Targeting FAK in anticancer combination therapies

RGS4 promotes the progression of gastric cancer through the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition

BACKGROUND

Regulator of G protein signaling (RGS) proteins participate in tumor formation and metastasis by acting on the α-subunit of heterotrimeric G proteins. The specific effect of RGS, particularly RGS4, on the progression of gastric cancer (GC) is not yet clear.

AIM

To explore the role and underlying mechanisms of action of RGS4 in GC development.

METHODS

The prognostic significance of RGS4 in GC was analyzed using bioinformatics based public databases and verified by immunohistochemistry and quantitative polymerase chain reaction in 90 patients with GC. Function assays were employed to assess the carcinogenic impact of RGS4, and the mechanism of its possible influence was detected by western blot analysis. A nude mouse xenograft model was established to study the effects of RGS4 on GC growth in vitro.

RESULTS

RGS4 was highly expressed in GC tissues compared with matched adjacent normal tissues. Elevated RGS4 expression was correlated with increased tumor-node-metastasis stage, increased tumor grade as well as poorer overall survival in patients with GC. Cell experiments demonstrated that RGS4 knockdown suppressed GC cell proliferation, migration and invasion. Similarly, xenograft experiments confirmed that RGS4 silencing significantly inhibited tumor growth. Moreover, RGS4 knockdown resulted in reduced phosphorylation levels of focal adhesion kinase, phosphatidyl-inositol-3-kinase, and protein kinase B, decreased vimentin and N-cadherin, and elevated E-cadherin.

CONCLUSION

High RGS4 expression in GC indicates a worse prognosis and RGS4 is a prognostic marker. RGS4 influences tumor progression via the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition.

KRAS mutations in advanced non-small cell lung cancer: From biology to novel therapeutic strategies

Kristen rat sarcoma viral oncogene homolog (KRAS) mutations play a major role in the carcinogenesis of many types of solid tumors including non-small cell lung cancer (NSCLC). Among KRAS mutations, p.G12C single-nucleotide variant (KRASG12C) is the most frequently reported in NSCLC patients, with a prevalence of about 12-13 %. For many decades, KRAS mutations including KRASG12C were considered "undruggable" because of the lack of effective and well-tolerated selective therapies. Noteworthy, CodeBreaK100 and KRYSTAL-1 clinical trials have recently demonstrated that sotorasib and adagrasib, two novel selective KRASG12C inhibitors, have clinical activity with acceptable adverse-event profile for the treatment of advanced NSCLC patients with KRASG12C mutation. On the other hand, no selective therapies are approved for the treatment of advanced NSCLC patients with non-G12C KRAS mutations. As a result, these patients receive the same treatments as those without KRAS mutations. In this paper, we describe the role of KRAS mutations in NSCLC focusing on the clinical and molecular characteristics which potentially identify specific subtypes of NSCLC patients based on different KRAS mutations. We also provide an overview of the main clinical trials testing novel selective KRASG12C inhibitors as well as novel potential therapeutic strategies for NSCLC patients with non-G12C KRAS mutations.

Modeling of FAK-PROTAC candidates from GSK2256098 analogs for targeted protein degradation

Protein inhibition via the traditional drug-designing approach has been shown to be an effective method for developing numerous small-molecule-based therapeutics. In the last decade, small inhibitors-guided protein degradation has arisen as an alternative method with the potential to fulfill the drug requirement for undruggable targets. Focal adhesion kinase (FAK) is a crucial modulator of the growth and spread of tumors, apart from it also acts as a scaffold for signaling of other proteins. FAK inhibitors have thus far had unsatisfactory results in clinical trials for cancer applications. Unlike prior attempts to control FAK expression, which were restricted to kinase domain inhibition with limited success in clinical research, protein degradation has the potential to concurrently disrupt FAK's kinase and scaffolding function. Recently, several FAK degraders were reported based on FAK Type I inhibitors using complex chemical synthesis approaches. Interestingly, recently a ternary complex was published revealing the binding mode of the FAK-PROTAC-E3 complex. This complex opens an avenue for the development of rational PROTAC design against FAK protein. Therefore, in the present study, we selected the most active Type I FAK inhibitor GSK2256098. The binding mode of the inhibitor prompted us to identify the most suitable analog for PROTAC design. We have identified a high-affinity analog that is suitable for PTOTAC design through the application of molecular docking (MD) and molecular dynamics simulations (MDS). Further based on the ternary FAK-PROTAC-E3 complex we build a binary complex FAK-Hit-E3-VHL between both proteins. Using the structure-based approach ten different potential FAK PROTACs candidates were designed. The stability of the complexes was analyzed using MDS and binding free energies were used to predict the binding affinity. Finally, based on desirable intermolecular interactions with the target and E3 ligase ProTAC4 was selected as the best candidate when compared with known FAK PROTAC GSK215.

The integrin adhesome and control of anti-tumour immunity

It is widely regarded that the anti-tumour immune response drives clearance of tumours and leads to prolonged survival in patients. However, tumours are adept at reprogramming the surrounding microenvironment to an immunosuppressive milieu to prevent successful immune directed killing. Adhesion of cells to the extracellular matrix is essential for regulating cellular processes such as survival, proliferation and migration. This adhesion is largely conducted via integrins and their related intracellular signalling networks. Adhesion proteins such as focal adhesion kinase (FAK) are expressed in both tumour cells and cells of the surrounding microenvironment, and are often dysregulated in cancers. Recent work has demonstrated that adhesion proteins are contributing to regulation of the immunosuppressive microenvironment within tumours, and could provide a new avenue to target in combination with immunotherapies. Here, we provide an overview of the effort being made to elucidate the roles adhesion proteins play in modulating anti-tumour responses within a variety of cancer settings. In particular we focus on the multifaceted role of FAK within the tumour immune microenvironment. Finally, we summarise the data in clinical trials, where targeting FAK is being exploited to prime the tumour microenvironment and create potent responses when combined with immunotherapies.

Mechano-assisted strategies to improve cancer chemotherapy

Chemotherapy remains a cornerstone in cancer treatment; however, its effectiveness is frequently undermined by the development of drug resistance. Recent studies underscores the pivotal role of the tumor mechanical microenvironment (TMME) and the emerging field of mechanical nanomedicine in tackling chemo-resistance. This review offers an in-depth analysis of mechano-assisted strategies aimed at mitigating chemo-resistance through the modification of the TMME and the refinement of mechanical nanomedicine delivery systems. We explore the potential of targeting abnormal tumor mechanical properties as a promising avenue for enhancing the efficacy of cancer chemotherapy, which offers novel directions for advancing future cancer therapies, especially from the mechanomedicine perspective.

MFAP2 upregulation promotes ESCC metastasis via FAK-AKT signaling pathway

Metastasis is the leading cause of mortality from esophageal squamous cell carcinoma (ESCC). By the time of diagnosis, most ESCC tumors have already invaded the lymph nodes or distant organs; however, it has been challenging to identify and confirm genes with a crucial role in ESCC metastasis. The microfibrillar-associated protein 2 (MFAP2) is upregulated in human ESCC, and its expression level was positively associated with poor overall and disease-free survival. Consistently, upregulation of MFAP2 promoted the metastasis and invasion of ESCC cells in vitro and in vivo. Conversely, these processes were reduced by MFAP2 knockdown. Mechanistically, MFAP2 was shown to bind to the FERM domain of focal adhesion kinase (FAK) and to alleviate FAK intramolecular inhibition, resulting in the enhanced binding affinity between FAK and integrin beta 4 (ITGB4) and activation of the FAK-AKT signaling pathway. Treatment of ESCC cells with the FAK inhibitor PND-1186 reduced MFAP2, induced the activation of the FAK-AKT pathway in vitro, and suppressed lung metastasis in a mouse model of ESCC. These findings support a major role for MFAP2 in promoting ESCC metastasis, in part via the activation of FAK-AKT signaling, and highlight the potential of MFAP2 as a promising therapeutic target for ESCC.

Development of novel focal adhesion kinase (FAK) inhibitors for targeting cancer: Structural insights and therapeutic potential

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase frequently overexpressed in various cancer cells, facilitating tumor growth through the regulation of cell adhesion, migration, and proliferation. Consequently, targeting FAK is considered a promising anti-tumor strategy, particularly for invasive cancers. Numerous potent small-molecule inhibitors have progressed to clinical trials. Among these, Defactinib is under evaluation for regulatory approval as a treatment for ovarian serous tumors. Furthermore, novel FAK inhibitors, including PROTACs, have emerged as key research focuses, anticipated to overcome the limitations of traditional inhibitors. In this Perspective, we highlight the protein structure, biological functions, relevant signaling pathways, and associations of FAK with cancer development. We also analyze the clinical status of FAK inhibitors, paying special attention to the various classes of FAK inhibitors, with detailed analyses of their chemical structures, structure-activity relationships (SARs), bioactivity profiles, selectivity profiles, and therapeutic potentials.

Activated PARP1/FAK/COL5A1 signaling facilitates the tumorigenesis of cholesterol-resistant ovarian cancer cells through promoting EMT

Cancer cells require plentiful cholesterol for membrane biogenesis and other functional needs due to fast proliferating, leading to the interaction of cholesterol or its metabolites with cancer-related pathways. However, the impact of long-lasting high cholesterol concentrations on tumorigenesis and its underlying mechanisms remains largely unexplored. To the best of our knowledge, this study is the first to establish a cholesterol-resistant ovarian cancer cells, whose intracellular total cholesterol level up to 6-8 mmol/L. We confirmed that high cholesterol facilitated the progression of ovarian cancer in vitro and in vivo. Notably, our findings revealed significant upregulation of collagen type V alpha 1 chain (COL5A1) expression in cholesterol-resistant ovarian cancer cells and human ovarian cancer tissue, which was depended on FAK/Src activation. Mechanistically, PARP1 directly bound to FAK in response to activate FAK/Src/COL5A1 signaling. Intriguingly, COL5A1 depletion significantly impeded the tumorigenesis of these cells, concomitant with a decrease in epithelial-mesenchymal transition (EMT) progression. In conclusion, PARP1/FAK/COL5A1 signaling activation facilitated progression of cholesterol-resistant ovarian cancer cells by promoting EMT, thereby broadening a new therapeutic opportunity.

ADAR1 Promotes Invasion and Migration and Inhibits Ferroptosis via the FAK/AKT Pathway in Colorectal Cancer

The role of adenosine deaminase acting on RNA1 (ADAR1) in colorectal cancer (CRC) is poorly understood. This study investigated the roles and underlying molecular mechanisms of ADAR1 and its isoforms, explored the correlations between ADAR1 expression and the immune microenvironment and anticancer drug sensitivity, and examined the potential synergy of using ADAR1 expression and clinical parameters to determine the prognosis of CRC patients. CRC samples showed significant upregulation of ADAR1, and high ADAR1 expression was correlated with poor prognosis. Silencing ADAR1 inhibited the proliferation, invasion, and migration of CRC cells and induced ferroptosis by suppressing FAK/AKT activation, and the results of rescue assays were consistent with these mechanisms. Both ADAR1-p110 and ADAR1-p150 were demonstrated to regulate the FAK/AKT pathway, with ADAR1-p110 playing a particularly substantial role. In evaluating the prognosis of CRC patients, combining ADAR1 expression with clinical parameters produced a substantial synergistic effect. The in vivo tumorigenesis of CRC was significantly inhibited by silencing ADAR1. Furthermore, ADAR1 expression was positively correlated with tumor mutational burden (TMB) and microsatellite status (p < 0.05), indicating that ADAR1 plays a complex role in CRC immunotherapy. In conclusion, ADAR1 plays oncogenic roles in CRC both in vitro and in vivo, potentially by inhibiting ferroptosis via downregulation of the FAK/AKT pathway. Thus, ADAR1 serves as a potential prognostic biomarker and a promising target for CRC therapy.

Defactinib inhibits FAK phosphorylation and regulates psoriasis via attenuating hyperproliferation of keratinocytes

Excessive proliferation of keratinocytes is a crucial pathological risk feature of psoriasis. Focal adhesion kinase (FAK) is a non-receptor protein that primarily regulates cell proliferation and migration. However, the expression and regulatory mechanism of FAK in psoriasis remains unclear. This study aimed to investigate the regulation of FAK in psoriasis and examined the potential impact of FAK inhibitor on psoriasis. A small molecular selective FAK inhibitor, defactinib, was used to evaluate the effect of FAK on psoriasis in in vitro and in vivo functional assays. In our experiments, imiquimod (IMQ)-induced psoriasis mice and human keratinocytes cells were used to study the potential roles and mechanisms of FAK in psoriasis. FAK phosphorylation has been weakly detected in normal intact skin and is markedly elevated upon IMQ treatment. By reducing FAK phosphorylation (p-FAK), defactinib treatment could attenuate psoriasiform inflammation and epidermal hyperplasia in IMQ-treated mice compared with IMQ-induced mice treated with the vehicle. In in vitro studies, resiquimod (R848) increased (p-FAK) and promoted cell proliferation in human keratinocytes cells, while defactinib reversed this effect. Mechanistically, defactinib can alleviate the proliferation via JNK/YB1 pathway in vitro and in vivo. Defactinib significantly attenuates psoriasiform inflammation and epidermal hyperproliferation through the inhibition of the FAK-mediated axis. The downregulation of phosphorylated FAK then suppressed the activation of JNK/YB1 protein signaling pathway in psoriasis. Our work highlights targeting FAK as a potentially effective strategy for the treatment of psoriasis.

Targeted delivery of FAK siRNA by engineered exosomes to reverse cetuximab resistance via activating paraptosis in colon cancer

BACKGROUND

Cetuximab is extensively used in the treatment of metastatic colorectal cancer (mCRC). However, resistance poses a significant challenge to successful therapy. Recently, paraptosis, a non-classical programmed cell death, has garnered increased attention for its potential application value in antitumor treatments. We aimed to identify the essential pathways and signaling molecules involved in paraptosis inhibition and select them as therapeutic targets in cetuximab resistance. Additionally, engineered exosome technology is used as a drug delivery system with both targeted and effector properties.

RESULTS

By comparing the differential expression of paraptosis-related genes between drug-resistant colon cancer cells and sensitive cells, it was observed that the paraptosis level induced by cetuximab was significantly downregulated in drug-resistant cells. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified the focal adhesion kinase (FAK) signaling pathway as a key pathway involved in the suppression of paraptosis. The biological function of FAK in cetuximab-resistant cells was investigated through cell morphology observation, CCK-8 assay, colony formation assay, RT-qPCR, Western Blot, and loss-of-function experiments. The results showed that the FAK signaling pathway was significantly upregulated in cetuximab-resistant colon cancer cells, and siRNA interference targeting FAK could notably inhibit cell proliferation while upregulating the paraptosis level. Based on this, engineered colon cancer cells targeted and FAK siRNA loaded exosomes (CT-Exo-siFAK1) were constructed. In vitro experiments, CT-Exo-siFAK1 could effectively activate paraptosis and inhibit the proliferation of drug-resistant colon cancer cells. In vivo experiments also confirmed that CT-Exo-siFAK1 significantly suppressed tumor growth and metastasis while upregulating the paraptosis level.

CONCLUSION

This study suggests that FAK signaling pathway-mediated inhibition of paraptosis levels is crucial in the sensitivity of cetuximab targeted therapy in colon cancer, and the use of engineered exosomes to deliver FAK siRNA may be an effective strategy to reverse cetuximab resistance.

Nuclear Focal Adhesion Kinase Protects against Cisplatin Stress in Ovarian Carcinoma

SIGNIFICANCE

FAK inhibitors are in combinatorial clinical testing with agents that prevent Ras-Raf-MAPK pathway activation in various cancers. This study suggests that nuclear FAK limits ERK/MAPK activation in supporting HGSOC cell survival to cisplatin stress. Overall, it is likely that targets of FAK-mediated survival signaling may be tumor type- and context-dependent.

Targeted inhibition of CHKα and mTOR in models of pancreatic ductal adenocarcinoma: A novel regimen for metastasis

Pancreatic ductal adenocarcinoma (PDAC) is a highly metastatic malignancy for which there are currently no effective anti-metastatic therapies. Herein, we employed single-cell RNA sequencing and metabolomics analysis to demonstrate that metastatic cells highly express focal adhesion kinase (FAK), which promotes metastasis by remodeling choline kinase α (CHKα)-dependent choline metabolism. We designed a novel CHKα inhibitor, CHKI-03, and verified its efficacy in inhibiting metastasis in multiple preclinical models. Classical and newly synthesized small-molecule inhibitors have previously been used to assess the therapeutic potential of targeting mTOR and CHKα in various animal models. Mechanistically, FAK activated mTOR and its downstream HIF-1α, thereby elevating CHKα expression and promoting the proliferation, migration, and invasion of PDAC cells, as well as tumor growth and metastasis. Consistently, high expression levels of both FAK and CHKα are correlated with poor prognosis in patients with PDAC. Notably, CHK1-03 inhibited CHKα expression and also suppressed mTORC1 phosphorylation, disrupting the mTORC1-CHKα positive feedback loop. In addition, the combination of CHKI-03 and the mTORC1 inhibitor rapamycin synergistically inhibited tumor growth and metastasis in PDX models. The combination of CHKI-03 and rapamycin demonstrates considerable therapeutic efficacy in PDO models resistant to gemcitabine. Our findings reveal a pivotal mechanism underlying PDAC metastasis regulated by mTORC1-CHKα loop-dependent choline metabolism reprogramming, highlighting the therapeutic potential of this novel regimen for treating PDAC metastasis.

Spatial organization of PI3K-PI(3,4,5)P3-AKT signaling by focal adhesions

The class I phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway is a key regulator of cell survival, growth, and proliferation and is among the most frequently mutated pathways in cancer. However, where and how PI3K-AKT signaling is spatially activated and organized in mammalian cells remains poorly understood. Here, we identify focal adhesions (FAs) as subcellular signaling hubs organizing the activation of PI3K-PI(3,4,5)P3-AKT signaling in human cancer cells containing p110α mutations under basal conditions. We find that class IA PI3Ks are preferentially recruited to FAs for activation, resulting in localized production of PI(3,4,5)P3 around FAs. As the effector protein of PI(3,4,5)P3, AKT1 molecules are dynamically recruited around FAs for activation. The spatial recruitment/activation of the PI3K-PI(3,4,5)P3-AKT cascade is regulated by activated FA kinase (FAK). Furthermore, combined inhibition of p110α and FAK results in a more potent inhibitory effect on cancer cells. Thus, our results unveil a growth-factor independent, compartmentalized organization mechanism for PI3K-PI(3,4,5)P3-AKT signaling.

Additively Manufactured Biodegradable Zn-Based Porous Scaffolds to Suppress Osteosarcoma and Promote Osteogenesis

Postoperative therapies for osteosarcoma present substantial challenges due to tumor recurrence and extensive bone defects. To tackle these challenges, laser powder bed fusion is utilized to fabricate biodegradable Zn-Li porous scaffolds that supress tumors and promote osteogenesis. After the structure design and composition selection, the Zn-0.8Li porous scaffold with Gyroid unit optimally balances the co-release of Zn2+ and Li+ during degradation, resulting in favorable antitumor and osteogenic effects. In vitro, the Zn-0.8Li scaffold significantly inhibits osteosarcoma progression by suppressing tumor cell proliferation, promoting apoptosis, alleviating migration, and simultaneously promotes osteogenic differentiation through the enhanced expression of osteogenic markers. In vivo, the Zn-0.8Li scaffold inhibits the malignant osteosarcoma behavior and facilitates bone regeneration in areas with bone defects. Transcriptomic analysis further reveals that the simultaneous release of Zn2+ and Li+ from the biodegradable Zn-0.8Li scaffold contributes to anti-osteosarcoma activity by downregulating PI3K/Akt signaling pathways. Taken together, the Zn-0.8Li porous scaffold fabricated using laser powder bed fusion with enhanced antitumor and osteogenic properties is a promising alternative for the postoperative management of osteosarcoma.

Prognostic signature and immunotherapeutic relevance of Focal adhesion signaling pathway-related genes in osteosarcoma

Background

As the most common primary malignant bone tumor in children and adolescents, osteosarcoma currently lacks an effective clinical cure. Focal adhesion plays a crucial role in tumor invasion, migration, and drug resistance by mediating communication between the extracellular matrix and tumor cells. This study investigated the prognostic features and immunotherapeutic relevance of focal adhesion pathway-related genes in osteosarcoma to aid in the development of new therapeutic options.

Methods

We obtained mutational, transcriptomic, gene expression, and clinical data of osteosarcoma patients from the Gene Expression Omnibus (GEO) and Therapeutically Applicable Research to Generate Effective (TARGET) databases. Differentially expressed genes were screened, followed by the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses. Kaplan-Meier survival analysis was performed for genes related to the focal adhesion pathway, and multivariate Cox regression analysis was employed to construct a prognostic signature model. Genes such as SIGLEC15, TIGIT, CD274, HAVCR2, PDCD1, CTLA4, and LAG3 were extracted from the TARGET and CCLE databases for osteosarcoma patients and osteosarcoma cell lines, respectively，to observe the expression of immune checkpoint-related genes. Finally, qRT-PCR was used to verify the expression of these immune checkpoint-related genes in osteosarcoma cell lines.

Results

In our study, 376 samples were analyzed, including 369 osteosarcoma samples and 7 normal tissue samples. We identified 50 up-regulated and 28 down-regulated differentially expressed genes. Among these, 10 Candidate genes relative to focal Adhesion were selected， and CAV1, ZYX, and ITGA5 were found to have a significant prognostic role based on survival analysis of osteosarcoma samples from the TARGET database. A predictive signature model related to the focal adhesion signaling pathway was constructed using these genes, and the AUCs of the 1-year, 3-year, and 5-year ROC curves were 0. 647, 0. 712, and 0. 717, respectively. The overall survival (OS) rate of osteosarcoma patients with high-risk scores was poorer than those with low-risk scores. Then, samples were divided into two subgroups based on the expression of the three genes, revealing significant differences in the expression of certain immune checkpoint-related genes between the subgroups. Additionally, above three genes and immune checkpoint-related genes in osteosarcoma cell lines were extracted from the CCLE database, showing high expression levels in eight osteosarcoma cell lines. We observed that CD274 and PDCD1LG2 were highly expressed in some osteosarcoma cell lines. Finally, the expression of CAV1, ZYX, ITGA5, CD80, CD274, and PDCD1LG2 in osteosarcoma cell lines was verified by qRT-PCR.

Conclusions

Our study validated the prognostic role of three focal adhesion pathway-related genes (ZYX, CAV1, and ITGA5) in patients with osteosarcoma and constructed a prognostic signature model associated with the focal adhesion signaling pathway. We identified significant differences in the expression of multiple immune checkpoint-related genes among subgroups defined by the three genes. Additionally, CD274 and PDCD1LG2 showed higher expression in osteosarcoma cell lines characterized by these genes. These findings may aid in the selection of effective immunotherapy for specific osteosarcoma patients.

Integration of Machine Learning and Experimental Validation to Identify Anoikis-Related Prognostic Signature for Predicting the Breast Cancer Tumor Microenvironment and Treatment Response

Background/Objectives: Anoikis-related genes (ANRGs) are crucial in the invasion and metastasis of breast cancer (BC). The underlying role of ANRGs in the prognosis of breast cancer patients warrants further study. Methods: The anoikis-related prognostic signature (ANRS) was generated using a variety of machine learning methods, and the correlation between the ANRS and the tumor microenvironment (TME), drug sensitivity, and immunotherapy was investigated. Moreover, single-cell analysis and spatial transcriptome studies were conducted to investigate the expression of prognostic ANRGs across various cell types. Finally, the expression of ANRGs was verified by RT-PCR and Western blot analysis (WB), and the expression level of PLK1 in the blood was measured by the enzyme-linked immunosorbent assay (ELISA). Results: The ANRS, consisting of five ANRGs, was established. BC patients within the high-ANRS group exhibited poorer prognoses, characterized by elevated levels of immune suppression and stromal scores. The low-ANRS group had a better response to chemotherapy and immunotherapy. Single-cell analysis and spatial transcriptomics revealed variations in ANRGs across cells. The results of RT-PCR and WB were consistent with the differential expression analyses from databases. NU.1025 and imatinib were identified as potential inhibitors for SPIB and PLK1, respectively. Additionally, findings from ELISA demonstrated increased expression levels of PLK1 in the blood of BC patients. Conclusions: The ANRS can act as an independent prognostic indicator for BC patients, providing significant guidance for the implementation of chemotherapy and immunotherapy in these patients. Additionally, PLK1 has emerged as a potential blood-based diagnostic marker for breast cancer patients.

LncRNA FAISL Inhibits Calpain 2-Mediated Proteolysis of FAK to Promote Progression and Metastasis of Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is the most aggressive subtype in breast tumors. When re-analyzing TCGA breast cancer dataset, we found cell adhesion molecules are highly enriched in differentially expressed genes in TNBC samples, among which Focal Adhesion Kinase (FAK) is most significantly associated with poor survival of TNBC patients. FAK is precisely modulated in the focal adhesion dynamics. To investigate whether lncRNAs regulate FAK signaling, we performed RNA immunoprecipitation sequencing and found FAISL (FAK Interacting and Stabilizing LncRNA) abundantly enriched in FAK-interacting lncRNAs and frequently overexpressed in TCGA TNBC tissues. FAISL promotes TNBC cell adhesion, cytoskeleton spreading, proliferation, and anchor-independent survival. FAISL doesn't affect FAK mRNA but positively regulates FAK protein level by blocking Calpain 2-mediated proteolysis. FAISL interacts with the C-terminus domain of FAK, whereby masks the binding site of Calpain 2 and prevents FAK cleavage. High level of FAISL correlates with FAK expression in tumor tissues and poor prognosis of TNBC patients. A siRNA delivery system targeting FAISL using reduction-responsive nanoparticles effectively inhibits tumor growth and metastasis in TNBC mouse models. Together, these findings uncover a lncRNA-mediated mechanism of regulating FAK proteolysis in the TNBC progression, and highlight the potential of targeting lncRNA FAISL for TNBC treatment.

Targeting a key FAK-tor: the therapeutic potential of combining focal adhesion kinase (FAK) inhibitors and chemotherapy for chemoresistant non-small cell lung cancer

INTRODUCTION

NSCLC is the leading cause of cancer-related deaths globally, with a low survival rate primarily due to NSCLC frequently becoming chemoresistant. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase involved in pathways regulating multiple processes in the cell, including survival, migration, and the TME, that contribute to both tumor progression and drug resistance. Recently, FAK inhibitors (FAKi) have shown promising potential for the treatment of NSCLC.

AREAS COVERED

This narrative review aims to summarize key signaling pathways involving FAK that contribute to tumor progression and drug resistance. It will further provide an overview of FAKi currently in pre- and early-phase clinical trials for solid tumors, as well as the therapeutic potential of combining FAKi with chemotherapy, as this has emerged as a promising strategy to overcome chemoresistance in NSCLC.

EXPERT OPINION

It is becoming increasingly clear that FAK is not an oncogenic driver but rather contributes to tumor progression and drug resistance. Hence, while FAKi have only demonstrated modest results in clinical trials when given by themselves, treatment regimens combining other therapies with FAKi have shown promising potential to overcome drug resistance. Lastly, of particular novelty are FAK-PROTACs (proteolysis-targeting chimaeras), which uniquely target both cytosolic and nuclear FAK.

Targeting extracellular matrix interaction in gastrointestinal cancer: Immune modulation, metabolic reprogramming, and therapeutic strategies

The extracellular matrix (ECM) is a major constituent of the tumor microenvironment, acting as a mediator that supports the progression of gastrointestinal (GI) cancers, particularly in mesenchymal subtypes. Beyond providing structural support, the ECM actively shapes the tumor microenvironment (TME) through complex biochemical and biomechanical remodeling. Dysregulation of ECM composition and signaling is closely linked to increased cancer aggressiveness, poor prognosis, and resistance to therapy. ECM components, such as collagen, fibronectin, laminin, and periostin, influence tumor growth, metastasis, immune modulation, and metabolic reprogramming by interacting with tumor cells, immune cells, and cancer-associated fibroblasts. In this review, we highlight the heterogeneous nature of the ECM and the dualistic roles of its components across GI cancers, with a focus on their contributions to immune evasion and metabolic remodeling via intercellular interactions. Additionally, we explore therapeutic strategies targeting ECM remodeling and ECM-centered interactions, emphasizing their potential in enhancing existing anti-tumor therapies.

Decoding PTEN: from biological functions to signaling pathways in tumors

The tumor suppressor gene Phosphatase and tensin homologue deleted on chromosome 10 (PTEN), possessing both protein and lipid phosphatase activities, is frequently mutated in various human cancers. PTEN aberrations disrupt critical cellular processes like proliferation, apoptosis, migration, and invasion, thereby promoting tumor growth. In the cells, PTEN localizes to the nucleus, cytoplasm, or cell membrane, and its roles depends on the subcellular localization. PTEN is regulated at the transcriptional, post-transcriptional, and post-translational levels, implying that its functions on the tumors are complex. The relationship between PTEN abnormalities and tumors has garnered significant interest in recent years. PTEN regulates essential cellular processes involved in tumorigenesis. Mutations or deletions in the PTEN gene often correlate with unfavorable prognosis and increased cancer recurrence. Numerous studies suggest that PTEN expression levels in tumors could be a valuable biomarker for cancer diagnosis, treatment, and predicting patient outcomes. This paper provides a comprehensive review of the biological function, regulatory mechanisms, and post-translational modifications of PTEN. Furthermore, this review explores the expression and regulation of PTEN in different tumor types, as well as its interactions with environmental factors in tumorigenesis. This comprehensive analysis aims to deepen our understanding of the signaling pathways between PTEN and cancer.

Targeting focal adhesion kinase (FAK) in cancer therapy: A recent update on inhibitors and PROTAC degraders

Focal adhesion kinase (FAK) is considered as a pivotal intracellular non-receptor tyrosine kinase, and has garnered significant attention as a promising target for anticancer drug development. As of early 2024, a total of 12 drugs targeting FAK have been approved for clinical or preclinical studies worldwide, including three PROTAC degraders. In recent three years (2021-2023), significant progress has been made in designing targeted FAK anticancer agents, including the development of a novel benzenesulfofurazan type NO-releasing FAK inhibitor and the first-in-class dual-target inhibitors simultaneously targeting FAK and HDACs. Given the pivotal role of FAK in the discovery of anticancer drugs, as well as the notable advancements achieved in FAK inhibitors and PROTAC degraders in recent years, this review is underbaked to present a comprehensive overview of the function and structure of FAK. Additionally, the latest findings on the inhibitors and PROTAC degraders of FAK from the past three years, along with their optimization strategies and anticancer activities, were summarized, which might help to provide novel insights for the development of novel targeted FAK agents with promising anticancer potential and favorable pharmacological profiles.

Comprehensive pan-cancer analysis reveals prognostic implications of TMEM92 in the tumor immune microenvironment

BACKGROUND

Transmembrane protein 92 (TMEM92) has been implicated in the facilitation of tumor progression. Nevertheless, comprehensive analyses concerning the prognostic significance of TMEM92, as well as its role in immunological responses across diverse cancer types, remain to be elucidated.

METHODS

In this study, data was sourced from a range of publicly accessible online platforms and databases, including TCGA, GTEx, UCSC Xena, CCLE, cBioPortal, HPA, TIMER2.0, GEPIA, CancerSEA, GDSC, exoRBase, and ImmuCellAI. We systematically analyzed the expression patterns of TMEM92 at both mRNA and protein levels across diverse human organs, tissues, extracellular vesicles (EVs), and cell lines associated with multiple cancer types. Subsequently, analyses were conducted to determine the relationship between TMEM92 and various parameters such as prognosis, DNA methylation, copy number variation (CNV), the tumor microenvironment (TME), immune cell infiltration, genes with immunological relevance, tumor mutational burden (TMB), microsatellite instability (MSI), mismatch repair (MMR), and half-maximal inhibitory concentration (IC50) values.

RESULTS

In the present study, we observed a pronounced overexpression of TMEM92 across a majority of cancer types, which was concomitantly associated with a less favorable prognosis. A notable association emerged between TMEM92 expression and both DNA methylation and CNV. Furthermore, a pronounced relationship was discerned between TMEM92 expression, the TME, and the degree of immune cell infiltration. Intriguingly, while TMEM92 expression displayed a positive correlation with macrophage presence, it inversely correlated with the infiltration level of CD8 +  T cells. Concurrently, significant associations were identified between TMEM92 and the major histocompatibility complex, TMB, MSI, and MMR. Results derived from Gene Set Enrichment Analysis and Gene Set Variation Analysis further substantiated the nexus of TMEM92 with both immune and metabolic pathways within the oncogenic context.

CONCLUSIONS

These findings expanded the understanding of the roles of TMEM92 in tumorigenesis and progression and suggest that TMEM92 may have an immunoregulatory role in several malignancies.

Exploiting mechanoregulation via FAK/YAP to overcome platinum resistance in ovarian cancer

Cancer cells mechanically interact with the tumor microenvironment during cancer development. Mechano-reciprocity has emerged as a crucial factor affecting anti-cancer drug resistance during adjuvant therapy. Here, we investigated the focal adhesion kinase (FAK)/Yes-associated protein (YAP) signaling axis as a prospective strategy for circumventing cisplatin resistance in ovarian cancer (OC). The Cancer Genome Atlas (TCGA) data analysis revealed that FAK overexpression significantly correlated with unfavorable clinical outcomes in patients with ovarian cancer. AFM indentation experiments showed that cell elasticity depends on FAK activity. Notably, the combination of FAK inhibition and cisplatin treatment led to a 69 % reduction in the IC50 of cisplatin. This combined treatment also increased apoptosis compared to the individual treatments, along with the upregulation of the pro-apoptotic factor BAX and cleaved PARP. Suppressing FAK expression sequestered YAP in the cytosol, potentially reducing cellular proliferation and promoting apoptosis. Moreover, reduced FAK expression sensitized drug-resistant OC cells to cisplatin treatment owing to a decrease in nuclear tension, allowing the relocation of YAP to the cytosol. In a mouse model, the co-administration of an FAK inhibitor and cisplatin significantly suppressed tumor growth and increased apoptotic events and DNA fragmentation. Our findings suggest that drug resistance can be attributed to the perturbation of mechanosensing signaling pathways, which drive the mechanical reinforcement of cancer cells. OC cells can restore their sensitivity to cisplatin treatment by strategically reducing YAP localization in the nucleus through FAK downregulation.

A novel FAK-degrading PROTAC molecule exhibited both anti-tumor activities and efficient MDR reversal effects

FAK (focal adhesion kinase) is widely involved in cancer growth and drug resistance development. Thus, FAK inhibition has emerged as an effective strategy for tumor treatment both as a monotherapy or in combination with other treatments. But the current FAK inhibitors mainly concentrate on its kinase activity, overlooking the potential significance of FAK scaffold proteins. In this study we employed the PROTAC technology, and designed a novel PROTAC molecule F2 targeting FAK based on the FAK inhibitor IN10018. F2 exhibited potent inhibitory activities against 4T1, MDA-MB-231, MDA-MB-468 and MDA-MB-435 cells with IC50 values of 0.73, 1.09, 5.84 and 3.05 μM, respectively. On the other hand, F2 also remarkably reversed the multidrug resistance (MDR) in HCT8/T, A549/T and MCF-7/ADR cells. Both the effects of F2 were stronger than the FAK inhibitor IN10018. To our knowledge, F2 was the first reported FAK-targeted PROTAC molecule exhibiting reversing effects on chemotherapeutic drug resistance, and its highest reversal fold could reach 158 times. The anti-tumor and MDR-reversing effects of F2 might be based on its inhibition on AKT (protein kinase B, PKB) and ERK (extracellular signal-regulated kinase) signaling pathways, as well as its impact on EMT (epithelial-mesenchymal transition). Furthermore, we found that F2 could reduce the protein level of P-gp in HCT8/T cells, thereby contributing to reverse drug resistance from another perspective. Our results will boost confidence in future research focusing on targeting FAK and encourage further investigation of PROTAC with potent in vivo effects.

Unveiling the Role of Mechanical Microenvironment in Hepatocellular Carcinoma: Molecular Mechanisms and Implications for Therapeutic Strategies

Hepatocellular carcinoma (HCC) is the sixth most common cancer in the world and the third leading cause of cancer deaths globally. More than 80% of HCC patients have a background of fibrosis or cirrhosis, which leads to changes in physical factors in tumor microenvironment (TME), such as increased stiffness, solid stress, fluid stresses and structural alterations in the extracellular matrix (ECM). In the past, the focus of cancer research has predominantly been on genetic and biochemical factors in the TME, and the critical role of physical factors has often been overlooked. Recent discoveries suggest these unique physical signals are converted into biochemical signals through a mechanotransduction process that influences the biological behavior of tumor cells and stromal cells. This process facilitates the occurrence and progression of tumors. This review delves into the alterations in the mechanical microenvironment during the progression of liver fibrosis to HCC, the signaling pathways activated by physical signals, and the effects on both tumor and mesenchymal stromal cells. Furthermore, this paper summarizes and discusses the therapeutic options for targeting the mechanical aspects of the TME, offering valuable insights for future research into novel therapeutic avenues against HCC and other solid tumors.

Stress granule formation enables anchorage-independence survival in cancer cells

Stress granules (SGs) are dynamic cytoplasmic structures assembled in response to various stress stimuli that enhance cell survival under adverse environmental conditions. Here we show that SGs contribute to breast cancer progression by enhancing the survival of cells subjected to anoikis stress. SG assembly is triggered by inhibition of Focal Adhesion Kinase (FAK) or loss of adhesion signals. Combined proteomic analysis and functional studies reveal that SG formation enhances cancer cell proliferation, resistance to metabolic stress, anoikis resistance, and migration. Importantly, inhibiting SG formation promotes the sensitivity of cancer cells to FAK inhibitors being developed as cancer therapeutics. Furthermore, we identify the Rho-ROCK- PERK-eIF2α axis as a critical signaling pathway activated by loss of adhesion signals and inhibition of the FAK-mTOR-eIF4F complex in breast cancer cells. By triggering SG assembly and AKT activation in response to anoikis stress, PERK functions as an oncoprotein in breast cancer cells. Overall, our study highlights the significance of SG formation in breast cancer progression and suggests that therapeutic inhibition of SG assembly may reverse anoikis resistance in treatment-resistant cancers such as triple-negative breast cancer (TNBC).

Highlights

Either anoikis stress or loss of adhesion induce stress granule (SG) formationThe Rho-ROCK-PERK-eIF2α axis is a crucial signaling pathway triggered by the absence of adhesion signals, leading to the promotion of SG formation along with the inhibition of the FAK- AKT/mTOR-eIF4F complex under anoikis stress.PERK functions as an oncogene in breast cancer cells, initiating SG formation and activating AKT under anoikis stress.Inhibiting SG formation significantly enhances the sensitivity to Focal Adhesion Kinase (FAK) inhibitors, suggesting a potential for combined therapy to improve cancer treatment efficacy.

Focal adhesion kinase-mediated interaction between tumor and immune cells in the tumor microenvironment: implications for cancer-associated therapies and tumor progression

Focal adhesion kinase (FAK) expression has been linked to tumor growth, immunosuppression, metastasis, angiogenesis, and therapeutic resistance through kinase-dependent and kinase scaffolding functions in the nucleus and cytoplasm. Hence, targeting FAK alone or with other agents has gained attention as a potential therapeutic strategy. Moreover, mounting evidence shows that FAK activity can influence the tumor immune microenvironment crosstalk to support tumor progression. Recently, tumor immune microenvironment interaction orchestrators have shown to be promising therapeutic agents for cancer immunotherapies. Therefore, this review highlights how FAK regulates the tumor immune microenvironment interplay to promote tumor immune evasive mechanisms and their potential for combination therapies with standard cancer treatments.

Exosomal circZNF800 Derived from Glioma Stem-like Cells Regulates Glioblastoma Tumorigenicity via the PIEZO1/Akt Axis

Exosomes play a crucial role in regulating crosstalk between tumor and tumor stem-like cells through their cargo molecules. Circular RNAs (circRNAs) have recently been demonstrated to be critical factors in tumorigenesis. This study focuses on the molecular mechanism by which circRNAs from glioma stem-like cell (GSLC) exosomes regulate glioblastoma (GBM) tumorigenicity. In this study, we validated that GSLC exosomes accelerated the malignant phenotype of GBM. Subsequently, we found that circZNF800 was highly expressed in GSLC exosomes and was negatively associated with GBM patients. CircZNF800 promoted GBM cell proliferation and migration and inhibited GBM cell apoptosis in vitro. Silencing circZNF800 could improve the GBM xenograft model survival rate. Mechanistic studies revealed that circZNF800 activated the PIEZO1/Akt signaling pathway by sponging miR-139-5p. CircZNF800 derived from GSLC exosomes promoted GBM cell tumorigenicity and predicted poor prognosis in GBM patients. CircZNF800 has the potential to serve as a promising target for further therapeutic exploration.

Exosomal CTHRC1 from cancer-associated fibroblasts facilitates endometrial cancer progression via ITGB3/FAK signaling pathway

The emerging tumor microenvironment (TME) is a complex and constantly evolving entity. Cancer-associated fibroblasts (CAFs) are a vital component of the TME with diverse functions. They interact closely with cancer cells through reciprocal signaling and play a crucial role in tumor progression. Exosomes, which contain diverse biological information, are identified as an important mediator of cell-cell communication. This study aimed to investigate how CAF-derived exosomes promote metastasis of endometrial cancer (EC). Our findings revealed that CAF-derived exosomes significantly enhanced EC cell proliferation and migration compared to normal fibroblast-derived exosomes. Quantitative proteomics analysis of CAF/NF-derived exosomes demonstrated differential expression of CTHRC1, a protein overexpressed in multiple tumors, promoting cancer progression through enhanced cell migration and invasion. Exosomal overload of CTHRC1 significantly contributes to EC cell migration. Mechanically, we determined that ITGB3 was immunoprecipitated by CTHRC1 and phosphorylated FAK on Tyr397, which was important for exosomal CTHRC1 mediated migratory ability of EC cells. Overexpression of CTHRC1 in secreted exosomes promotes the metastatic ability of EC cells in mouse models and may be eliminated by Defactinib, an inhibitor of FAK Tyr397 phosphorylation. Moreover, overexpression of CTHRC1 was increased in EC patients, elevating with cancer progression, and correlated with negative tumor prognosis. Our results revealed that CAF mediated endometrial cancer progression is related to high levels of CTHRC1 and exosomal CTHRC1 derived from CAF may be a promising therapeutic strategy for metastatic endometrial cancer.

Non-Receptor Tyrosine Kinases: Their Structure and Mechanistic Role in Tumor Progression and Resistance

Protein tyrosine kinases (PTKs) function as key molecules in the signaling pathways in addition to their impact as a therapeutic target for the treatment of many human diseases, including cancer. PTKs are characterized by their ability to phosphorylate serine, threonine, or tyrosine residues and can thereby rapidly and reversibly alter the function of their protein substrates in the form of significant changes in protein confirmation and affinity for their interaction with protein partners to drive cellular functions under normal and pathological conditions. PTKs are classified into two groups: one of which represents tyrosine kinases, while the other one includes the members of the serine/threonine kinases. The group of tyrosine kinases is subdivided into subgroups: one of them includes the member of receptor tyrosine kinases (RTKs), while the other subgroup includes the member of non-receptor tyrosine kinases (NRTKs). Both these kinase groups function as an "on" or "off" switch in many cellular functions. NRTKs are enzymes which are overexpressed and activated in many cancer types and regulate variable cellular functions in response to extracellular signaling-dependent mechanisms. NRTK-mediated different cellular functions are regulated by kinase-dependent and kinase-independent mechanisms either in the cytoplasm or in the nucleus. Thus, targeting NRTKs is of great interest to improve the treatment strategy of different tumor types. This review deals with the structure and mechanistic role of NRTKs in tumor progression and resistance and their importance as therapeutic targets in tumor therapy.

FAK inhibitors in cancer, a patent review - an update on progress

INTRODUCTION

Focal adhesion kinase (FAK) is a cytoplasmic non-receptor tyrosine kinase over-expressed in various malignancies which is related to various cellular functions such as adhesion, metastasis and proliferation.

AREAS COVERED

There is growing evidence that FAK is a promising therapeutic target for designing inhibitors by regulating the downstream pathways of FAK. Some potential FAK inhibitors have entered clinical phase research.

EXPERT OPINION

FAK could be an effective target in medicinal chemistry research and there were a variety of FAKIs have been patented recently. Here, we updated an overview of design, synthesis and structure-activity relationship of chemotherapeutic FAK inhibitors (FAKIs) from 2017 until now based on our previous work. We hope our efforts can broaden the understanding of FAKIs and provide new ideas and insights for future cancer treatment from medicinal chemistry point of view.

P-NADs: PUX-based NAnobody degraders for ubiquitin-independent degradation of target proteins

Targeted protein degradation (TPD) allows cells to maintain a functional proteome and to rapidly adapt to changing conditions. Methods that repurpose TPD for the deactivation of specific proteins have demonstrated significant potential in therapeutic and research applications. Most of these methods are based on proteolysis targeting chimaeras (PROTACs) which link the protein target to an E3 ubiquitin ligase, resulting in the ubiquitin-based degradation of the target protein. In this study, we introduce a method for ubiquitin-independent TPD based on nanobody-conjugated plant ubiquitin regulatory X domain-containing (PUX) adaptor proteins. We show that the PUX-based NAnobody Degraders (P-NADs) can unfold a target protein through the Arabidopsis and human orthologues of the CDC48 unfoldase without the need for ubiquitination or initiating motifs. We demonstrate that P-NAD plasmids can be transfected into a human cell line, where the produced P-NADs use the endogenous CDC48 machinery for ubiquitin-independent TPD of a 143 kDa multidomain protein. Thus, P-NADs pave the road for ubiquitin-independent therapeutic TPD approaches. In addition, the modular P-NAD design combined with in vitro and cellular assays provide a versatile platform for elucidating functional aspects of CDC48-based TPD in plants and animals.

The roles of FHL2 as a mechanotransducer for cellular functions in the mechanical environment

The cell has multiple mechanisms for sensing and responding to dynamic changes in the mechanical environment. In the process, intracellular signaling is activated to modulate gene expression. Recent studies have shown that multifunctional signaling molecules that link intracellular force and gene expression are important for understanding cellular functions in the mechanical environment. This review discusses recent studies on one of the mechanotransducers, Four-and-a-half LIM domains 2 (FHL2), which localizes to focal adhesions (FAs), actin cytoskeleton, and nucleus. FHL2 localizes to FAs and the actin cytoskeleton in the cell on stiff substrate. In this situation, intracellular tension of F-actin by Myosin II is critical for FHL2 localization to FAs and actin stress fibers. In the case, a conserved phenylalanine in each LIM domain is responsible for its localization to F-actin. On the other hand, lower tension of F-actin in the cell on a soft substrate causes FHL2 to be released into the cytoplasm, resulting in its localization in the nucleus. At the molecular level, phosphorylation of specific tyrosine in FHL2 by FAK, non-receptor tyrosine kinase, is critical to nuclear localization. Finally, by binding to transcription factors, FHL2 modulates gene expression for cell proliferation as a transcriptional co-factor. Thus, FHL2 is involved in mechano-sensing and -transduction in the cell in a mechanical environment.

LINC00518: a key player in tumor progression and clinical outcomes

Long non-coding RNAs (lncRNAs), defined as RNA molecules exceeding 200 nucleotides in length, have been implicated in the regulation of various biological processes and the progression of tumors. Among them, LINC00518, a recently identified lncRNA encoded by a gene located on chromosome 6p24.3, consists of three exons and is predicted to positively regulate the expression of specific genes. LINC00518 has emerged as a key oncogenic lncRNA in multiple cancer types. It exerts its tumor-promoting effects by modulating the expression of several target genes, primarily through acting as a sponge for microRNAs (miRNAs). Additionally, LINC00518 influences critical signaling pathways, including the Wnt/β-catenin, JAK/STAT, and integrin β3/FAK pathways. Elevated levels of LINC00518 in tumor tissues are associated with increased tumor size, advanced clinical stage, metastasis, and poor survival prognosis. This review provides a comprehensive summary of the genetic characteristics, expression patterns, biological functions, and underlying mechanisms of LINC00518 in human diseases.

Focal adhesion kinase signaling - tumor vulnerabilities and clinical opportunities

Focal adhesion kinase (FAK; encoded by PTK2) was discovered over 30 years ago as a cytoplasmic protein tyrosine kinase that is localized to cell adhesion sites, where it is activated by integrin receptor binding to extracellular matrix proteins. FAK is ubiquitously expressed and functions as a signaling scaffold for a variety of proteins at adhesions and in the cell cytoplasm, and with transcription factors in the nucleus. FAK expression and intrinsic activity are essential for mouse development, with molecular connections to cell motility, cell survival and gene expression. Notably, elevated FAK tyrosine phosphorylation is common in tumors, including pancreatic and ovarian cancers, where it is associated with decreased survival. Small molecule and orally available FAK inhibitors show on-target inhibition in tumor and stromal cells with effects on chemotherapy resistance, stromal fibrosis and tumor microenvironment immune function. Herein, we discuss recent insights regarding mechanisms of FAK activation and signaling, its roles as a cytoplasmic and nuclear scaffold, and the tumor-intrinsic and -extrinsic effects of FAK inhibitors. We also discuss results from ongoing and advanced clinical trials targeting FAK in low- and high-grade serous ovarian cancers, where FAK acts as a master regulator of drug resistance. Although FAK is not known to be mutationally activated, preventing FAK activity has revealed multiple tumor vulnerabilities that support expanding clinical combinatorial targeting possibilities.

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

OBJECTIVE

Genomic 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 to the fusion of the adhesion protein CLDN18 and RHO regulator ARHGAP26. It remains unclear how these fusion constructs impact the activity of the RHO pathway and what is their broader impact on gastric cancer development. Herein, we developed a model to allow us to study the function of this fusion protein in the pathogenesis of DGC and to identify potential therapeutic targets for DGC tumours with these alterations.

DESIGN

We built a transgenic mouse model with LSL-CLDN18-ARHGAP26 fusion engineered into the Col1A1 locus where its expression can be induced by Cre recombinase. Using organoids generated from this model, we evaluated its oncogenic activity and the biochemical effects of the fusion protein on the RHOA pathway and its downstream cell biological effects in the pathogenesis of DGC.

RESULTS

We demonstrated that induction of CLDN18-ARHGAP26 expression in gastric organoids induced the formation of signet ring cells, characteristic features of DGC and was able to cooperatively transform gastric cells when combined with the loss of the tumour suppressor geneTrp53. CLDN18-ARHGAP26 promotes the activation of RHOA and downstream effector signalling. Molecularly, the fusion promotes activation of the focal adhesion kinase (FAK) and induction of the YAP pathway. A combination of FAK and YAP/TEAD inhibition can significantly block tumour growth.

CONCLUSION

These results indicate that the CLDN18-ARHGAP26 fusion is a gain-of-function DGC oncogene that leads to activation of RHOA and activation of FAK and YAP signalling. These results argue for further evaluation of emerging FAK and YAP-TEAD inhibitors for these deadly cancers.

The state of the art in secondary pharmacology and its impact on the safety of new medicines

Secondary pharmacology screening of investigational small-molecule drugs for potentially adverse off-target activities has become standard practice in pharmaceutical research and development, and regulatory agencies are increasingly requesting data on activity against targets with recognized adverse effect relationships. However, the screening strategies and target panels used by pharmaceutical companies may vary substantially. To help identify commonalities and differences, as well as to highlight opportunities for further optimization of secondary pharmacology assessment, we conducted a broad-ranging survey across 18 companies under the auspices of the DruSafe leadership group of the International Consortium for Innovation and Quality in Pharmaceutical Development. Based on our analysis of this survey and discussions and additional research within the group, we present here an overview of the current state of the art in secondary pharmacology screening. We discuss best practices, including additional safety-associated targets not covered by most current screening panels, and present approaches for interpreting and reporting off-target activities. We also provide an assessment of the safety impact of secondary pharmacology screening, and a perspective on opportunities and challenges in this rapidly developing field.

Adipocyte-specific FAK deletion promotes pancreatic β-cell apoptosis via adipose inflammatory response to exacerbate diabetes mellitus

BACKGROUND

White adipose tissue (WAT) has a key role in maintaining energy balance throughout the body, and their dysfunction take part in the regulation of diabetes mellitus. However, the internal regulatory mechanisms underlying are still unknown.

METHODS AND RESULTS

We generated adipocyte-specific FAK KO (FAK-AKO) mice and investigated their phenotype. The cascade of adipocyte, macrophage in adipocyte tissues, and pancreatic β-cells were proposed in FAK-AKO mice and validated by cell line studies using 3T3-L1, Raw264.7 and Min6. The FAK-AKO mice exhibited glucose intolerance, reduced adipose tissue mass and increased apoptosis, lipolysis and inflammatory response in adipose tissue. We further demonstrate that adipocyte FAK deletion increases β cell apoptosis and inflammatory infiltrates into islets, which is potentiated if mice were treated with STZ. In the STZ-induced diabetes model, FAK AKO mice exhibit less serum insulin content and pancreatic β cell area. Moreover, serum pro-inflammatory factors increased and insulin levels decreased after glucose stimulation in FAK AKO mice. In a parallel vitro experiment, knockdown or inhibition of FAK during differentiation also increased apoptosis, lipolysis and inflammatory in 3T3-L1 adipocytes, whereas the opposite was observed upon overexpression of FAK. Moreover, coculturing LPS-treated RAW264.7 macrophages with knockdown FAK of 3T3-L1 adipocytes increased macrophage pro-inflammatory response. Furthermore, conditioned medium from above stimulated Min6 cells apoptosis (with or without STZ), whereas the opposite was observed upon overexpression of FAK. Mechanistically, FAK protein interact with TRAF6 in adipocytes and knockdown or inhibition of FAK activated TRAF6/TAK1/NF-κB signaling, which exacerbates inflammation of adipocytes themselves.

CONCLUSION

Adipocyte FAK deletion promotes both adipocyte apoptosis and adipose tissue inflammation. Pro-inflammatory factors released by the FAK-null adipose tissue further trigger apoptosis in pancreatic islets induced by the administration of STZ, thereby exacerbating the diabetes mellitus. This study reveals a link between FAK-mediated adipose inflammation and diabetes mellitus, a mechanism that has not been previously recognized.

High throughput screening identifies dasatinib as synergistic with trametinib in low grade serous ovarian carcinoma

BACKGROUND

Low grade serous ovarian carcinoma (LGSOC) is a distinct histotype of ovarian cancer characterised high levels of intrinsic chemoresistance, highlighting the urgent need for new treatments. High throughput screening in clinically-informative cell-based models represents an attractive strategy for identifying candidate treatment options for prioritisation in clinical studies.

METHODS

We performed a high throughput drug screen of 1610 agents across a panel of 6 LGSOC cell lines (3 RAS/RAF-mutant, 3 RAS/RAF-wildtype) to identify novel candidate therapeutic approaches. Validation comprised dose-response analysis across 9 LGSOC models and 5 high grade serous comparator lines.

RESULTS

16 hits of 1610 screened compounds were prioritised for validation based on >50% reduction in nuclei counts in over half of screened cell lines at 1000 nM concentration. 11 compounds passed validation, and the four agents of greatest interest (dasatinib, tyrosine kinase inhibitor; disulfiram, aldehyde dehydrogenase inhibitor; carfilzomib, proteasome inhibitor; romidepsin, histone deacetylase inhibitor) underwent synergy profiling with the recently approved MEK inhibitor trametinib. Disulfiram demonstrated excellent selectivity for LGSOC versus high grade serous ovarian carcinoma comparator lines (P = 0.003 for IC50 comparison), while the tyrosine kinase inhibitor dasatinib demonstrated favourable synergy with trametinib across multiple LGSOC models (maximum zero interaction potency synergy score 46.9). The novel, highly selective Src family kinase (SFK) inhibitor NXP900 demonstrated a similar trametinib synergy profile to dasatinib, suggesting that SFK inhibition is the likely driver of synergy.

CONCLUSION

Dasatinib and other SFK inhibitors represent novel candidate treatments for LGSOC and demonstrate synergy with trametinib. Disulfiram represents an additional treatment strategy worthy of investigation.

Shenqi Yizhi prescription prevents AβO-induced memory impairment in mice by regulating the contractility of brain pericytes

BACKGROUND

Cerebral microcirculation disturbance manifested by decrease of cerebral blood flow (CBF) is one of early features of Alzheimer's disease (AD). Shenqi Yizhi prescription (SQYZ) is widely used in the treatment of AD. However, the effect of SQYZ on the early feature of AD is not clarified.

PURPOSE

To explore the effect and mechanism of SQYZ on AD-like behavior from the perspective of early pathological features of AD.

METHODS

The fingerprint of SQYZ was established by ultra-high-performance liquid chromatograph. The improvement effect of SQYZ on Aβ1-42 Oligomer (AβO)-induced AD-like behavior of mice was evaluated by behavioral test. The changes of CBF were detected by laser doppler meter and laser speckle imaging. The pathological changes of the hippocampus were observed by HE staining and transmission electron microscope. The expressions of intercellular communication molecules were detected by western blotting or immunofluorescence staining. The content of platelet-derived growth factor-BB (PDGF-BB) was detected by ELISA. Finally, the core components of SQYZ were docked with platelet-derived growth factor receptor beta (PDGFRβ) using AutoDock Vina software.

RESULTS

The similarity of the components in SQYZ extracted from different batches of medicinal materials was higher than 0.9. SQYZ administration could improve AβO-induced memory impairment and CBF reduction. Compared with the sham group, the number of neurons in the hippocampi of AβO group was significantly reduced, and the microvessels were shrunken and deformed. By contrary, SQYZ administration mitigated those pathological changes. Compared with the sham mice, the expressions of CD31, N-cadherin, PDGFRβ, glial fibrillary acidic protein, phosphorylation of focal adhesion kinase, integrin β1, and integrin α5 in the hippocampi of AβO mice were significantly increased. However, SQYZ administration significantly reduced AβO-induced expression of those proteins. Interestingly, the effect of PDGFRβ inhibitor, sunitinib demonstrated a consistent modulating effect as SQYZ. Finally, the brain-entering components of SQYZ, including ginsenoside Rg5, coptisine, cryptotanshinone, dihydrotanshinone IIA, stigmasterol, and tanshinone IIA had high binding force with PDGFRβ, implicating PDGFRβ as a potential target for SQYZ.

CONCLUSIONS

Our data indicate that SQYZ improves CBF in AβO-triggered AD-like mice through inhibiting brain pericyte contractility, indicating the treatment potential of SQYZ for AD at the early stage.

Analysis of Expression of the ANG1, CaSR and FAK Proteins in Uterine Fibroids

Understanding the molecular factors involved in the development of uterine myomas may result in the use of pharmacological drugs instead of aggressive surgical treatment. ANG1, CaSR, and FAK were examined in myoma and peripheral tissue samples taken from women after myoma surgery and in normal uterine muscle tissue samples taken from the control group. Tests were performed using tissue microarray immunohistochemistry. No statistically significant differences in ANG1 expression between the tissue of the myoma, the periphery, and the normal uterine muscle tissue of the control group were recorded. The CaSR value was reduced in the myoma and peripheral tissue and normal in the group of women without myomas. FAK expression was also lower in the myoma and periphery compared to the healthy uterine myometrium. Calcium supplementation could have an effect on stopping the growth of myomas.

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.

Monocytic Differentiation in Acute Myeloid Leukemia Cells: Diagnostic Criteria, Biological Heterogeneity, Mitochondrial Metabolism, Resistance to and Induction by Targeted Therapies

We review the importance of monocytic differentiation and differentiation induction in non-APL (acute promyelocytic leukemia) variants of acute myeloid leukemia (AML), a malignancy characterized by proliferation of immature myeloid cells. Even though the cellular differentiation block is a fundamental characteristic, the AML cells can show limited signs of differentiation. According to the French-American-British (FAB-M4/M5 subset) and the World Health Organization (WHO) 2016 classifications, monocytic differentiation is characterized by morphological signs and the expression of specific molecular markers involved in cellular communication and adhesion. Furthermore, monocytic FAB-M4/M5 patients are heterogeneous with regards to cytogenetic and molecular genetic abnormalities, and monocytic differentiation does not have any major prognostic impact for these patients when receiving conventional intensive cytotoxic therapy. In contrast, FAB-M4/M5 patients have decreased susceptibility to the Bcl-2 inhibitor venetoclax, and this seems to be due to common molecular characteristics involving mitochondrial regulation of the cellular metabolism and survival, including decreased dependency on Bcl-2 compared to other AML patients. Thus, the susceptibility to Bcl-2 inhibition does not only depend on general resistance/susceptibility mechanisms known from conventional AML therapy but also specific mechanisms involving the molecular target itself or the molecular context of the target. AML cell differentiation status is also associated with susceptibility to other targeted therapies (e.g., CDK2/4/6 and bromodomain inhibition), and differentiation induction seems to be a part of the antileukemic effect for several targeted anti-AML therapies. Differentiation-associated molecular mechanisms may thus become important in the future implementation of targeted therapies in human AML.

Targeting focal adhesion kinase (FAK) for cancer therapy: FAK inhibitors, FAK-based dual-target inhibitors and PROTAC degraders

Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, plays an essential role in regulating cell proliferation, migration and invasion through both kinase-dependent enzymatic function and kinase-independent scaffolding function. The overexpression and activation of FAK is commonly observed in various cancers and some drug-resistant settings. Therefore, targeted disruption of FAK has been identified as an attractive strategy for cancer treatment. To date, numerous structurally diverse inhibitors targeting distinct domains of FAK have been developed, encompassing kinase domain inhibitors, FERM domain inhibitors, and FAT domain inhibitors, with several FAK inhibitors advanced to clinical trials. Moreover, given the critical role of FAK scaffolding function in signal transduction, FAK-targeted PROTACs have also been developed. Although no current FAK-targeted therapeutics have been approved for the market, the combination of FAK inhibitors with other anticancer drugs has shown considerable promise in the clinic. This review provides an overview of current drug discovery strategies targeting FAK, including the development of FAK inhibitors, FAK-based dual-target inhibitors and proteolysis-targeting chimeras (PROTACs) in both literature and patent applications. Accordingly, their design and optimization process, mechanisms of action and biological activities are discussed to offer insights into future directions of FAK-targeting drug discovery in cancer therapy.

Prospects of focal adhesion kinase inhibitors as a cancer therapy in preclinical and early phase study

INTRODUCTION

FAK, a nonreceptor cytoplasmic tyrosine kinase, plays a crucial role in tumor metastasis, drug resistance, tumor stem cell maintenance, and regulation of the tumor microenvironment. FAK has emerged as a promising target for tumor therapy based on both preclinical and clinical data.

AREAS COVERED

This paper aims to summarize the molecular mechanisms underlying FAK's involvement in tumorigenesis and progression. Encouraging results have emerged from ongoing clinical trials of FAK inhibitors. Additionally, we present an overview of clinical trials for FAK inhibitors, examining their potential as promising treatments. The pertinent studies gathered from databases including PubMed, ClinicalTrials.gov.

EXPERT OPINION

Since the first finding in 1990s, targeting FAK has became the focus of interests in many pharmaceutical companies. Through 30 years' discovery, the industry and academy gradually realized the features of FAK target which may not be a driver gene but a solid defense system for the cancer initiation and development. Currently, the ongoing clinical regimens involving FAK inhibition are all the combination strategies in which FAK inhibitors can further strengthen the cancer cell killing effects of other testing agents. The emerging positive signal in clinical trials foresee targeting FAK as class will be an effective mean to fight against cancers.

Self-assembly of peptides in living cells for disease theranostics

The past few decades have witnessed substantial progress in biomedical materials for addressing health concerns and improving disease therapeutic and diagnostic efficacy. Conventional biomedical materials are typically created through an ex vivo approach and are usually utilized under physiological environments via transfer from preparative media. This transfer potentially gives rise to challenges for the efficient preservation of the bioactivity and implementation of theranostic goals on site. To overcome these issues, the in situ synthesis of biomedical materials on site has attracted great attention in the past few years. Peptides, which exhibit remarkable biocompability and reliable noncovalent interactions, can be tailored via tunable assembly to precisely create biomedical materials. In this review, we summarize the progress in the self-assembly of peptides in living cells for disease diagnosis and therapy. After a brief introduction to the basic design principles of peptide assembly systems in living cells, the applications of peptide assemblies for bioimaging and disease treatment are highlighted. The challenges in the field of peptide self-assembly in living cells and the prospects for novel peptide assembly systems towards next-generation biomaterials are also discussed, which will hopefully help elucidate the great potential of peptide assembly in living cells for future healthcare applications.

Focal adhesion kinase-YAP signaling axis drives drug-tolerant persister cells and residual disease in lung cancer

Targeted therapy is effective in many tumor types including lung cancer, the leading cause of cancer mortality. Paradigm defining examples are targeted therapies directed against non-small cell lung cancer (NSCLC) subtypes with oncogenic alterations in EGFR, ALK and KRAS. The success of targeted therapy is limited by drug-tolerant persister cells (DTPs) which withstand and adapt to treatment and comprise the residual disease state that is typical during treatment with clinical targeted therapies. Here, we integrate studies in patient-derived and immunocompetent lung cancer models and clinical specimens obtained from patients on targeted therapy to uncover a focal adhesion kinase (FAK)-YAP signaling axis that promotes residual disease during oncogenic EGFR-, ALK-, and KRAS-targeted therapies. FAK-YAP signaling inhibition combined with the primary targeted therapy suppressed residual drug-tolerant cells and enhanced tumor responses. This study unveils a FAK-YAP signaling module that promotes residual disease in lung cancer and mechanism-based therapeutic strategies to improve tumor response.

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.