Takahiro Goji

High antitumor activity of pladienolide B and its derivative in gastric cancer

The antitumor activity of pladienolide B, a novel splicing inhibitor, against gastric cancer is totally unknown and no predictive biomarker of pladienolide B efficacy has been reported. We investigated the antitumor activity of pladienolide B and its derivative on gastric cancer cell lines and primary cultured cancer cells from carcinomatous ascites of gastric cancer patients. The effect of pladienolide B and its derivative on six gastric cancer cell lines was investigated using a MTT assay and the mean IC50 values determined to be 1.6 ± 1.2 (range, 0.6–4.0) and 1.2 ± 1.1 (range, 0.4–3.4) nM, respectively, suggesting strong antitumor activity against gastric cancer. The mean IC50 value of pladienolide B derivative against primary cultured cells from 12 gastric cancer patients was 4.9 ± 4.7 nM, indicative of high antitumor activity. When 18 SCID mice xenografted with primary cultured cells from three patients were administered the pladienolide B derivative intraperitoneally, all tumors completely disappeared within 2 weeks after treatment. Histological examination revealed a pathological complete response for all tumors. In the xenograft tumors after treatment with pladienolide B derivative, immature mRNA were detected and apoptotic cells were observed. When the expressions of cell‐cycle proteins p16 and cyclin E in biopsied gastric cancer specimens were examined using immunohisctochemistry, positivities for p16 and cyclin E were significantly and marginally higher, respectively, in the low‐IC50 group compared with the high‐IC50 group, suggesting the possibility that they might be useful as predictive biomarkers for pladienolide B. In conclusion, pladienolide B was very active against gastric cancer via a mechanism involving splicing impairment and apoptosis induction.

Biomarkers for predicting the efficacy of anti-epidermal growth factor receptor antibody in the treatment of colorectal cancer.

Anti-epidermal growth factor receptor (EGFR) antibodies have been widely utilized as a standard treatment for metastatic colorectal cancer (CRC). Anti-EGFR antibodies bind competitively to EGFRs to inhibit receptor activation and subsequent signal transduction of the RAS/RAF/MEK pathway and PI3K/AKT pathway. By inhibiting EGFR-mediated signal transduction, anti-EGFR antibodies inhibit cell growth, invasion, metastasis and angiogenesis, and they induce apoptosis. The IgG1-type antibody cetuximab is also capable of inducing antibody-dependent cellular cytotoxicity. Several studies have shown that KRAS mutation is a useful biomarker for predicting the efficacy of anti-EGFR agents, and the major guidelines for the treatment of CRC recommend the use of anti-EGFR antibody only for the cancers with wild-type KRAS. Alterations of other genes, including BRAF, NRAS, PTEN and AKT, and EGFR expression/gene copy number have also been reported to be candidate biomarkers for predicting the efficacy of anti-EGFR agents. The predictive values of these biomarkers are still controversial and further investigations are required.

Serum diamine oxidase activity as a predictor of gastrointestinal toxicity and malnutrition due to anticancer drugs.

Objective evaluation of intestinal mucosal damage due to anticancer drugs is generally difficult. Serum diamine oxidase (DAO) activity is reported to reflect the integrity and maturity of the small intestinal mucosa. Therefore, we investigated whether serum DAO activity is an indicator of gastrointestinal toxicity or nutritional status in patients receiving chemotherapy.

Suppressive effect of RAS inhibitor manumycin A on aberrant crypt foci formation in the azoxymethane-induced rat colorectal carcinogenesis model.

The chemopreventive effect of RAS inhibitors on colorectal cancer is unknown. Because aberrant crypt foci (ACF), earliest preneoplastic lesions, are highly positive for K‐RAS mutation, RAS inhibitors are likely to be effective for chemoprevention. Therefore, in the present study, the suppressive effect of a RAS inhibitor, manumycin A, on ACF formation in an azoxymethane (AOM)‐induced rat colorectal carcinogenesis model was investigated.

Hemosuccus pancreaticus caused by a mucinous cystic neoplasm of the pancreas

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.

The differing influence of several factors on the development of fatty liver with elevation of liver enzymes between genders with metabolic syndrome: A cross-sectional study

Background Nonalcoholic fatty liver disease (NAFLD) is known to be strongly associated with obesity, visceral fat, metabolic syndrome (MS), lifestyle, and lifestyle-related diseases in both males and females. However, the prevalence of NAFLD, MS, and clinical backgrounds is different between males and females. Objective We conducted a cross-sectional study to examine the differing influence of lifestyle-related factors and visceral fat on fatty liver (FL) with elevation of liver enzymes between males and females with MS. Methods We enrolled 42,134 persons who underwent a regular health check-up, and after excluding subjects who fulfilled excluding criteria, the remaining subjects were 2,110 persons with MS. We examined the differing influence of lifestyle-related factors and visceral fat on FL with elevation of alanine aminotransferase (ALT) (ALT elevation was defined as ALT level of ≥31 IU/l in the present study). Results The odds rations for FL with ALT elevation were as follows: WC, 1.83 (95% confidence interval (CI) 1.36–2.46); dyslipidemia, 1.89 (95% CI 1.34–2.68); hemoglobin A1c, 1.36 (95% CI 1.00–1.85); visceral fat type MS (V-type MS), 5.78 (95% CI 4.29–7.80); and light drinker, 0.56 (95% CI 0.41–0.78) in males with MS and BMI, 2.18 (95% CI 1.43–3.33); WC, 1.85 (95% CI 1.27–2.70); diastolic blood pressure, 1.69 (95% CI 1.16–2.45); triglyceride, 2.22 (95% CI 1.56–3.17); impaired glucose tolerance, 1.66 (95% CI 1.11–2.47); and V-type MS, 3.83 (95% CI 2.57–5.70) in females with MS. The prevalence of FL with ALT elevation and ALT was significantly higher in V-type MS than in the subcutaneous fat type MS in both males and females with MS (P < 0.001). Conclusion Although V-type MS and WC is a common significant predictor of an increased prevalence of FL with ALT elevation in both males and females with MS, gender, lifestyle-related factors, and MS type in individuals with MS should be considered for the development of FL with ALT elevation.

EGFR Downregulation after Anti-EGFR Therapy Predicts the Antitumor Effect in Colorectal Cancer

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 RAS, BRAF 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. Implications: 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. Mol Cancer Res; 15(10); 1445–54. ©2017 AACR.

Pedunculated duodenal carcinoid successfully removed by endoscopic resection with endoloop

Duodenal carcinoids are rare tumors, the natural history of which has not yet been clearly clarified. Endoscopic resection is recommended for tumors of less than 1 cm in diameter, limited to the submucosal layer and with a low incidence of lymph node or distant metastases, although no consensus on this recommendation has been reached yet. Several techniques have been reported, including endoscopic submucosal dissection (ESD), strip biopsy and band ligation technique. In this study we report a case of pedunculated duodenal carcinoid which was successfully removed by endoscopic resection with an endoloop.

Tu1683 Expression of Thymidine Phosphorylase in Ulcerative Colitis and Efficacy of Its Specific Inhibitor for the Treatment of Ulcerative Colitis

protein were collected. Cytokine levels in cell supernatants were determined using the Bioplex 3D suspension array system (Bio-Rad). Preadipocyte supernatants were also applied on cultures of human colonic NCM-460 cells for 24hs and RNA and protein were collected. Inflammatory molecule mRNA expression and activation of intracellular kinases were evaluated with Luminex inflammatory panels (FlexScript LDA), and phospho-protein multiplex panels, respectively. Results: Preadipocytes isolated from IBD patients demonstrated differential mediator secretion patterns compared to preadipocytes from control and obese patients. Of the 42 proinflammatory cytokines and growth factors tested, IL-7/IL-8/Gro/MCP3/VEGF/ PDGF-AA showed statistically significant differences between control, obese and IBD preadipocytes (p ,0.05). Notably, there were significant differences in mediator secretion between preadipocytes isolated from UC and CD patients, in particular VEGF and PDGF (p , 0.01 for both). NCM-460 cells had distinct GSK-3, AKT kinase activation (p , 0.05 for both) and cytokine mRNA expression patterns of TNF, IL-2, IL-3, IL-17, VEGF, MIP-1 β, MIP-3, RANTES (p,0.05) following exposure to preadipocyte supernatants from all three pathological conditions compared to controls. Conclusions: Our data suggest the existence of preadipocyte-disease-dependent mediators contributing to the generation of differential colonocyte responses. Together with reports indicating altered levels of several adipokines during IBD, our results provide the first direct evidence for the importance of adipose tissue homeostasis during obesity in determining the outcome of IBD. Supported by NIH P50 DK064539 (CP & IK), DK047343, DK060729 (CP), The Broad Foundation (BMRP) (IK, RA), and the Blinder Research Foundation for Crohns Disease (AS).