Two MicroRNAs Are Linked to Lung Cancer

A new study shows that the expression pattern of certain microRNAs (miRNAs) is predictive of tumor aggressiveness in some patients with lung cancer.

These miRNAs are small segments of genetic material called ribonucleic acid (RNA), whose actions can change the expression of cancer-related genes within a cell and lead to malignancies. A team of researchers identified two miRNAs, "has-mir-155” and "has-let-7a-2” that could be used as prognostic indicators in patients with adenocarcinoma, a malignancy of the mucous glands in the lung. The study was the result of a collaboration among researchers at the Ohio State University Comprehensive Cancer Center (Columbus, Ohio, USA), the Jikei University School of Medicine (Tokyo, Japan), and the Center for Cancer Research at the U.S. National Cancer Institute (NCI, Bethesda, MD, USA). The results of the study appear in the March 2006 issue of the journal "Cancer Cell.”

High levels of "has-mir-155” or low levels of "has-let-7a-2” were associated with poor prognosis in the lung cancer patients. Overexpression of "has-mir-155” or the signaling of the miRNA to change the amount of a protein produced was the most significant indicator of this prognosis, independent of tumor stage. These miRNAs have been identified in other cancers but this is the first time”has-mir-155” has been linked to lung cancer.

Dr. Curtis Harris, chief of the laboratory of human carcinogenesis at NCI and co-leader of the study, noted that "in the future we can use miRNAs and other biological predictors to select patients who may need more-aggressive therapy.” He believes that miRNAs are going to be important biomarkers of not only diagnosis and prognosis, but therapy, as well. However, further testing will be required before these markers can be used for predicting patient outcomes.



Related Links:
Ohio State U. Comprehensive Cancer Center
Jikei University School of Medicine
NCI