Metastasis In Nude Mice Research Articles

EZH2 Promotes Glioma Cell Proliferation, Invasion, and Migration via Mir-142-3p/KCNQ1OT1/HMGB3 Axis : Running Title: EZH2 Promotes Glioma cell Malignant Behaviors.

This study investigates the role and molecular mechanism of EZH2 in glioma cell proliferation, invasion, and migration. EZH2, miR-142-3p, lncRNA KCNQ1OT1, LIN28B, and HMGB3 expressions in glioma tissues and cells were determined using qRT-PCR or Western blot, followed by CCK-8 assay detection of cell viability, Transwell detection of invasion and migration, ChIP analysis of the enrichment of EZH2 and H3K27me3 on miR-142-3p promoter, dual-luciferase reporter assay and RIP validation of the binding of miR-142-3p-KCNQ1OT1 and KCNQ1OT1-LIN28B, and actinomycin D detection of KCNQ1OT1 and HMGB3 mRNA stability. A nude mouse xenograft model and a lung metastasis model were established. EZH2, KCNQ1OT1, LIN28B, and HMGB3 were highly expressed while miR-142-3p was poorly expressed in gliomas. EZH2 silencing restrained glioma cell proliferation, invasion, and migration. EZH2 repressed miR-142-3p expression by elevating the H3K27me3 level. miR-142-3p targeted KCNQ1OT1 expression, and KCNQ1OT1 bound to LIN28B to stabilize HMGB3 mRNA, thereby promoting its protein expression. EZH2 silencing depressed tumor growth and metastasis in nude mice via the miR-142-3p/KCNQ1OT1/HMGB3 axis. In conclusion, EZH2 curbed miR-142-3p expression, thereby relieving the inhibition of KCNQ1OT1 expression by miR-142-3p, enhancing the binding of KCNQ1OT1 to LIN28B, elevating HMGB3 expression, and ultimately accelerating glioma cell proliferation, invasion, and migration.

Insight into prostate cancer osteolytic metastasis by RelB coordination of IL-8 and S100A4.

Although RANK-LRANK interaction is essential for osteoclastogenesis, the mechanisms by which cancer cells invade bone tissues and initiate osteolytic metastasis remain unclear. Here, we show that the hyperactivation of RelB fosters prostate cancer (PCa) osteolytic metastasis by coordinating interleukin-8 (IL-8) and calcium-binging protein A4 (S100A4). The factors promoting PCa bone metastasis were investigated in sera from PCa patients and tumour tissues derived from nude mice using immunohistochemical analysis and enzyme-linked immunosorbent assays (ELISA). Cell mobility and mineralization were quantified using BioStation CT and Osteolmage assay. The relative cistrome was investigated in advanced PCa cells by standard transcriptional analyses, including the luciferase reporter response, site-directed mutagenesis, and chromatin immunoprecipitation (ChIP) assay. PCa cell-initiated tumour formation, expansion, and bone metastasis were validated in mice using multiple approaches, including orthotopic, intraskeletal, and caudal arterial implantation models. IL-8 and S100A4 correlated with patient Gleason scores and bone metastasis. RelB upregulated IL-8, facilitating androgen receptor (AR)-independent growth. RelB-Sp1 interaction enhanced epithelial-mesenchymal transition (EMT) by activating Snail and Twist. RelB-NFAT1c super-enhancer upregulated S100A4 in the organization of the cytoskeleton and bone metastasis. The RelB-IL-8-S100A4 signalling axis was confirmed to promote osteolytic metastasis in nude mice. RelB-IL-8 reciprocally promoted EMT by activating inflammatory signalling and inactivating AR signalling. IL-8 is essential for provoking PCa metastasis but insufficient to drive bone metastasis. IL-8-S100A4 cooperation was necessary for metastatic cells to target the bone. RelB activates inflammatory signalling by upregulating IL-8 and suppressing AR. RelB upregulates S100A4 by cooperating with NFATC1. IL-8 boosts EMT by activating Snail 1 and Twist 1, and S100A4 exacerbates osteolytic metastasis via calcium consumption. RelB harnesses IL-8 and S100A4 to drive PCa osteolytic metastasis.

TGF-β-induced lncRNA TBUR1 promotes EMT and metastasis in lung adenocarcinoma via hnRNPC-mediated GRB2 mRNA stabilization

The transforming growth factor-β (TGF-β) signaling pathway is pivotal in inducing epithelial-mesenchymal transition (EMT) and promoting cancer metastasis. Long non-coding RNAs (lncRNAs) have emerged as significant players in these processes, yet their precise mechanisms remain elusive. Here, we demonstrate that TGF-β-upregulated lncRNA 1 (TBUR1) is significantly activated by TGF-β via Smad3/4 signaling in lung adenocarcinoma (LUAD) cells. Functionally, TBUR1 triggers EMT, enhances LUAD cell migration and invasion in vitro, and promotes metastasis in nude mice. Mechanistically, TBUR1 interacts with heterogeneous nuclear ribonucleoprotein C (hnRNPC) to stabilize GRB2 mRNA in an m6A-dependent manner. Clinically, TBUR1 is upregulated in LUAD tissues and correlates with poor prognosis, highlighting its potential as a prognostic biomarker and therapeutic target for LUAD. Taken together, our findings underscore the crucial role of TBUR1 in mediating TGF-β-induced EMT and metastasis in LUAD, providing insights for future therapeutic interventions.

Acetylation-dependent deubiquitinase USP26 stabilizes BAG3 to promote breast cancer progression

Deubiquitylases (DUBs) have emerged as promising targets for cancer therapy due to their role in stabilizing substrate proteins within the ubiquitin machinery. Here, we identified ubiquitin-specific protease 26 (USP26) as an oncogene via screening prognostic DUBs in breast cancer. Through in vitro and in vivo experiments, we found that depletion of USP26 inhibited breast cancer cell proliferation and invasion, and suppressed tumor growth and metastasis in nude mice. Further investigation identified co-chaperone Bcl-2-associated athanogene 3 (BAG3) as the direct substrate of USP26, and ectopic expression of BAG3 partially reversed antitumor effect induced by USP26 knockdown. Mechanistically, the lysine acetyltransferase Tip60 targeted USP26 at K134 for acetylation, which enhanced USP26 binding affinity to BAG3, leading to BAG3 deubiquitination and increased protein stability. Importantly, we employed a structure-based virtual screening and discovered a drug-like molecule called 5813669 that targets USP26, destabilizing BAG3 and effectively mitigating tumor growth and metastasis in vivo. Clinically, high expression levels of USP26 were correlated with elevated BAG3 levels and poor prognosis in breast cancer patients. Overall, our findings highlight the critical role of USP26 in BAG3 protein stabilization and provide a promising therapeutic target for breast cancer.

Targeting the ZMIZ1-Notch1 signaling axis for the treatment of tongue squamous cell carcinoma

Zinc finger MIZ-type containing 1 (ZMIZ1) is a transcriptional coactivator related to the protein inhibitors of activated STATs (PIAS) family. Mounting evidence suggests that ZMIZ1 plays a crucial role in the occurrence and development of cancers. The function of ZMIZ1 in tongue squamous cell carcinoma (TSCC) and the mechanisms underpinning its role in this disease have not been fully clarified. We performed qualitative ZMIZ1 protein expression analyses using immunohistochemistry in 20 patient-derived, paraffin-embedded TSCC tissue sections. We used RNAi to knock down ZMIZ1 expression in the CAL-27 TSCC cell line and quantified the impact of ZMIZ1 knock down on proliferation, migration and apoptosis via CCK-8, scratch assay and flow cytometry, respectively. We used qRT-PCR and western blotting to investigate the role of ZMIZ1 in this cell line. Finally, we established a model of lung metastasis in nude mice to replicate the in vitro results. ZMIZ1 protein was significantly more abundant in TSCC case tissue samples. ZMIZ1 knockdown reduced the invasion and metastases of TSCC tumor cells and promoted apoptosis. ZMIZ1 knockdown was associated with the down-regulation of Notch signaling pathway related factors Jagged1 and Notch1, and invasion and metastasis related factors MKP-1, SSBP2 and MMP7 in vitro and in vivo, at the mRNA level. In vitro and in vivo data suggest that knock down of ZMIZ1 may inhibit TSCC invasion and metastasis by modulating Notch signaling. ZMIZ1 inhibition may therefore represent a new therapeutic target for TSCC.

IL-1β promotes esophageal squamous cell carcinoma growth and metastasis through FOXO3A by activating the PI3K/AKT pathway

Esophageal cancer is a common type of cancer that poses a significant threat to human health. While the pro-inflammatory cytokine IL-1β has been known to contribute to the development of various types of tumors, its role in regulating esophageal cancer progression has not been extensively studied. Our studies found that the expression of IL-1β and FOXO3A was increased in esophageal squamous cell carcinoma (ESCC). IL-1β not only increased the proliferation, migration, and invasion of two ESCC cell lines but also promoted tumor growth and metastasis in nude mice. We also observed that IL-1β and FOXO3A regulated the process of epithelial-mesenchymal transition (EMT) and autophagy. The PI3K/AKT pathway was found to be involved in the changes of FOXO3A with the expression level of IL-1β. The AKT agonist (SC79) reversed the reduction of FOXO3A expression caused by the knockdown of IL-1β, indicating that IL-1β plays a role through the PI3K/AKT/FOXO3A pathway. Furthermore, the knockdown of FOXO3A inhibited ESCC development and attenuated the pro-cancer effect of overexpressed IL-1β. Targeting IL-1β and FOXO3A may be potentially valuable for the diagnosis and treatment of ESCC.

Abstract 4139: Prolyl 4-hydroxylase subunit alpha 1 acts as a novel target for lung adenocarcinoma brain metastasis

Abstract Lung cancer is the most lethal cancer worldwide, with a high incidence of distant metastasis. Many lung adenocarcinoma (LUAD) patients experience brain metastasis during the disease process with unfavorable prognosis. Our previous study has discovered that P4HA1 was exclusively upregulated in brain metastatic cells. Through the analysis of single-cell RNA sequencing of LUAD samples, we found that the expression of P4HA1 in brain metastatic tumor cells is higher than that in primary tumor cells. This finding was further confirmed by immunohistochemical staining. Significantly, a strong presence of P4HA1 in primary tumors is associated with a reduced duration of disease-free survival in individuals with LUAD. Overexpression of P4HA1 in A549 and PC9 cell lines significantly increased the incidence of brain metastasis in BALB/c nude mice, whereas knockdown of P4HA1 in high brain metastatic cells significantly decreased the incidence of brain metastasis and reduced the tumor foci in brain with improved survival. Utilization of DHB, a P4HA1 inhibitor, exerts both therapeutic and preventive effects in relieving brain metastases in nude mice. Furthermore, remarkable inhibition of tumor growth by DHB was observed in patient derived xenograft (PDX) models. RNA sequencing analysis demonstrated that the reduction of P4HA1 expression had a substantial impact on cell adhesion and extracellular matrix (ECM)-receptors interactions. Western blotting analysis verified that the decrease in P4HA1 expression led to a drop in the expression of adhesion molecules ICAM1, VCAM1, NCAM1, as well as integrin molecules ITGA2 and ITGA3. Furthermore, when endothelial cells were co-cultured with conditioned medium from tumor cells, it was observed that the expression of the tight junction molecule ZO1 was reduced after co-culturing with conditioned medium from P4HA1 knockdown A549 cells. The results from the in vitro blood-brain barrier (BBB) model and in vivo biofluorescence imaging indicate that P4HA1 promoted brain metastasis of LUAD via modulating the ability of tumor cells to cross the blood-brain barrier. In conclusion, our study reveals that overexpression of P4HA1 promotes metastatic spread to the brain, and targeting P4HA1 could be a promising therapeutic strategy for the treatment of lung adenocarcinoma brain metastasis. Citation Format: Yan He, Zhenyu Luo, Yucheng Dong, Rui Wan, Xue Zhang, Hua Bai, Jie Wang. Prolyl 4-hydroxylase subunit alpha 1 acts as a novel target for lung adenocarcinoma brain metastasis [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 4139.

Circ_0007534 promotes cholangiocarcinoma stemness and resistance to anoikis through DDX3X-mediated positive feedback regulation of parental gene DDX42

Cholangiocarcinoma (CCA) is a malignancy with an extremely poor prognosis, and much remains unknown about its pathogenesis and treatment modalities. Circular RNA (circRNA) has been proven to play regulatory roles in various tumorigenesis, yet its potential function and mechanism in cholangiocarcinoma require further investigation. This study is the first to identify the aberrant expression and functional role of a novel circRNA, circ_0007534, derived from the DDX42 gene, in cholangiocarcinoma. Compared to the normal control group, the expression of circ_0007534 was significantly elevated in the tissues and cells with CCA and that high expression correlated with lymph node invasion and poor prognosis. Functional experiments indicated that downregulating circ_0007534 markedly inhibited the proliferation, migration, invasion, stemness, and anti-anoikis ability of CCA cells, as well as the tumor growth and liver and lung metastasis in nude mice. Mechanistic studies revealed that DDX42, as the parent gene of circ_0007534, can mutually regulate each other's expression. Predominantly located in the cytoplasm, circ_0007534 can form a complex with the RNA-binding protein DDX3X, which enhances the stability of DDX42 mRNA, thereby upregulating the expression of DDX42. This creates a positive feedback loop among the three, collectively promoting the progression of cholangiocarcinoma. In conclusion, this study sheds light on the pivotal role and molecular mechanism of circ_0007534 in the development of CCA, offering potential new targets for early diagnosis and treatment.

EIF4A3-negatively driven circular RNA β-catenin (circβ-catenin) promotes colorectal cancer progression via miR-197-3p/CTNND1 regulatory axis.

Circβ-catenin, our first reported circRNA, has been reported to mediate tumorigenesis in various cancers. However, its biological functions and underlying mechanisms in colorectal cancer (CRC) remain unknown. The qRT-PCR examination was used to detect the expression of circβ-catenin, miR-197-3p, and CTNND1 in cells and human tissues. Western blot was conducted to detect the protein expression levels. The biological function of circβ-catenin was verified by MTT, colony formation, wound healing, and transwell assays. The in vivo effects of circβ-catenin were verified by nude mice xenograft and metastasis models. The regulatory network of circβ-catenin/miR-197-3p/CTNND1 was confirmed via dual-luciferase reporter and RIP assays. In the present study, circβ-catenin was found to promote CRC cell proliferation and metastasis in vitro and in vivo. Mechanistically, circβ-catenin served as miRNA decoy to directly bind to miR-197-3p, then antagonized the repression of the target gene CTNND1, and eventually promoted the malignant phenotype of CRC. More interestingly, the inverted repeated Alu pairs termed AluJb1/2 and AluY facilitated the biogenesis of circβ-catenin, which could be partially reversed by EIF4A3 binding to Alu element AluJb2. Our findings illustrated a novel mechanism of circβ-catenin in modulating CRC tumorigenesis and metastasis, which provides a potential therapeutic target for CRC patients.

A novel peptide PDHK1-241aa encoded by circPDHK1 promotes ccRCC progression via interacting with PPP1CA to inhibit AKT dephosphorylation and activate the AKT-mTOR signaling pathway

BackgroundClear cell renal cell carcinoma (ccRCC) is the most prevalent kidney cancer with high aggressive phenotype and poor prognosis. Accumulating evidence suggests that circRNAs have been identified as pivotal mediators in cancers. However, the role of circRNAs in ccRCC progression remains elusive.MethodsThe differentially expressed circRNAs in 4 paired human ccRCC and adjacent noncancerous tissues ccRCC were screened using circRNA microarrays and the candidate target was selected based on circRNA expression level using weighted gene correlation network analysis (WGCNA) and the gene expression omnibus (GEO) database. CircPDHK1 expression in ccRCC and adjacent noncancerous tissues (n = 148) were evaluated along with clinically relevant information. RT-qPCR, RNase R digestion, and actinomycin D (ActD) stability test were conducted to identify the characteristics of circPDHK1. The subcellular distribution of circPDHK1 was analyzed by subcellular fractionation assay and fluorescence in situ hybridization (FISH). Immunoprecipitation-mass spectrometry (IP-MS) and immunofluorescence (IF) were employed to evaluate the protein-coding ability of circPDHK1. ccRCC cells were transfected with siRNAs, plasmids or lentivirus approach, and cell proliferation, migration and invasion, as well as tumorigenesis and metastasis in nude mice were assessed to clarify the functional roles of circPDHK1 and its encoded peptide PDHK1-241aa. RNA-sequencing, western blot analysis, immunoprecipitation (IP) and chromatin immunoprecipitation (ChIP) assays were further employed to identify the underlying mechanisms regulated by PDHK1-241aa.ResultsCircPDHK1 was upregulated in ccRCC tissues and closely related to WHO/ISUP stage, T stage, distant metastasis, VHL mutation and Ki-67 levels. CircPDHK1 had a functional internal ribosome entry site (IRES) and encoded a novel peptide PDHK1-241aa. Functionally, we confirmed that PDHK1-241aa and not the circPDHK1 promoted the proliferation, migration and invasion of ccRCC. Mechanistically, circPDHK1 was activated by HIF-2A at the transcriptional level. PDHK1-241aa was upregulated and interacted with PPP1CA, causing the relocation of PPP1CA to the nucleus. This thereby inhibited AKT dephosphorylation and activated the AKT-mTOR signaling pathway.ConclusionsOur data indicated that circPDHK1-encoded PDHK1-241aa promotes ccRCC progression by interacting with PPP1CA to inhibit AKT dephosphorylation. This study provides novel insights into the multiplicity of circRNAs and highlights the potential use of circPDHK1 or PDHK1-241aa as a therapeutic target for ccRCC.

ENO2 promotes anoikis resistance in anaplastic thyroid cancer by maintaining redox homeostasis.

Anoikis presents a significant barrier in the metastasis of cancer. As the most aggressive type of thyroid cancer, anaplastic thyroid cancer (ATC) exhibits a high risk of metastasis and is characterized by high mortality. Therefore, investigating the molecular mechanisms of anoikis resistance in ATC is important for devising therapeutic targets in clinical research. Differentially Expressed Genes were screened in ATC cells under attached and detached culture conditions with RNA-seq. Investigate the impact of enolase 2 (ENO2) on apoptosis and spheroid formation by gain and loss of function. Changes of reactive oxygen species (ROS), glutathione (GSH) and nicotinamide adenine dinucleotide phosphate (NADPH) were detected to assess redox balance. The transcriptional regulatory role of signal transducer and activator of transcription 1 (STAT1) on ENO2 was validated through Dual-Luciferase Reporter Gene Assay. Explore the impact of ENO2 expression on the formation of lung metastases in nude mice. We found that the glycolysis process was activated in detached ATC cells. Several genes in the glycolysis process, particularly ENO2, a member of the enolase superfamily was upregulated in ATC cells cultured in suspension. The upregulation of ENO2 enabled the maintenance of redox balance by supplying GSH and NADPH, thereby preventing cells from undergoing anoikis. In terms of mechanism, the expression of STAT1 was enhanced in anoikis resistance cells, which in turn positively regulated the expression of ENO2. In vivo, ENO2-suppressed ATC cells resulted in a significantly lower rate of lung colonization compared to control ATC cells. Stable expression of ENO2 and the maintenance of redox balance played a pivotal role in facilitating anoikis resistance of ATC.

Hu-Qi-Zheng-Xiao Decoction Inhibits the Metastasis of Hepatocellular Carcinoma Cells by Suppressing the HIF-1α Signaling Pathway to Inhibit EMT, LCSC, and Angiogenic Process.

Hepatocellular carcinoma (HCC) is a common clinical malignant tumor of the digestive system. Hu-Qi-Zheng-Xiao (HQZX) decoction has been clinically found to prolong the survival of patients with hepatocellular carcinoma and improve the quality of patients' survival, but its antitumor biological mechanism is still unclear. A nude mouse hollow fiber hepatocellular carcinoma model was constructed to analyze the in vivo efficacy of HQZX decoction against 7 different hepatocellular carcinoma cells. The subcutaneous graft tumor model was again validated. In vitro, the effect of HQZX decoction on the growth and metastasis of the cell line with the highest growth inhibition was evaluated. The cell line with the best efficacy response screened was again used to construct a hollow fiber hepatocellular carcinoma model and hollow fiber conduit cells were extracted to detect the expression of HIF-1α, VEGF, EMT-related molecules, LCSCs-related molecules, and to observe the density of the subcutaneous vascular network of hollow fiber conduits. The liver metastasis model of splenic injection was constructed to observe the effect of HQZX decoction on tumor metastasis. The hollow fiber hepatocellular carcinoma model was evaluated for the efficacy of HQZX decoction, and it was found to have the highest growth inhibition of LM3-luc cells. In vitro, the CCK8 assay revealed that HQZX decoction could inhibit tumor migration and invasion and promote apoptosis. In addition, the mechanism study of extracting cells from hollow fiber tubes found that HQZX decoction could inhibit metastasis-associated HIF-1α, VEGF, EMT-related molecules, and LCSCs-related molecules expression. capillary network around subcutaneous fiber tubes was reduced in the HQZX decoction gavage group of mice. It inhibited tumor metastasis in nude mice. HQZX decoction inhibited the growth of a variety of hepatocellular carcinoma cells. HQZX decoction suppressed the expression of metastasis-associated VEGF, EMT-related molecules, and LCSCs-related molecules and inhibited tumor angiogenesis and growth and metastasis, which may be related to the inhibition of the HIF-1α signaling pathway. It reveals that HQZX decoction may be a promising herbal compound for anti-HCC therapy, and also reveals the accurate feasibility of the hollow fiber hepatocellular carcinoma model for in vivo pharmacodynamic evaluation and mechanism study.

ERVK13-1/miR-873-5p/GNMT Axis Promotes Metastatic Potential in Human Bladder Cancer though Sarcosine Production.

N-methyl-glycine (sarcosine) is known to promote metastatic potential in some cancers; however, its effects on bladder cancer are unclear. T24 cells derived from invasive cancer highly expressed GNMT, and S-adenosyl methionine (SAM) treatment increased sarcosine production, promoting proliferation, invasion, anti-apoptotic survival, sphere formation, and drug resistance. In contrast, RT4 cells derived from non-invasive cancers expressed low GNMT, and SAM treatment did not produce sarcosine and did not promote malignant phenotypes. In T24 cells, the expression of miR-873-5p, which suppresses GNMT expression, was suppressed, and the expression of ERVK13-1, which sponges miR-873-5p, was increased. The growth of subcutaneous tumors, lung metastasis, and intratumoral GNMT expression in SAM-treated nude mice was suppressed in T24 cells with ERVK13-1 knockdown but promoted in RT4 cells treated with miR-873-5p inhibitor. An increase in mouse urinary sarcosine levels was observed to correlate with tumor weight. Immunostaining of 86 human bladder cancer cases showed that GNMT expression was higher in cases with muscle invasion and metastasis. Additionally, urinary sarcosine concentrations increased in cases of muscle invasion. Notably, urinary sarcosine concentration may serve as a marker for muscle invasion in bladder cancer; however, further investigation is necessitated.

Asiatic acid affects the growth of human osteosarcoma cells by regulating PI3K/AKT and NF-κB dual signal pathways

Osteosarcoma(OS) is a common primary malignant bone tumor, which mostly occurs in children and adolescents. Currently, chemotherapy drugs for the clinical treatment of OS have high side effects and patients are prone to chemotherapy resistance, which reduces the therapeutic effect. Therefore, the development of new therapeutic drugs is very important to reduce the toxicity and adverse reactions of drugs and improve the survival rate of patients. At present, the antitumor activity of traditional Chinese medicine monomers has received extensive attention because of its safety and efficacy. Asiatic acid (AA) is a naturally pentacyclic triterpenoids extracted from Centella asiatica. The aim of this study was to evaluate the effect and mechanism of AA on OS cells in vitro and in vivo. In vitro results showed that AA inhibited the proliferation, migration and invasion of OS cells and was able to induce apoptosis and cycle arrest. In vivo results showed that AA inhibited the growth of OS and the size of lung metastasis in nude mice. Network pharmacology, molecular docking and in vitro experiments prove that AA may play a role in the treatment of OS by inhibiting PI3K/AKT and NF-κB signaling pathways. Our study shows that AA can act on multiple targets of OS and regulate multiple pathways to intervene in the occurrence and development of OS, which may provide reference for the clinical application and development of AA.

Upregulation of miR-194-5p or silencing of PRC1 enhances radiotherapy sensitivity in esophageal squamous carcinoma cells

BackgroundTo investigate the possible molecular mechanism of miR-194-5p/PRC1/Wnt/β-catenin signaling axis that regulates the invasive metastatic ability and radiotherapy sensitivity of esophageal squamous cell carcinoma (ESCC) cells. MethodsESCC-related differentially expressed miRNAs were identified by microarray analysis, followed by the identification of a putative target. The targeting relationship between miR-194-5p and PRC1 was assayed. A series of mimic and shRNA were transfected into ESCC cells to find out the mechanism of miR-194-5p in ESCC by regulating PRC1 through Wnt/β-catenin signaling pathway and their effect on cell proliferation, migration, invasion, and radiosensitivity as well as xenograft tumor growth and metastasis in nude mice. ResultsWe demonstrated low miR-194-5p expression and high PRC1 expression in ESCC tissues and cells. PRC1 was confirmed as a putative target for miR-194-5p. High miR-194-5p or silenced PRC1 enhanced ESCC cell radiosensitivity but reduced proliferation, invasion, and migration via PRC1 through modulation of the Wnt/β-catenin signaling pathway. Animal experiments also validated that overexpression of miR-194-5p suppressed tumorigenesis and in vivo metastasis in nude mice.Conclusion: miR-194-5p can inhibit the Wnt/β-catenin signaling pathway through down-regulation of the PRC1 gene, thereby enhancing the sensitivity of ESCC cells to radiotherapy and attenuating the invasion and metastasis ability of ESCC cells.

Synaptotagmin 1 Suppresses Colorectal Cancer Metastasis by Inhibiting ERK/MAPK Signaling-Mediated Tumor Cell Pseudopodial Formation and Migration.

Although synaptotagmin 1 (SYT1) has been identified participating in a variety of cancers, its role in colorectal cancer (CRC) remains an enigma. This study aimed to demonstrate the effect of SYT1 on CRC metastasis and the underlying mechanism. We first found that SYT1 expressions in CRC tissues were lower than in normal colorectal tissues from the CRC database and collected CRC patients. In addition to this, SYT1 expression was also lower in CRC cell lines than in the normal colorectal cell line. SYT1 expression was downregulated by TGF-β (an EMT mediator) in CRC cell lines. In vitro, SYT1 overexpression repressed pseudopodial formation and reduced cell migration and invasion of CRC cells. SYT1 overexpression also suppressed CRC metastasis in tumor-bearing nude mice in vivo. Moreover, SYT1 overexpression promoted the dephosphorylation of ERK1/2 and downregulated the expressions of Slug and Vimentin, two proteins tightly associated with EMT in tumor metastasis. In conclusion, SYT1 expression is downregulated in CRC. Overexpression of SYT1 suppresses CRC cell migration, invasion, and metastasis by inhibiting ERK/MAPK signaling-mediated CRC cell pseudopodial formation. The study suggests that SYT1 is a suppressor of CRC and may have the potential to be a therapeutic target for CRC.

The regulatory role of cancer stem cell marker gene CXCR4 in the growth and metastasis of gastric cancer

Single-cell RNA sequencing (scRNA-seq) and bulk RNA sequencing (bulk RNA-seq) are increasingly used for screening genes involved in carcinogenesis due to their capacity for dissecting cellular heterogeneity. This study aims to reveal the molecular mechanism of the cancer stem cells (CSCs) marker gene CXCR4 in gastric cancer (GC) growth and metastasis through scRNA-seq combined with bulk RNA-seq. GC-related scRNA-seq data were downloaded from the GEO database, followed by UMAP cluster analysis. Non-malignant cells were excluded by the K-means algorithm. Bulk RNA-seq data and clinical sample information were downloaded from the UCSC Xena database. GO and KEGG pathway analyses validated the correlation between genes and pathways. In vitro and in vivo functional assays were used to examine the effect of perturbed CXCR4 on malignant phenotypes, tumorigenesis, and liver metastasis. A large number of highly variable genes were identified in GC tissue samples. The top 20 principal components were selected, and the cells were clustered into 6 cell types. The C4 cell cluster from malignant epithelial cells might be CSCs. CXCR4 was singled out as a marker gene of CSCs. GC patients with high CXCR4 expression had poor survival. Knockdown of CXCR4 inhibited the malignant phenotypes of CSCs in vitro and curtailed tumorigenesis and liver metastasis in nude mice. CSC marker gene CXCR4 may be a key gene facilitating malignant phenotypes of CSCs, which thus promotes tumor growth and liver metastasis of GC.

Exosomal PGAM1 promotes prostate cancer angiogenesis and metastasis by interacting with ACTG1

Tumor-derived exosomes and their contents promote cancer metastasis. Phosphoglycerate mutase 1 (PGAM1) is involved in various cancer-related processes. Nevertheless, the underlying mechanism of exosomal PGAM1 in prostate cancer (PCa) metastasis remains unclear. In this study, we performed in vitro and in vivo to determine the functions of exosomal PGAM1 in the angiogenesis of patients with metastatic PCa. We performed Glutathione-S-transferase pulldown, co-immunoprecipitation, western blotting and gelatin degradation assays to determine the pathway mediating the effect of exosomal PGAM1 in PCa. Our results revealed a significant increase in exosomal PGAM1 levels in the plasma of patients with metastatic PCa compared to patients with non-metastatic PCa. Furthermore, PGAM1 was a key factor initiating PCa cell metastasis by promoting invadopodia formation and could be conveyed by exosomes from PCa cells to human umbilical vein endothelial cells (HUVECs). In addition, exosomal PGAM1 could bind to γ-actin (ACTG1), which promotes podosome formation and neovascular sprouting in HUVECs. In vivo results revealed exosomal PGAM1 enhanced lung metastasis in nude mice injected with PCa cells via the tail vein. In summary, exosomal PGAM1 promotes angiogenesis and could be used as a liquid biopsy marker for PCa metastasis.

TSPAN8 regulates EGFR/AKT pathway to enhance metastasis in gastric cancer.

Tetraspanin 8 (TSPAN8), a transmembrane glycoprotein, is implicated in various pathological conditions including human malignancies. However, the roles and underlying mechanisms of TSPAN8 in promoting gastric cancer(GC)progression are yet to be fully understood. Our study found that TSPAN8 expression was significantly elevated in GC tissues. We also observed a positive correlation between high TSPAN8 expression and various clinicopathological characteristics of GC, including tumor differentiation, invasion depth, lymph node metastasis, and clinical stage. Moreover, the elevated TSPAN8 expression was indicative of poor prognosis. Functionally, we observed that knockdown of TSPAN8 significantly attenuated while overexpression of TSPAN8 promoted GC cell migration and invasion. In vivo experiments, knockdown of TSPAN8 suppressed lung metastasis in nude mice. We further explored the underlying mechanisms of TSPAN8 and found that it regulated EGFR expression in GC cells by accelerating phosphorylation of EGFR and AKT. Our study reveals that TSPAN8 plays a significant role in promoting tumor metastasis by activating the EGFR/AKT pathway, indicating that it may serve as a promising therapeutic target of gastric cancer.

Aquaporin 1 is a prognostic marker and inhibits tumour progression through downregulation of Snail expression in intrahepatic cholangiocarcinoma.

Recently, some studies have suggested a link between AQP1 and cancer progression. The aim of the present study was to investigate the influence of AQP1 on the clinicopathology and prognosis of intrahepatic cholangiocarcinoma (ICC) patients. We retrospectively detected the expression of AQP1 protein in 307 patients with ICC who underwent partial hepatectomy. Western blot analysis was used to detect AQP1 protein levels in stable AQP1 overexpression and knockdown cell lines. The influence of AQP1 on the invasion and metastasis ability of ICC cells was assessed by wound-healing and Transwell assays in vitro as well as by a splenic liver metastasis model in vivo. Positive membranous AQP1 expression was identified in 34.2% (105/307) of the ICC specimens. Survival data revealed that positive AQP1 expression was significantly associated with favourable disease-free survival (DFS) and overall survival (OS) (p=0.0290 and p=0003, respectively). Moreover, high AQP1 expression inhibited the invasion and migration of ICC cells in vitro as well as inhibited liver metastasis in nude mice. Mechanistically, high AQP1 expression in ICC cells increased the levels of E-cadherin but decreased the levels of the Snail transcription factor. AQP1 expression is associated with a favourable prognosis in ICC patients. AQP1 inhibits ICC cell invasion, metastasis, and epithelial-mesenchymal transition (EMT) through downregulation of Snail expression.