Osteopontin splice variant RNA in blood. Analysis of osteopontin splice variant mRNA (mean ± sem) in blood specimens from breast cancer (n = 67), lung cancer (n = 45), pancreatic cancer (n = 7), or gynecologic cancer (n = 6) patients and healthy controls (n = 74). Significance is accepted at the α = 0.05 level. A) Measurements of osteopontin-a by real-time RT-PCR in all blood samples. B) Osteopontin-b in various cancers versus healthy controls. C) Osteopontin-c in various cancers versus healthy controls. The insert shows the same graph with a logarithmic y-axis. D) Visualization of representative real-time RT-PCR products by agarose gel electrophoresis. To confirm the integrity of the PCR products, a representative cancer specimen was compared to a representative healthy control. The cell line MDA-MB-435 and no template (H2O) served as positive and negative controls respectively. a = ostepontin-a, b = ostepontin-b, c = ostepontin-c, ac = β-actin, m = markers.