아데노신에 의해 유도되는 사람 유래 구강 편평암세포종인 YD-10B와 YD-38의 세포성 세포치사 기작

Abstract

Adenosine is known to purine nucleoside composed of adenine molecule attached to a ribose sugar molecule moiety. It is present in all biological organs, tissues, and cells. Adenosine has been shown to induce cell death in a variety of cancer cells via diverse cellular mechanism. It has been established that adenosine regulates cell proliferation, apoptosis, differentiation, angiogenesis and metastasis in many tumors such as breast, colon, leukemia, liver and melanoma. However, cellular mechanisms of cell death by adenosine in human oral squamous cell carcinoma (OSCC) has not been studied. This study investigated to understand a cellular mechanism of adenosine-induced cell death in the YD-10B and YD-38 human OSCC. To verify the cell viability and cytopathic effect of adenosine in YD-10B and YD-38 human OSCC, MTT assay and crystal violet staining were performed. Cell viability reduces to 50% of control level on 24 h at 3.0 mM treatment. And crystal violet staining showed that adenosine treatment reduced the cell staining. Moreover, to understand cellular mechanism underlying the apoptosis in YD-10B and YD-38, DNA fragmentation assay and western blot analysis were performed. A DNA ladder formation was found in cells adenosine (3.0 mM) treated cells. In western blot analysis, adenosine treatment consistently increased accumulation of Bax and decreased of Bcl-2. It also adenosine induced activation of caspase-9, the effector caspase-3 and PARP cleavage indicating the mitochondrial mediated apoptosis in YD-38. In order to investigate, whether the cellular mechanisms of adenosine involved in the regulation G1/S cell cycle arrest in YD-10B and YD-38, the expression G1/S cell cycle regulatory proteins such as CDK4, p15, p16 were examined. CDK4 protein level was downregulated but p15 and p16 protein levels were upregulated in adenosine (3 mM) treated cells in YD-10B. In contrast, G1/S cell cycle regulatory protiens levels were not changed in adenosine treated YD-38 cells. This data indicated that adenosine treatment induced the apoptosis in YD-10B and YD-38 cells. However, cell cycle arrest caused only in YD-10B not in YD-38 cells. The present study suggest that adenosine can induce cell death through G1/S cell cycle arrest and mitochondrial mediated apoptosis depend on cell contexts.