The toxic A chain of ricin was linked to human transferrin via a disulfide bond and the resulting conjugate was shown to bind to cell membrane transferrin receptors. Surface-localized transferrin A chain (TF-A chain) gained access to the cytoplasm and inactivated ribosomes as witnessed by a rapid curtailment of cellular protein synthesis (t1/2 = 6 h) and subsequent cytolysis. The intact conjuga...

Glucocorticoids (GCs) induce apoptosis in lymphoid cells that contain functional GC receptors (GRs). However, GC resistance often is seen in cells with demonstrable GRs; one such line is CEM-C1. We have tested the hypothesis that positive interactions between GC and cyclic AMP (cAMP) regulate GC actions in CEM clones. Treatment of both GC-resistant CEM-C1 [resistant to 1 JIMdexamethasone (Dex)]...

Multidrug resistance is a major obstacle to the success of cancer chemotherapy. The multidrug resistance-associated protein (MRP) has been shown to confer multidrug resistance. To study MRP gene expression at the transcriptional level, we have fused the MRP gene promoter with the luciferase reporter gene and studied its regulation. Cotransfection of MRP promoter constructs with p53 expression p...

T cell Acute Lymphoblastic Leukemia/Lymphoma (T-ALL/LBL) is a precursor T cell leukemia/lymphoma that represents approximately 15% of all childhood and 25% of adult acute lymphoblastic leukemia. Although a high cure rate is observed in children, therapy resistance is often observed in adults and mechanisms leading to this resistance remain elusive. Utilizing public gene expression datasets, a f...

Glucocorticoids (GCs) induce apoptosis in lymphoid cells that contain functional GC receptors (GRs). However, GC resistance often is seen in cells with demonstrable GRs; one such line is CEM-C1. We have tested the hypothesis that positive interactions between GC and cyclic AMP (cAMP) regulate GC actions in CEM clones. Treatment of both GC-resistant CEM-C1 [resistant to 1 microM dexamethasone (D...

shiga toxins (stxs) are bacterial virulence factors produced by shigella dysenteriae serotype 1 and escherichia coli strains. stxs are critical factors for the development of diseases such as severe bloody diarrhea and hemolytic uremic syndrome. additionally, stxs trigger the secretion of pro- inflammatory cytokines and chemokines, particularly in monocytes or macrophages. the inflammatory cyto...

The growth of human CCRF-CEM T-cell lymphoblastic leukemia was studied in mice immune deprived by different techniques, and in CD-nu/ nu atli>mie mice. Female CBA/CaJ mice were immune deprived by infant thymectomy, priming with l-/î-i>-arabinofuranosylcytosine(200 mg/kg) 48 h prior to total body irradiation (925 cGy) designated Oara-Cy; or after thymectomy the mice received 925 cGy total body ...