Selenium-enriched Agaricus bisporus mushrooms suppress 7,12-dimethlybenz[a]anthracene bioactivation in mammary tissue.

The present studies compared dietary Se (1.0 microg/g) when provided as either fortified Agaricus bisporus mushrooms, or sodium selenite on the in vivo metabolism of 7,12-dimethylbenz(a)anthracene (DMBA). Dietary addition of Se unenriched A. bisporus mushrooms at 2% did not alter the occurrence of DMBA induced DNA adducts or the activity of glutathione S-transferase (GST). However, the addition of Se as enriched mushrooms, or as selenite, significantly increased both liver and mammary GST activity. Providing sodium selenite, or enriched mushrooms also significantly reduced total and anti-3,4-dihydrodiol-1,2-epoxide-deoxyguanosine adducts compared to feeding the basal diet (P < 0.05). These investigations provide evidence that Se enriched mushrooms can be used as an effective method to retard chemically induced tumors.     

<Emphasis Type="Italic">CDC</Emphasis><Emphasis Type="BoldItalic">25A</Emphasis> gene 263C/T, -<Emphasis Type="BoldItalic">350C</Emphasis>/T,and -51C/G polymorphisms in breast carcinoma

The family of cell division cycle 25 (CDC25) phosphatase is one of the important regulators of the cell cycle progression. In mammalian cells, three isoforms have been identified: CDC25A, CDC25B, and CDC25C. CDC25A is required to enter S time, and the overexpression of this phosphatase accelerates the entrance to S time. CDC25A overexpression could render tumor cells less sensitive to DNA replication checkpoints, thereby contributing to their genomic instability. We aimed to investigate, for the first time, the frequency of human CDC25A gene SNPs in metastatic and non-metastatic breast cancer. Total number of 281 eligible patients with histologically confirmed incident of breast cancer and 137 cancer-free controls were included. The detection of CDC25A gene polymorphisms was achieved with real-time polymerase chain reaction and restriction fragment length polymorphism techniques. We found that the 263C/T polymorphism was significantly associated with breast cancer and risk of metastasis. The -350C/T polymorphism in the promoter region of CDC25A gene was found to associate with neither breast cancer nor metastasis. The other promoter polymorphism -51C/G in the CDC25A gene associated with breast cancer but not associated with metastasis. These data suggest that 263C/T and -51C/G polymorphisms of CDC25A gene could be candidate markers for earlier diagnosis and targets for breast cancer therapy.     

THE INHIBITORY EFFECT OF EXTRACT OF CAMELLIA SINENSIS AND EXTRACT OF CAMELLIA PTILOPHYLLA CHANG ON DNA POLYMERASE OF EHRLICH ASCITES CARCINOMA CELLS

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IL12 polymorphisms,HBV infection and risk of hepatocellular carcinoma in a high‐risk Chinese population

To investigate the association between the potentially functional polymorphisms in IL12A and IL12B, HBV infection and risk of hepatocellular carcinoma in a Chinese population, we genotyped three polymorphisms, rs568408 (3′UTR G>A), rs2243115 (5′UTR T>G) in IL12A and rs3212227 (3′UTR A>C) in IL12B in a case–control study of 869 hepatocellular carcinoma (HCC) cases and 891 cancer‐free controls. We found that the IL12A rs568408 GA/AA variant genotypes were associated with a significantly increased risk of HCC (adjusted odds ratio (OR) = 1.53, 95% confidence interval (CI) = 1.17–2.00), compared with the wild‐type GG homozygote. In the stratified analyses, the increased risk of HCC associated with rs568408 GA/AA was more evident in patients who were negative for HBsAg (adjusted OR = 1.71, 95% CI = 1.23–2.39). However, no significant associations between IL12A rs2243115 T/G, IL12B rs3212227 A/C and risk of HCC were observed. Our findings indicate that IL12A rs568408 may contribute to the risk of HCC and modify HCC risk associated with HBV infection.     

Serum selenium and thromboxane in patients with gynaecological cancer

To explore the relationships between the antioxidant seleniumand pro-aggregatory thromboxane A₂ in patients with gynaecologicalcancer, we measured the serum concentrations of selenium andthe production of thromboxane B₂ (TxB₂, a stable metaboliteof thromboxane A₂) by the aggregating platelets in patientswith endometrial (n = 35), ovarian (n = 30) and cervical cancer(n = 25), and in 32 control women. The selenium concentrationin endometrial (1.14 ± 0.04 µmol/1; mean ±SE), ovarian (0.96 ± 0.04 µmol/1) and cervicalcancer (0.97 ± 0.06 µmol/1) was significantly lowerthan in control subjects (1.26 ± 0.03 µmol/1).The release of TxB₂ into serum during spontaneous clotting ofthe blood was significantly increased in ovarian cancer (229.2± 15.9 ng/ml), decreased in endometrial cancer (142.6± 12.4 ng/ml) and normal in cervical cancer (185.9 ±14.8 ng/ml) as compared with control subjects (185.9 ±11.9 ng/ml). The levels of selenium and TxB₂ did not correlatewith each other in the whole series or in any subgroup. Thus,selenium does not seem to be an important determinant in thebiosynthesis of TxB₂ in patients with gynaecological malignancy.     

Polymorphisms in Inflammation-related Genes and Risk of Gastric Cancer (Finland)

Helicobacter pylori infection is an important risk factor for gastric cancer, but <3% of carriers of this organism will ever develop gastric cancer. Since inflammation plays a significant role in gastric carcinogenesis, it has been suggested that polymorphisms in genes involved in inflammatory response may partly explain why only a subgroup of patients infected with H. pylori develop gastric cancer. We compared relative frequencies of 17 single nucleotide polymorphisms (SNPs) in eight inflammation-related genes between 112 gastric cancer patients and 208 controls. Cases and controls were selected from a large cohort of Finnish male smokers who were recruited into the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. The studied SNPs were IL-1A (−889 C/T), IL-1B (−511 C/T and −31 T/C), IL-6 (−174 G/C and −597 G/A), IL-8 (−251 T/A, +396 T/G and +781 C/T), IL-8RA (Ex2 +860 G/C), IL-8RB (Exon 3 +1235 T/C, Exon 3 +811 C/T, and Exon 3 +1010 G/A), IL-10 (−819 C/T, −592 C/A, −1082 A/G), and TNF A (−308 G/A, −238 G/A). We found no statistically significant association between any of these SNPs, or the number of pro-inflammatory polymorphisms, with risk of gastric cancer. Our results do not support the hypothesis that polymorphisms in genes involved in the inflammatory response confer differences in gastric cancer risk among different individuals.     

Array CGH analysis of chronic lymphocytic leukemia reveals frequent cryptic monoallelic and biallelic deletions of chromosome 22q11 that include the PRAME gene

We used BAC array-based CGH to detect genomic imbalances in 187 CLL cases. Submicroscopic deletions of chromosome 22q11 were observed in 28 cases (15%), and the frequency of these deletions was second only to loss of the 13q14 region, the most common genomic aberration in CLL. Oligonucleotide-based array CGH analysis showed that the 22q11 deletions ranged in size from 0.34 Mb up to ～1 Mb. The minimally deleted region included the ZNF280A, ZNF280B, GGTLC2, and PRAME genes. Quantitative real-time PCR revealed that ZNF280A, ZNF280B, and PRAME mRNA expression was significantly lower in the 22q11 deletion cases compared to non-deleted cases.     

Identification of modifier genes for cutaneous malignant melanoma in melanoma‐prone families with and without CDKN2A mutations

CDKN2A is a major susceptibility gene for cutaneous malignant melanoma (CMM), but the variable penetrance and clinical manifestations among mutation carriers suggest the existence of modifier factors. The goal of this study was to identify modifier genes for CMM in CMM‐prone families with or without CDKN2A mutations. We genotyped 537 individuals (107 CMM) from 28 families (19 CDKN2A+, 9 CDKN2A?) for 1,536 SNPs in 152 genes involved in DNA repair, apoptosis and immune response pathways. We used conditional logistic regression to account for family ascertainment and differences in disease prevalence among families. Pathway‐ and gene‐based permutation analyses were used to assess the risk of CMM associated with genes in the 5 pathways (DNA repair, apoptosis, TNF/NFκB, TH1:TH2 and other immune regulation). Our analyses identified some candidate genes such as FAS, BCL7A, CASP14, TRAF6, WRN, IL9, IL10RB, TNFSF8, TNFRSF9 and JAK3 that were associated with CMM risk (p < 0.01, gene‐based test). After correction for multiple comparisons, IL9 remained significant (Bonferroni p < 0.05). The effects of some genes were stronger in CDKN2A‐positive families (BCL7A and IL9), while some were stronger in CDKN2A‐negative families (BCL2L1). Our findings support the hypothesis that common genetic polymorphisms in DNA repair, apoptosis and immune response pathways may modify the risk of CMM in CMM‐prone families with or without CDKN2A mutations. Published 2009 UICC.     

Mutations found in cell‐free DNAs of patients with malignant lymphoma at remission can derive from clonal hematopoiesis

Cell‐free DNA (cfDNA) analysis to detect circulating tumor DNA has been focused on monitoring malignant lymphomas. However, clonal hematopoiesis of indeterminate potential (CHIP)‐associated mutations can also be detected by cfDNA analysis. Our aim is to investigate the origin of mutations detected in cfDNA among B‐cell lymphoma patients. MYD88/CD79B, DNMT3A, and TP53 were chosen as genes of interest, representing each of the following categories: lymphoma driver genes, CHIP‐related genes, and genes shared between lymphoma and CHIP. Seventy‐five B‐cell lymphoma patients were included in this retrospective study. Serum cfDNAs at time of complete metabolic response (CMR) were sequenced for TP53 (N = 75) and DNMT3A (N = 49). MYD88 p.L265P and CD79B p.Y196C/H mutations were analyzed in diffuse large B‐cell lymphoma (DLBCL) patients whose tumor samples were available (N = 29). Two and seven mutations in TP53 and DNMT3A, respectively, were detected in cfDNA at CMR. These mutations were detected in either bone marrow mononuclear cells (BMMC) or PBMC. Although four DNMT3A mutations were also detected in tumors, median variant allele frequencies in the tumors (<1.0%) were significantly lower than those in both BMMC (6.1%) and serum (5.2%) obtained before the therapy. Conversely, five MYD88 and three CD79B mutations detected in tumors were confirmed in cfDNA before therapy, but not in BMMC nor in cfDNA at CMR. Thus, all TP53 and DNMT3A mutations detected in cfDNA at remission seemed to originate from CHIP rather than from residual disease. Results of liquid biopsy should be carefully interpreted, especially in genes shared between lymphomas and CHIP.     

Characterization of arsenic-induced cytogenetic alterations in acute promyelocytic leukemia cell line,NB4

Gain or loss of genes plays important roles in leukemogenesis of APL via cooperation with PML-RARA. Fluorescence in situ hybridization (FISH) was applied to investigate the DNA copy number changes of hTERT, ERG, CDKN1B (P27), CDKN2A (P16), and TP53 genes in an acute promyelocytic leukemia (APL) cell line (NB4). Five bacterial artificial chromosome probes (BAC) for 9p21.3, 17p13.1, 12p13.2, 5p15.33, 21q22.2 regions were prepared using sequence independent amplification (SIA) and were hybridized to NB4 cells treated with different doses of arsenic trioxide (As₂O₃; ATO) at various time intervals. NB4 cells were also karyotyped by G-banded chromosome analysis 24 h after culture initiation. FISH analysis prior to treatment showed CDKN1B, CDKN2A, and TP53 gene deletion but ERG and hTERT gene amplification. After treatment with ATO, the number of the NB4 cells with deleted CDKN1B and CDKN2A as well as the counts of the cells with hTERT amplification was significantly reduced in time- and does-dependent manners. In addition, we observed expressive increase in signal patterns of CDKN1B and CDKN2A along with significant decline in hTERT signal patterns in ATO-treated cells as compared with the control group (in time- and dose-dependent manners). On the other hand, no difference in signal patterns for Erg and p53 was observed in response to ATO exposure. The results of the present study show the cytogenetic alteration in hTERT, CDKN1B, and CDKN2A in NB4 cells after treatment with ATO might introduce a new mechanism of antitumor activities of ATO in APL cell line, NB4.     

Meta-analysis of genetic polymorphisms and gastric cancer risk: Variability in associations according to race

The goal of this study was to consolidate information on genetic risk factors for gastric cancer. An additional aim was to investigate the influence of race on these genetic risk associations. Relevant studies were identified from PubMed and references of retrieved articles. Meta-analysis techniques were used to summarise associations between genetic polymorphisms and gastric cancer. A total of 203 relevant studies were identified, assessing 225 polymorphisms across 95 genes. Subgroup analysis indicated that Chinese, Japanese and Korean data were consistent and could be pooled. However, 6 of 13 polymorphisms (ACE I/D, CCND1 870G > A, CDH1 –160C > A, IL1B –511C > T, IL4 –590C > T, IL10 –592A > C) displayed conflicting effects between Asian and Caucasian populations, three of which (ACE I/D, CCND1 870G > A, IL1B –511C > T) had significantly different odds ratios between the two racial groups. In total, 37 polymorphisms across 27 genes were found to be significantly associated with gastric cancer in Asians, and 12 polymorphisms across 11 genes in Caucasians. Consolidated panels of polymorphisms associated with gastric cancer risk were identified in Asians and Caucasians. The results caution against the assumption that genetic risk factors are consistent between races.     

Frequent alterations of LOH11CR2A, PIG8 and CHEK1 genes at chromosomal 11q24.1-24.2 region in breast carcinoma: clinical and prognostic implications

To understand the importance of frequent deletions at chromosome 11q24.1-24.2 region in breast carcinoma, alterations (deletion/methylation) of the candidate genes LOH11CR2A, ROBO3, ROBO4, HEPACAM, PIG8 and CHEK1 located in this region were analyzed in 106 breast carcinoma samples. Among these genes, LOH11CR2A showed highest frequency of deletion (56%), followed by PIG8 (35%), CHEK1 (31%) and ROBO3/ROBO4/HEPACAM loci (28%). Comparable frequency of promoter methylation (26–35%) was observed for LOH11CR2A, CHEK1 and PIG8. Overall alterations (deletion/methylation) of these genes were in the following order: LOH11CR2A (60%) > PIG8 (46%) > CHEK1 (41%) and showed significant association with each other. Breast carcinoma samples that were estrogen/progesterone receptor negative showed significantly high deletion and overall alterations than estrogen/progesterone receptor positive samples for LOH11CR2A, CHEK1 and PIG8. The methylation and overall alteration of LOH11CR2A were significantly associated with tumor stages in breast carcinoma. However, in early/late onset and estrogen/progesterone receptor positive/negative breast carcinoma, the overall alterations of LOH11CR2A, PIG8 and CHEK1 were differentially associated with advanced stages, tumor grade and lymph node metastasis. Alterations of PIG8 and CHEK1 were significantly associated with poor prognosis in patients with early age of onset of the disease indicating significant prognostic importance. Quantitative mRNA expression analysis detected reduced expression of the genes in the order LOH11CR2A > CHEK1 > PIG8. Immunohistochemical analysis showed reduced protein expression of PIG8 and CHEK1 that was concordant with their molecular alterations. Thus, our study suggests that LOH11CR2A, PIG8 and CHEK1 are candidate tumor suppressor genes associated with breast carcinoma and have significant clinical as well as prognostic importance.     

Mutation analysis of five candidate genes in familial breast cancer

Most of the known breast cancer susceptibility genes (BRCA1, BRCA2, CHEK2 and ATM) are involved in the damage response pathway. Other members of this pathway are therefore good candidates for additional breast cancer susceptibility genes. ATR, along with ATM, plays a central role in DNA damage recognition and Chk1 relays checkpoint signals from both ATR and ATM. PPP2R1B and PPP2R5B code for subunits of protein phosphatase 2A (PP2A), which regulates autophosphorylation of ATM. In addition, EIF2S6/Int-6, which was originally identified as a common integration site for the mouse mammary tumour virus in virally induced mouse mammary tumours, is a candidate breast cancer susceptibility gene because of its putative role in maintaining chromosome stability. To investigate the role of ATR, CHK1, PPP2R1B, PPP2R5B and EIF2S6/Int-6, we carried out mutation analysis of these genes in the index cases from non-BRCA1/BRCA2 breast cancer families. We also screened sporadic breast tumours for somatic mutations in PPP2R1B and PPP2R5B. Although we identified many novel variants, we found no evidence that highly penetrant germline mutations in these five genes contribute to familial breast cancer susceptibility.     

PVT1‐derived miR‐1207‐5p promotes breast cancer cell growth by targeting STAT6

Accumulating evidence indicates that ectopic expression of non‐coding RNAs are responsible for breast cancer progression. Increased non‐coding RNA PVT1, the host gene of microRNA‐1207‐5p (miR‐1207‐5p), has been associated with breast cancer proliferation. However, how PVT1 functions in breast cancer is still not clear. In this study, we show a PVT1‐derived microRNA, miR‐1207‐5p, that promotes the proliferation of breast cancer cells by directly regulating STAT6. We first confirm the positive correlated expression pattern between PVT1 and miR‐1207‐5p by observing consistent induced expression by estrogen, and overexpression in breast cancer cell lines and breast cancer patient specimens. Moreover, silence of PVT1 also decreased miR‐1207‐5p expression. Furthermore, increased miR‐1207‐5p expression promoted, while decreased miR‐1207‐5p expression suppressed, cell proliferation, colony formation, and cell cycle progression in breast cancer cell lines. Mechanistically, a novel target of miR‐1207‐5p, STAT6, was identified by a luciferase reporter assay. Overexpression of miR‐1207‐5p decreased the levels of STAT6, which activated CDKN1A and CDKN1B to regulate the cell cycle. We also confirmed the reverse correlation of miR‐1207‐5p and STAT6 expression levels in breast cancer samples. Therefore, our findings reveal that PVT1‐derived miR‐1207‐5p promotes the proliferation of breast cancer cells by targeting STAT6, which in turn controls CDKN1A and CDKN1B expression. These findings suggest miR‐1207‐5p might be a potential target for breast cancer therapy.     

An online survival analysis tool to rapidly assess the effect of 22,277 genes on breast cancer prognosis using microarray data of 1,809 patients

Validating prognostic or predictive candidate genes in appropriately powered breast cancer cohorts are of utmost interest. Our aim was to develop an online tool to draw survival plots, which can be used to assess the relevance of the expression levels of various genes on the clinical outcome both in untreated and treated breast cancer patients. A background database was established using gene expression data and survival information of 1,809 patients downloaded from GEO (Affymetrix HGU133A and HGU133+2 microarrays). The median relapse free survival is 6.43 years, 968/1,231 patients are estrogen-receptor (ER) positive, and 190/1,369 are lymph-node positive. After quality control and normalization only probes present on both Affymetrix platforms were retained (n = 22,277). In order to analyze the prognostic value of a particular gene, the cohorts are divided into two groups according to the median (or upper/lower quartile) expression of the gene. The two groups can be compared in terms of relapse free survival, overall survival, and distant metastasis free survival. A survival curve is displayed, and the hazard ratio with 95% confidence intervals and logrank P value are calculated and displayed. Additionally, three subgroups of patients can be assessed: systematically untreated patients, endocrine-treated ER positive patients, and patients with a distribution of clinical characteristics representative of those seen in general clinical practice in the US. Web address: . We used this integrative data analysis tool to confirm the prognostic power of the proliferation-related genes TOP2A and TOP2B, MKI67, CCND2, CCND3, CCNDE2, as well as CDKN1A, and TK2. We also validated the capability of microarrays to determine estrogen receptor status in 1,231 patients. The tool is highly valuable for the preliminary assessment of biomarkers, especially for research groups with limited bioinformatic resources.     

High-resolution mapping of molecular events associated with immortalization, transformation, and progression to breast cancer in the MCF10 model

Summary Background A comprehensive and consistent picture of the genetic changes that underlie breast cancer initiation, development, and progression remains unresolved. The MCF10 series of cell lines represents many steps in that progression. We performed high resolution mapping of the MCF10 series of cell lines to identify specific gene targets to elucidate the molecular correlates of immortalization, development, and progression of breast cancer at the level of individual genes. Design We evaluated the initial untransformed outgrowths (MCF-10MS and MCF-10A) with six transformed cell lines with benign proliferations (MCF-10AT1, MCF-10AT1kcl2), carcinoma in situ (MCF-10CA1h cl13), and invasive carcinoma (MCF-10CA1h cl2, MCF-10CA1a cl1, MCF-10CA1d cl1). Losses and gains of loci at 112 unique human genome sites were interrogated using the multiplex ligation-dependent probe amplification assay (MLPA). Results Cytogenetic alterations in the four benign progenitors that persisted in the CIS and invasive cell lines corresponded to gains and losses of genes by MLPA. MCF-10MS had only normal gene copies. The untransformed MCF-10A had cytogenetic gain of 5q13-qter with corresponding gains of the IL3, IL4 and IL12B genes at 5q31-q33; gain of distal 19q12-qter was reflected in gains in KLK3 and BAX gene loci at 19q13-q13.4. The observed genic gain of cMYC at 8q24.12 was not indicated by cytogenetics. The apparently balanced t(3;9) component of the t(3;9)(p13;p22)t(3;5)(p26;q31) resulted in complete loss of the CDKN2A and CDKN2B genes at 9p21. Additional clonal cytogenetic changes in the DCIS cell line (MCF-10A1h cl13) involving chromosomes 1, 3 and 10 persisted in the invasive progeny, with gain of corresponding genes at 1p13 (BCAR2, BCAR3, NRAS, TGFB2), at 3p12–13 (IL12A), and 3q21–27 (MME, PIK3CA, BCL6). Conclusions Our study adopted a comprehensive exploration of genetic changes using high resolution molecular probes applied to the MCF10 family of cell lines to identify individual genes in a continuum starting from normal breast epithelial cells and progressing through immortalization, transformation and invasive malignancy. Homozygous loss of CDKN2A and CDKN2B genes and gain of MYC were initiating immortalization events. Transformation and progression to malignancy event were marked by gains of IL13, VEGF, HRAS, TRAF2, and BCAS2, IL12A, and MME, respectively.