Tumor Epidermal Growth Factor Receptor Research Articles

Immunohistochemical Expression of Epidermal Growth Factor Receptor in Hepatocellular Carcinoma.

Epidermal growth factor receptor (EGFR) signaling plays an important role in various cancers, including hepatocellular carcinoma (HCC). We aimed to evaluate immunoexpression of EGFR in HCC and surrounding non-tumor liver tissue and to correlate it to multiple clinicopathologic data. We analyzed 60 patients with HCC for multiple clinicopathologic characteristics and survival. Presence of the immunosignal and the percentage of positive tumor cells at the whole tumor tissue sample and adjacent cirrhotic liver tissue were semi-quantitatively determined. Nineteen patients (31.67%) were female and 41 (68.33%) were male ranging in age from 31 to 85 years, median 61.88±10.51. Mean survival time for female patients was 8.86±1.76 months, for male 13.03±1.50 months and overall survival was 11.6051±1.19 months. The most patients had: T2 status (41.67%), no enlarged lymph nodes (90%), vascular invasion (63.33%) and well differentiated (43.33%) tumors. EGFR immunoexpression was determined in range from 0% to 100% in both tumor and non-tumor tissue with mean value of 39.58% in tumor and 86.86% in cirrhotic tissue (p<0.00). Higher percent of tumor EGFR positive cells were found in cases with higher T status, higher levels of AFP and poorly differentiated carcinoma, but not significantly. Lower percent of tumor EGFR positive cells were found in patients with vascular invasion and enlarged lymph nodes, but also not significantly. EGFR expression in tumor tissue significantly influenced survival of the patients (p<0.05). The study showed that expression of EGFR in lower percentage of tumor cells was associated to favorable prognosis, making it a potential prognostic marker and therapeutic target.

Evaluation of the HER/PI3K/AKT Family Signaling Network as a Predictive Biomarker of Pathologic Complete Response for Patients With Breast Cancer Treated With Neratinib in the I-SPY 2 TRIAL.

In the I-SPY 2 TRIAL (Investigation of Serial Studies to Predict Your Therapeutic Response With Imaging and Molecular Analysis 2), the pan-erythroblastic oncogene B inhibitor neratinib was available to all hormone receptor (HR)/human epidermal growth factor receptor 2 (HER2) subtypes and graduated in the HR-negative/HER2-positive signature. We hypothesized that neratinib response may be predicted by baseline HER2 epidermal growth factor receptor (EGFR) signaling activation/phosphorylation levels independent of total levels of HER2 or EGFR proteins. Complete experimental and response data were available for between 130 and 193 patients. In qualifying analyses, which used logistic regression and treatment interaction analysis, 18 protein/phosphoprotein, 10 mRNA, and 12 DNA biomarkers that related to HER family signaling were evaluated. Exploratory analyses used Wilcoxon rank sum and t tests without multiple comparison correction. HER pathway DNA biomarkers were either low prevalence or nonpredictive. In expression biomarker analysis, only one gene (STMN1) was specifically associated with response to neratinib in the HER2-negative subset. In qualifying protein/phosphoprotein analyses that used reverse phase protein microarrays, six HER family markers were associated with neratinib response. After analysis was adjusted for HR/HER2 status, EGFR Y1173 (pEGFR) showed a significant biomarker-by-treatment interaction (P = .049). Exploratory analysis of HER family signaling in patients with triple-negative (TN) disease found that activation of EGFR Y1173 (P = .005) and HER2 Y1248 (pHER2) (P = .019) were positively associated with pathologic complete response. Exploratory analysis in this pEGFR/pHER2-activated TN subgroup identified elevated levels of estrogen receptor α (P < .006) in these patients. Activation of HER family phosphoproteins associates with response to neratinib, but only EGFR Y1173 and STMN1 appear to add value to the graduating signature. Activation of HER2 and EGFR in TN tumors may identify patients whose diseases respond to neratinib and implies that there is a subset of patients with TN disease who paradoxically exhibit HER family signaling activation and may achieve clinical benefit with neratinib; this concept must be validated in future studies.

Eps15 homology domain 1 promotes the evolution of papillary thyroid cancer by regulating endocytotic recycling of epidermal growth factor receptor.

Papillary thyroid cancer (PTC) is the most common type of thyroid malignancy, and it is often observed to overexpress epidermal growth factor receptor (EGFR). Previous research has indicated that EH domain-containing 1 (EHD1) is associated with EGFR-mediated endocytotic recycling in multiple tumor types. The objective of the present study was to determine the protein expression levels and clinical significance of EHD1, EGFR, caveolin-1 (CAV-1) and RAB11 family interacting protein 3 (RAB11FIP3) in PTC. PTC specimens were analyzed for EHD1, EGFR, CAV-1 and RAB11FIP3 expression via immunohistochemistry and western blotting. The associations between protein expression and clinicopathological features were assessed. EHD1, EGFR, CAV-1 and RAB11FIP3 expression levels were increased in human PTC. Additionally, the expression level of EHD1 protein was significantly associated with tumor size, lymph node metastasis and EGFR expression (P<0.05). CAV-1 was associated with tumor size and EGFR expression (P<0.05). EGFR was only associated with lymph node metastasis (P=0.027) and RAB11FIP3 was not associated with any clinicopathological characteristics. The correlations between EHD1 and EGFR (r=0.564, P<0.05), CAV-1 (r=0.865, P<0.01) and RAB11FIP3 (r=0.504, P<0.05) were statistically significant. Overall, EHD1, CAV-1 and RAB11FIP3, which are key proteins in endocytotic recycling, promote PTC tumorigenesis through the regulation of the transport of EGFR.

Analyzing EGFR mutations and their association with clinicopathological characteristics and prognosis of patients with lung adenocarcinoma.

Epidermal growth factor receptor (EGFR) is an important gene in the development of lung adenocarcinoma. However, there is controversy regarding the association between EGFR mutations and survival time of patients with lung adenocarcinoma. In the present study, tissue specimens and clinical data were collected from 219 patients with lung adenocarcinoma who had not undergone prior radiotherapy or chemotherapy. EGFR mutations were detected using a fluorescence polymerase chain reaction method, and the association between EGFR mutations and clinicopathological characteristics was analyzed. Overall survival (OS) curves were constructed using the Kaplan-Meier method and the influence of clinicopathological characteristics on OS was analyzed using the Cox regression model. The EGFR mutation rate was 50.7%, and the most common mutations were the L858R substitution mutation in exon 21 (L858R; 54.9%) and the deletion mutation in exon 19 (19-Del; 36%). The presence of EGFR mutations varied significantly with sex, smoking history, T stage, vascular invasion and adenocarcinoma subtypes (P<0.05). The survival time was significantly longer for female, young (<60 years-old), non-smokers or patients exhibiting EGFR mutations (G719X, 19-Del, L858R and L861Q). The survival time was also significantly longer for patients with a 19-Del mutation, early stage tumors, tyrosine kinase inhibitors targeted therapy-treated patients, for those not exhibiting nerve or vascular invasion, and for those without disease recurrence (P<0.05). Multivariate analysis revealed that tumor pathological Tumor-Node-Metastasis (pTNM) stage, nerve invasion, vascular invasion, EGFR mutation and the 19-Del mutation were independent predictors (P<0.05). Therefore, tumor pTNM stage, nerve invasion, vascular invasion and EGFR mutation status, particularly that of 19-Del, were independent prognostic factors for patients with lung adenocarcinoma.

Efficacy of thoracic radiotherapy in patients with stage IIIB–IV epidermal growth factor receptor-mutant lung adenocarcinomas who received and responded to tyrosine kinase inhibitor treatment

PurposeLarge-scale, prospective, randomized studies of the efficacy of thoracic radiotherapy (RT) in patients with unresectable stage IIIB–IV epidermal growth factor receptor (EGFR)-mutant lung adenocarcinomas who received and responded to EGFR tyrosine kinase inhibitor (TKI) treatment are not currently available. Therefore, we designed a propensity score-matched, nationwide, population-based, cohort study for estimating the effects of thoracic RT on patients with EGFR-mutant lung adenocarcinomas. Patients and methodsWe analyzed patients with unresectable stage IIIB–IV EGFR mutant lung adenocarcinomas and categorized them into two groups according to treatment modality and compared their outcomes; groups 1 and 2 consisted of patients who received EGFR TKI treatment alone until tumor progression and those who received and responded to EGFR TKI treatment and subsequently received thoracic RT for lung tumors, respectively. The patients in groups 2 and 1 were matched at a ratio of 1:4. ResultsThe matching process yielded a final cohort of 1475 patients (1180 and 295 patients in groups 1 and 2, respectively) who were eligible for further analysis. According to both univariate and multivariate Cox regression analyses, the adjusted hazard ratios (aHRs) (95% confidence interval [CI]) derived for thoracic RT for lung tumor after EGFR TKI use and tumor response (group 2) compared with EGFR TKI treatment alone (group 1) was 0.72 (0.60–0.85). ConclusionsThoracic RT might be associated with overall survival in patients with unresectable stage IIIB–IV EGFR-mutant lung adenocarcinomas who received and responded to EGFR TKI treatment.

MiR-615 inhibits cell proliferation, migration and invasion by targeting EGFR in human glioblastoma

MiR-615 and epidermal growth factor receptor (EGFR) are associated with a number of disease processes and pathogenesis. However, little is known about the mechanisms of miR-615 and EGFR in human glioblastoma multiforme (GBM). Here, we found that down-regulation of miR-615 expression occurred in GBM tissues and cells, and was inversely correlated with overall survival, relapse-free survival, WHO grade as well as EGFR expression. We further determined that miR-615 functions as a tumor suppressor by inhibiting GBM cell proliferation, cell cycle, migration and invasion, and promoting cell apoptosis. In-vivo assay validated the inhibition effect of miR-615 on tumor growth and EGFR expression. Luciferase reporter assays demonstrated that miR-615 targeted the 3′-untranslated region (3′-UTR) of EGFR. Besides, over-expression of EGFR reversed the inhibition effects of miR-615, while silencing of EGFR aggravated these inhibition effects. In conclusions, we identified that miR-615 plays a tumor suppressor role in GBM cell proliferation, migration and invasion by targeting EGFR expression, and miR-615 may act as a novel biomarker for early diagnosis or therapeutic targets of GBM.

Evaluation of epidermal growth factor receptor expression by a new scoring system in head-and-neck squamous cell carcinoma and its association with various pathological prognostic factors.

Context:Squamous cell carcinoma is an aggressive epithelial malignancy of the upper aerodigestive tract comprising 90% of all head-and-neck squamous cell carcinoma (HNSCC). It is the sixth leading cancer worldwide, with approximately 600,000 cases reported annually. It is one of the most common cancers in India.Aims and Objective:Epidermal growth factor receptor (EGFR) being the most promising marker has potentially offered new methods to prognosticate and plays an essential role in early diagnosis and treatment apart from tumor, node and metastasis staging which has been used till now. Therefore, this study has been undertaken to evaluate the expression of EGFR in HNSCC cases, according to the new scoring system and find its association with various pathological prognostic factors.Materials and Methods:Forty-eight resected specimens of oral squamous cell carcinoma were received. Cases were appropriately staged, and paraffin-embedded tumor sections, stained with hematoxylin and eosin, were graded. EGFR expression was evaluated as extent score, intensity score and total score (TS).Statistical Analysis:Data obtained were transferred on to an excel sheet. Chi-square test with and without Yate's correction was employed to compare various parameters. P ≤ 0.05 was taken as critical level of significance.Results:A significant association was observed between TS of EGFR expression and tumor grade but not with tumor stage or lymph node metastasis.Conclusion:A significant association of EGFR expression exists with tumor grade as per the new scoring system adopted. High EGFR expression suggests uncontrolled growth which depicts that EGFR upregulation may be an early event during HNSCC carcinogenesis.

Aberrant status and clinicopathologic characteristic associations of 11 target genes in 1,321 Chinese patients with lung adenocarcinoma.

The aberrant status of target genes and their associations with clinicopathologic characteristics are still unclear in primary lung adenocarcinoma. The common mutations and translocations of nine target genes were evaluated in 1,247 specimens of surgically-resected primary lung adenocarcinoma. Immunohistochemistry was used to analyze the expressions of programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) in 731 specimens. The frequency of the aberrations and their associations with clinicopathologic characteristics were analyzed. Overall, 952 (76.3%) of 1,247 patients harbored at least one target mutation or translocation: epidermal growth factor receptor (EGFR) (729, 58.5%), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) (83, 6.7%), human epidermal growth factor receptor 2 (HER2) (82, 6.6%), anaplastic lymphoma kinase (ALK) (23, 1.8%), phosphoinositide-3-kinase catalytic alpha polypeptide (PIK3CA) (20, 1.6%), Ret proto-oncogene RET (15, 1.2%), ROS proto-oncogene 1 receptor tyrosine kinase (ROS1) (12, 1.0%), B-raf proto-oncogene (BRAF) (9, 0.7%), neuroblastoma RAS viral (v-ras) oncogene homolog (NRAS) (3, 0.2%). Fourteen (1.9%) of 731 patients were PD-1 positive and 95 (13.0%) were PD-L1 positive in tumor cells. In men and smokers, there were more frequent KRAS mutations (both P<0.001) and PD-L1 positive tumors (P<0.001, P=0.005, respectively), and less frequent EGFR mutations (P=0.049, <0.001, respectively). In ground-glass opacity (GGO) or ground-glass nodules (GGN), there were more HER2 (P=0.033) but less EGFR (P=0.025) and PIK3CA mutations (P=0.012), and ALK translocations (P=0.014). EGFR (P<0.001), KRAS mutations (P=0.004) and PD-L1 positive tumors (P=0.046) were more frequent in older patients, while HER2 (P<0.001), ALK (P=0.005) and ROS1 aberrations (P=0.044) were less frequent. Invasive mucinous adenocarcinoma was significantly associated with KRAS and ALK aberrations (both P<0.001), while solid predominant adenocarcinoma was associated with ROS1 translocations (P=0.036) and PD-L1 expression (P<0.001). KRAS, HER2, and ALK aberrations were scarce in patients with EGFR mutations (all P<0.001), while PD-L1 positive tumors positively correlated with ALK translocations (P=0.031) and negatively correlated with HER2 mutations (P=0.019). Most patients with primary lung adenocarcinoma harbored target gene aberrations. The frequency of each alteration differed in patients depending on clinicopathologic characteristics.

Commentary: Treatment Considerations for Patients With Epidermal Growth Factor Receptor-Mutated Non-Small Cell Lung Cancer Brain Metastases in the Era of Tyrosine Kinase Inhibitors

Brain metastasis is a serious complication of non-small cell lung cancer (NSCLC) affecting up to 40% of NSCLC patients. A subset of NSCLC tumors has mutations in the epidermal growth factor receptor (EGFR) gene, and determination of tumor EGFR mutation status is essential in guiding treatment decisions, as it directly affects the treatment approach. Patients with EGFR-mutated NSCLC have a higher cumulative incidence of brain metastases, and are especially sensitive to EGFR tyrosine kinase inhibitors (TKIs). Patients with newly diagnosed EGFR-mutated lung cancer presenting to a neurosurgeon with a new diagnosis of brain metastases now have a variety of treatment options available, including whole brain radiation therapy, stereotactic radiosurgery, surgical resection, chemotherapy, and targeted therapeutics such as the EGFR TKIs. In this review, we discuss the impact of EGFR mutation status on brain and leptomeningeal metastasis treatment considerations. Additionally, we present clinical cases of patients treated with EGFR TKIs alone and in combination with other therapies to highlight treatment alternatives.

EGF receptor signaling, phosphorylation, ubiquitylation and endocytosis in tumors in vivo.

Despite a well-established role for the epidermal growth factor receptor (EGFR) in tumorigenesis, EGFR activities and endocytosis in tumors in vivo have not been studied. We labeled endogenous EGFR with GFP by genome-editing of human oral squamous cell carcinoma cells, which were used to examine EGFR-GFP behavior in mouse tumor xenografts in vivo. Intravital multiphoton imaging, confocal imaging of cryosections and biochemical analysis revealed that localization and trafficking patterns, as well as levels of phosphorylation and ubiquitylation of EGFR in tumors in vivo closely resemble patterns and levels observed in the same cells treated with 20-200 pM EGF in vitro. Consistent with the prediction of low ligand concentrations in tumors, EGFR endocytosis was kinase-dependent and blocked by inhibitors of clathrin-mediated internalization; and EGFR activity was insensitive to Cbl overexpression. Collectively, our data suggest that a small pool of active EGFRs is sufficient to drive tumorigenesis by signaling primarily through the Ras-MAPK pathway.

Family with sequence similarity 83, member B is a predictor of poor prognosis and a potential therapeutic target for lung adenocarcinoma expressing wild-type epidermal growth factor receptor.

Lung adenocarcinoma (ADC) patients with tumors that harbor no targetable driver gene mutation, such as epidermal growth factor receptor (EGFR) gene mutations, have unfavorable prognosis, and thus, novel therapeutic targets are required. Family with sequence similarity 83, member B (FAM83B) is a biomarker for squamous cell lung cancer. FAM83B has also recently been shown to serve an important role in the EGFR signaling pathway. In the present study, the molecular and clinical impact of FAM83B in lung ADC was investigated. Matched tumor and adjacent normal tissue samples were obtained from 216 patients who underwent complete lung resection for primary lung ADC and were examined for FAM83B expression using cDNA microarray analysis. The associations between FAM83B expression and clinicopathological parameters, including patient survival, were examined. FAM83B was highly expressed in tumors from males, smokers and in tumors with wild-type EGFR. Multivariate analyses further confirmed that wild-type EGFR tumors were significantly positively associated with FAM83B expression. In survival analysis, FAM83B expression was associated with poor outcomes in disease-free survival and overall survival, particularly when stratified against tumors with wild-type EGFR. Furthermore, FAM83B knockdown was performed to investigate its phenotypic effect on lung ADC cell lines. Gene silencing by FAM83B RNA interference induced growth suppression in the HLC-1 and H1975 lung ADC cell lines. FAM83B may be involved in lung ADC tumor proliferation and can be a predictor of poor survival. FAM83B is also a potential novel therapeutic target for ADC with wild-type EGFR.

Reticulocalbin-2 enhances hepatocellular carcinoma proliferation via modulating the EGFR-ERK pathway.

This corrects the article DOI: 10.1038/onc.2017.230.

Overexpression of CXCR4 promotes invasion and migration of non-small cell lung cancer via EGFR and MMP-9.

The aim of the present study was to verify whether overexpression of CXC receptor 4 (CXCR4) promotes the invasion and migration of non-small cell lung cancer (NSCLC) via epidermal growth factor receptor (EGFR) and matrix metallopeptidase-9 (MMP-9), and to detect the association between CXCR4, EGFR and MMP-9. The effects of overexpression of CXCR4 on lung cancer cell functions were investigated by migration and invasion assays. Western blotting and zymograph assays were used to analyze the protein expression levels of EGFR and the production of MMP-9, respectively. Immunohistochemistry was applied to analyze the expression of EGFR, CXCR4 and MMP-9 in NSCLC. Statistical analyses were used to detect the associations among EGFR, CXCR4 and MMP-9 in NSCLC. Finally, survival analyses were performed. CXCR4 overexpression enhanced cell motility and invasion. CXCR4 also promoted expression of EGFR and elevated MMP-9 production. CXCR4, EGFR and MMP-9 were highly expressed in NSCLC, and were not identified as associated with age and sex (P>0.05). However, they were associated with tumor differentiation and lymph node metastasis (P<0.05). CXCR4, EGFR and CXCR4 expression were positively associated with one another in NSCLC (P<0.05). In addition, patients with positive expression of CXCR4, EGFR or MMP-9 in tumors exhibited significantly shorter overall survival compared with those with negative expression (P<0.05). In conclusion, CXCR4 overexpression enhanced cell motility and invasion via EGFR and MMP-9. CXCR4, EGFR and MMP-9 were identified as highly expressed in NSCLC, and there was positive correlation among them.

FDA Approval Summary: Pembrolizumab for Treatment of Metastatic Non-Small Cell Lung Cancer: First-Line Therapy and Beyond.

This is the first U.S. Food and Drug Administration approval of a checkpoint inhibitor for first-line treatment of lung cancer. This approval expands the pembrolizumab indication in second-line treatment of lung cancer to include all patients with programmed death-ligand 1-expressing non-small cell lung cancer.

Clinical validation of a highly sensitive assay to detect EGFR mutations in plasma cell-free DNA from patients with advanced lung adenocarcinoma.

BackgroundCirculating tumor DNA (ctDNA) is a promising biomarker for noninvasive epidermal growth factor receptor (EGFR) mutations detection in lung cancer patients, but the existing methods have limitations in sensitivity or in availability. In this study, we evaluated the performance of a novel assay called ADx-SuperARMS in detecting EGFR mutations in plasma cell-free DNA from patients with advanced lung adenocarcinoma.MethodsA total of 109 patients with metastatic advanced adenocarcinoma were recruited who provided both blood samples and matched tumor tissue samples. EGFR mutation status in plasma samples were tested with ADx-SuperARMS EGFR assay and tumor tissue samples were tested with ADx-ARMS EGFR assay. The clinical sensitivity, specificity, positive prediction value (PPV), and negative prediction value (NPV) of ADx-SuperARMS EGFR assay were calculated by using EGFR mutation status in tumor tissue as standard reference. A receiver operating characteristic (ROC) analysis was implemented and an area under the curve (AUC) was calculated to evaluate sensitivity and specificity of exon 19 deletion (E19Del) and L858R mutation detection. The objective response rate (ORR) were calculated according to the EGFR mutation status determined by ADx-superARMS as well.Results0.2% analytical sensitivity and 100% specificity of the ADx-SuperARMS EGFR assays for EGFR E19Del, L858R, and T790M mutants were confirmed by using a series of diluted cell line DNA. In the clinical study, EGFR mutations were detected in 45.9% (50/109) of the plasma samples and in 56.9% (62/109) of the matched tumor tissue samples. The sensitivity, specificity, PPV and NPV of the ADx-SuperARMS EGFR assay for plasma EGFR mutation detection were 82.0% (50/61), 100% (48/48), 100% (50/50), and 81.4% (48/59), respectively. In ROC analysis, ADx-SuperARMS achieved sensitivity and specificity of 88% and 99% in E19Dels as well as sensitivity and specificity of 89% and 100% in L858R, respectively. Among the 35 patients who were plasma EGFR mutation positive and treated with first generation of EGFR-tyrosine kinase inhibitors (TKIs), 23 (65.7%) achieved partial response, 11 (31.4%) sustained disease, and 1 (2.9%) progressive disease. The ORR and disease control rate (DCR) were 65.7% and 97.1%, respectively.ConclusionsADx-SuperARMS EGFR assay is likely to be a highly sensitive and specific method to noninvasively detect plasma EGFR mutations of patients with advanced lung adenocarcinoma. The EGFR mutations detected by ADx-SuperARMS EGFR assay could predict the efficacy of the treatment with first generation of EGFR-TKIs. Hence, EGFR blood testing with ADx-SuperARMS could address the unmet clinical needs.

Which treatment is preferred for advanced non-small-cell lung cancer with wild-type epidermal growth factor receptor in second-line therapy? A meta-analysis comparing immune checkpoint inhibitor, tyrosine kinase inhibitor and chemotherapy.

BackgroundThe recommendations regarding the optimum treatment for advanced non-small-cell lung cancer (NSCLC) patients with wild-type (WT) epidermal growth factor receptor (EGFR) tumors remain unclear. This meta-analysis was conducted to assess the efficacy among programmed death-ligand 1 (PD-L1)/programmed death-1 (PD-1) antibody, EGFR-tyrosine kinase inhibitors (TKI) and chemotherapy in second-and third-line therapy.Patients and methodsRandomized trials investigating two of the three treatments were searched and included. Multiple treatments comparison and pairwise comparison were performed to assess overall survival (OS) and progression-free survival (PFS), expressed as hazard ratios (HRs). The effect of prespecified study-level characteristics was assessed by subgroup analysis and meta-regression.Results12 randomized trials accruing 3341 advanced patients with WT EGFR tumors were analyzed. PD-1/PD-L1 antibody was associated with significantly longer OS and PFS than chemotherapy (OS: HR 0.67, 95% CrI 0.60–0.75; PFS: HR 0.83, 95% CrI 0.73–0.95) and TKI (OS: HR 0.59, 95% CrI 0.50–0.70; PFS: HR 0.75, 95% CrI 0.66–0.84) , while chemotherapy was associated with significantly longer OS (HR 0.88, 95% CrI 0.77–0.99) and PFS (HR 0.75, 95% CrI 0.66–0.84) than TKI.ConclusionsFor advanced NSCLC patients with WT-EGFR tumors in second- or third-line therapy, PD-1/PD-L1 antibody appeared to be the most efficacious treatment, which was followed by chemotherapy. EGFR-TKI was worse than chemotherapy.

Reticulocalbin-2 enhances hepatocellular carcinoma proliferation via modulating the EGFR-ERK pathway.

Hepatocellular carcinoma (HCC) is a major health threat worldwide. Although the involvement of reticulocalbin-2 (RCN2) in cell differentiation has been reported, its function in oncogenesis is poorly understood. Here, we showed that RCN2 was upregulated in tumors compared with adjacent non-tumorous tissues in HCC patients and RCN2 expression clinically correlated with tumor size, disease recurrence and survival rate. Both knockdown and knockout of RCN2 significantly inhibited HCC cell proliferation by inducing G1/S transition arrest and downregulating cyclin D1 expression, while the proliferative ability was restored in knockout HCC cells with exogenously expressed RCN2. Mechanistically, we demonstrated that RCN2 interacted with the epidermal growth factor receptor (EGFR). Knockout of RCN2 in HCC cells not only inhibited activation of the EGFR-ERK pathway by blocking EGF-mediated EGFR dimerization and internalization but also suppressed cell proliferation and EGFR phosphorylation under long exposure to EGF. We further showed that knockout of RCN2 inhibited EGFR phosphorylation, Ki-67 expression and tumor growth in nude mice. Moreover, we demonstrated that RCN2 knockout sensitized HCC cells to tyrosine kinase inhibitors, including erlotinib, lapatinib and sunitinib. Taken together, our results indicate that RCN2 plays a pivotal role in HCC cell proliferation and tumor growth presumably through regulating activation of the EGFR-ERK pathway. Our work also suggests that RCN2 is a potential therapeutic target of HCC.

Abstract 1032: Identification of Ran binding protein 6 as a novel negative regulator of EGFR and candidate tumor suppressor in glioblastoma

Abstract Amplification and overexpression of the epidermal growth factor receptor (EGFR) are common in glioblastoma (GBM) and frequently associated with silencing of the phosphatase and tensin homologue (PTEN) tumor suppressor. PTEN silencing has been associated with clinical resistance to EGFR tyrosine kinase inhibitors, in part by raising EGFR levels. Here, we investigated the effect of PTEN on the EGFR signaling complex by EGFR affinity immunopurification and mass spectrometry with and without PTEN knockdown. We identified Ran binding protein 6 (RanBP6), a 125-kDa protein of previously unknown functions, as EGFR interacting protein in PTEN expressing, but not PTEN knockdown cells. Further studies of the effect of RanBP6 on EGFR revealed that RanBP6 depletion by shRNA or CRISPR/Cas9-mediated gene silencing resulted in increased EGFR mRNA levels and upregulation of EGFR promoter activity. Consistent with a model of a negative EGFR regulation by RanBP6, we observed an inverse correlation between RanBP6 and EGFR mRNA levels in PTEN wildtype but not PTEN altered cancer cells in a large panel of human cancer cell lines (Cancer Cell Line Encyclopedia). To further understand the mechanism of how RanBP6 negatively regulates EGFR mRNA level, we found that RanBP6 interacted with nuclear Ran-GTPase and repressed EGFR transcription by promoting nuclear import of Signal transducer and activator of transcription 3 (STAT3). Lastly, RanBP6 appeared to be frequently deleted on chromosome 9p in GBM. We showed that RanBP6 silencing raised EGFR levels and signal output and accelerated in-vivo glioma growth. Our results establish a novel function of RanBP6 as a link between EGFR signaling and the Ran-mediated nuclear import pathway, and identify RanBP6 as candidate tumor suppressor on chromosome 9p. Citation Format: Wan-Ying Hsieh, Barbara Oldrini, Hediye Erdjument-Bromage, Paolo Codega, Maria S. Carro, Igor Vivanco, Dan Rohle, Carl Campos, Craig Bielski, Barry Taylor, Paul Tempst, Massimo Squatrito, Ingo K. Mellinghoff. Identification of Ran binding protein 6 as a novel negative regulator of EGFR and candidate tumor suppressor in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1032. doi:10.1158/1538-7445.AM2017-1032

Abstract 2078: CK-101 (RX518), a mutant-selective inhibitor of EGFR that overcomes T790M-mediated resistance in NSCLC

Abstract Patients with non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutations initially respond to small molecule inhibitors of the EGFR tyrosine kinase such as gefitinib and erlotinib. However, secondary mutations in the kinase domain lead to acquired resistance to these inhibitors and limited clinical efficacy, with the EGFR T790M mutation being the most common mechanism of acquired resistance in more than half the patients that experience disease progression. CK-101 (also known as RX518) is a novel, irreversible, orally administered EGFR kinase inhibitor that specifically targets the mutant forms of EGFR, including T790M, while exhibiting minimal activity toward the wild-type (WT) EGFR. WT EGFR inhibition is believed to drive the commonly observed side effects of skin rash and diarrhea. The 50% inhibitory concentrations (IC50s) of CK-101 and 2 reference compounds, afatinib and AZD-9291, were determined in cell proliferation assays in human cancer cell lines in vitro after incubation for 72 hours. Xenograft studies were conducted in BALB/c nude mice or SCID/Beige mice using once daily oral administration of CK-101 or afatinib for 14 or 21 days. CK-101 selectively inhibited cell proliferation of cell lines expressing both the activating (e.g. HCC827, IC50 &amp;lt;0.015 µM) and resistance mutations (NCI-H1975, IC50 &amp;lt;0.005 µM), but was much less potent at inhibiting proliferation of cell lines expressing the WT form of the receptor (e.g. A431, IC50 &amp;gt;0.5 µM; i.e., CK-101 was over 100 fold less potent against A431 than against NCI-H1975). Single agent CK-101 significantly inhibited tumor growth in EGFR-mutated NSCLC tumor xenograft models, with no activity in a WT EGFR tumor xenograft model. In a xenograft study of PC-9 cells (exon 19 deletion) in SCID/Beige mice, CK-101 inhibited tumor growth by up to 90% (p &amp;lt;0.001). In a xenograft study of NCI-H1975 cells (L858R/T790M double mutant) in BALB/c nude mice, CK-101 inhibited tumor growth by up to 95% (p &amp;lt;0.001). The pre-clinical findings from this work strongly supported the clinical development of CK-101, and a first-in-human study of CK-101 was initiated in September 2016. Citation Format: Xiangping Qian, Yong-Liang Zhu, Edward Cullen, Robert M. Niecestro, James F. Oliviero. CK-101 (RX518), a mutant-selective inhibitor of EGFR that overcomes T790M-mediated resistance in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2078. doi:10.1158/1538-7445.AM2017-2078

Metapristone (RU486 metabolite) suppresses NSCLC by targeting EGFR-mediated PI3K/AKT pathway.

Therapies targeting epidermal growth factor receptor (EGFR) can effectively treat with non-small cell lung cancer (NSCLC), but NSCLC’s drug resistance makes it intractable. Herein, we showed that RU486 metabolite metapristone inhibited the proliferation of various NSCLC cell lines with either wild (A549, H1299, H520) or mutated EGFR (H1975, HCC827). The suppression was resulted from inhibition by metapristone of EGFR signaling pathways through down-regulating the EGFR, PTEN, as well as AKT and ERK proteins. In addition, metapristone inhibited anti-apoptotic marker Bcl-2, and activated pro-apoptotic key signaling proteins caspase-3, and poly (ADP-ribose) polymerase. Metapristone induced A549 and H1975 cell cycle via arrest at the G0-G1 stage. What’s more, metapristone inhibited the growth of NSCLC xenografts in BALB/c nude mice through decreasing the expression of tumor growth biomarkers PCNA and EGFR. Taken together, the present study demonstrated that metapristone suppressed NSCLC proliferation by promoting apoptosis via decrease the cellular EGFR-mediated PI3K/AKT pathways. The results suggest metapristone a new treatment for EGFR-overexpressed NSCLC.