Therapeutic vaccines for advanced non-small cell lung cancer

BACKGROUND

New strategies in immunotherapy with specific antigens that trigger an anti-tumour immune response in people with lung cancer open the possibility of developing therapeutic vaccines aimed at boosting the adaptive immune response against cancer cells.

OBJECTIVES

To evaluate the effectiveness and safety of different types of therapeutic vaccines for people with advanced non-small cell lung cancer.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Wanfang Data, and China Journal Net (CNKI) up to 22 August 2023.

SELECTION CRITERIA

We included parallel-group, randomised controlled trials evaluating a therapeutic cancer vaccine, alone or in combination with other treatments, in adults (> 18 years) with advanced non-small cell lung cancer (NSCLC), whatever the line of treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were overall survival, progression-free survival, and serious adverse events; secondary outcomes were three- and five-year survival rates and health-related quality of life.

MAIN RESULTS

We included 10 studies with 2177 participants. The outcome analyses included only 2045 participants (1401 men and 644 women). The certainty of the evidence varied by vaccine and outcome, and ranged from moderate to very low. We report only the results for primary outcomes here. TG4010 The addition of the vector-based vaccine, TG4010, to chemotherapy, compared with chemotherapy alone in first-line treatment, may result in little to no difference in overall survival (hazard ratio (HR) 0.83, 95% confidence interval (CI) 0.65 to 1.05; 2 studies, 370 participants; low-certainty evidence). It may increase progression-free survival slightly (HR 0.74, 95% CI 0.55 to 0.99; 1 study, 222 participants; low-certainty evidence). It may result in little to no difference in the proportion of participants with at least one serious treatment-related adverse event, but the evidence is very uncertain (risk ratio (RR) 0.70, 95% CI 0.23 to 2.19; 2 studies, 362 participants; very low-certainty evidence). Epidermal growth factor vaccine Epidermal growth factor vaccine, compared to best supportive care as switch maintenance treatment after first-line chemotherapy, may result in little to no difference in overall survival (HR 0.82, 95% CI 0.66 to 1.02; 1 study, 378 participants; low-certainty evidence), and in the proportion of participants with at least one serious treatment-related adverse event (RR 1.32, 95% CI 0.88 to 1.98; 2 studies, 458 participants; low-certainty evidence). hTERT (vx-001) The hTERT (vx-001) vaccine compared to placebo as maintenance treatment after first-line chemotherapy may result in little to no difference in overall survival (HR 0.97, 95% CI 0.70 to 1.34; 1 study, 190 participants). Racotumomab Racotumomab compared to placebo as a switch maintenance treatment post-chemotherapy was assessed in one study with 176 participants. It may increase overall survival (HR 0.63, 95% CI 0.46 to 0.87). It may make little to no difference in progression-free survival (HR 0.73, 95% CI 0.53 to 1.00) and in the proportion of people with at least one serious treatment-related adverse event (RR 1.03, 95% CI 0.15 to 7.18). Racotumomab versus docetaxel as switch maintenance therapy post-chemotherapy was assessed in one study with 145 participants. The study did not report hazard rates on overall survival or progression-free survival time, but the difference in median survival times was very small - less than one month. Racotumomab may result in little to no difference in the proportion of people with at least one serious treatment-related adverse event compared with docetaxel (RR 0.89, 95% CI 0.44 to 1.83). Personalised peptide vaccine Personalised peptide vaccine plus docetaxel compared to docetaxel plus placebo post-chemotherapy treatment may result in little to no difference in overall survival (HR 0.80, 95% CI 0.42 to 1.52) and progression-free survival (HR 0.78, 95% CI 0.43 to 1.42). OSE2101 The OSE2101 vaccine compared with chemotherapy, after chemotherapy or immunotherapy, was assessed in one study with 219 participants. It may result in little to no difference in overall survival (HR 0.86, 95% CI 0.62 to 1.19). It may result in a small difference in the proportion of people with at least one serious treatment-related adverse event (RR 0.95, 95% CI 0.91 to 0.99). SRL172 The SRL172 vaccine of killed Mycobacterium vaccae, added to chemotherapy, compared to chemotherapy alone, may result in no difference in overall survival, and may increase the proportion of people with at least one serious treatment-related adverse event (RR 2.07, 95% CI 1.76 to 2.43; 351 participants).

AUTHORS' CONCLUSIONS

Adding a vaccine resulted in no differences in overall survival, except for racotumomab, which showed some improvement compared to placebo, but the difference in median survival time was very small (1.4 months) and the study only included 176 participants. Regarding progression-free survival, we observed no differences between the compared treatments, except for TG4010, which may increase progression-free survival slightly. There were no differences between the compared treatments in serious treatment-related adverse events, except for SRL172 (killed Mycobacterium vaccae) added to chemotherapy, which was associated with an increase in the proportion of participants with at least one serious treatment-related adverse event, and OSE2101, which may decrease slightly the proportion of people having at least one serious treatment-related adverse event. These conclusions should be interpreted cautiously, as the very low- to moderate-certainty evidence prevents drawing solid conclusions: many vaccines were evaluated in a single study with small numbers of participants and events.

Milk fat globule epidermal growth factor 8 alleviates liver injury in severe acute pancreatitis by restoring autophagy flux and inhibiting ferroptosis in hepatocytes

BACKGROUND

Liver injury is common in severe acute pancreatitis (SAP). Excessive autophagy often leads to an imbalance of homeostasis in hepatocytes, which induces lipid peroxidation and mitochondrial iron deposition and ultimately leads to ferroptosis. Our previous study found that milk fat globule epidermal growth factor 8 (MFG-E8) alleviates acinar cell damage during SAP via binding to αvβ3/5 integrins. MFG-E8 also seems to mitigate pancreatic fibrosis via inhibiting chaperone-mediated autophagy.

AIM

To speculate whether MFG-E8 could also alleviate SAP induced liver injury by restoring the abnormal autophagy flux.

METHODS

SAP was induced in mice by 2 hly intraperitoneal injections of 4.0 g/kg L-arginine or 7 hly injections of 50 μg/kg cerulein plus lipopolysaccharide. mfge8-knockout mice were used to study the effect of MFG-E8 deficiency on SAP-induced liver injury. Cilengitide, a specific αvβ3/5 integrin inhibitor, was used to investigate the possible mechanism of MFG-E8.

RESULTS

The results showed that MFG-E8 deficiency aggravated SAP-induced liver injury in mice, enhanced autophagy flux in hepatocyte, and worsened the degree of ferroptosis. Exogenous MFG-E8 reduced SAP-induced liver injury in a dose-dependent manner. Mechanistically, MFG-E8 mitigated excessive autophagy and inhibited ferroptosis in liver cells. Cilengitide abolished MFG-E8's beneficial effects in SAP-induced liver injury.

CONCLUSION

MFG-E8 acts as an endogenous protective mediator in SAP-induced liver injury. MFG-E8 alleviates the excessive autophagy and inhibits ferroptosis in hepatocytes by binding to integrin αVβ3/5.

N-glycan profiling of tissue samples to aid breast cancer subtyping

Breast cancer is a highly heterogeneous disease. Its intrinsic subtype classification for diagnosis and choice of therapy traditionally relies on the presence of characteristic receptors. Unfortunately, this classification is often not sufficient for precise prediction of disease prognosis and treatment efficacy. The N-glycan profiles of 145 tumors and 10 healthy breast tissues were determined using Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry. The tumor samples were classified into Mucinous, Lobular, No-Special-Type, Human Epidermal Growth Factor 2 + , and Triple-Negative Breast Cancer subtypes. Statistical analysis was conducted using the reproducibility-optimized test statistic software package in R, and the Wilcoxon rank sum test with continuity correction. In total, 92 N-glycans were detected and quantified, with 59 consistently observed in over half of the samples. Significant variations in N-glycan signals were found among subtypes. Mucinous tumor samples exhibited the most distinct changes, with 28 significantly altered N-glycan signals. Increased levels of tri- and tetra-antennary N-glycans were notably present in this subtype. Triple-Negative Breast Cancer showed more N-glycans with additional mannose units, a factor associated with cancer progression. Individual N-glycans differentiated Human Epidermal Growth Factor 2 + , No-Special-Type, and Lobular cancers, whereas lower fucosylation and branching levels were found in N-glycans significantly increased in Luminal subtypes (Lobular and No-Special-Type tumors). Clinically normal breast tissues featured a higher abundance of signals corresponding to N-glycans with bisecting moiety. This research confirms that histologically distinct breast cancer subtypes have a quantitatively unique set of N-glycans linked to clinical parameters like tumor size, proliferative rate, lymphovascular invasion, and metastases to lymph nodes. The presented results provide novel information that N-glycan profiling could accurately classify human breast cancer samples, offer stratification of patients, and ongoing disease monitoring.

Use of Intralesional and Perilesional Human Recombinant Epidermal Growth Factor (hrEGF) in the Local Treatment of Venous Ulcer - Review Article - Expert Recommendation

Venous Ulcers (VU) represent 60-80% of all leg ulcers and are the final stage of the disease secondary to venous hypertension or valve insufficiency. Conventional treatment that focuses on its etiological factors continues to be the gold standard; however, 30% of ulcers do not heal with this treatment; thus, it has been seen that the use of growth factor can be used as an adjuvant for this pathology. A literature review was carried out to evaluate the evidence from systematic reviews, meta-analyses, case studies, and quantitative studies that respond to the objective of this analysis review in the different databases with specific inclusion criteria with publications between 2002 and 2022, initially finding the topical application of the factor and later, more recently, the intralesional and perilesional application, the latter being an alternative treatment for this type of pathology and generating some recommendations for using the Factor.

Dual-potential electrochemiluminescence cytosensor based on a metal-organic framework and ABEI-PEI-Au@AgNPs for the simultaneous determination of phosphatidylserine and epidermal growth factor receptors on an apoptotic cell surface

A new electrochemiluminescence (ECL) cytosensor is proposed for the simultaneous determination of phosphatidylserine (PS) and epidermal growth factor receptor (EGFR) based on the ECL signals of metal-organic framework-5 (MOF-5) loaded CdS quantum dots and N-(aminobutyl)-N-(ethylisoluminol)-polyethylenimine capped Au and Ag nanoparticles. Apoptosis promotes the exposure of PS and reduces the expression of EGFR in cell membranes. Two spatially resolved areas on dual-disk glassy carbon electrodes were designed to eliminate the interference from different ECL probes. Using HepG2 cells treated with resveratrol to induce apoptosis, the cytosensor exhibited high sensitivity, simplicity, and high reproducibility, demonstrating its potential in drug screening and rapid apoptotic cell detection. The strategy reported provides a promising platform for the highly sensitive cytosensing and convenient screening of clinically relevant anticancer drugs.

Comparative efficacy of growth factor therapy in healing diabetes-related foot ulcers: A network meta-analysis of randomized controlled trials

INTRODUCTION

This study examined the relative efficacy of growth factor therapies in healing diabetes-related foot ulcers (DFU).

METHODS

PubMed and Cochrane databases were searched for randomized controlled trials testing growth factor therapies for treating DFU. The primary outcome was complete wound closure. Results were reported as relative risk (RR) ± 95% credible intervals (CrI). The risk of bias was assessed using Cochrane's RoB-2 tool.

RESULTS

A total of 31 RCTs involving 2174 participants were included. Only 13 of the trials (n = 924) reported on the aetiology of the ulcers (85.4% neuropathic and 14.6% ischaemic). Epidermal growth factor (RR 3.83; 95% CrI 1.81, 9.10), plasma-rich protein (PRP) (RR 3.36; 95% CrI 1.66, 8.03) and platelet-derived growth factor (PDGF) (RR 2.47; 95% CrI 1.23, 5.17) significantly improved the likelihood of complete ulcer healing compared to control. Sub-analyses suggested that PRP (3 trials - RR 9.69; 95% CrI 1.37, 103.37) and PDGF (6 trials - RR 2.22; 95% CrI 1.12, 5.19) significantly improved the likelihood of wound closure amongst trial mainly recruiting participants with neuropathic ulcers. Eleven trials had a low risk of bias, 9 had some concerns and 11 had a high risk of bias. Sub-analysis of trials with a low risk of bias suggested that none of the growth factors significantly improved ulcer healing compared with control.

DISCUSSION

This network meta-analysis found low-quality evidence that Epidermal growth factor, PRP and PDGF therapy improved DFU healing likelihood compared with control. Larger well-designed trials are needed.

Mercury-associated neural epidermal growth factor-like 1 protein (NELL-1) positive membranous nephropathy after use of skin lightening creams

INTRODUCTION

Membranous nephropathy, one of the common causes of glomerulonephritis worldwide, is reported in association with mercury exposure. Neural epidermal growth factor-like 1 protein is a recently described target antigen in membranous nephropathy.

CASE SERIES

Three woman (ages 17, 39, and 19 years old) presented sequentially for our evaluation with complaints consistent with nephrotic syndrome. All three had nephrotic range proteinuria, hypoalbuminemia, hypercholesterolemia, hypothyroidism, and inactive urinary sediments. Kidney biopsies were performed in the first two patients, which demonstrated findings consistent with membranous nephropathy and positive staining for neural epidermal growth factor-like 1 protein. On discovery that they were all using the same skin-lightening cream, samples of the cream were tested and found to contain between 2,180 parts per million and 7,698 parts per million of mercury. Elevated urine and blood mercury concentrations were also found in the first two patients. All three patients improved following cessation of use and treatment with levothyroxine (all three patients) and corticosteroids and cyclophosphamide in patients one and two.

DISCUSSION

We hypothesize the role of autoimmunity triggered by mercury exposure in the pathogenesis of neural epidermal growth factor-like 1 protein membranous nephropathy.

CONCLUSION

Mercury exposure should be carefully assessed as a part of the evaluation of patients with neural epidermal growth factor-like 1 protein positive membranous nephropathy.

Anti-Tr/DNER Antibody-Associated Cerebellar Ataxia: a Systematic Review

Rapidly progressive cerebellar ataxia is a classical paraneoplastic neurological syndrome associated with different autoantibodies and typical demographic characteristics, extracerebellar signs, tumor association, and prognosis. Anti-Tr/anti-Delta/Notch-like epidermal growth factor-related receptor (DNER) antibody is one of the associated antibodies. Given the rarity of this condition, our current knowledge is based on case reports and small case series. In order to improve our understanding of these conditions, we conducted a systematic review of the literature. Our study followed the PRISMA reporting guidelines. Studies of patients with the presence of anti-Tr/DNER antibodies in serum or cerebrospinal fluid (CSF) were included. We extract data information related to study characteristics, demographics, clinical symptoms, tumor association, neuroimaging, and cerebrospinal fluid analysis. Out of 131 records, we analyzed 17 papers, including a total of 85 patients with anti-Tr/DNER antibody-associated cerebellar ataxia. We confirmed that this disease occurred mostly in middle-aged males. Isolated cerebellar ataxia was the most common presentation. Extracerebellar features were rare (8%). Ninety-one percent of the patients presented an associated tumor, being Hodgkin lymphoma the most common. Abnormal neuroimaging patterns included cerebellar atrophy (19%) and cerebellar hypersignal (6%). Cerebrospinal fluid was inflammatory in 64% of the patients. Oncological response was complete in 88%, but neurological prognosis was poor with only 41% of the patients presenting significant neurological improvement at the last follow up. Anti-Tr/DNER antibodies should be tested in rapid progressive cerebellar ataxia. Oncological response is excellent; however, many patients do not improve from their cerebellar ataxia.

Enzyme Prodrug Therapy with Photo-Cross-Linkable Anti-EGFR Affibodies Conjugated to Upconverting Nanoparticles

In this work, we demonstrate that a photo-cross-linkable conjugate of upconverting nanoparticles and cytosine deaminase can catalyze prodrug conversion specifically at tumor sites in vivo. Non-covalent association of proteins and peptides with cellular surfaces leads to receptor-mediated endocytosis and catabolic degradation. Recently, we showed that covalent attachment of proteins such as affibodies to cell receptors yields extended expression on cell surfaces with preservation of protein function. To adapt this technology for in vivo applications, conjugates were prepared from upconverting nanoparticles and fusion proteins of affibody and cytosine deaminase enzyme (UC-ACD). The affibody allows covalent photo-cross-linking to epidermal growth factor receptors (EGFRs) overexpressed on Caco-2 human colorectal cancer cells under near-infrared (NIR) light. Once bound, the cytosine deaminase portion of the fusion protein converts the prodrug 5-fluorocytosine (5-FC) to the anticancer drug 5-fluorouracil (5-FU). NIR covalent photoconjugation of UC-ACD to Caco-2 cells showed 4-fold higher retention than observed with cells that were not irradiated in vitro. Next, athymic mice expressing Caco-2 tumors showed 5-fold greater UC-ACD accumulation in the tumors than either conjugates without the CD enzyme or UC-ACDs in the absence of NIR excitation. With oral administration of 5-FC prodrug, tumors with photoconjugated UC-ACD yielded 2-fold slower growth than control groups, and median mouse survival increased from 28 days to 35 days. These experiments demonstrate that enzyme-decorated nanoparticles can remain viable after a single covalent photoconjugation in vivo, which can in turn localize prodrug conversion to tumor sites for multiple weeks.

Killing two birds with one stone: miR-126 involvement in both cancer and atherosclerosis

OBJECTIVE

Both cancer and atherosclerosis are the main causes of morbidity and mortality in the world, and some patients even suffer from both of them. Several studies have shown an association between the pathogenesis of cancer and atherosclerosis. It has been reported that miR-126 may participate in the pathological process of cancer and atherosclerosis. Therefore, we aimed to summarize the role of miR-126 in cancer and atherosclerosis respectively, as well as a possible association between them.

MATERIALS AND METHODS

In this paper, "miR-126" and "microRNA-126" are used as the first group of keywords, "atheromatosis" and "atherosclerosis" are used as the second group of keywords, and "tumor" and "cancer" are used as the third group of keywords. In PubMed, the authors selected one of the first group and the second group of keywords to search the literature related to miR-126 and cancer, and one of the first group and the third group of keywords was selected to search the literature on miR-126 and atherosclerosis. All collected articles are from 2021 and before. Irrelevant, withdrawn and review articles were excluded, and the included literature was mainly in the recent five years.

RESULTS

After collection and summary, miR-126 is found involved in cell apoptosis, proliferation, angiogenesis, inflammation, and other processes in both cancer and atherosclerosis by negatively targeting PI3K, VEGF, VCAM-1, EGFL7, CXCL12-CXCR4 axis, and LRP6. Moreover, we briefly review the prospects of miR-126 as a biomarker for the diagnosis and treatment of cancer and atherosclerosis in clinical applications.

CONCLUSIONS

It has been demonstrated that miR-126 can influence cancer and atherosclerosis by affecting the same or different target genes. Therefore, it facilitates our understanding of the common prevention and treatment strategies of cancer and atherosclerosis by regulating the miR-126-target genes network.

Lipoic acid supplementation associated with neural epidermal growth factor-like 1 (NELL1)-associated membranous nephropathy

Lipoic acid (alpha lipoic acid, thioctic acid) is a popular over-the-counter antioxidant and insulin-mimetic supplement under investigation in a variety of conditions including multiple sclerosis, diabetes, and schizophrenia. Unfortunately, high-grade proteinuria was an unexpected adverse event specific to the treatment arm of our clinical trial investigating lipoic acid supplementation in patients with multiple sclerosis. This observation led to detection of similar patients in our nephrology practice. Here, we describe four biopsy-proven cases of neural epidermal growth factor-like 1 (NELL1)-associated membranous nephropathy following lipoic acid supplementation and a fifth suspected case. Discontinuation of lipoic acid and supportive therapy resulted in remission.

A Randomized Controlled Trial on the Effectiveness of Epidermal Growth Factor-Containing Ointment on the Treatment of Solar Lentigines as Adjuvant Therapy

Background and Objective: Little is known about the anti-pigmentation effects of whitening agents on solar lentigines. Epidermal growth factor (EGF) has been used as a booster for wound healing in the skin, and it has been suggested to have anti-pigmentation effects. This study aimed to evaluate the effect and safety of EGF-containing ointment for treating solar lentigines with a Q-switched (QS) 532 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (Bluecore company, Seoul, Republic of Korea). Materials and Methods: Subjects who underwent QS 532 nm Nd:YAG laser treatment of solar lentigines were randomly assigned to treatment with an EGF ointment or petrolatum. After the laser procedure, the subjects were administered the test ointment twice a day for 4 weeks. The physician's assessment of the degree of pigment clearance and patient's satisfaction were assessed after 4 and 8 weeks. Additionally, the melanin index (MI), erythema index (EI), transepidermal water loss (TEWL), and post-inflammatory hyperpigmentation (PIH) were evaluated. This trial was registered with ClinicalTrials.gov (NCT04704245). Results: The blinded physician's assessment using 5-grade percentage improvement scale and patient's satisfaction were significantly higher in the study group than in the control group at the 4th and 8th weeks. The MI was significantly higher in the control group than in the study group at the 4th and 8th weeks. The EI and TEWL did not differ significantly between the two groups at either time point. The incidence of PIH was higher in the control group (37.5%) than in the EGF group (7.14%) at the 8th week. Conclusions: The application of EGF-containing ointment on facial solar lentigines with a QS 532 nm Nd:YAG laser showed efficient and safe therapeutic effects, with less PIH. Thus, EGF-containing ointment could be suggested as the promising adjuvant treatment strategy with a QS laser for solar lentigines.

Immunohistochemical evaluation of the prognostic and predictive power of epidermal growth factor receptor ligand levels in patients with metastatic colorectal cancer

For patients with metastatic colorectal cancer (mCRC), epidermal growth factor receptor (EGFR) inhibitors are limited to patients with RAS wild-type tumours. Not all patients will benefit from treatment and better predictive biomarkers are needed. Here we investigated the prognostic and predictive impact of the EGFR ligands amphiregulin (AREG) and epiregulin (EREG). Expression levels were assessed by immunohistochemistry on 99 KRAS wild-type tumours. AREG and EREG positivity was seen in 49% and 50% of cases, respectively. No difference in expression was observed by primary tumour side. There was no significant difference in OS by AREG or EREG expression. In the subset of patients who received an EGFR inhibitor, EREG positivity was associated with longer OS (median 34.0 vs. 27.0 months, p = 0.033), driven by a difference in patients with a left-sided primary (HR 0.37, p = 0.015). Our study supports further investigation into EREG as a predictive biomarker in mCRC.

The EGFL7-ITGB3-KLF2 axis enhances survival of multiple myeloma in preclinical models

Angiogenic factors play a key role in multiple myeloma (MM) growth, relapse, and drug resistance. Here we show that malignant plasma cells (cell lines and patient-derived MM cells) express angiocrine factor EGF like-7 (EGFL7) mRNA and protein. MM cells both produced EGFL7 and expressed the functional EGFL7 receptor integrin β 3 (ITGB3), resulting in ITGB3 phosphorylation and focal adhesion kinase activation. Overexpression of ITGB3 or EGFL7 enhanced MM cell adhesion and proliferation. Intriguingly, ITGB3 overexpression upregulated the transcription factor Krüppel-like factor 2 (KLF2), which further enhanced EGFL7 transcription in MM cells, thereby establishing an EGFL7-ITGB3-KLF2-EGFL7 amplification loop that supports MM cell survival and proliferation. EGFL7 expression was found in certain plasma cells of patients with refractory MM and of patients at primary diagnosis. NOD.CB17-Prkdc/J mice transplanted with MM cells showed elevated human plasma EGFL7 levels. EGFL7 knockdown in patient-derived MM cells and treatment with neutralizing antibodies against EGFL7 inhibited MM cell growth in vitro and in vivo. We demonstrate that the standard-of-care MM drug bortezomib upregulates EGFL7, ITGB3, and KLF2 expression in MM cells. Inhibition of EGFL7 signaling in synergy with BTZ may provide a novel strategy for inhibiting MM cell proliferation.

Increased circulating levels of Epidermal Growth Factor-like Domain 7 in pregnant women affected by preeclampsia

Proper placental development is crucial to establish a successful pregnancy. Defective placentation is the major cause of several pregnancy complications, including preeclampsia (PE). We have previously demonstrated that the secreted factor Epidermal Growth Factor-like Domain 7 (EGFL7) is expressed in trophoblast cells of the human placenta and that it regulates trophoblast migration and invasion, suggesting a role in placental development. In the present study, we demonstrate that circulating levels of EGFL7 are undetectable in nonpregnant women, increase during pregnancy and decline toward term. Close to term, circulating levels of EGFL7 are significantly higher in patients affected by PE when compared to normal pregnancies. Consistent with these results, villus explant cultures obtained from placentas affected by PE display increased release of EGFL7 in the culture medium when compared to those from normal placentas. Our results suggest that increased release of placenta-derived EGFL7 and increased circulating levels of EGFL7 are associated with the clinical manifestation of PE.

Genetic Polymorphism of Epidermal Growth Factor rs4444903 Influences Susceptibility to HCV-Related Liver Cirrhosis and Hepatocellular Carcinoma in a Chinese Han Population

BACKGROUND

Genetic polymorphism in the epidermal growth factor (EGF, rs4444903) gene has been demonstrated to be associated with the clinical deterioration in hepatitis C virus (HCV)-related liver cirrhosis (LC) and the development of hepatocellular carcinoma (HCC). Whether this single nucleotide polymorphism (SNP) influences susceptibility to HCV-related LC and HCC in the Chinese Han population is largely unknown.

METHODS

In this case-control study, a total of 187 Chinese Han patients with chronic HCV infection were enrolled, including 62 HCV-related LC patients, 46 HCV-related HCC patients, and 79 chronic hepatitis C (CHC) patients without LC and HCC, and the genetic polymorphism was genotyped via a matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) assay. The logistical regression analysis was employed to determine the correlation between the genetic polymorphism and risk of HCV-related LC and HCC.

RESULTS

The distribution of EGF rs4444903 genotypes and alleles significantly differed between LC patients and CHC subjects (p = 0.045, p = 0.043, respectively). Under the recessive model, the GG genotype was significantly associated with a two-fold risk of HCV-related LC compared to the AA+AG genotype after an adjustment for age, gender, body mass index (BMI), duration of HCV infection, and HCV RNA level (OR = 2.188; 95% CI = 1.072 - 4.465; p = 0.031). Significant association was observed as well between the GG genotype and increased HCV-related HCC risk (OR = 3.104; 95% CI = 1.319 - 7.307; p = 0.010).

CONCLUSIONS

The EGF rs4444903 GG genotype is associated with higher susceptibility to HCV-related LC and HCC in the Chinese Han population. Screening of host genetic polymorphisms might be helpful in designing effective and efficient LC and HCC surveillance programs for chronic HCV-infected patients.

Randomized Phase II Trial of Parsatuzumab (Anti-EGFL7) or Placebo in Combination with FOLFOX and Bevacizumab for First-Line Metastatic Colorectal Cancer

Lessons Learned.

These negative phase II results for parsatuzumab highlight the challenges of developing an agent intended to enhance the efficacy of vascular endothelial growth factor inhibition without the benefit of validated pharmacodynamic biomarkers or strong predictive biomarker hypotheses.

Any further clinical development of anti‐EGFL7 is likely to require new mechanistic insights and biomarker development for antiangiogenic agents.

Background.

EGFL7 (epidermal growth factor‐like domain 7) is a tumor‐enriched vascular extracellular matrix protein that supports endothelial cell survival. This phase II trial evaluated the efficacy of parsatuzumab (also known as MEGF0444A), a humanized anti‐EGFL7 IgG₁ monoclonal antibody, in combination with modified FOLFOX6 (mFOLFOX6) (folinic acid, 5‐fluorouracil, and oxaliplatin) bevacizumab in patients with previously untreated metastatic colorectal cancer (mCRC).

Methods.

One‐hundred twenty‐seven patients were randomly assigned to parsatuzumab, 400 mg, or placebo, in combination with mFOLFOX6 plus bevacizumab, 5 mg/kg. Treatment cycles were repeated every 2 weeks until disease progression or unacceptable toxicity for a maximum of 24 months, with the exception of oxaliplatin, which was administered for up to 8 cycles.

Results.

The progression‐free survival (PFS) hazard ratio was 1.17 (95% confidence interval [CI], 0.71–1.93; p = .548). The median PFS was 12 months for the experimental arm versus 11.9 months for the control arm. The hazard ratio for overall survival was 0.97 (95% CI, 0.46–2.1; p = .943). The overall response rate was 59% in the parsatuzumab arm and 64% in the placebo arm. The adverse event profile was similar in both arms.

Conclusions.

There was no evidence of efficacy for the addition of parsatuzumab to the combination of bevacizumab and chemotherapy for first‐line mCRC.

EGFL7 is an intercellular EGFR signal messenger that plays an oncogenic role in glioma

Epidermal Growth Factor like domain 7 (EGFL7), also known as Vascular Endothelial-statin (VE-statin), is a secreted angiogenic factor. Recent data have demonstrated the potential oncogenic role and prognostic significance of EGFL7 in several human cancers. However, the clinical signature and further mechanisms of EGFL7's function in gliomagenesis are poorly understood. In the present study, we found that increased EGFL7 expression was associated with tumor grade. High expression of EGFL7 in EGFRvIII-positive glioblastoma multiforme (GBM) was determined to be a strong and independent risk factor for reduced life expectancy. EGFRvIII cells can secrete the EGFL7 protein to improve the activity of the β-catenin/TCF4 Transcription complex in EGFRwt cells, thus promoting their own EGFL7 expression. Our research demonstrates that oncogenic activation of EGFRwt in GBM is likely maintained by a continuous EGFL7 autocrine flow line, and may be an attractive target for therapeutic intervention.

Restricted neural epidermal growth factor-like like 2 (NELL2) expression during muscle and neuronal differentiation

We have identified a secreted glycoprotein, neural epidermal growth factor-like like 2 (NELL2), in a screen designed to isolate molecules regulating sensory neuron genesis and differentiation in the dorsal root ganglia (DRG). In investigating NELL2 expression during embryogenesis, we demonstrate here that NELL2 is highly regulated spatially and temporally, being only transiently expressed in discrete regions of the central (CNS) and peripheral nervous systems (PNS) and in a subset of mesoderm derived structures during their peak periods of development. In the CNS and PNS, NELL2 is maximally expressed as motor and sensory neurons differentiate. Interestingly, its expression is restricted to sublineages of the neural crest, being strongly expressed throughout the immature DRG, but excluded from sympathetic ganglia. Similarly during muscle development, NELL2 is specifically expressed by hypaxial muscle precursor cells in the differentiating somite and derivatives in the forelimbs and body wall, but not by epaxial muscle precursors. Furthermore, NELL2 is differentially regulated in the CNS and PNS; in the CNS, NELL2 is only expressed by nascent, post-mitotic neurons as they commence their differentiation, yet in the PNS, NELL2 is expressed by subsets of progenitor cells in addition to nascent neurons. Based on this restricted spatial and temporal expression pattern, functional studies are in progress to determine NELL2's role during neuronal differentiation in both the PNS and CNS.

Epidermal growth factor-like domain 7 promotes cell invasion and angiogenesis in pancreatic carcinoma

Epidermal growth factor-like domain 7 (EGFL7), also known as vascular endothelial stain, was firstly identified as a modulator of smooth muscle cell migration. Though the expression of EGFL7 was reported to be up-regulated during tumorigenesis, the clinical and biological functions of EGFL7 in pancreatic carcinoma (PC) were still not fully elucidated. In this study, we found that the serum EGFL7 level in PC tissues was statistically higher than that in normal subjects (p<0.001), and its level in non-resectable patients was also higher than that in resectable ones (p=0.013). Among these resectable PC patients, the postoperative EGFL7 expression was significantly down-regulated when tumors were resected (p=0.018). Using the immunohistochemistry method, our results demonstrated that the positive expression of EGFL7 was significantly associated with the TNM stage (p=0.024), lymph node metastasis (p=0.003) and local invasion (p=0.022), and the EGFL7 expression closely correlated to the micro-vessel density (MVD) in PC tissues by Spearman analysis (r=0.941, p=0.000). In vitro, EGFL7 was silenced by the small interference RNA in PC cells, and our data indicated that down-regulation of EGFL7 did not influence the cycle progression, proliferation, colony formation and apoptosis of PC cells (p>0.05), whereas inhibition of EGFL7 expression could decrease PaCa-2 cell invasion (p<0.05). More interestingly, by tubular formation, Chick embryo chorioallantoic membrane (CAM) and ELISA assays, our results revealed that silencing EGFL7 expression represented a strong inhibiting effect on tubular formation of micro-vessels through down-regulating the protein levels of VEGF and Ang-2 (p<0.05). Our results raised the possibility of using EGFL7as a potential prognostic biomarker and therapy target of PC, and down-regulation of EGFL7 might be considered to be a potentially important molecular treatment strategy for patients with PC.

Methylation-associated Silencing of microRNA-126 and its Host Gene EGFL7 in Malignant Pleural Mesothelioma

BACKGROUND/AIM

We recently reported that miR-126 is down-regulated in malignant pleural mesothelioma (MPM) and can be combined into a 4-microRNA-classifier that can accurately diagnose MPM with high sensitivity and specificity. Herein we analyzed the epigenetic regulation of miR-126 and its host gene EGF-like domain, multiple 7 (EGFL7).

MATERIALS AND METHODS

Resected formalin-fixed paraffin-embedded MPM tissues from 29 patients, 14 patient-matched non-neoplastic pleura (NNP) specimens, 5 MPM diagnostic biopsies (DB), and 5 samples of pneumothorax-induced benign reactive mesothelial proliferation (PTHX) were analyzed. miR-126 and EGFL7 mRNA were quantified by RT-qPCR. CpG-islands' methylation in the EGFL7 promoter was analyzed using methylation-specific PCR and in the MIR126-containing intron 7 was quantified by pyrosequencing.

RESULTS

Relative to NNP, EGFL7 was under-expressed more than 4-fold in MPM (p<0.001). EGFL7 mRNA and miR-126 levels correlated in MPM (p<0.01) and NNP (p<0.001). The EGFL7 promoter region was hypermethylated in 69% of MPM and 80% of DB samples, but not in NNP and PTHX samples. EGFL7 promoter hypermethylation was associated with epithelioid histology (p<0.05) and reduced patient-survival (p<0.05).

CONCLUSION

In MPM, DNA-hypermethylation down-regulates miR-126 and its host gene EGFL7, therefore is a poor prognostic factor, and may represent a future therapeutic target for de-methylating strategies re-establishing EGFL7 and miR-126 expression.

In-vitro inhibitory effect of EGFL7-RNAi on endothelial angiogenesis in glioma

OBJECTIVE

To investigate the role and mechanism of epidermal growth factor like domain 7 (EGFL7) in glioma angiogenesis by cell co-culture and RNA interference.

METHODS

NSCs-HUVECs co-culture system was established using Transwell culturing techniques. The interactions between glioma and endothelial cells were simulated in-vitro. Cellular expression of EGFL7 in NSCs and HUVEC was targeted and suppressed by lentiviral vector carrying siRNA. The effect of EGFL7 on angiogenesis in glioma in-vitro micro-environment was detected by endothelial cell proliferation, adhesion and tube formation assay.

RESULTS

Following EGFL7 gene silencing, expression of EGFL7 in HUVECs was reduced and cell adhesion capability was inhibited significantly. Endothelial cells failed to form a lumen-like structure after EGFL7 gene silencing, shown by the tube formation assay.

CONCLUSION

By regulating endothelial cell adhesion, EGFL7 plays a key role in the regulation of glioma angiogenesis.

[Epidermal growth factor-like domain 7 promotes endothelial cell migration and angiogenesis by activating ERK signaling pathway]

OBJECTIVE

To explore the effect of epidermal growth factor-like domain 7(EGFL7) on the migration and angiogenesis of endothelial cells.

METHODS

EGFL7 overexpression vectors were constructed and transfected into human microvascular endothelial cells. The expression levels of EGFL7-mRNA and EGFL7 protein were examined by real-time RT-PCR and Western blot. Cell migration was analyzed by the wound healing. The capability of cell to form capillary-like tubes in vitro was evaluated on matrigel assay. Protein expression of p-AKT, AKT, p-ERK and ERK in endothelial cells was detected by Western blot upon transfection with EGFL7 overexpression vectors and vehicle control for 0, 10, 30 and 60 min.

RESULTS

Migration and angiogenesis of endothelial cells were notably enhanced by EGFL7 overexpression. ERK pathway was strongly activated by EGFL7, whereas AKT remained constant in endothelial cells. Inhibition of ERK impaired EGFL7 induced ERK activation and endothelial cell migration and angiogenesis.

CONCLUSION

EGFL7 effectively promotes migration and angiogenesis through ERK signaling pathway in endothelial cells.

[Study on the correlation of epidermal growth factor and Sjoigren's syndrome with atrophic glossitis]

PURPOSE

To investigate the correlation between epidermal growth factor (EFG) and atrophic glossitis (AG) in patients with Sjoigren's syndromes (SS) and explore its pathogenesis.

METHODS

Ninety-three patients with SS (60 with AG and 33 without AG) and 20 normal were selected. The concentrations of EGF in saliva were analyzed by ELISA. The expressions of EGF receptor (EGFR) in the epithelial cells of the tongue were assayed by immunohistochemistry. The differences among each group were analyzed with SPSS19.0 software package.

RESULTS

The saliva EGF concentrations in SS was lower than that in normal control group(P<0.0001),and EGF concentrations in SS with AG was significantly lower than that in SS without AG (P=0.024). EGF levels in saliva gradually decreased in the mild, moderate and severe atrophic glossitis groups, and there were significant differences among each group(P<0.05). EGFR in the epithelial cells of tongue was lower in SS with moderate and severe AG than in the control group(P=0.009, P=0.037), and there was a significant correlation between EGF and the degree of AG (r=-0.673, P<0.01).

CONCLUSIONS

Saliva EGF concentrations decrease significantly in patients with SS and it is closely related to the morbidity of atrophic glossitis.

[Expression of serum and urinary vascular endothelial growth factor-A and epidermal growth factor-like domain 7 in proliferating hemangioma treated with propranolol]

OBJECTIVE

This study aims to investigate the expression levels of serum and urinary vascular endothelial growth factor-A (VEGF-A) and epidermal growth factor-like domain 7 (EGFL7) in proliferating infantile hemangioma patients under propranolol treatment.

METHODS

Propranolol (0.5-2 mg x kg(-1)) was orally administered to 30 infants every day for 4-8 months. The Achauer method was used to measure the tumor radius and thus evaluate the clinical curative effects of the treatment. Enzyme-linked immunosorbent assay was used to measure the serum and urinary concentrations of VEGF-A and EGFL7 at 0, 4, and 12 weeks after the treatment.

RESULTS

The treatment response was excellent in 2 patients, good in 11, moderate in 14, and poor in 3. Serum VEGF-A (335.692 pg x mL(-1) ± 136.146 pg x mL(-1)) was high before the treatment and then significantly decreased after 4 weeks (264.853 pg x mL(-1) ± 122.120 pg x mL(-1)) and 12 weeks (211.345 pg x mL(-1) ± 104.035 pg x mL(-1)) of treatment (P < 0.05). Urinary VEGF-A (76.234 pg x mL(-1) ± 24.169 pg x mL(-1)) was high before the treatment and then significantly decreased after four weeks (56.454 pg x mL(-1) ± l6.111 pg x mL(-1)) and twelve weeks (34.728 pg x mL(-1)) ± 12.656 pg x mL(-1)) of treatment (P < 0.05). Serum and urinary EGFL7 also decreased after the treatment, showing a positive relationship with VEGF-A.

CONCLUSION

Propranolol can be safely and effectively used to treat proliferating infantile hemangiomas. This treatment can reduce the peripheral serum and urinary concentrations of VEGF-A and EGFL7 in affected children.

Androgen actions in the ovary: balance is key

For many decades, elevated androgens in women have been associated with poor reproductive health. However, recent studies have shown that androgens play a crucial role in women's fertility. The following review provides an overall perspective about how androgens and androgen receptor-mediated actions regulate normal follicular development, as well as discuss emerging concepts, latest perceptions, and controversies regarding androgen actions and signaling in the ovary.

[Efficacy of photodynamic antimicrobial therapy for wound flora and wound healing of pressure sore with pathogen infection]

OBJECTIVE

To explore the efficacy of photodynamic antimicrobial therapy in the treatment of pressure sore with pathogen infection.

METHODS

A total of 42 pressure sore patients with pathogen infection were divided randomly into experimental and control groups (n = 21 each). Fufanghuangbai liquid was used for external application with control group. In the experimental group, wound was treated with Fufanghuangbai liquid wet dressing and irradiated by semiconductor laser 30 min late. The distance from semiconductor laser probe to wound site was 10-15 cm, 20 min twice daily, continuous exposure to 7 days for 1 course. The results of bacterial culture and epidermal growth factor (EGF) expression of wound granulation tissue were observed before and after treatment. And the changes of healing rate of pressure sore were measured at post-treatment in each group.

RESULTS

The positive rates of bacterial culture, rates of change around wound inflammation, healing rate of days 7 and 14, the high expression of EGF on healing wound granulation tissue was 9.75%, (32.2% ± 5.8%), (89.1% ± 5.6%), (12.4% ± 2.9%), (34.7% ± 3.6%), 14/21 in the treatment group versus 51.2%, (17.8% ± 2.0%), (57.3% ± 2.6%), (5.1% ± 1.1%), (10.5% ± 2.4%), 2/21 in the control group respectively. The inter-group differences were statistically significant (P < 0.05).

CONCLUSION

Photodynamic antimicrobial therapy is an effective method for pressure sore with pathogen infection. Wound healing is promoted through an up-regulation of EGF.

[Effects of lentivirus-mediated epidermal growth factor-like domain 7 silencing on proliferation and invasion of human laryngeal carcinoma Hep-2 cells]

OBJECTIVE

To explore the effects of epidermal growth factor-like domain 7 (EGFL7) gene silencing on the proliferation and invasion ablity of laryngeal carcinoma cells.

METHODS

A lentiviral vector expressing EGFL7 shRNA was constructed and transfected into human laryngeal carcinoma Hep-2 cells. The expressions of EGFL7 mRNA and protein were detected by Real-time PCR and Western blot, respectively. Cell proliferation was evaluated by CCK-8 assay, cell cycle and apoptosis were tested by flow cytometry, and cell invasion was detected by transwell invasion assay.

RESULTS

The relative expression level s of EGFL7 mRNA and protein in EGFL7-SuRNA group were svgnificantly lower than control group (P < 0.001). Western blot analysis proved that the relative expression of EGFL7 protein in NC group, Lenti-NC group and Lenti-EGFL7 group was (0.39 ± 0.12),(0.36 ± 0.14) and (0.07 ± 0.04), respectively. EGFL7 expression in Lenri-EGFL7 group was significantly inhibited than NC group (P < 0.001), which confirmed that the recombinant lentivirus was successfully transfected into Hep-2 cells. The proliferation of Hep-2 cells was significantly inhibited after transfection (P < 0.01). Compared with the NC group and Lenti-NC group, the proportion of cells in S phase was significantly increased in Lenti-EGFL7 group (P < 0.01), and the proportion in G1 phase was significantly decreased (P < 0.05). Cell apoptosis assay showed that the apoptotic rate in Lenti-EGFL7 group (66.2 ± 1.28) % was significantly increased in NC group (6.09 ± 3.28) % and Lenti-NC group (9.86 ± 2.13) %. In Transwell invision assay, the mean number of cells coming through the Metrigel in Lenti-EGFL7 group was significantly decreased than in the NC group and Lenti-NC group (P < 0.01).

CONCLUSION

The proliferation and invasion ablity of laryngeal carcinoma Hep-2 cells can be inhibited by siRNA mediated EGFL7 gene silencing.

TGF-β1 induces COX-2 expression and PGE2 production in human granulosa cells through Smad signaling pathways

CONTEXT

Cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production have been shown to play key roles in the regulation of ovulation. The TGF-β superfamily members are important molecules that regulate many ovarian functions under normal physiological and pathological conditions. TGF-β1 and its receptors are expressed in human granulosa cells. However, to date, whether TGF-β1 can regulate COX-2 expression and PGE2 production, which in turn contribute to the process of ovulation, remains unknown.

OBJECTIVE

The objective of the study was to investigate the effects of TGF-β1 on COX-2 expression and PGE2 production in human granulosa cells.

DESIGN

SVOG cells are human granulosa cells that were obtained from women undergoing in vitro fertilization and immortalized with Simian virus 40 large T antigen. SVOG cells were used to investigate the effect of TGF-β1 on COX-2 expression and PGE2 production.

SETTING

The study was conducted at an academic research center.

MAIN OUTCOME MEASURES

mRNA and protein levels were examined by RT-quantitative real-time PCR and Western blotting, respectively. The concentrations of PGE2 in the culture medium were measured by an ELISA.

RESULTS

TGF-β1 treatment induced COX-2 expression and PGE2 production. The inductive effects of TGF-β1 on COX-2 and PGE2 were abolished by the inhibition of TGF-β type I receptor (TβRI). In addition, treatment with TGF-β1 activated phosphorylated mothers against decapentaplegic (Smad)-2 and Smad3 signaling pathways. Inhibition of the Smad signaling pathways by small interfering RNA-mediated approaches attenuated the TGF-β1-induced COX-2 expression and PGE2 production.

CONCLUSION

TGF-β1 induced PGE2 production by inducing the COX-2 expression through a Smad-dependent signaling pathway in human granulosa cells.

[Expression and significance of heparin binding-epidermal growth factor-like growth factor in paclitaxel-resistant ovarian cancer]

OBJECTIVE

To examine the expression of heparin binding-epidermal growth factor-like growth factor (HB- EGF) in paclitaxel- resistant ovarian cancer and elucidate the relationship between HB-EGF and the resistance of ovarian cancer to paclitaxel.

METHODS

The human ovarian carcinoma cell line A2780 and the paclitaxel- resistant human ovarian carcinoma cell line A2780/Taxol were cultured in vitro. Western blot was used to dectect the expression of HB-EGF protein in A2780 and A2780/Taxol groups. The A2780 cells were treated with cross- reacting material 197 (CRM197 and A2780 + CRM197 group) or dimethyl sulphoxide (DMSO; A2780 group), while the A2780/Taxol cells were treated with CRM197 (A2780/Taxol+CRM197 group) or DMSO (A2780/Taxol group). The effects of CRM197 on growth and proliferation was tested by methyl thiazolyl tetrazolium ( MTT) and the results were showed as absorbance (A). The effects of CRM197 on cell cycles was tested by flow cytometry, while the effects of CRM197 on apoptosis was examined by caspase- 3 activity assay and the results were showed as p- nitroaniline(pNa). In animal experiment, four groups of cells were inoculated to BALB/c nude mouse subcutaneously to observe tumor formation ability following CRM197 treatment. Immunohistochemistry was used to determine the expression of HB-EGF protein in A2780 and A2780/Taxol group.

RESULTS

The expression level of HB-EGF protein in A2780/Taxol group (2.11 ± 0.41) was significantly higher than that of A2780 group (0.75 ± 0.20; P < 0.01). The inhibition effect of CRM197 on the cell growth of A2780+CRM197 and A2780/Taxol+CRM197 group was accompanied by the acceleration of CRM197 concentration(P < 0.01). When CRM197≥1 µg/ml, the inhibition effect of CRM197 on the cell growth of A2780/Taxol+CRM197 group was significantly higher than that in A2780/Taxol group(P < 0.05). In cell cycle experiment, CRM197 induced the cell-cycle arrest at the G0/G1 phase in A2780+CRM197 cells[(67 ± 4)%] compared with A2780 cells[(54 ± 6)%; P < 0.01], while CRM197 significantly induced the cell-cycle arrest at the G0/G1 phase in A2780/Taxol+CRM197 cells [(72 ± 4)%] compared with A2780/Taxol cells [(24 ± 8)%; P < 0.01]. CRM197 treatment in A2780+CRM197 group [(40 ± 6) µmol/L] led to the acceleration of the caspase-3 activity when compared to A2780 group [(6 ± 6) µmol/L; P < 0.01], while CRM197 treatment in A2780/Taxol+CRM197 group [(66 ± 12) µmol/L] led to significant acceleration of the caspase-3 activity when compared to A2780 group [(9 ± 6) µmol/L; P < 0.01]. In experiments in vivo, the expression scores of HB- EGF protein in A2780/Taxol tumors (10.8 ± 3.3) were higher than that in A2780 tumors (5.0 ± 2.2; P < 0.01). The tumor size and tumor weight of the A2780/Taxol + CRM197 group were both higher than those of the A2780+CRM197 group [(546 ± 85) mm³ vs (1 355 ± 119) mm³, (0.56 ± 0.09)g vs(1.31 ± 0.27)g; all P < 0.01]. The CRM197 inhibition rate of the A2780+ CRM197 and A2780/Taxol + CRM197 group were 43% and 68% respectively, showed that CRM197 significantly suppressed the growth of A2780/Taxol xenografts in vivo(P < 0.01).

CONCLUSIONS

HB-EGF is over-expressed in paclitaxel-resistant ovarian cancer and may be contributes to drug resistance. Inhibition of HB- EGF expression potently enhances apoptosis and inhibit the growth of paclitaxel- resistant ovarian cancer, shedding light on the HB-EGF-targeted therapy options for chemoresistant ovarian cancer patients.

EGF-like-domain-7 is required for VEGF-induced Akt/ERK activation and vascular tube formation in an ex vivo angiogenesis assay

EGFL7 is a secreted angiogenic factor, which in contrast to the well-known secreted angiogenic molecules VEGF and FGF-2, is almost exclusively expressed by endothelial cells and may act in an autocrine fashion. Prior studies have shown EGFL7 to mediate its angiogenic effects by interfering with the Notch pathway and/or via the intronic miR126. Less is known about its effects on VEGF signaling. We wanted to investigate the role of epidermal growth factor-like domain 7 (EGFL7) in VEGF-driven angiogenesis using an ex vivo Matrigel-embedded mouse eye cup assay and siRNA mediated knockdown of EGFL7 by siRNA. Our results suggested that VEGF-induced vascular tube formation was significantly impaired after siRNA downregulation of EGFL7. In addition, knockdown of EGFL7 suppressed VEGF upregulation of phospho-Akt and phospho-Erk(1/2) in endothelial cells, but did not alter VEGFR phosphorylation and neuropilin-1 protein expression or miR126 expression. Thus, in conclusion, EGFL7 is required for VEGF upregulation of the Akt/Erk (1/2) pathway during angiogenesis, and may represent a new therapeutic target in diseases of pathological neovascularization.

Egfl7 is differentially expressed in arteries and veins during retinal vascular development

The vasculature of the central nervous system (CNS) is composed of vascular endothelial and mural cells which interact closely with glial cells and neurons. The development of the CNS vascularisation is a unique process which requires the contribution of specific regulators in addition to the classical angiogenic factors. The egfl7 gene is mainly detected in endothelial cells during physiological and pathological angiogenesis. Egfl7 codes for a secreted protein which predominantly accumulates into the extracellular space where it controls vascular elastin deposition or the Notch pathway. Egfl7 is the host gene of the microRNA miR126 which is also expressed in endothelial cells and which plays major functions during blood vessel development. While the expression of egfl7 and that of miR126 were well described in endothelial cells during development, their pattern of expression during the establishment of the CNS vasculature is still unknown. By analysing the expression of egfl7 and miR126 during mouse retina vascularisation, we observed that while expression of miR126 is detected in all endothelia, egfl7 is initially expressed in all endothelial cells and then is progressively restricted to veins and to their neighbouring capillaries. The recruitment of mural cells around retina arteries coincides with the down-regulation of egfl7 in the arterial endothelial cells, suggesting that this recruitment could be involved in the loss of egfl7 expression in arteries. However, the expression pattern of egfl7 is similar when mural cell recruitment is prevented by the injection of a PDGFRβ blocking antibody, suggesting that vessel maturation is not responsible for egfl7 down-regulation in retinal arteries.

VE-statin/Egfl7 expression in malignant glioma and its relevant molecular network

This study investigated VE-statin/Egfl7 expression and its role and regulatory mechanism in malignant glioma progression. Forty-five paraffin-embedded glioma (grade I-II: n=24; grade III-IV: n=21) were examined. VE-statin/Egfl7 protein expression was detected via immunohistochemistry, and its correlation with pathological grade was evaluated. Three-dimensional cell culture was then performed to investigate the influence of VE-statin/Egfl7 on the angiogenesis of umbilical vein endothelial cells. Microarray detection was used to molecularly profile VE-statin/Egfl7 and relevant signaling pathways in malignant glioma (U251 cells). Data showed that VE-statin/Egfl7 protein was mainly expressed in the cytoplasm of cancer and vascular endothelial cells and was significantly related to the degree of malignancy (t=4.399, P<0.01). Additionally, VE-statin/Egfl7 expression was low in certain gray-matter neurons but undetectable in glial cells. VE-statin/Egfl7 gene silencing significantly inhibited angiogenesis in umbilical vein endothelial cells. The following microarray results were observed in VE-statin/Egfl7-silenced U251 cells: 1) EGFR family members showed the highest differential expression, accounting for 5.54% of differentially expressed genes; 2) cell survival-related signaling pathways changed significantly; and 3) the integrin ανβ3 signaling pathway was markedly altered. Thus, malignant glioma cells and glioma vascular endothelial cells highly express VE-statin/Egfl7, which is significantly correlated with the degree of malignancy. Moreover, VE-statin/Egfl7 plays an important role in glioma angiogenesis. Microarray results indicate that VE-statin/Egfl7 may regulate EGFR and integrins to influence the FAK activity of downstream factors, triggering the PI3K/Akt and Ras/MAPK cascades and subsequent malignant glioma development.

VE-statin/Egfl7 siRNA inhibits angiogenesis in malignant glioma in vitro

This study investigated the role of VE-statin/Egfl7 and its mechanism in angiogenesis in malignant glioma. Transwell culture plates were used to establish an U251-HUVEC co-culture system, which was used to mimic the interaction between malignant glioma and endothelial cells. Lentiviral vectors expressing VE-statin/Egfl7 siRNA were constructed, and U251 cells and HUVECs were transfected to inhibit VE-statin/Egfl7 expression. The proliferation, adherence, migration, and lumen formation of endothelial cells were assayed to investigate the influence of VE-statin/Egfl7 on angiogenesis in malignant glioma in vitro. Data showed that HUVEC growth was temporarily slowed after silencing the VE-statin/Egfl7 gene but rapidly returned to normal. Although endothelial cell migration was not influenced, cell adherence was markedly inhibited. Furthermore, the endothelial cells failed to generate a capillary-like lumen after VE-statin/Egfl7 gene silencing. Therefore, it can be concluded that VE-statin/Egfl7 may regulate the adherence of endothelial cells, thus playing an important role in endothelium-induced lumen formation during angiogenesis in malignant glioma.

Expression of the epidermal growth factor system in human middle ear cholesteatoma

CONCLUSION

The detection of the HER4 receptor in 50% of cholesteatomas but never in the reference tissue, and the increased expression of its activating ligand EPI, suggest that EPI-mediated activation of HER4 might play a role in cholesteatoma growth.

OBJECTIVE

To investigate the expression of the epidermal growth factor (EGF) system in human middle ear cholesteatoma.

METHODS

Forty-seven patients referred for surgery due to cholesteatoma were included in the study. Clinical data were collected. Biopsies of cholesteatoma and skin from the external ear canal were obtained during surgery. mRNA expression was quantified with real-time PCR. The corresponding proteins were visualized using immunohistochemistry.

RESULTS

A systematic investigation of all four receptors, HER1, HER2, HER3, and HER4, and the ligands EGF, transforming growth factor (TGF)-α, amphiregulin (AR), heparin-binding EGF-like growth factor (HB-EGF), and epiregulin (EPI) of the EGF system is presented. At the mRNA level, the study demonstrates an up-regulation of mRNA encoding EPI and AR. In contrast HER1 and EGF were down-regulated. HER4 mRNA could be detected in 50% of cholesteatoma and 20% of reference tissues, and the HER4 protein was detectable only in cholesteatoma tissue. HER1 and HER2 were also visualized by immunohistochemistry, whereas the ligands EPI, AR, and EGF were undetectable with our methods.

EGF-like growth factors induce COX-2-derived PGE2 production through ERK1/2 in human granulosa cells

CONTEXT

Aberrant regulation of ovulation is one of the major causes of infertility. In animal models, 3 epidermal growth factor (EGF)-like growth factors, amphiregulin (AREG), betacellulin (BTC), and epiregulin (EREG), have been shown to be involved in ovulation by regulating cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production. However, whether the same is true in humans remains largely unknown.

OBJECTIVE

Our objective was to investigate the effects of AREG, BTC, and EREG on COX-2 expression and PGE2 production in human granulosa cells.

DESIGN AND SETTING

SVOG cells are human granulosa cells that were obtained from women undergoing in vitro fertilization and immortalized with SV40 large T antigen. SVOG cells were used to investigate the effect of AREG, BTC, and EREG on ovulation-related functions at an academic research center.

MAIN OUTCOME MEASURES

Levels of mRNA and protein were examined by quantitative RT-PCR and Western blotting, respectively. The protein levels of PGE2 were measured by ELISA.

RESULTS

LH treatment upregulated AREG, BTC, EREG, and COX-2. Knockdown of EGF receptor (EGFR) attenuated LH-induced COX-2 expression and PGE2 production. Treatment with AREG, BTC, and EREG upregulated COX-2 expression and PGE2 production. The stimulatory effects of AREG, BTC, and EREG on COX-2 expression and PGE2 production were blocked by inhibition of EGFR activity and expression. AREG-, BTC-, and EREG-activated ERK1/2 signaling, but not Akt signaling, was required for AREG-, BTC-, and EREG-induced COX-2 expression and PGE2 production.

CONCLUSION

AREG, BTC, and EREG induced PGE2 production by upregulating COX-2 expression through ERK1/2 signaling in human granulosa cells.

Distinct effects of EGFR ligands on human mammary epithelial cell differentiation

Based on gene expression patterns, breast cancers can be divided into subtypes that closely resemble various developmental stages of normal mammary epithelial cells (MECs). Thus, understanding molecular mechanisms of MEC development is expected to provide critical insights into initiation and progression of breast cancer. Epidermal growth factor receptor (EGFR) and its ligands play essential roles in normal and pathological mammary gland. Signals through EGFR is required for normal mammary gland development. Ligands for EGFR are over-expressed in a significant proportion of breast cancers, and elevated expression of EGFR is associated with poorer clinical outcome. In the present study, we examined the effect of signals through EGFR on MEC differentiation using the human telomerase reverse transcriptase (hTERT)-immortalized human stem/progenitor MECs which express cytokeratin 5 but lack cytokeratin 19 (K5⁺K19^- hMECs). As reported previously, these cells can be induced to differentiate into luminal and myoepithelial cells under appropriate culture conditions. K5⁺K19^- hMECs acquired distinct cell fates in response to EGFR ligands epidermal growth factor (EGF), amphiregulin (AREG) and transforming growth factor alpha (TGFα) in differentiation-promoting MEGM medium. Specifically, presence of EGF during in vitro differentiation supported development into both luminal and myoepithelial lineages, whereas cells differentiated only towards luminal lineage when EGF was replaced with AREG. In contrast, substitution with TGFα led to differentiation only into myoepithelial lineage. Chemical inhibition of the MEK-Erk pathway, but not the phosphatidylinositol 3-kinase (PI3K)-AKT pathway, interfered with K5⁺K19^- hMEC differentiation. The present data validate the utility of the K5⁺K19^- hMEC cells for modeling key features of human MEC differentiation. This system should be useful in studying molecular/biochemical mechanisms of human MEC differentiation.

System-wide analysis reveals a complex network of tumor-fibroblast interactions involved in tumorigenicity

Many fibroblast-secreted proteins promote tumorigenicity, and several factors secreted by cancer cells have in turn been proposed to induce these proteins. It is not clear whether there are single dominant pathways underlying these interactions or whether they involve multiple pathways acting in parallel. Here, we identified 42 fibroblast-secreted factors induced by breast cancer cells using comparative genomic analysis. To determine what fraction was active in promoting tumorigenicity, we chose five representative fibroblast-secreted factors for in vivo analysis. We found that the majority (three out of five) played equally major roles in promoting tumorigenicity, and intriguingly, each one had distinct effects on the tumor microenvironment. Specifically, fibroblast-secreted amphiregulin promoted breast cancer cell survival, whereas the chemokine CCL7 stimulated tumor cell proliferation while CCL2 promoted innate immune cell infiltration and angiogenesis. The other two factors tested had minor (CCL8) or minimally (STC1) significant effects on the ability of fibroblasts to promote tumor growth. The importance of parallel interactions between fibroblasts and cancer cells was tested by simultaneously targeting fibroblast-secreted amphiregulin and the CCL7 receptor on cancer cells, and this was significantly more efficacious than blocking either pathway alone. We further explored the concept of parallel interactions by testing the extent to which induction of critical fibroblast-secreted proteins could be achieved by single, previously identified, factors produced by breast cancer cells. We found that although single factors could induce a subset of genes, even combinations of factors failed to induce the full repertoire of functionally important fibroblast-secreted proteins. Together, these results delineate a complex network of tumor-fibroblast interactions that act in parallel to promote tumorigenicity and suggest that effective anti-stromal therapeutic strategies will need to be multi-targeted.

Expression and functional activity of PACAP and its receptors on cumulus cells: effects on oocyte maturation

Pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptor PAC1-R (PACAP type 1 receptor) are transiently expressed in granulosa cells (GCs) of mouse preovulatory follicles and affect several parameters associated with the ovulatory process. We investigated the expression of PACAP and its receptors in cumulus cells (CCs) after the LH surge and their role on cumulus expansion/apoptosis and oocyte maturation. PACAP and PAC1-R expression increased in CCs isolated at different times after treatment with human chorionic gonadotropin (hCG). Moreover, PACAP was able to reverse the inhibition of oocyte meiotic maturation caused by hypoxantine in cumulus cell-oocyte complexes (COCs) and efficiently promoted male pronuclear formation after fertilisation. PACAP was also able to induce cumulus expansion and prevent CC apoptosis. Our results demonstrated the induction of PACAP and its receptors in CCs by LH and EGF, suggesting that PACAP may play a significant role in the complex interactions of gonadotropin and growth factors during ovulation and fertilisation.

Exosome-bound WD repeat protein Monad inhibits breast cancer cell invasion by degrading amphiregulin mRNA

Increased stabilization of mRNA coding for key cancer genes can contribute to invasiveness. This is achieved by down-regulation of exosome cofactors, which bind to 3'-UTR in cancer-related genes. Here, we identified amphiregulin, an EGFR ligand, as a target of WD repeat protein Monad, a component of R2TP/prefoldin-like complex, in MDA-MB-231 breast cancer cells. Monad specifically interacted with both the 3'-UTR of amphiregulin mRNA and the RNA degrading exosome, and enhanced decay of amphiregulin transcripts. Knockdown of Monad increased invasion and this effect was abolished with anti-amphiregulin neutralizing antibody. These results suggest that Monad could prevent amphiregulin-mediated invasion by degrading amphiregulin mRNA.

[Correlation between the presence of Kras mutation and the presence of the proteins epiregulin and amphiregulin in colon cancer tissue]

INTRODUCTION

Progress has been made in the treatment of metastatic colorectal cancer with the development of biologic agents such as Cetuximab and Panitumumab. These monoclonal antibodies are directed against EGFR and influence cell division, attachment, angiogenesis, migration and apoptosis. Correlation has been found between the presence of mutations in the K-ras gene and resistance to treatment with Cetuximab.New guidelines require K-ras mutation analysis before anti-EGFR treatment is provided. The proteins Amphiregulin and Epiregulin belong to the Epidermal growth factors family (EGF, that act through the EGFR. Over-expression of these proteins has been seen in a variety of malignancies and non-malignant pathologies. These proteins can be detected in samples from colorectal malignancies and inflammatory bowel disease by immunohistochemical staining. Jacobs et at showed that mRNA expression of these proteins n colorectal malignancy predicts outcomes in wild type K-ras metastatic patients treated with Cetuximab.

AIM

The purpose of our study is to examine whether there is a correlation between the presence of colorectal cancer K-ras mutations and the level of expression of EpireguLin and Amphiregulin in the malignant tissue.

MATERIAL AND METHODS

In a retrospective study we examined 30 tissue samples of colon cancer patients for the presence of K-ras mutation and immunohistochemicaL staining for Epiregulin and AmphireguLin.

RESULTS

A total of 14 (46.66%] samples showed mutation in the K-ras gene; 15 of 30 samples [50%] were positive for AmphireguLin. As for Epiregulin, 10 (33.3%) samples had strong staining, 10 (33.3%) samples had Light staining and the rest, 10 (33.3%) didn't have any staining. In conclusion, we did not find a correlation between the presence of a K-ras mutation and the presence of Epiregulin and Amphiregulin in colon cancer tissue.

Androgen/androgen receptor pathway regulates expression of the genes for cyclooxygenase-2 and amphiregulin in periovulatory granulosa cells

It is well known that the androgen/androgen receptor (AR) pathway is involved in both male and female fertility in mammals. AR knockout female mice are reported to exhibit various abnormalities in follicle development, and a subfertile phenotype. In exogenous gonadotropin-induced superovulation, serum androgen levels were robustly elevated in female mice at the periovulatory stage after human chorionic gonadotropin (hCG) treatment. At this stage, ovarian AR proteins were strongly expressed in cumulus cells. Because these results suggested that the androgen/AR pathway is involved in ovulation, we investigated the expression of ovulation-related genes in the mouse ovary treated with the nonaromatizable androgen, 5α-dihydrotestosterone (DHT). DHT treatment induced the expression of the genes for cyclooxyganase-2 (Cox-2 or prostaglandin endoperoxidase synthase 2) and the epidermal growth factor-like factor, amphiregulin (Areg), in the ovary, whereas their hCG-induced expression was suppressed by the AR antagonist flutamide. These genes were also induced by DHT in AR-expressing primary granulosa and granulosa tumor-derived cells. Reporter assays, electrophoretic shift mobility assays and chromatin immunoprecipitation assays demonstrated that androgen response sequence(s) existing upstream of each gene were responsible for androgen responsiveness and were occupied by the AR in periovulatory granulosa cells. Our results suggest that the androgen/AR pathway is involved in the ovulatory process via expression of the Cox-2 and Areg genes in periovulatory granulosa cells.

Promoter methylation of AREG, HOXA11, hMLH1, NDRG2, NPTX2 and Tes genes in glioblastoma

Epigenetic alterations alone or in combination with genetic mechanisms play a key role in brain tumorigenesis. Glioblastoma is one of the most common, lethal and poor clinical outcome primary brain tumors with extraordinarily miscellaneous epigenetic alterations profile. The aim of this study was to investigate new potential prognostic epigenetic markers such as AREG, HOXA11, hMLH1, NDRG2, NTPX2 and Tes genes promoter methylation, frequency and value for patients outcome. We examined the promoter methylation status using methylation-specific polymerase chain reaction in 100 glioblastoma tissue samples. The value for clinical outcome was calculated using Kaplan-Meier estimation with log-rank test. DNA promoter methylation was frequent event appearing more than 45 % for gene. AREG and HOXA11 methylation status was significantly associated with patient age. HOXA11 showed the tendency to be associated with patient outcome in glioblastomas. AREG gene promoter methylation showed significant correlation with poor patient outcome. AREG methylation remained significantly associated with patient survival in a Cox multivariate model including MGMT promoter methylation status. This study of new epigenetic targets has shown considerably high level of analyzed genes promoter methylation variability in glioblastoma tissue. AREG gene might be valuable marker for glioblastoma patient survival prognosis, however further analysis is needed to clarify the independence and appropriateness of the marker.

Effect of Mst1 overexpression on the growth of human hepatocellular carcinoma HepG2 cells and the sensitivity to cisplatin in vitro

Mammalian STE20-like kinase 1 (Mst1) is the mammalian homologue of Drosophila Hippo, a major inhibitor of cell proliferation in Drosophila. It ubiquitously encodes serine threonine kinase that belongs to the family of protein kinases related to yeast STE20, and is involved in cell proliferation, apoptosis, oncogenesis, and organ growth. Recent studies have shown that Mst1 has tumor-suppressor function, and the deletion or mutation of Mst1 is reported to be associated with tumorigenesis. To investigate the effect of overexpression of Mst1 on the growth of human liver cancer cell line HepG2 cells and the sensitivity to cisplatin in vitro, here we constructed recombinant eukaryotic expression vector pEGFP-N1-Mst1 containing Mst1 gene, and transiently transfected into HepG2 cells. The effects of Mst1 overexpression on the cell proliferation and apoptosis, the phosphorylation status of Yes-associated protein, and the mRNA transcript levels of connective tissue growth factor (CTGF), amphiregulin (AREG), and birc5 (Survivin) were determined. Results showed that overexpression of Mst1 inhibited cell proliferation, induced apoptosis of HepG2 cells, promoted YAP (Ser127) phosphorylation, and downregulated the mRNA expression of CTGF, AREG, and Survivin. We also investigated the relationship between the expression and cleavage of Mst1 and cisplatin-induced cell death. We found that Mst1 overexpression could induce cisplatin chemosensitivity, and cisplatin could promote the cleavage of Mst1 without affecting the expression of Mst1. Overall, our results indicated that Mst1 might be a promising anticancer target.

Inhibitory effects of a bazedoxifene/conjugated equine estrogen combination on human breast cancer cells in vitro

Breast cancer incidence is increased in women receiving menopausal hormone therapy with estrogen plus progestin but not with estrogen alone. The use of a tissue-selective estrogen complex (TSEC) has been proposed as a novel menopausal hormone therapy strategy to eliminate the requirement for a progestogen. Combination of bazedoxifene (BZA) with conjugated estrogens (CEs), the first TSEC, has shown beneficial effects. Whether it would exert antiestrogenic effects on breast cancer is not clear. To address this issue, we compared estradiol (E(2)) and CE alone on proliferation and apoptosis in MCF-7 breast cancer cells. CE stimulated growth of MCF-7 cells at a peak concentration 10-fold higher than required for E(2). Both CE and E(2) alone increased DNA synthesis and reduced apoptosis with activation of MAPK, Akt, and p70S6K and up-regulation of antiapoptotic factors survivin, Bcl-2, and X-linked inhibitor of apoptosis protein, These effects could be completely blocked by BZA. Gene expression studies demonstrated that CE and E(2) were equally potent on expression of cMyc, pS2, and WNT1 inducible signaling pathway protein 2, whereas the stimulatory effects of CE on progesterone receptor and amphiregulin expression were weaker than E(2). BZA effectively blocked each of these effects and showed no estrogen agonistic effects when used alone. Our results indicate that the stimulatory effects of E(2) or CE on breast cancer cells could be completely abrogated by BZA. These studies imply that the CE/BZA, TSEC, exerts antiestrogenic effects on breast cancer cells and might block the growth of occult breast neoplasms in postmenopausal women, resulting in an overall reduction in tumor incidence.

[The study on clinical significance of the expression of EGFL7 in laryngeal squamous cell carcinoma]

OBJECTIVE

To investigate the association and mechanism of EGFL7 expression level with the invasion and metastasis of laryngeal squamous cell carcinoma.

METHOD

RT-PCR and Western blotting were used respectively to detect the level of EGFL7 mRNA and protein form 33 fresh laryngeal carcinoma tissues and matched para-neoplastic non-tumor tissues. The immunohistochemistry technique was performed to determine microvessel density (MVD) in 33 tumor tissues. The association of EGFL7 expression and MVD with clinicopathological characteristics was analyzed.

RESULT

EGFL7 mRNA and protein expression were both significantly higher in the tumor tissues than in the paraneoplastic non-tumor tissues (P < 0.01). Furthermore, the expression of EGFL7 mRNA was highly correlated with the expression of EGFL7 protein (r = 0.786, P < 0.01). EGFL7 expression and MVD were highly correlated with clinical stage, tumor size and the presence of lymph node metastasis (P < 0.05), but was not correlated with the patients gender, age, tumor sit and tumor site differentiation (P > 0.05).

CONCLUSION

EGFL7 may have a close correlation with the development of laryngeal carcinoma via its impact on tubulogenesis and vessel shape. EGFL7 might serve as a tumor marker for assessing the progression of laryngeal carcinoma and a guide of clinical therapeutic decisions.

Detection of the epidermal growth factor receptor, amphiregulin and epiregulin in formalin-fixed paraffin-embedded human placenta tissue by matrix-assisted laser desorption/ionization mass spectrometry imaging

The study of the expression and the tissue distribution of the tyrosine kinase drug-target epidermal growth factor receptor (EGFR) is of interest in oncology as a marker of potential efficacy of treatment. It has been reported, however, that the response rates to anti-EGFR drugs are poorly linked to its expression. Clinical studies have also revealed a patient response correlation with the expression levels of two EGFR ligands; amphiregulin and epiregulin. Here, we report the development of a matrix-assisted laser desorption/ionisation mass spectrometry imaging methodology for the study of EGFR, epiregulin and amphiregulin distribution in formalin fixed paraffin embedded human placental tissue and a comparison to expression patterns obtained by immunohiostochemistry. Using on-tissue digests and imaging of specific peptides, the tissue distribution of these proteins has been obtained down to 30 microm spatial resolution.

Human chorionic gonadotropin-dependent up-regulation of epiregulin and amphiregulin in equine and bovine follicles during the ovulatory process

Little is known about the expression and regulation of epiregulin (EREG) and amphiregulin (AREG) in ovarian follicles of large monoovulatory animal species. To characterize the gonadotropin-dependent regulation of EREG and AREG mRNAs in equine follicles prior to ovulation, extracts were prepared from equine follicles collected during estrus between 0 and 39h post-hCG and corpora lutea obtained on day 8 of the estrous cycle (day 0=day of ovulation). Results from RT-PCR/Southern blot analyses showed that levels of EREG and AREG mRNAs were very low in follicles obtained at 0h but increased thereafter (P<0.05), with maximal levels observed 33-39h post-hCG. This significant increase was observed in both granulosa and theca cells. Immunohistochemistry and immunoblot analyses confirmed the hCG-dependent induction of EREG protein in both cell types. RT-PCR/Southern blot analyses of ADAM17, which encodes an enzyme that cleaves and releases soluble bioactive EREG and AREG, showed that levels of its transcript were high and remained constant throughout the period studied. Studies on the hCG-dependent regulation of EREG and AREG in bovine preovulatory follicles in vivo showed that the induction of both transcripts was transient, observed predominantly at 6h post-hCG and localized only in granulosa cells. To characterize the effect of epidermal growth factor receptor (EGFR) activation on the expression of ovulation-related genes in granulosa cells of a large monoovulatory animal species, primary cultures of bovine granulosa cells were established. Results from RT-PCR analyses revealed that EREG and AREG mRNAs were induced by forskolin treatment in vitro; but the EGFR inhibitor PD153035 suppressed the forskolin-dependent induction of several ovulation-related transcripts, including PTGS2, PTGER2, TNFAIP6, PGR, MMP1, VEGFA, and CTSL2 mRNAs. Moreover, these transcripts were induced in granulosa cell cultures by EGF, an analog of EREG and AREG. Collectively, this study identifies differences in the temporal and cellular localization of EREG and AREG expression in equine and bovine preovulatory follicles, and underscores the potential role of follicular EGFR activation in the regulation of ovulation-regulated genes in large monoovulatory species.

Amphiregulin-EGFR signaling mediates the migration of bone marrow mesenchymal progenitors toward PTH-stimulated osteoblasts and osteocytes

Intermittent administration of parathyroid hormone (PTH) dramatically increases bone mass and currently is one of the most effective treatments for osteoporosis. However, the detailed mechanisms are still largely unknown. Here we demonstrate that conditioned media from PTH-treated osteoblastic and osteocytic cells contain soluble chemotactic factors for bone marrow mesenchymal progenitors, which express a low amount of PTH receptor (PTH1R) and do not respond to PTH stimulation by increasing cAMP production or migrating toward PTH alone. Conditioned media from PTH-treated osteoblasts elevated phosphorylated Akt and p38MAPK amounts in mesenchymal progenitors and inhibition of these pathways blocked the migration of these progenitors toward conditioned media. Our previous and current studies revealed that PTH stimulates the expression of amphiregulin, an epidermal growth factor (EGF)-like ligand that signals through the EGF receptor (EGFR), in both osteoblasts and osteocytes. Interestingly, conditioned media from PTH-treated osteoblasts increased EGFR phosphorylation in mesenchymal progenitors. Using several different approaches, including inhibitor, neutralizing antibody, and siRNA, we demonstrate that PTH increases the release of amphiregulin from osteoblastic cells, which acts on the EGFRs expressed on mesenchymal progenitors to stimulate the Akt and p38MAPK pathways and subsequently promote their migration in vitro. Furthermore, inactivation of EGFR signaling specifically in osteoprogenitors/osteoblasts attenuated the anabolic actions of PTH on bone formation. Taken together, these results suggest a novel mechanism for the therapeutic effect of PTH on osteoporosis and an important role of EGFR signaling in mediating PTH's anabolic actions on bone.