Paris polyphylla ethanol extract induces G2/M arrest and suppresses migration and invasion in bladder cancer
TRANSLATIONAL CANCER RESEARCH
Authors: Liu, Zhiyong; Sun, Zhonghua; Zhang, Denglu; Ma, Chenchen; Jiang, Yuehua; Cao, Guangshang; Sun, Chao; Li, Kailin; Xu, Dawei; Liu, Jiang; Zhao, Shengtian
Background: Paris polypbylla is a traditional Chinese medicinal herb with multiple antitumor activities, but the role of P. polyphylla in bladder cancer (BC) is under investigation. This study aims to examine the antitumor activities of P. polyphylla ethanol extract (PPE) on BC cells and elucidate the underlying mechanisms. Methods: Viable cells were counted using the trypan blue exclusion assay. The cell cycle was analyzed using flow cytometry, and scratch wound-healing and transwell assays were used to evaluate cell migration and invasion abilities, respectively. The protein expression levels were determined by western blotting. A xenograft model was used to assess the in vivo inhibitory effect of PPE on BC tumor growth. Results: Our results showed that PPE inhibited the growth of BC cells in vivo and in vitro. Mechanistically, PPE regulated the levels of cell cycle-associated proteins, with PPE-induced G2/M phase arrest occurring through cyclin-dependent kinase inhibitor 1(CDKN1A) accumulation and cyclin B1 (CCNB1)/cyclindependent kinase 1 (CDK1) inhibition. BC tumor growth was also inhibited by PPE treatment. Moreover, the migration and invasion abilities of J82 cells were suppressed through modulating epithelial-mesenchymal transition (EMT) regulatory factors with upregulation of cadherin-1 (CDH1) and downregulation of cadherin-2 (CDH2), snail family transcriptional repressor 2 (SNAI2), and twist family bHLH transcription factor 1 (TWIST1). Conclusions: PPE inhibited cell growth, induced G2/M arrest, and suppressed the migration and invasion of J82 cells. BC tumor growth in vivo was also inhibited by PPE. Our results lay the foundation for further studies on the antitumor mechanisms of PPE.
Connections between the cell cycle, cell adhesion and the cytoskeleton
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
Authors: Jones, Matthew C.; Zha, Junzhe; Humphries, Martin J.
Cell division, the purpose of which is to enable cell replication, and in particular to distribute complete, accurate copies of genetic material to daughter cells, is essential for the propagation of life. At a morphological level, division not only necessitates duplication of cellular structures, but it also relies on polar segregation of this material followed by physical scission of the parent cell. For these fundamental changes in cell shape and positioning to be achieved, mechanisms are required to link the cell cycle to the modulation of cytoarchitecture. Outside of mitosis, the three main cytoskeletal networks not only endow cells with a physical cytoplasmic skeleton, but they also provide a mechanism for spatio-temporal sensing via integrin-associated adhesion complexes and site-directed delivery of cargoes. During mitosis, some interphase functions are retained, but the architecture of the cytoskeleton changes dramatically, and there is a need to generate a mitotic spindle for chromosome segregation. An economical solution is to re-use existing cytoskeletal molecules: transcellular actin stress fibres remodel to create a rigid cortex and a cytokinetic furrow, while unipolar radial microtubules become the primary components of the bipolar spindle. This remodelling implies the existence of specific mechanisms that link the cell-cycle machinery to the control of adhesion and the cytoskeleton. In this article, we review the intimate three-way connection between microenvironmental sensing, adhesion signalling and cell proliferation, particularly in the contexts of normal growth control and aberrant tumour progression. As the morphological changes that occur during mitosis are ancient, the mechanisms linking the cell cycle to the cytoskeleton/adhesion signalling network are likely to be primordial in nature and we discuss recent advances that have elucidated elements of this link. A particular focus is the connection between CDK1 and cell adhesion.