The Significance of CD109 Expression in Oropharyngeal Squamous Cell Carcinoma

Background/Aim: Up-regulation of CD109 occurs in malignant tumours, although its role is unknown. Here we aimed to evaluate the significance of CD109 expression in oropharyngeal squamous cell carcinoma (OPSCC). Patients and Methods: Immunohistochemical analysis was performed to assess CD109 expression in 169 patients with OPSCC. We assessed the effects of small interfering RNA (siRNA)-mediated inhibition of CD109 expression on the proliferation and invasiveness of the human papillomavirus 16-positive (HPV16⁺) head and neck SCC cell line UM-SCC-47. Results: Expression of CD109 was associated with higher tumour differentiation in p16⁺ OPSCC (p=0.0036), and the CD109⁺ subgroup experienced significantly shorter progression-free survival (p=0.03). UM-SCC-47 cells with siRNA-mediated inhibition of CD109 expression showed reduced invasiveness (p=0.07). Conclusion: CD109 expression is associated with poor prognosis of HPV16⁺ OPSCCs.