P-glycoprotein is a product of the multidrug resistance (MDR1) gene, which is a major cause of the refractoriness of malignant lymphomas to conventional chemotherapeutic regimens containing anthracycline. l-asparaginase-containing regimens such as SMILE (steroid, methotrexate, ifosfamide, l-asparaginase, and etoposide) are effective for ENKL.
Drug accumulation was measured in a human ABCB1 gene-transfected mouse lymphoma cell line and in a human lung cancer cell line by flow cytometry; furthermore, their anticancer effects were determined in mice in vivo.
Our results show that P-gp was expressed in histiocytes but not ML cells in LN, and suggest that this molecule may play an important role in the biological function of histiocytes and/or for maintenance of homeostatic levels in T-cell ML LN.
Steroid derivatives were studied for their growth-inhibitory effect, cytotoxicity, reversal of multidrug resistance, apoptosis induction, and interaction with doxorubicin on multidrug resistant human ATP-binding cassette, sub-family B, member 1 (ABCB1) gene-transfected mouse T-lymphoma cell line, and human PC-3 and LNCaP prostate cancer cell lines in vitro.
Compounds 1-25 were evaluated for their effects on the reversion of multidrug resistance (MDR) in cancer cells mediated by P-glycoprotein (P-gp/ABCB1), through combination of functional and chemosensitivity assays, using a human ABCB1-transfected mouse T-lymphoma cell model.
MDR1 RNA levels were also increased in some cancers at relapse after chemotherapy, including ALL, ANLL, breast cancer, neuroblastoma, pheochromocytoma, and nodular, poorly differentiated lymphoma.
In this study, we examined the expression and activity of P-gp on NK cells derived from three normal donors, six patients with indolent NK cell-lineage granular lymphocyte-proliferative disorder (NK-GLPD), three patients with aggressive NK cell tumors (one NK cell leukemia and two nasal NK cell lymphoma), and two NK cell lines.
Through use of oligonucleotide hybridization, the genomic content and expression of individual MDR-1 alleles were examined in normal tissues, unselected and drug selected cell lines, and malignant lymphomas.
Thirteen of 57 lymphomas (23%) showed strong staining of greater than 50% of neoplastic cells; 15 of 57 (26%) showed labeling of a minority (11-50%) of neoplastic lymphocytes; 14 of 57 (25%) yielded equivocal results (reactivity in less than 10% of cells); and 15 of 57 (26%) were negative forP-glycoprotein.
In order to extend knowledge about pharmacophoric features responsible for ABCB1 inhibitory properties of imidazolidin-2,4-dione derivatives, 1'-[4-(4-(o-methoxyphenyl)-piperazin-1-yl)butyl]-3'-methyl-spiro(fluoren-9,5'-imidazolidine)-2',4'-dione (3) and its salt (4) with rhodanine-3-acetic acid (RA) were prepared and investigated by X-ray diffraction method, as well as their efflux modulating effects in cancer cells (mouse T-lymphoma), cytotoxic and antiproliferative activities were evaluated in vitro.
Despite a considerable variability in the results of these studies investigating Pgp expression in lymphoma, the preponderance of the data suggests that Pgp may at least in part account for drug resistance in this disease.
Compounds 1-14 were evaluated for their MDR-reversing activity on human ABCB1 gene transfected mouse lymphoma cells (L5178Y-MDR) through a combination of functional and chemosensitivity assays.
Since cytochrome P450 3A subfamily (CYP3A) enzymes are involved in the inactivation of chemotherapy drugs, we hypothesized that CYP3A and P-glycoprotein (MDR1) expression in these lymphomas could result in a poor clinical response.
Forty cultured human leukemia and lymphoma cell lines never exposed to anticancer agents in culture, apart from doxorubicin (ADM)-resistant K562/ADM, were examined for reactivity with a monoclonal antibody, MRK16 in F(ab')2 form [MRK16-F(ab')2], which recognizes P-glycoprotein (P-gp).
To explore the possibility of using anti-B4-bR in combination with chemotherapy protocols, we investigated the in vitro and in vivo cytotoxic effects of combining it with doxorubicin or etoposide using the lymphoma cell line Namalwa and a P-glycoprotein-expressing cell line, Namalwa/mdr-1, obtained by retroviral infection of Namalwa cells with the mdr-1 gene.
A series of novel imidazo[4,5-b]pyridine derivatives were synthesized and their biological activities were evaluated in vitro using parental (PAR) and multidrug resistant (MDR; ABCB1-overexpressing) mouse T-lymphoma cells.
Neither codeinone nor morphine inhibited P-glycoprotein-mediated rhodamine-123 efflux in multidrug resistant mouse T lymphoma L5178 transfected with human MDR 1 gene.
P-glycoprotein expression and phenotypes of lymphoma cells were examined by immunohistochemical staining using UIC2 as an anti-P-gp monoclonal antibody.
Fourteen hydantoin derivatives were synthesized and studied for their capacity to increase accumulation of ethidium bromide (EB) by mouse lymphoma cancer cells that were transfected with the human ABCB1 gene and overexpress the human ABCB1 pump.