VEGF-C contributes to head and neck squamous cell carcinoma growth and motility.
ABSTRACT Previous work from our laboratory has demonstrated overexpression of chemokines in head and neck cancer and the utility of targeting these proteins for tumor therapy in a preclinical model. However, the mechanisms involved are unexplored. Through gene expression analysis, we found that expression of vascular endothelial growth factor (VEGF-C) was elevated in HN12 cells expressing high levels of CXCL5. In the present study, we have investigated the contribution of VEGF-C to tumor cell growth and motility. RNAi-mediated knockdown of VEGF-C expression in HN12 cells, which express high levels of CXCL5, resulted in a decrease in proliferation. Conversely, forced expression of VEGF-C in HN4 tumor cells with low endogenous CXCL5 levels increased cell growth. Suppression of VEGF-C inhibited migration of HN12 cells. Similarly, HN4 cells showed reduced migration towards conditioned media collected from HN12 cells with VEGF-C knockdown compared to controls, while HN4/VEGF-C conditioned media stimulated cell migration. Moreover, tumor growth in vivo was markedly reduced when VEGF-C expression was blocked by shRNA. Finally, determination of VEGF-C expression in squamous carcinoma cell lines revealed universal overexpression compared to normal keratinocytes. These findings support a role for VEGF-C in head and neck squamous cell carcinogenesis.
- SourceAvailable from: Madhusudan S Astekar
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ABSTRACT: Head and neck squamous cell carcinoma (HNSCC) is characterised by an elevated capacity for tumor invasion and lymph node metastasis and the cause remains to be determined. Recent studies suggest that microRNAs can regulate the evolution of malignant behaviours by regulating multiple target genes. In this study, we have first confirmed that miR-363 is down-regulated in HNSCC tissues with lymph node metastasis and cell lines with highly invasive capacity. We used bioinformatics, cellular and molecular methods to predict and prove that miR-363 directly targeted to podoplanin (PDPN) and caused up-regulation of PDPN in HNSCC. MSP assay showed that DNA promoter methylation was involved in silencing the miR-363 in HNSCC. Furthermore, we provided evidence to demonstrate that PDPN dysregulation caused by down-regulation of miR-363 contributes to HNSCC invasion and metastasis. These data reveal a key role of miR-363-PDPN in HNSCC metastasis and support biological and clinical links between miR-363-PDPN and HNSCC.The international journal of biochemistry & cell biology 12/2012; · 4.89 Impact Factor
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ABSTRACT: BACKGROUND: alphaB-crystallin is able to modulate vascular endothelial growth factor (VEGF) secretion. In many solid tumors VEGF is associated with angiogenesis, metastasis formation and poor prognosis. We set out to assess whether alphaB-crystallin expression is correlated with worse prognosis and whether this is related to VEGF secretion and cell motility in head and neck squamous cell carcinoma (HNSCC). METHODS: alphaB-crystallin expression was determined immunohistochemically in tumor biopsies of 38 HNSCC patients. Locoregional control (LRC) and metastasis-free survival (MFS) of the patients were analyzed in relation to alphaB-crystallin expression. Additionally, the effects of alphaB-crystallin knockdown on VEGF secretion and cell motility were studied in vitro. RESULTS: Patients with higher staining fractions of alphaB-crystallin exhibited a significantly shorter MFS (Log-Rank test, p < 0.005). Under normoxic conditions alphaB-crystallin knockdown with two different siRNAs in a HNSCC cell line reduced VEGF secretion 1.9-fold and 2.1-fold, respectively. Under hypoxic conditions, a similar reduction of VEGF secretion was observed, 1.9-fold and 2.2-fold, respectively. The effect on cell motility was assessed by a gap closure assay, which showed that alphaB-crystallin knockdown decreased the rate by which HNSCC cells were able to close a gap by 1.5- to 2.0-fold. CONCLUSIONS: Our data suggest that alphaB-crystallin expression is associated with distant metastases formation in HNSCC patients. This association might relate to the chaperone function of alphaB-crystallin in mediating folding and secretion of VEGF and stimulating cell migration.BMC Cancer 03/2013; 13(1):128. · 3.32 Impact Factor