Bioinformatics analysis of the network of histone H3 lysine 9 trimethylation in acute myeloid leukaemia.

Changes in histone H3 lysine 9 trimethylation (H3K9me3) may be related to the development of drug­resistant acute myeloid leukaemia (AML); insights into the network of H3K9me3 may improve patient prognosis. Patient data were derived from the Gene Expression Omnibus (GEO) database and data from AML cells treated with chidamide, a novel benzamide chemical class of histone deacetylase inhibitor (HDACi), in vitro were derived from ChIP­seq. Patients and AML cell data were analysed using GEO2R, GOseq, KOBAS, the STRING database and Cytoscape 3.5.1. We identified several genes related to the upregulation or downregulation of H3K9me3 in AML patients; some of these genes were related to apoptosis, autophagy, and the pathway of cell longevity. AML cells treated with chidamide in vitro showed the same gene changes. The protein interactions in the network did not have significantly more interactions than expected, suggesting the need for more research to identify these interactions. One compelling result from the protein interaction study was that sirtuin 1 (SIRT1) may have an indirect interaction with lysine­specific demethylase 4A (KDM4A). These results help explain alterations of H3K9me3 in AML that may direct further studies aimed at improving patient prognosis. These results may also provide a basis for chidamide as a treatment strategy for AML patients in the future.

Chidamide Enhances the Cytotoxicity of Cytarabine and Sorafenib in Acute Myeloid Leukemia Cells by Modulating H3K9me3 and Autophagy Levels.

Previous studies showed that chidamide enhances the cytotoxicity of drugs in acute myeloid leukemia (AML) cells. Therefore, we examined whether chidamide enhanced the cytotoxicity of drugs in AML cells by affecting H3K9me3 and autophagy levels. AML cells (THP-1 and MV4-11 cells) were treated with chidamide, cytarabine (Ara-c), or sorafenib alone or in combination. Cell proliferation and survival rates were analyzed by MTT, flow cytometry, and Western blotting assays. The results showed that a low dose of chidamide enhanced the cytotoxicity of Ara-c or sorafenib in AML cells, decreasing proliferation and increasing apoptosis. H3K9me3 levels as assessed by Western blotting were upregulated by chidamide treatment. Chromatin immunoprecipitation sequencing, which was used to investigate potential signaling pathways, indicated that the autophagy pathway might play a role in the effects of chidamide. The level of autophagy induced in AML cells upon treatment with Ara-c or sorafenib was inhibited by chidamide, and autophagy markers (LC3, P62) were tested by Western blotting. SIRT1 messenger RNA (mRNA) and protein levels were lower in AML cells treated with Ara-c or sorafenib in combination with chidamide than those in cells treated with these drugs alone. Additionally, the Integrative Genomics Viewer results indicate that the H3K9me3 changes were related to SIRT1-binding sites. Together, these results show that chidamide enhances the cytotoxicity of two chemotherapy drugs in AML cells by increasing the H3K9me3 level and inhibiting autophagy via decreasing the expression of SIRT1. Chidamide may be a potential treatment strategy for AML in the future, especially for refractory AML patients.

The change of nuclear LC3 distribution in acute myeloid leukemia cells.

Making sure the change of nuclear LC3 distribution in the autophagy of acute myeloid leukemia (AML) cell and finding out the regulation mechanism may lead to a breakthrough for killing AML cells. Western blots were performed to assess the expression of autophagy proteins. Changes in the LC3 distribution were monitored by immunofluorescence assays together with western blots, and the expression levels of Sirt1, DOR, Beclin1, HMGB1, and AMPK mRNA were detected via fluorescent quantitative PCR. The effects of Sirt1 and DOR on cell proliferation and survival were analyzed by MTT, flow cytometry, and western blotting assays. We found that treating AML cells with Ara-c or Sorafenib resulted in autophagy enhancement, and when autophagy was enhanced, nuclear LC3 moved into the cytoplasm. Notably, when autophagy was inhibited by blocking the nuclear LC3 shift, the cytotoxicity of drugs was enhanced. Our results also identified Sirt1 and DOR as regulatory molecules for the observed nuclear LC3 shift, and these molecules further affected the expression of Beclin1, HMGB1, and AMPK. Our results suggest the distribution of nuclear LC3 can be a novel way for further studying death of AML cells,and the regulatory molecules may be new targets for treating AML.

A Meta-Analysis for Effects of Elevated Pre-Transplantation Serum Ferritin on the Outcomes in Patients Undergoing Hematopoietic Stem Cell Transplantation.

The level of pre-transplantation serum ferritin (SF) is one of the factors related to outcome for patients undergoing allogeneic hematopoietic stem cell transplantation. We searched PubMed and Cochrane Library databases from 2000 to 2014. The primary efficacy outcome was overall survival rate and non-relapse mortality. Twenty clinical trials were selected from 189 studies identified. The combined hazard ratio indicated a significantly lower overall survival rate and a higher non-relapse mortality rate in patients with elevated SF before transplantation. This indicates that elevated pre-transplantation SF affects outcome in patients undergoing allogeneic hematopoietic stem cell transplantation.

Role of caspase-10 in the death of acute leukemia cells.

Autophagy can protect cells from stress, but can also induce cancer cell death. Caspase-10 is now considered to be a factor that is associated with autophagy in cancer. The present study therefore investigated whether caspase-10 affects autophagy in acute leukemia cells. The rates of survival vs. apoptosis in acute leukemia HL-60 and Jurkat cells treated with drugs were tested using cell viability assays and flow cytometry, and the levels of caspase-3 and -10 were tested by western blotting. In HL-60 cells that were treated with chemotherapy drugs combined with a caspase-10 inhibitor, the rate of survival decreased significantly compared with HL-60 cells treated with chemotherapy drugs alone. In contrast, the rate of survival of Jurkat cells treated with chemotherapy drugs combined with the caspase-10 inhibitor increased significantly compared with Jurkat cells treated with chemotherapy drugs alone. The results of the flow cytometry and western blotting showed that the changes in the survival rate may be caused by a change in the amount of apoptosis occurring in the Jurkat cells treated with chemotherapy drugs combined with the caspase-10 inhibitor. However, in HL-60 cells undergoing this combination treatment, the change in the survival rate was not caused by a change in the rate of apoptosis. When HL-60 cells were treated with the chemotherapy drugs combined with the caspase-10 inhibitor and the autophagy inhibitor 3-methyl adenine, the survival rate increased, whereas the rate of apoptosis did not change. These results show that caspase-10 may be associated with autophagy in acute myeloid leukemia cells, but not in acute lymphatic leukemia cells.

CD1d levels in peripheral blood of patients with acute myeloid leukemia and acute lymphoblastic leukemia.

The antitumor effect of natural killer T cells has been reported in several studies analyzing the expression of CD1d on antigen-presenting cells (APCs). Therefore, the present study questioned whether APCs may be abnormal in the peripheral blood (PB) of acute leukemia (AL) patients, particularly the levels of CD1d. To improve the understanding of the role of CD1d on APCs, the levels of CD1d on monocytes were analyzed in healthy controls, AL patients and AL patients with complete remission (CR). In addition, the correlation between the number of CD3+CD56+ T lymphocytes and levels of CD1d on monocytes was analyzed. Flow cytometry was used to determine the levels of CD1d on monocytes and lymphocytes. A significant decrease was observed in the levels of CD1d on monocytes in the PB of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) patients compared with the healthy controls. Simultaneously, significantly different levels of CD1d on monocytes were identified between the CR-AML and the CR-ALL patients; the levels of CD1d on monocytes remained low in the CR-AML patients, while the levels of CD1d on monocytes recovered in the CR-ALL patients. A significantly negative correlation was observed between the number of CD3+CD56+ T lymphocytes and the levels of CD1d on monocytes in AL patients. However, a significantly positive correlation was identified between the cytotoxicity of the CD3+CD56+ T lymphocytes and the levels of CD1d on monocytes. These results suggested that the significantly low levels of CD1d on monocytes may contribute to AML and ALL progression. In addition, a significant correlation was observed between the levels of CD1d on monocytes and the number/cytotoxicity of CD3+CD56+ T lymphocytes in AML and ALL patients.

Numbers and cytotoxicities of CD3+CD56+ T lymphocytes in peripheral blood of patients with acute myeloid leukemia and acute lymphocytic leukemia.

Recent reports have highlighted the role of cellular immunity in anti-tumor defenses. T lymphocytes are known to play important part in anti-cancer immunity. The number and function of T lymphocytes are altered in chronic leukemia patients. CD3(+)CD56(+) T lymphocytes have also been found to be abnormal in cancer patients. We therefore investigated changes in the number and cytotoxicity of CD3(+)CD56(+) T lymphocytes in the peripheral blood of acute leukemia (AL) patients (excluding acute promyelocytic leukemia), to improve our understanding of the role of this T lymphocyte subset. We analyzed CD3(+)CD56(+) T lymphocyte numbers and cytotoxicities in healthy controls, AL patients, and AL patients with complete remission. Lymphocyte counts were performed in peripheral blood and flow cytometry was used to determine cell numbers and cytotoxicities. The absolute number of CD3(+)CD56(+) T lymphocytes was increased in AL patients (including acute myeloid [AML] and acute lymphocytic leukemia [ALL]) compared with healthy controls (P<0.05), but their functioning was significantly reduced (P<0.05). The number of CD3(+)CD56(+) T lymphocytes in AML and ALL patients who achieved remission following chemotherapy was close to healthy controls (P>0.05), but their functioning was still significantly reduced (P<0.05). In addition, the number of CD3(+)CD56(+) T lymphocytes increased significantly in AML patients with increased peripheral blood white blood cell (WBC) counts, and in ALL patients without increased WBCs. These results suggest that cellular immunity may respond to AML and ALL, but that lymphocyte cytotoxicity remains impaired. Dysfunction of CD3(+)CD56(+) T lymphocytes in AML and ALL patients may contribute to the failure of the host immune response against leukemic blasts.

(S)-6-{[(S)-2,2-Dimethyl-1,3-dioxolan-4-yl]meth-yl}-5,5-difluoro-5,6-dihydro-2H-pyran-2-one.

The title compound, C(11)H(14)F(2)O(4), is a γ,γ-gem-difluorinated α,ß-unsaturated δ-lactone. The dioxolane five-membered ring and the lactone ring adopt half-chair conformations. There are two inter-molecular C-H⋯O inter-actions involving the carbonyl group as an acceptor which stabilize the crystal structure.