Proteome Analysis of Adult Acute Lymphoblastic Leukemia by Two-dimensional Blue Native/Sodium Dodecyl Sulfate Gel Electrophoresis

Background

Despite the significant progress in the treatment of Acute Lymphoblastic Leukemia (ALL) in children, it still remains as one of the most challenging malignancies in adults. Identification of new biomarkers may improve the management of adult ALL. Proteins expressed on the cell surface can be considered as disease-associated biomarkers with potential for diagnosis and targeted therapies. Thus, membrane proteome studies give essential information about the disease-related biomarkers.

Methods

We applied 2-dimensional blue-native SDS-PAGE technique followed by MALDI-TOF/TOF-mass spectrometry to study the cell membrane proteome of peripheral blood mononuclear cells of adult B-ALL patients in comparison to that of the healthy controls.

Results

Sixty seven differentially expressed protein spots were detected, among them 52 proteins were found to be up-regulated but the other 15 proteins were down-regulated in B-ALL. Five differentially expressed proteins, involved in energy metabolism pathways, were detected in B-ALL patients compared to the healthy control group.

Conclusion

Differentially expressed proteins provide an insight into the molecular biology of B-ALL. Further studies must be done to confirm our data to be considered as potential targets for detection and treatment of B-ALL.

Cyclic pamidronate therapy in children with osteogenesis imperfecta

BACKGROUND

Severe osteogenesis imperfecta (OI) is a disorder characterized by osteopenia, frequent fractures, progressive deformity, loss of mobility, and chronic bone pain. There has been no effective therapy for the disorder until recently. The main objective of this study was to determine the efficacy and safety of pamidronate in improving bone mineralization and reducing fracture incidence in osteogenesis imperfecta.

METHODS

Intravenous pamidronate was administered to 64 children (from 21 months to 10 years old) with severe OI, in a 1 mg/kg single daily dose for 3 sequential days at 4-month intervals, over 24-48 months duration. Clinical status, biochemical characteristics including bone turnover markers, bone mineral density of the lumbar spine and femoral neck, and radiological changes were assessed regularly during treatment.

RESULTS

The number of fractures decreased from a median of 8 (range 4-11) to 0 fractures/year (range 0-4) (p <0.05). After 16 months of treatment, there was significant improvement in bone mineral density (BMD-DEXA) z-score of the lumbar spine from a median of -5.90 (range -7.01 to -4.76) to -2.70 (range -4.46 to -1.98) (p <0.001). Serum alkaline phosphatase (ALP) (bone formation marker) decreased from a median of 731.0 U/l (range 438-998 U/l) to 183 U/l (range 95-286 U/l) (p <0.001), implying a significant reduction in bone turnover and resorption and increase in bone mineralization. There was no improvement in growth velocity or height SDS. Mobility and ambulation improved in all but five children (all five had taken the drug for less than 2.5 years). There was a significant relief of chronic pain and fatigue but no adverse effects in all children using the drug.

CONCLUSION

Cyclic pamidronate administration is effective in improving bone mineralization and reducing fracture incidence in childhood osteogenesis imperfecta.