title: Stem cell genes are poorly expressed in chondrocytes from microtic cartilage.
abstract: OBJECTIVE
  This study was aimed to see the difference between chondrocytes from normal cartilage compared to chondrocytes from microtic cartilage. Specific attentions were to characterize the growth of chondrocytes in terms of cell morphology, growth profile and RT-PCR analysis.
  
  
  METHODS
  Laboratory experiment using auricular chondrocytes.
  
  
  METHODS
  Chondrocytes were isolated from normal and microtic human auricular cartilage after ear reconstructive surgeries carried out at the Universiti Kebangsaan Malaysia Medical Centre. Chondrocytes were cultured in vitro and subcultured until passage 4. Upon confluency, cultured chondrocytes at each passage (P1, P2, P3 and P4) were harvested and subjected to growth profile and gene expression analyses. Comparison was made between the microtic and normal chondrocytes.
  
  
  RESULTS
  For growth profile analysis cell viability did not show significant differences between both samples. There are no significance differences between both samples in terms of its growth rate, except in passage 1 where microtic chondrocytes were significant lower in their growth rate. Population doubling time and total number of cell doubling of all samples also did not show any significant differences. Gene expression is measured using Real Time-Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). There is no significant differences in the expression of collagen type I, collagen type II, collagen type X, aggrecan core protein, elastin and sox9 genes in both samples. There are significant lower in the expression of sox2, nestin, BST-1 and OCT-4 gene in microtic chondrocytes compared to the normal chondrocytes. Stem cells markers are included in this study as stemness in cells may imply a greater proliferative potential and plasticity in vitro.
  
  
  CONCLUSIONS
  Chondrocytes from microtic samples have the same properties as chondrocytes from normal samples and hold promises to be used as a starting material in the reconstruction of the external ear in future clinical application. The reduction in sox2, nestin, BST-1 and OCT-4 gene expression in microtic samples could be the possible cause of the arrested development of the external ear.
authors.affiliation: Dept. of Otorhinolaryngology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia.
authors.forename: M F
authors.initials: MF
authors.lastname: Ishak
authors.forename: K H
authors.initials: KH
authors.lastname: Chua
authors.forename: A
authors.initials: A
authors.lastname: Asma
authors.forename: L
authors.initials: L
authors.lastname: Saim
authors.forename: B S
authors.initials: BS
authors.lastname: Aminuddin
authors.forename: B H I
authors.initials: BH
authors.lastname: Ruszymah
authors.forename: B S
authors.initials: BS
authors.lastname: Goh
mesh_terms: D036541:ADP-ribosyl Cyclase / Q000235:genetics / Q000378:metabolism; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D016022:Case-Control Studies; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000235:genetics*; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D000013:Congenital Abnormalities / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D065817:Congenital Microtia; D004423:Ear / Q000002:abnormalities / Q000473:pathology; D004425:Ear Cartilage / Q000378:metabolism / Q000473:pathology*; D058851:GPI-Linked Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007381:Intermediate Filament Proteins / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D064231:Nestin; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology*
chemical_list: D015703:Antigens, CD; D058851:GPI-Linked Proteins; D007381:Intermediate Filament Proteins; C577484:NES protein, human; D009419:Nerve Tissue Proteins; D064231:Nestin; D050814:Octamer Transcription Factor-3; D012333:RNA, Messenger; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; D036541:ADP-ribosyl Cyclase; C087521:ADP-ribosyl cyclase 2