RAF1 gene fusions are recurrent driver events in infantile fibrosarcoma-like mesenchymal tumors.

Infantile fibrosarcomas (IFS) and congenital mesoblastic nephroma (CMN) are rare myofibroblastic tumors of infancy and early childhood commonly harboring the ETV6::NTRK3 gene fusion. IFS/CMN are considered as tumors with an 'intermediate prognosis' as they are locally aggressive, but rarely metastasize, and generally have a favorable outcome. A fraction of IFS/CMN-related neoplasms are negative for the ETV6::NTRK3 gene rearrangement and are characterized by other chimeric proteins promoting MAPK signaling upregulation. In a large proportion of these tumors, which are classified as IFS-like mesenchymal neoplasms, the contributing molecular events remain to be identified. Here, we report three distinct rearrangements involving RAF1 among eight ETV6::NTRK3 gene fusion-negative tumors with an original histological diagnosis of IFS/CMN. The three fusion proteins retain the entire catalytic domain of the kinase. Two chimeric products, GOLGA4::RAF1 and LRRFIP2::RAF1, had previously been reported as driver events in different cancers, whereas the third, CLIP1::RAF1, represents a novel fusion protein. We demonstrate that CLIP1::RAF1 acts as a bona fide oncoprotein promoting cell proliferation and migration through constitutive upregulation of MAPK signaling. We show that the CLIP1::RAF1 hyperactive behavior does not require RAS activation and is mediated by constitutive 14-3-3 protein-independent dimerization of the chimeric protein. As previously reported for the ETV6::NTRK3 fusion protein, CLIP1::RAF1 similarly upregulates PI3K-AKT signaling. Our findings document that RAF1 gene rearrangements represent a recurrent event in ETV6::NTRK3-negative IFS/CMN and provide a rationale for the use of inhibitors directed to suppress MAPK and PI3K-AKT signaling in these cancers. © 2024 The Pathological Society of Great Britain and Ireland.

Seihaito, a Kampo medicine, attenuates IL-13-induced mucus production and goblet cell metaplasia.

Goblet cell hyperplasia and increased mucus production are features of airway diseases, including asthma, and excess airway mucus often worsens these conditions. Even steroids are not uniformly effective in mucus production in severe asthma, and new therapeutic options are needed. Seihaito is a Japanese traditional medicine that is used clinically as an antitussive and expectorant. In the present study, we examined the effect of Seihaito on goblet cell differentiation and mucus production. In in vitro studies, using air-liquid interface culture of guinea-pig tracheal epithelial cells, Seihaito inhibited IL-13-induced proliferation of goblet cells and MUC5AC, a major component of mucus production. Seihaito suppressed goblet cell-specific gene expression, without changing ciliary cell-specific genes, suggesting that it inhibits goblet cell differentiation. In addition, Seihaito suppressed MUC5AC expression in cells transfected with SPDEF, a transcription factor activated by IL-13. Furthermore, Seihaito attenuated in vivo goblet cell proliferation and MUC5AC mRNA expression in IL-13-treated mouse lungs. Collectively, these findings demonstrated that Seihaito has an inhibitory effect on goblet cell differentiation and mucus production, which is at least partly due to the inhibition of SPDEF.

The function of the ELF3 gene and its mechanism in cancers.

E74-like factor 3 (ELF3) is an important member of the E-twenty-six (ETS) transcription factor family. ELF3 is expressed in various types of cells and regulates a variety of biological behaviors, such as cell proliferation, differentiation, apoptosis, migration, and invasion, by binding to DNA to regulate the expression of other genes. In recent years, studies have shown that ELF3 plays an important role in the occurrence and development of many tumors and inflammation and immune related diseases. ELF3 has different functions and expression patterns in different tumors; it can function as a tumor suppressor gene or an oncogene, highlighting its dual effects of tumor promotion and inhibition. ELF3 also affects the levels of tumor immunity-related cytokines and is involved in the regulation and expression of multiple signaling pathways. In tumor therapy, ELF3 is a complex and multifunctional gene and has become a key focus of targeted treatment research. An in-depth study of the biological function of ELF3 can help to elucidate its role in biological processes and provide ideas and a basis for the development and clinical application of ELF3-related therapeutic methods. This review introduces the structure and physiological and cellular functions of the ELF3 gene, summarizes the mechanisms of action of ELF3 in different types of malignant tumors and its role in immune regulation, inflammation, etc., and discusses treatment methods for ELF3-related diseases, providing significant reference value for scholars studying the ELF3 gene and related diseases.

Predictors of radioiodine (RAI)-avidity restoration for NTRK fusion-positive RAI-resistant metastatic thyroid cancers.

Context: Two-thirds of metastatic differentiated thyroid cancer (DTC) patients have radioiodine (RAI)-resistant disease, resulting in poor prognosis and high mortality. For rare NTRK and RET fusion-positive metastatic, RAI-resistant thyroid cancers, variable success of re-induction of RAI avidity during treatment with NTRK or RET inhibitors has been reported. Case presentation and results: We report two cases with RAI-resistant lung metastases treated with larotrectinib: an 83-year-old male presenting with an ETV6::NTRK3 fusion-positive tumor with the TERT promoter mutation c.-124C>T, and a 31-year-old female presenting with a TPR::NTRK1 fusion-positive tumor (and negative for TERT promoter mutation). Post larotrectinib treatment, diagnostic I-123 whole body scan revealed unsuccessful RAI-uptake re-induction in the TERT-positive tumor, with a thyroid differentiation score (TDS) of -0.287. In contrast, the TERT-negative tumor exhibited successful I-131 reuptake with a TDS of -0.060. Conclusion: As observed for RAI-resistance associated with concurrent TERT and BRAF mutations, the co-occurrence of TERT mutations and NTRK fusions may also contribute to re-sensitization failure.

Characteristics and literature review of ETV6::ABL1 fusion gene-positive acute myeloid leukemia.

OBJECTIVE: To describe the features of ETV6::ABL1 AML as well as the clinical treatment and outcomes. METHODS: Clinical data were collected from three patients diagnosed with ETV6::ABL1 AML at Hebei Yanda Lu Daopei Hospital and Beijing Lu Daopei Hospital. Their clinical and laboratory features were analyzed, and the treatment process and outcomes were described. Ten reported cases of ETV6::ABL1 AML from the literature were also included for analysis. RESULTS: The median age of the patients was 34 years, and 2 patients were male. No patient had a history of blood disorders before diagnosis. After relapse, they were referred to our hospital, where the ETV6::ABL1 gene was detected. Unfortunately, Patient 1 died rapidly after leukemia relapse due to severe infection. Patients 2 and 3 received salvage therapy with a dasatinib-containing regimen, followed by allo-HSCT, and are currently alive and disease-free. CONCLUSION: ETV6::ABL1 is a rare but recurrent genetic aberration in AML, and the combined use of fluorescence in situ hybridization and PCR can better identify this fusion gene. Patients carrying ETV6::ABL1 have a high relapse rate and a poor prognosis. TKIs are a reasonable treatment option for this group, and allo-HSCT may be curative.

ETS transcription factors regulate precise matrix metalloproteinase expression and follicle rupture in Drosophila.

Drosophila matrix metalloproteinase 2 (MMP2) is specifically expressed in posterior follicle cells of stage-14 egg chambers (mature follicles) and is crucial for the breakdown of the follicular wall during ovulation, a process that is highly conserved from flies to mammals. The factors that regulate spatiotemporal expression of MMP2 in follicle cells remain unknown. Here, we demonstrate crucial roles for the ETS-family transcriptional activator Pointed (Pnt) and its endogenous repressor Yan in the regulation of MMP2 expression. We found that Pnt is expressed in posterior follicle cells and overlaps with MMP2 expression in mature follicles. Genetic analysis demonstrated that pnt is both required and sufficient for MMP2 expression in follicle cells. In addition, Yan was temporally upregulated in stage-13 follicle cells to fine-tune Pnt activity and MMP2 expression. Furthermore, we identified a 1.1 kb core enhancer that is responsible for the spatiotemporal expression of MMP2 and contains multiple pnt/yan binding motifs. Mutation of pnt/yan binding sites significantly impaired the Mmp2 enhancer activity. Our data reveal a mechanism of transcriptional regulation of Mmp2 expression in Drosophila ovulation, which could be conserved in other biological systems.

Exosomal miR-361-3p promotes the viability of breast cancer cells by targeting ETV7 and BATF2 to upregulate the PAI-1/ERK pathway.

BACKGROUND: Malignant progression is the major cause of poor prognosis in breast cancer (BC) patients. Plasma exosomal miRNAs have been reported to be involved in tumor progression, but their roles in BC remain unclear. METHODS: We performed plasma exosomal miRNA sequencing on 45 individuals, including healthy controls and nonmetastatic and metastatic BC patients. We examined the correlation between miRNA expression in tumor tissues and plasma exosomes in BC patients by qRT‒PCR. The effects of exosomal miR-361-3p on BC cells were determined by CellTiter-Glo, migration and wound healing assays. The target genes of miR-361-3p and downstream pathways were explored by dual-luciferase reporter assay, RNA knockdown, rescue experiments, and western blotting. We utilized murine xenograft model to further assess the impact of plasma exosomal miR-361-3p on the malignant progression of BC. RESULTS: We found that the expression level of plasma exosomal miR-361-3p gradually increased with malignant progression in BC patients, and the expression of miR-361-3p in plasma exosomes and BC tissues was positively correlated. Consistently, exosomal miR-361-3p enhanced the migration and proliferation of two BC cell lines, MDA-MB-231 and SK-BR-3. Furthermore, our data showed that miR-361-3p inhibited two novel target genes, ETV7 and BATF2, to activate the PAI-1/ERK pathway, leading to increased BC cell viability. Finally, the consistency of the in vivo experimental results supported that elevated plasma exosomal miR-361-3p promote the malignant progression of BC. CONCLUSIONS: We found for the first time that plasma exosomal miR-361-3p was associated with malignant progression in BC patients. Mechanistically, exosomal miR-361-3p can enhance the migration and proliferation of BC cells by targeting the ETV7 and BATF2/PAI-1/ERK pathways. Our data suggest that plasma exosomal miR-361-3p has the potential to serve as a biomarker for predicting malignant progression in BC patients.

Huaier suppresses cell viability, migration and invasion in human non-small cell lung cancer via lncRNA DLEU2/miR-212-5p/ELF3 axis.

Accumulating studies suggest that Huaier exerts anti-tumor effects through intricate mechanisms. Despite extensive research on its efficacy in lung cancer, further investigation is required to elucidate the molecular mechanism of Huaier. The involvement of long noncoding RNAs (lncRNAs) in the anti-lung cancer effects of Huaier remains unknown. In this study, we found Huaier suppressed cell viability, migration and invasion in non-small cell lung cancer (NSCLC) cells. LncRNA sequencing analysis revealed Deleted in lymphocytic leukemia 2 (DLEU2) to be significantly downregulated in Huaier-treated NSCLC cells. Furthermore, DLEU2 silencing was observed to suppress NSCLC progression, while DLEU2 overexpression attenuated the anti-tumor effects of Huaier in NSCLC, thereby promoting cell viability, migration and invasion of NSCLC. The ceRNA role of DLEU2 had been demonstrated in NSCLC, which directly interacted with miR-212-5p to rescue the repression of E74 Like ETS Transcription Factor 3 (ELF3) by this microRNA. Additionally, Huaier was found to regulate the expression of miR-212-5p and ELF3. Functionally, miR-212-5p inhibitor or ELF3 overexpression reversed the effects of DLEU2 silencing or Huaier treatment, resulting in increased colony formation, migration and invasion in NSCLC. Taken together, these results illuminate the mechanism underlying Huaier's anti-tumor effects via the DLEU2/miR-212-5p/ELF3 signaling pathway, which offers novel insights into the anti-tumor effects of Huaier and constitutes a promising therapeutic target for the treatment in NSCLC.

ETV4-Dependent Transcriptional Plasticity Maintains MYC Expression and Results in IMiD Resistance in Multiple Myeloma.

Immunomodulatory drugs (IMiD) are a backbone therapy for multiple myeloma (MM). Despite their efficacy, most patients develop resistance, and the mechanisms are not fully defined. Here, we show that IMiD responses are directed by IMiD-dependent degradation of IKZF1 and IKZF3 that bind to enhancers necessary to sustain the expression of MYC and other myeloma oncogenes. IMiD treatment universally depleted chromatin-bound IKZF1, but eviction of P300 and BRD4 coactivators only occurred in IMiD-sensitive cells. IKZF1-bound enhancers overlapped other transcription factor binding motifs, including ETV4. Chromatin immunoprecipitation sequencing showed that ETV4 bound to the same enhancers as IKZF1, and ETV4 CRISPR/Cas9-mediated ablation resulted in sensitization of IMiD-resistant MM. ETV4 expression is associated with IMiD resistance in cell lines, poor prognosis in patients, and is upregulated at relapse. These data indicate that ETV4 alleviates IKZF1 and IKZF3 dependency in MM by maintaining oncogenic enhancer activity and identify transcriptional plasticity as a previously unrecognized mechanism of IMiD resistance. SIGNIFICANCE: We show that IKZF1-bound enhancers are critical for IMiD efficacy and that the factor ETV4 can bind the same enhancers and substitute for IKZF1 and mediate IMiD resistance by maintaining MYC and other oncogenes. These data implicate transcription factor redundancy as a previously unrecognized mode of IMiD resistance in MM. See related article by Welsh, Barwick, et al., p. 34. See related commentary by Yun and Cleveland, p. 5. This article is featured in Selected Articles from This Issue, p. 4.

Genome-wide identification and characteristic analysis of ETS gene family in blood clam Tegillarca granosa.

BACKGROUND: ETS transcription factors, known as the E26 transformation-specific factors, assume a critical role in the regulation of various vital biological processes in animals, including cell differentiation, the cell cycle, and cell apoptosis. However, their characterization in mollusks is currently lacking. RESULTS: The current study focused on a comprehensive analysis of the ETS genes in blood clam Tegillarca granosa and other mollusk genomes. Our phylogenetic analysis revealed the absence of the SPI and ETV subfamilies in mollusks compared to humans. Additionally, several ETS genes in mollusks were found to lack the PNT domain, potentially resulting in a diminished ability of ETS proteins to bind target genes. Interestingly, the bivalve ETS1 genes exhibited significantly high expression levels during the multicellular proliferation stage and in gill tissues. Furthermore, qRT-PCR results showed that Tg-ETS-14 (ETS1) is upregulated in the high total hemocyte counts (THC) population of T. granosa, suggesting it plays a significant role in stimulating hemocyte proliferation. CONCLUSION: Our study significantly contributes to the comprehension of the evolutionary aspects concerning the ETS gene family, while also providing valuable insights into its role in fostering hemocyte proliferation across mollusks.

Regulation of SPDEF expression by DNA methylation in advanced prostate cancer.

Introduction: Prostate cancer (PCa) presents a significant health challenge in men, with a substantial number of deaths attributed to metastatic castration resistant PCa (mCRPC). Moreover, African American men experience disproportionately high mortality rates due to PCa. This study delves into the pivotal role of SPDEF, a prostate specific Ets transcription factor, and its regulation by DNA methylation in the context of PCa progression. Methods: We performed Epigenetic reprogramming using daily treatment with non-toxic dose of 5Aza-2-deoxycytidine (5Aza-dC) for two weeks to assess its impact on PDEF expression in prostate cancer cells. Next, we conducted functional studies on reprogrammed cells, including cell migration (wound-healing assay), invasion (Boyden-Chamber test), and proliferation (MTT assay) to comprehensively evaluate the consequences of altered PDEF expression. We used bisulfite sequencing (BSP) to examine DNA methylation at SPDEF promoter. Simultaneously, we utilized siRNA-mediated targeting of key DNMTs (DNMT1, DNMT3A, and DNMT3B) to elucidate their specific role in regulating PDEF. We measured mRNA and protein expressions using qRT-PCR and immune-blotting techniques, respectively. Results: In this report, we observed that: a) there is a gradual decrease in SPDEF expression with a concomitant increase in methylated CpG sites within the SPDEF gene during prostate cancer progression from lower to higher Gleason grade; b) Expression of DNMT's (DNMT1, 3a and 3b) is increased during prostate cancer progression, and there is an inverse correlation between SPDEF and DNMT expression; c) SPDEF levels are decreased in RC77/T, a line of PCa cells from African American origin similar to PC3 and DU145 cells (CRPC cells), as compared to LNCaP cells , a line of androgen dependent cells,; d) the 5' CpG island of SPDEF gene are hypermethylated in SPDEF-negative CRPC ( PC3, DU145 and RC77/T) cell lines but the same regions are hypomethylated in SPDEF-positive castrate sensitive (LNCaP) cell line ; (e) expression of SPDEF in PCa cells lacking SPDEF decreases cell migration and invasion, but has no significant effect on cell proliferation, and; (f) treatment with the demethylating agent, 5-aza-2'-deoxycytidine, or silencing of the DNMT's by siRNA, partially restores SPDEF expression in SPDEF-negative PCa cell lines, and decreases cell migration and invasion. Discussion: These results indicate hypermethylation is a prevalent mechanism for decreasing SPDEF expression during prostate cancer progression. The data demonstrate that loss of SPDEF expression in prostate cancer cells, a critical step in cellular plasticity, results from a potentially reversible process of aberrant DNA methylation. These studies suggest DMNT activity as a potential therapeutic vulnerability that can be exploited for limiting cellular plasticity, tumor progression, and therapy resistance in prostate cancer.

ETV4 facilitates angiogenesis in hepatocellular carcinoma by upregulating MMP14 expression.

Abnormal vascularization plays a crucial role in cell proliferation, tumor invasion and metastasis of hepatocellular carcinoma (HCC). It has been reported that ETV4 functions as an oncogenic gene in driving the carcinogenesis and progression, and promoting invasion and metastasis of HCC. However, the function of ETV4 on angiogenesis in HCC remains unclear. In the current study, immunohistochemistry showed that knockdown of ETV4 reduced angiogenesis in HCC xenograft tumor tissues. In vitro, tube formation assay verified that ETV4 expression promoted angiogenesis through simulating the angiogenic environment in HCC cells. Transcriptome sequencing indicated that MMP14 was one of the differentially expressed genes enriched in angiogenesis process. Subsequently, it was confirmed that MMP14 was regulated by ETV4 at the transcription level in HCC cells, clinical tissue samples and online databases. Further, we demonstrated that MMP14 induced angiogenesis in ETV4-mediated HCC microenvironment. Collectively, this research further reveals the biological mechanism of ETV4 in promoting the migration and invasion of HCC, and provides novel mechanistic insights and strategic guidance for anti-angiogenic therapy in HCC.

Transcription factor ETV4 promotes the development of hepatocellular carcinoma by driving hepatic TNF-α signaling.

BACKGROUND: Hepatic inflammation is the major risk factor of hepatocellular carcinoma (HCC). However, the underlying mechanism by which hepatic inflammation progresses to HCC is poorly understood. This study was designed to investigate the role of ETS translocation variant 4 (ETV4) in linking hepatic inflammation to HCC. METHODS: Quantitative real-time PCR and immunoblotting were used to detect the expression of ETV4 in HCC tissues and cell lines. RNA sequencing and luciferase reporter assays were performed to identify the target genes of ETV4. Hepatocyte-specific ETV4-knockout (ETV4fl/fl, alb-cre ) and transgenic (ETV4Hep-TG ) mice and diethylnitrosamine-carbon tetrachloride (DEN-CCL4 ) treatment experiments were applied to investigate the function of ETV4 in vivo. The Cancer Genome Atlas (TCGA) database mining and pathological analysis were carried out to determine the correlation of ETV4 with tumor necrosis factor-alpha (TNF-α) and mitogen-activated protein kinase 11 (MAPK11). RESULTS: We revealed that ETV4 was highly expressed in HCC. High levels of ETV4 predicted a poor survival rate of HCC patients. Then we identified ETV4 as a transcription activator of TNF-α and MAPK11. ETV4 was positively correlated with TNF-α and MAPK11 in HCC patients. As expected, an increase in hepatic TNF-α secretion and macrophage accumulation were observed in the livers of ETV4Hep-TG mice. The protein levels of TNF-α, MAPK11, and CD68 were significantly higher in the livers of ETV4Hep-TG mice compared with wild type mice but lower in ETV4fl/fl, alb-cre mice compared with ETV4fl/fl mice as treated with DEN-CCL4 , indicating that ETV4 functioned as a driver of TNF-α/MAPK11 expression and macrophage accumulation during hepatic inflammation. Hepatocyte-specific knockout of ETV4 significantly prevented development of DEN-CCL4 -induced HCC, while transgenic expression of ETV4 promoted growth of HCC. CONCLUSIONS: ETV4 promoted hepatic inflammation and HCC by activating transcription of TNF-α and MAPK11. Both the ETV4/TNF-α and ETV4/MAPK11 axes represented two potential therapeutic targets for highly associated hepatic inflammation and HCC. ETV4+TNF-α were potential prognostic markers for HCC patients.

ETS transcription factor ELK3 in human cancers: An emerging therapeutic target.

Cancer is a genetic and complex disorder, resulting from several events associated with onset, development, and metastasis. Tumor suppressors and oncogenes are among the main regulators of tumor progression, contributing to various cancer-related behaviors like cell proliferation, invasion, migration, epithelial-mesenchymal transition (EMT), cell cycle, and apoptosis. Transcription factors (TFs) could act as tumor suppressors or oncogenes in cancer progression. E-twenty-six/E26 (ETS) family of TFs have a winged helix-turn-helix (HLH) motif, which interacted with specific DNA regions with high levels of purines and GGA core. ETS proteins act as transcriptional repressors or activators to modulate the expression of target genes. ETS transcription factor ELK3 (ELK3), as a type of ETS protein, was shown to enhance in various cancers, suggesting that it may have an oncogenic role. These studies indicated that ELK3 promoted invasion, migration, cell cycle, proliferation, and EMT, and suppressed cell apoptosis. In addition, these studies demonstrated that ELK3 could be a promising diagnostic and prognostic biomarker in human cancer. Moreover, accumulating data proved that ELK3 could be a novel chemoresistance mediator in human cancer. Here, we aimed to explore the overall change of ELK3 and its underlying molecular mechanism in human cancers. Moreover, we aimed to investigate the potential role of ELK3 as a prognostic and diagnostic biomarker as well as its capability as a chemoresistance mediator in cancer.

E74­like ETS transcription factor 5 facilitates cell proliferation through regulating the expression of adenomatous polyposis coli 2 in non­small cell lung cancer.

E74­like ETS transcription factor 5 (ELF5) is known to regulate the specification and differentiation of epithelial cells in the embryonic lung. However, the pathological function of ELF5 in lung cancer has yet to be fully elucidated. In the present study, the expression of ELF5 was found to be significantly higher in lung adenocarcinoma compared with that in corresponding adjacent normal tissues. Subsequently, cell and animal experiments were performed to investigate the role of ELF5 in lung adenocarcinoma cells. The results indicated that the overexpression of ELF5 increased the proliferation of lung adenocarcinoma cells, whereas, by contrast, a reduction in the expression of ELF5 led to a decrease in their proliferation. Mechanistically, the hypothesis is advanced that ELF5 can promote lung cancer cell proliferation through inhibiting adenomatous polyposis coli 2 and increasing the expression of cyclin D1, which is a critical downstream target of the Wnt pathway. Taken together, these findings support the notion that ELF5 exerts an essential role in the proliferation of lung adenocarcinoma cells and may be a therapeutic target for the treatment of lung adenocarcinoma.

The Elk-3 target Abhd10 ameliorates hepatotoxic injury and fibrosis in alcoholic liver disease.

Alcoholic liver disease (ALD) and other forms of chronic hepatotoxic injury can lead to transforming growth factor ß1 (TGFß1)-induced hepatic fibrosis and compromised liver function, underscoring the need to develop novel treatments for these conditions. Herein, our analyses of liver tissue samples from severe alcoholic hepatitis (SAH) patients and two murine models of ALD reveals that the ALD phenotype was associated with upregulation of the transcription factor ETS domain-containing protein (ELK-3) and ELK-3 signaling activity coupled with downregulation of α/ß hydrolase domain containing 10 (ABHD10) and upregulation of deactivating S-palmitoylation of the antioxidant protein Peroxiredoxin 5 (PRDX5). In vitro, we further demonstrate that ELK-3 can directly bind to the ABHD10 promoter to inhibit its transactivation. TGFß1 and epidermal growth factor (EGF) signaling induce ABHD10 downregulation and PRDX5 S-palmitoylation via ELK-3. This ELK-3-mediated ABHD10 downregulation drives oxidative stress and disrupts mature hepatocyte function via enhancing S-palmitoylation of PRDX5's Cys100 residue. In vivo, ectopic Abhd10 overexpression ameliorates liver damage in ALD model mice. Overall, these data suggest that the therapeutic targeting of the ABHD10-PRDX5 axis may represent a viable approach to treating ALD and other forms of hepatotoxicity.

Heat shock protein family A member 8 serving as a co-activator of transcriptional factor ETV4 up-regulates PHLDA2 to promote the growth of liver cancer.

Heat shock protein family A member 8 (HSPA8) participates in the folding or degradation of misfolded proteins under stress and plays critical roles in cancer. In this study, we investigated the function of HSPA8 in the development of liver cancer. By analyzing the TCGA transcriptome dataset, we found that HSPA8 was upregulated in 134 clinical liver cancer tissue samples, and positively correlated with poor prognosis. IHC staining showed the nuclear and cytoplasmic localization of HSPA8 in liver cancer cells. Knockdown of HSPA8 resulted in a decrease in the proliferation of HepG2 and Huh-7 cells. ChIP-seq and RNA-seq analysis revealed that HSPA8 bound to the promoter of pleckstrin homology-like domain family A member 2 (PHLDA2) and regulated its expression. The transcription factor ETV4 in HepG2 cells activated PHLDA2 transcription. HSPA8 and ETV4 could interact with each other in the cells and colocalize in the nucleus. From a functional perspective, we demonstrated that HSPA8 upregulated PHDLA2 through the coactivating transcription factor ETV4 to enhance the growth of liver cancer in vitro and in vivo. From a therapeutic perspective, we identified both HSPA8 and PHDLA2 as novel targets in the treatment of HCC. In conclusion, this study demonstrates that HSPA8 serves as a coactivator of ETV4 and upregulates PHLDA2, leading to the growth of HCC, and is a potential therapeutic target in HCC treatment.

ELF3 suppresses gallbladder cancer development through downregulation of the EREG/EGFR/mTOR complex 1 signalling pathway.

The prognosis of gallbladder cancer (GBC) remains poor, and a better understanding of GBC molecular mechanisms is important. Genome sequencing of human GBC has demonstrated that loss-of-function mutations of E74-like ETS transcription factor 3 (ELF3) are frequently observed, with ELF3 considered to be a tumour suppressor in GBC. To clarify the underlying molecular mechanisms by which ELF3 suppresses GBC development, we performed in vivo analysis using a combination of autochthonous and allograft mouse models. We first evaluated the clinical significance of ELF3 expression in human GBC tissues and found that low ELF3 expression was associated with advanced clinical stage and deep tumour invasion. For in vivo analysis, we generated Pdx1-Cre; KrasG12D ; Trp53R172H ; Elf3f/f (KPCE) mice and Pdx1-Cre; KrasG12D ; Trp53R172H ; Elf3wt/wt (KPC) mice as a control and analysed their gallbladders histologically. KPCE mice developed larger papillary lesions in the gallbladder than those developed by KPC mice. Organoids established from the gallbladders of KPCE and KPC mice were analysed in vitro. RNA sequencing showed upregulated expression of epiregulin (Ereg) in KPCE organoids, and western blotting revealed that EGFR/mechanical targets of rapamycin complex 1 (mTORC1) were upregulated in KPCE organoids. In addition, ChIP assays on Elf3-overexpressing KPCE organoids showed that ELF3 directly regulated Ereg. Ereg deletion in KPCE organoids (using CRISPR/Cas9) induced EGFR/mTORC1 downregulation, indicating that ELF3 controlled EGFR/mTORC1 activity through regulation of Ereg expression. We also generated allograft mouse models using KPCE and KPC organoids and found that KPCE organoid allograft tumours exhibited poorly differentiated structures with mTORC1 upregulation and mesenchymal phenotype, which were suppressed by Ereg deletion. Furthermore, EGFR/mTORC1 inhibition suppressed cell proliferation and epithelial-mesenchymal transition in KPCE organoids. Our results suggest that ELF3 suppresses GBC development via downregulation of EREG/EGFR/mTORC1 signalling. EGFR/mTORC1 inhibition is a potential therapeutic option for GBC with ELF3 mutation. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Down-regulated MiRNA 29-b as a diagnostic marker in colorectal cancer and its correlation with ETV4 and Cyclin D1 immunohistochemical expression.

BACKGROUND: Colorectal cancer (CRC) is the most common malignant tumor of the gastrointestinal tract with unfavorable prognosis. Therefore, novel biomarkers that may be used for new diagnostic strategies and drug-targeting therapy should be developed. OBJECTIVES: To investigate the expression of miR-29b in CRC and its association with ETV4 and cyclin D1 expression. Moreover, the current work aims to investigate the association between them and the clinicopathological features of CRC. METHODS: The expression of miR-29b and ETV4 (by qRT-PCR) and ETV4 and cyclin D1 (immunohistochemistry) was investigated in 65 cases of colon cancer and surrounding healthy tissues. RESULTS: MiR-29b down-regulated and ETV4 and Cyclin D1 up-regulated significantly in colon cancer tissues compared to normal nearby colonic tissues. In addition, significant associations between ETV4 and cyclin D1 expressions and progressive stage and lymph node (LN) metastasis (P< 0.001 for each) were found. Furthermore, there was a negative correlation between miR-29b gene expression and ETV4 gene expression (r=-0.298, P<0.016). CONCLUSION: Down-regulation of miR-29b and over-expression of ETV4 and cyclin D1 may be utilized as early diagnostic marker for development of colon cancer. ETV4 and cyclin D1 correlate with poor prognostic indicators and considered as a possible target for therapy in colon cancer.