KIF22 promotes multiple myeloma progression by regulating the CDC25C/CDK1/cyclinB1 pathway.

PURPOSE: Multiple myeloma (MM) is an incurable hematological malignancy characterized by clonal proliferation of malignant plasma B cells in bone marrow, and its pathogenesis remains unknown. The aim of this study was to determine the role of kinesin family member 22 (KIF22) in MM and elucidate its molecular mechanism. METHODS: The expression of KIF22 was detected in MM patients based upon the public datasets and clinical samples. Then, in vitro assays were performed to investigate the biological function of KIF22 in MM cell lines, and subcutaneous xenograft models in nude mice were conducted in vivo. Chromatin immunoprecipitation (ChIP) and luciferase reporter assay were used to determine the mechanism of KIF22-mediated regulation. RESULTS: The results demonstrated that the expression of KIF22 in MM patients was associated with several clinical features, including gender (P = 0.016), LDH (P < 0.001), ß2-MG (P = 0.003), percentage of tumor cells (BM) (P = 0.002) and poor prognosis (P < 0.0001). Furthermore, changing the expression of KIF22 mainly influenced the cell proliferation in vitro and tumor growth in vivo, and caused G2/M phase cell cycle dysfunction. Mechanically, KIF22 directly transcriptionally regulated cell division cycle 25C (CDC25C) by binding its promoter and indirectly influenced CDC25C expression by regulating the ERK pathway. KIF22 also regulated CDC25C/CDK1/cyclinB1 pathway. CONCLUSION: KIF22 could promote cell proliferation and cell cycle progression by transcriptionally regulating CDC25C and its downstream CDC25C/CDK1/cyclinB1 pathway to facilitate MM progression, which might be a potential therapeutic target in MM.

Pan-cancer analysis of DDIT4 identifying its prognostic value and function in acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is a hematological malignancy derived from the accumulation of abnormal proliferation of infantile leukocytes in the hematopoietic system. DNA-damage-inducible transcript 4 (DDIT4) acting as a negative regulator of rapamycin inhibitor is involved in various cellular functions. Many studies have suggested that DDIT4 plays a key role in tumorigenesis. However, the role of DDIT4 in AML has been poorly studied. METHOD: In this study, we analyzed the expression of DDIT4 in AML patients using The Cancer Genome Atlas and real-time polymerase chain reaction. The Chi-square test was used to assess the correlation between DDIT4 and clinical characters in AML patients. Loss-of-function experiments were implemented to investigate the role of DDIT4 in AML carcinogenesis. The R package was applied to evaluate the correlation between DDIT4 expression and immune cells. RESULTS: Results showed that the expression of DDIT4 was associated with Age, Cytogenetic risk, Cytogenetics and OS event. Moreover, high expression of DDIT4 led to a terrible prognosis. KEGG analysis showed that differently expressed genes (DEGs) were involved in the PI3-Akt signaling pathway. GSEA enrichment analysis displayed DEGs were correlated with apoptosis. Functional experiments presented that knocking down DDIT4 suppressed cell cycle transition/proliferation and facilitated apoptosis. In addition, DDIT4 is associated with immune infiltration. CONCLUSION: Our research verified that DDIT4 can be used as a prognostic marker and a potential therapeutic target for AML.

BATF promotes extramedullary infiltration through TGF-ß1/Smad/MMPs axis in acute myeloid leukemia.

Acute myeloid leukemia (AML) is one of the most prevalent types of leukemia and is challenging to cure for most patients. Basic Leucine Zipper ATF-Like Transcription Factor (BATF) has been reported to participate in the development and progression of numerous tumors. However, its role in AML is largely unknown. In this study, the expression and prognostic value of BATF were examined in AML. Our results demonstrated that BATF expression was upregulated in AML patients, which was significantly correlated with poor clinical characteristics and survival. Afterward, functional experiments were performed after knocking down or overexpressing BATF by transfecting small interfering RNAs and overexpression plasmids into AML cells. Our findings revealed that BATF promoted the migratory and invasive abilities of AML cells in vitro and in vivo. Moreover, the target genes of BATF were searched from databases to explore the binding of BATF to the target gene using ChIP and luciferase assays. Notably, our observations validated that BATF is bound to the promoter region of TGF-ß1, which could transcriptionally enhance the expression of TGF-ß1 and activate the TGF-ß1/Smad/MMPs signaling pathway. In summary, our study established the aberrantly high expression of BATF and its pro-migratory function via the TGF-ß1-Smad2/3-MMP2/9 axis in AML, which provides novel insights into extramedullary infiltration of AML.

Circular RNA circXPO1 Promotes Multiple Myeloma Progression by Regulating miR-495-3p/DNA Damage-Induced Transcription 4 Axis.

Multiple myeloma (MM) is a hematologic malignancy that results from uncontrolled plasma cell proliferation. Circular RNAs are versatile regulators that influence cancer aggression. The pathogenic mechanism of circXPO1 in MM is still unknown. In this study, the expression of circXPO1, miR-495-3p, and DNA damage-induced transcription 4 (DDIT4) was detected. Knockdown and overexpression assays were used to evaluate the effect of circXPO1 on MM. Specifically, 5-ethynyl-2'-deoxyuridine and cell counting kit-8 assay were used to investigate cell proliferation. Meanwhile, flow cytometry was adopted to detect cell apoptosis and cell cycle. Apoptosis-associated and cell cycle-related proteins were detected by Western blot. Mechanistically, biotin RNA pull-down assay and dual-luciferase assay were implemented to verify the combination among miR495-3p and circXPO1 or DDIT4. The function of circXPO1 in vivo was explored in xenograft experiments. The results showed that circXPO1 was up-regulated in both MM samples and MM cell lines and miR-495-3p was down-regulated in MM patients. Silencing circXPO1 inhibited cell proliferation, increased apoptosis rates, and caused the G1 phase arrest. Overexpression of circXPO1 yielded opposite results. In addition, RNA pull-down experiment demonstrated the interaction between circXPO1 and miR-495-3p. Silencing miR-495-3p rescued the inhibitory function caused by the knockdown of circXPO1. DDIT4 was the target of miR-495-3p. Finally, silencing circXPO1 inhibited the growth of subcutaneous tumors in vivo. In conclusion, our findings showed that circXPO1 could promote MM progression via the miR-495-3p/DDIT4 axis.

RNA modification regulator DDC in endometrial cancer affects the tumor microenvironment and patient prognosis.

Uterine corpus endometrial carcinoma (UCEC) is infiltrated by immune cells, which are involved in the growth and proliferation of malignant tumors and resistance to immunotherapy. This study suggested that RNA modification regulators played an important role in the development and prognosis of UCEC. Many studies confirmed that RNA modification played an essential role in tumor immune regulation, and abnormal RNA modification contributed to tumorigenesis and cancer progression. Based on the RNA modification regulatory factors, the UCEC samples from TCGA (The Cancer Genome Atlas) were classified into two clusters, namely Cluster A and Cluster B, using unsupervised consensus clustering. We obtained DEG (differentially expressed genes) between the two clusters, and constructed a risk model of RNA modification-related genes using DEGs. Cluster A had lower RNA modification regulatory factors, richer immune cell infiltration, and better prognosis. The differentially expressed genes between the two clusters were obtained, and these genes were used for modeling. This model divided patients with UCEC into two groups. The low-risk group had better immune infiltration, and the ROC (receiver operating characteristic) curve showed that this model had good predictive efficacy. The low-risk group had a better response to immunotherapy by immune checkpoint prediction. We obtained the key gene L-dopa decarboxylase (DDC) through the intersection of LASSO model genes and GEO dataset GSE17025. We evaluated the potential biological functions of DDC. The differences in the expression of DDC were verified by immunohistochemistry. We evaluated the relationship between DDC and immune cell infiltration and verified this difference using immunofluorescence. Cluster A with low expression of RNA modification regulators has better prognosis and richer immune cell infiltration, therefore, we believed that RNA modification regulators in UCEC were closely related to the tumor microenvironment. Also, the risk score could well predict the prognosis of patients and guide immunotherapy, which might benefit patients with UCEC.

Adrenomedullin induces cisplatin chemoresistance in ovarian cancer through reprogramming of glucose metabolism.

Background and Objectives: The metabolic network of cancer cells has been reprogrammed - relying more on aerobic glycolysis to gain energy, which is an important reason for drug resistance. Expression of adrenomedullin (ADM) in ovarian cancer tissues is related to resistance to platinum-based drugs. In view of this, we intended to investigate the correlation between ADM and glucose metabolism reprogramming of tumor cells to clarify the possible mechanism of ADM-induced ovarian cancer cisplatin resistance through glucose metabolism reprogramming. Methods: Epithelial ovarian cancer (EOC) cell viability and apoptosis were determined. Different gene expression and protein levels were detected by real-time revere transcription polymerase chain reaction and western blotting. Oxygen consumption rate (OCR) and extracellular acidification rates (ECARs) were measured. Results: ADM expression was upregulated in cisplatin-resistant EOC cells. ADM attenuated cisplatin-inhibited cell survival and cisplatin-induced apoptosis in sensitive EOC cells; knockdown of ADM enhanced cisplatin chemosensitivity of cisplatin-resistant EOC cells. ADM enhanced glycolysis in cisplatin-sensitive EOC cells; knockdown of ADM significantly inhibited glycolysis in cisplatin-resistant EOC cells. ADM significantly upregulated pyruvate kinase isozyme type M2 (PKM2) protein level, the key enzyme during glycolysis; PKM2 inhibitor significantly abolished the ADM-improved cell survival and ADM-inhibited apoptosis. Conclusion: ADM promoted proliferation and inhibited apoptosis of ovarian cancer cells through reprogramming of glucose metabolism, so as to promote cisplatin resistance. The study is expected to identify multidrug resistance markers of ovarian cancer and provide a target for the prevention and treatment of ovarian cancer, which is important for clinical translational research.

N6-methyladenosine reader YTHDF2 promotes multiple myeloma cell proliferation through EGR1/p21cip1/waf1/CDK2-Cyclin E1 axis-mediated cell cycle transition.

Multiple myeloma (MM) is the second most common hematological malignancy. N6-methyladenosine (m6A) is the most abundant RNA modification. YTH domain-containing family protein 2 (YTHDF2) recognizes m6A-cotaining RNAs and accelerates degradation to regulate cancer progression. However, the role of YTHDF2 in MM remains unclear. We investigated the expression levels and prognostic role of YTHDF2 in MM, and studied the effect of YTHDF2 on MM proliferation and cell cycle. The results showed that YTHDF2 was highly expressed in MM and was an independent prognostic factor for MM survival. Silencing YTHDF2 suppressed cell proliferation and caused the G1/S phase cell cycle arrest. RNA immunoprecipitation (RIP) and m6A-RIP (MeRIP) revealed that YTHDF2 accelerated EGR1 mRNA degradation in an m6A-dependent manner. Moreover, overexpression of YTHDF2 promoted MM growth via the m6A-dependent degradation of EGR1 both in vitro and in vivo. Furthermore, EGR1 suppressed cell proliferation and retarded cell cycle by activating p21cip1/waf1 transcription and inhibiting CDK2-cyclinE1. EGR1 knockdown could reverse the inhibited proliferation and cell cycle arrest upon YTHDF2 knockdown. In conclusion, the high expression of YTHDF2 promoted MM cell proliferation via EGR1/p21cip1/waf1/CDK2-cyclin E1 axis-mediated cell cycle transition, highlighting the potential of YTHDF2 as an effective prognostic biomarker and a promising therapeutic target for MM.

The Role of Mental Adjustment in Mediating Post-Traumatic Stress Disorder Symptoms and Social Support in Chinese Ovarian Cancer Patients: A Cross-Sectional Study.

Background: Post-traumatic stress disorder (PTSD) can manifest in individuals following a traumatic event. There is a paucity of studies focusing on PTSD symptoms in ovarian cancer (OC) patients. This study aimed to investigate the association of social support, mental adjustment and PTSD symptoms in Chinese OC patients with a view to exploring whether mental adjustment could mediate the relationship. Methods: A cross-sectional study was conducted from January 2015 to December 2016. A total of 171 OC subjects were recruited and the effective response rate was 81.3%. The PTSD Checklist-Civilian Version (PCL-C), Mini-Mental Adjustment to Cancer scale (Mini-MAC) and Duke-UNC Functional Social Support Questionnaire were disseminated to the patients. The Chinese Mini-MAC was used in this study focusing on three components, namely negative emotion, positive attitude, and cognitive avoidance. Hierarchical linear regression analyses were employed to investigate the association of social support and PTSD symptoms, and the role of mental adjustment in their mediation. Results: The prevalence of PTSD symptoms was 17.3% in OC patients. PTSD symptoms were negatively related with both social support and positive attitude, and positively associated with negative emotion and cognitive avoidance. Social support was negatively associated with negative emotion and cognitive avoidance, and positively related with positive attitude. In addition, negative emotion and positive attitude mediated the association between social support and PTSD symptoms. Conclusion: PTSD symptoms in OC patients should be paid attention to. Social support and mental adjustment were positive resources associated with PTSD symptoms. Moreover, mental adjustment could mediate the relation between social support and PTSD symptoms in OC patients. Therefore, intervention management that focusing on improving perceived social support as well as strengthening mental adjustment, especially negative emotion and positive attitude, may be useful for reducing PTSD symptoms in this context.

Using Circ-ANAPC7 as a Novel Type of Biomarker in the Monitoring of Acute Myeloid Leukemia.

INTRODUCTION: Circular RNAs (circRNAs) are a novel class of RNAs which occupy gene expression at the transcriptional or post-transcriptional level, involve in many physiological processes, and participate in many diseases, especially in cancer. Our previous study showed 1 altered circRNA named circ-anaphase promoting complex subunit 7 (ANAPC7) that was upregulated in acute myeloid leukemia (AML). To further clear the expression and clinical significance of circ-ANAPC7, we enlarged the sample size and illuminated the diagnostic and monitoring value of circ-ANAPC7 in AML. METHODS: Real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was supposed to confirm the expression of circ-ANAPC7 of AML patients. We assessed the correlation of circ-ANAPC7 and clinical variables using the Spearman correlation test. The receiver operating characteristic (ROC) curve was carried out to evaluate the diagnostic value. RESULTS: Circ-ANAPC7 was first found to be upregulated in AML, and its expression was correlated to white blood cell counts in peripheral blood and blast percentage in bone marrow. ROC curve analysis revealed that circ-ANAPC7 has a significant value of auxiliary AML diagnosis (area under the curve = 0.915, p < 0.001). Furthermore, the expression level of circ-ANAPC7 was changed accompanied with disease condition transformation. CONCLUSION: Circ-ANAPC7 was upregulated in newly diagnosed and relapsed AML. It may serve as potential biomarkers for AML patient's diagnosis and monitoring.

PSMB7 Is a Key Gene Involved in the Development of Multiple Myeloma and Resistance to Bortezomib.

Multiple myeloma (MM), the second most commonly diagnosed hematologic neoplasm, is the most significant clinical manifestation in a series of plasma cell (PC) dyscrasia. Monoclonal gammopathy of undetermined significance (MGUS) and smoldering MM (SMM), approximately 1% or 10% of which, respectively, can progress to MM per year, are the premalignant stages of MM. The overall survival (OS) of MM is significantly improved by the introduction of proteasome inhibitors (PIs), but almost all MM patients eventually relapse and resist anti-MM drugs. Therefore, it is crucial to explore the progression of MM and the mechanisms related to MM drug resistance. In this study, we used weighted gene co-expression network analysis (WGCNA) to analyze the gene expression of the dynamic process from normal plasma cells (NPC) to malignant profiling PC, and found that the abnormal gene expression was mainly concentrated in the proteasome. We also found that the expression of one of the proteasomal subunits PSMB7 was capable of distinguishing the different stages of PC dyscrasia and was the highest in ISS III. In the bortezomib (BTZ) treated NDMM patients, higher PSMB7 expression was associated with shorter survival time, and the expression of PSMB7 in the BTZ treatment group was significantly higher than in the thalidomide (Thai) treatment group. In summary, we found that PSMB7 is the key gene associated with MM disease progression and drug resistance.

lncRNA ST3GAL6­AS1 promotes invasion by inhibiting hnRNPA2B1­mediated ST3GAL6 expression in multiple myeloma.

Multiple myeloma (MM) is an incurable disease caused by the infiltration of malignant plasma B cells into bone marrow, whose pathogenesis remains largely unknown. Long non­coding RNAs (lncRNAs) have emerged as important factors in pathogenesis. Our previous study validated that lncRNA ST3 ß­galactoside α­2,3­sialyltransferase 6 antisense RNA 1 (ST3GAL6­AS1) was upregulated markedly in MM. Therefore, the aim of the study was to investigate the molecular mechanisms of ST3GAL6­AS1 in MM cells. ST3GAL6­AS1 expression levels in MM cells was detected using reverse transcription­quantitative PCR. ST3GAL6­AS1 antisense oligonucleotides and small interfering RNAs were transfected into MM cells to downregulate expression. In vitro assays were performed to investigate the functional role of ST3GAL6­AS1 in MM cells. RNA pull­down, RNA immunoprecipitation and comprehensive identification of RNA­binding proteins using mass spectrometry assays were used to determine the mechanism of ST3GAL6­AS1­mediated regulation of underlying targets. It was reported that knockdown of ST3GAL6­AS1 suppressed the adhesion, migration and invasion ability of MM cells in vitro. Expression of ST3GAL6 was significantly reduced when ST3GAL6­AS1 was knock downed in MM cells. Moreover, mechanistic investigation showed that ST3GAL6­AS1 could suppress ST3GAL6 mRNA degradation via interacting with heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1). The present results suggested that upregulated lncRNA ST3GAL6­AS1 promotes adhesion and invasion of MM cells by binding with hnRNPA2B1 to regulate ST3GAL6 expression.

CD138- multiple myeloma cells express high level of CHK1 which correlated to overall survival in MM patient.

Multiple myeloma (MM) is a disease in which abnormal plasma cells proliferate and secrete monoclonal immunoglobulin in the bone marrow. The main characteristic of plasma cells is the expression of the cell surface antigen syndecan-1 (CD138). However, the expression of CD138 is limited to terminally differentiated plasma cells during B cell development. A small subpopulation (2~5%) of human MM cells that lack CD138 expression has been shown to possess enormous proliferation potential in vitro experiment and in animal models, and they also can differentiate into CD138+ plasma cells. Thus, this small subset of MM cells was regarded as myeloma cancer stem cell (MCSC). However, its characteristics associated with the pathogenesis of MM remain unclear. In this study, we analyzed the gene expression data of CD138 cell lines downloaded from Gene Expression Omnibus (GEO) database. Limma package in RStudio was used to identify differentially expressed genes (DEGs). Genes enrichment and protein-protein interaction (PPI) network analysis were performed on DAVID and STRING databases. Furthermore, overall survival (OS) analysis in MM patient was utilized to screen out the hub-genes closely associate with the MM pathogenesis process. Hub-genes expression validation and receiver operating characteristic curve (ROC) analysis was performed in different stages of plasma cell disorder diseases. Finally, we verified these findings in MM patient samples. Through integrated bioinformatics analysis of MM CD138- and CD138+ cell lines, we found that CDC7, CDK1, and CHK1 are highly expressed in CD138- MM cells. These genes are crucial in the G2/M phase of the cell cycle pathway, which is closely related to the malignant proliferation in various tumor cells. Of note, we found that patients with high expression of CDC7, CDK1, and CHK1 had shorter overall survival time. The expression of CHK1 was significantly increased in MM cells compared with normal plasma cell (NPC) and MGUS. More importantly, we further clarified that the expression of CHK1 in release/refraction MM (R/R MM) has obviously increased compared with new diagnosed MM (ND MM).

Pluronic® F127 stabilized reduced graphene oxide hydrogel for the treatment of psoriasis: In vitro and in vivo studies.

Psoriasis is a chronic inflammatory disease that can be effectively treated using topical cyclosporine. However, topical delivery is extremely challenging owing to the physicochemical nature of cyclosporine, as well as the thick psoriatic stratum corneum. In the present study, for the first time, we attempted to formulate a cyclosporine-loaded Pluronic® F127 stabilized reduced graphene oxide hydrogel to improve cyclosporine permeation and retention in the affected tissue for effective psoriasis treatment. The attachment of Pluronic® F127 on reduced graphene oxide was confirmed using Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction. The scanning electron microscopy image demonstrated a wrinkled and flattened nanosheet surface with Pluronic® F127 micelles. Ex vivo permeation data demonstrated an increase in cyclosporine permeation with increasing levels of reduced graphene oxide in the hydrogel. The hydrogel showed sufficient mechanical properties (texture analyzer report) for topical application, without any sign of irritation on rabbit skin. In the drug retention study, the C-P-rGO-500 hydrogel demonstrated maximum drug trapping inside the skin tissue. In the efficacy study in mice, the C-P-rGO-500 hydrogel decreased hyperplasia and tissue damage in psoriatic skin. Thus, the ability of the reduced graphene oxide nanocarrier to improve cyclosporine permeation, as well as retention in skin tissue, could be successfully utilized for effective psoriasis treatment, minimizing side effects encountered with oral and systemic routes.

Identification of key biomarkers associated with cell adhesion in multiple myeloma by integrated bioinformatics analysis.

BACKGROUND: Multiple Myeloma (MM) is a hematologic malignant disease whose underlying molecular mechanism has not yet fully understood. Generally, cell adhesion plays an important role in MM progression. In our work, we intended to identify key genes involved in cell adhesion in MM. METHODS: First, we identified differentially expressed genes (DEGs) from the mRNA expression profiles of GSE6477 dataset using GEO2R with cut-off criterion of p < 0.05 and [logFC] ≥ 1. Then, GO and KEGG analysis were performed to explore the main function of DEGs. Moreover, we screened hub genes from the protein-protein interaction (PPI) network analysis and evaluated their prognostic and diagnostic values by the PrognoScan database and ROC curves. Additionally, a comprehensive analysis including clinical correlation analysis, GSEA and transcription factor (TF) prediction, pan-cancer analysis of candidate genes was performed using both clinical data and mRNA expression data. RESULTS: First of all, 1383 DEGs were identified. Functional and pathway enrichment analysis suggested that many DEGs were enriched in cell adhesion. 180 overlapped genes were screened out between the DEGs and genes in GO terms of cell adhesion. Furthermore, 12 genes were identified as hub genes based on a PPI network analysis. ROC curve analysis demonstrated that ITGAM, ITGB2, ITGA5, ITGB5, CDH1, IL4, ITGA9, and LAMB1 were valuable biomarkers for the diagnosis of MM. Further study demonstrated that ITGA9 and LAMB1 revealed prognostic values and clinical correlation in MM patients. GSEA and transcription factor (TF) prediction suggested that MYC may bind to ITGA9 and repress its expression and HIF-1 may bind to LAMB1 to promote its expression in MM. Additionally, pan-cancer analysis showed abnormal expression and clinical outcome associations of LAMB1 and ITGA9 in multiple cancers. CONCLUSION: In conclusion, ITGA9 and LAMB1 were identified as potent biomarkers associated with cell adhesion in MM.

IGF-1 promotes multiple myeloma progression through PI3K/Akt-mediated epithelial-mesenchymal transition.

AIMS: To investigate the role and mechanism of insulin-like growth factor 1(IGF-1)-mediated EMT on multiple myeloma (MM) growth and metastasis. MATERIALS AND METHODS: The expression data from GEO datasets were utilized to explore the expression levels of IGF-1 and epithelial-mesenchymal transition (EMT) markers in MM. Western blotting and flow cytometry analysis were performed to detect the protein levels of EMT markers as well as key components of the PI3K/Akt pathway. Cell proliferation ability was assessed using colony formation assay and EdU incorporation assays. Transwell migration and invasion assays were performed to assess cell metastasis properties. Vimentin was knocked down by using electro-transfection with small interfering RNA (siRNA) to detect the effect of IGF-1-mediated EMT on MM cell growth and metastasis. KEY FINDINGS: First of all, the analysis of GEO database revealed that IGF-1 was excessively expressed and closely correlated with the expression of the EMT markers in MM patients. Furthermore, we demonstrated that IGF-1 enhanced the acquisition of mesenchymal features in a time-dependent manner. Additionally, in vitro studies revealed that IGF-1-mediated mesenchymal phenotype promoted MM migration, invasion and colony formation. Finally, the mechanism study showed PI3K/Akt signaling pathway was involved in the IGF-1-induced EMT in MM cells. SIGNIFICANCE: IGF-1-induced mesenchymal phenotype contributed to MM progression via the PI3K/Akt pathway regulation.

Blockade of HSP70 by VER-155008 synergistically enhances bortezomib-induced cytotoxicity in multiple myeloma.

Proteasome inhibitor bortezomib is one of the most effective drugs currently available for the treatment of multiple myeloma (MM). However, the intrinsic and acquired resistance to bortezomib can limit its effectiveness. The activation of heat shock response has been characterized as a potential resistance mechanism protecting MM cells from bortezomib-induced cell death. In this study, in response to bortezomib therapy, we discovered that HSP70 is one of the most substantially upregulated heat shock proteins. In order to further explore approaches to sensitizing bortezomib-based treatment for MM, we investigated whether targeting HSP70 using a specific inhibitor VER-155008 combined with bortezomib could overcome the acquired resistance in MM. We found that HSP70 inhibitor VER-155008 alone significantly decreased MM cell viability. Moreover, the combination of VER-155008 and bortezomib synergistically induced MM cell apoptosis markedly in vitro. Notably, the combined treatment was found to increase the cleavage of PARP, an early marker of chemotherapy-induced apoptosis. Importantly, the reduction of anti-apoptotic Bcl-2 family member Bcl-2, Bcl-xL, and Mcl-1 and the induction of pro-apoptotic Bcl-2 family member BH3-only protein NOXA and Bim were confirmed to be tightly associated with the synergism. Finally, the ER stress marker CHOP (CCAAT-enhancer binding protein homologous protein), which can cause transcriptional activation of genes involved in cell apoptosis, was markedly induced by both VER-155008 and bortezomib. Taken together, our finding of a strong synergistic interaction between VER-155008 and bortezomib may support for combination therapy in MM patients in the future.

High Expression Levels of Long Noncoding RNA Small Nucleolar RNA Host Gene 18 and Semaphorin 5A Indicate Poor Prognosis in Multiple Myeloma.

BACKGROUND: The aim of this study was to detect the expression of long noncoding RNA small nucleolar RNA host gene 18 (SNHG18) andsemaphorin 5A (SEMA5A) genes in multiple myeloma (MM) patients and to explore the correlation of the expression of these genes with the clinical characteristics and prognosis of MM patients. METHODS: Forty-seven newly diagnosed MM, 18 complete remission MM, 13 refractory/relapse MM, and 22 iron deficiency anemia (serving as control) samples were extracted at the Department of Hematology, Second Affiliated Hospital of Xian Jiaotong University between January 2015 and December 2016. The clinical features of the MM patients are summarized. Real-time quantitative PCR was performed to analyze the relative expression levels of the SNHG18 and SEMA5Agenes. The clinical characteristics and overall survival (OS) of the MM patients were statistically analyzed while measuring different levels of SNHG18 and SEMA5Agene expression. At the same time, the correlation between the expression of SNHG18 and SEMA5A was also analyzed. RESULTS: The analysis confirmed that SNHG18 and its possible target gene SEMA5A were both highly expressed in newly diagnosed MM patients. After analyzing the clinical significance of SNHG18 and SEMA5A in MM patients, we found that the expression of SNHG18 and SEMA5A was related to the Durie-Salmon (DS), International Staging System (ISS), and Revised International Staging System (R-ISS) classification systems, and the Mayo Clinic Risk Stratification for Multiple Myeloma (mSMART; p < 0.05). Moreover, we observed a significant difference in OS between the SNHG18/SEMA5A high expression group and the low expression group. We found a positive correlation between SNHG18 and SEMA5A expression (r = 0.709, p < 0.01). Surprisingly, the expected median OS times of both the SNHG18 and SEMA5Ahigh expression groups were significantly decreased, which was in contrast to those of both the SNHG18 and SEMA5Alow expression groups and the single-gene high expression group (p < 0.05). CONCLUSION: High expression of both SNHG18 and SEMA5A is associated with poor prognosis in patients with MM.

[Hepatitis B virus X protein inhibits hepatoma cell growth in vitro through p14(ARF)-dependent and p14(ARF)-independent pathways].

OBJECTIVE: To explore the effects of hepatitis B virus X protein (HBx) on hepatoma cell growth through p14(ARF)-dependent and p14(ARF)-independent pathways. METHODS: HBx and p14(ARF) were transfected either separately or in combination into HepG2 cells containing wt-p53 but not expressing p14(ARF). The cells were divided into 4 groups, namely pcDNA3 (control), pcDNA3HBx, pcDNA3p14(ARF), and pcDNA3HBx + pcDNA3p14(ARF) groups. Flow cytometry was used to examine the apoptosis rates and cell cycle progression of HepG2 cells in different groups. The expression of p14(ARF), MDM2, p53, and p21(WAF1) proteins were investigated by detecting the activity of p21(WAF1) promoter-luciferase and using Western blotting. RESULTS: The apoptosis rates of HepG2 cells in pcDNA3HBx and pcDNA3p14(ARF) groups were significantly higher than that in the control group (14.11%, 13.72% vs 10.66%). Compared with the control group, pcDNA3HBx and pcDNA3p14(ARF) groups also showed significantly higher cell percentages arrested at G(0)/G(1) phase (63.62%, 61.75% vs 57.42%), luciferase activity of p21 promoter (1.25-/+0.05, 1.09-/+0.06 vs 0.77-/+0.03) and expressions of p53 and p21(WAF1). The cell apoptosis rate, percentage of cells in G(0)/G(1) phase and expression level of p14(ARF) were even higher in pcDNA3HBx+pcDNA3p14(ARF) group (18.61%, 66.74%, and 3.53-/+0.43, respectively) than in either p14(ARF) or HBx group. CONCLUSION: HBx induces p53 expression through p14(ARF)-dependent and independent pathways to activate p21(WAF1) promoter, leading to G(0)/G(1) arrest and apoptosis of HepG2 cells.

Effects of hepatitis B virus on p53 expression in hepatoma cell line SMMU-7721.

AIM: To investigate the contribution of HBV in the development of hepatocarcinoma by examining the effects of HBV on p53 function in SMMU-7721 cell line. METHODS: Plasmid pCMVp53 was transfected or cotransfected with pCMVHBVa (wild-type HBV) or PCMVHBVb (mutation type HBV) into the hepatoma cell line SMMU-7721 by lipofectamine. Apoptosis cells were labeled with annexin V-FITC and confirmed by flow cytometry. Reporter plasmid PG13-CAT or p21-luc was cotransfected, respectively, into each group to determine the transactivation activity of p53 and its effect on p21 promoter. Western blot was performed to observe p53 expression in hepatoma cell line of each group. RESULTS: The group transfected with pCMVp53 alone exhibited higher luciferase activity and higher apoptosis rate, otherwise, the p53 expression and reporter activity of PG13-CAT or P21-luc as well as cell apoptosis rate were obviously higher in the group cotransfected of pCMVp53 with pCMVHBVa, but not in the other cotransfected group. CONCLUSION: Transient transfection of HBV into the SMMU-7721 cell line can enhance p53 expression and its effects on development of hepatocarcinoma.