Expression Of EMT Markers Research Articles

TMIC-81. INCREASED LEVEL OF IGFBP2 PROMOTES TUMOR METASTASIS IN SHH MEDULLOBLASTOMA

Abstract Medulloblastoma (MB) is the most common pediatric brain malignancy. MB comprises 5 major subgroups known as WNT, SHH p53wt, SHH p53mut, Group 3 and Group 4. Among the four MB subgroups SHH group is the most dominant molecular subgroup in infants and adults. These tumors are proposed to arise from cerebellar granule neuron precursors (CGNPs), whose developmental expansion requires SHH signaling from the neighboring Purkinje neurons. Previous reports suggest that SHH group features a unique tumor microenvironment compared with other MB groups. To better understand how SHH MB cells interact with Tumor Microenvironment, we performed cytokine array analysis of culture media from SHH group Patient Tumor cells, spontaneous SHH MB mouse tumor cells and SHH MB cell lines. Further, confirmed these results using ELISA, Western blot, and immunofluorescence from human SHH MB cell lines, Smo/A1 mouse tumor primary cells and PZp53Med cell lines. In continuation to the observation of IGFBP2 expression in various cell types in single cell analysis, we analyzed the presence of IGFBP2 in astrocytes using Smo/A1 mouse tumor Immunohistochemistry. Our data showed increased levels of IGFBP2 produced by SHH MB cell lines compared to others. We analyzed the role of IGFBP2 in SHH MB tumor growth and metastasis. IGFBP2 knock-down stable cell lines showed phenotypic changes including reduced cell proliferation, cell migration and EMT. Further western blot analysis of IGFBP2 KD cells showed reduced expression of EMT markers also reduced the activation of STAT3. Our preliminary in vitro data suggest IGFBP2 exerts it metastasis-promoting role in SHH MB by regulating the expression of EMT marker proteins and matrix remodeling proteins. Further functional studies suggest that in SHH MB, IGFBP2 may regulate a STAT3-mediated EMT program to metastasize. These findings provide a strong rationale for further pursuing how IGFBP2 promotes medulloblastoma tumor cell growth and migration in vivo.

Ishophloroglucin A Ameliorates VEGF-Induced Epithelial-Mesenchymal Transition via VEGFR2 Pathway Inhibition in Microgravity-Stimulated Human Retinal Pigment Epithelial Cells.

Microgravity stimulation is associated with retinal pigment epithelial (RPE) cells that transition to mesenchymal cells (EMT), and these pathological changes cause visual impairment. Vascular endothelial growth factor (VEGF) is produced from the RPE and contributes to photoreceptor survival. However, changes in VEGF production and function under microgravity stimulation are unknown. In this study, we verified that microgravity stimulation changed the morphological characteristics of human RPE cells (ARPE19 cells) and the expression of actin cytoskeleton regulators, which are related to excessive VEGF expression. Interestingly, microgravity stimulation increased not only the production of VEGF but also the expression of EMT markers. Previously, we studied the potential of ishophloroglucin A (IPA), a phlorotannin, as an antioxidant. In silico results confirmed that IPA could structurally bind to VEGF receptor 2 (VEGFR2) among VEGFRs and inhibit the VEGF pathway. IPA significantly decreased VEGF production and EMT marker expression in microgravity-stimulated cells. It also significantly reduced excessive cell migration in VEGF-induced EMT. Overall, our findings suggested that IPA treatment decreased VEGF production and EMT marker expression in microgravity-stimulated or VEGF-treated ARPE19 cells, and this decrease in EMT could restore excessive cell migration by inhibiting the VEGF/VEGFR2 pathway. Therefore, it is a potential therapeutic candidate for angiogenesis-related eye diseases.

EZH2 regulates oncomiR-200c and EMT markers in esophageal squamous cell carcinomas

EZH2, as a histone methyltransferase, has been associated with cancer development and metastasis possibly through the regulation of microRNAs and cellular pathways such as EMT. In this study, the effect of EZH2 expression on miR-200c and important genes of the EMT pathway was investigated in esophageal squamous cell carcinoma (ESCC). Comparative qRT-PCR was used to examine EZH2 expression in ESCC lines (YM-1 and KYSE‐30) following the separately transfected silencing and ectopic expressional EZH2 vectors in ESCC. Subsequently, expression of miR-200c and EMT markers was also assessed using qRT-PCR, western blotting and immunocytochemistry. Underexpression of Mir200c was detected in YM-1 and KYSE-30 cells after EZH2 silencing, while its overexpression was observed after EZH2 induced expression. Following EZH2 silencing, downregulation of mesenchymal markers and upregulation of epithelial markers were detected in the ESCCs. Our results demonstrate that EZH2 regulates the expression of miR-200c and critical EMT genes, implying that overexpression of Zeb2, Fibronectin, N-cadherin, and Vimentin lead to a mesenchymal phenotype and morphology while underexpression of epithelial genes, enhance cell migration after enforced expression of EZH2 in ESCCs. EZH2 gene can be a beneficial treatment marker for patients with esophageal cancer through decrease invasiveness of the disease and efficient response to neoadjuvant therapy.

AhR Mediated Activation of Pro-Inflammatory Response of RAW 264.7 Cells Modulate the Epithelial-Mesenchymal Transition.

Pulmonary fibrosis, a chronic lung disease caused by progressive deterioration of lung tissue, is generated by several factors including genetic and environmental ones. In response to long-term exposure to environmental stimuli, aberrant tissue repair and epithelial cell-to- mesenchymal cell transition (EMT) trigger the subsequent progression of pulmonary fibrotic diseases. The Aryl hydrocarbon receptor (AhR) is a transcription factor that is activated by ligands providing lung dysfunction when activated by environmental toxins, such as polycyclic aromatic hydrocarbons. Our previous study demonstrated that AhR mediates α-SMA expression by directly binding to the α-SMA (fibroblast differentiation marker) promoter, suggesting the role of AhR in mediating fibrogenic progression. Here we follow the hypothesis that macrophage infiltrated microenvironments may trigger inflammation and subsequent fibrosis. We studied the expression of cytokines in RAW 264.7 cells by AhR activation through an ELISA assay. To investigate molecular events, migration, western blotting and zymography assays were carried out. We found that AhR agonists such as TCDD, IP and FICZ, promote the migration and induce inflammatory mediators such as TNF-α and G-CSF, MIP-1α, MIP-1β and MIP-2. These cytokines arbitrate EMT marker expression such as E-cadherin, fibronectin, and vimentin in pulmonary epithelial cells. Expression of proteins of MMPs in mouse macrophages was determined by zymography, showing the caseinolytic activity of MMP-1 and the gelatinolytic action of MMP-2 and MMP-9. Taken together, the present study showed that AhR activated macrophages create an inflammatory microenvironment which favours the fibrotic progression of pulmonary epithelial cells. Such production of inflammatory factors was accomplished by affecting the Wnt/β-catenin signalling pathway, thereby creating a microenvironment which enhances the epithelial-mesenchymal transition, leading to fibrosis of the lung.

Immunohistochemical expressions of EMT markers in pan-RAS-pERK1/2-positive tumors improve diagnosis and prognosis assessment of non-muscle invasive bladder cancer and muscle invasive bladder cancer patients.

Mutation or overexpression renders pan-RAS (rat sarcoma) proteins insensitive to inactivation. Activated pan-RAS communicates signal from the cell surface receptor to activate RAS-MAPK/ERK (RAS-mitogen-activated protein kinases/extracellular signal regulated kinases) signaling and orchestrates epithelial-to-mesenchymal transition-activating transcription factors (EMT-ATFs) reprogramming to induce EMT. Owing to limited studies available in bladder cancer, the present study is taken up to examine the expressions of the EMT-associated markers in pan-RAS-pERK1/2 (pan-RAS-phosphoERK1/2)-positive well-characterized cohort of forty-two non-muscle invasive bladder cancer (NMIBC) and forty-five muscleinvasive bladder cancer (MIBC) patients. Immunohistochemical staining was performed on paraffin embedded tissue sections to determine the immunolevels and cellular localization of marker proteins. Semi-quantitative expressions of pan-RAS, pERK1/2, and EMT markers (E-cadherin, Vimentin, N-cadherin, Snail, Slug Twist, and Zeb1) were statistically examined with clinicohistopathological profile of the patients using SPSS, version 20.0 software. The study documents the diagnostic relevance of immunohistochemical expressions of pan-RAS-pERK1/2/EMT-associated markers in order to stratify NMIBC and MIBC patients. Follow-up studies supported the role of altered EMT phenotype in pan-RAS-pERK1/2-activated positive tumors with disease aggressiveness. To the best of our knowledge, our study is the first concluding the impact of altered EMT phenotype via pan-RAS-pERK1/2 axis on the short survival outcome [short overall survival (OS) (p = 0.04), short progression-free survival (PFS) (p = 0.02) and short cancer-specific survival (CSS) (p = 0.03)] of muscleinvasive bladder cancer patients.

P-Phenylenediamine induces epithelial-mesenchymal transition in SV-40 immortalized human urothelial cells via the ERK5/AP-1 signaling

PurposeTo investigate whether p-Phenylenediamine (PPD) could triggered EMT inSV-40 immortalized human urothelial cells (SV-HUC-1), and the regulation role of ERK5/AP-1 during this process. Materials and methodsSV-HUC-1 cells were treated with different concentrations of PPD. MTT assay was employed to detect cell viability. Wound healing and transwell assay were performed to detect migrative and invasive capacity. Western blot and qRT-PCR were utilized for detecting molecular changes. ERK5 specific inhibitor was used to suppress ERK5 signaling. ResultsMigration and invasion capacity of SV-HUC-1cells were enhanced after PPD exposure. Expression of epithelial markers E-cadherin and ZO-1 was decreased and expression of mesenchymal markers N-cadherin and vimentin was increased after being cultured with low concentrations of PPD, indicating that PPD induced EMT in PPD-cultured SV-HUC-1 cells. Meanwhile, PPD triggered activation of ERK5signaling and downstream AP-1 was activated, but no obvious influence of PPD on other sub-families of MAPK was detected. After inhibition of ERK5/AP-1, PPD-induced enhancement of migrative and invasive abilities were attenuated and expression of EMT markers was also reversed. ConclusionPPD may be a carcinogen, which could induce EMT in SV-40 immortalized human urothelial cells (SV-HUC-1) via activating ERK5/AP-1 signaling.

LOXL2 silencing suppresses angiotensin II-induced cardiac hypertrophy through the EMT process and TGF-β1/Smad3/NF-κB pathway.

Objective(s):Atrial fibrillation (AF) is a common arrhythmia with atrial myocyte hypertrophy linked with stroke, heart failure, and increased mortality. Lysyl oxidase-like 2 (LOXL2) involves the cross-linking of collagen in the extracellular matrix (ECM). In the present study, we investigated the roles and underlying mechanisms of LOXL2 on cardiomyocyte hypertrophy. Materials and Methods: The expression of LOXL2 mRNA and protein were detected in angiotensin II (Ang II) treated rat cardiomyocytes H9c2 by RT-qPCR and western blot. Small interfering RNA (siRNA) mediated LOXL2 gene silencing was used to evaluate cardiac hypertrophy and related markers. Also, the protein expression of EMT markers and Smad3/NF-κB pathway was determined by western blot. Results:Ang II significantly increased mRNA and protein expressions of LOXL2 and increased mRNA levels of myocardial hypertrophy markers, including ANP, BNP, and β-MHC in H9c2 cells. Silencing of LOXL2 significantly suppressed Ang II-induced hypertrophy and reversed the increase in ANP, BNP, and β-MHC mRNA levels. Also, EMT markers’ expressions, as evidenced by increased E-cadherin and decreased vimentin, α-smooth muscle actin (α-SMA), fibroblast-specific protein (FSP), and collagen 1A1. Mechanistically, we found that LOXL2 silencing suppressed protein expressions of TGF-β1, p-Smad3, and p-NF-κB in Ang II-stimulated H9c2 cells. LOXL2 silencing also attenuated Ang II-induced increased expression and content of proinflammatory cytokines IL-1β (H) and TNF-α. Conclusion:Our data speculated that LOXL2 might be a potential contributing factor to Ang II-induced cardiac hypertrophy, and TGF-β1/Smad3/NF-κB is involved in a signal axis and might be a potential strategy in treating cardiac hypertrophy.

MicroRNA-375 is a therapeutic target for castration-resistant prostate cancer through the PTPN4/STAT3 axis

The functional role of microRNA-375 (miR-375) in the development of prostate cancer (PCa) remains controversial. Previously, we found that plasma exosomal miR-375 is significantly elevated in castration-resistant PCa (CRPC) patients compared with castration-sensitive PCa patients. Here, we aimed to determine how miR-375 modulates CRPC progression and thereafter to evaluate the therapeutic potential of human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes loaded with miR-375 antisense oligonucleotides (e-375i). We used miRNA in situ hybridization technique to evaluate miR-375 expression in PCa tissues, gain- and loss-of-function experiments to determine miR-375 function, and bioinformatic methods, dual-luciferase reporter assay, qPCR, IHC and western blotting to determine and validate the target as well as the effects of miR-375 at the molecular level. Then, e-375i complexes were assessed for their antagonizing effects against miR-375. We found that the expression of miR-375 was elevated in PCa tissues and cancer exosomes, correlating with the Gleason score. Forced expression of miR-375 enhanced the expression of EMT markers and AR but suppressed apoptosis markers, leading to enhanced proliferation, migration, invasion, and enzalutamide resistance and decreased apoptosis of PCa cells. These effects could be reversed by miR-375 silencing. Mechanistically, miR-375 directly interfered with the expression of phosphatase nonreceptor type 4 (PTPN4), which in turn stabilized phosphorylated STAT3. Application of e-375i could inhibit miR-375, upregulate PTPN4 and downregulate p-STAT3, eventually repressing the growth of PCa. Collectively, we identified a novel miR-375 target, PTPN4, that functions upstream of STAT3, and targeting miR-375 may be an alternative therapeutic for PCa, especially for CRPC with high AR levels.

P01 The landscape of intra-tumour heterogeneity in endocrine resistant metastatic breast cancer

Abstract Introduction Breast cancer is the most frequently diagnosed malignancy in women worldwide. Heterogeneity is a characteristic of tumour aggression and metastatic progression in breast cancer. With the power of single-cell analysis we uncovered key subpopulations within this heterogeneous landscape and specific progressive metastatic characteristics. Methods Single cell RNA sequencing was carried on three endocrine resistant ER positive xenograft tumours with varying levels of metastatic burden. Data analysis was performed using the Seurat pipeline for filtering, horizontal data integration, cell cycle regression and unsupervised clustering. Individual clusters were characterized through differentially expressed markers and PAM50 molecular subtypes distribution. Results Data integration of scRNA sequencing from primary tumours revealed seven unsupervised clusters, six of which are present in all three mice, highlighting the strong heterogeneity of breast cancer independent of metastatic outcome. PAM50 classification showed a higher distribution of luminal A cells associated with good metastatic outcome. We observed a significant difference in PAM50 distributions between the individual clusters. One cluster diverges significantly from all others and shows a decrease in luminal subtype and an increase in basal like cells. Further analysis of this cluster shows an association of selected differentially expressed markers to metastatic progression. Co-occurrence and decreased expression of several EMT markers was observed with disease progression. Conclusion High tumour heterogeneity is independent of metastatic outcomes. Downregulation of EMT related genes can be essential in metastatic progression when selected markers are co-occurring in a subpopulation. Take-home message High tumour heterogeneity is present in breast cancer independent of metastatic outcomes. Downregulation of EMT related genes can be essential in metastatic progression when selected markers are co-occurring in a subpopulation.

368-OR: Activation of a Yap1-Dependent Mesenchymal Program Promotes ß-Cell Failure

A critical contributor to the pathogenesis of type 2 diabetes is the failure of insulin-secreting β-cells due to loss of cell number or identity. However, the signaling pathways that trigger these events remain unclear. While β-cells are of endodermal origin, recent studies show endocrine cells that coexpress the mesenchymal marker vimentin in the pancreas with diabetes, although the functional features of these cells are not known. Here, we identify an epithelial-to-mesenchymal (EMT) -like program that is activated in islets of mice and humans with type 2 diabetes. Characteristics of this EMT-like program include increased protein and mRNA abundance of the EMT transcription factor Snail and the mesenchymal adhesion molecule N-cadherin. Lineage-tracing techniques demonstrate that this mesenchymal program is initiated in β-cells that become multi-hormonal, a hallmark of dysfunctional endocrine cells. Interestingly, EMT-like cells minimally express Aldh1a3, a marker of dedifferentiated β-cells. To determine the mechanism driving EMT-like activation in β-cells, we tested stressors that phenocopy the effects of diabetes in islets. Treatment of islets with mitochondrial decouplers as well as oxidative stress increased expression of EMT markers. The transcription factor Yap1 is a known inducer of EMT. While Yap1 is expressed at minimal levels in β-cells, its abundance increased in db/db islets and in primary cells with impaired mitochondrial function. Importantly, chemical inhibition of Yap1 in db/db islets reversed activation of EMT-like factors. Yap1 inhibition also improved insulin secretion. Taken together, we found activation of an EMT-like program in the endocrine pancreas of mice and humans with type 2 diabetes. This program is dependent on increases in Yap1 due to oxidative stress and impaired mitochondrial function, and results in disrupted β-cell function. Disclosure W.Mckimpson: n/a. N.Hoque: None. J.Son: None. A.Y.Lee: None. D.Accili: Advisory Panel; Lilly Diabetes. Funding NIDDK (1K01DK121873)

Bovine Pancreatic RNase A: An Insight into the Mechanism of Antitumor Activity In Vitro and In Vivo.

In this investigation, we extensively studied the mechanism of antitumor activity of bovine pancreatic RNase A. Using confocal microscopy, we show that after RNase A penetration into HeLa and B16 cells, a part of the enzyme remains unbound with the ribonuclease inhibitor (RI), resulting in the decrease in cytosolic RNAs in both types of cells and rRNAs in the nucleoli of HeLa cells. Molecular docking indicates the ability of RNase A to form a complex with Ku70/Ku80 heterodimer, and microscopy data confirm its localization mostly inside the nucleus, which may underlie the mechanism of RNase A penetration into cells and its intracellular traffic. RNase A reduced migration and invasion of tumor cells in vitro. In vivo, in the metastatic model of melanoma, RNase A suppressed metastases in the lungs and changed the expression of EMT markers in the tissue adjacent to metastatic foci; this increased Cdh1 and decreased Tjp1, Fn and Vim, disrupting the favorable tumor microenvironment. A similar pattern was observed for all genes except for Fn in metastatic foci, indicating a decrease in the invasive potential of tumor cells. Bioinformatic analysis of RNase-A-susceptible miRNAs and their regulatory networks showed that the main processes modulated by RNase A in the tumor microenvironment are the regulation of cell adhesion and junction, cell cycle regulation and pathways associated with EMT and tumor progression.

CAF-derived midkine promotes EMT and cisplatin resistance by upregulating lncRNA ST7-AS1 in gastric cancer.

This study aimed to investigate the role of cancer-associated fibroblast (CAF)-derived midkine (MK) in cisplatin (DDP) resistance. The primary cultures of CAFs and non-cancer fibroblasts (NFs) were isolated and purified. The DDP-resistant gastric cancer (GC) cells were cultured with CAF-conditioned medium. QRT-PCR and Elisa assays were employed to determine MK expression. The expression of ST7-AS1 was measured by qRT-PCR. The impact of CAFs, MK, and ST7-AS1 silencing on DDP resistance was determined by MTT and Annexin V/PI staining assay. Expression of EMT markers and PI3K/AKT was determined by Western blot and qRT-PCR. The role of MK in DDP resistance was confirmed in a xenograft model. Incubation with CAF-conditioned medium increased the IC50 to DDP. Also, incubation with CAF-conditioned medium increased cell viability, reduced cell apoptosis, and promoted EMT in DDP-resistant GC cells, which were all blocked with MK neutralization antibody treatment. MK increased the DDP resistance and upregulated the expression of ST7-AS1 in DDP-resistant GC cells. Additionally, ST7-AS1 knockdown increased the sensitivity to DDP by inhibiting EMT. Moreover, ST7-AS1 knockdown significantly decreased the phosphorylation of PI3K and AKT, and suppressed EMT, which were restored by MK addition. Finally, MK promoted tumor growth and DDP resistance in a mice model bearing the SGC-7901/DDP xenografts. CAF-derived MK promotes EMT-mediated DDP resistance via upregulation of ST7-AS1 and activation of PI3K/AKT pathway.

LINC02381-ceRNA exerts its oncogenic effect through regulation of IGF1R signaling pathway in glioma

LncRNAs play essential roles in the cellular and molecular biology of glioma. Some LncRNAs exert their role through sponging miRNAs and regulating multiple signaling pathways. LINC02381 is involved in several cancer types as either oncogene or tumor suppressor. Here, we intended to find the molecular mechanisms of the LINC02381 effect during the glioma progression in related cell lines. RNA-seq data analysis indicated the oncogenic characteristics of LINC02381, and RT-qPCR results confirmed its upregulation compared to normaltissues. Besides its expression was relatively stronger in invasive glioma cell lines. Furthermore, in silico analysis revealed LINC02381 is concentrated in the cytoplasm and predicted its sponging effect against miR-128 and miR-150, which was verified through dual luciferase assay. When LINC02381 was overexpressed in 1321N1, U87, and A172 cell lines, IGF1R and TrkC receptors as well as their downstream pathways (PI3K and RAS/MAPK), were upregulated, detected by RT-qPCR, and verified by western analysis. Consistently, LINC02381 overexpression was followed by an increased proliferation rate of transfected glioma cell lines, detected by flow cytometry and MTT assay, and RT-qPCR. It also resulted in elevated EMT and stemness markers expression level, increased migration rate, and reduced apoptosis rate, detected by RT-qPCR, western analysis, scratch test, and Annexin/PI flow cytometry analysis, respectively. The overall results indicated that LINC02381 exerts its oncogenic effect in glioma cells through sponging miR-128 and miR-150 to upregulate the IGF1R signaling pathway. Our results introduce LINC02381 and miR-128, and miR-150 as potential prognosis and therapy targets for the treatment of glioma.

Nobiletin Alleviates Ferroptosis-Associated Renal Injury, Inflammation, and Fibrosis in a Unilateral Ureteral Obstruction Mouse Model.

Nobiletin (Nob), a critical active flavonoid of citrus fruits, has received attention for its superior physical functions, which have shown to improve the progression of diseases. Chronic kidney disease (CKD) is recognized as a global health problem, and its mortality and morbidity rates are worsened with an increased risk of accompanying disorders. In this study, we aimed to elucidate whether Nob treatment ameliorates kidney fibrosis and also to identify the potential signaling networks in a unilateral ureteral obstructive (UUO) mouse model, which was used to mimic the progression of CKD. Six-week-old C57BL/6J mice were orally treated with 50 mg/kg of Nob for 14 constitutive days after UUO surgery. We found that the administration of Nob diminished kidney fibrosis and the expression of EMT markers, ameliorated oxidative stress and ferroptosis-associated injury, and mitigated the inflammatory response in the kidneys of UUO mice. Our results suggested that Nob treatment has antiferroptosis, anti-inflammatory, and antifibrotic effects, improving the progression of CKD in UUO mice. Nob may serve as a potential therapeutic candidate for the improvement of progressive CKD in further studies.

Daidzin targets epithelial-to-mesenchymal transition process by attenuating manganese superoxide dismutase expression and PI3K/Akt/mTOR activation in tumor cells

AimsEpithelial–mesenchymal transition (EMT) is a process during which epithelial cells lose their polarity and gain invasive properties to transform into mesenchymal cells. A few recent studies have reported that manganese superoxide dismutase (MnSOD) can effectively modulate EMT phenotype by influencing cellular redox environment via altering the intracellular ratio between O2− and H2O2. Daidzin (DDZ), a naturally occurring isoflavone isolated from Pueraria lobate (Fabaceae), has numerous pharmacologic effects including anti-cholesterol, anti-angiocardiopathy, anti-cancer. However, the potential inhibitory impact of DDZ on cancer metastasis and specifically on the EMT process has not been evaluated. We aimed to evaluate the possible relationship between MnSOD and EMT as well as influence of DDZ on these two processes in colon and prostate carcinoma cells. Main methodsCell viability was measured by MTT and real time cell analysis (RTCA) assay. Protein expression level of EMT markers and Akt/mTOR/PI3K signaling pathway were evaluated by Western blot analysis. Expression of EMT markers in cells was observed by immunocytochemistry. Cell invasion and migrations were evaluated by wound healing assay and Boyden chamber assay. Key findingsDDZ can block EMT accompanied with down-regulation of MnSOD, fibronectin, vimentin, MMP-9, MMP-2, N-cadherin, twist, and Snail, and up-regulation of occludin and E-cadherin in both unstimulated and TGFβ-induced cells. In addition, DDZ exposure also attenuated cell proliferation, invasion, and metastasis by reversing the EMT process in SNU-C2A, DU145, and PC-3 cells. DDZ treatment also modulated activation of PI3K/Akt/mTOR signaling cascades in DU145 cells. Moreover, an overexpression of MnSOD or silencing of MnSOD expression modulated EMT-related proteins, PI3K/Akt/mTOR activation and invasive activity. SignificanceThis is first finding on the DDZ in regulating MnSOD and EMT process by targeting PI3K/Akt/mTOR pathway in both colorectal and prostate cancer cell lines. Our data indicated that DDZ might act as a potent suppressor of EMT by affecting MnSOD expression in tumor cells.

Nuclear Respiratory Factor 1 Overexpression Inhibits Proliferation and Migration of PC3 Prostate Cancer Cells.

The role of nuclear respiratory factor 1 (NRF1) on the prostate cancer progression is controversial. We aimed to investigate the effect of NRF1 overexpression on the metastasis potential of PC3 prostate cancer cells and the associated molecular mechanisms. Cell survival, migration capacity, mitochondrial biogenesis, the expression of TGF-β signaling and EMT markers were examined after overexpression and silencing of NRF1 in PC3 cells. We found that NRF1-overexpressing cells exhibited a decreased cell viability and proliferation ability as well as a reduced migration capacity compared to control cells. Moreover, ectopic expression of NRF1 increased the mitochondrial biogenesis and inhibited the EMT characteristics, including a decrease in the mesenchymal marker, α-SMA and an increase in the epithelial cell marker, E-cadherin. We also demonstrated that overexpression of NRF1 suppressed the expression of TGF-β signaling in PC3 cells. As expected, silencing of NRF1 reversed the abovementioned effects. This study demonstrated that upregulation of NRF1 holds the potential to inhibit the metastasis of prostate cancer, possibly through an elevation of mitochondrial biogenesis and the subsequent repression of TGF-β-associated EMT. Therapeutic avenues that increase NRF1 expression may serve as an adjunct to conventional treatments of prostate cancer.

Transglutaminase 2 Maintains Hepatocyte Growth Factor Signaling to Enhance the Cancer Cell Phenotype.

Transglutaminase 2 (TG2) is a key epidermal squamous cell carcinoma cancer cell survival protein. However, how TG2 maintains the aggressive cancer phenotype is not well understood. The present studies show that TG2, which is highly expressed in epidermal cancer stem-like cells (ECS cells), maintains hepatocyte growth factor (HGF) signaling to drive an aggressive ECS cell cancer phenotype. Inhibiting TG2 reduces MET tyrosine kinase receptor expression and activity and attenuates the cancer cell phenotype. Moreover, inhibition of TG2 or HGF/MET function reduces downstream MEK1/2 and ERK1/2 activity, and this is associated with reduced cancer cell spheroid formation, invasion, and migration, and reduced stem and EMT marker expression. Treatment of TG2 knockdown cells with HGF partially restores the aggressive cancer phenotype, confirming that MET signaling is downstream of TG2. MET knockout reduces ERK1/2 signaling, doubles the time to initial tumor appearance, and reduces overall tumor growth. These findings suggest that TG2 maintains HGF/MET and MAPK (MEK1/2 and ERK1/2) signaling to drive the aggressive ECS cell cancer phenotype and tumor formation, and that TG2-dependent MET signaling may be a useful anti-cancer target. IMPLICATIONS: TG2 is an important epidermal squamous cell carcinoma stem cell survival protein. We show that TG2 activates an HGF/MET, MEK1/2 ERK1/2 signaling cascade that maintains the aggressive cancer phenotype.

Artemisinin Mediates Its Tumor-Suppressive Activity in Hepatocellular Carcinoma Through Targeted Inhibition of FoxM1.

The aberrant up-regulation of the oncogenic transcription factor Forkhead box M1 (FoxM1) is associated with tumor development, progression and metastasis in a myriad of carcinomas, thus establishing it as an attractive target for anticancer drug development. FoxM1 overexpression in hepatocellular carcinoma is reflective of tumor aggressiveness and recurrence, poor prognosis and low survival in patients. In our study, we have identified the antimalarial natural product, Artemisinin, to efficiently curb FoxM1 expression and activity in hepatic cancer cells, thereby exhibiting potential anticancer efficacy. Here, we demonstrated that Artemisinin considerably mitigates FoxM1 transcriptional activity by disrupting its interaction with the promoter region of its downstream targets, thereby suppressing the expression of numerous oncogenic drivers. Augmented level of FoxM1 is implicated in drug resistance of cancer cells, including hepatic tumor cells. Notably, FoxM1 overexpression rendered HCC cells poorly responsive to Artemisinin-mediated cytotoxicity while FoxM1 depletion in resistant liver cancer cells sensitized them to Artemisinin treatment, manifested in lower proliferative and growth index, drop in invasive potential and repressed expression of EMT markers with a concomitantly increased apoptosis. Moreover, Artemisinin, when used in combination with Thiostrepton, an established FoxM1 inhibitor, markedly reduced anchorage-independent growth and displayed more pronounced death in liver cancer cells. We found this effect to be evident even in the resistant HCC cells, thereby putting forth a novel combination therapy for resistant cancer patients. Altogether, our findings provide insight into the pivotal involvement of FoxM1 in the tumor suppressive activities of Artemisinin and shed light on the potential application of Artemisinin for improved therapeutic response, especially in resistant hepatic malignancies. Considering that Artemisinin compounds are in current clinical use with favorable safety profiles, the results from our study will potentiate its utility in juxtaposition with established FoxM1 inhibitors, promoting maximal therapeutic efficacy with minimal adverse effects in liver cancer patients.

Co-Expression of CD34, CD90, OV-6 and Cell-Surface Vimentin Defines Cancer Stem Cells of Hepatoblastoma, Which Are Affected by Hsp90 Inhibitor 17-AAG.

Cancer stem cells (CSCs) are nowadays one of the major focuses in tumor research since this subpopulation was revealed to be a great obstacle for successful treatment. The identification of CSCs in pediatric solid tumors harbors major challenges because of the immature character of these tumors. Here, we present CD34, CD90, OV-6 and cell-surface vimentin (csVimentin) as reliable markers to identify CSCs in hepatoblastoma cell lines. We were able to identify CSC characteristics for the subset of CD34+CD90+OV-6+csVimentin+-co-expressing cells, such as pluripotency, self-renewal, increased expression of EMT markers and migration. Treatment with Cisplatin as the standard chemotherapeutic drug in hepatoblastoma therapy further revealed the chemo-resistance of this subset, which is a main characteristic of CSCs. When we treated the cells with the Hsp90 inhibitor 17-AAG, we observed a significant reduction in the CSC subset. With our study, we identified CSCs of hepatoblastoma using CD34, CD90, OV-6 and csVimentin. This set of markers could be helpful to estimate the success of novel therapeutic approaches, as resistant CSCs are responsible for tumor relapses.

Reducing tumor invasiveness by ramucirumab and TGF‐β receptor kinase inhibitor in a diffuse‐type gastric cancer patient‐derived cell model

BackgroundDiffuse‐type gastric cancer (GC) is known to be more aggressive and relatively resistant to conventional chemotherapy. Hence, more optimized treatment strategy is urgently needed in diffuse‐type GC.MethodsUsing a panel of 10 GC cell lines and 3 GC patient‐derived cells (PDCs), we identified cell lines with high EMTness which is a distinct feature for diffuse‐type GC. We treated GC cells with high EMTness with ramucirumab alone, TGF‐β receptor kinase inhibitor (TEW‐7197) alone, or in combination to investigate the drug's effects on invasiveness, spheroid formation, EMT marker expression, and tumor‐induced angiogenesis using a spheroid‐on‐a‐chip model.ResultsBoth TEW‐7197 and ramucirumab treatments profoundly decreased invasiveness of EMT‐high cell lines and PDCs. With a 3D tumor spheroid‐on‐a‐chip, we identified versatile influence of co‐treatment on cancer cell‐induced blood vessel formation as well as on EMT progression in tumor spheroids. The 3D tumor spheroid‐on‐a‐chip demonstrated that TEW‐7197 + ramucirumab combination significantly decreased PDC‐induced vessel formation.ConclusionsIn this study, we showed TEW‐7197 and ramucirumab considerably decreased invasiveness, thus EMTness in a panel of diffuse‐type GC cell lines including GC PDCs. Taken together, we confirmed that combination of TEW‐7197 and ramucirumab reduced tumor spheroid and GC PDC‐induced blood vessel formation concomitantly in the spheroid‐on‐a‐chip model.