Putting a study's model system into perspective.
Getting to know the model system used in a scientific study is often the key to understanding the broader implication of its findings.
By explaining the strength and/or limitation of a study's model system, a reporter can present and explore a study’s implication(s) in a more powerful way. The model system used - whether cells, tissues, animals or some combination of these - can often help readers interpret the study’s conclusion in a bigger picture or to become aware of its limitation.
Journalist Tara Parker-Pope writes in a New York Times online blog about the ability of bisphenol A (BPA) to reduce the effectiveness of chemotherapeutic agents used in treating cancer. Her report is based on a paper published online in the journal Environmental Health Perspectives.
The article summarizes the study and concisely highlights its main findings. She presents the study's key points right on target, including its conclusion (“reduce the effectiveness of chemotherapy treatment”), doses used (“low levels of BPA similar to those found in the blood of adults”) and mechanism (“inducing proteins that protect the cells from chemotherapy agents”).
What's missing is a broader context from the study based on the type of animal or cell model the researchers chose for the experiments. Ms. Parker-Pope writes that the study uses human breast cancer cells as the model system. As a reader, I wondered if BPA would affect other types of cancer, too.
In this study, both estrogen sensitive and estrogen insensitive human breast cancer cells were used as model systems. BPA affected both cell types. After a little more research on cancer literature, I also learned that these cell lines contain some receptors that are known to be involved in other types of cancers. The receptors are found and expressed in the brain, heart, leukocytes, ovary and uterus.
Therefore, BPA-induced effects seen in this study most likely may be applicable to other cancers. Including this type of information, even briefly, would be very useful to further understand the bigger context of the study. While working together, journalists should ask and scientists should explain the model system's extentions and limitations.
