Identification of COQ2 as a regulator of proliferation and lipid peroxidation through genome-scale CRISPR-Cas9 screening in myeloma cells.

Multiple myeloma (MM) is the second most common malignant haematological disease with a poor prognosis. The limit therapeutic progress has been made in MM patients with cancer relapse, necessitating deeper research into the molecular mechanisms underlying its occurrence and development. A genome-wide CRISPR-Cas9 loss-of-function screening was utilized to identify potential therapeutic targets in our research. We revealed that COQ2 plays a crucial role in regulating MM cell proliferation and lipid peroxidation (LPO). Knockout of COQ2 inhibited cell proliferation, induced cell cycle arrest and reduced tumour growth in vivo. Mechanistically, COQ2 promoted the activation of the MEK/ERK cascade, which in turn stabilized and activated MYC protein. Moreover, we found that COQ2-deficient MM cells increased sensitivity to the LPO activator, RSL3. Using an inhibitor targeting COQ2 by 4-CBA enhanced the sensitivity to RSL3 in primary CD138+ myeloma cells and in a xenograft mouse model. Nevertheless, co-treatment of 4-CBA and RSL3 induced cell death in bortezomib-resistant MM cells. Together, our findings suggest that COQ2 promotes cell proliferation and tumour growth through the activation of the MEK/ERK/MYC axis and targeting COQ2 could enhance the sensitivity to ferroptosis in MM cells, which may be a promising therapeutic strategy for the treatment of MM patients.

PBL teaching design of medical genetics with the case of brachydactyly type A2.

Medical genetics, which is a frontier subject in biomedicine, is the clinical core of gene diagnosis and gene therapy. In the training of medical students, medical genetics plays an important role in bridging basic medicine and clinical medicine. In recent years, problem-based learning (PBL) has been widely used in medical education as an important method to cultivate the autonomous learning ability of medical students. In the current study, we designed and shared the research on brachydactyly type A2 (BDA2) as the main case of PBL teaching, in order to guide the students towards autonomous learning, and to cultivate independent analysis and problem solving ability instead of simple knowledge acquisition. Such excellent academic teaching will provide more high quality medical talents and internationally competitiveness for constructing a healthy China.

Alternative splicing analysis showed the splicing factor polypyrimidine tract-binding protein 1 as a potential target in acute myeloid leukemia therapy.

Alternative splicing (AS) is a universal post-transcriptional regulation process in cells, and increasing evidences have validated its crucial role in tumors. We collected AS event, gene expression, and clinical data of 178 AML patients from The Cancer Genome Atlas (TCGA) project. More than 1,000 AS events were found associated with overall survival (OS), and alternate promoter (AP) events were the most significant. The expression of the KIAA0930 transcript was the most significantly different AS event selected from AP events and significantly correlated with the expression of the splicing factor (SF) polypyrimidine tract-binding protein 1 (PTBP1). Then, the roles of PTBP1 on AS of the KIAA0930 and the proliferation of AML cells were confirmed. KIAA0930 variant 1 (KIAA0930-1) was upregulated and variant 2 (KIAA0930-2) downregulated with knockdown PTBP1 expression of AML cells by specific shRNA. A low level of PTBP1 can decrease the proliferation ability of AML cells. In conclusion, the results showed that PTBP1 might be a potential target for AML therapy.

Anti-Multiple Myeloma Activity of Nanobody-Based Anti-CD38 Chimeric Antigen Receptor T Cells.

Chimeric antigen receptor T cells (CAR-Ts) are a promising strategy for the treatment of many cancers, including multiple myeloma (MM), a hematological malignancy characterized by the high expression of CD38. To broaden the applications of using CD38 as a therapeutic target for the disease, we developed a new nanobody against CD38 and constructed a CD38-CAR that was composed of this nanobody as the targeting domain, and 4-1BB and CD3ζ as the costimulatory and activating domains, in a lentiviral vector. CD3+ T cells from healthy individuals were transduced with the CD38-CAR at an efficiency higher than 60%, as determined by CD38-CAR expression using flow cytometry. The CD38-CAR-Ts proliferated efficiently and produced more inflammatory cytokines, such as IL-2, IFN-γ, and TNF-α, when activated. The CD38-CAR-Ts effectively lysed CD38+ MM cell lines, including LP-1, RPMI 8226, OPM2, and MOLP8, and primary MM cells from multiple myeloma patients. The specificity was demonstrated by the fact that CD38-CAR-Ts showed little cytotoxicity on LP-1 cells with CD38 knocked out or on K562 cells, which do not express CD38. CD38-CAR-Ts appeared to have a very slight cytotoxicity against CD38+ fractions of T cells, B cells, and natural killer cells. In addition, the lysis of CD34+ hematopoietic progenitor cells did not completely inhibit the development of colony-forming units. In vivo, CD38-CAR-Ts inhibited tumor growth in NOD/SCID mice that were subcutaneously inoculated with RPMI 8226 cells. These results demonstrate that the CD38-CAR-Ts constructed with the anti-CD38 nanobody are a promising approach for the treatment of multiple myeloma.

[Tumor suppressor role of chromatin-remodeling factor ARID1A].

The mammalian SWI/SNF complex is one of ATP-dependent chromatin-remodeling complexes, which plays important roles in cell proliferation, differentiation, development and tumor suppression. ARID1A (AT-rich interactive domain-containing protein 1A) is a large subunit of SWI/SNF complex, and also an ARID family member with non- sequence-specific DNA binding activity. ARID1A is a tumor suppressor gene which is frequently mutated in many cancers, such as ovarian, bladder and gastric cancers. ARID1A can suppress cell proliferation through the up-regulation of p21 and the down-regulation of E2F-responsive genes. These findings on ARID1A and its role of tumor suppression contribute to understanding the mechanism of cancer development and developing new therapy for cancer.It is introduced in the review that ARID1A basic characteristic, related to cancer development, and biological role for full understanding of ARID1A.

Identifying susceptibility genes for essential hypertension by transcriptome-wide association study.

Hypertension is a leading risk factor of cardiovascular disease and mortality in the population worldwide. Recently, hundreds of genomic loci were reported for hypertension by GWAS, however, the most SNPs are located in intergenic regions of genome, where a functional cause is difficult to determine. In the current study, a TWAS of hypertension was conducted using 452,264 individuals including 84,640 patients. KEGG and GO enrichment analyses were performed for the hypertension-related genes identified via TWAS. PPI network analysis based on the STRING database was also performed to detect TWAS-identified genes in hypertension. We have identified 18,420 genes from the GWAS summary data, and of those 1010 non-overlapping genes expression were significantly associated with hypertension after FDR correction (PFDR <0.05) in four tissues (left heart ventricle, aorta, whole blood, and peripheral blood). The KEGG and GO terms were mostly related to autoimmune mechanisms, and the autoimmune-related pathways have also been enriched using GO analysis for PPI genes. We further performed Mendelian randomization analysis, and the results supported a significant association between autoimmunity and hypertension. Moreover, 15 novel hypertension-susceptible genes were identified in all tissues, and five of the genes (RBM6, HLA-DRB5, UHRF1BP1, LYZ, and TMEM116) were associated with autoimmune system, which provide further evidence supporting an autoimmune mechanism in hypertension. In summary, our study supports that an autoimmune mechanism plays an important role in the development of hypertension, and these findings will provide new biological insights that will assist in deciphering the molecular etiology of hypertension.

Methylome-wide association study of first-episode schizophrenia reveals a hypermethylated CpG site in the promoter region of the TNIK susceptibility gene.

Accumulating evidence suggests that epigenetics plays an important role in the etiology of schizophrenia. Here, we performed a methylome-wide association study (MWAS) of first-onset schizophrenia patients and controls from the Han Chinese population using microarray technology. The DNA methylation profiles revealed 4494 differentially methylated CpG sites. Gene ontology (GO) analysis showed that the functions of differentially methylated genes were primarily involved in enzymatic activity, cytoskeleton organization and cell adhesion, and the TNIK (encoding TRAF2- and NCK-interacting kinase) gene was enriched in most of these terms. By combining the MWAS results with those of previous genome-wide association studies (GWASs), we identified 72 candidate genes located in 49 human genome loci. Among the overlapping genes, the most significantly methylated CpG sites were in the transcriptional start site (TSS) 200 region (cg21413905, Punadjusted = 3.20 × 10-5) of TNIK. TNIK was listed in the top 50 differentially methylated loci. The results of pyrosequencing and TNIK mRNA expression were consistent with those of the microarray study. Bioinformatics analyses, dual-luciferase reporter assays and chromatin immunoprecipitation (ChIP) studies showed that TNIK interacted with genes associated with schizophrenia and NRF1 was identified as a novel transcription factor (TF) that binds to TNIK in its TSS200 region. Thus, the regulatory function of NRF1 may be influenced by the status of the methylated CpG site in this region. In summary, our study provides new insights into the epigenetic mechanisms that regulate schizophrenia. Studies of the functions of TNIK methylation should be performed in vitro and in vivo to provide a better understanding of the pathophysiology of schizophrenia.

Bioinformatic analysis of the human DHRS4 gene cluster and a proposed mechanism for its transcriptional regulation.

BACKGROUND: The human DHRS4 gene cluster consists of three genes, DHRS4, DHRS4L2 and DHRS4L1. Among them, DHRS4 encodes NADP(H)-dependent retinol dehydrogenase/reductase. In a previous study, we investigated the alternative splicing of DHRS4 and DHRS4L2. DHRS4L1 was added to the gene cluster recently, but little is known about its structure and expression. To reveal the regulatory mechanism of the DHRS4 gene cluster expression, we studied the structure and transcription of DHRS4L1 in the context of the transcriptional behaviors of the human DHRS4 gene cluster. Based on the results of bioinformatics analysis, we propose a possible mechanism for the transcriptional regulation of the human DHRS4 gene cluster. RESULTS: The homologous comparison analysis suggests that DHRS4, DHRS4L2 and DHRS4L1 are three homologous genes in human. DHRS4L1 and DHRS4L2 are paralogues of DHRS4, and DHRS4L2 is the most recent member of the DHRS4 gene cluster. In the minus strand of the human DHRS4 gene cluster, a gene transcribed in an antisense direction was found containing a 5' sequence overlapping the region of exon 1 and promoter of DHRS4. By cloning the full length of RNA variants through 5'RACE and 3'RACE, we identified two transcription start sites, within exon a2 and exon 1, of this newly named gene DHRS4L1 using neuroblastoma cell line BE(2)-M17. Analysis of exon composition in the transcripts of DHRS4 gene cluster revealed that exon 1 was absent in all the transcripts initiated from exon a1 of DHRS4L2 and exon a2 of DHRS4L1. CONCLUSIONS: Alternatively spliced RNA variants are prevalent in the human DHRS4 gene cluster. Based on the analysis of gene transcripts and bioinformatic prediction, we propose here that antisense transcription may be involved in the transcriptional initiation regulation of DHRS4 and in the posttranscriptional splicing of DHRS4L2 and DRHS4L1 for the homologous identity of DHRS4 gene cluster. Beside the alternative transcriptional start sites, the antisense RNA is novel possible factor serving to remove exon 1 from the transcripts initiated from exon a1 and exon a2.

Cordyceps sinensis mycelium extract induces human premyelocytic leukemia cell apoptosis through mitochondrion pathway.

This study was to identify the signaling pathways for the induction of HL-60 cell apoptosis by Cordyceps sinensis mycelium extract (CSME). CSME at 25 mug/ml induced nuclear fragmentation and DNA degradation, two hallmark events of apoptosis, in the HL-60 cells within 12-24 hrs of treatment. Concomitantly, several major events in the mitochondrial signal pathway occurred, including the loss of MTP (DeltaPsi(m)), cytochrome c release into the cytoplasm, the decrease in Bcl-2 protein level, the translocation of Bax protein from cytoplasm into mitochondria, and the activation of caspase-2, -3, and -9, but caspase-8, the initiator caspase in the death receptor pathway, was not activated. These results suggest that CSME induces apoptosis in HL-60 cell through the mitochondrial pathway rather than the death receptor pathway.

[Establishment of real-time fluorescent quantitative polymerase chain reaction for rapid detection of M244V mutation in kinase domain of BCR-ABL fusion gene].

The present study was aimed to establish a high sensitive and specific method for detecting M244V mutation in kinase domain of BCR-ABL(fusion gene) by using real-time quantitative PCR technology. The specific primer of the mutational site was designed, and then the PCR reaction system and condition were optimized to establish the new real-time PCR method for detecting M244V mutation. The results showed that a method of detecting M244V mutation has been successfully established. The detection results indicated that this method possessed high sensitivity, specificity and accuracy. It is concluded that the method based on fluorescent quantitative polymerase chain reaction for detecting M244V mutation can be used to detect the M244V mutation in CML patients successfully.

Identification of testosterone-/androgen receptor-regulated genes in mouse Sertoli cells.

Androgen and androgen receptor (AR) play important roles in male spermatogenesis and fertility, yet detailed androgen/AR signals in Sertoli cells remain unclear. To identify AR target genes in Sertoli cells, we analyzed the gene expression profiles of testis between mice lacking AR in Sertoli cells (S-AR(-/y)) and their littermate wild-type (WT) mice. Digital gene expression analysis identified 2276 genes downregulated and 2865 genes upregulated in the S-AR(-/y) mice testis compared to WT ones. To further nail down the difference within Sertoli cells, we first constructed Sertoli cell line TM4 with stably transfected AR (named as TM4/AR) and found androgens failed to transactivate AR in Sertoli TM4 and TM4/AR cells. Interestingly, additional transient transfection of AR-cDNA resulted in significant androgen responsiveness with TM4/AR cells showing 10 times more androgen sensitivity than TM4 cells. In the condition where maximal androgen response was demonstrated, we then analyzed gene expression and found the expression levels of 2313 genes were changed more than twofold by transient transfection of AR-cDNA in the presence of testosterone. Among these genes, 603 androgen-/AR-regulated genes, including 164 upregulated and 439 downregulated, were found in both S-AR(-/y) mice testis and TM4/AR cells. Using informatics analysis, the gene ontology was applied to analyze these androgen-/AR-regulated genes to predict the potential roles of androgen/AR in the process of spermatogenesis. Together, using gene analysis in both S-AR(-/y) mice testis and TM4/AR cells may help us to better understand the androgen/AR signals in Sertoli cells and their influences in spermatogenesis.

Inhibitory effects of ethyl acetate extract of Cordyceps sinensis mycelium on various cancer cells in culture and B16 melanoma in C57BL/6 mice.

The cultivated mycelium of a Cordyceps sinensis (Cs) fungus was sequentially extracted by petroleum ether (PE), ethyl acetate (EtOAc), ethanol (EtOH) and hot water. All solvent extracts except hot water extract showed a significant and dose-dependent inhibitory effect on the proliferation of four cancer cell lines, MCF-7 breast cancer, B16 mouse melanoma, HL-60 human premyelocytic leukemia and HepG2 human hepatocellular carcinoma, with IC(50) values below 132 microg/ml. The EtOAc extract, in particular, had the most potent effect against all four cancer cell lines, with IC(50) between 12 microg/ml (on B16) and 45 microg/ml (on MCF-7). In contrast, it had much lower cytotoxicity against normal mouse bone marrow cells. The EtOAc extract contained carbohydrates, adenosine, ergosterol and trace amount of cordycepin, of which ergosterol and related compounds were identified as a major class of active constituents contributing to the in vitro cytotoxicity. In an animal test, the EtOAc extract showed significant inhibiting effect on B16-induced melanoma in C57BL/6 mice, causing about 60% decrease of tumor size over 27 days. Our results suggest that the EtOAc extract of Cs fungal mycelium has strong anti-tumor activity and is a potential source of natural anti-tumor products.

New lignans and cytotoxic constituents from Schisandra propinqua.

The CHCl (3) extract from the stems of Schisandra propinqua (Wall.) Baill exhibited significant cytotoxic activity against cancer cell lines. Subsequent fractionation procedures led to the isolation of four new dibenzocyclooctadiene lignans, propinquanins A - D, along with two known lignans, schisantherin I and heteroclitin A, and three known triterpenoids, isoschisandrolic acid, schisandrolic acid and schisandronic acid. Their structures, including absolute stereochemistry, were elucidated through analyses of NMR data and CD spectra. The isolated compounds were tested for their cytotoxic activity in several tumor cell lines with the MTT assay. Propinquanin B ( 2) was significantly cytotoxic (IC (50) values < 10 microM) in HL-60 and Hep-G2 tumor cell lines. Cell cycle analysis and Hoechst 33 258 staining assay suggested that one possible mechanism of cytotoxic activity by 2 might be related to the induction of apoptosis.