Overexpression and purification of the recombinant diphtheria toxin variant CRM197 in Escherichia coli.

The expression of the recombinant diphtheria toxin mutant CRM197 in bacteria other than Corynebacterium diphtheriae has proven to be difficult. Here we propose a new and alternative procedure for the production of full-length CRM197 in Escherichia coli. The present study relates specifically to the expression of an artificial sequence and to a method for the isolation and purification of the corresponding protein.

CRM197 (nontoxic diphtheria toxin): effects on advanced cancer patients.

Purpose: Many years ago, diphtheria toxin (DT) showed antitumor activity in mice and in humans, but it was unclear whether this depended on the toxicity of the molecule only or on its strong inflammatory-immunological property as well. To deal with this open question, we planned to treat a group of cancer patients with cross-reacting material 197 (CRM197). CRM197 is a nontoxic mutant of DT that shares the immunological properties of the native molecule and its ability to bind to heparin-binding epidermal growth factor (HB-EGF), the specific cell-membrane receptor for DT that is often overexpressed in cancer.

Clinical implications of serum levels of soluble CD23 and tumor necrosis factor alpha in low-grade non-Hodgkin's lymphoma.

In the last few years the research for new biological features in low-grade non-Hodgkin's lymphoma has provided important results. Several biological parameters are under evaluation and, in particular, cytokines and soluble receptors levels are showing their importance as prognostic parameters. In the present study, serum levels of tumor necrosis factor alpha (TNF-alpha) and soluble CD23 (sCD23) were measured at the time of diagnosis and after induction polychemotherapy in 40 patients with newly diagnosed low-grade non-Hodgkin's lymphoma (LG-NHL).