Biology subjects

Gligorijevic, B.

Publications and source records attributed to Gligorijevic, B..

3 recordsLinked to original sources

bioRxiv2018

Invadopodia degrade ECM in the G1 phase of the cell cycle

Invadopodia are cancer cell protrusions rich in structural proteins (e.g. Tks5, cortactin) and proteases (e.g. MT1-MMP) and are responsible for degradation of the extracellular matrix (ECM). Tumor cell invasion and metastasis require cancer cells to be both proliferative and invasive, i.e. migrate through the tissue and assemble invadopodia. While several studies addressed how cell motility parameters change throughout the cell cycle, the relationship between invadopodia and cell cycle progression has not been elucidated. In this study, using invadopodia- and cell cycle- fluorescent markers, we show in 2D and 3D cell cultures, as well as in vivo, that breast carcinoma cells assemble invadopodia and invade into the surrounding ECM preferentially during the G1 phase of the cell cycle. Cells synchronized in the G0/G1 phase of the cell cycle degrade at significantly higher levels during the first 20 hours post-synchronization release. Consistent with this, mRNA and protein levels of the invadopodia key components, cortactin and MT1-MMP, peak at 14 hours post-release. Cell cycle progression is faster in cells in which invadopodia are abolished (by Tks5 knockdown), evidenced by earlier induction of cyclins A and B. A close look at the regulators of G1 revealed that the overexpression of p27kip1, but not p21cip1, causes faster turnover of invadopodia and increased ECM degradation. Furthermore, both endogenous and over-expressed p27kip1 localizes to the sites of invadopodia assembly. Taken together, these findings suggest that invadopodia function is tightly linked to cell cycle progression and is controlled by specific cell cycle regulators. Our results caution that this coordination between invasion and cell cycle must be considered when designing effective chemotherapies.

cancer biology↗

bioRxiv2018

Directed, but not random, breast cancer cell migration is faster in the G1 phase of the cell cycle in 2D and 3D environments

Cancer cell migration is essential for the early steps of metastasis, during which cancer cells move through the primary tumor and reach the blood vessels. In vivo, cancer cells are exposed to directional guidance cues, either soluble, such as gradients of growth factors, or insoluble, such as collagen fiber alignment. Depending on the number and strength of such cues, cells will migrate in a random or directed manner. Interestingly, similar cues also stimulate cell proliferation. In this regard, it is not clear whether cell cycle progression affects migration of cancer cells and whether this effect is different in random versus directed migration. In this study, we tested the effect of cell cycle progression on random and directed migration, both in 2D and 3D environments, in the breast carcinoma cell line, FUCCI-MDA-MB-231, using computational image analysis by LEVER. Directed migration in 2D was modeled as chemotaxis along a gradient of soluble EGF inside 10 {micro}m-wide microchannels. In 3D, directed migration was modeled as contact guidance (alignotaxis) along aligned collagen fibers. Time-lapse recordings of cells in 2D and 3D revealed that directed, but not random migration, is cell cycle-dependent. In both 2D and 3D directed migration, cells in the G1 phase of the cell cycle outperformed cells in the G2 phase in terms of migration persistence and instantaneous velocity. These data suggest that in the presence of guidance cues in vivo, breast carcinoma cells in the G1 phase of the cell cycle may be more efficient in reaching vasculature.

cancer biology↗

bioRxiv2017

ECM cross-linking regulates invadopodia dynamics

InvadopodiInvadopodia are membrane protrusions dynamically assembled by invasive cancer cells in contact with extracellular matrix (ECM). Invadopodia are enriched for the structural proteins actin and cortactin, as well as metalloproteases such as MT1-MMP, whose function is to degrade the surrounding ECM. During metastasis, invadopodia are necessary for cancer cell intravasation and extravasation. While signaling pathways involved in the assembly and function of invadopodia are well studied, few studies address invadopodia dynamics and how the cell-ECM interactions contribute to cell invasion. Using iterative analysis based on time-lapse microscopy and mathematical modeling of invasive cancer cells, we found that cells oscillate between invadopodia presence and cell stasis, termed Invadopodia state and invadopodia absence during cell translocation, termed Migration state. Our data suggests that {beta}1-integrin-ECM binding and ECM cross-linking control the duration of each of the two states. By changing the concentration of cross-linkers in 2D and 3D cultures, we generate ECM where 0-0.92 of total lysine residues are cross-linked. Using ECM with a range of cross-linking degrees we demonstrate that the dynamics of invadopodia-related functions have a biphasic relationship to ECM cross-linking. At intermediate levels of ECM cross-linking (0.39), cells exhibit rapid invadopodia protrusion-retraction cycles and rapid calcium spikes, which lead to more frequent MT1-MMP delivery, causing maximal invadopodia-mediated ECM degradation. In contrast, both extremely high or low levels of cross-linking lead to slower invadopodia-related dynamics and lower ECM degradation. Additionally, {beta}1-integrin inhibition modifies dynamics of invadopodia-related functions, as well as the length of time cells spend in either of the states. Collectively, these data suggest that {beta}1-integrin-ECM binding non-linearly translates small physical differences in extracellular environment to differences in the dynamics of cancer cell behaviors. Understanding conditions under which invadopodia can be reduced by subtle environment-targeting treatments may lead to combination therapies for preventing metastatic spread.

cancer biology↗