Adhesion Molecules as Potential Novel Biomarkers for Opioid Dependence

Background: Cell-cell adhesion is essential in maintaining the structure and function of an organ. Several adhesion molecules have recently been identified as associated with heroin dependence in both genetic and peripheral plasma studies. Methods and Results: We reviewed literature concerning studies on adhesion molecules in opioid addictions in rodents and human, including human genetic associations in different ethnic groups, and treatment responses to methadone maintenance treatment in heroin-dependent patients. Conclusion: Some important and novel findings were summarized and discussed. Adhesion molecules in the peripheral plasma, e.g., cadherin-2 (CDH2), may be biomarkers for both methadone treatment outcome and nectin 4 may be an indicator for continued opioid use. Neural cell adhesion molecule (NCAM) in the central nervous system may regulate opioid withdrawal and analgesic responses. Future studies to uncover the mechanisms underlying the involvement of adhesion molecules in the pathological process of addictions will be an important research direction in the field.