title: p21WAF1/CIP1 gene DNA sequencing and its expression in human osteosarcoma.
abstract: BACKGROUND
  Mutation and expression change of p21WAF1/CIP1 may play a role in the growth of osteosarcoma. This study was to investigate the expression of the p21WAF1/CIP1 gene in human osteosarcoma, p21WAF1/CIP1 gene DNA sequence change and their relationships with the phenotype and clinical prognosis.
  
  
  METHODS
  p21WAF1/CIP1 gene in 10 normal people and the tumours of 45 osteosarcoma patients were examined using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) with silver staining. The PCR product with an abnormal strand was sequenced directly. The p21WAF1/CIP1 gene mRNA and P21 protein of 45 cases of osteosarcoma were investigated by using in situ hybridization and immunohistochemistry, respectively.
  
  
  RESULTS
  The occurrence of P21 protein in osteosarcoma was 17.78% (8/45), and p21WAF1/CIP1 mRNA expression in osteosarcoma was 42.22% (19/45). The p21WAF1/CIP1 gene DNA sequencing of amplified production showed that in p21WAF1/CIP1 gene exon 3 of 36 cases of human osteosarcoma, there were 17 cases (47.22%) with C-->T at position 609; 10 normal blood samples' DNA sequence analysis yielded 8 cases (80.00%) with C-->T at the same position.
  
  
  CONCLUSIONS
  Along with the increase of malignancy, the expression of p21WAF1/CIP1mRNA and P21 protein in osteosarcoma tends to decrease. It is uncommon for the p21WAF1/CIP1 gene mutation to occur in human osteosarcoma. As a result, the possible existence of tumour subtypes of p21WAF1/CIP1 gene mutation should be investigated. Our research leads to the location of p21WAF1/CIP1 gene polymorphism of Chinese osteosarcoma patients, which can provide a basis for further research.
authors.affiliation: Department of Orthopaedics, First Affiliated Hospital, Sun Yat-sen University, Guangdong 510080, China.
authors.forename: Wei-ming
authors.initials: WM
authors.lastname: Liao
authors.forename: Chun-lin
authors.initials: CL
authors.lastname: Zhang
authors.forename: Fo-bao
authors.initials: FB
authors.lastname: Li
authors.forename: Bing-fang
authors.initials: BF
authors.lastname: Zeng
authors.forename: Yi-xin
authors.initials: YX
authors.lastname: Zeng
mesh_terms: D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000235:genetics*; D006801:Humans; D012516:Osteosarcoma / Q000235:genetics*; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D012333:RNA, Messenger / Q000032:analysis; D017422:Sequence Analysis, DNA
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D012333:RNA, Messenger