Focal Adhesion Kinase Activation Research Articles

Fibrillar extracellular matrix produced by pericyte-like cells facilitates glioma cell dissemination.

Gliomagenesis induces profound changes in the composition of the extracellular matrix (ECM) of the brain. In this study, we identified a cellular population responsible for the increased deposition of collagen I and fibronectin in glioblastoma. Elevated levels of the fibrillar proteins collagen I and fibronectin were associated with the expression of fibroblast activation protein (FAP), which is predominantly found in pericyte-like cells in glioblastoma. FAP+ pericyte-like cells were present in regions rich in collagen I and fibronectin in biopsy material and produced substantially more collagen I and fibronectin in vitro compared to other cell types found in the GBM microenvironment. Using mass spectrometry, we demonstrated that 3D matrices produced by FAP+ pericyte-like cells are rich in collagen I and fibronectin and contain several basement membrane proteins. This expression pattern differed markedly from glioma cells. Finally, we have shown that ECM produced by FAP+ pericyte-like cells enhances the migration of glioma cells including glioma stem-like cells, promotes their adhesion, and activates focal adhesion kinase (FAK) signaling. Taken together, our findings establish FAP+ pericyte-like cells as crucial producers of a complex ECM rich in collagen I and fibronectin, facilitating the dissemination of glioma cells through FAK activation.

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.

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...

FAK-LINC01089 negative regulatory loop controls chemoresistance and progression of small cell lung cancer.

The focal adhesion kinase (FAK) tyrosine kinase is activated and upregulated in multiple cancer types including small cell lung cancer (SCLC). However, FAK inhibitors have shown limited efficacy in clinical trials for cancer treatment. With the aim of identifying potential therapeutic strategies to inhibit FAK for cancer treatment, we investigated long non-coding RNAs (lncRNAs) that potentially regulate FAK in SCLC. In this study, we identified a long non-coding RNA LINC01089 that binds and inhibits FAK phosphorylation (activation). Expression analysis revealed that LINC01089 was downregulated in SCLC tissues and negatively correlated with chemoresistance and survival in SCLC patients. Functionally, LINC01089 inhibited chemoresistance and progression of SCLC in vitro and in vivo. Mechanistically, LINC01089 inhibits FAK activation by blocking binding with Src and talin kinases, while FAK negatively regulates LINC01089 transcription by activating the ERK signaling pathway to recruit the REST transcription factor. Furthermore, LINC01089-FAK axis mediates the expression of drug resist-related genes by modulating YBX1 phosphorylation, leading to drug resistance in SCLC. Intriguingly, the FAK-LINC01089 interaction depends on the co-occurrence of the novel FAK variant and the non-conserved region of LINC01089 in primates. In Conclusion, our results indicated that LINC01089 may serve as a novel high-efficiency FAK inhibitor and the FAK-LINC01089 axis represents a valuable prognostic biomarker and potential therapeutic target in SCLC.

Repurposing the diuretic benzamil as an anti-osteosarcoma agent that acts by suppressing integrin/FAK/STAT3 signalling and compromising mitochondrial function.

Osteosarcoma is the most common primary bone malignancy among children and adolescents. We investigated whether benzamil, an amiloride analogue and sodium-calcium exchange blocker, may exhibit therapeutic potential for osteosarcoma in vitro. MG63 and U2OS cells were treated with benzamil for 24 hours. Cell viability was evaluated with the MTS/PMS assay, colony formation assay, and flow cytometry (forward/side scatter). Chromosome condensation, the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay, cleavage of poly-ADP ribose polymerase (PARP) and caspase-7, and FITC annexin V/PI double staining were monitored as indicators of apoptosis. Intracellular calcium was detected by flow cytometry with Fluo-4 AM. The phosphorylation and activation of focal adhesion kinase (FAK) and signal transducer and activator of transcription 3 (STAT3) were measured by western blot. The expression levels of X-linked inhibitor of apoptosis protein (XIAP), B-cell lymphoma 2 (Bcl-2), B-cell lymphoma-extra large (Bcl-xL), SOD1, and SOD2 were also assessed by western blot. Mitochondrial status was assessed with tetramethylrhodamine, ethyl ester (TMRE), and intracellular adenosine triphosphate (ATP) was measured with BioTracker ATP-Red Live Cell Dye. Total cellular integrin levels were evaluated by western blot, and the expression of cell surface integrins was assessed using fluorescent-labelled antibodies and flow cytometry. Benzamil suppressed growth of osteosarcoma cells by inducing apoptosis. Benzamil reduced the expression of cell surface integrins α5, αV, and β1 in MG63 cells, while it only reduced the expression of αV in U2OS cells. Benzamil suppressed the phosphorylation and activation of FAK and STAT3. In addition, mitochondrial function and ATP production were compromised by benzamil. The levels of anti-apoptotic proteins XIAP, Bcl-2, and Bcl-xL were reduced by benzamil. Correspondingly, benzamil potentiated cisplatin- and methotrexate-induced apoptosis in osteosarcoma cells. Benzamil exerts anti-osteosarcoma activity by inducing apoptosis. In terms of mechanism, benzamil appears to inhibit integrin/FAK/STAT3 signalling, which triggers mitochondrial dysfunction and ATP depletion.

The suppression of cell motility through the reduction of FAK activity and expression of cell adhesion proteins by hAMSCs secretome in MDA-MB-231 breast cancer cells.

Breast cancer is a leading cause of death in women worldwide. Cancer therapy based on stem cells is considered as a novel and promising platform. In the present study, we explore the therapeutic effects of human amniotic mesenchymal stromal cells (hAMSCs) through the reduction of focal adhesion kinase (FAK) activity, SHP-2, and cell adhesion proteins such as Paxillin, Vinculin, Fibronectin, Talin, and integrin αvβ3 expression in MDA-MB-231 breast cancer cells. For this purpose, we employed a co-culture system using 6-well plate transwell. After 72h, hAMSCs-treated MDA-MB-231 breast cancer cells, the activity of focal adhesion kinase (FAK) and the expression of SHP-2 and cell adhesion proteins such as Paxillin, Vinculin, Fibronectin, Talin, and integrin αvβ3 expression were analyzed using western blot. The shape and migration of cells were also analyzed. Based on our results, a significant reduction in tumor cell motility through downregulation of the tyrosine phosphorylation level of FAK (at Y397 and Y576/577 sites) and cell adhesion expression in MDA-MB-231 breast cancer cells was demonstrated. Our findings indicate that hAMSCS secretome has therapeutic effects on cancer cell migration through downregulation of FAK activity and expression of cell adhesion proteins.

Abstract 310: Cadherin-dependent modulation of chemosensitivity in oral tumor progression

Abstract The progression of healthy oral epithelia to an oral carcinoma often involves aberrant expression of a group of calcium-dependent transmembrane proteins called cadherins. Histological studies of human tumors have demonstrated increased expression of the epithelial-resident placental (P-cadherin) and ectopic expression of the mesenchymal neuronal (N-cadherin) cadherin in oral dysplasia. We hypothesized that these changes in cadherin expression during early oral tumor development could facilitate increases in survival signaling. We genetically modified dysplastic oral keratinocytes to overexpress P-cadherin or suppress endogenous expression of N-cadherin. P-cadherin overexpression and N-cadherin suppression independently elicited a 3-6-fold decrease in apoptosis levels in response to docetaxel treatment compared to similarly treated controls. We found that in untreated dysplastic cells, P- and N-cadherin expression had positive and negative correlations, respectively, with the activation of the survival-associated enzymes focal adhesion kinase (FAK), mitogen-activated protein kinase (MAPK), and AKT kinase. The total levels of nuclear factor kappa B (NFkb) were positively correlated with P-cadherin overexpression and reciprocally correlated with levels of N-cadherin. In docetaxel-treated dysplastic cells, we observed the reverse effect compared to untreated cells: the increased level of N-cadherin was positively correlated with FAK activity whereas FAK activity was suppressed by P-cadherin. P-cadherin expression in docetaxel-treated cells also increased activation of both MAPK and AKT, whereas alteration of N-cadherin levels had no effect. Because N-cadherin levels are known to increase in late-stage oral tumors, we extended these signaling studies to oral squamous carcinoma cells (OSCCs) expressing low or high levels of N-cadherin. In contrast to its suppression of survival pathways in docetaxel-treated dysplastic cells, in docetaxel-treated OSCCs, N-cadherin expression strongly enhanced phosphorylation of MAPK and AKT, and increased expression of NFkb. N-cadherin overexpression during this treatment also increased expression of the antiapoptotic proteins Mcl-1 and suppressed phosphorylation of the apoptotic regulator signal transducer and activator of transcription 3 (pSTAT3). Increase cadherin expression in all untreated cell lines increased expression of an inducer of epithelial to mesenchymal transition, the transmembrane protein mucin-1 (MUC1). N-cadherin overexpression also increased motility in both cell lines. Taken together, our data demonstrate antiapoptotic signaling directed by increased levels of P-cadherin in oral dysplasia and N-cadherin in OSCC, whereas increased levels of N-cadherin in dysplastic cells directed cellular signaling that were associated with a proapoptotic phenotype. Citation Format: Aaron Mody, Cassandra Decker, Kathryn R. Lawson. Cadherin-dependent modulation of chemosensitivity in oral tumor progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 310.

Abstract 1935: The FAK/SRC axis mediates resistance to KRAS G12C inhibitors and its blockade can overcome KRAS inhibitor resistance

Abstract Activating mutations in KRAS are found in approximately 30% of non-small cell lung cancer (NSCLC), and among all KRAS mutations, KRAS G12C is the most frequent variant in NSCLC, with a prevalence of approximately 14%. KRAS G12C inhibitors, sotorasib and adagrasib are FDA approved for locally advanced or metastatic KRAS G12C-positive NSCLC. However, clinical evidence suggests that there are various factors limiting the efficacy of KRAS G12C inhibitors in patients with KRAS G12C-positive NSCLC, highlighting the urgent need for novel treatment strategies or combinations to improve efficacy. Therefore, we sought to identify effective combinations to enhance the efficacy of KRAS G12C inhibitors using in vitro and in vivo models of KRAS G12C-positive NSCLC. Employing a high throughput in vitro drug screening effort using KRAS mutant NSCLC cell lines, we observed that Focal Adhesion Kinase (FAK) and Steroid Receptor Coactivator (SRC) inhibitors produced a synergistic effect when combined with KRAS G12C inhibitors adagrasib or sotorasib. As determined by reverse phase array and Western blotting, in H358, H23, HCC44, and H2122 cells, KRAS inhibitor treatment alone resulted in an initial suppression of RAS/MAPK and AKT pathway activation which was followed by upregulation of multiple receptor tyrosine kinases and integrins which contributed to the re-activation of the RAS/MAPK and AKT pathways after 24-48 hours. We identified FAK as a key downstream mediator of these bypass pathways. FAK/SRC inhibitors enhanced the efficacy of KRAS G12C inhibitors by preventing this feedback activation. Moreover, we observed increased FAK activation in H358 NSCLC cell lines with acquired resistance to adagrasib or sotorasib as compared to parental cells, and FAK/SRC inhibitors re-sensitized resistant cells to KRAS G12C inhibitors. Using a xenograft model of human KRAS mutant NSCLC, we determined that the combination of repotrectinib, a FAK/SRC inhibitor, and a KRAS G12C inhibitor significantly suppressed tumor growth as compared to KRAS G12C inhibitors alone, and this combination was well tolerated. Overall, our findings indicate that activation of FAK is a key mechanism of adaptive feedback and acquired resistance to KRAS G12C inhibitors in KRAS G12C-positive NSCLC and highlight the therapeutic potential of FAK/SRC inhibitors in combination with KRAS G12C inhibitors. These data support the clinical testing of the combination of FAK/SRC inhibitors and KRAS G12C inhibitors in patients with KRAS G12C-positive NSCLC. Citation Format: Yuji Shibata, Hibiki Udagawa, Monique B. Nilsson, Jacqulyne Robichaux, Ana Galan-Cobo, Marcelo Negrao, David P. Molkentine, Junqin He, Alissa Poteete, Yu Qian, Qian Huang, Ferdinandos Skoulidis, John V. Heymach. The FAK/SRC axis mediates resistance to KRAS G12C inhibitors and its blockade can overcome KRAS inhibitor resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1935.

Abstract 4745: A novel combination therapy targeting RAF, MEK and FAK to overcome skin cutaneous melanoma treatment resistance

Abstract Metastatic melanoma is the most aggressive malignancy of the skin and BRAFV600E mutation is the most common genetic alteration in skin cutaneous melanoma (SKCM). Despite the advent of immune checkpoint inhibition (ICI) immunotherapy, only 40% of patients show long-term responses. As such, combined therapy with BRAF and MEK inhibitors (BRAFi + MEKi) remains the standard of care for BRAFV600E+ SKCM. In the present study, transcriptome analysis of BRAFV600E+ SKCM tumors derived from patients revealed that activation of extracellular matrix signaling, including focal adhesion signaling, is highly enriched in patients who experienced disease progression on BRAFi + MEKi therapy. Consistent with these results, we found increased activation of focal adhesion kinase (FAK) in human BRAFV600E+ SKCM A375 cells treated with BRAFi, MEKi or the RAF/MEK clamp avutometinib. Mechanistically, we discovered that avutometinib-mediated inhibition of the RAF/MEK/ERK pathway decreased RhoE/Rnd3 expression, thereby unleashing RhoA/FAK/AKT signaling. Thus, we hypothesized that FAK activation represents a resistance mechanism to BRAFi + MEKi and that FAK inhibition (FAKi) might overcome resistance to BRAFi/MEKi. Indeed, avutometinib demonstrated synergistic antiproliferative and proapoptotic activity when combined with FAKi in human BRAFV600E+ SKCM A375 cells. Importantly, we found that the combination of FAKi + avutometinib overcame resistance to BRAFi + MEKi in SKCM xenografts and patient-derived cells from SKCM-resistant lesions. Finally, we showed that while BRAFV600E+ SKCM YUMM 1.7 syngeneic tumors failed to respond to ICI therapy, avutometinib ± FAKi inhibited tumor growth. We observed that tumors treated with avutometinib as single agent eventually developed resistance and escaped growth inhibition, but those treated with combined avutometinib and FAKi displayed durable treatment responses, often with complete tumor regression. These findings provide a rationale for the clinical development of avutometinib with defactinib (FAKi) in patients with BRAFV600E+ cutaneous melanoma following progression on BRAFi + MEKi and/or ICI therapy. Citation Format: Simone Lubrano, Farhoud Faraji, Rodolfo Daniel Cervantes-Villagrana, Sydney Ramirez, Nadia Arang, Adam Officer, Damiano C. Rigiracciolo, Paola Y. Anguiano Quiroz, Antonieta Bacchiocchi, Ruth Halaban, Silvia Coma, Sheri Holmen, Claudia Martini, Jonathan Pachter, Andrew Aplin, J. Silvio Gutkind. A novel combination therapy targeting RAF, MEK and FAK to overcome skin cutaneous melanoma treatment resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4745.

Abstract 954: An evaluation of the combination of metformin and Y15 for the treatment of platinum-resistant ovarian cancer

Abstract Ovarian cancer is the fifth leading cause of cancer mortality among women. This high mortality rate is linked to the development of resistance to first-line chemotherapy with platinum compounds which has been attributed in part to increased activity of focal adhesion kinase (FAK). The anti-diabetic drug Metformin was previously shown to inhibit the proliferation and migration of ovarian cancer cells and thus, the combination of a FAK inhibitor, Y15, and Metformin may be a promising treatment for platinum-resistant ovarian cancer (PROC). The objective of this study was to evaluate the combination of Y15 and Metformin on PROC cell viability and the mechanism of cell death. An MTT assay was used to analyze cell viability in PROC OVCAR3 cells after 48 h of treatment by measuring the absorbance at 570 nm with a microplate reader. Western blot was used to determine the protein levels of the apoptosis marker cleaved PARP and the autophagy marker LC3B-II. The exposure of OVCAR3 platinum-resistant ovarian cancer cells to Metformin (4.5 mM) + Y15 (5.5 µM) resulted in a significantly enhanced cytotoxicity (32.6 ± 1.8%) compared to single drug treatment with either Metformin (4.5 mM) (65.0 ± 4.2%) or Y15 (5.5 µM) (66.0 ± 4.8%). A combination of Metformin (7.8 mM) + Y15 (5.5 µM) also resulted in a significantly enhanced cytotoxicity (22.8 ± 1.5%) compared to single drug treatment with either Metformin (7.8 mM) (50.7 ± 3.7%) or Y15 (5.5 µM) (66.0 ± 4.8%). Cells treated with the combination of Metformin and Y15 for 24, 48, and 72-hours showed an increase in cleaved PARP compared to the control, Metformin alone and Y15 alone. For Metformin alone, there was an increase in cleaved PARP compared to the control at all timepoints and increased from 24 hours to 72 hours. For Y15 alone, the amount of cleaved PARP was also higher compared to the control at all time points, however, decreased over time from 24 hours to 72 hours. Cells treated with Metformin, Y15, and a combination of Metformin and Y15 showed no conversion of LC3B-I to LC3B-II, which occurs during autophagy. Thus, it is concluded that the mechanism of cell death for both Metformin and Y15 is through apoptosis and not autophagy and apoptosis is enhanced with the combination of the drugs. The delivery of Metformin and Y15 can result in an additive effect on cell viability through apoptosis and can be further explored as a promising approach for the treatment of PROC. Citation Format: Manuel A. Duarte, Kristal Garcia, Marco A. Arriaga, Sue Anne Chew, Arkene S. Levy, Isabela Mendez. An evaluation of the combination of metformin and Y15 for the treatment of platinum-resistant ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 954.

Abstract 1928: Targeting FAK to improve the therapy of KRAS G12C mutant cancers

Abstract Despite the pivotal role of KRAS G12C in tumor initiation and progression, currently available KRAS G12C inhibitors have relatively modest activity compared to other approved therapies targeting other classic oncogenic drivers. Fortunately, efforts to improve the anti-tumor response to KRAS G12C targeted therapy have benefited from the use of combination approaches. Here, we found that treatment with KRAS G12C inhibitors induces sustained activation of focal adhesion kinase (FAK) in KRAS G12C mutant cell lines from various cancer types, including non-small cell lung cancer, colorectal cancer, and pancreatic cancer. These results suggest a potential role for FAK in adaptive resistance to KRAS G12C inhibition and encourage us to explore the anticancer effects of combining the KRAS G12C inhibitor SY-5933 with a FAK inhibitor, CT-707. The cell viability and clonogenic assays using various KRAS G12C mutant cancer cell lines showed that the combination of SY-5933 and CT-707 synergistically inhibited cell growth. Mechanistically, this enhanced anti-proliferative effect is associated with a significant decrease in FAK activity and a more pronounced induction of cell cycle arrest and apoptosis. In vivo efficacy studies in multiple cell line derived xenograft (CDX) models, the combination of SY-5933 plus CT-707 consistently induced a more potent anti-tumor response than either monotherapy alone. In conclusion, our results demonstrate that CT-707 has the potential to enhance the efficacy of SY-5933 by suppressing adaptive FAK activation under KRAS G12C inhibition. This provides a rationale for an innovative combination therapy to improve outcomes in patients with KRAS G12C mutated cancers. Citation Format: Shuang Liu, Junfen Shi, Chang Lu, Miao Zhang, Ying Xin, Yan Zhu, Jijun Li, Hong Luo, Yinghui Sun. Targeting FAK to improve the therapy of KRAS G12C mutant cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1928.

Abstract 4569: APG-2449, a novel focal adhesion kinase (FAK) inhibitor, inhibits metastasis and enhances the antitumor efficacy of PEGylated liposome doxorubicin (PLD) in epithelial ovarian cancer (EOC)

Abstract Ovarian cancer is the leading cause of cancer-related death in women and most cases are diagnosed at later stages, with distant metastasis. Standard-of-care therapy is surgery followed by platinum and paclitaxel; however, most patients who initially respond to therapy eventually relapse after developing metastatic disease and chemoresistance. FAK overexpression or activation occurs in a substantial proportion of EOCs and is predictive of poor clinical outcomes. Recent studies have reported that FAK plays an important role in cell migration and chemoresistance, rendering FAK inhibition a promising treatment approach to reduce metastasis of tumor cells and sensitize them to chemotherapy. The aim of this study was to evaluate the antitumor efficacy of investigational APG-2449, a novel FAK inhibitor, combined with PLD, a commonly used chemotherapy, in relapsed or refractory ovarian cancer. Four EOC cell lines (OVCAR-3, SK-OV-3, A2780, and Kuramochi) were used for in vitro experiments. Cell proliferation was measured by CellTiter-Glo assays. Cell migration ability was assessed by wound healing assays. OVCAR-3 xenograft and luciferase-tagged ID8 (ID8-Luc) peritoneal syngeneic models were established to evaluate the synergistic antitumor efficacy of combined APG-2449 and PLD in vivo. APG-2449 combined with doxorubicin showed synergistic antiproliferative effects in both platinum-resistant (OVCAR-3 and SK-OV-3) and platinum-sensitive (A2780 and Kuramochi) cell lines. In wound healing assays, FAK inhibition via APG-2449 alone attenuated migration of ovarian cancer cells (SK-OV-3, OVCAR-3, and ID8-Luc) in a dose-dependent manner. In the OVCAR-3 xenograft model, combined APG-2449 and PLD demonstrated enhanced antitumor effects compared with either APG-2449 or PLD monotherapy (synergistic index, 1.33). In the ID8-Luc peritoneal syngeneic model, the combination regimen outperformed PLD or APG-2449 monotherapy in tumor growth inhibition. This inhibitory effect persisted more than 1 month after stopping combination treatment, whereas the monotherapy groups experienced rapid disease relapse. The combination group also exhibited the longest ascites-free and survival times compared with PLD or APG-2449 monotherapy groups. Overall, our data suggest that inhibition of FAK by APG-2449 enhances the antitumor effect of PLD in EOC cell lines and the OVCAR-3 xenograft mouse model. The combination regimen can also prolong ascites-free and survival times, as shown in the ID8-Luc peritoneal syngeneic model. These promising results support future clinical development of this combination treatment for ovarian cancer. Citation Format: Zhou Yu, Eric Liang, Daojie Liu, Bingxing Wu, Xinyi Yao, Yanqiu Ji, Dajun Yang, Yifan Zhai. APG-2449, a novel focal adhesion kinase (FAK) inhibitor, inhibits metastasis and enhances the antitumor efficacy of PEGylated liposome doxorubicin (PLD) in epithelial ovarian cancer (EOC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4569.

Abstract 150: Transcriptional rewiring of BET inhibitor treated Ewing sarcoma cells augments their dependency on focal adhesion kinase

Abstract Outcomes for patients with recurrent and metastatic Ewing sarcoma (EwS) are dismal and novel therapies are needed. As EwS are initiated and maintained by the EWS::FLI1 transcription factor, agents that target aberrant gene transcription are of interest and bromodomain inhibitors (BETi) have shown promise in preclinical models. Nevertheless, despite initial efficacy, BETi tolerance emerges across tumor types, often via transcriptional rewiring. We reasoned that the therapeutic potential of BETi in EwS could be augmented by identifying and targeting mechanisms of drug resistance. To investigate this, we performed transcriptional and phenotypic profiling of BETi-naïve, responsive, and drug-tolerant (DT) EwS cells and used these data to nominate biologically-informed drug combinations. EwS cells (A673, CHLA10, TC32) were exposed for 72 hrs or 20 days to BMS-986158, a clinical grade BETi being tested in a phase I pediatric clinical trial (NCT0393465). A profound cytostatic effect was observed at 72 hrs but in all cell lines proliferation was restored by 20 days. RNA-seq confirmed reversion of the EWS::FLI1-dependent gene signature at 72 hrs and this was maintained at 20 days, demonstrating continued on-target effects despite restored growth of DT cells. Interrogation of differentially expressed genes between drug naïve, cytostatic, and DT cells indicated that that DT cells had been transcriptionally rewired to more mesenchymal states, with notable upregulation of genes involved in integrin signaling. In support of this, DT populations displayed more fibroblastic morphologies, increased F-actin filaments, and enhanced invasion in collagen-rich 3D culture. In parallel, an unbiased kinase inhibitor screen that exploits mathematical modeling revealed that, while BETi-treated cells were overall more resistant than parent cells to kinase inhibitors, their viability depended on focal adhesion kinase (FAK) activity. Western blot confirmed increased phospho-FAK in DT cells. We next tested BMS-986158 and the FAK-inhibitor Defactinib singly or in combination in vitro and in vivo. Defactinib induced cell death in 2D cultures and blocked invasion of 3D spheroids in collagen. Conversely, BMS-986158 enhanced invasive potential in 3D. The combination of Defactinib and BMS-986158 in naïve and DT populations was highly synergistic in 2D assays. In 3D collagen assays, viability and invasion of DT tumor spheroids were significantly reduced by the combination. Finally, ongoing studies show that the combination of FAK and BET inhibition prolongs survival of mice with EwS tumor xenografts. Thus, our studies reveal that exposure of EwS cells to BETi induces transcriptional rewiring that activates integrin and FAK signaling, restoring proliferation. This work supports further investigation of FAKi as agents that could prevent or reverse the BETi tolerant state in EwS. Citation Format: Shireen S. Ganapathi, Emma Wrenn, Nicolas Garcia, Neerja Katiyar, Aya Miyaki, Yuqi Kang, Marina Chan, Taran S. Gujral, Elizabeth R. Lawlor. Transcriptional rewiring of BET inhibitor treated Ewing sarcoma cells augments their dependency on focal adhesion kinase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 150.

Astrocyte focal adhesion kinase reduces passive stress coping by inhibiting ciliary neurotrophic factor only in female mice

Astrocytes have been implicated in stress responses and produce ciliary neurotrophic factor (CNTF), which we have shown in the mouse medial amygdala (MeA) to promote passive stress coping response only in females. Pharmacological inhibition of focal adhesion kinase (FAK) upregulates CNTF expression. Here, we found that inducible knockout of FAK in astrocytes or systemic treatment with an FAK inhibitor increased passive coping behavior, i.e., immobility, in an acute forced swim stress test in female, but not male, mice. Strikingly, four weeks of chronic unpredictable stress (CUS) did not further increase passive coping in female astrocytic FAK knockout mice, whereas it exacerbated it in female wildtype mice and male mice of both genotypes. These data suggest that astrocyte FAK inhibition is required for chronic stress-induced passive coping in females. Indeed, CUS reduced phospho-FAK and increased CNTF in the female MeA. Progesterone treatment after ovariectomy activated amygdala FAK and alleviated ovariectomy-induced passive coping in wildtype, but not astrocytic FAK knockout females. This suggests that progesterone-mediated activation of FAK in astrocytes reduces female stress responses. Finally, astrocytic FAK knockout or FAK inhibitor treatment increased CNTF expression in the MeA of both sexes, although not in the hippocampus. As mentioned, MeA CNTF promotes stress responses only in females, which may explain the female-specific role of astrocytic FAK inhibition. Together, this study reveals a novel female-specific progesterone-astrocytic FAK pathway that counteracts CNTF-mediated stress responses and points to opportunities for developing treatments for stress-related disorders in women.

MCRP-Induced Focal Adhesion Kinase-Dependent Monocyte Aggregation and M1 Polarization, Which Was Partially Blocked by the C10M Inhibitor.

Monomeric C-reactive protein (mCRP) has recently been implicated in the abnormal vascular activation associated with development of atherosclerosis, but it may act more specifically through mechanisms perpetuating damaged vessel inflammation and subsequent aggregation and internalization of resident macrophages. Whilst the direct effects of mCRP on endothelial cells have been characterized, the interaction with blood monocytes has, to our knowledge, not been fully defined. Here we showed that mCRP caused a strong aggregation of both U937 cell line and primary peripheral blood monocytes (PBMs) obtained from healthy donors. Moreover, this increase in clustering was dependent on focal adhesion kinase (FAK) activation (blocked by a specific inhibitor), as was the concomitant adhesive attachment to the plate, which was suggestive of macrophage differentiation. Confocal microscopy confirmed the increased expression and nuclear localization of p-FAK, and cell surface marker expression associated with M1 macrophage polarization (CD11b, CD14, and CD80, as well as iNOS) in the presence of mCRP. Inclusion of a specific CRP dissociation/mCRP inhibitor (C10M) effectively inhibited PBMs clustering, as well as abrogating p-FAK expression, and partially reduced the expression of markers associated with M1 macrophage differentiation. mCRP also increased the secretion of pro-inflammatory cytokines Interleukin-8 (IL-8) and Interleukin-1β (IL-1β), without notably affecting MAP kinase signaling pathways; inclusion of C10M did not perturb or modify these effects. In conclusion, mCRP modulates PBMs through a mechanism that involves FAK and results in cell clustering and adhesion concomitant with changes consistent with M1 phenotypical polarization. C10M has potential therapeutic utility in blocking the primary interaction of mCRP with the cells-for example, by protecting against monocyte accumulation and residence at damaged vessels that may be predisposed to plaque development and atherosclerosis.

The role of adhesion molecules in osteocalcin-induced effects on glucose and lipid metabolism in adipocytes

Recent findings suggest that uncarboxylated osteocalcin (GluOC) promotes glucose and lipid metabolism via its putative receptor GPRC6A; however, its direct effect on adipocytes remains elusive. In this study, we elucidated the effects of GluOC on adipocytes, with an emphasis on the role of cell adhesion molecules. We determined that GluOC promoted the expression of adipocyte adhesion molecule (ACAM) and its transcription factor Krüppel-like factor 4 and enhanced the cortical actin filament assembly, which ameliorated lipid droplet hypertrophy. Additionally, GluOC upregulated the expression of integrin αVβ3 and activation of focal adhesion kinase (FAK) and prevented insulin receptor substrate 1 (IRS1) degradation by inhibiting the ubiquitin–proteasome system via the FAK–PLC–PKC axis, which activated IRS1–Akt-mediated glucose transporter 4 (GLUT4) transport. Furthermore, we showed that GluOC elevated the expression of the insulin-independent glucose transporters GLUT1 and GLUT8, which facilitated insulin stimulation-independent glucose transport. The GluOC-induced activation of integrin αVβ3 signaling promoted microtubule assembly, which improved glucose and lipid metabolism via its involvement in intracellular vesicular transport. GluOC treatment also suppressed collagen type 1 formation, which might prevent adipose tissue fibrosis in obese individuals. Overall, our results imply that GluOC promotes glucose and lipid metabolism via ACAM, integrin αVβ3, and GLUT1 and 8 expression, directly affecting adipocytes.

Roles and inhibitors of FAK in cancer: current advances and future directions.

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that exhibits high expression in various tumors and is associated with a poor prognosis. FAK activation promotes tumor growth, invasion, metastasis, and angiogenesis via both kinase-dependent and kinase-independent pathways. Moreover, FAK is crucial for sustaining the tumor microenvironment. The inhibition of FAK impedes tumorigenesis, metastasis, and drug resistance in cancer. Therefore, developing targeted inhibitors against FAK presents a promising therapeutic strategy. To date, numerous FAK inhibitors, including IN10018, defactinib, GSK2256098, conteltinib, and APG-2449, have been developed, which have demonstrated positive anti-tumor effects in preclinical studies and are undergoing clinical trials for several types of tumors. Moreover, many novel FAK inhibitors are currently in preclinical studies to advance targeted therapy for tumors with aberrantly activated FAK. The benefits of FAK degraders, especially in terms of their scaffold function, are increasingly evident, holding promising potential for future clinical exploration and breakthroughs. This review aims to clarify FAK's role in cancer, offering a comprehensive overview of the current status and future prospects of FAK-targeted therapy and combination approaches. The goal is to provide valuable insights for advancing anti-cancer treatment strategies.

THSD1 Suppresses Autophagy-Mediated Focal Adhesion Turnover by Modulating the FAK-Beclin 1 Pathway.

Focal adhesions (FAs) play a crucial role in cell spreading and adhesion, and their autophagic degradation is an emerging area of interest. This study investigates the role of Thrombospondin Type 1 Domain-Containing Protein 1 (THSD1) in regulating autophagy and FA stability in brain endothelial cells, shedding light on its potential implications for cerebrovascular diseases. Our research reveals a physical interaction between THSD1 and FAs. Depletion of THSD1 significantly reduces FA numbers, impairing cell spreading and adhesion. The loss of THSD1 also induces autophagy independently of changes in mTOR and AMPK activation, implying that THSD1 primarily governs FA dynamics rather than serving as a global regulator of nutrient and energy status. Mechanistically, THSD1 negatively regulates Beclin 1, a central autophagy regulator, at FAs through interactions with focal adhesion kinase (FAK). THSD1 inactivation diminishes FAK activity and relieves its inhibitory phosphorylation on Beclin 1. This, in turn, promotes the complex formation between Beclin 1 and ATG14, a critical event for the activation of the autophagy cascade. In summary, our findings identify THSD1 as a novel regulator of autophagy that degrades FAs in brain endothelial cells. This underscores the distinctive nature of THSD1-mediated, cargo-directed autophagy and its potential relevance to vascular diseases due to the loss of endothelial FAs. Investigating the underlying mechanisms of THSD1-mediated pathways holds promise for discovering novel therapeutic targets in vascular diseases.

Filamin C Deficiency Impairs Sarcomere Stability and Activates Focal Adhesion Kinase through PDGFRA Signaling in Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

Truncating mutations in filamin C (FLNC) are associated with dilated cardiomyopathy and arrhythmogenic cardiomyopathy. FLNC is an actin-binding protein and is known to interact with transmembrane and structural proteins; hence, the ablation of FLNC in cardiomyocytes is expected to dysregulate cell adhesion, cytoskeletal organization, sarcomere structural integrity, and likely nuclear function. Our previous study showed that the transcriptional profiles of FLNC homozygous deletions in human pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are highly comparable to the transcriptome profiles of hiPSC-CMs from patients with FLNC truncating mutations. Therefore, in this study, we used CRISPR-Cas-engineered hiPSC-derived FLNC knockout cardiac myocytes as a model of FLNC cardiomyopathy to determine pathogenic mechanisms and to examine structural changes caused by FLNC deficiency. RNA sequencing data indicated the significant upregulation of focal adhesion signaling and the dysregulation of thin filament genes in FLNC-knockout (FLNCKO) hiPSC-CMs compared to isogenic hiPSC-CMs. Furthermore, our findings suggest that the complete loss of FLNC in cardiomyocytes led to cytoskeletal defects and the activation of focal adhesion kinase. Pharmacological inhibition of PDGFRA signaling using crenolanib (an FDA-approved drug) reduced focal adhesion kinase activation and partially normalized the focal adhesion signaling pathway. The findings from this study suggest the opportunity in repurposing FDA-approved drug as a therapeutic strategy to treat FLNC cardiomyopathy.

Targeting focal adhesion kinase boosts immune response in KRAS/LKB1 co-mutated lung adenocarcinoma via remodeling the tumor microenvironment

BackgroundKRAS mutation is one of the most common oncogenic drivers in NSCLC, however, the response to immunotherapy is heterogeneous owing to the distinct co-occurring genomic alterations. KRAS/LKB1 co-mutated lung adenocarcinoma displays poor response to PD-1 blockade whereas the mechanism remains undetermined.MethodsWe explored the specific characteristics of tumor microenvironment (TME) in KL tumors using syngeneic KRASG12DLKB1−/− (KL) and KRASG12DTP53−/− (KP) lung cancer mouse models. The impact of focal adhesion kinase (FAK) inhibitor on KL lung tumors was investigated in vitro and in vivo through evaluation of both KL cell lines and KL lung cancer mouse models.ResultsWe identified KL tumors as “immune-cold” tumors with excessive extracellular matrix (ECM) collagen deposition that formed a physical barrier to block the infiltration of CD8+T cells. Mechanistically, abundant activated cancer-associated fibroblasts (CAFs) resulted from FAK activation contributed to the formation of the unique TME of KL tumors. FAK inhibition with a small molecular inhibitor could remodel the TME by inhibiting CAFs activation, decreasing collagen deposition and further facilitating the infiltration of anti-tumor immune cells, including CD8+ T cells, DC cells and M1-like macrophages into tumors, hence, converting “immune-cold” KL tumors into “immune-hot” tumors. The combined FAK inhibitor and PD-1 blockade therapy synergistically retarded primary and metastatic tumor growth of KL tumors.ConclusionsOur study identified FAK as a promising intervention target for KL tumors and provided basis for the combination of FAK inhibitor with PD-1 blockade in the management of KL lung cancers.