Breast Cancer 

DNA in a test tube
Treatment of Her2+ breast cancer, which accounts for about 20% of all breast cancers, has dramatically improved with the development of targeted therapies (trastuzumab, lapatinib, pertuzumab, trastuzumab linked to a cytotoxic tubule inhibitor) given together with chemotherapy drugs.  [DNA in tube] However, despite improvements in treatment options, ~23% of patients will develop recurrent disease within 5 years after initial treatment and less than 7-8% of patients are cured. Moreover, most patients with recurrent disease do not survive. Thus, there is a need for better treatment options for Her2+ breast cancer. An ideal therapy would selectively target cancer cells, but spare most normal cells, to minimize toxicity. The goal of this project is to develop a 2-pronged strategy for Her2+ breast cancer using targeted delivery of small interfering RNAs (siRNAs) to Her2+ breast cancer cells with the dual aims of directly killing tumor cells and enhancing immune defense. We plan to achieve this goal by developing RNA drug conjugates (aptamer-siRNA chimeras or AsiCs) that link a Her2-targeting aptamer to an siRNA. The aptamers will bind to Her2 on Her2+ breast cancer cells leading to cell uptake and processing of an siRNA that causes gene knockdown selectively in the target cell. The successful completion of this project will result in the development of novel Her2-AsiC drugs for the treatment of Her2+ breast cancers that will be ready for evaluation in clinical studies.

Research Team:  Paloma H. Giangrande and Judy Lieberman (Children’s Hospital Boston)

Prostate Cancer 

Prostate Cancer Img (Wikipedia)
Prostate cancer metastasizes to bone in 50-90% of men with advanced disease (or mCRPC) where it is associated with poor prognosis, decreased overall survival, malignant disease progression, therapy resistance, and rapid decline. Bone metastasis also leads to significant morbidity including debilitating fractures, spinal cord compression and severe bone pain. To date, despite years of research, there is no curative treatment for advanced prostate cancer. Patients with mCRPC are offered standard chemotherapy and/or novel anti-androgen treatment options.  [Prostate Cancer Progression] Unfortunately, most patients fail to respond to these treatments and those who do, inevitably develop resistance and relapse with unremitting disease. The drugs are also non-specific (do not selectively kill or inhibit cancer cells) and thus, often result in high toxicity to normal tissues. These issues underscore the critical need for new cancer cell-targeted therapies to reduce off-target effects while addressing the need to simultaneously inhibit multiple molecular targets to confound the development of resistance. An additional and significant barrier to the development of novel therapies to treat bone metastatic prostate cancer has been the scarcity of relevant pre-clinical models. Our objective is to overcome both of these hurdles by developing novel RNA-based smart drugs with improved efficacy and safety profiles compared to conventional treatments for mCRPC and evaluate these drugs in novel but established mouse models of bone metastatic prostate cancer that closely recapitulate the devastating bone metastatic disease seen in patients with advanced disease. During the project period, we will evaluate two drugs: one drug, an RNA aptamer to prostate specific membrane antigen (PSMA), will be evaluated for its ability to prevent de novo metastases; a second drug, composed of the PSMA RNA aptamer and a cancer-specific siRNA, will be evaluated for its additional cytotoxic effect on established prostate cancer bone metastases.

The following three specific aims are proposed:

  •  Elucidate the mechanism of action of A9g, an in vivo-optimized RNA aptamer to prostate specific membrane antigen (PSMA).

  • Determine the minimum effective dose (MED) and maximum tolerated dose (MTD) of A9g in mice.

  • Develop and characterize RNA smart drugs capable of simultaneously inhibiting PSMA activity and delivering therapeutic siRNAs to prostate cancer cells.

The proposed studies will be performed by a team of four highly accomplished female investigators with synergistic and complementary backgrounds and expertise in PSMA biology (Dr. Leslie Caromile – junior investigator), tumor angiogenesis (Dr. Linda Shapiro), mouse models of prostate cancer (Dr. Christina Jamieson) and RNA therapeutics and smart drug technology (Dr. Paloma Giangrande). The combined contribution of our team is expected to be the development, optimization and thorough preclinical testing of two novel RNA smart drugs for the prevention/treatment of bone metastatic prostate cancer. This contribution is significant because it provides critical endpoints that will enable the timely translation of these novel RNA smart drugs for advanced stage prostate cancer, and thus constitutes critical progress towards addressing an unmet need in cancer medicine. Towards this end, we anticipate that one or both of these drugs will be tested in humans within the next five years.

Research Team:  Paloma H. Giangrande, Christina Jamieson (UCSD)Linda Shapiro (UCHC)

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Vascular Disease

Infusion Process
Cardiovascular disease (CVD) represents the primary cause of morbidity and mortality in the Western world and is projected to be the number one global killer by 2020. Current therapeutic approaches fail to prevent activation of the vascular smooth muscle cell (SMC), the primary mechanism responsible for in-stent restenosis, vein graft atherosclerosis, and cardiac allograft arteriopathy. Furthermore, despite reducing the rate of restenosis, non-selective inhibition of cell growth by drug-eluting stents impairs endothelial cell function and predisposes to stent thrombosis and death.  [infusion] Ideal therapeutic interventions for CVD would inhibit SMC migration and proliferation while protecting endothelial cell function. Our long-term goal is to develop cell targeted approaches for the treatment of hyperproliferative diseases such as cancer and CVD. The proposed studies take advantage of recent advances in RNA aptamer technology to test our central hypothesis that aptamers can function as cell-targeted reagents to selectively inhibit SMC activation and deliver RNAi modulators (siRNAs and miRNAs) for the prevention of vascular disease. The rationale for these studies is based on our published data identifying aptamers that selectively internalize into SMCs and on preliminary data that a subset of these aptamers inhibits agonist-stimulated SMC migration and intimal hyperplasia in vivo.

We propose the following two specific aims:

  • Evaluate SMC-specific RNA aptamers in cultured SMCs and in animal models of vascular injury. Proposed studies will evaluate SMC-specific aptamers for their ability to inhibit SMC migration and proliferation in vitro, identify cell surface target(s) and signaling pathways involved in the effects of aptamers, and optimize binding, specificity and serum stability of aptamers in vitro. In addition, proposed studies will optimize delivery to injured vessels, define pharmacokinetics/pharmacodynamics (PK/PD), and assess the therapeutic efficacy of SMC-specific aptamers in vivo using complementary models of vascular disease.

  • Test the ability of the SMC-specific aptamers to deliver a therapeutic load (RNAi modulators) to SMCs in vitro and in animal models of vascular disease. Experiments will optimize uptake and cellular processing (endocytosis, endosomal release, RNAi processing) and serum stability of chimeras, define biodistribution, PK/PD and safety profile, and evaluate the efficacy of chimeras in vivo for attenuation of vascular disease. The proof-of-concept studies described are innovative because they represent the first thorough preclinical assessment of cell-targeted RNA therapies to be evaluated for efficacy and safety in future clinical trials in patients with CVD.

Furthermore, the successful completion of these studies will provide vital information on safety and delivery of RNA reagents in vivo and result in a foundation for the development of similar cell-targeted approaches for multiple diseases.

Research Team: Paloma H. Giangrande and Francis J. Miller (Cardiology, Duke University Medical Center)​

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Nuclease Probe

Novel diagnostic methods for characterizing the cellular and molecular makeup of metastatic breast cancer on an individualized basis (i.e., personalized medicine) have been intensively pursued in recent years due to the heterogeneity of this disease. The number of circulating tumor cells (CTCs) in cancer patients has recently been shown to be a valuable (and non-invasively accessible) diagnostic indicator of the state of metastatic breast cancer. In particular, patients with no CTCs were found to have a better overall prognosis compared to CTC-positive patients. However, the accuracy and ease-of-operation of available CTC tests remains unsatisfactory. Our proposal aims to develop a rapid and highly-sensitive CTC detection assay based on the development of chemically-modified, nuclease-activated probes that are specifically digested (i.e., activated) by target nucleases expressed in breast cancer cells. The successful outcome of the proposed work will provide a robust assay for detection of CTCs that will be straightforward to implement in most clinical diagnostic labs.

Research Team: Paloma H. Giangrande, James O. McNamara (University of Iowa), Alexandra Thomas (Univeristy of Iowa) and Howard Ozer (University of Illinois Cancer Center)

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Aptamer Inhibitors of Circulating Histones

Despite surviving major nonthoracic trauma or burns, there is a high morbidity and mortality associated with the subsequent development of multiple organ dysfunction syndrome (MODS), the lungs being the most commonly affected organ, often resulting in acute respiratory distress syndrome (ARDS) with a mortality of ~50%. There are currently only supportive treatments for MODS and ARDS. In response to cell death, histones are released from the cell nucleus into the circulation where they amplify tissue injury by killing other cells, activating Toll-like receptors, and activating platelets. Importantly, circulating histone levels are associated with mortality in humans with MODS/ARDS. We propose to identify RNA aptamers to specifically target circulating histones in order to prevent their toxic effects and reduce the morbidity and mortality of multiple organ dysfunction associated with trauma, burns, sepsis, and inhalation injury. RNA aptamers are single-stranded nucleic acids whose binding properties depend on their sequence and structure. Aptamers have high binding affinity and specificity with significant advantages over other biologics, including stability at room temperature, resistance to serum degradation, and minimal immunogenicity. Our studies will use an in vitro selection technique SELEX (Systemic Evolution of Ligands by Exponential enrichment) to isolate high affinity RNA aptamers against human histones and then test efficacy and safety in animal models of MODS. This application is innovative and high risk with the potential for paradigm shifting and high reward in the treatment of MODS and ARDS. 

Research Team: Paloma H. Giangrande, Francis J. Miller (Cardiology, Duke University Medical Center), Alejandro Comellas (University of Iowa) and Julia Klesney-Tait (University of Iowa)

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