Expression Of Epidermal Growth Factor Research Articles

Genetic Polymorphism of Epidermal Growth Factor Gene as a Predictor of Hepatocellular Carcinoma in Hepatitis C Cirrhotic Patients.

Background:In Egypt, the incidence of hepatocellular carcinoma (HCC) is approximately 4.7% of chronic liver disease patients due to (HCV) infection. Epidermal growth factor (EGF) plays an important role in hepatocyte regeneration. A functional polymorphism in EGF 61A>G was identified; itwas associated with higher risk of HCC. Objectives:to investigate the correlation between the epidermal growth factor (EGF) polymorphism and the risk of hepatocellular carcinoma (HCC) in hepatitis C viral (HCV) cirrhotic patients as well as its relation to EGF protein expression in HCC tissue. Patients and methods:this casecontrol study was conducted on 75 HCV cirrhotic patients including 50 HCC patients (25 withresectable HCC and 25 with advanced unresectable HCC) and 25 healthy persons were included. EGF genotype was detected by restriction fragment length polymorphism. EGF expression in HCC tissue biopsiesfrom patientswhounderwent surgical resection was done by immunohistochemical examination. Results:The GG genotype was associated with significant increased risk of HCC compared to AA genotypes (P=0.031) in cirrhotic group. The G allele had a highly significant risk of HCC compared to allele Ain recessive model GG vs. AG+AA (P=0.036) rather than in the dominant model GG +AG vs. AA (P=0.66). There was significant increased expression of EGF in tumour tissues in patients with GG genotype compared to AG genotype and AA genotype p= 0.019. Conclusion: EGF gene polymorphism (GG genotype) had a significant risk of HCC development in cirrhotic patients. This is confirmed by increased EGF expression in liver tumor tissue from HCC patients.

The Effect of Human Bone Marrow Mesenchymal Stem Cells on Epidermal Growth Factor and Epidermal Growth Factor Receptor Expression in Re-epithelialization Process in the Healing of Burns on Experimental Rats

BACKGROUND: Research on human bone marrow mesenchymal stem cells (hBM-MSCs) for burns healing has been known to increase the percentage of integrin expression of α2β1, type I collagen, transforming growth factor-β, and matrix metalloproteinases-9, but research on giving hBM-MSCs to growth factor expression in the process of re-epithelialization of burn healing has not been done.
 AIM: This study aims to the effect of hBM-MSCs given on the expression of epidermal growth factor (EGF) and EGF receptor (EGFR) in the process re-epithelialization in the healing of burn experimental rat.
 MATERIALS AND METHODS: This research is experimental with the post-test only control design, using 30 Wistar rats. Rats were divided into two groups, namely, control (phosphate-buffered saline), and the treatment was given hBM-MSCs, and stem cells were given subcutaneous doses of 2 × 106 cells/ml. Before being treated rats were anesthetized using xylazine and ketamine then the rats were burned in the dorsal (spine) with full-thickness. On the 3, 7, and 14 days, skin tissue was taken to see the expression of EGF and EGFR by immunohistochemical methods. This study was approved by the Ethics Commission of the Faculty of Medicine, Andalas University, Padang. The results of the study were analyzed by the t-test.
 RESULTS: Immunohistochemical examination of EGF and EGFR expressions after hBM-MSCs administration has significantly increased epithelialization compared with controls. Increased EGF expression was found on days 3 and 7 with moderate positive internal revenue service (IRS) assessment and on day 14 strong positive EGF expression, as well as EGFR expression on days 3 and 7 with moderate positive IRS assessment and on day 14 robust positive EGFR expression.
 CONCLUSION: This study concluded that giving of hBM-MSCs can increase the expression of EGF and EGFR which enhances the process of re-epithelialization thereby accelerating the healing of burns of experimental rats.

The investigation of the amounts and expressions of epidermal growth factor, epidermal growth factor receptor, and epidermal growth factor receptor gene polymorphisms in acne vulgaris.

Epidermal growth factor receptor inhibitors (EGFRI) used in cancer chemotherapy cause acneiform folliculitis in 70%-100% of patients in a dose-dependent manner. Acneiform folliculitis is considered to be caused by an inflammatory process due to follicular hyperkeratosis and subsequently a set of changes both in epidermis and hair follicles as a result of epidermal growth factor receptor (EGFR) blockade. Both acne vulgaris and acneiform folliculitis due to EGFRIs show similar changes in the pilosebaceous unit. Furthermore, in both groups of patients, topical application of recombinant human epidermal growth factor (EGF) has been reported to improve the disease. In this study, it was aimed to investigate the role of EGF and EGFR amount, expression, and EGFR gene polymorphisms in the etiopathogenesis of acne vulgaris. 156 acne vulgaris patients, within 18-25years of age, who had 15 or more inflammatory acne lesions on dermatologic evaluation were included in this study. The absence of any known systemic or genetic disease or cancer and any systemic or topical treatment for the last 1month were prerequisites. In the control group, 154 volunteers in the same age range who were examined at the outpatient clinic with diagnoses of melanocytic nevus, ephelid, cherry angioma, and callus and who had no more than 3 inflammatory acne lesions were recruited. The amounts of EGF and EGFR were determined by sandwich ELISA, expressions of EGF and EGFR by reverse transcriptase polymerase chain reaction; EGFR polymorphisms were examined by restriction enzyme digestion, Sanger, and high-resolution melting methods. The patient and control groups were compared in terms of EGFR gene polymorphisms in addition to the amount and expressions of EGF and EGFR. The amount of EGF in the serum was found to be significantly higher in the acne group. (P=.0012). There was no significant difference in other parameters studied. The results of our study showed a significant increase in the amount of EGF in the acne group. Though EGF may be incriminated in the etiopathogenesis of AV, the most likely explanation about its role may be controlling inflammation from the very first stage.

Evaluation of Estrogen Receptor, Progesterone Receptor, and Human Epidermal Growth Factor Receptor 2 Status Before and After Neoadjuvant Chemotherapy in Breast Cancer Patients

Evaluation of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2/neu) receptor was carried out on 80 breast cancer patients before and after neoadjuvant chemotherapy (NAC). No differences in expression were noted in 89% with reference to ER, 95% with reference to PR, and 91% with reference to HER2/neu status. A change in receptor status from positive to negative was noted in 12% for ER, 5% for PR, and 21% for HER2/neu after NAC. A negative to positive shift was noted in 11% for ER, 4% for PR, and 4% for HER2/neu after NAC. The possible reasons ascribed for change in receptor status after NAC are as follows: (1) Selection of chemoresistant clones with different receptor expression after NAC. (2) Tumor heterogeneity with variable receptor expression in different areas. (3) Ovarian suppression during NAC leading to alteration in receptor expression. (4) Technical considerations such as staining techniques and intra-observer and inter-observer differences in IHC slide interpretation before and after NAC.

Immunomodulatory effects of vitamin D3 on gene expression of MDGF, EGF and PDGFB in endometriosis

Research question: Endometriosis, an inflammatory disease, is assumed to be associated with an increased production of growth-related cytokines. Based on the emerging immunomodulatory role of vitamin D3 in different inflammatory conditions, this study aimed to examine its modulatory effect on the expression levels of the genes for platelet-derived growth factor-B (PDGFB), monocyte/macrophage-derived growth factor (MDGF, also known as PPBP) and epidermal growth factor (EGF) in peritoneal fluid mononuclear cells (PFMC) in women with and without endometriosis.Design: PFMC from 10 women with endometriosis and 10 control participants were treated with vitamin D3.The gene expression levels of PDGFB, MDGF and EGF were measured 6, 24 and 48 h following vitamin D3 administration using real-time PCR.Results: Gene expression levels of EGF and PDGFB were higher in the PFMC of women with endometriosis than the control group (P = 0.006, P < 0.001, respectively). Although MDGF expression showed an increase in the endometriosis group compared with non-endometriotic controls, no significant difference was found. Vitamin D3 significantly decreased EGF expression at 6, 24 and 48 h (P < 0.001, P < 0.001 and P = 0.007, respectively), MDGF at 24 and 48 h (P < 0.001 and P = 0.009, respectively) and PDGFB at 6 h (P = 0.047) in the endometriosis group. Vitamin D3 treatment had no significant effect on expression of the genes in the PFMC of non-endometriotic women.Conclusions: The study concluded that PDGFB and EGF gene expression increases in endometriosis, and vitamin D3 could markedly decrease this expression, suggesting its therapeutic potential in endometriosis.

The localization and expression of epidermal growth factor and epidermal growth factor receptor in bovine ovary during oestrous cycle.

Epidermal growth factor (EGF) is one of the important regulatory factors of EGF family. EGF has been indicated to effectively inhibit the apoptosis of follicular cells, to promote the proliferation of granulosa cells and the maturation of oocytes, and to induce ovulation process via binding to epidermal growth factor receptor (EGFR). However, little is known about the distribution and expression of EGF and EGFR in cattle ovary especially during oestrous cycle. In this study, the localization and expression rule of EGF and EGFR in cattle ovaries of follicular phase and luteal phase at different time points in oestrous cycle were investigated by using IHC and real-time qPCR. The results showed that EGF and EGFR in cattle ovary were mainly expressed in granulosa cells, cumulus cells, oocytes, zona pellucida, follicular fluid and theca folliculi externa of follicles. The protein and mRNA expression of EGF/EGFR in follicles changed regularly with the follicular growth wave both in follicular and in luteal phase ovaries. In follicular phase ovaries, the protein expression of EGF and EGFR was higher in antral follicles than that of those in other follicles during follicular growth stage, and the mRNA expression of EGFR was also increased in stage of dominant follicle selection. However, in luteal phase ovaries, the growth of follicles was impeded during corpus luteum development under the action of progesterone secreted by granular lutein cell. The mRNA and protein expressions of EGF and EGFR in ovarian follicles during oestrous cycle indicate that they play a role in promoting follicular development in follicular growth waves and mediating the selection process of dominant follicles.

The influence of retinol concentration in liquid crystal formula on epidermal growth factor, interleukin-6 and transglutaminase-1 mRNA expression in the epidermis.

Topical retinol application effectively reduces the effects of photoaging and improves skin condition, e.g. influences the process of keratinization of the epidermis, which improves stratum corneum structure and reduces transepidermal water loss. However, cosmetics use lower concentrations of retinol, which has been associated with emerging hypersensitivity reactions as well as redness and irritation of the skin. The question arises whether the vehicle used in the cosmetic may be important in stimulating the inflammatory reaction in the skin and if the concentration of retinol used could significantly affects the growth of epidermal cells. The aim of this study was to evaluate the effects of different concentrations of liquid crystal retinol (0.15%, 0.3% and 0.5%) on the clinical and histological characteristics of a reconstructed epidermis skin model. It also compares the effectiveness of 0.3% retinol formula in liquid crystal to that in lipid. The study used reconstructed human epidermis tissue containing normal human keratinocytes. Four original formulas containing retinol were tested: 0.15%, 0.3% and 0.5% with a liquid crystal base, and 0.3% with a lipid base. Interleukin 6 (IL-6), transglutaminase-1 (TGM1), and epidermal growth factor (EGF) mRNA expression was measured expression of the skin-equivalent tissue for 10 days of exposure. Histopathological analysis and mRNA quantification were performed. Gene expression was analyzed by total mRNA extraction. All liquid crystal formulas induced higher EGF mRNA expression than lipid base formula. IL-6 expression did not differ significantly from the DPBS reference values. Interestingly, TGM1 expression was found to increase together with increasing retinol concentration (0.15%, 0.3%, 0.5%). Histological examination revealed changes in epidermal structure, mainly hyperkeratinization of the stratum corneum. Our results support the hypothesis liquid crystal formula might be regarded as more beneficial since it inducess less pro-inflammatory action manifested by lowered expression IL-6. In addition, EGF expression was found to correlate significantly with the retinol concentration of the liquid crystal formula: 0.5% > 0.3% > 0.15% (P < 0.05). Lower concentrations may increase TGM1 expression, thus enhancing the formation of a protective layer of cornified envelope.

Narrowing the focus: Therapeutic cell surface targets for refractory triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is defined as a type of breast cancer with lack of expression of estrogen receptor, progesterone receptor and human epidermal growth factor 2 protein. In comparison to other types of breast cancer, TNBC characterizes for its aggressive behavior, more prone to early recurrence and a disease with poor response to molecular target therapy. Although TNBC is identified in only 25%-30% of American breast cancer cases annually, these tumors continue to be a therapeutic challenge for clinicians for several reasons: Tumor heterogeneity, limited and toxic systemic therapy options, and often resistance to current standard therapy, characterized by progressive disease on treatment, residual tumor after cytotoxic chemotherapy, and early recurrence after complete surgical excision. Cell-surface targeted therapies have been successful for breast cancer in general, however there are currently no approved cell-surface targeted therapies specifically indicated for TNBC. Recently, several cell-surface targets have been identified as candidates for treatment of TNBC and associated targeted therapies are in development. The purpose of this work is to review the current clinical challenges posed by TNBC, the therapeutic approaches currently in use, and provide an overview of developing cell surface targeting approaches to improve outcomes for treatment resistant TNBC.

Overexpression of LINC00691 promotes the proliferation and invasion of gastric cancer cells via the Janus kinase/signal transducer and activator of transcription signalling pathway.

This report aims to explore how LINC00691 regulates the proliferation and invasion of gastric cancer (GC). Clinical tissue and serum samples, as well as specimens in the Cancer Genome Atlas (TCGA) database, were used to analyse the expression of LINC00691 in GC. Our data indicated that the expression of LINC00691 in GC was significantly higher than that in healthy controls and was associated with clinicopathological features and survival time. In the GC cell lines MKN-45 and HGC-27, the knockdown of LINC00691 suppressed proliferation, colony formation, migration, and invasion. Bioinformatics analysis and luciferase reporter gene experiments showed that LINC00691 activated Lin28 transcription. Western blot analysis indicated that the knockdown of LINC00691 contributed to the decreased expression of p-JAK2 and p-STAT3 in GC cells. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway inhibitor ruxolitinib effectively suppressed the effects of LINC00691. In addition, both LINC00691 and Lin28 promoted the expression of epidermal growth factor (EGF). Therefore, our study clarified that LINC00691 is highly expressed in GC and is a potential biomarker for GC diagnosis and prognosis. LINC00691 promotes the proliferation and invasion of GC cells by activating Lin28 transcription and facilitating EGF expression through the JAK/STAT signalling pathway, which provides new ideas for targeted therapy of GC.

Translocation from the chloroplast stroma into the thylakoid lumen allows expression of recombinant epidermal growth factor in transplastomic tobacco plants.

Chloroplast transformation has many potential advantages for the production of recombinant proteins in plants. However, it has been reported that chloroplast expression of many proteins, such as human epidermal growth factor (hEGF), results hindered by post-transcriptional mechanisms. hEGF degradation has been related to the redox potential of the stroma and protein misfolding. To solve this problem, we proposed the redirection of hEGF into the thylakoid lumen where the environment could improve disulfide bonds formation stabilizing the functional conformation of the protein. We generated transplastomic tobacco plants targeting hEGF protein to the thylakoid lumen by adding a transit peptide (Str). Following this approach, we could detect thylakoid lumen-targeted hEGF by western blotting while stromal accumulation of hEGF remained undetectable. Southern blot analysis confirmed the integration of the transgene through homologous recombination into the plastome. Northern blot analysis showed similar levels of egf transcripts in the EGF and StrEGF lines. These results suggest that higher stability of the hEGF peptide in the thylakoid lumen is the primary cause of the increased accumulation of the recombinant protein observed in StrEGF lines. They also highlight the necessity of exploring different sub-organellar destinations to improve the accumulation levels of a specific recombinant protein in plastids.

Epidermal growth factor regulation by autophagy-mediated lncRNA H19 in murine intestinal tract after severe burn.

To investigate the regulation of epidermal growth factor (EGF) by autophagy‐mediated long non‐coding RNA (lncRNA) H19 in the intestinal tracts of severely burned mice. C57BL/6J mice received third‐degree burns to 30% of the total body surface area. Rapamycin and 3‐methyladenine (3‐MA) were used to activate and inhibit autophagy, and the changes in LC3 and Beclin1 levels were assessed by Western blotting. The effect of autophagy on lncRNA H19 was detected by qRT‐PCR. Adenovirus‐mediated overexpression of lncRNA H19 in IEC‐6 cells was used to assess the effects of lncRNA H19 on EGF and let‐7g via bioinformatics analysis, Western blotting and qRT‐PCR. let‐7g mimic/inhibitor was used to overexpress/inhibit let‐7g, and qRT‐PCR and Western blotting were used to detect the effects of let‐7g on EGF. The expression levels of LC3‐II, Beclin1 and lncRNA H19 were increased in intestinal tissues and IEC‐6 cells after rapamycin treatment but were reversed after 3‐MA treatment. LC3‐II, Beclin1 and lncRNA H19 levels increased in intestinal tissues after the burn, and these increases were more significant after rapamycin treatment but decreased after 3‐MA treatment. The lncRNA H19 overexpression in IEC‐6 cells resulted in increased and decreased expression levels of EGF and let‐7g, respectively. Furthermore, overexpression and inhibition of let‐7g resulted in decreased and increased expression of EGF, respectively. Taken together, intestinal autophagy is activated after a serious burn, which can increase the transcription level of lncRNA H19. lncRNA H19 may regulate the repair of EGF via let‐7g following intestinal mucosa injury after a burn.

EGF neutralization antibodies attenuate liver fibrosis by inhibiting myofibroblast proliferation in bile duct ligation mice

The expression of epidermal growth factor (EGF) is increased during liver fibrogenesis, and EGF receptor (EGFR) antagonist could attenuate liver fibrosis. Since EGFR is highly expressed by hepatocytes and cholangiocytes in cirrhotic liver, whether hepatic stellate cells express EGFR in response to EGF still needs exploration. Although EGFR antagonist could attenuate liver fibrosis, many ligands with EGF-like domains, besides EGF, can function through EGFR. Whether specifically blocking EGF could attenuate bile duct ligation (BDL)-induced liver fibrosis has not been revealed. BDL induced biliary infarcts and matrix deposition in mouse liver, and EGFR was expressed and phosphorylated by α-smooth muscle actin (αSMA)-positive myofibroblasts. LX-2 cells expressed EGFR, and these receptors were phosphorylated in the in vitro culture system. Growth curve and cell cycle analysis revealed that EGF could enhance cell proliferation of LX-2 cells. In addition, administration of EGF antibodies markedly reduced the EGF level in serum and the deposition of extracellular matrix in the liver of BDL mice when compared to IgG administration. Administration of EGF antibodies also reduced the phosphorylation of EGFR and the percentage of Ki-67-positive or PCNA-positive liver myofibroblasts of BDL mice when compared to IgG administration. Therefore, activated hepatic stellate cells express EGFR, thus being responsive to EGF signal, and administration of EGF antibodies could attenuate liver fibrosis by restricting the proliferation of myofibroblasts.

MiR-149 Suppresses Breast Cancer Metastasis by Blocking Paracrine Interactions with Macrophages.

Paracrine activation of cells contained in the tumor microenvironment promotes tumor progression and metastasis. In breast cancer, malignant cells recruit and educate macrophages into a M2 tumor-promoting phenotype that supports the metastatic spread of cancer cells. Here, we show that miR-149 functions as a metastasis-suppressing microRNA in breast cancer cells by limiting colony-stimulating factor-1 (CSF1)-dependent recruitment and M2 polarization of macrophages. In lymph node-positive, triple-negative breast cancer (TNBC) tissues, low miR-149 expression correlated with macrophage infiltration and reduced patient survival. By directly targeting CSF1, miR-149 expression in TNBC cell lines (MDA-MB-231 and BT-549) inhibited the recruitment of human monocytic THP-1 cells and primary human macrophages. Furthermore, in macrophages cocultured with MDA-MB-231 cells expressing miR-149, epidermal growth factor (EGF) and amphiregulin expression levels were strongly reduced, resulting in reduced EGF receptor activation in the cancer cells. In vivo, lung metastases developing from orthotopic MDA-MB-231 tumors were reduced by 75% by miR-149 expression, and this was associated with impaired M2 macrophage infiltration of the primary tumors. These data suggest that miR-149 downregulation functionally contributes to breast tumor progression by recruiting macrophages to the tumor and facilitating CSF1 and EGF receptor cross-talk between cancer cells and macrophages. SIGNIFICANCE: These findings contribute to the understanding of tumor-stroma interactions by showing that miR-149 downregulation in TNBC enhances reciprocal growth factor signaling between macrophages and cancer cells, which promotes tumor progression and metastasis. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/6/1330/F1.large.jpg.

Effects of a prostaglandin F2alpha derivative glaucoma drug on EGF expression and E-cadherin expression in a corneal epithelial cell line

Purpose: We examined the effects of travoprost on cell proliferation-related signals and E-cadherin expression in vitro and in situ in order to obtain evidence to support the hypothesis that topical travoprost impairs the integrity of the corneal epithelium.Methods: A human corneal epithelial cell culture was treated with travoprost (0.4 mg/ml) and/or PD168393 (an EGF receptor inhibitor, 10 μM). The culture was then processed for cell proliferation, an mRNA expression analysis of epidermal growth factor (EGF) and E-cadherin, and protein expression analysis of E-cadherin by immunocytochemistry and Western blotting. The eyes of C57/BL6 mice were incubated in serum-free medium plus travoprost (0.4 mg/ml) and/or PD168393 (10 μM). After being cultured for 24 h, the expression patterns of phospho-EGFR, phospho-ERK, E-cadherin, and Ki67 were immunohistochemically examined in paraffin sections.Results: The addition of travoprost up-regulated EGF mRNA expression and cell proliferation in the corneal epithelial cell culture, and this was cancelled by the addition of PD168393. This FP agonist also decreased E-cadherin expression levels in the cell–cell contact zone, and this was cancelled by the addition of PD168393. In the organ culture, the addition of travoprost to the medium up-regulated the expression of phospho-EGFR and phospho-ERK as well as cell proliferation, and down-regulated the expression of E-cadherin in the corneal epithelium, particularly in basal cells, whereas PD168393 reversed these effects.Conclusions: Travoprost activates epithelial cell proliferation by up-regulating an EGF-related signal in association with the suppression of E-cadherin localization in the cell–cell contact zone. Modulation of the EGF signal may be a strategy to minimize the negative impact of this mitogen on reformation of corneal barrier function during epithelial renewal.

The Overexpression of Epidermal Growth Factor (EGF) in HaCaT Cells Promotes the Proliferation, Migration, Invasion and Transdifferentiation to Epidermal Stem Cell Immunophenotyping of Adipose-Derived Stem Cells (ADSCs)

Background and ObjectivesThe application of adipose derived stem cells (ADSCs) in skin repair has attracted much attention nowadays. Epidermal growth factor (EGF) participates in the progress of skin proliferation, differentiation and so forth. We aimed to explore the role of EGF in the proliferation, invasion, migration and transdifferentiation into epidermal cell phenotypes of ADSCs.Methods and ResultsADSCs were extracted from adipose tissues from patient. Immunophenotyping was determined by flow cytometry. Overexpressed EGF or siEGF was transfected by lentiviruses. EGF was determined by enzyme linked immunosorbent assay (ELISA) or western blot. ADSCs and HaCaT cells were co-cultured by Transwell chambers. Conditioned medium (CM) was obtained from cultured HaCaT cells and used for the culturing of ADSCs. Cell viability was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Invasion rate was measured by Transwell invasion assay and migration rate by wound healing test. mRNA and protein levels were measured by qPCR and western blot respectively. The extracted cells from adipose tissues were identified as ADSCs by morphology and immunophenotyping. The expression of EGF was up or down regulated constantly in HaCaT cell line after transfection. EGF overexpression upregulated the proliferation, migration and invasion rates of ADSCs, and EGF expression regulated the expression of cytokeratin-19 (CK19) and integrin-β as well.ConclusionsEGF could be served as a stimulus to promote the proliferation, migration, and invasion as well as the transdifferentiation into epidermal stem cell immunophenotyping of ADSCs. The results showed that EGF had a promising effect on the repair of skin wound.

Hormone Receptors and Human Epidermal Growth Factor (HER2) Expression Change in Primary and Recurrent Breast Cancer

Background: Estrogen receptors (ER), progesterone receptors (PR), and epidermal growth factor (HER2) have a prognostic and predictive role in breast cancer. A change in the biological characteristics of the tumor can be seen during the metastatic process. This study aimed to investigate the hormone receptor and HER2 status changes between primary tumor and recurrence of breast cancer .

Heparan sulfate maintains adult midgut homeostasis in Drosophila.

Tissue homeostasis is controlled by the differentiated progeny of residential progenitors (stem cells). Adult stem cells constantly adjust their proliferation/differentiation rates to respond to tissue damage and stresses. However, how differentiated cells maintain tissue homeostasis remains unclear. Here, we find that heparan sulfate (HS), a class of glycosaminoglycan (GAG) chains, protects differentiated cells from loss to maintain intestinal homeostasis. HS depletion in enterocytes (ECs) leads to intestinal homeostasis disruption, with accumulation of intestinal stem cell (ISC)-like cells and mis-differentiated progeny. HS-deficient ECs are prone to cell death/stress and induced cytokine and epidermal growth factor (EGF) expression, which, in turn, promote ISC proliferation and differentiation. Interestingly, HS depletion in ECs results in the inactivation of decapentaplegic (Dpp) signaling. Moreover, ectopic Dpp signaling completely rescued the defects caused by HS depletion. Together, our data demonstrate that HS is required for Dpp signal activation in ECs, thereby protecting ECs from ablation to maintain midgut homeostasis. Our data shed light into the regulatory mechanisms of how differentiated cells contribute to tissue homeostasis maintenance.

Interaction of epidermal growth factor with COX-2 products and peroxisome proliferator-activated receptor-γ system in experimental rat Barrett's esophagus.

Mixed acidic-alkaline refluxate is a major pathogenic factor in chronic esophagitis progressing to Barrett's esophagus (BE). We hypothesized that epidermal growth factor (EGF) can interact with COX-2 and peroxisome proliferator-activated receptor-γ (PPARγ) in rats surgically prepared with esophagogastroduodenal anastomosis (EGDA) with healthy or removed salivary glands to deplete salivary EGF. EGDA rats were treated with 1) vehicle, 2) EGF or PPARγ agonist pioglitazone with or without EGFR kinase inhibitor tyrphostin A46, EGF or PPARγ antagonist GW9662 respectively, 3) ranitidine or pantoprazole, and 4) the selective COX-2 inhibitor celecoxib combined with pioglitazone. At 3 mo, the esophageal damage and the esophageal blood flow (EBF) were determined, the mucosal expression of EGF, EGFR, COX-2, TNFα, and PPARγ mRNA and phospho-EGFR/EGFR protein was analyzed. All EGDA rats developed chronic esophagitis, esophageal ulcerations, and intestinal metaplasia followed by a fall in the EBF, an increase in the plasma of IL-1β, TNFα, and mucosal PGE2 content, the overexpression of COX-2-, and EGF-EGFR mRNAs, and proteins, and these effects were aggravated by EGF and attenuated by pioglitazone. The rise in EGF and COX-2 mRNA was inhibited by pioglitazone but reversed by pioglitazone cotreated with GW9662. We conclude that 1) EGF can interact with PG/COX-2 and the PPARγ system in the mechanism of chronic esophagitis; 2) the deleterious effect of EGF involves an impairment of EBF and the overexpression of COX-2 and EGFR, and 3) agonists of PPARγ and inhibitors of EGFR may be useful in the treatment of chronic esophagitis progressing to BE.NEW & NOTEWORTHY Rats with EGDA exhibited chronic esophagitis accompanied by a fall in EBF and an increase in mucosal expression of mRNAs for EGF, COX-2, and TNFα, and these effects were exacerbated by exogenous EGF and reduced by removal of a major source of endogenous EGF with salivectomy or concurrent treatment with tyrphostin A46 or pioglitazone combined with EGF. Beneficial effects of salivectomy in an experimental model of BE were counteracted by PPARγ antagonist, whereas selective COX-2 inhibitor celecoxib synergistically with pioglitazone reduced severity of esophageal damage and protected esophageal mucosa from reflux. We propose the cross talk among EGF/EGFR, PG/COX-2, and proinflammatory cytokines with PPARγ pathway in the mechanism of pathogenesis of chronic esophagitis progressing to BE and EAC.

Nucleolin promotes Ang II-induced phenotypic transformation of vascular smooth muscle cells by regulating EGF and PDGF-BB.

RNA‐binding properties of nucleolin play a fundamental role in regulating cell growth and proliferation. We have previously shown that nucleolin plays an important regulatory role in the phenotypic transformation of vascular smooth muscle cells (VSMCs) induced by angiotensin II (Ang II). In the present study, we aimed to investigate the molecular mechanism of nucleolin‐mediated phenotypic transformation of VSMCs induced by Ang II. Epidermal growth factor (EGF) and platelet‐derived growth factor (PDGF) inhibitors were used to observe the effect of Ang II on phenotypic transformation of VSMCs. The regulatory role of nucleolin in the phenotypic transformation of VSMCs was identified by nucleolin gene mutation, gene overexpression and RNA interference technology. Moreover, we elucidated the molecular mechanism underlying the regulatory effect of nucleolin on phenotypic transformation of VSMCs. EGF and PDGF‐BB played an important role in the phenotypic transformation of VSMCs induced by Ang II. Nucleolin exerted a positive regulatory effect on the expression and secretion of EGF and PDGF‐BB. In addition, nucleolin could bind to the 5′ untranslated region (UTR) of EGF and PDGF‐BB mRNA, and such binding up‐regulated the stability and expression of EGF and PDGF‐BB mRNA, promoting Ang II‐induced phenotypic transformation of VSMCs.

Expression of Human Epidermal Growth Factor in Escherichia coli by Intein Approach

Different approaches are used to express recombinant proteins without the requirement of post-translational modification in Escherichia coli (E. coli). Though E. coli may have a drawback in producing endotoxin, its short division time and high expression of the final product are significant in making use as a host to produce various recombinant proteins. Inteins have been discovered in multiples microorganisms in facilitating the expression of homologous proteins and it has been used as one of the crucial tools for the production of recombinant proteins due to its unique feature in auto-excising its fusion partner, which also known as exteins. In this communication, we employed a well-established gp41-1 mini-intein to facilitate the expression of epidermal growth factor (EGF). The study revealed that though the epidermal growth factor cannot be excised from the gp41-1 mini intein during the expression, it showed the capability of gp41-1 mini intein in processing intracellular expression of soluble EGF fusion protein. Different conditions for inducing the cleavage of exteins from inteins has been studied by many research groups, and reducing condition by using the DTT works well on the C-terminal cleavage of EGF from the gp41-1 mini intein. The final purified, different concentration of EGF was mixed with homemade aqueous cream and showed to be highly active in accelerating the healing rate of patients suffering from bedsores, diabetic foot ulcers and skin rupture.