bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 406: Effects of an RGD peptide in osteoclast maturation and behavior as a therapeutic option for metastatic bone disease
Authors: Prager Gerald , Bianconi Daniela , Chillà Anastasia , Dorda Alexandra , Geetha Nisha , Unseld Matthias , Sykoutri Despoina , Poettler Marina , Redlich Kurt , Zielinski Christoph
Published: August 2015

Metastatic bone disease is a common feature of many types of cancer and has a severe impact on the quality of life of patients. Hence, specific therapeutic strategies inhibiting tumor induced osteolysis are urgently needed. In this study, we aimed to interfere with integrin adhesion receptors, which are central players of the bone resorption process, including osteoclastogenesis as well as osteoclast/bone matrix interaction. For this purpose, we used a cyclic RGD peptide which blocks integrin áVâ3 and áVâ5-ligand binding. Our results revealed that the RGD peptide blocked osteoclast maturation in a dose-dependent manner. In detail, pre-osteoclasts treated with the RGD peptide exhibited reduced cell spreading, migration and adhesion on RGD-containing matrix proteins, such as osteopontin and fibrinogen, which are ligands of integrin áVâ3. The activation of the most upstream signal transduction molecules of the integrin receptor-initiated pathway, such as FAK and c-Src, were consistently blocked by the RGD peptide. First evidence has suggested that the RGD peptide might interfere with metastatic bone disease in vivo and the evidence presented herein describes the underlying mechanisms of the inhibitory effect of the RGD peptide on áV-integrin expressing pre-osteoclasts by blocking integrin ligand binding and interfering with osteoclast maturation and cell behavior. In conclusion, our findings suggest that using an RGD peptide to interfere with áV-integrins on osteoclasts may represent a novel therapeutic strategy in the treatment of malignant bone disease.

Citation Format: Gerald Prager, Daniela Bianconi, Anastasia Chillà, Alexandra Dorda, Nisha Geetha, Matthias Unseld, Despoina Sykoutri, Marina Poettler, Kurt Redlich, Christoph Zielinski. Effects of an RGD peptide in osteoclast maturation and behavior as a therapeutic option for metastatic bone disease. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 406. doi:10.1158/1538-7445.AM2015-406
Abstract 4068: In vivo analysis of the residual disease uncovers early and late response of cytarabine-resistant cells in human acute myeloid leukemia
Authors: Sarry Jean-Emmanuel
Published: August 2015

The major therapeutic barrier in acute myeloid leukemia (AML) is chemotherapeutic resistance. Resistant cells to conventional chemotherapy - which targets DNA synthesis - are thought to be rare and enriched in quiescent leukemic stem cells. In order to develop an improved understanding of chemotherapy resistance in AML, we analyzed the response to cytarabine (AraC) and disease regrowth in a xenograft model with 13 primary AML patient specimens. After demonstrating AML engraftment, mice are treated with AraC given IP daily for 5 days as a single agent at 60 mg/kg daily, which correlates with human dosing. In all mice treated with AraC, there was a strong cytoreductive effect at 1 week post-treatment with regrowth at 2-8 weeks post-treatment, demonstrating that there is a dose response relationship in the model in terms of nadir leukemic burden and time to relapse. While in vivo AraC increases in hypoxic CD34posCD38neg phenotype, this treatment does not induce any significant changes in cell cycle progression and kills both cycling and quiescent cells in AML-engrafted mice. We also observed that AraC decreases the frequency of leukemia-initiating cells. Furthermore, transcriptomic analysis of residual leukemic cells from three patients-derived xenografts during disease progression (1-2-4 weeks post-AraC) reveals that the AraC resistance is associated with enrichment in genes involved into the apoptosis regulation, inflammatory and metabolism at early stage (1 week), and in stem cell markers with adverse prognosis at the onset of the tumor regrowth (2 week). Altogether, these results suggest a novel model for cytarabine resistance in AML.

Citation Format: Jean-Emmanuel Sarry. In vivo analysis of the residual disease uncovers early and late response of cytarabine-resistant cells in human acute myeloid leukemia. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4068. doi:10.1158/1538-7445.AM2015-4068
Abstract 4071: Cancer stem cell-induced vascularization of skin cancer tumors
Authors: Grun Dan , Adhikary Gautam , Eckert Richard
Published: August 2015

Our previous studies identify a subpopulation of epidermal cancer stem (ECS) cells in human squamous cell carcinoma that are efficient tumor formers. These cells display enhanced invasion and migration, and form large, invasive and highly aggressive tumors. We now show that ECS cells produce highly vascularized tumors. This is confirmed visually and by detection of increased expression of the CD31 endothelial cell marker. To understand the molecular basis for increased vascularization, we assayed for ECS cell and non-stem cancer cell production of angiogenic factors. Pro-angiogenic factors, including VEGF-A, HIF-1α and MMP9, are produced at high level in ECS cell-derived tumors, as compared to non-stem cancer cell tumors. In addition, anti-angiogenic factor production (thrombospondin-1, endothelin-1, serpin B5) is reduced. This is consistent with the finding that ECS cell tumor extracts more efficiently stimulate HUVEC cell tube formation. Moreover, these ECS tumor-derived cells display enhanced spheroid formation, and cell migration and invasion. Knockdown of VEGF-A or VEGFR2, or treatment with anti-VEGF-A attenuates these events. In addition, treatment with bevacizumab (anti-VEGF-A) suppresses tumor formation in vivo. These studies suggest that the VEGF-A signaling pathway is enhanced in ECS cells and is in part responsible the ability of these cells to form aggressive and highly vascularized tumors.

Citation Format: Dan Grun, Gautam Adhikary, Richard Eckert. Cancer stem cell-induced vascularization of skin cancer tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4071. doi:10.1158/1538-7445.AM2015-4071
Abstract 4074: Cancer stem cells in tobacco-induced carcinogenesis and subsequent effect of ATRA-based chemoprevention
Authors: Surendran Subin , Mimikos Christina , Suresh Amritha , Hicks Wesley L. , Seshadri Mukund , Kuriakose Moni A.
Published: August 2015

Introduction Chemoprevention is potentially the most effective method to lower the prevalence of head and neck squamous cell carcinomas (HNSCC), the sixth most common type of malignancy worldwide. The chemopreventive effects of retinoids against HNSCC have been previously reported. Retinoids however; relapse following cessation of medication is a critical problem that prevents its clinical use. The objective of this study was to determine the possible mechanism of retinoid resistance by exploring cancer stem cell mediated pathways.

Experimental Procedures.

In vitro cell line models of normal (NOK) and dysplastic oral keratinocytes (DOK) are being exposed to tobacco to assess the process of carcinogenic progression. The progression in the DOK and HOK cell lines will be assessed by proliferation, migration and invasion assays. The expression of stem cell markers/pathways (CD44/Hyaluronan, Wnt, Notch1, ALDH1A1) during the process of progression will be evaluated using QPCR and FACS. These cell lines will then be treated with ATRA and the subsequent effects on transformation and CSC-specific pathways further evaluated.

Summary To this end, immunostaining of normal oral mucosa, potentially malignant lesions (n = 93) and malignant lesions (n = 48) for the stem cell marker CD44 was performed. CD44+ cells were found at a density of 58.57/hpf in normal mucosa, 61.56/hpf in mild dysplasia, 119.44/hpf in moderate dysplasia, and 107.6/hpf in severe dysplasia. The density of CD44+ cells in WDSCC, MDSCC and PDSCC were 183.4, 105 and 160/hpf respectively, indicates CSC cells may represent a marker of malignant progression The cell lines are currently under exposure to tobacco and the transformational changes being documented. Apart from the studies on the changes specific to CSCs, high throughput secretome and proteomic studies are also being planned to evaluate the global changes effected due to tobacco as well as due to subsequent treatment with ATRA.

Conclusion This study hence attempts to provide novel insight into tobacco-induced carcinogenesis and mechanism of resistance to retinoid-based chemoprevention.

Note: This abstract was not presented at the meeting.

Citation Format: Subin Surendran, Christina Mimikos, Amritha Suresh, Wesley L. Hicks, Mukund Seshadri, Moni A. Kuriakose. Cancer stem cells in tobacco-induced carcinogenesis and subsequent effect of ATRA-based chemoprevention. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4074. doi:10.1158/1538-7445.AM2015-4074
Abstract 409: Docetaxel induced-JNK2/PHD1 signaling pathway increases cell death in cancer cells under hypoxia through the degradation of HIF-1α
Authors: Oh Eun-Taex , Song Min-Jeong , Lee Hyemi , Choi Yun-Jeong , Park Heon Joo
Published: August 2015

HIF-1α has been shown to regulate the expression of more than 70 genes involved in angiogenesis, tumor growth, metastasis, chemoresistance and radioresistance. There has been a growing interest in using HIF-1α inhibitors as anticancer drugs. Recently, docetaxel, which has been approved by the FDA for treatment of various cancers, has been reported to enhance the degradation of HIF-1α, but its molecular mechanism is unclear. In this study, we investigated the molecular mechanism underlying the docetaxel-induced degradation of HIF-1α and cell death in cancer cell under hypoxia. Pretreatment of docetaxel increased the polyubiquitination and proteasome mediated-degradation of HIF-1α and cell death in cancer cells under hypoxia. Under hypoxia, pharmacological inhibitors or siRNAs for PHD1 (prolyl hydroxylase 1) effectively prevented HIF-1α degradation and cancer cell death through inhibiting docetaxel-mediated activation of PHD1. In addition, siRNA-mediated knockdown of JNK2 blocked docetaxel-induced degradation of HIF-1α and cancer cell death through inhibiting the activation of PHD1. Through a luciferase reporter assay, we observed that the inhibition of the JNK2/PHD1 signaling pathway significantly suppressed the transcriptional activity of HIF-1α. Our results collectively show that, under hypoxia, docetaxel contributes to cause apoptotic cell death under hypoxia by triggering the JNK2/PHD1 signaling pathway, thereby increasing the degradation of HIF-1α.

Citation Format: Eun-Taex Oh, Min-Jeong Song, Hyemi Lee, Yun-Jeong Choi, Heon Joo Park. Docetaxel induced-JNK2/PHD1 signaling pathway increases cell death in cancer cells under hypoxia through the degradation of HIF-1α. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 409. doi:10.1158/1538-7445.AM2015-409
Abstract 4104: LIX1L, an EMT-correlated gene that behaves as if it inhibits the EMT
Authors: Yamade Mihoko , Pommier Yves , Kohn Kurt W.
Published: August 2015

Background: We previously reported that LIX1L (LIX1-like), a gene whose functions are unknown, has an expression pattern exhibiting strong negative correlation with the expression of genes of epithelial-specific functions in the NCI-60 human cancer cell line panel of the US National Cancer Institute (Kohn et al PLoS ONE 9:6, 2014). This observation suggested a possible role in the epithelial-to-mesenchymal transition (EMT) and led to the current investigation. Method]: We examined the correlation of LIX1L with gene expression in the data of the Broad Institute's CCLE cell lines and the cancer genome atlas (TCGA) tissues. We then investigated the functions of LIX1L in breast and colon cancer cell lines. We knocked down LIX1L expression by means of siRNA and overexpressed LIX1L by means of recombinant LIX1L-GFP plasmid. We also generated LIX1L knockout cell lines (LIX1L-KO) using the CRISPR/Cas system. We compared the expression levels of LIX1L with well-known EMT-related genes by Western blot and quantitative PCR. We examined the migration and invasion properties of these cell lines and constructs by means of wound healing assays, and migration and invasion assays. Results: LIX1L expression is correlated with non-epithelial or mesenchymal genes in analyses of the CCLE and TCGA gene expression data. Experiments suggested the surprising result that LIX1L-KO MDA-MB231 cell lines showed higher expression of ZEB1 and increased invasion ability. Conclusion: LIX1L gene expression is positively correlated with the expression of non-epithelial or mesenchymal genes in the NCI-60, CCLE and TCGA databases. Up- or down-regulation of LIX1L however seemed to produce the opposite of the expected phenotypic changes. Our findings suggest that LIX1L may be expressed coordinately with genes that favor epithelial-to-mesenchymal transitions in cancer cells while having a moderating effect on the transition.

Citation Format: Mihoko Yamade, Yves Pommier, Kurt W. Kohn. LIX1L, an EMT-correlated gene that behaves as if it inhibits the EMT. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4104. doi:10.1158/1538-7445.AM2015-4104
Abstract 4105: Cathepsin L inhibition reverts epithelial mesenchymal transition in prostate and breast cancer cells
Authors: Burton Liza J. , Smith Bethany , Platt Manu , Marah Valerie
Published: August 2015

The Epithelial Mesenchymal Transition (EMT) is a key event in tumor migration and invasion processes whereby epithelial cells lose polarity together with cell-cell contacts associated with loss of epithelial markers such as E-cadherin and then undergo a dramatic remodeling of the cytoskeleton associated with expression of mesenchymal markers such as vimentin, as well as increased production of extracellular matrix (ECM)-degrading proteases. Snail is a gene that promotes epithelial mesenchymal transition (EMT) by using its zinc finger domains to bind to target genes that would otherwise stop EMT. Cathepsin L (Cat L) is a cysteine protease involved in cell invasion and has recently been associated with poor prognosis in Colon and Breast Cancer with Cat L being localized in the nucleus. We have shown previously that Snail-mediated EMT can be antagonized by muscadine grape skin extract (MSKE), a natural product rich in anthocyanin. In preliminary data we found that Snail, an inducer of EMT, could up-regulate Cat L activity and expression in breast cancer cells. We hypothesized that antagonizing Cat L activity would lead to mesenchymal epithelial transition (MET). We utilized breast and prostate EMT models to analyze Cat L activity using gelatin zymography and subsequently treated mesenchymal cells with 1μM, 5μM or 20μM Z-FY-CHO (Cat L specific inhibitor) or MSKE for 72 hours. We performed western blot analysis and immunofluorescence for EMT markers as well as invasion and migration assays. Our data indicates that mesenchymal MDA-MB-231 breast cancer cells showed higher Cat L expression and activity as compared to epithelial MCF-7 breast cancer cells. Interestingly, immunofluorescence analysis revealed cells displaying a higher snail expression have an increase in Cathepsin L activity and expression as well as Cat L being localized in the cytoplasm and nucleus. Additionally, mesenchymal breast (MDA-MB-231, MCF-7 cells overexpressing Snail) and prostate (ARCaP-M, ARCaP-E cells overexpressing Snail) cells displayed decreased expression of vimentin and Cat L expression and activity when treated with Z-FY-CHO or MSKE, while E-cadherin increased suggestive of MET. This was associated with decreased cell migration and invasion. We also show for the first time that treatment with MSKE or Z-FY-CHO changes the localization of Cat L from nuclear to cytoplasmic. Based on these results, the inhibition of Cat L could play a role in reverting EMT and preventing tumor progression.

Citation Format: Liza J. Burton, Bethany Smith, Manu Platt, Valerie Marah. Cathepsin L inhibition reverts epithelial mesenchymal transition in prostate and breast cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4105. doi:10.1158/1538-7445.AM2015-4105
Abstract 4107: CCR9/CCL25 mediates epithelial-mesenchymal transition in prostate cancer
Authors: Carriere Patrick P. , Mir Hina , Kapur Neeraj , Singh Rajesh , Sonpavde Guru , Lillard James W. , Singh Shailesh
Published: August 2015

Prostate cancer (PCa) is the second leading cause of cancer-related deaths in men, despite the treatment options offered in the clinics. Hence, it is important to further elucidate the molecular mechanisms of PCa progression in order to design more effective treatment strategies. PCa metastasis is a multi-step process that involves epithelial-mesenchymal transition (EMT), during which stationary epithelial cancer cells adopt a mesenchymal phenotype that better suits for survival and motility. We have previously shown that CCR9-expressing PCa cells migrate to and invade distal secondary sites under the influence of chemokine CCL25, its natural ligand. However, the precise molecular mechanisms facilitating EMT in PCa are still not fully understood. Here, we investigated the biological significance of CCR9/CCL25 signaling in inducing EMT in PCa. Modulation of several EMT markers was assessed by western blot and real time qPCR in metastatic PCa cell lines, with or without CCL25 activation. Our results show that following CCL25 stimulation, CCR9 signaling differentially modulates expression of the EMT markers E-cadherin and N-Cadherin in PCa cells, as compared to untreated controls. These findings suggest that the CCR9-CCL25 axis plays an important role in mediating EMT in PCa, thereby increasing the ability of PCa cells to metastasize.

Citation Format: Patrick P. Carriere, Hina Mir, Neeraj Kapur, Rajesh Singh, Guru Sonpavde, James W. Lillard, Shailesh Singh. CCR9/CCL25 mediates epithelial-mesenchymal transition in prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4107. doi:10.1158/1538-7445.AM2015-4107
Abstract 411: 1,25(OH)2D3 deficiency accelerates colon cancer progression via microenvironmental regulation
Authors: Yuan Xiaoqin , Liu Yun , Chen Lulu , Miao Dengshun
Published: August 2015

Epidemiologic studies have revealed that low serum vitamin D levels are associated with an increased risk of colon cancer and inflammatory diseases such as inflammatory bowel disease (IBD) while underlying biological mechanisms remain largely unknown. It is also well established that tumor microenvironment plays an essential role in tumor progression. In this study, we sought to determine whether 1,25(OH)2D3 deficiency has a direct impact on colon cancer by using 25-hydroxyvitamin D 1-hydroxylase knockout [1α(OH)ase−/−] mice that had been fed with a rescue diet (high calcium, phosphate and lactose) from weaning. We injected CT26.WT cells (a murine colon cancer cell line) into 1α(OH)ase−/- and wild-type (WT) mice repectively and found that 1,25(OH)2D3 deficiency accelerated the growth of xenografted colon tumors. In the AOM/DSS model, heterozygous 1α(OH)ase+/− mice increased the multiplicity and size of colon tumors. Compared to WT mice, 1α(OH)ase−/− mice exhibited an increase of DNA damage, cellular senescence and the production of senescence-associated inflammatory cytokines in their colon stromal cells. These results suggest that 1,25(OH)2D3 deficiency may have a direct effect on colon cancer development, at least in part, by influencing tumor microenvironment.

Note: This abstract was not presented at the meeting.

Citation Format: Xiaoqin Yuan, Yun Liu, Lulu Chen, Dengshun Miao. 1,25(OH)2D3 deficiency accelerates colon cancer progression via microenvironmental regulation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 411. doi:10.1158/1538-7445.AM2015-411
Abstract 4112: Mechanisms of transendothelial migration by invasive breast carcinoma cells from patients
Authors: Pignatelli Jeanine , Jones Joan , Chen Xiaoming , Smith Bryan , Flynn Daniel , Condeelis John , Oktay Maja
Published: August 2015

The majority of breast cancer related deaths are not due to the primary tumor, but rather to the dissemination of metastatic tumor cells from it to distant sites. Our lab has previously identified the tumor microenvironment of metastasis (TMEM) in mouse and human mammary tumors, sites where transendothelial migration, intravasation and dissemination occur. The constituent cells of TMEM are an endothelial cell, a perivascular TIE2-expressing macrophage (TEM) and an invasive Mena-over expressing tumor cell in direct contact. TMEM are present in human invasive breast tumors and the density of TMEM is positively associated with the risk of developing metastases.

Using invasive ductal carcinoma cells of the breast obtained from patients by fine needle aspiration (FNA), we demonstrated that intravasation-directed transendothelial migration (iTEM) of these cancer cells requires macrophages and, depending on clinical subtype, involves either paracrine (macrophage CSF1-R; tumor cell EGFR), or both paracrine and autocrine (tumor cell EGFR + CSF1-R) signaling. Compared to the total population of primary breast cancer cells assayed, cells capable of transendothelial migration expressed relatively high MenaINV and low Mena11a levels, independently of clinical subtype. MenaINV and Mena11a are functionally distinct isoforms of Mena, a key regulator of motility and invasion. Depletion of MenaINV using siRNA showed that MenaINV is required for efficient macrophage-dependent iTEM of tumor cells. Furthermore, relative MenaINV expression correlated with the density of TMEM, which were previously shown to correlate with risk of metastasis in patients. From these observations we have identified the signaling pathways involved in macrophage-dependent tumor cell iTEM. Two novel small molecule inhibitors, Rebastinib (Tie2 inhibitor) and Altiratinib (c-MET inhibitor), have been identified that show great promise in preventing key steps in iTEM.

Our data reveal targetable signaling events required for transendothelial migration of human breast cancer cells, and indicate that relative MenaINV levels and TMEM frequency are correlated prognostic markers of metastasis and therapeutic targets for most human breast cancers.

Citation Format: Jeanine Pignatelli, Joan Jones, Xiaoming Chen, Bryan Smith, Daniel Flynn, John Condeelis, Maja Oktay. Mechanisms of transendothelial migration by invasive breast carcinoma cells from patients. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4112. doi:10.1158/1538-7445.AM2015-4112
Abstract 4117: Syk is a candidate kinase target for the treatment of advanced prostate cancer
Authors: Danen Erik
Published: August 2015

Improved targeted therapies are needed to combat metastatic prostate cancer. Here we report the identification of the spleen kinase SYK as a mediator of metastatic dissemination in zebrafish and mouse xenograft models of human prostate cancer. While SYK has not been implicated previously in this disease, we found that its expression is upregulated in human prostate cancers and associated with malignant progression. RNAi-mediated silencing prevented invasive outgrowth in vitro and bone colonization in vivo, effects that were reversed by wild-type but not kinase-dead SYK expression. In the absence of SYK expression, cell surface levels of the progression-associated adhesion receptors integrin α2β1 and CD44 were diminished. RNAi-mediated silencing of α2β1 phenocopied SYK depletion in vitro and in vivo, suggesting an effector role for α2β1 in this setting. Notably, pharmacological inhibitors of SYK kinase currently in Phase I-II trials for other indications interfered similarly with the invasive growth and dissemination of prostate cancer cells. Our findings offer a mechanistic rationale to reposition SYK kinase inhibitors for evaluation in patients with metastatic prostate cancer.

Citation Format: Erik Danen. Syk is a candidate kinase target for the treatment of advanced prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4117. doi:10.1158/1538-7445.AM2015-4117
Abstract 412: Phytochemical pterostilbene suppresses lung cancer stem cell generation via modulating tumor-associated macrophages
Authors: Huang Wen-Chien
Published: August 2015

Tumor associated macrophages have been shown to play key roles in tumor progression in different cancer types including lung. Here we investigated the role of M2-tumor associated macrophages (TAMs) in the generation of lung cancer stem cells (LCSCs) and the potential of modulating TAMs to inhibit the generation of LCSCs. Elevated Muc1 expression has been reported in inflammatory lung macrophages and associated with lung cancer development. We first found that Muc1 is overexpressed in lung cancer patients and associated with poor survival rates from public database; importantly, we showed that when co-cultured with TAMs, the level of Muc1 along with stemness genes significantly increased in lung cancer cells. Pterostilbene dose-dependently suppressed self-renewal ability in TAMs-cocultured lung cancer cells via downregulating Muc1, NF-kB, CD133, β-catenin and Sox2 expression. Subsequently, we demonstrated Muc1-silenced TAMs exhibited a significantly lower ability to promote the generation of LCSCs and a decreased level of NF-kB, CD133 and Sox2. Collectively, we demonstrated that Muc1 played an important role in TAMs-induced LCSC generation and pterostilbene treatment inhibited this phenomenon. Modulation of TAMs using pterostilbene may be of future clinical use for treating lung cancer patients.

Note: This abstract was not presented at the meeting.

Citation Format: Wen-Chien Huang. Phytochemical pterostilbene suppresses lung cancer stem cell generation via modulating tumor-associated macrophages. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 412. doi:10.1158/1538-7445.AM2015-412
Abstract 4124: Potent anti-tumor and metastatic breast cancer efficacy of bevacizumab with CRLX101, an investigational chemotherapy nanoparticle-drug conjugate that secondarily suppresses HIF-1α
Authors: Pham Elizabeth , Lee Christina R. , Xu Ping , Man Shan , Yin Melissa , Foster F. Stuart , Peters Christian G. , Lazarus Douglas , Eliasof Scott , Kerbel Robert S.
Published: August 2015

Despite the approval of seven different VEGF-pathway targeting agents, such as bevacizumab, for ten different cancer types, VEGF inhibition has shown only modest survival benefits - especially in breast cancer. One hypothesis for this is the adaptive resistance that emerges, such as increased tumor hypoxia and elevated hypoxia-inducible factor 1α (HIF-1α), which up-regulates genes causing tumor angiogenesis, resistance and metastasis. Here we evaluated bevacizumab paired with a potent cytotoxic investigational drug called CRLX101, a nanoparticle-drug conjugate containing the payload camptothecin that secondarily suppresses HIF-1α. In a preclinical mouse model of primary human breast tumor xenografts grown in the mammary fat pad after cell-line implantation, CRLX101 monotherapy was highly efficacious. More importantly, CRLX101 with bevacizumab resulted in dramatic primary tumor shrinkages and greatly improved mice survival, despite bevacizumab alone having no activity in this model. This potent anti-tumor efficacy was further confirmed in a patient-derived xenograft (PDX) model, where again CRLX101 and bevacizumab led to obvious shrinkage of established primary tumors. HIF-1α suppression was confirmed by immunohistochemistry while changes in tumor hypoxia and perfusion were evaluated using photoacoustic imaging and contrast-enhanced ultrasound, respectively. To better reflect the clinical treatment setting, the combination was next evaluated in our preclinical model of post-surgical, overt metastatic disease. Both CRLX101 monotherapy and CRLX101 in combination with bevacizumab showed shrinkage of existing metastatic masses and prevented the emergence of new metastases. In conclusion, we showed that pairing an anti-angiogenic agent with a potent chemotherapy backbone that is able to suppress HIF-1α up-regulation induced by anti-angiogenic therapy greatly improve efficacy in both primary and metastatic breast cancer models. The data from these preclinical experiments demonstrate that further research of the combination of bevacizumab and other anti-angiogenic drugs with CRLX101 is warranted in solid tumors.

Citation Format: Elizabeth Pham, Christina R. Lee, Ping Xu, Shan Man, Melissa Yin, F. Stuart Foster, Christian G. Peters, Douglas Lazarus, Scott Eliasof, Robert S. Kerbel. Potent anti-tumor and metastatic breast cancer efficacy of bevacizumab with CRLX101, an investigational chemotherapy nanoparticle-drug conjugate that secondarily suppresses HIF-1α. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4124. doi:10.1158/1538-7445.AM2015-4124
Abstract 4141: Hypoxia-induced transition from collective to amoeboid single cell dissemination in epithelial cancer cells
Authors: Lehmann Steffi , te Boekhorst Veronika A M , Odenthal Julia , Jiang Liying , van Helvert Sjoerd , Friedl Peter
Published: August 2015

Tumor hypoxia, by elevating hypoxia-inducible factors (HIFs), is an established inducer of epithelial-to-mesenchymal transition (EMT) and subsequent cancer cell invasion and metastasis. Using epithelial carcinoma spheroids in 3D fibrillar collagen, we characterized the invasion patterns as well as cellular and molecular mechanisms of hypoxia-induced cancer cell migration modes. While epithelial cancer cells show collective invasion under normoxic conditions, hypoxia or pharmacological stabilization of HIF-1 using the prolyl hydroxylase inhibitor dimethyloxalylglycine (DMOG) induced EMT-like detachment and migration of single cells. Besides mesenchymal movement, most epithelial cells converted to amoeboid migration with characteristic actin-rich filopodal or distinctive blebby protrusions towards the direction of migration. Whereas mesenchymal migrating cells moved with low velocities in a directionally persistent manner, amoeboid migrating cells generated a broad spectrum of low to high velocities, but with less persistent invasion paths. Sub-cellular molecular analysis showed typical amoeboid features particularly in hypoxic blebby single cell migration, including low to lacking collagen degradation along the migration path and insensitivity to broad-spectrum matrix metalloproteinase (MMP)-inhibitor GM6001, non-focalized cortical actin cytoskeleton within blebs that interacted with collagen structures and low-beta1 integrin expression with lack of integrin focalization. Thus, tumor hypoxia induces a diversity of single-cancer cell invasion modes, including blebby amoeboid migration, thereby enhancing predominantly MMP- and integrin-independent amoeboid dissemination in parallel to EMT induction.

Citation Format: Steffi Lehmann, Veronika A M te Boekhorst, Julia Odenthal, Liying Jiang, Sjoerd van Helvert, Peter Friedl. Hypoxia-induced transition from collective to amoeboid single cell dissemination in epithelial cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4141. doi:10.1158/1538-7445.AM2015-4141
Abstract 4166: Targeting NF-κB by the curcumin and its analogs EF-31 and UBS-109 decreases growth and angiogenesis of colon cancer
Authors: Nagaraju Ganji Purnachandra , Shoji Mamoru , Rayes Bassel El
Published: August 2015

Purpose/Objective:

NF-κB plays an essential role in cancer cell growth and metastasis by stimulating angiogenesis. Curcumin decreases the activity of several oncogenic transcriptional factors including NF-κB and HIF-1α, thus we investigated whether curcumin and its analogs EF-31 and UBS-109, could disrupt angiogenesis using colorectal cancer cells (CRC).

Methods:

HCT-116 and HT-29 cells were used in these experiments. HUVEC tube formation assay, Matrigel plug assay, Western blotting, and VEGF activity assay were carried out to determine the curcumin, EF-31 and UBS-109 role in angiogenesis. A subcutaneous xenograft mouse model was used to evaluate the in vivo effects of curcumin analogues.

Results:

Conditioned medium from HCT-116 or H-T29 cells exposed to curcumin, EF-31 and UBS-109 in vitro significantly blocked HUVEC tube assembly in comparison to control. In vivo, EF-31 and UBS-109 blocked the vascularization of subcutaneous matrigel plugs and the growth of CRC xenografts. We observed significant inhibition of VEGF synthesis and secretion in both colon cell lines treated with curcumin, EF-31 and UBS-109 in concert with the loss of HIF-1α expression, of which transcriptionally regulated by NF-κB. Similar effects were observed in tumors from animals treated with EF-31 and UBS-109. Further, EF-31 and UBS-109 treatment significantly decreased the tumor growth compared to untreated tumors. These results suggesting that curcumin, EF-31 and UBS-109 inhibits VEGF production in part through the degradation of HIF-1α and increased the cytoplasmic accumulation of NF-κB.

Conclusion:

Taken together, destabilization of HIF-1α and inhibition of NF-κB from cytoplasm to nuclear translocation may be important contributing factors to the antiangiogenic action of curcumin, EF-31 and UBS-109 in CRC.

Note: This abstract was not presented at the meeting.

Citation Format: Ganji Purnachandra Nagaraju, Mamoru Shoji, Bassel El Rayes. Targeting NF-κB by the curcumin and its analogs EF-31 and UBS-109 decreases growth and angiogenesis of colon cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4166. doi:10.1158/1538-7445.AM2015-4166
Abstract 4176: The homeobox gene DLX4 stimulates inducible nitric oxide synthase-mediated angiogenesis in ovarian cancer
Authors: Trinh Bon Q. , Ko Song Yi , Haria Dhwani , Barengo Nicolas , Naora Honami
Published: August 2015

Increasing evidence indicates that the free radical gas nitric oxide plays an important role in stimulating angiogenesis. However, the mechanisms that control nitric oxide-mediated angiogenesis in tumors are poorly understood. We previously identified that DLX4, a transcription factor encoded by a homeobox gene, stimulates ovarian tumor progression and correlates with poor outcomes of ovarian cancer patients. In this study, we identified that high DLX4 expression in ovarian cancer specimens is strongly associated with elevated expression of inducible nitric oxide synthase (iNOS), an enzyme that generates nitric oxide. DLX4 induced iNOS expression in ovarian cancer cells in vitro and in xenograft models. We identified that DLX4 interacts with STAT1 and induces iNOS expression in a STAT1-dependent manner. In in vitro studies, inhibition of iNOS abrogated the stimulatory effects of DLX4 on nitric oxide production, vascular endothelial growth factor expression and endothelial cell growth. Furthermore, inhibition of iNOS abrogated the stimulatory effects of DLX4 on tumor microvessel density and ascites formation in ovarian cancer xenograft models. Collectively, our findings indicate that DLX4 contributes to ovarian tumor progression in part by promoting nitric oxide-mediated angiogenesis. This is the first report that functionally links the aberrant expression of a developmental patterning gene in tumors with free radical gas generation.

Note: This abstract was not presented at the meeting.

Citation Format: Bon Q. Trinh, Song Yi Ko, Dhwani Haria, Nicolas Barengo, Honami Naora. The homeobox gene DLX4 stimulates inducible nitric oxide synthase-mediated angiogenesis in ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4176. doi:10.1158/1538-7445.AM2015-4176
Abstract 4198: mTORC2 directs breast morphogenesis through Rictor-dependent PKCα/Rac1 signaling independent of Akt
Authors: Brantley-Sieders Dana M. , Morrison Meghan M. , Hicks Donna J. , Cook Rebecca S.
Published: August 2015

Akt phosphorylation is a major driver of cell survival, motility, and proliferation in development and disease, causing increased interest in upstream regulators of Akt like mTOR complex 2 (mTORC2). We used genetic disruption of Rictor to impair mTORC2 activity in mouse mammary epithelia, which decreased Akt phosphorylation, ductal length, secondary branching, cell motility, and cell survival. These effects were recapitulated with a pharmacological dual inhibitor of mTORC1/mTORC2, but not upon genetic disruption of mTORC1 function via Raptor knock-out. Surprisingly, Akt re-activation was insufficient to rescue survival, branching, or motility of mTORC2-impaired mammary epithelial cells (MECs). However, activation of the mTORC2 substrate protein kinase C (PKC)-α fully rescued branching, invasion, and survival of MECs after genetic or pharmacological mTORC2 inhibition. PKCα-mediated signaling through the small GTPase Rac1 was necessary for mTORC2-dependent mammary morphogenesis, revealing a novel role for Rictor/mTORC2 in survival and motility of untransformed MECs through an Akt-independent, PKCα/Rac1-dependent mechanism. Ongoing analyses of mammary specific Rictor-deletion in genetically engineered mouse models of breast cancer support a key role for mTORC2 in tumor progression and metastasis.

Citation Format: Dana M. Brantley-Sieders, Meghan M. Morrison, Donna J. Hicks, Rebecca S. Cook. mTORC2 directs breast morphogenesis through Rictor-dependent PKCα/Rac1 signaling independent of Akt. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4198. doi:10.1158/1538-7445.AM2015-4198
Abstract 4203: Retinoic acid signal and annexins: A vicious circle of breast tumorigenesis
Authors: Rossetti Stefano , Bshara Wiam , Reiners Johanna , Corlazzoli Francesca , Miller Austin , Sacchi Nicoletta
Published: August 2015

Physiological retinoic acid (RA), the bioactive derivative of Vitamin A, is a signal necessary for epithelial cell morphogenesis. During acinar morphogenesis of normal breast epithelial cells in three dimensional (3D) culture, physiological RA activates in a spatiotemporal fashion both genomic and non-genomic RA receptor alpha (RARA) signalings, thus leading to growth-arrested acini with a lumen lined by a layer of polarized cells. In contrast, lack of activation of genomic RARA by physiological RA results in the formation of 3D amorphous acini without lumen and with uncontrolled proliferation of the luminal cells. This is similar to what is observed in early in situ breast cancer lesions, such as ductal carcinoma in situ (DCIS). Different factors that, directly or indirectly, affect genomic RARA in normal breast epithelial cells and, consequently, the morphogenetic action of RA signal, lead to deregulation of members of the Annexin family, including Annexin A8 (ANXA8). Interestingly, upregulation of ANXA8 is sufficient to affect the genomic RARA-mediated RA signaling with consequent development of 3D amorphous acini. Thus, ANXA8 upregulation consequent to functional inhibition of genomic RARA by different factors seems to reinforce through a feedback loop the extent of functional inhibition of genomic RARA itself. It is of significance that ANXA8 upregulation in DCIS does correlate with tumor grade and stage.

Acknowledgements: Funding for this study was provided by the NCI R01 CA127614 grant, the Susan Komen Foundation, the Breast Cancer Coalition of Rochester, the Friends for an Earlier Breast Cancer Test, the Terri Brodeur Breast Cancer Foundation.

Citation Format: Stefano Rossetti, Wiam Bshara, Johanna Reiners, Francesca Corlazzoli, Austin Miller, Nicoletta Sacchi. Retinoic acid signal and annexins: A vicious circle of breast tumorigenesis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4203. doi:10.1158/1538-7445.AM2015-4203
Abstract 4213: Gene therapy for esophageal squamous cell carcinoma using SOCS-1 expressing adenoviral vector
Authors: Hara Hisashi , Nakatsuka Rie , Takahashi Tsuyoshi , Serada Satoshi , Fujimoto Minoru , Miyazaki Yasuhiro , Makino Tomoki , Kurokawa Yukinori , Yamasaki Makoto , Miyata Hiroshi , Nakajima Kiyokazu , Takiguchi Shuji , Mori Masaki , Doki Yuichiro , Naka Tetsuji
Published: August 2015

Objective Esophageal squamous cell carcinoma (ESCC) is the major histological form of oesophageal cancer in East Asian countries. Despite recent improvements in multimodality treatment, including surgery, radiotherapy and chemotherapy, the prognosis for patients with ESCC remains unsatisfactory. Therefore, development of novel therapy is urgently required. Suppressor of cytokine signaling-1 (SOCS-1) has been cloned as a negative regulator of various cytokine signaling. Recently, lines of evidences suggest that overexpression of SOCS-1 has been considered as a promising therapeutic approach for treatment of cancer. This study was aimed to evaluate the therapeutic effect of the overexpression of SOCS-1 by adenoviral vector (AdSOCS-1) against ESCC.

METHODS By WST-8 assay, cell growth inhibition via infection with various dose of AdSOCS-1 was evaluated in 11 ESCC cell lines in vitro. We also evaluated the induction of apoptosis by overexpression of SOCS-1 in vitro. To evaluate the therapeutic efficacy of AdSOCS-1, ESCC cell line (TE-8) was subcutaneously implanted into the ICR nu/nu mice. In addition, therapeutic efficacy was also assessed using human xenografts subcutaneously transplanted in imuune-deficient mice. Mice were intra-tumorally injection with AdSOCS-1 or control adenovirus vector (AdLacZ) twice a week for 4weeks.

RESULTS Among 11 ESCC cell lines, AdSOCS-1, markedly suppressed proliferation of 8 ESCC cell lines in vitro. AdSOCS-1 strongly induced apoptosis in vitro, via inhibiting JAK/STAT3 pathway. In the TE8 xenograft model, the volume of tumors after therapy in AdSOCS-1 group (1,580 ± 1,005mm3) were lower than that in control group (2,690 ± 1,309mm3). Furthermore, compared with AdLacZ, injection with AdSOCS-1 also inhibited the tumor growth of patient derived ESCC xenografts.

CONCLUSIONS Our results indicated that overexpression of SOCS-1 inhibited the progression of ESCC both in ESCC cell lines and ESCC xenograft model derived from patient. SOCS-1 can be a promising novel therapeutic approach for intra-lesional therapy in ESCC.

Citation Format: Hisashi Hara, Rie Nakatsuka, Tsuyoshi Takahashi, Satoshi Serada, Minoru Fujimoto, Yasuhiro Miyazaki, Tomoki Makino, Yukinori Kurokawa, Makoto Yamasaki, Hiroshi Miyata, Kiyokazu Nakajima, Shuji Takiguchi, Masaki Mori, Yuichiro Doki, Tetsuji Naka. Gene therapy for esophageal squamous cell carcinoma using SOCS-1 expressing adenoviral vector. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4213. doi:10.1158/1538-7445.AM2015-4213
Abstract 4219: Small G protein Rac GTPases regulate the maintenance of glioblastoma stem-like cells
Authors: Lai Yun-Ju , Tsai Jui-Cheng , Tseng Ying-Ting , Benveniste Etty N.
Published: August 2015

Glioblastoma is the most common and aggressive malignant primary brain tumor in adults. Its invasiveness and resistance to traditional therapies make it a highly recurrent malignant disease with poor prognosis. The existence of glioblastoma stem cells (GSC) may account for its invasiveness and high recurrence, so GSCs become a suitable target for developing new treatments. Rac proteins belong to the Rho small GTPase subfamily, which major functions include regulation of cell movement, proliferation, and survival. However, most of the studies focused on Rac1 but not other Rac family proteins. To investigate whether other Rac proteins, Rac2 and Rac3, can serve as new therapeutic targets for glioblastoma, especially for glioblastoma stem cells, we examined the effects of Rac1-3 on glioblastoma cells-derived tumorspheroids (glioblastoma stem-like cells). We found that Rac1-3 are important for cell proliferation and colony formation of glioblastoma stem-like cells. We also established the zebrafish xenotransplantation model to further study the effects of Rac proteins in glioblastoma, and observed that the cells expressing control scramble short-hairpin RNA sequence induced angiogenesis in the egg yolk of the fish, while the cells expressing siRacs shrank inside the fish and did not induce angiogenesis. The overall survival rates of fishes were also higher in the fishes injected with siRac cells instead of fishes with control scramble RNA cells. Furthermore, Rac proteins also involve in STAT3 and ERK activation, and regulate the GSC marker expression such as CD133, Sox2 and HIF-2α in glioblastoma stem-like cells. In conclusion, Rac proteins can serve as the potential therapeutic targets against glioblastoma and its stem cells.

Citation Format: Yun-Ju Lai, Jui-Cheng Tsai, Ying-Ting Tseng, Etty N. Benveniste. Small G protein Rac GTPases regulate the maintenance of glioblastoma stem-like cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4219. doi:10.1158/1538-7445.AM2015-4219