Expression of 5-Lipoxygenase in human colorectal cancer

AIM: To evaluate the 5-lipoxygenases (Loxs) expression level in human colorectal cancer specimens in order to determine its clinicopathologic significance in human tumorigenesis. METHODS: The relative quantity of 5-Lox mRNA in paired 91 colorectal tumor and adjacent normal mucosa samples was determined by real time quantitative PCR. Additionally, the expression of 5-Lox and cyclooxygenase (Cox)-2 proteins was also examined using immunohistochemical staining methods. RESULTS: There was a marked increase in 5-Lox mRNA levels in the tumor compared with paired normal mucosa samples (P < 0.0001). Sixty six (72.5%) tumors showed high 5-Lox mRNA levels. The positivity rate of 5-Lox and Cox-2 protein expression was 68.7% and 79.1% respectively. There was a significant association between tumoral 5-Lox mRNA level and tumor size (Rho = 0.392, P = 0.0002), depth or vessel invasion. CONCLUSION: These results suggest that 5-Lox is up-regulated in colorectal cancer and that inhibition of its expression might be valuable in the prevention and treatment of colorectal cancer.

Over-the-scope-clipping system for anastomotic leak after colorectal surgery:Report of two cases

An anastomotic leak is one of the major complications following colorectal surgery.Standard treatments for anastomotic leak are total parenteral nutrition or temporary ileostomy.The over-the-scope-clipping(OTSC)system was originally developed to treat intestinal perforation or to close the tissue after natural orifice transluminal endoscopic surgery.Two cases of successful management of an anastomotic leak after colorectal surgery using the OTSC system are reported.One patient avoided a temporary ileostomy.In the other,hospitalization was shortened by the use of the OTSC system.The OTSC system can be a potential option in the management of anastomotic leaks after colorectal surgery.

Clinical Significance of Platelet-Derived Growth Factor-C Expression in Colorectal Cancer

Platelet-derived growth factors (PDGFs) are known to be associated with tumor growth and angiogenesis through their activation of the receptor tyrosine kinases, PDGF receptors alpha and beta. Several studies revealed the participation of the PDGF family in colorectal cancer (CRC). However, the role of platelet derived growth factor-C (PDGFC) in CRC is less well studied. This study aimed to determine the correlation between PDGFC expression and the prognosis of patients with CRCs. Tumor samples were obtained from patients with CRC who underwent surgical resection between 2002 and 2006. The mRNA expression of PDGFC was investigated by quantitative reverse transcription-polymerase chain reaction in 85 patients with stage I-IV CRC. PDGFC protein expression was analyzed by immunohistochemistry, and the relationship between PDGFC protein expression and clinicopathologic features was investigated in 245 patients with stage I-III CRC. PDGFC mRNA expression in cancer tissues was significantly higher in patients with distant metastases than in those without metastases (P = 0.016). PDGFC protein overexpression was associated with significantly worse overall and relapse-free survival (P P < 0.0001, respectively). Moreover, PDGFC protein overexpression was an independent risk factor for CRC recurrence (relative risk = 3.395, 95% confidence interval = 1.895 - 6.081, P < 0.001). In the present study, PDGFC overexpression appeared to be predictive of recurrence and poor prognosis in patients with CRC.