Sadaaki Yamazoe

Tumor-associated MUC5AC stimulates in vivo tumorigenicity of human pancreatic cancer

MUC5AC, a high molecular weight glycoprotein, is overexpressed in the ductal region of human pancreatic cancer but is not detectable in the normal pancreas, suggesting its association with disease development. In the present study, we investigated the in vitro and in vivo effects of MUC5AC knockdown by short interfering RNA (siRNA) in the MUC5AC-overexpressing SW1990 and BxPC3 human pancreatic cancer cell lines in order to clarify its function. Significant decreases in the expression levels of MUC5AC mRNA and protein were observed in SW1990 and BxPC3 cells that had been stably transfected with a MUC5AC siRNA expression vector (SW1990/si-MUC5AC and BxPC3/si-MUC5AC cells) compared to those in cells transfected with an si-mock vector (SW1990/si-mock and BxPC3/si-mock cells). In in vitro studies, neither type of MUC5AC-knockdown cell showed any difference in cell survival, proliferation, or morphology from the si-mock cells or parental cells. However, in vivo xenograft studies demonstrated that MUC5AC knockdown significantly reduced the tumorigenicity and suppressed the tumor growth of si-MUC5AC cells compared to those of the si-mock cells. Immunohistochemical analysis revealed that CD45R/B220+ and Gr-1+ cells had infiltrated into the tumor tissue of the SW1990/si-MUC5AC cells. Furthermore, cancer-associated antigen specific antibodies were detected at high levels in the sera from the SW1990/si-MUC5AC cell-bearing mice. These results suggest that tumor-associated MUC5AC expressed on the surface of pancreatic cancer cells supports the escape of pancreatic cancer cells from immunosurveillance. The present findings highlight a new dimension of MUC5AC as a functional immunosuppressive agent and its important role in pancreatic cancer progression.

RNA interference suppression of mucin 5AC (MUC5AC) reduces the adhesive and invasive capacity of human pancreatic cancer cells

BackgroundMUC5AC is a secretory mucin normally expressed in the surface muconous cells of stomach and bronchial tract. It has been known that MUC5AC de novo expression occurred in the invasive ductal carcinoma and pancreatic intraepithelial neoplasm with no detectable expression in normal pancreas, however, its function remains uncertain. Here, we report the impact of MUC5AC on the adhesive and invasive ability of pancreatic cancer cells.MethodsWe used two MUC5AC expressing cell lines derived from human pancreatic cancer, SW1990 and BxPC3. Small-interfering (si) RNA directed against MUC5AC were used to assess the effects of MUC5AC on invasion and adhesion of pancreas cancer cells in vitro and in vivo. We compared parental cells (SW1990 and BxPC3) with MUC5AC suppressed cells by si RNA (si-SW1990 and si-BxPC3).ResultsMUC5AC was found to express in more than 80% of pancreatic ductal carcinoma specimens. Next we observed that both of si-SW1990 and si-BxPC3 showed significantly lower adhesion and invasion to extracellular matrix components compared with parental cell lines. Expression of genes associated with adhesion and invasion including several integerins, matrix metalloproteinase (MMP) -3 and vascular endothelial growth factor (VEGF) were down-regulated in both MUC5AC suppressed cells. Furthermore, production of VEGF and phosphorylation of VEGFR-1 were significantly reduced by MUC5AC down regulation. Both of si-SW1990 and si-BxPC3 attenuated activation of Erk1/2. In vivo, si-SW1990 did not establish subcutaneous tumor in nude mice.ConclusionsKnockdown of MUC5AC reduced the ability of pancreatic cancer cells to adhesion and invasion, suggesting that MUC5AC might contribute to the invasive motility of pancreatic cancer cells by enhancing the expression of integrins, MMP-3, VEGF and activating Erk pathway.

Prognostic significance of the lymphocyte-to-monocyte ratio in patients with metastatic colorectal cancer

AIM To evaluate the prognostic significance of the lymphocyte to monocyte ratio (LMR) in patients with unresectable metastatic colorectal cancer who received palliative chemotherapy. METHODS A total of 104 patients with unresectable metastatic colorectal cancer who underwent palliative chemotherapy were enrolled. The LMR was calculated from blood samples by dividing the absolute lymphocyte count by the absolute monocyte count. Pre-treatment LMR values were measured within one week before the initiation of chemotherapy, while post-treatment LMR values were measured eight weeks after the initiation of chemotherapy. RESULTS The median pre-treatment LMR was 4.16 (range: 0.58-14.06). We set 3.38 as the cut-off level based on the receiver operating characteristic curve. Based on the cut-off level of 3.38, 66 patients were classified into the high pre-treatment LMR group and 38 patients were classified into the low pre-treatment LMR group. The low pre-treatment LMR group had a significantly worse overall survival rate (P = 0.0011). Moreover, patients who demonstrated low pre-treatment LMR and normalization after treatment exhibited a better overall survival rate than the patients with low pre-treatment and post-treatment LMR values. CONCLUSION The lymphocyte to monocyte ratio is a useful prognostic marker in patients with unresectable metastatic colorectal cancer who receive palliative chemotherapy.

Clinical and pathological features of five-year survivors after pancreatectomy for pancreatic adenocarcinoma

BackgroundClinical factors determining short-term survival after pancreatectomy have been well studied, but factors predicting long-term survival with curative resection are poorly understood in pancreatic carcinoma. Our objective was to identify clinical and pathological features of five-year disease-free survivors after surgical resection of pancreatic adenocarcinoma.MethodsThe clinical and pathological data from 147 patients who underwent a potentially curative resection for pancreatic adenocarcinoma at our institution between 1988 and 2012 were retrospectively analyzed.ResultsOf 147 patients, 18 survived for more than five years after surgery without disease recurrence. A univariate analyses demonstrated that: two or fewer lymph node metastases (P = 0.014), a preoperative serum carbohydrate antigen 19-9 (CA19-9) level of 40 U/mL or less (P = 0.0018), an absence of intrapancreatic nerve invasion (P = 0.028), and undergoing an R0 resection (P = 0.011) were significantly associated with five-year survival. A logistic regression model identified the following independent cancer-related predictors of five-year survivors: having two or fewer lymph node metastases (odds ratio (OR): 6.02; 95% confidence interval (CI): 1.08 to 112.98; P = 0.0385), a preoperative serum CA19-9 level of 40 U/mL or less (OR: 5.02; 95% CI: 1.68 to 16.48; P = 0.0036), and undergoing an R0 resection (OR: 3.63; 95% CI: 1.12 to 14.28; P = 0.0316).ConclusionsWe conclude that number of lymph node metastases being two or less, a preoperative serum CA19-9 level of 40 U/mL or less, and undergoing an R0 resection may be independent predictive factors to identify actual five-year survivors after pancreatectomy for pancreatic adenocarcinoma.

Gastric metastasis from renal cell carcinoma with gastrointestinal bleeding: a case report and review of the literature.

A 61-year-old man presented to our hospital with hypercalcemia and elevated C reactive protein (CRP). Evaluation revealed renal cell carcinoma (RCC) with metastasis to lung, bone, and brain. He underwent partial resection of the right kidney and a left nephrectomy. Histopathologic findings of resected tumors were consistent with clear cell RCC. Whole-brain irradiation was performed for management of brain metastasis. Postoperatively, he was treated with molecularly targeted therapy using a mammalian target of rapamycin inhibitor. Approximately 14 months later, he suffered an episode of upper gastrointestinal bleeding with secondary anemia and melena. Upper gastrointestinal endoscopy revealed a distinctly protruding lesion in the gastric body. Biopsy of the gastric lesion showed metastatic clear cell RCC. He underwent partial gastrectomy. His postoperative course was uneventful. However, 4 months after surgery, he died from brain metastasis. Metastatic RCC to the stomach, although rare, should be suspected in any patient with a history of RCC who presents with gastrointestinal symptoms.

Identification of HLA-A*0201- and A*2402-restricted epitopes of mucin 5AC expressed in advanced pancreatic cancer.

Objectives: Mucin 5AC (MUC5AC) was previously identified as being expressed in most pancreatic ductal adenocarcinomas. We studied the significance of MUC5AC expression for the development of pancreatic ductal adenocarcinoma and the possibility of using MUC5AC as a target for immunotherapy for pancreatic cancer. Methods: We immunohistochemicaly tested MUC5AC expression in 134 specimens. To assess the possibility of using the MUC5AC protein to develop an anticancer vaccine, we examined MUC5AC for possible peptide epitopes to elicit cytotoxic T lymphocytes (CTLs). Results: In immunohistochemical analysis, MUC5AC was absent from all cell types of the normal pancreas but was expressed de novo in 79% of invasive ductal adenocarcinoma. Clinicopathologically, primary tumors with lymph node metastasis had a significantly higher expression of MUC5AC. Next, we successfully established CTL clones stimulated by the MUC5AC-A02-1398 (FLNDAGACV) and MUC5AC-A24-716 (TCQPTCRSL) peptides, which have specific cytotoxicity against the corresponding HLA-A*0201- and A*2402-positive target cells pulsed with the candidate peptide. Each CTL clone also demonstrated its cytotoxic activity toward pancreatic cancer cells endogenously expressing MUC5AC. Conclusions: Our results suggest that MUC5AC is a novel tumor-associated antigen that has potential application as a vaccine against pancreatic cancer.Abbreviations: MUC5AC - mucin 5AC, CTL - cytotoxic T lymphocyte, HLA - human leukocyte antigen, MHC - major histocompatibility complex, MUC1 - mucin 1, mAb - monoclonal antibody, IFN - interferon, ELISpot - enzyme-linked immunospot

A case of bilateral pheochromocytoma during pregnancy

BackgroundPheochromocytoma is a disease where catecholamines are secreted. If pheochromocytoma occurs during pregnancy, it can be difficult to diagnose because it is similar to pregnancy-induced hypertension. Furthermore, bilateral pheochromocytoma during pregnancy is even rarer than unilateral pheochromocytoma.Case presentationA 32-year-old primigravida, who was 12 weeks’ pregnant, was aware of right abdominal discomfort. Masses in both adrenal glands were observed by abdominal ultrasonography. She was diagnosed with pheochromocytoma. Bilateral adrenalectomy was undertaken at 15 weeks’ gestation and she continued pregnancy. At 39 weeks’ gestation, a healthy male neonate was delivered. She was discharged on the 4th postpartum day.ConclusionsWe present a case of bilateral pheochromocytoma during pregnancy that was diagnosed in the first trimester. Differentiating pheochromocytoma from pregnancy-induced hypertension is important. Early diagnosis and appropriate blood pressure management with medical treatment followed by surgical removal of the tumor results in good maternal and fetal outcomes.

Doublecortin and CaM kinase-like-1 as an independent prognostic factor in patients with resected pancreatic carcinoma

AIM To elucidate the effect of expression of doublecortin and CaM kinase-like-1 (DCLK1) in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS Tumor specimens were obtained from 136 patients with pancreatic cancer who had undergone resection without preoperative therapy between January 2000 and December 2013 at the Department of Surgical Oncology, Osaka City University. The resected specimens were analyzed for associations with clinicopathological data, including DCLK1 expression, epithelial mesenchymal transition (EMT) marker expression, and cancer stem cell (CSC) marker expression. Univariate and multivariate survival analyses were performed and we assessed the association between DCLK1 expression and clinicopathological factors, including the EMT marker and CSC marker. RESULTS In total, 48.5% (66/136) of the pancreatic cancer samples were positive for DCLK1. Patients with DCLK1-positive tumors had significantly shorter survival times than those with DCLK1-negative tumors (median, 18.7 mo vs 49.5 mo, respectively; P < 0.0001). Positive DCLK1 expression correlated with histological grade (P = 0.0290), preoperative CA19-9 level (P = 0.0060), epithelial cell adhesion molecule (EpCAM) expression (P = 0.0235), and the triple-positive expression of CD44/CD24/EpCAM (P = 0.0139). On univariate survival analysis, five factors were significantly associated with worse overall survival: histological grade of G2 to G4 (P = 0.0091), high preoperative serum SPan-1 level (P = 0.0034), R1/2 (P < 0.0001), positive expression of DCLK1 (P < 0.0001) or CD44 (P = 0.0245). On multivariate survival analysis, R1/2 [odds ratio (OR) = 2.019, 95% confidence interval (CI): 1.380-2.933; P = 0.0004] and positive DCLK1 expression (OR = 1.848, 95%CI: 1.2854-2.661; P = 0.0009) were independent prognostic factors. CONCLUSION DCLK1 expression was found to be an independent prognostic factor and it may play a crucial prognostic role by promoting acquisition of stemness.

The impact of the preoperative peripheral lymphocyte count and lymphocyte percentage in patients with colorectal cancer.

PurposeWe evaluated the prognostic significance of the peripheral lymphocyte count and lymphocyte percentage, which reflect the preoperative immune status, in patients with colorectal cancer (CRC) and then compared their accuracy as predictors of the survival.MethodsWe retrospectively reviewed a database of 362 patients. We classified the patients into high lymphocyte count and low lymphocyte count groups. We also classified the patients into high lymphocyte percentage and low lymphocyte percentage groups.ResultsThe 5-year relapse-free survival (RFS) rate in the high lymphocyte count group tended to be higher than that in the low lymphocyte count group. The 5-year overall survival (OS) rate in the high lymphocyte count group was significantly higher than that in the low lymphocyte count group. In contrast, the 5-year RFS and OS rates in the high lymphocyte percentage group were both significantly higher than those in the low lymphocyte percentage group. A multivariate analysis showed that the lymphocyte percentage was independently associated with the OS.ConclusionsThese findings suggest that the lymphocyte percentage is a good predictor of the OS and may be a stronger predictor of survival than the lymphocyte count in CRC patients.

Giant duodenal ulcers after neurosurgery for brainstem tumors that required reoperation for gastric disconnection: a report of two cases

BackgroundDespite the efficacy of pharmacotherapy for gastrointestinal ulcers, severe cases of bleeding or perforation due to gastrointestinal ulcers still occur. Giant duodenal ulcer perforation is an uncommon but difficult-to-manage pathology with a high mortality rate. We report two cases of giant duodenal ulcer perforation after neurosurgery for brainstem tumors that needed reoperation for gastric disconnection because of postoperative leakage and bleeding.Case presentationBoth cases had undergone neurosurgery for brainstem tumors, and the patients were in a shock state for several days with peritonitis due to giant duodenal perforation. In Case 1, antrectomy with Billroth II reconstruction was performed. However, reoperation for gastric disconnection was needed because of major leakage of gastrojejunostomy and jejunojejunostomy. In Case 2, an omental patch, cholecystectomy, and insertion of a bile drainage tube from the cystic duct were performed for the giant duodenal ulcer, but leakage and bleeding from the ulcer edge required reoperation for gastric disconnection.ConclusionsBrainstem tumors in these cases might have been related to duodenal ulcer perforation with late diagnosis that progressed to severe sepsis. For giant duodenal ulcer perforation with poor general condition, simple closure including omental patch or antrectomy with reconstruction is hazardous. Antrectomy with gastric disconnection, meaning gastrostomy, duodenostomy, feeding jejunostomy and cholecystectomy, is recommended.