Daniel Tenant, PhD
1. Chemically modified siRNAs/ASOs for therapeutic applications:
RNA interference (RNAi) is a naturally occurring gene silencing mechanism that is mediated by RNA. Small interfering RNA (siRNA) is 21-22 nucleotides double-stranded RNA with two nucleotide 3’-overhangs. siRNAs have great potential in therapeutic applications. There are also some challenges associated with siRNA applications like nuclease susceptibility, unwanted binding to off-target due to partial complementarity, activation of unwanted immune responses, and in vivo delivery. The rational use of chemical modifications in sugar, nucleobase, and backbone of siRNAs can address most of these challenges.
Our objective is to synthesize chemically modified siRNAs and test their biochemical properties. Our primary goal is to carry out duplex stability study, serum stability study, and gene silencing studies using chemically modified siRNAs.
2. Design and development of chromogenic sensors for the detection of biologically important molecules:
We aim to develop fluorescent probes for the rapid and selective detection of environmentally and biologically important molecules.
Fluorescent probe for detection of hydrogen sulfide: H2S was considered a toxic gas for many years. After a period, along with nitric oxide (NO) and carbon monoxide (CO), H2S was recognized as endogenously produced gaseous neurotransmitters. Interestingly, H2S plays an important role in many physiological processes, such as cell growth, vasodilation, anti-inflammation, and regulation of blood pressure. Intracellular regulation of H2S is also considered as one of the potential targets for anticancer therapy as it is known to promote tumour angiogenesis and metastasis in certain cancer types. Owing to its complex biological role and its gaseous nature, accurate detection of H2S is necessary to find out its production and consumption. We are interested in developing fluorescent probes for the detection and discrimination of biothiols (H2S, Cys, Hcy, GSH, etc.). For this purpose, we designed a probe with an Acryloyl protected GFP chromophore analogue (AHBI), which is a completely novel strategy for the detection of H2S. This strategy will be more advantageous in terms of its high selectivity and sensitivity towards H2S, rapid response time, low detection limit (1000 fold lower than WHO limit), detects H2S in complete water and in live cells, high fluorescence stability, etc.
Fluorescent probe for detection of cyanide: Cyanide is one of the most toxic anions among all the anions and exhibits a strong affinity for the heme unit of cytochrome oxidase. Cyanide is widely used in many industrial applications such as metallurgy, electroplating, fishing, gold mining, production of organic chemicals and polymers, etc. We have developed a turn-on fluorescent probe based upon silyl protected modified HBI analogue for the detection of cyanide in water, on a solid support, and in living cells.
3. Computational Studies on Nucleic Acid Systems
Our molecular modeling study investigates the structural properties of various chemically modified nucleic acid systems, including RNA and DNA homoduplexes as well as DNA:RNA heteroduplexes. We examine how different chemical modifications impact ribose sugar conformation and modulate duplex structure. Using MD simulations, we also explore interactions between chemically modified functional nucleic acids and various proteins. Additionally, our research utilizes Docking and MD simulation to analyze the binding modes of small-molecule ligands that selectively stabilize distinct G-quadruplex structures. Currently, we are also studying the binding interactions between different G-quadruplexes and protein systems.