Biology subjects

Wong, B. S.

Publications and source records attributed to Wong, B. S..

3 recordsLinked to original sources

bioRxiv2025

p53 preserves genome stability in dividing cells under hypo-osmotic stress

Cells respond to frequent osmotic stress to maintain structural integrity and function. Whereas acute volume regulation is well-known, the cellular response to prolonged osmotic stress and its long-term consequences remain poorly understood. In this study, we investigate how lasting hypo-osmotic stress influences cell growth and division and the associated cellular response. We observe that cells undergoing their first division under hypo-osmotic stress experience delayed mitotic entry, lengthened mitotic duration, elevated mitotic errors and aneuploidy formation. However, continued cell division is halted through a p53/p21-dependent G1 arrest. p53 activation occurs post-mitotically and is associated with hyper-condensed chromatin and impaired nuclear expansion in daughter cells after mitotic exit. We show that the altered nuclear size dynamics lead to nuclear accumulation of p53 and activation of downstream gene expression. These findings uncover a mechanosensitive, p53-mediated mechanism that safeguards genome integrity by suppressing erroneous mitosis under hypo-osmotic stress.

cell biology↗

bioRxiv2025

Label-Free Longitudinal Imaging of Single Cell Drug Response with a 3D-Printed Cell Culture Platform

Image-based phenotypic screening has emerged as a powerful tool for revealing single-cell heterogeneity and dynamic phenotypic responses in preclinical drug discovery. Compared to traditional static end-point assays, live-cell longitudinal imaging captures the temporal trajectories of individual cells, including transient morphological adaptations, motility shifts, and divergent subpopulation behaviors, enabling high content features and more robust early prediction of treatment outcomes. Fluorescence-based screening, while highly specific, is constrained in live-cell contexts by broad spectral overlaps (limiting multiplexing to fewer than six channels), bulky fluorophores that may perturb small-molecule interactions, and photobleaching or phototoxicity under repeated excitation. Stimulated Raman scattering (SRS) microscopy overcomes these barriers by delivering label-free, quantitative chemical contrasts alongside morphological information. Here, we present a low-cost, 3D printed cell culture platform compatible with the stringent optical requirements of SRS microscopy. This set up enables real-time drug delivery and continuous monitoring of biochemical and morphological changes in living cells during 24-hour time-lapse imaging with minimal photodamage. We outline a processing pipeline for longitudinal SRS images to extract chemical and morphological features of single live cells. Using this system, we showcase time-lapse SRS microscopy as a tool to map heterogenous drug-induced single-cell response over time, enabling the identification of varying trajectories within complex cell populations. By parallelizing multi-well perfusion with label-free chemical imaging, our approach offers a pathway toward high-throughput pharmacodynamic assays for the acceleration of phenotypic screening and personalized medicine.

bioengineering↗

bioRxiv2019

Post-EMT: Cadherin-11 mediates cancer hijacking fibroblasts

Current prevailing knowledge on EMT (epithelial mesenchymal transition) deems epithelial cells acquire the characters of mesenchymal cells to be capable of invading and metastasizing on their own. One of the signature events of EMT is called "cadherin switch", e.g. the epithelial E-cadherin switching to the mesenchymal Cadherin-11. Here, we report the critical events after EMT that cancer cells utilize cadherin-11 to hijack the endogenous cadherin-11 positive fibroblasts. Numerous 3-D cell invasion assays with high-content live cell imaging methods reveal that cadherin-11 positive cancer cells adhere to and migrate back and forth dynamically on the cell bodies of fibroblasts. By adhering to fibroblasts for co-invasion through 3-D matrices, cancer cells acquire higher invasion speed and velocity, as well as significantly elevated invasion persistence, which are exclusive characteristics of fibroblast invasion. Silencing cadherin-11 in cancer cells or in fibroblasts, or in both, significantly decouples such physical co-invasion. Additional bioinformatics studies and PDX (patient derived xenograft) studies link such cadherin-11 mediated cancer hijacking fibroblasts to the clinical cancer progression in human such as triple-negative breast cancer patients. Further animal studies confirm cadherin-11 mediates cancer hijacking fibroblasts in vivo and promotes significant solid tumor progression and distant metastasis. Moreover, overexpression of cadherin-11 strikingly protects 4T1-luc cells from implant rejection against firefly luciferase in immunocompetent mice. Overall, our findings report and characterize the critical post-EMT event of cancer hijacking fibroblasts in cancer progression and suggest cadherin-11 can be a therapeutic target for solid tumors with stroma. Our studies hence provide significant updates on the "EMT" theory that EMT cancer cells can hijack fibroblasts to achieve full mesenchymal behaviors in vivo for efficient homing, growth, metastasis and evasion of immune surveillance. Our studies also reveal that cadherin-11 is the key molecule that helps link cancer cells to stromal fibroblasts in the "Seed & Soil" theory. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=117 SRC="FIGDIR/small/729491v2_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@11317f1org.highwire.dtl.DTLVardef@88fffaorg.highwire.dtl.DTLVardef@5da692org.highwire.dtl.DTLVardef@62f6ed_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗