IDH2 regulates U2AF1 expression and hydroxymethylation in MDS patients.

The expression of some genes regulated by their DNA methylation is involved in pathogenesis and disease progression of myelodysplastic syndrome (MDS), which is characterised by abnormal differentiation and development of myeloid cells. Therefore, it is significant for us to work on investigating what factors regulate U2AF1 expression and hydroxymethylation in MDS patients. However, the members of TET protein family can change 5-methylcytosine (5mC) into 5-hydroxymethylcytosine5-methyl cytosine (5hmC). In general, 5mC and 5hmC levels maintain dynamic equilibrium, and their imbalance is associated with the onset and progression of some tumors. In this study, the expression and 5mC and 5hmC levels of U2AF1 gene decreased significantly after the treatment by decitabine in Mutz-1 cells. The decreased degree of 5hmC is far greater than that of 5mC. IDH2 expression decreased significantly followed by U2AF1 5hmC levels. However, the expression of other hydroxymethylation-related genes such as IDH1, TET1 and TET2 also decreased, but the difference did not achieve significance. Compared with IDH2 or U2AF1 wild-type MDS patients, U2AF1 expression and 5hmC level in patients with these two gene mutations were both significantly reduced.

YC-1 exerts inhibitory effects on MDA-MB-468 breast cancer cells by targeting EGFR in vitro and in vivo under normoxic condition.

3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1), the hypoxia-inducible factor-1 alpha (HIF-1α) inhibitor, suppresses tumor proliferation and metastasis by down-regulating HIF-1α expression under hypoxic conditions. Our previous studies demonstrated that YC-1 inhibited breast cancer cell proliferation under normoxic conditions. In the current study, we investigated the targets of YC-1 and mechanism of its action in MDA-MB-468 breast cancer cells. In the in vitro experiments, we found that YC-1 significantly inhibited MDA-MB-468 cell proliferation in normoxia and hypoxia. Under normoxic conditions, YC-1 induced apoptosis of MDA-MB-468 cells and blocked cell cycle in the G1 phase, and these effects were possibly related to caspase 8, p21, and p27 expression. RT-PCR and Western blotting results showed that YC-1 primarily inhibited HIF-1α at the mRNA and protein levels under hypoxic conditions, but suppressed the expression of epidermal growth factor receptor(EGFR) at the mRNA and protein levels under normoxic conditions. In vivo, YC-1 prolonged survival, increased survival rate, decreased tumor size and metastasis rate, and inhibited tissue EGFR and HIF-1α expression. However, YC-1 exerted no obvious effect on body weight. These results indicate that YC-1 inhibits the proliferation of MDA-MB-468 cells by acting on multiple targets with minimal side effects. Thus, YC-1 is a promising target drug for breast cancer.

Quercetin Inhibits KBM7R Cell Proliferation through Wnt/ß-Catenin Signaling.

Background: Tyrosine kinase inhibitors could treat chronic myelogenous leukemia (CML) effectively, but they have no effect on patients with T315I mutation. It is necessary to find drugs to overcome the resistance. Quercetin (Qu) is a kind of bioflavonoid with an antitumor effect. In this study, we observed the effect of Qu on proliferation and Wnt/ß-catenin pathway in KBM7R cells, an imatinib-resistant cell with T315I mutation. Methods: The IC50 of Qu was detected by trypan blue staining. The KBM7R cell apoptosis and cycle were detected through the method of flow cytometry (FCM). The expression of the related mRNA and protein was evaluated by means of an RT-PCR assay and western blot in KBM7 (sensitive to IM) and KBM7R cells. Results: These results showed that in the KBM7R cell, the proliferation inhibition effect was increased after 48 h administration with different Qu concentrations. The IC50 to Qu was 241.7 µmol/L. The different doses of Qu (50, 100, and 200 µmol/L) would raise apoptosis and depress the cell cycle at the G1 phase. Dealing with a median Qu concentration (100 µmol/L) for 48 h, the mRNA and the protein level of caspase-3, caspase-8, and caspase-9 along with p21 and p27 raised compared with the control. The median concentration of Qu could inhibit both the mRNA and protein levels of GSK-3ß, ß-catenin, and Lef-1 in the Wnt/ß-catenin signal pathway and also the downstream targets PPAR-δ and cyclin D1 in both KBM7 and KBM7R cells. Conclusions: Our findings suggest that Qu could inhibit proliferation, induce apoptosis, and arrest the cell cycle on IM-resistant KBM7R cells with T315I mutation. And this effect could be related with the inhibition of the Wnt/ß-catenin signal pathway and downstream targets.

Replicative senescence of human bone marrow and umbilical cord derived mesenchymal stem cells and their differentiation to adipocytes and osteoblasts.

Mesenchymal stem cells (MSC) which have self-renewal and multiple differentiation potential in vitro play important roles in regenerative medicine and tissue engineering. However, long-term culture in vitro leads to senescence which results in the growth arrest and reduction of differentiation. In this study, MSC derived from human bone-marrow (BM-MSC) and umbilical cord (UC-MSC) were cultured in vitro lasted to senescence. Senescence and apoptosis detection showed that the senescent cells increased significantly but the increase of apoptosis was not significant in the long term culture. Senescence related genes p16, p21 and p53 increased gradually in BM-MSC. However, p16 and p53 reduced and then increased but with the gradual increase of p21 in UC-MSC. Adipogenic differentiation decreased whereas the propensity for osteogenic differentiation increased in senescent MSC. Real time RT-PCR demonstrated that both C/EBPα and PPARγ decreased in senescent BM-MSC. However, in UC-MSC, PPARγ decreased but C/EBPα increased in late phase compared to early phase. The study demonstrated p21 was important in the senescence of BM-MSC and UC-MSC. C/EBPα and PPARγ could regulate the balance of adipogenic differentiation in BM-MSC but only PPARγ not C/EBPα was involved in the adipogenic differentiation in UC-MSC.

Arsenic trioxide promotes senescence and regulates the balance of adipogenic and osteogenic differentiation in human mesenchymal stem cells.

Arsenic trioxide (ATO) as an anti-tumor drug could induce differentiation and apoptosis in tumor cells. Mesenchymal stem cells (MSCs) play important roles in the hematogenesis of bone marrow. Many reports have shown that the disorder of MSC adipogenic and osteogenic differentiation occurs in some diseases. However, reports about the effects of ATO on MSCs are limited. In this study, we found that 1 µM ATO promoted MSC senescence mainly through p21, although it had no effect on apoptosis at this dose. Furthermore, ATO promoted adipogenic differentiation, but inhibited osteogenic differentiation in MSCs. Our study also showed that CCAAT/enhancer-binding protein alpha C/EBPα and peroxisome proliferator-activated receptor gamma PPARγ might be involved in the regulation of adipogenic and osteogenic differentiation induced by ATO. Our results indicated that ATO may exert an anti-tumor effect by influencing bone marrow micro-environment. Moreover, it may regulate the adipogenic and osteogenic differentiation of MSCs.

[Study on Immunophenotypes and Gene of Acute Lymphoblastic Leukemia].

OBJECTIVE: To retrospectively analyze the immunophenotyping, fusion gene and gene mutation of 30 acute lymphoblastic leukemia (ALL) cases and to investigate the relationship between the analysis results and the clinical therapeutic effect and prognosis. METHODS: Thirty All phtients were collected from the First Hospital of Harbin, Institute of Hematology and Oncology Department of Pediatrics from August 2015 to June 2016. According to the classification of FAB standard, 27 cases were B system ALL, 3 cases were T system ALL. All patients were diagnosed by bone marrow cell morphology, immunophenotype, cytogenetics and molecular biology detetions, the differentiation antigens on membrane surface and in cytoplasm of ALL cells, and 43 kinds of fusion gene qualitative screening（BCR-ABL， AML1-ETO, PML-RARα and so on） were qualitative screened and ALL gene mutations（IKZF1, TP53, PAX5, JAK1, JAK2, CRLF2, PHF6, NOTCH1, FBXW7, PTEN）were detected by next generation sequencing(NGS). RESULTS: (1) Among 30 ALL patients, the incidence of B-ALL(90.00%) was higher than that of T-ALL(10.00%). (2) 27 cases of B-ALL expressed CD19, CD22, CD10, CD34 and so on. CD19 and CD22 were the most diagnostic antigens of B-ALL. (3) 3 cases of T-ALL mainly expressed cCD3, CD7, CD10, cTDT and so on; cCD3 and CD7 were the most diagnostic antigens of T-ALL. (4) The quantitative screening of 30 cases of ALL 43 fusion genes found BCR-ABL,TEL-AML1 and E2A-PBX1, MLL-AF6, MLL-AF4, and SIL-TAL1 fusion gene was positive in 1 case each; NGS detection of gane mutations associated with ALL showed that: 3 cases of B-ALL found that TP53 mutation occured 3 casas of B-ALL, TET2 I1762V mutations in 1 cases, 3 patients (2 cases of T-ALL, 1 cases of B-ALL) showed NOTCH1 gene mutation. After a cycle of treatment, the efficacy of adult B-ALL treatment (28.57%) was significantly lower than that of child B-ALL (95.00%), and the survival rate of child B-ALL was significantly better than that of adult B-ALL until July 10, 2017, and the differences were significant. CONCLUSION: The immunophenotype technology of leukemia and molecular biology has an important guiding role in the diagnosis of leukemia, selection of treatment plan and evaluation of curative effect, and it is the complement of bone marrow cell morphology diagnosis.

TRIM37 promotes tumor cell proliferation and drug resistance in pediatric osteosarcoma.

Osteosarcoma (OS) is among the most frequently occurring bone tumors, particularly in children. Clinical treatment of OS is limited due to several factors including resistance to chemotherapy drugs and metastasis, and the underlying molecular mechanisms remain unclear. In the present study, tripartite motif containing 37 (TRIM37) expression levels were upregulated in tumor samples and associated with the development of drug resistance in OS. Furthermore, chemotherapy drug treatment (doxorubicin, cisplatin and methotrexate) induced TRIM37 expression in OS cells in vitro. TRIM37 mRNA and protein were upregulated in 41 pediatric osteosarcoma clinical specimens. To further elucidate the effect of TRIM37, gain and loss-of-function analysis was performed. Overexpression of TRIM37 induced cell proliferation and drug resistance ability of OS cells, whilst TRIM37 knockdown suppressed cell growth rate and restored chemosensitivity. TRIM37-regulated genes were subsequently analyzed by expression microarray and gene set enrichment analysis. Using the Wnt/ß-catenin inhibitor XAV-939, the present study demonstrated that TRIM37-induced chemoresistance is partially dependent on the activation of the Wnt/ß-catenin signaling pathway. Collectively, the results of the present study suggest that TRIM37 may have a key role in the development of OS and in the ability for the cells to acquire drug resistance, thus it may be a novel target for the treatment of OS.

[Application of Next Generation Sequencing for AML/MDS Diagnosis and Treatment].

OBJECTIVE: To detect the mutations of AML/MDS- related genes by using next generation sequencing (NGS), to analyze the mutation levels of each genes in the AML/MDS and the sensitivity of NGS, and to evaluate the feasibility of gene mutations for monitoring the MRD and predicating the progression of diseases. METHODS: The specimens were collected from primary AML (68 cases) and MDS (57 cases) patients from August 2015 to June 2016 in the Harbin Institute of Hematology and Oncology. The mutations of 22 related genes were detected by using AML/MDS-NGS chips. RESULTS: TET2 gene showed the highest mutation rate in AML (55.9%) and MDS (56.1%). The gene mutations were as follows: CEBPA (11.8%), DNMT3A (7.4%), C-KIT (7.4%) and FLT3-ITD (7.4%) in AML, and U2AF1 (10.5%) and SRSF2 (10.5%) in MDS. All the genes had specific mutation sites except TP53 and CEBPA. The mutations of FLT3, C-KIT and CEBPA became negative in the 5 AML patients in remission when compared with those at primary attack, but the mutation rate of TET2 gene was not obviously changed, whereas the mutation rate of the 5 MDS patients was not significantly changed. The new gene mutations appeared in 3 MDS patients with disease progression, but the mutation rate was not changed significantly in the disease progression. The gene mutation rate still has not been changed significantly even after remission. CONCLUSION: Both AML and MDS have their own specific mutated genes and sites. Some gene mutations, such as CEBPA, can be used as an effective indicator to monitoring MRD in AML patients, but those only used for the evaluation of the disease progression and prognosis in MDS patients.

Cytosine 5-hydroxymethylation regulates VHL gene expression in renal clear cell carcinoma.

Cytosine5-hyxymethylation (5hmC)which is a new epigenetic modification form plays important roles in the development and progression of tumors. In the present study, we observed that levels of 5hmC in the promoter region of Von Hippel-Lindau (VHL) were lower in 97 samples of renal clear cell carcinoma tissue than in matched adjacent benign tissues. Moreover, when the cancer tissue samples were divided based on pathological staging, VHL expression and the level of 5hmC in the VHL promoter were both lower in pathological grade III tumors than in grades I or II. Correspondingly, expression of TET1, which catalyzes the formation of 5hmC, was also lower in grade III renal clear cell carcinomas than in grade I or II disease. These findings suggest the 5hmC level on VHL is a key determinant of the gene's expression and may participate in the occurrence and development of renal clear cell carcinoma. Thus the 5hmC level may be a useful indicator for early diagnosis and appropriate treatment of renal clear cell carcinoma.

NNAT and DIRAS3 genes are paternally expressed in pigs.

Although expression and epigenetic differences of imprinted genes have been extensively characterised in man and the mouse, little is known on livestock species. In this study, the polymorphism-based approach was used to detect the imprinting status of NNAT and DIRAS3 genes in five heterozygous pigs (based on SNP) of Large White and Meishan F(1) hybrids. The results show that both genes were paternally expressed in all the tested tissues (heart, liver, spleen, lung, kidney, stomach, small intestine, skeletal muscle, fat, uterus, ovary and pituitary). In addition, the NNAT gene had two transcripts in all tested tissues, which is consistent with its counterpart in man and cattle.