Abstract 1999P
Background
EMT (epithelial-mesenchymal transition) features in CTCs (circulating tumour cells) determine their invasiveness, adaptability to the microenvironment, resistance to proapoptotic signals and chemotherapy. Intermediate epithelial-mesenchymal (hybrid) status is more efficient to the metastasis. So, we detected the EMT features in different subsets of CTCs in breast cancer patients.
Methods
The prospective study includes 43 patients with invasive breast cancer T2-4N0-3M0. Venous EDTA blood samples were taken one to two days before surgical intervention. The study was approved by the Local Committee for Medical Ethics. Phenotypic characteristics of CTCs were detected by flow cytometry using monoclonal anti-CD45, anti-CD44, anti-CD24, anti-EpCam, anti-CK7, anti-N-cadherin (CD325) and anti-Snail antibodies.
Results
The majority of CTCs had intermediate epithelial-mesenchymal status and the stem features were absent. The EpCam+CK7-CD45-CD44-CD24-Snail-N-cadherin- CTCs (without EMT and stem-like features) were detected in 100% cases and were numerous among other CTCs subsets (4.15 (0.59-11.62) cells per 1 ml of the peripheral blood, р=0,016). The EpCam+CK7-CD45-CD44+CD24-Snail-N-cadherin- and EpCam+CK7-CD45-CD44+CD24-Snail+N-cadherin- CTCs with intermediate epithelial-mesenchymal status were detected in 42.9% cases. The EpCam+CK7-CD45-CD44-CD24-Snail+N-cadherin- CTCs with intermediate epithelial-mesenchymal status were found in 57.1% cases. Stem-like CTCs mainly had the intermediate epithelial-mesenchymal status: EpCam+CK7+CD45-CD44+CD24-Snail+N-cadherin+, EpCam-CK7+CD45-CD44+CD24-Snail+N-cadherin+, EpCam-CK7+CD45-CD44+CD24-Snail-N-cadherin+ phenotypes were detected. EpCam+CK7+CD45-CD44+CD24-N-cadh-Snail+ CTCs with epithelial status were found in 28.6% cases. EpCam-CK7-CD45-CD44+CD24-Snail-N-cadherin+ CTCs with mesenchymal status were detected in 57.1% cases. Besides, CTCs with mesenchymal-epithelial transition (MET) were discovered in 42.9% cases.
Conclusions
Thus, the CTCs in breast cancer had different variants of EMT status and sometimes MET features. The stem-like CTCs were more diverse in EMT status. This work was supported by Russian Science Foundation (Grant No #19-75-30016).
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Russian Science Foundation (Grant No #19-75-30016).
Disclosure
All authors have declared no conflicts of interest.