Levels Of Snail Research Articles

Oroxylin A suppressed colorectal cancer metastasis by inhibiting the activation of the TGF-β/SMAD signal pathway

Metastatic colorectal cancer continues to have a high fatality rate, with approximately only 14% of patients surviving more than 5 years. To improve the survival rate of these patients, the development of new therapeutic drugs is a priority. In this study, we investigated the effects of Oroxylin A on the metastasis of human colorectal cancer cells and its potential molecular mechanism. This study utilised CCK8 assay, transwell assay, flow cytometry, western blot analysis, molecular docking, HE staining, immunofluorescence staining, and xenograft models. The proliferation, migration, and invasion of colon cancer cells were effectively suppressed by Oroxylin A in a dose-dependent manner. Oroxylin A has the potential to inhibit the process of epithelial‒mesenchymal transition (EMT) by upregulating the expression of E-cadherin, a marker associated with epithelial cells, while downregulating the levels of N-cadherin, Snail, vimentin, and slug, which are markers associated with mesenchymal cells. In addition, 200 mg/kg of Oroxylin A inhibited the growth of colorectal tumours. Molecular docking technology revealed that Oroxylin A can bind to TGFβ and inhibit the activation of the TGFβ-smad signalling pathway. The overexpression of TGFβ weakened the inhibitory effect of Oroxylin A on the proliferation, migration, and invasion of human colorectal cancer cells, as well as the promoting effect on apoptosis. Oroxylin A inhibited the activation of the TGF-smad signalling pathway and the EMT process, thereby suppressing the migration and invasion of human colorectal cancer cells.

Activation of the Snail transcription factor induces Mdm2 gene expression

Epithelial-like tumor cells can become metastatic by undergoing molecular and phenotypic reprogramming in a process referred to as epithelial-to-mesenchymal transition (EMT). In response to EMT genes that promote migration and condition the tumor microenvironment to permit intravasation into the bloodstream, dissemination, and extravasation into new organs are induced. While the mutant p53 has been implicated in extravasation, one negative regulator of p53, the oncogene Mdm2, is required in the early stages of metastasis and the driver of EMT. This activity is independent of Mdm2’s role in the p53-Mdm2 autoregulatory feedback loop. Herein, we examine the EMT transcription factor Snail as a downstream effector of kinase signaling pathways. We show that the activation of upstream receptors and KRas signaling increase Snail levels. Snail binds to Ebox DNA motifs, and Mdm2 has two Ebox DNA binding domains in the second promoter. Snail binds to the second Ebox and induces Mdm2 gene expression. Knockdown of endogenous Snail by shRNA shows a decrease in Mdm2 and is associated with reduced migration. The reintroduction of Mdm2 in shSnail cells restores cellular migration. These data integrate upstream pathways that induce Snail-Mdm2 to promote the metastasis of tumor cells.

Interleukin-9 promotes EMT-mediated PM2.5-induced pulmonary fibrosis by activating the STAT3 pathway.

This study investigated the impact of PM2.5 on promoting EMT in PM2.5-induced pulmonary fibrosis (PF) development and explored molecular mechanisms of the IL-9/STAT3/Snail/TWIST1 signaling pathway in PF owing to PM2.5. Four groups of male SD rats were formed: control (0mg/kg.bw), low (1mg/kg.bw), medium (5mg/kg.bw), and high-dose (25mg/kg.bw) PM2.5 groups. Experimental rats were subjected to PM2.5 exposure via intratracheal instillation, given once weekly for 16weeks. 24 h after the final exposure, blood, BALF, and lung tissues were collected. Pulmonary epithelial cells underwent cultivation and exposure to varying PM2.5 concentrations with/without inhibitors for 24h, after which total protein was extracted for relevant protein assays. The findings demonstrated that PM2.5 damaged lung tissue to different degrees and led to PF in rats. Rats subjected to PM2.5 exposure exhibited elevated concentrations of IL-9 protein in both serum and BALF, and elevated levels of IL-9 and its receptor, IL-9R, in lung tissues, compared to control counterparts. Furthermore, PM2.5-exposed groups demonstrated significantly augmented protein levels of p-STAT3, Snail, TWIST1, Vimentin, COL-I, and α-SMA, while displaying notably diminished levels of E-Cadherin compared to control group. The same findings were observed in PM2.5-treated cells. In BEAS-2B cells co-treated with Stattic (STAT3 inhibitor) and PM2.5, the opposite results occurred. Similar results were obtained for cells co-treated with IL-9-neutralizing antibody and PM2.5. Our findings suggest PM2.5 mediates PF development by promoting IL-9 expression, leading to STAT3 phosphorylation and upregulation of Snail and TWIST1 expression, triggering EMT occurrence and progression in lung epithelial cells.

BUB1 induces AKT/mTOR pathway activity to promote EMT induction in human small cell lung cancer

Small cell lung cancer (SCLC) is a very aggressive tumor. Abnormal expression of BUB1 has been reported in several cancer types, wherein it plays a range of functional roles. This work aimed to elucidate the functional significance and molecular impacts of BUB1 in SCLC. It was found that SCLC cell lines exhibited significant BUB1 upregulation relative to control bronchial cells using data from the Gene Expression Omnibus (GEO) database and verified by immunohistochemical staining. BUB1 was also found to promote the proliferative, migratory, invasive activity of SCLC cells, as shown by CCK-8, 3D migration wound-healing, and Transwell assays, as well as flow cytometry. Additionally, it was found that BUB1 silencing enhanced E-cadherin expression while suppressing N-cadherin, Vimentin, ZEB-1, and Snail levels, as shown by Western immunoblotting. The loss of BUB1 also reduced p-AKT and p-mTOR levels without altering total AKT or mTOR protein levels. In conclusion, BUB1 functions as an oncogenic promoter in SCLC, potentially regulating the epithelial-mesenchymal transition by activation of AKT/mTOR signaling.

Indoleamine 2,3-Dioxygenase Inhibitor Suppresses Colon Cancer Cell Migration, Invasion, and Epithelial-Mesenchymal Transition.

Indoleamine 2,3-dioxygenase 1 (IDO1) is a key enzyme in tryptophan metabolism and plays an important role in immunosuppression. The effects of IDO1 on tumor invasion and metastasis have been studied in several types of malignancies. However, the role of IDO1 in these steps in colorectal cancer (CRC) has not been elucidated. Therefore, we aimed to investigate the effects of IDO1 on invasion, migration, and epithelial-mesenchymal transition (EMT) in CRC cells. All experiments were performed using the DLD-1 colon cancer cell line that expresses IDO1. We conducted a scratch wound healing assay and Boyden chamber assay to investigate the impact of IDO1 on DLD-1 cell migration and invasion, respectively, in the presence and absence of the IDO1 inhibitor L-1-methyl-tryptophan (L-1-MT). Additionally, western blotting was performed to analyze alterations in the expression of EMT-related markers caused by L-1-MT. High expression of IDO1 was confirmed in the cytoplasm of DLD-1 by immunofluorescence staining. In the scratch wound healing assay, the invasion ability of DLD-1 cells decreased to 62% after treatment with L-1-MT at 1,000 μM for 24 h. In the Boyden chamber assay, the migration of DLD-1 cells was suppressed by 85% after treatment with L-1-MT at 2,500 μM for 24 h. L-1-MT treatment increased the expression level of E-cadherin and decreased the expression levels of vimentin, Snail, and Slug. IDO1 inhibition reduced the invasion and migration ability of IDO1-expressing DLD-1 colon cancer cells, which was accompanied by altered expression of EMT-related proteins. IDO1 could be a potential target for the treatment of advanced CRC.

Polygonatum sibiricum component liquiritigenin restrains breast cancer cell invasion and migration by inhibiting HSP90 and chaperone-mediated autophagy.

Breast cancer (BC) is most commonly diagnosed worldwide. Liquiritigenin is a flavonoid found in various species of the Glycyrrhiza genus, showing anti-tumor activity. This article was to explore the influences of liquiritigenin on the biological behaviors of BC cells and its underlying mechanism. BC cells were treated with liquiritigenin alone or transfected with oe-HSP90 before liquiritigenin treatment. RT-qPCR and Western blotting were employed to examine the levels of HSP90, Snail, E-cadherin, HSC70, and LAMP-2A. Cell viability, proliferation, migration, and invasion were evaluated by performing MTT, colony formation, scratch, and Transwell assays, respectively. Liquiritigenin treatment reduced HSP90 and Snail levels and enhanced E-cadherin expression as well as inhibiting the proliferation, migration, and invasion of BC cells. Moreover, liquiritigenin treatment decreased the expression of HSC70 and LAMP-2A, proteins related to chaperone-mediated autophagy (CMA). HSP90 overexpression promoted the CMA, invasion, and migration of BC cells under liquiritigenin treatment. Liquiritigenin inhibits HSP90-mediated CMA, thereby suppressing BC cell growth.

Silencing LINC00663 inhibits inflammation and angiogenesis through downregulation of NR2F1 via EBF1 in bladder cancer

ABSTRACT This study is to elucidate the effect of the LINC00663/EBF1/NR2F1 axis on inflammation and angiogenesis in bladder cancer (BC) and related molecular mechanisms. After transfection, functional experiments were conducted to test cell proliferation and invasion, tube formation ability, and content of inflammatory factors, Snail, E-cadherin, and VEGFA. Meanwhile, the relationships among LINC00663, EBF1, and NR2F1 were predicted and verified. In addition, xenograft experiments in nude mice were performed to observe the oncogenicity of 5637 BC cells in vivo. In BC tissues and cells, LINC00663 and NR2F1 were upregulated. Silencing NR2F1 or LINC00663 repressed cell proliferation and invasion, weakened vascular mimicry in vitro, decreased inflammatory factor, Snail, and VEGFA levels, and increased expression of E-cadherin. LINC00663 positively regulated NR2F1 expression through EBF1. Additionally, in vivo experiments showed that NR2F1 upregulation reversed the suppression effects of LINC00663 silencing on tumour growth, inflammation, and angiogenesis. Silencing LINC00663 decreased NR2F1 expression by mediating EBF1, thereby inhibiting BC inflammation and angiogenesis.

Bioaccumulation of trace metals in edible terrestrial snails, Theba pisana and Otala spp., in a dumpsite area in Morocco and assessment of human health risks for consumers.

This study assessed the bioaccumulation patterns of five trace metals (Cd, Cr, Co, Cu, and Zn) in two edible snail species, Theba pisana and Otala spp., collected from a dumpsite in Safi City, Morocco. The results indicated that bioaccumulation might be species-specific, as metal concentration profiles varied between the two snail species. Additionally, higher metal levels in the dumpsite snails confirmed their potential as bioindicators of trace metal pollution in terrestrial environments. However, the distribution of trace elements within the edible parts of the snails showed marked unevenness, with the viscera accumulating more metals than the foot. The study also evaluated the potential human health risks associated with consuming these snails. Trace metal levels in the edible parts exceeded most international safety thresholds. The estimated daily intakes (EDIs) of trace metals through snail consumption were below the provisional tolerable daily intakes (PTDIs) for both children and adults, suggesting that daily consumption is generally safe. Nonetheless, the hazard index (HI) indicated that children might face health risks from long-term consumption of contaminated snails (HI > 1), while adults are less likely to experience such complications (HI < 1). The total target carcinogenic risk (TTCR) was below 1E-04 for both children and adults, indicating negligible to acceptable carcinogenic risks for all consumer groups.

MiR-1202 regulates BPH-1 cell proliferation, apoptosis, and epithelial-to-mesenchymal transition through targeting HMGCL.

Benign prostatic hyperplasia (BPH) is the expansion of the prostate gland that results in urinary symptoms. Both the epithelial-to-mesenchymal transition (EMT) and the Wnt signaling pathway are associated with BPH pathology. In this study, we find that miR-1202 is increased in BPH samples. Overexpression of miR-1202 in TGF-β-treated BPH-1 cells enhances cell survival and DNA synthesis and inhibits cell apoptosis, whereas miR-1202 inhibition partially abolishes the effects of TGF-β on BPH-1 cells. miR-1202 overexpression reduces E-cadherin level but elevates vimentin, N-cadherin, and snail levels, whereas miR-1202 inhibition partially attenuates the effects of TGF-β on EMT markers. Regarding the Wnt/β-catenin pathway, miR-1202 overexpression significantly enhances, whereas miR-1202 inhibition partially decreases, the promotive effects of TGF-β on Wnt1, c-Myc, and cyclin D1 proteins. 3-Hydroxy-3-methylglutaryl-CoA lyase (HMGCL) is a direct downstream target of miR-1202, and miR-1202 inhibits HMGCL expression through binding to its 3'UTR. Overexpression of HMGCL significantly reduces the effect of miR-1202 overexpression on the phenotypes of BPH-1 cells by inhibiting cell survival and promoting apoptosis. Similarly, HMGCL overexpression has the opposite effects on EMT markers and the Wnt/β-catenin signaling, and markedly alleviates the effects of miR-1202 overexpression. Finally, in the BPH rat model, Ki67 and vimentin levels are elevated, but E-cadherin and HMGCL levels are reduced. In conclusion, miR-1202 is upregulated in benign prostatic hyperplasia; miR-1202 enhances epithelial cell proliferation, suppresses cell apoptosis, and promotes EMT by targeting HMGCL. The Wnt/β-catenin pathway may participate in the miR-1202/HMGCL axis-mediated regulation of BPH-1 cell phenotypes.

Isogarcinol inhibits nasopharyngeal carcinoma growth through mitochondria-mediated autophagic cell death

Background and aimsIsogarcinol, a natural compound extracted from the fruits of Garcinia oblongifolia, has potential chemopreventive activity. This study aimed to elucidate the anti-tumor effects and mechanism of action of isogarcinol on nasopharyngeal carcinoma (NPC). MethodsIsogarcinol was isolated from Garcinia oblongifolia by using chromatographic separation. The anti-tumor effects of isogarcinol in NPC cells were tested by MTT assay, flow cytometry, wound healing assay, western blotting, transwell assay, colony formation assay, immunofluorescence, and transmission electron microscopy (TEM). The anti-tumor efficacy in vivo was evaluated in NPC cells xenograft models. ResultsFunctional studies revealed that isogarcinol inhibited the proliferation, colony formation, migration and invasion abilities of NPC cells in vitro. Isogarcinol caused mitochondrial damage to overproduce reactive oxygen species through reducing the mitochondrial membrane potential and ΔΨm. Isogarcinol also substantially inhibited NPC cells growth in a xenograft tumor model without any obvious toxicity when compared with paclitaxel (PTX). Mechanistic studies have illustrated that isogarcinol increased the Bax/Bcl-2 ratio, cleaved caspase-3, and cytoplasmic cytochrome C levels to induce mitochondrial apoptosis. The ROS overproduction by isogarcinol could suppress EMT pathway via decreasing the levels of p-Akt and Snail. Furthermore, isogarcinol promoted the conversion of LC3-Ⅰ to LC3-Ⅱ, but increased p62 level to block autophagic flux, resulting in the accumulation of damaged mitochondria to promote autophagic cell death in NPC cells. ConclusionThis study provides a new theoretical foundation for the anti-tumor application of Garcinia oblongifolia and confirms that isogarcinol could be developed as a candidate drug for NPC treatment with low toxicity.

KDM4C represses liver fibrosis by regulating H3K9me3 methylation of ALKBH5 and m6A methylation of snail1 mRNA.

We aimed to disclose the molecular mechanism of snail1 in liver fibrosis. Carbon tetrachloride (CCl4) was used to induce a liver fibrosis model in mice whereby serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were evaluated, and liver pathological alternations were assessed. Rat hepatic stellate cells (HSC-T6) were irritated with transforming growth factor (TGF)-β1, followed by assessment of cell viability and migration. The levels of snail1, ALKBH5, and lysine specific demethylase 4C (KDM4C) were quantified by immunohistochemistry, western blot, or reverse transcription-quantitative polymerase chain reaction, in addition to α-smooth muscle actin (SMA), anti-collagen type I α1 (COL1A1), vimentin, and E-cadherin. Photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation and RNA stability were evaluated to determine the relationship between ALKBH5 and snail1. Changes in KDM4C-bound ALKBH5 promoter and enrichment of histone H3 lysine 9 trimethylation (H3K9me3) at the ALKBH5 promoter were determined using chromatin immunoprecipitation. In fibrosis mice, snail1 was upregulated while ALKBH5 and KDM4C were downregulated. KDM4C overexpression reduced serum ALT and AST levels, liver injury, and α-SMA, COL1A1 and VIMENTIN expressions but increased E-cadherin expression. However, the aforementioned trends were reversed by concurrent overexpression of snail1. In HSC-T6 cells exposed to TGF-β1, ALKBH5 overexpression weakened cell viability and migration, downregulated α-SMA, COL1A1 and VIMENTIN, upregulated E-CADHERIN, and decreased m6A modification of snail1 and its mRNA stability. KDM4C increased ALKBH5 expression by lowering H3K9me3 level, but inhibited HSC-T6 cell activation by regulating the ALKBH5/snail1 axis. KDM4C decreases H3K9me3 methylation to upregulate ALKBH5 and subsequently inhibits snail1, ultimately impeding liver fibrosis.

Impact of Prospero Homeobox-1 (PROX-1) οn the Oncogenic Phenotypes of Hepatocellular Carcinoma Cells.

Transcriptional factor prospero homeobox-1 (PROX-1) is crucial for the embryonic development of various organs and cell fate specification. It exhibits either an oncogenic or tumor suppressive activity depending on cancer types. However, the relationship between PROX-1 and hepatocellular carcinoma (HCC) remains obscure. This study was conducted to investigate the effect of PROX-1 on the invasive and oncogenic phenotypes of human HCC cells. The effect of PROX-1 on tumor cell behavior was investigated by using a pcDNA-myc vector and a small interfering RNA in HepG2 and Huh7 human HCC cell lines. Flow cytometry, migration, invasion, proliferation, and tube formation assays were performed. PROX-1 expression in human HCC cells was explored by western blotting. PROX-1 overexpression enhanced tumor cell proliferation and inhibited apoptosis and cell cycle arrest by modulating the activities of caspase-3, PARP, and cyclin-dependent kinase inhibitors, including p21, p27, and p57 in HCC cells. After PROX-1 overexpression, the number of migrating and invading HCC cells significantly increased, and the expression levels of N-cadherin and Snail increased in HCC cells. PROX-1 overexpression enhanced angiogenesis through increased VEGF-A and VEGF-C expression and decreased angiostatin expression. PROX-1 overexpression also increased the phosphorylation of glycogen synthase kinase-3β (GSK-3β) and forkhead box O1 (FOXO1) in HCC cells. After PROX-1 knockdown, their phosphorylation was reversed. PROX-1 overexpression is associated with the invasive and oncogenic phenotypes of human HCC cells via GSK-3β and FOXO1 phosphorylation.

CircSOD2: Disruption of intestinal mucosal barrier function in ulcerative colitis by regulating the miR-378g/Snail1 axis.

Circular RNA (circRNA) has been found to mediate ulcerative colitis (UC) progression by regulating intestinal mucosal barrier function. However, the role of circSOD2 in UC process and its underlying molecular mechanism still need to be further elucidated. Lipopolysaccharide (LPS)-induced Caco2 cells were used to mimic UC cell models. CircSOD2, miR-378g, and Snail1 levels were determined by quantitative real-time PCR. Cell viability was detected using MTT assay, and inflammatory cytokine levels were measured using ELISA. The intestinal mucosal barrier function was evaluated by testing transepithelial electrical resistance and fluorescein isothiocyanate (FITC)-dextran permeability. Snail1 and tight junction-related markers (Zo-1 and Claudin2) protein levels were examined using western blot. The interaction between miR-378g and circSOD2 or Snail1 was confirmed by dual-luciferase reporter assay. Dextran sulfate sodium (DSS) was used to induce UC rat models in vivo. CircSOD2 was overexpressed in UC patients, and its knockdown significantly increased cell viability, transepithelial electrical resistance, and tight junction-related protein expression, while reduced inflammation cytokine levels and the permeability of FITC-dextran in LPS-induced Caco2 cells. In terms of mechanism, circSOD2 sponged miR-378g to positively regulate Snail1 expression. MiR-378g inhibitor reversed the effect of circSOD2 knockdown on intestinal mucosal barrier injury and Snail1 expression in LPS-induced Caco2 cells. In DSS-induced UC rat models, circSOD2 knockdown also could repair the intestinal mucosal barrier injury through regulating miR-378g/Snail1 axis. CircSOD2 could destroy intestinal mucosal barrier function in LPS-induced Caco2 cells and DSS-induced UC rats by miR-378g/Snail1 axis.

CD146 Promotes EMT-Mediated Migration and Invasion of NSCLC via PI3K/Akt Signaling Pathway.

Recurrence and metastasis are the main causes of non-small cell lung cancer (NSCLC)-related death. CD146 has been identified as a potential risk factor for poor prognosis, closely related to the distant metastasis and drug resistance in various cancers. However, the clinical significance of CD146 in NSCLC requires further investigation. This study explored the correlation between CD146 expression and clinical variables using tumor tissue samples collected from our hospital. CD146 expression levels in NSCLC cell lines and tissues were assessed and compared using immunohistochemistry, real-time polymerase chain reaction (RT-qPCR), flow cytometry, and western blot analysis. The invasion and migration capabilities of tumor cells were determined using transwell and wound healing assays. The levels of proteins related to epithelial-mesenchymal transition (EMT) as well as the underlying PI3K/Akt signaling pathway was measured by western blotting. We discovered that CD146 expression is significantly associated with the EMT signaling pathway. High CD146 expression predicted lymph node metastasis, metastasis to distant organs, advanced Tumor, Node, Metastasis (TNM) staging, and poor survival in NSCLC patients. Wound healing and transwell assays showed that knocking down CD146 significantly suppressed cell migration along with cell invasion in NSCLC, whereas overexpressing CD146 notably enhanced these processes. Western blot analysis revealed significantly reduced levels of N-cadherin, vimentin, snail, twist, PI3K, and AKT phosphorylation in shCD146 H460 cells compared to vector control cells. Treatment with PI3K inhibitor PI3K-IN-1 increased E-cadherin expression levels but reduced N-cadherin, Twist, Vimentin, PI3K, and AKT phosphorylation levels in pcDNA3.1-CD146 A549 cells compared with the vector control cells. CD146 expression acts as a prognostic risk factor for adverse outcomes in NSCLC, promoting invasion and metastasis by activating the EMT through the PI3K/Akt signaling pathway. These findings underscore the potential therapeutic strategies targeting CD146, offering new treatment options for NSCLC patients, especially those at risk of metastasis.

Shrimp Lipids Inhibit Migration, Epithelial-Mesenchymal Transition, and Cancer Stem Cells via Akt/mTOR/c-Myc Pathway Suppression.

Shrimp is a rich source of bioactive molecules that provide health benefits. However, the high cholesterol content in shrimp oil may pose a risk. We utilized the cholesterol elimination method to obtain cholesterol-free shrimp lipids (CLs) and investigated their anticancer potential, focusing on cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT). Our study focused on CSCs and EMT, as these factors are known to contribute to cancer metastasis. The results showed that treatment with CLs at doses ranging from 0 to 500 µg/mL significantly suppressed the cell migration ability of human lung cancer (H460 and H292) cells, indicating its potential to inhibit cancer metastasis. The CLs at such concentrations did not cause cytotoxicity to normal human keratinocytes. Additionally, CL treatment was found to significantly reduce the levels of Snail, Slug, and Vimentin, which are markers of EMT. Furthermore, we investigated the effect of CLs on CSC-like phenotypes and found that CLs could significantly suppress the formation of a three-dimensional (3D) tumor spheroid in lung cancer cells. Furthermore, CLs induced apoptosis in the CSC-rich population and significantly depleted the levels of CSC markers CD133, CD44, and Sox2. A mechanistic investigation demonstrated that exposing lung cancer cells to CLs downregulated the phosphorylation of Akt and mTOR, as well as c-Myc expression. Based on these findings, we believe that CLs may have beneficial effects on health as they potentially suppress EMT and CSCs, as well as the cancer-potentiating pathway of Akt/mTOR/c-Myc.

Abstract 207: Tumor suppressive role of NKX2-1 in advanced thyroid cancer progression

Abstract NKX2-1 is a homeodomain transcription factor, known as a master regulator of thyroid development. NKX2-1 is also crucial for lung epithelium differentiation, and the involvement of NKX2-1 in lung carcinogenesis and cancer progression has been intensely investigated. However, the role of NKX2-1 in thyroid cancer progression remains elusive. The Cancer Genome Atlas (TCGA) dataset analysis demonstrated that papillary thyroid cancer (PTC) patients with low NKX2-1 mRNA expression had significantly poorer prognosis than those with a combination of intermediate and high mRNA expression of NKX2-1. Lentivirus-transduced tetracycline (Tet)-inducible system was used to achieve NKX2-1 overexpression in advanced follicular thyroid cancer (FTC) cell lines, FTC-238 and WRO, and an anaplastic thyroid cancer (ATC) cell line 8305C, in which NKX2-1 expression is barely/not detected. All these thyroid cancer cell lines showed significant suppression of cell proliferation with NKX2-1 overexpression. In addition, NKX2-1 overexpression inhibited migration of FTC-238 cells. The levels of mRNA and protein expression of mesenchymal markers, matrix metalloproteinase-2 (MMP-2) and fibronectin, were decreased by NKX2-1 overexpression in FTC-238 cells, suggesting a possibility that NKX2-1 partially inhibits epithelial-mesenchymal transition (EMT). SNAIL and SLUG are essential EMT transcription factors involved in metastasis in cancer progression. NKX2-1 mRNA expression was significantly lower in high SNAI1 (encoding SNAIL) expressing PTC in TCGA database. Indeed, suppression of SNAIL protein expression was found upon overexpression of NKX2-1 in FTC-238 cells which naturally express high level of SNAIL. These findings suggest that NKX2-1 may inhibit the migration of advanced thyroid cancer cells through SNAIL-induced EMT. Similarly, suppression of SLUG protein expression by overexpression of NKX2-1 was observed in WRO and 8305C cells which express high level of SLUG protein. Whether NKX2-1 overexpression inhibits migration and invasion of WRO and 8305C cells through SLUG-induced EMT is currently under examination. The Tet-inducible NKX2-1 expressing thyroid cancer cells will be used for in vivo evaluation of their metastatic ability using an immunocompromised mouse model. The findings so far suggest that NKX2-1 exerts a tumor suppressive activity in advanced thyroid cancers through suppression of cell proliferation, and cell migration presumably via suppression of EMT transcription factors. Citation Format: Yo-Taro Shirai, Shioko Kimura. Tumor suppressive role of NKX2-1 in advanced thyroid cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 207.

Abstract 5390: Exploring signaling pathways of tumor-nerve interactions in prostate and breast cancer

Abstract A significant portion of prostate cancer (PCa) and breast cancer (BCa) patients develop bone metastatic disease. In some cases, cancer spreads through the nervous system, a process known as perineural invasion (PNI). Neurite outgrowth is believed to be a precursor to PNI. Snail is an important gene which regulates the epithelial-mesenchymal transition (EMT) process in which tumor cells at the invasive front undergo this transition to promote invasion, migration, and subsequent metastasis. We recently published that Snail promotes neurite outgrowth in PCa cells. We hypothesize that Snail expression will stimulate neurite outgrowth in both PCa and BCa cells through extracellular vesicles from cancer cells interacting with neurons. To test this hypothesis, we first collected conditioned media from PCa and BCa cells expressing Snail and isolated exosomes. Exosomal markers were detected using western blot to confirm the isolated exosomes. Additionally, we used Transmission Electron Microscopy (TEM) to observe the secretion of exosomes. Proteomics was performed to analyze proteins expressed within exosomes of LNCaP Snail overexpressing or C4-2 Snail knockdown PCa cells. Our results showed that Snail-expressing cells secrete exosomes containing Talin1, specifically, the proteolyzed C-terminal rod domain, while full-length Talin1 is found in whole cell lysates from Snail-expressing cells. Talin1 has previously been associated with neurite outgrowth. Neurite outgrowth assays were then performed using conditioned medium collected from C4-2 PCa cells with Snail knockdown and MCF-7 BCa cells with Snail overexpression. Increased neurite outgrowth is observed in PC-12 cells and NPC (Induced Pluripotent Stem Cells differentiated neuronal progenitor cells) when cultured with conditioned medium collected from PCa and BCa cells expressing high levels of Snail. AKT activation was observed in the neuronal cells in response to conditioned media from Snail-expressing cells. Furthermore, we found that mH4, a proprietary small molecule inhibitor of Talin1, reduces Snail-mediated neurite outgrowth and AKT activation (p-AKT Thr308 and Ser473). Overall, we have uncovered a pathway whereby Snail transcription factor promotes secretion of exosomes containing Talin1 which promotes AKT signaling in neuronal cells and neurite outgrowth. Talin1 small molecule inhibitor shows promise for therapeutic targeting of tumor-nerve interactions. Acknowledgements: The authors acknowledge the use of core facilities supported by the National Institute on Minority Health and Health Disparities through grant number 5U54MD013376 and 1U54GM128729-01-DaCCoTA Scholars Program (PI: Rezvani) National Institute of General Medical Sciences (NIGMS). Citation Format: Bor-Jang Hwang, Gabrielle J. Edwards, Cole Davis Knoblich, Khosrow Rezvani, Valerie Odero-Marah. Exploring signaling pathways of tumor-nerve interactions in prostate and breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5390.

Abstract 5414: BDNF/TrKB signaling may lead to higher incidence of perineural invasion in men with prostate cancer

Abstract Perineural invasion (PNI) is a crucial mechanism facilitating prostate cancer metastasis. PNI encompasses perineural, circumferential, and intraneural invasion, with cancer cells closely interacting with nerves. Evidence suggests that cancer cells utilize the nervous system for metastasis through signaling pathways. PNI is associated with poor prognoses in various cancers, but its role in prostate cancer remains unclear. PCa primarily metastasizes through systemic routes, such as lymphatic and circulatory systems. Metastasizing cancer cells undergo epithelial-mesenchymal transition (EMT), enhancing their motility. SNAIL1, a transcriptional repressor, induces EMT and promotes cancer cell migration, including towards nerves, termed neurite outgrowth. Neurite outgrowth involves intricate signaling between tumor cells and nerves, possibly facilitating cancer cell infiltration into nerve sheaths and PNI. Our lab has shown SNAIL1 in interactions with neurotrophic factors like Brain-Derived Neurotrophic Factor (BDNF) and Tyrosine Kinase Receptor Beta (TrkB), modulating cancer cell behavior. TrkB is overexpressed in various cancers, while BDNF signaling contributes to EMT via the Twist-Snail axis. BDNF may also play a role in PNI pathogenesis. Our hypothesis posits the BDNF-TrkB axis drives aggressive prostate cancer and PNI. This study employed prostate cancer cell lines for comprehensive analysis. We assessed BDNF expression in different cell lines, particularly those with high Snail levels, and analyzed BDNF transcript levels via real-time quantitative PCR following RNA extraction and reverse transcription. We explored whether BDNF overexpression enhanced cancer cell migration towards nerves, employing migration assays. Our findings indicated heightened migration in BDNF-high cell lines, C42, PC3, and MDA-2b, compared to BDNF knockdown cells. Additionally, a TrkB inhibitor, K252a, attenuated migration due to BDNF-induced TrkB phosphorylation. Our study establishes that BDNF/TrkB signaling promotes prostate cancer cell migration towards nerves, a phenomenon reversible with K252a, offering a potential strategy to impede prostate cancer progression and metastasis. Citation Format: Gabrielle Joy Edwards, Valerie Odero-Marah. BDNF/TrKB signaling may lead to higher incidence of perineural invasion in men with prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5414.

Metabolic landscape of human alveolar type II epithelial cells undergoing epithelial-mesenchymal transition induced directly by silica exposure

Epithelial-mesenchymal transition (EMT) plays an irreplaceable role in the development of silicosis. However, molecular mechanisms of EMT induced by silica exposure still remain to be addressed. Herein, metabolic profiles of human alveolar type II epithelial cells (A549 cells) exposed directly to silica were characterized using non-targeted metabolomic approaches. A total of 84 differential metabolites (DMs) were identified in silica-treated A549 cells undergoing EMT, which were mainly enriched in metabolisms of amino acids (e.g., glutamate, alanine, aspartate), purine metabolism, glycolysis, etc. The number of DMs identified in the A549 cells obviously increased with the elevated exposure concentration of silica. Remarkably, glutamine catabolism was significantly promoted in the silica-treated A549 cells, and the levels of related metabolites (e.g., succinate) and enzymes (e.g., α-ketoglutarate (α-KG) dehydrogenase) were substantially up-regulated, with a preference to α-KG pathway. Supplementation of glutamine into the cell culture could substantially enhance the expression levels of both EMT-related markers and Snail (zinc finger transcription factor). Our results suggest that the EMT of human alveolar epithelial cells directly induced by silica can be essential to the development of silicosis.

Plumbagin Regulates Snail to Inhibit Hepatocellular Carcinoma Epithelial-Mesenchymal Transition in vivo and in vitro.

Plumbagin (PL) has been shown to effe ctively inhibit autophagy, suppressing invasion and migration of hepatocellular carcinoma (HCC) cells. However, the specific mechanism remains unclear. This study aimed to investigate the effect of PL on tumor growth factor (TGF)-β-induced epithelial-mesenchymal transition (EMT) in HCC. Huh-7 cells were cultured, and in vivo models of EMT and HCC-associated lung metastasis were developed through tail vein and in situ injections of tumor cells. In vivo imaging and hematoxylin and eosin staining were used to evaluate HCC modeling and lung metastasis. After PL intervention, the expression levels of Snail, vimentin, E-cadherin, and N-cadherin in the liver were evaluated through immunohistochemistry and Western blot. An in vitro TGF-β-induced cell EMT model was used to detect Snail, vimentin, E-cadherin, and N-cadherin mRNA levels through a polymerase chain reaction. Their protein levels were detected by immunofluorescence staining and Western blot. In vivo experiments demonstrated that PL significantly reduced the expression of Snail, vimentin, and N-cadherin, while increasing the expression of E-cadherin at the protein levels, effectively inhibiting HCC and lung metastasis. In vitro experiments confirmed that PL up-regulated epithelial cell markers, down-regulated mesenchymal cell markers, and inhibited EMT levels in HCC cells. PL inhibits Snail expression, up-regulates E-cadherin expression, and down-regulates N-cadherin and vimentin expression, preventing EMT in HCC cells and reducing lung metastasis.