Nanoconfined Silver Nanoclusters Combined with X-Shaped DNA Recognizer-Triggered Cascade Amplification for Electrochemiluminescence Detection of APE1.

Apurinic/apyrimidinic endonuclease 1 (APE1), as a vital base excision repair enzyme, is essential for maintaining genomic integrity and stability, and its abnormal expression is closely associated with malignant tumors. Herein, we constructed an electrochemiluminescence (ECL) biosensor for detecting APE1 activity by combining nanoconfined ECL silver nanoclusters (Ag NCs) with X-shaped DNA recognizer-triggered cascade amplification. Specifically, the Ag NCs were prepared and confined in the glutaraldehyde-cross-linked chitosan hydrogel network using the one-pot method, resulting in a strong ECL response and exceptional stability in comparison with discrete Ag NCs. Furthermore, the self-assembled X-shaped DNA recognizers were designed for APE1 detection, which not only improved reaction kinetics due to the ordered arrangement of recognition sites but also achieved high sensitivity by utilizing the recognizer-triggered cascade amplification of strand displacement amplification (SDA) and DNAzyme catalysis. As expected, this biosensor achieved sensitive ECL detection of APE1 in the range of 1.0 × 10-3 U·µL-1 to 1.0 × 10-10 U·µL-1 with the detection limit of 2.21 × 10-11 U·µL-1, rendering it a desirable approach for biomarker detection.

[Clinical Features and Prognostic Analysis of Newly Diagnosed Diffuse Large B-cell Lymphoma Combined with Hemophagocytic Syndrome].

OBJECTIVE: To compare the clinical features and prognosis between newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients with and without hemophagocytic syndrome (HPS). METHODS: The clinical data of 45 DLBCL patients in Gansu Provincial Hospital from January 2012 to December 2021 were retrospectively analyzed. The patients were divided into HPS group (15 cases) and non-HPS group (30 cases). The clinical features and prognosis of the two groups were compared, and survival analysis was performed using Kaplan-Meier method. RESULTS: Patients with HSP were mostly characterized by fever, cytopenia and splenomegaly. The levels of ferritin and soluble CD25 increased in all patients. The level of fibrinogen decreased in 66.67% patients, while triglyceride increased in 53.33% patients, and bone marrow hemophagocytosis occurred in 80.00% patients. Compared with non-HSP group, the proportions of patients with advanced stage (Ann Arbor stage III/IV) and lactate dehydrogenase (LDH) ≥240 U/L were higher in HSP group (both P < 0.05). The median survival time of HSP group was 8.0 months, which was significantly shorter than 45.5 months of non-HSP group (P < 0.001). CONCLUSION: The DLBCL patients with HPS have later Ann Arbor stage, higher LDH and shorter overall survival time compared with patients without HPS.

[Efficacy and Safety of Bendamustine in the Conditioning Regiment for Autologous Hematopoietic Stem Cell Transplantation in Patients with Lymphoma].

OBJECTIVE: To investigate the clinical efficacy and safety of bendamustine in the conditioning regimen for autologous stem cell transplantation in patients with lymphoma. METHODS: The clinical data of 35 patients with lymphoma, including 5 patients of Hodgkin lymphoma and 30 patients of non-Hodgkin lymphoma, who underwent autologous stem cell transplantation after pretreatment with BeEAM regimen from January 2020 to June 2022 in Gansu Provincial Hospital were retrospectively analyzed. Hematopoietic reconstitution, disease outcome after transplantation and the side effects were analyzed. RESULTS: All 35 patients achieved hematopoietic reconstitution after AHSCT，the median time to neutrophil engraftment was 11 (8-15) days, and the median time to platelet engraftment was 12 (9-17) days. Among the 35 patients, 4 patients died at the end of follow-up, including 3 patients died of lymphoma recurrence or progression and 1 patient died of cerebral hemorrhage. Among 34 patients, 30 had no disease progression at the end of follow-up. The OS rates of patients at 12 and 24 months after transplantation were 90.97% and 90.97%, respectively. The 12 and 24 months PFS rates were 89.64% and 84.92%, respectively. Thiry-five patients underwent grade 3-4 bone marrow suppression. The non-hematological toxicity of BeEAM pretreatment regimen mainly included nausea, vomiting, diarrhea, and oral mucositis, 35 patients experienced nausea and vomiting, but only 4 patients had grade 3-4 nausea and vomiting. Eight patients experienced Grade 1-2 diarrhea. Oral mucositis occurred in 12 patients, including 1 patient of grade 3 oral mucositis. One patient with grade 3 oral mucositis also had grade 3-4 hypokalemia and hypon atremia. 8.6% of patients experienced Grade 1-2 abnormal liver and kidney function. An addition, infectious fever occurred in 18 patients during neutropenia. All patients improved after symptomatic treatment, and there were no transplant-related death. CONCLUSION: Bendamustine as a pretreatment regimen for autologous stem cell transplantation in lymphoma is effective, and the side effects are tolerable.

[The Influence of Serum Homocysteine Level to the Prognosis of Newly Diagnosed Multiple Myeloma Patients and Analysis of Related Factors].

OBJECTIVE: To analyze the influence of serum homocysteine (Hcy) levels to the prognosis of newly diagnosed multiple myeloma (MM) patients, and to explore related factors affecting the prognosis of the patients. METHODS: The clinical pathological data of 180 newly diagnosed MM patients treated in our hospital from March 2013 to February 2015 were collected, and the patients were divided into high and low Hcy groups based on the median Hcy. The survival curves of the patients in the two groups were drawn to compare the differences of the survival; univariate and multivariate survival analysis was used to observe the influence of serum cysteine to the prognosis of newly diagnosed MM patients; the clinicopathological data of the patients with high and low Hcy in the two groups was compared, Pearson test was used to further analyzes the relationship between Hcy and different factors, and explores the related factors of Hcy affecting the prognosis of the patients. RESULTS: The median survival times of patients in the high and low Hcy groups were 32 (5-59) and 41 (7-71) months, respectively. The 3-year survival rate of the patients in high Hcy group was significantly lower than those in low Hcy group, and the difference shows statistically significant (P<0.05). The results of univariate survival analysis showed that the OS of newly diagnosed MM patients whom with advanced age, high bone disease grade, high-level bone marrow plasma cell count, LDH, C-reactive protein, Cr, ß2-MG, Hcy, low-level Hb, and ALB was significantly shortened (all P<0.05). The results of multivariate survival analysis showed that old age, high levels of bone marrow plasma cells, Cr, ß2-MG, low levels of Hb, and ALB were the independent risk factors shorting the overall survival (OS) time of newly diagnosed MM patients (all P<0.05), while Hcy showed no independent relation for the OS of patients (P>0.05). The Hb level of the patients in high Hcy group was significantly lower than those in low-Hcy group, while the LDH level was significantly higher than those in low Hcy group (all P<0.05). Pearson test results showed that serum Hcy and Hb showed negative correlation (r=-0.813, P<0.05), but it shows positive correlation with LDH (r=0.726, P<0.05). CONCLUSION: Serum Hcy level has a correlation trend with the survival of newly diagnosed MM, which is affected by factors such as Hb.

Wnt and BMP signaling pathways co-operatively induce the differentiation of multiple myeloma mesenchymal stem cells into osteoblasts by upregulating EMX2.

Osteoblast differentiation, defined as the process whereby a relatively unspecialized cell acquires the specialized features of an osteoblast, is directly linked to multiple myeloma (MM) bone disease. Wnt and bone morphogenetic protein (BMP) are proved to be implicated in the pathological or defective osteoblast differentiation process. This study aims to test the involvement of Wnt, bone morphogenetic proteins (BMP) pathways, and empty spiracles homeobox 2 (EMX2) in osteoblast differentiation and MM development. Initially, differentially expressed genes in bone marrow mesenchymal stem cells (MSCs) from MM patients and healthy donors were identified using microarray-based gene expression profiling. The functional role of Wnt and BMP in MM was determined. Next, we focused on the co-operative effects of Wnt and BMP on calcium deposition, alkaline phosphatase (ALP) activity, the number of mineralized nodules, and osteocalcin (OCN) content in MSCs. The expression patterns of Wnt and BMP pathway-related genes, EMX2 and osteoblast differentiation-related factors were determined to assess their effects on osteoblast differentiation. Furthermore, regulation of Wnt and BMP in ectopic osteogenesis was also investigated in vivo. An integrated genomic screen suggested that Wnt and BMP regularly co-operate to regulate EMX2 and affect MM. EMX2 was downregulated in MSCs. The activated Wnt and BMP resulted in more calcium salt deposits, mineralized nodules, and a noted increased in ALP activity and OCN content by upregulating EMX2, leading to induced differentiation of MSCs into osteoblasts. Collectively, this study demonstrated that Wnt and BMP pathways could co-operatively stimulate differentiation of MSCs into osteoblasts and inhibit MM progression, representing potential targets for MM treatment.

CDA gene silencing regulated the proliferation and apoptosis of chronic myeloid leukemia K562 cells.

BACKGROUND: As a disease of hematopoietic stem cell, chronic myeloid leukemia (CML) possesses unique biological and clinical features. However, the biologic mechanism underlying its development remains poorly understood. Thus, the objective of the present study is to discuss the effect of cytidine deaminase (CDA) gene silencing on the apoptosis and proliferation of CML K562 cells. METHODS: CDA mRNA expression was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and enzymatic activity of CDA was measured by a nuclide liquid scintillation method. RT-qPCR and Western blot analysis were used to detect CDA mRNA and protein expression. Cell proliferation, apoptosis and cell cycle were measured by CCK-8 assay and flow cytometry. The expression of proteins relevant to cell proliferation, apoptosis and cell cycle was measured by Western blot analysis. Tumor xenografts were implanted in nude mice to verify the effect of CDA silencing on tumor growth in vivo. RESULTS: CML and AL patients showed increased mRNA expression and enzymatic activity of CDA. Compared with the blank group, the mRNA and protein expression of CDA in the shRNA-1 and shRNA-2 groups decreased significantly. As a result, the proliferation of K562 cells was inhibited after CDA silencing and the cells were mainly arrested in S and G2 phases, while the apoptosis rate of these cells was increased. In addition, CDA gene silencing in K562 cells led to down-regulated p-ERK1/2, t-AKT, p-AKT and BCL-2 expression and up-regulated expression of P21, Bax, cleaved caspase-3/total caspase-3 and cleaved PARP/total PARP. Finally, CDA gene silencing inhibited tumor growth. CONCLUSION: Our study demonstrated that CDA gene silencing could inhibit CML cell proliferation and induce cell apoptosis. Therefore, CDA gene silencing may become an effective target for the treatment of leukemia.

[Inhibition of HLA-DRB1*0405 gene expression by siRNA].

OBJECTIVE: To investigate the effects of small interfering RNA (siRNA) of HLA DRB1(*)0405 HLA-DRB1(*)0405 gene expression with plasmid-based siRNAs. METHOD: Plasmid expressing HLA-DRB1(*)0405-renilla fusion protein-siCHECK-2/HLA-DRB1(*)0405, 6 different short hairpin RNAs (shRNAs) targeting 6 19 bp nucleotide sequences of HLA-DRB1(*)0405 (siRNA1 approximately 6), and one shRNA targeting the control non-specific sequence (siRNAC) were designed and constructed. Human embryonic kidney cells of the line 293 were cultured and co-transfected by lipids some with the plasmid siCHECK-2/HLA-DRB1(*)0405 and one specific shRNA expressing vector transiently, and cells without shRNA-transfection were used as negative controls. The impact of RNAi on HLA-DRB1(*)0405 expression was analyzed by real time fluorescence quantification RT-PCR and luciferase test. RESULTS: The expression of HLA-DRB1(*)0405 gene RNA of the 293 cells transfected with siRNA1, siRNA2, siRNA3, siRNA, and siRNA6 were down-regulated to 10.75%, 83.22%, 30.63%, 48.54%, and 89.92% that of the control group with the inhibition rates of 89.25%, 16.78%, 69.37%, 51.46%, and 10.08% respectively. However, no significant downregulation was showed in the cells transfected with siRNA4 and siRNAC. The 293 cells transfected with siRNA1 and siRNA 3 showed a significant downregulation of the protein expression of HLA-DRB1(*)0405 gene with the inhibitory rates of 6.70% and 36.85% respectively; however, the cells transfected with siRNA2, siRNA4, siRNA5, and siRNA6 did not show a significant downregulation. CONCLUSION: The significant inhibition of HLA-DRB1(*)0405 gene expression by siRNA suggests a therapeutic approach in rheumatoid arthritis: to use RNA interference (RNAi) to inhibit the abnormal immune reaction mediated by HLA-DRB1 in rheumatoid arthritis.

[Molecular cloning and identification and biological activity of GIF-interacting protein(s)].

In order to examine the elusive functional mechanism of GIF (Neuronal growth inhibitory factor, GIF) and elucidate the possible relationship between GIF and Alzheimer's disease, we constructed bait1 plasmid (pHyblex-GIF) by cloning GIF cDNA directly in frame with plasmid pHyblex, and used the yeast two-hybrid system to screen Alzheimer's disease human brain cDNA library and found the GIF-interacting proteins. The final results from coimmunoprecipitation and western blotting experiments confirmed that interacting proteins specifically binds to GIF. After sequencing the nucleotide of the putative positive plasmids and searching for homologues, we found that one of these is the part of human nuclear dUTPase protein sequence. Then the dUTPase genes are cloned into pGEX-4T-1, the fusion expression vector of GST,and highly expressed in E. coli BL21. The proteins dUTPase and GIF were purified and obtained by affinity chromatography, thrombin digestion and gel filtration on Sephacryl S100. It demonstrated that the proteins dUTPase and GIF had the growth inhibitory activity on co-cultured neuron in vitro. The inhibitory curve was very similar to the GIF. It's possible that dUTPase is one of the proteins interacting with GIF in Alzheimer's disease human brain extracts.

[Affection of metallothionein-3 to dUTPase's accommodating cellular toxicity of dUTP].

Metallothionein-3 (MT-3), renamed as growth inhibitory factor (GIF), is a brain specific member of the metallothionein family. Human dUTPase is a recently found protein in brain that can interact with hMT-3. They have the growth inhibitory activity on neuron cell by interaction. To study the affection of hMT-3 to dUTPase's eliminating the cellular toxicity caused by dUTP, the pSVHA-dUTPase and pFLag-hMT-3 genes have been transfected into HEK293 cells. In addition, the dUTPase and hMT-3 proteins were expressed in BL21 to study the role of hMT-3 on the hydrolyzation of dUTP by dUTPase. The results demonstrate that the cells co-transfected with dUTPase and hMT-3 genes have more strong resistibility to dUTP than the cells transfected only with dUTPase gene. And that the hMT-3 protein can accelerate the hydrolyzation of dUTP by dUTPase. All these indicate that hMT-3 can cooperate with dUTPase to protect better the 293 cells from dUTP. This research offered the theoretic elements for the application of hMT-3 and dUTPase in chemic cure.