids the need for an abdominal incision, unlike conventional laparoscopic gastrectomy. In this study, we documented our experience with LA-NOSE gastrectomy using an auxiliary incision-free tube (Cai tube, a homemade invention: ZL201410168748.2) in 9 gastric cancer patients and summarized the clinical results.

METHODS

From July 2018 to June 2020, a total of 9 patients with gastric cancer were recruited for this study. LA-NOSE gastrectomy (subtotal or total) using the auxiliary incision-free tube and D₂ lymph node dissection were performed. Specimens were extracted through the anterior wall of the upper rectum in 4 male patients and the posterior fornix of the vagina in 5 female patients using the auxiliary incision-free tube.

RESULTS

All 9 patients underwent successful laparoscopic gastrectomy with NOSE using the auxiliary incision-free tube. No perioperative death, re-admission within 60 days post operation, natural orifice wound infection or tumor implantation was observed. The mean operating time was 365.3±41.7 min, and the mean estimated blood loss was 87.8±39.3 ml. The mean duration of hospital stay was 11.3±1.2 days, while the mean maximum pain score (visual analogue score, VAS) was 2.3±0.9 on postoperative day (POD) 1, and the mean time to ambulation was 1.3±0.5 days. The 60-day postoperative morbidity rate was 11.1% (1/9). After a mean follow-up of 14.7±9.6 months, there was no transrectal or transvaginal access-site recurrence, no anterior rectectomy or posterior fornix colpotomy-related complications, and no local recurrence or distant metastasis.

CONCLUSIONS

Our preliminary experience indicates that this new technique, LA-NOSE gastrectomy using the auxiliary incision-free tube, is feasible for selected patients with gastric cancer.

[Antibiotic resistance and virulence characteristics analysis of a carbapenem-resistant hypervirulent Klebsiella pneumoniae]

Objective: To characterize the antibiotic resistance and virulence in a carbapenem-resistant Klebsiella pneumoniae (CRKP). Methods: A CRKP (designated K. pneumoniae C35) was isolated from a stool sample. The minimal inhibitory concentrations of antimicrobial agents were determined using the broth microdilution method. Whole-genome sequencing and genome analysis were performed to identify the antibiotic resistance and virulence genes. The genetic relationship among K. pneumoniae C35 and other CRKP isolates from our hospital was analyzed by single nucleotide polymorphism (SNP) typing of core genomes. Conjugation experiments were carried out by filter mating to evaluate the transferability and efficiency of resistance genes. The virulence phenotype was determined by Galleria mellonella infection model. Results: K. pneumoniae C35 exhibited resistance to the majority of tested antibiotics, especially carbapenems, sulbactam, and polymyxins. SNP typing showed that K. pneumoniae C35 shared a high degree of sequence homology with several CRKP isolates from different wards. This ST11 CRKP carried 13 resistance genes, including bla_KPC-2, bla_CTX-M-199, mcr-1, and tet(A) variant. bla_KPC-2 gene was located on an IncFⅡ plasmid with>69 800 bp in size, bla_CTX-M-199 and mcr-1 genes were located on an IncI2 plasmid (>64 800 bp), and tet(A) variant was located on an unknown Inc-type plasmid (83 628bp). All these three plasmids were conjugative. K. pneumoniae C35 was found to harbor rmpA, rmpA2, and iucABCD aerobactin-related genes, and was considered to be classic carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP). The virulence potential of this strain was confirmed in a Galleria mellonella infection model. The survival rate of the larvae injected with strain C35 at 48 h after infection was significantly lower than that of negative control strain (16.7% vs 80.0%). Conclusion: Multiple conjugative plasmids are identified in a faecal CR-hvKP. The IncI2 plasmid co-carrying both bla_CTX-M-199 and mcr-1 genes is firstly identified in CR-hvKP. The emergence of such strain should be alerted and active surveillance is warranted.

Effectiveness and Safety of Apatinib Plus Chemotherapy as Neoadjuvant Treatment for Locally Advanced Gastric Cancer: A Nonrandomized Controlled Trial

Importance

Apatinib is a novel treatment option for chemotherapy-refractory advanced gastric cancer (GC), but it has not been evaluated in patients with locally advanced GC.

Objective

To investigate the effectiveness and safety of apatinib combined with S-1 plus oxaliplatin (SOX) as a neoadjuvant treatment for locally advanced GC.

Design, Setting, and Participants

This multicenter, prospective, single-group, open-label, phase 2 nonrandomized controlled trial was conducted in 10 centers in southern China. Patients with M0 and either clinical T2 to T4 or N+ disease were enrolled between July 1, 2017, and June 30, 2019. Statistical analysis was performed from December 1, 2019, to January 31, 2020.

Interventions

Eligible patients received apatinib (500 mg orally once daily on days 1 to 21 and discontinued in the last cycle) plus SOX (S-1: 40-60 mg orally twice daily on days 1 to 14; oxaliplatin: 130 mg/m2 intravenously on day 1) every 3 weeks for 2 to 5 cycles. A D2 gastrectomy was performed 2 to 4 weeks after the last cycle.

Main Outcomes and Measures

The primary end point was R0 resection rate. Secondary end points were the response rate, toxic effects, and surgical outcome.

Results

A total of 48 patients (mean [SD] age, 63.2 [8.2] years; 37 men [77.1%]) were enrolled in this study. Forty patients underwent surgery (38 had gastrectomy, and 2 had exploratory laparotomy), with an R0 resection rate of 75.0% (95% CI, 60.4%-86.4%). The radiologic response rate was 75.0%, and T downstaging was observed in 16 of 44 patients (36.4%). The pathological response rate was 54.2% (95% CI, 39.2%-68.6%); moreover, this rate was significantly higher in patients who achieved a radiologic response compared with those who did not (12 [80.0%] vs 1 [20.0%]; P = .03) and in those who had an Eastern Cooperative Oncology Group Performance Status score of 0 (20 [76.9%] vs 10 [45.5%]; P = .03) or had tumors located in the upper one-third of the stomach (16 [61.5%] vs 7 [31.8%]; P = .04). Patients who achieved a pathological response (vs those who did not) had significantly less blood loss (median [range]: 60 [10-200] mL vs 80 [20-300] mL; P = .04) and significantly more lymph nodes harvested (median [range]: 40 [24-67] vs 32 [19-51]; P = .04) during surgery. Postoperative complications were observed in 7 of 38 patients (18.4%). Grade 3 toxic effects occurred in 16 of 48 patients (33.3%), and no grade 4 toxic effects or preoperative deaths were observed.

Conclusions and Relevance

This nonrandomized controlled trial found that apatinib combined with SOX was effective and had an acceptable safety profile as a neoadjuvant treatment for locally advanced GC. A large-scale randomized clinical trial may be needed to confirm the findings.

Trial Registration

ClinicalTrials.gov Identifier: NCT03192735.

International consensus on natural orifice specimen extraction surgery (NOSES) for gastric cancer (2019)

At present, natural orifice specimen extraction surgery (NOSES) has attracted more and more attention worldwide, because of its great advantages including minimal cutaneous trauma and post-operative pain, fast post-operative recovery, short hospital stay, and positive psychological impact. However, NOSES for the treatment of gastric cancer (GC) is still in its infancy, and there is great potential to improve its theoretical system and clinical practice. Especially, several key points including oncological outcomes, bacteriological concerns, indication selection, and standardized surgical procedures are raised with this innovative technique. Therefore, it is necessary to achieve an international consensus to regulate the implementation of GC-NOSES, which is of great significance for healthy and orderly development of NOSES worldwide.

International consensus on natural orifice specimen extraction surgery (NOSES) for colorectal cancer

In recent years, natural orifice specimen extraction surgery (NOSES) in the treatment of colorectal cancer has attracted widespread attention. The potential benefits of NOSES including reduction in postoperative pain and wound complications, less use of postoperative analgesic, faster recovery of bowel function, shorter length of hospital stay, better cosmetic and psychological effect have been described in colorectal surgery. Despite significant decrease in surgical trauma of NOSES have been observed, the potential pitfalls of this technique have been demonstrated. Particularly, several issues including bacteriological concerns, oncological outcomes and patient selection are raised with this new technique. Therefore, it is urgent and necessary to reach a consensus as an industry guideline to standardize the implementation of NOSES in colorectal surgery. After three rounds of discussion by all members of the International Alliance of NOSES, the consensus is finally completed, which is also of great significance to the long-term progress of NOSES worldwide.

Tumor-originated exosomal lncUEGC1 as a circulating biomarker for early-stage gastric cancer

Conventional tumor markers for non-invasive diagnosis of gastric cancer (GC) exhibit insufficient sensitivity and specificity to facilitate detection of early gastric cancer (EGC). We aimed to identify EGC-specific exosomal lncRNA biomarkers that are highly sensitive and stable for the non-invasive diagnosis of EGC. Hence, in the present study, exosomes from the plasma of five healthy individuals and ten stage I GC patients and from culture media of four human primary stomach epithelial cells and four gastric cancer cells (GCCs) were isolated. Exosomal RNA profiling was performed using RNA sequencing to identify EGC-specific exosomal lncRNAs. A total of 79 and 285 exosomal RNAs were expressed at significantly higher levels in stage I GC patients and GCCs, respectively, than that in normal controls. Through combinational analysis of the RNA sequencing results, we found two EGC-specific exosomal lncRNAs, lncUEGC1 and lncUEGC2, which were further confirmed to be remarkably up-regulated in exosomes derived from EGC patients and GCCs. Furthermore, stability testing demonstrates that almost all the plasma lncUEGC1 was encapsulated within exosomes and thus protected from RNase degradation. The diagnostic accuracy of exosomal lncUEGC1 was evaluated, and lncUEGC1 exhibited AUC values of 0.8760 and 0.8406 in discriminating EGC patients from healthy individuals and those with premalignant chronic atrophic gastritis, respectively, which was higher than the diagnostic accuracy of carcinoembryonic antigen. Consequently, exosomal lncUEGC1 may be promising in the development of highly sensitive, stable, and non-invasive biomarkers for EGC diagnosis.

Laparoscopic-Assisted Natural Orifice Specimen Extraction Radical Descending Colectomy Using a Cai Tube

AIM

To overcome the technical difficulty of exteriorizing a specimen through the descending colon stump, we applied laparoscopic-assisted natural orifice specimen extraction (LA-NOSE) using a Cai tube.

METHODS

From April 2014 to February 2015, we successfully performed total laparoscopic radical surgery with LA-NOSE in six patients with descending colon lesions. The time of operation, blood loss amount, lymph nodes harvested, postoperative recovery, postoperative complications and follow-up were observed.

RESULTS

Total laparoscopic dissection and anastomosis with natural orifice removal using a Cai tube was successful in all 6 patients; no deaths, anastomotic bleeding, fistulas, infections, or any other complications were recorded. The median operating time was 327.7 ± 73.4 min, and the estimated blood loss was 66.7 ± 69.2 mL. The mean number of lymph nodes harvested was 15.7 ± 4.4. Recovery of gastrointestinal function ranged from 2 to 4 days after the operation. The mean length of postoperative hospital stay was 12.3 ± 3.2 days. The six cases were followed up for 6-16 (12.5 ± 3.6) months, and all patients avoided auxiliary incision which demonstrated potential cosmetic advantages and uneventful recovery with no additional complications or cancer recurrence.

CONCLUSION

In this pilot study of six patients, LA-NOSE radical descending colectomy using a Cai tube was feasible and safe.

N-Myc-Interacting Protein Negatively Regulates TNF-α-Induced NF-κB Transcriptional Activity by Sequestering NF-κB/p65 in the Cytoplasm

NF-κB is a major regulator of gene transcription involved in immune, inflammation, apoptosis and stress responses. However, the regulation of NF-κB is not completely understood. Here, we report that the N-Myc and STATs Interactor (NMI), an IFN-inducible protein, is an important negative regulator of NF-κB activity. We found that NMI negatively regulates TNF-α-induced IL-6 and IL-1β production in HeLa cells. Overexpression of NMI inhibits NF-κB transcriptional activity, in contrast, depletion of NMI by shRNA increases NF-κB transcriptional activity. Mechanistically, NMI associates with NF-κB/p65 and inhibits NF-κB/p65 nuclear translocation and thereby negatively regulates NF-κB/p65 transcriptional activity. Taken together, our results demonstrate that NMI modulates the NF-κB signaling pathway by sequestering NF-κB/p65 in the cytoplasm, resulting in reduced IL-6 and IL-1β production after TNF-α stimulation. Treatment with IFNα in the presence of NMI leads to increased apoptosis in tumor cells. These findings reveal a novel mechanism by which NMI regulates NF-κB activity.

p21-activated protein kinase 1 induces the invasion of gastric cancer cells through c-Jun NH2-terminal kinase-mediated activation of matrix metalloproteinase-2

Gastric cancer (GC) is one of the most common malignancies worldwide. The prognosis of GC is poor, mostly due to widespread metastasis. p21-activated kinase 1 (Pak1), the best characterized member of an evolutionarily conserved family of serine/threonine kinases, plays an important role in the regulation of cell morphogenesis, motility, mitosis and angiogenesis. By qRT-PCR and Gelatin zymograph assay, we demonstrated in the present study that stable overexpression of Pak1 induced matrix metalloproteinase (MMP)-2 mRNA expression and activity in the human MKN45 GC cell line. Conversely, knockdown of endogenous Pak1 expression by small interfering RNA (siRNA) decreased MMP-2 mRNA expression and activity in the MKN45 GC cells. Activation of c-Jun N-terminal kinase (JNK) was required for Pak1-induced upregulation of MMP-2 mRNA level and activity. Moreover, upregulation of MMP-2 by Pak1 via the JNK pathway notably promoted the invasion of MKN45 GC cells. Overexpression of MMP-2 mRNA was once again confirmed to be associated with GC metastasis. In conclusion, our results demonstrated for the first time that Pak1 stimulated MMP-2 mRNA expression and activity in MKN45 GC cells. The JNK signaling pathway was involved in Pak1 modulation of MMP-2, which was important for MKN45 GC cell invasiveness.

Yes-associated protein/TEA domain family member and hepatocyte nuclear factor 4-alpha (HNF4α) repress reciprocally to regulate hepatocarcinogenesis in rats and mice

Great progress has been achieved in the study of Hippo signaling in regulating tumorigenesis; however, the downstream molecular events that mediate this process have not been completely defined. Moreover, regulation of Hippo signaling during tumorigenesis in hepatocellular carcinoma (HCC) remains largely unknown. In the present study, we systematically investigated the relationship between Yes-associated protein/TEA domain family member (YAP-TEAD) and hepatocyte nuclear factor 4-alpha (HNF4α) in the hepatocarcinogenesis of HCC cells. Our results indicated that HNF4α expression was negatively regulated by YAP1 in HCC cells by a ubiquitin proteasome pathway. By contrast, HNF4α was found to directly associate with TEAD4 to compete with YAP1 for binding to TEAD4, thus inhibiting the transcriptional activity of YAP-TEAD and expression of their target genes. Moreover, overexpression of HNF4α was found to significantly compromise YAP-TEAD-induced HCC cell proliferation and stem cell expansion. Finally, we documented the regulatory mechanism between YAP-TEAD and HNF4α in rat and mouse tumor models, which confirmed our in vitro results.

CONCLUSION

There is a double-negative feedback mechanism that controls TEAD-YAP and HNF4α expression in vitro and in vivo, thereby regulating cellular proliferation and differentiation. Given that YAP acts as a dominant oncogene in HCC and plays a crucial role in stem cell homeostasis and tissue regeneration, manipulating the interaction between YAP, TEADs, and HNF4α may provide a new approach for HCC treatment and regenerative medicine. (Hepatology 2017;65:1206-1221).

miR-15a-3p and miR-16-1-3p Negatively Regulate Twist1 to Repress Gastric Cancer Cell Invasion and Metastasis

MicroRNAs are a novel class of gene regulators that function as oncogenes or tumor suppressors. In our current study, we investigated the role of miR-15a-3p and miR-16-1-3p in the regulation of Twist1 expression and EMT process. Our bioinformatics analysis suggested that on the 3' UTR of Twist1, there are two conserved miRNA recognition sites for miR-15a-3p and miR-16-1-3p respectively. Interestingly, overexpression of miR-15a-3p and miR-16-1-3p significantly suppressed the activity of luciferase reporter containing Twist1-3' UTR, reduced mRNA and protein level of EMT related genes such as TWIST1, N-cadherin, α-SMA and Fibronectin, and repressed MMP9 and MMP2 activity, as well as cell migration and invasion. Conversely, inhibition of miR-15a-3p and miR-16-1-3p significantly increased TWIST1, N-cadherin, α-SMA and Fibronectin protein expression. In addition, Twist1 co-transfection significantly ameliorated the loss of cell migration and invasion. Moreover, overexpression of miR-15a-3p and miR-16-1-3p dramatically suppressed the ability of BGC823 cells to form colonies in vitro and develop tumors in vivo in nude mice. Finally, qPCR and Western blot analysis showed that miR-15a-3p and miR-16-1-3p were significantly reduced in clinical gastric cancer tissue, whereas Twist1 mRNA and protein were significantly up-regulated, suggesting that this aberrant down-regulation of miR-15a-3p and miR-16-1-3p might be associated with the abnormal regulation of Twist1 and the EMT process in gastric cancer development. Our results help to elucidate a novel and important mechanism for the regulation of Twist1 in the development of cancer.

Establishment and characterization of an expanding-type gastric cancer cell line by Ming's classification

According to Ming's classification, gastric cancer (GC) can be divided into two types: expanding and infiltrative. The two types are readily recognizable by histology: expanding carcinomas grow en masse and by expansion, resulting in the formation of discrete tumour nodules, whereas in infiltrative carcinoma, tumour cells invade individually. Both types show varying degrees of cell maturation. The two types of carcinomas have vastly different pathological and clinical features. However, little is known concerning the mechanisms underlying these differences since no GC cell line models are available. For comprehensive and insightful analyses of mechanisms and treatment methods, new cell lines derived from expanding- and infiltrative-type gastric tumours are urgently needed. In the present study, we established an expanding-type GC cell line from a 72-year-old male patient. Different in vitro and in vivo methods were used to characterize the phenotypes of this cell line. This GC cell line was named XGC-2 and had an ~60 h doubling time. The cell line displayed strong colony formation and tumourigenicity in nude mice and had complicated chromosomal abnormalities. XGC-2 cells showed some markers of epithelial-to-mesenchymal transition (EMT), with decreased E-cadherin expression levels and increased vimentin expression levels. The XGC-2 cell line may be useful for future studies of GC development, progression, metastasis and therapy.

Protection of a novel epitope-RNA VLP double-effective VLP vaccine for foot-and-mouth disease

Foot and mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals. Previously, we found that the epitope peptide EP_141-160 displayed on virus-like particles (VLP) for use as a vaccine showed high immunoreactivity and conferred partially effective protection to animals. In this study, we first combined antisense RNA with VLP as a vaccine against the foot-and-mouth disease virus (FMDV) by using a prokaryotic co-expression system. The antisense RNA against the 3D genes of FMDV was packaged into VLP with EP_141-160 presented on the surface. ELISA and Western blotting proved that the epitope-RNA VLP eliciting an immune response to FMDV in mice. Furthermore, the potency of the vaccine was tested in mice and guinea pigs. The results indicated that the epitope-RNA VLP vaccine protected 40% of suckling mice and 85% (17/20) of guinea pigs from FMDV. Based on the experimental data, the epitope-RNA VLP vaccine should have value in exploring and developing vaccines against FMDV in the future.

N-Myc-interacting protein (NMI) negatively regulates epithelial-mesenchymal transition by inhibiting the acetylation of NF-κB/p65

The epithelial-mesenchymal transition (EMT) plays an essential role in embryonic development, wound healing, tissue regeneration, organ fibrosis, and tumor progression. However, the mechanisms underlying this process are poorly understood. Many signaling pathways, including the NF-κB signaling pathway, trigger EMT during development and differentiation. In the present study, we report that N-Myc interactor (NMI) inhibits EMT progression by suppressing transcriptional activities of NF-κB in human gastric cancer cells. We show that the expression of NMI is significantly reduced in invasive gastric cancer cells and gastric cancer tissues. Overexpression of NMI inhibited cell migration and invasion, and this inhibition was enhanced after TNF-α stimulation. Tumorigenicity assay in nude mice support the notion that NMI inhibits EMT in cancer cells. Mechanistically, NMI promotes the interaction between NF-κB/p65 and histone deacetylases (HDACs) and inhibits the acetylation and transcriptional activity of p65. The expression of p65 rescues NMI-mediated inhibition of EMT and the inhibition of the acetylation of p65 mediated by NMI is HDACs-dependent. Taken together, these findings suggest that NMI can suppress tumor invasion and metastasis by inhibiting NF-κB pathways, providing an alternative mechanism for EMT inhibition in stomach neoplasm.

Dynamic metabolic change is indicative of inflammation-induced transformation of hepatic cells

The observation that prolonged inflammation plays a causative role in cancer development has been well documented. However, an incremental process that leads from healthy to malignant phenotypes has not yet been described. Experimentally induced hepatocellular carcinoma is considered one of the representative laboratory models for studying this process. Hepatic exposure to viral infection or toxic reagents leads to chronic inflammation and gradual transformation into hepatocellular carcinoma. Here we present metabolomic profiles of hepatic cells at different stages during inflammation-induced cellular transformation by N-nitrosodiethylamine. Using gas chromatography-mass spectrometry, we quantitatively assessed the changes in cellular metabolites during the transformation process in hepatitis and liver cirrhosis. Further pathway analysis of the differentially expressed metabolites showed that carbohydrate metabolism and lipid metabolism were greatly altered in hepatitis and liver cirrhosis, respectively. Additionally, the enhanced inflammation in cirrhosis was associated with a shift from carbohydrate metabolism to lipid and amino acid metabolism. Among the differentially expressed metabolites found in diseased mouse livers, d-glucose and d-mannitol showed the most significant changes, highlighting them as potential early-diagnostic biomarkers of hepatocellular carcinoma development. Taken together, these investigations into the dynamic metabolic changes that occur during the precancerous stages of hepatocellular carcinoma add to and refine understanding of how chronic inflammation ultimately leads to cancer. Furthermore, the findings set the stage for identifying metabolites that may serve as early-diagnostic indicators of these unfolding events.

Correlation of expression of microRNA miR-21 with prognostic characteristics in gastric cancer

e14629

Background: MicroRNAs may play an important role in earlt stage gastric cancer. Methods: We studied the expression of MicroRNAs in gastric cancer to understand the expression characteristics of one of the key MicroRNAs miR-21 using 65 cases of early-stage gastric cancer identified from our cancer center records between October 2007 and March 2010. First, we used an MicroRNA array (miRCURY LNA Array) that contained 1,348 known probes and compared the expression profile of these MicroRNAs in six cases of gastric cancer specimen with their surrounding normal tissues. We then studied the expression of miR-21 and correlated it with the histologic characteristics of the 65 cases by RT-PCR. Results: The expression of seven MicroRNAs (miR-374b*, miRPlus-E1212, miR-338-5p, miR-297, miR-21, miR-135b, and miR-18a) was significantly up-regulated, while nine MicroRNAs (miR-29b-2*, miR-1260, miRPlus-E1241, miR-S1-5p, miR-148a, miR-29c, miR-647, miR-196b*, ebv-miR-BART5) significantly down-regulated. Because miR-21 was highly overexpressed in gastric cancer compared to its normal surrounding tissue, we next studied if the expression of miR-21 in sixty-five cases of gastric cancer was associated with clinical and histologic characteristics of early stage gastric cancer. We found that the increased expression of miR-21 was correlated with poorly differentiated histology (high grade), T3-4 stage and nodal involvement. The average level of miR-21 expression was two to five folds higher in the cases that are poorly differentiated, T3-4 stage, or with lymph node involvement compared to the cases that were well or moderately differentiated, T1-2 stage or with negative nodal involvement. The high-grade gastric cancers were associated with the highest level of miR-21 compared to the surrounding normal tissues. These results suggest that miR-21 is a potential biological marker indicative of the aggressiveness nature of this malignancy. Conclusions: Our results demonstrate that expression of several MicroRNAs may play important roles in the development and progression of gastric cancer and the increased expression of miR-21 is associated with poor prognostic characteristics.

The orphan receptor TR3 suppresses intestinal tumorigenesis in mice by downregulating Wnt signalling

AIMS

Wnt signalling is involved in cellular homeostasis and development. Dysregulation of the Wnt signalling pathway has been linked to colorectal cancer. The orphan nuclear receptor TR3 plays important roles in proliferation and apoptosis. In this study, we investigated how TR3 suppresses intestinal tumorigenesis by regulating Wnt signalling.

METHODS

Intestinal polyps were quantified in Apc(min/+), Apc(min/+)/TR3(-/-) and Apc(min/+)/villin-TR3 mice. Wnt signalling activity was evaluated by assessing β-galactosidase activity in a BAT-Gal reporter strain. The TR3 agonist cytosporone B was used to evaluate the role of TR3 in intestinal tumorigenesis. Crosstalk between TR3 and β-catenin/TCF4 was analysed by molecular methods in colorectal cancer cells. The phosphorylation of TR3 by glycogen synthase kinase (GSK) 3β and the correlation between GSK3β activity and TR3 phosphorylation were evaluated in clinical samples and colorectal cancer cells.

RESULTS

TR3 was found to significantly suppress Wnt signalling activity and the proliferation of intestinal epithelial cells. Apc(min/+)/TR3(-/-) mice developed more intestinal polyps than Apc(min/+)/TR3(+/+) mice, whereas either transgenic overexpression of TR3 in the intestine or treatment with cytosporone B in Apc(min/+) mice significantly decreased intestinal tumour number. Mechanistically, TR3 disrupted the association of β-catenin and TCF4 on chromatin and facilitated the recruitment of transcriptional co-repressors to the promoters of Wnt signalling target genes. However, TR3 was phosphorylated by GSK3β in most clinical colorectal cancers, which attenuated the inhibitory activity of TR3 towards Wnt signalling.

CONCLUSIONS

TR3 is a negative regulator of Wnt signalling and thus significantly suppresses intestinal tumorigenesis in Apc(min/+) mice. This inhibitory effect of TR3 may be paradoxically overcome through phosphorylation by GSK3β in clinical colorectal cancers.

Microsatellite alterations in phenotypically normal esophageal squamous epithelium and metaplasia-dysplasia-adenocarcinoma sequence

AIM: To investigate the microsatellite alterations in phenotypically normal esophageal squamous epithelium and metaplasia-dysplasia-adenocarcinoma sequence.

METHODS: Forty-one specimens were obtained from esophageal cancer (EC) patients. Histopathological assessment identified 23 squamous cell carcinomas (SCC) and 18 adenocarcinomas (ADC), including only 8 ADC with Barrett esophageal columnar epithelium (metaplasia) and dysplasia adjacent to ADC. Paraffin-embedded normal squamous epithelium, Barrett esophageal columnar epithelium (metaplasia), dysplasia and esophageal tumor tissues were dissected from the surrounding tissues under microscopic guidance. DNA was extracted using proteinase K digestion buffer, and DNA was diluted at 1:100, 1:1000, 1:5000, 1:10 000 and 1:50 000, respectively. Seven microsatellite markers (D2S123, D3S1616, D3S1300, D5S346, D17S787, D18S58 and BATRII loci) were used in this study. Un-dilution and dilution polymerase chain reactions (PCR) were performed, and microsatellite analysis was carried out.

RESULTS: No statistically significant difference was found in microsatellite instability (MSI) and loss of heterozygosity (LOH) of un-diluted DNA between SCC and ADC. The levels of MSI and LOH were high in the metaplasia-dysplasia-adenocarcinoma sequence of diluted DNA. The more the diluted DNA was, the higher the rates of MSI and LOH were at the above 7 loci, especially at D3S1616, D5S346, D2S123, D3S1300 and D18S58 loci.

CONCLUSION: The sequence of metaplasia-dysplasia-adenocarcinoma is associated with microsatellite alterations, including MSI and LOH. The MSI and LOH may be the early genetic events during esophageal carcinogenesis, and genetic alterations at the D3S1616, D5S346 and D3S123 loci may play a role in the progress of microsatellite alterations.

[Frequent promoter hypermethylation of several tumor suppressor genes in gastric carcinoma and foveolar epithelium]

OBJECTIVE

To study the promoter hypermethylation of several tumor suppressor genes in gastric carcinoma (GC) tissue and adjacent normal gastric foveolar epithelium (GFE).

METHODS

Methylation specific PCR (MSP) was used to examine the promoter methylation of tumor suppressor genes E-cadherin, hMLH1, APC and MGMT in paraffin-embedded gastric cancer tissue and adjacent normal foveolar epithelium in 106 cases.

RESULTS

The positive rate of genes promoter methylation was 44.3% (47/106 cases) and 72.6% (77/106 cases) at one or more genes tested in the normal GFE and GC tissue, respectively. There was a significant difference in the positive rates of gene promoter methylation between normal GFE and GC tissue (P = 0.0001). There was a significant association with Laurén classification, degree of differentiation and pTNM staging in GC (P < 0.05), but no significant association with Ming's classification (P > 0.05).

CONCLUSION

Tumor suppressor genes promoter methylation is frequently present in GC and adjacent normal gastric foveolar epithelium, especially in Laurén diffuse type GC, poorly differentiated GC, mucus-secreting (signet ring) cell GC and pTNM stage III and IV GC. Our findings indicate that the gene promoter methylation is a common and early event in GC carcinogensis.

Synthesis and biological activities of dibenzyl dipiperazine diquaternary ammonium salts

Twenty new 4,4'-dibenzoyl-1,1'-dibenzyl-1,1'-(decane-1,5-diyl)-piperazi nium dihalides 5a-l and 1,1'-dibenzyl-1,1'-(decane-1,5-diyl)piperazinium dihydrochloride dihalides 6a-l were prepared and evaluated for their analgesic, sedative and anti-inflammatory activities. Structure-activity relationship studies indicated that the compounds 6c (Ar = 4-NO2C6H5) and 6k (Ar = 3-Me-C6H5) exhibited higher activities than others. Compared with the corresponding compounds 6k and 6l, the presence of benzoyl in the compound 5k and 5l exerted a contrary influence on the activities. 5h and 6h show the highest anti-inflammatory activity (59%, dose 20 mg/kg and 48%, dose 1 mg/kg) in the series 5 and 6, respectively.

Spontaneous intestinal carcinomas and skin neoplasms in Msh2-deficient mice

Hereditary nonpolyposis colorectal cancer is associated with defects in DNA mismatch repair. Here, we characterize tumor susceptibility of the recently described Msh2-deficient mouse model. Within the first year of observation, all homozygous mice succumbed to disease, with lymphomas observed in at least 80% of the cases. The majority (70%) of animals 6 months or older developed intestinal neoplasms associated with APC inactivation. Microsatellite instability was more common in carcinomas than in adenomas, but uncommon in normal tissues. Some animals (7%) developed a variety of skin neoplasms analogous to the Muir-Torre syndrome. Msh2-/- mice implicate a direct role for mismatch repair in several neoplasms with striking phenotypic similarities to humans.

MSH2 deficiency contributes to accelerated APC-mediated intestinal tumorigenesis

Accelerated intestinal tumorigenesis is probable in hereditary nonpolyposis colorectal cancer, a condition associated with germ line DNA mismatch repair (MMR) gene defects, and is believed to be caused by rapid accumulation of replication errors in critical genes, such as the APC (adenomatous polyposis coli) tumor suppressor gene. To study the potential contribution of MMR genes to accelerated intestinal tumorigenesis, we crossed the Min mouse, heterozygous for a germ line mutation of Apc, with an MMR gene (Msh2)-deficient mouse. MSH2 deficiency resulted in the development of many colonic aberrant crypt foci, as well as reduced survival of the mice, secondary to both a greater number and more rapidly developing adenomas. The mechanism of inactivation of the wild-type Apc allele depended on MSH2 status. In the presence of functional MSH2, all tumors demonstrated loss of heterozygosity. In contrast, whereas all adenomas were APC negative by immunostaining, only 5 of 34 adenomas from Apc+/-/Msh2-/- mice demonstrated loss of heterozygosity of the wild-type Apc allele, suggesting that somatic Apc mutations are responsible for the additional tumors. These findings provide evidence for the important role of MMR genes in accelerated intestinal tumorigenesis, thus supporting more aggressive surveillance strategies to prevent colorectal cancer in hereditary nonpolyposis colorectal cancer.

[Synergism of sobuzoxane in combination with doxorubicin against leukemia P388 in mice]

AIM

To study the antitumor activity of sobuzoxane (Sob) in combination with doxorubicin (Dox) and the effect of Sob on Dox-induced cardiotoxicity.

METHODS

DBA/2 mice bearing transplanted leukemia P388 were given i.v. Dox 2 mg.kg-1.d-1 for 3 d, 4 mg.kg-1.d-1 for 1 d combined with ig Sob 20, 40 mg.kg-1.d-1 for 7 d. The increase in life span (ILS) of each group was recorded in 30 d. The myocardium of moribund mice was examined by transmission electron microscopy.

RESULTS

The ILS of combination therapeutic groups of Sob with Dox was 48.7%, 57.3%, 59.0%, and 62.4% respectively, which were 30%-90% higher than the sum of ILS of two groups treated with Dox and Sob separately (P < 0.01). The ultrastructural injury of cardiomyocytes of P388-bearing mice caused by combination chemotherapy with Dox plus Sob was markedly attenuated compared with Dox alone.

CONCLUSION

Sob with Dox exhibited an antitumor synergistic effect on leukemia P388, and the cardiotoxicity of Dox was reduced by Sob.

Synthesis and antitumor properties of N1-acyloxymethyl derivatives of bis(2,6-dioxopiperazines)

Many N1-acyloxymethyl derivatives VI of bis(2,6-dioxopiperazine) I, ICRF-154, were prepared and tested for antitumor activity. The treatment of I with formaldehyde gave a crystalline bis(N1-hydroxymethyl) derivative VII, which was acylated under various conditions to give bis(N1-acyloxymethyl) derivatives VI. Antitumor activity of VI against P388 leukemia in mice was studied. Several bis(N1-acyloxymethyl) compounds such as phenylacetyloxymethyl VI-6, methoxycarbonyloxymethyl VI-41, isobutoxycarbonyloxymethyl VI-44, and furancarboxymethyl VI-38 compounds were found to have potent antitumor activities. On the other hand, water-soluble esters having an amine or a carboxylic acid function in their acyl groups showed rather reduced activity. These bis(N1-acyloxymethyl) derivatives VI were presumably hydrolyzed into the parent bis(2,6-dioxopiperazine) I by nonspecific esterase in the body to exhibit their antitumor activity.