Src as a potential therapeutic target in non-small-cell lung cancer

Drivergene.net: A Cytoscape app for the identification of driver nodes of large-scale complex networks and case studies in discovery of drug target genes

There are no tools to identify driver nodes of large-scale networks in approach of competition-based controllability. This study proposed a novel method for this computation of large-scale networks. It implemented the method in a new Cytoscape plug-in app called Drivergene.net. Experiments of the software on large-scale biomolecular networks have shown outstanding speed and computing power. Interestingly, 86.67% of the top 10 driver nodes found on these networks are anticancer drug target genes that reside mostly at the innermost K-cores of the networks. Finally, compared method with those of five other researchers and confirmed that the proposed method outperforms the other methods on identification of anticancer drug target genes. Taken together, Drivergene.net is a reliable tool that efficiently detects not only drug target genes from biomolecular networks but also driver nodes of large-scale complex networks. Drivergene.net with a user manual and example datasets are available https://github.com/tinhpd/Drivergene.git.

Multiomics analysis identifies oxidative phosphorylation as a cancer vulnerability arising from myristoylation inhibition

BACKGROUND

In humans, two ubiquitously expressed N-myristoyltransferases, NMT1 and NMT2, catalyze myristate transfer to proteins to facilitate membrane targeting and signaling. We investigated the expression of NMTs in numerous cancers and found that NMT2 levels are dysregulated by epigenetic suppression, particularly so in hematologic malignancies. This suggests that pharmacological inhibition of the remaining NMT1 could allow for the selective killing of these cells, sparing normal cells with both NMTs.

METHODS AND RESULTS

Transcriptomic analysis of 1200 NMT inhibitor (NMTI)-treated cancer cell lines revealed that NMTI sensitivity relates not only to NMT2 loss or NMT1 dependency, but also correlates with a myristoylation inhibition sensitivity signature comprising 54 genes (MISS-54) enriched in hematologic cancers as well as testis, brain, lung, ovary, and colon cancers. Because non-myristoylated proteins are degraded by a glycine-specific N-degron, differential proteomics revealed the major impact of abrogating NMT1 genetically using CRISPR/Cas9 in cancer cells was surprisingly to reduce mitochondrial respiratory complex I proteins rather than cell signaling proteins, some of which were also reduced, albeit to a lesser extent. Cancer cell treatments with the first-in-class NMTI PCLX-001 (zelenirstat), which is undergoing human phase 1/2a trials in advanced lymphoma and solid tumors, recapitulated these effects. The most downregulated myristoylated mitochondrial protein was NDUFAF4, a complex I assembly factor. Knockout of NDUFAF4 or in vitro cell treatment with zelenirstat resulted in loss of complex I, oxidative phosphorylation and respiration, which impacted metabolomes.

CONCLUSIONS

Targeting of both, oxidative phosphorylation and cell signaling partly explains the lethal effects of zelenirstat in select cancer types. While the prognostic value of the sensitivity score MISS-54 remains to be validated in patients, our findings continue to warrant the clinical development of zelenirstat as cancer treatment.

Discovery of a Covalent Inhibitor Selectively Targeting the Autophosphorylation Site of c-Src Kinase

Nonreceptor tyrosine kinase c-Src plays a crucial role in cell signaling and contributes to tumor progression. However, the development of selective c-Src inhibitors turns out to be challenging. In our previous study, we performed posttranslational modification-inspired drug design (PTMI-DD) to provide a plausible way for designing selective kinase inhibitors. In this study, after identifying a unique pocket comprising a less conserved cysteine and an autophosphorylation site in c-Src as well as a promiscuous covalent inhibitor, chemical optimization was performed to obtain (R)-LW-Srci-8 with nearly 75-fold improved potency (IC50 = 35.83 ± 7.21 nM). Crystallographic studies revealed the critical C-F···C═O interactions that may contribute to tight binding. The kinact and Ki values validated the improved binding affinity and decreased warhead reactivity of (R)-LW-Srci-8 for c-Src. Notably, in vitro tyrosine kinase profiling and cellular activity-based protein profiling (ABPP) cooperatively indicated a specific inhibition of c-Src by (R)-LW-Srci-8. Intriguingly, (R)-LW-Srci-8 preferentially binds to inactive c-Src with unphosphorylated Y419 both in vitro and in cells, subsequently disrupting the autophosphorylation. Collectively, our study demonstrated the feasibility of developing selective kinase inhibitors by cotargeting a nucleophilic residue and a posttranslational modification site and providing a chemical probe for c-Src functional studies.

Clinical efficacy and potential mechanism of ginseng polysaccharides in the treatment of non-small cell lung cancer based on meta-analysis associated with network pharmacology

Background

The ginseng polysaccharide injection is a well-known traditional Chinese medicine often employed as a supplementary treatment for cancer. This treatment can not only alleviate the adverse effects caused by tumor radiotherapy and chemotherapy but also enhance the immune system of individuals diagnosed with lung cancer. It is important to acknowledge the efficacy of ginseng polysaccharide injection in the treatment of non-small cell lung cancer (NSCLC). However, these small-sample studies may have certain biases, and the underlying mechanisms of ginseng polysaccharides therapy for NSCLC are still unclear.

Methods

The present study involved a systematic review of the literature on randomized controlled trials (RCTs) focusing on using ginseng polysaccharide injection as a therapeutic approach for NSCLC. Seven databases were searched for eligible studies published before April 2023. Two researchers independently managed data extraction, risk of bias assessment, and data analyses using RevMan 5.3 software. In network pharmacology, we thoroughly searched the relevant literature on ginseng polysaccharides (GPs) and the PubChem database. This search aimed to identify the main active ingredients and targets associated with ginseng polysaccharides. Subsequently, we compared these targets with those of NSCLC and utilized bioinformatics techniques to analyze and explore their potential interactions.

Results

A total of 11 RCTs involving 845 patients with NSCLC were included in the meta-analysis. The meta-analysis revealed that ginseng polysaccharide injection combined significantly improved the objective response rate [RR = 1.45, 95% CI (1.26, 1.67), P < 0.00001]. Furthermore, it was observed that ginseng polysaccharide injection increased the serum levels of CD4+ T-lymphocytes (CD4+ T) [MD = 8.98, 95% CI (5.18, 12.78), P < 0.00001], and decreased the serum levels of CD8+ T-lymphocytes (CD8+ T) [MD = -2.68, 95% CI (-4.66, -0.70), P = 0.008]. Through network pharmacology analysis, a total of 211 target genes of GPs and 81 common targets were identified. GAPDH, EGFR, VEGFA, JUN, SRC, CASP3, STAT3, CCND1, HSP90AA1, and MMP9 were identified as the core target proteins. Additionally, KEGG enrichment analysis revealed 122 relevant signaling pathways, including Pathways in cancer, PD-L1 expression and PD-1 checkpoint pathway in cancer, and Proteoglycans in cancer.

Conclusion

Ginseng polysaccharide injection can improve the ORR of patients with NSCLC, increase the serum levels of CD4+ T, and decrease the serum levels of CD8+ T. The potential mechanism may be associated with the PD-1/PD-L1 signaling pathway.

A versatile engineered extracellular vesicle platform simultaneously targeting and eliminating senescent stromal cells and tumor cells to promote tumor regression

Chemotherapy is an important therapeutic approach for malignant tumors for it triggers apoptosis of cancer cells. However, chemotherapy also induces senescence of stromal cells in the tumor microenvironment to promote tumor progression. Strategies aimed at killing tumor cells while simultaneously eliminating senescent stromal cells represent an effective approach to cancer treatment. Here, we developed an engineered Src-siRNA delivery system based on small extracellular vesicles (sEVs) to simultaneously eliminate senescent stromal cells and tumor cells for cancer therapy. The DSPE-PEG-modified urokinase plasminogen activator (uPA) peptide was anchored to the membranes of induced mesenchymal stem cell-derived sEVs (uPA-sEVs), and Src siRNA was loaded into the uPA-sEVs by electroporation (uPA-sEVs-siSrc). The engineered uPA-sEVs-siSrc retained the basic sEVs properties and protected against siSrc degradation. uPA peptide modification enhanced the sEVs with the ability to simultaneously target doxorubicin-induced senescent stromal cells and tumor cells. Src silencing by uPA-sEVs-siSrc induced apoptosis of both senescent stromal cells and tumor cells. The uPA-sEVs-siSrc displayed preferential tumor accumulation and effectively inhibited tumor growth in a tumor xenograft model. Furthermore, uPA-sEVs-siSrc in combination with doxorubicin significantly reduced the senescence burden and enhanced the therapeutic efficacy of chemotherapy. Taken together, uPA-sEVs-siSrc may serve as a promising therapy to kill two birds with one stone, not only killing tumor cells to achieve remarkable antitumor effect, but also eliminating senescent cells to enhance the efficacy of chemotherapeutic agent in tumor regression.

Comprehensive analysis of mitophagy-related genes in NSCLC diagnosis and immune scenery: based on bulk and single-cell RNA sequencing data

Lung cancer is the main cause of cancer-related deaths, and non-small cell lung cancer (NSCLC) is the most common type. Understanding the potential mechanisms, prognosis, and treatment aspects of NSCLC is essential. This study systematically analyzed the correlation between mitophagy and NSCLC. Six mitophagy-related feature genes (SRC, UBB, PINK1, FUNDC1, MAP1LC3B, and CSNK2A1) were selected through machine learning and used to construct a diagnostic model for NSCLC. These feature genes are closely associated with the occurrence and development of NSCLC. Additionally, NSCLC was divided into two subtypes using unsupervised consensus clustering, and their differences in clinical characteristics, immune infiltration, and immunotherapy were systematically analyzed. Furthermore, the interaction between mitophagy-related genes (MRGs) and immune cells was analyzed using single-cell sequencing data. The findings of this study will contribute to the development of potential diagnostic biomarkers for NSCLC and the advancement of personalized treatment strategies.

The activated CD36-Src axis promotes lung adenocarcinoma cell proliferation and actin remodeling-involved metastasis in high-fat environment

Obesity/overweight and lipid metabolism disorders have become increased risk factors for lung cancer. Fatty acid translocase CD36 promotes cellular uptake of fatty acids. Whether and how CD36 facilitates lung adenocarcinoma (LUAD) growth in high-fat environment is unknown. Here, we demonstrated that palmitic acid (PA) or high-fat diet (HFD) promoted LUAD cell proliferation and metastasis in a CD36-dependent manner. Mechanistically, CD36 translocated from cytoplasm to cell membrane and interacted with Src kinase upon PA stimulation in human LUAD cells. Akt and ERK, downstream of Src, were then activated to mediate LUAD cell proliferation and metastasis. Furthermore, PA treatment promoted CD36 sarcolemmal translocation, where it activated Rac1 and upregulated MMP-9 through Src-Akt/ERK pathway, resulting in redistribution of cortactin, N-WASP and Arp2/3, and finally led to occurrence of finger-like protrusions of actin on cell surface to enhance cell metastasis. Compared with normal-chew diet (NCD) mice, the HFD group exhibited higher level of blood free fatty acid (FFA) and cholesterol (TC), developed larger xenograft LUAD tumors and enhanced tumor cell metastatic potential, which were accompanied by obvious sarcolemmal actin remodeling and were blocked by simultaneous CD36 knockdown in LUAD cells. Consistently, xenografted and tail vein-injected scramble-RNA-A549 cells but not CD36-shRNA-A549 in HFD mice formed metastatic LUAD tumors on the lung. CD36 inhibitor SSO significantly inhibited LUAD cell metastasis to the lung. Collectively, CD36 initiates Src signaling to promote LUAD cell proliferation and actin remodeling-involved metastasis under high-fat environment. Our study provides the new insights that CD36 is a valid target for LUAD therapy.

Targeting CD36 determines nicotine derivative NNK-induced lung adenocarcinoma carcinogenesis

Smoking carcinogen nicotine-derived nitrosamine ketone (NNK) is the most potent contributor to lung adenocarcinoma (LUAD) development, but the mechanism has not been fully elucidated. Here, we reported that fatty acid translocase CD36 was significantly overexpressed in both human LUAD tissues and NNK-induced A/J mice LUAD tumors. The overexpressed CD36 was positively correlated with Src kinase activation, smoking status, metastasis, and worse overall survival of patients with smoking history. Upon NNK binding with α7 nicotinic acetylcholine receptor (α7nAChR), sarcolemmal CD36 was increased and it interacted with surface α7nAChR and cytosol Src simultaneously, which in turn activated Src and downstream pro-carcinogenic kinase ERK1/2 and Akt, and finally caused LUAD cells to form subcutaneous and pulmonary metastatic tumors. This process could be blocked by CD36 knockdown and CD36 irreversible inhibitor SSO. Furthermore, the effect of NNK was inhibited obviously in CD36-/- A/J mice. Thus, targeting CD36 may provide a breakthrough therapy of LUAD.

Determining the mechanism of action of the Qishan formula against lung adenocarcinoma by integration of network pharmacology, molecular docking, and proteomics

BACKGROUND

Lung adenocarcinoma (LUAD) is the main pathological type of lung cancer. Qishan formula (QSF) is reportedly efficacious against LUAD. However, its mechanisms of action currently remain elusive. Therefore, network pharmacology, molecular docking techniques and proteomics were used to verify the potential pharmacological effects of QSF in the treatment of LUAD.

METHODS

The active ingredients and potential targets of QSF were obtained from the TCMSP, chemical source network and construct a drug-component-target networks using Cytoscape v3.7.2. Data for disease targets were obtained from 5 databases: TCGA, OMIM, DrugBank, DisGeNET, and GeneCards. Drug disease cross targets were used to construct protein-protein interaction networks for selecting the core targets using the STRING database and enrichment pathway networks using the DAVID database. Finally, TMT quantitative proteomics was used to identify the possible core targets and action pathways. Molecular docking to verify the affinity between components and targets.

RESULTS

Network pharmacology identified core components of QSF against LUAD included baicalein, methylophiopogonone B, quercetin, kaempferol, isorhamnetin, and luteolin, which can act on 10 key targets (SRC, TP53, PIK3R1, MAPK3, STAT3, MAKP1, HSP90AA1, PIK3CA, HRAS, and AKT1). QSF might play a therapeutic role in LUAD by regulating biological processes such as signal transduction, protein phosphorylation, cell proliferation, and apoptosis, as well as the PI3K/AKT, MAPK, FoxO, and other signaling pathways. Proteomics identified 207 differentially expressed proteins, and by integrating with network pharmacology and molecular docking results we found that 6 core components of QSF may target TP53 against LUAD through the PI3K/AKT signaling pathway.

CONCLUSION

QSF is a multitarget recipe potentially exerting pleiotropic effects in LUAD.

The Biology and Therapeutic Potential of the Src-YAP Axis in Non-Small Cell Lung Cancer (NSCLC)

Non-small cell lung cancer (NSCLC) is the most common lung cancer type which accounts for the majority (~85%) of all lung cancer cases [...].

A Phase I Study of the Non-Receptor Kinase Inhibitor Bosutinib in Combination with Pemetrexed in Patients with Selected Metastatic Solid Tumors

Src is overexpressed in various cancers, including 27% of non-small cell lung cancer NSCLC, and is correlated with poor clinical outcomes. We hypothesize that Src kinase inhibitors, including Bosutinib, may exhibit clinical synergy in combination with the antifolate drug pemetrexed. In this Phase I, dose-escalation, safety, and maximum tolerated dose (MTD)-determining study, 14 patients with advanced metastatic solid tumors that had progressed on "standard of care" chemotherapy were enrolled in a 3 + 3 dose escalation study. Oral Bosutinib was administered once daily beginning on day 1, where the first cohort started at an oral dose of 200 mg daily with pemetrexed 500 mg/m² IV on a three-week schedule. The study's primary objective was to determine the dose-limiting toxicity (DLT), the MTD of Bosutinib in combination with pemetrexed, and the type and frequency of adverse events associated with this treatment. Twelve patients were evaluable for response, including ten patients with adenocarcinoma of the lung, one patient with metastatic adenocarcinoma of the appendix, and one patient with urothelial carcinoma. The median number of Bosutinib and pemetrexed cycles received was 4 (range, 1-4). The MTD of oral Bosutinib in this combination was 300 mg daily. Two patients (17%) had a partial response (PR), and seven patients (58%) showed stable disease (SD) as the best response after the fourth cycle (end of treatment). One patient had disease progression after the second cycle, while three patients had disease progression after the fourth cycle. The two responders and the two patients with the longest stable disease duration or stabilization of disease following progression on multiple systemic therapies demonstrated Src overexpression on immunohistochemical staining of their tumor. The median progression-free survival (PFS) was 6.89 months (95% CI (3.48, 30.85)), and the median overall survival (OS) was 11.7 months (95% CI (3.87, 30.85)). Despite the limitations of this Phase I study, there appears to be potential efficacy of this combination in previously treated patients.

Rapid Actions of the Nuclear Progesterone Receptor through cSrc in Cancer

The nuclear progesterone receptor (PR) is mainly known for its role as a ligand-regulated transcription factor. However, in the last ten years, this receptor’s extranuclear or rapid actions have gained importance in the context of physiological and pathophysiological conditions such as cancer. The PR’s polyproline (PXPP) motif allows protein–protein interaction through SH3 domains of several cytoplasmatic proteins, including the Src family kinases (SFKs). Among members of this family, cSrc is the most well-characterized protein in the scenario of rapid actions of the PR in cancer. Studies in breast cancer have provided the most detailed information on the signaling and effects triggered by the cSrc–PR interaction. Nevertheless, the study of this phenomenon and its consequences has been underestimated in other types of malignancies, especially those not associated with the reproductive system, such as glioblastomas (GBs). This review will provide a detailed analysis of the impact of the PR–cSrc interplay in the progression of some non-reproductive cancers, particularly, in GBs.

Nigericin exerts anticancer effects through inhibition of the SRC/STAT3/BCL-2 in osteosarcoma

The treatment of osteosarcoma has reached a bottleneck period in recent 30 years, there is an urgent need to find new drugs and treatment methods. Nigericin, an antibiotic derived from Streptomyces hygroscopicus, has exerted promising antitumoral effect in various tumors. The anticancer effect of Nigericin in human osteosarcoma has never been reported. In the present study, we explored the anticancer effects of Nigericin in osteosarcoma in vitro and in vivo. Our results showed that nigericin treatment significantly reduced tumor cell proliferation in dose-dependent and time-dependent in human osteosarcoma cells. Nigericin can inhibit cell growth of osteosarcoma cells, in addition to S-phase cycle arrest, the nigericin induces apoptosis. Furthermore, bioinformatics predicted that Nigericin exerts anticancer effects through inhibiting SRC/STAT3 signaling pathway in osteosarcoma. The direct binding between SRC and activator of transcription 3 (STAT3) was confirmed by Western blot. Nigericin can down regulate STAT3 and Bcl-2. In order to further elucidate the inhibitory effect of nigericin on SRC / STAT3 / Bcl-2 signal transduction mechanism, we established human osteosarcoma cancer cells stably expressing STAT3. Western blot confirmed that nigericin exerts anticancer effects on human osteosarcoma cancer cells by directly targeting STAT3. In addition, Nigericin can significantly inhibit tumor migration and invasion. Finally, Nigericin inhibits tumor growth in a mouse osteosarcoma model. The nigericin targeting the SRC/STAT3/BCL-2 signaling pathway may provide new insights into the molecular mechanism of nigericin on cancer cells and suggest its possible clinical application in osteosarcoma.

The paradox-breaking panRAF plus SRC family kinase inhibitor, CCT3833, is effective in mutant KRAS-driven cancers

BACKGROUND

KRAS is mutated in ∼90% of pancreatic ductal adenocarcinomas, ∼35% of colorectal cancers and ∼20% of non-small-cell lung cancers. There has been recent progress in targeting G12CKRAS specifically, but therapeutic options for other mutant forms of KRAS are limited, largely because the complexity of downstream signaling and feedback mechanisms mean that targeting individual pathway components is ineffective.

DESIGN

The protein kinases RAF and SRC are validated therapeutic targets in KRAS-mutant pancreatic ductal adenocarcinomas, colorectal cancers and non-small-cell lung cancers and we show that both must be inhibited to block growth of these cancers. We describe CCT3833, a new drug that inhibits both RAF and SRC, which may be effective in KRAS-mutant cancers.

RESULTS

We show that CCT3833 inhibits RAF and SRC in KRAS-mutant tumors in vitro and in vivo, and that it inhibits tumor growth at well-tolerated doses in mice. CCT3833 has been evaluated in a phase I clinical trial (NCT02437227) and we report here that it significantly prolongs progression-free survival of a patient with a G12VKRAS spindle cell sarcoma who did not respond to a multikinase inhibitor and therefore had limited treatment options.

CONCLUSIONS

New drug CCT3833 elicits significant preclinical therapeutic efficacy in KRAS-mutant colorectal, lung and pancreatic tumor xenografts, demonstrating a treatment option for several areas of unmet clinical need. Based on these preclinical data and the phase I clinical unconfirmed response in a patient with KRAS-mutant spindle cell sarcoma, CCT3833 requires further evaluation in patients with other KRAS-mutant cancers.

Development of the phenylpyrazolo[3,4-d]pyrimidine-based, insulin-like growth factor receptor/Src/AXL-targeting small molecule kinase inhibitor

Rationale: The type I insulin-like growth factor receptor (IGF-1R) signaling pathway plays key roles in the development and progression of numerous types of human cancers, and Src and AXL have been found to confer resistance to anti-IGF-1R therapies. Hence, co-targeting Src and AXL may be an effective strategy to overcome resistance to anti-IGF-1R therapies. However, pharmacologic targeting of these three kinases may result in enhanced toxicity. Therefore, the development of novel multitarget anticancer drugs that block IGF-1R, Src, and AXL is urgently needed.

Methods: We synthesized a series of phenylpyrazolo[3,4-d]pyrimidine (PP)-based compounds, wherein the PP module was conjugated with 2,4-bis-arylamino-1,3-pyrimidines (I2) via a copper(I)-catalyzed alkyne-azide cycloaddition reaction. To develop IGF-1R/Src/AXL-targeting small molecule kinase inhibitors, we selected LL6 as an active compound and evaluated its antitumor and antimetastatic effects in vitro and in vivo using the MTT assay, colony formation assays, migration assay, flow cytometric analysis, a tumor xenograft model, the Kras^G12D/+-driven spontaneous lung tumorigenesis model, and a spontaneous metastasis model using Lewis lung carcinoma (LLC) allografts. We also determined the toxicity of LL6 in vitro and in vivo.

Results: LL6 induced apoptosis and suppressed viability and colony-forming capacities of various non-small cell lung cancer (NSCLC) cell lines and their sublines with drug resistance. LL6 also suppressed the migration of NSCLC cells at nontoxic doses. Administration of LL6 in mice significantly suppressed the growth of NSCLC xenograft tumors and metastasis of LLC allograft tumors with outstanding toxicity profiles. Furthermore, the multiplicity, volume, and load of lung tumors in Kras^G12D/+ transgenic mice were substantially reduced by the LL6 treatment.

Conclusions: Our results show the potential of LL6 as a novel IGF-1R/Src/AXL-targeting small molecule kinase inhibitor, providing a new avenue for anticancer therapies.

Phosphorylation of PLCγ1 by EphA2 Receptor Tyrosine Kinase Promotes Tumor Growth in Lung Cancer

EphA2 receptor tyrosine kinase (RTK) is often expressed at high levels in cancer and has been shown to regulate tumor growth and metastasis across multiple tumor types, including non-small cell lung cancer. A number of signaling pathways downstream of EphA2 RTK have been identified; however, mechanisms of EphA2 proximal downstream signals are less well characterized. In this study, we used a yeast-two-hybrid screen to identify phospholipase C gamma 1 (PLCγ1) as a novel EphA2 interactor. EphA2 interacts with PLCγ1 and the kinase activity of EphA2 was required for phosphorylation of PLCγ1. In human lung cancer cells, genetic or pharmacologic inhibition of EphA2 decreased phosphorylation of PLCγ1 and loss of PLCγ1 inhibited tumor cell growth in vitro. Knockout of PLCγ1 by CRISPR-mediated genome editing also impaired tumor growth in a KrasG12D-p53-Lkb1 murine lung tumor model. Collectively, these data show that the EphA2-PLCγ1 signaling axis promotes tumor growth of lung cancer and provides rationale for disruption of this signaling axis as a potential therapeutic option. IMPLICATIONS: The EphA2-PLCG1 signaling axis promotes tumor growth of non-small cell lung cancer and can potentially be targeted as a therapeutic option.

Integrative Analysis of Membrane Proteome and MicroRNA Reveals Novel Lung Cancer Metastasis Biomarkers

Lung cancer is one of the most common human cancers both in incidence and mortality, with prognosis particularly poor in metastatic cases. Metastasis in lung cancer is a multifarious process driven by a complex regulatory landscape involving many mechanisms, genes, and proteins. Membrane proteins play a crucial role in the metastatic journey both inside tumor cells and the extra-cellular matrix and are a viable area of research focus with the potential to uncover biomarkers and drug targets. In this work we performed membrane proteome analysis of highly and poorly metastatic lung cells which integrated genomic, proteomic, and transcriptional data. A total of 1,762 membrane proteins were identified, and within this set, there were 163 proteins with significant changes between the two cell lines. We applied the Tied Diffusion through Interacting Events method to integrate the differentially expressed disease-related microRNAs and functionally dys-regulated membrane protein information to further explore the role of key membrane proteins and microRNAs in multi-omics context. Has-miR-137 was revealed as a key gene involved in the activity of membrane proteins by targeting MET and PXN, affecting membrane proteins through protein-protein interaction mechanism. Furthermore, we found that the membrane proteins CDH2, EGFR, ITGA3, ITGA5, ITGB1, and CALR may have significant effect on cancer prognosis and outcomes, which were further validated in vitro. Our study provides multi-omics-based network method of integrating microRNAs and membrane proteome information, and uncovers a differential molecular signatures of highly and poorly metastatic lung cancer cells; these molecules may serve as potential targets for giant-cell lung metastasis treatment and prognosis.

Quercetin Inhibits the Proliferation and Metastasis of Human Non-Small Cell Lung Cancer Cell Line: The Key Role of Src-Mediated Fibroblast Growth Factor-Inducible 14 (Fn14)/ Nuclear Factor kappa B (NF-κB) pathway

Background

Quercetin (Que) is reported to induce apoptosis of lung cancer cells. Src is closely related to the progression of non-small cell lung cancer (NSCLC) and can be modulated by Que in macrophages. In the current study, the interaction between Que and Src signaling in NSCLC cells was explored to explain the anti-NSCLC function of Que.

Material/Methods

NSCLC cell line HCC827 was subjected to the administrations of Que at different concentrations. The effect of Que on tumor cell proliferation was detected using MTT and colony formation assays. Then the effect on the migration and invasion abilities was assessed using scratch and Transwell assays. At molecular level, the changes in Src/Fn14/NF-κB signaling were determined using western blotting assays. The role of Src in the function of Que was further explored by inducing the expression of Src gene in NSCLC cells before Que administration. The results of the in vitro assays were verified using a NSCLC mice model.

Results

Que inhibited the proliferation and anchorage-independent growth of NSCLC cells. Additionally, Que delayed in the gap closure rate in scratch assays and decreased the membrane-penetrating cell number in Transwell assays. At a molecular level, Que suppressed the expression of Src, which subsequently inhibited Fn14/NF-κB signaling. In in vivo assays, Que inhibited the growth of solid tumors. After the overexpression of Src in NSCLC cells, the anti-NSCLC effect of Que was blocked by inducing NSCLC proliferation and metastasis, and by activating Fn14/NF-κB signaling. Moreover, the induced level of Src promoted the growth and metastasis potential of solid tumors in mice.

Conclusions

Que exerted the anti-NSCLC effect by inhibiting Src-mediated Fn14/NF-κB pathway both in vitro and in vivo.

Structure-Based Design of a Potent and Selective Covalent Inhibitor for SRC Kinase That Targets a P-Loop Cysteine

SRC is a major regulator of many signaling pathways and contributes to cancer development. However, development of a selective SRC inhibitor has been challenging, and FDA-approved SRC inhibitors, dasatinib and bosutinib, are multitargeted kinase inhibitors. Here, we describe our efforts to develop a selective SRC covalent inhibitor by targeting cysteine 277 on the P-loop of SRC. Using a promiscuous covalent kinase inhibitor (CKI) SM1-71 as a starting point, we developed covalent inhibitor 15a, which discriminates SRC from other covalent targets of SM1-71 including TAK1 and FGFR1. As an irreversible covalent inhibitor, compound 15a exhibited sustained inhibition of SRC signaling both in vitro and in vivo. Moreover, 15a exhibited potent antiproliferative effects in nonsmall cell lung cancer cell lines harboring SRC activation, thus providing evidence that this approach may be promising for further drug development efforts.

Lusianthridin targeting of lung cancer stem cells via Src-STAT3 suppression

BACKGROUND

Cancer stem cells (CSCs) are well-recognized as a majority cause of treatment failure and can give rise to relapse. The discovery of compounds attenuating CSCs' properties is crucial for enabling advances in novel therapeutics to limit recurrence. CSCs' features in lung cancer are regulated through a reduction in Src-STAT3-c-Myc, which drives cancer progression, drug resistance, and metastasis.

METHODS

The effect of lusianthridin suppresses CSC-like phenotypes was determined by 3D culture and anchorage independent growth. The expression of CSC markers and associated proteins were determined by Western blot analyses. Protein ubiquitination and degradation were assessed using immunoprecipitation.

RESULTS

Herein, we report that lusianthridin, a pure compound from Dendrobium venustum, dramatically suppressed CSCs in lung cancer cells as verified by several CSC phenotype assessments and CSC markers. The CSC phenotypes in lusianthridin-treated cells were suppressed through downregulation of Src-STAT3-c-Myc pathways. Ectopic Src introduced by the transfection augmented CSC phenotypes in lung cancer cells through STAT3 (increased active p-STAT3^Tyr705) and c-Myc signals, while the ShRNA-Src transfection or Src inhibitor dasatinib exhibited opposite results. Treatment of the Src-overexpressing cells with lusianthridin resulted in the reversal of active STAT3 (p-STAT3^Tyr705) and c-Myc as well as the CSC marker CD133. Importantly, we confirmed the CSC-targeted activity of lusianthridin in CSC-rich primary lung cancer cells. The compound dramatically inhibited the formation of tumor spheres of primary lung cancer cells. Finally, we demonstrated that after CSC-attenuation by lusianthridin, the lung cancer cells exhibited significantly higher susceptibility to chemotherapeutic drugs. Such a sensitizing effect caused by pro-survival suppression and pro-apoptotic induction together with the abolishment of stemness indicated by the decrease in CSC markers CD133, ABCG2, and ALDH1A1.

CONCLUSION

These findings revealed a novel pharmacological action and the underlying mechanism of lusianthridin in negatively regulating CSC-like phenotypes and sensitizing resistant cancer cells to cemetery.

Deep Learning Enhancing Kinome-Wide Polypharmacology Profiling: Model Construction and Experiment Validation

The kinome-wide virtual profiling of small molecules with high-dimensional structure-activity data is a challenging task in drug discovery. Here, we present a virtual profiling model against a panel of 391 kinases based on large-scale bioactivity data and the multitask deep neural network algorithm. The obtained model yields excellent internal prediction capability with an auROC of 0.90 and consistently outperforms conventional single-task models on external tests, especially for kinases with insufficient activity data. Moreover, more rigorous experimental validations including 1410 kinase-compound pairs showed a high-quality average auROC of 0.75 and confirmed many novel predicted "off-target" activities. Given the verified generalizability, the model was further applied to various scenarios for depicting the kinome-wide selectivity and the association with certain diseases. Overall, the computational model enables us to create a comprehensive kinome interaction network for designing novel chemical modulators or drug repositioning and is of practical value for exploring previously less studied kinases.

Scutellaria Flavonoids Effectively Inhibit the Malignant Phenotypes of Non-small Cell Lung Cancer in an Id1-dependent Manner

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death in the world. Inhibitor of differentiation 1 (Id1) is overexpressed in NSCLC and involved in promoting its progression and metastasis. Identifying natural compounds targeting Id1 may have utility in NSCLC treatment. Here, we sought to determine whether the anti-tumor activities of Scutellaria flavonoids (SFs) were related to Id1. We reported that three SFs (baicalin, baicalein and wogonin) exhibited strong antitumor activity in NSCLC cells in vitro and in vivo. Id1 played a pivotal role on blockage of migration and invasion by SFs. Abrogation of invasion and migration mediated by baicalin, baicalein and wogonin were totally abolished by ectopic overexpression of Id1. Mechanistically, baicalin, baicalein and wogonin activated Rap1-GTP binding and dephosphorylated Akt and Src by suppressing a7nAChR, consequently triggering inhibition of Id1. Then attenuation of its downstream mediators, VEGF-A, N-cadherin, vimentin, combined with augment of E-cadherin led to the blockage of proliferation, EMT and angiogenesis of NSCLC. Overall, our data shed light on heretofore-undescribed role of SFs as modulators of Id1, which may be a useful strategy in the treatment of NSCLC.

Correlation between image characteristics and pathologic findings in non small cell lung cancer patients after anatomic resection

Introduction

Tumor characteristics in computed tomography (CT) are correlated to pathologic presentation and survival. However, most studies have been based on thin slice thickness CT while lymph node metastatic pattern has remained unclear. The aim of this study was to analyze the correlation between image characteristics under 5 mm slice thickness and pathology findings in non small lung cancer patients who have received curative resection.

Materials and methods

From January 2010 to May 2014, 440 patients who underwent curative resection were included and medical records were reviewed retrospectively. The tumor size and consolidation tumor ratio were simultaneously evaluated and measured by a physician, a thoracic surgeon, and a radiologist. The correlation between image and pathology characteristics and its survival impact was analyzed.

Results

Tumor sizes, as measured by CT and by pathologic measurement were highly coincident. (p < 0.001) GGO predominant lesions were correlated to well-differentiated adenocarcinoma, (p< 0.001), and less tumor necrosis (p<0.0001), lymphocyte infiltration (p = 0.0042) and tumor purity (p <0.0001). In addition, less risk of visceral pleura (p < 0.0001) and angiolymphatic invasion, and fewer metastases to N1 lymph node (p = 0.004) involvement were identified. No lymph node metastasis (0/12) was identified in sub-centimeter pure GGO lesion. The consolidation tumor ratio could be used to differentiate patients’ survival and excellent 5-year overall survival was identified in pure GGO lesion cases.

Conclusion

No lymph node metastasis was identified in sub-centimeter pure GGO lesion. The consolidation tumor ratio could be used to differentiate patients’ disease status and overall survival, while excellent 5-year overall survival was identified in cases with pure GGO lesion.

Tyrosine kinase inhibitor-induced IL-6/STAT3 activation decreases sensitivity of EGFR-mutant non-small cell lung cancer to icotinib

Tyrosine kinase Inhibitors (TKIs) of epidermal growth factor receptor (EGFR) has considerably benefited for non-small cell lung carcinomas (NSCLC) harbor mutations in EGFR. However, the factors attenuating EGFR-TKI efficiency are obstacles to inhibit the proliferation of EGFR-mutant NSCLC cells successfully. Clarifying the insensitivity mechanisms of EGFR-TKI would help to develop new treatment strategy. In this study, the sensitivity of EGFR-mutant NSCLC cell lines, PC9 and HCC827, to icotinib was detected. Similar with other EGFR-TKIs such as gefitinib and erlortinib in previous research, the proliferation of two cell lines was apparently inhibited. However, we surprisingly found that contrast with the suppression of EGFR-AKT/ERK pathway, STAT3 was significantly activated in PC9 cells with the treatment of icotinib, but not in HCC827 cells. Further study confirmed that icotinib concomitantly induced IL-6 secretion and src activation in PC9 cells. Moreover, with the treatment of IL-6 neutralizing antibody or src inhibitor, dasatinib, icotinib-induced phosphorylation of STAT3 was reduced, as well as the sensitivity of PC9 to icotinib was also partially increased. Our results suggest that Src/IL-6/STAT3 bypass pathway is activated to maintain cell survival when the EGFR pathway was inhibited by TKIs, even in some EGFR-mutant NSCLC cells sensitive to TKIs. This finding provides a groundwork for potential combinatorial treatment with TKIs and Src or STAT3 inhibitor to improve icotinib sensitivity.

YAP and TAZ in Lung Cancer: Oncogenic Role and Clinical Targeting

Lung cancer is the leading cause of cancer death in the world and there is no current treatment able to efficiently treat the disease as the tumor is often diagnosed at an advanced stage. Moreover, cancer cells are often resistant or acquire resistance to the treatment. Further knowledge of the mechanisms driving lung tumorigenesis, aggressiveness, metastasization, and resistance to treatments could provide new tools for detecting the disease at an earlier stage and for a better response to therapy. In this scenario, Yes Associated Protein (YAP) and Trascriptional Coactivator with PDZ-binding motif (TAZ), the final effectors of the Hippo signaling transduction pathway, are emerging as promising therapeutic targets. Here, we will discuss the most recent advances made in YAP and TAZ biology in lung cancer and, more importantly, on the newly discovered mechanisms of YAP and TAZ inhibition in lung cancer as well as their clinical implications.

Src activation decouples cell division orientation from cell geometry in mammalian cells

Orientation of cell division plane plays a crucial role in morphogenesis and regeneration. Misoriented cell division underlies many important diseases, such as cancer. Studies with Drosophila and C. elegance models show that Src, a proto-oncogene tyrosine-protein kinase, is a critical regulator of this aspect of mitosis. However, the role for Src in controlling cell division orientation in mammalian cells is not well understood. Using genetic and pharmacological approaches and two extracellular signals to orient cell division, we demonstrated a critical role for Src. Either knockout or pharmacological inhibition of Src would retain the fidelity of cell division orientation with the long-axis orientation of mother cells. Conversely, re-expression of Src would decouple cell division orientation from the pre-division orientation of the long axis of mother cells. Cell division orientation in human breast and gastric cancer tissues showed that the Src activation level correlated with the degree of mitotic spindle misorientation relative to the apical surface. Examination of proteins associated with cortical actin revealed that Src activation regulated the accumulation and local density of adhesion proteins on the sites of cell-matrix attachment. By analyzing division patterns in the cells with or without Src activation and through use of a mathematical model, we further support our findings and provide evidence for a previously unknown role for Src in regulating cell division orientation in relation to the pre-division geometry of mother cells, which may contribute to the misoriented cell division.

Molecular mechanism of action and potential biomarkers of growth inhibition of synergistic combination of afatinib and dasatinib against gefitinib-resistant non-small cell lung cancer cells

Epidermal growth factor receptor - tyrosine kinase inhibitor (EGFR-TKI) is the first choice of treatment for advanced non-small cell lung cancer (NSCLC) patients harbouring activating EGFR mutations. However, single agent usually has limited efficacy due to heterogeneous resistant mechanisms of cancer cells. Thus drug combination therapy would offer more benefits by synergistic interactions and avoidance of resistance emergence. In this study, we selected 8 NSCLC cell lines with different genetic characteristics as research models to investigate the efficacy of 4 agents (gefitinib, cetuximab, afatinib and dasatinib) and their combinations. As a single agent, both afatinib and dasatinib showed more inhibition against cell proliferation than gefitinib and cetuximab. Afatinib combined with dasatinib demonstrated significantly high efficacy against 7 gefitinib-resistant NSCLC cell lines. Moreover, it reversed the resistance to the 4 studied single agents in PTEN mutated NSCLC cells. By studying the activity of EGFR, Src and their downstream signalling pathways including PI3K/PTEN/Akt, Ras/Raf/MEK/ERK, Src/FAK and JAK/Stat, we demonstrated the synergistic interaction between afatinib and dasatinib was not only due to their blockage of different signalling pathways but also the complemental inhibition of the related signalling molecules such as Stat3. We also found that the level of Src, Stat3, and MAPK may be useful biomarkers predicating synergism between afatinib and dasatinib for the treatment of gefitinib-resistant NSCLC cells.

Src Promotes Metastasis of Human Non-Small Cell Lung Cancer Cells through Fn14-Mediated NF-κB Signaling

Background

Src and Fn14 are implicated in the aggressiveness of non-small cell lung cancer (NSCLC) cells, yet the molecular mechanism is not fully understood.

Material/Methods

The proliferation, migration, and invasion of HCC827 cells with Src knockdown were examined in vitro. The expression of Fn14 and the activation of NF-κB signaling pathway in Src-silenced HCC827 cells were detected by western blot. The role of Fn14 in Src-regulated cell migration/invasion and activation of NF-κB signaling was investigated by overexpressing Fn14 in Src knockdown NSCLC cells. Furthermore, the pro-metastatic role of Src was validated in a NSCLC metastasis mouse model.

Results

Knockdown of Src inhibited the proliferation, migration, and invasion of HCC827 cells, which was associated with reduced levels of Fn14, p-IκBα, p-IKKβ, and nuclear NF-κB p65. Overexpression of Fn14 restored the potential of migration and invasion as well as the activation of NF-κB signaling in Src-silenced NSCLC cells. In addition, silencing of Src suppressed lung metastasis of HCC827 cells in mice, and inhibited the expression of Fn14 and nuclear translocation of NF-κB p65 in vivo.

Conclusions

The data demonstrated that the Src/Fn14/NF-κB axis plays a critical role in NSCLC metastasis.

Target therapy: new drugs or new combinations of drugs in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a disease with a poor prognosis due to its aggressive nature. The management of patients with MPM is controversial. Considering that the contribution of surgery and radiation therapy in the management of this disease is not yet established, systemic treatments are predominantly considered during the course of MPM. Unfortunately, the currently therapeutic armamentarium is scarce and its outcomes still appear modest. New treatment strategies are needed. In preclinical setting, cell cycle regulation, apoptosis, growth factor pathways, and angiogenesis pathways involved in the development of MPM have been identified. However, in clinical setting, several drugs targeting these pathways resulted without a significant activity. A deeper knowledge of the biology and pathogenesis of this disease is required to develop more effective tools for diagnosis, therapy and prevention. This paper reviews therapeutic advances in MPM, with a particular focus on new drugs and new association of drugs of target therapy.

Preclinical pharmacodynamic evaluation of drug candidate SKLB-178 in the treatment of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is a serious life-threatening malignancy. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, such as Gefitinib and Erlotinib, are effective clinical medicines for advanced NSCLC patients harboring EGFR-activating mutations. However, this therapy just benefits a small percentage of sufferers. Worse still, all patients treated with drugs ultimately develop resistance. Hence, there is still an unmet medical need among patients with NSCLC. In this account, we report a novel multikinase inhibitor SKLB-178, which potently inhibits both EGFR-activating and resistant mutations, as well as the activities of Src and VEGFR2 kinases. SKLB-178 potently inhibited cancer cell growth in both Gefitinib-sensitive and resistant NSCLC cells. Meanwhile, SKLB-178 significantly suppressed the migration, invasion and tube formation of endothelial cells, and the growth of intersegmental vessel in zebrafish. The in vivo pharmacodynamic studies further demonstrated that SKLB-178 had wider potency than Gefitinib, and could significantly prolong survival of animals in A549 experimental metastasis model. These advantages together with the low toxicity of SKLB-178 indicate that SKLB-178 deserves to be further developed as a potential drug candidate for NSCLC therapy.

Enhancement of the anti-tumor activity of FGFR1 inhibition in squamous cell lung cancer by targeting downstream signaling involved in glucose metabolism

Fibroblast Growth Factor Receptor (FGFR) signaling is a complex pathway which controls several processes, including cell proliferation, survival, migration, and metabolism. FGFR1 signaling is frequently deregulated via amplification/over-expression in NSCLC of squamous histotype (SQCLC), however its inhibition has not been successfully translated in clinical setting. We determined whether targeting downstream signaling implicated in FGFR1 effects on glucose metabolism potentiates the anti-tumor activity of FGFR1 inhibition in SQCLC. In FGFR1 amplified/over-expressing SQCLC cell lines, FGF2-mediated stimulation of FGFR1 under serum-deprivation activated both MAPK and AKT/mTOR pathways and increased glucose uptake, glycolysis, and lactate production, through AKT/mTOR-dependent HIF-1α accumulation and up-regulation of GLUT-1 glucose transporter. These effects were hindered by PD173074 and NVP-BGJ398, selective FGFR inhibitors, as well as by dovitinib, a multi-kinase inhibitor. Glucose metabolism was hampered by the FGFR inhibitors also under hypoxic conditions, with consequent inhibition of cell proliferation and viability. In presence of serum, glucose metabolism was impaired only in cell models in which FGFR1 inhibition was associated with AKT/mTOR down-regulation. When the activation of the AKT/mTOR pathway persisted despite FGFR1 down-regulation, the efficacy of NVP-BGJ398 could be significantly improved by the combination with NVP-BEZ235 or other inhibitors of this signaling cascade, both in vitro and in xenotransplanted nude mice. Collectively our results indicate that inhibition of FGFR1 signaling impacts on cancer cell growth also by affecting glucose energy metabolism. In addition, this study strongly suggests that the therapeutic efficacy of FGFR1 targeting molecules in SQCLC may be implemented by combined treatments tackling on glucose metabolism.

Rhodomycin A, a novel Src-targeted compound, can suppress lung cancer cell progression via modulating Src-related pathways

Src activation is involved in cancer progression and the interplay with EGFR. Inhibition of Src activity also represses the signalling pathways regulated by EGFR. Therefore, Src has been considered a target molecule for drug development. This study aimed to identify the compounds that target Src to suppress lung cancer tumourigenesis and metastasis and investigate their underlying molecular mechanisms. Using a molecular docking approach and the National Cancer Institute (NCI) compound dataset, eight candidate compounds were selected, and we evaluated their efficacy. Among them, rhodomycin A was the most efficient at reducing the activity and expression of Src in a dose-dependent manner, which was also the case for Src-associated proteins, including EGFR, STAT3, and FAK. Furthermore, rhodomycin A significantly suppressed cancer cell proliferation, migration, invasion, and clonogenicity in vitro and tumour growth in vivo. In addition, rhodomycin A rendered gefitinib-resistant lung adenocarcinoma cells more sensitive to gefitinib treatment, implying a synergistic effect of the combination therapy. Our data also reveal that the inhibitory effect of rhodomycin A on lung cancer progression may act through suppressing the Src-related multiple signalling pathways, including PI3K, JNK, Paxillin, and p130cas. These findings will assist the development of anti-tumour drugs to treat lung cancer.

The N-terminus of survivin is a mitochondrial-targeting sequence and Src regulator

Survivin (also known as BIRC5) is a cancer-associated protein that exists in several locations in the cell. Its cytoplasmic residence in interphase cells is governed by CRM1 (also known as XPO1)-mediated nuclear exportation, and its localisation during mitosis to the centromeres and midzone microtubules is that of a canonical chromosomal passenger protein. In addition to these well-established locations, survivin is also a mitochondrial protein, but how it gets there and its function therein is presently unclear. Here, we show that the first ten amino acids at the N-terminus of survivin are sufficient to target GFP to the mitochondria in vivo, and ectopic expression of this decapeptide decreases cell adhesion and accelerates proliferation. The data support a signalling mechanism in which this decapeptide regulates the tyrosine kinase Src, leading to reduced focal adhesion plaques and disruption of F-actin organisation. This strongly suggests that the N-terminus of survivin is a mitochondrial-targeting sequence that regulates Src, and that survivin acts in concert with Src to promote tumorigenesis.

Identification of gene markers in the development of smoking-induced lung cancer

Lung cancer is a malignant tumor with high mortality in both women and men. To study the mechanisms of smoking-induced lung cancer, we analyzed microarray of GSE4115. GSE4115 was downloaded from Gene Expression Omnibus including 78 and 85 bronchial epithelium tissue samples separately from smokers with and without lung cancer. Limma package in R was used to screen differentially expressed genes (DEGs). Hierarchical cluster analysis for DEGs was conducted using orange software and visualized by distance map. Using DAVID software, functional and pathway enrichment analyses separately were conducted for the DEGs. And protein-protein interaction (PPI) network was constructed using Cytoscape software. Then, the pathscores of enriched pathways were calculated. Besides, functional features were screened and optimized using the recursive feature elimination (RFE) method. Additionally, the support vector machine (SVM) method was used to train model. Total 1923 DEGs were identified between the two groups. Hierarchical cluster analysis indicated that there were differences in gene level between the two groups. And SVM analysis indicated that the five features had potential diagnostic value. Importantly, MAPK1 (degree=30), SRC (degree=29), SMAD4 (degree=23), EEF1A1 (degree=21), TRAF2 (degree=21) and PLCG1 (degree=20) had higher degrees in the PPI network of the DEGs. They might be involved in smoking-induced lung cancer by interacting with each other (e.g. MAPK1-SMAD4, SMAD4-EEF1A1 and SRC-PLCG1). MAPK1, SRC, SMAD4, EEF1A1, TRAF2 and PLCG1 might be responsible for the development of smoking-induced lung cancer.

Src regulates cigarette smoke-induced ceramide generation via neutral sphingomyelinase 2 in the airway epithelium

We previously demonstrated that the neutral sphingomyelinase (nSMase) 2 is the sole sphingomyelinase activated during cigarette smoke (CS)-induced oxidative stress of human airway epithelial cells, leading to ceramide generation and subsequent apoptosis of affected cells. Since then, we reported that nSMase2 is a phosphoprotein, the degree of enzymatic activity and stability of which are dictated by its degree of phosphorylation. Simultaneously, the non-receptor tyrosine kinase and proto-oncogene Src has increasingly become a target of interest in both smoking-related lung injury, such as chronic obstructive pulmonary disease, and lung cancer. Within this context, we tested and now present Src as a regulator of ceramide generation via modulation of nSMase2 phosphorylation and activity during CS-induced oxidative stress. Specifically, we provide evidence that Src activity is necessary for both CS-induced ceramide accumulation in vivo (129/Sv mice) and in vitro (human airway epithelial cells) and for nSMase2 activity during CS-induced oxidative stress. Moreover, because nSMase2 is exclusively phosphorylated on serines, we show that this occurs through Src-dependent activation of the serine/threonine kinase p38 mitogen-activated protein kinase during oxidative stress. Finally, we provide evidence that Src and p38 mitogen-activated protein kinase activities are critical for regulating nSMase2 phosphorylation. This study provides insights into a molecular target involved in smoking-related lung injury, represented here as nSMase2, and its modulation by the oncogene Src.

Targeting the insulin-like growth factor receptor and Src signaling network for the treatment of non-small cell lung cancer

Background

Therapeutic interventions in the insulin-like growth factor receptor (IGF-1R) pathway were expected to provide clinical benefits; however, IGF-1R tyrosine kinase inhibitors (TKIs) have shown limited antitumor efficacy, and the mechanisms conveying resistance to these agents remain elusive.

Methods

The expression and activation of the IGF-1R and Src were assessed via the analysis of a publicly available dataset, as well as immunohistochemistry, Western blotting, RT-PCR, and in vitro kinase assays. The efficacy of IGF-1R TKIs alone or in combination with Src inhibitors was analyzed using MTT assays, colony formation assays, flow cytometric analysis, and xenograft tumor models.

Results

The co-activation of IGF-1R and Src was observed in multiple human NSCLC cell lines as well as in a tissue microarray (n = 353). The IGF-1R and Src proteins mutually phosphorylate on their autophosphorylation sites. In high-pSrc-expressing NSCLC cells, linsitinib treatment initially inactivated the IGF-1R pathway but led a Src-dependent reactivation of downstream effectors. In low-pSrc-expressing NSCLC cells, linsitinib treatment decreased the turnover of the IGF-1R and Src proteins, ultimately amplifying the reciprocal co-activation of IGF-1R and Src. Co-targeting IGF-1R and Src significantly suppressed the proliferation and tumor growth of both high-pSrc-expressing and low-pSrc-expressing NSCLC cells in vitro and in vivo and the growth of patient-derived tissues in vivo.

Conclusions

Reciprocal activation between Src and IGF-1R occurs in NSCLC. Src causes IGF-1R TKI resistance by acting as a key downstream modulator of the cross-talk between multiple membrane receptors. Targeting Src is a clinically applicable strategy to overcome resistance to IGF-1R TKIs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0392-3) contains supplementary material, which is available to authorized users.

Emerging Role and Targeting of Carcinoembryonic Antigen-related Cell Adhesion Molecule 6 (CEACAM6) in Human Malignancies

BACKGROUND

Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is a member of the CEA family of cell adhesion proteins that belong to the immunoglobulin superfamily. CEACAM6 is normally expressed on the surface of myeloid (CD66c) and epithelial surfaces. Stiochiomertic expression of members of the CEA family (CEACAM1, 5, 6, 7) on epithelia maintains normal tissue architecture through homo-and hetero-philic interactions. Dysregulated over-expression of CEACAM6 is oncogenic, is associated with anoikis resistance and an invasive phenotype mediated by excessive TGFβ, AKT, FAK and SRC signaling in human malignancies.

METHODS

Extensive literature review through PubMed was conducted to identify relevant preclinical and clinical research publications regarding CEACAM6 over the last decade and was summarized in this manuscript.

RESULTS

CEACAM5 and 6 are over-expressed in nearly 70% of epithelial malignancies including colorectal cancer (CRC), pancreatic ductal adenocarcinoma (PDA), hepatobiliary, gastric, breast, non-small cell lung and head/neck cancers. Importantly, CEACAM6 is a poor prognostic marker in CRC, while its expression correlates with tumor stage, metastasis and post-operative survival in PDA. CEACAM6 appears to be an immune checkpoint suppressor in hematologic malignancies including acute lymphoblastic leukemia and multiple myeloma. Several therapeutic monoclonal antibodies or antibody fragments targeting CEACAM6 have been designed and developed as a targeted therapy for human malignancies. A Llama antibody targeting CEACAM6 is being evaluated in early phase clinical trials.

CONCLUSION

This review focuses on the role of CEACAM6 in the pathogenesis and signaling of the malignant phenotype in solid and hematologic malignancies and highlights its potential as a therapeutic target for anti-cancer therapy.

Lung injury and lung cancer caused by cigarette smoke-induced oxidative stress: Molecular mechanisms and therapeutic opportunities involving the ceramide-generating machinery and epidermal growth factor receptor

Chronic obstructive pulmonary disease (COPD) and lung cancer are frequently caused by tobacco smoking. However, these diseases present opposite phenotypes involving redox signaling at the cellular level. While COPD is characterized by excessive airway epithelial cell death and lung injury, lung cancer is caused by uncontrolled epithelial cell proliferation. Notably, epidemiological studies have demonstrated that lung cancer incidence is significantly higher in patients who have preexisting emphysema/lung injury. However, the molecular link and common cell signaling events underlying lung injury diseases and lung cancer are poorly understood. This review focuses on studies of molecular mechanism(s) underlying smoking-related lung injury (COPD) and lung cancer. Specifically, the role of the ceramide-generating machinery during cigarette smoke-induced oxidative stress leading to both apoptosis and proliferation of lung epithelial cells is emphasized. Over recent years, it has been established that ceramide is a sphingolipid playing a major role in lung epithelia structure/function leading to lung injury in chronic pulmonary diseases. However, new and unexpected findings draw attention to its potential role in lung development, cell proliferation, and tumorigenesis. To address this dichotomy in detail, evidence is presented regarding several protein targets, including Src, p38 mitogen-activated protein kinase, and neutral sphingomyelinase 2, the major sphingomyelinase that controls ceramide generation during oxidative stress. Furthermore, their roles are presented not only in apoptosis and lung injury but also in enhancing cell proliferation, lung cancer development, and resistance to epidermal growth factor receptor-targeted therapy for treating lung cancer.

Tissue Expression of Low and High Molecular Weight Cytokeratins in Lung Carcinoma Sections: Its Correlation with Some Clinic-Pathological Features

The tissue expression of low (LMW) and high (HMW) molecular weight cytokeratins and Ber-EP4 antigen in both small (SCLC) and non-small (NSCLC) cell lung carcinomas, as well as its correlation with a variety of clinic-pathological features, was evaluated. In general, 43/52 (82.7%) of NSCLC sections showed the expression of at least one type of cytokeratin while only 7/16 (43.7%) of SCLC were stained with both LMW cytokeratin and pan-cytokeratins antibodies. Remarkably, 18/52 (34.6%) of NSCLC were positive to both types of cytokeratins. However, none of SCLC showed this pattern of expression. In NSCLC patients, the increasing levels of HMW cytokeratins expression, as shown by 34βE12 antibody, correlated with the occurrence of disease recurrence (P=0.0057; Fisher’s exact test). Consequently, the expression of HMW cytokeratins was found to be associated with a poor 4-year overall survival of NSCLC patients (P=0.0315; Log rank test), not taking into account the histopathological classification of tumors. Similar results were obtained when 8-year overall survival was assessed (P=0.0103; Log rank test). Our results could suggest the assessment of HMW cytokeratins in a larger series of NSCLC samples in order to confirm the potential prognostic value of them.

Bioinformatic approaches to augment study of epithelial-to-mesenchymal transition in lung cancer

Bioinformatic approaches are intended to provide systems level insight into the complex biological processes that underlie serious diseases such as cancer. In this review we describe current bioinformatic resources, and illustrate how they have been used to study a clinically important example: epithelial-to-mesenchymal transition (EMT) in lung cancer. Lung cancer is the leading cause of cancer-related deaths and is often diagnosed at advanced stages, leading to limited therapeutic success. While EMT is essential during development and wound healing, pathological reactivation of this program by cancer cells contributes to metastasis and drug resistance, both major causes of death from lung cancer. Challenges of studying EMT include its transient nature, its molecular and phenotypic heterogeneity, and the complicated networks of rewired signaling cascades. Given the biology of lung cancer and the role of EMT, it is critical to better align the two in order to advance the impact of precision oncology. This task relies heavily on the application of bioinformatic resources. Besides summarizing recent work in this area, we use four EMT-associated genes, TGF-β (TGFB1), NEDD9/HEF1, β-catenin (CTNNB1) and E-cadherin (CDH1), as exemplars to demonstrate the current capacities and limitations of probing bioinformatic resources to inform hypothesis-driven studies with therapeutic goals.

SRC kinase is a novel therapeutic target in lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a progressive cystic lung disease affecting some women with tuberous sclerosis complex (TSC). Sporadic LAM can develop in women without TSC, owing to somatic mutations in the TSC2 gene. Accumulating evidence supports the view of LAM as a low-grade, destructive, metastasizing neoplasm. The mechanisms underlying the metastatic capability of LAM cells remain poorly understood. The observed behavior of LAM cells with respect to their infiltrative growth pattern, metastatic potential, and altered cell differentiation bears similarity to cells undergoing epithelial-mesenchymal transition. Here, we report increased levels of active Src kinase in LAM lungs and in TSC2(-/-) cells, caused by a reduction of autophagy. Furthermore, increased Src kinase activation promoted migration, invasion, and inhibition of E-cadherin expression in TSC2(-/-) cells by upregulating the transcription factor Snail. Notably, Src kinase inhibitors reduced migration and invasion properties of TSC2(-/-) cells and attenuated lung colonization of intravenously injected TSC2(-/-) cells in vivo to a greater extent than control TSC2(+/+) cells. Our results reveal mechanistic basis for the pathogenicity of LAM cells and they rationalize Src kinase as a novel therapeutic target for treatment of LAM and TSC.

Loss of connectivity in cancer co-expression networks

Differential gene expression profiling studies have lead to the identification of several disease biomarkers. However, the oncogenic alterations in coding regions can modify the gene functions without affecting their own expression profiles. Moreover, post-translational modifications can modify the activity of the coded protein without altering the expression levels of the coding gene, but eliciting variations to the expression levels of the regulated genes. These considerations motivate the study of the rewiring of networks co-expressed genes as a consequence of the aforementioned alterations in order to complement the informative content of differential expression. We analyzed 339 mRNAomes of five distinct cancer types to find single genes that presented co-expression patterns strongly differentiated between normal and tumor phenotypes. Our analysis of differentially connected genes indicates the loss of connectivity as a common topological trait of cancer networks, and unveils novel candidate cancer genes. Moreover, our integrated approach that combines the differential expression together with the differential connectivity improves the classic enrichment pathway analysis providing novel insights on putative cancer gene biosystems not still fully investigated.

Ionizing radiation and glioblastoma exosomes: implications in tumor biology and cell migration

Exosomes are nanometer-sized lipid vesicles released ubiquitously by cells, which have been shown to have a normal physiological role, as well as influence the tumor microenvironment and aid metastasis. Recent studies highlight the ability of exosomes to convey tumor-suppressive and oncogenic mRNAs, microRNAs, and proteins to a receiving cell, subsequently activating downstream signaling pathways and influencing cellular phenotype. Here, we show that radiation increases the abundance of exosomes released by glioblastoma cells and normal astrocytes. Exosomes derived from irradiated cells enhanced the migration of recipient cells, and their molecular profiling revealed an abundance of molecules related to signaling pathways important for cell migration. In particular, connective tissue growth factor (CTGF) mRNA and insulin-like growth factor binding protein 2 (IGFBP2) protein levels were elevated, and coculture of nonirradiated cells with exosomes isolated from irradiated cells increased CTGF protein expression in the recipient cells. Additionally, these exosomes enhanced the activation of neurotrophic tyrosine kinase receptor type 1 (TrkA), focal adhesion kinase, Paxillin, and proto-oncogene tyrosine-protein kinase Src (Src) in recipient cells, molecules involved in cell migration. Collectively, our data suggest that radiation influences exosome abundance, specifically alters their molecular composition, and on uptake, promotes a migratory phenotype.

Co-expression of Rho guanine nucleotide exchange factor 5 and Src associates with poor prognosis of patients with resected non-small cell lung cancer

Specific and sensitive enough molecular biomarkers are lacking to accurately predict the survival of non-small cell lung cancer (NSCLC) patients. ARHGEF5 and Src have been shown to play an important role in tumorigenesis. However, the involvement of ARHGEF5 and Src in NSCLC remains unknown. Therefore, we evaluated the expression of ARHGEF5 and Src in resected NSCLC tissues and the correlation of co-expression of ARHGEF5 and Src and the prognosis of patients with resected NSCLC. Positive expression of ARHGEF5 was detected in 133 cases of 193 patients (68.91%). A total of 193 NSCLC patients (male: 145; female: 48; average age: 61.84 years; age range: 31-84) were enrolled in this study, of which 99 cases were squamous cell carcinomas (SCCs) (51.30%) and 94 cases were adenocarcinomas (ADCs) (48.70%). The expression of ARHGEF5 was mainly located in the cytoplasm of tumor cells, but not in the corresponding adjacent lung tissues. The levels of ARHGEF5 were significantly associated with age, differentiation and tumor stage. ARHGEF5 protein expression was associated with Src protein expression in NSCLC (χ(2) = 11.874, P<0.01) and in ADC (χ(2) = 12.194, P<0.01), but not in SCC. Co-immunoprecipitation revealed that there was a physical interaction between Src and ARHGEF5 in lung cancer cells. The patients with ARHGEF5(+)/Src(+) had a shorter survival time compared with the other patients (29.37 months versus 39.90 months, P = 0.029). In conclusion, ARHGEF5/Src can be considered as a prognostic biomarker and a therapeutic target for patients with resected NSCLC.

c-Src regulates cell cycle proteins expression through protein kinase B/glycogen synthase kinase 3 beta and extracellular signal-regulated kinases 1/2 pathways in MCF-7 cells

We have demonstrated that c-Src suppression inhibited the epithelial to mesenchymal transition in human breast cancer cells. Here, we investigated the role of c-Src on the cell cycle progression using siRNAs and small molecule inhibitor 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2). Western blot analysis demonstrated the down-regulation of cyclin D1 and cyclin E and up-regulation of p27 Kip1 after c-Src suppression by PP2. Incubation of cells in the presence of PP2 significantly blocked the phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2), protein kinase B (AKT), and glycogen synthase kinase 3 beta (GSK3β). Specific pharmacological inhibitors of MEK1/2/ERK1/2 and phosphatidylinositide 3-kinase/AKT pathways were used to demonstrate the relationship between the signal cascade and cell cycle proteins expression. The expression of cyclin D1 and cyclin E were decreased after inhibition of ERK1/2 or AKT activity, whereas the p27 Kip1 expression was increased. In addition, knockdown of c-Src by siRNAs reduced cell proliferation and phosphorylation of ERK1/2, AKT, and GSK3β. After c-Src depletion by siRNAs, we observed significant down-regulation of cyclin D1 and cyclin E, and up-regulation of p27 Kip1. These results suggest that c-Src suppression by PP2 or siRNAs may regulate the progression of cell cycle through AKT/GSK3β and ERK1/2 pathways.