Transcriptome of breast tumor with different amplification statuses of long arm of chromosome 8

Abstract

The aim of this work was to study changes in the breast tumor transcriptome and the amplification status of the long arm of chromosome 8 (with locus 8q24) and in the process of pre-surgery chemotherapy. The study used paired samples of biopsy material before treatment and surgical material from 60 patients with breast cancer of luminal B subtype who received 4-8 courses of NAC. It was shown that in 65% of cases, amplification of 8q is preserved in the tumor after NAC. Top-10 DEG signaling pathways in the tumor of breast cancer patients before treatment and after NAC with the presence of amplification of 8q are shown. DEG of patients with different amplification statuses of 8q (with region 8q24) before treatment and after NAC overlap in8 genes. In the residual tumor of patients with amplification of 8q, an increase in the expression of stemness genes GSK3B, MYC, GATA3, SMAD4, SMAD2 participating in WNT and TGFb syngnaling was found. The study shows a large effect of amplification of the long arm of chromosome 8 on the tumor transcriptome in breast cancer, regardless of other molecular genetic features. Amplification of 8q involving region 8q24 leads to a significant shift in the level of transcription of a large number of genes precisely after exposure to chemotherapy.