-
[show abstract]
[hide abstract]
ABSTRACT: Previously, arsenic trioxide showed impressive regression rates of acute promyelocytic leukemia. Here, we investigated molecular determinants of sensitivity and resistance of cell lines of different tumor types towards arsenic trioxide. Arsenic trioxide was the most cytotoxic compound among 8 arsenicals investigated in the NCI cell line panel. We correlated transcriptome-wide microarray-based mRNA expression to the IC(50) values for arsenic trioxide by bioinformatic approaches (COMPARE and hierarchical cluster analyses, Ingenuity signaling pathway analysis). Among the identified pathways were signaling routes for p53, integrin-linked kinase, and actin cytoskeleton. Genes from these pathways significantly predicted cellular response to arsenic trioxide. Then, we analyzed whether classical drug resistance factors may also play a role for arsenic trioxide. Cell lines transfected with cDNAs for catalase, thioredoxin, or the anti-apoptotic bcl-2 gene were more resistant to arsenic trioxide than mock vector transfected cells. Multidrug-resistant cells overexpressing the MDR1, MRP1 or BCRP genes were not cross-resistant to arsenic trioxide. Our approach revealed that response of tumor cells towards arsenic trioxide is multi-factorial.
PLoS ONE 01/2012; 7(5):e35584. · 4.09 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Aim of the study is to evaluate the effects of medical and surgical treatment in divers with paranasal sinus barotrauma (PSB) secondary to chronic rhinosinusitis (CRS). In this retrospective, cross-sectional, descriptive study 40 adult divers with CRS were included. Treatment of divers implied a 5-day course of a systemic steroid and a 6-week course of saline nasal irrigations and topical nasal steroid with mometasone in maximal dosage. If symptoms persisted, functional endoscopic sinus surgery (FESS) was performed. Questionnaires included the Sinonasal Outcome Test-20 German Adapted Version (SNOT-20 GAV), dive-related questions (DRQ) and general questions. Questionnaires were completed retrospectively by recalling the symptoms before and after therapy. Forty of 82 divers completed the questionnaires. Mean follow-up was 42 months (range 13-95 months). There was a statistically significant improvement of the Total score (TS) and of every subscore, except the General Quality of Life score, in the SNOT-20 GAV as well as of the TS in the DRQ. Before treatment, divers who required surgery reported significantly more symptoms than divers who were treated conservatively. Post treatment there were no significant differences between the medical and surgical group. Overall, 35 divers could resume diving after therapy even though PSB still occurred but without complications. Divers with sinus problems can successfully be managed medically and if conservative treatment fails, FESS shows a statistically significant improvement of symptoms and no serious long-term hazards for diving.
Archives of Oto-Rhino-Laryngology 09/2011; 269(3):853-60. · 1.29 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Surgery after (chemo)radiation (RCTX/RTX) is felt to be plagued with a high incidence of wound healing complications reported to be as high as 70%. The additional use of vascularized flaps may help to decrease this high rate of complications. Therefore, we examined within a retrospective single-institutional study the peri--and postoperative complications in patients who underwent surgery for salvage, palliation or functional rehabilitation after (chemo)radiation with regional and free flaps. As a second study end point the Karnofsky performance status (KPS) was determined preoperatively and 3 months postoperatively to assess the impact of such extensive procedures on the overall performance status of this heavily pretreated patient population.
21 patients were treated between 2005 and 2010 in a single institution (17 male, 4 female) for salvage (10/21), palliation (4/21), or functional rehabilitation (7/21). Overall 23 flaps were performed of which 8 were free flaps. Major recipient site complications were observed in only 4 pts. (19%) (1 postoperative haemorrhage, 1 partial flap loss, 2 fistulas) and major donor site complications in 1 pt (wound dehiscence). Also 2 minor donor site complications were observed. The overall complication rate was 33%. There was no free flap loss. Assessment of pre- and postoperative KPS revealed improvement in 13 out of 21 patients (62%). A decline of KPS was noted in only one patient.
We conclude that within this (chemo)radiated patient population surgical interventions for salvage, palliation or improve function can be safely performed once vascularised grafts are used.
Radiation Oncology 09/2011; 6:109. · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Curcuma longa L. has long been used as a medicinal plant in traditional Chinese medicine against abdominal disorders. Its active constituent curcumin has anti-inflammatory, chemopreventive and cytotoxic properties. In the present investigation, we have analyzed the cytotoxic activity of curcumin and four derivatives. Among these compounds, ethoxycurcumintrithiadiazolaminomethylcarbonate was the most cytotoxic one. The curcumin-type compounds were not cross-resistant to standard anticancer drugs and were not involved in ATP-binding cassette transporter-mediated multidrug resistance. A combined approach of messenger RNA-based microarray profiling, COMPARE analyses and signaling pathway analyses identified genes as determinants of sensitivity and resistance to curcumin and specific signaling routes involved in cellular response to curcumin. These genes may be useful as biomarkers to develop individualized treatment options in the future. From a nutritional point of view, it is a thriving perspective to further investigate whether C. longa may be used as a spice to improve cancer therapy.
The Journal of nutritional biochemistry 08/2011; 23(8):875-84. · 4.29 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Chronic suppurative otitis media (CSOM) is frequently associated with symptoms of inflammation like discharge from the ear or pain. In many cases, patients suffer from hearing loss causing communication problems and social withdrawal. The objective of this work was to collect prospective audiological data and data on general and disease-specific quality of life with validated quality of life measurement instruments to assess the impact of the disease on health-related quality of life (HR-QOL).
121 patients were included in the study. Patients were clinically examined in the hospital before and 6 months after surgery including audiological testing. They filled in the quality of life questionnaires SF-36 and Chronic Otitis Media Outcome Test 15 (COMOT-15) pre-operatively and 6 and 12 months post-operatively, respectively.
Complete data records from 90 patients were available for statistical analysis. Disease-specific HR-QOL in patients with CSOM improved after tympanoplasty in all the scales of the COMOT-15. There was no difference in HR-QOL assessment between patients with mesotympanic respectively epitympanic CSOM. However, we did find the outcome to be worse in patients who received revision surgery compared with those receiving primary surgery. Audiometric findings correlated very well with the subscale hearing function from the COMOT-15 questionnaire. General HR-QOL measured with the SF-36 was not significantly changed by tympanoplasty.
Tympanoplasty did lead to a significant improvement of disease-specific HR-QOL in patients with CSOM while general HR-QOL did not change. Very well correlations were found between the subscale hearing function from the COMOT-15 questionnaire and audiological findings. Revision surgery seems to be a predictor for a worse outcome.
Health and Quality of Life Outcomes 06/2011; 9:48. · 2.11 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Vinblastine and vincristine are dimeric indole alkaloids derived from Catharanthus roseus (formerly: Vinca rosea). Their monomeric precursor molecules are vindoline and catharanthine. While vinblastine and vincristine are well-known mitotic spindle poisons, not much is known about vindoline and catharanthine. Vindoline and catharanthine showed weak cytotoxicity, while vinblastine, vincristine, and the semisynthetic vindesine and vinorelbine revealed high cytotoxicity towards cancer cells. This may reflect a general biological principle of poisonous plants. Highly toxic compounds are not only active towards predators, but also towards plant tissues. Hence, plants need mechanisms to protect themselves from their own poisons. One evolutionary strategy to solve this problem is to generate less toxic precursors, which are dimerized to toxic end products when needed. As shown by in silico molecular docking and biochemical approaches, vinblastine, vincristine and vinorelbine bound with high affinity to α/β-tubulin and inhibited tubulin polymerization, whereas the effects of vindoline and catharanthine were weak. Similarly, vinblastine produced high fractions of mono- and multipolar mitotic spindles, while vindoline and catharanthine did only weakly affect bipolar mitotic spindle formation. Here, we show that vinblastine contributes to cell death by interference with spindle polarity. P-glycoprotein-overexpressing multidrug-resistant CEM/VCR1000 cells were highly resistant towards vincristine and cross-resistant to vinblastine, vindesine, and vinorelbine, but not or only weakly cross-resistant to vindoline and catharanthine. In addition to tubulin as primary target, microarray-based mRNA signatures of responsiveness of these compounds have been identified by COMPARE and signaling pathway profiling.
Biochemical pharmacology 03/2011; 81(6):723-35. · 4.25 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Oral cavity squamous cell carcinoma (OCSCC) accounts for 2% to 3% of all malignancies and has a high mortality rate. The majority of anticancer drugs are of natural origin. However, it is unknown whether the medicinal plant Thymus vulgaris L. (thyme) is cytotoxic towards head and neck squamous cell carcinoma (HNSCC).
Cytotoxicity of thyme essential oil was investigated on the HNSCC cell line, UMSCC1. The IC₅₀ of thyme essential oil extract was 369 μg/ml. Moreover, we performed pharmacogenomics analyses.
Genes involved in the cell cycle, cell death and cancer were involved in the cytotoxic activity of thyme essential oil at the transcriptional level. The three most significantly regulated pathways by thyme essential oil were interferon signaling, N-glycan biosynthesis and extracellular signal-regulated kinase 5 (ERK5) signaling.
Thyme essential oil inhibits human HNSCC cell growth. Based on pharmacogenomic approaches, novel insights into the molecular mode of anticancer activity of thyme are presented.
Anticancer research 01/2011; 31(1):81-7. · 1.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Oral squamous cell carcinoma (OSCC) is a challenging disease with a high mortality rate. Natural products represent a valuable source for the development of novel anticancer drugs. We investigated the cytotoxic potential of essential oil from the leaves of a medicinal plant, Levisticum officinale (lovage) on head and neck squamous carcinoma cells (HNSCC).
Cytotoxicity of lovage essential oil was investigated on the HNSCC cell line, UMSCC1. Additionally, we performed pharmacogenomics analyses.
Lovage essential oil extract had an IC₅₀ value of 292.6 μg/ml. Genes involved in apoptosis, cancer, cellular growth and cell cycle regulation were the most prominently affected in microarray analyses. The three pathways to be most significantly regulated were extracellular signal-regulated kinase 5 (ERK5) signaling, integrin-linked kinase (ILK) signaling, virus entry via endocytic pathways and p53 signaling.
Levisticum officinale essential oil inhibits human HNSCC cell growth.
Anticancer research 01/2011; 31(1):185-91. · 1.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We reasoned that micro-dissection of tumour cells for protein expression studies should be omitted since tumour-stroma interactions are an important part of the biology of solid tumours. To study such interactions in head and neck squamous cell carcinoma (HNSCC) development, we generated reference protein spectra for normal squamous epithelium and connective tissue by SELDI-TOF-MS. Calgranulins A and B, Annexin1 and Histone H4 were found to be strongly enriched in the epithelium. The alpha-defensins 1-3 and the haemoglobin subunits were identified in the connective tissue. Tumour-distant epithelia, representing early pre-malignant lesions, showed up-regulated expression of the stromal alpha-defensins, whereas the epithelial Annexin 1 was down-regulated. Thus, tumour microenvironment interactions occur very early in the carcinogenic process. These data demonstrate that omitting micro-dissection is actually beneficial for studying changes in protein expression during development and progression of solid tumours.
Archives of Physiology and Biochemistry 11/2010; 116(4-5):218-26.
-
[show abstract]
[hide abstract]
ABSTRACT: The new length-adjustable titanium prosthesis can give good results in terms of hearing results in ossiculoplasty. The possibility to readjust the length intraoperatively was seen as a good feature.
Hearing results of ossiculoplasty with a newly designed prosthesis in 14 patients were evaluated. The prosthesis is designed to allow adjustment of length in situ.
A retrospective pilot study was carried out, comparing the preoperative and postoperative audiological and clinical results with an age- and pathology-matched group. The setting was the Department of Otolaryngology at the University of Heidelberg Medical Center, a tertiary referral center. In all, 14 patients underwent tympano-ossiculoplasty in which autologous reconstruction was not an option. The ossiculoplasty was performed as a therapeutic measure with the new titanium prosthesis. We evaluated the air–bone gap closure as established from preoperative and postoperative audiograms. We also looked at the clinical aspect of the tympanic membrane.
The average air–bone gap came to a closure within 15 dB in 43% of the cases (6 of 14 patients). No re-perforations or extrusions of the prostheses were observed.
Acta oto-laryngologica 11/2010; 130(11):1237-41. · 0.98 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The epidermal growth factor receptor (EGFR) has become an important molecular target in cancer therapy. Various small molecules and therapeutic antibodies targeting EGFR family members have been developed during recent years and are established in clinical oncology. However, increasing clinical application of EGFR tyrosine kinase inhibitors has resulted in the development of resistance to EGFR-targeting drugs due to the selection of EGFR-mutated variants. This phenomenon forced the search for novel EGFR inhibitors with activity towards EGFR-mutant tumors. This review describes recent achievements in natural products derived from medicinal plants as novel EGFR inhibitors.
Combinatorial chemistry & high throughput screening 09/2010; 13(10):849-54. · 2.46 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A-mode ultrasound scanning with coded signals allows bone thickness measurements at the site of bone-anchored hearing aid surgery as compared to computed tomographic scanning and mechanical measurements.
Adequate bone thickness is a prerequisite for successful, long-lasting osseointegration of titanium fixtures for bone-anchored hearing aids. Computed tomography can be used to measure bone thickness but has several drawbacks.
Bone thickness was measured at the site of bone-anchored hearing aids surgery in 28 formaldehyde-preserved human cadaver temporoparietal bones. Four blinded investigators used a hand-held, A-mode ultrasound system with direct coupling at 2.25 MHz transducer using coded signals (SonoPointer) and repeated the measurements twice. Comparisons were made with high-resolution computed tomographic scanning and mechanical micrometer caliper measurements.
There was significant anatomical variation in the temporoparietal bones. Computed tomography was in good agreement with the mechanical reference. All specimens could be measured by the SonoPointer. The mean difference between the mechanical control and ultrasound scanning averaged for all measurements by all investigators was 0.3 mm (standard deviation, 1.2 mm). Trained ultrasound experts yielded better results (mean difference, 0.3 mm; standard deviation, 1.0 mm). Agreement was best for bone thickness up to 5 mm. Outliers occurred in bones thicker than 7.5 mm.
The SonoPointer is a promising, noninvasive, hand-held tool for real-time measurement of bone thickness in bone-anchored hearing aid surgery, especially for children. Even disregarding the absolute thickness reading, the SonoPointer could be used to search intraoperatively for a local maximum of bone thickness.
Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 04/2010; 31(3):440-6. · 1.44 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Development of novel therapy strategies is one of the major pressing topics of clinical oncology to overcome drug resistance of tumors. Artesunate (ART) is an anti-malarial drug, which also exerts profound cytotoxic activity towards cancer cells. We applied a gene-hunting approach using microarray-based transcriptome-wide mRNA expression profiling and COMPARE analyses. We identified a set of genes, whose expression was associated either with high IC50 values or low IC50 values for ART. Therefore, these genes may function as resistance or sensitivity factors for response of tumor cells towards ART. This viewpoint is conceivable for genes involved in ribosomal activity, drug transport, cellular antioxidant defense, apoptosis, cell proliferation, cell cycle progression etc. An investigation of underlying signal transduction by pathway analysis suggested a role of the signaling pathways related to tumor necrosis factor (TNF) and the tumor suppressor p53. On the other hand, there were genes without obvious functional link to cellular response to ART, such as genes involved in the survival of cochlear outer and inner hair cells etc. We proved the hypothesis that ART influences the activity of transcription factors regulating downstream genes involved or not involved in response of cancer cells towards ART. This would explain the identification of genes with and without obvious relation to the cytotoxic activity of ART by microarray and COMPARE analyses. By analysis of the binding motifs for the transcription factors c-Myc and Max, we indeed found that 53 of 56 genes contained one or more binding sites for c-Myc/Max upstream of the gene-location. We conclude that c-Myc and Max-mediated transcriptional control of gene expression might contribute to the therapeutic effects of ART in cancer cells, but may also confer unwanted side effects by affecting therapy-unrelated genes.
Molecules 04/2010; 15(4):2886-910. · 2.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Clinical oncology is still challenged by the development of drug resistance of tumors that result in poor prognosis for patients. There is an urgent necessity to understand the molecular mechanisms of resistance and to develop novel therapy strategies. Artesunate (ART) is an anti-malarial drug, which also exerts profound cytotoxic activity towards cancer cells. We first applied a gene-hunting approach using cluster and COMPARE analyses of microarray-based transcriptome-wide mRNA expression profiles. Among the genes identified by this approach were genes from diverse functional groups such as structural constituents of ribosomes (RPL6, RPL7, RPS12, RPS15A), kinases (CABC1, CCT2, RPL41), transcriptional and translational regulators (SFRS2, TUFM, ZBTB4), signal transducers (FLNA), control of cell growth and proliferation (RPS6), angiogenesis promoting factors (ITGB1), and others (SLC25A19, NCKAP1, BST1, DBH, FZD7, NACA, MTHFD2). Furthermore, we applied a candidate gene approach and tested the role of resistance mechanisms towards established anti-cancer drugs for ART resistance. By using transfected or knockout cell models we found that the tumor suppressor p16(INK4A) and the anti-oxidant protein, catalase, conferred resistance towards ART, while the oncogene HPV-E6 conferred sensitivity towards ART. The tumor suppressor p53 and its downstream protein, p21, as well as the anti-oxidant manganese-dependent superoxide dismutase did not affect cellular response to ART. In conclusion, our pharmacogenomic approach revealed that response of tumor cells towards ART is multi-factorial and is determined by gene expression associated with either ART sensitivity or resistance. At least some of the functional groups of genes (e.g. angiogenesis promoting factors, cell growth and proliferation-associated genes signal transducers and kinases) are also implicated in clinical responsiveness of tumors towards chemotherapy. It merits further investigation, whether ART is responsive in clinically refractory tumors and whether the genes identified in the present study also determine clinical responsiveness towards ART.
Chemico-biological interactions 02/2010; 185(1):42-52. · 2.46 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The lack of effective long-term anticancer therapy highlights the necessity to identify new potent anticancer compounds. Many
biocompounds of naturally occurring medicinal plants have pharmacological activities and, thus, represent a source of molecules
that may have anti-proliferative effects on a variety of cancers. During the past 10 years, we have systematically analyzed
medicinal plants used in traditional Chinese medicine and focused our interest on Artemisia annua (sweet wormwood herb). The active principle of sweet wormwood herb is Artemisinin, a sesquiterpene, which exerts not only
anti-malarial activity but also profound cytotoxicity against tumour cells. The anti-tumour mechanism shares similarities
to the anti-malarial mechanism: the Artemisinin molecule contains an endoperoxide bridge that reacts with an iron atom to
form free radicals causing macromolecular damage and cell death. The anticancer activity of artesunate, a semi-synthetic derivative
of Artemisinin, has also been shown in human xenograft tumours in mice and dogs. First encouraging experience in the clinical
treatment of patients suffering from laryngeal carcinoma, uveal melanoma, pituitary macroadenoma and non-small cell lung cancer
calls for comprehensive clinical trials with artesunate for cancer treatment in the near future. In this chapter, we summarize
novel developments on Artemisinin and its derivatives concerning mode of action, metabolism, toxicity, in vivo effects, clinical
application and biotechnological production methods.
01/2010: pages 227-251;
-
[show abstract]
[hide abstract]
ABSTRACT: The effects on quality of life (QoL) in adult patients with chronic tonsillitis are multidimensional. Tonsillectomy has been and is still the standard for treating these patients, who fulfil certain clinical criteria, and is thus the main determinant in the change of QoL. The reduction in severity and frequency of symptoms, health care utilization, physician visits and days off work are major factors in the improvement of QoL. Other important aspects are the management of the postoperative pain and the avoidance of post tonsillectomy hemorrhage. Economic benefits of tonsillectomy receive increasing attention as there can be direct associations with the patients' QoL. Studies concerning the clinical efficacy of tonsillectomy, various techniques in order to achieve the best outcome, postoperative pain relieving measures, methods to minimize postoperative hemorrhage rates, and studies of cost-effectiveness of this intervention will be reviewed and discussed.
The Open Otorhinolaryngology Journal 01/2010; 4:34-46.
-
[show abstract]
[hide abstract]
ABSTRACT: Das Hören spielt für uns Menschen eine ganz überragende Rolle. Und dies in jedem Lebensalter. Leider nimmt jedoch das Ausmaß
einer Hörminderung im Laufe des Lebens eher zu. Dieses führt zu einem zunehmenden Verlust an Kommunikation. Bedingt durch
diesen Hörverlust kommt es dann oft zur Erschwerung der Verständigung bis hin zur Vereinsamung. Dies gerade, wenn die Betroffenen
merken, dass sie nicht mehr an Gesprächen teilnehmen können, nachfragen müssen, und damit sich und anderen (zu unrecht!) „dumm“
vorkommen. Die Bewältigung alltäglicher Lebensaufgaben wird so erheblich schwieriger. Und wenn schließlich ein nahezu vollständiger
Hörverlust vorliegt, ist das Risiko des Autonomieverlustes groß. Aber auch ohne ihn ist der Verlust an Lebensqualität erheblich
und belastend.
12/2009: pages 81-93;
-
[show abstract]
[hide abstract]
ABSTRACT: Head and neck squamous cell carcinoma has still a poor prognosis. Since angiogenesis is crucial for tumor growth, a better understanding of the potential clinical relevance as well as the interactions between the numerous proangiogenic growth factors is essential to develop improved therapeutic strategies in these tumors. Expression levels of eight growth factors known to induce angiogenesis (HGF, bFGF, VEGF-A, VEGF-D, PDGF-AB, PDGF-BB, G-CSF, and GM-CSF) were quantitatively measured by ELISA in homogenates of 41 head and neck squamous cell carcinomas. In addition, microvessel density and protein localization of growth factors were assessed by immunohistochemistry. Statistical analysis was performed to assess interrelationships between growth factors analyzed and to correlate protein levels with patient outcome. In 90% of the tissues at least 4/8 growth factors analyzed were detectable. Highest amounts and most frequent expression were found for HGF, bFGF and VEGF-A while PDGF-AB and PDGF-BB were present in two-thirds and G-CSF and GM-CSF in approximately half of the cases. Although there was no significant relation to microvessel density, we identified significant associations for bFGF with HGF and G-CSF as well as of PDGF-AB with those of VEGF-A and PDGF-BB. For the first time we demonstrate that expression levels of HGF as well as that of bFGF and G-CSF in head and neck squamous tumors are negative prognostic factors for patient survival. Our data indicate a network of interrelated and prognostically relevant growth factors in these tumors that have to be taken into consideration when planning an antiangiogenic and antitumor therapy.
Cancer Science 04/2009; 100(7):1210-8. · 3.33 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the protective effects of bcl-2, we have developed an in vivo model of gentamicin ototoxicity in C57BL/6 mice using intratympanic delivery of gentamicin. Hair cell survival was evaluated using myosin VIIa immunohistochemistry, cytocochleogram and auditory brainstem response (ABR) testing. At 10 days after gentamicin application, a consistent loss of outer hair cells was seen. Mice were pretreated with an adenovector expressing human bcl-2 (Ad.11D.bcl-2) or a control vector (Ad.11D). Seventy-two hours after vector delivery mice were treated with intratympanic gentamicin and evaluated at 10 days after ototoxin delivery. Pretreatment with Ad.11D.bcl-2 resulted in morphologic protection of hair cells and preservation of hearing thresholds measured by ABR.
Audiology and Neurotology 02/2009; 14(4):254-66. · 2.46 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An important requirement for gene therapy in the inner ear is to achieve efficient gene delivery without damaging residual inner ear function. This can be achieved by delivering a high concentration of vector in a minimal volume. Adenovectors are well suited to meet these requirements since high quality concentrated vector with a high capacity for a gene payload can be produced. To reduce the number of vector particles and volume of delivery to the inner ear, we tested vectors with enhancements in cell binding and cell entry properties. We compared delivery of a marker gene to the inner ear using two different advanced generation serotype 5 adenovector designs. The first adenovector tested, AdRGD, has a restricted tropism of entry into cells. AdRGD is an Ad5 capsid vector with an arg-gly-asp (RGD) motif built into the adenovector fiber that has also been modified to abolish the fiber-CAR and penton-integrin interactions that provide the normal well characterized two-step entry pathway for adenovirus. The AdRGD vector has enhanced binding to alphanu integrins. The second vector, AdF2K, contains 7 lysine residues within the fiber knob and has been shown to have expanded tropism for cells in vitro and in vivo. AdF2K maintains its normal CAR and integrin receptors interactions and has an additional mechanism of entry via its ability to interact with heparan sulfate. Both vectors demonstrated effective delivery to the inner ear and more uniform labeling of the inner ear sensory epithelia than native capsid vector, when tested in vivo. Analysis of expression efficiency using quantitative PCR was tested in vitro on cultured macular organs and demonstrated that vector delivery with the AdF2K vector design yielded optimal delivery. The present study demonstrates that retargeting strategies can improve delivery to the inner ear.
Hearing research 01/2009; 248(1-2):31-8. · 2.18 Impact Factor
