Clinicopathological characteristics of newly diagnosed colorectal cancers in community gastroenterology practice

Filamin A interacting protein 1-like expression inhibits progression in colorectal cancer

Filamin A interacting protein 1-like (FILIP1L) expression, which is decreased in various cancers, may inhibit carcinogenesis. In this study, we evaluated the effects of FILIP1L on oncogenic behavior and prognosis in colorectal cancer. siRNA-mediated FILIP1L knockdown enhanced tumor cell migration and invasion and inhibited apoptosis and cell cycle arrest in COLO205 cells. pcDNA-myc vector-mediated FILIP1L overexpression suppressed tumor cell migration and invasion and induced apoptosis and cell cycle arrest in HCT116 cells. FILIP1L knockdown enhanced angiogenesis by increasing VEGF-A and HIF-1α levels and decreasing angiostatin level. FILIP1L overexpression suppressed angiogenesis by decreasing VEGF-A and -D l level and increasing angiostatin and endostatin levels. Phosphorylated β-catenin levels decreased and phosphorylated Akt and GSK-3β levels increased following FILIP1L knockdown. FILIP1L overexpression had the opposite effects. FILIP1L expression was associated with reductions in tumor size, cell differentiation, lymphovascular invasion, stage, invasion depth and lymph node metastasis, and with longer overall survival. Mean Ki-67 labeling indexes and microvessel density values were lower in FILIP1L-positive tumors than in FILIP1L-negative tumors. These results indicate that FILIP1L suppresses tumor progression by inhibiting cell proliferation and angiogenesis in colorectal cancer.

Risk factors of missed colorectal lesions after colonoscopy

Several studies have reported a significant rate of missed colorectal polyps during colonoscopy. This study aimed to determine the variables that affect the miss rate of colorectal polyps.We performed a retrospective observational study of patients who, between January 2007 and December 2014, had undergone a second colonoscopy within 6 months of their first. In all patients, the first colonoscopy constituted a screening or surveillance colonoscopy as part of a health check-up, and the patients were referred to the endoscopic clinic if there were meaningful polyps. The miss rate of colorectal polyps was evaluated, as were the variables related to these missed lesions.Among 659 patients (535 men), the miss rate of colorectal polyps was 17.24% (372/2158 polyps), and 38.69% of patients (255/659 patients) had at least 1 missed polyp. The most common site for missed polyps was the ascending colon (29.8%), followed by the sigmoid colon (27.8%). The miss rate of polyps was higher in men [odds ratio (OR) = 1.611, 95% confidence interval (95% CI) = 1.024-2.536], patients with multiple polyps at their first colonoscopy (OR = 1.463, 95% CI = 0.992-2.157), and patients who had a history of polyps (OR = 23.783, 95% CI = 3.079-183.694). Multiple missed polyps were more frequently located in the right colon (OR = 2.605, 95% CI = 1.458-4.657), and the risk of sessile serrated adenoma/polyp was greater in the right colon (OR = 10.418, 95% CI = 2.073-52.353).Endoscopists should pay careful attention in patients who have multiple polyps and in those who have a history of polyps, because such patients are at a high risk of missed polyps in colonoscopy.

Effect of Recepteur d'Origine Nantais expression on chemosensitivity and tumor cell behavior in colorectal cancer

Recepteur d'Origine Nantais (RON) expression is known to induce oncogenic properties including tumor cell growth, survival, motility, angiogenesis and chemoresistance. In the present study, we evaluated whether RON affects chemosensitivity and oncogenic behavior of colorectal cancer cells and investigated its prognostic value in colorectal cancer. To evaluate the impact of RON on chemosensitivity and tumor cell behavior, we treated colorectal cancer cells with small interfering RNAs specific to RON. This was followed by flow cytometric analyses and migration, Matrigel invasion and endothelial tube formation assays. The expression of RON was investigated by immunohistochemistry in colorectal cancer tissues. TUNEL assay and immunohistochemical staining for CD34 and D2-40 were deployed to determine apoptosis, angiogenesis and lymphangiogenesis. RON knockdown enhanced 5-fluorouracil (FU)-induced apoptosis by upregulating the activities of caspases and expression of proapoptotic genes. Moreover, it enhanced 5-FU-induced cell cycle arrest by decreasing the expression of cyclins and cyclin‑dependent kinases and inducing that of p21. Furthermore, RON knockdown augmented the 5-FU-induced inhibition of invasion and migration of colorectal cancer cells. The β-catenin signaling cascade was blocked by RON knockdown upon 5-FU treatment. RON knockdown also decreased endothelial tube formation and expression of VEGF-A and HIF-1α and increased angiostatin expression. Furthermore, it inhibited lymphatic endothelial cell tube formation and the expression of VEGF-C and COX-2. RON expression was observed to be associated with age, tumor size, lymphovascular and perineural invasion, tumor stage, lymph node and distant metastasis, and poor survival rate. The mean microvessel density value of RON-positive tumors was significantly higher than that of RON-negative ones. These results indicate that RON is associated with tumor progression by inhibiting chemosensitivity and enhancing angiogenesis in colorectal cancer.

Risk of developing advanced colorectal neoplasia after removing high-risk adenoma detected at index colonoscopy in young patients: A KASID study

BACKGROUND AND AIM

Advanced adenoma (> 10 mm in diameter, villous structure, or high-grade dysplasia) in young patients may have different characteristics and prognosis compared with those in older patients. We aimed to compare the incidence of colorectal neoplasms in young patients with older patients after removing high-risk adenoma (advance adenoma or ≥ 3 adenomas).

METHODS

A retrospective, multicenter study was conducted at 13 university hospitals in Korea. The 1479 patients who removed high-risk adenoma at index colonoscopy and followed by surveillance colonoscopy ≥ 2.5 years after were included. The cumulative incidence of overall and advanced colorectal neoplasms was compared according to the age groups (group 1: < 50 years, group 2: 50-70 years, and group 3: ≥ 70 years).

RESULTS

The prevalence of advance adenoma detected at index colonoscopy was significantly higher in group 1 than in groups 2 and 3 (85.4%, 78.1%, and 77.2%, respectively; P = 0.035). The 5 years cumulative incidence of overall and advanced colorectal neoplasms were 61.9%, 67.9%, and 74.7% (P < 0.001), and 11.7%, 17.9%, and 27.1% (P = 0.001) in groups 1, 2, and 3, respectively. In multivariate analysis, age > 70 years was a significant risk factor for developing overall (hazard ratio [HR] 1.41, 95% confidence interval [CI] 1.12-1.82, P = 0.004) and advanced colorectal neoplasms (HR = 2.56, 95% CI 1.43-4.59, P = 0.002).

CONCLUSION

The cumulative incidence of overall and advanced colorectal neoplasms was significantly higher in older patients than in young patient groups. Age was a significant risk factor for developing colorectal neoplasms after removing high-risk adenoma.

Impact of KITENIN on tumor angiogenesis and lymphangiogenesis in colorectal cancer

Angiogenesis and lymphangiogenesis are involved in the dissemination of tumor cells from solid tumors to regional lymph nodes and various distant sites. KAI1 COOH-terminal interacting tetraspanin (KITENIN) contributes to tumor progression and poor clinical outcomes in various cancers including colorectal cancer. The aim of the present study was to evaluate whether KITENIN affects tumor angiogenesis and lymphangiogenesis in colorectal cancer. A KITENIN small interfering RNA vector was used to silence KITENIN expression in colorectal cancer cell lines including DLD1 and SW480 cells. To evaluate the ability of KITENIN to induce angiogenesis and lymphangiogenesis in human umbilical vein endothelial cells (HUVECs) and lymphatic endothelial cells (HLECs), we performed Matrigel invasion and tube formation assays. Immunohistochemistry was used to determine the expression of KITENIN in colorectal cancer tissues. Angiogenesis and lymphangiogenesis were evaluated by immunostaining with CD34 and D2-40 antibodies. KITENIN silencing inhibited both HUVEC invasion and tube formation in the DLD1 and SW480 cells. KITENIN silencing led to decreased expression of the angiogenic inducers vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor-1α and increased expression of the angiogenic inhibitor angiostatin. KITENIN silencing did not inhibit either HLEC invasion or tube formation in all tested cells, but it resulted in decreased expression of the lymphangiogenic inducer VEGF-C. KITENIN expression was significantly associated with tumor stage, depth of invasion, lymph node and distant metastases and poor survival. The mean microvessel density was significantly higher in the KITENIN-positive tumors than that in the KITENIN-negative tumors. However, the mean lymphatic vessel density of KITENIN-positive tumors was not significantly higher than that of the KITENIN-negative tumors. These results suggest that KITENIN promotes tumor progression by enhancing angiogenesis in colorectal cancer.

Impact of prospero homeobox-1 on tumor cell behavior and prognosis in colorectal cancer

Prospero homeobox 1 (PROX1) is up-regulated in colorectal cancer and plays an oncogenic role. In the present study, we sought to investigate the impact of PROX1 on oncogenic processes and to assess the prognostic value of PROX1 expression in colorectal cancer. A small interfering RNA or pcDNA6-myc vector was used to control PROX1 gene expression in colorectal cancer DLD1 and SW480 cell lines. The expression of PROX1 in colorectal cancer tissues was investigated by immunohistochemistry. Angiogenesis, lymphangiogenesis, and tumor cell proliferation were assessed by analyzing the expression of respective markers of these phenomena, CD34, D2-40, and Ki-67 after immunohistochemical staining. PROX1 knockdown decreased both umbilical vein endothelial cell invasion and tube formation, down-regulated the expression of VEGF-A and HIF-1α, and up-regulated the expression of angiostatin. Lymphatic endothelial cell invasion and tube formation as well as the expression of VEGF-C were also suppressed by PROX1 knockdown. PROX1 knockdown suppressed tumor cell proliferation, migration, invasion, and epithelial-mesenchymal transition. In contrast, PROX1 overexpression enhanced tumor cell angiogenesis, lymphangiogenesis, proliferation, migration, invasion, and epithelial-mesenchymal transition. Levels of phosphorylated Akt, GSK3β, and MAPK were decreased by PROX1 knockdown and increased by PROX1 overexpression. PROX1 expression positively correlated with tumor size, extent of differentiation, lymphovascular invasion, depth of invasion, lymph node metastasis, stage, and poor survival. The mean microvessel density and Ki-67 labeling index values of PROX1-positive tumors were significantly higher than those of PROX1-negative tumors. However, there was no significant correlation between PROX1 expression and lymphatic vessel density. These results indicate that PROX1 influences tumor progression in colorectal cancer by regulating angiogenesis and tumor cell proliferation.