Application value of metagenomic next-generation sequencing in hematological patients with high-risk febrile neutropenia.

Background: Metagenomic next-generation sequencing (mNGS) is a novel non-invasive and comprehensive technique for etiological diagnosis of infectious diseases. However, its practical significance has been seldom reported in the context of hematological patients with high-risk febrile neutropenia, a unique patient group characterized by neutropenia and compromised immune responses. Methods: This retrospective study evaluated the results of plasma cfDNA sequencing in 164 hematological patients with high-risk febrile neutropenia. We assessed the diagnostic efficacy and clinical impact of mNGS, comparing it with conventional microbiological tests. Results: mNGS identified 68 different pathogens in 111 patients, whereas conventional methods detected only 17 pathogen types in 36 patients. mNGS exhibited a significantly higher positive detection rate than conventional methods (67.7% vs. 22.0%, P < 0.001). This improvement was consistent across bacterial (30.5% vs. 9.1%), fungal (19.5% vs. 4.3%), and viral (37.2% vs. 9.1%) infections (P < 0.001 for all comparisons). The anti-infective treatment strategies were adjusted for 51.2% (84/164) of the patients based on the mNGS results. Conclusions: mNGS of plasma cfDNA offers substantial promise for the early detection of pathogens and the timely optimization of anti-infective therapies in hematological patients with high-risk febrile neutropenia.

Case report: Donor-derived CLL-1 chimeric antigen receptor T-cell therapy for relapsed/refractory acute myeloid leukemia bridging to allogeneic hematopoietic stem cell transplantation after remission.

Background: Explore the efficacy and safety of donor-derived CLL-1 chimeric antigen receptor T-cell therapy (CAR-T) for relapsed/refractory acute myeloid leukemia (R/R AML) bridging to allogeneic hematopoietic stem cell transplantation (allo-HSCT) after remission. Case presentation: An adult R/R AML patient received an infusion of donor-derived CLL-1 CAR-T cells, and the conditioning regimen bridging to allo-HSCT was started immediately after remission on day 11 after CAR-T therapy upon transplantation. Then, routine post-HSCT monitoring of blood counts, bone marrow (BM) morphology, flow cytometry, graft-versus-host disease (GVHD) manifestations, and chimerism status were performed. Result: After CAR-T therapy, cytokine release syndrome was grade 1. On day 11 after CAR-T therapy, the BM morphology reached complete remission (CR), and the conditioning regimen bridging to allo-HSCT started. Leukocyte engraftment, complete donor chimerism, and platelet engraftment were observed on days +18, +23, and +26 post-allo-HSCT, respectively. The BM morphology showed CR and flow cytometry turned negative on day +23. The patient is currently at 4 months post-allo-HSCT with BM morphology CR, negative flow cytometry, complete donor chimerism, and no extramedullary relapse/GVHD. Conclusion: Donor-derived CLL-1 CAR-T is an effective and safe therapy for R/R AML, and immediate bridging to allo-HSCT after remission may better improve the long-term prognosis of R/R AML.

Splenic marginal zone lymphoma with monoclonal IgG: A case report.

RATIONALE: Splenic marginal zone lymphoma (SMZL), an indolent small B-cell lymphoma, is uncommon, and part of the patients exist plasmocytic differentiation and secrete monoclonal paraproteins including IgM predominantly. SMZL with monoclonal IgG is rarer. PATIENT CONCERNS: We report a case of SMZL (49-year-old, male) with monoclonal IgG, MYD88L265P mutation and hepatitis B virus infection. DIAGNOSES: The patient was presented to our hospital with aggravating complaints of dizziness, fatigue, postprandial abdominal distension, and night sweats. The diagnosis was confirmed by clinical manifestations, immunophenotype, bone marrow pathology. INTERVENTIONS: The patient received rituximab-based chemotherapy and sequential ibrutinib in combination with entecavir. OUTCOMES: After 1 year of follow-up, his blood routine examination had returned to normal with normal level of albumin and significantly lower globulin than before, and the spleen was of normal size. LESSONS: We conclude that rituximab-based chemotherapy is the main treatment option for the patients with SMZL, and Bruton's tyrosine kinase inhibitor has also shown beneficial efficacy.

FAT1 inhibits AML autophagy and proliferation via downregulating ATG4B expression.

BACKGROUND: Emerging studies have shown that FAT atypical cadherin 1 (FAT1) and autophagy separately inhibits and promotes acute myeloid leukemia (AML) proliferation. However, it is unknown whether FAT1 were associated with autophagy in regulating AML proliferation. METHODS: AML cell lines, 6-week-old male nude mice and AML patient samples were used in this study. qPCR/Western blot and cell viability/3H-TdR incorporation assays were separately used to detect mRNA/protein levels and cell activity/proliferation. Luciferase reporter assay was used to examine gene promoter activity. Co-IP analysis was used to detect the binding of proteins. RESULTS: In this study, we for the first time demonstrated that FAT1 inhibited AML proliferation by decreasing AML autophagy level. Moreover, FAT1 weakened AML autophagy level via decreasing autophagy related 4B (ATG4B) expression. Mechanistically, we found that FAT1 reduced the phosphorylated and intranuclear SMAD family member 2/3 (smad2/3) protein levels, thus decreasing the activity of ATG4B gene promoter. Furthermore, we found that FAT1 competitively bound to TGF-ßR II which decreased the binding of TGF-ßR II to TGF-ßR I and the subsequent phosphorylation of TGF-ßR I, thus reducing the phosphorylation and intranuclear smad2/3. The experiments in nude mice showed that knockdown of FAT1 promoted AML autophagy and proliferation in vivo. CONCLUSIONS: Collectively, these results revealed that FAT1 downregulates ATG4B expression via inhibiting TGFß-smad2/3 signaling activity, thus decreasing the autophagy level and proliferation activity of AML cells. GENERAL SIGNIFICANCE: Our study suggested that the "FAT1-TGFß-smad2/3-ATG4B-autophagy" pathway may be a novel target for developing new targeted drugs to AML treatment.

Novel_circ_003686 regulates the osteogenic differentiation of MSCs in patients with myeloma bone disease through miR-142-5p/IGF1 axis.

Objectives: Circ_003686 is a novel_circRNA with abnormally low expression found in the samples of multiple myeloma bone disease (MBD) patients. The current research intended to investigate the effects of novel_circ_003686 in osteogenesis-induced differentiation of bone marrow mesenchymal stem cells (BMSCs) in MBD. Methods: BMSCs were extracted from MBD patients and normal participants, the pcDNA3.1 encoding the circ_003686 (ov-circ_003686), miR-142-5p-mimic/inhibitor and siRNA oligonucleotides targeting insulin like growth factor 1 (IGF1, si-IGF1) were applied to intervene circ_003686, miR-142-5p and IGF1 levels, respectively. Results: Results showed that ov-circ_003686 could mediate the osteogenesis-induced differentiation of MBD-BMSC, and luciferase assay and RIP experiments confirmed that circ_003686 could bind to miR-142-5p. MiR-142-5p-inhibitor helped osteogenesis-induced differentiation, while miR-142-5p-mimic inhibited osteogenesis-induced differentiation and reversed the promoting effect of ov-circ_003686, suggesting that circ_003686/miR-142-5p axis participated in osteogenesis-induced differentiation of MBD-BMSC. In addition, miR-142-5p binds to the target gene IGF1 and negatively adjust its expression. Si-IGF1 significantly inhibited the osteogenesis-induced differentiation and reversed the promotion effects of miR-142-5p-inhibitor and ov-circ_003686. Moreover, circ_003686/miR-142-5p/IGF1 axis meaningfully regulates protein expressions in the PI3K/AKT pathway. Conclusion: In conclusion, this research confirmed that circ_003686 regulated the osteogenesis-induced differentiation of MBD-BMSC by sponging miR-142-5p and mediating IGF1, and the PI3K/AKT pathway may also be involved.

Family Aggregation of Hematological Malignancies Discovered from an Acute Myeloid Leukemia Patient with STK11 and THBD Gene Mutation.

Acute myeloid leukemia (AML) is a large class of heterogeneous hematological malignancies with the highest incidence rate in acute leukemia. Its pathogenesis is still unclear, which may be related to genetics. According to the latest AML NCCN guidelines, genes involved in AML family genetic changes include RUNX1, ANKRD26, CEBPA. Finding new genes related to AML genetics is of great significance for predicting the prognosis of patients, developing targeted drugs, and selecting transplant donors. Here, we report a case of adult female AML patient whose three relatives suffered from hematological malignancies, including Waldenstrom macroglobulinemia, NK/T-cell lymphoma, and angioimmunoblastic T-cell lymphoma. The screen for genetic susceptibility genes related to blood and immune system diseases was carried out, and the result showed that the patient herself, her son, her daughter, and her two cousins all had STK11 p.F354L and/or THBD p.D486Y mutations. At present, there is no research or case report on the relationship between STK11/THBD and family aggregation of hematological malignancies. We report for the first time that an AML patient with STK11 and THBD mutations has a family aggregation of hematological malignancies, and consider that STK11 and THBD may be related to family genetic changes which ultimately cause the family aggregation of hematological malignancies.

Case report: Successful treatment of Chidamide in a refractory/recurrent SPTCL with ARID1A mutation on the basis of CHOP plus auto-HSCT.

RATIONALE: Subcutaneous panniculitis like T-cell lymphoma (SPTCL) is a rare primary cutaneous lymphoma that belongs to peripheral T cell lymphomas, of which the overall prognosis is poor. Chidamide, a deacetylase inhibitor, has been approved for the treatment of peripheral T cell lymphomas. However, due to the rare occurrence of SPTCL, it is currently unknown whether Chidamide is effective for all SPTCL patients and whether there are molecular markers that can predict its therapeutic effect on SPTCL. PATIENT CONCERNS AND DIAGNOSES: The patient was a sixteen-year-old male and underwent subcutaneous nodule biopsy which showed SPTCL. Next-generation sequencing revealed AT-rich interaction domain 1A (ARID1A) mutation, and positron emission tomography/computed tomography showed scattered subcutaneous fluorodeoxyglucose metabolic lesions throughout the body. INTERVENTIONS AND OUTCOMES: During the first 3 CHOP (cyclophosphamide, doxorubicin, vindesine, and prednisone) treatment, the patient relapsed again after remission, and the successive addition of methotrexate and cyclosporine did not make the patient relapsing again. Then, after adding Chidamide to the last 3 CHOP treatment, the patient was relieved again. The patient underwent autologous hematopoietic stem cell transplantation (auto-HSCT) after completing a total of 8 cycles of chemotherapy, and continued maintenance therapy with Chidamide after auto-HSCT. Currently, the patient has been in continuous remission for 35 months. LESSONS SUBSECTIONS: This case is the first report of a refractory/recurrent SPTCL with ARID1A mutation treated with Chidamide. The treatment of Chidamide on the basis of CHOP plus auto-HSCT therapy achieved good results, suggesting that ARID1A may act as a molecular marker to predict the therapeutic effect of Chidamide on SPTCL patients, which helps to improve the precision of SPTCL treatment and the overall prognosis of SPTCL patients.

Role of the bone marrow microenvironment in multiple myeloma treatment using CAR-T therapy.

INTRODUCTION: Multiple myeloma (MM) is a malignant tumor caused by abnormal proliferation of bone marrow (BM) plasma cells and is the second most common hematologic malignancy. A variety of CAR-T cells targeting multiple myeloma-specific markers have shown good efficacy in clinical trials. However, CAR-T therapy still limits the insufficient duration of efficacy and recurrence of the disease. AREAS COVERED: This article reviews the cell populations in the bone marrow of MM, and discusses the potential way to improve the efficiency of CAR-T cells in the treatment of MM by targeting the bone marrow microenvironment. EXPERT OPINION: The limits of CAR-T therapy in MM may related to the impairment of T cell activity in the bone marrow microenvironment. This article reviews the cell populations of the immune microenvironment and nonimmune microenvironment in the bone marrow of multiple myeloma, and discusses the potential way to improve the efficiency of CAR-T cells in the treatment of MM by targeting the bone marrow. This may provides a new idea for the CAR-T therapy of multiple myeloma.

Prophylactic use of interleukin 6 monoclonal antibody can reduce CRS response of CAR-T cell therapy.

Background: Chimeric antigen receptor T (CAR-T) cell immunotherapy is becoming one of the most promising treatments for hematological malignancies, however, complications such as cytokine release syndrome (CRS) seriously threaten the lives of patients. Interleukin 6(IL-6) monoclonal antibody is the common and useful treatment of CRS, however, it is not clear whether prophylactic use IL-6 monoclonal antibody before CAR-T therapy can reduce the incidence of CRS. Purpose: This study aims to systematically evaluate whether the prophylactic use of IL-6 monoclonal antibody can reduce the incidence of CRS. Data sources and methods: We searched the PubMed, Embase, web of Science, and Cochrane Library databases for studies that reported the prophylactic use of IL-6 monoclonal antibody in the treatment of CRS-related complications of CAR-T cell immunotherapy before December 2022. The literature is screened according to the established inclusion and exclusion criteria, relevant data are extracted, and the quality of the literature is evaluated using the scale Cochrane bias risk assessment tool, and the Review Manager 5.3 is used to draw for related charts. Since the two experimental data only provide the median, the maximum and minimum values of the data, the mean and standard (Standard Deviation, SD) are calculated by this document Delai, and finally use Review Manager for data processing, and STATA software for supplementation. Results: A total of 2 trials with a total of 37 participants were included in this study. Meta-analysis showed that compared with no use of IL-6 monoclonal antibody to prevent CRS, IL-6 monoclonal antibody was given to patients at 8 mg/kg one hour before CAR-T cell infusion, which reduced the incidence of CRS [RR: 0.41 95% confidence interval (0.20, 0.86) I[2] = 0.0% P = 0.338 z = -2.369 (p = 0.018)]. In subgroup analysis, compared with those who did not use IL-6 monoclonal antibody to prevent CRS, IL-6 monoclonal antibody was given to patients at 8 mg/kg one hour before CAR-T cell infusion, which reduced lactate dehydrogenase (LDH)[MD: -617.21, 95% confidence interval (-1104.41, -130.01) I[2] = 0% P = 0.88 Z = 2.48 (P = 0.01)], prophylactic use of IL-6 monoclonal antibody has a significant effect on reducing peak C-reactive protein (CRP) after CAR-T therapy [MD: -11.58, 95% confidence interval (-15.28, -7.88) I[2] = 0.0% P = 0.73 z = 6.14 (p < 0.00001)]. Conclusion: The prophylactic use of IL-6 monoclonal antibody can significantly reduce the incidence of CRS complications after CAR-T therapy, can also reduce LDH vaule and peak CRP vaule after CAR-T therapy. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023487662, identifier CRD42023487662.

Effect of miR-381-3p/FGF7 axis on the osteogenic differentiation of bone marrow mesenchymal stem cells through MEK/ERK signaling pathway.

Although microRNAs (miRNAs) exert an important role in the osteogenesis of mesenchymal stem cells (MSCs), the effect of miR-381-3p on the osteogenic differentiation in MBD­MSCs is still unclear. The BMMSCs from patients with MBD (MBD­MSC) or normal participants (Normal­MSC) were isolated and induced to differentiation with dexamethasone. BMMSCs were transfected with miR-381-3p mimic, miR-381-3p inhibitor, and FGF7 siRNA to regulate the expression of miR-381-3p or FGF7. The direct binding between miR-381-3p and FGF7 was predicted and confirmed by bioinformatics prediction and luciferase reporter assay. The effect of miR-381-3p on the osteogenic differentiation of BMMSCs was assessed by RT­qPCR, alizarin Red S staining and western blot assays. Isolated BMMSCs showed the regular morphology, and were positive for CD44, CD90 and CD105 but negative for CD34 and CD45 markers. The calcium deposition and the relative mRNA expression levels of ALP, OC and OPN after induction were markedly enhanced. MiR-381-3p was upregulated in BMMSCs. Also, inhibition of miR-381-3p notably promoted osteogenic differentiation, vice versa. Besides, miR-381-3p could directly target FGF7 and negatively modulate the expression of FGF7. Moreover, inhibition of FGF7 attenuated the increase of the calcium deposition, and the relative mRNA expression of ALP, OC and OPN caused by the downregulation of miR-381-3p. In addition, the miR-381-3p inhibitor-induced the enhancement of the relative protein expressions of FGFR2, p-MEK and p-ERK1/2 were significantly reduced by the co-transfection of si-FGF7. Furthermore, the application of LY3214996, the inhibitor of ERK also verified these outcomes. MiR-381-3p directly targeting FGF7 modulated the osteogenic differentiation via MEK/ERK signaling pathway in BMMSCs.

Case Report: Bortezomib Plus CDOP Followed by Sequential Autologous Hematopoietic Stem Cell Transplantation and Lenalidomide-Based Maintenance Therapy in Plasmablastic Lymphoma.

The standardized treatment plan for patients with plasmablastic lymphoma (PBL) remains controversial. Taking morphological characteristics and immunophenotypes into consideration may provide superior options for the treatment of PBL. In this case, we report that a myeloma-type regimen containing bortezomib plus cyclophosphamide, epirubicin, vindesine and prednisolone (CDOP) followed by sequential autologous hematopoietic stem cell transplantation (ASCT) and lenalidomide-based maintenance therapy to treat PBL may represent a promising regimen to improve the prognosis.

Whole genome, exon mutation and transcriptomic profiling of acute myeloid leukemia: A case report.

The present study aimed to observe previously unidentified gene mutation and expression profiles associated with acute myeloid leukemia (AML) at the individual level, based on the blood samples of a father-son pair. Genomic DNA and RNA samples from blood serum were collected. Whole-genome sequencing (WGS) and whole-exome sequencing (WES), as well as mRNA sequencing of the son, were performed. For the father's sample, a total of 3,897,164 single nucleotide polymorphisms (SNPs) and 780,834 insertion and deletions (indels) were identified. Regarding amino acid translation, there were 11,316 non-synonymous, 12 stop-loss, 12,033 synonymous, 92 stop-gain SNPs, 63 frameshift insertions, 73 frameshift deletions, 242 non-frameshift insertions, 248 non-frameshift deletions, four stop-gains and two stop-loss for indel variants. Among the AML-related genes that had been previously identified, 14 genes were found in the father's exon region. For WES of the son's DNA, 96,639 SNPs were identified, including 10,504 non-synonymous SNPs. Seven mutant genes were found in sons' exon region compared with 121 AML-related genes. Based on the transcriptomic sequencing, there were 54 differentially expressed mRNAs, including 31 upregulated and 23 downregulated mRNAs. In the exon region, 10,072 SNPs were detected, and different types of alternative splicing in the son's sample were observed. Overall, whole genome, exon mutation and transcriptomic profiling of the present two patients with AML may provide a new insight into the molecular events governing the development of AML.

[Retracted] The inhibitory effect of MEG3/miR-214/AIFM2 axis on the growth of T-cell lymphoblastic lymphoma.

Following the publication of this paper, it was drawn to the authors' attention by an interested reader that a row of the tumour images featured in Fig. 8A of the above paper were strikingly similar to those featured in Fig. 6A of an article appearing in Oncology Reports that had been published by a different research group at a different institution [Zhang L, Liang X and Li Y: Long non­coding RNA MEG3 inhibits cell growth of gliomas by targeting miR­93 and inactivating PI3K/AKT pathway. Oncol Rep 38: 2408­2416, 2017]. The Editor asked the authors for an explanation to account for the appearance of strikingly similar data in their paper independently, although the authors proved to be uncontactable in this regard, and did not respond to various queries. The Editor has therefore taken an executive decision to retract this paper from International Journal of Oncology without the agreement of the authors. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in International Journal of Oncology 51: 316­326, 2017; DOI: 10.3892/ijo.2017.4006].

Donor-derived CD19 CAR-T cell therapy of relapse of CD19-positive B-ALL post allotransplant.

Safety and efficacy of allogeneic anti-CD19 chimeric antigen receptor T cells (CAR-T cells) in persons with CD19-positive B-cell acute lymphoblastic leukemia (B-ALL) relapsing after an allotransplant remain unclear. Forty-three subjects with B-ALL relapsing post allotransplant received CAR-T cells were analyzed. 34 (79%; 95% confidence interval [CI]: 66, 92%) achieved complete histological remission (CR). Cytokine release syndrome (CRS) occurred in 38 (88%; 78, 98%) and was ≥grade-3 in 7. Two subjects died from multiorgan failure and CRS. Nine subjects (21%; 8, 34%) developed ≤grade-2 immune effector cell-associated neurotoxicity syndrome (ICANS). Two subjects developed ≤grade-2 acute graft-versus-host disease (GvHD). 1-year event-free survival (EFS) and survival was 43% (25, 62%). In 32 subjects with a complete histological remission without a second transplant, 1-year cumulative incidence of relapse was 41% (25, 62%) and 1-year EFS and survival, 59% (37, 81%). Therapy of B-ALL subjects relapsing post transplant with donor-derived CAR-T cells is safe and effective but associated with a high rate of CRS. Outcomes seem comparable to those achieved with alternative therapies but data from a randomized trial are lacking.

MiR-449a attenuates autophagy of T-cell lymphoma cells by downregulating ATG4B expression.

Increasing evidence suggests the role of miR-449a in the regulation of tumorigenesis and autophagy. Autophagy plays an important role in the malignancy of T-cell lymphoma. However, it is still unknown whether miR-449a is associated with autophagy to regulate the malignancy of T-cell lymp homa. In this study, we for the first time demonstrated that miR-449a enhanced apoptosis of T-cell lymphoma cells by decreasing the degree of autophagy. Further, miR-449a downregulated autophagy-associated 4B (ATG4B) expression, which subsequently reduced the autophagy of T-cell lymphoma cells. Mechanistically, miR-449a decreased ATG4B protein level by binding to its mRNA 3'UTR, thus reducing the mRNA stability. In addition, studies with nude mice showed that miR-449a significantly inhibited lymphoma characteristics in vivo. In conclusion, our results demonstrated that the "miR-449a/ATG4B/autophagy" pathway played a vital role in the malignancy of T-cell lymphoma, suggesting a novel therapeutic target. [BMB Reports 2020; 53(5): 254-259].

miR-203a-3p.1 is involved in the regulation of osteogenic differentiation by directly targeting Smad9 in MM-MSCs.

MicroRNAs (miRNAs) have emerged as important regulators of bone development and regeneration. The aim of the present study was to determine whether miR-203a-3p.1 is involved in osteogenic differentiation of multiple myeloma (MM)-mesenchymal stem cells (MSCs) and the potential underlying mechanism. MSCs were isolated from patients with MM and normal subjects and confirmed by flow cytometry using specific surface markers. The osteogenic differentiation capacity of MM-MSCs was identified by Alizarin Red S calcium deposition staining and reverse transcription-quantitative PCR (RT-qPCR) of typical osteoblast differentiation markers. The role of miR-203a-3p.1 in the osteoblast differentiation of MM-MSCs was determined by gain or loss of function experiments. The target of miR-203a-3p.1 was identified using bioinformatics (including the miRNA target prediction database TargetScan, miRDB, DIANA TOOLS and venny 2.1.0), luciferase reporter assay, RT-qPCR and western blotting. The expression levels of proteins involved in the Wnt3a/ß-catenin signaling pathway were detected by western blot analysis. The results revealed that the osteogenic differentiation capacity of MM-MSCs was reduced when compared with normal (N)-MSCs, as demonstrated by a decrease in calcium deposition and mRNA expression of typical osteoblast differentiation markers, including ALP, OPN and OC. In addition, miR-203a-3p.1 was downregulated in N-MSCs following osteoblast induction, whereas no changes were observed in MM-MSCs. The downregulation of miR-203a-3p.1 resulted in increased osteogenic potential, as indicated by the increase in the mRNA expression levels of the typical osteoblast differentiation markers, including alkaline phosphatase (ALP), osteopontin (OPN) and osteocalcin (OC). Bioinformatics and luciferase reporter assay analysis indicated that mothers against decapentaplegic homolog 9 (Smad9) may be a direct target of miR-203a-3p.1 in N-MSCs. The RT-qPCR and western blot assays revealed that overexpression of smad9 significantly enhanced the effect of miR-203a-3p.1 inhibitors on osteoblast markers, which indicated that miR-203a-3p.1 inhibitors may regulate the osteogenic differentiation of MM-MSCs by upregulating Smad9. In addition, the Wnt3a/ß-catenin signaling pathway was activated following miR-203a-3p.1 inhibition. These results suggest that miR-203a-3p.1 may serve an important role in the osteogenic differentiation of MM-MSCs by regulating Smad9 expression.

Inhibition of microRNA-221-5p induces osteogenic differentiation by directly targeting smad3 in myeloma bone disease mesenchymal stem cells.

Myeloma bone disease (MBD) is one of the clinical features of multiple myeloma, which contributes to the attenuation of osteoblast function. Bone marrow mesenchymal stem cells exhibit a high potential for differentiation into osteoblasts. A number of studies have reported that microRNAs (miRs) serve a vital role in mesenchymal stem cell (MSC) osteogenesis; however, the role of miR-221-5p in the osteogenic differentiation of MBD-MSCs remains unclear. The present study revealed that the osteogenic differentiation capacity of MBD-MSCs was reduced compared with that of normal (N)-MSCs. Further experiments demonstrated that miR-221-5p expression was downregulated in N-MSCs following osteoblast induction while no obvious alterations in expression levels were observed in MBD-MSCs. The inhibition of miR-221-5p promoted the osteogenic differentiation of MBD-MSCs. Bioinformatics, luciferase reporter assays, reverse transcription-quantitative PCR and western blotting assays indicated that smad family member 3 (smad3) was a direct target of miR-221-5p in MBD-MSCs. A negative association was identified between the expression levels of smad3 and miR-221-5p. Investigations of the molecular mechanism indicated that suppressed miR-221-5p could regulate the osteogenic differentiation of MBD-MSCs by upregulating smad3 expression. It was also identified that the PI3K/AKT/mTOR signaling pathway was activated following miR-221-5p inhibition, and this increased the osteogenic differentiation capacity of MBD-MSCs. The present study may improve the understanding regarding the role of miR-221-5p in the regulation of osteogenic differentiation, and may contribute to the development of a novel therapy for MBD.

MEG3 affects the progression and chemoresistance of T-cell lymphoblastic lymphoma by suppressing epithelial-mesenchymal transition via the PI3K/mTOR pathway.

Long noncoding RNAs (lncRNA) are emerging as integral functional and regulatory components in the development of different diseases including cancer. Maternally expressed gene 3 (MEG3), is a lncRNA, that has a depressed expression in multiple tumor types, including T-cell lymphoblastic lymphoma (T-LBL). However, the molecular mechanisms that regulate the tumorigenic functions of MEG3 in T-LBL remain largely unknown. In this study, we aimed to discover and identify the function of MEG3 in T-LBL tumorigenesis, epithelial-mesenchymal transition (EMT) and drug resistance, and explore their mechanisms of action. Knockdown MEG3 promoted the proliferation, migration, invasion, and drug resistance of T-LBL cells while overexpression of MEG3 gets the opposite results. The mechanism study showed that decreased MEG3 expression in T-LBL cells could activate PI3K/mTOR signaling pathways, increase the expression of p-glycoprotein and affect the expression of EMT markers for transforming to mesenchymal cells in vitro and in vivo. Together, these results indicate that MEG3 could inhibit the migration, invasion, and drug resistance in T-LBL cells by suppression of the PI3K/mTOR pathway. MEG3 might be a potential target, through which poor prognosis with high recurrence and drug resistance of T-LBL in a clinical setting could be reversed.

PD-1 blockade potentially enhances adoptive cytotoxic T cell potency in a human acute myeloid leukaemia animal model.

OBJECTIVES: Acute myeloid leukaemia (AML) is a malignant haematological disease that remains difficult to cure. Cytotoxic T cell (CTL) adoptive infusion therapy may be conducive to tumour remission by boosting physical immunity. Furthermore, programmed death receptor-1 (PD-1) blockade immunotherapy has shown tremendous success in many cancer therapies. METHOD: We attempted to combine these two immunotherapy strategies to intervene in AML by generating AML cellspecific cytotoxic T lymphocytes in vitro and in vivo with an AML cell strain expressing specific antigens. RESULTS: First, we observed that peripheral blood mononuclear cells (PBMCs) could be induced to generate large numbers of CD8+ CTL cells through immune stimulation. In addition, these CD8+ cells could effectively recognize a human AML cell line and exert cytotoxicity. In animal tests, PD-1 blockade combined with CTL infusion could induce significantly more AML tumour reduction than either treatment alone. This synergistic effect was thought to be connected to immune modulation enhancement, as regulatory T cells (Tregs) in the peripheral blood (PB) were found to be suppressed. CONCLUSIONS: This finding suggested the potential application of PD-1 blockade in AML. The present work demonstrated an excellent synergistic tumour therapeutic effect of PD-1 blockade and CTL therapy compared with either treatment alone.

Cytotoxic T lymphocytes promote cytarabine-induced acute myeloid leukemia cell apoptosis via inhibiting Bcl-2 expression.

Acute myeloid leukemia (AML) remains difficult to cure due to its drug tolerance and refractoriness. Immunotherapy is a growing area of cancer research, which has been applied for the treatment of numerous types of cancer, including leukemia. The present study generated AML cell-specific cytotoxic T lymphocytes (CTLs) in vitro and investigated the effect of combining CTL treatment with one of the most commonly used drugs for the treatment of hematological malignancies, cytarabine, on AML cell apoptosis. Firstly, it was observed that monocyte-depleted peripheral blood lymphocytes from healthy donors could be used to generate large numbers of CD3+CD8+ CTLs through immune stimulation. These CD3+CD8+ CTLs could effectively recognize and induce the apoptosis of human Kasumi-3 AML cells. In addition, cytarabine-induced AML cell apoptosis was enhanced by CTL treatment. Western blotting revealed that Bcl-2 expression was downregulated in AML cells following cytarabine and CTL treatment, indicating that the synergistic effect of this treatment on AML cell apoptosis is due to the downregulation of Bcl-2. These results highlight the potential application of CTL immunotherapy for the treatment of AML. Further studies optimizing the specificity and potency of CTLs, and identifying favorable combinations with other chemotherapeutic drug are required.