[Effectiveness and Mechanism of Decitabine Maintenance Therapy in Patients with Medium and Low-risk Acute Myeloid Leukemia].

OBJECTIVE: To investigate the efficacy and mechanism of decitabine maintenance therapy in patients with medium and low-risk acute myeloid leukemia(AML). METHODS: The newly diagnosed medium- and low-risk AML patients in the Second Affiliated Hospital of Anhui Medical University from December 2016 to December 2020 were retrospectively analyzed. Seventy-eight AML patients who were still in remission after consolidation treatment were divided into maintenance treatment group (31 cases) and control group (47 cases). The maintenance treatment patients received decitabine at 20 mg/m2 IV daily for 5 days, every three months for 6 cycles, the control group was only observed and tested regularly. Follow-up was completed by telephone or by viewing outpatient or inpatient medical records. Primary indicators were overall survival (OS), and secondary indicators include relapse-free survival (RFS), tolerance, cellular immune function and analysis of risk factors related to survival. RESULTS: Median RFS in maintenance theatment and control groups was 30.1(26.2-33.8) months and 24.3(21.7-30.3) months (P=0.011), median OS 34.7(29.8-39.7) months and 27.7(24.1-31.3) months respectively（P=0.024）, with a statistically significant difference. For the univariate and multivariate Cox regression analysis, only the minimal residual disease (HR=25.185, P<0.001) and the treatment methods (HR=0.124, P<0.001) affected the PFS and OS of patients. In the maintenance treatment group, CD3+T cells, CD8+T cells and NK cells increased significantly after decitabine maintenance treatment, and the regulatory T cells decreased significantly (P<0.05). Patients had a low incidence of grade 3-4 adverse events, hematological adverse events were mainly neutropenia and thrombocytopenia, non-hematological adverse events were mainly digestive tract symptoms, and the patient was well tolerated. CONCLUSION: Maintenance treatment with decitabine provided benefit survival in patients with medium- and low-risk AML and is well tolerated. The mechanism may be inhibition the proliferation of regulatory T cells, induce and enhance the cytotoxic effect of CD8+ T cells on tumor antigens.

[A Real-World Study of the Effect of rhG-CSF on Clinical Efficacy and Flow Cytometry MRD after Initial Induction Therapy for Acute Myeloid Leukemia].

OBJECTIVE: To investigate the effect of recombinant human granulocyte colony stimulating factor (rhG-CSF) on the clinical efficacy and flow cytometry (FCM) minimal residual disease (MRD) of patients with acute myeloid leukemia (AML) after initial induction therapy in the real world. METHODS: The clinical data of 44 AML patients who were diagnosed for the first time in the Department of Hematology, The Second Hospital of Anhui Medical University, and received the initial induction therapy were retrospectively analyzed. According to whether rhG-CSF was used after treatment, these patients were divided into control group and therapy group. The complete remission (CR) rate, duration of neutropenia, incidence of infection, duration of fever, cost of antibiotics drugs, length of hospital stay, FCM MRD, and relapse-free survival (RFS) time were compared between the two groups. RESULTS: The CR rate in the control group was 60%, and 74% in the therapy group (P=0.3429). The duration of neutropenia was (21.28±7.91) days in the control group and (14.79±3.07) days in the therapy group (P=0.0016). The duration of fever was (12.80±7.31) days in the control group and (9.11±7.48) days in the therapy group (P=0.0136). While, there were no statistically significant differences between the two groups in the incidence of infection, cost of antibacterial drugs, length of hospital stay and RFS time (all P>0.05). In addition, it is particularly noteworthy that among the patients who finally obtained CR in the therapy group, 66% of them had myeloid precursor cells detected by peripheral blood FCM (accounting for 2.25%±0.99%) at the time of the first release of neutropenia, which was easy to be misdiagnosed as MRD positive. CONCLUSION: rhG-CSF not only don't affect the clinical remission rate after the initial induction treatment of AML, but also significantly shortens the time of duration of neutropenia and fever, however, it may affect the analysis of peripheral blood FCM MRD detection results when the neutropenia is released for the first time.

[The First Switched Time of PML/RARα Fusion Gene in Patients with Acute Promyelocytic Leukemia and Its Clinical Significance].

OBJECTIVE: To investigate the first switched time of PML/RARα fusion gene in patients with acute promyelocytic leukemia (APL) and its clinical significance. METHODS: sixty cases of newly diagnosed APL were enrolled in this study. They received standard remission induction, consolidation and maintenance treatments according to the clinical pathway for APL, and were followed up. During the same time the PML/RARα fusion gene mRNA expression of all cases was detected by multi-nested PCR. RESULTS: except for 3 death cases and 1 case failed to follow-up, the PML/RARα fusion genes in the remaining 56 cases were firstly found to be negative from 24 to 381 days respectively, the mean value of the first switched time was 131 ± 90 days. There was no statistically significant difference in age, sex and risk stratification between different groups. However, the cases with L-type PML/RARα gene had shorter time compared with the patients with S-type PML/RARα gene (P = 0.032); then, for the above-mentimed 56 cases, the follow-up duration ranged from 25-1979 days (median 946 days), long-term molecular remissions had been observed in most cases, but 1 case with the first switched time of 133 days unfortunately recurred to be positive and followed by clinical relapse. CONCLUSION: The PML/RARα fusion gene in newly diagnosed APL patients was first switched to be negative in about 4 months after treatment. The first switched time of PML/RARα fusion gene can objectively reflect the reduction of leukemia cells, and the differences among different subtypes of PML/RARα fusion gene may have some suggestions for the treatment, but without important significance for the evaluation of prognosis and recurrence for APL patients. In addition, minimal residual disease (MRD) can be dynamically monitored by detecting PML/RARα fusion gene, thus having an important clinical significance for analysis of APL recurrence.

[Correlation of the Desialylation of Platelets with Efficacy of the First-line Therapy for ITP].

OBJECTIVE: To detect desialylation of platelets in primary immune thrombocytopenia(ITP) patients with FITC-labelled ECL and RCA-1, and compare the correlation of the desialylation level and the efficacy of first-line therapy for ITP. METHODS: Before treatment, 48 ITP patients were selected and their levels of ECL and RCA-1 were detected with flow cytometry. RESULTS: The desialylation level in the different efficacy groups by using the first-line therapy of corticosteroids and (or) intravenous immunoglobulin G (IVIG) had a statistically significant difference (P<0.05). The correlation analysis showed negative relation of the therapeutic efficacy with desialylation level, that is to say, the more high of desialylation level, the more poor therapeutic efficacy of the first-line therapy. CONCLUSION: The desialylation level of platelets in ITP patients is related with the first-line therapeutic efficacy, the efficacy for patients with high desialylation level is poor, suggesting that the FcR-independent pathway exists in clearance of platelets in ITP patients. Therefore, the desialylation level of platelets may suggest the first-line therapeutic efficacy for ITP patients to a certain degree, and may be used as a potential target for the treatment of refractory ITP.

Interleukin-6 up-regulates the expression of interleukin-15 is associated with MAPKs and PI3-K signaling pathways in the human keratinocyte cell line, HaCaT.

Interleukin (IL)-15 is an important inflammatory cytokine and plays a key role in autoimmune disease. At present, IL-15 gene expression and regulation related to many innate immunity trigger signals have been clarified in some specific cell types, but the relationship of IL-6 and IL-15 in the human keratinocyte cell line (HaCaT) is unknown. In this study, we investigated the effect of IL-6 on the expression of IL-15 and selected signaling pathways in HaCaT cells. Results demonstrated that IL-6 up-regulated the expression of IL-15 both at the mRNA and protein levels. Meanwhile, IL-6 was able to activate MAPKs-ERK1/2 and PI3K-AKT signaling pathways. Furthermore, the high expression of IL-15 induced by IL-6 was down-regulated while MAPKs-ERK1/2 and PI3K-AKT signaling pathways were, respectively, blocked by PD98059 and LY294002. These findings indicate that the expression of IL-15 up-regulated by IL-6 is associated with MAPKs-ERK1/2 and PI3K-AKT signaling pathways in HaCaT cells.

IL-29 and IFN-α regulate the expression of MxA, 2',5'-OAS and PKR genes in association with the activation of Raf-MEK-ERK and PI3K-AKT signal pathways in HepG2.2.15 cells.

Interferons (IFNs) can activate the PI3K-AKT and Raf-MEK-ERK signal pathways and induce antiviral proteins (MxA, 2',5'-OAS and PKR) expression in specific cell lines. However, the relationship between those antiviral proteins expression and signal pathways remains unknown at present. Thus our experiments were designed to determine the exact relationship in HepG2.2.15 cell line. The results demonstrated that IFN-α and IL-29 were both able to activate PI3K-AKT and Raf-MEK-ERK signal pathways, and IFN-α up-regulated the expression of MxA, 2',5'-OAS and PKR whereas IL-29 increased mRNA expression of MxA and 2',5'-OAS and had no influence on PKR. Furthermore, MxA, 2',5'-OAS and PKR expression were down-regulated while PI3K-AKT signal pathway was blocked by LY294002. And MxA was up-regulated after Raf-MEK-ERK signal pathway being blocked by PD98059. These findings indicate that the expression of MxA, 2',5'-OAS and PKR are up-regulate by PI3K-AKT signal pathway, and Raf-MEK-ERK signal pathway has a negative regulatory effect on the expression of MxA and no significant effect on 2',5'-OAS and PKR.

[N-acetylcysteine antagonizes the Interleukin-18-induced expression of TNF-alpha and IL-6 in mouse vascular smooth muscle cells].

AIM: To explore the effect of N-acetylcysteine(NAC)on the interleukin(IL)18-induced expression of tumor necrosis factor (TNF) alpha and interleukin(IL) 6 in mouse vascular smooth muscle cells(VSMC). METHODS: VSMC was stimulated with various concentrations of IL-18 for different times after addition of NAC(5 mmol/L) for 1 h. The messenger ribonucleic acid(mRNA) expression of TNF-alpha and IL-6 was measured by RT-PCR and the protein secretion of the two cytokines was determined by ELISA method. Western blot was used to analyze the activation of NF-kappaB in VSMC. RESULTS: IL-18 significantly increased the mRNA expression and protein secretion of TNF-alpha and IL-6 (P>0.01) in a dose-dependent and a time-dependent ways. NAC inhibited the mRNA expression and protein secretion of TNF-alpha and IL-6 induced by IL-18(P>0.01). Western blot results showed the NAC inhibited the IL-18-induced activation of NF-kappaB in VSMC. CONCLUSION: N-acetylcysteine antagonizes the production of TNF-alpha and IL-6 induced by IL-18 in VSMC.