Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Array-based comparative genomic hybridization (array CGH) enables us to detect the genomic copy number alterations of cancers with high resolution. Our established array CGH platform consists of 2,304 BAC/PAC clones covering the whole genome at 1.3-mega base resolutions. Using this technique, we were thus able to reveal disease-specific genomic alterations and the candidate target genes in various lymphomas. We herein report the characteristic genomic alterations of malignant lymphomas including diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and adult T cell lymphoma/leukemia (ATLL). The combined use of the array CGH data with gene expression profiling and specific gene rearrangement analyses further delineated the subtype-specific genomic alterations. For instance, we revealed that activated B-cell-like DLBCL is characterized by a gain of chromosome 3, 18q and loss of 9 p21, whereas the germinal center B-cell-like DLBCL is characterized by a gain of 2p15, 7q, and 12q. Among these genomic alterations,we found the 9 p21 loss (p16INK4a locus) to be the most aggressive type of DLBCL. Comparisons of the genome profiles of FL,both with and without BCL2 rearrangement, also revealed the existence of a unique subgroup: trisomy 3 FL. Comparison of genome profiles between acute type and lymphoma types of adult T cell lymphoma also demonstrated that acute and lymphoma types are genomically distinct subtypes, and thus may develop tumors via distinct genetic pathways. In addition to identifying disease-specific genomic alterations, we also discovered several target genes of the genomic gains and losses. Furthermore,we developed a computer algorithm to classify lymphoma diseases or subtypes on the basis of copy number gains and losses. We applied the algorithm to the classifications of DLBCL and MCL diseases and ABC and GCB subtypes. The method correctly classified the DLBCL and MCL diseases at 89%, and ABC and GCB subtypes at 83%. These results demonstrate that copy number gains and losses detected by array CGH could be used for classifying lymphomas into biologically and clinically distinct diseases or subtypes. The genomic copy number alterations detected by array CGH are therefore considered to have the potential to help diagnose or classify different disease entities and tumor subtypes.
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PMID:[Analysis of genomic copy number alterations of malignant lymphomas and its application for diagnosis]. 1763 30

During the G1/S transition, p21 proteolysis is mediated by Skp2; however, p21 reaccumulates in G2 and is degraded again in prometaphase. How p21 degradation is controlled in mitosis remains unexplored. We found that Cdc20 (an activator of the ubiquitin ligase APC/C) binds p21 in cultured cells and identified a D box motif in p21 necessary for APC/C(Cdc20)-mediated ubiquitylation of p21. Overexpression of Cdc20 or Skp2 destabilized wild-type p21; however, only Skp2, but not Cdc20, was able to destabilize a p21(D box) mutant. Silencing of Cdc20 induced an accumulation of p21, increased the fraction of p21 bound to Cdk1, and inhibited Cdk1 activity in p21(+/+) prometaphase cells, but not in p21(-/-) cells. Thus, in prometaphase Cdc20 positively regulates Cdk1 by mediating the degradation of p21. We propose that the APC/C(Cdc20)-mediated degradation of p21 contributes to the full activation of Cdk1 necessary for mitotic events and prevents mitotic slippage during spindle checkpoint activation.
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PMID:APC/C(Cdc20) controls the ubiquitin-mediated degradation of p21 in prometaphase. 1767 94

Folate deficiency may affect gene expression by disrupting DNA methylation patterns or by inducing base substitution, DNA breaks, gene deletions and gene amplification. Changes in expression may explain the inverse relationship observed between folate status and risk of colorectal cancer. Three cell lines derived from the normal human colon, HCEC, NCM356 and NCM460, were grown for 32-34 days in media containing 25, 50, 75 or 150 nM folic acid, and the expression of genes involved in cell-cycle checkpoints, intracellular signaling, folate uptake and cell adhesion and migration was determined. Expression of Folate Receptor 1 was increased with decreasing media folate in all cell lines, as was p53, p21, p16 and beta-catenin. With decreasing folate, the expression of both E-cadherin and SMAD-4 was decreased in NCM356. APC was elevated in NCM356 but unchanged in the other lines. No changes in global methylation were detected. A significant increase in p53 exon 7-8 strand breaks was observed with decreasing folate in NCM460 cells. The changes observed are consistent with DNA damage-induced activation of cell-cycle checkpoints and cellular adaptation to folate depletion. Folate-depletion-induced changes in the Wnt/APC pathway as well as in genes involved in cell adhesion, migration and invasion may underlie observed relationships between folate status and cancer risk.
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PMID:Moderate folate depletion modulates the expression of selected genes involved in cell cycle, intracellular signaling and folate uptake in human colonic epithelial cell lines. 1768 72

Ensuring precise DNA replication and chromosome segregation is essential during cell division in order to provide genomic stability and avoid malignant growth. Proteolytic control of cell cycle regulators by the anaphase-promoting complex, activated by Cdh1 (APC(Cdh1)), is responsible for a stable G1 phase after mitotic exit allowing accurate preparation for DNA replication in the following S phase. APC(Cdh1) target proteins are frequently upregulated in tumor cells and the inactivation of human Cdh1 might interfere with genome integrity by target stabilization. Here we show that APC(Cdh1) is required for maintaining genomic integrity in primary human cells. Lentiviral-delivered strong and stable suppression of Cdh1 by RNA interference (RNAi) causes aberrant accumulation of several APC(Cdh1) target proteins, such as cyclin A, B, Aurora A or Plk1, which control accurate and equal distribution of the genetic information to daughter cells. This induces a premature and prolonged S phase, mitotic-entry delay and defects in chromosome separation and cytokinesis. Cell cycle deregulation by stable knockdown of Cdh1 leads to activation of p53/p21 and genomic instability, which is further increased by codepletion of p53. Thus, stabilization of APC(Cdh1) targets may initiate aberrant DNA replication and chromosome separation, and trigger a p53 response by deregulating G1 in primary human cells.
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PMID:The ubiquitin ligase APC(Cdh1) is required to maintain genome integrity in primary human cells. 1770 May 35

There is much evidence that dietary Ca(2+) loading reduces colon cell proliferation and carcinogenesis in humans and rodents, but during carcinogenesis it becomes ineffective or even tumor-promoting. We are beginning to see how Ca(2+) balances the continuous massive cell production in colon crypts by driving the terminal differentiation and eventually the apoptosis of the cells mainly on the mucosal surface, and how this Ca(2+) control is lost during colon carcinogenesis. The rapid proliferation of the transit-amplifying (TA) progeny of the colon stem cells is driven by the so-called "Wnt" signaling mechanism, which involves the stimulation of proliferogenic genes such as those for c-Myc and cyclin D1 and the silencing of the gene for the cell cycle-stopping p21(Cip1/WAF1) protein by nuclear beta-catenin*Tcf-4 complexes. TA cells avoid mitotic damage and premature apoptosis by expressing the protein survivin. It appears that TA cell cycling stops and terminal differentiation starts when the cells reach a higher level in the crypt where there is enough lumenal Ca(2+) to stimulate the expression and activation of CaSRs (Ca(2+)-sensing receptors), the signals from which stimulate the expression of E-cadherin. Along with this, the APC (adenomatous polyposis coli) protein appears and some of it enters the nucleus. There it makes the TA cells susceptible to the eventual apoptotic balancing by stopping survivin expression and the beta-catenin*Tcf-4 complex from driving further cell cycling by releasing beta-catenin from the nucleus, and delivering it to cytoplasmic APC*axin*GSK-3beta complexes for ultimate proteasomal destruction. Cytoplasmic beta-catenin is then prevented from returning to the nucleus by either being intercepted and destroyed by APC*axin*GSK-3beta complexes or locked by the emerging E-cadherin into membrane adherens junctions which tie the cell into the sheet of proliferatively shut-down cells with APC-dependent cytoskeletons moving to the mouth of the crypt and onto the flat mucosal surface. A common first step in sporadic colon carcinogenesis is the loss of functional APC which disorients upwardly directed migration and causes the retention of nuclear beta-catenin and proliferogenic beta-catenin*Tcf-4 complexes as well as genomic instability. Eventually the balance between cell proliferation and terminal differentiation and death is radically tipped in favour of proliferation by the appearance of apoptosis-resistant, survivin-expressing clones of Ca(2+)-insensitive cells which are locked into the proliferative, mutation-prone mode because of CaSR-disabling gene mutations which prevent the stimulation of E-cadherin expression and terminal differentiation.
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PMID:Calcium, calcium-sensing receptor and colon cancer. 1872 75

TGFbeta exerts a potent tumor-suppressive effect in the human colon carcinoma CBS and Moser cells. However, TGFbeta can also function as a tumor promoter. The mechanisms underlying the tumor promoting effect of TGFbeta are not understood. Both the CBS and Moser cells were found to express mutant (truncated) APC. Expression of this form of APC did not interfere with the tumor-suppressive function of TGFbeta. However, when APC expression was knocked down in these cells, TGFbeta function switched from that of tumor suppression to that of tumor promotion. TGFbeta stimulated cellular invasion and anchorage-independent growth in APC knocked-down cells. Knocking down APC expression abrogated the ability of TGFbeta to induce the expression of the tumor suppressor E-cadherin and the cyclin dependent kinase inhibitor p21/Waf1. TGFbeta now stimulated the constitutive TCF transcriptional activation activity associated with the beta-catenin/Wnt pathway in the APC knocked-down cells. Thus, the level of APC expression determined the type of TGFbeta function in these human colon carcinoma cells.
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PMID:Switch of transforming growth factor beta function from tumor suppression to stimulation in adenomatous polyposis coli (APC) knocked-down human colon carcinoma cells. 1877 39

p53 mutations occur in a large number of human malignancies. Mutant p53 is unable to affect downstream genes necessary for DNA repair, cell cycle regulation, and apoptosis. The styrylquinazoline CP-31398 can rescue destabilized mutant p53 expression and promote activity of wild-type p53. The present study examines chemopreventive effects of CP-31398 on intestinal adenoma development in an animal model of familial adenomatous polyposis. Effects were examined at both early and late stages of adenoma formation. Effects of CP-31398 on early-stage adenomas were determined by feeding 7-week-old female C57BL/6J-APC(min) (heterozygous) and wild-type C57BL/6J mice with American Institute of Nutrition-76A diets containing 0, 100, or 200 ppm of CP-31398 for 75 days. To examine activity toward late-stage adenomas, CP-31398 administration was delayed until 15 weeks of age and continued for 50 days. During early-stage intervention, dietary CP-31398 suppressed development of intestinal tumors by 36% (P < 0.001) and 75% (P < 0.0001), at low and high dose, respectively. During late-stage intervention, CP-31398 also significantly suppressed intestinal polyp formation, albeit to a lesser extent than observed with early intervention. Adenomas in treated mice showed increased apoptotic cell death and decreased proliferation in conjunction with increased expression of p53, p21(WAF1/CIP), cleaved caspase-3, and cleaved poly(ADP-ribose) polymerase. These observations show for the first time that the p53-modulating agent CP-31398 possesses significant chemopreventive activity in vivo against intestinal neoplastic lesions in genetically predisposed APC(min/+) mice. Chemopreventive activity of other agents that restore tumor suppressor functions of mutant p53 in tumor cells is currently under investigation.
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PMID:Suppression of familial adenomatous polyposis by CP-31398, a TP53 modulator, in APCmin/+ mice. 1879 56

Expression levels of intact tumor suppressor proteins and molecular targets of anti-neoplastic agents are critical in defining cancer cell drug sensitivity; however, the intracellular location of a specific protein may be as important. Many tumor suppressor proteins must be present in the cell nucleus to perform their policing activities or for the cell to respond to chemotherapeutic agents. Nuclear proteins needed to prevent cancer initiation or progression or to optimize chemotherapeutic response include the tumor suppressor proteins p53, APC/beta-catenin, and FOXO family genes; negative regulators of cell cycle progression and survival such as p21(CIP1) and p27(KIP1;) and chemotherapeutic targets such as DNA topoisomerases I and IIalpha. Mislocalization of a nuclear protein into the cytoplasm can render it ineffective as a tumor suppressor or as a target for chemotherapy. Blocking nuclear export of any or all of these proteins may restore tumor suppression or apoptosis or, for topoisomerases I and IIalpha, reverse drug resistance to inhibitors of these enzymes. During disease progression or in response to the tumor environment, cancer cells appear to acquire intracellular mechanisms to export anti-cancer nuclear proteins. These mechanisms generally involve modification of nuclear proteins, causing the proteins to reveal leucine-rich nuclear export signal protein sequences. Subsequent export is mediated by CRM1. This review defines the general processes involved in nuclear export mediated by CRM1/RanGTP (exportin/XPO1), examines the functions of individual tumor suppressor nuclear proteins and nuclear targets of chemotherapy, and explores potential mechanisms of cancer cells to induce export of these proteins. Novel drugs that could potentially counteract nuclear export of specific proteins are also discussed.
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PMID:CRM1-mediated nuclear export of proteins and drug resistance in cancer. 1899 27

HTLV-1 Tax can induce senescence by up-regulating the levels of cyclin-dependent kinase inhibitors p21(CIP1/WAF1) and p27(KIP1). Tax increases p27(KIP1) protein stability by activating the anaphase promoting complex/cyclosome (APC/C) precociously, causing degradation of Skp2 and inactivation of SCF(Skp2), the E3 ligase that targets p27(KIP1). The rate of p21(CIP1/WAF1) protein turnover, however, is unaffected by Tax. Rather, the mRNA of p21(CIP1/WAF1) is greatly up-regulated. Here we show that Tax increases p21 mRNA expression by transcriptional activation and mRNA stabilization. Transcriptional activation of p21(CIP1/WAF1) by Tax occurs in a p53-independent manner and requires two tumor growth factor-beta-inducible Sp1 binding sites in the -84 to -60 region of the p21(CIP1/WAF1) promoter. Tax binds Sp1 directly, and the CBP/p300-binding activity of Tax is required for p21(CIP1/WAF1) trans-activation. Tax also increases the stability of p21(CIP1/WAF1) transcript. Several Tax mutants trans-activated the p21 promoter, but were attenuated in stabilizing p21(CIP1/WAF1) mRNA, and were less proficient in increasing p21(CIP1/WAF1) expression. The possible involvement of Tax-mediated APC/C activation in p21(CIP1/WAF1) mRNA stabilization is discussed.
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PMID:Induction of p21(CIP1/WAF1) expression by human T-lymphotropic virus type 1 Tax requires transcriptional activation and mRNA stabilization. 1935 50

Leiomyosarcoma (LMS) is a relatively uncommon malignant tumour derived from smooth muscle cells that rapidly metastasizes to distant regions. It rarely reaches oral tissues in which smooth muscle tissues are absent. We report the case of a 56-year-old woman who presented with LMS in the maxilla that had metastasized from a primary tumour in her uterus, received a total hysterectomy with bilateral salpingo-oophorectomy 9 months earlier. To reveal the poor prognosis of metastatic LMS, a total of 26 antibodies against different factors related to the proliferation, apoptosis, necrosis, and angiogenesis were simultaneously applied on the immunohistochemistry and immuno-blot detection in order to screen for expression n of different proteins in the metastatic LMS. Compared with the immunoreactions of primary uterine LMS, the different antibodies for cellular proliferation, i.e., proliferating cell nuclear antigen (PCNA), multiple primary neoplasm-2 (MPN-2), Max, p21, CDK4, p53, Rb-1, Bad, Bcl-2, epidermal growth factor receptor (EGF-R), hepatocyte growth factor (HGF), C-erbb2, Maspin, and DMBT-1, and those for angiogenesis, i.e., vWF, CD31, and Angiogenin, were more intensely expressed, while Bax, p16, Wnt-1, E-cadherin, and APC were relatively weakly expressed. In particular, beta-catenin was densely localized to the nuclei of tumour cells. These data suggest that rapid proliferation of the tumour cells is related to over-expression of different oncogenes, and that the infiltrative growth and early distant metastasis of these tumour cells are related to over-expression of angiogenesis factors. A total of seven cases of metastatic LMS to the oral cavity that had been published in the English literature were reviewed, and the reason for the poor prognosis in the metastatic LMS is suggested in this case report.
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PMID:Metastatic leiomyosarcoma in the oral cavity: case report with protein expression profiles. 1966 33


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