Identification of a Novel Angiogenesis and Tumor Suppressor Gene Rab25 in Esophageal Squamous Cell Carcinoma

Twelve clinical samples from human esophageal squamous cell carcinoma (ESCC) (seven tumors and five non-tumors) were sequenced using Illumina high-throughput sequencing and the RNA-Seq profiling was investigated with 1730 genes significantly differentially expressed. The gene Rab25 was found to be down-regulated in tumors (p-value < 1E-20) and identified as a novel candidate tumor suppressor gene. The down-regulation of Rab25 was examined in a large cohort of ESCC and non-tumor cases by qPCR and immunohistochemistry analyses. Aberrant methylation in the promoter region of Rab25 was studied by demethylation treatment with 5-aza-dC and bisulfite genomic sequencing (BGS). In order to assess the effect of Rab25 on tumor growth and angiogenesis, in vitro and in vivo functional studies in ESCC cell lines using lentiviral-based overexpression or knockdown models were also performed. Overall design: 7 tumor and 5 normal samples