Epsilon Archive for Student Projects

Abstract

Somatic mosaicism is the presence of genetically diverse lineage of somatic cells within an organism even though deriving from a single zygote. Mosaicism is known to occur in many diseases. Breast cancer is the second most cause of deaths in woman caused by malignant tumor. Breast cancer was a common malignancy and main cause of morbidity and disease related mortality among women. By studying the genetic profiles of the cells surrounding the primary tumor and blood of same patient may reveal the cause of tumor cells. The purpose of this study was to identify the presence of somatic mosaicism in healthy uninvolved margin of breast tissue surrounding the primary tumor and blood of breast cancer patient by using Illumina 1M BeadChip and Nimblegen 720K array.

So far, all long and very rigorous research explains only 10% of the breast cancer. This indicates the complexity of cancer and the factors responsible for the development of tumor in healthy tissues. Results from whole genome genotyping by Illumina 1M beadchip of blood and cells surrounding the primary tumor of same patient indicate the presence of somatic mosaicism in chromosome 6, 8 and 18 of ML36B (uninvolved margin), ML36A2 and ML36A3 (primary tumor) which was confirmed by genotyping with Nimblegen 720K microarrays. Genotyping also showed the presence of genomic imbalance in genetic makeup of the healthy tissue surrounding the primary tumor.

It is to be likely that rate of discovery of somatic mosaicism in the small proportion of studies cells might continue to accelerate the studies on genetic heterogeneity of breast malignancies. As well as studies by comparing the genetic profiles of tumours and tissue surrounding the primary tumour may lead to identify the genomic aberrations in context to cancer progression.