New ABL1 Kinase Domain Mutations in BCR::ABL1-Positive Acute Lymphoblastic Leukemia.

BACKGROUND: Since the development of the first-generation Tyrosine Kinase Inhibitor (TKI), it has played a crucial role in the treatment of BCR::ABL1-positive acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia (CML). However, ABL1 kinase domain (ABL1 KD) mutations confer resistance to several TKIs. These mutations have been extensively studied in chronic myeloid leukemia (CML) but less so in BCR::ABL1-positive acute lymphoblastic leukemia (ALL). METHODS: Our study aimed to analyze the the ABL1 KD mutations in 97 consecutive newly-diagnosed adults with BCR::ABL1-positive ALL before therapy, in cytogenetic complete remission and at relapse with next generation sequencing (NGS). The relationship between ABL1 KD mutations and TKI selection was also analyzed. RESULTS: Previously unreported ABL1 KD mutations R239G, F401V/L, R516L and K262T were the most prevalent in pre-therapy and cytogenetic remission samples, whereas T315I/P and P-loop mutations were most prevalent in relapse samples. R239G, F401V/L, R516L and K262T are related to the BCR::ABL1 structure, whereas T315I/P and P-loop mutations directly alter kinase activity. BaF3 cells transfected with ABL1 KD F401V, K262T, R239G, or R516L mutations were resistant to imatinib but strongly inhibited by olverembatinib with IC50 values of 0.73 to 1.52nM. Meanwhile, olverembatinib had advantages in increasing complete molecular response (CMR) and good prognosis. CONCLUSION: Overall, our findings indicate the prevalence and impact of new ABL1 KD mutations in BCR::ABL1-positive ALL patients, highlighting the necessity for effective therapies targetingthese mutations.

Mechanism Actions of Coniferyl Alcohol in Improving Cardiac Dysfunction in Renovascular Hypertension Studied by Experimental Verification and Network Pharmacology.

Renovascular hypertension (RH), a secondary hypertension, can significantly impact heart health, resulting in heart damage and dysfunction, thereby elevating the risk of cardiovascular diseases. Coniferol (CA), which has vascular relaxation properties, is expected to be able to treat hypertension-related diseases. However, its potential effects on cardiac function after RH remain unclear. In this study, in combination with network pharmacology, the antihypertensive and cardioprotective effects of CA in a two-kidney, one-clip (2K1C) mice model and its ability to mitigate angiotensin II (Ang II)-induced hypertrophy in H9C2 cells were investigated. The findings revealed that CA effectively reduced blood pressure, myocardial tissue damage, and inflammation after RH. The possible targets of CA for RH treatment were screened by network pharmacology. The interleukin-17 (IL-17) and tumor necrosis factor (TNF) signaling pathways were identified using a Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The inflammatory response was identified using a Gene Ontology (GO) enrichment analysis. Western blot analysis confirmed that CA reduced the expression of IL-17, matrix metallopeptidase 9 (MMP9), cyclooxygenase 2 (COX2), and TNF α in heart tissues and the H9C2 cells. In summary, CA inhibited cardiac inflammation and fibrohypertrophy following RH. This effect was closely linked to the expression of MMP9/COX2/TNF α/IL-17. This study sheds light on the therapeutic potential of CA for treating RH-induced myocardial hypertrophy and provides insights into its underlying mechanisms, positioning CA as a promising candidate for future drug development.

Venetoclax combined with decitabine induced tumor lysis syndrome in a young patient with acute myeloid leukemia: a case report and literature review.

Venetoclax, in combination with hypomethylation agents (HMAs), is a novel treatment for leukemia patients with low chemotherapy tolerance. However, it has been reported to be a risk of causing tumor lysis syndrome (TLS) in chronic lymphocytic leukemia (CLL) and elderly acute myeloid leukemia (AML) patients. Here we report a rare case of a young adult AML patient who induced TLS after receiving a combination therapy of venetoclax with decitabine (DEC). A 36-year-old male patient presented with an unexplained fever and was diagnosed with AML-M5a. The patient was first treated with a combination of antibiotics, including voriconazole 300 mg Q12h. After the infection was relieved, he was treated with 100 mg venetoclax in combination with 75 mg/m 2 DEC. However, 12 h after the first treatment, he developed diarrhea, fatigue and other symptoms, and the laboratory results were consistent with the laboratory TLS. The patient stopped chemotherapy immediately, and TLS gradually improved after receiving rehydration, diuresis, dialysis and other treatments. Finally, the patient achieved complete remission. Based on the experience of this case and related studies, we recommend the prevention of TLS should not be limited to elderly patients taking venetoclax, and it is equally important in young patients. And reduce the dosage of venetoclax when using azole antifungal drugs.

Elucidating the distinctive regulatory effects and mechanisms of active compounds in Salvia miltiorrhiza Bunge via network pharmacology: Unveiling their roles in the modulation of platelet activation and thrombus formation.

Salvia miltiorrhiza Bunge. (DS), as an important traditional Chinese medicine (TCM), has a long history of usage for promoting blood circulation and removing blood stasis. Modern studies have shown that the chemical components of DS have many biological activities such as cardiovascular protection, anti-arrhythmia, anti-atherosclerosis, improvement of microcirculation, protection of myocardium, inhibition and removal of platelet aggregation. Nevertheless, the action mechanism of DS as well its active compounds on platelet activation has not been fully uncovered. This study aimed to find out the potential targets and mechanisms of DS in the modulation of platelet activation and thrombosis, using network pharmacology and biological experimental. These compounds with anti-thrombotic activity in DS, cryptotanshinone (CPT), isoeugenol (ISO) and tanshinone IIA (TSA), together with the corresponding targets being Src, Akt and RhoA are screened by network pharmacology. We confirmed that ISO, CPT and TSA dose-dependently inhibited platelet activation in vitro, mainly by inhibiting agonist-induced clot retraction, aggregation and P-selectin and ATP release. The western blot findings indicated that ISO, CPT, and TSA led to reduced levels of p-Akt and p-ERK in activated platelets. Additionally, ISO and TSA were observed to decrease p-cSrc expression while increasing RhoA expression. ISO, CPT, and TSA demonstrated a potential to restrict the advancement of carotid arterial thrombosis in vivo. We confirm that ISO, CPT and TSA are the key anti-thrombotic active compounds in DS. These active compounds exhibit unique inhibitory effects on platelet activation and thrombus formation by modulating the Akt/ERK and cSrc/RhoA signaling pathways.

Nuclear Matrix-associated Protein SMAR1 Attenuated Acute Graft-versus-host Disease by Targeting JAK-STAT Signaling in CD4 + T Cells.

BACKGROUND: Acute graft-versus-host disease (aGVHD) mediated by alloreactive T cells remains a serious and life-threatening complication of allogeneic hematopoietic cell transplantation (allo-HCT). The contribution of the different CD4 + T helper cell subtypes to the pathogenesis and regulation of aGVHD is a central point in current research. The specialized effector subsets of T cells that differentiate from naive T cells into mature cells are closely related to scaffold/matrix-associated region-1-binding protein (SMAR1). However, the role of SMAR1 in aGVHD is unclear. METHODS: Peripheral blood was collected from the patients with or without aGVHD after allo-HCT. The differences in CD4 + T cells transduced with the SMAR1 lentivirus vector and empty vector were analyzed. A humanized aGVHD mouse model was constructed to evaluate the function of SMAR1 in aGVHD. RESULTS: The expression of SMAR1 was significantly reduced in the CD4 + T cells from aGVHD patients and related to the occurrence of aGVHD. SMAR1 overexpression in human CD4 + T cells regulated CD4 + T-cell subsets differentiation and inflammatory cytokines secretion and inhibited the Janus kinase/signal transducer and activator of transcription pathway. Moreover, SMAR1 changed chromatin accessibility landscapes and affected the binding motifs of key transcription factors regulating T cells. Additionally, upregulation of SMAR1 expression in CD4 + T cells improved the survival and pathology in a humanized aGVHD mouse model. CONCLUSIONS: Our results showed that upregulation of SMAR1 regulated the CD4 + T-cell subpopulation and cytokines secretion and improved survival in a humanized aGVHD mouse model by alleviating inflammation. This study provides a promising therapeutic target for aGVHD.

ALKHB5-demethylated lncRNA SNHG15 promotes myeloma tumorigenicity by increasing chromatin accessibility and recruiting H3K36me3 modifier SETD2.

Chromatin instability plays a crucial role in multiple myeloma (MM) relapse and progression, but its mechanism remains obscure. Here, we uncovered that m6A-demethylase ALKBH5 upregulated and stabilized long noncoding RNA (lncRNA) small nucleolar RNA host gene 15 (SNHG15), which was elevated in MM and positively correlated with unfavorable clinical prognosis factors. ALKBH5-SNHG15 axis participated in viability and migration/invasion of myeloma cell lines and MM-xenografted SCID/NOD mice. Mechanically, ALKBH5 promoted the expression of trimethylated histone H3 at lysine 36 (H3K36me3) methyltransferase SETD2 through lncRNA SNHG15-mediated protein stability. ALKBH5-SNHG15 axis increased chromatin accessibility and altered the H3K36me3 enrichment at the gene body, which is responsible for transcription elongation. Our study suggested a novel epigenetically interaction of N6-methyladenosine (m6A) methylation, lncRNA SNHG15, and histone SETD2/H3K36me3 modifications in myeloma progression, indicating that ALKBH5 and lncRNA SNHG15 could serve as potential novel therapeutic targets for MM treatment.NEW & NOTEWORTHY To our knowledge, this study first demonstrated the prognostic significance and biological function of long noncoding RNA (lncRNA) small nucleolar RNA host gene 15 (SNHG15) in multiple myeloma (MM), and indicated a novel revelation on the effect of N6-methyladenosine (m6A)-regulated lncRNA on MM tumorigenicity. Moreover, the novel chromatin-regulatory mechanism of lncRNA by interacting with epigenetic modifiers including m6A demethylase ALKBH5 and H3K36me3 methyltransferase SETD2 in myeloma progression elucidated intricate mechanism of tumor pathogenesis.

Comprehensive analysis of prognosis of cuproptosis-related oxidative stress genes in multiple myeloma.

Introduction: Multiple myeloma (MM) is a highly heterogeneous hematologic malignancy. The patients' survival outcomes vary widely. Establishing a more accurate prognostic model is necessary to improve prognostic precision and guide clinical therapy. Methods: We developed an eight-gene model to assess the prognostic outcome of MM patients. Univariate Cox analysis, Least absolute shrinkage and selection operator (LASSO) regression, and multivariate Cox regression analyses were used to identify the significant genes and construct the model. Other independent databases were used to validate the model. Results: The results showed that the overall survival of patients in the high-risk group was signifificantly shorter compared with that of those in the low-risk group. The eight-gene model demonstrated high accuracy and reliability in predicting the prognosis of MM patients. Discussion: Our study provides a novel prognostic model for MM patients based on cuproptosis and oxidative stress. The eight-gene model can provide valid predictions for prognosis and guide personalized clinical treatment. Further studies are needed to validate the clinical utility of the model and explore potential therapeutic targets.

A Visualized Mortality Prediction Score Model in Hematological Malignancies Patients with Carbapenem-Resistant Organisms Bloodstream Infection.

Background: Bloodstream infection (BSI) due to carbapenem-resistant organisms (CROs) has emerged as a worldwide problem associated with high mortality. This study aimed to evaluate the risk factors associated with mortality in HM patients with CROs BSI and to establish a scoring model for early mortality prediction. Methods: We conducted a retrospective cohort study at our hematological department from January 2018 to December 2021, including all HM patients with CROs BSI. The outcome measured was death within 30-day of BSI onset. Survivor and non-survivor subgroups were compared to identify predictors of mortality. Univariate and multivariate Cox regression analyses were used to identify prognostic risk factors and develop a nomogram. Results: In total, 150 HM patients were included in the study showing an overall 30-day mortality rate of 56%. Klebsiella pneumonia was the dominant episode. Cox regression analysis showed that pre-infection length of stay was >14 days (score 41), Pitt score >4 (score 100), mucositis (score 41), CAR (The ratio of C-reactive protein to albumin) >8.8 (score 57), early definitive therapy (score 44), and long-duration (score 78) were positive independent risk predictors associated with 30-day mortality, all of which were selected into the nomogram. Furthermore, all patients were divided into the high-risk group (≥160 points) or the low-risk group based on the prediction score model. The mortality of the high-risk group was 8 times more than the low-risk group. Kaplan-Meier analysis showed that empirical polymyxin B therapy was associated with a lower 30-day mortality rate, which was identified as a good prognostic factor in the high-risk group. In comparison, empirical carbapenems and tigecycline were poor prognostic factors in a low-risk group. Conclusion: Our score model can accurately predict 30-day mortality in HM patients with CROs BSI. Early administration of CROs-targeted therapy in the high-risk group is strongly recommended to decrease mortality.

Long noncoding RNA LINC01882 ameliorates aGVHD via skewing CD4+ T cell differentiation toward Treg cells.

Acute graft-versus-host disease (aGVHD) is a severe T cell-mediated immune response after allogeneic hematopoietic stem cell transplantation (allo-HSCT), the molecular mechanisms remain to be elucidated and novel treatments are necessary to be developed. In the present study, we found that the expression of long noncoding RNA (lncRNA) LINC01882 decreased significantly in the peripheral blood CD4+ T lymphocytes of patients with aGVHD than non-aGVHD patients. In addition, lncRNA LINC01882 overexpression promoted Treg differentiation but exhibited no effects on Th17 percentages, while its knockdown resulted in opposite effects. Mechanistically, lncRNA LINC01882 could competitively bind with let-7b-5p to prevent the degradation of its target gene smad2, which acts as a promoter in Treg differentiation. Furthermore, the mice cotransplanted with LINC01882-overexpressed CD4+ T cells with PBMCs had a lower histological GVHD score and higher survival rate compared with control mice. In conclusion, our study discloses a novel LINC01882/let-7b-5p/smad2 pathway in the modulation of aGVHD and indicates that lncRNA LINC01882 could be a promising biomarker and therapeutic target for patients with aGVHD.

A Novel Risk Predictive Scoring Model for Predicting Subsequent Infection After Carbapenem-Resistant Gram-Negative Bacteria Colonization in Hematological Malignancy Patients.

Background: This study investigated the high-risk factors associated with the increased vulnerability for subsequent clinical CR-GNB infection in carbapenem-resistant Gram-negative bacteria (CR-GNB)-colonized hematological malignancy (HM) patients and built a statistical model to predict subsequent infection. Method: All adult HM patients with positive rectoanal swabs culture for CR-GNB between January 2018 and June 2020 were prospectively followed to assess for any subsequent CR-GNB infections and to investigate the risk factors and clinical features of subsequent infection. Results: A total of 392 HM patients were enrolled. Of them, 46.7% developed a subsequent clinical CR-GNB infection, with 42 (10.7%) cases of confirmed infection and 141 (36%) cases of clinically diagnosed infection. Klebsiella pneumoniae was the dominant species. The overall mortality rate of patients colonized and infected with CR-GNB was 8.6% and 43.7%. A multivariate analysis showed that remission induction chemotherapy and the duration of agranulocytosis, mucositis, and hypoalbuminemia were significant predictors of subsequent infection after CR-GNB colonization. According to our novel risk-predictive scoring model, the high-risk group were >3 times more likely to develop a subsequent infection in comparison with the low-risk group. Conclusion: Our risk-predictive scoring model can early and accurately predict a subsequent CR-GNB infection in HM patients with CR-GNB colonization. The early administration of CR-GNB-targeted empirical therapy in the high-risk group is strongly recommended to decrease their mortality.

ALKBH5 Promotes Multiple Myeloma Tumorigenicity through inducing m6A-demethylation of SAV1 mRNA and Myeloma Stem Cell Phenotype.

N6-methyladenosine (m6A) is the most prevalent modification to RNA in higher eukaryotes. ALKBH5 is an RNA demethylase that impacts RNA export and metabolism, and its aberrant expression is associated with the generation of tumours. In this study, we found that ALKBH5 was highly expressed in both primary CD138+ plasma cells isolated from multiple myeloma (MM) patients and MM cell lines. Downregulation of ALKBH5 inhibited myeloma cell proliferation, neovascularization, invasion and migration ability, and promoted the apoptosis in vivo and in vitro. MeRIP-seq identified the SAV1 gene as main target gene of ALKBH5. Inhibiting ALKBH5 in MM cells increased SAV1 m6A levels, decreased SAV1 mRNA stability and expression, suppressed the stem cell related HIPPO-pathway signalling and ultimately activates the downstream effector YAP, exerting an anti-myeloma effect. Additionally, MM stem cell phenotype was suppressed in ALKBH5-deficient cells and the expression of pluripotency factors NANOG, SOX2 and OCT4 were also decreased. Altogether, our results suggest that ALKBH5 acts as an oncogene in MM and might serve as an attractive potential biomarker and therapeutic target.

Acute Promyelocytic Leukemia Presenting With a Myeloid Sarcoma of the Spine: A Case Report and Literature Review.

Myeloid sarcoma is a rare extramedullary tumor of immature myeloid cells. Certain known acute myeloid leukemia cytogenetic abnormalities, in particular t(8,21), has been associated with a higher incidence. Myeloid sarcoma, which rarely happens in acute promyelocytic leukemias, is more common in recurrent patients after the advent of all-trans retinoic acid (ATRA) and are rare in untreated acute promyelocytic leukemia. We described a case of, to our knowledge, de novo myeloid sarcoma of the spine confirmed as acute promyelocytic leukemia. Myeloid sarcoma is diagnosed by spinal tumor biopsy, and microscopic examination of a bone marrow smear and cytogenetic analysis led to a confirmed diagnosis of acute promyelocytic leukemia.

Prognostic Significance of Comprehensive Gene Mutations and Clinical Characteristics in Adult T-Cell Acute Lymphoblastic Leukemia Based on Next-Generation Sequencing.

Background: Adult T-cell acute lymphoblastic leukemia (T-ALL) is a heterogeneous malignant tumor with poor prognosis. However, accurate prognostic stratification factors are still unclear. Methods: Data from 90 adult T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) patients were collected. The association of gene mutations detected by next-generation sequencing and clinical characteristics with the outcomes of T-ALL/LBL patients were retrospectively analyzed to build three novel risk stratification models through Cox proportional hazards model. Results: Forty-seven mutated genes were identified. Here, 73.3% of patients had at least one mutation, and 36.7% had ≥3 mutations. The genes with higher mutation frequency were NOTCH1, FBXW7, and DNMT3A. The most frequently altered signaling pathways were NOTCH pathway, transcriptional regulation pathway, and DNA methylation pathway. Age (45 years old), platelet (PLT) (50 G/L), actate dehydrogenase (LDH) (600 U/L), response in D19-BMR detection, TP53 and cell cycle signaling pathway alterations, and hematopoietic stem cell transplantation (HSCT) were integrated into a risk stratification model of event-free survival (EFS). Age (45 years old), white blood cell (WBC) count (30 G/L), response in D19-BMR detection, TP53 and cell cycle signaling pathway alterations, and HSCT were integrated into a risk stratification model of overall survival (OS). According to our risk stratification models, the 1-year EFS and OS rates in the low-risk group were significantly higher than those in the high-risk group. Conclusions: Our risk stratification models exhibited good prognostic roles in adult T-ALL/LBL patients and might guide individualized treatment and ultimately improve their outcomes.

Emerging roles of long non-coding RNAs in allotransplant rejection.

Allotransplantation has extensively been employed for managing end-stage organ failure and malignant tumors. Acute and chronic post-transplant rejections are major causes of late morbidity and mortality after allotransplantation. However, there are no objective diagnostic criteria and specific therapy for post-transplant rejections. Owing to key advances in high-throughput RNA sequencing techniques, a wealth of studies have disclosed that long noncoding RNA (lncRNA) expression increased or decreased evidently in biopsies, blood, plasma, urine and specific cells of rejecting patients, and the dysregulated lncRNAs affected the cellular functions and differentiation of the immune system. Hence, we present an overview of the functions of lncRNAs expressed in various immune cells related to allotransplant rejection. Moreover, our review explores the regulatory interplay of relevant lncRNAs and recipients with or without allograft rejection after solid organ transplantations or hematopoietic stem cell transplantation, then discuss whether these relevant lncRNAs can be molecular biomarkers for diagnosis and new therapeutic targets in the management of post-transplanted patients.

Carbonic Anhydrase III Attenuates Hypoxia-Induced Apoptosis and Activates PI3K/Akt/mTOR Pathway in H9c2 Cardiomyocyte Cell Line.

Myocardial ischemia can cause insufficient oxygen and functional damage to myocardial cells. Carbonic anhydrase III (CAIII) has been found to be closely related to the abnormality of cardiomyocytes. To investigate the role of CAIII in the apoptosis of myocytes under hypoxic conditions and facilitate the strategy for treating hypoxia-induced damage, in vitro experiments in H9c2 were employed. The protein expression of CAIII in H9c2 cells after hypoxia or normoxia treatment was determined by western blotting and immunohistochemistry. MTT assay was employed for cells viability measurement and LDH release was monitored. The apoptotic cells were observed using immunofluorescence assay, flow cytometric analysis, and TUNEL assay. CAIII-overexpression or -knockdown cells were constructed to determine the role of CAIII in regulating apoptosis-related proteins caspase-3, Bax, Bcl-2, and anti-apoptosis pathway PI3K/Akt/mTOR. The mRNA levels of CAIII and genes related to CAIII synthesis including REN, IGHM, APOBEC 3F, and SKOR2 were significantly upregulated in hypoxia fetal sheep. The expression of CAIII protein and content of apoptotic H9c2 cells were increased at 1, 3, 6, and 12 h after hypoxia treatment. Overexpression of CAIII significantly upregulated Bcl2 level and downregulated Bax and caspase-3 cleavage levels, while its knockdown led to the contrary results. Overexpressed CAIII promoted the HIF-1α level and activated the PI3K/Akt/mTOR pathway, thereby exerting an inhibitory effect on hypoxia-induced apoptosis. In conclusion, our findings revealed that CAIII could protect cell from hypoxia-apoptosis of H9c2 cells, in which, activated PI3K/Akt/mTOR signaling pathway may be involved.

The role of E255K/V-inclusive mutations in a Philadelphia-positive acute lymphoblastic leukemia with mutation evolution during sequential TKIs therapies: A case report.

RATIONALE: Until recently, the survival rate in patients with Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) was approximately 30%. Tyrosine kinase inhibitors (TKIs), which are a new class of drugs that target BCR-ABL fusion protein, have shown to be effective in treating Ph+ ALL in adults. However, the resistance mechanisms that promote the disease recurrence have altered the initial success of these revolutionary agents. PATIENT CONCERNS: A 71-year-old Chinese female patient who suffered from severe shoulder and back pain for 1 week. DIAGNOSIS: The patient was diagnosed with Ph+ ALL (B-cell) because of the following items. Complete blood count showed extremely abnormal white blood cell count (26.26×109/l), hemoglobin concentration (65 g/l) and platelet count (14×109/l). And because that Bone marrow aspirate showed 72.5% lymphoblasts and 59.30% lymphoblasts were confirmed by flow cytometry (FCM). At mean time, Real-time fluorescent quantitative PCR analysis confirmed that the P190 BCR/ABL fusion gene expression was 5.9%. Karyotype analysis indicated the following: 45, XX, -7, t (922) (q34; q11) [cp3]. INTERVENTIONS: The patient was treated with chemotherapy and different TKIs including imatinib, dasatinib, ponatinib, and bosutinib. OUTCOMES: The patient achieved complete remissions with different TKIs after diagnose but relapsed afterward and died of infection. LESSONS: Multidrug-resistant mutations within the BCR-ABL1 kinase domain are an emerging clinical problem for patients receiving sequential TKIs therapy. Acquisition of E255K/V-inclusive mutations is usually associated with ponatinib resistance, thus it is necessary to screen out new real pan-inhibitor compounds for all BCR/ABL mutations and figure out the potential efficacy of asciminib-based drug combinations in the future.

RNA methylation in hematological malignancies and its interactions with other epigenetic modifications.

Hematological malignancies are a class of malignant neoplasms attributed to abnormal differentiation of hematopoietic stem cells (HSCs). The systemic involvement, poor prognosis, chemotherapy resistance, and recurrence common in hematological malignancies urge researchers to look for novel treatment targets and mechanisms. In recent years, epigenetic abnormalities have been shown to play a vital role in tumorigenesis and progression in hematological malignancies. In addition to DNA methylation and histone modifications, which are most studied, RNA methylation has become increasingly significant. In this review, we elaborate recent advances in the understanding of RNA modification in the pathogenesis, diagnosis and molecular targeted therapies of hematological malignancies and discuss its intricate interactions with other epigenetic modifications, including DNA methylation, histone modifications and noncoding RNAs.

PIWIL1 Drives Chemoresistance in Multiple Myeloma by Modulating Mitophagy and the Myeloma Stem Cell Population.

As an important member of the Argonaute protein family, PIWI-like protein 1 (PIWIL1) plays a key role in tumor cell viability. However, the exact function of PIWIL1 in multiple myeloma (MM) and the underlying mechanism remain unclear. Here, we revealed that PIWIL1 was highly expressed in myeloma cell lines and newly diagnosed MM patients, and that its expression was notably higher in refractory/relapsed MM patients. PIWIL1 promoted the proliferation of MM cells and conferred resistance to chemotherapeutic agents both in vitro and in vivo. More importantly, PIWIL1 enhanced the formation of autophagosomes, especially mitophagosomes, by disrupting mitochondrial calcium signaling and modulating mitophagy-related canonical PINK1/Parkin pathway protein components. Mitophagy/autophagy inhibitors overcome PIWIL1-induced chemoresistance. In addition, PIWIL1 overexpression increased the proportion of side population (SP) cells and upregulated the expression of the stem cell-associated genes Nanog, OCT4, and SOX2, while its inhibition resulted in opposite effects. Taken together, our findings demonstrated that PIWIL1 induced drug resistance by activating mitophagy and regulating the MM stem cell population. PIWIL1 depletion significantly overcame drug resistance and could be used as a novel therapeutic target for reversing resistance in MM patients.

Role of endothelial-microparticles and the tissue factor pathway in ginsenoside Rb1-mediated prevention of umbilical vein endothelial cell injury.

Hepatic veno-occlusive disease (VOD) is a life-threatening complication of hematopoietic stem cell transplantation, which urgently requires effective prevention and treatment. Endothelial damage is recognized as the first event in patients with hepatic VOD. However, the mechanism by which endothelial injury induces thrombosis in hepatic VOD is still not clear. In the present study, monocrotaline (MCT) was used to induce endothelial cell injury in EA.hy926 cells to imitate in vitro hepatic VOD. MCT significantly increased apoptosis in EA.hy926 endothelial cells and the secretion of endothelial microparticles (EMPs) which can be used to reflect the level of endothelial injury. Additionally, MCT significantly enhanced the expression of soluble tissue factor (TF) and EMP-bound TF protein, suggesting that EMPs may participate in the development of hepatic VOD by regulating coagulation. Ginsenoside Rb1, a major constituent and effective ingredient of Panax ginseng, was found to significantly decrease MCT-induced endothelial injury and release of EMPs. Moreover, Ginsenoside Rb1 decreased soluble TF released by EA.hy926 cells and EMP-bound TF protein induced by MCT. These data suggest that ginsenoside Rb1 may serve as a potent prophylactic and/or as a treatment of hepatic VOD by protecting endothelial cells and preventing microthrombosis induced by endothelial injury.

Monitoring Antiplatelet Aggregation In Vivo and In Vitro by Microtiter Plate Method.

BACKGROUND: The current light transmission aggregation method is a recognized conventional method for platelet function evaluation, but it is time-consuming and poor in parallelism and cannot simultaneously monitor multiple inducers at multiple levels. The microtiter plate method has been established because of the high-throughput characteristic, but it needs more practical applications. OBJECTIVES: To evaluate the microtiter plate method by using aspirin and clopidogrel in vivo and in vitro. METHODS: In vitro, the platelet aggregations inhibited by aspirin (0.3, 1, 3, 10, 30, 90 µM) and clopidogrel (1, 3, 10, 30, 100, 300 µM) were evaluated with the presence of arachidonic acid (AA) and adenosine diphosphate (ADP) agonists. Using the combination index (CI), the effect of the combination of aspirin and clopidogrel on platelet aggregation was evaluated. In vivo, New Zealand rabbits (n = 18) were randomly divided into 3 groups, aspirin group (5 mg/kg, intragastrical gavage [i.g.]), clopidogrel group (14 mg/kg at the first day, followed by 4 mg/kg, i.g.), and the combination of these two drugs, administered (i.g.) continuously for 7 days. Then, the blood was collected to measure platelet aggregation. RESULTS: Different concentrations of AA (12.5, 25, 50, 100 µM) and ADP (1.25, 2.5, 5, 10 µM) could promote platelet aggregation in concentration-dependent manner, and the most stable induction concentrations of AA and ADP were 50 and 5 µM. In vitro, with the above optimized detection system, aspirin and clopidogrel alone or in combination had concentration-dependent antiplatelet aggregation. The combination of aspirin and clopidogrel also showed synergistic inhibition effect within the concentration range studied. In vivo, aspirin and clopidogrel alone or in combination inhibited platelet aggregation induced by multiple concentrations of AA and ADP agonists, and the combined inhibition was more significant during the administration than aspirin or clopidogrel alone. CONCLUSIONS: The improved microtiter plate method combining the use of multiple levels of multiple agonists avoids the variation of the effective inducer concentrations due to individual different response of platelets to agonists. It may be a potential approach in the detection of platelet aggregation.