The WEHI 231 B cell lymphoma is used as a model of self-tolerance by clonal deletion because B cell receptor (BCR) ligation results in apoptosis. Two critical events precede cell death: an early rise and fall in expression of MYC and cell-cycle arrest associated with enhanced expression of p21, p27, and p53. CTCF is a transcription factor identified as a repressor of MYC recently shown to cause...

One of the major unresolved questions in B cell biology is how the B cell Ag receptor (BCR) differentially signals to transduce anergy, apoptosis, proliferation, or differentiation during B cell maturation. We now report that extracellularly regulated kinase-mitogen-activated protein kinase (Erk-MAP kinase) can play dual roles in the regulation of the cell fate of the immature B cell lymphoma, ...

Nitric oxide (NO) is produced by murine macrophages in response to cytokines and/or gram-negative bacterial lipopolysaccharide. NO induction by gram-positive bacteria such as group B streptococci (GBS), the major etiologic agents of neonatal pneumonia and meningitis, has received little study. GBS as well as two other gram-positive bacterial species, Staphylococcus aureus and Staphylococcus epi...

OBJECTIVE Differentiation therapy with the hormonal form of vitamin D, 1alpha,25-dihydroxyvitamin D(3) (1,25D(3)), is a promising approach to treatment of acute myeloid leukemia (AML); however, 1,25D(3) induces hypercalcemia at pharmacologically active doses. We investigated the in vitro and in vivoantileukemic efficacy of combined treatment with non-toxic doses of a low-calcemic 1,25D(3) analo...

Medicinal plants and herbs are widely used in the treatment of various types of cancer in Taiwan, China and many other countries. Hedyotis diffusa Willd (HDW) has been known as a traditional Chinese medicine for a long time, and possesses various bioactivities and anticancer activity. There is no available information on the effects of HDW extracts in leukemic mice and on immune responses in vi...

Abstrad Cross-linking of B-cell membrane immunoglobulin (Ig) receptors induces growth arrest at G1-S, leading to apoptosis and cell death in the immature lymphomas WEHI-231 and CH31, but not in the CH12 B-cell line. In this system, which has been used as a model for Bcell tolerance, we have established that these lymphomas produce adive transforming growth fador (TGF8) when treated with anti-Ig...

H-rev107 is a tumor suppressor originally isolated in revertants of H-ras-transformed cell lines. The gene is ubiquitously expressed in normal tissues but down-regulated in primary carcinomas or in many cell lines derived from tumors, including WEHI 7.1 lymphoma cells. Here, we show that unlike in H-rev107-expressing cells or tissues the 5'-end of H-rev107 containing a CpG-rich region of 421 bp...

Engagement of the B cell receptor of WEHI 231 immature B cells leads sequentially to a drop in c-Myc, to induction of the cyclin-dependent kinase inhibitor p27Kip1, and finally to apoptosis. Recently we demonstrated that the drop in c-Myc expression promotes cell death, whereas the induction of p27 has been shown to lead to growth arrest. In this paper, we demonstrate that increased p27 express...

PURPOSE Despite significant advances have been achieved in cancer therapy, response to conventional treatments like surgery, radiotherapy and chemotherapy varies among individuals. Immunotherapy is known to be an effective strategy for patients who are resistant to the currently available interventions. METHODS Ninety-six male Balb/c mice (aged 6-8 weeks) were selected and divided into twelve...