Microenvironmental regulation of the progression of oral potentially malignant disorders towards malignancy

// Ruixue Ai 1 , Yan Tao 1 , Yilong Hao 1 , Lu Jiang 1 , Hongxia Dan 1 , Ning Ji 1 , Xin Zeng 1 , Yu Zhou 1 and Qianming Chen 1 1 State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Oral Medicine of West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China Correspondence to: Yu Zhou, email: zhouyu19830306@sina.com Qianming Chen, email: qmchen@scu.edu.cn Keywords: immunity, premalignant condition, microenvironment, oral potentially malignant disorder, therapeutics Received: May 24, 2017      Accepted: August 04, 2017      Published: August 17, 2017 ABSTRACT Oral potentially malignant disorders (OPMD) develop in a complex tissue microenvironment where they grow sustainably, acquiring oral squamous cell carcinoma (OSCC) characteristics. The malignant tumor depends on interactions with the surrounding microenvironment to achieve loco-regional invasion and distant metastases. Unlike abnormal cells, the multiple cell types in the tissue microenvironment are relatively stable at the genomic level and, thus, become therapeutic targets with lower risk of resistance, decreasing the risk of OPMD acquiring cancer characteristics and carcinoma recurrence. However, deciding how to disrupt the OPMD and OSCC microenvironments is itself a daunting challenge, since their microenvironments present opposite capacities, resulting in diverse consequences. Furthermore, recent studies revealed that tumor-associated immune cells also participate in the process of differentiation from OPMD to OSCC, suggesting that reeducating stromal cells may be a new strategy to prevent OPMD from acquiring OSCC characteristics and to treat OSCC. In this review, we discuss the characteristics of the microenvironment of OPMD and OSCC as well as new therapeutic strategies.