Clinical summary of pediatric acute lymphoblastic leukemia patients complicated with asparaginase-associated pancreatitis in SCCLG-ALL-2016 protocol

Asparaginase-associated pancreatitis (AAP) is a common and fatal complication after ASNase treatment in acute lymphoblastic leukemia(ALL). Here, a total of 1063 pediatric ALL patients treated with SCCLG-ALL-2016 regimen were collected since October 2016 to June 2020, including 35 patients with AAP. The clinical characteristics of AAP and non-AAP patients were compared. In AAP patients, the possible factors that affected the recurrence of AAP were analyzed, and the possible risk factors related to ALL-relapse were discussed. The results showed that age was a risk factor (P = .017) that affect the occurrence of AAP. In AAP patients, AAP tended to develop after the second use of PEG-ASNase (25.71%). In the follow-up chemotherapy, 17 patients re-exposed to ASNase and 7 cases developed AAP again with a percentage was 41.2%. There were no special factors that related with the recurrence of AAP. This study also found no association between the occurrence of AAP and prognosis of ALL, with the 4-year incidence of ALL relapse in AAP and non-AAP patients were 15.9% v.s.11.7% (HR: 1.009, 95% CI:0.370-2.752, P = .986), and there were no special factors that related with the ALL relapse among AAP patients. Based on the above results, the occurrence of AAP is related to age and should be vigilant after the second use of PEG-ASNase after use in pediatric ALL patients. Moreover, AAP is not associated with ALL relapse, but there is a high AAP recurrence rate when re-exposure to ASNase.

[Effects of minimal residual disease level on day 33 of remission induction and IKZF1 genotype on the survival of children with B-lineage acute lymphoblastic leukemia]

OBJECTIVE

To study the effects of minimal residual disease (MRD) level on day 33 of remission induction and IKZF1 genotype on the survival of children with B-lineage acute lymphoblastic leukemia (B-ALL).

METHODS

A total of 152 children with newly-diagnosed B-ALL who had complete remission after the first cycle of the chemotherapy and had complete follow-up information were enrolled in this study. According to the MRD detection by flow cytometry on day 33 of remission induction, they were divided into three groups: standard-risk (SR) group (MRD <10^-4; n=60), intermediate-risk (IR) group (10^-4≤ MRD <10^-2; n=55), and high-risk (HR) group (MRD ≥10^-2; n=37). Nested RT-PCR was used to determine the IKZF1 genotype of all children before chemotherapy. The effects of MRD level on day 33 of remission induction and IKZF1 genotype on the recurrence-free survival (RFS) of children with B-ALL were analyzed.

RESULTS

There were 7 common IKZF1 subtypes in all the 152 children with B-ALL: IK1, IK2/3, IK4, IK6, IK8, IK9, and IK10. Of the 152 children, 130 had functional subtypes of IKZF1 and 22 had non-functional subtypes of IKZF1. During the follow-up period, relapse occurred in 26 (17%) children, and the recurrence rate was highest in the HR group (P<0.05). However, there was no significant difference in the recurrence rate between the SR group and the IR group (P>0.05). The cumulative recurrence rate of the children with non-functional subtypes of IKZF1 was significantly higher than that of those with functional types of IKZF1 (P<0.01). The predicted 5-year RFS rates in the SR, IR, and HR groups were (94.2±2.9)%, (86.7±3.8)%, and (56.2±4.5)% respectively (P<0.05). The 5-year RFS rate of the children with functional subtypes of IKZF1 was significantly higher than that of those with non-functional subtypes of IKZF1 (P<0.01). There was no significant difference in the predicted 5-year RFS rate between the children with functional subtypes of IKZF1 and those with non-functional subtypes of IKZF1 in the SR group (P>0.05). However, the predicted 5-year RFS rate of the children with functional subtypes of IKZF1 was significantly higher than that of those with non-functional subtypes of IKZF1 in the IR group and the HR group (P<0.05).

CONCLUSIONS

B-ALL children with non-functional subtypes of IKZF1 have a high recurrence rate, and the recurrence rate will be even higher in B-ALL children with non-functional subtypes of IKZF1 and MRD ≥10^-4 on day 33 of chemotherapy.

[Effect of Icaritin on Proliferation and Apoptosis of THP-1 Cell and Its Mechanism]

OBJECTIVE

To investigate the effect of icaritin on the proliferation and apoptosis of THP-1 cells and its mechanism.

METHODS

After treated with various concentrations of icaritin, cell proliferation was detected by MTS method, and apoptosis was measured with flow cytometry and Hoechst 33258 staining. Expression of BCL-2, BAX and Caspase-3 protein in THP-1 cell was detected by Western blot.

RESULTS

After treatment with various concentrations (4-32 µmol/L) of icaritin for 24, 48, 72 h, the inhibition rate of cell growth significantly increased (P<0.05) in time-dose dependent manner(r=0.946); and the apoptotic rate of cells significantly increased (P<0.05) in time-dose dependent manner(r= 0.924). The expression of BCL-2 protein at 48 h decreased significantly in icaritin-treated group, compared with that in control group (P<0.05), while the expression of BAX and Caspase3 protein at 48 h increased significantly in icaritin-treated group, compared with that in control group (P<0.05).

CONCLUSION

Icaritin can inhibit proliferation and induce apoptosis of THP-1 in vitro, Icaritin may induce apoptosis in THP-1 cells through the mitochondrial pathway.

[Effect of glucocorticoid on dendritic cells in children with chronic immune thrombocytopenia]

OBJECTIVE

To investigate the change in dendritic cells (DCs) in children with chronic immune thrombocytopenia (cITP) and the effect of glucocorticoid on DCs in children with cITP.

METHODS

Fifteen children with cITP and 20 healthy controls were included in the study. Flow cytometry was used to measure the DC subsets count in the 15 children with cITP before and after glucocorticoid treatment as well as the corresponding values in the 20 healthy controls. The DCs derived from peripheral blood monocytes in children with cITP were cultured in vitro and collected, and their immunophenotypes were determined by flow cytometry.

RESULTS

Before glucocorticoid treatment, the children with cITP showed no notable change in the absolute count of myeloid DCs (mDCs) but showed decreased absolute count of plasmacytoid DCs (pDCs) and increased mDC/pDC ratio compared with the healthy controls (P<0.05). After glucocorticoid treatment, the children with cITP demonstrated increased absolute count of pDCs and decreased absolute count of mDCs and mDC/pDC ratio compared with before treatment (P<0.05). Before glucocorticoid treatment, the children with cITP had significantly higher positive rates of HLA-DR, CD80, CD83 and CD86 on peripheral blood DCs than the healthy controls (P<0.01). All the positive rates were significantly decreased after glucocorticoid treatment (P<0.01), so that there was no significant difference from the healthy controls (P>0.05).

CONCLUSIONS

Disproportion and functional disturbance of DC subsets is associated with the pathogenesis of cITP in children. Glucocorticoid can strengthen the immunosuppression of DCs in children with cITP, which may contribute to the effectiveness of glucocorticoid as a treatment.

Down-regulation of mitochondrial ATPase by hypermethylation mechanism in chronic myeloid leukemia is associated with multidrug resistance

BACKGROUND

To identify novel proteins involved in multidrug resistance in chronic myeloid leukemia (CML).

MATERIALS AND METHODS

Comparative proteomics was used to screen multidrug resistance-related proteins from K562 and K562/A02; the differently expressed proteins were further confirmed by western blot and real-time PCR. short hairpin RNA (shRNA) assay was applied to determine the relationship between candidate protein and adriamycin resistance. Bisulfite sequencing was carried out to assess methylation status of candidate multidrug resistance-related gene promoter. K562/A02 was treated with 5-azacytidine or trichostatin A (TSA); multidrug resistance phenotype and corresponding protein or gene changes were detected.

RESULTS

Seventeen proteins with altered abundances of more than twofold were detected, among which mitochondrial ATPase in K562/A02 was significantly down-regulated. Suppressing mitochondrial ATPase by shRNA could enhance adriamycin resistance and antiapoptosis activity of K562. The promoter hypermethylation in mitochondrial ATPase was found to be attributed to the adriamycin-resistant phenotype of both K562/A02 (methylated frequency 18.18%) and CML primary cells in accelerated phase (methylated frequency 7.95%) or blast crisis (methylated frequency 26.59%). Inhibition of hypermethylation increased adriamycin sensitivity of K562/A02. A synergistic effect on reversing adriamycin-resistant phenotype was obtained when 5-azacytidine was combined with TSA.

CONCLUSION

Down-regulation of mitochondrial ATPase can lead to adriamycin resistance in CML and the mechanism is associated with DNA methylation regulation.

[In vitro expansion of the adult human bone marrow mesenchymal stem cells for clinic application in HSCT]

This study was aimed to investigate the efficiency of 4 different culture media for in vitro culture and expanding adult human bone marrow mesenchymal stem cells (ahBM-MSCs) so as to establish a protocol of culturing and expanding hBM-MSCs and provide exprimental basis for hematopoietic blood stem cell transplantation combined with BM-MSCs. BM-MSCs were obtained from 16 fresh adult human bone marrow aspirate by gradient centrifugation with Ficoll Paque, then cultured in DMEM/F12 with 10% umbilical cord blood serum, 10% fetal calf serum (FCS), human blood serum, and MesenCult culture medium. The surface antigens of BM-MSCs were detected by flow cytometry. BM-MSCs were differentiated into osteoblasts and adipocytes under culture in the conditioned medium special for osteogenesis, and adipogenesis and the differentiated MSCs were identified by morphological observation, immunophenotype and immunohistochemical staining. The results showed that BM-MSCs could be isolated from adult human bone marrow and cultured by all culture media. The effect of umbilical cord blood serum on BM-MSC proliferation and their purity were similar to that of MesenCult culture medium, but better than that of FCS and human blood serum. The positive rate of CD29, CD73, CD105 on BM-MSCs cultured in umbilical cord serum and MesenCult medium was higher than that in FCS and adult human serum (p < 0.05), and the positive rate of CD31 was lower than that in FCS and adult human serum (p < 0.05). The positive rate of BM-MSCs differentiated into osteoblasts and adipocytes under culture in the conditioned medium for osteogenesis and adipogenesis with umbilical cord blood serum and MesenCult culture medium was also higher than that in FCS and adult human serum (p < 0.05). It is concluded that BM-MSCs can be obtained by all the four methods. DMEM/F12 with 10% umbilical cord blood serum and MesenCult culture medium are better than the others for the purification and differentiation potency of BM-MSCs in vitro. The medium with umbilical cord serum is valuable for clinical application in HSCT.

[Expression characteristics of heat shock protein 70 and pim-1 gene in bone marrow mononuclear cells from leukemia patients and their clinical significance]

This study was aimed to investigate the expression characteristics of HSP70 protein/mRNA, pim-1 mRNA in bone marrow mononuclear cells from leukemia patients, and to clarify whether these changes are related to leukemia type, tumor burden of leukemia, therapeutic reaction and prognosis. HSP70 mRNA and pim-1 mRNA in BMMNCs were detected with semi-quantitative RT-PCR in 40 leukemia patients and 10 controls. HSP70 protein in BMMNCs was assayed with Western blot in 34 leukemia patients and 10 controls. Relation of HSP70 and pim-1 expression with leukemia classification, the degree of tumor burden and therapeutic reaction were analyzed. The results showed that the BMMNCs from both leukemia patients and controls expressed HSP70 protein/mRNA. The mean ODR value of HSP70 mRNA in BMMNCs from leukemia patients was significantly higher than that of the controls; the mean ODR value of HSP70 protein/mRNA in acute myeloid leukemia and chronic myeloid leukemia patients both were significantly higher than that of acute lymphocytic leukemia patients; the mean ODR value of HSP70 protein/mRNA in acute leukemia patients with high-degree tumor burden was higher than that of the patients with low-degree tumor burden; the mean ODR value of HSP70 protein/mRNA in the patients after chemotherapy was significantly higher than that of the patients before chemotherapy; the BMMNCs from both leukemia patients and controls expressed pim-1 mRNA. The mean ODR value of pim-1 mRNA in BMMNCs from leukemia patients was significantly higher than that of the controls; the mean ODR value of pim-1 mRNA in BMMNCs for Acute lymphocytic leukemia patients was significantly higher than that of the patients suffered from acute myeloid leukemia and chronic granulocytic leukemia; there was a positive relationship between pim-1 mRNA and HSP70 mRNA expressions in leukemia patients (p < 0.05). It is concluded that there are high expressions of HSP70 and pim-1 in leukemia and their positive correlation is shown. The over-expressions of HSP70 and pim-1 protein/mRNA are related to tumor burden in leukemia patients.