Search results for "Assay"

Targeting apoptosis proteins in hematological malignancies

2010

The apoptotic machinery plays a key role in hematopoietic cell homeostasis. Terminally differentiated cells are eliminated, at least in part, by apoptosis, whereas part of the apoptotic machinery, including one or several caspases, is required to go through very specific steps of the differentiation pathways. A number of hematological diseases involve a deregulation of this machinery, which in most cases is a decrease in cell sensitivity to pro-apoptotic signals through over-expression of anti-apoptotic molecules. In some situations however, e.g. in the erythroid lineage of low grade myelodysplastic syndromes, cell sensitivity to apoptosis is increased in a death receptor-dependent manner a…

Efficacy of CAR-T immunotherapy in MET overexpressing tumors not eligible for anti-MET targeted therapy

2022

Abstract Background Aberrant activation of the MET receptor in cancer is sustained by genetic alterations or, more frequently, by transcriptional upregulations. A fraction of MET-amplified or mutated tumors are sensible to MET targeting agents, but their responsiveness is typically short-lasting, as secondary resistance eventually occurs. Since in the absence of genetic alterations MET is usually not a tumor driver, MET overexpressing tumors are not/poorly responsive to MET targeted therapies. Consequently, the vast majority of tumors exhibiting MET activation still represent an unmet medical need. Methods Here we propose an immunotherapy strategy based on T lymphocytes expressing a Chimeri…

Neuron-specific enolase--a serum marker for malignant melanoma.

1989

Differential MHC class II component expression in HPV-positive cervical cancer cells: implication for immune surveillance.

2005

Effective eradication of human papillomavirus (HPV)-positive tumors may require CD8+ and CD4+ T-cell-mediated immune responses. Ectopic expression of MHC class II surface molecules has been described in the context of cervical cancer, but coexpression with other components of the MHC class II antigen presentation pathway has not been addressed. We have evaluated the MHC class II antigen presentation pathway in malignant squamous epithelium of HPV+ cervical cancer lesions by in situ costaining HLA-DR with CLIP or DMA/DMB. Cervical cancer cells exhibit 3 MHC class II phenotypes: (i) DR+/CLIP+ or DM+; (ii) DR+/CLIP- or DM-; and (iii) DR-/CLIP+ or DM+. The identical profile has been identified …

Bovine seminal ribonuclease is cytotoxic for both malignant and normal telomerase-positive cells

2005

Bovine seminal-ribonuclease (BS-RNase) is a member of the 'ribonucleases with special biological actions' family since it possesses specific anti-tumour, anti-spermatogenic and embryotoxic activities and exerts an immunosuppressive effect on T lymphocytes. In previous studies it was demonstrated that BS-RNase induced apoptosis in proliferating, malignant and normal cells and that telomerase activity loss also caused apoptotic death in neoplastic cells. Since an obvious relationship between cell proliferation and telomerase activity exists, the aim of this work was to study if the pro-apoptotic cytotoxic action exerted by BS-RNase on proliferating malignant cells (HT29) and proliferating nor…

Functional analysis ofp53 gene and the prognostic impact of dominant-negativep53 mutation in endometrial cancer

2005

In addition to the loss of function, mutant p53 can possess a dominant-negative effect on wild-type p53 and may also exert gain-of-function activity. It is not clear whether the functional status of p53 mutation contributes to differences in outcome in endometrial cancer. We collected a total of 92 RNA samples of high quality from endometrial cancer tissues, and the samples were subjected to yeast functional assay and sequencing for p53 mutations. The detected mutant p53 genes were further investigated for their dominant-negative activity using a yeast-based transdominance assay. p53 mutation was found in 24 out of 92 (26.1%) tumors, of which 10 exhibited no dominant-negative activity (rece…

Parthenolide generates reactive oxygen species and autophagy in MDA-MB231 cells. A soluble parthenolide analogue inhibits tumour growth and metastasi…

2013

Triple-negative breast cancers (TNBCs) are clinically aggressive forms associated with a poor prognosis. We evaluated the cytotoxic effect exerted on triple-negative MDA-MB231 breast cancer cells both by parthenolide and its soluble analogue dimethylamino parthenolide (DMAPT) and explored the underlying molecular mechanism. The drugs induced a dose- and time-dependent decrement in cell viability, which was not prevented by the caspase inhibitor z-VAD-fmk. In particular in the first hours of treatment (1–3 h), parthenolide and DMAPT strongly stimulated reactive oxygen species (ROS) generation. The drugs induced production of superoxide anion by activating NADPH oxidase. ROS generation caused…

Abstract 1778: Preclinical characterization of the safety and antitumor activity of IMAB027-vcMMAE, an anticlaudin 6 antibody-drug conjugate

2018

Abstract Background Claudin 6 (CLDN6) is a tight junction membrane protein whose expression in normal tissue is confined to embryonic cells, but is aberrantly expressed in various human cancers. The anti-CLDN6 monoclonal antibody (mAb), IMAB027, has shown promising antitumor activity in preclinical human CLDN6-positive (CLDN6+) cancer models. Conjugation of IMAB027 with monomethyl auristatin E (MMAE) may utilize the precision tumor-targeting of the mAb to deliver a highly effective cytotoxic drug to the tumor. In this report we present the preclinical characterization of this antibody–drug conjugate, IMAB027–vcMMAE. Methods Internalization of IMAB027 in various CLDN6+ human ovarian (OC) and…

Lysosomal alterations in heart and liver of mice treated with doxorubicin.

1985

This study was carried out to evaluate the influence of long-term treatment with doxorubicin (DXR) (4mg/kg IV for 5 weeks) on heart and liver lysosomes of mice. We evaluated the variations in both total and "sedimentable" enzyme activity of cathepsin D, which is the major endopeptidase of myocites and probably involved in physiologic and pathologic degradation of actomyosin and mitochondria, and that of acid phosphatase, which is more prominent in interstitial cells. Our results show that marked changes occur in both total and sedimentable enzyme activity of cathepsin D in the heart of treated animals and to a lesser extent in the liver. In contrast, no modification of either total or sedim…

Abstract 1855: Role of mTOR inhibition in triple-negative breast cancer

2016

Abstract BACKGROUND: Triple-negative breast cancers (TNBC) represent the 10-17% of all diagnosed breast cancers (BC) and are characterized by the absence of ER/PgR expression, HER2 amplification and often show a basal-like phenotype. TNBC are often diagnosed in patients with BRCA1 germline mutation and unfortunately treatment options are still limited. The mTOR (Mammalian Target Of Rapamycin) pathway seems to play an important role in BC pathogenesis and it is possible to target this pathway by inhibitors such as rapamycin. In human BC cross talk between ER/PgR receptors signaling and the mTOR pathway is believed to be responsible for resistance to hormone therapy probably due to a down reg…