Titolo progetto: AIRC 2017 - Dissecting the heterogeneity of circulating tumor cells in metastatic breast cancer patients to predict clinical outcome

Programma di finanziamento: Bando AIRC 2017

Responsabile scientifico: prof.ssa Daniela Cesselli

Ruolo del DAME: proponente unico

Descrizione generale:

The isolation and characterization of circulating tumor cells -CTC- (i.e. rare cells shed into the bloodstream from primary tumors and metastases) are hot topics of translational cancer research. CTC might represent an active source of metastatic spread from a primary tumor to secondary lesions, and their role as prognostic and predictive biomarker has been robustly demonstrated both in primary and metastatic breast cancer (MBC). However, most CTC studies are based on the CellSearch System (Veridex), the only FDA-approved device that detects CTC based on the expression of EpCAM. However, this surface antigen can be lost by CTC in epithelial-to-mesenchymal transition (EMT), a phenomenon associated with an invasive phenotype of breast cancer. We developed a method able to enrich peripheral blood samples in CTC, independently from EpCAM expression. By using an antibody cocktail recognizing epithelial (E+) and mesenchymal (M+) markers and taking advantage of the DEPArray technology, we detected and quantified, for the first time in MBC patients, 4 classes of CD45NEG cells. Most importantly, we observed a significant association between specific CD45NEG subpopulations, metastatization pattern and clinical outcome.

The prospective observational study will enroll 240 MBC patients regardless the line of treatment. Our optimized DEPArray[1]based protocol will be applied to MBC blood samples to identify and quantify the four circulating CD45NEG subpopulations. The association of these latter with clinicopathological features (including brain metastasis), progression free survival, and overall survival will be explored by Wilcoxon-Mann-Whitney test and Univariate/Multivariate Cox Regression Analyses, respectively. In order to dissect the genetic heterogeneity of the CD45NEG cell subpopulations, single cells will be sorted by DEPArray and analyzed by adopting a modular approach that includes both low-pass whole-genome sequencing and census-based whole[1]exome sequencing, to obtain a robust and accurate detection of somatic single-nucleotide variants and copy number alterations. Finally, as a proof of concept, to investigate the association between NEG cells and brain metastasis in triple negative MBC (TN-MBC), we will analyze their trascriptome and in vitro and in vivo function.

Date inizio e fine progetto: 02.01.2018 – 30.09.2024

Budget totale del progetto: 444.000,00€