bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1299: PHD3 has a key role in survival and proliferation of renal carcinoma cells
Authors: Park Byeong Woo , Kim Kyung-Sup , Park Seho , Park Hyung Seok , Kim Lee-Su
Published: August 2012

Prolyl hydroxylase domain-containing protein3 (PHD3) is one of enzymes catalyzing proline-hydroxylation of hypoxia inducible factor(HIF)α- subunits, which is key regulatory event of HIF activity. In renal cell carcinoma (RCC) tissues, PHD3 is commonly expressed at markedly higher level than surrounding normal tissue. PHD3 is one of the target genes, of which the expressions are induced by HIFs. Because high level of HIF activities is known to play a crucial role in tumorigenesis of RCC, the control of PHD3 by HIFs is simply expected to be negative feedback loop. However, PHD3 shows strong tumorigenic effects in RCC by itself. The forced expression of PHD3 in Caki-1, where PDH3 is expressed at low level, stimulated the proliferation and led to tumor formation in xenografted nude mice. The knocking-down of PHD3 in A498 and 768-O RCC cell lines, where PHD3 is highly expressed, severely inhibited the cell-cycle progression and the proliferation. A498 tumors formed in xenografted nude mice were effectively shrinked by injection of lentivirus expression shRNA for PHD3. When the conditional expression system of shRNA for PHD3 was introduced to A498 cells, the xenografted tumors were completed disappeared by administration of doxycycline. The expression of p57KIP2 is characteristically reduced in RCC tissues.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1299. doi:1538-7445.AM2012-1299
Abstract 13: Expression of mutant c-KIT isoforms in fibroblasts causes tumorigenic transformation
Authors: Thaiwong Tuddow , Kiupel Matti , Yuzbasiyan-Gurkan Vilma
Published: August 2012

The type III membrane tyrosine kinase receptor c-KIT is a proto-oncogene and has been shown to harbor activating mutations in a variety of cancers in humans and dogs. Specifically, deletion in codon 556-558, changing VQWKVV to VQFV (Del2) and deletion in codon 556-557, changing VQWKVV to VQVV (Del9) have been observed in both human and canine human gastrointestinal stromal tumors (GISTs). These and similar deletions are also found in some canine mast cell tumors (MCTs). In addition, internal tandem repeat duplications in exon 11 are also observed in canine MCTs. However, the significance of these mutations in driving the tumorigenic process has not been previously assessed. To directly test the hypothesis that mutant c-KIT isoforms observed in spontaneous tumors in humans and dogs are capable of driving the tumorigenic process, each isoform was ectopically expressed in canine primary fibroblasts which normally do not express c-KIT. Transfection of cells with constructs each expressing either the two exon 11 deletion mutants (Del2 and Del9) and one exon 11 duplication mutant, but not normal c-KIT, resulted in neoplastic transformation in vitro. Each transformed cell line was evaluated for the tumorigenic phenotype via the ability to invade matrigel, grow on soft agar and grow in low serum. All transformed cells displayed an invasive tumorigenic phenotype in contrast to normal fibroblasts. In vivo tumorigencity of each transformed cell line was evaluated using subcutaneous injection of one hundred thousand or one million cells of each cell line at three sites each in NSG (NOD scid gamma) immunodeficient mice. All transformed cell lines resulted in tumors at the injection site regardless of the dose. Histologically, all appeared to be sarcomas, with some showing ostoid deposition, thereby warranting the diagnosis of osteosarcoma. With Del2 transformed cells, five of the six tumors were osteosarcomas with two showing metastatic lesions upon necropsy. With Del9 transformed cells three out of six tumors were osteosarcomas and no metastasis was noted. With the duplication mutation three out of the six tumors were osteosarcoma. These findings provide strong support that these mutant c-KIT isoforms are sufficient to derive the tumorigenic process.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 13. doi:1538-7445.AM2012-13
Abstract 1447: Investigating susceptibility to sporadic osteosarcoma by genome-wide copy number analysis
Authors: Porat Rinnat M. , Pasic Ivan , Shlien Adan , Gokgoz Nalan , Andrulis Irene , Wunder Jay S. , Malkin David
Published: August 2012

Constitutional copy-number variants (CNVs) frequently overlap genomic regions that contain genes associated with cancer. In addition, copy number alterations (CNAs) in tumors often coincide with sites of CNVs and may arise through progression of CNVs. Osteosarcoma (OS), the most common human bone malignancy, can arise in familial or sporadic forms. While germline mutations of tumor suppressor genes have been implicated in a minority of OS cases, little is known about genetic changes that contribute to the etiology of sporadic OS. Using high-resolution SNP/CNV arrays, we observed a higher global germline CNV frequency in patients with sporadic OS compared to healthy controls. Given the early age of onset and the extensive constitutional CNVs, we hypothesize that these genomic alterations are linked to susceptibility to OS. Here we investigate whether specific constitutional CNVs are related to susceptibility to sporadic OS and whether OS tumor CNAs arise via progression of constitutional CNVs in these patients. Blood derived DNA samples from patients with sporadic OS with wild-type germline p53 sequence and gene dosage were selected for analysis on Affymetrix GW6.0 arrays with paired pre-therapy tumor biopsies. Initial results from a discovery set of samples (n=43 pairs) reveal a copy number loss at 1q43, in a region that overlaps several genes that have a role in bone formation, microtubules and cytoskeletal organization. This loss was present in 43% of the blood-derived DNA samples and 44% of the tumor-derived samples, whereas this variant was noted in only 1.2% of controls. Furthermore, the germline 1q43 deletion correlates with poor survival of the OS patients (p=0.04, Long Rank). Analysis of an independent validation set (n=32 pairs) is currently underway to confirm the initial finding and further characterize specific constitutional CNVs among sporadic OS patients. The findings of this study will open new avenues for the discovery of novel loci implicated in susceptibility to OS with potential for improved diagnostic and prognostic options as well as further insight into disease pathogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1447. doi:1538-7445.AM2012-1447
Abstract 1449: Spicing up radiation treatment for prostate cancer
Authors: Venier Natalie A. , Colquhoun Alexandra J. , Loblaw Andrew , Fleshner Neil E. , Klotz Laurence H. , Venkateswaran Vasundara
Published: August 2012

Introduction and Objective: Radio-sensitizing agents sensitize cells to the lethal effects of ionizing radiation (IR). This permits use of lower doses of radiation to achieve equivalent cancer control thereby minimizing adverse effects to normal tissues. Given their lack of toxicity compounds occurring naturally in the diet make ideal potential radio-sensitizing agents. Capsaicin is the active compound chilli peppers. Traditionally capsaicin is used to treat chronic pain syndromes; however, recently evidence using in vitro prostate cancer (PCa) models describes its anti-carcinogenic potential. In our preliminary studies we have demonstrated the radio-sensitizing capacity of in PCa cells in vitro. Cells treated with capsaicin and/or IR to have increased expression of pro-apoptotic tumour-suppressor proteins p21 and p27 and reduced androgen-receptor. The objective of the present study is to assess the radio-sensitizing capacity in an in vivo model. Methods: Athymic nude mice were inoculated subcutaneously with human PCa (LNCaP) cells. Once xenografts reach 100mm3 forty animals will be randomized into 4 groups (15 /group); control (no treatment), capsaicin alone, ionizing radiation (IR) alone and capsaicin and IR. Treatments were administered over a two-week time period. Capsaicin (5 mg/kg/d) or vehicle was administered 3/week by gavage. RT will be delivered to animals in sterile cages as one fraction (6 Gray). Control animals were mock irradiated. Tumours were measured thrice weekly and volumes were calculated. Tumours were fixed and stained for pathological analyses and immunohistochemical evaluation. Results: There were no differences in food consumption or body weight of mice between groups. Two mice experienced mild to moderate inflammation of the stomach. No other toxicities were observed. Mice treated with capsaicin or IR alone had a significant reduction in tumour growth overtime (p < 0.001). Mice treated with capsaicin and IR capsaicin had a reduction in the tumour volume greater than either capsaicin alone (p<0.001) or radiation alone.(p<0.03) We are currently investigating mechanism. Conclusion: These studies confirm the radio-sensitizing capacity of capsaicin in PCa xenograft model cells. Ongoing studies using are further delineating the mechanism of interaction of these treatment modalities.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1449. doi:1538-7445.AM2012-1449
Abstract 1453: The cannabinoid Win55, 212-2 enhances the response of breast cancer cells to radiation
Authors: Emery Sean M. , Sumner Evan T. , Lichtman Aron H. , Gewirtz David A.
Published: August 2012

Win55, 212-2 (Win2) is a full efficacy agonist for the endocannabinoid system, which is the target of Δ9-tetrahydrocannabinol (THC), the psychoactive compound in marijuana. Cannabinoids have demonstrated antiproliferative actions in many preclinical cancer models both in vitro and in vivo. The current studies were performed in the MCF-7, MDA-MB-231, or 4T1 breast cancer cell lines. Trypan blue exclusion was utilized as a measure of cell viability. Flow cytometry with propidium iodide was used for cell cycle analysis, while apoptosis and necrosis were assessed by Annexin V/PI staining. Win2, at concentrations of 4, 8 and 12μM, enhanced the antiproliferative effects of ionizing radiation (2, 4 and 8 Gy doses) in MCF-7 cells. The combination of Win2 and IR was also shown to be effective in MDA-MB-231 and 4T1 cells. This interaction was confirmed in vivo in 4T1 cells using 5mg/kg Win2 administered twice weekly in combination with one 10Gy dose of radiation. Win2 (8μM) for 24 hrs and 1 x 2Gy radiation was used for all subsequent experiments (Win/IR). Interestingly, neither THC nor the non-psychoactive cannabinoid, Cannabidiol, enhanced the response to radiation in MCF-7 cells, suggesting a possible drug-class specific effect. A time course study using Win/IR in MCF-7 cells suggested that Win2 and IR each alone induced growth arrest while the combination caused cell death. Cell cycle analysis indicated that at 24 hrs radiation alone (2 Gy) had no significant effect on cell cycle distribution; however, Win2 either alone or in combination with radiation produced a robust G1 accumulation. At 48 hrs, Win2 alone or in combination with radiation caused a significant increase in the subG1 population, implicating necrosis or apoptosis; however Annexin V/ PI staining was not consistent with either mode of cell death. The absence of apoptosis or necrosis lead us to believe that autophagy may be involved; however, the late autophagic inhibitor, Chloroquine (CQ), was unable to alter the effects of Win/IR, suggesting that autophagy is also not playing a primary role. Taken together, the absence of strong evidence for apoptosis, necrosis or autophagy suggests that the subG1 population could reflect necroptosis, and studies are underway to assess this possibility. Although the mechanisms of drug-radiation interaction remain to be defined, it is clear that Win2 does enhance the effects of radiation in breast cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1453. doi:1538-7445.AM2012-1453
Abstract 1455: Knock down of the aryl hydrocarbon receptor sensitizes human breast carcinoma cell lines to radio- and chemotherapy
Authors: Goode Gennifer D. , Eltom Sakina
Published: August 2012

Breast cancer is the most common cancer in North American women and is the second leading cause of cancer deaths in women today. Despite recent advances in treatment of breast cancer the development of chemo- and radio-resistance remains a major obstacle in treating advanced breast cancer. The aryl hydrocarbon receptor (AhR) is overexpressed and constitutively activated in several human breast carcinoma cell lines and the expression levels showed strong correlation with the degree of the tumor malignancy. In the current study, we evaluated the effect of reducing AhR expression on the chemo- and radio-sensitization of the MDA-MB231 human breast cancer cell line. We stably knocked down (KD) AhR expression in MDA-MB231 by using retroviral vectors expressing AhR-specific shRNA. Results show that reducing AhR expression enhanced radiation-induced apoptosis as shown by FITC-annexin V assay as well as significantly reducing cell clonogenic survival of MDA-MB231 cell line. In addition, knockdown of AhR alone has significantly impacted expression of genes regulating apoptotic pathways in these cells; increasing the expression of a number of pro-apoptotic genes while anti-apoptotic genes were down-regulated. Furthermore, the AhR-KD MDA-MB231 cells were sensitized to paclitaxol treatment; seen as an increase in the dose-dependent cytotoxicity compared to control cells. Our results suggest that reduction of AhR expression increases the chemo- and radio-sensitivity of MDA-MB231 breast cancer cell line. Therefore, AhR could be a novel target for enhancing efficacy of chemo and radiotherapy of breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1455. doi:1538-7445.AM2012-1455
Abstract 1462: Targeting NAD+ biosynthesis combined with radiation to enhance cell death
Authors: Triest Baukelien Van , Zerp Shuraila F. , Floot Ben , Vens Conchita , Verheij Marcel
Published: August 2012

Background and purpose: APO866 is a highly specific non-competitive inhibitor of nicotinamide phosphoribosyltransferase (NAMPT), a key enzyme in the regulation of NAD+ biosynthesis. Inhibition of NAMPT reduces cellular NAD+ levels. Among NAD+ consuming enzymes are Poly(adenosine-diphosphate[ADP]-ribose)polymerases (PARPs) and Sirtuins. As a consequence, NAD+ is involved in numerous biochemical processes, including regulation of DNA repair, replication, transcription and apoptosis. APO866 is thought to preferentially target tumor cells because of their high NAD+ turnover rates and increased dependence on NAD+ as compared to normal cells. In the present study we investigated the cytotoxic effect of APO866 alone and in combination with radiation on tumor cells in vitro and in vivo. Results: APO866, in nanomolar concentrations, induces a time- and dose-dependent depletion of cellular NAD+ levels in a panel of human tumor cell lines (U937, J16, LNCaP, PC3 and A431). In vitro, under APO866-mediated reduced NAD+ conditions, solid tumor cell lines PC3 and LNCaP show besides a cytotoxic effect also a decrease in clonogenic survival in combination with ionizing radiation (Dose enhancement factor at 10% survival: 1.34 and 1.45 resp.), which was not caused by radiation-induced enhancement of dsDNA breaks as determined by γ-H2AX nuclear foci formation, nor by induction of apoptosis. In vivo experiments with PC3 xenografts, treated with the APO866/radiation combination, show the combination is more effective than APO866 or radiation treatment alone. The time to reach 300% of the initial tumor volume was in the control group 9.5 days, for APO866 treatment 28.6 days, radiation treatment 51.4 days and for the combined APO866/radiation treatment 76.6 days. Only the combination treatment caused complete initial growth regression. No significant toxicity was observed after any of these treatments. Tumors from animals treated with APO866 showed significant reduced NAD+ levels. Conclusion: APO866 treatment depletes NAD+ and enhances tumor cell kill in combination with radiation, in vitro and in vivo. Targeting NAD+ biosynthesis together with radiation is a promising strategy to enhance tumor response.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1462. doi:1538-7445.AM2012-1462
Abstract 1465: Radiosensitization of NSCLC through modulation of autophagy and senescence
Authors: Goehe Rachel W. , Sharma Khushboo , Maiti Aparna , Gewirtz David A.
Published: August 2012

Introduction: Radiotherapy (IR) is a key treatment modality in the treatment of patients with non-small cell lung cancer (NSCLC), and is commonly combined with chemotherapy to prolong survival, although the gain is generally quite modest. An underlying cause for the relatively poor cure rate is the resistance to chemotherapy, which is partially associated with the dysregulation of cell death signaling, particularly apoptotic pathways. Thus, the current work was designed to exploit the capacity of 1,25D3 (the hormonally active form of vitamin D) to radiosensitize A549 cells. Experimental Procedure: In vitro studies assessed the effects of 100nM 1,25D3 alone, radiation alone (6 Gy) and the combination treatment of 100nM 1,25D3 concurrently with radiation in A549 NSCLC cells. Cell viability was assessed over a period of 7 days and sensitization to radiation was confirmed by clonogenic survival assays. Senescence was measured by β-galactosidase staining as well as C12FDG fluorescence measurement by flow cytometry. Levels of the senescence associated markers p21, pRb, and p53 were monitored by western immunoblotting. Autophagy was inhibited pharmacologically using 5mM 3-MA and 10µM chloroquine. Autophagy induction was monitored by acridine orange with quantification using flow cytometry, while autophagic flux was based on degradation of p62. Results: 1,25D3 sensitized A549 cells to radiation based on reduced clonogenic survival; viable cell counting indicated that the combination treatment resulted in apparently irreversible growth arrest with no significant recovery. β-galactosidase staining, C12FDG measurement by flow cytometry, and p21 expression levels were indicative of senescence by Days 3 and 5 while acridine orange staining and p62 degradation demonstrated the induction of autophagy. Pharmacological suppression of autophagy induced by 1,25D3 + IR resulted in a temporary delay of senescence. Conclusions: For many years, cancer therapy has relied on cytotoxic treatment strategies for the eradication of tumors and overall patient survival. These therapies are associated with severe and often harmful side effects. Recent studies have suggested that therapy-induced senescence could provide an alternative strategy for improving cancer therapy. Our studies demonstrate that treatment with 1,25D3 has the capacity to sensitize A549 cells to radiation treatment by the induction of senescence that is preceded by autophagy. This model could represent a novel, pro-senescence therapy treatment to promote disease intervention and therapeutic gain for NSCLC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1465. doi:1538-7445.AM2012-1465
Abstract 1468: Cerium oxide nanoparticles sensitize pancreatic cancer cells to radiation by modulating the JNK pathway
Authors: Wason Melissa S. , Colon Jimmie , Zhao Jihe , Baker Cheryl H.
Published: August 2012

Pancreatic cancer, one of the most lethal cancers, has a poor prognosis and a high mortality rate. Currently, the absence of effective therapies increases reliance on radiation therapy (RT) to treat pancreatic cancer. We have previously reported that Cerium Oxide Nanoparticles (CONPs) are selectively toxic to cancer cells and possess the ability to selectively sensitize pancreatic cancer cells to radiation-induced cell death. Radiation-induced H2O2 production was significantly increased in the presence of less than or equal to 10 µM of CONPs and radiation-induced ROS production was increased in human L3.6pl pancreatic cancer cells pre-treated with 10 µM CONPs, which correlated with a significant decrease in cell viability and clonogenicity as compared to radiation alone. Conversely, ROS production was decreased in normal hTERT-HPNE pancreatic cells without impacting cell viability. The volume of pancreatic tumors was reduced by 48% in mice treated with combination therapy compared to radiation alone. Immunohistochemical (IHC) analysis revealed that combination therapy resulted in a significant increase in tumor cell apoptosis. In the most recent study, we determined the mechanism responsible for the increase in apoptosis as a result of increased ROS levels. L3.6pl cells (radiation sensitive), PANC-1 (radiation resistant) and HPNE (normal pancreatic cells) were treated with 5 Gy radiation in the presence or absence of 10 µM CONPs. CONPs selectively increased RT-induced Thioredoxin (TRX) oxidation in the cancer cells (L3.6pl: 14.2%, p<0.001; PANC-1: 23.5%, p<0.005) which correlated with a 35-40% increase in ASK-1 phosphorylation in both cell lines. Excitingly, western blot analyses showed a selective increase in JNK phosphorylation in both radiation sensitive (L3.6pl: JNK1 at 15%, JNK2 at 20%) and radiation resistant (PANC-1: JNK1 at 36%, JNK2 at 37%) cells which correlated with an increase in Caspase 3/7 activity (L3.6pl: 36.4%, p<0.05; PANC-1: 43.1%, p<0.05) compared to radiation alone. Knockdown of JNK expression by siRNA resulted in abrogation of Caspase 3/7 activity and corresponding cell death. Combination therapy of CONPs and radiation in an orthotopic murine model produced significant increases in JNK phosphorylation and Caspase 3 cleavage shown by IHC analysis. These data suggest that CONPs may act as a radiosensitizer in treatment of pancreatic cancer through the induction of JNK activation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1468. doi:1538-7445.AM2012-1468
Abstract 1478: Bone marrow mesenchymal stem cells suppress tumor cell apoptosis and are selectively recruited to early-stage tumors
Authors: Bergfeld Scott A. , Blavier Laurence , Moats Rex A. , DeClerck Yves A.
Published: August 2012

Bone marrow mesenchymal stem cells (BMMSC) are recruited to primary tumors and have been reported to display pro-tumorigenic as well as anti-tumorigenic activities. However, the mechanisms behind their effect on tumor development are still unclear. We have isolated murine bone marrow aspirates and plated them on fibronectin/collagen I, which allows expansion of an adherent stromal cell population in 3-6 weeks. These cells express the CD44 hyaluronic acid receptor in the absence of hematopoietic (CD34), myeloid (CD45), and endothelial (CD31/VEGFR2) markers and display both spontaneous and inducible adipogenesis/ osteoblastogenesis in culture. 3D matrigel cultures of murine 4T1 mammary carcinoma cells revealed enhanced generation of tumor spheroids in the presence of BMMSC or their conditioned media. Conditioned media from BMMSC also increased 4T1 cell expansion in 2D monolayer cultures, with loss of this phenomenon after heat inactivation suggesting the presence of protein-based signaling. Cell cycle analysis of 4T1 cells treated with BMMSC conditioned media revealed no statistically significant change in mitotic potential in either growth (serum present) or growth-arrest (serum depleted) phase, as determined by PI staining and BrdU uptake. However, analysis of apoptosis in 4T1 cells treated with BMMSC conditioned media showed increased percentages of live cells by PI uptake and AnnexinV staining, as well as a reduction in caspase-3 and caspase-9 activation by colorimetric assay, as the cells entered growth arrest phase. Furthermore, treatment with BMMSC conditioned media preserved viability in 4T1 cells exposed to paclitaxel under no-serum conditions. Complementary studies of BMMSC tumor-directed migration indicate that BMMSC show preferential in vitro recruitment by murine tumor cell lines which generate reactive stroma (4T1, LL/2 lung carcinoma) vs. no stroma (B16 melanoma). In vivo recruitment of BMMSC by early-stage/slow-growing subcutaneous 4T1 tumors was also visualized by bioluminescent imaging, red fluorescence, and magnetic resonance imaging of BMMSC labeled with iron-nanoparticles. These results were confirmed by immunohistochemical evaluation of iron deposits by Prussian blue stain and by immunofluorescent detection of PKH26-labeled BMMSC. Overall, our data identify BMMSC as an important mediator of tumor cell survival/treatment resistance and reveal an enhanced tropism of BMMSC toward early 4T1 tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1478. doi:1538-7445.AM2012-1478
Abstract 1482: Abnormal abundance of senescent fibroblasts in the tumor stroma of non-small cell lung cancer patients
Authors: Puig Marta , Lugo Roberto , Giménez Alícia , Galgoczy Roland , Genís Sandra , Ramírez Josep , Gómez-Caro Abel , Gascón Pere , Alcaraz Jordi , Reguart Noemi
Published: August 2012

Although permanent cell cycle arrest through senescence has been previously regarded as a protective mechanism against tumor growth, there is growing evidence that the abnormal abundance of senescent cells observed in the stroma of some types of cancer may support cancer progression. However, the presence of senescent cells in the tumor stroma of non-small cell lung cancer (NSCLC), which is a major cause of cancer death in western countries, remains poorly defined. To fill this gap of knowledge, we set up a bank of primary human lung fibroblasts isolated from both tumor-free regions and tumors of NSCLC patients diagnosed with adenocarcinoma (ADC, n=5), squamous cell carcinoma (SCC, n=5) or large cell carcinoma (LCC, n=2) histological subtypes. Tumor-associated fibroblasts (TAFs) or patient-matched control fibroblasts (NTAFs) were seeded in collagen-coated culture dishes in culture media supplemented with 10% serum for 3 days. The presence of senescent cells was assessed by examining senescent associated signatures including increased spreading, decreased proliferation, and the positive response to the beta-galactosidase (beta-gal) assay. The beta-gal assay was negative in >90% of NTAFs (11/12). Likewise, TAFs from either ADC or SCC were negative for beta-gal assay in 80% of the patients examined (4/5), whereas <10% of cells were positive for the beta-gal assay in the remaining 20% of patients. In contrast, beta-gal positive TAFs were observed in 100% of LCC patients (2/2), with an average of ∼50% positive TAFs per patient. In agreement with these findings, LCC TAFs were poorly or non-responsive to serum stimulation in terms of cell cycle progression as assessed by flow cytometry, unlike patient-matched LCC NTAFs. Moreover, LCC TAFs exhibited a high percentage of largely spread fibroblasts, which is commonly associated with the senescent phenotype. These preliminary results strongly suggest that the senescent phenotype is absent in normal fibroblasts, and abnormally and specifically present in lung fibroblasts from the tumor stroma of LCC patients, therefore revealing the presence of NSCLC-subtype specific alterations in the tumor microenvironment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1482. doi:1538-7445.AM2012-1482
Abstract 1489: The role of bone marrow adipocyte-induced HO-1 expression in prostate tumor survival in bone
Authors: Hardaway Aimalie L. , Herroon Mackenzie K. , Rajagurubandara Erandi N. , Turchick Audrey , Podgorski Izabela
Published: August 2012

Prostate cancer (PCa) is the second leading cause of cancer deaths among men in the United States. Obesity, adipocyte-derived signals, and adipose tissue inflammation are major contributors to development of aggressive PCa, with higher recurrence and higher mortality rates. Bone is a primary site of metastasis of PCa and obese and overweight men have a three-fold higher risk of progression to metastatic disease compared to normal-weight men receiving the same treatment. Experimental and clinical evidence indicate that bone marrow adipocyte numbers increase with age and obesity and their increased presence affects homeostasis in the bone microenvironment. It is not, however, currently known how adipocyte-derived factors influence tumor growth and survival in bone. Heme oxygenase 1 (HO-1) is a stress-responsive protein induced by hypoxia and inflammation, and it has been shown to play a role in prostate carcinogenesis and cell survival. Its role in tumor cell aggressiveness and survival in response to adipocyte-derived signals has not been previously explored. Here, we investigated the effects of bone marrow adipocyte-derived factors on HO-1/IL-1α pathway in PCa cells. Our study was driven by hypothesis that adipocytes increase invasiveness and survival of PCa cells via upregulation of HO-1. We utilized Taqman RT PCR analyses and western blotting approaches to demonstrate that levels of HO-1 and its inducer IL-1α increase in PC3, DU145 and C42B prostate cancer cell lines in response to treatment with adipocyte conditioned media (Adipo CM). Immunofluorescence analyses and subcellular fractionation methods were used to demonstrate a translocation of HO-1 from the cytoplasm to nucleus upon exposure to Adipo CM. Invasiveness of PCa cells in response to adipocyte-derived factors in the absence and presence of IL-1α neutralizing antibody and HO-1 inhibitor Zinc protoporphyrin IX was assessed using Boyden chamber assays. Studies are currently underway to determine the significance of HO-1/IL-1α upregulation in tumor cells survival and response to chemotherapy. Collectively, the results of our studies demonstrate that adipocyte-induced upregulation of HO-1/IL-1α pathways may be playing a significant role in promoting prostate tumor aggressiveness and survival.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1489. doi:1538-7445.AM2012-1489
Abstract 1491: Tumor-associated stromal cells increase malignancy of human colorectal cancers through epithelial-to-mesenchymal transition
Authors: Mele Valentina , Muraro Manuele Giuseppe , Calabrese Diego , Amatruda Nunzia , Amicarella Francesca , Zuber Markus , Bocelli-Tyndall Chiara , Martin Ivan , Terracciano Luigi Maria , Spagnoli Giulio Cesare , Iezzi Giandomenica
Published: August 2012

BACKGROUNDS & AIMS: Exogenously administered mesenchymal stromal cells (MSCs) have been shown to migrate into tumor tissues and contribute to tumor development. Still unclear is however, whether MSCs are actually a component of the stroma associated with primary tumors. The mechanisms underlying this interaction also remain to be characterized. Here we investigated the phenotype and functional properties of tumor-associated stromal cells (TASCs) isolated from human primary colorectal cancers (CRCs) and compared them with those derived from the bone marrow of healthy donors. METHODS: TASCs, isolated from CRC biopsies, and MSCs, derived from the bone marrow of healthy donors, were cultured with CRC cells from established cell lines. Proliferation, expression of epithelial-to-mesenchymal transition (EMT)-related genes and surface markers, and the release of soluble factors were evaluated. Tumorigenicity and invasive potential of CRC cells exposed to stromal cells were also investigated in vivo. RESULTS: TASCs expanded from CRC-associated stroma resembled MSCs in morphology and phenotype. Similar to MSCs, they enhanced tumor cell proliferation through the release of soluble factors, and induced upregulation of EMT-related genes on tumor cells in vitro through the expression of surface-bound TGF-beta. Conditioning by stromal cells resulted in accelerated tumor growth and increased invasiveness of CRC cells in vivo. CONCLUSIONS: The stroma associated to primary CRCs includes MSC-like cells capable of initiating EMT on CRC cells, thus contributing to tumor growth and spreading.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1491. doi:1538-7445.AM2012-1491
Abstract 1500: Bone morphogenetic proteins stimulate mammary fibroblasts to promote mammary tumorigenesis
Authors: Owens Philip , Polikowsky Hannah , Pickup Michael W. , Matise Lauren A. , Gorska Agnes E. , Shaw Aubie K. , Novitskiy Sergey V. , Aakre Mary E. , Hong Charles C. , Moses Harold L.
Published: August 2012

Bone Morphogenetic Proteins (BMPs) are secreted cytokines/growth factors belonging to the Transforming Growth Factor ≤ (TGFβ) superfamily. BMPs have recently been shown to be overexpressed in human breast cancers, however loss of BMP signaling in mammary carcinomas has also been shown to accelerate metastases. Stimulation of dermal fibroblasts with BMP4 can enhance pro-tumorigenic factors uniquely from the epidermal response. Additionally, treatment of carcinoma-associated fibroblasts (CAFs) derived from a mouse prostate carcinoma with BMP have been reported to stimulate tumor-associated angiogenesis. We sought to determine the effect of BMP treatment on mammary fibroblasts and determine their response during mammary tumor progression. We first identified secreted pro-inflammatory cytokines and matrix-metalloproteinases (MMPs) upregulated in response to BMP4 treatment. We found that fibroblasts stimulated with BMP4 could enhance tumor invasion, which was inhibited by a BMP receptor kinase antagonist. We next demonstrated that BMP signaling was specifically absent in the stroma of human ductal and lobular carcinoma in situ (DCIS & LCIS). Yet after progression to invasion, breast tumors of many distinct subtypes contained a stroma active for BMP signaling. We further extended these observations with human normal mammary fibroblasts and compared them to human fibroblasts from breast cancer and found that BMP was capable of inducing MMP3 and IL-6 secretion in normal fibroblasts. However carcinoma associated fibroblasts had constitutively elevated levels of MMP3 and IL-6 that corresponded to enhanced BMP signaling in addition to loss of secreted BMP antagonists. These experiments demonstrate that BMP may play important tumor promoting functions within the tumor microenvironment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1500. doi:1538-7445.AM2012-1500
Abstract 1512: Sunitinib-induced metastasis is tumor dependent and is mediated by c-Met/HGF pathway
Authors: Shojaei Farbod , Simmons Brett H. , Lee Joseph H. , Lappin Patrick B. , Christensen James G.
Published: August 2012

Recent studies in several tumor models indicated that treatment with angiogenic inhibitors may trigger induction of metastasis to other organs. Here we investigated modes of resistance and invasion in several tumors including 4T1 (breast), H460 (lung) and Colo205 (colorectal) using sunitinib at doses comparable to clinically utilized regimen. In comparison with vehicle-treated tumors, sunitinib increased metastasis to lung in 4T1 tumors and to peritoneal lymph node in Colo205 tumors. However, the same treatment did not induce invasiveness in H460 tumors, further suggesting that accelerating metastasis during treatment with angiogenic inhibitors is tumor dependent. Interestingly, Crizotinib (a dual inhibitor of c-Met and ALK pathways) as single agent or in combination with sunitinib reduced metastasis in all models tested suggesting a role for c-Met/HGF pathway in intrinsic- or sunitinib-induced -metastasis. Moreover, ELISA data showed that while c-Met is highly enriched in tumor cells, HGF is secreted mainly by the stroma (mouse HGF) suggesting a paracrine fashion for c-Met pathway activation in the tumors. In conclusion, our findings indicate that sunitinib-induced metastasis is tumor dependent and further supports a rationale for combination of anti-angiogenesis and c-Met inhibition in the clinic.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1512. doi:1538-7445.AM2012-1512
Abstract 1514: The Warburg effect in stromal cells drives breast cancer cell plasticity via interleukin 6
Authors: Sansone Pasquale , Ceccarelli Claudio , Storci Gianluca , Berishaj Marjan , Cricca Monica , Chang Qing , Santini Donatella , Bonafe Massimiliano , Bromberg Jacqueline
Published: August 2012

Background: Intra-tumoral heterogeneity is an emerging concept in breast cancer biology. This concept entails the notion that sub-populations within the tumor possess different biologic features and hence vary in sensitivity to therapies. The inhibition of estrogen receptor alpha (ER), a hormone based therapy (HT), is a successful therapy for luminal A breast cancer patients. However, HT resistance, due to a variety of factors such as the tumor microenvironment, plays a crucial role in breast cancer progression. Genetic alterations in the stromal fibroblasts, such as deficiency for the tumor-suppressors (TP53 and pRB) within the tumor microenvironment, are associated with poor prognosis in breast cancer. Hypothesis: We propose that stromal cells promote the intra-tumoral heterogeneity in luminal A breast cancer. We developed an in vivo model to study the crosstalk between bone marrow stromal cells (HS27) immortalized with human papilloma virus (HPV) E6 onco-protein and a luminal A breast cancer cell line, MCF-7. Results: Here we report that HS27 cells secrete high amounts of IL-6, which operates in an autocrine and paracrine fashion. Paracrine IL-6 from HS27 cells contributes to MCF-7 cancer cell dissemination and metastasis. Autocrine IL-6 drives anaerobic glycolysis (Warburg effect) and produces high levels of lactate and H+ from HS27 cells. High levels of IL-6 and lactate from the conditioned media of HS27 cells promote the expansion of a MCF-7 cells sub-population expressing high levels of lactate shuttle MCT-1 and low levels of ER. This cancer cell population exhibits invasive and metastatic potential. Finally, we show that HPV DNA positive breast cancer lesions are more biologically aggressive, and express higher levels of IL-6, than negative ones. Conclusion: This study highlights that tumor microenvironment stressors (viral infections and oncogenes) promote a complex metabolic crosstalk (anaerobic glycolysis and oxidative phosphorylation) between stroma and cancer cells, ultimately sustaining cancer progression. Grant support: DOD W81XWH-10-1-1033 to PS, NIH R01 CA87637 to JB, PRIN KTRN38 2008 to MB

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1514. doi:1538-7445.AM2012-1514
Abstract 1517: The outcome of inhibition of stromal TGFβRII in pancreatic cancer is tumor cell-dependent
Authors: Ostapoff Katherine T. , Cenik Bercin K. , Carroll Kyla , Brekken Rolf A.
Published: August 2012

An elevated level of TGF-β is a negative prognostic indicator for patients with pancreatic ductal adenocarcinoma (PDAC). Despite this, the function of TGF-β signaling in tumor microenvironment stromal cells is unclear. We have studied how TGF-β-induced signaling in stromal cells (macrophages and fibroblasts) impacts human pancreatic cancer cell lines (Capan-1, MiaPaca-2, C5LM2 and Colo357) in vitro and in vivo. The TGFβRII activity in Raw 264.7 macrophages and 3T3 fibroblasts was inhibited with 2G8, a monoclonal rat anti-mouse TGFβRII IgG. Raw cells treated with 2G8 adopt a predominantly pro-inflammatory phenotype in vitro as documented by increased Hes1 and MCP-1 expression and inhibited tumor cell migration. Colony formation in soft agar was inhibited by conditioned media (CM) of Raw cells treated with 2G8 in all lines tested, except MiaPaca-2. Raw cell CM inhibited tumor cell proliferation in vitro compared to control media-treated tumor cells, but there were no significant differences between CM from Raw cells treated with 2G8 vs. a control IgG. CM from 3T3 cells treated with 2G8 also inhibited tumor cell migration and soft agar colony formation while control CM from 3T3 stimulated soft colony formation. MiaPaca-2, Capan-1 and Colo357 cells were orthotopically injected in SCID mice and were treated with saline or 2G8. 2G8 therapy differentially affected primary tumor size, such that inhibition of stromal TGFβRII stimulated the growth of MiaPaCa-2 tumors but inhibited the growth of Capan-1 and Colo357 primary tumors compared to treatment with a control IgG. Interestingly, 2G8 which only blocks mouse TGFβRII, suppressed metastasis in mice bearing MiaPaca-2, Capan-1 and Colo357 tumors. Furthermore, in isogenic cell lines derived from a 5 week old PDAC transgenic (p48-Cre; KrasG12D; Ink4alox/lox) mouse we also found a differential response to 2G8 therapy. Subcutaneous tumors that arose from clone MPLR 2D, were repressed by 2G8 therapy while subcutaneous tumors that arose from clone MPLR3B were stimulated by 2G8 therapy. The nature of differential response of the primary tumors and the mechanism of suppression of metastasis is under vigorous investigation. Our data thus far underscore the complexity and challenge of targeting the TGF-β pathway in pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1517. doi:1538-7445.AM2012-1517
Abstract 152: Nicotine inhibits the therapeutic effects of gemcitabine in pancreatic cancer cells in vitro and in a mouse xenograft model
Authors: Banerjee Jheelam , Al-Wadei Hussein A.N. , Schuller Hildegard M.
Published: August 2012

Pancreatic cancer is a leading cause of cancer deaths in developed countries. The nucleoside analog Gemcitabine, which induces apoptosis, is widely used for the therapy of pancreatic cancer. Smoking is an established risk factor for pancreatic cancer and nicotine replacement therapy often accompanies chemotherapy. Using the two human pancreatic cancer cell lines PANC-1 and BXPC-3 in vitro, our data show that low concentrations of nicotine significantly reduces the growth inhibiting effects of gemcitabine while also significantly inhibiting gemcitabine-induced apoptosis as indicated by determination of cleaved caspase-3 in immunoassays. Analysis of other signaling proteins is currently in progress. In a mouse xenograft model with BXPC-3 cells, a 1 micromolar concentration of nicotine in the drinking water significantly reduced the therapeutic response to gemcitabine while additionally reducing the induction of pro-apoptotic proteins and the inhibition of growth stimulating proteins by gemcitabine. Our data suggest that nicotine replacement therapy and possibly also the exposure to second hand smoke may negatively impact therapeutic outcomes of gemcitabine in pancreatic cancer patients. Nicotine addiction should be treated with non nicotine agents in such patients and exposure to tobacco smoke in any form should be avoided. Supported by grants RO1CA130888 and RO1CA042829 with the National Cancer Institute.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 152. doi:1538-7445.AM2012-152
Abstract 1521: Expression of the tight junctions protein IGSF5 in the colorectal adenoma-carcinoma sequence
Authors: Briggs Alexandra , Rizvi Hira , Carothers Adelaide M. , Wang Jiping , Cho Nancy L. , Bertagnolli Monica M.
Published: August 2012

Patients with advanced adenomas are at high risk for the development of colorectal cancer, but predictors of disease progression remain elusive. Genome wide association study (GWAS) data from the Adenoma Prevention with Celecoxib (APC) Trial identified six germline single nucleotide polymorphisms (SNPs) that predicted advanced adenoma recurrence. These SNPs are located in tight linkage disequilibrium on chromosome 21 in or around the coding sequence for Immunoglobulin Superfamily Member 5 (IGSF5). This transmembrane protein localizes to tight junctions and modulates cell adhesion with its binding partner MAGI-1. We examined the expression of IGSF5 in normal colon tissue, adenomas and adenocarcinomas. By immunohistochemistry, IGSF5 was expressed in both crypt cells and stromal cells of normal human colon. With progression to adenoma and adenocarcinoma, IGSF5 expression became more membranous and diffuse in comparison to normal colon. Immunofluorescence histochemistry (IF) showed co-localization of IGSF5 with BMI-1 in normal colon crypt cells, indicating that intestinal stem cells express IGSF5. Pericryptal stromal cells expressing IGSF5 included both mesenchymal stem cells and hematopoietic stem cells, but not myofibroblasts, as indicated by IF colocalization with CD73 and CD34 but not αSMA, respectively. These results suggest that IGSF5 expression is altered in the progression from colorectal adenoma to carcinoma, and may exert its effects through stem cell modulation of intestinal homeostasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1521. doi:1538-7445.AM2012-1521