Advances in cell nuclear mechanobiology and its regulation mechanisms / 生物医学工程学杂志

As an important intracellular genetic and regulatory center, the nucleus is not only a terminal effector of intracellular biochemical signals, but also has a significant impact on cell function and phenotype through direct or indirect regulation of nuclear mechanistic cues after the cell senses and responds to mechanical stimuli. The nucleus relies on chromatin-nuclear membrane-cytoskeleton infrastructure to couple signal transduction, and responds to these mechanical stimuli in the intracellular and extracellular physical microenvironments. Changes in the morphological structure of the nucleus are the most intuitive manifestation of this mechanical response cascades and are the basis for the direct response of the nucleus to mechanical stimuli. Based on such relationships of the nucleus with cell behavior and phenotype, abnormal nuclear morphological changes are widely used in clinical practice as disease diagnostic tools. This review article highlights the latest advances in how nuclear morphology responds and adapts to mechanical stimuli. Additionally, this article will shed light on the factors that mechanically regulate nuclear morphology as well as the tumor physio-pathological processes involved in nuclear morphology and the underlying mechanobiological mechanisms. It provides new insights into the mechanisms that nuclear mechanics regulates disease development and its use as a potential target for diagnosis and treatment.

Matrix Stiffness Regulates Drug Resistance of Breast Cancer Cells Through YAP Activation / 医用生物力学

Objective To investigate the detailed molecular mechanism of matrix stiffness regulating cell drug resistance. Methods Polyacrylamide hydrogels of soft substrate (10 kPa), hard substrate (38 kPa) and rigid substrate (57 kPa) with different matrix stiffness were configured to simulate the physical matrix stiffness at different stages of breast cancer in vivo. Results The cell proliferation rate of the hard substrate was significantly higher than that of the soft and rigid substrates. The intracellular endocytosis was significantly lower on the hard substrate. The YAP nucleus translocation increased significantly on the hard substrate, compared with the soft and the rigid substrates, indicating that YAP was a key molecule involved in drug resistance of tumor cells. Conclusions Matrix stiffness could regulate the drug resistance of breast cancer cells through YAP activation. This study not only provides a new direction for elucidating the mechanism of drug resistance, but also lays a new foundation for the drug delivery system of breast cancer treatment.