J Lung Cancer.  2010 Dec;9(2):72-76. 10.6058/jlc.2010.9.2.72.

Mutational and Expressional Analysis of ATG5 Gene in Non-Small Cell Lung Cancers

• Kim MS
• Yoo NJ
• Lee SH

• KMID: 2199907
• DOI: http://doi.org/10.6058/jlc.2010.9.2.72

Abstract

PURPOSE
Several lines of evidence have indicated that perturbations of autophagy are involved in the development of many human diseases, including cancer. The autophagy-related genes (ATG) encode proteins that play important roles in autophagic processes. The aim of this study was to see whether alterations of the ATG5 protein expression and somatic mutations of the ATG5 gene are present in human non-small cell lung cancers (NSCLCs).
MATERIALS AND METHODS
We analyzed the ATG5 somatic mutations in 45 NSCLCs by performing single-strand conformation polymorphism (SSCP). We examined the ATG5 protein expression in 45 NSCLCs by performing immunohistochemistry.
RESULTS
The SSCP analysis revealed no evidence of somatic mutation in the DNA sequences encoding the ATG5 gene in the 45 NSCLCs. On the immunohistochemistry, ATG5 protein was expressed in the normal bronchial epithelial cells, while it was lost in 9 (20%) of the NSCLCs.
CONCLUSION
Our data indicates that ATG5 is altered in NSCLC at the expressional level, but not at the mutational level. The data also suggests that the loss of expression of ATG5 might play a role in the pathogenesis of NSCLC by altering autophagic and apoptotic cell death.

Keyword

Non-small cell lung cancer; ATG5; Autophagy; Mutation

MeSH Terms

Autophagy
Base Sequence
Carcinoma, Non-Small-Cell Lung
Cell Death
Epithelial Cells
Humans
Immunohistochemistry
Lung
Lung Neoplasms
Polymorphism, Single-Stranded Conformational
Proteins
Proteins

Figure

• 

  Fig. 1. Representative single-strand conformation polymorphism (SSCP) of ATG5 gene in non-small cell lung cancers. Exon 5 of ATG5 gene was amplified by PCR using a specific primer set. The PCR products from three representative cases of non-small cell lung cancers were visualized on SSCP. SSCP of DNA from the non-small cell lung cancers (T) shows no aberrant bands as compared to SSCPs from the normal tissues (N).

• 

  Fig. 2. Visualization of ATG5 expression in non-small cell lung cancer tissues by immunohistochemistry. (A) A squamous cell carcinoma shows ATG5 immunostaining in the cancer cells. (B) A adenocarcinoma shows ATG5 immunostaining in the cancer cells. (C) In another adenocarcinoma, the cancer cells are negative for ATG5 immunostaining. (D) Normal bronchial epithelial cells are positive for ATG5 immunostaining (original magnification A∼ C, ×200; D, ×150).

Reference

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