COX-2 and angiogenesis in gastric cancer

Anti-tumor enhancement of Fei-Liu-Ping ointment in combination with celecoxib via cyclooxygenase-2-mediated lung metastatic inflammatory microenvironment in Lewis lung carcinoma xenograft mouse model

Background

Fei-Liu-Ping (FLP) ointment is an oral prescription medication that has been widely applied to treat lung cancer patients in China. Regulation of the metastatic microenvironment is an important therapeutic approach for prevention and treatment of tumor recurrence and metastasis. The advantage of Traditional Chinese Medicine management of lung cancer lies in the prevention of recurrence and metastasis. Our previous study has demonstrated that FLP ointment could regulate lung inflammatory microenvironment in vitro. However, the effects of FLP on the tumor microenvironment in vivo are still poorly understood. The objective of this study is to investigate the effect of FLP alone or in combination with celecoxib in the prevention of lung cancer progression by Cyclooxygenase (Cox)-2 mediated tumor inflammatory microenvironment in vivo.

Methods

120 Lewis lung carcinoma xenograft mice were divided equally into four groups: vehicle, FLP, celecoxib, and FLP plus celecoxib. The dynamic growth of the xenografted tumors was observed using an in vivo fluorescence imaging system. Mice were sacrificed on day 14, day 21, and day 28, and tumor specimens and lung tissues were harvested to detect the metastasis-associated protein expression.

Results

Tumor inhibition rate was 15.4, 44.2, 47.4 % at day 14, 37.3, 34.7, 61.5 % at day 21, and 15.5, 10.3, 32.5 % at day 28 after treatment of FLP, celecoxib, and FLP plus celecoxib, respectively. Upon treatment of FLP and celecoxib together, lung metastasis rate was 30 % (8 metastatic nodules) lower than other groups. FLP inhibited Cox-2 expression in a time-dependent manner. Moreover, FLP inhibited N-cadherin, matrix metalloproteinases (MMP)-9, and Vimentin expression. Treatment of FLP in combination with celecoxib was more effective than FLP or celecoxib alone in inhibiting vascular endothelial growth factor, platelet-derived growth factor receptors β, microsomal Prostaglandin E synthase-1, MMP-2, MMP-9, N-cadherin, and Vimentin expression, but increased E-cadherin expression.

Conclusions

FLP inhibited tumor growth and metastasis in a Lewis lung xenograft mice model through the Cox-2 pathway. FLP in combination with celecoxib enhanced the antitumor growth and anti-metastasis effects. Traditional Chinese herbs combined with anti-inflammatory drugs might offer a promising strategy to prevent tumor metastasis.

Expression of cyclooxygenase-2 and vascular endothelial growth factor-C correlates with lymphangiogenesis and lymphatic invasion in human gastric cancer

BACKGROUND

Recent observations have suggested that overexpression of cyclooxygenase-2 (COX-2) promotes tumor lymphangiogenesis through an upregulation of vascular endothelial growth factor-C (VEGF-C) expression. It is unclear whether this mechanism also acts in gastric cancer. The aim of this study was to determine the relationship between COX-2 and VEGF-C expression in human gastric cancer, as well as to correlate with lymph node involvement, prognosis, and other clinicopathologic parameters.

METHODS

Sixty-eight primary gastric cancers were immunohistochemically examined for COX-2, VEGF-C, vascular endothelial growth factor receptor-3 (VEGFR-3, also known as Flt-4), and CD34 expressions. Assessment of Flt-4-positive vessel density (FVD) and microvessel density (MVD) was performed. Then we analyzed their relationships and correlations with clinicopathologic findings and patients' survival time.

RESULTS

The positivity rate of COX-2 and VEGF-C in the primary tumor was 67.7 and 54.4 percent, respectively. A significant correlation was found between the expression of VEGF-C and COX-2, and both were also correlated to MVD, FVD, lymphatic invasion, and TNM stage (p<0.05). COX-2 immunoreactivity was also associated with lymph node metastasis and serosa invasion. Increased MVD was significantly associated with lymph node metastasis and TNM stage. Both COX-2 and VEGF-C expression significantly correlated with poorer prognosis.

CONCLUSIONS

Our data suggest that the expression of COX-2 correlates with VEGF-C expression and both of them correlate with the presence of lymphatic invasion and prognosis in gastric cancer. COX-2-mediated VEGF-C overexpression might promote lymphatic invasion via lymphangiogenesis pathway in patients with gastric cancer.

Microvessel density is a prognostic marker of human gastric cancer

AIM: To investigate whether microvessel density (MVD) is related with prognosis in gastric cancer patients, and the expression of cyclooxygenase-2 (COX-2) and vessel endothelial growth factor (VEGF) so as to determine the possible role of COX-2 and VEGF in gastric cancer angiogenesis.

METHODS: Forty-seven formalin-fixed paraffin-embedded tissue samples of gastric cancer were evaluated for COX-2, VEGF by immunohistochemical staining. To assess tumor angiogenesis, MVD was determined by immunohistochemical staining of endothelial protein factor VIII-related antigen. The relationship among COX-2 and VEGF expression, MVD, and clinicopathologic parameters was analyzed.

RESULTS: Among the 67 samples, high MVD was significantly associated with lymph node metastasis and poor survival. Multivariate survival analysis showed that MVD value and lymph node metastasis were independent prognostic factors. The expression rate of COX-2 and VEGF was significantly higher than that of the adjacent tissues. COX-2 and VEGF expression in gastric cancer was significantly correlated with tumor differentiation and depth of invasion, but not with survival. The mean MVD value of COX-2 or VEGF positive tumors was higher than that of COX-2 or VEGF negative tumors. A significant correlation was found between the expressions of COX-2 and VEGF.

CONCLUSION: MVD may be one of the important prognostic factors for gastric cancer patients. COX-2 and VEGF may play an important role in tumor progression by stimulating angiogenesis. VEGF might play a main role in the COX-2 angiogenic pathway. The inhibition of angiogenesis or COX-2, VEGF activity may have an important therapeutic benefit in the control of gastric cancer.

Expression of cyclo-oxygenase 1 and 2, prostaglandin E synthase and transforming growth factor beta1, and their relationship with vascular endothelial growth factors A and C, in primary adenocarcinoma of the small intestine

BACKGROUND

Primary adenocarcinomas of the small intestine are rare. The prostaglandin biosynthetic pathway plays a major role in carcinogenesis and is linked with angiogenesis in various tumours. Promotion of tumour growth by transforming growth factor (TGF) beta may be mediated through the prostaglandin pathway.

METHODS

Expression of cyclo-oxygenase (COX) 1 and 2, prostaglandin E synthase (PGES), TGF-beta1 and vascular endothelial growth factor (VEGF) A and C genes was analysed in 54 primary adenocarcinomas of the small intestine and corresponding normal intestinal mucosa. All patients had undergone surgical resection without previous antineoplastic therapy. Target gene expression was analysed at the mRNA level by reverse transcriptase-polymerase chain reaction and correlated with clinicopathological parameters as well as survival. COX-2 protein expression was examined by immunohistochemistry.

RESULTS

Expression of COX-2 protein was detected immunohistochemically in 98 per cent of the carcinomas. COX-1, COX-2, VEGF-A, VEGF-C, PGES and TGF-beta1 mRNA expression varied markedly in different tumours, but all were overexpressed compared with levels in normal intestinal mucosa. There were significant associations between levels of COX-1, COX-2, TGF-beta1 and PGES mRNAs and those of VEGF-A and VEGF-C.

CONCLUSION

Correlations between levels of mRNA for COX-1, COX-2, TGF-beta1 and PGES and those for proangiogenic factors VEGF-A and VEGF-C suggest a role for these factors in the propagation of primary adenocarcinomas of the small intestine.

Cyclooxygenase-2 expression is associated with VEGF-C and lymph node metastases in gastric cancer patients

Previous studies have suggested that cyclooxygenase-2 (COX-2) over-expression is associated with angiogenesis in gastric cancer. However, the relationship between COX-2 and lymphangiogenesis is still unclear. The aim of this study was to determine the relationship between COX-2 expression and lymphangiogenic factor, vascular endothelial growth factor-C (VEGF-C), in human gastric cancer, as well as to correlate with clinicopathological parameters. Sixty-three gastric cancer patients underwent radical gastrectomy (D2 or D3) were enrolled in this study. The expression of COX-2 and VEGF-C were detected by immunohistochemistry, and the small lymphatic vessels were immunohistochemically stained by LYVE-1 antibody. The association between COX-2 and VEGF-C expressions and clinicopathological parameters (such as gender, tumor location, lymph node status and Lauren classification) were determined. VEGF-C over-expression was observed in 33 of 63 patients (52%), while COX-2 over-expression occurred in 42 of 63 tumor samples (67%). Presence of microlymphatic vessels with LYVE-1 staining was found in 35 cases. COX-2 over-expression was highly correlated with VEGF-C over-expression (P = 0.032), microlymphatic vessels (P = 0.002) as well as presence of metastatic lymph nodes (P = 0.007). However, no significant correlation was found between COX-2 expression and other clinicopathological parameters. Our data suggest that COX-2 expression is associated with lymphangiogenesis and lymph node metastasis in human gastric carcinoma. This raises the possibility that COX-2-mediated VEGF-C over-expression might promote lymph node metastasis via lymphangiogenesis pathway in patients with gastric cancer.