Nav: Home

A cancer drug may help treat human papillomavirus infections

November 30, 2018

BIRMINGHAM, Ala. - Preclinical experiments by University of Alabama at Birmingham researchers suggest the cancer drugs vorinostat, belinostat and panobinostat might be repurposed to treat infections caused by human papillomaviruses, or HPVs.

HPV infections caused an estimated 266,000 deaths from cervical cancer worldwide in 2012, according to the World Health Organization. Routine screening by Pap smears or HPV DNA tests has reduced death rates in developed countries compared to less developed regions of the globe. Still, an estimated 12,200 United States women are diagnosed with cervical cancer each year.

Highly efficacious vaccines against HPV infection exist -- including the recently approved Gardasil 9, which immunizes against nine genotypes of HPV known to cause cervical, vulvar, vaginal and anal cancers, and genital warts. But the vaccine needs to be given before a person becomes sexually active, since it has no therapeutic efficacy against existing HPV infections.

"Safe, effective and inexpensive therapeutic agents are urgently needed," said N. Sanjib Banerjee, Ph.D., assistant professor of Biochemistry and Molecular Genetics at UAB and lead author of the vorinostat study.

Epithelium of anogenital sites -- the cervix, penis and anus -- or epithelium of the mouth and throat are sites of HPV infection. But HPVs cannot be propagated in conventional cell culture, hampering the investigation into their pathogenic effects. The laboratory of Louise Chow, Ph.D., and Thomas Broker, Ph.D., in the UAB Department Biochemistry and Molecular Genetics has investigated HPV-host interactions for decades. They discovered that the productive program of HPV depends on differentiation of the epithelium into a full-thickness, squamous epithelium. Furthermore, HPV reactivates host DNA replication in these differentiated cells, such that the replication proteins and substrates become available to support viral DNA amplification.

The Chow and Broker lab re-produced a fully differentiated human squamous epithelium by culturing primary human keratinocytes at an air-media interphase for two to three weeks, a growth they call raft culture. In 2009, their lab developed a breakthrough model for a raft culture of HPV-18-infected primary human keratinocytes, allowing a robust amplification of HPV-18 DNA and production of infective viral progeny. This productive raft culture is an ideal model for preclinical investigation of potential anti-HPV agents.

Banerjee and colleagues hypothesized that inhibitors of histone deacetylases, or HDACs, would inhibit HPV DNA amplification because of their known mechanism of disrupting chromosomal DNA replication. Chromosomal replication requires HDAC alterations of histone proteins, the proteins that act like spools that wind DNA to help package and condense chromosomes and the viral genome. Vorinostat inhibits many HDACs, so it might interrupt not only chromosomal replication but also viral DNA replication.

Using the HPV-18 model raft cultures, the researchers found that vorinostat effectively inhibited HPV-18 DNA amplification and virus production. Importantly, vorinostat also induced the programmed cell death called apoptosis in a fraction of the differentiated cells. Cell death could be attributable to DNA breakage when chromosomal DNA replication was interrupted. Similar results were obtained with two additional HDAC inhibitors, belinostat and panobinostat. In contrast, the differentiated cells of uninfected raft cultures, which do not replicate their DNA, were thus largely spared in the presence of the inhibitors.

The UAB team also examined how vorinostat affected levels and functions of viral oncoproteins, and they described the mechanisms that led to programmed cell death in HPV-18-infected cultures. "On the basis of these detailed studies," Banerjee said, "we suggest that HDAC inhibitors are promising compounds for treating benign HPV infections, abrogating progeny production and hence interrupting infectious transmission."

The UAB team also reported that vorinostat caused extensive cell death in raft cultures of dysplastic and cancer cell lines harboring HPV-16. HPV-16 and HPV-18 are the most prevalent, high-risk HPVs responsible for causing anogenital and oropharyngeal cancers. "But further investigation would be required to verify that these agents could also be useful in treating HPV associated dysplasias and cancers," Banerjee said.
-end-
Authors of the paper, "Vorinostat, a pan-HDAC inhibitor, abrogates productive HPV-18 DNA amplification," published in Proceedings of the National Academy of Sciences, are Banerjee, Chow, Broker and Dianne W. Moore, UAB Department of Biochemistry and Molecular Genetics.

Support came from National Institutes of Health grant CA83679, UAB Comprehensive Cancer Center/HIV-Associated Malignancy Pilot Grant 316851, UAB Comprehensive Cancer Center Pilot Grant 5P30CA013148-43 and UAB Bridge Funding.

At UAB, Chow holds the Anderson Family Chair in Medical Education, Research and Patient Care in the School of Medicine.

University of Alabama at Birmingham

Related Dna Articles:

Zigzag DNA
How the cell organizes DNA into tightly packed chromosomes. Nature publication by Delft University of Technology and EMBL Heidelberg.
Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.
DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.
A new spin on DNA
For decades, researchers have chased ways to study biological machines.
From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.
Self-healing DNA nanostructures
DNA assembled into nanostructures such as tubes and origami-inspired shapes could someday find applications ranging from DNA computers to nanomedicine.
DNA design that anyone can do
Researchers at MIT and Arizona State University have designed a computer program that allows users to translate any free-form drawing into a two-dimensional, nanoscale structure made of DNA.
DNA find
A Queensland University of Technology-led collaboration with University of Adelaide reveals that Australia's pint-sized banded hare-wallaby is the closest living relative of the giant short-faced kangaroos which roamed the continent for millions of years, but died out about 40,000 years ago.
DNA structure impacts rate and accuracy of DNA synthesis
DNA sequences with the potential to form unusual conformations, which are frequently associated with cancer and neurological diseases, can in fact slow down or speed up the DNA synthesis process and cause more or fewer sequencing errors.
Changes in mitochondrial DNA control how nuclear DNA mutations are expressed in cardiomyopathy
Differences in the DNA within the mitochondria, the energy-producing structures within cells, can determine the severity and progression of heart disease caused by a nuclear DNA mutation.
More DNA News and DNA Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Space
One of the most consistent questions we get at the show is from parents who want to know which episodes are kid-friendly and which aren't. So today, we're releasing a separate feed, Radiolab for Kids. To kick it off, we're rerunning an all-time favorite episode: Space. In the 60's, space exploration was an American obsession. This hour, we chart the path from romance to increasing cynicism. We begin with Ann Druyan, widow of Carl Sagan, with a story about the Voyager expedition, true love, and a golden record that travels through space. And astrophysicist Neil de Grasse Tyson explains the Coepernican Principle, and just how insignificant we are. Support Radiolab today at Radiolab.org/donate.