Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report the clinicopathologic findings of four cases of liposarcoma with meningothelial-like whorls. Two cases occurred in the retroperitoneum and the remaining cases in the anterior mediastinum and scrotum. The whorls varied in terms of amount and morphology and the type tissue surrounding the whorls also varied in every case. One of the retroperitoneal cases with large areas of whorl coalescence recurred in the abdominal wall as an inflammatory malignant fibrous histiocytoma one year after primary resection of the tumor, and a metastasis to the cervical spines was detected twenty months later. The other retroperitoneal tumor recurred locally two years after the resection of the tumor and the amount and cellularity of the whorls as well as p53 reactivity and Ki-67 labeling index were higher in the recurrent tumor. However, coalescence of the whorls was not present in the recurrent tumor in contrast to the primary tumor. The anterior mediastinal and scrotal cases have demonstrated neither local recurrence nor distant metastasis although the follow-up period has been less than one year. The cells comprising whorls showed positive reactions for CD10, CD56, CD99, factor XIII, and low-affinity nerve growth factor receptor in addition to vimentin and alpha-smooth muscle actin. Our results indicate that liposarcoma with meningothelial-like whorls is a heterogeneous group that shows wide variations in histologic findings and biologic behavior. The phenotypic transformation of the whorls to higher grade in two retroperitoneal tumors, which showed recurrence within two years of follow up, supports that a whorl is a sign of dedifferentiation. Although we demonstrate the expressions of several markers, such as CD10, CD56, CD99, factor XIII, and low-affinity nerve growth factor receptor, in the spindle cells of the whorls for the first time, the lineage of the whorls still cannot be addressed due to the fact that these markers are lineage nonspecific.
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PMID:Liposarcoma with meningothelial-like whorls. Report of four cases showing diverse histologic findings and behavior. 1283 76

We identified a missense germline mutation (Gly245Ser) in one of the mutation hot spots of the TP53 gene in two affected members of a Li-Fraumeni syndrome family. We also analyzed their tumors, a liposarcoma and a colorectal carcinoma. Both tumors exhibited p53 protein accumulation but none of them showed loss of the wild-type allele of the TP53 gene. We reviewed all published cases of tumors in germline TP53 mutation carriers where loss of heterozygosity data were available and identified 84 tumors with loss of the wild-type allele, 57 tumors with retention of heterozygosity, and 9 tumors with loss of the allele harboring the germline mutation. Among the tumors showing p53 accumulation, we observed a significant difference in the fraction of tumors showing p53 protein accumulation between the tumors with loss of the wild-type allele and those with retention of TP53 heterozygosity. This supports the idea that the pathogenesis of tumors in germline TP53 mutation carriers does not have to be associated with loss of the wild-type TP53 allele. The product of the normal allele can potentially be inactivated by a variety of other mechanisms or, as suggested by the analysis, many of these tumors may even preserve the activity of the wild-type p53 protein.
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PMID:A Li-Fraumeni syndrome family with retained heterozygosity for a germline TP53 mutation in two tumors. 1288 64

Like malignant fibrous histiocytoma (MFH), dedifferentiated liposarcoma represents a distinct subtype of liposarcoma and is characterized by an abrupt transition from well-differentiated liposarcoma (WDL) to highgrade dedifferentiated liposarcoma (DDL) . In addition, specific cytogenetic aberrations support the close biological relationship between WDL and DDL. Recent observations indicated the significance of cell cycle aberrations in tumor progression from the low-malignant, well differentiated to its dedifferentiated form, the prognosis of which is poor. Thus, alterations of mdm2 and p53 genes belong to the most frequently reported alterations in these two subtypes of liposarcoma. In previous investigations, we reported that loss of heterozygosity at the Rb gene locus, telomerase activity, hTERT, and c-Myc expression were associated with tumor progression in liposarcomas. In this study, we report on a case of a WD/DDL, in which both tumor components were separated using laser microdissection (P.A.L.M.) for the investigation of hTERT mRNA expression on a LightCycler. Macroscopically selected and histologically proven cryosections of low malignant and highly malignant tumor areas were cytogenetically investigated to confirm the diagnosis and to find additional chromosomal alterations with tumor progression.
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PMID:Different mRNA expression profile during tumor progression in a well-differentiated liposarcoma--A microdissection approach. 1292 48

The objective of this study was to review the clinicopathological features of seven patients presenting with well-differentiated liposarcoma (WDL), which was associated with subcutaneous lipoma. From 1980 through 2002, 34 individuals displaying WDL were treated in our institutions. Lipoma was observed in seven of these 34 patients (five men and two women, mean age of 66.7 years). The rate of co-existence of lipoma in WDL [20.6% (7/34)] cases was significantly higher than the corresponding rate in the other liposarcoma subtypes [2.5% (1/40)]. Immunohistochemically, cdk4 was positive in all WDLs (100%). ki-67 was positive in 57.1% (4/7) and mdm2 and p53 were positive in 14.5% (1/7) of the WDL cases. Weak cdk4 immunoreactivity was detected in two lipomas. All lipomas were negative for mdm2, p53 and ki-67. Comparison of the expression profile in these malignant and benign tumors, which had arisen in identical genetic backgrounds, confirmed the involvement of these proteins, especially cdk4, in the tumorigenesis process of WDL.
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PMID:Well-differentiated liposarcoma associated with benign lipoma. 1515 19

This report describes a 49-year-old woman with a well-circumscribed nodule of liposarcoma. The patient noticed a soft, slowly growing mass at the right sural region. Both axial computed tomography and magnetic resonance imaging revealed a soft tissue tumor consisting of nonfatty lesion measuring 5 x 3 x 3 cm circumscribed by a 1-cm thickened fatty area. Histologically, the tumor was made of 2 distinct components: the inner component of the tumor was a classic myxoid liposarcoma with numerous lipoblasts; the outer component was a lipoma-like lesion consisting of mature adipocytes without atypical nuclei. Immunohistochemically, MDM2 overexpression was observed and p53 immunophenotype was negative in both components. Molecular analysis revealed that type 1 TLS/ CHOP fusion gene transcript, characteristic of myxoid/round cell liposarcoma, was detected in both areas.
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PMID:Myxoid liposarcoma with adipocytic maturation: detection of TLS/CHOP fusion gene transcript. 1516 10

ONYX-015 is a provisionally replication competent adenovirus with oncolytic activity in cells with malfunctioning p53. Sarcomas represent a rational target for this approach given the high frequency of p53 mutations (40-75%) and MDM-2 amplification (10-30%). We, therefore, undertook a phase I/II study of ONYX-015, days 1-5 every month administered intratumorally under radiographic guidance, in combination with MAP (mitomycin-C, doxorubicin, cisplatin) chemotherapy in patients with advanced sarcoma. Six patients were treated. Injected lesions included liver metastases in four patients and chest wall metastases in two patients. Sarcoma histologies were gastrointestinal stromal tumors (GIST, two patients), leiomyosarcoma (two patients), liposarcoma (one patient), and malignant peripheral nerve sheath tumor (1 patient). Dose escalation was performed from 10(9) plaque forming units (PFU)/dose (total dose of 5 x 10(9) PFU/cycle) to 10(10) PFU/dose (total dose of 5 x 10(10) PFU/cycle) without dose-limiting toxicity being encountered. Immunohistochemistry of the metastatic lesions prior to treatment showed that five out of six patients were positive for p53, while two patients also had mdm-2 overexpression. Adenoviral replication was detected in two out of six patient biopsies on day 5 of the first cycle, by in situ hybridization (ISH). Both patients were treated at the highest dose level. ONYX-015 viral DNA was detected by quantitative PCR in the plasma of 5/6 patients on day 5 of the first cycle, and up to day 12 (7 days after the last viral dose) in one patient who had extended sampling for viral kinetics performed, suggesting viral replication in sarcoma tissue. One patient with p53 mutation and MDM-2 amplification achieved a partial response to treatment that lasted 11 months. In conclusion, intratumoral administration of ONYX-015 in combination with MAP chemotherapy is well tolerated with no significant toxicity due to ONYX-015 being encountered. Detection of viral DNA in post treatment tumor specimens by ISH and detection of the ONYX-015 genome in the peripheral blood by quantitative PCR, up to 7 days after the last viral dose provide evidence for adenoviral replication. There was evidence of antitumor activity in one out of six patients. Further investigation of this approach in patients with recurrent sarcomas is warranted.
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PMID:Phase I-II trial of ONYX-015 in combination with MAP chemotherapy in patients with advanced sarcomas. 1564 67

In myxoid/round cell liposarcoma (MLS/RCLS), the presence of a round cell (RC) component has been reported to correlate with a worse prognosis for the patients. However, little is known about the molecular genetic differences between conventional myxoid (MX) components and RC components in this tumour. The aim of this study was to investigate the possible implications of molecular alterations of G1 to S-phase check-point genes, especially in the RC component. We evaluated the immunohistochemical expression of p53, MDM2, p14 and p16 protein and assessed proliferative activities using MIB-1 in 29 RC components and 81 MX components from 90 cases. Mutation of the p53 gene, amplification of the MDM2 gene, homozygous deletion, methylation status and mutation of the p16(INK4a)/p14(ARF) genes were also investigated, using concordant paraffin-embedded and frozen material. The data were analysed together with clinicopathological factors to assess their prognostic implications in MLS/RCLS. Immunohistochemically, the over-expression of p53 protein (p = 0.01366) and the reduced expression of p14 (p < 0.0001) and p16 (p < 0.0001) proteins were significantly more frequently observed in RC components than in MX components. Reduced expression of p14 protein correlated significantly with hypermethylation of the p14(ARF) gene promoter (p = 0.0176) and over-expression of p53 protein (p = 0.00837). By univariate analysis, reduced expression of p14 and p53 missense mutation were found to reduce the rate of survival significantly (p < 0.05). Multivariate analysis, including clinicopathological factors, revealed that tumour site (p = 0.0251), the presence of an RC component (p = 0.0113), high MIB-1 labelling index (p = 0.0005) and p53 missense mutation (p = 0.0036) were adverse prognostic factors. In MLS/RCLS, reduction of p14 protein expression and p53 mutation were related to poor prognosis. Accordingly, the p14(ARF)/p53 pathway may contribute to the presence of an RC component and malignant progression in this tumour.
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PMID:Frequent alteration of p16(INK4a)/p14(ARF) and p53 pathways in the round cell component of myxoid/round cell liposarcoma: p53 gene alterations and reduced p14(ARF) expression both correlate with poor prognosis. 1662 96

Primary sarcomas of the breast are extremely rare with less than 1% of all malignant tumours of the breast reported in literature. At our Institution 1315 malignant tumours of the breast were diagnosed between 1999-2004; nine of them corresponded to primary sarcomas: angiosarcoma (3), leiomyosarcoma (1), low-grade fibromyxoid sarcoma (1), dematofibrosarcoma protuberans (1), liposarcoma (1), osteosarcoma (1), malignant peripheral nerve sheath tumour (1). Histopathological specimens stained with routine techniques and immunoperoxidase were reviewed; proliferation index and p53 over-expression were also determined. Patients' clinical reports were also reviewed to determine prognosis (favorable and unfavorable). The incidence observed (0.7%) is similar to those already published by others authors. Proliferation index was correlated with type of evolution, being an unfavourable prognosis factor when it was equal or major to 30%. Most of the tumours (67%) showed p53 (mayor or equal to 20% of nuclear staining) over-expression but this did not show a direct relationship with the evolution of each neoplasm.
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PMID:[Primary sarcomas of the breast]. 1671 62

The tumor suppressor protein p53 is a transcription factor that induces G(1) arrest of the cell cycle and/or apoptosis. The murine double-minute protein MDM2 and its homologue MDM4 (also known as MDMX) are critical regulators of p53. Altered transcripts of the human homologue of mdm2, MDM2, have been identified in human tumors, such as invasive carcinoma of the breast, lung carcinoma, and liposarcoma. MDM2 alternate forms act to negatively regulate the normal MDM2 gene product, thus activating p53. Although many reports have documented a plethora of tumor types characterized by MDM2 alternative transcripts, few have investigated the signals that might initiate alternative splicing. We have identified a novel role of these alternative MDM2 transcripts in the normal surveillance mechanism of the cell and in DNA damage response. We report that alternate forms of MDM2 are detected after UV irradiation. Furthermore, we show that mouse cells treated with UV are also characterized by alternative transcripts of mdm2, suggesting that this is an important and evolutionarily conserved mechanism for regulating the expression of MDM2/mdm2. An additional p53 regulator and mdm2 family member, MDM4, is likewise alternatively spliced following UV irradiation. By activating alternative splicing of both MDM2 and MDM4, yet another layer of p53 regulation is initiated by the cells in response to damage. A stepwise model for malignant conversion by which alternate forms of MDM2 and MDM4 place selective pressure on the cells to acquire additional alterations in the p53 pathway is herein proposed.
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PMID:Genotoxic stress induces coordinately regulated alternative splicing of the p53 modulators MDM2 and MDM4. 1701 6

MDM2 is a critical negative regulator of the p53 tumor suppressor protein. Recently, small-molecule antagonists of MDM2, the Nutlins, have been developed to inhibit the p53-MDM2 interaction and activate p53 signaling. However, half of human cancers have mutated p53 and they are resistant to Nutlin treatment. Here, we report that treatment of the p53-mutant malignant peripheral nerve sheath (MPNST) and p53-null HCT116 cells with cisplatin (Cis) and Nutlin-3a induced a degree of apoptosis that was significantly greater than either drug alone. Nutlin-3a also increased the cytotoxicity of both carboplatin and doxorubicin in a series of p53-mutant human tumor cell lines. In the human dedifferentiated liposarcoma cell line (LS141) and the p53 wild-type HCT116 cells, Nutlin-3a induced downregulation of E2F1 and this effect appeared to be proteasome dependent. In contrast, in MPNST and HCTp53-/- cells, Nutlin-3a inhibited the binding of E2F1 to MDM2 and induced transcriptional activation of free E2F1 in the presence of Cis-induced DNA damage. Downregulation of E2F1 by small interfering RNA significantly decreased the level of apoptosis induced by Cis and Nutlin-3a treatment. Moreover, expression of a dominant-negative form of E2F1 rescued cells from apoptosis, whereas cells overexpressing wild-type E2F1 showed an increase in cell death. This correlated with the induction of the proapoptotic proteins p73alpha and Noxa, which are both regulated by E2F1. These results indicate that antagonism of MDM2 by Nutlin-3a in cells with mutant p53 enhances chemosensitivity in an E2F1-dependent manner. Nutlin-3a therefore may provide a therapeutic benefit in tumors with mutant p53 provided it is combined with chemotherapy.
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PMID:Mouse double minute antagonist Nutlin-3a enhances chemotherapy-induced apoptosis in cancer cells with mutant p53 by activating E2F1. 1714 34


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