Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic immunization against tumor antigens is an effective way to induce an immune response able to oppose cancer progression. Overexpression of HER-2/neu can lead to neoplastic transformation and has been found in many human primary breast cancers. We constructed DNA expression vectors encoding the full-length neu oncogene of rat cDNA (pCMV-NeuNT), the neu extracellular domain (pCMV-ECD), or the neu extracellular and transmembrane domains (pCMV-ECD-TM). We evaluated whether i.m. injection of these plasmids induces protection against the development of mammary tumors occurring spontaneously in FVB/N neu-transgenic mice. We found that pCMV-ECD-TM induced the best protection, whereas both pCMV-ECD and pCMV-NeuNT were less effective. The coinjection with a bicistronic vector for murine IL-12 increased the efficacy of pCMV-ECD and pCMV-NeuNT plasmids, and led to the same protection obtained with pCMV-ECD-TM alone. Anti-neuECD antibodies were detected in pCMV-ECD-TM vaccinated mice and, after coinjection with pCMV-IL12 plasmids, they appeared also in animals immunized with pCMV-ECD. Our data demonstrate the effectiveness of DNA vaccination using truncated Neu plasmids in inducing antitumor protection in a spontaneous mammary tumor model.
 ...
PMID:DNA vaccination with full-length or truncated neu induces protective immunity against the development of spontaneous mammary tumors in HER-2/neu transgenic mice. 1080 94

Tumors escape immune-mediated rejection by a variety of mechanisms during tumor progression. The elucidation of these mechanisms in vivo suffers from a lack of suitable models of spontaneous tumor formation escaping active specific immunotherapy (ASI). In a rat neu transgenic (rNeu-TG) mouse model of spontaneous breast tumor formation, we showed that rNeu-TG mice developed late escape tumors despite the presence of a persistent rNeu-specific immune response after ASI. Cell suspensions derived from these escape tumors grew in vaccinated tumor-free mice, whereas injected spontaneous tumor cells were rejected. Escape tumors retained rNeu or MHC class I expression but significantly upregulated Fas (CD95, Apo-1) ligand. We further demonstrated that Fas-L on escape tumor cells correlated with apoptosis of infiltrating T lymphocytes. Thus, our results provide evidence that spontaneous breast tumors upregulate Fas-L expression after vaccination that may promote tumor escape in vivo after ASI.
 ...
PMID:Role of Fas ligand expression in promoting escape from immune rejection in a spontaneous tumor model. 1125 77

Transgenic mice expressing specific oncogenes usually develop tumors in a stochastic fashion suggesting that tumor progression is a multi-step process. To gain further understanding of the interactions between oncogenes and tumor suppressor genes during tumorigenesis, we have crossed a transgenic strain (TG.NK) carrying an activated c-neu oncogene driven by the MMTV enhancer/promoter with p53-deficient mice. c-neu transgenic mice have stochastic breast tumor formation and normal appearing salivary glands. However, c-neu mice heterozygous for a p53 deletion develop parotid gland tumors and loose their wild type p53 allele. c-neu mice with a homozygous p53 deletion have increased rates of parotid tumor onset suggesting that inactivation of p53 is required and sufficient for parotid gland transformation in the presence of activated c-neu. In contrast to the dramatic effect of p53 in parotid gland transformation, p53 loss has little effect on the rate or stochastic appearance of mammary tumors. In addition, p53 loss was accompanied by the down regulation of p21 in parotid gland tumors but not breast tumors. The parotid gland tumors were aneuploid and demonstrated increased levels of Cyclin D1 expression. These observations suggest that in c-neu transgenic mice, p53 alterations have differential tissue effects and may be influenced by the tissue specific expression of genes influencing p53 activity.
 ...
PMID:Inactivation of p53 tumor suppressor gene acts synergistically with c-neu oncogene in salivary gland tumorigenesis. 1131 88

In solid tumors, such as breast and ovarian cancer, the predominant genetic mechanism for oncogene activation is through gene amplification. The HER-2 (also known as ErbB2/c-erbB2/HER-2 / neu) oncogene is the most frequently amplified oncogene in breast cancer and its overexpression is associated with poor clinical outcome. In addition to its role in tumor progression, HER-2 has been implicated in altering tumor cell chemosensitivity to cytotoxic chemotherapy, particularly to anthracyclines. However, sophisticated in vitro studies have recently indicated that HER-2 may not have anything to do with the sensitivity of the cancer cells to cytotoxic drugs. Topoisomerase IIalpha gene is a target gene for many cytotoxic drugs and is located just by the HER-2 at the 17q12-q21. TopoIIalpha amplification and deletion may account for both relative chemosensitivity and resistance to anthracycline-therapy depending on the specific genetic defect at the topoIIalpha locus. Whereas HER-2 is an oncogene that clearly can drive tumor induction and growth, its function as a marker for chemoselection may be due to associated genetic changes in the topoIIalpha gene. Copyright 2000 Harcourt Publishers Ltd.
 ...
PMID:Effects of HER-2/neu on chemosensitivity of tumor cells. 1149 99

Targeted Genetics is developing, tgDCC-E1A, a E1A tumor suppressor gene therapy formulated in a non-viral, lipid-based delivery system as a potential treatment for solid tumors which overexpress the her-2/neu oncogene [221611]. Fournier is the European development partner [244180]. Preclinical studies of E1A in mouse models for human breast and ovarian cancer demonstrated inhibition of expression of the her-2/neu oncogene, a significant reduction in tumors and increased survival rate in the treated animals [244180]. Results of a phase I study of intratumoral liposomal-E1A gene therapy in patients with recurrent/refractory breast cancer and head and neck cancer were presented at the 1998 American Society of Clinical Oncology (ASCO) meeting. Results demonstrated that intratumoral delivery of the E1A gene caused a subsequent downregulation of HER-2/neu expression and tumor response. The phase I dose-escalation study treated nine patients with recurrent breast cancer and nine patients with head and neck cancer. In 16 patients evaluable for response, nine had stable disease, five had progressive disease and two had minor responses despite tumor progression at other sites. In one of six patients who had repeat biopsies of treated tumors, no pathological evidence of tumor was found. In four of seven patients evaluated to date (May 1998), evidence of downregulation of HER-2/neu was reported [287387,290118]. The first phase I trial in patients with breast and ovarian cancer was completed by the end of 1997. The second phase I trial, enrolling 12 to 24 patients with solid tumors, was initiated in April 1997. Its aim was to determine dosing and safety of tgDCC-E1A and evaluate levels of gene transfer and tumor response. Patients were administered tgDCC-E1A by intratumoral injections. The company completed this trial by the end of 1997. In October 1998, Targeted Genetics initiated a multicenter, open-label phase II clinical trial of tgDCC-E1A in patients with recurrent head and neck squamous cell carcinoma who have exhibited disease progression despite standard therapies. The study to be conducted at six medical institutions in the US will enrole up to 60 patients with an interim analysis scheduled to be performed after the first 20 evaluable patients have been enrolled. Patients will be treated with ten direct intratumoral injections of the E1A gene over a period of 8 weeks, with follow-up performed at week 12. Patients who demonstrate a response will be eligible for continued treatment and will be monitored for 1 year [300424]. Targeted Genetics has issued three patents covering methods and compositions of use of the E1A and LTgenes (qv) to treat a variety of cancers. US-05651964 covers the use of the E1A gene, US-05643567 and US-05641484 cover the use of either the E1A gene or the LT gene as cancer therapies. These three patents provide the company with broad patent protection for tgDCC-E1A and all future products based on the use of the E1A or LT gene as tumor suppressors [259808].
 ...
PMID:Technology evaluation: tgDCC-E1A, targeted genetics/MD Anderson. 1171 50

Ovarian neoplasms display a wide range of phenotypic differentiation patterns. In the recent past, molecular genetic aberrations have been increasingly identified in various types of ovarian tumors. Granulosa cell tumors most often contain numeric chromosomal aberrations (monosomy 22, trisomy 12 and 14). Numeric changes can also be found in benign and borderline epithelial neoplasms, however without demonstrating specific patterns. K-ras mutations are characteristic for mucinous ovarian tumors and for serous borderline (LMP) tumors. In serous LMP tumors they are associated with low level microsatellite instability. Complex chromosomal aberrations are not detected in benign and borderline tumors. Invasive ovarian carcinomas show complex genetic changes. Chromosomal gains at 3q26, 8q24 and 20q13 apparently represent early lesions, whereas loss of material of chromosomes 4, 13, 16, 18 and X is associated with tumor progression and poor prognosis. The main targets of chromosomal changes are regulatory genes of cell proliferation and apoptosis (e.g. p16, cyclin D1, Rb, p53, myc, bcl-2) and members of the signaling cascade of tyrosine kinase receptors (e.g. Her-2/neu, dab-2, K-ras, PI3-K, PTEN). The genetic alterations of ovarian neoplasms described so far apparently correlate with the different level of aggressiveness. However, they do not fully explain the spectrum of phenotypic variability of these tumors.
 ...
PMID:[Phenotype--genotype--correlation in ovarian neoplasia]. 1189 92

Immunotherapy could have a role in the therapy of colorectal cancer as there is now convincing evidence that the immune system can specifically recognize and destroy malignant cells. The MAb 17-1A has been used in advanced and primary disease, along with newer agents such as anti-epidermal growth factor receptor (EGFR) antibody. Immunotherapy with autologous tumour cell vaccine, genetic modification of immunostimulatory cytokines, suicide genes and TAAs as discussed. The multiplicity of peptide and carbohydrate antigens which can be potential targets for immunotherapy are also discussed. These include MUC1, Thomsen-Friedenreich and Sialosyl-Tn antigens and HER2 / neu. Active specific immunotherapy with the anti-idiotypic antibodies CEAVac and 105AD7, along with DC vaccines, is being currently used in adjuvant clinical trials. 105AD7 has been shown to cause significantly greater apoptosis of tumour cells in colorectal cancer patients, while CEAVac generated T cell proliferative anti-CEA responses. Dendritic cells pulsed with tumour mRNA or TAAs currently are being assessed in clinical trials. The role of HSPs in the anti-tumour immune response is discussed. Non-specific immunotherapeutic agents used in clinical trials with chemotherapeutic regimens have not shown any definitive benefit. Tumour progression may occur as result of escape from the host anti-cancer immune response. Better understanding of mechanisms of tumour evasion could explain why immunotherapy trials in patients have not shown better results. These include down-regulation of immune responses by the tumour, altered expression of MHC and/or TAAs by tumour cells, altered expression of adhesion molecules by tumour and/or DCs and usurpation of the immune response to the advantage of the cancer.
 ...
PMID:Current concepts in immunotherapy for the treatment of colorectal cancer. 1201 89

Protein tyrosine kinases are tightly regulated enzymes that play an important role in the control of most fundamental cellular processes, including cell proliferation, differentiation, metabolism, migration, and survival. These signaling proteins are the frequent target of oncogenic mutations or other genetic alterations leading to dysregulated tyrosine kinase activity, cellular transformation, and subsequent tumor progression. Many of the known dominant oncogenes encode aberrant protein tyrosine kinases and are causally associated with a significant fraction of human neoplasms, including breast carcinoma. The epidermal growth factor receptor and HER2/neu are two transmembrane tyrosine kinases that are members of the HER (erbB) signaling network. Aberrant signaling by this network is present in a cohort of breast carcinomas. Structure/function studies of these kinases have led to the identification of molecular approaches aimed at disabling signaling by this transforming network. Trastuzumab, a monoclonal antibody that binds the ectodomain of HER2, was recently shown to induce regression of HER2-overexpressing breast cancers, confirming the role of HER2 in tumor maintenance and progression. A rational therapeutic approach that builds on these results with trastuzumab and expands the targeting of the HER network will be presented.
 ...
PMID:HER (erbB) tyrosine kinase inhibitors in the treatment of breast cancer. 1213 92

The main focus of the Symposium was the fact that cell types of the innate and adaptive immune systems can have tumor-favoring as well as tumor antagonistic effects, both in a preventive and therapeutic mode. It was shown that macrophages (Mphi) and dendritic cells within a tumor exert tumor-favoring effects through the action of certain cytokines. Inflammatory reactions could favor the onset and growth of tumors. Dual immune functions were shown with CD4+ T cells and certain matrix metalloproteinase (MMP) activities favoring tumor progression and CD8+ T cells and certain heat shock proteins having antitumor action. Lack of antitumor action despite positive immune stimulation was also shown to depend on the existence of barriers to tumor infiltration by lymphocytes; remodeling of vasculature, e.g., by IFNgamma-induced cytokines like MIG and IPIO, reversed this type of impediment. Certain CXC cytokines increased tumor progression, whereas others, particularly those induced by IFNgamma, had the opposite effect; stromal-derived factor-1 and its receptor CXCR4 affected tumor propensity to metastasize in certain organs. Stromal-derived factor-1 induced MMP9, which in turn regulated the bioavailability of vascular endothelial growth factor and the cascade of its tumor-favoring effects, whereas granulocyte colony-stimulating factor decreased MMP9 and the consequences of its action. The effects of certain proinflammatory cytokines and vascular endothelial growth factor functions in angiogenesis and lymphoangiogenesis were also discussed. The favoring effects of fever-like thermal stress on the function of molecules instrumental in lymphoid cell adhesion to vessels and infiltration into sites of immune actions were described. The mechanisms involved in the development of immune memory and those conditioning Type I and CTL responses were also discussed. A number of presentations were concerned with laboratory studies aimed at developing clinical regimens with potential activity in the prevention or treatment of cancer. Prevention of Her2/neu breast cancer in transgenic mice was achieved by suitable regimens with IL12 combined with vaccines, including DNA-based vaccines administered in conjunction with electroporation. Vaccination with shared tumor antigen MUCI or cyclin B was discussed, and its clinical translation was described. The prevention of TRAMP prostate tumor in transgenic mice by anti-CTLA4 antibody plus vaccine was described, as was the translation of these regimens to the clinics. Clinical successes in melanoma patients using antimelanoma antigen antibodies in a therapeutic mode and precautions to be exerted in evaluating in vivo immune responses based on in vitro assays were emphasized. The symposium was concluded with an overall discussion focused on basic questions related to the capability of immunity to exert tumor-favoring or antitumor effects depending on conditions determined by both tumor and host functions.
 ...
PMID:Fourteenth Annual Pezcoller Symposium: the novel dichotomy of immune interactions with tumors. 1278 11

Growth factors and estrogen receptor (ER) signaling cooperate to play essential roles in cell proliferation, differentiation and tumor progression in mouse reproductive organs. Treatment of neonatal mice with diethylstilbestrol (DES) induces an estrogen-independent persistent proliferation and cornification of the vaginal epithelium, which results in cancerous lesions later in life. However, the mechanisms of the estrogen-dependent and -independent pathways essentially remain unknown. We characterized the expression of epidermal growth factor (EGF)-like growth factors (EGF, transforming growth factor alpha (TGF-alpha), heparin-binding EGF-like growth factor (HB-EGF), betacellulin (BTC), amphiregulin (APR), epiregulin (EPR) and neuregulin (NRG) 1) and erbB receptors (EGF receptor (EGFR), erbB2/neu, erbB3 and erbB4) in the vaginae of mice treated either neonatally (0-4 day) or as adults (55-59 day) with estrogens. EGFR and erbB2 were activated in the vaginal epithelium of mice by estrogen treatment. This activation was also encountered in vaginae from neonatally DES-exposed mice, along with the expression of EGF, TGF-alpha, HB-EGF, BTC, APR, EPR and NRG1. Immunohistochemical analysis indicated that erbB2 was primarily expressed in vaginal epithelium. Finally, we found that serine 118 and 167 located in the AF-1 domain of ERalpha were phosphorylated in these vaginae. AG825, AG1478 or ICI 182,780 administration blocked proliferation of vaginal epithelium induced by neonatal DES exposure. Thus, signal transduction via EGFR and erbB2 could be related to the estrogen-induced vaginal changes and persistent erbBs phosphorylation and sustained expression of EGF-like growth factors, leading to ERalpha activation that may result in cancerous lesions in vaginae from neonatally DES-exposed mice later in life.
 ...
PMID:Estrogen-independent activation of erbBs signaling and estrogen receptor alpha in the mouse vagina exposed neonatally to diethylstilbestrol. 1464 53


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>