After intra-tibia tumor cell inoculation (TCI), we found that the increased expression of HDACs was negatively correlated with the decreased expression of MOR in the DRG following TCI.
Based on our previous observations that overexpression of MOR in human non-small cell lung cancer (NSCLC) cells increased tumor growth and metastasis, this study examined whether MOR regulates growth factor receptor signaling and epithelial mesenchymal transition (EMT) in human NSCLC cells.
RNA interfering or specific inhibitor was administered to downregulate the MOR in human hepato-cellular carcinoma cells and it was found that the proliferation of hepatocellular carcinoma cells was significantly inhibited with the increase of the apoptotic rate, while the cell cycle was blocked in G0/G1 phase and the tumor growth in the mice was retarded.
In vivo, overexpression of MOR in human bronchoalveolar carcinoma cells increased primary tumor growth rates in nude mice by approximately 2.5-fold and lung metastasis by approximately 20-fold compared with vector control cells (n = 4 per condition).