Elevated expression levels of the protein kinase DYRK1B induce mesenchymal features in A549 lung cancer cells.

BACKGROUND: The protein kinase DYRK1B is a negative regulator of cell proliferation but has been found to be overexpressed in diverse human solid cancers. While DYRK1B is recognized to promote cell survival and adaption to stressful conditions, the consequences of elevated DYRK1B levels in cancer cells are largely uncharted. METHODS: To elucidate the role of DYRK1B in cancer cells, we established a A549 lung adenocarcinoma cell model featuring conditional overexpression of DYRK1B. This system was used to characterize the impact of heightened DYRK1B levels on gene expression and to monitor phenotypic and functional changes. RESULTS: A549 cells with induced overexpression of wild type DYRK1B acquired a mesenchymal cell morphology with diminished cell-cell contacts and a reorganization of the pericellular actin cytoskeleton into stress fibers. This transition was not observed in cells overexpressing a catalytically impaired DYRK1B variant. The phenotypic changes were associated with increased expression of the transcription factors SNAIL and SLUG, which are core regulators of epithelial mesenchymal transition (EMT). Further profiling of DYRK1B-overexpressing cells revealed transcriptional changes that are characteristic for the mesenchymal conversion of epithelial cells, including the upregulation of genes that are related to cancer cell invasion and metastasis. Functionally, DYRK1B overexpression enhanced the migratory capacity of A549 cells in a wound healing assay. CONCLUSIONS: The present data identify DYRK1B as a regulator of phenotypic plasticity in A549 cells. Increased expression of DYRK1B induces mesenchymal traits in A549 lung adenocarcinoma cells.

Chaperone-mediated autophagy modulates Snail protein stability: implications for breast cancer metastasis.

Breast cancer remains a significant health concern, with triple-negative breast cancer (TNBC) being an aggressive subtype with poor prognosis. Epithelial-mesenchymal transition (EMT) is important in early-stage tumor to invasive malignancy progression. Snail, a central EMT component, is tightly regulated and may be subjected to proteasomal degradation. We report a novel proteasomal independent pathway involving chaperone-mediated autophagy (CMA) in Snail degradation, mediated via its cytosolic interaction with HSC70 and lysosomal targeting, which prevented its accumulation in luminal-type breast cancer cells. Conversely, Snail predominantly localized to the nucleus, thus evading CMA-mediated degradation in TNBC cells. Starvation-induced CMA activation downregulated Snail in TNBC cells by promoting cytoplasmic translocation. Evasion of CMA-mediated Snail degradation induced EMT, and enhanced metastatic potential of luminal-type breast cancer cells. Our findings elucidate a previously unrecognized role of CMA in Snail regulation, highlight its significance in breast cancer, and provide a potential therapeutic target for clinical interventions.

Homeobox B9 promotes the invasion and metastasis of hepatocellular carcinoma cells via the EZH2-MIR203A-SNAI2 axis.

BACKGROUND: Research has elucidated that homeobox B9 (HOXB9), an important transcriptional activator, plays a pivotal role in promoting the invasion and metastasis of hepatocellular carcinoma (HCC) cells. However, the mechanism by which HOXB9 promotes the invasion and metastasis of HCC cells is incompletely understood and needs further exploration. METHODS: HOXB9 and snail family transcriptional repressor 2 (SNAI2) expression were analyzed using qRT-PCR and western blotting. The invasion and metastasis of hepatocellular carcinoma (HCC) cells were investigated using in vitro and in vivo assays. The H3K27me3 enrichment and HOXB9 interaction with microRNA 203a (MIR203A) or SNAI2 were detected using ChIP-qPCR. Transcriptional activities of SNAI2 and MIR203A promoter were detected using dual-luciferase reporter assays. Co-IP and GST pull-down assays were performed to confirm the binding between HOXB9 and EZH2. RESULTS: HOXB9 and SNAI2 were highly expressed in HCC tissues and their expression was positively intercorrelated and associated with poor prognosis in patients with HCC. In vitro and in vivo experiments confirmed that HOXB9 can upregulate the expression of SNAI2 to promote the invasion and metastasis of HCC cells. Furthermore, HOXB9 elevated SNAI2 expression by inhibiting MIR203A expression, a tumor suppressor gene, in HCC cells. Mechanistically, HOXB9 recruited enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) through interaction with its WD-binding domain, which increased EZH2-mediated histone H3 lysine 27 trimethylation (H3K27me3) at the MIR203A promoter region, in turn repressing the transcriptional activity and expression of MIR203A and consequently increasing the SNAI2 level in HCC cells. Finally, empirical evidence from in vitro and in vivo studies confirmed that mitigation of the HOXB9-mediated enhancement of epigenetic silencing of MIR203A inhibited SNAI2 expression, impeding the invasion and metastasis of HCC cells. CONCLUSIONS: Our study reveals a novel mechanism by which HOXB9 promotes the invasion and metastasis of HCC cells and expands the understanding of the function of HOXB9 in tumor progression and provides a novel therapeutic strategy for curtailing HCC invasion and metastasis.

Inhibition of intestinal inflammation and fibrosis by Scutellaria Baicalensis georgi and Boswellia serrata in human epithelial cells and fibroblasts.

OBJECTIVE AND RATIONALE: Inflammatory bowel disease, including Crohn's disease and ulcerative colitis, manifests with chronic intestinal inflammation and frequent sequential fibrosis. Current pharmacological therapies may show harmful side effects and are not useful for prevention or resolution of fibrosis. Thus, the use of alternative therapies is emerging as a novel useful approach. Previous results suggest that Scutellaria baicalensis Georgi (SBG) and Boswellia serrata (BS) display anti-inflammatory properties. The aim of this study was to investigate in intestinal epithelial cells and fibroblasts the anti-inflammatory and anti-fibrotic potential of SBG and BS, alone or in combination. METHODS: Human colorectal adenocarcinoma cells (HT29), human intestinal epithelial cells (HIEC6) and human colon fibroblasts (CCD-18Co) were used. Cells were pretreated with SBG and BS and then exposed to pro-inflammatory and pro-fibrotic cytokines. RESULTS: SBG and BS extracts significantly decreased pro-inflammatory cytokine expression and improved epithelial restitution in HT29 and HIEC6 cells. Besides, fibrotic marker expression, including SNAIL, ACTA2, ZNF281, was strongly reduced. Colon myofibroblasts treated with SBG and BS showed a significant decrease of fibrotic markers as well. CONCLUSIONS: SBG and BS extracts significantly reduce inflammation and impair fibrosis in intestinal epithelial cells and colon myofibroblasts. No cooperative effect is observed.

The Scribble-SGEF-Dlg1 complex regulates E-cadherin and ZO-1 stability, turnover and transcription in epithelial cells.

SGEF (also known as ARHGEF26), a RhoG specific GEF, can form a ternary complex with the Scribble polarity complex proteins Scribble and Dlg1, which regulates the formation and maintenance of adherens junctions and barrier function of epithelial cells. Notably, silencing SGEF results in a dramatic downregulation of both E-cadherin and ZO-1 (also known as TJP1) protein levels. However, the molecular mechanisms involved in the regulation of this pathway are not known. Here, we describe a novel signaling pathway governed by the Scribble-SGEF-Dlg1 complex. Our results show that the three members of the ternary complex are required to maintain the stability of the apical junctions, ZO-1 protein levels and tight junction (TJ) permeability. In contrast, only SGEF is necessary to regulate E-cadherin levels. The absence of SGEF destabilizes the E-cadherin-catenin complex at the membrane, triggering a positive feedback loop that exacerbates the phenotype through the repression of E-cadherin transcription in a process that involves the internalization of E-cadherin by endocytosis, ß-catenin signaling and the transcriptional repressor Slug (also known as SNAI2).

Cisplatin­resistant germ cell tumor models: An exploration of the epithelial­mesenchymal transition regulator SLUG.

Germ cell tumors (GCTs) constitute diverse neoplasms arising in the gonads or extragonadal locations. Testicular GCTs (TGCTs) are the predominant solid tumors in adolescents and young men. Despite cisplatin serving as the primary therapeutic intervention for TGCTs, 10­20% of patients with advanced disease demonstrate resistance to cisplatin­based chemotherapy, and epithelial­mesenchymal transition (EMT) is a potential contributor to this resistance. EMT is regulated by various factors, including the snail family transcriptional repressor 2 (SLUG) transcriptional factor, and, to the best of our knowledge, remains unexplored within TGCTs. Therefore, the present study investigated the EMT transcription factor SLUG in TGCTs. In silico analyses were performed to investigate the expression of EMT markers in TGCTs. In addition, a cisplatin­resistant model for TGCTs was developed using the NTERA­2 cell line, and a mouse model was also established. Subsequently, EMT was assessed both in vitro and in vivo within the cisplatin­resistant models using quantitative PCR and western blot analyses. The results of the in silico analysis showed that the different histologies exhibited distinct expression profiles for EMT markers. Seminomas exhibited a lower expression of EMT markers, whereas embryonal carcinomas and mixed GCT demonstrated high expression. Notably, patients with lower SLUG expression had longer median progression­free survival (46.4 months vs. 28.0 months, P=0.022). In the in vitro analysis, EMT­associated genes [fibronectin; vimentin (VIM); actin, α2, smooth muscle; collagen type I α1; transforming growth factor­ß1; and SLUG] were upregulated in the cisplatin­resistant NTERA­2 (NTERA­2R) cell line after 72 h of cisplatin treatment. Consistent with this finding, the NTERA­2R mouse model demonstrated a significant upregulation in the expression levels of VIM and SLUG. In conclusion, the present findings suggested that SLUG may serve a crucial role in connecting EMT with the development of cisplatin resistance, and targeting SLUG may be a putative therapeutic strategy to mitigate cisplatin resistance.

PIM1 kinase promotes EMT-associated osimertinib resistance via regulating GSK3ß signaling pathway in EGFR-mutant non-small cell lung cancer.

Acquired resistance is inevitable in the treatment of non-small cell lung cancer (NSCLC) with osimertinib, and one of the primary mechanisms responsible for this resistance is the epithelial-mesenchymal transition (EMT). We identify upregulation of the proviral integration site for Moloney murine leukemia virus 1 (PIM1) and functional inactivation of glycogen synthase kinase 3ß (GSK3ß) as drivers of EMT-associated osimertinib resistance. Upregulation of PIM1 promotes the growth, invasion, and resistance of osimertinib-resistant cells and is significantly correlated with EMT molecules expression. Functionally, PIM1 suppresses the ubiquitin-proteasome degradation of snail family transcriptional repressor 1 (SNAIL) and snail family transcriptional repressor 2 (SLUG) by deactivating GSK3ß through phosphorylation. The stability and accumulation of SNAIL and SLUG facilitate EMT and encourage osimertinib resistance. Furthermore, treatment with PIM1 inhibitors prevents EMT progression and re-sensitizes osimertinib-resistant NSCLC cells to osimertinib. PIM1/GSK3ß signaling is activated in clinical samples of osimertinib-resistant NSCLC, and dual epidermal growth factor receptor (EGFR)/PIM1 blockade synergistically reverse osimertinib-resistant NSCLC in vivo. These data identify PIM1 as a driver of EMT-associated osimertinib-resistant NSCLC cells and predict that PIM1 inhibitors and osimertinib combination therapy will provide clinical benefit in patients with EGFR-mutant NSCLC.

Knockdown of PRDX2 Inhibits the Proliferation, Growth, Migration, Invasion, and MMP9 Activity of Ewing's Sarcoma Cells Cultured In Vitro.

BACKGROUND: Ewing's sarcoma (ES) is the second most common malignant primary bone tumor in children and adolescents. Peroxiredoxin 2 (PRDX2) is an antioxidant enzyme. AIMS: Here, we investigated the role and mechanism of PRDX2 in the development of ES. METHODS AND RESULTS: PRDX2 expression was knocked down in A673 and RDES cells by specific siRNA interference (si-PRDX2). Knockdown of PRDX2 strongly inhibited the proliferation, growth, migration, invasion, and MMP9 activity and induces apoptosis of A673 and RDES cells. si-PRDX2 significantly inhibited the phosphorylation of Akt and the expression of cyclin D1. The transcription factor that might regulate PRDX2 transcription was predicted with the JASPAR and UCSC databases, and analyzed using dual-luciferase and Chromatin co-immunoprecipitation experiments. SNAI1 could activate the transcription of PRDX2 by binding to predicted promoter binding site. CONCLUSION: PRDX2 may be a potential therapeutic target for ES.

TGF-ß and RAS jointly unmask primed enhancers to drive metastasis.

Epithelial-to-mesenchymal transitions (EMTs) and extracellular matrix (ECM) remodeling are distinct yet important processes during carcinoma invasion and metastasis. Transforming growth factor ß (TGF-ß) and RAS, signaling through SMAD and RAS-responsive element-binding protein 1 (RREB1), jointly trigger expression of EMT and fibrogenic factors as two discrete arms of a common transcriptional response in carcinoma cells. Here, we demonstrate that both arms come together to form a program for lung adenocarcinoma metastasis and identify chromatin determinants tying the expression of the constituent genes to TGF-ß and RAS inputs. RREB1 localizes to H4K16acK20ac marks in histone H2A.Z-loaded nucleosomes at enhancers in the fibrogenic genes interleukin-11 (IL11), platelet-derived growth factor-B (PDGFB), and hyaluronan synthase 2 (HAS2), as well as the EMT transcription factor SNAI1, priming these enhancers for activation by a SMAD4-INO80 nucleosome remodeling complex in response to TGF-ß. These regulatory properties segregate the fibrogenic EMT program from RAS-independent TGF-ß gene responses and illuminate the operation and vulnerabilities of a bifunctional program that promotes metastatic outgrowth.

Matrix Metalloproteinase 11 Promotes Migration and Invasion of Colorectal Cancer by Elevating Slug Protein.

Purpose: Matrix metalloproteinase-11 (MMP11), which belongs to the stromelysin subgroup, has been reported to play a role in the progression of colorectal cancer (CRC). However, the significance of MMP11 in the tumor microenvironment, immune/stromal cells, and its mechanism in CRC remain unclear. Methods: The impact of MMP11 knockdown using specific short hairpin RNAs (shRNAs) on the metastasis and invasion of colorectal cancer RKO and SW480 cells was investigated using western blot, quantitative real-time polymerase chain reaction (qRT-PCR), transwell assays, and immunohistochemistry. Results: MMP11 mRNA expression was significantly higher in CRC cells than in normal cells, and its expression was stimulated in CCD-18Co fibroblasts. Additionally, MMP11 expression was found to be higher in individuals aged ≤ 65 years, the T4/T3 group, and Stage III/IV patients. Overall survival (OS) and disease-free survival rates were significantly different between the high and low MMP11 groups. Furthermore, the receiver operating characteristic (ROC) curves for MMP11 at 1-, 3-, and 5-years were 0.450, 0.552, and 0.560, respectively. Moreover, MMP11 promoted the migration and invasion of CRC cells by elevating the expression of Slug protein. Most importantly, MMP11 was positively associated with M0-macrophages and negatively associated with M1-macrophages, NK cells activated, NK cells resting, T cells CD4 memory activated, and T cells follicular helper, indicating the remarkable interactions of MMP11 with tumor immunology. Conclusions: MMP11 plays an important role in colorectal cancer development, and its mechanism in CRC needs to be further explored in the future.

SNAI1: a key modulator of survival in lung squamous cell carcinoma and its association with metastasis.

BACKGROUND: Snail family zinc finger 1 (SNAI1) has been implicated in cancer progression and prognosis across various malignancies. This study aims to elucidate the prognostic significance of SNAI1 expression in Lung Squamous Cell Carcinoma (LUSC) using data from The Cancer Genome Atlas (TCGA) database. METHODS: SNAI1 expression levels in LUSC patients were stratified using X-tile software to establish optimal cut-off values. Kaplan-Meier survival analysis was performed to assess the impact of SNAI1 expression on overall survival (OS). Univariate and multivariate Cox regression analyses were conducted to evaluate the prognostic value of SNAI1, considering clinical parameters such as age, clinical stage, and TNM classification. Additionally, we explored the interaction between SNAI1 expression and metastatic status, and performed Gene Set Enrichment Analysis (GSEA) to investigate associated cellular pathways. Correlations between SNAI1 and immune checkpoint molecules were also examined. RESULTS: Kaplan-Meier analysis revealed significant differences in OS among high, medium, and low SNAI1 expression groups (p < 0.001), with median survival times of 1.6, 3.0, and 5.8 years, respectively. Dichotomizing patients into high and low SNAI1 expression groups confirmed that high SNAI1 expression was associated with significantly poorer OS (p < 0.001). SNAI1 remained an independent prognostic factor in multivariate analysis. High SNAI1 expression correlated with poorer survival outcomes regardless of metastatic status, and the combination of high SNAI1 expression and metastasis resulted in the poorest survival. GSEA identified significant associations between SNAI1 and inflammatory, immune response pathways. Positive correlations were observed between SNAI1 and key immune checkpoint molecules, suggesting an interplay with immune checkpoint mechanisms. CONCLUSIONS: High SNAI1 expression is a robust prognostic indicator of poor survival in LUSC, independent of other clinical factors. Its association with immune checkpoint molecules highlights its potential as a therapeutic target. These findings underscore the prognostic and therapeutic relevance of SNAI1 in LUSC and possibly other cancers. Further research is warranted to explore targeted therapies against SNAI1.

A SRC-slug-TGFß2 signaling axis drives poor outcomes in triple-negative breast cancers.

BACKGROUND: Treatment options for the Triple-Negative Breast Cancer (TNBC) subtype remain limited and the outcome for patients with advanced TNBC is very poor. The standard of care is chemotherapy, but approximately 50% of tumors develop resistance. METHODS: We performed gene expression profiling of 58 TNBC tumor samples by microarray, comparing chemosensitive with chemoresistant tumors, which revealed that one of the top upregulated genes was TGFß2. A connectivity mapping bioinformatics analysis predicted that the SRC inhibitor Dasatinib was a potential pharmacological inhibitor of chemoresistant TNBCs. Claudin-low TNBC cell lines were selected to represent poor-outcome, chemoresistant TNBC, for in vitro experiments and in vivo models. RESULTS: In vitro, we identified a signaling axis linking SRC, AKT and ERK2, which in turn upregulated the stability of the transcription factors, Slug and Snail. Slug was shown to repress TGFß2-antisense 1 to promote TGFß2 signaling, upregulating cell survival via apoptosis and DNA-damage responses. Additionally, an orthotopic allograft in vivo model demonstrated that the SRC inhibitor Dasatinib reduced tumor growth as a single agent, and enhanced responses to the TNBC mainstay drug, Epirubicin. CONCLUSION: Targeting the SRC-Slug-TGFß2 axis may therefore lead to better treatment options and improve patient outcomes in this highly aggressive subpopulation of TNBCs.

In our study, we focused on a particular subtype of aggressive breast cancer called Triple-Negative Breast Cancer (TNBC). We investigated a complex series of events that contribute to poor outcomes in this disease and uncovered a crucial signaling cascade driving tumor growth and progression.At the core of this signaling cascade are three key proteins: SRC, AKT, and ERK2. Together, they form a pathway that activates a transcription factor called Slug. Transcription factors act like molecular switches, controlling the expression of genes. Once Slug is activated, it strongly suppresses genes that would normally restrict cell growth and cell spread.One of the genes downregulated by Slug is TGFB2-AS1. This product of the TGFB2-AS1 gene normally controls levels of its target protein called TGF-beta2 (TGFB2), a protein which has roles in cell growth, cell migration and differentiation. Slug downregulation of TGFB2-AS1 results in higher TGFB2 levels, and this in turn contributes to the uncontrolled growth and spread of cancer cells. TGFB2, and other proteins in this pathway (SRC, AKT, ERK2, and a Slug interactor called LSD1) all maintain the stability of Slug, meaning that Slug levels remain high and drive the aggressive features of this subtype of breast cancer.Overall, our research sheds light on the intricate molecular mechanisms driving aggressive TNBC. It also identifies potential targets for future therapies, aimed at disrupting this harmful signaling pathway and potentially improving patient outcomes for this disease.

Snail Expression as a Prognostic Factor in Colorectal Adenocarcinoma.

OBJECTIVE: The aim of this study was to analyze the expression of Snail in the colorectal adenocarcinoma. METHODS: This study used a cross-sectional design. Seventy four paraffin embedded block of Colorectal Adenocarcinoma were assessed using Snail rabbit polyclonal antibody and their expression were performed using Olympus CX-43 light microscope. The relationship between Snail expression with histopathological grading, tumor budding grading, lymphovascular invasion and metastases of colorectal adenocarcinoma ability were statistically analyzed by Mann Whitney tests and presented in tables using SPSS 27. RESULT: From 74 samples examined, in samples with low grade tumor budding (n=11), there were 9 samples (81.8%) with weak expression, while those with strong expression were 2 samples (18.2%). In samples with intermediate grade tumor budding (n=28), there were 17 samples (60.7%) with weak expression, while those with strong expression were 11 samples (39.3%). In samples with high grade tumor budding (n=35), there were 13 samples (37.1%) with weak expression, while those with strong expression were 22 samples (62.9%). In samples with lymphovascular invasion (n=14), there were 10 samples (71.4%) with strong expression, while those with weak expression were 4 samples (28.6%). In samples with metastases (n=23), there were 16 samples (69.6%) with strong expression, while those with weak expression were 7 samples (30.4%). There was a significant relationship between the expression of Snail with tumor budding grade (p=0.003), lymphovascular invasion and metastases (p=<0.001), but there was no significant relationship with histopathological grade (p=0.942). CONCLUSION: The Snail expression can be used as a prognostic factor in colorectal adenocarcinoma.

Expression of LOXL3, NES, and SNAI1 in Melanoma Genesis and Progression.

Melanoma is the most severe type of skin cancer and among the most malignant neoplasms in humans. With the growing incidence of melanoma, increased numbers of therapeutic options, and the potential to target specific proteins, understanding the basic mechanisms underlying the disease's progression and resistance to treatment has never been more important. LOXL3, SNAI1, and NES are key factors in melanoma genesis, regulating tumor growth, metastasis, and cellular differentiation. In our study, we explored the potential role of LOXL3, SNAI1, and NES in melanoma progression and metastasis among patients with dysplastic nevi, melanoma in situ, and BRAF+ and BRAF- metastatic melanoma, using immunofluorescence and qPCR analysis. Our results reveal a significant increase in LOXL3 expression and the highest NES expression in BRAF+ melanoma compared to BRAF-, dysplastic nevi, and melanoma in situ. As for SNAI1, the highest expression was observed in the metastatic melanoma group, without significant differences among groups. We found co-expression of LOXL3 and SNAI1 in the perinuclear area of all investigated subgroups and NES and SNAI1 co-expression in melanoma cells. These findings suggest a codependence or collaboration between these markers in melanoma EMT, suggesting new potential therapeutic interventions to block the EMT cascade that could significantly affect survival in many melanoma patients.

The epigenetic-modified downregulation of LOXL1 protein mediates EMT in bladder epithelial cells exposed to benzo[a]pyrene and its metabolite BPDE.

Benzo[a]pyrene (B[a]P) is a well-known polycyclic aromatic hydrocarbon (PAH) pollutant with high carcinogenicity, widespread environmental presence, and significant threat to public health. Epidemiological studies have linked exposure to B[a]P and its metabolite 7,8-dihydroxy-9,10-epoxybenzo[a]pyrene (BPDE) to the development and progression of various cancers, including bladder cancer. However, its underlying mechanism remains unclear. Our study revealed that B[a]P and BPDE induced epithelial-mesenchymal transition (EMT), a critical early event in cell malignant transformation, involving a decrease in E-Cadherin and upregulation of N-Cadherin protein levels, leading to increased cell motility and migration in bladder epithelial cells. Further studies have indicated that LOXL1 DNA undergoes methylation and modification influenced by methyltransferase 3a (DNMT3a) and DNMT3b, resulting in decreased LOXL1 protein levels. The decreased LOXL1 promotes the zinc finger transcription factor SLUG, which then inhibits E-Cadherin protein levels and initiates the EMT process. Moreover, DNMT3a/3b expression appears to be influenced by intracellular oxidative stress levels. These findings suggest that exposure to B[a]P/BPDE promotes the EMT process through the pivotal factor LOXL1, thereby contributing to bladder carcinogenesis. Our study provides a theoretical basis for considering LOXL1 as a potential biomarker for early diagnosis and a novel target for the precise diagnosis and treatment of bladder cancer.

Docetaxel-Induced Cell Death Is Regulated by a Fatty Acid-Binding Protein 12-Slug-Survivin Pathway in Prostate Cancer Cells.

Chemotherapy is an important treatment option for advanced prostate cancer, especially for metastatic prostate cancer (PCa). Resistance to first-line chemotherapeutic drugs such as docetaxel often accompanies prostate cancer progression. Attempts to overcome resistance to docetaxel by combining docetaxel with other biological agents have been mostly unsuccessful. A better understanding of the mechanisms underlying docetaxel resistance may provide new avenues for the treatment of advanced PCa. We have previously found that the fatty acid-binding protein 12 (FABP12)-PPARγ pathway modulates lipid-related bioenergetics and PCa metastatic transformation through induction of Slug, a master driver of epithelial-to-mesenchymal transition (EMT). Here, we report that the FABP12-Slug axis also underlies chemoresistance in PCa cells. Cell sensitivity to docetaxel is markedly suppressed in FABP12-expressing cells, along with induction of Survivin, a typical apoptosis inhibitor, and inhibition of cleaved PARP, a hallmark of programmed cell death. Importantly, Slug depletion down-regulates Survivin and restores cell sensitivity to docetaxel in FABP12-expressing cells. Finally, we also show that high levels of Survivin are associated with poor prognosis in PCa patients, with FABP12 status determining its prognostic significance. Our research identifies a FABP12-Slug-Survivin pathway driving docetaxel resistance in PCa cells, suggesting that targeting FABP12 may be a precision approach to improve chemodrug efficacy and curb metastatic progression in PCa.

Hippo pathway effectors YAP, TAZ and TEAD are associated with EMT master regulators ZEB, Snail and with aggressive phenotype in phyllodes breast tumors.

BACKGROUND: Phyllodes tumors (PTs) of the breast are uncommon fibroepithelial neoplasms that tend to recur locally and may have metastatic potential. Their pathogenesis is poorly understood. Hippo signaling pathway plays an essential role in organ size control, tumor suppression, tissue regeneration and stem cell self-renewal. Hippo signaling dysfunction has been implicated in cancer. Recent evidence suggests that there is cross-talk between the Hippo signaling key proteins YAP/TAZ and the epithelial-mesenchymal transition (EMT) master regulators Snail and ZEB. In this study we aimed to investigate the expression of Hippo signaling pathway components and EMT regulators in PTs, in relation to tumor grade. METHODS: Expression of Hippo signaling effector proteins YAP, TAZ and their DNA binding partner TEAD was evaluated by immunohistochemistry in paraffin-embedded tissue specimens from 86 human phyllodes breast tumors (45 benign, 21 borderline, 20 malignant), in comparison with tumor grade and with the expression of EMT-related transcription factors ZEB and Snail. RESULTS: Nuclear immunopositivity for YAP, TAZ and TEAD was detected in both stromal and epithelial cells in PTs and was significantly higher in high grade tumors. Interestingly, there was a significant correlation between the expression of YAP, TAZ, TEAD and the expression of ZEB and SNAIL. CONCLUSIONS: Our results originally implicate Hippo signaling pathway in PTs pathogenesis and suggest that an interaction between Hippo signaling key components and EMT regulators may promote the malignant features of PTs.

Dysregulated lncSNHG12 suppresses the invasion and migration of trophoblasts by regulating Dio2/Snail axis to involve in recurrent spontaneous abortion.

Recurrent spontaneous abortion (RSA) is a complex pathological process involving diverse factors, in which the dysregulated functions of trophoblasts cannot be ignored. Long noncoding RNA (lncRNA) has been reported to play a significant role in regulating the functions of trophoblasts in RSA. However, the impact and potential mechanism of lncRNA small nucleolar RNA host gene 12 (lncSNHG12) remain unclear. The role of lncSNHG12 in RSA was investigated through in vivo experiments and clinical samples. Co-IP and RNA pull down were conducted to explore the molecular mechanisms in trophoblasts. Our results showed that lncSNHG12 promoted the migration and invasion of trophoblasts by interacting with Iodothyronine deiodinase 2 (Dio2), which regulating the EMT process of trophoblasts by interacting with Snail. Moreover, in vivo experiments confirmed that lncSNHG12 could improve the fetal absorption rate of the abortion mice. The clinical samples revealed that lncSNHG12, Dio2 and Snail were down-regulated in the villous tissues of RSA patients, and positive correlations were confirmed between lncSNHG12 and Dio2, as well as Dio2 and Snail. In summary, the lncSNHG12/Dio2/Snail axis might be involved in the development of RSA by regulating the invasion and migration of trophoblasts. Abbreviations: RSA, recurrent spontaneous abortion; EVTs, extravillous trophoblasts; EMT, epithelial-to-mesenchymal transition; lncRNA, long non-coding RNA; Dio2, iodothyronine deiodinase 2; SNHGs, small nuclear RNA host genes; snoRNAs, small nuclear cell RNAs; LPS, lipopolysaccharide; De, derived decidua; Jz, junctional zone; Lz, labyrinth zones; RIP, RNA Binding Protein Immunoprecipitation; Co-IP, Co-Immunoprecipitation; RPISeq, RNA-Protein Interaction Prediction.

ACTN4 is associated with the malignant potential of thymic epithelial tumors through the ß-catenin/Slug pathway.

Thymic epithelial tumors (TETs) are rare tumors arising from the mediastinum. Among TETs, thymoma type B2, B3 and thymic carcinoma are highly malignant and often present invasion and dissemination. However, the biological characteristics of TETs have not been thoroughly studied, and their mechanisms of invasion and dissemination are largely unknown. α-Actinin 4 (ACTN4) is a member of actin-binding proteins and reportedly plays important roles in the progression of several cancers. In this study, we investigated the relationship between ACTN4 and characteristics of the malignant potential of TETs, such as invasion and dissemination. In vitro experiments using Ty-82 thymic carcinoma cells revealed that overexpression of ACTN4 enhanced the proliferative and invasive ability of Ty-82 cells; conversely, knockdown of ACTN4 attenuated the proliferative and invasive potential of Ty-82 cells. In western blotting (WB) experiments, ACTN4 induced the phosphorylation of extracellular signal-regulated kinase and glycogen synthase kinase 3ß to regulate the ß-catenin/Slug pathway. Furthermore, WB analysis of cancer tissue-origin spheroids from patients with TETs showed results similar to those for Ty-82 cells. In vivo experiments showed that the knockdown of ACTN4 significantly suppressed the dissemination of Ty-82 cells. A WB and immunohistochemistry staining comparison of primary and disseminated lesions of TETs using surgical specimens showed upregulated expression of ACTN4, ß-catenin, and Slug proteins in disseminated lesions. In summary, our study suggests ACTN4 is associated with malignant potential characteristics such as invasion and dissemination in TETs via the ß-catenin/Slug pathway.

Titanium nanoparticles released from orthopedic implants induce muscle fibrosis via activation of SNAI2.

Titanium alloys represent the prevailing material employed in orthopedic implants, which are present in millions of patients worldwide. The prolonged presence of these implants in the human body has raised concerns about possible health effects. This study presents a comprehensive analysis of titanium implants and surrounding tissue samples obtained from patients who underwent revision surgery for therapeutic reasons. The surface of the implants exhibited nano-scale corrosion defects, and nanoparticles were deposited in adjacent samples. In addition, muscle in close proximity to the implant showed clear evidence of fibrotic proliferation, with titanium content in the muscle tissue increasing the closer it was to the implant. Transcriptomics analysis revealed SNAI2 upregulation and activation of PI3K/AKT signaling. In vivo rodent and zebrafish models validated that titanium implant or nanoparticles exposure provoked collagen deposition and disorganized muscle structure. Snai2 knockdown significantly reduced implant-associated fibrosis in both rodent and zebrafish models. Cellular experiments demonstrated that titanium dioxide nanoparticles (TiO2 NPs) induced fibrotic gene expression at sub-cytotoxic doses, whereas Snai2 knockdown significantly reduced TiO2 NPs-induced fibrotic gene expression. The in vivo and in vitro experiments collectively demonstrated that Snai2 plays a pivotal role in mediating titanium-induced fibrosis. Overall, these findings indicate a significant release of titanium nanoparticles from the implants into the surrounding tissues, resulting in muscular fibrosis, partially through Snai2-dependent signaling.