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Expression of CT45 in Hodgkin lymphoma is characterized

10-19-2006

Scientists characterize the expression of CT45 in Hodgkin lymphoma in a recent issue of Clinical Cancer Research.

According to recent research from Germany, "The monoclonal antibody Ki-A10 (IgG1) generated after immunization of mice with Hodgkin lymphoma cell line L428 detects a nuclear antigen in human tissues with a restricted distribution pattern similar to cancer/testis antigens. The aim of this study was to characterize the antigen and to determine the expression profile in Hodgkin lymphoma."

"The half-life and phosphorylation of the antigen were determined by radio-labeling," said Hans-Jurgen Heidebrecht at the University of Kiel and collaborators in Germany. "The antigen was characterized by immunopurification and sequencing. Demethylation of genes is used to induce cancer/testis antigens. Ki-A10-negative cells were treated with 5-aza-2'-deoxycytidine. The Ki-A10 expression in paraffin-embedded tumors was determined immunohistochemically."

"Immunopurification of the 25/22-kDa antigen and sequencing revealed a peptide of 14 amino acids corresponding to the gene product of the newly described gene family MGC27005, located on chromosome Xq26.3, now termed CT45," reported Heidebrecht and his colleagues. "CT45 is significantly phosphorylated and down-regulated during mitosis. Demethylation of CT45-negative HeLa cells and stimulated peripheral blood lymphocytes induced CT45 expression."

The researchers reported, "Except testis, immunohistochemical stainings of normal tissues, reactive lymphoid lesions, and most malignant tumors were negative. In comparison, 54 of 99 (55%) samples from pediatric and adolescent Hodgkin lymphoma patients enrolled in the multicenter trial HD-95 stained Ki-A10 positive. Ki-A10 expression correlated with histologic subtypes (nodular sclerosis Hodgkin lymphoma 68% versus mixed cellularity Hodgkin's lymphoma 40% versus nodular lymphocyte predominant Hodgkin lymphoma 9%; p<0.001)."

The investigators concluded, "Ki-A10 is the first monoclonal antibody that detects CT45. As benign lymphoid lesions did not express CT45, the use of Ki-A10 antibody will facilitate the discrimination of Hodgkin's lymphoma from reactive lymphadenopathies."

Heidebrecht and his coauthors published their study in Clinical Cancer Research (Characterization and expression of CT45 in Hodgkin's lymphoma. Clin Cancer Res, 2006;12(16):4804-4811).

For additional information, contact Hans-Jurgen Heidebrecht, Department of Hematopathology and Lymph Node Registry, University of Kiel, Niemannsweg 11, D-24105 Kiel, Germany. E-mail: hheidebrecht@path.uni-kiel.de.

Publisher contact information for the journal Clinical Cancer Research is: American Association for Cancer Research, 615 Chestnut Street, 17th Floor, Philadelphia, PA 19106-4404, USA.

Keywords: Kiel, Germany, Cancer Vaccine, Vaccine Development, Immunology, Immunotherapy, Hodgkin Lymphoma, Monoclonal Antibody, Oncology, Proteomics.

This article was prepared by Cancer Vaccine Week editors from staff and other reports. Copyright 2006, Cancer Vaccine Week via NewsRx.com.