Clinical significance of thrombospondin-1 expression in relation to vascular endothelial growth factor and interleukin-10 expression at the deepest invasive tumor site of advanced colorectal carcinoma.

Various angiogenic and angiostatic factors regulate angiogenesis. Tumor angiogenesis is a complicated process for which the detailed mechanisms remain unclear. The aim of this study was to elucidate the clinical significance of TSP-1 expression in relation to expression of VEGF and IL-10 and angiogenesis at the deepest invasive tumor site as a predictor of invasive/metastatic potential and prognosis of advanced colorectal carcinoma (CRC). Patients (n=152) who had undergone surgical resection for advanced CRC were entered in this study. Expression of TSP-1, VEGF, and IL-10 was examined immunohistochemically with specific antibodies. Tumor microvessel density (MVD) was also determined immunohistochemically with anti-CD34 antibody (NU-4A1). Expression of TSP-1, VEGF, and IL-10 at the deepest invasive tumor site was detected in 46 (30.3%), 62 (40.8%), and 39 (25.7%) of 152 lesions, respectively. TSP-1, VEGF, and IL-10 expression at the superficial part was detected in 60 (39.5%), 35 (23.0%), and 46 (30.3%) of 152 lesions, respectively. Although there was no significant difference between the incidence of TSP-1 and IL-10 expression at the deepest invasive site or at the superficial part, there was a significant difference between the incidence of VEGF expression at the deepest invasive site and that at the superficial part. Expression of TSP-1 and IL-10 at the deepest invasive tumor site was inversely correlated with metastatic potential and prognosis in relation to MVD. Furthermore, lesions that were TSP-1-negative and VEGF-positive at the deepest invasive tumor site showed the strongest association with MVD. The 5-year survival rate for patients with TSP-1-negative or IL-10 negative lesions at the deepest invasive tumor site was significantly poorer than that for patients with TSP-1-positive or IL-10-positive lesions, respectively. The 5-year survival rate for patients with VEGF expression at the deepest invasive tumor site was significantly poorer than that for patients without VEGF expression. The 5-year survival rate for patients with TSP-1-negative, VEGF-positive lesions at the deepest invasive site were significantly poorer than that for patients with lesions without these characteristics. Multivariate analysis with logistic regression for 5-year survival in patients with curative surgery showed that lymph node metastasis and VEGF expression were significant prognostic factors. Although lack of TSP-1 or IL-10 expression was associated significantly with poorer prognosis, this may be less important in poorer prognosis than the presence of VEGF expression.

Clinical significance of Fhit expression in development of colorectal carcinoma of various macroscopic types.

It is unclear how expression of the FHIT (fragile histidine triad) gene by the colorectal neoplasm correlates with histogenesis and progression of the disease. We studied the association between expression of Fhit protein and development of colorectal carcinoma (CRC). We also examined relations between Fhit protein expression, macroscopic type, Ki-67 labeling index (LI), and p53 overexpression in carcinoma in situ. We examined 27 colorectal adenomas, 82 carcinomas in situ and 21 invasive CRCs resected endoscopically or surgically. The carcinomas in situ comprised three macroscopic types: polypoid (n=27), superficial (flat elevated, n=27; depressed, n=10) and granulonodular laterally spreading tumor (G-LST, n=23). Fhit, Ki-67, and p53 overexpression were examined immunohistochemically. Levels of Fhit protein were lower in invasive CRC than in adenoma and carcinoma in situ (p<0.01). In carcinoma in situ, reduced Fhit expression was observed in 7 of 22 (31.8%) polypoid types, 13 of 27 (48.1%) superficial flat elevated types, 8 of 10 (80%) superficial depressed types and 7 of 23 (30.4%) G-LST. Frequencies of reduced Fhit expression were significantly higher in the polypoid type and G-LST lesions than in the depressed type (p<0.05). Reduced expression of Fhit protein was related significantly to Ki-67 LI and p53 overexpression in carcinoma in situ (p<0.01). The present findings suggest that reduced expression of Fhit protein is related to development of colorectal neoplasm. Polypoid CRC and G-LST appear to differ from superficial depressed CRC in terms of Fhit expression.

Expression of hypoxia-inducible factor-1alpha is associated with tumor vascularization in human colorectal carcinoma.

HIF-1 is reported to transactivate expression of VEGF, which is an important angiogenic factor. To determine whether HIF-1alpha plays a role in angiogenesis through its regulation of VEGF, we examined expression of HIF-1alpha and its relation to clinicopathologic features, VEGF expression and prognosis of patients with colorectal carcinoma. Expression of HIF-1alpha and VEGF was examined in 4 colorectal carcinoma cell lines (COLO320DM, COLO201, DLD-1, WiDr) and 149 colorectal carcinoma tissues (10 fresh specimens, 139 archival, paraffin-embedded specimens). HIF-1alpha protein levels were increased by hypoxia in 3 of 4 colorectal carcinoma cell lines (COLO201, DLD-1, WiDr), and VEGF mRNA levels were also increased by hypoxia in the same cell lines. In 8 of 10 patients with colorectal cancer, expression of HIF-1alpha and VEGF was increased in tumor tissues compared to corresponding normal mucosa. Of 139 archival specimens of colorectal carcinoma, 81 (58.3%) expressed HIF-1alpha protein at a high level. HIF-1alpha expression was correlated with tumor invasion, tumor stage, lymphatic invasion, venous invasion and liver metastasis. Moreover, HIF-1alpha expression was correlated significantly with VEGF expression and microvessel density. Although there was a tendency for poorer prognosis in patients with high HIF-1alpha-expressing tumors, this correlation was not statistically significant. These findings suggest that HIF-1alpha may play a role in angiogenesis and tumor progression via regulation of VEGF in human colorectal carcinoma.

Clinical significance of angiogenic factor expression at the deepest invasive site of advanced colorectal carcinoma.

Tumor angiogenesis is a complicated process for which the mechanisms remain unclear. The aim of this study was to elucidate the clinical significance of several angiogenic factor expression as a predictor of the invasive/metastatic potential and of the prognosis of advanced colorectal carcinoma (CRC) in relation to their intratumoral histologic heterogeneity. One hundred fifty two patients who had undergone surgical resection for advanced CRC entered this study. PD-ECGF, VEGF, and VEGF-C were examined immunohistochemically with antibodies 1C6-203, A-20, and C-20, respectively. Tumor microvessel density (MVD) was determined immunohistochemically with anti-CD34 antibody. Expression of PD-ECGF, of VEGF, and of VEGF-C at the deepest invasive site were detected in 77 (50.7%), 62 (30.8%), and 71 (46.7%) of the 152 lesions, respectively. PD-ECGF, VEGF, and VEGF-C expression at the deepest invasive site in lesions with liver metastasis (77, 67, and 70%) was significantly higher than that in those without liver metastasis (44, 34, and 41%). In cases with curative surgery, patients with PD-ECGF, VEGF, and VEGF-C expression at the deepest invasive site had a significantly poorer prognosis than those without PD-ECGF, VEGF, and VEGF-C expression at the deepest invasive site. PD-ECGF, VEGF, and VEGF-C expression at the deepest invasive site correlated significantly with MVD. Multivariate analysis with logistic regression for 5-year survival in patients with curative surgery showed that lymph node metastasis and VEGF expression were significant risk factors. Expression of PD-ECGF, VEGF, and VEGF-C was correlated significantly with metastatic potential and prognosis in relation to MVD. Of the several angiogenic factors, VEGF expression at the deepest invasive site of tumor was the most statistically significant indicator of prognosis in advanced CRC.