STAT3 and Its Targeting Inhibitors in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) usually originates from the precancerous lesions of oral mucosa and accounts for approximately 90% of oral cancers. Current therapeutic approaches do not yet meet the needs of patients, and the 5-year survival rate of patients with OSCC is only 50%. Recent studies have revealed that the signal transducer and activator of transcription 3 (STAT3) plays a key role in the development and progression of OSCC. STAT3 is overexpressed and constitutively activated in OSCC cells, and promotes cancer cell proliferation and anti-apoptosis, migration and invasion, angiogenesis, radiotherapy resistance, and immune escape, as well as stem cell self-renewal and differentiation by regulating the transcription of its downstream target genes. Inhibitors of the STAT3 signaling pathway have shown the promising anticancer effects in vitro and in vivo, and STAT3 is expected to be a molecular target for the treatment of OSCC. In this review, we highlight the oncogenic significance of STAT3 in OSCC with an emphasis on the therapeutic approaches and effective small molecule inhibitors targeting STAT3. Finally, we also propose the potential research directions in the expectation of developing more specific STAT3 inhibitors for OSCC treatment.