EGF-induced Cell Research Articles

MiR-125a-5p post-transcriptionally suppresses GALNT7 to inhibit proliferation and invasion in cervical cancer cells via the EGFR/PI3K/AKT pathway

BackgroundThe carcinogenesis and progression of cervical cancer is a complex process in which numerous microRNAs are involved. The purpose of this study is to investigate the role of miR-125a-5p in progression of cervical cancer.MethodsRT-qPCR was used to detect the expression of miR-125a-5p and GALNT7 in cervical cancer tissues and cell lines. Then, the miR-125a-5p mimic, miR-125a-5p inhibitor, GALNT7 siRNA, or/and pcDNA-GALNT7 were respectively transfected into HeLa and Caski cervical cancer cells, and Cell Counting kit-8 assay, Transwell assay and flow cytometry analysis were respectively used to observe cell proliferation, invasion and apoptosis. Subsequently, luciferase reporter gene assay was employed in confirming the target relationship between miR-125a-5p and GALNT7. MiR-125a-5p mimic or/and pcDNA-GALNT7 were transfected into the cervical cancer cells at the absence of epidermal growth factor (EGF) or not, and the pcDNA-GALNT7 was transfected into the cervical cancer cells at the absence of inhibitors of multiple kinases or not. Furthermore, the effect of miR-125a-5p on tumor growth was also studied using a xenograft model of nude mice.ResultsMiR-125a-5p was down-regulated in both cervical cancer tissues and cell lines and it inhibited cell proliferation and invasion of cervical cancer cells. MiR-125a-5p directly targeted and post-transcriptionally downregulated GALNT7 that was strongly upregulated in cervical cancer tissues and cell lines. Similar to the effect of miR-125a-5p mimic, silencing GALNT7 inhibited proliferation and invasion of cervical cancer cells. In addition, miR-125a-5p overexpression could counteract both GALNT7- and EGF-induced cell proliferation and invasion. GALNT7 promoted cell proliferation and invasion by activating the EGFR/PI3K/AKT kinase pathway, which could be abated by the inhibitors of the kinases. Moreover, the role of miR-125a-5p inhibited tumor formation in cervical cancer by suppressing the expression of GALNT7 in vivo.ConclusionIn conclusion, miR-125a-5p suppressed cervical cancer progression by post-transcriptionally downregulating GALNT7 and inactivating the EGFR/PI3K/AKT pathway.

Neferine inhibits epidermal growth factor-induced proliferation and migration of retinal pigment epithelial cells through downregulating p38 MAPK and PI3K/AKT signalling

Purpose: Proliferative vitreoretinopathy (PVR) occurs in approximately 5–10% of patients after retinal detachment surgery. Neferine is a bis-benzylisoquinoline alkaloid found in the green seed embryos (Nelumbo nucifera) of the lotus flower and has various properties, such as being antithrombotic, antioxidant, neuroprotective, anticancerous, and anti-inflammatory. Although the effects of neferine on the proliferation and migration of cancer cells have been partially shown, their possible role and the mechanism of action on PVR remain unclear.Materials and methods: To mimic a PVR model in vitro, retinal pigment epithelial (RPE) cells were exposed to epidermal growth factor (EGF) and treated with various concentrations of neferine. Cell viability was determined by MTT test. Cell-cycle phase distribution and cell migration were examined by image-based cytometry and wound healing test, respectively. Messenger RNA (mRNA) and protein expression were determined by RT-qPCR and Western blotting, respectively.Results: Stimulation of the cells with EGF significantly increased the rate of proliferation, whilst treatment with low concentrations of neferine-reduced proliferation to a level equal to that seen in untreated cells. Neferine significantly downregulated EGF-increased cell viability, and survivin mRNA expression was depressed to the basal level. In addition, neferine treatment contributed to cell proliferation loss by upregulating p21 and p27 expression leading to cycle arrest at the G1 phase. The treatment significantly inhibited cell migration by upregulating the expression of epithelial markers, such as E-cadherin and occludin, and decreased MMP2, MMP9, α-SMA, and vimentin. Neferine treatment markedly reduced phosphotidyl inositol 3-kinase (PI3K), AKT, p-p38 mitogen-activated protein kinase (MAPK), and NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) protein expression.Conclusion: It can be considered that neferine may be a potential candidate molecule in the treatment of PVR by inhibiting cell proliferation and the migration of EGF-induced RPE cells through the modulation of various transcriptional activities.

Anti-inflammatory effect of Rosa laevigata extract on in vitro and in vivo model of allergic asthma via the suppression of IgE and related cytokines

Exposure to a toxic stress environment leads to excessive inflammatory reactions and induces allergic asthma resulting in airway hyper-responsiveness. We investigated whether Rosa laevigata Michx. (RL) exhibits anti-inflammatory effects related allergic asthma in both an in vitro and in vivo studies. To investigate the preventive effect of RL, A549 cells were pretreated with non-toxic doses of RL (500, 1000 μg/mL) and induced by epidermal growth factor (EGF) (10 ng/mL). First, we evaluated cytotoxicity via a MTT assay. The inhibitory effects of NF-κB activity and COX-2 expression were confirmed by a western blot assay. In the in vivo study, BALB/c mice were challenged with regard to ovalbumin via an intraperitoneal injection of RL (50, 100 mg/kg) and were killed to collect bronchoalveolar lavage fluid, lung tissues and blood serum. The number of inflammatory cells, the secretion of IgE and related cytokines were monitored by ELISA and multiplex assays. RL significantly suppressed NF-κB activity and COX-2 expression levels in EGF-induced A549 cells. In a chronic inflammation mice model, pretreatment of RL attenuated allergic airway inflammation by reducing inflammatory cells, the secretion of IgE and related cytokines in a dose-dependent manner. The results of this study present the possibility of RL as a therapeutic agent for allergic asthma patients via the suppression of IgE and related cytokines.

Mechanical Control of Cell Migration by the Metastasis Suppressor Tetraspanin CD82/KAI1

The plasma membrane is a key actor of cell migration. For instance, its tension controls persistent cell migration and cell surface caveolae integrity. Then, caveolae constituents like caveolin-1 can initiate a mechano-tranduction loop that involves actin-and focal adhesions- dependent control of the mechanosensor YAP to finely tune cell migration. Tetraspanin CD82 (also named KAI-1) is an integral membrane protein and a metastasis suppressor. Its expression is lost in many cancers including breast cancer. It is a strong inhibitor of cell migration by a not well-known mechanism. We demonstrated here that CD82 controls persistent 2D migration of EGF-induced single cell, stress fibers and focal adhesion sizes and dynamics. In addition, CD82 regulates cell mechanics e.g. membrane tension, cell surface caveolae abundance and YAP nuclear translocation in a caveolin-1 dependent manner. Altogether, our data strongly suggest that CD82 controls 2D cell migration using a membrane-driven mechanical loop involving caveolin and the YAP pathway.

Sonic Hedgehog, a Novel Endogenous Damage Signal, Activates Multiple Beneficial Functions of Human Endometrial Stem Cells.

Local endometrial stem cells play an important role in regulating endometrial thickness, which is an essential factor for successful embryo implantation and pregnancy outcomes. Importantly, defects in endometrial stem cell function can be responsible for thin endometrium and subsequent recurrent pregnancy losses. Therefore, many researchers have directed their efforts toward finding a novel stimulatory factor that can enhance the regenerative capacity of endometrial stem cells. Sonic hedgehog (SHH) is a morphogen that plays a key role in regulating pattern formation throughout embryonic limb development. In addition to this canonical function, we identified for the first time that SHH is actively secreted as a stem cell-activating factor in response to tissue injury and subsequently stimulates tissue regeneration by promoting various beneficial functions of endometrial stem cells. Our results also showed that SHH exerts stimulatory effects on endometrial stem cells via the FAK/ERK1/2 and/or phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways. More importantly, we also observed that endometrial stem cells stimulated with SHH showed markedly enhanced differentiation and migratory capacities and subsequent invivo therapeutic effects in an endometrial ablation animal model.

JNK-Dependent cJun Phosphorylation Mitigates TGFβ- and EGF-Induced Pre-Malignant Breast Cancer Cell Invasion by Suppressing AP-1-Mediated Transcriptional Responses.

Transforming growth factor-β (TGFβ) has both tumor-suppressive and tumor-promoting effects in breast cancer. These functions are partly mediated through Smads, intracellular transcriptional effectors of TGFβ. Smads form complexes with other DNA-binding transcription factors to elicit cell-type-dependent responses. Previously, we found that the collagen invasion and migration of pre-malignant breast cancer cells in response to TGFβ and epidermal growth factor (EGF) critically depend on multiple Jun and Fos components of the activator protein (AP)-1 transcription factor complex. Here we report that the same process is negatively regulated by Jun N-terminal kinase (JNK)-dependent cJun phosphorylation. This was demonstrated by analysis of phospho-deficient, phospho-mimicking, and dimer-specific cJun mutants, and experiments employing a mutant version of the phosphatase MKP1 that specifically inhibits JNK. Hyper-phosphorylation of cJun by JNK strongly inhibited its ability to induce several Jun/Fos-regulated genes and to promote migration and invasion. These results show that MEK-AP-1 and JNK-phospho-cJun exhibit distinct pro- and anti-invasive functions, respectively, through differential regulation of Smad- and AP-1-dependent TGFβ target genes. Our findings are of importance for personalized cancer therapy, such as for patients suffering from specific types of breast tumors with activated EGF receptor-Ras or inactivated JNK pathways.

Melatonin attenuates epidermal growth factor-induced cathepsin S expression in ARPE-19 cells: Implications for proliferative vitreoretinopathy.

Abnormal proliferation and motility of retinal pigment epithelial cells leads to proliferative vitreoretinopathy (PVR). Melatonin is a known effective antitumour and anti-invasive agent, but whether it affects the formation and underlying mechanisms of PVR remains unclear. In this study, the results of the MTT assay, colony formation and propidium iodide (PI) staining with flow cytometry revealed that melatonin dose dependently inhibited epidermal growth factor (EGF)-induced proliferation of human ARPE-19 cells. Furthermore, melatonin reduced EGF-induced motility by suppressing cathepsin S (CTSS) expression. Pretreatment with ZFL (a CTSS inhibitor) or overexpression of CTSS (pCMV-CTSS) significantly inhibited EGF-induced cell motility when combined with melatonin. Epidermal growth factor induced the phosphorylation of AKT(S473)/mTOR (S2448) and transcription factor (c-Jun/Sp1) signaling pathways. Pretreatment of LY294002 (a PI3K inhibitor) or rapamycin (an mTOR inhibitor) markedly reduced EGF-induced motility and p-AKT/p-mTOR/c-Jun/Sp1 expression when combined with melatonin. Taken together, these data indicate that melatonin inhibited EGF-induced proliferation and motility of human ARPE-19 cells by activating the AKT/mTOR pathway, which is dependent on CTSS modulation of c-Jun/Sp1 signalling. Melatonin may be a promising therapeutic drug against PVR.

Phosphorylation of adducin-1 by cyclin-dependent kinase 5 is important for epidermal growth factor-induced cell migration

Cyclin-dependent kinase 5 (Cdk5) is predominantly expressed in neuron and plays an important role in neuronal physiology. Increasing evidence also indicates that Cdk5 may contribute to malignant progression of some types of cancers; however, the underlying mechanism remains elusive. In this study, we found that Cdk5 directly phosphorylated the actin-binding protein adducin-1 (ADD1) at T724 in vitro and in intact cells. The capability of the phosphomimetic T724D mutant to bind to actin filaments was lower than that of wild type ADD1 and the T724A mutant. Cdk5 co-localized with ADD1 at the lamellipodia upon epidermal growth factor (EGF) stimulation. The increased lamellipodia formation and cell migration of human breast cancer cells MDA-MB-231 by EGF were accompanied by Cdk5 activation and increased phosphorylation of ADD1 at T724. Depletion of Cdk5 in MDA-MB-231 cells abrogated the effects of EGF on ADD1 T724 phosphorylation, lamellipodia formation, and cell migration. Likewise, depletion of ADD1 suppressed the effects of EGF on lamellipodia formation, cell migration, and invasion, all of which were restored by FLAG-ADD1 WT and the T724D mutant, but not the T724A mutant. Together, our results suggest that phosphorylation of ADD1 at T724 by Cdk5 is important for EGF-induced cell migration and invasion.

Sudachitin, a polymethoxyflavone from Citrus sudachi, induces apoptosis via the regulation of MAPK pathways in human keratinocyte HaCaT cells

Although we recently reported that sudachitin (5,7,4′-trihydroxy-6,8,3′-trimethoxyflavone), a polymethoxyflavone isolated from the peel of Citrus sudachi, can induce apoptosis in human keratinocyte HaCaT cells, the mechanism underlying its action remains unclear. In this study, we explored the mechanisms underlying sudachitin-induced apoptosis in HaCaT cells. Sudachitin activated p38MAPK and inhibited ERK1/2, whereas another polymethoxyflavone, nobiletin (5,6,7,8,3′,4′-hexamethoxyflavone), activated ERK1/2. The p38MAPK inhibitor SB203580 significantly attenuated sudachitin-induced heat shock protein 27 phosphorylation, downstream of p38MAPK, and subsequent apoptosis, indicating that sudachitin induces apoptosis via the p38MAPK pathway. Additionally, sudachitin inhibited serum- and EGF-stimulated Raf-1-ERK1/2 activation, and blocked EGF-induced cell migration and proliferation in HaCaT cells. These results suggest that small structural differences in polymethoxyflavones can induce different cellular responses by altering the regulation of MAPK activities and that sudachitin may be a potential candidate for developing new drugs for skin diseases such as psoriasis.

C7 peptide inhibits hepatocellular carcinoma metastasis by targeting the HGF/c-Met signaling pathway

ABSTRACTHepatocellular carcinoma (HCC), characterized by a high rate of metastasis and recurrence after surgery, is caused by malignant proliferation of hepatocytes with epigenetic and/or genetic mutations. In particular, abnormal activation of the hepatocyte growth factor (HGF)-/c-mesenchymal-epithelial transition receptor (c-Met) axis is closely associated with HCC metastasis. Unfortunately, effective treatments or drugs that target the HGF/c-Met signaling pathway are still in the research pipeline. Here, a c-Met inhibitor named the C7 peptide, which can inhibit both HGF and c-Met, can significantly inhibit HGF-induced (but not EGF-induced) cell migration and suppress the phosphorylation of c-Met, Akt and Erk1/2. Moreover, the C7 peptide can also significantly suppress tumor metastasis in nude mice and the phosphorylation of c-Met. Together, our current findings, demonstrated that the C7 peptide can inhibit HGF-induced cancer cell migration and invasion through the inhibition of Akt and Erk1/2. Identification of a peptide that can block HGF/c-Met signaling provides new insight into the mechanism of HCC and future clinical treatments.

Abstract 4596: Synthesis and biological evaluation of small molecules inhibitors targeting heterotrimeric Gαi2 protein

Abstract Heterotrimeric G-proteins are ubiquitously expressed in cells, and they transduce signals from activated G-protein coupled receptors. It is well known that these proteins are differentially expressed in cancer, thereby activating signals that lead to different biological functions such as proliferation and cell motility. Previously, we have shown that Gαi2 protein is essential for cell migration and invasion in prostate cancer cell lines, and its action is downstream of PI3-kinase/Rac1 activation. We have also shown that in PC3 prostate cancer cells, pre-treated with Pertussis toxin (PTX), a well know inhibitor of Gαi/0, resulted in the attenuation of TGFβ1- and oxytocin-induced migration and PI3-kinase activation, without affecting EGF-induced PI3-kinase activation and cell migration. Here, we synthesized new small molecules inhibitors, GDIs, capable of preventing nucleotide exchange and subunit activation. Compounds #29 and #46 are analogs of the lead compound, lacking the thiophene OH-group and with a thiol- to N-methyl amino-group substitution, respectively. Compound #35, a methyl ether derivative of #46, is designed to test the effect of the modification to the phenolic group on Gαi2 inhibition activity. We pretreated PC3 cells with the small molecules and then stimulated with EGF and oxytocin to activate Gαi2 subunit. Immunoprecipitation of the active Gαi and western blot for Gαi2 showed a decrease in the amount of active Gαi2 that was pulled down compared with the controls. Using cell migration assay, we observed that #29 and #46, both at 10 μM, caused inhibition of migration in different prostate cancer cell lines in response to EGF treatments. In contrast, #35 is inactive in this assay at the same concentration. To determine if the effects of Gαi2 are the same in other cancer cells, we first knockdown Gαi2 protein expression in breast and ovarian cancer cells and performed migration assays. The knock-down of endogenous Gαi2 attenuated cell migration, compared to the control cells. We also performed migration assays in the same cells using compound #29 at 10 μM and observed significant inhibition of migratory behavior in response to EGF- and FBS stimuli compared to the controls. We conclude that the small molecules we used in this study may be considered as potential therapeutic tools, inhibiting the migratory capability of metastatic cells. Citation Format: Silvia Caggia, Autumn S. Garrett, Aditi Kumar, Subhasish Tapadar, Adegboyega K. Oyelere, Smrruthi Vaidegi Venugopal, Shafiq A. Khan. Synthesis and biological evaluation of small molecules inhibitors targeting heterotrimeric Gαi2 protein [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4596.

Prevention and relaxation effects of Liriope platyphylla on bronchial asthma in vitro model by suppressing the activities of MAPK/NF-κB pathway

Backgrounds: Bronchial asthma (BA) is a common type of asthma, defined as a chronic inflammation, hyperplasia, and hypercontraction of the airway. In this study, we investigated whether Liriope platyphylla extract (LPP) can help prevent inflammation, suppress hyperplasia, and support relaxation via regulation of MAPK/NF-κB activity. Methods: To investigate the inflammation prevention effects, A549 cells, a human airway epithelial cell line, were pretreated with various concentration of LPP and then treated with EGF recombinant (10 ng/mL). Anti-hyperplasia and muscle relaxation experiments were performed with asthma condition human bronchial smooth muscle (hBSM) cells. The effects of LPP on MAPK/NF-κB activity and MAPK/NF-κB-related signaling, such as COX-2 and iNOS expression, was analyzed through western blot analysis. The mRNA expression levels of Th-2-cell-related cytokines, including IL-6 and TNF-α, and contraction-related factors, such as PLCβ, IP3R, and MLCK, were determined by real-time PCR. Results: LPP pretreatment significantly reduced MAPK/NF-κB activity in EGF-induced asthma condition A549 cells. Therefore, there was significant suppression of both COX-2 and iNOS expression. In addition, the mRNA expression of IL-6 and TNF-α was dose depen-dently reduced. Although there was no statistical significance, factors related to contraction showed a tendency to decrease. Conclusion: Based on our results, we believe that LPP shows good potential for application as a therapeutic agent for asthma through inflammation prevention and bronchial smooth muscle relaxation.

Paxillin serine 178 phosphorylation in control of cell migration and metastasis formation through regulation of EGFR expression in breast cancer

Paxillin is a well-known multidomain scaffold protein that is involved in the regulation of cell-matrix adhesiondynamics, a process required for the tumor cell migration and invasion. Phosphorylation of the serine residue 178requires c-Jun NH2-terminal kinase (JNK) activation, which occurs downstream of epidermal growth factor receptor (EGFR)-mediated signaling and drives cell migration. In this study, we investigated the significance of paxillin Ser178 phosphorylation in breast cancer progression.We employed the rat mammary carcinoma MTLn3 cell line with which we established stabile variants of both wild type and mutant GFP-paxillin constructs. With those, we next performed several in vitro assays including cell proliferation, migration and focal adhesion dynamics. Finally, we monitored the metastatic spread of both cell line variants in an othrotopic mouse model for breast cancer.Here we show that expression of the phospho-defective mutant paxillinS178A in the metastatic mammary adenocarcinoma MTLn3 cell-line significantly decreased EGF-induced cell migration, which was correlated with impaired focal adhesion dynamics. Moreover, paxillinS178A attenuated lung metastasis formation in an orthotopic in vivo mammary gland tumor/metastasis model, demonstrating the importance of JNK-mediated paxillin phosphorylation in breast cancer progression. Expression of paxillinS178A caused a decrease in EGFR expression while re-expression of EGFR in MTLn3-paxillinS178A cells fully restored EGF-driven cell motility and focal adhesion dynamics. Furthermore, re-expression of EGFR in MTLn3-paxillinS178A rescued spontaneous metastasis from breast to lung.Overall our data show an important role for JNK-mediated paxillin Ser178 phosphorylation in the regulation of EGFR expression and thereby, in EGF-driven cell migration and metastasis formation.

Structure, antiproliferative and cancer preventive properties of sulfated α-d-fucan from the marine bacterium Vadicella arenosi

Sulfated fucose-containing glycopolymers are currently of great interest because of their wide spectrum of bioactivity, including anti-tumor properties. In this study, the structure of O-polysaccharide (OPS) of the marine bacterium Vadicella arenosi KMM 9024T, its effect on the proliferation of human breast cancer MCF-7 cells and cancer preventive properties were investigated. Two OPS fractions with different molecular weights were isolated and purified from the lipopolysaccharide by mild acid hydrolysis followed by anion-exchange chromatography. The OPS was found to consist of α-(1→3)-linked 2-O-sulfate-d-fucopyranosyl residues, whose structure was deduced by sugar analysis along with 2D NMR spectroscopy. The biological assay indicated that polysaccharide significantly reduced the proliferation and inhibited colony formation of MCF-7 cells in a dose-dependent manner. Besides, the experiment indicated the inhibitory role of polysaccharide on EGF-induced neoplastic cell transformation in mouse epidermal cells. The investigated polysaccharide is the first sulfated fucan isolated from the bacteria.

A signalling cascade involving receptor-activated phospholipase A2, glycerophosphoinositol 4-phosphate, Shp1 and Src in the activation of cell motility

BackgroundShp1, a tyrosine-phosphatase-1 containing the Src-homology 2 (SH2) domain, is involved in inflammatory and immune reactions, where it regulates diverse signalling pathways, usually by limiting cell responses through dephosphorylation of target molecules. Moreover, Shp1 regulates actin dynamics. One Shp1 target is Src, which controls many cellular functions including actin dynamics. Src has been previously shown to be activated by a signalling cascade initiated by the cytosolic-phospholipase A2 (cPLA2) metabolite glycerophosphoinositol 4-phosphate (GroPIns4P), which enhances actin polymerisation and motility. While the signalling cascade downstream Src has been fully defined, the mechanism by which GroPIns4P activates Src remains unknown.MethodsAffinity chromatography, mass spectrometry and co-immunoprecipitation studies were employed to identify the GroPIns4P-interactors; among these Shp1 was selected for further analysis. The specific Shp1 residues interacting with GroPIns4P were revealed by NMR and validated by site-directed mutagenesis and biophysical methods such as circular dichroism, isothermal calorimetry, fluorescence spectroscopy, surface plasmon resonance and computational modelling. Morphological and motility assays were performed in NIH3T3 fibroblasts.ResultsWe find that Shp1 is the direct cellular target of GroPIns4P. GroPIns4P directly binds to the Shp1-SH2 domain region (with the crucial residues being Ser 118, Arg 138 and Ser 140) and thereby promotes the association between Shp1 and Src, and the dephosphorylation of the Src-inhibitory phosphotyrosine in position 530, resulting in Src activation. As a consequence, fibroblast cells exposed to GroPIns4P show significantly enhanced wound healing capability, indicating that GroPIns4P has a stimulatory role to activate fibroblast migration. GroPIns4P is produced by cPLA2 upon stimulation by diverse receptors, including the EGF receptor. Indeed, endogenously-produced GroPIns4P was shown to mediate the EGF-induced cell motility.ConclusionsThis study identifies a so-far undescribed mechanism of Shp1/Src modulation that promotes cell motility and that is dependent on the cPLA2 metabolite GroPIns4P. We show that GroPIns4P is required for EGF-induced fibroblast migration and that it is part of a cPLA2/GroPIns4P/Shp1/Src cascade that might have broad implications for studies of immune-inflammatory response and cancer.

Bee Venom Suppresses EGF-Induced Epithelial-Mesenchymal Transition and Tumor Invasion in Lung Cancer Cells.

Bee venom of Apis mellifera is a traditional medicine in Asia. It has been used with promoting results for the treatment of pain, rheumatoid, and cancer disease. The purpose of this study was to investigate the effects of bee venom on epidermal growth factor (EGF)-induced epithelial-mesenchymal transition (EMT) in non-small cell lung cancer (NSCLC) and determine possible signaling pathway affected in EGF-induced EMT in A549 cells. Bee venom inhibited EGF-induced F-actin reorganization and cell invasion, and suppressed EGF-induced EMT, processes associated with tumor metastasis in NSCLC. Bee venom enhanced the upregulation of E-cadherin and the downregulation of vimentin and inhibited EGF-induced ERK, JNK, FAK, and mTOR phosphorylation in A549 cells. However, the inhibition of JNK phosphorylation by bee venom was not related to the inhibitory effects of EMT. Furthermore, we found that bee venom suppressed the EMT-related transcription factors ZEB2 and Slug by blocking EGF-induced ERK, FAK and mTOR phosphorylation. Bee venom inhibits EGF-induced EMT by blocking the phosphorylation of ERK, FAK, and mTOR, resulting in the suppression of ZEB2 and Slug. These data suggest bee venom as a potential antimetastatic agent for NSCLC.

Explore the action of MiRNA-21 on shikonin and epidermal growth factor in regulating the proliferation and Apoptosis of HaCaT Cell

Purpose: The aim of the study is to investigate the effect of MicroRNA-21 (miR-21) and its interaction with epidermal growth factor (EGF) and shikonin on the proliferation, and apoptosis of HaCaT cell line. Materials and Methods: HaCaT cells were cultured under different concentrations of EGF and shikonin, and to calculate their optimal effect dosages. The transfection was performed using Lipofectamine2000, and then gene expression of miR-21 was detected by quantitative real-time polymerase chain reaction (RT-PCR). MTT assay and flow cytometry were applied to test cell proliferation and apoptosis. Western blot and RT-PCR were used to detect the proliferation (proliferating cell nuclear antigen [PCNA], NF-κB/IKKβ) and apoptosis (caspase-3/caspase-9, bcl-2) signals of HaCaT cell. Results: MTT assay showed that miR-21 mimic and EGF promoted, whereas, shikonin and miR-21 inhibitor inhibited cell viability of HaCaT cell. MiR-21 was upregulated by miR-21 mimic and EGF, while downregulated by shikonin and miR-21 inhibitor. Besides, EGF and miR-21 mimic promoted proliferation-associated signals (PCNA, NF-κB/IKKβ) expression, which were suppressed by shikonin and miR-21 inhibitor. Yet, shikonin and miR-21 inhibitor induced apoptosis-related signals (caspase-3/caspase-9, bcl-2) expression while reversed by EGF and miR-21 mimic which were confirmed by the result of flow cytometry. Conclusions: MiR-21 promotes the process of EGF-induced cell growth of HaCaT. The antagonized effect of shikonin in EGF-induced proliferation and apoptosis might be mediated by suppressing the expression of miR-21.

Delphinidin inhibits epidermal growth factor‐induced epithelial‐to‐mesenchymal transition in hepatocellular carcinoma cells

Epithelial-to-mesenchymal transition (EMT), important cellular process in metastasis of primary tumors, is characterized by loss of their cell polarity, disruption of cell-cell adhesion, and gain certain properties of mesenchymal phenotype that enable migration and invasion. Delphinidin is a member of anthocyanidin belong to flavonoid groups, known as having pharmacological and physiological effects including anti-tumorigenic, antioxidative, anti-inflammatory, and antiangiogenic effects. However, the effects of delphinidin on EMT is rarely investigated. Epidermal growth factor (EGF) is known as a crucial inducer of EMT in various cancer including hepatocellular carcinoma (HCC). To determine whether delphinidin inhibits EGF-induced EMT in HCC cells, antiproliferative effect of delphinidin on Huh7 and PLC/PRF/5 cells were measured by Cell Counting Kit-8 assay. As a result, delphinidin inhibited cell proliferation in a dose-dependent manner. Based on the result of proliferation, to measure the effects of delphinidin on EGF-induced EMT, we designated a proper concentration of delphinidin, which is not affected to cell proliferation. We found that delphinidin inhibits morphological changes from epithelial to mesenchymal phenotype by EGF. Moreover, delphinidin increased the messenger RNA and protein expression of E-cadherin and decreased those of Vimentin and Snail in EGF-induced HCC cells. Also, delphinidin prevented motility and invasiveness of EGF-induced HCC cells through suppressing activation of matrix metalloproteinase 2, EGF receptor (EGFR), AKT, and extracellular signal-regulated kinase (ERK). Taken together, our findings demonstrate that delphinidin inhibits EGF-induced EMT by inhibiting EGFR/AKT/ERK signaling pathway in HCC cells.

2-Methoxy-5((3,4,5-trimethosyphenyl)seleninyl) phenol reverses EGF-induced cell migration and invasion through down-regulation of MDM2 in breast cancer cell lines

ABSTRACT2-Methoxy-5((3,4,5-trimethosyphenyl)seleninyl) phenol (SQ), a novel synthesized combretastatin A-4 (CA-4) analogue, is identified as a microtubule inhibitor and has been shown to exert anticancer activity in breast cancer cells. Here, we found that SQ reversed epidermal growth factor (EGF)-induced motility and invasion in breast cancer cell lines by the in vitro Wound healing and Transwell assay. Further studies showed that SQ treatment resulted in inhibitory alteration of EGF-stimulated epithelial-to-mesenchymal transition (EMT) and MMP-2 activity. What is more, SQ significantly inhibited the EGF-induced mouse double minute 2- (MDM2) expression and transcription factor Twist1 expression. In addition, compared with the control cells, MDM2 overexpression up-regulated Twist1 expression and dramatically promoted cell migration and invasion, MDM2 under-expression also down-regulated Twist1 expression and suppressed cell motility and invasion. Taken together, our findings suggest that the inhibitory effects of SQ on migration and invasion were related to the suppression of MDM2 and Twist1 signal axis.

Role of caveolin-1 in epidermal stem cells during burn wound healing in rats

Local transplantation of stem cells has therapeutic effects on skin damage but cannot provide satisfactory wound healing. Studies on the mechanisms underlying the therapeutic effects of stem cells on skin wound healing will be needed. Hence, in the present study, we explored the role of Caveolin-1 in epidermal stem cells (EpiSCs) in the modulation of wound healing. We first isolated EpiSCs from mouse skin tissues and established stable EpiSCs with overexpression of Caveolin-1 using a lentiviral construct. We then evaluated the epidermal growth factor (EGF)-induced cell proliferation ability using cell counting Kit-8 (CCK-8) assay and assessed EpiSC pluripotency by examining Nanog mRNA levels in EpiSCs. Furthermore, we treated mice with skin burn injury using EpiSCs with overexpression of Caveolin-1. Histological examinations were conducted to evaluate re-epithelialization, wound scores, cell proliferation and capillary density in wounds. We found that overexpression of Caveolin-1 in EpiSCs promoted EGF-induced cell proliferation ability and increased wound closure in a mouse model of skin burn injury. Histological evaluation demonstrated that overexpression of Caveolin-1 in EpiSCs promoted re-epithelialization in wounds, enhanced cellularity, and increased vasculature, as well as increased wound scores. Taken together, our results suggested that Caveolin-1 expression in the EpiSCs play a critical role in the regulation of EpiSC proliferation ability and alteration of EpiSC proliferation ability may be an effective approach in promoting EpiSC-based therapy in skin wound healing.