Thus, in mouse tumors with high frequency of p53 LOH (osteosarcomas and fibrosarcomas), we find that mutant p53 protein is stabilized (16/17 cases, 94%) and tumor onset is significantly accelerated compared with p53+/- tumors (GOF).
This approach has facilitated the identification of novel AT-rich interaction domain 1A gene mutations in ovarian clear cell carcinoma, frequent tumor protein 53 (<i>TP53</i>) gene mutations in high-grade ovarian serous carcinoma, and Kirsten rat sarcoma and B-rapidly accelerated fibrosarcoma proto-oncogene, serine/threonine kinase gene mutations in low-grade ovarian serous carcinoma.
She presented with a clinical diagnosis of Li-Fraumeni-like syndrome (LFL), showing papillary thyroid carcinoma and fibrosarcoma of the left flank, and had no TP53 germline mutations.
The efficacy of spermine was investigated on induction of autophagy through histone deacetylation and p53 activation in human fibrosarcoma cell line, HT1080.
In addition, the expression level of COX-2 was also increased by PFT-α in normal fibroblasts as well as in HT1080 fibrosarcoma cells with p53 wild-type cells.
To learn more about its effect on cellular proliferation and chemoresistance independent of p53 up-regulation, human HT-1080 fibrosarcoma cells null for p14(ARF) and harboring a defective p53 pathway were stably transfected with p14(ARF) cDNA under the tight control of a doxycycline-inducible promoter.
To detect delayed activation of p53, we constructed a reporter plasmid containing the p53-responsible promoter and the bacterial beta-galactosidase (beta-gal) gene and introduced it into human fibrosarcoma (HT1080) cells, which retain wild-type p53 function.
Absence of p53 functional abnormalities excluded relationships between CCSK and CMN as in AWT, supporting the association of cellular CMN with congenital fibrosarcomas as more recently proposed.
There was an increasing trend in the proportion of abnormal expression of Ki-67, Bcl-2, pRB, and p53 with the increase of tumor aggressiveness from desmoid tumors to LG-FS to HG-FS.
Permanent overexpression of the hRAD17 gene in human fibrosarcoma cells resulted in p53 activation and a significant reduction of S- and G2/M-phase cells accompanied by an accumulation of the G1-phase population, suggesting that hRAD17 may have a role in cell cycle checkpoint control.
According to our results, p53 protein nuclear expression was detected in 20% (8/40) of the tumours (1 fibrosarcoma, 2 liposarcomas, 1 leiomyosarcoma, 1 rhabdomyosarcoma, 2 Ewing's sarcomas and 1 unclassified sarcoma).
We show that p53 acts as potent tumor-suppressor gene independent of its well-documented effects on tumor-cell proliferation and apoptosis. p53 activates target genes in a murine fibrosarcoma cell-line but does not affect tumor cell-cycle progression or survival.
The studies reported here assess whether p53 deficiency leads to spontaneous genetic instability by comparing cell cycle responses and amplification frequencies of the human fibrosarcoma cell line HT1080 when treated with PALA or with methotrexate, an antifolate that, under the conditions used, should not generate DNA breaks. p53-deficient HT1080 cells generated PALA-resistant variants containing amplified CAD genes at a frequency of >10(-5).
Investigation of p53 mutational status revealed 6 mutations in myogenic sarcomas but none in malignant neural tumors or fibrosarcomas, suggesting different roles of p53 in the 3 STS groups.
In the present study, the wild type p53 protein in human fibrosarcoma HT1080 cells were targeted with HPV-18 E6 and the viability of these cells in response to treatment with adriamycin, u.v.-irradiation and gamma-irradiation was examined.
The p53 protein is highly expressed in fibrosarcoma derived from Rat-1 cells transfected with cigarette smoke condensate-treated human fetal lung DNA but expressed low in the counterparts of nitroso-N-methylurea and dimethyl sulfoxide groups.
In this study we analysed by immunohistochemistry the expression of p53 protein in 14 malignant fibrous histocytomas (MFHs), 22 other types of sarcoma (eight leiomyosarcomas, four rhabdomyosarcomas, four liposarcomas, two fibrosarcomas, two chondrosarcomas, one malignant schwannoma, and one dermatofibrosarcoma protuberans), and 25 non-malignant mesenchymal lesions (eight dermatofibromas, four cases of nodular fasciitis, three leiomyomas, three fibromatoses, two epithelioid.leiomyomas, two neurofibromas, one schwannoma, one myositis ossificans, and one giant cell tumour of tendon sheath).