scholarly journals CSIG-20. EFFECT OF TUMOR-TREATING FIELDS (TTFIELDS) ON EGFR PHOSPHORYLATION IN GBM CELL LINES

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi48-vi48
Author(s):  
Maria Luisa D’Angelo ◽  
Deborah Piffaretti ◽  
Floriana Burgio ◽  
Alessio Chiappini ◽  
Francesco Marchi ◽  
...  

Abstract Glioblastoma (GBM) is the most common high grade and most devastating brain tumor among adults. About 50% of GBM express EGFR (epidermal growth factor receptor) and from these another 50% the mutated form EGFRvIII which is associated with a more aggressive disease and poorer prognosis. We have previously shown that expression of different status of EGFR in GBM cell lines drives the 5-ALA induced fluorescence downstream by influencing the rate-limiting enzyme heme oxygenase-1 (HO-1) probably via PI3K/Akt signalling. We demonstrated that 5-ALA-induced protoporphyrin IX (PpIX) fluorescence is pharmacologically influenced by adding different drugs such as deferoxamine (DFO) and tin-protoporphyrin (SnPP), which are an iron chelator of Fe2+ and an inhibitor of HO-1 respectively, or genistein that promotes PpIX accumulation via functional repression of ABCG2 (ABC transporter G2). Our aim is to increase these pharmacological effects on PpIX fluorescence using tumor-treating fields (TTFields). TTFields, a new therapeutic technology for treating newly diagnosed or recurrent GBM, is able to suppress the growth of cancer cells destabilising microtubule elongation and increasing membrane permeability. Interestingly, TTFields, like as other destabilising drugs and compounds, is able to inhibit the phosphorylation of EGFR and subsequent downregulation of EGFR-induced signalling acting for example on the mechanism that regulate the HO-1 activity. Here, we investigate the effects of TTFields on glioma cells, with different EGFR status and consequently different PpIX fluorescence. Exposure to TTFields during or after pharmacological treatments may represent a novel strategy to block or diminish the phosphorylation of EGFR to ameliorate the visualization of PpIX fluorescence in patients where it is not enough to ensure a safe and precise removal of the tumor bulk. In fact, if a combination of TTFields and drug treatment should give the desired results, this strategy could be applied on patients before being subjected to surgical resection.

2019 ◽  
Vol 8 (12) ◽  
pp. 2214 ◽  
Author(s):  
Carl Fisher ◽  
Girgis Obaid ◽  
Carolyn Niu ◽  
Warren Foltz ◽  
Alyssa Goldstein ◽  
...  

Background: Malignant gliomas are highly invasive and extremely difficult to treat tumours with poor prognosis and outcomes. Photodynamic therapy (PDT), mediated by Gleolan®, has been studied previously with partial success in treating these tumours and extending lifetime. We aim to determine whether combining PDT using ALA-protoporphyrin IX (PpIX) with a liposomal formulation of the clinical epidermal growth factor receptor (EGFR) inhibitor, lapatinib, would increase the anti-tumour PDT efficacy. Methods: Lapatinib was given in vitro and in vivo 24 h prior to PDT and for 3–5 days following PDT to elicit whether the combination provided any benefits to PDT therapy. Live-cell imaging, in vitro PDT, and in vivo studies were performed to elucidate the effect lapatinib had on PDT for a variety of glioma cell lines and as well as GSC-30 neurospheres in vivo. Results: PDT combined with lapatinib led to a significant increase in PpIX accumulation, and reductions in the LD50 of PpIX mediated PDT in two EGFR-driven cell lines, U87 and U87vIII, tested (p < 0.05). PDT + lapatinib elicited stronger MRI-quantified glioma responses following PDT for two human glioma-derived tumours (U87 and GSC-30) in vivo (p < 0.05). Furthermore, PDT leads to enhanced survival in rats following treatment with lapatinib compared to lapatinib alone and PDT alone (p < 0.05). Conclusions: As lapatinib is approved for other oncological indications, a realization of its potential combination with PDT and in fluorescence-guided resection could be readily tested clinically. Furthermore, as its use would only be in acute settings, long-term resistance should not pose an issue as compared to its use as monotherapy.


2020 ◽  
Vol 20 (18) ◽  
pp. 1628-1639
Author(s):  
Sergi Gómez-Ganau ◽  
Josefa Castillo ◽  
Andrés Cervantes ◽  
Jesus Vicente de Julián-Ortiz ◽  
Rafael Gozalbes

Background: The Epidermal Growth Factor Receptor (EGFR) is a transmembrane protein that acts as a receptor of extracellular protein ligands of the epidermal growth factor (EGF/ErbB) family. It has been shown that EGFR is overexpressed by many tumours and correlates with poor prognosis. Therefore, EGFR can be considered as a very interesting therapeutic target for the treatment of a large variety of cancers such as lung, ovarian, endometrial, gastric, bladder and breast cancers, cervical adenocarcinoma, malignant melanoma and glioblastoma. Methods: We have followed a structure-based virtual screening (SBVS) procedure with a library composed of several commercial collections of chemicals (615,462 compounds in total) and the 3D structure of EGFR obtained from the Protein Data Bank (PDB code: 1M17). The docking results from this campaign were then ranked according to the theoretical binding affinity of these molecules to EGFR, and compared with the binding affinity of erlotinib, a well-known EGFR inhibitor. A total of 23 top-rated commercial compounds displaying potential binding affinities similar or even better than erlotinib were selected for experimental evaluation. In vitro assays in different cell lines were performed. A preliminary test was carried out with a simple and standard quick cell proliferation assay kit, and six compounds showed significant activity when compared to positive control. Then, viability and cell proliferation of these compounds were further tested using a protocol based on propidium iodide (PI) and flow cytometry in HCT116, Caco-2 and H358 cell lines. Results: The whole six compounds displayed good effects when compared with erlotinib at 30 μM. When reducing the concentration to 10μM, the activity of the 6 compounds depends on the cell line used: the six compounds showed inhibitory activity with HCT116, two compounds showed inhibition with Caco-2, and three compounds showed inhibitory effects with H358. At 2 μM, one compound showed inhibiting effects close to those from erlotinib. Conclusion: Therefore, these compounds could be considered as potential primary hits, acting as promising starting points to expand the therapeutic options against a wide range of cancers.


2006 ◽  
Vol 13 (4) ◽  
pp. 1173-1183 ◽  
Author(s):  
Michael W Yeh ◽  
Jean-Philippe Rougier ◽  
Jin-Woo Park ◽  
Quan-Yang Duh ◽  
Mariwil Wong ◽  
...  

Mechanisms of invasion in thyroid cancer remain poorly understood. We hypothesized that signaling via the epidermal growth factor receptor (EGFR) stimulates thyroid cancer cell invasion by altering the expression and cleavage of matrix metalloproteinases (MMPs). Papillary and follicular carcinoma cell lines were treated with EGF, the EGFR tyrosine kinase inhibitor AG1478, and the MMP inhibitors GM-6001 and Col-3. Flow cytometry was used to detect EGFR. In vitro invasion assays, gelatin zymography, and quantitative reverse transcription-PCR were used to assess the changes in invasive behavior and MMP expression and activation. All cell lines were found to overexpress functional EGFR. EGF stimulated invasion by thyroid cancer cells up to sevenfold (P < 0.0001), a process that was antagonized completely by AG1478 and Col-3, partially by GM-6001, but not by the serine protease inhibitor aprotinin. EGF upregulated expression of MMP-9 (2.64- to 8.89-fold, P < 0.0001) and membrane type-1 MMP (MT1-MMP, 1.97- to 2.67-fold, P < 0.0001). This effect was blocked completely by AG1478 and partially by Col-3. The activation of MMP-2 paralleled MT1-MMP expression. We demonstrate that MMPs are critical effectors of invasion in the papillary and follicular thyroid cancer cell lines studied. Invasion is regulated by signaling through EGFR, an effect mediated by augmentation of gelatinase expression and activation. MMP inhibitors and growth factor antagonists may be effective tumoristatic agents for the treatment of aggressive thyroid carcinomas.


Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 682 ◽  
Author(s):  
Xinshan Deng ◽  
Xiaoyu Tan ◽  
Tiantian An ◽  
Qingqing Ma ◽  
Zhe Jin ◽  
...  

Based on the analysis of epidermal growth factor receptor (EGFR) complexes with gefitinib with molecular docking, the scaffold-hopping strategy, combination of the active substructures, and structural optimization of EGFR inhibitors, a novel series of benzo[4,5]imidazo[2,1-b]thiazole derivatives was designed, synthesized, and evaluated for antitumor activity in human cancer cell lines and cellular toxicity against human normal cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay and EGFR inhibitory activities in vitro. Some target compounds such as 2-(benzo[4,5]imidazo[2,1-b]thiazol-3-yl)-N-(2-hydroxyphenyl)acetamide (D04) and 2-(benzo[4,5]imidazo[2,1-b]thiazol-3-yl)-N-(naphthalen-1-yl)acetamide (D08) have shown significant antitumor activity against the EGFR high-expressed human cell line HeLa. All the target compounds showed hardly any antitumor activity against the EGFR low-expressed human cell line HepG2, and nearly no cellular toxicity against the human normal cell lines HL7702 and human umbilical vein endothelial cell lines (HUVEC). The inhibitory activities against EGFR kinase in vitro of the three target compounds were greatly consistent with the anti-proliferative activities. The preliminary structure–activity relationships of the target compounds were summarized. Conclusively, the novel benzo[4,5]imidazo[2,1-b]thiazole derivatives as novel potential EGFR inhibitors may be used as the potential lead compounds for the development of antitumor agents.


2019 ◽  
Vol 67 (7) ◽  
pp. 511-522 ◽  
Author(s):  
Marie C. Nyman ◽  
Anne B. Jokilammi ◽  
Pia C. Boström ◽  
Samu H. Kurki ◽  
Annele O. Sainio ◽  
...  

The extracellular matrix proteoglycan decorin is well-known for its oncosuppressive activity. Here, decorin expression was examined in human vulva carcinoma tissue samples and in primary and commercial cell lines representing this malignant disease. Furthermore, the effect of adenovirus-mediated decorin cDNA (Ad-DCN) transduction on the viability, proliferation, and the expression and activity of the epidermal growth factor receptor (ErbB/HER) family members of the cell lines were investigated. Using in situ hybridization and immunohistochemistry for decorin, it was demonstrated that malignant cells in human vulva carcinoma tissues lack decorin expression. This result was true independently on tumor stage, grade or human papillomavirus status. RT-qPCR analyses showed that the human vulva carcinoma cell lines used in this study were also negative for decorin expression. Transduction of the cell lines with Ad-DCN caused a marked reduction in cell viability, while the proliferation of the cells was not affected. Experiments examining potential mechanisms behind the oncosuppressive effect of Ad-DCN transduction revealed that ErbB2/HER2 expression and activity in carcinoma cells were markedly downregulated. In conclusion, the results of this study showed that human vulva carcinoma cells lack decorin expression, and that Ad-DCN transduction of these cells induces oncosuppressive activity in part via downregulation of ErbB2/HER2.


2016 ◽  
Vol 40 (6) ◽  
pp. 1303-1315 ◽  
Author(s):  
Shuang Li ◽  
Haiyang Zhang ◽  
Tao Ning ◽  
Xinyi Wang ◽  
Rui Liu ◽  
...  

Background: MicroRNAs (miRNAs) have been demonstrated to play a crucial role in tumorigenesis. Previous studies have shown that miR-520b/e acts as a tumor suppressor in several tumors. Other studies indicated that epidermal growth factor receptor (EGFR) is highly expressed in many tumors, and involved in the development of tumors, such as cell proliferation, migration, angiogenesis and apoptosis. However, the correlation of miRNAs and EGFR in gastric cancer (GC) has not been adequately investigated. Our aim was to explore the relationship. Methods: The expression levels of EGFR and miR-520b/e were examined by RT-PCR and Western blot. We also investigated the relationship between EGFR and miR-520b/e in GC cell lines by relevant experiments. Results: In this study, we found that miR-520b/e inhibits the protein expression of EGFR by directly binding with the 3'-untranslated region (3'-UTR). And it was shown that the down-regulation of miR-520b/e promotes cell proliferation and migration by negative regulation of the EGFR pathway, while over-expression of miR-520b/e inhibits these properties. In addition, the biological function of EGFR in GC cell lines was validated by silencing and over-expression assays respectively. Conclusions: Taken together, our results demonstrate that miR-520b/e acts as a tumor suppressor by regulating EGFR in GC, and provide a novel marker and insight for the potential therapeutic target of GC.


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