scholarly journals Lamellipodin-RICTOR Signaling Mediates Glioblastoma Cell Invasion and Radiosensitivity Downstream of EGFR

Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5337
Author(s):  
Stefanie Moritz ◽  
Matthias Krause ◽  
Jessica Schlatter ◽  
Nils Cordes ◽  
Anne Vehlow
Keyword(s):  
Mammalian Target Of Rapamycin ◽  
Unmet Need ◽  
Resistance Mechanism ◽  
Treatment Strategies ◽  
Growth Factor Receptor ◽  
Therapy Resistance ◽  
Tumor Type ◽  
Egfr Signaling ◽  
Glioblastoma Cells ◽  
Surface Receptors

Glioblastoma is a tumor type of unmet need despite the development of multimodal treatment strategies. The main factors contributing to the poor prognosis of glioblastoma patients are diverse genetic and epigenetic changes driving glioblastoma persistence and recurrence. Complemented are these factors by extracellular cues mediated through cell surface receptors, which further aid in fostering pro-invasion and pro-survival signaling contributing to glioblastoma therapy resistance. The underlying mechanisms conferring this therapy resistance are poorly understood. Here, we show that the cytoskeleton regulator Lamellipodin (Lpd) mediates invasiveness, proliferation and radiosensitivity of glioblastoma cells. Phosphoproteome analysis identified the epidermal growth factor receptor (EGFR) signaling axis commonly hyperactive in glioblastoma to depend on Lpd. Mechanistically, EGFR signaling together with an interaction between Lpd and the Rapamycin-insensitive companion of mammalian target of rapamycin (RICTOR) jointly regulate glioblastoma radiosensitivity. Collectively, our findings demonstrate an essential function of Lpd in the radiation response and invasiveness of glioblastoma cells. Thus, we uncover a novel Lpd-driven resistance mechanism, which adds an additional critical facet to the complex glioblastoma resistance network.

scholarly journals Updated Insights on EGFR Signaling Pathways in Glioma

2021 ◽  
Vol 22 (2) ◽  
pp. 587
Author(s):  
Alexandru Oprita ◽  
Stefania-Carina Baloi ◽  
Georgiana-Adeline Staicu ◽  
Oana Alexandru ◽  
Daniela Elise Tache ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Treatment Strategies ◽  
Growth Factor Receptor ◽  
Standard Of Care ◽  
Egfr Signaling ◽  
Current Standard ◽  
Egfr Amplification ◽  
Epidermal Growth ◽  
New Diagnosis ◽  
Clear Clinical Benefit

Nowadays, due to recent advances in molecular biology, the pathogenesis of glioblastoma is better understood. For the newly diagnosed, the current standard of care is represented by resection followed by radiotherapy and temozolomide administration, but because median overall survival remains poor, new diagnosis and treatment strategies are needed. Due to the quick progression, even with aggressive multimodal treatment, glioblastoma remains almost incurable. It is known that epidermal growth factor receptor (EGFR) amplification is a characteristic of the classical subtype of glioma. However, targeted therapies against this type of receptor have not yet shown a clear clinical benefit. Many factors contribute to resistance, such as ineffective blood–brain barrier penetration, heterogeneity, mutations, as well as compensatory signaling pathways. A better understanding of the EGFR signaling network, and its interrelations with other pathways, are essential to clarify the mechanisms of resistance and create better therapeutic agents.

scholarly journals Therapy-induced transdifferentiation promotes glioma growth independent of EGFR signaling

2020 ◽  
Author(s):  
Hwanhee Oh ◽  
Inah Hwang ◽  
Lingxiang Wu ◽  
Dongqing Cao ◽  
Jun Yao ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Malignant Gliomas ◽  
Growth Factor Receptor ◽  
Glioma Cells ◽  
Underlying Mechanism ◽  
Therapy Resistance ◽  
Small Population ◽  
Dominant Negative ◽  
Egfr Signaling ◽  
Glioma Growth

AbstractEpidermal growth factor receptor (EGFR) is frequently amplified, mutated and overexpressed in malignant gliomas. Yet the EGFR-targeted therapies have thus far produced only marginal clinical response, and the underlying mechanism remains poorly understood. Through analyses of an inducible oncogenic EGFR-driven glioma mouse model system, our current study reveals a small population of glioma cells that can evade therapy-initiated apoptosis and potentiate relapse development by adopting a mesenchymal-like phenotypic state that no longer depends on oncogenic EGFR signaling. Transcriptome analyses of proximal and distal treatment responses further identify TGFβ/YAP/Slug signaling cascade activation as major regulatory mechanism that promotes therapy-induced glioma mesenchymal lineage transdifferentiation. Following anti-EGFR treatment, the TGFβ secreted from the stressed glioma cells acts to promote YAP nuclear translocation and activation, which subsequently stimulates upregulation of the pro-mesenchymal transcriptional factor Slug and then glioma lineage transdifferentiation towards a stable therapy-refractory state. Blockade of this adaptive response through enforced dominant negative YAP expression significantly delayed anti-EGFR relapse and significantly prolonged animal survival. Together, our findings shed new insight into EGFR-targeted therapy resistance and suggest that combinatorial therapies of targeting both EGFR and mechanisms underlying glioma lineage transdifferentiation could ultimately lead to deeper and more durable responses.SignificanceThis study demonstrates that molecular reprogramming and lineage transdifferentiation underlie anti-EGFR therapy resistance and is clinically relevant to the development of new combinatorial targeting strategies against malignant gliomas carrying aberrant EGFR signaling.

Treatment Strategies in Metastatic Renal Cell Carcinoma

2010 ◽  
Vol 06 (02) ◽  
pp. 41
Author(s):  
Alain Ravaud ◽  
Jean Christophe Bernhard ◽  
Marine Gross-Goupil ◽  
◽  
◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Metastatic Renal Cell Carcinoma ◽  
Renal Cell ◽  
Mammalian Target Of Rapamycin ◽  
Treatment Strategies ◽  
Growth Factor Receptor ◽  
Clinical Effects ◽  
Improved Outcomes ◽  
Endothelial Growth Factor

Metastatic renal cell carcinoma (mRCC) is associated with a poor clinical outcome. Until recently, treatment recommendations were limited to immunotherapy and nephrectomy; however, an increased understanding of the molecular biology of RCC has led to the advent of targeted therapies directed against vascular endothelial growth factor/receptor (VEGF/VEGFR) or the mammalian target of rapamycin (mTOR) pathways, both major mediators of tumour growth and progression. These targeted agents have significantly improved outcomes in patients with mRCC, revolutionising treatment. These treatments have overlaps and important distinctions in terms of clinical effects, toxicity and patient populations in which they have been investigated. Concerns in terms of the appropriate sequencing of these agents, their combined use and their role in the context of nephrectomy have emerged as clinically relevant and are being actively investigated.

PDIA6 regulation of ADAM17 shedding activity and EGFR-mediated migration and invasion of glioblastoma cells

2016 ◽  
Vol 126 (6) ◽  
pp. 1829-1838 ◽  
Author(s):  
Tae-Wan Kim ◽  
Hyang-Hwa Ryu ◽  
Song-Yuan Li ◽  
Chun-Hao Li ◽  
Sa-Hoe Lim ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Matrix Metalloproteinase ◽  
Growth Factor Receptor ◽  
Matrix Metalloproteinase 2 ◽  
Migration And Invasion ◽  
Heparin Binding ◽  
Egfr Signaling ◽  
Glioblastoma Cells ◽  
Epidermal Growth

OBJECTIVEIn patients with glioblastoma, local invasion of tumor cells causes recurrence and shortens survival. The goal of this study was to determine whether protein disulfide isomerase (PDI) A6 regulates migration and invasion of glioblastoma cells and the associated factors.METHODSU87MG cells were treated with either PDIA6 or ADAM17 small interfering RNA (siRNA) fragments or with both types of siRNA fragments, and expression was confirmed by reverse transcription–polymerase chain reaction and Western blot. Migration and invasion were assessed using a wound-healing assay, a Matrigel assay, and an organotypic culture system. After the U87MG cells were treated with siRNAs and epidermal growth factor receptor (EGFR) inhibitors, the expression of matrix metalloproteinase–2 (MMP-2), membrane Type 1-matrix metalloproteinase (MT1-MMP), integrin, phosphorylated focal adhesion kinase (pFAK), and phosphorylated EGFR (pEGFR) was detected by Western blotting and zymography.RESULTSU87MG cell migration and invasion increased significantly after inhibition of PDIA6. The MMP-2 activation ratio and ADAM17 activity (as a sheddase of the proligand) increased, and expression of pEGFR, pFAK, integrin α5β3, and MT1-MMP was induced, compared with control levels. Furthermore, heparin-binding epidermal growth factor (EGFR signaling ligand) was highly expressed in PDIA6-knockdown cells. After siPDIA6-transfected U87MG cells were treated with EGFR signaling inhibitors, expression of pFAK, MMP-2, and MT1-MMP decreased and invasion decreased significantly. Simultaneous double-knockdown of PDIA6 and ADAM17 reduced pEGFR and pFAK expression, compared with control levels.CONCLUSIONSThe authors propose that inhibiting PDIA6 could transduce EGFR signaling by activating and inducing ADAM17 during migration and invasion of U87MG glioblastoma cells. The results of this study suggest that PDIA6 is an important component of EGFR-mediated migration and invasion of U87MG cells. This is the first report of the effects of PDIA6 on migration and invasion in glioblastoma.

scholarly journals Addressing resistance to immune checkpoint inhibitor therapy – an urgent unmet need

2021 ◽  
Author(s):  
Siwen Hu-Lieskovan ◽  
Gabriel G Malouf ◽  
Ira Jacobs ◽  
Jeffrey Chou ◽  
Li Liu ◽  
...  
Keyword(s):  
Immune Checkpoint ◽  
Checkpoint Inhibitors ◽  
Unmet Need ◽  
Treatment Strategies ◽  
Resistance Mechanisms ◽  
Patient Specific ◽  
Tumor Type ◽  
Patient Response ◽  
Effective Combination ◽  
Checkpoint Inhibitor Therapy

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of various cancers by reversing the immunosuppressive mechanisms employed by tumors to restore anticancer immunity. Although ICIs have demonstrated substantial clinical efficacy, patient response can vary in depth and duration, and many do not respond at all or eventually develop resistance. ICI resistance mechanisms can be tumor-intrinsic, related to the tumor microenvironment or patient-specific factors. Multiple resistance mechanisms may be present within one tumor subtype, or heterogeneity exists among patients with the same tumor type. Consequently, designing effective combination treatment strategies is challenging. This review will discuss ICI resistance mechanisms, and summarize findings from key preclinical and clinical trials of ICIs, to identify potential treatment strategies or pathways to overcome ICI resistance.

The Impact of Translational Research in Breast Cancer Care: Can we Improve the Therapeutic Scenario?

2018 ◽  
Vol 18 (6) ◽  
pp. 832-836
Author(s):  
Giuseppe Buono ◽  
Francesco Schettini ◽  
Francesco Perri ◽  
Grazia Arpino ◽  
Roberto Bianco ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Translational Research ◽  
Cell Biology ◽  
Cancer Biology ◽  
Hormone Receptors ◽  
Treatment Strategies ◽  
Growth Factor Receptor ◽  
Molecular Heterogeneity ◽  
Therapeutic Implications ◽  
The Impact

Traditionally, breast cancer (BC) is divided into different subtypes defined by immunohistochemistry (IHC) according to the expression of hormone receptors and overexpression/amplification of human epidermal growth factor receptor 2 (HER2), with crucial therapeutic implications. In the last few years, the definition of different BC molecular subgroups within the IHC-defined subtypes and the identification of the important role that molecular heterogeneity can play in tumor progression and treatment resistance have inspired the search for personalized therapeutic approaches. In this scenario, translational research represents a key strategy to apply knowledge from cancer biology to the clinical setting, through the study of all the tumors “omics”, including genomics, transcriptomics, proteomics, epigenomics, and metabolomics. Importantly, the introduction of new high-throughput technologies, such as next generation sequencing (NGS) for the study of cancer genome and transcriptome, greatly amplifies the potential and the applications of translational research in the oncology field. Moreover, the introduction of new experimental approaches, such as liquid biopsy, as well as new-concept clinical trials, such as biomarker-driven adaptive studies, may represent a turning point for BC translational research. </P><P> It is likely that translational research will have in the near future a significant impact on BC care, especially by giving us the possibility to dissect the complexity of tumor cell biology and develop new personalized treatment strategies.

scholarly journals Emerging Targeted Therapies for HER2 Positive Gastric Cancer That Can Overcome Trastuzumab Resistance

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 400 ◽  
Author(s):  
Seiichiro Mitani ◽  
Hisato Kawakami
Keyword(s):  
Gastroesophageal Junction ◽  
Treatment Strategies ◽  
Growth Factor Receptor ◽  
Trastuzumab Resistance ◽  
Her2 Positive ◽  
Drug Conjugates ◽  
Gastroesophageal Junction Cancer ◽  
Development Of Resistance ◽  
Epidermal Growth ◽  
Antibody Drug

Trastuzumab, a monoclonal antibody to human epidermal growth factor receptor 2 (HER2), has improved survival in patients with HER2-positive advanced gastric or gastroesophageal junction cancer (AGC). The inevitable development of resistance to trastuzumab remains a problem, however, with several treatment strategies that have proven effective in breast cancer having failed to show clinical benefit in AGC. In this review, we summarize the mechanisms underlying resistance to HER2-targeted therapy and outline past and current challenges in the treatment of HER2-positive AGC refractory to trastuzumab. We further describe novel agents such as HER2 antibody–drug conjugates that are under development and have shown promising antitumor activity in early studies.

scholarly journals Molecular Subtypes and Precision Oncology in Intrahepatic Cholangiocarcinoma

2021 ◽  
Vol 10 (13) ◽  
pp. 2803
Author(s):  
Carolin Czauderna ◽  
Martha M. Kirstein ◽  
Hauke C. Tews ◽  
Arndt Vogel ◽  
Jens U. Marquardt
Keyword(s):  
Clinical Care ◽  
Treatment Options ◽  
Treatment Strategies ◽  
Specific Treatment ◽  
Growth Factor Receptor ◽  
Treatment Modalities ◽  
Precision Oncology ◽  
Recurrence Rates ◽  
Isocitrate Dehydrogenase 1 ◽  
Liver Cancers

Cholangiocarcinomas (CCAs) are the second-most common primary liver cancers. CCAs represent a group of highly heterogeneous tumors classified based on anatomical localization into intra- (iCCA) and extrahepatic CCA (eCCA). In contrast to eCCA, the incidence of iCCA is increasing worldwide. Curative treatment strategies for all CCAs involve oncological resection followed by adjuvant chemotherapy in early stages, whereas chemotherapy is administered at advanced stages of disease. Due to late diagnosis, high recurrence rates, and limited treatment options, the prognosis of patients remains poor. Comprehensive molecular characterization has further revealed considerable heterogeneity and distinct prognostic and therapeutic traits for iCCA and eCCA, indicating that specific treatment modalities are required for different subclasses. Several druggable alterations and oncogenic drivers such as fibroblast growth factor receptor 2 gene fusions and hotspot mutations in isocitrate dehydrogenase 1 and 2 mutations have been identified. Specific inhibitors have demonstrated striking antitumor activity in affected subgroups of patients in phase II and III clinical trials. Thus, improved understanding of the molecular complexity has paved the way for precision oncological approaches. Here, we outline current advances in targeted treatments and immunotherapeutic approaches. In addition, we delineate future perspectives for different molecular subclasses that will improve the clinical care of iCCA patients.

scholarly journals Honokiol Prevents Non-Alcoholic Steatohepatitis-Induced Liver Cancer via EGFR Degradation through the Glucocorticoid Receptor—MIG6 Axis

Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1515
Author(s):  
Keiichiro Okuda ◽  
Atsushi Umemura ◽  
Shiori Umemura ◽  
Seita Kataoka ◽  
Hiroyoshi Taketani ◽  
...  
Keyword(s):  
Mouse Model ◽  
Glucocorticoid Receptor ◽  
Nuclear Translocation ◽  
Growth Factor Receptor ◽  
Public Health Problem ◽  
Egfr Signaling ◽  
Alcoholic Steatohepatitis ◽  
Genetic Mouse Model ◽  
Treatment And Prevention ◽  
Egfr Expression

Non-alcoholic steatohepatitis (NASH) has become a serious public health problem associated with metabolic syndrome. The mechanisms by which NASH induces hepatocellular carcinoma (HCC) remain unknown. There are no approved drugs for treating NASH or preventing NASH-induced HCC. We used a genetic mouse model in which HCC was induced via high-fat diet feeding. This mouse model strongly resembles human NASH-induced HCC. The natural product honokiol (HNK) was tested for its preventative effects against NASH progression to HCC. Then, to clarify the mechanisms underlying HCC development, human HCC cells were treated with HNK. Human clinical specimens were also analyzed to explore this study’s clinical relevance. We found that epidermal growth factor receptor (EGFR) signaling was hyperactivated in the livers of mice with NASH and human HCC specimens. Inhibition of EGFR signaling by HNK drastically attenuated HCC development in the mouse model. Mechanistically, HNK accelerated the nuclear translocation of glucocorticoid receptor (GR) and promoted mitogen-inducible gene 6 (MIG6)/ERBB receptor feedback inhibitor 1 (ERRFI1) expression, leading to EGFR degradation and thereby resulting in robust tumor suppression. In human samples, EGFR-positive HCC tissues and their corresponding non-tumor tissues exhibited decreased ERRFI1 mRNA expression. Additionally, GR-positive non-tumor liver tissues displayed lower EGFR expression. Livers from patients with advanced NASH exhibited decreased ERRFI1 expression. EGFR degradation or inactivation represents a novel approach for NASH–HCC treatment and prevention, and the GR–MIG6 axis is a newly defined target that can be activated by HNK and related compounds.

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