Effect of HSPA 8 on the biological function of NPC cells and its mechanism

Nasopharyngeal carcinoma (NPC) occurs at the lateral and top wall of the nasopharyngeal cavity and is the most prevalent malignant tumour of the otorhinolaryngology. Heat shock protein family A number 8 (HSPA8, also known as HSC70) is a member of the Heat Shock Protein 70 (HSP70) family, which is closely linked to the cellular response to stress and the progression of cancer. In this paper, we mainly studied the expression of HSPA 8 in NPC, the influence on the biological function of NPC cells and the preliminary mechanism. Quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) was used to verify the expression of HSPA8 in NPC cells. NPC cell models with HSPA8 overexpression and knockdown were successfully constructed using lentiviral transfection. CCK-8 assay was used to assess the effect of HSPA8 on the growth and proliferation of NPA cells; the role of HSPA8 on the migration and invasion ability of cells was explored by cell scratch assay and Transwell migration and invasion assay; in addition, flow cytometry was used to analyse the effect of HSPA8 on the apoptosis and cell cycle of NPC cells. High-throughput transcriptome sequencing (RNA-seq) was utilised. Differential genes were screened and the functions and pathways involved in these differential genes were further resolved. To lay the foundation for subsequent in-depth exploration of the effects of HSPA8-mediated autophagy (chaperone-mediated autophagy, CMA) on NPC progression. The results showed that HSPA8 expression was elevated in NPC cells. In addition, silencing HSPA8 expression inhibited NPC proliferation, migration and invasion, enhanced apoptosis and significantly blocked NPC cells in G2/M phase. Overexpression of HSPA8 had the opposite effect. Analysis of the sequencing results suggests that HSPA8 may regulate NPC development by mediating CMA. In conclusion, HSPA8 may be a pro-oncogenic factor that plays a key role in NPC development and is a new therapeutic target or prognostic indicator for nasopharyngeal carcinoma.