Pcdna3.1 plasmid vector

For knocking down the expression of LIMP-2, the specific shRNA against LIMP-2 (shLIMP-2) and control shRNA (shCtrl) were constructed and packaged by Ubigene Biosciences (Guangzhou, China). The specific targeting sequence was as follows: shLIMP-2 (mouse): 5’-GGGTCTATGGATGAGGGAA-3’. The 4MOSC2 and SCC7 cells were infected with polybrene and lentiviral supernatant and then screened with 4 μg·mL⁻¹ puromycin (Sigma‒Aldrich, USA). The Protein levels were verified using Western blot.
Full-length mouse LIMP-2 complementary DNA was PCR amplified and cloned into the pcDNA3.1 plasmid vector (Tsingke Biotechnology Co. Ltd., China). β-catenin-siRNA (5ʹ-UACAUCAUUUGUAUUCUGCTT-3ʹ), ATG5-siRNA (5ʹ- GCGGUUGAGGCUCACUUUATT-3ʹ), and ATG7-siRNA (5ʹ-GCUAGAGACGUGACACAUATT-3ʹ) were from GenePharma (Suzhou, China). The mRFP-GFP-LC3 plasmid were kindly donated by Dr. T Yoshimori and distributed by Addgene. All the plasmids were transfected into HNSCC cells using Lipofectamine™ 3000 following protocol (Invitrogen, USA).

All cell lines were obtained from the Procell Life Science&Technology and authenticated by STR profiling, then cultured in DMEM (Thermo, Shanghai, China) at 37°C with 5% CO₂. Interference of LncRNA SNHG1 was performed using siRNA (si-SNHG1-1, si-SNHG1-2) sequences synthesized by Tsingke Biotechnology (Beijing, China). For LncRNA SNHG1 overexpression, pcDNA3.1-SNHG1 and pcDNA3.1 plasmid vector (NC) were constructed by Tsingke Biotechnology. For miRNA function studies, miRNA mimics (miR497-mimics) and negative control miRNA mimics (miR497-NC) were purchased from Tsingke Biotechnology, the final concentration of the mimics was 50 nM. Cells were transfected with Lipofectamine 3000 (Invitrogen, Shanghai, China) and harvested at 72h according to the manufacturer′s instruction.