Combined treatment of Nimotuzumab and rapamycin is effective against temozolomide-resistant human gliomas regardless of the EGFR mutation status

Autophagy Inhibition via Hydroxychloroquine or 3-Methyladenine Enhances Chemotherapy-Induced Apoptosis in Neuro-Blastoma and Glioblastoma

Neuroblastoma is the most common tumour in children under 1 year old, accounting for 12-15% of childhood cancer deaths. Although current treatments are relatively efficacious against this cancer, associated adverse effects could be detrimental to growth and development. In contrast, glioblastoma accounts for 52% of brain tumours and has an extremely poor prognosis. Current chemotherapeutics include temozolomide, which has numerous negative side-effects and a low-effective rate. Previous studies have shown the manipulation of autophagy to be a promising method for targeting cancers, including glioblastoma. We sought to determine the effects of autophagic alterations in combination with current chemotherapies in both neuroblastoma and glioblastoma. Supplementing cisplatin or temozolomide with autophagy activator rapamycin stabilized cancer cell mitochondria, despite having little effect on apoptosis or oxidative stress. Autophagy inhibition via 3-methyladenine or hydroxychloroquine alongside standard chemotherapies enhanced apoptosis and oxidative stress, with 3-methyladenine also disrupting mitochondrial health. Importantly, combining hydroxychloroquine with 0.5 µM cisplatin or 50 µg/mL temozolomide was as or more effective than 2 µM cisplatin or 100 µg/mL temozolomide alone. Analyzing these interesting results, a combined treatment of autophagy inhibitor with a standard chemotherapeutic agent could help to improve patient prognosis and reduce chemotherapy doses and their associated side-effects.

Cell-Population Dynamics in Diffuse Gliomas during Gliomagenesis and Its Impact on Patient Survival

Diffuse gliomas continue to be an important problem in neuro-oncology. To solve it, studies have considered the issues of molecular pathogenesis from the intratumoral heterogeneity point. Here, we carried out a comparative dynamic analysis of the different cell populations' content in diffuse gliomas of different molecular profiles and grades, considering the cell populations' functional properties and the relationship with patient survival, using flow cytometry, immunofluorescence, multiparametric fluorescent in situ hybridization, polymerase chain reaction, and cultural methods. It was shown that an increase in the IDH-mutant astrocytomas and oligodendrogliomas malignancy is accompanied by an increase in stem cells' proportion and mesenchymal cell populations' appearance arising from oligodendrocyte-progenitor-like cells with cell plasticity and cells' hypoxia response programs' activation. In glioblastomas, malignancy increase is accompanied by an increase in both stem and definitive cells with mesenchymal differentiation, while proneuronal glioma stem cells are the most likely the source of mesenchymal glioma stem cells, which, in hypoxic conditions, further give rise to mesenchymal-like cells. Clinical confirmation was a mesenchymal-like cell and mesenchymal glioma stem cell number, and the hypoxic and plastic molecular programs' activation degree had a significant effect on relapse-free and overall survival. In general, we built a multi-vector model of diffuse gliomas' pathogenetic tracing up to the practical plane.

Identifying driver modules based on multi-omics biological networks in prostate cancer

The development of sequencing technology has promoted the expansion of cancer genome data. It is necessary to identify the pathogenesis of cancer at the molecular level and explore reliable treatment methods and precise drug targets in cancer by identifying carcinogenic functional modules in massive multi-omics data. However, there are still limitations to identifying carcinogenic driver modules by utilising genetic characteristics simply. Therefore, this study proposes a computational method, NetAP, to identify driver modules in prostate cancer. Firstly, high mutual exclusivity, high coverage, and high topological similarity between genes are integrated to construct a weight function, which calculates the weight of gene pairs in a biological network. Secondly, the random walk method is utilised to reevaluate the strength of interaction among genes. Finally, the optimal driver modules are identified by utilising the affinity propagation algorithm. According to the results, the authors' method identifies more validated driver genes and driver modules compared with the other previous methods. Thus, the proposed NetAP method can identify carcinogenic driver modules effectively and reliably, and the experimental results provide a powerful basis for cancer diagnosis, treatment and drug targets.

Radiotherapy Plus Temozolomide With or Without Nimotuzumab Against the Newly Diagnosed EGFR-Positive Glioblastoma: A Retrospective Cohort Study

BACKGROUND

Glioblastoma (GBM) has a poor prognosis, and patients with epidermal growth factor receptor (EGFR) amplification have an even worse prognosis. Nimotuzumab is an EGFR monoclonal antibody thought to play a significant role in the treatment of GBM. This paper presents a retrospective cohort study that evaluates the clinical efficacy and safety of nimotuzumab in GBM.

MATERIALS AND METHODS

A total of 56 newly diagnosed patients with EGFR-positive GBM were included in our study. The patients were divided into radiotherapy (RT) + temozolomide (TMZ) + nimotuzumab (39 patients) and RT + TMZ (17 patients) groups based on whether or not nimotuzumab was added during RT. Progression-free survival (PFS), overall survival (OS), and toxicities were assessed.

RESULTS

The median follow-up time was 27.9 months (95% confidence interval [CI], 25.1-30.8). The median PFS was 12.4 months (95% CI, 7.8-17.0) and 8.2 months (95% CI, 6.1-10.3) in the 2 groups, respectively, P = .052. The median OS was 27.3 months (95% CI, 19.0-35.6) and 16.7 months (95% CI, 11.1-22.2), respectively, P = .018. In patients with unmethylated O6-methylguanine-DNA methyltransferase (MGMT) promoter, the PFS and OS were significantly better in patients treated with nimotuzumab than in those without nimotuzumab (median PFS: 19.3 vs 6.7 months, P = .001; median OS: 20.2 vs 13.8 months, P = .026). During the treatment period, no statistically significant difference in toxicity was noted between the 2 groups.

CONCLUSION

Our retrospective cohort study suggests the efficacy of Nimotuzumab combined with concurrent RT with TMZ in patients with newly diagnosed EGFR-positive GBM, and specifically those with unmethylated MGMT promoter. Further prospective studies are warranted to validate our findings. Besides, nimotuzumab demonstrated good safety and tolerability.

CMTM6 knockdown prevents glioma progression by inactivating the mTOR pathway

Background

Gliomas in the adult brain are complicated and aggressive with a poor prognosis. Gene therapy is a recent alternative glioma treatment. We sought to explore the mechanism of chemokine-like factor (CKLF) MARVEL transmembrane domain-containing 6 (CMTM6) in glioma.

Methods

The Cancer Genome Atlas database reports that CMTM6 is expressed in tumors and glioma tissue. CMTM6 expression in glioma tissues and cells was detected and its relationship with clinical pathology was analyzed. Short hairpin ribonucleic acid-CMTM6 lentivirus was transfected into U87 and U251 cells to evaluate malignant glioma cells. Using the biological website (https://string-db.org/cgi/input.pl?Sessionid) and reference retrieval, the pathway that interacted with CMTM6 and related to glioma was identified. The level of the mammalian target of rapamycin pathway-related proteins was detected. Functional rescue experiments were performed using the combination of mTOR activator MHY1485 and the knockdown CMTM6. The growth of xenograft tumors was observed and Ki67-positive expression was determined.

Results

CMTM6 upregulation in gliomas was associated with a poor prognosis. CMTM6 expression was notably higher in gliomas. After the knockdown of CMTM6, the proliferation, invasion, and migration of U87 and U251 cells were inhibited, and the apoptosis rate was increased. Knocking down CMTM6 inactivated the mTOR pathway. The activation of mTOR pathway reversed the inhibitory effects of CMTM6 knockdown on glioma cell behaviors. CMTM6 knockdown reduced tumor volume, body mass, and Ki67-positive expression.

Conclusions

The knockdown of CMTM6 inhibited the activation of mTOR pathway and prevented the malignant episodes of glioma cells.

Safety and efficacy of depatuxizumab mafodotin in Japanese patients with malignant glioma: A nonrandomized, phase 1/2 trial

INTELLANCE‐J was a phase 1/2 study of a potent antibody‐drug conjugate targeting epidermal growth factor receptor (EGFR), depatuxizumab mafodotin (Depatux‐M), as a second‐ or first‐line therapy, alone or combined with chemotherapy or chemoradiotherapy in 53 Japanese patients with World Health Organization (WHO) grade III/IV glioma. In second‐line arms, patients with EGFR‐amplified recurrent WHO grade III/IV glioma received Depatux‐M plus chemotherapy (temozolomide) or Depatux‐M alone regardless of EGFR status. In first‐line arms, patients with newly diagnosed WHO grade III/IV glioma received Depatux‐M plus chemoradiotherapy. The study was halted following lack of survival benefit with first‐line Depatux‐M in the global trial INTELLANCE‐1. The primary endpoint was 6‐month progression‐free survival (PFS) in patients with EGFR‐amplified tumors receiving second‐line Depatux‐M plus chemotherapy. Common nonocular treatment‐emergent adverse events (TEAEs) with both second‐line and first‐line Depatux‐M included lymphopenia (42%, 33%, respectively), thrombocytopenia (39%, 47%), alanine aminotransferase increase (29%, 47%), and aspartate aminotransferase increase (24%, 60%); incidence of grade ≥3 TEAEs was 66% and 53%, respectively. Ocular side effects (OSEs) occurred in 93% of patients receiving second‐line Depatux‐M plus chemotherapy and all patients receiving second‐line Depatux‐M alone or first‐line Depatux‐M plus chemoradiotherapy. Most OSEs were manageable with dose modifications and concomitant medications. The 6‐month PFS estimate was 25.6% (95% confidence interval [CI] 11.4‒42.6), and median PFS was 2.1 months (95% CI 1.9‒3.9) with second‐line Depatux‐M plus chemotherapy in the EGFR‐amplified subgroup. This study showed acceptable safety profile of Depatux‐M alone or plus chemotherapy/chemoradiotherapy in Japanese patients with WHO grade III/IV glioma. The study was registered at ClinicalTrials.gov (NCT02590263).

Inferred Ancestral Origin of Cancer Cell Lines Associates with Differential Drug Response

Disparities between risk, treatment outcomes and survival rates in cancer patients across the world may be attributed to socioeconomic factors. In addition, the role of ancestry is frequently discussed. In preclinical studies, high-throughput drug screens in cancer cell lines have empowered the identification of clinically relevant molecular biomarkers of drug sensitivity; however, the genetic ancestry from tissue donors has been largely neglected in this setting. In order to address this, here, we show that the inferred ancestry of cancer cell lines is conserved and may impact drug response in patients as a predictive covariate in high-throughput drug screens. We found that there are differential drug responses between European and East Asian ancestries, especially when treated with PI3K/mTOR inhibitors. Our finding emphasizes a new angle in precision medicine, as cancer intervention strategies should consider the germline landscape, thereby reducing the failure rate of clinical trials.

Elucidating the mechanisms of Temozolomide resistance in gliomas and the strategies to overcome the resistance

Temozolomide (TMZ) is a first-choice alkylating agent inducted as a gold standard therapy for glioblastoma multiforme (GBM) and astrocytoma. A majority of patients do not respond to TMZ during the course of their treatment. Activation of DNA repair pathways is the principal mechanism for this phenomenon that detaches TMZ-induced O-6-methylguanine adducts and restores genomic integrity. Current understanding in the domain of oncology adds several other novel mechanisms of resistance such as the involvement of miRNAs, drug efflux transporters, gap junction's activity, the advent of glioma stem cells as well as upregulation of cell survival autophagy. This review describes a multifaceted account of different mechanisms responsible for the intrinsic and acquired TMZ-resistance. Here, we summarize different strategies that intensify the TMZ effect such as MGMT inhibition, development of novel imidazotetrazine analog, and combination therapy; with an aim to incorporate a successful treatment and increased overall survival in GBM patients.

Oxidative Stress Activated by Sorafenib Alters the Temozolomide Sensitivity of Human Glioma Cells Through Autophagy and JAK2/STAT3-AIF Axis

The development of temozolomide (TMZ) resistance in glioma leads to poor patient prognosis. Sorafenib, a novel diaryl urea compound and multikinase inhibitor, has the ability to effectively cross the blood-brain barrier. However, the effect of sorafenib on glioma cells and the molecular mechanism underlying the ability of sorafenib to enhance the antitumor effects of TMZ remain elusive. Here, we found that sorafenib could enhance the cytotoxic effects of TMZ in glioma cells in vitro and in vivo. Mechanistically, the combination of sorafenib and TMZ induced mitochondrial depolarization and apoptosis inducing factor (AIF) translocation from mitochondria to nuclei, and this process was dependent on STAT3 inhibition. Moreover, the combination of sorafenib and TMZ inhibited JAK2/STAT3 phosphorylation and STAT3 translocation to mitochondria. Inhibition of STAT3 activation promoted the autophagy-associated apoptosis induced by the combination of sorafenib and TMZ. Furthermore, the combined sorafenib and TMZ treatment induced oxidative stress while reactive oxygen species (ROS) clearance reversed the treatment-induced inhibition of JAK2/STAT3. The results indicate that sorafenib enhanced the temozolomide sensitivity of human glioma cells by inducing oxidative stress-mediated autophagy and JAK2/STAT3-AIF axis.

Role of glioblastoma stem cells in cancer therapeutic resistance: a perspective on antineoplastic agents from natural sources and chemical derivatives

Glioblastoma (GBM) is the highest-grade form of glioma, as well as one of the most aggressive types of cancer, exhibiting rapid cellular growth and highly invasive behavior. Despite significant advances in diagnosis and therapy in recent decades, the outcomes for high-grade gliomas (WHO grades III-IV) remain unfavorable, with a median overall survival time of 15–18 months. The concept of cancer stem cells (CSCs) has emerged and provided new insight into GBM resistance and management. CSCs can self-renew and initiate tumor growth and are also responsible for tumor cell heterogeneity and the induction of systemic immunosuppression. The idea that GBM resistance could be dependent on innate differences in the sensitivity of clonogenic glial stem cells (GSCs) to chemotherapeutic drugs/radiation prompted the scientific community to rethink the understanding of GBM growth and therapies directed at eliminating these cells or modulating their stemness. This review aims to describe major intrinsic and extrinsic mechanisms that mediate chemoradioresistant GSCs and therapies based on antineoplastic agents from natural sources, derivatives, and synthetics used alone or in synergistic combination with conventional treatment. We will also address ongoing clinical trials focused on these promising targets. Although the development of effective therapy for GBM remains a major challenge in molecular oncology, GSC knowledge can offer new directions for a promising future.

Poly(p-phenylenevinylene) nanoparticles modified with antiEGFRvIII for specific glioblastoma therapy

Glioblastoma is the most common primary brain cancer and it is nearly impossible to remove the entire tumor with surgery or a single drug. EGFRvIII is the most frequent genetic change associated with glioblastoma, so EGFRvIII-based targeting therapies provide promise for treating glioblastoma. Herein, poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene] (PPV) was used as the core to prepare a conjugated polymer nanoparticle (PPVN) modified with anti-EGFRvIII (PPVN-A) that exhibited high ROS generation ability under white light irradiation. PPVN-A could target EGFRvIII-overexpressed tumor cells and damaged more than 90% of tumor cells with the light illumination while PPVN without modification exhibited no obvious cytotoxicity toward these cells under the same condition. Thus, the photodynamic treatment of glioblastoma cells using PPVN-A could be achieved, indicating the potential of anti-EGFRvIII-modified nanoparticles as a therapeutic material for treating glioblastoma in clinic.

Current and Future Therapeutic Targets: A Review on Treating Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) continues to be a global public health burden even after a tremendous development in its treatment. It is a heterogeneous cancer of upper aero-digestive tract. The contemporary strategy to treat cancer is the use of anticancer drugs against proteins possessing abnormal expression. Targeted chemotherapy was found successful in HNSCC, but, there is still a stagnant improvement in the survival rates and high recurrence rates due to undesirable chemotherapy reactions, non-specificity of drugs, resistance against drugs and drug toxicity on non-cancerous tissues and cells. Various extensive studies lead to the identification of drug targets capable to treat HNSCC effectively. The current review article gives an insight into these promising anticancer targets along with knowledge of drugs under various phases of development. In addition, new potential targets that are not yet explored against HNSCC are also described. We believe that exploring and developing drugs against these targets might prove beneficial in treating HNSCC.

Temozolomide, Gemcitabine, and Decitabine Hybrid Nanoconjugates: From Design to Proof-of-Concept (PoC) of Synergies toward the Understanding of Drug Impact on Human Glioblastoma Cells

This paper emphasizes the synthesis of novel hybrid drug nanoparticles (Hyb-D-AuNPs) based on gold-temozolomide (TMZ) complexes combined with gemcitabine (GEM) and decitabine (DAC) to improve the efficiency and reduce the resistance of U87 malignant glial cells against TMZ. All products were evaluated by several spectroscopic techniques (Raman, UV-Vis) and transmission electron microscopy (TEM). Besides, for therapeutic purposes, the effect of these nanoparticles on cell proliferation and toxicity was evaluated, which clearly showed a synergic action of TMZ and GEM. Through the analysis of the exometabolome by nuclear magnetic resonance (NMR), the metabolic changes in the culture medium were measured in glial cells. Moreover, these nanoparticles are especially appropriated to the thermal destruction of cancer in the case of photothermal therapy due to their photothermal heating properties. This study presents an original chemical approach that it could play a central role in the field of nanomedicine, with novel perspectives for the development of new drugs and active targeting in glioblastoma multiforme (GBM) cancer therapy.

Considering the Experimental use of Temozolomide in Glioblastoma Research

Temozolomide (TMZ) currently remains the only chemotherapeutic component in the approved treatment scheme for Glioblastoma (GB), the most common primary brain tumour with a dismal patient's survival prognosis of only ~15 months. While frequently described as an alkylating agent that causes DNA damage and thus-ultimately-cell death, a recent debate has been initiated to re-evaluate the therapeutic role of TMZ in GB. Here, we discuss the experimental use of TMZ and highlight how it differs from its clinical role. Four areas could be identified in which the experimental data is particularly limited in its translational potential: 1. transferring clinical dosing and scheduling to an experimental system and vice versa; 2. the different use of (non-inert) solvent in clinic and laboratory; 3. the limitations of established GB cell lines which only poorly mimic GB tumours; and 4. the limitations of animal models lacking an immune response. Discussing these limitations in a broader biomedical context, we offer suggestions as to how to improve transferability of data. Finally, we highlight an underexplored function of TMZ in modulating the immune system, as an example of where the aforementioned limitations impede the progression of our knowledge.

Clinical efficacy and safety of nimotuzumab plus chemotherapy in patients with advanced colorectal cancer: a retrospective analysis

Objective

To compare the clinical efficacy and safety of nimotuzumab combined with chemotherapy versus chemotherapy alone as first-line treatment for advanced colorectal cancer (ACRC).

Method

We retrospectively enrolled patients with ACRC treated with nimotuzumab plus chemotherapy (n = 40) or chemotherapy alone (n = 44). Responses were evaluated according to the Response Evaluation Criteria in Solid Tumors and adverse events according to the Common Terminology Criteria for Adverse Events 3.0.

Results

The objective overall response rate and disease control rate were higher in the combined-treatment group (55.0% vs 36.4% and 85.0% vs 75.0%, respectively), but the differences were not significant. There was no significant difference in median progression-free survival or median survival time between the combined-treatment and chemotherapy-alone groups (9.89 vs 7.86 months and 22.32 vs 18.10 months, respectively). There was no significant difference in adverse events between the two groups.

Conclusion

Nimotuzumab combined with chemotherapy had similar efficacy and safety to chemotherapy alone in patients with ACRC. The efficacy and safety of the combined treatment should be further studied in a randomized multicenter trial with a larger number of patients with ACRC.

Mitochondrial dysfunction contributes to Rapamycin-induced apoptosis of Human Glioblastoma Cells - A synergistic effect with Temozolomide

Mammalian target of rapamycin (mTOR) is upregulated in a high percentage of glioblastomas. While a well-known mTOR inhibitor, rapamycin, has been shown to reduce glioblastoma survival, the role of mitochondria in achieving this therapeutic effect is less well known. Here, we examined mitochondrial dysfunction mechanisms that occur with the suppression of mTOR signaling. We found that, along with increased apoptosis, and a reduction in transformative potential, rapamycin treatment significantly affected mitochondrial health. Specifically, increased production of reactive oxygen species (ROS), depolarization of the mitochondrial membrane potential (MMP), and altered mitochondrial dynamics were observed. Furthermore, we verified the therapeutic potential of rapamycin-induced mitochondrial dysfunction through co-treatment with temzolomide (TMZ), the current standard of care for glioblastoma. Together these results demonstrate that the mitochondria remain a promising target for therapeutic intervention against human glioblastoma and that TMZ and rapamycin have a synergistic effect in suppressing glioblastoma viability, enhancing ROS production, and depolarizing MMP.

Administration of nimotuzumab combined with cisplatin plus 5-fluorouracil as induction therapy improves treatment response and tolerance in patients with locally advanced nasopharyngeal carcinoma receiving concurrent radiochemotherapy: a multicenter randomized controlled study

Background

Nimotuzumab (NTZ) is an anti-EGFR monoclonal antibody. However,the effect of targeted drugs combined with induction therapy in locally advanced nasopharyngeal carcinoma remains unclear. The aim of this study is to investigate the safety and efficacy of NTZ combined with cisplatin plus 5-fluorouracil (PF) as induction regimen in locally advanced nasopharyngeal carcinoma (NPC) patients receiving concurrent radiochemotherapy.

Methods

This was a multicenter randomized controlled study performed in eight Guangxi hospitals in 2015–2017. Eligible patients with NPC were randomized into nimotuzumab/PF (NPF group) and docetaxel/PF (DPF group) regimens, respectively, as induction therapy. After 2 cycles of induction therapy, all patients received cisplatin and concurrent intensity modulated radiation therapy (IMRT). Then, the two groups were compared for safety and efficacy.

Results

A total of 118 patients with stage III-IVa NPC were assessed, with 58 and 60 in the NPF and DPF groups, respectively. Compared with DPF treatment, NPF induction therapy showed a more pronounced effect on cervical lymph nodes (P = 0.036), with higher response rate (RR) (81% vs 60%). Compared with the DPF group, the NPF group showed significantly reduced leukopenia, neutropenia and gastrointestinal reactions (all P < 0.05); rash only appeared in the NPF group, but all cases were grade 1. During concurrent treatment with radiotherapy and chemotherapy, the NPF group showed better tolerance to radiotherapy and chemotherapy; neutropenia, anemia, gastrointestinal reactions, oral mucositis and radiation dermatitis in the NPF group were significantly reduced (P < 0.05). The expression rate of EGFR was 94.9% (112/118). Compared with the DPF group, patients with EGFR expression in the NPF group showed better response (77.8% vs 63.0%, P = 0.033).

Conclusion

For locally advanced NPC patients receiving follow-up cisplatin and IMRT, nimotuzumab/PF for induction therapy has better lymph node response rate and milder adverse reactions than the DPF regimen. In addition, the patients have better tolerance in subsequent concurrent radiotherapy and chemotherapy; however, long-term efficacy needs further follow-up evaluation.

Trial registration

The registration number of the clinical trial is ChiCTR-OIC-16008201 and retrospectively registered on March 31, 2016.

Metabolic Abnormalities in Glioblastoma and Metabolic Strategies to Overcome Treatment Resistance

Glioblastoma (GBM) is the most common and aggressive primary brain tumor and is nearly universally fatal. Targeted therapy and immunotherapy have had limited success in GBM, leaving surgery, alkylating chemotherapy and ionizing radiation as the standards of care. Like most cancers, GBMs rewire metabolism to fuel survival, proliferation, and invasion. Emerging evidence suggests that this metabolic reprogramming also mediates resistance to the standard-of-care therapies used to treat GBM. In this review, we discuss the noteworthy metabolic features of GBM, the key pathways that reshape tumor metabolism, and how inhibiting abnormal metabolism may be able to overcome the inherent resistance of GBM to radiation and chemotherapy.

YAP promotes multi-drug resistance and inhibits autophagy-related cell death in hepatocellular carcinoma via the RAC1-ROS-mTOR pathway

Background

Multi-drug resistance is the major cause of chemotherapy failure in hepatocellular carcinoma (HCC). YAP, a critical effector of the Hippo pathway, has been shown to contribute to the progression, metastasis and invasion of cancers. However, the potential role of YAP in mediating drug resistance remains obscure.

Methods

RT-qPCR and western blot were used to assess YAP expression in HCC cell lines. CCK-8 assays, flow cytometry, a xenograft tumour model, immunochemistry and GFP-mRFP-LC3 fusion proteins were utilized to evaluate the effect of YAP on multi-drug resistance, intracellular ROS production and the autophagy of HCC cells in vitro and in vivo. Autophagy inhibitor and rescue experiments were carried out to elucidate the mechanism by which YAP promotes chemoresistance in HCC cells.

Results

We found that BEL/FU, a typical HCC cell line with chemoresistance, exhibited overexpression of YAP. Moreover, the inhibition of YAP by shRNA or verteporfin conferred the sensitivity of BEL/FU cells to chemotherapeutic agents through autophagy-related cell death in vitro and in vivo. Mechanistically, YAP silencing significantly enhanced autophagic flux by increasing RAC1-driven ROS, which contributed to the inactivation of mTOR in HCC cells. In addition, the antagonist of autophagy reversed the enhanced effect of YAP silencing on cell death under treatment with chemotherapeutic agents.

Conclusion

Our findings suggested that YAP upregulation endowed HCC cells with multi-drug resistance via the RAC1-ROS-mTOR pathway, resulting in the repression of autophagy-related cell death. The blockade of YAP may serve as a promising novel therapeutic strategy for overcoming chemoresistance in HCC.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0898-7) contains supplementary material, which is available to authorized users.

Efficacy and safety of nimotuzumab in addition to radiotherapy and temozolomide for cerebral glioblastoma: a phase II multicenter clinical trial

Background: Nimotuzumab is a humanized anti-epidermal growth factor receptor (EGFR) antibody that has shown preclinical and clinical anticancer activity in cerebral glioblastoma multiforme (GBM). We conducted a phase II, single-arm, multicenter clinical trial to evaluate the benefit of adding nimotuzumab to current standard chemo-radiotherapy for patients with GBM with positive EGFR expression.

Methods: Newly diagnosed patients with histologically proven single supratentorial GBM and epidermal growth factor receptor (EGFR) positive expressions were recruited. All patients were treated with nimotuzumab, administered once a week intravenously for 6 weeks in addition to radiotherapy with concomitant and adjuvant temozolomide after surgery. The primary endpoints were overall survival (OS) and progression-free survival (PFS). Secondary objectives included objective response rate (ORR) and toxicity.

Results: A total of 39 patients were enrolled and 36 patients were evaluated for efficacy. The ORR at the end of RT was 72.2%. Median OS and PFS were 24.5 and 11.9 months. The 1-year OS and PFS rates were 83.3% and 49.3%. The 2-year OS and PFS rates were 51.1% and 29.0%. O (6)-methylquanine DNA methyl-tranferase (MGMT) expression is known to affect the efficacy of chemotherapy and status of its expression is examined. No significant correlation between treatment outcomes and MGMT status was found. Most frequent treatment-related toxicities were mild to moderate and included constipation, anorexia, fatigue, nausea, vomiting, and leucopenia.

Conclusions: Our study show that nimotuzumab in addition to standard treatment is well tolerable and has increased survival in newly diagnosed GBM patients with EGFR positive expression.

Time profile of nimotuzumab for enhancing radiosensitivity of the Eca109 cell line

The aim of the present study was to investigate the ability of Nimotuzumab to increase radiosensitivity at different delivery times in the mixed cancer cell line Eca109, to determine the optimal delivery time. Cultured Eca109 cells were classified into five groups: Control with no treatment (O group); irradiation without Nimotuzumab treatment (R group); treatment with Nimotuzumab 24 h prior to or after irradiation (24NR or 24RN group, respectively); and Nimotuzumab combined with irradiation simultaneously (NR group). Following cells reaching the logarithmic-growth phase, cell survival after exposure to Nimotuzumab was evaluated using an MTT assay; thereafter, the 50% inhibitory concentration (IC₅₀) of the cell line was calculated. Cell-survival curves were generated using a colony-forming assay. Flow cytometry analysis was used to detect apoptosis rates and cell-cycle distribution. The expression level of epidermal growth factor receptor was measured in Eca109 cells with western blotting. Growth inhibition was only observed 72 h after exposure to Nimotuzumab. The IC₅₀ was 768 µg/ml. At a dose of 0.2 IC₅₀ or 0.3 IC₅₀, the sensitization enhancement ratio of radiosensitivity was highest in the 24NR group. Nimotuzumab enhanced radiation-induced apoptosis in Eca109 cells, with the optimal delivery time at 24 h prior to irradiation (P=0.035). The concentration of Nimotuzumab administered was directly proportional to the increase in radiosensitivity of the cells.

The effect of the mTOR inhibitor rapamycin on glucoCEST signal in a preclinical model of glioblastoma

PURPOSE

The mammalian target of rapamycin is an enzyme that regulates cell metabolism and proliferation. It is up-regulated in aggressive tumors, such as glioblastoma, leading to increased glucose uptake and consumption. It has been suggested that glucose CEST signals reflect the delivery and tumor uptake of glucose. The inhibitor rapamycin (sirolimus) has been applied as a glucose deprivation treatment; thus, glucose CEST MRI could potentially be useful for monitoring the tumor responses to inhibitor treatment.

METHODS

A human U87-EGFRvIII xenograft model in mice was studied. The mice were treated with a mammalian target of Rapamycin inhibitor, rapamycin. The effect of the treatment was evaluated in vivo with dynamic glucose CEST MRI.

RESULTS

Rapamycin treatment led to significant increases (P < 0.001) in dynamic glucose-enhanced signal in both the tumor and contralateral brain as compared to the no-treatment group, namely a maximum enhancement of 3.7% ± 2.3% (tumor, treatment) versus 1.9% ± 0.4% (tumor, no-treatment), 1.7% ± 1.1% (contralateral, treatment), and 1.0% ± 0.4% (contralateral, no treatment). Dynamic glucose-enhanced contrast remained consistently higher in treatment versus no-treatment groups for the duration of the experiment (17 min). This was confirmed with area-under-curve analysis.

CONCLUSION

Increased glucose CEST signal was found after mammalian target of Rapamycin inhibition treatment, indicating potential for dynamic glucose-enhanced MRI to study tumor response to glucose deprivation treatment.

Akt and mTORC1 signaling as predictive biomarkers for the EGFR antibody nimotuzumab in glioblastoma

Glioblastoma (GB) is the most frequent primary brain tumor in adults with a dismal prognosis despite aggressive treatment including surgical resection, radiotherapy and chemotherapy with the alkylating agent temozolomide. Thus far, the successful implementation of the concept of targeted therapy where a drug targets a selective alteration in cancer cells was mainly limited to model diseases with identified genetic drivers. One of the most commonly altered oncogenic drivers of GB and therefore plausible therapeutic target is the epidermal growth factor receptor (EGFR). Trials targeting this signaling cascade, however, have been negative, including the phase III OSAG 101-BSA-05 trial. This highlights the need for further patient selection to identify subgroups of GB with true EGFR-dependency. In this retrospective analysis of treatment-naïve samples of the OSAG 101-BSA-05 trial cohort, we identify the EGFR signaling activity markers phosphorylated PRAS40 and phosphorylated ribosomal protein S6 as predictive markers for treatment efficacy of the EGFR-blocking antibody nimotuzumab in MGMT promoter unmethylated GBs. Considering the total trial population irrespective of MGMT status, a clear trend towards a survival benefit from nimotuzumab was already detectable when tumors had above median levels of phosphorylated ribosomal protein S6. These results could constitute a basis for further investigations of nimotuzumab or other EGFR- and downstream signaling inhibitors in selected patient cohorts using the reported criteria as candidate predictive biomarkers.

Metabolic targeting of EGFRvIII/PDK1 axis in temozolomide resistant glioblastoma

Glioblastomas are characterized by amplification of EGFR. Approximately half of tumors with EGFR over-expression also express a constitutively active ligand independent EGFR variant III (EGFRvIII). While current treatments emphasize surgery followed by radiation and chemotherapy with Temozolomide (TMZ), acquired chemoresistance is a universal feature of recurrent GBMs. To mimic the GBM resistant state, we generated an in vitro TMZ resistant model and demonstrated that dichloroacetate (DCA), a metabolic inhibitor of pyruvate dehydrogenase kinase 1 (PDK1), reverses the Warburg effect. Microarray analysis conducted on the TMZ resistant cells with their subsequent treatment with DCA revealed PDK1 as its sole target. DCA treatment also induced mitochondrial membrane potential change and apoptosis as evidenced by JC-1 staining and electron microscopic studies. Computational homology modeling and docking studies confirmed DCA binding to EGFR, EGFRvIII and PDK1 with high affinity. In addition, expression of EGFRvIII was comparable to PDK1 when compared to EGFR in GBM surgical specimens supporting our in silico prediction data. Collectively our current study provides the first in vitro proof of concept that DCA reverses the Warburg effect in the setting of EGFRvIII positivity and TMZ resistance leading to GBM cytotoxicity, implicating cellular tyrosine kinase signaling in cancer cell metabolism.

Epidermal growth factor receptor and EGFRvIII in glioblastoma: signaling pathways and targeted therapies

Amplification of epidermal growth factor receptor (EGFR) and its active mutant EGFRvIII occurs frequently in glioblastoma (GBM). While EGFR and EGFRvIII play critical roles in pathogenesis, targeted therapy with EGFR-tyrosine kinase inhibitors (TKIs) or antibodies has only shown limited efficacy in patients. Here we discuss signaling pathways mediated by EGFR/EGFRvIII, current therapeutics, and novel strategies to target EGFR/EGFRvIII-amplified GBM.

MRI features can predict EGFR expression in lower grade gliomas: A voxel-based radiomic analysis

OBJECTIVE

To identify the magnetic resonance imaging (MRI) features associated with epidermal growth factor (EGFR) expression level in lower grade gliomas using radiomic analysis.

METHODS

270 lower grade glioma patients with known EGFR expression status were randomly assigned into training (n=200) and validation (n=70) sets, and were subjected to feature extraction. Using a logistic regression model, a signature of MRI features was identified to be predictive of the EGFR expression level in lower grade gliomas in the training set, and the accuracy of prediction was assessed in the validation set.

RESULTS

A signature of 41 MRI features achieved accuracies of 82.5% (area under the curve [AUC] = 0.90) in the training set and 90.0% (AUC = 0.95) in the validation set. This radiomic signature consisted of 25 first-order statistics or related wavelet features (including range, standard deviation, uniformity, variance), one shape and size-based feature (spherical disproportion), and 15 textural features or related wavelet features (including sum variance, sum entropy, run percentage).

CONCLUSIONS

A radiomic signature allowing for the prediction of the EGFR expression level in patients with lower grade glioma was identified, suggesting that using tumour-derived radiological features for predicting genomic information is feasible.

KEY POINTS

• EGFR expression status is an important biomarker for gliomas. • EGFR in lower grade gliomas could be predicted using radiogenomic analysis. • A logistic regression model is an efficient approach for analysing radiomic features.

Treatment outcome of nimotuzumab plus chemotherapy in advanced cancer patients: a single institute experience

Nimotuzumab is a humanized anti-EGFR IgG1 monoclonal antibody and demonstrates a better safety profile than other anti-EGFR antibodies due to its intermediate affinity. Since it was approved in China for the treatment of nasopharyngeal cancer (NPC), it has been widely used in NPC and in many clinical trials for other cancer types. However, the optimal dose and administration frequency of nimotuzumab that should be used and which kind of cancer patients will be more benefited from nimotuzumab is still unknown. In this retrospective study, 205 advanced cancer patients with colorectal cancer, esophageal cancer, head and neck cancer, gastric cancer, non-small cell lung cancer, or other cancers from mainland China, treated with nimotuzumab in combination with chemotherapy, were enrolled. Over 60% of these patients received nimotuzumab > 6 doses and ≥ 400 mg/week as maintenance therapy. It was well tolerated in real-life patients. This report demonstrates that age, sex and previous treatment might be potential predictive factors for survival, and patients received nimotuzumab > 6 doses and > 200 mg/week might benefit more from nimotuzumab therapy. Using these factors for stratification analysis may form a predictive differential clinical strategy for nimotuzumab to maximize the benefit in patients with different epithelial tumors.

Temozolomide resistance in glioblastoma multiforme

Temozolomide (TMZ) is an oral alkylating agent used to treat glioblastoma multiforme (GBM) and astrocytomas. However, at least 50% of TMZ treated patients do not respond to TMZ. This is due primarily to the over-expression of O⁶-methylguanine methyltransferase (MGMT) and/or lack of a DNA repair pathway in GBM cells. Multiple GBM cell lines are known to contain TMZ resistant cells and several acquired TMZ resistant GBM cell lines have been developed for use in experiments designed to define the mechanism of TMZ resistance and the testing of potential therapeutics. However, the characteristics of intrinsic and adaptive TMZ resistant GBM cells have not been systemically compared. This article reviews the characteristics and mechanisms of TMZ resistance in natural and adapted TMZ resistant GBM cell lines. It also summarizes potential treatment options for TMZ resistant GBMs.

Targeting autophagy to sensitive glioma to temozolomide treatment

Temozolomide (TMZ), an alkylating agent, is widely used for treating primary and recurrent high-grade gliomas. However, the efficacy of TMZ is often limited by the development of resistance. Recently, studies have found that TMZ treatment could induce autophagy, which contributes to therapy resistance in glioma. To enhance the benefit of TMZ in the treatment of glioblastomas, effective combination strategies are needed to sensitize glioblastoma cells to TMZ. In this regard, as autophagy could promote cell survival or autophagic cell death, modulating autophagy using a pharmacological inhibitor, such as chloroquine, or an inducer, such as rapamycin, has received considerably more attention. To understand the effectiveness of regulating autophagy in glioblastoma treatment, this review summarizes reports on glioblastoma treatments with TMZ and autophagic modulators from in vitro and in vivo studies, as well as clinical trials. Additionally, we discuss the possibility of using autophagy regulatory compounds that can sensitive TMZ treatment as a chemotherapy for glioma treatment.