['Dermal papilla cells (DPCs) are specialized fibroblasts found in the hair follicle papilla, which are associated with the development and cycle regulation of hair follicles (HFs). DPCs exhibit a multilayer aggregative growth character, which is closely related to induction of HF formation. Versican, a large chondroitin sulphate proteoglycan and one of the major components of the extracellular matrix, is involved in the formation of HF.', 'To confirm the relationship between versican and the aggregative growth of DPCs, we first induced and established an aggregative cell model in DPCs in vitro, with cells taken to passage 8. Simultaneously, aggregative passage 2 DPCs and nonaggregative passage 8 DPCs were selected as parallel controls. RNA interference (RNAi) targeted to versican was used in passage 2 DPCs using a lentiviral vector. Reverse transcriptase (RT)-PCR and western blotting were used to assay the expression of versican in DPCs.', 'RNAi targeted to versican efficiently suppressed the aggregative growth of passage 2 DPCs, and the inhibitory effect was significant 3 days after RNAi treatment. The mRNA and protein levels of versican were also downregulated in passage 2 DPCs, and were lower than levels in nonaggregative passage 8 DPCs. Notably, the aggregative growth of nonaggregative passage 8 DPCs was restored after induction in a 1 : 1 v/v mixture of fresh DMEM and medium recycled from a previous passage.'] Does versican targeting by RNA interference suppress aggregative growth of dermal papilla cells?