Related Experiment Video

Updated: Aug 18, 2026

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2'-O-thiophenylmethyl Modification and Characterization via Circular Dichroism
11:37

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2'-O-thiophenylmethyl Modification and Characterization via Circular Dichroism

Published on: July 28, 2017

Biologic activity of oligonucleotides with polarity and anomeric center reversal

T M Tan1, B W Kalisch, J H van de Sande

  • 1Institute of Molecular and Cell Biology, National University of Singapore, Singapore.

Antisense & Nucleic Acid Drug Development
|May 21, 1998
PubMed

Insights

Antisense oligodeoxynucleotides targeting human papillomavirus (HPV) type 16 E6 and E7 genes inhibited cervical cancer cell growth and reduced tumor size in mice. These modified DNA molecules show potential for HPV-related cancer therapy.

Area of Science:

  • Molecular Biology
  • Virology
  • Anticancer Drug Development

Background:

  • Human papillomavirus (HPV) type 16 oncoproteins E6 and E7 inactivate tumor suppressors p53 and pRB, crucial for maintaining cellular transformation.
  • Targeting these viral oncoproteins is a key strategy in developing therapies for HPV-associated cancers.

Purpose of the Study:

  • To investigate the antisense activity of novel alpha/beta-oligodeoxynucleotides (ODNs) against HPV type 16 E6 and E7 genes.
  • To evaluate the efficacy of these alpha/beta-ODNs in inhibiting cervical carcinoma cell growth and tumor development in vivo.

Main Methods:

  • Synthesis of alpha/beta-ODNs complementary to start codon regions of HPV 16 E6 and E7 genes using phosphoramidite DNA chemistry.
  • Assessing the ability of alpha/beta-ODNs to form stable RNA duplexes and undergo RNase H hydrolysis.
  • Evaluating the inhibition of cervical carcinoma cell lines (CaSki and SiHa) growth and E7 protein expression in vitro.
  • Testing the therapeutic effect of alpha/beta-ODNs on tumor growth in nude mice xenografted with SiHa cells.

Main Results:

  • Synthesized alpha/beta-ODNs formed stable duplexes with target RNA, serving as substrates for RNase H.
  • Anti-HPV type 16 alpha/beta-ODNs specifically inhibited the growth of CaSki and SiHa cervical cancer cell lines.
  • A reduction in HPV 16 E7 protein expression was observed in treated cells.
  • Treatment with alpha/beta-ODNs significantly reduced tumor size in mice bearing SiHa cell xenografts.

Conclusions:

  • Alpha/beta-ODNs demonstrate effective antisense activity against HPV type 16 E6 and E7 genes both in vitro and in vivo.
  • These findings support the potential of alpha/beta-ODNs as a therapeutic strategy for HPV type 16-associated cervical cancers.

More Related Videos

Sequence-specific and Selective Recognition of Double-stranded RNAs over Single-stranded RNAs by Chemically Modified Peptide Nucleic Acids09:04

Sequence-specific and Selective Recognition of Double-stranded RNAs over Single-stranded RNAs by Chemically Modified Peptide Nucleic Acids

Published on: September 21, 2017

Chemical Triphosphorylation of Oligonucleotides13:19

Chemical Triphosphorylation of Oligonucleotides

Published on: June 2, 2022

Related Concept Videos

Molecular Shape and Polarity03:37

Molecular Shape and Polarity

Dipole Moment of a Molecule
DNA Topoisomerases02:02

DNA Topoisomerases

Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types.  Type I...
Conservative Site-specific Recombination and Phase Variation02:53

Conservative Site-specific Recombination and Phase Variation

Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
SN1 Reaction: Stereochemistry02:15

SN1 Reaction: Stereochemistry

This lesson provides an in-depth discussion of the stereochemical outcomes in an SN1 reaction.
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
Nuclear Overhauser Enhancement (NOE)01:06

Nuclear Overhauser Enhancement (NOE)

Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling. This phenomenon, called the nuclear Overhauser enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring spin-active...
Nucleic Acid Structure01:25

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms  a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA has a double-helix structure. The...