Cascade dynamic assembly/disassembly of DNA nanoframework enabling the controlled delivery of CRISPR-Cas9 system.

CRISPR-Cas9 has been explored as a therapeutic agent for down-regulating target genes; the controlled delivery of Cas9 ribonucleoprotein (RNP) is essential for therapeutic efficacy and remains a challenge. Here, we report cascade dynamic assembly/disassembly of DNA nanoframework (NF) that enables the controlled delivery of Cas9 RNP. NF was prepared with acrylamide-modified DNA that initiated cascade hybridization chain reaction (HCR). Through an HCR, single-guide RNA was incorporated to NF; simultaneously, the internal space of NF was expanded, facilitating the loading of Cas9 protein. NF was designed with hydrophilic acylamino and hydrophobic isopropyl, allowing dynamic swelling and aggregation. The responsive release of Cas9 RNP was realized by introducing disulfide bond-containing N,N-bis(acryloyl)cystamine that was specifically in response to glutathione of cancer cells, triggering the complete disassembly of NF. In vitro and in vivo investigations demonstrated the high gene editing efficiency in cancer cells, the hypotoxicity in normal cells, and notable antitumor efficacy in a breast cancer mouse model.

[Clinical Value of Genetic Susceptibility Genes for Myeloid Neoplasm in Myeloproliferative Neoplasm].

OBJECTIVE: To investigate the influence of genetic susceptibility genes for myeloid tumors on the clinical characteristics of patients with myeloproliferative neoplasm (MPN). METHODS: Two hundred and thirty-two patients with MPN diagnosed at the Second Hospital of Tianjin Medical University from September 2017 to December 2021 were collected, myeloid neoplasm-related genes were detected by targeted next-generation sequencing, and germline mutations were verified. The clinical characteristics and prognosis of MPN patients with germlines mutations in the genetic susceptibility gene for myeloid neoplasm were analyzed. RESULTS: The germline mutation carrier rate of myeloid neoplasm genetic susceptibility gene in MPN patients was 21.6% (50/232), and the PV, ET and PMF patients carrying germline mutations of genetic susceptibility gene for myeloid neoplasm were 25/114 (21.9%), 8/69 (11.6%) and 17/49 (34.7%), respectively, among which PMF patients had the highest carrier rate (P=0.01) and were older (P=0.02). The incidence of chromosomal abnormalities in MPN patients carrying the genetic susceptibitity genes for myeloid neoplasm was higher than that in the non-carrier group (26.5% vs 11.8%, P=0.05). Germline mutations in the genetic susceptibility gene of myeloid neoplasm in MPN patients were mainly concentrated in the RAS pathway, and patients with germline mutations in the genetic susceptibility gene of myeloid neoplasm associated with the RAS pathway had shorter survival without AML progression (P<0.0001). The overall survival time in MPN patients with CBL and TP53 germline mutations was shorter than that of non-carrier group (P=0.001; P=0.043). CONCLUSION: In MPN, PMF patients are more likely to carry germline mutations in the genetic susceptibility gene for myeloid neoplasm. MPN patients with germline mutations carring the genetic susceptibility gene for myeloid neoplasm are prone to chromosomal abnormalities; Patients with MPN who have germline mutations in the genetic susceptibility gene for myeloid neoplasm in the RAS pathway are more likely to develop AML; CBL and TP53 germline mutations affect the overall survival of MPN patients.

DNA-guided self-assembly in living cells.

Self-assembly processes exist widely in life systems and play essential roles in maintaining life activities. It is promising to explore the molecular fundamentals and mechanisms of life systems through artificially constructing self-assembly systems in living cells. As an excellent self-assembly construction material, deoxyribonucleic acid (DNA) has been widely used to achieve the precise construction of self-assembly systems in living cells. This review focuses on the recent progress of DNA-guided intracellular self-assembly. First, the methods of intracellular DNA self-assembly based on the conformational transition of DNA are summarized, including complementary base pairing, the formation of G-quadruplex/i-motif, and the specific recognition of DNA aptamer. Next, The applications of DNA-guided intracellular self-assembly on the detection of intracellular biomolecules and the regulation of cell behaviors are introduced, and the molecular design of DNA in the self-assembly systems is discussed in detail. Ultimately, the challenges and opportunities of DNA-guided intracellular self-assembly are commented.

Incidence and risk factors for second malignancies among patients with myeloproliferative neoplasms.

OBJECTIVE: The clinical characteristics and survival of patients with myeloproliferative neoplasms (MPNs) with secondary cancer were analyzed to explore the possible risk factors for secondary cancer in MPN patients. METHODS: The clinical characteristics of 1060 Chinese patients with MPN were retrospectively analyzed. The Kaplan-Meier method was used to analyze the survival. The Cox multivariate regression model was used to analyze the risk factors for developing secondary cancer in patients with MPNs. RESULTS: The 1060 patients with MPN had a median follow-up of 10 years (range 1-50) and a median age of 55 years (range 21-86), and 497 (45.2%) were male. The proportion of PV, ET, and PMF was 52.2%, 33.5%, and 14.3%, respectively. About 28.1% (298/1060) of 1060 MPN patients died. The median survival times of the PV, ET, and PMF groups were 20, 24, and 12 years, respectively (p < 0.0001). In age- and sex-matched healthy Chinese patients, the standardized incidence ratio (SIR) value of developing secondary cancer in MPN patients was 6.41 (95% CI: 4.90-9.48). The median survival time was 14 years in the MPN with secondary cancer group. The Cox multivariate analysis showed that age ≥ 65 years (p < 0.0001, HR = 5.027, 95% CI [2.823, 8.952]), MF-1 (p = 0.001, HR = 2.887, 95% CI [1.503, 5.545]) were risk factors for developing secondary cancer. CONCLUSIONS: The survival of MPN patients with secondary cancer was significantly worse than that of patients without secondary cancer. Compared with normal subjects, MPN patients had a 6.41-fold increased risk of developing secondary cancer, and age ≥ 65 years and MF-1 were risk factors for developing secondary cancer in MPN patients.

[Bioinformatics Analysis of Core Genes and Key Pathways in Myelodysplastic Syndrome].

OBJECTIVE: To screen differentially expressed gene (DEG) related to myelodysplastic syndrome (MDS) based on Gene Expression Omnibus (GEO) database, and explore the core genes and pathogenesis of MDS by analyzing the biological functions and related signaling pathways of DEG. METHODS: The expression profiles of GSE4619, GSE19429, GSE58831 including MDS patients and normal controls were downloaded from GEO database. The gene expression analysis tool (GEO2R) of GEO database was used to screen DEG according to | log FC (fold change) |≥1 and P<0.01. David online database was used to annotate gene ontology function (GO). Metascape online database was used to enrich and analyze differential genes in Kyoto Encyclopedia of Genes and Genomes (KEGG). The protein-protein interaction network (PPI) was constructed by using STRING database. CytoHubba and Mcode plug-ins of Cytoscape were used to analyze the key gene clusters and hub genes. R language was used to diagnose hub genes and draw the ROC curve. GSEA enrichment analysis was performed on GSE19429 according to the expression of LEF1. RESULTS: A total of 74 co-DEG were identified, including 14 up-regulated genes and 60 down regulated genes. GO enrichment analysis indicated that BP of down regulated genes was mainly enriched in the transcription and regulation of RNA polymerase II promoter, negative regulation of cell proliferation, and immune response. CC of down regulated genes was mainly enriched in the nucleus, transcription factor complexes, and adhesion spots. MF was mainly enriched in protein binding, DNA binding, and ß-catenin binding. KEGG pathway was enriched in primary immunodeficiency, Hippo signaling pathway, cAMP signaling pathway, transcriptional mis-regulation in cancer and hematopoietic cell lineage. BP of up-regulated genes was mainly enriched in type I interferon signaling pathway and viral response. CC was mainly enriched in cytoplasm. MF was mainly enriched in RNA binding. Ten hub genes and three important gene clusters were screened by STRING database and Cytoscape software. The functions of the three key gene clusters were closely related to immune regulation. ROC analysis showed that the hub genes had a good diagnostic significance for MDS. GSEA analysis indicated that LEF1 may affect the normal function of hematopoietic stem cells by regulating inflammatory reaction, which further revealed the pathogenesis of MDS. CONCLUSION: Bioinformatics can effectively screen the core genes and key signaling pathways of MDS, which provides a new strategy for the diagnosis and treatment of MDS.

Thrombosis in patients with post-polycythemia vera myelofibrosis: incidence and risk factors.

INTRODUCTION: Post-polycythemia vera (PV) myelofibrosis (Post-PV MF) is an advanced phase of natural progression of PV. Thrombosis is a major cause of morbidity and mortality in PV; however, the characteristics of thrombosis in post-PV MF have not been characterised. METHODS: The clinical and laboratory characteristics of 163 patients with post-PV MF were analysed. Kaplan-Meier and multivariate Cox analyses were used to estimate risk factors for thrombosis. RESULTS: During follow-up, 84 (51.5%) patients developed thrombosis, 11 (6.7%) progressed to acute leukemia, 35 (21.5%) died (20% due to thrombosis). Thrombosis-free survival (TFS) in post-PV MF was lower than that of sex- and age-matched patients with PV (P < 0.0001). The incidence of venous thrombosis was significantly higher after diagnosis of post-PV MF than before or at diagnosis; Those with V617F% ≥ 75% or absolute monocyte count (AMC) ≥1.5 × 109/L demonstrated a higher risk for venous thrombosis (P < 0.05). According to multivariate Cox regression, palpable splenomegaly (hazard ratio [HR] 3.284 [95% confidence interval (CI) 1.373-7.855]; P = 0.008), age ≥ 60 years (HR 1.604 [95%CI 1.004-2.56]; P = 0.048), history of thrombosis (HR 2.767 [95%CI 1.735-4.412]; P < 0.001) were risk factors for thrombosis. In multivariable models, median TFS in post-PV MF in extremely high -, high -, intermediate -, low-risk groups were 2, 4, 9 and 13 years, respectively. CONCLUSION: Patients with post-PV MF demonstrated a higher incidence of thrombosis. Palpable splenomegaly, age ≥ 60 years, history of thrombosis were independent risk factors for thrombosis.

Thrombosis among 1537 patients with JAK2V617F -mutated myeloproliferative neoplasms: Risk factors and development of a predictive model.

To explore the risk factors of thrombosis in patients with JAK2V617F -mutated myeloproliferative neoplasms (MPNs), a cohort of 1537 Chinese patients with JAK2V617F -mutated MPN was retrospectively analyzed. The Kaplan-Meier method and multivariate Cox analysis were used to study the risk factors of thrombosis in patients with JAK2V617F -mutated MPN. Among the 1537 MPN patients, 931, 468, and 138 had polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), respectively. The median follow-up time was 7 years (range 1-47), and 12.8% of patients (197/1537) died during this period. A total of 16.8% (259/1399) of PV and ET patients had secondary myelofibrosis, and 2.5% (38/1537) of patients developed acute myeloid leukemia (AML). Thrombotic events occurred in 43.9% (675/1537) of patients, among which 91.4% (617/675) were arterial thrombosis and 16.6% (112/675) were venous thrombosis. The number of thrombotic events in PV, ET, and PMF patients was 439 (47.2%), 197 (42.1%) and 39 (28.2%), respectively. The multivariate analysis indicated that age ≥60 years old, HCT ≥48%, at least one cardiovascular risk factor, a history of thrombosis, and JAK2V617F allele burden (V617F%) ≥50% are risk factors for thrombosis in JAK2V617F -mutated MPN. According to the results of the multivariate analysis, a risk model of thrombosis was established and comprised low-risk (0 points), intermediate-risk (1 points) and high-risk (≥2 points) groups, among which the incidence of thrombosis was 9.1%, 33.7% and 72.9%. For elderly patients with JAK2V617F -mutated MPN and a history of thrombosis, reducing the V617F%, controlling HCT and preventing cardiovascular risk factors are necessary measures to prevent thrombosis.

[Quantity and subtypes of dendritic cells in patients with immune related pancytopenia and their clinical significance].

This study was aimed to investigate the quantity and subtypes of dendritic cells (DC) in patients with immune related pancytopenia (IRP) and to explore the role of DC in pathogenesis of IRP. The quantity of plasmacytoid dendritic cells (pDC, Lin(-)HLA-DR(+) CD123(+) cells) and myeloid dendritic cells (mDC, Lin(-)HLA-DR(+) CD11c(+)cells) in peripheral blood of 65 patients with IRP (37 new diagnosed and 28 remitted) and 17 healthy controls were analyzed by flow cytometry. The results indicated that the ratio of pDC in peripheral blood mononuclear cells (PBMNC) was (0.91 ± 064)% in new diagnosed group, which was significantly higher than that in remission group (0.39 ± 0.11)% and control group (0.29 ± 0.13)% (P < 0.01), while this ratio of pDC in remission group was higher than that in control group (P < 0.05). The ratio of mDC in PBMNC was (0.21 ± 0.20)% in new diagnosed group and (0.34 ± 0.21)% in remission group respectively, there was no statistical difference as compared with control group (0.29 ± 0.09)% (P > 0.05). The ratio of pDC to mDC in new diagnosed group was 6.75 ± 7.11, which was significantly higher than that in remission group (1.55 ± 0.93) and control group (1.07 ± 0.43, P < 0.01), there was no statistical difference between the ratio of remission group and control group (P > 0.05). The ratio of pDC in PBMNC of IRP group negatively correlated to ratio of Th1/Th2 (r = -0.347, P < 0.05), and positively correlated to the ratio of auto-antibody on membrane of BMMNC (r = 0.606, P < 0.05) and to the quantity of CD5(+)B cells (r = 0.709, P < 0.05), while it negatively correlated to the levels of hemoglobin (r = -0.381, P < 0.01) and platelets (r = -0.343, P < 0.01). The ratio of mDC in PBMNC positively correlated to the ratio of Th1/Th2 (r = 0.595, P < 0.05) and the level of hemoglobin (r = 0.292, P < 0.05). The ratio of pDC/mDC negatively correlated to ratio of Th1/Th2 (r = -0.395, P < 0.05), it positively correlated to the level of antibody on membrane of BMMNC (r = 0.421, P < 0.05) and the quantity of CD5(+)B cells (r = 0.423, P < 0.05), while it negatively correlated to the levels of hemoglobin (r = -0.304, P < 0.05) and platelets (r = -0.287, P < 0.05). It is concluded that the quantity of pDC in peripheral blood of IRP patients increases, which may be related to the immunopathogenesis of IRP.

[Expression of CD80 and CD86 on dendritic cells of patients with immune related pancytopenia and its clinical significance].

OBJECTIVE: To investigate the function of dendritic cells (DC) of patients with immune related pancytopenia (IRP) and explore the role of DC in IRP. METHODS: The expression of CD80 and CD86 on myeloid DC (mDC, Lin-HLA-DR(+) CD11c(+) cells) and plasmacytoid DC (pDC, Lin-HLA-DR(+) CD123(+) cells) of 65 IRP (37 untreated and 28 remitted) patients and 17 healthy controls were analyzed by flow cytometry. RESULTS: The expression of CD86 on pDC was (82.47 ± 13.17)% in untreated group and (60.08 ± 14.29)% in remission group, which were significantly higher than that of controls (47.95 ± 18.59)% (P < 0.05), while the expression in untreated group was higher than that of remission group (P < 0.05). The expression of CD80 on pDC was (6.31 ± 4.49)% in untreated group, which was significantly higher than that of remitted patients (3.09 ± 2.93)% and controls (2.33 ± 2.25)% (P < 0.05). The expression of CD86 on mDC was (97.06 ± 4.82)% in untreated group and (91.35 ± 12.20)% in control group, while the expression in untreated group was higher than that of control group (P < 0.05). The expression of CD80 on mDC was (6.20 ± 5.44)% in untreated group and (3.97 ± 3.24)% in remission group, which were significantly higher than that of controls (1.86 ± 1.73)% (P < 0.05). The expression of CD86 on pDC was negatively correlated to Th1/Th2 (r = -0.733, P < 0.05), it was positively correlated to the antibody on membrane of BMMNC (r = 0.283, P < 0.05) and the quantity of CD5(+)B cells (r = 0.436, P < 0.05), while it was negatively correlated to the level of hemoglobin, platelets and white blood cells (r = -0.539, P < 0.05; r = -0.519, P < 0.05; r = -0.567, P < 0.05, respectively). The expression of CD80 on pDC was negatively correlated to the level of hemoglobin and platelets (r = -0.431, P < 0.05; r = -0.464, P < 0.05). CONCLUSION: The function of pDC in PB of IRP were strengthened, which was relevant to the immunopathogenesis of IRP.