title: Correlation analysis between the expression of P21WAF1/CIP1, P16 proteins and human glioma.
abstract: OBJECTIVE
  Glioma is the most common neoplasm of the brain. Unfortunately, surgical cure of it is practically impossible and clinical course is primarily determined by the biological behaviour of the tumour cells. The purpose of this study was to investigate the correlation between the expression levels of P21WAF1/CIP1, P16 proteins and the grading of glioma.
  
  
  METHODS
  T98G human glioma cell line, normal human astrocyte (HA) cell line, tumour tissue samples from 70 patients suffering from glioma and normal brain tissues from 20 cases with brain contusion were investigated. The expression levels of P21WAF1/CIP1 and P16 proteins were detected using SABC immunohistochemical staining and semi-quantitive reverse transcriptase polymerase chain reaction (RT-PCR) assay. Then, the correlation of the two markers' expression with glioma grading of patients was analysed.
  
  
  RESULTS
  The expression levels of P21WAF1/CIP1 and P16 proteins in the T98G cell line were much lower than that in the HA cell line. Their positive expression rates in glioma tissues were 55.71% and 42.86% respectively, and a significant increase was observed in normal brain tissues (p = 0.012, 0.008). Combined with the result of semi-quantitive RT-PCR, we could demonstrate that the expression intensity of P21WAF1/CIP1 and P16 decreased with the glioma grade increase. Co-expression of them was also found in glioma and normal brain tissues. Furthermore, there was a negative correlation between the two markers' expression and glioma grading of patients (rs = -0.68, -0.56).
  
  
  CONCLUSIONS
  The positive expression rate and co-expression rate of P21WAF1/CIP1 and P16 proteins could reflect the malignant grade of glioma to some extent, and they can be considered as a sensitive index for glioma grading.
authors.affiliation: Neurosurgery Department, Xiangya Hospital of Central South University, Changsha, Hunan, P.R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.forename: Fanghua
authors.initials: F
authors.lastname: Chen
authors.forename: Lei
authors.initials: L
authors.lastname: Huo
authors.forename: Mingyu
authors.initials: M
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Wu
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhai
authors.forename: Liang
authors.initials: L
authors.lastname: Yang
authors.forename: Jiesheng
authors.initials: J
authors.lastname: Fang
mesh_terms: D001483:Base Sequence; D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D017931:DNA Primers; D005910:Glioma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D009363:Neoplasm Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C493956:CDKN1A protein, human; C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D017931:DNA Primers; D009363:Neoplasm Proteins
references.citation: Clin Cancer Res. 2001 Aug;7(8):2387-95
references.pmid: 11489817
references.citation: Am J Surg Pathol. 2002 Apr;26(4):472-8
references.pmid: 11914625
references.citation: Brain Tumor Pathol. 1998;15(2):89-94
references.pmid: 10328545
references.citation: Curr Opin Oncol. 2004 Nov;16(6):607-13
references.pmid: 15627025
references.citation: Curr Biol. 1997 Apr 1;7(4):261-9
references.pmid: 9094314
references.citation: Neuropathology. 2007 Feb;27(1):10-20
references.pmid: 17319279
references.citation: Acta Neuropathol. 1998 Jun;95(6):617-24
references.pmid: 9650754
references.citation: Cancer Res. 2005 May 15;65(10):4051-8
references.pmid: 15899794
references.citation: Wien Med Wochenschr. 2006 Jun;156(11-12):332-7
references.pmid: 16944363
references.citation: Hum Mol Genet. 2001 Apr;10(7):699-703
references.pmid: 11257102
references.citation: Strahlenther Onkol. 2002 Sep;178(9):491-6
references.pmid: 12426835
references.citation: J Neurooncol. 2004 Jun;68(2):113-21
references.pmid: 15218947
references.citation: Mol Cell Biol. 2000 Jul;20(13):4580-90
references.pmid: 10848585
references.citation: Neurosurgery. 2003 Jun;52(6):1425-34; discussion 1434-5
references.pmid: 12762887
references.citation: Curr Neurol Neurosci Rep. 2004 May;4(3):228-33
references.pmid: 15102349
references.citation: Strahlenther Onkol. 2005 Mar;181(3):164-71
references.pmid: 15756520
references.citation: Biochem Biophys Res Commun. 2001 Sep 14;287(1):173-80
references.pmid: 11549271
references.citation: Biochem Biophys Res Commun. 2000 Mar 24;269(3):718-25
references.pmid: 10720483
references.citation: Cancer Res. 2000 Mar 1;60(5):1383-7
references.pmid: 10728703
references.citation: Gene Ther. 2001 Feb;8(3):199-208
references.pmid: 11313791