Focal Adhesion Kinase Inhibitor Research Articles

The Impact of the VEGF/VEGFR2/PI3K/AKT Signaling Axis on the Proliferation and Migration Abilities of Human Dental Pulp Stem Cells.

The potential therapeutic benefits of human dental pulp stem cells (HDPSCs) in dental regenerative medicine have been demonstrated. However, little is known about the molecular mechanisms regulating the biological characteristics of HDPSCs. The experiment aims to explore whether VEGF activates signaling pathways such as FAK, PI3K, Akt, and p38 in HDPSCs, and to investigate the molecular mechanisms by which VEGF influences proliferation and migration of HDPSCs. Normal and inflamed human dental pulp (HDP) samples were collected, and the levels of VEGF in HDP were assessed. HDPSCs were cultured and purified. HDPSCs were stimulated with lipopolysaccharide (LPS) at gradient concentrations, and real-time quantitative polymerase chain reaction (qPCR) was used to assess changes in VEGF mRNA. Gradient concentrations of VEGF were used to stimulate HDPSCs, and cell migration ability was evaluated through scratch assays and Transwell chamber experiments. Phosphorylation levels of FAK, AKT, and P38 were assessed using Western blotting. Inhibitors of VEGFR2, FAK, AKT, P38, and VEGF were separately applied to HDPSCs, and cell migration ability and phosphorylation levels of FAK, AKT, and P38 were determined. The results indicated significant differences in VEGF levels between normal and inflamed HDP tissues, with levels in the inflamed state reaching 435% of normal levels (normal: 87.91 ng/mL, inflamed: 382.76 ng/mL, P < 0.05). LPS stimulation of HDPSCs showed a significant increase in VEGF mRNA expression with increasing LPS concentrations (LPS concentrations of 0.01, 0.1, 1, and 10 μg/mL resulted in VEGF mRNA expressions of 181.2%, 274.2%, 345.8%, and 460.9%, respectively, P < 0.05). VEGF treatment significantly enhanced the migration ability of HDPSCs in Transwell chamber experiments, with migration rates increasing with VEGF concentrations (VEGF concentrations of 0, 1, 10, 20, 50, and 100 ng/mL resulted in migration rates of 8.41%, 9.34%, 21.33%, 28.41%, 42.87%, and 63.15%, respectively, P < 0.05). Inhibitors of VEGFR2, FAK, AKT, P38, and combined VEGF stimulation demonstrated significant migration inhibition, with migration rates decreasing to 8.31%, 12.64%, 13.43%, 18.32%, and 74.17%, respectively. The migration rate with combined VEGF stimulation showed a significant difference (P < 0.05). The analysis of phosphorylation levels revealed that VEGF stimulation significantly activated phosphorylation of FAK, AKT, and P38, with phosphorylation levels increasing with VEGF concentrations (P < 0.05). The VEGF/VEGFR2 signaling axis regulated the migration ability of HDPSCs through the FAK/PI3K/AKT and P38MAPK pathways. This finding highlighted not only the crucial role of VEGF in injury repair of HDPSCs but also provided important clues for a comprehensive understanding of the potential applications of this signaling axis in dental regenerative medicine.

Schisandra chinensis Bee Pollen Extract Inhibits Proliferation and Migration of Hepatocellular Carcinoma HepG2 Cells via Ferroptosis-, Wnt-, and Focal Adhesion-Signaling Pathways.

Bee pollen possesses favorable anticancer activities. As a medicinal plant source, Schisandra chinensis bee pollen (SCBP) possesses potential pharmacological properties, such as reducing cisplatin-induced liver injury, but its anti-liver cancer effect is still rarely reported. This paper aims to investigate the effect and mechanism of SCBP extract (SCBPE) on hepatocellular carcinoma HepG2 cells. The effect of SCBPE on cell proliferation and migration of HepG2 cells was evaluated based on MTT assay, morphology observation, or scratching assay. Furthermore, tandem mass tag-based quantitative proteomics was used to study the effect mechanisms. The mRNA expression levels of identified proteins were verified by RT-qPCR. Tandem mass tag-based quantitative proteomics showed that 61 differentially expressed proteins were obtained in the SCBPE group compared with the negative-control group: 18 significantly downregulated and 43 significantly upregulated proteins. Bioinformatic analysis showed the significantly enriched KEGG pathways were predominantly ferroptosis-, Wnt-, and hepatocellular carcinoma-signaling ones. Protein-protein interaction network analysis and RT-qPCR validation revealed SCBPE also downregulated the focal adhesion-signaling pathway, which is abrogated by PF-562271, a well-known inhibitor of FAK. This study confirmed SCBPE suppressed the cell proliferation and migration of hepatocellular carcinoma HepG2 cells, mainly through modulation of ferroptosis-, Wnt-, hepatocellular carcinoma-, and focal adhesion-signaling pathways, providing scientific data supporting adjuvant treatment of hepatocellular carcinoma using SCBP.

SPP1 promotes tumor progression in esophageal carcinoma by activating focal adhesion pathway.

Recurrence and metastasis are the major obstacles affecting the therapeutic efficacy and clinical outcomes for patients with esophageal carcinoma (ESCA). Secreted phosphoprotein 1 (SPP1) is considered as a hub gene in ESCA and is negatively associated with disease-free survival (DFS) in ESCA. However, the exact roles and underlying mechanisms remain elusive. This study aims to examine the roles of SPP1 on ESCA, and elucidate the potential mechanisms. Bioinformatics were used to analyze the expression of SPP1 in ESCA tissues, and its relations with clinicopathological characteristics and clinical prognosis in patients with ESCA based on The Cancer Genome Atlas (TCGA) dataset. Loss-of-function was conducted to examine the roles of SPP1 on malignant behaviors of ESCA cells by cell counting kit-8 (CCK8), plate clone, wound healing, and transwell assays. Gene set enrichment analysis (GSEA) was conducted to screen the pathways associated with SPP1 in ESCA. Then, the enriched pathway and the underlying mechanism were elucidated by western blotting, cell adhesion, and cell spreading assays. Lastly, Y15 [a specific inhibitor of focal adhesion kinase (FAK)] was used to examine its potential to inhibit tumor growth in ESCA cells. SPP1 was upregulated in ESCA tissues compared to the adjacent nontumorous tissues, which was closely associated with clinical stage, lymph node metastasis, histological subtype, and p53 mutation. A high expression of SPP1 indicated a poor clinical prognosis in patients with ESCA. The knockdown of SPP1 inhibited cell proliferative, migratory, and invasive capacities in ESCA cells. GSEA indicated that the focal adhesion pathway was closely related with SPP1 in ESCA. Further studies confirmed that the knockdown of SPP1 suppressed cell adhesion ability and reduced the expression of p-FAK and p-Erk in ESCA cells. In addition, Y15 inhibited FAK autophosphorylation and dramatically inhibited cell proliferation, migration, and invasion in ESCA cells. SPP1 promotes tumor progression in ESCA by activating FAK/Erk pathway, and FAK is a potential therapeutic target to overcome tumor recurrence and metastasis of ESCA.

Injectable hybrid hydrogels enable enhanced combination chemotherapy and roused anti-tumor immunity in the synergistic treatment of pancreatic ductal adenocarcinoma

Chemotherapy and immunotherapy have shown no significant outcome for unresectable pancreatic ductal adenocarcinoma (PDAC). Multi-drug combination therapy has become a consensus in clinical trials to explore how to arouse anti-tumor immunity and meanwhile overcome the poorly tumoricidal effect and the stroma barrier that greatly hinders drug penetration. To address this challenge, a comprehensive strategy is proposed to fully utilize both the ferroptotic vulnerability of PDAC to potently irritate anti-tumor immunity and the desmoplasia-associated focal adhesion kinase (FAK) to wholly improve the immunosuppressive microenvironment via sustained release of drugs in an injectable hydrogel for increasing drug penetration in tumor location and averting systematic toxicity. The injectable hydrogel ED-M@CS/MC is hybridized with micelles loaded with erastin that exclusively induces ferroptosis and a FAK inhibitor defactinib for inhibiting stroma formation, and achieves sustained release of the drugs for up to 12 days. With only a single intratumoral injection, the combination treatment with erastin and defactinib produces further anti-tumor performance both in xenograft and KrasG12D-engineered primary PDAC mice and synergistically promotes the infiltration of CD8+ cytotoxic T cells and the reduction of type II macrophages. The findings may provide a novel promising strategy for the clinical treatment of PDAC.

Phase 1b/2a of narmafotinib (AMP945) in combination with gemcitabine and nab-paclitaxel in first-line patients with advanced pancreatic cancer (ACCENT trial): Interim analysis.

e16337 Background: Narmafotinib (AMP945) is a highly potent and selective, orally bioavailable inhibitor of Focal Adhesion Kinase (FAK). FAK is a non-receptor tyrosine kinase over-expressed in pancreatic cancer, where it contributes to cell survival, proliferation, migration and chemoresistance and thus plays a key role in tumor growth, FAK also contributes to multiple mechanisms underlying fibrosis and immunosuppression in the tumor microenvironment. Narmafotinib has successfully completed a Phase 1 study in healthy volunteers where the drug was safe and well tolerated with pharmacokinetics consistent with once-a-day dosing. A Phase 1b/2a trial of narmafotinib, in combination with gemcitabine and Abraxane, in advanced pancreatic cancer patients – the ACCENT trial – is currently underway in Australia and South Korea. Methods: The ACCENT trial (NCT05355298) is a Phase 1b/2a, open label study of the pharmacokinetics, safety and tolerability, and efficacy of narmafotinibin combination with gemcitabine and Abraxane (nab-paclitaxel) standard of care as first-line therapy in patients with advanced pancreatic cancer. The trial is a single-arm open label study conducted in two stages. In Part A, patients were enrolled in a 3+3 design to determine the narmafotinib recommended Phase 2 dose (RP2D), with narmafotinibdose-escalation (100, 200 and 400 mg). Safety and tolerability were assessed according to incidence and severity of adverse events. Narmafotinibplasma PK samples were collected on Days -8, -7, 1, 3, 8, and 10 of Run-In/Cycle 1. Imaging was conducted every 2 months. Part B of the trial is a Simon’s two stage design, with the primary objectives of assessing safety, tolerability, and efficacy of the combination using RECIST v1.1. Results: Preliminary analysis across all doses (14 patients) showed narmafotinib to be generally safe and well-tolerated and showed promising signs of efficacy. All patients who completed their first 28-day cycle of treatment elected to stay on narmafotinib and 9/14 patients have remained on trial for 5 months or more. There have been 6 confirmed PRs (4 in 400 mg cohort; 2 in 200 mg cohort) as best response. A single DLT was reported: uncontrolled grade 3 nausea (400 mg cohort). Fatigue, grade 3 or below related to narmafotinib occurred in more than one participant. The PK for narmafotinib is dose-proportional across the dose range tested, and the chemotherapy regimen used in this study did not impact narmafotinib PK. Safety, tolerability and efficacy data continues to be collected and will be presented. Conclusions: Based on this promising Phase 1b data, 400 mg of narmafotinib has been selected for the RP2D and Part B of the trial is now underway and recruiting patients in Australia and South Korea. The trial will enrol up to 50 patients as part of the Phase 2 expansion cohort. Clinical trial information: NCT05355298 .

Effect of targeting FAK by ifebemtinib and immunogenic cell death of Kras G12C/G12D inhibition on the efficacy of PD1 blockade.

e15102 Background: Focal adhesion kinase (FAK) is one major component of focal adhesion complex and is important in regulating cancer cell survival. Previously, we found that a clinical-stage FAK inhibitor, ifebemtinib (aka IN10018) can overcome drug resistance of Kras G12C inhibitors by down regulating the FAK-YAP signaling. Combination of Kras G12Ci and FAKi has demonstrated encouraging efficacy in NSCLC. Here, we reported that targeting Kras G12D by selective Kras G12Di can also be enhanced by ifebemtinib. Further, Kras G12C inhibition plus PD1 blockade has demonstrated clinical benefits in PD-L1 high expression patient population, but ≈30% of patients experienced early disease progression; this might be attributed to loss-of-function of LKB1 and others. Immunogenic cell death (ICD) of Kras inhibition is enhanced by ifebemtinib, ICD reportedly enhances anti-PD1 activity. Thus, Kras inhibition and PD1 blockade plus ifebemtinib may be an ideal combination for patients with Kras G12D. Methods: Cell killing and apoptosis assays were performed to test the combination of Kras G12D inhibition and ifebemtinib. FACs analysis evaluated exposure levels vs. ICD biomarkers. The mice inoculated with CRC GP2D and PDAC PC-07-0013 were used for evaluating the combinational effects of Kras G12Di and ifebemtinib. The tumor bearing mice with Kras G12D mutant/LKB1 loss, NSCLC KPL, and CRC CT26 with knock-in Kras G12C were used for testing the effects of Kras inhibition, ifebemtinib, and PD1 blockade. Results: Ifebemtinib enhances the drug effects of Kras G12D inhibition in vitro and in vivo. The dual regimen of ifebemtinib and Kras inhibition outperformed either monotherapy with significant ICD induction in vitro (calreticulin/GRP94 exposure). The triple regimen of Kras inhibition, FAK inhibition and PD1 blockade exhibited stronger anti-cancer effects compared to the other related therapies, especially in a Kras G12D mutant, LKB1 loss animal model which is intrinsically resistant to PD1 blockade/Kras G12D inhibition. Conclusions: We discovered that targeting FAK by ifebemtinib enhances the anti-cancer effects of Kras G12D inhibition. It promotes ICD by targeting Kras G12D or G12C, further primes the dual regimen of Kras inhibition and ifebemtinib towards a response to anti PD1 therapy. The preclinical results warrant a further evaluation in the clinic.

Updated study results of novel FAK/ALK/ROS1 inhibitor APG-2449 in patients (pts) with non-small-cell lung cancer (NSCLC) resistant to second-generation ALK inhibitors.

3124 Background: ALK inhibitors increase FAK pathway gene expression in ALK+ NSCLC cell lines, with the highest induced expression in drug-tolerant persister cells. This suggests that FAK pathway activation is involved in ALK inhibitor-induced early adaptive tolerance in ALK+ NSCLC. Investigational APG-2449 is a novel, orally active FAK inhibitor and a third-generation (3G) ALK/ROS1 tyrosine kinase inhibitor (TKI) with potent activity in preclinical models. APG-2449 is well tolerated at the recommended phase 2 dose (RP2D) and showed preliminary efficacy in pts resistant to 2G ALK TKIs. Here, we provide further safety and efficacy results and demonstrate associations between this therapy and FAK signaling pathways. Methods: After the RP2D was determined as 1,200 mg daily (QD), pts with NSCLC were enrolled into 2 dose expansion cohorts. Cohort 1 included pts who were resistant to 2G ALK TKIs. Cohort 2 included those who were ALK or ROS1 TKI naïve. Results: As of December 9, 2023, 144 pts (median [range] age, 53 [21-78] years; 53.5% female) with NSCLC, mesothelioma, or ovarian cancer were treated with APG-2449 at doses of 150 to 1,500 mg. A total of 129 (89.6%) pts had treatment-related adverse events (TRAEs), the most frequent of which were elevated serum creatinine (49.3%), ALT (42.4%), and AST (36.1%); nausea (28.5%); vomiting (23.6%); diarrhea (22.9%); and decreased leukocyte count (22.2%). In all, 20 (13.9%) TRAEs were grade ≥ 3. Of pts with TKI-naïve NSCLC (n = 36) treated at the RP2D, the overall response (ORR) and disease control rates (DCR = CR + PR + SD) were 68.2% (15/22) and 90.1% (20/22) in ROS1 TKI-naïve pts; and 78.6% (11/14) and 100% (14/14) in ALK TKI-naïve pts. Median progression-free survival (mPFS) in ALK TKI-naïve pts was not reached. Of 22 pts with NSCLC resistant to 2G ALK inhibitors and without targetable bypass gene mutations (e.g., KRAS G12C, BRAF V600E), 9 had PRs (9/22; 40.9%) and the mPFS during APG-2449 treatment at RP2D was 11.86 months. Nine of 12 pts in the RP2D group achieved intracranial PR, resulting in an intracranial ORR of 75.0%. Before APG-2449 administration, 17 tumor tissue samples were collected from pts with NSCLC resistant to 2G ALK inhibitors (in the RP2D group), and IHC was used to assess protein levels of phosphorylated FAK (pFAK). The PFS of pts treated with APG-2449 correlated with pFAK levels in baseline tumor tissue, and pts with higher pFAK levels were more likely to benefit from APG-2449 treatment. Conclusions: APG-2449 demonstrated preliminary efficacy in pts with NSCLC whose disease was TKI naïve and resistant to 2G ALK inhibitors, especially in brain metastases. High pFAK expression levels in baseline tumor tissue correlated with improved APG-2449 treatment responses in pts with NSCLC resistant to 2G ALK inhibitors. Internal study identifier: APG2449XC101. Clinical trial information: NCT03917043 .

Epithelial-mesenchymal transition status is a remarkable biomarker for the combination treatment with avutometinib and defactinib in KRAS-mutated non-small cell lung cancer.

Recent therapeutic strategies for KRAS-mutated cancers that inhibit the MAPK pathway have attracted considerable attention. The RAF/MEK clamp avutometinib (VS-6766/CH5126766/RO5126766/CKI27) is promising for patients with KRAS-mutated cancers. Although avutometinib monotherapy has shown clinical activity in patients with KRAS-mutated cancers, effective combination strategies will be important to develop. Using a phosphorylation kinase array kit, we explored the feedback mechanism of avutometinib in KRAS-mutated NSCLC cells, and investigated the efficacy of combining avutometinib with inhibitors of the feedback signal using in vitro and in vivo experiments. Moreover, we searched for a biomarker for the efficacy of combination therapy through an in vitro study and analysis using the The Cancer Genome Atlas Programme dataset. Focal adhesion kinase (FAK) phosphorylation/activation was increased after avutometinib treatment and synergy between avutometinib and FAK inhibitor, defactinib, was observed in KRAS-mutated NSCLC cells with an epithelial rather than mesenchymal phenotype. Combination therapy with avutometinib and defactinib induced apoptosis with upregulation of Bim in cancer cells with an epithelial phenotype in an in vitro and in vivo study. These results demonstrate that the epithelial-mesenchymal transition status may be a promising biomarker for the efficacy of combination therapy with avutometinib and defactinib in KRAS-mutated NSCLC.

CircMTO1/miR-30c-5p/SOCS3 axis alleviates oral submucous fibrosis through inhibiting fibroblast-myofibroblast transition.

circRNAs have been shown to participate in diverse diseases; however, their role in oral submucous fibrosis (OSF), a potentially malignant disorder, remains obscure. Our preliminary experiments detected the expression of circRNA mitochondrial translation optimization 1 homologue (circMTO1) in OSF tissues (n = 20) and normal mucosa tissues (n = 20) collected from Hunan Xiangya Stomatological Hospital, and a significant decrease of circMTO1 expression was showed in OSF tissues. Therefore, we further explored circMTO1 expression in OSF. Target molecule expression was detected using RT-qPCR and western blotting. The migration and invasion of buccal mucosal fibroblasts (BMFs) were assessed using wound healing and Transwell assays. The interaction between miR-30c-5p, circMTO1, and SOCS3 was evaluated using dual luciferase, RNA immunoprecipitation (RIP), and RNA pull-down assays. The colocalisation of circMTO1 and miR-30c-5p was observed using fluorescence in situ hybridisation (FISH). circMTO1 and SOCS3 expression decreased, whereas miR-30c-5p expression increased in patients with OSF and arecoline-stimulated BMFs. Overexpression of circMTO1 effectively restrained the fibroblast-myofibroblast transition (FMT), as evidenced by the increase in expression of Coll I, α-SMA, Vimentin, and the weakened migration and invasion functions in BMFs. Mechanistic studies have shown that circMTO1 suppresses FMT by enhancing SOCS3 expression by sponging miR-30c-5p and subsequently inactivating the FAK/PI3K/AKT pathway. FMT induced by SOCS3 silencing was reversed by the FAK inhibitor TAE226 or the PI3K inhibitor LY294002. circMTO1/miR-30c-5p/SOCS3 axis regulates FMT in arecoline-treated BMFs via the FAK/PI3K/AKT pathway. Expanding the sample size and in vivo validation could further elucidate their potential as therapeutic targets for OSF.

IGFBP2 induces podocyte apoptosis promoted by mitochondrial damage via integrin α5/FAK in diabetic kidney disease.

Podocyte apoptosis or loss is the pivotal pathological characteristic of diabetic kidney disease (DKD). Insulin-like growth factor-binding protein 2 (IGFBP2) have a proinflammatory and proapoptotic effect on diseases. Previous studies have shown that serum IGFBP2 level significantly increased in DKD patients, but the precise mechanisms remain unclear. Here, we found that IGFBP2 levels obviously increased under a diabetic state and high glucose stimuli. Deficiency of IGFBP2 attenuated the urine protein, renal pathological injury and glomeruli hypertrophy of DKD mice induced by STZ, and knockdown or deletion of IGFBP2 alleviated podocytes apoptosis induced by high concentration of glucose or in DKD mouse. Furthermore, IGFBP2 facilitated apoptosis, which was characterized by increase in inflammation and oxidative stress, by binding with integrin α5 (ITGA5) of podocytes, and then activating the phosphorylation of focal adhesion kinase (FAK)-mediated mitochondrial injury, including membrane potential decreasing, ROS production increasing. Moreover, ITGA5 knockdown or FAK inhibition attenuated the podocyte apoptosis caused by high glucose or IGFBP2 overexpression. Taken together, these findings unveiled the insight mechanism that IGFBP2 increased podocyte apoptosis by mitochondrial injury via ITGA5/FAK phosphorylation pathway in DKD progression, and provided the potential therapeutic strategies for diabetic kidney disease.

Platelet Spreading and Clot Retraction are Regulated by two Distinct αIIbβ3 Outside-in Signaling Pathways.

Bi-directional signaling through platelet integrin αIIbβ3 is essential in hemostasis and thrombosis. In quiescent platelets αIIbβ3 is in a low-affinity ligand binding state. However, upon platelet activation by agonists through inside-out signaling, a rapid switch in the conformation of the integrin results in a high affinity ligand binding state capable of binding soluble fibrinogen. Ligand binding to the αIIbβ3 induces a signaling termed outside-in signaling that regulate platelet spreading and clot retraction. These events are often interchangeably used to represent outside-in signaling pathway. Using pharmacological inhibitors of known signaling molecules that have been implicated to regulate outside-in signaling, we assessed human platelet spreading and clot retraction. We found that inhibition of PI3K, PLC, PKC, and FAK strongly attenuated both platelet spreading and clot retraction suggesting that they are essential for both clot retraction and platelet spreading. Whereas inhibition of Rac1, ROCK, p38, and MEK did not affect platelet spreading but significantly delayed clot retraction suggesting that these signaling molecules do not participate in platelet spreading. Interestingly, Src family kinases (SFKs) are required for platelet spreading and FAK activation but suppresses clot retraction since their inhibition causes faster clot retraction. Thus, it becomes evident that platelet spreading, and clot retraction are differently regulated through αIIbβ3 outside-in signaling and should not be used interchangeably as readout for αIIbβ3 outside-in signaling assessment. Significance Statement Current anti-platelet drugs have increased risk of bleeding and low efficacy. There is an increased effort to identify novel anti-platelet agents that have improved efficacy with reduced risk of bleeding. It is increasingly felt that inhibition of αIIbβ3-induced outside-in signaling may inhibit thrombosis without compromising hemostasis. However, the signaling entities regulating outside-in signaling is poorly understood. Our work included in this manuscript delineates the distinct signaling pathways involved in outside-in signaling and identify potential novel targets for intervention of thrombosis.

FBXO32 Stimulates Protein Synthesis to Drive Pancreatic Cancer Progression and Metastasis.

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer-related death worldwide, primarily due to its rapid progression. The current treatment options for PDAC are limited, and a better understanding of the underlying mechanisms responsible for PDAC progression is required to identify improved therapeutic strategies. Here, we identified FBXO32 as an oncogenic driver in PDAC. FBXO32 was aberrantly upregulated in PDAC, and high FBXO32 expression was significantly associated with an unfavorable prognosis in PDAC patients. FRG1 deficiency promoted FBXO32 upregulation in PDAC. FBXO32 promoted cell migration and invasion in vitro and tumor growth and metastasis in vivo. Mechanistically, FBXO32 directly interacted with eEF1A1 and promoted its polyubiquitination at the K273 site, leading to enhanced activity of eEF1A1 and increased protein synthesis in PDAC cells. Moreover, FBXO32-catalyzed eEF1A1 ubiquitination boosted the translation of ITGB5 mRNA and activated FAK signaling, thereby facilitating focal adhesion assembly and driving PDAC progression. Importantly, interfering with the FBXO32-eEF1A1 axis or pharmaceutical inhibition of FAK by defactinib, an FDA-approved FAK inhibitor, substantially inhibited PDAC growth and metastasis driven by aberrantly activated FBXO32-eEF1A1 signaling. Overall, this study uncovers a mechanism by which PDAC cells rely on FBXO32-mediated eEF1A1 activation to drive progression and metastasis. FBXO32 may serve as a promising biomarker for selecting eligible PDAC patients for treatment with defactinib.

Computational insights into allosteric inhibition of focal adhesion kinase: A combined pharmacophore modeling and molecular dynamics approach

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that modulates integrin and growth factor signaling pathways and is implicated in cancer cell migration, proliferation, and survival. Over the past decade various, FAK kinase, FERM, and FAT domain inhibitors have been reported and a few kinase domain inhibitors are under clinical consideration. However, few of them were identified as multikinase inhibitors. In kinase drug design selectivity is always a point of concern, to improve selectivity allosteric inhibitor development is the best choice. The current research utilized a pharmacophore modeling (PM) approach to identify novel allosteric inhibitors of FAK. The all-available allosteric inhibitor bound 3D structures with PDB ids 4EBV, 4EBW, and 4I4F were utilized for the pharmacophore modeling. The validated PM models were utilized to map a database of 770,550 compounds prepared from ZINC, EXIMED, SPECS, ASINEX, and InterBioScreen, aiming to identify potential allosteric inhibitors. The obtained compounds from screening step were forwarded to molecular docking (MD) for the prediction of binding orientation inside the allosteric site and the results were evaluated with the known FAK allosteric inhibitor (REF). Finally, 14 FAK-inhibitor complexes were selected from the docking study and were studied under molecular dynamics simulations (MDS) for 500 ns. The complexes were ranked according to binding free energy (BFE) and those demonstrated higher affinity for allosteric site of FAK than REF inhibitors were selected. The selected complexes were further analyzed for intermolecular interactions and finally, three potential allosteric inhibitor candidates for the inhibition of FAK protein were identified. We believe that identified scaffolds may help in drug development against FAK as an anticancer agent.

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

Insufficient functional β-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 β-like cells. The acinar-derived insulin-producing cells infiltrate the pre-existing endocrine islets, partially restore β-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.

KRAS G12C inhibitor combination therapies: current evidence and challenge.

Although KRAS G12C inhibitors have proven that KRAS is a "druggable" target of cancer, KRAS G12C inhibitor monotherapies have demonstrated limited clinical efficacy due to primary and acquired resistance mechanisms. Multiple combinations of KRAS G12C inhibitors with other targeted therapies, such as RTK, SHP2, and MEK inhibitors, have been investigated in clinical trials to overcome the resistance. They have demonstrated promising efficacy especially by combining KRAS G12C and EGFR inhibitors for KRAS G12C-mutated colorectal cancer. Many clinical trials of combinations of KRAS G12C inhibitors with other targeted therapies, such as SOS1, ERK, CDK4/6, and wild-type RAS, are ongoing. Furthermore, preclinical data have suggested additional promising KRAS G12C combinations with YAP/TAZ-TEAD inhibitors, FAK inhibitors, and farnesyltransferase inhibitors. The combinations of KRAS G12C inhibitors with immunotherapies and chemotherapies have also been investigated, and the preliminary results were reported. More recently, KRAS-targeted therapies not limited to KRAS G12C are being developed, potentially broadening the treatment landscape of KRAS-mutated cancers. Rationally combining KRAS inhibitors with other therapeutics is likely to play a significant role in future treatment for KRAS-mutated solid tumors.

Focal adhesion kinase (FAK) inhibition induces aquaporin 2 (AQP2) plasma membrane accumulation in renal epithelial cells by remodeling the actin cytoskeleton

The actin cytoskeleton is involved in the cellular traffcking of the AQP2 water channel in kidney collecting duct (CD) principal cells (PC): this plays an important role in water homeostasis. Focal adhesion kinase (FAK) is known to modulate the actin cytoskeleton through small GTPase-mediated pathways and we, therefore, investigated the potential role of FAK in AQP2 traffcking. We and others have previously shown that AQP2 constitutively traffcs and recycles independently of vasopressin (VP) and that this involves actin depolymerization/polymerization; therefore, FAK could regulate AQP2 traffcking through actin remodeling, bypassing the VP-V2R (cAMP/PKA) signaling pathway. To examine this, we used small molecule FAK inhibitors, VS-4718, GSK2256098 (GSK), or Defactinib-Hydrochloride (DH). We used immunofluorescence staining, a transferrin endocytosis assay ± cold block treatment, a fluorometric exocytosis assay using cells expressing secreted yellow fluorescent protein (ssYFP), a RhoA activity assay, and western blotting. Inhibiting FAK with 1mM VS-4718 for 30 min increased AQP2 membrane accumulation in LLCPK1 and IMCD kidney epithelial cells expressing AQP2. VS-4718 resulted in reduced clathrin-mediated endocytosis, as well as increased vesicle exocytosis, both mechanisms contributing to increased AQP2 membrane accumulation. This effect of FAK inhibition was independent of vasopressin/cAMP signaling and did not require phosphorylation of the Serine 256 residue of AQP2, since AQP2 membrane accumulation also occurred in cells expressing the constitutive dephosphorylation AQP2 S256A mutant. The FAK inhibitor VS-4718 promoted actin depolymerization (phalloidin staining assay) which would facilitate AQP2 vesicle exocytosis into the plasma membrane. We then examined the activity of the small GTPase, RhoA, whose activity increases actin polymerization and vesicle traffcking in the exocytic and endocytic pathways. We found that FAK inhibition by VS-4718 downregulated RhoA activity using GST-RBD, a substrate that binds to active RhoA, as seen by western blotting using phospho-specific antibodies. Similar results were obtained with GSK and DH. In summary, our study revealed that the interaction between FAK and cytoskeletal architecture plays a crucial role in regulating AQP2 recycling and its subsequent entry into the endocytic pathway. Thus, targeting FAK could be a potential therapeutic strategy for water balance disorders involving defective AQP2 reabsorption, such as nephrogenic diabetes insipidus. This work was supported by NIDDK R01DK096015 (JHL) and DK096586 (DB). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Cyclic strain alters the transcriptional and migratory response of scleral fibroblasts to TGFβ

In glaucoma, scleral fibroblasts are exposed to IOP-associated mechanical strain and elevated TGFβ levels. These stimuli, in turn, lead to scleral remodeling. Here, we examine the scleral fibroblast migratory and transcriptional response to these stimuli to better understand mechanisms of glaucomatous scleral remodeling. Human peripapillary scleral (PPS) fibroblasts were cultured on parallel grooves, treated with TGFβ (2 ng/ml) in the presence of vehicle or TGFβ signaling inhibitors, and exposed to uniaxial strain (1 Hz, 5%, 12–24 h). Axis of cellular orientation was determined at baseline, immediately following strain, and 24 h after strain cessation with 0° being completely aligned with grooves and 90° being perpendicular. Fibroblasts migration in-line and across grooves was assessed using a scratch assay. Transcriptional profiling of TGFβ-treated fibroblasts with or without strain was performed by RT-qPCR and pERK, pSMAD2, and pSMAD3 levels were measured by immunoblot. Pre-strain alignment of TGFβ-treated cells with grooves (6.2 ± 1.5°) was reduced after strain (21.7 ± 5.3°, p < 0.0001) and restored 24 h after strain cessation (9.5 ± 2.6°). ERK, FAK, and ALK5 inhibition prevented this reduction; however, ROCK, YAP, or SMAD3 inhibition did not. TGFβ-induced myofibroblast markers were reduced by strain (αSMA, POSTN, ASPN, MLCK1). While TGFβ-induced phosphorylation of ERK and SMAD2 was unaffected by cyclic strain, SMAD3 phosphorylation was reduced (p = 0.0004). Wound healing across grooves was enhanced by ROCK and SMAD3 inhibition but not ERK or ALK5 inhibition. These results provide insight into the mechanisms by which mechanical strain alters the cellular response to TGFβ and the potential signaling pathways that underlie scleral remodeling.

MiRSNP rs188493331: A key player in genetic control of microRNA-induced pathway activation in hypertrophic scars and keloids.

Our study aims to delineate the miRSNP-microRNA-gene-pathway interactions in the context of hypertrophic scars (HS) and keloids. We performed a computational biology study involving differential expression analysis to identify genes and their mRNAs in HS and keloid tissues compared to normal skin, identifying key hub genes and enriching their functional roles, comprehensively analyzing microRNA-target genes and related signaling pathways through bioinformatics, identifying MiRSNPs, and constructing a pathway-based network to illustrate miRSNP-miRNA-gene-signaling pathway interactions. Our results revealed a total of 429 hub genes, with a strong enrichment in signaling pathways related to proteoglycans in cancer, focal adhesion, TGF-β, PI3K/Akt, and EGFR tyrosine kinase inhibitor resistance. Particularly noteworthy was the substantial crosstalk between the focal adhesion and PI3K/Akt signaling pathways, making them more susceptible to regulation by microRNAs. We also identified specific miRNAs, including miRNA-1279, miRNA-429, and miRNA-302e, which harbored multiple SNP loci, with miRSNPs rs188493331 and rs78979933 exerting control over a significant number of miRNA target genes. Furthermore, we observed that miRSNP rs188493331 shared a location with microRNA302e, microRNA202a-3p, and microRNA20b-5p, and these three microRNAs collectively targeted the gene LAMA3, which is integral to the focal adhesion signaling pathway. The study successfully unveils the complex interactions between miRSNPs, miRNAs, genes, and signaling pathways, shedding light on the genetic factors contributing to HS and keloid formation.

Direct contact between tumor cells and platelets initiates a FAK-dependent F3/TGF-β positive feedback loop that promotes tumor progression and EMT in osteosarcoma

Platelets have received growing attention for their roles in hematogenous tumor metastasis. However, the tumor-platelet interaction in osteosarcoma (OS) remains poorly understood. Here, using platelet-specific focal adhesion kinase (FAK)-deficient mice, we uncover a FAK-dependent F3/TGF-β positive feedback loop in OS. Disruption of the feedback loop by inhibition of F3, TGF-β, or FAK significantly suppresses OS progression. We demonstrate that OS F3 initiated the feedback loop by increasing platelet TGF-β secretion, and platelet-derived TGF-β promoted OS F3 expression in turn and modulated OS EMT process. Immunofluorescence results indicate platelet infiltration in OS niche and we verified it was mediated by platelet FAK. In addition, platelet FAK was proved to mediate platelet adhesion to OS cells, which was vital for the initiation of F3/TGF-β feedback loop. Collectively, these findings provide a rationale for novel therapeutic strategies targeting tumor-platelet interplay in metastatic OS.

Recurrent RhoGAP gene fusion CLDN18-ARHGAP26 promotes RHOA activation and focal adhesion kinase and YAP-TEAD signalling in diffuse gastric cancer

ObjectiveGenomic studies of gastric cancer have identified highly recurrent genomic alterations impacting RHO signalling, especially in the diffuse gastric cancer (DGC) histological subtype. Among these alterations are interchromosomal translations leading...