title: Tryptophan hydroxylase 1 and 5-HT7receptor preferentially expressed in triple-negative breast cancer promote cancer progression through autocrine serotonin signaling.
abstract: Triple-negative breast cancer (TNBC) has a high risk of relapse and there are few chemotherapy options. Although 5-hydroxytryptamine (5-HT, serotonin) signaling pathways have been suggested as potential targets for anti-cancer drug development, the mechanism responsible for the action of 5-HT in TNBC remains unknown.
  
  
  
  Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used to measure mRNA and protein levels, respectively. Cell proliferation was measured using CellTiter 96 Aqueous One Solution. siRNA transfection was used to assess involvement of genes in cancer invasion, which were identified by Matrigel transwell invasion assay. Levels of 5-HT and vascular endothelial growth factor (VEGF) were measured using ELISA kits. Chick chorioallantoic membrane (CAM) assay and mouse tumor model were used to investigate the in vivo effects of SB269970, a 5-HT7receptor antagonist, and BJ-1113, a novel synthetic compound.
  
  
  
  TNBC cell lines (MDA-MB-231, HCC-1395, and Hs578T) expressed higher levels of tryptophan hydroxylase 1 (TPH1) than hormone-responsive breast cancer cell lines (MCF-7 and T47D). In MDA-MB-231 cells, 5-HT promoted invasion and proliferation via 5-HT7receptor, and interestingly, the stimulatory effect of 5-HT on MDA-MB-231 cell invasion was stronger than its effect on proliferation. Likewise, downstream signaling pathways of 5-HT7differed during invasion and proliferation, that is, Gα-activated cAMP and Gβγ-activated kinase signaling during invasion, and Gβγ-activated PI3K/Akt signaling during proliferation. Also, 5-HT increased the protein expressions of TPH1 and VEGF in MDA-MB-231 cells. These results provide insight of the stimulatory effect of 5-HT on breast cancer progression; 5-HT was found to act more strongly during the first stage of metastasis (during invasion and migration) than during the later proliferative phase after local invasion. Interestingly, these actions of 5-HT were inhibited by BJ-1113, a 6-amino-2,4,5-trimethylpyridin-3-ol analog. BJ-1113 blocked intracellular signaling pathways initiated by 5-HT7receptor activation, and exhibited anti-proliferative and anti-invasive activities against MDA-MB-231 cells. Furthermore, the inhibitory effect of BJ-1113 against MDA-MB-231 tumor growth was greater than that of SB269970, a 5-HT7receptor antagonist.
  
  
  
  5-HT7receptor which mediates 5-HT-induced cancer progression is a potential therapeutic target in TNBC, and BJ-1113 offers a novel scaffold for the development of anti-cancer agents against TNBC.
authors.affiliation: College of Pharmacy, Yeungnam University, 280 Daehak-Ro, Gyeongsan, 38541, Republic of Korea.
authors.forename: Jaya
authors.initials: J
authors.lastname: Gautam
authors.affiliation: College of Pharmacy, Yeungnam University, 280 Daehak-Ro, Gyeongsan, 38541, Republic of Korea.
authors.forename: Suhrid
authors.initials: S
authors.lastname: Banskota
authors.affiliation: College of Pharmacy, Yeungnam University, 280 Daehak-Ro, Gyeongsan, 38541, Republic of Korea.
authors.forename: Sushil Chandra
authors.initials: SC
authors.lastname: Regmi
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
authors.forename: Subi
authors.initials: S
authors.lastname: Ahn
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Jeon
authors.affiliation: Departments of Pharmacy Practice and Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, 60612, USA.
authors.forename: Hyunyoung
authors.initials: H
authors.lastname: Jeong
authors.affiliation: College of Pharmacy, Yeungnam University, 280 Daehak-Ro, Gyeongsan, 38541, Republic of Korea.
authors.forename: Seung Joo
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Pharmacy, Hanyang University, Ansan, 15588, Republic of Korea.
authors.forename: Tae-Gyu
authors.initials: TG
authors.lastname: Nam
authors.affiliation: College of Pharmacy, Yeungnam University, 280 Daehak-Ro, Gyeongsan, 38541, Republic of Korea. jeongb@ynu.ac.kr.
authors.forename: Byeong-Seon
authors.initials: BS
authors.lastname: Jeong
authors.affiliation: College of Pharmacy, Yeungnam University, 280 Daehak-Ro, Gyeongsan, 38541, Republic of Korea. jakim@yu.ac.kr.
authors.forename: Jung-Ae
authors.initials: JA
authors.lastname: Kim
mesh_terms: D000818:Animals; D019898:Autocrine Communication; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D000242:Cyclic AMP / Q000378:metabolism; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D006801:Humans; D051379:Mice; D008954:Models, Biological; D011985:Receptors, Serotonin / Q000235:genetics* / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism* / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D064726:Triple Negative Breast Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D014365:Tryptophan Hydroxylase / Q000235:genetics* / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D042461:Vascular Endothelial Growth Factor A; C104425:serotonin 7 receptor; D012701:Serotonin; D000242:Cyclic AMP; C497467:TPH1 protein, human; D014365:Tryptophan Hydroxylase
keywords: 5-HT7 receptor; 6-Amino-2,4,5-trimethylpyridin-3-ol; Autocrine 5-HT action; Triple negative breast cancer; Tryptophan hydroxylase 1