Focal Adhesion Kinase Regulates the DNA Damage Response and Its Inhibition Radiosensitizes Mutant KRAS Lung Cancer

ERK5 suppression overcomes FAK inhibitor resistance in mutant KRAS-driven non-small cell lung cancer

Mutated KRAS serves as the oncogenic driver in 30% of non-small cell lung cancers (NSCLCs) and is associated with metastatic and therapy-resistant tumors. Focal Adhesion Kinase (FAK) acts as a mediator in sustaining KRAS-driven lung tumors, and although FAK inhibitors are currently undergoing clinical development, clinical data indicated that their efficacy in producing long-term anti-tumor responses is limited. Here we revealed two FAK interactors, extracellular-signal-regulated kinase 5 (ERK5) and cyclin-dependent kinase 5 (CDK5), as key players underlying FAK-mediated maintenance of KRAS mutant NSCLC. Inhibition of ERK5 and CDK5 synergistically suppressed FAK function, decreased proliferation and induced apoptosis owing to exacerbated ROS-induced DNA damage. Accordingly, concomitant pharmacological inhibition of ERK5 and CDK5 in a mouse model of KrasG12D-driven lung adenocarcinoma suppressed tumor progression and promoted cancer cell death. Cancer cells resistant to FAK inhibitors showed enhanced ERK5-FAK signaling dampening DNA damage. Notably, ERK5 inhibition prevented the development of resistance to FAK inhibitors, significantly enhancing the efficacy of anti-tumor responses. Therefore, we propose ERK5 inhibition as a potential co-targeting strategy to counteract FAK inhibitor resistance in NSCLC.

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.

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.

A highly potent bi-thiazole inhibitor of LOX rewires collagen architecture and enhances chemoresponse in triple-negative breast cancer

Lysyl oxidase (LOX) is upregulated in highly stiff aggressive tumors, correlating with metastasis, resistance, and worse survival; however, there are currently no potent, safe, and orally bioavailable small molecule LOX inhibitors to treat these aggressive desmoplastic solid tumors in clinics. Here we discovered bi-thiazole derivatives as potent LOX inhibitors by robust screening of drug-like molecules combined with cell/recombinant protein-based assays. Structure-activity relationship analysis identified a potent lead compound (LXG6403) with ∼3.5-fold specificity for LOX compared to LOXL2 while not inhibiting LOXL1 with a competitive, time- and concentration-dependent irreversible mode of inhibition. LXG6403 shows favorable pharmacokinetic properties, globally changes ECM/collagen architecture, and reduces tumor stiffness. This leads to better drug penetration, inhibits FAK signaling, and induces ROS/DNA damage, G1 arrest, and apoptosis in chemoresistant triple-negative breast cancer (TNBC) cell lines, PDX organoids, and in vivo. Overall, our potent and tolerable bi-thiazole LOX inhibitor enhances chemoresponse in TNBC, the deadliest breast cancer subtype.

An Updated Review on KRAS Mutation in Lung Cancer (NSCLC) and Its Effects on Human Health

The largest cause of cancer-related fatalities worldwide is lung cancer. In its early stages, lung cancer often exhibits no signs or symptoms. Its signs and symptoms often appear when the condition is advanced. The Kirsten rat sarcoma virus oncogene homolog is one of the most frequently mutated oncogenes found in non-small cell lung cancer. Patients who have these mutations may do worse than those who do not, in terms of survival. To understand the nuances in order to choose the best treatment options for each patient, including combination therapy and potential resistance mechanisms, given the quick development of pharmaceuticals, it is necessary to know the factors that might contribute to this disease. It has been observed that single nucleotide polymorphisms altering let-7 micro-RNA might impact cancer propensity. On the other hand, gefitinib fails to stop the oncogenic protein from directly interacting with phosphoinositide3-kinase, which may explain its resistance towards cancer cells. Additionally, Atorvastatin may be able to overpower gefitinib resistance in these cancer cells that have this mutation regardless of the presence of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha. De novo lipogenesis is also regulated by this virus. To overcome these effects, several targeted therapies have been proposed. One such therapy is to use inhibitors of focal adhesion kinases. When this is inhibited, viral oncogene mutant cancers are effectively stopped because it functions downstream of the virus. Mutant oncoproteins like epidermal growth factor receptor may depend on Heat Shock protein90 chaperones more frequently than they do on natural counterparts that make it more attractive therapeutic target for this virus. Inhibition of the phosphoinositide 3-kinase pathway is frequent in lung cancer, and fabrication of inhibitors against this pathway can also be an effective therapeutic strategy. Blocking programmed cell death ligand1 is another therapy that may help T cells to recognize and eliminate cancerous cells. This homolog is a challenging therapeutic target due to its complex structural makeup and myriad biological characteristics. Thanks to the unrelenting efforts of medical research, with the use of some inhibitors, immunotherapy, and other combination methods, this problem is currently expected to be overcome.

CRISPR-Based Gene Editing: a Modern Approach for Study and Treatment of Cancer

The development and emergence of clustered regularly interspaced short palindromic repeats (CRISPR) as a genome-editing technology have created a plethora of opportunities in genetic engineering. The ability of sequence-specific addition or removal of DNA in an efficient and cost-effective manner has revolutionized modern research in the field of life science and healthcare. CRISPR is widely used as a genome engineering tool in clinical studies for observing gene expression and metabolic pathway regulations in detail. Even in the case of transgenic research and personalized gene manipulation studies, CRISPR-based technology is used extensively. To understand and even to correct the underlying genetic problem is of cancer, CRISPR-based technology can be used. Various kinds of work is going on throughout the world which are attempting to target different genes in order to discover novel and effective methodologies for the treatment of cancer. In this review, we provide a brief overview on the application of CRISPR gene editing technology in cancer treatment focusing on the key aspects of cancer screening, modelling and therapy techniques.

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

BACKGROUND

Recent therapeutic strategies for KRAS-mutated cancers that inhibit the MAPK pathway have attracted considerable attention. The RAF/MEK clamp avutometinib (VS-6766/CH5126766/RO5126766/CKI27) is promising for patients with KRAS-mutated cancers. Although avutometinib monotherapy has shown clinical activity in patients with KRAS-mutated cancers, effective combination strategies will be important to develop.

METHODS

Using a phosphorylation kinase array kit, we explored the feedback mechanism of avutometinib in KRAS-mutated NSCLC cells, and investigated the efficacy of combining avutometinib with inhibitors of the feedback signal using in vitro and in vivo experiments. Moreover, we searched for a biomarker for the efficacy of combination therapy through an in vitro study and analysis using the The Cancer Genome Atlas Programme dataset.

RESULTS

Focal adhesion kinase (FAK) phosphorylation/activation was increased after avutometinib treatment and synergy between avutometinib and FAK inhibitor, defactinib, was observed in KRAS-mutated NSCLC cells with an epithelial rather than mesenchymal phenotype. Combination therapy with avutometinib and defactinib induced apoptosis with upregulation of Bim in cancer cells with an epithelial phenotype in an in vitro and in vivo study.

CONCLUSIONS

These results demonstrate that the epithelial-mesenchymal transition status may be a promising biomarker for the efficacy of combination therapy with avutometinib and defactinib in KRAS-mutated NSCLC.

Engineering CRISPR/Cas9 therapeutics for cancer precision medicine

The discovery of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) technology has revolutionized field of cancer treatment. This review explores usage of CRISPR/Cas9 for editing and investigating genes involved in human carcinogenesis. It provides insights into the development of CRISPR as a genetic tool. Also, it explores recent developments and tools available in designing CRISPR/Cas9 systems for targeting oncogenic genes for cancer treatment. Further, we delve into an overview of cancer biology, highlighting key genetic alterations and signaling pathways whose deletion prevents malignancies. This fundamental knowledge enables a deeper understanding of how CRISPR/Cas9 can be tailored to address specific genetic aberrations and offer personalized therapeutic approaches. In this review, we showcase studies and preclinical trials that show the utility of CRISPR/Cas9 in disrupting oncogenic targets, modulating tumor microenvironment and increasing the efficiency of available anti treatments. It also provides insight into the use of CRISPR high throughput screens for cancer biomarker identifications and CRISPR based screening for drug discovery. In conclusion, this review offers an overview of exciting developments in engineering CRISPR/Cas9 therapeutics for cancer treatment and highlights the transformative potential of CRISPR for innovation and effective cancer treatments.

Targeting of focal adhesion kinase enhances the immunogenic cell death of PEGylated liposome doxorubicin to optimize therapeutic responses of immune checkpoint blockade

BACKGROUNDS

Immune checkpoint blockade (ICB) is widely considered to exert long-term treatment benefits by activating antitumor immunity. However, many cancer patients show poor clinical responses to ICB due in part to the lack of an immunogenic niche. Focal adhesion kinase (FAK) is frequently amplified and acts as an immune modulator across cancer types. However, evidence illustrates that targeting FAK is most effective in combination therapy rather than in monotherapy.

METHODS

Here, we used drug screening, in vitro and in vivo assays to filter out that doxorubicin and its liposomal form pegylated liposome doxorubicin (PLD) showed synergistic anti-tumor effects in combination with FAK inhibitor IN10018. We hypothesized that anti-tumor immunity and immunogenic cell death (ICD) may be involved in the treatment outcomes through the data analysis of our clinical trial testing the combination of IN10018 and PLD. We then performed cell-based assays and animal studies to detect whether FAK inhibition by IN10018 can boost the ICD of PLD/doxorubicin and further established syngeneic models to test the antitumor effect of triplet combination of PLD, IN10018, and ICB.

RESULTS

We demonstrated that the combination of FAK inhibitor IN10018, and PLD/doxorubicin exerted effective antitumor activity. Notably, the doublet combination regimen exhibited response latency and long-lasting treatment effects clinically, outcomes frequently observed in immunotherapy. Our preclinical study confirmed that the 2-drug combination can maximize the ICD of cancer cells. This approach primed the tumor microenvironment, supplementing it with sufficient tumor-infiltrating lymphocytes (TILs) to activate antitumor immunity. Finally, different animal studies confirmed that the antitumor effects of ICB can be significantly enhanced by this doublet regimen.

CONCLUSIONS

We confirmed that targeting FAK by IN10018 can enhance the ICD of PLD/doxorubicin, further benefiting the anti-tumor effect of ICB. The animal tests of the triplet regimen warrant further discovery in the real world.

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.

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

PURPOSE

Radiation and platinum-based chemotherapy form the backbone of therapy in human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC). We have correlated focal adhesion kinase (FAK/PTK2) expression with radioresistance and worse outcomes in these patients. However, the importance of FAK in driving radioresistance and its effects on chemoresistance in these patients remains unclear.

EXPERIMENTAL DESIGN

We performed an in vivo shRNA screen using targetable libraries to identify novel therapeutic sensitizers for radiation and chemotherapy.

RESULTS

We identified FAK as an excellent target for both radio- and chemosensitization. Because TP53 is mutated in over 80% of HPV-negative HNSCC, we hypothesized that mutant TP53 may facilitate FAK-mediated therapy resistance. FAK inhibitor increased sensitivity to radiation, increased DNA damage, and repressed homologous recombination and nonhomologous end joining repair in mutant, but not wild-type, TP53 HPV-negative HNSCC cell lines. The mutant TP53 cisplatin-resistant cell line had increased FAK phosphorylation compared with wild-type, and FAK inhibition partially reversed cisplatin resistance. To validate these findings, we utilized an HNSCC cohort to show that FAK copy number and gene expression were associated with worse disease-free survival in mutant TP53, but not wild-type TP53, HPV-negative HNSCC tumors.

CONCLUSIONS

FAK may represent a targetable therapeutic sensitizer linked to a known genomic marker of resistance.

Applications and advancements of CRISPR-Cas in the treatment of lung cancer

Lung cancer is one of the most malignant diseases and a major contributor to cancer-related deaths worldwide due to the deficiency of early diagnosis and effective therapy that are of great importance for patient prognosis and quality of life. Over the past decade, the advent of clustered regularly interspaced short palindromic repeats/CRISPR associated protein (CRISPR/Cas) system has significantly propelled the progress of both fundamental research and clinical trials of lung cancer. In this review, we review the current applications of the CRISPR/Cas system in diagnosis, target identification, and treatment resistance of lung cancer. Furthermore, we summarize the development of lung cancer animal models and delivery methods based on CRISPR system, providing novel insights into clinical diagnosis and treatment strategies of lung cancer.

Modern therapies of nonsmall cell lung cancer

Lung cancer (LC), particularly nonsmall cell lung cancer (NSCLC), is one of the most prevalent types of neoplasia worldwide, regardless of gender, with the highest mortality rates in oncology. Over the years, treatment for NSCLC has evolved from conventional surgery, chemotherapy, and radiotherapy to more tailored and minimally invasive approaches. The use of personalised therapies has increased the expected efficacy of treatment while simultaneously reducing the frequency of severe adverse effects (AEs). In this review, we discuss established modern approaches, including immunotherapy and targeted therapy, as well as experimental molecular methods like clustered regularly interspaced short palindromic repeat (CRISPR) and nanoparticles. These emerging methods offer promising outcomes and shorten the recovery time for various patients. Recent advances in the diagnostic field, including imaging and genetic profiling, have enabled the implementation of these methods. The versatility of these modern therapies allows for multiple treatment options, such as single-agent use, combination with existing conventional treatments, or incorporation into new regimens. As a result, patients can survive even in the advanced stages of NSCLC, leading to increased survival indicators such as overall survival (OS) and progression-free survival (PFS).

YB-1 activating cascades as potential targets in KRAS-mutated tumors

Y‑box binding protein‑1 (YB-1) is a multifunctional protein that is highly expressed in human solid tumors of various entities. Several cellular processes, e.g. cell cycle progression, cancer stemness and DNA damage signaling that are involved in the response to chemoradiotherapy (CRT) are tightly governed by YB‑1. KRAS gene with about 30% mutations in all cancers, is considered the most commonly mutated oncogene in human cancers. Accumulating evidence indicates that oncogenic KRAS mediates CRT resistance. AKT and p90 ribosomal S6 kinase are downstream of KRAS and are the major kinases that stimulate YB‑1 phosphorylation. Thus, there is a close link between the KRAS mutation status and YB‑1 activity. In this review paper, we highlight the importance of the KRAS/YB‑1 cascade in the response of KRAS-mutated solid tumors to CRT. Likewise, the opportunities to interfere with this pathway to improve CRT outcome are discussed in light of the current literature.

Defactinib, Pembrolizumab, and Gemcitabine in Patients with Advanced Treatment Refractory Pancreatic Cancer: A Phase I Dose Escalation and Expansion Study

PURPOSE

Targeting focal adhesion kinase (FAK) renders checkpoint immunotherapy effective in pancreatic ductal adenocarcinoma (PDAC) mouse model. Defactinib is a highly potent oral FAK inhibitor that has a tolerable safety profile.

PATIENTS AND METHODS

We conducted a multicenter, open-label, phase I study with dose escalation and expansion phases. In dose escalation, patients with refractory solid tumors were treated at five escalating dose levels of defactinib and gemcitabine to identify a recommended phase II dose (RP2D). In expansion phase, patients with metastatic PDAC who progressed on frontline treatment (refractory cohort) or had stable disease (SD) after at least 4 months of standard gemcitabine/nab-paclitaxel (maintenance cohort) were treated at RP2D. Pre- and posttreatment tumor biopsies were performed to evaluate tumor immunity.

RESULTS

The triple drug combination was well-tolerated, with no dose-limiting toxicities. Among 20 treated patients with refractory PDAC, the disease control rate (DCR) was 80%, with one partial response (PR) and 15 SDs, and the median progression-free survival (PFS) and overall survival (OS) were 3.6 and 7.8 months, respectively. Among 10 evaluable patients in the maintenance cohort, DCR was 70% with one PR and six SDs. Three patients with SD came off study due to treatment- or disease-related complications. The median PFS and OS on study treatment were 5.0 and 8.3 months, respectively.

CONCLUSIONS

The combination of defactinib, pembrolizumab, and gemcitabine was well-tolerated and safe, had promising preliminary efficacy, and showed biomarker activity in infiltrative T lymphocytes. Efficacy of this strategy may require incorporation of more potent chemotherapy in future studies.

Stromal Reprogramming by FAK Inhibition Overcomes Radiation Resistance to Allow for Immune Priming and Response to Checkpoint Blockade

The effects of radiotherapy (RT) on tumor immunity in pancreatic ductal adenocarcinoma (PDAC) are not well understood. To better understand if RT can prime antigen-specific T-cell responses, we analyzed human PDAC tissues and mouse models. In both settings, there was little evidence of RT-induced T-cell priming. Using in vitro systems, we found that tumor-stromal components, including fibroblasts and collagen, cooperate to blunt RT efficacy and impair RT-induced interferon signaling. Focal adhesion kinase (FAK) inhibition rescued RT efficacy in vitro and in vivo, leading to tumor regression, T-cell priming, and enhanced long-term survival in PDAC mouse models. Based on these data, we initiated a clinical trial of defactinib in combination with stereotactic body RT in patients with PDAC (NCT04331041). Analysis of PDAC tissues from these patients showed stromal reprogramming mirroring our findings in genetically engineered mouse models. Finally, the addition of checkpoint immunotherapy to RT and FAK inhibition in animal models led to complete tumor regression and long-term survival.

SIGNIFICANCE

Checkpoint immunotherapeutics have not been effective in PDAC, even when combined with RT. One possible explanation is that RT fails to prime T-cell responses in PDAC. Here, we show that FAK inhibition allows RT to prime tumor immunity and unlock responsiveness to checkpoint immunotherapy. This article is highlighted in the In This Issue feature, p. 2711.

Functional and clinical characteristics of focal adhesion kinases in cancer progression

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase and an adaptor protein that primarily regulates adhesion signaling and cell migration. FAK promotes cell survival in response to stress. Increasing evidence has shown that at the pathological level, FAK is highly expressed in multiple tumors in several systems (including lung, liver, gastric, and colorectal cancers) and correlates with tumor aggressiveness and patient prognosis. At the molecular level, FAK promotes tumor progression mainly by altering survival signals, invasive capacity, epithelial-mesenchymal transition, the tumor microenvironment, the Warburg effect, and stemness of tumor cells. Many effective drugs have been developed based on the comprehensive role of FAK in tumor cells. In addition, its potential as a tumor marker cannot be ignored. Here, we discuss the pathological and pre-clinical evidence of the role of FAK in cancer development; we hope that these findings will assist in FAK-based clinical studies.

Applications of CRISPR/Cas technology against drug-resistant lung cancers: an update

Out of all the cancer types, the most prevalent one is lung cancer. Multiple genes and signaling pathways play role in the progression of lung cancer. Considering the wider prevalence and fatality of lung cancer it has become the focus of current cancer research. Though currently used approaches have shown positive results against lung cancer but success against non-small cell lung cancer (NSCLC) still looms as an enigma for the entire research fraternity. The development of resistance against inhibitors within a short span is one of the reasons responsible for the failure and relapse of lung cancer. Under these prevailing conditions genome/gene-editing technology using clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR associated proteins (Cas), popularly known as CRISPR/Cas technology offers a convenient and flexible method for inducing precise changes within the lung cancer cell. Additionally, CRISPR-barcoding and CRISPR knockout screens at the genome-wide level can help in the functional investigation of specific mutations and identification of novel cancer drivers respectively. Several variants of the CRISPR/Cas system are being developed to limit off-targeting with enhanced precision. The present review article updates the usefulness of CRISPR/Cas technology against various types of lung cancers.

Knockdown of NDUFC1 inhibits cell proliferation, migration, and invasion of hepatocellular carcinoma

Background

NADH: ubiquinone oxidoreductase subunit C1(NDUFC1) encodes a subunit of the Complex I, which may support the structural stability of Complex I and assist in its biogenesis. The expression and functional roles of NDUFC1 in hepatocellular carcinoma (HCC) remain unknown.

Result

We knocked down the expression of NDUFC1 in HCC cell lines to explore the effects of NDUFC1 downregulation on HCC in vitro. MTT assay determined that downregulation of NDUFC1 significantly inhibited cell proliferation. Flow cytometry with (propidium iodide) PI staining indicated silencing of NDUFC1 arrested cell cycle of BEL-7404 cells at G2 phase and SK-HEP-1 cells at S/G2 phase. Annexin V-PI double staining and flow cytometric analysis showed that the downregulation of NDUFC1 significantly increased the population of apoptotic cells. Wound-healing assay and transwell assay indicated that the downregulation of NDUFC1 suppressed the migration and invasion of HCC cells. According to the detection of complex1 activity, we found that the activity of NDUFC1 silenced group decreased, whereas the content of ROS increased. Furthermore, combined with bioinformatics analysis of senescence-related genes, we found that the silence of NDUFC1 in HCC could induce senescence and inhibit autophagy. In addition, NDUFC1 could correlate positively with cancer-related pathways, among which the p53 pathways and the PI3K/Akt/mTOR pathways. Finally, NDUFC1 is high expression in HCC specimens. High NDUFC1 expression was associated with poor prognosis and was an independent risk factor for reduced overall survival (OS).

Conclusions

Our study indicated, for the first time, that NDUFC1 is an independent risk factor for the poor prognosis of HCC patients. NDUFC1 may promote tumor progression by inhibiting mitochondrial Complex I and up-regulating ROS through multiple cancer-related and senescence-related pathways of HCC, including p53 pathways and PI3K/Akt/mTOR pathways. We suppose that NDUFC1 might be a potential target for the mitochondrial metabolism therapy of HCC.

Focal adhesion kinase priming in pancreatic cancer, altering biomechanics to improve chemotherapy

The dense desmoplastic and fibrotic stroma is a characteristic feature of pancreatic ductal adenocarcinoma (PDAC), regulating disease progression, metastasis and response to treatment. Reciprocal interactions between the tumour and stroma are mediated by bidirectional integrin-mediated signalling, in particular by Focal Adhesion Kinase (FAK). FAK is often hyperactivated and overexpressed in aggressive cancers, promoting stromal remodelling and inducing tissue stiffness which can accelerate cancer cell proliferation, survival and chemoresistance. Therapeutic targeting of the PDAC stroma is an evolving area of interest for pre-clinical and clinical research, where a subtle reshaping of the stromal architecture prior to chemotherapy may prove promising in the clinical management of disease and overall patient survival. Here, we describe how transient stromal manipulation (or ‘priming’) via short-term FAK inhibition, rather than chronic treatment, can render PDAC cells exquisitely vulnerable to subsequent standard-of-care chemotherapy. We assess how our priming publication fits with the recent literature and describe in this perspective how this could impact future cancer treatment. This highlights the significance of treatment timing and warrants further consideration of anti-fibrotic therapies in the clinical management of PDAC and other fibrotic diseases.

Interplay of Developmental Hippo-Notch Signaling Pathways with the DNA Damage Response in Prostate Cancer

Prostate cancer belongs in the class of hormone-dependent cancers, representing a major cause of cancer incidence in men worldwide. Since upon disease onset almost all prostate cancers are androgen-dependent and require active androgen receptor (AR) signaling for their survival, the primary treatment approach has for decades relied on inhibition of the AR pathway via androgen deprivation therapy (ADT). However, following this line of treatment, cancer cell pools often become resistant to therapy, contributing to disease progression towards the significantly more aggressive castration-resistant prostate cancer (CRPC) form, characterized by poor prognosis. It is, therefore, of critical importance to elucidate the molecular mechanisms and signaling pathways underlying the progression of early-stage prostate cancer towards CRPC. In this review, we aim to shed light on the role of major signaling pathways including the DNA damage response (DDR) and the developmental Hippo and Notch pathways in prostate tumorigenesis. We recapitulate key evidence demonstrating the crosstalk of those pathways as well as with pivotal prostate cancer-related 'hubs' such as AR signaling, and evaluate the clinical impact of those interactions. Moreover, we attempt to identify molecules of the complex DDR-Hippo-Notch interplay comprising potentially novel therapeutic targets in the battle against prostate tumorigenesis.

Targeting KRAS mutant cancers: from druggable therapy to drug resistance

Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) is the most frequently mutated oncogene, occurring in a variety of tumor types. Targeting KRAS mutations with drugs is challenging because KRAS is considered undruggable due to the lack of classic drug binding sites. Over the past 40 years, great efforts have been made to explore routes for indirect targeting of KRAS mutant cancers, including KRAS expression, processing, upstream regulators, or downstream effectors. With the advent of KRAS (G12C) inhibitors, KRAS mutations are now druggable. Despite such inhibitors showing remarkable clinical responses, resistance to monotherapy of KRAS inhibitors is eventually developed. Significant progress has been made in understanding the mechanisms of drug resistance to KRAS-mutant inhibitors. Here we review the most recent advances in therapeutic approaches and resistance mechanisms targeting KRAS mutations and discuss opportunities for combination therapy.

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.

Genome editing and cancer: How far has research moved forward on CRISPR/Cas9?

Cancer accounted for almost ten million deaths worldwide in 2020. Metastasis, characterized by cancer cell invasion to other parts of the body, is the main cause of cancer morbidity and mortality. Therefore, understanding the molecular mechanisms of tumor formation and discovery of potential drug targets are of great importance. Gene editing techniques can be used to find novel drug targets and study molecular mechanisms. In this review, we describe how popular gene-editing methods such as CRISPR/Cas9, TALEN and ZFNs work, and, by comparing them, we demonstrate that CRISPR/Cas9 has superior efficiency and precision. We further provide an overview of the recent applications of CRISPR/Cas9 to cancer research, focusing on the most common cancers such as breast cancer, lung cancer, colorectal cancer, and prostate cancer. We describe how these applications will shape future research and treatment of cancer, and propose new ways to overcome current challenges.

NEDD9 Restrains dsDNA Damage Response during Non-Small Cell Lung Cancer (NSCLC) Progression

DNA damaging modalities are the backbone of treatments for non-small cell lung cancer (NSCLC). Alterations in DNA damage response (DDR) in tumor cells commonly contribute to emerging resistance to platinating agents, other targeted therapies, and radiation. The goal of this study is to identify the previously unreported role of NEDD9 scaffolding protein in controlling DDR processes and sensitivity to DNA damaging therapies. Using a siRNA-mediated approach to deplete NEDD9 in a group of human and murine KRAS/TP53-mutant NSCLC cell lines, coupled with a set of cell viability and clonogenic assays, flow cytometry analysis, and Western blotting, we evaluated the effects of NEDD9 silencing on cellular proliferation, DDR and epithelial-to-mesenchymal transition (EMT) signaling, cell cycle, and sensitivity to cisplatin and UV irradiation. Using publicly available NSCLC datasets (TCGA) and an independent cohort of primary NSCLC tumors, subsequent in silico and immunohistochemical (IHC) analyses were performed to assess relevant changes in NEDD9 RNA and protein expression across different stages of NSCLC. The results of our study demonstrate that NEDD9 depletion is associated with the increased tumorigenic capacity of NSCLC cells. These phenotypes were accompanied by significantly upregulated ATM-CHK2 signaling, shifting towards a more mesenchymal phenotype in NEDD9 depleted cells and elevated sensitivity to UV-irradiation. IHC analyses revealed an association between reduced NEDD9 protein expression and a decrease in overall (OS) and progression-free survival (PFS) of the NSCLC patients. These data, for the first time, identified NEDD9 as a negative regulator of ATM kinase activity and related DDR signaling in numerous KRAS/TP53 mutated NSCLC, with its effects on the regulation of DDR-dependent EMT signaling, sensitivity to DNA damaging modalities in tumor cells, and the survival of the patients.

Vector engineering, strategies and targets in cancer gene therapy

Understanding the molecular basis of disease and the design of rationally designed molecular therapies has been the holy grail in the management of human cancers. Gene-based therapies are an important avenue for achieving a possible cure. Focused research in the last three decades has provided significant clues to optimize the potential of cancer gene therapy. The development of gene therapies with a high potential to kill the target cells at the lowest effective dose possible, the development of vectors with significant ability to target cancer-associated antigen, the application of adjunct therapies to target dysregulated microRNA, and embracing a hybrid strategy with a combination of gene therapy and low-dose chemotherapy in a disease-specific manner will be pivotal. This article outlines the advances and challenges in the field with emphasis on the biology and scope of vectors used for gene transfer, newer targets identified, and their outcome in preclinical and clinical studies.

Targeting Mutant Kirsten Rat Sarcoma Viral Oncogene Homolog in Non-Small Cell Lung Cancer: Current Difficulties, Integrative Treatments and Future Perspectives

In the past few decades, several gene mutations, including the anaplastic lymphoma kinase, epidermal growth factor receptor, ROS proto-oncogene 1 and rat sarcoma viral oncogene homolog (RAS), have been discovered in non-small cell lung cancer (NSCLC). Kirsten rat sarcoma viral oncogene homolog (KRAS) is the isoform most frequently altered in RAS-mutated NSCLC cases. Due to the structural and biochemical characteristics of the KRAS protein, effective approaches to treating KRAS-mutant NSCLC still remain elusive. Extensive recent research on KRAS-mutant inhibitors has made a breakthrough in identifying the covalent KRASG12C inhibitor as an effective agent for the treatment of NSCLC. This review mainly concentrated on introducing new covalent KRASG12C inhibitors like sotorasib (AMG 510) and adagrasib (MRTX 849); summarizing inhibitors targeting the KRAS-related upstream and downstream effectors in RAF/MEK/ERK pathway and PI3K/AKT/mTOR pathway; exploring the efficacy of immunotherapy and certain emerging immune-related therapeutics such as adoptive cell therapy and cancer vaccines. These inhibitors are being investigated in clinical trials and have exhibited promising effects. On the other hand, naturally extracted compounds, which have exhibited safe and effective properties in treating KRAS-mutant NSCLC through suppressing the MAPK and PI3K/AKT/mTOR signaling pathways, as well as through decreasing PD-L1 expression in preclinical studies, could be expected to enter into clinical studies. Finally, in order to confront the matter of drug resistance, the ongoing clinical trials in combination treatment strategies were summarized herein.

FAK in Cancer: From Mechanisms to Therapeutic Strategies

Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, is overexpressed and activated in many cancer types. FAK regulates diverse cellular processes, including growth factor signaling, cell cycle progression, cell survival, cell motility, angiogenesis, and the establishment of immunosuppressive tumor microenvironments through kinase-dependent and kinase-independent scaffolding functions in the cytoplasm and nucleus. Mounting evidence has indicated that targeting FAK, either alone or in combination with other agents, may represent a promising therapeutic strategy for various cancers. In this review, we summarize the mechanisms underlying FAK-mediated signaling networks during tumor development. We also summarize the recent progress of FAK-targeted small-molecule compounds for anticancer activity from preclinical and clinical evidence.

CRISPR/Cas9: A revolutionary genome editing tool for human cancers treatment

Cancer is a genetic disease stemming from genetic and epigenetic mutations and is the second most common cause of death across the globe. Clustered regularly interspaced short palindromic repeats (CRISPR) is an emerging gene-editing tool, acting as a defense system in bacteria and archaea. CRISPR/Cas9 technology holds immense potential in cancer diagnosis and treatment and has been utilized to develop cancer disease models such as medulloblastoma and glioblastoma mice models. In diagnostics, CRISPR can be used to quickly and efficiently detect genes involved in various cancer development, proliferation, metastasis, and drug resistance. CRISPR/Cas9 mediated cancer immunotherapy is a well-known treatment option after surgery, chemotherapy, and radiation therapy. It has marked a turning point in cancer treatment. However, despite its advantages and tremendous potential, there are many challenges such as off-target effects, editing efficiency of CRISPR/Cas9, efficient delivery of CRISPR/Cas9 components into the target cells and tissues, and low efficiency of HDR, which are some of the main issues and need further research and development for completely clinical application of this novel gene editing tool. Here, we present a CRISPR/Cas9 mediated cancer treatment method, its role and applications in various cancer treatments, its challenges, and possible solution to counter these challenges.

Research Progress, Challenges, and Breakthroughs of Organoids as Disease Models

Traditional cell lines and xenograft models have been widely recognized and used in research. As a new research model, organoids have made significant progress and development in the past 10 years. Compared with traditional models, organoids have more advantages and have been applied in cancer research, genetic diseases, infectious diseases, and regenerative medicine. This review presented the advantages and disadvantages of organoids in physiological development, pathological mechanism, drug screening, and organ transplantation. Further, this review summarized the current situation of vascularization, immune microenvironment, and hydrogel, which are the main influencing factors of organoids, and pointed out the future directions of development.

Resistance looms for KRAS G12C inhibitors and rational tackling strategies

KRAS mutations are one of the most frequent activating alterations in carcinoma. Recent efforts have witnessed a revolutionary strategy for KRAS G12C inhibitors with exhibiting conspicuous clinical responses across multiple tumor types, providing new impetus for renewed drug development and culminating in sotorasib with approximately 6-month median progression-free survival in KRAS G12C-driven lung cancer. However, diverse genomic and histological mechanisms conferring resistance to KRAS G12C inhibitors may limit their clinical efficacy. Herein, we first briefly discuss the recent resistance looms for KRAS G12C inhibitors, focusing on their clinical trials. We then comprehensively interrogate and underscore our current understanding of resistance mechanisms and the necessity of incorporating genomic analyses into the clinical investigation to further decipher resistance mechanisms. Finally, we highlight the future role of novel treatment strategies especially rational identification of targeted combinatorial approaches in tackling drug resistance, and propose our views on including the application of robust biomarkers to precisely guide combination medication regimens.

FAK-targeting PROTAC demonstrates enhanced antitumor activity against KRAS mutant non-small cell lung cancer

Focal adhesion kinase (FAK) has been established as a promising therapeutic target for KRAS mutant non-small cell lung cancer (NSCLC). However, phase II clinical trials of a FAK inhibitor (Defactinib) have only shown modest antitumor activity. To address this challenge, here we report the use of a FAK-targeting proteolysis targeting chimera (D-PROTAC) to treat KRAS mutant NSCLC. We validated that D-PROTAC could efficiently eliminate FAK protein via the ubiquitin-proteasome pathway in KRAS mutant NSCLC A427 cells, causing over 90% degradation at 800 nM. After comparing both in vitro and in vivo therapeutic efficacies, we demonstrated that D-PRTOAC outperformed Defactinib in inhibiting tumor growth. Specifically, D-PROTAC at 800 nM reduced cell viability, migration, and invasion by ∼80%. Furthermore, a ∼85% suppression of tumor growth was elicited by D-PROTAC when intratumorally administrated at 10 mg/kg in subcutaneous A427-bearing mice. These results thus demonstrate for the first time that PROTACs may serve as promising therapeutic agents for the intractable NSCLC harboring KRAS mutations.

Application of the CRISPR/Cas9-based gene editing technique in basic research, diagnosis, and therapy of cancer

The 2020 Nobel Prize in Chemistry was awarded to Emmanuelle Charpentier and Jennifer Doudna for the development of the Clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease9 (CRISPR/Cas9) gene editing technology that provided new tools for precise gene editing. It is possible to target any genomic locus virtually using only a complex nuclease protein with short RNA as a site-specific endonuclease. Since cancer is caused by genomic changes in tumor cells, CRISPR/Cas9 can be used in the field of cancer research to edit genomes for exploration of the mechanisms of tumorigenesis and development. In recent years, the CRISPR/Cas9 system has been increasingly used in cancer research and treatment and remarkable results have been achieved. In this review, we introduced the mechanism and development of the CRISPR/Cas9-based gene editing system. Furthermore, we summarized current applications of this technique for basic research, diagnosis and therapy of cancer. Moreover, the potential applications of CRISPR/Cas9 in new emerging hotspots of oncology research were discussed, and the challenges and future directions were highlighted.

Focal Adhesion Kinase (FAK) Inhibition Synergizes with KRAS G12C Inhibitors in Treating Cancer through the Regulation of the FAK-YAP Signaling

KRAS mutation is one of the most prevalent genetic drivers of cancer development, yet KRAS mutations are until very recently considered undruggable. There are ongoing trials of drugs that target the KRAS G12C mutation, yet acquired drug resistance from the extended use has already become a major concern. Here, it is demonstrated that KRAS G12C inhibition induces sustained activation of focal adhesive kinase (FAK) and show that a combination therapy comprising KRAS G12C inhibition and a FAK inhibitor (IN10018) achieves synergistic anticancer effects. It can simultaneously reduce the extent of drug resistance. Diverse CDX and PDX models of KRAS G12C mutant cancer are examined and synergistic benefits from the combination therapy are consistently observed. Mechanistically, it is found that both aberrant FAK-YAP signaling and FAK-related fibrogenesis impact on the development of KRAS G12C inhibitor resistance. This study thus illustrates the mechanism of resistance of cancer to the treatment of KRAS G12C inhibitor, as well as an innovative combination therapy to improve treatment outcomes for KRAS G12C mutant cancers.

Piperlongumine inhibits migration and proliferation of castration-resistant prostate cancer cells via triggering persistent DNA damage

BACKGROUND

Metastatic castration-resistant prostate cancer (CRPC) is the leading cause of death among men diagnosed with prostate cancer. Piperlongumine (PL) is a novel potential anticancer agent that has been demonstrated to exhibit anticancer efficacy against prostate cancer cells. However, the effects of PL on DNA damage and repair against CRPC have remained unclear. The aim of this study was to further explore the anticancer activity and mechanisms of action of PL against CRPC in terms of DNA damage and repair processes.

METHODS

The effect of PL on CRPC was evaluated by MTT assay, long-term cell proliferation, reactive oxygen species assay, western blot assay, flow cytometry assay (annexin V/PI staining), β-gal staining assay and DAPI staining assay. The capacity of PL to inhibit the invasion and migration of CRPC cells was assessed by scratch-wound assay, cell adhesion assay, transwell assay and immunofluorescence (IF) assay. The effect of PL on DNA damage and repair was determined via IF assay and comet assay.

RESULTS

The results showed that PL exhibited stronger anticancer activity against CRPC compared to that of taxol, cisplatin (DDP), doxorubicin (Dox), or 5-Fluorouracil (5-FU), with fewer side effects in normal cells. Importantly, PL treatment significantly decreased cell adhesion to the extracellular matrix and inhibited the migration of CRPC cells through affecting the expression and distribution of focal adhesion kinase (FAK), leading to concentration-dependent inhibition of CRPC cell proliferation and concomitantly increased cell death. Moreover, PL treatment triggered persistent DNA damage and provoked strong DNA damage responses in CRPC cells.

CONCLUSION

Collectively, our findings demonstrate that PL potently inhibited proliferation, migration, and invasion of CRPC cells and that these potent anticancer effects were potentially achieved via triggering persistent DNA damage in CRPC cells.

Targeting FAK in anticancer combination therapies

Focal adhesion kinase (FAK) is both a non-receptor tyrosine kinase and an adaptor protein that primarily regulates adhesion signalling and cell migration, but FAK can also promote cell survival in response to stress. FAK is commonly overexpressed in cancer and is considered a high-value druggable target, with multiple FAK inhibitors currently in development. Evidence suggests that in the clinical setting, FAK targeting will be most effective in combination with other agents so as to reverse failure of chemotherapies or targeted therapies and enhance efficacy of immune-based treatments of solid tumours. Here, we discuss the recent preclinical evidence that implicates FAK in anticancer therapeutic resistance, leading to the view that FAK inhibitors will have their greatest utility as combination therapies in selected patient populations.

Will CRISPR-Cas9 Have Cards to Play Against Cancer? An Update on its Applications

Genome editing employs targeted nucleases as powerful tools to precisely alter the genome of target cells and regulate functional genes. Various strategies have been risen so far as the molecular scissors-mediated genome editing that includes zinc finger nuclease, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats-CRISPR-related protein 9. These tools allow researchers to understand the basics of manipulating the genome, create animal models to study human diseases, understand host-pathogen interactions and design disease targets. Targeted genome modification utilizing RNA-guided nucleases are of recent curiosity, as it is a fast and effective strategy that enables the researchers to manipulate the gene of interest, carry out functional studies, understand the molecular basis of the disease and design targeted therapies. CRISPR-Cas9, a bacterial defense system employed against viruses, consists of a single-strand RNA-guided Cas9 nuclease connected to the corresponding complementary target sequence. This powerful and versatile tool has gained tremendous attention among the researchers, owing to its ability to correct genetic disorders. To help illustrate the potential of this gene editor in unexplored corners of oncology, we describe the history of CRISPR-Cas9, its rapid progression in cancer research as well as future perspectives.

Inhibition of focal adhesion kinase enhances antitumor response of radiation therapy in pancreatic cancer through CD8+ T cells

Objective:

Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy, due in large part to its resistance to conventional therapies, including radiotherapy (RT). Despite RT exerting a modest antitumor response, it has also been shown to promote an immunosuppressive tumor microenvironment. Previous studies demonstrated that focal adhesion kinase inhibitors (FAKi) in clinical development inhibit the infiltration of suppressive myeloid cells and T regulatory (T regs) cells, and subsequently enhance effector T cell infiltration. FAK inhibitors in clinical development have not been investigated in combination with RT in preclinical murine models or clinical studies. Thus, we investigated the impact of FAK inhibition on RT, its potential as an RT sensitizer and immunomodulator in a murine model of PDAC.

Methods:

We used a syngeneic orthotopic murine model to study the effect of FAKi on hypofractionated RT.

Results:

In this study we showed that IN10018, a small molecular FAKi, enhanced antitumor response to RT. Antitumor activity of the combination of FAKi and RT is T cell dependent. FAKi in combination with RT enhanced CD8+ T cell infiltration significantly in comparison to the radiation or FAKi treatment alone (P < 0.05). FAKi in combination with radiation inhibited the infiltration of granulocytes but enhanced the infiltration of macrophages and T regs in comparison with the radiation or FAKi treatment alone (P < 0.01).

Conclusions:

These results support the clinical development of FAKi as a radiosensitizer for PDAC and combining FAKi with RT to prime the tumor microenvironment of PDAC for immunotherapy.

Delivery of genome-editing biomacromolecules for treatment of lung genetic disorders

Genome-editing systems based on clustered, regularly interspaced, short palindromic repeat (CRISPR)/associated protein (CRISPR/Cas), are emerging as a revolutionary technology for the treatment of various genetic diseases. To date, the delivery of genome-editing biomacromolecules by viral or non-viral vectors have been proposed as new therapeutic options for lung genetic disorders, such as cystic fibrosis (CF) and α-1 antitrypsin deficiency (AATD), and it has been accepted that these delivery vectors can introduce CRISPR/Cas9 machineries into target cells or tissues in vitro, ex vivo and in vivo. However, the efficient local or systemic delivery of CRISPR/Cas9 elements to the lung, enabled by either viral or by non-viral carriers, still remains elusive. Herein, we first introduce lung genetic disorders and their current treatment options, and then summarize CRISPR/Cas9-based strategies for the therapeutic genome editing of these disorders. We further summarize the pros and cons of different routes of administration for lung genetic disorders. In particular, the potentials of aerosol delivery for therapeutic CRISPR/Cas9 biomacromolecules for lung genome editing are discussed and highlighted. Finally, current challenges and future outlooks in this emerging area are briefly discussed.

G9a Promotes Invasion and Metastasis of Non-Small Cell Lung Cancer through Enhancing Focal Adhesion Kinase Activation via NF-κB Signaling Pathway

Potential roles of euchromatic histone methyltransferase 2 (EHMT2 or G9a) in invasion and metastasis are not well understood in non-small cell lung cancer (NSCLC). Here, we investigated the effect and underlying mechanisms of G9a and therapeutic implications of targeting G9a in the invasion and metastasis of NSCLC. Overexpression of G9a significantly enhanced in vitro proliferation and invasion, while knockdown of G9a drastically suppressed in vivo growth and metastasis of A549 and H1299 NSCLC cells. Knockdown or inhibition of G9a significantly decreased the expression of focal adhesion kinase (FAK) protein and activation of FAK pathway. In addition, defactinib, a potent FAK inhibitor, partially abolished the G9a-enhanced invasion in these NSCLC cells. Furthermore, targeting G9a was found to suppress NF-κB transcriptional activity in NSCLC cells through stabilizing NF-κB inhibitor alpha (IκBα), while an NF-κB inhibitor Parthenilide partially abolished the G9a-enhanced FAK activation, which suggests that G9a-enhanced invasion and activation of FAK is mediated by elevated NF-κB activity. Notably, a strong positive correlation between the IHC staining of G9a and phosphorylated FAK proteins was identified in H1299 xenografts and 159 cases of NSCLC tissues (R = 0.408). IMPLICATIONS: The findings of this study strongly demonstrate that G9a may promote invasion and metastasis of NSCLC cells by enhancing FAK signaling pathway via elevating NF-κB transcriptional activity, indicating potential significance and therapeutic implications of these pathways in the invasion and metastasis of NSCLCs that overexpress G9a protein.

CRISPR-Cas deployment in non-small cell lung cancer for target screening, validations, and discoveries

Continued advancements in CRISPR-Cas systems have accelerated genome research. Use of CRISPR-Cas in cancer research has been of great interest that is resulting in development of orthogonal methods for drug target validations and discovery of new therapeutic targets through genome-wide screens of cancer cells. CRISPR-based screens have also revealed several new cancer drivers through alterations in tumor suppressor genes (TSGs) and oncogenes inducing resistance to targeted therapies via activation of alternate signaling pathways. Given such dynamic status of cancer, we review the application of CRISPR-Cas in non-small cell lung cancer (NSCLC) for development of mutant models, drug screening, target validation, novel target discoveries, and other emerging potential applications. In addition, CRISPR-based approach for development of novel anticancer combination therapies is also discussed in this review.

Focal adhesion kinase: Insight into its roles and therapeutic potential in oesophageal cancer

Oesophageal cancer is associated with high morbidity and mortality rates because it is highly invasive and prone to recurrence and metastasis, with a five-year survival rate of <20%. Therefore, there is an urgent need for new methods aimed at improving therapeutic intervention. Several studies have shown that targeted therapy may be effective for the treatment of oesophageal cancer. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase with kinase activity and scaffolding function, could be overexpressed in a variety of solid tumours, including oesophageal cancer. FAK participates in survival, proliferation, progression, adhesion, invasion, migration, epithelial-to-mesenchymal transition, angiogenesis, DNA damage repair, and other biological processes through multiple signalling pathways in cancer cells. It plays an important role in the occurrence and development of tumours and has been linked to the prognosis of oesophageal cancer. FAK has been suggested as a potential therapeutic target in oesophageal cancer; thus, the combination of FAK inhibitors with chemotherapy, radiotherapy, and immunotherapy is expected to prolong the survival of patients. This paper presents a brief overview of the structure of FAK and its potential role in oesophageal cancer, providing a rationale for the future application of FAK inhibitors in the treatment of the disease.

KRAS oncogene may be another target conquered in non-small cell lung cancer (NSCLC)

Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the most common mutant oncogenes in non‐small cell lung cancer (NSCLC). The survival of patients with KRAS mutations may be much lower than patients without KRAS mutations. However, due to the complex structure and diverse biological properties, it is difficult to achieve specific inhibitors for the direct elimination of KRAS activity, making KRAS a challenging therapeutic target. At present, with the tireless efforts of medical research, including KRAS G12C inhibitors, immunotherapy and other combination strategies, this dilemma is expected to an end. In addition, inhibition of the downstream signaling pathways of KRAS may be a promising combination strategy. Given the rapid development of treatments, understanding the details will be important to determine the individualized treatment options, including combination therapy and potential resistance mechanisms.

The survival of patients with KRAS mutations may be much lower than patients without KRAS mutations. At present, with the tireless efforts of medical research, including KRAS G12C inhibitors, immunotherapy and other combination strategy, this dilemma of KRAS mutated NSCLC is expected to an end.

Patient-derived cell line, xenograft and organoid models in lung cancer therapy

Lung cancer accounts for most cancer-related deaths worldwide and has an overall 5-year survival rate of ~15%. Cell lines have played important roles in the study of cancer biology and potential therapeutic targets, as well as pre-clinical testing of novel drugs. However, most experimental therapies that have cleared preclinical testing using established cell lines have failed phase III clinical trials. This suggests that such models may not adequately recapitulate patient tumor biology and clinical outcome predictions. Here, we discuss and compare different pre-clinical lung cancer models, including established cell lines, patient-derived cell lines, xenografts and organoids, summarize the methodology for generating these models, and review their relative advantages and limitations in different oncologic research applications. We further discuss additional gaps in patient-derived pre-clinical models to better recapitulate tumor biology and improve their clinical predictive power.

FAK inhibition radiosensitizes pancreatic ductal adenocarcinoma cells in vitro

Introduction

Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase protein frequently overexpressed in cancer and has been linked to an increase in the stem cell population of tumors, resistance to therapy, and metastatic spread. Pharmacological FAK inhibition in pancreatic cancer has received increased attention over the last few years, either alone or in combination with other therapeutics including chemotherapy and immunotherapy. However, its prognostic value and its role in radioresistance of pancreatic ducal adenocarcinoma (PDAC) is unknown.

Methods and materials

Using the TCGA and GTEx databases, we investigated the genetic alterations and mRNA expression levels of PTK2 (the encoding-gene for FAK) in normal pancreatic tissue and pancreatic cancer and its impact on patient survival. Furthermore, we evaluated the expression of FAK and its tyrosine domain Ty-397 in three pancreatic cancer cell lines. We went further and evaluated the role of a commercial FAK tyrosine kinase inhibitor VS-4718 on the viability and radiosensitization of the pancreatic cell lines as well as its effect on the extracellular matrix (ECM) production from the pancreatic stellate cells. Furthermore, we tested the effect of combining radiation with VS-4718 in a three-dimensional (3D) multicellular pancreatic tumor spheroid model.

Results

A database analysis revealed a relevant increase in genetic alterations and mRNA expression of the PTK2 in PDAC, which were associated with lower progression-free survival. In vitro, there was only variation in the basal phosphorylation level of FAK in cell lines. VS-4718 radiosensitized pancreatic cell lines only in the presence of ECM-producing pancreatic stellate cells and markedly reduced the ECM production in the stromal cells. Finally, using a 3D multicellular tumor model, the combination of VS-4718 and radiotherapy significantly reduced the growth of tumor aggregates.

Conclusion

Pharmacological inhibition of FAK in pancreatic cancer could be a novel therapeutic strategy as our results show a radiosensitization effect of VS-4718 in vitro in a multicellular 2D- and in a 3D-model of pancreatic cancer.

Electronic supplementary material

The online version of this article (10.1007/s00066-020-01666-0) contains supplementary material, which is available to authorized users.

Discovery of 7H-pyrrolo[2,3-d]pyridine derivatives as potent FAK inhibitors: Design, synthesis, biological evaluation and molecular docking study

Focal adhesion kinase (FAK) is an intracellular non-receptor tyrosine kinase responsible for development of various tumor types. Aiming to explore new potent inhibitors, two series of 2,4-disubstituted-7H-pyrrolo[2,3-d]pyrimidine derivatives were designed and synthesized on the base of structure-based design strategy. Biological evaluation indicated that most of these new compounds could potently inhibit FAK kinase, leading to the promising inhibitors against the proliferation of U-87MG, A-549, and MDA-MB-231 cancer cell lines. Among them, the optimized compound 18h potently inhibited the enzyme (IC₅₀ = 19.1 nM) and displayed stronger potency than TAE-226 in U-87MG, A-549 and MDA-MB-231 cells, with IC₅₀ values of 0.35, 0.24, and 0.34 μM, respectively. Compound 18h is a multi-target kinase inhibitor. Furthermore, compound 18h also exhibited relatively less cytotoxicity (IC₅₀ = 3.72 μM) toward a normal human cell line, HK2. According to the flow cytometry and wound healing assay results, compound 18h effectively induced apoptosis and G0/G1 phase arrest of MDA-MB-231 cells and suppressed the migration of U-87MG, A-549 and MDA-MB-231 cells. The docking study of compound 18h was performed to elucidate its possible binding modes and to provide a structural basis for the further structural guidance design of FAK inhibitors. Collectively, these data support the further development of compound 18h as a lead compound for FAK-targeted anticancer drug discovery.

The Intermediate Filament Synemin Regulates Non-Homologous End Joining in an ATM-Dependent Manner

The treatment resistance of cancer cells is a multifaceted process in which DNA repair emerged as a potential therapeutic target. DNA repair is predominantly conducted by nuclear events; yet, how extra-nuclear cues impact the DNA damage response is largely unknown. Here, using a high-throughput RNAi-based screen in three-dimensionally-grown cell cultures of head and neck squamous cell carcinoma (HNSCC), we identified novel focal adhesion proteins controlling DNA repair, including the intermediate filament protein, synemin. We demonstrate that synemin critically regulates the DNA damage response by non-homologous end joining repair. Mechanistically, synemin forms a protein complex with DNA-PKcs through its C-terminal tail domain for determining DNA repair processes upstream of this enzyme in an ATM-dependent manner. Our study discovers a critical function of the intermediate filament protein, synemin in the DNA damage response, fundamentally supporting the concept of cytoarchitectural elements as co-regulators of nuclear events.

Phase 2 study of the focal adhesion kinase inhibitor defactinib (VS-6063) in previously treated advanced KRAS mutant non-small cell lung cancer

OBJECTIVES

KRAS mutations, which occur in approximately 25% of lung adenocarcinoma cases, represent a major unmet clinical need in thoracic oncology. Preclinical studies have demonstrated that KRAS mutant NSCLC cell lines and xenografts with additional alterations in either TP53 or CDKN2A (INK4A/ARF) loci are sensitive to focal adhesion kinase (FAK) inhibition. Defactinib (VS-6063) is a selective oral inhibitor of FAK.

MATERIALS AND METHODS

Patients with previously treated advanced KRAS mutant NSCLC were prospectively assigned to one of four molecularly defined cohorts based on the presence or absence of TP53 or CDKN2A alterations and received treatment with defactinib 400 mg orally BID until disease progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS) at 12 weeks.

RESULTS

Fifty-five patients were enrolled. Mean age was 62 years; 51% were female. The median number of prior lines of therapy was 4 (range 1-8). Fifteen (28%) patients met the 12-week PFS endpoint, with one patient achieving a partial response. Median PFS was 45 days. Clinical efficacy did not correlate with TP53 or CDKN2A status. The most common adverse events were fatigue, gastrointestinal, and increased bilirubin, and were generally grade 1 or 2 in severity.

CONCLUSION

In heavily pretreated patients with KRAS mutant NSCLC, defactinib monotherapy demonstrated modest clinical activity. Efficacy was not associated with TP53 and CDKN2A status. Defactinib was generally well tolerated.