Expression of mRNA for GHRH (A) and GHRH-SV receptors (B) in DMS-153 SCLC tumors. Poly(A) RNAs from individual tumor samples were subjected to RT-PCR analysis, electrophoresed on agarose gel, and stained with ethidium bromide. (A) RT-PCR analysis shows a product of 322 bp for GHRH. (B) PCR products of 720 bp for SV1 and 566 bp for SV2 were detected. Lane M, 100-bp DNA molecular marker; lane 1, untreated tumor; lane 2, tumor treated with RC-3940-II; lane 3, tumor treated with JV-1-65; lane 4, tumor treated with RC-3940-II and JV-1-65; lane 5, tumor treated with JV-1-63; lane 6, positive control from LNCaP human prostate cancer cells; lane 7, negative control.