p21 historically has been considered a tumor suppressor since first studies showed that p21-/-mice display spontaneous tumor formation after 16 months and additionally these mice are more sensitive to chemically induced carcinogenesis [1,2]. On the contrary, recently a potential function as an oncogene has been described for p21. For instance mice deficient for p53 spontaneously develop multipl...

PURPOSE p21 is a direct p53 response gene. Although several studies have correlated p21 and p53 expression, only one has evaluated p21 expression as a function of sequenced p53 gene mutation. We hypothesize that such an analysis may be useful in prognosticating outcome for individuals diagnosed with epithelial ovarian cancer. EXPERIMENTAL DESIGN DNA from the primary ovarian cancers of 267 pat...

Long intergenic non-coding RNA p21 (lincRNA-p21), known as the direct transcriptional target of p53, was found down-regulated in several human solid tumors. However, little is known about the role of lincRNA-p21 in gastric cancer. The expression levels of lincRNA-p21 in tissue samples and cell lines were detected by qRT-PCR. MGC-803 and MKN-45 cells were transfected with siRNAs targeting lincRN...

Tubulointerstitial renal injury induced by unilateral ureteric obstruction (UUO) is characterized by marked cell proliferation and apoptosis. Proliferation requires cell cycle transit that is positively regulated by cyclins and cyclin-dependent kinases (CDKs) and inhibited by the CIP/KIP family of cyclin-dependent kinase inhibitors (CKIs: p21, p27, and p57). We have shown that the absence of p2...

IFN-gamma-mediated growth inhibition requires signal transducers and activators of transcription (STAT)-1 activation and may require induction of the cyclin-dependent kinase inhibitor p21. Using an electrophoretic mobility shift assay, we identified STAT1 activation after IFN-gamma treatment in breast cancer cell lines. Accordingly, IFN-gamma inhibited proliferation of monolayer cultured MCF-7 ...

Non-small cell lung cancer (NSCLC) accounts for approximately 80-85% of all lung cancer cases. Cigarette smoking is the number one risk factor which is attributed to more than four out of five cases of lung cancers. The prognostic impact of cell cycle regulation-associated tumor suppressors including p53 and p21 for NSCLC is still controversial. In the present study, we examined p53 and p21 exp...

p21 protein (p21) inhibitor of cyclin-dependent kinases is a critical downstream effector in the p53-specific pathway of growth control and can also be induced by p53-independent pathways in relation to terminal differentiation. We investigated p21 immunoreactivity in 261 breast carcinomas (141 node negative and 120 node positive) with long-term follow-up (median, 73 months; range, 37-119). p21...

We previously reported that apicidin, a novel histone deacetylase inhibitor, inhibited the proliferation of tumor cells via induction of p21. In this study, we determined the molecular mechanisms by which apicidin induced the p21 gene expression in HeLa cells. Apicidin induced p21 mRNA independent of the de novo protein synthesis and activated the p21 promoter through Sp1–3 site located at 82 a...

During the pathogenesis of rheumatoid arthritis (RA), the synovial fibroblasts increase in number and produce proinflammatory cytokines and matrix metalloproteinases (MMPs) that function to promote inflammation and joint destruction. Recent investigations have suggested that cell cycle activity and inflammation may be linked. However, little is known about the mechanisms responsible for the coo...

P21WAF1/Cip1 (p21) translocates to the cytoplasm inducing cell cycle progression and survival upon Akt/PKB activation. We studied whether heregulin beta1 (HRGbeta1), that activates the PI3K/Akt and MAPK pathways, also misallocates p21. We also explored whether HRGbeta1 interferes with the effects of tamoxifen. The clinical material studied helped us to clarify whether p21 was associated with ph...