Targeting amino acid transport in metastatic castration-resistant prostate cancer: effects on cell cycle, cell growth, and tumor development.

BACKGROUND L-type amino acid transporters (LATs) uptake neutral amino acids including L-leucine into cells, stimulating mammalian target of rapamycin complex 1 signaling and protein synthesis. LAT1 and LAT3 are overexpressed at different stages of prostate cancer, and they are responsible for increasing nutrients and stimulating cell growth. METHODS We examined LAT3 protein expression in human prostate cancer tissue microarrays. LAT function was inhibited using a leucine analog (BCH) in androgen-dependent and -independent environments, with gene expression analyzed by microarray. A PC-3 xenograft mouse model was used to study the effects of inhibiting LAT1 and LAT3 expression. Results were analyzed with the Mann-Whitney U or Fisher exact tests. All statistical tests were two-sided. RESULTS LAT3 protein was expressed at all stages of prostate cancer, with a statistically significant decrease in expression after 4-7 months of neoadjuvant hormone therapy (4-7 month mean = 1.571; 95% confidence interval = 1.155 to 1.987 vs 0 month = 2.098; 95% confidence interval = 1.962 to 2.235; P = .0187). Inhibition of LAT function led to activating transcription factor 4-mediated upregulation of amino acid transporters including ASCT1, ASCT2, and 4F2hc, all of which were also regulated via the androgen receptor. LAT inhibition suppressed M-phase cell cycle genes regulated by E2F family transcription factors including critical castration-resistant prostate cancer regulatory genes UBE2C, CDC20, and CDK1. In silico analysis of BCH-downregulated genes showed that 90.9% are statistically significantly upregulated in metastatic castration-resistant prostate cancer. Finally, LAT1 or LAT3 knockdown in xenografts inhibited tumor growth, cell cycle progression, and spontaneous metastasis in vivo. CONCLUSION Inhibition of LAT transporters may provide a novel therapeutic target in metastatic castration-resistant prostate cancer, via suppression of mammalian target of rapamycin complex 1 activity and M-phase cell cycle genes.

[1]  Linda V. Sinclair,et al.  Control of amino-acid transport by antigen receptors coordinates the metabolic reprogramming essential for T cell differentiation , 2013, Nature Immunology.

[2]  D. Angelov,et al.  Direct cooperation between androgen receptor and E2F1 reveals a common regulation mechanism for androgen-responsive genes in prostate cells. , 2012, Molecular endocrinology.

[3]  Nicholas T. Ingolia,et al.  The translational landscape of mTOR signalling steers cancer initiation and metastasis , 2012, Nature.

[4]  J. Shan,et al.  The transcription factor network associated with the amino acid response in mammalian cells. , 2012, Advances in nutrition.

[5]  B. Dynlacht,et al.  Regulation of a Novel Androgen Receptor Target Gene, the Cyclin B1 Gene, through Androgen-Dependent E2F Family Member Switching , 2012, Molecular and Cellular Biology.

[6]  C. De Virgilio,et al.  Leucyl-tRNA synthetase controls TORC1 via the EGO complex. , 2012, Molecular cell.

[7]  Sunghoon Kim,et al.  Leucyl-tRNA Synthetase Is an Intracellular Leucine Sensor for the mTORC1-Signaling Pathway , 2012, Cell.

[8]  Benjamin J. Raphael,et al.  The Mutational Landscape of Lethal Castrate Resistant Prostate Cancer , 2016 .

[9]  Qian Wang,et al.  Androgen receptor and nutrient signaling pathways coordinate the demand for increased amino acid transport during prostate cancer progression. , 2011, Cancer research.

[10]  E. Dudenhausen,et al.  Auto-activation of c-JUN Gene by Amino Acid Deprivation of Hepatocellular Carcinoma Cells Reveals a Novel c-JUN-mediated Signaling Pathway* , 2011, The Journal of Biological Chemistry.

[11]  Qianben Wang,et al.  CCI-779 inhibits cell-cycle G2-M progression and invasion of castration-resistant prostate cancer via attenuation of UBE2C transcription and mRNA stability. , 2011, Cancer research.

[12]  Qianben Wang,et al.  Phospho‐MED1‐enhanced UBE2C locus looping drives castration‐resistant prostate cancer growth , 2011, The EMBO journal.

[13]  D. Sabatini,et al.  Defective regulation of autophagy upon leucine deprivation reveals a targetable liability of human melanoma cells in vitro and in vivo. , 2011, Cancer cell.

[14]  H. Weiss,et al.  mTORC1 and mTORC2 regulate EMT, motility, and metastasis of colorectal cancer via RhoA and Rac1 signaling pathways. , 2011, Cancer research.

[15]  Rajvir Dahiya,et al.  Regulatory Role of mir-203 in Prostate Cancer Progression and Metastasis , 2010, Clinical Cancer Research.

[16]  Cynthia Ng,et al.  Luciferase expression and bioluminescence does not affect tumor cell growth in vitro or in vivo , 2010, Molecular Cancer.

[17]  C. Sander,et al.  Integrative genomic profiling of human prostate cancer. , 2010, Cancer cell.

[18]  L. Fajas,et al.  Metabolism and proliferation share common regulatory pathways in cancer cells , 2010, Oncogene.

[19]  H. Baker,et al.  Expression profiling after activation of amino acid deprivation response in HepG2 human hepatoma cells. , 2010, Physiological genomics.

[20]  D. Sabatini,et al.  Ragulator-Rag Complex Targets mTORC1 to the Lysosomal Surface and Is Necessary for Its Activation by Amino Acids , 2010, Cell.

[21]  L. Languino,et al.  IAP regulation of metastasis. , 2010, Cancer cell.

[22]  M. Rapé,et al.  Building ubiquitin chains: E2 enzymes at work , 2009, Nature Reviews Molecular Cell Biology.

[23]  M. Karsy,et al.  Involvement of mTORC1 and mTORC2 in regulation of glioblastoma multiforme growth and motility. , 2009, International journal of oncology.

[24]  P. Kaldis,et al.  Mammalian cell-cycle regulation: several Cdks, numerous cyclins and diverse compensatory mechanisms , 2009, Oncogene.

[25]  Clifford A. Meyer,et al.  Androgen Receptor Regulates a Distinct Transcription Program in Androgen-Independent Prostate Cancer , 2009, Cell.

[26]  M. Barbacid,et al.  Cell cycle, CDKs and cancer: a changing paradigm , 2009, Nature Reviews Cancer.

[27]  Madhuchhanda Bhattacharjee,et al.  Conserved gene expression programs integrate mammalian prostate development and tumorigenesis. , 2009, Cancer research.

[28]  Y. Kanai,et al.  L‐type amino‐acid transporter 1 as a novel biomarker for high‐grade malignancy in prostate cancer , 2009, Pathology international.

[29]  N. Sunaga,et al.  l‐type amino acid transporter 1 and CD98 expression in primary and metastatic sites of human neoplasms , 2008, Cancer science.

[30]  Alain C. Mita,et al.  Survivin: Key Regulator of Mitosis and Apoptosis and Novel Target for Cancer Therapeutics , 2008, Clinical Cancer Research.

[31]  T. Golub,et al.  Estrogen-dependent signaling in a molecularly distinct subclass of aggressive prostate cancer. , 2008, Journal of the National Cancer Institute.

[32]  Y. Kanai,et al.  BCH, an inhibitor of system L amino acid transporters, induces apoptosis in cancer cells. , 2008, Biological & pharmaceutical bulletin.

[33]  Y. Asmann,et al.  A Tissue Biomarker Panel Predicting Systemic Progression after PSA Recurrence Post-Definitive Prostate Cancer Therapy , 2008, PloS one.

[34]  Hongtao Yu,et al.  Cdc20: a WD40 activator for a cell cycle degradation machine. , 2007, Molecular cell.

[35]  M. Kirschner,et al.  Ubiquitination by the anaphase-promoting complex drives spindle checkpoint inactivation , 2007, Nature.

[36]  F. Bessho,et al.  Protein characterization of NA+-independent system L amino acid transporter 3 in mice: a potential role in supply of branched-chain amino acids under nutrient starvation. , 2007, The American journal of pathology.

[37]  M. Becich,et al.  Gene expression profiles of prostate cancer reveal involvement of multiple molecular pathways in the metastatic process , 2007, BMC Cancer.

[38]  John T. Wei,et al.  Integrative genomic and proteomic analysis of prostate cancer reveals signatures of metastatic progression. , 2005, Cancer cell.

[39]  B. Fuchs,et al.  Amino acid transporters ASCT2 and LAT1 in cancer: partners in crime? , 2005, Seminars in cancer biology.

[40]  M. Palacín,et al.  Identification of LAT4, a Novel Amino Acid Transporter with System L Activity* , 2005, Journal of Biological Chemistry.

[41]  M. Becich,et al.  Gene expression alterations in prostate cancer predicting tumor aggression and preceding development of malignancy. , 2004, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[42]  E. Babu,et al.  Identification of a Novel System L Amino Acid Transporter Structurally Distinct from Heterodimeric Amino Acid Transporters* , 2003, Journal of Biological Chemistry.

[43]  J. Cheville,et al.  Transcriptional silencing of zinc finger protein 185 identified by expression profiling is associated with prostate cancer progression. , 2003, Cancer research.

[44]  R. Paules,et al.  An integrated stress response regulates amino acid metabolism and resistance to oxidative stress. , 2003, Molecular cell.

[45]  E. Latulippe,et al.  Comprehensive gene expression analysis of prostate cancer reveals distinct transcriptional programs associated with metastatic disease. , 2002, Cancer research.

[46]  D. Copenhagen,et al.  Coupled and uncoupled proton movement by amino acid transport system N , 2001, The EMBO journal.

[47]  L. Kühn,et al.  LAT2, a New Basolateral 4F2hc/CD98-associated Amino Acid Transporter of Kidney and Intestine* , 1999, The Journal of Biological Chemistry.

[48]  C. Shoemaker,et al.  Amino-acid transport by heterodimers of 4F2hc/CD98 and members of a permease family , 1998, Nature.

[49]  Eiji Takeda,et al.  Expression Cloning and Characterization of a Transporter for Large Neutral Amino Acids Activated by the Heavy Chain of 4F2 Antigen (CD98)* , 1998, The Journal of Biological Chemistry.

[50]  L. Liotta,et al.  cDNA sequencing and analysis of POV1 (PB39): a novel gene up-regulated in prostate cancer. , 1998, Genomics.

[51]  J. Ramos,et al.  Complementation of dominant suppression implicates CD98 in integrin activation , 1997, Nature.

[52]  L. Liotta,et al.  Identification of a novel transcript up-regulated in a clinically aggressive prostate carcinoma. , 1997, Urology.

[53]  Harold Weintraub,et al.  The protein Id: A negative regulator of helix-loop-helix DNA binding proteins , 1990, Cell.