Antibody therapies for the treatment of acute myeloid leukemia: exploring current and emerging therapeutic targets.

INTRODUCTION: Acute myeloid leukemia (AML) is the most common and deadly type of leukemia affecting adults. It is typically managed with rounds of non-targeted chemotherapy followed by hematopoietic stem cell transplants, but this is only possible in patients who can tolerate these harsh treatments and many are elderly and frail. With the identification of novel tumor-specific cell surface receptors, there is great conviction that targeted antibody therapies will soon become available for these patients. AREAS COVERED: In this review, we describe the current landscape of known target receptors for monospecific and bispecific antibody-based therapeutics for AML. Here, we characterize each of the receptors and targeted antibody-based therapeutics in development, illustrating the rational design behind each therapeutic compound. We then discuss the bispecific antibodies in development and how they improve immune surveillance of AML. For each therapeutic, we also summarize the available pre-clinical and clinical data, including data from discontinued trials. EXPERT OPINION: One antibody-based therapeutic has already been approved for AML treatment, the CD33-targeting antibody-drug conjugate, gemtuzumab ozogamicin. Many more are currently in pre-clinical and clinical studies. These antibody-based therapeutics can perform tumor-specific, elaborate cytotoxic functions and there is growing confidence they will soon lead to personalized, safe AML treatment options that induce durable remissions.

The Long Noncoding RNA RP11-728F11.4 Promotes Atherosclerosis.

OBJECTIVE: Noncoding RNAs are emerging as important players in gene regulation and cardiovascular diseases. Their roles in the pathogenesis of atherosclerosis are not fully understood. The purpose of this study was to determine the role played by a previously uncharacterized long noncoding RNA, RP11-728F11.4, in the development of atherosclerosis and the mechanisms by which it acts. Approach and Results: Expression microarray analysis revealed that atherosclerotic plaques had increased expression of RP11-728F11.4 as well as the cognate gene FXYD6 (FXYD domain containing ion transport regulator 6), which encodes a modulator of Na+/K+-ATPase. In vitro experiments showed that RP11-728F11.4 interacted with the RNA-binding protein EWSR1 (Ewings sarcoma RNA binding protein-1) and upregulated FXYD6 expression. Lentivirus-induced overexpression of RP11-728F11.4 in cultured monocytes-derived macrophages resulted in higher Na+/K+-ATPase activity, intracellular cholesterol accumulation, and increased proinflammatory cytokine production. The effects of RP11-728F11.4 were enhanced by siRNA-mediated knockdown of EWSR1 and reduced by downregulation of FXYD domain containing ion transport regulator 6. In vivo experiments in apoE knockout mice fed a Western diet demonstrated that RP11-728F11.4 increased proinflammatory cytokine production and augmented atherosclerotic lesions. CONCLUSIONS: RP11-728F11.4 promotes atherosclerosis, with an influence on cholesterol homeostasis and proinflammatory molecule production, thus representing a potential therapeutic target. Graphic Abstract: A graphic abstract is available for this article.

Spatial and Temporal Confined Photothermolysis of Cancer Cells Mediated by Hollow Gold Nanospheres Targeted to Epidermal Growth Factor Receptors.

To date, a few studies have investigated the potential use of a short-pulsed laser in selective tumor cell destruction or its mechanism of cell killing. Computer simulation of the spatial and temporal profiles of temperature elevation after pulsed laser irradiation on an infinitesimal point source estimated that the temperature reached its highest point at ∼35 ns after a single 15 ns laser pulse. Moreover, temperature elevation was confined to a radius of sub-micrometer and returned to baseline within 100 ns. To investigate the effect of 15 ns laser pulses on A431 tumor cells, we conjugated hollow gold nanospheres (HAuNSs) to an antibody (C225) directed at the epithelial growth factor receptor. The resulting nanoparticles, C225-HAuNSs, bound to the cell membrane, internalized, and distributed throughout the cytoplasm, with some nanoparticles transported to the vicinity of the nuclear membrane. On using an optical microscope mounted to a tunable pulsed Ti:sapphire laser, rapid and extensive damage of live cancer cells was observed, whereas irradiation of A431 cells pretreated with nontargeted HAuNSs with a pulsed laser or pretreated with C225-HAuNSs with a continuous-wave laser-induced minimal cellular damage. Furthermore, after a single 15 ns laser pulse, C225-HAuNS-treated A431 cells cocultured with 3T3 fibroblasts showed signs of selective destruction. Thus, compared with a continuous-wave laser, shots of a short-pulsed laser were the most damaging to tumor cells that bound HAuNSs and generated the least heat to the surrounding environment. This mode of action by a short-pulsed laser on cancer cells (i.e., confined photothermolysis) may have potential applications in selective tumor cell destruction.

Determination of oral bioavailability of fusaric acid in male Sprague-Dawley rats.

Head and neck squamous cell cancer accounts for 3 % of new cancer cases and 2 % of cancer mortality annually in the United States. Current treatment options for most head and neck cancers continue to be surgical excision with or without radiation, radiation alone, or chemotherapy with radiation depending on location, stage of disease, and patient preference. Fusaric acid (FA) is a novel compound from a novel class of nicotinic acid derivatives that have activity against head and neck squamous cell carcinoma (HNSCC). Although its exact mechanism is still unknown, FA is thought to be active by increasing damage to DNA and preventing its synthesis and repair. The novel mechanism of FA provides an alternative to present therapies, as a single agent whether given parenterally or orally. It has synergy with conventional agents taxol, carboplatin, and erlotinib. In order to determine if FA has reasonable oral bioavailability, we have determined the pharmacokinetics of FA in male Sprague Dawley rats following administration by gavage and by intravenous injection. The bioavailability of FA was sufficient (58 %) to suggest that FA may be viable as an orally administered medication. Despite the encouraging bioavailability of FA, the intravenous (IV) pharmacokinetics suggested non-linear behavior within the IV dose range of 10, 25, and 75 mg/kg. These results demonstrate that further pharmacokinetic and toxicity studies in larger animals such as dogs and non-human primates are warranted.

Orthotopic VX rabbit tongue cancer model with FDG-PET and histologic characterization.

BACKGROUND: We present our experience with the use of an immunocompetent medium-sized animal model of tongue cancer that may be suitable for imaging and surgical studies. METHODS: A New Zealand white rabbit model of tongue cancer was created by injecting a VX tumor cell suspension grown in culture into the tongue of our model. The tumor was examined 7 days following implantation by physical examination, photography, and (18) fluoro 2-deoxyglucose-positron emission tomography (FDG-PET). At 12 days postimplantation, the model was again studied as described above prior to euthanization, and then tongue excision and bilateral neck dissections were performed. All tissue was examined by histology. RESULTS: We confirmed a successful orthotopic tongue cancer model that resulted in cervical nodal metastases. CONCLUSION: This model may be a useful model of orthotopic head and neck cancer for future surgical or imaging research.

How potent is potent? Evaluation of sexual function and bother in men who report potency after treatment for prostate cancer: data from CaPSURE.

OBJECTIVES: To characterize the association between potency and comprehensive sexual function. The accurate assessment of sexual function is critical for the evaluation of outcomes after treatment of prostate cancer. The assessments of potency typically used in this context, however, may be oversimplified. METHODS: CaPSURE is a large, observational database of men with prostate cancer. Participants complete health-related quality-of-life questionnaires, including the University of California, Los Angeles Prostate Cancer Index, every 6 months after treatment. A total of 5135 men completed at least one questionnaire and did not use medications for erectile function. The men were categorized as potent or impotent based on their ability to have erections and/or intercourse in the prior 4 weeks. Using the remaining questions on the Prostate Cancer Index, sexual function and bother scores were calculated for each group. RESULTS: Of the 5135 men, 27.4% were potent. The mean sexual function scores were 56 and 13 for potent and impotent men, respectively (P <0.0001). The corresponding mean bother scores were 62 and 36 (P <0.0001). The function scores ranged from 0 to 100 and 0 to 92 among potent and impotent men, respectively, and bother scores from 0 to 100 in both groups. Function was inversely associated with age in both groups, but bother did not change among potent men and ameliorated among impotent men. Individual Prostate Cancer Index questions correlated with potency to a variable extent. CONCLUSIONS: Although potent and impotent men have divergent sexual function and bother scores after treatment, the wide range of these scores in both groups denotes a complex picture of sexual function. The simple documentation of potency after treatment provides an insufficient measure of sexual health-related quality of life and should be supplemented with more comprehensive measures.

Effective synthetic peptide vaccine for foot-and-mouth disease in swine.

We have designed a peptide-based vaccine for foot-and-mouth disease (FMD) effective in swine. The peptide immunogen has a G-H loop domain from the VP1 capsid protein of foot-and-mouth disease virus (FMDV) and a novel promiscuous T helper (Th) site for broad immunogenicity in multiple species. The G-H loop VP1 site was optimised for cross-reactivity to FMDV by the inclusion into the peptide of cyclic constraint and adjoining sequences. The incorporation of consensus residues into the hypervariable positions of the VP1 site provided for broad immunogenicity. The vaccine protected 20 out of 21 immunised pigs from infectious challenge by FMDV O1 Taiwan using peptide doses as low as 12.5 microg, and a mild adjuvant that caused no lesions. A safe chemically-defined product would have considerable advantages for vaccination against FMD.