Flaxseed has been recognized as a valuable source of nutrients and bioactive compounds, including proteins that possess various health benefits. In recent years, studies have shown that flaxseed proteins, including albumins, globulins, glutelin, and prolamins, possess anti-cancer properties. These properties are attributed to their ability to inhibit cancer cell proliferation, induce apoptosis, and interfere with cancer cell signaling pathways, ultimately leading to the inhibition of metastasis. Moreover, flaxseed proteins have been reported to modulate cancer cell mechanobiology, leading to changes in cell behavior and reduced cancer cell migration and invasion. This review provides an overview of the anti-cancer properties of flaxseed proteins, with a focus on their potential use in cancer treatment. Additionally, it highlights the need for further research to fully establish the potential of flaxseed proteins in cancer therapy.

Flaxseed has been recognized as a valuable source of nutrients and bioactive compounds, including proteins that possess various health benefits. In recent years, studies have shown that flaxseed proteins, including albumins, globulins, glutelin, and prolamins, possess anti-cancer properties. These properties are attributed to their ability to inhibit cancer cell proliferation, induce apoptosis, and interfere with cancer cell signaling pathways, ultimately leading to the inhibition of metastasis. Moreover, flaxseed proteins have been reported to modulate cancer cell mechanobiology, leading to changes in cell behavior and reduced cancer cell migration and invasion. This review provides an overview of the anti-cancer properties of flaxseed proteins, with a focus on their potential use in cancer treatment. Additionally, it highlights the need for further research to fully establish the potential of flaxseed proteins in cancer therapy.

PURPOSE: In 2020, there were 2.3 million women diagnosed with breast cancer. Deaths related to cancer occur due to metastasis. In most types of solid tumors, spreading happens through collective migration, guided by “cellular leaders.” Previously, we have shown that 100-200 nm nanoparticles encapsulated more efficiently by cells with high metastatic potential (MP) than by cells with low MP. The aim of the current research is to quantitatively compare the encapsulation ability between metastatic cells that act as leaders during migration, and peripheral cells. METHODS: We used Wound Healing Assay to study collective migration in two cell lines: MCF7 and MDA-MB-231 (low and high MP respectively). Firstly, we conducted calibration experiments to find the “optimal time”, when the cells reach the maximal speed during wound closure. Further, the cells were incubated with 200nm fluorescent nanoparticles for one hour prior to the determined “optimal time”. Digital images were acquired using fluorescent microscopy and Fiji software. Colocalization of nanoparticles was calculated using Pearson coefficient. Statistical differences were performed using ANOVA. RESULTS: The highest wound closure rate for low MP cells was reached in 2.6 hours and for high MP cells in 3.9 (8 and 11% of wound area closure respectively). The coefficients of nanoparticle encapsulation were 0.063±0.005 and 0.046±0.004 at the edge of the wound and at peripheral area, respectively, for cells with high MP 0.039±0.003 and 0.027±0.002 for low MP. We observed a significant difference in encapsulation efficiency between leading and peripheral cells for both, high and low MP cells (p<0.013). CONCLUSION: We have found the “optimal time” of wound closure, with the increased migration activity for each tested cell type. We have demonstrated that encapsulation efficiency of leading cells is significantly higher than for peripheral cells. Therefore, nanoparticles encapsulation can be used as a potential marker for most aggressive and invasive, leading cells in collective migration of breast cancer cells.

Cancer-related deaths primarily occur due to metastasis, a process involving the migration and invasion of cancer cells. In most solid tumors, metastasis occurs through collective cell migration (CCM), guided by “cellular leaders”. These leader cells generate forces through actomyosin-mediated protrusion and contractility. The cytoskeletal mechanisms employed by metastatic cells during the migration process closely resemble the use of the actin cytoskeleton in endocytosis. In our previous work, we revealed that tumor cells exhibiting high metastatic potential (MP) are more adept at encapsulating 100–200 nm nanoparticles than those with lower MP. The objective of this study was to investigate whether nanoparticle encapsulation could effectively differentiate leader tumor cells during their CCM. To achieve our objectives, we employed a two-dimensional CCM model grounded in the wound-healing (“scratch”) assay, utilizing two breast cancer cell lines, MCF7 and MDA-MB-231, which display low and high migratory potential, respectively. We conducted calibration experiments to identify the “optimal time” at which cells exhibit peak speed during wound closure. Furthermore, we carried out experiments to assess nanoparticle uptake, calculating the colocalization coefficient, and employed phalloidin staining to analyze the anisotropy and orientation of actin filaments. The highest activity for low-MP cells was achieved at 2.6 h during the calibration experiments, whereas high-MP cells were maximally active at 3.9 h, resulting in 8% and 11% reductions in wound area, respectively. We observed a significant difference in encapsulation efficiency between leader and peripheral cells for both high-MP (p < 0.013) and low-MP (p < 0.02) cells. Moreover, leader cells demonstrated a considerably higher anisotropy coefficient (p < 0.029), indicating a more organized, directional structure of actin filaments compared to peripheral cells. Thus, nanoparticle encapsulation offers a groundbreaking approach to identifying the most aggressive and invasive leader cells during the CCM process in breast cancer. Detecting these cells is crucial for developing targeted therapies that can effectively curb metastasis and improve patient outcomes.

Hypoxia is a key microenvironmental factor shaping tumor cell survival and plasticity, but its cellular consequences depend on the cancer subtype. Here, we compare breast cancer cell lines with varying metastatic potential (MP) in response to CoCl₂-induced hypoxia (100 μM, 20 h), analyzing the results immediately (T0) and after 24 h (T1). Plasma membrane damage was measured by the number of propidium iodide-positive cells. Hypoxia pathway activation was evaluated using HIF-1α immunofluorescence, while phenotypic changes were assessed through quantitative morphometric analysis. Chemically induced hypoxia promoted a delayed increase in membrane failure in low-MP cells, consistent with reduced tolerance to hypoxia-mimetic stress. In contrast, high-MP cultures showed a lower PI-positive fraction at T1, consistent with enhanced survival under these conditions. This divergence was accompanied by higher basal and hypoxia-induced HIF-1α levels in high-MP cells. High-MP cells uniquely demonstrated delayed shape changes after exposure to hypoxia-mimetic conditions, evolving into a more compact and rounded form, suggesting phenotypic plasticity instead of structural deterioration. Together, our findings provide insight into how oxygen deprivation impacts cell destiny and phenotypic plasticity in breast cancer models with varying metastatic risks.