Abstract A33: A role of SET/I2PP2A in HNSCC angiogenesis and tumor-promoting microenvironment

This study addressed a potential role of SET/I2PP2A protein on angiogenesis and immune response in head and neck squamous cell carcinoma (HNSCC). A HNSCC cell line with stable SET knockdown (HN12shSET/HN12shControl), previously established in our laboratory, was used to perform (1) qPCR array analysis of genes related to angiogenesis (Qiagen), and (2) tube-formation assay using Human Umbilical Vein Endothelial cells (HUVEC) cultured with HN12shSET cells conditioned medium. Moreover, several chemokines and cytokines were analyzed by Multi-Analyte ELISA array (Qiagen), and the specific levels of TGF-B1 and RANTES were validated by a Single-Analyte ELISA array (Qiagen) in cells exposed or not to TNF-alpha; stimulus. The cellular distribution of NF-kB, p-NF-kB and p-STAT3 was assessed by immunofluorescence, cell fractionation and western blotting assays. Our results showed higher levels of genes that induce angiogenesis, in particular VEGFC, in HN12shSET cells; these cells presented, in addition, higher TGF-B1 and lower RANTES/CCL-5 secretion levels compared to controls, as well as dowregulation of CCL-2 expression. Moreover, the stimulation of HUVEC tube-formation by the HN12shSET cells conditioned medium was higher (1.7 fold) compared to control, and p-NF-kB and p-STAT3 were found predominantly in the nucleus of HN12shSET cells; this suggests a negative balance between SET and regulation of these transcription factors. Therefore, SET knockdown in HN12 cells stimulates angiogene...
Source: Molecular Cancer Research - Category: Cancer & Oncology Authors: Tags: Pediatric Cancers and Development: Poster Presentations - Proffered Abstracts Source Type: research