Anti-EGFR mAb is reported to induce EGFR internalization in colorectal cancer cells. However, the biological relevance of EGFR internalization with anti-EGFR mAb is unknown. Therefore, the relevance of EGFR downregulation with anti-EGFR mAb to antitumor activity in colorectal cancer cells was investigated. Quantification of EGFR on the cell surface before cetuximab treatment was assessed by flow cytometry, and its growth-inhibitory effects were measured by Trypan blue exclusion, in 10 wild-type colorectal cancer cell lines, but there was no significant correlation between EGFR number and its growth-inhibitory effect. However, a significant correlation existed between the percentage decrease in the number of EGFRs after cetuximab treatment and its growth-inhibitory effect in those cell lines. Treatment with TGFα, a ligand for EGFR, induced EGFR internalization in colorectal cancer cells, but most EGFRs subsequently recycled to the cell surface, consistent with previous studies. While cetuximab treatment induced EGFR internalization, most receptors subsequently translocated into the late endosome, leading to lysosomal degradation, as revealed by immunoblotting and double immunofluorescence. Cetuximab-sensitive colorectal cancer cells showed greater EGFR internalization, stronger cell growth inhibition, and more augmented apoptotic signals than nonsensitive cells. IHC for EGFR, performed using an EGFR pharmDx Kit (mouse anti-human EGFR mAb clone 2-18C9), in clinical specimens before and after anti-EGFR mAb therapy in 13 colorectal cancer patients showed a significant correlation between the response to anti-EGFR mAb and decreased staining after therapy. This report clearly demonstrates that anti-EGFR mAb facilitates internalization and subsequent degradation of EGFRs in lysosomes, which is an important determinant of the efficacy of anti-EGFR mAb treatment for colorectal cancer. .

Background/Aims: Gastric xanthomas are frequently observed in the stomach as small yellowish plaques or nodules. A close relationship among Helicobacter pylori infection, atrophic gastritis, and xanthomas has been reported. We assessed the clinicopathological features of gastric cancer with or without xanthomas. Methods: A total of 91 patients who were diagnosed as having early gastric cancer were enrolled. We evaluated the gastritis status using scores for gastritis and atrophy, positivity of H. pylori infection, the prevalence rate of xanthomas, and the clinicopathological features of gastric cancer. Results: Gastric xanthomas were observed in 72.5% of early gastric cancer cases. Scores for gastritis and atrophy were significantly higher in the xanthoma-positive group than those in the xanthoma-negative group. A higher prevalence of differentiated-type adenocarcinoma was found in the xanthoma-positive group. Among the cases with multiple gastric xanthomas, the prevalence of males was significantly higher than that of females. Conclusion: A high prevalence rate of gastric xanthomas in gastric cancer cases was shown. Xanthomas were highly associated with age, the severities of gastritis and atrophy, and differentiated-type adenocarcinoma. Regardless of the eradication of H. pylori, xanthomas may be useful predictive markers for the development of differentiated-type adenocarcinoma.

BackgroundAlthough many patients still have anxiety about upper gastrointestinal (GI) endoscopy, there have been few reports on the influence of distractions for a person who is going to undergo upper GI endoscopy soon. This study was a prospective randomized controlled study investigating the influence of distractions, such as auditive and visual distractions using subjective and objective assessments including autonomic nervous function prior to upper GI endoscopy.Methods206 subjects who underwent upper GI endoscopy as regular health check-ups were divided randomly into 4 groups prior to upper GI endoscopy; group 1 (control group), group 2 (auditive group), group 3 (visual group), and group 4 (combination group). We measured vital signs, autonomic nervous function, profile of mood state (POMS), and the impression for upper GI endoscopy pre- and post-distraction in the 4 groups.ResultsThere was no significant difference in vital signs between 5 and 15 min after sitting in group 1, however, several vital signs in all distraction groups improved significantly after distraction (Pulse rate (P): p <  0.001 in group 4; blood pressure: p <  0.05 in group 2, 3, 4) and the rate of decrease in P and diastolic blood pressure was highest in group 4 (p <  0.001). Several scores of POMS and the impression for upper GI endoscopy post-distraction improved significantly compared to pre-distraction between distraction groups and the satisfaction for distraction was highest in group 4 (p <  0.01). Regarding autonomic nerve function, the low- frequency power/ high- frequency power ratio post-distraction was significantly lower than that pre-distraction in all distraction groups (p <  0.001).ConclusionsAlthough auditive distraction alone and visual distraction alone were effective, a combination distraction was more effective than any other distraction by subjective and objective assessments. These distractions, which were simple and safe, may play an assistive role in the stability of physical and psychological conditions prior to upper GI endoscopy.Trial registrationThis trial was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry as UMIN000022801. Registered on 10 July 2016.

Neuroendocrine carcinoma (NEC) of the pancreas is very rare, and its origin is not fully elucidated. Here, we present a case of a small-size NEC of the pancreas that is genetically similar to invasive ductal adenocarcinoma (IDA). A 65-year-old man was referred to our hospital due to obstructive jaundice and found to have a 12-mm solid tumor in the pancreas head. The tumor exhibited low vascularity on enhanced computed tomography, and endoscopic retrograde pancreatographic imaging revealed an irregular obstruction in a branch duct of the pancreas. The patient was thereby diagnosed with a pancreatic ductal cancer, and stomach-preserving pancreaticoduodenectomy with regional lymph node resection was performed. Histochemical analysis of the resected tumor showed that the neoplastic cells with scanty cytoplasm and hyperchromatic nuclei strongly expressed chromogranin A and synaptophysin. The Ki-67 index was 40 % in the most proliferative tumor regions, and the tumor was diagnosed as a NEC of the pancreas. However, in the analysis of genetic alterations of the tumor tissue, the neoplastic cells showed altered KRAS, TP53, and SMAD4/DPC4, suggesting that the NEC in our case is genetically related to IDA. Our data suggest that poorly differentiated IDAs may transform into NECs.

Hemosuccus pancreaticus is a gastrointestinal hemorrhage through the main pancreatic duct. Here, we report a rare case of hemosuccus pancreaticus due to a mucinous cystic neoplasm of the pancreas. A 62-year-old woman who had been followed for a branch duct intraductal papillary mucinous neoplasm visited our emergency room due to severe abdominal pain and bloody discharge. Computed tomography revealed that the pancreatic cyst increased the tension of the wall and a high-density area indicative of bleeding into the cyst was observed. Endoscopy showed opening of and hemorrhaging from the papilla of Vater. The patient was diagnosed with hemosuccus pancreaticus caused by hemorrhaging into the cyst from the branch duct intraductal papillary mucinous neoplasm. Based on this diagnosis, elective distal pancreatectomy was performed. The histopathological diagnosis was a mucinous cystic neoplasm with intermediate-grade dysplasia based upon the pathological findings that fibrous ovarian-type stroma existed abundantly and the stroma cells were positive for progesterone receptor and inhibin. Hemosuccus pancreaticus caused by a mucinous cystic neoplasm is extremely rare and there has been only one case reported to date. In conclusion, it should be recognized that pancreatic cystic neoplasms including mucinous cystic neoplasms may cause hemosuccus pancreaticus.