Recently we have developed a new class of peptide nucleic acid called GPNA that is readily taken up by both human somatic and embryonic stem cells, and binds sequence specifically to DNA and RNA. GPNA designed to bind to the transcription and translation start site of the gene transcript elicited potent antisense effect with unusually low cytotoxicity compared to the unmodified PNA and its other derivatives. The proposed research will explore the scope of this particular class of molecules and establish a basic understanding of the factors and mechanisms that control cellular uptake, hybridization and cytotoxicity over a wide range of cell lines, including human ES cells. Specifically, we aim to accomplish four specific objectives within the next five years.
Aim 1 (Section D.1): Evaluate the antisense effects of GPNA with human somatic and ES cells;
Aim 2 (Section D.2): Optimize cellular uptake, hybridization and cytotoxicity.
Aim 3 (Section D.3): Determine the mechanism of GPNA uptake and cytotoxicity.
And Aim 4 (Section D.4): Determine the scope of GPNA in regulating gene expression. ? ? The proposed study is crucial to the future design and development of nucleic acid mimics for a safe and effective use in animals and in humans. GPNA is, to the best of our knowledge, the first example of nucleic acid analogue taken up by human ES cells. This is intriguing because these primitive cells are extremely difficult to penetrate and are sensitive to the environmental cues. Human ES cells hold the key to understanding early human development that can neither be studied directly in utero nor fully understood with animals model, not to mention its enormous potential for regenerative medicine. Many fascinating questions concerning human ES cell proliferation, differentiation, cellular lifespan and so forth have not yet been addressed. Furthermore, recent evidence suggests that cancers may arise from stem cells. If this proves to be correct, it will alter the course of cancer treatment. Before we can begin to address these questions, an effective method must be developed to regulate gene expression in these and related cell types - this is the aim of our research. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM077261-01
Application #
7076593
Study Section
Synthetic and Biological Chemistry A Study Section (SBCA)
Program Officer
Fabian, Miles
Project Start
2006-05-01
Project End
2011-04-30
Budget Start
2006-05-01
Budget End
2007-04-30
Support Year
1
Fiscal Year
2006
Total Cost
$238,888
Indirect Cost
Name
Carnegie-Mellon University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
052184116
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Manna, Arunava; Rapireddy, Srinivas; Sureshkumar, Gopalsamy et al. (2015) Synthesis of optically pure ?PNA monomers: a comparative study. Tetrahedron 71:3507-3514
Thomas, Sufi M; Sahu, Bichismita; Rapireddy, Srinivas et al. (2013) Antitumor effects of EGFR antisense guanidine-based peptide nucleic acids in cancer models. ACS Chem Biol 8:345-52
Sahu, Bichismita; Sacui, Iulia; Rapireddy, Srinivas et al. (2011) Synthesis and characterization of conformationally preorganized, (R)-diethylene glycol-containing ?-peptide nucleic acids with superior hybridization properties and water solubility. J Org Chem 76:5614-27
Crawford, Matthew J; Rapireddy, Srinivas; Bahal, Raman et al. (2011) Effect of Steric Constraint at the ?-Backbone Position on the Conformations and Hybridization Properties of PNAs. J Nucleic Acids 2011:652702
Rapireddy, Srinivas; Bahal, Raman; Ly, Danith H (2011) Strand invasion of mixed-sequence, double-helical B-DNA by ýý-peptide nucleic acids containing G-clamp nucleobases under physiological conditions. Biochemistry 50:3913-8
Yeh, Joanne I; Shivachev, Boris; Rapireddy, Srinivas et al. (2010) Crystal structure of chiral gammaPNA with complementary DNA strand: insights into the stability and specificity of recognition and conformational preorganization. J Am Chem Soc 132:10717-27
Sahu, Bichismita; Chenna, Venugopal; Lathrop, Kira L et al. (2009) Synthesis of conformationally preorganized and cell-permeable guanidine-based gamma-peptide nucleic acids (gammaGPNAs). J Org Chem 74:1509-16
He, Gaofei; Rapireddy, Srinivas; Bahal, Raman et al. (2009) Strand invasion of extended, mixed-sequence B-DNA by gammaPNAs. J Am Chem Soc 131:12088-90
Zhou, Peng; Dragulescu-Andrasi, Anca; Bhattacharya, Birendra et al. (2006) Synthesis of cell-permeable peptide nucleic acids and characterization of their hybridization and uptake properties. Bioorg Med Chem Lett 16:4931-5
Dragulescu-Andrasi, Anca; Rapireddy, Srinivas; He, Gaofei et al. (2006) Cell-permeable peptide nucleic acid designed to bind to the 5'-untranslated region of E-cadherin transcript induces potent and sequence-specific antisense effects. J Am Chem Soc 128:16104-12