Intensity modulated radiation therapy (IMRT) for sinonasal tumors: a single center long-term clinical analysis

Background: Radiotherapy has a central role in the treatment of sinonasal malignancies, either as postoperative or as primary therapy. To study the efficacy and safety of intensity modulated radiotherapy (IMRT) for sinonasal tumors a single center retrospective evaluation focusing on survival and therapy related toxicity was performed. Methods: One hundred twenty two patients with primary (n = 82) or recurrent (n = 40) malignant sinonasal tumors were treated with intensity modulated radiotherapy between 1999 and 2009 at the University Clinic of Heidelberg and the German Cancer Research Center and retrospectively analyzed. Most patients had adenoid cystic carcinomas (n = 47) or squamous cell carcinoma (n = 26). 99 patients received postoperative radiotherapy. The median total dose was 64 Gy in conventional fractionation (1.8–2 Gy). Overall survival (OS), progression free survival (PFS) and local recurrence free survival (LRFS) rates were calculated using the Kaplan-Meier method. The log-rank test and Fishers Exact test were applied for univariate analysis, Cox-regression was used for multivariate analysis. Results: Median follow up was 36 months. 1-, 3- and 5-year estimated overall survival rates were 90, 70 and 54 % respectively. Median progression free survival and local recurrence free survival was 45 and 63 months respectively. Progression free survival and local recurrence free survival at 1, 3 and 5 years were 76, 57 and 47, and 79, 60 and 51 % respectively. 19 patients (15.5 %) were diagnosed with distant metastases. Univariate analysis revealed significantly improved OS and LRFS for treatment of tumors after primary diagnosis, first series of irradiation and radiation dose ≥60 Gy. Multivariate analysis revealed only treatment in primary situation as an independent prognostic factor for OS and LRFS. Acute CTC grade III mucositis was seen in 5 patients (4.1 %) and CTC grade II dysgeusia in 19 patients (15.6 %). Dysgeusia, dysosmia and ocular toxicity were the most common late adverse events. Conclusions: Our data support the results of previous studies and indicate that intensity modulated radiation therapy (IMRT) represents an effective and safe treatment approach for patients with sinonasal carcinomas

Blockade of MMP14 Activity in Murine Breast Carcinomas: Implications for Macrophages, Vessels, and Radiotherapy

Background: Matrix metalloproteinase (MMP) 14 may mediate tumor progression through vascular and immune-modulatory effects. Methods: Orthotopic murine breast tumors (4T1 and E0771 with high and low MMP14 expression, respectively; n = 5-10 per group) were treated with an anti-MMP14 inhibitory antibody (DX-2400), IgG control, fractionated radiation therapy, or their combination. We assessed primary tumor growth, transforming growth factor β (TGFβ) and inducible nitric oxide synthase (iNOS) expression, macrophage phenotype, and vascular parameters. A linear mixed model with repeated observations, with Mann-Whitney or analysis of variance with Bonferroni post hoc adjustment, was used to determine statistical significance. All statistical tests were two-sided. Results: DX-2400 inhibited tumor growth compared with IgG control treatment, increased macrophage numbers, and shifted the macrophage phenotype towards antitumor M1-like. These effects were associated with a reduction in active TGFβ and SMAD2/3 signaling. DX-2400 also transiently increased iNOS expression and tumor perfusion, reduced tissue hypoxia (median % area: control, 20.2%, interquartile range (IQR) = 6.4%-38.9%; DX-2400: 1.2%, IQR = 0.2%-3.2%, P = .044), and synergistically enhanced radiation therapy (days to grow to 800mm3: control, 12 days, IQR = 9-13 days; DX-2400 plus radiation, 29 days, IQR = 26-30 days, P < .001) in the 4T1 model. The selective iNOS inhibitor, 1400W, abolished the effects of DX-2400 on vessel perfusion and radiotherapy. On the other hand, DX-2400 was not capable of inducing iNOS expression or synergizing with radiation in E0771 tumors. Conclusion: MMP14 blockade decreased immunosuppressive TGFβ, polarized macrophages to an antitumor phenotype, increased iNOS, and improved tumor perfusion, resulting in reduced primary tumor growth and enhanced response to radiation therapy, especially in high MMP14-expressing tumor

A New Peptide Ligand for Targeting Human Carbonic Anhydrase IX, Identified through the Phage Display Technology

Carbonic anhydrase IX (CAIX) is a transmembrane enzyme found to be overexpressed in various tumors and associated with tumor hypoxia. Ligands binding this target may be used to visualize hypoxia, tumor manifestation or treat tumors by endoradiotherapy

Optimization of a Novel Peptide Ligand Targeting Human Carbonic Anhydrase IX

BACKGROUND: Carbonic anhydrase IX (CA IX) is a hypoxia-regulated transmembrane protein over-expressed in various types of human cancer. Recently, a new peptide with affinity for human carbonic anhydrase IX (CaIX-P1) was identified using the phage display technology. Aim of the present study is to characterize the binding site in the sequence of CaIX-P1, in order to optimize the binding and metabolic properties and use it for targeting purposes. METHODOLOGY/PRINCIPAL FINDINGS: Various fragments of CaIX-P1 were synthesized on solid support using Fmoc chemistry. Alanine scanning was performed for identification of the amino acids crucial for target binding. Derivatives with increased binding affinity were radiolabeled and in vitro studies were carried out on the CA IX positive human renal cell carcinoma cell line SKRC 52 and the CA IX negative human pancreatic carcinoma cell line BxPC3. Metabolic stability was investigated in cell culture medium and human serum. Organ distribution and planar scintigraphy studies were performed in Balb/c nu/nu mice carrying subcutaneously transplanted SKRC 52 tumors. The results of our studies clearly identified amino acids that are important for target binding. Among various fragments and derivatives the ligand CaIX-P1-4-10 (NHVPLSPy) was found to possess increased binding potential in SKRC 52 cells, whereas no binding capacity for BxPC3 cells was observed. Binding of radiolabeled CaIX-P1-4-10 on CA IX positive cells could be inhibited by both the unlabeled and the native CaIX-P1 peptide but not by control peptides. Stability experiments indicated the degradation site in the sequence of CaIX-P1-4-10. Biodistribution studies showed a higher in vivo accumulation in the tumor than in most healthy tissues. CONCLUSIONS: Our data reveal modifications in the sequence of the CA IX affine ligand CaIX-P1 that might be favorable for improvement of target affinity and metabolic stability, which are necessary prior to the use of the ligand in clinical approaches

The brain microenvironment mediates resistance in luminal breast cancer to PI3K inhibition through HER3 activation

Although targeted therapies are often effective systemically, they fail to adequately control brain metastases. In preclinical models of breast cancer that faithfully recapitulate the disparate clinical responses in these microenvironments, we observed that brain metastases evade phosphatidylinositide 3-kinase (PI3K) inhibition despite drug accumulation in the brain lesions. In comparison to extracranial disease, we observed increased HER3 expression and phosphorylation in brain lesions. HER3 blockade overcame the resistance of HER2-amplified and/or PIK3CA-mutant breast cancer brain metastases to PI3K inhibitors, resulting in marked tumor growth delay and improvement in mouse survival. These data provide a mechanistic basis for therapeutic resistance in the brain microenvironment and identify translatable treatment strategies for HER2-amplified and/or PIK3CA-mutant breast cancer brain metastases

Long-term survival of cancer patients compared to heart failure and stroke: A systematic review

<p>Abstract</p> <p>Background</p> <p>Cancer, heart failure and stroke are among the most common causes of death worldwide. Investigation of the prognostic impact of each disease is important, especially for a better understanding of competing risks. Aim of this study is to provide an overview of long term survival of cancer, heart failure and stroke patients based on the results of large population- and hospital-based studies.</p> <p>Methods</p> <p>Records for our study were identified by searches of Medline via Pubmed. We focused on observed and relative age- and sex-adjusted 5-year survival rates for cancer in general and for the four most common malignancies in developed countries, i.e. lung, breast, prostate and colorectal cancer, as well as for heart failure and stroke.</p> <p>Results</p> <p>Twenty studies were identified and included for analysis. Five-year observed survival was about 43% for all cancer entities, 40-68% for stroke and 26-52% for heart failure. Five-year age and sex adjusted relative survival was 50-57% for all cancer entities, about 50% for stroke and about 62% for heart failure. In regard to the four most common malignancies in developed countries 5-year relative survival was 12-18% for lung cancer, 73-89% for breast cancer, 50-99% for prostate cancer and about 43-63% for colorectal cancer. Trend analysis revealed a survival improvement over the last decades.</p> <p>Conclusions</p> <p>The results indicate that long term survival and prognosis of cancer is not necessarily worse than that of heart failure and stroke. However, a comparison of the prognostic impact of the different diseases is limited, corroborating the necessity for further systematic investigation of competing risks.</p

Investigation of tumor hypoxia using a two-enzyme system for in vitro generation of oxygen deficiency

<p>Abstract</p> <p>Background</p> <p>Oxygen deficiency in tumor tissue is associated with a malign phenotype, characterized by high invasiveness, increased metastatic potential and poor prognosis. Hypoxia chambers are the established standard model for <it>in vitro </it>studies on tumor hypoxia. An enzymatic hypoxia system (GOX/CAT) based on the use of glucose oxidase (GOX) and catalase (CAT) that allows induction of stable hypoxia for <it>in vitro </it>approaches more rapidly and with less operating expense has been introduced recently. Aim of this work is to compare the enzymatic system with the established technique of hypoxia chamber in respect of gene expression, glucose metabolism and radioresistance, prior to its application for <it>in vitro </it>investigation of oxygen deficiency.</p> <p>Methods</p> <p>Human head and neck squamous cell carcinoma HNO97 cells were incubated under normoxic and hypoxic conditions using both hypoxia chamber and the enzymatic model. Gene expression was investigated using Agilent microarray chips and real time PCR analysis. ¹⁴C-fluoro-deoxy-glucose uptake experiments were performed in order to evaluate cellular metabolism. Cell proliferation after photon irradiation was investigated for evaluation of radioresistance under normoxia and hypoxia using both a hypoxia chamber and the enzymatic system.</p> <p>Results</p> <p>The microarray analysis revealed a similar trend in the expression of known HIF-1 target genes between the two hypoxia systems for HNO97 cells. Quantitative RT-PCR demonstrated different kinetic patterns in the expression of carbonic anhydrase IX and lysyl oxidase, which might be due to the faster induction of hypoxia by the enzymatic system. ¹⁴C-fluoro-deoxy-glucose uptake assays showed a higher glucose metabolism under hypoxic conditions, especially for the enzymatic system. Proliferation experiments after photon irradiation revealed increased survival rates for the enzymatic model compared to hypoxia chamber and normoxia, indicating enhanced resistance to irradiation. While the GOX/CAT system allows independent investigation of hypoxia and oxidative stress, care must be taken to prevent acidification during longer incubation.</p> <p>Conclusion</p> <p>The results of our study indicate that the enzymatic model can find application for <it>in vitro </it>investigation of tumor hypoxia, despite limitations that need to be considered in the experimental design.</p

Screening of a Novel Peptide Targeting the Proteoglycan-Like Region of Human Carbonic Anhydrase IX

The extracellular domain of human carbonic anhydrase IX (CA IX) is extended by a proteoglycan-like region (PGLR). The aim of the present study was the development of novel molecules with specificity for PGLR, which may be used for tumor targeting and imaging. PGLR was chemically synthesized, and phage display biopanning was performed. The identified ligand PGLR-P1 was labeled with 125I and characterized for target binding and metabolic stability. In vitro characterization included kinetic, competition, and internalization studies on CA IX–positive renal cell carcinoma SKRC 52 cells. The CA IX–negative cell lines HEK293 wt and BxPC3 were used as negative controls. In vitro binding experiments revealed an increasing affinity of 125I-PGLR-P1 to SKRC 52 cells but not to negative control HEK293 wt and BxPC3 cells. Internalization studies indicated an exclusive cell membrane binding. Biodistribution analysis demonstrated a higher accumulation in SKRC 52 tumors than in most normal tissues after perfusion. In vivo blocking led to a significant decrease in tumor uptake. Our findings indicate that PGLR-P1 is a promising lead structure for the development of new peptide-based ligands targeting the PGLR of CA IX and reveal challenges that need to be considered for peptide-related molecular imaging

Binding of the Phage Display Derived Peptide CaIX-P1 on Human Colorectal Carcinoma Cells Correlates with the Expression of Carbonic Anhydrase IX

Abstract: Phage display represents an attractive screening strategy for the identification of novel, specific binding ligands that could be used for tumor targeting. Recently, a new peptide (CaIX-P1) with affinity for human carbonic anhydrase IX (CAIX) was identified and evaluated. The aim of the present study is to characterize the properties of CaIX-P1 for targeting human colorectal carcinoma and investigate the correlation of peptide binding with the expression of carbonic anhydrase IX. Human colorectal carcinoma HCT116 and HT29 cells were investigated for CAIX expression using Western Blot analysis. Binding and competition studies of 125 I-radiolabeled CaIX-P1 were performed on HCT116 cells in vitro. FACS analysis and fluorescence microscopy studies were carried out after cell incubation with fluorescein-labeled CaIX-P1 and rhodamine-labeled anti-human CAIX-mAb. Our studies revealed an enhanced in vitro expression of carbonic anhydraseInt. J. Mol. Sci. 2012, 13 13031 IX in HCT116 and HT29 cells with increasing cell density. Binding of 125 I-labeled-CaIX-P