Overexpression of Pokemon in non-small cell lung cancer and foreshowing tumor biological behavior as well as clinical results

Lung Cancer. 2008 Oct;62(1):113-9. doi: 10.1016/j.lungcan.2008.02.014. Epub 2008 Jun 11.

Abstract

Background: Transcription factor Pokemon, a central regulation gene of the important tumor suppressor alternative reading frame (ARF), exerted its activity by acting upstream of many tumor-suppressing genes and proto-oncogenes. Its expression in non-small cell lung cancer (NSCLC) and its clinical significance remains unclear. The aim of this study was to investigate the expression of Pokemon in non-small cell lung cancer and to explore its correlation with the clinical pathological characteristics and its influence on patients' prognosis.

Aim: Observe the expression of Pokemon in NSCLC and investigate its mechanism and clinical significance.

Methods: Determine the expression of Pokemon in human NSCLC cell lines as well as 55 cases of NSCLC tumor tissues, tumor adjacent tissues and surrounding tissues by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, and analyze the relationship between Pokemon expression in NSCLC tumor tissues and clinicopathological features. Determine 62 NSCLC tumor tissues (5 years ago) and p14(ARF) expression with immunohistochemical technique, discuss the correlation between them and assess the effect of Pokemon on prognosis of patients with lung cancer.

Results: Pokemon mRNA and protein took on high expression in lung cancer cell lines, and the expression difference between cancer tissues, tumor adjacent tissues and surrounding tissues had statistical significance (P<0.05). Pokemon expression and p14(ARF) expression were negatively correlated (r=-0.287). The expression of Pokemon was determined not to be associated with the patient's sex, age, smoking condition, tumor differentiation degree, histology and lymph node metastasis condition. However, its relationship with TNM staging was established (P<0.05). Furthermore, it was shown that the survival rate of patients with negative Pokemon expression was significantly higher than that of those with positive Pokemon expression (P=0.004), therefore, the expression of Pokemon is believed to be an independent factor affecting prognosis (P=0.034).

Conclusion: There was high expression of Pokemon in NSCLC, Pokemon exerted carcinogenesis by inhibiting ARF and had some clinical significance for prognostic evaluation of the patients with NSCLC.

MeSH terms

  • Biomarkers, Tumor / analysis
  • Blotting, Western
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / pathology*
  • Cell Line, Tumor
  • DNA-Binding Proteins / biosynthesis*
  • DNA-Binding Proteins / genetics
  • Female
  • Humans
  • Immunohistochemistry
  • Kaplan-Meier Estimate
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / pathology*
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Prognosis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Factors / biosynthesis*
  • Transcription Factors / genetics
  • Tumor Suppressor Protein p14ARF / biosynthesis

Substances

  • Biomarkers, Tumor
  • DNA-Binding Proteins
  • Transcription Factors
  • Tumor Suppressor Protein p14ARF
  • ZBTB7A protein, human