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Biomedical subjects

C M Croce

Publications and source records attributed to C M Croce.

At least 37 records · Page 2Linked to original sources

FHIT gene therapy prevents tumor development in Fhit-deficient mice.

The tumor suppressor gene FHIT spans a common fragile site and is highly susceptible to environmental carcinogens. FHIT inactivation and loss of expression is found in a large fraction of premaligant and malignant lesions. In this study, we were able to inhibit tumor development by oral gene transfer, using adenoviral or adenoassociated viral vectors expressing the human FHIT gene, in heterozygous Fhit(+/-) knockout mice, that are prone to tumor development after carcinogen exposure. We therefore suggest that FHIT gene therapy could be a novel clinical approach not only in treatment of early stages of cancer, but also in prevention of human cancer.

Acid Anhydride Hydrolases↗

Upregulation of Meis1 and HoxA9 in acute lymphocytic leukemias with the t(4 : 11) abnormality.

Rearrangements of the human ALL-1 gene are frequently encountered in acute lymphocytic leukemias (ALL) and acute myeloid leukemias (AML). These rearrangements are mostly due to chromosome translocations and result in production of chimeric proteins composed of the N-terminal fragment of ALL-1 and the C-terminal segments of the partner proteins. The most common chromosome translocation involving ALL-1 is the t(4 : 11) associated with ALL. ALL-1 is the human homologue of Drosophila trithorax and directly activates transcription of multiple Hox genes. A preliminary DNA microarray screen indicated that the Meis1, HoxA9 and AC133 genes were overexpressed in ALLs with t(4 : 11), compared to ALLs with very similar phenotype but without the chromosomal abnormality. These genes, as well as additional five Hox genes, were subjected to comprehensive semi-quantitative or quantitative RT-PCR analysis in 57 primary ALL and AML tumors. Meis1 and HoxA9 were found expressed in 13/14 of ALLs with the t(4 : 11) and in 8/8 of AMLs with ALL-1 rearrangements. The two genes were not consistently transcribed in other types of ALL. AC133 was transcribed in 13/14 of ALLs with t(4 : 11), but in only 4/8 of AMLs with ALL-1 rearrangements. HoxA10 was expressed in most leukemias with ALL-1 alterations, but was also transcribed in PrePreB CD10(-) ALLs lacking the t(4 : 11). Expression of HoxA5, HoxA7, HoxC8 and HoxC10 did not correlate with ALL-1 rearrangements. Coexpression of Meis1 and HoxA9, overexpression of HoxA10, and overexpression or fusion of HoxA9 were previously implicated in certain acute myeloid leukemias in mice and humans. The present work suggests that upregulation of Meis1, HoxA9, and possibly HoxA10 might also play a role in pathogenesis of acute lymphocytic and acute myeloid leukemias associated with ALL-1 fusions.

Chromosome Aberrations↗

Effect of adenoviral transduction of the fragile histidine triad gene into esophageal cancer cells.

Reintroduction of a tumor suppressor gene product in cancer cells is a promising strategy for cancer gene therapy. The fragile histidine triad (FHIT) gene has been identified in a region at chromosome 3p14.2, which is deleted in many tumors, including esophageal cancer. Previous studies have shown frequent biallelic alterations of the FHIT gene in numerous tumors, and have demonstrated a tumor suppressor function of Fhit. We have studied the biological effects of adenoviral-FHIT transduction in esophageal cancer cell lines. Results showed suppression of cell growth in vitro in three of seven esophageal cancer cell lines, all seven of which showed abundant expression of the transgene. Adenoviral-FHIT expression, but not control adenoviral infections, induced caspase-dependent apoptosis in two esophageal cancer cell lines, TE14 and TE4, which express no or very little Fhit, respectively. Treatment of TE14 cells with adenoviral-FHIT vectors resulted in abrogation of tumorigenicity in nude mice. A third esophageal cancer cell line, TE12, without detectable endogenous Fhit, showed accumulation of cells at S to G2-M and a small apoptotic cell fraction after adenoviral-FHIT transduction. Thus, adenoviral-FHIT expression can inhibit the growth of esophageal cancer cells, at least in part through caspase-dependent apoptosis, suggesting that adenoviral-FHIT infection should be explored as a therapeutic strategy.

Acid Anhydride Hydrolases↗

FRA3B and other common fragile sites: the weakest links.

In 1979, the first chromosome alteration associated with familial cancer was reported. Five years later, a fragile site was observed in the same chromosome region. The product of the fragile histidine triad (FHIT) gene, which encompasses this fragile site, is partially or entirely lost in most human cancers, indicating that it has a tumour-suppressor function. Inactivation of only one FHIT allele compromises this suppressor function, indicating that a 'one-hit' mechanism of tumorigenesis is operative. Are genes disrupted at other fragile sites? And, are these genes also tumour suppressors?

Acid Anhydride Hydrolases↗

Role of the high mobility group A proteins in human lipomas.

The HMGA family is comprised of four proteins: HMGA1a, HMGA1b, HMGA1c and HMGA2. The first three proteins are products of the same gene, HMGA1, generated through an alternative splicing mechanism. The HMGA proteins are involved in the regulation of chromatin structure and HMGA DNA-binding sites have been identified in functional regions of many gene promoters. Rearrangements of the HMGA2 gene have been frequently detected in human benign tumors of mesenchymal origin including lipomas. 12q13-15 chromosomal translocations involving the HMGA2 gene locus, account for these rearrangements. The HMGA proteins have three AT-hook domains and an acidic C-terminal tail. The HMGA2 modifications consist in the loss of the C-terminal tail and fusion with ectopic sequences. A pivotal role of the HMGA2 rearrangements in the process of lipomagenesis is suggested by experiments showing that transgenic mice carrying a truncated HMGA2 gene showed a giant phenotype together with abdominal/pelvic lipomatosis. As HMGA2 null mice showed a great reduction in fat tissue, a positive role of the HMGA2 gene in adipocytic cell proliferation is proposed. More recently, similar alterations of the HMGA1 gene have been described. As the block of the HMGA1 protein synthesis induces an increase in growth rate of the pre-adipocytic cell line 3T3-L1, we suggest a negative role of the HMGA1 proteins in adipocytic cell growth and, therefore, we propose that adipocytic cell growth derives from the balance of the HMGA1 and HMGA2 protein functions.

Adipocytes↗

Critical role of the HMGI(Y) proteins in adipocytic cell growth and differentiation.

The high-mobility group I (HMGI) nonhistone chromosomal proteins HMGI(Y) and HMGI-C have been implicated in defining chromatin structure and in regulating the transcription of several genes. These proteins have been implicated in adipocyte homeostasis: a severe deficiency of fat tissue is found in mice with targeted disruption of the HMGI-C locus, and lipomagenesis in humans is frequently associated with somatic mutations of HMGI genes. The aim of this study was to examine the role of HMGI(Y) proteins in adipocytic cell growth and differentiation. First, we found that differentiation of the preadipocytic 3T3-L1 cell line caused early induction of HMGI(Y) gene expression. Suppression of HMGI(Y) expression by antisense technology dramatically increased the growth rate and impaired adipocytic differentiation in these cells. The process of adipogenic differentiation involves the interplay of several transcription factors, among which is the CCAAT/enhancer-binding protein (C/EBP) family of proteins. These factors are required for the transcriptional activation of adipocyte-specific genes. We also tested the hypothesis that HMGI(Y) might participate in transcriptional control of adipocyte-specific promoters. We found that HMGI(Y) proteins bind C/EBPbeta in vivo and in vitro. Furthermore, we show that HMGI(Y) strongly potentiates the capacity of C/EBPbeta to transactivate the leptin promoter, an adipose-specific promoter. Taken together, these results indicate that the HMGI(Y) proteins play a critical role in adipocytic cell growth and differentiation.

3T3 Cells↗

Expression of TCL1 in hematologic disorders.

OBJECTIVE: TCL1, MTCP1 and TCL1b are three members of a new family of oncogenes that are expressed in T cell leukemias of ataxia telangiectasia patients (T-PLL, T-CLL). TCL1 is located at 14q32.1 and activated by juxtaposition to the alpha/delta-locus at 14q11 or beta-locus at 7q35 of the T cell receptor during the reciprocal translocations t(14;14)(q11;q32), t(7;14)(q35;q32), or inversion inv(14)(q11;q32). TCL1 encodes a predominantly cytoplasmic protein of 114 aa (14 kD) of unknown function. Recent studies suggest that TCL1 promotes cell survival rather than stimulating cell proliferation, as previously proposed. METHODS: In an attempt to clarify the contexts in which TCL1 is expressed, we investigated TCL1 expression in 114 lymphoma and leukemia patients by Northern blot, RT-PCR and immunohistochemistry. RESULTS: TCL1 expression is restricted to lymphoid cells, and is found in neoplastic (T and B cell neoplasms, and Hodgkin's disease) and nonneoplastic proliferations (reactive lesions). Out of 114 cases, 18 neoplasms of myeloid and 4 cases of epithelial origin were TCL1-negative. In lesions of the lymphoid system, both low- and high-grade lymphomas were found to express TCL1. CONCLUSIONS: We propose that TCL1 expression especially in high-grade B cell non-Hodgkin's lymphomas might interfere with B cell differentiation and promote the transition from low- to high-grade lymphoma.

Blotting, Northern↗

Cervical dysplasia, ploidy, and human papillomavirus status correlate with loss of Fhit expression.

PURPOSE: The tumor suppressor gene, FHIT, has been cloned and mapped at chromosome region 3p14.2, one of the regions most frequently deleted in cervical carcinoma. In this report, we show that the expression of the Fhit protein in relation to human papillomavirus (HPV) subtype, the type of the intraepithelial lesion, HIV-induced immunodeficiency, and the DNA content (ploidy) correlates with the biological behavior of the lesions. EXPERIMENTAL DESIGN: To investigate involvement of the FHIT gene in squamous intraepithelial lesions of low and high grade (LGSILs and HGSILs, respectively) of the uterine cervix, we examined the Fhit protein expression by immunocytochemistry in 131 cervical smears of 96 HIV-seropositive patients (42 with LGSILs and 10 with HGSILs) and 35 HIV-seronegative (5 with LGSILs) persons. RESULTS: Fhit protein was detected in normal cells, whereas dysplastic cells (independently of HPV infection and HPV subtypes) showed reduced expression of Fhit (P = 0.00001). Lesions from 52 HIV-seropositive patients, 42 LGSILs and 10 HGSILs, showed diploid DNA content in 63.5%, aneuploid in 32.7%, and polyploid in 3.8%, but 90% of the HGSILs showed an aneuploid DNA content, and all were infected by HPV 16/18 subtypes. 23.8% of LGSIL cases were associated with HPV 16. CONCLUSIONS: These data clearly suggest that loss of Fhit expression occurs in the early stages of cervical carcinogenesis. Pap test represents one of the most convenient and rapid procedures available in identification of cellular changes; hence, Fhit staining might be used as an useful tool in larger population screening to detect early alteration in cellular behaviors.

Acid Anhydride Hydrolases↗

Fez1/lzts1 alterations in gastric carcinoma.

PURPOSE: Loss of heterozygosity (LOH) involving the short arm of chromosome 8 (8p) is a common feature of the malignant progression of human tumors, including gastric cancer. We have cloned and mapped a candidate tumor suppressor gene, FEZ1/LZTS1, to 8p22. Here we have analyzed whether FEZ1/LZTS1 alterations play a role in the development and progression of gastric carcinoma. EXPERIMENTAL DESIGN: We examined Fez1/Lzts1 expression in 8 gastric carcinoma cell lines by Western blot, and in 88 primary gastric carcinomas by immunohistochemistry. Twenty-six of these 88 primary gastric carcinomas were also microdissected and tested for LOH at the FEZ1/LZTS1 locus and for mutation of the FEZ1/LZTS1 gene. Furthermore, we studied the FEZ1/LZTS1 gene regulation and transcriptional control and the methylation status of the 5' region of the gene in all 8 gastric carcinoma cell lines. RESULTS: Fez1/Lzts1 protein was barely detectable in all of the gastric cancer cell lines tested and was absent or significantly reduced in 39 of the 88 (44.3%) gastric carcinomas analyzed by immunohistochemistry, with a significant correlation (P < 0.001) to diffuse histotype. DNA allelotyping analysis showed allelic loss in 3 of 17 (18%) and microsatellite instability in 4 of 17 (23.5%) cases informative for D8S261 at the FEZ1/LZTS1 locus. When we compared the presence of LOH with Fez1/Lzts1 expression, we found loss of protein expression in all three of the tumors with allelic imbalance at D8S261. A missense mutation was detected in one case that did not express Fez1/Lzts1. Hypermethylation of the CpG island flanking the Fez1/Lzts1 promoter was evident in six of the eight cell lines examined as well as in the normal control. CONCLUSIONS: Our findings support FEZ1/LZTS1 as a candidate tumor suppressor gene at 8p in a subtype of gastric cancer and suggest that its inactivation is attributable to several factors including genomic deletion and methylation.

Adaptor Proteins, Signal Transducing↗

Expression of Fhit protein during mouse development.

Fhit protein has a putative tumor suppressor function in several types of human and experimental cancers. To assess whether Fhit is involved in fetal development we have examined the distribution of Fhit protein in the 12- through 16-day postcoitum mouse fetus and in postnatal day 0 mouse pups by immunocytochemistry. High levels of Fhit protein were observed in the endodermal derivatives, namely, bronchi, trachea, esophagus, stomach, and intestine, in the 12- to 16-day postcoitum mouse fetus and in the postnatal day 0 pup. Other tissues showed a more restricted pattern of Fhit protein expression. These results suggest that Fhit may play a role in the development of specific tissues during mouse development.

Acid Anhydride Hydrolases↗

Characterization of the human TESTIN gene localized in the FRA7G region at 7q31.2.

Cancer-associated chromosomal aberrations often involve regions containing fragile sites. FRA7G is a common aphidicolin-inducible fragile site at 7q31.2, showing loss of heterozygosity in human malignancies. To investigate the structure of FRA7G, we constructed a bacterial artificial chromosome contig spanning the region between marker D7S486 and Met H. Analysis of the FRA7G sequence allowed us to identify a gene encoding a 421-amino-acid protein with three LIM domains and 89% identity to murine Testin. We determined the genomic structure of the human TESTIN locus and characterized three alternative transcripts. Although TESTIN mRNA is expressed in all normal human tissues examined, we observed lack of expression in 22% of cancer cell lines and 44% of the cell lines derived from hematological malignancies. We further determined that in most of these cases the inactivation of TESTIN expression is due to methylation of a CpG island. Analysis of the TESTIN coding region in 26 tumor cell lines revealed three missense mutations. Our findings suggest that TESTIN may represent a candidate tumor suppressor gene at 7q31.2.

Amino Acid Sequence↗

A novel zinc finger gene is fused to EWS in small round cell tumor.

Ewing sarcoma family of tumors share recurrent translocations that fuse EWS from 22q12 to five different members of transcription factors namely FLI-1, ERG, ETV1, E1AF and FEV. Different classes of DNA binding proteins, ATF1, WT1 and CHOP are fused to EWS generating distinct tumor phenotypes: clear cell sarcoma, desmoplastic small round cell tumor, and myxoid liposarcoma, respectively. We have cloned a novel gene located at 22q12 fused to EWS by a submicroscopic inversion of 22q in a small round cell sarcoma showing a translocation (t(1;22)(p36.1;q12). The gene, designated ZSG (Zinc finger Sarcoma Gene), is a putative Cys2-His2 zinc finger protein which contains a POZ transcriptional repressor-like domain at the N-terminus. The rearrangement involves intron 8 of EWS and exon 1 of ZSG creating a chimeric sequence containing the transactivation domain of EWS fused to zinc finger domain of ZSG. This product lacks the transcriptional repressor domain at the N-terminus of ZSG. A rearrangement of the second ZSG allele was also found in tumor cells. This is the first example of an intra-chromosomal rearrangement of chromosome 22, undetectable by cytogenetics, activating EWS in soft tissue sarcoma.

Adolescent↗

Structure-based discovery of an organic compound that binds Bcl-2 protein and induces apoptosis of tumor cells.

Bcl-2 and related proteins are key regulators of apoptosis or programmed cell death implicated in human disease including cancer. We recently showed that cell-permeable Bcl-2 binding peptides could induce apoptosis of human myeloid leukemia in vitro and suppress its growth in severe combined immunodeficient mice. Here we report the discovery of HA14-1, a small molecule (molecular weight = 409) and nonpeptidic ligand of a Bcl-2 surface pocket, by using a computer screening strategy based on the predicted structure of Bcl-2 protein. In vitro binding studies demonstrated the interaction of HA14-1 with this Bcl-2 surface pocket that is essential for Bcl-2 biological function. HA14-1 effectively induced apoptosis of human acute myeloid leukemia (HL-60) cells overexpressing Bcl-2 protein that was associated with the decrease in mitochondrial membrane potential and activation of caspase-9 followed by caspase-3. Cytokine response modifier A, a potent inhibitor of Fas-mediated apoptosis, did not block apoptosis induced by HA14-1. Whereas HA14-1 strongly induced the death of NIH 3T3 (Apaf-1(+/+)) cells, it had little apoptotic effect on Apaf-1-deficient (Apaf-1(-/-)) mouse embryonic fibroblast cells. These data are consistent with a mechanism by which HA14-1 induces the activation of Apaf-1 and caspases, possibly by binding to Bcl-2 protein and inhibiting its function. The discovery of this cell-permeable molecule provides a chemical probe to study Bcl-2-regulated apoptotic pathways in vivo and could lead to the development of new therapeutic agents.

Animals↗

huASH1 protein, a putative transcription factor encoded by a human homologue of the Drosophila ash1 gene, localizes to both nuclei and cell-cell tight junctions.

During animal development, regions of the embryo become committed to position-specific identities, which are determined by spatially restricted expression of Hox/homeotic genes. This expression pattern is initially established by the activity of the segmentation genes and is subsequently maintained during the proliferative stage through the action of transcription factors encoded by the trithorax (trx) and Polycomb (Pc) groups of genes. trithorax (trx)and ash1 (absent, small, or homeotic 1) are members of the Drosophila trx group. Their products are associated with chromosomes and are believed to activate transcription of target genes through chromatin remodeling. Recently, we reported molecular studies indicating that TRX and ASH1 proteins act in concert to bind simultaneously to response elements located at close proximity within the same set of target genes. Extension of these and other studies to mammalian systems required identification and cloning of the mammalian homologue of ash1 (the mammalian homologue of trx, ALL-1, was previously cloned). We have identified a human expressed sequence tag (EST) clone with similarity to the SET domain of Drosophila ASH1, and used it to clone the human gene. huASH1 resides at chromosomal band 1q21. The gene is expressed in multiple tissues as an approximately 10.5-kb transcript and encodes a protein of 2962 residues. The protein contains a SET domain, a PHD finger, four AT hooks, and a region with homology to the bromodomain. The last region is not present in Drosophila ASH1, and as such might confer to the human protein a unique additional function. Using several anti-huASH1 Ab for immunostaining of cultured cells, we found that the protein is distributed in intranuclear speckles, and unexpectedly also in intercellular junctions. Double-immunofluorescence labeling of huASH1 and several junctional proteins localized the huASH1 protein into tight junctions. The significance of huASH1 dual location is discussed. In particular, we consider the possibility that translocation of the protein between the junctional membrane and the nucleus may be involved in adhesion-mediated signaling.

Amino Acid Sequence↗

Gain of imprinting at chromosome 11p15: A pathogenetic mechanism identified in human hepatocarcinomas.

Genomic imprinting is a reversible condition that causes parental-specific silencing of maternally or paternally inherited genes. Analysis of DNA and RNA from 52 human hepatocarcinoma samples revealed abnormal imprinting of genes located at chromosome 11p15 in 51% of 37 informative samples. The most frequently detected abnormality was gain of imprinting, which led to loss of expression of genes present on the maternal chromosome. As compared with matched normal liver tissue, hepatocellular carcinomas showed extinction or significant reduction of expression of one of the alleles of the CDKN1C, SLC22A1L, and IGF2 genes. Loss of maternal-specific methylation at the KvDMR1 locus in hepatocarcinoma correlated with abnormal expression of CDKN1C and IGF2, suggesting a function for KvDMR1 as a long-range imprinting center active in adult tissues. These results point to the role of epigenetic mechanisms leading to loss of expression of imprinted genes at chromosome region 11p15 in human tumors.

Adult↗

Muir-Torre-like syndrome in Fhit-deficient mice.

To investigate the role of the Fhit gene in carcinogen induction of neoplasia, we have inactivated one Fhit allele in mouse embryonic stem cells and produced (129/SvJ x C57BL/6J) F(1) mice with a Fhit allele inactivated (+/-). Fhit +/+ and +/- mice were treated intragastrically with nitrosomethylbenzylamine and observed for 10 wk posttreatment. A total of 25% of the +/+ mice developed adenoma or papilloma of the forestomach, whereas 100% of the +/- mice developed multiple tumors that were a mixture of adenomas, squamous papillomas, invasive carcinomas of the forestomach, as well as tumors of sebaceous glands. The visceral and sebaceous tumors, which lacked Fhit protein, were similar to those characteristic of Muir-Torre familial cancer syndrome.

Acid Anhydride Hydrolases↗

Regulation of TCL1 expression in B- and T-cell lymphomas and reactive lymphoid tissues.

Chromosomal rearrangements observed in T-cell prolymphocytic leukemia involve the translocation of one T-cell receptor gene to either chromosome 14q32 or Xq28, deregulating the expression of cellular protooncogenes of unknown function, such as TCL1 or its homologue, MTCP1. In the human hematopoietic system, TCL1 expression is predominantly observed in developing B lymphocytes, whereas its overexpression in T cells causes mature T-cell proliferation in transgenic mice. In this study, using a newly generated monoclonal antibody against recombinant TCL1 protein, we extended our analysis mainly by immunohistochemistry and also by fluorescence-activated cell sorting and Western blot to a large tumor lymphoma data bank including 194 cases of lymphoproliferative disorders of B- and T-cell origin as well as reactive lymphoid tissues. The results obtained show that in reactive lymphoid tissues, TCL1 is strongly expressed by a subset of mantle zone B lymphocytes and is expressed to a lesser extent by follicle center cells and by scattered interfollicular small lymphocytes. In B-cell neoplasia, TCL1 was expressed in the majority of the cases, including lymphoblastic lymphoma, chronic lymphocytic leukemia, mantle cell lymphoma, follicular lymphoma, Burkitt lymphoma, diffuse large B-cell lymphoma (60%), and primary cutaneous B cell lymphoma (55%). TCL1 expression was observed in both the cytoplasmic and nuclear compartments, as confirmed by Western blot analysis. Conversely, TCL1 was not expressed in Hodgkin/Reed-Sternberg cells, multiple myelomas, marginal zone B-cell lymphomas, CD30+ anaplastic large cell lymphoma, lymphoblastic T-cell lymphoma, peripheral T-cell lymphoma, and mycosis fungoides. These data indicate that TCL1 is expressed in more differentiated B cells, under both reactive and neoplastic conditions, from antigen committed B cells and in germinal center B cells and is down-regulated in the latest stage of B-cell differentiation.

Aged↗

Tcl1 enhances Akt kinase activity and mediates its nuclear translocation.

The TCL1 oncogene at 14q32.1 is involved in the development of human mature T-cell leukemia. The mechanism of action of Tcl1 is unknown. Because the virus containing the v-akt oncogene causes T-cell lymphoma in mice and Akt is a key player in transduction of antiapoptotic and proliferative signals in T-cells, we investigated whether Akt and Tcl1 function in the same pathway. Coimmunoprecipitation experiments showed that endogenous Akt1 and Tcl1 physically interact in the T-cell leukemia cell line SupT11; both proteins also interact when cotransfected into 293 cells. Using several AKT1 constructs in cotransfection experiments, we determined that this interaction occurs through the pleckstrin homology domain of the Akt1 protein. We further demonstrated that, in 293 cells transfected with TCL1, the endogenous Akt1 bound to Tcl1 is 5-10 times more active compared with Akt1 not bound to Tcl1. The intracellular localization of Tcl1 and Akt1 in mouse fibroblasts was investigated by immunofluorescence. When transfected alone, Akt1 was found only in cytoplasm whereas Tcl1 was localized in the cytoplasm and in the nucleus. Interestingly, Akt1 was also found in the nucleus when AKT1 was cotransfected with TCL1, suggesting that Tcl1 promotes the transport of Akt1 to the nucleus. These findings were supported by the intracellular localization of Akt1 or Tcl1 when Tcl1 or Akt1, respectively, were confined to the specific cellular compartments. Thus, we demonstrate that Tcl1 is a cofactor of Akt1 that enhances Akt1 kinase activity and promotes its nuclear transport.

Animals↗