This document discusses non-coding RNAs (ncRNAs) as potential targets for drug discovery. It begins by defining ncRNAs and describing their types and functions. Several types of ncRNAs are involved in diseases like cancer. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are discussed in more detail, including their biogenesis, mechanisms of action, and roles in various diseases. The role of ncRNA in regulating immune signaling pathways during Mycobacterium tuberculosis infection is also covered. Finally, the potential for using miRNAs as diagnostic and therapeutic markers is presented.

1. NON-CODING RNA AS TARGETS
IN DRUG DISCOVERY
PRESENTED BY
LIJO MANI
PC/2022/207
NIPER-H
1

2. Outline
ncRNA
Types
Functions
Role in disease
miRNA-Biogenesis and action
miRNA in cancer
lncRNA -Types and mechanism of action
Role of ncRNA in regulation of immune signalling pathways in M.Tb
miRNA as Diagnostic and therapeutic markers
References
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3. ncRNA a transcriptional junk?
 Though 80% of the human genome is
transcribed into RNA, majority of RNA
lacks protein coding potential.
 Non coding RNA- RNA molecule that
functions without being translated into a
protein.
 Initially considered as “Transcriptional
noise”, “Junk DNA”, “Dark genomic
matter”
 Research in the past two decades has
provided convincing evidence favouring
biological roles for different types of
ncRNA in various diseases.
3
Bernard et al. Molecular biotechnology.2010
DNA RNA PROTEIN
Translation
Transcription

4. Types of ncRNA
4
Genome
Tanscriptome
Non coding
RNAs
(>80%)
Coding
RNAs
(<3%) mRNA Proteins
ncRNA
Regulatory
Small
ncRNAs(<200nt)
Long
ncRNAs(>200nt)
House
keeping
rRNA, tRNA
snRNA, snoRNA

5. Function category Role Functions
Protein synthesis
tRNA Transport of amino acids to ribosomes
rRNA Constituent of ribosomes
Transcriptional
modification, DNA
replication
snoRNA rRNA modification
snRNA Pre-mRNA splicing, rRNA processing
Regulation of gene
expression
miRNA Modulate the post-transcriptional gene expression by binding to specific
mRNA
siRNA Repress the gene expression after transcription(RNA interference)
piRNA Inhibits the function of transposon through PIWI protein
xiRNA Inactivate an X chromosome
pRNA Mediate transcriptional gene silencing and activation
lincRNA Repress the transcriptome response depend on p53
tiRNA Regulation of transcription by targeting epigenetic silencing complexes
circRNA Act as miR sponge
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6. ncRNA- Role in disease
• ncRNA have significant role in various
physiological and pathological processes.
• Differential expression of miRNA result in
either upregulation or downregulation of
their targets
• Interact with DNA, RNA or proteins to
modulate cellular process
• Potential to regulate various diseases like
cancer, neuro-degenerative, infectious,
autoimmune diseases and many more.
6
Dysregulation of miRNA is
by;
Downregulation of miRNA
expression due to mutation or
transcriptional downregulation
Overexpression of miRNA
Mutation in 3’UTR of
mRNA affect miRNA binding
site
Mutation in mRNA itself

7. miRNA
 RNA induced silencing complex(RISC)
complex targets the mRNA transcript
based on sequence complementarity b/w
miRNA sequence and 3’ UTR of target
mRNA.
 Binding leads to mRNA degradation if
homology b/w miRNA and mRNA is
extensive.
 If less, deadenylation followed by
translation prevention.
Endogenous single-stranded
sncRNA that are 18-25 nt in
length
7
Winter et al. Nat Cell Biol. 11,2009
miR biogenesis and action

8. miRNA and Cancer
• miRNA binds to 3’UTR of target genes that regulates
the cellular processes like apoptosis, cell cycle,
development, differentiation and metabolism.
• Cancer associated miR are either tumor-suppressor or
oncogenic.
• Therapeutic strategies that modulate the expression of
miRNAs in tumor acts by replenishing endogenously
depleted miRNAs(mimics) or inhibiting overexpressed
miRNA through inhibitors usually by Oligonucleotide
based approach.
• miR-7 mediated downregulation of Pak1 inhibits the
progression of breast cancer
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Tumor-suppressor miR
• miR-34a
• miR-145
• let-7 family
Oncogenic miR
• miR-21
• miR-155
miR-200c

9. 9

10. lncRNA RNA polymerase II
transcripts lacks an ORF
and are >200 nucleotides
Mechanism of actions
Types of lncRNA
10
Uchida and Dimmeler. Circ Res.2015 X Zhang. Biorg Chem;92.2019

11. 11
ncRNA
Inhibition &
Replacement
Chen et al. Sig transduction and targeted therapy;7.2022

12. Role of ncRNA in regulation of immune response
to mycobacterium tuberculosis
 Differential expression of miRs upon infection with M.tb regulates host
signalling pathways linked to inflammation, autophagy, apoptosis and
polarization of macrophages.
 M.tb utilize host miR to promote pathogenicity.
 Host-induced miR augment antibacterial processes.
 Targeting miR is an emerging option for host-directed therapies.
 In TB, the host-pathogen interaction impacts processes such as;
Apoptosis
Autophagy
Cytokine production
macrophage polarization
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Therapeutic exploration
• Manipulation of apoptosis by miRNA
agonists/antagonists
• miRNA-directed therapeutics to augment
autophagy
• Inflammatory response in macrophages
can be regulated by targeting miRNAs
which interfere with pathways linked to
macrophage polarization

13. miRNA-mediated Regulation of phagocytosis
During infection of macrophages with M.tb there is an increase in miR-
142-3p which directly targets N-wiskott-Aldrich syndrome protein (N-
WASp) to inhibit actin assembly
miRNA –mediated regulation of autophagy
Downregulation of Ca2+ by miR-27a-targets the Ca2+ transporter, voltage-
dependent calcium channel subunit alpha2delta to limit Ca2+ entry into the
cytoplasm-inhibits autophagy promoting survival of M.tb in
macrophages.
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14. miRNA as diagnostic and therapeutic markers
• Examining miRNA profile in TB patients prior to and following
treatment. A Change is associated with therapeutic response.
• miR profile in serum can be used as a biomarker for diagnosis(eg. miR
125a-5p elevated in Tb, miR-16 decrease in MDT)
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Exosomal miR
as diagnostic
marker
• miR-484
• miR-425
• miR-96-3-p

15. Function ncRNA Actions
Etiology
miR 155-5p
miR 29-3p
Inhibition of innate immunity
miR 20b-5p
miR 21-5p
Suppression of inflammation
miR 125 a-3p
miR 144-5p
Inhibition of phagosome maturation and
autophagy
miR 155-5p
miR 582-5p
Apoptosis inhibition
Diagnosis
miR 17-5p
miR 20b-5p
Upregulation in TB patients
miR 320-a
miR 22-3p
Downregulation
Treatment
lncRNAs NEAT 1
lncRNAs NEAT 2
Downregulation during drug treatment, linked
with disease improvement
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16. REFERENCES
1. Almatroudi A et al. Non-Coding RNAs in Tuberculosis Epidemiology: Platforms
and Approaches for Investigating the Genome's Dark Matter. Int J Mol Sci. 2022.
2. Singh et al. Role of various non-coding RNAs in EMT, cancer and metastasis:
Recent trends and future prospective. Adv in cancer biology-metastasis;4:2022.
3. X. Zhang et al. The role of long noncoding RNA in major human disease.
Bioorganic chemistry;92.2019.
4. Toden et al. Non-coding RNAs and potential therapeutic targeting in cancer;
Biochim Biophys Acta Rev Cancer;1875(1).2021.
5. Palazzo AF and Lee ES. Non-coding RNA: What is functional and what is junk?;
Frontiers in genetics.2015.
6. Wei Li et al. the roles of host noncoding RNAs in mycobacterium tuberculosis
infection; Front.Immunol. May 2021.
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17. • 7. Miura, Shiori & Himaki, Takehiro & Takahashi, Junko & Iwahashi, Hitoshi.the
role of transcriptomics: physiological equivalence based on gene expression
profiles. Reviews in Agricultural Science.2017
• 8. Winter, J., Jung, S., Keller, S. et al. Many roads to maturity: microRNA
biogenesis pathways and their regulation. Nat Cell Biol 11, 228–234 (2009)
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