RhoA knockout fibroblasts lose tumor-inhibitory capacity in vitro and promote tumor growth in vivo

Fibroblasts are a main player in the tumor-inhibitory microenvironment. Upon tumor initiation and progression, fibroblasts can lose their tumor-inhibitory capacity and promote tumor growth. The molecular mechanisms that underlie this switch have not been defined completely. Previously, we identified four proteins overexpressed in cancer-associated fibroblasts and linked to Rho GTPase signaling. Here, we show that knocking out the Ras homolog family member A (RhoA) gene in normal fibroblasts decreased their tumor-inhibitory capacity, as judged by neighbor suppression in vitro and accompanied by promotion of tumor growth in vivo. This also induced PC3 cancer cell motility and increased colony size in 2D cultures. RhoA knockout in fibroblasts induced vimentin intermediate filament reorganization, accompanied by reduced contractile force and increased stiffness of cells. There was also loss of wide F-actin stress fibers and large focal adhesions. In addition, we observed a significant loss of α-smooth muscle actin, which indicates a difference between RhoA knockout fibroblasts and classic cancer-associated fibroblasts. In 3D collagen matrix, RhoA knockout reduced fibroblast branching and meshwork formation and resulted in more compactly clustered tumor-cell colonies in coculture with PC3 cells, which might boost tumor stem-like properties. Coculturing RhoA knockout fibroblasts and PC3 cells induced expression of proinflammatory genes in both. Inflammatory mediators may induce tumor cell stemness. Network enrichment analysis of transcriptomic changes, however, revealed that the Rho signaling pathway per se was significantly triggered only after coculturing with tumor cells. Taken together, our findings in vivo and in vitro indicate that Rho signaling governs the inhibitory effects by fibroblasts on tumor-cell growth.

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Tumor quiescence: elevating SOX2 in diverse tumor cell types downregulates a broad spectrum of the cell cycle machinery and inhibits tumor growth

BMC Cancer ◽

10.1186/s12885-020-07370-7 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Ethan P. Metz ◽

Erin L. Wuebben ◽

Phillip J. Wilder ◽

Jesse L. Cox ◽

Kaustubh Datta ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Tumor Growth ◽

Tumor Cell ◽

Tumor Cells ◽

Molecular Mechanisms ◽

Cell Types ◽

Cell Cycle Machinery

Abstract Background Quiescent tumor cells pose a major clinical challenge due to their ability to resist conventional chemotherapies and to drive tumor recurrence. Understanding the molecular mechanisms that promote quiescence of tumor cells could help identify therapies to eliminate these cells. Significantly, recent studies have determined that the function of SOX2 in cancer cells is highly dose dependent. Specifically, SOX2 levels in tumor cells are optimized to promote tumor growth: knocking down or elevating SOX2 inhibits proliferation. Furthermore, recent studies have shown that quiescent tumor cells express higher levels of SOX2 compared to adjacent proliferating cells. Currently, the mechanisms through which elevated levels of SOX2 restrict tumor cell proliferation have not been characterized. Methods To understand how elevated levels of SOX2 restrict the proliferation of tumor cells, we engineered diverse types of tumor cells for inducible overexpression of SOX2. Using these cells, we examined the effects of elevating SOX2 on their proliferation, both in vitro and in vivo. In addition, we examined how elevating SOX2 influences their expression of cyclins, cyclin-dependent kinases (CDKs), and p27Kip1. Results Elevating SOX2 in diverse tumor cell types led to growth inhibition in vitro. Significantly, elevating SOX2 in vivo in pancreatic ductal adenocarcinoma, medulloblastoma, and prostate cancer cells induced a reversible state of tumor growth arrest. In all three tumor types, elevation of SOX2 in vivo quickly halted tumor growth. Remarkably, tumor growth resumed rapidly when SOX2 returned to endogenous levels. We also determined that elevation of SOX2 in six tumor cell lines decreased the levels of cyclins and CDKs that control each phase of the cell cycle, while upregulating p27Kip1. Conclusions Our findings indicate that elevating SOX2 above endogenous levels in a diverse set of tumor cell types leads to growth inhibition both in vitro and in vivo. Moreover, our findings indicate that SOX2 can function as a master regulator by controlling the expression of a broad spectrum of cell cycle machinery. Importantly, our SOX2-inducible tumor studies provide a novel model system for investigating the molecular mechanisms by which elevated levels of SOX2 restrict cell proliferation and tumor growth.

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Gallbladder cancer-associated fibroblasts promote vasculogenic mimicry formation and tumor growth in gallbladder cancer via upregulating the expression of NOX4, a poor prognosis factor, through IL-6-JAK-STAT3 signal pathway

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-020-01742-4 ◽

2020 ◽

Vol 39 (1) ◽

Author(s):

Mu-Su Pan ◽

Hui Wang ◽

Kamar Hasan Ansari ◽

Xin-Ping Li ◽

Wei Sun ◽

...

Keyword(s):

Tumor Growth ◽

Gallbladder Cancer ◽

Molecular Mechanism ◽

Poor Prognosis ◽

Vasculogenic Mimicry ◽

Tube Formation ◽

Signal Pathway ◽

Cancer Associated Fibroblasts

Abstract Background Cancer-associated fibroblasts (CAFs) and vasculogenic mimicry (VM) play important roles in the occurrence and development of tumors. However, the relationship between CAFs and VM formation, especially in gallbladder cancer (GBC) has not been clarified. In this study, we investigated whether gallbladder CAFs (GCAFs) can promote VM formation and tumor growth and explored the underlying molecular mechanism. Methods A co-culture system of human GBC cells and fibroblasts or HUVECs was established. VM formation, proliferation, invasion, migration, tube formation assays, CD31-PAS double staining, optic/electron microscopy and tumor xenograft assay were used to detect VM formation and malignant phenotypes of 3-D co-culture matrices in vitro, as well as the VM formation and tumor growth of xenografts in vivo, respectively. Microarray analysis was used to analyze gene expression profile in GCAFs/NFs and VM (+)/VM (−) in vitro. QRT-PCR, western blotting, IHC and CIF were used to detected NOX4 expression in GCAFs/NFs, 3-D culture/co-culture matrices in vitro, the xenografts in vivo and human gallbladder tissue/stroma samples. The correlation between NOX4 expression and clinicopathological and prognostic factors of GBC patients was analyzed. And, the underlying molecular mechanism of GCAFs promoting VM formation and tumor growth in GBC was explored. Results GCAFs promote VM formation and tumor growth in GBC; and the finding was confirmed by facts that GCAFs induced proliferation, invasion, migration and tube formation of GBC cells in vitro, and promoted VM formation and tumor growth of xenografts in vivo. NOX4 is highly expressed in GBC and its stroma, which is the key gene for VM formation, and is correlated with tumor aggression and survival of GBC patients. The GBC patients with high NOX4 expression in tumor cells and stroma have a poor prognosis. The underlying molecular mechanism may be related to the upregulation of NOX4 expression through paracrine IL-6 mediated IL-6/JAK/STAT3 signaling pathway. Conclusions GCAFs promote VM formation and tumor growth in GBC via upregulating NOX4 expression through the activation of IL-6-JAK-STAT3 signal pathway. NOX4, as a VM-related gene in GBC, is overexpressed in GBC cells and GCAFs, which is related to aggression and unfavorable prognosis of GBC patients.

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Abstract 536: Mesenchymal stromal cells promote tumor growth both in vitro and in vivo

10.1158/1538-7445.am10-536 ◽

2010 ◽

Author(s):

Kazuhiro Suzuki ◽

Makoto Origuchi ◽

Masahiko Kanehira ◽

Ruowen Sun ◽

Takenori Takahata ◽

...

Keyword(s):

Tumor Growth ◽

Mesenchymal Stromal Cells ◽

Stromal Cells ◽

Promote Tumor Growth

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Thrombin Enhances Spontaneous Tumor Growth and Cell Cycle Activation by Downregulation of p27Kip1 and Upregulation of Skp2 and MiR-222

Blood ◽

10.1182/blood.v112.11.396.396 ◽

2008 ◽

Vol 112 (11) ◽

pp. 396-396

Author(s):

Liang Hu ◽

Sherif Ibrahim ◽

Cynthia Liu ◽

Jeffrey Skaar ◽

Michelle Pagano ◽

...

Keyword(s):

Cell Cycle ◽

Growth Factors ◽

Cell Growth ◽

Tumor Growth ◽

Tumor Cell ◽

Tumor Volume ◽

S Phase ◽

Down Regulation

Abstract Although it has been generally accepted that hypercoagulability contributes to enhancing tumor growth via generation of thrombin (Cancer Cell10:355, 2006), it has not been rigorously proven, nor has the mechanism been established at the cell cycle level. Previous studies have employed thrombin-treated tumor cell lines in vitro and in vivo. In vitro studies were performed in the presence of serum which contains a panoply of growth factors. In vivo studies have used huge non-pathologic concentrations of tumor cells injected into the flank, organ or blood of a mouse. In these situations, tumor growth could be a result of thrombin-induced angiogenesis. We therefore employed a transgenic mouse prostate cancer model (TRAMP) programmed to develop prostate CA over a period of 140–175 days. We treated these animals with thrombin to induce hypercoagulability or hirudin to inhibit endogenous thrombin production, to determine whether thrombin regulates this process independent of angiogenesis. Repetitive thrombin injection enhanced prostate tumor volume 6–8 fold (p<0.04). Repetitive hirudin decreased tumor volume 13–24 fold (p<0.04) via its effect on generated endogenous thrombin, n=6. Thrombin enhanced the production of several vascular growth factors and receptors 2.5 – 3 fold in the liver (VEGF, KDR, ANG-2, Tie2, GRO-1, CD31) and enhanced angiogenesis in the liver, n=3–4. Thrombin had no effect on tumor angiogenesis. Thus, the thrombin-induced spontaneous tumor growth was independent of angiogenesis. We next turned our attention to cell cycle regulators in serum-starved (72 hr) Go-synchronized LNcap prostate CA cells, employing Brdu and Propidium iodide staining. Addition of thrombin (0.5 u/ml) or its PAR-1 receptor agonist, TFLLRN (100 uM) had the same effect as androgen containing serum, inducing cells to leave Go, enter G1 and progress to S-phase. At 8 hrs the number of S-phase cells increased dramatically for both the serum (29 fold) as well as thrombin-treated cells (48 fold), n=3. Similar observations were noted in a Glioblastoma cell line, T98G. We further analyzed the effect of thrombin by performing immunoblots on cell cycle components mediated during cell growth and proliferation. In synchronized Go cells, levels of p27Kip1, a cyclin-dependent kinase inhibitor are high, while levels of cyclins D1 and A, the activation subunits for cyclin-dependent kinases are low. Both thrombin or serum addition led to down-regulation of p27Kip1 with concomitant induction of Skp2, the E3 ubiquitin ligase for p27Kip1. Cyclins D1 and A are induced by similar kinetics, indicating entry into S-phase by 8 hrs. Since p27Kip1 appears to be a rate-limiting down-regulator of the cell cycle (absent with high tumor grade and predicts poor prognosis), we confirmed its role by testing the effect of thrombin or TFLLRN by transfecting p27Kip1 in LNcap cells. This transfection completely prevented the cell cycle stimulation induced by these agonists. A similar approach was used with Skp2 knock down (KD), a negative down-regulator of p27Kip1. KD of Skp2 (over expressed in numerous cancers) completely prevented cell cycle progression induced by thrombin/TFLLRN. MiRNA 222 (upregulated in many cancers) is another down-regulator of p27Kip1. Further analysis following thrombin treatment revealed a robust upregulation at 4 and 8 hrs, providing further proof for the role of thrombin in down-regulating p27Kip1 and stimulating tumor cell entrance into S-phase. Thus, 1) Thrombin enhances spontaneous prostate cell growth in vivo in the absence of enhanced angiogenesis; 2) Thrombin activates the tumor cell cycle by stimulating the down-regulation of p27Kip1 through the upregulation of Skp2 and MiRNA 222.

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FRA-1 Proto-Oncogene Induces Lung Epithelial Cell Invasion and Anchorage-Independent Growth In vitro, but Is Insufficient to Promote Tumor Growth In vivo

Cancer Research ◽

10.1158/0008-5472.can-06-4687 ◽

2007 ◽

Vol 67 (13) ◽

pp. 6204-6211 ◽

Cited By ~ 52

Author(s):

Pavan Adiseshaiah ◽

Daniel J. Lindner ◽

Dhananjaya V. Kalvakolanu ◽

Sekhar P. Reddy

Keyword(s):

Epithelial Cell ◽

Tumor Growth ◽

Cell Invasion ◽

Lung Epithelial Cell ◽

Anchorage Independent Growth ◽

Promote Tumor Growth ◽

Lung Epithelial ◽

Epithelial Cell Invasion

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TUSC1, a Putative Tumor Suppressor Gene, Reduces Tumor Cell Growth In Vitro and Tumor Growth In Vivo

PLoS ONE ◽

10.1371/journal.pone.0066114 ◽

2013 ◽

Vol 8 (6) ◽

pp. e66114 ◽

Cited By ~ 15

Author(s):

Zhihong Shan ◽

Abbas Shakoori ◽

Sohrab Bodaghi ◽

Paul Goldsmith ◽

Jen Jin ◽

...

Keyword(s):

Cell Growth ◽

Tumor Suppressor ◽

Tumor Growth ◽

Tumor Cell ◽

Suppressor Gene ◽

Tumor Cell Growth ◽

Putative Tumor Suppressor Gene ◽

Putative Tumor Suppressor

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Independence of HIF1a and androgen signaling pathways in prostate cancer

10.1101/848424 ◽

2019 ◽

Author(s):

Maxine GB Tran ◽

Becky AS Bibby ◽

Lingjian Yang ◽

Franklin Lo ◽

Anne Warren ◽

...

Keyword(s):

Prostate Cancer ◽

Tumor Growth ◽

Signaling Pathways ◽

Cancer Progression ◽

Poor Prognosis ◽

Therapeutic Strategy ◽

Promote Tumor Growth ◽

Elevated Expression

AbstractAndrogen signaling drives prostate cancer progression and is a therapeutic target. Hypoxia/HIF1a signaling is associated with resistance to hormone therapy and a poor prognosis in patients treated with surgery or radiotherapy. It is not known whether the pathways operate in cooperation or independently. Using LNCaP cells with and without stable transfection of a HIF1a expression vector, we show that combined AR and HIF1a signaling promotes tumor growth in vitro and in vivo, and the capacity of HIF1a to promote tumor growth in the absence of endogenous androgen in vivo. Gene expression analysis identified 7 genes that were upregulated by both androgen and HIF1a. ChIP-Seq analysis showed that the AR and HIF/hypoxia signaling pathways function independently regulating the transcription of different genes with few shared targets. In clinical datasets elevated expression of 5 of the 7 genes was associated with a poor prognosis. Our findings suggest that simultaneous therapeutic inhibition of AR and HIF1a signaling pathways should be explored as a potential therapeutic strategy.

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Inhibition of Src and insulin/insulin-like growth factor-1 receptor (IR/IGF-1R) on tumors and bone turnover in prostate cancer (PCa) models in vivo compared with inhibition of either kinase alone.

Journal of Clinical Oncology ◽

10.1200/jco.2012.30.5_suppl.61 ◽

2012 ◽

Vol 30 (5_suppl) ◽

pp. 61-61

Author(s):

Farshid Dayyani ◽

Nila Parikh ◽

Jian H. Song ◽

John C. Araujo ◽

Joan M. Carboni ◽

...

Keyword(s):

Bone Turnover ◽

Tumor Growth ◽

Bone Turnover Markers ◽

Bone Destruction ◽

In Vivo Studies ◽

Pc3 Cells ◽

Turnover Markers ◽

Induced Apoptosis

61 Background: The Src and IGF-1R axes are aberrantly activated in both PCa and the microenvironment of bone metastases. Dasatinib and BMS-754807 are clinically promising small molecule inhibitors with high potency against Src family kinases (SFK) and IR/IGF-1R, respectively. Based on a phase I/II clinical trial in which 9/19 pts treated with docetaxel + dasatinib were increased in serum IGF-1 levels after one cycle, the aim of this study was to establish potential antitumor cooperativity of inhibiting both IGF-1R and Src in experimental PCa models in vitro and in mice. Methods: Inhibition of Src and IGF-1R pathways was accomplished by pharmacologic agents (dasatinib against Src and BMS-754807 against IR/IGF-1R) as well as by shRNA, in PC3 and LNCaP cells. In vivo studies were done after orthotopic and intratibial injection of PC3 cells in nude mice. Results: SFK inhibition decreased proliferation and migration of PCa cells whereas IGF-1R blockade induced apoptosis. All anti-tumor effects were enhanced by dual blockade. IGF-1 induced phosphorylation of Akt1 and 2. Only Akt 1 phosphorylation was decreased by dasatinib; whereas Akt 1 and 2 phosphorylation were completely abrogated by the combination. Dasatinib and BMS-754807 inhibited orthotopic in vivo tumor growth of PC3 cells more potently than either inhibitor alone. Similarly, intratibial tumor growth and bone destruction was significantly reduced with the drug combination, accompanied by a decrease in serum bone turnover markers alkaline phosphatase and N-telopeptide. Conclusions: Dual inhibition of Src and IGF-1R has greater anti-tumor effect in PCa cells compared to inhibiting either alone. In the presence of IGF-1, dasatinib and BMS-754807 are necessary to inhibit IGF-1-induced phosphorylation of Akt1 and 2 in tumor cells in culture. In intratibial models, decreased bone turnover markers in serum support the concept of targeting both the epithelial and bone microenvironment. The combination of dasatinib and BMS-754807 may be a rational therapeutic approach in PCa by blocking complementary processes of tumor growth and progression.

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