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Background: Current evidence implicates aberrant microRNA expression patterns in human malignancies; measurement of microRNA expression may have diagnostic and prognostic applications. Roles for microRNAs in head and neck squamous cell carcinomas (HNSCC) are largely unknown. HNSCC, a smoking-related cancer, is one of the most common malignancies worldwide but reliable diagnostic and prognostic markers have not been discovered so far. Some studies have evaluated the potential use of microRNA as biomarkers with clinical application in HNSCC.Methods: MicroRNA expression profile of oral squamous cell carcinoma samples was determined by means of DNA microarrays. We also performed gain-of-function assays for two differentially expressed microRNA using two squamous cell carcinoma cell lines and normal oral keratinocytes. The effect of the over-expression of these molecules was evaluated by means of global gene expression profiling and cell proliferation assessment.Results: Altered microRNA expression was detected for a total of 72 microRNAs. Among these we found well studied molecules, such as the miR-17-92 cluster, comprising potent oncogenic microRNA, and miR-34, recently found to interact with p53. HOX-cluster embedded miR-196a/b and miR-10b were up- and down-regulated, respectively, in tumor samples. Since validated HOX gene targets for these microRNAs are not consistently deregulated in HNSCC, we performed gain-of-function experiments, in an attempt to outline their possible role. Our results suggest that both molecules interfere in cell proliferation through distinct processes, possibly targeting a small set of genes involved in cell cycle progression.Conclusions: Functional data on miRNAs in HNSCC is still scarce. Our data corroborate current literature and brings new insights into the role of microRNAs in HNSCC. We also show that miR-196a and miR-10b, not previously associated with HNSCC, may play an oncogenic role in this disease through the deregulation of cell proliferation. The study of microRNA alterations in HNSCC is an essential step to the mechanistic understanding of tumor formation and could lead to the discovery of clinically relevant biomarkers. [ABSTRACT FROM AUTHOR]

Background: Colorectal cancer (CRC) is characterised by hypoxia, which activates gene transcription through hypoxia-inducible factors (HIF), as well as by expression of epidermal growth factor (EGF) and EGF receptors, targeting of which has been demonstrated to provide therapeutic benefit in CRC. Although EGF has been demonstrated to induce expression of angiogenic mediators, potential interactions in CRC between EGF-mediated signalling and the hypoxia/HIF pathway remain uncharacterised.Methods: PCR-based profiling was applied to identify angiogenic genes in Caco-2 CRC cells regulated by hypoxia, the hypoxia mimetic dimethyloxallylglycine (DMOG) and/or EGF. Western blotting was used to determine the role of HIF-1alpha, HIF-2alpha and MAPK cell signalling in mediating the angiogenic responses.Results: We identified a total of 9 angiogenic genes, including angiopoietin-like (ANGPTL) 4, ephrin (EFNA) 3, transforming growth factor (TGF) β1 and vascular endothelial growth factor (VEGF), to be upregulated in a HIF dependent manner in Caco-2 CRC cells in response to both hypoxia and the hypoxia mimetic dimethyloxallylglycine (DMOG). Stimulation with EGF resulted in EGFR tyrosine autophosphorylation, activation of p42/p44 MAP kinases and stabilisation of HIF-1α and HIF-2α proteins. However, expression of 84 angiogenic genes remained unchanged in response to EGF alone. Crucially, addition of DMOG in combination with EGF significantly increased expression of a further 11 genes (in addition to the 9 genes upregulated in response to either DMOG alone or hypoxia alone). These additional genes included chemokines (CCL-11/eotaxin-1 and interleukin-8), collagen type IV α3 chain, integrin β3 chain, TGFα and VEGF receptor KDR.Conclusion: These findings suggest that although EGFR phosphorylation activates the MAP kinase signalling and promotes HIF stabilisation in CRC, this alone is not sufficient to induce angiogenic gene expression. In contrast, HIF activation downstream of hypoxia/DMOG drives expression of genes such as ANGPTL4, EFNA3, TGFβ1 and VEGF. Finally, HIF activation synergises with EGF-mediated signalling to additionally induce a unique sub-group of candidate angiogenic genes. Our data highlight the complex interrelationship between tumour hypoxia, EGF and angiogenesis in the pathogenesis of CRC. [ABSTRACT FROM AUTHOR]

Background: TRAF3, a new tumor suppressor identified in human non-Hodgkin lymphoma (NHL) and multiple myeloma (MM), induces PKCδ nuclear translocation in B cells. The present study aimed to evaluate the therapeutic potential of two PKCδ activators, N-Benzyladriamycin-14-valerate (AD 198) and ingenol-3-angelate (PEP005), on NHL and MM.Methods: In vitro anti-tumor activities of AD 198 and PEP005 were determined using TRAF3-/- mouse B lymphoma and human patient-derived MM cell lines as model systems. In vivo therapeutic effects of AD 198 were assessed using NOD SCID mice transplanted with TRAF3-/- mouse B lymphoma cells. Biochemical studies were performed to investigate signaling mechanisms induced by AD 198 or PEP005, including subcellular translocation of PKCδ.Results: We found that AD 198 exhibited potent in vitro and in vivo anti-tumor activity on TRAF3-/- tumor B cells, while PEP005 displayed contradictory anti- or pro-tumor activities on different cell lines. Detailed mechanistic investigation revealed that AD 198 did not affect PKCδ nuclear translocation, but strikingly suppressed c-Myc expression and inhibited the phosphorylation of ERK, p38 and JNK in TRAF3-/- tumor B cells. In contrast, PEP005 activated multiple signaling pathways in these cells, including PKCδ, PKCα, PKCε, NF-κB1, ERK, JNK, and Akt. Additionally, AD198 also potently inhibited the proliferation/survival and suppressed c-Myc expression in TRAF3-sufficient mouse and human B lymphoma cell lines. Furthermore, we found that reconstitution of c-Myc expression conferred partial resistance to the anti-proliferative/apoptosis-inducing effects of AD198 in human MM cells.Conclusions: AD 198 and PEP005 have differential effects on malignant B cells through distinct biochemical mechanisms. Our findings uncovered a novel, PKCδ-independent mechanism of the anti-tumor effects of AD 198, and suggest that AD 198 has therapeutic potential for the treatment of NHL and MM involving TRAF3 inactivation or c-Myc up-regulation. [ABSTRACT FROM AUTHOR]

Background: An increase in cancer cell invasion and microvascular density is associated with a poorer prognosis for patients with endometrial cancer. In endometrial adenocarcinoma F-prostanoid (FP) receptor expression is elevated, along with its ligand prostaglandin (PG)F2α, where it regulates expression and secretion of a host of growth factors and chemokines involved in tumorigenesis. This study investigates the expression, regulation and role of a disintegrin and metalloproteinase with thrombospondin repeat 1 (ADAMTS1) in endometrial adenocarcinoma cells by PGF2α via the FP receptor. Methods: Human endometrium and adenocarcinoma tissues were obtained in accordance with Lothian Research Ethics Committee guidance with informed patient consent. Expression of ADAMTS1 mRNA and protein in tissues was determined by quantitative RT-PCR analysis and immunohistochemistry. Signal transduction pathways regulating ADAMTS1 expression in Ishikawa cells stably expressing the FP receptor to levels seen in endometrial cancer (FPS cells) were determined by quantitative RT-PCR analysis. In vitro invasion and proliferation assays were performed with FPS cells and human umbilical vein endothelial cells (HUVECs) using conditioned medium (CM) from PGF2α-treated FPS cells from which ADAMTS1 was immunoneutralised and/or recombinant ADAMTS1. The role of endothelial ADAMTS1 in endothelial cell proliferation was confirmed with RNA interference. The data in this study were analysed by T-test or ANOVA. Results: ADAMTS1 mRNA and protein expression is elevated in endometrial adenocarcinoma tissues compared with normal proliferative phase endometrium and is localised to the glandular and vascular cells. Using FPS cells, we show that PGF2α-FP signalling upregulates ADAMTS1 expression via a calmodulin-NFAT-dependent pathway and this promotes epithelial cell invasion through ECM and inhibits endothelial cell proliferation. Furthermore, we show that CM from FPS cells regulates endothelial cell ADAMTS1 expression in a rapid biphasic manner. Using RNA interference we show that endothelial cell ADAMTS1 also negatively regulates cellular proliferation. Conclusions: These data demonstrate elevated ADAMTS1 expression in endometrial adenocarcinoma. Furthermore we have highlighted a mechanism whereby FP receptor signalling regulates epithelial cell invasion and endothelial cell function via the PGF2α-FP receptor mediated induction of ADAMTS1. [ABSTRACT FROM AUTHOR]

Background: The treatment of Ewing sarcoma, an aggressive bone and soft tissue sarcoma, is associated with suboptimal outcomes and significant side-effects. Consequently, there is an urgent need to identify novel therapies that will improve outcomes for children and adults with Ewing sarcoma tumors while also decreasing treatment-related toxicities.Methods: We analyzed data from the PRISM drug repurposing screen, which tested the activity of 4518 drugs across 578 cancer cell lines, to identify drugs that selectively inhibit the growth of Ewing sarcoma cell lines. We then tested the effects of a top hit from the screen on cell proliferation, cell cycle progression, and activation of the DNA damage pathway using Ewing sarcoma cell lines. We also used a CRISPR/Cas9 gene knockout approach to investigate the role of Schlafen 11 (SLFN11), a restriction factor for DNA replication stress that is overexpressed in Ewing sarcoma tumors, in mediating the sensitivity of Ewing sarcoma cells to the drug.Results: We found that eltrombopag, an FDA-approved thrombopoietin-receptor agonist (TPO-RA) that is currently being evaluated as a treatment for chemotherapy-induced thrombocytopenia, inhibits the growth of Ewing sarcoma cell lines in vitro in proliferation and colony formation assays. However, from a mechanistic standpoint, the thrombopoietin receptor is not expressed in Ewing sarcoma cells and we show that eltrombopag impairs DNA replication and causes DNA damage in Ewing sarcoma cells by chelating iron, a known "off-target" effect of the drug. We also found that the sensitivity of Ewing sarcoma cells to eltrombopag is mediated, in part, by SLFN11, which regulates the cellular response to DNA replication stress.Conclusions: Ewing sarcoma cell lines are sensitive to eltrombopag and this drug could improve outcomes for patients with Ewing sarcoma tumors by both targeting the tumor, via chelation of iron and inhibition of DNA replication, and reducing chemotherapy-induced thrombocytopenia, via stimulation of the thrombopoietin receptor. [ABSTRACT FROM AUTHOR]

Background: Although great progress has been made in treatment regimens, cervical cancer remains as one of the most common cancer in women worldwide. Studies focusing on molecules that regulate carcinogenesis may provide potential therapeutic strategies for cervical cancer. B7-H6, an activating immunoligand expressed by several tumor cells, is known to activate NK cell-mediated cytotoxicity once engaged with its natural receptor NKp30. However, the opposite, that is, the effects in the tumor cell triggered by B7-H6 after interacting with NKp30 has not yet been well explored.Methods: In this study, we evaluated the surface expression of B7-H6 by flow cytometry. Later, we stimulated B7-H6 positive cervical cancer derived-cell lines (HeLa and SiHa) with recombinant soluble NKp30 (sNKp30) protein and evaluated biological effects using the impedance RTCA system for cell proliferation, the scratch method for cell migration, and flow cytometry for apoptosis. Cellular localization of B7-H6 was determined using confocal microscopy.Results: Notably, we observed that the addition of sNKp30 to the cervical cancer cell lines decreased tumor cell proliferation and migration rate, but had no effect on apoptosis. We also found that B7-H6 is selectively maintained in tumor cell lines, and that efforts to sort and purify B7-H6 negative or positive cells were futile, as negative cells, when cultured, regained the expression of B7-H6 and B7-H6 positive cells, when sorted and cultivated, lost a percentage of B7-H6 expression.Conclusions: Our results suggest that B7-H6 has an important, as of yet undescribed, role in the biology of the cervical tumor cells themselves, suggesting that this protein might be a promising target for anti-tumor therapy in the future. [ABSTRACT FROM AUTHOR]

Background: Hepatocellular carcinoma (HCC) is the leading cause of primary liver cancers. Surveillance of individuals at specific risk of developing HCC, early diagnostic markers, and new therapeutic approaches are essential to obtain a reduction in disease-related mortality. Apurinic/apyrimidinic endonuclease 1 (APE1) expression levels and its cytoplasmic localization have been reported to correlate with a lower degree of differentiation and shorter survival rate. The aim of this study is to fully investigate, for the first time, the role of the mitochondrial form of APE1 in HCC.Methods: As a study model, we analyzed samples from a cohort of patients diagnosed with HCC who underwent surgical resection. Mitochondrial APE1 content, expression levels of the mitochondrial import protein Mia40, and mtDNA damage of tumor tissue and distal non-tumor liver of each patient were analyzed. In parallel, we generated a stable HeLa clone for inducible silencing of endogenous APE1 and re-expression of the recombinant shRNA resistant mitochondrially targeted APE1 form (MTS-APE1). We evaluated mtDNA damage, cell growth, and mitochondrial respiration.Results: APE1's cytoplasmic positivity in Grades 1 and 2 HCC patients showed a significantly higher expression of mitochondrial APE1, which accounted for lower levels of mtDNA damage observed in the tumor tissue with respect to the distal area. In the contrast, the cytoplasmic positivity in Grade 3 was not associated with APE1's mitochondrial accumulation even when accounting for the higher number of mtDNA lesions measured. Loss of APE1 expression negatively affected mitochondrial respiration, cell viability, and proliferation as well as levels of mtDNA damage. Remarkably, the phenotype was efficiently rescued in MTS-APE1 clone, where APE1 is present only within the mitochondrial matrix.Conclusions: Our study confirms the prominent role of the mitochondrial form of APE1 in the early stages of HCC development and the relevance of the non-nuclear fraction of APE1 in the disease progression. We have also confirmed overexpression of Mia40 and the role of the MIA pathway in the APE1 import process. Based on our data, inhibition of the APE1 transport by blocking the MIA pathway could represent a new therapeutic approach for reducing mitochondrial metabolism by preventing the efficient repair of mtDNA. [ABSTRACT FROM AUTHOR]

Background: Nuclear factor of activated T cells 2 (NFAT2) has been reported to regulate the development and malignancy of few tumors. In this study, we aimed to explore the effect of NFAT2 expression on cell fate of HepG2 cell and its potential mechanisms.Methods: Firstly, the pcDNA3.1-NFAT2 plasmid was transfected into HepG2 cells to construct NFAT2 overexpressed HepG2 cells. Then, the chemical count kit-8 cell viability assay, Annexin V-FITC apoptosis detection, EdU labeling proliferation detection, transwell and wound healing experiments were performed. The expression of Egr2 and FasL, and the phosphorylation of AKT and ERK, after ionomycin and PMA co-stimulation, was detected, while the Ca2+ mobilization stimulated by K+ solution was determined. At last, the mRNA and protein expression of NFAT2, Egr2, FasL, COX-2 and c-myc in carcinoma and adjacent tissues was investigated.Results: The NFAT2 overexpression suppressed the cell viability, invasion and migration capabilities, and promoted apoptosis of HepG2 cells. NFAT2 overexpression induced the expression of Egr2 and FasL and suppressed the phosphorylation of AKT and ERK. The sensitivity and Ca2+ mobilization of HepG2 cells was also inhibited by NFAT2 overexpression. Compared with adjacent tissues, the carcinoma tissues expressed less NFAT2, Egr2, FasL and more COX-2 and c-myc.Conclusion: The current study firstly suggested that NFAT2 suppressed the aggression and malignancy of HepG2 cells through inducing the expression of Egr2. The absence of NFAT2 and Egr2 in carcinoma tissues reminded us that NFAT2 may be a promising therapeutic target for hepatocellular carcinoma treatment. [ABSTRACT FROM AUTHOR]

Background: Previous studies have shown a major green tea polyphenol (-)-epigallocatechin-3-gallate ((-)-EGCG) as a powerful anti-cancer agent. However, its poor bioavailability and requirement of a high dosage to manifest activity have restricted its clinical application. Recently, our team synthesized a peracetate-protected derivative of EGCG, which can act as a prodrug of (-)-EGCG (ProEGCG) with enhanced stability and improved bioavailability in vitro and in vivo. Herein, we tested the therapeutic efficacy of this novel ProEGCG, in comparison to EGCG, toward human endometrial cancer (EC).Methods: In this study, the effects of ProEGCG and EGCG treatments on cell growth, cell survival and modulation of intracellular signaling pathways in RL95-2 and AN3 CA EC cells were compared. The antiproliferative effect was evaluated by cell viability assay. Apoptosis was measured by annexin/propidium iodide staining. Expression of mitogen-activated protein kinases, markers of proliferation and apoptosis were measured by immunoblot analysis. In addition, the effects of ProEGCG and EGCG on tumor growth, vessel formation and gene expression profiles on xenograft models of the EC cells were investigated.Results: We found that treatment with ProEGCG, but not EGCG, inhibited, in a time- and dose-dependent manner, the proliferation and increased apoptosis of EC cells. Treatment with low-dose ProEGCG significantly enhanced phosphorylation of JNK and p38 MAPK and inhibited phosphorylation of Akt and ERK which are critical mediators of apoptosis. ProEGCG, but not EGCG, elicited a significant decrease in the growth of the EC xenografts, promoted apoptotic activity of tumour cells in the EC xenografts, and decreased microvessel formation, by differentially suppressing anti-apoptotic molecules, NOD1 and NAIP. Notably, no obvious adverse effects were detected.Conclusions: Taken together, ProEGCG at a low dose exhibited anticancer activity in EC cells through its anti-proliferative, pro-apoptotic and anti-tumor actions on endometrial cancer in vitro and in vivo. In contrast, a low dose of EGCG did not bring about similar effects. Importantly, our data demonstrated the efficacy and safety of ProEGCG which manifests the potential of a novel anticancer agent for the management of endometrial cancer. [ABSTRACT FROM AUTHOR]

Background: The metzincin family of metalloproteinases and the tissue inhibitors of metalloproteinases (TIMPs) are essential proteins required for biological processes during cancer progression. This study aimed to determine the role of TIMP-2 in ovarian cancer progression and chemoresistance by reducing TIMP-2 expression in vitro in Fallopian tube secretory epithelial (FT282) and ovarian cancer (JHOS2 and OVCAR4) cell lines.Methods: FT282, JHOS2 and OVCAR4 cells were transiently transfected with either single or pooled TIMP-2 siRNAs. The expression of different genes after TIMP-2 knock down (T2-KD) or in response to chemotherapy was determined at the mRNA level by quantitative real time PCR (qRT-PCR) and at the protein level by immunofluorescence. Sensitivity of the cell lines in response to chemotherapy after TIMP-2 knock down was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-Ethynyl-2'-deoxyuridine (EdU) assays. Cell invasion in response to TIMP-2 knockdown was determined by xCELLigence.Results: Sixty to 90 % knock down of TIMP-2 expression was confirmed in FT282, OVCAR4 and JHOS2 cell lines at the mRNA and protein levels. TIMP-2 knock down did not change the mRNA expression of TIMP-1 or TIMP-3. However, a significant downregulation of MMP-2 in T2-KD cells occurred at both the protein and activation levels, compared to Control (Cont; scrambled siRNA) and Parental cells (P, transfection reagent only). In contrast, membrane bound MT1-MMP protein levels were significantly upregulated in T2-KD compared to Cont and P cells. T2-KD cells exhibited enhanced proliferation and increased sensitivity to cisplatin and paclitaxel treatments. Enhanced invasion was observed in the T2-KD-JOSH2 and OVCAR4 cells but not in T2-KD-FT282 cells. Treatment with cisplatin or paclitaxel significantly elevated the expression of TIMP-2 in Cont cells but not in T2-KD cells, consistent with significantly elevated expression of chemoresistance and CSC markers and activation of STAT3. Furthermore, a potent inhibitor of STAT3 activation, Momelotinib, suppressed chemotherapy-induced activation of P-STAT3 in OVCAR4 cells with concomitant reductions in the expression of chemoresistance genes and CSC markers.Conclusions: The above results suggest that TIMP-2 may have a novel role in ovarian cancer proliferation, invasion and chemoresistance. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: The prognosis of lung cancer was found to be associated with a series of biomarkers related to the tumor immune microenvironment (TIME), which can modulate the biological behaviors and consequent outcomes of lung cancer. Therefore, establishing a prognostic model based on the TIME for lung cancer patients, especially young patients with lung adenocarcinoma (LUAD), is urgently needed.Methods: In all, 809 lung cancer patients from the TCGA database and 71 young patients with LUAD in our center were involved in this study. Univariate and multivariate analysis based on clinical characteristics and TIME-related expression patterns (as evaluated by IHC) were performed to estimate prognosis and were verified by prognostic nomograms.Results: Both LUAD and lung cancer patients with high CD28 expression had shorter disease-free survival (DFS) (P = 0.0011; P = 0.0001) but longer overall survival (OS) (P = 0.0001; P = 0.0282). TIME-related molecules combined with clinical information and genomic signatures could predict the prognosis of young patients with LUAD with robust efficiency and could be verified by the established nomogram based on the Cox regression model. In addition, CD28 expression was correlated with an abundance of lymphocytes and could modulate the TIME. Higher CD28 levels were observed in primary tumors than in metastatic tissues.Conclusion: TIME-related molecules were identified as compelling biomarkers for predicting the prognosis of lung cancer, especially in a cohort of young patients. Furthermore, CD28, which is associated with poor DFS but long OS, might participate in the modulation of the TIME and has a different role in the prognosis of young patients with LUAD. [ABSTRACT FROM AUTHOR]

Background: Genomic instability is a hallmark of cancer. The G1 checkpoint allows cells to repair damaged DNA that may lead to genomic instability. The high-risk human papillomavirus (HPV) E7 gene can abrogate the G1 checkpoint, yet the mechanism is still not fully understood. Our recent study showed that WDHD1 (WD repeat and high mobility group [HMG]-box DNA-binding protein 1) plays a role in regulating G1 checkpoint of E7 expressing cells. In this study, we explored the mechanism by which WDHD1 regulates G1 checkpoint in HPV E7 expressing cells.Methods: NIKS and RPE1 derived cell lines were used. Real-time PCR, Rescue experiment, FACS and BrdU labeling experiments were performed to examine role of GCN5 in G1 checkpoint abrogation in HPV-16 E7 expressing cells.Results: In this study, we observed that WDHD1 facilitates G1 checkpoint abrogation by modulating GCN5 in HPV E7 expressing cells. Notably, depletion of WDHD1 caused G1 arrest while overexpression of GCN5 rescued the inhibitory effects of WDHD1 knockdown on G1/S progression. Furthermore, siWDHD1 significantly decreased cell cycle proliferation and DNA synthesis that was correlated with Akt phosphorylation (p-Akt), which was reversed by GCN5 overexpression in HPV E7 expressing cells.Conclusions: In summary, our data identified a WDHD1/GCN5/Akt pathway leading to the abrogation of G1 checkpoint in the presence of damaged DNA, which may cause genomic instability and eventually HPV induced tumorigenesis. [ABSTRACT FROM AUTHOR]

Background: Astrocytoma is a common tumor type in primary central nervous system and has a high death rate around the world. Aberrant expression of long non-coding RNAs (lncRNAs) has been introduced by emerging studies to result in the development of diverse cancers.Methods: RT-qPCR examined the expression of SNHG17, miR-876-5p and ERLIN2, and western blot evaluated ERLIN2 protein level. RNA pull down and luciferase reporter assays illustrated the relationships between SNHG17 and its downstream molecules.Results: SNHG17 was up-regulated in astrocytoma cells. Moreover, SNHG17 silence could repress the proliferation, migration and invasion of astrocytoma cells. Besides, miR-876-5p was selected out as a downstream molecule of SNHG17 in astrocytoma. ERLIN2 was determined to be targeted by miR-876-5p. ERLIN2 mRNA and protein levels were lessened by miR-876-5p overexpression and SNHG17 silence. Additionally, miR-876-5p overexpression decelerated the biological processes of astrocytoma cells, so did ERLIN2 knockdown. More importantly, the impacts of SNHG17 down-regulation on the malignant behaviors of astrocytoma cells were counteracted by overexpressed ERLIN2 or inhibited miR-876-5p.Conclusions: SNHG17 could induce the progression of astrocytoma by sponging miR-876-5p to elevate the expression of ERLIN2. This study indicated that SNHG17 has a high potential to be a therapeutic target for astrocytoma. [ABSTRACT FROM AUTHOR]

Background: Breast cancer (BC) is a malignant tumor that occurs in the epithelial tissue of the breast gland. Long non-coding RNA (lncRNA) small nucleolar RNA host gene 3 (SNHG3) has been found to promote BC cell proliferation and invasion by regulating the microRNA (miR)-101/zinc-finger enhancer binding axis in BC. Herein, the objective of the present study is to evaluate the effect of lncRNA SNHG3 on BC cell proliferation and metastasis with the Notch signaling pathway.Methods: Differentially expressed lncRNA in BC tissues and normal breast tissues was analyzed. SNHG3 si-RNA-1 and SNHG3 si-RNA-2 were constructed to detect the mechanism of SNHG3 interference in BC cell proliferation, viability, migration and invasion. Then, dual-luciferase reporter gene assay was utilized to verify the binding relation between SNHG3 and miR-154-3p as well as miR-154-3p and Notch2. Moreover, xenograft transplantation was applied to confirm the in vitro experiments.Results: Highly expressed SNHG3 was observed in BC tissues. The growth of BC cells in vivo and in vitro was evidently repressed after silencing SNHG3. BC cell invasion and migration were inhibited by silencing SNHG3 in vitro. SNHG3 could act as a competing endogenous RNA of miR-154-3p and upregulate the Notch signaling pathway to promote BC cell development. Activation of the Notch signaling pathway can partly reverse the inhibition of cell activity induced by silencing SNHG3.Conclusion: Our study demonstrated that interfered lncRNA SNHG3 promoted BC cell proliferation and metastasis by activating the Notch signaling pathway. This investigation may offer new insight for BC treatment. [ABSTRACT FROM AUTHOR]

Background: Interaction between microenvironment and breast cancer cells often is not considered at the early stages of drug development leading to failure of many drugs at later clinical stages. Etanercept is a TNF-alpha inhibitor that has been investigated for potential antitumor effect in breast cancer with conflicting results.Methods: Secretome data on MDA-MB-231 cancer cell-line were from public repositories and subjected to gene enrichment analyses. Since MDA-MB-231 cells secrete high levels of Granulocyte-Monocyte Colony Stimulating Factor, which activates macrophages to promote tumor growth, the effect of macrophage co-culturing on anticancer efficacy of Etanercept in breast cancer was evaluated using the Boolean network modeling and in vitro experiments including invasion, cell cycle, Annexin PI, and tetrazolium based viability assays and NFKB activity.Results: The secretome profile of MDA-MB-231 cells was similar to the expression of genes following treatment of breast cancer cells with TNF-α. Accordingly, inhibition of TNF-α by Etanercept decreased MDA-MB-231 cell survival, induced apoptosis and cell cycle arrest in vitro and inhibited NFKB activation. The inhibitory effect of Etanercept on cell viability, cell cycle progression, invasion and induction of apoptosis decreased following co-culturing of the cancer cells with macrophages. The Boolean network modeling of the changes in the dynamics of intracellular signaling pathways revealed NFKB activation by secretome of macrophages, leading to a decreased efficacy of Etanercept, suggesting NFKB inhibition as an alternative approach to inhibit cancer cell growth in the presence of macrophage crosstalk.Conclusion: This study indicates that the effect of Etanercept may be influenced by residing macrophages in tumor microenvironment, and suggests a method to predict the effect of drugs in the presence of stromal cells to guide experimental designs in drug development. [ABSTRACT FROM AUTHOR]

Background: Clinical trials have been conducted to clarify the beneficial effects of VD3 (1α,25-dihydroxy vitamin D3, also known as calcitriol) treatment in prostate cancer. However, the molecular mechanisms underlying these effects are not fully understood. Recent studies on IGFBP-3 have indicated its intracellular functions in cell growth and apoptosis. The aim of this study was to confirm the benefits of low-dose VD3 treatment and clarify the molecular mechanisms underlying these beneficial effects in prostate cancer cells.Methods: The molecular effects of simultaneous treatment of LNCaP cells and their genetically modified cell lines with low concentration of docetaxel and VD3 were biologically and biochemically analyzed. To further determine the effects of VD3 treatment on IGFBP-3 induction system, cells were temporarily treated with VD3 in combination with a transcriptional inhibitor or protein synthesis inhibitor. Bcl-2 protein and its mRNA behavior were also observed in Igfbp-3 expression-modified LNCaP cells to determine the involvement of IGFBP-3 in the suppression of Bcl-2 by VD3 treatment.Results: Changes in IGFBP-3 expression levels in LNCaP cells indicated that it mediated the inhibition of cell growth induced by VD3 treatment. IGFBP-3 was also found to be a mediator of the enhanced cytotoxicity of prostate cancer cells to VD3 in combination with the anti-cancer drug. We further identified the distinct property of the IGFBP-3 induction system, wherein temporal VD3 stimulation-induced prolonged IGFBP-3 expression and VD3 treatment-induced increase in IGFBP-3 expression were optimized based on the protein concentration rather than the mRNA concentration. Meanwhile, Bcl-2 expression was down-regulated by VD3 treatment in an IGFBP-3-independent manner.Conclusion: These findings indicate the molecular mechanisms of IGFBP-3 induction stimulated by VD3 and IGFBP-3 independent Bcl-2 suppression by VD3 treatment in prostate cancer cells. The results could prompt a re-evaluation of VD3 usage in therapy for patients with prostate cancer. [ABSTRACT FROM AUTHOR]

Background: Capacitive-resistive electric transfer (CRET) is a non-invasive therapeutic strategy that applies radiofrequency electric currents within the 400-600 kHz range to tissue repair and regeneration. Previous studies by our group have shown that 48 h of intermittent exposure to a 570 kHz CRET signal at a subthermal density of 50 μA/mm2 causes significant changes in the expression and activation of cell cycle control proteins, leading to cycle arrest in human cancer cell cultures. The present study investigates the relevance of the signal frequency in the response of the human neuroblastoma cell line NB69 to subthermal electric treatment with four different signal frequency currents within the 350-650 kHz range.Methods: Trypan blue assay, flow cytometry, immunofluorescence and immunoblot were used to study the effects of subthermal CRET currents on cell viability, cell cycle progression and the expression of several marker proteins involved in NB69 cell death and proliferation.Results: The results reveal that among the frequencies tested, only a 448 kHz signal elicited both proapoptotic and antiproliferative, statistically significant responses. The apoptotic effect would be due, at least in part, to significant changes induced by the 448 kHz signal in the expression of p53, Bax and caspase-3. The cytostatic response was preceded by alterations in the kinetics of the cell cycle and in the expression of proteins p-ERK1/2, cyclin D1 and p27, which is consistent with a potential involvement of the EGF receptor in electrically induced changes in the ERK1/2 pathway. This receives additional support from results indicating that the proapototic and antiproliferative responses to CRET can be transiently blocked when the electric stimulus is applied in the presence of PD98059, a chemical inhibitor of the ERK1/2 pathway.Conclusion: The understanding of the mechanisms underlying the ability of slowing down cancer cell growth through electrically-induced changes in the expression of proteins involved in the control of cell proliferation and apoptosis might afford new insights in the field of oncology. [ABSTRACT FROM AUTHOR]

Background: Atypical teratoid/rhabdoid tumors (AT/RTs) are highly malignant brain tumors with inactivation of the SMARCB1 gene, which play a critical role in genomic transcriptional control. In this study, we analyzed the genomic and transcriptomic profiles of human AT/RTs to discover new druggable targets.Methods: Multiplanar sequencing analyses, including whole exome sequencing (WES), single nucleotide polymorphism (SNP) arrays, array comparative genomic hybridization (aCGH), and whole transcriptome sequencing (RNA-Seq), were performed on 4 AT/RT tissues. Validation of a druggable target was conducted using AT/RT cell lines.Results: WES revealed that the AT/RT genome is extremely stable except for the inactivation of SMARCB1. However, we identified 897 significantly upregulated genes and 523 significantly downregulated genes identified using RNA-Seq, indicating that the transcriptional profiles of the AT/RT tissues changed substantially. Gene set enrichment assays revealed genes related to the canonical pathways of cancers, and nucleophosmin (NPM1) was the most significantly upregulated gene in the AT/RT samples. An NPM1 inhibitor (NSC348884) effectively suppressed the viability of 7 AT/RT cell lines. Network analyses showed that genes associated with NPM1 are mainly involved in cell cycle regulation. Upon treatment with an NPM1 inhibitor, cell cycle arrest at G1 phase was observed in AT/RT cells.Conclusions: We propose that NPM1 is a novel therapeutic target for AT/RTs. [ABSTRACT FROM AUTHOR]

Background: Dysregulation of microRNA (miRNA) expression is associated with hallmarks of aggressive tumor phenotypes, e.g., enhanced cell growth, proliferation, invasion, and anchorage independent growth in prostate cancer (PCa).Methods: Serum-based miRNA profiling involved 15 men diagnosed with non-metastatic (stage I, III) and metastatic (stage IV) PCa and five age-matched disease-free men using miRNA arrays with select targets confirmed by quantitative real-time PCR (qRT-PCR). The effect of miR-186-5p inhibition or ectopic expression on cellular behavior of PCa cells (i.e., PC-3, MDA-PCa-2b, and LNCaP) involved the use bromodeoxyuridine (BrdU) incorporation, invasion, and colony formation assays. Assessment of the impact of miR-186-5p inhibition or overexpression on selected targets entailed microarray analysis, qRT-PCR, and/or western blots. Statistical evaluation used the modified t-test and ANOVA analysis.Results: MiR-186-5p was upregulated in serum from PCa patients and metastatic PCa cell lines (i.e., PC-3, MDA-PCa-2b, LNCaP) compared to serum from disease-free individuals or a normal prostate epithelial cell line (RWPE1), respectively. Inhibition of miR-186-5p reduced cell proliferation, invasion, and anchorage-independent growth of PC-3 and/or MDA-PCa-2b PCa cells. AKAP12, a tumor suppressor target of miR-186-5p, was upregulated in PC-3 and MDA-PCa-2b cells transfected with a miR-186-5p inhibitor. Conversely, ectopic miR-186-5p expression in HEK 293 T cells decreased AKAP12 expression by 30%. Both pAKT and β-catenin levels were down-regulated in miR-186-5p inhibited PCa cells.Conclusions: Our findings suggest miR-186-5p plays an oncogenic role in PCa. Inhibition of miR-186-5p reduced PCa cell proliferation and invasion as well as increased AKAP12 expression. Future studies should explore whether miR-186-5p may serve as a candidate prognostic indicator and a therapeutic target for the treatment of aggressive prostate cancer. [ABSTRACT FROM AUTHOR]

Background: Smurf2 E3 ubiquitin ligase physically associates with and regulate the stability of distinct cellular protein substrates. The multi-functional scaffold protein Connector enhancer of kinase suppressor of ras 2 (CNKSR2) plays a key role in regulating cell proliferation, and differentiation through multiple receptor tyrosine kinase pathways. The aim of this study was to investigate whether the interaction between Smurf2 and CNKSR2 has any significant role in the post transcriptional regulation of CNKSR2 expression in breast cancer.Methods: Here we demonstrate a novel interaction of CNKSR2 with Smurf2 by co-immunoprecipitation, indirect immunofluorescence studies, and surface plasmon resonance (SPR) analysis, which can ubiquitinate, but stabilize CNKSR2 by protecting it from proteasome mediated degradation.Results: CNKSR2 protein levels were significantly increased upon forced overexpression of Smurf2, indicating the role of Smurf2 in regulating the stability of CNKSR2. Conversely, Smurf2 knockdown resulted in a marked decrease in the protein level expression of CNKSR2 by facilitating enhanced polyubiquitination and proteasomal degradation and reduced the proliferation and clonogenic survival of MDA-MB-231 breast cancer cell lines. Tissue microarray data from 84 patients with various stages of mammary carcinoma, including (in order of increasing malignant potential) normal, usual hyperplasia, fibrocystic changes, fibroadenoma, carcinoma-in-situ, and invasive ductal carcinoma showed a statistically significant association between Smurf2 and CNKSR2 expression, which is also well correlated with the ER, PR, and HER2 status of the tissue samples. A comparatively high expression of Smurf2 and CNKSR2 was observed when the expression of ER and PR was low, and HER2 was high. Consistently, both Smurf2 and CNKSR2 showed an integrated expression in MCF10 breast progression model cell lines.Conclusions: Altogether, our findings reveal that Smurf2 is a novel positive regulator of CNKSR2 and suggest that Smurf2-CNKSR2 interaction may serve as a common strategy to control proliferation of human breast cancer cells by modulating CNKSR2 protein stability. [ABSTRACT FROM AUTHOR]

Background: Neuroendocrine cells (NECs) reside adjacent to colonic stem cells (SCs) in the crypt stem cell (SC) niche, but how NECs are involved in regulation of SCs is unclear. We investigated NECs expressing somatostatin (SST) and somatostatin receptor type 1 (SSTR1) because SST inhibits intestinal proliferation.Hypothesis: SSTR1 cells maintain SCs in a quiescent state, and aberrant SST signaling contributes to SC overpopulation in colorectal cancer (CRC).Methods: The proportion of SCs to NECs cells was quantified, by flow cytometry, in CRC cell lines and primary normal/tumor tissues based on cellular ALDH and SSTR1 levels, respectively. Doubling time and sphere-formation was used to evaluate cell proliferation and stemness. CRC cell lines were treated with exogenous SST and SST inhibitor cyclosomatostatin (cycloSST) and analyzed for changes in SCs and growth rate. Paracrine signaling between NECs and SCs was ascertained using transwell cultures of ALDH+ and SSTR1+ cells.Results: In CRC cell lines, the proportion of ALDH+ cells inversely correlates with proportion of SSTR1+ cells and with rate of proliferation and sphere-formation. While primary normal tissue shows SST and SSTR1 expression, CRC shows only SSTR1 expression. Moreover, ALDH+ cells did not show SST or SSTR1 expression. Exogenous SST suppressed proliferation but not ALDH+ population size or viability. Inhibition of SSTR1 signaling, via cycloSST treatment, decreased cell proliferation, ALDH+ cell population size and sphere-formation. When co-cultured with SSTR1+ cells, sphere-formation and cell proliferation of ALDH+ cells was inhibited.Conclusion: That each CRC cell line has a unique ALDH+/SSTR1+ ratio which correlates with its growth dynamics, suggests feedback mechanisms exist between SCs and NECs that contribute to regulation of SCs. The growth suppression by both SST and cycloSST treatments suggests that SST signaling modulates this feedback mechanism. The ability of SSTR1+ cells to decrease sphere formation and proliferation of ALDH+ cells in transwell cultures indicates that the ALDH subpopulation is regulated by SSTR1 via a paracrine mechanism. Since ALDH+ cells lack SST and SSTR1 expression, we conjecture that SST signaling controls the rate of NEC maturation as SCs mature along the NEC lineage, which contributes to quiescence of SCs and inhibition of proliferation. [ABSTRACT FROM AUTHOR]

Background: Human primary myeloma (MM) cells do not survive in culture; current in vitro and in vivo systems for growing these cells are limited to coculture with a specific bone marrow (BM) cell type or growth in an immunodeficient animal model. The purpose of the study is to establish an interactive healthy donor whole BM based culture system capable of maintaining prolonged survival of primary MM cells. This normal BM (NBM) coculture system is different from using autologous BM that is already affected by the disease.Methods: Whole BM from healthy donors was cultured in medium supplemented with BM serum from MM patients for 7 days, followed by 7 days of coculture with CD138-selected primary MM cells or MM cell lines. MM cells in the coculture were quantified using flow cytometry or bioluminescence of luciferase-expressing MM cells. T-cell cytokine array and proteomics were performed to identify secreted factors.Results: NBM is composed of adherent and nonadherent compartments containing typical hematopoietic and mesenchymal cells. MM cells, or a subset of MM cells, from all examined cases survived and grew in this system, regardless of the MM cells' molecular risk or subtype, and growth was comparable to coculture with individual stromal cell types. Adherent and nonadherent compartments supported MM growth, and this support required patient serum for optimal growth. Increased levels of MM growth factors IL-6 and IL-10 along with MM clinical markers B2M and LDHA were detected in supernatants from the NBM coculture than from the BM cultured alone. Levels of extracellular matrix factors (e.g., MMP1, HMCN1, COL3A1, ACAN) and immunomodulatory factors (e.g., IFI16, LILRB4, PTPN6, AZGP1) were changed in the coculture system. The NBM system protected MM cells from dexamethasone but not bortezomib, and effects of lenalidomide varied.Conclusions: The NBM system demonstrates the ability of primary MM plasma cells to interact with and to survive in coculture with healthy adult BM. This model is suitable for studying MM-microenvironment interactions, particularly at the early stage of engagement in new BM niches, and for characterizing MM cell subpopulations capable of long-term survival through secretion of extracellular matrix and immune-related factors. [ABSTRACT FROM AUTHOR]

Background: Osteosarcoma is a typical bone cancer that primarily affects adolescents. The therapeutic activity of drugs is limited by their severe drug-related toxicities, therefore, a therapeutic approach which is less toxic and highly effective in tumor is of utmost importance.Method: In this study, ifosfamide-loaded poly (lactic-co-glycolic acid) (PLGA)-dextran polymeric nanoparticles (PD/IFS) was developed and studied its anticancer efficacy against multiple osteosarcoma cancer cells. The drug-loaded nanoparticle was characterized for physical and biological characterizations.Results: The formulated PD/IFS showed a high drug loading capacity and displayed a pH-sensitive release pattern, with a sustained release profile of the IFS. PD/IFS nanoparticles exhibited remarkable in vitro anticancer activity comparable to that of free IFS solution in a concentration dependent manner in MG63 and Saos-2 cancer cells. PLGA-dextran by itself did not affect cell viability of cancer cells indicating its excellent biocompatibility. The formulation exhibited significantly higher PARP and caspase-3/7 expression in both the cancer cells.Conclusion: Our study successfully demonstrated that nanoparticulate encapsulation of antitumor agent will increase the therapeutic efficacy and exhibit a greater induction of apoptosis and cell death. [ABSTRACT FROM AUTHOR]

Background: Nutrition is believed to be a primary contributor in regulating gene expression by affecting epigenetic pathways such as DNA methylation and histone modification. Resveratrol and pterostilbene are phytoalexins produced by plants as part of their defense system. These two bioactive compounds when used alone have been shown to alter genetic and epigenetic profiles of tumor cells, but the concentrations employed in various studies often far exceed physiologically achievable doses. Triple-negative breast cancer (TNBC) is an often fatal condition that may be prevented or treated through novel dietary-based approaches.Methods: HCC1806 and MDA-MB-157 breast cancer cells were used as TNBC cell lines in this study. MCF10A cells were used as control breast epithelial cells to determine the safety of this dietary regimen. CompuSyn software was used to determine the combination index (CI) for drug combinations.Results: Combinatorial resveratrol and pterostilbene administered at close to physiologically relevant doses resulted in synergistic (CI <1) growth inhibition of TNBCs. SIRT1, a type III histone deacetylase (HDAC), was down-regulated in response to this combinatorial treatment. We further explored the effects of this novel combinatorial approach on DNA damage response by monitoring γ-H2AX and telomerase expression. With combination of these two compounds there was a significant decrease in these two proteins which might further resulted in significant growth inhibition, apoptosis and cell cycle arrest in HCC1806 and MDA-MB-157 breast cancer cells, while there was no significant effect on cellular viability, colony forming potential, morphology or apoptosis in control MCF10A breast epithelial cells. SIRT1 knockdown reproduced the effects of combinatorial resveratrol and pterostilbene-induced SIRT1 down-regulation through inhibition of both telomerase activity and γ-H2AX expression in HCC1806 breast cancer cells. As a part of the repair mechanisms and role of SIRT1 in recruiting DNMTs, the effects of this combination treatment was also explored on DNA methyltransferases (DNMTs) expression. Interestingly, the compounds resulted in a significant down-regulation of DNMT enzymes with no significant effects on DNMT enzyme expression in MCF10A control cells.Conclusion: Collectively, these results provide new insights into the epigenetic mechanisms of a novel combinatorial nutrient control strategy that exhibits synergy and may contribute to future recalcitrant TNBC prevention and/or therapy. [ABSTRACT FROM AUTHOR]

Background: Notch signalling regulates cell fate in most tissues, promoting precursor cell proliferation in some, but differentiation in others. Accordingly, downregulation or overactivity variously contributes to cancer development. So far, little is known about Notch pathway activity and function in the normal urothelium and in urothelial carcinoma (UC). We have therefore investigated expression of Notch pathway components in UC tissues and cell lines and studied the function of one receptor, NOTCH1, in detail.Methods: Expression of canonical Notch pathway components were studied in UC and normal bladder tissues by immunohistochemistry and quantitative RT-PCR and in UC cell lines and normal cultured urothelial cells by qRT-PCR, immunocytochemistry and Western blotting. Pathway activity was measured by reporter gene assays. Its influence on cell proliferation was investigated by γ-secretase inhibition. Effects of NOTCH1 restoration were followed by measuring cell cycle distribution, proliferation, clonogenicity and nuclear morphology.Results: NOTCH1 and its ligand, DLL1, were expressed at plasma membranes and in the cytoplasm of cells in the upper normal urothelium layer, but became downregulated in UC tissues, especially in high-stage tumours. In addition, the proteins were often delocalized intracellularly. According differences were observed in UC cell lines compared to normal urothelial cells. Canonical Notch pathway activity in reporter assays was repressed in UC cell lines compared to normal cells and a mammary carcinoma cell line, but was induced by transfected NOTCH1. Inhibitors of Notch signalling acting at the γ-secretase step did not affect UC cell proliferation at concentrations efficacious against a cell line with known Notch activity. Surprisingly, overexpression of NOTCH1 into UC cell lines did not significantly affect short-term cell proliferation, but induced nuclear abnormalities and diminished clonogenicity.Conclusion: Our data indicate that canonical Notch signalling is suppressed in urothelial carcinoma mainly through downregulation of NOTCH1. These findings can be explained by proposing that canonical Notch signalling may promote differentiation in the urothelium, like in many squamous epithelia, and its suppression may therefore be advantageous for tumour progression. As an important corollary, inhibition of canonical Notch signalling is unlikely to be efficacious and might be counter-productive in the treatment of urothelial carcinoma. [ABSTRACT FROM AUTHOR]

Background: There is a large body of evidence which suggests that bile acids increase the risk of colon cancer and act as tumor promoters, however, the mechanism(s) of bile acids mediated tumorigenesis is not clear. Previously we showed that deoxycholic acid (DCA), a tumorogenic bile acid, and ursodeoxycholic acid (UDCA), a putative chemopreventive agent, exhibited distinct biological effects, yet appeared to act on some of the same signaling molecules. The present study was carried out to determine whether there is overlap in signaling pathways activated by tumorogenic bile acid DCA and chemopreventive bile acid UDCA.Methods: To determine whether there was an overlap in activation of signaling pathways by DCA and UDCA, we mutagenized HCT116 cells and then isolated cell lines resistant to UDCA induced growth arrest. These lines were then tested for their response to DCA induced apoptosis.Results: We found that a majority of the cell lines resistant to UDCA-induced growth arrest were also resistant to DCA-induced apoptosis, implying an overlap in DCA and UDCA mediated signaling. Moreover, the cell lines which were the most resistant to DCA-induced apoptosis also exhibited a greater capacity for anchorage independent growth.Conclusion: We conclude that UDCA and DCA have overlapping signaling activities and that disregulation of these pathways can lead to a more advanced neoplastic phenotype. [ABSTRACT FROM AUTHOR]