Recent clinical trials and optical control as a potential strategy to develop microtubule-targeting drugs in colorectal cancer management

Colorectal cancer(CRC)has remained the second and the third leading cause of cancer-related death worldwide and in the United States,respectively.Although significant improvement in overall survival has been achieved,death in adult populations under the age of 55 appears to have increased in the past decades.Although new classes of therapeutic strategies such as immunotherapy have emerged,their application is very limited in CRC so far.Microtubule(MT)inhibitors such as taxanes,are not generally successful in CRC.There may be some way to make MT inhibitors work effectively in CRC.One potential advantage that we can take to treat CRC may be the combination of optical techniques coupled to an endoscope or other fiber optics-based devices.A combination of optical devices and photo-activatable drugs may allow us to locally target advanced CRC cells with highly potent MT-targeting drugs.In this Editorial review,we would like to discuss the potential of optogenetic approaches in CRC management.

Fidgetin interacting with microtubule end binding protein EB3 affects axonal regrowth in spinal cord injury

Fidgetin,a microtubule-severing enzyme,regulates neurite outgrowth,axonal regeneration,and cell migration by trimming off the labile domain of microtubule polymers.Because maintenance of the microtubule labile domain is essential for axon initiation,elongation,and navigation,it is of interest to determine whether augmenting the microtubule labile domain via depletion of fidgetin serves as a therapeutic approach to promote axonal regrowth in spinal cord injury.In this study,we constructed rat models of spinal cord injury and sciatic nerve injury.Compared with spinal cord injury,we found that expression level of tyrosinated microtubules in the labile portion of microtubules continuously increased,whereas fidgetin decreased after peripheral nerve injury.Depletion of fidgetin enhanced axon regeneration after spinal cord injury,whereas expression level of end binding protein 3(EB3)markedly increased.Next,we performed RNA interference to knockdown EB3 or fidgetin.We found that deletion of EB3 did not change fidgetin expression.Conversely,deletion of fidgetin markedly increased expression of tyrosinated microtubules and EB3.Deletion of fidgetin increased the amount of EB3 at the end of neurites and thereby increased the level of tyrosinated microtubules.Finally,we deleted EB3 and overexpressed fidgetin.We found that fidgetin trimmed tyrosinated tubulins by interacting with EB3.When fidgetin was deleted,the labile portion of microtubules was elongated,and as a result the length of axons and number of axon branches were increased.These findings suggest that fidgetin can be used as a novel therapeutic target to promote axonal regeneration after spinal cord injury.Furthermore,they reveal an innovative mechanism by which fidgetin preferentially severs labile microtubules.

Study on regulating mechanisms of oxocrebanine obtained from Stephania hainanensis H.S.Lo et Y.Tsoong on microtubule sites and tubulin in human breast cancer MCF-7 cells

Objective:To determine the destructive ability of oxocrebanine,an anti-breast cancer active compound obtained from Stephania hainanensis H.S.Lo et Y.Tsoong,on microtubule network,and investigate the effect of oxocrebanine on microtubule network homeostasis at both molecular and cellular levels.Methods:the EBI site competition method and molecular docking method were used to determine the occupation of the microtubule site of oxocrebanine.Western Blot was used to detect the effect of oxocrebanine on microtubule-associated proteins including STAT3,PAK1,CAMK4,and PKA.Results:The results of EBI site competition assay showed that the binding of EBI toβ-Tubulin covalent fusions produced adducts that appeared in regions of lower molecular weight thanβ-tubulin(ctrl 2).Molecular docking results showed that oxocrebanine could occupy the colchicine site of microtubule proteins.As revealed by Western Blot,the expression of STAT3 protein was decreased after MCF-7 cells have been treated with low,medium,and high concentration of oxocrebanine or the positive drug taxol for 48 h(P<0.01).The expression levels of PAK1 and Camk4 proteins aslo showed significant reductions(P<0.05,or P<0.01).Oxocrebanine also decreased the PKA protein in MCF-7 cells compared to the control group(P<0.01).Conclusions:Oxocrebanine,a ligand that binds at the colchicine site of tubulin,perturbs tubulin polymerization and causes mitosis in MCF-7 cells,thus leading to MCF-7 cell death.Oxocrebanine may promote microtubule dynamics through stathmin by inhibiting the expression levels of STAT3,PAK1,Camk4,and PKA proteins in MCF-7 cells.Oxocrebanine interfers with spindle formation,and ultimately causes mitotic catastrophe in MCF-7 cells.

Boosting ferroptosis and microtubule inhibition for antitumor therapy via a carrier-free supermolecule nanoreactor

Traditional microtubule inhibitors fail to significantly enhance+e effect of colorectal cancer;hence,new and efficient strategies are necessary.In+is study,a supramolecular nanoreactor(DOC@TA-Fe^(3+))based on tannic acid(TA),iron ion(Fe^(3+)),and docetaxel(DOC)wi+microtubule inhibition,reactive oxygen species(ROS)generation,and gluta+ione peroxidase 4(GPX4)inhibition,is prepared for ferroptosis/apoptosis treatment.After internalization by CT26 cells,+e DOC@TA-Fe^(3+)nanoreactor escapes from+e lysosomes to release payloads.+e subsequent Fe^(3+)/Fe^(2+)conversion mediated by TA reducibility can trigger+e Fenton reaction to enhance+e ROS concentration.Additionally,Fe^(3+)can consume gluta+ione to repress+e activity of GPX4 to induce ferroptosis.Meanwhile,+e released DOC controls microtubule dynamics to activate+e apoptosis pa+way.+e superior in vivo antitumor efficacy of DOC@TA-Fe^(3+)nanoreactor in terms of tumor grow+inhibition and improved survival is verified in CT26 tumor-bearing mouse model.+erefore,+e nanoreactor can act as an effective apoptosis and ferroptosis inducer for application in colorectal cancer+erapy.

Kinesin-microtubule interaction reveals the mechanism of kinesin-1 for discriminating the binding site on microtubule

Microtubule catalyzes the mechanochemical cycle of kinesin,a kind of molecular motor,through its crucial roles in kinesin's gating,ATPase and force-generation process.These functions of microtubule are realized through the kinesin-microtubule interaction.The binding site of kinesin on the microtubule surface is fixed.For most of the kinesin-family members,the binding site on microtubule is in the groove betweenα-tubulin andβ-tubulin in a protofilament.The mechanism of kinesin searching for the appropriate binding site on microtubule is still unclear.Using the molecular dynamics simulation method,we investigate the interactions between kinesin-1 and the different binding positions on microtubule.The key non-bonded interactions between the motor domain and tubulins in kinesin's different nucleotide-binding states are listed.The differences of the amino-acid sequences betweenα-andβ-tubulins make kinesin-1 binding to theα–βgroove much more favorable than to theβ–αgroove.From these results,a two-step mechanism of kinesin-1 to discriminate the correct binding site on microtubule is proposed.Most of the kinesin-family members have the conserved motor domain and bind to the same site on microtubule,the mechanism may also be shared by other family members of kinesin.

Ideal type 1 is caused by a point mutation in the a-tubulin gene that affects microtubule arrangement in soybean

Plant architecture is a target of crop improvement.The soybean mutant ideal type 1(it1)displays a pleiotropic phenotype characterized by compact plant architecture,reduced plant height,shortened petioles,wrinkled leaves,and indented seeds.Genetic analysis revealed that the pleiotropic phenotype was controlled by an incomplete dominant gene.We characterized the cellular phenotypes of it1 and positionally cloned the it1 locus.Detailed morphogenetic analysis of the it1 mutant revealed an excess of xylem cells and expanded phloem,and polygonal pavement cells.Positional cloning showed that the phenotype was caused by a G-to-A mutation in the second exon of the a-tubulin gene(Glyma.05G157300).The mutation altered microtubule arrangement in pavement cells,changing their morphology.Overexpression of Gmit1 resulted in an it1-like phenotype and polygonal pavement cells and microtubules of overexpressors were parallel or slightly inclined.Five suppressor mutants able to suppress the phenotype of it1 were obtained by EMS mutagenesis in the it1 background.All these mutants carried an additional mutation in the it1 gene.These results suggest that the pleiotropic phenotype of it1 is caused by the mutation in the atubulin gene.

Dissipation and amplification management in an electrical model of microtubules: Hybrid behavior network

The control of dissipation and amplification of solitary waves in an electrical model of a microtubule is demonstrated.This model consists of a shunt nonlinear resistance–capacitance(J(V)–C(V)) circuit and a series resistance–inductance(R–L) circuit. Through linear dispersion analysis, two features of the network are found, that is, low bandpass and bandpass filter characteristics. The effects of the conductance’s parameter λ on the linear dispersion curve are also analyzed. It appears that an increase of λ induces a decrease(an increase) of the width of the bandpass filter for positive(negative) values of λ. By applying the reductive perturbation method, we derive the equation governing the dynamics of the modulated waves in the system. This equation is the well-known nonlinear Schr?dinger equation extended by a linear term proportional to a hybrid parameter σ, i.e., a dissipation or amplification coefficient. Based on this parameter, we successfully demonstrate the hybrid behavior(dissipation and amplification) of the system. The exact and approximate solitary wave solutions of the obtained equation are derived, and the effects of the coefficient σ on the characteristic parameters of these waves are investigated. Using the analytical solutions found, we show numerically that the waves that are propagated throughout the system can be dissipated, amplified, or remain stable depending on the network parameters. These results are not only in agreement with the analytical predictions, but also with the existing experimental results in the literature.

Changes in microtubule-associated protein tau during peripheral nerve injury and regeneration

Tau, a primary component of microtubule-associated protein, promotes microtubule assembly and/or disassembly and maintains the stability of the microtubule structure. Although the importance of tau in neurodegenerative diseases has been well demonstrated, wheth- er tau is involved in peripheral nerve regeneration remains unknown. In the current study, we obtained sciatic nerve tissue from adult rats 0, 1, 4, 7, and 14 days after sciatic nerve crush and examined tau mRNA and protein expression levels and the location of tau in the sciatic nerve following peripheral nerve injury. The results from our quantitative reverse transcription polymerase chain reaction analysis showed that compared with the uninjured control sciatic nerve, mRNA expression levels for both tau and tau tubulin kinase 1, a serine/ threonine kinase that regulates tau phosphorylation, were decreased following peripheral nerve injury. Our western blot assay results suggested that the protein expression levels of tau and phosphorylated tau initially decreased 1 day post nerve injury but then gradually increased. The results of our immunohistochemical labeling showed that the location of tau protein was not altered by nerve injury. Thus, these results showed that the expression of tau was changed following sciatic nerve crush, suggesting that tau may be involved in periph- eral nerve repair and regeneration.

Zonula occludin toxin,a microtubule binding protein

AIM To investigate the interaction of Zot withmicrotubule.METHODS Zot affinity column was applied topurify Zot-binding protein（s）from crudeintestinal cell lysates.After incubation at roomtemperature,the column was washed and theproteins bound to the Zot affinity column wereeluted by step gradient with NaCl(0.3 mol·L-1-0.5mol·L-1).The fractions were subjected to6.0%-15.0%（w/v）gradient SDS-PAGE andthen transferred to PVDF membrane for N-terminal sequencing.Purified Zot and tauprotein were blotted by using anti-Zot or anti-tauantibodies.Finally,purified Zot was tested in anin vitro tubulin binding assay.RESULTS Fractions from Zot affinity columnyielded two protein bands with a Mr of 60 kU and45kU respectively.The N-terminal sequence ofthe 60 kU band resulted identical to β-tubulin.Zot also cross-reacts with anti-tau antibodies.Inthe in vitro tubulin binding assay,Zot co-precipitate with Mt,further suggesting that Zotpossesses tubulin-binding properties.CONCLUSION Taken together,these resultssuggest that Zot regulates the permeability ofintestinal tight junctions by binding tointracellular Mt,with the subsequent activationof the intracellular signaling leading to thepermeabilization of intercellular tight junctions.

Regulation of microtubule array in its self-organized dense active crowds

Microtubule self-organization under mechanical and chemical regulations plays a central role in cytokinesis and cel-lular transportations.In plant-cells,the patterns or phases of cortical microtubules organizations are the direct indicators of cell-phases.The dense nematic pattern of cortical microtubule array relies on the regulation of single microtubule dynamics with mechanical coupling to steric interaction among the self-organized microtubule crowds.Building upon previous mini-mal models,we investigate the effective microtubule width,microtubule catastrophe rate,and zippering angle as factors that regulate the self-organization of the dense nematic phase.We find that by incorporating the effective microtubule width,the transition from isotropic to the highly ordered nematic phase(NI phase)with extremely long microtubules will be gapped by another nematic phase which consists of relative short microtubules(NII phase).The NII phase in the gap grows wider with the increase of the microtubule width.We further illustrate that in the dense phase,the collision-induced catastrophe rate and an optimal zippering angle play an important role in controlling the order-disorder transition,as a result of the coupling between the collision events and ordering.Our study shows that the transition to dense microtubule array requires the cross-talk between single microtubule growth and mechanical interactions among microtubules in the active crowds.

Rho-associated protein kinase modulates neurite extension by regulating microtubule remodeling and vinculin distribution

Rho-associated protein kinase is an essential regulator of cytoskeletal dynamics during the process of neurite extension. However, whether Rho kinase regulates microtubule remodeling or the distri- bution of adhesive proteins to mediate neurite outgrowth remains unclear. By specifically modulat- ing Rho kinase activity with pharmacological agents, we studied the morpho-dynamics of neurite outgrowth. We found that lysophosphatidic acid, an activator of Rho kinase, inhibited neurite out- growth, which could be reversed by Y-27632, an inhibitor of Rho kinase. Meanwhile, reorganization of microtubules was noticed during these processes, as indicated by their significant changes in the soma and growth cone. In addition, exposure to lysophosphatidic acid led to a decreased mem- brane distribution of vinculin, a focal adhesion protein in neurons, whereas Y-27632 recruited vin- culin to the membrane. Taken together, our data suggest that Rho kinase regulates rat hippocampal neurite growth and microtubule formation via a mechanism associated with the redistribution of vinculin.

Preparation and magnetic properties of Fe_2O_3 microtubules prepared by sol-gel template method

Fe（OH）3 precursor sol was prepared by a sol-gel method. The precursor sol was dipped onto the absorbent cotton, and gel was formed on the absorbent cotton template after the volatilization of moisture. Fe2O3 microtubules were synthesized after the process of self-propagation or calcination. The phase, morphology, and particle diameter of the samples were examined by X-ray diffraction （XRD） and scanning electron microscopy （SEM）, and the magnetic properties of the samples were measured using a vibrating sample magnetometer （VSM）. The external diameters of Fe2O3 microtubules ranged between 8 and 13 μm, and the wall thicknesses ranged between 0.5 and 2 μm. The type of the calcination method plays a significant role in developing the Fe2O3 phase and the variation in the magnetic properties in the sol-gel template complexing method. γ-Fe2O3 was synthesized by a self-propagation method. However, α-Fe203 was synthesized after calcination at 400℃ for 2 h. The coercivity of the samples synthesized by calcination at 400℃ for 2 h after self-propagation was found to increase significantly, thereby presenting hard magnetic properties.

Role of microtubule dynamics in Wallerian degeneration and nerve regeneration after peripheral nerve injury

Wallerian degeneration,the progressive disintegration of distal axons and myelin that occurs after peripheral nerve injury,is essential for creating a permissive microenvironment for nerve regeneration,and involves cytoskeletal reconstruction.However,it is unclear whether microtubule dynamics play a role in this process.To address this,we treated cultured sciatic nerve explants,an in vitro model of Wallerian degeneration,with the microtubule-targeting agents paclitaxel and nocodazole.We found that paclitaxel-induced microtubule stabilization promoted axon and myelin degeneration and Schwann cell dedifferentiation,whereas nocodazole-induced microtubule destabilization inhibited these processes.Evaluation of an in vivo model of peripheral nerve injury showed that treatment with paclitaxel or nocodazole accelerated or attenuated axonal regeneration,as well as functional recovery of nerve conduction and target muscle and motor behavior,respectively.These results suggest that microtubule dynamics participate in peripheral nerve regeneration after injury by affecting Wallerian degeneration.This study was approved by the Animal Care and Use Committee of Southern Medical University,China(approval No.SMUL2015081) on October 15,2015.

Biological Fingerprinting Analysis of Interaction Between Taxoids in Taxus and Microtubule Protein by Microdialysis Coupled with High-performance Liquid Chromatography/Mass Spectrometry for Screening Antimicrotubule Agents

Some natural products, such as traditional Chinese medicines（TCMs）, contain compounds with anticancer activity and have attracted a great interest in recent years as alternative anticancer therapies. A quick and convenient assay for screening antimicrotubule compounds in which in vitro microdialysis/high-performance liquid chromatography （HPLC） is used to monitor the binding of the compounds extracted from TCM Taxus cuspidata Siebold ＆ Zucc（Taxus） to microtubules is reported. It was observed that the extract of Taxus contains at least five compounds which have affinity interaction with microtubules by biological fingerprinting analysis, and they were identified as the taxoids of taxol, baccatin III, 10-deacetylbaccatin Ⅲ（10-DAB）, cephalomannine and 7-epi-10-deacetyltaxol （7-epi-10-DAT） based on the comparison of their high-performance liquid chromatographic/mass spectrometric and UV spectra with those of the standard samples, both assembly-promoting and disassembly-inhibiting characteristics of those compounds were evaluated. It was observed that baccatin Ⅲ and 10-DAB bound to microtubules and the binding degrees were influenced by GTP. Competitive binding behavior of taxol with other four taxoids to microtubules was also investigated.

Stathmin destabilizing microtubule dynamics promotes malignant potential in cancer cells by epithelial-mesenchymal transition

BACKGROUND： Stathmin is a ubiquitous cytosolic regulatory phosphoprotein and is overexpressed in different human malignancies. The main physiological function of stathmin is to interfere with microtubule dynamics by promoting depolymerization of microtubules or by preventing polymerization of tubulin heterodimers. Stathmin plays important roles in regulating many cellular functions as a result of its microtubuledestabilizing activity. Currently, the critical roles of stathmin in cancer cells, as well as in lymphocytes have been valued. This review discusses stathmin and microtubule dynamics in cancer development, and hypothesizes their possible relationship with epithelial-mesenchymal transition（EMT）.DATA SOURCES： A PubMed search using such terms as ＂stathmin＂, ＂microtubule dynamics＂, ＂epithelial-mesenchymal transition＂, ＂EMT＂, ＂malignant potential＂ and ＂cancer＂ was performed to identify relevant studies published in English.More than 100 related articles were reviewed.RESULTS： The literature clearly documented the relationship between stathmin and its microtubule-destabilizing activity of cancer development. However, the particular mechanism is poorly understood. Microtubule disruption is essential for EMT, which is a crucial process during cancer development. As a microtubule-destabilizing protein, stathmin may promote malignant potential in cancer cells by initiating EMT.CONCLUSIONS： We propose that there is a stathminmicrotubule dynamics-EMT（S-M-E） axis during cancer development. By this axis, stathmin together with itsmicrotubule-destabilizing activity contributes to EMT, which stimulates the malignant potential in cancer cells.

Mechanics of Centriole Microtubules

This is a review paper describing recent findings about the physical properties of centriolar microtubules. Microtubules are the principal structures making up the centrioles. The centrioles in turn are the principal agents in cell duplication and division (mitosis). The microtubules are seen to be long hollow cylinders: approximately 400 nm in length, with a 24 nm outside diameter, and a 5 nm wall thickness. Within the centrioles, the microtubules are arranged into nine parallel sets of triplets—thus numbering 27 parallel cylinders per centriole. Each normal eukaryotic (human and animal) cell, not in mitosis, has two perpendicular centrioles connected at their proximal (base) ends. During mitosis, these two become four, resulting in a total of 108 centriolar microtubules. The structure of the microtubules themselves is found to consist of 13 parallel filaments making up the cylinder walls. The filaments are composed of approximately 40 and β-tubulin connected end-to-end with their proximal (base) ends anchored in γ-tubulin. The longitudinal vibrations of the filaments are believed to create an electro-magnetic field within the cell which plays an important role in mitosis.

Inhibition of kinesin-5 improves regeneration of injured axons by a novel microtubule-based mechanism

Microtubules have been identified as a powerful target for augmenting regeneration of injured adult axons in the central nervous system. Drugs that stabilize microtubules have shown some promise, but there are concerns that abnormally stabilizing microtubules may have only limited benefits for regeneration, while at the same time may be detrimental to the normal work that microtubules perform for the axon. Kinesin-5 （also called kifl I or EgS）, a molecular motor protein best known for its crucial role in mitosis, acts as a brake on microtubule movements by other motor proteins in the axon. Drugs that inhibit kinesin-5, originally developed to treat cancer, result in greater mobility of microtubules in the axon and an overall shift in the forces on the microtubule array. As a result, the axon grows faster, retracts less, and more readily enters environments that are inhibitory to axonal regeneration. Thus, drugs that inhibit kinesin-5 offer a novel microtubule-based means to boost axonal regeneration without the concerns that accompany abnormal stabilization of the microtubule array. Even so, inhibiting kinesin-5 is not without its own caveats, such as potential problems with navigation of the regenerating axon to its target, as well as morphological effects on dendrites that could affect learning and memory if the drugs reach the brain.

SIRT2 regulates microtubule stabalization in diabetic cardiomyopath＇.

Aim Stable microtubules （MTs） is involved the mechanism of diabetic cardiomyopathy （DCM）, which is induced by acetylation of α-tubulin. The present study investigated whether SIRT2, a deacetylase, regulates MT stability through α-tubulin deacetylation in DCM and whether the receptor of advanced glycation end products （AGEs） signaling pathway is involved in this effect. Methods Type 1 diabetic mellitus （T1DM） rats model was established by a single intraperitoneal injection of streptozotocin （STZ, 65 mg · kg^-1） , and neonatal rat cardio- myocytes were also cultured. Heart function was detected by Doppler. MT stability was elevated by β-tubulin ex- pression density. The protein expression of SIRT2, acetylated α-tubulin and AGEs receptor were detected by immu- nohistochemistry or Western blots. The interaction of SIRT2 and acetylated α-tubulin was detected by Co-immuno- precipitation. Results In an animal model of T1DM, Western blot and immunohistochemistry revealed downregu- lation of SIRT2 but upregulation of the acetylated α-tubulin protein. These effects were reduced by treatment of aminoguanidine, an inhibitor of AGEs production. HDAC6 expression did not regulated in heart. In primary cul- tures of neonatal rat cardiomyocytes, the AGEs treatment impaired the SIRT2/acetylated α-tubulin signaling path- way, and SIRT2-overexpression reversed the function of AGEs on cardiomyocytes. In addition, gene silencing of AGEs receptor alleviated the impairment effect of AGEs on cardiomyocytes. Conclusion In conclusion, these data demonstrate that AGEs/AGEs receptor promote MT stabilization via the suppression of the SIRT2/acetylated α-tu- bulin signaling pathway in DCM development.

Cortical Microtubule Reorientation and Its Relation to Cell Surface Texture of Epidermal Cells of Arabidopsis Thaliana Hypocotyls under Simulated Microgravity Conditions

Gravitropic curvature growth of Arabidopsis hypocotyls mainly occurred in the rapid growing Elongation Zone(EZI),not in the slow-growing Elongation Zone(EZII).By examining reorientation of Microtubules(MT)and phenotype of the cell wall in the EZI and the EZII of Arabidopsis hypocotyls under normal gravitational condition,it is found that MTs in the rapid growing epidermal cells were mainly in the transverse direction,while those in the non-growing epidermal cells were in the longitudinal directions.However,this difference in cortical MT arrays between the EZI and EZII cells disappeared when the seedlings were exposed to the simulated microgravity condition on a horizontal clinostat.Field emission scanning electron microscopy revealed that the surface texture of epidermal cells,like the direction of the MT,in the EZI and the EZII also became similar when exposed to the simulated microgravity condition.This result indicated that simulate microgravity could modify the potential differentiation between the EZI and the EZII by affecting the orientation of cortical MT in the epidermal cells.

CDK11 negatively regulates Wnt/β-catenin signaling in the endosomal compartment by affecting microtubule stability

Objectives:Improper activation of Wnt/β-catenin signaling has been implicated in human diseases.Beyond the well-studied glycogen synthase kinase 3p(GSK3p)and casein kinase 1(CK1),other kinases affecting Wnt/β-catenin signaling remain to be defined.Methods:To identify the kinases that modulate Wnt/β-catenin signaling,we applied a kinase small interfering RNA(siRNA)library screen approach.Luciferase assays,immunoblotting,and real-time polymerase chain reaction(PCR)were performed to confirm the regulation o f the Wnt/β-catenin signaling pathway by cyclin-dependent kinase 11(CDK11)and to investigate the underlying mechanism.Confocal immunofluorescence,coimmunoprecipitation(co-IP),and scratch wound assays were used to demonstrate colocalization,detect protein interactions,and explore the function of CDK11.Results:CDK11 was found to be a significant candidate kinase participating in the negative control of Wnt/P-catenin signaling.Down-regulation of CDK11 led to the accumulation of Wnt/β-catenin signaling receptor complexes,in a manner dependent on intact adenomatosis polyposis coli(APC)protein.Further analysis showed that CDK11 modulation of Wnt/P-catenin signaling engaged the endolysosomal machinery,and CDK11 knockdown enhanced the colocalization of Wnt/β-catenin signaling receptor complexes with early endosomes and decreased colocalization with lysosomes.Mechanistically,CDK11 was found to function in Wnt/β-catenin signaling by regulating microtubule stability.Depletion of CDK11 down-regulated acetyl-a-tubulin.Moreover,co-IP assays demonstrated that CDK11 interacts with the a-tubulin deacetylase SIRT2,whereas SIRT2 down-regulation in CDK11-depleted cells reversed the accumulation of Wnt/(3-catenin signaling receptor complexes.CDK11 was found to suppress cell migration through altered W nt/β-catenin signaling.Conclusions:CDK11 is a negative modulator of Wnt/β-catenin signaling that stabilizes microtubules,thus resulting in the dysregulation of receptor complex trafficking from early endosomes to lysosomes.