Epidermal Growth Factor Receptor Protein Expression Research Articles

Cytosolic PKM2 stabilizes mutant EGFR protein expression through regulating HSP90-EGFR association.

This corrects the article DOI: 10.1038/onc.2015.397.

Study on the expression of epidermal growth factor receptor protein during benzo(a)pyrene induced carcinogenesis

Objective: To explore the expression of epidermal growth factor receptor(EGFR) protein during benzo(a)pyrene (BaP) induced carcinogenesis. Methods: This study, we firstly utilized immunofluorescence assay and Western-blot to examine EGFR expression of the BaP which was constructed previously by project team induced malignant transformation human bronchial epithelial cell (BTC) and the control (16HBE cell). Then, we selected 36 healthy SD rats, divided into two groups according to simple random method, 18 rats each group. The constructed rat lung neoplasm model induced by pulmonary injection of BaP (10 mg/ml of BaP solution in 0.2 ml corn oil), contrast group use 0.2 ml corn oil, lung tissue was collected and the EGFR expression of lung tissue was detected by immunofluorescence assay and Western blot. T analysis was used to test the different of EGFR between two groups. Results: Immunofluorescence analysis showed that the EGFR expression in BTC was significantly higher than 16HBE cell. Meanwhile, Western blot also was used to confirmed this result, the relative expression of EGFR protein in the rats of the model group the control group were 1.04±0.13 and 2.32±0.12, respectively, and the difference was statistically significance (t=12.39, P<0.001). In vivo, well-defined tumor was found in the rat with pulmonary injection of BaP, and the lung showed diffuse alveolar septal thickening, alveolar wall destruction and pulmonary alveoli fusion, which suggested that the rat lung neoplasm model was constructive successfully. Furthermore, we found the EGFR expression of lung was increased dramatically in the rat lung neoplasm model by immunofluorescence detection and Western blot. The relative expression of EGFR protein in the rats of the model group the control group were 0.21±0.03 and 1.30±0.07, respectively, and the difference was statistically significance (t=12.84, P<0.001). Conclusion: Expression of EGFR protein was increased during BaP carcinogenesis, and EGFR may play an important role in the carcinogenesis of BaP.

Abstract P5-05-05: The role and regulation mechanism of HOXB5 in human breaset cancer cells

Abstract HOX genes are transcription factors that play important roles in body patterning and cell fate specification during normal development. Among of these, HOXB5, is involved in a variety of developmental processes, particularly during the enteric nervous system (ENS) development, and thus, abnormalities in HOXB5 function during embryo stages lead to Hirschsprung's disease. Importantly, many HOX genes, including HOXB5, are expressed not only during embryogenesis but also in adults and are dysregulated in various cancers. In a previous study, we found aberrant overexpression of HOXB5 in breast cancer tissues and cell lines and demonstrated that HOXB5 is important in the regulation of cell proliferation in breast cancer cells. Also, HOXB5 induces invasive potential through epithelial-mesenchymal transition (EMT). The relationship between HOXB5 and phenotypic changes in MCF7 breast cancer cells has been studied, however, HOXB5 functions as a transcription factor and its involvement in signaling pathways remain unclear. In this study, we selected putative downstream target genes of HOXB5, such as interleukin (IL)-6, Snail2 and epidermal growth factor receptor (EGFR) by PCR array analysis. These genes have been reported to be involved in cacner progression, which is characterised by increased growth speed and invasiveness of the tumor cells. Here, we discovered that HOXB5 transcriptionally upregulates the promoter activity of these genes. Chromatin immunoprecipitation (ChIP) analysis to confirm direct binding of HOXB5 to the promoter region is now ongoing. Since we found that HOXB5 induces EGFR protein expression and SRC phosphorylation, we will further investigate signaling pathway components to understand the underlying molecular mechanisms of HOXB5 action in breast cancer. Citation Format: Kim JM, Lee J-Y, Kim MH. The role and regulation mechanism of HOXB5 in human breaset cancer cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-05-05.

OA23.01 Anti-EGFR Monoclonal Antibodies plus Chemotherapy in the First-Line Treatment of Advanced NSCLC: A Meta-Analysis

Monoclonal Antibodies (mAbs) against the Epidermal Growth Factor Receptor (EGFR) in association with platinum-based doublet chemotherapy have emerged as a potential first-line treatment option for advanced non-small cell lung cancer (NSCLC). This study was conducted to systematically review available data and evaluate the efficacy and toxicity of anti-EGFR mAbs plus chemotherapy vs chemotherapy alone for advanced NSCLC. We carried out a search on network databases and oncology conference abstracts for studies between 1990 and January 2016. Only prospective randomized clinical trials were included. Primary endpoints were overall survival (OS) and toxicity frequency. Secondary endpoints were progression-free survival (PFS) and overall response rate (ORR). Subgroup analysis was performed assessing histological subtypes, EGFR protein expression by immunohistochemistry (IHC), EGFR gene copy number by fluorescence in-situ hybridization (FISH), EGFR mutation status, and smoking status. Seven studies (2 with necitumumab and 5 with cetuximab) were included with 5,057 patients. Compared to chemotherapy alone, significant benefits were demonstrated by the addition of anti-EGFR mAb to chemotherapy in OS (HR 0.90; 95%CI 0.84-0.95), PFS (HR 0.93; 95%CI 0.87-0.98), and ORR (OR 1.27; 95%CI 1.06-1.51). In subgroup analyses, the association of anti-EGFR mAb was associated with improved OS among patients with squamous histology (HR 0.84; 95%CI 0.76-0.92), tumours with high EGFR expression by IHC (HR 0.83; 95%CI 0.70-0.98), and smokers (HR 0.87; 95%CI 0.79-0.96). Patients with squamous histology and high EGFR expression by IHC achieved the highest benefit with the association (HR 0.71; 95%CI 0.59-0.86). The OS with the association also seemed to be higher in EGFR FISH negative and in EGFR wild-type tumours, but without statistical significance. Chemotherapy plus anti-EGFR mAb caused more grade 3 or worse adverse events (OR 1.73; 95%CI 1.50-2.00), remarkedly these known to be associated with anti-EGFR therapy, such as acne-like rash (OR 34.13; 95%CI 16.40-71.00) and hypomagnesemia (OR 6.23; 95%CI 3.04-12.77). Anti-EGFR therapy plus platinum-based doublet chemotherapy as first-line treatment demonstrated significant efficacy benefits with acceptable toxicity for advanced NSCLC. This benefit is more expressive among squamous histology with high EGFR expression. EGFR protein expression by IHC seems to be a predictive marker for survival in the association group. Further research is needed to corroborate these findings.

A tumor-targeting cRGD-EGFR siRNA conjugate and its anti-tumor effect on glioblastoma in vitro and in vivo

The epidermal growth factor receptor (EGFR) is an important anti-tumor target. The development of novel molecular-targeted anti-tumor drugs that can target the interior of tumor cells and specifically silence EGFR expression is valuable and promising. In this work, a promising anti-tumor conjugate comprising methoxy-modified EGFR siRNA and cyclic arginine-glycine-aspartic acid (cRGD) peptides, which selectively bind to αvβ3 integrins, was synthesized and examined. To prepare cRGD-EGFR siRNA (cRGD-siEGFR), cRGD was covalently conjugated to the 5′-end of an siRNA sense strand using a thiol-maleimide linker. The cellular uptake and cytotoxicity of cRGD-siEGFR in vitro were tested using an αvβ3-positive U87MG cell line. In vivo bio-distribution, anti-tumor activity, immunogenicity and toxicity were investigated in a nude mouse tumor model through repeated i.v. administration of cRGD-siEGFR (7 times over a 48 h interval). Analyses of in vitro data showed that cRGD-siEGFR silenced EGFR expression effectively, with high tumor targeting ability. Administration of cRGD-siEGFR to tumor-bearing nude mice led to significant inhibition of tumor growth, obvious reduction of EGFR expression and down-regulation of EGFR mRNA and protein in tumor tissue. Furthermore, serum biochemistry and pathological section evaluation did not indicate any serious toxicity of cRGD-siEGFR in vivo. cRGD-siEGFR is likely a promising candidate with high targeting ability, substantial anti-tumor effects and low toxicity in vitro and in vivo.

MiR-370 regulates cell proliferation and migration by targeting EGFR in gastric cancer.

Epidermal growth factor receptor (EGFR) is known to be overexpressed in ~30% of gastric cancer (GC) cases, and may serve as an effective biomarker for predicting the clinical benefit of anti-EGFR therapy. However, the mechanism underlying the regulation of EGFR expression remains unknown. Evidence indicates that post-transcriptional regulation may exist in the process of EGFR expression. In the present study, we aimed to explore whether miR-370 is involved in this process, and how it impacts the biological behaviors of GC cells. In the present study, we first determined the role of EGFR in GC by means of an EGFR overexpression plasmid and siRNAs. Then, the expression levels of EGFR protein and mRNA in GC tissues were analyzed through immunohistochemistry and quantitative RT-PCR (RT-qPCR). Bioinformatics tools and dual-luciferase assay were applied to predict and validate the relevant miRNA targeting EGFR. Finally, human GC MGC-803 cells were selected to explore the effect of miRNA on cell proliferation and migration. We found that suppression of EGFR inhibited the proliferation and migration of GC cells. In addition, the levels of EGFR protein in the GC tissues were ~4times higher than that in the corresponding paired non-cancerous tissues while the mRNA levels of EGFR were only ~2-fold as high as that in the adjacent non-cancerous tissues. Bioinformatics tools predicted that miRNA-370 was a regulator of EGFR and dual‑luciferase assay validated that miR-370 could directly bind to the 3'-untranslated region (3'-UTR) of EGFR mRNA. Meanwhile, an inverse correlation between miR-370 and EGFR was found in the GC tissues. Overexpression of miR-370 suppressed the proliferation and migration of GC cells, while downregulation of miR-370 promoted proliferation and migration. The present study may provide new information for understanding the molecular mechanism underlying the regulation of EGFR protein expression in GC and may be of important clinical significance to guide targeted therapy.

Overexpression of microRNA-133b is associated with the increased survival of patients with hepatocellular carcinoma after curative hepatectomy: Involvement of the EGFR/PI3K/Akt/mTOR signaling pathway.

The aim of the present study was carried out to investigate the association of microRNA-133b (miRNA-133b) expression with the prognosis of patients with hepatocellular carcinoma (HCC) after curative hepatectomy. In the present study, the expression of miRNA-133b in HCC tissues was determined to be lower than that noted in the adjacent normal tissues. Overall and disease-free survival of the HCC patients with high miRNA-133b expression was observably extended, compared with the HCC patients with low miRNA‑133b expression. Moreover, the overexpression of miRNA-133b inhibited cell proliferation, increased lactate dehydrogenase (LDH) activity, induced apoptosis and promoted caspase‑3/-8 activities and Bax/Bcl-2 protein expression in HCC cells, whereas the protein expression of epidermal growth factor receptor (EGFR) was significantly decreased. The overexpression of miRNA-133b significantly suppressed PI3K, phosphorylated (p)-Akt and p-mTOR protein expression in HCC cells. GW2974, an EGFR inhibitor, suppressed the protein expression of EGFR, inhibited cell proliferation, increased LDH activity, induced apoptosis and promoted caspase-3/-8 activities and Bax/Bcl-2 protein expression, downregulated PI3K, p-Akt and p-mTOR protein expression in the transfected HCC cells overexpressing miRNA-133b. Taken together, our results indicate that the overexpression of miRNA-133b is associated with the increased survival of HCC patients after curative hepatectomy. The effects of miRNA-133b in HCC are mediated through the EGFR/PI3K/Akt/mTOR signaling pathway.

Correlation of EGFR-expression with safety and efficacy outcomes in SQUIRE: a randomized, multicenter, open-label, phase III study of gemcitabine–cisplatin plus necitumumab versus gemcitabine–cisplatin alone in the first-line treatment of patients with stage IV squamous non-small-cell lung cancer

SQUIRE demonstrated addition of necitumumab to gemcitabine and cisplatin significantly improved survival in patients with stage IV sq-NSCLC. Here, we report additional outcomes for the subpopulation of patients with tumor epidermal growth factor receptor (EGFR) protein expression. Patients with pathologically confirmed stage IV sq-NSCLC were randomized 1:1 to receive a maximum of six 3-week cycles of gemcitabine (1250 mg/m(2) i.v., days 1 and 8) and cisplatin (75 mg/m(2) i.v., day 1) chemotherapy with or without necitumumab (800 mg i.v., days 1 and 8). Patients in the chemotherapy plus necitumumab group with no progression continued on necitumumab alone until disease progression or intolerable toxicity. SQUIRE included mandatory tissue collection. EGFR protein expression was detected by immunohistochemistry (IHC) in a central laboratory. Exploratory analyses were pre-specified for patients with EGFR protein expressing (EGFR > 0) and non-expressing (EGFR = 0) tumors. A total of 982 patients [90% of intention-to-treat (ITT)] had evaluable IHC results. The large majority of these patients (95%) had tumor samples expressing EGFR protein; only 5% had tumors without detectable EGFR protein. Overall survival (OS) for EGFR > 0 patients was significantly longer in the necitumumab plus gemcitabine-cisplatin group than in the gemcitabine-cisplatin group {stratified hazard ratio (HR) 0.79 [95% confidence interval (CI) 0.69, 0.92; P = 0.002]; median 11.7 months (95% CI 10.7, 12.9) versus 10.0 months (8.9, 11.4)}. Additionally, an OS benefit was seen in all pre-specified subgroups in EGFR > 0 patients. However, OS HR for EGFR = 0 was 1.52. Adverse events of interest with the largest difference between treatment groups in EGFR > 0 patients (Grade ≥3) were hypomagnesemia (10% versus <1%) and skin rash (6% versus <1%). In line with SQUIRE ITT, addition of necitumumab to gemcitabine-cisplatin significantly prolonged OS and was generally well tolerated in the subpopulation of patients with EGFR-expressing advanced sq-NSCLC. The benefit from addition of necitumumab to chemotherapy was not apparent in this analysis for the small subgroup of patients with non-EGFR-expressing tumors. NCT00981058.

Coexpression of periostin and EGFR in patients with esophageal squamous cell carcinoma and their prognostic significance.

BackgroundBoth periostin (PN) and epidermal growth factor receptor (EGFR) can predict the prognosis of several carcinomas alone. However, coexpression of PN and EGFR in esophageal squamous cell carcinoma (ESCC) still remains unknown. We aimed to clarify their relationship with clinicopathological factors and prognostic significance of their coexpression in ESCC.Patients and methodsIn this single-center retrospective study, immunohistochemistry was performed to evaluate the expression of PN and EGFR in ESCC and paracarcinomatous tissues of 83 patients. The quantitative expression levels of PN and EGFR were examined in two ESCC and tumor-adjacent tissues. The levels of PN and EGFR expression were correlated with clinicopathological parameters by the χ2 or Kruskal–Wallis method. Spearman’s rank correlation test was performed to determine the relationship between PN and EGFR expression levels. Kaplan–Meier and Cox regression analyses were used to detect the prognostic factors of disease-free survival (DFS) and overall survival (OS).ResultsThe high expression of PN protein in ESCC tissues was significantly associated with tumor length (P=0.044), differentiation grade (P=0.003), venous invasion (P=0.010), invasion depth (P=0.007), lymphatic metastasis (P=0.000), and tumor stage (P=0.000). The high expression of EGFR protein in ESCC tissues was only significantly related to lymphatic metastasis (P=0.000), invasion depth (P=0.022), and tumor stage (P=0.000). Kaplan–Meier analysis showed that high expression of PN was closely correlated to reduced OS (P=0.000) and DFS (P=0.000), which was consistent with EGFR expression. Cox regression analysis identified PN and EGFR as independent poor prognostic factors of OS and DFS in the ESCC patients (P<0.05). Moreover, the risk of death for the ESCC patients with low expression of two biomarkers and high expression of single biomarker was 0.243 times (P=0.000) and 0.503 times (P=0.030), respectively, than that for patients with high expression of two biomarkers.ConclusionPN and EGFR are related to miscellaneous clinicopathologic characteristics. Coexpression of PN and EGFR is more closely to be of predictive value on ESCC development and progression, which may offer a novel and potential target strategy for ESCC treatment in the future.

MiR-143 suppresses the proliferation of NSCLC cells by inhibiting the epidermal growth factor receptor.

MicroRNAs (miRs) regulate the proliferation and metastasis of numerous cancer cell types. It was previously reported that miR-143 levels were downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines, and that the migration and invasion of NSCLC cells was inhibited upon suppression of cell proliferation and colony formation by the upregulation of miR-143. Epidermal growth factor receptor (EGFR), which is a vital factor in the promotion of cancer cell proliferation and has been investigated as a potential focus in cancer therapy, has been reported to be a possible target of miR-143. The present study aimed to investigate the role of miR-143 in NSCLC using NSCLC cell lines and primary cells from NSCLC patients. NSCLC cells were co-transfected with EGFR and miR-143, and the mRNA and protein expression of EGFR were analyzed. Furthermore, the activity of the transfected cancer cells with regard to colony formation, migration, invasion and apoptosis were evaluated. The levels of miR-143 were decreased in the NSCLC cell lines and primary cells from patients with NSCLC compared with the controls. Following transfection with miR-143, the ability of NSCLC cells to proliferate, form colonies, migrate and invade was inhibited. Similarly, knockdown of EGFR led to the suppression of NSCLC cell proliferation. The mRNA and protein expression levels of EGFR were significantly reduced following miR-143 overexpression, and the level of miR-143 was inversely correlated with that of EGFR in NSCLC cells. The results of the present study demonstrated that miR-143 was able to suppress NSCLC cell proliferation and invasion by inhibiting the effects of EGFR, suggesting that EGFR may be considered a potential target for NSCLC therapy.

Abstract 2185: Sann-Joong-Kuey-Jian-Tang can inhibit human breast cancer cells through dural- blocking both the Ras/Raf/MEK/ERK and Ras/PI3K/Akt/mTOR pathways

Abstract Sann-Joong-Kuey-Jian-Tang (SJKJT) consists of 17 species of medicinal herbs, is a traditional Chinese medicine prescription, and has been used as complementary medication for a number of types of solid cancer in Taiwan. Transmembrane tyrosine kinase has been strongly implicated in the growth, survival, and metastasis of a wide variety of human tumors. The phosphoinositide-3-kinase (PI3K)/AKT/ mammalian target of rapamycin (mTOR) and RAS/RAF/MEK/ERK pathways are two of the most frequently dysregulated kinase cascades in human cancer were well documented. Both pathways represent important signal transduction mechanisms that facilitate the proliferation and survival of cancers driven by growth factor receptors, such as vascular endothelial growth factor receptor (VEGFR), insulin-like growth factor-I receptor (IGF-IR), human epidermal growth factor receptor 2 (HER2) or epidermal growth factor receptor (EGFR).The individual downstream components of these signaling cascades either through somatic mutation or epigenetic modification, are also known to be frequently altered in cancer, thus contributing to tumorigenesis and resistance to anticancer therapies. Targeting both the Ras/Raf/MEK/ERK and Ras/PI3K/Akt/mTOR Pathways for suppressing Inhibitor Resistant Cells is necessary. In the present study, the human breast cancer BT-20 and MCF-7 cells were treated with SJKJT in vitro. The cytotoxicity of SJKJT were evaluated by 3–(4,5–dimethylthiazol–2–y1)–2,5–diphenyltetrazolium bromide (MTT) assay. The effects of SJKJT on the protein expressions of VEGFR, IGF-IR, PI3K, AKT, mTOR, Ras, Raf, MEK and ERK and β-actin in the BT-20 and MCF-7 cells were examined by western blot analysis. The results showed that SJKJT can induce the proliferation inhibition with time and dose dependent. As a potential mechanism, it was noted that SJKJT treatment significantly inhibited the activity of the Ras/Raf/MEK/ERK and Ras/PI3K/Akt/mTOR pathways, which played a protective role against the cytotoxicity. In addition, it was demonstrated that SJKJT treatment inhibited the protein expressions of VEGFR, EGFR and IGF-IR significantly. These results suggest that one of the molecular mechanisms for SJKJT to inhibit breast cancer BT-20 and MCF-7 cells maybe through inhibiting the protein expressions of VEGFR, EGFR, IGF-IR and both Ras/Raf/MEK/ERK and Ras/PI3K/Akt/mTOR pathways. The use of traditional chinese medicine prescription SJKJT may become a feasible novel therapy option. Further studies are warranted to fully elucidate its mechanisms of action. Citation Format: CHIN CHENG SU. Sann-Joong-Kuey-Jian-Tang can inhibit human breast cancer cells through dural- blocking both the Ras/Raf/MEK/ERK and Ras/PI3K/Akt/mTOR pathways. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2185.

4 Epidermal growth factor receptor positively regulates sFlt1 secretion

Introduction Preeclampsia is associated with elevated placental secretion of the anti-angiogenic factor sFlt1. Surprisingly, little is understood about its regulation, characterizing this may identify therapeutic leads. Placenta has by far the highest Epidermal Growth Factor Receptor (EGFR) expression of non-malignant tissue. It is localized to the placental surface and elevated in preeclamptic placenta. Objectives Our objective was to characterize EGFR pathway expression in preeclamptic placenta and to assess whether EGFR signaling regulates sFlt1 secretion in primary human placenta. Methods RNA and protein were extracted from a cohort of severe early onset preeclamptic ( n =25) placentas as well as gestational matched normotensive controls ( n =25). EGFR mRNA expression was assessed as well as protein levels of phosphorylated EGFR and the key downstream signaling molecules Erk1/2, Akt and STAT3. We next isolated primary trophoblast from normotensive term placenta and (1) inhibited EGFR signaling with gefitinib (orally available EGFR inhibitor), or (2) inhibited the downstream EGFR signaling cascades with seven different small molecule inhibitors. mRNA expression of sFlt1 variants as well as protein secretion was assessed. EGFR expression was also assessed in primary trophoblasts treated with esomeprazole, pravastatin and sulfasalazine. Results mRNA expression of EGFR was significantly upregulated in preeclamptic placentas. Active EGFR, Erk1/2, Akt and STAT3 were all also significantly increased in preeclamptic placenta. Inhibiting EGFR in primary trophoblasts with gefitinib significantly reduced sFlt1-e15a mRNA and protein expression and total sFlt1 secretion by 30–70% from baseline (Fig. 1). Inhibiting the downstream adaptor molecules MEK1/2 (U0126), Erk/12 (PD98059), c-RAF (ZM336372) and JAK2 (AG490) also induced a significant dose dependent reduction in both sFlt1-e15a and total sFlt1 mRNA and protein expression. Additionally, treating primary trophoblasts with esomeprazole, pravastatin and sulfasalazine all significantly down regulated EGFR mRNA and protein expression coincident with significantly reduced sFlt1 secretion. Conclusions We have identified a new level of molecular regulation for sFlt1. EGFR signaling positively regulate sFlt1 secretion. The implications are that identifying drugs that block EGFR signaling may be a novel therapeutic strategy.

Novel cell-penetrating peptide-loaded nanobubbles synergized with ultrasound irradiation enhance EGFR siRNA delivery for triple negative Breast cancer therapy

The lack of safe and effective gene delivery strategies remains a bottleneck for cancer gene therapy. Here, we describe the synthesis, characterization, and application of cell-penetrating peptide (CPP)-loaded nanobubbles (NBs), which are characterized by their safety, strong penetrating power and high gene loading capability for gene delivery. An epidermal growth factor receptor (EGFR)-targeted small interfering RNA (siEGFR) was transfected into triple negative breast cancer (TNBC) cells via prepared CPP-NBs synergized with ultrasound-targeted microbubble destruction (UTMD) technology. Fluorescence microscopy showed that siEGFR and CPP were loaded on the shells of the NBs. The transfection efficiency and cell proliferation levels were evaluated by FACS and MTT assays, respectively. In addition, in vivo experiments showed that the expression of EGFR mRNA and protein could be efficiently downregulated and that the growth of a xenograft tumor derived from TNBC cells could be inhibited. Our results indicate that CPP-NBs carrying siEGFR could potentially be used as a promising non-viral gene vector that can be synergized with UTMD technology for efficient TNBC therapy.

Expressions of CD147 and EGFR protein and their relationship with metastasis and prognosis of gastric cancer

Objective To investigate the expressions of extracellular matrix metalloproteinase inducer molecule CD147 and epidermal growth factor receptor (EGFR) protein in gastric cancer and their relationship with the pathological behavior and prognosis. Methods Immunohistochemical staining was used to detect the expressions of CD147 and EGFR protein in 63 cases of gastric cancer and 40 cases of paracancerous normal tissues. The study was also combined with analysis of the pathological behavior and clinical follow-up survey of gastric cancer. Results The positive expression rates of CD147 and EGFR protein in gastric cancer were 77.8%(49/63) and 42.9%(27/63), respectively, which were higher than those in paracancerous normal tissues 25.0% and 0 (χ2=27.851, P=0.000; χ2=23.233, P=0.000). In gastric cancer, the expressions of CD147 and EGFR were closely related to the depth invasion (χ2=5.992, P=0.014; χ2=13.148, P=0.000), TNM stages (χ2=8.481, P=0.004; χ2=14.589, P=0.000), lymph node metastasis (χ2=5.270, P=0.022; χ2=20.261, P=0.000) and prognosis of patients (χ2=5.606, P=0.018; χ2=4.982, P=0.026). The expression of CD147 was also significantly correlated with Ki-67 expression (χ2=10.481, P=0.001). CD147 expression was positively correlated with EGFR expression(r=0.309, P=0.014). Conclusion The expressions of CD147 and EGFR are closely related to carcinogenesis, metastasis and survival time of gastric cancer. Detecting the expressions of CD147 and EGFR may be prognostic indicators of gastric cancer. Key words: Stomach neoplasms; Prognosis; Antigens, CD147; Epidermal growth factor

Hinokitiol inhibits vasculogenic mimicry activity of breast cancer stem/progenitor cells through proteasome-mediated degradation of epidermal growth factor receptor.

Hinokitiol, alternatively known as β-thujaplicin, is a tropolone-associated natural compound with antimicrobial, anti-inflammatory and antitumor activity. Breast cancer stem/progenitor cells (BCSCs) are a subpopulation of breast cancer cells associated with tumor initiation, chemoresistance and metastatic behavior, and may be enriched by mammosphere cultivation. Previous studies have demonstrated that BCSCs exhibit vasculogenic mimicry (VM) activity via the epidermal growth factor receptor (EGFR) signaling pathway. The present study investigated the anti-VM activity of hinokitiol in BCSCs. At a concentration below the half maximal inhibitory concentration, hinokitiol inhibited VM formation of mammosphere cells derived from two human breast cancer cell lines. Hinokitiol was additionally indicated to downregulate EGFR protein expression in mammosphere-forming BCSCs without affecting the expression of messenger RNA. The protein stability of EGFR in BCSCs was also decreased by hinokitiol. The EGFR protein expression and VM formation capability of hinokitiol-treated BCSCs were restored by co-treatment with MG132, a proteasome inhibitor. In conclusion, the present study indicated that hinokitiol may inhibit the VM activity of BCSCs through stimulating proteasome-mediated EGFR degradation. Hinokitiol may act as an anti-VM agent, and may be useful for the development of novel breast cancer therapeutic agents.

P85α promotes nucleolin transcription and subsequently enhances EGFR mRNA stability and EGF-induced malignant cellular transformation.

p85α is a regulatory subunit of phosphatidylinositol 3-kinase (PI3K) that is a key lipid enzyme for generating phosphatidylinositol 3, 4, 5-trisphosphate, and subsequently activates signaling that ultimately regulates cell cycle progression, cell growth, cytoskeletal changes, and cell migration. In addition to form a complex with the p110 catalytic subunit, p85α also exists as a monomeric form due to that there is a greater abundance of p85α than p110 in many cell types. Our previous studies have demonstrated that monomeric p85α exerts a pro-apoptotic role in UV response through induction of TNF-α gene expression in PI3K-independent manner. In current studies, we identified a novel biological function of p85α as a positive regulator of epidermal growth factor receptor (EGFR) expression and cell malignant transformation via nucleolin-dependent mechanism. Our results showed that p85α was crucial for EGFR and nucleolin expression and subsequently resulted in an increase of malignant cellular transformation by using both specific knockdown and deletion of p85α in its normal expressed cells. Mechanistic studies revealed that p85α upregulated EGFR protein expression mainly through stabilizing its mRNA, whereas nucleolin (NCL) was able to bind to egfr mRNA and increase its mRNA stability. Consistently, overexpression of NCL in p85α−/− cells restored EGFR mRNA stabilization, protein expression and cell malignant transformation. Moreover, we discovered that p85α upregulated NCL gene transcription via enhancing C-Jun activation. Collectively, our studies demonstrate a novel function of p85α as a positive regulator of EGFR mRNA stability and cell malignant transformation, providing a significant insight into the understanding of biomedical nature of p85α protein in mammalian cells and further supporting that p85α might be a potential target for cancer prevention and therapy.

The status of epidermal growth factor receptor in borderline ovarian tumours.

The majority of borderline ovarian tumours (BOTs) behave in a benign fashion, but some may show aggressive behavior. The reason behind this has not been elucidated. The epidermal growth factor receptor (EGFR) is known to contribute to cell survival signals as well as metastatic potential of some tumours. EGFR expression and gene status have not been thoroughly investigated in BOTs as it has in ovarian carcinomas. In this study we explore protein expression as well as gene mutations and amplifications of EGFR in BOTs in comparison to a subset of other epithelial ovarian tumours.We studied 85 tumours, including 61 BOTs, 10 low grade serous carcinomas (LGSCs), 9 high grade serous carcinomas (HGSCs) and 5 benign epithelial tumours. EGFR protein expression was studied using immunohistochemistry. Mutations were investigated by Sanger sequencing exons 18-21 of the tyrosine kinase domain of EGFR. Cases with comparatively higher protein expression were examined for gene amplification by chromogenic in situ hybridization. We also studied the tumours for KRAS and BRAF mutations.Immunohistochemistry results revealed both cytoplasmic and nuclear EGFR expression with variable degrees between tumours. The level of nuclear localization was relatively higher in BOTs and LGSCs as compared to HGSCs or benign tumours. The degree of nuclear expression of BOTs showed no significant difference from that in LGSCs (mean ranks 36.48, 33.05, respectively, p=0.625), but was significantly higher than in HGSCs (mean ranks: 38.88, 12.61 respectively, p< 0.001) and benign tumours (mean ranks: 35.18, 13.00 respectively, p= 0.010). Cytoplasmic expression level was higher in LGSCs. No EGFR gene mutations or amplification were identified, yet different polymorphisms were detected. Five different types of point mutations in the KRAS gene and the V600E BRAF mutation were detected exclusively in BOTs and LGSCs.Our study reports for the first time nuclear localization of EGFR in BOTs. The nuclear localization similarities between BOTs and LGSCs and not HGSCs support the hypothesis suggesting evolution of LGSCs from BOTs. We also confirm that EGFR mutations and amplifications are not molecular events in the pathogenesis of BOTs.

MIIP accelerates epidermal growth factor receptor protein turnover and attenuates proliferation in non-small cell lung cancer.

The migration and invasion inhibitory protein (MIIP) has been discovered recently to have inhibitory functions in cell proliferation and migration. Overexpression of MIIP reduced the intracellular steady-state level of epidermal growth factor receptor (EGFR) protein in lung cancer cells with no effect on EGFR mRNA expression compared to that in the control cells. This MIIP-promoted EGFR protein degradation was reversed by proteasome and lysosome inhibitors, suggesting the involvement of both proteasomal and lysosomal pathways in this degradation. This finding was further validated by pulse-chase experiments using 35S-methionine metabolic labeling. We found that MIIP accelerates EGFR protein turnover via proteasomal degradation in the endoplasmic reticulum and then via the lysosomal pathway after its entry into endocytic trafficking. MIIP-stimulated downregulation of EGFR inhibits downstream activation of Ras and blocks the MEK signal transduction pathway, resulting in inhibition of cell proliferation. The negative correlation between MIIP and EGFR protein expression was validated in lung adenocarcinoma samples. Furthermore, the higher MIIP protein expression predicts a better overall survival of Stage IA-IIIA lung adenocarcinoma patients who underwent radical surgery. These findings reveal a new mechanism by which MIIP inhibits cell proliferation.

Prognostic and Therapeutic Markers in Chordomas: A Study of 287 Tumors.

Chordomas are slow-growing malignant neoplasms. Determination of histopathologic prognostic factors using a large cohort study has been limited by their low incidence. In this retrospective study, we investigated the clinical, histopathologic, and immunohistochemical prognostic factors in 287 chordomas from 111 patients assessed by central pathologic review. Expression patterns of a variety of markers, including vascular endothelial growth factor (VEGF), mTOR pathway, c-kit, HER2, epidermal growth factor receptor (EGFR) and STAT3, and KRAS, BRAF, EGFR, and PIK3CA mutations were analyzed. On univariate analysis, the results confirm surgery as the best treatment, as judged by patient progression-free survival (PFS) and overall survival (OS). Proton therapy, the presence of a dedifferentiated component, mitotic figures, and Ki67 and p53 labeling indices correlated with PFS . Necrosis and apoptosis correlated with OS. Based on these findings, we propose a histopathologic grading system that correlates with PFS and OS. On multivariate analysis, extent of resection, tumor grade, and proton therapy were independent prognostic factors of PFS; extent of resection, tumor location, and grade were independent prognostic factors of OS. Based on the expression of EGFR, pSTAT3, VEGF, and mTOR pathway proteins, (in 85.9%, 79.1%, 85.7%, and 46% of chordomas, respectively), and 2 new mutations in the PIK3CA gene, we also provide evidence for potential therapeutic targets.

Epidermal growth factor receptor mutations in nonsmall cell lung carcinoma patients in Kuwait.

Context:Nonsmall cell lung carcinoma (NSCLC) is the most frequently diagnosed form of lung cancer in Kuwait. NSCLC samples from Kuwait have never been screened for epidermal growth factor receptor (EGFR) gene aberration, which is known to affect treatment options.Aims:This study investigated the feasibility of using fine-needle aspiration (FNA) material for mutational screening, and whether common EGFR mutations are present in NSCLC samples from Kuwait.Settings and Design:Eighteen NSCLC samples from five Kuwaitis and 13 non-Kuwaitis were included in this study.Materials and Methods:DNA was extracted from FNA cell blocks and screened for EGFR gene mutations using peptide nucleic acid (PNA)-clamp assay, and EGFR gene amplification using fluorescent in situ hybridization (EGFR-FISH). EGFR protein expression was assessed using immunohistochemistry.Results:Five EGFR mutations were detected in five non-Kuwaiti NSCLC patients (27.8%). EGFR gene amplification was evident in 10 samples (55.5%) by direct amplification or under the influence of chromosomal polysomy. Four samples had EGFR mutations and EGFR gene amplification, out of which only one sample had coexisting EGFR overexpression.Conclusions:Given the evidence of EGFR gene alterations occurring in NSCLC patients in Kuwait, there is a need to incorporate EGFR gene mutational screen for NSCLC patients to implement its consequent use in patient treatment.