title: Telomere length, TERT and shelterin complex proteins in hepatocellular carcinomas expressing "stemness"-related markers.
abstract: OBJECTIVE
  Hepatocellular carcinomas (HCCs) expressing "stemness"-related markers have been associated with aggressive biological behavior and poor prognosis. We examined the relationship between "stemness"-related protein expression and telomere length, hTERT and shelterin complex protein expression and chromosomal instability.
  
  
  METHODS
  Quantitative fluorescent in situ hybridization for telomere length, immunohistochemistry for K19, EpCAM, CD133, c-kit, HepPar1, hTERT, TRF1, TRF2, POT1, RAP1 and TPP1, and TUNEL assay were performed in 137 HCCs, and array comparative genomic hybridization was performed with 24 HCCs.
  
  
  RESULTS
  Telomeres were significantly longer in HCCs expressing "stemness"-related proteins (K19: p < 0.001, EpCAM: p = 0.002, CD133: p = 0.002). On analyzing different tumor cells within EpCAM-expressing HCCs, EpCAM-positive tumor cells showed longer telomeres (1.329 ± 0.246) compared to EpCAM-negative tumor cells (0.996 ± 0.381) within the same HCCs (p = 0.031). Telomeres were significantly longer in HCCs expressing hTERT (p = 0.048) and RAP1 proteins (p = 0.031). K19-expressing HCCs expressed hTERT (p = 0.002), TRF2 (p = 0.001) and TPP1 (p = 0.013) more frequently compared to K19-negative HCCs. EpCAM-positivity was associated with more frequent hTERT (p = 0.028), TPP1 (p = 0.017), TRF2 (p = 0.027) and POT1 (p = 0.004) expression. Copy number alterations were more frequent in K19 and EpCAM-expressing HCCs compared to HCCs without these markers (K19: p = 0.038, EpCAM: p = 0.009). HCCs with longer telomeres were associated with a shorter overall (p = 0.019) and disease-free survivals (p = 0.049), and decreased disease-free survivals were seen in TRF2-positive HCCs (p = 0.018).
  
  
  CONCLUSIONS
  HCCs expressing "stemness"-related proteins are characterized by increased telomere length, increased expression of hTERT and shelterin complex proteins, and increased chromosomal instability compared to conventional HCCs. Longer telomeres and TRF2 expression in HCCs are associated with poor patient outcomes.
authors.affiliation: Department of Pathology, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Haeryoung
authors.initials: H
authors.lastname: Kim
authors.forename: Jeong Eun
authors.initials: JE
authors.lastname: Yoo
authors.forename: Jai Young
authors.initials: JY
authors.lastname: Cho
authors.forename: Bong-Kyeong
authors.initials: BK
authors.lastname: Oh
authors.forename: Yoo-Seok
authors.initials: YS
authors.lastname: Yoon
authors.forename: Ho-Seong
authors.initials: HS
authors.lastname: Han
authors.forename: Hye Seung
authors.initials: HS
authors.lastname: Lee
authors.forename: Ja June
authors.initials: JJ
authors.lastname: Jang
authors.forename: Sook Hyang
authors.initials: SH
authors.lastname: Jeong
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Kim
authors.forename: Young Nyun
authors.initials: YN
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000378:metabolism; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000378:metabolism; D049109:Cell Proliferation; D043171:Chromosomal Instability; D000071858:Epithelial Cell Adhesion Molecule; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D053539:Keratin-19 / Q000378:metabolism; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology; D011379:Prognosis; D000089804:Shelterin Complex; D019098:Telomerase / Q000378:metabolism*; D059505:Telomere Homeostasis / Q000235:genetics / Q000502:physiology*; D034501:Telomere-Binding Proteins / Q000378:metabolism*; D035341:Telomeric Repeat Binding Protein 2 / Q000378:metabolism
chemical_list: C495876:ACD protein, human; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule; D053539:Keratin-19; D000089804:Shelterin Complex; C504753:TERF2 protein, human; D034501:Telomere-Binding Proteins; D035341:Telomeric Repeat Binding Protein 2; C509186:TERT protein, human; D019098:Telomerase
keywords: BAC; CGH; EpCAM; HCC; Hepatocellular carcinoma; K19; LI; LT; POT1; POT1-TIN2 organizing protein; Q-FISH; RAP1; ST; Shelterin; Stemness; TERT; TFI/CFI ratio; TGF-β; TIN2; TPP1; TRF; TRF1-interacting protein 2; TUNEL; Telomere; bacterial artificial chromosome; comparative genomic hybridization; epithelial cell adhesion molecule; hepatocellular carcinoma; keratin 19; labeling index; long telomere; protection of telomeres 1; quantitative fluorescent in situ hybridization; repressor/activator protein 1; short telomere; telomere/centromere fluorescence intensity ratio; telomeric repeat-binding factor; transferase-mediated dUTP-biotin nick end labeling; transforming growth factor-β