Figure 3. Both type 1 and type 2 5-reductase isozymes were expressed in LNCaP cells as demonstrated by reverse transcriptase-polymerase chain reaction (RT-PCR). Analysis of 5-reductase-1 (5RD1, top panel) and 5-reductase-2 (5RD2) messenger RNA (middle panel) by RT-PCR or RTPCR Southern blot hybridization (bottom panel) was performed as described in the "Materials and Methods" section. Two micrograms of total cellular RNA, or tRNA, or 2 or 10 pg of 5-reductase-2 sense transcript were used in a 50-µL RT-PCR reaction. An aliquot of RT-PCR samples was electrophoresed in a 2% agarose gel, visualized by ethidium bromide staining, or transferred to nitrocellulose for Southern blot hybridization with a specific human 5-reductase-2 riboprobe. Lanes labeled with L1 through L4 are different RNA samples from LNCaP cells; lanes with O, ovary RNA samples; T, testis RNA sample, S2 and S10, 5-reductase-2 sense transcript, 2 and 10 pg, respectively; lanes with -, no RNA; and M, DNA size markers as marked on the side in base pairs. The specific products of 18s, 5-reductase-1, and 5-reductase-2 are indicated by an arrow or an arrowhead, respectively.