Oncolytic viruses that are replication competent in tumor but not in normal cells represent a novel approach for treating neoplastic diseases. However, the oncolytic potency of replicating agents is determined directly by their capability of infecting target cells. Most adenoviruses used for gene therapy or virotherapy have been based on serotype 5 (Ad5). Unfortunately, expression of the primary receptor for Ad5 (the coxsackie-adenovirus receptor, or CAR) is highly variable on ovarian and other cancer cells. By performing genetic fiber pseudotyping, we created Ad5/3-Delta24, a conditionally replicating adenovirus that does not bind CAR but facilitates entry into and killing of ovarian cancer cells. We show replication of Ad5/3-Delta24 and subsequent oncolysis of ovarian adenocarcinoma lines. Replication was also analyzed with quantitative PCR on three-dimensional primary tumor cell spheroids purified from patient samples. Moreover, in a therapeutic orthotopic model of peritoneal carcinomatosis, dramatically enhanced survival was noted. Finally, Ad5/3-Delta24 achieved a significant antitumor effect as assessed by noninvasive, in vivo bioluminescence imaging. Therefore, the preclinical therapeutic efficacy of Ad5/3-Delta24 is improved over the respective CAR- and integrin-binding controls. Taken together with promising biodistribution and toxicity data, this approach could translate into successful clinical interventions for ovarian cancer patients.

There has been a rapid growth of bioluminescence imaging applications in small animal models in recent years, propelled by the availability of instruments, analysis software, reagents, and creative approaches to apply the technology in molecular imaging. Advantages include the sensitivity of the technique as well as its efficiency, relatively low cost, and versatility. Bioluminescence imaging is accomplished by sensitive detection of light emitted following chemical reaction of the luciferase enzyme with its substrate. Most imaging systems provide 2-dimensional (2D) information in rodents, showing the locations and intensity of light emitted from the animal in pseudo-color scaling. A 3-dimensional (3D) capability for bioluminescence imaging is now available, but is more expensive and less efficient; other disadvantages include the requirement for genetically encoded luciferase, the injection of the substrate to enable light emission, and the dependence of light signal on tissue depth. All of these problems make it unlikely that the method will be extended to human studies. However, in small animal models, bioluminescence imaging is now routinely applied to serially detect the location and burden of xenografted tumors, or identify and measure the number of immune or stem cells after an adoptive transfer. Bioluminescence imaging also makes it possible to track the relative amounts and locations of bacteria, viruses, and other pathogens over time. Specialized applications of bioluminescence also follow tissue-specific luciferase expression in transgenic mice, and monitor biological processes such as signaling or protein interactions in real time. In summary, bioluminescence imaging has become an important component of biomedical research that will continue in the future.

The adenovirus (Ad) is a useful vector for cancer gene therapy due to its unparalleled gene transfer efficiency to dividing and quiescent cells. Primary cancer cells, however, often have highly variable or low levels of the requisite coxsackie-adenovirus receptor (CAR). Also, assessment of gene transfer and vector persistence has been logistically difficult in human clinical trials. We describe here two novel bicistronic adenoviral (Ad) vectors, AdTKSSTR and RGDTKSSTR, which contain the herpes simplex virus thymidine kinase gene (TK) for molecular chemotherapy and bystander effect. In addition, the viruses contain the human somatostatin receptor subtype-2 gene (SSTR2), the expression of which can be noninvasively imaged. We enhanced the infectivity of RGDTKSSTR by genetically incorporating the RGD-4C motif into the HI-loop of the fiber. This allows the virus to circumvent CAR deficiency by binding to alpha(v)beta(3) and alpha(v)beta(5) integrins, which are highly expressed on most ovarian cancers. The expanded tropism of RGDTKSSTR results in increased infectivity of purified primary ovarian cancer cells and allows enhanced gene transfer in the presence of malignant ascites containing anti-Ad antibodies. RGDTKSSTR may be a useful agent for treating ovarian cancer in clinical trials.

Pemetrexed was well tolerated at doses of 500 mg/m2 with vitamin supplementation in patients with GFR > or = 40 mL/min. Additional studies are needed to define appropriate dosing for renally impaired patients receiving higher dose pemetrexed with vitamin supplementation.

Development of anti-Fas Abs to treat diseases with insufficient Fas-mediated apoptosis has been limited by concern about hepatotoxicity. We report here that hepatotoxicity elicited by anti-Fas Ab Jo2 is dependent on FcγRIIB. Thus, following Jo2 treatment, all FcγRIIB−/− mice survived while 80% of wild-type and all FcR-γ−/− mice died from acute liver failure. Microscopic examination suggests that FcγRIIB deficiency protects the hepatic sinusoidal endothelium, a cell type that normally coexpresses Fas and FcγRIIB. In vitro studies showed that FcγRIIB, but not FcγRI and FcγRIII, on neighboring macrophages substantially enhanced Jo2 mediated apoptosis of Fas expressing target cells. However, FcγRI and FcγRIII appeared essential for apoptosis-inducing activity of a non-hepatotoxic anti-Fas mAb HFE7A. These findings imply that by interacting with the Fc region of agonistic Abs, FcγRs can modulate both the desired and undesired consequences of Ab-based therapy. Recognizing this fact should facilitate development of safer and more efficacious agonistic Abs.

To evaluate the potential occurrence of right ventricular infarction, 53 patients with acute inferior transmural myocardial infarction were studied within 36 hours of symptoms by right heart catheterization, equilibrium radionuclide angiography and two-dimensional echocardiography. Technetium-99m pyrophosphate myocardial scintigraphy was performed 3 days after the onset of symptoms. The hemodynamic standard for right ventricular infarction was defined as both a right atrial pressure of 10 mm Hg or more and a right atrial/pulmonary artery wedge pressure ratio of 0.8 or more. Eight (15%) of the 53 patients had hemodynamic measurements at rest characteristic of right ventricular infarction, and 6 (11%) additional patients met these criteria after volume loading (p less than 0.05). Nineteen (37%) of the 51 patients who had radionuclide angiography had right ventricular dysfunction manifested by both a reduced right ventricular ejection fraction (less than 40%) and right ventricular regional wall motion abnormalities (akinesia or dyskinesia). An abnormal radionuclide angiogram was observed in 12 of 13 patients with hemodynamic measurements indicating right ventricular infarction. In 12 patients with an abnormal radionuclide angiographic study, right ventricular ejection fraction improved 6 to 12 weeks after infarction (27 +/- 7 to 36 +/- 9%, p less than 0.01). Twenty-two (49%) of the 45 patients with adequate two-dimensional echocardiograms had a right ventricular regional wall motion abnormality. An abnormal two-dimensional echocardiogram was seen in 9 of 11 patients with hemodynamic measurements characteristic of right ventricular infarction. Technetium-99m pyrophosphate scintigraphy was positive for right ventricular infarction in 3 of 12 patients who had hemodynamic measurements indicating right ventricular infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Physicians and surgeons rely on subtle tissue changes to detect the extent of tumors and the presence of residual disease in the clinical setting. The development of a cancer-specific fluorescent contrast agent has the potential to provide real-time tumor imaging in the clinic or operating room. Because epidermal growth factor receptor (EGFR) is highly overexpressed on the surface of head and neck squamous cell carcinoma (HNSCC), we sought to determine if fluorescently labeled anti-EGFR antibody could be used to image HNSCC xenografts in vivo. Cetuximab or control isotype-matched IgG1 was conjugated with the Cy5.5 fluorochrome and systemically injected into mice bearing human split thickness skin grafts, tumor cell line xenografts, transplanted human tumor xenografts, or mouse mesothelioma tumors. Xenografts were imaged by time-domain fluorescence imaging or fluorescence stereomicroscopy. Both imaging modalities detected specific uptake of cetuximab-Cy5.5 in HNSCC xenografts with significantly higher fluorescence levels relative to control IgG1-Cy5.5. Tumor xenograft fluorescence was higher compared with background (before injection), human split thickness skin grafts, or mouse mesothelioma tumors at 24, 48, and 72 h. Fluorescence was detected in multiple HNSCC tumor cell lines with variable EGFR expression levels. Mock resections of flank tumors using fluorescence stereomicroscopy showed that small (2 mm) specimens could be detected in the surgical wound bed. These results show the feasibility of using fluorescently labeled anti-EGFR antibody to detect human tumors in the surgical setting. [Mol Cancer Ther 2007;6(4):1230 -8]

Factors that promote oropharyngeal colonization of seriously ill patients with gram-negative bacilli are as yet poorly understood. In this investigation, 34 subjects who required intensive care were studied; 18 (53%) were colonized with gram-negative bacilli. Oropharyngeal epithelial cells of all colonized patients contained adherent bacilli. Fewer alpha-hemolytic streptococci but greater numbers of Pseudomonas aeruginosa and Klebsiella pneumoniae (P less than or equal to 0.01) adhered in vitro to buccal epithelial cells from colonized patients than to cells from noncolonized patients. Adherence of bacilli to buccal cells was inhibited in vitro by concanavalin A but not by bovine serum albumin or phytohemagglutinin. Brief exposure of buccal cells to trypsin increased adherence of bacilli. Prior adherence of one species of bacilli inhibited subsequent adherence of a second species. These findings suggested that epithelial cells of the upper respiratory tract contain binding sites for gram-negative bacilli. Factors associated with serious illness appear to increase the availability of these binding sites, thus facilitating colonization of the upper respiratory tract with gram-negative bacilli.