Quantitative investigation of MDA-MB-231 breast cancer cell motility: dependence on epidermal growth factor concentration and its gradient

Abstract

Enhanced cell motility is one of the primary features of cancer. Accumulated evidence demonstrates that Epidermal Growth Factor Receptor (EGFR) mediated pathways play an important role in breast cancer cell proliferation and migration. We have quantified the MDA-MB-231 breast cancer cell migration in response to the stimulation of EGFR pathways with its ligand EGF to determine how cell motility of MDA-MB-231 cells depend on the ligand concentration and its gradient. Analysis at the single cell level combined with mathematical modeling and the ability to vary the ligand concentration and gradients locally using microfluidic devices allowed us to separate the unique contributions of ligand concentration and ligand gradients to cell motility. We tracked the motility of 6,600 cells individually using time lapse imaging under varying EGF stimulation conditions. Trajectory analysis of the tracked cells using non-linear multivariate regression models showed that: i) Cell migration of MDA-MB-231 breast cancer cells depends on ligand gradient but not on the ligand concentration. This observation was valid for both the total (direction independent) and directed (along gradient direction) cell velocities. Although the dependence of the directed motility on ligand gradient is to be expected, dependence of the total velocity solely on ligand gradient was an unexpected novel observation. ii) Enhancement of motilities of individual cells in a population upon exposure to ligand was highly heterogeneous, and only a very small percentage of cells responded strongly to the external stimuli. Separating out the non-responding cells using quantitative analysis of individual cell motilities enabled us to establish that enhanced motility of the responding cells indeed increases monotonically with increasing EGF gradient. iii) A large proportion of cells in a population were unresponsive to ligand stimulation, and their presence introduced considerable random intrinsic variability to the observations. This indicated that studying cell motilities at individual cell level is necessary to better capture the biological reality and that population averaging methods should be avoided. Studying motilities at individual cell level is particularly important to understand the biological processes which are possibly driven by the action of a small portion of cells in a population, such as metastasis. We discuss the implications of our results on the total and chemotactic movement of cancer cells in the tumor microenvironment.

Triple Negative Breast Cancer-derived Small Extracellular Vesicles as Modulator of Biomechanics in target cells

“…Cell proliferation assay was first performed on MCF7 and MDA-MB-231 cells, confirming the higher proliferation of the latter, in agreement with the literature (Figure 2a) (Gest et al, 2013; H. et al, 2011; Islam & Resat, 2017). The activity and functionality of the isolated 231_sEVs were evaluated by verifying differences in MCF7 cell proliferation upon the addition of 231_sEVs.…”

“…To test such assumption, we examined the effects of small EVs derived from the TNBC MDA-MB-231 breast cancer cells on the stiffness, cytoskeleton organization, nuclear/cellular morphology, and Yap activity of the Luminal A MCF7 breast cancer cells. The two cell lines have been chosen according to their different well-defined metastatic potential: MDA-MB-231 cells are characterized by high proliferation, motility, and metastatic rate (Islam & Resat, 2017), whereas MCF7 cells are tumorigenic but have low/absent metastatic potential (Gest et al, 2013;H. et al, 2011).…”

Heterogeneous nuclear ribonucleoprotein A2/B1 is a negative regulator of human breast cancer metastasis by maintaining the balance of multiple genes and pathways

“…4A). The induction of EGF on cell migration and invasion was confirmed by previous studies [27,28]. We also evaluated the role of EGF in our research system.…”

Long noncoding RNA TSLNC8 suppresses cell proliferation and metastasis and promotes cell apoptosis in human glioma

“…The results of the present study suggested that TSLNC8 was downregulated in human glioma, which was associated with increased cell proliferative rate and cell metastasis, as well as the decreased cell apoptotic capacity in human glioma cell lines; TSLNC8 may be a potential therapeutic target for cancer patients in clinic. Cell proliferation and cell metastasis are two primary manifestations in the majority of malignancies (24,25). Initiation of metastasis requires invasion, which was examined in the present study via Transwell and wound-healing assays.…”