tRNA和其衍生物的失調會透過增強癌細胞分化、轉移及侵襲的能力來影響癌症的進程；細胞週期失調則會藉由影響RNA polymerase III轉錄活性，來干擾tRNA的生成，進而參與腫瘤的發展。Aurora-A為重要的細胞週期蛋白激酶，於有絲分裂期間調控中心體的分離，在許多癌症中皆有過度表現的現象。Maf1是一個於細胞核、細胞質間移動的磷酸化蛋白，於細胞核內的功能為抑制RNA polymerase III的轉錄活性，在細胞質中的功能則仍不清楚。Maf1的磷酸化及在細胞中的分佈，是影響其活性和功能的兩大要素。本研究發現， Aurora-A透過與Maf1蛋白的C結構域交互作用，將Maf1蛋白留於細胞質中，並增加其蛋白的穩定性且兩者之間的相互作用會受到Aurora-A激酶活性的影響。過度表現Aurora-A可以回復被Maf1所抑制的tRNA生合成現象。在過度表現Aurora-A的細胞中給予ferroptosis的誘導化合物RSL3，發現會降低細胞存活率；這可能是Aurora-A負調控Maf1導致。在Aurora-A大量表現的細胞中處理ferroptosis的誘導物，Aurora-A可以透過與Maf1的交互作用，將Maf1保留在細胞質中，間接增加細胞的ferroptosis。未來或許同時使用Aurora-A抑制劑與ferroptosis誘導劑，做為癌症治療的新穎性治療策略。

Dysregulation of tRNAs and their derivatives can regulate the proliferation, metastasis and invasion of cancer cells; previous studies have demonstrated cell cycle dysregulation may enhance the transcription activity of RNA polymerase III to interfere with tRNA synthesis and promote cancer progression. Aurora-A kinase is an important cell cycle regulator involved in centrosome segregation during mitosis and is overexpressed in a variety of cancers. Maf1 is a shuttle phosphoprotein negatively regulating RNA polymerase III. Both phosphorylation status and subcellular localization can determine the activity of Maf1. Our study indicated that overexpression of Aurora-A can retain more Maf1 protein in the cytosol, and prolong the protein stability of Maf1 via interacting with its C-domain in a kinase-dependent manner. Co-expression of Aurora-A can reverse the tRNA synthesis activity in Maf1-overexpressing cells. Interestingly, when cells were treated with ferroptosis inducer RSL3, overexpressed Aurora-A could enhance cell sensitivity to RSL3 treatment via negatively regulating the Maf1 function. Taken together, our results present that Aurora-A can increase ferroptosis via retaining Maf1 in the cytoplasm through directly interacting with its C-domain; the combined treatment of Aurora-A inhibitors and ferroptosis inducers may provide a potential future therapeutic strategy in cancer treatment.

Abou-Alfa, G.K., Meyer, T., Cheng, A.L., El-Khoueiry, A.B., Rimassa, L., Ryoo, B.Y., Cicin, I., Merle, P., Chen, Y., Park, J.W., Blanc, J.F., Bolondi, L., Klümpen, H.J., Chan, S.L., Zagonel, V., Pressiani, T., Ryu, M.H., Venook, A.P., Hessel, C., Borgman-Hagey, A.E., Schwab, G., and Kelley, R.K. Cabozantinib in Patients with Advanced and Progressing Hepatocellular Carcinoma. New England Journal of Medicine 379, 54-63, 2018a.

Abou-Alfa, G.K., Meyer, T., Cheng, A.L., El-Khoueiry, A.B., Rimassa, L., Ryoo, B.Y., Cicin, I., Merle, P., Park, J.W., Blanc, J. F., Bolondi, L., Klümpen, H.J., Chan, S.L., Dadduzio, V., Hessel, C., Borgman-Hagey, A.E., Schwab, G., and Kelley, R.K. Cabozantinib (C) versus placebo (P) in patients (pts) with advanced hepatocellular carcinoma (HCC) who have received prior sorafenib: Results from the randomized phase III CELESTIAL trial. Journal of Clinical Oncology 36, 207, 2018b.

Ahn, C.S., Lee, D.H., and Pai, H.S. Characterization of Maf1 in Arabidopsis: function under stress conditions and regulation by the TOR signaling pathway. Planta 249, 527-542, 2019.

Bagchi, S., Fredriksson, R., and Wallén-Mackenzie, Å. In Situ Proximity Ligation Assay (PLA). Methods in Molecular Biology 1318, 149-159, 2015.

Becker, S., Groner, B., and Müller, C.W. Three-dimensional structure of the Stat3beta homodimer bound to DNA. Nature 394, 145-151, 1998.

Bradford, M.M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry 72, 248-254, 1976.

Casari, I., Domenichini, A., Sestito, S., Capone, E., Sala, G., Rapposelli, S., and Falasca, M. Dual PDK1/Aurora Kinase A Inhibitors Reduce Pancreatic Cancer Cell Proliferation and Colony Formation. Cancers (Basel) 11,1695,2019.

Chomczynski, P., and Sacchi, N. The single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction: twenty-something years on. Nature Protocols 1, 581-585, 2006.

Chu, J., Cargnello, M., Topisirovic, I., and Pelletier, J. Translation Initiation Factors: Reprogramming Protein Synthesis in Cancer. Trends in Cell Biology 26, 918-933, 2016.
Crane, R., Gadea, B., Littlepage, L., Wu, H., and Ruderman, J.V. Aurora A, meiosis and mitosis. Biology Cell 96, 215-229, 2004.

Dixon, S.J., Lemberg, K.M., Lamprecht, M.R., Skouta, R., Zaitsev, E.M., Gleason, C.E., Patel, D.N., Bauer, A.J., Cantley, A.M., Yang, W.S., Morrison, B., 3rd, and Stockwell, B.R. Ferroptosis: an iron-dependent form of nonapoptotic cell death. Cell 149, 1060-1072, 2012.

Duan, Z., Tan, X., Parajuli, K., Upadhyay, S., Zhang, D., Shu, X., and Liu, Q. Colony formation in two Microcystis morphotypes: Effects of temperature and nutrient availability. Harmful Algae 72, 14-24, 2018.

Dunkler, D., Sánchez-Cabo, F., and Heinze, G. Statistical analysis principles for Omics data. Methods in Molecular Biology 719, 113-131, 2011.

Grewal, S.S. Why should cancer biologists care about tRNAs? tRNA synthesis, mRNA translation and the control of growth. Biochimica et Biophysica Acta 1849, 898-907, 2015.

Gritsko, T.M., Coppola, D., Paciga, J.E., Yang, L., Sun, M., Shelley, S.A., Fiorica, J.V., Nicosia, S.V., and Cheng, J.Q. Activation and overexpression of centrosome kinase BTAK/Aurora-A in human ovarian cancer. Clinical Cancer Research 9, 1420-1426, 2003.

Hawkins, S.F., and Guest, P.C. Multiplex Analyses Using Real-Time Quantitative PCR. Methods in Molecular Biology 1546, 125-133, 2017.

Herrera, M.C., Chymkowitch, P., Robertson, J.M., Eriksson, J., Bøe, S.O., Alseth, I., and Enserink, J.M. Cdk1 gates cell cycle-dependent tRNA synthesis by regulating RNA polymerase III activity. Nucleic Acids Research 46, 11698-11711, 2018.

Huang, S.Q., Sun, B., Xiong, Z.P., Shu, Y., Zhou, H.H., Zhang, W., Xiong, J., and Li, Q. The dysregulation of tRNAs and tRNA derivatives in cancer. Journal of Experimental and Clinical Cancer Research 37, 101, 2018.

Johnson, E.O., Chang, K.H., de Pablo, Y., Ghosh, S., Mehta, R., Badve, S., and Shah, K. PHLDA1 is a crucial negative regulator and effector of Aurora A kinase in breast cancer. Journal of Cell Sciences 124, 2711-2722, 2011.

Johnson, E.O., Chang, K.H., Ghosh, S., Venkatesh, C., Giger, K., Low, P.S., and Shah, K. LIMK2 is a crucial regulator and effector of Aurora-A-kinase-
mediated malignancy. Journal of Cell Sciences 125, 1204-1216, 2012.

Kirchner, S., and Ignatova, Z. Emerging roles of tRNA in adaptive translation, signalling dynamics and disease. Nature Review.Genetics 16, 98-112, 2015.

Kurien, B.T., and Scofield, R.H. Western blotting: an introduction. Methods in Molecular Biology 1312, 17-30, 2015.

Kushi, L., and Giovannucci, E. Dietary fat and cancer. The American Journal of Medicine 113, 63-70, 2002.

Li, J., Cao, F., Yin, H.l., Huang, Z.j., Lin, Z.t., Mao, N., Sun, B., and Wang, G. Ferroptosis: past, present and future. Cell Death and Disease 11, 88, 2020.

Liang, C., Zhang, X., Yang, M., and Dong, X. Recent Progress in Ferroptosis Inducers for Cancer Therapy. Advanced Materials 31, e1904197, 2019.

Lin, J.S., and Lai, E.M. Protein-Protein Interactions: Co-Immunoprecipitation. Methods in Molecular Biology 1615, 211-219, 2017.

Llovet, J.M., Ricci, S., Mazzaferro, V., Hilgard, P., Gane, E., Blanc, J.F., de Oliveira, A.C., Santoro, A., Raoul, J.L., Forner, A., Schwartz, M., Porta, C., Zeuzem, S., Bolondi, L., Greten, T.F., Galle, P.R., Seitz, J.F., Borbath, I., Häussinger, D., Giannaris, T., Shan, M., Moscovici, M., Voliotis, D., and Bruix, J. Sorafenib in Advanced Hepatocellular Carcinoma. New England Journal of Medicine 359, 378-390, 2008.

Lo Iacono, M., Monica, V., Saviozzi, S., Ceppi, P., Bracco, E., Papotti, M., and Scagliotti, G.V. Aurora Kinase A expression is associated with lung cancer histological-subtypes and with tumor de-differentiation. Journal of Translational Medicine 9, 100, 2011.

Michels, A.A., Robitaille, A.M., Buczynski-Ruchonnet, D., Hodroj, W., Reina, J.H., Hall, M.N., and Hernandez, N. mTORC1 directly phosphorylates and regulates human MAF1. Molecular and Cellular Biology 30, 3749-3757, 2010.

Nadler, Y., Camp, R.L., Schwartz, C., Rimm, D.L., Kluger, H.M., and Kluger, Y. Expression of Aurora A (but not Aurora B) is predictive of survival in breast cancer. Clinical Cancer Research 14, 4455-4462, 2008.

Newcomb, P.A., and Carbone, P.P. The health consequences of smoking. Cancer. The Medical Clinics of North America 76, 305-331, 1992.

Nouri, M., Ratther, E., Stylianou, N., Nelson, C.C., Hollier, B.G., and Williams, E.D. Androgen-targeted therapy-induced epithelial mesenchymal plasticity and neuroendocrine transdifferentiation in prostate cancer: an opportunity for intervention. Frontiers in Oncology 4, 370, 2014.

Oler, A.J., and Cairns, B.R. PP4 dephosphorylates Maf1 to couple multiple stress conditions to RNA polymerase III repression. European Molecular Biology Organization Journal 31, 1440-1452, 2012.

Parsa, N. Environmental factors inducing human cancers. Iranian Journal of Public Health 41, 1-9, 2012.

Peach, M., Marsh, N., Miskiewicz, E.I., and MacPhee, D.J. Solubilization of proteins: the importance of lysis buffer choice. Methods in Molecular Biology 1312, 49-60, 2015.

Pihan, G.A., Purohit, A., Wallace, J., Malhotra, R., Liotta, L., and Doxsey, S.J. Centrosome defects can account for cellular and genetic changes that characterize prostate cancer progression. Cancer Research 61, 2212-2219, 2001.

Pradhan, A., Hammerquist, A.M., Khanna, A., and Curran, S.P. The C-Box Region of MAF1 Regulates Transcriptional Activity and Protein Stability. Journal of Molecular Biology 429, 192-207, 2017.

Ratna, A., and Mandrekar, P. Alcohol and Cancer: Mechanisms and Therapies. Biomolecules 9,1-20, 2017.

Reina, J.H., Azzouz, T.N., and Hernandez, N. Maf1, a new player in the regulation of human RNA polymerase III transcription. Public Library of Science One 1,e134, 2006.

Sakakura, C., Hagiwara, A., Yasuoka, R., Fujita, Y., Nakanishi, M., Masuda, K., Shimomura, K., Nakamura, Y., Inazawa, J., Abe, T., and Yamagishi, H. Tumour-amplified kinase BTAK is amplified and overexpressed in gastric cancers with possible involvement in aneuploid formation. British Journal of Cancer 84, 824-831, 2001.

Santos, M., Fidalgo, A., Varanda, A.S., Oliveira, C., and Santos, M.A.S. tRNA
Deregulation and Its Consequences in Cancer. Trends in Molecular Medicine 25, 853-865, 2019.

Schiller, J.T., and Lowy, D.R. Virus infection and human cancer: an overview. Recent Results Cancer Research 193, 1-10, 2014.

Shimada, K., and Stockwell, B.R. tRNA synthase suppression activates de novo cysteine synthesis to compensate for cystine and glutathione deprivation during ferroptosis. Molecular and Celleluar Oncology 5,1-2, 2016.

Stewart, Z.A., Westfall, M.D., and Pietenpol, J.A. Cell-cycle dysregulation and anticancer therapy. Trends in Pharmacological Sciences 24, 139-145, 2003.

Tanaka, T., Kimura, M., Matsunaga, K., Fukada, D., Mori, H., and Okano, Y. Centrosomal kinase AIK1 is overexpressed in invasive ductal carcinoma of the breast. Cancer Research 59, 2041-2044, 1999.

Tighe, A., Johnson, V.L., Albertella, M., and Taylor, S.S. Aneuploid colon cancer cells have a robust spindle checkpoint. European Molecular Biology Organization Reports 2, 609-614, 2001.

Vannini, A., Ringel, R., Kusser, A.G., Berninghausen, O., Kassavetis, G.A., and Cramer, P. Molecular basis of RNA polymerase III transcription repression by Maf1. Cell 143, 59-70, 2010.

Wang, J., Nikhil, K., Viccaro, K., Chang, L., Jacobsen, M., Sandusky, G., and Shah, K. The Aurora-A-Twist1 axis promotes highly aggressive phenotypes in pancreatic carcinoma. Journal of Cell Science 130, 1078-1093, 2017.

Wang, R., Wang, J.H., Chu, X.Y., Geng, H.C., and Chen, L.B. Expression of STK15 mRNA in hepatocellular carcinoma and its prognostic significance. Clinical Biochemistry 42, 641-647, 2009.

Wang, X., Li, X., Li, C., He, C., Ren, B., Deng, Q., Gao, W., and Wang, B. Aurora-A modulates MMP-2 expression via AKT/NF-κB pathway in esophageal squamous cell carcinoma cells. Acta Biochimica et Biophysica Sinica 48, 520-527, 2016.

Wang, X.X., Liu, R., Jin, S.Q., Fan, F.Y., and Zhan, Q.M. Overexpression of Aurora-A kinase promotes tumor cell proliferation and inhibits apoptosis in esophageal squamous cell carcinoma cell line. Cell Research 16, 356-366, 2006.

Wei, Y., and Zheng, X.S. Maf1 regulation: a model of signal transduction inside the nucleus. Nucleus 1, 162-165, 2010.
Wu, C., Lyu, J., Yang, E.J., Liu, Y., Zhang, B., and Shim, J.S. Targeting AURKA-CDC25C axis to induce synthetic lethality in ARID1A-deficient colorectal cancer cells. Nature Communcations 9, 3212, 2018.

Xu, H.T., Ma, L., Qi, F.J., Liu, Y., Yu, J.H., Dai, S.D., Zhu, J.J., and Wang, E.H. Expression of serine threonine kinase 15 is associated with poor differentiation in lung squamous cell carcinoma and adenocarcinoma. Pathology International 56, 375-380, 2006.

Yang, W.S., and Stockwell, B.R. Ferroptosis: Death by Lipid Peroxidation. Trends in Cell Biology 26, 165-176, 2016.

Yeh, C.N., Yen, C.C., Chen, Y.Y., Cheng, C.T., Huang, S.C., Chang, T.W., Yao, F.Y., Lin, Y.C., Wen, Y.S., Chiang, K.C., Chen, J.S., Yeh, T.S., Tzeng, C.H., Chao, T.C., and Fletcher, J.A. Identification of aurora kinase A as an unfavorable prognostic factor and potential treatment target for metastatic gastrointestinal stromal tumors. Oncotarget 5, 4071-4086, 2014.