BUB1 predicts poor prognosis and immune status in liver hepatocellular carcinoma

Expression of the checkpoint kinase BUB1 is a predictor of response to cancer therapies

The identification of clinically-relevant biomarkers is of upmost importance for the management of cancer, from diagnosis to treatment choices. We performed a pan-cancer analysis of the mitotic checkpoint budding uninhibited by benzimidazole 1 gene BUB1, in the attempt to ascertain its diagnostic and prognostic values, specifically in the context of drug response. BUB1 was found to be overexpressed in the majority of cancers, and particularly elevated in clinically aggressive molecular subtypes. Its expression was correlated with clinico-phenotypic features, notably tumour staging, size, invasion, hypoxia, and stemness. In terms of prognostic value, the expression of BUB1 bore differential clinical outcomes depending on the treatment administered in TCGA cancer cohorts, suggesting sensitivity or resistance, depending on the expression levels. We also integrated in vitro drug sensitivity data from public projects based on correlation between drug efficacy and BUB1 expression to produce a list of candidate compounds with differential responses according to BUB1 levels. Gene Ontology enrichment analyses revealed that BUB1 overexpression in cancer is associated with biological processes related to mitosis and chromosome segregation machinery, reflecting the mechanisms of action of drugs with a differential effect based on BUB1 expression.

A robust six-gene prognostic signature based on two prognostic subtypes constructed by chromatin regulators is correlated with immunological features and therapeutic response in lung adenocarcinoma

Accumulating evidence has demonstrated that chromatin regulators (CRs) regulate immune cell infiltration and are correlated with prognoses of patients in some cancers. However, the immunological and prognostic roles of CRs in lung adenocarcinoma (LUAD) are still unclear. Here, we systematically revealed the correlations of CRs with immunological features and the survival in LUAD patients based on a cohort of gene expression datasets from the public TCGA and GEO databases and real RNA-seq data by an integrative analysis using a comprehensive bioinformatics method. Totals of 160 differentially expressed CRs (DECRs) were identified between LUAD and normal lung tissues, and two molecular prognostic subtypes (MPSs) were constructed and evaluated based on 27 prognostic DECRs using five independent datasets (p =0.016, <0.0001, =0.008, =0.00038 and =0.00055, respectively). Six differentially expressed genes (DEGs) (CENPK, ANGPTL4, CCL20, CPS1, GJB3, TPSB2) between two MPSs had the most important prognostic feature and a six-gene prognostic model was established. LUAD patients in the low-risk subgroup showed a higher overall survival (OS) rate than those in the high-risk subgroup in nine independent datasets (p <0.0001, =0.021, =0.016, =0.0099, <0.0001, =0.0045, <0.0001, =0.0038 and =0.00013, respectively). Six-gene prognostic signature had the highest concordance index of 0.673 compared with 19 reported prognostic signatures. The risk score was significantly correlated with immunological features and activities of oncogenic signaling pathways. LUAD patients in the low-risk subgroup benefited more from immunotherapy and were less sensitive to conventional chemotherapy agents. This study provides novel insights into the prognostic and immunological roles of CRs in LUAD.

Knockdown of BUB1 inhibits tumor necrosis factor-α-induced proliferation and migration of rheumatoid arthritis synovial fibroblasts by regulating PI3K/Akt pathway

BACKGROUND

Rheumatoid arthritis (RA) is a common disease with joint cartilage destruction. BUB1 Mitotic Checkpoint Serine/Threonine Kinase (BUB1) is abnormally expressed in synovial tissues of RA patients, but its effect on RA remains unclear. In this study, we explored the role of BUB1 in RA.

METHODS

An RA cell model was constructed by treating MH7A cells with tumor necrosis factor-α (TNF-α). The levels of BUB1, GAPDH, phosphorylated phosphatidylinositol 3 kinase (p-PI3K)/PI3K, and phosphorylated serine/threonine kinase (p-Akt)/Akt in MH7A cells were examined by Western blot. The MH7A cell proliferation was examined by colony formation assay. Wound healing assay and transwell assay were carried out to detect MH7A cell migration and invasion. The mRNA levels of proinflammatory cytokines were assessed by quantitative reverse transcription polymerase chain reaction.

RESULTS

The results showed that knockdown BUB1 inhibited TNF-α-induced MH7A cell proliferation, migration, and invasion. Silencing BUB1 repressed the PI3K/Akt pathway in TNF-α-induced MH7A cells. We also found that the TNF-α-induced MH7A cell proliferation, migration, and invasion were repressed by si-BUB1 transfection, whereas these effects were attenuated by 740Y-P (an activator of the PI3K pathway) co-treatment. Knockdown of BUB1 reduced the expression of the proinflammatory cytokines.

CONCLUSION

Knockdown BUB1 repressed TNF-α-induced MH7A cell proliferation, migration and invasion through the PI3K/Akt pathway.

Comprehensive analysis of BUBs gene family in lung adenocarcinoma with immunological analysis

Lung adenocarcinoma (LUAD) is one of the most commonly malignant tumors, and major challenges remain in the treatment of LUAD. Budding uninhibited by benzimidazole 1/3 (BUB1/3) play significant roles in the process of spindle-assembly checkpoint (SAC) during mitosis. However, their roles in LUAD have not been established. Here, we performed an immunological analysis of BUB1/3 in LUAD using a comprehensive bioinformatics approach, quantitative real-time-PCR and Western blotting technique. Our results indicated that the expression levels of BUB1 and BUB3 in LUAD samples were higher than the expression levels in the control groups and were associated with some clinicopathologic parameters in patients with LUAD. BUB1/3 and their related genes were enriched in cell immune, and the immune infiltration analysis revealed that the BUB1/3 expression profile was significantly correlated with characteristics of immune cell infiltration. Survival analysis showed that the disease-free survival and overall survival of patients with LUAD decreased with an increase in the BUB1/3 expression levels. The mRNA and protein expression levels of BUB1 and BUB3 in each of the LUAD cell lines were upregulated to varying degrees. BUB1 and BUB3 are the potential immunological therapeutic intervention targets for patients with LUAD.

Hypoxia promotes epithelial-mesenchymal transition in lung cancer cells via regulating the NRF2/miR‑27a/BUB1 pathway

PURPOSE

Lung cancer (LC) is the most common malignancy in the world. It is well that hypoxia is common in lung cancer, which contributes to lung cancer progression and metastasis [1]. miRNA-27a as a repressor factor is a lowly expression within non-small cell lung cancer (NSCLC). However, the molecular mechanism between miR-27a and hypoxia in lung cancer progression remains poorly understood. This study aims to explore hypoxia promotes epithelial-mesenchymal transition in lung cancer cells via regulating the NRF2/miR‑27a/BUB1 pathway.

METHODS

We detect the expression of miR-27a after exposure to hypoxia conditions in lung cancer cells via qPCR. Using MTT assay and colony assay to assess the ability of proliferation in lung cancer cells under hypoxia or transfect miR-27a mimics. The capability of migration and invasion was evaluated by wound healing assay and Boyden-chamber assay. The mRNA and protein expression of EMT markers was respectively detected by qPCR and western blot. We detected NRF2 occupancy at the miR-27a promoter by ChIP-Seq analysis. Meanwhile, the luciferase assay verified BUB1 as a direct target of miR-27a.

RESULTS

We found hypoxia promotes lung cancer cell proliferation, migration, invasion, and the epithelial-mesenchymal transition (EMT) process by inhibiting the miR-27a expression. miR-27a mimics significantly reduced the promotion effect of hypoxia on the invasion and proliferation of lung cancer cells. NRF2 as regulating the oxidation/anti-oxidation factor was activated under hypoxia conditions. The activation of NRF2 repressed miR-27a expression. On the contrary, the inhibitory effect of hypoxia on miR-27a was reversed when the NFE2L2 gene was silenced. Ectopic expression of NRF2 inhibited miR-27a expression under normoxia. We further validated BUB1 as a direct target of the miR-27a by luciferase assay.

CONCLUSION

Hypoxia promotes invasion and epithelial-mesenchymal transition of Lung cancer cells by regulating the NRF2/miR-27a/BUB1 axis.

BUB1 Is Identified as a Potential Therapeutic Target for Pancreatic Cancer Treatment

Pancreatic cancer is one of the most challenging cancer types in clinical treatment worldwide. This study aimed to understand the tumorigenesis mechanism and explore potential therapeutic targets for patients with pancreatic cancer. Single-cell data and expression profiles of pancreatic cancer samples and normal tissues from multiple databases were included. Comprehensive bioinformatics analyses were applied to clarify tumor microenvironment and identify key genes involved in cancer development. Immense difference of cell types was shown between tumor and normal samples. Four cell types (B cell_1, B cell_2, cancer cell_3, and CD1C+_B dendritic cell_3) were screened to be significantly associated with prognosis. Three ligand-receptor pairs, including CD74-MIF, CD74-COPA, and CD74-APP, greatly contributed to tumorigenesis. High expression of BUB1 (BUB1 Mitotic Checkpoint Serine/Threonine Kinase) was closely correlated with worse prognosis. CD1C+_B dendritic cell_3 played a key role in tumorigenesis and cancer progression possibly through CD74-MIF. BUB1 can serve as a prognostic biomarker and a therapeutic target for patients with pancreatic cancer. The study provided a novel insight into studying the molecular mechanism of pancreatic cancer development and proposed a potential strategy for exploiting new drugs.