Higher CO_2-insufflation pressure inhibits the expression of adhesion molecules and the invasion potential of colon cancer cells

AIM： To investigate the influence of CO2-insufflation pressure on adhesion, invasion and metastatic potential of colon cancer cells based on adhesion molecules expression. METHODS： With an/n vitro artificial pneumoperitoneum model, SW1116 human colon carcinoma cells were exposed to CO2-insufflation in 5 different pressure groups： 6 mmHg, 9 mmHg, 12 mmHg, 15 mmHg and control group, respectively for 1 h. Expression of E-cadherin, ICAM-I, CD44 and E-selectin was meas- ured at 0, 12, 24, 48 and 72 h after CO2-insufflation using flow cytometry. The adhesion and invasion capacity of SW1116 cells before and after exposure to CO2-insufflation was detected by cell adhesion/invasion assay in vitro. Each group of cells was injected intraperitoneally into 16 BALB/C mice. The number of visible abdominal cavity tumor nodules, visceral metas-tases and survival of the mice were recorded in each group. RESULTS： The expression of E-cadherin, ICAM-1, CD44 and E-selectin in SWl116 cells were changed significantly following exposure to CO2 insufflation at different pressures （P 〈 0.05）. The expression of E-cadherin, CD44 and ICAM-1 decreased with increasing CO2-insufflation pressure. The adhesive/ invasive cells also decreased gradually with increasing pressure as determined by the adhesion/invasion assay. In animal experiments, the number of abdominal cavity tumor nodules in the 15 mmHg group was also significantly lower than that in the 6 mmHg group （29.7± 9.91 vs 41.7±14.90, P = 0.046）. However, the survival in each group was not statistically different. CONCLUSION： CO2-insufflation induced a temporary change in the adhesion and invasion capacity of cancer cells in vitro. Higher CO2-insufflation pressure inhibited adhesion, invasion and metastatic potential in vitro and in vivo, which was associated with reduced expression of adhesion molecules.

Complete mesocolic excision: Lessons from anatomy translating to better oncologic outcome

Since the introduction of complete mesocolic excision(CME) for colon cancer, the oncologic outcome of patients has been greatly improved, which has led to a longer survival and a lower recurrence, just like the total mesorectum excision for rectal cancer. Despite the fact that the exact anatomy of the organ is one of the most vital things for surgeons to conduct surgery, no team has really studied the exact structure of the mesocolon and related attachments for CME, until the mesocolonic anatomy was first formally characterized in 2012. Therefore, this article mainly focuses on the anatomy development of the mesocolon and the achievement in this field. Meanwhile, we introduce the latest progress in laparoscopic surgery for colon cancer achieved by our team.

Expression of γ-synuclein in colorectal cancer tissues and its role on colorectal cancer cell line HCT116

AIM: To investigate the expression pattern of γ-synuclein in colorectal cancer (CRC) tissues, and to study the effects of γ-synuclein on CRC cell line HCT116 biological features in vitro.METHODS: The expression pattern of γ-synuclein was determined in 54 CRC tissues and 30 tumor-matched nonneoplastic adjacent tissues (NNAT) 5 cm away from the tumor via real-time quantitative reverse transcription PCR (RT-PCR) and immunohistochemistry. The relationship between γ-synuclein protein expression and clinicopathological factors of CRC tissues was analyzed. Three small interfering RNA (siRNA) targeting γ-synuclein mRNA plasmids were constructed and transfected into the CRC cell line HCT116. The stable cell lines were selected with G-418 for 28 d, and the biological features of these cells were examined by cell growth curve, soft agar assay, and cell migration and invasion assays in vitro. RESULTS: The expression of γ-synuclein mRNA and protein was much higher in CRC tissue samples than in NNAT samples (P = 0.02, P = 0.036). There was a significant correlation between the γ-synuclein protein expression and clinical stage and lymph node involvement of CRC (P = 0.02, P = 0.033). In functional analysis we found that down-regulation of γ-synuclein expression in HCT116 cells could inhibit the growth, colony formation rate, and migration and invasion ability of HCT116 cells.CONCLUSION: Increased expression of γ-synuclein in CRC tissues and the biological effects of reduced γ-synuclein expression on HCT116 cells suggest that γ-synuclein may play a positive role in the progression of CRC.

Stem cells:a promising candidate to treat neurological disorders

Neurologic impairments are usually irreversible as a result of limited regeneration in the central nervous system.Therefore,based on the regenerative capacity of stem cells,transplantation therapies of various stem cells have been tested in basic research and preclinical trials,and some have shown great prospects.This manuscript overviews the cellular and molecular characteristics of embryonic stem cells,induced pluripotent stem cells,neural stem cells,retinal stem/progenitor cells,mesenchymal stem/stromal cells,and their derivatives in vivo and in vitro as sources for regenerative therapy.These cells have all been considered as candidates to treat several major neurological disorders and diseases,owing to their self-renewal capacity,multi-directional differentiation,neurotrophic properties,and immune modulation effects.We also review representative basic research and recent clinical trials using stem cells for neurodegenerative diseases,including Parkinson＇s disease,Alzheimer＇s disease,and age-related macular degeneration,as well as traumatic brain injury and glioblastoma.In spite of a few unsuccessful cases,risks of tumorigenicity,and ethical concerns,most results of animal experiments and clinical trials demonstrate efficacious therapeutic effects of stem cells in the treatment of nervous system disease.In summary,these emerging findings in regenerative medicine are likely to contribute to breakthroughs in the treatment of neurological disorders.Thus,stem cells are a promising candidate for the treatment of nervous system diseases.

Emerging roles of the ribonucleotide reductase M2 in colorectal cancer and ultraviolet-induced DNA damage repair

AIM:To investigate the roles of the ribonucleotide reductase M2 (RRM2) subunit in colorectal cancer (CRC) and ultraviolet (UV)-induced DNA damage repair. METHODS:Immunohistochemical staining of tissue microarray was performed to detect the expression of RRM2. Seven CRC cell lines were cultured and three human colon cancer cell lines, i.e., HCT116, SW480 and SW620, were used. Reverse transcription polymerase chain reaction and Western blotting were performed to determine the mRNA and protein expression levels of RRM2, respectively. Cell proliferation assay, cell cycle analysis were performed. Cell apoptosis was evaluated by double staining with fluorescein isothiocyanate-conjugated Annexin Ⅴ and propidium iodide (PI) usingAnnexin Ⅴ/PI apoptosis kit. The motility and invasion of CRC cells were assessed by the Transwell chamber assay. Cells were irradiated with a 254 nm UV-C lamp to detect the UV sensitivity after RRM2 depletion. RESULTS:Immunohistochemical staining revealed elevated RRM2 levels in CRC tissues. RRM2 overexpression was positively correlated with invasion depth (P < 0.05), poorly differentiated type (P = 0.0051), and tumor node metastasis stage (P = 0.0015). The expression of RRM2 in HCT116 cells was downregulated after transfection, and HCT116 cell proliferation was obviously suppressed compared to control groups (P < 0.05). In the invasion test, the number of cells that passed through the chambers in the RRM2-siRNA group was 81 ± 3, which was lower than that in the negative control (289 ± 7) and blank control groups (301 ± 7.2). These differences were statistically significant (P < 0.01). Our data suggest that RRM2 overexpression may be associated with CRC progression. RRM2 silencing by siRNA may inhibit the hyperplasia and invasiveness of CRC cells, suggesting that RRM2 may play an important role in the infiltration and metastasis of CRC, which is a potential therapeutic strategy in CRC. In addition, RRM2 depletion increased UV sensitivity. CONCLUSION:These findings suggest that RRM2 may be a facilitating factor in colorectal tumorigenesis and UV-induced DNA damage repair.

Color Doppler ultrasonographic assessment of the risk of injury to major branch of the midddle hepatic vein during laparoscopic cholecystectomy

OBJEGTIVE: To investigate the causes of hemorrhage from the gallbladder bed during laparoscopic cholecystectomy. METHODS: 617 patients who had received laparoscopic cholecystectomy from September, 2000 to March, 2001 at this hospital were reviewed retrospectively. Ninety-one of these patients were selected randomly for prospective observation. Color Doppler ultrasound was used to examine the cause of venous hemorrhage from the gallbladder bed during laparoscopic cholecystectomy and to examine the anatomic relationship between the gallbladder bed and the branches of the middle hepatic vein in 91 patients preoperatively. RESULTS: A large branch of the middle hepatic vein extended closely behind the gallbladder bed in all 91 patients. The mean distance between the closest point (C point) of this branch to the gallbladder bed was 5.0±4.6 mm. The branch of the middle hepatic vein was completely adherent to the gallbladder bed in 14 (15.38%) of the 91 patients. The distance between this branch and the gallbladder bed was within I mm in 10 (10.99%) of the 91 patients. The inside diameter at C point of this branch was 3.2±1.1 mm. The C point was found on the left side of the longitudinal axis of the gallbladder in 31 (34.66%) of the 91 patients, on the right side in 39 patients (42.86%), just on the axis in 21 patients (23.08%). The venous blood flow rate at the C point was 9.9±3.3 cm/s. CONCLUSIONS: A large branch of the middle hepatic vein passes behind the gallbladder. The inside diameter of this branch is relatively larger. The bleeding of this branch during operation can only be stopped by transfixion. The closest point of this vein to the gallbladder is mostly situated on the right side of the longitudinal axis of the gallbladder. Patients with large branches of the middle hepatic vein close to the gallbladder bed are at risk of hemorrhage during laparoscopic cholecystectomy and should be identified preoperatively with ultrasound.

Suppression of colorectal cancer metastasis by nigericin through inhibition of epithelial-mesenchymal transition

AIM: To evaluate the effect of nigericin on colorectal cancer and to explore its possible mechanism. METHODS: The human colorectal cancer (CRC) cell lines HT29 and SW480 were treated with nigericin or oxaliplatin under the conditions specified. Cell viability assay and invasion and metastasis assay were performed to evaluate the effect of nigericin on CRC cells. Sphereforming assay and soft agar colony-forming assay were implemented to assess the action of nigericin on the cancer stem cell properties of CRC cells undergone epithelial-mesenchymal transition (EMT). RESULTS: Compared with oxaliplatin, nigericin showed more toxicity for the HT29 cell line (IC50, 12.92 ± 0.25 μmol vs 37.68 ± 0.34 μmol). A similar result was also obtained with the SW116 cell line (IC50, 15.86 ± 0.18 μmol vs 41.02 ± 0.23 μmol). A Boyden chamber assay indicated that a significant decrease in the number of HT29 cells migrating through polyvinylidene fluoride membrane was observed in the nigericin-treated group, relative to the vehicle-treated group [11 ± 2 cells per high-power field (HPF) vs 19.33 ± 1.52 cells per HPF, P < 0.05]. Compared to the control group, the numbers of HT29 cells invading through the Matrigel-coated membrane also decreased in the nigericin-treated group (6.66 ± 1.52 cells per HPF vs 14.66 ± 1.52 cells per HPF, P < 0.05). Nigericin also reduced the proportion of CD133+ cells from 83.57% to 63.93%, relative to the control group (P < 0.05). Nigericin decreased the number of spheres relative to the control group (0.14 ± 0.01 vs 0.35 ± 0.01, P < 0.05), while oxaliplatin increased the number of spheres relative to the control group (0.75 ± 0.02 vs 0.35 ± 0.01; P < 0.05). Nigericin also showed a decreased ability to form colonies under anchorage-independent conditions in a standard soft agar assay after 14 d in culture, relative to the control group (1.66 ± 0.57 vs 7 ± 1.15, P < 0.05), whereas the colony numbers were higher in the oxaliplatin group relative to the vehicle-treated controls (14.33 ± 0.57 vs 7 ± 1.15, P < 0.05). We further detected the expression of E-cadherin and vimentin in cells treated with nigericin and oxaliplatin. The results showed that HT29 cells treated with nigericin induced an increase in E-cadherin expression and a decrease in the vimentin expression relative to vehicle controls. In contrast, oxaliplatin downregulated the expression of E-cadherin and upregulated the expression of vimentin in HT29 cells relative to vehicle controls. CONCLUSION: This study demonstrated that nigericin could partly reverse the EMT process during cell invasion and metastasis.

Retrospective research of neoadjuvant therapy on tumordownstaging,post-operative complications,and prognosis in locally advanced rectal cancer

BACKGROUND Neoadjuvant therapy(NAT)is becoming increasingly important in locally advanced rectal cancer.Hence,such research has become a problem.AIM To evaluate the downstaging effect of NAT,its impact on postoperative complications and its prognosis with different medical regimens.METHODS Seventy-seven cases from Shanghai Ruijin Hospital affiliated with Shanghai Jiaotong University School of Medicine were retrospectively collected and divided into the neoadjuvant radiochemotherapy(NRCT)group and the neoadjuvant chemotherapy(NCT)group.The differences between the two groups in tumor regression,postoperative complications,rectal function,disease-free survival,and overall survival were compared using theχ2 test and Kaplan-Meier analysis.RESULTS Baseline data showed no statistical differences between the two groups,whereas the NRCT group had a higher rate of T4(30/55 vs 5/22,P<0.05)than the NCT groups.Twelve cases were evaluated as complete responders,and 15 cases were evaluated as tumor regression grade 0.Except for the reduction rate of T stage(NRCT 37/55 vs NCT 9/22,P<0.05),there was no difference in effectiveness between the two groups.Preoperative radiation was not a risk factor for poor reaction or anastomotic leakage.No significant difference in postoperative complications and disease-free survival between the two groups was observed,although the NRCT group might have better long-term overall survival.CONCLUSION NAT can cause tumor downstaging preoperatively or even complete remission of the primary tumor.Radiochemotherapy could lead to better T downstaging and promising overall survival without more complications.

Tweety-Homolog 1 Facilitates Pain via Enhancement of Nociceptor Excitability and Spinal Synaptic Transmission

Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene encoding Ttyh1,we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice,along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey(PAG)in the basal state.More importantly,the peripheral inflammationevoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice.Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release.Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief.Thus,in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.

Strategies and recommendations for the management of gastrointestinal surgery during the COVID-19 pandemic:experience shared by Chinese surgeons

Novel coronavirus disease-2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is an ongoing public-health pandemic worldwide.Although SARS-CoV-2 has been known to spread primarily through respiratory droplets,recent evidence also supports fecal/oral as an additional route of transmission,raising concerns over gastrointestinal(GI)transmission of the infection.Herein,we,as the front-line Chinese GI surgeons,would like to share our experience and lessons in the combat against COVID-19.It is essential to create science-based,rational,and practical strategies during the outbreak of COVID-19.Here,we provide multi-institutional consensus on minimizing disease transmission while continuing to provide care from all aspects for patients in GI surgery,including outpatient clinics,inpatient units,gastrointestinal endoscopy centers,and adjustments in perioperative care.Our experiences and recommendations are worth sharing and may help to establish specific infection-control and outcome measures.

Multiple Polypoid Colonic Metastases from Primary Gastric Signet Ring Cell Carcinoma

To the Editor： Gastric carcinoma is a common gastrointestinal （GI） malignancy while signet ring cell carcinoma （SRCC） is a well-known poorly differentiated histological type that has a strong tendency for metastasis. The dissemination of gastric carcinoma mainly presents in three patterns. The most common approach for metastasis is through the regional lymph node. Hematogenous spread is also very common and mostly occurs in the liver, lungs, bones, and adrenal gland. In addition, direct adjacent invasion, peritoneal seeding, and Krukenberg tumor are less seen but are also very important in clinic with poor prognosis. In this report, we present a case of rare colonic metastases in the form of multiple polyps from primary gastric SRCC.