Abstract
Background: Oral squamous cell carcinoma (OSCC) refers to the malignant tumor of the head and neck with a highest morbidity. It exhibits a poor prognosis and unsatisfactory treatment, which is partially attributed to delayed diagnosis. As indicated from existing reports, the protein histidine phosphatase LHPP acts as a vital factor in tumorigenesis in liver, lung, bladder, breast and pancreatic tumor tissues. Thus far, the expression level of LHPP in OSCC has been rarely studied, and its functional mechanism remains unclear. Methods: DEG analysis, OSCC cell lines and OSCC samples were used to detect the expression of LHPP in adjacent normal and cancerous tissues and its relationship with OSCC differentiation. Immunofluorescence staining was used to detect the over-expressed LHPP in OSCC cell lines. The cell counting kit 8 test, EdU proliferation test, scratch test, invasion test, single clone formation test, mouse xenograft tumor model HE staining and immunohistochemistry were used to estimate the biological characteristics of LHPP in OSCC in vivo and in vitro. GO and KEGG enrichment analysis and LHPP transcription factor analysis were used to further predict the role of LHPP and its related genes. The Western blotting assay, real-time PCR analysis and flow cytometry determined the inhibitory mechanism of LHPP in OSCC cells.Results: LHPP was down-regulated in OSCC tissues and cells than that in normal oral mucosa tissues and cells, LHPP expressing also displays a close association with the degree differentiation of OSCC. LHPP is capable of significantly inhibiting OSCC cells from proliferating, migrating and invading. The increase in LHPP expression facilitated OSCC cell apoptosis through PI3K/AKT signaling pathway.Conclusion: LHPP is a novel tumor suppressor which promotes apoptosis by inhibiting the PI3K/AKT signaling pathway in OSCC, indicating that LHPP is a new diagnostic marker and therapeutic target for OSCC.
Mecambridine induces potent cytotoxic effects, autophagic cell death and modulation of the mTOR/PI3K/Akt signaling pathway in HSC‑3 oral squamous cell carcinoma cells