bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1547: Circulating tumor cells from a syngeneic mouse model of hepatocellular carcinoma demonstrate epithelial-mesenchymal transition, decreased MHC I expression, and increased CCR7 expression
Authors: Huaman Jeannette A. , Muhith Ubayed , Das Dibash K. , Naidoo Michelle , Ogunwobi Olorunseun O.
Published: July 2016

Metastasis is the leading cause of death in cancer patients, worldwide. A better understanding of how cancer cells detach from the primary tumor, escape from immunosurveillance while in circulation, and successfully colonize distant parts of the body, is needed. Circulating tumor cells (CTCs) are excellent tools to study this process. Using a syngeneic hepatocellular carcinoma mouse model, we were able to isolate cancer cells from the primary tumor and CTCs from the blood and establish novel primary tumor-derived cell lines and novel CTC lines. Wound healing assays revealed that CTCs have greater migratory capacity than the cancer cells from the primary tumors. However, MTT assays revealed that CTCs had less proliferative capacity than the cancer cells from the primary tumors. Furthermore, molecular characterization of the cancer cells from primary tumors and CTCs using Western blotting showed a decreased expression of E-cadherin and an increased expression of fibronectin by CTCs, suggesting that epithelial-to-mesenchymal transition (EMT) takes place in CTCs in comparison to cancer cells from primary tumors. To address the question of how CTCs may evade immunosurveillance, we investigated the profile of expression of two cell surface proteins involved in immune system function: the major histocompatibility complex class I (MHCI)- required for cytotoxic T cell activation and subsequent cancer cell killing, and chemokine receptor 7 (CCR7)- exploited by cancer cells for immune evasion. Our analysis revealed that there is decreased cell surface expression of MHCI and increased expression of CCR7 in the CTCs in comparison to the cancer cells from primary tumors. These findings indicate that although CTCs are not more proliferative, they have acquired significantly increased migratory capacity than cancer cells in primary tumors. This may be explained by their demonstration of EMT. Furthermore, their loss of MHC I expression and their gain of CCR7 expression may help with evasion of killing by cytotoxic T cells and result in enhanced metastasis.

Citation Format: Jeannette A. Huaman, Ubayed Muhith, Dibash K. Das, Michelle Naidoo, Olorunseun O. Ogunwobi. Circulating tumor cells from a syngeneic mouse model of hepatocellular carcinoma demonstrate epithelial-mesenchymal transition, decreased MHC I expression, and increased CCR7 expression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1547.
Abstract 155: The analysis of the genomic evolution of squamous cell carcinoma of the lung
Authors: Krause Arthur , Lorber Thomas , Perrina Valeria , Dietsche Tanja , Barrett Michael , Ruiz Christian , Bubendorf Lukas
Published: July 2016

Background:

Genomic tumor heterogeneity is one reason for recurrence and resistance to cancer therapy. It is still not known what leads to the relapse or the emergence of metastasis in individual patients. To contribute to answer this question, we investigated the evolutionary patterns in squamous cell carcinoma of the lung (SCC) in 10 patients with multiple matched tumors (primary vs recurrence/metastasis).

Methods:

To identify the genomic profile, frozen tissues from SCC patients were subjected to multiparameter ploidy profiling (MPP). Tumor populations were sorted based on ploidy (DNA-content using DAPI) and p40 was used to control for diploid tumor populations. Subsequent genomic profiling by array comparative genomic hybridization (aCGH) and targeted massive parallel sequencing (Ion Torrent Comprehensive Cancer Panel with an all-exon coverage of 409 cancer genes) was applied.

Results:

The usage of MPP enabled the determination of the clonal composition of the SCC and define genomic characteristics. Due to flow sorting the tumor populations were effectively isolated and existence of distinct clonal populations was indicated. Aneuploid and diploid tumors were successfully revealed using the additional marker p40. Therefore, the absence of non-malignant cells increased the precision in the genomic analyses

Conclusion:

The study uncovered the composition of human SCC in the sense of different clonal populations, which harbor private genomic aberrations and mutations confirmed by aCGH and NGS. Even if our data is still preliminary we provide evidence that applying MPP increases the precision of aCGH and sequencing analysis. Genomic analyses of sorted pure tumor population allows to reconstruct the clonal evolution and facilitates the understanding of tumor heterogeneity and their evolutionary pattern, which could have potentially an impact on therapeutic response or metastasis development.

Citation Format: Arthur Krause, Thomas Lorber, Valeria Perrina, Tanja Dietsche, Michael Barrett, Christian Ruiz, Lukas Bubendorf. The analysis of the genomic evolution of squamous cell carcinoma of the lung. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 155.
Abstract 157: Single-cell DNA sequencing identifies a late dissemination model in metastatic colorectal cancer
Authors: Leung Marco L. , Casasent Anna , Wang Yong , Sei Emi , Navin Nicholas
Published: July 2016

Metastatic colorectal cancer (mCRC) is a devastating disease with only 11% 5-year survival rate for stage IV patients. The genomic basis of metastasis has been difficult to study, in part due to the extensive intratumor heterogeneity at both the primary and metastatic tumor sites. Previous studies have applied bulk next-generation sequencing (NGS) methods, which have limited ability to resolve intratumor heterogeneity. To address this problem, we developed a highly-multiplexed single cell DNA sequencing method that combines flow-sorting of single nuclei, multiple-displacement-amplification, low-input library preparation, library barcoding, targeted capture and NGS to generate high-coverage data from single tumor cells. To increase throughput, we performed targeted single-cell DNA sequencing using a panel of 201-cancer genes to analyze single cells from primary tumors and liver metastases from two mCRC patients. In each patient, we sequenced 90 single tumor cells from the primary and metastatic tumor, to delineate the clonal architecture of the tumor and reconstruct their phylogenetic lineages. In addition, we sequenced populations of tumor cells at high coverage depth (200X).

Our data identified a large number of nonsynonymous mutations that evolved in the root nodes during the earliest stages of primary tumor evolution and were maintained in all single cells during the clonal expansion of the tumor mass. We also identified a small number of mutations that were specific to the liver metastases, which are likely to play an important role in metastatic dissemination. Using the single cell data, we constructed phylogenetic trees, which revealed branched evolution at both organ sites. Collectively, our data suggest that both mCRC patients are consistent with a late-dissemination model, in which the primary tumors evolved for a long period of time prior to the dissemination of clones to distant organ sites. This model has important clinical implications, by suggesting that surgical intervention or therapeutic treatment of the primary CRC tumor can prevent metastasis, since single tumor cells do not disseminate at the earliest stages of tumor growth

Citation Format: Marco L. Leung, Anna Casasent, Yong Wang, Emi Sei, Nicholas Navin. Single-cell DNA sequencing identifies a late dissemination model in metastatic colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 157.
Abstract 1605: Cetuximab inhibits migration, invasion, metastasis and epithelial-mesenchymal transition but not proliferation via GEP100-Arf6-AMAP1 pathway in head and neck squamous cell carcinoma
Authors: Matsumoto Yoshifumi , Sakurai Hiroyuki , Kogashiwa Yasunao , Saito Koichiro
Published: July 2016

Background: Recently, irradiation combined with Cetuximab (Cmab) is being one of the standard therapeutic options against head and neck squamous cell carcinoma (HNSCC), especially in advanced/recurrent cases. While this concurrent chemo-radiotherapy is widely accepted and tolerated, Cmab monotherapy has been reported to be unsatisfactory to treat HNSCC, and detailed mechanism of Cmab to show such clinical efficacy is unknown.

Methods: To assess the impact of Cmab on proliferation, migration, and invasion of HNSCC, WST assay, wound healing assay, and matrigel invasion assay were incorporated in this study. Effects of Cmab on the grade of epithelial-mesenchymal transition (EMT), expression level of membrane type 1-matrix-metalloproteinase (MT1-MMP), and activity of EGFR-GEP100-Arf6-AMAP1 pathway, were evaluated using the immunocytochemistry, western blot analysis and Arf6 activation assay, respectively. Furthermore, In vivo efficacy of Cmab was evaluated in highly aggressive and metastatic HSC-3-M3 cells using orthotopic xenograft model in nude mice nu/nu.

Results: Inhibition of migration and invasion were observed in 4 HNSCC cell lines by Cmab application. However, proliferation potential of HNSCC were not affected by this chemotherapeutic agent. Increased expression of E-cadherin, with decreased expression of N-cadherin and MT1-MMP, were observed after Cmab treatment in vitro to suggest that Cmab may inhibit EMT in HNSCC. Furthermore, inhibition of Tyr 1086 phosphorylation in EGFR, as well as the inactivation of Arf6 coupled with suppression of both GEP100 and AMAP1 expressions were observed by Cmab application. These results suggested that Cmab might have the potential to suppress the activity of EGFR-GEP100-Arf6-AMAP1 pathway. Furthermore, less metastasis of the cancer was observed in the Cmab treatment group compared with control group in vivo.

Conclusions: Our study is the first to provide that Cmab could affect HNSCC through inhibition of migration and invasion of cancer cells, regardless of its anti-proliferative action. EMT inhibition after Cmab application was also clarified in this study. Furthermore, our study suggested that EGFR-GEP100-Arf6-AMAP1 pathway may have some role in the invasion and metastasis of HNSCC. Future studies to further assess the precise mechanism of Cmab against HNSCC are warranted.

Citation Format: Yoshifumi Matsumoto, Hiroyuki Sakurai, Yasunao Kogashiwa, Koichiro Saito. Cetuximab inhibits migration, invasion, metastasis and epithelial-mesenchymal transition but not proliferation via GEP100-Arf6-AMAP1 pathway in head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1605.
Abstract 1611: Epithelial-mesenchymal-epithelial transition induced by long term exposure to TGFB1 creates cellular heterogeneity
Authors: Oliveira Patricia , Carvalho Joana , Rocha Sara , Azevedo Mafalda , Vieira Andre F. , Ferreira Daniel , Mendes Nuno , Reis Ines , Vinagre Joao , Heravi-Moussavi Alireza , Nunes Joana B. , Lima Jorge , Máximo Valdemar , Burleigh Angela , Roskelley Calvin , Paredes Joana , Carneiro Fatima , Huntsman David , Oliveira Carla
Published: July 2016

Reversible and dynamic transitions between epithelial and mesenchymal cellular states (EMT/MET) contribute to cancer progression and dissemination. Whereas EMT facilitates initial steps of tumour cell detachment, MET is likely required for colonization at distant sites. Although MET is generally perceived as mirroring EMT, we hypothesize that MET entails its own set of novel and/or differentially active molecular circuitries, generating cells with features distinct from the original epithelial state.

Using an in vitro TGFβ1-induced EMT/MET model, we demonstrated that MET generates co-existing heterogeneous cell populations (Reverted-Epithelial or RE-cells) with novel phenotypic and functional properties, such as increased self-renewal, in vivo increased tumourigenicity and distinct chemoresistance properties.

Overall, our results indicate that MET is a permissive process, driving cellular plasticity towards heterogeneity and with it, creating novel biological signatures of relevance for cancer growth.

Citation Format: Patricia Oliveira, Joana Carvalho, Sara Rocha, Mafalda Azevedo, Andre F. Vieira, Daniel Ferreira, Nuno Mendes, Ines Reis, Joao Vinagre, Alireza Heravi-Moussavi, Joana B. Nunes, Jorge Lima, Valdemar Máximo, Angela Burleigh, Calvin Roskelley, Joana Paredes, Fatima Carneiro, David Huntsman, Carla Oliveira. Epithelial-mesenchymal-epithelial transition induced by long term exposure to TGFB1 creates cellular heterogeneity. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1611.
Abstract 1612: Overexpression or inducible expression of Snail, Zeb1 or TGFβ recapitulates epithelial-mesenchymal transition (EMT) in colorectal cancer cell lines in vitro
Authors: Bhagwat Shripad V. , Hamm Nicole E. , Hsu Yu-Chih , Qian Yuewei , Wild Robert , Lee Jonathan A. , Peng Sheng-Bin
Published: July 2016

Epithelial-mesenchymal transition (EMT) is one of the hallmarks of cancer and a critical process providing tumor cells with the ability to metastasize to distant sites. Several previous studies have revealed that EMT plays a crucial role in the progression and aggressiveness of colorectal cancer (CRC). Snail, Zeb1 and TGFβ are considered as master EMT genes and their overexpression has been linked to metastatic disease. Our study was conducted to establish an EMT platform in-house to determine the role of Snail, Zeb1 and TGF-β1 in mediating EMT in CRC cell lines in vitro and using them for studying drug sensitivity and target validation. Screening of six CRC cell lines for expression of epithelial (E) and mesenchymal (M) markers by western blot analysis suggested that DLD-1 and HT-29 cells are epithelial in nature and were used to generate stable overexpression and tet-inducible models. Overexpression of Snail or Zeb1 or TGF-β1 induced EMT in both DLD-1 and HT-29 colorectal cancer cells as indicated by downregulation of E-cadherin and upregulation of vimentin by western blot analysis and immunofluorescence staining. These cells which have undergone EMT also showed significant growth advantage in 3D growth on matrigel or soft agar. Stable ‘E’ and ‘M’ cells were also used to test the sensitivity of various inhibitors including erlotinib, salinomycin and chemotherapeutic agents such as paclitaxel, gemcitabine, cisplatin, oxaloplatin and 5-FU. Consistent with previous findings, erlotinib showed sensitivity only in ‘E’ cells and not ‘M’ cells. Chemotherapy agents have also shown higher sensitivity in ‘E’ cells than ‘M’ cells. In contrast, Salinomycin showed equipotent sensitivity in ‘E’ and ‘M’ cells. We have also generated tet-inducible models of Snail, Zeb1 and TGF-β1 and they behaved very similar to overexpression models. These inducible models were useful to determine whether any inhibitor treatment or knock down of specific gene (target) can block EMT. In our studies, testing of a Focal Adhesion Kinase (FAK) inhibitor or Dasatinib (SFK inhibitor) as examples showed blockade of EMT in these models. Overall, establishing several EMT models in-house enabled us to validate new targets involved in EMT, test new inhibitors whether it can block EMT or study drug sensitivity in ‘E’ vs. ‘M’ cells.

Citation Format: Shripad V. Bhagwat, Nicole E. Hamm, Yu-Chih Hsu, Yuewei Qian, Robert Wild, Jonathan A. Lee, Sheng-Bin Peng. Overexpression or inducible expression of Snail, Zeb1 or TGFβ recapitulates epithelial-mesenchymal transition (EMT) in colorectal cancer cell lines in vitro. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1612.
Abstract 1621: SRGAP2 expression levels may induce a biphasic metastatic phenotype in osteosarcoma cell lines
Authors: Marko Tracy , Shamsan Ghaidan , Largaespada David
Published: July 2016

The purpose of this study is to characterize the role of Slit-Robo GTPase-Activating Protein 2 (SRGAP2) in osteosarcoma (OS) metastasis. OS is the most common primary bone tumor and the eighth leading pediatric cancer. Despite combined therapies, treatment failure is experienced within 5 years of diagnosis by over 40% of patients, generally due to metastatic disease. Using the conditional Sleeping Beauty transposon mutagenesis system, our laboratory recently identified candidate tumor promoting genes in transgenic mice that develop OS, including the potential tumor suppressor SRGAP2 involved in regulating actin dynamics. We hypothesized that loss of SRGAP2 would increase the metastatic potential of OS cell lines in vitro and in vivo, whereas gain would decrease metastatic potential. Gene expression was amplified with a stably integrated, tetracycline-inducible over expression vector containing SRGAP2 cDNA and gene silencing was accomplished with a clustered regularly interspaced short palindromic repeat (CRISPR) targeting the gene. Studies were conducted in the well-characterized murine osteosarcoma cell lines K12 and its more aggressive derivative K7M2 and human osteosarcoma cell lines HOS and its more aggressive derivative 143B. Compared to luciferase-controls, overexpression and knockout of SRGAP2 had no effect on cell proliferation in K12, K7M2, HOS, and 143B (n = 4). A reduction of soft agar colony formation was observed in knockout cell lines but not in cell lines with SRGAP2 overexpression for K12 and 143B (n = 3); HOS cell lines did not form colonies in soft agar. Interestingly, overexpression of SRGAP2 decreased wound-healing closure in 143B and K12 lines, but increased closure time in HOS (n = 4). Tail vein injections in NRG mice are currently being investigated. Overexpression of SRGAP2 in K12 decreased development of macrometastases in lungs, whereas knockout of SRGAP2 eliminated gross detection of lung masses (n = 3). Future studies include imaging fixed cells to determine if SRGAP2 knockout and overexpression affects cell morphology and completing studies with K7M2 lines. These results suggest that SRGAP2 has a biphasic phenotype in osteosarcoma cell lines, with an optima in expression for efficient metastasis. It's dual role of deforming cell membranes independent of its ability to activate Rac GTPases and alter actin dynamics may be responsible for the observed results.

Citation Format: Tracy Marko, Ghaidan Shamsan, David Largaespada. SRGAP2 expression levels may induce a biphasic metastatic phenotype in osteosarcoma cell lines. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1621.
Abstract 1637: 22(S)-Hydroxycholesterol, an antagonist of LXR, inhibits breast cancer cell migration
Authors: Hwang Sewon , Na Tae Young , Na Hyelin , Lee Minho , Lee Mi-Ock
Published: July 2016

The Liver X Receptor (LXR) is a well-established ligand-regulated transcription factor involved in cholesterol homeostasis, lipid metabolism, and inflammation. Recent studies have reported a strong antiproliferative effect of LXRs in multiple types of cancer including prostate, colon, lung, and breast cancer. However, little is known about its association with cancer metastasis. Therefore we aimed to investigate the potential of LXR ligands in the context of breast cancer cell migration, and its underlying molecular mechanism. We first performed 2D-migration assay in 4T1 breast cancer cells. Treatment of an LXR antagonist significantly reduced the rate of 4T1 cell migration. However, LXR agonists such as T0901317, GW3965 did not have much effect. Next, we investigated the molecular mechanism of cell migration. Since the degree of invasion and metastasis of breast carcinoma is well correlated with elevated expression of metastasis-associated protein 1 (MTA1), we examined whether MTA1 expression could be regulated by LXR ligands. Interestingly, when LXR agonists were treated, increased protein expression of MTA1 and its downstream target protein HIF-1α was observed in MCF7, MDA-MB-231, and 4T1-Luc breast cancer cell lines. Transient expression of LXRα demonstrated the same results as well. Furthermore, the treat of 22(S)-HC down-regulated MTA1 and HIF-1α protein expressions. Together, our findings indicate that LXR influences migratory pattern of breast cancer cells, which may affect metastatic property of breast cancer cells via LXR-dependent regulation of MTA1 and HIF-1α expression.

Citation Format: Sewon Hwang, Tae Young Na, Hyelin Na, Minho Lee, Mi-Ock Lee. 22(S)-Hydroxycholesterol, an antagonist of LXR, inhibits breast cancer cell migration. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1637.
Abstract 1666: Biomarkers for early detection of radiation nephropathy
Authors: Song Feifei , Jacob Jidhin , Chakravarti Arnab , Jacob Naduparambil K.
Published: July 2016

Purpose/Background: Chronic kidney disease is among the common late effects detected in patients receiving chemotherapy and/or radiotherapy. Currently, there are no biomarkers that allow detection of normal tissue toxicity in late responding organs such as kidney. Developing predictive biomarkers could help identify individuals that are at high risk for close follow-up and prophylactic treatments. Our studies show that miRNAs detectable in cell-free body fluids can be developed as biomarkers of acute radiation syndromes. In the present study, we sought to investigate the potential of serum and urine miRNAs as indicators of radiation induced kidney damage in rodent models.

Methods and Results: An amplification-free hybridization based nCounter assay was optimized for evaluating the changes of miRNAs in body fluids. Comparison of cell-free miRNAs in urine as well as serum, collected from control versus irradiated mice, enabled us to identify candidate biomarkers that are potential indicators of radiation response. Over 40 miRNAs were detectable in urine samples collected from mice and over 80 miRNAs were detectable in serum. Molecules such as miR-1224, miR-804, miR-714 and miR-709 showed significant increase in their urine level after radiation, which peaked 6-8 hours after exposure to acute doses. On the other hand, markers such as miR-378 that are also abundant in urine did not show significant change after radiation, hence serving as an internal control. Comparison of urinary response in mice exposed to 2, 4, 6 and 8 Gy TBI revealed good dose response. Furthermore, the same markers exhibited a dose and time dependent changes following exposure to fractionated myeloablative regimen (6 × 2 Gy, bid) that is commonly used in leukaemia patients, prior to stem cell transplantation. Specifically, two of these biomarkers, miR-714 and miR-1224 exhibited a dose dependent increase in their serum level after fractionated or acute single dose exposure. In-situ hybridization displayed an overall increase in signals of miR-1224 and miR-714 at outer medulla after radiation. Increased signals detected in tubular epithelial cells indicate the possible tubular origin of the urinary miRNAs that are responsive to radiation.

Conclusion: We have developed a panel of miRNAs for non-/minimally invasive detection of radiation response in kidney. Several of the urinary miRNA biomarkers exhibited a dose and time dependent changes, suggesting their potential as biomarkers for non-invasive evaluation of radiation response in organs such as kidney for which early detection of damage is a major challenge.

Citation Format: Feifei Song, Jidhin Jacob, Arnab Chakravarti, Naduparambil K. Jacob. Biomarkers for early detection of radiation nephropathy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1666.
Abstract 1669: Inhibition of the Rac1/PAK pathway sensitizes pancreatic cancer cells to gamma-irradiation
Authors: Ouellette Michel M. , Batra Surinder K. , Yan Ying
Published: July 2016

Radiation therapy is a staple treatment for pancreatic cancers. However, owing to the intrinsic radioresistance of pancreatic cancer cells, radiation therapy often fails to increase survival of pancreatic cancer patients. Radiation impedes cancer cells by inducing DNA damage, which can activate cell cycle checkpoints. Normal cells possess both G1/S and G2/M checkpoints. However, cancer cells are often defective in G1/S checkpoint due to mutations/alterations in the key regulators of this checkpoint. Accordingly, our results show that normal pancreatic ductal cells respond to ionizing radiation (IR) with activation of both checkpoints whereas pancreatic cancer cells respond to IR with G2/M arrest only. Overexpression/hyperactivation of Rac1 GTPase is detected in the majority of pancreatic cancers. Rac1 plays important roles in survival and Ras mediated transformation. Here, we show that Rac1 and its downstream effector, the PAK kinases, also plays a critical role in the response of pancreatic cancer cells to IR. Inhibition of Rac1/PAK pathway with pharmacological inhibitors (Ehop-016, AZA1, NSC23766, and FRAX597) or a dominant negative mutant of Rac1 (Rac1T17N) blocks activation of the ATM/Chk2 and ATR/Chk1 pathways, abrogates activation of the IR-induced G2/M checkpoint, delays the repair of IR-induced double-stranded DNA breaks, and increases the radiosensitivity of pancreatic cancer cells through induction of apoptosis. These results implicate Rac1 signaling in the survival of pancreatic cancer cells following IR, raising the possibility that this pathway contributes to the intrinsic radioresistance of pancreatic cancer.

Citation Format: Michel M. Ouellette, Surinder K. Batra, Ying Yan. Inhibition of the Rac1/PAK pathway sensitizes pancreatic cancer cells to gamma-irradiation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1669.
Abstract 1670: Radiosensitization of glioma cells by the ketone body β-hydroxybutyrate is associated with enhanced cell cycle arrest in the G2/M phase
Authors: Silva-Nichols Helena B. , Rossi Alex P. , Woolf Eric C. , Fairres Marshall J. , Deleyrolle Loic P. , Reynolds Brent A. , Scheck Adrienne C.
Published: July 2016

Glioblastoma multiforme (GBM) is an aggressive primary brain tumor with a 5 year survival rate of 25% in children and less than 10% in adults. Improvement in the prognosis of GBM patients requires the development of new therapeutic approaches. One emerging strategy is to target aberrant cell metabolism, a trait shared by virtually all tumor cells. The ketogenic diet (KD), a high fat, low carbohydrate and protein metabolic therapy has been shown to prolong survival in animal glioma models, and when used in conjunction with radiation cured 9 of 11 mice of their implanted tumors. We have also shown that the KD alters hypoxia, angiogenesis, and other hallmarks of glioma progression. To elucidate the underlying mechanisms through which ketones exert their effects on glioma, we are doing analyses of the effect of β-hydroxybutyrate (βHB), the most prevalent ketone body synthesized during ketosis, on glioma cells in vitro. We found that βHB both alone and in conjunction with radiation significantly inhibits proliferation of human and mouse glioma cells and human glioma stem cells (GSC). Alterations in passage through the cell cycle may affect proliferation, and cells are also more sensitive to radiation in the G2/M cell cycle phase. We therefore analyzed the effect of βHB on cell cycle distribution of cells treated with βHB and/or radiation. An analysis of cell cycle status by flow cytometry demonstrated that treating the GSC line L0 with 5mM βHB in combination with 4 Gy of radiation significantly increased the number of cells in G2/M cell cycle arrest. In GL261-Luc2 mouse glioma cells, 5mM βHB alone significantly enhanced G2/M cell cycle arrest, which could lead to radiosensitization. Currently we are analyzing proteins involved in cell cycle progression and apoptosis to better understand βHB mediated changes in growth and radioresistance. In summary, these data provide insight to the radiosensitization and anti-proliferative mechanisms of βHB and may hold implications for the use of the KD in the treatment of GBM.

Citation Format: Helena B. Silva-Nichols, Alex P. Rossi, Eric C. Woolf, Marshall J. Fairres, Loic P. Deleyrolle, Brent A. Reynolds, Adrienne C. Scheck. Radiosensitization of glioma cells by the ketone body β-hydroxybutyrate is associated with enhanced cell cycle arrest in the G2/M phase. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1670.
Abstract 1721: Desmoplasia stem and progenitor cells within the tumor microenvironment
Authors: Lannagan Tamsin , Woods Susan , Vrbanac Laura , Yang Miao , Ng Jia , Wang Tongtong , Tailor Yagnesh , Asfaha Samuel , Wang Timothy , Worthley Daniel L.
Published: July 2016

All developing and adult organs are supported by connective tissues. We recently demonstrated that Gremlin 1 expressing cells in the bone (osteochondroreticular stem cells) and the bowel (intestinal reticular stem cells) are connective tissue stem cells, during development and healing. The contribution of these stem cells to the desmoplasia surrounding gastrointestinal and skeletal cancers, however, is unknown. In this study we first established that typical markers of bone marrow skeletal stem cells, also identify colony forming unit-fibroblasts (CFU-Fs) in the tumour microenvironment (identified by CD45-Ter-119-CD31-CD1040a+CD105+). Next we tested the local origins of alpha-smooth muscle actin (Acta2) expressing cancer-associated fibroblasts in orthotopic (colonoscopically delivered MC38 and carcinogenesis AOM/DSS) mouse models of colorectal cancer. Using transgenic mouse models to lineage trace and report the connective tissues in the bone and bowel, including Grem1-creERT;R26-LSL-ZsGreen; Acta2-RFP and our Acta2-CreERT line, we found that normal Grem1-expressing and Acta2-expressing cells each contribute to some, but not all, of the reactive cancer-associated fibroblasts surrounding our mouse models of cancer. Whilst, neoplastic cells appear to make a significant contribution to cancer-associated fibroblasts in some other cancers, using an epithelial specific Cre (K19-cre) there was no contribution of epithelium to Acta2-expressing cells in our AOM-DSS colorectal cancer models. We investigated Grem1 and Acta2 derived cells from the tumor microenvironment and found that these cells were clonagenic. Finally, we compared their capacity to support the in vitro growth of colorectal normal and neoplastic organoids compared to other colonic mesenchymal cell types. We are currently examining the role of these cells on expanding intestinal stem cells in normal and neoplastic gastrointestinal glands and examining the secreted factors from these cells that are relevant to tumor initiation and spread.

Citation Format: Tamsin Lannagan, Susan Woods, Laura Vrbanac, Miao Yang, Jia Ng, Tongtong Wang, Yagnesh Tailor, Samuel Asfaha, Timothy Wang, Daniel L. Worthley. Desmoplasia stem and progenitor cells within the tumor microenvironment. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1721.
Abstract 1787A: Puerto Rico BioBank: The first cancer tissue biobank at a US Hispanic-serving institution
Authors: Casbas-Hernandez Patricia , Flores Idhaliz , Seijo Edward , Coppola Domenico , Eschrich Steve , Carvajal-Pelaez Rodrigo , Abac Sonia , Correa Dagmar , Gordian Edna , Munoz-Antonia Teresita
Published: July 2016

There are currently 580 million people worldwide considered to be of Hispanic origin. In the US Hispanics represent 17% of the population and its largest ethnic minority. Funded by NIH, Moffitt Cancer Center (Florida) and Ponce School of Medicine (Puerto Rico) initiated a partnership that conducts high-quality research, training, and community outreach focusing on cancer health disparities among Hispanics. A central component to this partnership is the establishment of the first cancer-focused biobank in the island, the Puerto Rico BioBank (PRBB). The PRBB has actively recruited cancer patients since 2009; over these years we have established essential collaborations and a functional infrastructure. Eligible cancer patients provide informed consent and agree to donate blood samples (for DNA) and solid tissue(fresh-frozen & paraffin embedded). Additionally, patients complete a comprehensive questionnaire related to clinical and lifestyle factors. Biospecimen collection at the PHSU follow standard operating procedures that mirror and often exceed NCI biobaking best practices for biospecimens and ensuring patient data confidentiality. Currently, the PRBB has over 1,100 consented patients (65.8% females, 34.2% males) all of Hispanic origin. The most common banked tumors are Breast, Prostate, Lung and Endometrium, although other tumors are represented. All the information and data are entered into a biospecimen management system (BMS) developed by the partnership, which allows for real-time biospecimen inventory management and reporting functionality. In conclusion, the Puerto Rican patient samples banked in the PRBB are a unique resource that can support multiple molecular and population studies. Also, a Hispanic-specific biobank can foster collaborations among local and international researchers that may facilitate the application of novel molecular techniques to solving cancer health disparities among Hispanics.

Citation Format: Patricia Casbas-Hernandez, Idhaliz Flores, Edward Seijo, Domenico Coppola, Steve Eschrich, Rodrigo Carvajal-Pelaez, Sonia Abac, Dagmar Correa, Edna Gordian, Teresita Munoz-Antonia. Puerto Rico BioBank: The first cancer tissue biobank at a US Hispanic-serving institution. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1787A.
Abstract 1796A: Race and gender differences in lung cancer: examining the effect of smoking history and depression on hospitalization costs
Authors: Husaini Baqar A. , Cain Van A. , Levine Robert S.
Published: July 2016

Objective: Incidence rates of lung cancer (LC) are reported to have declined in the nation. However, the role of depression and tobacco history relative to hospitalization cost for LC remains unknown. Tennessee, being a tobacco producing State, provides an opportunity to examine two issues: (i) Prevalence of LC, depression, and history of tobacco use among LC patients by race and gender; (ii) Effect of depression and smoking history on hospitalization costs by sub-groups of LC patients.

Methods: We extracted data pertaining to depression, smoking history, and demographics on patients discharged with all lung cancer (adenocarcinoma, ICD-9 codes 160-165) from the 2008 Tennessee Hospital Discharge Data System (HDDS). The sample (n = 6,665) had patients that were mostly white (86%) and male (57%), with an average age of 67 years. We computed age-adjusted LC rates for race and gender (per CDC methodology), and compared the costs for LC patients with depression/ smoking history with LC patients without depression/smoking history.

Results: LC rates (per 100K) were higher among blacks than whites (146.6 vs. 131.6, p<.000), and higher among male than female patients (174.9 vs. 118.0, p<.00). While nearly 40% of LC patients had a smoking history (more males than females had a history with no racial variation), 25% had depression (more females and whites were depressed). Further, the total hospitalization cost for 2008 was 50% higher for LC patients with depression plus smoking history compared to peers without depression/smoking history ($122,500 vs. 80,522, p<.000).

Conclusion: LC rates are higher among blacks and males who also have more smoking history. Depression is higher among females and whites with LC. Further, both depression and smoking history adds significantly to the hospitalization costs. These results point to: (i) costs savings might be realized by treating depression first among the LC patients, and (ii) population-based smoking cessation programs need to be vigorously implemented to reduce lung cancer and associated co-morbidities.

___________________

This presentation at the Eight AACR annual Conference, New Orleans, April 16-20, 2016, was partially supported by grants from CDC #U58CCU422782, a sub-contract #ED-07-20811-09, and a NCI/NIH grant (5U54CA163066) to Tennessee State University, B. Husaini, PI.

Citation Format: Baqar A. Husaini, Van A. Cain, Robert S. Levine. Race and gender differences in lung cancer: examining the effect of smoking history and depression on hospitalization costs. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1796A.
Abstract 1816: Alpha lipoic acid inhibits proliferation and epithelial mesenchymal transition of thyroid cancer cells
Authors: Kwon Hyemi , Jeon Min Ji , Kim Won Gu , Lim Seonhee , Sim Soyoung , Kim Tae Yong , Shong Young Kee , Kim Won Bae
Published: July 2016

The short-chain fatty acid, α-lipoic acid (ALA) is a powerful antioxidant used for treatment of diabetic neuropathy. Recent studies suggested the possibility of ALA as a potential anti-cancer agent, because it could activate adenosine monophosphate activated protein kinase (AMPK) and inhibit transforming growth factor-β (TGFβ) pathway. We evaluate the effects of ALA on thyroid cancer cell proliferation, migration, and invasion. We performed in vitro cell proliferation analysis with BCPAP, HTH-83, CAL-62, and FTC-133 cells. ALA suppressed cell proliferation through activation of AMPK and subsequent down-regulation of mammalian target of rapamycin (mTOR)-S6 signaling pathway. Low-dose ALA, which had minimal effects on cell proliferation, also decreased cell migration and invasion of BCPAP, CAL-62, and HTH-83 cells. ALA inhibited epithelial mesenchymal transition (EMT) evidently by increase of E-cadherin and decreases of activated β-catenin, vimentin, snail, and twist in these cells. ALA suppressed TGFβ production and inhibited induction of p-Smad2, and twist by TGFβ1 or TGFβ2. These findings indicate that ALA reduces thyroid cancer cell migration and invasion through suppression of TGFβ production and inhibition of TGFβ signaling pathways. ALA also significantly suppressed tumor growth in mouse xenograft model using BCPAP and FTC-133 cells. This is the first study to show anti-cancer effect of ALA on thyroid cancer cells. ALA could be a potential therapeutic agent for advanced thyroid cancer, as an adjuvant therapy with other systemic therapeutic agents.

Citation Format: Hyemi Kwon, Min Ji Jeon, Won Gu Kim, Seonhee Lim, Soyoung Sim, Tae Yong Kim, Young Kee Shong, Won Bae Kim. Alpha lipoic acid inhibits proliferation and epithelial mesenchymal transition of thyroid cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1816.
Abstract 1834: Semaphorin 3C is an androgen receptor-regulated gene
Authors: Tam Kevin J. , Dalal Kush , Hsing Michael , Cheng Chi Wing , Chiang Yan Ting , Sharma Aishwariya , Peacock James W. , Cherkasov Artem , Wang Yuzhuo , Gleave Martin E. , Rennie Paul S. , Ong Christopher J.
Published: July 2016

Prostate cancer (PCa) is the second leading cause of cancer-related deaths in North America. The androgen receptor (AR) is a member of the nuclear receptor superfamily of transcription factors and is heavily implicated in PCa progression. First-line therapies frequently target the AR axis and are initially met with favourable response but restored and aberrant AR signaling fuel disease progression to stages for which treatment is palliative. Transcriptional targets of the AR include genes involved in cell growth and cell fate but are not completely described. The semaphorin family of signaling proteins is a large grouping of cell-surface or secreted signaling proteins that function in neurogenesis and development. The roles of semaphorins in cancer are becoming increasingly evident however mechanistic details surrounding their involvement in cancer are poorly defined. One member of the class 3 semaphorins, SEMA3C, has been shown to confer invasive phenotypes in prostate cancer cells. Using the AR-positive LNCaP cell line we show that SEMA3C is an androgen-responsive gene. Additionally, using RSAT DNA analysis software we identify an androgen response element (ARE) in intron 2 of SEMA3C and show that AR is recruited to this genomic region in an androgen-dependent manner in chromatin immunoprecipitation assays. Furthermore, the isolated ARE binds to the AR-DNA binding domain in gel shift assays and can be transactivated by AR in reporter gene assays. Finally we show that the pioneering factor, GATA2, is necessary for AR-mediated expression of SEMA3C. Collectively, our work identifies SEMA3C as a direct transcriptional target of AR in support of our hypothesis that dysregulated AR signaling drives inadvertent upregulation of SEMA3C and PCa disease progression. Deregulated AR signaling underpins prostate cancer progression and underscores the need to elucidate transcriptional targets of AR. Identification of SEMA3C as a novel target of AR provides the rationale for targeted therapies directed against SEMA3C.

Citation Format: Kevin J. Tam, Kush Dalal, Michael Hsing, Chi Wing Cheng, Yan Ting Chiang, Aishwariya Sharma, James W. Peacock, Artem Cherkasov, Yuzhuo Wang, Martin E. Gleave, Paul S. Rennie, Christopher J. Ong. Semaphorin 3C is an androgen receptor-regulated gene. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1834.
Abstract 1852: Multiple PI3K pathway mutations predominate in low stage endometrial carcinomas
Authors: Roque Dario R. , Jeck Will R. , Hayes David N. , Dizon Arthur M. , Clark Leslie , Pierce Stuart , Wysham Weiya Z. , Castellano Tara , Gehrig Paola A. , Bae-Jump Victoria
Published: July 2016

Objectives: Endometrial cancers (ECs) frequently harbor mutations in PI3K pathway genes. Our objective was to determine the mutation frequency of the PIK3 pathway in the tumors of EC patients prospectively enrolled on an IRB-approved institutional tumor sequencing initiative (UNCseq) and correlate these with clinical factors.

Methods: Snap-frozen and FFPE tissue samples were collected from patients enrolled on UNCseq (NCT01457196). DNA was isolated using the Puregene DNA purification system, and Illumina libraries were prepared separately from tumor and a matched normal sample from each patient. Relevant targets, were enriched by a custom designed Agilent SureSelect hybrid capture enrichment library using standard protocols. Samples were sequenced on Illumina HiSeq machines in a variety of formats. Statistical analysis of clinical correlates was performed in R (v 3.1.1).

Results: Data was collected from 109 EC patients. Thirty-six tumors (33.0%), 34 of which were endometrioid, had >2 mutations between PIK3CA and PIK3R1. 20 patients had multiple PIK3CA mutations (18.3%) and 11 had multiple PIK3R1 mutations (10.1%). In all but 5 cases, multiple mutations of PIK3R1 or PIK3CA were coincident with PTEN mutation (p = 0.018). There were strong correlations between PI3K pathway mutations and tumor grade and stage. High stage tumors (stage >2) were less likely (5/36) than stage 1 tumors (31/73) to have multiple PI3K mutations (p = 0.0056). Though not reaching significance, grade 3 tumors (8/37) were less likely than low-grade tumors (28/72) to demonstrate multiple PI3K mutations (p = 0.11). Of the 10 serous ECs, none exhibited multiple PI3K mutations.

Conclusions: There is a strong relationship between mutated PIK3 pathway genes and clinically relevant tumor biology in ECs. Multiple mutations in the PIK3 pathway are common, suggesting that PI3K pathway inhibition in EC may need to be directed against PIK3CA and PIK3R1 simultaneously. These multiply mutated tumors are strongly linked to lower stage and grade tumors with concurrent PTEN mutations. We posit that initially PTEN mutant clones may give rise to subclonal populations with various PI3K mutations which may be relatively indolent until additional driver mutations are acquired such that one subpopulation predominates, resulting in higher grade and stage ECs.

Citation Format: Dario R. Roque, Will R. Jeck, David N. Hayes, Arthur M. Dizon, Leslie Clark, Stuart Pierce, Weiya Z. Wysham, Tara Castellano, Paola A. Gehrig, Victoria Bae-Jump. Multiple PI3K pathway mutations predominate in low stage endometrial carcinomas. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1852.