DNA topoisomerase IIα and RAD21 cohesin complex component are predicted as potential therapeutic targets in bladder cancer

NIPBL-mediated RAD21 facilitates tumorigenicity by the PI3K pathway in non-small-cell lung cancer

It is urgent to identify novel early diagnostic markers and therapeutic targets for non-small-cell lung cancer (NSCLC), which accounts for 85% of lung cancer cases and has a 5-year survival rate of 4-17%. Here, chromatin immunoprecipitation (ChIP) was used to identify DNA‒protein interactions, RNA methylation was determined by methylated RNA immunoprecipitation (MeRIP), RNA stability was tested by an RNA decay assay. We showed that RAD21, a member of the cohesin complex, is upregulated in NSCLC tissues and cell lines and found to be an independent prognostic factor for overall survival (OS) of NSCLC patients. Mechanistically, the cohesin loading factor Nipped-B-Like Protein (NIPBL) promoted RAD21 gene transcription by enhancing histone H3 lysine 27 (H3K27) demethylation via recruiting lysine demethylase 6B (KDM6B) to the RAD21 gene promoter. RAD21 enhanced phosphatidylinositol 3-kinase (PI3K) gene transcription, and NIPBL reversed the effect of enhancer of zeste 2; catalytic subunit of polycomb repressive complex 2 (EZH2) on RAD21-mediated PI3K gene transcription by disrupting the association between EZH2 and RAD21. Moreover, NIPBL level was increased by stabilization of its transcripts through mRNA methylation. These findings highlight the oncogenic role of RAD21 in NSCLC and suggest its use as a potential diagnostic marker and therapeutic target for NSCLC.

Homologous recombination mRNAs (RAD21, RAD50 and BARD1) have a potentially poor prognostic role in ERBB2-low bladder cancer patients

Human epidermal growth factor receptor 2 (HER2/ERBB2) factor is known to be implicated in many malignancies and the potential of it as a prognostic biomarker was reported years ago. Molecular subtypes of HER2/ERBB2 negative and positive with distinct clinical outcomes have been identified in recent years; however, it is still under investigation for bladder cancer. This study evaluates the biological and prognostic significance of RAD21, RAD50 and BARD1 (homologous recombination biomarkers) mRNA levels with ERBB2 low and high expression to explore their impact on bladder cancer patient survival and cancer aggressiveness. The expression of ERBB2, RAD21, RAD50 and BARD1 mRNA levels was assessed in The Cancer Genome Atlas (TCGA) bladder cancer dataset along with four validation cohorts. Outcome analysis was evaluated using disease-free survival (DFS) and overall survival (OS). Univariate and multivariate analysis were used to evaluate the relationship between RAD21, RAD50, BARD1 and ERBB2 expression and clinicopathological variables. A significant increase in mRNA expression levels of RAD21, RAD50 and BARD1 was noticed in ERBB2-low patients compared to ERBB2-high patients. This overexpression of the homologous recombination repair transcripts was associated with poor outcome in ERBB2-low tumors, not in ERBB2-high tumors. Furthermore, the combined expression of high RAD21/RAD50, high RAD21/BARD1 or high RAD50/BARD1 were significantly associated with worse DFS and a better outcome for those with low co-expression in the ERBB2-low cohort. High expression of either RAD21/RAD50 or RAD21/BARD1 in ERBB2-low cohort associated with higher chance of metastasis. In addition, gene expression of BARD1 alone or in combination with RAD50 acted as an independent prognostic factor for worst survival. The data presented in this study reveal a connection between RAD21, RAD50, BARD1 and ERBB2 and patient survival. Importantly, it provided novel findings and potential prognostic markers, particularly in ERBB2-low bladder cancer.

A pan-cancer landscape of telomeric content shows that RAD21 and HGF alterations are associated with longer telomeres

Background

Cancer cells can proliferate indefinitely through telomere maintenance mechanisms. These mechanisms include telomerase-dependent elongation, mediated by TERT activation, and alternative lengthening of telomeres (ALT), linked to loss of ATRX or DAXX.

Methods

We analyzed the telomeric content of 89,959 tumor samples within the Foundation Medicine dataset and investigated the genomic determinants of high telomeric content, linking them to clinical outcomes, when available.

Results

Telomeric content varied widely by disease type with leiomyosarcoma having the highest and Merkel cell carcinoma having the lowest telomeric content. In agreement with previous studies, telomeric content was significantly higher in samples with alterations in TERC, ATRX, and DAXX. We further identified that amplifications in two genes, RAD21 and HGF, were enriched in samples with high telomeric content, which was confirmed using the PCAWG/ICGC dataset. We identified the minimal amplified region associated with high telomeric content for RAD21 (8q23.1–8q24.12), which excludes MYC, and for HGF (7q21.11). Our results demonstrated that RAD21 and HGF exerted an additive telomere lengthening effect on samples with existing alterations in canonical genes previously associated with telomere elongation. Furthermore, patients with breast cancer who harbor RAD21 alterations had poor median overall survival and trended towards higher levels of Ki-67 staining.

Conclusions

This study highlights the importance of the role played by RAD21 (8q23.1–8q24.12) and HGF (7q21.11) in the lengthening of telomeres, supporting unlimited replication in tumors. These findings open avenues for work aimed at targeting this crucial pathway in tumorigenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01029-7.

Downregulation of topoisomerase 1 and 2 with acriflavine sensitizes bladder cancer cells to cisplatin-based chemotherapy

BACKGROUND

Resistance to cisplatin is a major obstacle to effective treatment of bladder cancer (BC). The present study aimed to determine whether a combination of acriflavine (ACF) with cisplatin could potentiate the antitumor property of cisplatin against the BC cells. Furthermore, the molecular mechanism behind the anticancer action of ACF was considered.

METHODS AND RESULTS

Two human BC cells (5637 and EJ138) contain mutated form of p53 was culture in standard condition. Cotreatment protocol (simultaneous combination of IC₃₀ value of ACF + various dose of cisplatin for 72 h) and pretreatment protocol (pretreatment with IC₁₅ value of ACF for 24 h + various dose of cisplatin for 48 h) was used to determine the effect of ACF on the cells' sensitivity to main drug cisplatin. To assess the mechanism of action of ACF, real-time PCR was used to evaluate mRNA levels of hypoxia-inducible factor-1α (HIF-1α), Bax, Bcl-2, topoisomerase1 (TOP1) and topoisomerase 2 (TOP2A). Combination of ACF with cisplatin either as cotreatment or opretreatment protocol could significantly reduce the IC₅₀ values of cisplatin as compared to the IC₅₀ of cisplatin when use as a single drug. In addition, ACF could markedly decrease mRNA expression of TOP1 and TOP2A without changing the expression of HIF-1ɑ, Bax and Bcl-2.

CONCLUSIONS

Our findings indicate that combination of cisplatin with ACF was able to significantly enhance the sensitivity of BC cells to cisplatin. The antitumor activity of ACF is exerted through the downregulation of TOP1 and TOP2A genes expression. ACF may serve as an adjuvant to boost cisplatin-based chemotherapy.

Bioinformatics Tools to Understand Notch

As a result of the culmination of data, and the fast-paced advancement of new research, all the biological information collected can make it difficult to sort data. This is oftentimes experienced when learning about the human genome. Fortunately, with the advancement of technology, the field of bioinformatics has emerged which has allowed for the creation of a variety of biological databases. These biological databases provide a condensed reservoir of organized information that is easy to use and topic-specific. Here, we provide a list of 39 biological databases that help break down the fundamental details of a gene. This chapter uses the NOTCH1 gene as an example to demonstrate how biological databases can be used to extract gene information. Five sections were created to highlight the major areas needed to build a comprehensive foundation of NOTCH1. The first section lists databases containing basic gene and protein product information. The next section consists of protein interactions and signaling pathway databases which are essential in understanding the biological processes a gene product is involved in. Gene expression and disease databases are the next two sections which are connected since disease results from the aberrant expression of a gene product. The last database section examines model organisms which serve a key role in the study of human genetic diseases. Using these databases, we can elucidate NOTCH1's gene/protein structure, expression, and vital physiological function through the Notch signaling pathway.

miR-122 Inhibits the Cervical Cancer Development by Targeting the Oncogene RAD21

Cervical cancer (CC) is one of the most frequently diagnosed tumors in female. miR-122 has been proved to be dominant in CC. The particular role of miR-122 in CC is unclear. Thus, we attempted to investigate the prognostic role of miR-122 in CC. We used the database of Kaplan-Meier curve plot. Growth and apoptosis of C33A cells were detected by CCK-8, colony formation assay, transwell assays and flow cytometry analysis. The target gene of miR-122 was identified using bioinformatics, q-PCR, western blot and luciferase assay. It showed that CC patients with overexpression of miR-122 have a better prognosis in the Kaplan-Meier plot database analysis. Overexpressed miR-122 inhibited the malignant growth and induced apoptosis of CC. miR-122 targeting of RAD21 cohesin complex component (RAD21) was identified using bioinformatics, Q-PCR, western blot and luciferase assay analyses. Moreover, we found miR-122 conduct its functions via RAD21 via the PI3K/AKT signaling pathway. Importantly, overexpression of RAD21 restored the roles of miR-122 in CC. Our data suggested that miR-122 could block malignant growth and promoted apoptosis by targeting RAD21 in CC. Our finding indicates miR-122 could potentially participate in the pathogenesis and be a biomarker or the potential therapeutic target of CC.

PUF60/AURKA Axis Contributes to Tumor Progression and Malignant Phenotypes in Bladder Cancer

Abnormal expression or mutation of RNA splicing proteins are widely observed in human cancers. Here, we identified poly(U) binding splicing factor 60 (PUF60) as one of the most differentially expressed genes out of 97 RNA splicing proteins between normal and bladder cancer tissues by bioinformatics analysis of TCGA bladder cancer expression data. The expression of PUF60 was significantly higher in tumor tissues, while high PUF60 expression was associated with malignant phenotypes of bladder cancer and shorter survival time. Moreover, we identified aurora kinase A (AURKA) as a new downstream target of PUF60 in bladder cancer cells. PUF60 knockdown significantly inhibited cell viability and colony formation capacity in bladder cancer cells, whereas AURKA overexpression reversed this inhibition effect. Overexpression of PUF60 significantly promoted cell viability and colony formation in bladder cancer cells, while treatment with AURKA specific inhibitor reversed this promotive effect. Mechanistically, PUF60 specifically bound to the AURKA promoter, thereby activating its transcription and expression. Furthermore, we showed that there was a significant positive correlation between PUF60 and AURKA expression in bladder cancer tissues, and PUF60 and AURKA expression contributed to tumor progression and malignant phenotypes in the patients with bladder cancer. Collectively, these results indicate that the PUF60/AURKA axis plays a key role in regulating tumorigenesis and progression of bladder cancer, and may be a potential prognostic biomarker and therapeutic target for bladder cancer patients.