Function for p300 and not CBP in the apoptotic response to DNA damage.

The cellular response to ionizing radiation (IR) includes the induction of apoptosis. The p300/CBP proteins possess histone acetyltransferase activity and function as transcriptional coactivators of p53. We have prepared cells deficient in p300 or CBP to define the roles of these proteins in the cellular response to DNA damage. The present results demonstrate that p300, but not CBP, contributes to IR sensitivity of cells. The results also demonstrate that IR-induced apoptosis is impaired in the p300-, but not CBP-, deficient cells. These findings indicate that p300 functions in the apoptotic response to DNA damage.

Unscheduled expression of cyclins by anti-cancer drug exposure.

The scheduled expressions of cyclins are observed in the normal cells or the tumor cells whose phenotype is characterized by scheduled expression of cyclins, while unscheduled expression of cyclins were reported in several leukemic and solid tumor cell lines by anti-cancer drugs. We studied the effects of cytotoxic concentrations of Taxol (TXL) on cyclin D1 and B1 expression on human ovarian cancer cell lines. In KFr13 cells, the control group showed low degree of cyclin D1 and moderate degree of cyclin B1 expression in all cell cycles, while 1 microM TXL exposure resulted remarkable cyclin D1 and B1 expression in G2+M phase cells. OVCAR-3 cells showed relatively high degree of cyclin D1 expression and mild to moderate degrees of cyclin B1 expression in control group. 1 microM TXL showed no significant changes in cyclin D1 expression, while decreased expression cyclin B1 in G0+1 and S and moderate degree of expression in G2+M.

Malignant fibrous histiocytoma of the vagina.

We describe here the case of an 82-year-old woman presenting with a hemorrhagic tumor on the anterior vaginal wall. She was diagnosed with malignant fibrous histiocytoma (MFH) from the findings of cytological analysis of biopsied surface tissue, histopathologic analysis of biopsied tissue, immunohistochemical staining, and electron microscopy. Cytological analysis of the biopsy sample harvested from the tumor surface showed multinucleated giant cells and large atypical cells with rough, granular, chromatin, as well as notable nucleoli. A storiform pattern was observed histopathologically, and immunohistochemical staining confirmed positive reactions to alpha 1-antichymotripsin (alpha 1-ACT), vimentin, and lysosome, but negative reactions to epithelial membrane antigen (EMA), cytokeratin, and alpha-smooth muscle action (alpha-SMA). Electron microscopy showed histiocyte-derived cells with a segmented nucleus with a large groove, pseudopodic cytoplasmic projections, and lysosome-like structures. However, intercellular adhesion factors were not notable, and microvilli were absent. Based on the above findings, a diagnosis of MFH originating from the vaginal wall was made. Because of the patient's advanced age, and, in accordance with her wishes, three courses of cancer chemotherapy, consisting of doxorubicin hydrochloride, fluorouracil, and cisplatin were carried out, without surgery. No reduction in the size of the tumor was seen at follow up, and despite the absence of metastasis and no exacerbation of her general condition, she died suddenly at home 2 years after being discharged.

The application of magnetic cell sorter (MACS) to detect fetal cells in maternal peripheral blood.

OBJECTIVES: The aim of the present study was to investigate the effectiveness of sorting fetal nucleated red blood cells (FNRBC) from maternal peripheral blood, particularly during early gestation periods, by a combination of specific gravity centrifugation and magnetic cell sorter (MACS). METHODS: Without prior knowledge of the gender of the fetus, we determined gender by analyzing a Y-chromosome specific sequence by nested-PCR, using 10 ml of the peripheral blood of healthy primigravida women at different stages of gestation (first trimester: n = 17, second trimester: n = 13, and third trimester: n = 19). The results of this prenatal sex determination were compared to the sex of newborns. RESULTS: The specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) of the present method during the first trimester were 100, 81.8, 100, and 75%, respectively; during the second trimester, 80, 50, 80, and 50%, respectively; and during the third trimester, 25, 63.6, 53.8, and 33.3%, respectively. CONCLUSION: The results show that this prenatal sex determination method has a highly accurate diagnostic rate during the first trimester, suggesting that it could be developed as a practical, non-invasive prenatal diagnostic technique for use during early gestation periods.

Role for p300 in stabilization of p53 in the response to DNA damage.

The nuclear p300/CBP proteins function as coactivators of gene transcription. Here, using cells deficient in p300 or CBP, we show that p300, and not CBP, is essential for ionizing radiation-induced accumulation of the p53 tumor suppressor and thereby p53-mediated growth arrest. The results demonstrate that deficiency of p300 results in increased degradation of p53. Our findings suggest that p300 contributes to the stabilization and transactivation function of p53 in the cellular response to DNA damage.