As a kind of inorganic metal-oxide cluster compound, polyoxometalates' potential antitumor activities have gained much attention. In this paper, the bioactivities of a series of rare earth substituted phosphotungstic acids containing 5-fluorouracil, K9(C4H4FN2O2)2La(PW11O39)2·18H2O, K9(C4H4FN2O2)2Ce(PW11O39)2·23H2O, K9(C4H4FN2O2)2Nd(PW11O39)2·25H2O, K9(C4H4FN2O2)2Sm(PW11O39)2·11H2O and K9H(C4H4FN2O2)Eu(PW11O39)2·11H2O (abbr. FLnPW, Ln=La, Ce, Nd, Sm, Eu) on HeLa cell are investigated. 5-fluorouracil (abbr. 5-FU) is used as positive control, and phosphotungstate containing 5-fluroracil K11C4H4FN2O2(PW11O39)·7H2O (abbr. FPW) and phosphotungstic acid H3PW12O40 (abbr. PW) are also tested. Morphological analysis shows that typical characteristics of apoptosis appear after treatment with the above compounds (besides PW), and nuclear chromatin is highly concentrated and marginalized. Flow cytometry indicates that S phase cell cycle arrest is induced by compounds (besides PW), whose FPW shows higher S-phase arrest activity than 5-FU, and that the FCePW, FNdPW and FEuPW groups show S phase and G2/M phase arrests simultaneously. Flow cytometry also shows that all compounds except PW induce apoptosis in HeLa cells, and that the apoptosis-inducing activity order is FLnPW > FPW > 5-FU. Caspase 3 detection shows that caspase 3 activity of HeLa cell is enhanced after treatment with compounds, and the caspase 3 activity order is FLnPW>FPW>5-FU, where the FCePW and FEuPW groups show significant higher activities. These results show that the above compounds containing 5-FU group possess cell cycle arrest activity, apoptosis-inducing activity and caspase 3 inducing activity, while PW could only cause cell death because of acidity. It is suggested that 5-FU group and rare earth elements play most important roles in the antitumor activity, and FLnPW could inhibit cell proliferation by inducing cell cycle arrest, activating the caspase 3-dependent apoptosis pathway.
[1] Liu X, Gan Q, Feng C G. Synthesis, characterization and antitumor ac-tivity of rare earth (Y, La) substituted phosphotungstates containing 5-fluorouracil[J]. Journal of Rare Earths, 2012, 30(6):604-608.
[2] 刘杰, 王恩波, 计亮年. 多金属氧酸盐抗病毒药物研究[J]. 化学进展, 2006, 18(1):114-119. Liu Jie, Wang Enbo, Ji Liangnian. The development of polyoxometa-lates as antivirus drugs[J]. Progress in Chemistry, 2006, 18(1):114-119.
[3] Feng C G, Xiong Y D, Liu X. Synthesis, spectroscopy and antibacterial activity of supermolecular compounds of organotitanium substituted het-eropolytungstates containing 8-quinolinol[J]. Spectroscopy and Spectral Analysis, 2011, 31(5):1153-1160.
[4] Hasenknopf B. Polyoxometalates:Introduction to a class of inorganic compounds and their biomedical applications[J]. Frontiers in Biosci-ence, 2005, 10(1):275-287.
[5] Mialane P, Dolbecq A, Secheresse F. Functionalization of polyoxometa-lates by carboxylato and azido ligands:Macromolecular complexes and extended compounds[J]. Chemical Communications, 2006(33):3477-3485.
[6] Yamase T, Fujita H, Fukushima K. Medical chemistry of polyoxometa-lates. Part 1. Potent antitumor activity of polyoxomolybdates on animal transplantable tumors and human cancer xenograft[J]. Inorganica Chimi-ca Acta, 1988, 151(1):15-18.
[7] Ogata A, Mitsui S, Yanagie H, et al. A novel anti-tumor agent, polyoxo-molybdate induces apoptotic cell death in AsPC-1 human pancreatic cancer cells[J]. Biomedicine & Pharmacotherapy, 2005, 59(5):240-244.
[8] Mitsui S, Ogata A, Yanagie H, et al. Antitumor activity of polyoxomolyb-date,[NH3Pri]6[Mo7O24]·3H2O, against, human gastric cancer model[J]. Biomedicine & Pharmacotherapy, 2006, 60(7):353-358.
[9] 张学军, 常雅萍, 刘建辉, 等. 甘氨酸-钼磷酸盐抗肿瘤作用的机理研究[J]. 免疫学杂志, 2002, 18(5):404-405. Zhang Xuejun, Chang Yaping, Liu Jianhui, et al. Anti-tumor activity and mechanism of GP[J]. Immunological Journal, 2002, 18(5):404-405.
[10] Ogata A, Yanagie H, Ishikawa E, et al. Antitumour effect of polyoxo-molybdates:induction of apoptotic cell death and autophagy in in vitro and in vivo models[J]. British Journal of Cancer, 2008, 98(2):399-409.
[11] Sun X, Wu Y, Gao W, et al. CD39/ENTPD1 expression by CD4+ Foxp3+ regulatory T cells promotes hepatic metastatic tumor growth in mice[J]. Gastroenterology, 2010, 139(3):1030-1040.
[12] 张松龄, 梅少林, 常雅萍. 三取代型钛钨硅酸盐体内抑瘤效应的免疫机制探讨[J]. 细胞与分子免疫学杂志, 2005, 21(5):650-652. Zhang Songlin, Mei Shaolin, Chang Yaping, et al. Investigation of im-munological mechanism of the in vivo antitumor effect of K8(C6H11N3O2)2[SiW9Ti3O40] (W T)[J]. Chinese Journal of Cellular and Molecular Immu-nology, 2005, 21(5):650-652.
[13] Seko A, Yamase T, Yamashita K. Polyoxometalates as effective inhibi-tors for sialyl-and sulfotransferases[J]. Journal of Inorganic Biochemis-try, 2009, 103(7):1061-1066.
[14] Müller C E, Iqbal J, Baqi Y, et al. Polyoxometalates-a new class of po-tent ecto-nucleoside triphosphate diphosphohydrolase (NTPDase) in-hibitors[J]. Bioorganic & Medicinal Chemistry Letters, 2006, 16(23):5943-5947.
[15] Wood P A, Du-Quiton J, You S, et al. Circadian clock coordinates cancer cell cycle progression, thymidylate synthase, and 5-fluorouracil therapeutic index[J]. Molecular Cancer Therapeutics, 2006, 5(8):2023-2033.
[16] Zhang N, Yin Y, Xu S J, et al. 5-fluorouracil:Mechanisms of resis-tance and reversal strategies[J]. Molecules, 2008, 13(8):1551-1569.
[17] Hakan A, Osman N. Antitumor effects of TNF-β, 5-FU and their com-binations on cervica carcinoma cell lines[J]. Turkish Journal of Medi-cal Sciences, 2002, 32(2):127-132.
[18] Liu X, Wang S S, Feng C G. Synthesis and anticancer properties of rare earth substituted tungstophosphoric polyoxometalate containing 5-fluorouracil[J]. Chinese Journal of Chemistry, 2010, 28(12):2411-2415.
[19] Liu X, Wang S S, Feng C G. Synthesis and anticancer properties of tungstosilicic polyoxometalate containing 5-fluorouracil and neodymi-um[J]. Journal of Rare Earths, 2010, 28(6):965-968.
[20] Feng C G, Gan Q, Liu X, et al. Synthesis, antitumor and apoptosis in-ducing activities of novel 5-fluorouracil derivatives of rare earth (Sm, Eu) substituted polyoxometalates[J]. Chinese Journal of Chemistry, 2012, 30(7):1589-1593.
[21] Feng C G, Gan Q, Liu X, et al. Synthesis and antitumor activities of rare earth substituted phosphotungstates containing 5-fluorouracil[J]. Journal of Rare Earths, 2012, 30(5):467-472.
[22] Liu X, Gan Q, Feng C G. Synthesis, characterization and antitumor ac-tivity of rare earth (Y, La) substituted phosphotungstates containing 5-fluorouracil[J]. Journal of Rare Earths, 2012, 30(6):604-608.
[23] Majno G, Joris I. Apoptosis, oncosis, and necrosis-an overview of cell death[J]. American Journal of Pathology, 1995, 146(1):3-15.
[24] Van Cruchten S, Van Den Broeck W. Morphological and biochemical aspects of apoptosis, oncosis and necrosis[J]. Anatomia Histologia Em-bryologia-Journal of Veterinary Medicine Series C, 2002, 31(4):214-223.
[25] Cristea I M, Degli Esposti M. Membrane lipids and cell death:an over-view[J]. Chemistry and Physics of Lipids, 2004, 129(2):133-160.
[26] Jin Z Y, El-Deiry W S. Overview of cell death signaling pathways[J]. Cancer Biology& Therapy, 2005, 4(2):139-163.
[27] Wang X H, Liu J F, Chen Y G, et al. Synthesis, characterization and biological activity of organotitanium substituted heteropolytungstates[J]. Dalton Transactions, 2000(7):1139-1142.
[28] 刘景福, 陈亚光, 马建方, 等. 穴状稀土杂多化合物的生物活性研究[J]. 中国稀土学报, 2000, 18(3):282-285. Liu Jingfu, Chen Yaguang, Ma Jianfang, et al. Biological activity of cryptate lanthanide polyoxometalates[J]. Journal of the Chinese Rare Earth Society, 2000, 18(3):282-285.
[29] Yanagie H, Ogata A, Mitsui S, et al. Anticancer activity of polyoxomo-lybdate[J]. Biomedicine & Pharmacotherapy, 2006, 60(7):349-352.
[30] 伊万·科热夫尼科夫. 精细化学品的催化合成:多酸化合物及其催化[M]. 北京:化学工业出版社, 2005. IV Kozhevnikov. Catalysis for fine chemical synthesis:Catalysis by polyoxometalates[M]. Beijing:Chemical Industry Press, 2005.
[31] Sato T, Hashizume M, Hotta Y, et al. Morphology and proliferation of B16 melanoma cells in the presence of lanthanoid and Al3+ ions[J]. Biometals, 1998, 11(2):107-112.
[32] Dai Y, Li J, Li J, et al. Effects of rare earth compounds on growth and apoptosis of leukemic cell lines[J]. In Vitro Cellular & Developmental Biology-Animal, 2002, 38(7):373-375.
[33] 黄春晖. 稀土配位化学[M]. 北京:科学出版社, 1997. Huang Chunhui. Rare earth coordination chemistry[M]. Beijing:Sci-ence Press, 1997.
[34] Liu X, Gan Q, Feng C. Synthesis, characterization and biological activ-ity of 5-fluorouracil derivatives of rare earth (Gd, Dy, Er) substituted phosphotungstate[J]. Inorganica Chimica Acta, 2016, 450:299-303.