Little attention has been paid to colorectal xanthoma. To clarify the clinical and pathological features of colorectal xanthoma, we report 28 colorectal xanthomas biopsied from 25 patients. All were composed of typical xanthoma cells and showed polypoid configuration. Median age of the patients was 64 years and there were 15 men and 10 women. Diabetes mellitus, constipation, and hyperlipidemia were found in two, one, and seven patients, respectively. Seventeen (60.7%) of the 28 polyps were located in the sigmoid colon and the remaining 11 in the rectum. Twenty-three polyps (82.1%) were sessile. Twelve (60.0%) of twenty polyps that were recorded were reddish in color. Only two polyps revealed a yellowish tone. Microscopically, foamy cells were present in the lamina propria, but the submucosa did not contain foamy cells. Immunohistochemically, the foamy cells invariably expressed extensive positivity for CD68. The colonic glands showed a deformity in the case with moderate to intense density of the foamy cells. The surface epithelium showed a hyperplastic change in 22 (78.6%) xanthomas. The colonic glands in four xanthomas were also associated with hyperplastic changes. The basement membrane of the surface epithelium was often thickened. Cell debris and proliferation of the capillaries were observed just below the surface epithelium in 19 (67.9%) and 22 (78.6%) xanthomas, respectively. Previous mucosal minute injury was suggested as the pathogenesis of colorectal xanthomas. Colorectal xanthomas were not identical to gastric and esophageal xanthoma, endoscopically or microscopically. We prefer the term "xanthomatous polyp" rather than xanthoma in the colorectal region. They may be regarded as a novel type of colorectal non-neoplastic polyp.

The objective of this study was to evaluate the relation between the clinical and plasma parameters and the changes in plasma endotoxin activity with 2 hours of endotoxin-adsorbing therapy using polymyxin B (PMX). A total of 88 consecutive patients were admitted for PMX treatment of severe sepsis or septic organ failure. Standard supportive care was continued without alteration during PMX treatment. Endotoxin, tumor necrosis factor-alpha (TNFalpha), interleukin-6 (IL-6), IL-10, and plasminogen activator inhibitor-1 (PAI-1) activities and clinical parameters were measured before, immediately after, and the day after PMX treatment. The mean APACHE II and III scores were 24.2 +/- 1.0 and 85.8 +/- 3.0, respectively. The 2-week survival rate was 51.1%. In survivors, TNFalpha, IL-6, IL-10, and PAI-1 activities were significantly decreased during the 2-hour PMX treatment, the following day, or both times. There was no significant change in the parameters, except for TNFalpha, after PMX in nonsurvivors. In the subgroup whose plasma endotoxin decreased more than 30%, IL-6, TNFalpha, and PAI-1 significantly decreased after 2 hours of PMX or the following day (or both), but all four parameters in nonsurvivors showed no significant change. Hence PMX adsorbed plasma endotoxins and contributed to reductions in plasma proinflammatory cytokine levels and to improved clinical parameters during the 2-hour treatment. Changes in these parameters correlated with changes in plasma endotoxin activity in survivors whose plasma endotoxin levels were adequately reduced.

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.

Background:Sessile serrated adenomas/polyps (SSA/Ps) are a putative precursor of colon cancer with microsatellite instability (MSI). However, the developmental mechanism of SSA/P remains unknown. We performed genetic analysis and genome-wide DNA methylation analysis in aberrant crypt foci (ACF), SSA/P, and cancer in SSA/P specimens to show a close association between ACF and the SSA/P-cancer sequence. We also evaluated the prevalence and number of ACF in SSA/P patients.Methods:ACF in the right-side colon were observed in 36 patients with SSA/Ps alone, 2 with cancers in SSA/P, and 20 normal subjects and biopsied under magnifying endoscopy. B-RAF mutation and MSI were analysed by PCR–restriction fragment length polymorphism (RFLP) and PCR–SSCP, respectively, in 15 ACF, 20 SSA/P, and 2 cancer specimens. DNA methylation array analysis of seven ACF, seven SSA/P, and two cancer in SSA/P specimens was performed using the microarray-based integrated analysis of methylation by isochizomers (MIAMI) method.Results:B-RAF mutations were frequently detected in ACF, SSA/P, and cancer in SSA/P tissues. The number of methylated genes increased significantly in the order of ACF

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. .