The aryl hydrocarbon receptor (AHR) is a basic helix-loop-helix (bHLH) transcription factor that is activated by environmental contaminants including polychlorinated biphenyls (PCBs). The AHR affects a variety of processes that are involved in cell growth and differentiation. In this study, we constructed a P19 embryonic carcinoma cell line with A...

This study demonstrated, for the first time, the following events related to p19(ARF) involvement in mammary gland development: 1) Progesterone appears to regulate p19(ARF) in normal mammary gland during pregnancy. 2) p19(ARF) expression levels increased sixfold during pregnancy, and the protein level plateaus during lactation. 3) During involution, p19(ARF) protein level remained at high level...

The CDKN2A/ARF locus encompasses overlapping tumor suppressor genes p16(INK4A) and p14(ARF), which are frequently co-deleted in human malignant mesothelioma (MM). The importance of p16(INK4A) loss in human cancer is well established, but the relative significance of p14(ARF) loss has been debated. The tumor predisposition of mice singly deficient for either Ink4a or Arf, due to targeting of exo...

RNA interference (RNAi) is the biological mechanism that allows targeted gene knockdown through the addition of exogenous short-interfering RNAs (siRNAs) to cells and organisms. RNAi has revolutionized cell biology and holds enormous potential for human therapy. One of the major challenges facing RNAi as a therapy is achieving efficient and nontoxic delivery of siRNAs into the cell cytoplasm, s...

Considerable effort has been made to elucidate the mechanism of Lyme arthritis. We focused on p19, a cell cycle-regulating molecule, because it is known to inhibit cell cycle division of T lymphocytes which may be responsible for the induction of arthritis. We show that anti-p19 antibody treatment enhances the inflammatory response normally detected at the tibiotarsal joints of Borrelia burgdor...

Sera of individuals infected with adult T-cell leukaemia virus (ATLV) react predominantly with the polypeptides gp68, p24 and p19. These polypeptides were isolated from ATLV-infected MT-2 cells and virus. The radioiodinated polypeptides were used to quantify respective antibodies in individual ATLV carrier sera. Heteroantisera prepared in rabbits against isolated polypeptides facilitated studie...

Transcriptome profiling facilitates the identification of developmentally regulated genes. To quantify the functionally active genome of P19 embryonic carcinoma (EC) cells induced to form cardiomyocytes, we employed serial analysis of gene expression (SAGE) to sequence and compare a total of 171,735 SAGE tags from three libraries (undifferentiated P19 EC cells, differentiation days 3 + 0.5 and ...

Ectopic expression of oncogenes such as Ras induces expression of p19(Arf), which, in turn, activates p53 and growth arrest. Here, we used a multistage model of squamous cell carcinoma development to investigate the functional interactions between Ras, p19(Arf), and p53 during tumor progression in the mouse. Skin tumors were induced in wild-type, p19(Arf)-deficient, and p53-deficient mice using...