NOTCH1 activates the Wnt/ß-catenin signaling pathway in colon cancer.

PURPOSE AND METHODS: The translocation of ß-catenin/CTNNB1 to the nucleus activates Wnt signaling and cell proliferation; however, the precise mechanism underlying this phenomenon remains unknown. Previous reports have provided evidence that NOTCH1 is involved in the Wnt signaling pathway. Therefore, we sought to determine the mechanism by which NOTCH1 influences the Wnt/ß-catenin pathway. We constructed a vector expressing the NOTCH1 intracellular domain (NICD1) and transfected the vector into HCT116 which has low expression of NICD1. Furthermore, inhibition of NOTCH signal pathway in SW480 which has abundant NICD1 expression, was performed by transfection of siNICD1 or DAPT, gamma secretase inhibitor, treatment. In addition, we evaluated NICD1 and ß-catenin localization in colon cancer cell lines and in 189 colon cancer tissue samples and analyzed the correlation between the nuclear localization of NICD1 and the clinicopathological features of colon cancer patients. RESULTS: Immunohistochemical assays demonstrated that NICD1 and ß-catenin exhibited a similar localization pattern in colon cancer tissues. In addition, we found that NICD1 induced the translocation of ß-catenin to the nucleus and that NICD1 and ß-catenin co-localized in the nucleus. Overexpression of NICD1 increased luciferase activity of Wnt signal pathway. On the other hand, reduction of NICD1 reduced luciferase activity of Wnt signaling pathway. In the 189 analyzed colon cancer cases, multivariate COX regression analysis demonstrated the independent prognostic impact of nuclear localization of NICD1(p=0.0376). CONCLUSION: NOTCH1 plays a key role in the Wnt pathway and activation of NOTCH1 is associated with the translocation of ß-catenin to the nucleus.

Use of barbed suture for peritoneal closure in transabdominal preperitoneal hernia repair.

AIM: To investigate the use of the V-Loc wound closure device for transabdominal preperitoneal hernia repair. METHODS: We performed conventional transabdominal preperitoneal hernia repair in 19 patients, including one single incisional case using V-Loc. Except for the use of V-Loc for peritoneal closure, the procedures were the same as those used in conventional techniques. RESULTS: Although the operators included 2 residents who have no experience in laparoscopic herniorrhaphy and intracorporeal suture, the operations were completed. We believe that V-Loc is especially suitable for inexperienced surgeons and the use of V-Loc reduces the operative time by a small amount but reduces operator stress significantly. CONCLUSION: We conclude that V-Loc is the ideal peritoneal closure device for transabdominal preperitoneal hernia repair.

Thymidylate synthetase and dihydropyrimidine dehydrogenase mRNA levels in esophageal cancer.

This study investigated the mRNA levels of thymidylate synthetase (TYMS) and dihydropyrimidine dehydrogenase (DPYD) in esophageal squamous cell carcinoma (ESCC). TYMS and DPYD gene expression was quantified using real-time RT-PCR in 56 patients with ESCC, co-amplified with glyceraldehyde-3-phosphate dehydrogenase as an internal standard. The results were analyzed with reference to the clinicopathological characteristics and the prognosis of the ESCC patients. The TYMS and DPYD expression levels in patients positive with lymphatic invasion were significantly higher compared to those in patients who exhibited negative lymphatic invasion (TYMS P=0.0127, DPYD P=0.0127). Patients were classified into the groups high TYMS/DPYD, high TYMS but low DPYD, low TYMS but high DPYD and low TYMS/DPYD. The highest survival rate was found in the group with low TYMS/DPYD and the lowest survival rate in the group with high TYMS/DPYD (P=0.017). It was concluded that, on the basis of the multivariate analysis, TYMS mRNA expression is a candidate that serves as an independent prognostic factor for ESCC patients.

Expression of CD44v6 is an independent prognostic factor for poor survival in patients with esophageal squamous cell carcinoma.

CD44v6 has been causally associated with the development of metastases and with poor prognosis in various human malignancies. To elucidate the clinicopathological significance of CD44v6 expression in esophageal squamous cell carcinoma (ESCC), the present study aimed to investigate the expression of CD44v6 using immunohistological techniques. Using specific antibodies against CD44v6 and CD44s, expression of the proteins was analyzed immunohistochemically in 63 primary esophageal ESCCs, which were previously resected at the Nagoya City University Hospital without pre-operative induction therapy. Using light microscopy, the positive expression of CD44v6 was divided into a low- or high-expression group. The expression of CD44v6 in ESCC was analyzed with respect to various clinicopathological characteristics. The frequency of CD44v6 expression was 90.5% (57/63). The CD44v6 high-expression group comprised 55.6% of the patients (n=35) and the low expression group included 44.4% of the patients (n=28). In this study, no significant difference was observed between any clinicopathological factor and the immunohistochemical expression of CD44v6. In patients with high levels of CD44v6 expression, survival was markedly worse (p=0.0327). Favorable outcomes were observed for the clinicopathological characteristics of 6 patients whose tissue immunohistochemical expression of CD44v6 was not detected. Moreover, multivariate analysis confirmed that expression of CD44v6 was an independent prognostic indicator (risk ratio =2.793; p=0.0301). Overexpression of CD44v6 is a useful prognostic indicator of ESCC. Therefore, CD44v6 should be investigated as a potential target for therapy.

Vascular endothelial growth factor C (VEGF-C) in esophageal cancer correlates with lymph node metastasis and poor patient prognosis.

BACKGROUND: The diagnosis of lymph node metastasis in esophageal cancer by the presence and number of metastatic lymph nodes is an extremely important prognostic factor. In addition, the indication of non-surgical therapy is gaining more attention. Vascular endothelial growth factor C (VEGF-C) is potentially lymphangiogenic and selectively induces hyperplasia of the lymphatic vasculature. In this study, we investigated the expression of VEGF-C and whether it correlated with various clinico-pathologic findings. METHODS: KYSE series of esophageal cancer cell lines and 106 patients with primary esophageal squamous cell carcinomas who had undergone radical esophagectomy were analyzed. VEGF-C mRNA expression was determined by quantitative RT-PCR. RESULTS: High expression of VEGF-C was detected in most of the KYSE cell lines, especially KYSE410, yet, in an esophageal normal epithelium cell line, Het-1A, VEGF-C was not detected. In the clinical specimen, the expression of VEGF-C in the cancerous tissue was higher than in the corresponding noncancerous esophageal mucosa (p = 0.026). The expression of VEGF-C was found to be higher in Stage2B-4A tumors than in Stage0-2A tumors (p = 0.049). When the patients were divided into two groups according to their expression levels of VEGF-C (a group of 53 cases with high expression and a group of 53 cases with low expression), the patients with high VEGF-C expression had significantly shorter survival after surgery than the patients with low expression (p = 0.0065). Although univariate analysis showed that high expression of VEGF-C was a statistically significant prognostic factor, this was not shown in multivariate analysis. In the subgroup of patients with Tis and T1 tumors, the expression of VEGF-C was higher in N1 tumors than in N0 tumors (p = 0.029). The survival rate of patients from the high expression group (n = 10) was lower than that in the low expression group (n = 11), and all the patients in the low VEGF-C expression group survived. CONCLUSIONS: The expression of VEGF-C correlates with lymph node metastasis and poor prognosis. In patients with Tis and T1 esophageal tumors, the expression of VEGF-C may be a good diagnostic factor for determining metastasis of the lymph node.

MicroRNA-34b has an oncogenic role in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a common malignancy and one of the more difficult diseases to diagnose in Japan due to its poor prognosis. MicroRNAs are small non-coding RNAs of 21-23 nucleotides that regulate gene expression. MicroRNA-34b (miR-34b) has been reported to be overexpressed in various types of cancer. However, its role in ESCC has yet to be extensively studied. The present study investigated the expression of miR-34b in 88 ESCC patients. The miR-34b expression in ESCC was significantly higher than that in the corresponding normal esophageal mucosa. It was more highly expressed in tumors with more advanced stages. However, its expression did not correlate with the p53 status. Transfection of anti-miR-34b to the ESCC cells suppressed cell growth in vitro. These results suggest an oncogenic role of miR in ESCC.

Decreased expression of FBXW7 is correlated with poor prognosis in patients with esophageal squamous cell carcinoma.

FBXW7 is a tumor suppressor gene that induces the degradation of positive cell-cycle regulators such as c-Myc, cyclin E, c-Jun and Notch. The loss of FBXW7 promotes cell-cycle progression and cell proliferation. In the present study, we investigated the relationship between FBXW7 expression and the clinicopathological characteristics of patients with esophageal squamous cell carcinoma (ESCC). The expression of FBXW7 was quantified by real-time reverse transcription polymerase chain reaction in 43 primary ESCCs and their paired normal esophageal mucosa in patients who had not received preoperative therapy. FBXW7 expression levels were significantly correlated with the progression of the cancer and with local invasiveness. In muscle-invasive tumor cases (T2-4), lymphatic invasive tumor cases and stage II-IV cases, FBXW7 expression levels were significantly decreased (P=0.0315, P=0.0336 and P=0.0289, respectively). Decreased expression of FBXW7 was correlated with poor prognosis (P=0.0255). In conclusion, this study examined the relationship between FBXW7 expression and tumor progression in ESCC. We suggest that FBXW7 is a molecular prognostic marker and can be used to elucidate the mechanism of carcinogenesis.

MicroRNA-21 induces cell proliferation and invasion in esophageal squamous cell carcinoma.

It has been suggested that microRNA-21 (miR-21) functions as an oncogene, as it is overexpressed in many types of tumors compared to adjacent normal tissues. However, the role of miR-21 has yet to be studied in esophageal squamous cell carcinoma (ESCC). miR-21 expression was quantified by real-time reverse transcription polymerase chain reaction in 38 ESCC specimens and their paired non-cancerous mucosa, and in 15 esophageal cancer cell lines (TE1-15). miR-21 expression levels in ESCC tissue were significantly higher than in the corresponding non-cancerous mucosa (6.873±12.664 vs. 1.000, p<0.0001). In patients with more advanced (T3 or T4) tumors, miR-21 expression levels were significantly higher than in those with less advanced (T1 or T2) tumors (P=0.0333). miR-21 expression levels in patients with more invasive infiltrative growth pattern (inf) ß tumors were significantly higher than in patients with less invasive infα tumors (P=0.0166). Among the cell lines studied, TE9 had the lowest and TE1 the highest expression of miR-21. Using the miRNA precursor or antisense miRNA inhibitor, we studied how the level of miR-21 influences the proliferation of ESCC cells. Cell proliferation of the anti-miR-21-transfected cell line was significantly lower, while that of the pre-miR-21-transfected cell line was significantly higher than in the control. In ESCC, miR-21 expression may be involved in tumor growth and invasion.