bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2835: Potential opposing roles of AKT isoforms in indolent versus aggressive prostate cancer
Authors: Miller Karina A. , Ko Hyun-Kyung , Gelman Irwin H.
Published: July 2017

Prostate cancer (CaP) is the most commonly diagnosed non-cutaneous cancer and the second highest contributor to cancer-related deaths in U.S. men. Localized CaP has a 5-year survival rate of approximately 100%, but disseminated, metastatic disease (mCaP) dramatically reduces 5-year survival to <30%. A known driving force in the progression of CaP is activation of the PI3K/Akt signaling pathway through loss of PTEN, with widespread effects on cell proliferation and migration. Additional genomic changes, such as the loss of TP53 or RB1, or the upregulation of MYC, correlate with increased incidence and aggressiveness of mCaP. However, only a fraction of men with high levels of circulating and disseminated CaP cells progress to overt, macro-metastatic disease - the lethal phenotype in CaP. Importantly, little is known regarding the drivers of indolent vs. aggressive mCaP. We used two transgenic (Tg) mouse models of mCaP with clinically relevant genetic alterations which exhibit Akt activation and Rb1 loss, yet one produces indolent mCaP and the other, systemic aggressive mCaP. Specifically, mice lacking Rb1 and the metastasis-suppressor, SSeCKS/Akap12, develop high-grade prostatic intraepithelial neoplasia (HG-PIN) and disseminated disease in the lymph nodes whereas those lacking Pten and Rb1 develop CaP and aggressive mCaP. The metastasis-suppressing functions of Akap12 relates to its ability to scaffold Src and PKC, thereby attenuating their oncogenic signaling pathways. We will show data suggesting that the pathological differences between these two Tg models is based on the differential use of PI3K-p110 and Akt isoforms, with aggressiveness correlating with the downregulation of Smad4, a known metastasis-suppressor in Tg CaP models. Additionally, differences in Akt isoform usage likely controls the expression of neurogenesis genes that are especially upregulated in castration-recurrent CaP that fails second-line androgen receptor antagonist inhibitors such as enzalutamide. By comparing the differential transcriptomes and signaling networks in primary-site tumors, lymph node metastases, and CaP cell lines derived from these two Tg models, several new potential therapeutic targets have been identified that could be exploited to prevent or treat aggressive mCaP.

Citation Format: Karina A. Miller, Hyun-Kyung Ko, Irwin H. Gelman. Potential opposing roles of AKT isoforms in indolent versus aggressive prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2835. doi:10.1158/1538-7445.AM2017-2835
Abstract 2839: Systematic enrichment analysis of gene expression profiling studies identifies SPARC dependent consensus pathways implicated in bladder cancer
Authors: John Bincy Anu , Said Neveen
Published: July 2017

Bladder cancer (urothelial cancer of the bladder) is the most common malignancy affecting the urinary system with increasing incidence and mortality. Treatment of bladder cancer has not advanced in the past 30 years. Therefore, there is a crucial unmet need for novel therapies, especially for advanced disease. We have recently reported Secreted Protein Acidic and Rich in Cysteine (SPARC) as a tumor suppressor in urinary bladder cancer that inhibits the multistep cascades on tumor initiation, progression and metastasis. SPARC gene and protein expression was among candidates associated with the tumorigenicity of the isogenic T24/T24t cell lines. We reported that SPARC depletion in human bladder cancer cell lines including T24 cells increased their tumorigenicity and metastatic potential. In addition, SPARC protein and transcript expression are significantly downregulated in advanced urothelial cancer. To gain insight on the molecular mechanisms of the tumor suppressor effects of SPARC in urothelial cancer, we did whole transcriptome profiling of T24 cells depleted of SPARC to identify SPARC-signature associated with bladder cancer invasiveness, progression, and metastasis. Subsequently, we used gene signature enrichment analysis (GSEA) pathway enrichment tools to define functionally related genes that are consistently up- or down- regulated as a function of loss of SPARC. We found that loss of SPARC expression is associated with enrichment of multiple oncogenic signaling pathways that are enriched in muscle invasive urothelial cancer and have been associated with poor prognosis. These pathways include K-ras, Myc-oncogene, p53 pathways as well as DNA damage/repair. Consistent with our earlier reports, loss of SPARC is associated with genes and proteins involved in angiogenesis, inflammation and hypoxia. In addition, we have identified novel signatures involved in unfolded protein response, mTOR signaling, glycolysis and cholesterol metabolism. These comprehensive signatures not only reveal SPARC-dependent networks that cooperate to elicit its biological responses but enables coherent understanding of the etiology of complex bladder cancer disease. Importantly, these signatures identify novel therapeutic opportunities for bladder cancer.

Citation Format: Bincy Anu John, Neveen Said. Systematic enrichment analysis of gene expression profiling studies identifies SPARC dependent consensus pathways implicated in bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2839. doi:10.1158/1538-7445.AM2017-2839
Abstract 2843: DNMT3B mediated DNA methylation and epigenetic reprogramming of metastatic cancer cells
Authors: So Jae Young , Skrypek Nicolas , Wang Xiang , Merchant Anand , Yang Howard , Chen Wei-Dong , Hu Gangqing , Achyut Bhagelu R , Cam Meggie , Zhao Keji , Lee Maxwell , Yang Li
Published: July 2017

Approximately 90% of cancer patients die from metastasis. In many cases, current therapies are designed based on the primary tumor characterization and are ineffective against metastatic disease. It is not clear whether metastatic cancer cells acquire additional genetic and epigenetic alterations, if so, what are the underlying mechanisms. Using several tumor models, we demonstrated that DNMT3B, de nova DNA methyltransferase, was increased in metastatic nodules in comparison to that from the primary tumors. DNMT3B knockdown or overexpression significantly inhibited or increased metastatic colonization of cancer cells. To understand the underlying molecular mechanisms of DNMT3B regulation, we performed DNMT3B ChIP-seq, RNA-seq, and DNA methylation-seq comparing lung metastases with primary tumors and 4T1 cells. We identified genes that are differentially methylated and expressed. Ingenuity Pathway Analysis revealed DNMT3B targeting multiple oncogenic signaling pathways. Bioinformatics analysis of human databases demonstrated significantly higher expression levels of DNMT3B in metastases than primary tumors in breast, prostate and melanoma cancer patients. In summary, our study demonstrated that DNMT3B as a key epigenetic regulator which plays critical roles for tumor metastasis. Our work suggests DNMT3B as potential therapeutic targets for breast cancer patients with metastatic disease.

Citation Format: Jae Young So, Nicolas Skrypek, Xiang Wang, Anand Merchant, Howard Yang, Wei-Dong Chen, Gangqing Hu, Bhagelu R Achyut, Meggie Cam, Keji Zhao, Maxwell Lee, Li Yang. DNMT3B mediated DNA methylation and epigenetic reprogramming of metastatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2843. doi:10.1158/1538-7445.AM2017-2843
Abstract 2845: A Rb phosphorylation code associated with lung cancer metastasis
Authors: Perez-Morales Jaileene , Mejias-Morales Darielys , Torres-Collazo Bryan , Negron-Pagan Harry , Santiago-Cardona Pedro
Published: July 2017

Lung cancer is characterized by its poor prognosis, aggressiveness, and proclivity for early metastasis. Non-small cell lung cancer (NSCLC) it’s the most common type of lung cancer with a five-year survival rate of 18%. Most predictors of metastasis and recurrence of NSCLC rely on post-resection evaluation of tumor histology, which is a severe limitation since only 15% of the patients are diagnosed with resectable disease. Hence, there is a need to characterize biomarkers with metastasis-predicting value in pre-resection small biopsy specimens. In addition to the proclivity for metastasis, another feature of lung cancers is the inactivation of the retinoblastoma protein (Rb). The retinoblastoma protein (Rb) is a tumor suppressor inactivated due to hyper-phosphorylation in most human cancers, including NSCLC. Our preliminary data relates the Rb S249/T821 phosphorylation signature to an epithelial-to-mesenchymal transition (EMT), a trait strongly associated to metastasis. We found that cells that have hyperphosphorylated Rb in residues S249/T821 express EMT markers such as decreased expression of E-cadherin and integrin α5 as well as increased expression of N-cadherin, Vimentin, and p-FAK. We propose to focus on the cell adhesion and migration-related kinase Cdk5 with its activator p39 as the kinase responsible for engendering the Rb S249/T821 phosphorylation signature. Our hypothesis is that Rb phosphorylation in S249 and T821 due to CDK5 activity can have prognostic value by being associated with a metastatic phenotype and EMT. Studies performed in a tissue microarray in a population of NSCLC adenocarcinoma that had undergone EMT found an up-regulation in p39 and that its expression is correlated with metastasis. Knockdown of CDK5 induced a decrease in phosphorylation of Rb S249/T821 with a decrease in E-cadherin expression. These data suggest that CDK5-dependent phosphorylation of Rb can affect cell adhesion by regulating E-cadherin. Introducing p39 into Rb hypo-phosphorylated cell line induced an increase in phosphorylation of Rb residues. Furthermore, the CDK5-p39-Rb axis might point to the explanation and prediction of the metastatic phenotype in lung cancer.

Citation Format: Jaileene Perez-Morales, Darielys Mejias-Morales, Bryan Torres-Collazo, Harry Negron-Pagan, Pedro Santiago-Cardona. A Rb phosphorylation code associated with lung cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2845. doi:10.1158/1538-7445.AM2017-2845
Abstract 2850: A systems genetics approach reveals Rnaseh2c-immune response axis that affects metastasis severity in breast cancer
Authors: Deasy Sarah , Hunter Kent
Published: July 2017

Metastatic breast cancer is a devastating disease with a 5-year survival rate of only 26%. This is due to a lack of effective therapies against established metastases and an inability to identify high risk patients who would benefit from specific adjuvant therapies to prevent metastatic progression. We have shown in mouse models that spontaneously arising tumors metastasize with different severity based on the mouse genetic background. Using systems genetics approaches we have identified genes correlated with metastasis and survival in both mice and humans. Rnaseh2c was identified as a novel candidate metastasis susceptibility gene. This gene encodes a scaffolding subunit of the Ribonuclease H2 enzyme which removes ribonucleotides misincorporated into the DNA. Experimentally modulating Rnaseh2c expression in a murine mammary cancer cell line resulted in significant changes in pulmonary metastasis, confirming this gene as a metastasis modifier. Mutations in Rnaseh2c are known to cause Aicardi-Goutieres Syndrome, a neurological autoinflammatory disorder that overlaps clinically with congenital viral infections and the autoimmune disease Systemic Lupus Erythematosus. Given this, we hypothesized that altered expression of Rnaseh2c in breast cancer cells affects metastasis by engaging the immune system. To investigate immune system involvement, we analyzed metastasis in immunocompromised mice. T cell deficiency ablated the effect of reduced Rnaseh2c expression on metastasis, revealing for the first time an Rnaseh2c-immune response axis in metastasis. Gene ontology pathway analysis following mRNA-sequencing of Rnaseh2c knockdown and overexpression tumors revealed that 20% of the genes with altered expression are involved in immune system-related pathways, including T cell signaling and antigen presentation. Furthermore, genes with significant changes included Type I interferons, T cell markers, and immune regulators. These results confirm that Rnaseh2c is a novel metastasis modifier gene and validate our hypothesis that the immune system is mediating the effect of Rnaseh2c on metastasis. This mechanism highlights a potential new target for combination with immune modulatory therapies to combat this devastating disease and adds to a panel of genes we identified that together could determine patients with high risk for metastasis.

Citation Format: Sarah Deasy, Kent Hunter. A systems genetics approach reveals Rnaseh2c-immune response axis that affects metastasis severity in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2850. doi:10.1158/1538-7445.AM2017-2850
Abstract 286: Forecast of the incidence and etiology of liver cancer in Taiwan, Japan, United States, and United Kingdom: toward harmonization of East and West
Authors: Hsiue Emily Han-Chung H. , Lo Wei-Cheng , Lin Hsien-Ho , Hsu Chih-Hung , Cheng Ann-Lii
Published: July 2017

Background The global epidemiology of primary liver cancer (PLC), primarily hepatocellular carcinoma (HCC), has evolved significantly in the past decades because of improved control of viral hepatitis and the growing prevalence of metabolic factors. We conducted a quantitative forecast of the incidence and etiology of PLC. Methods Incidence rates of PLC were projected in two endemic Asian countries (Taiwan and Japan) and two Western countries (the United States and United Kingdom) with rigorous cancer registry. The annual incidence of PLC (ICD-10 C22.0) between 1980 and 2013 were obtained from the Taiwan Cancer Registry Database, the Japan National Cancer Center, the US SEER 9 database, Cancer Research UK, and the European Network of Cancer Registry. Incidence rates were projected to year 2035 by an age-period-cohort model with a power link function. The population attributable fractions (PAF) of chronic hepatitis B (HBV), chronic hepatitis C (HCV), alcohol consumption, obesity, and diabetes mellitus (DM) for HCC in Taiwan were projected to 2045. The prevalence of each risk factor was obtained from national surveys and projected inferentially by using a log-linear model or simple linear assumption. The relative risk of each factor was derived from pooled literature data. Results From 2013 to 2035, incidence rates of PLC in Taiwan are estimated to decrease by more than 50% in both men (49.3 to 24.2/100,000) and women (19.7 to 9.2/100,000). In Japan, incidence rates have plateaued in the 1990s, and are expected to continue to decline to 17.0/100,000 for men and 6.3/100,000 for women. Conversely, rates in the UK are projected to increase by more than 30% in both men (13.5 to 18.2/100,000) and women (6.0 to 8.1/100,000). A more modest increase is expected in the US, from 10.2 to 12.5/100,000 for men and 3.3 to 3.5/100,000 for women. In Taiwan, the PAF of HBV, the predominant risk factor of HCC, is predicted to decrease from 54.3% in 2015 to 34.4% in 2045. By 2045, the PAFs of obesity and DM are estimated to reach 11.9% and 15.4%, respectively, the latter similar to that of HCV (15.0%). Conclusion PLC incidence rates are forecast to follow a trend of convergence in four representative countries. Metabolic factors are expected to play increasingly important etiologic role in HCC even in regions currently endemic for viral hepatitis.

Citation Format: Emily Han-Chung H. Hsiue, Wei-Cheng Lo, Hsien-Ho Lin, Chih-Hung Hsu, Ann-Lii Cheng. Forecast of the incidence and etiology of liver cancer in Taiwan, Japan, United States, and United Kingdom: toward harmonization of East and West [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 286. doi:10.1158/1538-7445.AM2017-286
Abstract 2860: 89Zr-trastuzumab immunoPET imaging to monitor src status after treatment in HER2 breast cancer
Authors: McKnight Brooke N. , Viola-Villegas Nerissa T.
Published: July 2017

Around 30% of patients with early stage breast cancer have recurrent disease due to resistance. One of the putative causes of acquired resistance can be attributed to the hyperactivation of Src kinases, which are particularly stabilized by aberrant HER2 signaling, which itself is overexpressed in nearly 30% of early stage breast cancers. HER2 downstream effectors include Src, thus, we aim to investigate the use of a HER2-specific monoclonal antibody positron emission tomography (PET) probe, 89Zr-trastuzumab, to monitor Src therapy via surrogate HER2 expression. We hypothesize that 89Zr-trastuzumab can be a surrogate imaging tool for monitoring Src treatment.

89Zr-trastuzumab was previously developed and has demonstrated excellent specificity for breast cancer. Dasatinib-treated HER2+ BT474 (IC50 ~ 1.3 μM), SK-BR-3 (IC50 ~ 5.5 µM), and JIMT-1 (IC50 ~ 8 μM) breast cancer cells lines have shown a negative correlation between treatment and HER2. We next conducted tumorigenic studies using athymic nu/nu mice bearing JIMT-1 or BT474 xenografts, which were treated for 7 or 14 days with dasatinib (75 mg/kg/day). At the end of each treatment, the tumors were subsequently imaged with 18F-FDG, and then followed by 89Zr-trastuzumab, 24 h later. Images were analyzed using AsiPro (show version here and decay-corrected to the time of injection. Tumor uptake values were measured by drawing volumes-of-interest, expressed as % injected dose per gram (%ID/g) of tissue on regions showing the most binding. 18F-FDG did not demonstrate a predictive response in both treated and placebo tumors, whereas, HER2 PET was able to show differential response in treated vs. control cohorts.  In JIMT-1 mice imaged with 89Zr-trastuzumab, a two-fold difference (p < 0.01) was observed between untreated and both treated groups (8.0 ± 1.5 %ID/g, n= 7 vs. 7-day treated: 3.8 ± 1.5 %ID/g, n=4, and 14-day-treated: 4.5 ± 1.3 %ID/g, n= 4) mice imaged with 89Zr-trastuzumab. Confirmatory ex vivo western blots of JIMT-1 tumors have shown a decrease in HER2 as treatment time increases, with a decrease in p-Src (Y-416). In vivo studies with BT-474 xenografts are currently underway.  Immunohistochemistry on excised tumors, as well as treatment on a metastatic patient-derived xenograft model is currently in progress.     

We have shown that HER2 PET can potentially be a surrogate marker of Src treatment. The findings from this study potentially afford a powerful tool to non-invasively detect and monitor changes in Src-targeted therapy in man at the early phases of treatment.

Citation Format: Brooke N. McKnight, Nerissa T. Viola-Villegas. 89Zr-trastuzumab immunoPET imaging to monitor src status after treatment in HER2 breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2860. doi:10.1158/1538-7445.AM2017-2860
Abstract 2872: Quantitative mass spectrometry imaging of erlotinib in skin rashes of cancer patients receiving erlotinib
Authors: Nishimura Meiko , Aikawa Hiroaki , Hayashi Mitsuhiro , Mizutani Yu , Takenaka Kei , Imamura Yoshinori , Chayahara Naoko , Toyoda Masanori , Kiyota Naomi , Mukohara Toru , Hamada Akinobu , Minami Hironobu
Published: July 2017

Background

The development of rashes is the most common adverse event observed in cancer patients treated with epidermal growth factor receptor-targeted tyrosine kinase inhibitors (EGFR-TKI) such as erlotinib. A significant relationship exists between the severity of a rash and survival in various cancers. However, whether erlotinib becomes distributed to the skin and whether its concentration is higher in a rash than in normal skin of treated cancer patients remains unknown. Here, using quantitative mass spectrometry imaging (qMSI), we successfully visualized the distribution of erlotinib in rashes and normal skin of patients with advanced pancreatic cancer receiving this drug.

Methods

We studied five patients with advanced pancreatic cancer who developed rashes after treatment with gemcitabine (1000 mg/m² by intravenous infusion for 30 minutes on days 1, 8, and 15 every 4 weeks) and erlotinib (given orally at 100 mg/day). We biopsied both rashes and normal skin, and compared the distribution of erlotinib using matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI). The plasma concentration of erlotinib was measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Results

Erlotinib concentrations in five patients were 2.55 ± 1.46 ng/mm3 in normal skin and 3.18 ± 1.53 ng/mm3 (mean ± SD) in rashes (p=0.123). In four out of five patients, the erlotinib concentration in rashes was higher than that in normal skin. The epidermis showed the strongest expression of EGFR in skin as judged by immunohistological staining. Erlotinib showed a greater tendency for distribution to the epidermis than subcutaneous

tissue. There was no correlation between erlotinib plasma concentrations vs. concentrations in rashes or normal skin.

Conclusions

Using qMSI, we, for the first time, visualized the distribution of erlotinib in skin tissue of pancreatic cancer patients receiving erlotinib. We found a tendency for a higher concentration of erlotinib in rashes than in normal skin. A greater distribution of erlotinib to the epidermis than subcutaneous tissue suggests erlotinib may directly bind EGFR expressed in the epidermis.

Citation Format: Meiko Nishimura, Hiroaki Aikawa, Mitsuhiro Hayashi, Yu Mizutani, Kei Takenaka, Yoshinori Imamura, Naoko Chayahara, Masanori Toyoda, Naomi Kiyota, Toru Mukohara, Akinobu Hamada, Hironobu Minami. Quantitative mass spectrometry imaging of erlotinib in skin rashes of cancer patients receiving erlotinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2872. doi:10.1158/1538-7445.AM2017-2872
Abstract 2876: Loss of the stem cell and basal lineage regulator LBH delays onset of basal-like triple negative breast cancer
Authors: Ashad-Bishop Kilan C. , Briegel Karoline
Published: July 2017

There is increasing evidence that basal-like triple negative breast cancer (TNBC) originates from luminal mammary epithelial cells. Specific gene signatures have already been experimentally proven to serve as genetic lineage switches that, when overexpressed, transform pre-malignant luminal cells to oncogenic cells with basal, stem-like characteristics. Conversely, depletion of these genes in oncogenic cells with basal, stem-like characteristics leads to luminal differentiation. These studies suggest that during the earliest steps of neoplastic transformation, specific gene sets can alter cell fate decisions and differentiation status in mammary epithelial cells, which ultimately contributes to the heterogeneity of breast tumors.

Our lab has identified a novel Wnt/β-Catenin target gene, Limb bud and heart (LBH) that is majorly overexpressed in TNBC. LBH is a regulator of the basal mammary stem cell lineage and repressor of luminal differentiation via induction of ΔNp63 and repression of estrogen receptor alpha. LBH is required for the self-renewal and maintenance of adult basal mammary stem cells, which tend to be enriched in TNBC. Knockout studies in mice have shown that genetic ablation of LBH does not impair embryogenesis or normal adult organ function, making it a possible therapeutic target.

Using crosses between MMTV-Wnt-1 transgenic mice and K14Cre LBHloxP knockout mice, we are studying the effect of LBH ablation in the basal cells of the mammary epithelium downstream of ectopic Wnt expression in the mammary gland. We postulated that LBH may be an effector of Wnt-driven TNBC, therefore its inhibition would lead to decreased Wnt-induced mammary gland hyperplasia and tumor formation. In our model, LBH ablation in the basal mammary epithelium of female Wnt transgenic mice reduces mammary gland hyperplasia and delays tumor onset. MMTV-Wnt-1 driven, LBH-null tumors also exhibit histopathological differences indicative of a luminal to basal conversion.

There is an urgent need to elucidate mechanisms underlying TNBC development and progression and find reliable avenues for treatment. Our data indicates a role for Lbh as a novel effector for Wnt-driven TNBC and further studies may prove antagonism of Lbh to be a novel method to control TNBC progression.

Citation Format: Kilan C. Ashad-Bishop, Karoline Briegel. Loss of the stem cell and basal lineage regulator LBH delays onset of basal-like triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2876. doi:10.1158/1538-7445.AM2017-2876
Abstract 288: Loss of a branched actin checkpoint in cancer cells
Authors: Molinie Nicolas , Rubtsova Svetlana , Gautreau Alexis
Published: July 2017

Cell proliferation depends on multiple signals, such as growth factors, adhesion to the substratum and to neighboring cells. Cancer cells proliferate independently of these signals. The same stimuli also induce actin polymerization. Here we investigate whether the actin cytoskeleton plays a role in transmitting the proliferation signal. We found that inactivation of the Arp2/3 complex by either a chemical inhibitor or by siRNAs blocks S phase entry in untransformed human breast cell lines and in primary breast epithelial cells. In contrast, breast cancer cell lines did not respond to Arp2/3 inhibition. Inactivating the tumor suppressor p21WAF1/CIP1, or Rb, converts sensitive cells into unresponsive cells further highlighting that this response to Arp2/3 inactivation is at the heart of the transformation process. The depletion of the WAVE complex, the Arp2/3 activator that generates branched actin in lamellipodia, but not of other Arp2/3 activators, blocks cell cycle progression. Conversely, activation of WAVE by active Rac, or depletion of Arpin, which antagonizes WAVE, potentiates cell cycle progression. Together, these results show that branched actin networks generated in lamellipodia are sensed and convey an essential signal for S Phase entry. The signal that branched actin delivers integrates stimulation from soluble growth factor with mechanotransduction from cell adhesions to the substratum and to neighboring cells. This signaling pathway qualifies as a checkpoint, which is required in normal cells, but lost in transformed cells, that monitors the integrity of branched actin networks and instructs the cell as a response that the required conditions to proliferate are fulfilled.

Citation Format: Nicolas Molinie, Svetlana Rubtsova, Alexis Gautreau. Loss of a branched actin checkpoint in cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 288. doi:10.1158/1538-7445.AM2017-288
Abstract 2882: The miR-200b-ZEB1 circuit regulates diverse stemness of human hepatocellular carcinoma
Authors: Hsieh Sen-Yung , Tsai Su-Chun
Published: July 2017

Background & aims: Hepatocellular carcinoma (HCC) can be derived from cancer stem cells (CSCs), which contribute to tumor initiation, metastasis, chemoresistance, and post-treatment recurrence. A great variety of HCC CSCs resulting in diverse clinical manifestations have been reported. We aimed to elucidate how CSC diversity is regulated.

Methods: MicroRNAs deregulated in HCC were identified by using array-based microRNA profiling. Diversity of HCC CSCs was assayed by flow-cytometry, in vitro and in vivo assays for tumorigenicity.

Results: MiR-200b downregulation occurred in early HCC and associated with shorter disease-free and overall survival. Ectopic expression of miR-200b or silencing of ZEB1 led to a decrease in CD13+ and CD24+ HCC CSCs and an increase in EpCAM+ HCC CSCs. MiR-200b directly suppressed BMI1 and ZEB1 expressions. ZEB1 transcriptionally upregulated CD13 and CD24 expression and downregulated EpCAM expression via directly targeting their promoters. Neither miR-200b nor ZEB1 had obvious effects on CD133 or CD90 expression. Silencing CD13 or CD24 expression suppressed tumorigenicity of HCC cells. Ectopic expression of CD24 reversed the suppression of tumorigenicity when these HCC cells had been ectopically expressing miR-200b. Clinically, miR-200b downregulation was coupled with ZEB1 upregulation in approximately two-thirds of HCC patients. ZEB1 expression was positively correlated with CD13 and CD24 expressions, while EpCAM expression was positively correlated with miR-200b expression in HCCs.

Conclusions: The miR-200b-ZEB1 circuit is a master regulator of diverse stemness of HCC, which distincts HCCs into those containing CD13+/CD24+ CSCs from those containing EpCAM+ CSCs, and a thus potential target for anti-HCC therapy.

Citation Format: Sen-Yung Hsieh, Su-Chun Tsai. The miR-200b-ZEB1 circuit regulates diverse stemness of human hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2882. doi:10.1158/1538-7445.AM2017-2882
Abstract 2885: Activation of IL1α signaling by HER2 overexpression promotes breast cancer stem cells
Authors: Liu Shou , Lee Ji shin , Chen Hexin
Published: July 2017

Breast cancer is a heterogeneous disease and only a small proportion of cells known as cancer stem cells (CSCs) have ability to generate tumor. Recently, it has been reported that HER2 overexpression increase breast cancer stem cells (BCSCs). However, the underlying mechanism is not clearly known. In this study, we explored the molecular mechanism how HER2 increase BCSCs. Our data has demonstrated HER2 induces BCSCs by indirectly activating NF-kB and STAT3 signaling. To figure out the direct target of HER2, we did the microarray and found that HER2 upregulates the expressions of IL1a and IL6, two major cytokines which directly activates NFkB and STAT3, respectively. Interestingly, we found that IL1a also indirectly activates STAT3. IL1α induced STAT3 was blocked when IL6 was knock out from cells. We found that HER2 enhances IL1α transcription by activating PU.1 which is known transcription factor of IL1a. Finally, we studied effect of IL1a on tumorigenesis, and found that IL1α KO dramatically attenuates the tumor growth in NOD/SCID mice. Taken together, we found that HER2 induces BCSCs by upregulating IL1a and IL6 expression. We for first time demonstrating that IL1α plays a critical role in HER2-induced expansion of BCSC population and may be a potential therapeutic target for HER2 positive breast cancer.

Citation Format: Shou Liu, Ji shin Lee, Hexin Chen. Activation of IL1α signaling by HER2 overexpression promotes breast cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2885. doi:10.1158/1538-7445.AM2017-2885
Abstract 2895: Octamer-4/microRNA-1246 signaling axis drives Wnt/β-catenin activation in liver cancer stem cells
Authors: Chai Stella , Ng Kai-Yu , Tong Man , Lau Eunice Y. , Lee Terence K. , Chan Kwok Wah , Yuan Yun Fei , Cheung Tan To , Cheung Siu Tim , Wang Xiao Qi , Wong Nathalie , Lo Chung Mau , Man Kwan , Guan Xin Yuan , Ma Stephanie K.
Published: July 2017

Hepatocellular carcinoma (HCC), the main type of liver cancer in human, is one of the most prevalent and deadly malignancies in the world. Despite advances in therapy, prognosis remains dismal, largely attributed by our limited understanding on information related to the progressive development of the disease, particularly in their cancer-initiating and stem cell-like properties. Wnt/β-catenin signaling is activated in CD133 liver cancer stem cells (CSC), a subset of cells known to be a root of tumor recurrence and therapy resistance in HCC. However, the regulatory mechanism of this pathway in CSCs remains unclear. Here, we show that human miRNA, miR-1246, promotes cancer stemness including self-renewal, drug resistance, tumorigencity and metastasis by activation of Wnt/β-catenin pathway via suppressing the expression of AXIN2 and GSK3β, two key members of the β-catenin destruction complex. This observation was validated by both in vitro and in vivo functional / cell biological studies on HCC cell lines with or without miR-1246 expression modulated by lentiviral based knockdown and overexpression strategies as well as in miR-1246 repressed HCC cells with concomitant expression of wild-type or constitutively active β-catenin. Clinically, high endogenous and circulating miR-1246 was identified in HCC clinical samples and correlated with a worse prognosis. Further functional analysis identified Oct4 to be the direct upstream regulator of miR-1246, which cooperatively drive β-catenin activation in liver CSCs. In conclusion, our findings not only uncover the non-canonical regulation of Wnt/β-catenin in liver CSCs by Oct4/miR-1246 signaling axis, but also provide a novel diagnostic marker as well as therapeutic intervention for HCC.

Citation Format: Stella Chai, Kai-Yu Ng, Man Tong, Eunice Y. Lau, Terence K. Lee, Kwok Wah Chan, Yun Fei Yuan, Tan To Cheung, Siu Tim Cheung, Xiao Qi Wang, Nathalie Wong, Chung Mau Lo, Kwan Man, Xin Yuan Guan, Stephanie K. Ma. Octamer-4/microRNA-1246 signaling axis drives Wnt/β-catenin activation in liver cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2895. doi:10.1158/1538-7445.AM2017-2895
Abstract 2897: Oncogenic Kras activation in gastric adenocarcinoma promotes cancer stem cell phenotypes including metastasis & chemotherapy resistance
Authors: Yoon Changhwan , Chang Kevin K. , Till Jacob , Ryeom Sandra W. , Yoon Sam S.
Published: July 2017

INTRODUCTION:

The Cancer Genome Atlas found that the receptor tyrosine kinase (RTK)-Ras signaling pathway is altered in half of gastric adenocarcinomas (GAs). We added oncogenic Kras to the Atp4b-Cre;Cdh1fl/fl;Trp53fl/fl mouse model of GA and found accelerated tumorigenesis and metastasis. We also found Kras activity to be higher in gastric cancer stem-like cells (CSCs). Thus we hypothesized that Kras activty is critical for maintenance of gastric CSCs and promotes CSC phenotypes.

METHODS:

Human and murine GA cell lines were examined. The effect of Kras pathway inhibition was examined in GA spheroid cells and monolayer cells in various in vitro assays. Kras activity and Kras pathway inhibition was examined in CSCs, primary tumors and metastases in our GA mouse model. The combination of chemotherapy and Kras pathway inhibition was tested in human GA xenografts.

RESULTS:

Kras inhibition with shRNA or MEK inhibitor PD0325901 decreased the ability of GA cells to form spheroids and deceased expression of the stem cell transcription factor, Sox2. CD44(+) gastric CSCs had 65.8-75.4% higher migration, 64.2-79.5% higher invasion, and 63.1-70.2% more anchorage-independent growth compared to unselected cells. These properties could all blocked by 71.1-82.7% with Kras shRNA or PD0325901. In our GA mouse model, PD0325901 starting at 6 weeks of life increased median survival from 76 days to 95 days. Primary tumors and metastases from these mice with and without treatment with MEK inhibition are being analyzed for level of CD44 CSCs, Kras activity, and extent of metastases. Gastric CSCs were resistant to 5-fluorouracil and cisplatin chemotherapy, and this chemotherapy resistance could be reversed in human GA xenografts transducing cells with Kras shRNA.

CONCLUSION:

Kras is more active in gastric CSCs than non-CSCs and promotes malignant phenotypes including metastasis and chemotherapy resistance. Kras pathway inhibition can block these CSC phenotypes, and thus may prove useful in various combination therapies.

Note: This abstract was not presented at the meeting.

Citation Format: Changhwan Yoon, Kevin K. Chang, Jacob Till, Sandra W. Ryeom, Sam S. Yoon. Oncogenic Kras activation in gastric adenocarcinoma promotes cancer stem cell phenotypes including metastasis & chemotherapy resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2897. doi:10.1158/1538-7445.AM2017-2897
Abstract 2902: Epithelial-type CD133+ stem-like lung cancer cells emerge higher drug resistance through MDFIC-mediated Wnt/β-catenin signaling pathway
Authors: Chen Chao-Ju , Yang Chih-Jen , Huang Ming-Shyang , Liu Yu-Peng
Published: July 2017

Background: The epithelial-to-mesenchymal transition (EMT) has been described to promote drug resistance and cancer stem cell (CSC) properties. Many studies demonstrated that a major proportion of circulating tumor cell (CTC) exhibits EMT and CSC characteristics. A recent finding revealed the presence of epithelial type (EpCAM+) CTC was associated with poor outcome, whereas the mesenchymal type (EpCAM-) CTC were not. We therefore hypothesize that the epithelial-type CSC may exhibit higher drug resistant ability.

Methods: We isolated epithelial type (E+) and mesenchymal type (E-) CD133+ cells and CD133- cells from PC14 lung cancer cell line by fluorescence assisted cell sorting. We used western blot, QPCR, immunofluorescence, sphere formation assay and tumor xenograft assay to characterize the 4 subpopulations. The drug resistant ability was determined by cell viability assay and in vivo drug response assays. The drug resistant signature was identified by comparing the gene expression profile from four subpopulations and Gene Expression Omnibus (GEO) database. Knockdown and overexpression of MDFIC in PC14 subpopulations were established by using lentivirus vectors. Immunoprecipitation and subcellular fractionation were performed for drug resistant mechanism investigation.

Results: The epithelial type PC14 CD133+ cells (E+/CD133+ subpopulation) exhibited higher sphere formation ability and was more resistant to the treatment of chemotherapy agents compared to the mesenchymal type CD133+ cells (E-CD133+ subpopulation) in vitro and in vivo. Gene expression profiling showed 86 genes were bioinformatically predicted as drug resistant signature and were correlated with the disease free survival of the patients with lung cancer. Among these genes, the mRNA level of 20 genes were significantly related to the patient’s prognosis in the GSE31210 dataset. Human I-mfa domain-containing protein (MDFIC) was highly expressed in E+/CD133+ subpopulation. Knockdown and overexpression of MDFIC modulates drug resistance ability in cancer cells. MDFIC increased the level of free β-catenin through binding and stabilizing the axin-GSK3-β-β-catenin destruction complex and increased the transcriptional activity of Wnt/β-catenin signaling.

Conclusion: The epithelial-type CD133+ stem-like lung cancer cells are more resistant to the chemotherapy through MDFIC-mediated Wnt/β-catenin signaling activation.

Citation Format: Chao-Ju Chen, Chih-Jen Yang, Ming-Shyang Huang, Yu-Peng Liu. Epithelial-type CD133+ stem-like lung cancer cells emerge higher drug resistance through MDFIC-mediated Wnt/β-catenin signaling pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2902. doi:10.1158/1538-7445.AM2017-2902
Abstract 2919: Quantitative mapping of epidermal growth factor receptor activation in single breast cancer cells treated with targeted therapies
Authors: Le Phuong , Kilian Kristopher , Smith Andrew
Published: July 2017

Twenty percent of breast cancers are triple-negative, lacking estrogen receptor, progesterone receptor, and HER2. There is currently no specific FDA-approved targeted therapy for triple-negative breast cancer patients. Approximately half of triple-negative breast cancers overexpress epidermal growth factor receptor (EGFR), however phase II trials have only shown a 5% response rate with targeted inhibition. A quantitative analysis of EGFR signaling pathway dynamics of single cells at the single molecule level has the potential to shed light on the mechanism of lack of response to targeted therapy, as well as the cell-to-cell heterogeneity of response. Here, we combine single-molecule 3D imaging of EGFR using fluorescent quantum dots (QDs) with cell geometry normalization by micro-patterning to quantitatively map EGFR endocytosis in single cancer cells. Triple negative MDA-MB-231 cells conformed to defined geometries (rectangular with different aspect ratios) were grown on soft polyacrylamide gels after micro-contact printing islands of fibronectin. Two color QD conjugates of EGFR and its ligand, EGF, are used to track ligand binding and receptor internalization upon activation in the absence and presence of different families and dosages of pharmaceutical EGFR inhibitors. We demonstrated that microcontact-printing normalizes cell geometry while maintaining EGFR localization so that EGFR signaling response can be quantitatively assessed on a single-cell basis and that QD conjugates can specifically label EGFR and EGF. Quantitative single-molecule imaging at single-cell level revealed high level of heterogeneity in the amount and spatial localization of EGF binding and EGFR endocytosis among the cell population in the presence and absence of EGFR inhibitor, gefitinib. Using this platform, we will investigate if spatial organization of EGFR clusters within individual cells contribute to single-cell heterogeneous response to EGFR inhibitors. We anticipate quantitative mapping of EGFR activity with drug treatment will help to elucidate why EGFR drug treatments fail and provide a means to develop combination therapy to address heterogeneity in triple negative-breast cancer.

Citation Format: Phuong Le, Kristopher Kilian, Andrew Smith. Quantitative mapping of epidermal growth factor receptor activation in single breast cancer cells treated with targeted therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2919. doi:10.1158/1538-7445.AM2017-2919
Abstract 292: Synthesis and characterization of the novel benzylindazole-based BUB1 kinase inhibitor BAY 1816032 with potent anti-tumor activity
Authors: Hitchcock Marion , Mengel Anne , Nising Carl
Published: July 2017

BUB1 (budding uninhibited by benzimidazoles 1) is a serine/threonine protein kinase. The protein is bound to kinetochores and plays a key role in the establishment of the mitotic spindle checkpoint and chromosome congression prior to anaphase.

Inhibition of BUB1 kinase represents a novel approach for cancer treatment: whereas cell cycle arrest is the predominant mode of action of a number of antimitotic cancer drugs (e.g. taxanes and vinca alkaloids), BUB1 inhibition results in aneuploidy and cell death by driving cells through mitosis irrespective of misattached chromosomes.

Here, we disclose for the first time the structure and functional characterization of a novel, first-in-class Bub1 kinase inhibitor. Medicinal chemistry efforts resulted in BAY 1816032 featuring high potency, long target residence time and good oral bioavailability. BAY 1816032 is highly selective for BUB1 displaying single digit nanomolar biochemical potency and double-digit nanomolar cellular potency (H2A induced HeLa-cells). Synergistic effects can be observed when BUB1 inhibitor BAY 1816032 is combined with low doses of paclitaxel affecting chromosome segregation and cell proliferation. X-ray data of benzylindoles allowed a better understanding of the binding mode. Further data on structure-activity relationships including pharmacokinetic characterization, drug metabolism and the synthesis of BAY 1816032 and analogues will be presented.

These results validate the innovative concept of interference with mitotic checkpoints and justify clinical proof of concept studies evaluating BUB1 inhibitor BAY 1816032 in combination with taxanes in order to enhance their efficacy and to potentially overcome resistance.

Citation Format: Marion Hitchcock, Anne Mengel, Carl Nising. Synthesis and characterization of the novel benzylindazole-based BUB1 kinase inhibitor BAY 1816032 with potent anti-tumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 292. doi:10.1158/1538-7445.AM2017-292
Abstract 2925: Distribution of copy number alterations defines clonal populations involved in colorectal cancer evolution
Authors: Quintanilla Isabel , Asensio Elena , Pellisé Maria , Castells Antoni , Cuatrecasas Miriam , Camps Jordi
Published: July 2017

Colorectal cancer progresses in a multi-step manner with adenoma being the most well-known precursor lesion. Malignant polyp, an adenoma that contains a focus of adenocarcinoma, is a suitable model to study the colorectal tumor evolution. Although the mutations that lead adenoma to evolve into carcinoma have been previously described, the copy number changes involved in this malignant transformation have not been fully explored. To understand how these genomic alterations contribute to carcinogenesis, we used sequential fluorescence in situ hybridization using probes for the oncogenes EGFR, MYC, CDX2, and ZNF217 and the tumor suppressor genes SMAD7 and APC in order to analyze the copy number changes in 23 cases of malignant polyps and 10 cases of low grade dysplasia (LGD) adenomas based on single cell analyses. We found the levels of genomic heterogeneity increased from LGD adenomas to malignant polyps, with the adenoma component having a lower degree of chromosomal instability than the adenocarcinoma component. Despite the intercellular heterogeneity, we observed different patterns of evolution. The gain of ZNF217 was the earliest event as it was found to be in some cases of the LGD adenoma, and was also important in the neoplastic transformation of malignant polyps. Other notable genomic imbalances we observed during the malignant transformation were the gain of CDX2 and the loss of SMAD7. Interestingly, in a significant proportion of cases we observed the gain of all loci analyzed to be the decisive step in the transition from adenoma to carcinoma, suggesting a whole genome duplication event. Lastly, in half of the malignant polyps studied the main clone in the carcinoma component was already present in the adjacent adenoma component, although in some cases at a low frequency only detected by single cell analysis. Our data suggest that copy number changes are early events in colorectal carcinogenesis that can determine the evolution from adenoma to carcinoma.

Citation Format: Isabel Quintanilla, Elena Asensio, Maria Pellisé, Antoni Castells, Miriam Cuatrecasas, Jordi Camps. Distribution of copy number alterations defines clonal populations involved in colorectal cancer evolution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2925. doi:10.1158/1538-7445.AM2017-2925