RESUMO
Cell division cycle associated 7 (CDCA7) is a copy number amplification gene that contributes to the metastasis and invasion of tumors, including esophageal squamous cell carcinoma (ESCC). This present study aimed at clarifying whether high expression of CDCA7 promotes the metastasis and invasion of ESCC cell lines and exploring the underlying mechanisms implicated in epithelial-mesenchymal transition (EMT) of ESCC. The role of CDCA7 in the regulation of ESCC metastasis and invasion was evaluated using ESCC cell lines. Expression of EMT-related markers including E-cadherin, N-cadherin, Vimentin, Snail, and Slug, transforming growth factor ß (TGF-ß) signaling pathway including Smad2/3, p-Smad2/3, Smad4, and Smad7 were detected in CDCA7 knockdown and overexpressed cell lines. Dual-luciferase reporter assay and rescue assay were used to explore the underlying mechanisms that CDCA7 contributed to the metastasis and invasion of ESCC. High CDCA7 expression significantly promoted the metastasis and invasion of ESCC cell lines both in vivo and in vitro. Additionally, the expression of CDCA7 positively correlated with the expression of N-cadherin, Vimentin, Snail, Slug, TGF-ß signaling pathway and negatively correlated with the expression of E-cadherin. Furthermore, CDCA7 transcriptionally regulated the expression of Smad4 and Smad7. Knockdown of CDCA7 inhibited the TGF-ß signaling pathway and therefore inhibited EMT. Our data indicated that CDCA7 was heavily involved in EMT by regulating the expression of Smad4 and Smad7 in TGF-ß signaling pathway. CDCA7 might be a new therapeutic target in the suppression of metastasis and invasion of ESCC.
Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Carcinoma de Células Escamosas do Esôfago/genética , Fator de Crescimento Transformador beta/metabolismo , Vimentina/genética , Vimentina/metabolismo , Neoplasias Esofágicas/patologia , Transição Epitelial-Mesenquimal/genética , Linhagem Celular Tumoral , Caderinas/genética , Caderinas/metabolismo , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Proteína Smad4/genética , Proteína Smad4/metabolismo , Proteínas Nucleares/genética , Proteína Smad7/genética , Proteína Smad7/metabolismoRESUMO
BACKGROUND: CDCA7 is a copy number amplified gene identified not only in esophageal squamous cell carcinoma (ESCC) but also in various cancer types. Its clinical relevance and underlying mechanisms in ESCC have remained unknown. METHODS: Tissue microarray data was used to analyze its expression in 179 ESCC samples. The effects of CDCA7 on proliferation, colony formation, and cell cycle were tested in ESCC cells. Real-time PCR and Western blot were used to detect the expression of its target genes. Correlation of CDCA7 with its target genes in ESCC and various SCC types was analyzed using GSE53625 and TCGA data. The mechanism of CDCA7 was studied by chromatin immunoprecipitation (ChIP), luciferase reporter assays, and rescue assay. RESULTS: The overexpression of CDCA7 promoted proliferation, colony formation, and cell cycle in ESCC cells. CDCA7 affected the expression of cyclins in different cell phases. GSE53625 and TCGA data showed CCNA2 expression was positively correlated with CDCA7. The knockdown of CCNA2 reversed the malignant phenotype induced by CDCA7 overexpression. Furthermore, CDCA7 was found to directly bind to CCNA2, thus promoting its expression. CONCLUSIONS: Our results reveal a novel mechanism of CDCA7 that it may act as an oncogene by directly upregulating CCNA2 to facilitate tumor progression in ESCC.
RESUMO
Due to the lack of effective diagnostic markers and therapeutic targets, esophageal squamous cell carcinoma (ESCC) shows a poor 5 years survival rate of less than 30%. To explore the potential therapeutic targets of ESCC, we integrated and reanalyzed the mutation data of WGS (whole genome sequencing) or WES (whole exome sequencing) from a total of 1,145 samples in 7 large ESCC cohorts, including 270 ESCC gene expression data. Two new mutation signatures and 20 driver genes were identified in our study. Among them, AP3S1, MUC16, and RPS15 were reported for the first time. We also discovered that the KMT2D was associated with the multiple clinical characteristics of ESCC, and KMT2D knockdown cells showed enhanced cell migration and cell invasion. Furthermore, a few neoantigens were shared between ESCC patients. For ESCC, compared to TMB, neoantigen might be treated as a better immunotherapy biomarker. Our research expands the understanding of ESCC mutations and helps the identification of ESCC biomarkers, especially for immunotherapy biomarkers.