Molecular mechanisms underlying antitumor activity of camel whey protein against multiple myeloma cells

Treating drug-resistant cancer cells is a clinical challenge and it is also vital to screen for new cancer drugs. Multiple myeloma (MM) is a plasma cell clonal cancer that, despite many experimental therapeutics, remains incurable. In this study, two MM cell line lines U266 and RPMI 8226 were used to determine the impact of camel whey protein (CWP). The CWP IC(50) was calculated by MTT examination, while the flow cytometry analysis was used to investigate the chemotaxis responses of MM cells in relation to CXCL12 and the pro-apoptotic effect of CHP. MM cells were treated with CWP and Western blot analysis was used to determine the underlying molecular mechanisms. Dose and time based on the impact of CWP on the cell viability of MM cells with IC(50) of 50 μg/ml, without affecting the viability of normal healthy PBMCs. CWP reduced chemotaxis of MM cells significantly from the CXC chemokine ligand 12 (CXCL12). Using Western blot analysis, we found that CWP decreased the activation of AKT, mTOR, PLCβ3, NFαB and ERK, which was mechanistically mediated by CXCL12/CXCR4. In both U266 and RPMI 8226, CWP induced apoptosis by upregulating cytochrome C expression. In addition, CWP mediated the growth arrest of MM cells by robustly decreasing the expression of the anti-apoptotic Bcl-2 family members Bcl-2, Bcl-XL and Mcl-1. Conversely, the expression of pro-apoptotic Bcl-2 family members Bak, Bax and Bim was increased after treatment with CWP. Our data indicates CWP's therapeutic potential for MM cells.