Identification and characterization of ANO9 in stage II and III colorectal carcinoma

Background and Objectives: The precise role and potential underlying mechanisms of anoctamin 9 (ANO9) remain largely unknown. This study aims to characterize the role and oncogenic mechanisms of ANO9 in stage II and III colorectal cancer (CRC). Methods: We examined the expression of ANO9 in colorectal cancerous tissues and cells using real-time quantitative PCR and immunohistochemistry, respectively. Multiple cellular and molecular approaches such as gene transfection, CCK-8 assay, flow cytometry, and invasion assay were also performed to explore its oncogenic mechanisms. Furthermore, the clinical significance of ANO9 in clinical CRC specimens was assessed by clinical correlation and survival analyses. Results: Lower expression of ANO9 messenger RNA (mRNA) was frequently detected both in CRC tissues with recurrence and metastasis-derived cell lines. Compared with matched nontumorous tissues, lower expression of ANO9 protein was observed in tumors, which was significantly correlated with tumorigenesis (p < 0.05). In vitro functional studies showed that ANO9 contributed to tumor cell proliferation, apoptosis, and invasion. Moreover, investigation of clinical CRC specimens showed that ANO9 were markedly overexpressed in metastatic tissue compared with primary tissue. Decreased expression of ANO9 was correlated with poor prognostic outcomes. Conclusions: This study highlighted the role of ANO9 in progression and metastasis of stage II and III CRC. These findings suggested that up-regulation of ANO9, as a metastasis-related gene, could be a novel approach for inhibiting CRC progression.