Focal Adhesion Kinase Inhibitor Research Articles

FAK-p38 signaling serves as a potential target for reverting matrix stiffness-modulated liver sinusoidal endothelial cell defenestration

Liver sinusoidal endothelial cells (LSECs) are highly specific endothelial cells which play an essential role in the maintenance of liver homeostasis. During the progression of liver fibrosis, matrix stiffening promotes LSEC defenestration, however, the underlying mechanotransduction mechanism remains poorly understood. Here, we applied stiffness-tunable hydrogels to assess the matrix stiffening-induced phenotypic changes in primary mouse LSECs. Results indicated that increased stiffness promoted LSEC defenestration through cytoskeletal reorganization. LSECs sensed the increased matrix stiffness via focal adhesion kinase (FAK), leading to the activation of p38-mitogen activated protein kinase activated protein kinase 2 (MK2) pathway, thereby inducing actin remodeling via LIM Kinase 1 (LIMK1) and Cofilin. Interestingly, inhibition of FAK or p38-MK2 pathway was able to effectively restore the fenestrae to a certain degree in LSECs isolated from early to late stages of liver fibrosis mice. Thus, this study highlights the impact of mechanotransduction in LSEC defenestration, and provides novel insights for potential therapeutic interventions for liver fibrosis.

Annotation of CD8+ T-cell function via ICAM-1 imaging identifies FAK inhibition as an adjuvant to augment the antitumor immunity of radiotherapy.

Background: Radiotherapy (RT) may trigger systemic antitumor immunity, manifesting as regression of non-irradiated lesions (abscopal effect). Intracellular adhesion molecule-1 (ICAM-1) is a key molecule involved in the abscopal effect of RT. However, the specific function of ICAM-1 in CD8+ T cells during antitumor immune responses remains unclear. Herein, we investigated whether noninvasive imaging of ICAM-1 can be used to annotate CD8+ T-cell function, thereby better selecting combinational therapy to enhance the antitumor immunity induced by RT. Methods: Using knockout mouse models, we investigated the role of ICAM-1 expressed on CD8+ T cells in the antitumor immunity of RT and conducted drug screening guided by ICAM-1-targeted noninvasive imaging. Results: The systemic antitumor effect of RT relies on the expression of ICAM-1 on CD8+ T cells. ICAM-1 expression is essential for CD8+ T-cell activation, proliferation, and effector function. Noninvasive annotation of the proliferation and effector function of CD8+ T cells by ICAM-1-targeted imaging identified VS-6063, a focal adhesion kinase inhibitor, as a new adjuvant to augment systemic antitumor immunity of RT in an immunologically "cold" tumor model. Mechanistically, VS-6063 overcomes the physical barriers in tumors and promotes the migration and infiltration of CD8+ T cells primed by RT into distant tumors. Conclusion: Our findings highlight that molecular imaging of ICAM-1 levels provides a dynamic readout of the proliferation and effector function of tumor-infiltrating CD8+ T cells, which facilitates the high-throughput exploitation of new combinational drugs to maximize the systemic antitumor effect of RT.

Therapeutic benefit of the dual ALK/FAK inhibitor ESK440 in ALK-driven neuroblastoma

Neuroblastoma (NB) is a predominantly pediatric cancer with greater than 90% of cases arising in children under the age of five. More than half of patients have metastases detected at diagnosis, and high-risk disease is associated with five-year survival rates of only 50–60 %. Standard therapy involves highly toxic chemotherapy, surgery, radiation, and immunotherapy, and less toxic, more specific targeted therapies are urgently needed. Genomic studies have identified common driver aberrations in high-risk NB, such as MYCN amplification. In addition, a proportion of high-risk patients harbor amplification or activating mutations in anaplastic lymphoma kinase (ALK), and co-occurrence of ALK mutations and MYCN amplification have been associated with aggressive disease. In this study, we analyzed the efficacy of a Phase Ia-cleared, orally bioavailable dual ALK and focal adhesion kinase (FAK) inhibitor, ESK440, in multiple preclinical NB models. ESK440 potently inhibited proliferation of NB cell lines, with increased sensitivity in cell lines harboring ALK aberrations. ALK, FAK, and downstream target activation were rapidly decreased upon ESK440 treatment, and this was associated with impaired cellular migration and invasion. Importantly, ESK440 treatment also decreased MYCN levels. NB cell line and patient-derived xenograft studies showed significant reduction in tumor growth in ESK440-treated mice with no signs of toxicity. In certain NB models, ESK440 showed comparable or enhanced efficacy to lorlatinib, another clinical ALK inhibitor, and a lorlatinib-resistant cell line (COG-N-561 LR) retained sensitivity to ESK440. These preclinical results indicate that ESK440 is a promising targeted agent for ALK-driven NB and support future clinical studies to evaluate its efficacy in NB patients.

Atractylenolide II combined with Interferon-γ synergistically ameliorates colorectal cancer progression in vivo and in vitro by blocking the NF-kB p65/PD-L1 pathway.

Purpose: Atractylodes macrocephala Koidz is a widely used classical traditional Chinese herbal medicine, that has shown remarkable efficacy in cancers. Colorectal cancer (CRC) is the most common malignant tumor globally. Interferon (IFN)-γ, a prominent cytokine involved in anti-tumor immunity that has cytostatic, pro-apoptotic, and immune-stimulatory properties for the detection and removal of transformed cells. Atractylenolides-II (AT-II) belongs to the lactone compound that is derived from Atractylodes macrocephala Koidz with anti-cancer activity. However, whether AT-II combined with IFN-γ modulates CRC progression and the underlying mechanisms remain unclear. The present study aimed to elucidate the efficacy and pharmaceutical mechanism of action of AT-II combined with IFN-γ synergistically against CRC by regulating the NF-kB p65/PD-L1 signaling pathway. Methods: HT29 and HCT15 cells were treated with AT-II and IFN-γ alone or in combination and cell viability, migration, and invasion were then analyzed using Cell Counting Kit-8 (CCK-8) and Transwell assays, respectively. Furthermore, the underlying mechanism was investigated through western blot assay. The role of AT-II combined with IFN-γ on tumor growth and lung metastases was estimated in vivo. Finally, the population of lymphocytes in tumor tissues of lung metastatic C57BL/6 mice and the plasma cytokine levels were confirmed by flow cytometry and enzyme-linked immunosorbent assay (ELISA). Results: AT-II or the combination IFN-γ significantly inhibited the growth and migration abilities of CRC cells in vitro and in vivo. The biological mechanisms behind the beneficial effects of AT-II combined with IFN-γ were also measured and inhibition of p38 MAPK, FAK, Wnt/β-catenin, Smad, and NF-kB p65/PD-L1 pathways was observed. Moreover, AT-II combined with IFN-γ significantly inhibited HCT15 xenograft tumor growth and lung metastases in C57BL/6 mice, which was accompanied by lymphocyte infiltration into the tumor tissues and inflammatory response inactivation. Conclusions: The results showed that the AT-II in combination with IFN-γ could be used as a potential strategy for tumor immunotherapy in CRC. More importantly, the mechanism by which AT-II suppressed CRC progressions was by inhibiting the NF-kB p65/PD-L1 signal pathway.

Sustained intestinal epithelial monolayer wound closure after transient application of a FAK-activating small molecule.

M64HCl, which has drug-like properties, is a water-soluble Focal Adhesion Kinase (FAK) activator that promotes murine mucosal healing after ischemic or NSAID-induced injury. Since M64HCl has a short plasma half-life in vivo (less than two hours), it has been administered as a continuous infusion with osmotic minipumps in previous animal studies. However, the effects of more transient exposure to M64HCl on monolayer wound closure remained unclear. Herein, we compared the effects of shorter M64HCl treatment in vitro to continuous treatment for 24 hours on monolayer wound closure. We then investigated how long FAK activation and downstream ERK1/2 activation persist after two hours of M64HCl treatment in Caco-2 cells. M64HCl concentrations immediately after washing measured by mass spectrometry confirmed that M64HCl had been completely removed from the medium while intracellular concentrations had been reduced by 95%. Three-hour and four-hour M64HCl (100 nM) treatment promoted epithelial sheet migration over 24 hours similar to continuous 24-hour exposure. 100nM M64HCl did not increase cell number. Exposing cells twice with 2-hr exposures of M64HCl during a 24-hour period had a similar effect. Both FAK inhibitor PF-573228 (10 μM) and ERK kinase (MEK) inhibitor PD98059 (20 μM) reduced basal wound closure in the absence of M64HCl, and each completely prevented any stimulation of wound closure by M64HCl. Rho kinase inhibitor Y-27632 (20 μM) stimulated Caco-2 monolayer wound closure but no further increase was seen with M64HCl in the presence of Y-27632. M64HCl (100 nM) treatment for 3 hours stimulated Rho kinase activity. M64HCl decreased F-actin in Caco-2 cells. Furthermore, a two-hour treatment with M64HCl (100 nM) stimulated sustained FAK activation and ERK1/2 activation for up to 16 and hours 24 hours, respectively. These results suggest that transient M64HCl treatment promotes prolonged intestinal epithelial monolayer wound closure by stimulating sustained activation of the FAK/ERK1/2 pathway. Such molecules may be useful to promote gastrointestinal mucosal repair even with a relatively short half-life.

The protective role of chemokines 12 and chemokines 4 by mediating interleukin-6 in delayed diabetic foot wound healing

Refractory diabetic foot ulcer is commonly encountered in clinical practice and it is hardly cured with a long duration of treatment and a high expense, as such problem involves multiple disciplines. Therefore, in case of refractory wounds, it is necessary to first analyze the causes, general or local. Immunohistochemistry (IHC) was conducted to determine α-SMA, chemokines 12 (CXCL12) and chemokines 4 (CXCR4) levels in pancreatic tissues and distant normal pancreatic tissues. Cells were treated with recombinant human CXCL12 (rhCXCL12) or the CXCR4 antagonist AMD3100. After treatment, Western blot determined FAK-AKT and ERK1/2 expression in islet cells, whilst ELISA detected the content of IL-6 and IL-8. rhCXCL12 increased the expression and secretion of Interleukin-6 (IL-6) time- and dose-dependently. But the advent of CXCR4 antagonist abrogated the protective effect of rhCXCL12. rhCXCL12 exhibited a protective effect on apoptosis, but this effect was abrogated by down-regulation of IL-6 with AMD3100. In addition, rhCXCL12 increased the phosphorylation of FAK, ERK1/2, AKT, and P38 and inhibition of FAK inhibited IL-6 expression. FAK inhibition almost completely blocked CXCL12-induced activation. This study demonstrates that CXCL12/CXCR4 pathway mediates the expression of IL-6 to enhance healing of refractory diabetic foot wounds by down-regulating the FAK pathway.

Focal adhesion kinase and its epigenetic interactors as diagnostic and therapeutic hints for pediatric hepatoblastoma.

Hepatoblastoma (HB) is the most common pediatric hepatic malignancy. Despite the progress in HB treatment, investigating HB pathomechanisms to optimize stratification and therapies remains a focal point to improve the outcome for high-risk patients. Here, we pointed to explore the impact of these mechanisms in HB. An observational study was performed on liver samples from a cohort of 17 patients with a diagnosis of HB and two normal liver samples. The in vitro experiments were executed on the Huh6 human HB cell line treated with the FAK inhibitor TAE226. Our results highlight a significant up-regulation of mRNA and protein expression of FAK in livers from HB with respect to normal livers. The increased protein expression of total and Tyr397 phosphorylated FAK (pTyr397FAK) was significantly correlated with the expression of some epigenetic regulators of histone H3 methylation and acetylation. Of note, the expression of pTyr397FAK, N-methyltransferase enzyme (EZH2) and tri-methylation of the H3K27 residue correlated with tumor size and alpha-fetoprotein (AFP) levels. Finally, TAE226 caused a significant reduction of pTyr397FAK, epigenetic regulators, AFP, EPCAM, OCT4, and SOX2, in association with anti-proliferative and pro-apoptotic effects on HB cells. Our results suggest a role of FAK in HB that requires further investigations mainly focused on the exploration of its effective diagnostic and therapeutic translatability.

Combining QSAR techniques, molecular docking, and molecular dynamics simulations to explore anti-tumor inhibitors targeting Focal Adhesion Kinase

Focal Adhesion Kinase (FAK) is an important target for tumor therapy and is closely related to tumor cell genesis and progression. In this paper, we selected 46 FAK inhibitors with anticancer activity in the pyrrolo pyrimidine backbone to establish 3D/2D-QSAR models to explore the relationship between inhibitory activity and molecular structure. We have established two ideal models, namely, the Topomer CoMFA model (= 0.715, = 0.984) and the Holographic Quantitative Structure-Activity Relationship (HQSAR) model (= 0.707, = 0.899). Both models demonstrate excellent external prediction capabilities.Based on the QSAR results, we designed 20 structurally modified novel compounds, which were subjected to molecular docking and molecular dynamics studies, and the results showed that the new compounds formed many robust interactions with residues within the active pocket and could maintain stable binding to the receptor proteins. This study not only provides a powerful screening tool for designing novel FAK inhibitors, but also presents a series of novel FAK inhibitors with high micromolar activity that can be used for further characterization. It provides a reference for addressing the shortcomings of drug metabolism and drug resistance of traditional FAK inhibitors, as well as the development of novel clinically applicable FAK inhibitors. Communicated by Ramaswamy H. Sarma

The E156K mutation in the CRYAA gene affects the epithelial–mesenchymal transition and migration of human lens epithelial cells

PurposeTo investigated the biological effects of E156K-mutated αA-crystallin (CRYAA) in human lens epithelial cells (HLECs). MethodsFLAG-tagged, human, full-length, wild-type (WT), or E156K-mutated CRYAA was expressed in HLECs under CRYAA knockdown. CRYAA expression was determined by quantitative reverse transcription polymerase chain reaction and western blotting (WB). Rhodamine cytoskeleton staining was used to observe the changes in cell morphology following transfection with WT or E156K-mutated CRYAA plasmids. WB was performed to assess the expression of markers related to epithelial–mesenchymal transition (EMT) and migration. ResultsRhodamine cytoskeleton staining revealed changes in the morphology of cells transfected with E156K-mutated CRYAA and opposite responses occurred after treatment with a β-catenin inhibitor. Cells transfected with E156K-mutated CRYAA expressed remarkably higher levels of the mesenchymal biomarkers N-cadherin and vimentin but decreased levels of the epithelial biomarker E‐cadherin, whereas opposite trends were observed in cells treated with the β-catenin inhibitor, ICG001. The migratory capability of E156K-mutated CRYAA cells was significantly greater than that of WT cells (P < 0.001). This effect was accompanied by significantly increased expression levels of phosphorylated (p)-focal adhesion kinase (FAK) and p-Src. These changes were decreased significantly by treatment with FAK and Src inhibitors. ConclusionE156K-mutated CRYAA induced EMT, in which the HLECs lost cell polarity, and acquired a mesenchymal phenotype with greater migratory capability. These biological effects may be associated with activation of the Wnt/β-Catenin and FAK/Src signaling pathways.

Inhibition of focal adhesion kinase 2 results in a macrophage polarization shift to M2 which attenuates local and systemic inflammation and reduces heterotopic ossification after polysystem extremity trauma.

Heterotopic ossification (HO) is a complex pathology often observed in combat injured casualties who have sustained severe, high energy polytraumatic extremity injuries. Once HO has developed, prophylactic therapies are limited outside of surgical excision. Tourniquet-induced ischemia injury (IR) exacerbates trauma-mediated musculoskeletal tissue injury, inflammation, osteogenic progenitor cell development and HO formation. Others have shown that focal adhesion kinase-2 (FAK2) plays a key role in regulating early inflammatory signaling events. Therefore, we hypothesized that targeting FAK2 prophylactically would mitigate extremity trauma induced IR inflammation and HO formation. We tested whether the continuous infusion of a FAK2 inhibitor (Defactinib, PF-573228; 6.94 µg/kg/min for 14 days) can mitigate ectopic bone formation (HO) using an established blast-related extremity injury model involving femoral fracture, quadriceps crush injury, three hours of tourniquet-induced limb ischemia, and hindlimb amputation through the fracture site. Tissue inflammation, infiltrating cells, osteogenic progenitor cell content were assessed at POD-7. Micro-computed tomography imaging was used to quantify mature HO at POD-56. In comparison to vehicle control-treated rats, FAK2 administration resulted in no marked wound healing complications or weight loss. FAK2 treatment decreased HO by 43%. At POD-7, marked reductions in tissue proinflammatory gene expression and assayable osteogenic progenitor cells were measured, albeit no significant changes in expression patterns of angiogenic, chondrogenic and osteogenic genes. At the same timepoint, injured tissue from FAK-treated rats had fewer infiltrating cells. Additionally, gene expression analyses of tissue infiltrating cells resulted in a more measurable shift from an M1 inflammatory to an M2 anti-inflammatory macrophage phenotype in the FAK2 inhibitor-treated group. Our findings suggest that FAK2 inhibition may be a novel strategy to dampen trauma-induced inflammation and attenuate HO in patients at high risk as a consequence of severe musculoskeletal polytrauma.

Loss of MTA2-mediated downregulation of PTK7 inhibits hepatocellular carcinoma metastasis progression by modulating the FAK-MMP7 axis.

The expression of metastasis tumor-associated protein 2 (MTA2) and protein tyrosine kinase 7 (PTK7) is associated with hepatocellular carcinoma (HCC) progression. However, the functional effect and mechanism through which MTA2 regulates PTK7-mediated HCC progression remains unclear. Here, we found that MTA2 knockdown significantly down-regulated PTK7 expression in HCC cells (SK-Hep-1 and PLC/PRF/5). Data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases show that the PTK7 expression level was higher in HCC tissues than in normal liver tissues. In HCC patients, the PTK7 expression level clearly correlated with tumor stage and grade, lower overall survival (OS) correlated positively with MTA2 level, and PTK7 expression acted as a downstream factor for MTA2 expression. In addition, matrix metalloproteinase 7 (MMP7) expression was closely regulated by PTK7, and the mRNA and protein expression levels of MTA2 and PTK7 correlated positively with lower OS. MMP7 downregulation by PTK7 knockdown clearly decreased the migration and invasion abilities of HCC cells. In HCC cells, recombinant human MMP7 reversed the PTK7 knockdown-induced suppression of migration and invasion. Furthermore, deactivation of FAK using siFAK or FAK inhibitor (PF-573228, PF) synergistically contributed to PTK7 knockdown-inhibited FAK activity, MMP7 expression, and the migration and invasion abilities of HCC cells. Collectively, our findings show that PTK7 mediates HCC progression by regulating the MTA2-FAK-MMP7 axis and may be a diagnostic value for HCC patients.

Kisspeptin-10 increases collagen content in the myocardium by focal adhesion kinase activity

The aim of the study was to evaluate the role of kisspeptin-10 (KiSS-10) in the regulation of collagen content in cardiac fibroblasts. An attempt was also made to describe the mechanism of the effect of KiSS-10 on collagen metabolism. The studies indicate that kisspeptin-10 significantly increases the content of intracellular collagen in the myocardium. KiSS-10 also elevates the level of phosphorylated focal adhesion kinase (FAK) in human cardiac fibroblasts. The inhibition of FAK negates the stimulatory effect of KiSS-10 on collagen deposition in vitro. These changes correlate with an increase in the level of propeptides of procollagen type I (PICP) and III (PIIICP) in fibroblast culture medium and mouse PIIICP in serum. Moreover, this hormone inhibits the release of metalloproteinases (MMP-1,-2,-9) and elevates the secretion of their tissue inhibitors (TIMP-1,-2,-4). KiSS-10 also enhances the expression of α1 chains of procollagen type I and III in vitro. Thus, KiSS-10 is involved in the regulation of collagen metabolism and cardiac fibrosis. Augmentation of collagen deposition by KiSS-10 is dependent on the protein synthesis elevation, inhibition of MMPs activity (increase of TIMPs release) or decrease of MMPs concentration. The profibrotic activity of KiSS-10 is mediated by FAK and is not dependent on TGF-β1.

GMI, a Ganoderma microsporum protein, abolishes focal adhesion network to reduce cell migration and metastasis of lung cancer

BackgroundCancer metastasis is a major cause of cancer-related deaths, emphasizing the urgent need for effective therapies. Although it has been shown that GMI, a fungal protein from Ganoderma microsporum, could suppress primary tumor growth in a wide spectrum of cancer types, it is still unclear whether GMI exhibits anti-metastasis properties, particularly in lung cancers. Further investigation is needed. Aims and objectivesThe objective of this study is to investigate the potential inhibitory effects of GMI on lung cancer metastasis in vivo. Utilizing systematic and comprehensive approaches, our research aims to elucidate the underlying molecular mechanisms responsible for the anti-metastatic effects. Materials and methodsIn vitro migration and cell adhesion assays addressed the epithelial-to-mesenchymal transition (EMT)-related phenotype. Proteomic and bioinformatic analyses identified the GMI-regulated proteins and cellular responses. GMI-treated LLC1-bearing mice were analyzed using IVIS Spectrum to assess the anti-metastatic effect. Key findingsGMI inhibits EMT as well as cell migration. GMI disrupts cell adhesion and downregulates integrin, resulting in inhibition of phosphorylated FAK. GMI induces macropinocytosis and lysosome-mediated degradation of integrin αv, α5, α6 and β1. GMI downregulates Slug via inhibition of FAK activity, which in turn enhances expressions of epithelial-related markers and decreases cell mobility. Mechanistically, GMI-induced FAK inhibition engenders MDM2 expression and enhances MDM2/p21/Slug complex formation, leading to Slug degradation. GMI treatment reduces the metastatic pulmonary lesion and prolongs the survival of LLC1-bearing mice. SignificanceOur findings highlight GMI as a promising therapeutic candidate for metastatic lung cancers, offering potential avenues for further research and drug development.

DDDR-32. EVALUATING THE THERAPEUTIC EFFECTS OF SMALL MOLECULE INHIBITORS OF CDK4/6 AND FAK IN PRECLINICAL MENINGIOMA MODELS

Abstract BACKGROUND New therapies are needed for meningioma since treatment options are limited once patients have exhausted surgery and radiation. FAK, CDK4/6 and RAF/MEK represent potential targets because of synthetic lethality with NF2, loss of CDKN2A, and activation of MAPK signaling pathway in meningioma, respectively. The objective of this study was to evaluate the efficacy of targeting FAK, CDK4/6 and RAF/MEK as monotherapies and combination therapies in traditional and patient-derived cell lines and xenografts. METHODS In vitro, cell viability and proliferation assays were used to test abemaciclib (CDK4/6 inhibitor), defactinib (FAK inhibitor) and VS-6766 (RAF/MEK inhibitor) as monotherapy and in combination. To better recapitulate the meningioma microenvironment, targeted agents were evaluated with Matrigel, an artificial extracellular matrix. The efficacy of VS-4718 (in vivo formulation of defactinib) and abemaciclib were evaluated in a subcutaneous IOMM-lee meningioma model (having CDKN2A loss) in nude mice. Furthermore, we are establishing cell cultures and patient-derived cell and xenograft (PDX) models using freshly-resected tissue from patients with recurrent or high-grade (WHO grade 2-3) meningiomas. RESULTS In vitro evaluation identified the combination of defactinib with abemaciclib resulted in a synergistic decrease in cell viability relative to each monotherapy alone, while the combination of defactinib+VS-6766 was not beneficial. The presence of Matrigel enhanced the sensitivity of all three agents. In vivo, we observed improved survival in mice treated with abemaciclib vs control (45 days vs 26 days; p=0.03), as well as combination of VS-4718 + abemaciclib vs control (44 days vs 26 days; p=0.04, Gehan-Breslow-Wilcoxon test). We did not observe survival extension with VS-4718 monotherapy. Lastly, we successfully established an orthotopic meningioma PDX using a WHO Grade 3 tumor for evaluation of novel therapies in meningioma. CONCLUSION Abemaciclib showed promising efficacy in preclinical meningioma xenografts with CDKN2A loss. Studies to evaluate these therapies in other orthotopic models are underway.

A Nanodrug-Enabled chemosensitization of cancer stem cells against tumor progression and metastasis

Chemotherapy remains the primary treatment for tumors due to its systemic tumor-suppressing ability. However, the efficacy of chemotherapy is limited by drug resistance in cancer stem cells (CSCs), which play a crucial role in tumor progression and metastasis. In this study, we present a novel nanodrug that enhances the effectiveness of chemotherapy by simultaneously targeting CSCs in the tumor tissue and preventing tumor cells from transforming into CSCs. The nanodrug is formed through the self-assembly of doxorubicin (DOX) and the focal adhesion kinase (FAK) inhibitor PF-573228 (PF). Upon accumulation at the tumor site, DOX induces tumor cell death, while PF overcomes CSCs resistance to DOX by suppressing the level of tyrosine 397 phosphorylated FAK (FAK pY397) in CSCs. Furthermore, PF inhibits the acquisition of CSC phenotype in tumor cells by suppressing the process known as epithelial-mesenchymal transition (EMT). Consequently, the designed nanodrug exhibits a robust ability to address tumor progression and metastasis. This study provides a unique strategy to tackle the challenges posed by CSCs in cancer chemotherapy.

FTO facilitates cancer metastasis by modifying the m6A level of FAP to induce integrin/FAK signaling in non-small cell lung cancer

BackgroundEmerging evidence suggests the critical roles of N6-methyladenosine (m6A) RNA modification in tumorigenesis and tumor progression. However, the role of m6A in non-small cell lung cancer (NSCLC) is still unclear. This study aimed to explore the role of the m6A demethylase fat mass and obesity-associated protein (FTO) in the tumor metastasis of NSCLC.MethodsA human m6A epitranscriptomic microarray analysis was used to identify downstream targets of FTO. Quantitative real-time PCR (qRT‒PCR) and western blotting were employed to evaluate the expression levels of FTO and FAP in NSCLC cell lines and tissues. Gain-of-function and loss-of-function assays were conducted in vivo and in vitro to assess the effects of FTO and FAP on NSCLC metastasis. M6A-RNA immunoprecipitation (MeRIP), RNA immunoprecipitation (RIP), luciferase reporter assays, and RNA stability assays were used to explore the mechanism of FTO action. Co-immunoprecipitation (co-IP) assays were used to determine the mechanism of FAP in NSCLC metastasis.ResultsFTO was upregulated and predicted poor prognosis in patients with NSCLC. FTO promoted cell migration and invasion in NSCLC, and the FAK inhibitor defactinib (VS6063) suppressed NSCLC metastasis induced by overexpression of FTO. Mechanistically, FTO facilitated NSCLC metastasis by modifying the m6A level of FAP in a YTHDF2-dependent manner. Moreover, FTO-mediated metastasis formation depended on the interactions between FAP and integrin family members, which further activated the FAK signaling.ConclusionOur current findings provided valuable insights into the role of FTO-mediated m6A demethylation modification in NSCLC metastasis. FTO was identified as a contributor to NSCLC metastasis through the activation of the FAP/integrin/FAK signaling, which may be a potential therapeutic target for NSCLC.EwEnNquqUtx8DT1YGQrFDqVideo

High-throughput chemogenetic drug screening reveals PKC-RhoA/PKN as a targetable signaling vulnerability in GNAQ-driven uveal melanoma

Uveal melanoma (UM) is the most prevalent cancer of the eye in adults, driven by activating mutation of GNAQ/GNA11; however, there are limited therapies against UM and metastatic UM (mUM). Here, we perform a high-throughput chemogenetic drug screen in GNAQ-mutant UM contrasted with BRAF-mutant cutaneous melanoma, defining the druggable landscape of these distinct melanoma subtypes. Across all compounds, darovasertib demonstrates the highest preferential activity against UM. Our investigation reveals that darovasertib potently inhibits PKC as well as PKN/PRK, an AGC kinase family that is part of the "dark kinome." We find that downstream of the Gαq-RhoA signaling axis, PKN converges with ROCK to control FAK, a mediator of non-canonical Gαq-driven signaling. Strikingly, darovasertib synergizes with FAK inhibitors to halt UM growth and promote cytotoxic cell death invitro and in preclinical metastatic mouse models, thus exposing a signaling vulnerability that can be exploited as a multimodal precision therapy against mUM.

Co-targeting FAK and Gli1 inhibits the tumor-associated macrophages-released CCL22-mediated esophageal squamous cell carcinoma malignancy.

Esophageal squamous cell carcinoma (ESCC) is a frequently seen esophageal tumor type in China. Activation of signaling proteins and relevant molecular mechanisms in ESCC are partially explored, impairing the antitumor efficiency of targeted therapy in ESCC treatment. Tumor-associated macrophages (TAMs)-released C-C motif chemokine 22 (CCL22) can activate intratumoral focal adhesion kinase (FAK), thus promoting the progression of ESCC. Here, we demonstrated that highly secreted CCL22 by TAMs (CCL22-positive TAMs) induced ESCC cell stemness and invasion through facilitating transcriptional activity of intratumoral glioma-associated oncogene 1 (Gli1), a downstream effector for Hedgehog (HH) pathway. Mechanistically, FAK-activated protein kinase B (AKT) mediated Gli1 phosphorylation at its Ser112/Thr115/Ser116 sites and released Gli1 from suppressor of fused homolog, the endogenous inhibitor of Gli1 to activate downstream stemness-associated factors, such as SRY-box transcription factor 2 (SOX2), Nanog homeobox (Nanog), or POU class 5 homeobox (OCT4). Furthermore, inhibition of FAK activity by VS-4718, the FAK inhibitor, enhanced antitumor effect of GDC-0449, the HH inhibitor, both in xenografted models and in vitro assays. Clinically, CCL22/Gli1 axis is used to evaluate ESCC prognosis. Overall, our study establishes the communication of FAK with HH pathway and offers the novel mechanism related to Gli1 activation independent of Smoothened as well as the rationale for the anti-ESCC combination treatment.

Tumor removal limits prostate cancer cell dissemination in bone and osteoblasts induce cancer cell dormancy through focal adhesion kinase

BackgroundDisseminated tumor cells (DTCs) can enter a dormant state and cause no symptoms in cancer patients. On the other hand, the dormant DTCs can reactivate and cause metastases progression and lethal relapses. In prostate cancer (PCa), relapse can happen after curative treatments such as primary tumor removal. The impact of surgical removal on PCa dissemination and dormancy remains elusive. Furthermore, as dormant DTCs are asymptomatic, dormancy-induction can be an operational cure for preventing metastases and relapse of PCa patients.MethodsWe used a PCa subcutaneous xenograft model and species-specific PCR to survey the DTCs in various organs at different time points of tumor growth and in response to tumor removal. We developed in vitro 2D and 3D co-culture models to recapitulate the dormant DTCs in the bone microenvironment. Proliferation assays, fluorescent cell cycle reporter, qRT-PCR, and Western Blot were used to characterize the dormancy phenotype. We performed RNA sequencing to determine the dormancy signature of PCa. A drug repurposing algorithm was applied to predict dormancy-inducing drugs and a top candidate was validated for the efficacy and the mechanism of dormancy induction.ResultsWe found DTCs in almost all mouse organs examined, including bones, at week 2 post-tumor cell injections. Surgical removal of the primary tumor reduced the overall DTC abundance, but the DTCs were enriched only in the bones. We found that osteoblasts, but not other cells of the bones, induced PCa cell dormancy. RNA-Seq revealed the suppression of mitochondrial-related biological processes in osteoblast-induced dormant PCa cells. Importantly, the mitochondrial-related biological processes were found up-regulated in both circulating tumor cells and bone metastases from PCa patients’ data. We predicted and validated the dormancy-mimicking effect of PF-562,271 (PF-271), an inhibitor of focal adhesion kinase (FAK) in vitro. Decreased FAK phosphorylation and increased nuclear translocation were found in both co-cultured and PF-271-treated C4-2B cells, suggesting that FAK plays a key role in osteoblast-induced PCa dormancy.ConclusionsOur study provides the first insights into how primary tumor removal enriches PCa cell dissemination in the bones, defines a unique osteoblast-induced PCa dormancy signature, and identifies FAK as a PCa cell dormancy gatekeeper.

FAK Drives Resistance to Therapy in HPV-Negative Head and Neck Cancer in a p53-Dependent Manner.

Radiation and platinum-based chemotherapy form the backbone of therapy in human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC). We have correlated focal adhesion kinase (FAK/PTK2) expression with radioresistance and worse outcomes in these patients. However, the importance of FAK in driving radioresistance and its effects on chemoresistance in these patients remains unclear. We performed an in vivo shRNA screen using targetable libraries to identify novel therapeutic sensitizers for radiation and chemotherapy. We identified FAK as an excellent target for both radio- and chemosensitization. Because TP53 is mutated in over 80% of HPV-negative HNSCC, we hypothesized that mutant TP53 may facilitate FAK-mediated therapy resistance. FAK inhibitor increased sensitivity to radiation, increased DNA damage, and repressed homologous recombination and nonhomologous end joining repair in mutant, but not wild-type, TP53 HPV-negative HNSCC cell lines. The mutant TP53 cisplatin-resistant cell line had increased FAK phosphorylation compared with wild-type, and FAK inhibition partially reversed cisplatin resistance. To validate these findings, we utilized an HNSCC cohort to show that FAK copy number and gene expression were associated with worse disease-free survival in mutant TP53, but not wild-type TP53, HPV-negative HNSCC tumors. FAK may represent a targetable therapeutic sensitizer linked to a known genomic marker of resistance.