Lung Metastasis Assay Research Articles

IQGAP3 signalling mediates intratumoral functional heterogeneity to enhance malignant growth

BackgroundThe elevation of IQGAP3 expression in diverse cancers indicates a key role for IQGAP3 in carcinogenesis. Although IQGAP3 was established as a proliferating stomach stem cell factor and a regulator...

CXCR4 promotes migration, invasion, and epithelial-mesenchymal transition of papillary thyroid carcinoma by activating STAT3 signaling pathway.

Papillary thyroid cancer (PTC) is a serious threat to human health worldwide, while metastasis in the early phase limits therapeutic success and leads to poor survival outcomes. The CXC chemokine receptor type 4 (CXCR4) plays an important role in many cellular movements such as transcriptional modulation, cell skeleton rearrangement, and cell migration, and the change in CXCR4 levels are crucial in various diseases including cancer. In this study, we explored the role of CXCR4 in the migration and invasion of PTC and investigated the potential mechanisms underlying its effects. We analyzed the expression levels of CXCR4 in PTC tissues and cell lines. Would healing migration, Transwell invasion assay in vitro, and tail-vein lung metastasis assay In vivo were performed to evaluated the migration and invasion abilities of PTC cells with stable CXCR4 knockdown or overexpression. Signal transducers and activators of transcription (STAT3) signaling pathway-related protein expressions were examined by Western blotting assays. The results showed that CXCR4 was highly expressed in PTC cell lines and PTC tissues. CXCR4 knockdown in PTC cells dampened the migration, invasion, and epithelial-mesenchymal transition (EMT), whereas CXCR4 overexpression enhanced these properties. In vivo, we also found that CXCR4 promoted the metastasis of PTC. Mechanistic studies showed that CXCR4 played these vital roles through the STAT3 signaling pathway. Furthermore, PTC patients with high CXCR4 or p-STAT3 expression correlated with aggressive clinical characteristics such as extrathyroidal extension (ETE), and lymph node metastasis (LNM). We provided evidence that CXCR4 might activate the STAT3 signaling pathway and further promote PTC development. Thus, CXCR4 might be a novel therapeutic target for PTC.

MT1G induces lipid droplet accumulation through modulation of H3K14 trimethylation accelerating clear cell renal cell carcinoma progression

BackgroundLipid droplet formation is a prominent histological feature in clear cell renal cell carcinoma (ccRCC), but the significance and mechanisms underlying lipid droplet accumulation remain unclear.MethodsExpression and clinical significance of MT1G in ccRCC were analyzed by using TCGA data, GEO data and scRNASeq data. MT1G overexpression or knockdown ccRCC cell lines were constructed and in situ ccRCC model, lung metastasis assay, metabolomics and lipid droplets staining were performed to explore the role of MT1G on lipid droplet accumulation in ccRCC.ResultsInitially, we observed low MT1G expression in ccRCC tissues, whereas high MT1G expression correlated with advanced disease stage and poorer prognosis. Elevated MT1G expression promoted ccRCC growth and metastasis both in vitro and in vivo. Mechanistically, MT1G significantly suppressed acylcarnitine levels and downstream tricarboxylic acid (TCA) cycle activity, resulting in increased fatty acid and lipid accumulation without affecting cholesterol metabolism. Notably, MT1G inhibited H3K14 trimethylation (H3K14me3) modification. Under these conditions, MT1G-mediated H3K14me3 was recruited to the CPT1B promoter through direct interaction with specific promoter regions, leading to reduced CPT1B transcription and translation.ConclusionsOur study unveils a novel mechanism of lipid droplet accumulation in ccRCC, where MT1G inhibits CPT1B expression through modulation of H3K14 trimethylation, consequently enhancing lipid droplet accumulation and promoting ccRCC progression.Graphical abstract figure Schematic diagram illustrating MT1G/H3K14me3/CPT1B-mediated lipid droplet accumulation promoted ccRCC progression via FAO inhibition.

DMT1-dependent endosome-mitochondria interactions regulate mitochondrial iron translocation and metastatic outgrowth.

Transient early endosome (EE)-mitochondria interactions can mediate mitochondrial iron translocation, but the associated mechanisms are still elusive. We showed that Divalent Metal Transporter 1 (DMT1) sustains mitochondrial iron translocation via EE-mitochondria interactions in triple-negative MDA-MB-231, but not in luminal A T47D breast cancer cells. DMT1 silencing increases labile iron pool (LIP) levels and activates PINK1/Parkin-dependent mitophagy in MDA-MB-231 cells. Mitochondrial bioenergetics and the iron-associated protein profile were altered by DMT1 silencing and rescued by DMT1 re-expression. Transcriptomic profiles upon DMT1 silencing are strikingly different between 2D and 3D culture conditions, suggesting that the environment context is crucial for the DMT1 knockout phenotype observed in MDA-MB-231 cells. Lastly, in vivo lung metastasis assay revealed that DMT1 silencing promoted the outgrowth of lung metastatic nodules in both human and murine models of triple-negative breast cancer cells. These findings reveal a DMT1-dependent pathway connecting EE-mitochondria interactions to mitochondrial iron translocation and metastatic fitness of breast cancer cells.

Role of Cyclin D1b in Inducing Macrophages Toward a Tumor-associated Macrophage-like Phenotype in Murine Breast Cancer.

Tumor-associated macrophages (TAMs) of the M2 phenotype are frequently associated with cancer progression. Invasive cancer cells undergoing epithelial-mesenchymal transition (EMT) have a selective advantage as TAM activators. Cyclin D1b is a highly oncogenic splice variant of cyclin D1. We previously reported that cyclin D1b enhances the invasiveness of breast cancer cells by inducing EMT. However, the role of cyclin D1b in inducing macrophage differentiation toward tumor-associated macrophage-like cells remains unknown. This study aimed to explore the relationship between breast cancer cells overexpressing cyclin D1b and TAMs. Mouse breast cancer 4T1 cells were transfected with cyclin D1b variant and co-cultured with macrophage cells in a Transwell coculture system. The expression of characteristic cytokines in differentiated macrophages was detected using qRT-PCR, ELISA and zymography assay. Tumor-associated macrophage distribution in a transplanted tumor was detected by immunofluorescence staining. The proliferation and migration ability of breast cancer cells was detected using the cell counting kit-8 (CCK-8) assay, wound healing assay, Transwell invasion assay, and lung metastasis assay. Expression levels of mRNAs were detected by qRT-PCR. Protein expression levels were detected by Western blotting. The integrated analyses of The Cancer Genome Atlas (TCGA) datasets and bioinformatics methods were adopted to discover gene expression, gene coexpression, and overall survival in patients with breast cancer. After co-culture with breast cancer cells overexpressing cyclin D1b, RAW264.7 macrophages were differentiated into an M2 phenotype. Moreover, differentiated M2-like macrophages promoted the proliferation and migration of breast cancer cells in turn. Notably, these macrophages facilitated the migration of breast cancer cells in vivo. Further investigations indicated that differentiated M2-like macrophages induced EMT of breast cancer cells accompanied with upregulation of TGF-β1 and integrin β3 expression. Breast cancer cells transfected with cyclin D1b can induce the differentiation of macrophages into a tumor-associated macrophage-like phenotype, which promotes tumor metastasis in vitro and in vivo.

Dysregulation of PLOD2 Promotes Tumor Metastasis and Invasion in Hepatocellular Carcinoma.

Metastasis is a major factor associated with high recurrence and mortality in hepatocellular carcinoma (HCC) patients while the underlying mechanism of metastasis remains elusive. In our study, procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) was shown to be involved in the process of metastasis in HCC. The Cancer Genome Atlas (TCGA) database and HCC tissue microarrays were used to evaluate the expression of genes. In vitro migration, invasion, in vivo subcutaneous tumor model and in vivo lung metastasis assays were used to determine the role of PLOD2 in tumor growth and metastasis in HCC. RNA sequencing and gene set enrichment analysis were performed to uncover the downstream factor of PLOD2 in HCC cells. A luciferase reporter assay was performed to evaluate the interaction between PLOD2 and interferon regulatory factor 5 (IRF5). The expression of PLOD2 in HCC tissues was higher than that in adjacent tissues, and increased PLOD2 expression was often found in advanced tumors and was correlated with poor prognosis in HCC patients. In vitro experiments, knockdown of PLOD2 reduced the migration and invasion of human HCC cells. Loss of PLOD2 suppressed human HCC growth and metastasis in a subcutaneous tumor model and a lung metastasis model. Baculoviral IAP repeat containing 3 (BIRC3) was proven to be the downstream factor of PLOD2 in human HCC cells. In addition, PLOD2 was transcriptionally regulated by IRF5 in HCC cells. High expression of PLOD2 was regulated by IRF5, which was correlated with the poor survival of HCC patients. PLOD2 enhanced HCC metastasis via BIRC3, suggesting that PLOD2 might be a valuable prognostic biomarker for HCC treatment.

Metastasis suppressor NME1 in exosomes or liposomes conveys motility and migration inhibition in breast cancer model systems.

Tumor-derived exosomes have documented roles in accelerating the initiation and outgrowth of metastases, as well as in therapy resistance. Little information supports the converse, that exosomes or similar vesicles can suppress metastasis. We investigated the NME1 (Nm23-H1) metastasis suppressor as a candidate for metastasis suppression by extracellular vesicles. Exosomes derived from two cancer cell lines (MDA-MB-231T and MDA-MB-435), when transfected with the NME1 (Nm23-H1) metastasis suppressor, secreted exosomes with NME1 as the predominant constituent. These exosomes entered recipient tumor cells, altered their endocytic patterns in agreement with NME1 function, and suppressed in vitro tumor cell motility and migration compared to exosomes from control transfectants. Proteomic analysis of exosomes revealed multiple differentially expressed proteins that could exert biological functions. Therefore, we also prepared and investigated liposomes, empty or containing partially purified rNME1. rNME1 containing liposomes recapitulated the effects of exosomes from NME1 transfectants in vitro. In an experimental lung metastasis assay the median lung metastases per histologic section was 158 using control liposomes and 15 in the rNME1 liposome group, 90.5% lower than the control liposome group (P = 0.016). The data expand the exosome/liposome field to include metastasis suppressive functions and describe a new translational approach to prevent metastasis.

The CBP/β-Catenin Antagonist, ICG-001, Inhibits Tumor Metastasis via Blocking of the miR-134/ITGB1 Axis-Mediated Cell Adhesion in Nasopharyngeal Carcinoma.

Simple SummaryMetastatic nasopharyngeal carcinoma (NPC) is incurable and remains the main cause of NPC death. Our previous studies found that the CBP/β-catenin Wnt antagonist, IGC-001, could inhibit the primary tumor formation of NPC tumor cells. Here, we further explored the anti-metastatic activity of ICG-001. We started by screening a panel of microRNAs that are related to epithelial–mesenchymal transition and cancer stem cell phenotypes; both properties can contribute to tumor metastasis. MicroRNA-134 was found to be consistently upregulated by ICG-001. The role of miR-134 in NPC is largely unknown but some studies found an association between low expression of miR-134 and poor prognosis. We examined the role of miR-134 in NPC with both in vitro and in vivo models and found that miR-134 could inhibit cancer cell adhesion, migration, and invasion. Our study provided a functional explanation for the poor prognosis observed in NPC patients with low or loss of miR-134 expression in their tumors and showed that modulation of the Wnt signaling by ICG-001 could effectively inhibit NPC metastasis via the miR-134/ITGB1 axis.Nasopharyngeal carcinoma (NPC) is an Epstein–Barr virus (EBV)-associated malignancy ranking as the 23rd most common cancer globally, while its incidence rate ranked the 9th in southeast Asia. Tumor metastasis is the dominant cause for treatment failure in NPC and metastatic NPC is yet incurable. The Wnt/β-catenin signaling pathway plays an important role in many processes such as cell proliferation, differentiation, epithelial–mesenchymal transition (EMT), and self-renewal of stem cells and cancer stem cells (CSCs). Both the EMT process and CSCs are believed to play a critical role in cancer metastasis. We here investigated whether the specific CBP/β-catenin Wnt antagonist, IGC-001, affects the metastasis of NPC cells. We found that ICG-001 treatment could reduce the adhesion capability of NPC cells to extracellular matrix and to capillary endothelial cells and reduce the tumor cell migration and invasion, events which are closely associated with distant metastasis. Through a screening of EMT and CSC-related microRNAs, it was found that miR-134 was consistently upregulated by ICG-001 treatment in NPC cells. Very few reports have mentioned the functional role of miR-134 in NPC, except that the expression was found to be downregulated in NPC. Transient transfection of miR-134 into NPC cells reduced their cell adhesion, migration, and invasion capability, but did not affect the growth of CSC-enriched tumor spheres. Subsequently, we found that the ICG-001-induced miR-134 expression resulting in downregulation of integrin β1 (ITGB1). Such downregulation reduced cell adhesion and migration capability, as demonstrated by siRNA-mediated knockdown of ITGB1. Direct targeting of ITGB1 by miR-134 was confirmed by the 3′-UTR luciferase assay. Lastly, using an in vivo lung metastasis assay, we showed that ICG-001 transient overexpression of miR-134 or stable overexpression of miR-134 could significantly reduce the lung metastasis of NPC cells. Taken together, we present here evidence that modulation of Wnt/β-catenin signaling pathway could inhibit the metastasis of NPC through the miR-134/ITGB1 axis.

Abstract 1799: Inhibition of triple negative breast cancer metastasis via Enolase-1 modulation

Abstract Triple-negative breast cancer (TNBC) is one of the aggressive forms of breast cancer and frequently relapses and metastases. Currently, very few options are available for TNBC treatment. Cancer cells exploit glycolytic machinery for the Warburg effect and aerobic glycolysis. Enolase 1 (ENO1) is the glycolytic enzyme expressed in the majority of tissues and many cancer cells have its higher expression. Apart from the glycolytic role in the cytosol, ENO1 also plays different roles in cancer cells including function as a surface receptor. We have developed a chemical small molecule (CET12) that strongly binds to ENO1 and restrain its activity and subcellular localization. CET12 treatment arrests the TNBC cells in the mitotic phase and leads the apoptotic cell death via AMPK activation. Global proteome profiling suggested that CET12 pushes the cells toward oxidative phosphorylation. It also inhibits cell migration and invasion in vitro. In vivo studies using 4T1 and EMT6 syngeneic mouse models are also in-line with in vitro results and revealed that SU0212 treatment inhibits tumor progression and metastasis. These results were further supported by tail vain lung metastasis assay and intracardiac injection mouse model. This study provides compelling preclinical data for further development of CET12 for the treatment of TNBC. Citation Format: Dhanir Tailor, Arpit Dheeraj, Fernando Jose Garcia-Marques, Mallesh Pandrala, Abel Bermudez, Sharon Pitteri, Sanjay V. Malhotra. Inhibition of triple negative breast cancer metastasis via Enolase-1 modulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1799.

Silencing of LINC01963 enhances the chemosensitivity of prostate cancer cells to docetaxel by targeting the miR-216b-5p/TrkB axis

AbstractDocetaxel (DTX) treatment effectively prolongs the overall survival of patients with prostate cancer. However, most patients eventually develop resistance to chemotherapy and experience tumor progression or even death. Long noncoding RNAs (lncRNAs) affect docetaxel chemosensitivity. However, the biological role and regulatory mechanisms of lncRNAs in docetaxel-resistant prostate cancer remain unclear. Differences in lncRNAs were evaluated by lncRNA sequencing and evaluated using quantitative real-time polymerase chain reaction, and TrkB expression was measured through western blot analysis. Proliferation was measured using the MTS, while apoptosis and cell cycle were measured using flow cytometry. In addition, migration and invasion were measured using transwell assays. Forty-eight female BALB/c nude mice were used for subcutaneous tumorigenicity and lung metastasis assays. We found that LINC01963 was overexpressed in the PC3-DR cells. LINC01963 silencing enhanced the chemosensitivity of PC3-DR to docetaxel and inhibited tumorigenicity and lung metastasis, while LINC01963 overexpression enhanced the chemoresistance of PC3 cells to docetaxel. It was found that LINC01963 bind to miR-216b-5p. The miR-216b-5p inhibitor reversed the suppressive effect of sh-LINC01963 on PC3-DR cell proliferation, migration, and invasion. Furthermore, miR-216b-5p can bind to the 3′-UTR of NTRK2 and inhibit TrkB protein levels. TrkB enhances docetaxel resistance in prostate cancer and reverses the effects of LINC01963 silencing and miR-216b-5p overexpression. In conclusion, silencing LINC01963 inhibited TrkB protein level to enhance the chemosensitivity of PC3-DR to docetaxel by means of competitively binding to miR-216b-5p. This study illustrates that LINC01963 is a novel therapeutic target for treating prostate cancer patients with DTX resistance.

BMI1 promotes osteosarcoma proliferation and metastasis by repressing the transcription of SIK1

BackgroundOsteosarcoma (OS) is the most common malignant tumor of bone, and the clinical efficacy of current treatments and associated survival rates need to be further improved by employing novel therapeutic strategies. Although various studies have shown that BMI1 protein is universally upregulated in OS cells and tissues, its specific role and underlying mechanism have not yet been fully explored.MethodsExpression of BMI1 protein in OS cells was detected by western blot. The effect of BMI1 on proliferation and migration of OS cells (143B and U-2OS cell lines) was investigated in vitro using CCK-8, colony formation and transwell assays, and in vivo using subcutaneous tumorigenesis and lung metastasis assays in xenograft nude mice. Expression of epithelial–mesenchymal transition (EMT)-associated proteins was detected by immunofluorescence imaging. Bioinformatic analysis was performed using ENCODE databases to predict downstream targets of BMI1. SIK1 mRNA expression in osteosarcoma cells was detected by quantitative real-time reverse transcription PCR (qPCR). Chromatin immunoprecipitation-qPCR (ChIP-qPCR) was used to investigate expression of BMI1-associated, RING1B-associated, H2AK119ub-associated and H3K4me3-associated DNA at the putative binding region of BMI1 on the SIK1 promoter in OS cells.ResultsUsing both in vitro and in vivo experimental approaches, we found that BMI1 promotes OS cell proliferation and metastasis. The tumor suppressor SIK1 was identified as the direct target gene of BMI1 in OS cells. In vitro experiments demonstrated that SIK1 could inhibit proliferation and migration of OS cells. Inhibition of SIK1 largely rescued the altered phenotypes of BMI1-deficient OS cells. Mechanistically, we demonstrated that BMI1 directly binds to the promoter region of SIK1 in a complex with RING1B to promote monoubiquitination of histone H2A at lysine 119 (H2AK119ub) and inhibit H3K4 trimethylation (H3K4me3), resulting in inhibition of SIK1 transcription. We therefore suggest that BMI1 promotes OS cell proliferation and metastasis by inhibiting SIK1.ConclusionsOur results reveal a novel molecular mechanism of OS development promoted by BMI1 and provides a new potential target for OS treatment.

CircSYPL1 Promotes the Proliferation and Metastasis of Hepatocellular Carcinoma via the Upregulation of EZH2 Expression by Competing with hsa-miR-506-3p.

Objective Circular RNAs (circRNAs) and microRNAs are crucial for progressing of hepatocellular carcinoma (HCC). Nonetheless, the function or mechanisms of a newly discovered circRNA, circSYPL1, as well as miR-506-3p, in the progression of HCC are mostly unexplained. The purpose of this research was to determine the mechanisms by which circSYPL1 and miR-506-3p regulate the malignant features of HCC. Methods The expression level of circSYPL1 was indeed detected using real-time PCR in HCC cell lines, primary as well as metastatic cancers. To assess the functionality of circSYPL1 upregulation and knockdown, we used proliferation and apoptosis, in addition to migration assays, as well as tumor xenograft and lung metastasis assays. The mechanisms of competing endogenous RNAs with circSYPL1/miR-506-3p/EZH2 were investigated using luciferase as well as RNA pull-down experiments. Lastly, cell proliferation and migration, in addition to tumor xenograft tests, were used to validate the biological significance of the circSYPL1/miR-506-3p/EZH2 signaling axis through overexpression or otherwise silencing. Results circSYPL1 expression was significantly upregulated in HCC cell lines, in addition to primary and metastatic tumors of patients with HCC. Additionally, it may promote HCC initiation, development as well as progression. By knocking down circSYPL1 siRNA, we were able to drastically decrease the aggressiveness of HCC cells. circSYPL1 sponged miR-506-3p to boost EZH2 expression levels, as indicated by luciferase and RNA pull-down assays. Furthermore, circSYPL1 overexpression could upregulate EZH2 expression, while miR-506-3p mimics or EZH2 shRNAs could reverse the circSYPL1-induced malignancy of HCC cells. Conclusion On a mechanistic level, circSYPL1 can interact with miR-506-3p in a competitive manner to upregulate EZH2, hence increasing the aggressiveness of tumors.

CircRNA_0040705 promotes the progression of hepatocellular carcinoma.

Circular RNAs (circRNAs) are involved in cancer progression. Nonetheless, the role and mechanism of circ_0040705 in hepatocellular carcinoma (HCC) are unclear. The aberrantly expressed circRNAs and microRNAs (miRNAs) in HCC tissues were screened by bioinformatics. Circ_0040705, miR-557, SRY-box transcription factor 2 (SOX2), E-cadherin, and N-cadherin expressions were determined using quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot. Cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and Transwell experiments were utilized to examine the changes in HCC cell growth, migration, and invasion after circ_0040475 was overexpressed or knocked down. Lung metastasis assay was used to validate the effects of circRNA_0040705 on the lung metastasis of HCC cells in vivo. Binding sequences between circ_0040705 and miR-557 and between miR-557 and SOX2 were verified using dual-luciferase reporter gene experiments. The expression levels of circ_0040705 and SOX2 mRNA were markedly increased in HCC tissues, but miR-557 expression was down-regulated. Circ_0040705 overexpression enhanced the growth, migration, invasion, and the expressions of E-cadherin and N-cadherin of HCC cells and promoted lung metastasis in vivo, whereas circ_0040705 knockdown exerted the opposite effects in HCC cells. Circ_0040705 worked as a sponge for miR-557 to down-modulate miR-557 expression, and miR-557 could specifically down-modulate SOX2 expression. Circ_0040705 facilitates HCC cell growth, migration, and invasion by down-modulating miR-557 expression and up-modulating SOX2 expression.

Inhibitory effects of orally administered pectic polysaccharides extracted from the citrus Hallabong peel on lung metastasis

In this study, we investigated the anti-metastatic effect of the pectic polysaccharide HBE-0, extracted from peels of Hallabong, Korea citrus by pectinase digestion and ethanol precipitation. HBE-0 comprises 64.4% neutral sugars and 31.7% uronic acid including 14 types of monosaccharides. IL-6 and IL-12 were secreted in a dose-dependent manner by peritoneal macrophages stimulated with HBE-0. Intravenous administration of HBE-0 significantly augmented the cytolytic activity of NK cells. In lung metastasis assays using Colon26-M3.1 carcinoma cells, prophylactically intravenous administration of HBE-0 at a dose of 50 mg/kg showed up to 90% inhibitory effect on lung metastasis. Furthermore, NK cells depletion by anti-asialo-GM1 partially reduced the inhibitory effect of HBE-0 on lung metastasis. Further, oral administration of HBE-0 induced NK cell cytotoxicity and dose-dependently inhibited lung metastasis. These results suggest that HBE-0 isolated from Hallabong peels possesses anti-metastatic activity and supports its potential as a health-functional or pharmacological agent in commercial applications by increasing the high added-value of discarded agricultural byproducts.

Local anesthetic bupivacaine inhibits proliferation and metastasis of hepatocellular carcinoma cells via suppressing PI3K/Akt and MAPK signaling.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. Retrospective studies suggest that using local/regional anesthetic (LA/RA) is associated with better outcomes in primary HCC patients. In this study, we evaluated the effects of LA/RA bupivacaine in HCC cells and the underlying molecular mechanisms. The biological functions of bupivacaine in HCC cells were evaluated by transcriptome RNA sequencing, cell viability assay, bromodeoxyuridine incorporation assay, colony formation assay, flow cytometry, western blot, wound healing assay, transwell cell migration assay, tumor xenograft formation, and lung metastasis assay. Bupivacaine suppressed proliferation and induced apoptosis of HepG2 and SNU-449 cells in a time- and dose-dependent manner. Bupivacaine treatment also decreased colony formation, migration, and invasion of HepG2 and SNU-449 cells. In mouse models, bupivacaine repressed tumor xenograft growth and lung metastasis of HepG2 cells. Transcriptome sequencing of HepG2 cells suggested that PI3K/Akt and MAPK signaling pathways were suppressed by bupivacaine treatment. In western blot analysis, bupivacaine reduced the expression of total and phosphorylated Akt, mTOR, and MAPK. Furthermore, reactivated PI3K/Akt and MAPK signaling by EGF or NRG1 partially reversed the effects of bupivacaine on cell growth, colony formation, and invasion of HCC cells. Local anesthetic bupivacaine suppressed proliferation, migration and invasion, and induced apoptosis of HCC cells. Our results provided novel insights into the local anesthetic bupivacaine in the therapy of HCC patients.

A novel CXCR4 antagonist counteracts paradoxical generation of cisplatin-induced pro-metastatic niches in lung cancer

Platinum-based chemotherapy remains widely used in advanced non-small cell lung cancer (NSCLC) despite experimental evidence of its potential to induce long-term detrimental effects, including the promotion of pro-metastatic microenvironments. In this study, we investigated the interconnected pathways underlying the promotion of cisplatin-induced metastases.In tumor-free mice, cisplatin treatment resulted in an expansion in the bone marrow of CCR2+CXCR4+Ly6Chigh inflammatory monocytes (IMs) and an increase in lung levels of stromal SDF-1, the CXCR4 ligand. In experimental lung metastasis assays, cisplatin-induced IMs promoted the extravasation of tumor cells and the expansion of CD133+CXCR4+ metastasis-initiating cells (MICs). Peptide R, a novel CXCR4 inhibitor designed as an SDF-1 mimetic peptide, prevented cisplatin-induced IM expansion, the recruitment of IMs into the lungs, and the promotion of metastasis. At the primary tumor site, cisplatin treatment reduced tumor size while simultaneously inducing tumor release of SDF-1, MIC expansion, and recruitment of pro-invasive CXCR4+ macrophages. Co-recruitment of MICs and CCR2+CXCR4+ IMs to distant SDF-1-enriched sites also promoted spontaneous metastases that were prevented by CXCR4 blockade. In clinical specimens from NSCLC patients SDF-1 levels were found to be higher in platinum-treated samples and related to a worse clinical outcome. Our findings reveal that activation of the CXCR4/SDF-1 axis specifically mediates the pro-metastatic effects of cisplatin and suggest CXCR4 blockade as a possible novel combination strategy to control metastatic disease.

Alkaline phosphatase downregulation promotes lung adenocarcinoma metastasis via the c-Myc/RhoA axis

BackgroundLung adenocarcinoma (LUAD) metastasis significantly reduces patient survival; hence inhibiting the metastatic ability of lung cancer cells will greatly prolong patient survival. Alkaline phosphatase (ALPL), a homodimeric cell surface phosphohydrolase, is reported to play a controversial role in prostate cancer and ovarian cancer cell migration; however, the function of ALPL in LUAD and the related mechanisms remain unclear.MethodsTCGA database was used to analysis the expression of ALPL, and further verification was performed in a cohort of 36 LUAD samples by qPCR and western blot. Soft-agar assay, transwell assay and lung metastasis assay were employed to detect the function of ALPL in LUAD progression. The qPCR, luciferase promoter reporter assay and western blot were used to clarify the molecular mechanisms of ALPL in promoting metastasis in LUAD.ResultsALPL was downregulated in LUAD, and the disease-free survival rate of patients with low ALPL was significantly reduced. Further studies showed that overexpression of ALPL in LUAD cell lines did not significantly affect cell proliferation, but it did significantly attenuate lung metastasis in a mouse model. ALPL downregulation in LUAD led to a decrease in the amount of phosphorylated (p)-ERK. Because p-ERK promotes the classical c-Myc degradation pathway, the decrease in p-ERK led to the accumulation of c-Myc and therefore to an increase in RhoA transcription, which enhanced LUAD cell metastasis.ConclusionALPL specially inhibits the metastasis of LUAD cells by affecting the p-ERK/c-Myc/RhoA axis, providing a theoretical basis for the targeted therapy of clinical LUAD.

Circ-LAMP1 contributes to the growth and metastasis of cholangiocarcinoma via miR-556-5p and miR-567 mediated YY1 activation.

Dysregulation of circular RNAs (circRNAs) executes important regulatory roles in carcinogenesis. Nonetheless, few studies focused on the mechanisms of circRNAs in cholangiocarcinoma (CCA). qRT‐PCR was applied to verify the dysregulated circRNAs in CCA. Fisher's exact test, Kaplan‐Meier analysis and Cox regression model were utilized to investigate the clinical implications of circ‐LAMP1 in the patients with CCA. The viability, apoptosis, migration and invasion of CCA cells were detected after silencing/overexpression of circ‐LAMP1. Xenograft and lung metastasis assays were performed to verify the in vitro results. The regulatory networks of circ‐LAMP1 were unveiled by bioinformatic analysis, RNA immunoprecipitation (RIP), RNA pulldown and luciferase reporter assays. Up‐regulation of circ‐LAMP1 was found in CCA tissue samples and cell lines. Enhanced level of circ‐LAMP1 was linked to clinical severity, high post‐operative recurrence and poor prognosis for the patients with CCA. Gain/loss‐of‐function assays confirmed the oncogenic role of circ‐LAMP1 in mediating cell growth, apoptosis, migration and invasion. Nevertheless, the level of circ‐LAMP1 had no effect on normal biliary epithelium proliferation and apoptosis. Animal study further verified the in vitro data. Mechanistically, circ‐LAMP1 directly sponged miR‐556‐5p and miR‐567, thereby releasing their suppression on YY1 at post‐transcriptional level. Rescue assay indicated that the oncogenic role of circ‐LAMP1 is partially dependent on its modulation of YY1 in CCA. In summary, this study suggested that circ‐LAMP1 might be used as a promising biomarker/therapeutic target for CCA.

Abstract PS19-01: A sense-antisense RNA interaction drives metabolic reprogramming in metastatic breast cancer

Abstract Background: Metabolic reprogramming is a hallmark of breast cancer progression. However, the underlying regulatory pathways that initiate and maintain this process remain largely unexplored. Recently, we have identified a novel antisense RNA that helps protect breast cancer cells against oxidative stress by reprogramming their metabolic redox state. Using cell line and patient-derived xenograft models, as well as direct measurements in clinical samples, we have demonstrated the unique regulatory functions of this antisense RNA in increasing the metastatic capacity of breast cancer cells. Results: Non-coding RNAs have emerged as major drivers of metastatic progression. We have recently demonstrated that specific classes of non-coding RNAs, such as tRNAs (Goodarzi et al, Cell, 2016) and tRNA fragments (Goodarzi et al, Cell, 2015), play major roles in breast cancer metastasis as post-transcriptional regulators of gene expression. However, these types of regulatory RNAs constitute only a fraction of the non-coding RNAs that are aberrantly expressed in highly metastatic cells. For example, antisense RNAs are a large but often ignored class of RNAs with poorly understood cellular functions. We recently developed a new computational algorithm to systematically annotate antisense RNAs and identify those that are associated with metastatic progression based on data from cell line and patient-derived xenograft models, as well as matched primary and metastatic tumors from triple-negative breast cancer patients. We identified a previously unknown antisense RNA, which is transcribed from a locus in the 3’ UTR of the gene NQO1 (and is hence named NQO1-AS). Both NQO1-AS and NQO1 are significantly upregulated in highly metastatic breast cancer cells, and we have shown that the NQO1 sense mRNA is stabilized by the expression of NQO1-AS. Our results indicate that NQO1-AS forms a stable duplex with the 3’ UTR of NQO1 and induces the expression of a longer and more stable isoform of NQO1 mRNA. Metabolomic measurements in NQO1 knockdown and control cells revealed that increased NQO1 activity enables cancer cells to better tolerate the oxidative stress experienced during metastasis. We demonstrated this by performing lung metastasis assays in xenograft models. To confirm the clinical relevance of these findings, we performed comprehensive clinical association studies, and also used quantitative PCR and immunohistochemistry to measure NQO1 levels across all disease stages. We observed a highly significant association between higher NQO1 and NQO1-AS expression and metastatic relapse. Methods: We developed a method named iRAs to annotate and quantify antisense RNAs. We used global run-on assays (GRO-seq) and RNA sequencing in poorly and highly metastatic breast cancer cells to identify NQO1-AS as a novel pro-metastatic antisense RNA. We used both Gapmers and CRISPR-i to knock down NQO1-AS and to measure its impact on NQO1 mRNA stability and expression. We used CRISPRi to silence NQO1 in both MDA-231 and HCC-1806 breast cancer lines, and measured the metabolic consequences of NQO1 knockdown by measuring NADPH flux as well as performing general metabolomic profiling. We also used in vivo lung colonization assays (n=5 mice in each arm) to measure the metastatic capacity of NQO1 knockdown cells. Log-rank test (univariate) and Cox Proportional Hazard Models (multivariate) were used to perform survival analyses in METABRIC and the kmplot aggregate dataset. Mann-Whitney or ANOVA was used to compare expression of NQO1 and NQO1-AS across samples stratified based on sub-type and tumor grade/stage in public datasets as well as our own measurements in clinical samples (n=96; 5 healthy, 23 stage I, 30 stage II, 29 stage III, and 9 stage IV). IHC was performed on tissue microarrays from CHTN (Breast Progression), and blinded scoring was used to assess NQO1 levels. Citation Format: Hani Goodarzi, Bruce Culbertson, Kristle Garcia, Lisa Fish. A sense-antisense RNA interaction drives metabolic reprogramming in metastatic breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS19-01.

SETD1A to induce epithelial-mesenchymal transition to promote invasion and metastasis through epigenetic reprogramming of snail in gastric cancer.

241 Background: Aberrant epigenetic modification induces oncogenes expression and promotes cancer development. The histone lysine methyltransferase SETD1A, which specifically methylates H3K4, is involved in tumor growth and metastasis, and its ectopic expression has been detected in aggressive malignancies. Our previous study had reported that SETD1A promoted gastric cancer (GC) proliferation and tumorigenesis. However, the function and molecular mechanisms of SETD1A in GC metastasis remain to be elucidated. Methods: Transwell migration and invasion assay were performed to determine GC cell migration and invasion. Lung metastasis assay was used to detect GC cell metastasis. Western Blot and Real-time qPCR were performed to measure the protein and mRNA levels, respectively. ChIP assay was performed to investigate the methylation of H3K4. The correlation between SETD1A and EMT associated key genes in GC were performed by bioinformatic analysis. Results: In this study, we found that overexpression of SETD1A promotes GC migration and invasion, whereas knockdown of SETD1A suppressed GC migration, invasion and metastasis. Furthermore, knockdown of SETD1A suppressed GC epithelial-mesenchymal transition (EMT) by increasing the expression of epithelial marker E-cadherin, and decreasing the expression of mesenchymal markers, including N-cadherin, Fibronectin and Vimentin. Mechanistically, knockdown of SETD1A reduced the EMT key transcriptional factors snail. SETD1A was recruited to the promoter of snail, where SETD1A could methylate H3K4. However, knockdown of SETD1A decreased the methylation of H3K4 on snail promoter. Rescue of snail restored SETD1A knockdown-induced GC migration and invasion inhibition. In addition, linear correlation between SETD1A and several key EMT genes, including E-cadherin, Fibronectin and snail, in GC specimens obtained from TCGA dataset. Conclusions: In summary, our data reveals that SETD1A mediated EMT process and induced metastasis through epigenetic reprogramming of snail.