Vaccination with naked DNA elicits cellular and humoral immune responses that have a T helper cell type 1 bias. However, plasmid vectors expressing large amounts of gene product do not necessarily induce immune responses to the encoded antigens. Instead, the immunogenicity of plasmid DNA (pDNA) requires short immunostimulatory DNA sequences (ISS) that contain a CpG dinucleotide in a particular base context. Human monocytes transfected with pDNA or double-stranded oligonucleotides containing the ISS, but not those transfected with ISS-deficient pDNA or oligonucleotides, transcribed large amounts of interferon-alpha, interferon-beta, and interleukin-12. Although ISS are necessary for gene vaccination, they down-regulate gene expression and thus may interfere with gene replacement therapy by inducing proinflammatory cytokines.

In our study, we present experimental evidence suggesting that curcumin exerts multiple different suppressive effects on human breast carcinoma cells in vitro. Our experiments demonstrate that curcumin's antiproliferative effects are estrogen dependent in ER (estrogen receptor)-positive MCF-7 cells, being more pronounced in estrogen-containing media and in the presence of exogenous 17-␤ estradiol. Curcumin inhibits the expression of ER downstream genes including pS2 and TGF-␤ (transforming growth factor) in ER-positive MCF-7 cells, and this inhibition is also dependent on the presence of estrogen. Curcumin also decreases ERE (estrogen responsive element)-CAT activities induced by 17-␤ estradiol. In addition, we demonstrate that curcumin exerts strong antiinvasive effects in vitro that are not estrogen dependent in the ER-negative MDA-MB-231 breast cancer cells. These antiinvasive effects appear to be mediated through the downregulation of MMP-2 (matrix metalloproteinase) and the upregulation of TIMP-1 (tissue inhibitor of metalloproteinase), 2 common effector molecules that have been implicated in regulating tumor cell invasion. Our study also demonstrates that curcumin inhibits the transcript levels of 2 major angiogenesis factors VEGF (vascular endothelial growth factor) and b-FGF (basic fibroblast growth factor) mainly in ER-negative MDA-MB-231 cells. © 2002 Wiley-Liss, Inc. Key words: curcumin; chemoprevention; breast cancer; angiogenesis; estrogenBreast cancer chemoprevention is the subject of substantial research efforts to improve the health of women in the United States. Epidemiologic surveys suggest that diet has an impact on cancer incidence. Frequent consumption of vegetables and fruits decreases the risk for human cancer. 1,2 Although risk reduction by nutritional intervention alone may not be sufficient to protect high-risk individuals against cancer development, it would be very useful to identify agents with chemopreventive potency and to evaluate them in combination with nutritional intervention. 3,4 Recently, attention has been focused on identifying dietary phytochemicals that have the ability to inhibit the processes of carcinogenesis. Extracts of plants or their fractionated ingredients are found to possess inhibitory effects against chemically induced carcinogenesis. 5 Curcumin is a major component of turmeric, the dried rhizome of Curcuma longa L., which is commonly used as a yellow coloring and flavoring agent in food items in Asian countries. Commercial-grade curcumin has shown anticarcinogenic activity in animals as indicated by the ability to block colon tumor initiation induced by azoxymethans 6 and skin tumor promotion induced by phorbol ester. 7 Curcumin also has been reported to possess antiinflammatory activity and is a potent inhibitor of reactive oxygen-generating enzymes such as lipooxygenase/cyclooxygenase, 8,9 xanthine dehydroxygenase/oxidase 10 and nitric oxide synthase (NOS). 11,12 Recently, it has been shown that the administration of synthetic curcumin in the diet during t...

Our results suggest that bFGF in urine deserves further evaluation of its potential use as a monitor of therapy or as a predictor of outcome once a cancer has been diagnosed.

The desmoplastic response to human breast carcinoma is a host myo®broblast-mediated collagenous response exhibiting synergistic e ects on tumor progression. Although many paracrine interactions between breast carcinoma cells and myo®broblasts have been characterized, the event(s) which initiate desmoplasia have remained unde®ned. Our studies utilized c-ras H transfected MCF-7 cells which overexpress ras p2l and which are weakly tumorigenic in ovariectomized nude mice. The xenografts are desmoplastic and comprised of 30% myo®broblasts and 60 mg/g of interstitial collagen. In situ hybridization studies of these xenografts reveal a stromal gene expression pattern (stromelysin-3, IGF-II and TIMP-1) identical to that observed in human tumor desmoplasia. 17-b estradiol increases c-ras H MCF-7 growth but abolishes desmoplasia. c-ras H MCF-7 in vitro constitutively produce myo®broblast mitogenic activity which competes with PDGF in a receptor binding assay. This myo®broblast mitogenic activity is unaltered by 17-b estradiol/tamoxifen pretreatment in vitro. Transfection of c-ras H MCF-7 with a PDGF-A dominant negative mutant, 1308, produced by site-directed mutagenesis (serine?cysteine 129 ) reduces both homo-and heterodimer secretion of PDGF by as much as 90% but does not interfere with the secretion of other growth factors. Clones with low PDGF, though tumorigenic, are nondesmoplastic. Our results suggest that breast carcinomasecreted PDGF is the major initiator of tumor desmoplasia. Oncogene (2000) 19, 4337 ± 4345.

The TCL1 protooncogene is overexpressed in many mature B cell lymphomas, especially from AIDS patients. To determine whether aberrant expression promotes B cell transformation, we generated a murine model in which a TCL1 transgene was overexpressed at similar levels in both B and T cells. Strikingly, transgenic mice developed Burkitt-like lymphoma (BLL) and diffuse large B cell lymphoma (DLBCL) with attendant Bcl-6 expression and mutated J H gene segments at a very high penetrance beginning at 4 months of age. In contrast, only one mouse developed a T cell malignancy at 15 months, consistent with a longer latency for transformation of T cells by TCL1. Activation of premalignant splenic B cells by means of B cell antigen receptor (BCR) engagement resulted in significantly increased proliferation and augmented AKT-dependent signaling, including increased S6 ribosomal protein phosphorylation. Transgenic spleen cells also survived longer than wild-type spleen cells in long-term culture. Together these data demonstrate that TCL1 is a powerful oncogene that, when overexpressed in both B and T cells, predominantly yields mature B cell lymphomas.T he TCL1 (T cell leukemia 1) protooncogene is expressed in CD3 Ϫ CD4 Ϫ CD8 Ϫ precursor T cells and is extinguished at the CD4 ϩ CD8 ϩ stage of thymocyte development (1). In B cells, TCL1 is first expressed in pro-B cells and remains high in naive mantle zone B cells of peripheral lymphoid tissues (1-4). Downregulation of TCL1 expression in follicle center centroblasts and centrocytes is followed by gene extinction in post-germinal center (GC) memory B cells and plasma cells (4, 5).Continued high-level TCL1 expression, because of chromosomal rearrangements, was implicated in mature peripheral T cell malignancies (6, 7). Polyclonal and oligoclonal T cell expansions preceded clonal outgrowth by many years, suggesting that additional lesions were required for transformation (8,9). Supporting this tumorigenic mechanism, transgenic mice expressing TCL1-familymember proteins exclusively in T cells developed polyclonal T cell expansions before the evolution of clonal malignancies at 15 to 20 months (10, 11). Overexpression of TCL1, or MTCP1 (mature T cell proliferation 1), in mouse T cells did not affect B cell development or produce B cell lymphomas. These findings indicate that aberrant expression of TCL1 or MTCP1 in T cells perturbs T cell homeostasis through cell autonomous pathways without inducing premalignant or malignant changes in bystander B cells.About 15% of AIDS patients develop aggressive B cell nonHodgkin lymphoma (AIDS-NHL) (12, 13). Most AIDS-NHL originate from GC or post-GC B cells, but the early events leading to AIDS-NHL remain poorly defined (13,14). Diffuse large B cell lymphoma (DLBCL) is the most prevalent type of AIDS-NHL, and these tumors generally lack consistent genetic and͞or viral tumorpromoting alterations. Recently, abundant TCL1 expression was shown in a high percentage of AIDS-NHL of post-GC origin (3,4). This discovery led us to postulate that TCL1 dy...

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To identify cell adhesion molecules required for angiogenesis, we used an in vitro model in which bovine capillary endothelial cells can be induced to form capillary-like tubes. Monoclonal antibodies directed against the carbohydrate epitopes sialyl Lewis-X and sialyl Lewis-A inhibited capillary formation. We postulated that a member of the selectin family of adhesion molecules may be involved in capillary formation because these proteins bind to sialyl Lewis-X/A-containing ligands. We isolated a 2.8-kilobase complementary DNA from a bovine capillary endothelial cell cDNA library which encodes a polypeptide with 71% identity to human E-selectin. We report here that antibody directed against the bovine E-selectin inhibited capillary formation, suggesting that in addition to its role in leukocyte adhesion to endothelium, a form of E-selectin is involved in capillary morphogenesis.

IntroductionMalignant tumor growth is characterized by extensive neovascularization (angiogenesis) and vascular permeability (VP). Although tumors express and secrete a wide range of cytokines and growth factors, vascular endothelial growth factor/vascular permeability factor (VEGF or VPF) is unique in that only VEGF induces VP as well as vascular proliferation and endothelial cell migration. [1][2][3][4] The nonreceptor tyrosine kinase, Src, has been previously shown to be essential in specific VEGF pathway signaling responses. For example, in studies using knockout mice, VEGF-induced VP was blocked in src Ϫ/Ϫ mice, a phenotype termed "leakage resistant." 5,6 In contrast, both control and src Ϫ/Ϫ mice supported relatively normal development and vessel sprouting in response to angiogenic growth factors, 5 suggesting that distinct signaling intermediates may be essential for different VEGF-induced vascular responses.The distinction between VEGF-induced angiogenesis and VEGFinduced VP in Src-deficient mice provides an opportunity to examine the differences between VEGF-induced VP and general blood vessel sprouting mechanisms independently. Previous studies suggested that endothelial cells were the cell type most affected by the defect in VEGF-induced VP and intracellular signaling in mice lacking Src. [5][6][7] While aberrant VP is associated with malignant tumor growth, the capacity for the endothelial barrier of host blood vessels to regulate the metastasis of tumor cells has been poorly understood. 2,8,9 For example, hemostatic factors such as fibrinogen and fibrinogen-degradation products (FDPs) influence tumor cell metastasis, 10-13 as demonstrated by studies in which mice lacking fibrinogen fail to support a robust spontaneous metastatic response. 11,14 Primary tumor progression can be reduced by inhibition of endothelial nitric oxide (eNOS), an important mediator of both VP and angiogenesis. 15 These studies suggested that the eNOS-mediated tumor response was independent of Src activation.The capacity for specific signaling intermediates involved in the VEGF-induced VP response to influence tumor growth and metastasis remains unclear. To determine whether vascular leak resistance has an effect on tumorigenesis, we have examined the primary tumor growth and spontaneous metastasis of a syngeneic tumor cell line in src-null and control mice. Previous studies have shown that following the administration of recombinant VEGF 5 or following a pathologic insult, for instance, cerebral ischemia 6 or myocardial infarction, 16 there was a Src-mediated increase in VP. In these studies, the absence of Src was associated with a reduction in VEGF-mediated VP, reduced cerebral ischemia-induced infarct volume, and reduced heart tissue damage.In this study, we characterize the effect of a Src-mediated VP defect on the growth and metastasis of a VEGF-expressing lung carcinoma. We used a Src-deficient mouse model of vascular leak resistance to characterize the growth of a murine syngeneic sub-line of Lewis lung carcinoma (D121...