bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4357: Long noncoding RNA HOTAIR is targeted and regulated by microRNA-141 in renal carcinoma cells
Authors: Chiyomaru Takeshi , Fukuhara1 Shinichiro , Saini Sharanjot , Majid Shahana , Deng Guoren , Shahryary Varahram , Chang Inik , Tanaka Yuichiro , Enokida Hideki , Nakagawa Masayuki , Dahiya Rajvir , Yamamura Soichiro
Published: May 2015

HOTAIR is a long non-coding RNA (lncRNA) which interacts with the Polycomb Repressive Complex and suppresses its target genes. HOTAIR has also been demonstrated to promote malignancy. MicroRNA-141 (miR-141) has been reported to play a role in the epithelial to mesenchymal transition (EMT) process and the expression of miR-141 is inversely correlated with tumorigenicity and invasiveness in several human cancers. We found that HOTAIR expression is inversely correlated to miR-141 expression in renal carcinoma cells. HOTAIR promotes malignancy including proliferation and invasion whereas miR-141 suppresses malignancy in renal carcinoma cells. miR-141 binds to HOTAIR in a sequence specific manner, and suppresses HOTAIR expression and functions including proliferation and invasion. Both HOTAIR and miR-141 were associated with the immunoprecipitated Argaunaute2 (Ago2) complex and the Ago2 complex cleaved HOTAIR in the presence of miR-141. These results demonstrate that HOTAIR is suppressed by miR-141 in an Ago2 dependent manner.

Citation Format: Takeshi Chiyomaru, Shinichiro Fukuhara1, Sharanjot Saini, Shahana Majid, Guoren Deng, Varahram Shahryary, Inik Chang, Yuichiro Tanaka, Hideki Enokida, Masayuki Nakagawa, Rajvir Dahiya, Soichiro Yamamura. Long noncoding RNA HOTAIR is targeted and regulated by microRNA-141 in renal carcinoma cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4357. doi:10.1158/1538-7445.AM2014-4357
Abstract 4362: miR-211 is contributive to the progression of oral carcinoma through targeting transcription factor 12 (Tcf12)
Authors: Chen Yi-Fen , Chang Kuo-Wei K. , Lin Shu-Chun
Published: May 2015

Oral squamous cell carcinoma (OSCC) is one of the prevalent malignancies worldwide. MicroRNAs are short RNA molecules that regulate pathogenesis, including OSCC carcinogenesis, by post-transcriptional down-regulation of target genes. Our previous study has identified a relationship between high miR-211 expression and the invasion of OSCC. This study further dissects the molecular mechanisms underlying the progression of OSCC as affected by miR-211. Tcf12 is a helix-loop-helix transcription factor with unclear implications in oral malignancies. MiR-211 was predicted to target the 3′UTR of transcription factor 12 (Tcf12). Reporter assays confirmed the direct targeting of miR-211 on Tcf12. MiR-211 expression decreased both endogenous and exogenous Tcf12 expression. Exogenous Tcf12 expression suppressed proliferation, migration and anchorage-independent colony formation of OECM-1 OSCC cells. On the contrary, knockdown of endogenous Tcf12 expression enhanced these oncogenic phenotypes. Furthermore, in tumor cells with miR-211 overexpression, Tcf12 can reduce its oncogenic potential; whereas miR-211 can also rescue the suppression of Tcf12 to tumor cells. Down-regulation of Tcf12 was identified in 75% (27/36) human OSCC samples. To elucidate the in vivo oncogenic roles of miR-211 in OSCC carcinogenesis, K14 promoter driven murine miR-211 transgenic mouse lines (K14-GFP- miR-211) were established. The Tcf12 expression in squamous epithelium was down-regulated in transgenic mice relative to wild type mice. After tumor induction by 4-nitroquinoline 1-oxide treatment, the transgenic mice exhibited more advanced tongue and esophageal tumorigenesis comparing to wild type mice. In summary, this study reveals that Tcf12 is suppressive to OSCC. MiR-211 regulates OSCC progression by targeting Tcf12. The K14-GFP-miR-211 transgenic mice will help future investigation of the pathogenic mechanisms underlying OSCC progression and the development of therapeutic strategy.

Citation Format: Yi-Fen Chen, Kuo-Wei K. Chang, Shu-Chun Lin. miR-211 is contributive to the progression of oral carcinoma through targeting transcription factor 12 (Tcf12). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4362. doi:10.1158/1538-7445.AM2014-4362
Abstract 4368: MicroRNAs miR-503 and -182 regulate FBXW7 contributing to the malignant transformation to colon adenocarcinoma
Authors: Li Lihua , Sarver Aaron , Khatri Rohini , Hajeri Praveensingh , Kamenev Iris , Thibodeau Stephen , Steer Clifford J. , Subramanian Subbaya
Published: May 2015

Progression from adenoma to colon cancer is a multi-step process and the role of microRNAs in this transformation is not completely understood.

We used both in vitro and in vivo approaches to demonstrate the role of miRNAs in the transformation of adenoma to adenocarcinoma. Reporter assays were used to show the direct interaction of miRNAs to target gene. A Tet-inducible TripZ system and miRzips constructs were used in the in vitro function and xenograft studies. Kaplan-Meier survival curves and Cox regression were used to analyze the survival data in colon cancer patients.

Here, we show that the combination of miR-503 and miR-182 contributes to the transformation of colon adenoma to adenocarcinoma by cooperatively regulating the tumor suppressor gene, FBXW7. We found that miR-182 was upregulated in both colon adenoma and adenocarcinoma, whereas miR-503 was upregulated only in adenocarcinoma, indicating a potential hierarchical and stepwise expression of these miRNAs in the regulation of FBXW7. Furthermore, we showed that colon adenoma derived non-tumorigenic AAC1 cells were transformative and tumorigenic in mice when expressing Tet-inducible miR-503. Finally, the combination of miR-503 and miR-182 transcript levels was predictive of poor outcome in colon cancer patients. We conclude that a step-wise expression of miR-182 and miR-503 in benign adenoma synergistically regulates the driver gene FBXW7, thus contributing to the progression of colon adenoma to adenocarcinoma.

Citation Format: Lihua Li, Aaron Sarver, Rohini Khatri, Praveensingh Hajeri, Iris Kamenev, Stephen Thibodeau, Clifford J. Steer, Subbaya Subramanian. MicroRNAs miR-503 and -182 regulate FBXW7 contributing to the malignant transformation to colon adenocarcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4368. doi:10.1158/1538-7445.AM2014-4368
Abstract 437: Novel function of the BAP1 nuclear deubiquitinase in the non-homologous end joining (NHEJ) pathway of double strand DNA repair
Authors: Ito Tatsuo , Kitano Shigehisa , Erdjument-Bromage Hediye , Ladanyi Marc
Published: May 2015

Background- The deubiquitinating enzyme BAP1 is mutated in a hereditary cancer syndrome with increased risk of malignant pleural mesothelioma (MPM) and uveal melanoma and in subsets of sporadic cases of these cancers, as well as in clear cell renal carcinoma and intrahepatic cholangiocarcinoma.

Methods and Results- We found that BAP1 knockdown is associated with increased DNA damage and that this effect of BAP1 knockdown is further enhanced by both X-irradiation and concomitant DNA-PKcs inhibitor II treatment in normal human mesenchymal stem cells and the MPM cell line H-Meso. A BAP1 mutant deficient in deubiquitinase activity is also associated with increased DNA damage in the H-Meso cells. Interactional total peptide (ITOP) analysis based on proteins identified by Liquid Chromatography coupled to tandem Mass Spectrometry (LC-MS/MS) of BAP1 protein complexes in H-Meso MPM cells and 293T cells identified known binding partners [HCF1, ASXL2, H2A] as well as possible novel interaction partners, notably PRKDC which encodes the catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs) and functions with the Ku70/Ku80 heterodimer in the non-homologous end joining (NHEJ) pathway of DNA repair. Double stranded DNA damage resulted in prominent nuclear expression of BAP1 protein in H-Meso cells and phosphorylation of BAP1 at Serine 395. Overexpression of dominant negative BAP1 C91W mutant in MPM cells caused instability of DNA-PKcs. Although strong polyubiquitination of DNA-PKcs was observed upon DNA damage in MPM cells expressing BAP1 C91W, this polyubiquitination was not observed in the presence of wild type BAP1. A plasmid-based NHEJ assay also confirmed a significant effect of BAP1 on NHEJ activity.

Conclusion- Functional complexes between BAP1 and the NHEJ family components point to a novel role in DNA repair and may shed light on BAP1's role as an important tumor suppressor

Citation Format: Tatsuo Ito, Shigehisa Kitano, Hediye Erdjument-Bromage, Marc Ladanyi. Novel function of the BAP1 nuclear deubiquitinase in the non-homologous end joining (NHEJ) pathway of double strand DNA repair. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 437. doi:10.1158/1538-7445.AM2014-437
Abstract 4373: Integrated microRNA and mRNA signature associated with the transition from the locally confined to the metastasized renal cell carcinoma
Authors: Billaud Jean-Noel
Published: May 2015

Background

MicroRNAs (miRNAs) are endogenous small non-coding RNAs that regulate gene expression by interfering translation or stability of target transcripts. One miRNA can interact with several hundred mRNAs, while one mRNA can be regulated by several miRNAs. This interplay between miRNA and their mRNA has been proposed as an important process in cancer development and progression. We have investigated molecular networks impacted by predicted mRNA targets of differentially expressed miRNAs in patients with clear cell renal cell carcinoma (ccRCC) diagnosed with or without metastasis.

Material and methods

miRNA and mRNA microarray expression profiles derived from primary clear cell renal cell carcinomas from patients with (in total 16 samples) or without diagnosed metastasis (in total 22 samples) were used to identify anti-correlated miRNA-mRNA interaction in ccRCC. For this purpose, Ingenuity pathway analysis microRNA Target Filter, which enables prioritization of experimentally validated and predicted mRNA targets was used. By applying an expression pairing tool, the analysis was focused on targets exhibiting altered expression in our analysis, finding miRNAs and their target genes with opposite or same expression. The resulting identified interactions were revalidated by RT-qPCR in another cohort of RCC patients. The predicted miRNA-mRNA interactions were also tested by functional analyses using miRNA knock-down and over expression experiments in renal cancer cell lines.

Results

Among the significantly differentially expressed miRNAs, we have identified 3 miRNAs (miR-146a, miR-128a and miR-17-5p) that were upregulated in primary tumors from patients without metastasis and down regulated in primary tumors from patients with metastasis. We have further identified the mRNA targets which expression were inversely correlated to these 3 miRNAs, and have been previously experimentally demonstrated in cancer setting in humans. Specifically we showed that BRAC1, MCM10, CDKN3, UHRF1, IL8 were downregulated and targeted by miR-146a-5p. The relation between these identifies target genes and miRNA-146a was validated in cell culture experiments.

Conclusions

We identified novel target genes of dysregulated miRNAs, which are involved in the transition from primary RCC without metastases into tumors generating distant metastasis.

Citation Format: Jean-Noel Billaud. Integrated microRNA and mRNA signature associated with the transition from the locally confined to the metastasized renal cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4373. doi:10.1158/1538-7445.AM2014-4373
Abstract 4377: Novel RNAi agent can control HCV replication
Authors: Kuroda Masahiko , Takanashi Masakatsu , Ohno Shinichiro , Murakami Yoshiki
Published: May 2015

Technique of RNA interference (RNAi) is important for investigating functional gene research and drug target. miRNA-122 (miR-122) is expressed abundantly in liver tissue, and it can control the Hepatitis C virus (HCV) replication. Locked Nucleic Acid (LNA)-miR-122 was shown to suppress HCV replication through inhibiting miR-122 function. Recently, anti-HCV therapy for chronic hepatitis C by LNA-miR-122 has been applied for clinical study in phase II. We developed alternative chemically modified sponge oligonucleotides (SO) for inhibition of interest miRNA function. In order to find more effective anti-viral agent, we attempted to compare the inhibition effects for viral replication between LNA-miR-122 and SO for miR-122.

SO contained triplicated binding sites to miR-122, composed of either DNA or RNA, which were combined with terephthalate or glycine. We chose three types of sequences complementary to target miR-122: one perfect match sequence and two imperfect match sequences (bubble, and bulge). The effects of SOs on HCV replication were assessed by using HCV replicon cells (OR6), which contained full-genome HCV with genotype 1b and luciferase reporter genes.

We compared the luciferase activity, the expression of HCV RNA, and the expression of HCV core protein in OR6 cells treated with LNA-miR-122 and several SO constructions. SO composed of terephthalate-bound RNA sequences with bulge-type imperfect complementarity was most effective in inhibiting HCV replication. By real-time qPCR analysis, the expression level of ISG15 and RIG-I in the OR6 cell treated with SO was not significantly higher than those treated with negative control (NC) or LNA. By XTT incorporation assay, the cell proliferation level in OR6 treated with SO was not also significantly affected as compared that treated with NC or LNA.

We investigated novel RNAi agent termed SO that could effectively suppress HCV replication as compared LNA-miR-122. SO treatment did not activate the endogenous IFN pathway nor induce the cell mortality. Therefore SO is promising as a novel anti-vial agent.

Citation Format: Masahiko Kuroda, Masakatsu Takanashi, Shinichiro Ohno, Yoshiki Murakami. Novel RNAi agent can control HCV replication. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4377. doi:10.1158/1538-7445.AM2014-4377
Abstract 4379: Identification and characterization of therapeutic targets via microRNA profiling in HBV-related hepatocellular carcinoma
Authors: Park Keon U. , Kim Jin Young , Hwang Ilseon , Ryoo Hun M. , Kim Sang-Woo , Lee Yun-Han
Published: May 2015

Hepatocellular carcinoma (HCC) is the most frequent type of liver cancer and it accounts for about 600,000 cancer deaths worldwide. Chronic infection with hepatitis B virus (HBV) is known to be responsible for most of HCC cases. HBV infections are especially common in Africa and some of Asian countries, including South Korea where 75% of HCC patients are infected with HBV. With traditional therapeutic strategies, such as surgical dissection or chemoembolization, 5-year survival rate of HCC patients is about 18%, demanding better understanding of molecular and cellular biology of the disease.

MicroRNAs (miRNAs) are small noncoding single-stranded RNA molecules about 21-25 nucleotides long. miRNAs are involved in many cellular processes, including cell proliferation, apoptosis, and cell differentiation. Recently, it has been reported that deregulation of miRNAs contributes to the development of different types of human cancers but their role in HCC pathogenesis remains to be fully understood.

In the present study, we performed a microarray-based genome-wide analysis of miRNA expression in 9 tissue samples from HCC patients and 7 noncancerous liver tissues to identify differentially expressed miRNAs. The expression of 183 and 84 miRNAs was found significantly up- and down-regulated in HCC samples compared with normal liver tissues, respectively (p < 0.05). Among prominent miRNAs are miR-17∼92 polycistronic oncomir, miR-200 family, miR-34, and miR-125b that are shown to be associated with HCC pathogenesis, demonstrating the validity of this miRNA profiling and warranting the identification and characterization of other miRNAs and their potential target genes.

Taken together, our study demonstrates miRNA profiling in HCC that may be used as a diagnostic purposes.

Citation Format: Keon Uk Park, Jin Young Kim, Ilseon Hwang, Hun Mo Ryoo, Sang-Woo Kim, Yun-Han Lee. Identification and characterization of therapeutic targets via microRNA profiling in HBV-related hepatocellular carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4379. doi:10.1158/1538-7445.AM2014-4379
Abstract 4381: MiR-205 and Trastuzumab: Potential as adjuvant therapeutic tool and predictive biomarker
Authors: D'Ippolito Elvira , Piovan Claudia , Plantamura Ilaria , Giussani Marta , Casalini Patrizia , Campiglio Manuela , Tagliabue Elda , Iorio Marilena V.
Published: May 2015

Despite the improvement in the management of HER2+ breast cancer patients with the approval of Trastuzumab in the clinical practise, and the success rate of this treatment, a still considerable percentage of patients do not respond or eventually develop a secondary resistance, leading to relapse and poor outcome. A crucial issue is represented by the urgent need of biomarkers able to predict the response to treatment, and certainly of new therapeutic tools to counteract the resistance mechanisms. It is known that resistance to anti-HER2 therapies can be due to escape mechanisms triggered by alternative receptors: here we show that HER3 silencing, either mediated by miR-205, known to directly target the receptor (Iorio MV et al., 2009) or by a siRNA specific against HER3, is able to improve the responsiveness to Trastuzumab, reducing tumor cell growth and colony formation capability. This effect seems to be mediated by impairment of the Akt-mediated pathway.

Finally, evaluating miR-205 expression in a series of 51 HER2+ breast cancer patients treated with Trastuzumab in adjuvant setting, we observed that miR-205 is significantly associated with outcome: setting the median expression as cut-off, and performing a contingency analysis (Fisher's exact test), miR-205 expression was above the median in a significantly (p=0.03) higher percentage of responders versus non responders patients (61% versus 26%).

In summary, here we show that miR-205 improves the responsiveness to Trastuzumab treatment at least partially though HER3 silencing, and associated to outcome of patients treated in adjuvant setting, thus representing a potential adjuvant tool and predictive biomarker.

Citation Format: Elvira D'Ippolito, Claudia Piovan, Ilaria Plantamura, Marta Giussani, Patrizia Casalini, Manuela Campiglio, Elda Tagliabue, Marilena V. Iorio. MiR-205 and Trastuzumab: Potential as adjuvant therapeutic tool and predictive biomarker. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4381. doi:10.1158/1538-7445.AM2014-4381
Abstract 4382: Relative expression of miR200 microRNAs and ERBB family negative regulator Mig6 in estimation of EMT status and erlotinib sensitivity
Authors: Izumchenko Eugene G. , Chang Xiaofei , Michailidi Christina , Kagohara Luciane , Ravi Rajani , Brait Mariana , Bedi Atul , Sidransky David
Published: May 2015

While sensitizing mutations in the tyrosine kinase domain of epidermal growth factor receptor (EGFR) render tumors more sensitive to EGFR tyrosine kinase inhibitors (TKIs), these genetic alterations are present in only a minority of patients who respond to treatment and are rare in tumors other than NSCLCs. Thus, clinical benefit of TKIs in a subset of patients with wild-type EGFR may be underestimated due to the lack of appropriate predictive markers to stratify them from larger number of patients who do not response. It has long been observed that the response of anti-EGFR agents is associated with epithelial and mesenchymal transition (EMT) in multiple types of tumors without known EGFR mutations. However, little is known about the molecular mechanisms underlying this association, and no EMT-associated biomarkers of clinical utility have been successfully developed. Here we show that during the TGFβ-induced EMT, upregulation of mitogen-inducible gene 6 (Mig6), a negative regulator of EGFR, by microRNAs 200 (miR200) family is leading to reduced EGFR dependence, initiation of kinase switch in mesenchymal cells and subsequent insensitivity of these cells to EGFR inhibition. Moreover, we found that the ratio between mRNA levels of Mig6 and miR200c highly correlated with erlotinib sensitivity and EMT status in panel of 25 cancer cell lines of different tissue origins. Furthermore, analysis of directly xenografted human lung and pancreatic tumors (tumorgrafts) bearing wtEGFR demonstrated a higher response to EGFR inhibitor erlotinib for models with low Mig6 (mRNA)/miR200 ratio. Collectively, our data demonstrates that during the EMT-associated evolution of resistance to EGFR inhibitors, Mig6 expression is highly correlated with EMT status and identifies the ratio of Mig6 mRNA to miR200 as a novel, reliable and cost-effective predictor of biologic and clinical response to TKIs.

Citation Format: Eugene G. Izumchenko, Xiaofei Chang, Christina Michailidi, Luciane Kagohara, Rajani Ravi, Mariana Brait, Atul Bedi, David Sidransky. Relative expression of miR200 microRNAs and ERBB family negative regulator Mig6 in estimation of EMT status and erlotinib sensitivity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4382. doi:10.1158/1538-7445.AM2014-4382
Abstract 4383: Effects of inhibition of upregulated microRNAs in canine histiocytic sarcoma
Authors: Gregory-Bryson Emmalena J. , Parys Maciej , Kiupel Matti , Yuzbasiyan-Gurkan Vilma
Published: May 2015

Histiocytic diseases encompass a spectrum of proliferative diseases in humans and dogs. While these orphan malignancies are rare in the human, histiocytic diseases are relatively frequent in certain breeds of dog. In the dog, these diseases range from benign histiocytoma to malignant histiocytic sarcoma (HS). Disseminated HS has a poor prognosis and lacks effective treatment options in both humans and dogs. The overall goal of this study is to unravel the mechanisms of tumorigenesis in histiocytic diseases and identify better treatments. Our studies have focused on microRNAs (miRNAs), which are master regulators of gene expression and may have a significant role in tumorigenesis in histiocytic diseases. MiRNA profiling of canine histiocytic diseases was conducted on cases of reactive histiocytosis, HS, and hemophagocytic HS. These samples were compared to normal canine histiocytes derived from peripheral blood or peritoneal fluid. Several miRNAs were identified to be upregulated in the disease samples and were selected for validation by qRT-PCR. From these results, two miRNA targets were selected for further evaluation. We are probing the significance of the upregulation of these miRNAs by inhibiting their function in canine HS cell lines using chemical miRNA inhibitors and sponge constructs designed to competitively bind the upregulated miRNAs, thus preventing them from acting on their targets. Our results to date indicate that inhibiting these miRNAs in the canine HS cell line, DH82, decreases growth rate by as much as 39%. Studies into other aspects of tumorigenicity potentially affected by the inhibition of these miRNAs are underway. Our preliminary data suggests these miRNAs themselves may be effective therapeutic targets for histiocytic diseases. Additionally, further analysis of the pathways regulated by these miRNAs may identify critical gene targets in HS tumorigenesis and thus increase our understanding of these malignancies and discover novel and effective therapies. Comparative studies have the potential to provide opportunities for advancement in these orphan malignancies, and in this case, improve clinical outcome in dogs and humans.

Citation Format: Emmalena J. Gregory-Bryson, Maciej Parys, Matti Kiupel, Vilma Yuzbasiyan-Gurkan. Effects of inhibition of upregulated microRNAs in canine histiocytic sarcoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4383. doi:10.1158/1538-7445.AM2014-4383
Abstract 4387: Up-regulation of VHL by miR-1273C inhibits renal cell carcinoma
Authors: Lee Chang Woo , Kang Moo Rim , Yun Jieun , Oh Soo Jin , Kang Jong Soon
Published: May 2015

VHL (Von Hippel-Lindau) is a known tumor suppressor that binds to hypoxia inducible factor (HIF) and induces ubiquitin-mediated degradation. VHL is also involved in the regulation of tumor angigoenesis, cell cycle regulation, and apoptosis. Recent studies have reported that double strand RNA complementary to target promoter sequence can induce gene expression in several cancer cells and this is called small activating RNA (saRNA). By scanning gene promoters in silico for sequences complementary to known miRNAs, we identified 32 putative miRNAs target site in the promoter of VHL. Experimental validation identified two miRNAs (miR-1273C and miR-4512) that induce VHL expression in 769-P renal cancer cells. Another dsRNA molecule (dsVHL-101) complementary to the putative miR-1273C target site also induced VHL expression. Functional studies revealed that transfection of miR-1273C and dsVHL-101 inhibited cell proliferation and induced apoptosis in dose dependent manner. Furthermore, knockdown experiments confirmed that induction of VHL and apoptosis by miR-1273C and dsVHL-101 required the miRNA maturation protein Ago2 and nuclear transport protein TNRC6A. This study suggests that miRNAs play an inhibiting role in the progression of cancer cells by VHL gene expression, which may be a potential therapeutic approach in the future.

Citation Format: Chang Woo Lee, Moo Rim Kang, Jieun Yun, Soo Jin Oh, Jong Soon Kang. Up-regulation of VHL by miR-1273C inhibits renal cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4387. doi:10.1158/1538-7445.AM2014-4387
Abstract 4390: Non-coding RNAs in EGFR therapy resistance in breast cancer
Authors: Borrero-García Luis D. , Castillo-Pichardo Linette , Redis Roxana S. , Calin George A. , Dharmawardhane Suranganie
Published: May 2015

The purpose of this study is to identify novel mechanisms of resistance to epidermal growth factor receptor (EGFR) targeted therapies. The initial success of EGFR targeted therapies such as gefitinib and lapatinib has been confounded by intrinsic or acquired therapy resistance. Emerging data, including our studies, show drug-induced dysregulation of non-coding RNAs (ncRNAs) that may downregulate multiple effectors of chemoresistance by transcriptional or post-transcriptional regulation. To investigate the role of ncRNAs in regulation of EGFR therapy resistance, we created syngeneic therapy sensitive and resistant breast cancer (BC) cell lines by exposing therapy sensitive SKBR3 and BT-474 cells to different concentrations of gefitinib or lapatinib. Differentially expressed ncRNAs in resistant and sensitive cells were identified from quantitative RT-PCR analysis and their targets detected by Western blot. A long ncRNA (lncRNA) that we have named Colon Cancer Associated Transcript 2 (CCAT2) (Ling et al., Genome Res. 2013, 23:1446-61) was downregulated in EGFR/HER2 therapy resistant BC cells. The microRNA miR -221/222 was upregulated in parallel with decreased CCAT2. Increased miR-221/222 and decreased miR-200 family have been associated with cancer malignancy and epithelial to mesenchymal transition (EMT), a hallmark of therapy resistance. Accordingly, miR-200a was downregulated in EGFR therapy resistant BC cells. miR-200 family plays an important role in suppression of EMT by downregulation of zinc finger E-box binding homeobox (Zeb)1/2 and β-catenin. Zeb 1/2 are negative regulators of E-cadherin, and β-catenin is a potent pro-cancer transcriptional activator in the absence of an E-cadherin axis. Results show upregulation of Zeb1, β-catenin and its transcriptional effector c-Myc, and stem cell-like marker CD44, while E-cadherin was downregulated in the E-cadherin positive BT-474 cells. We also found downregulation of miR-221/222 targets, PTEN and APAF1, in the SKBR3 resistant variants, which is consistent with the upregulation of miR-221/222 expression. In conclusion, this data suggest that downregulation of CCAT2 and miR-200 family, and upregulation of miR-221/222 contributes to EGFR targeted therapy resistance. Therefore, targeting these ncRNAs maybe a viable alternative to overcoming therapy resistance in BC.

Citation Format: Luis D. Borrero-García, Linette Castillo-Pichardo, Roxana S. Redis, George A. Calin, Suranganie Dharmawardhane. Non-coding RNAs in EGFR therapy resistance in breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4390. doi:10.1158/1538-7445.AM2014-4390
Abstract 4391: Multi-modal nanomedicine for glioblastoma
Authors: Ofek Paula , Calderon Marcelo , Sheikhi-Mehrabadi Fatemeh , Ferber Shiran , Haag Rainer , Satchi-Fainaro Ronit
Published: May 2015

Glioblastoma multiforme (GBM) is an aggressive primary neoplasm of the brain that exhibit notable refractivity to standard treatment regimens. Recent large-scale molecular profiling has revealed deregulated molecular networks as potential targets for therapeutic development. MicroRNAs (miRNAs) are noncoding RNA molecules which act as post-transcriptional regulators of specific messenger RNA transcripts. miRNAs play major roles in normal developmental processes, and their deregulation significantly contributes to various aspects of carcinogenesis.

Nevertheless, in vivo delivery of small interfering RNA (siRNA) and miRNA remains a crucial challenge for their therapeutic success. siRNAs and miRNAs on their own are not taken-up by most mammalian cells in a way that preserves their activity. In order to circumvent these limitations, we developed a cationic carrier system, which can strongly improve its stability, intracellular trafficking and silencing efficacy. Polyglycerol (PG)-Amine, a water-soluble polyglycerol-based hyperbranched polymer accumulates in the tumor microenvironment due to the enhanced permeability and retention (EPR) effect, and therefore, represents an ideal nanocarrier for antitumor biological agents.

Using our novel nanocarrier, we have studied the expression targets and functional effects of miR-34a in several human glioblastoma cell lines and human tissue samples. miR-34a levels inversely correlated to their target gene levels measured in the same cell lines or tissue. Transient transfection of PG-NH2-miR-34a polyplex into glioblastoma cells strongly inhibited cell proliferation, cell cycle progression, and cell migration. Consequently, we performed an in vivo experiment and achieved a significant tumor growth inhibition effect following treatment with PG-NH2-miR-34a polyplex in a human glioblastoma mouse model.

We further characterized the synergistic effect of combining PG-NH2-miR-34a polyplex with chemotherapy and achieved promising results. Together, our findings show that PG-NH2 efficiently delivers anticancer miRNAs to glioblastoma cells and suppresses brain tumor growth. These results suggest that our polyplex could serve as a potential nanomedicine for glioblastoma.

Citation Format: Paula Ofek, Marcelo Calderon, Fatemeh Sheikhi-Mehrabadi, Shiran Ferber, Rainer Haag, Ronit Satchi-Fainaro. Multi-modal nanomedicine for glioblastoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4391. doi:10.1158/1538-7445.AM2014-4391
Abstract 4394: Genistein downregulates onco-miR-1260b and inhibits Wnt-signaling in renal cancer cells
Authors: Hirata Hiroshi , Ueno Koji , Tanaka Yuichiro , Tabatabai Z.Laura , Nakajima Koichi , Hinoda Yuji , Ishii Nobuhisa , Dahiya Rajvir
Published: May 2015

Introduction and Objective: Wnt signaling plays an important role in renal cancer and that is modulated by genistein in other cancers. Recently microRNAs have emerged as new regulators of gene expression. Thus we focused on microRNAs to examine the regulatory mechanism of genistein on the Wnt signaling pathway in RCC.

Methods: Initially we investigated the effect of genistein on Wnt signaling (TCF reporter assays) in renal cancer cells and using microarray identified candidate miRNAs whose expression was decreased by genistein. We performed functional analyses and investigated the relationship between miRNA expression and renal cancer patient outcomes. We also did 3′UTR luciferase assays to look at direct miRNA regulation of Wnt signaling related genes.

Results: Genistein promoted apoptosis while inhibiting RCC cell proliferation and invasion. Genistein also decreased TCF reporter activity in RCC cells. We found that miR-1260b was highly expressed and significantly down-regulated by genistein in RCC cells. The expression of miR-1260b was significantly higher in renal cancer tissues compared to normal and significantly related to over-all shorter survival. Additionally miR-1260b promoted renal cancer cell proliferation and invasion in RCC cells. The 3′UTR luciferase activity of target genes (sFRP1, Dkk2, Smad4) was significantly decreased and their protein expression significantly up-regulated in miR-1260b inhibitor transfected renal cancer cells.

Conclusions: Our data suggests that genistein inhibited Wnt signaling by regulating miR-1260b expression in renal cancer cells.

Source of Funding: Grants RO1CA138642, RO1CA130860, RO1CA160079, I01BX001123, VA Merit Review and VA Program Project (PI: R. Dahiya).

Citation Format: Hiroshi Hirata, Koji Ueno, Yuichiro Tanaka, Z.Laura Tabatabai, Koichi Nakajima, Yuji Hinoda, Nobuhisa Ishii, Rajvir Dahiya. Genistein downregulates onco-miR-1260b and inhibits Wnt-signaling in renal cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4394. doi:10.1158/1538-7445.AM2014-4394
Abstract 4398: MicroRNA-203 enhances radiosensitivity of human malignant glioma cells
Authors: Hwang Yeohyeon , Lee David J. , Choi Eun Jung , Cho Bong Jun , Kim In-Ah
Published: May 2015

Glioblastoma multiform (GBM) is the most common, lethal and aggressive type of primary brain tumor. Despite the improvement of surgical and chemo/radiotherapeutic techniques, the prognosis for GBM is still poor, with median survival of 9-12 months. The occurrence of radio-resistance is one of the major obstacles to treat the GBM. Aberrant expression of miRNAs has been demonstrated to be involved in the initiation, progression, and metastasis of cancers. miRNA expression profiling studies revealed that a number of miRNA were dysregulated in GBM. Here, we investigated the potential role of miR-203, which is one of the downregulated miRNAs, in the modulation of radio-sensitivity in GBM. Transiently overexpressed miR-203 sensitized U251 malignant glioma cells to radiation concurrent with the downregulation of AKT activity. Overexpression of miR-203 prolonged radiation-induced γH2AX foci formation and downregulation of DNA-dependent protein kinases, suppressed invasion, migration potential and vasculogenic mimicry formation. In contrast, antisense-mediated inhibition of miR-203 expression results in decreased radio-sensitivity and features of Epithelial-Mesenchymal Transition (EMT). Taken together, our findings suggest that the miR-203 could be a useful target for overcoming the radio-resistance of GBM.

Citation Format: Yeohyeon Hwang, David J. Lee, Eun Jung Choi, Bong Jun Cho, In-Ah Kim. MicroRNA-203 enhances radiosensitivity of human malignant glioma cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4398. doi:10.1158/1538-7445.AM2014-4398
Abstract 4399: Somatic HIF2A mutations identified in a new syndrome with multiple paragangliomas and somatostatinomas associated with polycythemia
Authors: Yang Chunzhang , Pacak Karel , Zhuang Zhengping
Published: May 2015

Hypoxia inducible factors (HIFs) control the cellular response to hypoxia and when dysregulated, contribute to tumorigenesis. We identified somatic HIF2A mutations in patients with a new disease syndrome of multiple paragangliomas and somatostatinomas associated with polycythemia. Five different somatic mutations in HIF2A were identified. All of them have a single amino acid substitution in the evolutionarily conserved oxygen-dependent degradation (ODD) domain resulting in disrupting the HIF-2α hydroxylation by prolyl hydroxylase domain-2 containing protein (PHD2). Changes of HIF-2α hydroxylation resulted in the stabilization of HIF-2α and cellular psuedohypoxia, that trigger activation of hypoxia-related genes expression and, dysregulate hematopoiesis leading to tumorigenesis. These results show for the first time that the intrinsic HIF mutations are present in tumors.

Citation Format: Chunzhang Yang, Karel Pacak, Zhengping Zhuang. Somatic HIF2A mutations identified in a new syndrome with multiple paragangliomas and somatostatinomas associated with polycythemia. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4399. doi:10.1158/1538-7445.AM2014-4399
Abstract 4400: The let-7 microRNA binding site variant in the KRAS 3′-UTR is not associated with the risk of head and neck cancer
Authors: Dalay Nejat , Demokan Semra , Suoglu Yusufhan , Yilmazer Rasim , Ulusan Murat
Published: May 2015

The KRAS gene is activated by somatic mutations in many cancer types. However, KRAS mutations are relatively rare in squamous cell carcinomas. In squamous cell cancers of the head and neck (HNSCC) amplification of the KRAS gene has been shown to promote tumor growth. miRNAs are short non-coding RNAs which play an important role as regulators of gene expression. They bind to the 3′-untranslated regions (UTRs) of the mRNAs and prevent translation of their target genes. SNPs in the miRNA binding sites are associated with disease risk and prognosis. The let-7 family of miRNAs regulate multiple oncogenes including the KRAS gene and have been shown to play a critical role in different cancer types. A functional polymorphism in the KRAS gene, not included in the GWAS platforms has been identified by candidate gene approach and was found to be a genetic marker of cancer risk and increased susceptibility to the carcinogenic effects of tobacco smoke. The polymorphism is referred to as the LCS6 (let-7 complementary site 6) variant and disrupts the let-7 binding site leading to higher KRAS expression. Such an increase in KRAS expression associated with the variant allele may represent an alternative form of KRAS activation in HNSCC and could lead to impairment of the EGFR signaling. In this study we evaluated the frequency of the KRAS variant in 216 patients with head and neck cancer and 85 healthy individuals. DNA was extracted from whole blood prior to chemotherapy or radiotherapy. The variant allele was analyzed by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. Genotype and allele frequencies were evaluated using the De-Finetti case control program. 13 % of the patients were heterozygous and 3 patients (1.5 %) were homozygous for the variant allele. The polymorphism was present in heterozygous form in 12 % of the controls. No homozygous individual was detected in the control group. The frequencies of the variant allele were 92 % and 94 % in the patients and controls, respectively. Our data indicate that the KRAS let-7 LCS6 variant allele is not associated with an increased risk of HNSCC.

Citation Format: Nejat Dalay, Semra Demokan, Yusufhan Suoglu, Rasim Yilmazer, Murat Ulusan. The let-7 microRNA binding site variant in the KRAS 3′-UTR is not associated with the risk of head and neck cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4400. doi:10.1158/1538-7445.AM2014-4400
Abstract 4405: AXL receptor tyrosine kinase is associated with the prognosis of patients with esophageal squamous cell carcinoma
Authors: Yang Pei-Wen , Hsieh Min-Shu , Huang Ya-Chuan , Chiang Tzu-Hsuan , Lee Jang-Ming
Published: May 2015

PURPOSE:

The AXL receptor tyrosine kinase has been suggested as a prognostic factor and a therapeutic target in esophageal adenocarcinoma. Whether AXL play some role in the prognosis of esophageal squamous cell carcinoma (ESCC) is unknown. We aim to investigate the association of AXL expression in tumor tissues with the prognosis of patients with ESCC.

PATIENTS AND METHODS:

The study was analyzed retrospectively. A total of 57 patients diagnosed with ESCC were enrolled in the study. AXL expression in esophageal timorous tissues was detected by immunnohistochemisty (IHC), and was correlated with the overall survival (OS) or progression-free survival (PFS) of patients by multivariate Cox regression analysis and Kaplan-Meier survival function.

RESULTS:

AXL could be detected in 38 patients (66.7%). Elevated expression of AXL was associated with increased risk of both death and recurrence (HR[95 % CI]=1.46 [1.05-2.04], Ptrend=0.026 in death and HR[95 % CI]=1.75[1.24-2.48], Ptrend=0.002 in recurrence). Patents expressing high levels of AXL (n=25, 43.9 %) exhibited a 2.15 fold increased risk of recurrence compared to those absence or with low level of AXL (HR[95 % CI]=2.15[1.08-4.28], P=0.029). Kaplan-Meier survival function demonstrated that the progression-free duration was significantly different among the patients expressing different levels of AXL (log-rank P=0.029).

CONCLUSION:

Expression of AXL in esophageal tumor tissues is a prognostic predictor of ESCC. The results revealed AXL could also be a therapeutic target of ESCC.

Citation Format: Pei-Wen Yang, Min-Shu Hsieh, Ya-Chuan Huang, Tzu-Hsuan Chiang, Jang-Ming Lee. AXL receptor tyrosine kinase is associated with the prognosis of patients with esophageal squamous cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4405. doi:10.1158/1538-7445.AM2014-4405
Abstract 4408: Her2 C terminal PDZ binding domain interacting with DLG1 is required for radioresistance through induction of EMT and loss of epithelial polarity
Authors: Lin Dong , Zhang Xiaodi , Eldridge Angela , Fan Ming , Menaa Cheikh , Li Jianjian
Published: May 2015

The tyrosine kinase receptor HER2 (ErbB2/neu) is predominantly localized to the basolateral membrane of the epithelium and has been implicated in mammary tumorigenesis as well as in resistance to chemotherapy and radiation. Here we demonstrate that HER2 interacts with discs large 1 (DLG1) that is one of PDZ domain proteins expressed at the basolateral membrane of human breast epithelial cells and plays an important role in the establishment and maintenance of epithelial polarity in Drosophila. However, either loss of the last 6 C-terminal amino acids (HER2-Δ1250-1255) or a valine-to-alanine C-terminal substitution (HER2-V1255A) in HER2, abrogates the interaction with DLG1. In contrast, either PDZ domain 1 or 3 within Dlg1 is required for interaction with HER2. Moreover, HER2-Δ1250-1255- or HER2-V1255A-expressing MCF10A human breast epithelial cells show the reduction of mesenchymal-to-epithelial transition (EMT) proteins including vimentin and Snail. In addition, HER2-wt cells promotes EMT as shown by down-regulation of E-cadherin and upregulation of vimentin and Snail. Taken together, these results indicate that C-terminal PDZ binding domain in HER2 modulates biological functions of HER2. These results reveal new insight into the structure and function of HER2, which may guide the design and development of new anti-cancer targets to treat HER2-positive breast cancer.

Citation Format: Dong Lin, Xiaodi Zhang, Angela Eldridge, Ming Fan, Cheikh Menaa, Jianjian Li. Her2 C terminal PDZ binding domain interacting with DLG1 is required for radioresistance through induction of EMT and loss of epithelial polarity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4408. doi:10.1158/1538-7445.AM2014-4408