BUB1B (BUB1 Mitotic Checkpoint Serine/Threonine Kinase B) Promotes Lung Adenocarcinoma by Interacting with Zinc Finger Protein ZNF143 and Regulating Glycolysis

Positive feedback regulation between glycolysis and histone lactylation drives oncogenesis in pancreatic ductal adenocarcinoma

BACKGROUND

Metabolic reprogramming and epigenetic alterations contribute to the aggressiveness of pancreatic ductal adenocarcinoma (PDAC). Lactate-dependent histone modification is a new type of histone mark, which links glycolysis metabolite to the epigenetic process of lactylation. However, the role of histone lactylation in PDAC remains unclear.

METHODS

The level of histone lactylation in PDAC was identified by western blot and immunohistochemistry, and its relationship with the overall survival was evaluated using a Kaplan-Meier survival plot. The participation of histone lactylation in the growth and progression of PDAC was confirmed through inhibition of histone lactylation by glycolysis inhibitors or lactate dehydrogenase A (LDHA) knockdown both in vitro and in vivo. The potential writers and erasers of histone lactylation in PDAC were identified by western blot and functional experiments. The potential target genes of H3K18 lactylation (H3K18la) were screened by CUT&Tag and RNA-seq analyses. The candidate target genes TTK protein kinase (TTK) and BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) were validated through ChIP-qPCR, RT-qPCR and western blot analyses. Next, the effects of these two genes in PDAC were confirmed by knockdown or overexpression. The interaction between TTK and LDHA was identified by Co-IP assay.

RESULTS

Histone lactylation, especially H3K18la level was elevated in PDAC, and the high level of H3K18la was associated with poor prognosis. The suppression of glycolytic activity by different kinds of inhibitors or LDHA knockdown contributed to the anti-tumor effects of PDAC in vitro and in vivo. E1A binding protein p300 (P300) and histone deacetylase 2 were the potential writer and eraser of histone lactylation in PDAC cells, respectively. H3K18la was enriched at the promoters and activated the transcription of mitotic checkpoint regulators TTK and BUB1B. Interestingly, TTK and BUB1B could elevate the expression of P300 which in turn increased glycolysis. Moreover, TTK phosphorylated LDHA at tyrosine 239 (Y239) and activated LDHA, and subsequently upregulated lactate and H3K18la levels.

CONCLUSIONS

The glycolysis-H3K18la-TTK/BUB1B positive feedback loop exacerbates dysfunction in PDAC. These findings delivered a new exploration and significant inter-relationship between lactate metabolic reprogramming and epigenetic regulation, which might pave the way toward novel lactylation treatment strategies in PDAC therapy.

Identification and immunological characteristics of anoikis-associated molecular clusters in lung adenocarcinoma

Anoikis plays a crucial role in the progression, prognosis, and immune response of lung adenocarcinoma (LUAD). However, its specific impact on LUAD remains unclear. In this study, we investigated the intricate interplay of nesting apoptotic factors in LUAD. By analyzing nine key nesting apoptotic factors, we categorized LUAD patients into two distinct clusters. Further examination of immune cell profiles revealed that Cluster A exhibited greater infiltration of innate immune cells than did Cluster B. Additionally, we identified two genes closely associated with prognosis and developed a predictive model to differentiate patients based on molecular clusters. Our findings suggest that the loss of specific anoikis-related genes could significantly influence the prognosis, tumor microenvironment, and clinical features of LUAD patients. Furthermore, we validated the expression and functional roles of two pivotal prognostic genes, solute carrier family 2 member 1 (SLC2A1) and sphingosine kinase 1 (SPHK1), in regulating tumor cell viability, migration, apoptosis, and anoikis. These results offer valuable insights for future mechanistic investigations. In conclusion, this study provides new avenues for advancing our understanding of LUAD, improving prognostic assessments, and developing more effective immunotherapy strategies.

BUB1 inhibition sensitizes lung cancer cell lines to radiotherapy and chemoradiotherapy

Background

Lung cancer is a major public health concern, with high incidence and mortality. Despite advances in targeted therapy and immunotherapy, microtubule stabilizers (paclitaxel, docetaxel), DNA intercalating platinum drugs (cisplatin) and radiation therapy continue to play a critical role in the management of locally advanced and metastatic lung cancer. Novel molecular targets would provide opportunities for improving the efficacies of radiotherapy and chemotherapy.

Hypothesis

We hypothesize that BUB1 (Ser/Thr kinase) is over-expressed in lung cancers and that its inhibition will sensitize lung cancers to chemoradiation.

Methods

BUB1 inhibitor (BAY1816032) was combined with platinum (cisplatin), microtubule poison (paclitaxel), a PARP inhibitor (olaparib) and radiation in cell proliferation and radiation sensitization assays. Biochemical and molecular assays were used to evaluate their impact on DNA damage signaling and cell death mechanisms.

Results

BUB1 expression assessed by immunostaining of lung tumor microarrays (TMAs) confirmed higher BUB1 expression in NSCLC and SCLC compared to that of normal tissues. BUB1 overexpression in lung cancer tissues correlated directly with expression of TP53 mutations in non-small cell lung cancer (NSCLC). Elevated BUB1 levels correlated with poorer overall survival in NSCLC and small cell lung cancer (SCLC) patients. A BUB1 inhibitor (BAY1816032) synergistically sensitized lung cancer cell lines to paclitaxel and olaparib. Additionally, BAY1816032 enhanced cell killing by radiation in both NSCLC and SCLC. Molecular changes following BUB1 inhibition suggest a shift towards pro-apoptotic and anti-proliferative states, indicated by altered expression of BAX, BCL2, PCNA, and Caspases 9 and 3.

Conclusion

A direct correlation between BUB1 protein expression and overall survival was shown. BUB1 inhibition sensitized both NSCLC and SCLC to various chemotherapies (cisplatin, paclitaxel) and targeted therapy (PARPi). Furthermore, we present the novel finding that BUB1 inhibition sensitized both NSCLC and SCLC to radiotherapy and chemoradiation. Our results demonstrate BUB1 inhibition as a promising strategy to sensitize lung cancers to radiation and chemoradiation therapies.

m6A demethylase ALKBH5 maintains stemness of intrahepatic cholangiocarcinoma by sustaining BUB1B expression and cell proliferation

ALKBH5 plays critical roles in various cellular processes via post-transcriptional regulation of oncogenes or tumor suppressors in an N6-methyladenosine (m6A)-dependent manner. However, its function in intrahepatic cholangiocarcinoma (ICC) remains unclear. In the present study, bioinformatic analyses of The Cancer Genome Atlas (TCGA) data were performed, and the association of ALKBH5 in predicting overall survival in patients with ICC was investigated. Then, the clinical data of patients from The Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University (Changzhou, China) was used to reveal the overall survival of patients with ICC with different ALKBH5 expression levels by Kaplan-Meier survival analysis. Subsequently, in vitro and in vivo studies were conducted to explore and verify the downstream genes regulated by ALKBH5. The results from TCGA data demonstrated that ALKBH5 expression is elevated in ICC and that patients with high ALKBH5 expression exhibited poor survival compared with patients with low expression. In addition, in vitro assays demonstrated that ALKBH5 promoted cell viability and maintained the stemness of ICC cells, leading to ICC progression. The present study also demonstrated that BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) is the downstream gene regulated by ALKBH5 and targeting BUB1B suppressed cell growth. The in vitro and vivo experiments revealed that ALKBH5 might function through BUB1B to maintain the stemness of ICC and that altering BUB1B may suppress ICC progression.

Downregulation of BUBR1 regulates the proliferation and cell cycle of breast cancer cells and increases the sensitivity of cells to cisplatin

Breast cancer (BC) is a significant tissue for women's health worldwide. The spindle assembly checkpoint protein family includes BUBR1 (Bub1-related kinase or MAD3/Bub1b). High expression of BUBR1 promotes cell cycle disorders, leading to cell carcinogenesis and cancer progression. However, the underlying molecular mechanism and the role of BUBR1 in BC progression are unclear. The published dataset was analyzed to evaluate the clinical relevance of BUBR1. BUBR1 was knocked down in BC cells using shRNA. The CCK-8 assay was used to measure the cell viability, and mRNA and protein expression levels were detected by RT-qPCR and Western blot (WB). Cell apoptosis and cell cycle were detected by flow cytometry. Subcutaneous xenograft model was used to assess in vivo tumor growth. BUBR1 was found to be highly expressed in BC. The high expression of BUBR1 was associated with poor prognosis of BC patients. Upon BUBR1 knockdown using shRNA, the proliferation and metastatic ability of cells were decreased. Moreover, the cells with BUBR1 knockdown underwent cell cycle arrest. And the results showed that BUBR1 loss inhibited the phosphorylation of TAK1/JNK. In vitro and in vivo studies indicated the knockdown of BUBR1 rendered the BC cells more sensitive to cisplatin. In summary, BUBR1 may be a potential therapeutic target for BC and targeting BUBR1 may help overcome cisplatin resistance in BC patients.

Machine learning-based establishment and validation of age-related patterns for predicting prognosis in non-small cell lung cancer within the context of the tumor microenvironment

Lung cancer (LC) is a leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) accounting for over 80% of cases. The impact of aging on clinical outcomes in NSCLC remains poorly understood, particularly with respect to the immune response. In this study, we explored the effects of aging on NSCLC using 307 genes associated with human aging from the Human Ageing Genomic Resources. We identified 53 aging-associated genes that significantly correlate with overall survival of NSCLC patients, including the clinically validated gene BUB1B. Furthermore, we developed an aging-associated enrichment score to categorize patients based on their aging subtypes and evaluated their prognostic and therapeutic response values in LC. Our analyses yielded two aging-associated subtypes with unique profiles in the tumor microenvironment, demonstrating varying responses to immunotherapy. Consensus clustering based on transcriptome profiles provided insights into the effects of aging on NSCLC and highlighted the potential of personalized therapeutic approaches tailored to aging subtypes. Our findings provide a new target and theoretical support for personalized therapeutic approaches in patients with NSCLC, offering insights into the potential impact of aging on cancer outcomes.

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.

Characteristics of Fatty Acid Metabolism in Lung Adenocarcinoma to Guide Clinical Treatment

Background

Lung adenocarcinoma (LUAD) has a very high morbidity and mortality rate, and its pathogenesis and treatment are still in the exploratory stage. Fatty acid metabolism plays a significant role in tumorigenesis, progression, and immune regulation. However, the gene expression of fatty acid metabolism in patients with LUAD and its relationship with prognosis remain unclear.

Methods

We collected 309 fatty acid metabolism-related genes, established a LUAD risk model based on The Cancer Genome Atlas (TCGA) using Least Absolute Shrinkage Selection Operator (LASSO) regression analysis, and divided LUAD patients into high-risk and low-risk groups, which were further validated using the Gene Expression Omnibus (GEO) database. The nomogram, principal component analysis (PCA), and receiver operating characteristic (ROC) curves showed that the model had the best predictive performance. The ROC curves and calibration plots confirmed that the nomogram had good predictive power. We further analyzed the differences in clinical characteristics, immune cell infiltration, immune-related functions, chemotherapy drug sensitivity, and immunotherapy efficacy between the high-risk and low-risk groups. We also analyzed the enrichment pathways and protein–protein interaction (PPI) networks of different genes in the high-risk and low-risk groups to screen for target genes and further explored the correlation between target genes and differences in survival prognosis, clinical characteristics, gene mutations, and immune cells.

Results

Risk score and staging are independent prognostic factors for patients with LUAD. The high-risk group had lower immune cell infiltration, was more sensitive to chemotherapeutic agents, and had a poorer survival prognosis. We also obtained three pivotal genes with poor survival prognosis in the high expression group, which were strongly associated with clinical symptoms and immune cells.

Conclusion

Risk score and staging are independent prognostic factors for patients with LUAD. The high-risk group had lower immune cell infiltration, was more sensitive to chemotherapeutic agents, and had a poorer survival prognosis. We also obtained three survival prognosis-associated target genes that are closely associated with clinical symptoms and immune cells and may be potential targets for immune-targeted therapy in LUAD.