Achievements

  • Overexpression of hsa-miR-29a, a computationally predicted anti-HIV miRNA, resulted in downregulation of the nef gene and reduction of the virus levels in a cell culture based HIV1 infection model.  Further, it was hypothesised that the expression level of this miRNA could be a prognostic indicator of disease progression.  A collaborative project to identify Long term non-progressors in the Indian population was initiated with YRGCARE, Chennai, an NGO working with HIV patients.  13 LTNPs, and a comparable number of rapid progressors and normal controls have been registered for the study.  Preliminary results indicate that the level f the miRNA is indeed higher in LTNPs compared to rapid progressors.
  • A novel molecule, designed by incorporating the features of modified backbone nucleic acids and ribozymes for degradation of specific miRNAs was developed and tested.  The results show that these molecules called antagomiRzymes maybe used to regulate miRNA levels in cultured cells.AntagomiRzymes against a series of miRNAs were developed and are being tested in vivo using a zebrafish model.
  • We found that the mouse beta-actin locus gene can give rise to two alternative polyadenylated transcripts, of which only one is susceptible to regulation by an miRNA expressed in a tissue specific manner.
  • The existence and regulatory potential of a RNA quadruplex in the 5’UTR of the ZIC1 gene was demonstrated. Currently, quadruplexes are being identified in lncRNAs.
  • Targeting by a miRNA cluster, miR-23a-27-24_2 at the key steps of an apoptosis pathway was demonstrated. Since then, the involvement of other miRNAs in cancer has also been studied.
  • A conceptual framework for the role of miRNAs in incomplete penetrance and variable expressivity was developed and a model for the same published.  This model was then experimentally tested and proven.
  • Our studies have revealed that the binding of coralyne and sanguinarine induced self structure in poly(A) molecules.
  • Binding of alkaloids to small RNA was extensively characterized.  The alkaloids berberine, palmatine and coralyne to double stranded (ds) RNA polymers poly(A).poly(U), poly(I).poly(C) and poly(C).poly(G) showed co-operative binding with affinity in the order 104 M-1.
  • A library of dimeric to tetrameric carbohydrate molecules were planned to synthesize with multiple amine groups being displayed on their peripherial sites so that they can have interactions with targeted miRNA.   Interesting observations while performing this investigation resulted in the identification of a novel glycosyl donor.
  • Covalent grafting of simple Tris-base component of the widely used biological Tris buffer in the headgroup region is capable of imparting high serum compatibility and intravenous mouse lung transfection properties to cationic amphiphile.
  • A novel RGDK-lipopeptide 1 that selectively targets R5_1 integrin and is capable of targeting genes to mouse tumor vasculatures was developed. Artificial miRNAs have been designed and validated against angiogenesis related genes. The artificial miRNA, was expressed in vivo in mouse models of angiogenesis and regression of tumours demonstrated.
  • Modified backbone oligonucleotides developed at NCL were tested for their biological effect.
  • Regulation of miRNAs: Identification of miRNA promoters was done using integrated analysis of miRNA exprerssion data and nucleosome positioning.
  • miRNA proteomics was adopted as a novel method of miRNA target identification.  Although the limitation in number of identifiable proteins prevented a global analysis, we identified VDACs as potential targets of miR-29a.
  • The role of miRNAs in vasculature in a Zebrafish model.
  • Involvement of miRNA in neurodegeneration and metabolic disorders like diabetes.  We found the miRNA, miR-29a to be involved in neurodegeneration mediated by polyglutamine expansion.  Bace1 a well know alzheimer’s target was found to be a common target in other types of neurodegeneration also.
  • Emerging areas:

·         Mathematical modelling of gene regulation by miRNAs.

·         Engineering of artificial networks with predictable properties using miRNAs.

·         The effect of cellular environment in miRNA expression.

·         Delineation of physicochemical principles governing miRNA-mRNA interaction

·         Repeat associated miRNAs

·         Initiation of clinical studies with cancer samples.

·         Initiation of clinical studies with Down’s syndrome patients

 

  

Analysis of Publications

 

Average Impact Factor

5.3

Total number fo citations

238*

*as on 6th July 2011

 

Deliverables

Deliverable

Projected

Achieved

Comments

Publication

60-80

53

Diagnostic marker

1

Clinical Samples

Collaboration with YRGCARE has to be formalized and continued beyond the project term

Delivery system

1-3

1 patent

IICT

Detection or modulation method

1

1 publication

In vivo testing will continue beyond the term of the project

Manpower development

50 trainees, 20 young researchers, 15 Ph.Ds

Achieved

 

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