Responsiveness and minimal clinically important difference of the 6-minute walk distance in patients undergoing colorectal cancer surgery.

PURPOSE: This study aimed to clarify the responsiveness and minimal clinically important difference (MCID) of the 6-minute walk distance (6MWD) from before and 1 week after surgery in patients with colorectal cancer (CRC). METHODS: This retrospective cohort study enrolled 97 patients with primary CRC scheduled for surgery. An anchor-based approach estimated the MCID of the 6MWD, with postoperative physical recovery and EuroQol 5-dimension 5L questionnaire assessments serving as anchors. Effect size (ES) and standardized response mean (SRM) of the 6MWD were calculated to evaluate responsiveness, and the receiver operating characteristic (ROC) curve was used to estimate the MCID of the 6MWD. RESULTS: Of the 97 patients, 72 were included in the analysis. The absolute value of ES and SRM of the 6MWD were 0.69 and 0.91, respectively. The ROC curve indicated that the optimal cut-off values for estimating the MCID of the 6MWD were -60 m (area under the curve [AUC] = 0.753 [95% CI: 0.640-0.866]) and -75 m (AUC = 0.870 [95% CI: 0.779-0.961]) at each anchor. CONCLUSION: From before to 1 week after surgery, the responsiveness of the 6MWD was favorable, and the MCID of the 6MWD was -75 to -60 m in patients with CRC.

The association between objectively measured preoperative light-intensity physical activity and postoperative ambulation in patients with gastrointestinal cancer.

[Purpose] To clarify the association between preoperative physical activity and postoperative ambulation based on physical activity intensity, and independent of functional capacity and depression, in patients with gastrointestinal cancer. [Participants and Methods] Seventy patients who underwent surgery for primary colorectal or gastric cancer were enrolled. Preoperative moderate-to-vigorous-intensity physical activity, light-intensity physical activity, and sedentary behavior were assessed using an accelerometer. The primary outcome was the days to postoperative first ambulation (capable of independently and continuously walking 150 m). Functional capacity and depression, as confounders, were evaluated by measuring the 6-minute walk distance and using the Hospital Anxiety and Depression Scale. [Results] Of the 70 patients, 28 had insufficient accelerometer data, and 42 were included in the analysis. Preoperative light-intensity physical activity, but not moderate-to-vigorous-intensity physical activity and sedentary behavior, was negatively associated with the days to postoperative first ambulation, after adjusting for age, preoperative functional capacity, and preoperative depression. [Conclusion] Preoperative light-intensity physical activity was associated with the days to postoperative ambulation independently of age, functional capacity, and depression. Hence, predicting delayed ambulation by preoperative light-intensity physical activity in patients with gastrointestinal cancer may be useful.

Prolonged preoperative sedentary time is a risk factor for postoperative ileus in patients with colorectal cancer: a propensity score-matched retrospective study.

PURPOSE: This study aimed to investigate the association between prolonged preoperative sedentary time (ST) and postoperative ileus (POI) after adjusting for confounders in patients with colorectal cancer (CRC). METHODS: This single-center retrospective study enrolled 155 consecutive patients who underwent surgery for primary CRC. A diagnosis of POI was made by the surgeons if the Clavien-Dindo classification (CD) grade is ≥ 2 within 30 days after surgery. Preoperative ST was assessed using the International Physical Activity Questionnaire usual week short version (Japanese version). Patients were classified into two groups (ST < 6 h/day and ST ≥ 6 h/day) based on results from the questionnaire, and data were analyzed using a propensity score-matching strategy to adjust for confounders. In addition, receiver operating characteristic (ROC) curve analysis was performed to identify the optimal cutoff value of preoperative ST for predicting POI. RESULTS: Of the 155 patients, 134 were included in the analysis. POI occurred in 16 (11.9%) patients of overall patients and 11 (12.5%) of the 88 matched patients. The logistic regression analysis after propensity score-matching showed that prolonged preoperative ST (ST ≥ 6 h/day) was associated with POI (odds ratio 5.40 (95% confidence interval: 1.09 - 26.60), p = 0.038). The ROC curve analysis indicated that the optimal cutoff value of preoperative ST for predicting POI was 6 h/day. CONCLUSION: Prolonged preoperative ST is a risk factor for POI in patients with CRC. Therefore, reducing preoperative ST may play an important role in preventing POI.

The impact of cervical lymph node dissection on acid and duodenogastroesophageal reflux after intrathoracic esophagogastrostomy following transthoracic esophagectomy.

PURPOSE: The aim of this study was to evaluate the impact of cervical lymph node dissection on acid reflux and duodenogastroesophageal reflux (DGER) in patients undergoing transthoracic esophagectomy with gastric tube reconstruction and intrathoracic esophagogastrostomy. METHODS: Thirty-one patients receiving transthoracic esophagectomy with gastric tube reconstruction by intrathoracic esophagogastrostomy were divided into the following two groups: a two-field lymph node dissection group (2F group) and a three-field lymph node dissection group (3F group). All patients underwent 24-h pH and bilirubin monitoring and gastrointestinal endoscopy at 1 year after surgery. The 24-h pH and bilirubin monitoring results, endoscopic findings, and reflux symptoms were compared between the 2 groups. RESULTS: No acid reflux was observed in the 2F group, whereas it was observed in 6 (40%) patients in the 3F group (p = 0.007). DGER was found in 2 patients (13%) in the 2F group and in 8 (53%) in the 3F group (p = 0.023). Four patients (25%) in the 2F group and 9 (60%) in the 3F group (p = 0.048) had reflux esophagitis. CONCLUSION: Cervical lymph node dissection increases acid reflux and DGER and can lead to an increase in the incidence of reflux esophagitis in patients undergoing intrathoracic esophagogastrostomy.

The Impact of the Location of Esophagogastrostomy on Acid and Duodenogastroesophageal Reflux After Transthoracic Esophagectomy with Gastric Tube Reconstruction and Intrathoracic Esophagogastrostomy.

BACKGROUND: The aim of this study was to evaluate the impact of the location of esophagogastrostomy on acid and duodenogastroesophageal reflux (DGER) in patients undergoing gastric tube reconstruction and intrathoracic esophagogastrostomy. METHODS: Thirty patients receiving transthoracic esophagectomy without cervical lymph node dissection and gastric tube reconstruction by intrathoracic anastomosis were enrolled. All patients underwent 24-h pH and bilirubin monitoring and gastrointestinal endoscopy one year after surgery. Patients were divided into three groups according to esophagogastrostomy location: group A (n = 9), above the top of the aortic arch; group B (n = 15), between the top and bottom of the aortic arch; and group C (n = 6), below the bottom of the aortic arch. The relations among the esophagogastrostomy location, 24-h pH and bilirubin monitoring results, endoscopic findings, and reflux symptoms were investigated. RESULTS: No acid reflux into the remnant esophagus was observed in group A, whereas it was observed in three of 15 patients (20%) in group B and in two of six patients (33%) in group C (P = 0.139). No DGER was found in group A, whereas DGER was observed in eight (53%) patients in group B and all patients in group C (P < 0.001). Reflux esophagitis was observed in one patient (11%) in group A, five patients (33%) in group B, and all patients in group C (P = 0.002). CONCLUSION: In gastric tube reconstruction via intrathoracic anastomosis, esophagogastrostomy should be performed above the top of the aortic arch to prevent postoperative DGER and reduce the incidence of reflux esophagitis.

The Benefits of a Wound Protector in Preventing Incisional Surgical Site Infection in Elective Open Digestive Surgery: A Large-Scale Cohort Study.

BACKGROUND: The objective of this study was to evaluate the benefits of wound protectors (WPs) in preventing incisional surgical site infection (I-SSI) in open elective digestive surgery using data from a large-scale, multi-institutional cohort study. METHODS: Patients who had elective digestive surgery for malignant neoplasms between November 2009 and February 2011 were included. The protective value of WPs against I-SSI was evaluated. RESULTS: A total of 3201 patients were analyzed. A WP was used in 1022 patients (32%). The incident rate of I-SSI (not including organ/space SSI) was 9%. In the univariate and the multivariate analyses for perioperative risk factors for I-SSI, the use of WP was an independent favorable factor that reduced the incidence of I-SSI (odds ratio 0.73, 95% confidence interval 0.55-0.98. P = 0.038). The subgroup forest plot analyses revealed that WP reduced the risk of I-SSI only in patients aged 74 years or younger, males, non-obese patients (body mass index <25 kg/m2), patients with an American Society of Anesthesiologists score of 1/2, patients with a previous history of laparotomy, non-smokers, and patients who underwent colon and rectum operations. In patients who underwent colorectal surgery, the postoperative hospital stay was significantly shorter in patients with WP than those without WP (median 13 vs. 15 days, P = 0.040). In terms of the depth of SSI, WP only prevented superficial I-SSI and did not reduce the incidence of deep I-SSI. CONCLUSIONS: WP is a useful device for preventing superficial I-SSI in open elective digestive surgery. TRIAL REGISTRATION NUMBER: UMIN000004723.

Clinical value of a prophylactic minitracheostomy after esophagectomy: analysis in patients at high risk for postoperative pulmonary complications.

BACKGROUND: The aim of this study is to evaluate the clinical value of a prophylactic minitracheostomy (PMT) in patients undergoing an esophagectomy for esophageal cancer and to clarify the indications for a PMT. METHODS: Ninety-four patients who underwent right transthoracic esophagectomy for esophageal cancer between January 2009 and December 2013 were studied. Short surgical outcomes were retrospectively compared between 30 patients at high risk for postoperative pulmonary complications who underwent a PMT (PMT group) and 64 patients at standard risk without a PMT (non-PMT group). Furthermore, 12 patients who required a delayed minitracheostomy (DMT) due to postoperative sputum retention were reviewed in detail, and risk factors related to a DMT were also analyzed to assess the indications for a PMT. RESULTS: Preoperative pulmonary function was lower in the PMT group than in the non-PMT group: FEV1.0 (2.41 vs. 2.68 L, p = 0.035), and the proportion of patients with FEV1.0% <60 (13.3% vs. 0%, p = 0.009). No between-group differences were observed in the proportion of patients who suffered from postoperative pneumonia, atelectasis, or re-intubation due to respiratory failure. Of the 12 patients with a DMT, 11 developed postoperative pneumonia, and three required re-intubation due to severe pneumonia. Multivariate analysis revealed FEV1.0% <70% and vocal cord palsy were independent risk factors related to a DMT. CONCLUSION: A PMT for high-risk patients may prevent an increase in the incidence of postoperative pneumonia and re-intubation. The PMT indications should be expanded for patients with vocal cord palsy or mild obstructive respiratory disturbances.

Muscle sparing thoracotomy for esophageal cancer: a comparison with posterolateral thoracotomy.

PURPOSE: The aim of this study was to investigate whether muscle sparing thoracotomy (MST) improved postoperative chest pain and an impairment of the postoperative pulmonary function in comparison with posterolateral thoracotomy (PLT). METHODS: Twenty-four patients with esophageal cancer who underwent PLT from September 2006 to August 2008 and 30 patients who underwent MST from September 2008 to August 2010 were selected as subjects of this study. Postoperative acute and chronic chest pain and the recovery of the pulmonary function were retrospectively compared between the two groups. RESULTS: The frequency of the additional use of analgesics was on days 3, 6, and 7 (mean 0.4 vs. 1.2, p = 0.027, 0.4 vs. 1.5, p = 0.007, and 0.2 vs. 1.2, p = 0.009, respectively) in the early postoperative period. The number of patients requiring analgesics at 1 and 3 months after surgery was significantly lower in the MST group than in the PLT group (13.3 vs. 58.3 %, p = 0.002, 10.0 vs. 50.0 %, p = 0.001, respectively). The postoperative vital capacity, expressed as a percentage of the preoperative value, 3 and 12 months after surgery was significantly higher in the MST group than in the PLT group (86.0 vs. 73.8 %, p = 0.028, 93.2 vs. 76.9 %, p = 0.002, respectively). CONCLUSION: Compared with PLT, MST might, therefore, reduce postoperative chest pain and offer a better recovery of pulmonary function in patients with esophageal cancer.

Two-stage operation for synchronous triple primary cancer of the esophagus, stomach, and ampulla of Vater: report of a case.

A 69-year-old man with jaundice was diagnosed with cancer of the ampulla of Vater by endoscopic retrograde cholangiopancreatography and abdominal computed tomography. A screening gastrointestinal endoscopy showed middle thoracic esophageal cancer and early gastric cancer on the anterior wall of the lower gastric body. We chose a two-stage operation for synchronous triple primary cancer of the esophagus, stomach, and ampulla of Vater, in order to safely perform the curative resection of these three cancers. The first-stage operation consisted of a right transthoracic subtotal esophagectomy with mediastinal and cervical lymph node dissection, an external esophagostomy in the neck, and a gastrostomy. Thirty-five days after the first surgery, a total gastrectomy with regional lymph node dissection, and a pancreatoduodenectomy with Child's reconstruction were performed as the second-stage surgery. Esophageal reconstruction was achieved using the ileocolon via the percutaneous route without vascular anastomosis.

Risk factors for incisional surgical site infections in elective surgery for colorectal cancer: focus on intraoperative meticulous wound management.

PURPOSE: An incisional surgical site infection (I-SSI) is a frequently observed complication following colorectal surgery. Intraoperative wound management is one of the most important factors that determine the incidence of postoperative I-SSI. The purpose of this study was to assess the impact of the methods used for intraoperative wound management on the incidence of I-SSI following elective surgery for colorectal cancer. METHODS: Between November 2009 and February 2011, the data of 1,980 consecutive patients who underwent elective colorectal resection for colorectal cancer were prospectively collected from 19 affiliated hospitals. The incidence of and risk factors for I-SSI were investigated. RESULTS: Overall, 233 I-SSIs were identified (11.7 %). Forty-two possible risk factors were analyzed. Using a multivariate analysis, the independent risk factors for I-SSI were identified to be a high body mass index, previous laparotomy, chronic liver disease, wound length, contaminated wound class, creation or closure of an ostomy, right hemicolectomy procedure, the suture material used for fascial closure and the incidence of organ/space SSI. CONCLUSION: To prevent I-SSI following elective colorectal surgery, it is crucial to avoid making large incisions and reduce fecal contamination whenever possible. A high quality randomized control trial is necessary to confirm the definitive intraoperative procedure(s) that can minimize the incidence of I-SSI.

[Concept of perihilar cholangiocarcinoma in the General Rules for Clinical and Pathological Studies on Cancer of the Biliary Tract, 6th edition].

Hilar cholangiocarcinoma is clinically characterized by biliary obstruction in the porta hepatis. Because the boundary between the intrahepatic and extrahepatic bile duct is unclear, hilar cholangiocarcinoma can potentially arise from both ducts. Therefore, the definition of hilar cholangiocarcinoma remains under debate. In November 2013, the 6th edition of the General Rules for Clinical and Pathological Studies on Cancer of the Biliary Tract was released, following the American Joint Committee on Cancer (AJCC) or International Union Against Cancer (UICC) TNM system. In that edition, as an alternative to "hilar cholangiocarcinoma," the new term "perihilar cholangiocarcinoma" is defined as cholangiocarcinoma involving the perihilar bile duct, despite the presence or absence of a significant liver mass component. This definition clearly indicates that some intrahepatic as well as extrahepatic perihilar tumors are involved in the perihilar tumor category. From the clinical point of view, there is no need for a differential diagnosis between intrahepatic or extrahepatic tumors therefore, the new definition is readily applicable in multidisciplinary team management. Japanese clinicians were previously required to distinguish between the proper use of the AJCC/UICC and the Japanese staging systems, but now the current revision will allow the more convenient use of a single, globally standardized staging system in daily practice.

[A case of mediastinal lymph node gastric cancer recurrence during S-1 adjuvant therapy successfully treated with cisplatin + capecitabine as second-line chemotherapy].

S-1 adjuvant chemotherapy following radical surgery has been the standard therapy for the pStage II/III gastric cancer in Japan. However, there are few reports regarding treatment for gastric cancer recurrence during S-1 therapy. Here, we present a case of recurrent gastric cancer during S-1 adjuvant therapy that showed partial response to CDDP + capecitabine therapy. A 72-year-old man was diagnosed as having gastric cancer. We performed a distal gastrectomy+D2 dissection, with Roux-en Y reconstruction. The patient was treated with S-1 for adjuvant chemotherapy. Six months after operation, multiple mediastinal lymph node recurrence developed. CDDP + CPT-11 was applied for two courses as first-line treatment for the recurrence. However, the disease progressed with worsening mediastinal lymph node metastases (progressive disease). After two courses of CDDP + capecitabine as second-line chemotherapy, the recurrence site became smaller. After five courses, partial response (PR) had been achieved. Two years and five months after gastrectomy, capecitabine monotherapy was applied as third-line chemotherapy.

[Panitumumab as third-line chemotherapy shrank unresectable multiple liver metastases from rectal cancer, making them resectable - report of a case].

We report a case of unresectable multiple liver metastases, in which there was such a good response to panitumumab as third-line chemotherapy, that they were converted into resectable metastases. A 67-year-old man was admitted to our department for rectal cancer with synchronous unresectable multiple liver metastases. After the primary lesion was resected, modified FOLFOX6 regimen was started as first-line chemotherapy. After 10 courses of FOLFOX6 followed by 14 courses of sLV5FU2 regimen, the liver metastases became smaller and were thought to be resectable. Before hepatectomy, we performed portal vein embolization to enlarge the remnant liver, but the tumor grew larger again and we had to cancel the operation. Then, the second-line chemotherapy with FOLFIRI regimen failed. As third-line chemotherapy, panitumumab alone was administered to him and the tumor greatly shrank after 5 courses. We were able to resect the liver metastases with extended right posterior segmentectomy and partial resection. He has been well without recurrence for one year since hepatectomy. This case is rare in that panitumumab alone as third-line chemotherapy shrank unresectable liver metastases and made them resectable. The result is highly suggestive for management, including chemotherapy and operation of multiple liver metastases from colorectal cancer.

[Borderline resectable pancreatic cancer - a definition and effective treatment strategy].

The survival benefit of extended surgery for advanced pancreatic cancer has been denied by four randomized controlled trials. However, there still is confusion and conflict over the definition and effective treatment strategy for so-called locally advanced or borderline resectable pancreatic cancer. Although there are a number of reports that showed outcomes of preoperative chemotherapy or chemoradiotherapy for this disease, the definitions and treatment regimens described in these studies vary. Moreover, all of the studies were Phase I / II trials or retrospective analysis, and there is no Phase III trial currently focused on this issue. It is urgently necessary to establish an international consensus on the definition of borderline resectable pancreatic cancer. The usefulness of neoadjuvant treatment for this disease should also be elucidated in future clinical trials. In this review article, we discuss the current understanding and definition of borderline resectable pancreatic cancer, and the value of neoadjuvant treatment strategy for treating it.

Preoperative Low Physical Activity is a Predictor of Postoperative Delirium in Patients with Gastrointestinal Cancer: A Retrospective Study.

BACKGROUND: Postoperative delirium (POD) is one of the most common postoperative complications in gastrointestinal surgery patients. POD has been reported to affect long-term activities of daily living, cognitive function decline, and mortality. Previous studies have indicated that preoperative physical activity (PA) predicted POD in patients with other diseases, but we have not found any reports in patients with gastrointestinal cancer. In this retrospective study, we investigated the relationship between preoperative PA and POD in gastrointestinal cancer patients. METHODS: POD was diagnosed based on the short confusion assessment method. We divided patients into active and inactive groups based on their preoperative PA assessed by the International Physical Activity Questionnaire (Japanese version). Multivariate logistic analysis was conducted to investigate the association between preoperative PA and POD. RESULTS: POD occurred in 25 of the 151 patients (16.6%). Preoperative low PA was associated with POD after adjusting for confounders, namely, diabetes mellitus, sedentary time, and usual gait speed (odds ratio, 2.83; 95% confidence interval: 1.06-7.58; p=0.03). CONCLUSION: Preoperative low PA was a predictor of POD independent of the confounding factors in patients with gastrointestinal cancer.

Preoperative physical activity predicts postoperative functional recovery in gastrointestinal cancer patients.

PURPOSE: The present study aimed to investigate the association between preoperative physical activity (PA) and postoperative functional recovery in gastrointestinal cancer patients. MATERIALS AND METHODS: In this prospective study, we included 101 patients who underwent colorectal or gastric cancer surgery. Primary outcome was 6-minute walk distance (6MWD) decline ratio ((postoperative 6MWD value - preoperative 6MWD value)/preoperative 6MWD value × 100 (%)), which was determined as postoperative functional recovery. Patients were divided into two groups according to the median of 6MWD decline ratio: above the median (non-decline group) and below the median (decline group). The International Physical Activity Questionnaire (IPAQ-SV) (the usual seven-day short version) was used to assess preoperative PA and sedentary time. Multivariate logistic regression analysis was performed to identify predictive factors of postoperative functional recovery. RESULTS: Preoperative PA (odds ratio (OR): 3.812; 95% confidence interval (CI): 1.326-10.956; p = 0.01), 6MWD (OR: 1.006; 95% CI: 1.002-1.011; p < 0.01), C-reactive protein (OR: 4.138; 95% CI: 1.383-12.377; p = 0.01), and combined resection (OR: 3.425; 95% CI: 1.101-10.649; p = 0.03) were associated with postoperative functional recovery. CONCLUSIONS: Preoperative PA is a predictor of postoperative functional recovery in patients who undergoing gastrointestinal cancer surgery.Implications for rehabilitationThe association between preoperative physical activity (PA) and postoperative functional recovery has been unclear in gastrointestinal cancer patients.We indicated that preoperative PA predicts postoperative functional recovery.Patients who low preoperative PA need to be monitored carefully in the postoperative course.Patients with low preoperative PA may need enhanced postoperative rehabilitation to reduce postoperative functional decline.

Antitumor effects of α-bisabolol against pancreatic cancer.

In the present study, we investigated whether α-bisabolol, a sesquiterpene alcohol present in essential oils derived from a variety of plants, has antitumor effects against pancreatic cancer. α-Bisabolol induced a decrease in cell proliferation and viability in pancreatic cancer cell lines (KLM1, KP4, Panc1, MIA Paca2), but not in pancreatic epithelial cells (ACBRI515). α-Bisabolol treatment induced apoptosis and suppressed Akt activation in pancreatic cancer cell lines. Furthermore, α-bisabolol treatment induced the overexpression of early growth response-1 (EGR1), whereas EGR1 siRNA decreased the α-bisabolol-induced cell death of KLM1 cells. Tumor growth in both subcutaneous and peritoneal xenograft nude mouse models was significantly inhibited by intragastric administration of 1000 mg/kg of α-bisabolol, once a week for three weeks. The results indicate that α-bisabolol could be a novel therapeutic option for the treatment of pancreatic cancer.

Epithelial-mesenchymal transition induced by transforming growth factor-{beta}1/Snail activation aggravates invasive growth of cholangiocarcinoma.

Epithelial-mesenchymal transition is an important mechanism behind initiation of cancer invasion and metastasis. This study was performed to clarify the involvement of epithelial-mesenchymal transition in the progression of cholangiocarcinoma. Cholangiocarcinoma cell lines, CCKS-1 and TFK-1, were treated with transforming growth factor-beta1 (TGF-beta1), and the phenotypic changes and invasive activity were examined. Immunohistochemical analysis was performed using tissue sections of cholangiocarcinoma. In vitro, TGF-beta1 induced mesenchymal features in CCKS-1 and TFK-1 characterized by the reduction of E-cadherin and cytokeratin 19 expression and the induction of mesenchymal markers, such as vimentin and S100A4. TGF-beta1 also induced the nuclear expression of Snail, and the invasive activity was significantly increased in both cell lines. Studies using a mouse xenograft model showed that TGF-beta1 worsened the peritoneal dissemination of CCKS-1. All these changes by TGF-beta1 were inhibited by the simultaneous administration of soluble TGF-beta type II receptor. In vivo, six (16%) of 37 cholangiocarcinoma cases showed marked immunoreactivity of Snail in their nuclei. In these six cases, the immuno-expression of cytokeratin 19 was significantly reduced, and the expression of vimentin was significantly increased. The Snail expression significantly correlated with the lymph node metastasis and a poor survival rate of the patients. These results suggest that epithelial-mesenchymal transition induced by TGF-beta1/Snail activation is closely associated with the aggressive growth of cholangiocarcinoma, resulting in a poor prognosis.

Histone deacetylase inhibitor (SAHA) and repression of EZH2 synergistically inhibit proliferation of gallbladder carcinoma.

Polycomb group protein EZH2, frequently overexpressed in malignant tumors, is the catalytic subunit of polycomb repressive complex 2 (PRC2). PRC2 interacts with HDACs in transcriptional silencing and relates to tumor suppressor loss. We examined the expression of HDAC isoforms (HDAC 1 and 2) and EZH2, and evaluated the possible use of HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) and EZH2 repressor for gallbladder carcinoma. We used 48 surgically resected gallbladders and cultures of human gallbladder epithelial cells (HGECs), gallbladder carcinoma (TGBC2TKB), and cholangiocarcinoma (HuCCT-1 and TFK-1) cell lines for examination. Immunohistochemically, EZH2 was overexpressed in gallbladder carcinoma, especially poorly differentiated carcinoma, but not in normal epithelium. In contrast, HDAC1/2 were expressed in both carcinoma and normal epithelium in vivo. This pattern was verified in cultured cells; EZH2 was highly expressed only in TGBC2TKB, whereas HDAC1/2 were expressed in HGECs and TGBC2TKB. Interestingly, SAHA treatment caused significant cell number decline in three carcinoma cells, and this effect was synergized with EZH2 siRNA treatment; however, HGECs were resistant to SAHA. In TGBC2TKB cells, the expression of EZH2 and HDAC1/2 were decreased by SAHA treatment, and p16(INK4a), E-cadherin, and p21were simultaneously activated; however, no such findings were obtained in HGECs, suggesting that the effect of SAHA depends on the EZH2-mediated tumor suppressor loss. In conclusion, this study suggests a possible mechanism by which carcinoma cells but not normal cells are sensitive to SAHA and indicates the efficacy of this new anticancer agent in combination with EZH2 repression in gallbladder carcinoma.

Cyclooxygenase-2 is involved in the up-regulation of matrix metalloproteinase-9 in cholangiocarcinoma induced by tumor necrosis factor-alpha.

Matrix metalloproteinase-9 (MMP-9) is an important enzyme in tumor invasion and metastasis in malignant tumors, including cholangiocarcinoma (CC). Tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine, was recently reported to induce the up-regulation of MMP-9 in cultured CC cells. We examined whether cyclooxygenase-2 (COX-2) and prostaglandin-E2 (PGE2), another endogenous tumor promoter, are involved in the up-regulation of MMP-9 in CC using CC tissue specimens and a CC cell line, HuCCT-1. MMP-9 and COX-2 were immunohistochemically expressed in 58% and 89% of 110 CC cases, respectively; the expression of MMP-9 and COX-2 was correlated (r = 0.32, P = 0.00072). Using zymography, latent MMP-9 was detectable in all cases and active MMP-9 was detected in 24% of cases of the CC specimens. The TNF-alpha/TNF-receptor 1 (TNF-R1) interaction induced MMP-9 production and activation, as well as COX-2 overexpression and PGE2 production, and increased the migration of CC cells. MMP-9 up-regulation was inhibited by COX inhibitors, antagonists of EP2/4 (receptors of PGE2), and COX-1 and COX-2 siRNAs. Inhibitors of both MMP-9 and MMP-9 siRNA treatment abrogated the increase in the migration of CC cells induced by TNF-alpha. In conclusion, we propose a novel signaling pathway of MMP-9 up-regulation in CC cells such that TNF-alpha induces the activation of COX-2 and PGE2 via TNF-R1 followed by the up-regulation of MMP-9 via the PGE2 (EP2/4) receptor.