bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 424: Genomic instability changes of circulating tumor DNA reflect the responses to chemotherapy or targeted therapy in advanced gastric cancer
Authors: Chen Zuhua , Zhang Cheng , Li Beifang , Niu Yunyun , Chen Limeng , Zhang Mengqi , Yang Jing , Lu Sijia , Gao Jing , Shen Lin
Published: August 2019

Background: Gastric cancer was characterized by frequent somatic copy number alterations and high genomic instability, yet the significance of genomic instability and its changes implicated by drug treatment in advanced gastric cancer (AGC) remain unclear. In this study, we investigated genomic instability changes of circulating tumor DNA (ctDNA).

Methods: A total of 101 plasmas and paired blood cells from 26 patients with AGC before (N=26) and after (N=75) treatment were prospectively collected. Plasma ctDNA was separated and assessed for copy number variations (CNV) by whole genome sequencing (WGS), and we assessed the correlation between genomic indexes and therapeutic response.

Results: Genomic instability with diverse patterns was observed in 20 of 26 patients (77%) prior to drug treatment. For patients with high (N=20) level genomic instability prior to drug treatment, the response rate (55%, 11/20) was significantly higher than that (17%, 1/6) in patients with low level (N=6) genomic instability (P=0.17). Notably, genomic instability changed with the administration of drugs, which reflected its correlation with therapeutic response. All ctDNAs (94%, 14/15) collected at the time of partial response (PR) after treatment displayed low-genomic instability. However, 52% ctDNAs (13/25) collected at the time of progressive disease (PD) after treatment showed high-level genomic instability. Furthermore, several patterns of CNV were categorized in ctDNAs. CNV pattern after acquiring drug resistance were largely unchanged with respect to CNV baseline patterns.

Conclusions: Genomic instability based on ctDNA can be used to predict and monitor therapeutic response in gastric cancer, although validation in larger cohort would be necessary.

Citation Format: Zuhua Chen, Cheng Zhang, Beifang Li, Yunyun Niu, Limeng Chen, Mengqi Zhang, Jing Yang, Sijia Lu, Jing Gao, Lin Shen. Genomic instability changes of circulating tumor DNA reflect the responses to chemotherapy or targeted therapy in advanced gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 424.
Abstract 4261: Upregulation of miR-34b, miR-892a and inhibition of p-glycoprotein play an important role for melatonin-induced apoptosis and autophagy in vincristine-resistant human oral cancer cells
Authors: Yang Shun-Fa , Hsieh Ming-Ju , Lin Chiao-Wen
Published: August 2019

Multidrug-resistance was resistance of cells to a variety of drugs normally used in tumor treatment. The related mechanism of drug resistance in oral cancer has not been completely explained. Melatonin is an endogenously-produced molecule involved in active biological mechanisms including antiproliferation, oncogene expression modulation, antitumor invasion and migration, and anti-inflammatory, antioxidant, and antiangiogenic effects. Despite these numerous actions, the effect of melatonin on vincristine (VCR)-resistant human oral cancer cells still largely unknown. Present study analyzed the role of melatonin on VCR-resistant human oral cancer cells along with the underlying mechanism. We determined that melatonin induces apoptosis and autophagy of VCR-resistant oral cancer cell; these actions are mediated by AKT, p38, and JNK. Melatonin inhibits ABCB1 and ABCB4 expression in vitro/vivo. Melatonin decrease drug resistance and promotes VCR-resistant oral cancer cell execute apoptosis through upregulation of miR-892a and miR-34b-5p expression. The expression of miR-892a and miR-34b-5p are related with melatonin-induced apoptosis, but not autophagy. Thus, melatonin is a potential novel agent in chemotherapy for VCR-resistant human oral cancer cell lines.

Citation Format: Shun-Fa Yang, Ming-Ju Hsieh, Chiao-Wen Lin. Upregulation of miR-34b, miR-892a and inhibition of p-glycoprotein play an important role for melatonin-induced apoptosis and autophagy in vincristine-resistant human oral cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4261.
Abstract 4263: Autophagic ovarian cancer cells exhibit substantially enhanced sensitivity to ALK inhibition
Authors: Blessing Alicia M. , Mao Weiqun , Pang Lan , Rask Philip , Lu Zhen , Bast Robert C.
Published: August 2019

One of the major factors contributing to poor outcomes for patients with ovarian cancer is the persistence of dormant, drug resistant cancer cells after primary surgery and chemotherapy. The persistent cancer found in positive second look operations is poorly vascularized and autophagy is widespread in more than 80% of cases. Consequently, drugs that regulate survival in autophagic cancer cells may be much more active when administered as maintenance therapy than when used to treat gross recurrent disease. Using unbiased siRNA screens, we have identified target genes that regulate the survival of ovarian cancer cells that are undergoing autophagy-induced by the re-expression of DIRAS3 (ARHI) or by serum starvation. Knockdown of the anaplastic lymphoma kinase (ALK) significantly reduced survival of ovarian cancer cells that were undergoing autophagy. Importantly, FDA-approved ALK inhibitors, including crizotinib, exhibited significantly greater toxicity after induction of autophagy by upregulation of DIRAS3 or serum starvation in 5 ovarian cancer cell lines. Induction of autophagy by upregulation of DIRAS3 or serum starvation in ovarian cancer cells reduced the IC50 of crizotinib and other ALK inhibitors ranging from 1.5 to 20-fold (all p-values <0.05). Crizotinib treatment in autophagic cancer cells enhanced autophagy and apoptosis via a decrease in p-STAT3 and BCL-2 signaling. Selective targeting of p-STAT3 or BCL-2 also resulted in significantly greater toxicity after induction of autophagy by upregulation of DIRAS3 or serum starvation in multiple ovarian cancer cells. Inducible upregulation of DIRAS3 by doxycycline in the first 6 weeks prompted autophagy and dormancy in two separate xenograft models (SKOV3 and OVCAR8). Crizotinib treatment of dormant autophagic SKOV3 xenografts prolonged median survival by 9.7 weeks (p<0.0032) and cured a subset of mice. Thirteen of fifteen mice (87%) bearing SKOV3 xenografts and nine of eleven mice (82%) bearing OVCAR8 xenografts, were tumor free at 200 days compared to the other three control arms (overall survival, p<0.0001 and p<0.05, respectively). Our studies suggest that ALK inhibitors might provide an effective agent to eliminate autophagic, dormant, drug resistant ovarian cancer cells that remain after conventional cytoreductive surgery and combination chemotherapy.

Citation Format: Alicia M. Blessing, Weiqun Mao, Lan Pang, Philip Rask, Zhen Lu, Robert C. Bast. Autophagic ovarian cancer cells exhibit substantially enhanced sensitivity to ALK inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4263.
Abstract 427: Detection and molecular characterization of circulating tumor cells in advanced head and neck squamous cell carcinoma
Authors: Tada Hiroe , Takahashi Hideyuki , Ishii Hiroki , Kuwabara-Yokobori Yuki , Shino Masato , Chikamatsu Kazuaki
Published: August 2019

Malignant properties of tumor cells are genetically and epigenetically altered during tumor development and progression. Moreover, tumor cells rapidly change to treatment resistant phenotype by various therapeutic pressures, and not only become more heterogeneous but also possess metastatic potential. Detection and characterization of circulating tumor cells (CTCs) in the bloodstream of cancer patients have been currently remarked as a valuable tool for real-time evaluation of tumor tissue with phenotypic heterogeneity in the diagnosis and treatment of various cancers, however these have been still challenging. In the present study, we investigated the presence of CTCs and their molecular characterization by the combination of microfiltration system and RT-qPCR method. Peripheral blood samples were collected from 30 patients with advanced head and neck squamous cell carcinoma (HNSCC) and passed through two CellSieveTM microfilters using a low-pressure filtration system. The existence of CTCs collected from the first filter was determined by the expression of epithelial-related genes (KRT19, EPCAM, EGFR, or MET), then the expression of cell proliferation (PIK3CA and CCND1)-, EMT (SNAI1 and VIM)-, cancer stemness (CD44, NANOG, and ALDH1A1)-, and immune regulation (CD47, CD274, and PDCD1LG2)-related genes was analyzed for molecular characterization of CTCs. The gene expression in cells collected from the second filter was used for normalization of target genes. Sixteen (53.3%) of 30 patients were positive for at least one epithelial-related gene. Interestingly, the number of patients with locoregional recurrence or distant metastasis in 16 CTC-positive patients was 7 (43.8%) or 5 (31.3%); whereas that in 14 CTC-negative patients was 2 (14.3%) or 1 (7.1%), respectively. The gene expression profile in CTCs collected from 16 CTC-positive patients has revealed remarkable heterogeneity between HNSCC patients. Of 16 CTC-positive patients, PIK3CA was overexpressed in 56.3%, CCND1 in 43.8%, SNAI1 in 62.5%, VIM in 43.8%, CD44, in 50.0%, NANOG in 31.3%, ALDH1A1 in 56.3%, CD47 in 62.5%, CD274 in 37.5%, and PDCD1LG2 in 31.3%. Our results suggest that CTCs may play an important role in locoregional recurrence as well as distant metastasis in HNSCC. Further molecular profiling at the single-cell level of CTCs is needed to clarify the clinical significance of molecular phenotype of CTCs.

Citation Format: Hiroe Tada, Hideyuki Takahashi, Hiroki Ishii, Yuki Kuwabara-Yokobori, Masato Shino, Kazuaki Chikamatsu. Detection and molecular characterization of circulating tumor cells in advanced head and neck squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 427.
Abstract 4274: RNA methylation regulates osteosarcoma growth and progression via autophagy
Authors: Subbarayalu Panneerdoss , Yadav Pooja , Rao Manjeet
Published: August 2019

Osteosarcoma (OS) is the most common primary bone tumor and third most common cancer in children/teens, after lymphomas and brain tumors. OS is treated by surgery and multi-modal chemotherapy. Even though this treatment regimen has improved the 5-year survival rate to 60-70%, once osteosarcoma metastasize to lung and other bones, the survival is significantly reduced. Moreover, the quality of life for patients who do survive is often substantially reduced due to the toxicity associated with the chemotherapy. Since several decades, there hasn’t been any improvement in the osteosarcoma treatment outcome. Therefore, it is important to understand the molecular mechanism of osteosarcoma growth and metastasis and an urgent need to develop effective drug, which can be safe and effective for treating OS patients. We discovered that RNA methylation may regulate OS growth and progression by affecting autophagy. Our studies revealed that RNA demethylase AlkB homolog 5 (ALKBH5) supports OS viability, migration and invasion as well as tumor growth. We discovered several autophagy related genes were significantly altered in ALKBH5-silenced OS cells compared to scrambled control. Importantly, levels of LC3, which is a universal marker for monitoring autophagy, was significantly increased in ALKBH5 depleted OS cells. Furthermore, we found that autophagy initiation complex protein ULK1 level was drastically increased in ALKBH5-silenced cells when compared to scrambled control. To further establish the role of autophagy in osteosarcomogenesis, we treated OS cells with chloroquine, which is a well-known autophagy inhibitor and is currently being investigated for treating adult cancers in clinical trials. Interestingly, silencing of ALKBH5 significantly improved the efficacy of chloroquine as revealed by drastically reduced viability and invasive ability of OS cells. In conclusion, our study is first to shows that RNA methylation plays a critical role osteosarcoma growth and progression by regulating autophagy.

Citation Format: Panneerdoss Subbarayalu, Pooja Yadav, Manjeet Rao. RNA methylation regulates osteosarcoma growth and progression via autophagy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4274.
Abstract 4279: Heterogeneous LC3A expression regulates lung cancer cell plasticity
Authors: Miao Chia-Cheng , Hwang Wen , Chou Yu-Ting
Published: August 2019

Tumor metastasis is considered as the main cause that contributes to high mortality during lung cancer progression. Autophagy is a self-cleaning process to maintain cell integrity of intracellular organelles and proteins. To date, the role of autophagy in lung tumor metastasis remains elusive. Here, we report that lung tumors display a heterogeneous expression pattern of the autophagy mediator LC3A, the high expression of which is associated with low metastasis risk. We found a group of lung cancer cells contain differential LC3A expression levels and exhibit plasticity characterized by distinct proliferative and invasive properties. Immunofluorescence staining and immunoblotting assays revealed that LC3A-mediated autophagy is more active in highly proliferative but minimally invasive lung cancer cells than their lowly proliferative but highly invasive counterpart. Clonogenic analysis and cell cycle assays showed that LC3A silencing attenuated cellular growth, causing G1/S cell cycle arrest in highly proliferative lung cancer cells. Highly proliferative lung cancer cells exhibited a higher oxygen consumption rate, accompanied with an elevated oxygen species (ROS) level, compared to their lowly proliferative counterpart. Pharmacological inhibition of autophagy with chloroquine promoted the ROS production in highly proliferative lung cancer cells but not in the highly invasive counterpart. SOX2 expression enhanced LC3A expression and promoted proliferation but inhibited invasiveness in lung cancer cells. Knockdown of LC3A expression in SOX2-high proliferative cells enriched SOX2-low cells, exhibiting decreased proliferation but increased invasiveness. Combined, our findings provide substantial evidence to suggest that LC3A cooperates with SOX2 signaling to regulate lung cancer cell plasticity.

Citation Format: Chia-Cheng Miao, Wen Hwang, Yu-Ting Chou. Heterogeneous LC3A expression regulates lung cancer cell plasticity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4279.
Abstract 4281: LT-IIc, a bacterial type II heat-labile enterotoxin, induces specific lethality in triple negative breast cancer cells by modulaton of autophagy and induction of apoptosis and necroptosis
Authors: Masso-Welch Patricia A. , Berlingeri Sofia Girald , King-Lyons Natalie D. , Mandell Lorrie , Hu John C. , Greene Christopher , Federowicz Matthew , Cao Peter , Heakal Yasser
Published: August 2019

Despite the recent advances in breast cancer treatment, triple negative breast cancer (TNBC) remains a serious health problem with limited treatment options. Poor prognosis is due to the development of chemoresistance. To discover novel therapeutic approaches to treat TNBC, we screened cholera toxin (CT) and the members of the bacterial type II heat-labile enterotoxin family (LT-IIa, LT-IIb, and LT-IIc) for their capacity to induce cell death in TNBC cells. LT-IIc, but not the other toxins, significantly reduced viability of the TNBC cell lines BT549 and MDA-MB-231 (IC50 = 82.32 nM). LT-IIc had no significant cytotoxic effects on MCF10A (IC50 = 2600 nM), a non-tumorigenic breast epithelial cell line, and minimal effects on MCF7 and T47D, ER+ breast cancer cells, or SKBR-3, HER2+ cells. LT-IIc stimulated autophagy through inhibition of the mTOR pathway, while simultaneously inhibiting autophagic progression, as observed by the accumulation of LC3B-II and p62 proteins. Morphologically, LT-IIc induced accumulation of enlarged LAMP2+ autolysosomes selectively in TNBC cells. Bafilomycin A1, an inhibitor of autophagic flux, blocked the formation and/or retention of these autolysosomes. The increase in caspase 3, 7 activity and annexin V staining indicated that LT-IIc induced an apoptotic response. Co-treatment with necrostatin-1, however, demonstrated that the lethal response to LT-IIc is elicited, at least in part, by concomitant induction of necroptosis. Collectively, these experiments demonstrate that LT-IIc acts bifunctionally, inducing autophagy while simultaneously blocking autolysosomal progression in TNBC cells, resulting in specific cytotoxicity in this breast cancer subtype.

Citation Format: Patricia A. Masso-Welch, Sofia Girald Berlingeri, Natalie D. King-Lyons, Lorrie Mandell, John C. Hu, Christopher Greene, Matthew Federowicz, Peter Cao, Yasser Heakal. LT-IIc, a bacterial type II heat-labile enterotoxin, induces specific lethality in triple negative breast cancer cells by modulaton of autophagy and induction of apoptosis and necroptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4281.
Abstract 4282: Crosstalk between apoptosis and autophagy induced by docetaxel-magnetic nanoparticles with different surface in prostate cancer cells
Authors: Watanabe Masatoshi , Takahashi Sanai , Usugi Eri , Ishii Kenichiro , Hirokawa Yoshifumi
Published: August 2019

Although docetaxel-based chemotherapy prolongs life and relieves symptoms in patients with castration resistant prostate cancer (CRPC), this needs to be improved because of limitations such as systemic toxicity, and progression of docetaxel-resistance. Nanotechnology including nanoparticles has served a new role in medical sciences, leading to theranostics. Fe3O4 magnetic nanoparticles (MgNPs) have potential applications in drug delivery, cancer diagnosis and hyperthermia. We have already reported that MgNPs would modify the effect of docetaxel (DTX) in prostate cancer cells by oxidative DNA damage in prostate cancer cell lines. Combined treatment of docetaxel and MgNPs has also shown to induce apoptosis and autophagic cell death in DU145 cells. In this study, we analyzed the combined effect of DTX-carboxyl-modified MgNPs (MgNPs-COOH) on DU145 cells in a view of crosstalk between apoptosis and autophagy. The combination treatment of DTX and MgNPs-COOH more effectively inhibited cancer cell growth and induced apoptosis and autophagic cell death although MgNPs-COOH did exert no ROS production. This combination preferred autophagic cell death than apoptosis. These results suggest that MgNPs-COOH may induce different responses compared with MgNPs, and result in favorable development of current chemotherapy for CRPC.

Citation Format: Masatoshi Watanabe, Sanai Takahashi, Eri Usugi, Kenichiro Ishii, Yoshifumi Hirokawa. Crosstalk between apoptosis and autophagy induced by docetaxel-magnetic nanoparticles with different surface in prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4282.
Abstract 4283: The tumor suppressive effects of HPP1 in colorectal cancer are mediated by its EGF-like domain
Authors: Elahi Abul , Ajidahun Abidemi , Hussain Mazher S. , Hendrick Leah , Getun Irina , Becker Andreas , Yang Yan , Glazer Evan S. , Shibata David
Published: August 2019

Introduction: We have previously demonstrated that HPP1 is an epigenetically-silenced tumor suppressor gene that exerts its effects via an erbB4-JAK-STAT signaling pathway. Although identified as a secreted multi-moiety transmembrane protein, the specific component responsible for its growth suppressive function has not been elucidated. Notably, HPP1 contains a single Epidermal Growth Factor (EGF)-like domain that differs from EGF by the substitution of arginine (R) for histidine (H) at the critical 299 position. We sought to investigate the isolated biologic effects of HPP1’s EGF-like domain.

Methods: Synthetic wild type (WT; H299) and mutant (MUT; R299) peptides were prepared at our crystallographic core facility. The change in amino acid did not alter the predicted 3D structure of the peptide. A total of 50ng/ml of each peptide per well (6-well plate) was used to treat the HPP1 non-expressing HCT116 colon cancer cell line. Cells were starved for 24 hours with a peptide exposure time of 7 minutes. We subsequently examined alterations in relevant erbB-, JAK- and STAT-family proteins as well as associated changes in cell growth in soft agar.

Results: Treatment of HCT116 with WT peptide resulted in increased phosphorylation of erbB4, JAK1, JAK2, STAT1 and STAT2 with a concomitant downregulation of STAT3 activation as compared to untreated controls. Mutant peptide delivery did not result in any alterations in erbB4-JAK-STAT signaling components. WT peptide treatment resulted in a dramatic reduction in colony formation in soft agar as compared to mutant peptide-treated (p=0.0002) and control cells (p=0.0019). Significant increase in colony formation was observed in the mutant vs. control cells (p=0.0047).

Conclusion: The isolated effects of HPP1’s EGF-like domain mimic the observed signaling and growth suppressive alterations observed with full-length HPP1. This EGF-like domain along with its histidine residue at position 299 appear critical for HPP1 downstream signaling and its tumor suppressive effects. Further elaboration of these findings may have therapeutic implications.

Citation Format: Abul Elahi, Abidemi Ajidahun, Mazher S. Hussain, Leah Hendrick, Irina Getun, Andreas Becker, Yan Yang, Evan S. Glazer, David Shibata. The tumor suppressive effects of HPP1 in colorectal cancer are mediated by its EGF-like domain [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4283.
Abstract 4287: Peroxiredoxin 2 has a crucial role in the survival of gastric cancer cells by regulating β-catenin and TNF signaling
Authors: Kim Hee Sung , Lee Tae Hyeong , Kang Dong Hoon , Lee Peter Chang-Whan , Kim Byung Sik
Published: August 2019

Gastric cancer (GC) is globally the fifth most common cancer and third leading cause of cancer death. Functional activation of β-catenin is necessary for early events in gastric carcinogenesis and GC with mutation of APC gene, similar to colorectal tumorigenesis, occur during the early stages of gastric adenoma development. Mammalian 2-Cys peroxiredoxin (Prx) enzymes are overexpressed in most cancer tissues, but the effect of Prx2 expression on GC survival remains unclear. Here, we demonstrate that Prx2 deletion markedly reduces the active β-catenin levels and the expression of β-catenin target genes in GC cells. Furthermore, the TNF α-induced activation of ERK1/2 was inhibited and reciprocally, JNK phosphorylation and cleaved caspase3 was increased in Prx2-knockdown GC cells. Prx2 deletion also can suppress the viability, invasion and colony formation of GC cells. The proof-of-concept experiment using conoidinA as a Prx2 inhibitor shows it can significantly ablates the growth of 5-FU-resistant SNU620. Thus, our findings reveal that Prx2 is a key regulator of β-catenin and TNF signaling pathway in GC, and also suggest a pharmacologic strategy to effectively overcome drug-resistant GC.

Note: This abstract was not presented at the meeting.

Citation Format: Hee Sung Kim, Tae Hyeong Lee, Dong Hoon Kang, Peter Chang-Whan Lee, Byung Sik Kim. Peroxiredoxin 2 has a crucial role in the survival of gastric cancer cells by regulating β-catenin and TNF signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4287.
Abstract 4290: Simultaneous inhibition of Atypical Protein Kinase-C and mTOR impedes bladder canSimultaneous inhibition of atypical protein kinase-C and mTOR impedes bladder cancer cell progression of bladder cancer cell progression
Authors: Islam S M Anisul , Patel Rekha S. , Bommareddy Raja Reddy , Smalley Tracess P. , Acevedo-Duncan Mildred
Published: August 2019

Despite enormous scientific advancements in cancer treatment, there is still so much to do to combat cancer particularly bladder cancer. Drugs once proved to be effective in treating bladder cancer showed reduced efficacy, hence, cancer recurrence rate is increasing. To overcome this situation, several attempts have been considered such as the development of a new effective drug or modify therapeutic regimens by combining two or more existing drugs. In recent years, atypical protein kinase C (aPKC), a phospholipid-dependent serine/threonine kinase, is considered as a central regulator of various cancer-causing signaling pathways and controls cell cycle progression, tumorigenesis, and metastatic determinant. In addition, the biologically important mammalian target of rapamycin (mTOR) pathway is altered in many cancers including bladder and can stimulate the activation of the aPKC pathway. In this study, we examined whether the concurrent inhibition of aPKC and mTOR using a combination of a novel aPKC inhibitor (ICA-I, an inhibitor of PKC-ι, or ζ-Stat, an inhibitor of PKC-ζ) and rapamycin blocks bladder cancer progression. The cell lines tested were MC-SV-HUCT2 normal bladder and TCCSUP bladder cancer cells. Our observed data showed that the combination therapy induced a significant reduction of human bladder cancer cells’ viability, also, individual treatment of aPKC inhibitor and rapamycin brought a similar effect. Moreover, the concurrent inhibition of aPKC and mTOR retards the metastasis of bladder cancer cells. These findings indicate that the administration of aPKC inhibitor together with rapamycin would be a useful therapeutic option in treating bladder cancer.

Citation Format: S M Anisul Islam, Rekha S. Patel, Raja Reddy Bommareddy, Tracess P. Smalley, Mildred Acevedo-Duncan. Simultaneous inhibition of Atypical Protein Kinase-C and mTOR impedes bladder canSimultaneous inhibition of atypical protein kinase-C and mTOR impedes bladder cancer cell progression of bladder cancer cell progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4290.
Abstract 4297: MYC HIF-2 alpha embryonic stemness genes mediate a transcriptional network to maintain asymmetric self-renewal in oral cancer
Authors: Pal Bidisha , Tasabehji Wael , Sorra Sandhya , Talukdar Joyeeta , Das Bikul
Published: August 2019

Cancer Stem Cells (CSCs) explains therapeutic failure across several tumor types. Despite being evolutionarily successful, the extreme ability to self-renew is asymmetric and limited to CSCs in heterogeneous tumor population. Thus, understanding molecular mechanisms maintaining CSCs asymmetric self-renewal would be therapeutically critical.Here, we identified putative molecular transcriptional network that may regulate CSCs asymmetric self-renewal. We developed 4-NQO (4-Nitroquinoline 1-oxide) induced mouse model of oral carcinogenesis that exhibited similar phenotype as human oral cancer. ABCG2+ CSCs enriched from 4-NQO derived mouse tumors and human oral cancer (n=7) patients indicated high expression of embryonic stemness genes such as Nanog, Sox-2, and Oct-4 in addition to MYC and HIF-2a. Higher engraftment potential was observed when ABCG2+ cells were injected to NOD/SCID mice, while HIF-2a silencing markedly increased mice survival during engraftments. ChIP assay revealed preferential binding of MYC to HIF-2a promoter regions in ABCG2+ vs ABCG2- cells. Nanog and Oct4 facilitated MYC binding to HIF-2a while gene silencing of Nanog and Sox2 led to loss of MYC and HIF-2a expression, indicating the possible regulation by MYC and HIF-2a. Further, we utilized clinical data from The Cancer Genome Atlas (TCGA) and demonstrated significant correlation between HIF-2a/MYC and embryonic stemness genes on Structural Equation Modeling Analysis (SEMA) platform, thereby confirming our in vitro/in vivofindings. Thus,our results may provide evidence of a biologically robust stemness transcriptional network regulating the asymmetric self-renewal of ABCG2+ CSCs.

Note: This abstract was not presented at the meeting.

Citation Format: Bidisha Pal, Wael Tasabehji, Sandhya Sorra, Joyeeta Talukdar, Bikul Das. MYC HIF-2 alpha embryonic stemness genes mediate a transcriptional network to maintain asymmetric self-renewal in oral cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4297.
Abstract 4300: Overexpression of PARP is an independent prognostic marker for poor survival in Middle Eastern breast cancer and its inhibition can be enhanced with embelin co-treatment
Authors: Ahmed Maqbool , Siraj Abdul K. , Pratheeshkumar Poyil , Parvathareddy Sandeep , Divya Sasidharan Padmaja , Al-Dayel Fouad , Tulbah Asma , Ajarim Dahish , Al-Kuraya Khawla S.
Published: August 2019

Patients with aggressive breast cancer (BC) subtypes usually don’t have favorable prognosis despite the improvement in treatment modalities. These cancers still remain a major cause of morbidity and mortality in females. This has fostered a major effort to discover actionable molecular targets to treat these patients. Poly ADP ribose polymerase (PARP) is one of these molecular targets that are under comprehensive investigation for treatment of such tumors. However, its role in the pathogenesis of BC from Middle Eastern ethnicity has not yet explored. Therefore, we examined the expression of PARP protein in a large cohort of over 1000 Middle Eastern BC cases by immunohistochemistry. Correlation with clinico-pathological parameters were performed. Nuclear PARP overexpression was observed in 44.7% of all BC cases and was significantly associated with aggressive clinico-pathological markers. Interestingly nuclear PARP overexpression was an independent predictor of poor prognosis. PARP overexpression was also directly associated with XIAP overexpression, with PARP and XIAP co-expression in 15.8% (159/1008) of our cases. We showed that combined inhibition of PARP by olaparib and XIAP by embelin significantly and synergistically inhibited cell growth and induced apoptosis in BC cell lines. Finally, co-treatment of olaparib and embelin regressed BC xenograft tumor growth in nude mice. Our results revealed the role of PARP in Middle Eastern BC pathogenesis and prognosis. Furthermore, our data support the potential clinical development of combined inhibition of PARP and XIAP, which eventually could extend the utility of olaparib beyond BRCA deficient cancer.

Citation Format: Maqbool Ahmed, Abdul K. Siraj, Poyil Pratheeshkumar, Sandeep Parvathareddy, Sasidharan Padmaja Divya, Fouad Al-Dayel, Asma Tulbah, Dahish Ajarim, Khawla S. Al-Kuraya. Overexpression of PARP is an independent prognostic marker for poor survival in Middle Eastern breast cancer and its inhibition can be enhanced with embelin co-treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4300.
Abstract 4301: Hypoxia-induced Nur77 activates PI3K-p110a/Akt/mTOR via suppression of Dicer/let-7i-5p to induce epithelial-to-mesenchymal transition in colon cancer cells
Authors: To Sally K. Y. , Deng Shan , Zeng Jin-Zhang , Wong Alice Sze Tsai
Published: August 2019

Cancer cells reside in the hypoxic niches of tumors easily undergo epithelial-to-mesenchymal transition (EMT). We have recently shown that hypoxia-induced EMT to enhance colon cancer cell invasive growth is dependent on the orphan nuclear receptor Nur77 and is mediated by Akt signaling. However, its underlying molecular mechanisms remain elusive. Here we found that hypoxia-induced Nur77 reduced Akt phosphorylation and its downstream mediator mTOR by decreasing the mRNA stability of p110α, the catalytic subunit α of phosphatidylinositol 3-kinase. Further analyses revealed that this effect could be mediated by down-regulation of Dicer, an important microRNA (miR) processor, and decreased biogenesis of the miR, let-7i-5p. Luciferase reporter assays confirmed that let-7i-5p could directly target the 3’UTR of p110α mRNA. Knockdown of Dicer or overexpression of let-7i-5p inhibited Nur77-induced EMT phenotypes. These data uncover a novel mechanistic link connecting Nur77, Akt, and invasive properties of colon cancer in the hypoxic microenvironment.

Citation Format: Sally K. Y. To, Shan Deng, Jin-Zhang Zeng, Alice Sze Tsai Wong. Hypoxia-induced Nur77 activates PI3K-p110a/Akt/mTOR via suppression of Dicer/let-7i-5p to induce epithelial-to-mesenchymal transition in colon cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4301.
Abstract 4305: AMPK-RUNX2-mTORC2 axis involved in EMT of MDA-MB-231 breast cancer cells
Authors: Reddy Aramati Bindu , Gayatri Meher B. , Chava Suresh
Published: August 2019

Metformin is one of the most widely used biguanides for the treatment of type 2 diabetes, whose role as a potent anti-cancer drug has emerged in recent times. Its function as an anti-tumor agent is attributed to its ability to inhibit mTORC1, which is a key player in regulating cell proliferation. However, the use of metformin as an anti-cancer drug is hampered by several limitations. Hence, in order to elucidate the detailed mechanistic properties of metformin in cell growth and metastasis, we investigated the effect of metformin on mTORC2 activity in MDA-MB-231 cells. We report a novel mechanism by which metformin can increase the activity of mTORC2 in a Runx2-dependent fashion, which requires AMPK mediated stabilization of RUNX2. Furthermore, we found that mTORC2 and RUNX2 have a feed forward relation whereby the knockdown of rictor, a key component in activating mTORC2, resulted in loss of RUNX2 through GSK3-β-mediated ubiquitination of RUNX2. Since both mTORC2 and RUNX2 have been found to be involved in activating the EMT, metformin treatment may contribute to this activation by stabilizing AMPK-RUNX2-mTORC2 axis. These results demonstrate that metformin-induced mechanisms can influence metastasis even if they inhibit cell growth, but the genetic heterogeneity of the malignancy may govern cell fate.

Citation Format: Aramati Bindu Reddy, Meher B. Gayatri, Suresh Chava. AMPK-RUNX2-mTORC2 axis involved in EMT of MDA-MB-231 breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4305.
Abstract 4306: JunD-induced cell proliferation requires MYC signaling in prostate cancer cells
Authors: (Elliott) Bethtrice Thompson , Millena Ana Cecilia , Matyunina Lilya , Zhang Mengnan , Zou Jin , Wang Guangdi , Zhang Qiang , Bowen Nathan , Eaton Vanessa , Webb Gabrielle , Thompson Shadyra , McDonald John , Khan Shafiq
Published: August 2019

JunD, a member of the AP-1 transcription factor family, is involved in a variety of biological processes including cell proliferation, inflammation, differentiation, apoptosis, and carcinogenesis. We previously showed that JunD is essential for cell proliferation and demonstrated that the knock-down (KD) of JunD in PCa cells resulted in cell cycle arrest in G1-phase concomitant with a decrease in the levels of Id1, c-MYC, and Ki67, but an increased in p21 protein levels. Furthermore, the over-expression of JunD significantly increased proliferation in these cells suggesting that JunD regulates the expression of genes which are required for cell cycle progression. In this present study, employing gene expression profiling, quantitative proteomics, and validation approaches, we demonstrated that JunD KD is associated with distinct gene and protein expression patterns. Comparison integrative analysis by Ingenuity Pathway Analysis (IPA) identified 1) cell cycle control/regulation as the top canonical pathway whose members exhibited a significant decrease in their expression following JunD KD including PRDX3, PEA15, KIF2C, and CDK2, and 2) JunD target genes are involved in cell proliferation, with MYC as the key downstream regulator. Conversely, JunD over-expression induced cell proliferation and the expression of the above JunD target genes including c-MYC. When treated with JQ1, a c-MYC inhibitor, these cells exhibited a significant reduction in cell proliferation and a decrease in JunD target genes. Our data suggest that JunD-mediated cell proliferation involves MYC signaling and inhibiting its target genes may be an effective approach to blocking prostate carcinogenesis

Citation Format: Bethtrice Thompson (Elliott), Ana Cecilia Millena, Lilya Matyunina, Mengnan Zhang, Jin Zou, Guangdi Wang, Qiang Zhang, Nathan Bowen, Vanessa Eaton, Gabrielle Webb, Shadyra Thompson, John McDonald, Shafiq Khan. JunD-induced cell proliferation requires MYC signaling in prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4306.
Abstract 4307: RAGE is the key receptor for LPA in lung and mammary cancer progression and metastasis
Authors: Jangde Nitish , Ray Rashmi , Rai Vivek
Published: August 2019

Lung and breast cancer signaling are very complex; receptor for advanced glycation end products (RAGE) is highly expressed in various cancers and is correlated with poorer outcome in lung and other cancers. It is an immunoglobulin like membrane receptor shows binding with various ligands sharing structural likeness such as amyloid beta, advanced glycation end products (AGEs), S100B proteins, amphoterin and HMGB1 and mediates numerous inflammatory and cellular events including diseases including various cancers. LPA a RAGE ligand is a biologically active phospholipid involved in cell proliferation, migration and survival via its different G protein couple receptors (GPCRs). LPA and its signalling pathways have been implicated in different pathological conditions of lung tissue, including inflammation, fibrosis and cancer activating various signalling pathways. Here, we have identified RAGE-LPA signaling mechanisms showing AKT, STAT3 and ERK as downstream signaling pathways gets activated upon LPA treatment via RAGE receptor in both lung and breast cancer cells. RAGE knockdown with multiple independent shRNAs in lung and breast cancer cells led to decreased transwell invasion and soft agar colony formation, and proliferation upon LPA stimulation. Our RAGE silencing study in lung and breast cancer cells upon LPA treatment showed upregulation of specific oncogenes Cyclin D1, c-Myc and VEGF via RAGE receptor. RAGE association with LPA induced epithelial to mesenchymal transition (EMT) in both lung and breast cancer cells have also been observed by the RAGE attenuation studies by examining the expression of some EMT markers. The physiological significance of LPA-RAGE axis was exposed by our xenograft study by nude mice intraperitoneal injections of control and RAGE inhibited lung and mammary tumors generated by LPA doses in alternative days, results the formation of tumor foci on peritoneum wall via RAGE receptor. This study provides novel therapeutic insights as the use of RAGE blocking antibodies and antagonists or competitive inhibitors of LPA against RAGE might be useful of breast cancer treatment. This study also suggests that RAGE and LPA can be used as biomarkers for the early detection of lung and breast cancers.

Citation Format: Nitish Jangde, Rashmi Ray, Vivek Rai. RAGE is the key receptor for LPA in lung and mammary cancer progression and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4307.
Abstract 4308: Phosphatidic acid binds to ERK3 and stimulates phosphorylation of the ERK3 activation loop
Authors: Myers Amanda , Aldharee Hitham , Bedi Shimpi , Long Weiwen
Published: August 2019

Protein kinases modulate the activity of other proteins through phosphorylation and themselves are often regulated by phosphorylation of their activation loop. Extracellular signal-Regulated Kinase 3 (ERK3) is an atypical member of the ERK family of Mitogen-Activated Protein Kinases (MAPK), with a SerGlu-Gly (SEG) motif in its activation loop rather than the canonical Thr-Xaa-Tyr (TXY) motif of ERK1/2. Activation loop phosphorylation of ERK3 is not regulated by the signals known to activate ERK1/2, such as mitogenic growth factors. The cellular stimuli activating ERK3 kinase are virtually unknown. Some kinases, including mTOR and p21 activated kinase 1 and 2 (PAK1/2), are stimulated by binding to certain phospho-lipid signaling molecules, such as phosphatidic acids. Here, we show ERK3 binds to specific phospholipids in vitro, and the C-terminal domain may be important for this interaction. In addition, ERK3 can localize to the cell membrane. Further, phosphatidic acid stimulated phosphorylation of the activation loop in ERK3. Together, these results suggest that ERK3 kinase activity might be upregulated by specific phosphatidic acid species in cells.

Citation Format: Amanda Myers, Hitham Aldharee, Shimpi Bedi, Weiwen Long. Phosphatidic acid binds to ERK3 and stimulates phosphorylation of the ERK3 activation loop [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4308.
Abstract 4310: Targeting Wnt signaling pathway using curcumin in metatstatic breast cancer cell lines
Authors: Ma Nancy , Havard Patty , Shenoy Vinayak , Shenoy Anitha K.
Published: August 2019

Metastasis is the major reason for breast cancer-related deaths. The current treatment options for breast cancer include surgery, endocrine targeted therapy, radiation, chemotherapy and/or immunotherapy. However, even after treatment of the primary tumor at an early stage, breast cancer patients are at an increased risk of developing sudden metastases. Wnt signaling is a pivotal oncogenic pathway that contributes to human breast malignancy. High levels of Wnt ligands have been frequently detected in human breast cancers and accumulating evidence indicate a key role for the Wnt signaling pathway in the metastatic process. Curcumin, an active ingredient of turmeric has been shown to alter Wnt signaling as well as suppress metastasis in a variety of cancers. Here, we hypothesize that curcumin inhibits metastatic potential of breast cancer cell lines by targeting the Wnt signaling pathway. An initial dose dependent cytotoxic assay was performed with curcumin on two distinct breast cancer cell lines (epithelial and mesenchymal) to determine the optimum concentration for subsequent experiments. Our results indicate that curcumin imparts a dose dependent cytotoxic effect on both epithelial as well as mesenchymal breast cancer cell lines. Further, we observed that curcumin treatment alters the Wnt signaling pathway genes. Additional studies are warranted to confirm the effect of curcumin on Wnt signaling pathway and its role in combating proliferation and migration of breast cancer cells.

Citation Format: Nancy Ma, Patty Havard, Vinayak Shenoy, Anitha K. Shenoy. Targeting Wnt signaling pathway using curcumin in metatstatic breast cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4310.
Abstract 4314: Reduced m6A modification predicts malignant phenotypes and augmented tumorigenic signaling in gastric cancer
Authors: Zhang Cheng , Zhang Mengqi , Ge Sai , Lin Xiaotin , Huang Wenwen , Gan Ying , Gao Jing , Shen Lin
Published: August 2019

Purposes: As the most abundant epigenetic modification on mRNAs and long non-coding RNAs, N6-methyladenosine (m6A) extensively exists in mammalian cells. Controlled by writers (methyltransferases), readers (signal transducers) and erasers (demethylases), m6A influences mRNA structure, maturation and stability, thus regulating protein expression in a post-transcriptional manner. Nevertheless, current understandings to m6A’s pathological roles in tumorigenesis, especially in gastric cancer (GC) remain to be unveiled. In this study, by incorporating multiple datasets and in vitro experiments, we assessed m6A’s clinical-pathological relevance to GC and explored the underlying mechanisms.

Methods: The protein and mRNA expressions of canonical m6A regulators (METTL3/METTL14 as writers, YTHDF1/YTHDF2/YTHDF3 as readers and ALKBH5/FTO as erasers) were merged as signatures to indicate levels of m6A modification. Changes of clinical variables, mutations and molecules were assessed in patients with different m6A indications. Pathway and phenotype changes predicted to be affected by m6A were assessed in vitro with gastric cancer HGC27 and MG803 cell lines.

Results: We discovered that writers and readers were potential tumor suppressive, while erasers were potential oncogenic factors in GC. Low-m6A modification was an indication for adverse clinical outcomes and was correlated with specific cancer driving mutations, including CDH1, AR and GLI3. Oncogenic signaling and phenotypes were selectively enriched in m6A groups. Through in vitro experiments, we proved that reduced m6A (represented by METTL14 knockdown) promoted GC proliferation and invasiveness potentially through activating Wnt and PI3K-Akt signaling, while restored m6A (represented by FTO knockdown) reversed these phenotypical and molecular changes.

Conclusions: Our work demonstrated that m6A is a potential prognostic predictor in gastric cancer and further reveals the reduction of m6A activates oncogenic signaling and promotes gastric cancer malignancy.

Citation Format: Cheng Zhang, Mengqi Zhang, Sai Ge, Xiaotin Lin, Wenwen Huang, Ying Gan, Jing Gao, Lin Shen. Reduced m6A modification predicts malignant phenotypes and augmented tumorigenic signaling in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4314.