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Mutational Status (mutational + status)
Selected AbstractsCombined analysis of specific KRAS mutation, BRAF and microsatellite instability identifies prognostic subgroups of sporadic and hereditary colorectal cancerINTERNATIONAL JOURNAL OF CANCER, Issue 11 2010Inti Zlobec Abstract Confounding effects of specific KRAS gene alterations on colorectal cancer (CRC) prognosis stratified by microsatellite instability (MSI) and BRAFV600E have not yet been investigated. The aim of our study was to evaluate the combined effects of MSI, BRAFV600E and specific KRAS mutation (Gly , Asp; G12D, Gly , Asp, G13D; Gly , Val; G12V) on prognosis in 404 sporadic and 94 hereditary CRC patients. MSI status was determined according to the Bethesda guidelines. Mutational status of KRAS and BRAFV600E was assessed by direct DNA sequencing. In sporadic CRC, KRAS G12D mutations had a negative prognostic effect compared to G13D and wild-type cancers (p = 0.038). With MSI, specific KRAS and BRAFV600E mutations, 3 distinct prognostic subgroups were observed in univariate (p = 0.006) and multivariable (p = 0.051) analysis: patients with (i) KRAS mutation G12D, G12V or BRAFV600E mutation, (ii) KRAS/BRAFV600E wild-type or KRAS G13D mutations in MSS/MSI-L and (iii) MSI-H and KRAS G13D mutations. Moreover, none of the sporadic MSI-H or hereditary patients with KRAS G13 mutations had a fatal outcome. Specific KRAS mutation is an informative prognostic factor in both sporadic and hereditary CRC and applied in an algorithm with BRAFV600E and MSI may identify sporadic CRC patients with poor clinical outcome. [source] An optimized whole blood method for flow cytometric measurement of ZAP-70 protein expression in chronic lymphocytic leukemiaCYTOMETRY, Issue 4 2006T. Vincent Shankey Abstract Background: ZAP-70 protein expression has been proposed as a marker for immunoglobulin heavy chain mutational status, which some studies have correlated with disease course in B-cell chronic lymphocytic leukemia (CLL). Studies published to date measuring levels of expression of ZAP-70 intracellular protein using flow cytometry have demonstrated poor performance, as defined by the difference in signal in known positive and negative lymphocyte populations. Methods: A recently published method (Chow S, Hedley DW, Grom P, Magari R, Jacobberger JW, Shankey TV, Cytometry A 2005;67:4,17) to measure intracellular phospho-epitopes was optimized using a design of experiments (DOE) approach to provide the best separation of ZAP-70 expression in positive T- or NK-cells as compared to negative B-cells in peripheral blood samples. A number of commercially available anti-ZAP-70 antibody-conjugates were screened using this methodology, and the antibody-conjugate showing the best performance was chosen to develop a four-color, five antibody assays to measure ZAP-70 levels in whole blood specimens. Results: Using the optimized fixation and permeabilization method, improvement in assay performance (signal-to-noise, S/N) was seen in most of the antibodies tested. The custom SBZAP conjugate gave the best S/N when used in conjunction with this optimized fixation /permeabilization method. In conjunction with carefully standardized instrument set-up protocols, we obtained both intra- and interlaboratory reproducibility in the analysis of ZAP-70 expression in whole blood samples from normal and CLL patients. Conclusions: The development of a sensitive, specific and highly reproducible ZAP-70 assay represents only the first essential step for any clinical assay. The universal implementation of a validated data analysis method and the establishment of methodology-based cutoff points for clinical outcomes must next be established before ZAP-70 protein analysis can be routinely implemented in the clinical laboratory. © 2006 International Society for Analytical Cytology [source] Comparison of bone marrow and peripheral blood ZAP-70 status examined by flow cytometric immunophenotyping in patients with chronic lymphocytic leukemiaCYTOMETRY, Issue 4 2006Rachel Sheridan Abstract Background: The mutational status of the immunoglobulin heavy chain variable gene in patients with chronic lymphocytic leukemia correlates with prognosis. Patients with mutated IgVH genes fare better than those with unmutated genes. Gene expression profiling studies identified the tyrosine kinase ZAP-70 to be expressed in unmutated CLL samples. Flow cytometric examination of ZAP-70 expression in tumor cells has been proposed to be a convenient surrogate marker for IgVH mutational status. However, a few studies have shown a small number of discordant results between ZAP-70 positivity, IgVH mutational status, and clinical outcome. There have been no reported studies comparing bone marrow samples with peripheral blood for ZAP-70 expression in CLL patients. Methods: We searched our flow cytometry files from October 2004 through April 2006 and identified CLL in 311 bone marrow and peripheral blood specimens from 256 patients. We defined ZAP-70 positivity as greater than 30% of the CD19+ B-cells above the isotype control value that coexpress ZAP-70. Statistical analyses were performed using the Fisher exact test and student t -test. Results: A significantly greater number of bone marrow specimens were positive for ZAP-70 when compared with the number of peripheral blood specimens. Of all the ZAP-70 negative specimens, CLL cells from bone marrow had a greater mean percentage of ZAP-70 positive cells when compared with the CLL cells from peripheral blood. Finally, six patients were identified who were ZAP-70 positive in the bone marrow but ZAP-70 negative in the peripheral blood. Conclusions: These results may be due to either an increase in the false positive rate in bone marrow specimens or to an intrinsic feature of CLL cells in the compartment that is biologically distinct from peripheral tumor cells. As prognosis and treatment decisions may be based on ZAP-70 results from either specimen type, it is prudent to further examine this observation. © 2006 International Society for Analytical Cytology [source] CLLU1 expression levels predict time to initiation of therapy and overall survival in chronic lymphocytic leukemiaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2006Anne Mette Buhl Abstract:,Objectives:,Chronic lymphocytic leukemia (CLL) is an incurable disease with a highly variable clinical course. IgVH mutational status, chromosomal aberrations, CD38 expression and ZAP-70 expression are prognostic markers in CLL, however, they are not exclusively confined to this disease. We recently identified a novel CLL-specific gene (CLL upregulated gene1, CLLU1) that is exclusively upregulated in CLL cells. Here we describe our evaluation of the prognostic significance of CLLU1 in CLL. Methods:,A cohort of 59 previously untreated CLL patients was studied. We determined the expression levels of two CLLU1 transcripts, cDNA1 and CDS, by quantitative RT-PCR. The relation between CLLU1 expression and time to therapy, overall survival and presence or absence of ZAP-70, CD38, chromosomal aberrations or IgVH mutations in the 59 patients was analyzed. Results:,Analyzed as a continuous, quantitative parameter CLLU1 levels significantly predicted time from diagnosis to initiation of therapy (P , 0.0003) Analyzed as a categorical parameter, by segregation of the patients into groups with cDNA1 or CDS expression above or below the median, the CLLU1 levels significantly predicted time from diagnosis to initiation of therapy (P = 0.001) and predicted overall survival with borderline significance (P , 0.05). Patient stratification according to clinical stage, cytogenetics, IgVH mutational status, ZAP-70 and CD38, demonstrated significantly increased CLLU1 expression in all investigated CLL poor risk groups. CLLU1 expression levels contributed additional prognostic information to ZAP-70-positive patients. Conclusions:,CLLU1 is the first identified CLL specific gene. The CLLU1 mRNA expression level can predict time to initiation of treatment and survival in CLL patients. [source] Analysis of somatic APC mutations in rare extracolonic tumors of patients with familial adenomatous polyposis coliGENES, CHROMOSOMES AND CANCER, Issue 2 2004Hendrik Bläker Patients with familial adenomatous polyposis coli (FAP) carry heterozygous mutations of the APC gene. At a young age, these patients develop multiple colorectal adenomas that consistently display a second somatic mutation in the remaining APC wild-type allele. Inactivation of APC leads to impaired degradation of ,-catenin, thereby promoting continuous cell-cycle progression. The role of APC inactivation in rare extracolonic tumors of FAP patients has not been characterized sufficiently. Among tissue specimen from 174 patients with known APC germ-line mutations, we identified 8 tumors infrequently seen in FAP. To investigate the pathogenic role of APC pathway deregulation in these lesions, they were analyzed for second-hit somatic mutations in the mutational cluster region of the APC gene. Immunohistochemistry was performed to compare the expression pattern of ,-catenin to the mutational status of the APC gene. Exon 3 of the ,-catenin gene (CTNNB1) was analyzed for activating mutations to investigate alternative mechanisms of elevated ,-catenin concentration. Although CTNNB1 mutations were not observed, second somatic APC mutations were found in 4 of the 8 tumors: a uterine adenocarcinoma, a hepatocellular adenoma, an adrenocortical adenoma, and an epidermal cyst. These tumors showed an elevated concentration of ,-catenin. No APC mutations were seen in focal nodular hyperplasia of the liver, angiofibrolipoma, and seborrheic wart. This is the first study reporting second somatic APC mutations in FAP-associated uterine adenocarcinoma and epidermal cysts. Furthermore, our data strengthen a role for impaired APC function in the pathogenesis of adrenal and hepatic neoplasms in FAP patients. © 2004 Wiley-Liss, Inc. [source] Near-diploid and near-triploid human sporadic colorectal adenocarcinomas differ for KRAS2 and TP53 mutational statusGENES, CHROMOSOMES AND CANCER, Issue 2 2003Walter Giaretti Mutations of the KRAS2 protoncogene and inactivation of the TP53 oncosuppressor gene have been suggested to contribute to chromosomal instability (CIN) and aneuploidy in colorectal cancer (CRC). Previous work has also shown that the degree of DNA ploidy [DNA index (DI)], as obtained by flow cytometry in CRC, is non-randomly distributed and, in particular, that DI near-diploid and near-triploid values are well separated by a low-probability valley region. At present, it is not known whether a relationship exists between DI and the mutational status of KRAS2 and TP53. Multiple samples obtained from 35 human sporadic CRCs have been used to provide nuclei suspensions for flow cytometric analysis and sorting of specific DI subpopulations. Sorted nuclei were then used to analyze the high-microsatellite-instability (MSI-H) phenotype and the mutation spectrum of the KRAS2 and TP53 genes. A single MSI-H case was detected. There were 6 DNA diploid (DI = 1) and 29 aneuploid (DI , 1) CRCs, with the DI aneuploid cases non-randomly subdivided in 9 near-diploid (DI , 1 and DI , 1.4), 8 near-triploid (1.4 < DI < 1.6), and 12 high-aneuploid (DI , 1.6) cases. Proximal CRCs were more often DNA diploid and near-diploid than distal ones, and Dukes' C cases were more commonly high-aneuploid than Dukes' B. Moreover, the incidence of mutations of the KRAS2 and TP53 genes was lowest among the DNA near-triploid subpopulations and highest among the near-diploid ones. We suggest that DNA near-diploid and near-triploid subpopulations in human sporadic CRC reflect different genetic mechanisms of CIN and have a potentially different clinical behavior. © 2003 Wiley-Liss, Inc. [source] Different expression of P14ARF defines two groups of breast carcinomas in terms of TP73 expression and TP53 mutational statusGENES, CHROMOSOMES AND CANCER, Issue 2 2001Gemma Domķnguez In 95 breast carcinomas, we investigated P14ARF and TP73 mRNA expression and their relationship to TP53 mutations, determined by an immunohistochemical method, studying several clinicopathologic features of the tumors. P14ARF and TP73 mRNA levels were determined by semiquantitative reverse transcription polymerase chain reaction (RT-PCR), using ,-actin as a control. P14ARF was overexpressed in 19% of the cases and underexpressed in 24%. TP73 was overexpressed in 22% of the tumors, and normal levels were found in the remaining 78%. The analysis of TP53 showed positive immunostaining in 38% of cases. The association of P14ARF and TP73 overexpression was statistically significant, as was the association between positive TP53 staining and TP73 overexpression. P14ARF was related to TP53 only in those cases in which there was low expression of P14ARF. Concomitant overexpression of P14ARF and TP73 was statistically related to positive TP53 immunostaining. The analysis of concomitant P14ARF and TP73 overexpression and clinicopathologic parameters of the tumors showed a statistically significant difference with respect to peritumoral vessel invasion (P = 0.01), lymph node metastasis (P = 0.03), negative ERBB2 expression (P = 0.005), and more advanced pathologic stages (P = 0.03). These results suggest that overexpression of P14ARF and TP73 could be implicated in breast carcinoma tumorigenesis and, ultimately, in the phenotypic features of these lesions. © 2001 Wiley-Liss, Inc. [source] EGFR and KRAS status of primary sarcomatoid carcinomas of the lung: Implications for anti-EGFR treatment of a rare lung malignancyINTERNATIONAL JOURNAL OF CANCER, Issue 10 2009Antoine Italiano Abstract Sarcomatoid carcinomas (SC) of the lung are uncommon malignant tumors composed of carcinomatous and sarcomatous cell components and characterized by a more aggressive outcome than other histological subtypes of nonsmall cell lung cancer (NSCLC). Although epidermal growth factor receptor (EGFR)-targeted therapies have emerged as a promising therapeutic approach in patients with advanced typical NSCLC such as adenocarcinoma, the potential clinical activity of these drugs in lung SC is still unknown. To investigate this point, we have analyzed the status of 4 EGFR pathways biomarkers in a series of lung SC. EGFR protein expression, EGFR gene copy number, EGFR mutational status and KRAS mutational status were assessed in a series of 22 consecutive cases of primary lung SC. EGFR protein overexpression was observed in all the cases. High level of polysomy (,4 copies of the gene in >40% of cells) was detected in 5 cases (23%). No EGFR mutation was detected. KRAS mutations were found in 8 patients (38%; Gly12Cys in 6 cases and Gly12Val in 2 cases). The consistent EGFR protein overexpression and the high rate of KRAS mutation may contribute to the poorer outcome of lung SC in comparison with typical NSCLC. The rare incidence of increased EGFR gene copy number, the lack of EGFR mutation and the high rate of KRAS mutation observed in our series also suggest that most patients with lung SC are not likely to benefit from anti-EGFR therapies. © 2009 UICC [source] Different structural components of conventional papillary thyroid carcinoma display mostly identical BRAF statusINTERNATIONAL JOURNAL OF CANCER, Issue 1 2007Alexander Abrosimov Abstract Activating BRAFT1799A mutation is closely associated with a papillary thyroid carcinoma (PTC) histotype. The transversion is frequently detected in the conventional type, Warthin-like and tall cell variants, but is rare in the follicular variant of PTC. Conventional PTC is often presented with tumors of mixed architecture, which besides the papillary structures also contain areas with follicular and solid morphology in which the details of BRAF mutational status are unknown. We set out to differentially investigate the presence of mutated BRAF in the individual structural components microdissected from 44 formalin-fixed, paraffin-embedded PTC tissues from 40 patients. The mutation was detected in at least 1 structural component in 23 tumors (52%). Different structural components of the same tumor had identical BRAF status in 41/44 tumors (93%). In 3 tumors the BRAFT1799A mutation was found only in the papillary, but not in the follicular component. Mutational patterns identical to those in the primary tumors were found in 11/12 lymph node metastases (92%, including both BRAFT1799A -positive and -negative cases). The high concordance of the BRAF mutational status in structurally distinct areas suggests a rather homogeneous distribution of neoplastic epithelial cells in a conventional PTC tumor in most cases. These results imply the reliability of preoperative molecular diagnosis of PTC regardless of the type of tumor component at the site of biopsy sampling and suggest that the majority of patients with BRAF mutation-positive PTC may benefit from the targeted pharmacotherapy. © 2006 Wiley-Liss, Inc. [source] p73: Structure and functionPATHOLOGY INTERNATIONAL, Issue 8 2000Shingo Ichimiya Alteration of the p53 tumor suppressor gene is a common, if not general, observation in human malignant tumors. p73 Is a novel member of the p53 family at chromosome 1p36.3, at which locus frequent defects are seen in many tumors including neuroblastoma. Besides structural similarities, the fact that p73 functions in the regulation of the cell cycle and apoptosis promotes the expansion of the research field concerning p53-associated tumor progression. In this paper, we review the structure and function of p73 as well as the mutational status in various human tumors. In addition, possibilities for new therapeutic applications with p73 for cancer cell control are discussed. [source] Cytoreductive therapy in 108 adults with systemic mastocytosis: Outcome analysis and response prediction during treatment with interferon-alpha, hydroxyurea, imatinib mesylate or 2-chlorodeoxyadenosine,AMERICAN JOURNAL OF HEMATOLOGY, Issue 12 2009Ken H. Lim Cytoreductive therapy in systemic mastocytosis (SM) includes several drugs whose individual merit has not been well characterized. We retrospectively studied 108 Mayo Clinic patients who met the 2008 WHO diagnostic criteria for SM and received at least one cytoreductive drug. The numbers of patients who were evaluable for response to treatment with interferon-alpha with or without prednisone (IFN-,), hydroxyurea (HU), imatinib mesylate (IM) or 2-chlorodeoxyadenosine (2-CdA) were 40, 26, 22, and 22, respectively. The corresponding overall (major) response rates, according to recently published consensus criteria, were 53% (18%), 19% (0%), 18% (9%), and 55% (37%). The respective overall response rates in indolent SM, aggressive SM and SM associated with another clonal hematological nonmast cell lineage disease (SM-AHNMD) were 60%, 60%, 45% for IFN-,, 0, 0, 21% for HU, 14%, 50%, 9% for IM and 56%, 50%, 55% for 2-CdA. The absence of mast cell mediator release symptoms in IFN-,-treated patients and presence of circulating immature myeloid cells in 2-CdA-treated patients predicted inferior response. TET2 mutational status did not influence treatment response. Although the major response rates with these four cytoreductive agents were still suboptimal and HU was mainly used in patients with SM-AHNMD, the current study favors 2-CdA or IFN-, as first-line current therapy in SM and identifies patients who are likely to respond to such therapy. Am. J. Hematol., 2009. © 2009 Wiley-Liss, Inc. [source] Blast phase of essential thrombocythemia: A single center study,AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2009Francesco Passamonti Blast phase (BP) may occur as a late event in essential thrombocythemia (ET). This study includes 19patients with post-ET BP diagnosed and followed in a single institution. At BP, 63% of patients had leukocytosis (white blood cell count >10 × 109/L), 74% had anemia (hemoglobin value <10 g/dL), 74% had thrombocytopenia (platelet count <100 × 109/L), and 84% were over 65 years of age. Cytogenetic analysis was available in 10 patients: six had karyotype aberrations. According to cytogenetic-based risk stratification of de novo acute leukemia (AL), all patients had an unfavorable profile. JAK2 (V617F) mutational status was evaluated in five patients. In two of them, the JAK2 mutation was undetectable in blast cells (one with JAK2 -positive ET), whereas in three both granulocytes and blast cells displayed the mutation. Treatment of BP was patient-based according to the performance status and co-morbidities and consisted of palliation in 14 patients, and of induction of remission in five. Median survival was 2.3 months (range 0.2,22.3), irrespective of the treatment received. In conclusion, this study indicates that AL evolved from ET has unfavorable clinical and biological features. JAK2 (V617F)-positive ET may evolve in few instances into JAK2 -negative leukemia. The outcome of patients is poor whatever the treatment used. Am. J. Hematol., 2009. © 2009 Wiley-Liss, Inc. [source] Beta-catenin status in paediatric medulloblastomas: correlation of immunohistochemical expression with mutational status, genetic profiles, and clinical characteristics,THE JOURNAL OF PATHOLOGY, Issue 1 2009Sarah Fattet Abstract Medulloblastoma is the most frequent malignant paediatric brain tumour. The activation of the Wnt/,-catenin pathway occurs in 10-15% of medulloblastomas and has been recently described as a marker for favourable patient outcome. We report a series of 72 paediatric medulloblastomas evaluated for ,-catenin protein expression, CTNNB1 mutations, and comparative genomic hybridization. Gene expression profiles were also available in a subset of 40 cases. Immunostaining of ,-catenin showed extensive nuclear staining (>50% of the tumour cells) in six cases and focal nuclear staining (<10% of cells) in three cases. The other cases either exhibited a signal strictly limited to the cytoplasm (58 cases) or were negative (five cases). CTNNB1 mutations were detected in all ,-catenin extensively nucleopositive cases. The expression profiles of these cases documented strong activation of the Wnt/,-catenin pathway. Remarkably, five out of these six tumours showed a complete loss of chromosome 6. In contrast, cases with focal nuclear ,-catenin staining, as well as tumours with negative or cytoplasmic staining, never demonstrated CTNNB1 mutation, Wnt/,-catenin pathway activation or chromosome 6 loss. Patients with extensive nuclear staining were significantly older at diagnosis and were in continuous complete remission after a mean follow-up of 75.7 months (range 27.5,121.2 months) from diagnosis. All three patients with focal nuclear staining of ,-catenin died within 36 months from diagnosis. Altogether, these data confirm and extend previous observations that CTNNB1 -mutated tumours represent a distinct molecular subgroup of medulloblastomas with favourable outcome, indicating that therapy de-escalation should be considered. International consensus on the definition criteria of this distinct medulloblastoma subgroup should be achieved. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Mutational analysis of caspase genes in prostate carcinomasAPMIS, Issue 4 2010MIN SUNG KIM Kim MS, Park SW, Kim YR, Lee JY, Lim HW, Song SY, Yoo NJ, Lee SH. Mutational analysis of caspase genes in prostate carcinomas. APMIS 2010; 118: 308,12. Evasion of apoptosis is one of the hallmarks of cancer. Of the components of apoptosis machinery, caspases are the main executioners of apoptosis that initiate and propagate the apoptosis, and finally degrade target molecules. Caspase-encoding genes have been reported to harbor inactivating mutations in many human cancers. However, mutational status of caspase genes in prostate carcinomas has not been identified. The aim of this study was to explore whether caspase genes are somatically mutated in prostate carcinomas. For this, we analyzed entire coding regions of 11 human caspase-encoding genes (CASP1,10 and 14) in 45 prostate carcinoma tissues by a single-strand conformation polymorphism (SSCP) assay. In this study, however, we detected no somatic mutation of CASP genes in the prostate carcinomas by the SSCP. This is the first report on systematic evaluation of caspase-encoding gene mutations in human prostate carcinomas, and our data indicate that CASP genes may not be mutated in prostate carcinomas. The data suggest that apoptosis evasion in prostate carcinoma may be dependent on other mechanisms besides genetic alteration of caspase-encoding genes. [source] The successful management of two pregnancies with wild type metastatic gastrointestinal stromal tumorsASIA-PACIFIC JOURNAL OF CLINICAL ONCOLOGY, Issue 3 2009Thean Hsiang TAN Abstract Aim: To discuss the management of the uncommon situation of metastatic gastrointestinal tumour coexisting with pregnancy. Method: We describe two cases of women with metastatic gastrointestinal stromal tumor (GIST) who successfully achieved a full-term pregnancy without complications and with the delivery of healthy infants. In both cases, treatment with imatinib mesylate was withheld during pregnancy because of its unknown effects and questionable safety for the developing fetus. The available data in the medical literature regarding the use and safety of imatinib and pregnancy are reviewed. We also examine whether the knowledge of the exon mutational status would have influenced treatment decisions. Results: Both women had wild type GIST, but with different tumor growth characteristics, treatment responses and outcomes. The first patient deferred imatinib therapy to fall pregnant and her disease progressed rapidly off treatment. The second patient had a more indolent GIST where active surgical management allowed her to experience a long durable clinical response. She potentially belongs to a pediatric subgroup which carries a better prognosis despite being off imatinib. Conclusion: While we have successfully managed two pregnant women with metastatic GIST, the issue of initiating imatinib therapy in treatment-naive women, and treatment interruption in women already on therapy, remain difficult areas. Patients and their partners need to make an informed choice regarding the associated risks and the potential long-term sequelae if pregnancies are contemplated. Further research into the natural history of wild type GIST and how to tailor subsequent treatment are needed. [source] Mutant p53 melanoma cell lines respond differently to CP-31398-induced apoptosisBRITISH JOURNAL OF DERMATOLOGY, Issue 5 2005C.K. Ho Summary Background, p53, a commonly mutated gene in human cancers, participates in cell cycle arrest, DNA repair and apoptosis. A small pharmacological compound, CP-31398, was found to have the ability to promote proper p53 protein folding, activate p53 transcription of downstream targets, and slow tumour growth in mice. Additionally, CP-31398 was found to be able to convert mutant p53 to wild-type conformation in several cell lines. Objectives, To examine if CP-31398 can revert all mutant p53 proteins to wild-type function. Methods, We studied a series of apoptotic responses to CP-31398 in three melanoma cell lines varying in p53 mutation status. Results, Upon a moderate dose of CP-31398 treatment (15 µg mL,1), only the wild-type p53 MMRU and the single p53 point mutation MeWo cells exhibited apoptosis. Another melanoma cell line, Sk-mel-110, containing multiple p53 mutations, did not exhibit apoptosis. Although CP-31398 enhanced overall p53 protein level, its ability to promote proper folding of p53 protein was limited to CP-31398-sensitive MMRU and MeWo cells. These sensitive cells showed an increased Bax and PUMA transcription, altered mitochondrial membrane potential, followed by the release of cytochrome c, and cleaved caspase-9 and caspase-3. We also demonstrated that Apaf-1 was not involved in CP-31398-mediated apoptosis. Conclusions, Our results suggest that the ability of CP-31398 to revert mutant p53 proteins to wild-type conformation may be correlated to p53 mutational status. More studies are necessary, to further investigate the effect of CP-31398 on mutant p53 and its potential applications as an anticancer agent. [source] Evidence for allelic evolution of C/EBPalpha mutations in acute myeloid leukaemiaBRITISH JOURNAL OF HAEMATOLOGY, Issue 3 2003Jens Tiesmeier Summary. Transcription factor CCAAT/enhancer binding protein , (C/EBP,) is mutated in 6,10% of patients with acute myeloid leukaemia (AML). Recently, we reported the emergence of an N-terminal C/EBP, mutation after chemotherapy in a patient with secondary AML. The clone carrying the mutation became the dominant clone at relapse. This observation prompted us to compare the C/EBP, mutational status of 26 de novo non-core binding factor AML patients at diagnosis and at relapse after induction and consolidation chemotherapy. Four mutations in the C/EBP, gene were identified in two out of 26 patients. In both these cases, a biallelic mutation was present at diagnosis and at relapse: an amino-terminal frameshift mutation and a mutation of the fork/leucine finger 1 region. In patient 1, the amino-terminal frameshift mutation was duplicated and found on both alleles at relapse. In patient 2, the amino-terminal frameshift mutation and a mutation in the fork region were found either alone or combined on the same allele, suggesting a subclone formation. None of the patients without a C/EBP, mutation at diagnosis showed a mutation at relapse. This is the first report of an evolution of the C/EBP, gene between diagnosis and relapse in AML. [source] Triptolide abrogates oncogene FIP1L1-PDGFR, addiction and induces apoptosis in hypereosinophilic syndromeCANCER SCIENCE, Issue 11 2009Yanli Jin The pathogenesis of hypereosinophilic syndrome (HES) in some patients is highly dependent on FIP1-Like-1 (FIP1L1),platelet-derived growth factor receptor alpha (PDGFR,), which can generate sustained activation signaling to maintain a cell malignant phenotype. HES usually shows good response to the tyrosine kinase inhibitor imatinib, but mutations in FIP1L1-PDGFR, (e.g. T674I) can confer acquired resistance to imatinib. An alternative therapeutic strategy other than with tyrosine kinase inhibitors is needed to overcome acquired drug resistance. We hypothesized that switching off the crucial chimeric oncoprotein FIP1L1-PDGFR, on which HES cells depend, should have deleterious effects on the cancer cells. We used low concentrations of triptolide, a transcription inhibitor, to shut down the expression of FIP1L1-PDGFR,. EOL-1 cells and BaF3 cells expressing wild-type or T674I FIP1L1-PDGFR, were treated with triptolide, and signaling pathways, cell cycling, and apoptosis were analyzed by RT-PCR, immunoblotting, and flow cytometry, respectively. The results revealed that at nanomolar concentrations triptolide decreased the levels of mRNA and protein of FIP1L1-PDGFR, and the growth of the neoplastic cells, regardless of the mutational status of PDGFR,. Triptolide also downregulated the signaling molecules Stat3, Akt, and Erk1/2, which are downstream from PDGFR,, and induced G1 cell-cycle arrest. Triptolide time- and dose-dependently induced apoptosis by decreasing the anti-apoptotic proteins Mcl-1 and Bcl-XL,triggering the intrinsic apoptotic pathway. In conclusion, triptolide has potent activity against malignant cells in HES bearing FIP1L1-PDGFR,, regardless of its mutational status that confer acquired resistance to imatinib. Our results suggest that triptolide may be a promising agent in the treatment of HES. (Cancer Sci 2009; 00: 000,000) [source] Soy consumption reduces the risk of non-small-cell lung cancers with epidermal growth factor receptor mutations among JapaneseCANCER SCIENCE, Issue 6 2008Keitaro Matsuo Epidermal growth factor receptor (EGFR) mutations play substantial roles in genesis and proliferation of non-small-cell lung cancers (NSCLCs). We recently found that reproductive factors have a substantial impact on risk of development of NSCLCs featuring such EGFR mutations. Therefore, we explored the influence of dietary habits on NSCLC risk with reference to the EGFR mutational status. We conducted a case-control study using 353 patients with NSCLCs (122 EGFR mutated and 231 EGFR wild-type) and 1765 age-sex matched non-cancer control subjects. Dietary exposure was based on a semiquantitative food frequency questionnaire and impact of major food items, like meats, seafoods, vegetables and soybean products was assessed by multivariate logistic regression. Soybean products demonstrated a protective association with EGFR mutated, but not EGFR wild-type NSCLCs, with multivariate-adjusted odds ratios and 95% confidence intervals for the 2nd and 3rd tertile of soybean product consumption of 0.79 (0.50,1.27) and 0.56 (0.34,0.93) relative to those in the lowest tertile (trend P = 0.023). In conclusion, soy consumption may exert a protective association against the development of NSCLCs with EGFR mutations, providing possible insights into mechanisms of their genesis. (Cancer Sci 2008; 99: 1202,1208) [source] | |||||||||||||||||||||||||