RESUMO
Background: PI3K/Akt/mTOR pathway is a crucial pathway in the angiogenesis, tumour growth and cell differentiation of several cancers. The PI3K and KIT genes are key genes of this pathway. Previous studies have reported the importance of these genes in the development of gastrointestinal carcinoma, leukaemia, and melanomas. The role of mutations and overexpression of PI3K and KIT genes in breast cancer has been previously proved. This study investigates the correlation between PI3K and KIT gene mutations in sporadic breast cancer. Methods: Multiplex Ligation-dependent Probe Amplification (MLPA) technique was used to determine the Copy Number Variation (CNV) of PI3K and KIT genes in 34 breast cancer tumours and PCR-sequencing was used to detect the mutation in PI3K exons 9 and 20. Results: Our results reported that 27% of patients had CNV of the KIT gene; whereas, 20% and 17.5% of patients, had mutation and CNV in the PI3K gene, respectively. We did not found a significant correlation between the mutations of PI3K and KIT genes. Conclusion: About two-tenth of the patients revealed CNV and lesser than two-tenth indicated mutation in the PI3K gene, whereas one-third of the patients demonstrated CNV in the KIT gene. Thus, administration of the PI3K and KIT gene inhibitor drugs might be proposed to suppress breast cancer in patients with mutation and CNV of each of these individual genes.
RESUMO
BACKGROUND AND OBJECTIVE: The PI3K/AKT/mTOR pathway is known to play an important role in regulating angiogenesis both in normal and breast cancer (BC) tissues. PIK3CA amplification was reported in various malignancies, including approximately 10% of BC cases. The aim of this study was to identify the frequency of PIK3CA amplification in Iranian female patients suffering from BC. Additionally, possible association between PIK3CA amplification and P110α expression with microvascular density (MVD) was examined. METHODS: DNA samples were extracted from paraffin embedded tumor tissue blocks and copy number changes were evaluated by MLPA Technique. The results were analyzed by coffalyzer software. The tissue expression of P110α and CD34 was assessed using immunohistochemistry. RESULTS: Ten out of 40 samples (17.5%) showed amplification in PIK3CA gene and 22 out of 40 samples (55%) showed overexpression in P110α. For CD34, from 40 samples, 20 (50%), 15 (37.5%) and 5 (12.5%) had scores 1+, 2+ and 3+, respectively. CONCLUSION: No significant association was detected between gain of PIK3CA copy number and P110α or CD34 tissue expression.
