FBXL20 promotes breast cancer malignancy by inhibiting apoptosis through degradation of PUMA and BAX

Genomic Landscape of Breast Cancer: Study Across Diverse Ethnic Groups

Background: Breast cancer (BC) is the most common cancer among women worldwide, with incidence and mortality rates varying across ethnic groups due to sociodemographic, clinicopathological, and genomic differences. This study aimed to characterize the genomic landscape of BC in diverse ethnic groups using computational tools to explore these variations. Methodology: cBioPortal was used to analyze genomic, clinicopathological, and sociodemographic data from 1084 BC samples. Mutated genes were classified based on GeneCards platform data. Enrichment analysis was performed with CancerHallmarks, and genes not found were compared with MSigDB's Hallmark Gene Sets. Genes absent from both were further analyzed using NDEx through Cytoscape.org to explore their role in cancer. Results: Significant differences (p < 0.05) were observed in sex, tumor subtypes, genetic ancestry, median of the fraction of the altered genome, mutation count, and mutation frequencies of genes across ethnic groups. We identified the most frequently mutated genes. Some of these genes were found to be associated with classic cancer hallmarks, such as replicative immortality, sustained proliferative signaling, and the evasion of growth suppressors. However, the exact role of some of these genes in cancer remains unclear, highlighting the need for further research to better understand their involvement in tumor biology. Conclusions: This study identified significant clinicopathological and genomic variations in BC across ethnic groups. While key genes associated with cancer hallmarks were found, the incomplete characterization of some highlights the need for further research, especially focusing on ethnic groups, to understand their role in tumor biology and improve personalized treatments.

Alkaloid fraction of Achyranthes aspera Linn triggers breast cancer apoptosis in mice (Mus musculus) model

Background

Breast cancer affects women of various ages, and its recurrence is a significant cause of death. The search for potent anticancer compounds of herbal origin with well-defined mechanisms of action is an essential focus of current research.

Aim

This study aimed to investigate the effects of alkaloids in Achyranthes aspera Linn (AAL) leaf extract on necrosis, apoptosis, and related molecular markers, namely, cyclin-dependent kinase 1, Bcl-2 associated X-protein (Bax), rat sarcoma virus (Ras), cytochrome (Cyt) c, and apoptotic activating factor-1 (Apaf-1), in mice models.

Methods

Thirty mice with breast cancer were randomly divided into five groups. The negative control group only received distilled water daily. Mice in the positive control group (PCG) were administered methotrexate (15 mg/Kg) daily. The T1, T2, and T3 groups received oral orally at 75, 100, and 125 mg/Kg body weight daily for 30 days, respectively. On day 31, all mice were euthanized for the preparation of histological specimens of the mammary glands. The negative control group had the lowest number of apoptotic cells, Apaf-1, Cyt C, and Bax expression, and the highest number of viable cancer cells and Ras expression.

Results

The percentages of necrotic cells and breast cancer-expressed CDK-1 were not significantly (p > 0.05) different among groups. The percentage of apoptotic cells, Apaf-1, and Cyt c, was highest in T3. Conversely, the percentage of viable cells and breast cancer-expressing Ras was lowest in T3.

Conclusion

Treatment with 125 mg/Kg AAL suppressed cancer cell growth in breast cancer-bearing mice. Further research is necessary to determine the complete signaling mechanism.

Construction and validation of a ubiquitination-related prognostic risk score signature in breast cancer

Background

Breast cancer (BC) is a highly common form of cancer that occurs in many parts of the world. However, early -stage BC is curable. Many patients with BC have poor prognostic outcomes owing to ineffective diagnostic and therapeutic tools. The ubiquitination system and associated proteins were found influencing the outcome of individuals with cancer. Therefore, developing a biomarker associated with ubiquitination genes to forecast BC patient outcomes is a feasible strategy.

Objective

The primary goal of this work was to develop a novel risk score signature capable of accurately estimate the future outcome of patients with BC by targeting ubiquitinated genes.

Methods

Univariate Cox regression analysis was conducted utilizing the E1, E2, and E3 ubiquitination-related genes in the GSE20685 dataset. Genes with p < 0.01 were screened again using the Non-negative Matrix Factorization (NMF) algorithm, and the resulting hub genes were composed of a risk score signature. Patients were categorized into two risk groups, and the predictive effect was tested using Kaplan-Meier (KM) and Receiver Operating Characteristic (ROC) curves. This risk score signature was later validated using multiple external datasets, namely TCGA-BRAC, GSE1456, GSE16446, GSE20711, GSE58812 and GSE96058. Immuno-microenvironmental, single-cell, and microbial analyses were also performed.

Results

The selected gene signature comprising six ubiquitination-related genes (ATG5, FBXL20, DTX4, BIRC3, TRIM45, and WDR78) showed good prognostic power in patients with BC. It was validated using multiple externally validated datasets, with KM curves showing significant differences in survival (p < 0.05). The KM curves also demonstrated superior predictive ability compared to traditional clinical indicators. Single-cell analysis revealed that Vd2 gd T cells were less abundantin the low-risk group, whereas patients in the high-risk group lacked myeloid dendritic cells. Tumor microbiological analysis revealed a notable variation in microorganism diversity between the high- and low-risk groups.

Conclusion

This study established an risk score signature consisting of six ubiquitination genes, that can accurately forecast the outcome of patients with BC using multiple datasets. It can provide personalized and targeted assistance to provide the evaluation and therapy of individuals having BC.

Transcriptome-wide association study and Mendelian randomization in pancreatic cancer identifies susceptibility genes and causal relationships with type 2 diabetes and venous thromboembolism

BACKGROUND

Two important questions regarding the genetics of pancreatic adenocarcinoma (PDAC) are 1. Which germline genetic variants influence the incidence of this cancer; and 2. Whether PDAC causally predisposes to associated non-malignant phenotypes, such as type 2 diabetes (T2D) and venous thromboembolism (VTE).

METHODS

In this study of 8803 patients with PDAC and 67,523 controls, we first performed a large-scale transcriptome-wide association study to investigate the association between genetically determined gene expression in normal pancreas tissue and PDAC risk. Secondly, we used Mendelian Randomization (MR) to analyse the causal relationships among PDAC, T2D (74,124 cases and 824,006 controls) and VTE (30,234 cases and 172,122 controls).

FINDINGS

Sixteen genes showed an association with PDAC risk (FDR <0.10), including six genes not yet reported for PDAC risk (PPIP5K2, TFR2, HNF4G, LRRC10B, PRC1 and FBXL20) and ten previously reported genes (INHBA, SMC2, ABO, PDX1, MTMR6, ACOT2, PGAP3, STARD3, GSDMB, ADAM33). MR provided support for a causal effect of PDAC on T2D using genetic instruments in the HNF4G and PDX1 loci, and unidirectional causality of VTE on PDAC involving the ABO locus (OR 2.12, P < 1e-7). No evidence of a causal effect of PDAC on VTE was found.

INTERPRETATION

These analyses identified candidate susceptibility genes and disease relationships for PDAC that warrant further investigation. HNF4G and PDX1 may induce PDAC-associated diabetes, whereas ABO may induce the causative effect of VTE on PDAC.

FUNDING

National Institutes of Health (USA).

Pro-apoptotic gene BAX is a pan-cancer predictive biomarker for prognosis and immunotherapy efficacy

BACKGROUND

Apoptosis Regulator BCL2 Associated X (BAX) is a pro-apoptotic gene. Apoptosis is one of the important components of immune response and immune regulation. However, there is no systematic pan-cancer analysis of BAX.

METHODS

Original data of this study were downloaded from TCGA databases and GTEX databases. We conducted the gene expression analysis and survival analysis of BAX in 33 types of cancer via Gene Expression Profiling Interactive Analysis (GEPIA) database. Real-time PCR and immunohistochemistry (IHC) were further performed to examine the BAX expression in cancer cells and tissues. Moreover, the relationship between BAX and immune infiltration and gene alteration was studied by the Tumor Immune Estimation Resource (TIMER) and cBioPortal tools. Protein-protein interaction analysis was performed in the STRING database. Finally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were utilized to evaluate the enrichment analysis.

RESULTS

BAX was highly expressed in most cancers and was associated with poor prognosis in nine cancer types. In addition, BAX showed significant clinical relevance, and the mRNA expression of BAX was also strongly associated with drug sensitivity of many drugs. Furthermore, BAX may participate in proliferation and metastasis of many cancers and was associated with methylation. Importantly, BAX expression was positively correlated with most immune infiltrating cells.

CONCLUSION

Our findings suggested that BAX can function as an oncogene and may be used as a potential predictive biomarker for prognosis and immunotherapy efficacy of human cancer, which could provide a new approach for cancer therapy.

Homoharringtonine induces apoptosis of mammary carcinoma cells by inhibiting the AKT/mTOR signaling pathway

Mammary tumour is the most common type of tumour in dogs, especially in unneutered female dogs. Homoharringtonine (HHT) is a natural alkaloid that can be used to treat various types of human tumour. However, the inhibitory effect and mechanism of HHT on canine mammary carcinomas (CMC) remain unclear. This study aimed to evaluate the inhibitory effect of HHT on CMC in vitro and determine its underlying molecular mechanism. The effects of HHT on the cytotoxicity of CMC U27 cells were evaluated by the cell counting kit-8, wound healing, and Transwell assays. HHT-induced apoptosis of U27 cells was detected by JC-1 and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. Moreover, the gene expression of B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) were analysed using quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and the protein expression of protein kinase B/mammalian target of rapamycin (AKT/mTOR) and mitochondrial apoptosis proteins were determined by western blotting. Furthermore, mammary tumour-bearing mouse models were established using 4T1 cells to evaluate the therapeutic effect of HHT. It was found that HHT could significantly down-regulated the protein expression of p-AKT, p-mTOR, and Bcl-2, and up-regulated the protein expression of P53, Bax, cleaved caspase-3, and cleaved caspase-9. In addition, HHT significantly suppressed both tumour volume and mass in mammary tumour mice. In conclusion, HHT damages CMC cells by inhibiting the AKT/mTOR signalling pathway and inducing mitochondrial apoptosis. Such findings lay a theoretical foundation for the clinical treatment of CMC and provide more options for clinical medication.

Knocking down NSUN5 inhibits the development of clear cell renal cell carcinoma by inhibiting the p53 pathway

Clear cell renal cell carcinoma (ccRCC) is the most common solid renal tumor. NSUN5, a gene encoding cytosine-5 RNA methyltransferase, has rarely been reported associated with cancer. A bioinformatics analysis revealed that NSUN5 was overexpressed in ccRCC. Gene Ontology and gene set variation analyses showed that NSUN5 was associated with tumor immunity in ccRCC. The effect of immunosuppressive treatment was superior in the low-risk group compared to the high-risk group, and higher stromal score in the high-risk group relative to the low-risk group. A drug sensitivity analysis revealed that the high-risk group was more sensitive to 5-fluorouracil, mitomycin C, methotrexate, and 17-AAG, whereas the low-risk group was more sensitive to crizotinib, sorafenib, foretinib, and ivozanib. NSUN5 knockout decreased ccRCC cell proliferation. The migration speed and number of invasive cells further decreased. The percentage of apoptotic cells increased. In NSUN5-knockout cells, the levels of BAX, caspase-8, caspase-9, and p53 increased significantly, whereas those of Bcl2, CCND1, CCND3, and MMP9 decreased significantly. NSUN5 is highly expressed in ccRCC and inhibits cancer cell invasion, proliferation, and migration while promoting apoptosis by activating the p53 signaling pathway. This study provides insights into the mechanisms of action of NSUN5 in urological tumors and may contribute to improving ccRCC treatment options.

Asymmetrically Coordinated Heterodimetallic Ir-Ru System: Synthesis, Computational, and Anticancer Aspects

Herein, we present an unprecedented formation of a heterodinuclear complex [{(ppy)₂Ir^III}(μ-phpy){Ru^II(tpy)}](ClO₄)₂ {[1](ClO₄)₂} using terpyridyl/phenylpyridine as ancillary ligands and asymmetric phpy as a bridging ligand. The asymmetric binding mode (N^∧N-∩-N^∧N^∧C^-) of the phpy ligand in {[1](ClO₄)₂} is confirmed by ¹H, ¹³C, ¹H-¹H correlated spectroscopy (COSY), high-resolution mass spectrum (HRMS), single-crystal X-ray crystallography techniques, and solution conductivity measurements. Theoretical investigation suggests that the highest occupied molecular orbital (HOMO) and the least unoccupied molecular orbital (LUMO) of [1]²⁺ are located on iridium/ppy and phpy, respectively. The complex displays a broad low energy charge transfer (CT) band within 450-575 nm. The time-dependent density functional theory (TDDFT) analysis suggests this as a mixture of metal-to-ligand charge transfer (MLCT) and ligand-to-ligand charge transfer (LLCT), where both ruthenium, iridium, and ligands are involved. Complex {[1](ClO₄)₂} exhibits Ru^IIIr^III/Ru^IIIIr^III- and Ru^IIIIr^III/Ru^IIIIr^IV-based oxidative couples at 0.83 and 1.39 V, respectively. The complex shows anticancer activity and selectivity toward human breast cancer cells (IC₅₀; MCF-7: 9.3 ± 1.2 μM, and MDA-MB-231: 8.6 ± 1.2 μM) over normal breast cells (MCF 10A: IC₅₀ ≈ 21 ± 1.3 μM). The Western blot analysis and fluorescence microscopy images suggest that combined apoptosis and autophagy are responsible for cancer cell death.

Ginsenoside Rh2 Induces HeLa Apoptosis through Upregulating Endoplasmic Reticulum Stress-Related and Downstream Apoptotic Gene Expression

Cervical cancer is a common gynecological malignancy afflicting women all over the world. Ginsenoside Rh2 (GRh2), especially 20(S)-GRh2, is a biologically active component in the natural plant ginseng, which can exhibit anticancer effects. Here, we aimed to investigate the effect of 20(S)-GRh2 on cervical cancer and elucidate the underlying mechanism through RNA-seq. In this study, the CCK-8 assay showed that 20(S)-GRh2 inhibited HeLa cell viability in a time- and dose-dependent manner. Caspase 3 activity and Annexin V staining results showed that 20(S)-GRh2 induced apoptosis of HeLa cells. Gene function enrichment analysis revealed that the biological process gene ontology (GO) terms were associated with the apoptotic signaling pathway. Biological process GO terms' similarity network indicated that apoptosis might be from endoplasmic reticulum stress (ERs). Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that 20(S)-GRh2 primarily modulates apoptosis pathway genes. Combined protein-protein interaction network, hub gene screening, and qPCR validation data showed that ERs-related genes (ATF4 and DDIT3) and the downstream apoptotic genes (JUN, FOS, BBC3, and PMAIP1) were potential novel targets of 20(S)-GRh2-inducing cervical cancer cell apoptosis. Differential transcript usage analysis indicated that DDIT3 is also a differential transcript and its usage of the isoform (ENST00000552740.5) was reduced by 20(S)-GRh2. Molecular docking suggested that 20(S)-GRh2 binds to the targets (ATF4, DDIT3, JUN, FOS, BBC3, and PMAIP1) with high affinity. In conclusion, our findings indicated that 20(S)-GRh2 might promote ERs-related apoptosis of cervical cancer cells by regulating the DDIT3-based targets' signal pathway. The role of 20(S)-GRh2 at the transcriptome level provides novel targets and evidence for the treatment of cervical cancer.

Isobavachalcone Induces Multiple Cell Death in Human Triple-Negative Breast Cancer MDA-MB-231 Cells

Standardized treatment guidelines and effective drugs are not available for human triple-negative breast cancer (TNBC). Many efforts have recently been exerted to investigate the efficacy of natural compounds as anticancer agents owing to their low toxicity. However, no study has examined the effects of isobavachalcone (IBC) on the programmed cell death (PCD) of human triple-negative breast MDA-MB-231 cancer cells. In this study, IBC substantially inhibited the proliferation of MDA-MB-231 cells in concentration- and time-dependent manners. In addition, we found that IBC induced multiple cell death processes, such as apoptosis, necroptosis, and autophagy in MDA-MB-231 cells. The initial mechanism of IBC-mediated cell death in MDA-MB-231 cells involves the downregulation of Akt and p-Akt-473, an increase in the Bax/Bcl-2 ratio, and cleaved caspases-3 induced apoptosis; the upregulation of RIP3, p-RIP3 and MLKL induced necroptosis; as well as a simultaneous increase in LC3-II/I ratio induced autophagy. In addition, we observed that IBC induced mitochondrial dysfunction, thereby decreasing cellular ATP levels and increasing reactive oxygen species accumulation to induce PCD. These results suggest that IBC is a promising lead compound with anti-TNBC activity.

FBXL20-mediated ubiquitination triggers the proteasomal degradation of 4-1BB

4-1BB [tumor necrosis factor receptor superfamily (TNFRSF9), CD137) is a critical immune stimulator that sustains T cell activity and antitumor immune response. The strategy to eliminate cancers by agonistically targeting 4-1BB is under clinical investigation. As a protein expressed in an inducible manner, 4-1BB is under tight control on both transcription and translation levels to maintain its homeostasis. So far, the mechanisms underlying the transcriptional activation of 4-1BB have been well-interpreted; however, it remains inexplicit how 4-1BB is regulated on the protein level. In this study, we presented experimental evidence supporting that 4-1BB, especially the heavily N-glycosylated (mature) form, is polyubiquitinated and subjected to the ubiquitin-proteasomal system for degradation. By performing proximity-dependent biotin identification screening coupled with biochemical assays, we identified that F-box/LRR-repeat protein 20 acts as the E3 ligase that promotes the polyubiquitination of 4-1BB at the intracellular domain. Our data provided mechanistic insight into 4-1BB regulation on the protein level by unmasking, for the first time, a posttranslational mechanism governing 4-1BB abundance in cells. The findings of this study could potentially guide the development of 4-1BB-targeted therapy for cancers as well as other immune disorders.