Search

Proliferation and metastasis are significantly malignant characteristics of human lung cancer, but the underlying molecular mechanisms are poorly understood. Chromobox 4 (CBX4), a member of the Polycomb group (PcG) family of epigenetic regulatory factors, enhances cellular proliferation and promotes cancer cell migration. However, the effect of CBX4 in the progression of lung cancer is not fully understood. We found that CBX4 is highly expressed in lung tumours compared with adjacent normal tissues. Overexpression of CBX4 significantly promotes cell proliferation and migration in human lung cancer cell lines. The knockdown of CBX4 obviously suppresses the cell growth and migration of human lung cancer cells in vitro. Also, the proliferation and metastasis in vivo are blocked by CBX4 knockdown. Furthermore, CBX4 knockdown effectively arrests cell cycle at the G0/G1 phase through suppressing the expression of CDK2 and Cyclin E and decreases the formation of filopodia through suppressing MMP2, MMP9 and CXCR4. Additionally, CBX4 promotes proliferation and metastasis via regulating the expression of BMI-1 which is a significant regulator of proliferation and migration in lung cancer cells. Taken together, these data suggest that CBX4 is not only a novel prognostic marker but also may be a potential therapeutic target in lung cancer., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

IR‑783, a near‑infrared heptamethine cyanine dye, has been reported to possess cancer targeting and anticancer effects; Ηowever, the molecular mechanism by which IR‑783 exhibits anti‑breast cancer activity is unclear. In the present study, the inhibitory effects of IR‑783 on the proliferation and migration of breast cancer cells were investigated. Our results revealed that IR‑783 inhibited MDA‑MB‑231 and MCF‑7 cell proliferation in a dose‑ and time‑dependent manner by inducing cell cycle arrest at the G0/G1 phase. In addition, a Transwell assay demonstrated that IR‑783 treatment suppressed the migratory ability of MDA‑MB‑231 and MCF‑7 cells. Furthermore, IR‑783 treatment decreased the expression levels of matrix metalloproteinase (MMP)‑2 and MMP‑9 in MDA‑MB‑231 cells. Furthermore, IR‑783 induced MDA‑MB‑231 and MCF‑7 cell mitochondrial fission, and also decreased the levels of ATP. This was accompanied with a decrease in polymerized filamentous actin, which is the fundamental component of filopodia at the cell surface. Collectively, the results of the present study demonstrated that IR‑783 inhibited the proliferation and migration of MDA‑MB‑231 and MCF‑7 cells by inducing mitochondrial fission and subsequently decreasing ATP levels, resulting in cell cycle arrest and filopodia formation suppression. These findings suggest that IR‑783 may be developed into an effective novel drug for treating breast cancer.