Use of Erythropoietin for Enhancing Immune Responses and for Treatment of Lymphoproliferative Disorders

Example 1

Treatment with EPO Prolongs the Survival of MOPC-315 Bearing Mice

[0054]The experimental system of the MOPC-315 tumor was set up as described in Materials and Methods above. Thirty mice (15 in each group) BALB / c were injected subcutaneously (s.c.) with 104 MOPC-315 cells in the abdominal area. Local tumor growth (2-5 mm diameter) was observed 11-13 days after injection, gradually growing in size and causing death in 90-100% of mice 40-50 days after injection. Subcutaneous rHuEPO treatment was initiated when a tiny palpable tumor appeared at the site of injection. Each mouse was numbered and a follow-up of tumor size in individual mice was carried out every day during EPO administration.

[0055]Treatment with EPO was conducted as described in WO 99 / 52543, namely, 30 units of rHuEPO were injected s.c. in the back of MOPC-315-bearing mice, 9 days following tumor injection. As the EPO preparation contains high amounts of albumin (×1000 higher than the EPO), the control mice were

Example 2

Treatment with EPO Slows the Rate of MOPC-315 Tumor Growth in Mice Compared to Tumor Growth in Albumin-injected Mice

[0057]While setting up the MOPC-315 system, we focused on the “progressor” mice with the following question in mind: Is the growth of the MOPC-315 tumor in the EPO-treated “progressor” mice similar to that of the control mice injected with albumin? Statistical analysis of the predicted rate of tumor growth, based on the data obtained in Example 1, shows that the tumor growth rate in EPO-treated progressor mice is significantly slower than that in albumin-injected progressor mice (FIG. 2). Thus, even in mice in which the tumor progresses, the progression in EPO-treated mice is slower, compared with the controls non-treated mice.

Example 3

EPO Treatment Results in Elevation of Endogenous (non-pathological) λ Light Chain

[0058]The mouse myeloma MOPC-315 cells synthesize and secrete immunoglobulin IgA with λ2 light chain and an α heavy chain. The molecular weight of this light chain is slightly lower than that of the endogenous λ light chain, thereby enabling to differentiate between the multiple myeloma derived λ light chain and the normal endogenous λ light chain by Western blot analysis. Sera from regressor or progressor mice in both EPO treated and control groups were collected at various time points. The serum born λ light chains (both endogenous and derived from the MOPC 315 cells) was resolved by SDS-polyacrylamide gel electrophoresis and detected by Western blot analysis with anti λ light chain antibodies.

[0059]40 mice were injected with 104 MOPC-315 cells s.c. and after 9 days treated with either EPO or EPO diluting solution only. Sera was collected at various time points and analyzed by Western blots for