The different variant allele frequencies of type I/type II mutations and the distinct molecular landscapes in CALR-mutant essential thrombocythaemia and primary myelofibrosis.

OBJECTIVE: Calreticulin (CALR) mutations have been identified as driver mutations in a quarter of patients with essential thrombocythaemia (ET) and primary myelofibrosis (PMF), which are subgroups of myeloproliferative neoplasms (MPNs). A 52-bp deletion (type I mutation) and a 5-bp insertion (type II mutation) are the most frequent variants. To better understand the impact of different CALR mutant variants, with or without nondriver mutations, on the clinical subtypes of MPN needs further investigation. METHODS: The clinical characteristics, laboratory parameters and genetic mutation statuses were analysed in a cohort of 77 MPN patients with CALR mutations (ET = 24, prePMF = 33, and overt PMF = 20). Targeted NGS using a 38-gene panel was performed to evaluate the variant allele frequency (VAF) of CALR type I/type II mutations and assess the molecular landscape of nondriver gene mutations. RESULTS: A lower VAF of type I vs. type II was observed in CALR-mutant ET, prePMF and overt PMF, and a higher frequency of type I vs. type II was found in CALR-mutant overt PMF. Additional somatic mutations were indicated to be useful in understanding the pathogenesis of MPN. In this study, the mutation landscape was more complex in overt PMF than in ET or in prePMF. Mutations in epigenetic regulators (ASXL1, EZH2 and TET2) were more common in overt PMF. CONCLUSIONS: The two different subtypes of CALR mutations may have different impacts on MPN. A lower VAF of CALR type I indicates a greater contribution to disease progression in MPN, and increased nondriver mutations may be important in myelofibrosis progression.

HNRNPH1 Is a Novel Regulator Of Cellular Proliferation and Disease Progression in Chronic Myeloid Leukemia.

RNA binding proteins act as essential modulators in cancers by regulating biological cellular processes. Heterogeneous nuclear ribonucleoprotein H1 (HNRNPH1), as a key member of the heterogeneous nuclear ribonucleoproteins family, is frequently upregulated in multiple cancer cells and involved in tumorigenesis. However, the function of HNRNPH1 in chronic myeloid leukemia (CML) remains unclear. In the present study, we revealed that HNRNPH1 expression level was upregulated in CML patients and cell lines. Moreover, the higher level of HNRNPH1 was correlated with disease progression of CML. In vivo and in vitro experiments showed that knockdown of HNRNPH1 inhibited cell proliferation and promoted cell apoptosis in CML cells. Importantly, knockdown of HNRNPH1 in CML cells enhanced sensitivity to imatinib. Mechanically, HNRNPH1 could bind to the mRNA of PTPN6 and negatively regulated its expression. PTPN6 mediated the regulation between HNRNPH1 and PI3K/AKT activation. Furthermore, the HNRNPH1-PTPN6-PI3K/AKT axis played a critical role in CML tumorigenesis and development. The present study first investigated the deregulated HNRNPH1-PTPN6-PI3K/AKT axis moderated cell growth and apoptosis in CML cells, whereby targeting this pathway may be a therapeutic CML treatment.

The Reparative Effects of Human Adipose-Derived Mesenchymal Stem Cells in the Chemotherapy-Damaged Thymus.

Hematological patients who accept chemotherapy always develop secondary tumor or even die of severe infections. As an important central lymphoid organ, the thymus is frequently damaged during chemotherapy. Previous studies showed that the mesenchymal stem cells (MSCs) can promote the proliferation and repair of epithelial cells in thymus. The purpose of our study is to investigate the reparative effects of human adipose-derived mesenchymal stem cells (hADMSCs) in chemotherapy-treated damaged thymus. Eighty mice were randomly divided into four groups: normal group, model control group, hADMSCs untreated group, and hADMSCs treated group. The mice were injected intraperitoneally with dexamethasone sodium phosphate (Dex 20 mg/kg), except the normal group. Then, the chemotherapy models were obtained after 1 week; the treated group was infused intraperitoneally with hADMSCs, whereas the model control group was injected with equal volumes of normal saline. The hADMSC's infusion day was regarded as day 0. The mice were sacrificed at different time points (days 3, 7, 10, and 14). The pathological structure and the function of the thymus, the recovery of T-lymphocyte subpopulation, and the proportion of regulatory T (Treg) cells in spleen and peripheral blood were detected. Additionally, we transfected hADMSCs by lentivirus with green fluorescent protein (GFP) to confirm whether they home to thymus and detected the expressions of cytokines that are associated with the development of thymus in hADMSCs and thymus. The results of the study showed that the hADMSCs treated group had a more rapid recovery in terms of thymic pathological structure and function. The hADMSCs could home to the damaged thymus and secrete cytokines that played important roles in repairing damaged thymus. The results indicated that hADMSCs could repair the damaged thymus caused by chemotherapy and improve the immune microenvironment, which may be a potential treatment for hematological patients.

The Long Noncoding RNA MEG3 and its Target miR-147 Regulate JAK/STAT Pathway in Advanced Chronic Myeloid Leukemia.

BACKGROUND: Long non-coding (lnc) RNAs plays an important role in chronic myeloid leukemia (CML). In this study, we aimed to uncover the mechanism of the lncRNA maternally expressed 3 (MEG3) and its target microRNA-147 (miR-147) in CML. METHODS: Sixty CML patients and 10 healthy donors were included in the study. The methylation of MEG3 and miR-147 promoter was determined by methylation-specific PCR. The relationship of MEG3 and miR-147 was explored by luciferase assay. The interactions of proteins were studied by RNA pull-down assay, RNA immunoprecipitation and co-immunoprecipitation. FINDINGS: Patients in accelerated phase CML (CML-AP) and blast phase CML (CML-BP) showed lower expressions of MEG3 and miR-147 and higher expressions of DNMT1, DNMT3B, MBD2, MECP2 and HDAC1 compared to the controls. These patients also showed a higher degree of methylation of MEG3 and miR-147 while there was a reduction after chidamide treatment. Furthermore, the overexpression of MEG3 and miR-147 inhibited cell proliferation both in vivo and in vitro, promoted apoptosis and decreased the expressions of DNMT1, DNMT3A, DNMT3B, MBD2, HDAC1 and MECP2. We also found MEG3 interacted with DNMT1, JAK2, STAT3, HDAC1, and TYK2, and JAK2 was bound to STAT3, STAT5 and MYC. More interestingly, JAK2 was bound to TYK2 by the bridge of MEG3. INTERPRETATION: LncRNA MEG3 and its target miR-147 may serve as a novel therapeutic target for CML blast crisis, and chidamide might have a potential clinical application in treating CML blast crisis.

Association between methylation of tumor suppressor gene SOCS1 and acute myeloid leukemia.

Suppressor of cytokine signaling­1 (SOCS1) is a widely recognized tumor suppressor gene. Silencing of SOCS1 expression as a result of promoter methylation is associated with occurrence and development of solid tumors such as liver, cervical and pancreatic cancer. However, the association between SOCS1 gene methylation and acute myeloid leukemia (AML) has not been well explored. In the present study, we examined whether gene expression and methylation status of SOCS1 was altered in AML, and whether this was related to disease occurrence and development. To assess this hypothesis, we analyzed SOCS1 in four groups of AML patients: i) Initial treatment group (IT); ii) relapsed/refractory group (RR); iii) remission group (RE); and iv) normal control group (NC). We also used leukemia cell lines U937 and THP­1 to study the underlying molecular mechanism of SOCS1 in AML, mainly the JAK2/STAT pathway. We used several techniques such as quantitative PCR (qPCR), methylation­specific PCR (MS­PCR), western blotting, flow cytometry and cell transfection techniques to analyze the expression and methylation status of SOCS1. We found that the SOCS1 gene methylation rate in the IT and RR groups was significantly higher than that in the RR and NC groups (48, 80 vs. 0 and 0%, respectively). Furthermore, mRNA and protein expression was significantly lower in the IT and RR groups when compared to the RE and NC groups. We also found that the JAK2/STAT signaling pathway was negatively affected by SOCS1. SOCS1 gene methylation caused gene silencing of SOCS1 which overcame the suppression of the downstream JAK2/STAT signaling pathway by SOCS1, and promoted the growth and proliferation of AML cells.

Research on the epigenetic regulation mechanism of the PTPN6 gene in advanced chronic myeloid leukaemia.

PTPN6, a tyrosine phosphatase protein, plays a negative role in cell signal transduction and is negatively correlated with tumour formation and growth. However, epigenetic regulation mechanism of the PTPN6 gene in advanced chronic myeloid leukaemia (CML) remains unclear. This study investigated bone marrow or blood samples from 44 CML patients and 10 healthy volunteers. KCL22 and K562 cells were cultured and treated with demethylation drugs and histone deacetylase inhibitors. Real time quantitative polymerase chain reaction (qPCR), methylation-specific PCR, bisulfite sequencing PCR, Western blotting, co-immunoprecipitation and chromatin immunoprecipitation (ChIP) was performed. PTPN6 was down-regulated in cell lines and patients with advanced phase CML, whereas DNMT1, DNMT3A, MECP2, MBD2 and HDAC1 were up-regulated. Treatment with 5-azacytidine, decitabine, sodium valproate and LBH589 increased PTPN6 expression, but decreased that of DNMT1, DNMT3A, MECP2, MBD2 and HDAC1. Immunoprecipitation and mass spectrometry showed that HDAC1 combined directly with PTPN6. ChIP-seq showed that HDAC1 did not combine with the promoter region of PTPN6, while MAPK, AKT, STAT5, JAK2 and MYC promoter regions all combined with HDAC1. PTPN6 is associated with progression of CML. Low expression level of PTPN6 was associated with DNA methylation and regulated by histone acetylation. HDAC1 participates in the regulation of PTPN6.

Expression of LMP and EBNA genes in Epstein-Barr virus-associated lymphomas in Hu-PBL/SCID mice.

Transplantation of peripheral blood lymphocytes (PBLs) from healthy humans with latent Epstein-Barr virus (EBV) infection into severe combined immunodeficiency (SCID) mice results in development of EBV-associated human B-cell lymphoma. However, the expression of EBV genes in relation to lymphoma development has not been reported. We investigated latent membrane protein (LMP) and EBV nuclear antigen (EBNA) gene expression in PBLs from EBV-positive blood donors and induced-lymphoma cells from SCID mice to elucidate the functions and effects of the EBV genome in the occurrence and development of lymphoma. PBLs were isolated from 9 healthy blood donors and transplanted into SCID mice. Gene expression levels of LMP-1, LMP-2A, and LMP-2B and EBNA-1, EBNA-2, EBNA-3A, EBNA-3B, EBNA-3C and EBNA-LP were monitored by real-time quantitative-polymerase chain reaction (qRT-PCR) in cells from nine EBV-induced lymphomas and in matched lymphocytes from healthy subjects. LMP-1, EBNA-1 and EBNA-2 protein levels were detected by western blotting. As a result, LMP-1, LMP-2A and LMP-2B mRNA levels were upregulated 256-, 38- and 331-fold, respectively, in the EBV-induced lymphoma cells compared with the controls, while EBNA-1 and EBNA-3A mRNA levels were upregulated 1157- and 1154-fold, respectively. EBNA-2, EBNA-3B, EBNA-3C and EBNA-LP mRNAs were detected in lymphoma cells, but not in lymphocytes from EBV-positive blood donors. LMP-1 and EBNA-2 proteins were not expressed in lymphocytes from EBV-positive blood donors, according to western blotting. Weak EBNA-1 expression was observed in lymphocytes from blood donors with latent EBV infection, while LMP-1, EBNA-1 and EBNA-2 protein levels were significantly upregulated in EBV-induced lymphoma cells, consistent with mRNA expression levels detected by qRT-PCR. In conclusion, LMP-1, LMP-2A, LMP-2B, EBNA-1 and EBNA-3A were upregulated in EBV-induced lymphoma cells, while EBNA-2, EBNA-3B, EBNA-3C and EBNA-LP were absent in lymphocytes from humans with latent EBV infection, but were positively expressed in EBV-induced lymphoma cells.

Impacts of K562 cells towards activities of Toll-like receptor pathway of human mesenchymal stem cell-bone marrow.

The study aim was to investigate the impacts of K562 cells towards the activities of Toll-like receptor pathway of human mesenchymal stem cell-bone marrow (HMSC-bm). The in vitro co-culture of HMSC-bm and K562 cells was set as the experiment group (HMSC-bm + K562), the HMSC-bm cultured alone was set as the control group (HMSC-bm), the expressions of six interested genes and their proteins, namely MyD88, P38, NF-κB, TAB1, TLR3 and TBK1, of the Toll -like receptor signaling pathway were detected and compared, as well as the secretions of such cytokines as IL-6, IL-8, TNF-α and IFN-α in the cell supernatant, which were regulated by the Toll-like receptor pathway. The expressions of MyD88, P38, TAB1 and TLR3 of the HMSC-bm + K562 group were higher than the HMSC-bm group, while that of TBK1 was lower, and the NF-κB expression showed no significant difference between the two groups (P > 0.05). Compared with the HMSC-bm group, the supernatant of HMSC-bm + K562 group exhibited the higher secretion levels of IL-6 and IL-8, while that of IFN-α was just contrary, and the differences were significant (P < 0.05). The secretion levels of TNF-α within the two groups were not significantly different (P > 0.05). The co-culture of K562 and HMSC-bm could induce the activity changes of Toll-like receptor pathway of HMSC-bm, which was beneficial towards the proliferation of K562 cells.

[Imatinib is effective in a 12-month-old boy with chronic myelogenous leukemia: case report and literature review].

OBJECTIVE: To summarize the clinical characteristics of an infant with chronic myelogenous leukemia (CML) and the effects of imatinib on the case. METHOD: The clinical features of an infant with CML, who was treated with imatinib in the Norman Bethune International Peace Hospital at June 2009, were retrospectively analyzed and the reports in literature were reviewed. The 1-year-old boy suffered from recurrent low-degree fever and pallor. He had a moderate anemia, distended abdomen and marked splenomegaly. Bone marrow aspiration revealed CML in chronic phase)CP). The t (9; 22))q34; q11) could be detected and BCR-ABL (p210) was positive. The boy was diagnosed as CML-CP and treated with imatinib 100 mg per day. There were 10 related papers and more than 100 child CML patients were reported as retrieved from CNKI)from its establishment to August 2014) and Wanfang Database)from its establishment to August 2014) when "Child", " Chronic" and "Leukemia" were used as keywords. And there were 30 related papers including 400 cases from PubMed Database (from its establishment to August 2014) and one detailed report of an infant with CML was retrieved when "childhood" and "chronic myeloid leukemia" "imatinib" were used as keywords. The clinical effects of imatinib in infant CML cases were analyzed and summarized based on the literature. RESULT: The boy obtained a complete hematologic response (CHR) at the 6th week of diagnosis, a complete cytogenetic response (CCyR) at the 3rd month and a complete molecular response)CMR) at the 12th month without side effect. This boy grows very well and after a 62-month follow-up, his disease was stable. According to the domestic literature, 5 children CML cases aged 6 -12 years were treated with imatinib without side effects and got complete hematologic response (CHR) after 2-month-therapy. The dose, metabolic characteristics and clinical observation of imatinib can be found in foreign literature and imatinib showed good response with good tolerance in children with CML. Imatinib is regarded as the first line drug for children CML. But it may affect the development of the children. CONCLUSION: The children with CML-CP had a good response to imatinib, but more experience in the treatment of children with CML with iniatinib is needed.

[SHP-1 gene in the disease progression of chronic myeloid leukemia].

OBJECTIVE: To investigate the profile of promoter methylation and expression of SHP-1 gene in the progression of chronic myeloid leukemia (CML). METHODS: The expression level of SHP-1 mRNA and protein in bone marrow or peripheral blood mononuclear cells from CML patients were detected by Western blot and SYBR Green-based qRT-PCR. The methylation status of SHP-1 were assessed by methylation-specific polymerase chain reaction (MSP) assay. K562 cells were infected with the lentiviral plasmids pEX-SHP-1-puro-Lv105 (K562-SHP-1) or pEX-EGFP-puro-Lv105 (K562-EGFP). The levels of proteins and phosphorylated proteins were detected by Western blot. qRT-PCR assay was used to test the level of BCR-ABL mRNA. RESULTS: The relative levels of SHP-1 mRNA were sharply decreased in advanced stages CML compared to chronic phase (CP)-CML (0.79±0.37 vs 1.18±0.64, P= 0.009). The level of SHP-1 protein was lower in advanced stages CML compared to CP-CML (0.57±0.02 vs 1.02±0.04, P=0.039). The frequency of SHP-1 gene promoter methylation at selected loci in CP-CML was 23.8% (10/42), and the methylated regions were detected in all advanced CML samples (P<0.01). SHP-1 was stably transfected into K562 cells and selected with puromycin. Overexpression of SHP-1 inhibited the proliferation and induced the apoptosis of K562 cells, meanwhile leaded to G0/G1 phase arrest. After transfection, the level of BCR-ABL mRNA was not affected in K562-SHP-1 cells (1.32±0.34) compared to K562-EGFP cells (1.18±0.20, P=0.644), but overexpression of SHP-1 caused a slight decrease in BCR-ABL protein in K562-SHP-1 cells compared to K562 -EGFP cells (0.78±0.15 vs 1.27±0.24, P=0.040). Overexpression of SHP-1 resulted in a remarkable decrease in MYC protein, phosphorylated forms of JAK2, STAT5, Akt and MAPK. However, the un-phosphorylated forms of these molecules were not significantly affected. CONCLUSION: Decreased expression of SHP-1 caused by aberrant promoter hypermethylation may play a key role in the progression of CML by dysregulation of BCR-ABL, Akt, MAPK, MYC, JAK2 and STAT5 signaling.

[Expression and clinical significance of MMP-2 and MMP-9 in B acute lymphoblastic leukemia].

This study was purposed to investigate the expression and clinical significance of MMP-2 and MMP-9 in patients with B-acute lymphoblastic leukemia (B-ALL). The expression of MMP-2 and MMP-9 in bone marrow mononuclear cells of B-ALL patients and normal controls was detected by RT-PCR. The gelatinolytic activity was detected by zymography. The results showed that the expression of MMP-2 in de novo and relapsed B-ALL patients was markedly higher than that in normal controls (P < 0.05). The expression of MMP-9 in de novo and relapsed B-ALL patients was markedly lower than that in normal controls (P < 0.05). The expression of MMP-2 and MMP-9 in patients with extramedullary infiltration was significantly higher than that in patients without extramedullary infiltration. The incidence of extramedullary infiltration in patients with MMP-2/MMP-9 (+) was markedly higher than that in patients with MMP-2/MMP-9 (-). The expression of MMP-9 was markedly higher in high-risk patients than that in standard-risk patients (P < 0.05), but the expression of MMP-2 had no significant difference between the high-risk and standard-risk patients (P > 0.05). It is concluded that MMP-2 and MMP-9 may be secreted by B lymphoblasts and may involve in the extramedullary infiltration. MMP-9 may correlate with poor prognosis.

Methylation and decreased expression of SHP-1 are related to disease progression in chronic myelogenous leukemia.

Despite the unprecedented success of tyrosine kinase inhibitors (TKIs) in treating chronic myelogenous leukemia (CML), some patients nevertheless progress to advanced stages of the disease. Thus far, the biological basis leading to CML progression remains poorly understood. SH2-containing tyrosine phosphatase 1 (SHP-1) is reported to bind to p210BCR­ABL1 and to function as a tumor suppressor. Furthermore, its substrates have been found to be essential for p210BCR-ABL1 leukemogenesis or CML progression. In the present study, we found that SHP-1 mRNA and protein levels were markedly decreased in patients in the accelerated and blastic phases of CML (AP-CML and BP-CML) compared to those in the chronic phase (CP-CML). In vitro, we demonstrated that overexpression of SHP-1 reduced p210BCR-ABL1 protein expression and activity in the K562 CML cell line and negatively regulated the AKT, MAPK, MYC and JAK2/STAT5 signaling pathways. Moreover, using a methylation-specific polymerase chain reaction (MSP) assay, abnormal methylation of the SHP-1 gene promoter region was found both in K562 cells and bone marrow (BM) or peripheral blood (PB) cells from AP-CML and BP-CML patients. In conclusion, our findings suggest that decreased expression levels of SHP-1 caused by aberrant promoter hypermethylation may play a key role in the progression of CML by dysregulating BCR-ABL1, AKT, MAPK, MYC and JAK2/STAT5 signaling.

[Cyclin E overexpression and centrosome amplification in squamous cell carcinoma of oral cavity].

OBJECTIVE: To study the correlation between cyclin E protein overexpression and centrosome amplification in oral squamous cell carcinoma (OSCC). METHODS: Formalin-fixed, paraffin-embedded tissues from 12 normal oral epithelium cases and 46 cases of OSCC were studied. Their centrosome status was analyzed by indirect immunofluorescence double staining with antibodies to centrosome protein gamma-tubulin and cytokeratin. The expression of cyclin E protein was studied by immunohistochemical methods. The correlation between cyclin E protein expression and centrosome amplification in OSCC was statistically analyzed by SPSS 12.0. RESULTS: Thirty-seven of the 46 OSCC cases (80.4%) studied showed evidence of centrosome amplification, as signified by enlargement and/or increase in number of centrosomes, while normal oral epithelium possessed centromeres of normal size and number. Positive staining for cyclin E protein was observed in 30 of the 46 OSCC cases (65.2%), while all the normal oral epithelium cases were cyclin E protein-negative. The percentage of centrosome amplification in OSCC with positive cyclin E protein staining (90.0%, 27/30) was higher than that in OSCC with negative cyclin E protein staining (62.5%, 10/16) (chi(2) = 5.014, P < 0.05). Centrosome amplification showed positive correlation with cyclin E protein overexpression (r = 0.330, P < 0.05). CONCLUSION: Up-regulation of cyclin E protein may represent one of the possible mechanisms for centrosome amplification in OSCC.