Demethylating agents in combination with CD7-targeted CAR-T for the successful treatment of a case with mixed-phenotype acute leukemia relapsed after allogeneic hematopoietic stem cell transplantation: A Case Report.

Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has cured many patients with malignant hematologic diseases such as mixed phenotype acute leukemia (MPAL), while those relapsing after allo-HSCT still exhibit high mortality, poor prognosis, and no standard treatment modalities. It is necessary to explore more therapeutic modalities for patients with post-transplant relapse to obtain a better prognosis. Case presentation: In this case report, a young male with MPAL received allo-HSCT after reaching complete remission (CR) by induction chemotherapy. Unfortunately, relapse of both myeloid and T lineages occurred nine months later. After receiving demethylating chemotherapy, myeloid lineage measurable residual disease (MRD) turned negative. T-lineage MRD turned negative after CD7-targeted chimeric antigen receptor (CAR)-T cell therapy. The bone marrow remained MRD-negative for 4 months. This case preliminarily demonstrated a long-lasting CR with CD7-targeted CAR-T cell therapy, allowing a better prognosis. Conclusion: Demethylating drugs combined with CD7-targeted CAR-T cell therapy is feasible in treating MPAL patients with relapse after transplantation, with good efficacy and safety, which will be a promising treatment option for MPAL.

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.

[Efficacy and Safety of PEG-rhG-CSF in HSC Mobilization in 71 Normal Healthy Donors for Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To retrospectively analyze the efficacy and safety of pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) in hematopoietic stem cell mobilization in 71 normal healthy donors for allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: From March 2018 to July 2019, 71 patients received allo-HSCT in The General Hospital of Western Theater Command were enrolled in the study, a single dose of PEG-rhG-CSF was injected subcutaneously at 12 mg to all the stem cell donors. After injection for 4 days, CD34+ cell number were detected, stem cells were collected on day 4 or 5 according to the CD34+ cell number. The successful collection criteria were CD34+ cells≥2×106/kg, and the excellent collection criteria were CD34+ cells≥4×106/kg. The side effects after mobilization were observed and the collection time, the success rate, excellent rate, and times of the collection were evaluated in the donors, as well as the infused cell number, the engraftment rate, the time of engraftment, and the incidence of acute graft-versus-host disease (aGVHD) of the recipients. RESULTS: Seventy-one healthy stem cell donors included 39 males and 32 females with a median age of 38 (16-58) years old. The median number of CD34+ cells on day 4 was 46 (7.4-133)/µl, of which 39 cases with CD34+ cells ≥ 40/µl were collected on day 4, 28 cases with CD34+ cells 20-40/µl were collected on day 5, and 4 cases with CD34+ cells <20/µl were collected on day 5 after a salvage treatment with rhG-CSF. Sixty-five cases were collected once, while 6 cases twice. The median number of collected CD34+ cells was 6.1(3.1-18.1)×106/kg. The success collection rate was 100% (71/71), and the excellent collection rate was 81.6% (58/71). All the cases had varying degrees of muscle and bone soreness, 17 cases (23.9%) had headache, 11 cases (15.5%) had fatigue, and 3 cases (4.2%) had a mild fever. Among 71 recipients, the median number of infused mononuclear cells (MNC) was 8.3(5-23.3)×108/kg, the median number of infused CD34+ cells and CD3+ cells was 5.3(3.1-10.7)×106/kg and 1.9 (0.5-7.6)×108/kg, respectively. Among them, 68 cases (95.8%) had a stable engraftment, the median time of neutrophil engraftment was 11(8-19) days, and the median time of platelet engraftment was 12(8-23) days. Among the 68 cases who were engrafted, 15 cases (22%) had grade Ⅱ-Ⅳ aGVHD, including grade Ⅲ-Ⅳ aGVHD in 3 patients (4.4%), 2 cases (2.9%) died of severe aGVHD. CONCLUSION: For allo-HSCT donor mobilization, PEG-rh-G-CSF is effective, safe, and convenient, providing more options for HSC mobilization.

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.

Enhanced antitumor effect of combining chemotherapy with Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes in mice with EBV-related non-Hodgkin's lymphoma.

Epstein-Barr virus (EBV)-related non-Hodgkin's lymphoma (NHL) represents a major problem in hematological clinical studies due to its drug tolerance and refractoriness. EBV infection is a key factor driving the process of tumor growth. Immune therapy is an important biotherapeutic method of treating cancer, which is attracting increasing attention. We hypothesized that combining conventional chemotherapy with immune therapy in the treatment of EBV-related NHL may achieve better outcomes. First, we successfully cloned large numbers of EBV-specific T cells by immune stimulation ex vivo. Subsequently, the combined therapy was applied in a murine model of human EBV-related NHL. As expected, combined therapy inhibited tumor growth more effectively compared with monotherapy. In addition, we continuously tested the tumor-associated immune microenvironment and observed that the numbers of tumor-infiltrating cytotoxic T lymphocytes (CTLs) and macrophages were elevated following combined therapy. These effects suggest that EBV-specific CTLs may indirectly promote an innate immune reaction in lymphoma by activating tumor-infiltrating macrophage proliferation. Our findings may provide a guide for the prospective treatment of EBV-related NHL.