ZEB1 sensitizes lung adenocarcinoma to metastasis suppression by PI3K antagonism

The transcription factor ZNF248 promotes colorectal cancer metastasis by binding to ZEB1

Colorectal cancer (CRC) is one of the most common malignant tumors globally, with metastasis emerging as the leading cause of mortality in CRC patients. Transcription factors play pivotal roles in the metastatic process. Using bioinformatics tools, we analyzed the TCGA-COAD and GES146587 datasets and identified ZNF248 participating in tumor progression. By analyzing 100 CRC patient tissues, it is found that ZNF248 is highly expressed in cancer tissue as well as in CRC cell lines identified by qRT-PCR. Our study discovered that ZNF248 enhances CRC cell migratory and invasive capabilities. A positive correlation was found between ZNF248 and epithelial-mesenchymal transition (EMT)-related markers (ZEB1, snail1), while E-cadherin exhibited a negative correlation with ZNF248. In addition, the analysis of the TCGA dataset demonstrated a strong correlation between the mRNA level of ZNF248 and ZEB1 expressions. Furthermore, it is found that the overexpression of ZEB1 could reverse CRC cell invasion and migration, along with the inhibition on EMT marker expressions induced by the RNA interference with ZNF248. Immunohistochemical analysis indicated a substantial association of ZNF248 expression with the lymph node metastasis, and with the liver metastasis (P =0.01, P =0.01), and a positive correlation between ZNF248 and ZEB1 expression (P =0.021) was also identified. Using Chip-PCR assay, it is found that ZNF248 bound to the ZEB1 promoter region. These findings showed that ZNF248 promotes CRC metastasis in vivo, revealed its role as an oncogene in CRC by targeting ZEB1 and activating the EMT pathway, which provided novel and promising biomarkers for CRC therapy through targeting ZEB1.

The mechanism of USP43 in the development of tumor: a literature review

Ubiquitination of the proteins is crucial for governing protein degradation and regulating fundamental cellular processes. Deubiquitinases (DUBs) have emerged as significant regulators of multiple pathways associated with cancer and other diseases, owing to their capacity to remove ubiquitin from target substrates and modulate signaling. Consequently, they represent potential therapeutic targets for cancer and other life-threatening conditions. USP43 belongs to the DUBs family involved in cancer development and progression. This review aims to provide a comprehensive overview of the existing scientific evidence implicating USP43 in cancer development. Additionally, it will investigate potential small-molecule inhibitors that target DUBs that may have the capability to function as anti-cancer medicines.

Mediation of association between benzo[a]pyrene exposure and lung cancer risk by plasma microRNAs: A Chinese case-control study

Epidemiologic studies have reported the positive relationship of benzo[a]pyrene (BaP) exposure with the risk of lung cancer. However, the mechanisms underlying the relationship is still unclear. Plasma microRNA (miRNA) is a typical epigenetic biomarker that was linked to environment exposure and lung cancer development. We aimed to reveal the mediation effect of plasma miRNAs on BaP-related lung cancer. We designed a lung cancer case-control study including 136 lung cancer patients and 136 controls, and measured the adducts of benzo[a]pyrene diol epoxide-albumin (BPDE-Alb) and sequenced miRNA profiles in plasma. The relationships between BPDE-Alb adducts, normalized miRNA levels and the risk of lung cancer were assessed by linear regression models. The mediation effects of miRNAs on BaP-related lung cancer were investigated. A total of 190 plasma miRNAs were significantly related to lung cancer status at Bonferroni adjusted P < 0.05, among which 57 miRNAs showed different levels with |fold change| > 2 between plasma samples before and after tumor resection surgery at Bonferroni adjusted P < 0.05. Especially, among the 57 lung cancer-associated miRNAs, BPDE-Alb adducts were significantly related to miR-17-3p, miR-20a-3p, miR-135a-5p, miR-374a-5p, miR-374b-5p, miR-423-5p and miR-664a-5p, which could in turn mediate a separate 42.2%, 33.0%, 57.5%, 36.4%, 48.8%, 32.5% and 38.2% of the relationship of BPDE-Alb adducts with the risk of lung cancer. Our results provide non-invasion biomarker candidates for lung cancer, and highlight miRNAs dysregulation as a potential intermediate mechanism by which BaP exposure lead to lung tumorigenesis.

NOTCH3 inhibits transcription factor ZEB1 expression and metastasis of breast cancer cells via transcriptionally upregulating miR-223

Background: NOTCH receptor 3 (NOTCH3) and zinc finger E-box binding protein 1 (ZEB1) play important roles in breast cancer respectively. NOTCH3 maintains the luminal phenotype and inhibits epithelial-mesenchymal transition (EMT) in breast cancer, while ZEB1 and NOTCH3 have the opposite effects. Methods: Public databases were used to predict the expression of NOTCH3 and ZEB1 in breast cancer cell lines. The regulatory effect of NOTCH3 on ZEB1 expression was verified by western blot and RT-PCR. MiRNAs regulating ZEB1 expression were identified by using multiple databases and confirmed by reporter gene experiments. Cellular function experiments were conducted to evaluate the role of NOTCH3/miR-223/ZEB1 in the proliferation and invasion of triple-negative breast cancer (TNBC). Results: NOTCH3 and ZEB1 have opposite expression pattern in MCF-7 cells that over-express LncATB or were incubated in TGF-β to induce EMT. Western blotting and RT-PCR showed that NOTCH3 could regulate expression of ZEB1. MiR-223 inhibited the proliferation and invasion of breast cancer cells via down-regulating the expression of ZEB1. NOTCH3 inhibited the proliferation and invasion of breast cancer cells via up-regulating the expression of miR-223. Clinically, high expression of NOTCH3, miR-223 or low expression of ZEB1 were related to good prognosis of breast cancer patients. Conclusion: The current study reports a novel NOTCH3/miR-223/ZEB1 axis, which can inhibit the proliferation and invasion of breast cancer cells, and may serve as a potential biomarker for the prognosis of breast cancer.

CircAGFG1 Promotes Ovarian Cancer Progression Through the miR-409-3 p/ZEB1 Axis

OBJECTIVES

Circular RNAs (circRNAs) serve a crucial regulatory role in ovarian cancer (OC). Circular RNA ArfGAP with FG repeats 1 (circAGFG1) has been shown to be involved in promoting the progression of several cancers, containing triple-negative breast cancer, esophageal cancer and colorectal cancer. However, the function of circAGFG1 in OC is unclear.

METHODS

Quantitative real-time reverse transcription PCR (RT-qPCR) was conducted to determine the expression levels of circAGFG1 and miR-409-3p. The proliferation and metastasis of cells were determined by colony formation assays, EdU assays, transwell assays and wound healing assays. In addition, a dual-luciferase reporter assay was performed to validate the mechanism between circAGFG1, miR-409-3p, and ZEB1.

RESULTS

Our data suggested that circAGFG1 was significantly overexpressed in OC tissues compared to normal ovarian epithelial tissues. Overexpression of circAGFG1 was correlated with intraperitoneal metastasis, tumor recurrence and advanced stage. Additionally, circAGFG1 overexpression revealed a poor prognosis in OC patients. Knockdown of circAGFG1 suppressed the proliferation, invasion and migration of OC cells. Mechanistically, circAGFG1 acted as a sponge of miR-409-3p to enhance the expression level of zinc finger E-box binding homeobox 1 (ZEB1), thereby conferring OC cell proliferation, invasion and migration. Importantly, re-expression of ZEB1 effectively reversed the effects of circAGFG1 knockdown on OC cells.

CONCLUSIONS

In summary, our study indicated that circAGFG1 may act as a prognostic biomarker and potential therapeutic target for patients with OC.

The p53/ZEB1-PLD3 feedback loop regulates cell proliferation in breast cancer

Breast cancer is the most prevalent cancer globally, endangering women's physical and mental health. Phospholipase D3 (PLD3) belongs to the phosphodiesterase family (PLD). PLD3 is related to insulin-mediated phosphorylation of the AKT pathway, suggesting that it may play a role in the occurrence and development of malignant tumors. This study may further explore the molecular mechanism of PLD3 inhibiting breast cancer cell proliferation. In this study, we demonstrated that PLD3 and miR-6796 are co-expressed in breast cancer. PLD3 can bind with CDK1 and inhibit its expression, leading to mitotic arrest and inhibiting breast cancer proliferation. Wild-type p53 regulates PLD3 and miR-6796 expression by competitively binding to the PLD3 promoter with ZEB1. DNMT3B, as the target gene of miR-6796, is recruited into the PLD3 promoter by combining with ZEB1 to regulate the DNA methylation of the PLD3 promoter and ultimately affect PLD3 and miR-6796 expression. In conclusion, we revealed the role and molecular mechanism of PLD3 and its embedded miR-6796 in breast cancer proliferation, providing clues and a theoretical foundation for future research and development of therapeutic targets and prognostic markers for breast cancer.

Targeting immunosuppressive Ly6C+ classical monocytes reverses anti-PD-1/CTLA-4 immunotherapy resistance

Introduction

Despite significant clinical advancement with the use of immune checkpoint blockade (ICB) in non-small cell lung cancer (NSCLC) there are still a major subset of patients that develop adaptive/acquired resistance. Understanding resistance mechanisms to ICB is critical to developing new therapeutic strategies and improving patient survival. The dynamic nature of the tumor microenvironment and the mutational load driving tumor immunogenicity limit the efficacy to ICB. Recent studies indicate that myeloid cells are drivers of ICB resistance. In this study we sought to understand which immune cells were contributing to resistance and if we could modify them in a way to improve response to ICB therapy.

Results

Our results show that combination anti-PD-1/CTLA-4 produces an initial antitumor effect with evidence of an activated immune response. Upon extended treatment with anti-PD-1/CTLA-4 acquired resistance developed with an increase of the immunosuppressive populations, including T-regulatory cells, neutrophils and monocytes. Addition of anti-Ly6C blocking antibody to anti-PD-1/CTLA-4 was capable of completely reversing treatment resistance and restoring CD8 T cell activity in multiple KP lung cancer models and in the autochthonous lung cancer KrasLSL-G12D/p53fl/fl model. We found that there were higher classical Ly6C+ monocytes in anti-PD-1/CTLA-4 combination resistant tumors. B7 blockade illustrated the importance of dendritic cells for treatment efficacy of anti-Ly6C/PD-1/CTLA-4. We further determined that classical Ly6C+ monocytes in anti-PD-1/CTLA-4 resistant tumors are trafficked into the tumor via IFN-γ and the CCL2-CCR2 axis. Mechanistically we found that classical monocytes from ICB resistant tumors were unable to differentiate into antigen presenting cells and instead differentiated into immunosuppressive M2 macrophages or myeloid-derived suppressor cells (MDSC). Classical Ly6C+ monocytes from ICB resistant tumors had a decrease in both Flt3 and PU.1 expression that prevented differentiation into dendritic cells/macrophages.

Conclusions

Therapeutically we found that addition of anti-Ly6C to the combination of anti-PD-1/CTLA-4 was capable of complete tumor eradication. Classical Ly6C+ monocytes differentiate into immunosuppressive cells, while blockade of classical monocytes drives dendritic cell differentiation/maturation to reinvigorate the anti-tumor T cell response. These findings support that immunotherapy resistance is associated with infiltrating monocytes and that controlling the differentiation process of monocytes can enhance the therapeutic potential of ICB.

ZEB1 Transcriptionally Activates PHGDH to Facilitate Carcinogenesis and Progression of HCC

BACKGROUND & AIMS

Phosphoglycerate dehydrogenase (PHGDH), the rate-limiting enzyme of the de novo serine synthesis pathway (SSP), has been implicated in the carcinogenesis and metastasis of hepatocellular carcinoma (HCC) because of its excessive expression and promotion of SSP. In previous experiments we found that SSP flux was diminished by knockdown of zinc finger E-box binding homeobox 1 (ZEB1), a stimulator of HCC metastasis, but the underlying mechanism remains largely unknown. Here, we aimed to determine how SSP flux is regulated by ZEB1 and the contribution of such regulation to carcinogenesis and progression of HCC.

METHODS

We used genetic mice with Zeb1 knockout in liver specifically to determine whether Zeb1 deficiency impacts HCC induced by the carcinogen diethylnitrosamine plus CCl4. We explored the regulatory mechanism of ZEB1 in SSP flux using uniformly-labeled [13C]-glucose tracing analyses, liquid chromatography-mass spectrometry, real-time quantitative polymerase chain reaction, luciferase report assay, and chromatin immunoprecipitation assay. We determined the contribution of the ZEB1-PHGDH regulatory axis to carcinogenesis and metastasis of HCC by cell counting assay, methyl thiazolyl tetrazolium (MTT) assay, scratch wound assay, Transwell assay, and soft agar assay in vitro, orthotopic xenograft, bioluminescence, and H&E assays in vivo. We investigated the clinical relevance of ZEB1 and PHGDH by analyzing publicly available data sets and 48 pairs of HCC clinical specimens.

RESULTS

We identified that ZEB1 activates PHGDH transcription by binding to a nonclassic binding site within its promoter region. Up-regulated PHGDH augments SSP flux to enable HCC cells to be more invasive, proliferative, and resistant to reactive oxygen species and sorafenib. Orthotopic xenograft and bioluminescence assays have shown that ZEB1 deficiency significantly impairs the tumorigenesis and metastasis of HCC, and such impairments can be rescued to a large extent by exogenous expression of PHGDH. These results were confirmed by the observation that conditional knockout of ZEB1 in mouse liver dramatically impedes carcinogenesis and progression of HCC induced by diethylnitrosamine/CCl4, as well as PHGDH expression. In addition, analysis of The Cancer Genome Atlas database and clinical HCC samples showed that the ZEB1-PHGDH regulatory axis predicts poor prognosis of HCC.

CONCLUSIONS

ZEB1 plays a crucial role in stimulating carcinogenesis and progression of HCC by activating PHGDH transcription and subsequent SSP flux, deepening our knowledge of ZEB1 as a transcriptional factor in fostering the development of HCC via reprogramming the metabolic pathway.

EMT-activated secretory and endocytic vesicular trafficking programs underlie a vulnerability to PI4K2A antagonism in lung cancer

Hypersecretory malignant cells underlie therapeutic resistance, metastasis, and poor clinical outcomes. However, the molecular basis for malignant hypersecretion remains obscure. Here, we showed that epithelial-mesenchymal transition (EMT) initiates exocytic and endocytic vesicular trafficking programs in lung cancer. The EMT-activating transcription factor zinc finger E-box-binding homeobox 1 (ZEB1) executed a PI4KIIIβ-to-PI4KIIα (PI4K2A) dependency switch that drove PI4P synthesis in the Golgi and endosomes. EMT enhanced the vulnerability of lung cancer cells to PI4K2A small-molecule antagonists. PI4K2A formed a MYOIIA-containing protein complex that facilitated secretory vesicle biogenesis in the Golgi, thereby establishing a hypersecretory state involving osteopontin (SPP1) and other prometastatic ligands. In the endosomal compartment, PI4K2A accelerated recycling of SPP1 receptors to complete an SPP1-dependent autocrine loop and interacted with HSP90 to prevent lysosomal degradation of AXL receptor tyrosine kinase, a driver of cell migration. These results show that EMT coordinates exocytic and endocytic vesicular trafficking to establish a therapeutically actionable hypersecretory state that drives lung cancer progression.

Carboxyl-terminal modulator protein facilitates tumor metastasis in triple-negative breast cancer

Currently, the survival rate for breast cancer is more than 90%, but once the cancer cells metastasize to distal organs, the survival rate is dramatically reduced, to less than 30%. Triple-negative breast cancer accounts for 15-20% of all breast cancers. Triple-negative breast cancer (TNBC) is associated with poor prognostic and diagnostic outcomes due to the limiting therapeutic strategies, relative to non-TNBC breast cancers. Therefore, the development of targeted therapy for TNBC metastasis remains an urgent issue. In this study, high Carboxyl-terminal modulator protein (CTMP) is significantly associated with recurrence and disease-free survival rate in TNBC patients. Overexpression of CTMP promotes migration and invasion abilities in BT549 cells. Down-regulating of CTMP expression inhibits migration and invasion abilities in MDA-MB-231 cells. In vivo inoculation of high-CTMP cells enhances distant metastasis in mice. The metastasis incidence rate is decreased in mice injected with CTMP-downregulating MDA-MB-231 cells. Gene expression microarray analysis indicates the Akt-dependent pathway is significantly enhanced in CTMP overexpressing cells compared to the parental cells. Blocking Akt activation via Akt inhibitor treatment or co-expression of the dominant-negative form of Akt proteins successfully abolishes the CTMP mediating invasion in TNBC cells. Our findings suggest that CTMP is a potential diagnostic marker for recurrence and poor disease-free survival in TNBC patients. CTMP promotes TNBC metastasis via the Akt-activation-dependent pathway.

Reprogramming of cancer-associated fibroblasts by apoptotic cancer cells inhibits lung metastasis via Notch1-WISP-1 signaling

The interplay between apoptotic cancer cells and the tumor microenvironment modulates cancer progression and metastasis. Cancer-associated fibroblasts (CAFs) play a crucial role in promoting these events through paracrine communication. Here, we demonstrate that conditioned medium (CM) from lung CAFs exposed to apoptotic cancer cells suppresses TGF-β1-induced migration and invasion of cancer cells and CAFs. Direct exposure of CAFs to apoptotic 344SQ cells (ApoSQ) inhibited CAF migration and invasion and the expression of CAF activation markers. Enhanced secretion of Wnt-induced signaling protein 1 (WISP-1) by CAFs exposed to ApoSQ was required for these antimigratory and anti-invasive effects. Pharmacological inhibition of Notch1 activation or siRNA-mediated Notch1 silencing prevented WISP-1 production by CAFs and reversed the antimigratory and anti-invasive effects. Enhanced expression of the Notch ligand delta-like protein 1 on the surface of ultraviolet-irradiated apoptotic lung cancer cells triggered Notch1-WISP-1 signaling. Phosphatidylserine receptor brain-specific angiogenesis inhibitor 1 (BAI1)-Rac1 signaling, which facilitated efferocytosis by CAFs, participated in crosstalk with Notch1 signaling for optimal production of WISP-1. In addition, a single injection of ApoSQ enhanced WISP-1 production, suppressed the expression of CAF activation markers in isolated Thy1⁺ CAFs, and inhibited lung metastasis in syngeneic immunocompetent mice via Notch1 signaling. Treatment with CM from CAFs exposed to ApoSQ suppressed tumor growth and lung metastasis, whereas treatment with WISP-1-immunodepleted CM from CAFs exposed to ApoSQ reversed the antitumorigenic and antimetastatic effects. Therefore, treatment with CM from CAFs exposed to apoptotic lung cancer cells could be therapeutically applied to suppress CAF activation, thereby preventing cancer progression and metastasis.

The role of the ZEB1–neuroinflammation axis in CNS disorders

Zinc finger E-box binding homeobox 1 (ZEB1) is a master modulator of the epithelial–mesenchymal transition (EMT), a process whereby epithelial cells undergo a series of molecular changes and express certain characteristics of mesenchymal cells. ZEB1, in association with other EMT transcription factors, promotes neuroinflammation through changes in the production of inflammatory mediators, the morphology and function of immune cells, and multiple signaling pathways that mediate the inflammatory response. The ZEB1–neuroinflammation axis plays a pivotal role in the pathogenesis of different CNS disorders, such as brain tumors, multiple sclerosis, cerebrovascular diseases, and neuropathic pain, by promoting tumor cell proliferation and invasiveness, formation of the hostile inflammatory micromilieu surrounding neuronal tissues, dysfunction of microglia and astrocytes, impairment of angiogenesis, and dysfunction of the blood–brain barrier. Future studies are needed to elucidate whether the ZEB1–neuroinflammation axis could serve as a diagnostic, prognostic, and/or therapeutic target for CNS disorders.

The microRNA-183/96/182 cluster inhibits lung cancer progression and metastasis by inducing an interleukin-2-mediated antitumor CD8+ cytotoxic T-cell response

Here, Kundu et al. investigated the role of the microRNA-183/96/182 cluster (m96cl) in lung cancer and used a novel conditional m96cl mouse to establish that loss of m96cl accelerated the growth of K-Ras mutant autochthonous lung adenocarcinomas. Overall, the authors identified a novel mechanistic role of the m96cl in the suppression of lung cancer growth and metastasis by inducing an IL2-mediated systemic CD8⁺ CTL immune response.

One of the mechanisms by which cancer cells acquire hyperinvasive and migratory properties with progressive loss of epithelial markers is the epithelial-to-mesenchymal transition (EMT). We have previously reported that in different cancer types, including nonsmall cell lung cancer (NSCLC), the microRNA-183/96/182 cluster (m96cl) is highly repressed in cells that have undergone EMT. In the present study, we used a novel conditional m96cl mouse to establish that loss of m96cl accelerated the growth of Kras mutant autochthonous lung adenocarcinomas. In contrast, ectopic expression of the m96cl in NSCLC cells results in a robust suppression of migration and invasion in vitro, and tumor growth and metastasis in vivo. Detailed immune profiling of the tumors revealed a significant enrichment of activated CD8⁺ cytotoxic T lymphocytes (CD8⁺ CTLs) in m96cl-expressing tumors, and m96cl-mediated suppression of tumor growth and metastasis was CD8⁺ CTL-dependent. Using coculture assays with naïve immune cells, we show that m96cl expression drives paracrine stimulation of CD8⁺ CTL proliferation and function. Using tumor microenvironment-associated gene expression profiling, we identified that m96cl elevates the interleukin-2 (IL2) signaling pathway and results in increased IL2-mediated paracrine stimulation of CD8⁺ CTLs. Furthermore, we identified that the m96cl modulates the expression of IL2 in cancer cells by regulating the expression of transcriptional repressors Foxf2 and Zeb1, and thereby alters the levels of secreted IL2 in the tumor microenvironment. Last, we show that in vivo depletion of IL2 abrogates m96cl-mediated activation of CD8⁺ CTLs and results in loss of metastatic suppression. Therefore, we have identified a novel mechanistic role of the m96cl in the suppression of lung cancer growth and metastasis by inducing an IL2-mediated systemic CD8⁺ CTL immune response.

Transcriptional control of a collagen deposition and adhesion process that promotes lung adenocarcinoma growth and metastasis

A fibrotic stroma accumulates in advanced cancers, and invasive cancer cells migrate along collagen fibers that facilitate dissemination from the primary tumor. However, the ways in which tumor cells govern these processes remain unclear. Here, we report that the epithelial-mesenchymal transition–activating transcription factor ZEB1 increased type I collagen (Col1) secretion and enhanced tumor cell adherence to Col1. Mechanistically, ZEB1 increased the levels of α₁β₁ integrin (encoded by Itga1 and Itgb1) by inhibiting PP2A activity, which reduced nuclear accumulation of HDAC4 and, thereby, derepressed Itga1 gene transcription. In parallel, ZEB1 relieved the miRNA-148a-mediated silencing of Itga1. High levels of Itga1 enhanced tumor cell adherence to Col1 and were essential for Col1-induced tumor growth and metastasis. Furthermore, ZEB1 enhanced Col1 secretion by increasing the expression of a kinesin protein that facilitated transport and secretion of Col1-containing vesicles. Our findings elucidate a transcriptional mechanism by which lung adenocarcinoma cells coordinate a collagen deposition and adhesion process that facilitates tumor progression.

ZEB1 represses biogenesis of circ-DOCK5 to facilitate metastasis in esophageal squamous cell carcinoma via a positive feedback loop with TGF-β

ZEB1 is an important transcription factor that plays a critical role in TGF-β-induced epithelial-mesenchymal transition (EMT) and tumor metastasis. However, the mechanisms by which ZEB1 regulates metastasis in esophageal squamous cell carcinoma (ESCC) remain largely unknown. Here, we identified a novel circular RNA, circ-DOCK5, the biogenesis of which is directly regulated by ZEB1 and ZEB1-repressed RNA-binding protein eIF4A3. Tissue microarray analysis identified circ-DOCK5 to be downregulated in ESCC tissues, and its downregulation correlated with poor prognosis. Moreover, circ-DOCK5 increased the stability of miR-627-3p by functioning as a "reservoir" for miR-627-3p to partially reverse the ZEB1-enhanced migration and invasion in ESCC. MiR-627-3p inhibited the expression of TGFB2 and the secretion of TGF-β, which further resulted in downregulation of ZEB1 and suppression of TGF-β-induced EMT. In vivo experiments showed that ZEB1 promoted metastasis in ESCC by regulating expression of circ-DOCK5. Therefore, the present study revealed that ZEB1-mediated downregulation of circ-DOCK5 facilitates metastasis in ESCC by forming a positive feedback loop with TGF-β by altering the miR-627-3p/TGFB2 signaling. Targeting this signaling pathway may help suppress progression in ESCC.

Elastic Net Models Based on DNA Copy Number Variations Predicts Clinical Features, Expression Signatures, and Mutations in Lung Adenocarcinoma

In the precision medicine of lung adenocarcinoma, the identification and prediction of tumor phenotypes for specific biomolecular events are still not studied in depth. Various earlier researches sheds light on the close correlation between genetic expression signatures and DNA copy number variations (CNVs), for which analysis of CNVs provides valuable information about molecular and phenotypic changes in tumorigenesis. In this study, we propose a comprehensive analysis combining genome-wide association analysis and an Elastic Net Regression predictive model, focus on predicting the levels of many gene expression signatures in lung adenocarcinoma, based upon DNA copy number features alone. Additionally, we predicted many other key phenotypes, including clinical features (pathological stage), gene mutations, and protein expressions. These Elastic Net prediction methods can also be applied to other gene sets, thereby facilitating their use as biomarkers in monitoring therapy.

Zeb1 induces immune checkpoints to form an immunosuppressive envelope around invading cancer cells

The PDL1-PD1 immune checkpoint inhibits T cell activation, and its blockade is effective in a subset of patients. Studies are investigating how checkpoints are hijacked by cancer cells and why most patients remain resistant to immunotherapy. Epithelial mesenchymal transition (EMT), which drives tumor cell invasion via the Zeb1 transcription factor, is linked to immunotherapy resistance. In addition, M2-polarized tumor-associated macrophages (TAMs), which inhibit T cell migration and activation, may also cause immunotherapy resistance. How EMT in invading cancer cells is linked to therapy resistance and events driving TAM M2 polarization are therefore important questions. We show that Zeb1 links these two resistance pathways because it is required for PDL1 expression on invading lung cancer cells, and it also induces CD47 on these invading cells, which drives M2 polarization of adjacent TAMs. Resulting reprogramming of the microenvironment around invading cells shields them from the hostile inflammatory environment surrounding tumors.

Organismal roles for the PI3Kα and β isoforms: their specificity, redundancy or cooperation is context-dependent

PI3Ks are important lipid kinases that produce phosphoinositides phosphorylated in position 3 of the inositol ring. There are three classes of PI3Ks: class I PI3Ks produce PIP3 at plasma membrane level. Although D. melanogaster and C. elegans have only one form of class I PI3K, vertebrates have four class I PI3Ks called isoforms despite being encoded by four different genes. Hence, duplication of these genes coincides with the acquisition of coordinated multi-organ development. Of the class I PI3Ks, PI3Kα and PI3Kβ, encoded by PIK3CA and PIK3CB, are ubiquitously expressed. They present similar putative protein domains and share PI(4,5)P2 lipid substrate specificity. Fifteen years after publication of their first isoform-selective pharmacological inhibitors and genetically engineered mouse models (GEMMs) that mimic their complete and specific pharmacological inhibition, we review the knowledge gathered in relation to the redundant and selective roles of PI3Kα and PI3Kβ. Recent data suggest that, further to their redundancy, they cooperate for the integration of organ-specific and context-specific signal cues, to orchestrate organ development, physiology, and disease. This knowledge reinforces the importance of isoform-selective inhibitors in clinical settings.

PI4KIIIβ is a therapeutic target in chromosome 1q-amplified lung adenocarcinoma

Heightened secretion of protumorigenic effector proteins is a feature of malignant cells. Yet, the molecular underpinnings and therapeutic implications of this feature remain unclear. Here, we identify a chromosome 1q region that is frequently amplified in diverse cancer types and encodes multiple regulators of secretory vesicle biogenesis and trafficking, including the Golgi-dedicated enzyme phosphatidylinositol (PI)-4-kinase IIIβ (PI4KIIIβ). Molecular, biochemical, and cell biological studies show that PI4KIIIβ-derived PI-4-phosphate (PI4P) synthesis enhances secretion and accelerates lung adenocarcinoma progression by activating Golgi phosphoprotein 3 (GOLPH3)-dependent vesicular release from the Golgi. PI4KIIIβ-dependent secreted factors maintain 1q-amplified cancer cell survival and influence prometastatic processes in the tumor microenvironment. Disruption of this functional circuitry in 1q-amplified cancer cells with selective PI4KIIIβ antagonists induces apoptosis and suppresses tumor growth and metastasis. These results support a model in which chromosome 1q amplifications create a dependency on PI4KIIIβ-dependent secretion for cancer cell survival and tumor progression.

USP43 directly regulates ZEB1 protein, mediating proliferation and metastasis of colorectal cancer

Colorectal cancer is one of the most common malignant tumors of the digestive tract. In this study, we had examined the biological role of USP43 in colorectal cancer. USP43 protein and mRNA abundance in clinical tissues and five cell lines were analyzed with quantitative real-time PCR test (qRT-PCR) and western blot. USP43 overexpression treated DLD1 cells and USP43 knockdown treated SW480 cells were used to study cell proliferation, migration, colony formation, invasion, and the expression of epithelial-mesenchymal transformation (EMT) biomarkers. Moreover, ubiquitination related ZEB1 degradation was studied with qRT-PCR and western blot. The relationships between USP43 and ZEB1 were investigated with western blot, co-immunoprecipitation, migration, and invasion. USP43 was highly expressed in colorectal cancer tissues. USP43 overexpression and knockdown treatments could affect cell proliferation, colony formation, migration, invasion, and the expression of EMT associated biomarkers. Moreover, USP43 can regulate ZEB1 degradation through ubiquitination pathway. USP43 could promote the proliferation, migration, and invasion of colorectal cancer. Meanwhile, USP43 can deubiquitinate and stabilize the ZEB1 protein, which plays an important role in the function of colorectal cancer.

Emerging role of tumor cell plasticity in modifying therapeutic response

Resistance to cancer therapy is a major barrier to cancer management. Conventional views have proposed that acquisition of resistance may result from genetic mutations. However, accumulating evidence implicates a key role of non-mutational resistance mechanisms underlying drug tolerance, the latter of which is the focus that will be discussed here. Such non-mutational processes are largely driven by tumor cell plasticity, which renders tumor cells insusceptible to the drug-targeted pathway, thereby facilitating the tumor cell survival and growth. The concept of tumor cell plasticity highlights the significance of re-activation of developmental programs that are closely correlated with epithelial-mesenchymal transition, acquisition properties of cancer stem cells, and trans-differentiation potential during drug exposure. From observations in various cancers, this concept provides an opportunity for investigating the nature of anticancer drug resistance. Over the years, our understanding of the emerging role of phenotype switching in modifying therapeutic response has considerably increased. This expanded knowledge of tumor cell plasticity contributes to developing novel therapeutic strategies or combination therapy regimens using available anticancer drugs, which are likely to improve patient outcomes in clinical practice.

Cardamonin inhibits the proliferation and metastasis of non-small-cell lung cancer cells by suppressing the PI3K/Akt/mTOR pathway

Cardamonin, a natural chalcone compound, has been reported to exert anticancer effects in several cancers. However, the specific pharmacological actions of cardamonin on human non-small-cell lung cancer (NSCLC) and the potential mechanisms still remain obscure. Here, we investigated the antineoplastic role of cardamonin in NSCLC both in vitro and in vivo. The proliferation of five NSCLC cell lines was inhibited in a dose-dependent and time-dependent manner with cardamonin treatment. In A549 and H460 cells, cardamonin induced apoptosis by activating caspase-3, upregulating Bax, and downregulating Bcl-2. In addition, cardamonin arrested cells in the G2/M phase and inhibited the expression levels of cyclin D1/CDK4. Moreover, cell migration and invasion were suppressed by reversing epithelial-mesenchymal transition with cardamonin treatment. Further study showed that cardamonin reduced the phosphorylation levels of the downstream effectors of phosphoinositide 3-kinase (PI3K), including protein kinase-B (Akt/PKB) and mammalian target of rapamycin (mTOR). Moreover, in the H460 xenograft model, cardamonin significantly retarded tumor growth. Also, in tumor tissues, we found that cardamonin treatment decreased the expression rates of Ki-67, p-Akt, and p-mTOR. These data suggest that cardamonin suppressed NSCLC cell proliferation and inhibited metastasis partly by restraining the PI3K/Akt/mTOR pathway and it might be an effective therapeutic compound for NSCLC in the future.

Development of syngeneic murine cell lines for use in immunocompetent orthotopic lung cancer models

BACKGROUND

Immunocompetent animal models are required to study tumor-host interactions, immunotherapy, and immunotherapeutic combinations, however the currently available immunocompetent lung cancer models have substantial limitations. While orthotopic models potentially help fill this gap, the utility of these models has been limited by the very small number of murine lung cancer cell lines capable of forming orthotopic tumors in immunocompetent C57BL/6 hosts.

METHODS

Primary lung tumors with specific genetic alterations were created in C57BL/6 background mice. These tumors were then passaged through other animals to increase tumorigenicity and select for the ability to grow in a non-self animal. Once tumors demonstrated growth in a non-self host, cell lines were established. Successful cell lines were evaluated for the ability to produce orthotopic lung tumors in immunocompetent hosts.

RESULTS

We produced six murine lung cancer lines capable of orthotopic lung tumor formation in immunocompetent C57BL/6 animals. These lines demonstrate the expected genetic alterations based on their primary tumor genetics.

CONCLUSIONS

These novel cell lines will be useful for evaluating tumor-host interactions, the impact of specific oncogenic alterations on the tumor microenvironment, and immunotherapeutic approaches. This method of generating murine lines capable of orthotopic growth can likely be applied to other tumors and will broaden the applicability of pre-clinical testing of immunotherapeutic treatment regimens.

Epigenetic upregulation of HOXC10 in non-small lung cancer cells

The homeobox genes (HOX) have emerged as a new family of master regulators of development and cancer. In the current study, we examined the expression and function of HOXC10 in human non-small cell lung cancer (NSCLC). We observed increased expression of HOXC10 in the more aggressive human NSCLC cell line NCI-H23 over the well differentiated A549 cells. To elucidate the expression and function of HOXC10 in NSCLC cells, we employed RT-PCR, immunoblotting, methylation-specific PCR, apoptosis assays, and xenograft model. Overexpression of HOXC10 in A549 cells conveyed increased proliferation, reduced apoptosis, and accelerated tumor growth when transplanted into nude mice. In contrast, siRNA-mediated knockdown of HOXC10 in NCI-H23 cells reduced proliferation and increased apoptosis. Our results further indicated that hypomethylation of the CpG island in the HOXC10 promoter was critical to elevated expression of HOXC10 in NSCLC cells. Lastly, we identified a G-quadruplex in the HOXC10 promoter and its G-quadruplex formation was required for elevated expression of HOXC10 in NSCLC cells. Moreover our results suggest that disruption of G-quadruplex formation can silence HOXC10 expression in NSCLC cells. In summary, we report HOXC10 as a novel tumor promoting oncogene in NSCLC cells.

Zeb1 promotes corneal neovascularization by regulation of vascular endothelial cell proliferation

Angiogenesis is required for tissue repair; but abnormal angiogenesis or neovascularization (NV) causes diseases in the eye. The avascular status in the cornea is a prerequisite for corneal clarity and thought to be maintained by the equilibrium between proangiogenic and antiangiogenic factors that controls proliferation and migration of vascular endothelial cells (ECs) sprouting from the pericorneal plexus. VEGF is the most important intrinsic factor for angiogenesis; anti-VEGF therapies are available for treating ocular NV. However, the effectiveness of the therapies is limited because of VEGF-independent mechanism(s). We show that Zeb1 is an important factor promoting vascular EC proliferation and corneal NV; and a couple of small molecule inhibitors can evict Ctbp from the Zeb1-Ctbp complex, thereby reducing EC Zeb1 expression, proliferation, and corneal NV. We conclude that Zeb1-regulation of angiogenesis is independent of Vegf and that the ZEB1-CtBP inhibitors can be of potential therapeutic significance in treating corneal NV.

Tumor progression and chromatin landscape of lung cancer are regulated by the lineage factor GATA6

Lineage selective transcription factors (TFs) are important regulators of tumorigenesis, but their biological functions are often context dependent with undefined epigenetic mechanisms of action. In this study, we uncover a conditional role for the endodermal and pulmonary specifying TF GATA6 in lung adenocarcinoma (LUAD) progression. Impairing Gata6 in genetically engineered mouse models reduces the proliferation and increases the differentiation of Kras mutant LUAD tumors. These effects are influenced by the epithelial cell type that is targeted for transformation and genetic context of Kras-mediated tumor initiation. In LUAD cells derived from surfactant protein C expressing progenitors, we identify multiple genomic loci that are bound by GATA6. Moreover, suppression of Gata6 in these cells significantly alters chromatin accessibility, particularly at distal enhancer elements. Analogous to its paradoxical activity in lung development, GATA6 expression fluctuates during different stages of LUAD progression and can epigenetically control diverse transcriptional programs associated with bone morphogenetic protein signaling, alveolar specification, and tumor suppression. These findings reveal how GATA6 can modulate the chromatin landscape of lung cancer cells to control their proliferation and divergent lineage dependencies during tumor progression.

ZEB1 suppression sensitizes KRAS mutant cancers to MEK inhibition by an IL17RD-dependent mechanism

Mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitors have failed to show clinical benefit in Kirsten rat sarcoma (KRAS) mutant lung cancer due to various resistance mechanisms. To identify differential therapeutic sensitivities between epithelial and mesenchymal lung tumors, we performed in vivo small hairpin RNA screens, proteomic profiling, and analysis of patient tumor datasets, which revealed an inverse correlation between mitogen-activated protein kinase (MAPK) signaling dependency and a zinc finger E-box binding homeobox 1 (ZEB1)-regulated epithelial-to-mesenchymal transition. Mechanistic studies determined that MAPK signaling dependency in epithelial lung cancer cells is due to the scaffold protein interleukin-17 receptor D (IL17RD), which is directly repressed by ZEB1. Lung tumors in multiple Kras mutant murine models with increased ZEB1 displayed low IL17RD expression, accompanied by MAPK-independent tumor growth and therapeutic resistance to MEK inhibition. Suppression of ZEB1 function with miR-200 expression or the histone deacetylase inhibitor mocetinostat sensitized resistant cancer cells to MEK inhibition and markedly reduced in vivo tumor growth, showing a promising combinatorial treatment strategy for KRAS mutant cancers. In human lung tumor samples, high ZEB1 and low IL17RD expression correlated with low MAPK signaling, presenting potential markers that predict patient response to MEK inhibitors.

Tartrate-Resistant Acid Phosphatase 5/ACP5 Interacts with p53 to Control the Expression of SMAD3 in Lung Adenocarcinoma

Tartrate-resistant acid phosphatase 5 (TRAP/ACP5) has been shown to involve the development and prognosis of multiple tumors in previous studies; however, the mechanism in lung cancer is still unclear, and thus this study investigated the role of ACP5 in the progression of lung adenocarcinoma. After a series of in vitro and in vivo experiments, we observed that ACP5 expression was increased in lung adenocarcinomas (40/69, 57.97%); importantly, an increased ACP5 level was associated with patient age (p = 0.044) and lymph node metastasis (p = 0.0385). ACP5 overexpression significantly enhanced A549 and NCI-H1975 cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) and reduced cell apoptosis. Knocking down the expression of ACP5 could rescue the above cell phenotypes. Furthermore, enhancing ACP5 expression promoted lung adenocarcinoma cell hyperplasia and intrapulmonary metastasis in a mouse model. Additionally, mechanistic studies revealed that ACP5 might regulate p53 phosphorylation at Ser392, thereby enhancing the ubiquitination of p53, which then underwent degradation. Reducing the levels of p53 intensified the transcription of SMAD3, which promotes EMT in lung adenocarcinoma cells. In summary, the present study provides a theoretical basis and important scientific evidence on the key role of ACP5 in lung adenocarcinoma progression by inducing EMT via the regulation of p53/SMAD3 signaling.

Oncogenic functions of the EMT-related transcription factor ZEB1 in breast cancer

Zinc finger E-box binding homeobox 1 (ZEB1, also termed TCF8 and δEF1) is a crucial member of the zinc finger-homeodomain transcription factor family, originally identified as a binding protein of the lens-specific δ1-crystalline enhancer and is a pivotal transcription factor in the epithelial-mesenchymal transition (EMT) process. ZEB1 also plays a vital role in embryonic development and cancer progression, including breast cancer progression. Increasing evidence suggests that ZEB1 stimulates tumor cells with mesenchymal traits and promotes multidrug resistance, proliferation, and metastasis, indicating the importance of ZEB1-induced EMT in cancer development. ZEB1 expression is regulated by multiple signaling pathways and components, including TGF-β, β-catenin, miRNA and other factors. Here, we summarize the recent discoveries of the functions and mechanisms of ZEB1 to understand the role of ZEB1 in EMT regulation in breast cancer.

Expression of OPN3 in lung adenocarcinoma promotes epithelial-mesenchymal transition and tumor metastasis

Background

Lung adenocarcinoma is the most common pathological lung cancer and an important cause of cancer‐related death. Metastasis is a major underlying reason for poor prognosis of lung adenocarcinoma. Opsin3 (OPN3), a member of the guanine nucleotide‐binding protein‐coupled receptor superfamily, has been identified to affect the apoptosis of hepatoma cells by modulating the phosphorylation of Akt and Bcl2/Bax. However, the expression and role of OPN3 in lung adenocarcinoma remains unclear.

Methods

Opsin3 expression in lung adenocarcinoma tissues was detected by western blot, qPCR, and immunohistochemistry. Changes in cell migration and invasion ability resulting from the change of OPN3 expression level were detected by wound healing and transwell migration assays. Changes in the markers of epithelial‐mesenchymal transformation were detected by western blot and qPCR.

Results

Opsin3 expression in lung adenocarcinoma tissues was higher than that in normal lung tissues. Patients with high expression of OPN3 had lower survival rates. Owing to overexpression of OPN3, the HCC827 cells showed enhanced invasion and migration ability in vitro. Upon decreasing the expression of OPN3, the invasion and migration ability of the A549 cells decreased.

Conclusion

Our study demonstrated for the first time that OPN3 gene enhanced the metastasis in lung adenocarcinoma, and its overexpression promoted epithelial‐mesenchymal transition.

Key points

A significant finding of the study was that OPN3 acted an oncogene in promoting lung adenocarcinoma metastasis. Our study complemented the research on the expression and function of OPN3 in lung adenocarcinoma.

M-phase phosphoprotein 8 promotes gastric cancer growth and metastasis via p53/Bcl-2 and EMT-related signaling pathways

BACKGROUND

The main issue of this study is to demonstrate whether M-phase phosphoprotein 8 (MPP8) affect gastric tumor growth and metastasis.

METHODS

Retrospective study was proceeded in 280 patients' surgical specimens with different disease stages. Loss-of-function assays, including 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, flow cytometry, and transwell assays were performed to evaluate the biological function of MPP8 in gastric cancer cells. Apoptosis and metastasis relative biomarkers were measured by quantitative real-time polymerase chain reaction and Western blot analysis.

RESULTS

Compared with normal adjacent tissues, obviously elevated MPP8 expression was found in gastric cancer tissues. Elevated MPP8 expression was associated with male sex (vs female sex), intermediate differentiation (vs poorly differentiated cancer), and later stage (vs earlier stage). Furthermore, MPP8 overexpression in tumor tissues was marginally associated with a poor prognosis, with a significant relationship between MPP8 overexpression and prognosis among patients with poorly differentiated gastric cancer. Inhibition of MPP8 in these cells significantly suppressed proliferation and colony formation, promoted apoptosis, and repressed invasion. Furthermore, silencing of MPP8 remarkably increased apoptosis-related proteins (p53, Bax, and PARP) expression, but downregulated Bcl-2 expression. Silencing of MPP8 also decreased the expression of metastasis pathway-related proteins (N-cadherin and vimentin), and as well as the levels of anti-oncogene ZEB1, MET, and KRAS mRNA.

CONCLUSION

Our findings demonstrated that MPP8 might be an oncogene by positively regulating gastric cancer cell function through the p53/Bcl-2 and epithelial to mesenchymal transition-related signaling pathways.

Behind the Wheel of Epithelial Plasticity in KRAS-Driven Cancers

Cellular plasticity, a feature associated with epithelial-to-mesenchymal transition (EMT), contributes to tumor cell survival, migration, invasion, and therapy resistance. Phenotypic plasticity of the epithelium is a critical feature in multiple phases of human cancer in an oncogene- and tissue-specific context. Many factors can drive epithelial plasticity, including activating mutations in KRAS, which are found in an estimated 30% of all cancers. In this review, we will introduce cellular plasticity and its effect on cancer progression and therapy resistance and then summarize the drivers of EMT with an emphasis on KRAS effector signaling. Lastly, we will discuss the contribution of cellular plasticity to metastasis and its potential clinical implications. Understanding oncogenic KRAS cellular reprogramming has the potential to reveal novel strategies to control metastasis in KRAS-driven cancers.

A Systematic Review and Bioinformatics Study on Genes and micro-RNAs Involving the Transformation of Endometriosis into Ovarian Cancer

BACKGROUND

Along with the description of tumorigenesis processes in endometriosisrelated ovarian cancer, identifying dysregulated miRNAs, the target genes of these miRNAs, and the processes abnormally affected by dysregulated miRNAs is essential, which was our goal.

METHODS

Two reviewers individually evaluated the articles which collected relevant information including genes and miRNAs involved in the transformation of endometriosis into ovarian cancer. To assess the mature sequence of miRNAs and also their chromosomal positions, miRPathDB software was employed. To determine the main target gene predicted for each considered miRNAs, the TargetScanS Web server was applied. The interaction of each gene with other genes associated with endometrial- related ovarian cancer was determined by GeneMANIA software. Finally, to design integrated model of miRNAs-targeted genes interaction network, the Cytoscape software was used.

RESULTS

The final number of studies available for analysis was 6 manuscripts including 22 miRNAs described as involved in the transformation of endometriosis into different subtypes of ovarian cancers (14 miRNAs up-regulated and 8 miRNAs down-regulated). Three miRNAs of miR-141 (upregulated), miR-205 (down-regulated), and miR-125b (down-regulated) were revealed as the originator for genetic interactions leading to carcinogenesis. We could show some common loops and pathways including uncontrolled cell proliferation and abnormal apoptosis (mediated by PTEN gene induced by miR-21 and miR-214), and disaggregation and epithelialization (mediated by ZEB1 and ZEB2 genes induced by miR-200).

CONCLUSION

According to our analysis, up-regulation of miR-141 and down-regulation of miR-205 and miR-125b have a central role in transforming endometriosis to ovarian cancer.

Nutritional status affects the microRNA profile of the hypothalamus of female sheep

Recent studies on the seasonal regulation of the oestrous cycle in sheep have focussed mainly on the responses to photoperiod. However, the brain systems that control reproductive activity also respond to nutritional inputs, although the molecular mechanisms involved are not completely understood. One possibility is that small, non-coding RNAs, such as micro-RNAs (miRNAs), have significant influence. In the present study, the amounts and characteristics of miRNAs in hypothalamus from oestrous and anestrous ewes, fed low- or high-nutrient diets, were compared using Illumina HiSeq sequencing technology. In total, 398 miRNAs, including 261 novel miRNAs, were identified in ewes with an enhanced nutritional status (HEN), whereas 384 miRNAs, including 247 novel miRNAs, were identified in the ewes with a lesser nutritional status (HAN). There were eight conserved and 140 novel miRNAs expressed differentially between the two libraries. Based on quantitative real-time polymerase chain reaction, six miRNAs were assessed to verify the accuracy of the library database. Moreover, the correlation between the miRNA target and several upstream and downstream genes in the oestrus-related pathways were also verified in hypothalamus nerve cells. According to the results, nutritional status plays an important role in oestrous regulation in sheep, and the hypothalamic processes and pathways induced by nutritional signals (folic acid and tyrosine) are different from those induced by photoperiodic regulation of oestrus. We have expanded the repertoire of sheep miRNAs that could contribute to the molecular mechanisms that regulate the initiation of oestrous cycles in anestrous ewes in response to the influence of nutritional status.

mTORC1 inhibitor RAD001 (everolimus) enhances non-small cell lung cancer cell radiosensitivity in vitro via suppressing epithelial-mesenchymal transition

Resistance to radiotherapy causes non-small cell lung cancer (NSCLC) treatment failure associated with local recurrence and metastasis. Thus, understanding the radiosensitization of NSCLC cells is crucial for developing new treatments and improving prognostics. mTORC1 has been shown to regulate tumor cell radiosensitivity, but the underlying mechanisms are unclear. Moreover, mTORC1 also regulates epithelial-mesenchymal transition (EMT) that is important to metastasis and recurrence. In this study we explored whether mTORC1 regulated NSCLC cell radiosensitivity by altering EMT. We performed immunohistichemical analysis using tumor, adjacent and normal tissues from 50 NSCLC patients, which confirmed significantly elevated mTOR protein expression in NSCLC tissue. Then we used NCI-H460 and NCI-H661 cell lines to examine the effects of the mTORC1 inhibitor RAD001 (everolimus) on in vitro radiosensitivity, protein expression and dose-survival curves. RAD001 (10 nmol/L) significantly inhibited the mTORC1 pathway in both the cell lines. Pretreatment with RAD001 (0.1 nmol/L) enhanced the radiosensitivity in NCI-H661 cells with wild-type PIK3CA and KRAS but not in NCI-H460 cells with mutant PIK3CA and KRAS; the sensitivity enhancement ratios in the two NSCLC cell lines were 1.40 and 1.03, respectively. Furthermore, pretreatment with RAD001 (0.1 nmol/L) significantly decreased the migration and invasion with altered expression of several EMT-associated proteins (significantly increased E-cadherin and decreased vimentin expression) in irradiated NCI-H661 cells. Publicly available expression data confirmed that irradiation affected mTOR and EMT-associated genes at the transcript level in NSCLC cells. These results suggest that mTORC1 inhibition enhances the in vitro radiosensitivity of NSCLC cells with wild-type PIK3CA and KRAS by affecting EMT. Our preclinical data may provide a potential new strategy for NSCLC treatment.

Restoration of mutant K-Ras repressed miR-199b inhibits K-Ras mutant non-small cell lung cancer progression

BACKGROUND

miRNAs play crucial role in the progression of K-Ras-mutated nonsmall cell lung cancer (NSCLC). However, most studies have focused on miRNAs that target K-Ras. Here, we investigated miRNAs regulated by mutant K-Ras and their functions.

METHODS

miRNAs regulated by mutant K-Ras were screened using miRNA arrays. miR-199b expression levels were measured by qRT-PCR. The protein expression levels were measured using Western blot and immunohistochemistry. The effects of miR-199b on NSCLC were examined both in vitro and in vivo by overexpressing or inhibiting miR-199b. DNA methylation was measured by bisulfite sequencing.

RESULTS

An inverse correlation was observed between K-Ras mutation status and miR-199b levels in NSCLC specimens and cell lines. The inhibition of miR-199b stimulated NSCLC growth and metastasis, while restoration of miR-199b suppressed K-Ras mutation-driven lung tumorigenesis as well as K-Ras-mutated NSCLC growth and metastasis. miR-199b inactivated ERK and Akt pathways by targeting K-Ras, KSR2, PIK3R1, Akt1, and Rheb1. Furthermore, we determined that mutant K-Ras inhibits miR-199b expression by increasing miR-199b promoter methylation.

CONCLUSION

Our findings suggest that mutant K-Ras plays an oncogenic role through downregulating miR-199b in NSCLC and that overexpression of miR-199b is a novel strategy for the treatment of K-Ras-mutated NSCLC.

Predictive and prognostic value of ZEB1 protein expression in breast cancer patients with neoadjuvant chemotherapy

Background

Zinc finger E-box binding homeobox 1 (ZEB1) is a molecule involved in the progression of epithelial-to-mesenchymal transition (EMT) in various kinds of cancers. Here, we aimed to determine whether the expression of the ZEB1 protein is related to the response of patients to neoadjuvant therapy as well as their survival outcome.

Methods

Immunohistochemistry (IHC) was performed on paraffin-embedded tumor samples from core needle biopsy before neoadjuvant therapy (NAT). Univariate and multivariate logistic regression analyses were used to analyze the associations between the protein expression of ZEB1 and the pathological complete response (pCR) outcome. Kaplan-Meier plots and log-rank tests were used to compare disease-free survival (DFS) between groups. A Cox proportional hazards model was used to calculate the adjusted hazard ratio (HR) with a 95% confidential interval (95% CI).

Results

A total of 75 patients were included in the IHC test. High ZEB1 protein expression was associated with a low pCR rate in both univariate (OR = 0.260, 95% CI 0.082-0.829, p = 0.023) and multivariate (OR = 0.074, 95% CI 0.011-0.475, p = 0.006) logistic regression analyses. High ZEB1 protein expression was also associated with a short DFS according to both the log-rank test (p = 0.023) and Cox proportional hazard model (HR = 9.025, 95% CI 1.024-79.519, p = 0.048). In hormone receptor positive (HorR-positive) patients, high ZEB1 protein expression was also associated with a lower pCR (OR = 0.054, 95% CI 0.007-0.422, p = 0.005) and a poorer DFS (HR = 10.516, 95% CI 1.171-94.435, p = 0.036) compared with low ZEB1 protein expression. In HER2-overexpressing patients, ZEB1 protein expression was also associated with poor survival (p = 0.042).

Conclusions

Our results showed that high ZEB1 protein expression was a negative predictive marker of pCR and DFS in neoadjuvant therapy in breast cancer patients and in HorR-positive and HER2-overexpressing subgroups.Trial registration NCT, NCT02199418. Registered 24 July 2014-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02199418?term=NCT02199418&rank=1. NCT, NCT 02221999. Registered 21 August 2014-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02221999?term=NCT02221999&rank=1.

Programming of macrophages by UV-irradiated apoptotic cancer cells inhibits cancer progression and lung metastasis

Apoptotic cell clearance by phagocytes is essential in tissue homeostasis. We demonstrated that conditioned medium (CM) from macrophages exposed to apoptotic cancer cells inhibits the TGFβ1-induced epithelial–mesenchymal transition (EMT), migration, and invasion of cancer cells. Apoptotic 344SQ (ApoSQ) cell-induced PPARγ activity in macrophages increased the levels of PTEN, which was secreted in exosomes. Exosomal PTEN was taken up by recipient lung cancer cells. ApoSQ-exposed CM from PTEN knockdown cells failed to enhance PTEN in 344SQ cells, restore cellular polarity, or exert anti-EMT and anti-invasive effects. The CM that was deficient in PPARγ ligands, including 15-HETE, lipoxin A4, and 15d-PGJ₂, could not reverse the suppression of PPARγ activity or the PTEN increase in 344SQ cells and consequently failed to prevent the EMT process. Moreover, a single injection of ApoSQ cells inhibited lung metastasis in syngeneic immunocompetent mice with enhanced PPARγ/PTEN signaling both in tumor-associated macrophages and in tumor cells. PPARγ antagonist GW9662 reversed the signaling by PPARγ/PTEN; the reduction in EMT-activating transcription factors, such as Snai1 and Zeb1; and the antimetastatic effect of the ApoSQ injection. Thus, the injection of apoptotic lung cancer cells may offer a new strategy for the prevention of lung metastasis.

Downregulation of GATA6 in mTOR-inhibited human aortic endothelial cells: effects on TNF-α-induced VCAM-1 expression and monocytic cell adhesion

Increased expression of vascular cell adhesion molecule 1 (VCAM-1) on the aortic endothelium is an early marker of atherogenesis, promoted in part by elevated levels of inflammatory cytokines such as TNF-α. Mammalian target of rapamycin (mTOR) is a ubiquitous signaling molecule that has been considered to contribute to diverse cellular processes through mTOR complex 1 (mTORC1) or complex 2 (mTORC2). This study aimed to elucidate the role of mTOR signaling in TNF-α-induced VCAM-1 expression by the arterial endothelium. Primary human aortic endothelial cells (HAECs) were treated with low-dose (0.1 ng/ml) TNF-α, and VCAM-1 expression was measured by real-time quantitative PCR, Western blot analysis, and flow cytometry. Inhibition of mTOR through siRNA-mediated depletion or treatment with chemical inhibitors rapamycin or torin 1 suppressed VCAM1 transcription, which translated to inhibition of VCAM-1 surface expression by HAECs and concomitant decreased adhesion of monocytes. A promoter luciferase assay and chromatin immunoprecipitation indicated that mTOR regulated VCAM1 transcription through a mechanism involving transcription factor GATA6. Activation of PKC-α and an increase in miR-200a-3p expression, caused by mTOR inhibition but not disruption of mTORC1 or mTORC2 singly or together, decreased TNF-α-induced GATA6 expression and its enrichment at the VCAM1 promoter. In conclusion, mTOR inhibition activates PKC-α independently of disruption of mTORC1 and/or mTORC2, which challenges the conventional wisdom regarding mTOR signaling. Moreover, mTOR signals through transcriptional and posttranscriptional mechanisms to elicit maximal cytokine-induced endothelial inflammation that precedes atherosclerosis. NEW & NOTEWORTHY Both mammalian target of rapamycin (mTOR) complex 1 (mTORC1) and mTORC2 contribute to PKC-α activation in the human aortic endothelium. Inhibition of mTOR is not equivalent to disruption of mTORC1 and/or mTORC2 in affecting human aortic endothelial cell signaling. Specifically, inhibition of mTOR causes PKC-α activation and miR-200a-3p upregulation, which independently suppresses TNF-α-induced transcription factor GATA6 expression and subsequently inhibits VCAM-1 expression and monocytic cell adhesion onto the aortic endothelium.

High CCL7 expression is associated with migration, invasion and bone metastasis of non-small cell lung cancer cells

Distant metastasis is the main cause of death for non-small cell lung cancer (NSCLC) patients, with the bone as a more frequent metastatic site. The expression of various chemokines and their receptors may contribute to the predilection of organ specific metastasis. In this study, we demonstrated that CC chemokine ligand 7 (CCL7) and its receptors CCR1, CCR2 and CCR3 were up-regulated markedly in lung cancer bone metastasis. In addition, CCL7 promoted migration and invasion of lung cancer cells in a dose-dependent pattern but played an insignificant role in cell proliferation mainly through CCR3. Finally, we identified a cohort of critical downstream genes of CCL7 related to cancer metastasis using Illumina deep mRNA sequencing. These findings may help better understand the molecular aspects of bone metastasis in lung cancer, and prefigure a potential clinical value for the prevention of bone recurrences.

The roles of ZEB1 in tumorigenic progression and epigenetic modifications

Highly expressed Zinc-finger E-box binding protein 1 (ZEB1) is significantly associated with the malignancy of various cancers. Signal transduction and activation of ZEB1 play important roles in cancer transformation and epithelial-mesenchymal transition (EMT). Emerging evidence suggests that ZEB1 drives the induction of EMT with activation of stem cell traits, immune evasion and epigenetic reprogramming. As an ideal target for EMT research, ZEB1 has been extensively studied for decades. However, the link between ZEB1 and epigenetic regulation of EMT has only recently been discovered. ZEB1 facilitates the epigenetic silencing of E-cadherin by recruiting multiple chromatin enzymes of E-cadherin promoter, such as histone deacetylases (HDACs), DNA methyltransferase (DNMT) and ubiquitin ligase. Destruction of the connection between ZEB1 and these chromatin-modifying enzymes may represent an efficient for treating cancer. In this review, we outlined the biological function of ZEB1 in tumorigenic progression and epigenetic modifications and elucidate its transcriptional network, which is a suitable potential target for the design of novel anticancer drugs.

LncRNA ZEB1-AS1/miR-409-3p/ZEB1 feedback loop is involved in the progression of non-small cell lung cancer

Emerging evidence has illustrated that long noncoding RNA (LncRNA) ZEB1 antisense RNA 1 (ZEB1-AS1) involved in the development of various type of human cancers. However, the role of ZEB1-AS1 in non-small cell lung cancer (NSCLC) is still elusive and poorly understood. The present study aimed to provide functional evidence and elucidate the molecular mechanisms by which the ZEB1-AS1 promotes oncogenesis of NSCLC. Our study found that ZEB1-AS1 was upregulated in NSCLC cells and knockdown of ZEB1-AS1 significantly inhibited cell growth and induced cell apoptosis. Mechanically, miR-409-3p was confirmed as a direct target of ZEB1-AS1 and negatively regulated by ZEB1-AS1 via competing endogenous RNA (ceRNA) mechanism; miR-409-3p inhibited ZEB1 expression by directly binding to the 3'UTR. Importantly, as predicted by JASPAR and further confirmed by luciferase reporter gene and ChIP assays, we found ZEB1 could bind to the promoter region of ZEB1-AS1 to activate its expression. Restoration of ZEB1 could partially abolished the action of ZEB1-AS1 silencing on cell proliferation and apoptosis. Collectively, the results suggested that ZEB1-AS1/miR-409-3p/ZEB1 constitutes a positive feedback loop to promote the tumorigenesis of NSCLC, highlighting the possibility of improving NSCLC treatment by targeting the ZEB1-AS1 signaling pathway.

Lysyl hydroxylases are transcription targets for GATA3 driving lung cancer cell metastasis

Metastasis associates with late stages of lung cancer progression and remains the main cause of patient death due to the lack of clinically effective therapeutics. Here we report that the transcription factor GATA3 and its co-factor FOG2 commonly promote the expression of the lysyl hydroxylase (LH) family members, including LH2 and LH3, which in turn drive lung adenocarcinoma cell migration, invasion, and metastasis. We show evidence that both LH2 and LH3 are direct transcription targets for GATA3. Knockdown of either LH2 or LH3 suppresses migration and invasion; on the contrary, forced expression of LH2 or LH3 promotes growth and migration, suggesting that the two LHs exert redundant oncogenic functions. Importantly, re-expression of LH2 is sufficient to restore the metastatic capacity of GATA3-depleted cells, suggesting a role for LHs as the downstream mediators of GATA3. Collectively, our data reveal a pro-metastatic GATA3-LHs axis for lung cancer, supporting the notion that targeting LHs may be useful for treating lung cancer.

TMEM106B drives lung cancer metastasis by inducing TFEB-dependent lysosome synthesis and secretion of cathepsins

Metastatic lung cancer is the leading cause of cancer-associated mortality worldwide, therefore necessitating novel approaches to identify specific genetic drivers for lung cancer progression and metastasis. We recently performed an in vivo gain-of-function genetic screen to identify driver genes of lung cancer metastasis. In the study reported here, we identify TMEM106B as a primary robust driver of lung cancer metastasis. Ectopic expression of TMEM106B could significantly promote the synthesis of enlarged vesicular lysosomes that are laden with elevated levels of active cathepsins. In a TFEB-dependent manner, TMEM106B could modulate the expression of lysosomal genes of the coordinated lysosomal expression and regulation (CLEAR) pathway in lung cancer cells and patient samples. We also demonstrate that TMEM106B-induced lysosomes undergo calcium-dependent exocytosis, thereby releasing active lysosomal cathepsins necessary for TMEM106B-mediated cancer cell invasion and metastasis in vivo, which could be therapeutically prevented by pharmacological inhibition of cathepsins. Further, in TCGA LUAD data sets, 19% of patients show elevated expression of TMEM106B, which predicts for poor disease-free and overall-survival.

Role of miR-23a/Zeb1 negative feedback loop in regulating epithelial-mesenchymal transition and tumorigenicity of intraocular tumors

Role of the two-way negative feedback regulation channel formed by miR-23a and Zeb1 in epithelial-mesenchymal transition (EMT), tumorigenic ability, and migration and metastasis capacity of the intraocular malignant tumor cells was investigated. Molecular biological methods such as real time-quantitative PCR (RT-qPCR), immunoblotting method, and immunofluorescence were used to detect the expression levels of mRNA and protein in the Zeb1 factor in OCM-1, WERI-RB1, and Y79 cells before and after miR-23a transfection. Transwell cells were used to detect the in vitro membrane permeation and migration ability in OCM-1, WERI-RB1, and Y79 cells (non-transfection group, blank control transfection group, mimic transfection group, inhibitor transfection group). The results revealed that the relative expression of miR-23a in the cells in the miR-23a mimic transfection group increased significantly compared with that in the control group (p<0.05). There were significant differences in the relative expression of mRNA between the mimic transfection and control group (p<0.05). RT-qPCR detection showed that the relative expression of mRNA of the epithelial-labeled factor E-cadherin increased significantly in the miR-23a mimics group (p<0.05). Expression of the protein E-cadherin increased while the expression of the mesenchyme-labeled proteins of vimentin and N-cadherin decreased in the mimics group. Zeb1 has a negative feedback effect on miR-23a. They can form a negative feedback loop. The results showed that miR-23a and Zeb1 form a bidirectional inhibitory negative feedback loop, which plays an important role in regulating EMT. In conclusion, the significant changes in the mesenchymal phenotype of the stable strains with Zeb1 overexpressed in the OCM-1 cells cannot be completely explained with the changes in cytoskeleton caused by EMT.

The epithelial-to-mesenchymal transition activator ZEB1 initiates a prometastatic competing endogenous RNA network

Epithelial tumor cells undergo epithelial-to-mesenchymal transition (EMT) to gain metastatic activity. Competing endogenous RNAs (ceRNAs) have binding sites for a common set of microRNAs (miRs) and regulate each other's expression by sponging miRs. Here, we address whether ceRNAs govern metastasis driven by the EMT-activating transcription factor ZEB1. High miR-181b levels were correlated with an improved prognosis in human lung adenocarcinomas, and metastatic tumor cell lines derived from a murine lung adenocarcinoma model in which metastasis is ZEB1-driven were enriched in miR-181b targets. ZEB1 relieved a strong basal repression of α1 integrin (ITGA1) mRNA, which in turn upregulated adenylyl cyclase 9 mRNA (ADCY9) by sponging miR181b. Ectopic expression of the ITGA1 3'-untranslated region reversed miR-181b-mediated metastasis suppression and increased the levels of adenylyl cyclase 9 protein (AC9), which promoted tumor cell migration and metastasis. In human lung adenocarcinomas, ITGA1 and ADCY9 levels were positively correlated, and an AC9-activated transcriptomic signature had poor-prognostic value. Thus, ZEB1 initiates a miR-181b-regulated ceRNA network to drive metastasis.

Tumor suppressor miR-128-3p inhibits metastasis and epithelial-mesenchymal transition by targeting ZEB1 in esophageal squamous-cell cancer

MicroRNAs (miRNAs) are some short RNAs that regulate multiple biological functions at post-transcriptional levels, such as tumorigenic processes, inflammatory lesions and cell apoptosis. Zinc finger E-box binding homeobox factor 1 (ZEB1) is a crucial mediator of epithelial-mesenchymal transition (EMT). It induces malignant progression of various cancers including human esophageal squamous-cell carcinoma (ESCC). In this study, we found that miR-128-3p was downregulated in ESCC tissues and cells by using PCR. Moreover, down-regulated expression of miR-128-3p was testified to be associated with poor prognosis of ESCC patients and might be regarded as an independent prognostic factor. Then, we examined the role of miR-128-3p in ESCC cells, and found that miR-128-3p could suppress the cell migration and invasion in vitro. Furthermore, ZEB1 was confirmed to be a direct target of miR-128-3p by luciferase reporter assay. Rescue experiments proved that EMT was regulated by miR-128-3p via suppression of ZEB1. Taken all together, we conclude that miR-128-3p suppresses EMT and metastasis via ZEB1, and miR-128-3p may be a critical mediator in ESCC.