bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2306: The prognostic impact of epithelial mesenchymal transition markers in primary diffuse gastric carcinoma and their relative lymph nodes
Authors: Malouf Gabriel G. , Tomasic Gorana , Marty Virginie , Malka David , Vielh Philippe , Ducreux Michel , Boige Valerie
Published: February 2011

Background: The accumulating evidences for epithelial mesenchymal transition (EMT) are important in experiments conducted in cell culture and rodents. However, pathologists still debate the existence of EMT and its impact on cancer progression. The purpose of this present study was to investigate the distribution of EMT biomarkers in primary diffuse gastric carcinoma (DGC) and their relative lymph nodes (LN) and to correlate them with clinical outcome.

Patients and methods: The study included 51 consecutive patients who underwent surgical resection in our institution between January 1991 and December 2007 for DGC. A tissue-microarray was constructed using paraffin-embedded tissues from gastrectomy (n=51) and matched LN (n=37). Expression of c-MET, E-cadherin, cytokeratin and vimentin were assessed by immunohistochemistry (IHC) in primary DGC, their relative LN and non-tumoral adjacent tissues.

Results: Membranous c-Met overexpression was found in 32% of primary DGC and 38% of LN. Membranous E-cadherin expression was found in 70% of both primary CDG and LN. All tumors expressed cytokeratin and there was no expression for vimentin neither in primary DGC nor in their relative LN. Although there was a high correlation in E-cadherin expression between primary DGC and their relative LN (r2 = 0.93), a poor correlation for c-MET expression (r2 = 0.02) was found. Univariate analysis for recurrence-free survival (RFS) and overall survival (OS) were performed for the following parameters: TNM stage, c-MET and E-cadherin expression both in primary DGC and their matched LN. LN overexpression of c-MET was the only prognostic factor for better relapse-free survival (RFS) (HR= 2.82, CI95%:1.27-6.85) and overall survival (OS) (HR= 2.41, CI95%:1.05-5.52) for the entire cohort.

Conclusions: Our findings indicated that c-MET overexpression did not correlate between primary DGC and their relative LN and that only LN c-MET overexpression had a prognostic impact. Conversely, there was a high correlation between E-cadherin, vimentin, and cytokeratin expression between the primary DGC and their relative LN.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2306.
Abstract 231: Mechanism of bone metastasis in prostate cancer: Role of anterior gradient homolog 2
Authors: Chanda Diptiman , Sawant Anandi , Isayeva Tatyana , Ponnazhagan Selvarangan
Published: February 2011

Prostate cancer commonly metastasizes to the skeleton in advanced stages and leads to significant decline in life expectancy. In a recent study we demonstrated enhanced proliferation of the human prostate cancer cell line PC3 when cultured in the presence of bone marrow conditioned medium (BMCM). In order to identify key molecules involved in increasing proliferation rate, total RNA was isolated from PC3 cells grown in either BMCM or regular medium and subjected to cDNA microarray analysis. Results indicated a significant up-regulation of anterior gradient homolog 2 (AGR2) in the PC3 cells cultured in BMCM compared to those grown in regular medium. AGR2 is a secreted protein and originally reported for its involvement in the formation of forebrain and mucus-secreting cement gland in the frog Xenopus laevis. AGR2 is also highly expressed in human adenocarcinomas of the prostate, breast, esophagus and the pancreas and a study indicated poor survival of prostate cancer patients with higher AGR2 expression. We compared AGR2 gene expression by RT-PCR in different metastatic prostate cancer cell lines, isolated from the bone (PC3 and C4-2B), brain (Du145) and the lymph node (LnCap). Highest AGR2 expression was observed in bone metastatic cell lines, mainly PC3 cells and least expression was observed in Du145 cells. PC3 cells expressing firefly luciferase were also injected via intra-cardiac route into 6 week-old SCID mice and widespread metastases were observed in the lung, heart, adrenal and bone. Three weeks after the inoculation of the PC3 cells, the mice were sacrificed, tumor cells were harvested from various metastatic sites, total RNA isolated and subjected to RT-PCR analysis for AGR2 expression. Interestingly, highest AGR2 expression was observed in PC3 cells isolated from bone microenvironment, suggesting that AGR2 may have a potential role in prostate cancer bone metastasis. To test this hypothesis, we developed a subclone of PC3 cells with targeted knock down of AGR2 transcripts using lentivirus shRNA vector and tested the cell clone in vitro by implanting intra-tibially or subcutaneously in SCID mice. Results of this study indicated a failure of tumor development in AGR2 knocked down PC3 clones.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 231.
Abstract 2310: Snail-induced epigenetic regulation and its implication in plasticity of cellular morphology
Authors: Lin Tong , Ponn Alison , Lu Jianrong
Published: February 2011

Epithelial and mesenchymal cells exhibit distinct phenotypic and functional characteristics, yet the two cell types possess substantial plasticity and are interconvertable. Bidirectional transitions between epithelial and mesenchymal cells play crucial roles in physiological and pathological processes. Both epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are fundamental to embryonic development. In human cancer, EMT confers migratory and invasive properties on carcinoma cells, thereby promoting tumor invasion and dissemination. Moreover, EMT may endow cells with stem cell-like traits. After migrating tumor cells reach ectopic organ sites, conversion of mesenchymal tumor cells to epithelial cells through MET (including differentiation of tumor stem cells) may facilitate macrometastatic growth. However, despite its critical relevance in normal development and cancer metastasis, the molecular basis underpinning the interconvertibility between epithelial and mesenchymal states remains incompletely understood.

The zinc-finger transcription factor Snail induces EMT by directly repressing E-cadherin, a defining marker of epithelial cells. Here we show that Snail physically interacts with and recruits the histone demethylase LSD1 to the E-cadherin promoter to remove dimethylation of lysine 4 on histone H3 (H3K4m2), a histone modification associated with active chromatin. Furthermore, demethylation of H3K4m2 by LSD1 is essential for Snail-mediated transcriptional repression. In contrast to H3K4me2, the active trimethylated H3K4 (H3K4m3) mark is not a substrate for LSD1 and it remains at high levels at the inactive E-cadherin promoter despite Snail expression. In addition, Snail induces H3K27 trimethylation (H3K27m3), a repressive chromatin mark. As a consequence, the Snail-repressed E-cadherin promoter simultaneously possesses opposite H3K4m3 and H3K27m3 marks, a pattern characteristic of bivalent chromatin modifications. Bivalent chromatin domains were initially identified and are enriched in stem cells. Bivalent promoters are inactive but are poised for activation. Although it awaits to be determined whether Snail-induced chromatin bivalency might contribute to cellular stemness, this observation suggests that the E-cadherin gene repressed by Snail remains in a transcriptionally ready state for re-activation, which may be critical for MET. These results exemplify how a bivalent chromatin state is established and provide new insights into epigenetic regulation of E-cadherin transcription and the plasticity of cellular morphology.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2310.
Abstract 2317: Oct4 impacts migration of breast cancer via Epithelial-to-mesenchymal transition related manner
Authors: Hu Jiajia , Guo Quanjun , Li Na , Xiang Rong , Tan Xiaoyue
Published: February 2011

Recent studys suggest that Oct4, a key regulator in maintenance of the embryonic stem cell pluripotency and proliferation, is relevant with the malignant characteristic of breast cancer. This study aims to investigate the role of OCT4 in the mechanism underlying the migration of breast cancer. We compared Oct4 expression in cultured MCF-7 and MDA-MB-231 cell, both of them are original from breast dust epithelial cell while the migration capacity of MDA-MB-231 cell is strikingly higher than that of MCF-7 cell. Result of western blot showed that expression level of Oct4 in MCF-7 cell was much higher than that in MDA-MB-231 cell. Then, we abolished Oct4 expression MCF-7 cell using siRNA technology. Trans-well assay result showed Oct4 down-regulation significantly increased the number of migrated cells. The expressions of E-cadherin andα-SMA, accepted epithelial and mesenchymal marker separately, were examined by western blot method. Upon down-regulation of Oct4, E-cadherin expression was inhibited whileα-SMA expression was significantly up-regulated. Real-time PCR result showed Fibronetin mRNA expression was also significantly up-regulated after Oct4 down-regulation. Further, we added TGF-β1 to cultured MCF-7 cell and then examined Oct4, E-cadherin and α-SMA expression level with Western blot. The results showed that TGF-β1 significantly inhibited E-cadherin while induced α-SMA expression in both time- and dose-dependent manner. At the same time, Oct4 expression was also highly down-regulated with the treatment of TGF-β1. Interestingly, Snail expression, which is a critical transcription factor in epithelium to mesenchymal transition (EMT) program, is significantly increased with the down-regulation of Oct-4 expression. Our study seemed to implicate transcription factor OCT4 in migration of breast cancer via EMT-related manner and this effect is likely associated with the impact of Oct-4 on the expression of Snail.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2317.
Abstract 232: PAX3-FOXO1a target genes in alveolar rhabdomyosarcoma: Possible therapeutic targets
Authors: Marshall Amy D. , van der Ent Martijn A. , Grosveld Gerard C.
Published: February 2011

Rhabdomyosarcoma (RMS) is a pediatric soft tissue tumor that is derived from skeletal muscle and expresses many muscle specific proteins. Most commonly RMS presents in one of two histological subtypes; Embryonal RMS (ERMS) or Alveolar RMS (ARMS). The ARMS subtype is more aggressive, more prone to metastasis and has the poorest prognosis. Over 75% of ARMS tumors possess a t(2;13)(q35;q14), or the variant t(1;13)(p36;q14) chromosomal translocation which generates a PAX3-FOXO1a or PAX7-FOXO1a fusion protein, respectively. Using murine primary myoblasts (a likely cell of origin for rhabdomyosarcoma), PAX3 and PAX3-FKHR were ectopically expressed and microarray analysis was performed to identify differentially regulated genes. Several genes were identified and two genes, Cannabinoid Receptor 1 (Cnr1/Cb1) and the pro-apoptotic BH3-only protein Noxa (Pmaip1), were chosen for further study.

In primary myoblasts, Cnr1 is required but not sufficient to enhance the invasive capacity of PAX3-FOXO1a expressing primary myoblasts. This appears to be mediated through Cnr1 constitutive activity. In vivo the Cnr1 inverse agonist AM251 prevents lung metastasis formation in immunocompromized mice. This implicates Cnr1 as a potential therapeutic target to inhibit the metastatic capacity of ARMS tumors.

Noxa expression is increased in PAX3-FOXO1a expressing primary myoblasts in a p53-independent manner. Moreover, PAX3-FOXO1a expression, through the up regulation of Noxa, increases the sensitivity of primary myoblasts to bortezomib and GSI-1, which also induce apoptosis in a p53-independent, Noxa-dependent manner. In addition, the up regulation of Noxa increases cell sensitivity to the anti-apoptotic Bcl-2 family inhibitor ABT-737. Bortezomib treatment in vivo significantly inhibits the growth of subcutaneous ARMS model tumors and prolongs the survival of treated animals.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 232.
Abstract 2321: Expression of functional forms of αvβ3 and αvβ5 integrins, laminin-5 and vitronectin in common human tumors: Consequences for cilengitide targeting
Authors: Sipos Bence , Henopp Tobias , Kalthoff Holger , Klöppel Günter , Goodman Simon L.
Published: February 2011

Interactions between integrins and the extracellular matrix are believed to play an important role in tumor cell survival, division and metastasis, and in tumor angiogenesis. We studied the expression of integrins αvβ3 and αvβ5, and their key ligands in the extracellular matrix in freshly frozen sections of human colorectal, breast, lung and ovarian tumors. We applied immunohistochemistry using anti-integrin monoclonal antibodies specific for functional heterodimeric forms. Prominent expression of αvβ3 was strongly associated with tumor-related vessels (20/21 colorectal, 31/33 lung, 19/19 breast and 7/10 ovarian) but also in other stromal (fibroblastic) cells in >80% of the cases. αvβ5 was almost uniformly detectable in tumor stroma including vessels, showing a considerable expression in tumor cells also (mostly in lung and breast cancers). The expression of activated vitronectin in the stroma was less abundant (3/21 colorectal, 22/33 lung, 13/19 breast and 3/10 ovarian). Laminin-5 was mainly located close to tumor cells in basal lamina-like pattern and showed a considerable expression in colorectal, lung and ovarian but not in breast cancers. We conclude that targeting of αvβ3 by cilengitide may exert potent anti-stroma effects as well. The largely varying spatial distributions and expression of integrins and their ligands should be considered in targeting strategies.

Frequency (%) of moderate or strong expression (i.e. in at least 10% of tumor cells) of antigens of interest in human tumors.  ColorectalLungBreastOvarya) αvβ3Tumour cells0151620 Stromal cells90685870 Vessels959110070b) αvβ5Tumour cells29587440 Stromal cells9010010070c) VitronectinTumour cells24502140 Stromal cells15656833d) Laminin-5Tumour cells553030 Stromal cells100a / 0b97a / 73b21a / 40b80a / 25baClose to tumor cells; bdistant from tumor cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2321.
Abstract 2323: Inhibition of in vitro growth of human mesothelioma cells by CSPG4-specific monoclonal antibodies
Authors: Zeyana Rivera , Ferrone Soldano , Yang Haining , Wang Xinhui , Carbone Michele
Published: February 2011

The membrane bound chondroitin sulphate protidoglycan 4 (CSPG4), also known as high molecular weight-melanoma associated antigen (HMW-MAA), plays a role in tumor cell proliferation, growth and differentiation, as well as in angiogenesis and extracellular matrix remodeling. Contrary to the early reports which had described CSPG4 expression restricted to melanoma cells, this molecule is expressed by various types of malignant tumors. Because of its high expression on tumor cells, including cancer stem cells, and its restricted distribution in normal tissues, CSPG4 represents an attractive target for immunotherapy. The lack of effective conventional therapy and the paucity of suitable targets for immunotherapy in mesothelioma have prompted us to test whether CSPG4 is expressed by mesothelioma cells and mediates the anti-tumor activity of CSPG4-specific monoclonal antibodies (mAb). Immunohistochemical staining with mAb showed that CSPG4 was expressed on mesothelioma cells in 24 out of 40 MM biopsies with minimal expression on surrounding normal cells. Furthermore FACS analysis and western blots detected CSPG4 in all the 9 human MM cell lines tested and that the expression was induced on MM cells by their interactions with the extracellular matrix (ECM).

To test the sensitivity of MM cells to the anti-tumor activity of CSPG4-specific mAb, 3 MM cell lines were incubated with mAb TP41.2 (final concentration 10ug/ml) for up to 72hrs. Cell proliferation was determined by MTT assay. Cells incubated with normal mouse IgG antibodies were used as controls. Addition of mAb TP41.2 to cells already attached to plates had no detectable effect on their proliferation. On the other hand incubation of MM cells with mAb TP41.2 before seeding in plates markedly inhibited their growth. The effect was time-dependent. These results were observed in all 3 cell lines and each cell lines was tested 3 times. The data suggest that CSPG4 promotes MM cell growth by mediating their interactions with ECM. This conclusion is corroborated by the growth of CSPG4-positive MM cells in serum-free medium in plates coated with collagen I, collagen IV or fibronectin. Furthermore CSPG4-specific mAb decreased the expression of the angiogenic growth factors VEGF and HEY1, as determined by RT-PCR, in MM cells. These results suggest that it may be worthwhile to test the hypothesis that CSPG4-specific mAb-based immunotherapy may represent a viable approach for the treatment of MM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2323.
Abstract 2324: The cell adhesion molecule L1-CAM is expressed in non-small cell lung cancer and is a prognostic marker for progression free survival
Authors: Tischler Verena M. , Hausladen Silke , Kristiansen Glen , Altevogt Peter , Moch Holger , Soltermann Alex
Published: February 2011

Aim: The cell adhesion molecule L1 (L1-CAM) is overexpressed in a variety of human cancers and is correlated to bad prognosis. So far only lung cancer cell lines have been tested for L1-CAM expression. Therefore, we aimed to evaluate the diagnostic and prognostic value of this molecule in non-small cell lung cancer (NSCLC) tissue.

Methods: We studied tumours of 509 surgically treated NSCLC patients, assembled on a tissue microarray. The cell membrane protein expression of L1-CAM was immunohistochemically determined and semi-quantitatively scored by two pathologists. Correlations of protein expression with clinico-pathologic parameters were calculated by chi-squared tests, overall survival by the Kaplan-Meier method.

Results: L1-CAM protein was overexpressed in 8.7% of the cases. Histological subtype analysis showed that of squamous cell carcinomas 12.9%, of adenosquamous carcinomas 33.3% and of adenocarcinomas 6.7% expressed high membranous L1-CAM. High L1-CAM protein expression was significantly correlated with higher grade, larger tumour size, higher stage and vessel infiltration but not with nodal state. High L1-CAM was significantly correlated with decreased overall survival on univariate analysis and found to be an independent prognostic factor on multivariate cox regression hazard models (including pT, pN and grade, all p-values <0.05).

Conclusions: This is the first comprehensive study on L1-CAM expression in NSCLC. Particularly, epithelial expression of L1-CAM is significantly associated with shortened patient survival defining a subset of tumours with dismal prognosis.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2324.
Abstract 2332: Alphavbeta6 integrin, a downstream effector of TGFbeta, promotes prostate cancer osteolytic lesions
Authors: Li Jing , Akech Jacqueline , Pratap Jitesh , Wang Tao , FitzGerald Thomas J. , Jiang Zhong , Violette Shelia M. , Hussain Sadiq , Stein Gary S. , Lian Jane B. , Languino Lucia R.
Published: February 2011

Integrins and their extracellular matrix ligands are crucial regulators of cancer progression. We show in the present study that the alphaVbeta6 integrin is abundantly expressed in human bone metastasis and enhances metastatic bone disease, which occurs frequently in prostate and breast cancer patients.

Our analysis shows that alphaVbeta6 is upregulated in prostate cancer cells via a pro-metastatic signaling pathway mediated by TGFbeta and SMAD3. Given alphaVbeta6 ability to act as a downstream effector of TGFbeta, we tested the ability of alphaVbeta6 to mediate metastatic cancer growth in bone in vivo. We injected PC3 cells stably transfected with alphaVbeta6 in the tibiae of SCID mice. Intraosseous growth of these cells results in extensive osteolytic lesions. Micro-computed tomographic reconstruction of the various bone lesions demonstrates that expression of alphaVbeta6 promotes the appearance of osteolytic lesions beginning at 2 weeks after injection of the tumor cells, further progressing to massive trabecular and cortical bone loss by 4 and 8 weeks. In contrast, intraosseous growth of cells expressing alphaVbeta5, another alphaV containing integrin known to promote metastasis, does not result in osteolytic lesions at the same time intervals and causes woven bone deposition in the medullary cavity. Intraosseous tumors produced by intratibial injection of alphaVbeta6- or alphaVbeta5-expressing prostate cancer cells grew with indistinguishable kinetics, thus ruling out that the enhanced formation of osteolytic lesions mediated by alphaVbeta6 was simply due to accelerated tumor growth. Further analysis shows that alphaVbeta6 contributes to osteolytic lesions by selective upregulation of MMP2 levels in PC3 tumors in vivo, which, in contrast, is not observed in alphaVbeta5- PC3 tumors.

These findings show for the first time a mechanism that promotes alphaV integrin-mediated osteolysis in prostate cancer metastatic growth and suggest that the players involved are targets for future personalized therapies of prostate cancer.

Grant support: NIH R01 CA089720 (LRL).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2332.
Abstract 2333: Integrin β1 contributes to metastasis and prognosis of squamous cell carcinoma of the head and neck (HNSCC)
Authors: Wang Dongsheng , Wang Yuxiang , Amin A.r.m Ruhul , Su Ling , Muller Susan , Huang Donghai , Nannapaneni Sreenivas , Koenig Lydia , Chen Zhengjia , Pan Lin , Tighiouart Mourad , Shin Dong Moon , Chen Zhuo (Georgia)
Published: February 2011

Integrin β1 Contributes to Metastasis and Prognosis of Squamous Cell Carcinoma of the Head and Neck (HNSCC)

It is known that integrin β1 is involved in metastasis of various tumor types. We have previously demonstrated that integrin β1 not only serves as a potential biomarker, but also plays a role in metastasis of squamous cell carcinoma of the head and neck (HNSCC), evidently by increasing tumor cell invasion (AACR poster 09-Abstract-6472). To determine the significance of integrin β1 expression in the prognosis of HNSCC and the mechanism underlying the association of integrin β1 with metastatic disease, tissue specimens obtained from 207 patients with HNSCC (101 from patients with lymph node metastasis and 106 from patients without lymph node metastasis) were analyzed for integrin β1 expression, scored as percentage expression. Furthermore, integrin β1 was knocked down by shRNA in two HNSCC cell lines to investigate its effect on invasion and metastasis-related signal transduction pathways. Finally, an orthotopic xenograft metastatic model was utilized to verify the clinical and in vitro biological findings. Both univariate and multivariate statistical analysis showed that integrin β1 expression was significantly higher in metastatic primary tumors than in non-metastatic tumors (42.7% vs 32.1%, p=0.01 and p=0.03 by univariate and multivariate analysis, respectively). Integrin β1 was also found to be highly associated with the primary cancer site (oral cavity : larynx : oropharynx = 43.5% : 33.3% : 28.2%, p=0.01). Integrin β1 showed a proportional correlation with tumor stage (25.9% vs 45.9% for Stage III vs Stage IV, respectively, p = 0.02). In patients with metastasis, integrin β1 expression was inversely correlated with overall survival (p=0.02). The in vitro study showed that in integrin β1 knock-down cells, phosphorylation of FAK and MMP2 activity were down-regulated, which was associated with reduced invasion activity of these cells. Finally, the xenograft metastatic model showed that knock-down of integrin β1 significantly prevented HNSCC cells from metastasizing to the lymph node and lung (p=0.001 and p=0.02, respectively). Our study indicates that integrin β1 has a major impact on HNSCC prognosis through, at least partially, its active involvement in the regulation of metastasis. (Supported by NIH/NCI R21 CA125062 and GCC Distinguished Cancer Scholar award to ZGC and DMS)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2333.
Abstract 2339: Stimulation of sialyl Lewis X carbohydrate expression in lung carcinoma cells by neutrophils: Implications for metastasis
Authors: St. Hill Catherine A. , Farooqui Mariya , Krieser Katherine
Published: February 2011

Sialyl Lewis X (sLeX) is a carbohydrate epitope expressed on leukocytes and carcinoma cells that promotes binding of both cell types to vascular endothelium by selectin mediated processes. These binding events are crucial for leukocyte trafficking to lymphoid tissues and sites of inflammation and metastasis of cancer cells. Increased sLeX expression is correlated with advanced disease and a poor prognosis for several types of carcinomas. Synthesis of sLeX is dependent on activity of the enzymes α-(1,3)-fucosyltransferase (FucT-III) and α2,3-sialyltransferase. Exposure to tumor necrosis factor alpha (TNF-α) has been described to upregulate FucT-III resulting in increased sLeX in the airways of patients with respiratory disease, however, little is known about the molecular mechanisms involved in regulation of sLeX expression in the inflammatory tumor microenvironment. We stably transfected lung carcinoma cells with FucT-III to investigate the role of TNF-α in regulation of sLeX expression, selectin binding ability, and metastatic potential of lung carcinoma cells. Stimulation of FucT-III transfected but not mock-transfected H1299 and A549 lung carcinoma cells with recombinant TNF-α resulted in a concentration dependent upregulation of sLeX expression, increased binding of carcinoma cells to E-selectin, and increased migration of transfectants through Matrigel. Lung carcinoma cells transfected with FucT-III demonstrated high secretion of the neutrophil chemoattractant cytokines IL-8, GRO-α and MCP-1. Co-culture of lung carcinoma cells with neutrophil conditioned media and neutrophils isolated from blood at an optimal ratio of 1:5 resulted in significantly increased sLeX expression (p = 0.02 and p = 0.002 respectively). Exposure of transfected carcinoma cells to neutrophil conditioned media and neutrophils resulted in morphological changes consistent with increased invasive potential and a TNF-α dependent increased cellular migration through Matrigel. In patient lung carcinoma specimens but not in normal lung tissues, we observed areas of high sLeX expression that correlated with increased neutrophil infiltration in 80% of tumors. We conclude that FucT-III activity and sLeX expression in lung carcinomas may recruit neutrophils in the tumor microenvironment that enhance the metastatic potential of lung tumor cells. This work was supported in part by funds from the National Institutes of Health/National Cancer Institute grant K08 CA111829-04.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2339.
Abstract 2341: The Subtilisin-like proprotein convertases blockade inhibits the invasiveness of human primary melanoma with altered P53, CDKN2A and N-Ras genes
Authors: Lalou Claude , Scamuffa Nathalie , Podgorniak Marie-Pierre , Plassa Francois , Mourah Samia , Soufir Nadem , Dumaz Nicolas , Calvo Fabien , Basset-Seguin Nicole , KHATIB Abdel-Majid
Published: February 2011

Altered tumor suppressor p53 and/or CDKN2A as well as the Ras genes are frequently found in primary and metastatic melanomas. These alterations are responsible for the invasive/metastatic potential acquisition through their defective regulatory control on various MMPs and urokinase genes. Using primary human melanoma M10 cells with altered P53, CDKN2A and N-Ras genes, we found that inhibition of the proprotein convertases (PCs), enzymes involved in the proteolytic activation and/or expression of various cancer-related protein precursors reduced significantly their invasiveness. Analysis of M10 cells and their gastric and ganglion derived metastatic lesions revealed the presence of all the PCs found in the secretory pathway namely Furin, PACE4, PC5 and PC7. Expression of the general PCs inhibitor α1-PDX in these cells in a stable manner (M10/PDX) had no effect on the mRNA expression levels of these PCs. In vitro digestion assays and cell transfection experiments, revealed that M10/PDX cells present reduced PCs activity and are unable to process the PCs substrates proIGF-1R and proPDGF-A. These cells showed reduced migration, and invasion of Matrigel in vitro that paralleled decreased gelatinase MMP-2 activity and increased mRNA expression of tissue inhibitor of metalloproteinase 1 (TIMP-1) and TIMP-2. Furthermore, these cells showed decreased mRNA levels of urokinase-type plasminogen activator receptor (uPAR) and increased mRNA levels of plasminogen activator inhibitor-1 (PAI-1). Taken together, these data suggest that PCs activity inhibition has the ability to interfere with primary human melanoma cells invasiveness despite their altered P53, CDKN2A and N-Ras genes, suggesting the potential use of PCs as new therapeutic targets in melanoma.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2341.
Abstract 2346: Contribution of VLA-4 to ovarian cancer metastasis and platinum resistance
Authors: Scalici Jennifer M. , Harrer Christine , McLachlan Karen , Slack-Davis Jill
Published: February 2011

Ovarian cancer is the fourth leading cause of cancer-related death among women. The relatively poor prognosis for ovarian cancer (5-year survival of 30-40%) reflects 1) the advanced stage of disease at diagnosis and 2) the frequent development of recurrent disease refractory to front line therapy. Ovarian cancers metastasize by attaching to and invading through the mesothelium, a single cell layer of mesothelial cells lining the peritoneal cavity. The presence of invasive peritoneal metastases is associated with a poor prognosis for ovarian cancer (5 yr survival <25%). We identified the integrin VLA-4 and its ligand VCAM-1 as regulators of mesothelial invasion. VLA-4 expression correlates with the ability of ovarian cancer cells to invade mesothelial monolayers. Additionally, VLA-4 is expressed on primary ovarian cancer cells obtained from patient tumors or ascites. The contribution of VLA-4 to ovarian cancer peritoneal metastasis was evaluated using a mouse xenograft model and function-blocking antibodies directed against VLA-4. Mice were injected intraperitoneally with platinum-resistant human ovarian cancer cells; one week later the mice were randomized into four groups and treated with 1) anti-VLA-4 antibodies, 2) carboplatin, 3) anti-VLA-4 and carboplatin, or 4) control IgG. Treatment with either anti-VLA-4 therapy or carboplatin alone had no effect on tumor burden compared to the IgG control group. However, the combined treatment of anti-VLA-4 and carboplatin significantly reduced tumor burden compared to the control or either treatment alone. This study supports a role for the active involvement of VLA-4 expressed by tumor cells in the regulation of ovarian cancer chemoresponsiveness.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2346.
Abstract 2348: Frzb/sFRP3 inhibits lung metastasis of osteosarcoma
Authors: Guo Yi , Christ Alexander , Czerwinski Ariel , Ni Rui , Xie Jun , Zi Xiaolin , Hoang Bang H
Published: February 2011

Osteosarcoma (OS) is the most common primary malignancy of bone. In spite of the recent advances in chemotherapy and surgery, 40-50% of the adolescent patients develop lung metastasis, 80% of patients with metastasis at diagnosis will relapse. Survival rate has shown no significant change over past 20 years. The molecular mechanism of metastasis of OS needs to be further explored and the novel anti-metastatic target needs to be developed. Our previous data showed that Frzb (also known as sFRP3), a secreted Fz-related protein, suppressed metastasis of fibrosarcoma. In this study, we examined the anti-metastatic effects of Frzb on OS, using the 143B and LM7 cell lines as a model. Frzb expression construct was stably transfected into 143B cells and LM7 cells. Over-expression of Frzb in OS cells was confirmed by real time PCR and western-blot. In a lung metastasis nude mice model, osteosarcoma LM7 cells expressing Frzb formed much fewer and much smaller lung metastatic nodules than control cells. Frzb also decreased in vitro cellular motility in a scratch wound assay. In order to determine the potential molecular mechanism underlying the anti-metastatic effect of Frzb on osteosarcoma, we examined the expression of c-Met, S100A4 and reversal of EMT (Epithelial Mesenchymal Transition). By real time PCR and western-blot assay, c-Met and S100A4, which were extensively reported to be involved in metastasis of different cancers, were both down-regulated by Frzb. However, most of epithelial markers (E-cadherin, keratin 8, keratin18, etc) and mesenchymal markers (N-cadherin, Vimentin, fibronectin) remained unchanged. Our study suggests that Frzb has strong anti-metastatic effect on osteosarcoma. The potential molecular mechanism may be through down-regulation of c-Met and S100A4 in OS cells by Frzb, instead of reversing the EMT. Therefore, strategies to over-express or deliver Frzb in osteosarcoma may lead to a reduction of lung metastasis

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2348.
Abstract 2349: DLC1 interaction with S100A10 mediates inhibition of in vitro cell invasion and tumorigenicity of lung cancer cells
Authors: Yang Xu-Yu , Popescu Nicolae C. , Zimonjic Drazen B.
Published: February 2011

Deleted in liver cancer 1 (DLC1) is a multidomain Rho-GTPase-activating protein (RhoGAP) and a tumor suppressor in several human common cancers. DLC1's structure predicts its interaction with a number of other proteins with various cellular functions. Previously we have shown that S100A10 (also known as p11), a key plasminogen receptor on the surface of cell membrane, colocalizes and binds with DLC1 in cell cytoplasm. The binding sites were mapped to the central domain of the DLC1 and at the end of C-terminus of S100A10. The same terminus is also a binding site for Annexin A2, which is believed to regulate availability of extracellular S100A10 and, therefore, dynamics of plasmin formation. Now we demonstrate that DLC1 competes with Annexin A2 for interaction with S100A10. DLC1 binding to S100A10 did not affect DLC1's RhoGAP activity but did reduce availability of S100A10 for binding by Annexin A2. Furthermore, the expression of DLC1 also affected S100A10 expression in a dose dependent manner, and increased S100A10 ubiquitin-dependent degradation. All of the above interactions attenuated plasminogen activation and resulted in inhibition of in vitro cell migration, invasion, colony formation and anchorage independent growth of aggressive and tumorigenic lung tumor cells. Transduction of DLC1-negative breast tumor cells significantly reduced the ability of tumor cells to form pulmonary metastases as well as inhibited distant dissemination of liver tumor cells in athymic mice. Current observations provide a plausible mechanism for DLC1 antimetastatic function by negatively affecting plasminogen activation, which in turn lead to a significant reduction in invasiveness of tumor cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2349.
Abstract 2352: Critical structural determinants of maspin necessary for maspin's subcellular localization, biological, and biochemical functions
Authors: Dzinic Sijana , Meng Yonghong , Sheng Shijie
Published: February 2011

Maspin (serpin B5), is the sole member of the serine protease inhibitor superfamily whose homozygous deletion results in embryonic lethality. Furthermore, maspin stands alone as the only non-inhibitory clade B serpin, despite the accumulating evidence for maspin's tumor suppressive effects in the progression of many types of cancer including breast, prostate, and lung. In addition, maspin is exclusively an epithelial-specific serpin with distinctive functions in the nucleus, cytosol, and the extracellular space. Our previous research discovered a novel maspin partnership with serine protease-like molecules such as the zymogen form of urokinase type plasminogen activator (pro-uPA) and histone deacetylase 1 (HDAC1). Structural analyses revealed several distinctive maspin motifs and domains that may be important for partnership of maspin with its target proteins as well as subcellular localization during tumor progression. In this study we aimed to determine if these structural motifs/domains of maspin, in addition to the earlier identified reactive center loop (RCL), are indeed important for maspin complex molecular interactions and biological activities. We utilized the prostate cancer cell line DU145, expressing low endogenous levels of maspin, to deliver wild type maspin and five rational maspin mutants by adenovirus. Different maspin mutants exhibited different affinities for the pro-uPA/uPAR complex on the cell surface and different affinities for intracellular HDAC1 and cytosolic heat shock protein 90 (HSP 90). Based on our biophysical evidence, a unique KDEL motif located downstream of the RCL domain, seems to play a critical role in dictating the subcellular localization and secretion of maspin. It has been shown that the majority of proteins that have a KDEL motif at the extreme C-terminus are endoplasmic reticulum resident proteins. Our study with maspin provides the first evidence that an internal KDEL motif may suffice to direct protein subcellular localization. This finding sheds a new light into the aberrant maspin subcellular localization during tumor progression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2352.
Abstract 2359: Modeling the kinetics of metastatic progression
Authors: Eleswarapu Ananth , Hong Sung-Hyeok , Mendoza Arnulfo , Khanna Chand
Published: February 2011

Background: Metastasis has previously been described as an inefficient process - that is, many tumor cells do not survive the process of early metastasis. Metastatic cells must survive exposure to a foreign microenvironment, which can induce cell death, and to the circulation, which provides mechanical sheer stress and immune cells. By observing the kinetics of tumor growth in both ex vivo and in vivo models of metastasis, we hope to determine the relative contributions of circulatory flow and a foreign microenvironment to metastatic inefficiency.

Methods: We have developed a novel Pulmonary Metastasis Assay (PuMA), in which we observe the progression of fluorescence-tagged tumor cells in an ex vivo whole organ lung culture. The PuMA model exposes metastatic cells to a foreign microenvironment, but not to the circulation. The intravital videomicroscopy (IVVM) model exposes tumor cells to both the circulation and a foreign microenvironment. We performed serial assessments of tumor burden for the first seven days after arrival of metastatic cells to the lungs, to compare kinetics of tumor growth in both circulation-dependent and circulation-independent models of metastasis.

Results: Both the PuMA and IVVM models displayed metastatic inefficiency. The kinetics of metastatic inefficiency and recovery in the PuMA is similar to that seen in IVVM, with periods of 1) decline in tumor burden, 2) a plateau of several days, and 3) an escape, in which tumor burden grows beyond its baseline value. The magnitude of the initial decline in tumor burden, however, is greater in the IVVM model (85% decrease from baseline, at 24 hours after metastasis), than in the PuMA model (43% decrease at 24 hours).

Conclusions: These data indicate that there is a significant circulation-independent contribution to metastatic inefficiency (as seen in the decrease in tumor burden in our PuMA model), as well a circulation-dependent contribution (as seen in the greater decrease in our IVVM model). We believe that the PuMA model will be a valuable tool in studying signaling pathways that affect survival in foreign environment. Studies are now underway to use the PuMA, in combination with pharmaceutical and genetic targeting, to study the effect of individual signaling pathways on survival during early metastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2359.
Abstract 2365: Cancer cell necrosis induces tumor growth by releasing HMGB1
Authors: Kitadai Yasuhiko , Luo Yi , Ohmori Hitoshi , Fujii Kiyomu , Sasahira Tomonori , Chihara Yoshitomo , Kuniyasu Hiroki
Published: February 2011

HMGB1 secreted from cancer cells accelerates invasion and metastasis of them. HMGB1 is released from necrotic cells. In the present study, we examined the differential effect on HMGB1 of apoptosis inducer (AI) from necrosis inducer (NI). CT26 mouse colon cancer cells were treated with trichostatin A (TSA) as AI or doxorubicin (DXR) as NI. DXR treatment increased HMGB1 in cultured medium (CM), whereas TSA did not increase. DXR-treated CM accelerated cell growth and invasion, whereas TSA-treated CM did not accelerate. CT26 cells were inoculated in the bilateral dorsal subcutaneous tissues of mice, which were treated with DXR or TSA by intratumoral injection. After treatment, serum HMGB1 concentrations by DXR and TSA treatments were 228 ng/ml and 21 ng/ml, respectively. After DXR treatment, contralateral tumor and the remnant tumor showed more pronounced growth or re-growth than those treated with TSA. By the lung metastasis model by caudal vein inoculation and the liver metastasis model by intrasplenic inoculation of CT26 cells, lung and liver metastasis was more enhanced by DXR treatment than those by TSA treatment. Metastasis enhancement by DXR treatment was abrogated by anti-HMGB1 co-treatment. Re-growth of linoleic acid-induced quiescent cells was found in DXR-treated mice but not in TSA-treated mice. These finding suggest that HMGB1 released from necrotic cancer cells treated with NI might enhance re-growth and metastasis of remnant cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2365.
Abstract 2369: The adhesion molecule MCAM/MUC18 regulates the expression of Id-1 and contributes to melanoma invasion and metastasis
Authors: Zigler Maya , Villares Gabriel J. , Dobroff Andrey S. , Braeuer Russell R. , Wang Hua , Huang Li , Alani Rhoda M. , Bar-Eli Menashe
Published: February 2011

The acquisition of the metastatic phenotype of melanoma is associated with increase of the melanoma cell adhesion molecule MCAM/MUC18. We have previously shown that MUC18 plays a major role in promoting cellular invasion by regulating MMP-2 expression and activity. Here, we aim to establish the molecular mechanism by which MUC18 regulates melanoma cell invasion to promote tumor growth and metastasis. Utilizing lentivirus-incorporated small hairpin RNA, we stably silenced MUC18 expression in the metastatic melanoma cell lines A375SM and C8161 and conducted cDNA gene expression microarray analyses. We identified the Inhibitor of DNA Binding-1 (Id-1) to be down regulated by 5.7 fold as a result of MUC18 silencing. Id-1 expression has been shown to correlate with the progression of melanoma and to promote cell invasion by regulating MT1-MMP. We have found that Id-1 expression decreased significantly after MUC18 silencing in both A375SM and C8161, thereby corroborating our microarray results. Additionally, we found that MUC18 regulates Id-1 expression at the transcriptional level through regulation of ATF-3. ATF-3 was upregulated by 6 fold in our cDNA microarray analysis. ChIP analysis showed increase binding of ATF-3 to the Id-1 promoter after MUC18 silencing. Moreover, mutation of the ATF-3 binding site on the Id-1 promoter increased Id-1 promoter activity in MUC18 silenced cells. To further confirm the specificity of regulation of Id-1 and ATF-3 by MUC18, we rescued MUC18 and found that their expression was indeed inverted. Moreover, overexpression of Id-1 in MUC18 silenced cells demonstrated rescue of the invasive phenotype as well as increased activity of MMP-2 and the transcription of MT1-MMP. Collectively, our results suggest that MUC18 contributes to the malignant phenotype of melanoma via regulation of Id-1 expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2369.