Acinar to ß-like cell conversion through inhibition of focal adhesion kinase.

Insufficient functional ß-cell mass causes diabetes; however, an effective cell replacement therapy for curing diabetes is currently not available. Reprogramming of acinar cells toward functional insulin-producing cells would offer an abundant and autologous source of insulin-producing cells. Our lineage tracing studies along with transcriptomic characterization demonstrate that treatment of adult mice with a small molecule that specifically inhibits kinase activity of focal adhesion kinase results in trans-differentiation of a subset of peri-islet acinar cells into insulin producing ß-like cells. The acinar-derived insulin-producing cells infiltrate the pre-existing endocrine islets, partially restore ß-cell mass, and significantly improve glucose homeostasis in diabetic mice. These findings provide evidence that inhibition of the kinase activity of focal adhesion kinase can convert acinar cells into insulin-producing cells and could offer a promising strategy for treating diabetes.

LAMC1 attenuates neuronal apoptosis via FAK/PI3K/AKT signaling pathway after subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The poor prognosis in patients with subarachnoid hemorrhage (SAH) is often attributed to neuronal apoptosis. Recent evidence suggests that Laminin subunit gamma 1 (LAMC1) is essential for cell survival and proliferation. However, the effects of LAMC1 on early brain injury after SAH and the underlying mechanisms are unknown. The current study aimed to reveal the anti-neuronal apoptotic effect and the potential mechanism of LAMC1 in the rat and in the in vitro SAH models. METHODS: The SAH model of Sprague-Dawley rats was established by endovascular perforation. Recombinant LAMC1 (rLAMC1) was administered intranasally 30 min after modeling. LAMC1 small interfering RNA (LAMC1 siRNA), focal adhesion kinase (FAK)-specific inhibitor Y15 and PI3K-specific inhibitor LY294002 were administered before SAH modeling to explore the neuroprotection mechanism of rLAMC1. HT22 cells were cultured and stimulated by oxyhemoglobin to establish an in vitro model of SAH. Subsequently, SAH grades, neurobehavioral tests, brain water content, blood-brain barrier permeability, western blotting, immunofluorescence, TUNEL, and Fluoro-Jade C staining were performed. RESULTS: The expression of endogenous LAMC1 was markedly decreased after SAH, both in vitro and in vivo. rLAMC1 significantly reduced the brain water content and blood-brain barrier permeability, improved short- and long-term neurobehavior, and decreased neuronal apoptosis. Furthermore, rLAMC1 treatment significantly increased the expression of p-FAK, p-PI3K, p-AKT, Bcl-XL, and Bcl-2 and decreased the expression of Bax and cleaved caspase -3. Conversely, knockdown of endogenous LAMC1 aggravated the neurological impairment, suppressed the expression of Bcl-XL and Bcl-2, and upregulated the expression of Bax and cleaved caspase-3. Additionally, the administration of Y15 and LY294002 abolished the protective roles of rLAMC1. In vitro, rLAMC1 significantly reduced neuronal apoptosis, and the protective effects were also abolished by Y15 and LY294002. CONCLUSION: Exogenous LAMC1 treatment improved neurological deficits after SAH in rats, and attenuated neuronal apoptosis in both in vitro and in vivo SAH models, at least partially through the FAK/PI3K/AKT pathway.

Flavokawain C inhibits proliferation and migration of liver cancer cells through FAK/PI3K/AKT signaling pathway.

PURPOSE: This study investigated the potential applicability and the underlying mechanisms of flavokawain C, a natural compound derived from kava extracts, in liver cancer treatment. METHODS: Drug distribution experiment used to demonstrate the preferential tissues enrichment of flavokawain C. Cell proliferation, apoptosis and migration effect of flavokawain C were determined by MTT, colony formation, EdU staining, cell adhesion, transwell, flow cytometry and western blot assay. The mechanism was explored by comet assay, immunofluorescence assay, RNA-seq-based Kyoto encyclopedia of genes and genomes analysis, molecular dynamics, bioinformatics analysis and western blot assay. The anticancer effect of flavokawain C was further confirmed by xenograft tumor model. RESULTS: The studies first demonstrated the preferential enrichment of flavokawain C within liver tissues in vivo. The findings demonstrated that flavokawain C significantly inhibited proliferation and migration of liver cancer cells, induced cellular apoptosis, and triggered intense DNA damage along with strong DNA damage response. The findings from RNA-seq-based KEGG analysis, molecular dynamics, bioinformatics analysis, and western blot assay mechanistically indicated that treatment with flavokawain C notably suppressed the FAK/PI3K/AKT signaling pathway in liver cancer cells. This effect was attributed to the induction of gene changes and the binding of flavokawain C to the ATP sites of FAK and PI3K, resulting in the inhibition of their phosphorylation. Additionally, flavokawain C also displayed the strong capacity to inhibit Huh-7-derived xenograft tumor growth in mice with minimal adverse effects. CONCLUSIONS: These findings identified that flavokawain C is a promising anticancer agent for liver cancer treatment.

Targeting of focal adhesion kinase enhances the immunogenic cell death of PEGylated liposome doxorubicin to optimize therapeutic responses of immune checkpoint blockade.

BACKGROUNDS: Immune checkpoint blockade (ICB) is widely considered to exert long-term treatment benefits by activating antitumor immunity. However, many cancer patients show poor clinical responses to ICB due in part to the lack of an immunogenic niche. Focal adhesion kinase (FAK) is frequently amplified and acts as an immune modulator across cancer types. However, evidence illustrates that targeting FAK is most effective in combination therapy rather than in monotherapy. METHODS: Here, we used drug screening, in vitro and in vivo assays to filter out that doxorubicin and its liposomal form pegylated liposome doxorubicin (PLD) showed synergistic anti-tumor effects in combination with FAK inhibitor IN10018. We hypothesized that anti-tumor immunity and immunogenic cell death (ICD) may be involved in the treatment outcomes through the data analysis of our clinical trial testing the combination of IN10018 and PLD. We then performed cell-based assays and animal studies to detect whether FAK inhibition by IN10018 can boost the ICD of PLD/doxorubicin and further established syngeneic models to test the antitumor effect of triplet combination of PLD, IN10018, and ICB. RESULTS: We demonstrated that the combination of FAK inhibitor IN10018, and PLD/doxorubicin exerted effective antitumor activity. Notably, the doublet combination regimen exhibited response latency and long-lasting treatment effects clinically, outcomes frequently observed in immunotherapy. Our preclinical study confirmed that the 2-drug combination can maximize the ICD of cancer cells. This approach primed the tumor microenvironment, supplementing it with sufficient tumor-infiltrating lymphocytes (TILs) to activate antitumor immunity. Finally, different animal studies confirmed that the antitumor effects of ICB can be significantly enhanced by this doublet regimen. CONCLUSIONS: We confirmed that targeting FAK by IN10018 can enhance the ICD of PLD/doxorubicin, further benefiting the anti-tumor effect of ICB. The animal tests of the triplet regimen warrant further discovery in the real world.

A selective CB2R agonist (JWH133) protects against pulmonary fibrosis through inhibiting FAK/ERK/S100A4 signaling pathways.

BACKGROUND: The combination of the endocannabinoid system (ECS) and the type 2 cannabinoid receptor (CB2R) can activate various signal pathways, leading to distinct pathophysiological roles. This interaction has gained significant attention in recent research on fibrosis diseases. Focal adhesion kinase (FAK) plays a crucial role in regulating signals from growth factor receptors and Integrins. It is also involved in the transformation of fibroblasts into myofibroblasts. This study aims to investigate the impact of the CB2R agonist JWH133 on lung fibrosis and its potential to alleviate pulmonary fibrosis in mice through the FAK pathway. METHODS: The C57 mice were categorized into five groups: control, BLM, BLM + JWH133, BLM + JWH133 + NC, and BLM + JWH133 + FAK groups.JWH133 was administered to mice individually or in conjunction with the FAK vector. After 21 days, pathological changes in mouse lung tissues, inflammatory factor levels, hydroxyproline levels, and collagen contents were evaluated. Moreover, the levels of the FAK/ERK/S100A4 pathway-related proteins were measured. RESULTS: JWH133 treatment decreased inflammatory factor levels, attenuated pathological changes, and reduced extracellular matrix accumulation in the mouse model of bleomycin-induced pulmonary fibrosis; however, these effects were reversed by FAK. JWH133 attenuated fibrosis by regulating the FAK/ERK/S100A4 pathway. CONCLUSIONS: The results presented in this study show that JWH133 exerts a protective effect against pulmonary fibrosis by inhibiting the FAK/ERK/S100A4 pathway.Therefore, JWH133 holds promise as a potential therapeutic target for pulmonary fibrosis.

Three-Dimensional-QSAR and Relative Binding Affinity Estimation of Focal Adhesion Kinase Inhibitors.

Precise binding affinity predictions are essential for structure-based drug discovery (SBDD). Focal adhesion kinase (FAK) is a member of the tyrosine kinase protein family and is overexpressed in a variety of human malignancies. Inhibition of FAK using small molecules is a promising therapeutic option for several types of cancer. Here, we conducted computational modeling of FAK-targeting inhibitors using three-dimensional structure-activity relationship (3D-QSAR), molecular dynamics (MD), and hybrid topology-based free energy perturbation (FEP) methods. The structure-activity relationship (SAR) studies between the physicochemical descriptors and inhibitory activities of the chemical compounds were performed with reasonable statistical accuracy using CoMFA and CoMSIA. These are two well-known 3D-QSAR methods based on the principle of supervised machine learning (ML). Essential information regarding residue-specific binding interactions was determined using MD and MM-PB/GBSA methods. Finally, physics-based relative binding free energy (ΔΔGRBFEA→B) terms of analogous ligands were estimated using alchemical FEP simulation. An acceptable agreement was observed between the experimental and computed relative binding free energies. Overall, the results suggested that using ML and physics-based hybrid approaches could be useful in synergy for the rational optimization of accessible lead compounds with similar scaffolds targeting the FAK receptor.

The dual FAK-HDAC inhibitor MY-1259 displays potent activities in gastric cancers in vitro and in vivo.

Epigenetic regulation and Focal adhesion kinase (FAK) are considered to be two important targets for the development of antitumor drugs. Studies have shown that the combination of FAK and HDAC inhibitors could exhibit synergistic effects in a subset of cancer cells in vitro and in vivo. At present, there are few reports on dual target inhibitors of FAK and HDAC. Here, we first reported a new compound MY-1259 as a dual FAK and HDAC6 inhibitor, which exhibited efficient treatment effects on gastric cancers in vitro and in vivo. MY-1259 exhibited potent inhibitory activities against FAK (IC50 = 132 nM) and HDAC6 (IC50 = 16 nM). Notably, MY-1259 showed selective inhibitory potency on HDAC6 over HDAC1, HDAC2 and HDAC3. In addition, MY-1259 could potently inhibit the proliferative activities of MGC-803 and BGC-823 cells (IC50 = 3.91 and 15.46 nM, respectively, using flow cytometry counting), induce cell apoptosis, and cellular senescence. MY-1259 could effectively down-regulate the levels of Ac-Histone H3 and Ac-α-tubulin, and also inhibit the phosphorylation of FAK at three phosphorylation sites Y397, Y576/577 and Y925, thereby inhibiting the activation of ERK and AKT/mTOR. MY-1259 exhibited more effective antitumor effect in vivo than the HDAC inhibitor SAHA and FAK inhibitor TAE-226 alone or in combination, showing the advantages of FAK/HDAC dual inhibitors in the treatment of gastric cancers. Therefore, the results in this work suggested that inhibition of FAK and HDAC by MY-1259 might represent a promising strategy for the treatment of gastric cancers.

Low-dose X-ray irradiation combined with FAK inhibitors improves the immune microenvironment and confers sensitivity to radiotherapy in pancreatic cancer.

Radiation therapy offers limited clinical benefits for patients with pancreatic cancer, partly as a result of the predominantly immunosuppressive microenvironment characteristic of this specific type of cancer. A large number of abnormal blood vessels and high-density fibrous matrices in pancreatic cancer will lead to hypoxia within tumor tissue and hinder immune cell infiltration. We used low-dose X-ray irradiation, also known as low-dose radiation therapy (LDRT), to normalize the blood vessels in pancreatic cancer, while simultaneously administering an inhibitor of focal adhesion kinase (FAK) to reduce pancreatic cancer fibrosis. We found that this treatment successfully reduced pancreatic cancer hypoxia, increased immune cell infiltration, and increased sensitivity to radiation therapy for pancreatic cancer.

Recent progress on FAK inhibitors with dual targeting capabilities for cancer treatment.

Focal adhesion kinase (FAK, also known as PTK2) is a tyrosine kinase that regulates integrin and growth factor signaling pathways and is involved in the migration, proliferation and survival of cancer cells. FAK is a promising target for cancer treatment. Many small molecule FAK inhibitors have been identified and proven in both preclinical and clinical studies to be effective inhibitors of tumor growth and metastasis. There are many signaling pathways, such as those involving FAK, Src, AKT, MAPK, PI3K, and EGFR/HER-2, that provide survival signals in cancer cells. Dual inhibitors that simultaneously block FAK and another factor can significantly improve efficacy and overcome some of the shortcomings of single-target inhibitors, including drug resistance. In this review, the antitumor mechanisms and research status of dual inhibitors of FAK and other targets, such as Pyk2, IGF-IR, ALK, VEGFR-3, JAK2, EGFR, S6K1, and HDAC2, are summarized, providing new ideas for the development of effective FAK dual-target preparations.

Identification of novel and potent PROTACs targeting FAK for non-small cell lung cancer: Design, synthesis, and biological study.

The intracellular non-receptor tyrosine protein kinase Focal adhesion kinase (FAK) is a key signalling regulator, which mediates tumor survival, invasion, metastasis, and angiogenesis through its kinase catalytic functions and non-kinase scaffolding functions. Previous efforts have clarified that it is crucial to address both FAK kinase and scaffolding functions instead of just inhibiting FAK kinase activity because it may be insufficient to completely block FAK signaling. Proteolysis targeting chimera (PROTAC) technology is a method of targeting a specific protein and inducing its degradation in the cell, which can simultaneously eliminate both kinase-dependent enzymatic functions and scaffolding functions. In current study, we designed and synthesized a series of novel FAK PROTACs and the optimal PROTAC B5 exhibited potent FAK affinity with an IC50 value of 14.9 nM. Furthermore, in A549 cells, PROTAC B5 presented strong FAK degradation activity (86.4% degradation @ 10 nM), powerful antiproliferative activity (IC50 = 0.14 ± 0.01 µM) and inhibited cell migration and invasion in a concentration-dependent manner. Additionally, the in vitro preliminary drug-like properties evaluation of PROTAC B5 showed outstanding plasma stability and moderate membrane permeability. Together, current results provided a promising FAK PROTAC B5 as lead compound for cancer-related drug discovery and FAK-degradation functions exploration in biological systems.

FAK Shutdown: Consequences on Epithelial Morphogenesis and Biomarker Expression Involving an Innovative Biomaterial for Tissue Regeneration.

By employing an innovative biohybrid membrane, the present study aimed at elucidating the mechanistic role of the focal adhesion kinase (FAK) in epithelial morphogenesis in vitro over 4, 7, and 10 days. The consequences of siRNA-mediated FAK knockdown on epithelial morphogenesis were monitored by quantifying cell layers and detecting the expression of biomarkers of epithelial differentiation and homeostasis. Histologic examination of FAK-depleted samples showed a significant increase in cell layers resembling epithelial hyperplasia. Semiquantitative fluorescence imaging (SQFI) revealed tissue homeostatic disturbances by significantly increased involucrin expression over time, persistence of yes-associated protein (YAP) and an increase of keratin (K) 1 at day 4. The dysbalanced involucrin pattern was underscored by ROCK-IISer1366 activity at day 7 and 10. SQFI data were confirmed by quantitative PCR and Western blot analysis, thereby corroborating the FAK shutdown-related expression changes. The artificial FAK shutdown was also associated with a significantly higher expression of filaggrin at day 10, sustained keratinocyte proliferation, and the dysregulated expression of K19 and vimentin. These siRNA-induced consequences indicate the mechanistic role of FAK in epithelial morphogenesis by simultaneously considering prospective biomaterial-based epithelial regenerative approaches.

Tumor Necrosis Factor-alpha utilizes MAPK/NFκB pathways to induce cholesterol-25 hydroxylase for amplifying pro-inflammatory response via 25-hydroxycholesterol-integrin-FAK pathway.

Exaggerated inflammatory response results in pathogenesis of various inflammatory diseases. Tumor Necrosis Factor-alpha (TNF) is a multi-functional pro-inflammatory cytokine regulating a wide spectrum of physiological, biological, and cellular processes. TNF induces Focal Adhesion Kinase (FAK) for various activities including induction of pro-inflammatory response. The mechanism of FAK activation by TNF is unknown and the involvement of cell surface integrins in modulating TNF response has not been determined. In the current study, we have identified an oxysterol 25-hydroxycholesterol (25HC) as a soluble extracellular lipid amplifying TNF mediated innate immune pro-inflammatory response. Our results demonstrated that 25HC-integrin-FAK pathway amplifies and optimizes TNF-mediated pro-inflammatory response. 25HC generating enzyme cholesterol 25-hydroxylase (C25H) was induced by TNF via NFκB and MAPK pathways. Specifically, chromatin immunoprecipitation assay identified binding of AP-1 (Activator Protein-1) transcription factor ATF2 (Activating Transcription Factor 2) to the C25H promoter following TNF stimulation. Furthermore, loss of C25H, FAK and α5 integrin expression and inhibition of FAK and α5ß1 integrin with inhibitor and blocking antibody, respectively, led to diminished TNF-mediated pro-inflammatory response. Thus, our studies show extracellular 25HC linking TNF pathway with integrin-FAK signaling for optimal pro-inflammatory activity and MAPK/NFκB-C25H-25HC-integrin-FAK signaling network playing an essential role to amplify TNF dependent pro-inflammatory response. Thus, we have identified 25HC as the key factor involved in FAK activation during TNF mediated response and further demonstrated a role of cell surface integrins in positively regulating TNF dependent pro-inflammatory response.

Inhibiting Focal Adhesion Kinase Ameliorates Cyst Development in Polycystin-1-Deficient Polycystic Kidney Disease in Animal Model.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by numerous cysts originating from renal tubules and is associated with significant tubular epithelial cell proliferation. Focal adhesion kinase (FAK) promotes tumor growth by regulating multiple proliferative pathways. METHODS: We established the forskolin (FSK)-induced three-dimensional (3D) Madin-Darby Canine Kidney cystogenesis model and 8-bromoadenosine-3`,5`-cyclic monophosphate-stimulated cyst formation in ex vivo embryonic kidney culture. Cultured human renal cyst-lining cells (OX-161) and normal tubular epithelial cells were treated with FAK inhibitors or transfected with green fluorescent protein-tagged FAK mutant plasmids for proliferation study. Furthermore, we examined the role of FAK in two transgenic ADPKD animal models, the kidney-specific Pkd1 knockout and the collecting duct-specific Pkd1 knockout mouse models. RESULTS: FAK activity was significantly elevated in OX-161 cells and in two ADPKD mouse models. Inhibiting FAK activity reduced cell proliferation in OX-161 cells and prevented cyst growth in ex vivo and 3D cyst models. In tissue-specific Pkd1 knockout mouse models, FAK inhibitors retarded cyst development and mitigated renal function decline. Mechanically, FSK stimulated FAK activation in tubular epithelial cells, which was blocked by a protein kinase A (PKA) inhibitor. Inhibition of FAK activation by inhibitors or transfected cells with mutant FAK constructs interrupted FSK-mediated Src activation and upregulation of ERK and mTOR pathways. CONCLUSIONS: Our study demonstrates the critical involvement of FAK in renal cyst development, suggests that FAK is a potential therapeutic target in treating patients with ADPKD, and highlights the role of FAK in cAMP-PKA-regulated proliferation.

Synthesis and evaluation of FAK inhibitors with a 5-fluoro-7H-pyrrolo[2,3-d]pyrimidine scaffold as anti-hepatocellular carcinoma agents.

Focal adhesion kinase (FAK) is a ubiquitous intracellular non-receptor tyrosine kinase, which is involved in multiple cellular functions, including cell adhesion, migration, invasion, survival, and angiogenesis. In this study, a series of 7H-pyrrolo[2,3-d]pyrimidines were designed and synthesized according to the E-pharmacophores generated by docking a library of 667 fragments into the ATP pocket of the co-crystal complex of FAK and PF-562271 (PDB ID: 3BZ3). The 5-fluoro-7H-pyrrolo[2,3-d]pyrimidine derivatives demonstrated excellent activity against FAK and the cell lines SMMC7721 and YY8103. 2-((2-((3-(Acetamidomethyl)phenyl)amino)-5-fluoro-7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)-N-methylbenzamide (16c) was selected for further bioactivity evaluations in vivo, including preliminary pharmacokinetic profiling in rats and toxicity assays in mice, and tumor growth inhibition studies in a xenograft tumor model. The results showed that 16c did not affect the body weight gain of the animals up to a dose of 200 mg/kg, and significantly inhibited tumor growth with a tumor growth inhibition rate of 78.6% compared with the negative control group. Furthermore, phosphoantibody array analyses of a sample of the tumor suggested that 16c inhibited the malignant proliferation of hepatocellular carcinoma (HCC) cells through decreasing the phosphorylation in the FAK cascade.

Discovery of Novel 2,4-Dianilinopyrimidine Derivatives Containing 4-(Morpholinomethyl)phenyl and N-Substituted Benzamides as Potential FAK Inhibitors and Anticancer Agents.

Focal adhesion kinase (FAK) is responsible for the development and progression of various malignancies. With the aim to explore novel FAK inhibitors as anticancer agents, a series of 2,4-dianilinopyrimidine derivatives 8a-8i and 9a-9g containing 4-(morpholinomethyl)phenyl and N-substituted benzamides have been designed and synthesized. Among them, compound 8a displayed potent anti-FAK activity (IC50 = 0.047 ± 0.006 µM) and selective antiproliferative effects against H1975 (IC50 = 0.044 ± 0.011 µM) and A431 cells (IC50 = 0.119 ± 0.036 µM). Furthermore, compound 8a also induced apoptosis in a dose-dependent manner, arresting the cells in S/G2 phase and inhibiting the migration of H1975 cells, all of which were superior to those of TAE226. The docking analysis of compound 8a was performed to elucidate its possible binding modes with FAK. These results established 8a as our lead compound to be further investigated as a potential FAK inhibitor and anticancer agent.

Drug Discovery Targeting Focal Adhesion Kinase (FAK) as a Promising Cancer Therapy.

FAK is a nonreceptor intracellular tyrosine kinase which plays an important biological function. Many studies have found that FAK is overexpressed in many human cancer cell lines, which promotes tumor cell growth by controlling cell adhesion, migration, proliferation, and survival. Therefore, targeting FAK is considered to be a promising cancer therapy with small molecules. Many FAK inhibitors have been reported as anticancer agents with various mechanisms. Currently, six FAK inhibitors, including GSK-2256098 (Phase I), VS-6063 (Phase II), CEP-37440 (Phase I), VS-6062 (Phase I), VS-4718 (Phase I), and BI-853520 (Phase I) are undergoing clinical trials in different phases. Up to now, there have been many novel FAK inhibitors with anticancer activity reported by different research groups. In addition, FAK degraders have been successfully developed through "proteolysis targeting chimera" (PROTAC) technology, opening up a new way for FAK-targeted therapy. In this paper, the structure and biological function of FAK are reviewed, and we summarize the design, chemical types, and activity of FAK inhibitors according to the development of FAK drugs, which provided the reference for the discovery of new anticancer agents.

DS-1 Inhibits Migration and Invasion of Non-small-cell Lung Cancer Cells Through Suppression of Epithelial to Mesenchymal Transition and Integrin ß1/FAK Signaling.

BACKGROUND/AIM: Epithelial to mesenchymal transition (EMT), and focal adhesion kinase (FAK) facilitate lung cancer cell motility and survival. We, therefore, investigated the antimigratory effect of 3,4-dihydroxy-5,4'-dimethoxybibenzyl (DS-1) on human lung cancer cells. MATERIALS AND METHODS: Cell viability and proliferation were examined by the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide assay. Filopodia formation, migration, and anchorage-independent growth assays were performed to assess metastatic behaviors while EMT-related proteins, integrins, and FAK-RhoA pathway were evaluated by western blot analysis. RESULTS: We found that DS-1 significantly inhibited the proliferation of lung cancer cells compared to the control. The aggressive behavior of cancer cells, including migration and invasion, was significantly reduced by DS-1. Anchorage-independent growth analysis provided evidence that DS-1 suppressed the growth and survival of cancer cells in detached conditions as indicated by the significant reduction in size and number of colonies. With regard to the mechanisms involved, we found that DS-1-suppressed EMT, as indicated by the reduction of EMT markers, namely N-cadherin, SNAIL and SLUG, and increased levels of the epithelial marker, E-cadherin. In addition, DS-1 was shown to reduce the level of integrin ß1 protein and FAK activation. CONCLUSION: DS-1 suppressed lung cancer metastasis via suppressing EMT, integrin ß1 expression and FAK-related signaling.

Novel imidazo[2,1-b]thiazole-based anticancer agents as potential focal adhesion kinase inhibitors: Synthesis, in silico and in vitro evaluation.

The purpose of this study was to synthesize imidazo[2,1-b]thiazole derivatives, characterize them with spectroscopical techniques and investigate for cytotoxic and apoptotic effects on glioma C6 cancer cell line. The in vitro anticancer activities were also investigated against focal adhesion kinase. Most of the compounds, particularly the derivatives carrying 3-oxo-1-tiya-4-azaspiro[4.5]decane moiety, exhibited higher or comparable activities in comparison with the reference drug, cisplatin. Compounds with methyl, propyl, phenyl moieties at the eighth and second position of the spirothiazolidinone ring showed high FAK inhibitory activities. In addition, molecular docking studies shed light on the binding modes of the synthesized compounds. The critical interactions with amino acid residues located in the active site were revealed. The results obtained from both biological assay data and computational results might provide insight into developing new inhibitors against focal adhesion kinase.

Recent Advances of Small Molecule Focal Adhesion Kinase (FAK) Inhibitors as Promising Anticancer Therapeutics.

Focal Adhesion Kinase (FAK) is a non-receptor tyrosine kinase involved in the process of cell proliferation, survival, migration, and invasion. It has become a promising therapeutic target for the treatment of human metastatic cancers due to its overexpression and/or activation in multiple cancer types. Since FAK is emerging as a potential cancer target because of its overexpression at both the transcriptional and translational level in cancer, different types of FAK inhibitors with diversified scaffolds have been discovered in the past few years. In this review, the progress of recently discovered small molecule FAK inhibitors was summarized. Major efforts have been focused on the rational design and synthesis of small molecule FAK inhibitors, and their structure-activity relationship (SAR) analysis wasalso discussed. Among them, while type I inhibitors remain as the major focuses, type II inhibitors and novel allosteric FAK inhibitors (type III inhibitors) have been developed to improve both potency and selectivity. Meanwhile, novel strategies, such as targeting FAK using inhibitors of protein-protein interactions, were also discovered. Lastly, some insights and perspectives on the future development of FAK inhibitors as anticancer therapeutics have been provided.

EB1 Restricts Breast Cancer Cell Invadopodia Formation and Matrix Proteolysis via FAK.

Regulation of microtubule dynamics by plus-end tracking proteins (+TIPs) plays an essential role in cancer cell migration. However, the role of +TIPs in cancer cell invasion has been poorly addressed. Invadopodia, actin-rich protrusions specialized in extracellular matrix degradation, are essential for cancer cell invasion and metastasis, the leading cause of death in breast cancer. We, therefore, investigated the role of the End Binding protein, EB1, a major hub of the +TIP network, in invadopodia functions. EB1 silencing increased matrix degradation by breast cancer cells. This was recapitulated by depletion of two additional +TIPs and EB1 partners, APC and ACF7, but not by the knockdown of other +TIPs, such as CLASP1/2 or CLIP170. The knockdown of Focal Adhesion Kinase (FAK) was previously proposed to similarly promote invadopodia formation as a consequence of a switch of the Src kinase from focal adhesions to invadopodia. Interestingly, EB1-, APC-, or ACF7-depleted cells had decreased expression/activation of FAK. Remarkably, overexpression of wild type FAK, but not of FAK mutated to prevent Src recruitment, prevented the increased degradative activity induced by EB1 depletion. Overall, we propose that EB1 restricts invadopodia formation through the control of FAK and, consequently, the spatial regulation of Src activity.