Sodium Caseinate (CasNa) Induces Mobilization of Hematopoietic Stem Cells in a BALB/c Mouse Model

Sodium Caseinate in Combination With Daunorubicin or Cytarabine Improves Survival of Mice With Long-established Leukemia

BACKGROUND/AIM

Although acute myeloid leukemia (AML) has traditionally been considered an oncological emergency and initiation of therapy is believed to be crucial to minimizing disease-related morbidity and mortality, it has also been suggested that a certain delay in treatment has no negative consequences in terms of response, early mortality, or survival. We aimed to determine the effect of administration of sodium caseinate (SC), a salt of casein, the main milk protein, with cytarabine or with daunorubicin on survival in mice with well-established leukemia.

MATERIALS AND METHODS

To assay the time of establishment of leukemia in the bone marrow, Balb/c mice were inoculated with 2.5×10 ⁵ WEHI-3 cells/mouse and after 3, 6 and 9 days were euthanized. Bone marrow mononuclear cells (BM-MNCs) of the femur were obtained and cultured for 120 h with or without rmIL-3 and cell proliferation was evaluated by the crystal violet technique. Then, the effect of administrating SC-cytarabine or SC-daunorubicin on survival rates of mice with well-established leukemia was assayed. Another group of Balb/c mice was inoculated with WEHI-3 cell and after 10 days mice were treated with SC-cytarabine or SC-daunorubicin for 40 days. Survival rates were recorded daily and in surviving mice, the prevalence of bone marrow proliferation after treatment was assayed by the crystal violet technique.

RESULTS

The assay on the time of establishment of leukemia shows that in 9 days leukemia cells accumulate in the bone marrow in sufficient quantities to sustain an in vitro culture in the absence of growth factors, and we, thus, used this as a criterion of well-established leukemia. When mice with a burden of leukemic cells of more than 9 days were treated with SC-cytarabine or SC-daunorubicin, this resulted in 55% survival for both treatments, and the proliferation assays showed that the bone marrow retained its normal proliferation capacity.

CONCLUSION

SC-cytarabine or SC-daunorubicin treatment prolonged the survival rate of Balb/c mice with a burden of well-established leukemia, and there was no negative impact on bone marrow functionality; however, SC-cytarabine or SC-daunorubicin combination options need to be sought to increase survival beyond 40 days.

Comparison of the efficacy of hematopoietic stem cell mobilization regimens: a systematic review and network meta-analysis of preclinical studies

BACKGROUND

Mobilization failure may occur when the conventional hematopoietic stem cells (HSCs) mobilization agent granulocyte colony-stimulating factor (G-CSF) is used alone, new regimens were developed to improve mobilization efficacy. Multiple studies have been performed to investigate the efficacy of these regimens via animal models, but the results are inconsistent. We aim to compare the efficacy of different HSC mobilization regimens and identify new promising regimens with a network meta-analysis of preclinical studies.

METHODS

We searched Medline and Embase databases for the eligible animal studies that compared the efficacy of different HSC mobilization regimens. Primary outcome is the number of total colony-forming cells (CFCs) in per milliliter of peripheral blood (/ml PB), and the secondary outcome is the number of Lin^- Sca1⁺ Kit⁺ (LSK) cells/ml PB. Bayesian network meta-analyses were performed following the guidelines of the National Institute for Health and Care Excellence Decision Support Unit (NICE DSU) with WinBUGS version 1.4.3. G-CSF-based regimens were classified into the SD (standard dose, 200-250 μg/kg/day) group and the LD (low dose, 100-150 μg/kg/day) group based on doses, and were classified into the short-term (2-3 days) group and the long-term (4-5 days) group based on administration duration. Long-term SD G-CSF was chosen as the reference treatment. Results are presented as the mean differences (MD) with the associated 95% credibility interval (95% CrI) for each regimen.

RESULTS

We included 95 eligible studies and reviewed the efficacy of 94 mobilization agents. Then 21 studies using the poor mobilizer mice model (C57BL/6 mice) to investigate the efficacy of different mobilization regimens were included for network meta-analysis. Network meta-analyses indicated that compared with long-term SD G-CSF alone, 14 regimens including long-term SD G-CSF + Me6, long-term SD G-CSF + AMD3100 + EP80031, long-term SD G-CSF + AMD3100 + FG-4497, long-term SD G-CSF + ML141, long-term SD G-CSF + desipramine, AMD3100 + meloxicam, long-term SD G-CSF + reboxetine, AMD3100 + VPC01091, long-term SD G-CSF + FG-4497, Me6, long-term SD G-CSF + EP80031, POL5551, long-term SD G-CSF + AMD3100, AMD1300 + EP80031 and long-term LD G-CSF + meloxicam significantly increased the collections of total CFCs. G-CSF + Me6 ranked first among these regimens in consideration of the number of harvested CFCs/ml PB (MD 2168.0, 95% CrI 2062.0-2272.0). In addition, 7 regimens including long-term SD G-CSF + AMD3100, AMD3100 + EP80031, long-term SD G-CSF + EP80031, short-term SD G-CSF + AMD3100 + IL-33, long-term SD G-CSF + ML141, short-term LD G-CSF + ARL67156, and long-term LD G-CSF + meloxicam significantly increased the collections of LSK cells compared with G-CSF alone. Long-term SD G-CSF + AMD3100 ranked first among these regimens in consideration of the number of harvested LSK cells/ml PB (MD 2577.0, 95% CrI 2422.0-2733.0).

CONCLUSIONS

Considering the number of CFC and LSK cells in PB as outcomes, G-CSF plus AMD3100, Me6, EP80031, ML141, FG-4497, IL-33, ARL67156, meloxicam, desipramine, and reboxetine are all promising mobilizing regimens for future investigation.

Improved Survival of Leukemic Mice Treated with Sodium Caseinate in Combination with Daunorubicin without Toxicity

In recent years, low doses of chemotherapy have been resumed and explored for the treatment of acute myeloid leukemia. Thus, CPX-351, a dual-drug liposomal encapsulation of cytarabine and daunorubicin, was approved by the US Food and Drug Administration, to deliver a synergistic 5 : 1 molar drug ratio into leukemia cells to a greater extent than normal bone marrow cells and significantly enhance survival compared with conventional treatment in older and newly diagnosed AML patients, but overall survival rate remains low; therefore, the need for new therapeutic options continues. Sodium caseinate (SC), a salt of casein, the main milk protein, has cytotoxic effect in leukemia cell lines, but promotes proliferation of hematopoietic normal cells, while its administration in leukemic mice promotes survival for more than 40 days, but bone marrow surviving mice still harbour leukemic cells, but it is not known whether the combination with cytarabine or daunorubicin can improve survival without damaging normal hematopoietic cells. Here, it is shown that, in vitro, the combination of the IC₂₅ of SC-cytarabine or SC-daunorubicin synergizes in the elimination of leukemic cells, with evident induction of apoptosis, while the proliferation of mononuclear cells of bone marrow is not affected. In leukemic mice, the combined administration of SC-daunorubicin or SC-cytarabine promotes the highest survival rate at 40 days; in addition, no autoproliferating cells were detected in the bone marrow of survivors of more than 60 days, evidence of eradication of leukemic cells, but only the bone marrow of mice treated with the SC-daunorubicin combination proliferated in the presence of interleukin-3, which shows that this combination is not toxic to normal bone marrow cells, thus emerging as a possible antileukemic agent.

El caseinato de sodio incrementa número de linfocitos B en ratones

Introducción. El caseinato de sodio, una sal de la caseína utilizada como agente proinflamatorio en ratones, es capaz de inducir granulopoyesis en vivo e incrementar la producción de citocinas esenciales en dicho evento.Objetivo. Evaluar si el caseinato de sodio es capaz de inducir un efecto biológico en células de origen linfoide y la producción de citocinas involucradas con este linaje.Materiales y métodos: Se utilizaron ratones hembra BALB/c de 8 a 12 semanas de edad. Los animales se inyectaron cuatro veces, con intervalos de 48 horas, por vía intraperitoneal con 1 ml de caseinato de sodio (10 % de SFB p/v). La población de linfocitos B y la incorporación de bromodesoxiuridina (BrdU) se analizaron mediante citometría de flujo. La detección de la interleucina 7 se evaluó mediante la técnica de ELISA.Resultados. Tras la inyección por vía intraperitoneal, el número de linfocitos B 220+ provenientes del bazo de ratones tratados con caseinato de sodio aumentó comparados con los que solo recibieron el vehículo como tratamiento (89,01±1,03 Vs. 75,66±2,08), así como la incorporación de BrdU en células B220+ (38,59±4,48 Vs. 11,82±1,04). Se evidenció, asimismo, el incremento en la concentración de la interleucina 7 (IL-7) en el suero de los ratones tratados con caseinato de sodio, comparados con los que solo recibieron el vehículo (62,1±17,5 Vs. 26,9±4,4 pg/ml).Conclusión. El caseinato de sodio fue capaz de aumentar el número de linfocitos B en bazo de ratones, así como inducir la producción de IL-7, citocina clave para la linfopoyesis B.