The mechanism of placental alkaline phosphatase induction in vitro

Abstract

The mechanism of placental alkaline phosphatase (PLAP) induction by prednisolone in a uterine cervical epidermoid cancer cell line SKG-IIIa was investigated in vitro by enzyme-cytochemistry, enzyme immunoassay, Northern and Southern blot analysis, and in situ hybridization. Enzyme-cytochemical alkaline phosphatase (ALP) staining and immunoassay revealed increased levels of PLAP (heat-stable ALP) in prednisolone-treated cells. Northern blot analysis and in situ hybridization showed increased amounts of PLAP mRNA. Southern blot analysis indicated that PLAP was not a product of an amplified or rearranged gene. These findings suggest that the induction of PLAP mRNA in SKG-IIIa cells by prednisolone in turn increased the levels of PLAP.

Use of nucleotides as an alternative to formamide in non-radioactive in situ hybridization.

“…Recently we have developed a new method (10, 11, 17) using thymine-thymine (T-T) dimerized DNA as a nonradioactive probe, which is thought to be the simplest in terms of no requirements for the separation of labeled DNA from unreacted labeling compounds, and we have further shown a wide applicability of the method (7,8,9,18,21). In parallel with the approach, using T-T dimerized DNA probes we have tried to establish a tissue processing procedure best suited to non-radioactive in situ hybridization (10, 16).…”