Tuberc Respir Dis.
2000 Jan;48(1):24-32.
Microsatellite Instability in Non-Small Cell Lung Cancer
- Affiliations
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- 1Cancer Research Institute, Kyungpook National University, Korea.
- 2Department of Anatomic Pathology, School of Medicine, Kyungpook National University, Korea.
- 3Department of Internal Medicine, School of Medicine, Kyungpook National University, Korea.
- 4Department of Biochemistry, School of Medicine, Kyungpook National University, Korea.
Abstract
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PURPOSE: Microsatellite instability (MSI) is frequently used as an
indicative of microsatellite mutator phenotype (MMP) tumors.
MSI has been observed in a fraction of non-small cell lung cancer
(NSCLC). However, its role in tumorigenesis of NSCLC remains unknown.
We evaluated the frequency and pattern of MSI in NSCLC, and compared
the clinical parameters of MSI-positive tumors with those of MSS
(microsatellite stable) tumors.
MATERIALS AND METHODS
Twenty surgically resected NSCLCs were analyzed
for 15 microsatellite markers located at chromosome 3p and 9p.
Patients' peripheral blood lymphocytes were used as the source of
the normal DNA.
RESULTS
1) Of 20 cases, 8 (40%) demonstrated MSI.
2) Instability observed more commonly in tri- and tetra-nucleotide
repeats rather than dinucleotide repeats. In all cases, instability
appeared as a shift of individual allelic bands. 3) LOH was observed
in 10 (50%) of 20 tumors analyzed. 4) Of 20 cases, MSI-H tumor
(showing MSI in the majority of markers) was absent. There were 5 MSI-L
tumors (showing MSI in a greater than 10% of markers). 5) No significant
difference was observed between MSI-L tumors and MSI-negative tumors
in clinicopathologic features such as pack-year history of smoking,
histologic subtype, and the stage of disease. There was also no
significant difference in the incidence of LOH according to the status
of MSI.
CONCLUSION
These data strongly suggest that MSI has different
roles in lung and colon cancer. MMP pathway appears far less important
in the tumorigenesis of NSCLC, caused mainly by cigarette smoke,
with little familial tendency.