My group is trying to address following questions:
a)How 3-methyl cholanthrene(3MC) induced increase in expression of nonmuscle myosin IIs (NM IIs) is associated with tumor formation in mice?
Subcutaneous injection of chemical carcinogen, 3’-methyl cholanthrene (3MC), induces the progressive formation of malignant sarcoma in mice within 110 d ays in hind leg. Previous reports by others suggested that transformation of muscle cells to atypical cell is one of the causes of sarcoma formation. Molecular events that lead to transformation of normal cell to atypical cell are not well understood or documented. We have demonstrated that C2C12- myotubes undergo dedifferentiation and generate mon onucleated cells in the presence of 3MC in an in vitro study. Currently, the lab is studying the fate of mononucleated cells derived from 3MC treated C2C12-myotubes.
b) What is the functional role of NM II-C1C2 in neuronal cells?
Recently, NM II-C1C2, an alternatively spliced isoform of NM II-C, has been found to be expressed only in neuronal cell, and its actin activated MgATPase activity and in vitro motility are not dependent on myosin light chain phosphorylation by myosin light chain kinase.Preliminary result from my group suggests that the expression of NM II-C1C2 is inducible in differentiated neuro-2a cells. Both RT-PCR and Immunoblot analyses reveal that expression of NM II-C1C2 reaches the maximum level between 3rd and 6th day of differentiation, and after that its expression goes down significantly. Transient over expression of NM II-C1C2 GFP in neuro-2a cells demonstrates that NM II-C1C2 is localized in the cytosol and along the neurite, specifically at points where neurite is swelled and at the tip of neurite. Inhibition of endogenous NM II-C1C2 using siRNA decreases the neurite length by 41% compare with control siRNA treatment at 72 hr. Shortening of neurite length is due to instability, which is assessed by fragmentation of neurites. Average number of neurite per cell is also decreased in NM II-C1C2 siRNA treated neuro-2a cells. During neuritogenesis, NM II-C1C2 can interact and colocalize with β1-integrin in neurites. Altogether, these studies indicate thatNMII-C1C2 may be involved in stabilizing neurites by maintaining their structure at adhesion sites. Further study is being carried out to understand signaling pathway which governs interaction between C2 insert and β1-integrin during late stage of neuritogenesis.
c) An interdisciplinary approach towards developing drugs and drug delivery systems:
We are trying to develop new drug delivery system and drug against cancer using various mammalian cell lines. In collaboration with chemists in IACS, our goal is to identify therapeutic agents (commercially available drugs, bioactive molecules used in medicine
and prodrugs etc.) for modification (either covalently or noncovalently) so as to develop next generation drugs with high specificity, and targeted drug-delivery systems.
- Shekhar has been selected for Graduate/Postdoctoral Travel Award for attending the Annual Meeting of the American Society for Biochemistry and Molecular Biology (ASBMB)-2015
- Provas has been selected for ASCB-ICGEB Travel Award for attending the Annual Meeting of the American Society for Cell Biology (ASCB)-2015