A novel HIF1α-STIL-FOXM1 axis regulates tumor metastasis

Mechanosensitive Ion Channel PIEZO1 as a Key Regulator of Intestinal Fibrosis in Crohn's Disease

BACKGROUND

We aimed to elucidate the function of the mechanosensitive ion channel PIEZO1 in intestinal fibrosis, which is invariably associated with Crohn's disease (CD) and often results in strictures and obstructions, requiring surgical intervention. Notably, PIEZO1 is strongly expressed in fibrotic tissues and linked with fibrotic progression.

METHODS

Intestinal tissues were procured from 28 patients diagnosed with CD and 8 healthy control subjects. Histological and immunofluorescence assays verified that PIEZO1 is substantially overexpressed in fibrotic intestinal tissues and is involved in epithelial‒mesenchymal transition (EMT). Further gene knockout experiments and transcriptome sequencing elucidated the specific role of PIEZO1 in the pathogenesis of intestinal fibrosis in CD. We generated mice with Piezo1 deletion specifically in intestinal epithelial cells (Piezo1f/f  Vilcre) to validate in vivo that inhibiting Piezo1 function attenuates or reverses intestinal fibrosis associated with CD.

RESULTS

PIEZO1 expression was strongly increased in the fibrotic small intestine of CD patients, thereby promoting EMT and exacerbating intestinal fibrosis. In vivo investigations revealed that the conditional suppression of Piezo1 in intestinal epithelial cells significantly mitigated intestinal fibrosis in dextran sulphate sodium (DSS)- and 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced chronic colitis model mice. In vitro examinations revealed that Piezo1 expression in intestinal epithelial cells preserved the stability of HIF-1α, induced EMT to stimulate the expression of fibrosis-associated molecules, and promoted fibrosis.

CONCLUSION

PIEZO1 plays a pivotal role in the regulation of intestinal fibrosis by maintaining the levels of HIF-1α, thereby promoting EMT. Therapeutic strategies targeting PIEZO1 could be used to prevent intestinal fibrosis in CD patients.

Interaction of STIL with FOXM1 regulates SF3A3 transcription in the hepatocellular carcinoma development

BACKGROUND

Dysregulation of SF3A3 has been related to the development of many cancers. Here, we investigated the functional role of SF3A3 in hepatocellular carcinoma (HCC).

METHODS

SF3A3 expression in HCC tissues and cell lines was examined using RT-qPCR. Changes in malignant behavior of HCC cells after downregulation of SF3A3 were assessed by EdU, colony formation, flow cytometry, wound healing, and Transwell invasion assays. Multiple datasets were combined to identify the upstream modifiers of SF3A3. The binding relationship between STIL and FOXM1 was explored by co-IP assay, and the effect of STIL and FOXM1 on the binding of FOXM1 at the SF3A3 promoter was detected by ChIP-qPCR assay. A xenograft tumor model was established to explore the changes of tumors in vivo, and the expression of Ki67, GPC3, and p53 in tumor tissues was detected by immunohistochemistry.

RESULTS

SF3A3 and STIL were overexpressed in HCC tissues and cells, and downregulation of SF3A3 or STIL inhibited the malignant behavior of HCC cells by promoting the expression of p53. An interaction between STIL and FOXM1 regulated the SF3A3 expression in HCC cells. Knockdown of FOXM1 further enhanced the anti-tumor effects of STIL loss on HCC cells in vitro and in vivo, whereas SF3A3 overexpression overturned the impact of STIL loss on HCC cells in vitro and in vivo.

CONCLUSIONS

Our findings indicate that STIL/FOXM1 expedites HCC development by activating SF3A3, which highlights the importance of SF3A3 as a promising prognostic marker and therapeutic target for HCC.

Regulatory factor X-5/SCL/TAL1 interruption site axis promotes aerobic glycolysis and hepatocellular carcinoma cell stemness

The incidence and development of various tumors, such as hepatocellular carcinoma (HCC), are linked to tumor stem cells. Although research has revealed how important SCL/TAL1 interruption site (STIL) is in many human tumors, the impact of STIL on HCC stem cells is poorly understood. This study aimed to examine the regulatory mechanisms and the function of STIL in the stemness of HCC tumor cells. Bioinformatics analysis was applied to determine the STIL and regulatory factor X-5 (RFX5) expression in HCC tissues. Immunohistochemistry (IHC) was used to detect the expression of STIL and RFX5 in HCC tissues. Quantitative real-time polymerase chain reaction was utilized to measure the STIL and RFX5 expression levels in HCC cells. The viability of the cells was assessed by the Cell Counting Kit-8 assay. The sphere formation assay was used to evaluate the sphere-forming capacity. The expression levels of the stem cell markers SOX2, Oct-4, CD133, CD44, the glycolysis-related proteins LDHA, HK2, AKT, p-AKT, and β-catenin were assessed by Western blot. Lactate production, oxygen consumption rate, and extracellular acidification rate were measured to assess the glycolytic capacity of HCC cells. Chromatin immunoprecipitation and dual-luciferase experiments were performed to validate the connection between RFX5 and STIL. Bioinformatics analysis determined that STIL exhibited high expression in HCC tissues and was enriched in the glycolysis pathway. In addition, the expression of glycolysis marker genes was positively correlated with STIL expression. Cell experiments verified that the activation of the glycolysis pathway by overexpression of STIL promoted stemness in HCC. Molecular experiments also revealed the binding relationship between STIL and RFX5. IHC detected high expression of STIL and RFX5 in HCC tissues. Cell functional experiments revealed that RFX5 could influence the HCC cells stemness by activating the STIL transcription via the glycolysis pathway. This study identified a novel role for the RFX5/STIL axis in HCC progression, which may offer treatment targets for HCC.

STIL Overexpression Is Associated with Chromosomal Numerical Abnormalities in Non-Small-Cell Lung Carcinoma Through Centrosome Amplification

STIL is a regulatory protein essential for centriole biogenesis, and its dysregulation has been implicated in various diseases, including malignancies. However, its role in non-small-cell lung carcinoma (NSCLC) remains unclear. In this study, we examined STIL expression and its potential association with chromosomal numerical abnormalities (CNAs) in NSCLC using The Cancer Genome Atlas (TCGA) dataset, immunohistochemical analysis, and in vitro experiments with NSCLC cell lines designed to overexpress STIL. TCGA data revealed upregulated STIL mRNA expression in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), the two major subtypes of NSCLC. Immunohistochemical analysis of cases from our hospital (LUAD, n = 268; LUSC, n = 98) revealed STIL protein overexpression. To elucidate the functional role of STIL, an inducible STIL-overexpressing H1299 NSCLC cell line was generated. Overexpression of STIL in these cells promoted centrosome amplification, leading to chromosomal instability. Finally, analysis of arm-level chromosomal copy number alterations from the TCGA dataset revealed that elevated STIL mRNA expression was associated with CNAs in both LUAD and LUSC. These findings suggest that STIL overexpression is associated with CNAs in NSCLC, likely through centrosome amplification, which is linked to chromosomal instability and might represent a potential therapeutic target for NSCLC treatment.

Development of a novel centrosome-related risk signature to predict prognosis and treatment response in lung adenocarcinoma

BACKGROUND

Abnormalities of centrosomes, the major microtubular organizing centers of animal cells and regulators of cell cycle progression, usually accelerate tumor progression, but their prognostic value in lung adenocarcinoma (LUAD) remains insufficiently explored.

METHODS

We collected centrosome genes from the literature and identified LUAD-specific centrosome-related genes (CRGs) using the single-sample gene set enrichment analysis (ssGSEA) algorithm and weighted gene co-expression network analysis (WGCNA). Univariate Cox was performed to screen prognostic CRGs. Consistent clustering was performed to classify LUAD patients into two subgroups, and centrosome-related risk score signatures were constructed by Lasso and multivariate Cox regression to predict overall survival (OS). We further explored the correlation between CRS and patient prognosis, clinical manifestations, mutation status, tumor microenvironment, and response to different treatments.

RESULTS

We constructed centrosome-associated prognostic features and verified that CRS could effectively predict 1-, 3-, and 5-year survival in LUAD patients. In addition, patients in the high-risk group exhibited elevated tumor mutational loads and reduced levels of immune infiltration, particularly of T and B cells. Patients in the high-risk group were resistant to immunotherapy and sensitive to 5-fluoropyrimidine and gefitinib. The key gene spermine synthase (SRM) is highly expressed at the mRNA and protein levels in LUAD.

DISCUSSION

Our work develops a novel centrosome-related prognostic signature that accurately predicts OS in LUAD and can assist in clinical diagnosis and treatment.

STIL overexpression shortens lifespan and reduces tumor formation in mice

Centrosomes are the major microtubule organizing centers of animal cells. Supernumerary centrosomes are a common feature of human tumors and associated with karyotype abnormalities and aggressive disease, but whether they are cause or consequence of cancer remains controversial. Here, we analyzed the consequences of centrosome amplification by generating transgenic mice in which centrosome numbers can be increased by overexpression of the structural centrosome protein STIL. We show that STIL overexpression induces centrosome amplification and aneuploidy, leading to senescence, apoptosis, and impaired proliferation in mouse embryonic fibroblasts, and microcephaly with increased perinatal lethality and shortened lifespan in mice. Importantly, both overall tumor formation in mice with constitutive, global STIL overexpression and chemical skin carcinogenesis in animals with inducible, skin-specific STIL overexpression were reduced, an effect that was not rescued by concomitant interference with p53 function. These results suggest that supernumerary centrosomes impair proliferation in vitro as well as in vivo, resulting in reduced lifespan and delayed spontaneous as well as carcinogen-induced tumor formation.

FOXM1a Isoform of Oncogene FOXM1 Is a Tumor Suppressor Suppressed by hnRNP C in Oral Squamous Cell Carcinoma

FOXM1 is an oncogenic transcriptional factor and includes several isoforms generated by alternative splicing. Inclusion of alternative exon 9 produces FOXM1a, a transcriptionally inactive isoform. However, the role of FOXM1a in tumorigenesis remains unknown. In addition, the regulatory mechanisms of exon 9 splicing are also unclear. In the present study, we found that overexpression of FOXM1a significantly reduced cell proliferation and colony formation of oral squamous cell carcinoma (OSCC) cell proliferation in vitro. Importantly, OSCC cells with FOXM1a overexpression showed significantly slower tumor formation in nude mice. Moreover, we identified a U-rich exonic splicing suppressor (ESS) which is responsible for exon 9 skipping. Splicing factor heterogeneous nuclear ribonucleoprotein C (hnRNP C) can bind to the ESS and suppress exon 9 inclusion and FOXM1a expression. Silence of hnRNP C also significantly suppresses OSCC cell proliferation. HnRNP C is significantly co-expressed with FOXM1 in cancers. Our study uncovered a novel regulatory mechanism of oncogene FOXM1 expression in OSCC.

FOXM1: A small fox that makes more tracks for cancer progression and metastasis

Transcription factors (TFs) are indispensable for the modulation of various signaling pathways associated with normal cell homeostasis and disease conditions. Among cancer-related TFs, FOXM1 is a critical molecule that regulates multiple aspects of cancer cells, including growth, metastasis, recurrence, and stem cell features. FOXM1 also impact the outcomes of targeted therapies, chemotherapies, and immune checkpoint inhibitors (ICIs) in various cancer types. Recent advances in cancer research strengthen the cancer-specific role of FOXM1, providing a rationale to target FOXM1 for developing targeted therapies. This review compiles the recent studies describing the pivotal role of FOXM1 in promoting metastasis of various cancer types. It also implicates the contribution of FOXM1 in the modulation of chemotherapeutic resistance, antitumor immune response/immunotherapies, and the potential of small molecule inhibitors of FOXM1.

Transcriptome Sequencing Reveals Autophagy Networks in Rat Livers during the Development of NAFLD and Identifies Autophagy Hub Genes

(1) Autophagy is an important biological process in cells and is closely associated with the development and progression of non-alcoholic fatty liver disease (NAFLD). Therefore, this study aims to investigate the biological function of the autophagy hub genes, which could be used as a potential therapeutic target and diagnostic markers for NAFLD. (2) Male C57BL/6J mice were sacrificed after 16 and 38 weeks of a high-fat diet, serum biochemical indexes were detected, and liver lobules were collected for pathological observation and transcriptome sequencing. The R software was used to identify differentially expressed autophagy genes (DEGs) from the transcriptome sequencing data of mice fed with a normal diet for 38 weeks (ND38) and a high-fat diet for 38 weeks (HFD38). Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on the DEGs, a protein-protein interaction (PPI) network of the DEGs was established using the STRING data website, and the results were visualized through Cytoscape. (3) After 16 weeks and 38 weeks of a high-fat diet, there was a significant increase in body weight, serum total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and triglycerides (TG) in mice, along with lipid accumulation in the liver, which was more severe at 38 weeks than at 16 weeks. The transcriptome data showed significant changes in the expression profile of autophagy genes in the livers of NAFLD mice following a long-term high-fat diet. Among the 31 differentially expressed autophagy-related genes, 13 were upregulated and 18 were downregulated. GO and KEGG pathway analysis revealed that these DEGs were primarily involved in autophagy, cholesterol transport, triglyceride metabolism, apoptosis, the FoxO signaling pathway, the p53 signaling pathway and the IL-17 signaling pathway. Four hub genes were identified by the PPI network analysis, of which Irs2, Pnpla2 and Plin2 were significantly downregulated, while Srebf2 was significantly upregulated by the 38-week high-fat diet. (4) The hub genes Irs2, Pnpla2, Srebf2 and Plin2 may serve as key therapeutic targets and early diagnostic markers in the progression of NAFLD.

Multi-omics characterization of a scoring system to quantify hypoxia patterns in patients with head and neck squamous cell carcinoma

BACKGROUND

The 5-year survival rate of patients with head and neck squamous cell carcinoma (HNSCC) remains  < 50%. Hypoxia patterns are a hallmark of HNSCC that are associated with its occurrence and progression. However, the precise role of hypoxia during HNSCC, such as the relationship between hypoxia, tumor immune landscape and cell communication orchestration remains largely unknown. The current study integrated data from bulk and single-cell RNA sequencing analyses to define the relationship between hypoxia and HNSCC.

METHODS

A scoring system named the hypoxia score (HS) was constructed based on hypoxia-related genes (HRGs) expression. The predictive value of HS response for patient outcomes and different treatments was evaluated. Single-cell datasets and cell communication were utilized to rule out cell populations which hypoxia targeted on.

RESULTS

The survival outcomes, immune/Estimate scores, responses to targeted inhibitors, and chemotherapeutic, and immunotherapy responses were distinct between a high HS group and a low HS group (all P < 0.05). Single-cell datasets showed different distributions of HS in immune cell populations (P < 0.05). Furthermore, HLA-DPA1/CD4 axis was identified as a unique interaction between CD4 + T Conv and pDC cells.

CONCLUSIONS

Altogether, the quantification for hypoxia patterns is a potential biomarker for prognosis, individualized chemotherapeutic and immunotherapy strategies. The portrait of cell communication characteristics over the HNSCC ecosystem enhances the understanding of hypoxia patterns in HNSCC.