Cellular Shape Changes Research Articles

The nucleus measures shape changes for cellular proprioception to control dynamic cell behavior.

The physical microenvironment regulates cell behavior during tissue development and homeostasis. How single cells decode information about their geometrical shape under mechanical stress and physical space constraints within tissues remains largely unknown. Here, using a zebrafish model, we show that the nucleus, the biggest cellular organelle, functions as an elastic deformation gauge that enables cells to measure cell shape deformations. Inner nuclear membrane unfolding upon nucleus stretching provides physical information on cellular shape changes and adaptively activates a calcium-dependent mechanotransduction pathway, controlling actomyosin contractility and migration plasticity. Our data support that the nucleus establishes a functional module for cellular proprioception that enables cells to sense shape variations for adapting cellular behavior to their microenvironment.

Reconfiguring DNA Nanotube Architectures via Selective Regulation of Terminating Structures.

Molecular assemblies inside cells often undergo structural reconfiguration in response to stimuli to alter their function. Adaptive reconfiguration of cytoskeletal networks, for example, enables cellular shape change, movement, and cargo transport and plays a key role in driving complex processes such as division and differentiation. The cellular cytoskeleton is a self-assembling polymer network composed of simple filaments, so reconfiguration often occurs through the rearrangement of its component filaments' connectivities. DNA nanotubes have emerged as promising building blocks for constructing programmable synthetic analogs of cytoskeletal networks. Nucleating seeds can control when and where nanotubes grow, and capping structures can bind nanotube ends to stop growth. Such seeding and capping structures, collectively called termini, can organize nanotubes into larger architectures. However, these structures cannot be selectively activated or inactivated in response to specific stimuli to rearrange nanotube architectures, a key property of cytoskeletal networks. Here, we demonstrate how selective regulation of the binding affinity of DNA nanotube termini for DNA nanotube monomers or nanotube ends can direct the reconfiguration of nanotube architectures. Using DNA hybridization and strand displacement reactions that specifically activate or inactivate four orthogonal nanotube termini, we demonstrate that nanotube architectures can be reconfigured by selective addition or removal of distinct termini. Finally, we show how terminus activation could be a sensitive detector and amplifier of a DNA sequence signal. These results could enable the development of adaptive and multifunctional materials or diagnostic tools.

Pharmacologic dissection of the overlapping impact of heat shock protein family members on platelet function

BackgroundPlatelets play a pivotal role in hemostasis, wound healing, and inflammation, and are thus implicated in a variety of diseases, including cancer. Platelet function is associated with release of granule content, cellular shape change, and upregulation of receptors that promote establishment of a thrombus and maintenance of hemostasis. ObjectivesThe role of heat shock proteins (Hsps) in modulating platelet function has been studied for a number of years, but comparative roles of individual Hsps have not been thoroughly examined. MethodsWe utilized a panel of specific inhibitors of Hsp40, Hsp70, Hsp90, and Grp94 (the endoplasmic reticulum homolog of Hsp90) to assess their impact on several aspects of platelet function. ResultsInhibition of each of the aforementioned Hsps reduced alpha granule release. In contrast, there was some selectivity in impacts on dense granule release. Thromboxane synthesis was impaired after exposure to inhibitors of Hsp40, Hsp90, and Grp94, but not after inhibition of Hsp70. Both expression of active glycoprotein IIb/IIIa (GPIIb/IIIa) and fibrinogen‐induced platelet shape change were diminished by our inhibitors. In contrast, aggregation was selectively abrogated after inhibition of Hsp40 or Hsp90. Lastly, activated platelet–cancer cell interactions were reduced by inhibition of both Hsp70 and Grp94. ConclusionsThese data suggest the importance of Hsp networks in regulating platelet activity.

Mathematical modelling in cell migration: tackling biochemistry in changing geometries.

Directed cell migration poses a rich set of theoretical challenges. Broadly, these are concerned with (1) how cells sense external signal gradients and adapt; (2) how actin polymerisation is localised to drive the leading cell edge and Myosin-II molecular motors retract the cell rear; and (3) how the combined action of cellular forces and cell adhesion results in cell shape changes and net migration. Reaction-diffusion models for biological pattern formation going back to Turing have long been used to explain generic principles of gradient sensing and cell polarisation in simple, static geometries like a circle. In this minireview, we focus on recent research which aims at coupling the biochemistry with cellular mechanics and modelling cell shape changes. In particular, we want to contrast two principal modelling approaches: (1) interface tracking where the cell membrane, interfacing cell interior and exterior, is explicitly represented by a set of moving points in 2D or 3D space and (2) interface capturing. In interface capturing, the membrane is implicitly modelled analogously to a level line in a hilly landscape whose topology changes according to forces acting on the membrane. With the increased availability of high-quality 3D microscopy data of complex cell shapes, such methods will become increasingly important in data-driven, image-based modelling to better understand the mechanochemistry underpinning cell motion.

The Urothelium: Life in a Liquid Environment.

The urothelium, which lines the renal pelvis, ureters, urinary bladder, and proximal urethra, forms a high-resistance but adaptable barrier that surveils its mechanochemical environment and communicates changes to underlying tissues including afferent nerve fibers and the smooth muscle. The goal of this review is to summarize new insights into urothelial biology and function that have occurred in the past decade. After familiarizing the reader with key aspects of urothelial histology, we describe new insights into urothelial development and regeneration. This is followed by an extended discussion of urothelial barrier function, including information about the roles of the glycocalyx, ion and water transport, tight junctions, and the cellular and tissue shape changes and other adaptations that accompany expansion and contraction of the lower urinary tract. We also explore evidence that the urothelium can alter the water and solute composition of urine during normal physiology and in response to overdistension. We complete the review by providing an overview of our current knowledge about the urothelial environment, discussing the sensor and transducer functions of the urothelium, exploring the role of circadian rhythms in urothelial gene expression, and describing novel research tools that are likely to further advance our understanding of urothelial biology.

Dynamic Real-Time Deformability Cytometry - Time-Resolved Mechanical Single Cell Analysis at 100 Cells/s

In life sciences, the material properties of suspended cells have attained significance close to that of fluorescent markers but with the advantage of label-free and unbiased sample characterization. Until recently, cell rheological measurements were either limited by acquisition throughput, excessive post processing, or low-throughput real-time analysis. Real-time deformability cytometry, a label-free technique for single cell mechanical analysis with high-throughput of up to 1,000 cells / second, expanded the application of mechanical cell assays to fast on-the-fly phenotyping of large sample sizes, but has been restricted to single material parameters as the Young's modulus. Dynamic RT-DC (dRT-DC) overcomes this limitation and is capable to capture full viscoelastic properties of up to 100 suspended cells / second. Cellular shape-changes along the entire length of the microfluidic channel are tracked in real-time and are subsequently analyzed by a Fourier decomposition. We demonstrate that this approach allows to disentangle cell response to the complex hydrodynamic environment at the inlet from the steady-state stress distribution inside the channel. A superposition of both effects is present in almost all microfluidic systems and potentially biases label-free cytometric measurements relying on steady-state flow conditions. Dynamic RT-DC was performed on a precursor myeloid cell line HL60 as well as on primary blood cells. We show for the cell line that our method is capable to monitor changes in the apparent Young's modulus and viscosity after actin depolymerization. We use these findings for a first rheological comparison between erythrocytes, granulocytes and peripheral blood mononucleated cells (PBMCs) in a single experimental assay. We demonstrate that granulocytes and PBMCs have a significantly increased Young's modulus as well as viscosity compared to red blood cells and that our method is capable of a label-free discrimination of B- and CD4+ T-lymphocytes.

Kinetic Analysis of the Motility of Giant Virus-Infected Amoebae Using Phase-Contrast Microscopic Images.

Tracking cell motility is a useful tool for the study of cell physiology and microbiology. Although phase-contrast microscopy is commonly used, the existence of optical artifacts called “halo” and “shade-off” have inhibited image analysis of moving cells. Here we show kinetic image analysis of Acanthamoeba motility using a newly developed computer program named “Phase-contrast-based Kinetic Analysis Algorithm for Amoebae (PKA3),” which revealed giant-virus-infected amoebae-specific motilities and aggregation profiles using time-lapse phase-contrast microscopic images. This program quantitatively detected the time-dependent, sequential changes in cellular number, size, shape, and direction and distance of cell motility. This method expands the potential of kinetic analysis of cultured cells using versatile phase-contrast images. Furthermore, this program could be a useful tool for investigating detailed kinetic mechanisms of cell motility, not only in virus-infected amoebae but also in other cells, including cancer cells, immune response cells, and neurons.

Insights into the molecular basis of immunosuppression and increasing pathogen infection severity of ammonia toxicity by transcriptome analysis in pacific white shrimp Litopenaeus vannamei

The high concentration of ammonia resulting from intensive culture system and environmental pollution could cause disease occurrence in shrimp, but little information is available on its molecular mechanisms. In this study, we performed comparative transcriptome analysis among WSSV-infected shrimp under ammonia stress (LAV), WSSV-infected shrimp under normal water (LV), and normal shrimp under ammonia stress (LA) groups to identify the key genes and pathways involved in immunosuppression and increasing pathogen infection severity caused by ammonia toxicity in Litopenaeus vannamei. Totally, 526 significantly differential expressed genes (DEGs) were identified in LAV group compared to LV and LA groups, among which 270 genes were lost expressed and 67 genes uniquely expressed in the LAV group. According to the public functional reports for the annotated DEGs, they potentially involved in the following functions: (1) accelerating pathogen adhesion, invasion and multiplication; (2) reducing the ability for pathogen defense and immune response; (3) inhibiting positive regulation of apoptotic and antioxidant defense for host homeostasis; (4) inhibiting transcription and protein transport; (5) and increasing protein methylation and ubiquitination, etc. A total of 13 pathways were obtained mainly involving in this process, which mainly led to the following changes: (1) increasing the immunosuppression, anemia, endocrine dysfunction, neurotoxic effect and neuroinvasion, atherosclerosis and thrombogenesis, blood-brain barrier penetration, thyroid disorder, necrosis, inflammation, and circadian disturbance; (2) reducing the ability of vascular remodeling, angiogenesis, cell survival, migration, apoptosis, and lymph transferred to blood stream; (3) leading to cell hypertrophy, cellular shape changes, and mesangial matrix expansion. The present results firstly supplied molecular mechanisms for the ammonia toxicity inhibiting the immune system and increasing pathogen infection severity in shrimp, which is a prerequisite for better understanding the pathogenesis caused by ammonia toxicity.

CD147 (EMMPRIN) controls malignant properties of breast cancer cells by interdependent signaling of Wnt and JAK/STAT pathways

EMMPRIN (extracellular matrix metalloproteinase inducer, EMN, CD147) is a member of the immunoglobulin superfamily expressed in numerous cell types both as a soluble and a membrane-spanning glycoprotein. It is involved in many physiological processes, as well as in cancer. This study addresses mechanisms of crosstalk between EMN-driven cancer-related cellular responses and the canonical Wnt-pathway in MCF-7 breast carcinoma cells. Genetic knockdown of EMN in MCF-7 resulted in characteristic changes in cellular shape, organization of the actin cytoskeleton and malignancy profile, indicating that EMN expression represses cell motility, but, in contrast, exerts a stimulatory effect on cell proliferation and invasive properties. Increased invasiveness coincided with elevated expression of Wnt-target genes and established invasion driver matrix metalloproteinase MMP14. Activation of the downstream Wnt-pathway by means of heterologous β-catenin and/or TCF-4 expression, through inhibition of GSK-3β by LiCl treatment, or by cell stimulation with insulin-like growth factor-1 (IGF-1) resulted in increased EMN expression. EMN over-expression raised the ratio of the two opposing Wnt pathway-driven transcription factors Sp1 and Sp5, leading to stimulation of the EMN promoter. Furthermore, the EMN promoter was activated by a feed-forward circuit involving an EMN-dependent drop in expression of the repressive signal transducer and activator of transcription 1 (STAT1). Taken together, we show that the influence of EMMPRIN on malignancy-related properties of breast cancer cells is functionally connected to both Wnt- and JAK/STAT pathways.

Guided by curvature: shaping cells by coupling curved membrane proteins and cytoskeletal forces.

Eukaryote cells have flexible membranes that allow them to have a variety of dynamical shapes. The shapes of the cells serve important biological functions, both for cells within an intact tissue, and during embryogenesis and cellular motility. How cells control their shapes and the structures that they form on their surface has been a subject of intensive biological research, exposing the building blocks that cells use to deform their membranes. These processes have also drawn the interest of theoretical physicists, aiming to develop models based on physics, chemistry and nonlinear dynamics. Such models explore quantitatively different possible mechanisms that the cells can employ to initiate the spontaneous formation of shapes and patterns on their membranes. We review here theoretical work where one such class of mechanisms was investigated: the coupling between curved membrane proteins, and the cytoskeletal forces that they recruit. Theory indicates that this coupling gives rise to a rich variety of membrane shapes and dynamics, while experiments indicate that this mechanism appears to drive many cellular shape changes.This article is part of the theme issue 'Self-organization in cell biology'.

Classification of C2C12 cells at differentiation by convolutional neural network of deep learning using phase contrast images

In the field of regenerative medicine, tremendous numbers of cells are necessary for tissue/organ regeneration. Today automatic cell-culturing system has been developed. The next step is constructing a non-invasive method to monitor the conditions of cells automatically. As an image analysis method, convolutional neural network (CNN), one of the deep learning method, is approaching human recognition level. We constructed and applied the CNN algorithm for automatic cellular differentiation recognition of myogenic C2C12 cell line. Phase-contrast images of cultured C2C12 are prepared as input dataset. In differentiation process from myoblasts to myotubes, cellular morphology changes from round shape to elongated tubular shape due to fusion of the cells. CNN abstract the features of the shape of the cells and classify the cells depending on the culturing days from when differentiation is induced. Changes in cellular shape depending on the number of days of culture (Day 0, Day 3, Day 6) are classified with 91.3% accuracy. Image analysis with CNN has a potential to realize regenerative medicine industry.

From cells to tissue: A continuum model of epithelial mechanics.

A two-dimensional continuum model of epithelial tissue mechanics was formulated using cellular-level mechanical ingredients and cell morphogenetic processes, including cellular shape changes and cellular rearrangements. This model incorporates stress and deformation tensors, which can be compared with experimental data. Focusing on the interplay between cell shape changes and cell rearrangements, we elucidated dynamical behavior underlying passive relaxation, active contraction-elongation, and tissue shear flow, including a mechanism for contraction-elongation, whereby tissue flows perpendicularly to the axis of cell elongation. This study provides an integrated scheme for the understanding of the orchestration of morphogenetic processes in individual cells to achieve epithelial tissue morphogenesis.

Ann Miller: Shaping cells and scientists.

Miller studies how the cytoskeleton controls cellular shape change.

Active dynamics of tissue shear flow

We present a hydrodynamic theory to describe shear flows in developing epithelial tissues. We introduce hydrodynamic fields corresponding to state properties of constituent cells as well as a contribution to overall tissue shear flow due to rearrangements in cell network topology. We then construct a generic linear constitutive equation for the shear rate due to topological rearrangements and we investigate a novel rheological behaviour resulting from memory effects in the tissue. We identify two distinct active cellular processes: generation of active stress in the tissue, and actively driven topological rearrangements. We find that these two active processes can produce distinct cellular and tissue shape changes, depending on boundary conditions applied on the tissue. Our findings have consequences for the understanding of tissue morphogenesis during development.

Force percolation of contractile active gels.

Living systems provide a paradigmatic example of active soft matter. Cells and tissues comprise viscoelastic materials that exert forces and can actively change shape. This strikingly autonomous behavior is powered by the cytoskeleton, an active gel of semiflexible filaments, crosslinks, and molecular motors inside cells. Although individual motors are only a few nm in size and exert minute forces of a few pN, cells spatially integrate the activity of an ensemble of motors to produce larger contractile forces (∼nN and greater) on cellular, tissue, and organismal length scales. Here we review experimental and theoretical studies on contractile active gels composed of actin filaments and myosin motors. Unlike other active soft matter systems, which tend to form ordered patterns, actin-myosin systems exhibit a generic tendency to contract. Experimental studies of reconstituted actin-myosin model systems have long suggested that a mechanical interplay between motor activity and the network's connectivity governs this contractile behavior. Recent theoretical models indicate that this interplay can be understood in terms of percolation models, extended to include effects of motor activity on the network connectivity. Based on concepts from percolation theory, we propose a state diagram that unites a large body of experimental observations. This framework provides valuable insights into the mechanisms that drive cellular shape changes and also provides design principles for synthetic active materials.

Dynamic control of the mevalonate pathway expression for improved zeaxanthin production in Escherichia coli and comparative proteome analysis

Engineered heterologous multi-gene metabolic pathways often suffer from flux imbalance and toxic metabolites, as the production host typically lacks the regulatory mechanisms for the heterologous pathway. Here, we first coordinated the expression of all genes of the mevalonate (MEV) pathway from Saccharomyces cerevisiae using the tunable intergenic regions (TIGRs), and then dynamically regulated the TIGR-mediated MEV pathway to prevent the accumulation of toxic metabolites by using IPP/FPP-responsive promoter. After introduction of the dynamically controlled TIGR-mediated MEV pathway into Escherichia coli, the content and concentration of zeaxanthin in shaker flask cultures were 2.0- and 2.1-fold higher, respectively, than those of the strain harboring the statically controlled non-TIGR-mediated MEV pathway. The content and concentration of zeaxanthin in E. coli ZEAX (pZSPgadE-MevTTIGR-MevBTIGRIS-2) reached 722.46mg/L and 23.16mg/g dry cell weight (DCW), respectively, in 5.0L fed-batch fermentation. We also comparatively analyzed the proteomes between E. coli ZEAX and E. coli ZEAX (pZSPgadE-MevTTIGR-MevBTIGRIS-2) to understand the mechanism of zeaxanthin biosynthesis. The results of the comparative proteomes demonstrate that zeaxanthin overproduction may be associated with increased precursor availability, increased NADPH availability, increased ATP availability, oxidative stress response, and increased membrane storage capacity for zeaxanthin due to changes in both cellular shape and membrane composition.

Viability, morphology, and proteome of Mycobacterium smegmatis MSMEG_0319 knockout strain.

Mycobacterium tuberculosis Rv0228, a membrane protein, is predicted as a drug target through computational methods. MSMEG_0319 (MS0319) in Mycobacterium smegmatis mc(2) 155 is the ortholog of Rv0228. To study the effect of MS0319 protein on M. smegmatis, an MS0319 gene knockout strain (ΔMS0319) was generated via a homologous recombination technique in this study. The results showed that the lack of MS0319 protein in mc(2) 155 cells led to the loss of viability at nonpermissive temperature. Scanning electron microscopy and transmission electron microscopy observations showed drastic changes in cellular shape especially cell wall disruption in ΔMS0319 cells. Proteomic analysis of ΔMS0319 cells through LC-MS/MS revealed that 462 proteins had changes in their expressions by lacking MS0319 protein. The M. tuberculosis orthologs of these 462 proteins were found through BLASTp search and functional clustering and metabolic pathway enrichment were performed on the orthologs. The results revealed that most of them were enzymes involved in metabolism of carbohydrates and amino acids, indicating that Rv0228 played an important role in cellular metabolism. All these results suggested Rv0228 as a potential target for development of antituberculosis drugs.

Regulation and integrated functions of the actin cytoskeleton.

The actomyosin cytoskeleton is at the heart of many of the most dramatic cell and tissue shape changes, but linking molecular-scale organization and activity to cellular shape changes remains a substantial challenge. The dazzling array of force-generating structures assembled through the interplay of actin-binding proteins was on show in the Minisymposium on actin dynamics and structure in studies examining actin network functions in tissues, isolated cells, and in vitro. Myosin contractility is the best-studied mechanism for force production in isolated cells. However, until recently, it was widely believed that myosins only generate steady contraction. New evidence presented by Michelle Baird (Waterman lab) suggests that myosin IIA can also generate pulsatile contractions. Downstream of contractility, the resulting traction forces exerted on the cell matrix or an adjacent cell depend on the extent of coupling between adhesion molecules and the actin cytoskeleton. Kenneth Buck (Forscher lab) presented evidence that localized Arp2/3-dependent actin assembly can shield adhesion molecules from the forces generated by actin retrograde flow and provide a pushing force in the anterograde direction. The role of actin polymerization in generating protrusive forces is well established in the lamellipodium, a protruding sheet of membrane at the leading edge of migrating cells. Lamellipodia have been most studied in cells crawling on planar substrates, but cells in vivo can also migrate along fibrils of matrix. Charlotte Guetta-Terrier (Gauthier and Ladoux labs) analyzed cell motility on fabricated nanofibers coated with extracellular matrix to mimic this type of cell movement. Under these conditions, cells assemble an Arp2/3-dependent, fin-like structure that emanates from the cell body and travels along the fiber at a constant rate for up to several hundred micrometers. By studying how cells from the inner progenitor layer of the frog epidermis can move to the outer, mature epithelium, Jakub Sedzinski (Wallingford lab) revealed that actin polymerization also plays a role in apical surface expansion. The force necessary for this “apical emergence” is generated primarily by the emerging cell rather than by the neighboring cells. Formin-mediated actin assembly in the apical cortex of the emerging cell provides a pushing force sufficient to expand the apical membrane. Cortical actin was also the topic of a presentation by Guillaume Charras, who presented his group’s work on how this actin network is generated. Cortical actin lies just beneath the plasma membrane, where it plays important roles in cell mechanics and morphogenesis. Charras and colleagues showed that blebs shorn from cells can reform the cortical actin network. This enabled determination of cortical composition and identified Arp2/3 and mDia1 as the only two actin nucleation factors present in the cortex. Matt Smith (Paluch lab) presented new computational approaches devised to understand how tension is controlled by the properties and organization of actin filaments in the cortex. He showed that actin filament length and arrangement can modulate cortical tension, providing a new level of regulation for cell surface tension in addition to myosin contractility. Josh Winkelman (Kovar lab) presented work showing that differences in filament spacing arising from distinct cross-linkers may represent a sorting mechanism for localization of subsets of actin-binding proteins to different structures, such as myosin motors for the generation of contractility. Although it is widely recognized that actin polymerization can generate mechanical forces, a potential role for depolymerization has been invoked in theoretical work but is poorly documented experimentally. Philippe Bun (Lenart lab) described an actin network that forms in the nuclear region encompassing chromosomes during the first meiotic division in starfish oocytes. This network collects chromosomes under the plasma membrane to ensure a successful division of these very large cells. Experiments and modeling suggested that chromosome movement is driven by asymmetric assembly and disassembly of the actin network to create a pressure gradient that pushes the chromosomes toward the plasma membrane. Part of the reason that forces generated by depolymerization have rarely been documented is that the molecular mechanisms of depolymerization remain poorly understood. Vivian Tang (Tang and Brieher labs) presented recent progress on understanding the mechanism of action of cofilin, coronin, and Aip1 in depolymerizing actin filaments. This revealed a new mode of catastrophic depolymerization of filaments mediated by Aip1 where long stretches of F-actin rapidly dissociated into monomers.

Numerical investigations on reignition behavior of detonation diffraction

In this paper, by adopting a fifth-order weighted essentially non-oscillatory (WENO) scheme with a third-order TVD Runge–Kutta time stepping method for two-dimensional reactive Euler equations, a parallel code is developed, and reignition behavior after a self-sustaining detonation from the tube into free space filled with H2/O2 mixtures is investigated. The numerical results show that the initial pressure has a great influence on the detonation cellular width, and that as the initial pressure increases, the cellular width gradually decreases and the cellular shape changes from irregular structure to regular structure, demonstrating the detonation instability to stability transition. When the initial pressure is larger than 1.2 atm, the detonation wave expands over the edge of the splitter plate, reignition can come into being because enough transverse waves collide with each other at the leading edge of the expanding front. When the initial pressure is 1.2 atm, hot spots appear on the front, and ignite the combustible gas near the hot spots after detonation diffraction. When the initial pressure is 1.0 atm, reignition fails. These findings hint that a critical initial pressure exists between 1.0–1.2 atm for direct reignition after detonation diffraction.

The synergistic anticancer effect of cisplatin combined with Oldenlandia diffusa in osteosarcoma MG-63 cell line in vitro.

BackgroundOldenlandia diffusa (OD) is a well-known traditional Chinese medicine, which is used to prevent and treat many disorders, especially cancers. However, its role in osteosarcoma has not been well understood. Here, we used OD and cisplatin individually and combined in osteosarcoma MG-63 cell to explore whether OD could induce cellular apoptosis and suppress the ability of proliferation and invasion of osteosarcoma MG-63 cell.MethodsThe changes of cellular shape were analyzed by optical microscopy. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay was used to analyze cell survival rate in vitro. Flow cytometry was performed to detect cell cycle and cell death. Scratch migration assay was used to evaluate cell migration and invasion. Western blot was performed to determine the expression levels of pro-apoptotic and anti-apoptotic protein.ResultsIn this study, we found that the survival rate reduced significantly in the combined group compared with the individual group and control group. The apoptosis-inducing effect of combined application was much more significant than that of individual application. The invasion ability of combined application was significantly lower than that of the individual application. In the combined group, there were high expression levels of pro-apoptotic protein and low expression of anti-apoptotic protein. Cell-cycle analysis showed a change in the cell-cycle distribution and arrested cells in G2-M phase.ConclusionIn this study, we found that OD inhibited proliferation and induced apoptosis in the human osteosarcoma MG-63 cell line in a time-dependent and dose-dependent manner. In addition, OD displayed inhibitory activity on MG-63 cell proliferation and invasion and the study also showed that OD activity might be mediated by caspase activation. These data suggest that OD might represent a novel, efficient candidate agent for further experimentation in osteosarcoma treatment.