Leo - L4

EMT is the process by which epithelial cells acquire mesenchymal characteristics, enabling them to gain motility, which is vital for cancer invasiveness and metastasis.

Epithelial cells have cohesive interactions and a well-organized structure with tight junctions, while mesenchymal cells exhibit weak interactions, lack organization, and are not polarized.

Epithelial cells are tightly packed and linked by tight junctions, which restricts their mobility and maintains the integrity of tissue layers.

<p>During normal development, EMT facilitates the formation of various tissues and organs by allowing epithelial cells to migrate and differentiate into mesenchymal cells.</p> Signup and view all the answers

<p>Acquiring motility allows cancerous epithelial cells to detach from the primary tumor and migrate to distant sites, which is essential for metastasis.</p> Signup and view all the answers

<p>The lack of polarization in mesenchymal cells means they do not have clearly defined membrane domains, resulting in reduced structural organization and functionality.</p> Signup and view all the answers

<p>Tight junctions create strong adhesive interactions between epithelial cells, enabling them to form a continuous layer and preventing mobility.</p> Signup and view all the answers

<p>Mesenchymal cells do not adhere closely to one another and lack tight junctions, while epithelial cells adhere through E-cadherin and desmosomes.</p> Signup and view all the answers

<p>Vimentin is an intermediate filament highly expressed in mesenchymal cells, indicating their identity as opposed to epithelial cells, which express E-cadherin.</p> Signup and view all the answers

<p>EMT is significant as it allows epithelial cells to change their phenotype to a mesenchymal type, enhancing their motility and invasive capabilities.</p> Signup and view all the answers

<p>E-cadherin is critical for cell adhesion in epithelial cells but is reduced and sequestered inside vesicles in mesenchymal cells.</p> Signup and view all the answers

<p>Before EMT, epithelial cells undergo dissolution of their cell-to-cell junctions, which leads to reduced cellular adhesion and loss of apical-basal polarity.</p> Signup and view all the answers

<p>The main transcription factors are SNAIL and TWIST.</p> Signup and view all the answers

<p>The three polarity complexes are the Scribble complex, Crumbs complex, and Par complex.</p> Signup and view all the answers

<p>Genetic mutations can lead to an incorrect synthesis of E-cadherins, resulting in their defective function or degradation.</p> Signup and view all the answers

<p>Mesenchymal cells that undergo MET revert to an epithelial phenotype, restoring their adhesion and polarity.</p> Signup and view all the answers

<p>N-cadherin promotes cell-death resistance and enhances the invasiveness of cancer cells.</p> Signup and view all the answers

<p>Tight junctions are present and functional in epithelial cells providing strong adhesion, while they are absent in mesenchymal cells.</p> Signup and view all the answers

<p>VEGF and HGF promote EMT by inducing expression of SNAIL and increasing N-cadherin while decreasing E-cadherin.</p> Signup and view all the answers

<p>The basement membrane provides structural support and facilitates stable adhesion for epithelial cells, contributing to their organized layer.</p> Signup and view all the answers

<p>Hypermethylation and post transcriptional modifications can silence the E-cadherin gene.</p> Signup and view all the answers

<p>The decrease in E-cadherin is crucial as it reduces cell-cell adhesion, allowing epithelial cells to acquire motility and facilitating the EMT process.</p> Signup and view all the answers

<p>The decreased expression of E-cadherin leads to reduced interaction of the Scribble polarity complex with the plasma membrane, weakening cell adhesion.</p> Signup and view all the answers

<p>Epithelial cells transition to a more globular shape, resembling mesenchymal cells, enabling greater motility.</p> Signup and view all the answers

<p>EMT is essential for the differentiation and organization of specialized tissues and organ systems during embryonic development.</p> Signup and view all the answers

<p>EMT enhances cancer cell motility, enabling malignant cells to detach, migrate, and form metastases in secondary locations.</p> Signup and view all the answers

<p>MET stands for mesenchymal to epithelial transition; it is a reversible process allowing mesenchymal cells to regain epithelial traits.</p> Signup and view all the answers

<p>EMT is involved in neural crest formation, heart morphogenesis, and wound healing.</p> Signup and view all the answers

<p>Increased expression of alternative cadherins like N-cadherin helps in the transition to mesenchymal phenotypes during EMT.</p> Signup and view all the answers

<p>Cancer cells activate differentiation genes, reduce proliferation, and engage anti-apoptotic mechanisms to enable migration.</p> Signup and view all the answers

<p>In pathological conditions, EMT contributes to fibrosis and cancer progression, particularly in epithelial tumors, by promoting cell motility.</p> Signup and view all the answers

<p>Down-regulating receptors reduces cell-to-cell interactions, facilitating the dissolution of tight junctions necessary for cell migration.</p> Signup and view all the answers

<p>This phenotypic change allows cancer cells to acquire greater motility and invasiveness, essential for metastasis.</p> Signup and view all the answers

<p>Activating proteases enables degradation of the extracellular matrix, which is necessary for cancer cells to migrate and invade new areas.</p> Signup and view all the answers

<p>Pathological EMT occurs in an irregular and time-independent manner, lacking the tight spatial and temporal regulation seen in physiological EMT.</p> Signup and view all the answers

<p>Tumor heterogeneity leads to varying responses among different cell populations, resulting in asynchronous EMT and metastasis capabilities.</p> Signup and view all the answers

<p>Both genetic and epigenetic changes are necessary for EMT, as genetic changes provide irreversible mutations while epigenetic changes modulate gene expression in a reversible manner.</p> Signup and view all the answers

<p>Reducing proliferation facilitates the transition to a motile mesenchymal phenotype, allowing cells to migrate and invade effectively.</p> Signup and view all the answers

<p>Oncogenic pathways driven by growth factors and molecules may alter the sequence and timing of events in EMT, leading to bypassing regulatory checkpoints.</p> Signup and view all the answers

<p>Cells lose their organized apico-basal polarity and adopt a more irregular shape, enhancing their ability to invade and migrate.</p> Signup and view all the answers

<p>Metalloproteins degrade components of the extracellular matrix, enabling cancer cells to pass through and migrate more freely.</p> Signup and view all the answers