Lawrence Berkeley National Laboratory researchers lead cancer study

Weiguo Zhang/Courtesy

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A new study led by researchers at the Lawrence Berkeley National Laboratory may help doctors recommend more appropriate treatment options for cancer patients.

The study — published Wednesday in Nature Communications — identifies a correlation between patient survival and over-expression of specific centromere proteins in 14 genes, according to lead study author Weiguo Zhang, a project scientist at the Berkeley lab. The study found that gene over-expression is typically linked to a worse prognosis, but is also associated with a more positive response to gene-damaging treatments, like chemotherapy and radiation.

Conversely, lower gene-expression levels were associated with better prognoses  but poorer response to the gene-damaging therapies. The study applied to nine different cancers and 31 centromere proteins.

“Cancer is a really, really complex disease … it’s very difficult to generalize in that sense,” said Lin He, campus associate professor of cell and developmental biology. “The hope is that the finding can apply to a number of cancer types, not just the one that they started with.”

Currently, doctors largely rely on tumor stage, tumor grade, patient age and other clinical factors when determining which treatment to recommend, Zhang said. Gene over-expression is a potential biomarker doctors can use to predict how a patient might respond to particular therapies.

According to Gary Karpen, the study’s principal investigator and a senior scientist at the Berkeley lab, clinicians often tend to err on the side of over-treatment rather than tailoring treatment to what may work best in a patient’s specific situation.

“For early stage breast cancer, up to 50 percent of the cancer patients have been over-treated,” Zhang said. “Those patients should be spared from their aggressive treatment.”

Gene-damaging therapies kill cancer cells, but also any other kind of cell undergoing replication, Karpen said, including hair cells and cells in the digestive system. These treatments also tend to have long-term negative effects and may induce the development of other kinds of cancer.

“You have to weigh the potential damage of the therapy against the prognosis of the patient,” Karpen said.

The researchers began first by studying gene over-expression in fruit flies and then began studying the phenomena in humans. They used publicly available databases to look at the expression of genome samples and collaborated with statisticians who helped them to manage the data.

“The reality is that we did this without funding that was directly for this study,” Karpen said. “Early on, we basically just did this in our spare time.”

The team plans to continue their research with more patient samples to validate their findings and find ways to apply their research to the clinical field of medicine. They will work in partnership with Biopharmaceutical Valley, located in the Nanjing High Tech Zone in China.

Jessica Lynn is an assistant news editor. Contact her at [email protected] and follow her on Twitter at @jessicailynn.

A previous version of the same article incorrectly stated that doctors rely largely on tumor age when determining which treatment to recommend. In fact, doctors rely on tumor grade, among other clinical factors.

A previous version of this article incorrectly quoted Weiguo Zhang as saying that up to 50 percent of breast cancer patients were overtreated. In fact, Zhang said that 50 percent of early stage breast cancer patients were overtreated.
A previous version of this article incorrectly stated that the researches will work in partnership with Biopharmaceutical Valley and Nanjing High Tech Zone in China. In fact, they will work in partnership with Biopharmaceutical Valley, which is in the Nanjing High-Tech Zone in China.