Nimotuzumab as a radiosensitizing agent in the treatment of high grade glioma: challenges and opportunities

A natural compound melatonin enhances the effects of Nimotuzumab via inhibiting EGFR in glioblastoma

Sleep disorders are prevalent and debilitating symptoms in primary brain tumor patients, notably those receiving radiation therapy. Nevertheless, the relationship between sleep disorders, melatonin - a circadian rhythm regulatory hormone, and gliomas is underexplored. Melatonin exhibits various biological functions, one of them being anti-tumor activity. In the context of gliomas, often overexpressing EGFR, the humanized monoclonal antibody Nimotuzumab targets this marker. Our research discovered that variations in circadian rhythm significantly influence tumor growth in mice through impacting melatonin secretion. Harnessing proteogenomic, we identified that melatonin could inhibit the phosphorylation of EGFR and its downstream effectors, key elements in angiogenesis and tumor progression. Building on structural simulations, we propose that melatonin may amplify Nimotuzumab's anti-glioma efficacy by inhibiting EGFR TK dimerization. This proposition was validated in our in vitro and in vivo studies where melatonin synergistically augmented cytotoxicity and apoptosis in Nimotuzumab-treated glioma cells. Thus, melatonin shows promise as a beneficial addition to Nimotuzumab treatment in glioma patients.

Nimotuzumab Combined With Irradiation Enhances the Inhibition to the HPV16 E6-Promoted Growth of Cervical Squamous Cell Carcinoma

Human papillomavirus (HPV) 16 E6 has been proved to increase the radiosensitivity and lead to the EGFR overexpression in cervical cancer cells. In this study, to investigate the inhibition of nimotuzumab-mediated EGFR blockade combined with radiotherapy, we established a C33A cervical squamous cell line overexpressed HPV16-E6 and a nude mouse model bearing these cell lines. The CCK-8 assay was used to detect the effects of various treatments on the proliferation of C33A cells. Flow cytometry was used to detect the rates of apoptosis and cell cycle arrest. Gene transcription and protein expression were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. Immunohistochemical staining was used to evaluate protein expression in tumor tissue. We revealed that E6-overexpressing C33A cells grew faster and were more sensitive to radiotherapy than control cells in vitro and in vivo. The expression levels of EGFR, as well as those of downstream signaling molecules AKT and ERK 1/2, were significantly upregulated in C33A cells that overexpressed E6. We observed that nimotuzumab combined with radiotherapy could enhance the inhibition of C33A cell growth induced by E6, both in vitro and in vivo. We also observed enhanced effect after combination on G2/M cell cycle arrest and apoptosis in E6-overexpressing C33A cells. Furthermore, the combined therapy of nimotuzumab and radiation remarkably reduced the protein expression levels of EGFR, AKT, ERK 1/2 in vitro, and in vivo. In conclusion, HPV16 E6 expression is positively correlated with levels of EGFR, AKT, and ERK 1/2 protein expression. The combined treatment with nimotuzumab and radiotherapy to enhance radiosensitivity in E6-positive cervical squamous cell carcinoma was related to enhanced G2/M cell cycle arrest and caspase-related apoptosis.

Nimotuzumab for Patients With Inoperable Cancer of the Head and Neck

EGFR activation induces cell proliferation, neoformation of blood vessels, survival, and metastasis of the cancer cells. Nimotuzumab is an engineered, intermediate affinity anti-EGFR antibody, that apart from other drugs in its class, is very safe and does not cause hypomagnesemia or grade 3–4 cutaneous rash. The antibody inhibits cell proliferation and angiogenesis, activates natural killer cells, stimulates dendritic cell maturation, and induces cytotoxic T cells. Nimotuzumab restores MHC-I expression on tumor cells, hindering one of the EGFR immune-escape ways. The antibody has been extensively studied in 7 clinical trials, concurrently with irradiation or irradiation plus chemotherapy in subjects with inoperable head and neck tumors. Nimotuzumab was safe and efficacious in unfit patients receiving irradiation alone and in subjects treated with cisplatin and radiotherapy. In patients with locally advanced squamous cell carcinomas of the head and neck, nimotuzumab in combination with low dose cisplatin and radiotherapy was superior to cisplatin and radiotherapy in progression free survival, disease free survival, and locoregional tumor control.

Physiological functions of Wilms' tumor 1-associating protein and its role in tumourigenesis

The Wilms' tumor-associated gene WT1 encodes a tumor suppressor gene, which is implicated in renal differentiation and development of adult urogenital system. Wilms' tumor 1-associating protein (WTAP) is initially identified as a nuclear protein that specifically interacts with WT1 in both in vitro and in vivo assays. WTAP is ubiquitously expressed in different tissues and various growth periods, and its expression is involved in cell cycle, RNA splicing and stabilization, N6-methyladenosine RNA modification, cell proliferation, and apoptosis as well as embryonic development. In the present review, we aimed to summarize the functions of WTAP in various physiological and pathological processes, in particular with regard to the current knowledge about the role of WTAP in tumorigenesis of different cancers.

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.

Safety and efficacy of nimotuzumab with concurrent chemoradiotherapy in unresectable locally advanced squamous cell carcinoma of head and neck: An Indian rural hospital experience

Context:

Nimotuzumab is the only anti-epidermal growth factor receptor monoclonal antibody which can be safely added to concurrent chemoradiotherapy (CRT) to improve efficacy in the management of unresectable, locally advanced squamous cell carcinoma of head and neck (LA-SCCHN). However, the evidence available on this is limited.

Aims:

We retrospectively investigated efficacy and safety of nimotuzumab when combined with chemoradiation for LA-SCCHN.

Settings and Design:

Hospital records of 39 patients from January 2012 to December 2016 diagnosed with locally advanced (Stage III-IVb), unresectable SCCHN, and treated with concurrent CRT with weekly nimotuzumab were reviewed retrospectively after fulfilling the inclusion/exclusion criteria.

Subjects and Methods:

Tumor response was calculated as per response evaluation criteria in solid tumors criteria 1.1. Association of tumor response with independent variables was assessed. Overall survival (OS) and progression-free survival (PFS) were calculated. All patients were assessed for toxicity as per common terminology criteria for adverse events Common Terminology Criteria for Adverse Events v 4.0 (U.S. Department of health and human services, National Institutes of Health, National Cancer Institute).

Results:

At 6 months after completion of treatment, objective response rate was 97.44% with 26 (66.67%) patients attaining Complete response (CR), 12 (30.77%) patients with Partial response (PR), and one patient (2.56%) had stable disease. Subgroup analysis did not show a significant association of tumor response with independent factors. OS at 1 and 2-year was 100% and 72.9%, while PFS at 1 and 2-year was 87% and 54.40%. The incidence of Grade I, II, III, and IV toxicity was 30%, 18.18%, 41.82%, and 10%, respectively. No grade V toxicity was observed. Common adverse events observed were mucositis (33.64%), skin reaction (24.55%), neutropenia (20.91%), vomiting (18.18%), and diarrhea (2.73%).

Conclusions:

Nimotuzumab is an efficacious and safe option when added to concurrent CRT in unresectable, LA-SCCHN.

Patient and treatment factors associated with survival among pediatric glioblastoma patients: A Surveillance, Epidemiology, and End Results study

Glioblastoma (GBM) is a rare malignancy in children. The United States Surveillance, Epidemiology, and End Results (SEER) database allows large-scale analyses of clinical characteristics and prognostic features. We used it to study patients aged <20 years with histologically confirmed GBM (2000-2010) and examined the relationship between patient demographics, tumor characteristics, patterns of treatment, and outcomes. The primary outcome was disease-specific survival. 302 subjects were identified, with median age 11 years. Median follow-up was 32 months (95% CI 27-39). 34.4% had gross total resection (GTR). 61% underwent radiation after surgery (17% of subjects <3 years, 67% of those aged 4-19 years). Median survival and 2-year survival rates were 20 months and 46.9%, respectively. In multivariate analyses, age, tumor location, extent of resection, and year of diagnosis were significantly associated with the primary outcome. Compared to those aged 0-4 years, subjects aged 5-9 years and 10-14 years had higher risk of mortality. Infratentorial tumor location (HR 2.0, 95% CI 1.2-3.3, p = 0.007) and subtotal resection (HR 2.04, 95% CI 1.4-3.0, p < 0.001) were associated with increased mortality. Later year of diagnosis was significantly associated with decreased risk of death (HR 0.93, 95% CI 0.9-0.99, p = 0.031). There was no association between sex, race, region, or tumor size and the primary outcome. Repeat analyses examining all-cause mortality identified the same risk factors as for CNS cancer-specific mortality. Younger age, supratentorial location, GTR, and later year of diagnosis were associated with improved survival.

Comparative analysis of the effects of a sphingosine kinase inhibitor to temozolomide and radiation treatment on glioblastoma cell lines

Glioblastoma multiforme (GBM) exhibits high resistance to the standard treatment of temozolomide (TMZ) combined with radiotherapy, due to its remarkable cell heterogeneity. Accordingly, there is a need to target alternative molecules enhancing specific GBM autocrine or paracrine mechanisms and amplifying the effect of standard treatment. Sphingosine 1-phosphate (S1P) is such a lipid target molecule with an important role in cell invasion and proliferation. Sphingosine kinase inhibitors (SKI) prevent S1P formation and induce increased production of reactive oxygen species (ROS), which may potentiate radiation cytotoxicity. We analyzed the effect of SKI singular versus combined treatments with TMZ and radiation on 2 human GBM cell lines characterized by a lack of MGMT expression and low or high expression of the anti-oxidant enzyme, glutathione peroxidase 1 (GPx1). Effects were drug concentration-, cell line-dependent and partly ROS-mediated. Clonogenic survival assay demonstrates that SKI was more effective than TMZ in increasing the sensitivity of U87 cells, which express low GPx1 amount, to a 2 Gy X-ray dose. Addition of both SKI and TMZ drastically decreased U87 cells survival compared with the combination temozolomide/radiation. SKI less effectively than TMZ sensitized LN229 cells to the 2 Gy X-ray dose. Its combination to TMZ in absence of irradiation was as efficient as TMZ combination with X-ray. We provide first evidence for SKI as an alternative or complementary treatment to TMZ, and for efficient combinations of low doses of drugs and X-ray. These may help as novel bi-modal and tri-modal therapies to contend with GBM heterogeneity.

Expression of programmed cell death-ligand 1 and its correlation with clinical outcomes in gliomas

Programmed cell death-ligand 1(PD-L1) was expressed in various malignancies, and interaction with its receptor programmed cell death 1 (PD-1) often contributed to immune evasion of tumor cells. In this study, we explored the expression of PD-L1 and its correlation with clinical outcomes in gliomas.

Clinicopathological data of 229 patients with gliomas was collected. PD-L1 expression was assessed by tissue-microarray-based immunohistochemistry. Over 5% of tumor cells with cytoplasm or membrane staining was defined as PD-L1 positive expression. The associations of clinicopathological features with overall survival (OS) and disease-free survival (DFS) were analyzed by univariate analysis and multivariate analysis was further performed by Cox regression model.

PD-L1 positive expression was observed in 51.1% gliomas patients and no significant association was verified between PD-L1 expression and pathological grade in 229 gliomas patients. However, PD-L1 expression rate was 49.2%, 53.7% and 68.8% for grade II, III and IV in 161 patients with those ≥ 12 months of OS, respectively. Although no significant discrepancies was displayed, there was a certain degree of differences between PD-L1 expression and pathological grade (49.2% vs. 53.7% vs. 68.8%, P = 0.327). Univariate analysis showed that PD-L1 expression was significantly associated with poor OS in the patients with long-time survival or follow up (OS ≥ 12 months) (P = 0.018), especially in patients with grade IV (P = 0.019). Multivariate analysis revealed that a strong tendency towards statistical significance was found between PD-L1 expression and poor OS (P = 0.081).

In gliomas patients with long-time survival or follow up, PD-L1 positive expression could indicate the poor prognosis and it is possible that immunotherapy targeting PD-L1 pathway needed to be determined in the further study.

WTAP Expression Predicts Poor Prognosis in Malignant Glioma Patients

Wilms' tumor 1-associating protein (WTAP) interacts with the Wilms' tumor 1 gene. Although originally classified as a tumor suppressor, WTAP was later found to be over-expressed in glioblastoma which is regarded as a grade IV astrocytoma. However, the expression in other glioma grades and the relationship between WTAP expression and the prognosis of glioma patients are still unknown. In this study, we investigated WTAP expression in 169 different types of glioma cases using western blot analysis and immunohistochemistry assay. Further, we evaluated the association of WTAP expression with clinicopathological characteristics using chi-square test and Spearman's correlation test. We used univariate and multivariate Cox regression analyses to evaluate the independency of diferent WTAP expression. Then, the survival curves were calculated using the Kaplan-Meier method. Results showed that WTAP was over-expressed in glioma tissues, and the expression was closely correlated with glioma grade. Moreover, high WTAP expression was correlated with poor postoperative survival in glioma patients. WTAP may serve as a novel prognostic marker.

Effect and mechanism of peroxisome proliferator-activated receptor-γ on the drug resistance of the U-87 MG/CDDP human malignant glioma cell line

Peroxisome proliferator-activated receptor-γ (PPAR-γ) is important in tumor differentiation, proliferation and apoptosis. However, the effect and mechanism of PPAR-γ on the promotion of cisplatin sensitivity in glioma cells remain to be elucidated. The present study established cisplatin-resistant U-87 MG/CDDP cell lines and U-87 MG/CDDP cell lines overexpressing PPAR-γ. With upregulated expression of PPAR-γ, the sensitivity of cancer cells to cisplatin was increased. Flow cytometry revealed that the intracellular content of rhodamine-123 was increased, expression of P-glycoprotein was downregulated, cell cycle was arrested in G0/G1 phase, apoptosis and oxidative stress was increased, levels of intracellular thymidylate synthase, glutathione and transforming growth factor-β1 were decreased, expression levels of multidrug resistance related gene (MDR), multidrug resistance-associated protein and glutothionine S-transferase-π were downregulated, expression levels of cell proliferation and apoptosis associated genes, including survivin and B-cell lymphoma-2, were downregulated, p53, p21 and caspase-3/8 were significantly upregulated, phosphorylation of extracellular signal-regulated kinase and small mothers against decapentaplegic 2 were downregulated, and the transcriptional activities of Twist and nuclear factor (erythroid-derived 2)-like 2 were significantly reduced. The results suggested that upregulation of PPAR-γ in the U-87 MG/DDP cells increased cisplatin sensitivity, and the underlying mechanisms included the regulation of MDR and apoptosis associated genes, which increased the intracellular accumulation of the drug, inhibited cell proliferation and promoted cell apoptosis.

Nimotuzumab enhances radiation sensitivity of NSCLC H292 cells in vitro by blocking epidermal growth factor receptor nuclear translocation and inhibiting radiation-induced DNA damage repair

Background

The epidermal growth factor receptor (EGFR) signaling pathway plays a significant role in radiation resistance. There is evidence that EGFR nuclear translocation is associated with DNA double-strand breaks (DSB) repair. Nimotuzumab has shown the effect of radiosensitization in various cancer cells, but little is known about the relationship between nimotuzumab and EGFR nuclear translocation in non-small cell lung cancer (NSCLC) cell lines. In this study, we selected two NSCLC cell lines, namely, H292 (with high EGFR expression) and H1975 (with low EGFR expression) and explored the mechanisms underlying radiation sensitivity.

Methods

MTT assay, clonogenic survival assay, and flow cytometry were performed separately to test cell viability, radiation sensitivity, cell cycle distribution, and apoptosis. Protein γ-H2AX, DNA-PK/p-DNA-PK, and EGFR/p-EGFR expression were further compared both in the cytoplasm and the nucleus with the western blot.

Results

Nimotuzumab reduced the viability of H292 cells and sensitized H292 cells to ionizing radiation. The radiation sensitivity enhancement ratio (SER) was 1.304 and 1.092 for H292 and H1975 cells, respectively. H292 cells after nimotuzumab administration were arrested at the G0/G1 phase in response to radiation. Apoptosis was without statistical significance in both cell lines. γ-H2AX formation in the combination group (nimotuzumab and radiation) increased both in the cytoplasm and the nucleus along with the decreased expression of nuclear EGFR/p-EGFR and p-DNA-PK in H292 cells (P<0.05) that was more significant than that in H1975 cells.

Conclusion

Our research revealed a possible mechanism to explain the radiosensitivity in H292 cells. Nimotuzumab decreased the radiation-induced activation of DNA-PK by blocking EGFR nuclear translocation and impairing DNA DSB repair, thus enhancing radiosensitivity in H292 cells. Because these results represent early research, the matters of how γ-H2AX and DNA-PK dynamically change simultaneously with nuclear EGFR and the best time to administer nimotuzumab will require further exploration.

Profile of nimotuzumab in the treatment of high-grade glioma

High-grade gliomas (HGG) are extremely aggressive lesions and represent the most common primary malignant brain tumors without an effective therapy. Standard treatment for HGG usually includes surgery followed by radiotherapy and chemotherapy. However, the prognosis of patients with HGG remains dismal. We review the humanized epidermal growth factor receptor (EGFR) and the major EGFR target drugs in HGG treatments, focusing on the EGFR antibody nimotuzumab as a new therapeutic strategy in HGG. We found that nimotuzumab with or without radiotherapy, chemotherapy in newly diagnosed or recurrent HGG, such as glioblastoma multiforme (GBM), anaplastic astrocytomas (AA), and diffuse intrinsic pontine glioma (DIPG), might improve the response rate or the survival time. In conclusion, nimotuzumab is a very well-tolerated drug with acceptable toxicity, and it may have promising value in the combination treatment. As a result, multiple center randomized controlled Phase III clinical trials need to be conducted to confirm the efficacy and toxicity for nimotuzumab in HGG.