Jun Higashijima

Sonic hedgehog relates to colorectal carcinogenesis

AimThe activation of Hedgehog signaling, which is critical to normal mammalian gastrointestinal development, is implicated in the development of various tumors, including colorectal cancer. In the pancreas, a precursor lesion overexpresses the Sonic hedgehog (Shh) when compared with normal tissue and cancer. The present study was designed to investigate Shh related protein expression in hyperplastic polyps and the adenoma-carcinoma sequence in the colon and rectum.MethodsSeventeen hyperplastic polyps, 24 adenomas of the colon, 69 adenocarcinomas (31 well-differentiated, 38 moderately-differentiated), and 30 normal colon samples were used in the study. We checked the expression of Shh, both patched (Ptch) and smoothened (Smo), by immunohistochemistry and compared the expression rate of each group.ResultsAlmost all adenomas, 22 of 23 (96%), expressed Shh. In other groups, 4 of 17 hyperplastic polyps (24%), 7 of 31 well-differentiated adenocarcinomas (23%), 13 of 38 moderately-differentiated adenocarcinomas (34%) and none of the 30 normal samples expressed Shh. The rate of expression in Ptch and Smo gradually increased in accordance with tumor progression.ConclusionThis result indicates that Shh-related carcinogenesis and Shh expression may be a trigger for the adenoma-carcinoma sequence. This study suggests a potential therapeutic target of hedgehog blockade in carcinogenesis.

Expression of histone deacetylase 1 and metastasis-associated protein 1 as prognostic factors in colon cancer

Histone deacetylase 1 (HDAC1) and metastasis-associated protein 1 (MTA1) form the nucleosome remodeling and histone deacetylation (NuRD) complex and may possibly play a central role in cancer development. However, limited data has been reported regarding the expression of both HDAC1 and MTA1. The aim of the present study was to clarify the clinical role of HDAC1 and MTA1 expression in colon cancer. Seventy-four patients with colon cancer, who underwent colectomy at our institution, were enrolled in this study. Expression of HDAC1 and MTA1 was examined immunohistochemically. The patients were divided into four groups: HDAC1-positive group (n=58), HDAC1-negative group (n=16), MTA1-positive group (n=38) and MTA1-negative group (n=36). Clinicopathological factors and survival rates were compared between the groups. Regarding the clinicopathological factors, the depth of tumor invasion and stage correlated significantly with HDAC1 expression (p<0.05). Age, depth of tumor invasion and vascular invasion tended to correlate with MTA1 expression. The 5-year survival rate in the HDAC1-positive group (55.1%) was significantly worse compared to the HDAC1-negative group (86.5%) (p<0.05), and the 5-year survival rate of the MTA1-positive group (50.5%) was significantly worse than that of the MTA1-negative group (73.1%) (p=0.05). In patients with stages II-IV and curability A, B, the survival rate in those with HDAC1-positive expression was significantly worse than those with HDAC1-negative expression (p<0.05), and the survival rate of the MTA1-positive group tended to be worse than that of the MTA1-negative group (p=0.07). Overall survival in both the HDAC1 and MTA1-positive groups was significantly worse than overall survival of the other groups (p<0.05). Disease-free survival in both the HDAC1- and MTA1-positive groups, among patients with stages II-IV and curability A, B, was also significantly worse than that of the other groups (p<0.05). HDAC1 and MTA1 expression levels were significantly related to poorer prognosis. Therefore, HDAC1 and MTA1 expression levels are potential prognostic indicators for colon cancer.

Characteristics of internal hernia after gastrectomy with Roux-en-Y reconstruction for gastric cancer.

BackgroundAlthough the internal hernias have been a huge topic in the field of bariatric surgery, there were a few reports in gastric cancer. The purpose of this study was to analyze the incidence, clinical features, and prevention of internal hernia after gastrectomy for gastric cancer.MethodsTwelve patients who underwent surgical treatment for internal hernia in our hospital after gastrectomy were analyzed. Features, including incidence, symptoms, and signs, were investigated in detail.ResultsThe operative procedures for preceding gastrectomies were open distal gastrectomy in three patients, open total gastrectomy in three patients, laparoscopic-assisted distal gastrectomy in two patients, and laparoscopic total gastrectomy in four patients. The most frequent sites of internal hernias were jejunojejunostomy mesenteric defects (five patients) and Petersen’s defect (five patients), mesenterium of transverse colon (one patient), and esophagus hiatus (one patient). There was no significant difference between open and laparoscopic preceding gastrectomies. After closure of the mesenteric defect was introduced, no further internal hernias occurred. On CT examination, the whirl sign was present in ten patients on 3D images.ConclusionsThe present data suggest the importance of early recognition and treatment of internal hernia, as well as its prevention by closure of mesenteric defects.

Platelet-derived endothelial cell growth factor/thymidine phosphorylase inhibitor augments radiotherapeutic efficacy in experimental colorectal cancer

PURPOSES A lot of radiosensitizers have been developed. However, there are few to be available in the clinical setting. Thymidine phosphorylase inhibitor (TPI) regulates the phosphorolysis of thymidine to thymine and 2-deoxy-d-ribose-1-phosphate which is essential for tumor angiogenesis. The aim of this study is to evaluate whether TPI augments the radiotherapy for colorectal cancer in vitro and in vivo studies. MATERIALS AND METHODS The cytotoxicity of TPI with irradiation on HT29 and HCT116 cells was examined using MTT- and colony formation assay. At 10days post-inoculation, HT29 bearing orthotopic model mice (n=28) were divided into four groups and orally treated with TPI- (50mg/kg/day for 2weeks), radiation (RT, 2Gy×4: Total 8Gy), their combination or the vehicle. The mechanisms underlying the efficacy were assessed genomically and immunohistochemically. RESULTS Compared to each single treatment, the combination of TPI and RT synergistically inhibited the cell viability in a time- and dose-dependent manner. In the HT-29 bearing mice, the combination of TPI and RT reduced the tumor growth compared with RT alone. Notably, the mRNA levels of VEGF, TGF-β and, Rad51 and the protein expressions of VEGF and CD34 were significantly lower in the combination than the others. Furthermore, the combination markedly increased the TUNEL-positive cells, suggesting that TPI augments the cancer cell death through inhibition of angiogenesis and DNA repair system in the radiotherapy. CONCLUSIONS Our study first demonstrated that the combination of TPI and irradiation was effective in colon cancer. TPI would provide a promising therapeutic strategy as a radiosensitizer.

Duodenal–jejunal bypass improves diabetes and liver steatosis via enhanced glucagon‐like peptide‐1 elicited by bile acids

Bariatric surgery not only elicits weight loss but also rapidly resolves diabetes. However, the mechanisms remain unclear. The present study investigates how diabetes and liver steatosis are improved after duodenal–jejunal bypass (DJB) compared with a glucagon‐like peptide‐1 (GLP‐1) analog and correlations between bile acids and GLP‐1 secretion.

Squamous Cell Carcinoma of the Descending Colon: Report of a Case and Literature Review

It is very rare that squamous cell carcinoma (SCC) arises from colorectal epithelium. An 89-year-old man was treated in 2001 with chief complaints of anorexia, abdominal pain, and low grade fever. The histological diagnosis as SCC was determined by biopsy during a colonoscopy. We diagnosed primary SCC of the colon because except in the colon no malignant lesions were found by systemic CT. Surgical complete resection was performed. However, he died three months after surgical resection because of hepatic metastasis and cachexia. The prognosis of this disease seems to be worse than that of adenocarcinoma.

Downregulation of microRNA-100/microRNA-125b is associated with lymph node metastasis in early colorectal cancer with submucosal invasion

A majority of early colorectal cancers (CRCs) with submucosal invasion undergo surgical operation, despite a very low incidence of lymph node metastasis. Our study aimed to identify microRNAs (miRNAs) specifically responsible for lymph node metastasis in submucosal CRCs. MicroRNA microarray analysis revealed that miR‐100 and miR‐125b expression levels were significantly lower in CRC tissues with lymph node metastases than in those without metastases. These results were validated by quantitative real‐time PCR in a larger set of clinical samples. The transfection of a miR‐100 or miR‐125b inhibitor into colon cancer HCT116 cells significantly increased cell invasion, migration, and MMP activity. Conversely, overexpression of miR‐100 or miR‐125b mimics significantly attenuated all these activities but did not affect cell growth. To identify target mRNAs, we undertook a gene expression array analysis of miR‐100‐silenced HCT116 cells as well as negative control cells. The Ingenuity Pathway Analysis, TargetScan software analyses, and subsequent verification of mRNA expression by real‐time PCR identified mammalian target of rapamycin (mTOR) and insulin‐like growth factor 1 receptor (IGF1R) as direct, and Fas and X‐linked inhibitor‐of‐apoptosis protein (XIAP) as indirect candidate targets for miR‐100 involved in lymph node metastasis. Knockdown of each gene by siRNA significantly reduced the invasiveness of HCT116 cells. These data clearly show that downregulation of miR‐100 and miR‐125b is closely associated with lymph node metastasis in submucosal CRC through enhancement of invasion, motility, and MMP activity. In particular, miR‐100 may promote metastasis by upregulating mTOR, IGF1R, Fas, and XIAP as targets. Thus, miR‐100 and miR‐125b may be novel biomarkers for lymph node metastasis of early CRCs with submucosal invasion.

Role of thrombospondin-1 expression in colorectal liver metastasis and its molecular mechanism.

Thrombospondin‐1 (THBS‐1), a glycoprotein, is an endogenous inhibitor of angiogenesis and tumor growth. In this study, we investigated the clinical role and mechanism of THBS‐1 expression in colorectal liver metastases, focusing on the relationships between its expression and tumor growth, epithelial‐mesenchymal transition (EMT), and expression of other relevant molecules.

Prediction of response to preoperative chemoradiotherapy and establishment of individualized therapy in advanced rectal cancer.

Preoperative chemoradiotherapy (CRT) has become the standard treatment for patients with locally advanced rectal cancer. However, no specific biomarker has been identified to predict a response to preoperative CRT. The aim of the present study was to assess the gene expression patterns of patients with advanced rectal cancer to predict their responses to preoperative CRT. Fifty-nine rectal cancer patients were subjected to preoperative CRT. Patients were randomly assigned to receive CRT with tegafur/gimeracil/oteracil (S-1 group, n=30) or tegafur-uracil (UFT group, n=29). Gene expression changes were studied with cDNA and miRNA microarray. The association between gene expression and response to CRT was evaluated. cDNA microarray showed that 184 genes were significantly differentially expressed between the responders and the non‑responders in the S-1 group. Comparatively, 193 genes were significantly differentially expressed in the responders in the UFT group. TBX18 upregulation was common to both groups whereas BTNL8, LOC375010, ADH1B, HRASLS2, LOC284232, GCNT3 and ALDH1A2 were significantly differentially lower in both groups when compared with the non-responders. Using miRNA microarray, we found that 7 and 16 genes were significantly differentially expressed between the responders and non-responders in the S-1 and UFT groups, respectively. miR-223 was significantly higher in the responders in the S-1 group and tended to be higher in the responders in the UFT group. The present study identified several genes likely to be useful for establishing individualized therapies for patients with rectal cancer.

Short-term results of laparoscopic surgery after preoperative chemoradiation for clinically staged T3 and T4 rectal cancer

The feasibility of laparoscopic surgery for clinically staged T3 and T4 rectal cancer has not been clearly defined specifically in cases following preoperative chemoradiation therapy (CRT). Our aim was to investigate the feasibility of laparoscopic surgery after preoperative CRT for clinically staged T3 and T4 rectal cancer.