Establishment of Human Neuroblastoma Cell-Line (SK-N-SH) as an In Vitro Model of Morphine Addiction

Morphine is a schedule II-controlled substance that used to allow the diminution of intra-operative, post-operative or chronic pain. However, its usage is limited due to addiction and overdose liabilities. Morphine was observed to cause tolerance, dependence and withdrawal in human. Justification: to date lack of scientific evidence of morphine addiction was carried out by using specific single human neuroblastoma cell-line (SK-N-SH). Therefore, this study was performed to establish the morphine addiction model in this cell line. The cells were exposed to morphine for 24 hrs before treatment with methadone, as an anti-withdrawal drug for subsequence 24 hours. The cytosolic fraction of the cell was used in different objectives including receptor affinity, withdrawal properties, endocytic machinery, desensitisation or internalisation and cellular adaptation. The result shows that morphine and methadone bind to the µ-opioid receptor. The morphine-treated cells were observed to increase the expression of addiction markers, have a low rate of the endocytic machinery, cause desensitisation of receptor and reduce cellular adaptation. Those changes by morphine were normalised by the treatment of methadone. As a whole, it is postulated that neuroblastoma cell line, SK-N-SH, can be used as an in-vitro model to demonstrate morphine addiction before animal and human testing.