Agar Colony Research Articles

In vitro therapy against glioblastoma cells by 3-Dezaneplanocin-A, panobinostat, and temozolomide

Background: Glioblastoma multiforme (GBM) is the most malignant primary brain tumor. Current treatment against this tumor consists of maximal surgical resection without threatening the patient's life, followed by a treatment with temozolomide, with or without combined radiotherapy. GBM is resistant to the conventional antitumor therapies, so in this research, we tried to inhibit tumor growth with the combination of three drugs: (1) panobinostat, an inhibitor of histone deacetylases, (2) 3-Dezaneplanocin-A (DZNep), an inhibitor of EZH2, a protein which belongs to the polycomb repressor complex 2, acting as a histone methylase, and (3) temozolomide, an alkylating agent. Methods: The T98G GBM commercial cell line was used. Cells were exposed to single treatments of the drugs and to the three possible combinations among them. Soon after, two-dimensional (2D) and 3D clonogenic assays were assessed for in vitro tumorigenicity testing. Real-time quantitative polymerase chain reaction of 2 proapoptotic genes (BAX and NOXA) and 2 antiapoptotic genes (BCL2 and BCL-XL) was also assessed. Results: The panobinostat and temozolomide combination produced a positive effect against T98G glioblastoma cells by reducing soft agar colony formation, by inducing high expression levels of NOXA, and by reducing BCL-XL expression. Equally, the panobinostat and DZNep combination produced a positive effect against T98G glioblastoma cells by reducing colony formation in adherent conditions and by inducing high expression levels of BAX. Finally, temozolomide alone was the most efficient drug for decreasing BCL2 expression. Conclusion: Panobinostat and temozolomide combination or panobinostat and DZNep combination might be more efficient against glioblastoma cells than just temozolomide.

Chronic Microcystin-LR Exposure Induces Hepatocarcinogenesis via Increased Gankyrin in Vitro and in Vivo

Background/Aims: Our recent study indicated that the serum microcystin-LR (MC-LR) level is positively linked to the risk of human hepatocellular carcinoma (HCC). Gankyrin is over-expressed in cancers and mediates oncogenesis; however, whether MC-LR induces tumor formation and the role of gankyrin in this process is unclear. Methods: We induced malignant transformation of L02 liver cells via 35 passages with exposure to 1, 10, or 100 nM MC-LR. Wound healing, plate and soft agar colony counts, and nude mice tumor formation were used to evaluate the tumorigenic phenotype of MC-LR-treated cells. Silencing gankyrin was used to confirm its function. We established a 35-week MC-LR exposure rat model by twice weekly intraperitoneal injection with 10 μg/kg body weight. In addition, 96 HCC patients were tested for tumor tissue gankyrin expression and serum MC-LR levels. Results: Chronic low-dose MC-LR exposure increased proliferation, mobility, clone and tumor formation abilities of L02 cells as a result of gankyrin activation, while silencing gankyrin inhibited the carcinogenic phenotype of MC-LR-treated cells. MC-LR also induced neoplastic liver lesions in Sprague-Dawley rats due to up-regulated gankyrin. Furthermore, a trend of increased gankyrin was observed in humans exposed to MC-LR. Conclusion: These results suggest that MC-LR induces hepatocarcinogenesis in vitro and in vivo by increasing gankyrin levels, providing new insight into MC-LR carcinogenicity studies.

ONZIN Upregulation by Mutant p53 Contributes to Osteosarcoma Metastasis Through the CXCL5-MAPK Signaling Pathway

Background/Aims: Gain-of-function of mutant p53 is associated with a high rate of lung metastasis in osteosarcoma. To investigate the mechanism of mutant p53-induced osteosarcoma metastasis, expression array analysis was performed, comparing non-metastatic osteosarcomas from p53+/- mice with metastatic osteosarcomas from p53R172H/+ mice. Onzin (Plac8) was identified as one of the genes upregulated in p53R172H/+ mouse metastatic osteosarcomas. Accordingly, we investigated the role of ONZIN in human osteosarcoma metastasis. Methods: ONZIN function and its downstream targets were examined in osteosarcoma cell lines. Assays related to tumorigenesis and metastasis, including cell migration, invasion, clonogenic survival, and soft agar colony formation, were performed in osteosarcoma cells. Additionally, mouse xenograft models were used to examine the role of ONZIN overpression in tumorigenesis in vivo. Lastly, 87 osteosarcoma patients were recruited to investigate the clinical relevance of ONZIN overexpression in metastasis and prognosis. Results: ONZIN overexpression enhanced osteosarcoma cell proliferation, clonogenic survival, migration, and invasion independent of p53 status. Furthermore, ONZIN overexpression induced CXCL5 upregulation and resulted in increased ERK phosphorylation, which contributed to more aggressive osteosarcoma metastatic phenotypes. More importantly, overexpression of ONZIN in human osteosarcoma patients was closely associated with lung metastasis, poor prognoses, and survival. Conclusions: Overexpression of ONZIN promotes osteosarcoma progression and metastasis, and can serve as a clinical biomarker for osteosarcoma metastasis and prognosis.

PON2 Exemplifies a Unique Dependency of B Cell Lineage ALL Cells on Detoxifying Lactonases

Background and significance: Paraoxonase 2 (PON2) is a member of mammalian detoxifying enzymes that are located to the mitochondrial membrane, hydrolyze lactone metabolites and interact with coenzyme Q10 to diminish oxidative stress. While PON2 is highly expressed in the CNS and multiple fetal tissues, expression levels in normal hematopoietic cells are low. We began to study the function of PON2 in B cell lineage ALL, because microarray analyses suggested high mRNA levels of PON2 in B cell lineage ALL cells. In addition, PON2 is used as a diagnostic marker on a 15 gene diagnostic LDA panel (e.g. in AALL1131; NCT02883049) that is used for the identification of Ph-like ALL, a subgroup with particularly poor outcome and specific treatment requirements.Results: Analyzing data from pediatric and adult clinical trials, we found that greater than median PON2 mRNA levels at the time of diagnosis predicted poor clinical outcomes for both children (COG P9906; n=207; P=1.09e-05) and adults (ECOG; n=215; P=0.003) with B-lineage ALL. Studying expression levels of PON2 by quantitative RT-PCR and Western blot in normal bone marrow B cell precursors from healthy donors and patient-derived pre-B ALL cells including Ph+ and Ph -like ALL, we found 3-10-fold increased mRNA and protein levels of PON2 throughout multiple pre-B ALL samples. To elucidate potential functions of PON2 in normal B cells and B-lineage ALL, we studied normal B cell development and ALL-models in Pon2-/- mice. While B cell development was unperturbed in Pon2 -deficient mice, deletion of Pon2 had profound effects on both BCR-ABL1- and N RASG12D-driven leukemogenesis. Compared to wildtype, Pon2-/- pre-B ALL cells failed to form colonies in semisolid agar. Pon2-/-ALL cells were arrested in G0/G1 phase and expressed 2-5-fold increased levels of Arf and p21, compared to Pon2+/+ ALL cells. Strikingly, >50% of Pon2-/-ALL cells spontaneously underwent cellular senescence, as shown by b-galactosidase staining in conjunction with increased Arf expression levels. These in vitro findings suggest an important role of PON2 in B-lymphoid leukemogenesis, which was confirmed in transplant experiments based on BCR-ABL1 and N RASG12D ALL models. While Pon2 -deficiency substantially prolonged survival of recipient mice of BCR-ABL1 ALL cells (P=0.0001), mice transplanted with Pon2 -deficient N RASG12D ALL cells survived for indefinite periods of time.Targeting PON2 expression in relapse ALL: Given that PON2 is expressed at very high levels in relapse ALL samples, we tested the concept of targeting PON2 lactonase activity in a prodrug-approach. While PON2 activity typically results in detoxification of lactone-metabolites, lactone-hydrolysis of the N-(3-oxododecanoyl)-homoserine lactone (3OC12) prodrug results in cytotoxic byproducts (Guoping et al., 2016). We therefore tested the therapeutic potential of 3OC12. For genetic validation, we treated wildtype and Pon2-/- ALL cells with 3OC12 and found strong cytotoxic effects in wildtype but not Pon2-/- ALL cells. Likewise, inducible overexpression of Pon2 in patient-derived pre-B ALL cells exacerbated toxicity of 3OC12 compared to empty vector controls. Likewise, CRISPR-Cas9 mediated ablation of PON2 in human ALL PDX reversed sensitivity of the pre-B ALL cells to 3OC12.Conclusion: Here we describe the previously unknown function of the detoxifying PON2 lactonase as an essential prerequisite for pre-B cell transformation and leukemogenesis. PON2 expression is specific for leukemia cells, an outcome predictor for patients with pre-B ALL and a biomarker of Ph-like ALL. While PON2 protects ALL cells and enables malignant growth, we demonstrate that its lactonase-activity can be leveraged for pharmacological targeting as exemplified by the lactone-prodrug 3OC12. DisclosuresNo relevant conflicts of interest to declare.

Role of Glypican-3 in the growth, migration and invasion of primary hepatocytes isolated from patients with hepatocellular carcinoma.

Recently, Glypican-3 (GPC3) has been identified as a potential hepatocellular carcinoma (HCC) diagnostic and/or therapeutic target. GPC3 has been found to be up-regulated in HCC and to be absent in normal and cirrhotic liver. As yet, however, the molecular characteristics of GPC3 and its role in HCC cell physiology and development are still undefined. Human hepatocyte cultures were established from 10 HCC patients. Additional liver samples were obtained from 5 patients without cirrhosis and/or HCC. Soft agar colony formation, (co-)immunofluorescence and Western blot assays were used to characterize the hapatocyte cultures. The expression of GPC3 in the hepatocytes was silenced using siRNA, after which, apoptosis, scratch wound migration and transwell invasion assays were performed. We found that in HCC precursor hepatocytes GPC3 is increasingly expressed in different forms and at different locations, i.e., a non-cleaved form (70kDa) was found to be localized in the cytoplasm while a N-terminal cleaved form (N-GPC3: 40kDa) was fond to be localized in the cytoplasm and at the extracellular side of hepatocyte membranes. In addition, we found that the non-cleaved form of GPC3 co-localizes with Furin-Convertase in the Golgi apparatus. We also found that, similar to GPC3, Furin-Convertase is expressed in HCC precursor cells, suggesting a role in GPC3 processing. Subsequent siRNA-mediated GPC3 silencing resulted in a temporary inhibition of cell proliferation, migration and ivasion, while inducing apoptosis in transformed hepatocytes. Our data reveal new aspects of the role of GPC3 in early hepatocyte transformation. In addition we conclude that GPC3 may serve as a new HCC immune-therapeutic target.

Identificação por espectrometria de massa MALDI-TOF de Salmonella spp. e Escherichia coli isolados de carcaças bovinas

RESUMO: O objetivo deste trabalho foi introduzir a técnica de espectrometria de massa com fonte de ionização e dessorção a laser assistida por matriz e analisador de tempo-de-voo (MALDI-TOF) para incrementar o método tradicional microbiológico na detecção de Salmonella spp. e Escherichia coli em carcaças bovinas. Foram avaliadas 270 amostras de 90 carcaças de bovinos. Para isolamento de Salmonella spp. e E. coli, foram utilizadas, respectivamente, as metodologias descritas na ISO 6579:2002 e no Compendium of Methods for the Microbiological Examination of Foods. As análises por MALDI-TOF foram realizadas a partir de isolados cultivados em ágar nutriente ou em caldo triptona de soja, provenientes das amostras com características bioquímicas positivas (n=7), inconclusivas (n=4) e negativas (n=85) para Salmonella spp. e bioquímicas positivas (n=37) e negativas (n=85) para E. coli. Os perfis de massas foram adquiridos com o espectrômetro de massas MALDI-TOF Autoflex III SmartBeam e os espectros brutos foram processados usando o programa MALDI Biotyper (Bruker Daltonics). De acordo com a identificação preliminar, com base na morfologia das colônias e nas reações bioquímicas, sete isolados foram considerados positivos para Salmonella spp. Através do MALDI Biotyper, esses sete isolados foram classificados como pertencentes ao gênero Salmonella e, além disso, identificados como S. enterica. Quatro isolados que apresentaram características fenotípicas não usuais e resultados inconclusivos nos testes bioquímicos para Salmonella foram identificados como pertencentes aos gêneros Citrobacter e Proteus após análise por MALDI. Para E. coli, 37 amostras foram positivas pelos testes bioquímicos da espécie, o que foi confirmado por MALDI Biotyper. A metodologia MALDI-TOF permitiu a rápida confirmação da identidade de Salmonella spp. e E. coli, podendo ser utilizada para detecção desses microrganismos em isolados bacterianos de carcaças bovinas.

Flavonoids inhibit chronically exposed arsenic-induced proliferation and malignant transformation of HaCaT cells.

Apart from exposure to UV-radiation, studies show relationship between skin cancer and chronic ingestion of arsenic through drinking water. Chemopreventive strategies could help in reducing the toxic effects of arsenic and arsenic-induced skin cancer. Cytotoxicity of arsenic on human skin keratinocytes HaCaT cells was evaluated using MTT and trypan blue assays. Arsenic-induced malignant transformant HaCaT cells were selected through soft agar colony assay. Cell cycle progression was analyzed through FACS. The expressions of genes modulated by arsenic were studied through RT-PCR. The lower concentrations (0.1-0.5μmol/L) of arsenic were non-toxic and transformed HaCaT cells on chronic exposure, and also enhanced the cell proliferation. Silibinin and fisetin reduced the arsenic-induced cell proliferation and malignant transformation. A slight increase in G2-M phase cell population was also observed. The anti-proliferation effects of flavonoids on HaCaT transformants were further enhanced when combined with gamma radiation. Chronic and acute exposure to arsenic modulated the expression of transformation-associated genes including Bcl-2A1, IGFL-1, Rab31, and TNC in HaCaT cells. Chronic exposure to lower arsenic concentrations caused malignant transformation of skin keratinocytes and that effect was attenuated by flavonoids silibinin and fisetin. Thus, chemoprevention could reduce arsenic-caused detrimental effects on skin cells.

TLR4 promotes the expression of HIF-1α by triggering reactive oxygen species in cervical cancer cells invitro-implications for therapeutic intervention.

The present study investigated the mechanism underlying Toll-like receptor 4 (TLR4)-mediated stimulation of hypoxia-inducible factor-1α (HIF-1α) activity and its association with reactive oxygen species (ROS) in cervical cancer cells. SiHa cells were cultured and randomized to control, lipopolysaccharide (LPS), methyl-β-cyclodextrin (MβCD)+LPS, ammonium pyrrolidinedithiocarbamate (PDTC)+LPS, ST2825+LPS and small interfering (si) RNA TLR4+LPS treatment groups. Cell proliferation was quantified using an MTT assay, cell cloning was performed using soft agar colony formation and HIF-1α expression was detected by immunocytochemical staining and western blot analyses. Dichloro-dihydro-fluorescein diacetate and lucigenin luminescence assays were used to detect alterations in ROS and nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase content, respectively. Co-localization of TLR4 and HIF-1α was detected by immunofluorescence staining and observed using fluorescence microscopy. Compared with the control group, cell proliferation was enhanced in the LPS-treated group and was not altered in the PDTC+LPS treatment group. Cell proliferation was reduced in all other treatment groups (P<0.05). Compared with the LPS group, cell proliferation decreased in all other groups. Compared with the PDTC+LPS treatment group, cell proliferation significantly decreased when LPS was co-administered with ST2825, siTLR4 and MβCD (P<0.01). Treatment with MβCD+LPS exhibited an increased inhibitory effect on cell activity and proliferation. Compared with the control group, HIF-1α expression was enhanced following treatment with LPS, although it decreased when LPS was co-administered with ST2825, siTLR4 and MβCD (P<0.05). HIF-1α expression decreased following treatment with ST2825, siTLR4, MβCD and PDTC+LPS, compared with treatment with LPS alone. Compared with the PDTC+LPS group, HIF-1α activity decreased when LPS was co-administered with ST2825, siTLR4 and MβCD. NADPH oxidase and ROS levels increased in cells treated with LPS, compared with the control group, at 24 and 12 h following treatment, respectively, and decreased at 12 h when LPS was co-administered with ST2825, siTLR4 and MβCD. There was no difference between the LPS and PDTC+LPS groups with respect to NADPH and ROS levels. Compared with the PDTC+LPS group, NADPH oxidase activity and ROS content decreased when LPS was co-administered with ST2825, siTLR4 and MβCD. NADPH oxidase activity and ROS content were lowest in the MβCD+LPS treatment group, and immunofluorescent staining demonstrated that TLR4 was localized to the cell surface and HIF-1α was primarily localized to the cytoplasm. TLR4 was co-expressed with HIF-1α in cervical cancer cells. The results of the present study suggested that TLR4 signaling primarily promoted HIF-1α activity via activation of lipid rafts/NADPH oxidase redox signaling and may be associated with the initiation and progression of cervical cancer. This promoting effect was stronger in TLR4/lipid rafts/NADPH oxidase pathway than that in TLR4-NF-κB signaling pathway. Therefore, the TLR4/lipid raft-associated redox signal may be a target for therapeutic intervention to prevent the growth of cervical cancer.

Hdac7 promotes lung tumorigenesis by inhibiting Stat3 activation

BackgroundLung cancer is the leading cause of cancer death worldwide. However, the molecular mechanisms underlying lung cancer development have not been fully understood. The functions of histone deacetylases (HDACs), a class of total eighteen proteins (HDAC1–11 and SIRT1–7 in mammals) that deacetylate histones and non-histone proteins, in cancers are largely unknown.MethodsHdac7+/−/K-Ras mice and HDAC7-depleted human lung cancer cell lines were used as models for studying the function of Hdac7 gene in lung cancer. Kaplan-Meier survival analysis was performed to explore the relationship between HDAC7 expression and prognosis of human lung cancers. Recombinant lentivirus-mediated in vivo gene expression or knockdown, Western blotting, and pull-down assay were applied to investigate the underlying molecular mechanism by which Hdac7 promotes lung tumorigenesis.ResultsThe number and burden of lung tumor were dramatically reduced in Hdac7+/−/K-Ras mice compared to control K-Ras mice. Also, in Hdac7+/−/K-Ras mice, cell proliferation was significantly inhibited and apoptosis in lung tumors was greatly enhanced. Similarly, cell proliferation and anchorage-independent growth of human lung cancer cell lines expressing shHDAC7 were also significantly suppressed and apoptosis was dramatically elevated respectively. Mechanistic study revealed that Hdac7 mutation in mouse lung tumors or HDAC7 depletion in human tumor cell lines resulted in significantly enhanced acetylation and tyrosine-phosphorylation of Stat3 and HDAC7 protein directly interacted with and deacetylateed STAT3. The Hdac7 mutant-mediated inhibitory effects on lung tumorigenesis in mice and cell proliferation/soft agar colony formation of human lung cancer cell lines were respectively reversed by expressing dnStat3. Finally, the high HDAC7 mRNA level was found to be correlated with poor prognosis of human lung cancer patients.ConclusionOur study suggests that Hdac7 promotes lung tumorigenesis by inhibiting Stat3 activation via deacetylating Stat3 and may shed a light on the design of new therapeutic strategies for human lung cancer.

15 - Redox modulatory and Anti-cancer property of Toluquinol, a marine fungus derived natural product

Several natural bioproducts from the marine environment have been developed successfully into potent drugs for treating various diseases including cancer. “Drugs from the Sea” is an emerging field in drug discovery area. Toluquinol, a methylhydroquinone compound, produced by marine fungus Penicillium sp. is a known AKT inhibitor. The present study investigates the anticancer and antioxidant property of toluquinol in human lung cancer cell lines. Studies carried out in cell free systems by ABTS, DPPH free radical scavenging and total antioxidant status demonstrated significant free radical scavenging property by toluquinol in a dose dependent manner. Toluquinol was also seen to increase GSH levels and decrease catalase enzyme activity in H2O2 treated human lung cancer cell lines (H520 and H23). Soft agar colony formation assay and scratch wound assay was performed to investigate toluquinol’s anticancer property. EtBr/PI staining and apoptotic gene mRNA expression clearly shows apoptosis induced by toluquinol in these cancer cell lines. Normal human lung cells, L132 were used as controls. We also screened differential genomic responses of lung cancer cell lines to toluquinol using Affymetrix Expression Arrays. The data shows that toluquinol treatment modulates the expression of genes related to cell proliferation/DNA repair, antioxidant and inflammatory-immune pathways. This study for the first time demonstrates anticancer and antioxidant property of toluquinol in human lung cancer cell lines.

GATA3 frameshift mutation promotes tumor growth in human luminal breast cancer cells and induces transcriptional changes seen in primary GATA3 mutant breast cancers.

The GATA3 transcription factor is one of the most frequently mutated genes in breast cancer. Heterozygous mutations, mostly frameshifts, are seen in 15% of estrogen receptor positive breast cancers, the subtype in which these mutations are almost exclusively found. Mouse studies have shown that Gata3 is critical for breast development and that GATA3 gene dosage affects breast tumor progression. Human patient data have shown that high Gata3 expression, a feature of luminal subtype breast cancers, is associated with a better prognosis. Although the frequency of GATA3 mutation suggests an important role in breast cancer development or progression, there is little understanding of how mutations in GATA3 affect its function in luminal breast epithelial cells and what gene expression changes result as a consequence of the mutations. Here, using gene editing, we have created two sets of isogenic human luminal breast cancer cell lines with and without a hotspot truncating GATA3 mutation. GATA3 mutation enhanced tumor growth in vivo but did not affect sensitivity to clinically used hormonal therapies or chemotherapeutic agents. We identified genes with upregulated and downregulated expression in GATA3 mutant cells, a subset of which was concordantly differentially expressed in GATA3 mutant primary luminal breast cancers. Addback of mutant GATA3 recapitulated mutation-specific gene expression changes and enhanced soft agar colony formation, suggesting a gain of function for the mutant protein.

Aberrant DNA methylation in radon and/or cigarette smoke-induced malignant transformation in BEAS-2B human lung cell line

ABSTRACT It is well known that cigarette smoking (CS) and/or radon (Rn) induce malignant transformation in lung cells. To investigate the mechanisms underlying lung carcinogenesis induced by CS, Rn; or Rn followed by CS using BEAS-2B cell line derived from human bronchial epithelial cells. BEAS-2B cells were exposed to either Rn (20,000 Bq/m3) for 30 min or CS (20%) for 10 min or Rn followed by CS for 40 min. Global and gene-specific DNA methylation modifications were measured by microarray and methylation-specific polymerase chain reaction. Cell cycle and apoptosis were determined by flow cytometry, while soft agar colony formation was conducted to assess the characteristics of malignant transformation. Data demonstrated global hypomethylation as well as gene-specific DNA methylation alterations in all treatment groups compared to unexposed control cells. In addition, Rn and CS produced DNA hypermethylation of protein tyrosine phosphatase receptor type M and ectodysplasin A2 receptor, two genes related to malignant transformation. In all treatment conditions, cell proliferation and survival of malignant cells was increased, while apoptosis was initially first passage elevated but decreased at passages 5–15. Our results indicate that aberrant DNA methylation plays an important role in Rn- and/or CS-induced malignant transformation. In addition, BEAS-2B cell line may be used as an in vitro model to investigate mechanisms underlying malignant transformation induced by ambient environmental contaminants.

Elevated expression of ΔNp63 in advanced esophageal squamous cell carcinoma.

This study aims to explore the expression level of ΔNp63 in esophageal squamous cell carcinoma (ESCC). To investigate the association between ΔNp63 (p40) expression and ESCC biology, we compared the levels of ΔNp63 expression in normal and tumor tissues, with a specific focus on the diagnostic value of ΔNp63 in ESCC. We analyzed 160 consecutive patients with ESCC who underwent surgical resection without neoadjuvant chemotherapy at Gunma University Hospital (Maebashi, Japan) between September 2000 and January 2010. The clinicopathological characteristics and survival of patients were subclassified based on the expression of ΔNp63 as determined by immunohistochemistry, indicating that ΔNp63 was highly expressed in 75.6% (121/160) of ESCC patients. Clinicopathological analysis of ΔNp63 expression showed that ΔNp63‐positive tumors significantly correlated with two important clinical parameters: T factor (P = 0.0316) and venous invasion (P = 0.0195). The 5‐year overall survival rates of advanced ESCC patients with positive and negative expression of ΔNp63 were 35.6% and 71.7%, respectively. Multivariate analysis revealed that the expression of ΔNp63 was identified as an independent prognostic factor (P = 0.0049) in advanced ESCC. In line with this, ΔNp63α‐transduced ESCC cell lines increased tumor growth in a soft agar colony formation assay. We report here for the first time that ΔNp63 expression increases the oncogenic potential of ESCC and is an independent marker for predicting poor outcome in advanced ESCC. Our findings suggest that ΔNp63 could serve as a new diagnostic marker for ESCC and might be a relevant therapeutic target for the treatment of patients with this disease.

Involvement of Bmi-1 gene in the development of gastrointestinal stromal tumor by regulating p16Ink4A/p14ARF gene expressions: An in vivo and in vitro study

ObjectiveThis study was conducted in order to explore the role that Bmi-1 plays during the development of a gastrointestinal stromal tumor (GIST) by regulation of the p16Ink4A and p14ARF expressions. MethodsEighty-six patients diagnosed with GIST were selected to take part in this experiment. The Bmi-1 protein expressions in GIST and adjacent normal tissues were detected using immunohistochemistry and further analyzed by using photodensitometry. To monitor and track the progression of the GIST, a 3-year follow-up was conducted for all affected patients. After cell transfection, the GIST cells were assigned into the control group (without transfection), the negative control (NC) group (transfected with Bmi-1-Scramble plasmid), and the Bmi-1 shRNA group (transfected with the pcDNA3.1-Bmi-1 shRNA plasmid). Protein and mRNA expressions collected from Bmi-1, p16lnk4A, P14ARF, cyclin D1, and CDK4 were measured using both the RT-qPCR and western blotting methods Cell senescence was assessed and obtained by using the β-Galactosidase (β-Gal) activity assay. The use of a Soft agar colony formation assay and CCK-8 assay were performed in order to detect the cell growth and subsequent proliferation. Cell invasion and migration were analyzed using the Transwell assay and scratch test. ResultsBmi-1 in the GIST tissues was found to be significantly higher and the p16lnk4A and P14ARF expressions were lower than those in the adjacent normal tissues. Bmi-1 was negatively correlated with p16lnk4A and P14ARF expressions according to the correlation analysis. Bmi-1 expression was associated with the TNM stage, postoperative recurrence, metastasis, tumor size, and the 5-year survival rate. Area under ROC curve was calculated at 0.884, and sensitivity, specificity, and accuracy of Bmi-1 predicting the GIST were 67.44%, 97.67%, and 65.12%, respectively. Patients exhibiting a high Bmi-1 expression in the GIST tissues had lower survival rates than those with low Bmi-1 expression. In comparison with the control group, P14ARF, and p16lnk4A were up-regulated, while cyclinD 1 and CDK4 were down-regulated, cell senescence was promoted, and cell proliferation, invasion, and migration also showed some regression in the Bmi-1 shRNA group. ConclusionsThese collection of data indicated that the down-regulated Bmi-1 might inhibit the proliferation, invasion, and migration of GIST cells and can be subsequently linked to the incidence and developing a prognosis of GIST.

Isolation of Probiotic Piliated Lactobacillus rhamnosus Strains from Human Fecal Microbiota Using SpaA Antiserum-Based Colony Immunoblotting.

Piliated Lactobacillus rhamnosus (pLR) strains possess higher adherent capacity than non-piliated strains. The objective of this study was to isolate and characterize probiotic pLR strains in human fecal samples. To this end, mouse polyclonal antiserum (anti-SpaA) against the recombinant pilus protein (SpaA) of L. rhamnosus strain GG (LGG) was prepared and tested for its reactivity and specificity. With the anti-SpaA, a method combining the de Man, Rogosa, and Sharpe (MRS) agar plating separation and colony immunoblotting (CIB) was developed to isolate pLR from 124 human fecal samples. The genetic and phenotypic characteristics of the resultant pLR isolates were compared by randomly amplified polymorphic DNA (RAPD) fingerprinting, and examination of adhesion to Caco-2 cells, hydrophobicity, autoaggregation, and in vitro gastrointestinal tolerance. Anti-SpaA specifically reacted with three pLR strains of 25 test strains, as assessed by western blotting, immunofluorescence flow cytometry, and immunoelectron microscopy (IEM) assays. The optimized MRS agar separation plus anti-SpaA-based CIB procedure could quantitatively detect 2.5 × 103 CFU/ml of pLR colonies spiked in 106 CFU/ml of background bacteria. Eight pLR strains were identified in 124 human fecal samples, and were confirmed by 16S RNA gene sequencing and IEM identification. RAPD fingerprinting of the pLR strains revealed seven different patterns, of which only two isolates from infants showed the same RAPD profiles with LGG. Strain PLR06 was obtained with high adhesion and autoaggregation activities, hydrophobicity, and gastrointestinal tolerance. Anti-SpaA-based CIB is a rapid and inexpensive method for the preliminary screening of novel adherent L. rhamnosus strains for commercial purposes.

Karyopherin α-2 is a reliable marker for identification of patients with high-risk stage II colorectal cancer.

Adjuvant chemotherapy (AC) is frequently considered in patients with high-risk stage II colorectal cancer (CRC). Among patients with stage II CRC who do not receive AC because they are not considered to be at high risk, 20-25% will develop recurrence and die from the disease. Elevated levels of KPNA2 have been observed in various cancers, and overexpression of KPNA2 is related to CRC progression. We examined the expression of KPNA2 using 293 CRC tissues, including 118 with stage II CRC, and investigated the applicability of KPNA2 as a biomarker to predict high-risk stage II CRC. Moreover, we further investigated the role of KPNA2 as an oncogene in CRC carcinogenesis using in vitro functional studies. High KPNA2 expression was associated with vascular (p=0.027) and lymphatic invasion (p=0.009) in patients with stage II CRC. On multivariate analysis, high KPNA2 expression (HR 3.174, 95% CI 2.060-4.889; p<0.001) was independently associated with survival in patients with CRC. The overall survival rate in patients with high KPNA2 expression was higher than that in patients with low KPNA2 expression in CRC (p<0.001), even in patients with stage II CRC (p=0.001). Additionally, KPNA2 was associated with tumorigenesis and cancer progression in CRC cells; high KPNA2 expression was associated with increased cell proliferation (p<0.05), migration (p=0.03), invasion (p=0.001), and semisolid agar colony formation (p<0.001). KPNA2 expression is useful for identification of patients with high-risk stage II CRC who could benefit from AC and that KPNA2 may also be a promising therapeutic target.

RET Signaling in Prostate Cancer.

Purpose: Large diameter perineural prostate cancer is associated with poor outcomes. GDNF, with its coreceptor GFRα1, binds RET and activates downstream pro-oncogenic signaling. Because both GDNF and GFRα1 are secreted by nerves, we examined the role of RET signaling in prostate cancer.Experimental Design: Expression of RET, GDNF, and/or GFRα1 was assessed. The impact of RET signaling on proliferation, invasion and soft agar colony formation, perineural invasion, and growth in vivo was determined. Cellular signaling downstream of RET was examined by Western blotting.Results: RET is expressed in all prostate cancer cell lines. GFRα1 is only expressed in 22Rv1 cells, which is the only line that responds to exogenous GDNF. In contrast, all cell lines respond to GDNF plus GFRα1. Conditioned medium from dorsal root ganglia contains secreted GFRα1 and promotes transformation-related phenotypes, which can be blocked by anti-GFRα1 antibody. Perineural invasion in the dorsal root ganglion assay is inhibited by anti-GFRα antibody and RET knockdown. In vivo, knockdown of RET inhibits tumor growth. RET signaling activates ERK or AKT signaling depending on context, but phosphorylation of p70S6 kinase is markedly increased in all cases. Knockdown of p70S6 kinase markedly decreases RET induced transformed phenotypes. Finally, RET is expressed in 18% of adenocarcinomas and all three small-cell carcinomas examined.Conclusions: RET promotes transformation associated phenotypes, including perineural invasion in prostate cancer via activation of p70S6 kinase. GFRα1, which is secreted by nerves, is a limiting factor for RET signaling, creating a perineural niche where RET signaling can occur. Clin Cancer Res; 23(16); 4885-96. ©2017 AACR.

MicroRNA-130a is an oncomir suppressing the expression of CRMP4 in gastric cancer.

Gastric cancer is one of the most common causes of death worldwide, although its incidence has steadily declined in recent years. There is strong evidence that aberrantly expressed microRNAs (miRNAs) are involved in gastric cancer tumorigenesis. Furthermore, CRMP4 is closely associated with the occurrence and development of gastric cancer, and our predictions suggest that miR-130a, which can promote gastric cancer tumorigenesis, is a potential CRMP4 regulator. In this study, we investigated the expression of CRMP4 and miR-130a in human gastric cancer cell lines by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot (WB) examination and direct interactions between miR-130a and CRMP4 by dual-luciferase reporter assay. We also evaluated the biological roles of miR-130a and CRMP4 in gastric cancer cells by flow cytometry, MTT assay, soft agar colony formation assay, and Transwell tests and confirmed CRMP4 function in vivo, using a tumor xenograft model. Our results demonstrated that CRMP4 expression was significantly decreased at both the gene and protein levels, while miR-130a expression was notably increased, in five human gastric cancer cell lines compared with human gastric epithelial cells. Dual-luciferase reporter assays indicated that CRMP4 was the direct target of miR-130a. Moreover, an inverse regulatory relationship between miR-130a and CRMP4 was verified by qRT-PCR and WB, and overexpression of miR-130a in BGC823 cells enhanced apoptosis and cell proliferation, arrested the cell cycle in G0/G1, and facilitated cell colony formation, invasion, migration, and adhesion, while upregulation of CRMP4 had opposite effects. Finally, the growth and weight of transplanted tumors derived from BGC823 cells in which CRMP4 was knocked down were remarkably reduced. These data indicate that miR-130a is an oncomir targeting CRMP4 and could be developed as a potential prognostic factor and a novel therapeutic target in gastric cancer.

Exostosin 1 regulates cancer cell stemness in doxorubicin-resistant breast cancer cells.

Cancer stem cells (CSCs) are associated with cancer recurrence following radio/chemotherapy owing to their high resistance to therapeutic intervention. In this study, we investigated the role of exostoxin 1 (EXT1), an endoplasmic reticulum (ER)-residing type II transmembrane glycoprotein, in cancer cell stemness. DNA microarray analysis revealed that doxorubicin-resistant MCF7/ADR cells have high levels of EXT1 expression compared to its parental cell line, MCF7. These cells showed significantly higher populations of CSCs and larger populations of aldehyde dehydrogenase (ALDH+) and CD44+/CD24-cells, as compared to MCF7 cells. siRNA-mediated knockdown of EXT1 in MCF7/ADR cells significantly reduced cancer stem cell markers, populations of ALDH+and CD44+/CD24- cells, mRNA and protein expression for CD44, and mammosphere number. Furthermore, epithelial mesenchymal transition (EMT) markers and migratory behavior were also repressed with reduced EXT1. In an in vitro soft agar colony formation assay, EXT1 knockdown by short hairpin RNA (shRNA) reduced the colony formation ability of these cells. Based on these results, we suggest that EXT1 could be a promising novel target to overcome cancer cell stemness in anthracycline-based therapeutic resistance.

Elevated TIMP-1 expression is associated with a prometastatic phenotype, disease relapse, and poor survival in neuroblastoma.

Approximately two-thirds of patients with neuroblastoma are found to have metastatic disease at time of diagnosis with frequent skeletal, lymph node, central nervous system, and liver involvement. Using a serial in vivo splenic injection model, we have isolated an aggressive subclone (BE(2)-C/LM2) from MYCN-amplified neuroblastomas that demonstrate an enhanced propensity to develop metastatic liver lesions. BE(2)-C/LM2 subclone cells demonstrate increased adherent, soft agar colony and tumorsphere growth in vitro. Components of the tumor microenvironment regulate cancer progression, via networks of cytokines and growth factors. Cytokine array analysis identified increased TIMP-1 in the plasma of mice injected with BE(2)-C/LM2 subclone cells, leading us to hypothesize that TIMP-1 may play a role in our observed prometastatic phenotype. Immunoblotting and ELISA demonstrated enhanced endogenous TIMP-1 expression in our isolated neuroblastoma subclone. Silencing endogenous TIMP-1 successfully blocked in vitro proliferation, soft agar colony formation and tumorsphere formation by BE(2)-C/LM2 cells. Stable RNA interference of endogenous TIMP-1 failed to reverse the prometastatic phenotype of our BE(2)-C/LM2 subclone in our liver metastasis model, suggesting that endogenous TIMP-1 levels may not be an essential component of this in vivo behavior. Notably, tissue microarray analysis and Kaplan-Meier by gene expression demonstrates that elevated TIMP-1 expression is correlated with increased disease relapse and mortality in patients with neuroblastoma. Taken together, our study identifies TIMP-1 as a novel soluble factor that is associated with a prometastatic phenotype in our in vivo model and adverse outcomes in patients with neuroblastoma.