Although rituximab is a key molecular targeting drug for CD20-positive B-cell lymphomas, resistance to rituximab has recently been recognized as a considerable problem. Here, we report that a CD20-negative phenotypic change after chemotherapies with rituximab occurs in a certain number of CD20-positive B-cell lymphoma patients. For 5 years, 124 patients with B-cell malignancies were treated wit...

Rituximab (chimeric anti-CD20 mAb) is currently used in the treatment of B-NHL and B cell malignancies, alone or in combination with chemotherapy. However, subsets of patients do not initially respond and/or develop resistance to additional treatments. Hence, there is a need to develop more effective anti-CD20 mAbs that may improve clinical response. BM-ca is a novel humanized anti-CD20 mAb tha...

CD20 is a B lymphocyte integral membrane protein with signal-transducing properties. Abs directed toward extracellular CD20 epitopes activate nonreceptor tyrosine kinases and modulate cell cycle progression of B lymphocytes. Recently, we demonstrated that binding of CD20 Abs to B cells induces the rapid redistribution of up to 95% of CD20 molecules to low density, detergent-insoluble membrane m...

background: formation of secondary structure such as dna hairpins or loops may influence molecular genetics methods and pcr based approaches necessary for genetic engineering, in addition to gene regulation. materials and methods: a polymerase chain reaction with splice overlap extension (soe-pcr) was used to create fully synthetic 1f5 chimeric anti-cd20 heavy- and light-chain genes. the chimer...

BACKGROUND & OBJECTIVE Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin's Lymphoma (CHL) express B-cell marker CD20 with a reported frequency of 5%-58%. The prognostic significance of CD20 expression in HRS cells of CHL is still controversial. This study was to investigate the prognostic significance of CD20 expression in naive CHL patients. METHODS The expression of CD20, CD15 and...

Lymphoid cells in most patients with chronic lymphocytic leukemia (CLL), when treated with rituximab, become CD20-. This is thought to be due to masking of CD20 by rituximab. We used specific antimouse immunoglobulin antibodies to detect rituximab on the surface of CLL lymphocytes and we demonstrate that rituximab is rarely detectable after therapy. Only 3 of 65 patients with CLL had rituximab ...

C-terminal mutations of CD20 constitute part of the mechanisms that resist rituximab therapy. Most CD20 having a C-terminal mutation was not recognized by L26 antibody. As the exact epitope of L26 has not been determined, expression and localization of mutated CD20 have not been completely elucidated. In this study, we revealed that the binding site of L26 monoclonal antibody is located in the ...