In vitro study | CEP-18770 effective inhibition of chymotrypsin, IC50 3.8nM. At the same time, CEP-18770 also slightly inhibited the activity of peptidyl transferase. The IC50 value of CEP-18770 is similar to bortezomib, and both inhibit chymotrypsin and caspase activity at low nanomolar concentrations. CEP-18770 inhibition of A2780 ovarian cancer cells, PC3 prostate cancer, H460 SC lung cancer, LoVo colon cancer, RPMI8226 multiple myeloma, HS-Sultan anaplastic non-Hodgkin lymphoma, IC50 were 13.7, 22.2, 34.2 11.3, 5.6 and 8.2 nM. CEP-18770 acts on some MM and chronic myelogenous leukemia cell lines K562, inhibiting the ubiquitin-protease pathway. CEP-18770 induced ubiquitin protein accumulation for more than 4 to 8 hours, an effect similar to that of bortezomib. Pretreatment with CEP-18770 completely inhibited the degradation of IκBα. CEP-18770 significantly inhibited the high level of NF-κB activity in RPMI-8226 and U266 cells. CEP-18770 acts on the MM cell line and inhibits NF-kB of the DNA binding activity in a time-and concentration-dependent manner, resulting in a decrease in the growth and survival of tumor cells mediated by some of the genes that regulate NF-κB, including IkB α, X-chromosome linked inhibitor of apoptosis protein (XIAP), TNF-α,IL-1β, cell adhesion molecule (ICAM1), and VEGF. The expression of NF-κB regulated genes and the regulation of bortezomib are associated with more favorable clinical responses, enhancing the potential prognostic value of CEP-18770 treatment. CEP-18770 apoptotic precursor activity on MM cells is not only active on tumor-promoted MM cell lines, but also active on primary MM, including relapsed and refractory patients, some of them have been treated with bortezomib. In addition, CEP-18770 in combination with melphalan or bortezomib synergistically inhibited MM cell viability. |
In vivo study | CEP-18770 sustained inhibition of tumor body weight, there is a dose related inhibition. CEP-18770 induced tumor regression compared to bortezomib treatment, with a dose-dependent relationship. There was a dose-related increase of CEP-18770 in tumor-free mice compared to bortezomib by Incidence Rate. Oral treatment CEP-18770 produced a significant reduction in tumor body weight. There was also a dose-related relationship between the more potent and durable inhibition of tumor protease activity by CEP-18770 compared to bortezomib. The maximal apoptotic signal of CEP-18770 was 2.5 times higher than that of bortezomib. CEP-18770 action on MM xenografts completely inhibited the growth of tumors sensitive to and resistant to melphalan. CEP-18770 in combination with bortezomib, and treatment with one of them alone, induced complete regression of tumors sensitive to bortezomib and significantly delayed regression of tumors against bortezomib. In the xenograft model, CEP-18770 was treated orally alone, also showing an anti-MM effect. |