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Differential expression of DNA topoisomerase II alpha and II beta genes between small cell and non-small cell lung

E Syahruddin1, T Oguri, T Takahashi

  • 1Second Department of Internal Medicine, Hiroshima University School of Medicine.

Japanese Journal of Cancer Research : Gann
|October 10, 1998
PubMed

Insights

Lung cancer drug sensitivity differs between small cell (SCLC) and non-small cell (NSCLC) types. DNA topoisomerase II alpha (Topo II alpha) gene expression is higher in tumors, especially SCLC, suggesting it impacts treatment response.

Area of Science:

  • Molecular Biology
  • Oncology
  • Genetics

Background:

  • DNA topoisomerase II (Topo II) inhibitors are crucial in lung cancer chemotherapy.
  • Differential sensitivity to Topo II inhibitors exists between small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).
  • Understanding Topo II isoform expression may elucidate these sensitivity differences.

Purpose of the Study:

  • To investigate differential gene expression of DNA topoisomerase II alpha (Topo II alpha) and Topo II beta isoforms in lung cancer.
  • To compare Topo II isoform expression between SCLC and NSCLC.
  • To explore the association between Topo II expression and sensitivity to Topo II inhibitors.

Main Methods:

  • Gene expression levels of Topo II alpha and Topo II beta were assessed.
  • Samples included 40 primary lung tumors and 40 corresponding normal lung tissues from autopsy.
  • Reverse transcription polymerase chain reaction (RT-PCR) was employed for gene expression analysis.

Main Results:

  • Topo II alpha expression was significantly elevated in lung tumors compared to normal tissues.
  • Topo II alpha expression was significantly higher in SCLC tumors than in NSCLC tumors.
  • No significant differences in Topo II beta expression were observed between tumor and normal tissues, or between SCLC and NSCLC.

Conclusions:

  • Differential regulation of Topo II alpha exists between lung tumors and normal lung tissues.
  • The elevated Topo II alpha expression in SCLC compared to NSCLC suggests a role in differential drug sensitivity.
  • Topo II alpha expression levels are potentially associated with patient response to Topo II inhibitor chemotherapy.

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