The selective delivery of bioactive agents to tumors reduces toxicity and enhances the efficacy of anticancer therapies. In this study, we show that the antibody F8, which recognizes perivascular and ...stromal EDA-fibronectin (EDA-Fn), when conjugated to interleukin-2 (F8-IL2) can effectively inhibit the growth of EDA-Fn-expressing melanomas in combination with paclitaxel. We obtained curative effects with paclitaxel administered before the immunocytokine. Coadministration of paclitaxel increased the uptake of F8 in xenografted melanomas, enhancing tumor perfusion and permeability. Paclitaxel also boosted the recruitment of F8-IL2-induced natural killer (NK) cells to the tumor, suggesting a host response as part of the observed therapeutic benefit. In support of this likelihood, NK cell depletion impaired the antitumor effect of paclitaxel plus F8-IL2. Importantly, this combination reduced both the tumor burden and the number of pulmonary metastatic nodules. The combination did not cause cumulative toxicity. Together, our findings offer a preclinical proof that by acting on the tumor stroma paclitaxel potentiates the antitumor activity elicited by a targeted delivery of IL2, thereby supporting the use of immunochemotherapy in the treatment of metastatic melanoma.
The biomaterial bacterial cellulose (BC) represents an innovative approach for overcoming reconstructive problems associated with extended vascular diseases by providing small caliber vascular grafts ...(diameter 1.0-3.7, length 5.0-10.0, and wall-thickness 0.7 mm). In a first microsurgical study, the BC implants were attached in an artificial defect of the carotid artery of rats for 1 year. These long term results show the incorporation of the BC under formation of neointima and ingrowth of active fibroblasts. In a second study, the grafts were used to replace the carotid arteries of pigs. After 3 months, these grafts were removed and analyzed both macro- and microscopically. Seven grafts (87.5%) were patent whereas one graft was found occluded. These data indicate that the innovative BC engineering technique results in the production of stable vascular conduits and confirm a highly attractive approach to in vivo tissue engineered blood vessels as part of programs in cardiovascular surgery.
The antibody-mediated targeted delivery of cytokines to sites of disease is a promising avenue for cancer therapy, but it is largely unexplored for the treatment of chronic inflammatory conditions. ...Using both radioactive and fluorescent techniques, the human monoclonal antibodies L19 and G11 (specific to two markers of angiogenesis that are virtually undetectable in normal adult tissues) were found to selectively localize at arthritic sites in the murine collagen-induced model of rheumatoid arthritis following intravenous (i.v.) administration. The same animal model was used to study the therapeutic action of the L19 antibody fused to the cytokines IL-2, tumour necrosis factor (TNF) and IL-10. Whereas L19-IL-2 and L19-TNF treatment led to increased arthritic scores and paw swellings, the fusion protein L19-IL-10 displayed a therapeutic activity, which was superior to the activity of IL-10 fused to an antibody of irrelevant specificity in the mouse. The anti-inflammatory cytokine IL-10 has been investigated for the treatment of patients with rheumatoid arthritis, but clinical development plans have been discontinued because of a lack of efficacy. Because the antigen recognised by L19 is strongly expressed at sites of arthritis in humans and identical in both mice and humans, it suggests that the fusion protein L19-IL-10 might help overcome some of the clinical limitations of IL-10 and provide a therapeutic benefit to patients with chronic inflammatory disorders, including arthritis.
Purpose Leiomyosarcoma (LMS) rarely occurs in the head and neck region. These tumors present with a wide range of clinical features, so the diagnosis is predicated on conventional microscopic ...findings coupled with immunohistochemical analysis. Patients and Methods Clinical and histologic data of 7 patients with LMS of the head and neck were recorded retrospectively. In addition to routine immunohistochemistry, staining for cell cycle regulator proteins p16 and p21 was performed. Results Five LMSs (4 intraoral, 1 dermal cheek) occurred primarily in the oral and perioral region. Two LMSs (parietal and sinonasal) were diagnosed as metastases originating from the uterus and pelvis. Treatment of the primary LMSs consisted of radical tumor resection with clear margins. Distant metastases from LMSs were irradiated or excised as palliative treatment. Three of 5 patients (60%) with primarily excised LMS developed recurrence after an average of 7 months, with lung metastases occurring after 17 months. In 1 patient, cervical lymph node metastases were detected after 10 months. Of all patients, 5 died after an average survival period of 2.4 years. The mean survival period of the 5 patients with primary LMS of the head and neck was 3.3 years. All tumors were positive for vimentin and α-smooth muscle actin, with 57% of tumors showing positive nuclear expression of p16 and 71% of p21. Lack of p16 nuclear expression was associated with a shorter mean survival time (1.3 vs 4.3 yr for p16 positivity). Conclusion Lung and cervical lymph node metastases often occur in LMS of the head and neck. Presurgical staging, including gynecologic examination, whole-body computed tomography, and sometimes positron-emission or computed tomography, to rule out LMS metastasis is mandatory. Surgical resection of the tumor should be given top priority. Lack of p16 reactivity may have a prognostic value for LMS because it was related to a trend toward poorer survival.
Cardiac allograft vasculopathy (CAV) and fibrosis are important in chronic cardiac allograft rejection. The aim of our study was to analyze the up-regulation of extra domain A (ED-A) containing ...fibronectin (ED-A(+) Fn) in cardiac allografts after heterotopic rat heart transplantation using a human recombinant antibody applicable for targeted drug delivery.
Cardiac allografts were subjected to immunofluorescence double labelling procedures combining a human recombinant small immunoprotein (SIP) format antibody recognizing ED-A(+) Fn (F8) with antibodies recognizing CD31, ASMA or CD45. Protein expression levels of ED-A(+) Fn were measured by quantitative confocal laser scanning microscopy and messenger RNA expression levels by real-time reverse-transcription polymerase chain reaction.
A distinct re-expression of ED-A(+) Fn was detectable with the F8 antibody, especially in vessel structures exhibiting CAV and in fibrotic areas. ED-A(+) Fn protein deposition but not messenger RNA expression levels increased with rising rejection grade (p ≤ 0.001). There were clear co-localizations of ED-A(+) Fn and α-smooth muscle actin in vessels and in fibrotic areas.
We could show first that ED-A(+) Fn is expressed in rat cardiac allografts in association with CAV and cardiac fibrosis. The protein is detectable with the human recombinant antibody F8 usable for targeted drug delivery to the side of disease. Second, protein expression levels increase with rising rejection grade. Thus, ED-A(+) Fn might be usable to monitor and target CAV as well as fibrosis after heart transplantation.
This study was designed to determine the effects of vandetanib, a small-molecule receptor tyrosine kinase inhibitor of vascular endothelial growth factor and epidermal growth factor receptor, on ...paclitaxel (PTX) tumor distribution and antitumor activity in xenograft models of human ovarian carcinoma. Nude mice bearing A2780-1A9 xenografts received daily (5, 10, or 15 days) doses of vandetanib (50 mg/kg per os), combined with PTX (20 mg/kg intravenously). Morphologic and functional modifications associated with the tumor vasculature (CD31 and α-smooth muscle actin staining and Hoechst 33342 perfusion) and PTX concentrations in plasma and tumor tissues were analyzed. Activity was evaluated as inhibition of tumor growth subcutaneously and spreading into the peritoneal cavity. Vandetanib treatment produced no significant change in tumor vessel density, although a reduced number of large vessels, an increased percentage of mature vessels, and diminished tumor perfusion were evident. Pretreatment with vandetanib led to decreased tumor PTX levels within 1 hour of PTX injection, although 24 hours later, tumor PTX levels were comparable with controls. In efficacy studies, the combination of vandetanib plus PTX improved antitumor activity compared with vandetanib or PTX alone, with greater effects being obtained when PTX was administered before vandetanib. The combination of PTX plus vandetanib reduced tumor burden in the peritoneal cavity of mice and significantly increased their survival. Analysis of vascular changes and PTX tumor uptake in vandetanib-treated tumors may help to guide the scheduling of vandetanib plus PTX combinations and may have implications for the design of clinical trials with these drugs.
In patients with non-small cell lung cancer (NSCLC), mutations in the epidermal growth factor receptor gene (EGFR) have been associated with improved response to tyrosine kinase inhibitors. Two ...hotspot mutations located in exon 19 and exon 21 account for about 90% of all EGFR mutations.
We designed a Bi-PASA (bidirectional PCR amplification of specific alleles) assay to detect the most common exon 19 deletion (codons 746-750) and an allele-specific PCR for the L858R mutation in exon 21. To validate the assays for use in clinical diagnostics, 35 lung adenocarcinoma samples were analyzed.
Both assays provided the predicted amplification pattern for normal and mutant genotypes with high specificity and sensitivity. In serial dilution experiments, the mutant alleles were detectable in mixed samples with an at least 6-fold excess of normal DNA. Three exon 19 deletions were identified in the tumor samples.
Both assays are fast and easy to perform in any routine PCR laboratory with no special equipment other than thermocyclers. They provide sensitive and cost effective initial EGFR testing for identifying lung cancer patients who might clinically benefit from tyrosine kinase inhibitors.
Chronic cardiac rejection is intimately associated with cardiac allograft vasculopathy and fibrosis, both causing severe complications that cannot be reversed. Thus, there is an urgent need for early ...diagnosis and for development of therapeutic agents. Chronic rejection is accompanied by the dramatic upregulation of EDA(+) fibronectin (EDA(+) Fn), which is virtually undetectable in the normal healthy adult.
In this study, we evaluated the potential of the monoclonal antibody F8, specific to that molecule, to selectively accumulate in chronically rejected allografts.
A syngeneic immunocompetent heterotopic rat heart transplantation model was used to induce chronic rejection within 70 days. The F8 antibody or an antibody of irrelevant specificity, labeled with the dye DY-682, was administered and near-infrared fluorescence (NIRF) imaging was performed. Targeting performance was assessed by macroscopic organ imaging and fluorescence microscopy. A selective accumulation of the F8 antibody (but not of the negative control antibody) was observed by NIRF imaging in cardiac allografts. The antibody localized to diseased blood vessels as well as to fibrotic regions, where the cognate antigen is abundantly expressed.
This is the first example of antibody-mediated imaging of chronic cardiac rejection. The findings pave the way to immuno-positron emission tomography (immuno-PET) imaging of this clinical condition in patients using the human F8 antibody labeled with a suitable radionuclide (e.g., iodine-124). Furthermore, it would be conceivable to use the F8 antibody as a delivery vehicle to assess experimentally whether a bioactive payload (e.g., drug or cytokine) may be able to reduce disease progression.
Summary Salivary gland carcinomas (SGC) are rare cancers with poor prognosis and limited response to conventional chemotherapy. New strategies based on molecular targeted therapy are needed and the ...EGFR signaling cascade is considered a possible key pathway for therapeutic molecules. We have analyzed 65 SGC of the main histopathological types for the expression of EGFR and and the mutation status of its downstream effector KRAS. EGFR overexpression (+2, +3) has been identified by immunohistochemistry in 75.4%. KRAS mutation analysis was performed by direct genomic sequencing and revealed a KRAS wildtype in 98.5% except of one adenoid cystic carcinoma with a GGT–GAT transition at codon 12 (Gly12Asp). EGFR overexpression and KRAS wildtype are prerequisites for a successful anti-EGFR therapy. The results of this study plead in favor of further therapeutic trials with EGFR-targeting monoclonal antibodies in SGC.
PDF
