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

Therapeutic potential of GNRHR analogs and SRC/FAK inhibitors to counteract tumor growth and metastasis in breast cancer

Breast cancer (BC) is the leading cause of cancer death in women, with hormone-dependent BC accounting for about 80 % of cases, primarily affecting postmenopausal women with gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) elevated. Treatments targeting the gonadotropin-releasing hormone receptor (GnRHR), such as the agonist leuprorelin (LEU) and antagonist degarelix (DEGA), are used for hormone-dependent tumors. While the functional role of gonadotropin receptors in extragonadal tissues remains uncertain, recent studies suggest LH contributes to tumor development and progression. Tumor progression involves reorganization in the actin cytoskeleton, induction of adhesion, and cell migration, driven by proteins such as Src and the focal adhesion kinase (FAK), which are related to invasive behaviors. The overexpression of both protein kinases generates an invasive and metastatic phenotype, then inhibitors targeting Src (PP2) and FAK (FAKi) have been developed to counteract this effect. This study combined GnRH analogs with Src and FAK inhibitors to target BC progression. We found that LH treatment influenced gene expression linked to tumor development. Examining the GnRHR-LEU and GnRHR-DEGA complexes revealed structural differences affecting ligand binding. In an orthotopic tumor model, DEGA reduced tumor growth, while LEU had the opposite effect. Combining DEGA with PP2 or FAKi enhanced tumor inhibition, improving mice survival. These findings provide valuable insights into the essential regulatory role of gonadotropins in genes involved in tumorigenic processes, highlighting the potential of GnRHR antagonists combined with Src or FAK inhibitors as a promising strategy to develop new drugs that interfere with the ability of breast tumor progression.

ALK-based dual inhibitors: Focus on recent development for non-small cell lung cancer therapy

As a prevalent oncogenic driver gene in non-small cell lung cancer (NSCLC), ALK represents a crucial and efficacious therapeutic target. To date, seven ALK inhibitors have been approved for ALK fusion-positive NSCLC, with several others undergoing clinical trials. These therapies demonstrate significant efficacy in ALK fusion-positive NSCLC patients. However, acquired resistance mechanisms, including ALK kinase domain mutations, ALK gene amplification, and bypass pathway activation, significantly compromise the efficacy of targeted therapy in ALK fusion-positive NSCLC. Therefore, the discovery of novel ALK inhibitors and the development of related treatment strategies remain critical. Compared to the combination therapy strategy based on ALK inhibitors, dual-target inhibitors (targeting two distinct pathways within a single molecule) may reduce systemic toxicity and mitigate resistance mechanisms in cancer treatment. Notably, recent years have witnessed remarkable progress in dual-target ALK inhibitor development for NSCLC. Consequently, this review aims to summarize the advancements achieved through dual ALK-based inhibitors in NSCLC therapy, analyze their rational design and structure-activity relationships, and provide perspectives for overcoming resistance through next-generation inhibitors and innovative therapeutic approaches.

Thienopyrimidine: A promising scaffold in the development of kinase inhibitors with anticancer activities

Protein kinases represent a highly promising drug target, with over 80 drugs that target about two dozen different protein kinases have been approved by the US FDA, particularly in cancer treatment. Over the past decades, the unique structural characteristics of the thienopyrimidine ring system provide an adaptive platform for designing potent anticancer agents, especially various kinase inhibitors, which has attracted widespread attention. Some of these thienopyrimidines as anticancer kinase inhibitors have already been marketed or are currently undergoing clinical/preclinical studies for the treatment of cancers, such as Olmutinib, Pictilisib, SNS-314, PF-03758309, and Fimepinostat, highlighting the substantial advantages of the thienopyrimidine scaffold in the discovery of anticancer agents. This article reviews the discovery, activity, and structure-activity relationships of antitumor kinase inhibitors based on the thienopyrimidine scaffold, and partially discusses the binding modes between thienopyrimidine derivatives and their kinase targets. By elucidating the application of thienopyrimidine derivatives as anticancer kinase inhibitors, this review aims to provide new perspectives for the development of more effective and novel kinase inhibitors.

Unravelling key signaling pathways for the therapeutic targeting of non-small cell lung cancer

Lung cancer (LC) remains the foremost cause of cancer-related mortality across the globe. Non-small cell lung cancer (NSCLC) is a type of LC that exhibits significant heterogeneity at histological and molecular levels. Genetic alterations in upstream signaling molecules activate cascades affecting apoptosis, proliferation, and differentiation. Disruption of these signaling pathways leads to the proliferation of cancer-promoting cells, progression of cancer, and resistance to its treatment. Recent insights into the function of signaling pathways and their fundamental mechanisms in the onset of various diseases could pave the way for new therapeutic approaches. Recently, numerous drug molecules have been created that target these cell signaling pathways and could be used alongside other standard therapies to achieve synergistic effects in mitigating the pathophysiology of NSCLC. Additionally, many researchers have identified several predictive biomarkers, and alterations in transcription factors and related pathways are employed to create new therapeutic strategies for NSCLC. Findings suggest using specific inhibitors to target cellular signaling pathways in tumor progression to treat NSCLC. This review investigates the role of signaling pathways in NSCLC development and explores novel therapeutic strategies to enhance clinical treatment options for NSCLC.

Focal adhesion in the tumour metastasis: from molecular mechanisms to therapeutic targets

The tumour microenvironment is the "hotbed" of tumour cells, providing abundant extracellular support for growth and metastasis. However, the tumour microenvironment is not static and is constantly remodelled by a variety of cellular components, including tumour cells, through mechanical, biological and chemical means to promote metastasis. Focal adhesion plays an important role in cell-extracellular matrix adhesion. An in-depth exploration of the role of focal adhesion in tumour metastasis, especially their contribution at the biomechanical level, is an important direction of current research. In this review, we first summarize the assembly of focal adhesions and explore their kinetics in tumour cells. Then, we describe in detail the role of focal adhesion in various stages of tumour metastasis, especially its key functions in cell migration, invasion, and matrix remodelling. Finally, we describe the anti-tumour strategies targeting focal adhesion and the current progress in the development of some inhibitors against focal adhesion proteins. In this paper, we summarize for the first time that focal adhesion play a positive feedback role in pro-tumour metastatic matrix remodelling by summarizing the five processes of focal adhesion assembly in a multidimensional way. It is beneficial for researchers to have a deeper understanding of the role of focal adhesion in the biological behaviour of tumour metastasis and the potential of focal adhesion as a therapeutic target, providing new ideas for the prevention and treatment of metastases.

Focal Adhesion Regulation as a Strategy against Kidney Fibrosis

Chronic kidney fibrosis poses a significant global health challenge with effective therapeutic strategies remaining elusive. While cell-extracellular matrix (ECM) interactions are known to drive fibrosis progression, the specific role of focal adhesions (FAs) in kidney fibrosis is not fully understood. In this study, we investigated the role of FAs in kidney tubular epithelial cell fibrosis by employing precise nanogold patterning to modulate integrin distribution. We demonstrate that increasing ligand spacing disrupts integrin clustering, thereby inhibiting FA formation and attenuating fibrosis. Importantly, enhanced FA activity is associated with kidney fibrosis in both human disease specimens and murine models. Mechanistically, FAs regulate fibrosis through mechanotransduction pathways, and our in vivo experiments show that suppressing mechanotransduction significantly mitigates kidney fibrosis in mice. These findings highlight the potential of targeting FAs as a therapeutic strategy, offering new insights into clinical intervention in kidney fibrosis.

Combined inhibition of focal adhesion kinase and RAF/MEK elicits synergistic inhibition of melanoma growth and reduces metastases

This study addresses the urgent need for effective therapies for patients with brain metastases from cutaneous melanoma, a major cause of treatment failure despite recent therapeutic advances. Utilizing mouse models that mimic human melanoma brain metastases, this study investigates the necessity of focal adhesion kinase (FAK) in the development of distant metastases and its potential as a therapeutic target. Pharmacological inhibition of FAK demonstrates significant efficacy in reducing the development of brain metastases in preclinical mouse models. Importantly, the study provides insight into the crosstalk between FAK and mitogen-activated protein kinase (MAPK) pathway signaling and highlights the synergistic effects of combined inhibition of FAK, rapidly accelerated fibrosarcoma (RAF), and mitogen-activated protein kinase kinase (MEK) in cutaneous melanoma. These findings provide the rationale for clinical evaluation of the efficacy of the FAK inhibitor defactinib and the RAF/MEK inhibitor avutometinib in patients with brain metastases from cutaneous melanoma.

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.

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.

Widely-targeted in silico and in vitro evaluation of veratrum alkaloid analogs as FAK inhibitors and dual targeting of FAK and Hh/SMO pathways for cancer therapy: A critical analysis

Focal Adhesive Kinase (FAK), a key player in aggressive cancers, mediates signals crucial for progression, invasion, and metastasis. Despite advances in targeted therapies, drug resistance is still a challenge, and survival rates remain low, particularly for late-stage patients, emphasizing the need for innovative cancer therapeutics. Cyclopamine, a veratrum alkaloid, has shown promising anti-tumor properties, but the search for more potent analogs with enhanced affinity for the biological target continues. This study employs a hybrid virtual screening approach combining pharmacophore model-based virtual screening (PB-VS) and docking-based virtual screening (DB-VS) to identify potential inhibitors of the FAK catalytic domain. PB-VS on the PubChem database yielded a set of hits, which were then docked with the FAK catalytic domain in two stages (1st and 2nd DB-VS). Hits were ranked based on docking scores and interactions with the active site. The top three compounds underwent molecular dynamics simulations, alongside two control compounds (SMO inhibitor(s) and FAK inhibitor(s)), to assess stability through RMSD, RMSF, Rg, and SASA analyses. ADMET properties were evaluated, and compounds were filtered based on drug-likeness criteria. Molecular dynamics simulations demonstrated the stability of compounds when complexed with the FAK catalytic domain. Compounds 16 (-25 kcal/mol), 87 (-27.47 kcal/mol), and 88 (-18.94 kcal/mol) exhibited comparable docking scores, interaction profiles, stability, and binding energies, indicating their potential as lead candidates. However, further validation and optimization through quantitative structure-activity relationship (QSAR) studies are essential to refine their efficacy and therapeutic potential. The in vitro cell-based assay demonstrated that compound 101PF, a FAK inhibitor, significantly inhibited the proliferation and migration of A549 cells. However, the results regarding the combined effects of FAK and SMO inhibitors were inconclusive, highlighting the need for further investigation. This study contributes to developing more effective anti-cancer drugs by improving the understanding of potential cyclopamine-based veratrum alkaloid analogs with enhanced interactions with the FAK catalytic domain.

A novel selective FAK inhibitor E2 inhibits ovarian cancer metastasis and growth by inducing cytotoxic autophagy

Ovarian cancer (OC) is the deadliest form of the gynecologic malignancies and effective therapeutic drugs are urgently needed. Focal adhesion kinase (FAK) is overexpressed in various solid tumors, and could serve as a potential biomarker of ovarian cancer. However, there are no launched drugs targeting FAK. Hence, the development of the novel FAK inhibitors is an emerging approach for the treatment of ovarian cancer. In this work, we characterized a selective FAK inhibitor E2, with a high inhibitory potency toward FAK. Moreover, E2 had cytotoxic, anti-invasion and anti-migration activity on ovarian cancer cells. Mechanistically, after treatment with E2, FAK downstream signaling cascades (e.g., Src and AKT) were suppressed, thus resulting in the ovarian cancer cell arrest at G0/G1 phase and the induction of cytotoxic autophagy. In addition, E2 attenuated the tumor growth of PA-1 and ES-2 ovarian cancer subcutaneous xenografts, as well as suppressed peritoneal metastasis of OVCAR3-luc. Furthermore, E2 exhibited favorable pharmacokinetic properties. Altogether, these findings demonstrate that E2 is a selective FAK inhibitor with potent anti-ovarian cancer activities both in vivo and in vitro, offering new possibilities for OC treatment strategies.

ITGB4 Serves as an Identification and Prognosis Marker Associated with Immune Infiltration in Small Cell Lung Carcinoma

Integrin beta 4 (ITGB4) is a vital factor for numerous cancers. However, no reports regarding ITGB4 in small cell lung carcinoma (SCLC) have been found in the existing literature. This study systematically investigated the expression and clinical value of ITGB4 in SCLC using multi-center and large-sample (n = 963) data. The ITGB4 expression levels between SCLC and control tissues were compared using standardized mean difference and Wilcoxon rank-sum test. The clinical significance of the gene in SCLC was observed using Cox regression and Kaplan-Meier curves. ITGB4 is overexpressed in multiple cancers and represents significant value in distinguishing among cancer samples (AUC = 0.91) and predicting the prognoses (p < 0.05) of patients with different cancers. In contrast, decreased ITGB4 mRNA expression was determined in SCLC (SMD < 0), and this finding was further confirmed at protein levels using in-house specimens (p < 0.05). This decrease in expression may be attributed to the regulatory role of estrogen receptor 1. ITGB4 may participate in the progression of SCLC by affecting several signaling pathways (e.g., tumor necrosis factor signaling pathway) and a series of immune cells (e.g., dendritic cells) (p < 0.05). The gene may serve as a potential marker for predicting the disease status (AUC = 0.97) and prognoses (p < 0.05) of patients with SCLC. Collectively, ITGB4 was identified as an identification and prognosis marker associated with immune infiltration in SCLC.

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.

Preclinical evaluation of avutometinib and defactinib in high-grade endometrioid endometrial cancer

BACKGROUND

High-grade endometrial cancers (EAC) are aggressive tumors with a high risk of progression after treatment. As EAC may harbor mutations in the RAS/MAPK pathways, we evaluated the preclinical in vitro and in vivo efficacy of avutometinib, a RAF/MEK clamp, in combination with the focal adhesion kinase (FAK) inhibitors defactinib or VS-4718, against multiple primary EAC cell lines and xenografts.

METHODS

Whole-exome sequencing (WES) was used to evaluate the genetic landscape of five primary EAC cell lines. The in vitro activity of avutometinib and defactinib as single agents and in combination was evaluated using cell viability, cell cycle, and cytotoxicity assays. Mechanistic studies were performed using Western blot assays while in vivo experiments were completed in UTE10 engrafted mice treated with either vehicle, avutometinib, VS-4718, or their combination through oral gavage.

RESULTS

WES results demonstrated multiple EAC cell lines to harbor genetic derangements in the RAS/MAPK pathway including KRAS/PTEN/PIK3CA/BRAF/ARID1A, potentially sensitizing to FAK and RAF/MEK inhibition. Five out of five of the EAC cell lines demonstrated in vitro sensitivity to FAK and/or RAF/MEK inhibition. By Western blot assays, exposure of EAC cell lines to defactinib, avutometinib, and their combination demonstrated decreased phosphorylated FAK (p-FAK) as well as decreased p-MEK and p-ERK. In vivo the combination of avutometinib/VS-4718 demonstrated superior tumor growth inhibition compared to single-agent treatment and controls starting at Day 9 (p < 0.02 and p < 0.04) in UTE10 xenografts.

CONCLUSIONS

Avutometinib, defactinib, and to a larger extent their combinations, demonstrated promising in vitro and in vivo activity against EAC cell lines and xenografts. These preclinical data support the potential clinical evaluation of this combination in high-grade EAC patients.

Mechanism and application of feedback loops formed by mechanotransduction and histone modifications

Mechanical stimulation is the key physical factor in cell environment. Mechanotransduction acts as a fundamental regulator of cell behavior, regulating cell proliferation, differentiation, apoptosis, and exhibiting specific signature alterations during the pathological process. As research continues, the role of epigenetic science in mechanotransduction is attracting attention. However, the molecular mechanism of the synergistic effect between mechanotransduction and epigenetics in physiological and pathological processes has not been clarified. We focus on how histone modifications, as important components of epigenetics, are coordinated with multiple signaling pathways to control cell fate and disease progression. Specifically, we propose that histone modifications can form regulatory feedback loops with signaling pathways, that is, histone modifications can not only serve as downstream regulators of signaling pathways for target gene transcription but also provide feedback to regulate signaling pathways. Mechanotransduction and epigenetic changes could be potential markers and therapeutic targets in clinical practice.

Survival mechanisms of circulating tumor cells and their implications for cancer treatment

Metastasis remains the principal trigger for relapse and mortality across diverse cancer types. Circulating tumor cells (CTCs), which originate from the primary tumor or its metastatic sites, traverse the vascular system, serving as precursors in cancer recurrence and metastasis. Nevertheless, before CTCs can establish themselves in the distant parenchyma, they must overcome significant challenges present within the circulatory system, including hydrodynamic shear stress (HSS), oxidative damage, anoikis, and immune surveillance. Recently, there has been a growing body of compelling evidence suggesting that a specific subset of CTCs can persist within the bloodstream, but the precise mechanisms of their survival remain largely elusive. This review aims to present an outline of the survival challenges encountered by CTCs and to summarize the recent advancements in understanding the underlying survival mechanisms, suggesting their implications for cancer treatment.

Preclinical in vitro and in vivo activity of the RAF/MEK clamp avutometinib in combination with FAK inhibition in uterine carcinosarcomas

OBJECTIVES

Uterine carcinosarcomas (UCS) are rare, biologically aggressive tumors. Since UCS may harbor mutations in RAS/MAPK pathway genes we evaluated the preclinical in vitro and in vivo efficacy of the RAF/MEK clamp avutometinib in combination with the focal adhesion kinase (FAK) inhibitors defactinib or VS-4718 against multiple primary UCS cell lines and xenografts.

METHODS

Whole-exome-sequencing (WES) was used to evaluate the genetic landscape of 5 primary UCS cell lines. The in vitro activity of avutometinib ± FAK inhibitor was evaluated using cell viability and cell cycle assays against primary UCS cell lines. Mechanistic studies were performed using western blot assays while in vivo experiments were completed in UCS tumor bearing mice treated with avutometinib ± FAK inhibitor by oral gavage.

RESULTS

WES results demonstrated multiple UCS cell lines harbor genetic alterations including KRAS, PTK2, BRAF, MAP2K, and MAP2K1, potentially sensitizing to FAK and RAF/MEK inhibition. Four out of five of the UCS cell lines demonstrated in vitro sensitivity to FAK and/or RAF/MEK inhibition when used alone or in combination. By western blot assays, exposure of UCS cell lines to the combination of defactinib/avutometinib demonstrated decreased phosphorylated (p)-FAK as well as decreased p-ERK. In vivo, the combination of avutometinib/VS-4718 demonstrated superior tumor growth inhibition and longer survival compared to single agent treatment and controls starting at day 10 (p < 0.002) in UCS xenografts.

CONCLUSION

The combination of avutometinib and defactinib demonstrates promising in vitro and in vivo anti-tumor activity against primary UCS cell lines and xenografts.

A reanalysis and integration of transcriptomics and proteomics datasets unveil novel drug targets for Mekong schistosomiasis

Schistosomiasis, caused by Schistosoma trematodes, is a significant global health concern, particularly affecting millions in Africa and Southeast Asia. Despite efforts to combat it, the rise of praziquantel (PZQ) resistance underscores the need for new treatment options. Protein kinases (PKs) are vital in cellular signaling and offer potential as drug targets. This study focused on focal adhesion kinase (FAK) as a candidate for anti-schistosomal therapy. Transcriptomic and proteomic analyses of adult S. mekongi worms identified FAK as a promising target due to its upregulation and essential role in cellular processes. Molecular docking simulations assessed the binding energy of FAK inhibitors to Schistosoma FAK versus human FAK. FAK inhibitor 14 and PF-03814735 exhibited strong binding to Schistosoma FAK with minimal binding for human FAK. In vitro assays confirmed significant anti-parasitic activity against S. mekongi, S. mansoni, and S. japonicum, comparable to PZQ, with low toxicity in human cells, indicating potential safety. These findings highlight FAK as a promising target for novel anti-schistosomal therapies. However, further research, including in vivo studies, is necessary to validate efficacy and safety before clinical use. This study offers a hopeful strategy to combat schistosomiasis and reduce its global impact.

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.

CD276 enhances sunitinib resistance in clear cell renal cell carcinoma by promoting DNA damage repair and activation of FAK-MAPK signaling pathway

OBJECTIVE

This study aimed to explore the effect of CD276 expression on the sunitinib sensitivity of clear cell renal cell carcinoma (ccRCC) cell and animal models and the potential mechanisms involved.

METHODS

CD276 expression levels of ccRCC and normal samples were analyzed via online databases and real-time quantitative PCR (RT-qPCR). CD276 was knocked down in ccRCC cell models (sunitinib-resistant 786-O/R cells and sunitinib-sensitive 786-O cells) using shRNA transfection, and the cells were exposed to a sunitinib (2 µM) environment. Cells proliferation was then analyzed using MTT assay and colony formation experiment. Alkaline comet assay, immunofluorescent staining, and western blot experiments were conducted to assess the DNA damage repair ability of the cells. Western blot was also used to observe the activation of FAK-MAPK pathway within the cells. Finally, a nude mouse xenograft model was established and the nude mice were orally administered sunitinib (40 mg/kg/d) to evaluate the in vivo effects of CD276 knockdown on the therapeutic efficacy of sunitinib against ccRCC.

RESULTS

CD276 was significantly upregulated in both ccRCC clinical tissue samples and cell models. In vitro experiments showed that knocking down CD276 reduced the survival rate, IC50 value, and colony-forming ability of ccRCC cells. Knocking down CD276 increased the comet tail moment (TM) values and γH2AX foci number, and reduced BRCA1 and RAD51 protein levels. Knocking down CD276 also decreased the levels of p-FAK, p-MEK, and p-ERK proteins.

CONCLUSION

Knocking down CD276 effectively improved the sensitivity of ccRCC cell and animal models to sunitinib treatment.

Preclinical efficacy of RAF/MEK clamp avutometinib in combination with FAK inhibition in low grade serous ovarian cancer

OBJECTIVES

Low-grade-serous-ovarian-carcinoma (LGSOC) is characterized by a high recurrence rate and limited therapeutic options. About one-third of LGSOC contains mutations in MAPK pathway genes such as KRAS/NRAS/BRAF. Avutometinib is a dual RAF/MEK inhibitor while defactinib and VS-4718 are focal-adhesion-kinase-inhibitors (FAKi). We determined the preclinical efficacy of avutometinib±VS-4718 in LGSOC patient-derived-tumor-xenografts (PDX).

METHODS

Whole-exome-sequencing (WES) was used to evaluate the genetic fingerprint of 3 patient-derived LGSOC (OVA(K)250, PERIT(M)17 and A(PE)148). OVA(K)250 tissue was successfully xenografted as PDX into female CB17/lcrHsd-Prkdc/SCID-mice. Animals were treated with either control, avutometinib, VS-4718, or avutometinib/ VS-4718 once daily five days on and two days off through oral gavage. Mechanistic studies were performed ex vivo using avutometinib±defactinib treated LGSOC tumor samples by western blot.

RESULTS

WES results demonstrated wild-type KRAS in all 3 LGSOC. OVA(K)250 PDX showed gain-of-function mutations (GOF) in PTK2 and PTK2B genes, and loss-of-heterozygosity in ADRB2, potentially sensitizing to FAK and RAF/MEK inhibition. The combination of avutometinib/ VS-4718 demonstrated strong tumor-growth inhibition compared to controls starting at day 9 (p < 0.002) in OVA(K)250PDX. By 60 days, mice treated with avutometinib alone and avutometinib/VS-4718 were still alive; compared to median survival of 20 days in control-treated mice and of 35 days in VS-4718-treated mice (p < 0.0001). By western-blot assays exposure of OVA(K)250 to avutometinib, FAKi defactinib and their combination demonstrated decreased phosphorylated FAK (p-FAK) as well as decreased p-ERK.

CONCLUSION

Avutometinib, and to a larger extent its combination with FAK inhibitor VS-4718, demonstrated promising in vivo activity against a KRAS wild-type LGSOC-PDX. These data support the ongoing registration-directed study (RAMP201/NCT04625270).

Annual review of PROTAC degraders as anticancer agents in 2022

Following nearly two decades of development, significant advancements have been achieved in PROTAC technology. As of the end of 2022, more than 20 drugs have entered clinical trials, with ARV-471 targeting estrogen receptor (ER) showing remarkable progress by entering phase III clinical studies. In 2022, significant progress has been made on multiple targets. The first reversible covalent degrader designed to target the KRASG12C mutant protein, based on cyclopropionamide, has been reported. Additionally, the activity HDCA1 degrader surpassed submicromolar levels during the same year. A novel FEM1B covalent ligand called EN106 was also discovered, expanding the range of available ligands. Furthermore, the first PROTAC drug targeting SOS1 was reported. Additionally, the first-in-class degraders that specifically target BRD4 isoforms (BRD4 L and BRD4 S) have recently been reported, providing a valuable tool for further investigating the biological functions of these isoforms. Lastly, a breakthrough was also achieved with the first degrader targeting both CDK9 and Cyclin T1. In this review, we aimed to update the PROTAC degraders as potential anticancer agents covering articles published in 2022. The design strategies, degradation effects, and anticancer activities were highlighted, which might provide an updated sight to develop novel PROTAC degraders with great potential as anticancer agents as well as favorable drug-like properties.

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.

Design, synthesis and biological evaluation of novel 2,4-diaminopyrimidine cinnamyl derivatives as inhibitors of FAK with potent anti-gastric cancer activities

In this study, twenty-one novel 2,4-diaminopyrimidine cinnamyl derivatives as inhibitors targeting FAK were designed and synthesized based on the structure of TAE-226, and the inhibitory effects of these compounds on both the FAK enzyme and three cancer cell lines (MGC-803, HCT-116, and KYSE30) were investigated. Among them, compound 12s displayed potent inhibitory potency on FAK (IC50 = 47 nM), and demonstrated more significant antiproliferative activities in MGC-803, HCT-116 and KYSE30 cells (IC50 values were 0.24, 0.45 and 0.44 μM, respectively) compared to TAE-226. Furthermore, compound 12s significantly inhibited FAK activation leading to the negative regulation of FAK-related signaling pathways such as AKT/mTOR and MAPK signaling pathways. Molecular docking study suggested that compound 12s could well occupy the ATP-binding pocket site of FAK similar to TAE-226. In addition, compound 12s also efficiently inhibited the proliferation, induced apoptosis and cellular senescence in MGC-803 cells. In conclusion, compound 12s emerges a potent FAK inhibitor that could exert potent inhibitory activity against gastric cancer cells.

Effect of activating cancer-associated fibroblasts biomarker TNC on immune cell infiltration and prognosis in breast cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs) are the most important components of the tumor microenvironment (TME). CAFs are heterogeneous and involved in tumor tumorigenesis and drug resistance, contributing to TME remodeling and predicting clinical outcomes as prognostic factors. However, the effect of CAFs the TME and the prognosis of patients with breast cancer (BC) is not fully understood. This study investigated the correlation between CAFs-activating biomarkers immune cell infiltration and survival in patients with breast cancer.

METHODS

RNA sequencing data and survival information for patients with breast cancer were downloaded from The Cancer Genome Atlas (TCGA) using R software. We then analyzed the correlation between CAFs-expressing biomarkers and immune cells using the clusterProfiler package, and evaluated the prognostic role of appealing genes using the Survminer package. Immunohistochemical (IHC) staining was used to determine the expression levels of TNC in 160 breast cancer samples pathologically diagnosed as invasive ductal carcinoma that were not otherwise specified (IDC-NOS).

RESULTS

Data analysis showed that CAFs-expressing genes was higher than in normal tissues (p < 0.05). Pathway enrichment revealed that the overexpression of CAFs-related genes was mainly enriched in the focal adhesion and phosphoinositol-3 kinase-serine/threonine kinase (PI3K-AKT) signaling pathways. Immune infiltration analysis suggested that high expression of CAFs-related genes was significantly positively correlated with the infiltration of naive B cells and resting dendritic cells and inversely correlated with macrophages cell infiltration. In addition, high TNC expression in tumor cells was associated with the most adverse clinicopathological features and reduced metastasis-free survival (MFS) (hazard ratio (HR) 0.574, 95% confidence interval (CI) 0.404-0.815, p = 0.035).

CONCLUSIONS

This study found that CAFs may participate in immunosuppression and regulate tumor cell proliferation and invasion. High TNC expression is associated with several adverse clinicopathological features, and high TNC expression in tumor cells has been identified as an independent prognostic factor for IDC-NOS.

A review of progress in o-aminobenzamide-based HDAC inhibitors with dual targeting capabilities for cancer therapy

Histone deacetylases, as a new class of anticancer targets, could maintain homeostasis by catalyzing histone deacetylation and play important roles in regulating the expression of target genes. Due to the fact that simultaneous intervention with dual tumor related targets could improve treatment effects, researches on innovative design of dual-target drugs are underway. HDAC is known as a "sensitizer" for the synergistic effects with other anticancer-target drugs because of its flexible structure design. The synergistic effects of HDAC inhibitor and other target inhibitors usually show enhanced inhibitory effects on tumor cells, and also provide new strategies to overcome multidrug resistance. Many research groups have reported that simultaneously inhibiting HDAC and other targets, such as tubulin, EGFR, could enhance the therapeutic effects. The o-aminobenzamide group is often used as a ZBG group in the design of HDAC inhibitors with potent antitumor effects. Given the prolonged inhibitory effects and reduced toxic side effects of HDAC inhibitors using o-aminobenzamide as the ZBG group, the o-aminobenzamide group is expected to become a more promising alternative to hydroxamic acid. In fact, o-aminobenzamide-based dual inhibitors of HDAC with different chemical structures have been extensively prepared and reported with synergistic and enhanced anti-tumor effects. In this work, we first time reviewed the rational design, molecular docking, inhibitory activities and potential application of o-aminobenzamide-based HDAC inhibitors with dual targeting capabilities in cancer therapy, which might provide a reference for developing new and more effective anticancer drugs.

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

BACKGROUND

Emerging evidence suggests the critical roles of N6-methyladenosine (m6A) RNA modification in tumorigenesis and tumor progression. However, the role of m6A in non-small cell lung cancer (NSCLC) is still unclear. This study aimed to explore the role of the m6A demethylase fat mass and obesity-associated protein (FTO) in the tumor metastasis of NSCLC.

METHODS

A human m6A epitranscriptomic microarray analysis was used to identify downstream targets of FTO. Quantitative real-time PCR (qRT‒PCR) and western blotting were employed to evaluate the expression levels of FTO and FAP in NSCLC cell lines and tissues. Gain-of-function and loss-of-function assays were conducted in vivo and in vitro to assess the effects of FTO and FAP on NSCLC metastasis. M6A-RNA immunoprecipitation (MeRIP), RNA immunoprecipitation (RIP), luciferase reporter assays, and RNA stability assays were used to explore the mechanism of FTO action. Co-immunoprecipitation (co-IP) assays were used to determine the mechanism of FAP in NSCLC metastasis.

RESULTS

FTO was upregulated and predicted poor prognosis in patients with NSCLC. FTO promoted cell migration and invasion in NSCLC, and the FAK inhibitor defactinib (VS6063) suppressed NSCLC metastasis induced by overexpression of FTO. Mechanistically, FTO facilitated NSCLC metastasis by modifying the m6A level of FAP in a YTHDF2-dependent manner. Moreover, FTO-mediated metastasis formation depended on the interactions between FAP and integrin family members, which further activated the FAK signaling.

CONCLUSION

Our current findings provided valuable insights into the role of FTO-mediated m6A demethylation modification in NSCLC metastasis. FTO was identified as a contributor to NSCLC metastasis through the activation of the FAP/integrin/FAK signaling, which may be a potential therapeutic target for NSCLC. Video Abstract.

Design, synthesis and biological evaluation of 4-arylamino-pyrimidine derivatives as focal adhesion kinase inhibitors

A novel series of 4-arylamino-pyrimidine derivatives were designed and synthesized as focal adhesion kinase (FAK) inhibitors under the strategy of structure-based drug design. Most compounds performed excellent anti-proliferative activity against U87-MG cells. Especially, compounds 8d and 9b revealed the highest activity with IC50 values of 0.975 μM and 1.033 μM, which was much potent than the positive control TAE-226 (IC50 = 2.659 μM). On the other hand, the total 27 compounds exhibited low inhibition against human normal 2BS cells. Moreover, compounds 8d and 9b showed outstanding activity against FAK with IC50 values of 0.2438 nM and 0.2691 nM, which was very close to TAE-226 (IC50 = 0.1390 nM). Further studies proved that compounds 8d and 9b could induce U87-MG cell early apoptosis and arrest the cell at G2/M phase. The action mechanism indicated that they could significantly inhibit U87-MG cell clone formation, cell migration, and FAK phosphorylation. Molecular docking and molecular dynamics simulation investigations suggested that compounds 8d and 9b could firmly occupy the ATP binding site of FAK. These findings supported the further researches of compounds 8d and 9b as FAK inhibitors for antitumor drug discovery.

Focal adhesion kinase (FAK): its structure, characteristics, and signaling in skeletal system

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase and distributes important regulatory functions in skeletal system. Mesenchymal stem cell (MSC) possesses significant migration and differentiation capacity, is an important source of distinctive bone cells production and a prominent bone development pathway. MSC has a wide range of applications in tissue bioengineering and regenerative medicine, and is frequently employed for hematopoietic support, immunological regulation, and defect repair, although current research is insufficient. FAK has been identified to cross-link with many other keys signaling pathways in bone biology and is considered as a fundamental "crossroad" on the signal transduction pathway and a "node" in the signal network to mediate MSC lineage development in skeletal system. In this review, we summarized the structure, characteristics, cellular signaling, and the interactions of FAK with other signaling pathways in the skeletal system. The discovery of FAK and its mediated molecules will lead to a new knowledge of bone development and bone construction as well as considerable potential for therapeutic use in the treatment of bone-related disorders such as osteoporosis, osteoarthritis, and osteosarcoma.

Discovery of novel pyrrolo [2,3-d] pyrimidine derivatives as potent FAK inhibitors based on cyclization strategy

Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, plays a pivotal role in tumor invasion and metastasis. Many FAK inhibitors had been reported, but the development of FAK inhibitors in clinical studies are still limited. To facilitate the discovery of FAK modulators and further elucidate the role of FAK in cancer metastasis, it is necessary to discover a novel, potent and selective FAK inhibitor. In this study, a series of FAK inhibitors with novel scaffold were designed and synthesized based on cyclization strategy. Here, we reported compound 10b (HMC-18NH) with excellent inhibition of FAK (IC50 = 9.9 nM) and anticancer activity against several cancer cell lines including BxPC-3, PANC-1, MCF-7, MDA-MB-231, U-87MG, HepG2, HCT-15 and A549. Extraordinary, compound 10b showed the best cytotoxic effects against A549 with the IC50 value of 0.8 μM. In addition, 10b exhibited effective invasion and migration suppression in A549 cells. Further investigations revealed that compound 10b potently induced and promoted apoptosis in a dose-dependent manner and arrested A549 cells in the G2/M phase. Collectively, these results suggest that 10b is a promising FAK inhibitor and serve as a lead compound which deserve for further optimization.

Identification of defactinib derivatives targeting focal adhesion kinase using ensemble docking, molecular dynamics simulations and binding free energy calculations

Focal adhesion kinase (FAK) belongs to the nonreceptor tyrosine kinases, which selectively phosphorylate tyrosine residues on substrate proteins. FAK is associated with bladder, esophageal, gastric, neck, breast, ovarian and lung cancers. Thus, FAK has been considered as a potential target for tumor treatment. Currently, there are six adenosine triphosphate (ATP)-competitive FAK inhibitors tested in clinical trials but no approved inhibitors targeting FAK. Defactinib (VS-6063) is a second-generation FAK inhibitor with an IC50 of 0.6 nM. The binding model of VS-6063 with FAK may provide a reference model for developing new antitumor FAK-targeting drugs. In this study, the VS-6063/FAK binding model was constructed using ensemble docking and molecular dynamics simulations. Furthermore, the molecular mechanics/generalized Born (GB) surface area (MM/GBSA) method was employed to estimate the binding free energy between VS-6063 and FAK. The key residues involved in VS-6063/FAK binding were also determined using per-residue energy decomposition analysis. Based on the binding model, VS-6063 could be separated into seven regions to enhance its binding affinity with FAK. Meanwhile, 60 novel defactinib-based compounds were designed and verified using ensemble docking. Overall, the present study improves our understanding of the binding mechanism of human FAK with VS-6063 and provides new insights into future drug designs targeting FAK.Communicated by Ramaswamy H. Sarma.

On the Value of In Vitro Cell Systems for Mechanobiology from the Perspective of Yes-Associated Protein/Transcriptional Co-Activator with a PDZ-Binding Motif and Focal Adhesion Kinase and Their Involvement in Wound Healing, Cancer, Aging, and Senescence

Mechanobiology comprises how cells perceive different mechanical stimuli and integrate them into a process called mechanotransduction; therefore, the related mechanosignaling cascades are generally important for biomedical research. The ongoing discovery of key molecules and the subsequent elucidation of their roles in mechanobiology are fundamental to understanding cell responses and tissue conditions, such as homeostasis, aging, senescence, wound healing, and cancer. Regarding the available literature on these topics, it becomes abundantly clear that in vitro cell systems from different species and tissues have been and are extremely valuable tools for enabling the discovery and functional elucidation of key mechanobiological players. Therefore, this review aims to discuss the significant contributions of in vitro cell systems to the identification and characterization of three such key players using the selected examples of yes-associated protein (YAP), its paralog transcriptional co-activator with a PDZ-binding motif (TAZ), and focal adhesion kinase (FAK) and their involvement in wound healing, cancer, aging, and senescence. In addition, the reader is given suggestions as to which future prospects emerge from the in vitro studies discussed herein and which research questions still remain open.

Molecular signaling network and therapeutic developments in breast cancer brain metastasis

Breast cancer (BC) is one of the most frequently diagnosed cancers in women worldwide. It has surpassed lung cancer as the leading cause of cancer-related death. Breast cancer brain metastasis (BCBM) is becoming a major clinical concern that is commonly associated with ER-ve and HER2+ve subtypes of BC patients. Metastatic lesions in the brain originate when the cancer cells detach from a primary breast tumor and establish metastatic lesions and infiltrate near and distant organs via systemic blood circulation by traversing the BBB. The colonization of BC cells in the brain involves a complex interplay in the tumor microenvironment (TME), metastatic cells, and brain cells like endothelial cells, microglia, and astrocytes. BCBM is a significant cause of morbidity and mortality and presents a challenge to developing successful cancer therapy. In this review, we discuss the molecular mechanism of BCBM and novel therapeutic strategies for patients with brain metastatic BC.

FAK inhibitor PF-562271 inhibits the migration and proliferation of high-grade serous ovarian cancer cells through FAK and FAK mediated cell cycle arrest

Focal adhesion kinase (FAK) is a promising therapeutic target for various cancers and its inhibitor development is in full swing. PF-562271 is a classic FAK inhibitor that has shown promising preclinical data and has been found to exhibit an anti-migration effect on some cancer cells. However, its anticancer effect on high-grade serous ovarian cancer (HGSOC) has not been reported. In this study, we evaluated the anti-migration and anti-proliferation effects of PF-562271 against HGSOC SKOV3 and A2780 cells, as well as the underlying mechanism. The results demonstrated that FAK was overexpressed in clinical HGSOC tissues and was positively correlated with the pathological progression of HGSOC. Moreover, HGSOC patients with high FAK expression levels exhibited low survival rates. PF-562271 treatment significantly inhibited the cell adhesion and migration of SKOV3 and A2780 cells by inhibiting p-FAK expression and decreasing the FA surface area. Additionally, PF-562271 treatment inhibited colony formation and induced cell senescence through G1 phase cell cycle arrest mediated DNA replication inhibition. Taken together, the findings demonstrated that FAK inhibitor PF-562271 significantly inhibits HGSOC cell adhesion, migration, and proliferation process through FAK and/or FAK mediated cell cycle arrest, and suggested that PF-562271 could serve as a potential oncotherapeutic agent for HGSOC targeting treatment.

A Triazaspirane Derivative Inhibits Migration and Invasion in PC3 Prostate Cancer Cells

Cancer is a serious health problem due to the complexity of establishing an effective treatment. The purpose of this work was to evaluate the activity of a triazaspirane as a migration and invasion inhibitor in PC3 prostatic tumor cells through a possible negative regulation of the FAK/Src signal transduction pathway and decreased secretion of metalloproteinases 2 and 9. Molecular docking analysis was performed using Moe 2008.10 software. Migration (wound-healing assay) and invasion (Boyden chamber assay) assays were performed. In addition, the Western blot technique was used to quantify protein expression, and the zymography technique was used to observe the secretion of metalloproteinases. Molecular docking showed interactions in regions of interest of the FAK and Src proteins. Moreover, the biological activity assays demonstrated an inhibitory effect on cell migration and invasion, an important suppression of metalloproteinase secretion, and a decrease in the expression of p-FAK and p-Src proteins in treated PC3 cells. Triazaspirane-type molecules have important inhibitory effects on the mechanisms associated with metastasis in PC3 tumor cells.

Antitumor Activity of s-Triazine Derivatives: A Systematic Review

1,3,5-triazine derivatives, also called s-triazines, are a series of containing-nitrogen heterocyclic compounds that play an important role in anticancer drug design and development. To date, three s-triazine derivatives, including altretamine, gedatolisib, and enasidenib, have already been approved for refractory ovarian cancer, metastatic breast cancer, and leukemia therapy, respectively, demonstrating that the s-triazine core is a useful scaffold for the discovery of novel anticancer drugs. In this review, we mainly focus on s-triazines targeting topoisomerases, tyrosine kinases, phosphoinositide 3-kinases, NADP+-dependent isocitrate dehydrogenases, and cyclin-dependent kinases in diverse signaling pathways, which have been extensively studied. The medicinal chemistry of s-triazine derivatives as anticancer agents was summarized, including discovery, structure optimization, and biological applications. This review will provide a reference to inspire new and original discoveries.

Identification of abemaciclib derivatives targeting cyclin-dependent kinase 4 and 6 using molecular dynamics, binding free energy calculation, synthesis, and pharmacological evaluation

CDK4/6 plays a crucial role in various cancers and is an effective anticancer drug target. However, the gap between clinical requirements and approved CDK4/6 drugs is unresolved. Thus, there is an urgent need to develop selective and oral CDK4/6 inhibitors, particularly for monotherapy. Here, we studied the interaction between abemaciclib and human CDK6 using molecular dynamics simulations, binding free energy calculations, and energy decomposition. V101 and H100 formed stable hydrogen bonds with the amine-pyrimidine group, and K43 interacted with the imidazole ring via an unstable hydrogen bond. Meanwhile, I19, V27, A41, and L152 interacted with abemaciclib through π-alkyl interactions. Based on the binding model, abemaciclib was divided into four regions. With one region modification, 43 compounds were designed and evaluated using molecular docking. From each region, three favorable groups were selected and combined with each other to obtain 81 compounds. Among them, C2231-A, which was obtained by removing the methylene group from C2231, showed better inhibition than C2231. Kinase profiling revealed that C2231-A showed inhibitory activity similar to that of abemaciclib; additionally, C2231-A inhibited the growth of MDA-MB-231 cells to a greater extent than did abemaciclib. Based on molecular dynamics simulation, C2231-A was identified as a promising candidate compound with considerable inhibitory effects on human breast cancer cell lines.

Dual roles of FAK in tumor angiogenesis: A review focused on pericyte FAK

Focal adhesion kinase (FAK), also known as protein tyrosine kinase 2 (PTK2), is a ubiquitously expressed non-receptor tyrosine kinase, that plays a pivotal role in integrin-mediated signal transduction. Endothelial FAK is upregulated in many types of cancer and promotes tumorigenesis and tumor progression. However, recent studies have shown that pericyte FAK has the opposite effect. This review article dissects the mechanisms, by which endothelial cells (ECs) and pericyte FAK regulate angiogenesis, with an emphasis on the Gas6/Axl pathway. In particular, this article discusses the role of pericyte FAK loss on angiogenesis during tumorigenesis and metastasis. In addition, the existing challenges and future application of drug-based anti-FAK targeted therapies will be discussed to provide a theoretical basis for further development and use of FAK inhibitors.

Recent development of multi-target VEGFR-2 inhibitors for the cancer therapy

Vascular epidermal growth factor receptor-2 (VEGFR-2), as an important tyrosine transmembrane protein, plays an important role in regulating endothelial cell proliferation and migration, regulating angiogenesis and other biological functions. VEGFR-2 is aberrantly expressed in many malignant tumors, and it is also related to the occurrence, development, and growth of tumors and drug resistance. Currently, there are nine VEGFR-2 targeted inhibitors approved by US.FDA for clinical use as anticancer drugs. Due to the limited clinical efficacy and potential toxicity of VEGFR inhibitors, it is necessary to develop new strategies to improve the clinical efficacy of VEGFR inhibitors. The development of multitarget therapy, especially dual-target therapy, has become a hot research field of cancer therapy, which may provide an effective strategy with higher therapeutic efficacy, pharmacokinetic advantages and low toxicity. Many groups have reported that the therapeutic effects could be improved by simultaneously inhibiting VEGFR-2 and other targets, such as EGFR, c-Met, BRAF, HDAC, etc. Therefore, VEGFR-2 inhibitors with multi-targeting capabilities have been considered to be promising and effective anticancer agents for cancer therapy. In this work, we reviewed the structure and biological functions of VEGFR-2, and summarized the drug discovery strategies, and inhibitory activities of VEGFR-2 inhibitors with multi-targeting capabilities reported in recent years. This work might provide the reference for the development of VEGFR-2 inhibitors with multi-targeting capabilities as novel anticancer agents.

Novel Steroidal[17,16-d]pyrimidines Derived from Epiandrosterone and Androsterone: Synthesis, Characterization and Configuration-Activity Relationships

Two series of novel steroidal[17,16-d]pyrimidines derived from natural epiandrosterone and androsterone were designed and synthesized, and these compounds were screened for their potential anticancer activities. The preliminary bioassay indicated that some of these prepared compounds exhibited significantly good cytotoxic activities against human gastric cancer (SGC-7901), lung cancer (A549), and hepatocellular liver carcinoma (HepG2) cell lines compared with 5-fluorouracil (5-FU), epiandrosterone, and androsterone. Especially the respective pairs from epiandrosterone and androsterone showed significantly different inhibitory activities, and the possible configuration-activity relationships have also been summarized and discussed based on kinase assay and molecular docking, which indicated that the inhibition activities of these steroidal[17,16-d]pyrimidines might obviously be affected by the configuration of the hydroxyl group in the part of the steroidal scaffold.

Lipopolyplex-Mediated Co-Delivery of Doxorubicin and FAK siRNA to Enhance Therapeutic Efficiency of Treating Colorectal Cancer

Tumor metastasis is a major concern in cancer therapy. In this context, focal adhesion kinase (FAK) gene overexpression, which mediates cancer cell migration and invasion, has been reported in several human tumors and is considered a potential therapeutic target. However, gene-based treatment has certain limitations, including a lack of stability and low transfection ability. In this study, a biocompatible lipopolyplex was synthesized to overcome the aforementioned limitations. First, polyplexes were prepared using poly(2-Hydroxypropyl methacrylamide-co-methylacrylate-hydrazone-pyridoxal) (P(HPMA-co-MA-hyd-VB6)) copolymers, which bore positive charges at low pH value owing to protonation of pyridoxal groups and facilitated electrostatic interactions with negatively charged FAK siRNA. These polyplexes were then encapsulated into methoxy polyethylene glycol (mPEG)-modified liposomes to form lipopolyplexes. Doxorubicin (DOX) was also loaded into lipopolyplexes for combination therapy with siRNA. Experimental results revealed that lipopolyplexes successfully released DOX at low pH to kill cancer cells and induced siRNA out of endosomes to inhibit the translation of FAK proteins. Furthermore, the efficient accumulation of lipopolyplexes in the tumors led to excellent cancer therapeutic efficacy. Overall, the synthesized lipopolyplex is a suitable nanocarrier for the co-delivery of chemotherapeutic agents and genes to treat cancers.

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

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

Interactions between curcumin and human salt-induced kinase 3 elucidated from computational tools and experimental methods

Natural products are widely used for treating mitochondrial dysfunction-related diseases and cancers. Curcumin, a well-known natural product, can be potentially used to treat cancer. Human salt-induced kinase 3 (SIK3) is one of the target proteins for curcumin. However, the interactions between curcumin and human SIK3 have not yet been investigated in detail. In this study, we studied the binding models for the interactions between curcumin and human SIK3 using computational tools such as homology modeling, molecular docking, molecular dynamics simulations, and binding free energy calculations. The open activity loop conformation of SIK3 with the ketoenol form of curcumin was the optimal binding model. The I72, V80, A93, Y144, A145, and L195 residues played a key role for curcumin binding with human SIK3. The interactions between curcumin and human SIK3 were also investigated using the kinase assay. Moreover, curcumin exhibited an IC₅₀ (half-maximal inhibitory concentration) value of 131 nM, and it showed significant antiproliferative activities of 9.62 ± 0.33 µM and 72.37 ± 0.37 µM against the MCF-7 and MDA-MB-23 cell lines, respectively. This study provides detailed information on the binding of curcumin with human SIK3 and may facilitate the design of novel salt-inducible kinases inhibitors.

An overview of PROTACs: a promising drug discovery paradigm

Proteolysis targeting chimeras (PROTACs) technology has emerged as a novel therapeutic paradigm in recent years. PROTACs are heterobifunctional molecules that degrade target proteins by hijacking the ubiquitin-proteasome system. Currently, about 20-25% of all protein targets are being studied, and most works focus on their enzymatic functions. Unlike small molecules, PROTACs inhibit the whole biological function of the target protein by binding to the target protein and inducing subsequent proteasomal degradation. PROTACs compensate for limitations that transcription factors, nuclear proteins, and other scaffolding proteins are difficult to handle with traditional small-molecule inhibitors. Currently, PROTACs have successfully degraded diverse proteins, such as BTK, BRD4, AR, ER, STAT3, IRAK4, tau, etc. And ARV-110 and ARV-471 exhibited excellent efficacy in clinical II trials. However, what targets are appropriate for PROTAC technology to achieve better benefits than small-molecule inhibitors are not fully understood. And how to rationally design an efficient PROTACs and optimize it to be orally effective poses big challenges for researchers. In this review, we summarize the features of PROTAC technology, analyze the detail of general principles for designing efficient PROTACs, and discuss the typical application of PROTACs targeting different protein categories. In addition, we also introduce the progress of relevant clinical trial results of representative PROTACs and assess the challenges and limitations that PROTACs may face. Collectively, our studies provide references for further application of PROTACs.

Overcoming resistance of stroma-rich pancreatic cancer with focal adhesion kinase inhibitor combined with G47Δ and immune checkpoint inhibitors

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease known for its dense tumor stroma. Focal adhesion kinase inhibitor (FAKi), a non-receptor type tyrosine kinase inhibitor, reduces the tumor stroma. G47Δ, a third-generation oncolytic herpes simplex virus type 1, destroys tumor cells selectively and induces antitumor immune responses. This study evaluates the efficacy of FAKi and G47Δ in PDAC models in combination with or without immune checkpoint inhibitors. G47Δ was effective in human PDAC cell lines in vitro and in subcutaneous as well as orthotopic tumor models. Transgenic mouse-derived #146 cells were used to generate subcutaneous PDAC tumors with rich stroma in immunocompetent mice. In this #146 tumor model, the efficacy of FAKi was synergistically augmented when combined with G47Δ, which reflected not only a decreased stromal content but also a significant shifting of the tumor microenvironment toward immune stimulation. In transgenic autochthonous PKF mice, a rare model that develops stroma-rich PDAC with a 100% penetrance and resembles human PDAC in various aspects, the prolongation of survival compared with FAKi alone was achieved only when FAKi was combined with G47Δ and immune checkpoint inhibitors. The FAKi combination therapy may be useful to overcome the treatment resistance of stroma-rich PDAC.

The mechanical cell - the role of force dependencies in synchronising protein interaction networks

The role of mechanical signals in the proper functioning of organisms is increasingly recognised, and every cell senses physical forces and responds to them. These forces are generated both from outside the cell or via the sophisticated force-generation machinery of the cell, the cytoskeleton. All regions of the cell are connected via mechanical linkages, enabling the whole cell to function as a mechanical system. In this Review, we define some of the key concepts of how this machinery functions, highlighting the critical requirement for mechanosensory proteins, and conceptualise the coupling of mechanical linkages to mechanochemical switches that enables forces to be converted into biological signals. These mechanical couplings provide a mechanism for how mechanical crosstalk might coordinate the entire cell, its neighbours, extending into whole collections of cells, in tissues and in organs, and ultimately in the coordination and operation of entire organisms. Consequently, many diseases manifest through defects in this machinery, which we map onto schematics of the mechanical linkages within a cell. This mapping approach paves the way for the identification of additional linkages between mechanosignalling pathways and so might identify treatments for diseases, where mechanical connections are affected by mutations or where individual force-regulated components are defective.

Molecular Docking, Molecular Dynamics Simulations, and Free Energy Calculation Insights into the Binding Mechanism between VS-4718 and Focal Adhesion Kinase

Focal adhesion kinase (FAK) is a 125 kDa nonreceptor tyrosine kinase that plays an important role in many carcinomas. Thus, the targeting of FAK by small molecules is considered to be promising for cancer therapy. Some FAK inhibitors have been reported as potential anticancer drugs and have entered into clinical development; for example, VS-4718 is currently undergoing clinical trials. However, the lack of crystal structural data for the binding of VS-4718 with FAK has hindered the optimization of this anticancer agent. In this work, the VS-4718/FAK interaction model was obtained by molecular docking and molecular dynamics simulations. The binding free energies of VS-4718/FAK were also calculated using the molecular mechanics generalized Born surface area method. It was found that the aminopyrimidine group formed hydrogen bonds with the C502 residue of the hinge loop, while the D564 residue of the T-loop interacted with the amide group. In addition, I428, A452, V484, M499, G505, and L553 residues formed hydrophobic interactions with VS-4718. The obtained results therefore provide an improved understanding of the interaction between human FAK and VS-4718. Based on the obtained binding mechanism, 47 novel compounds were designed to target the adenosine 5'-triphosphate-binding pocket of human FAK, and ensemble docking was performed to assess the effects of these modifications on the inhibitor binding affinity. This work is also expected to provide additional insights into potential future target design strategies based on VS-4718.

Anti-Cancer Activity of the Combinational Treatment of Noozone Cold Plasma with p-FAK Antibody-Conjugated Gold Nanoparticles in OSCC Xenograft Mice

Oral squamous cell cancer (OSCC) is the most common type of oral cancer (about 80–90% of cases) and various research is being done to cure the disease. This paper aims to verify whether treatment with no-ozone cold plasma (NCP), which is designed for safe usage of the plasma on oral cavities, in combination with gold nanoparticles conjugated with p-FAK antibody (p-FAK/GNP) can trigger the selective and instant killing of SCC-25 cells both in vitro and in vivo. When SCC25 and HaCaT cells are exposed to p-FAK/GNP+NCP, the instant cell death was observed only in SCC25 cells. Such p-FAK/GNP+NCP-mediated cell death was observed only when NCP was directly treated on SCC25 harboring p-FAK/GNP. During NCP treatment, the removal of charged particles from NCP using grounded electric mesh radically decreased the p-FAK/GNP+NCP-mediated cell death. This p-FAK/GNP+NCP-mediated selective cell death of OSCC was also observed in mice xenograft models using SCC25 cells. The mere treatment of p-FAK/GNP and NCP on the xenograft tumor slowly decreased the size of the tumor, and only about 50% of the tumor remained at the end of the experiment. On the other hand, 1 week of p-FAK/GNP+NCP treatment was enough to reduce half of the tumor size, and most of tumor tissue had vanished at the end. An analysis of isolated tissues showed that in the case of individual treatment with p-FAK/GNP or NCP, the cancer cell population was reduced due to apoptotic cell death. However, in the case of p-FAK/GNP+NCP, apoptotic cell death was unobserved, and most tissues were composed of collagen. Thus, this paper suggests the possibility of p-FAK/GNP+NCP as a new method for treating OSCC.

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

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

The dawn of precision medicine in diffuse-type gastric cancer

Gastric cancer (GC) is one of the most common malignancies worldwide. The histology- and morphology-based Lauren classification of GC has been widely used for over 50 years in clinical practice. The Lauren classification divides GC into intestinal and diffuse types, which have distinct etiology, molecular profiles, and clinicopathological features. Diffuse-type GC (DGC) accounts for approximately 30% of GCs. Tumor cells lack adhesion and infiltrate the stroma as single cells or small subgroups, leading to easy dissemination in the abdominal cavity. Clinically, DGC has aggressive traits with a high risk of recurrence and metastasis, which results in unfavorable prognosis. Although systemic chemotherapy is the main therapeutic approach for recurrent or metastatic GC patients, clinical benefits are limited for patients with DGC. Therefore, it is urgent to develop effective therapeutic strategies for DGC patients. Considerable research studies have characterized the molecular and genomic landscape of DGC, of which tight junction protein claudin-18 isoform 2 (CLDN18.2) and fibroblast growing factors receptor-2 isoform IIIb (FGFR2-IIIb) are the most attractive targets because of their close association with DGC. Recently, the impressive results of two phase II FAST and FIGHT trials demonstrate proof-of-concept, suggesting that anti-CLDN18.2 antibody (zolbetuximab) and FGFR2-IIIb antibody (bemarituzumab) are promising approaches for patients with CLDN18.2-positive and FGFR2-IIIb-positive GC, respectively. In this review, we summarize the clinicopathological features and molecular profiles of DGC and highlight a potential therapeutic target based on the findings of pivotal clinical trials.