In vitro testing of calcium channel blockers and cytotoxic chemotherapy in B-cell low-grade non-Hodgkin's lymphoma

The flux of calcium forms an important intracellular messenger system. The bcl-2 oncoprotein is thought to make cells resistant to a variety of insults, including cytotoxic drugs, by the suppression of apoptosis, which appears to involve the repartitioning of intracellular calcium. Three drugs that affect calcium pathways and may influence this repartitioning, i.e. dantrolene, azumolene (a water-soluble dantrolene analogue) and nimodipine, were studied in cell culture, using both a transformed follicle centre lymphoma cell line and primary culture of lymphoma cells in vitro in a manner that resulted in a growth pattern closely resembling that of the malignancy in vivo. Dantrolene and azumolene were potent inducers of cell death in both systems reducing the viable cell count by 70-90% in comparison with normal controls. Nimodipine, in comparison, appeared to have no significant effect. These results obtained in an in vitro setting suggest that further evaluation of dantrolene and azumolene for the treatment of low-grade non-Hodgkin's lymphoma is warranted.

Induction of CD80 expression in low-grade B cell lymphoma--a potential immunotherapeutic target

The CD80 antigen (B7) is expressed on activated B lymphocytes. It is thought to be important in eliciting a T cell response via its ligands CD28 and CTLA-4 when antigen is presented in the presence of the MHC-1 peptide. Low-grade B cell lymphomas analysed by flow cytometry express CD80 very poorly. However, when grown in vitro using the IL-4/anti-CD40 stromal cell culture system, following depletion of T and IgD-bearing cells, a monoclonal B cell expansion occurs. Cells harvested at days 10-13 express the antigen strongly, regardless of the histological subtype of lymphoma. Further investigation of CD80-mediated immune functions may be possible using this system as a basis for testing immunotherapy.

Mantle cell lymphoma: natural history defined in a serially biopsied population over a 20-year period

BACKGROUND

The histological, immunological and molecular characteristics of mantle cell lymphoma have only recently been delineated. Amongst these characteristics possible factors of prognostic significance include histological growth pattern and blastoid change.

PATIENTS AND METHODS

66 previously untreated cases of mantle cell lymphoma were identified in a retrospective analysis. In 50 cases serial biopsies had been taken during the disease and in 20 cases autopsies had been performed. Besides established factors of prognostic significance, histological growth pattern and blastoid change were examined.

RESULTS

32 patients achieved an initial complete remission or good partial remission with most cases relapsing or progressing within 2 years. The median survival was 36 months. Factors predicting a poor outcome were high presenting stage, age > 70, low sodium, low albumin and splenomegaly. Blastoid transformation was also a poor prognostic feature, occurring in 32% of cases during life and in 70% of autopsies. Histological growth pattern had no influence on outcome.

CONCLUSION

This study emphasises the difficulties in treating mantle cell lymphoma and the high frequency and prognostic importance of histological transformation.