Upregulation of CCNB2 and a novel lncRNAs-related risk model predict prognosis in clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is the main type of renal cell carcinoma. Cyclin B2 (CCNB2) is a subtype of B-type cyclin that is associated with the prognosis of several cancers. This study aimed to identify the relationship between CCNB2 and progression of ccRCC and construct a novel lncRNAs-related model to predict prognosis of ccRCC patients.

METHODS

The data were obtained from public databases. We identified CCNB2 in ccRCC using Kaplan-Meier survival analysis, univariate and multivariate Cox regression, and Gene Ontology analysis. External validation was then performed. The risk model was constructed based on prognostic lncRNAs by the LASSO algorithm and multivariate Cox regression. Receiver operating characteristics (ROC) curves were used to evaluate the model. Consensus clustering analysis was performed to re-stratify the patients. Finally, we analyzed the tumor-immune microenvironment and performed screening of potential drugs.

RESULTS

CCNB2 associated with late clinicopathological parameters and poor prognosis in ccRCC and was an independent predictor for disease-free survival. In addition, CCNB2 shared the same expression pattern with known suppressive immune checkpoints. A risk model dependent on the expression of three prognostic CCNB2-related lncRNAs (SNHG17, VPS9D1-AS1, and ZMIZ1-AS1) was constructed. The risk signature was an independent predictor of ccRCC. The area under the ROC (AUC) curve for overall survival at 1-, 3-, 5-, and 8-year was 0.704, 0.702, 0.741, and 0.763. The high-risk group and cluster 2 had stronger immunogenicity and were more sensitive to immunotherapy.

CONCLUSION

CCNB2 could be an important biomarker for predicting prognosis in ccRCC patients. Furthermore, we developed a novel lncRNAs-related risk model and identified two CCNB2-related molecular clusters. The risk model performed well in predicting overall survival and immunological microenvironment of ccRCC.

Cyclin B2 impairs the p53 signaling in nasopharyngeal carcinoma

BACKGROUND

Cyclin B2 (CCNB2), a member of the cyclin family, is an oncogene in multiple cancers, including nasopharyngeal carcinoma (NPC). However, the epigenetics mechanism for CCNB2 overexpression in NPC remains unclear. This study dissects the regulatory role of CCNB2 in NPC and the molecular mechanism.

METHODS

Differentially methylated genes (DMG) and differentially expressed genes (DEG) were screened out in GSE52068 and GSE13597 databases, respectively, and candidate targets were identified by the Venn diagram. GO annotation and pathway enrichment analyses were performed on selected DMG and DEG, and a PPI network was constructed to pinpoint hub genes. PCR and qMSP were conducted to detect the expression and methylation of CCNB2 in cells. The siRNA targeting CCNB2 was transfected into NPC cells, and the migration, proliferation, cell cycle, epithelial-mesenchymal transition (EMT), tumorigenesis, and metastasis were examined. The upstream factor responsible for CCNB2 overexpression in NPC was explored. The p53 activity in NPC cells was assessed using western blot analysis.

RESULTS

CCNB2 showed hypomethylation and overexpression in NPC. CCNB2 silencing inhibited cell migration, proliferation, cell cycle entry, and EMT. JMJD6 was overexpressed in NPC and upregulated CCNB2 through demethylation. JMJD6 reversed the effects of CCNB2 downregulation, resulting in elevated cellular activity in vitro and tumorigenic and metastatic activities in vivo. CCNB2 blocked the p53 pathway, while the p53 pathway inhibitor reversed the effect of CCNB2 silencing to increase the activity of NPC cells.

CONCLUSIONS

JMJD6 enhanced CCNB2 transcription by demethylating CCNB2, thereby repressing the p53 pathway and promoting NPC progression.

Cyclin B2 overexpression promotes tumour growth by regulating jagged 1 in hepatocellular carcinoma

Background: Our previous study showed that Cyclin B2 (CCNB2) is closely related to the occurrence and progression of hepatocellular carcinoma (HCC).

Aim of the study: This study aimed to clarify the effect of CCNB2 gene silencing on tumorigenesis in nude mice and to detect the potential mechanism.

Methods: The effect of CCNB2 on HCC was tested in vivo. The downstream target genes of CCNB2 were predicted by proteomics and confirmed by western blot assay. The regulatory functions of CCNB2 in the proliferation and migration of HCC cells were determined through functional recovery experiments. The expression of the downstream target genes of CCNB2 was detected by immunohistochemistry.

Results: Knockdown of CCNB2 decreased tumour formation rate and tumour volume and weight and inhibited tumour proliferation. A total of 130 differentially expressed proteins were detected by proteomics, and Jagged 1 (JAG1) was predicted as the potential downstream target of CCNB2. Western blot assay revealed that CCNB2 and JAG1 expression was significantly correlated in HCC cells. The results of functional recovery experiments suggested that CCNB2 knockdown weakened the proliferation and migration ability of HCC cells, while JAG1 overexpression restored this ability of HCC cells that was weakened by CCNB2 knockdown. Immunohistochemistry showed that JAG1 expression was higher in HCC tissues than in paracancerous tissues and was related to tumour size and number and tumour thrombus formation.

Conclusions: The proliferation of HCC cells in vivo was inhibited by CCNB2 knockdown. CCNB2 may accelerate the proliferation and metastasis of HCC cells by increasing JAG1 expression.

Upregulation of Cyclin B2 (CCNB2) in breast cancer contributes to the development of lymphovascular invasion

Lymphovascular invasion (LVI) is a key step in breast cancer (BC) metastasis. Targeting the molecular drivers of LVI can improve BC patients' management. However, the underlying molecular mechanisms of LVI are complex and interconnected with various carcinogenesis pathways. This study aimed to identify the key regulatory gene associated with LVI and to investigate its mechanisms of action and prognostic significance. Artificial neural network (ANN) was applied to two large transcriptomic datasets of BC with well-characterised LVI status. Cyclin B2 (CCNB2) was identified in the top genes associated with LVI positivity. In vitro functional assays were carried out to assess the role of CCNB2 in tumour cell behaviour and their interactions with endothelial cells using a panel of BC cell lines. Large annotated BC cohorts were used to assess the clinical and prognostic role of CCNB2 at the transcriptomic and protein levels. Knockdown (KD) of CCNB2 mRNA reduced BC cell migration, inhibited proliferation, blocked the G2/M transition during the cell cycle and increased the number of apoptotic cells. Importantly, KD of CCNB2 reduced BC cell lines adherence and transmigration across endothelial cell lines. High CCNB2 protein expression was independently associated with LVI positivity in addition to other features of aggressive behaviour, including larger tumour size, higher histological grade, hormonal receptor-negativity, and HER2-positivity, and with shorter survival. We conclude that CCNB2 plays a crucial role in LVI development in BC, implying that CCNB2 could confer a promising therapeutic target to inhibit LVI and reduce metastatic events.

Prognostic Significance of CCNB2 Expression in Triple-Negative Breast Cancer

Purpose

The aim of this study was to explore potential gene therapy targets for triple-negative breast cancer (TNBC).

Patients and Methods

Three gene expression profiles (GSE64790, GSE62931, and GSE38959) from the Gene Expression Omnibus (GEO) database were analyzed. The GEO2R analysis tool was used to screen for differentially expressed genes (DEGs) between TNBC and normal tissues, followed by Gene Ontology functional annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of the DEGs. The protein–protein interaction network of DEGs was visualized using Metascape to identify the core genes. Subsequently, transcriptional data for the core genes in patients with breast cancer were investigated in the ONCOMINE database. Kaplan–Meier survival analysis was used to evaluate the prognostic value of core gene expression levels in patients with TNBC. Finally, the clinicopathological and long-term follow-up data of 39 patients with TNBC were retrospectively analyzed at the First Affiliated Hospital of the Bengbu Medical College between January 2014 and July 2020. Immunohistochemistry was used to evaluate the expression and subcellular localization of CCNB2 in TNBC tissues.

Results

A total of 66 DEGs were identified between TNBC and normal tissues, including 33 upregulated and 33 downregulated genes in TNBC. Furthermore, a potential protein complex was identified for five core genes. The high expression of these core genes, especially the overexpression of CCNB2, was correlated with a poor prognosis of patients with TNBC. The CCNB2 protein was expressed in the cytoplasm, and its expression was significantly higher in TNBC tissues than that in the adjacent nontumor tissues. Overall survival of patients was significantly correlated with the expression of CCNB2 (p < 0.05).

Conclusion

CCNB2 may play a crucial role in the development of TNBC and has the potential to be used as a prognostic biomarker for TNBC.

Protective role of m6A binding protein YTHDC2 on CCNB2 in manganese-induced spermatogenesis dysfunction

Human infertility has become the third largest serious disease in the world, seriously affecting the quality of human fertility. Studies have shown that manganese (Mn) can accumulate in the testis through the blood-testicular barrier and damage the male reproductive system. However, the mechanism has not been explored clearly. Recent studies have reported that YTH domain-containing 2 (YTHDC2) can regulate reproductive function. However, none has explored the role of YTHDC2 in Mn-induced reproductive toxicity. The present study investigated whether YTHDC2/CyclinB2 (CCNB2) pathway participates in Mn-induced reproductive toxicity using Kunming mice, spermatogonia, and the seminal plasma of male workers. The mice were received intraperitoneal (i.p.) injections of 0, 12.5, 25, and 50 mg/kg MnCl₂ once daily for 2 weeks. The cells were treated with 0, 100, 200 and 400 μM MnCl₂ for 24 h. Here, we found that occupational Mn exposure significantly increased Mn levels in the seminal plasma of male workers, while decreased sperm density, semen quality, and the levels of YTHDC2, CCNB1, and CCNB2. We found that Mn can inhibit the YTHDC2/CCNB2 signaling pathway and block the G2/M phase of the cell cycle. Moreover, the morphology of cells and the histomorphology of mice testis were injured. Notably, over-expression (OE) of YTHDC2 increased CCNB2 levels, reduced cell cycle arrest, and improved reproductive toxicity after Mn exposure. These findings suggest that the YTHDC2/CCNB2 signaling pathway participates in Mn-induced reproductive toxicity, and OE of YTHDC2 can mitigate the toxicity of Mn.

Identification of potential core genes at single-cell level contributing to pathogenesis of pancreatic ductal adenocarcinoma through bioinformatics analysis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) prognosis has not improved over the last decades because of the lack of effective diagnostic and therapeutic methods in the early stage of the disease.

METHODS

Several gene expression profiles were downloaded from the Expression Omnibus (GEO) database. We calculated the differentially expressed mRNAs (DEGs) and miRNAs (DEmiRs). Then, we constructed a miRNA-mRNA regulatory network by using the miRWalk database. For the DEGs regulated by DEmiRs, we introduced GEPIA to confirm these DEGs' expression and effect on overall survival. We used other GEO datasets and mRNA-miRNA target databases to validate these DEGs and their relationship with DEmiRs. All these potential core DEGs regulated by DEmiRs were also analyzed at the single-cell level to confirm their cell type source.

RESULTS

CCNB2 and KCNN4, which were regulated by several micro RNAs, showed relatively high expression levels in PDAC patients and significant association with worse overall survival. Furthermore, we identified many DEGs at single-cell level and found that 10 oncogenes were significantly upregulated in type 2 ductal cell type, thereby further demonstrating that type 2 ductal cells might be major sources of malignant cells and are valuable therapeutic targets in PDAC.

CONCLUSIONS

Our data added some new insights into the molecular mechanism of PDAC and may be helpful for finding potential biomarkers for diagnosis. These discovery at single-cell level may also be useful for developing new therapeutic targets for PDAC patients.

Hsa_circ_0000285 knockdown inhibits the progression of hepatocellular carcinoma by sponging miR-582-3p to regulate CCNB2 expression

AIM

Hsa_circ_0000285, a novel circular RNA, has been proven to extensively take part in the pathogenesis of numerous tumors. In hepatocellular carcinoma (HCC), very little is known about hsa_circ_0000285 until now. Hence, this research aims to determine hsa_circ_0000285's functional role and underlying mechanisms in HCC.

METHODS

The expressions of miR-582-3p, hsa_circ_000028, and cyclin B2 (CCNB2) among the HCC cells and tumor samples were determined by performing western blotting and qRT-PCR analyses. The impacts of hsa_circ_000028 on the proliferative and migratory abilities of HCC cells were examined through the execution of CCK-8 and wound-healing assays. Meanwhile, the expressions of the proteins Bcl-2 and Bax were detected via western blotting. Tumor xenograft models were established to examine how hsa_circ_000028 functions during the mediation of HCC tumor growth in vivo. RNA immunoprecipitation and luciferase reporter experiments were performed for the validation of the interactions of miR-582-3p, hsa_circ_000028, and CCNB2 with each other.

RESULTS

Elevated hsa_circ_0000285 and CCNB2 expressions, and a decreased miR-582-3p expression were observed among the HCC cell lines and tumors. Hsa_circ_0000285 bound to miR-582-3p competitively to improve CCNB2 levels. Silencing of hsa_circ_0000285 promoted apoptosis and repressed proliferation and migration among HCC cells. Moreover, silencing hsa_circ_0000285 also impeded the growth of HCC tumors in vivo. Inhibiting hsa_circ_0000285 or CCNB2 reversed the miR-582-3p-knockdown-mediated promotion of malignant HCC cell phenotypes.

CONCLUSION

Our study has demonstrated that hsa_circ_0000285 fosters the development of malignant HCC cells phenotypes through the modulation of the miR-582-3p/CCNB2 axis. Thus, these results suggest that hsa_circ_0000285 is a prospective target for HCC treatment.

CCNB2 is a novel prognostic factor and a potential therapeutic target in Low-grade glioma (LGG)

Background: Cyclin B2 (CCNB2) is an important component of the cyclin pathway and plays a key role in the occurrence and development of cancer. However, the correlation between prognosis of low-grade glioma (LGG), CCNB2, and tumor infiltrating lymphocytes is not clear. Methods: The expression of CCNB2 in LGG was queried in Gene Expression Profiling Interactive Analysis 2 (GEPIA2) and TIMER databases. The relationships between CCNB2 and the clinicopathological features of LGG were analyzed using the Chinese Glioma Genome Atlas (CGGA) database. The relationship between CCNB2 expression and overall survival (OS) was evaluated by GEPIA2. The correlation between CCNB2 and LGG immune infiltration was analyzed by the TIMER database. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect CCNB2 expression. Results: The expression of CCNB2 differed across different tumor tissues, but was higher in LGG than in normal tissues. LGG patients with high expression of CCNB2 have poorer prognosis. The expression of CCNB2 was correlated with age, WHO grade, IDH mutational status, 1p/19q codeletion status, and other clinicopathological features. The expression of CCNB2 in LGG was positively correlated with the infiltration level of B cells, dendritic cells, and macrophages. qRT-PCR results revealed that the expression of CCNB2 in LGG tissues was higher than normal tissues and higher expression of CCNB2 was associated with worse prognosis. Conclusion: CCNB2 may be used as a potential biomarker to determine the prognosis of LGG and is also related to immune infiltration.

Bioinformatics prediction and experimental verification identify MAD2L1 and CCNB2 as diagnostic biomarkers of rhabdomyosarcoma

Background

Rhabdomyosarcoma (RMS) is a malignant soft-tissue tumour. In recent years, the tumour microenvironment (TME) has been reported to be associated with the development of tumours. However, the relationship between the occurrence and development of RMS and TME is unclear. The purpose of this study is to identify potential tumor microenvironment-related biomarkers in rhabdomyosarcoma and analyze their molecular mechanisms, diagnostic and prognostic significance.

Methods

We first applied bioinformatics method to analyse the tumour samples of 125 patients with rhabdomyosarcoma (RMS) from the Gene Expression Omnibus database (GEO). Differential genes (DEGs) that significantly correlate with TME and the clinical staging of tumors were extracted. Immunohistochemistry (IHC) was applied to validate the expression of mitotic arrest deficient 2 like 1 (MAD2L1) and cyclin B2 (CCNB2) in RMS tissue. Then, we used cell function and molecular biology techniques to study the influence of MAD2L1 and CCNB2 expression levels on the progression of RMS.

Results

Bioinformatics results show that the RMS TME key genes were screened, and a TME-related tumour clinical staging model was constructed. The top 10 hub genes were screened through the establishment of a protein–protein interaction (PPI) network, and then Gene Expression Profiling Interactive Analysis (GEPIA) was conducted to measure the overall survival (OS) of the 10 hub genes in the sarcoma cases in The Cancer Genome Atlas (TCGA). Six DEGs of statistical significance were acquired. The relationship between these six differential genes and the clinical stage of RMS was analysed. Further analysis revealed that the OS of RMS patients with high expression of MAD2L1 and CCNB2 was worse and the expression of MAD2L1 and CCNB2 was related to the clinical stage of RMS patients. Gene set enrichment analysis (GSEA) revealed that the genes in MAD2L1 and CCNB2 groups with high expression were mainly related to the mechanism of tumour metastasis and recurrence. In the low-expression MAD2L1 and CCNB2 groups, the genes were enriched in the metabolic and immune pathways. Immunohistochemical results also confirmed that the expression levels of MAD2L1 (30/33, 87.5%) and CCNB2 (33/33, 100%) were remarkably higher in RMS group than in normal control group (0/11, 0%). Moreover, the expression of CCNB2 was related to tumour size. Downregulation of MAD2L1 and CCNB2 suppressed the growth, invasion, migration, and cell cycling of RMS cells and promoted their apoptosis. The CIBERSORT immune cell fraction analysis indicated that the expression levels of MAD2L1 and CCNB2 affected the immune status in the TME.

Conclusions

The expression levels of MAD2L1 and CCNB2 are potential indicators of TME status changes in RMS, which may help guide the prognosis of patients with RMS and the clinical staging of tumours.

Transcriptomic analysis of tumor tissues and organoids reveals the crucial genes regulating the proliferation of lung adenocarcinoma

Background

Accumulative evidence shows that an organoid is a more practical and reliable tool in cancer biology research. This study aimed to identify and validate crucial genes involved in non-small cell lung cancer carcinogenesis and development using the transcriptomic analysis of tumor tissues and organoids.

Methods

Gene set enrichment analysis (GSEA) of tumor tissues, tumor organoids, and normal tissues was performed to reveal the similar and different mechanisms involved in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) carcinogenesis and progression. Differentially expressed gene analysis, prognostic analysis, and gene co-expression network analysis were further used to identify hub genes involved in LUAD and LUSC carcinogenesis and development. Finally, LUAD cell lines and organoids were used to validate these findings.

Results

GSEA analysis was performed to reveal the similar mechanisms involved in LUAD and LUSC carcinogenesis and development, such as P53 signaling pathway, base mismatch repair, DNA replication, cAMP signaling pathway and PPAR pathway. However, comparing with LUSC organoids, LUAD organoids showed downregulation of immune-related pathways, inflammation-related pathways, MAPK signaling pathways, and Rap1 signaling pathways, although these pathways were downregulated in LUAD and LUSC tissues by comparing with normal lung tissues. Further gene co-expression network analysis and prognostic analysis indicated CDK1, CCNB2, and CDC25A as the hub tumor-promoting genes in LUAD but not in LUSC, which were further validated in other datasets. Using LUAD cell lines and organoid models, CDK1 and CCNB2 knockdown were found to suppress LUAD proliferation. However, CDC25A knockdown did not inhibit LUAD cell line proliferation but could effectively suppress LUAD organoid growth, indicating that an organoid could be used as an effective tool to study cancer biology in LUAD.

Conclusions

The results revealed CDK1, CCNB2, and CDC25A as the hub genes involved in LUAD carcinogenesis and development, which could be used as the potential biomarkers and targets for LUAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03043-6.

CCNB2/SASP/Cathepsin B & PGE2 Axis Induce Cell Senescence Mediated Malignant Transformation

Glioma is the most frequent and aggressive adult brain tumor with maximum mortality. However, the gene alteration and mechanism underlying malignant transformation of glioma remain largely unknown. We aimed to find key factors regulating tumor progression and malignant transformation of glioma. Here we compared the gene expression profiles of 693 glioma patients by HGG vs. LGG model, and identified a key factor CCNB2 for malignant transformation in glioma. CCNB2 induced a senescence-associated secretory phenotype (SASP) of glioma cells, and the malignant progression, such as invasion and excessive proliferation was mediated by secreting SASP cytokines, Cathepsin B and PGE2. These findings demonstrated a previously undiscovered link between senescence, CCNB2/SASP/Cathepsin B & PGE2 axis and malignant transformation in glioma. This might provide novel insights on developing new therapeutic regimens for abrogating aggressiveness of glioma.

Gene regulation network analysis reveals core genes associated with survival in glioblastoma multiforme

Glioblastoma multiforme (GBM) is a very serious mortality of central nervous system cancer. The microarray data from GSE2223, GSE4058, GSE4290, GSE13276, GSE68848 and GSE70231 (389 GBM tumour and 67 normal tissues) and the RNA-seq data from TCGA-GBM dataset (169 GBM and five normal samples) were chosen to find differentially expressed genes (DEGs). RRA (Robust rank aggregation) method was used to integrate seven datasets and calculate 133 DEGs (82 up-regulated and 51 down-regulated genes). Subsequently, through the PPI (protein-protein interaction) network and MCODE/ cytoHubba methods, we finally filtered out ten hub genes, including FOXM1, CDK4, TOP2A, RRM2, MYBL2, MCM2, CDC20, CCNB2, MYC and EZH2, from the whole network. Functional enrichment analyses of DEGs were conducted to show that these hub genes were enriched in various cancer-related functions and pathways significantly. We also selected CCNB2, CDC20 and MYBL2 as core biomarkers, and further validated them in CGGA, HPA and CCLE database, suggesting that these three core hub genes may be involved in the origin of GBM. All these potential biomarkers for GBM might be helpful for illustrating the important role of molecular mechanisms of tumorigenesis in the diagnosis, prognosis and targeted therapy of GBM cancer.

miR-335-5p Regulates Cell Cycle and Metastasis in Lung Adenocarcinoma by Targeting CCNB2

Background

Lots of studies have shown that cyclin disorders can promote tumor development. This study aims to investigate the biological function and molecular mechanism of CCNB2 in lung adenocarcinoma (LUAD).

Methods

LUAD data were downloaded from GEO database and TCGA-LUAD database. Differential analysis was conducted to find the differentially expressed miRNAs and mRNAs, while targeted prediction was done for the access of potential target mRNAs. Gene expression level was detected by qRT-PCR and Western blot in human LUAD cell lines A-427, A549, Calu-3, PC-9 and human bronchial epithelial cell line BEAS-2B. MTT, colony formation, Transwell and flow cytometry assays were used to detect cell proliferation, metastasis, and cell cycle changes of PC-9 cell line. The dual-luciferase reporter gene was used to detect the targeted binding relationship of the target miRNA and mRNA.

Results

CCNB2 was highly expressed and served as a biomarker indicating poor prognosis in LUAD patients. Cell function experiments confirmed the inhibitory effects of silencing CCNB2 on the proliferation, migration and invasion of LUAD cells and cell cycle was blocked in the G0/G1 phase. In addition, with regard to the regulatory mechanism, we demonstrated that miR-335-5p had binding sites with 3ʹ-UTR of CCNB2, indicating that miR-335-5p could target the regulation expression of CCNB2. In subsequent cell function tests, overexpression of miR-335-5p inhibited the proliferation and metastasis of cancer cells, and the rescue experiments also verified that miR-335-5p could reverse the promotion of CCNB2 overexpression on the progress of cancer cells.

Conclusion

In summary, our results revealed that miR-335-5p could target the down-regulation of CCNB2 to inhibit the occurrence and development of LUAD.

Estrogen-regulated PTTG1 promotes breast cancer progression by regulating cyclin kinase expression

BACKGROUND

The present study aims to investigate the effects of pituitary tumor transforming gene (PTTG) 1 on breast cancer and its underlying mechanism.

METHODS

GEO data set was applied to analyze the relationship between PTTG1 and survival status and the TCGA breast cancer dataset was used to explore its possible targets. The stable cell lines including PTTG1 knockdown cells, estrogen receptor (ESR) 1 knockdown cells, and PTTG1 overexpression cells were constructed. MTT was used to determine cell viabilities. Propidium iodide (PI) staining and flow cytometry were used to analyze the cell cycle. Quantitative polymerase chain reaction (qPCR) was employed to determine the mRNA expressions. Points mutations and luciferase reporter assays were used to determine the binding sites of estrogen.

RESULTS

PTTG1 was associated with poor survival rates in breast cancer. In vitro study demonstrated that PTTG1 affected cell viabilities of MCF7 and T47D cells. Besides, PTTG1 affected cell cycle arrest of breast cancer cells. Overexpression of PTTG1 led to more breast cancer cells distributed in S phase. The levels of PTTG1 were associated with estrogen and further results showed that the levels of PTTG1 were positively correlated to tamoxifen resistance. Two genes including CCNA2 and CCNB2 were identified to be possible targets of PTTG1.

CONCLUSION

Estrogen-regulated PTTG1 promotes the development of breast cancer cells by the regulation of the cell cycle.

Roles of CCNB2 and NKX3-1 in Nasopharyngeal Carcinoma

Background: Nasopharyngeal carcinoma (NPC) is leading form of cancer occurring in a few well-defined regions, including southern China. NPC possess a unique and intricate etiology that remains to be elucidated. Herein, we determine expression patterns of CCNB2 and NKX3-1 and identify their roles in NPC. Materials and Methods: Gene-expression profiles of NPC in the Gene Expression Omnibus (GEO) were analyzed. Cell viability, invasion, apoptosis, cell cycle entry and mitochondrial membrane potential (MMP) were evaluated in the presence of NKX3-1 or in the absence of CCNB2. Results: In all, 187 upregulated genes and 683 downregulated genes were obtained by analyzing GSE13597. NKX3-1, the downregulated gene, and CCNB2, the upregulated one, were further confirmed by in vitro studies. Overexpression of NKX3-1 was shown to inhibit NPC cell viability and invasion. Knockdown of CCNB2 was demonstrated to reduce cell cycle entry and MMP but induce apoptosis in NPC cells. Conclusions: Taken together, the key finding obtained from the study supports CCNB2 and NKX3-1 as two promising therapeutic candidates for NPC. Molecular mechanisms that control CCNB2 or NKX3-1 disturbance require further investigation and clarification.

Effect of miR-205 on proliferation and migration of thyroid cancer cells by targeting CCNB2 and the mechanism

This study explored the target of miR-205 and the effect of miR-205 on the proliferation and migration regulating its target in thyroid cancer cells (TC). Twenty-five pairs of TC and adjacent tissues were collected after surgical resection. Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expression of miR-205 in TC tissues and cells (SW579, B-CPAP, TPC-1, WRO). SW579 cells were transfected with miR-205 mimic, and SW579 cells with overexpression of miR-205 were constructed. The effects of miR-205 overexpression on the proliferation and migration of SW579 cells were observed by cell counting kit-8 (CCK-8) and Transwell assays, respectively. Luciferase reporter assay was further used to look for the target of miR-205 and to study the mechanism of miR-205 in the proliferation and migration of TC cells. Compared with normal tissues and cells, the expression of miR-205 was significantly reduced in TC tissues (t=3.47, P=0.031) and cells (t=5.41, P=0.016). Overexpression of miR-205 inhibited the proliferation (t=4.12, P=0.035) and migration (t=4.47, P=0.027) of SW579 cells. Luciferase reporter assays found that CCNB2 was a target gene of miR-205 (t=4.63, P=0.024), qRT-PCR and western blot assays confirmed there was negatively correlation between CCNB2 and miR-205 (t=3.55, P=0.029; t=2.86, P=0.043). CCNB2 overexpression reversed the inhibition of miR-205 on the proliferation (t=3.70, P=0.031) and migration (t=4.12, P=0.022) of SW579 cells. In conclusion, miR-205 inhibits the proliferation and migration of TC cells by targeting CCNB2, which may be a potential target of TC therapy.

Potential Prognostic Predictors and Molecular Targets for Skin Melanoma Screened by Weighted Gene Co-expression Network Analysis

AIMS AND OBJECTIVES

Among skin cancers, malignant skin melanoma is the leading cause of death. Identification of gene markers of malignant skin melanoma associated with survival may provide new clues for prognosis prediction and treatment. This research aimed to screen out potential prognostic predictors and molecular targets for malignant skin melanoma.

INTRODUCTION

Information regarding gene expression in skin melanoma and patients' clinical traits was obtained from the Gene Expression Omnibus database. Weighted gene co-expression network analysis (WGCNA) was applied to build co-expression modules and investigate the association between the modules and clinical traits. Moreover, functional enrichment analysis was performed for clinically significant co-expression modules. Hub genes of these modules were validated via Gene Expression Profiling Interactive Analysis (GEPIA) and the Human Protein Atlas (http:// www.proteinatlas.org).

METHODS

First, using WGCNA, 9 co-expression modules were constructed by the top 25% differentially expressed genes (4406 genes) from 77 human melanoma samples. Two co-expression modules (magenta and blue modules) were significantly correlated with survival months (r = -0.27, p = 0.02; r = 0.27, p = 0.02, respectively). The results of functional enrichment analysis demonstrated that the magenta module was mainly enriched in the cell cycle process and the blue module was mainly enriched in the immune response process. Additionally, the GEPIA and Human Protein Atlas results suggested that the hub genes CCNB2, ARHGAP30, and SEMA4D were associated with relapse-free survival and overall survival (all p-values < 0.05) and were differentially expressed in melanoma tumors and normal skin.

RESULTS AND CONCLUSION

The results provided the framework of co-expression gene modules of skin melanoma and screened out CCNB2, ARHGAP30, and SEMA4D associated with survival as potential prognostic predictors and molecular targets of treatment.

MicroRNA-582-3p negatively regulates cell proliferation and cell cycle progression in acute myeloid leukemia by targeting cyclin B2

Background

MicroRNAs (miRNAs) function as post-transcriptional gene expression regulators. Some miRNAs, including the recently discovered miR-582–3p, have been implicated in leukemogenesis. This study aimed to reveal the biological function of miR-582–3p in acute myeloid leukemia (AML), which is one of the most frequently diagnosed hematological malignancies.

Methods

The expression of miR-582–3p was determined using quantitative real-time PCR in blood samples from leukemia patients and in cell lines. Cell proliferation and cell cycle distribution were analyzed using the CCK-8, colony formation and flow cytometry assays. The target gene of miR-582–3p was verified using a dual-luciferase reporter assay. The G2/M phase arrest-related molecule contents were measured using western blotting analysis.

Results

We found miR-582–3p was significantly downregulated in the blood samples from leukemia patients and in the cell lines. MiR-582–3p overexpression significantly impaired cell proliferation and induced G2/M cell cycle arrest in THP-1 cells. Furthermore, cyclin B2 (CCNB2) was confirmed as a target gene of miR-582–3p and found to be negatively regulated by miR-582–3p overexpression. More importantly, CCNB2 knockdown showed suppressive effects on cell proliferation and cell cycle progression similar to those caused by miR-582–3p overexpression. The inhibitory effects of miR-582–3p overexpression on cell proliferation and cell cycle progression were abrogated by CCNB2 transfection.

Conclusion

These findings indicate new functions and mechanisms for miR-582–3p in AML development. Further study could clarify if miR-582–3p and CCNB2 are potential therapeutic targets for the treatment of AML.

CCNB2 overexpression is a poor prognostic biomarker in Chinese NSCLC patients

Cyclin B2 (CCNB2), a member of cyclin family proteins, serves a key role in progression of G2/M transition. The clinical value of CCNB2 in non-small cell lung cancer is still unknown. The aim of our study is to identify the role of CCNB2 in NSCLC patients. The status of CCNB2 in NSCLC tissues and normal lung tissues was observed in Gene Expression Omnibus (GEO: GSE19804). CCNB2 mRNA and protein expressions were detected in NSCLC and normal lung tissues by using Real-time PCR and immunohistochemistry. The association of CCNB protein expression with clinical characteristics of 186 NSCLC patients was analyzed by immunohistochemistry. Based on microarray data (GEO: GSE19804), we observed that CCNB2 was significantly overexpressed in NSCLC tissues compared with paired adjacent normal lung tissue. Furthermore, we verified mRNA and protein levels of CCNB2 expression were both increased in NSCLC tissues. We found high levels of CCNB2 protein were positively associated with the status of differentiated degree, tumor size, lymph node metastasis, distant metastasis, and clinical stage. Meanwhile, CCNB2 protein overexpression was an independent unfavorable prognostic factor for the overall survival of patients with NSCLC. In conclusion, overexpression of CCNB2 protein is associated with clinical progression and poor prognosis in NSCLC.

High-resolution molecular validation of self-renewal and spontaneous differentiation in clinical-grade adipose-tissue derived human mesenchymal stem cells

Improving the effectiveness of adipose-tissue derived human mesenchymal stromal/stem cells (AMSCs) for skeletal therapies requires a detailed characterization of mechanisms supporting cell proliferation and multi-potency. We investigated the molecular phenotype of AMSCs that were either actively proliferating in platelet lysate or in a basal non-proliferative state. Flow cytometry combined with high-throughput RNA sequencing (RNASeq) and RT-qPCR analyses validate that AMSCs express classic mesenchymal cell surface markers (e.g., CD44, CD73/NT5E, CD90/THY1, and CD105/ENG). Expression of CD90 is selectively elevated at confluence. Self-renewing AMSCs express a standard cell cycle program that successively mediates DNA replication, chromatin packaging, cyto-architectural enlargement, and mitotic division. Confluent AMSCs preferentially express genes involved in extracellular matrix (ECM) formation and cellular communication. For example, cell cycle-related biomarkers (e.g., cyclins E2 and B2, transcription factor E2F1) and histone-related genes (e.g., H4, HINFP, NPAT) are elevated in proliferating AMSCs, while ECM genes are strongly upregulated (>10-fold) in quiescent AMSCs. AMSCs also express pluripotency genes (e.g., POU5F1, NANOG, KLF4) and early mesenchymal markers (e.g., NES, ACTA2) consistent with their multipotent phenotype. Strikingly, AMSCs modulate expression of WNT signaling components and switch production of WNT ligands (from WNT5A/WNT5B/WNT7B to WNT2/WNT2B), while upregulating WNT-related genes (WISP2, SFRP2, and SFRP4). Furthermore, post-proliferative AMSCs spontaneously express fibroblastic, osteogenic, chondrogenic, and adipogenic biomarkers when maintained in confluent cultures. Our findings validate the biological properties of self-renewing and multi-potent AMSCs by providing high-resolution quality control data that support their clinical versatility.