Tumorigenicity Of Cancer Cells Research Articles

Prohibitin 2 confers NADPH oxidase 1 -mediated cytosolic oxidative signaling to promote gastric cancer progression by ERK activation

Oxidative signaling plays a dual role in tumor initiation and progression to malignancy; however, the regulatory mechanisms of Oxidative stress in gastric cancer remain to be explored. In this study, we discovered that Prohibitin 2 (PHB2) specifically regulates cytosolic reactive oxygen species production in gastric cancer and facilitates its malignant progression. Previously, we found that PHB2 is upregulated in gastric cancer, correlating with increased tumorigenicity of gastric cancer cells and poor patient prognosis. Here, we discovered that PHB2 expression correlates with the activation of the ERK/MAPK cascade, positively regulating the top gene NADPH oxidase 1 (NOX1) within this pathway. Further mechanistic investigation reveals that PHB2 enhances NOX1 transcription by interacting with the transcription factor C/EBP-beta and promoting its translocation into the nucleus, resulting in elevated intracellular oxidative signaling driven by NOX1, which subsequently activates ERK. Therefore, we propose that targeting PHB2-C/EBP-beta-NOX1-mediated cytosolic oxidative stress could offer a promising therapeutic avenue for combating gastric cancer malignant progression.

Hsa_circ_0000129 targets miR-383-5p/tropomyosin 3 axis to facilitate ovarian cancer progression.

Ovarian cancer is one of the most prevalent malignancies among women. CircRNAs play key roles in the progression of ovarian cancer. This study aimed to investigate the mechanism of action of hsa_circ_0000129 and its effects on ovarian cancer. Expression of hsa_circ_0000129, tropomyosin 3 (TPM3), and miR-383-5p in ovarian cancer cell lines and tissue specimens was detected using qRT-PCR or western blotting. Cell counting kit-8 (CCK-8), colony formation, and transwell assays were performed to assess viability, proliferation, and migration of ovarian cancer cells. A xenograft model was used to study tumorigenicity of ovarian cancer cells in vivo. Luciferase and RNA immunoprecipitation assays were performed to determine binding between miR-383-5p and hsa_circ_0000129 or TPM3. Upregulation of hsa_circ_0000129 and TPM3 and downregulation of miR-383-5p were observed in ovarian cancer. Low hsa_circ_0000129 and TPM3 expression repressed viability, migration, and proliferation of ovarian cancer cells. Inhibition of miR-383-5p had a contrary effect. Furthermore, knockdown of hsa_circ_0000129 restricted the tumorigenicity of ovarian cancer cells. Mechanistically, hsa_circ_0000129 has a sponging effect on miR-383-5p, which targets TPM3. Hsa_circ_0000129 stimulated development of the malignant ovarian cancer phenotype by sponging miR-383-5p and releasing TPM3.

DNA aptamer-conjugated lipid nanoparticle for targeted PTEN mRNA delivery to prostate cancer cells

The use of messenger RNA (mRNA) as a cancer vaccine and gene therapy requires targeted vehicle delivery to the site of disease. Here, we designed a mRNA-encapsulating lipid nanoparticle (LNP) conjugated with anti-programmed death-ligand 1 (PD-L1) DNA aptamer that delivers mRNA encoding a tumor suppressor gene, namely phosphatase and tensin homolog (PTEN), to castration-resistant prostate cancer (CRPC) cells expressing PD-L1 on the cell surface. The DNA aptamer-conjugated LNP-based mRNA delivery system (Apt-LNP[PTEN mRNA]) mediated efficient mRNA delivery and transfection in CRPC cells than LNPs without targeting ligands. Cancer-targeted PTEN mRNA delivery using Apt-LNPs achieved significantly higher PTEN expression via aptamer-mediated endocytosis in target cancer cells compared with non-targeted LNP delivery, resulting in significant downregulation of AKT phosphorylation. This enhanced PI3K/AKT pathway regulation, and in turn reduced cell migration after two days along with a 70 % decrease in cell viability, leading to effective apoptotic cell death. In a CRPC xenograft model, Apt-LNP[PTEN mRNA] led to an approximate 60 % reduction in tumor growth, which was attributable to the effective PTEN restoration and PI3K/AKT signaling pathway regulation. PTEN expression was significantly enhanced in CRPC tumor tissues, which abolished cancer cell tumorigenicity. These findings demonstrated the potential of Apt-LNPs for targeted mRNA delivery to cancer cells, thus providing a promising tool for targeted mRNA delivery to a range of cancers and tissues using a conventional LNP systems.

Caffeic acid inhibits the tumorigenicity of triple-negative breast cancer cells through the FOXO1/FIS pathway

Triple-negative breast cancer (TNBC) still one of the most challenging sub-type in breast cancer clinical. Caffeic acid (CA) derived from effective components of traditional Chinese herbal medicine has been show potential against TNBCs. Our research has found that CA can inhibit the proliferation of TNBC cells while also suppressing the size of cancer stem cell spheres. Additionally, it reduces reactive oxygen species (ROS) levels and disruption of mitochondrial membrane potential. Simultaneously, CA influences the stemness of TNBC cells by reducing the expression of the stem cell marker protein CD44. Furthermore, we have observed that CA can modulate the FOXO1/FIS signaling pathway, disrupting mitochondrial function, inducing mitochondrial autophagy, and exerting anti-tumor activity. Additionally, changes in the immune microenvironment were detected using a mass cytometer, we found that CA can induce M1 polarization of macrophages, enhancing anti-tumor immune responses to exert anti-tumor activity. In summary, CA can be considered as a lead compound for further research in targeting TNBC.

Attenuated Salmonella typhimurium L forms suppress tumor growth and promote apoptosis in murine ovarian tumors

To study the effects of attenuated Salmonella typhimurium L forms on the in vivo tumorigenicity and apoptosis of murine epithelial ovarian cancer cells, as well as the related mechanisms. Attenuated Salmonella typhimurium VNP20009 was induced into bacterial L forms by using antibiotic ceftriaxone. CCK-8 cell proliferation assay showed that attenuated S. typhimurium L forms can inhibit the proliferation of murine ovarian epithelial cancer ID8 cells. Attenuated ST L forms can induce apoptosis and inhibit invasion ability of epithelial ovarian cancer cells in vitro. TUNEL assay showed that attenuated ST L forms can induce apoptosis of ID8 cells in murine ovarian tumors. Meanwhile, attenuated ST L forms inhibit tumor growth in murine ovarian tumors. The tumorigenicity-related proteins of xenograft tumors detected by immunohistochemistry and fluorescence quantitative RT-PCR assays showed that attenuated ST L forms can reduce the expression of proteins that promote tumor growth and metastasis, such as Lgals9 and MMP9. This study confirmed that attenuated ST L forms can suppress tumor growth and promote apoptosis in murine ovarian tumors. Attenuated ST L forms may serve as a novel biological agent for bacterial-mediated tumor therapy in epithelial ovarian cancer.

Cytosolic N-terminal formyl-methionine deformylation derives cancer stem cell features and tumor progression

Eukaryotic cells can synthesize formyl-methionine (fMet)-containing proteins not only in mitochondria but also in the cytosol to some extent. Our previous study revealed substantial upregulation of N-terminal (Nt)-fMet-containing proteins in the cytosol of SW480 colorectal cancer cells. However, the functional and pathophysiological implications remain unclear. Here, we demonstrated that removal of the Nt-formyl moiety of Nt-fMet-containing proteins (via expressing Escherichia coli PDF peptide deformylase) resulted in a dramatic increase in the proliferation of SW480 colorectal cancer cells. This proliferation coincided with the acquisition of cancer stem cell features, including reduced cell size, enhanced self-renewal capacity, and elevated levels of the cancer stem cell surface marker CD24 and pluripotent transcription factor SOX2. Furthermore, deformylation of Nt-fMet-containing proteins promoted the tumorigenicity of SW480 colorectal cancer cells in an in vivo xenograft mouse model. Taken together, these findings suggest that cytosolic deformylation has a tumor-enhancing effect, highlighting its therapeutic potential for cancer treatment.

The Loss of an Orphan Nuclear Receptor NR2E3 Augments Wnt/β-catenin Signaling via Epigenetic Dysregulation that Enhances Sp1-β catenin-p300 Interactions in Hepatocellular Carcinoma.

The orphan nuclear receptor NR2E3 (Nuclear receptor subfamily 2 group E, Member 3) is an epigenetic player that modulates chromatin accessibility to activate p53 during liver injury. Nonetheless, a precise tumor suppressive and epigenetic role of NR2E3 in hepatocellular carcinoma (HCC) development remains unclear. HCC patients expressing low NR2E3 exhibit unfavorable clinical outcomes, aligning with heightened activation of the Wnt/β-catenin signaling pathway. The murine HCC models utilizing NR2E3 knockout mice consistently exhibits accelerated liver tumor formation accompanied by enhanced activation of Wnt/β-catenin signaling pathway and inactivation of p53 signaling. At cellular level, the loss of NR2E3 increases the acquisition of aggressive cancer cell phenotype and tumorigenicity and upregulates key genes in the WNT/β-catenin pathway with increased chromatin accessibility. This event is mediated through increased formation of active transcription complex involving Sp1, β-catenin, and p300, a histone acetyltransferase, on the promoters of target genes. These findings demonstrate that the loss of NR2E3 activates Wnt/β-catenin signaling at cellular and organism levels and this dysregulation is associated with aggressive HCC development and poor clinical outcomes. In summary, NR2E3 is a novel tumor suppressor with a significant prognostic value, maintaining epigenetic homeostasis to suppress the Wnt/β-catenin signaling pathway that promotes HCC development.

Discovery of LLC355 as an Autophagy-Tethering Compound for the Degradation of Discoidin Domain Receptor 1.

Discoidin domain receptor 1 (DDR1) is a potential target for cancer drug discovery. Although several DDR1 kinase inhibitors have been developed, recent studies have revealed the critical roles of the noncatalytic functions of DDR1 in tumor progression, metastasis, and immune exclusion. Degradation of DDR1 presents an opportunity to block its noncatalytic functions. Here, we report the discovery of the DDR1 degrader LLC355 by employing autophagosome-tethering compound technology. Compound LLC355 efficiently degraded DDR1 protein with a DC50 value of 150.8 nM in non-small cell lung cancer NCI-H23 cells. Mechanistic studies revealed compound LLC355 to induce DDR1 degradation via lysosome-mediated autophagy. Importantly, compound LLC355 potently suppressed cancer cell tumorigenicity, migration, and invasion and significantly outperformed the corresponding inhibitor 1. These results underline the therapeutic advantage of targeting the noncatalytic function of DDR1 over inhibition of its kinase activity.

Abstract PO5-24-04: Fibronectin, DHPS and SLC3A2 Signaling Cooperate to Control Tumor Spheroid Growth, Subcellular eIF5A1/2 Distribution and CDK4/6 Inhibitor Resistance

Abstract Extracellular matrix (ECM) protein expression/deposition within and stiffening of the breast cancer (BC) microenvironment, facilitates disease progression and correlates with poor patient survival. However, the mechanisms by which ECM components control tumorigenic behaviors and responses to therapeutic intervention remain poorly understood. Fibronectin (FN) is a major ECM protein controlling multiple processes related to cancer metastasis. In this regard, we previously reported that DHPS-dependent hypusination of eIF5A1/2 is necessary for fibronectin-mediated BC metastasis and epithelial to mesenchymal transition (EMT). Here, we explored the clinical significance of an interactome generated using hypusination pathway components and markers of intratumoral heterogeneity. Solute carrier 3A2 (SLC3A2 or CD98hc) stood out as an indicator of poor overall survival among patients with basal-like BCs that express elevated levels of DHPS. We subsequently discovered that blockade or knockdown (KD) of DHPS or SLC3A2 reduced BC spheroid growth. Interestingly, spheroids stimulated with exogenous fibronectin were less sensitive to inhibition of either DHPS or SLC3A2 – an effect that could be abrogated by dual DHPS/SLC3A2 blockade or KD. In this regard, we observed that inhibition of both SLC3A2 and DHPS reduced total and hypusinated eIF5A1/2 levels most effectively. We further discovered that a subset of BC cells responded to fibronectin by increasing cytoplasmic localization of eIF5A1/2. Notably, these fibronectin-induced subcellular localization phenotypes correlated with a G0/G1 cell cycle arrest. Fibronectin-treated BC cells responded to dual DHPS/SLC3A2 blockade by shifting eIF5A1/2 localization back to a nucleus-dominant state, suppressing proliferation and further arresting cells in the G2/M phase of the cell cycle. Finally, we observed that dual DHPS/SLC3A2 inhibition increased the sensitivity of both Rb-negative and -positive BC cells to the CDK4/6 inhibitor palbociclib. Taken together, these data identify an uncharacterized mechanism through which extracellular fibronectin controls cancer cell tumorigenicity by modulating subcellular eIF5A1/2 localization. These findings provide prognostic/therapeutic utility for targeting the cooperative DHPS/SLC3A2 signaling axis to improve BC treatment responses. Citation Format: Cameron Geller, Joanna Maddela, Gabriela Ortiz-Soto, Ranel Tuplano, Farhana Runa, Yvess Adamian, Robert Güth, Luke Tomaneng, Joseph Cantor, Jonathan A. Kelber. Fibronectin, DHPS and SLC3A2 Signaling Cooperate to Control Tumor Spheroid Growth, Subcellular eIF5A1/2 Distribution and CDK4/6 Inhibitor Resistance [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-24-04.

MiR-200-mediated inactivation of cancer-associated fibroblasts via targeting of NRP2-VEGFR signaling attenuates lung cancer invasion and metastasis

Cancer-associated fibroblasts (CAFs) play a substantial role in promoting cancer cell motility, drug resistance, angiogenesis, and metastasis; therefore, extensive research has been conducted to determine their mode of activation. We aimed to identify whether miRNA-200 (miR-200), a widely recognized suppressor of epithelial-mesenchymal transition, prevents CAFs from promoting cancer progression. Overexpression of miR-200 prevented CAFs from promoting lung cancer cell migration, invasion, tumorigenicity, and metastasis. Additionally, miR-200 suppressed the ability of CAFs to recruit and polarize macrophages toward the M2 phenotype as well as the migration and tube formation of vascular endothelial cells. NRP2, a co-receptor of VEGFR, was confirmed to be a target of miR-200, which mediates the functional activity of miR-200 in CAFs. NRP2-VEGFR signaling facilitates the secretion of VEGFD and PTN from CAFs, leading to the activation of cancer cell migration and invasion. These findings suggest that miR-200 remodels CAFs to impede cancer progression and metastasis and that miR-200 and NRP2 are potential therapeutic targets in the treatment of lung cancer.

Deletion of PTP4A3 phosphatase in high grade serous ovarian cancer cells decreases tumorigenicity and produces marked changes in intracellular signaling pathways and cytokine release.

The oncogenic protein tyrosine phosphatase PTP4A3 is frequently overexpressed in human ovarian cancers and is associated with poor patient prognosis. PTP4A3 is thought to regulate multiple oncogenic signaling pathways, including STAT3, SRC, and ERK. The objective of this study was to generate ovarian cancer cells with genetically depleted PTP4A3; to assess their tumorigenicity; to examine their cellular phenotype; and to uncover changes in their intracellular signaling pathways and cytokine release profiles. Genetic deletion of PTP4A3 using CRISPR/Cas9 enabled the generation of individual clones derived from single cells isolated from the polyclonal knockout population. We observed a >90% depletion of PTP4A3 protein levels by Western blotting in the clonal cell lines compared to the sham transfected wildtype population. The wildtype and polyclonal knockout cell lines shared similar monolayer growth rates, while the isolated clonal populations 2B4, 3C9, and 3C12 exhibited significantly lower monolayer growth characteristics consistent with their lower PTP4A3 levels. The clonal PTP4A3 knockout cell lines also had substantially lower in vitro colony formation efficiencies compared to the wildtype cells and were less tumorigenic in vivo The clonal knockout cells were markedly less responsive to IL-6-stimulated migration in a scratch wound assay compared to the wildtype cells. Antibody microarray assays documented differences in cytokine release and intracellular phosphorylation patterns in the PTP4A3 deleted clones. Bioinformatic network analyses indicated alterations in cellular signaling nodes. These biochemical changes could ultimately form the foundation for pharmacodynamic endpoints useful for emerging anti-PTP4A3 therapeutics. Significance Statement Clones of high grade serous ovarian cancer cells were isolated in which the oncogenic phosphatase PTP4A3 was deleted using CRISPR/Cas9 methodologies. The PTP4A3 null cells exhibited loss of in vitro proliferation, colony formation, and migration, and reduced in vivo tumorigenesis. Marked differences in intracellular protein phosphorylation and cytokine release were seen. The newly developed PTP4A3 knockout cells should provide useful tools to probe the role of PTP4A3 phosphatase in ovarian cancer cell survival, tumorigenicity and cell signaling.

Abstract 3011: The loss of an orphan nuclear receptor NR2E3 augments Wnt/β-Catenin signaling via epigenetic dysregulation that links to the Sp1-β catenin-p300 interactions in hepatocellular carcinoma

Abstract Hepatocellular carcinoma (HCC) stands as the fourth leading cause of global cancer-related mortality due to late-stage detection, tumor heterogeneity, and drug resistance. The pivotal role of epigenetic factors in HCC development and progression necessitates the identification of critical epigenetic regulators. The orphan nuclear receptor NR2E3 (Nuclear receptor subfamily 2 group E, Member 3), primarily associated with retinal development, has emerged as a potential tumor suppressor. Earlier studies showed that the loss of NR2E3 leads to epigenetic repression of the estrogen receptor α (ER) through the involvement of Lysine Specific histone Demethylase 1 (LSD1). NR2E3 also forms a transcriptional complex with Sp1, governing the aryl hydrocarbon receptor (AHR) expression, a crucial factor in liver xenobiotic metabolism. In vivo, NR2E3 ablation results in p53 inactivation and severe liver injuries when exposed to liver toxicants, highlighting its role in activating p53. Nonetheless, the precise tumor suppressive and epigenetic role of NR2E3 in HCC remains unclear. HCC patients expressing low NR2E3 exhibit unfavorable clinical outcomes, aligning with heightened activation of the Wnt/β-catenin signaling pathway. The murine HCC models utilizing NR2E3 knockout mice show accelerated liver tumor formation and progression accompanied by enhanced activation of the Wnt/β-catenin signaling pathway and inactivation of the p53 signaling pathway. At a cellular level, losing NR2E3 increases the acquisition of aggressive cancer cell phenotype and tumorigenicity and upregulates vital genes in the Wnt/β-catenin pathway with enhanced chromatin accessibility. This event is mediated through the increased formation of active transcription complex involving Sp1, β-catenin, and p300, a histone acetyltransferase, on the promoters of target genes. Correspondingly, treatment of p300 inhibitor C646 decreased the expression of critical genes in the Wnt/β-catenin signaling pathway. These findings demonstrate that the loss of NR2E3 promotes Wnt/β-catenin signaling activation at cellular, organismal, and clinical levels. In summary, NR2E3 is a novel tumor suppressor that maintains epigenetic homeostasis, thereby preventing activation of Wnt/β-catenin signaling that promotes HCC formation. Citation Format: Yuet-Kin Leung, Sung-Gwon Lee, Jiang Wang, Shuk-Mei Ho, Nancy Rusch, Chungoo Park, Kyounghyun Kim. The loss of an orphan nuclear receptor NR2E3 augments Wnt/β-Catenin signaling via epigenetic dysregulation that links to the Sp1-β catenin-p300 interactions in hepatocellular carcinoma [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 3011.

GFP Transfection Alters Protein Expression Patterns in Prostate Cancer Cells: A Proteomic Study.

Green Fluorescent Protein is widely used as a cellular marker tool, but its potential influence on cells has been questioned. Although the potential off-target effects of GFP on tumor cells have been studied to some extent, the findings at the molecular level are insufficient to explain the effect of GFP expression on the tumorigenic capacity of cancer cells. Here, we aimed to investigate the effect of GFP expression on the tumorigenicity of PC3 prostate cancer cells. Using GFP-expressing and wild-type PC-3 cells, xenograft models were generated in athymic BALB/C mice. To identify differentially expressed proteins, the change in cells proteome was investigated by label-free quantification with nano-high performance liquid chromatography to tandem mass spectrometry (nHPLC-MS/MS). Proteins that showed significantly altered expression levels were evaluated using the bioinformatics tools. Unlike the wild-type PC-3 cells, GFP-expressing cells failed to develop tumor. Comparative proteome analysis of GFP-expressing cells with WT PC-3 cells revealed a total of 216 differentially regulated proteins, of which 98 were upregulated and 117 were downregulated. Upon GFP expression, differential changes in several pathways including the immune system, translational machinery, energy metabolism, elements of cytoskeletal and VEGF signaling pathway were observed. Therefore, care should be taken into account to prevent reporting deceitful mechanisms generated from studies utilizing GFP.

Interconversion of Cancer Cells and Induced Pluripotent Stem Cells.

Cancer cells, especially cancer stem cells (CSCs), share many molecular features with induced pluripotent stem cells (iPSCs) that enable the derivation of induced pluripotent cancer cells by reprogramming malignant cells. Conversely, normal iPSCs can be converted into cancer stem-like cells with the help of tumor microenvironment components and genetic manipulation. These CSC models can be utilized in oncogenic initiation and progression studies, understanding drug resistance, and developing novel therapeutic strategies. This review summarizes the role of pluripotency factors in the stemness, tumorigenicity, and therapeutic resistance of cancer cells. Different methods to obtain iPSC-derived CSC models are described with an emphasis on exposure-based approaches. Culture in cancer cell-conditioned media or cocultures with cancer cells can convert normal iPSCs into cancer stem-like cells, aiding the examination of processes of oncogenesis. We further explored the potential of reprogramming cancer cells into cancer-iPSCs for mechanistic studies and cancer dependencies. The contributions of genetic, epigenetic, and tumor microenvironment factors can be evaluated using these models. Overall, integrating iPSC technology into cancer stem cell research holds significant promise for advancing our knowledge of cancer biology and accelerating the development of innovative and tailored therapeutic interventions.

A comprehensive review on lncRNA LOXL1-AS1: molecular mechanistic pathways of lncRNA LOXL1-AS1 in tumorigenicity of cancer cells.

Long non-coding RNAs (lncRNAs) are versatile RNAs that regulate various cellular processes, such as gene regulation, by acting as signals, decoys, guides, and scaffolds. A novel recognized lncRNA, LOXL1-antisense RNA 1 (LOXL1-AS1), is dysregulated in some diseases, including cancer, and acts as an oncogenic lncRNA in many types of cancer cells. Upregulation of LOXL1-AS1 has been involved in proliferation, migration, metastasis, and EMT, as well as inhibiting apoptosis in cancer cells. Most importantly, the malignant promoting activity of LOXL1-AS1 can be mostly mediated by sequestering specific miRNAs and inhibiting their binding to the 3´UTR of their target mRNAs, thereby indirectly regulating gene expression. Additionally, LOXL1-AS1 can decoy transcription factors and proteins and prevent their binding to their regulatory regions, inhibiting their mechanistic activity on the regulation of gene expression and signaling pathways. This review presents the mechanistic pathways of the oncogenic role of LOXL1-AS1 by modulating its target miRNAs and proteins in various cancer cells. Having information about the molecular mechanisms regulated by LOXL1-AS1 in cancer cells can open ways to find out particular prognostic biomarkers, as well as discover novel therapeutic approaches for different types of cancer.

Enhancement of Tumorigenicity, Spheroid Niche, and Drug Resistance of Pancreatic Cancer Cells in Three-Dimensional Culture System.

The three-dimensional (3D) cell culture technique has been applied comprehensively as a variable platform for medical research, biochemical signal pathway analysis, and evaluation of anti-tumor treatment response due to an excellent recapitulation of a tumor microenvironment (TME) in the in vitro cultured cancer cells. Pancreatic cancer (PaC) is one of the toughest malignancies with a complex TME and refractory treatment response. To comprehensively study the TME of PaC, there is an eager need to develop a 3D culture model to decompose the cellular components and their cross interactions. Herein, we establish a 3D PaC culture system with cancer stem cell (CSC) and scalability properties. To validate our model, we tested the individual PaC cell and the combined effects with cancer-associated fibroblasts (CAFs) on cancer tumorigenicity, the cellular interaction through the CXCR3/CXCL10 axis, and cellular responses reflection of anti-cancer treatments. With the help of our 3D technology, a simulated malignant spheroid with important stromal populations and TME physiochemical properties may be successfully recreated. It can be used in a wide range of preclinical research and helpful in advancing basic and translational cancer biology.

Continuous topical application of microencapsulated recombinant human epidermal growth factor does not promote the progression of established melanoma in animals

Microencapsulated epidermal growth factor (EGF) device has been applied topically for the management of several types of wounds to accelerate wound healing and prevent scar formation. However, it remains unclear whether such EGF device induced neoplastic transformation in the skin. In this study, we exploited a well-established murine B16-F10 melanoma model, coupled with MTT viability and colony formation assays, to investigate the influence of microencapsulated recombinant EGF (Me-EGF; brand name NewEpi®) and its ingredients on the tumorigenicity of skin cancer cells in vitro and in vivo. The results indicated that Me-EGF did not stimulate the viability nor the anchorage-dependent growth of B16-F10 melanoma cells. Western blot analysis showed that Me-EGF treatment increased the total and phosphorylated EGFR expression without affecting the HER2 expression in B16-F10 melanoma cells. In mice bearing established B16-F10 melanoma, continuous application of Me-EGF for 14 days did not enhance the melanoma tumor burden compared with control groups. Immunohistochemical analysis also revealed the similar expression of proliferative index Ki-67 between Me-EGF-treated melanoma and other groups. Altogether, these results suggest that the application of Me-EGF device did not promote the oncogenic potential of B16-F10 melanoma in vitro and in vivo.

Reprogramming and multi-lineage transdifferentiation attenuate the tumorigenicity of colorectal cancer cells

Significant advances have been made in reprogramming various somatic cells into induced pluripotent stem cells (iPSCs) and in multi-lineage differentiation (transdifferentiation) into different tissues. These manipulable transdifferentiating techniques may be applied in cancer therapy. Limited works have been reported that cancer cell malignancy can be switched to the benign phenotypes through reprogramming techniques. Here, we reported that two colorectal cancer (CRC) cell lines (DLD1, HT29) could be reprogrammed into iPSCs (D-iPSCs, H-iPSCs). D- and H-iPSCs showed reduced tumorigenesis. Furthermore, we successfully induced D- and H-iPSCs differentiation into terminally differentiated cell types such as cardiomyocyte, neuron, and adipocyte-like cells. Impressively, the differentiated cells exhibited further attenuated tumorigenesis in vitro and in vivo. RNA-Seq further indicated that epigenetic changes occurred after reprogramming and transdifferentiation that caused reduce tumorigenicity. Overall, our study indicated that CRC cells can be reprogrammed and further differentiate to terminally differentiated lineages with attenuation of their malignancy in vitro and in vivo. The current work sheds light on a potential multi-lineage differentiation therapeutic strategy for colorectal cancer.

LncRNA HOTAIR down-expression inhibits the invasion and tumorigenicity of epithelial ovarian cancer cells by suppressing TGF-β1 and ZEB1

BackgroundEpithelial ovarian cancer (EOC) is a pathological type with a higher mortality rate among gynecological cancers today. Long-chain noncoding RNAs (lncRNAs) can regulate the transcription and expression of cellular genes. However, the downstream molecules regulated by lncRNA HOTAIR have not been well studied. The effects of downregulated lncRNA HOTAIR on EOC invasiveness and tumorigenicity in nude mice, along with TGF- β1 and ZEB1 in epithelial ovarian cancer cells, need to be investigated in further research.ResultsRT-qPCR was used to detect lncRNA HOTAIR and TGF-β1 and ZEB1 mRNA expression in EOC SKOV3 cells. The expression of lncRNA HOTAIR in SKOV3 cells transfected with the recombinant shHOTAIR interference plasmid was significantly lower than that of the negative control. Compared with the negative control, the matrix gel invasion ability of shHOTAIR SKOV3 cells in vitro and their tumorigenicity in nude mice were significantly reduced. Moreover, compared with the control, the expression of ZEB1 protein in shHOTAIR-SKOV3 xenograft tumors was significantly reduced. Downregulation of lncRNA HOTAIR expression significantly reduced TGF-β1 and ZEB1 mRNA expression, but increased the expression of E-cadherin mRNA. In summary, downregulated lncRNA HOTAIR in EOC SKOV3 cells transfected with shHOTAIR can inhibit TGF-β1, reduce ZEB1, increase E-cadherin, and significantly reduce the invasiveness and tumorigenicity of ovarian epithelial cancer SKOV3 cells.ConclusionsThese results suggest that the lncRNA HOTAIR may be an effective target for the treatment of human EOC.

The Tumorigenicity of Breast Cancer Cells Is Reduced upon Treatment with Small Extracellular Vesicles Isolated from Heparin Treated Cell Cultures.

As a member of the HPSG family, heparin is often used as a specific probe of their role in cell physiology; indeed, we have previously shown a reduction in the tumorigenicity of breast cancer cells when cultured in its presence. However, a partial reversal of the anti-tumorigenic effect occurred when the treated cells were cultured in fresh medium without heparin, which led us to consider whether a more persistent effect could be achieved by treatment of the cells with small extracellular vesicles (sEV) from heparin-treated cells. The tumorigenicity was analyzed using sEV isolated from the culture medium of heparin-treated MCF-7 and MDA-MB231 breast cancer cells (sEV-HT) or from conditioned medium following the termination of treatment (heparin discontinued, sEV-HD). Tumorigenicity was reduced in cells cultured in the presence of sEV-HT compared to that of cells cultured in the presence of sEV from untreated cells (sEV-Ctrl). sEV-HD were also observed to exert an anti-tumorigenic effect on the expression of pro-tumorigenic and cell cycle regulatory proteins, as well as signaling activities when added to fresh cultures of MCF-7 and MDA-MB231 cells. The anti-tumorigenic activity of the heparin-derived sEV may arise from observed changes in the miRNA content or from heparin, which was observed to be bound to the sEV. sEV may constitute a relatively stable reservoir of circulating heparin, allowing heparin activity to persist in the circulation even after therapy has been discontinued. These findings can be considered as a special additional pharmacological characteristic of heparin clinical therapy.