1
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Rosario FJ, Urschitz J, Powell TL, Brown TL, Jansson T. Overexpression of the LAT1 in primary human trophoblast cells increases the uptake of essential amino acids and activates mTOR signaling. Clin Sci (Lond) 2023; 137:1651-1664. [PMID: 37861075 DOI: 10.1042/cs20230490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 10/21/2023]
Abstract
The System L amino acid transporter, particularly the isoform Large Neutral Amino Acid Transporter Small Subunit 1 (LAT1) encoded by SLC7A5, is believed to mediate the transfer of essential amino acids in the human placenta. Placental System L amino acid transporter expression and activity is decreased in pregnancies complicated by IUGR and increased in fetal overgrowth. However, it remains unknown if changes in the expression of LAT1 are mechanistically linked to System L amino acid transport activity. Here, we combined overexpression approaches with protein analysis and functional studies in cultured primary human trophoblast (PHT) cells to test the hypothesis that SLC7A5 overexpression increases the uptake of essential amino acids and activates mTOR signaling in PHT cells. Overexpression of SLC7A5 resulted in a marked increase in protein expression of LAT1 in the PHT cells microvillous plasma membrane and System L amino acid transporter activity. Moreover, mTOR signaling was activated, and System A amino acid transporter activity increased following SLC7A5 overexpression, suggesting coordination of trophoblast amino transporter expression and activity to ensure balanced nutrient flux to the fetus. This is the first report showing that overexpression of LAT1 is sufficient to increase the uptake of essential amino acids in PHT cells, which activates mTOR, a master regulator of placental function. The decreased placental System L activity in human IUGR and the increased placental activity of this transporter system in some cases of fetal overgrowth may directly contribute to changes in fetal amino acid availability and altered fetal growth in these pregnancy complications.
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Affiliation(s)
- Fredrick J Rosario
- Department of Obstetrics and Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, CO, U.S.A
| | - Johann Urschitz
- Institute for Biogenesis Research, University of Hawaii, Honolulu, HI, U.S.A
| | - Theresa L Powell
- Department of Obstetrics and Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, CO, U.S.A
- Institute for Biogenesis Research, University of Hawaii, Honolulu, HI, U.S.A
| | - Thomas L Brown
- Section of Neonatology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, U.S.A
- Department of Neuroscience, Cell Biology, and Physiology, Wright State University Boonshoft School of Medicine, Dayton, OH, U.S.A
| | - Thomas Jansson
- Department of Obstetrics and Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, CO, U.S.A
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2
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Choi DW, Kim DK, Kanai Y, Wempe MF, Endou H, Kim JK. JPH203, a selective L-type amino acid transporter 1 inhibitor, induces mitochondria-dependent apoptosis in Saos2 human osteosarcoma cells. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2017; 21:599-607. [PMID: 29200902 PMCID: PMC5709476 DOI: 10.4196/kjpp.2017.21.6.599] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 08/11/2017] [Accepted: 09/08/2017] [Indexed: 11/30/2022]
Abstract
Most normal cells express L-type amino acid transporter 2 (LAT2). However, L-type amino acid transporter 1 (LAT1) is highly expressed in many tumor cells and presumed to support their increased growth and proliferation. This study examined the effects of JPH203, a selective LAT1 inhibitor, on cell growth and its mechanism for cell death in Saos2 human osteosarcoma cells. FOB human osteoblastic cells and Saos2 cells expressed LAT1 and LAT2 together with their associating protein 4F2 heavy chain, but the expression of LAT2 in the Saos2 cells was especially weak. JPH203 and BCH, a non-selective L-type amino acid transporter inhibitor, potently inhibited L-leucine uptake in Saos2 cells. As expected, the intrinsic ability of JPH203 to inhibit L-leucine uptake was far more efficient than that of BCH in Saos2 cells. Likewise, JPH203 and BCH inhibited Saos2 cell growth with JPH203 being superior to BCH in this regard. Furthermore, JPH203 increased apoptosis rates and formed DNA ladder in Saos2 cells. Moreover, JPH203 activated the mitochondria-dependent apoptotic signaling pathway by upregulating pro-apoptotic factors, such as Bad, Bax, and Bak, and the active form of caspase-9, and downregulating anti-apoptotic factors, such as Bcl-2 and Bcl-xL. These results suggest that the inhibition of LAT1 activity via JPH203, which may act as a potential novel anti-cancer agent, leads to apoptosis mediated by the mitochondria-dependent intrinsic apoptotic signaling pathway by inducing the intracellular depletion of neutral amino acids essential for cell growth in Saos2 human osteosarcoma cells.
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Affiliation(s)
- Dae Woo Choi
- Department of Pharmacology, Chonnam National University Medical School, Gwangju 61469, Korea
| | - Do Kyung Kim
- Department of Oral Physiology, Chosun University School of Dentistry, Gwangju 61452, Korea
| | - Yoshikatsu Kanai
- Department of Bio-system Pharmacology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Michael F Wempe
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Hitoshi Endou
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo 181-8611, Japan.,J-Pharma Co., Ltd., Yokohama, Kanagawa 230-0046, Japan
| | - Jong-Keun Kim
- Department of Pharmacology, Chonnam National University Medical School, Gwangju 61469, Korea
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3
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Kume E, Mutou T, Kansaku N, Takahashi H, Wempe MF, Ikegami M, Kanai Y, Endou H, Wakui S. Ultrastructural immunohistochemical study of L-type amino acid transporter 1-4F2 heavy chain in tumor microvasculatures of N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) induced rat bladder carcinoma. Microscopy (Oxf) 2017; 66:198-203. [PMID: 28339760 DOI: 10.1093/jmicro/dfx008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 02/15/2017] [Indexed: 06/06/2023] Open
Abstract
Angiogenesis is essential for tumor growth, and an enhanced vasculature supplying nutrients and oxygen might reflect malignant potential. L-type amino acid transporter 1 (LAT1/4F2hc) comprises a major nutrient transport system responsible for the Na+-independent transport of large neutral amino acids. Seventy five to seventy eight percent N-butyl-N-(4-hydroxybutyl) nitrosamine-induced rat bladder carcinoma cells showed high LAT1/4F2hc expression. While the intracarcinoma microvasculatures of fenestrated endothelial cells highly expressing LAT1/4F2hc might progressively transport essential amino acids from the microvasculatures to the extracellular matrix, non-fenestrated endothelial cells and pericytes did not. The present study revealed that the tumor angiogenesis is one of target anti-L-type amino acid transporter 1 drug.
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Affiliation(s)
- Eisuke Kume
- Azabu University School of Veterinary Medicine, Kanagawa, Japan
| | | | - Norio Kansaku
- Azabu University School of Veterinary Medicine, Kanagawa, Japan
| | - Hitoyuki Takahashi
- Department of Pathology, The Jikei University School of Medicine, Tokyo, Japan
| | - Michael F Wempe
- School of Pharmacy, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Masahiro Ikegami
- Department of Pathology, The Jikei University School of Medicine, Tokyo, Japan
| | - Yoshikatsu Kanai
- Department of Pharmacology, Osaka University Graduate School of Medicine, Osaka, Japan, and
| | | | - Shin Wakui
- Azabu University School of Veterinary Medicine, Kanagawa, Japan
- Department of Pathology, The Jikei University School of Medicine, Tokyo, Japan
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4
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Hirano K, Uno K, Kuwabara H, Kojima K, Ohno SI, Sakurai H, Kamma H, Kurata A. Expression of L-type amino acid transporter 1 in various skin lesions. Pathol Res Pract 2014; 210:634-9. [DOI: 10.1016/j.prp.2014.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 05/01/2014] [Accepted: 05/05/2014] [Indexed: 01/06/2023]
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5
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Yun DW, Lee SA, Park MG, Kim JS, Yu SK, Park MR, Kim SG, Oh JS, Kim CS, Kim HJ, Kim JS, Chun HS, Kanai Y, Endou H, Wempe MF, Kim DK. JPH203, an L-type amino acid transporter 1-selective compound, induces apoptosis of YD-38 human oral cancer cells. J Pharmacol Sci 2014; 124:208-17. [PMID: 24492461 DOI: 10.1254/jphs.13154fp] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Compared to most normal cells that express L-type amino acid transporter 2, L-type amino acid transporter 1 is highly expressed in cancer cells and presumed to support their elevated growth and proliferation. This study examined JPH203, a potent and selective L-type amino acid transporter 1 inhibitor, and its ability to suppress YD-38 human oral cancer cell growth. The YD-38 cells express L-type amino acid transporter 1 with its associating protein 4F2 heavy chain, but not L-type amino acid transporter 2. JPH203 and BCH, a non-selective L-type amino acid transporter inhibitor, completely inhibited l-leucine uptake in YD-38 cells. As expected, the intrinsic affinity of JPH203 to inhibit l-leucine uptake was far more efficient than BCH. Likewise, JPH203 and BCH inhibited YD-38 cell growth, with JPH203 being superior to BCH. JPH203 up-regulated the population of apoptotic YD-38 cells through the activation of apoptotic factors, including caspases and PARP. These results suggest that the inhibition of L-type amino acid transporter 1 activity via JPH203, which may act as a potential novel anti-oral-cancer agent, leads to apoptosis by inducing the intracellular depletion of the neutral amino acids essential for cancer cell growth in YD-38 human oral cancer cells.
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Affiliation(s)
- Dae-Woong Yun
- Oral Biology Research Institute, Chosun University School of Dentistry, Korea
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6
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Fukumoto S, Hanazono K, Komatsu T, Ueno H, Kadosawa T, Iwano H, Uchide T. L-type amino acid transporter 1 (LAT1): A new therapeutic target for canine mammary gland tumour. Vet J 2013; 198:164-9. [DOI: 10.1016/j.tvjl.2013.06.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 06/21/2013] [Accepted: 06/25/2013] [Indexed: 10/26/2022]
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7
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Schiöth HB, Roshanbin S, Hägglund MGA, Fredriksson R. Evolutionary origin of amino acid transporter families SLC32, SLC36 and SLC38 and physiological, pathological and therapeutic aspects. Mol Aspects Med 2013; 34:571-85. [PMID: 23506890 DOI: 10.1016/j.mam.2012.07.012] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 06/25/2012] [Indexed: 10/27/2022]
Abstract
About 25% of all solute carriers (SLCs) are likely to transport amino acids as their primary substrate. One of the major phylogenetic clusters of amino acid transporters from the SLC family is the β-family, which is part of the PFAM APC clan. The β-family includes three SLC families, SLC32, SLC36 and SLC38 with one, four and eleven members in humans, respectively. The most well characterized genes within these families are the vesicular inhibitory amino acid transporter (VIAAT, SLC32A1), PAT1 (SLC36A1), PAT2 (SLC36A2), PAT4 (SLC36A4), SNAT1 (SLC38A1), SNAT2 (SLC38A2), SNAT3 (SLC38A3), and SNAT4 (SLC38A4). Here we review the structural characteristics and functional role of these transporters. We also mined the complete protein sequence datasets for nine different genomes to clarify the evolutionary history of the β-family of transporters. We show that all three main branches of the this family are found as far back as green algae suggesting that genes from these families existed in the early eukaryote before the split of animals and plants and that they are present in most animal species. We also address the potential of further drug development within this field highlighting the important role of these transporters in neurotransmission and transport of amino acids as nutrients.
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Affiliation(s)
- Helgi B Schiöth
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden.
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8
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Fukumoto S, Hanazono K, Fu DR, Endo Y, Kadosawa T, Iwano H, Uchide T. A new treatment for human malignant melanoma targeting L-type amino acid transporter 1 (LAT1): A pilot study in a canine model. Biochem Biophys Res Commun 2013; 439:103-8. [DOI: 10.1016/j.bbrc.2013.08.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 08/07/2013] [Indexed: 11/16/2022]
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Deng K, Lin S, Zhou L, Li Y, Chen M, Wang Y, Li Y. High levels of aromatic amino acids in gastric juice during the early stages of gastric cancer progression. PLoS One 2012; 7:e49434. [PMID: 23152906 PMCID: PMC3496670 DOI: 10.1371/journal.pone.0049434] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 10/07/2012] [Indexed: 01/19/2023] Open
Abstract
Background Early-stage gastric cancer is mostly asymptomatic and can easily be missed easily by conventional gastroscopy. Currently, there are no useful biomarkers for the early detection of gastric cancer, and their identification of biomarkers is urgently needed. Methods Gastric juice was obtained from 185 subjects that were divided into three groups: non-neoplastic gastric disease (NGD), advanced gastric cancer and early gastric cancer (EGC). The levels of aromatic amino acids in the gastric juice were quantitated using high-performance liquid chromatography. Results The median values (25th to 75th percentile) of tyrosine, phenylalanine and tryptophan in the gastric juice were 3.8 (1.7–7.5) µg/ml, 5.3 (2.3–9.9) µg/ml and 1.0 (0.4–2.8) µg/ml in NGD; 19.4 (5.8–72.4) µg/ml, 24.6 (11.5–73.7) µg/ml and 8.3 (2.1–28.0) µg/ml in EGC. Higher levels of tyrosine, phenylalanine and tryptophan in the gastric juice were observed in individuals of EGC groups compared those of the NGD group (NGD vs. EGC, P<0.0001). For the detection of EGC, the areas under the receiver operating characteristic curves (AUCs) of each biomarker were as follows: tyrosine, 0.790 [95% confidence interval (CI), 0.703–0.877]; phenylalanine, 0.831 (95% CI, 0.750–0.911); and tryptophan, 0.819 (95% CI, 0.739–0.900). The sensitivity and specificity of phenylalanine were 75.5% and 81.4%, respectively, for detection of EGC. A multiple logistic regression analysis showed that high levels of aromatic amino acids in the gastric juice were associated with gastric cancer (adjusted β coefficients ranged from 1.801 to 4.414, P<0.001). Conclusion Increased levels of tyrosine, phenylalanine and tryptophan in the gastric juice samples were detected in the early phase of gastric carcinogenesis. Thus, tyrosine, phenylalanine and tryptophan in gastric juice could be used as biomarkers for the early detection of gastric cancer. A gastric juice analysis is an efficient, economical and convenient method for screening early gastric cancer development in the general population.
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Affiliation(s)
- Kai Deng
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Sanren Lin
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Liya Zhou
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
- * E-mail:
| | - Yuan Li
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Mo Chen
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Yingchun Wang
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Yuwen Li
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
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10
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Uno K, Kuwabara H, Terado Y, Kojima K, Kawakami T, Kamma H, Sakurai H, Sakamoto A, Kurata A. Divergent expression of L-type amino acid transporter 1 during uterine cervical carcinogenesis. Hum Pathol 2011; 42:1660-6. [DOI: 10.1016/j.humpath.2011.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 12/27/2010] [Accepted: 01/04/2011] [Indexed: 10/18/2022]
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11
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Liang Z, Cho HT, Williams L, Zhu A, Liang K, Huang K, Wu H, Jiang C, Hong S, Crowe R, Goodman MM, Shim H. Potential Biomarker of L-type Amino Acid Transporter 1 in Breast Cancer Progression. Nucl Med Mol Imaging 2010; 45:93-102. [PMID: 24899987 DOI: 10.1007/s13139-010-0068-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 11/04/2010] [Indexed: 12/16/2022] Open
Abstract
PURPOSE L-type amino acid transporter 1 (LAT1) is essential for the transport of large neutral amino acids. However, its role in breast cancer growth remains largely unknown. The purpose of the study is to investigate whether LAT1 is a potential biomarker for the diagnosis and treatment of breast cancer. METHODS LAT1 mRNA and protein levels in breast cancer cell lines and tissues were analyzed. In addition, the effects of targeting LAT1 for the inhibition of breast cancer cell tumorigenesis were assessed with soft agar assay. The imaging of xenograft with anti-1-amino-3-[(18)F]fluorocyclobutane-1-carboxylic acid (anti-[(18)F]FACBC) PET was assessed for its diagnostic biomarker potential. RESULTS Normal breast tissue or low malignant cell lines expressed low levels of LAT1 mRNA and protein, while highly malignant cancer cell lines and high-grade breast cancer tissue expressed high levels of LAT1. In addition, higher expression levels of LAT1 in breast cancer tissues were consistent with advanced-stage breast cancer. Furthermore, the blockade of LAT1 with its inhibitor, 2-amino-bicyclo[2.2.1]heptane-2-carboxylic acid (BCH), or the knockdown of LAT1 with siRNA, inhibited proliferation and tumorigenesis of breast cancer cells. A leucine analog, anti-[(18)F]FACBC, has been demonstrated to be an excellent PET tracer for the non-invasive imaging of malignant breast cancer using an orthotopic animal model. CONCLUSIONS The overexpression of LAT1 is required for the progression of breast cancer. LAT1 represents a potential biomarker for therapy and diagnosis of breast cancer. Anti-[(18)F]FACBC that correlates with LAT1 function is a potential PET tracer for malignant breast tumor imaging.
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Affiliation(s)
- Zhongxing Liang
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA ; Winship Cancer Institute, Emory University School of Medicine, Atlanta, USA
| | - Heidi T Cho
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA
| | - Larry Williams
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA
| | - Aizhi Zhu
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA
| | - Ke Liang
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA
| | - Ke Huang
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA
| | - Hui Wu
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA
| | - Chunsu Jiang
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA
| | - Samuel Hong
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA
| | - Ronald Crowe
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA
| | - Mark M Goodman
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA ; Winship Cancer Institute, Emory University School of Medicine, Atlanta, USA
| | - Hyunsuk Shim
- Department of Radiology, Emory University School of Medicine, 1365C Clifton Road NE, Atlanta, GA 30322 USA ; Winship Cancer Institute, Emory University School of Medicine, Atlanta, USA
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12
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Fan X, Ross DD, Arakawa H, Ganapathy V, Tamai I, Nakanishi T. Impact of system L amino acid transporter 1 (LAT1) on proliferation of human ovarian cancer cells: a possible target for combination therapy with anti-proliferative aminopeptidase inhibitors. Biochem Pharmacol 2010; 80:811-8. [PMID: 20510678 DOI: 10.1016/j.bcp.2010.05.021] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2010] [Revised: 05/15/2010] [Accepted: 05/18/2010] [Indexed: 02/06/2023]
Abstract
Amino acids activate nutrient signaling via the mammalian target of rapamycin (mTOR), we therefore evaluated the relationship between amino acid transporter gene expression and proliferation in human ovarian cancer cell lines. Expression of three cancer-associated amino acid transporter genes, LAT1, ASCT2 and SN2, was measured by qRT-PCR and Western blot. The effects of silencing the LAT1 gene and its inhibitor BCH on cell growth were evaluated by means of cell proliferation and colony formation assays. The system L amino acid transporter LAT1 was up-regulated in human ovarian cancer SKOV3, IGROV1, A2780, and OVCAR3 cells, compared to normal ovarian epithelial IOSE397 cells, whereas ASCT2 and SN2 were not. BCH reduced phosphorylation of p70S6K, a down-stream effector of mTOR, in SKOV3 and IGROV1 cells, and decreased their proliferation by 30% and 28%, respectively. Although proliferation of SKOV3 (S1) or IGROV1 (I10) cells was unaffected by LAT1-knockdown, plating efficiency in colony formation assays was significantly reduced in SKOV3(S1) and IGROV1(I10) cells to 21% and 52% of the respective plasmid transfected control cells, SKOV3(SC) and IGROV(IC), suggesting that LAT1 affects anchorage-independent cell proliferation. Finally, BCH caused 10.5- and 4.3-fold decrease in the IC(50) value of bestatin, an anti-proliferative aminopeptidase inhibitor, in IGROV1 and A2780 cells, respectively, suggesting that the combined therapy is synergistic. Our findings indicate that LAT1 expression is increased in human ovarian cancer cell lines; LAT1 may be a target for combination therapy with anti-proliferative aminopeptidase inhibitors to combat ovarian cancer.
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Affiliation(s)
- Xuetao Fan
- The Program in Experimental Therapeutics, Marlene and Stewart Greenebaum Cancer Center, Departments of Medicine, Pathology and Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore, MD, USA
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13
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Rendic S, Guengerich FP. Update information on drug metabolism systems--2009, part II: summary of information on the effects of diseases and environmental factors on human cytochrome P450 (CYP) enzymes and transporters. Curr Drug Metab 2010; 11:4-84. [PMID: 20302566 PMCID: PMC4167379 DOI: 10.2174/138920010791110917] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 02/22/2010] [Indexed: 12/14/2022]
Abstract
The present paper is an update of the data on the effects of diseases and environmental factors on the expression and/or activity of human cytochrome P450 (CYP) enzymes and transporters. The data are presented in tabular form (Tables 1 and 2) and are a continuation of previously published summaries on the effects of drugs and other chemicals on CYP enzymes (Rendic, S.; Di Carlo, F. Drug Metab. Rev., 1997, 29(1-2), 413-580., Rendic, S. Drug Metab. Rev., 2002, 34(1-2), 83-448.). The collected information presented here is as stated by the cited author(s), and in cases when several references are cited the latest published information is included. Inconsistent results and conclusions obtained by different authors are highlighted, followed by discussion of the major findings. The searchable database is available as an Excel file, for information about file availability contact the corresponding author.
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Affiliation(s)
- S Rendic
- University of Zagreb, Zagreb, Croatia.
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14
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System L amino acid transporter inhibitor enhances anti-tumor activity of cisplatin in a head and neck squamous cell carcinoma cell line. Cancer Lett 2008; 276:95-101. [PMID: 19058911 DOI: 10.1016/j.canlet.2008.10.035] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 10/26/2008] [Accepted: 10/27/2008] [Indexed: 11/22/2022]
Abstract
LAT1, a subunit of heterodimeric system L transporter responsible for transporting neutral amino acids into cells, has been investigated in several cancers because of its onco-fetal nature. Based on the studies of its functional inhibition, LAT1 has been proposed to be a new molecular target of a cancer therapy. We have shown here that human head and neck cancer cell line, Hep-2, expresses both LAT1 and 4F2hc, another subunit of system L transporter. An inhibitor of system L, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH), inhibited leucine uptake by the cells. BCH administration or restriction of essential amino acid leucine decreased viability of Hep-2 cells. Co-administration of cisplatin with BCH reduced the viability of the cells more than either agent alone. When BCH treatment preceded cisplatin administration, reduction in Hep-2 cell viability was additive. In contrast, when BCH was given after cisplatin treatment, synergistic effect in decreasing the number of viable cells was obtained. BCH treatment decreased the phosphorylation of mTOR, p70S6K and 4EBP1, suggesting that BCH enhanced anti-tumor action of cisplatin by inhibiting mTOR pathway. This potentiation may be used to reduce cisplatin exposure to alleviate many unwanted toxicity of the drug.
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15
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Kim CS, Cho SH, Chun HS, Lee SY, Endou H, Kanai Y, Kim DK. BCH, an Inhibitor of System L Amino Acid Transporters, Induces Apoptosis in Cancer Cells. Biol Pharm Bull 2008; 31:1096-100. [DOI: 10.1248/bpb.31.1096] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Chun Sung Kim
- Department of Oral Physiology and The Second Stage of BK21, Chosun University College of Dentistry
| | - Seon-Ho Cho
- Department of Oral Physiology and The Second Stage of BK21, Chosun University College of Dentistry
| | - Hong Sung Chun
- Department of Biotechnology (BK21 Program), Chosun University
- Research Center for Proteineous Materials, Chosun University
| | - Sook-Young Lee
- Research Center for Proteineous Materials, Chosun University
| | - Hitoshi Endou
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine
| | - Yoshikatsu Kanai
- Department of Pharmacology, Osaka University Graduate School of Medicine
| | - Do Kyung Kim
- Department of Oral Physiology and The Second Stage of BK21, Chosun University College of Dentistry
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Nakanishi K, Ogata S, Matsuo H, Kanai Y, Endou H, Hiroi S, Tominaga S, Aida S, Kasamatsu H, Kawai T. Expression of LAT1 predicts risk of progression of transitional cell carcinoma of the upper urinary tract. Virchows Arch 2007; 451:681-90. [PMID: 17622555 DOI: 10.1007/s00428-007-0457-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 05/20/2007] [Accepted: 06/15/2007] [Indexed: 12/18/2022]
Abstract
L-type amino acid transporter 1 (LAT1), a neutral amino acid transporter, requires covalent association with the heavy chain of 4F2 cell surface antigen (4F2hc) for its functional form. We investigated the importance of LAT1 and 4F2hc expressions to progression in upper urinary tract cancer. We examined their expressions and their relationships to clinicopathologic parameters and clinical outcome in 124 cases. Positive expressions of LAT1 (protein and messenger ribonucleic acid) and 4F2hc (protein) were recognized in 79.8, 89.5, and 87.9% of tumor samples, respectively. In tumor cells, LAT1 protein was detected either as nodular granules within the cytoplasm or diffusely within the cytoplasm and/or on plasma membrane. In the normal urothelium, its expression was detected as nodular granules within the cytoplasm. A correlation with stage was shown for LAT1 protein expression and for a cooperative expression of LAT1 protein with 4F2hc protein (active form of LAT1 protein). Further, in all tumors, a cooperative expression of LAT1 protein and 4F2hc protein was significantly correlated with both overall and disease-free survival rates in the univariate analysis but not in the multivariate analysis. In conclusion, the detection of the active form of LAT1 protein would appear to be of value in informing the risk of progression in transitional cell carcinoma of the upper urinary tract.
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Affiliation(s)
- Kuniaki Nakanishi
- Department of Pathology and Laboratory Medicine, National Defense Medical College, Tokorozawa, 359-8513, Japan.
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17
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Storey BT, Fugere C, Lesieur-Brooks A, Vaslet C, Thompson NL. Adenoviral modulation of the tumor-associated system L amino acid transporter, LAT1, alters amino acid transport, cell growth and 4F2/CD98 expressionwith cell-type specific effects in cultured hepatic cells. Int J Cancer 2005; 117:387-97. [PMID: 15900591 DOI: 10.1002/ijc.21169] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Altered expression of metabolite transporters is observed frequently in tumor cell lines and primary neoplasms. The extent to which these may to contribute to the growth autonomy associated with cancer is not clear. LAT1 is a major L-type amino acid transporter over-expressed in a variety of cancer types and a light chain component of the CD98 heterodimer. We utilized an adenoviral expression system to modulate the level of LAT1 in a hepatic in vitro model to examine phenotypic changes associated with short-term exogenous and blocked expression. LAT1 levels were increased three fold and resulted in increased L-type amino acid transport as a result of adenoviral expression in murine hepatocytes. The protein was expressed on the cell surface and complexed with the CD98 heavy chain known as 4F2. Surprisingly, levels of the total CD98 protein complex were increased 2.4-fold as a result of adenoviral expression of light chain only, suggesting coordinate regulation. Exogenous overexpression was less effective in normal rat liver cells relative to mouse. LAT1 antisense expression in hepatic tumor cells resulted in a modest though statistically significant decrease in cell number, viability and S-phase cells over a 5-day period relative to controls despite the absence of a significant decrease in L-type transport over this period. These studies are preparatory to in vivo efforts focusing on LAT1/CD98 as a potential therapeutic target.
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Affiliation(s)
- Bill T Storey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
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18
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Abstract
Relative to other neutral amino acid transporters, the expression levels of ASCT2 and LAT1, are coordinately elevated in a wide spectrum of primary human cancers, suggesting that they are frequently co-opted to support the "tumor metabolome". Each has recently been shown to play important roles in the growth and survival of cancer cell lines, making them potential targets for cancer therapy. The properties and putative relationship of these two amino acid exchangers are discussed in the context of their demonstrated utility in cancer biology, including cellular growth and survival signaling and integrated links to the mammalian target-of-rapamycin (mTOR) kinase.
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Affiliation(s)
- Bryan C Fuchs
- Department of Biology, Saint Louis University, MW128, 3507 Laclede Avenue, St. Louis, MO 63103-2010, USA
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19
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Park SY, Kim JK, Kim IJ, Choi BK, Jung KY, Lee S, Park KJ, Chairoungdua A, Kanai Y, Endou H, Kim DK. Reabsorption of neutral amino acids mediated by amino acid transporter LAT2 and TAT1 in the basolateral membrane of proximal tubule. Arch Pharm Res 2005; 28:421-32. [PMID: 15918515 DOI: 10.1007/bf02977671] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
In order to understand the renal reabsorption mechanism of neutral amino acids via amino acid transporters, we have isolated human L-type amino acid transporter 2 (hLAT2) and human T-type amino acid transporter 1 (hTAT1) in human, then, we have examined and compared the gene structures, the functional characterizations and the localization in human kidney. Northern blot analysis showed that hLAT2 mRNA was expressed at high levels in the heart, brain, placenta, kidney, spleen, prostate, testis, ovary, lymph node and the fetal liver. The hTAT1 mRNA was detected at high levels in the heart, placenta, liver, skeletal muscle, kidney, pancreas, spleen, thymus and prostate. Immunohistochemical analysis on the human kidney revealed that the hLAT2 and hTAT1 proteins coexist in the basolateral membrane of the renal proximal tubules. The hLAT2 transports all neutral amino acids and hTAT1 transports aromatic amino acids. The basolateral location of the hLAT2 and hTAT1 proteins in the renal proximal tubule as well as the amino acid transport activity of hLAT2 and hTAT1 suggests that these transporters contribute to the renal reabsorption of neutral and aromatic amino acids in the basolateral domain of epithelial proximal tubule cells, respectively. Therefore, LAT2 and TAT1 play essential roles in the reabsorption of neutral amino acids from the epithelial cells to the blood stream in the kidney. Because LAT2 and TAT1 are essential to the efficient absorption of neutral amino acids from the kidney, their defects might be involved in the pathogenesis of disorders caused by a disruption in amino acid absorption such as blue diaper syndrome.
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MESH Headings
- Absorption
- Amino Acid Sequence
- Amino Acid Transport System y+/biosynthesis
- Amino Acid Transport System y+/chemistry
- Amino Acid Transport System y+/genetics
- Amino Acid Transport Systems, Neutral/biosynthesis
- Amino Acid Transport Systems, Neutral/chemistry
- Amino Acid Transport Systems, Neutral/genetics
- Amino Acids, Neutral/metabolism
- Animals
- Base Sequence
- Biological Transport
- Blotting, Northern
- Chromosome Mapping
- Chromosomes, Human, Pair 14/genetics
- Cloning, Molecular
- Fusion Regulatory Protein 1, Light Chains/biosynthesis
- Fusion Regulatory Protein 1, Light Chains/chemistry
- Fusion Regulatory Protein 1, Light Chains/genetics
- Humans
- Immunohistochemistry
- In Situ Hybridization, Fluorescence
- In Vitro Techniques
- Kidney Tubules, Proximal/metabolism
- Molecular Sequence Data
- Oocytes/metabolism
- Xenopus laevis
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Affiliation(s)
- Sun Young Park
- Department of Pediatrics, Kwangju Christian Hospital, Gwangju 503-715, Korea
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20
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Kim DK, Kim IJ, Hwang S, Kook JH, Lee MC, Shin BA, Bae CS, Yoon JH, Ahn SG, Kim SA, Kanai Y, Endou H, Kim JK. System L-amino acid transporters are differently expressed in rat astrocyte and C6 glioma cells. Neurosci Res 2005; 50:437-46. [PMID: 15567481 DOI: 10.1016/j.neures.2004.08.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Accepted: 08/11/2004] [Indexed: 11/18/2022]
Abstract
The system L-amino acid transporter is a major nutrient transport system that is responsible for Na+-independent transport of neutral amino acids including several essential amino acids. We have compared and examined the expressions and functions of the system L-amino acid transporters in both rat astrocyte cultures and C6 glioma cells. The rat astrocyte cultures expressed the l-type amino acid transporter 2 (LAT2) with its subunit 4F2hc, whereas the l-type amino acid transporter 1 (LAT1) was not expressed in these cells. The C6 glioma cells expressed LAT1 but not LAT2 with 4F2hc. The [14C]l-leucine uptakes by the rat astrocyte cultures and C6 glioma cells were Na+-independent and were completely inhibited by the system l selective inhibitor, BCH. These results suggest that the transport of neutral amino acids including several essential amino acids into rat astrocyte cultures and C6 glioma cells are for the most part mediated by LAT2 and LAT1, respectively. Therefore, the rat astrocyte cultures and C6 glioma cells are excellent tools for examining the properties of LAT2 and LAT1, respectively. Moreover, the specific inhibition of LAT1 in cancer cells might be a new rationale for anti-cancer therapy.
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MESH Headings
- Amino Acid Transport System y+/drug effects
- Amino Acid Transport System y+/metabolism
- Amino Acids, Cyclic/pharmacology
- Amino Acids, Neutral/metabolism
- Animals
- Animals, Newborn
- Astrocytes/metabolism
- Biological Transport, Active/physiology
- Brain/metabolism
- Brain/physiopathology
- Brain Neoplasms/drug therapy
- Brain Neoplasms/metabolism
- Carbon Radioisotopes/metabolism
- Cell Line, Tumor
- Cells, Cultured
- Fusion Regulatory Protein 1, Heavy Chain/metabolism
- Fusion Regulatory Protein 1, Light Chains/drug effects
- Fusion Regulatory Protein 1, Light Chains/metabolism
- Glioma/drug therapy
- Glioma/metabolism
- Large Neutral Amino Acid-Transporter 1/drug effects
- Large Neutral Amino Acid-Transporter 1/metabolism
- Leucine/metabolism
- Rats
- Rats, Wistar
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Affiliation(s)
- Do Kyung Kim
- Department of Oral Physiology, Chosun University College of Dentistry, 375 Seosuk-dong, Dong-gu, Gwangju, 501-759, South Korea.
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21
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Yoon JH, Kim IJ, Kim H, Kim HJ, Jeong MJ, Ahn SG, Kim SA, Lee CH, Choi BK, Kim JK, Jung KY, Lee S, Kanai Y, Endou H, Kim DK. Amino acid transport system L is differently expressed in human normal oral keratinocytes and human oral cancer cells. Cancer Lett 2004; 222:237-45. [PMID: 15863273 DOI: 10.1016/j.canlet.2004.09.040] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2004] [Accepted: 09/07/2004] [Indexed: 11/22/2022]
Abstract
Previously, we reported the expression and function of system L amino acid transporter in KB human oral epidermoid carcinoma cells. In the present study, therefore, we investigated the expression and function of system L amino acid transporter in human normal oral keratinocytes (HNOK) and compared the expressions and functions of system L amino acid transporters in HNOK and KB cells. The HNOK expressed L-type amino acid transporter 1 (LAT1) and L-type amino acid transporter 2 (LAT2) with their subunit 4F2hc in the plasma membrane but the expression of LAT1 was very weak, which is in contrast to the KB cells expressing LAT1 but not LAT2 with the 4F2hc in the plasma membrane. The [14C] L-leucine uptake by HNOK, as well as KB cells, was inhibited by the system L selective inhibitor BCH. The majority of [14C] L-leucine uptake was, therefore, mainly mediated by LAT2 in the HNOK and by LAT1 in the KB cells. These results suggest that the transport of neutral amino acids including several essential amino acids into the HNOK and KB cells are mainly mediated by LAT2 and LAT1, respectively. The specific inhibition of LAT1 in oral cancer cells could be a new rationale for anti-cancer therapy.
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Affiliation(s)
- Jung Hoon Yoon
- Oral Biology Research Institute, Chosun University College of Dentistry, Gwangju 501-759, Korea
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