A3 adenosine receptor antagonist, truncated Thio-Cl-IB-MECA, induces apoptosis in T24 human bladder cancer cells.

BACKGROUND

Human A(3) adenosine receptor (A(3)AR) plays an essential role in several physiopathological processes. Thus far, A(3)AR-selective ligands have been evaluated as anti-inflammation and anticancer therapeutic agents. Among these ligands, truncated thio-Cl-IB-MECA is a newly reported antagonist, and its function has not been studied.

METHODS

Cell viability was measured by MTS assay. Cell cycle progression was analysed by propidium iodide (PI) flow cytometric assay. The apoptotic effects were investigated by Hoechst staining and annexin V-FITC/PI staining. The signal-transduction mechanism was explored by Western blot.

RESULTS

Truncated thio-Cl-IB-MECA induced the growth arrest of T24 cells at sub-G(1) phase and provoked apoptosis but not necrosis. Apoptotic death was mediated by the activation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK).

CONCLUSIONS

Since truncated thio-Cl-IB-MECA induces anti-proliferation and apoptotic effects via ERK and JNK activation, it may function as an anticancer agent in human bladder cancer cells.