Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43146 (tumour suppressor)
 5,935 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a new strategy for tumour suppressor gene isolation based on subtractive hybridization and the subsequent selection of transforming 'genetic suppressor elements', we have cloned a novel gene called ING1 encoding a 33-kD protein (p33ING1) that displays characteristics of a tumour suppressor. Acute expression of transfected constructs encoding this gene inhibited cell growth while chronic expression of ING1 antisense constructs promoted cell transformation. Limited analyses of tumour cell lines show that mutation of the ING1 gene occurs in neuroblastoma cells and reduced expression was seen in some breast cancer cell lines. These results demonstrate that ING1 can act as a potent growth regulator in normal and in established cells and provide evidence for a role as a candidate tumour suppressor gene whose inactivation may contribute to the development of cancers.
 ...
PMID:Suppression of the novel growth inhibitor p33ING1 promotes neoplastic transformation. 894 21

Down regulation of the ING1 candidate tumour suppressor promotes growth in soft agar and focus formation in vitro and tumour formation in vivo. ING1 encodes a nuclear, cell cycle-regulated protein, overexpression of which efficiently blocks cell growth and is capable of inducing apoptosis in different experimental systems. Here we present the first report of ING1 mutation and expression analysis in a total of 452 cancer samples. One germline missense alteration and three germline silent alterations were detected in 377 primary breast cancers while marked (2 - 10-fold) decreases in ING1 mRNA expression were seen in 44% of primary breast cancers and in ten of ten breast cancer cell lines examined. Furthermore, the majority of breast cancers (58%) showing decreased ING1 expression had metastasized to regional lymph nodes whereas only 9% of cancers with elevated ING1 expression, compared to adjacent normal tissues, were metastatic. Thus, ING1 mutation is very rare in breast or ovarian cancers, however, repression of ING1 expression frequently accompanies tumour development of breast cancer.
 ...
PMID:Suppression of ING1 expression in sporadic breast cancer. 1049 68

ING1 plays a critical role in regulating cell cycle progression and susceptibility to apoptosis. The present study aimed to investigate allelic deletion of, and mutations within, the ING1 gene in colorectal carcinomas. Genomic DNA was extracted from 29 sporadic colorectal carcinomas and samples of adjacent normal mucosa. Losses of heterozygosity of two polymorphic dinucleotide repeat markers close to the ING1 locus at chromosome 13q32-34 were analysed. Single-stranded conformational polymorphisms of polymerase chain reaction amplified regions within the coding sequence of ING1 were examined. Microsatellite instability was noted in 5 (17%) colorectal carcinomas; this confirms selection of a subject sample representative of the population. Neither losses of heterozygosity nor changes in electrophoretic mobility of single-stranded polymerase chain reaction products were detected in any colorectal carcinoma. Thus, in common with tumour suppressor genes such as RB and BRCA2 on chromosome 13q, ING1 appears to be retained intact in colorectal carcinomas.
 ...
PMID:The candidate tumour suppressor gene, ING1, is retained in colorectal carcinomas. 1061 39

A recently cloned tumour suppressor candidate, p33ING1, has been shown in vitro to collaborate with p53 to execute growth arrest and apoptosis. However, it is unclear as to how the expression of ING1 is regulated in normal and stress conditions. Using a p53-knockout mouse model, we investigated if the expression of ING1 was dependent on p53. We found that there was no difference in ING1 mRNA and protein levels between p53+/+ and p53-/- murine organs. In addition, when normal human epithelial keratinocytes (NHEK) and a keratinocyte cell line, HaCaT, which lacks wild-type p53 function, were exposed to UVB irradiation, the expression levels of ING1 were elevated in both NHEK and HaCaT cells. It is interesting, however, that UVB irradiation did not induce ING1 expression in dermal fibroblasts isolated from p53+/+ and p53-/- mice. Based on our findings, we therefore conclude that the expression of ING1 is independent of p53 status. UV induction of ING1 in keratinocytes suggests that ING1 may play a role in cellular stress response and skin carcinogenesis.
 ...
PMID:Expression of the novel tumour suppressor p33(ING1)is independent of p53. 1107 55

Previous studies have shown that UV-induced binding of p21(WAF1) to PCNA through the PCNA-interacting protein (PIP) domain in p21(WAF1) promotes a switch from DNA replication to DNA repair by altering the PCNA protein complex. Here we show that the p33(ING1b) isoform of the ING1 candidate tumour suppressor contains a PIP domain. UV rapidly induces p33(ING1b) to bind PCNA competitively through this domain, a motif also found in DNA ligase, the DNA repair-associated FEN1 and XPG exo/endonucleases, and DNA methyltransferase. Interaction of p33(ING1b) with PCNA occurs between a significant proportion of ING1 and PCNA, increases more than tenfold in response to UV and is specifically inhibited by overexpression of p21(WAF1), but not by p16(MTS1), which has no PIP sequence. In contrast to wild-type p33(ING1b), ING1 PIP mutants that do not bind PCNA do not induce apoptosis, but protect cells from UV-induced apoptosis, suggesting a role for this PCNA-p33(ING1b) interaction in eliminating UV-damaged cells through programmed cell death. These data indicate that ING1 competitively binds PCNA through a site used by growth regulatory and DNA damage proteins, and may contribute to regulating the switch from DNA replication to DNA repair by altering the composition of the PCNA protein complex.
 ...
PMID:UV-induced binding of ING1 to PCNA regulates the induction of apoptosis. 1168 5

The tumour suppressor ING1 shares many biological functions with p53, such as cell cycle arrest, DNA repair, apoptosis, and chemosensitivity. Previous findings indicate that the isoform p24ING1 is capable of enhancing chemosensitivity in human fibroblasts. To investigate if the p33ING1 isoform is also involved in chemosensitivity, we overexpressed p33ING1 in melanoma cells and assessed for cell death after treatment with camptothecin. Results from the sulforhodamine B cell survival assay and flow cytometry analysis show no significant difference among cells transfected with vector, p33ING1, and antisense p33ING1. Furthermore, co-transfection of the p33ING1 and p53 constructs had no effect on the frequency of cell death, indicating that there is no synergistic effect between the two tumour suppressors in camptothecin-induced cell death in melanoma cells. This is in contrast to previously observed collaboration between p33ING1 and p53 in DNA repair and apoptosis. Taken together, we demonstrate that p33ING1 does not enhance camptothecin-induced cell death in melanoma cells.
 ...
PMID:The tumour suppressor p33ING1 does not enhance camptothecin-induced cell death in melanoma cells. 1201 16

The tumour suppressor ING1 shares many biological functions with p53, such as cell cycle arrest, DNA repair, apoptosis, and chemosensitivity. Since p53 inhibits invasion and angiogenesis of melanoma cells, we sought to investigate if p33ING1 (one of ING1 isoforms) is also involved in these biological processes. We first overexpressed p33ING1 in melanoma cells and assessed the protein levels in MMP-1, MMP-2, and MMP-9. Results from Western blot analysis showed no significant difference in these matrix metalloproteinase levels between cells transfected with vector, p33ING1, and antisense p33ING1. Wound healing assay was performed to examine if p33ING1 plays a role in migration and invasion. Results showed that there was no difference between vector, p33ING1, and antisense p33ING1 groups in melanoma cell migration across the wound. Western blot analysis also indicated that there is no difference in the levels of proteins which are directly involved in angiogenesis, such as VEGF, Flt-1, and Flk-1, between cells transfected with vector, p33ING1, and antisense p33ING1. Furthermore, functional studies indicated that cultured medium derived from p33ING1-transfected melanoma cells did not stimulate the growth of HUVEC cells, compared to controls, providing support to the lack of functional role of p33ING1 in angiogenesis. In conclusion, we demonstrate in vitro that p33ING1, unlike p53, does not play a role in angiogenesis and migration in melanoma cells.
 ...
PMID:The tumour suppressor p33ING1 does not regulate migration and angiogenesis in melanoma cells. 1242 89

The incidence of basal cell carcinoma is the highest among all human malignancies. Epidemiological evidence indicates that ultraviolet radiation is the primary environmental cause for the pathogenesis of basal cell carcinoma. However, the genetic changes caused by ultraviolet radiation that lead to basal cell carcinoma formation remain unclear. We and others have demonstrated that the ING1 (inhibitor of growth 1) tumour suppressor plays an important role in cellular stress response to ultraviolet irradiation, such as DNA repair and apoptosis. This study was designed to investigate whether ING1 is overexpressed and/or mutated in human basal cell carcinoma. Immunohistochemistry, single-strand conformation polymorphism, and DNA sequencing were used to determine the expression and mutational status of the ING1 gene in 54 basal cell carcinoma biopsies. Immunohistochemical staining demonstrated that ING1 is overexpressed in 25% (6/24) human basal cell carcinomas. Single-strand conformation polymorphism and DNA sequencing revealed that only 1 in 54 (1.8%) basal cell carcinoma primaries contained a missense mutation in the ING1 gene. The mutation is located in exon 2 and could thus potentially interfere with the structure of every ING1 isoforms and the functions of the PHD zinc finger motif. Our data indicate that overexpression and mutation of the ING1 gene are infrequent in human basal cell carcinoma.
 ...
PMID:Analyses of the tumour suppressor ING1 expression and gene mutation in human basal cell carcinoma. 1263 89

The inhibitor of growth (ING) genes (ING1-4) probably descend from tumour suppressor genes. ING1 was the first to be identified and later isolated using an approach to detect genes whose expression is suppressed in cancer. The others were isolated through homology and similarity searches in human and mouse databases. All members contain a plant homeodomain involved in macromolecule recognition. Apart from the extensively studied ING1, little is known about the number of transcripts encoded by the other members or their gene structure. ING1 encodes several differentially spliced mRNAs, which may produce a family of proteins. The most widely expressed protein isoform is p33(INGb1), which is involved in restriction of cell growth and proliferation, apoptosis, tumour anchorage independent growth, cellular senescence, maintenance of genomic stability, and modulation of cell cycle checkpoints. ING1 gene mutation is uncommon in cancer, although the subcellular localisation of p33(INGb1) may have an effect on its function. The p33(INGb1) cellular compartmental shift from the nucleus to the cytoplasm may cause loss of normal cellular function, and may play a central role in the pathogenesis of several cancers.
 ...
PMID:The role of the tumour suppressor p33 ING1b in human neoplasia. 1283 93

The ARF tumour suppressor protein plays a critical role in the activation of p53 in response to oncogenic stress. ARF can activate p53 through nucleolar sequestration of Mdm2. However, several lines of evidence indicate that this is not the only way of action of ARF, and alternative mechanisms must exist. p33ING1 is a putative tumour suppresor, which induces cell-cycle arrest and apoptosis in a p53-dependent manner. Here, we describe that ARF and p33ING1 can interact in vivo. We also show that the subcellular localization of ING1 can be modulated by ARF protein levels, causing a displacement from nuclear to nucleolar localization. Finally, the ability of p33ING1 to cause cell-cycle arrest and induction of p21CIP1, or Mdm2, is impaired in ARF-deficient primary mouse fibroblasts. Based on these observations, we propose that the interaction with p33ING1 represents a novel mechanism for the tumour suppression function of ARF.
 ...
PMID:A functional link between the tumour suppressors ARF and p33ING1. 1660 80


1 2 Next >>