John D. Carpten

Multiple myeloma is an incurable malignancy of plasma cells, and its pathogenesis is poorly understood. Here we report the massively parallel sequencing of 38 tumour genomes and their comparison to matched normal DNAs. Several new and unexpected oncogenic mechanisms were suggested by the pattern of somatic mutation across the data set. These include the mutation of genes involved in protein translation (seen in nearly half of the patients), genes involved in histone methylation, and genes involved in blood coagulation. In addition, a broader than anticipated role of NF-κB signalling was indicated by mutations in 11 members of the NF-κB pathway. Of potential immediate clinical relevance, activating mutations of the kinase BRAF were observed in 4% of patients, suggesting the evaluation of BRAF inhibitors in multiple myeloma clinical trials. These results indicate that cancer genome sequencing of large collections of samples will yield new insights into cancer not anticipated by existing knowledge. Multiple myeloma, a malignancy of plasma cells, remains incurable and is poorly understood. Chapman et al. have used next-generation sequencing to compare 38 multiple myeloma genomes with those of normal cells from the same patients. The disease involves mutations of genes with roles in protein translation, histone methylation and blood coagulation. In terms of clinically relevant findings, unexpected activating mutations were found in the kinase BRAF, inhibitors of which have recently shown dramatic clinical activity. This suggests that BRAF inhibitors should be evaluated in patients with BRAF-mutated multiple myeloma. Multiple myeloma, a malignancy of plasma cells, remains incurable and is poorly understood. Using next-generation sequencing of several multiple myeloma genomes reveals that this disease involves mutations of genes involved in protein translation, histone methylation and blood coagulation. The study suggests that BRAF inhibitors should be evaluated in multiple myeloma clinical trials.

Taq DNA polymerase can catalyze non-templated addition of a nucleotide (principally adenosine) to the 3' end of PCR-amplified products. Recently, we showed that this activity, which is primer-specific, presents a potential source of error in genotyping studies based on the use of short tandem repeat (STR) markers. Furthermore, in reviewing our data, we found that non-templated nucleotide addition adjacent to a 3' terminal C is favored and that addition adjacent to a 3' terminal A is not. It was clear, however, that features of the template in addition to the 3' terminal base also affect the fraction of product adenylated. To define consensus sequences that promote or inhibit product adenylation, we transplanted sequences between the 5' ends of the reverse primers of markers that are adenylated and those of markers that are not adenylated. It proved difficult to identify a single sequence capable of protecting the products of all markers from non-templated addition of nucleotide. On the other hand, placing the sequence GTTTCTT on the 5' end of reverse primers resulted in nearly 100% adenylation of the 3' end of the forward strand. This modification or related ones (called "PIG-tailing") should facilitate accurate genotyping and efficient T/A cloning.