Overexpression Of Epidermal Growth Factor Receptor Research Articles

Androgen Receptor Activation in Glioblastoma Can Be Achieved by Ligand-Independent Signaling through EGFR-A Potential Therapeutic Target.

Androgen receptor (AR) is a ligand-mediated transcription factor that belongs to the superfamily of steroid receptors. AR is overexpressed in most glioblastomas and is a potential therapeutic target. In prostate and breast cancers, AR activation can be achieved also by a ligand-independent signaling through receptor tyrosine kinases such as epidermal growth factor receptor (EGFR). Considering its major role in glioblastoma, we explored whether EGFR is involved in AR signaling in this tumor. Analysis of mRNA expression in 28 glioblastoma samples with quantitative real-time reverse-transcription polymerase chain reaction revealed a positive and significant correlation between AR and EGFR mRNA expression levels (R = 0.47, p = 0.0092), which was validated by The Cancer Genome Atlas dataset (n = 671) analysis (R = 0.3, p = 0.00006). Using Western blotting and immunofluorescence staining, we showed that the transduced overexpression of EGFR or its variant EGFRvIII in the U87MG cells induced AR protein overexpression and nuclear translocation and Protein kinase B (AKT) S473 and AR S210/213 phosphorylation. The EGFR kinase inhibitor afatinib and the AKT inhibitor MK2206 reduced AR nuclear translocation. Afatinib diminished AKT phosphorylation at 30 min and 6 h in the EGFR- and EGFRvIII-overexpressing cells, respectively, and decreased AR phosphorylation in EGFR-overexpressing cells at 4 h. Afatinib or MK2206 combination therapy with the AR antagonist enzalutamide in the EGFR and EGFRvIII-overexpressing cells had synergistic efficacy. Our findings suggest that EGFR signaling is involved in AR activation in glioblastoma and buttresses the concept of combining an EGFR signaling inhibitor with AR antagonists as a potential glioblastoma treatment.

The immunoexpression of epidermal growth factor receptor in cutaneous squamous cell carcinoma.

Although cutaneous squamous cell carcinomas (cSCCs) account for only 20–25% of non-melanoma skin cancers (NMSCs), they are responsible for most deaths attributable to NMSCs. Apart from SCC seric level, which increases in late-stage disease, no other predictive biomarker for cSCC exists. Epidermal growth factor receptor (EGFR) serves as a predictive biomarker and therapeutic target in numerous malignancies. EGFR immunoexpression is highly elevated in head and neck mucosal SCC. However, its immunoexpression pattern, its relationship with prognosis and survival, and the effect of EGFR targeted therapy in advanced cSCC have not been clarified. We assessed EGFR immunoexpression in 18 cases of cSCC and correlated our findings with the clinicopathological features. Immunohistochemical stainings with anti-EGFR monoclonal antibodies were practiced and the membrane and cytoplasmic immunostaining intensity and quality in the tumors and the non-lesional epithelium were analyzed. Membrane EGFR immunoexpression within the tumors increased with the tumor grade. EGFR overexpression was more frequently found in head and neck cSCCs. We did not find a direct relationship between cytoplasmic EGFR immunoexpression and clinicopathological findings and prognosis. Our results confirm that increased EGFR immunoexpression correlates with aggressive cSCC phenotypes and underline the need for novel treatments for these patients.

Radiomic differentiation of breast cancer molecular subtypes using pre-operative breast imaging – A systematic review and meta-analysis

IntroductionBreast cancer has four distinct molecular subtypes which are discriminated using gene expression profiling following biopsy. Radiogenomics is an emerging field which utilises diagnostic imaging to reveal genomic properties of disease. We aimed to perform a systematic review of the current literature to evaluate the value radiomics in differentiating breast cancers into their molecular subtypes using diagnostic imaging. MethodsA systematic review was performed as per PRISMA guidelines. Studies assessing radiomictumour analysis in differentiatingbreast cancer molecular subtypeswere included. Quality was assessed using the radiomics quality score (RQS). Diagnostic sensitivity and specificity of radiomic analyses were included for meta-analysis; Study specific sensitivity and specificity were retrieved and summary ROC analysis were performed to compile pooled sensitivities and specificities. ResultsForty-one studies were included. Overall, there were 10,090 female patients (mean age of 47.6 ± 11.7 years, range: 21–93) and molecular subtypewas reported in 7,693 of cases, with Luminal A (LABC), Luminal B (LBBC), Human Epidermal Growth Factor Receptor-2 overexpressing (HER2+), and Triple Negative (TNBC) breast cancers representing 51.3%, 19.9%, 12.3% and 16.3% of tumour respectively. Seven studies provided radiomic analysis to determine molecular subtypes using mammography to differentiateTNBCvs.others (sensitivity: 0.82,specificity:0.79). Thirty-five studies reported on radiomic analysis of magnetic resonance imaging (MRI); LABC versus others(sensitivity:0.78,specificity:0.83),HER2+versusothers(sensitivity:0.87,specificity:0.88), andLBBCversusTNBC (sensitivity: 0.79,specificity:0.88) respectively. ConclusionRadiomic tumour assessment of contemporary breast imaging provide a novel option in determining breast cancer molecular subtypes. However, amelioration of such techniques are required and genetic expression assessment will remain the gold standard.

Study of human epidermal growth factor receptor (HER2/neu) expression in primary colorectal carcinoma in a tertiary care hospital

Introduction: Colorectal cancer (CRC) mainly affects the middle-aged and elderly population with a gradual increase in its incidence. Various studies have found human epidermal growth factor receptor (HER2/neu) overexpression in CRC and its associated prognostic outcome. HER2/neu activates various signaling pathways which leads to cell proliferation and survival, and thereby its overexpression causes excessive tumor cell growth and migration. Aims and Objectives: The aim of this study was to determine the percentage of HER2/neu positive and negative cases and to correlate it with the grade and stage of the tumor. Materials and Methods: The study was carried out for 2 years in the Department of Pathology, MGM Medical College and Hospital, Aurangabad, and included 35 resected specimens of colorectal carcinoma. Histopathological examination was studied and for immunohistochemical (IHC) staining, paraffin wax-embedded tissues were immune stained for HER2/neu. Results: Of 35 cases, there were 18 women and 17 men. Approximately 28.57% cases were in the age group of 41–50 years with the mean age being 54 years. In 37.14% of cases, the tumor was located in the ascending colon. Approximately 77.14% cases were Grade 2. In total, 57.14% cases were at stage T3. Six cases were HER2/neu positive and 29 cases were HER2/neu negative. Conclusion: A significant correlation was found between HER2/neu expression with histologic grade and stage of the tumor. HER2/neu targeted therapeutic strategies have the potential to change treatment course and outcome. Hence, HER2/neu can be used as a biomarker in patients with CRC to assess their prognostic outcome.

DCE-MRI quantitative transport mapping for noninvasively detecting hypoxia inducible factor-1α, epidermal growth factor receptor overexpression, and Ki-67 in nasopharyngeal carcinoma patients

BackgroundDynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has the potential to noninvasively detect expression of hypoxia inducible factor-1-alpha (HIF-1α), epidermal growth factor receptor (EGFR), and Ki-67 in nasopharyngeal carcinoma (NPC) by quantitatively measuring tumor blood flow, vascularity, and permeability. PurposeWe aim to explore the utility of DCE-MRI in detecting HIF-1α, EGFR, and Ki-67 expression levels using traditional Kety’s/Tofts’ modeling and quantitative transport mapping (QTM). Materials and methodsEighty-nine NPC patients underwent DCE-MRI before treatment were enrolled. DCE-MRI was processed to generate the following kinetic parameters: |u| and D from the QTM model, tumor blood flow (TBF) from Kety’s model, and Ktrans, Ve, and Kep from Tofts’ model. Pretreatment levels of HIF-1α, EGFR, and Ki-67 were assessed by immunohistochemistry and classified into low and high expression groups. Results|u| (p < 0.001) and TBF (p = 0.015) values were significantly higher in the HIF-1α high-expression group compared to low-expression group. Only Ktrans (p = 0.016) was significantly higher in the EGFR high-expression group. Only |u| (p < 0.001) values were significantly higher in the Ki-67 high-expression group compared to low-expression group. Multiple linear regression analyses showed that |u| independently correlated with HIF-1α and Ki-67 expression, and Ktrans independently correlated with EGFR. The areas under the ROC curves of |u| for HIF-1α and Ki-67, and Ktrans for EGFR were 0.83, 0.74, and 0.70, respectively. Conclusion|u| and Ktrans derived from DCE-MRI may be considered as noninvasive imaging markers for detecting hypoxia and proliferation in NPC patients.

Improved anti-cancer effect of epidermal growth factor-gold nanoparticle conjugates by protein orientation through site-specific mutagenesis

ABSTRACT Epidermal growth factor (EGF)-nanoparticle conjugates have the potential for cancer therapeutics due to the unique cytotoxic activity in cancer cells with EGF receptor (EGFR) overexpression. To gain its maximum activity, the EGF molecule should be immobilized on the nanoparticle surface in a defined orientation so as the bulky nanoparticle will not interfere EGF-EGFR interaction. Herein, we demonstrate successful enhancement of the anti-cancer activity of EGF-gold nanoparticle conjugates (EGF-GNPs) by controlling the EGF orientation on the surface of the nanoparticle through site-specific mutagenesis. Three lysine-free EGF variants (RR, RS, and SR) were designed, where two endogenous lysine residues were replaced with either arginine (R) or serine (S). The EGF mutants can be conjugated to the GNPs in a controlled orientation through the single amino group at the N-terminus. The ability of the mutants to induce extracellular signal-regulated kinase (ERK) phosphorylation was no different from wild type EGF (WT) in soluble form, rather lowered for one mutant (RR). However, after conjugated to GNPs, the SR mutants exhibited an enhanced biological activity than WT, in terms of ERK phosphorylation and growth inhibition of cancer cells. Further analysis of the binding constant of each mutant indicated the emergent enhanced activity of the GNP conjugates of the SR mutant was not solely contributed to the orientation, but to its higher binding activity to EGFR. These results validate the present genetic recombination strategy to improve the anticancer efficiency of EGF-GNPs.

High tumour mutational burden and EGFR/MAPK pathway activation are therapeutic targets in metastatic porocarcinoma.

Eccrine porocarcinoma (EPC) is a rare skin cancer arising from the eccrine sweat glands. Due to the lack of effective therapies, metastasis is associated with a high mortality rate. To investigate the drivers of EPC progression. We carried out genomic and transcriptomic profiling of metastatic EPC (mEPC), validation of the observed alterations in an EPC patient-derived cell line, confirmation of relevant observations in a large patient cohort of 30 tumour tissues, and successful treatment of a patient with mEPC under the identified treatment regimens. mEPC was characterized by a high tumour mutational burden (TMB) with an ultraviolet signature, widespread copy number alterations and gene expression changes that affected cancer-relevant cellular processes such as cell cycle regulation and proliferation, including a pathogenic TP53 (tumour protein 53) mutation, a copy number deletion in the CDKN2A (cyclin dependent kinase inhibitor 2A) region and a CTNND1/PAK1 [catenin delta 1/p21 (RAC1) activated kinase 1] gene fusion. The overexpression of EGFR (epidermal growth factor receptor), PAK1 and MAP2K1 (mitogen-activated protein kinase kinase 1; also known as MEK1) genes translated into strong protein expression and respective pathway activation in the tumour tissue. Furthermore, a patient-derived cell line was sensitive to EGFR and MEK inhibition, confirming the functional relevance of the pathway activation. Immunohistochemistry analyses in a large patient cohort showed the relevance of the observed changes to the pathogenesis of EPC. Our results indicate that mEPC should respond to immune or kinase inhibitor therapy. Indeed, the advanced disease of our index patient was controlled by EGFR-directed therapy and immune checkpoint inhibition for more than 2years. Molecular profiling demonstrated high TMB and EGFR/MAPK pathway activation to be novel therapeutic targets in mEPC.

MiR‑125a‑5p and miR‑7 inhibits the proliferation, migration and invasion of vascular smooth muscle cell by targeting EGFR.

The ectopic proliferation, migration and invasion of vascular smooth muscle cells (VSMCs) contributes to the progression of various human vascular diseases. Accumulating evidence has demonstrated that microRNAs (miRs) exert vital functions in the proliferation and invasion of VSMCs. The current study aimed to elucidate the functions of miR-125a-5p and miR-7 in VSMCs and investigate the associated molecular mechanisms. The results of EdU and reverse transcription-quantitative PCR assays revealed that platelet-derived growth factor (PDGF)-BB enhanced the proliferation of VSMCs and significantly reduced the expression of miR-125a-5p and miR-7. miR-125a-5p or miR-7 overexpression significantly ameliorated PDGF-BB-induced proliferation, migration and invasion of VSMCs. Furthermore, the results demonstrated that epidermal growth factor receptor (EGFR) may be a target mRNA of miR-125a-5p and miR-7 in VSMCs. The results of western blot analysis indicated that co-transfection of miR-125a-5p mimics or miR-7 mimics distinctly decreased the protein expression of EGFR in EGFR-overexpressed VSMCs. Moreover, rescue experiments indicated that EGFR overexpression alleviated the suppressive impact of the miR-125a-5p and miR-7 s on the growth, migration and invasion of VSMCs. In conclusion, the current study identified that miR-125a-5p and miR-7 repressed the growth, migration and invasion of PDGF-BB-stimulated VSMCs by, at least partially, targeting EGFR. The current study verified that miR-125a-5p and miR-7 may be used as feasible therapeutic targets for cardiovascular diseases.

EGFR-IL-6 Signaling Axis Mediated the Inhibitory Effect of Methylseleninic Acid on Esophageal Squamous Cell Carcinoma.

Epidemiological and experimental evidence indicate that selenium is associated with a reduced risk of some cancers, including esophageal cancer. However, the exact mechanism is still unclear. In the present study, we used esophageal squamous cell carcinoma (ESCC) cell lines and animal models to explore the anti-cancer mechanism of methylseleninic acid (MSA). Firstly, MSA treatment dramatically attenuated Epidermal Growth Factor Receptor (EGFR) protein expression but did not alter mRNA levels in ESCC cells. On the contrary, EGFR overexpression partly abolished the inhibitory effect of MSA. With a microRNA-array, we found MSA up-regulated miR-146a which directly targeted EGFR, whereas miR-146a inhibitor antagonized MSA-induced decrease of EGFR protein. We further used 4-nitroquinoline-1-oxide (4NQO)-induced esophageal tumor mice model to evaluate the inhibitory effect of MSA in vivo. MSA treatment significantly decreased the tumor burden and EGFR protein expression in tumor specimens. Furthermore, MSA treatment inhibited EGFR pathway and subsequntly reduced Interleukin-6 (IL-6) secretion in the supernatant of cancer cell lines. MSA-induced IL-6 suppression was EGFR-dependent. To further evaluate the association of IL-6 and the anti-tumor effect of MSA on esophageal cancer, we established the 4NQO-induced esophageal tumor model in IL-6 knock-out (IL-6 KO) mice. The results showed that IL-6 deficiency did not affect esophageal tumorigenesis in mice, but the inhibitory effect of MSA was abolished in IL-6 KO mice. In conclusion, our study demonstrated that MSA upregulated miR-146a which directly targeted EGFR, and inhibited EGFR protein expression and pathway activity, subsequently decreased IL-6 secretion. The inhibitory effect of MSA on esophageal cancer was IL-6 dependent. These results suggested that MSA may serve as a potential drug treating esophageal cancer.

Cigarette Smoke Containing Acrolein Upregulates EGFR Signaling Contributing to Oral Tumorigenesis In Vitro and In Vivo.

Simple SummaryOral squamous cell carcinoma (OSCC) is one of the most common smoking-related cancer types in the world. Better understanding of the pathophysiology of OSCC would lead to the development of novel therapeutic options. The epidermal growth factor receptor (EGFR) pathway plays a crucial role in the development of OSCC, and aberrant EGFR expression levels have been associated with smoking. Cigarette smoke contains large amounts of aldehydes such as acrolein, which is a highly reactive environmental toxin. In this study, our results present that acrolein is important in oncogenic transformation through activating the EGFR signaling pathway, contributing to oral carcinogenesis. To the best of our knowledge, this is the first study to provide molecular evidence, showing that cigarette smoke containing acrolein contributes to EGFR amplification and activation of downstream signaling in OSCC. Thus, acrolein might be a novel target for early detection and prevention of oral cancer in the future.Oral squamous cell carcinoma (OSCC) accounts for 80–90% of all intraoral malignant neoplasms. The single greatest risk factor for oral cancer is tobacco use, including cigarettes, cigars, chewing tobacco, and snuff. Aberrations of the epidermal growth factor receptor (EGFR) pathway features prominently in oral tumorigenesis and progression. It was shown that cigarette smoking (CS) is associated with worse prognosis in OSCC patients and overexpression of EGFR in tumor tissue. However, the mechanism by which cigarette smoking induced EGFR pathway activation remains to be fully elucidated. Acrolein, an IARC group 2A carcinogen, is a highly reactive aldehyde found in CS. Here we report that acrolein is capable of inducing tumorigenic transformation in normal human oral keratinocytes (NOK). The acrolein-transformed NOK cells showed EGFR copy number amplification, increased EGFR expression, and activation of downstream ERK and AKT signaling pathway. No p53 mutations were observed in acrolein-transformed NOK cells. Inhibiting EGFR pathway using an anti-EGFR antibody, cetuximab, inhibits tumor growth. Furthermore, by examining tissue sample from patients, we found an increased EGFR copy number was positively associated with acrolein-induced DNA damages in OSCC patients. Taken together, our results indicate that acrolein is important in tumorigenic transformation through amplification of EGFR and activating the downstream signaling pathway, contributing to oral carcinogenesis. This is the first study to provide molecular evidence showing that CS containing acrolein contributes to EGFR amplification in OSCC.

Multimodal Bone Metastasis-associated Epidermal Growth Factor Receptor Imaging in an Orthotopic Rat Model.

Purpose To develop multimodality imaging techniques for measuring epidermal growth factor receptor (EGFR) as a therapy-relevant and metastasis-associated molecular marker in triple-negative mammary adenocarcinoma metastases. Materials and Methods An orthotopic bone metastasis EGFR-positive, triple-negative breast cancer (TNBC) model in rats was used for bioluminescence imaging, SPECT/CT, PET/CT, and MRI with quantitative analysis of transcripts (n = 22 rats). Receptor-specific MRI of EGFR expression in vivo was performed by acquiring spin-echo T1-weighted images after sequential administration of a pair of anti-EGFR antigen binding fragments, F(ab')2, conjugated to either horseradish peroxidase or glucose oxidase, which have complementing activities, as well as paramagnetic (gadolinium[III]-mono-5-hydroxytryptamide of 2,2',2''-(10-(2,6-dioxotetrahydro-2H-pyran-3-yl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid, or Gd-5HT-DOTAGA) or positron-emitting (gallium 68-5HT-DOTAGA) substrates for MRI and PET/CT imaging, respectively. EGFR expression was confirmed by quantitative reverse transcriptase polymerase chain reaction and immunohistochemical analyses to compare with image findings. Results After surgical intraarterial delivery of TNBC cells, rats developed tumors that diverged into either rapidly growing osteolytic or slow-growing nonosteolytic tumors. Both tumor types showed receptor-specific initial MRI signal enhancement (contrast-to-noise ratio) that was three to six times higher than that of normal bone marrow (29.4 vs 4.9; P < .01). Micro PET/CT imaging of EGFR expression demonstrated a high level of heterogeneity with regional uptake of the tracer, which corresponded to region-of-interest MRI signal intensity elevation (121.1 vs 93.3; P < .001). Analysis of metastases with corroboration of imaging results showed high levels of EGFR protein and messenger RNA, or mRNA, expression in the invasive tumor. Conclusion Convergence of multimodal molecular receptor imaging enabled comprehensive assessment of EGFR overexpression in an orthotopic model of TNBC metastasis. Keywords: Animal Studies, Molecular Imaging-Cancer, MR-Contrast Agent, Radionuclide Studies, Skeletal-Appendicular, Metastases Supplemental material is available for this article. © RSNA, 2021.

Synthesis, ADMET predictions, molecular docking studies, and in-vitro anticancer activity of some benzoxazines against A549 human lung cancer cells.

This study aims to synthesize a series of benzoxazines (1-5) to be examined as an epidermal growth factor receptor (EGFR) inhibitor by in-silico study. The overexpression of EGFR causes the growth of normal lung cells to become uncontrollable, which may lead to cancer formation. We also conducted the absorption, distribution, metabolism, excretions and toxicity (ADMET) properties evaluation and also examined in vitro anticancer assay on human lung cancer cells line, which is A549. Benzoxazines (1-5) were synthesized by reacting anthranilic acid and benzoyl chlorides. The structures of the compounds were determined with 1H, 13C-NMR, HRMS, UV and FT-IR spectrometric methods. Prediction of ADMET was using online pkCSM, and the molecular docking studies were using MVD with EGFR-TKIs as the target (PDB ID: 1M17). In vitro assay of anticancer activity was performed by MTT assay. Compounds 1-5 were successfully synthesized in good yields (71-84%). The ADMET prediction showed that benzoxazines are able to be absorbed through GIT, metabolized by CYP 450, and not hepatotoxic. The title compounds have a greater Moldock Score than Erlotinib, and 3 has the highest activity against A549 compared with other benzoxazines, IC50=36.6μg/mL. Compound (3) more active as anticancer against Human cancer cells line compared with other benzoxazines.

Triple-Negative Metaplastic Breast Carcinoma: Association of Epidermal Growth Factor Receptor Expression With Prognostic Parameters and Clinical Outcome.

IntroductionMetaplastic breast carcinoma (MBC) is one of the rare special subtypes of breast carcinoma associated with poor prognostic features compared with invasive ductal carcinoma. Moreover, therapeutic options are limited in MBC owing to frequent triple-negative profiles of these tumors. Epidermal growth factor receptor (EGFR) is a proto-oncogene that is overexpressed in many human cancers, and is a potential therapeutic target. Therefore, in this study, we evaluated the expression of EGFR in MBC by immunohistochemistry, and its association with clinicopathological and prognostic parameters.MethodsWe conducted a retrospective observational study in the Department of Histopathology at Liaquat National Hospital and Medical College, Pakistan, over a period of seven years. A total of 61 cases with a histopathological diagnosis of MBC were included in the study. All slides were reviewed by histopathologists for diagnostic confirmation. Histopathological parameters, such as tumor size, grade, and nodal metastasis, were recorded. The representative tissue blocks were also retrieved and immunohistochemical studies were performed for cytokeratin 5/6 (CK5/6), Ki67, and EGFR.ResultsThe mean age of the patients was 44.48 ± 13.01 years. The mean tumor size was 5.72 ± 2.72 cm, with most of the cases belonging to tumor (T)-stage T3. Axillary metastasis was present in 57.4% cases, and the perinodal extension was present in 11.5% cases. Most tumors were grade III (85.2%), with a mean Ki67 index of 39.67% ± 20.38%. Most of the cases were nonbasal (83.6%), owing to the absent CK5/6 expression. Tumor recurrence was noted in 14.8% cases, with a median follow-up of 43 (13-83) months and median disease-free survival of 36 (12-60) months. Positive EGFR expression was noted in 52.5% cases. A significant association of EGFR expression was noted with tumor grade, mean Ki67 index, axillary metastasis, and nodal (N)-stage. Cases with positive EGFR expression were found to have higher grade (grade III), with higher Ki67 index, higher frequency of axillary metastasis, and higher N-stage. Moreover, cases with positive EGFR expression had lower disease-free survival compared to cases with negative EGFR expression.ConclusionWe found that a significant proportion of triple-negative MBC expressed EGFR. Moreover, EGFR overexpression was associated with poor pathological parameters and lower disease-free survival. Therefore, EGFR can be considered a potential prognostic biomarker and therapeutic target in triple-negative MBC; however, the correlation between gene amplification and protein overexpression is required to better uncover the role of EGFR as a therapeutic target.

The role of PKA/PP2B-mediated Drp1 phosphorylation and the subsequent EGFR inhibition in Cr(VI)-induced premature senescence

In recent years, frequent hexavalent chromium [Cr(VI)] pollution incidents have severely damaged the ecology and endangered the public health. It is well known that cell senescence could promote the carcinogenesis, thus the related research on the occurrence of premature senescence is of great significance to the elucidation of the carcinogenic mechanism of Cr(VI). We previously confirmed that long-term low-dose Cr(VI) exposure induced premature senescence, but the key molecular events that determine the occurrence of premature senescence are still unclear. In the present study, we found that Cr(VI) induced phosphorylation of dynamin-relatedprotein 1 (Drp1)-S637 site in premature senescent cells, which was accompanied with the decrease of mitochondrial fission. We also demonstrated that the phosphorylation status of Drp1-S637 after Cr(VI) exposure was related to the antagonism of PKA/PP2B, and continuous dephosphorylation of Drp1-S637 attenuated premature senescence caused by Cr(VI). The epidermal growth factor receptor (EGFR) overexpression significantly alleviated the occurrence of premature senescence, and the expressions of EFGR and its downstream molecules were related to the phosphorylation status of Drp1-S637. In brief, we revealed the role of PKA/PP2B-mediated Drp1 phosphorylation and the subsequent EGFR inhibition in Cr(VI)-induced premature senescence. This study is the first time to link the phosphorylation of Drp1 with Cr(VI)-induced premature senescence, in order to find the key molecular events that determine the occurrence of premature senescence and demonstrate the molecular mechanism of abnormal elongated mitochondria formation in the senescence process. The significance of this study is to explore the carcinogenesis of Cr(VI) and provide new ideas and strategies for the targeted treatment of Cr(VI)-related cancers.

Monitoring Receptor Heterodimerization along Intracellular Trafficking Pathways using Anti‐HER2 Therapeutic Antibodies

Overexpression of Human EGF Receptor 2 (HER2) in cancer is a marker of aggressive metastatic disease and poor prognosis. Anti-HER2 monoclonal antibody trastuzumab (TZM) has been successfully used in the clinic over the last decades. However, a large fraction of eligible patients display resistance to this therapy. Deeper investigation of TZM-HER2 binding, internalization and trafficking/degradation in cancer cells may provide some crucial answers. Forster resonance energy transfer Fluorescence lifetime microscopy (FRET-FLIM) offers a unique approach to monitor TZM-HER2 binding via the reduction of donor fluorophore lifetime. Thus, FRET-FLIM provides an efficient method to quantify ligand-receptor binding and internalization in cancer cells with the additional benefit of sensing intracellular microenvironment heterogeneity such as modulation of endocytic trafficking upon drug treatment. In this study, we report quantification of binding of NIR-labeled therapeutic antibodies FRET pairs to their respective receptors, e.g. HER2 and/or HER1, in AU565 breast cancer cells in various combinations, i.e. anti-HER1 cetuximab donor – cetuximab acceptor vs. cetuximab donor - TZM acceptor, to assess the dynamics of HER receptor homo and heterodimerization behavior. We also monitor FRET FLIM events along the intracellular trafficking of these anti-HER2 and anti-HER1 probes. Our data indicate that in the presence of TZM, HER1 as well as HER3 receptors localization is shifted towards plasma membrane. Furthermore, the distribution pattern of fluorescence lifetime during endocytic trafficking differs when comparing “homo” vs “hetero FRET” pairs. These results suggest that HER2 dimerization pattern can switch towards hetero- and oligomerization during TZM treatment which may result in modulation of oncogenic signaling. In parallel, Western blotting and immunofluorescent analysis of AU565 cells strongly indicate that 24h TZM treatment substantially upregulate HER3 and pHER2 levels both in 2D and 3D (spheroids) models. Together, these data imply that in cultured breast cancer models, short-term TZM treatment may inadvertently increase oncogenic fitness probably as a result of adaptation to HER2 - TZM binding.

EGFR Overexpression and Sequence Analysis of KRAS, BRAF, and EGFR Mutation Hot Spots in Canine Intestinal Adenocarcinoma.

Epidermal growth factor receptor (EGFR) is overexpressed in many human colorectal cancers and anti-EGFR agents are employed as immunotherapies. However, KRAS, EGFR, and BRAF gene mutations can influence the activity of the anti-EGFR agents. We evaluated EGFR expression at protein and mRNA levels in canine intestinal adenocarcinomas using immunohistochemistry (IHC) and RNA in situ hybridization (RNA-ISH). We also investigated the mutation status of EGFR, KRAS, and BRAF to aid the development of anti-EGFR agents for canine intestinal adenocarcinoma. EGFR expression was highest in adenocarcinoma, followed by intramucosal neoplasia (adenoma and in situ carcinoma), and nonneoplastic canine intestinal tissue, at both protein (P = .000) and mRNA (P = .005) levels. The EGFR, KRAS, and BRAF genes showed wild-type sequences at the mutation hot spots in all 13 specimens. Thus, EGFR might serve as a promising diagnostic marker in canine intestinal adenocarcinoma, and further studies would be needed to develop EGFR-targeted anticancer therapies.

MiR-338-5p Inhibits EGF-Induced EMT in Pancreatic Cancer Cells by Targeting EGFR/ERK Signaling.

The epidermal growth factor (EGF) pathway plays critical roles during cancer cell epithelial-mesenchymal transition (EMT) process and metastasis. Epidermal growth factor receptor (EGFR), as one of the important receptors of EGF, undergoes autophosphorylation with the stimulation of EGF and activates MAPK/ERK, PI3K/Akt/mTOR, and other pathways. Here, we identified EGFR was a target of miR-338-5p. Upon EGF treatment, overexpression of miR-338-5p not only downregulated EGFR expression and inhibited MAPK/ERK signaling, but also inhibited EMT and metastasis process of pancreatic cancer (PC) cells. In the clinical pathological analysis, miR-338-5p was significantly down-regulated in 44 pairs PC tissues and its expression was negatively associated with lymph node metastasis and AJCC stage. Furthermore, Overexpression of EGFR partially reversed the protective effect of miR-338-5p overexpression on EGF-mediated migration and invasion in PC cells. Taken together, miR-338-5p controls EGF-mediated EMT and metastasis in PC cells by targeting EGFR/ERK pathways. Here, we hope to provide new insights into the molecular mechanisms of pancreatic cancer, and may help facilitating development of EGFR-based therapies for human cancer.

Evaluation of effect of epidermal growth factor receptor and vascular endothelial growth factor overexpression in survival of patients with glioblastoma multiforme

Background. In the central nervous system, glioblastoma multiforme (GBM) is one of the most important neoplasms in adults. Amplification of EGFR and VEGF genes is common in GBM. However, the role of overexpression of EGFR and VEGF in survival of patients with GBM has been a contentious issue. Therefore, we performed the present study to assess the survival rate of patients with EGFR and VEGF overexpression. Materials and methods. Resected samples of GBM patients were evaluated by immunohistochemistry for overexpression of VEGF and EGFR. The patients were followed up for a year. Results. The mean±sd of age of patients was 56.2±13.1 years. The majority of the patients were male (65.9%). Most of the patients had primary GBM (67%), notwithstanding 33% of the patients with secondary GBM. Moreover, 19.2% and 49.5% of the samples were VEGF-positive and EGFR-positive, respectively. Overall 6, 12-, and 18-month survival rates were shown to be 61.5±5.1%, 17.6±4%, and 4.4±2.1%, respectively. There was a significant difference between the mean±se survival rate in VEGF-negative patients (12±1.9 months) VEGF-positive patients (7.8±0.5 months) (P=0.045). Conclusions. We found an association between VEGF and EGFR over-expression and the survival rate of GBM patients. The VEGF overexpression was significantly associated with the overall survival rate of the GBM patients, but failed to have a prognostic value for their mortality rate. However, EGFR was a predictor of overall survival rate and mortality of GBM patients. Moreover, VEGF overexertion has a stronger association with survival rate in GBM, compared to EGFR overexpression.

Bio Functional Evaluation of EGFR Expression as a Prognostic Indicator in Oral Squamous Cell Carcinoma and a Recommendation for Personalized Targeted Therapy with Anti EGFR Inhibitors

Background: Carcinoma is a complex, multifactorial and a devastating disease. Understanding the molecularchanges that leads to disease enables one to develop strategies to prevent, provide an early diagnosis andserve as targets for therapy. Epidermal Growth Factor Receptor (EGFR), a 170-kDa cell-surface proteinis a tyrosine kinase receptor from the ErbB family and is involved in many biological processes thataffect tumour development, growth progression, differentiation, inhibition of apoptosis and developmentof metastasis. Methods: Study included 54 cases of oral squamous cell carcinomas. EGFR expression byimmunohistochemistry has been studied, correlated with clinical parameters, known prognostic factors andpatient survival to note its significance.Conclusion: Head and Neck Squamous Cell Carcinoma (HNSCC) with or without regional lymph nodemetastases, are challenging to treat effectively. The prognosis for the patients with advanced stage of thedisease still remains poor. The correlation of EGFR overexpression with tumour size, grade, stage andsurvival suggests that EGFR expression can be considered as having prognostic significance and is apotential target for therapy with EGFR inhibitors in HNSCC. Further studies are required to assure theviability of EGFR levels in saliva as non-invasive prognostic marker and also as an indicator of recurrence.

Preclinical Evaluation of the Association of the Cyclin-Dependent Kinase 4/6 Inhibitor, Ribociclib, and Cetuximab in Squamous Cell Carcinoma of the Head and Neck.

Simple SummaryWe previously showed that ribociclib induces cell cycle arrest in some human papillomavirus (HPV)-negative squamous cell carcinomas of the head and neck (SCCHN) models. However, in vivo, ribociclib has only a cytostatic effect, suggesting that its activity needs to be optimized in combination with other treatments. We investigated the activity of ribociclib in combination with cetuximab in several HPV-negative SCCHN patient-derived tumor xenograft (PDTX) models. We found that the combination of cetuximab and ribociclib was not significantly more active than cetuximab monotherapy. In addition, our observations also suggest that the combination of cetuximab with a cyclin-dependent kinase (CDK) 4/6 inhibitor may reduce the activity of the CDK4/6 inhibitor in some cetuximab-resistant models. Our work has significant clinical implications since combinations of anti-epidermal growth factor receptor (EGFR) therapy and CDK4/6 inhibitors are currently being investigated in clinical trials.Epidermal growth factor receptor (EGFR) overexpression is observed in 90% of human papillomavirus (HPV)-negative squamous cell carcinomas of the head and neck (SCCHN). Cell cycle pathway impairments resulting in cyclin-dependent kinase (CDK) 4 and 6 activation, are frequently observed in SCCHN. We investigated the efficacy of ribociclib, a CDK4/6 inhibitor, in combination with cetuximab, a monoclonal antibody targeting the EGFR, in HPV-negative SCCHN patient-derived tumor xenograft (PDTX) models. The combination of cetuximab and ribociclib was not significantly more active than cetuximab monotherapy in all models investigated. In addition, the combination of cetuximab and ribociclib was less active than ribociclib monotherapy in the cetuximab-resistant PDTX models. In these models, a significant downregulation of the retinoblastoma (Rb) protein was observed in cetuximab-treated mice. We also observed Rb downregulation in the SCCHN cell lines chronically exposed and resistant to cetuximab. In addition, Rb downregulation induced interleukin 6 (Il-6) secretion and the Janus kinase family member/signal transducer and activator of transcription (JAK/STAT) pathway activation that might be implicated in the cetuximab resistance of these cell lines. To conclude, cetuximab is not an appropriate partner for ribociclib in cetuximab-resistant SCCHN models. Our work has significant clinical implications since the combination of anti-EGFR therapy with CDK4/6 inhibitors is currently being investigated in clinical trials.