A Proteomic Approach to Understand the Clinical Significance of Acute Myeloid Leukemia-Derived Extracellular Vesicles Reflecting Essential Characteristics of Leukemia.

Extracellular vesicle (EV) proteins from acute myeloid leukemia (AML) cell lines were analyzed using mass spectrometry. The analyses identified 2450 proteins, including 461 differentially expressed proteins (290 upregulated and 171 downregulated). CD53 and CD47 were upregulated and were selected as candidate biomarkers. The association between survival of patients with AML and the expression levels of CD53 and CD47 at diagnosis was analyzed using mRNA expression data from The Cancer Genome Atlas database. Patients with higher expression levels showed significantly inferior survival than those with lower expression levels. ELISA results of the expression levels of CD53 and CD47 from EVs in the bone marrow of patients with AML at diagnosis and at the time of complete remission with induction chemotherapy revealed that patients with downregulated CD53 and CD47 expression appeared to relapse less frequently. Network model analysis of EV proteins revealed several upregulated kinases, including LYN, CSNK2A1, SYK, CSK, and PTK2B. The potential cytotoxicity of several clinically applicable drugs that inhibit these kinases was tested in AML cell lines. The drugs lowered the viability of AML cells. The collective data suggest that AML cell-derived EVs could reflect essential leukemia biology.

Definition of the Rectum: An International, Expert-based Delphi Consensus.

BACKGROUND: The wide global variation in the definition of the rectum has led to significant inconsistencies in trial recruitment, clinical management, and outcomes. Surgical technique and use of preoperative treatment for a cancer of the rectum and sigmoid colon are radically different and dependent on the local definitions employed by the clinical team. A consensus definition of the rectum is needed to standardise treatment. METHODS: The consensus was conducted using the Delphi technique with multidisciplinary colorectal experts from October, 2017 to April, 2018. RESULTS: Eleven different definitions for the rectum were used by participants in the consensus. Magnetic resonance imaging (MRI) was the most frequent modality used to define the rectum (67%), and the preferred modality for 72% of participants. The most agreed consensus landmark (56%) was "the sigmoid take-off," an anatomic, image-based definition of the junction of the mesorectum and mesocolon. In the second round, 81% of participants agreed that the sigmoid take-off as seen on computed tomography or MRI achieved consensus, and that it could be implemented in their institution. Also, 87% were satisfied with the sigmoid take-off as the consensus landmark. CONCLUSION: An international consensus definition for the rectum is the point of the sigmoid take-off as visualized on imaging. The sigmoid take-off can be identified as the mesocolon elongates as the ventral and horizontal course of the sigmoid on axial and sagittal views respectively on cross-sectional imaging. Routine application of this landmark during multidisciplinary team discussion for all patients will enable greater consistency in tumour localisation.

Multicenter, randomized single-port versus multiport laparoscopic surgery (SIMPLE) trial in colon cancer: an interim analysis.

BACKGROUND: Single-port laparoscopic surgery (SPLS) was recently introduced as an innovative minimally invasive surgery method. Retrospective studies have revealed the safety and feasibility of SPLS for colon cancer treatment. However, no prospective randomized trials have been performed. The multicenter, randomized SIMPLE (single-port versus multiport laparoscopic surgery) trial aimed to investigate short-term perioperative outcomes of SPLS for colon cancer treatment, compared with multiport laparoscopic surgery (MPLS). METHODS: Between August 2011 and April 2014, a total of 194 patients with colon cancer were recruited from seven hospitals in Korea. Patients were randomly allocated into the SPLS group (n = 99) or MPLS group (n = 95). The primary endpoint was postoperative complications. Operative, postoperative, and pathologic outcomes were analyzed after 50% of the patient study population had been recruited. RESULTS: The patients' demographic characteristics, operative times, estimated blood volume losses, numbers of harvested lymph nodes, and lengths of both resection margins were not significantly different between groups. In the SPLS group, the rates of conversion to MPLS and open surgery were 12.9 and 2.2%, respectively. Postoperative complications occurred in 10.8% of the SPLS, and 12.5% of the MPLS patients (p = 0.714). Times to functional recovery, pain scores, and amounts of analgesia were similar between groups. CONCLUSION: The results of this interim analysis suggested that SPLS is technically safe and appropriate when used for radical resection of colon cancer. (ClinicalTrials.gov Identifier: NCT01480128).

Bidirectional alteration of Cav-1 expression is associated with mitogenic conversion of its function in gastric tumor progression.

BACKGROUND: Expression of caveolin-1 (Cav-1) is frequently altered in many human cancers and both tumor suppression and promotion functions of Cav-1 have been suggested based on its expression status. However, it remains unanswered how Cav-1 provokes opposite effects in different cancers or different phases of tumor progression. METHODS: To explore the implication of Cav-1 alteration in gastric tumorigenesis, the expression and mutational status of Cav-1 and its effects on tumor cell growth were characterized. RESULTS: A substantial fraction of primary tumors and cell lines displayed abnormally low or high Cav-1 mRNA expression, indicating the bidirectional alteration of Cav-1 in gastric cancers. While allelic imbalance and mutational alterations of the Cav-1 gene were rarely detected, aberrant promoter hyper- or hypo-methylation showed a tight correlation with bidirectional alteration of its expression. Abnormally low and high Cav-1 expression was more frequently observed in early and advanced cancers, respectively, suggesting the oncogenic switch of its function in tumor progression. Cell cycle progression, DNA synthesis, and colony forming ability were markedly decreased by Cav-1 transfection in low-expressing tumor cells but by its depletion in high-expressing cells. Interestingly, Cav-1 exerted opposite effects on MEK-ERK signaling in these two cell types through the reciprocal regulation of the RAF-ERK negative feedback loop. A feedback inhibition of RAF by ERK was stimulated by restoration of Cav-1 expression in low-expressing cells but by it depletion in high-expressing cells. As predicted, the opposite effects of Cav-1 on both tumor cell growth and inhibitory RAF phosphorylation were abolished if ERK is depleted. CONCLUSION: Bidirectional alteration of Cav-1 is linked to its opposite effects on gastric tumor cell growth, which stem from the reciprocal control on the RAF-ERK negative feedback loop.

Efficacy and safety of aprepitant for the prevention of chemotherapy-induced nausea and vomiting during the first cycle of moderately emetogenic chemotherapy in Korean patients with a broad range of tumor types.

PURPOSE: This study evaluated the efficacy and safety of a 3-day aprepitant regimen for the prevention of chemotherapy-induced nausea and vomiting (CINV) during the first cycle of non-anthracycline plus cyclophosphamide (AC)-based moderately emetogenic chemotherapy (MEC) based on government guidelines in Korean patients. METHODS: This multicenter, randomized, double-blind, phase IV trial (NCT01636947) enrolled adult South Korean patients with a broad range of tumor types who were scheduled to receive a single dose of ≥1 MEC agent. Patients were randomized to a 3-day regimen of aprepitant (aprepitant regimen) or placebo (control regimen) on top of ondansetron plus dexamethasone. The primary and key secondary efficacy endpoints were the proportions of subjects who achieved no vomiting and complete response (CR) during the overall phase. RESULTS: Of the 494 randomized subjects, 480 were included in the modified intent-to-treat population. Response rates for no vomiting and CR in the overall phase were numerically higher for the aprepitant regimen compared with the control regimen groups, but failed to reach statistical significance (no vomiting 77.2 vs 72.0%; p = 0.191; CR 73.4 vs 70.4%; p = 0.458). Both the aprepitant and control regimens were generally well tolerated. CONCLUSION: A 3-day aprepitant regimen was numerically better but not statistically superior to a control regimen with respect to the achievement of no vomiting or CR during the overall phase in a non-AC MEC Korean population based on government reimbursement guidelines. TRIAL REGISTRATION: ClinicalTrials.gov NCT01636947 ( https://clinicaltrials.Gov/ct2/show/NCT01636947 ).

Learning curve for single-port laparoscopic colon cancer resection: a multicenter observational study.

BACKGROUND: The aim of this study was to investigate the learning curves (LCs) of single-port laparoscopic surgery (SPLS) for colon cancer using multidimensional statistical analyses. Although SPLS yields better cosmetic results and comparable short-term outcomes compared to conventional laparoscopic surgery, its technical difficulties make surgeons hesitant to try SPLS. Moreover, the LCs of SPLS for colon cancer are not well delineated. METHODS: Data were collected from patients who underwent SPLS for colon cancer in seven Korean institutions between May 2009 and May 2015. The LCs were analyzed using the moving average method and the cumulative sum control chart (CUSUM) for operation time and surgical failure. Surgical failure was defined as the any conversion, postoperative complications, or less than 12 harvested lymph nodes from surgical specimens. RESULTS: A total of 356 patients were included in this study. Six and three surgeons performed 282 anterior resections (ARs) and 74 right colectomies (RCs), respectively. On the basis of the moving average method and CUSUM for operation time and surgical failure, the LCs for AR were 18, 16, 35, 13, 36, and 13 cases for surgeons A-F, respectively. However, the LCs for RC were 6 and 15 cases for surgeons D and E, respectively, and were ambiguous for one surgeon. CONCLUSIONS: For surgeons experienced in conventional laparoscopic colorectal surgery, the LCs of SPLS for colon cancer ranged from 6 to 36 cases, which is shorter than the LCs reported for conventional laparoscopic surgery.

Stenting as a Bridge to Surgery for Obstructive Colon Cancer: Does It Have Surgical Merit or Oncologic Demerit?

PURPOSE: To evaluate the surgical and oncologic outcomes of patients undergoing self-expandable metallic stent (SEMS) placement with elective curative surgery. METHODS: Data from patients admitted with obstructing colon cancer between 2000 and 2012 were analyzed retrospectively. Patients underwent either SEMS placement as a bridge to surgery (stent group, n = 67) or emergency surgery (surgery group, n = 35). Surgical and oncologic outcomes of the groups were compared. RESULTS: Placement of SEMS was technically successful in 98.5% and clinically successful in 89.6% of cases. There were eight (11.9%) stent-related complications, including three migrations (4.5%), four occlusions (6.0%), and one perforation (1.5%). The stent group had a higher laparoscopic resection rate (67.2 vs. 31.4%, p = 0.001) with a lower conversion rate (4.3 vs. 35.3%, p = 0.003). The wound infection rate was significantly higher in the surgery group (37.1 vs. 11.9%, p = 0.003) with no differences in the rate of other complications. The rates of local recurrence and distant metastasis, recurrence-free, and overall survival were not significantly different between the two groups. CONCLUSIONS: Stenting and elective surgery was associated with a higher laparoscopy rate, a lower conversion rate, and a lower wound infection rate compared to emergency surgery but did not affect recurrence or survival.

Moderating AKT signaling with baicalein protects against weight loss by preventing muscle atrophy in a cachexia model caused by CT26 colon cancer.

Cancer cachexia is a type of energy-wasting syndrome characterized by fatigue, anorexia, muscle weakness, fat loss, and systemic inflammation. Baicalein, a flavonoid with bioactive properties, has demonstrated the ability to mitigate cardiac and skeletal muscle atrophy in different experimental settings. This effect is achieved through the inhibition of muscle proteolysis, suggesting its potential in preserving skeletal muscle homeostasis. In this study, we investigated the anti-cancer cachexia effects of baicalein in the regulation of muscle and fat wasting, both in vivo and in vitro. Baicalein attenuated body weight loss, including skeletal muscle and white adipose tissue (WAT), in CT26-induced cachectic mice. Moreover, baicalein increased muscle fiber thickness and suppressed the muscle-specific ubiquitin-protease system, including F-box only protein 32 and muscle RING-finger protein-1, by activating AKT phosphorylation both in vivo and in vitro. The use of LY294002, a particular inhibitor of AKT, eliminated the observed impact of baicalein on the improvement of muscle atrophy. In conclusion, baicalein inhibits muscle proteolysis and enhances AKT phosphorylation, indicating its potential role in cancer cachexia-associated muscle atrophy.

Multicenter analysis of risk factors for anastomotic leakage after laparoscopic rectal cancer excision: the Korean laparoscopic colorectal surgery study group.

OBJECTIVE: To assess the risk factors for clinical anastomotic leakage (AL) in patients undergoing laparoscopic surgery for rectal cancer. BACKGROUND: Little data are available about risk factors for AL after laparoscopic rectal cancer resection. METHODS: This was a retrospective analysis of 1609 patients with rectal cancer who had undergone laparoscopic surgery for rectal cancer with sphincter preservation. Clinical data related to AL were collected from 11 institutions. Univariate and multivariate analyses were performed to determine the risk factors for AL. RESULTS: AL was noted in 101 (6.3%) of the patients. The leakage rate ranged from 2.0% to 10.3% for each hospital (P = 0.04). In patients without protective stomas (n = 1187), male sex [hazard ratio (HR), 3.468], advanced tumor stage (HR, 2.520), lower tumor level (HR, 2.418), preoperative chemoradiation (HR, 6.284), perioperative transfusion (HR, 10.705), and multiple firings of the linear stapler (HR, 6.181) were significantly associated with AL. Our theoretical model suggested that the HR for patients with 2 risk factors was significantly higher than that the HR for patients with no or only 1 risk factor. CONCLUSIONS: Male sex, low anastomosis, preoperative chemoradiation, advanced tumor stage, perioperative bleeding, and multiple firings of the linear stapler increased the risk of AL after laparoscopic surgery for rectal cancer. A diverting stoma might be mandatory in patients with 2 or more of the risk factors identified in this analysis.

Clinical outcomes of reintroducing oxaliplatin to patients with colorectal cancer after mild hypersensitivity reactions.

OBJECTIVE: We aimed to evaluate the clinical outcomes of reintroducing oxaliplatin to patients with colorectal cancer who developed mild hypersensitivity reactions (HSRs). METHODS: A retrospective review was performed of 204 patients who received oxaliplatin-based chemotherapies between January 2003 and August 2009. Desensitization was not used. RESULTS: A total of 44 patients (21.6%) were found to have developed HSRs to oxaliplatin. After the occurrence of an HSR, a mean of three courses of oxaliplatin (range 1-8) were introduced. Following the initial episode, oxaliplatin was reintroduced to 39 patients, resulting in HSR relapse in 89.7% of the patients, including 4 patients (10.3%) with grade 3 reactions. After the second re-exposure of oxaliplatin to 22 patients, HSRs were exhibited in 81.8%, including 2 patients (9.1%) who developed grade 3 reactions. After the third and subsequent re-exposures in 12 patients, all except 1 of the patients developed mild reactions. A total of 7 patients (17.9%) exhibited severe reactions along with the progress of re-exposure. CONCLUSION: We observed that the majority of patients who experienced mild HSRs to oxaliplatin developed mild reactions on multiple re-exposures, suggesting that it may be feasible to continue oxaliplatin without using desensitization when tolerable after mild reactions.

Initial experience of single-port laparoscopic surgery for sigmoid colon cancer.

BACKGROUND: Single-port laparoscopic surgery has attracted attention in the field of minimally invasive colorectal surgery. We hypothesized that an experienced laparoscopic surgeon could perform single-port surgery for colon cancer eligible for conventional laparoscopic anterior resection. Our aim was to analyze our initial experience and immediate surgical outcomes of single-port anterior resection. METHODS: A total of 37 consecutive patients with presumed sigmoid colonic cancer underwent single-port anterior resection with standard laparoscopic instruments between May 2009 and June 2010. Each operation was performed by one of two experienced colorectal surgeons. A cohort of patients who had undergone conventional laparoscopic surgery (CLS) for the same duration a year earlier (August 2007 to September 2008) was used as a historical control. Patient demographics and perioperative outcomes were analyzed and compared with those of CLS. RESULTS: There were no significant differences in mean estimated blood loss, mean length of the resection margin, or morbidity between the two groups, but operative time for the single-port group was significantly shorter (118 ± 41 vs. 140 ± 42 min; p = 0.017). Single-port laparoscopic surgery was successfully performed in 78.4% (29/37) of the patients treated in 2010, and CLS was successfully completed in all of the patients treated the previous year (p = 0.000). The main causes of single-port surgery failure were adhesion and tumor location. CONCLUSIONS: Single-port anterior resection is a feasible and safe procedure with immediate outcomes comparable to those of conventional laparoscopy. Further studies are required to determine the feasibility of single-port surgery for colonic tumors outside the sigmoid colon and the long-term outcome.

Characteristic phenotypes in Korean Crohn's disease patients who underwent intestinal surgery for the treatment.

There are no previous large scale studies which have evaluated the phenotypes and clinical characteristics of Korean Crohn's disease patients who underwent intestinal resection. The purpose of this multicenter retrospective cohort study was to evaluate the clinical characteristics of Korean Crohn's disease patients who underwent intestinal resection during the study period. A total of 686 patients were enrolled in this study. The study period was over a 20-yr period (1990-2009). The patients were divided into the first-10-yr group and the second-10-yr group. The phenotypes and clinical characteristics were compared between the groups. The most common site of the disease was the ileal area (37.8%) and stricturing behavior was observed in 38.3% patients. The most common type of surgery was segmental resection of the small bowel (30.6%). These phenotypes showed a similar pattern in both the first and second study period groups and did not show any significant differences between the groups. The number of registered patients increased continuously. The phenotypes of Korean Crohn's disease patients who underwent intestinal resection are different compared with previously reported clinical characteristics of general Crohn's disease patients.

Present condition analysis of physician assistant in Korea.

This study intended to identify the need for the legalization and development of a systematic program for physician assistants (PAs) by understanding the actual state of PA operation in hospitals. In 114 hospitals assigned as resident training hospitals for surgery, a survey was conducted on the personnel working as PAs in those hospitals; the survey included general personal information, working conditions, training time, and satisfaction. A total of 192 PAs in surgery at 35 hospitals responded to the survey. The types of PAs are Surgical Assistant, Clinical Physician Assistant, Wound Ostomy Care Nurse, Coordinator, and Clinical Research Coordinator. Types of work PAs preformed are surgical assistance, wound dressing, educating patients, overlooking consultation, doing paper works, writing operation records, and confirming examination results which were ordered. The satisfaction level for the position which PAs hold were 29.1% and and satisfaction level which doctors see towards PA was 15%. The role and the job descriptions of PAs are not clear cut, there are many discrepancies among hospitals we studied. As a result, legalization and the implementation of standardized role of PAs will lead to increase level of satisfactions in the work force and the quality of work which PAs perform will be greater.

Effect of multimodal intervention care on cachexia in patients with advanced cancer compared to conventional management (MIRACLE): an open-label, parallel, randomized, phase 2 trial.

BACKGROUND: Cancer cachexia (CC) is a multifactorial process characterized by progressive weight loss, muscle mass, and fat tissue wasting, which adversely affects the quality of life and survival of patients with advanced stages of cancer. CC has a complex and multifactorial pathophysiology, and there is no established standard treatment. Therefore, it is often irreversible and a single treatment modality is unlikely to suppress its progression. We are conducting a randomized trial to investigate the efficacy and safety of a multimodal intervention compared to the best supportive care for patients who received palliative chemotherapy. METHODS: Patients with lung or gastrointestinal cancers undergoing palliative chemotherapy are eligible. Patients are randomized into a multimodal intervention care (MIC) arm versus a conventional palliative care (CPC) arm. MIC includes ibuprofen, omega-3-fatty acid, oral nutritional supplement, weekly physical, psychiatric assessment, nutritional counseling, and complementary and alternative medicine. CPC includes basic nutritional counseling and megestrol acetate as needed (i.e., anorexia ≥ grade 2). All interventions are performed for 12 weeks per subject. The co-primary outcomes are change (kg) in total lean body mass and handgrip strength (kg) from the baseline. A total of 112 patients will be assigned to the two arms (56 in each group). DISCUSSION: The purpose of this study is to evaluate the effect of MIC in preventing or alleviating CC in patients who underwent palliative chemotherapy. As there is no established single treatment for CC, it is expected that the results of this clinical trial will provide new insights to significantly improve the quality of life of patients with cancer. Considering the complex mechanisms of cachexia, the effect of MIC rather than a single specific drug is more promising. In this study, we did not overly restrict the type of cancer or chemotherapy. Therefore, we attempted to measure the effects of complex interventions while preserving clinical situations. Thus, it is expected that the results of this study can be applied effectively to real-world practice. TRIAL REGISTRATION: This clinical trial was registered in the Clinical Research Information Service (KCT0004967), Korean Clinical Trial Registry on April 27, 2020, and ClinicalTrial.gov (NCT04907864) on June 1, 2021.

Molecular characterization of dysplasia-initiated colorectal cancer with assessing matched tumor and dysplasia samples.

PURPOSE: Ulcerative colitis (UC) is known to have an association with the increased risk of colorectal cancer (CRC), and UC-associated CRC does not follow the typical progress pattern of adenoma-carcinoma. The aim of this study is to investigate molecular characteristics of UC-associated CRC and further our understanding of the association between UC and CRC. METHODS: From 5 patients with UC-associated CRC, matched normal, dysplasia, and tumor specimens were obtained from formalin-fixed paraffin-embedded (FFPE) samples for analysis. Genomic DNA was extracted and whole exome sequencing was conducted to identify somatic variations in dysplasia and tumor samples. Statistical analysis was performed to identify somatic variations with significantly higher frequencies in dysplasia-initiated tumors, and their relevant functions were investigated. RESULTS: Total of 104 tumor mutation genes were identified with higher mutation frequencies in dysplasia-initiated tumors. Four of the 5 dysplasia-initiated tumors (80.0%) have TP53 mutations with frequent stop-gain mutations that were originated from matched dysplasia. APC and KRAS are known to be frequently mutated in general CRC, while none of the 5 patients have APC or KRAS mutation in their dysplasia and tumor samples. Glycoproteins including mucins were also frequently mutated in dysplasia-initiated tumors. CONCLUSION: UC-associated CRC tumors have distinct mutational characteristics compared to typical adenoma-carcinoma tumors and may have different cancer-driving molecular mechanisms that are initiated from earlier dysplasia status.

Bone Marrow Homeostasis Is Impaired via JAK/STAT and Glucocorticoid Signaling in Cancer Cachexia Model.

Cancer cachexia is a multifactorial systemic inflammation disease caused by complex interactions between the tumor and host tissues via soluble factors. However, whether cancer cachexia affects the bone marrow, in particular the hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs), remains unclear. Here, we investigated the bone marrow and bone in a cancer cachexia animal model generated by transplanting Lewis lung carcinoma cells. The number of bone marrow mononuclear cells (BM-MNCs) started to significantly decrease in the cancer cachectic animal model prior to the discernable loss of muscle and fat. This decrease in BM-MNCs was associated with myeloid skewing in the circulation and the expansion of hematopoietic progenitors in the bone marrow. Bone loss occurred in the cancer cachexia animal model and accompanied the decrease in the bone marrow MSCs that play important roles in both supporting HSCs and maintaining bone homeostasis. Glucocorticoid signaling mediated the decrease in bone marrow MSCs in the cancer cachectic environment. The cancer cachexia environment also skewed the differentiation of the bone marrow MSCs toward adipogenic fate via JAK/STAT as well as glucocorticoid signaling. Our results suggest that the bone loss induced in cancer cachexia is associated with the depletion and the impaired differentiation capacity of the bone marrow MSCs.

Is Laparoscopic Complete Mesocolic Excision and Central Vascular Ligation Really Necessary for All Patients With Right-Sided Colon Cancer?

Colon cancer treatment is on the way to evolution over several decades. The minimally invasive surgery has improved postoperative short-term outcomes. Adjuvant chemotherapy has prolonged the survival of advanced colon cancer patients. Hohenberger proposed the noble concept of complete mesocolic excision (CME) which consists of 3 components: plane surgery, sufficient longitudinal bowel resection, and central vascular ligation (CVL). Mesocolic plane surgery shares the same surgical principle of total mesorectal excision, which is maintaining the intact mesothelial envelope. However, there remain debates about the extent of bowel resection and the level of CVL for maximizing lymph node dissection. There is no solid clinical evidence for the oncological necessity and benefit of extended radical dissection in right hemicolectomy. CME with CVL based on open surgery has been adopted in laparoscopic surgery. So, it is also necessary to look at how the CME could be transformed and successfully implanted in the laparoscopic era. Recent rapid advances in surgical technology and cancer biology are preparing for fundamental changes in cancer surgery. In this study, we reviewed the history, oncological necessity, and compatibility of CME for the right hemicolectomy in the laparoscopic era and outline the new perspectives on the evolution of cancer surgery.

Epigenetic inactivation of the NORE1 gene correlates with malignant progression of colorectal tumors.

BACKGROUND: NORE1 (RASSF5) is a newly described member of the RASSF family with Ras effector function. NORE1 expression is frequently inactivated by aberrant promoter hypermethylation in many human cancers, suggesting that NORE1 might be a putative tumor suppressor. However, expression and mutation status of NORE1 and its implication in colorectal tumorigenesis has not been evaluated. METHODS: Expression, mutation, and methylation status of NORE1A and NORE1B in 10 cancer cell lines and 80 primary tumors were characterized by quantitative PCR, SSCP, and bisulfite DNA sequencing analyses. Effect of NORE1A and NORE1B expression on tumor cell growth was evaluated using cell number counting, flow cytometry, and colony formation assays. RESULTS: Expression of NORE1A and NORE1B transcript was easily detectable in all normal colonic epithelial tissues, but substantially decreased in 7 (70%) and 4 (40%) of 10 cancer cell lines and 31 (38.8%) and 25 (31.3%) of 80 primary carcinoma tissues, respectively. Moreover, 46 (57.6%) and 38 (47.5%) of 80 matched tissue sets exhibited tumor-specific reduction of NORE1A and NORE1B, respectively. Abnormal reduction of NORE1 was more commonly observed in advanced stage and high grade tumors compared to early and low grade tumors. While somatic mutations of the gene were not identified, its expression was re-activated in all low expressor cells after treatment with the demethylating agent 5-aza-dC. Bisulfite DNA sequencing analysis of 31 CpG sites within the promoter region demonstrated that abnormal reduction of NORE1A is tightly associated with promoter CpG sites hypermethylation. Moreover, transient expression and siRNA-mediated knockdown assays revealed that both NORE1A and NORE1B decrease cellular growth and colony forming ability of tumor cells and enhance tumor cell response to apoptotic stress. CONCLUSION: Our data indicate that epigenetic inactivation of NORE1 due to aberrant promoter hypermethylation is a frequent event in colorectal tumorigenesis and might be implicated in the malignant progression of colorectal tumors.

Endo-satinsky clamp for rectal transection during laparoscopic total mesorectal excision.

BACKGROUND: We describe a technique of intracorporeal rectal transection using an endo-Satinsky clamp during laparoscopic total mesorectal excision. METHODS: We use an abdominal approach through 5 trocars. The rectum and mesorectum are mobilized completely. A flexible trocar is placed at the site of a 12-mm right lower abdominal port after the trocar originally placed there is pulled out. The 12-mm trocar originally placed in the right lower abdomen is moved to the suprapubic site, in which a Pfannenstiel incision is anticipated. The endo-Satinsky clamp is inserted through the flexible trocar, and the rectum is grasped with the endo-Satinsky clamp just above the anticipated point of transection. The endostapler is introduced through the 12-mm suprapubic port and is positioned just distal to the clamp. The rectum is then transected. The transected bowel is resected extracorporeally. Anastomosis is completed intracorporeally by use of a double-stapling technique. RESULTS: From February 2007 to March 2009, we performed low anterior resection with use of the endo-Satinsky clamp for 11 patients with rectal cancer (laparoscopic, 10 patients; robot-assisted, 1 patient). There were no operative complications or deaths. Mean operation time was 179.5 minutes (range, 120-265 min). The average number of cartridges used for rectal transection was 1.6 per patient. CONCLUSION: The endo-Satinsky clamp is a useful device for rectal transection and irrigation. The use of this device makes it easier to place an endostapler just distal to the clamp and to transect the rectum in a more appropriate position.