Myc-oncogene inactivating effect by proline rich polypeptide (PRP-1) in chondrosarcoma JJ012 cells.

Proline rich polypeptide (PRP-1) produced by NPV and NSO cells is released into the general circulation and exerts its effect on the activity of immunocompetent and neuronal cells. PRP-1 is a unique regulator of hematopoiesis, stimulator of bone-marrow hematogenesis. Taking into consideration our preliminary data on antitumor and unique diverse biological properties of PRP-1 previously described by Galoyan et al., we proceeded with investigation of the PRP-1 effect on chondrosarcoma, the second most common malignancy in bone, which tends to be locally invasive and then metastatic. Currently it does not have any effective treatment and does not respond either to radiation or chemotherapy, leaving surgical resection as the only option. Our experimental results of PRP-1 action on human chondrosarcoma JJ012 cells demonstrated inactivation, abolishment of Myc oncogene activity usually upregulated in chondrosarcoma cells and other malignancies. The fact that addition of PRP-1 caused drastic inactivation of Myc-luc response element to the control level in human chondrosarcoma JJ012 cell line prompts to investigate further this neuropeptides powerful antioncogenic potential, opening up possibilities to consider PRP-1 as a potential therapeutic tool for chondrosarcoma treatment.