Suppression of Long Noncoding RNA SNHG1 Inhibits the Development of Hypopharyngeal Squamous Cell Carcinoma via Increasing PARP6 Expression.

Purpose: This study aimed to explore the function and molecular mechanism of long noncoding RNA Small Nucleolar RNA Host Gene 1 (SNHG1) in the development of hypopharyngeal squamous cell carcinoma (HSCC).

Methods: Human HSCC cell line FaDu was used in this study. Cell viability and apoptosis were detected using CCK-8 assay and flow cytometry, respectively. Cell migration and invasion were measured by Transwell assay. The expression of PARP6, XRCC6, β -catenin, and EMT-related proteins (E-cadherin and N-cadherin) were determined using western blotting. Moreover, the regulatory relationship between SNHG1 and PARP6 was investigated. Furthermore, the effects of the SNHG1/PARP6 axis on tumorigenicity were explored in vivo .

Results: Suppression of SNHG1 suppressed the viability, migration, and invasion but promoted apoptosis of FaDu cells in vitro ( P < 0.01). PARP6 is a target of SNHG1, which was upregulated by SNHG1 knockdown in FaDu cells ( P < 0.01). SNHG1 suppression and RARP6 overexpression inhibited FaDu cell proliferation, migration, and invasion ( P < 0.05). SNHG1 suppression and RARP6 overexpression also inhibited tumorigenicity of HSCC in vivo . Furthermore, the protein expression of E-cadherin was significantly increased and that of N-cadherin, β -catenin, and XRCC6 was dramatically decreased in HSCC after SNHG1 suppression or/and RARP6 overexpression both in vitro and in vivo ( P < 0.01).

Conclusions: SNHG1 silencing inhibits HSCC malignant progression via upregulating PARP6. XRCC6/ β -catenin/EMT axis may be a possible downstream mechanism of the SNHG1/PARP6 axis in HSCC. SNHG1/PARP6 can be used as a promising target for the treatment of HSCC.