Sequencing of small-cell lung cancer exomes

The exomes of 82 small-cell lung cancer samples from patients have been sequenced and analyzed, according to two independent reports published online this week in Nature Genetics. The studies identify several potential targets for therapeutic intervention.

Small-cell lung cancer (SCLC) is an aggressive type of tumor with poor prognosis. This type of cancer is rarely treated by surgery, making systematic genomic analyses of large numbers of tumors difficult. For the first time, two groups have sequenced the exomes from a total of 82 small-cell lung cancer samples and identified new genes recurrently mutated in this type of cancer.

Roman Thomas and colleagues sequenced 29 SCLC exomes and identified mutations in a number of genes involved in histone modification. Somasekar Seshagiri, Charles Rudin and colleagues sequenced the exomes of 36 primary SCLC tumors and 17 SCLC cell lines, individually derived from SCLC tumors. They identified 22 significantly mutated genes, including genes that encode kinases, G-protein coupled receptors and chromatin modifying proteins. They also identified amplification of the SOX2 gene in 27% of samples, suggesting SOX2 has an important role as a cancer-causing gene in small cell lung cancer.