Search results for "tumor suppressor gene"
showing 10 items of 98 documents
Prognostic relevance of CCN3 in Ewing sarcoma
2009
Ewing sarcoma is a highly aggressive malignant bone tumor occurring preferentially in children and young adults. At present, only clinical features, such as patient age, presence of clinically evident metastases at diagnosis, and poor response to neoadjuvant chemotherapy, are widely accepted as prognostic indicators in Ewing sarcoma. In this study, we assessed the prognostic value of CCN3 (Nov), a matricellular protein that play crucial roles in bone formation. Polyclonal antibodies directed against each of the different CCN3 modules were used to identify variant CCN3 proteins in tumors and to draw potential relationships between the expression of these variants and the outcome of patients …
Expression of the Tumor Suppressor Gene Product p16INK4 in Benign and Malignant Melanocytic Lesions
1998
The gene MTS1 encodes p16INK4, an inhibitor of cyclin-dependent kinase 4, and is frequently deleted, mutated, or silenced by promoter methylation in melanoma cells and in the germline of familial melanoma patients. Although MTS1 may thus be the candidate melanoma suppressor gene that maps to chromosome 9p21, it is not clear how dysfunction at that locus temporally relates to melanoma progression. To further test its role in sporadic melanoma, the expression of p16INK4-protein and -mRNA was characterized in melanomas and melanocytic nevi by immunocytochemistry and in situ reverse transcriptase-polymerase chain reaction. Histologic tissue sections were immunolabeled with anti-p16INK4 antibody…
Anaplastic Wilms' tumour, a subtype displaying poor prognosis, harbours p53 gene mutations
1994
The genetics of Wilms' tumour (WT), a paediatric malignancy of the kidney, is complex. Inactivation of the tumour suppressor gene, WT1, is associated with tumour aetiology in approximately 10-15% of WTs. Chromosome 17p changes have been noted in cytogenetic studies of WTs, prompting us to screen 140 WTs for p53 mutations. When histopathology reports were available, p53 mutations were present in eight of eleven anaplastic WTs, a tumour subtype associated with poor prognosis. Amplification of MDM2, a gene whose product binds and sequesters p53, was excluded. Our results indicate that p53 alterations provide a molecular marker for anaplastic WTs.
Effects of the MDM2 inhibitor Nutlin-3a on sensitivity of pancreatic cancer cells to berberine and modified berberines in the presence and absence of…
2021
Abstract Approaches to improve pancreatic cancer therapy are essential as this disease has a very bleak outcome. Approximately 80% of pancreatic cancers are pancreatic ductal adenocarcinomas (PDAC). A key regulatory gene frequently mutated (∼75%) in PDAC is the TP53 tumor suppressor gene which controls the transcription of multiple genes involved in cell cycle progression, apoptosis, cancer progression and other growth regulatory processes. The mouse double minute 2 homolog (MDM2) gene product is a nuclear-localized E3 ubiquitin ligase and negatively regulates the TP53 protein which results in its proteasomal degradation. Various MDM2 inhibitors have been isolated and examined in clinical t…
DNA ploidy and S-phase fraction, but not p53 or NM23-H1 expression, predict outcome in colorectal cancer patients. Result of a 5-year prospective stu…
2002
Purpose: The aim of this study was to determine TP53 and NM23-H1 immunoreactivity, DNA ploidy, and S-phase fraction (SPF) in a series of 160 patients undergoing resective surgery for primary operable colorectal cancer (CRC) and to establish whether these alterations have any clinical value in predicting CRC patients' prognosis. Methods: TP53 and NM23-H1 expressions were evaluated on paraffin-embedded tissue by immunohistochemistry and DNA-ploidy and SPF on frozen tissue by flow-cytometric analysis. Results: The median follow-up time in our study group was 71 months (range 34-115 months). P53 protein expression was associated with distal tumors (P < 0.05) and DNA aneuploid tumors (P < …
Prognostic role and implications of mutation status of tumor suppressor gene ARID1A in cancer: A systematic review and meta-analysis
2015
Loss of the tumor suppressor gene AT-rich interactive domain-containing protein 1A (ARID1A) has been demonstrated in several cancers, but its prognostic role is unknown. We aimed to investigate the risk associated with loss of ARID1A (ARID1A-) for all-cause mortality, cancer-specific mortality and recurrence of disease in subjects with cancer. PubMed and SCOPUS search from database inception until 01/31/2015 without language restriction was conducted, contacting authors for unpublished data. Eligible were prospective studies reporting data on prognostic parameters in subjects with cancer, comparing participants with presence of ARID1A (ARID1A+) vs. ARID1A-, assessed either via immunohistoch…
Htid-1, the human homolog of the Drosophila melanogaster l(2)tid tumor suppressor, defines a novel physiological role of APC.
2007
Htid-1, the human counterpart of the Drosophila tumor suppressor gene lethal(2)tumorous imaginal discs (l(2)tid) encodes three splice forms translated into three cytosolic - Tid50, Tid48 and Tid46 - and three mitochondrial - Tid43, Tid40 and Tid38 - proteins. Here we provide evidence for the association of the endogenous Tid50/Tid48 proteins with the adenomatous polyposis coli (APC) tumor suppressor in normal colon epithelium, colorectal cancer cells and mouse NIH3T3 fibroblasts. Using the Glutathione S-transferase binding assay we show that the N-terminal region including the Armadillo domain (ARM) of APC is sufficient to bind the Tid molecules. Using immunoprecipitation and confocal micro…
Absence of p53 gene mutations in hepatocarcinomas from a Mediterranean area of Spain
1999
The incidence of p53 gene abnormalities in human hepatocellular carcinoma (HCC) varies in different geographical areas, being higher in regions where hepatitis virus infection and dietary exposure to aflatoxin B1 are the most common aetiological agents. These mutations are less frequently encountered in Europe, although some studies have reported p53 protein overexpression in up to 45% of cases analysed. We have analysed 129 tumour samples of primary malignant hepatic neoplasms recovered from paraffin blocks processed in two pathology laboratories in a Mediterranean area of Spain (Valencia and Gerona). Among 14 cases in which p53 immunohistochemistry expression proved positive, 5 stained in…
Differential gene expression in p53-mediated G(1) arrest of human fibroblasts after gamma-irradiation or N-phosphoacetyl-L-aspartate treatment.
2000
In human fibroblasts, N:-phosphoacetyl-L-aspartate (PALA) and gamma-radiation induce reversible and irreversible p53-mediated G(1) cell cycle arrest, respectively. By coupling the premature chromosome condensation technique to fluorescence in situ hybridization, we found no evidence of DNA damage after PALA treatment. We used representational difference analysis (cDNA-RDA) to study changes in gene expression after PALA treatment and gamma-radiation in normal human fibroblasts. The mammary-derived growth inhibitor (MDGI) gene was expressed in PALA-treated cells. Ectopic MDGI expression arrested PALA-treated but not irradiated RKO cells. Expression of an antisense RNA against MDGI resulted in…
The human protein Hugl-1 substitutes for Drosophila lethal giant larvae tumour suppressor function in vivo
2004
Drosophila lethal giant larvae: (lgl), discs large (dlg) and scribble (scrib) are tumour suppressor genes acting in a common pathway, whose loss of function leads to disruption of cell polarity and tissue architecture, uncontrolled proliferation and growth of neoplastic lesions. Mammalian homologues of these genes are highly conserved and evidence is emerging concerning their role in cell proliferation control and tumorigenesis in humans. Here we investigate the functional conservation between Drosophila lethal giant larvae and its human homologue Hugl-1(Llgl1). We first show that Hugl-1 is lost in human solid malignancies, supporting its role as a tumour suppressor in humans. Hugl-1 expres…