Personalized Radiation Oncology: Epidermal Growth Factor Receptor and Other Receptor Tyrosine Kinase Inhibitors

Clinical Efficacy of Endoscopic Infratentorial Supracerebellar Approach for Pineal Region Tumors: A Retrospective Case-Control Study

Tumors in the pineal region are deep, with complex surrounding anatomy, adjacent to important blood vessels and nerve structures, and surgical resection is difficult and risky. In this paper, we reviewed the literature to understand the epidemiology and clinical manifestations of pineal region tumors in the country and study the clinical indications, related problems, and successful experiences of patients with pineal region tumors treated by the transtentorial-superior approach. The clinical data of 80 patients with pineal region tumors were selected as the retrospective research objects and divided into the control group and the treatment group, with 40 cases in each group, according to the random number table method. The control group was treated using the endoscopic transtentorial approach (Poppen approach), while the treatment group was treated with the endoscopic supratentorial approach (Krause approach). The inflammatory factors, inflammatory stress response, postoperative neurological dysfunction, clinical efficacy, and poor prognosis were observed and compared between the two groups. Tumor resection and recurrence were used to compare the clinical outcomes of tumors in the pineal region. The extent of surgical resection was 100% higher in both groups, and the treatment group was comparable to the control group. The prognosis of patients after the operation was poor. Nausea and vomiting, visual disturbance, upper vision paralysis, and ataxia in the treatment group were significantly lower than those in the control group, with no statistical significance (P > 0.05). At the same time, the bone window can be reduced to reduce trauma and provide a certain reference for patients to choose a safe and complete resection method.

The PI3K/Akt/mTOR pathway in lung cancer; oncogenic alterations, therapeutic opportunities, challenges, and a glance at the application of nanoparticles

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Lung cancer is the most common and deadliest human malignancies.

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The alterations of PI3K/Akt/mTOR pathway are related to lung cancer progression.

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PI3K axis regulates proliferation, apoptosis, metastasis, and EMT of lung cancer.

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Agents inhibiting components of PI3K axis diminish lung tumor growth and invasion.

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Low efficacy and off-target toxicity could be improved by nanoparticle application.

Lung cancer is the leading cause of cancer-related mortality worldwide. Although the PI3K/Akt/mTOR signaling pathway has recently been considered as one of the most altered molecular pathways in this malignancy, few articles reviewed the task. In this review, we aim to summarize the original data obtained from international research laboratories on the oncogenic alterations in each component of the PI3K/Akt/mTOR pathway in lung cancer. This review also responds to questions on how aberrant activation in this axis contributes to uncontrolled growth, drug resistance, sustained angiogenesis, as well as tissue invasion and metastatic spread. Besides, we provide a special focus on pharmacologic inhibitors of the PI3K/Akt/mTOR axis, either as monotherapy or in a combined-modal strategy, in the context of lung cancer. Despite promising outcomes achieved by using these agents, however, the presence of drug resistance as well as treatment-related adverse events is the other side of the coin. The last section allocates a general overview of the challenges associated with the inhibitors of the PI3K pathway in lung cancer patients. Finally, we comment on the future research aspects, especially in which nano-based drug delivery strategies might increase the efficacy of the therapy in this malignancy.

Growth factor receptor and β1 integrin signaling differentially regulate basal clonogenicity and radiation survival of fibroblasts via a modulation of cell cycling

Cell adhesion to extracellular matrix proteins mediates resistance to radio- and chemotherapy by activating integrin signaling. In addition, mutual and cooperative interactions between integrin and growth factor receptor signaling contribute to the cellular radiation response. Here, we investigate to which extend the crosstalk between β1 integrins and growth factor receptor signaling determines the cellular radiation response of fibroblasts by assessing clonogenic survival and cell cycling. By utilizing growth factor signaling competent and either β1 integrin wildtype GD25β1A fibroblasts or β1 integrin mutant, signaling incompetent GD25β1B fibroblasts, we show basal clonogenic survival to depend on growth factor receptor but not integrin signaling. Our data further suggest the cooperation between β1 integrins and growth factor receptors to be critical for enhancing the radiation-induced G2/M cell cycle block leading to improved clonogenic radiation survival. By pharmacological inhibition of EGFR and PI3K, we additionally show that the essential contribution of EGFR signaling to radiogenic G2/M cell cycle arrest depends on the co-activation of the β1 integrin signaling axis, but occurs independent of PI3K. Taken together, elucidation of the signaling circuitry underlying the EGFR/β1 integrin crosstalk may support the development of advanced molecular targeted therapies for radiation oncology.

Value of functional in-vivo endpoints in preclinical radiation research

BACKGROUND

Cancer research faces the problem of high rates of clinical failure of new treatment approaches after positive preclinical data. We hypothesize that a major confounding factor to this problem in radiooncology is the choice of the preclinical endpoint.

METHODS

We present a comprehensive re-evaluation of large-scale preclinical in-vivo data on fractionated irradiation alone or simultaneously with Epidermal Growth Factor Receptor inhibition. Taking the permanent local tumour control assay as a gold standard, we evaluated different tumour volume dependent endpoints that are widely used for preclinical experiments.

RESULTS

The analysis showed the highest correlations between volume related and local tumour control endpoints after irradiation alone. For combined treatments, wide inter-tumoural variations were observed with reduced correlation between the endpoints. Evaluation of growth delay per Gray (GD/Gy) based on two or more dose levels showed closest correlation with local tumour control dose 50% (TCD₅₀).

CONCLUSIONS

GD/Gy with at least two dose groups correlates with TCD₅₀, but cannot replace the latter as the goldstandard.

Rab25-Mediated EGFR Recycling Causes Tumor Acquired Radioresistance

Tumor acquired radioresistance remains as the major limit in cancer radiotherapy (RT). Rab25, a receptor recycling protein, has been reported to be enhanced in tumors with aggressive phenotype and chemotherapy resistance. In this study, elevated Rab25 expression was identified in an array of radioresistant human cancer cell lines, in vivo radioresistant xenograft tumors. Clinical investigation confirmed that Rab25 expression was also associated with a worse prognosis in patients with lung adenocarcinoma (LUAD) and nasopharyngeal carcinoma (NPC). Enhanced activities of EGFR were observed in both NPC and LUAD radioresistant cells. Rab25 interacts with EGFR to enhance EGFR recycling to cell surface and to decrease degradation in cytoplasm. Inhibition of Rab25 showed synergized radiosensitivity with reduced aggressive phenotype. This study provides the clinical and experimental evidence that Rab25 is a potential therapeutic target to alleviate the hyperactive EGFR signaling and to prevent RT-acquired tumor resistance in patients with LUAD and NPC.

Design, Synthesis and Antitumor Activity of Quinazoline Derivatives Bearing 2,3-Dihydro-indole or 1,2,3,4-Tetrahydroquinoline

Background:

Cancer continues to pose a great problem and burden on society despite new treatment options. While surgery, radiotherapy, and chemotherapy have led to major improvements in patient prognosis, newer treatments are needed to more effectively manage this disease in its advanced stage. Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase (RTK), which is catalytically active and under tight regulatory control. Dysregulation of its activity is strongly associated with tumorigenesis and cancer patients with altered EGFR activity tend to have a more aggressive disease, associated with a poor clinical prognosis. The family of EGFR has been intensively studied due to its strong influence on the formulation and deterioration of carcinoma. Thus, it is a good strategy that design anticancer agents by inhibiting the EGFR pathway.

Methods:

We group to obtain the six series compounds (8a-f, 9a-f, 10a-f, 11a-f, 12a-b and 13a-d). Hence we disclosed the design, synthesis and antitumor activity of novel quinazoline analogues against EGFR overexpression cancer cells A549 (human lung cancer), HepG-2 (human liver cancer), MCF-7 (human breast cancer) and PC-3 (human prostate cancer) and as well as the inhibitory on EGFR kinase. Moreover, apoptosis by acridine orange single staining and docking studies were presented in this paper as well.

Results:

Six series of quinazoline derivatives bearing 2,3-dihydro-indole or 1,2,3,4-tetrahydroquinoline (8a-f, 9a-f, 10a-f, 11a-f, 12a-b and 13a-d) were designed, synthesized and evaluated for the half maximal inhibitory concentration (IC50) values against four cancer cell lines (A549, HepG-2, MCF-7 and PC-3). Thirty target compounds showed moderate to excellent (1.49 - 50 µM) cytotoxicity activity against one or several cancer cell lines. The compound 13a showed the best activity against A549, HepG- 2, MCF-7 and PC-3 cancer cell lines, with the IC50 values of 1.49 ± 0.17 µM, 2.90 ± 0.24 µM, 1.85 ± 0.19 µM, 3.30 ± 0.22 µM, respectively. What’s more, the secondary amines were introduced to the target compounds to improve the water-soluble. The results showed that the compounds were beneficial to the cytotoxicity activity. Furthermore, the results prompted us that this series of compounds may be a kind of potential epidermal growth factor receptor (EGFR) kinase inhibitors.

Conclusion:

Six series of quinazoline derivatives bearing 2,3-dihydro-indole or 1,2,3,4- tetrahydroquinoline moiety (8a-f, 9a-f, 10a-f, 11a-f, 12a-b and 13a-d) were designed, synthesized and evaluated for the IC50 values of cytotoxicity against four cancer cell lines (A549, HepG-2, MCF-7 and PC-3). Thirty synthesized compounds showed moderate to excellent cytotoxicity activity against the different cancer cells. Especially, the compound 13a exerted antitumor effects in a dosage-dependent manner and the IC50 values of compound 13a were 1.49 µM, 2.90 µM, 1.85 µM and 3.30 µM against A549, HepG-2, MCF-7 and PC-3, respectively. From the antitumor activity data show that the compounds possessed selectivity for A549 and MCF-7 cancer cell lines. It meant that the compounds had better treatment effect on lung cancer and breast cancer. On the whole, the compounds substituted by 1,2,3,4-tetrahydroquinoline at C-4 position of quinazoline and (S)-tetrahydrofuran-3-ol at C-8 position of quinazoline were beneficial to the cytotoxicity activity. From the result of acridine orange (AO) single staining which indicated the compound 13a could induce apoptosis of A549 cells. From the result of Docking Studies, we hypothesized that the C-4 position of quinazoline were substituted by 2,3-dihydro-indole or 1,2,3,4-tetrahydroquinoline with the equal influence of the cytotoxicity activity. Overall, the results prompted us that this series of compounds may be a kind of potential EGFR kinase inhibitors.

Carbonic Anhydrase IX (CAIX), Cancer, and Radiation Responsiveness

Carbonic anhydrase IX has been under intensive investigation as a therapeutic target in cancer. Studies demonstrate that this enzyme has a key role in pH regulation in cancer cells, allowing these cells to adapt to the adverse conditions of the tumour microenviroment. Novel CAIX inhibitors have shown efficacy in both in vitro and in vivo pre-clinical cancer models, adversely affecting cell viability, tumour formation, migration, invasion, and metastatic growth when used alone. In co-treatments, CAIX inhibitors may enhance the effects of anti-angiogenic drugs or chemotherapy agents. Research suggests that these inhibitors may also increase the response of tumours to radiotherapy. Although many of the anti-tumour effects of CAIX inhibition may be dependent on its role in pH regulation, recent work has shown that CAIX interacts with several of the signalling pathways involved in the cellular response to radiation, suggesting that pH-independent mechanisms may also be an important basis of its role in tumour progression. Here, we discuss these pH-independent interactions in the context of the ability of CAIX to modulate the responsiveness of cancer to radiation.

Epidermal Growth Factor Receptor Mutations in Lung Adenocarcinomas: A Single Center Study from Iran

Introduction: Lung cancer is the fifth leading tumor in Iran, and while its incidence remains relatively low, it has been increasing steadily. Targeted therapies have brought new hope to patients with non small cell lung cancer (NSCLC). The epidermal growth factor receptor (EGFR) gene is the prototype member of the type I receptor tyrosine kinase (TK) family and plays a pivotal role in cell proliferation and differentiation. Studies from Asian countries have revealed a higher frequency of EGFR mutations than in the West. The aim of this study was to measure the frequency and type of EGFR mutations in a group of Iranian patients with lung adenocarcinomas. Methods: Formalin fixed paraffin embedded (FFPE) lung adenocarcinoma tissues from 103 Iranian patients were sequentially tested for EGFR mutations by the polymerase chain reaction (PCR) followed by direct nucleotide sequencing of exons 18, 19, 20, and 21. Patient’s demographics and other clinical details were obtained from the medical records of hospitals affiliated to Iran University of Medical Sciences, Tehran, Iran. Statistical analyses were performed with SPSS v.20. Results: EGFR mutations were detected in 25/103 (24.3%) patients. The most frequent was an exon 21 point mutation (L858R) (15 patients; 60%), followed by one in exon 19 (10 patients; 40%). The frequency of EGFR mutations in never-smoker patients was significantly higher than in smokers (68% versus 32%; p < 0. 01). Conclusion: EGFR mutation frequency is higher than in the West but lower than in East Asian and almost equal to reported rates for Indian and North African populations. Smoking is negatively associated with EGFR mutations in Iranian lung adenocarcinomas.

Selective MET Kinase Inhibition in MET-Dependent Glioma Models Alters Gene Expression and Induces Tumor Plasticity

The receptor tyrosine kinase (RTK) MET represents a promising tumor target in a subset of glioblastomas. Most RTK inhibitors available in the clinic today, including those inhibiting MET, affect multiple targets simultaneously. Previously, it was demonstrated that treatment with cabozantinib (MET/VEGFR2/RET inhibitor) prolonged survival of mice carrying orthotopic patient-derived xenografts (PDX) of the MET-addicted glioblastoma model E98, yet did not prevent development of recurrent and cabozantinib-resistant tumors. To exclude VEGFR2 inhibition-inflicted blood-brain barrier normalization and diminished tumor distribution of the drug, we have now investigated the effects of the novel MET-selective inhibitor Compound A in the orthotopic E98 xenograft model. In vitro, Compound A proved a highly potent inhibitor of proliferation of MET-addicted cell lines. In line with its target selectivity, Compound A did not restore the leaky blood-brain barrier and was more effective than cabozantinib in inhibiting MET phosphorylation in vivo Compound A treatment significantly prolonged survival of mice carrying E98 tumor xenografts, but did not prevent eventual progression. Contrasting in vitro results, the Compound A-treated xenografts displayed high levels of AKT phosphorylation despite the absence of phosphorylated MET. Profiling by RNA sequencing showed that in vivo transcriptomes differed significantly from those in control xenografts.Implications: Collectively, these findings demonstrate the plasticity of paracrine growth factor receptor signaling in vivo and urge for prudency with in vitro drug-testing strategies to validate monotherapies. Mol Cancer Res; 15(11); 1587-97. ©2017 AACR.

Biomarkers of resistance to radiation therapy: a prospective study in cervical carcinoma

Background

Clinical parameters and proteins have recently been suggested as possible causes of radiotherapy (RT) resistance in cervical carcinoma (CC). The objective of the present study was to validate prognostic biomarkers of radiation resistance.

Methods

The present prospective study included patients undergoing RT with curative intent for histologically proven locally advanced squamous cell CC. Tissues and blood samples were systematically collected before RT initiation. Immuno-histochemistry was performed (IGF-IR α and β, GAPDH, HIF-1 alpha, Survivin, GLUT1, CAIX, hTERT and HKII). Response to radiation was assessed through tumour response 3 months after RT completion, through overall survival (OS) and through progression-free survival (PFS).

Results

One hundred forty nine patients with a mean age of 46 years were included, with FIGO IIB (n = 53) and FIGO IIIB (n = 96) CCs. 61 patients were treated with exclusive RT + brachytherapy and 88 underwent chemo-radiotherapy + brachytherapy. Our findings suggest an association between hemoglobin level (Hb) (>11 g/dL) and 3 months complete response (p = 0.02). Hb level < 11 g/dL was associated with decreased PFS (p = 0.05) and OS (p = 0.08). Overexpression of IGF-1R β was correlated with a decreased OS (p = 0.007). Overexpression of GLUT1 was marginally correlated with reduced OS (p = 0.05). PFS and OS were significantly improved in patients undergoing chemoradiation versus exclusive radiotherapy (PFS: p = 0.04; OS: p = 0.01).

Conclusions

IGF-1R β overexpression and Hb level (≤11 g/dl) were associated with poor prognosis, and thus appear to be possible interesting biomarkers of radiation resistance. Our results corroborate previous pre-clinical studies suggesting IGF-1R and hypoxia to be part of the biological pathways leading to radio-resistance.

The Challenges Faced in Developing Novel Drug Radiation Combinations in Non-small Cell Lung Cancer

Lung cancer is the most common cancer diagnosed in the UK. Outcomes for patients with this disease remain poor and new strategies to treat this disease require investigation. One potential option is to combine novel agents with radiotherapy in clinical studies. Here we discuss some of the important issues to consider when combining novel agents with radiotherapy, together with potential solutions as discussed at a recent Clinical Translational Radiotherapy Group (CTRad) workshop.