The oncogenic effects of HES1 on salivary adenoid cystic carcinoma cell growth and metastasis.

Background: Our previous study demonstrated a close relationship between NOTCH signaling pathway and salivary adenoid cystic carcinoma (SACC). HES1 is a well-known target gene of NOTCH signaling pathway. The purpose of the present study was to further explore the molecular mechanism of HES1 in SACC.

Methods: Comparative transcriptome analyses by RNA-Sequencing (RNA-Seq) were employed to reveal NOTCH1 downstream gene in SACC cells. Immunohistochemical staining was used to detect the expression of HES1 in clinical samples. After HES1-siRNA transfected into SACC LM cells, the cell proliferation and cell apoptosis were tested by suitable methods; animal model was established to detect the change of growth ability of tumor. Transwell and wound healing assays were used to evaluate cell metastasis and invasion.

Results: We found that HES1 was strongly linked to NOTCH signaling pathway in SACC cells. The immunohistochemical results implied the high expression of HES1 in cancerous tissues. The growth of SACC LM cells transfected with HES1-siRNAs was significantly suppressed in vitro and tumorigenicity in vivo by inducing cell apoptosis. After HES1 expression was silenced, the SACC LM cell metastasis and invasion ability was suppressed.

Conclusions: The results of this study demonstrate that HES1 is a specific downstream gene of NOTCH1 and that it contributes to SACC proliferation, apoptosis and metastasis. Our findings serve as evidence indicating that HES1 may be useful as a clinical target in the treatment of SACC.