[Cdc37 Expression in Multiple Myeloma and Its Role in Cell Proliferation]

To investigate the expression of cell division cycle protein 37 (Cdc37) in multiple myeloma (MM) and its effect on MM cell proliferation.

The expression of Cdc37 mRNA in CD138⁺ cells derived from 63 newly diagnosed MM patients and 8 healthy people were detected by real-time quantitative PCR (RT-qPCR). Cdc37 was down-regulated by lentivirus in MM cell line NCI-H929. CCK-8 assay and soft agar clone formation assay were conducted to explore the role of Cdc37 on MM proliferation in vitro. To further verify the effect of Cdc37 on MM cell proliferation in vivo, NOD/SCID mice subcutaneous tumorigenesis model was established. Flow cytometry was carried out to explore the role of Cdc37 on cell cycle. Cell cycle associated proteins and NF-κB pathway were detected by Western blot (WB).

Cdc37 was highly expressed in newly diagnosed CD138⁺cells compared with healthy people. After Cdc37 suppression by shRNA lentivirus infection in NCI-H929 cells, the proliferation of MM cells were decreased in vitro and in vivo. Compared with the control group, the ratio of cells arrested in G₀/G₁ phase significantly increased in NCI-H929-Cdc37 shRNA cells, the expression of cyclin D1 decreased, while the expression of p21 and p53 was significantly up-regulated. Meanwhile, the activation of NF-κB signaling pathway was hampered in NCI-H929-Cdc37 shRNA cells.

Cdc37 is highly expressed in newly diagnosed MM patients. Inhibition of Cdc37 results in decreased proliferation activity and G₀/G₁ arrest in NCI-H929 cells. The possible mechanism may be to inhibit the activation of NF-κB signaling pathway.