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[show abstract]
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ABSTRACT: Regulatory T cells (T(reg)) have often been ascribed a role in the pathophysiology of several neoplastic diseases considering their potential ability to suppress anti-tumor immunity. This is particularly the case in myelodysplastic syndromes (MDS), which are clonal hematologic disorders characterized by marked immune dysregulation. We analyzed T(reg) frequencies in a cohort of 36 patients with early-stage MDS using a flow-cytometric approach based on the concomitant expression of CD25 and CD127. MDS patients showed a higher frequency of CD4+CD25(high)+CD127(low) T(reg) than healthy controls (1.51 vs. 1.14%), with no specific effect of patient- and disease-related factors. Our data point to impaired anti-tumor immunity in patients with MDS, even in the early stage, which has already been noted in other clonal disorders.
Acta Haematologica 08/2012; 128(3):178-82. · 1.35 Impact Factor
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Antonio Galleu,
Claudio Fozza,
Maria Pina Simula,
Salvatore Contini, Patrizia Virdis,
Giovanna Corda,
Simonetta Pardini,
Francesca Cottoni,
Sara Pruneddu,
Antonio Angeloni,
Simona Ceccarelli,
Maurizio Longinotti
[show abstract]
[hide abstract]
ABSTRACT: It is widely accepted that a deranged immune system plays a key role in the onset and evolution of classic Kaposi sarcoma (CKS). Nevertheless, the usage of the T-cell receptor (TCR) β-variable (BV) chain repertoire expressed by peripheral blood lymphocytes in patients with CKS is still unknown. With the aim of providing some further insights into the complex role of the immune system in CKS pathogenesis, we performed an extensive analysis of the TCR BV repertoire in both CD4(+) and CD8(+) T cells in 30 human herpesvirus 8-positive Sardinian patients with CKS and an equal number of age-matched healthy controls. We used a panel of monoclonal antibodies covering approximately 70% of human BV subfamilies and third complementarity determining region (CDR3) spectratyping. Patients with CKS showed an increased frequency of BV expansions in both CD4(+) and CD8(+) lymphocytes, with no prevalent clones. On spectratyping analysis, most of the 720 BV CDR3 profiles obtained from both CD4(+) and CD8(+) T cells in patients with CKS were skewed. In particular, the surprising increase of BV skewing observed in CD4(+) lymphocytes mimics the pattern of progressive TCR BV narrowing described in responses to persistent viral antigen stimulations. Our findings support the hypothesis that CKS evolution is associated with inadequate activation rather than impairment of the immune system.
Neoplasia (New York, N.Y.) 06/2012; 14(6):487-94. · 5.48 Impact Factor
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Claudio Fozza,
Salvatore Contini,
Giovanna Corda, Patrizia Virdis,
Antonio Galleu,
Silvana Bonfigli,
Adolfo Pacifico,
Mario Maioli,
Francesco Mastinu,
Maristella Pitzalis,
Francesco Cucca,
Maurizio Longinotti
[show abstract]
[hide abstract]
ABSTRACT: Several data suggest that stochastic rearrangements of the TCR could play a pathogenic role in both disease predisposition and protection in type 1 diabetes (T1D). As twin sets offer an enormous potential in evaluating the role of genetic and environmental factors in susceptibility to disease, the main goal of this study was to assess whether the degree of sharing of the expressed TCR repertoire of twin pairs discordant for T1D differs from that of disease concordant pairs. We performed our analysis in 5 pairs of monozygotic twins, 3 of which were concordant and 2 discordant for T1D, by combining flow cytometry and CDR3 spectratyping on both CD4+ and CD8+ T-cells. Our data show that TCR repertoires show increased level of concordance within each twin pair, especially in CD8+ cells, in terms of mean BV expression levels on flow cytometry as well as of CDR3 patterns and frequencies of skewed or oligoclonal BV subfamilies on spectratyping. It is worth noting that the degree of similarity among twins seems to be independent of concordance or discordance for T1D. Our findings seem to suggest that in monozygotic twins with T1D the TCR repertoire is influenced by genetic factors more than by the presence of the autoimmune disorder itself.
Immunobiology 01/2012; 217(9):920-5. · 3.20 Impact Factor
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European Journal Of Haematology 09/2011; 88(1):89-90. · 2.61 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Immune dysregulation plays a role in the pathophysiology of myelodysplastic syndromes (MDS), as T-cell clones seem to be involved in the inhibition of hematopoietic precursors. The purpose of this study was to analyze the T-cell receptor (TCR) repertoire of MDS patients, focusing on the third complementarity determining region (CDR3) pattern of their CD4(+) and CD8(+) lymphocyte expansions.
The study involved 30 patients and 15 age-matched controls. The beta-variable (betaV) subfamily flow-cytometry analysis was performed on peripheral CD4(+) and CD8(+) T-cells. Spectratyping TCR-CDR3 analysis was carried out on isolated helper and cytotoxic T lymphocytes after immunomagnetic separation and reverse-transcriptase polymerase chain reaction.
We first identified by flow cytometry an increased frequency of expanded betaVs in both CD4(+) and CD8(+) T-cells in MDS patients. We then showed, by spectratyping, that the CDR3 profile was mostly Gaussian in their CD4(+) T cells, whereas CD8(+) T cells usually showed skewed or oligoclonal CDR3 regions. When we compared spectratyping and flow-cytometry findings in each patient, we showed that most CD4(+) lymphocyte expansions detected by flow cytometry had Gaussian CDR3 profiles, whereas most CD8(+) expansions were oligoclonal.
We confirm that in MDS patients the TCR-betaV repertoire is overall extremely contracted, especially in cytotoxic T cells. This pattern is mainly determined by selective proliferations of both helper and cytotoxic T cells, which are, however, mostly polyclonal in the former and oligoclonal in the latter. Such a difference, possibly related to the different human leukocyte antigen restriction, could reflect the selective involvement of cytotoxic T cells either in the anti-tumor immune surveillance or in an autoreactive aggression toward hematopoietic precursors.
Experimental hematology 05/2009; 37(8):947-55. · 3.11 Impact Factor
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Diego F Calvisi,
Federico Pinna,
Floriana Meloni,
Sara Ladu,
Rossella Pellegrino,
Marcella Sini,
Lucia Daino,
Maria M Simile,
Maria R De Miglio, Patrizia Virdis,
Maddalena Frau,
Maria L Tomasi,
Maria A Seddaiu,
Maria R Muroni,
Francesco Feo,
Rosa M Pascale
[show abstract]
[hide abstract]
ABSTRACT: Sustained activation of extracellular signal-regulated kinase (ERK) has been detected previously in numerous tumors in the absence of RAS-activating mutations. However, the molecular mechanisms responsible for ERK-unrestrained activity independent of RAS mutations remain unknown. Here, we evaluated the effects of the functional interactions of ERK proteins with dual-specificity phosphatase 1 (DUSP1), a specific inhibitor of ERK, and S-phase kinase-associated protein 2 (SKP2)/CDC28 protein kinase 1b (CKS1) ubiquitin ligase complex in human hepatocellular carcinoma (HCC). Levels of DUSP1, as assessed by real-time reverse transcription-PCR and Western blot analysis, were significantly higher in tumors with better prognosis (as defined by the length of patients' survival) when compared with both normal and nontumorous surrounding livers, whereas DUSP1 protein expression sharply declined in all HCC with poorer prognosis. In the latter HCC subtype, DUSP1 inactivation was due to either ERK/SKP2/CKS1-dependent ubiquitination or promoter hypermethylation associated with loss of heterozygosity at the DUSP1 locus. Noticeably, expression levels of DUSP1 inversely correlated with those of activated ERK, as well as with proliferation index and microvessel density, and directly with apoptosis and survival rate. Subsequent functional studies revealed that DUSP1 reactivation led to suppression of ERK, CKS1, and SKP2 activity, inhibition of proliferation and induction of apoptosis in human hepatoma cell lines. Taken together, the present data indicate that ERK achieves unrestrained activity during HCC progression by triggering ubiquitin-mediated proteolysis of its specific inhibitor DUSP1. Thus, DUSP1 may represent a valuable prognostic marker and ERK, CKS1, or SKP2 potential therapeutic targets for human HCC.
Cancer Research 06/2008; 68(11):4192-200. · 7.86 Impact Factor
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Diego F Calvisi,
Maria M Simile,
Sara Ladu,
Rossella Pellegrino,
Valentina De Murtas,
Federico Pinna,
Maria L Tomasi,
Maddalena Frau, Patrizia Virdis,
Maria R De Miglio,
Maria R Muroni,
Rosa M Pascale,
Francesco Feo
[show abstract]
[hide abstract]
ABSTRACT: Mounting evidence underlines the role of genomic hypomethylation in the generation of genomic instability (GI) and tumorigenesis, but whether DNA hypomethylation is required for hepatocellular carcinoma (HCC) development and progression remains unclear. We investigated the correlation between GI and DNA methylation, and influence of methionine metabolism deregulation on these parameters and hepatocarcinogenesis in c-Myc and c-Myc/Tgf-alpha transgenic mice and human HCCs. S-adenosyl-L-methionine/S-adenosylhomocysteine ratio and liver-specific methionine adenosyltransferase (MatI/III) progressively decreased in dysplastic and neoplastic liver lesions developed in c-Myc transgenic mice and in human HCC with better (HCCB) and poorer (HCCP) prognosis (based on patient's survival length). Deregulation of these parameters resulted in a rise of global DNA hypomethylation both in c-Myc and human liver lesions, positively correlated with GI levels in mice and humans, and inversely correlated with the length of survival of HCC patients. No changes in MATI/III and DNA methylation occurred in c-Myc/Tgf-alpha lesions and in a small human HCC subgroup with intermediate prognosis, where a proliferative activity similar to that of c-Myc HCC and HCCB was associated with low apoptosis. Upregulation of genes involved in polyamine synthesis, methionine salvage and downregulation of polyamine negative regulator OAZ1, was highest in c-Myc/Tgf-alpha HCCs and HCCP. Our results indicate that alterations in the activity of MAT/I/III, and extent of DNA hypomethylation and GI are prognostic markers for human HCC. However, a small human HCC subgroup, as c-Myc/Tgf-alpha tumors, may develop in the absence of alterations in DNA methylation.
International Journal of Cancer 01/2008; 121(11):2410-20. · 5.44 Impact Factor
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Maria R De Miglio, Patrizia Virdis,
Diego F Calvisi,
Daniela Mele,
Maria R Muroni,
Maddalena Frau,
Federico Pinna,
Maria L Tomasi,
Maria M Simile,
Rosa M Pascale,
Francesco Feo
[show abstract]
[hide abstract]
ABSTRACT: Sporadic colorectal cancer (CRC) is a major health concern worldwide. Epidemiologic evidence suggests a polygenic predisposition to CRC, but the genes responsible remain unknown. Here, we performed genome-wide scanning of male (ACI/SegHsd x Wistar-Furth)F2 (AWF2) rats to map susceptibility genes influencing the evolution of early colorectal lesions to adenocarcinoma following 1,2-dimethylhydrazine administration. Phenotypic analysis revealed higher incidence/multiplicity and lower size of adenomas in ACI/SegHsd (ACI) and (ACI/SegHsd x Wistar-Furth)F1 (AWF1) than Wistar-Furth (WF) rats and higher incidence/multiplicity of poorly differentiated adenocarcinomas in WF than ACI rats, with intermediate values in AWF1 rats. Linkage analysis of 138 AWF2 rats identified three loci on chromosomes 4, 15 and 18 in significant linkage with lesion multiplicity that were identified as rat Colon cancer resistance (rCcr) 1, rCcr2 and rCcr3, respectively. Seven other loci on chromosomes 5, 6, 15, 17, 18 and 20 were in suggestive linkage with adenoma/adenocarcinoma multiplicity/surface area. Six of them were identified as rCcr4-9 and a locus on chromosome 5 was identified as a susceptibility locus, rCcs1. Significant interactions between rCcr3 and rCcr6, rCcr6 and rCcr8 and rCcr5 and rCcr9, and four novel epistatic loci controlling multiplicity/size of colorectal lesions were discovered. Apc, located at rCcr3, did not show functional promoter polymorphisms. However, influence of susceptibility/resistance genes on Wnt/beta-catenin pathway was shown by defective beta-catenin inactivation in WF but not in ACI and AWF1 rat adenocarcinomas. These data indicate that inheritance of predisposition to CRC depends on interplays of several genetic factors, and suggest a possible mechanism of polygenic control of CRC progression.
Carcinogenesis 12/2007; 28(11):2367-74. · 5.70 Impact Factor
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Maria R De Miglio, Patrizia Virdis,
Diego F Calvisi,
Maddalena Frau,
Maria R Muroni,
Maria M Simile,
Lucia Daino,
Giovanni M Careddu,
Eraldo Sanna-Passino,
Rosa M Pascale,
Francesco Feo
[show abstract]
[hide abstract]
ABSTRACT: Hepatocellular carcinoma (HCC) is prevalent in human and rodent males. Hepatocarcinogenesis is controlled by various genes in susceptible F344 and resistant Brown Norway (BN) rats. B alleles at Hcs4 locus, on RNO16, control neoplastic nodule volume. We constructed the F344.BN-Hcs4 recombinant congenic strain (RCS) by introgressing a 4.41-cM portion of Hcs4 from BN strain in an isogenic F344 background. Preneoplastic and neoplastic lesions were induced by the "resistant hepatocyte" protocol. Eight weeks after initiation, lesion volume and positivity for proliferating cell nuclear antigen (PCNA) were much higher in lesions of F344 than BN rats of both sexes. These variables were lower in females than in males. Lesion volume and PCNA values of male RCS were similar to those of F344 rats, but in females corresponded to those of BN females. Carcinomatous nodules and HCC developed at 32 and 60 weeks, respectively, in male F344 and congenics and, rarely, in F344 females. BN and congenic females developed only eosinophilic/clear cells nodules. Gonadectomy of congenic males, followed by beta-estradiol administration, caused a decrease in Ar expression, an increase in Er-alpha expression, and development of preneoplastic lesions comparable to those from BN females. Administration of testosterone to gonadectomized females led to Ar increase and development of preneoplastic lesions as in F344 males. This indicates a role of homozygous B alleles at Hcs4 in the determination of phenotypic patterns of female RCS and presence at Hcs4 locus of a high penetrance gene(s), activated by estrogens and inhibited/unaffected by testosterone, conferring resistance to females in which the B alleles provide higher resistance.
Cancer Research 12/2006; 66(21):10384-90. · 7.86 Impact Factor
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Maria R De Miglio,
Rosa M Pascale,
Maria M Simile,
Maria R Muroni, Patrizia Virdis,
Kelvin M-T Kwong,
Leslie K L Wong,
Giovanni M Bosinco,
Franca R Pulina,
Diego F Calvisi,
Maddalena Frau,
Geoffrey A Wood,
Michael C Archer,
Francesco Feo
[show abstract]
[hide abstract]
ABSTRACT: Cop and CFF1 rats exhibit resistance to hepatocarcinogenesis, associated with high rates of remodeling of neoplastic lesions. We have mapped hepatocarcinogenesis susceptibility, resistance and remodeling loci affecting the number, volume and volume fraction of neoplastic nodules induced by the "resistant hepatocyte" model in male CFF2 rats. Three loci in significant linkage with the number or volume of nonremodeling lesions were identified on chromosomes 1, 4 and 18. Suggestive linkage with number or volume fraction of total, nonremodeling or remodeling lesions was found for 7 loci on chromosomes 1, 2, 13, 14 and 15. All of these loci showed significant allele-specific effects on the phenotypic traits. We also detected by analysis of variance 19 2-way interactions inducing phenotypic effects not predictable on the basis of the sum of separate effects. These novel epistatic loci were in significant linkage with the number and/or volume of total, nonremodeling or remodeling nodules. These data indicate that susceptibility to hepatocarcinogenesis in Cop rats is controlled by a complex array of genes with several gene-gene interactions and that different genetic mechanisms control remodeling and nonremodeling liver nodules. Frequent deregulation in human liver cancer of genes positioned in chromosomal segments syntenic to rat susceptibility/resistance loci suggests some similarities between the genetic mechanisms involved in hepatocarcinogenesis in rats and humans.
International Journal of Cancer 09/2004; 111(1):9-16. · 5.44 Impact Factor
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Maria R De Miglio,
Maria M Simile,
Maria R Muroni,
Diego F Calvisi, Patrizia Virdis,
Giuseppina Asara,
Maddalena Frau,
Giovanni M Bosinco,
Maria A Seddaiu,
Lucia Daino,
Francesco Feo,
Rosa M Pascale
[show abstract]
[hide abstract]
ABSTRACT: Low DNA synthesis and high redifferentiation (remodeling) characterize neoplastic nodules induced by chemical carcinogens in hybrid BFF1 rats, generated by crossing the susceptible F344 and resistant BN strains. We performed whole-genome scanning of BFF2 rats to identify loci controlling remodeling of nodules induced, 32 weeks after initiation with diethylnitrosamine, by the RH protocol. Remodeling nodules were identified as areas lacking uniformity of GST-P immunostaining and with irregular margins. Two loci in suggestive linkage with the percentage of remodeling nodules were identified on chromosomes 7 and 1 (LOD scores 3.85 and 2.9 at D7Rat25 and D1Mgh14). Significant dosage-negative effect of the B allele on remodeling and additive interaction between these loci were found. Significant epistatic interactions, showing a recessive, remodeling-enhancing effect of B alleles, occurred between D1Mit3 and D11Rat11 (corrected p = 0.0013) and between D6Rat14 and D8Rat46 (corrected p = 0.028). These data show that remodeling of neoplastic nodules during rat hepatocarcinogenesis is under genetic control. Loci affecting remodeling map to chromosomal regions syntenic to chromosomal segments of human HCC showing structural abnormalities.
International Journal of Cancer 06/2003; 105(1):70-5. · 5.44 Impact Factor
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Maria R De Miglio,
Rosa M Pascale,
Maria M Simile,
Maria R Muroni,
Diego F Calvisi, Patrizia Virdis,
Giovanni M Bosinco,
Maddalena Frau,
Maria A Seddaiu,
Sara Ladu,
Francesco Feo
[show abstract]
[hide abstract]
ABSTRACT: Previous studies on (BNxF344)F1 (BFF1) rat model of genetic predisposition to hepatocarcinogenesis led to the identification, in BFF1xF344 backcross progeny, of two hepatocarcinogenesis susceptibility (Hcs) and three resistance (Hcr) loci affecting the progression of neoplastic liver nodules. To evaluate the presence of other hepatocarcinogenesis-related loci in the BFF1 genome, nodule induction by resistant hepatocyte model in 116 male BFF2 rats 32 weeks after initiation with diethylnitrosamine was subjected to quantitative trait loci analysis. The rats were typed with 179 genetic markers, and linkage analysis identified three loci on chromosomes 1, 16, and 6, in significant linkage with nodule mean volume (V), volume fraction, and number, respectively, and two loci on chromosomes 4 and 8 in suggestive linkage with V. These loci were differently positioned with respect to Hcs and Hcr loci mapped previously in backcross rats. On the basis of phenotypic and allele distribution patterns of BFF2 rats, loci on chromosomes 1 and 16 were identified as Hcs3 and Hcs4, and loci on chromosomes 4, 8, and 6 as Hcr4, Hcr5, and Hcr6. Additive interactions occurred between Hcs3 and Hcs4, and Hcr4 and a locus on chromosome 3 with less than suggestive linkage with V. All of the loci were in chromosomal regions syntenic to mouse and/or human chromosomal segments showing allelic gain or loss in hepatocellular carcinomas. These data indicate that inheritance of predisposition to rat liver tumor is characterized by the interplay of several genetic factors and suggest some possible mechanisms of polygenic control of human liver cancer.
Cancer Research 09/2002; 62(15):4459-63. · 7.86 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Objective . Immune dysregulation plays a role in the pathophysiology of myelodysplastic syndromes (MDS), as T-cell clones seem to be involved in the inhibition of hematopoietic precursors. The purpose of this study was to analyze the T-cell receptor (TCR) repertoire of MDS patients, focusing on the third complementarity determining region (CDR3) pattern of their CD4<sup>+</sup> and CD8<sup>+</sup> lymphocyte expansions.
Materials and Methods . The study involved 30 patients and 15 age-matched controls. The β-variable (βV) subfamily flow-cytometry analysis was performed on peripheral CD4<sup>+</sup> and CD8<sup>+</sup> T-cells. Spectratyping TCR-CDR3 analysis was carried out on isolated helper and cytotoxic T lymphocytes after immunomagnetic separation and reverse-transcriptase polymerase chain reaction.
Results . We first identified by flow cytometry an increased frequency of expanded βVs in both CD4<sup>+</sup> and CD8<sup>+</sup> T-cells in MDS patients. We then showed, by spectratyping, that the CDR3 profile was mostly Gaussian in their CD4<sup>+</sup> T cells, whereas CD8<sup>+</sup> T cells usually showed skewed or oligoclonal CDR3 regions. When we compared spectratyping and flow-cytometry findings in each patient, we showed that most CD4<sup>+</sup> lymphocyte expansions detected by flow cytometry had Gaussian CDR3 profiles, whereas most CD8<sup>+</sup> expansions were oligoclonal.
Conclusion . We confirm that in MDS patients the TCR-βV repertoire is overall extremely contracted, especially in cytotoxic T cells. This pattern is mainly determined by selective proliferations of both helper and cytotoxic T cells, which are, however, mostly polyclonal in the former and oligoclonal in the latter. Such a difference, possibly related to the different human leukocyte antigen restriction, could reflect the selective involvement of cytotoxic T cells either in the anti-tumor immune surveillance or in an autoreactive aggression toward hematopoietic precursors.
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[show abstract]
[hide abstract]
ABSTRACT: Background and Aims: Genomic instability (GI) is involved in rodent and
human hepatocellular carcinoma (HCC) pathogenesis. DNA hypomethylation
may drive malignant transformation by generating GI, but whether
DNA hypomethylation is a prerequisite for HCC development remains
unclear. We investigated the correlation between GI and DNA methylation,
and influence of methionine metabolism deregulation on these parameters
in c-Myc and c-Myc/Tgf-a transgenic mouse models of HCC.
Methods: S-adenosylmethionine (SAM) and S-adenosylhomocysteine
(SAH) liver content was assessed by HPLC, activity of methionine
adenosyltransferases by enzymatic assay, levels of methionine metabolism
regulators by RT-PCR, GI by RAPD, and global DNA methylation by
[<sup>3 </sup>H]dCTP incorporation into DNA.
Results: SAMiSAH ratio and liver-specific methionine adenosyltransferase
levels progressively decreased in dysplastic and neoplastic liver of
c-Myc transgenic mice, leading to global DNA hypomethylation and GI,
but not in c-Myc/Tgf-cc lesions, where highest GI correlated with proliferative
activity. Upregulation of genes involved in polyamine synthesis,
methionine salvage, and downregulation of polyamine negative regulator
OAZl, was highest in c-MyciTgf-a HCCs, indicating SAM requirement
for polyamine-induced growth in aggressive c-MyciTgf-a HCCs.
Conclusions: Our results indicate that aggressive HCC may develop in the
absence of DNA hypomethylation. Genome-wide hypomethylation may
favor development of slow growing HCC with relatively low GI and
polyamine synthesis.
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Maria Rosaria De Miglio, Patrizia Virdis,
Diego Francesco Calvisi,
Daniela Mele,
Maria Rosaria Muroni,
Maddalena Frau,
Federico Pinna,
Maria Lauda Tomasi,
Maria Maddalena Simile,
Rosa Maria Pascale,
Francesco Feo
[show abstract]
[hide abstract]
ABSTRACT: Sporadic colorectal cancer (CRC) is a major health concern worldwide.<SUP> </SUP>Epidemiologic evidence suggests a polygenic predisposition to<SUP> </SUP>CRC, but the genes responsible remain unknown. Here, we performed<SUP> </SUP>genome-wide scanning of male (ACI/SegHsd x Wistar-Furth)F2 (AWF2)<SUP> </SUP>rats to map susceptibility genes influencing the evolution of<SUP> </SUP>early colorectal lesions to adenocarcinoma following 1,2-dimethylhydrazine<SUP> </SUP>administration. Phenotypic analysis revealed higher incidence/multiplicity<SUP> </SUP>and lower size of adenomas in ACI/SegHsd (ACI) and (ACI/SegHsd<SUP> </SUP> x Wistar-Furth)F1 (AWF1) than Wistar-Furth (WF) rats and higher<SUP> </SUP>incidence/multiplicity of poorly differentiated adenocarcinomas<SUP> </SUP>in WF than ACI rats, with intermediate values in AWF1 rats.<SUP> </SUP>Linkage analysis of 138 AWF2 rats identified three loci on chromosomes<SUP> </SUP>4, 15 and 18 in significant linkage with lesion multiplicity<SUP> </SUP>that were identified as rat Colon cancer resistance ( rCcr ) 1,<SUP> </SUP> rCcr2 and rCcr3 , respectively. Seven other loci on chromosomes<SUP> </SUP>5, 6, 15, 17, 18 and 20 were in suggestive linkage with adenoma/adenocarcinoma<SUP> </SUP>multiplicity/surface area. Six of them were identified as rCcr4 – 9 <SUP> </SUP>and a locus on chromosome 5 was identified as a susceptibility<SUP> </SUP>locus, rCcs1 . Significant interactions between rCcr3 and rCcr6 ,<SUP> </SUP> rCcr6 and rCcr8 and rCcr5 and rCcr9 , and four novel epistatic<SUP> </SUP>loci controlling multiplicity/size of colorectal lesions were<SUP> </SUP>discovered. Apc , located at rCcr3 , did not show functional promoter<SUP> </SUP>polymorphisms. However, influence of susceptibility/resistance<SUP> </SUP>genes on Wnt/ß-catenin pathway was shown by defective<SUP> </SUP>ß-catenin inactivation in WF but not in ACI and AWF1<SUP> </SUP>rat adenocarcinomas. These data indicate that inheritance of<SUP> </SUP>predisposition to CRC depends on interplays of several genetic<SUP> </SUP>factors, and suggest a possible mechanism of polygenic control<SUP> </SUP>of CRC progression.
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Maria Rosaria De Miglio,
Rosa Maria Pascale,
Maria Maddalena Simile,
Maria Rosaria Muroni,
Diego Francesco Calvisi, Patrizia Virdis,
Giovanni M. Bosinco,
Maddalena Frau,
Maria Antonietta Seddaiu,
Sara Ladu,
Francesco Feo
[show abstract]
[hide abstract]
ABSTRACT: Previous studies on (BNxF344)F1 (BFF1) rat model of genetic predisposition to hepatocarcinogenesisled to the identification,
in BFF1xF344 backcross progeny, of two hepatocarcinogenesis susceptibility ( Hcs ) and three resistance ( Hcr ) loci affecting the progression of neoplastic liver nodules. To evaluate the presence of other hepatocarcinogenesis-related
loci in the BFF1 genome, nodule induction by resistant hepatocyte model in 116 male BFF2 rats 32 weeks after initiation with
diethylnitrosamine was subjected to quantitative trait loci analysis. The rats were typed with 179 genetic markers, and linkage
analysis identified three loci on chromosomes 1, 16, and 6, in significant linkage with nodule mean volume (V), volume fraction,
and number, respectively, and two loci on chromosomes 4 and 8 in suggestive linkage with V. These loci were differently positioned
with respect to Hcs and Hcr loci mapped previously in backcross rats. On the basis of phenotypic and allele distribution patterns of BFF2 rats, loci
on chromosomes 1 and 16 were identified as Hcs3 and Hcs4 , and loci on chromosomes 4, 8, and 6 as Hcr4, Hcr5 , and Hcr6. Additive interactions occurred between Hcs3 and Hcs4 , and Hcr4 and a locus on chromosome 3 with less than suggestive linkage with V. All of the loci were in chromosomal regions syntenic
to mouse and/or human chromosomal segments showing allelic gain or loss in hepatocellular carcinomas. These data indicate
that inheritance of predisposition to rat liver tumor is characterized by the interplay of several genetic factors and suggest
some possible mechanisms of polygenic control of human liver cancer.
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[show abstract]
[hide abstract]
ABSTRACT: Hepatocarcinogenesis sensitivity ( Hcs1, 2 ) and resistance ( Hcr1-3 ) loci have been identified by linkage analysis on rat chromosomes 7 and 1, and 10, 4, and 8, respectively. Cytogenetic studies documented deletions on chromosomes 3 and 6 of neoplastic rat hepatocytes. Hepatocellular carcinomas (HCCs) were produced in F1 hybrid rats between Long-Evans (LE) and Fisher 344 (F344) rats. Scanning of the above chromosomes for loss of heterozygosity (LOH) showed allelic imbalance (AI) at multiple regions on chromosomes 6, 7, and 10q. Detailed deletion mapping of chromosome 10 localized a putative suppressor Hcr1 gene to within a 3.2-cM interval flanked by D10Rat51 and D10Rat121 . Two other distinct regions with frequent AIs were found inside the Hcr1 locus, at marker loci including DNaseI and Mrp genes, and in a segment including 4 consecutive markers ( D10Rat64 , D10Rat182 , D10Rat113 , D10Rat216 ). In 40% of HCCs, AI was seen at the p53 locus. AI on chromosome 7 occurred at the Hcs1 locus, where is located c-myc, which is amplified in HCCs, suggesting allelic gain. Most AIs occurred in poorly/moderately differentiated carcinomas, and a few events were seen in well-differentiated tumors on chromosomes 7 and 10. These data suggest that alteration of a cluster of oncosuppressor genes on 10q is important for HCC progression. The existence of AI on segments of rat chromosomes 6, 7, and 10, syntenic to chromosomal segments of human HCCs where chromosomal gains or deletions occur, suggests a commonalty of some molecular events in the pathogenesis of HCCs in rats and humans. Our map provides information toward cloning putative oncosuppressor genes associated with this carcinoma.
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Maria Rosaria De Miglio,
Maria Maddalena Simile,
Maria Rosaria Muroni,
Diego Francesco Calvisi, Patrizia Virdis,
Giuseppina Asara,
Maddalena Frau,
Giovanni M. Bosinco,
Maria Antonietta Seddaiu,
Lucia Daino,
Francesco Feo,
Rosa Maria Pascale
[show abstract]
[hide abstract]
ABSTRACT: Low DNA synthesis and high redifferentiation (remodeling) characterize neoplastic nodules induced by chemical carcinogens in hybrid BFF1 rats, generated by crossing the susceptible F344 and resistant BN strains. We performed whole-genome scanning of BFF2 rats to identify loci controlling remodeling of nodules induced, 32 weeks after initiation with diethylnitrosamine, by the RH protocol. Remodeling nodules were identified as areas lacking uniformity of GST-P immunostaining and with irregular margins. Two loci in suggestive linkage with the percentage of remodeling nodules were identified on chromosomes 7 and 1 (LOD scores 3.85 and 2.9 at D7Rat25 and D1Mgh14 ). Significant dosage-negative effect of the B allele on remodeling and additive interaction between these loci were found. Significant epistatic interactions, showing a recessive, remodeling-enhancing effect of B alleles, occurred between D1Mit3 and D11Rat11 (corrected p = 0.0013) and between D6Rat14 and D8Rat46 (corrected p = 0.028). These data show that remodeling of neoplastic nodules during rat hepatocarcinogenesis is under genetic control. Loci affecting remodeling map to chromosomal regions syntenic to chromosomal segments of human HCC showing structural abnormalities.
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Maria Rosaria De Miglio,
Rosa Maria Pascale,
Maria Maddalena Simile,
Maria Rosaria Muroni, Patrizia Virdis,
Kelvin M.-T. Kwong,
Leslie K.L. Wong,
Giovanni M. Bosinco,
Franca Rossana Pulina,
Diego Francesco Calvisi,
Maddalena Frau,
Geoffrey A Wood,
Michael C Archer,
Francesco Feo
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ABSTRACT: Cop and CFF1 rats exhibit resistance to hepatocarcinogenesis, associated with high rates of remodeling of neoplastic lesions. We have mapped hepatocarcinogenesis susceptibility, resistance and remodeling loci affecting the number, volume and volume fraction of neoplastic nodules induced by the resistant hepatocyte model in male CFF2 rats. Three loci in significant linkage with the number or volume of nonremodeling lesions were identified on chromosomes 1, 4 and 18. Suggestive linkage with number or volume fraction of total, nonremodeling or remodeling lesions was found for 7 loci on chromosomes 1, 2, 13, 14 and 15. All of these loci showed significant allele-specific effects on the phenotypic traits. We also detected by analysis of variance 19 2-way interactions inducing phenotypic effects not predictable on the basis of the sum of separate effects. These novel epistatic loci were in significant linkage with the number and/or volume of total, nonremodeling or remodeling nodules. These data indicate that susceptibility to hepatocarcinogenesis in Cop rats is controlled by a complex array of genes with several gene-gene interactions and that different genetic mechanisms control remodeling and nonremodeling liver nodules. Frequent deregulation in human liver cancer of genes positioned in chromosomal segments syntenic to rat susceptibility/resistance loci suggests some similarities between the genetic mechanisms involved in hepatocarcinogenesis in rats and humans.
