CpG Island Methylator Phenotype in Primary Gastric Carcinoma

Gastric cancers (GC) with methylation of multiple CpG islands have a CpG island methylator phenotype (CIMP) and they can have different biological features. The aim of this study was to investigate the DNA methylation status of GCs and its association with their clinicopathological features. We evaluated the methylation status of four genes (MINT1, MINT2, MINT25 and MINT31) in 105 primary GCs using bisulfite-pyrosequencing analysis. We classified tumors as CIMP-high (CIMP-H), CIMP-low (CIMP-L) or CIMP-negative (CIMP-N) based on the methylation of MINT1, MINT2, MINT25, and MINT31. Overall, the prevalence of CIMP-H, CIMP-L and CIMP-N was 22% (23/105), 52% (55/105) and 26% (27/105), respectively. We observed a significant difference in tumor stage (stages I-II vs. stages III-IV) between CIMP-H and CIMP-N tumors (P = 0.0435). No significant differences were observed in clinicopathological characteristics (gender, age, location and tumor differentiation) among the CIMP phenotypes. The prognoses of patients with a CIMP-H tumor is likely to be better than those with CIMP-L or CIMP-N tumors, but these differences are not statistically significant (P = 0.074 and P = 0.200). Our results suggest that CIMP may define a subgroup of GCs with distinct biological features

簡便な成熟ブタ膵内分泌細胞分離法の検討

膵細胞移植に際しては,大量かつ高純度の膵内分泌細胞を得ることが重要である.本研究では,リンパ球分離溶液を用いた簡便な成熟ブタ膵内分泌細胞の分離法を検討した.屠殺場より入手した成熟ブタ膵を細切・攪拌した後,細胞懸濁液を遠心分離し単離肝細胞を収集した.これをリンパ球分離溶液であモノポリ分離溶液(mono-poly resolving medium: MPRM)を用いて,膵内分泌細胞を外分泌細胞および血管内皮細胞,血液細胞などより分離・精製した.得られた膵分泌細胞数を計測し,形態学的・機能的観察を行った.その結果,(1)得られた膵内分泌細胞数:3.40±1.32×10^5/gのうち,ジチゾン染色陽性細胞数は2.81±1.09×10^5/gで,純度は82.6±2.5%であった.(2)免疫組織化学染色では60%がB細胞であった.(3)電顕では,典型的な分泌顆粒を有するB細胞,A細胞が認められた.(4)グルコース負荷試験では,分離直後のインスリン分泌能低下は1週間の培養で改善し,また40日間の培養中インスリンの分泌が保たれた.成熟ブタ膵内分泌細胞径は,ヒトリンパ球径に類似しており,MPRMを用いた1回の遠心操作で,膵分泌細胞は明瞭に分離され安定した細胞数が得られた.また,膵内分泌細胞の構成は膵島におけるそれと類似しており,超微細構造も保たれていた.以上より,MPRMを用いた膵内分泌細胞の分離法は,簡便で安定した細胞数が得られ,その形態・機能とも良好で有用な方法であると考えられた.Adult pig pancreatic endocrine cells were harvested by auto-digestion without added enzymes. The isolated, crude cells were purified by Mono-poly resolving medium (MPRM). The purity of the harvested cells was determined by dithizone staining and the number of pancreatic endocrine cells was counted. A large number of the cells were stained red with dithizone and showed high viability and a good insulin secretory response to glucose stimulation. The average number of cells purified by MPRM was 3.40 ± 1.32 × 10^5 cells/g pancreas and the number of dithizone-stained cells was 2.81 ± 1.09 × 10^5 cells/g pancreas. The insulin secretion from the pancreatic endocrine cells was maintained throughout a 40-day observation period and high glucose stimulation induced an increase in insulin secretion from the cultured cells. In the cells purified by MPRM, light and electron microscopic studies showed the cells to be typical pancreatic endocrine cells. The present purification method using MPRM allowed us to obtain quickly a large amount of adult pig pancreatic endocrine cells from the unpurified preparations. This is useful for transplantation and biochemical or biological studies of adult pig pancreatic endocrine cells

簡便な成熟ブタ膵内分泌細胞分離法の検討

膵細胞移植に際しては,大量かつ高純度の膵内分泌細胞を得ることが重要である.本研究では,リンパ球分離溶液を用いた簡便な成熟ブタ膵内分泌細胞の分離法を検討した.屠殺場より入手した成熟ブタ膵を細切・攪拌した後,細胞懸濁液を遠心分離し単離肝細胞を収集した.これをリンパ球分離溶液であモノポリ分離溶液(mono-poly resolving medium: MPRM)を用いて,膵内分泌細胞を外分泌細胞および血管内皮細胞,血液細胞などより分離・精製した.得られた膵分泌細胞数を計測し,形態学的・機能的観察を行った.その結果,(1)得られた膵内分泌細胞数:3.40±1.32×10^5/gのうち,ジチゾン染色陽性細胞数は2.81±1.09×10^5/gで,純度は82.6±2.5%であった.(2)免疫組織化学染色では60%がB細胞であった.(3)電顕では,典型的な分泌顆粒を有するB細胞,A細胞が認められた.(4)グルコース負荷試験では,分離直後のインスリン分泌能低下は1週間の培養で改善し,また40日間の培養中インスリンの分泌が保たれた.成熟ブタ膵内分泌細胞径は,ヒトリンパ球径に類似しており,MPRMを用いた1回の遠心操作で,膵分泌細胞は明瞭に分離され安定した細胞数が得られた.また,膵内分泌細胞の構成は膵島におけるそれと類似しており,超微細構造も保たれていた.以上より,MPRMを用いた膵内分泌細胞の分離法は,簡便で安定した細胞数が得られ,その形態・機能とも良好で有用な方法であると考えられた.Adult pig pancreatic endocrine cells were harvested by auto-digestion without added enzymes. The isolated, crude cells were purified by Mono-poly resolving medium (MPRM). The purity of the harvested cells was determined by dithizone staining and the number of pancreatic endocrine cells was counted. A large number of the cells were stained red with dithizone and showed high viability and a good insulin secretory response to glucose stimulation. The average number of cells purified by MPRM was 3.40 ± 1.32 × 10^5 cells/g pancreas and the number of dithizone-stained cells was 2.81 ± 1.09 × 10^5 cells/g pancreas. The insulin secretion from the pancreatic endocrine cells was maintained throughout a 40-day observation period and high glucose stimulation induced an increase in insulin secretion from the cultured cells. In the cells purified by MPRM, light and electron microscopic studies showed the cells to be typical pancreatic endocrine cells. The present purification method using MPRM allowed us to obtain quickly a large amount of adult pig pancreatic endocrine cells from the unpurified preparations. This is useful for transplantation and biochemical or biological studies of adult pig pancreatic endocrine cells

Clinicopathological and Molecular Features of Laterally Spreading Tumors

Colorectal flat-elevated neoplasms can be classified into small-flat adenoma and laterally spreading tumors (LSTs), which can then be sub-categorized into granular-type (LST-G) and nongranular-type (LST-NG) LSTs with possible biological differences between them. We evaluated clinicopathological features and KRAS / BRAF mutations in 24 LST-Gs and 57 LST-NGs. PCR-based pyrosequencing assays were used to determine the presence of activating mutations in codons 12 and 13 of KRAS and in codon 600 of BRAF. Significant differences between LST-Gs and LST-NGs were observed in tumor size (30mm vs. 15mm, P<0.0001) and the frequency of KRAS mutations (75%, 18/24 vs. 5%, 3/57, P< 0.0001). For LST-NGs, the histological grade was increased with an increase in the tumor size. The frequency of submucosal cancer (SM-ca) was also higher in tumors of at least 20mm than in tumors smaller than 20mm (P<0.05). In contrast, there was no indication of a size-dependent increase in the histological grade. No significant difference in the frequency of KRAS mutation in LST-Gs and LST-NGs was related to tumor size. Two subtypes of LSTs were observed to have different clinicopathological and molecular characteristics. These findings suggest that different molecular mechanisms could exist in these subtypes of colorectal flat-type neoplasms

Baseline soluble MICA levels act as a predictive biomarker for the efficacy of regorafenib treatment in colorectal cancer

International audienceBackground: To evaluate the effect of regorafenib on soluble MHC class I polypeptide-related sequence A (MICA) (sMICA) level in vitro. In addition, we clinically examined whether its plasma levels were associated with regorafenib activity in terms of progression-free survival (PFS) in patients with CRC. Methods: Human CRC cell line HCT116 and HT29 cells were treated with regorafenib and its pharmacologically active metabolites, M2 or M5 at the same concentrations as those in sera of patients. We also examined the sMICA levels and the area under the plasma concentration-time curve of regorafenib, M2 and M5. Results: Regorafenib, M2, and M5 significantly suppressed shedding of MICA in human CRC cells without toxicity. This resulted in the reduced production of sMICA. In the clinical examination, patients with CRC who showed long median PFS (3.7 months) had significantly lower sMICA levels than those with shorter median PFS (1.2 months) (p = 0.045). Conclusions: MICA is an attractive agent for manipulating the immunological control of CRC and baseline sMICA levels could be a predictive biomarker for the efficacy of regorafenib treatment