The Significance Of CD44 In Extramedullary Infiltrations Of Leukemia Cells

1,Clinical Analysis of 110 Cases of Adult Central Nervous System Leukemia Objective To discuss the clinical features and prognosis of adult central nervous system leukemia (CNSL). Methods Retrospective analysis was used to evaluate clinical data of 110 cases of adult patients with CNSL. Results In these 110 cases of adult CNSL patients, 57 cases were ALL patients, 42 cases were AML patients, 11 cases were patients with other types of leukemia. 81 patients (73.6%) were younger than 40 years old; the initial WBC count of 47 patients (42.8%)were higher than 30×109/L; Karyotype analysis showed that 75 patients(81.5%) belonged to the medium or high risk group; and 51 patients (46.4%)were in CR1 period.24 patients (21.8%) relapsed CNSL twice or more; 42 patients(38.2%)suffered systemic relapse once,twice or three times before, upon or after CNSL emergence. Survival analysis suggested a median survival time was (16.0±3.2) months and the survival rate over 5-year was (24.4±5.5)%. Conclusion The Adult CNSL occurred at a considerable incidence and was in association with leukemia types, age, initial WBC, karyotype subgroup, disease course. The CNSL and systemic leukemia recurrence often occurs at the same time. The onset of CNSL always affect the long-term survival and prognosis of patients, which calls more attention for the prevention and treatment of it.2,The Influence of CD44 on the Adhesive, Migratory and Infiltrative Abilities of Leukemia CellsObjective To detect the expression of CD44 in leukemia cell lines and its role in adhesion,migration and invasion of leukemia cells. Methods The expression levels of CD44 in four leukemia cell lines—SHI-1,THP-1,NB4 and K562 were investgated by reverse transcription-polymerase chain reaction(RT-PCR) when they were in logarithmic phase. The assay of cell-cell adhesion,transendothelial migration and invasion were performed. Results CD44 was expressed in SHI-1, THP-1, NB4 cells, while hard to be detected in K562 cells(P<0.01). Cell-cell adhesion assay showed,after pretreatment with CD44 monoclonal antibody,the adhesion ability of SHI-1, THP-1 and NB4 cells decreased to a lower degree than that of the control group, in particular for NB4 cells. Compared with K562 cells, the transendothelial and invasive abilities of SHI-1, THP-1 and NB4 cells were stronger, and these abilities could be attenuated by CD44 monoclonal antibody. The highest expression level of CD44 were detected in NB4 cells, and its adhesive, migratory and infiltrative abilities were attenuated most markedly by CD44 monoclonal antibody. Conclusion CD44 might play an important role in the adhesion,migration and invasion of leukemic cells and be involved in the extramedullary infiltration of leukemia cells. 3,Detection of Soluble CD44 in Cerebrospinal Fluid of Patients with Acute Leukemia and its Implication to Central Nervous System LeukemiaObjective To observe the roles of soluble CD44 in cerebrospinal fluid in diagnosis of central nervous system leukemia (CNSL).Methods Enzyme-linked immunosorbent assay(ELISA)was employed to determine soluble CD44 in cerebrospinal fluid of patients with CNSL,without CNSL and control group.Results The mean concentration of soluble CD44 in cerebrospinal fluid of CNSL group both before CNSL and at the time of CNSL was significantly higher than that of no CNSL and normal group(P< 0.01;P< 0.05). The concentration of sCD44 also decreased significantly after complete remission compared with that of both before CNSL and at the time of CNSL(P< 0.05;P< 0.05).Conclusion Soluble CD44 in cerebrospinal fluid may play an important role in the occurrence of CNSL.Detection of soluble CD44 level in cerebrospinal fluid, combined with routine examination,may be helpful to make an early diagnose of CNSL.