scholarly journals Aptamers selected against the unglycosylated EGFRvIII ectodomain and delivered intracellularly reduce membrane-bound EGFRvIII and induce apoptosis

2009 ◽  
Vol 390 (2) ◽  
pp. 137-144 ◽  
Author(s):  
Yingmiao Liu ◽  
Chien-Tsun Kuan ◽  
Jing Mi ◽  
Xiuwu Zhang ◽  
Bryan M. Clary ◽  
...  
Keyword(s):  
Growth Factor Receptor ◽  
Rna Aptamers ◽  
Normal Brain ◽  
Post Translational Modification ◽  
Expression And Purification ◽  
Post Translational Modifications ◽  
Protein Expression And Purification ◽  
Epidermal Growth ◽  
Membrane Bound

Abstract Epidermal growth factor receptor variant III (EGFRvIII) is a glycoprotein uniquely expressed in glioblastoma, but not in normal brain tissues. To develop targeted therapies for brain tumors, we selected RNA aptamers against the histidine-tagged EGFRvIII ectodomain, using an Escherichia coli system for protein expression and purification. Representative aptamer E21 has a dissociation constant (Kd) of 33×10-9 m, and exhibits high affinity and specificity for EGFRvIII in ELISA and surface plasmon resonance assays. However, selected aptamers cannot bind the same protein expressed from eukaryotic cells because glycosylation, a post-translational modification present only in eukaryotic systems, significantly alters the structure of the target protein. By transfecting EGFRvIII aptamers into cells, we find that membrane-bound, glycosylated EGFRvIII is reduced and the percentage of cells undergoing apoptosis is increased. We postulate that transfected aptamers can interact with newly synthesized EGFRvIII, disrupt proper glycosylation, and reduce the amount of mature EGFRvIII reaching the cell surface. Our work establishes the feasibility of disrupting protein post-translational modifications in situ with aptamers. This finding is useful for elucidating the function of proteins of interest with various modifications, as well as dissecting signal transduction pathways.

Not All Cases of Mammary Paget’s Disease are Cytokeratin-7 Positive: A Challenging Diagnosis!

2021 ◽  
pp. 106689692110029
Author(s):  
Kerschen Anja ◽  
Dano Hélène ◽  
Van Eeckhout Pascal ◽  
Marot Liliane ◽  
Van Bockstal Mieke
Keyword(s):  
Present Report ◽  
Paget’S Disease ◽  
Growth Factor Receptor ◽  
Punch Biopsy ◽  
Paget's Disease ◽  
Cytokeratin 7 ◽  
In Situ Carcinoma ◽  
Epidermal Growth ◽  
Mammary Paget’S Disease

Mammary Paget’s disease accounts for 1% to 3% of all breast tumors and manifests as a chronic eczematous lesion of the areolar skin. It can occur without any underlying neoplasia or can be present in association with an underlying invasive and/or in situ carcinoma of the breast. The present report describes a challenging nipple punch biopsy showing an infiltration of the lower third to two-thirds of the epidermis by large, ovoid, neoplastic cells. The morphology was consistent with mammary Paget's disease, although immunohistochemistry for cytokeratin-7 (CK7) was repeatedly negative. This resulted in an initial misdiagnosis and, subsequently, a delay in the patient's follow-up. Additional immunohistochemistry for GATA binding protein 3 (GATA3) and human epidermal growth factor receptor 2 (HER2), as well as a second opinion of a breast pathologist, resulted in the diagnosis of mammary Paget's disease. The aim of this article is to raise awareness among pathologists and prevent them from misdiagnosing CK7-negative Paget disease of the breast.

scholarly journals The Prognostic Impact of HER2 Genetic and Protein Expression in Pancreatic Carcinoma—HER2 Protein and Gene in Pancreatic Cancer

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 653
Author(s):  
Song-Hee Han ◽  
Ki Hyun Ryu ◽  
Ah-Young Kwon
Keyword(s):  
Protein Expression ◽  
Genetic Heterogeneity ◽  
Growth Factor Receptor ◽  
Ductal Adenocarcinoma ◽  
Prognostic Impact ◽  
Her2 Expression ◽  
Her2 Protein ◽  
Epidermal Growth ◽  
Her2 Heterogeneity

Pancreatic ductal adenocarcinoma (PDAC) is a lethal and clinically heterogeneous disease with a limited benefit from human epidermal growth factor receptor 2 (HER2)-targeted therapy. Recently, some studies have addressed the antitumoral effect of novel anti-HER2 drugs in HER2 low-expressing tumors. However, there have been few studies on the significance of low HER2 expression and genetic heterogeneity in PDAC. Using immunohistochemistry and dual-color silver-enhanced in situ hybridization based on the Trastuzumab for a gastric cancer scoring scheme, we evaluated HER2 protein expression, gene amplification, and genetic heterogeneity in three groups (HER2-neg, HER2-low, HER2-pos) of 55 patients. Among the 55 cases, 41.8% (23/55) showed HER2 expression of any intensity. HER2 amplification independent of HER2 expression was 25.5% (14/55). Patients in both these groups had a shorter overall survival than did patients in the HER2-neg group. HER2 genetic heterogeneity was identified in 37 (70.9%) of the 55 cases, mainly in HER2-neg and HER2-low groups. HER2 genetic heterogeneity significantly correlated with worse survival in the HER2-low and HER2-neg groups of PDAC. These findings support the hypothesis that low-level HER2 expression and heterogeneity have significant clinical implications in PDAC. HER2 heterogeneity might indicate the best strategies of combination therapies to prevent the development of subdominant clones with resistance potential.

Increased Likelihood of Mastectomy in Human Epidermal Growth Factor Receptor 2-positive Ductal Carcinoma In Situ

2014 ◽  
Vol 80 (10) ◽  
pp. 936-939 ◽  
Author(s):  
Anna Weiss ◽  
Vivi Tran ◽  
Jennifer Baker ◽  
Hasteh Farnaz ◽  
Anne M. Wallace ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Ductal Carcinoma In Situ ◽  
Carcinoma In Situ ◽  
Ductal Carcinoma ◽  
Growth Factor Receptor ◽  
Human Epidermal Growth Factor ◽  
Epidermal Growth

Patients with human epidermal growth factor receptor 2 (HER2neu)-positive breast invasive cancer are known to have larger, more aggressive tumors. Little research exists on the relationship between HER2neu status and extent of ductal carcinoma in situ (DCIS). A retrospective review of a single-institution database was performed for patients with DCIS between the years 2002 and 2011. A single blinded breast radiologist reviewed preoperative imaging. Pathology was reviewed for extent of DCIS. Primary outcome was mastectomy. Multivariate logistic regression was used to determine adjusted mastectomy risk. There were 166 cases, 34 HER2neu-positive. HER2neu receptor-positive patients had larger lesions on imaging: 4.0 versus 2.7 cm, by 2.9 versus 1.5 cm ( P = 0.0499 and 0.0182). HER2neu-positive patients with DCIS were more likely than HER2neu-negative to undergo mastectomy than lumpectomy (53 vs 28%, P = 0.006). Pathology revealed a trend toward larger lesions in HER2neu-positive patients (2.96 vs 2.22 cm, nonsignificant). Patients with HER2neu-positive disease were three times more likely to undergo mastectomy (odds ratio, 2.9; 95% confidence interval, 1.23 to 6.78). Patients with HER2neu-positive DCIS had greater extent of disease by imaging and were more likely to undergo mastectomy than HER2neu-negative. These findings will help surgeons counsel patients on surgical treatment.

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