Abstract：Objective To evaluate the effect of an inhibitor of protein kinase CK2 on the radiosensitivity of human lung cancer cells. Methods The protein levels of CK2 α and β subunits in different lung cancer cell lines were measured by Western blot. Clonogenic assays were performed to assess the effect of a CK2 inhibitor, quinalizarin, on the radiosensitivity of lung adenocarcinoma A549 cells and large cell lung cancer H460 cells. The effects of the combination of quinalizarin and X-ray irradiation on the apoptosis and cell cycle of A549 and H460 cells were measured by flow cytometry. The differences between two groups were analyzed by analysis of variance and t-test. Results Western blot revealed that the α and β subunits of CK2 were overexpressed in non-small cell lung cancer cells (A549, H460, and H1650 cells), which were considered insensitive to X-ray irradiation, whereas a lower expression of these two subunits were found in small cell lung cancer cells (H446 cells), which were sensitive to X-ray irradiation. The clonogenic assays showed that A549 and H460 cells pre-exposed to quinalizarin had a significantly lower survival fraction compared with the control group and had a sensitization enhancement ratio greater than 1.0(D0 were 2.771 and 2.463 respectively). The combination of quinalizarin and X-ray irradiation did not increase the apoptosis of A549 and H460 cells (X-ray+Quinalizarin vs. Quinalizarin, A549, P=0.487 and H460, P=0.254), but caused significant G2/M arrest compared with under X-ray irradiation only (X-ray+Quinalizarin:X-ray, A549, P=0.000;H460, P=0.002 and X-ray+Quinalizarin:Quinalizarin, A549, P=0.000;H460, P=0.000). Conclusions Quinalizarin, as a CK2 inhibitor, can increase the radiosensitivity of non-small cell lung cancer cells.
Li Qianwen,Li Ke,Zhang Sheng et al. Effect of an inhibitor of protein kinase CK2 on radiosensitivity of human lung cancer cells[J]. Chinese Journal of Radiation Oncology, 2015, 24(6): 719-723.
[1] Siegel R,Ma J,Zou Z,et al. Cancer statistics,2014[J].CA Cancer J Clin,2014,64(1):9-29.DOI:10.3322/caac.21208. [2] Meggio F,Pinna LA.One-thousand-and-one substrates of protein kinase CK2?[J]. Faseb J,2003,17(3):349-368. [3] Daya-Makin M,Sanghera JS,Mogentale TL,et al. Activation of a tumor-associated protein kinase (p40TAK) and casein kinase 2 in human squamous cell carcinomas and adenocarcinomas of the lung[J].Cancer Res,1994,54(8):2262-2268. [4] Faust RA,Tawfic S,Davis AT,et al. Antisense oligonucleotides against protein kinase CK2-alpha inhibit growth of squamous cell carcinoma of the head and neck in vitro[J].Head Neck,2000,22(4):341-346. [5] Faust M,Montenarh M.Subcellular localization of protein kinase CK2.A key to its function?[J]. Cell Tissue Res,2000,301(3):329-340. [6] Olsten MEK,Canton DA,Zhang C,et al. The Pleckstrin homology domain of CK2 interacting protein-1 is required for interactions and recruitment of protein kinase CK2 to the plasma membrane[J].J Biol Chem,2004,279(40):42114-42127. [7] Cozza G,Mazzorana M,Papinutto E,et al. Quinalizarin as a potent,selective and cell-permeable inhibitor of protein kinase CK2[J].Biochem J,2009,421(3):387-395.DOI:10.1042/BJ20090069. [8] Yoshimoto Y,Olike T,Okonogi N,et al. Carbon-ion beams induced production of an immune mediator protein,high mobility group box 1,at levels comparable with X-ray irradiation[J].J Radiat Res,2015,56(3):509-14.DOI:10.1093/jrr/rrv007. [9] Zhang F,Zhang T,Teng ZH,et al. Sensitivity to gamma-irradiation-induced cell cycle arrest and apoptosis by the histone deacetylase inhibitor trichostatin A in non-small cell lung cancer (NSCLC) cells[J].Cancer Biol Ther,2009,8(9):823-831. [10] Litchfield DW.Protein kinase CK2:structure,regulation and role in cellular decisions of life and death[J].Biochem J,2003,369(Pt 1):1-15. [11] Olsten MEK,Litchfield DW.Order or chaos? An evaluation of the regulation of protein kinase CK2[J].Biochem Cell Biol,2004,82(6):681-93. [12] Wang G,Unger G,Ahmad KA,et al. Downregulation of CK2 induces apoptosis in cancer cells—a potential approach to cancer therapy[J].Mol Cell Biochem,2005,274(1-2):77-84. [13] Di Maira G,Brustolon F,Bertacchini J,et al. Pharmacological inhibition of protein kinase CK2 reverts the multidrug resistance phenotype of a CEM cell line characterized by high CK2 level[J].Oncogene,2007,26(48):6915-6926. [14] Vilk G,Saulnier RB,St Pierre R,et al. Inducible expression of protein kinase CK2 in mammalian cells. Evidence for functional specialization of CK2 isoforms[J].J Biol Chem,1999,274(20):14406-14414. [15] Lebrin F,Chambaz EM,Bianchini L.A role for protein kinase CK2 in cell proliferation:evidence using a kinase-inactive mutant of CK2 catalytic subunit alpha[J].Oncogene,2001,20(16):2010-2022. [16] Pagano MA,Andrzejewska M,Ruzzene M,et al. Optimization of protein kinase CK2 inhibitors derived from 4,5,6,7-tetrabromobenzimidazole[J].J med chem,2004,47(25):6239-6247. [17] Page P,LX Yang,Novel chemoradiosensitizers for cancer therapy[J].Anticancer Res,2010,30(9):3675-3682. [18] Lin YC,Hung MS,Lin CK,et al. CK2 inhibitors enhance the radiosensitivity of human non-small cell lung cancer cells through inhibition of stat3 activation[J].Cancer Biothr Radiopharm,2011,26(3):381-388.DOI:10.1089/cbr.2010.0917. [19] Yamane K,Kinsella TJ.CK2 inhibits apoptosis and changes its cellular localization following ionizing radiation[J].Cancer Res,2005,65(10):4362-4367. [20] Zwicker F,Ebert M,Huber PE,et al. A specific inhibitor of protein kinase CK2 delays gamma-H2Ax foci removal and reduces clonogenic survival of irradiated mammalian cells[J].Radiat Oncol,2011,6:15.DOI:10.1186/1748-717X-6-15. [21] Parsonsa JL,Dianovaa Ⅱ,Fincha D,et al. XRCC1 phosphorylation by CK2 is required for its stability and efficient DNA repair[J].DNA Repair,2010,9(7):835-841.DOI:10.1016/j.dnarep.2010.04.008. [22] Spycher C,Miller ES,Townsend K,et al. Constitutive phosphorylation of MDC1 physically links the MRE11-RAD50-NBS1 complex to damaged chromatin[J].J Cell Biol,2008,181(2):227-40.DOI:10.1083/jcb.200709008. [23] Koch CA,Agyei R,Galicia S,et al. Xrcc4 physically links DNA end processing by polynucleotide kinase to DNA ligation by DNA ligase IV[J].EMBO J,2004,23(19):3874-3885.
2015, Vol. 24 
