Recent Discoveries at UMMS
UMass Medical School granted US patent related to RNA technology
Issued April 6, 2010, the United States Patent 7,691,995, entitled, “In Vivo Production of Small Interfering RNAs That Mediate Gene Silencing,” is based on research performed at UMMS by co-inventors Phillip D. Zamore, PhD, Howard Hughes Medical Institute Investigator and the Gretchen Stone Cook Professor of Biomedical Sciences; Craig C. Mello, PhD, Howard Hughes Medical Institute Investigator, the Blais University Chair in Molecular Medicine and 2006 Nobel Laureate; Juanita McLachlan and Gyorgy Hutvagner, members of the Zamore laboratory; and Alla Grishok from the Mello laboratory.
The patent claims cover a powerful technique drawing on a fundamental mechanism in basic biology: using naturally occurring, endogenous microRNA (miRNA) precursors as templates for designing siRNAs to selectively modulate expression of a target gene. This method has found broad application as a tool for gene discovery and analysis in basic research and drug discovery, where such constructs are often called shRNAs or miRNA-based shRNAs.
NEJM publishes results of Phase 2 clinical trial testing novel antibodies to treat Clostridium difficile infection (CDI)
A combination of two fully human monoclonal antibodies developed by MassBiologics (MBL) of UMMS and Medarex, a wholly owned subsidiary of Bristol-Myers Squibb Co. (NYSE:BMY), when given with standard antibiotics, was shown to reduce recurrence of a debilitating form of diarrhea by 72 percent in patients enrolled in a Phase 2 clinical trial. The results are reported in the article “Treatment with Monoclonal Antibodies against Clostridium difficile Toxins” published January 21, 2010 in the New England Journal of Medicine (NEJM). Donna Ambrosino, MD, executive director of MassBiologics, professor of pediatrics at UMMS is the senior author of the paper. Clostridium difficile (C. difficile) is a common bacterium that can colonize the human gastrointestinal tract and produce large amounts of two toxins that can cause severe diarrhea and damage the lining of the large intestine. The incidence of CDI in the US is rapidly increasing, with rates doubling from 2000 to 2005.
Discovery of a novel therapeutic agent for the treatment of malignant melanoma
Dr. Michael Green, Professor of Gene Function and Expression, Investigator, Howard Hughes Medical Institute is Director of the RNAi Reagent Core Facility. Dr. Green performed a genome-wide RNAi screen to identify genes required for oncogene BRAF-mediated senescence/apoptosis. He identified 17 different genes, including IGFBP7, an insulin-like growth factor binding protein. This secreted protein is turned off in malignant melanomas with a mutation in the BRAF oncogene. Treatment of these malignant melanomas with IGFBP7 in vitro and in vivo results in apoptosis of the tumor cells.
Development of an oral delivery mechanism for RNAi therapeutics
Drs. Michael Czech and Gary Ostroff in the Program in Molecular Medicine have been able to encapsulate siRNAs in particles composed of yeast cell wall glucan. Their experiments have demonstrated that these particles can be orally delivered to mice and protect mice from lethal challenge with lipopolysaccharide (LPS) by siRNA silencing of tumor necrosis factor alpha (TNFα) the mediator of LPS induced lethal shock.
Consultation with the UMCCTS Co-Pilot Program led to the collaboration between the Czech/Ostroff laboratories and Dr. Ellen Gravallese who studies immunologic mechanisms in arthritis models. These investigators successfully applied to the UMCCTS Pilot Project Program and received funding to study the oral delivery of siRNA directed at silencing the TNFα gene in the mouse model of arthritis.
Development of RNAi Therapy for the treatment of amyotrophic lateral sclerosis (ALS)
Dr. Robert Brown, Professor and Chair, Department of Neurology is one of the world’s authorities on ALS. Dr. Brown’s laboratory identified one of the genes associated with ALS, cytosolic superoxide dismutase, or SOD1. Current views suggest that the mutation of SOD1 causes misfolding of the SOD1 protein and resulting toxicity to the neuron.
Recent studies by Dr. Zuoshang Xu, Professor of Biochemistry and Molecular Pharmacology have demonstrated that RNAi molecules can silence mutant SOD1 in vivo and increase survival time in the mouse model of ALS. Drs. Brown and Xu have collaborated in the design of RNAi molecules for a trial in humans with mutant SOD1 associated ALS. First in human studies of RNAi in ALS are currently underway at UMass.