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Clinicopathological Analysis of miRNA Expression in Breast Cancer Tissues by Using miRNA In Situ Hybridization
Published on: June 7, 2016
Evidence for microsatellite instability in bilateral breast carcinomas
E N Imyanitov1, A V Togo, E N Suspitsin
1Group of Molecular Diagnostics and Laboratory of Pathomorphology, N. N. Petrov Institute of Oncology, St. Petersburg, Russia. evgeny@imyanitov.spb.ru
Cancer Letters
|May 9, 2000
Summary
This study investigated genetic mutations in bilateral breast cancer (BC), finding loss of heterozygosity (LOH) patterns similar to unilateral BC. However, a notable percentage of bilateral BC cases exhibited microsatellite instability (MI), a feature less common in unilateral forms.
Area of Science:
- Oncology
- Genetics
- Molecular Biology
Background:
- The molecular basis of breast cancer (BC) is understood, yet bilateral BC somatic mutations are understudied.
- Loss of heterozygosity (LOH) is a known genetic alteration in various cancers.
Purpose of the Study:
- To analyze somatic mutations, specifically LOH and microsatellite instability (MI), in bilateral breast cancer (BC).
- To compare genetic mutation profiles of bilateral BC with those of unilateral BC.
Main Methods:
- Polymerase chain reaction (PCR)-driven investigation of chromosomal regions with common LOH in 23 bilateral BC cases (46 tumors).
- Analysis of dinucleotide CA repeat shortening and the BAT-26 marker to assess microsatellite instability (MI).
Main Results:
- LOH was observed across multiple chromosomes (1p, 5q, 11q, 13q, 17p) at frequencies comparable to unilateral BC.
- 15% of bilateral BC tumors showed high frequencies of shortened CA repeats, indicating microsatellite instability (MI).
- Two tumors were classified as replication error positive (RER(+)/MSI-H), and five as borderline MI, suggesting distinct MI involvement in bilateral BC.
Conclusions:
- Bilateral breast cancer (BC) exhibits LOH patterns similar to unilateral BC.
- Microsatellite instability (MI), including RER(+) and borderline types, appears to be a distinguishing genetic feature of bilateral BC compared to unilateral lesions.
