Multicellular organization requires rapid changes in biomechanical dynamics and establishment of a collective actomyosin network in order to maintain cell morphology. How human embryonic stem cells (hESCs) orchestrate cytoskeletal tension across cells and organize adhesion complexes to maintain cytoarchitectural integrity is incompletely understood. Recent work by the Friedel lab identified a key role for Plexin-B2 in the control of actomyosin contractility and adhesion properties in hESCs. Plexin-B2 is an axon guidance receptor that has been shown to mediate cellular interactions in a variety of tissue contexts. The group utilized Plexin-B2 CRISPR KO hESCS (B2-KO) as well as lentiviral Plexin-B2 overexpressing hESCs [B2-OE] to show that dysregulation of Plexin-B2 severely alters hESC colony expansion and ...

January 2022

Mechanical actions of dendritic-spine enlargement on presynaptic exocytosis

December 2021

Ral GTPases promote breast cancer metastasis by controlling biogenesis and organ targeting of exosomes

Communication between neurons in the brain is generally associated with electrochemical signaling. Haruo Kasai’s laboratory discovered that dendritic spines could be stimulated to enlarge rapidly, which at the time they hypothesized could result in pressing against the presynaptic boutons in the synaptic junction and elicit an effect; however, at the time the tools to effectively investigate this phenomenon wasn’t available. In this recent study, the group validated their theory that physical forces elicited by dendritic spine enlargement ...

Read More

Metastasis is a fundamental hallmark of cancer and the most closely aligned with poor prognosis. The mechanisms that regulate metastasis; in particular, the cancer cell’s ability to communicate with the tumor microenvironment to colonize at distinct, distal organ sites remain an intense area of investigation. Recent studies suggest both soluble molecules as well as extracellular vesicles (EV) can play important roles towards seeding the pre-metastatic niche and creating a favorable tumor microenvironment for metastatic cancer cells. Preliminary work by Hyenne et al. identified Ral A/B as a participant in EV secretion in aggressive 4T1 mammary tumor cells; however, whether these EVs play a role in metastasis remained unknown......

Read More