bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4882: Differential BMP4 and GREM1 protein expression in uterine leiomyosarcoma and leiomyoma.
Authors: Garcia Natalia , Souza Faila Catarina , Cunha Isabela Werneck , Soares Fernando Augusto , Maciel Gustavo Arantes Rosa , Baracat Edmund Chada , Carvalho Katia Candido
Published: August 2014

Background:

Uterine leiomyosarcoma (ULMS) and leiomyoma (ULM) are smooth muscle tumors with distinct clinical behavior. Little is known about the factors that influence these tumors biology. Differential diagnosis among low grade ULMS and the several clinical forms of ULM is a challenge both in laboratory and pathological routine. Thus, the identification of new molecular markers can help in the differential diagnosis between ULM from ULMS and clinical management. Our aim was to evaluate expression of bone morphogenetic protein - 4 (BMP-4) and Gremlin-1 (GREM1) in uterine leiomyosarcoma and leiomyoma (including leiomyoma with atypia) using immunohistochemistry. Method: 57 patients with ULMS and 30 with ULM, among them

10 ULM with atypia (ULMA) were select. The tissues were used in tissue microarray construction. Immunohistochemistry reaction was performed with monoclonal antibody against BMP-4 and GREM-1 and evaluated using semi-quantitative method.

Results: BMP-4 was positive in 43% of the ULMS, 5% ULM and 80% ULMA, respectively. GREM-1 was positive in 67% of the ULMS, 20% ULM and 10% ULMA. BMP-4 is a potent growth factor that is involved in many important biological processes. Gremlin-1 can specifically bind to BMP-4 precursor protein inside cells, which prevents the production and secretion of mature BMP-4. This regulation determines BMP-4 biological effects on cells in the local microenvironment.

However, the molecular mechanism of GREM-1/BMP-4 interaction remains unexplored.

Conclusion: Ours preliminary results showed that expression of BMP-4 and GREM-1 play an important role in uterine smooth tumors, in while atypical leiomyomas presented higher levels of BMP-4 protein expression and lower levels of GREM-1. However, the role of these proteins interactions must be clarified.

Citation Format: Natalia Garcia, Faila Catarina Souza, Isabela Werneck Cunha, Fernando Augusto Soares, Gustavo Arantes Rosa Maciel, Edmund Chada Baracat, Katia Candido Carvalho. Differential BMP4 and GREM1 protein expression in uterine leiomyosarcoma and leiomyoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4882. doi:10.1158/1538-7445.AM2013-4882
Abstract 4886: Caffeine normalizes breast stromal fibroblasts and suppresses their pro-carcinogenic effects.
Authors: Al Ansari Mysoon M. , Aboussekhra Abdelilah
Published: August 2014

Breast cancer is the leading cause of morbidity and second-leading cause of death in women worldwide. Breast stromal fibroblasts, the most abundant and the most reactive cells of the tumor stroma, actively promote tumor growth, invasion, migration, angiogenesis and metastasis through elevated secretion of several factors including SDF1, MMP-2 and vascular endothelial growth factor A (VEGF-A). These secretions are under the control of several tumor suppressor genes such as p16, p53 and CAV-1, which were fond to be down-regulated in most active fibroblasts. Therefore, our major aim in this study was to study the potential use of caffeine to up-regulate these tumor suppressor genes and hence reduces the secretion of these cancer-promoting factors. We have shown that low doses of caffeine up-regulate the tumor suppressor proteins p16, p21, p53 and CAV-1 in breast stromal fibroblasts. Consequently, the expression and secretion of MMP-2 and VEGF-A was reduced following caffeine treatment. Moreover, caffeine reduced the expression of SDF-1, TGF-β and α-SMA, three important markers of active fibroblast, suggesting that caffeine has the ability of “normalizing” stromal fibroblasts. To further confirm this, we have shown that caffeine suppresses stromal fibroblast-related enhancement of invasion/migration of breast cancer cells. Importantly, this effect was mediated through caffeine-dependent inactivation of the two major invasion/migration protein kinases Akt and Erk, through up-regulating PTEN in breast stromal fibroblasts. Furthermore, caffeine suppressed the expression/secretion of VEGF-A in breast stromal fibroblasts and their paracrine enhancement of angiogenesis in vitro. This effect was mediated through inhibition of the VEGF-A activator HIF-1α. Therefore, we have clearly shown here that caffeine, a natural and pharmacologically safe product, has the potential to normalize breast stromal fibroblasts and consequently suppresses their paracrine procarcinogenic effects.

Citation Format: Mysoon M. Al Ansari, Abdelilah Aboussekhra. Caffeine normalizes breast stromal fibroblasts and suppresses their pro-carcinogenic effects. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4886. doi:10.1158/1538-7445.AM2013-4886
Abstract 4889: Alteration of cancer stem cell-like phenotype by histone deacetylase inhibitors in squamous cell carcinoma of the head and neck.
Authors: Sakakura Koichi , Murata Takaaki , Chikamatsu Kazuaki
Published: August 2014

Recent progression in the understanding of stem cell biology has greatly facilitated the identification and characterization of cancer stem cells (CSCs) from various tumors. In squamous cell carcinoma of the head and neck (SCCHN), various cell surface markers, including CD44, CD133 and ALDH1, have been identified as the potential markers to isolate CSCs. Evidence has accumulated indicating that conventional cancer treatments are potentially ineffective against CSCs.

Histone deacetylase inhibitors (HDACi) have multiple biologic effects consequent to alteration in patterns of acetylation of histones and are promising new group of anticancer agents. In this study, we investigate the effects of two HDACi, suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA) on two CD44+ cancer stem-like cell lines from SCCHN cultured in serum-free medium containing epidermal growth factor and basic fibroblast growth factor. SAHA and TSA inhibited the growth of SCCHN cell lines in a dose dependent manner as measured by MTS assays. Moreover, SAHA and TSA induced G2/M cell cycle arrest and apoptosis in these SCCHN cell lines. Interestingly, the expression of cancer stem cell markers, CD44 and ABCG2 on SCCHN cell lines were decreased by SAHA or TSA treatment. HDACi also decreased the mRNA expression levels of stemness-related genes (Notch and Nanog) and TGF-β. As expected, HDACi markedly increased the expression of E-cadherin. In addition, the combination of HDACi and chemotherapeutic agents, including cisplatin and docetaxel had a synergistic effect on SCCHN cell lines.

Taken together, our data indicate that HDACi not only inhibit the growth of SCCHN cell lines by inducing apoptosis and cell cycle arrest, but also alter stem-like properties of the SCCHN cells, raising the possibility that HDACi may have therapeutic potentials for cancer stem cells of SCCHN.

Citation Format: Koichi Sakakura, Takaaki Murata, Kazuaki Chikamatsu. Alteration of cancer stem cell-like phenotype by histone deacetylase inhibitors in squamous cell carcinoma of the head and neck. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4889. doi:10.1158/1538-7445.AM2013-4889
Abstract 4892: Hypoxia enhances tumor vascularization by endothelial differentiation of endometrial cancer stem cells.
Authors: Nakamura Mitsuhiro , Zhang Xiuzhi , Takakura Masahiro , Maida Yoshiko , Mizumoto Yasunari , Bono Yukiko , Sasagawa Toshiyuki , Kyo Satoru
Published: August 2014

Emerging evidence has shown that a small subpopulation of cancer cells plays critical roles in tumorigenesis, establishing the cancer stem cells (CSCs) theory. CSCs have properties of tumorigenesis, self-renewal and multilineage differentiation. Previous our study demonstrated that CD133+ enodometrial cancer cells showed tumorigenic and self-renewal ability, suggesting that CD133 was a potential CSC marker in endometrial cancer. In this study, we focused on multilineage differentiation and investigated an ability of endothelial differentiation in endometrial CSCs. Immunohistochemistry of subcutaneous xenografts showed that human endometrial tumors contained human vessels labeled by human-specific anti-CD31 and vWF antibodies. Endothelial tube formation assay (in vitro angiogenesis) revealed that isolated CD133+ endometrial cancer cells could show tube formation while CD133- cells could not. CD133+ cells expressed CD31 and VEGFR-1 higher than CD133- cells. In some cell types of endometrial cancer cells, flow cytometric analysis showed expression of CD31 was high ratio under hypoxia compared to normoxia. Furthermore, in vitro angiogenesis assay demonstrated hypoxic condition could promote and keep tube formation in CD133+ cells, but not CD133- cells. These results suggest that CSCs have potential of endothelial differentiation and hypoxia enhances endothelial differentiation of CSCs. These findings shed light on the establishment of new target therapy for endometrial cancer.

Citation Format: Mitsuhiro Nakamura, Xiuzhi Zhang, Masahiro Takakura, Yoshiko Maida, Yasunari Mizumoto, Yukiko Bono, Toshiyuki Sasagawa, Satoru Kyo. Hypoxia enhances tumor vascularization by endothelial differentiation of endometrial cancer stem cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4892. doi:10.1158/1538-7445.AM2013-4892
Abstract 4895: A cancer stem cell instigator pathway revealed by transcriptomics, stem cell mutagenesis, and in-vivo tumor initiation.
Authors: Krtolica Ana , Glanville Jacob , Giritharan Gnanaratnam , Caceres Eduardo , Canino Erica , Kim Kyung-Ah
Published: August 2014

We have developed a multi-stage Cancer Stem Cell (CSC) model that recapitulates the natural process of carcinogenesis. Isogenic human embryonic stem cells (ESCs) exposed to non-biased mutagens were found to undergo rare spontaneous CSC transformation. Progenitor induced CSC (iCSC) clones exhibited classical CSC/SC marker expression, tumorsphere formation, resistance to common chemotherapeutic agents, and a capacity to form serially transplantable tumors in immunocompromised animals. A subset of progenitor clones formed tumors that took on a glioma-like morphology and produced more highly drug resistant mature CSCs that exhibited phenotypic characteristics of the primary patient glioma CSCs. Computational comparison to expression profiles of 313 human tumor lines confirmed that the mature CSCs had adopted a glioma-like expression profile.

An integrated molecular model of the instigator pathway was assessed by comprehensive RNASeq transcriptomics, tandem MS proteomics, microRNA profiling, and mutagen-induced molecular polymorphisms. Progenitor iCSCs were found to have an ESC expression phenotype, significantly differing in the expression of only 32 genes, with some bearing direct evidence of mutagenesis in the expressed transcript. The instigator genes formed a proto-oncology seed pathway that was expanded by progressive expression changes to a more classical oncology profile in the glioma-like tumors and mature iCSCs derived in vivo from the progenitor iCSC. Classical oncology targets evident in the late-stage tumor model were absent in the progenitor iCSCs. However, computational repositioning analysis identified a limited set of existing molecules that could act directly to mitigate the progenitor pathway in the iCSCs.

Citation Format: Ana Krtolica, Jacob Glanville, Gnanaratnam Giritharan, Eduardo Caceres, Erica Canino, Kyung-Ah Kim. A cancer stem cell instigator pathway revealed by transcriptomics, stem cell mutagenesis, and in-vivo tumor initiation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4895. doi:10.1158/1538-7445.AM2013-4895
Abstract 4898: Association of CD44 expression and ALDH1 activity in thyroid cancer.
Authors: Okada Toshihiro
Published: August 2014

Background: Anaplastic thyroid cancer (ATC) is considered to be one of the most aggressive human malignancies, and the mean survival time (MST) after diagnosis is approximately six months, regardless of treatments. ATC is known to arise from differentiated thyroid cancers such as papillary (PTC) or follicular (FTC) cancers. The purpose of this study is to examine whether the characteristics of cancer stem cell are associated with ATC.

Materials and methods: One PTC cell line (TPC1), one FTC cell line (FTC-133), and two ATC cell lines (FRO, ACT-1) were analyzed for surface markers (CD24/CD44, CD44 variant isoform, EpCAM), and ALDH1 enzymatic activities (ALDEFLUOR) by FACS. In addition, relative mRNA expression of these molecules were determined by real-time RT-PCR.

Results: CD44s (standard form) expressions in the PTC cell line (TPC1) and the FTC cell line (FTC-133) were higher than those in the ATC cell lines (FRO and ACT-1). On the other hand, ALDH1 activities of ATC cell lines were higher than those of the PTC and the FTC cell lines. An inverse correlation between the expression of CD44s and ALDH1 activity was observed in the thyroid cancer cell lines. As for the expressions of CD44 variant forms, ACT-1 showed a higher and FRO showed a moderate expressions of CD44v6. On the other hand, either TPC1 or FTC-133 showed negative expression of CD44v6. The expressions of EpCAM in the ATC cell lines were higher than those in the differentiated cancer cell lines, and EpCAM expressions were inversely correlated with the expressions of CD44s. ATC cell lines showed higher levels of ALDH1 enzymatic activities and EpCAM expressions compared with those in the differentiated cancer cell lines. A strong positive correlation was observed between the expression of EpCAM and ALDH1 activity in the thyroid cancer cell lines. Both ALDH1 and EpCAM mRNA expressions were higher in the ATC cell lines compared with those in the differentiated cancer cell lines in the RT-PCR analyses.

Conclusion: In our present study, the expressions of CD44 and EpCAM, and ALDH1 enzymatic activity were different between the differentiated thyroid cancer cell lines and the anaplastic thyroid cancer cell lines. Our data suggest that these molecules might be involved in the development and aggressive phenotype of anaplastic thyroid cancer.

Citation Format: Toshihiro Okada. Association of CD44 expression and ALDH1 activity in thyroid cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4898. doi:10.1158/1538-7445.AM2013-4898
Abstract 4920: EcSOD overexpression inhibits the growth and invasion by affecting extracellular matrix in PC3 human prostate cancer cells.
Authors: Kim Jungim
Published: August 2014

It has been shown that EcSOD (extracellular superoxide dismutase, SOD3) can attenuate tissue damage and cancer cell invasion but so far its function in prostate cancer cells has not been completely clarified. Thus, we investigated the effect of EcSOD for cell growth and invasion in PC3 human prostate cancer cells. We stably transfected PC3 cells with pCMV-EcSOD cDNA and observed its overexpression in mRNA and protein levels through RT-PCR and Western Blot, respectively. To check out the influence for the growth rate of EcSOD, we analyzed Cell Viability and Cytotoxicity Assay as a colorimetric and fluorometric format via MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) reagent and cell-permeable polyanionic calcein acetoxymethyl (Calcein AM) and ethidium homodimer (EthD-1) dye. And we performed EcSOD Activity Assay and ELISA. Moreover, we time-dependently carried out Wound-healing Assay by monitoring the down-regulated growth rate of EcSOD overexpression PC3 cells. Furthermore, we verified low EcSOD expression compared to other types of SODs by IHC and Patients Tissue Microarray. Meanwhile, we accomplished Invasion Assay and MMP-2 and-9 Activity Assay with Zymography. Herein, it elucidated that EcSOD abrogates cell growth, proliferation, and invasion by associating with extracellular matrix in PC3 human prostate cancer cells. Taken together, these findings suggest that EcSOD can potentially have beneficial future strategy for the treatment of prostate cancer.

Citation Format: Jungim Kim. EcSOD overexpression inhibits the growth and invasion by affecting extracellular matrix in PC3 human prostate cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4920. doi:10.1158/1538-7445.AM2013-4920
Abstract 4924: Connective tissue growth factor (CTGF) mediates metastases of breast cancer stem cells.
Authors: Zhong Jing , Zhu Xiaoping , Zhao Hong , Wong Stephen Tc , Wong Stephen Tc
Published: August 2014

Background: Recent studies on various cancer types suggest that the mere acquisition of cancer stem-like cells (CSCs) phenotype is not sufficient to confer metastatic potential. Epithelial-Mesenchymal transition (EMT) has been implicated in enhancing cancer metastatic dissemination, and generating CSCs, which may be a key determinant in imparting metastatic potential to CSCs. Our goal is to determine the metastasis potential of the CSCs generated from EMT and to explore critical molecules involved in the metastatic cascade process.

Experimental design and methods: The metastatic ability of the EMT-generated-CSCs (HMLE-Ras-Snail) and the control cell line (HMLE-Ras-vector) were compared by the migration, invasion and chemotaxis assays in vitro, as well as experimental and spontaneous metastases mice models in vivo. A microarray gene profiling analysis was performed to explore signaling molecules involved in the EMT-CSCs-metastasis. Functional assays were used to verify the identified molecule in vitro and in vivo.

Results: HMLE-Ras-Snail cells showed significant high migration, invasive behaviors, especially under the different organ protein as chemo-attractants (lung, brain and liver). Experimental lung and brain metastasis mice study showed a significant enhancement of tumor extravasation and outgrowth of HMLE-Ras-Snail cells compared with the control cells. Spontaneous metastases mice studies showed that 7 out of 9 mice developed lung metastasis, and 2 out of 9 with brain metastasis for the HMLE-Ras-Snail model, while none of the HMLE-Ras-vector cell-injected mice were detected with metastases. Two-photon live animal imaging also showed enhanced single cell adhesion and movement in the lung or brain micro-vessels in the HMLE-Ras-Snail cell-injected mice. The differential gene expression analyses and western blot indicated that the CTGF is up-regulated in the EMT-generated-CSCs. Knockdown of CTGF in the HMLE-Ras-Snail cells not only enhanced the expression of epithelial marker and decreased the mesenchymal marker, but also decreased the in vitro proliferation, migration, invasion, mammosphere formation and in vivo lung metastases.

Conclusions: CTGF may play an important role in breast cancer metastasis, with enhancing cell motility, invasiveness and also give cell self-renewal stem cell-like characteristic to facilitate EMT-CSCs-Metastasis.

Citation Format: Jing Zhong, Xiaoping Zhu, Hong Zhao, Stephen Tc Wong, Stephen Tc Wong. Connective tissue growth factor (CTGF) mediates metastases of breast cancer stem cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4924. doi:10.1158/1538-7445.AM2013-4924

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 4930: A commensal relationship between tumor cell subpopulations promotes collective invasion.
Authors: Pearson Gray , Prechtl Amanda , Westcott Jill , Dang Tuyen , Maine Erin
Published: August 2014

The invasion of tumor cells out of ductal epithelium is a poorly understood process that dramatically increases the odds of patient death. We have defined a new non cell-autonomous control mechanism for neoplastic invasion that trigger tumors to switch from a benign to a malignant stage of growth. Using high resolution live-imaging and functional studies we show that an epigenetically distinct and autonomously invasive subpopulation of tumor cells induces the invasion of a large bulk population of autonomously noninvasive tumor cells by adopting migratory principles observed during sprouting angiogenesis. The molecular dissection of this cooperative interaction revealed a new “invasion signature” of 29 genes that is distinct from traditional epithelial-to-mesenchymal transition markers. Patients expressing this invasion signature had a worse clinical outcome, which suggests that this commensal relationship between tumor cell subpopulations contributes to tumor progression. Functional analysis showed that multiple components of the invasion signature were specifically required for the cooperative induction of invasion, but not cell motility, thus revealing new roles for these genes as non-cell autonomous regulators of invasion. These results are of broad interest because they are the first demonstration of a commensal relationship between tumor cell subpopulations during the induction of invasion. Further, these findings establish a mechanistic underpinning that obviates the notion that the exclusive role of heterogeneity in tumors is to act as a source for unique traits that can be selected for and expanded to improve the cell autonomous fitness of neoplastic cell populations. Thus, our results support a paradigm shift towards identifying both the cell autonomous and the non cell-autonomous regulatory mechanisms of cell biological processes within heterogeneous tumors to understand neoplastic progression and develop new intervention modalities.

Citation Format: Gray Pearson, Amanda Prechtl, Jill Westcott, Tuyen Dang, Erin Maine. A commensal relationship between tumor cell subpopulations promotes collective invasion. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4930. doi:10.1158/1538-7445.AM2013-4930

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 4938: Free β-subunit of human chorionic gonadotropin stimulates choriocarcinoma cell invasion independent of LH/hCG receptor.
Authors: Lee Cheuk-Lun , Chiu Philip CN , Hautala Laura , Yeung William SB , Stenman Ulf-Håkan , Koistinen Hannu
Published: August 2014

Human chorionic gonadotropin (hCG) is a heterodimer consisting of an α- and a β-subunit (hCGα and hCGβ) that are non-covalently linked. Intact hCG, but not free subunits, bind to the LH/hCG receptor. Expression of hCG and hCGβ has been observed in several cancers. Most trophoblastic tumors of placental and germ cell origin produce hCG, while many non-trophoblastic tumors, including bladder, renal and gastrointestinal cancers, often produce hCGβ, and increased serum concentrations of these are associated with adverse prognosis. hCG has been found to stimulate trophoblast invasion. The stimulatory activity has especially been ascribed to a hyperglycosylated form of hCG (hCG-h) expressed in early pregnancy. hCG-h is also a major form of hCG produced by choriocarcinoma and by testicular cancers, although tumor-derived hCG-h is often glycosylated differently than that produced by the placenta. We aimed to compare different forms of hCG in their stimulatory activities on the invasion of JEG-3 choriocarcinoma cells. Various forms of hCG and hCGβ were purified from urine of one patient with nonseminomatous testicular cancer, one with invasive molar disease, and pregnant women. Both hCG and hCGβ, and their hyperglycosylated forms stimulated the invasion of JEG-3 cells. However, cancer-derived hCG-h was more effective than “regular” hCG in stimulating the invasion. Down-regulation of the LH/hCG receptor by RNA-interference did not significantly reduce the effect of hCGβ and hCG on cell invasion. Increased invasion was associated with increased activity of MMP-2, MMP-9 and uPA in conditioned culture medium from JEG-3 cells. Our findings suggest that hCG and hCGβ stimulates the invasion of choriocarcinoma cells independent of the classical LH/hCG-receptor.

Citation Format: Cheuk-Lun Lee, Philip CN Chiu, Laura Hautala, William SB Yeung, Ulf-Håkan Stenman, Hannu Koistinen. Free β-subunit of human chorionic gonadotropin stimulates choriocarcinoma cell invasion independent of LH/hCG receptor. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4938. doi:10.1158/1538-7445.AM2013-4938
Abstract 4940: Prognostic significance of Fbw7 in human melanoma and its role in cell migration.
Authors: Cheng Yabin
Published: August 2014

The E3 ubiquitin ligase Fbw7 (F-box and WD repeat domain-containing 7) is broadly considered as a tumor suppressor because of its role in turnover of several well-known onco-proteins. However, the role of Fbw7 in melanomagenesis is not clear. To investigate the expression profile and biological functions of Fbw7 in melanoma, we examined Fbw7 expression level using melanoma tissue microarray and immunohistochemistry. Our data showed that Fbw7 expression is significantly reduced in primary melanoma compared with dysplastic nevi (P = 0.020) and further reduced in metastatic melanoma compared with primary melanoma (P = 0.011). Furthermore, we observed a strong correlation between negative Fbw7 expression and a worse 5-year survival of melanoma patients (P = 0.015). We also found that both Fbw7 protein and mRNA expression was significantly reduced in 9 melanoma cell lines compared with normal melanocytes. Moreover, our in vitro studies showed a remarkable increase of cell migration and stress fibre formation in Fbw7 knockdown cells, and treatment of selective MEK inhibitor abrogated Fbw7α knockdown induced melanoma cell migration. Taken together, our findings indicate that Fbw7 plays an important role in melanoma progression, and Fbw7 inhibits melanoma cell migration through MAPK-ERK signalling pathway and may serve as a prognostic marker.

Citation Format: Yabin Cheng. Prognostic significance of Fbw7 in human melanoma and its role in cell migration. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4940. doi:10.1158/1538-7445.AM2013-4940
Abstract 4948: Pirfenidone as a potential therapeutic treatment for CAFs and cancer cells in NSCLC.
Authors: Mediavilla-Varela Melanie , Luddy Kimberly , Noyes David , Boateng Kingsley , Antonia Scott
Published: August 2014

Lung cancer is the leading cause of cancer death in the United States. Due to limited efficacy of current conventional chemotherapy, the majority of patients face poor prognosis and eventually succumb the disease. Until recently, the main focus in cancer research has been targeting the neoplastic cell. However, the importance of the tumor microenvironment, including cancer associated fibroblasts (CAFs), in cancer progression is now clear and targeting both, the neoplastic cell as well as the CAF, is being recognized as an important therapeutic approach. We have recently discovered that pirfenidone might be the drug to target these cells. Pirfenidone is a small molecule that has been shown to decrease fibrosis in a variety of fibrotic diseases. The exact mechanism responsible for its anti-fibrotic effects remains to be elucidated. Our hypothesis is that pirfenidone (by targeting the CAFs) in combination with standard chemotherapy (by targeting the cancer cells) will act synergistically and proffer a more potent therapeutic strategy for non-small cell lung cancer (NSCLC). Our studies show that in the presence of pirfenidone NSCLC associated CAF viability decreases in vitro. Furthermore, pirfenidone was able to induce apoptotic cell death as well as cell cycle arrest in NSCLC associated CAFs. In addition, we were able to observe that CAFs treated with pirfenidone decreased active TGFβ when compared to the control. Moreover, in a spheroid model, pirfenidone was able to affect the crosstalk between the cancer cells and CAFs leading to increased apoptosis and decreased viability. Currently, pirfenidone is being used in Phase II and III clinical trials for idiopathic pulmonary fibrosis. Our lab is the first one to recognize the potential of pirfenidone as a potential treatment of NSCLC.

Citation Format: Melanie Mediavilla-Varela, Kimberly Luddy, David Noyes, Kingsley Boateng, Scott Antonia. Pirfenidone as a potential therapeutic treatment for CAFs and cancer cells in NSCLC. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4948. doi:10.1158/1538-7445.AM2013-4948
Abstract 4979: Multidimensional crosstalk regulates myeloid cell hyperplasia, immune escape, and tumor progression.
Authors: Younos Ibrahim H. , Dafferner Alicia J. , Britton Holly , Talmadge James E.
Published: August 2014

Myeloid-derived suppressor cells (MDSCs) encompass a heterogeneous class of cells in different maturation states that proliferate and accumulate in tumors, secondary lymphoid organs and some epithelial organs during tumor growth. Tumor secretion of growth factors and chemokines regulate myeloid cell proliferation, apoptosis, differentiation, circulation and biodistribution both locally and systemically. There is a reciprocal interaction that occurs between tumor and myeloid cells, which can facilitate tumor growth and metastasis and myeloid cell proliferation and survival via unique and tumor specific arrays of growth factors and chemokines. The tumor microenvironment, a complex, highly dynamic environment composed of host-derived MDSCs, endothelial cells, and fibroblasts; contributes to the microenvironmental crosstalk regulating host immunity and tumor progression. However, the macroenvironment is also a critical to myeloid cell expansion, tumor invasion and immune escape and tumor progression. The primary site of MDSC expansion and immune suppression is splenic extramedullary hematopoiesis, which is regulated by growth factors secreted by the distant primary tumor cells. Similarly, regulation of tumor infiltration by myeloid cells is by tumor secretion of CCL2; however, this occurs at the macroenvironmental level as CCL2/CCR2 blockade inhibits medullary myeloid cell mobilization and recruitment from secondary lymphoid organs and not at the tumor. Further, regulatory crosstalk is bidirectional with tumor-secreted factors differentially upregulating myeloid and lymphoid cell growth factors and enzymes (G-CSF, CXCL1, CCL2, arginase) by medullary myeloid cells and splenic lymphocytes. In tumor bearing, mice the tumor-secreted growth factors support hematopoietic stem/progenitor cell proliferation, limit their apoptosis and inhibit T-cell function. Conversely, leukocyte-secreted cytokines limit immune and hematopoietic growth factor transcript levels by tumor cells (G-CSF, IL-23, CXCL1 and NOS-2) with associated effects on tumor malignancy and leukocyte proliferation and differentiation. In summary, tumors form both local and systemic, bidirectional, regulatory loop(s) between metastatic tumor cells and MDSCs that regulates their proliferation and differentiation supporting tumor metastasis and systemic and regional T-cell suppression.

Citation Format: Ibrahim H. Younos, Alicia J. Dafferner, Holly Britton, James E. Talmadge. Multidimensional crosstalk regulates myeloid cell hyperplasia, immune escape, and tumor progression. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4979. doi:10.1158/1538-7445.AM2013-4979
Abstract 4981: PI3K/AKT/mTOR pathway activation drives expression of the immune inhibitory ligand PD-L1 in NSCLC.
Authors: Lastwika Kristin , Wilson Willie , Dennis Phillip A.
Published: August 2014

Despite the development of targeted drug therapies, lung cancer remains the leading cause of cancer-related death worldwide. Targeting immune checkpoints altered in cancer, such as the T cell inhibitory receptors programmed death 1 (PD-1) or CTLA4, represent promising new approaches to lung cancer treatment. Here we investigated the relationship of activation of the PI3K/Akt/mTOR signaling pathway and expression of the immune suppressive ligand, PD-L1, in non-small cell lung cancer (NSCLC). NSCLC cell lines with mutations in KRas, EGFR, BRaf, ALK or RET had high levels of PI3K/Akt/mTOR pathway activation as well as increased expression of PD-L1. Cell lines that lacked these mutations had low PI3K/Akt/mTOR pathway activation and less PD-L1 expression. In murine cell lines derived from tobacco carcinogen (NNK)-induced lung tumors, high levels of active Akt correlated with high PD-L1 expression. Agonists of the PI3K/Akt/mTOR pathway activation such as EGF or the carcinogen NNK, as well as knockdown of PTEN or induction of Kras induced PD-L1 expression. Conversely, treatment of high PD-L1 expressing NSCLC cell lines with inhibitors of PI3K (LY294002), AKT (triciribine) or mTOR (rapamycin) decreased PD-L1 expression. These inhibitors decreased PD-L1 protein levels, but did not alter PD-L1 mRNA. Rapamycin-mediated PD-L1 loss was partially blocked by pre-treatment with a lysosomal, but not a proteosomal inhibitor. In vivo, increased expression of PD-L1 and activation of mTOR was an early event after exposure to NNK and was blocked by rapamycin. To test the efficacy of blocking PD-1 while reducing the expression of PD-L1 in tumor tissue, rapamycin and a murine anti-PD-1 receptor antibody were administered to A/J mice bearing syngeneic lung tumor xenografts. The combination decreased the tumor growth rate to a greater degree than either agent alone and decreased mTOR pathway signaling, PD-L1 expression, and increased cleaved caspase 3. Tumor associated activated CD8+ T cells were also increased in the tumors. These data support a relationship between activation of PI3K/Akt/mTOR signaling, PD-L1 expression and the development of an immune resistant phenotype in lung cancer. Combination regimens using PI3K/Akt/mTOR inhibitors may enhance the efficacy of immune therapies targeting PD-1.

Citation Format: Kristin Lastwika, Willie Wilson, Phillip A. Dennis. PI3K/AKT/mTOR pathway activation drives expression of the immune inhibitory ligand PD-L1 in NSCLC. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4981. doi:10.1158/1538-7445.AM2013-4981
Abstract 4983: The role of bone marrow derived tumor stromal cells in intestinal tumor response to Thymidylate Synthase Inhibitors inhibitors in the ApcMin/+ mouse.
Authors: Acharya Grishma , Davis Celestia , Tisdale Nikeya , Pena Maria Marjorette O.
Published: August 2014

Historically, most anti-cancer therapies have been developed to target cancer cells. For many decades, inhibitors of the enzyme thymidylate synthase (TS), such as fluoropyrimidines, have been used in the clinical management of various cancers. However, their clinical utility has been limited by their toxicity to normal cells and acquired resistance by tumor cells. More recently, the role of non-neoplastic cells in the tumor microenvironment on tumor initiation and progression has been firmly established. These non-neoplastic cells infiltrate the tumor and together with the extracellular matrix, blood vessels, connective tissue, and secreted molecules make up the tumor stroma. These cells are thought to play a role in tumor response to therapy. While therapeutic efficacy is often measured by its impact on tumor burden, the impact of TS inhibitors on tumor stromal cells is largely unknown.

Bone marrow derived cells (BMDCs) are a major component of the tumor stroma.The goal of this project is to determine theirin mediating tumor response to systemic therapy with TS inhibitors. We hypothesize that in addition to targeting tumor cells, tumor stromal cells are also direct of TS inhibitors and thattumor response to therapy may in fact be dictated by stromal sensitivity to the therapy.To test this hypothesis, we generated chimeric wherein the chemo-sensitivity of intestinal tumor stromal cells to TS inhibitors was different from that of the tumor cells. We transplanted ApcMin/+ mice, a genetic model of intestinal tumorigenesis, with bone marrow cells that weregenetically modified to express a drug-resistant TS molecule from E. coli. We found that tumors in these mice were more resistant to a combined therapy of TS inhibitors as compared to mice transplanted with non-modified marrow. We identified examine the response of BMDCs in the tumor stroma that have previously been shown to promote intestinal tumor development, namely, myeloid derived suppressor cells (MDSCs), mast cells and T-regulatory (Treg) cells. We found that MDSCs, but not mast cells or Tregs were specifically sensitive to 5-fluorouracil (5-FU). Our data suggest that tumor response to 5-FU are at least in part mediated by MDSCs. Current studies are aimed at examining the response of other stromal components to 5-FU with the goal of developing strategies to enhance tumor sensitivity to TS inhibitors.

Citation Format: Grishma Acharya, Celestia Davis, Nikeya Tisdale, Maria Marjorette O. Pena. The role of bone marrow derived tumor stromal cells in intestinal tumor response to Thymidylate Synthase Inhibitors inhibitors in the ApcMin/+ mouse. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4983. doi:10.1158/1538-7445.AM2013-4983
Abstract 5015: Ablation of a disintegrin and metalloproteinase 10 (ADAM 10) induces significant pancreatic tumor heterogeneity and blocks cancer metastasis.
Authors: Hall Jason C. , Crawford Howard C.
Published: August 2014

Pancreatic ductal adenocarcinoma (PDA) is the 4th leading cause of cancer related death in the U.S. This disease has a poor prognosis due to late detection and rapid progression to metastasis. ADAM10 is a membrane bound metalloproteinase responsible for shedding bioactive molecules and inducing regulated intra-membrane proteolysis of cell surface proteins such as Notch. Both ADAM10 and Notch are highly expressed in patients with PDA, with the latter being implicated in PDA progression. We have found that genetic ablation of ADAM10 in the KrasG12D/+;Ptf1aCre/+ mouse PDA model altered tumor character to favor a cystic phenotype, mixed with low grade pancreatic intraepithelial neoplasia (PanIN) and PDA. Though ADAM10 knockout mice retain the ability to form locally invasive cancer, they live 50% longer than control mice, essentially to a full 2-year life span. The phenotypes we observe closely mimic Notch-2 knockout mice, consistent with ADAM10’s role as the primary Notch activating proteinase. Further examination revealed that ADAM10 knockout mice did not show significant liver metastasis compared to control, despite their local invasiveness. The mechanism through which ADAM 10 controls a cancer cell's ability to establish distant metastases will be explored.

Citation Format: Jason C. Hall, Howard C. Crawford. Ablation of a disintegrin and metalloproteinase 10 (ADAM 10) induces significant pancreatic tumor heterogeneity and blocks cancer metastasis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5015. doi:10.1158/1538-7445.AM2013-5015
Abstract 5022: Early progenitor cells but not late luminal progenitor cells preserve in invasive breast carcinoma.
Authors: Zhang Kevin J. , Liu Suling , Siegelmann-Danieli Nava , Zhang Ping L.
Published: August 2014

Background CD133 and CD117 represent markers of human breast tissue differentiation. CD133 is an early progenitor marker while CD117 represents late luminal progenitor marker (Lim, et al, Nature Medicine 2009). Morphologic expression of the two markers has not been well established in paraffin embedded tissue of human breast lesions.

Design In this study, we evaluated CD133 and C117 expression in different human breast lesions. Group 1 consisted of 15 benign breast cases (5 reduction mammoplasty cases with no significant pathology and 10 fibroadenoma or fibrocystic changes). Group 2 (malignant group 2) included 13 breast cases with invasive ductal carcinoma (IDC). Group 3 (malignant group 3) was composed of 12 BRCA-mutant breast cases but only six cases had IDC. All sections from paraffin embedded tissue were immunohistochemically stained for CD133 (AC133 clone) and CD117 (monoclonal antibody). Expression of the two markers in normal breast glands adjacent to lesions (normal controls), benign lesions (benign controls) and IDC were evaluated and positive rate was calculated.

Results Both CD133 and CD117 were expressed in normal breast glands (normal controls) of all three groups and benign breast lesions (Table 1). However, the expression of CD133 was detected in the majority of IDC lesions as compared to low positive percent of CD117 expression in both groups 2 and 3 (Table 1). Recombined tumor cases, based on the molecular luminal status, also showed 56 - 70% CD133 positivity but 0 - 20% CD117 positivity in IDC cells.

Table 1. CD133 and CD117 in benign and malignant breast lesions Group 1, total Group 2, total Group 3, total CD133+ in normal 15/15 (100%) 13/13 (100%) 12/12 (100%) CD117+ in normal 15/15 (100%) 13/13 (100%) 11/12 (91%) Group 1, Benign Lesions Group 2, Invasive cancer Group 3 Invasive cancer CD133+ in lesions 10/10 (100%) 8/13 (61%) 4/6 (67%) CD117+ in lesions 9/10 (90%) 1/13 (8%) 1/6 (17%)

Conclusions We show that normal breast glands expressed both CD133 and CD117, compatible with the presence of stem cell niche in normal breast ducts and acini. However our data suggest that in IDC, there is presence of early progenitor cells but not late luminal progenitor cells, regardless of the molecular luminal status, supporting the view that cancer stem cells exist in the invasive breast carcinoma.

Citation Format: Kevin J. Zhang, Suling Liu, Nava Siegelmann-Danieli, Ping L. Zhang. Early progenitor cells but not late luminal progenitor cells preserve in invasive breast carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5022. doi:10.1158/1538-7445.AM2013-5022
Abstract 5023: Stem cell hypothesis and function of Lgr5 in the development of colon cancer.
Authors: Hirsch Daniela D. , Barker Nick , McNeil Nicole , Hu Yue , Camps Jordi , McKinnon Katherine , Clevers Hans , Ried Thomas , Gaiser Timo
Published: August 2014

Similar to normal colonic epithelium, colorectal carcinomas (CRC) comprise subpopulations of cells with stem-like properties. Leucine-rich-repeat-containing G-protein-coupled receptor 5 (Lgr5) is associated with these stem cells in normal colonic epithelium and CRC. Here, we analyzed the functional and molecular consequences of shRNA-mediated silencing of Lgr5 in CRC cell lines SW480 and HT-29. Additionally, we exposed Lgr5-EGFP-IRES-Cre-ERT2 mice to azoxymethane/dextrane sodium sulfate (AOM/DSS) which induces inflammation-driven colon tumors. Tumors were then flow-sorted into Lgr5 high and low epithelial cell fractions and molecularly characterized using gene expression profiling and array comparative genomic hybridization. Silencing of Lgr5 in SW480 cells resulted in a depletion of the spheroid cell fraction, yet did not affect the adherently growing cell population. It also reduced proliferation, migration, and colony formation in vitro as well as tumorigenicity in vivo, consistent with a down-regulation of Notch signaling. Spheroid cells were enriched for several stem cell-associated genes including Lgr5. Lgr5 high cells of AOM/DSS-induced mouse colon tumors displayed higher Wnt signaling compared to both their Lgr5 low tumor cell counterparts as well as Lgr5 high normal colon stem cells. Lgr5 high and low tumor cells were both chromosomally stable. In conclusion, our data suggest Lgr5 as a functionally important marker for stem-like cells in CRC, representing a potential therapeutic target.

Citation Format: Daniela D. Hirsch, Nick Barker, Nicole McNeil, Yue Hu, Jordi Camps, Katherine McKinnon, Hans Clevers, Thomas Ried, Timo Gaiser. Stem cell hypothesis and function of Lgr5 in the development of colon cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5023. doi:10.1158/1538-7445.AM2013-5023
Abstract 5026: Targeting non-canonical Wnt signaling in acute myeloid leukemia.
Authors: de Boer Jasper , Walf-Vorderwulbecke Vanessa , Horton Sarah J. , Williams Owen
Published: August 2014

Childhood acute myeloid leukemia (AML) is a heterogeneous disease, with distinct cytogenetic sub-groups and responses to chemotherapy. Greater understanding of the molecular mechanisms underlying the different forms of this disease offers the possibility of developing novel therapies targeting disease-specific signaling pathways. We have recently analysed the role of non-canonical Wnt signaling induced Rac activation in the most frequent sub-type of childhood AML, associated with chromosomal translocations affecting the mixed lineage leukemia (MLL) gene. Our data indicate that MLL-fusions utilize non-canonical Wnt signaling, by inducing transcriptional activation of Frat gene expression and stimulating Rac activation through a signaling pathway involving GSK3 and DVL1 components. This pathway can be disrupted by shRNA-mediated silencing of Frat or Dvl expression, or by pharmacological inhibition of GSK3. Interestingly, the DVL-GSK3 signaling pathway can be disrupted by expression of a dominant negative FRATN mutant, that lacks the GSK3-binding domain, even in the absence of endogenous FRAT expression. FRATN inhibits growth, survival and disease progression of MLL-fusion expressing leukemic cells. These experiments have now been extended to the analysis of the anti-leukemia effects of FRATN expression in non-MLL-rearranged leukemia cell lines. This study highlights the potential of this novel signaling pathway as a target for future novel therapies of AML.

Citation Format: Jasper de Boer, Vanessa Walf-Vorderwulbecke, Sarah J. Horton, Owen Williams. Targeting non-canonical Wnt signaling in acute myeloid leukemia. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5026. doi:10.1158/1538-7445.AM2013-5026