RESUMO
PURPOSE: Lymphatic vessels are mainly regarded as passive conduits for the dissemination of cancer cells. In this study, we investigate whether and how the tumor-associated lymphatic vessels may play an active role in tumor metastasis. EXPERIMENTAL DESIGN: In situ laser capture microdissection of lymphatic vessels followed by cDNA microarray analysis was used to determine the expression profiling of lymphatic endothelial cells (LEC). Gene expression levels and activity of signaling pathways were measured by real-time RT-PCR, ELISA, or immunoblotting. Lymphangiogenesis was assessed by IHC. Lymph node metastasis was measured using fluorescence imaging. The effects of SEMA4C on lymphangiogenesis in vitro were evaluated using migration assay and tube-formation assay of LECs. RESULTS: Tumor-associated LECs are molecularly and functionally different from their normal counterparts. In addition to expressing high levels of membrane-bound SEMA4C, tumor-associated LECs also produced soluble SEMA4C (sSEMA4C). Increased serum sSEMA4C was detected in patients with breast cancer and cervical cancer. Patients with metastasis had much higher levels of serum sSEMA4C. sSEMA4C promoted lymphangiogenesis by activating PlexinB2-ERBB2 signaling in LECs, and promoted the proliferation and migration of tumor cells by activating PlexinB2-MET signaling, thus promoting lymphatic metastasis. Although the SEMA4C signaling pathways differ between LECs and tumor cells, RHOA activation was necessary for the effects of SEMA4C in both types of cells. CONCLUSIONS: Tumor-associated LECs produce sSEMA4C to promote lymphatic metastasis of tumors. Our results suggest that SEMA4C and RHOA might be potential therapeutic targets, and that higher serum sSEMA4C could be a marker for breast cancer and cervical cancer. Clin Cancer Res; 23(1); 214-24. ©2016 AACR.
Assuntos
Células Endoteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias/genética , Neoplasias/metabolismo , Semaforinas/genética , Semaforinas/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Xenoenxertos , Humanos , Imuno-Histoquímica , Linfangiogênese , Metástase Linfática , Vasos Linfáticos/metabolismo , Vasos Linfáticos/patologia , Camundongos Nus , Neoplasias/patologia , Receptor ErbB-2/metabolismo , Transdução de Sinais , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
OBJECTIVE: To explore the expression and clinical significance of signal protein Sema4C in esophageal cancer, gastric cancer and rectal cancer. METHODS: Fifty esophageal cancer, 75 gastric cancer, 50 rectal cancer and 20 corresponding normal mucous membrane specimens, collected during the period of January 2008 to December 2010, were detected with streptavidin-peroxidase immunohistochemistry to detect the expression levels of Sema4C. And the relationships of the Sema4C expression with clinicopathological data was analyzed. RESULTS: The expression levels of Sema4C in three kinds of cancers were significantly higher than the corresponding normal mucous membranes (80.0% (n = 40) vs 20.0% (n = 4), 77.3% (n = 58) vs 25.0% (n = 5), 80.0% (n = 40) vs 15.0% (n = 3), all P = 0.000). Furthermore, the percentage of Sema4C positive cells was significantly higher in carcinoma nests of tumors with lymphatic metastasis than those without (90.3% (n = 28) vs 63.2% (n = 12), 85.0% (n = 51) vs 46.7% (n = 7), 92.0% (n = 23) vs 68.0% (n = 17), P = 0.049, 0.005, 0.034). However, no significant correlations were found between the Sema4C expression with gender, age, location of tumors, types of cancer cells, cell differentiation, tumor size, depth of invasion or tumor stage (all P > 0.05). CONCLUSION: There is a high expression of Sema4C in esophageal cancer, gastric cancer and rectal cancer. And it is strongly correlated with lymphatic metastasis. Thus Sema4C may play critical roles in the invasion and lymphatic metastasis of esophageal cancer, gastric cancer and rectal cancer.
