Bosutinib inhibits migration and invasion via ACK1 in KRAS mutant non-small cell lung cancer. Mol Cancer. 2014;13:13. [PMID: 24461128 DOI: 10.1186/1476-4598-13-13]

Zebrafish in Lung Cancer Research

Zebrafish is increasingly used as a model organism for cancer research because of its genetic and physiological similarities to humans. Modeling lung cancer (LC) in zebrafish has received significant attention. This review focuses on the insights gained from using zebrafish in LC research. These insights range from investigating the genetic and molecular mechanisms that contribute to the development and progression of LC to identifying potential drug targets, testing the efficacy and toxicity of new therapies, and applying zebrafish for personalized medicine studies. This review provides a comprehensive overview of the current state of LC research performed using zebrafish, highlights the advantages and limitations of this model organism, and discusses future directions in the field.

Design, Synthesis, and Evaluation of (R)-8-((Tetrahydrofuran-2-yl)methyl)pyrido[2,3-d]pyrimidin-7-ones as Novel Selective ACK1 Inhibitors to Combat Acquired Resistance to the Third-Generation EGFR Inhibitor

Activated Cdc42-associated kinase 1 (ACK1) alterations have been considered to mediate bypass acquired resistance to the third-generation EGFR inhibitors (ASK120067 and osimertinib) in NSCLC. Despite many efforts to develop ACK1 small molecule inhibitors, no selective inhibitors have entered clinical trials. We used structure-based drug design to obtain a series of (R)-8-((tetrahydrofuran-2-yl)methyl)pyrido [2,3-d]pyrimidin-7-ones as novel selective ACK1 inhibitors. One of the representative compounds, 10zi, potently inhibited ACK1 kinase with an IC₅₀ of 2.1 nM, while sparing SRC kinase (IC₅₀ = 218.7 nM). Further, 10zi displayed good kinome selectivity in a profiling of 468 kinases. In the ASK120067-resistant lung cancer cell line (67R), 10zi dose-dependently inhibited the phosphorylation of ACK1 and downstream AKT pathway and showed a strong synergistic anti-tumor effect in combination with ASK120067 in vitro. Additionally, 10zi also exhibited reasonable PK profiles with an oral bioavailability of 19.8% at the dose of 10 mg/kg, which provided a promising lead for further development of new anticancer drugs.

FYN: emerging biological roles and potential therapeutic targets in cancer

Src family protein kinases (SFKs) play a key role in cell adhesion, invasion, proliferation, survival, apoptosis, and angiogenesis during tumor development. In humans, SFKs consists of eight family members with similar structure and function. There is a high level of overexpression or hyperactivity of SFKs in tumor, and they play an important role in multiple signaling pathways involved in tumorigenesis. FYN is a member of the SFKs that regulate normal cellular processes. Additionally, FYN is highly expressed in many cancers and promotes cancer growth and metastasis through diverse biological functions such as cell growth, apoptosis, and motility migration, as well as the development of drug resistance in many tumors. Moreover, FYN is involved in the regulation of multiple cancer-related signaling pathways, including interactions with ERK, COX-2, STAT5, MET and AKT. FYN is therefore an attractive therapeutic target for various tumor types, and suppressing FYN can improve the prognosis and prolong the life of patients. The purpose of this review is to provide an overview of FYN's structure, expression, upstream regulators, downstream substrate molecules, and biological functions in tumors.

Improvement of ACK1-targeted therapy efficacy in lung adenocarcinoma using chloroquine or bafilomycin A1

BACKGROUND

Activated Cdc42-associated kinase 1 (ACK1) is a promising druggable target for cancer, but its inhibitors only showed moderate effects in clinical trials. The study aimed to investigate the underlying mechanisms and improve the antitumor efficacy of ACK1 inhibitors.

METHODS

RNA-seq was performed to determine the downstream pathways of ACK. Using Lasso Cox regression analysis, we built a risk signature with ACK1-related autophagy genes in the lung adenocarcinoma (LUAD) patients from The Cancer Genome Atlas (TCGA) project. The performance of the signature in predicting the tumor immune environment and response to immunotherapy and chemotherapy were assessed in LUAD. CCK8, mRFP-GFP-LC3 assay, western blot, colony formation, wound healing, and transwell migration assays were conducted to evaluate the effects of the ACK1 inhibitor on lung cancer cells. A subcutaneous NSCLC xenograft model was used for in vivo study.

RESULTS

RNA-seq revealed the regulatory role of ACK1 in autophagy. Furthermore, the risk signature separated LUAD patients into low- and high-risk groups with significantly different prognoses. The two groups displayed different tumor immune environments regarding 28 immune cell subsets. The low-risk groups showed high immune scores, high CTLA4 expression levels, high immunophenoscore, and low DNA mismatch repair capacity, suggesting a better response to immunotherapy. This signature also predicted sensitivity to commonly used chemotherapy and targeted drugs. In vitro, the ACK1 inhibitors (AIM-100 and Dasatinib) appeared to trigger adaptive autophagy-like response to protect lung cancer cells from apoptosis and activated the AMPK/mTOR signaling pathway, partially explaining its moderate antitumor efficacy. However, blocking lysosomal degradation with chloroquine/Bafilamycine A1 or inhibiting AMPK signaling with compound C/shPRKAA1 enhanced the ACK1 inhibitor's cytotoxic effects on lung cancer cells. The efficacy of the combined therapy was also verified using a mouse xenograft model.

CONCLUSIONS

The resulting signature from ACK1-related autophagy genes robustly predicted survival and drug sensitivity in LUAD. The lysosomal degradation inhibition improved the therapeutic effects of the ACK1 inhibitor, suggesting a potential role for autophagy in therapy evasion.

Exploration of Novel Immunological Terms in Lung Cancer With Large Populations: Implications for Immunotherapy

Background

Ideal biomarkers to predict the response to immunotherapy in lung cancer are still lacking. Therefore, there is a need to explore effective biomarkers in large populations.

Objective

The objective of this study is to explore novel immunological classifications that are associated with immunotherapy response through the ssGSEA algorithm.

Methods

Six independent lung cancer cohorts were collected for analysis including The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and the EMBL-EBI database. The ssGSEA algorithm was performed to extract immune terms. Then, TCGA samples were involved as a training group and other cohorts were used as a validation group. After LASSO and Cox regression, prognostic associated immune terms were extracted and an immune-related risk score (IRS) signature was constructed. Furthermore, the association between IRS signature and clinical data, genome features, stemness indices analysis, tumor immune microenvironment, immunotherapy efficiency, and targeted therapy response was also investigated.

Results

A total of 1,997 samples were enrolled in this study including six large lung cancer cohorts. Fifty-four immune terms were calculated through the ssGSEA algorithm in combined cohorts. Then, a nine-immune-term risk score model named IRS signature was established to predict the prognosis in combined cohorts. We classified patients into high-risk and low-risk subgroups according to the cutoff point. Subsequently, analysis of clinical data and genome features indicated that the patients in the high-IRS group tend to have advanced clinical features (clinical stage and T classification), as well as a higher level of copy number variation burden, higher tumor burden mutation, and higher tumor stemness indices. Immune landscape analysis demonstrated that high-IRS groups exhibited lower immune cell infiltration and immune-suppressive state. More importantly, the predicted result of the Tumor Immune Dysfunction and Exclusion analysis showed that high-IRS groups might be more insensitive to immunotherapy. Meanwhile, we have also identified that high-IRS groups were associated with better efficiency of several targeted drugs.

Conclusion

To summarize, we identified a novel IRS model based on nine immune terms, which was quantified by the ssGSEA algorithm. This model had good efficacy in predicting overall survival and immunotherapy response in non-small cell lung cancer patients, which might be an underlying biomarker.

Cdc42/Rac Interactive Binding Containing Effector Proteins in Unicellular Protozoans With Reference to Human Host: Locks of the Rho Signaling

Small GTPases are the key to actin cytoskeleton signaling, which opens the lock of effector proteins to forward the signal downstream in several cellular pathways. Actin cytoskeleton assembly is associated with cell polarity, adhesion, movement and other functions in eukaryotic cells. Rho proteins, specifically Cdc42 and Rac, are the primary regulators of actin cytoskeleton dynamics in higher and lower eukaryotes. Effector proteins, present in an inactive state gets activated after binding to the GTP bound Cdc42/Rac to relay a signal downstream. Cdc42/Rac interactive binding (CRIB) motif is an essential conserved sequence found in effector proteins to interact with Cdc42 or Rac. A diverse range of Cdc42/Rac and their effector proteins have evolved from lower to higher eukaryotes. The present study has identified and further classified CRIB containing effector proteins in lower eukaryotes, focusing on parasitic protozoans causing neglected tropical diseases and taking human proteins as a reference point to the highest evolved organism in the evolutionary trait. Lower eukaryotes’ CRIB containing proteins fall into conventional effector molecules, PAKs (p21 activated kinase), Wiskoit-Aldrich Syndrome proteins family, and some have unique domain combinations unlike any known proteins. We also highlight the correlation between the effector protein isoforms and their selective specificity for Cdc42 or Rac proteins during evolution. Here, we report CRIB containing effector proteins; ten in Dictyostelium and Entamoeba, fourteen in Acanthamoeba, one in Trypanosoma and Giardia. CRIB containing effector proteins that have been studied so far in humans are potential candidates for drug targets in cancer, neurological disorders, and others. Conventional CRIB containing proteins from protozoan parasites remain largely elusive and our data provides their identification and classification for further in-depth functional validations. The tropical diseases caused by protozoan parasites lack combinatorial drug targets as effective paradigms. Targeting signaling mechanisms operative in these pathogens can provide greater molecules in combatting their infections.

Dihydrotanshinone I inhibits the growth of hepatoma cells by direct inhibition of Src

BACKGROUND

Liver cancer is one of the leading causes of cancer-related death worldwide. Dihydrotanshinone I (DHI) was shown to inhibit the growth of several types of cancer. However, research related to hepatoma treatment using DHI is limited.

PURPOSE

Here, we explored the inhibitory effect of DHI on the growth of hepatoma cells, and investigated the underlying molecular mechanisms.

METHODS

The proliferation of Hep3B, SMCC-7721 and SK-Hep1 hepatoma cells was evaluated using the MTS and Edu staining assay. Hepatoma cell death was analyzed with a LIVE/DEAD Cell Imaging Kit. The relative expression and phosphorylation of proto-oncogene tyrosine-protein kinase Src (Src) and signal transducer and activator of transcription-3 (STAT3) proteins in hepatoma cells, as well as the expression of other protein components, were measured by western blotting. The structural interaction of DHI with Src proteins was evaluated by molecular docking, molecular dynamics simulation, surface plasmon resonance imaging and Src kinase inhibition assay. Src overexpression was achieved by infection with an adenovirus vector encoding human Src. Subsequently, the effects of DHI on tumor growth inhibition were further validated using mouse xenograft models of hepatoma.

RESULTS

In vitro studies showed that treatment with DHI inhibited the proliferation and promoted cell death of Hep3B, SMCC-7721 and SK-Hep1 hepatoma cells. We further identified and verified Src as a direct target of DHI by using molecular stimulation, surface plasmon resonance image and Src kinase inhibition assay. Treatment with DHI reduced the in vitro phosphorylation levels of Src and STAT3, a transcription factor regulated by Src. In the xenograft mouse models, DHI dose-dependently suppressed tumor growth and Src and STAT3 phosphorylation. Moreover, Src overexpression partly abrogated the inhibitory effects of DHI on the proliferation and cell death in hepatoma cells.

CONCLUSION

Our results suggest that DHI inhibits the growth of hepatoma cells by direct inhibition of Src.

Novel Small Molecules Capable of Blocking mtRAS-Signaling Pathway

RAS mutants are involved in approximately 30% of all human cancers and have been regarded as undruggable targets owing to relatively smooth protein surface and obscure binding pockets. In our previous study, we have demonstrated that GNF-7, a multi-targeted kinase inhibitor, possesses potent anti-proliferative activity against Ba/F3 cells transformed with NRAS-G12D. Based on our further analysis using Ba/F3 cells transformed with mtRAS, we discovered a series of pyrimido[4,5-d]pyrimidin-2-one analogues as mtRAS-signaling pathway blockers. In addition, our efforts expanded the assessment to cancer cells with mtRAS, which revealed that these substances are also capable of strongly suppressing the proliferation of various cancer cells harboring KRAS-G12D (AsPC-1), KRAS-G12V (SW480, DU-145), KRAS-G12C (H358), KRAS-G13D (MDA-MB-231), KRAS-Q61L (HT-29), and NRAS-Q61L (OCI-AML3). We herein report novel and potent mtRAS-signaling pathway blockers, SIJ1795 and SIJ1772, possessing 2 to 10-fold increased anti-proliferative activities compared to those of GNF-7 on cancer cells harboring mtRAS as well as on Ba/F3 cells transformed with mtRAS. Both SIJ1795 and SIJ1772 attenuate phosphorylation of RAS downstream molecules (AKT and MEK) and induce apoptosis and G0/G1 cell cycle arrest on cancer cells with mtRAS. Moreover, both substances substantially suppress the migration, invasion, and colony formation of cancer cells harboring mtRAS. Taken together, this study led us to identification of SIJ1795 and SIJ1772 capable of strongly inhibiting mtRAS-signaling pathway on cancer cells harboring mtRAS.

Small Molecules Targeting Activated Cdc42-Associated Kinase 1 (ACK1/TNK2) for the Treatment of Cancers

Activated Cdc42-associated kinase 1 (ACK1/TNK2) is a nonreceptor tyrosine kinase with a unique structure. It not only can act as an activated transmembrane effector of receptor tyrosine kinases (RTKs) to transmit various RTK signals but also can play a corresponding role in epigenetic regulation. A number of studies have shown that ACK1 is a carcinogenic factor. Blockage of ACK1 has been proven to be able to inhibit cancer cell survival, proliferation, migration, and radiation resistance. Thus, ACK1 is a promising potential antitumor target. To date, despite many efforts to develop ACK1 inhibitors, no specific small molecule inhibitors have entered clinical trials. This Perspective provides an overview of the structural features, biological functions, and association with diseases of ACK1 and in vitro and in vivo activities, selectivity, and therapeutic potential of small molecule ACK1 inhibitors with different chemotypes.

Therapeutic Targeting of the Gas6/Axl Signaling Pathway in Cancer

Many signaling pathways are dysregulated in cancer cells and the host tumor microenvironment. Aberrant receptor tyrosine kinase (RTK) pathways promote cancer development, progression, and metastasis. Hence, numerous therapeutic interventions targeting RTKs have been actively pursued. Axl is an RTK that belongs to the Tyro3, Axl, MerTK (TAM) subfamily. Axl binds to a high affinity ligand growth arrest specific 6 (Gas6) that belongs to the vitamin K-dependent family of proteins. The Gas6/Axl signaling pathway has been implicated to promote progression, metastasis, immune evasion, and therapeutic resistance in many cancer types. Therapeutic agents targeting Gas6 and Axl have been developed, and promising results have been observed in both preclinical and clinical settings when such agents are used alone or in combination therapy. This review examines the current state of therapeutics targeting the Gas6/Axl pathway in cancer and discusses Gas6- and Axl-targeting agents that have been evaluated preclinically and clinically.

Significant Gene Biomarker Tyrosine Kinase Non-receptor 2 Mediated Cell Proliferation and Invasion in Colon Cancer

Objective: This study aimed to investigate the expression and biological functions of TNK2 and miR-125a-3p in colon cancer.

Materials and methods: The expression of TNK2 and miR-125a-3p in colon cancer tissues was analyzed using data deposited on public databases including UALCAN and ONCOMINE. We verified their expression in colon cancer cell lines by RT-qPCR and western blotting. By regulating the expression of TNK2 and miR-125a-3p in colon cancer cells, their functions and potential mechanisms were explored.

Results:TNK2 was overexpressed in colon cancer cell lines, and it was found to directly bind to miR-125a-3p, which was downregulated in these cell lines. Their expression affected the proliferation and invasion of colon cancer cells. Additionally, colon cancer patients with lower TNK2 expression had better prognoses than those with higher TNK2 expression.

Conclusion: Our results indicated that TNK2 and miR-125a-3p play critical roles in colon cancer, and could also serve as biomarkers for the diagnosis and prognosis of this malignant disease.

Role of the ABL tyrosine kinases in the epithelial-mesenchymal transition and the metastatic cascade

The ABL kinases, ABL1 and ABL2, promote tumor progression and metastasis in various solid tumors. Recent reports have shown that ABL kinases have increased expression and/or activity in solid tumors and that ABL inactivation impairs metastasis. The therapeutic effects of ABL inactivation are due in part to ABL-dependent regulation of diverse cellular processes related to the epithelial to mesenchymal transition and subsequent steps in the metastatic cascade. ABL kinases target multiple signaling pathways required for promoting one or more steps in the metastatic cascade. These findings highlight the potential utility of specific ABL kinase inhibitors as a novel treatment paradigm for patients with advanced metastatic disease. Video abstract.

Combined inhibition of ACK1 and AKT shows potential toward targeted therapy against KRAS-mutant non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) with Kirsten RAt Sarcoma 2 viral oncogene homolog (KRAS) mutation has become a clinical challenge in cancer treatment as KRAS-mutant tumors are often resistant to conventional anti-tumor therapies. Activated CDC42-associated kinase 1 (ACK1), an activator of protein kinase B (AKT), is a promising target for KRAS-mutant tumor therapy, but the downstream ACK1 signaling remains poorly understood. The aim of this study was to evaluate the effectiveness of combined ACK1/AKT inhibition on the proliferation, migration, invasion, and apoptosis of KRAS-mutant NSCLC cell lines (NCI-H23, NCI-H358, and A549). The cells were treated with an inhibitor of either ACK1 (dasatinib or sunitinib) or AKT (MK-2206 or GDC-0068), and the optimal concentrations of the two yielding synergistic tumor-killing effects were determined by applying the Chou-Talalay equation for drug combinations. We showed that combined administration of ACK1 and AKT inhibitors at the optimal concentrations effectively suppressed NSCLC cell viability and promoted apoptosis while inducing cell cycle arrest at the G2 phase. Moreover, NSCLC cell migration and invasion were inhibited by combined ACK1/AKT inhibition. These phenomena were associated with the reduced phosphorylation levels of ACK1 and AKT (at Ser473 and Thr308), as well as alterations in caspase-dependent apoptotic signaling. Collectively, our results demonstrate the promising therapeutic potential of combined ACK1/AKT inhibition as a strategy against KRAS-mutant NSCLC. Our findings provide the basis for the clinical translation of biological targeted drugs (ACK1 and AKT inhibitors) and their rational combination in cancer treatment.

LINCS gene expression signature analysis revealed bosutinib as a radiosensitizer of breast cancer cells by targeting eIF4G1

Radioresistance is the predominant cause for radiotherapy failure and disease progression, resulting in increased breast cancer‑associated mortality. Using gene expression signature analysis of the Library of Integrated Network‑Based Cellular Signatures (LINCS) and Gene Expression Omnibus (GEO), the aim of the present study was to systematically identify potential candidate radiosensitizers from known drugs. The similarity of integrated gene expression signatures between irradiated eukaryotic translation initiation factor 4 γ 1 (eIF4G1)‑silenced breast cancer cells and known drugs was measured using enrichment scores (ES). Drugs with positive ES were selected as potential radiosensitizers. The radiosensitizing effects of the candidate drugs were analyzed in breast cancer cell lines (MCF‑7, MX‑1 and MDA‑MB‑231) using CCK‑8 and colony formation assays following exposure to ionizing radiation. Cell apoptosis was measured using flow cytometry. The expression levels of eIF4G1 and DNA damage response (DDR) proteins were analyzed by western blotting. Bosutinib was identified as a promising radiosensitizer, as its administration markedly reduced the dosage required both for the drug and for ionizing radiation, which may be associated with fewer treatment‑associated adverse reactions. Moreover, combined treatment of ionizing radiation and bosutinib significantly increased cell killing in all three cell lines, compared with ionizing radiation or bosutinib alone. Among the three cell lines, MX‑1 cells were identified as the most sensitive to both ionizing radiation and bosutinib. Bosutinib markedly downregulated the expression of eIF4G1 in a dose‑dependent manner and also reduced the expression of DDR proteins (including ATM, XRCC4, ATRIP, and GADD45A). Moreover, eIF4G1 was identified as a key target of bosutinib that may regulate DNA damage induced by ionizing radiation. Thus, bosutinib may serve as a potential candidate radiosensitizer for breast cancer therapy.

Identification of downstream signaling cascades of ACK1 and prognostic classifiers in non-small cell lung cancer

Activated Cdc42-associated kinase 1 (ACK1) is an oncogene in multiple cancers, but the underlying mechanisms of its oncogenic role remain unclear in non-small cell lung cancer (NSCLC). Herein, we comprehensively investigated the ACK1-regulated cell processes and downstream signaling pathways, as well as its prognostic value in NSCLC. We found that ACK1 gene amplification was associated with mRNA levels in The Cancer Genome Atlas (TCGA) lung cancer cohort. The Oncomine databases showed significantly elevated ACK1 levels in lung cancer. In vitro, an ACK1 inhibitor (dasatinib) increased the sensitivity of NSCLC cell lines to AKT or MEK inhibitors. RNA-sequencing results demonstrated that an ACK1 deficiency in A549 cells affected the MAPK, PI3K/AKT, and Wnt pathways. These results were validated by gene set enrichment analysis (GSEA) of data from 188 lung cancer cell lines. Using Cytoscape, we dissected 14 critical ACK1-regulated genes. The signature with the 14 genes and ACK1 could significantly dichotomize the TCGA lung cohort regarding overall survival. The prognostic accuracy of this signature was confirmed in five independent lung cancer cohorts and was further validated by a prognostic nomogram. Our study unveiled several downstream signaling pathways for ACK1, and the proposed signature may be a promising prognostic predictor for NSCLC.

ZenoFishDb v1.1: A Database for Xenotransplantation Studies in Zebrafish

Rapidly accumulating literature has proven feasibility of the zebrafish xenograft models in cancer research. Nevertheless, online databases for searching the current zebrafish xenograft literature are in great demand. Herein, we have developed a manually curated database, called ZenoFishDb v1.1 (https://konulab.shinyapps.io/zenofishdb), based on R Shiny platform aiming to provide searchable information on ever increasing collection of zebrafish studies for cancer cell line transplantation and patient-derived xenografts (PDXs). ZenoFishDb v1.1 user interface contains four modules: DataTable, Visualization, PDX Details, and PDX Charts. The DataTable and Visualization pages represent xenograft study details, including injected cell lines, PDX injections, molecular modifications of cell lines, zebrafish strains, as well as technical aspects of the xenotransplantation procedures in table, bar, and/or pie chart formats. The PDX Details module provides comprehensive information on the patient details in table format and can be searched and visualized. Overall, ZenoFishDb v1.1 enables researchers to effectively search, list, and visualize different technical and biological attributes of zebrafish xenotransplantation studies particularly focusing on the new trends that make use of reporters, RNA interference, overexpression, or mutant gene constructs of transplanted cancer cells, stem cells, and PDXs, as well as distinguished host modifications.

Comprehensive Analysis of the Immune Implication of ACK1 Gene in Non-small Cell Lung Cancer

Activated Cdc42-associated kinase1 (ACK1), a non-receptor tyrosine kinase, has been considered as an oncogene and therapeutic target in various cancers. However, its contribution to cancer immunity remains uncertain. Here we first compared the profiles of immune cells in cancerous and normal tissues in The Cancer Genome Atlas (TCGA) lung cancer cohorts. Next, we found that the immune cell infiltration levels were associated with the ACK1 gene copy numbers in lung cancer. Consistently, our RNA-seq data unveiled that the silencing of ACK1 upregulated several immune pathways in lung cancer cells, including the T cell receptor signaling pathway. The impacts of ACK1 on immune activity were validated by Gene Set Enrichment Analysis of RNA-seq data of 188 lung cancer cell lines from the public database. A pathway enrichment analysis of 35 ACK1-associated immunomodulators and 50 tightly correlated genes indicated the involvement of the PI3K-Akt and Ras signaling pathways. Based on ACK1-associated immunomodulators, we established multiple-gene risk prediction signatures using the Cox regression model. The resulting risk scores were an independent prognosis predictor in the TCGA lung cohorts. We also accessed the prognostic accuracy of the risk scores with a receiver operating characteristic methodology. Finally, a prognostic nomogram, accompanied by a calibration curve, was constructed to predict individuals' 3- and 5-year survival probabilities. Our findings provided evidence of ACK1's implication in tumor immunity, suggesting that ACK1 may be a potential immunotherapeutic target for non-small cell lung cancer (NSCLC). The nominated immune signature is a promising prognostic biomarker in NSCLC.

Discovery of a novel third-generation EGFR inhibitor and identification of a potential combination strategy to overcome resistance

BACKGROUND

Non-small cell lung cancer (NSCLC) patients with activating EGFR mutations initially respond to first-generation EGFR inhibitors; however, the efficacy of these drugs is limited by acquired resistance driven by the EGFR T790M mutation. The discovery of third-generation EGFR inhibitors overcoming EGFR T790M and their new resistance mechanisms have attracted much attention.

METHODS

We examined the antitumor activities and potential resistance mechanism of a novel EGFR third-generation inhibitor in vitro and in vivo using ELISA, SRB assay, immunoblotting, flow cytometric analysis, kinase array, qRT-PCR and tumor xenograft models. The clinical effect on a patient was evaluated by computed tomography scan.

RESULTS

We identified compound ASK120067 as a novel inhibitor of EGFR T790M, with selectivity over EGFR WT. ASK120067 exhibited potent anti-proliferation activity in tumor cells harboring EGFR T790M (NCI-H1975) and sensitizing mutations (PC-9 and HCC827) while showed moderate or weak inhibition in cells expressing EGFR WT. Oral administration of ASK120067 induced tumor regression in NSCLC xenograft models and in a PDX model harboring EGFR T790M. The treatment of one patient with advanced EGFR T790M-positive NSCLC was described as proof of principle. Moreover, we found that hyperphosphorylation of Ack1 and the subsequent activation of antiapoptotic signaling via the AKT pathway contributed to ASK120067 resistance. Concomitant targeting of EGFR and Ack1 effectively overrode the acquired resistance of ASK120067 both in vitro and in vivo.

CONCLUSIONS

Our results idenfity ASK120067 as a promising third-generation EGFR inhibitor and reveal for the first time that Ack1 activation as a novel resistance mechanism to EGFR inhibitors that guide to potential combination strategy.

Zebrafish patient avatars in cancer biology and precision cancer therapy

In precision oncology, two major strategies are being pursued for predicting clinically relevant tumour behaviours, such as treatment response and emergence of drug resistance: inference based on genomic, transcriptomic, epigenomic and/or proteomic analysis of patient samples, and phenotypic assays in personalized cancer avatars. The latter approach has historically relied on in vivo mouse xenografts and in vitro organoids or 2D cell cultures. Recent progress in rapid combinatorial genetic modelling, the development of a genetically immunocompromised strain for xenotransplantation of human patient samples in adult zebrafish and the first clinical trial using xenotransplantation in zebrafish larvae for phenotypic testing of drug response bring this tiny vertebrate to the forefront of the precision medicine arena. In this Review, we discuss advances in transgenic and transplantation-based zebrafish cancer avatars, and how these models compare with and complement mouse xenografts and human organoids. We also outline the unique opportunities that these different models present for prediction studies and current challenges they face for future clinical deployment.

Zebrafish Xenografts for Drug Discovery and Personalized Medicine

Cancer is the second leading cause of death in the world. Given that cancer is a highly individualized disease, predicting the best chemotherapeutic treatment for individual patients can be difficult. Ex vivo models such as mouse patient-derived xenografts (PDX) and organoids are being developed to predict patient-specific chemosensitivity profiles before treatment in the clinic. Although promising, these models have significant disadvantages including long growth times that introduce genetic and epigenetic changes to the tumor. The zebrafish xenograft assay is ideal for personalized medicine. Imaging of the small, transparent fry is unparalleled among vertebrate organisms. In addition, the speed (5-7 days) and small patient tissue requirements (100-200 cells per animal) are unique features of the zebrafish xenograft model that enable patient-specific chemosensitivity analyses.

Modeling of Solid-Tumor Microenvironment in Zebrafish (Danio Rerio) Larvae

The zebrafish larvae have emerged as a powerful model for studying tumorigenesis in vivo, with remarkable conservation with mammals in genetics, molecular and cell biology. Zebrafish tumor models bear the significant advantages of optical clarity in comparison to that in the mammalian models, allowing noninvasive investigation of the tumor cell and its microenvironment at single-cell resolution. Here we review recent progressions in the field of zebrafish models of solid tumor diseases in two main categories: the genetically engineered tumor models in which all cells in the tumor microenvironment are zebrafish cells, and xenograft tumor models in which the tumor microenvironment is composed of zebrafish cells and cells from other species. Notably, the zebrafish patient-derived xenograft (zPDX) models can be used for personalized drug assessment on primary tumor biopsies, including the pancreatic cancer. For the future studies, a series of high throughput drug screenings on the library of transgenic zebrafish models of solid tumor are expected to provide systematic database of oncogenic mutation, cell-of-origin, and leading compounds; and the humanization of zebrafish in genetics and cellular composition will make it more practical hosts for zPDX modeling. Together, zebrafish tumor model systems are unique and convenient in vivo platforms, with great potential to serve as valuable tools for cancer researches.

Research Progress of the Functional Role of ACK1 in Breast Cancer

ACK1 is a nonreceptor tyrosine kinase with a unique structure, which is tightly related to the biological behavior of tumors. Previous studies have demonstrated that ACK1 was involved with multiple signaling pathways of tumor progression. Its crucial role in tumor cell proliferation, apoptosis, invasion, and metastasis was tightly related to the prognosis and clinicopathology of cancer. ACK1 has a unique way of regulating cellular pathways, different from other nonreceptor tyrosine kinases. As an oncogenic kinase, recent studies have shown that ACK1 plays a critical regulatory role in the initiation and progression of tumors. In this review, we will be summarizing the structural characteristics, activation, and regulation of ACK1 in breast cancer, aiming to deeply understand the functional and mechanistic role of ACK1 and provide novel therapeutic strategies for breast cancer treatment.

Expression of Jagged1/Notch3 Signaling Pathway and their Relationship with the Tumor Angiogenesis in TNBC

BACKGROUND AND AIMS

Jagged1/Notch3 signaling pathway plays a key role in angiogenesis of breast cancer, but little is known in TNBC. This study was designed to investigate the expression of Jagged1/Notch3 mRNA and protein in TNBC, analyze their correlations with clinicopathological characteristics and prognosis. Moreover, the interrelationship among Jagged1/Notch3 and VEGF was initially evaluated.

METHODS

Jagged1/Notch3 mRNA and protein expression levels were determined by Q-RT-PCR and Western blotting. Additionally, Immunohistochemistry for Jagged1/Notch3 was detected by Ventana platform, VEGF and CD34 was performed using the EnVision/HRP technique.

RESULTS

mRNA transcriptionof Jagged1/Notch3 was in accord with protein expression. TNBC patients with positive Jagged1 expression had poorer DFS (p = 0.008) and OS (p = 0.004). Jagged1 expression was independent predictors of OS (p = 0.038). The expression of VEGF was positively correlative to MVD (p = 0.018), MVD was significantly associated with Jagged1 (p <0.0001) and Notch3 (p <0.0001). The expression of Jagged1/Notch3 has no correlation with VEGF, only in positive VEGF expression of TNBC patients Jagged1/Notch3 had influence on DFS and OS (p <0.05).

CONCLUSION

Jagged1/Notch3 was -expressed at both the mRNA and protein levels, Jagged1 served as an independent predictor of poor prognosis. We speculate that there is a cross-talk between Jagged1/Notch3 and VEGF in TNBC angiogenesis. Jagged1/Notch3 is expected to be an important signaling pathway for TNBC progression and a potential target for TNBC neovascularization therapy.

Involvement of Activated Cdc42 Kinase1 in Colitis and Colorectal Neoplasms

BACKGROUND Activated Cdc42 kinase1 (ACK1) is a non-receptor tyrosine kinase which is critical for cell survival, proliferation, and migration. Genomic amplification of ACK1 has been reported in multiple human cancers. We aimed to investigate ACK1 protein expression in colorectal mucosa with inflammation and neoplasm, and to evaluate its correlation with disease activity and severity. MATERIAL AND METHODS A total of 250 individuals who underwent total colonoscopy were collected randomly from January 2007 to May 2013 in Nanfang Hospital, Guangzhou, China. Colorectal mucosal biopsy specimens were obtained by endoscopy from 78 patients with ulcerative colitis (UC), 22 with Crohn's disease (CD), 20 with infectious colitis, 26 with non-IBD and noninfectious colitis, 16 with sporadic adenomas, 4 with dysplasia-associated lesions or masses, 10 with sporadic colorectal cancer (CRC), 4 with UC-related CRC, 10 with hyperplastic polyps, and 60 without colonic abnormalities. ACK1 protein levels were determined immunohistochemically. The correlations of ACK1 expression with disease activity and severity were also evaluated. RESULTS Significantly increased ACK1 expression was observed in epithelial cells of colorectal mucosa with inflammation and dysplasia compared to controls (P<0.05). ACK1 expression correlated with clinical activity in IBD (χ²=4.57, P=0.033 for UC; χ²=5.68, P=0.017 for CD), as well as grade of dysplasia in preneoplastic lesions (P<0.05). No significant differences in ACK1 expression were found between UC and CD, or between IBD and non-IBD conditions (P>0.05). CONCLUSIONS ACK1 protein is increased extensively in colitis and colorectal dysplasia. ACK1 overexpression may play a role in colorectal inflammation and neoplasms.

Activated Cdc42 kinase 1 and hepatocellular carcinoma

Primary liver cancer includes hepatocellular carcinoma (HCC) and cholangiocellular carcinoma. The incidence of HCC is different between countries and regions. As one of the common malignant tumors in China, HCC has high mortality and is the second most common cause of cancer-related death. Elucidating the molecular mechanism of HCC pathogenesis is important for the diagnosis and treatment of liver cancer in China. The expression of activated Cdc42 kinase 1 (ACK1) has been found in a variety of cancers, and ACK1 participates in the occurrence and development of cancers. However, there are currently few studies about the relationship between ACK1 protein and HCC. This paper reviews the structure characteristics and biological function of ACK1 as well as its relationship with invasion and metastasis of HCC.

Hypoxic regulation of the noncoding genome and NEAT1

Activation of hypoxia pathways is both associated with and contributes to an aggressive phenotype across multiple types of solid cancers. The regulation of gene transcription by hypoxia-inducible factor (HIF) is a key element in this response. HIF directly upregulates the expression of many hundreds of protein-coding genes, which act to both improve oxygen delivery and to reduce oxygen demand. However, it is now becoming apparent that many classes of noncoding RNAs are also regulated by hypoxia, with several (e.g. micro RNAs, long noncoding RNAs and antisense RNAs) under direct transcriptional regulation by HIF. These hypoxia-regulated, noncoding RNAs may act as effectors of the indirect response to HIF by acting on specific coding transcripts or by affecting generic RNA-processing pathways. In addition, noncoding RNAs may also act as modulators of the HIF pathway, either by integrating other physiological responses or, in the case of HIF-regulated, noncoding RNAs, by providing negative or positive feedback and feedforward loops that affect upstream or downstream components of the HIF cascade. These hypoxia-regulated, noncoding transcripts play important roles in the aggressive hypoxic phenotype observed in cancer.

The novel protective role of P27 in MLN4924-treated gastric cancer cells

The tumor-suppressor gene cyclin-dependent kinase inhibitor 1B (P27) is downregulated in gastric cancer cells mainly through proteolytic degradation mediated by the SKP-Cullin1-F-Box (SCF) complex. But the correlation between its downregulation and gastric cancer prognosis still remains indefinite. MLN4924, an anti-tumor agent, which suppresses the SCF complex by inhibiting Cullin1 neddylation, emerges as a promising tool to elucidate its functions in gastric cancer cells. In this study, MLN4924 induced significant growth inhibition of gastric cancer cells in a dose-dependent manner, along with the simultaneous accumulation of P27 and cell cycle abnormalities such as G2/M arrest. Importantly, we found that P27 silencing in MLN4924-treated cells resulted in an enhancement of growth inhibition both in vitro and in vivo. Mechanism analysis revealed the antagonism effects of antioxidants to this excess apoptosis, suggesting reactive oxygen species (ROS) overproduction especially in the mitochondria was the principal cause of the augmentation. Moreover, the robust ROS attacked the mitochondria to initiate collapse of the mitochondrial membrane permeability and the exportation of apoptosis-inducing factor (AIF), IAP-binding mitochondrial protein (SMAC/DIABLO) and cytochrome c. Finally, we also found that P27 knockdown affected the expression profile of several critical BH3 family members to amplify the mitochondrial dysfunction and apoptosis. In summary, our findings unveiled a protective role of P27 by maintaining mitochondrial membrane permeability in MLN4924-treated gastric cancer cells, and therefore highlighted the potential combination of MLN4924 with P27 inhibition to improve its therapeutic efficacy.

Activated cdc42-associated kinase is up-regulated in non-small-cell lung cancer and necessary for FGFR-mediated AKT activation

Activated cdc42-associated tyrosine kinase 1 (ACK1) has been reported to be implicated in non-small-cell lung cancer (NSCLC). However, the expression pattern and biological functions of ACK1 in the progression of NSCLC are not fully understood. In this study, it was found that the expression of ACK1 was significantly up-regulated in NSCLC samples compared to their adjacent normal tissues. Meanwhile, the expression of ACK1 was inversely correlated with the survival of NSCLC patients. Moreover, in the biological function studies, ACK1 was further validated to promote the growth, migration, and metastasis of NSCLC cells in vitro and in vivo. Mechanistically, ACK1 bind with FGFR1 and was essential for the phosphorylation of AKT induced by FGF. Our study demonstrated that ACK1 played an oncogenic role in the progression of NSCLC and ACK1 might be a promising target for the treatment of NSCLC.

Development of novel ACK1/TNK2 inhibitors using a fragment-based approach

The tyrosine kinase ACK1, a critical signal transducer regulating survival of hormone-refractory cancers, is an important therapeutic target, for which there are no selective inhibitors in clinical trials to date. This work reports the discovery of novel and potent inhibitors for ACK1 tyrosine kinase (also known as TNK2) using an innovative fragment-based approach. Focused libraries were designed and synthesized by selecting fragments from reported ACK inhibitors to create hybrid structures in a mix and match process. The hybrid library was screened by enzyme-linked immunosorbent assay-based kinase inhibition and (33)P HotSpot assays. Systematic structure-activity relationship studies led to the identification of compound (R)-9b, which shows potent in vitro (IC50 = 56 nM, n = 3, (33)P HotSpot assay) and in vivo (IC50 < 2 μM, human cancer cell lines) ACK1 inhibition. Both (R)-9b and (S)-9b were stable in human plasma and displayed a long half-life (t(1/2) > 6 h).

ACK1 promotes hepatocellular carcinoma progression via downregulating WWOX and activating AKT signaling

Several studies have revealed that ACK1 is upregulated in various cancers and promotes tumor progression. However, the role and mechanism of ACK1 in hepatocellular carcinoma (HCC) remains unknown. In this study, the expression of ACK1 was assessed in several cell lines and 150 pairs of HCC and adjacent noncancerous liver tissues. The protein expression of p-ACK1 and WWOX were detected by immunohistochemistry to evaluate their correlation with ACK1. Flow cytometry, caspase 3/7 activity assay, BrdU cell proliferation assay, MTT assay and Transwell assay were used to detect apoptosis, proliferation, invasion and migration of HCC cells. The regulatory effect of ACK1 on WWOX, AKT, p-AKT, MMP2 and MMP9 in HCC cells was confirmed by immuno-blotting. We found that ACK1 was more highly expressed in HCC tissues than in non-HCC tissues, and over-expression of ACK1 was correlated with clinicopathological features of poor prognosis. Clinical analysis demonstrated that ACK1 is an independent prognostic marker for predicting overall survival and disease-free survival of HCC patients. Pearson's correlation coefficient analysis indicated that ACK1 was positively associated with p-ACK1 and was negatively associated with WWOX expression. In vitro studies showed that knockdown of ACK1 promoted HCC cell apoptosis and repressed HCC cells invasion, migration and proliferation. Furthermore, knockdown of ACK1 resulted in upregulation of WWOX and inactivation of AKT signaling. In this study, we also found that knockdown of ACK1 resulted in the downregulation of MMP2 and MMP9 in HCC. Our results indicate that ACK1 is an independent prognostic marker and promotes HCC progression via downregulating WWOX and activating AKT signaling.

Combined inhibition of AXL, Lyn and p130Cas kinases block migration of triple negative breast cancer cells

Blocking the migration of metastatic cancer cells is a major goal in the therapy of cancer. The receptor tyrosine kinase AXL is one of the main triggers for cancer cell migration in neoplasia of breast, colon, skin, thyroid and prostate. In our study we analyzed the effect of AXL inhibition on cell motility and viability in triple negative breast cancer cell lines overexpressing AXL. Thereby we reveal that the compound BMS777607, exhibiting the lowest IC50 values for inhibition of AXL kinase activity in the studied cell lines, attenuates cell motility to a lower extent than the kinase inhibitors MPCD84111 and SKI606. By analyzing the target kinases of MPCD84111 and SKI606 with kinase profiling assays we identified Lyn, a Src family kinase, as a target of both compounds. Knockdown of Lyn and the migration-related CRK-associated substrate (p130Cas), had a significant inhibitory effect on cell migration. Taken together, our findings highlight the importance of combinatorial or multikinase inhibition of non-receptor tyrosine kinases and AXL receptor tyrosine kinase in the therapy of triple negative breast cancer.

ACK1/TNK2 tyrosine kinase: molecular signaling and evolving role in cancers

Deregulated tyrosine kinase signaling alters cellular homeostasis to drive cancer progression. The emergence of a non-receptor tyrosine kinase, ACK1 as an oncogenic kinase, has uncovered novel mechanisms by which tyrosine kinase signaling promotes cancer progression. While early studies focused on ACK1 (also known as activated Cdc42-associated kinase 1 or TNK2) as a cytosolic effecter of activated transmembrane receptor tyrosine kinases (RTKs), wherein it shuttles between the cytosol and the nucleus to rapidly transduce extracellular signals from the RTKs to the intracellular effectors, recent data unfold a new aspect of its functionality as an epigenetic regulator. ACK1 interacts with the Estrogen Receptor (ER)/histone demethylase KDM3A (JHDM2a) complex, modifies KDM3A by tyrosine phosphorylation to regulate transcriptional outcome at HOXA1 locus to promote the growth of tamoxifen-resistant breast cancer. It is also well established that ACK1 regulates the activity of Androgen Receptor (AR) by tyrosine phosphorylation to fuel the growth of hormone-refractory prostate cancers. Further, recent explosion in genomic sequencing has revealed recurrent ACK1 gene amplification and somatic mutations in a variety of human malignancies, providing a molecular basis for its role in neoplastic transformation. In this review, we will discuss the various facets of ACK1 signaling, including its newly uncovered epigenetic regulator function, which enables cells to bypass the blockade to major survival pathways to promote resistance to standard cancer treatments. Not surprisingly, cancer cells appear to acquire an `addiction’ to ACK1 mediated survival, particularly under stress conditions, such as growth factor deprivation or genotoxic insults or hormone deprivation. With the accelerated development of potent and selective ACK1 inhibitors, targeted treatment for cancers harboring aberrant ACK1 activity may soon become a clinical reality.