bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract B46: Celecoxib induces autophagy and apoptosis in human colorectal cancer cells: Strategies to enhance cell death
Authors: Huang Shengbing , Sinicrope Frank A. 
Published: May 2012

Abstract
Purpose: Celecoxib has been shown to induce cell death in conjunction with its chemopreventive effects. However, the mechanisms by which celecoxib induces cell death are incompletely understood. We determined whether celecoxib can induce autophagy, a process of cell destruction whereby cytoplasmic proteins and organelles are sequestered in vacuoles and delivered to lysosomes for degradation and recycling. Both apoptosis and autophagy have been shown to be negatively regulated by pro-survival Bcl-2 proteins, and the small molecule Bcl-2/Bcl-xL antagonist (ABT-737), can enhance both processes. Since autophagy can be pro-survival or pro-death depending upon the cellular context, we determined whether autophagy inhibition can drive colon cancer cells into apoptosis.
Methods: HCT116 (wild-type and Bax−/−), HT29, SW480 colorectal cancer cell lines were treated with celecoxib (0–120 µM) and/or ABT-737 (Abbott; 0–5 µM) in the presence or absence of a pan caspase inhibitor, z-VAD-fmk. Cell viability was determined using the MTS assay and apoptosis was analyzed by Annexin V FITC labeling. Immunoblotting was used to analyze caspase cleavage and LC3 conversion. GFP-LC3B cellular localization was determined by confocol microscopy. Autophagic flux was determined by LC3 immunoblotting in the presence of the lysosome inhibitor, bafilomycin A1. Knockdown of Bcl-xL, Vps34 or Atg8/LC3B were achieved by lentiviral shRNA or siRNA.
Results: Celecoxib was shown to induce apoptosis that was attenuated by ectopic Bcl-2 or Bax knockout. ABT-737 synergistically enhanced celecoxib-induced apoptosis as shown by caspase cleavage and Annexin V labeling. Celecoxib also induced autophagy, as shown by conversion of the autophagosome-associated protein light chain 3 (LC3) from a cytosolic (LC3I) to a membrane-bound (LC3II) form as shown by immunoblotting, and a punctate fluorescence pattern of ectopic GFP-LC3 protein. Celecoxib-induced conversion of LC3 that was due to autophagy induction, as shown using the lysosome inhibitor, Bafilomycin A1 that produced an accumulation of LC3II. Furthermore, ABT-737 enhanced LC3 conversion by celecoxib. Autophagy inhibition was achieved using 3-methyladenine (3-MA), wortmannin or knockdown of Vps34 or Atg8/LC3B using siRNA. Inhibition of autophagy enhanced apoptosis as shown by caspase cleavage and Bid truncation in cells treated with celecoxib plus ABT-737. Furthermore, the addition of 3-MA to celecoxib plus ABT-737 produced a 5-fold increase in apoptosis that was associated with caspase cleavage and cytochrome c release.
Conclusions: Celecoxib induces both apoptosis and autophagy that can both be potentiated by ABT-737. Inhibition of autophagy was shown to potently drive cells into apoptosis, suggesting a novel therapeutic strategy against colon cancer cells.
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B46.
Abstract B52: MicroRNAs and SEL1L gene regulation in human pancreatic ductal adenocarcinoma
Authors: Liu Qian , Chen Jinyun , Amos Chris , Killary Ann , Sen Subrata , Frazier Marsha 
Published: May 2012

Abstract
Pancreas-specific tumor suppressor gene SEL1L is downregulated at both the mRNA and protein levels in a significant proportion of human pancreatic ductal adenocarcinoma (PDAC) cases. We sought to use statistical methods to determine if one or more aberrantly upregulated microRNAs (miRNA) are responsible for the repression of SEL1L, which would help elucidate the role of specific miRNAs in PDAC.
Based on published microRNAs microarray data and miRNA targets prediction resource, we initially identified seven miRNAs for our study which were reported to be upregulated in PDAC and potentially target SEL1L. Using real-time PCR, we quantitatively assessed the expression levels of SEL1L mRNA and these miRNAs in 42 pairs of PDAC samples and matched normal adjacent tissues. Fisher's Exact Test and Kruskal-Wallis Test were applied to evaluate the correlation between SEL1L and the miRNAs.
Our results showed that the expression of SEL1L mRNA inversely correlates with the expression of 3 miRNAs (P &lt; 0.0001, P &lt; 0.0001 and P = 0.002, respectively). As the number of these overexpressed miRNAs increase from 0 to 3, we observed progressively increasing downregulation of SEL1L (P − trend = 0.001).
Our findings suggest that the 3 miRNAs work cooperatively to repress SEL1L mRNA expression. These specific miRNAs may serve as useful biomarkers for PDAC.
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B52.
Abstract B56: Regulation of immune-related genes by integrin signaling affects the cancer cell proliferation and invasion
Authors: Park Michael Y. , Lee Hee Doo , Jeon Ok-Hee , Kim Doo-Sik 
Published: May 2012

Abstract
Cytokines have been implicated in tumor proliferation and metastasis. Saxatillin, snake venom-derived disintegrin, is known to suppress tumor progression in vivo and in vitro but its correlation with cytokine's functions has not been known yet. We have investigated the role of immune-related genes in cancer cell proliferation and metastasis in human ovarian cancer cell (MDAH 2774). We demonstrate that saxatilin, an integrin antagonist, mitigated MDAH 2774 proliferation and invasion by reducing the level of TNF- induced matrix metalloproteinase-9 (MMP-9) and IL-8 expression in a dose-dependent manner. And Immunoblot assay of nuclear extracts of the cancer cells implicated that signal transducer and activator of transcription (STAT) is related in integrin signaling pathway. We also observed the activity of human glioma cell-invasion mediated by IL-8, as examined by a Boyden chamber assay, involved the mechanism of enhancing the actin stress fiber formation. IL-8 increased the phosphorylation of focal adhesion kinase (FAK), known to be the site of integrin clustering and nuclear translocation of STAT. We have shown here that interleukin-8 promotes the cancer proliferation and that mRNA levels of immune-related genes are regulated by disintegrin in human ovarian cancer cell line. These results demonstrate immune-related genes as a mediator of metastasis and proliferation and disintegrin would contribute in slowing of cancer development by regulating integrin signaling. (This work was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea Government (No.2009-0081759), KIST grant, and the Brain Korea 21 (BK21) program.)
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B56.
Abstract B58: Gene expression study on a highly aggressive canine transmissible venereal tumor of a NOD/SCID mice model
Authors: Chu Reamin , Lei Hang-Rong , Lin Cheng-Se , Lin Cheng-Se , Lee Chien-Yueh , Yeh Lih-Seng , Chang Shih-Chieh 
Published: May 2012

Abstract
We have set up a xenograft NOD/SCID mice model bearing canine transmissible venereal tumor (CTVT) (designated as MCTVT). In addition to the similarity of the tumor cells between CTVT and MCTVT, the insertion of the specific gene fragment in the 5′ end of c-myc characteristic for a CTVT cell was also confirmed in MCTVT. However, as inoculating back to dogs, the MCTVT showed a much more aggressive growth and much higher metastatic frequency than a common CTVT. The goal of this research was to explore the gene expression differences between CTVT and MCTVT, and tried to delineate the mechanisms of their growth pattern differences. The differential gene expressions between the 2 tumors were studied using Affymetrix. Studied by hierarchical analysis and filtering the differential expressed genes by 2-fold method, we have found 105 genes significantly up-regulated and 37 down-regulated in MCTVT comparing to CTVT. Many of these genes were previously published to be involved in the areas such as malignant candidate genes, important biological processes, tumor development and immune modulation. We then used Real-Time RT-PCR to study the top 30 up-regulated genes. Three genes (APOC1, MMP1 and KMO) were further confirmed that were significantly up-regulated in MCTVT. The three genes were then tested in 22 spontaneous canine mammary gland tumors (CMGT) using Real-Time RT-PCR, the results indicated that two out of the three up-regulated genes discriminated malignant from benign CMGT and their gene expression was significantly higher in grades 4 and 5 malignant CMGT than those from lower grade tumors. We are currently studying the activities of KMO in association with the tumor cell growth. This study presented the novel candidate gene (KMO) that might associate with the malignant growth of tumor cells and has potential to be used as a biological marker to differentiate degrees of malignancy.
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B58.
Abstract B59: Induction of TXNIP in response to metabolic changes associated with loss of p53
Authors: Wheatley Karrie , Nogueira Leticia , Perkins Susan N. , Hursting Stephen D. 
Published: May 2012

Abstract
The understanding of the function of p53 has expanded beyond its role as a master cell cycle regulator. Recent findings connect p53 to cellular metabolism in that it suppresses anaerobic metabolism, the preferred mode of ATP production of most transformed cells. Interestingly, the p53-inducible genes that modulate metabolism also alter production or scavenging of reactive oxygen species (ROS). To better understand the metabolic changes that occur in response to p53-deficiency, we compared the expression of genes related to oxidative stress in the mammary fat pad of p53 +/+ and p53 +/− female mice. From a qPCR array that measured the expression of 85 genes, thioredoxin-interacting protein (TXNIP) levels were markedly increased in the p53 +/− mice compared to p53 +/+ mice (n = 3/group). This gene is of particular interest because TXNIP expression is increased by glucose flux and binds reduced thioredoxin, resulting in accumulation of ROS which has been shown to activate p53. To validate this finding, qPCR was performed (n=6/group) and TXNIP mRNA expression was increased 2.6 ± 0.2 fold (p &lt; 0.001) in the mammary fat pad of p53 +/− mice compared to p53 +/+ mice. Importantly, the p53 +/− mice exhibited significantly lower fasting glucose levels than 53 +/+ mice (104.2 ± 7.0 versus 128.5 ± 3.1 mg/dL, p &lt;0.01). We hypothesized that induction of TXNIP is in response to metabolic changes occurring with loss of p53. Using siRNA to knockdown p53, we tested this hypothesis and found that TXNIP mRNA expression increased 2.4 ± 0.3 fold (p &lt; 0.01) 72 hours after p53 knockdown compared to control cells receiving scrambled siRNA. Furthermore, this increase was preceded by a spike in glucose consumption and lactate production. From these data, we conclude that TXNIP, in the absence of p53, is responding to changes in cellular metabolism. Current experiments are aimed at determining the effect of TXNIP induction in MCF7 cells on proliferation and glucose metabolism.
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B59.
Abstract B60: HPP1-mediated tumor suppression and interferon signaling
Authors: Hernandez Jonathan M. , Elahi Abul , Shibata David 
Published: May 2012

Abstract
Interferon resistance is common to the majority of cancer cell lines and primary tumors, and confers increased tumorigenicity and evasion of immune surveillance. HPP1, a recently characterized tumor suppressor gene associated with STAT1 signaling, is silenced in the majority of colorectal neoplasms. We have sought to determine if HPP1's tumor suppressive effects are mediated by interferon-associated pathways and whether HPP1 is capable of restoring sensitivity to interferon. We have overexpressed HPP1 in the HCT 116 colorectal cancer cell line and, by microarray analysis, have demonstrated that ectopic expression of HPP1 resulted in a dramatic upregulation of STAT1 as well as a number of associated interferon-inducible genes. We have previously shown that downregulation of STAT1 by siRNA in HPP1 transfectants results in a restoration of growth potential. Given that STAT1 homodimers bind specifically to promoter GAS (gamma activating sites) sites causing transcriptional upregulation of target genes, we transfected luciferase GAS reporter (pLucGAS) and control plasmids into HPP1 and control transfectants. Overexpression of HPP1 was associated with a significant increase in GAS site binding (p=0.007), suggesting that HPP1 mediates tumor suppression via its association with Type II-like (gamma) interferon pathways. To investigate the importance of Type II-like pathways, we treated HCT 116 cells, with and without overexpression of HPP1, with increasing doses of interferon gamma. Induction of activated STAT1 (phosphoSTAT1), was demonstrable in HPP1-overexpressing transfectants with a progressive rise concordant with interferon dose escalation. Interferon gamma was unable to induce any augmentation of activated STAT1 in controls. Despite progressive induction of phosphoSTAT1, no significant alterations in proliferation, apoptosis or cell cycle distribution were observed with interferon gamma treatment of HPP1 transfectants. We conclude that activated STAT1 and Type II-like interferon-associated pathways are important in mediating the tumor suppressive effects of HPP1. The lack of additional anti-proliferative effects of interferon on HPP1 transfectants may be due to saturation of the pathway. However, further investigation of the role of other STAT1-associated mechanisms in HPP1 tumor suppression, such as the Type I-like interferon (alpha) pathway is warranted.
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B60.
Abstract B66: Aggressiveness of MMTV-Wnt-1 mammary tumors corresponds with enrichment of a CD44+/CD24− putative cancer stem cell population
Authors: Smith Sarah M. , Chiao Lucia J. , Salcido Crystal D. , Varticovski Lyuba , Hursting Stephen D. 
Published: May 2012

Abstract
MMTV-Wnt-1 transgenic mice develop heterogeneous mammary tumors that accurately recapitulate human basal-like breast cancer. Additionally, targeted alterations in the Wnt signaling pathway in mammary epithelial cells preferentially induce mammary cancers from progenitor cells. Therefore, we hypothesized that MMTV-Wnt-1 mammary tumors harbor cells with cancer stem cell characteristics. To test this hypothesis, we characterized (in vitro and in vivo) two newly generated, clonal mammary epithelial cell lines (WA4 and WG4) from a MMTV-Wnt-1 transgenic mouse tumor. The cell lines were analyzed using flow cytometry for CD44 and CD24 cell surface markers (a CD44+/CD24− profile is indicative of putative human and murine mammary cancer stem cells), mammosphere formation (low density seeding on non-adherent plates in stem-cell media), in vitro scratch assay (to measure wound healing), and by an in vitro Matrigel invasion chamber assay (to quantitate cell invasion). Finally, unsorted WA4 and WG4 cell lines were transplanted into syngeneic mammary fat pads of C57BL/6 mice (1×10^7 cells/mouse; n=5/cell line), and tumor burden was assessed after 3 weeks. Flow cytometric analysis demonstrated that the percentage of CD44+/CD24− cells was 62.2% in the WA4 line and 2.4% in the WG4 line. Serum starvation enriched the WA4 line for CD44+/CD24− cells (from 62.2% to 82.0%), without altering the composition of the WG4 line. Approximately 30% of unsorted WA4 cells, but &lt;1% of unsorted WG4 cells, formed mammospheres. Additionally, the WA4 line showed increases in wound healing by scratch assay and significant increases in invasion (226-fold increase versus WG4 cells after 30 hours). In vivo, the WA4 cell line was associated with larger, more aggressive tumors on average (+SD) than the WG4 line (2.09 +/−0.68 g and 0.03 +/−0.02 g, respectively, p&lt;0.0001). WA4 tumors were characterized by increased cellular proliferation, microvascular proliferation, and a basal appearance lacking ductal structures. In conclusion, MMTV-Wnt-1 transgenic mouse mammary tumors harbor a CD44+/CD24− putative cancer stem cell population, and an increased percentage of this population corresponds with a more aggressive tumor phenotype.
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B66.
Abstract B67: Influence of black cohosh and its isolated triterpenes on tamoxifen-induced endometrial cell proliferation
Authors: Dietz Birgit M. , Hagos Ghenet K. , Yao Ping , Lantvit Daniel D. , Chen Shao-Nong , Goedecke Tanja , Farnsworth Norman R. , Pauli Guido F. , Bolton Judy L. 
Published: May 2012

Abstract
The selective estrogen modulator tamoxifen has been proven efficacious in the treatment and prevention of breast cancer. However, tamoxifen treatment leads to consequences of estrogen deprivation including inducing menopausal hot flashes. In addition, tamoxifen causes enhanced endometrial cell proliferation resulting in an increased endometrial cancer risk. The latter effect is thought to be due to pro-estrogenic effects specific to the endometrium. The botanical dietary supplement black cohosh (Cimicifuga racemosa) is frequently used for the alleviation of hot flashes in this high-risk population. Black cohosh extracts contain antioxidative, antiproliferative, anti-inflammatory, and detoxification enzyme inducing compounds. We therefore analyzed whether a standardized black cohosh extract or its isolated compounds prevent tamoxifen induced endometrial cell proliferation. First, we analyzed the influence of black cohosh on the proliferation in the Ishikawa endometrial cancer cell line with and without tamoxifen. At concentrations of 30 µg/mL black cohosh significantly decreased endometrial cell proliferation as measured by the SRB assay in the presence as well as in the absence of tamoxifen. Assaying various black cohosh fractions and isolated compounds revealed that a small sub-fraction of the triterpenes contained within black cohosh were responsible for the observed activity. Both, the extract and its sub-fraction, induced G1 cell cycle arrest. Next, we analyzed the influence of black cohosh extract on tamoxifen induced endometrial cell proliferation in an immature rat model. The results demonstrated that black cohosh extract did not influence tamoxifen's uterotrophic activity in vivo suggesting that the concentrations achieved in vivo with commonly used black cohosh doses are too low for this effect. Further analysis is ongoing to explore the potential of the isolated active compounds in preventing tamoxifen enhanced endometrial cancer risk.
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B67.
Abstract B68: Pomegranate extract inhibits growth and viability of human pancreatic cancer cells in vitro
Authors: Nair Vidhya R. , Dai Zhaoli , Khan Maruf , Ciolino Henry P. 
Published: May 2012

Abstract
Pancreatic cancer is highly resistant to chemotherapeutic agents, and therefore new therapeutic and chemopreventive agents are needed. In the present study we examined the effect of pomegranate extract (PE) on human pancreatic cancer cells in vitro. We studied two human pancreatic cell lines, the aggressive AsPC line derived from pancreatic adenocarcinoma, and the slow growing PANC-1 cell line derived from pancreatic epitheloid cell carcinoma. PE inhibits proliferation in both the cell lines in a concentration-dependent manner, with an IC50 of 100 (both cell lines) µg per ml of culture medium. PE caused a concentration-dependent cell cycle arrest in G2/M in AsPC cells. Higher concentrations of PE were cytotoxic to both cell lines, with an IC50 of 250 (AsPC) and 150 (PANC-1) µg per ml of culture medium. There was a concentration-dependent increase in caspase-3 activity in both cell lines, suggesting that PE induces apoptosis. These results are the first demonstration of an inhibitory effect of PE on human pancreatic cancer cells, and suggest that PE holds promise for further development as a chemopreventive and chemotherapeutic agent against pancreatic cancer.
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B68.
Abstract B70: Berberine, a putative bioactive compound from traditional herbal plant, induces apoptosis in MCF-7 breast cancer cells through p53 activation and mitochondrion-dependent pathway
Authors: Jeevitha Patil , Kim Jinhee , Kumar Pratap , Jayaprakasha G. K. 
Published: May 2012

Abstract
Plant bioactive compounds found in many plant species have been used in Chinese, Unani, and Indian ayurvedic medicine. Accumulative evidences in both in vitro and in vivo studies using berberine seem to play anti-cancer and anti-inflammatory roles in different cancer cells. Previous research suggested berberine to exhibit potential anticancer activities in the various cancer cell lines. In the present study, we have isolated a putative compound from Phellodendron amurense using methanol and purified by chromatographic techniques. The structure of the isolated compound was identified as berberine by 2D NMR and mass spectral data. The isolated berberine was tested against MCF-7 breast cancer cell line and the MCF-12f normal breast epithelial cell line for 24, 48 and 72h at various concentrations (0, 12.5, 25, 50, 100, and 200µM). Using the MTT cell viability assay, berberine has demonstrated a significant cytotoxic effect on the MCF-7 cell line (p &lt;0.05) in a time and concentration dependent manner. However, the same alkaloid did not show an effect on the proliferation of the MCF-12f normal cells. The induction of apoptosis or debilitation of cancer cells without causing excessive damage to normal cells by any natural putative compound is a key target for identifying methods of cancer prevention and therapy. Based on these results, MCF-7 cells treated with 25µM berberine for 48 and 72h were used for further studies to illustrate a time dependent induction of apoptosis with flow cytometry and agarose gel electrophoresis to identify visible DNA fragmentation. Western blotting with treated cells revealed that berberine induces apoptosis in MCF-7 cells through a mitochondrion-dependent pathway by increasing levels of pro-apoptotic protein, Bax, cytoplasmic cytochrome c, caspase-9 activity and cleavage of PARP while decreasing levels of anti-apoptotic protein, Bcl-2. Immunoblotting also suggests that p53 plays a pro-apoptotic role in berberine treated cells. We conclude that berberine inhibits the proliferation of MCF-7 breast cancer cells through an apoptotic pathway which may serve as a potential compound for cancer prevention or therapy. Further studies are needed to elucidate specific mechanism of action of this putative compound in breast cancer cells.
Citation Information: Cancer Prev Res 2010;3(1 Suppl):B70.