Epidermal growth factor stimulates vascular endothelial growth factor production by human malignant glioma cells: a model of glioblastoma multiforme pathophysiology

Distinct molecular targets of ProEGCG from EGCG and superior inhibition of angiogenesis signaling pathways for treatment of endometriosis

Endometriosis is a common chronic gynecological disease with endometrial cell implantation outside the uterus. Angiogenesis is a major pathophysiology in endometriosis. Our previous studies have demonstrated that the prodrug of epigallocatechin gallate (ProEGCG) exhibits superior anti-endometriotic and anti-angiogenic effects compared to epigallocatechin gallate (EGCG). However, their direct binding targets and underlying mechanisms for the differential effects remain unknown. In this study, we demonstrated that oral ProEGCG can be effective in preventing and treating endometriosis. Additionally, 1D and 2D Proteome Integral Solubility Alteration assay-based chemical proteomics identified metadherin (MTDH) and PX domain containing serine/threonine kinase-like (PXK) as novel binding targets of EGCG and ProEGCG, respectively. Computational simulation and BioLayer interferometry were used to confirm their binding affinity. Our results showed that MTDH-EGCG inhibited protein kinase B (Akt)-mediated angiogenesis, while PXK-ProEGCG inhibited epidermal growth factor (EGF)-mediated angiogenesis via the EGF/hypoxia-inducible factor (HIF-1a)/vascular endothelial growth factor (VEGF) pathway. In vitro and in vivo knockdown assays and microvascular network imaging further confirmed the involvement of these signaling pathways. Moreover, our study demonstrated that ProEGCG has superior therapeutic effects than EGCG by targeting distinct signal transduction pathways and may act as a novel antiangiogenic therapy for endometriosis.

Disease specific urinary biomarkers in the central nervous system

Urinary biomarkers can diagnose and monitor pathophysiologic conditions in the central nervous system (CNS). However, focus is often on single diseases, with limited data on discriminatory capability of this approach in a general setting. Here, we demonstrate that different classes of CNS disease exhibit distinct biomarker patterns, evidence of disease-specific "fingerprinting." Urine from 218 patients with pathology-confirmed tumors or cerebrovascular disease, controls (n = 33) were collected. ELISA and/or bead-based multiplexing quantified levels of 21 putative urinary biomarkers. Analysis identified biomarkers capable of distinguishing each disease from controls and other diseases. Mann-Whitney U tests identified biomarkers with differential expression between disease types and controls (P ≤ 0.001). Subsequent receiver-operating characteristic (ROC) analyses revealed distinguishing biomarkers with high sensitivity and specificity. Areas under the curve (AUCs) ranged 0.8563-1.000 (P values ≤ 0.0003), sensitivities ranged 80.00-100.00%, and specificities ranged 80.95-100.00%. These data demonstrate proof-of-principle evidence that disease-specific urinary biomarker signatures exist. In contrast to non-specific responses to ischemia or injury, these results suggest that urinary biomarkers accurately reflect unique biological processes distinct to different diseases. This work can be used to generate disease-specific panels for enhancing diagnosis, assisting less-invasive follow-up and herald utility by revealing putative disease-specific therapeutic targets.

Dynamic contrast-enhanced MRI radiomics model predicts epidermal growth factor receptor amplification in glioblastoma, IDH-wildtype

PURPOSE

To develop and validate a dynamic contrast-enhanced (DCE) MRI-based radiomics model to predict epidermal growth factor receptor (EGFR) amplification in patients with glioblastoma, isocitrate dehydrogenase (IDH) wildtype.

METHODS

Patients with pathologically confirmed glioblastoma, IDH wildtype, from January 2015 to December 2020, with an EGFR amplification status, were included. Patients who did not undergo DCE or conventional brain MRI were excluded. Patients were categorized into training and test sets by a ratio of 7:3. DCE MRI data were used to generate volume transfer constant (Ktrans) and extracellular volume fraction (Ve) maps. Ktrans, Ve, and conventional MRI were then used to extract the radiomics features, from which the prediction models for EGFR amplification status were developed and validated.

RESULTS

A total of 190 patients (mean age, 59.9; male, 55.3%), divided into training (n = 133) and test (n = 57) sets, were enrolled. In the test set, the radiomics model using the Ktrans map exhibited the highest area under the receiver operating characteristic curve (AUROC), 0.80 (95% confidence interval [CI], 0.65-0.95). The AUROC for the Ve map-based and conventional MRI-based models were 0.74 (95% CI, 0.58-0.90) and 0.76 (95% CI, 0.61-0.91).

CONCLUSION

The DCE MRI-based radiomics model that predicts EGFR amplification in glioblastoma, IDH wildtype, was developed and validated. The MRI-based radiomics model using the Ktrans map has higher AUROC than conventional MRI.

Nomogram prediction for the risk of venous thromboembolism in patients with lung cancer

OBJECTIVE

The aim of this study was to establish a nomogram graph model to accurately predict the venous thromboembolism (VTE) risk probability in the general population with lung cancer.

METHODS

Based on data from patients with lung cancer in Chongqing University Cancer Hospital of China, the independent risk factors of VTE were identified by the logistic univariable and multivariable analysis and were integrated to construct a nomogram, which was validated internally. The predictive effectiveness of the nomogram was evaluated by the receiver operating characteristic curve (ROC) and calibration curve.

RESULTS

A total of 3398 lung cancer patients were included for analysis. The nomogram incorporated eleven independent VTE risk factors including karnofsky performance scale (KPS), stage of cancer, varicosity, chronic obstructive pulmonary disease (COPD), central venous catheter (CVC), albumin, prothrombin time (PT), leukocyte counts, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), dexamethasone, and bevacizumab. The C-index of the nomogram model was 0.843 and 0.791 in the training and validation cohort, respectively, demonstrating good discriminative power. The calibration plots of the nomogram revealed excellent agreement between the predicted and actual probabilities.

CONCLUSIONS

We established and validated a novel nomogram for predicting the risk of VTE in patients with lung cancer. The nomogram model could precisely estimate the VTE risk of individual lung cancer patients and identify high-risk patients who are in need of a specific anticoagulation treatment strategy.

Design, synthesis, cytotoxic activities, and molecular docking of chalcone hybrids bearing 8-hydroxyquinoline moiety with dual tubulin/EGFR kinase inhibition

The present study established thirteen novel 8-hydroxyquinoline/chalcone hybrids3a-mof hopeful anticancer activity. According to NCI screening and MTT assay results, compounds3d-3f, 3i,3k,and3ldisplayed potent growth inhibition on HCT116 and MCF7 cells compared to Staurosporine. Among these compounds,3eand3fshowed outstanding superior activity against HCT116 and MCF7 cells and better safety toward normal WI-38 cells than Staurosporine. The enzymatic assay revealed that3e,3d, and3ihad goodtubulin polymerization inhibition (IC₅₀ = 5.3, 8.6, and 8.05 µM, respectively) compared to the reference Combretastatin A4 (IC₅₀ = 2.15 µM). Moreover,3e,3l, and3fexhibited EGFR inhibition (IC₅₀ = 0.097, 0.154, and 0.334 µM, respectively) compared to Erlotinib (IC₅₀ = 0.056 µM). Compounds3eand3fwere investigated for their effects on the cell cycle, apoptosis induction, andwnt1/β-cateningene suppression. The apoptosis markers Bax, Bcl2, Casp3, Casp9, PARP1, and β-actin were detected by Western blot. In-silico molecular docking, physicochemical, and pharmacokinetic studies were implemented for the validation of dual mechanisms and other bioavailability standards. Hence, Compounds3eand3fare promising antiproliferative leads with tubulin polymerization and EGFR kinase inhibition.

Efficacy of osimertinib in epidermal growth factor receptor-mutated non-small-cell lung cancer patients with pleural effusion

Background

Osimertinib is a standard first-line treatment for advanced non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations. Although malignant pleural effusion (PE) is a common clinical problem in NSCLC, information about the efficacy of osimertinib in patients with PE is limited, especially regarding its efficacy in EGFR T790M-negative patients with PE remains unclear.

Methods

We retrospectively reviewed the medical records of patients with NSCLC harboring EGFR mutations who were treated with osimertinib in our institution between May 2016 and December 2020.

Results

A total of 63 patients with EGFR mutated NSCLC were treated with osimertinib; 33 (12 with PE) had no EGFR T790M mutation, while 30 (12 with PE) had EGFR T790M mutation. In EGFR T790M-negative NSCLC, the progression-free survival (PFS) of the patients with PE was comparable to that of the patients without PE (median PFS 19.8 vs. 19.8 months, p = 0.693). In EGFR T790M- positive NSCLC, the PFS and overall survival (OS) of the patients with PE were significantly shorter than those of the patients without PE (median PFS 16.8 vs. 8.3 months, p = 0.003; median OS 44.9 vs. 14.2 months, p = 0.007). In the multivariate analysis, the presence of PE was independently associated with shorter PFS and OS in EGFR T790M-positive NSCLC patients, but not EGFR T790M-negative patients.

Conclusions

These data suggest the efficacy of osimertinib may differ between EGFR T790M-positive and -negative NSCLC patients with PE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09701-2.

Targeting Angiogenic Factors for the Treatment of Medulloblastoma

OPINION STATEMENT

Medulloblastoma (MB) is the most frequent pediatric brain tumor. Despite conventional therapy, MB patients have high mortality and morbidity rates mainly due to the incomplete understanding of the molecular and cellular processes involved in development of this cancer. Similar to other solid tumors, MB demonstrated high endothelial cell proliferation and angiogenic activity, wherein new blood vessels arise from the pre-existing vasculature, a process named angiogenesis. MB angiogenesis is considered a hallmark for MB development, progression, and metastasis emphasizing its potential target for antitumor therapy. However, angiogenesis is tightly regulated by a set of angiogenic factors making it a complex process to be targeted. Although agents targeting these factors and their receptors are early in development, the potential for their targeting may translate into improvement in the clinical care for MB patients. In this review, we focus on the most potent angiogenic factors and their corresponding receptors, highlighting their basic properties and expression in MB. We describe their contribution to MB tumorigenesis and angiogenesis and the potential therapeutic targeting of these factors.

Krill oil supplementation reduces the growth of CT-26 orthotopic tumours in Balb/c mice

Background

We have previously reported that the free fatty acid extract (FFAE) of krill oil (KO) significantly inhibits the proliferation and migration, and induces apoptosis of colorectal cancer (CRC) cells. This study aimed to investigate the in vivo efficacy of various doses of KO supplementation on the inhibition of CRC tumour growth, molecular markers of proliferation, angiogenesis, apoptosis, the epidermal growth factor receptor (EGFR) and its downstream molecular signalling.

Methods

Male Balb/c mice were randomly divided into four groups with five in each group. The control (untreated) group received standard chow diet; and other three groups received KO supplementation at 5%, 10%, and 15% of their daily dietary intake respectively for three weeks before and after the orthotopic implantation of CT-26 CRC cells in their caecum. The expression of cell proliferation marker Ki-67 and angiogenesis marker CD-31 were assessed by immunohistochemistry. The expression of EGFR, phosphorylated EGFR (pEGFR), protein kinase B (AKT), pAKT, extracellular signal-regulated kinase (ERK1/2), pERK1/2, cleaved caspase-7, cleaved poly (ADP-ribose) polymerase (PARP), and DNA/RNA damage were determined by western blot.

Results

KO supplementation reduced the CRC tumour growth in a dose-dependent manner; with 15% of KO being the most effective in reduction of tumour weight and volume (68.5% and 68.3% respectively, P < 0.001), inhibition of cell proliferation by 69.9% (P < 0.001) and microvessel density by 72.7% (P < 0.001). The suppressive effects of KO on EGFR and its downstream signalling, ERK1/2 and AKT, were consistent with our previous in vitro observations. Furthermore, KO exhibited pro-apoptotic effects on tumour cells as indicated by an increase in the expression of cleaved PARP by 3.9-fold and caspase-7 by 8.9-fold.

Conclusions

This study has demonstrated that KO supplementation reduces CRC tumour growth by inhibiting cancer cell proliferation and blood vessel formation and inducing apoptosis of tumour cells. These anti-cancer effects are associated with the downregulation of the EGFR signalling pathway and activation of caspase-7, PARP cleavage, and DNA/RNA damage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03521-4.

Glycomaterials to Investigate the Functional Role of Aberrant Glycosylation in Glioblastoma

Glioblastoma (GBM) is a stage IV astrocytoma that carries a dismal survival rate of ≈10 months postdiagnosis and treatment. The highly invasive capacity of GBM and its ability to escape therapeutic challenges are key factors contributing to the poor overall survival rate. While current treatments aim to target the cancer cell itself, they fail to consider the significant role that the GBM tumor microenvironment (TME) plays in promoting tumor progression and therapeutic resistance. The GBM tumor glycocalyx and glycan-rich extracellular matrix (ECM), which are important constituents of the TME have received little attention as therapeutic targets. A wide array of aberrantly modified glycans in the GBM TME mediate tumor growth, invasion, therapeutic resistance, and immunosuppression. Here, an overview of the landscape of aberrant glycan modifications in GBM is provided, and the design and utility of 3D glycomaterials are discussed as a tool to evaluate glycan-mediated GBM progression and therapeutic efficacy. The development of alternative strategies to target glycans in the TME can potentially unveil broader mechanisms of restricting tumor growth and enhancing the efficacy of tumor-targeting therapeutics.

The versatile role of HuR in Glioblastoma and its potential as a therapeutic target for a multi-pronged attack

Glioblastoma (GBM) is a malignant and aggressive brain tumor with a median survival of ∼15 months. Resistance to treatment arises from the extensive cellular and molecular heterogeneity in the three major components: glioma tumor cells, glioma stem cells, and tumor-associated microglia and macrophages. Within this triad, there is a complex network of intrinsic and secreted factors that promote classic hallmarks of cancer, including angiogenesis, resistance to cell death, proliferation, and immune evasion. A regulatory node connecting these diverse pathways is at the posttranscriptional level as mRNAs encoding many of the key drivers contain adenine- and uridine rich elements (ARE) in the 3' untranslated region. Human antigen R (HuR) binds to ARE-bearing mRNAs and is a major positive regulator at this level. This review focuses on basic concepts of ARE-mediated RNA regulation and how targeting HuR with small molecule inhibitors represents a plausible strategy for a multi-pronged therapeutic attack on GBM.

The Anti-VEGF(R) Drug Discovery Legacy: Improving Attrition Rates by Breaking the Vicious Cycle of Angiogenesis in Cancer

Resistance to anti-vascular endothelial growth factor (VEGF) molecules causes lack of response and disease recurrence. Acquired resistance develops as a result of genetic/epigenetic changes conferring to the cancer cells a drug resistant phenotype. In addition to tumor cells, tumor endothelial cells also undergo epigenetic modifications involved in resistance to anti-angiogenic therapies. The association of multiple anti-angiogenic molecules or a combination of anti-angiogenic drugs with other treatment regimens have been indicated as alternative therapeutic strategies to overcome resistance to anti-angiogenic therapies. Alternative mechanisms of tumor vasculature, including intussusceptive microvascular growth (IMG), vasculogenic mimicry, and vascular co-option, are involved in resistance to anti-angiogenic therapies. The crosstalk between angiogenesis and immune cells explains the efficacy of combining anti-angiogenic drugs with immune check-point inhibitors. Collectively, in order to increase clinical benefits and overcome resistance to anti-angiogenesis therapies, pan-omics profiling is key.

FUT8 and Protein Core Fucosylation in Tumours: From Diagnosis to Treatment

Glycosylation changes are key molecular events in tumorigenesis, progression and glycosyltransferases play a vital role in the this process. FUT8 belongs to the fucosyltransferase family and is the key enzyme involved in N-glycan core fucosylation. FUT8 and/or core fucosylated proteins are frequently upregulated in liver, lung, colorectal, pancreas, prostate,breast, oral cavity, oesophagus, and thyroid tumours, diffuse large B-cell lymphoma, ependymoma, medulloblastoma and glioblastoma multiforme and downregulated in gastric cancer. They can be used as markers of cancer diagnosis, occurrence, progression and prognosis. Core fucosylated EGFR, TGFBR, E-cadherin, PD1/PD-L1 and α3β1 integrin are potential targets for tumour therapy. In addition, IGg1 antibody defucosylation can improve antibody affinity, which is another aspect of FUT8 that could be applied to tumour therapy.

Nanotherapeutics for regeneration of degenerated tissue infected by bacteria through the multiple delivery of bioactive ions and growth factor with antibacterial/angiogenic and osteogenic/odontogenic capacity

Therapeutic options are quite limited in clinics for the successful repair of infected/degenerated tissues. Although the prevalent treatment is the complete removal of the whole infected tissue, this leads to a loss of tissue function and serious complications. Herein the dental pulp infection, as one of the most common dental problems, was selected as a clinically relevant case to regenerate using a multifunctional nanotherapeutic approach. For this, a mesoporous bioactive glass nano-delivery system incorporating silicate, calcium, and copper as well as loading epidermal growth factor (EGF) was designed to provide antibacterial/pro-angiogenic and osteo/odontogenic multiple therapeutic effects. Amine-functionalized Cu-doped bioactive glass nanospheres (Cu-BGn) were prepared to be 50-60 nm in size, mesoporous, positive-charged and bone-bioactive. The Cu-BGn could release bioactive ions (copper, calcium and silicate ions) with therapeutically-effective doses. The Cu-BGn treatment to human umbilical vein endothelial cells (HUVEC) led to significant enhancement of the migration, tubule formation and expression of angiogenic gene (e.g. vascular endothelial growth factor, VEGF). Furthermore, the EGF-loaded Cu-BGn (EGF@Cu-BGn) showed pro-angiogenic effects with antibacterial activity against E. faecalis, a pathogen commonly involved in the pulp infection. Of note, under the co-culture condition of HUVEC with E. faecalis, the secretion of VEGF was up-regulated. In addition, the osteo/odontogenic stimulation of the EGF@Cu-BGn was evidenced with human dental pulp stem cells. The local administration of the EGF@Cu-BGn in a rat molar tooth defect infected with E. faecalis revealed significant in vivo regenerative capacity, highlighting the nanotherapeutic uses of the multifunctional nanoparticles for regenerating infected/damaged hard tissues.

Proteomics identifies EGF-like domain multiple 7 as a potential therapeutic target for epidermal growth factor receptor-positive glioma

Background

Glioma, the most frequent primary tumor of the central nervous system, has poor prognosis. The epidermal growth factor receptor (EGFR) pathway and angiogenesis play important roles in glioma growth, invasion, and recurrence. The present study aimed to use proteomic methods to probe into the role of the EGF‐EGFR‐angiogenesis axis in the tumorigenesis of glioma and access the therapeutic efficacy of selumetinib on glioma.

Methods

Proteomic profiling was used to characterize 200 paired EGFR‐positive and EGFR‐negative glioma tissues of all pathological types. The quantitative mass spectrometry data were used for systematic analysis of the proteomic profiles of 10 EGFR‐positive and 10 EGFR‐negative glioma cases. Consensus‐clustering analysis was used to screen target proteins. Immunofluorescence analysis, cell growth assay, and intracranial xenograft experiments were used to verify and test the therapeutic effect of selumetinib on glioma.

Results

Advanced proteomic screening demonstrated that the expression of EGF‐like domain multiple 7 (EGFL7) was higher in EGFR‐positive tumor tissues than in EGFR‐negative tumor tissues. In addition, EGFL7 could act as an activator in vitro and in vivo to promote glioma cell proliferation. EGFL7 was associated strongly with EGFR and prognosis. EGFL7 knockdown effectively suppressed glioma cell proliferation. Selumetinib treatment showed tumor reduction effect in EGFR‐positive glioblastoma xenograft mouse model.

Conclusions

EGFL7 is a potential diagnostic biomarker and therapeutic target of glioma. Selumetinib could target the EGFR pathway and possibly improve the prognosis of EGFR‐positive glioma.

Quantifying the strength of heterointeractions among receptor tyrosine kinases from different subfamilies: Implications for cell signaling

Receptor tyrosine kinases (RTKs) are single-pass membrane proteins that control vital cell processes such as cell growth, survival, and differentiation. There is a growing body of evidence that RTKs from different subfamilies can interact and that these diverse interactions can have important biological consequences. However, these heterointeractions are often ignored, and their strengths are unknown. In this work, we studied the heterointeractions of nine RTK pairs, epidermal growth factor receptor (EGFR)-EPH receptor A2 (EPHA2), EGFR-vascular endothelial growth factor receptor 2 (VEGFR2), EPHA2-VEGFR2, EPHA2-fibroblast growth factor receptor 1 (FGFR1), EPHA2-FGFR2, EPHA2-FGFR3, VEGFR2-FGFR1, VEGFR2-FGFR2, and VEGFR2-FGFR3, using a FRET-based method. Surprisingly, we found that RTK heterodimerization and homodimerization strengths can be similar, underscoring the significance of RTK heterointeractions in signaling. We discuss how these heterointeractions can contribute to the complexity of RTK signal transduction, and we highlight the utility of quantitative FRET for probing multiple interactions in the plasma membrane.

Efficacy and Safety of Epidermal Growth Factor Receptor (EGFR) Inhibitors Plus Antiangiogenic Agents as First-Line Treatments for Patients With Advanced EGFR-Mutated Non-small Cell Lung Cancer: A Meta-Analysis

Background: Tyrosine kinase inhibitors (TKIs) are standard treatment options for non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. Increasing clinical investigations have explored the value of EGFR-TKIs plus antiangiogenic drugs as the first-line treatment for EGFR-mutated NSCLC. Methods: We systematically searched PubMed, Cochrane Library, and EMBASE for randomized controlled trials (RCTs) investigating EGFR-TKIs administered with or without antiangiogenic agents for advanced EGFR-mutated NSCLC. The latest RCT that was presented orally at the 2019 European Society for Medical Oncology Congress was obtained online. The endpoints included progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rates (DCRs), and grade 3 or higher adverse events (AEs). Results: We included seven articles on five trials with 1,226 patients. The interventions for the experimental group were the first-generation EGFR-TKI erlotinib combined with bevacizumab (four studies) or ramucirumab (one study), and erlotinib monotherapy (four studies) or erlotinib plus placebo (one study) for the control group. All studies reached their primary study endpoints (i.e., PFS). Compared to erlotinib monotherapy, erlotinib plus antiangiogenic agents remarkably prolonged PFS [hazard ratio (HR) = 0.59, 95% confidence interval (CI) = 0.51-0.69, P = 0.000]; however, ORR, DCR, and OS were similar between the two groups. The overall grade 3-5 AEs increased in combination group (OR = 5.772, 95% CI = 2.38-13.94, P = 0.000), particularly the incidence of diarrhea (OR = 2.51, 95% CI = 1.21-5.23, P = 0.014), acneiform (OR = 1.815, 95% CI = 1.084-3.037, P = 0.023), hypertension (OR = 6.77, 95% CI = 3.62-12.66, P = 0.000), and proteinuria (OR = 13.48, 95% CI = 4.11-44.22, P = 0.000). Additionally, subgroup analysis demonstrated that Asian patients could significantly benefit from combination therapy (HR = 0.59, 95% CI = 0.50-0.69, P = 0.000). Patients with exon 19 deletions (HR = 0.61, 95% CI = 0.49-0.75, P = 0.000) and 21 Leu858Arg mutations (HR = 0.59, 95% CI = 0.47-0.73, P = 0.000) had almost equivalent PFS benefits when treated with double-blocking therapy. Patients with brain metastases at baseline in the combination group had a trend toward better PFS (HR = 0.55, 95% CI = 0.30-1.01, P = 0.001). Conclusions: Erlotinib plus bevacizumab or ramucirumab in EFGR-mutated NSCLC first-line setting yielded remarkable PFS benefits; however, this was accompanied by higher AEs. Epidermal growth factor receptor-TKI plus antiangiogenic agent therapy may be considered a new option for advanced EGFR-mutated NSCLC patients.

Determining the appropriate treatment for different EGFR mutations in non-small cell lung cancer patients

Introduction: Epidermal growth factor receptor (EGFR) mutations occur in a significant fraction of non-small cell lung cancer (NSCLC) patients. Most common activating mutations are in-frame deletion in exon 19 and point mutation in exon 21. EGFR tyrosine kinase inhibitors (TKIs) represent standard of care of EGFR mutated patients bearing common mutations. Therapy for individuals carrying uncommon mutations, such as G719X, L861Q, S768I, is less defined and few options exist for individuals harboring EGFR exon 20 mutations. In all mutated patients, drug resistance remains the most critical clinical problem and new agents and strategies are under investigation.Areas covered: We have reviewed the current status of NSCLC EGFR mutated treatment by analyzing data from preclinical studies, clinical prospective and retrospective trials in order to analyze current and future options for patients harboring different EGFR mutations.Expert opinion: At the present time, available data demonstrated that osimertinib is the best EGFR-TKI for front-line therapy. Other agents, such as dacomitinib, and new drug combinations, such as regimens including anti-angiogenic agents or chemotherapy, demonstrated to significantly prolong progression-free survival or overall survival, representing potential alternative to osimertinib. Many questions remain opened, including best drug sequencing and needing of new therapeutic approaches extending patient survival and cure rate.

Hypoxia and EGF Stimulation Regulate VEGF Expression in Human Glioblastoma Multiforme (GBM) Cells by Differential Regulation of the PI3K/Rho-GTPase and MAPK Pathways

Glioblastoma multiforme (GBM) is one of the most common and deadly cancers of the central nervous system (CNS). It is characterized by the presence of hypoxic regions, especially in the core, leading to an increase in vascularity. This increased vascularization is driven by the expression of the major angiogenic inducer VEGF and the indirect angiogenic inducer Epidermal growth factor (EGF), which stimulates VEGF expression. In this study, we examine the regulation of VEGF by both hypoxia and the EGF signaling pathway. We also examine the involvement of pathways downstream from EGF signaling, including the mitogen-activated protein kinase/extracellular regulated kinase (MAPK/ERK) pathway and the Phosphatidylinositol-3-kinase/RhoA/C (PI3K/RhoA/C) pathway in this regulation. Our results show that VEGF expression and secretion levels increase following either hypoxia or EGF stimulation, with the two stimuli signaling in parallel. We also observed an increase in ERK and protein kinase B (Akt) phosphorylation, in response to EGF stimulation, with kinetics that correlated with the kinetics of the effect on VEGF. Using pharmacological inhibitors against ERK and PI3K and small interfering RNAs (siRNAs) against RhoA and RhoC, we found that both the ERK and the PI3K/RhoA/C pathways have to cooperate in order to lead to an increase in VEGF expression, downstream from EGF. In response to hypoxia, however, only ERK was involved in the regulation of VEGF. Hypoxia also led to a surprising decrease in the activation of PI3K and RhoA/C. Finally, the decrease in the activation of these Rho-GTPases was found to be mediated through a hypoxia-driven overexpression of the Rho-GTPase GTPase activating protein (GAP), StarD13. Therefore, while under normoxic conditions, EGF stimulates the activation of both the PI3K and the MAPK pathways and the induction of VEGF, in glioblastoma cells, hypoxic conditions lead to the suppression of the PI3K/RhoA/C pathway and an exclusive switch to the MAPK pathway.

Next Generation Sequencing-Based Transcriptome Predicts Bevacizumab Efficacy in Combination with Temozolomide in Glioblastoma

Glioblastoma (GBM), the most common and malignant brain tumor, is classified according to its isocitrate dehydrogenase (IDH) mutation status in the 2016 World Health Organization (WHO) brain tumor classification scheme. The standard treatment for GBM is maximal resection, radiotherapy, and Temozolomide (TMZ). Recently, Bevacizumab (Bev) has been added to basic therapy for newly diagnosed GBM, and monotherapy for recurrent GBM. However, the effect of IDH1 mutation on the combination of Bev and TMZ is unknown. In this study, we performed transcriptomic analysis by RNA sequencing with next generation sequencing (NGS), a newly developed powerful method that enables the quantification of the expression level of genome-wide genes. Extracellular matrix and immune cell migration genes were mainly upregulated whereas cell cycle genes were downregulated in IDH1-mutant U87 cells but not in IDH1-wildtype U87 cells after adding Bev to TMZ. In vitro and in vivo studies were conducted for further investigations to verify these results, and the addition of Bev to TMZ showed a significant antitumor effect only in the IDH1-mutant GBM xenograft model. Further studies of gene expression profiling in IDH1 mutation gliomas using NGS will provide more genetic information and will lead to new treatments for this refractory disease.

Effects of Far-infrared Ray on Temozolomide-treated Glioma in Rats

BACKGROUND/AIM

Malignant glioma is a rapidly progressive primary brain cancer. The aim of the study was to investigate the effect of far-infrared ray (FIR) on temozolomide (TMZ)-treated glioma in rats.

MATERIALS AND METHODS

Male, 8-week old, Fischer 344 inbred rats with glioma were randomly divided into three study groups (20 rats in each group). The control group received saline only once daily for 5 days. The TMZ group received TMZ (30 mg/kg) once daily for 5 days. The TMZ plus FIR group received TMZ (30 mg/kg) once daily for 5 days and infrared-c irradiation of 40 min twice daily for 4 weeks. The relative tumor fold and the expression of hypoxia-induced factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were compared using one-way ANOVA at the end of study.

RESULTS

The relative tumor fold of the TMZ+FIR group was significantly higher compared to the control group, and was borderline higher compared to the TMZ group at Day 7. The relative tumor fold of TMZ+FIR group was significantly higher compared to the control group and the TMZ group at Days 14, 21 and 28. HIF-1α expression of TMZ+FIR group was borderline higher compared to the control group at Day 28. The VEGF expression of TMZ+FIR group was significantly higher compared to the control group and the TMZ group at Day 28.

CONCLUSION

FIR might increase the growth of glioma under TMZ treatment in rats possibly via increasing VEGF expression, but not HIF-1α expression.

Combinations of Bevacizumab With Cancer Immunotherapy

Cancer immunotherapy (CIT) has transformed cancer treatment. In particular, immunotherapies targeting the programmed death ligand 1 (PD-L1)/programmed death 1 pathway have demonstrated durable clinical benefit in some patients. However, CIT combinations may create a more favorable environment in which to maximize the potential of the immune system to eliminate cancer. Here we describe 3 key mechanisms related to vascular endothelial growth factor (VEGF)-mediated immunosuppression: inhibition of dendritic cell maturation, reduction of T-cell tumor infiltration, and promotion of inhibitory cells in the tumor microenvironment; supporting data are also described. In addition, we discuss immunomodulatory properties observed within tumors following bevacizumab treatment. Combining anti-PD-L1 and anti-VEGF therapies has shown synergy and positive outcomes in phases I to III studies, particularly in settings where high VEGF levels are known to play an important role in tumor growth. We also review data from key studies supporting combination of bevacizumab and CIT, with a focus on PD-L1/programmed death 1 inhibitors.

EGFR heterogeneity and implications for therapeutic intervention in glioblastoma

Patients with glioblastoma (GBM) have a universally poor prognosis and are in urgent need of effective treatment strategies. Recent advances in sequencing techniques unraveled the complete genomic landscape of GBMs and revealed profound heterogeneity of individual tumors even at the single cell level. Genomic profiling has detected epidermal growth factor receptor (EGFR) gene alterations in more than half of GBMs. Major genetic events include amplification and mutation of EGFR. Yet, treatment strategies targeting EGFR have thus far failed in clinical trials. In this review, we discuss the clonal and functional heterogeneity of EGFRs in GBM development and critically reassess the potential of EGFRs as therapeutic targets.

Prevalence of human immunodeficiency virus infection in brain glioma patients: Is the virus protective from gliomas?

Background:

Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) is associated with an increased prevalence of some malignancies. However, some observational studies have revealed an ever-decreasing prevalence of HIV in glioma patients. The relationship between HIV and brain gliomas has not been well established.

Methods:

A cross-sectional study was carried out in sub-Sahara Africa, a high HIV prevalence setting, to determine the prevalence of HIV among all glioma patients over a 2-year period.

Results:

A markedly reduced prevalence of HIV was found in glioma patients (8.3%) in comparison to the general population (14.3%). The presumably “antiglioma effect” of HIV and/or its treatment resulted in a 42% decrease in glioma occurrence in HIV positive patients compared to HIV negative individuals. Age and sex-adjusted prevalence were also lower among glioma patients with the protective effect observed more in younger patients and female sex.

Conclusion:

Our results corroborate the protective effect of HIV positivity vis-à -vis gliomas. This “antiglioma effect” could be attributed to either the HIV, its treatment, or both. Future studies focused on this “effect” may help unveil better preventative and possible therapeutic avenues for gliomas.

Brain-Tumor-Regenerating 3D Scaffold-Based Primary Xenograft Models for Glioma Stem Cell Targeted Drug Screening

Glioma stem cells (GSC) present a critical therapeutic challenge for glioblastoma multiforme (GBM). Drug screening against GSC demands development of novel in vitro and in vivo platforms that can mimic brain microenvironment and support GSC maintenance and tumorigenesis. Here, we report, a 3-dimensionel (3D) biomimetic macro-porous scaffold developed by incorporating hyaluronic acid, porcine brain extra cellular matrix (ECM) and growth factors that facilitates regeneration of GBM from primary GSCs, ex vivo and in vivo. After characterizing with human and rat GBM cell lines and neurospheres, human GSCs expressing Notch1, Sox-2, Nestin, and CD133 biomarkers were isolated from GBM patients, cultured in the 3D scaffold, and implanted subcutaneously in nude mice to develop patient derived xenograft (PDX) models. Aggressive growth pattern of PDX with formation of intratumoral vascularization was monitored by magnetic resonance imaging (MRI). Histopathological and phenotypial features of the original tumors were retained in the PDX models. We used this regenerated GBM platform to screen novel siRNA nanotherapeutics targeting Notch, Sox-2, FAK signaling for its ability to inhibit the tumorigenic potential of GSCs. Current clinical drug, Temozolomide and an anticancer phytochemical, nanocurcumin, were used as controls. The siRNA nanoparticles showed excellent efficacy in inhibiting tumorigenesis by GSCs in vivo. Our study suggests that the brain-ECM mimicking scaffold can regenerate primary gliomas from GSCs in vitro and in vivo, and the same can be used as an effective platform for screening drugs against glioma stem cells.

EGFR-targeted therapies in the post-genomic era

Over 90% of head and neck cancers overexpress the epidermal growth factor receptor (EGFR). In diverse tumor types, EGFR overexpression has been associated with poorer prognosis and outcomes. Therapies targeting EGFR include monoclonal antibodies, tyrosine kinase inhibitors, phosphatidylinositol 3-kinase (PI3K) inhibitors, and antisense gene therapy. Few EGFR-targeted therapeutics are approved for clinical use. The monoclonal antibody cetuximab is a Food and Drug Administration (FDA)-approved EGFR-targeted therapy, yet has exhibited modest benefit in clinical trials. The humanized monoclonal antibody nimotuzumab is also approved for head and neck cancers in Cuba, Argentina, Colombia, Peru, India, Ukraine, Ivory Coast, and Gabon in addition to nasopharyngeal cancers in China. Few other EGFR-targeted therapeutics for head and neck cancers have led to as significant responses as seen in lung carcinomas, for instance. Recent genome sequencing of head and neck tumors has helped identify patient subgroups with improved response to EGFR inhibitors, for example, cetuximab in patients with the KRAS-variant and the tyrosine kinase inhibitor erlotinib for tumors harboring MAPK1^E322K mutations. Genome sequencing has furthermore broadened our understanding of dysregulated pathways, holding the potential to enhance the benefit derived from therapies targeting EGFR.

Rationale and Clinical Results of Multi-target Treatments in Oncology

During the last 10 years, the concept of targeted biological therapy for the treatment of cancer has emerged. Targeted agents entered clinical practice only recently, and the first drugs with demonstrated clinical efficacy were mainly inhibitors of the ErbB family of receptors (i.e., EGFR and HER-2), either monoclonal antibodies (MAbs) or tyrosine kinase inhibitors (TKIs). After the proof of concept for the clinical efficacy and tolerability of these selective agents, it was conceived that most tumors will depend on more than one signaling pathway for their growth and survival. As a consequence, different strategies were pursued to inhibit multiple signaling pathways or multiple steps in the same pathway, either by the development of multi-targeted agents or the combination of single targeted drugs. The recent FDA and EMEA approval of sorafenib and sunitinib, both multi-targeted TKIs, marked the coming of age of this new generation of drugs. Now a whole new wave of multi-targeted compounds is moving into clinical trials, raising in the minds of investigators important questions about the best strategies to pursue in their use and many doubts about their differences and the seeming redundancies in the pipelines of pharmaceutical companies. This review will deal with the rationale underlying the multi-targeted approach and with the available clinical experience with multi-targeted agents, especially focusing on molecules with anti-EGFR mechanisms of action.

Enhanced selective cellular uptake and cytotoxicity of epidermal growth factor-conjugated liposomes containing curcumin on EGFR-overexpressed pancreatic cancer cells

Pancreatic cancer is one of the most malignant cancers with a high mortality rate. Some types of pancreatic cancer cells overexpress epidermal growth factor receptor (EGFR), which is a potential target for anticancer agents. In this study, we examined the effect of epidermal growth factor (EGF)-conjugated liposomes containing curcumin (EGF-LP-Cur) on three different EGFR-expressed human pancreatic cancer cell lines, BxPC-3, Panc-1 and Mia Paca-2. We have demonstrated that it is feasible to prepare liposomal vesicles of EGF-LP-Cur and that it is stable in the liquid vehicle at ambient conditions for three weeks. In addition, the formulation of curcumin had higher cytotoxicity on BxPC-3 than on any other cells. It is also shown that the cellular uptake of curcumin on BxPC-3, which is essential for the cytotoxicity, is associated with EGFR-mediated mechanism of action. In summary, our results have showed that targeting EGFR with EGF-conjugated curcumin liposomes enhanced the antitumor activity of curcumin against human pancreatic cancer cells.

EGF regulation of proximal tubule cell proliferation and VEGF-A secretion

Proximal tubule cell (PTC) proliferation is critical for tubular regeneration and recovery from acute kidney injury. Epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF‐A) are important for the maintenance of tubulointerstitial integrity and can stimulate PTC proliferation. We utilized HK‐2 cells, an immortalized human PTC line, to characterize the EGF‐dependent regulation of VEGF‐A secretion and proliferation in PTCs. We demonstrate that EGF stimulates VEGF‐A secretion via the EGF receptor (EGFR) and stimulates cell proliferation via activation of the VEGF receptor, VEGFR‐2. EGFR activation promotes MAPK (ERK1/2) activation and HIF‐1α expression, which are required for basal and EGF‐stimulated VEGF‐A secretion. EGF also stimulates the phosphorylation of P70S6 kinase (P70S6K), the downstream target of mTORC1. Rapamycin decreased basal and EGF stimulated HIF‐1α and enhanced MAPK (ERK1/2) activation, while MAPK (ERK/12) inhibition downregulated HIF‐1α expression and the phosphorylation of p70S6K. EGF stimulation of p70S6K was also independent of p‐AKT. Inhibition of the mTORC1 pathway with rapamycin abolished phosphorylation of p70S6K but had no effect on VEGF‐A secretion, indicating that EGF‐stimulated VEGF‐A secretion did not require mTORC1 pathway activation. We demonstrate evidence of a complex crosstalk between the MAPK/ERK and mTORC1 pathways, wherein MAPK (ERK1/2) activation stimulates p‐P70S6K, while p‐P70S6K activation seems to inhibit MAPK (ERK1/2) in EGF‐treated HK‐2 cells. Our results suggest that EGF stimulates MAPK (ERK1/2) in HK‐2 cells, which in turn increases HIF‐1α expression and VEGF‐A secretion, indicating that VEGF‐A mediates EGF‐stimulated cell proliferation as an autocrine proximal tubular epithelial cell growth factor.

Neoalbaconol inhibits angiogenesis and tumor growth by suppressing EGFR-mediated VEGF production

Neoalbaconol, derived from Albatrellus confluens, shows anti-cancer activities in the previously study, but its role in angiogenesis is unknown. Here, we determined whether neoalbaconol could attenuate angiogenesis and how does it occur. Data demonstrated that neoalbaconol could inhibit the proliferation of breast cancer cells and induce apoptosis. Also, neoalbaconol suppressed vascular endothelial growth factor (VEGF)-induced human umbilical vascular endothelial cells (HUVECs) proliferation, migration, invasion, and capillary-like tube formation in vitro and reduced tumor angiogenesis in vivo. VEGF receptor activation and the downstream signal transduction cascades activation were inhibited by neoalbaconol. Additionally, neoalbaconol blocked EGFR-mediated VEGF production. EGFR overexpression reversed the neoalbaconol-induced VEGF reduction, confirming the importance of the EGFR inhibition in anti-angiogenesis of neoalbaconol. Furthermore, neoalbaconol inhibited tumor growth and tumor angiogenesis in a breast cancer xenograft model in vivo. Taken together, these results indicate that neoalbaconol could inhibit tumor angiogenesis and growth through direct suppression effects on vascular endothelial cells and reduction of proangiogenic factors in cancer cells.

Vascular permeability in the RG2 glioma model can be mediated by macropinocytosis and be independent of the opening of the tight junction

This study evaluates the extravasation pathways of circulating macromolecules in a rat glioma model (RG2) which was observed by both magnetic resonance imaging using ultrasmall superparamagnetic iron oxide and electron microscopy. Although magnetic resonance imaging signal enhancement was observed as soon as 10 min after injection (9.4% 2 h after injection), electron microscopy showed that endothelial cells were still tightly sealed. However, circulating immunoglobulin G and ultrasmall superparamagnetic iron oxide were found in large membrane compartments of endothelial cells, in the basal lamina (7.4 ± 1.2 gold particles/µm² in the tumor versus 0.38 ± 0.17 in healthy tissue, p = 1.4.10^-5) and between tumoral cells. Altogether, this strongly suggests an active transport mediated by macropinocytosis. To challenge this transport mechanism, additional rats were treated with amiloride, an inhibitor of macropinocytosis, leading to a reduction of membrane protrusions (66%) and of macropinosomes. Amiloride however also opened tumoral tight junctions allowing a larger extravasation of ultrasmall superparamagnetic iron oxide (magnetic resonance imaging signal enhancement of 35.7% 2 h after injection). Altogether, these results suggest that ultrasmall superparamagnetic iron oxide and immunoglobulin G in the RG2 glioma model follow an active extravasation pathway mediated by a macropinocytosis process. Amiloride also appears as a potential strategy to facilitate the extravasation of chemotherapeutic drugs in glioma.

Imaging Surrogates of Infiltration Obtained Via Multiparametric Imaging Pattern Analysis Predict Subsequent Location of Recurrence of Glioblastoma

BACKGROUND

Glioblastoma is an aggressive and highly infiltrative brain cancer. Standard surgical resection is guided by enhancement on postcontrast T1-weighted (T1) magnetic resonance imaging, which is insufficient for delineating surrounding infiltrating tumor.

OBJECTIVE

To develop imaging biomarkers that delineate areas of tumor infiltration and predict early recurrence in peritumoral tissue. Such markers would enable intensive, yet targeted, surgery and radiotherapy, thereby potentially delaying recurrence and prolonging survival.

METHODS

Preoperative multiparametric magnetic resonance images (T1, T1-gadolinium, T2-weighted, T2-weighted fluid-attenuated inversion recovery, diffusion tensor imaging, and dynamic susceptibility contrast-enhanced magnetic resonance images) from 31 patients were combined using machine learning methods, thereby creating predictive spatial maps of infiltrated peritumoral tissue. Cross-validation was used in the retrospective cohort to achieve generalizable biomarkers. Subsequently, the imaging signatures learned from the retrospective study were used in a replication cohort of 34 new patients. Spatial maps representing the likelihood of tumor infiltration and future early recurrence were compared with regions of recurrence on postresection follow-up studies with pathology confirmation.

RESULTS

This technique produced predictions of early recurrence with a mean area under the curve of 0.84, sensitivity of 91%, specificity of 93%, and odds ratio estimates of 9.29 (99% confidence interval: 8.95-9.65) for tissue predicted to be heavily infiltrated in the replication study. Regions of tumor recurrence were found to have subtle, yet fairly distinctive multiparametric imaging signatures when analyzed quantitatively by pattern analysis and machine learning.

CONCLUSION

Visually imperceptible imaging patterns discovered via multiparametric pattern analysis methods were found to estimate the extent of infiltration and location of future tumor recurrence, paving the way for improved targeted treatment.

Epidermal growth factor receptor mutation enhances expression of vascular endothelial growth factor in lung cancer

Epidermal growth factor receptor (EGFR) activation has been demonstrated to have a critical role in tumor angiogenesis. In the present study, the correlation between EGFR mutations and vascular endothelial growth factor (VEGF) was investigated in lung cancer cell lines and non-small-cell lung cancer (NSCLC) tumor tissues. VEGF levels were significantly increased in culture medium of lung cancer cells and NSCLC tissues with EGFR mutations (H1650 vs. A549, P=0.0399; H1975 vs. A549, P<0.0001). Stable lung cancer cell lines expressing mutant (exon 19 deletion, E746-A750; exon 21 missense mutation, L858R) and wild-type EGFR genes were established. Significantly increased expression of VEGF and stronger inhibitory effects of gefitinib to VEGF expression were observed in exon 19 deletion stable lung cancer cells (exon 19 deletion vs. wild-type EGFR, P=0.0005). The results of the present study may provide an insight into the association of mutant EGFR and VEGF expression in lung cancer, and may assist with further development of targeted therapy for NSCLC in the future.

Vascular Endothelial Growth Factor Activation of Intramembranous Absorption: A Critical Pathway for Amniotic Fluid Volume Regulation

OBJECTIVE

The purpose of this review is to propose a critical role for vascular endothelial growth factor (VEGF) in mediating the transfer of amniotic fluid from the amniotic compartment through the fetal membranes and fetal surface of the placenta into fetal blood.

METHODS

Experimental findings in humans and animal models on the action of VEGF in mediating fluid transfer are reviewed and interpreted in order to postulate a proposed mechanism for VEGF regulation of amniotic fluid absorption through the fetal membranes and placenta.

RESULTS

Recent scientific advances suggest that up-regulation of VEGF gene expression in the amnion and chorion is associated with increased transfer of amniotic fluid into fetal blood. The possible mechanisms of action for VEGF appear to involve regulation of intramembranous blood vessel proliferation and membrane transport via passive permeation as well as nonpassive transcytotic vesicular movement of fluid.

CONCLUSION

Currently evolving concepts suggest that amniotic fluid volume is regulated through modulation of the rate of intramembranous absorption of amniotic fluid by both passive and nonpassive mechanisms. The permeability factor VEGF appears to be a critical regulator of amniotic fluid transport in the fetal membranes.

Immunosuppressive mechanisms in glioblastoma

Despite maximal surgical and medical therapy, the treatment of glioblastoma remains a seriously vexing problem, with median survival well under 2 years and few long-term survivors. Targeted therapy has yet to produce significant advances in treatment of these lesions in spite of advanced molecular characterization of glioblastoma and glioblastoma cancer stem cells. Recently, immunotherapy has emerged as a promising mode for some of the hardest to treat tumors, including metastatic melanoma. Although immunotherapy has been evaluated in glioblastoma in the past with limited success, better understanding of the failures of these therapies could lead to more successful treatments in the future. Furthermore, there is a persistent challenge for the use of immune therapy to treat glioblastoma secondary to the existence of redundant mechanisms of tumor-mediated immune suppression. Here we will address these mechanisms of immunosuppression in glioblastoma and therapeutic approaches.

Novel pyrazolopyridine derivatives as potential angiogenesis inhibitors: Synthesis, biological evaluation and transcriptome-based mechanistic analysis

Modified purine derivatives exemplified by pyrazolopyrimidines have emerged as highly selective inhibitors of several angiogenic receptor tyrosine kinases. Herein, we designed and synthesized a new series of substituted pyrazolopyridines and explored their ability to influence crucial pro-angiogenic attributes of endothelial cells. Four of the synthesized compounds, possessing analogous substitution pattern, were found able to inhibit at low micromolar concentrations endothelial cell proliferation, migration and differentiation, constitutively or in response to Vascular Endothelial Growth Factor (VEGF) and to attenuate VEGF-induced phosphorylation of VEGF receptor-2 and downstream kinases AKT and ERK1/2. Administration of effective compounds in mice delayed the growth of syngeneic Lewis lung carcinoma transplants and reduced tumor microvessel density, without causing toxicity. Genome-wide microarray and gene ontology analyses of treated endothelial cells revealed derivative 18c as the most efficient modulator of gene expression and "mitotic cell cycle/cell division" along with "cholesterol biosynthesis" as the most significantly altered biological processes.

BEVERLY: Rationale and Design of a Randomized Open-Label Phase III Trial Comparing Bevacizumab Plus Erlotinib Versus Erlotinib Alone as First-Line Treatment of Patients With EGFR-Mutated Advanced Nonsquamous Non-Small-Cell Lung Cancer

BACKGROUND

About 20% of advanced non-small-cell lung cancer (NSCLC) cases harbor somatic mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene. In these patients, the standard first-line treatments are the EGFR-tyrosine kinase inhibitors, such as gefitinib, erlotinib, or afatinib. Most of these patients develop resistance and relapse within about 1 year of initiation of an EGFR-tyrosine kinase inhibitor. Consequently, it is important to develop new combination strategies to delay this resistance. Preclinical data have showed that EGFR and vascular endothelial growth factor (VEGF) share a common downstream pathway, suggesting the important role of VEGF in the resistance to EGFR blockade. The combination of erlotinib and bevacizumab, an anti-VEGF agent, showed very interesting clinical results.

PATIENTS AND METHODS

The bevacizumab plus erlotinib study (BEVERLY) is a randomized, open-label, phase III trial investigating first-line erlotinib plus bevacizumab versus erlotinib in patients with advanced NSCLC harboring activating EGFR mutations. The co-primary endpoints are investigator-assessed progression-free survival (PFS) and blinded, independent centrally reviewed PFS. The secondary endpoints include overall survival, quality of life, objective response rate, and safety. A total of 200 patients will be randomized 1:1 to receive oral erlotinib (150 mg daily) plus bevacizumab (15 mg/kg, intravenously, on day 1 of every 21-day cycle) or erlotinib alone, until objective disease progression or unacceptable toxicity or the patient's or physician's motivated decision to stop the treatment.

CONCLUSION

If the primary endpoint of PFS is met, the erlotinib plus bevacizumab combination will be confirmed as the best first-line treatment for patients with advanced NSCLC harboring activating EGFR mutations.

miR-21 Is Linked to Glioma Angiogenesis: A Co-Localization Study

MicroRNA-21 (miR-21) is the most consistently over-expressed microRNA (miRNA) in malignant gliomas. We have previously reported that miR-21 is upregulated in glioma vessels and subsets of glioma cells. To better understand the role of miR-21 in glioma angiogenesis and to characterize miR-21-positive tumor cells, we systematically stained consecutive serial sections from ten astrocytomas for miR-21, hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), phosphatase and tensin homolog (PTEN), octamer-binding transcription factor 4 (Oct4), sex-determining region Y box 2 (Sox2) and CD133. We developed an image analysis-based co-localization approach allowing global alignment and quantitation of the individual markers, and measured the miR-21 in situ hybridization signal against the immunohistochemical staining of the six different markers. miR-21 significantly co-localized with the hypoxia- and angiogenesis-associated markers HIF-1α (p=0.0020) and VEGF (p=0.0096), whereas the putative miR-21 target, PTEN, was expressed independently of miR-21. Expression of stem cell markers Oct4, Sox2 and CD133 was not associated with miR-21. In six glioblastoma cultures, miR-21 did not correlate with the six markers. These findings suggest that miR-21 is linked to glioma angiogenesis, that miR-21 is unlikely to regulate PTEN, and that miR-21-positive tumor cells do not possess stem cell characteristics.

Lapatinib ameliorates experimental arthritis in rats

Epidermal growth factor receptor (EGFR) and its ligands are commonly expressed by synovial cells. The aim of the present study was to detect the potential effect of lapatinib an inhibitor of EGFR tyrosine kinases on collagen-induced arthritis. Thirty Wistar albino female rats were randomized into three groups. Arthritis was induced by intradermal injection of chicken type II collagen with incomplete Freund's adjuvant. Serum TNF-α, IL-17, and malondialdehyde (MDA) levels were analyzed. Tissue superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) activities, and nuclear factor erythroid 2-related factor-2 (Nrf2) and heme oxgenase-1 (HO-1) expressions were determined. TNF-α, IL-17 and MDA levels, and Nrf2 and HO-1 expressions were lower in lapatinib-treated (30 mg/kg/day) group compared to sham group, while SOD, catalase, and GPx activities were higher (p < 0.05). Moreover, lapatinib ameliorated perisynovial inflammation and cartilage-bone destruction (p < 0.001). In conclusion, EGFR may have prominent pathogenic role and lapatinib may be an effective therapeutic option for arthritis.

Selective coexpression of VEGF receptor 2 in EGFRvIII-positive glioblastoma cells prevents cellular senescence and contributes to their aggressive nature

BACKGROUND

In glioblastoma (GBM), the gene for epidermal growth factor receptor (EGFR) is frequently amplified. EGFR mutations also are common, including a truncation mutation that yields a constitutively active variant called EGFR variant (v)III. EGFRvIII-positive GBM progresses rapidly; however, the reason for this is not clear because the activity of EGFRvIII is attenuated compared with EGF-ligated wild-type EGFR. We hypothesized that EGFRvIII-expressing GBM cells selectively express other oncogenic receptors that support tumor progression.

METHODS

Mining of The Cancer Genome Atlas prompted us to test whether GBM cells in culture, which express EGFRvIII, selectively express vascular endothelial growth factor receptor (VEGFR)2. We also studied human GBM propagated as xenografts. We then applied multiple approaches to test the effects of VEGFR2 on GBM cell growth, apoptosis, and cellular senescence.

RESULTS

In human GBM, EGFR overexpression and EGFRvIII positivity were associated with increased VEGFR2 expression. In GBM cells in culture, EGFRvIII-initiated cell signaling increased expression of VEGFR2, which prevented cellular senescence and promoted cell cycle progression. The VEGFR-selective tyrosine kinase inhibitor cediranib decreased tumor DNA synthesis, increased staining for senescence-associated β-galactosidase, reduced retinoblastoma phosphorylation, and increased p27(Kip1), all markers of cellular senescence. Similar results were obtained when VEGFR2 was silenced.

CONCLUSIONS

VEGFR2 expression by GBM cells supports cell cycle progression and prevents cellular senescence. Coexpression of VEGFR2 by GBM cells in which EGFR signaling is activated may contribute to the aggressive nature of these cells.

Current role of anti-angiogenic strategies for glioblastoma

OPINION STATEMENT

Glioblastoma, an incurable, malignant, and highly vascular tumor, is a seemingly ideal target for anti-angiogenic therapies such as bevacizumab, an anti-vascular endothelial growth factor (VEGF) monoclonal antibody. Phase II trials in recurrent glioblastoma demonstrated bevacizumab was associated with clinical benefits, including decreases in brain edema and corticosteroids use resulting from reduced vascular permeability, as well as radiographic responses in 25 %-40 % of patients. In newly diagnosed disease, a phase III trial (AVAglio) showed adding bevacizumab to standard chemoradiotherapy improved progression free survival (PFS), with preservation of quality of life, and reduced corticosteroids use, but did not improve overall survival (OS). Another similar phase III trial (RTOG 0825) found similar PFS and OS trends, but suggested that the addition of bevacizumab resulted in more frequent cognitive decline compared with standard chemoradiotherapy. However, interpretation of those findings is limited by the fact that progressing patients were not evaluated, and patients remained longer on study in the bevacizumab arm. It is possible that the observed cognitive decline represented unrecognized tumor progression, rather than deleterious bevacizumab effects. Regardless, even if real, it is difficult to ascertain how improvements in PFS and quality of life compare with the associated economic costs and increased toxicities of bevacizumab, in the setting of no survival benefit. Further studies in recurrent disease are being conducted; preliminary results of a randomized trial showed favorable results with the combination with CCNU, and final results are awaited. Meanwhile, outside the realm of clinical trials, the current trend appears to be to reserve bevacizumab for use in recurrent disease, or for patients with moderate or severe neurologic symptoms, either in the newly diagnosed or recurrent setting. Further research efforts are needed to determine optimal candidates for this treatment from a molecular standpoint, as well as to develop imaging tools capable of accurately identifying response and progression, and to establish new drug combinations that could result in unquestionable clinical benefit and improved survival in these patients.

Tumor Hypoxia Response After Targeted Therapy in EGFR-Mutant Non-Small Cell Lung Cancer: Proof of Concept for FMISO-PET

Hypoxia is associated with resistance to radiotherapy and chemotherapy. Functional imaging of hypoxia in non-small cell lung cancer (NSCLC) could allow early assessment of tumor response and guide subsequent therapies. Epidermal growth factor receptor (EGFR) inhibition with erlotinib reduces hypoxia in vivo. [18F]-Fluoromisonidazole (FMISO) is a radiolabeled tracer that selectively accumulates in hypoxic cells. We sought to determine whether FMISO positron emission tomography (FMISO-PET) could detect changes in hypoxia in vivo in response to EGFR-targeted therapy. In a preclinical investigation, nude mice with human EGFR-mutant lung adenocarcinoma xenografts underwent FMISO-PET scans before and 5 days after erlotinib or empty vehicle initiation. Descriptive statistics and analysis of variance (ANOVA) tests were used to analyze changes in standardized uptake value (SUV), with pooled analyses for the mice in each group (baseline, postvehicle, and posterlotinib). In a small correlative pilot human study, patients with EGFR-mutant metastatic NSCLC underwent FMISO-PET scans before and 10 to 12 days after erlotinib initiation. Changes in SUV were compared to standard chest computed tomography (CT) scans performed 6 weeks after erlotinib initiation. The mean (±standard error of the mean; SUVmean) of the xenografts was 0.17 ± 0.014, 0.14 ± 0.008, and 0.06 ± 0.004 for baseline, postvehicle, and posterlotinib groups, respectively, with lower SUVmean among the posterlotinib group compared to other groups (P < .05). Changes on preclinical PET imaging were striking, with near-complete disappearance of FMISO uptake after erlotinib initiation. Two patients were enrolled on the pilot study. In the first patient, SUVmean increased by 21% after erlotinib, with progression on 6-week chest CT followed by death after 4.8 months. In the second patient, SUVmean decreased by 7% after erlotinib, with regression on 6-week chest CT accompanied by clinical improvement; the patient had stable disease at 14.5 months. In conclusion, we observed that FMISO-PET can detect changes in hypoxia levels after EGFR-directed therapy in EGFR-mutant NSCLC. Further study is warranted to determine its utility as an imaging biomarker of early response to EGFR-directed therapy.