Heterogeneity of ERα and ErbB2 Status in Cell Lines and Circulating Tumor Cells of Metastatic Breast Cancer Patients

Abstract

Hormone therapy and anti-ErbB2 therapies are prescribed according to the hormone receptor [estrogen receptor α (ERα)/progesterone receptor] and ErbB2 status of the initial tumor, but it appears that circulating tumor cells (CTCs) and, consequently, the metastatic cells may have a different receptor status. As an attempt to meet the crucial need for identification of the subpopulation of patients that will benefit from more individualized therapies, rapidly evolving therapies should allow a profiling of the tumors and/or of the CTCs. We established a triple fluorescence staining using eight cell lines to visualize the CTCs (cytokeratin detection) and then to define their individual ERα and ErbB2 status. Afterward, we used this method for blood samples from 26 metastatic breast cancer patients. We identified major differences of ERα levels between the cell lines and even within one cell line. For the metastatic patients, we detected and characterized CTCs in 38.5% of the patients with a total of 92 CTCs. We could demonstrate that at least 69.6% of the CTCs exhibit an ERα and/or ErbB2 status different from the status of the primary tumor and that the CTCs from only 30% of the patients had no change of receptor status. Strikingly, heterogeneities of the status, aggregation, and size clearly appear within the CTCs. The data we generated outline the importance of a profiling not only of tumors but also of CTCs to establish individualized treatments. CTCs may then appear as new prognosis and treatment marker for both metastatic and adjuvant breast cancers.

Heterogeneity of Estrogen Receptor Expression in Circulating Tumor Cells from Metastatic Breast Cancer Patients

“…These challenges had to be taken into consideration: the complications of nuclei permeabilization for antibody delivery, low level of ER presence, difficulties in unequivocal identification of CTCs in case of CD45+/K+ cells presence. A recent study by Bock and colleagues showed a higher percentage of ER-negative CTCs, however, the sample size of CTC positive metastatic breast cancer patients was relatively low (n = 5) [48]. In the study of Nadal et al , in contrast to our study, only non-metastatic breast cancer patients before any systemic treatment were enrolled and volume of 30 ml blood per patient was analyzed.…”

“…This might be explained by the low correlation of mRNA and protein expression of ER [46]. To our knowledge, only two studies have been performed in which the authors have stained ER on single CTCs using ICC [47], [48]. Limited number of studies, based on ICC for the investigation of CTCs, might be explained by the technical challenges.…”

Fluorescence Analysis of Vitamin D Receptor Status of Circulating Tumor Cells (CTCS) in Breast Cancer: From Cell Models to Metastatic Patients

“…We previously used various human carcinoma cell lines to develop a simple and efficient triple fluorescence technique for CTC receptor analysis, e.g., ER, HER2 [15], N -cadherin, and CD133 [26]. We tested the VDR expression in nine BC cell lines and CTCs from 23 archived metastatic BC cases.…”

“…CTCs detected in BC patients are significantly associated with a poor outcome in both early and metastatic tumors [15,16,17,18,19]. In metastatic patients, several tumor lesions may potentially release CTCs which therefore comprehensively reflect tumor and metastasis characteristics.…”

Cellules tumorales circulantes : pierre angulaire de la médecine personnalisée

“…Cette différence phénotypique a également été décrite pour les récepteurs hormonaux. Dans une étude, seulement 14 % des patientes avec une tumeur RH+ avaient des DTCs négatifs pour les RH [14,51,52].…”