Mesenchymal stem cell-derived exosomes overexpressing SRC-3 protect mice from cerebral ischemia by inhibiting ferroptosis.

BACKGROUND: The treatment for cerebral ischemia remains limited, and new therapeutic strategies are urgently needed. Exosome has shown great promise for the treatment of cerebral ischemia. Steroid receptor coactivator-3 (SRC-3) was reported to be involved in neurological performances. In this study, we aimed to investigate the protective effects of mesenchymal stem cell (MSC)-derived exosomes overexpressing SRC-3 on cerebral ischemia in mice. METHODS: The mice were treated with an intracerebroventricular injection of GFP-overexpressed exosomes (GFP-exo) and SRC-3-overexpressed exosomes (SRC3-exo) in a middle cerebral artery occlusion (MCAO) model of cerebral ischemia. RESULTS: The results showed that SRC3-exo treatment significantly inhibited lipid peroxidation and ferroptosis of the neurons subjected to oxygen-glucose deprivation. It further suppressed the activation of microglia and astrocytes, and decreased the production of pro-inflammatory cytokines in the brains of MCAO mice. Furthermore, SRC3-exo treatment reduced the water content of brain tissue and infarct size, which alleviated the neurological damage and improved neurological performances in the MCAO mice. CONCLUSIONS: Our results suggest that MSC-derived exosomes expressing SRC3 can be a therapeutic strategy for cerebral ischemia by inhibiting ferroptosis.

Hemophagocytic lymphohistiocytosis secondary to virus infection and followed by lupus nephritis recurrence in a renal transplantation pediatric recipient: a case report.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening disorder characterized by systemic inflammation and organ failure as a result of dysregulated immune cell activation. HLH can be induced by a variety of factors including infection, tumours and autoimmune disease and can also occur in patients following solid organ transplantation. Occurrence of HLH and lupus nephritis (LN) successively within a short period of time after renal transplantation is uncommon. CASE PRESENTATION: We described an 11-year-old female post-transplant patient who presented with hemocytopenia, fever, elevated serum ferritin, splenomegaly, hyperlipidemia, and hypofibrinemia, and was clinically diagnosed with HLH. After comprehensive treatment with corticosteroids, intravenous immunoglobulin (IVIG), and reducing immunosuppressants, her condition improved, but then hematuria ensued. The transplant kidney biopsy showed LN. She was treated with hydroxychloroquine and methylprednisolone while intensive immunosuppressive agents were given. She has remained in remission for two years until now. CONCLUSIONS: The main inducing factors of HLH should be identified as early as possible, and accurate treatment plans should be taken. The long-course IVIG regimen may be one of the effective treatments for virus-induced HLH. After remission of HLH, we need to be alert to the recurrence of autoimmune diseases in patients with underlying diseases, and timely increase immunosuppressants.

LINC00461 Knockdown Enhances the Effect of Ixazomib in Multiple Myeloma Cells.

BACKGROUND: LINC00461 has been implicated to be involved in several types of cancer while its roles in multiple myeloma remain unclear. Our study aims to investigate the roles of LINC00461 in multiple myeloma and explore its effects on ixazomib therapy. METHODS: LINC00461 and small nuclear ribonucleoprotein polypeptide (SNRP) B2 knockdown stable cell lines were constructed. Cell viability assays including MTT, cell number counting, and colony formation were performed. RNA-pull down and immunoblotting assays were conducted to determine the intramolecular interactions. qRT-PCR and western blotting were conducted to determine the levels of target genes. Kaplan-Meier analysis was used to evaluate overall survival rates. RESULTS: Knockdown of LINC00461 or SNRPB2 enhanced ixazomib's cytotoxicity, as well as affected its regulatory effects on cell apoptosis and cell cycle distribution. Further results showed that LINC00461 knockdown reduced the expression levels of SNRPB2 by their interactions. Additionally, a positive correlation between LINC00461 and SNRPB2 was found in patients with multiple myeloma. Low expression of SNRPB2 was associated with a high survival rate in patients with multiple myeloma. CONCLUSION: Knockdown of LINC00461 enhanced the therapeutic effects of ixazomib against multiple myeloma in part by the regulation of SNRPB2.

Chidamide works synergistically with Dasatinib by inducing cell-cycle arrest and apoptosis in acute myeloid leukemia cells.

This research aimed to explore whether Chidamide works synergistically with Dasatinib in the therapy of Acute myeloid leukemia (AML) and the potential molecular mechanism. The inhibition rate of the Dasatinib and Chidamide combination was significantly better than that of the single-drug application for HL-60 cells. The combination of Dasatinib and Chidamide significantly enhanced the Abnormal histone deacetylase (HDAC) inhibitory activity of Chidamide in Kasumi-1 and HL-60 cells. In the combined group, the proportion of S phase was significantly decreased, and the proportions of G2/M phase were significantly increased. The inhibitory rate of CD34+ CD38- HL-60 cells or Kasumi-1 cells was elevated when the cells were disposed with both Chidamide and Dasatinib. Dasatinib and Chidamide had synergistic antitumor effect. The combination with Dasatinib enhanced the HDAC inhibitory activity of Chidamide, promoted cell apoptosis and cell-cycle arrest of AML cells, and enhanced the inhibition of leukemia stem cell proliferation.

Bone marrow-derived mesenchymal stem cells overexpressed with miR-182-5p protects against brain injury in a mouse model of cerebral ischemia.

BACKGROUND: Toll-like receptor 4 (TLR4) plays a critical role in ischemic brain injury by mediating the inflammatory response. The microRNA miR-185-5p suppresses inflammatory signaling by targeting TLR4. This study investigates whether overexpressing miR-182-5p in bone marrow-derived mesenchymal stem cells (BM-MSCs) could potentiate the neuroprotective effects of BM-MSCs in a mouse model of ischemic brain injury. METHODS: We isolated BM-MSCs from mice, transfected the cells with miR-182-5p mimic, determined their MSC lineage through flow cytometry analysis of surface markers, examined miR-182-5p and TLR4 expression levels, and injected them into mice undergone middle cerebral artery occlusion (MCAO). MSC transplanted mice were subjected to behavior assays to determine cognitive and motor functions and biochemical analysis to determine neuroinflammation and TLR4/NF-κB in the ischemic hemisphere. RESULTS: We found that BM-MSCs overexpressing miR-182-5p showed reduced TLR4 expression without affecting their MSC lineage. Mice transplanted with miR-182-5p overexpressing BM-MSCs after MCAO showed significantly improved cognitive and motor functions and reduced neuroinflammation, including suppressed microglial M1 polarization, reduced inflammatory cytokines, and inhibited TLR4/ NF-κB signaling. CONCLUSION: Our findings suggest that overexpressing miR-182-5p in BM-MSCs can enhance the neuroprotective effects of BM-MSCs against ischemic brain injury by suppressing TLR4-mediated inflammatory response.

Proteomic profiling of plasma exosomes from patients with B-cell acute lymphoblastic leukemia.

We aimed to comprehensively investigate the proteomic profile and underlying biological function of exosomal proteins associated with B-cell acute lymphoblastic leukemia. Exosomes were isolated from plasma samples collected from five patients with B-ALL and five healthy individuals, and their protein content was quantitatively analyzed by liquid chromatography with tandem mass spectrometry. A total of 342 differentially expressed proteins were identified in patients with B-ALL. The DEPs were mainly associated with protein metabolic processes and protein activity regulation and were significantly enriched in the Notch and autophagy pathways. Furthermore, we found that ADAM17 and ATG3 were upregulated in patients with B-ALL and enriched in the Notch and autophagy pathways, respectively. Further western blot analysis of exosomes collected from additional 18 patients with B-ALL and 10 healthy controls confirmed that both ADAM17 and ATG3 were overexpressed in exosomes derived from patients with B-ALL (p < 0.001). The areas under the curves of ADAM17 and ATG3 were 0.989 and 0.956, respectively, demonstrating their diagnostic potential. In conclusion, ADAM17 and ATG3 in plasma-derived exosomes may contribute to the progression of B-ALL by regulating the Notch and autophagy pathways. Hence, these proteins may represent valuable diagnostic biomarkers and therapeutic targets for B-ALL.

Mesenchymal Stem Cells Inhibit the Effects of Dexamethasone in Multiple Myeloma Cells.

Mesenchymal stem cells (MSCs) participate in the occurrence and development of multiple myeloma. This study is aimed at exploring whether the presence of MSCs affects dexamethasone's antitumor effects against multiple myeloma. Multiple myeloma cells (OPM-2 and RPMI8226 cells) were cocultured with MSCs with or without dexamethasone. Cell viability was determined by using cell number count, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and colony formation assay, respectively. Cell cycle distribution and cell apoptosis were evaluated by using flow cytometry. The mRNA and protein expressions of target genes were checked by using qRT-PCR and western blotting, respectively. It was found that cell viability of multiple myeloma cells increased in the presence of MSCs. Besides, the presence of MSCs suppressed cell apoptosis induced by dexamethasone via the regulation of BCL-2 (B cell lymphoma 2). The presence of MSCs also affected the effects of dexamethasone on cell cycle distribution. Similarly, LINC00461 overexpression suppressed the inhibition of cell proliferation, suppressed the induction of cell apoptosis, and affected the effects on cell cycle distribution induced by dexamethasone insult. However, LINC00461 knockdown enhanced the inhibitory effects on cell proliferation and the induction of cell apoptosis induced by dexamethasone. In summary, MSCs inhibited the effects of dexamethasone on multiple myeloma and its regulatory effects were associated with LINC00461.

SRC3 Promotes the Protective Effects of Bone Marrow Mesenchymal Stem Cell Transplantation on Cerebral Ischemia in a Mouse Model.

Mesenchymal stem cells (MSCs) derived from the bone marrow (BM) are reported to protect against ischemic brain injury. This study aimed to investigate whether the steroid receptor cofactor 3 (SRC3) was involved in MSC-induced neuroprotection. BM-MSCs were isolated from wild-type (WT) and SRC3 knockout (SRC3-/-) mice and transplanted into mice with middle cerebral artery occlusion (MCAO). The MSC identification and differentiation were determined by flow cytometry and Alizarin Red S staining after osteogenic and adipogenic stimulations. The effects of MSCs on brain injury were assessed by brain water content, modified neurological severity score (mNSS), Morris water maze test, and open field test. Finally, the effects of MSCs on MCAO-induced oxidative stress were assessed by measuring the levels of malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) and mRNA levels of SOD1, SOD2, and CAT. We found that SRC3 deficiency did not impact the MSC identification or osteogenic and adipogenic differentiation. MSC-SRC3-/- transplantation in mice that underwent the MCAO procedure exhibited diminished effects on suppression of brain edema, neurological deficits, cognitive disruption, locomotor impairment, and anxiety compared to comparable levels of MSC-WT. Finally, MSC-WT transplantation inhibited MCAO-induced oxidative stress, and the effects were significantly attenuated in MCAO mice transplanted with MSC-SRC3-/-. MSCs suppressed the MCAO-induced upregulation of MDA activity and the inhibition of SOD, GSH, SOD1, SOD2, and CAT levels, and SRC3-deficient MSCs showed significantly reduced effects. Our results indicate that SRC3 plays an important role in mediating the neuroprotective effects of MSCs in mice that experienced ischemic stroke.

17ß-Estradiol Attenuates Intracerebral Hemorrhage-Induced Blood-Brain Barrier Injury and Oxidative Stress Through SRC3-Mediated PI3K/Akt Signaling Pathway in a Mouse Model.

Estrogen is neuroprotective in brain injury models, and steroid receptor cofactor 3 (SRC3) mediates estrogen signaling. We aimed to investigate whether and how SRC3 is involved in the neuroprotective effects of 17ß-estradiol (E2) in a mouse model of intracerebral hemorrhage (ICH). Ovariectomized female mice were treated with E2 after autologous blood injection-induced ICH. Brain damage was assessed by neurological deficit score, brain water content, and oxidative stress levels. Blood-brain barrier (BBB) integrity was evaluated by Evan's blue extravasation and claudin-5, ZO-1, and occludin levels. SRC3 expression and PI3K/Akt signaling pathway were examined in ICH mice treated with E2. The effect of SRC3 on E2-mediated neuroprotection was determined by examining neurological outcomes in SRC3-deficient mice undergone ICH and E2 treatment. We found that E2 alleviated ICH-induced brain edema and neurological deficits, protected BBB integrity, and suppressed oxidative stress. E2 enhanced SRC3 expression and PI3K-/Akt signaling pathway. SRC3 deficiency abolished the protective effects of E2 on ICH-induced neurological deficits, brain edema, and BBB integrity. Our results suggest that E2 suppresses ICH-induced brain injury and SRC3 plays a critical role in E2-mediated neuroprotection.

SRC-3 Deficiency Exacerbates Neurological Deficits in a Mouse Model of Intracerebral Hemorrhage: Role of Oxidative Stress.

Intracerebral hemorrhage (ICH) causes long term neurological abnormality or death. Oxidative stress is closely involved in ICH mediated brain damage. Steroid receptor cofactor 3 (SRC-3), a p160 family member, is widely expressed in the brain and regulates transactivation of Nrf2, a key component of antioxidant response. Our study aims to test if SRC-3 is implicated in ICH mediated brain injury. We first examined levels of SRC-3 and oxidative stress in the brain of mice following ICH and analyzed their correlation. Then ICH was induced in wild type (WT) and SRC-3 knock out mice and how SRC-3 deletion affected ICH induced brain damage, oxidative stress and behavioral outcome was assessed. We found that SRC-3 mRNA and protein expression levels were reduced gradually after ICH induction in WT mice along with an increase in oxidative stress levels. Correlation analysis revealed that SRC-3 mRNA levels negatively correlated with oxidative stress. Deletion of SRC-3 further increased ICH induced brain edema, neurological deficit score and oxidative stress and exacerbated ICH induced behavioral abnormality including motor dysfunction and cognitive impairment. Our findings suggest that SRC-3 is involved in ICH induced brain injury, probably through modulation of oxidative stress.

Coagulation Factor XIII Subunit A Is a Biomarker for Curative Effects and Prognosis in Malignant Solid Tumors, Especially Non-small Cell Lung Cancer.

BACKGROUND: The expression of coagulant factor XIII subunit A (FXIII-A) is significantly increased in some types of cancer cells and tumor-associated macrophages (TAMs). However, few studies on plasma FXIII-A in cancer patients have been conducted and have shown contradictory results, so the relationship of plasma FXIII-A with the progression and prognosis of malignant tumors is still unknown. This study explored the association of plasma FXIII-A with a curative effect and the prognosis of patients with malignant solid tumors. METHODS: We monitored plasma FXIII-A before and during systemic therapy and assessed its relationship with the curative effect and prognosis of malignant solid tumors, especially non-small cell lung carcinoma (NSCLC), by propensity-adjusted, multivariable logistic regression analysis and survival curve, in a prospective study of 1147 patients with different types of malignant solid tumors. The influencing factors of plasma FXIII-A were also analyzed. RESULTS: We found that D-dimer (D2) = 1 mg/L was the inflection point for the association between FXIII-A and D2: FXIII-A was significantly negatively correlated with D2 (r = -0.39, p < 0.01) and FDP (r = -0.40, p < 0.01) in D2 > 1 mg/L but uncorrelated with D2 or FDP in D2 ≤ 1 mg/L, which provided a method to find a more realistic plasma FXIII-A level. Plasma FXIII-A was positively correlated with age, platelets, lymphocytes, monocytes and carcinoembryonic antigen (CEA). It was found for the first time that plasma FXIII-A was abnormally significantly increased (FXIII-A > 150%) in post-therapy patients, especially in NSCLC and lung metastasis patients, and the incidence of FXIII-A > 150% in lung adenocarcinoma was 16 times higher than that in lung squamous carcinoma. FXIII-A > 150% proved to be an independent risk factor for disease progression in NSCLC patients (OR=5.74, 95% CI: 1.20-27.60, p = 0.029), predicting poor efficacy. The marked decrease in plasma FXIII-A (FXIII-A < 40%) was related to coagulation disorders and poor prognosis with a short survival time (median survival time of 4 months). CONCLUSIONS: Plasma FXIII-A has the potential to be a real-time biomarker with bidirectional indicator effects to assess curative effects and prognosis in malignant solid tumors, especially NSCLC.

A small molecular compound CC1007 induces cross-lineage differentiation by inhibiting HDAC7 expression and HDAC7/MEF2C interaction in BCR-ABL1- pre-B-ALL.

Histone deacetylase 7 (HDAC7), a member of class IIa HDACs, has been described to be an important regulator for B cell development and has a potential role in B cell acute lymphoblastic leukemia (B-ALL). CC1007, a BML-210 analog, is designed to indirectly inhibit class IIa HDACs by binding to myocyte enhancer factor-2 (MEF2) and blocking the recruitment of class IIa HDACs to MEF2-targeted genes to enhance the expression of these targets. In this study, we investigated the anticancer effects of CC1007 in breakpoint cluster region-Abelson 1 fusion gene-negative (BCR-ABL1-) pre-B-ALL cell lines and primary patient-derived BCR-ABL1- pre-B-ALL cells. CC1007 had obvious antileukemic activity toward pre-B-ALL cells in vitro and in vivo; it also significantly prolonged median survival time of pre-B-ALL-bearing mice. Interestingly, low dose of CC1007 could inhibit proliferation of BCR-ABL1- pre-B-ALL cells in a time-dependent manner not accompanied by significant cell apoptosis, but along with cross-lineage differentiation toward monocytic lineage. From a mechanistic angle, we showed that HDAC7 was overexpressed in BCR-ABL1- pre-B-ALL cells compared to normal bone marrow samples, and CC1007 could reduce the binding of HDAC7 at the promoters of monocyte-macrophage-specific genes via inhibition of HDAC7 expression and HDAC7:MEF2C interaction. These data indicated that CC1007 may be a promising agent for the treatment of BCR-ABL1- pre-B-ALL.

[Relationship between TET2 Gene SNP rs3733609 C/T and JAK2V617F Allele Burden in Patients with Myeloproliferative Neoplasms].

OBJECTIVE: To investigate the relationship between the polymorphism of TET2 gene SNP rs3733609 and JAK2V617F allele burden in patients with myeloproliferative neoplasms (MPN). METHODS: The exon 9 of TET2 gene was amplified by RT-PCR, and the nucleotide sequence of SNP rs3733609 site was analyzed by gene sequencing. The MGB Taqman probe PCR method was used to detect the JAK2V617F allele burden. The correlation of TET2 gene SNP rs3733609 C/T with the JAK2V617F allele burden and clinical parameters was analyzed. RESULTS: TET2 gene rs3733609 C/T heterozygosity (normal T/T) could be detected in 19 cases of 85 cases of JAK2V617F positive MPN (22.4%) patients, while the TET2 gene rs3733609 C/T heterozygosity could be detected only in 9 of the 106 healthy volunteers, and the incidence was only 8.5% (9/106). Compared with the negative group (TET2 rs3733609 T/T), there was no significant difference in the median age, hemoglobin level and platelet count in the patients with TET2 gene SNP rs3733609 (CT/TC) positive, but the WBC count of peripheral blood and JAK2V617F allele burden significantly increased. In JAK2V617F high allele burden group, TET2 gene SNP rs3733609 was positive in 7 cases (36.8%, 7/19), the ratio was higher than that in the low allele burden group(18.2%, 12/66). CONCLUSION: TET2 SNP rs3733609 C/T may be a new susceptible allelee, which affects the clinical characteristics and clonal evolution of MPN patients.

Exosome-transmitted LINC00461 promotes multiple myeloma cell proliferation and suppresses apoptosis by modulating microRNA/BCL-2 expression.

BACKGROUND: Multiple myeloma (MM) is a hematologic cancer caused by the abnormal expansion of plasma cells, but the exact mechanism underlying MM development is not completely known. Recently, multiple long noncoding RNAs (lncRNAs) were implicated in the regulation of MM development. METHODS: Samples from patients with MM were collected and detected for LINC00461 expression using real-time polymerase chain reaction (PCR). LINC00461 was knocked down in MM cell lines by short hairpin RNAs (shRNAs) to measure its effect on MM cell proliferation and apoptosis. The function of mesenchymal stromal cell (MSC)-derived exosomes was analyzed using chamber assays. RESULTS: LINC00461 was highly expressed in MM. Knockdown of LINC00461 dramatically reduced MM cell proliferation and induced cell apoptosis. Further study showed that LINC00461 relieved the inhibitory effect of microRNA (miR)-15a/miR-16 on BCL-2. In addition, we observed that MSC-derived exosomes promoted MM cell proliferation through LINC00461. CONCLUSION: Our findings demonstrate that LINC00461, a sponge for miR-15a/16, is highly expressed in MSC-derived exosomes, and enhances MM cell proliferation, which may become an excellent candidate for therapeutic applications.

Pretreatment with 17ß-Estradiol Attenuates Cerebral Ischemia-Induced Blood-Brain Barrier Disruption in Aged Rats: Involvement of Antioxidant Signaling.

BACKGROUND/AIMS: Blood-brain barrier (BBB) disruption is often induced in brain injury and particularly associated with cerebral ischemia in stroke. Estradiol (17ß-estradiol 3-benzoate, E2), an endogenous steroid hormone, has been reported to play a protective role against cerebrovascular pathologies. Here we aimed to determine the potential effects of E2 on the integrity of BBB and brain damage following middle cerebral artery occlusion (MCAO). METHODS: Aged (24- month-old) ovariectomized female rats were administered E2 for 2 months through daily intraperitoneal injections prior to induction of MCAO. RESULTS: Compared to vehicle controls, E2 had a dose-dependent effect in reducing the severity of brain injuries while maintaining the integrity of the BBB in aged rats. The neuroprotective effects of E2 were associated with the rescued tight junction loss, decreased oxidative stress, and attenuated ERK activation in the ischemic brains. CONCLUSION: Our data suggest a beneficial role of E2 in aged stroke patients, associated with a protective effect of E2 against BBB disruption in aging-related brain ischemia.

Role of glycogen synthase kinase 3 in ischemia-induced blood-brain barrier disruption in aged female rats.

Estrogen receptors have protective effects against ischemic brain injury. However, the molecular mechanisms underlying this phenomenon have yet to be well studied. Given that inhibition of glycogen synthase kinase (GSK3) can reduce cerebral ischemia/reperfusion injury, we hypothesized that estrogen receptors-mediated protective effects against ischemia-induced blood-brain barrier (BBB) disruption involve inhibition of GSK3. Thus, we evaluated GSK3 expression in the brain of ovariectomized female rats, and examined the effects of intracerebroventricular pre-treatments of SB216763, GSK3 inhibitor, on BBB permeability following middle cerebral artery occlusion (MCAO). We also examined the role of specific estrogen receptor subtype in regulation of GSK3 expression and BBB permeability after MCAO. We found that ovariectomized female rats exhibited increased mRNA levels of estrogen receptor α (ERα) and estrogen receptor ß (ERß), and increased protein levels of GSK3ß but not GSK3α in brain cortical areas. Furthermore, intracerebroventricular pre-treatments of SB216763 dose-dependently attenuated brain infarction volume, brain water contents, neurological deficits, and BBB disruption, and increased tight junction protein ZO-1 and occludin expression at 24 h following MCAO. Finally, activation of ERß but not ERα dose-dependently decreased GSK3ß expression at 24 h following MCAO. This was associated with increased tight junction protein expression and improved neurological scores. Thus, our study suggested that activation of ERß may protect against brain ischemia-induced BBB disruption by inhibiting GSK3ß-mediated signaling.

Multiple myeloma-associated skin light chain amyloidosis: A case of misdiagnosis.

The present study reports the case of a 42-year-old male with multiple myeloma (MM)-associated skin light chain amyloidosis who presented with skin purpura as the initial symptom, which was misdiagnosis as Henoch-Schönlein purpura nephritis prior to admission to the Second Xiangya Hospital (Changsha, Hunan, China). The patient presented with purpura, papules petechiae and spontaneous ecchymosis, which was located scattered around the neck, chest and limbs, accompanied by a small amount of bleeding in the conjunctival and oral mucosa, and a swollen tongue. Upon laboratory examination, the serum immunological change showed increased serum immunoglobulin G and λ light chain levels, and a urine Bence Jones protein level of >1 g/24 h. This was accompanied with an abnormal result for immunofixation electrophoresis, and positive staining with Congo red showing apple-green birefringence in skin biopsy specimens. Thus, the patient was diagnosed with MM-associated skin amyloidosis with the initial symptom of skin purpura. Following treatment with chemotherapy consisting of prednisone and bortezomib, the skin lesions markedly improved. The present study indicates that the presentation of skin purpura in systemic amyloidosis associated with MM may be an important aid in the diagnosis and direct treatment of this disease in the clinic.

Hypermethylation of CpG sites at the promoter region is associated with deregulation of mitochondrial ATPsyn-ß and chemoresistance in acute myeloid leukemia.

BACKGROUND: Aberrant DNA methylation status of some genes has been shown to be involved in chemoresistance of acute myeloid leukemia (AML). We have recently found that down-regulation of the ß subunit of mitochondrial ATP synthase (ATPsyn-ß) leads to adriamycin resistance in acute and chronic myeloid leukemia cells, and hypermethylation of the ATPsyn-ß gene promoter is associated with chemoresistance in chronic myeloid leukemia. OBJECTIVE: To further investigate the relationship between methylation of ATPsyn-ß gene, mRNA expression as well as chemoresistance in AML. METHODS: Quantitative RT-PCR and methylation specific PCR were performed to assess mRNA expression and methylation status of ATPsyn-ß gene on primary bone marrow nuclear cells (BMMCs), and cell proliferation assay was used to determine the sensitivity of BMMCs to adriamycin. RESULTS: Hypermethylation status of ATPsyn-ß gene promoter existed in those relapsed/refractory AML patients, and this hypermethylation of the gene was associated with a suppressed mRNA expression levels. Four patients at diagnosis and relapse underwent gene methylation status shift from hypermethylation to hypomethylation, which was accompanied by reduced mRNA expression of the gene. 5-azacitidine(5-Aza)- a demethylating agent, could restore ATPsyn-ß mRNA expression and increase the adriamycin sensitivity of primary leukemic cells from seven relapsed/ refractory AML patients. CONCLUSIONS: Hypermethylation of ATPsyn-ß gene promoter is associated with a down-regulated mRNA expression and chemoresistance in AML patients.

A TET2 rs3733609 C/T genotype is associated with predisposition to the myeloproliferative neoplasms harboring JAK2(V617F) and confers a proliferative potential on erythroid lineages.

Common germline single-nucleotide polymorphisms (SNPs) at JAK2 locus have been associated with Myeloproliferative neoplasms (MPN). And, the germline sequence variant rs2736100 C in TERT is related to risk of MPN, suggesting a complex association between SNPs and the pathogenesis of MPN. Our previous study (unpublished data) showed that there was a high frequency distribution in rs3733609 C/T genotype at Ten-Eleven Translocation 2 (TET2) locus in one Chinese familial primary myelofibrosis. In the present study, we evaluate the role and clinical significance of rs3733609 C/T genotype in JAK2V617F-positive sporadic MPN (n = 181). TET2 rs3733609 C/T genotype had a higher incidence (13.81%; 25/181) in JAK2V617F-positive sporadic MPN patients than that in normal controls (n = 236) (6.35%; 15/236), which was predisposing to MPN (odds ratio(OR) = 2.361; P = 0.01). MPN patients with rs3733609 C/T genotype had increased leukocyte and platelets counts, elevated hemoglobin concentration in comparison with T/T genotype. Thrombotic events were more common in MPN patients with rs3733609 C/T than those with T/T genotype (P < 0.01). We confirmed that rs3733609 C/T genotype downregulated TET2 mRNA transcription, and the mechanism may be involved in a disruption of the interaction between CCAAT/enhancer binding protein alpha (C/EBPA) and TET2 rs3733609 C/T locus.TET2 rs3733609 C/T genotype stimulated the erythroid hematopoiesis in MPN patients. Altogether, we found a novel hereditary susceptible factor-TET2 rs3733609 C/T variant for the development of MPN, suggesting the variant may be partially responsible for the pathogenesis and accumulation of MPN.

Icaritin suppresses multiple myeloma, by inhibiting IL-6/JAK2/STAT3.

Icaritin is an active prenylflavonoid derived from Epimedium genus, a traditional Chinese medicine. Icaritin has a wide range of pharmacological and biological activities, including cardiovascular function improvement, hormone regulation and antitumor activity. Here, we investigated the effect of icaritin on multiple myeloma (MM) in vitro and in vivo. Icaritin inhibited cell growth of MM cell line and primary MM cells. In contrast, icaritin had low or no cytotoxic effect on normal hematopoiesis. We also demonstrated that in MM xenograft mouse models, icaritin suppressed tumor growth and decreased serum IL-6 and IgE levels, but did not show adverse reactions such as body weight loss. The anti-MM activity of icaritin was mainly mediated by inhibiting IL-6/JAK2/STAT3 signaling. We suggest that icaritin can be further tested in clinical trials in MM.