UB Study Visually Depicts Anti-Cancer DNA Repair Process

Published August 14, 2013

piero bianco.

Piero R. Bianco, PhD

Piero R. Bianco, PhD, associate professor of microbiology and immunology, will use a $1.8 million grant to develop the first clear model of a biochemical DNA repair mechanism needed to stave off cancer.

Bianco’s project seeks to understand how enzyme-related processes contribute to the regression and subsequent restoration of stalled DNA replication forks.

His four-year grant is from the National Institute of General Medical Sciences.

Defective Cell Machinery Leads to Mutations

“Understanding how stalled DNA replication forks are rescued is important because defects in these repair mechanisms lead to the accumulation of mutations that, in turn, lead to cancer.”
Piero R. Bianco, PhD
Associate professor of microbiology and immunology

Bianco’s research will illuminate cellular repair-and-restart processes that occur as cells copy, or replicate, their DNA.

During this process, the cellular machinery derails when it encounters DNA damage or other types of blockages, Bianco explains.

“Repair enzymes must then fix the roadblock and get DNA replication going again,” he says. “If this fails, the cell dies or turns into a cancerous cell.”

Therefore, “understanding how stalled DNA replication forks are rescued is important, as defects in these repair mechanisms in higher organisms lead to the accumulation of mutations that, in turn, lead to cancer,” Bianco explains.

“Our contribution is significant because it will allow, for the first time, a clear understanding into the range of events that transpire to reactivate a stalled DNA replication fork in vivo,” he says.

First Real-Time Visual Models

Bianco will use innovative techniques to visually depict how stalled DNA replication forks regress and are subsequently restored.

Using bulk-phase biochemistry, atomic force microscopy and a novel fluorescence-based single molecule technique he developed, Bianco aims to determine the mechanism of key recombination helicases—enzymes that separate DNA helix strands—in fork reactivation.

This will clarify how these enzymes bind to and process fork substrates that mimic both stalled and regressed forks.

Critical to the success of the project is the use of two novel, single DNA molecule approaches to produce high-resolution, “real-time movies” of the molecular events occurring at stalled DNA replication forks, Bianco says.

Bianco is collaborating with Yuri Lyubchenko, PhD, professor of pharmaceutical sciences at the University of Nebraska Medical Center.