Origin of Merkel Cell Carcinomas No Longer Murky

Although Merkel cell carcinoma (MCC) is rare, it is highly malignant. Research into the etiologic basis of many other skin cancers has progressed significantly, but MCC causation remains obscure. The group that discovered the Kaposi sarcoma herpes virus has now cracked the MCC mystery, finding that 80% of MCCs harbor a novel polyomavirus (an icosahedral dsDNA virus that lacks a lipoprotein envelope). Because of its close association with MCC, the novel entity is designated Merkel cell virus (MCV).

Using a technique termed digital transcriptome subtraction, the investigators used high-throughput sequencing to identify foreign genetic sequences in MCC tumors. One such transcript revealed a foreign sequence that defined a new 5387-base-pair hum…