bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2004: S100A4 in colorectal cancer - biological function of nuclear localization
Authors: Egeland Eivind V. , Boye Kjetil , Flatmark Kjersti , Pettersen Solveig J. , Oyjord Tove , Maelandsmo Gunhild M.
Published: May 2015

S100A4 is a Ca2+-binding protein promoting metastasis in several types of tumors. The protein possesses a wide variety of biological functions, and locates to different subcellular compartments including the nucleus, cytoplasm and extracellular space. Even though S100A4 is mainly localized in the latter two compartments, we have previosusly shown that the protein is localized to the nucleus in more aggressive forms of colorectal cancer (CRC) and that nuclear S100A4 has prognostic impact. This may suggest a function of nuclear S100A4 in the regulation of tumor progression and metastasis formation.

The CRC cell line SW620 shows heterogeneity in nuclear S100A4 expression and in preliminary experiments we sorted cells into three distinct phases of the cell cycle using Fluorescent-activated cell sorting (FACS). When comparing the phases, the G2/M cells showed increased accumulation of nuclear S100A4 compared to cells in the G1 and S phase, respectively. Further validation was done using treatment with the cell cycle inhibitors nocodazole or thymidine, followed by subsequent release of cells. Protein expression of S100A4 at selected time points after release did also show accumulation in the nucleus around the G2/M transition making this subcellular translocation interesting for further investigation. Cancer cells are known to have a dysfunctional cell division apparatus and these results made it tempting to speculate whether S100A4 may be involved in cell cycle regulation. To further study the functional importance of the nuclear expression two different approaches were followed.

First, CRC cells exclusively expressing S100A4 in the nucleus were made and used to identify downstream targets of nuclear S100A4. At the moment potential targets are being validated.

Furthermore, we searched for factors known to be associated with the G2/M phase. Of great interest, the Proximity Ligation Assay (PLA) demonstrated that S100A4 and Cyclin B1, an important regulator of the G2/M transition, are within the same protein complex, and we are currently in the process of further characterizing this interaction.

With clinical data linking nuclear expression of S100A4 with aggressive CRC, elucidation of the biological processes involved might unravel novel therapeutic possibilities.

Citation Format: Eivind V. Egeland, Kjetil Boye, Kjersti Flatmark, Solveig J. Pettersen, Tove Oyjord, Gunhild M. Maelandsmo. S100A4 in colorectal cancer - biological function of nuclear localization. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2004. doi:10.1158/1538-7445.AM2014-2004
Abstract 201: The combination treatment of TNF-α and poly (dA:dT) preactivated hMSCs with doxorubicin enhances antitumorigenic activity
Authors: Yoon Nara , Park Min Sung , Peltier Grant , Reneau John C. , Prockop Darwin J. , Prockop Darwin J. , Lee Ryang Hwa
Published: May 2015

Our recent study showed that human mesenchymal stem/stromal cells (hMSCs) were activated to express TRAIL by exposure to TNF-α. These TRAIL expressing hMSCs effectively induced apoptosis in MDA-MB-231 (MDA) cells in vitro and in vivo. TRAIL was further up-regulated by RNA released by dead MDA cells in a TLR3-dependent manner. Here, we show that the further increase of TRAIL in hMSCs was also mediated by feed-forward stimulation of AIM2 or IFIH1 by DNA and RNA released from dead MDA cells. Poly(dA:dT), a synthetic ligand for AIM2, most effectively activated hMSCs to express TRAIL and increased the killing efficacy of hMSCs in MDA cells compared to TNF-α or poly(I:C), a synthetic ligand for TLR3 or IFIH1. Furthermore, weekly infusions of hMSCs pre-activated with TNF-α and poly(dA:dT) effectively inhibited the progression of lung tumor formation in mice, compared to TNF-α pre-activated hMSCs. Such anti-tumorigenic effect of hMSCs upon activation with TNF-α and poly(dA:dT) was enhanced when combined with chemotherapeutic drug, doxorubicin and thereby, this combination treatment significantly reduced the size of tumor burden in mice compared to TNF-α pre-activated hMSC treatment. These results suggest that treatment of pre-activated hMSCs combined with doxorubicin enhances their tumor-suppressive properties and may provide a potential novel therapy for cancer treatment.

Citation Format: Nara Yoon, Min Sung Park, Grant Peltier, John C. Reneau, Darwin J. Prockop, Darwin J. Prockop, Ryang Hwa Lee. The combination treatment of TNF-α and poly (dA:dT) preactivated hMSCs with doxorubicin enhances antitumorigenic activity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 201. doi:10.1158/1538-7445.AM2014-201
Abstract 2014: SHP2 stabilizes EGFR and beta-catenin to promote the transformation and tumorigenic potential of basal-like and triple-negative breast cancer cells
Authors: Zhao Hua , Agazie Yehenew M.
Published: May 2015

Basal-like and triple-negative breast cancer (BTBC) causes disproportionately high mortalities in women. One of the major reasons is lack of targeted therapy, and the other is the highly aggressive and metastatic nature of the disease. The primary complication in finding viable drug targets has been the dysregulation of multiple signaling pathways, making one pathway inhibition an unlikely strategy to lead to effective treatment for BTBC. Therefore, targeting multiple pathways or finding proteins that control multiple signaling pathways and targeting them remain to be the only hope. In line with this, we have discovered that the Src homology phosphotyrosyl phosphatase 2 (SHP2) controls EGFR and Wnt/β-catenin signaling, major pathways known to be dysregulated in BTBC. We show that SHP2 overexpression in BTBC tumors is associated with elevated EGFR expression and cytoplasmic and nuclear accumulation of β-catenin. Silencing SHP2 expression in BTBC cells destabilizes EGFR and β-catenin and inhibits respective downstream signaling, confirming that SHP2 overexpression is essential for dysregulation of EGFR and β-catenin in this subtype of breast cancer. Furthermore, we demonstrate that inhibition of SHP2 in BTBC cells induces luminal epithelial morphology, suppresses cell proliferation, reverses transformation, blocks invasiveness in 3D matrigel, and abolishes tumorigenesis and metastasis. These findings suggest that SHP2 controls the EGFR and the Wnt/β-catenin signaling pathways to promote BTBC.

Citation Format: Hua Zhao, Yehenew M. Agazie. SHP2 stabilizes EGFR and beta-catenin to promote the transformation and tumorigenic potential of basal-like and triple-negative breast cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2014. doi:10.1158/1538-7445.AM2014-2014
Abstract 2021: A novel model to study the stroma-induced drug resistance in glioblastoma cells
Authors: Yang Ning , Zhu Huaiyang , Yan Tao , Liang Xiao , Leiss Lina Wik , Enger Per Øyvind , Li Xingang , Wang Jian
Published: May 2015

Glioblastomas (GBMs) are lethal cancers with a limited response to chemotherapies. In order to study whether stromal cells convey drug resistance to glioma cells, we have established a 3 D glioma cell-specific bioluminescence assay which mimics the growth of glioma in vivo and allows for direct measurements of tumor cell viability. With lentiviral transfection experiments we have provided a panel of human glioma cell lines stably expressing the luciferase reporter gene. Luciferase expression was proportional to the number of glioma cells, but not influenced by the presence of stromal cells. This way, Luciferase signal detection could be used to monitor glioma cell viability following treatment. Glioma cells alone or cultured with stromal cells can form 3 D spheroids, then treated with Temozolomide and Doxorubicin. Through comparative analysis, stromal cells influenced the sensitivity of different chemotherapy drugs in several glioma cell lines. Experiment also proved bioluminescence assay was more sensitive than MTS assay in co-culture system. This glioma cell-specific bioluminescence platform possibly provided a tool to screen stroma-induced changes in anti-tumor drug activity. Using the platform, we will be able to screen FDA-approved drugs on different glioma cell lines and biopsies, which will potentially guide the selection of tumor associated stromal specific targets for therapeutic validation.

Citation Format: Ning Yang, Huaiyang Zhu, Tao Yan, Xiao Liang, Lina Wik Leiss, Per Øyvind Enger, Xingang Li, Jian Wang. A novel model to study the stroma-induced drug resistance in glioblastoma cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2021. doi:10.1158/1538-7445.AM2014-2021
Abstract 2029: Insight of 3D multicellular tumor spheroids for innovative culture models of potential relevance for the screening of anti-CRC compounds
Authors: Däster Silvio , Amatruda Nunzia , Calabrese Diego , Zajac Paul , Spagnoli Giulio C. , Iezzi Giandomenica , Mele Valentina , Muraro Manuele Giuseppe
Published: May 2015

OBJECTIVE - Multicellular tumor spheroid is a well-known method for 3D in-vitro culture that better represent in-vivo condition. We exploited this system to culture human established colorectal cell lines to investigate how the presence or absence of hypoxic and/or necrotic area can influence the gene expression profile and the responsiveness to drugs compared to 2D-culture and in-vivo xenografted cells.

METHODS - HT29 cell line was cultured as MCTS by hanging-drop method. At size-defined time-point spheroids were analyzed for the presence of hypoxic and necrotic areas. The expression of a panel of genes related to tumor progression, metastatic behavior, and drug resistance was evaluated by real time PCR on MCTS at different growth stages in comparison to conventional 2D cultures and xenografts generated upon injection of HT29 cells in immunodeficient mice.

RESULTS - Based on the absence or presence of hypoxic and/or necrotic core, we identified three different MCTS growth stages: stage 1 (MCTS diameter size <200μm) defined by the absence of hypoxia/necrosis, stage 2 (300-350μm) characterized by the presence of hypoxic, but not apoptotic or necrotic areas, and stage 3 (>500μm) identified by the presence of both hypoxic and necrotic areas. The expression of a panel of genes, including putative cancer stem cell markers CD133, CD44, CD24 was found to be upregulated in stage 1 MCTS, as compared to 2D cultures. Most interestingly a further upregulation of these genes was detected in stage 2 and especially in stage 3. Importantly, expression levels in stage 3 were the most similar to those detected in xenografts.

CONCLUSION - Our results showed that culture of CRC cell lines offer the opportunity to investigate in standardized condition different MCTS stages possibly proving an improved model of in-vivo tumor growth. The next generation sequencing and drug-responsiveness of tumor cells cultured in 2D and 3D at different spheroid maturation stages is currently being evaluated.

Citation Format: Silvio Däster, Nunzia Amatruda, Diego Calabrese, Paul Zajac, Giulio C. Spagnoli, Giandomenica Iezzi, Valentina Mele, Manuele Giuseppe Muraro. Insight of 3D multicellular tumor spheroids for innovative culture models of potential relevance for the screening of anti-CRC compounds. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2029. doi:10.1158/1538-7445.AM2014-2029
Abstract 2034: Development of 3D bioprinted human breast cancer for in vitro drug screening
Authors: King Shelby M. , Presnell Sharon C. , Nguyen Deborah G.
Published: May 2015

As breast cancer is a disease of multiple cell types in which the growth, invasion, and metastasis of epithelial carcinomas is heavily influenced by the surrounding cell types, screening of anti-cancer compounds using cancer cell lines grown in 2D often overestimates drug potency. Regulatory agencies are currently seeking improved preclinical oncology models to overcome hurdles to efficient drug development, including bridging the gap between the use of 2D cell lines and 3D animal models. One way to more accurately determine the effects of anti-cancer compounds is through the use of cancer tissue models that incorporate stromal cells of the tumor microenvironment. Breast stroma, composed of fibroblasts, endothelial cells, and adipocytes, plays a key role in the process of carcinogenesis and metastasis. These cell types secrete extracellular matrix, growth factors, and hormones that affect how therapeutic agents access and target cancer cells. We have used Organovo's NovoGen BioprintingTM Platform to develop a model of human breast cancer in which a core of breast cancer cells is surrounded by a physiologically-relevant stromal milieu consisting of adipocytes, mammary fibroblasts, and endothelial cells. This system has several advantages over current screening tools, including the ability to simultaneously measure the effects of small molecules on cancer cells as well as different cell types in the breast microenvironment. Histological analyses of bioprinted neotissues demonstrated that they were stable and viable for at least 14 days in culture and characterized by interaction between stroma and carcinoma compartments. Incorporation of endothelial cells into the 3D neotissue led to the formation of robust microvascular networks. Breast cancer neotissues were fabricated directly into multi-well plates and used to establish biological response profiles to the standard chemotherapeutic agents cisplatin, paclitaxel, methotrexate, and tamoxifen. The cytotoxic effects of chemotherapeutic drugs on specific cell types within the neotissues were assessed biochemically and histologically. he response of the 3D breast cancer neotissues to chemotherapeutic gents was compared to the response of 2D breast cancer cell lines to determine he relative efficacy of compounds in 2D versus 3D. This model can be used to screen new anti-cancer therapeutics in the context of the in vivo-like microenvironment, leading to enhanced efficiency and accuracy of the drug development process.

Citation Format: Shelby M. King, Sharon C. Presnell, Deborah G. Nguyen. Development of 3D bioprinted human breast cancer for in vitro drug screening. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2034. doi:10.1158/1538-7445.AM2014-2034
Abstract 2038: Establishment and analysis of an in vitro model for hemangioblastomas of the central nervous system
Authors: Metelo Ana Martins , Lockerman Elizabeth , Barker Fred , Engelman Jeffrey , Iliopoulos Othon
Published: May 2015

Von-Hippel Lindau (VHL) disease is a familial genetic syndrome characterized by a germline mutation in the VHL gene. VHL patients develop different tumors, including renal cell carcinomas, pheochromocytomas and hemangioblastomas (HB). HBs are complex tumors located in the central nervous system and are currently the main cause of morbidity and mortality among VHL patients. 60-80% percent of VHL patients will develop multiple, synchronous or metachronous HBs in the Central Nervous System. These tumors can also occur sporadically. HBs are refractory to radiation or current targeted therapies. Surgery is the only treatment modality, but due to their location (brain, cerebellum, spine and retina) surgery may be debilitated or not even feasible at all.

Both alleles of the VHL gene were reported as inactivated (mutations and LOH studies) in both VHL-related and sporadic HB, but the cellular component(s) harboring this bi-allelic inactivation are unknown. HBs have a complex histology and unclear cell lineage. They are known to consist of a network of stromal cells, endothelial cells and pericytes. Hematopoetic cells may also be present in some HB tumors. In addition to this cellular complexity, the origin of the tumor cell -“stromal cell” - remains unknown.

To gain insight into the biology and therapeutic targets of HB, we established an in vitro model of the disease. Using modifications of a previously described technique (Am J Pathol. 2012;180(2):599-607) we generated cell lines from hemangioblastomas of VHL patients. This approach allows the propagation of diverse cell clones, reflecting the complexity of the tumor microenvironment. The different clones and polyclonal populations were characterized using qRTPCR and immunofluorescence. The molecular and phenotypic analysis of the cell lines will be presented. This resource is fundamental for the study of HB biology and it will allow us to dissect the cellular origin of these tumors. In addition, it may facilitate the development of HB xenografts.

Citation Format: Ana Martins Metelo, Elizabeth Lockerman, Fred Barker, Jeffrey Engelman, Othon Iliopoulos. Establishment and analysis of an in vitro model for hemangioblastomas of the central nervous system. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2038. doi:10.1158/1538-7445.AM2014-2038
Abstract 2042: Deregulated TS promotes tumor progression in diverse hematopoietic and mesenchymal cell lineages
Authors: Chen Min , Nawab Akbar , Kaye Frederic J. , Zajac-Kaye Maria
Published: May 2015

Our laboratory recently showed that elevated TS plays a direct causal role in tumorigenesis of NIH3T3 cells in vitro and in the development of endocrine pancreatic mouse tumors in vivo. This observation changed the paradigm of TS as a passive biomarker and has significance for cancer treatment as it refocuses attention on the importance of TS as a tumor-promoting signal. To address whether TS plays an early role in tumorigenesis that is restricted to specific tumor types or if TS plays a late role associated with enhanced progression of established tumors of diverse histologic origin, we have now cross-bred human TS (hTS) transgenic mice with Ink4a/Arf null mice, a common somatic mutation frequently found in adult human cancers. Median survival of hTS/Ink4a/Arf+/- (n=15) mice was reduced 24% (313 vs. 411 days, p <0.05). Both hTS/Ink4a/Arf+/- and hTS/Ink4a/Arf-/- mice (n=16) showed an increase in lymphoma, histiocytic sarcoma (HS) and soft tissue sarcoma (SS). For example, the incidence of HS in hTS/Ink4a/Arf-/- male mice was 31% versus 12% in Ink4a/Arf-/- minus (p<0.01), and tumor cells had spread to multiple tissues (as many as 9 different organs) as compared to hTS minus mice where tumors were localized in lymph nodes and spleen. Strikingly, the tumor burden was markedly increased in hTS/Ink4a/Arf-/- mice: average spleen weight 1.11 vs. 0.49 g, p<0.001, lymph nodes, 1.06 g vs. 0.42 g, p<0.001. We also detected an increase in size and extent of tumor mass of SS (average weight 5.8 g). We detected increased aneuploidy in hTS/Ink4a/Arf-/- HS cell lines as compared to Ink4a/Arf-/- HS cell lines: chromosomal loss 32.1% vs. 16.7%, p<0.05, gain 24.5% vs. 0%, p<0.001 and translocations 9.4% vs. 0%, p<0.05 by spectral karyotyping analysis. Treatment of TS positive HS tumor cells with lenti-TS shRNAs downregulated TS expression and resulted in tumor growth inhibition in vitro as well as in mouse orthotopically transplanted xenograft. In addition, combined TS shRNAs with gemcitabine or pemetrexed treatment showed synergistic inhibition of HS tumor cell growth. These data demonstrate that deregulated TS enhanced genome instability and promote tumor progression in diverse hematopoietic and mesenchymal tumor cells.

Citation Format: Min Chen, Akbar Nawab, Frederic J. Kaye, Maria Zajac-Kaye. Deregulated TS promotes tumor progression in diverse hematopoietic and mesenchymal cell lineages. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2042. doi:10.1158/1538-7445.AM2014-2042
Abstract 205: Imatinib sensitizes endometrial cancer cells to cisplatin by targeting CD117-positive growth-competent cells
Authors: Nakamura Mitsuhiro , Kyo Satoru , Zhang Xiuzhi , Takakura Masahiro , Mizumoto Yasunari , Bono Yukiko , Sasagawa Toshiyuki , Fujiwara Hiroshi
Published: May 2015

The use of molecular target therapy has not been established for endometrial cancer. The present study investigated the potential therapeutic strategy of targeting CD117-positive cancer cells as a novel molecular target therapy. FACS-sorted CD117+ cells isolated from endometrial cancer cell lines (Ishikawa or MFE280 cells) exhibited higher proliferative capacity in vitro and colony forming activity on soft agar, and decreased sensitivity to cisplatin, compared to CD117- cells. Immunohistochemical analyses with surgical specimens of endometrial cancers showed that high CD117 expression was tightly linked to advanced FIGO stages, myometrial invasion and histological grade, and was significantly associated with poor overall survival and relapse-free survival (Kaplan-Meier analysis; p<0.001, log-rank test). The Cox-regression hazard model identified high CD117 expression to be an independent prognostic factor for survival (p<0.05). In vitro assay confirmed that stem cell factor (SCF), a ligand of CD117, was produced specifically in CD117+ cells of endometrial cancer, and the colony-forming activity were abrogated by adding anti-SCF antibody, indicating an SCF-dependent growth property. Imatinib was confirmed to selectively target CD117+ cells in vitro, and synergistically enhanced the anti-tumor effect of low dose cisplatin in vivo, which showed only modest effects when used as a single use. These findings suggest that CD117 can be a marker of aggressive behavior of cells as well as an independent prognostic marker in endometrial cancer. Targeting of the SCF/CD117 axis by imatinib sensitized endometrial cancer cells to cisplatin, proposing a novel therapeutic strategy for this tumor type.

Citation Format: Mitsuhiro Nakamura, Satoru Kyo, Xiuzhi Zhang, Masahiro Takakura, Yasunari Mizumoto, Yukiko Bono, Toshiyuki Sasagawa, Hiroshi Fujiwara. Imatinib sensitizes endometrial cancer cells to cisplatin by targeting CD117-positive growth-competent cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 205. doi:10.1158/1538-7445.AM2014-205
Abstract 2056: Identification of microscopic ovarian tumor foci utilizing a novel imaging device in a murine ovarian cancer model, an opportunity to improve optimal cytoreduction
Authors: Na Youngjeong , Kwok Tim , Awtrey Christopher , Strasfeld David B. , Ferrer Jorge M. , Lee David , Birrer Michael J.
Published: May 2015

Survival of ovarian cancer patients is directly related to the amount of residual disease present after debulking surgery. In 80% of the cases, extensive microscopic cancer remains even after the patient is deemed optimally debulked. Hence, detection of sub-mm cancer clusters during tumor excision is a critical unmet need. Recent studies have shown that reducing the dimensions of residual cancer to less than 1 mm significantly improves clinical outcomes. In the present study we evaluate the performance of a fluorescent, molecular imaging agent, LUM015 (Lumicell, Wellesley, MA), which is activated by cathepsin enzymes in the tumor, and a wide-field-of-view imaging device (Lumicell) to detect sub-mm residual cancer clusters in an mouse model for ovarian cancer.

In this study, we generated orthotopic ovarian cancer mouse models(n=10) with well characterized serous ovarian cancer cell lines, CP70 and SKOV3. Once the tumor disseminated, the imaging agent LUM015 (3.52 mg/kg) was injected via the tail vein, and after 6 hours, the mice were euthanized. Tumor debulking was performed throughout the abdominal cavity. After debulking, the whole abdominal wall was dissected in 4 quadrants, organs were harvested and all were imaged with the LUM device. Features exhibiting high fluorescence were marked and dissected, prepared into slides, and stained with hematoxylin and eosin for pathologic correlation with LUM015 fluorescence imaging.

In 36 tissues from orthotopic ovarian cancer mouse models, LUM015 imaging system could detect the tumor presence with 100% of sensitivity and 60% of specificity. We demonstrated that the imaging system can detect sub-mm cancer clusters that could not be identified with visual inspection.

With a cathepsin activated fluorescence imaging molecule (LUM015) and a wide-field-of-view imaging device, we detected microscopic residual ovarian cancer tumors in orthotopic xenograft models after debulking grossly with high sensitivity. Translation of this imaging technology into the clinical setting may help to detect microscopic residual tumor features during the debulking operation in ovarian cancer.

Citation Format: Youngjeong Na, Tim Kwok, Christopher Awtrey, David B. Strasfeld, Jorge M. Ferrer, David Lee, Michael J. Birrer. Identification of microscopic ovarian tumor foci utilizing a novel imaging device in a murine ovarian cancer model, an opportunity to improve optimal cytoreduction. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2056. doi:10.1158/1538-7445.AM2014-2056
Abstract 2061: Extended adjuvant temozolomide improves survival in a glioblastoma mouse model
Authors: Wang Hanxiao , Al-Holou Wajd , Heist Kevin , Galbán Craig J. , deCarvalho Ana C. , Mikkelsen Tom , Ross Brian D. , Rehemtulla Alnawaz
Published: May 2015

Glioblastoma (GBM) represents the most aggressive malignant primary brain tumor. Temozolomide (TMZ) is a standard of care for newly diagnosed GBM patients in conjunction with ionizing radiation (IR) or as an adjuvant agent. Yet the prognosis of GBM remains devastating with a median survival of 14 months. We investigated whether extended TMZ treatment cycles would provide survival benefit for GBM patients. To recapitulate the genomic and pathological heterogeneity found in GBM patients, we utilized patient derived xenograft (PDX) mouse models.

We demonstrated that the combination of TMZ and IR prevents tumor progression, but tumors ultimately recur and lead to death. Overall survival was prolonged when adjuvant TMZ treatment was administered with minimal toxicity. Additionally, development of resistance to TMZ and IR was often correlated with an increase in levels of MGMT protein, irrespective of the promoter methylation status. Moreover, we demonstrate the utility of a voxel-based MRI biomarker, the functional diffusion map (fDM), as an imaging surrogate to detect spatially varying changes in tumor response, as well as a more sensitive predictor of overall response versus whole-volume tumor measurements. The fDM biomarker was also useful as an early predictor of impeding resistance to TMZ and IR.

In summary, we demonstrate that prolonged TMZ treatment should be considered for the treatment of GBM patients. Furthermore, MRI based imaging allows early prediction of therapy response as well as impeding resistance.

Citation Format: Hanxiao Wang, Wajd Al-Holou, Kevin Heist, Craig J. Galbán, Ana C. deCarvalho, Tom Mikkelsen, Brian D. Ross, Alnawaz Rehemtulla. Extended adjuvant temozolomide improves survival in a glioblastoma mouse model. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2061. doi:10.1158/1538-7445.AM2014-2061
Abstract 2070: In vivo imaging of therapy response to novel antibody mixtures targeted at the human epidermal growth factor receptor family using FDG and FLT positron emission tomography
Authors: Nielsen Carsten H. , Jensen Mette M. , Jacobsen Helle J. , Poulsen Thomas T. , Horak Ivan D. , Lantto Johan , Kragh Michael , Kjaer Andreas
Published: May 2015

Dysregulation and overexpression of the human epidermal growth factor receptor (HER) family plays an important role in many cancers. Simultaneously targeting multiple members of the HER family may increase the therapeutic efficacy. Here, we report the ability to image the therapeutic response obtained by targeting the HER family members individually or simultaneously using novel monoclonal antibody (mAb) mixtures.

Mice with subcutaneous BxPC-3 pancreas adenocarcinomas were divided into five groups (n=8) receiving vehicle or mAb mixtures directed against HER1 (EGFR), HER2, HER3, or pan-HER. Small animal positron emission tomography/computed tomography (PET/CT) with 18F-FDG and 18F-FLT was performed at baseline and day 1 or 2 after initiation of therapy. The changes in tumor uptake of tracers were quantified and related to the efficacy of each therapy on tumor size measured by caliper. Imaging results were further validated by immunohistochemistry on tumor samples obtained 2 and 7 days after initiation of therapy.

The pan-HER mAb mixture showed the greatest efficacy with significant smaller tumor volumes (146±39 mm3, Mean ±SEM) compared with the other groups (vehicle: 660±99 mm3, EGFR: 363±67 mm3, HER2: 458±45 mm3, HER3: 274±37 mm3) at the end of therapy (day 23). Mean FDG and FLT uptake in the pan-HER group decreased by 19±4.3% and 24±3.1%, respectively, at day 1 or 2 compared with baseline, which was significantly greater than for the other groups. Importantly, the early change in mean FDG and FLT uptake correlated with tumor growth at day 23 relative to day 0 (r=0.67, p<0.001; r=0.63, p<0.001, respectively).

In conclusion, we demonstrate the ability to image therapeutic responses to a novel pan-HER mAb mixture using PET/CT imaging with FDG and FLT. We suggest the use of FDG and FLT PET/CT as an imaging biomarker in clinical evaluation of the pan-HER mAb mixture.

Citation Format: Carsten H. Nielsen, Mette M. Jensen, Helle J. Jacobsen, Thomas T. Poulsen, Ivan D. Horak, Johan Lantto, Michael Kragh, Andreas Kjaer. In vivo imaging of therapy response to novel antibody mixtures targeted at the human epidermal growth factor receptor family using FDG and FLT positron emission tomography. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2070. doi:10.1158/1538-7445.AM2014-2070
Abstract 2073: Neutrophil serine proteases, cathepsin-G and elastase, promote metastasis through cleavage of thrombospondin-1
Authors: Rayes Tina E. , Catena Raul , Lee Sharrell , Gao Dingcheng , Stawowczyk Marcin , Altorki Nasser , Mittal Vivek
Published: May 2015

Inflammation is known to be inextricably associated with tumor progression. However, the role of inflammation in metastatic initiation and outgrowth remains largely unexplored. In our study, we show that CXCR2-CXCL2-dependent recruitment of neutrophils supported a pro-metastatic phenotype in acutely inflamed lungs. The increased influx of Ly6G+ neutrophils into inflamed lungs was accompanied by a loss of thrombospondin-1 (Tsp-1) protein. In vitro, the degranulation of neutrophils was marked by an increase in the activity of the neutrophil proteases elastase and cathepsin-G, leading to degradation of Tsp-1, which was protected by using the protease inhibitor Sivelestat. Whereas genetic ablation of either cathepsin-G or elastase in vivo partially impaired metastasis, pharmacological inhibition of both neutrophil proteases, using the small molecule drug Sivelestat, dramatically suppressed metastasis.

We have uncovered a novel pathway in which the serine proteases, cathepsin-G and elastase produced by degranulating neutrophils, promote a metastasis-conducive microenvironment through the cleavage of Tsp-1. Our results provide mechanistic insights into how inflammatory components of the premetastatic niche can support metastatic outgrowth, and they suggest that the neutrophil protease-Tsp-1 axis presents a therapeutic target against metastatic cancers.

Citation Format: Tina El Rayes, Raul Catena, Sharrell Lee, Dingcheng Gao, Marcin Stawowczyk, Nasser Altorki, Vivek Mittal. Neutrophil serine proteases, cathepsin-G and elastase, promote metastasis through cleavage of thrombospondin-1. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2073. doi:10.1158/1538-7445.AM2014-2073
Abstract 2086: PLK1 promotes epithelial-to-mesenchymal transition, confers oncogenic potential, and targets metastasis in prostate cancer
Authors: Wu Jianguo , Ivanov Andrei , Zhang Jinglei , Fu Zheng
Published: May 2015

Polo-like kinase 1 (PLK1) has been well characterized as a master cell cycle regulator and implicated in the initiation and progression of different types of cancer and subsequently highlighted as a promising target for cancer therapy. It is canonically regarded that PLK1 deregulation promotes cancer development via catastrophic cell cycle events such as centrosome replication disturbance and chromosome instability. Recently, PLK1 has been shown to act as a regulator of cancer cell invasion, however, mechanisms underlying the effects of PLK1 on cell motility remain elusive. PLK1 is frequently upregulated in prostate cancer (PCa) and its expression level positively correlates with tumor grade and prognosis. Whether and how PLK1 contributes to the development and dissemination of PCa are still need to be investigated. Here, we showed PLK1 induces EMT in prostate epithelial cells and is required for prostate cancer cell lines to keep mesenchymal properties. We demonstrated that enhanced PLK1 expression transforms prostate epithelial cells to malignancy. Moreover, we found that PLK1 promotes invasion and is required for the metastasis of prostate cancer cells. Our data indicate that PLK1 is an EMT player and acts as an oncogene. These findings provide new sights into the non-mitotic function of PLK1 and suggest PLK1 as a potential target for intervention of the metastasis of prostate cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Jianguo Wu, Andrei Ivanov, Jinglei Zhang, Zheng Fu. PLK1 promotes epithelial-to-mesenchymal transition, confers oncogenic potential, and targets metastasis in prostate cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2086. doi:10.1158/1538-7445.AM2014-2086
Abstract 2089: MMP7-mediated cleavage of nucleolin at the Asp255 induces MMP9 expression to promote tumor malignancy
Authors: Hung Jan-Jong , Chang Wen-Chang
Published: May 2015

Nucleolin, expressed in various cellular compartments, participates in DNA transcription, ribosomal biogenesis, regulation of RNA stability. It is evidence that the posttranslational cleavage of nucleolin determine the fate of cells, apoptosis or proliferation. However, the contributions of nucleolin accumulation and cleavage to tumor development are still not clear. Herein we found that nucleolin was dramatically increased in lung cancer and correlated with poor prognosis. The overexpressed nucleolin was cleaved to the smaller fragment (55 kDa), identified in human lung cancer and mouse models of lung cancer. To study the activated mechanism found that EGF-mediated EGFR and KRAS activations could enhance nucleolin expression through increasing Sp1-mediated transcription. Furthermore, to clarify the cleavage residue and cutting enzyme found that nucleolin could be cleaved at 255th Asp by MMP7 (255-710 a.a., TNCL). By using overexpression of TNCL indicated that TNCL enhanced proliferation and metastasis in vitro and in vivo. To further clarify the mechanism of TNCL-enhanced tumor malignancy show that TNCL significantly increase several oncogenes expression including MMP9, Alk and CD74 through associating with 3′-UTR to enhance mRNA stability. Taken together, MMP7 can cleave nucleolin to increase the oncogenes expression, leading lung cancer formation

Citation Format: Jan-Jong Hung, Wen-Chang Chang. MMP7-mediated cleavage of nucleolin at the Asp255 induces MMP9 expression to promote tumor malignancy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2089. doi:10.1158/1538-7445.AM2014-2089
Abstract 2092: Elevated PKCα expression and its association with Notch signaling in localized and metastatic prostate cancers
Authors: Zhou Xinchun , Zhu He , Zhang Xu , Lewin Jack , Miele Lucio
Published: May 2015

Background: Conventional protein Kinase C alpha (PKCα) is linked to the regulation of cell proliferation, differentiation, motility, survival, and apoptosis. Elevated PKCα expression has been reported in human early prostate cancer (PCa) and rat prostatic tumor cell lines. In this study, the expression level of PKCα was evaluated by immunohistochemistry (IHC) and correlated with the expression levels of Notch1 and Jagged1 in localized and metastatic PCa.

Methods: : IHC for PKCα was performed on tissue microarray (TMA) slides containing 156 formalin-fixed and paraffin-embedded (FFPE) prostatic tissues specimens, including 39 benign prostatic changes, 97 localized prostate cancers and 20 metastatic prostate cancers. The expression level of PKCα was reported as a final IHC score calculated as staining extent score (0-3) multiplied by intensity score (0-3) with a maximal score of 9. ANOVA was employed to reveal the differences in IHC scores among pathologic categories, followed by Tukey-adjusted pairwise comparisons. Spearman correlation coefficient was evaluated to measure correlation between expression levels of PKCα, Notch1, and Jagged1.

Results: IHC staining for PKCα was predominantly observed in cytoplasm (in 94% specimens). The score of PKCα cytoplasmic staining in metastatic PCa (5.48 ± 1.84, Mean ±SD) was significantly higher than those in localized PCa (3.30 ± 2.10, P = 2.95E-05) and in benign prostatic tissue (1.92 ± 1.53, P = 6.45E-09). Similarly, IHC score in localized PCa was significantly higher than that observed in benign prostatic changes (P = 0.001). Correlation analysis revealed that the expression level of cytoplasmic PKCα was significantly correlated with the expression levels of cytoplasmic Notch1 (r = 0.396, P = 5.85E-05), cytoplasmic Jagged1 (r = 0.610, P = 3.42E-11), and membranous Jagged1 (r = 0.354, P = 3.76E-04, respectively) in localized and metastatic prostate cancers.

Conclusions: Our results indicate that up-regulation of PKCα plays a role not only in PCa formation and progression, but also in PCa metastasis. The evidence of significant correlation between PKCα and Jagged1-Notch1 signaling pathway supports the notion that synergy of PKCα with Jagged1-Notch1 signaling may play an important role in modulating the tumorgenesis and metastasis in human PCa.

Citation Format: Xinchun Zhou, He Zhu, Xu Zhang, Jack Lewin, Lucio Miele. Elevated PKCα expression and its association with Notch signaling in localized and metastatic prostate cancers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2092. doi:10.1158/1538-7445.AM2014-2092
Abstract 2097: Distinct levels of circulating tumor cell counts for the papillary thyroid cancer patients with distant metastases and in disease-free status
Authors: Lin Hung-Chih , Cheng Ju-Chien , Tseng Ching-Ping , Lin Jen-Der
Published: May 2015

Distant metastasis of papillary thyroid cancer (PTC) is a multistep and complex process that frequently complicates the disease with poor prognosis. The presence of circulating tumor cells (CTCs) in the peripheral blood has been reported in several cancer types to be highly related to the development of distant metastasis. Nevertheless, the CTCs status during the progression of PTC is rarely investigated. This study aimed to define and compare the CTCs counts among the healthy control individuals (Group I, n = 14), the PTC patients in disease-free status (Group II, n = 9), and the patients with distant metastasis (Group III, n = 8). The patients in group III had metastases to the lung and mediastinum (n = 4), bones (n = 3), and lung and kidney (n = 1), respectively. CTCs were enriched from the peripheral blood by the negative selection method PowerMag that has been validated in our previous study. CTCs enumeration was performed by immunofluorescence staining using the anti-epithelial cell adhesion molecule (EpCAM) and anti-thyroid stimulating hormone receptor (TSHR) antibodies. The EpCAM+ and TSHR+ CTCs counts were 2.97 ± 2.03 and 9.97 ± 9.22 cells/mL for group I, 10.43 ± 9.03 and 19.17 ± 9.77 cells/mL for group II, and 100.06 ± 73.34 and 141.60 ± 82.08 cells/mL for group III individuals, respectively (p < 0.01). These data indicate that (1) some of the TSHR+-CTCs are not EpCAM+ and this type of cell population can be overlooked if CTCs were enriched by the method based on positive selection of EpCAM+ cells; (2) the PTC patients in disease-free status has higher CTCs counts than the healthy control individuals and, hence, continuous CTCs enumeration is recommended for the patient in the stage of disease-free; (3) the PTC patients with distant metastases have higher CTCs counts when compares to the healthy control subjects and the patients with disease-free status. In conclusion, CTCs enumeration is thereby warranted in the course of diagnosis and treatment of thyroid cancer.

Citation Format: Hung-Chih Lin, Ju-Chien Cheng, Ching-Ping Tseng, Jen-Der Lin. Distinct levels of circulating tumor cell counts for the papillary thyroid cancer patients with distant metastases and in disease-free status. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2097. doi:10.1158/1538-7445.AM2014-2097
Abstract 2105: Regulation of estrogen receptor turnover by lysine 302 methylation
Authors: Zoeller Elizabeth L. , Barsyte-Lovejoy Dalia , Brown Peter J. , Owen Dafydd R. , Arrowsmith Cheryl H. , Vertino Paula M.
Published: May 2015

The estrogen pathway promotes growth of breast cancer, the leading cancer diagnosis among US women. The antiestrogen therapy Tamoxifen has been the mainline therapy for the 70% of women whose tumors are estrogen receptor alpha (ERα) positive for over thirty years. Understanding how ERα is regulated, particularly in the context of Tamoxifen, is essential for the treatment of breast cancer. In previous work, we showed that SetD7 mediated methylation of ERα at lysine 302 (K302) is a key mediator of estrogen receptor alpha stability. Downregulation of SetD7 or mutation of K302 increased the rate of ERα turnover resulting in a compromised estrogen driven transcriptional response. However, the precise mechanism by which lysine 302 methylation regulates ERα stability and transcriptional activity is not yet known. In this study, we used a novel small molecule inhibitor of SetD7, (R)-PFI-2, as a chemical probe to further investigate the role of K302 methylation in the regulation of ERα. Treatment of ERα expressing MCF7 breast cancer cells with (R)-PFI-2 resulted in a dose-dependent shift in the 66kDa ERα species to a slower migrating form as detected by protein electrophoresis and immunoblotting. Molecular mass estimates of this slower migrating form are consistent with a sumoylation event. Interestingly, (R)-PFI-2-induced accumulation of the slower migrating form was only observed upon inhibition of the proteasome with MG132, suggesting that this alternately modified form of ERα represents an intermediate in the pathway to degradation. A similar time-dependent shift to the same slower migrating form was observed upon estrogen depletion of MCF7 cells stably knocked down for SetD7, but not in control cells. Furthermore, an inverse relationship was observed between endogenous levels of SetD7 and the levels of modified ER in two strains of MCF7 cell line that differ in their sensitivity to Tamoxifen. These data suggest that methylation of ERα at K302 by SetD7 may stabilize ERα by blocking another post-translational modification, possibly sumoylation, necessary for its turnover. The relationship between ER methylation, sumoylation and Tamoxifen sensitivity will be discussed.

Citation Format: Elizabeth L. Zoeller, Dalia Barsyte-Lovejoy, Peter J. Brown, Dafydd R. Owen, Cheryl H. Arrowsmith, Paula M. Vertino. Regulation of estrogen receptor turnover by lysine 302 methylation. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2105. doi:10.1158/1538-7445.AM2014-2105
Abstract 2115: Interrogation of mechanisms that underlie augmented steroidogenesis in castration-resistant prostate cancer
Authors: Chang Kai-Hsiung , Sharifi Nima
Published: May 2015

The conversion of adrenal androgens, such as dehydroepiandrosterone (DHEA), to dihydrotestosterone (DHT) drives castration resistant prostate cancer (CRPC) progression. No mutations or variations in those steroidogenic enzymes have been identified as responsible for the phenotype of increased intratumoral DHT synthesis in CRPC. By analyzing CRPC cell line models and clinical samples from patients with CRPC, we found that a gain-of-stability mutation in 3β-hydroxysteroid dehydrogenase type 1 (3βHSD1, encoded by HSD3B1 gene) confers an increase in metabolic flux from DHEA to DHT in CRPC. The prolonged protein half-life of mutant 3βHSD1 results from resisting an association with the ubiquitin E3-ligase autocrine mobility factor receptor (AMFR). Genetic selection for mutant 3βHSD1 is evident from somatic mutation in human CRPC tumors, by loss of heterozygosity (LOH) of the wild type copy in patients with heterozygous inheritance, and from acquisition of same somatic mutation in a mouse xenograft tumor model treated with abiraterone. Furthermore, we found the expression of AMFR is suppressed in a CRPC xenograft model expressing wild type 3βHSD1, suggesting a compensatory mechanism that augments steroidogenesis in CRPC progression. Our discovery of this 3βHSD1 gain-of-function mutation is the first example of a mutation identified in a component of steroidogenic machinery in CRPC, which strongly validates a new target for individualized cancer therapy in CPRC.

Citation Format: Kai-Hsiung Chang, Nima Sharifi. Interrogation of mechanisms that underlie augmented steroidogenesis in castration-resistant prostate cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2115. doi:10.1158/1538-7445.AM2014-2115