bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1232: The loss of p16INK4a function is essential for Werner Syndrome mouse embryo fibroblasts to escape from senescence
Authors: Zhang Xiufeng , Wu Xiaomin , Tang Wenru , Luo Ying 
Published: June 2012

Abstract
p16INK4a is a tumor suppressor gene contributing to cell cycle arrest as a cyclin dependent kinase inhibitor. It has been shown that the expression of p16INK4a protein is up-regulated along with the cellular senescence and the loss of p16INK4a function could elongate the cellular life span. These data suggest that p16INK4a promote cellular senescence. However, it is still debated that the expression regulation of p16INK4a in mouse cells is due to cell culture condition.
Previous study has showed that mouse embryo fibroblasts (MEFs) from late generation of Werner Syndrome (WS) mice (G5 mTR−/− Wrn−/−) senesced very rapidly, and the senescent MEF cells are prone to escape senescence and spontaneously immortalize.
To understand the molecular basis for WS MEFs escaping from senescence, we compared the expression level of proteins involved in regulating cellular senescence. Western blotting showed that all immortalized WS MEFs lost their expression of p16INK4a and re-expression of p16INK4a could induced cellular senescence, suggested the loss of p16INK4a function is essential for maintaining senescence status of WS MEFs.
To further evaluate the role of p16INK4a in senescence induced by telomere dysfunction, p16INK4a-/− mice were crossed with Wrn−/− mice to generate MEFs with genotypes of p16INK4a-/−, Wrn−/− and p16INK4a-/−Wrn−/−. Growth curve of these three cell lines revealed that Wrn−/− MEFs grew slower than p16INK4a-/− MEFs, the p16INK4a-/−Wrn−/− MEFs grew about the same as p16INK4a-/− MEFs. This data suggested that p16INK4a-/− rescued the growth barriers occurred in Wrn−/− MEFs. In consistent with this, Western blotting showed that loss of p16INK4a in Wrn−/− MEFs (p16INK4a-/−Wrn−/−) could partially eliminate the DNA damage responses caused by Wrn−/−, e.g., the expression of H2AX, p19ARF. Furthermore, telomere dysfunction was initiated by introducing TRF2ΔBΔM into these cells. In response to this stimulation, Wrn−/− MEFs senesced in several passages. In contrast to this, p16INK4a-/− and p16INK4a-/−Wrn−/− MEFs could continue grow and “kicked out” the exogenous TRF2ΔBΔM in their late passages. In summary, our data suggested that in the context of telomere dysfunction, loss of p16INK4a function could prevent the cells from senescence.
This work was supported by The New Century Excellent Scholarship to Y.L, NSFC grant to Y.L. (30771194, 30970598) and to W.T. (30960152). We thank Dr. Sandy Chang from Yale University and Dr. Ronald A Depinho from Harvard University for providing transgenic mice used in this study.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1232. doi:10.1158/1538-7445.AM2011-1232
Abstract 1234: Development of a quick sensitive real-time PCR assay for measuring telomere length
Authors: Qin James , Calado Rodrigo 
Published: June 2012

Abstract
Telomeres are the ends of linear chromosomes with tandem hexameric nucleotide repeats. Its function is to protect the natural ends of chromosomes from being recognized as damaged DNA, hence contributing to chromosomal stability. Telomeric sequences shorten each time the DNA replicates; when the telomere shrinks to a certain threshold, the cell can no longer divide. Its metabolism slows down, the cell ages, and dies. This molecular clock mechanism is also associated with cancer progression and therapy. Turning off telomerase activity by shutting off telomerase activation in cancer cells will led to cellular senescence. The current gold standard method to measuring telomere length is by Southern blot; however, it is tedious and costly, and often takes up to two days to complete. Here, we describe a new, simplified automated real-time PCR assay to accurately detect the abundance of these 5’-TTAGGG-3’nucleotide repeats and determine frequency and the length of Telomere in 47 min.
The assay demonstrated to be highly reproducible and accurate for human peripheral cells.
The result has good correlation of R2=0.9939, slope=3.41, sensitivity to 1ng of gDNA and has an amplification efficiency of 100%. We evaluated this assay with 299 healthy human subjects to date ranging from 0 (core blood) to 99-year of age. The results are positive with an inverse correlation between telomere length and age, as telomeres were shorter with aging. The telomere length was measured in 13 samples using the gold standard Southern blot method and the new q-PCR method (R2 = 0.8623), significantly higher than the originally described (Cawthon NAS 2002).

We believe this fast, sensitive methodology is a powerful tool and provides a new avenue for investigators to address the full extent and significance of telomere shortening in the tumorigenic process. This new assay described here will allow for more widespread use of this technique among cancer researchers and for study of age related telomere diseases and conditions.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1234. doi:10.1158/1538-7445.AM2011-1234
Abstract 1237: Role of Src in resistance to anoikis in detachedpancreatic cancer cells
Authors: Gomes Evan , Connelly Sarah F. , Summy Justin M. 
Published: June 2012

Abstract
Pancreatic adenocarcinoma is an aggressive malignancy currently ranked as the fourth leading cause of cancer related death in the United States, with over 95% of patients succumbing to the disease within 5 years of diagnosis. The vast majority of pancreatic cancer deaths are due to metastatic dissemination of the primary tumor. The non-receptor protein tyrosine kinase, c-Src (Src) has emerged in recent years as a potential target for pancreatic cancer treatment. In vitro studies have demonstrated the importance of Src for pancreatic tumor cell adhesion, migration, invasiveness, and resistance to apoptotic death. Mouse models of pancreatic cancer have indicated an important role for Src in formation of metastases. In addition, SHP-2, a non-receptor protein tyrosine phosphatase that regulates Src family kinase activity, has been recently shown to be a key mediator of various signaling pathways and evidence has established clinical relevance for SHP-2 in human diseases. Our goal is to determine the importance of Src for discrete steps in the progression to pancreatic cancer metastasis and resistance to detachment-induced cell death and the role of SHP-2 in modulating Src activity and downstream biology during this process. We have demonstrated a rapid and robust activation of Src in L3.6 human pancreatic cancer cells that have become detached from the extracellular environment, a crucial step in the development of metastases. Also, we have observed co-immunoprecipitation between Src and SHP-2 in detached cells, suggesting a potential role for SHP-2 in regulating Src activity in detached pancreatic cancer cells. In addition, our results reveal a Src-dependent activation of the Akt cell survival cascade and the stress kinase, Jun N-terminal kinase (JNK) in detached cells. Furthermore, this study confirmed that inhibition of both Src and SHP-2 in combination sensitizes L3.6 pancreatic cancer cells to anoikis in detached cells. We hypothesize that Src activity in detached pancreatic cancer cells promotes metastasis through suppression of anoikis. We will confirm these in vitro studies by testing the effects of inhibition of Src alone or in combination with SHP-2 inhibition on metastatic tumor formation using a nude mouse experimental metastasis model. The potential use for the Src and SHP-2 signaling axes as therapeutic targets for many cancers remains largely untapped. Our studies suggest that the anti-tumor and anti-metastatic effects of Src inhibition may be improved through simultaneous inhibition of SHP-2.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1237. doi:10.1158/1538-7445.AM2011-1237
Abstract 1243: Cofilin mediates actin destabilization and shape change in replicative senescence and stress-induced premature senescence
Authors: Tsai Cheng-Han , Lin Liang-Ting , Chou Yen-Ting , Lee Yi-Jang 
Published: June 2012

Abstract
Cellular senescence is an irreversible growth arrest mechanism that prevents indefinite proliferation of mammalian cells. Change of morphology is a common characteristic of senescent cells, while the underlying mechanism has not been completely addressed. In this study, we found that the flattened and enlarged cell shape in aged WI-38 fibroblast was accompanied by reduced actin cytoskeletal organization and up-regulated cofilin-1, a member of actin depolymerization factor family. Up-regulation of cofilin-1 was also detected in various tissues (lung, kidney, heart and liver) of one-year old BALB/c mice compared to that of 6-week old mice. Forced expression of cofilin-1 in early passaged cells accelerated senescence, while knockdown of cofilin-1 in late passaged cells inhibited senescence. Hydrogen peroxide mediated stress-induced premature senescence (SIPS) also induced cofilin-1 in human lung cancer cell lines, and this phenomenon was suppressed by knockdown of cofilin-1. Up-regulation of cofilin-1 in SIPS was independent of p53, while p27kip1 was essential for cofilin-1 induced senescence. Knockdown of p27kip1 in cells treated with hydrogen peroxide or in that with over-expressed cofilin alleviated senescence. Moreover, forced expression of cofilin-1 was sufficient to induce senescence in human lung cancer cells and repress the growth of xenograft tumor in NOD-SCID mice. Taken together, we found that cofilin-1 is able to mediate the cell senescence that is important for repressing the cancer development.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1243. doi:10.1158/1538-7445.AM2011-1243
Abstract 1245: Characterization of human leukemic cell lines and changes of the characteristics according to passage number
Authors: Hur Eun-Hye , Kim Sung-Doo , Goo Bon-Kwan , Lee Sung-Sook , Lee Kyoo-Hyung , Lee Jung-Hee , Kim Dae-Young , Choi Yunsuk , Lee Je-Hwan 
Published: June 2012

Abstract
Background: Human leukemic cell lines are valuable tools for the studies on the biology of hematologic cancers and new drug development. We investigated the baseline characteristics of human leukemic cell lines and changes of the properties according to passage number.
Materials and methods: A total of 11 human leukemic cell lines were investigated in this study, including myeloid leukemia cell lines (HL60, NB4, Molm-13, MV4-11, KG-1, K562) and lymphoid leukemia cell lines (CCRFCEM, SR, U937, Molt4, Jurkat). Genetic mutations (N-Ras, K-Ras, B-Raf, FLT3-ITD, FLT3-TKD, MLL) and polymorphisms (MDR3435CT and GST genes [A, M, T]) were detected using appropriate methods such as PCR, RFLP or DNA sequencing. MDR activities were measured using Rhodamine 123 efflux assay. Establishment of xenograft model for each cell line was tried with subcutaneous injection of leukemic cells mixed with matrigel matrix into Balb/c nude mouse. Cell lines were maintained with two times of passage per week. Western blot assay was done for changes of expression of intracellular signaling pathway proteins such as ERK, p-ERK, AKT, p-AKT, and HR23B according to the passage number.
Summary of results: N-Ras mutation was found in HL60 (Gln61Leu) and Molt4 (Gly13Val), K-Ras mutation in CCRFCEM (Gly12Asp) and NB4 (Ala18Asp), B-Raf mutation in none, FLT3-ITD and MLL rearrangements in Molm-13 and MV4-11, and FLT3-TKD in none. High MDR activity was noted in KG-1 (92.5%) and other cell lines showed less than 30% of MDR activities. Mouse xenograft model was established with 7 leukemic cell lines (HL60, NB4, MV4-11, Molm-13, K562, Molt4 and CCRFCEM). ERK phosphorylation was observed in most cell lines except CCRFCEM, but AKT phosphorylation was not found in any of the cell lines. As increasing the passage number, the levels of p-ERK in K562 and HL60 significantly decreased whereas those of p-AKT in Molm-13 were elevated.
Conclusion: Our study results provide genetic and biologic data for human leukemic cell lines and show the importance of passage number of the leukemic cell lines in designing experiments.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1245. doi:10.1158/1538-7445.AM2011-1245
Abstract 1249: Metabolomic analysis of a genetically defined model of oncogenesis reveals that common oncogenic mutations result in synergistic deregulation of multiple metabolic pathways
Authors: Schafer Xenia , Smith Bradley , Spencer Cody , Land Hartmut , Munger Joshua C. 
Published: June 2012

Abstract
Oncogenesis induces profound changes to the cellular metabolic network. A number of these cancer-cell metabolic phenotypes have been found to be important for in vivo tumorigenesis. We have utilized liquid chromatography tandem mass spectrometry (LC-MS/MS) to globally profile the metabolic network of a genetically-defined experimental model of oncogenesis in an attempt to identify novel metabolic activities induced by transformation. Furthermore, we sought to delineate how common oncogenic mutations contribute to specific metabolic phenotypes. We have analyzed how dominant negative p53 and constitutively active Ras expression, either independently or in concert, impacts the metabolic activity of non-transformed parental colon crypt epithelial cells. In addition to measuring steady-state metabolite concentrations, we have employed isotope tracer analysis to measure the impact of oncogenic mutation on metabolic pathway kinetics. We find that combined p53 and Ras oncogenic mutation synergistically activates numerous aspects of central carbon metabolism including glycolysis, glutamine catabolism, and pyrimidine and purine biosynthesis. Our data indicate that many well-defined oncogenic metabolic phenotypes are the result of a cooperative effect of combinatorial mutation highlighting the importance of identifying the interaction between oncogenic signal transduction and metabolic regulation for understanding the etiology of the cancer-cell metabolic state.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1249. doi:10.1158/1538-7445.AM2011-1249
Abstract 125: Exogenous MiR-125b inhibits head and neck squamous cell carcinoma growth by suppressing Bcl-2 expression
Authors: Zhao Yuan , Pang Xiaowu , Califano Joseph , Gu Xinbin 
Published: June 2012

Abstract
PURPOSE: Head and neck squamous cell cancer (HNSCC) is one of top ten cancers in the United States. The overall 5-year survival rate of HNSCC has not improved in the past two decades. B-cell lymphoma 2 (Bcl-2), an oncogene, is a key regulator of the apoptosis to promote cell proliferation and apoptosis arrest. Therefore, targeting Bcl-2 is an attractive strategy for restoring a normal apoptotic process and inhibiting cancer cell growth in HNSCC. MicroRNAs (miRNAs) are a class of ∼22-nucleotide-long, endogenously expressed, highly conserved of noncoding RNAs with important regulatory functions in proliferation, apoptosis and metastasis. In this study, we screened eight cancer-associated miRNAs levels (mir-21, -124, -125b, -147, -200a, -200b, -200c and -429) in twenty five human tissue specimens and four cell lines, including twenty HNSCC specimens and five normal controls, and three HNSCC cell lines (JHU-13, -22 and -29) and one transformed oral keratinocytes cell line (OKF-6). Based on the screening data, we further investigated the mechanism of miRNA-125b (miR-125b) regulated Bcl-2 expression and the therapeutic potential of exogenous miR-125b in a miR-125b stable transfected HNSCC cell line. Design Methods: The miRNA expression level was determined by quantitative RT-PCR. A stable expressed exogenous miR-125b HNSCC cell line (JHU-22miR125b) was generated by using lentivirus transfection. Colony formation and MTT assayed cell growth and cell viability and Western blot was used to analyze protein expression. Results: The expression levels of mir-124 and mir-125b were significant lower in both tumor tissue and tumor cell lines than control, and mir-21 was significant higher in tumors. Thus, mir-125b was selected as a candidate for further study. The level of miR-125b in the transfected cell lines (JHU-22miR125b) was increased more than five times compared with the control cells (Transfected with vector only, JHU-22vector). The levels of Bcl-2 protein and cell viability were significantly lower in JHU-22miR125b than JHU-22 vector. CONCLUSION: Bcl-2 is a direct target in miR-125b regulated Bcl-2 expression. Exogenous miR-125b suppresses the proliferation and growth of cultured HNSCC cells. The effect of exogenous miR-125b on inhibition of HNSCC growth via suppressing Bcl-2 expression will be further validated in tumor xanografts. This work was supported in part by grants P20 CA118770 from National Cancer Institute.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 125. doi:10.1158/1538-7445.AM2011-125
Abstract 1261: A preneoplastic switch to glycolytic metabolism driven by a PI3K-induced transcriptional program
Authors: Antico Arciuch Valeria G. , Cristofano Antonio Di 
Published: June 2012

Abstract
Most cancer cells exhibit a peculiar metabolic behavior, producing energy by aerobic glycolysis instead of oxidative phosphorylation (Warburg effect). Several oncogenes directly drive this switch modulating the levels and activity of, among others, Hexokinase II, Lactate Dehydrogenase A, Pyruvate Kinase M2, and Pyruvate Dehydrogenase Kinase 1.
We have generated a Pten-/- mouse model in which the PI3K pathway is selectively activated in the thyroid epithelial cells, leading to hyperplasia which later progresses to follicular carcinoma.
Using proteomics to identify proteins differentially expressed in early hyperplastic lesions, we have found that the levels of many tricarboxylic acid cycle proteins are down-regulated in mutant thyroids. Down-regulation of these proteins is due to reduced mRNA expression, and results in reduced oxidative phosphorylation and enhanced glycolysis (over 3-fold increase in lactate production in mutants vs. wt). Furthermore, although mutant thyroids cells have a normal number of mitochondria, the expression of most mitochondrially-encoded genes is heavily down-regulated. Strikingly, none of the genes and proteins classically associated with the Warburg effect is found deregulated in the mutant thyroid cells.
Analysis of the expression of transcription factors and co-activators involved in cellular metabolism revealed that the decrease in TCA cycle and OXPHOS genes is due to a reduction in ERRα, ERRγ, PPARα and PPARγ levels. Conversely, none of the co-activators analyzed (PRC1, PGC-1α, and PGC-1β) exhibited changes in mRNA expression. Pharmacological and genetic PI3K inhibition in mouse tumor-derived thyroid cancer cell lines increased the expression levels of both TCA cycle OXPHOS genes. Moreover, it also increased mtDNA amount, suggesting that the transition from hyperplasia to cancer involves additional alterations of the metabolic machinery. Likewise, PI3K inhibition induced a marked decrease in lactate secretion. Finally, these thyroid cancer cell lines exhibited high sensitivity to glycolysis inhibitors such as 3-bromopyruvate.
Based on these compelling data, we propose a novel mechanism leading to the Warburg effect in preneoplastic lesions: PI3K activation initiates a coordinated rearrangement of the expression of metabolic genes, which favors aerobic glycolysis at the expense of TCA/OXPHOS. The elucidation of this process will lead to innovative targeted approaches to selectively disrupt tumor progression, while preserving normal metabolism in non mutated cells.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1261. doi:10.1158/1538-7445.AM2011-1261
Abstract 1264: BRCA1 induces reversion of “Warburg effect” in a breast cancer cell model
Authors: Privat Maud , Morvan Daniel , Guerrab Abderrahim El , Aubel Corinne , Bignon Yves-Jean 
Published: June 2012

Abstract
BRCA1 is a major tumor suppressor in breast cancer and it was implicated in numerous pathways resulting in anticarcinogene functions. Likewise, the hypermetabolic nature of cancer cells and their increased reliance on “aerobic glycolysis”, as originally described by Otto Warburg and colleagues, are considered metabolic hallmarks of cancer cells. The objective of our study was to address specific contributions of BRCA1 to the signature metabolic features of cancer cells, including the so-called “Warburg effect”.
The breast cancer cell line carrying the 185delAG mutation of the BRCA1 gene, SUM1315MO2 cells, was stably transfected with a wild type BRCA1 plasmid. In this cell model, we combined analysis of cell metabolism major enzymes transcriptional expression by TaqMan low density array with the investigation of metabolites by 1H-NMR spectroscopy. We demonstrated that BRCA1 transfection in mutant cells induced strong decrease of glycolysis metabolites and enzymes while TCA cycle and oxidative phosphorylation tended to be activated. Glucose assay confirmed that BRCA1-mutated cells consumed more glucose than cells expressing wild-type BRCA1. Preliminary results seem to show that BRCA1 could act on glycolysis via inhibition of the HIF1α pathway.
Our study showed a new function for BRCA1 in cell metabolic regulation, globally resulting in reversion of the Warburg effect in our breast cancer cell model.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1264. doi:10.1158/1538-7445.AM2011-1264