FBXW7 and the Hallmarks of Cancer: Underlying Mechanisms and Prospective Strategies

Characteristics of genomic alterations and heavy metals in hypertensive patients with non‑small cell lung cancer

Both lung cancer and cardiovascular disease (CVD) are prevalent diseases that contribute to global mortality rates. Although individuals with CVD may face an elevated risk of cancer based on the presence of shared risk factors (such as tobacco smoking and excessive body weight), the roles of somatic mutations and heavy metal distributions remain unknown. The present study aimed to explore the differences in somatic mutations and heavy metal distributions between hypertensive patients and non-hypertensive patients in a cohort of patients with non-small cell lung cancer (NSCLC). Tumor tissue samples from 64 patients were analyzed using a next-generation sequencing panel consisting of 82 tumor-related genes through hybrid capture. Serum samples were also analyzed to determine the levels of 18 heavy metals using inductively-coupled plasma mass spectrometry. Among the 16 hypertensive patients, all patients (16/16; 100.00%) harbored 47 somatic mutations in 14 mutant genes, whereas 45 patients without hypertension (45/48; 93.75%) harbored 113 somatic mutations across 26 mutant genes (no mutations were detected in the remaining 3 patients). Among the 32 identified mutant genes in these two groups, FBXW7, CBR3, CDKN2A, HRAS, SMO and UGT1A1 were exclusively observed in patients with hypertension, while 18 mutant genes were only observed in patients without hypertension. No significant mutually exclusive interactions were found in hypertensive patients, but mutually exclusive interactions were observed between EGFR and STK11 (P=0.0240) and between STK11 and KRAS (P=0.0169) in non-hypertensive patients. 'Non-small cell lung cancer' was the top Kyoto Encyclopedia of Genes and Genomes pathway in hypertensive patients, whereas 'central carbon metabolism in cancer' was the top pathway in patients without hypertension. Moreover, the proportions of altered key signaling pathways and biological function categories shared between these two groups were 54.37% (56/103) and 21.62% (8/37), respectively. Furthermore, the levels of chromium (Cr) in the serum of hypertensive patients were notably elevated compared with those in patients without hypertension. In addition, significant negative correlations were observed between Cr and CEA, between CYFRA21-1 and Zn, and between NSE and As in hypertensive patients but not in non-hypertensive patients, indicating differing interactive profiles among the traditional serum biomarkers and heavy metals between these two patient groups. In summary, there were differences in genomic alterations, somatic interactions and the serum levels of Cr between patients with NSCLC with hypertension and patients with NSCLC without hypertension. Furthermore, patients with hypertension exhibited significant negative correlations between Cr and CEA, between CYFRA21-1 and Zn, and between NSE and As, suggesting that heavy metals may contribute to the occurrence of NSCLC with different hypertensive status.

FBXW7 metabolic reprogramming inhibits the development of colon cancer by down-regulating the activity of arginine/mToR pathways

FBXW7 is a tumor suppressor gene that regulates metabolism and is associated with the onset and progression of colorectal cancer (CRC)), however, the precise mechanism whereby FBXW7 participates in the metabolic reprogramming of CRC remains unclear. Here, the research aims to reveal the association between the expression of FBXW7 and clinical variables and to investigate the molecular mechanism by which FBXW7 plays a critical role in the development of CRC. The clinical importance of FBXW7 in CRC was determined by immunohistochemistry. Non-targeted metabolomics was utilized to explore the role of FBXW7 in the metabolic regulation of CRC. Low expression of FBXW7 was associated with poor prognosis in individuals with CRC, both at the mRNA and protein levels. FBXW7 over-expression inhibited CRC cell growth, colony formation, migration, and invasion. Non-targeted metabolomics unveiled that FBXW7 over-expression directly caused the deprivation of arginine which led to downmodulation of mTOR signaling pathway; meanwhile, FBXW7-related metabolites were primarily concentrated in the mTOR signaling pathway. In summary, the research identified a novel mechanism of action of FBXW7 in CRC. The research findings provide a theoretical foundation for the prognostic prediction and therapeutic planning of CRC based on metabolic reprogramming.

Computational analysis of MYC gene variants: structural and functional impact of non-synonymous SNPs

The MYC proto-oncogene encodes a basic helix-loop-helix leucine zipper (HLH-LZ) transcription factor, acting as a master regulator of genes involved in cellular proliferation, differentiation, and immune surveillance. Dysregulation of MYC is implicated in over 70% of human cancers, driving oncogenic processes through altered gene expression and disrupted cellular functions. Non-synonymous single nucleotide polymorphisms (nsSNPs) within coding regions can significantly impact protein structure and function, leading to abnormal cellular behaviours. This study employed 29 in silico tools to systematically evaluate the deleteriousness of nsSNPs within the MYC gene. These tools assessed the variants' effects on protein structure, disease association, functional domains, and post-translational modification sites. This study investigated if these variants may disrupt protein-protein interactions, critical for MYC's oncogenic roles and normal cellular functions. Our analysis identified 21 nsSNPs that were predicted to be deleterious and pathogenic. These variants correspond to residues D63H, D63Y, P74L, P75L, N375D, N375I, E378K, E378Q, E378A, E378G, E378V, R379P, R381K, R381T, R382W, L392P, R393C, R393H, R393P, L411H, and L411P. Stability assessments indicated that these variants could destabilise the MYC protein. None of the variants affected post-translational modifications. Protein-protein interaction and docking analysis revealed that variants within bHLH and LZ domains may disrupt MYC/MAX binding, potentially impacting MYC's oncogenic activity and transcriptional regulation. This computational assessment enhances our understanding of genetic variations within the MYC gene and prioritises candidate nsSNPs for experimental validation and therapeutic exploration.

miR-182-5p promotes the proliferation and invasion of hilar cholangiocarcinoma cells by inhibiting FBXW7

BACKGROUND

Hilar cholangiocarcinoma (HCCA) is a common type of cholangiocarcinoma (CHOL) that originates from the right and/or left hepatic duct near the biliary tract confluence. The objective of this study is to investigate the impact of miR-182-5p on the proliferation and invasion of HCCA cells and identify a potential target for HCCA treatment.

METHODS

HCCA tissues were collected and HCCA cells were cultured. miR-182-5p and F-box and WD repeat domain containing 7 (FBXW7) were detected. After transfection of miR-182-5p inhibitor into HCCA cells, cell proliferation and invasion were detected by cell counting 8-kit and Transwell assay. FBXW7 expression was detected by Western blot. The targeted relationship between miR-182-5p and FBXW7 3'UTR was verified by dual-luciferase report assay. si-FBXW7 and miR-182-5p inhibitor were transfected into cells for combined experiments. HCCA cells with lowly-expressed miR-182-5p were injected into nude mice to establish the xenograft tumor model, and subsequent observations were made on tumor growth and gene expression changes.

RESULTS

miR-182-5p exhibited high expression levels in both HCCA tissues and cell lines. Inhibiting miR-182-5p effectively suppressed the proliferation and migration of HCCA cells. miR-182-5p bounded to FBXW7 3 'UTR and inhibited FBWX7 expression. Suppressing FBXW7 expression partially reversed the inhibitory effect of miR-182-5p inhibitor on HCCA cell proliferation and invasion. Silencing miR-182-5p could inhibit the HCCA growth in vivo.

CONCLUSION

miR-182-5p promoted the proliferation and invasion of HCCA cells by targeting and inhibiting FBXW7 expression.

The FBXW7-binding sites on FAM83D are potential targets for cancer therapy

Increasing evidence shows the oncogenic function of FAM83D in human cancer, but how FAM83D exerts its oncogenic function remains largely unclear. Here, we investigated the importance of FAM83D/FBXW7 interaction in breast cancer (BC). We systematically mapped the FBXW7-binding sites on FAM83D through a comprehensive mutational analysis together with co-immunoprecipitation assay. Mutations at the FBXW7-binding sites on FAM83D led to that FAM83D lost its capability to promote the ubiquitination and proteasomal degradation of FBXW7; cell proliferation, migration, and invasion in vitro; and tumor growth and metastasis in vivo, indicating that the FBXW7-binding sites on FAM83D are essential for its oncogenic functions. A meta-evaluation of FAM83D revealed that the prognostic impact of FAM83D was independent on molecular subtypes. The higher expression of FAM83D has poorer prognosis. Moreover, high expression of FAM83D confers resistance to chemotherapy in BCs, which is experimentally validated in vitro. We conclude that identification of FBXW7-binding sites on FAM83D not only reveals the importance for FAM83D oncogenic function, but also provides valuable insights for drug target.

Comprehensive characterization of PKHD1 mutation in human colon cancer

INTRODUCTION

The PKHD1 (Polycystic Kidney and Hepatic Disease 1) gene is essential for producing fibrocystin or polyductin, which is crucial in various cellular functions. Mutations in PKHD1 have been found to be involved in the development and progression of colorectal cancer (CRC). Along with APC, TP53, and KRAS, PKHD1 is one of the most frequently mutated genes in CRC. PKHD1 expression is governed by the Wnt/PCP pathway, often dysregulated in CRC. Targeting this pathway, crucial for CRC progression, could unveil potential therapeutic strategies for colon cancer treatment.

METHODS

This study examined an in-house dataset of 3702 colon cancer samples, analyzing mutation landscapes, clinical features, tumor mutational burden (TMB), microsatellite instability (MSI), and chromosomal instability (CIN) score. For the survival analysis of PKHD1 patients, survival data of 436 colon adenocarcinoma samples were obtained from TCGA dataset. Additionally, 433 samples from TCGA with RNA-seq data were used for the assessment of immune cell infiltration and gene set enrichment analysis.

RESULTS

Polycystic Kidney and Hepatic Disease 1 mutation was detected in 424 colon cancer patients from our in-house cohort and was associated with increased TMB, higher MSI, and lower CIN score. Importantly, within the TCGA dataset, PKHD1 mutations were identified as an independent prognostic factor, not merely correlated with established prognostic biomarkers, and were associated with poorer overall survival outcomes. In terms of immune response, these mutations correlated with increased enrichment scores for 12 immune cell types, including B cell plasma, macrophages, and naive CD4+ T cells. Additionally, interferon alpha and interferon-gamma gene sets were significantly down-regulated in patients with PKHD1 mutations (FDA q-value < 0.1).

CONCLUSIONS

Overall, these findings suggest that PKHD1 may be a potential biomarker for the prognosis of colon cancer and provide some insight for personalized immunotherapy.

FBXW7 and human tumors: mechanisms of drug resistance and potential therapeutic strategies

Drug therapy, including chemotherapy, targeted therapy, immunotherapy, and endocrine therapy, stands as the foremost therapeutic approach for contemporary human malignancies. However, increasing drug resistance during antineoplastic therapy has become a substantial barrier to favorable outcomes in cancer patients. To enhance the effectiveness of different cancer therapies, an in-depth understanding of the unique mechanisms underlying tumor drug resistance and the subsequent surmounting of antitumor drug resistance is required. Recently, F-box and WD Repeat Domain-containing-7 (FBXW7), a recognized tumor suppressor, has been found to be highly associated with tumor therapy resistance. This review provides a comprehensive summary of the underlying mechanisms through which FBXW7 facilitates the development of drug resistance in cancer. Additionally, this review elucidates the role of FBXW7 in therapeutic resistance of various types of human tumors. The strategies and challenges implicated in overcoming tumor therapy resistance by targeting FBXW7 are also discussed.

Inhibition of the NOTCH and mTOR pathways by nelfinavir as a novel treatment for T cell acute lymphoblastic leukemia

T cell acute lymphoblastic leukemia (T‑ALL), a neoplasm derived from T cell lineage‑committed lymphoblasts, is characterized by genetic alterations that result in activation of oncogenic transcription factors and the NOTCH1 pathway activation. The NOTCH is a transmembrane receptor protein activated by γ‑secretase. γ‑secretase inhibitors (GSIs) are a NOTCH‑targeted therapy for T‑ALL. However, their clinical application has not been successful due to adverse events (primarily gastrointestinal toxicity), limited efficacy, and drug resistance caused by several mechanisms, including activation of the AKT/mTOR pathway. Nelfinavir is an human immunodeficiency virus 1 aspartic protease inhibitor and has been repurposed as an anticancer drug. It acts by inducing endoplasmic reticulum (ER) stress and inhibiting the AKT/mTOR pathway. Thus, it was hypothesized that nelfinavir might inhibit the NOTCH pathway via γ‑secretase inhibition and blockade of aspartic protease presenilin, which would make nelfinavir effective against NOTCH‑associated T‑ALL. The present study assessed the efficacy of nelfinavir against T‑ALL cells and investigated mechanisms of action in vitro and in preclinical treatment studies using a SCL‑LMO1 transgenic mouse model. Nelfinavir blocks presenilin 1 processing and inhibits γ‑secretase activity as well as the NOTCH1 pathway, thus suppressing T‑ALL cell viability. Additionally, microarray analysis of nelfinavir‑treated T‑ALL cells showed that nelfinavir upregulated mRNA levels of CHAC1 (glutathione‑specific γ‑glutamylcyclotransferase 1, a negative regulator of NOTCH) and sestrin 2 (SESN2; a negative regulator of mTOR). As both factors are upregulated by ER stress, this confirmed that nelfinavir induced ER stress in T‑ALL cells. Moreover, nelfinavir suppressed NOTCH1 mRNA expression in microarray analyses. These findings suggest that nelfinavir inhibited the NOTCH1 pathway by downregulating NOTCH1 mRNA expression, upregulating CHAC1 and suppressing γ‑secretase via presenilin 1 inhibition and the mTOR pathway by upregulating SESN2 via ER stress induction. Further, nelfinavir exhibited therapeutic efficacy against T‑ALL in an SCL‑LMO1 transgenic mouse model. Collectively, these findings highlight the potential of nelfinavir as a novel therapeutic candidate for treatment of patients with T‑ALL.

Down-Regulation of CYP3A4 by the KCa1.1 Inhibition Is Responsible for Overcoming Resistance to Doxorubicin in Cancer Spheroid Models

The large-conductance Ca2+-activated K+ channel, KCa1.1, plays a pivotal role in cancer progression, metastasis, and the acquisition of chemoresistance. Previous studies indicated that the pharmacological inhibition of KCa1.1 overcame resistance to doxorubicin (DOX) by down-regulating multidrug resistance-associated proteins in the three-dimensional spheroid models of human prostate cancer LNCaP, osteosarcoma MG-63, and chondrosarcoma SW-1353 cells. Investigations have recently focused on the critical roles of intratumoral, drug-metabolizing cytochrome P450 enzymes (CYPs) in chemoresistance. In the present study, we examined the involvement of CYPs in the acquisition of DOX resistance and its overcoming by inhibiting KCa1.1 in cancer spheroid models. Among the CYP isoforms involved in DOX metabolism, CYP3A4 was up-regulated by spheroid formation and significantly suppressed by the inhibition of KCa1.1 through the transcriptional repression of CCAAT/enhancer-binding protein, CEBPB, which is a downstream transcription factor of the Nrf2 signaling pathway. DOX resistance was overcome by the siRNA-mediated inhibition of CYP3A4 and treatment with the potent CYP3A4 inhibitor, ketoconazole, in cancer spheroid models. The phosphorylation levels of Akt were significantly reduced by inhibiting KCa1.1 in cancer spheroid models, and KCa1.1-induced down-regulation of CYP3A4 was reversed by the treatment with Akt and Nrf2 activators. Collectively, the present results indicate that the up-regulation of CYP3A4 is responsible for the acquisition of DOX resistance in cancer spheroid models, and the inhibition of KCa1.1 overcame DOX resistance by repressing CYP3A4 transcription mainly through the Akt-Nrf2-CEBPB axis.

MicroRNA-92b targets tumor suppressor gene FBXW7 in glioblastoma

Introduction

Glioblastoma (GBM) is a highly aggressive and lethal primary brain tumor. Despite limited treatment options, the overall survival of GBM patients has shown minimal improvement over the past two decades. Factors such as delayed cancer diagnosis, tumor heterogeneity, cancer stem cell survival, infiltrative nature of GBM cells, metabolic reprogramming, and development of therapy resistance contribute to treatment failure. To address these challenges, multitargeted therapies are urgently needed for improved GBM treatment outcomes. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. Dysregulated miRNAs have been identified in GBM, playing roles in tumor initiation, progression, and maintenance. Among these miRNAs, miR-92b (miRNA-92b-3p) has been found to be overexpressed in various cancers, including GBM. However, the specific target genes of miR-92b and its therapeutic potential in GBM remain poorly explored.

Methods

Samples encompassed T98G, U87, and A172 human GBM cell lines, GBM tumors from Puerto Rican patients, and murine tumors. In-situ hybridization (ISH) assessed miR-92b expression in patient tumors. Transient and stable transfections modified miR-92b levels in GBM cell lines. Real-time PCR gauged gene expressions. Caspase 3 and Trypan Blue assays evaluated apoptosis and viability. Bioinformatics tools (TargetScanHuman 8.0, miRDB, Diana tools, miRWalk) predicted targets. Luciferase assays and Western Blots validated miRNA-target interactions. A subcutaneous GBM Xenograft mouse model received intraperitoneal NC-OMIs or miR92b-OMIs encapsulated in liposomes, three-times per week for two weeks. Analysis utilized GraphPad Prism 8; statistical significance was assessed using 2-tailed, unpaired Student's t-test and two-way ANOVA as required.

Results

This study investigated the expression of miR-92b in GBM tumors compared to normal brain tissue samples, revealing a significant upregulation. Inhibition of miR-92b using oligonucleotide microRNA inhibitors (OMIs) suppressed GBM cell growth, migration, and induced apoptosis, while ectopic expression of miR-92b yielded opposite effects. Systemic administration of liposomal-miR92b-OMIs in GBM xenograft mice resulted in reductions in tumor volume and weight. Subsequent experiments identified F-Box and WD Repeat Domain Containing 7 (FBXW7) as a direct target gene of miR-92b in GBM cells.

Discussion

FBXW7 acts as a tumor suppressor gene in various cancer types, and analysis of patient data demonstrated that GBM patients with higher FBXW7 mRNA levels had significantly better overall survival compared to those with lower levels. Taken together, our findings suggest that the dysregulated expression of miR-92b in GBM contributes to tumor progression by targeting FBXW7. These results highlight the potential of miR-92b as a therapeutic target for GBM. Further exploration and development of miR-92b-targeted therapies may offer a novel approach to improve treatment outcomes in GBM patients.

Comparative Genomic Analysis of Pancreatic Acinar Cell Carcinoma (PACC) and Pancreatic Ductal Adenocarcinoma (PDAC) Unveils New Actionable Genomic Aberrations in PACC

PURPOSE

Pure pancreatic acinar cell carcinomas (PACC) are rare malignancies with no established treatment. PACC demonstrates significant genetic intertumoral heterogeneity with multiple pathways involved, suggesting using targeted cancer therapeutics to treat this disease. We aggregated one of the largest datasets of pure PACC to examine the genomic variability and explore patient-specific therapeutic targets.

EXPERIMENTAL DESIGN

PACC specimens (n = 51) underwent next-generation sequencing of DNA (n = 29) or whole exome (n = 22) and RNA (whole transcriptome, n = 29) at a commercial laboratory. We performed comparative analyses of a genomic cohort of pancreatic ductal adenocarcinomas (PDAC; n = 4,205). In parallel, we conducted a retrospective review of patients with PACC treated at Huntsman Cancer Institute (HCI).

RESULTS

The real-world dataset included samples from 51 patients with PACC. We found key molecular differences between pure PACC and PDAC, highlighting the unique characteristics of pure PACC. Major differences in PACC include lower MAPK signaling and less stromal cell abundance compared with PDAC. Pure PACC showed genomic loss-of-heterozygosity to largely coincide with mutations in BRCA1, BRCA2, and PALB2. Of the 7 patients treated at HCI, one had a tumor that harbored a BRAF-V600E mutation. Leveraging precision oncology, this patient is being treated with encorafenib plus binimetinib, achieving an exceptionally durable and ongoing complete response of more than 3 years.

CONCLUSIONS

There are major differences between PACC and PDAC, including downregulation of the MAPK signaling pathway, and less stromal cell abundance. In addition, genomic characterization of pure PACC revealed frequent targetable alterations, which can guide patient treatment.

Elucidating the role of ubiquitination and deubiquitination in osteoarthritis progression

Osteoarthritis is non-inflammatory degenerative joint arthritis, which exacerbates disability in elder persons. The molecular mechanisms of osteoarthritis are elusive. Ubiquitination, one type of post-translational modifications, has been demonstrated to accelerate or ameliorate the development and progression of osteoarthritis via targeting specific proteins for ubiquitination and determining protein stability and localization. Ubiquitination process can be reversed by a class of deubiquitinases via deubiquitination. In this review, we summarize the current knowledge regarding the multifaceted role of E3 ubiquitin ligases in the pathogenesis of osteoarthritis. We also describe the molecular insight of deubiquitinases into osteoarthritis processes. Moreover, we highlight the multiple compounds that target E3 ubiquitin ligases or deubiquitinases to influence osteoarthritis progression. We discuss the challenge and future perspectives via modulation of E3 ubiquitin ligases and deubiquitinases expression for enhancement of the therapeutic efficacy in osteoarthritis patients. We conclude that modulating ubiquitination and deubiquitination could alleviate the osteoarthritis pathogenesis to achieve the better treatment outcomes in osteoarthritis patients.

The Role of FBXW7 in Gynecologic Malignancies

The F-Box and WD Repeat Domain Containing 7 (FBXW7) protein has been shown to regulate cellular growth and act as a tumor suppressor. This protein, also known as FBW7, hCDC4, SEL10 or hAGO, is encoded by the gene FBXW7. It is a crucial component of the Skp1-Cullin1-F-box (SCF) complex, which is a ubiquitin ligase. This complex aids in the degradation of many oncoproteins, such as cyclin E, c-JUN, c-MYC, NOTCH, and MCL1, via the ubiquitin-proteasome system (UPS). The FBXW7 gene is commonly mutated or deleted in numerous types of cancer, including gynecologic cancers (GCs). Such FBXW7 mutations are linked to a poor prognosis due to increased treatment resistance. Hence, detection of the FBXW7 mutation may possibly be an appropriate diagnostic and prognostic biomarker that plays a central role in determining suitable individualized management. Recent studies also suggest that, under specific circumstances, FBXW7 may act as an oncogene. There is mounting evidence indicating that the aberrant expression of FBXW7 is involved in the development of GCs. The aim of this review is to give an update on the role of FBXW7 as a potential biomarker and also as a therapeutic target for novel treatments, particularly in the management of GCs.

Molecular profiling of primary uveal melanoma: results of a Polish cohort

There is no published data regarding the molecular alterations of Polish patients with primary uveal melanoma. We performed whole exome sequencing of 20 primary uveal melanomas (UMs), 10 metastasizing and 10 non-metastasizing cases to identify significant molecular alterations. We detected mutations and copy number variants in the BAP1 gene in 50% (10 cases) of the cases. GNA11 mutations were detected in 50% (10 cases) including nine p.Q209L and one p.R183C. GNAQ mutations gene were detected in 40% (8 cases) and all were p.Q209P. SF3B1, EIF1AX, PLCB4 , and PALB2 mutations were detected in one case each. Genetic aberrations of FBXW7 were detected in 55% of cases, with copy number loss of 10 and missense mutation in one. Gain or loss of copy number was observed in 60%, 60%, and 10% of cases in MYC, MLH1 , and CDKN2A genes, respectively. BAP1 and GNAQ tumor suppressor genes are more often mutated in UM with metastasis, while GNA11 mutations are more frequently detected in non-metastasizing tumors. MYC copy gain was present twice as frequently (80% versus 40%) in cases with versus those without metastases. BAP1 mutation correlated with worse overall survival; while GNA11 mutation and CDKN2A loss correlated with better and worse progression-free survival, respectively. We have confirmed BAP1 prognostic potential and documented frequent MYC amplification in metastasizing cases. Although GNA11 mutation and CDKN2A loss significantly correlated with progression-free survival in our study, our sample size is small. The prognostic significance of GNAQ/GNA11 mutation and CDKN2A loss would require further investigation.

Comprehensive characterization of FBXW7 mutational and clinicopathological profiles in human colorectal cancers

Background

FBXW7 is recognized as a critical tumor suppressor gene and a component of the ubiquitin-proteasome system, mediating the degradation of multiple oncogenic proteins, including c-MYC, Cyclin E, c-Jun, Notch, p53. Around 16% of colorectal cancer (CRC) patients carried FBXW7 somatic mutations, while a comprehensive characterization of FBXW7 somatic mutations in CRC is still lacking.

Methods

Colorectal cancer patients with tumor samples and matching white blood cell samples in the past five years were screened and DNA sequenced. DNA sequencing data of MSK MetTropism cohort and RNA sequencing data of TCGA COAD cohort were analyzed.

Results

We discovered that the FBXW7 mutations were associated with higher tumor mutation burden (TMB), higher microsatellite instability (MSI) score, and lower chromosomal instability (CIN) score. Patients with FBXW7 mutations showed better overall survival (HR: 0.67; 95%CI: 0.55-0.80, P &lt; 0.001). However, patients with FBXW7 R465C mutation displayed worse overall survival in multi-variate cox analysis when compared with patients carrying other FBXW7 mutations (HR: 1.6; 95%CI: 1.13-3.1, P = 0.015), and with all other patients (HR: 1.87; 95%CI: 0.99-2.5, P = 0.053). Moreover, in MSI patients, the FBXW7 mutated group showed higher M1 macrophage, CD8+ T cell, and regulatory T cell (Tregs) infiltration rates, and significant enrichment of multiple immune-related gene sets, including interferon-gamma response, interferon-alpha response, IL6 JAK STAT3 signaling, p53 pathway.

Conclusion

This analysis comprehensively identified FBXW7 alterations in colorectal cancer patients and uncovered the molecular, clinicopathological, and immune-related patterns of FBXW7-altered CRC patients.

FBXW7 tumor suppressor regulation by dualspecificity tyrosine-regulated kinase 2

FBXW7 is a member of the F-box protein family, which functions as the substrate recognition component of the SCF E3 ubiquitin ligase. FBXW7 is a main tumor suppressor due to its ability to control proteasome-mediated degradation of several oncoproteins such as c-Jun, c-Myc, Cyclin E1, mTOR, and Notch1-IC. FBXW7 inactivation in human cancers results from a somatic mutation or downregulation of its protein levels. This work describes a novel regulatory mechanism for FBXW7 dependent on the serine/threonine protein kinase DYRK2. We show that DYRK2 interacts with and phosphorylates FBXW7 resulting in its proteasome-mediated degradation. DYRK2-dependent FBXW7 destabilization is independent of its ubiquitin ligase activity. The functional analysis demonstrates the existence of DYRK2-dependent regulatory mechanisms for key FBXW7 substrates. Finally, we provide evidence indicating that DYRK2-dependent regulation of FBXW7 protein accumulation contributes to cytotoxic effects in response to chemotherapy agents such as Doxorubicin or Paclitaxel in colorectal cancer cell lines and to BET inhibitors in T-cell acute lymphoblastic leukemia cell lines. Altogether, this work reveals a new regulatory axis, DYRK2/FBXW7, which provides an understanding of the role of these two proteins in tumor progression and DNA damage responses.

FBXO30 functions as a tumor suppressor and an E3 ubiquitin ligase for hZIP1‑mediated HIF‑1α degradation in renal cell carcinoma

Studies on clear cell renal cell carcinoma (ccRCC) are gaining momentum due to its high malignancy and potential to metastasize. F‑box protein 30 (FBXO30) is a member of the F‑box protein family; however, its role and mechanism in cancer remains to be fully elucidated. Western blotting, reverse transcription‑quantitative PCR and immunohistochemsitry were performed to detect the expression levels of FBXO30 in ccRCC tissues and adjacent normal tissues. Tumor biological function assays and animal experiments were conducted to clarify the inhibitory effect of FBXO30 on the progression and metastasis of ccRCC. Protein half‑life assay, MG132 inhibition assay, immunofluorescence assay and co‑immunoprecipitation assay were performed to explore the ubiquitination mechanism of FBXO30 and HIF‑1α. Zinc supplementation assay was used to verify the regulatory relationship between human ZRT, IRT‑like protein 1 (hZIP1), FBXO30 and HIF‑1α. The present study revealed that the expression levels of FBXO30 were lower in ccRCC tissues compared with those in normal adjacent tissues. In addition, FBXO30 inhibited the tumorigenesis and metastatic capacity of ccRCC cells in vivo and in vitro. FBXO30 mediated the ubiquitination and degradation of hypoxia‑inducible factor‑1α (HIF‑1α) in ccRCC cells under normoxia, thereby inhibiting the oncogenic effect of HIF‑1α. Notably, hZIP1 served as an upstream regulator of FBXO30, regulating the expression of FBXO30 and HIF‑1α by recruiting Zn²⁺. In conclusion, the present data suggested that FBXO30 is a novel E3 ubiquitination ligase that can function as a tumor suppressor in ccRCC, and the hZIP1/Zn²⁺/FBXO30/HIF‑1α axis may provide potential biomarkers or therapeutic targets for ccRCC.

Circular RNAs: New players involved in the regulation of cognition and cognitive diseases

Circular RNAs (circRNAs), a type of covalently closed endogenous single-stranded RNA, have been regarded as the byproducts of the aberrant splicing of genes without any biological functions. Recently, with the development of high-throughput sequencing and bioinformatics, thousands of circRNAs and their differential biological functions have been identified. Except for the great advances in identifying circRNA roles in tumor progression, diagnosis, and treatment, accumulated evidence shows that circRNAs are enriched in the brain, especially in the synapse, and dynamically change with the development or aging of organisms. Because of the specific roles of synapses in higher-order cognitive functions, circRNAs may not only participate in cognitive functions in normal physiological conditions but also lead to cognition-related diseases after abnormal regulation of their expression or location. Thus, in this review, we summarized the progress of studies looking at the role of circRNA in cognitive function, as well as their involvement in the occurrence, development, prognosis, and treatment of cognitive-related diseases, including autism, depression, and Alzheimer's diseases.

FBXO9 Mediates the Cancer-Promoting Effects of ZNF143 by Degrading FBXW7 and Facilitates Drug Resistance in Hepatocellular Carcinoma

F-box proteins are critical for malignancy because they control the turnover of key proteins that govern multiple cellular processes. F-box protein 9 (FBXO9) belongs to the F-box protein family and exhibits oncogenic properties in hematological malignancies. However, the function and molecular mechanism of FBXO9 in hepatocellular carcinoma (HCC) remain unclear. Here, we report that FBXO9 was remarkably overexpressed in HCC. Loss- and gain-of-function experiments showed that FBXO9 facilitates HCC cell proliferation and metastasis both in vitro and in vivo. Mechanistically, as a direct upstream transcription factor, FBXO9 is regulated by zinc finger protein 143 (ZNF143) and accelerates tumor growth and metastasis by targeting the F-box and WD repeat domain containing 7 (FBXW7) for ubiquitination and degradation. Additionally, we found that with FBXO9 knockdown, HCC cells were more sensitive to treatment with lenvatinib and sorafenib. In summary, our results demonstrate that a ZNF143-FBXO9-FBXW7 signaling regulatory axis may be involved in tumor progression in HCC, and suggest that FBXO9 could be a potential biomarker and therapeutic target for HCC.