Combining proton or photon irradiation with epothilone B : An in vitro study of cytotoxicity in human cancer cells

Recently, the use of proton beams in cancer therapy is becoming widespread, and tumour treatment modalities combining radiosensitizing chemical agents with irradiation are under investigation in order to achieve greater tumour local control and reduce the probability of distant failures. The combined treatment modality of radiation and the clinically relevant microtubule-stabilizing compound epothilone B is a promising approach for anticancer therapy. In the present study, we investigated the cytotoxicity of a spread out Bragg peak (SOBP) proton beam, as well as of 6 MV photons, in human glioblastoma (U251 MG) and lung adenocarcinoma (A549) cells pretreated for 24 h, or not, with epothilone B at concentrations of 0.125 and 0.075 nM respectively. Proton irradiation was performed at the middle position of an actively modulated SOBP (12\u201318 cm depth in water) and cell survival was evaluated by a colony forming assay. For both cell lines, survival curves after proton or photon irradiation alone showed linear quadratic behaviour with proton RBE (relative biological effectiveness), compared with photons at 10% survival, of 1.5 \ub1 0.2. Treatment of cells with epothilone B at subnanomolar concentration has an anticlonogenic effect. Furthermore, differently from the results found with radiation alone, the survival curves for the combined treatment epothilone B\u2013radiation showed a linear trend and analysis of the interaction of the two cytotoxic agents indicated a slight synergism. These data provide a radiobiological basis for further experiments, as well as clinical studies

Quality of life in patients with chordomas/chondrosarcomas during treatment with proton beam therapy

Introduction: Health-related quality of life (HQL) parameters have never been tested in patients having chondromas/chondrosarcomas who are being treated with protons. The aim of this study was to document changes in HQL of chordoma/chondrosarcoma patients treated with proton beam radiotherapy. Treatments commenced in September 2011 at CNAO, and HQL studies were initiated in January 2012 for all patients undergoing treatment. Methods: The validated Italian translation of the EORTC QLQ-C30 version 3.0 was used for HQL evaluation. The HQL assessments were made prior to starting radiation and at completion of treatment. Scoring was as per the EORTC manual. As per standard norms, a difference of >10 points in the mean scores was taken to be clinically meaningful. Results: Between January and September 2012, 17 patients diagnosed with chordoma or chondrosarcoma, with a mean \ub1 SD age of 49.5 \ub1 16.4 years, had completed treatment. The involved sites were skull base (n = 12) and sacral/paraspinal (n = 5). The prescribed dose was 70-74 GyE at 2 GyE per fraction, 5 days/week. When comparing pre- and post-treatment scores, neither a clinically meaningful nor a statistically significant change was documented. Conclusions: During treatment, HQL is not adversely affected by protons, allowing normal life despite the long course of treatment. This is an ongoing study and more long-term assessment will help evaluate the actual impact of proton therapy on HQL for these slow-responding tumours

Studio degli effetti dell’uso combinato di fasci terapeutici di particelle cariche e radiosensibilizzanti in cellule tumorali umane coltivate in vitro

Nell\u2019ambito delle terapie oncologiche \ue8 crescente l\u2019interesse per trattamenti che abbinino alle radiazioni l\u2019utilizzo di agenti chimici potenziali radiosensibilizzanti. L\u2019obiettivo di questo tipo di trattamenti \ue8 quello di ottenere un miglior controllo locale del tumore e di ridurre la probabilit\ue0 di formazione di metastasi. In letteratura sono stati pubblicati numerosi studi sull\u2019uso concomitante di fasci terapeutici di fotoni e diversi agenti chimici, ma attualmente ben pochi dati sono disponibili sull\u2019azione combinata di adroni e agenti chimici radiosensibilizzanti. In questo lavoro si descrivono i risultati di uno studio radiobiologico condotto su fasci terapeutici di fotoni e di protoni, ed alcuni dati preliminari relativi a fasci di ioni Carbonio, utilizzando cellule umane tumorali coltivate in vitro, trattate o meno, durante le 24 ore precedenti l\u2019irraggiamento, con il chemioterapico Epothilone B, un agente microtubulo-stabilizzante. I principali obiettivi dello studio sono: - determinare l\u2019efficacia dei fasci di adroni rispetto ai fotoni, per le linee cellulari studiate ( RBE) - studiare la modalit\ue0 di interazione delle diverse radiazioni con Epothilone B per valutare se sia additiva o sinergica. Sono stati utilizzati i fasci terapeutici di adroni di CNAO (Pavia) e di fotoni presso l\u2019Istituto Tumori di Milano. Lo studio \ue8 stato condotto su linee cellulari umane di glioblastoma multiforme (U251MG), adenocarcinoma polmonare a cellule non piccole (A549) e medulloblastoma pediatrico (DAOY). I principali effetti biologici studiati sono il mantenimento della capacit\ue0 proliferativa (sopravvivenza clonogenica), la crescita e l\u2019invasivit\ue0 cellulare. I risultati ottenuti hanno mostrato che: - l\u2019RBE dei protoni dipende fortemente dalla linea cellulare e, per glioblastoma multiforme e per adenocarcinoma polmonare, \ue8 risultata maggiore di 1.1, valore attualmente usato nella pratica clinica. - Il chemioterapico Epothilone B aumenta la citotossicit\ue0 dei fasci di protoni e di fotoni e l\u2019effetto del trattamento combinato \ue8 pi\uf9 che additivo

Initial clinical experience with scanned proton beams at the Italian National Center for Hadrontherapy (CNAO)

We report the initial toxicity data with scanned proton beams at the Italian National Center for Hadrontherapy (CNAO). In September 2011, CNAO commenced patient treatment with scanned proton beams within two prospective Phase II protocols approved by the Italian Health Ministry. Patients with chondrosarcoma or chordoma of the skull base or spine were eligible. By October 2012, 21 patients had completed treatment. Immobilization was performed using rigid non-perforated thermoplastic-masks and customized headrests or body-pillows as indicated. Non-contrast CT scans with immobilization devices in place and MRI scans in supine position were performed for treatment-planning. For chordoma, the prescribed doses were 74 cobalt grey equivalent (CGE) and 54 CGE to planning target volume 1 (PTV1) and PTV2, respectively. For chondrosarcoma, the prescribed doses were 70 CGE and 54 CGE to PTV1 and PTV2, respectively. Treatment was delivered five days a week in 35-37 fractions. Prior to treatment, the patients' positions were verified using an optical tracking system and orthogonal X-ray images. Proton beams were delivered using fixed-horizontal portals on a robotic couch. Weekly MRI incorporating diffusion-weighted-imaging was performed during the course of proton therapy. Patients were reviewed once weekly and acute toxicities were graded with the Common Terminology Criteria for Adverse Events (CTCAE). Median age of patients = 50 years (range, 21-74). All 21 patients completed the proton therapy without major toxicities and without treatment interruption. Median dose delivered was 74 CGE (range, 70-74). The maximum toxicity recorded was CTCAE Grade 2 in four patients. Our preliminary data demonstrates the clinical feasibility of scanned proton beams in Italy

Re-irradiation with carbon ion radiotherapy for pelvic rectal cancer recurrences in patients previously irradiated to the pelvis

Background/Aim: Re-irradiation of locally recurrent rectal cancer poses challenges due to the proximity of critical organs, such as the bowel. This study aimed at evaluating the safety and efficacy of re-irradiation with Carbon Ion Radiotherapy (CIRT) in rectal cancer patients with local recurrence. Patients and Methods: Between 2014 and 2018, 14 patients were treated at the National Center of Oncological Hadrontherapy (CNAO Foundation) with CIRT for locally recurrent rectal cancer. Results: All patients concluded the treatment. No G≥3 acute/late reaction nor pelvic infections were observed. The 1-year and 2-year local control rates were, 78% and 52%, respectively, and relapse occurred close to the bowel in 6 patients. The 1-year and 2-year overall survival rates were 100% and 76.2% each; while the 1-year and 2-year metastasis free survival rates were 64.3% and 43%. Conclusion: CIRT as re-irradiation for locally recurrent rectal cancer emerges as a safe and valid treatment with an acceptable rate of morbidity of surrounding healthy tissue

Treatment of loco-regional recurrence of nasopharyngeal carcinoma in a non-endemic area: oncologic outcomes, morbidity, and proposal of a prognostic nomogram

Introduction: The study assessed outcomes and toxicities of different treatment modalities for local and/or regional recurrent nasopharyngeal carcinoma (NPC) in a non-endemic area. Methods: Patients treated with curative intent for recurrent NPC with salvage surgery, photon-based radiotherapy, proton therapy (PT), with or without chemotherapy, at different Italian referral centers between 1998 and 2020 were included. Adverse events and complications were classified according to the Common Terminology Criteria for Adverse Events. Characteristics of the patients, tumors, treatments, and complications are presented along with uni- and multivariate analysis of prognostic factors. A survival predictive nomogram is also provided. Results: A total of 140 patients treated from 1998 to 2020 were retrospectively assessed. Cases with lower age, comorbidity rate, stage, and shorter disease-free interval (DFI) preferentially underwent endoscopic surgery. More advanced cases underwent re-irradiation, fairly distributed between photon-based radiotherapy and PT. Age and DFI were independent factors influencing overall survival. No independent prognostic effect of treatment modality was observed. No significant difference in the morbidity profile of treatments was observed, with 40% of patients experiencing at least one adverse event classified as G3 or higher. Conclusion: Recurrent NPC in a non-endemic area has dissimilar aspects compared to its endemic counterpart, suggesting the need for further studies that can guide the choice of the best treatment modality

Modelling the correlation between EGFr expression and tumour cell radiosensitivity, and combined treatments of radiation and monoclonal antibody EGFr inhibitors

Purpose To estimate the effects of heterogeneity on tumour cell sensitivity to radiotherapy combined with radiosensitizing agents attributable to differences in expression levels of Epidermal Growth Factor Receptor (EGFr). Materials and methods Differences in radiosensitivity are not limited to cells of different cancer histotypes but also occur within the same cancer, or appear during radiotherapy if radiosensitizing drugs are combined with ionizing radiation. A modified biologically effective dose (MBED), has been introduced to account for changes in radiosensitivity parameters (alpha and alpha/beta) rather than changes in dose/fraction or total dose as normally done with standard biologically effective dose (BED). The MBED approach was applied to cases of EGFr over-expression and cases where EGFr inhibitors were combined with radiation. Representative examples in clinical practice were considered. RESULTS: Assuming membrane EGFr over-expression corresponds to reduced radiosensitivity (alphaH = 0.15 Gy-1 and alphaH/betaH = 7.5 Gy) relative to normal radiosensitivity (alpha = 0.2 Gy-1 and alpha/beta = 10 Gy), an increased dose per fraction of 2.42 Gy was obtained through the application of MBED, which is equivalent to the effect of a reference schedule with 30 fractions of 2 Gy. An equivalent hypo-fractionated regime with a dose per fraction of 2.80 Gy is obtained if 25 fractions are set. Dose fractionations modulated according to drug pharmacokinetics are estimated for combined treatments with biological drugs. Soft and strong modulated equivalent hypo-fractionations result from subtraction of 5 or 10 fractions, respectively. CONCLUSIONS: During this computational study, a new radiobiological tool has been introduced. The MBED allows the required dose per fraction to be estimated when tumour radiosensitivity is reduced because EGFr is over-expressed. If radiotherapy treatment is combined with EGFr inhibitors, MBED suggests new treatment strategies, with schedules modulated according to drug pharmacokinetics

Inter-fractional monitoring of 12 C ions treatments: results from a clinical trial at the CNAO facility

The high dose conformity and healthy tissue sparing achievable in Particle Therapy when using C ions calls for safety factors in treatment planning, to prevent the tumor under-dosage related to the possible occurrence of inter-fractional morphological changes during a treatment. This limitation could be overcome by a range monitor, still missing in clinical routine, capable of providing on-line feedback. The Dose Profiler (DP) is a detector developed within the INnovative Solution for In-beam Dosimetry in hadronthErapy (INSIDE) collaboration for the monitoring of carbon ion treatments at the CNAO facility (Centro Nazionale di Adroterapia Oncologica) exploiting the detection of charged secondary fragments that escape from the patient. The DP capability to detect inter-fractional changes is demonstrated by comparing the obtained fragment emission maps in different fractions of the treatments enrolled in the first ever clinical trial of such a monitoring system, performed at CNAO. The case of a CNAO patient that underwent a significant morphological change is presented in detail, focusing on the implications that can be drawn for the achievable inter-fractional monitoring DP sensitivity in real clinical conditions. The results have been cross-checked against a simulation study

A Novel Histone Deacetylase Inhibitor Exhibits Antitumor Activity via Apoptosis Induction, F-Actin Disruption and Gene Acetylation in Lung Cancer

BACKGROUND: Lung cancer is the leading cause of cancer mortality worldwide, yet the therapeutic strategy for advanced non-small cell lung cancer (NSCLC) is limitedly effective. In addition, validated histone deacetylase (HDAC) inhibitors for the treatment of solid tumors remain to be developed. Here, we propose a novel HDAC inhibitor, OSU-HDAC-44, as a chemotherapeutic drug for NSCLC. METHODOLOGY/PRINCIPAL FINDINGS: The cytotoxicity effect of OSU-HDAC-44 was examined in three human NSCLC cell lines including A549 (p53 wild-type), H1299 (p53 null), and CL1-1 (p53 mutant). The antiproliferative mechanisms of OSU-HDAC-44 were investigated by flow cytometric cell cycle analysis, apoptosis assays and genome-wide chromatin-immunoprecipitation-on-chip (ChIP-on-chip) analysis. Mice with established A549 tumor xenograft were treated with OSU-HDAC-44 or vehicle control and were used to evaluate effects on tumor growth, cytokinesis inhibition and apoptosis. OSU-HDAC-44 was a pan-HDAC inhibitor and exhibits 3-4 times more effectiveness than suberoylanilide hydroxamic acid (SAHA) in suppressing cell viability in various NSCLC cell lines. Upon OSU-HDAC-44 treatment, cytokinesis was inhibited and subsequently led to mitochondria-mediated apoptosis. The cytokinesis inhibition resulted from OSU-HDAC-44-mediated degradation of mitosis and cytokinesis regulators Auroroa B and survivin. The deregulation of F-actin dynamics induced by OSU-HDAC-44 was associated with reduction in RhoA activity resulting from srGAP1 induction. ChIP-on-chip analysis revealed that OSU-HDAC-44 induced chromatin loosening and facilitated transcription of genes involved in crucial signaling pathways such as apoptosis, axon guidance and protein ubiquitination. Finally, OSU-HDAC-44 efficiently inhibited A549 xenograft tumor growth and induced acetylation of histone and non-histone proteins and apoptosis in vivo. CONCLUSIONS/SIGNIFICANCE: OSU-HDAC-44 significantly suppresses tumor growth via induction of cytokinesis defect and intrinsic apoptosis in preclinical models of NSCLC. Our data provide compelling evidence that OSU-HDAC-44 is a potent HDAC targeted inhibitor and can be tested for NSCLC chemotherapy