Expression of PTEN and Akt phosphorylation in lipopolysaccharide-treated NIH3T3 cells.

PTEN is a tumor suppressor gene encoding a phosphatase, and it negatively regulates cell survival mediated by the phosphoinositol 3-kinase (PI3-Kinase)-Akt pathway. To elucidate PTEN expression and its effect on the PI3-kinase-Akt pathway in fibroblasts and macrophages, we investigated the expression of PTEN and the phosphorylation status of Akt in NIH3T3 and RAW264.7 cells treated with LPS.

Transcription factor NF-Y regulates mdr1 expression through binding to inverted CCAAT sequence in drug-resistant human squamous carcinoma cells.

In this study, the expression and transcriptional regulation of the multidrug resistance-1 (MDR1) gene in multidrug-resistant SCCTF cells and -sensitive SCCKN cells derived from human squamous carcinoma were investigated. RT-PCR revealed that mdr1 mRNA was highly expressed in SCCTF cells while it was under the limit of detection in SCCKN cells. With an electrophoretic mobility shift assay using the mdr1 promoter region, a DNA-protein complex was detected strongly in SCCTF cells, but weakly in SCCKN cells.

Transblot and cytochemical identification of avidin-interacting proteins in mitochondria of cultured cells.

Cell lysates prepared from 3T3-L1 cells were analyzed by western blotting using the avidin-biotin complex system and anti-Bax antibody. The antibody interacted with bands of proteins with estimated molecular weights of 120, 74, 72, and 25 kDa. However, only the 25-kDa band was detected with the anti-Bax antibody when the direct immunoblotting method was used.