Gene fusion that could explain a significant proportion of lung cancer cases in never-smokers has been identified by researchers.
Recent strides have been made to identify gene mutation events driving cases of lung adenocarcinoma in never-smokers, but the underlying genetic events leading to these lung cancers still remain unknown in a large number of cases. In this report, using a combination of genome sequencing and RNA sequencing, a team of researchers in South Korea has characterized a previously unknown gene fusion event in a case of lung adenocarcinoma striking a 33-year-old Korean male with no history of smoking or cancer within his family.
The group sequenced and compared the genome of the patient's cancer and normal tissue (blood), but they found no mutations in known-cancer related genes, such as EGFR, KRAS, and EML4-ALK mutations, that were likely to explain this case. Delving deeper, they also sequenced RNA isolated from the cancer cells, which when analyzed, can reveal gene rearrangement events that are difficult to detect by genome sequencing and may be driving the cancer.
They then confirmed that the KIF5B-RET fusion occurs in other lung cancer cases, finding two instances in twenty additional cases of lung cancer, indicating that this fusion event is not rare. The authors suggest that the KIF5B-RET fusion occurs in about 6% of all lung adenocarcinoma cases. The authors note that although further epidemiological studies are needed to accurately define the frequency of KIF5B-RET in lung cancers, they expect that the fusion gene may be a promising molecular target for treatment.
"We showed that genome sequencing technology could reveal a previously hidden cause of human cancer, which can be used as a therapeutic target for personal cancer therapy", said Dr. Jeong-Sun Seo, director of the Genomic Medicine Institute-Seoul National University, chairman of Macrogen Inc., and senior author of the study.