Development of Neonatal Airway Management Simulator for Evaluation of Tracheal Intubation

The long-term goal of this study is a training system that can simulate medical cases and advise physicians based on quantitative evaluation of neonatal resuscitation. In this paper, we designed and manufactured a neonatal airway management simulator for quantitative evaluation of tracheal intubation. This robotic simulator is equipped with 25 sensors of 6 types, which detect motions that lead to complications, inside the manikin replicated a neonate. A performance experiment of the developed sensor and an evaluation experiment with physicians were conducted. We observed that an erroneous operation in the laryngoscopy can be detected by the sensors in our simulator.

Suppressor effect of catechol-O-methyltransferase gene in prostate cancer

Catechol-estrogens can cause genetic mutations and to counteract their oncogenicity, the catechol-O-methyltransferase (COMT) gene is capable of neutralizing these reactive compounds. In this study, we determined the functional effects and regulation of COMT in prostate cancer. Both the Cancer Genome Atlas (TCGA) and immunohistochemical analysis of clinical specimens demonstrated a reduction of COMT expression in prostate cancer. Also, western analyses of prostate cancer cell lines show COMT levels to be minimal in DuPro and DU145 and thus, these cells were used for further analyses. Re-expression of COMT led to suppressed migration ability (wound healing assay) and enhanced apoptosis (flow cytometric analyses), and when challenged with 4-hydroxyestradiol, a marked reduction of cell proliferation (MTT assay) was observed. Xenograft growth in athymic mice also resulted in inhibition due to COMT. As a mechanism, western analyses show cleaved CASP3 and BID were increased whereas XIAP and cIAP2 were reduced due to COMT. As COMT expression is low in prostate cancer, its regulation was determined. Databases identified several miRNAs capable of binding COMT and of these, miR-195 was observed to be increased in prostate cancer according to TCGA. Real-time PCR validated upregulation of miR-195 in clinical prostate cancer specimens as well as DuPro and DU145 and interestingly, luciferase reporter showed miR-195 capable of binding COMT and overexpressing miR-195 could reduce COMT in cells. These results demonstrate COMT to play a protective role by activating the apoptosis pathway and for miR-195 to regulate its expression. COMT may thus be a potential biomarker and gene of interest for therapeutic development for prostate cancer.

Role of miR-182/PDCD4 axis in aggressive behavior of prostate cancer in the African Americans

Background

Prostate cancer is one of the most commonly diagnosed cancers among men. African Americans (AA) are at an increased risk of developing prostate cancer compared to European Americans (EA). miRNAs play a critical role in these tumors, leading to tumor progression. In this study, we investigated the role of miR-182 in racial disparity in prostate cancer.

Results

We found significantly increased levels of miR-182 in prostate cancer tissues compared to BPH. Also, miR-182 shows increased expression in AA prostate cancer cell line and tissue samples compared to EA. We performed biochemical recurrence (BCR) - free survival time in AA and EA patients and found that high miR-182 expression had significantly shorter BCR-free survival than patients with low miR-182 expression (P = 0.031). To elucidate the role of miR-182, we knocked down miR-182 in EA (DU-145 and LNCaP) and AA (MDA-PCa-2b) cell lines and found an increase in apoptosis, arrest of the cell cycle, and inhibition of colony formation in the AA cell line to a greater extent than EA cell lines.

Conclusions

Our results showed that PDCD4 is a direct miR-182 target and its inhibition is associated with aggressiveness and high Gleason grade in prostate cancer among AA. These findings show that miR-182 is highly expressed in AA patients and miR-182 may be a target for effective therapy in AA patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08723-6.

A lncRNA TCL6-miR-155 Interaction Regulates the Src-Akt-EMT Network to Mediate Kidney Cancer Progression and Metastasis

Metastasis is the leading cause of mortality from kidney cancer, and understanding the underlying mechanism of this event will provide better strategies for its management. Here we investigated the biological, functional, and clinical significance of lncTCL6 and its interacting miR-155 in clear cell renal cell carcinoma (ccRCC). We employed a comprehensive approach to investigate the lncTCL6-miR-155-Src/Akt-mediated epithelial-to-mesenchymal transition (EMT) pathway as a novel regulatory mechanism in ccRCC progression. Expression analyses revealed that lncTCL6 is downregulated in ccRCC compared with normal tissues. Overexpression of lncTCL6 in ccRCC cell lines impaired their oncogenic functions, such as cell proliferation and migration/invasion, and induced cell-cycle arrest and apoptosis; conversely, depletion of lncTCL6 rescued these phenotypic effects. Furthermore, lncTCL6 directly interacted with miR-155. Unlike lncTCL6, miR-155 was overexpressed in ccRCC. Stable knockdown of miR-155 phenocopied the effects of lncTCL6 overexpression. Conversely, reconstitution of miR-155 and suppression of lncTCL6 in noncancerous renal cell HK2 induced tumorigenic characteristics. Patients with higher expression of lncTCL6 and lower expression of miR-155 had better survival probability. When overexpressed, lncTCL6 recruited STAU1 and mediated decay of Src mRNA, followed by a marked downregulation of an integrated network of Src target genes involved in migration, invasion, and EMT. However, the interaction between miR-155 and lncTCL6 attenuated the regulatory role of lncTCL6 on Src-mediated EMT. In conclusion, this study is the first report documenting the lncTCL6-miR155-Src/Akt/EMT network as a novel regulatory mechanism in aggressive ccRCC and a promising therapeutic target to inhibit renal cancer. SIGNIFICANCE: This study's investigation of noncoding RNA interactions in renal cell carcinoma identify miRNA-155-lncRNA TCL6-mediated regulation of the Src-Akt-EMT network as a novel mechanism of disease progression and metastasis.

Role of the PI3K/Akt pathway in cadmium induced malignant transformation of normal prostate epithelial cells

This study investigated the role of the PI3K/Akt pathway in cadmium (Cd) induced malignant transformation of normal prostate epithelial (PWR1E and RWPE1) cells. Both PWR1E and RWPE1 cells were exposed to 10 μM Cd for one year and designated as Cd-PWR1E and Cd-RWPE1. Cd-RWPE1 cells robustly formed tumors in athymic nude mice. Functionally, Cd-exposure induced tumorigenic attributes indicated by increased wound healing, migration and invasion capabilities in both cell lines. RT²-array analysis revealed many oncogenes including P110α, Akt, mTOR, NFKB1 and RAF were induced whereas tumor suppressor (TS) genes were attenuated in Cd-RWPE1. This was validated by individual quantitative-real-time-PCR at transcriptional and by immunoblot at translational levels. These results were consistent in Cd-PWR1E vs parental PWR1E cells. Gene Set Enrichment Analysis revealed that five prostate cancer (PCa) related pathways were enriched in Cd-exposed cells compared to their normal controls. These pathways include the KEGG- Pathways in cancer, Prostate Cancer Pathway, ERBB, Apoptosis and MAPK pathways. We selected up- and down-regulated genes randomly from the PI3K/Akt pathway array and profiled these in the TCGA/GDC prostate-adenocarcinoma (PRAD) patient cohort. An upregulation of oncogenes and downregulation of TS genes was observed in PCa compared to their normal controls. Taken together, our study reveals that the PI3K/Akt signaling is one of the main molecular pathways involved in Cd-driven transformation of normal prostate epithelial cells to malignant form. Understanding the molecular mechanisms involved in the Cd-driven malignant transformation of normal prostate cells will provide a significant insight to develop better therapeutic strategies for Cd-induced prostate cancer.

LncRNA CDKN2B-AS1/miR-141/cyclin D network regulates tumor progression and metastasis of renal cell carcinoma

The molecular heterogeneity of renal cell carcinoma (RCC) complicates the therapeutic interventions for advanced metastatic disease and thus its management remains a significant challenge. This study investigates the role of the lncRNA CDKN2B-AS1 and miR-141-3p interactions in the progression and metastasis of kidney cancer. Human renal cancer cell lines (ACHN and Caki1), normal RPTEC cells, tissue cohorts, and a series of in vitro assays and in vivo mouse model were used for this study. An overexpression of CDKN2B-AS1 was observed in RCC compared to normal samples in TCGA and our in-house SFVAMC tissue cohorts. Reciprocally, we observed reduced expression of miR-141 in RCC compared to normal in the same cohorts. CDKN2B-AS1 shares regulatory miR-141 binding sites with CCND1 and CCND2 genes. Direct interactions of CDKN2B-AS1/miR-141/Cyclin D1-D2 were confirmed by RNA immunoprecipitation and luciferase reporter assays indicating that CDKN2B-AS1/miR-141/Cyclin D1-D2 acts as a ceRNA network in RCC. Functionally, attenuation of CDKN2B-AS1 and/or overexpression of miR-141 inhibited proliferation, clonogenicity, migration/invasion, induced apoptosis in vitro and suppressed tumor growth in xenograft mouse model. Further, overexpression of CDKN2B-AS1 is positively correlated with poor overall survival of RCC patients. Expression of miR-141 also robustly discriminated malignant from non-malignant tissues and its inhibition in normal RPTEC cells induced pro-cancerous characteristics. CDKN2B-AS1 attenuation or miR-141 overexpression decreased CCND1/CCND2 expression, resulting in reduced RAC1/pPXN that are involved in migration, invasion and epithelial-mesenchymal transition. This study, for the first time, deciphered the role of CDKN2B-AS1/miR-141/Cyclin D axis in RCC and highlights this network as a promising therapeutic target for the regulation of EMT driven metastasis in RCC.

Activation of the Erk/MAPK signaling pathway is a driver for cadmium induced prostate cancer

PURPOSE

Cadmium (Cd) is reported to be associated with carcinogenesis. The molecular mechanisms associated with Cd-induced prostate cancer (PCa) remain elusive.

MATERIALS AND METHODS

RWPE1, PWR1E and DU 145 cells were used. RT2 Profiler Array, real-time-quantitative-PCR, immunofluorescence, cell cycle, apoptosis, proliferation and colony formation assays along with Gene Set Enrichment Analysis (GSEA) were performed.

RESULT

Chronic Cd exposure of non-malignant RWPE1 and PWR1E cells promoted cell survival, proliferation and colony formation with inhibition of apoptosis. Even a two-week Cd exposure of PCa cell line (DU 145) significantly increased the proliferation and decreased apoptosis. RT2 profiler array of 84 genes involved in the Erk/MAPK pathway revealed induction of gene expression in Cd-RWPE1 cells compared to RWPE1. This was confirmed by individual TaqMan gene expression analysis in both Cd-RWPE1 and Cd-PWR1E cell lines. GSEA showed an enrichment of the Erk/MAPK pathway along with other pathways such as KEGG-ERBB, KEGG-Cell Cycle, KEGG-VEGF, KEGG-Pathways in cancer and KEGG-prostate cancer pathway. We randomly selected upregulated genes from Erk/MAPK pathway and performed profile analysis in a PCa data set from the TCGA/GDC data base. We observed upregulation of these genes in PCa compared to normal samples. An increase in phosphorylation of the Erk1/2 and Mek1/2 was observed in Cd-RWPE1 and Cd-PWR1E cells compared to parental cells, confirming that Cd-exposure induces activation of the Erk/MAPK pathway.

CONCLUSION

This study demonstrates that Erk/MAPK signaling is a major pathway involved in Cd-induced malignant transformation of normal prostate cells. Understanding these dominant oncogenic pathways may help develop optimal therapeutic strategies for PCa.

Abstract B069: Upregulation of miR-130b contributes to risk of poor prognosis and racial disparity in African-American prostate cancer

Prostate cancer (PC) incidence and mortality rates are higher in African-American (AA) than in European-American (EA) men. The main objective of this study was to elucidate the role of miR-130b as a contributor to PC health disparity in AA patients. We also determined whether miR-130b is a prognostic biomarker and a new therapeutic candidate for AA PC. A comprehensive approach of using cell lines, tissue samples and the TCGA database was employed. We performed a series of functional assays such as cell proliferation, migration, invasion, RT2-PCR-array, qRT-PCR, cell cycle, luciferase reporter, immunoblot and immunohistochemistry. Various statistical approaches such as Kaplan-Meier, Uni- and Multivariate analyses were utilized to determine the clinical significance of miR-130b. Our results showed that elevated levels of miR-130b correlated with race disparity and PSA levels/failure and acted as an independent prognostic biomarker for AA patients. Two tumor suppressor genes, CDKN1B and FHIT, were validated as direct functional targets of miR-130b. We also found race-specific cell cycle pathway activation in AA PC patients. Functionally, miR-130b inhibition reduced cell proliferation, colony formation, migration/invasion and induced cell cycle arrest. Inhibition of miR-130b modulated critical PC related biological pathways in AA compared to EA PC patients. In conclusion, attenuation of miR-130b expression has tumor suppressor effects in AA PC. miR-130b is a significant contributor to PC racial disparity as its overexpression is a risk factor for poor prognosis in AA PC patients. Thus, regulation of miR-130b may provide a novel therapeutic approach for the management of PC in AA patients.

Citation Format: Yutaka Hashimoto, Marisa Shiina, Yuichiro Tanaka, Rajvir Dahiya, Shahana Majid. Upregulation of miR-130b contributes to risk of poor prognosis and racial disparity in African-American prostate cancer [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B069.

Genistein Represses HOTAIR/Chromatin Remodeling Pathways to Suppress Kidney Cancer

BACKGROUND/AIMS

Genistein, a soy isoflavone, has been shown to have anti-cancer effects in various cancers including renal cancer. Long non-coding RNA, HOX transcript antisense RNA (HOTAIR), is involved in cancer progression and metastasis, such as renal cancer. Our aim was to investigate the effects of genistein on HOTAIR chromatin remodeling functions.

METHODS

We used MTS assays and Transwell migration assays to study the effects of genistein on cell proliferation and migration respectively in human renal cell carcinoma (RCC) cell lines. We used Western blots to analyze SNAIL and ZO-1 expression. We performed chromatin immunoprecipitation (ChIP) assays to study recruitment of the polycomb repressive complex 2 (PRC2) to the ZO-1 promoter. We performed RNA immunoprecipitation (RIP) assays to study interaction between HOTAIR and PRC2, SMARCB1 or ARID1A. We also performed transfection experiments to overexpress EED, HOTAIR and knockdown SMARCB1.

RESULTS

Genistein reduced cell proliferation and migration of human renal cell carcinoma cell lines. ChIP assays indicated that genistein reduces recruitment of the PRC2 to the ZO-1 promoter and increased its expression. RIP assays showed that genistein inhibits HOTAIR interaction with PRC2, leading to tumor suppression. Immunoprecipitation also revealed that genistein reduced EED levels in PRC2, suggesting that decreased EED levels suppress HOTAIR interaction with PRC2. EED overexpression in the presence of genistein restored PRC2 interaction with HOTAIR and reduced ZO-1 transcription, suggesting genistein activates ZO-1 by inhibiting HOTAIR/PRC2 functions. RIP assays also showed that HOTAIR interacts with SMARCB1 and ARID1A, subunits of the human SWI/SNF chromatin remodeling complex and genistein reduces this interaction. Combination of HOTAIR overexpression and SMARCB1 knockdown in the presence of genistein revealed that genistein inhibits SNAIL transcription via the HOTAIR/SMARCB1 pathway.

CONCLUSION

Genistein suppresses EED levels in PRC2 and inhibits HOTAIR/PRC2 interaction. Genistein suppresses HOTAIR/PRC2 recruitment to the ZO-1 promoter and enhances ZO-1 transcription. Genistein also inhibits SNAIL transcription via reducing HOTAIR/SMARCB1 interaction. We demonstrate that the reduction of HOTAIR interaction with chromatin remodeling factors by genistein represses HOTAIR/chromatin remodeling pathways to suppress RCC malignancy.

Upregulation of miR-130b Contributes to Risk of Poor Prognosis and Racial Disparity in African-American Prostate Cancer

Prostate cancer incidence and mortality rates are higher in African-American (AA) than in European-American (EA) men. The main objective of this study was to elucidate the role of miR-130b as a contributor to prostate cancer health disparity in AA patients. We also determined whether miR-130b is a prognostic biomarker and a new therapeutic candidate for AA prostate cancer. A comprehensive approach of using cell lines, tissue samples, and the TCGA database was employed. We performed a series of functional assays such as cell proliferation, migration, invasion, RT2-PCR array, qRT-PCR, cell cycle, luciferase reporter, immunoblot, and IHC. Various statistical approaches such as Kaplan-Meier, uni-, and multivariate analyses were utilized to determine the clinical significance of miR-130b. Our results showed that elevated levels of miR-130b correlated with race disparity and PSA levels/failure and acted as an independent prognostic biomarker for AA patients. Two tumor suppressor genes, CDKN1B and FHIT, were validated as direct functional targets of miR-130b. We also found race-specific cell-cycle pathway activation in AA patients with prostate cancer. Functionally, miR-130b inhibition reduced cell proliferation, colony formation, migration/invasion, and induced cell-cycle arrest. Inhibition of miR-130b modulated critical prostate cancer-related biological pathways in AA compared with EA prostate cancer patients. In conclusion, attenuation of miR-130b expression has tumor suppressor effects in AA prostate cancer. miR-130b is a significant contributor to prostate cancer racial disparity as its overexpression is a risk factor for poor prognosis in AA patients with prostate cancer. Thus, regulation of miR-130b may provide a novel therapeutic approach for the management of prostate cancer in AA patients.

Abstract 4659: Cadmium induced malignant transformation involves activation of the Erk/MAPK pathway

Cadmium (Cd) is a chemical pollutant of the natural and occupational environment and is reported to be associated with human carcinogenesis. The molecular mechanisms associated with Cd-induced prostate cancer remain elusive. This study provides evidence that Erk/MAPK signaling is a carcinogenic molecular fingerprint for Cd induced prostate cancer. Cd exposed RWPE1 (Cd-RWPE1) cells robustly formed tumors in nude mice. Functionally, chronic Cd exposure of RWPE1 cells promoted cell survival, proliferation and colony formation with inhibition of apoptosis. RT2 PCR array analysis of 84 genes involved in the Erk/MAPK pathway revealed induction of gene expression in Cd-RWPE1 cells compared to RWPE1. This was confirmed by individual TaqMan gene expression analysis. Gene Set Enrichment Analysis (GSEA) for differentially expressed genes in Cd-RWPE1 showed an enrichment of the Erk/MAPK pathway along with other pathways such as KEGG-ERBB, KEGG-Cell Cycle, KEGG-VEGF, KEGG-Pathways in cancer and KEGG-prostate cancer pathway. We randomly selected upregulated genes from the Erk/MAPK pathway and performed profile analysis in a prostate adenocarcinoma data set (n=534) from the TCGA/GDC data base. We observed upregulation of these genes in prostate cancer compared to normal prostate samples. Taken together, these data reveal that Erk/MAPK signaling is a major pathway involved in Cd-induced malignant transformation of normal prostate epithelial cells. Understanding the dominant oncogenic pathways involved in the malignant transformation of normal prostate epithelial cells may help develop optimal therapeutic strategies for prostate cancer.

Citation Format: Pritha Dasgupta, Priyanka Kulkarni, Nadeem S. Bhat, Ravi Gupta, Yutaka Hashimoto, Sharanjot Saini, Altaf A. Dar, Varahram Shahryari, Soichiro Yamamura, Yuichiro Tanaka, Marisa Shiina, Rajvir Dahiya, Shahana Majid. Cadmium induced malignant transformation involves activation of the Erk/MAPK pathway [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 4659.

Abstract 1827: LncRNA TCL6 / microRNA155 axis regulates the PI3K/ AKT pathway in clear cell renal carcinoma

Background: Kidney cancer is among the 10 most common cancers in both men and women, with clear cell carcinoma (ccRCC) being the most common histologic subtype. It has become increasingly apparent that non-coding RNAs are involved in the regulation of a wide variety of diseases. However, the functional role of non-coding RNAs, such as long noncoding RNA (lncRNAs) and microRNAs (miRNA) in the initiation and progression of kidney tumorigenesis is unclear. Here we show an oncogenic role for miR-155-5p in ccRCC and its novel regulation of RCC through LncRNA TCL6.

Methods: Profiling of TCL6 and miR-155-5p was performed in microdissected renal cancer tissues, matched adjacent normal regions and in human renal cancer cell lines by quantitative real-time PCR. To assess the functional significance of miR-155-5p in RCC, we generated stable miR-155-5p knockdown RCC cells (786-O, Caki-1) and performed functional assays. We also examined the therapeutic potential of miR-155-5p in vivo using a renal cancer xenograft mouse model injected with these stable cells. We performed qPCR and Western analysis to confirm the interaction between miR-155-5p and its targets (TCL6, PIK3R1, FOXO3a, RhoA).

Results: Expression analyses in a cohort of renal cancer clinical specimens showed that LncRNA TCL6 is frequently downregulated and miR-155-5p expression is upregulated in ccRCC. We observed that knockdown of miR-155-5p inhibited cell proliferation, colony formation, migration, invasion and led to G2/M arrest, supporting its oncogenic role in vitro. In ccRCC cells (786-O and Caki-1), inhibition of miR-155-5p significantly upregulated expression, whereas in normal kidney epithelial cell line HK2 over-expression of miR-155-5p decreased levels of its target genes. Over-expression of miR-155-5p in HK2 cells induced cell proliferation, colony formation and enhanced its tumorogenic properties. Furthermore, we found that miR-155-5p may play an important role in the genesis of ccRCC through the PI3K/AKT pathway. In vivo studies demonstrated that the tumor volumes for the mice injected with stable miR-155-5p knockdown cells were significantly less as compared to the mice injected with control parental cells.

Conclusions: Collectively, these data suggest that miR-155-5p plays an oncogenic role in ccRCC. These findings offer new insight into role of lncRNA TCL6/miR-155 axis as a key regulator of the PI3K/AKT pathway in the progression of ccRCC. Thus, inhibition of miR-155 may be an effective therapeutic strategy for treating RCC.

Citation Format: Priyanka Kulkarni, Pritha Dasgupta, Shahana Majid, Marisa Shiina, Yutaka Hashimoto, Varahram Shahryari, Sharanjot Saini, Soichiro Yamamura, Laura Tabatabai, Guoren Deng, Yuichiro Tanaka, Rajvir Dahiya. LncRNA TCL6 / microRNA155 axis regulates the PI3K/ AKT pathway in clear cell renal 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 1827.

Abstract 761: Up-regulation of miR-10a affect on prostate cancer racial disparity

Purpose: Prostate cancer (PC) is the second most diagnosed cancer in men. African-American (AfA) men have higher incidence and twice the PC mortality rates compared to Caucasian-American (CaA) men. In this study, we investigated the biochemical role of miR-10a in prostate cancer racial disparity. Methods: We used PCa cell lines from CaA (DU145, LNCaP, PC3), AfA (MDA-PCa-2b, E006AA-hT) and a normal epithelial cell line (PWR1E) to examine miR-10a expression levels. Total RNA was extracted from total 138 human prostate cancer clinical samples (AfA: n=75, CaA: n=63) and cell lines. Gene expression levels were determined by quantitative real-time PCR (qPCR). A miRNA target database (miRWalk that integrates mainly three databases, miRDB, TargetScan and miRTarBase) was used for miR-10a target prediction. Cell proliferation and apoptosis were monitored after miR-10a knockdown by using anti-miR-10a. Results: miR-10a was significantly up-regulated in AfA prostate cancer cell line, E006AA-hT compared to CaA cells. Utilizing SFVAMC and NDRI patient cohorts, we confirmed that miR-10a expression was linked to a racial difference between AfA/CaA PCa patients. Knockdown of miR-10a showed decreased growth and apoptosis, though the effect was less in CaA compared to AfA cells. We found NCOR2 which is frequently deleted in castration- resistant prostate cancer patient specimens and tumor-suppressor PTEN as miR-10a targets that overlapped in multiple miRNA target prediction databases. Conclusion: These results demonstrate that miR-10a may be a central regulator of crucial events that contribute to racial differences in prostate cancer. Regulation of miR-10a expression may be a new therapeutic strategy for AfA prostate cancer patients.

Citation Format: Yutaka Hashimoto, Marisa Shiina, Yuichiro Tanaka, Pritha Dasgupta, Priyanka Kulkarni, Taku Kato, Ryan K. Wong, Varahram Shahryari, Shigekatsu Maekawa, Soichiro Yamamura, Divya Bhagiratha, Sharanjot Saini, Guoren Deng, Laura Tabatabai, Shahana Majid, Rajvir Dahiya, Rajvir Dahiya. Up-regulation of miR-10a affect on prostate cancer racial disparity [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 761.

Abstract 780: High expression of miR-155 promotes prostate cancer aggressiveness in African-Americans compared to Caucasians

Background: African-Americans have higher risk for developing prostate cancer and when diagnosed, the cancer is more aggressive and African-Americans are more than twice as likely to die of the disease compared to Caucasians. To clarify the mechanisms involved in this disparity, we analyzed the role of miR-155 in African-American and Caucasian prostate cancer tissues and cell lines.

Materials and Methods: Human tissue samples from African-Americans and Caucasians clinical FFPE (Formaldehyde Fixed Paraffin Embedded) were used to analyzed miR-155 expression by Real Time PCR. We selected prostate cancer cell lines from Caucasians (DU-145, LNCaP, PC3), African-American (E006AA-hT) and normal epithelial cell line (PWR-1E) which express different levels of miR-155, to mimic the tissue samples and help identify the mechanisms related to racial disparity. We knocked down miR-155 in cells lines and performed cell viability assays using a CellTiter-Glo luminescent assay. For migration analysis, miR-155 knockdown cells were seeded in chambers and we measured the capacity of cell motility towards a chemo-attractant. To identify miR-155 mediated downstream regulators, three target prediction algorithms (miRDB, Targetscan and miRecords) were used.

Results: We found miR-155 expression to be higher in African-American prostate cancer tissues compared to Caucasian patients with localized disease. Also, expression of miR-155 in African-American cell line, E006AA-hT, was significantly higher compared to Caucasian cell lines, DU-145, LNCaP and PC3. To determine the role of miR-155 in the differences between African-Americans and Caucasians, miR-155 was knocked down in E006AA-hT and DU-145 cells. miR-155 knockdown in E006AA-hT cells caused a decrease in cell viability compared with negative control, while there was no difference in DU-145 cells. We observed inhibition of migration E006AA-hT miR-155 knockdown cells but not on DU-145 miR-155 knockdown cells, suggesting that miR-155 knockdown have the more potent effect on African-American cell line. We analyzed three target prediction

algorithms and found that four genes overlapped, SPI1, JARID2, ETS1 and CEBPB that may play a pivotal role in the treatment of aggressive African-American prostate cancers.

Conclusion: We conclude that high levels of miR-155 is associated with prostate cancer aggressiveness in African-Americans.

Citation Format: Marisa Shiina, Yutaka Hashimoto, Priyanka Kulkarni, Pritha Dasgupta, Varahram Shahryari, Guoren Deng, Divya Bhagirath, Laura Tabatabai, Sharanjot Saini, Shahana Majid, Soichiro Yamamura, Yuichiro Tanaka, Rajvir Dahiya. High expression of miR-155 promotes prostate cancer aggressiveness in African-Americans compared to Caucasians [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 780.

Abstract 3549: Elevated miR-141-3p inhibits renal cell carcinoma aggressiveness by targeting epithelial-to-mesenchymal transition pathway

Objective: Clear cell renal cell carcinoma (ccRCC), a common histological subtype of renal cell carcinoma (RCC) are categorized by their aggressive nature and comprise 90% of metastatic RCCs. Despite recent advances, management of the disease in the advanced metastatic phase is a significant challenge. Expression of miR-141-3p (miR-141) is low and function as tumor suppressor in various cancers. However, its association with long non-coding RNAs (lncRNAs) in RCC is not well understood. This study shows that miR-141 interacts with lncRNAs, and plays vital role in the regulation of stemness and epithelial-to-mesenchymal transition (EMT) in RCC.

Experimental Design: Human renal cancer cell lines (ACHN and Caki-1), normal renal epithelial cells, RPTEC and tumor tissues were used for this study. We analyzed the expression of miR-141 in tissue samples and cell lines, and studied the function of miR-141 in kidney cancer progression using in vitro and in vivo models. Statistical analysis was performed to determine the clinical significance of miR-141 in kidney cancer patients.

Results: Reduced expression of miR-141 was observed in ccRCC clinical specimens and cell lines. To elucidate the epigenetic role of miR-141 silencing in RCC, methylation status of CpG islands in its putative promoter region was analyzed. Result showed significant increase in miR-141 expression after 5-Aza-CdR treatment indicating that promoter hypermethylation is responsible for its inactivation. Ectopic expression of miR-141 reduced cell proliferation, clonogenicity, migration, invasion and induced apoptosis and cell cycle arrest compared to controls. An increase in cleaved PARP, cleaved caspase-3 and epithelial marker (CLDN1) was observed with a concomitant decrease in stemness (KLF4, Nanog) and EMT markers (FN1, VIM). We further investigated the biological significance of miR-141 in RCC. Loss of miR-141 function in RPTEC cells induced pro-cancerous characteristics. In addition, we examined lncRNAs (CDKN2B-As1, PCAT1 and PVT1) that bind to miR-141 and are overexpressed in RCC clinical samples compared to controls. Reduced expression of these lncRNAs was observed in RCC cells with overexpression of miR-141, supporting the notion that miR-141 interacts with these lncRNAs in RCC. Finally, in vivo experiment in nude mice revealed that intra-tumoral administration of miR-141 in the established tumors significantly suppressed tumor growth compared to controls. Furthermore, statistical analysis of patient samples showed that miR-141 may serve as a RCC diagnostic biomarker.

Conclusion: Our results demonstrate that miR-141 overexpression inhibits RCC progression and inhibits epithelial-to-mesenchymal transition. These studies also show that miR-141 may be a useful RCC biomarker for early detection and monitoring RCC progression.

Citation Format: Pritha Dasgupta, Priyanka Kulkarni, Shahana Majid, Varahram Shahryari, Nadeem S. Bhat, Yutaka Hashimoto, Marisa Shiina, Guoren Deng, Sharanjot Saini, Soichiro Yamamura, Yuichiro Tanaka, Rajvir Dahiya. Elevated miR-141-3p inhibits renal cell carcinoma aggressiveness by targeting epithelial-to-mesenchymal transition pathway [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 3549.

Abstract 5040: Involvement of PI3K/Akt pathway in cadmium triggered aggressive prostate cancer

Cadmium (Cd) has been implicated in cancer development and classified as a type I carcinogen by the International Agency for Cancer Research. The etiology of prostate cancer development is associated with multitude of causative risk factors including exposure to cadmium. However, the molecular mechanisms associated with Cd-induced prostate cancer remain elusive. This study provides evidence that PI3K/Akt signaling is a major molecular pathway involved in Cd induced malignant transformation of normal prostate epithelial cells. Functionally, Cd exposure induced aggressive behavior as indicated by increased proliferation, migration and invasion in Cd-RWPE1 cells compared to parental RWPE1. PI3K/Akt pathway is constitutively activated in prostate cancer driving the most aggressive forms of cancer and metastasis. Consistent with these findings, the RT2 PCR array analysis of 84 genes involved in the PI3K/Akt pathway revealed induction of gene expression in catalytic units (P110α, Akt, mTOR, NFKB1, RAF etc.) with a concomitant reduction in expression of regulatory units (PIK3R1, PIK3R2, PTEN etc.) of the PI3K/Akt pathway in Cd-RWPE1 cells compared to parental RWPE1. This was confirmed by individual quantitative real-time PCR analysis using TaqMan gene expression assay probes. Effect of Cd on the translation of the PI3K/Akt pathway genes was examined by immunoblot assays. Gene Set Enrichment Analysis (GSEA) for differentially expressed genes in Cd-RWPE1 showed 5 overlapping pathways that were enriched in Cd-treated cells (Cd-RWPE1) and negatively correlated with parental RWPE1. The overlapping pathways include KEGG Apoptosis pathway (ES=0.56, NES=1), KEGG ERBB pathway (ES=0.25, NES=1), KEGG MAPK pathway (ES=0.48, NES=1), KEGG Pathways in cancer (ES=0.33, NES=1) and KEGG Prostate Cancer pathway (ES=0.35, NES=1). Interestingly, all these pathways are implicated in prostate cancer progression and metastasis. We randomly selected up- and down-regulated genes from the PI3K/Akt pathway in PCR array and performed profile analysis in a prostate adenocarcinoma data set (n=534) from the TCGA/GDC data base. We observed upregulation of the oncogenes along with downregulation of tumor suppressors in prostate cancer compared to normal prostate samples. Taken together, these data reveal that Cd exposure induced aggressive malignant characteristics in normal prostate epithelial cells via modulation of the PI3K/Akt signaling pathway. Understanding the molecular mechanisms involved in the malignant transformation of normal prostate epithelial cells may help develop optimal therapeutic strategies for advanced prostate cancer.

Citation Format: Priyanka Kulkarni, Pritha Dasgupta, Nadeem S. Bhat, Yutaka Hashimoto, Sharanjot Saini, Altaf A. Dar, Varahram Shahryari, Marisa Shiina, Soichiro Yamamura, Yuichiro Tanaka, Rajvir Dahiya, Shahana Majid. Involvement of PI3K/Akt pathway in cadmium triggered aggressive prostate 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 5040.

Elevated miR-182-5p Associates with Renal Cancer Cell Mitotic Arrest through Diminished MALAT-1 Expression

The molecular heterogeneity of clear cell renal carcinoma (ccRCC) makes prediction of disease progression and therapeutic response difficult. Thus, this report investigates the functional significance, mechanisms of action, and clinical utility of miR-182-5p and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1/NEAT2), a long noncoding RNA (lncRNA), in the regulation of kidney cancer using human kidney cancer tissues as well as in vitro and in vivo model systems. Profiling of miR-182-5p and MALAT-1 in human renal cancer cells and clinical specimens was done by quantitative real-time PCR (qPCR). The biological significance was determined by series of in vitro and in vivo experiments. The interaction between miR-182-5p and MALAT-1 was investigated using luciferase reporter assays. In addition, the effects of miR-182-5p overexpression and MALAT-1 downregulation on cell-cycle progression were assessed in ccRCC cells. The data indicate that miR-182-5p is downregulated in ccRCC; the mechanism being CpG hypermethylation as observed from 5-Aza CdR treatment that decreased promoter methylation and expression of key methylation regulatory genes like DNMT1, DNMT3a, and DNMT3b Overexpression of miR-182-5p-inhibited cell proliferation, colony formation, apoptosis, and led to G₂-M-phase cell-cycle arrest by directly targeting MALAT-1 Downregulation of MALAT-1 led to upregulation of p53, downregulation of CDC20, AURKA, drivers of the cell-cycle mitotic phase. Transient knockdown of MALAT-1 mimicked the effects of miR-182-5p overexpression. Finally, overexpression of miR-182-5p decreased tumor growth in mice, compared with controls; thus, demonstrating its antitumor effect in vivo Implications: This is the first study that offers new insight into role of miR-182-5p/MALAT-1 interaction on inhibition of ccRCC progression. Mol Cancer Res; 16(11); 1750-60. ©2018 AACR.

Abstract 4292: Negative regulation of oncogenes by a novel tumor suppressor microRNA in prostate cancer

Background: MicroRNAs are small noncoding RNAs that regulate the expression of >60% of all human genes, either inhibiting target mRNA translation or inducing its degradation. MicroRNAs act as tumor suppressors or oncogenes in various cancers. The main objective of this study was to investigate the role of microRNA-588 (miR-588) in prostate cancer (PC).

Methods: The methods employed in this study include quantitative-real time PCR; western blot; fluorescence-activated cell sorting assays for cell cycle distribution and apoptosis; assays for cell viability, migration and invasiveness of prostate cancer cells. Luciferase reporter assays and in-vivo study in nude mice was also performed.

Results: The expression of miR-588 was significantly suppressed or silenced in PC tissue samples and cell lines when compared with normal tissues and a non-malignant cell line. Similar results were observed by analyzing the publicly available TCGA data sets for prostate adenocarcinoma. Functionally ectopic expression of miR-588 induced G0/G1 cell cycle arrest and apoptosis and suppressed cell proliferation. miR-588 exerted these functional effects by directly targeting the oncogenic Cyclin A2 that is involved in cancer cell cycle and proliferation. In silico algorithm showed a complimentary binding sequence in the 3'UTR of Cyclin A2 for miR-588. Over-expression of miR-588 significantly suppressed the luciferase activity of reporter plasmid containing the wild type 3'UTR sequences of cyclin A2 complementary to miR-588, which was abolished by mutations in these 3'UTR regions. miR-588 overexpression also significantly reduced the expression of cyclin A2 at both mRNA and protein levels. A significant decrease in the expression of various cell cycle pathway genes such as CycE1, MCM2, MCM4, CDC7 and CDT1 was also observed. These genes are involved in promoting cell cycle and proliferation and are overexpressed in prostate cancer. In vivo intracardiac implantation of PC3-MLuc-C6 prostate cancer cells constitutively expressing miR-588 showed a significant inhibition of the metastatic dissemination of these cells compared to the control miR expressing cells.

Conclusion: This is the first study demonstrating that miR-588 is significantly silenced and acts as a tumor suppressor in prostate cancer. Reconstitution of silenced miR-588 may contribute to novel therapeutic approaches for regulating prostate cancer.

Citation Format: Nadeem Bhat, Altaf A. Dar, Sharanjot Saini, Varahram Shahryari, Priyanka Kulkarni, Pritha Dasgupta, Soichiro Yamamura, Yuichiro Tanaka, Taku Kato, Yutaka Hashimoto, Marisa Shiina, Z. Laura Tabatabai, Guoren Deng, Rajvir Dahiya, Shahana Majid. Negative regulation of oncogenes by a novel tumor suppressor microRNA in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4292.

Abstract 1404: Role of catechol-O-methyltransferase gene in prostate cancer

Prostate cancer is one of the most common malignancies and ranks the second most common cause of cancer-related deaths in men in the United States. Catechol-O-methyltransferase (COMT) is a phase II enzyme that detoxifies various catechol compounds that are reactive toward DNA and damaging to the cell. Studies have shown COMT to play a protective role against cancers such as renal and breast, but their effect on prostate is not well understood. In this study, the biological properties and function of COMT in prostate cancer were studied. Expression of COMT was initially measured in normal/benign and cancerous prostate tissues by immunohistochemistry, and cell lines by real-time PCR and western blotting. Cancerous cells displaying the lowest levels was then transfected with COMT. Gene effect on various cellular properties such as cell proliferation, migration, invasion and apoptosis, as well as growth in athymic nude mice were determined. COMT protein expression was lower in cancer regions compared to benign and normal regions of prostate tissues. Cancerous DU145 and DuPro cells also had reduced mRNA levels of COMT but with undetectable protein levels. Interestingly, re-expressing COMT in DU145 and DuPro cells led to decreased cell proliferation, migration, wound healing ability and invasion, and increased apoptosis compared to vector control. COMT also inhibited cell tumor formation in animal models. As a possible target, the TNFRSF11B gene was upregulated due to COMT. These results demonstrate COMT to protect against prostate cancer progression and to have a functional role by affecting apoptosis. COMT may thus be a potential biomarker or therapeutic target for prostate cancer.

Citation Format: Shigekatsu Maekawa, Taku Kato, Yutaka Hashimoto, Marisa Shiina, Ryan K. Wong, Varahram Shahryari, Soichiro Yamamura, Sahana Majid, Sharanjot Saini, Laura Z. Tabatabai, Yukio Homma, Rajvir Dahiya, Yuichiro Tanaka. Role of catechol-O-methyltransferase gene in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1404.

Abstract 2457: Epithelial-to-mesenchymal transition and stemness: Key targets of HOTAIR-miR-203 interaction in renal cell carcinoma

Background: Tumor metastasis and recurrence are major obstacles in renal cell carcinoma (RCC) treatment. RCC aggressiveness is highly associated with stemness and epithelial-to-mesenchymal transition (EMT) which involves increased cellular migration, invasion, inhibition of apoptosis and senescence. HOX transcript antisense RNA (HOTAIR), a lncRNA, is reported to be over-expressed, whereas miR-203 has low expression and is a tumor suppressor in various cancers. However, their association and role in RCC is not well understood. The aim of the present study was to examine the interaction of HOTAIR and miR-203 in the regulation of stemness and EMT in RCC.

Experimental Procedure: ACHN, Caki-1 (human RCC cell lines), normal renal epithelial cells HK-2 and clinical specimens were used for this study. Profiling of HOTAIR and miR203 expression were done by quantitative real-time PCR and luciferase assay was performed to confirm their interaction. Attenuation of HOTAIR (25nM siRNA) and overexpression of miR-203 (10nM mimic) for 72 hours were used for functional studies. The biological role of miR-203 and its interaction with HOTAIR was also investigated using nude mouse models.

Results: HOTAIR was observed to be overexpressed in RCC cell-lines and clinical specimens whereas, miR-203 was significantly under-expressed when compared to normal cells and tissues. Overexpression of miR-203 altered the cell cycle, inhibited epithelial-to-mesenchymal transition (EMT) and decreased cell proliferation along with induction of epithelial marker proteins and decrease in mesenchymal and stemness marker proteins. Conversely, knockdown of miR-203 in non-malignant HK-2 cells induced pro-cancerous characteristics. Direct binding of miR-203 to HOTAIR was shown by RNA immunoprecipitation and luciferase assay. Attenuation of HOTAIR expression reduced cell migration, invasion, and induced apoptosis, mimicking the effects of miR-203 overexpression. Administration of miR-203 mimic to established tumors in nude mice significantly suppressed tumor growth compared to controls.

Conclusion: Our results show that HOTAIR-miR-203 interaction inhibits EMT and stemness to regulate RCC progression. Statistical analysis of the clinicopathological data from kidney cancer patients suggests that HOTAIR and miR-203 may be useful in RCC diagnostics and therapeutics.

Citation Format: Pritha Dasgupta, Priyanka Kulkarni, Shahana Majid, Varahram Shahryari, Yutaka Hashimoto, Nadeem S. Bhat, Marisa Shiina, Guoren Deng, Sharanjot Saini, Soichiro Yamamura Yamamura, Yuichiro Tanaka, Rajvir Dahiya. Epithelial-to-mesenchymal transition and stemness: Key targets of HOTAIR-miR-203 interaction in renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2457.

Abstract 2478: miR-182-5p suppresses progression of renal cancer through cell cycle arrest by targeting lncRNA MALAT-1

Background: Renal cell carcinoma (RCC) is a leading cause of death, accounting for nearly 14,000 (~2.4%) deaths in the United States in 2017, with clear cell carcinoma (ccRCC) being the most common histologic subtype. New and precise disease progression biomarkers are needed for early detection and follow-up. Characterization of these new biomarkers offers a new approach for the identification of novel therapeutic targets and drugs for RCC treatment. MicroRNAs (miRNAs) act as either onco-miRs or tumor suppressors in cancer. Here we show a tumor-suppressor role for miR-182-5p in ccRCC and novel regulation of cell proliferation through MALAT-1.

Methods: Profiling of miR-182-5p and MALAT-1 was performed in microdissected renal cancer tissues, matched adjacent normal regions and in human renal cancer cell lines by quantitative real-time PCR. To assess the functional significance of miR-182-5p in RCC, we overexpressed miR-182-5p/control miRNA (miR-CON) in RCC cell lines (ACHN, Caki-1) followed by functional assays. We also examined the therapeutic potential of synthetic miR-182-5p mimics in vivo using a renal cancer xenograft mouse model. We performed luciferase reporter assay and Ago2-RIP assay to investigate the interaction between miR-182-5p and MALAT-1. In addition, we assessed the effects of miR-182-5p overexpression and MALAT-1 downregulation on cell cycle progression in ccRCC cell lines.

Results: Expression analyses in a cohort of renal cancer clinical specimens showed that miR-182-5p expression is frequently downregulated in ccRCC. We observed that overexpression of miR-182-5p inhibited cell proliferation, colony formation, apoptosis and led to G2/M arrest, supporting an antiproliferative role for this microRNA. Overexpression of miR-182-5p led to decreased expression of CDC20 and AURKA, drivers of the cell cycle mitotic phase. Also, overexpression of miR-182-5p directly lowered the expression of MALAT-1 and knockdown of MALAT-1 mimicked the effects of miR-182-5p overexpression. Downregulation of MALAT-1 led to upregulation of p53 that ultimately downregulated CDC20, AURKA. In vivo studies demonstrated that administration of miR-182-5p caused regression of established renal tumor xenografts.

Conclusions: Collectively, these data suggest that miR-182-5p plays a tumor-suppressive role in ccRCC. These findings offer new insight into role of miR-182-5p in the inhibition of ccRCC tumor growth through MALAT-1 downregulation. This study may provide rationale for development of new strategies targeting MALAT-1 through miR-182-5p for treatment of ccRCC.

Citation Format: Priyanka Kulkarni, Pritha Dasgupta, Shahana Majid, Varahram Shahryari, Marisa Shiina, Yutaka Hashimoto, Nadeem Bhat, Guoren Deng, Sharanjot Saini, Soichiro Yamamura, Yuichiro Tanaka, Rajvir Dahiya. miR-182-5p suppresses progression of renal cancer through cell cycle arrest by targeting lncRNA MALAT-1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2478.

Abstract 1111: Role of a prometastatic miRNA as a negative regulator of the key metastasis suppressor genes in renal cell carcinoma

Background: Renal cell carcinoma (RCC) is among the ten leading cancer types in United States. The 5-year relative survival rate of regional or localized RCC is 65-92%, while that of metastatic RCC is only 12%. Tumor recurrence and metastasis represent two major obstacles in the successful treatment of cancer. Emerging lines of evidence suggest that cancer aggressiveness is associated with epithelial to mesenchymal transition (EMT). Therefore, it is of critical importance to regulate EMT and to develop effective therapeutic strategies for the treatment of recurrent and metastatic cancer. Critical regulators of EMT include transcription repressors and microRNAs that target key proteins involved in EMT. MicroRNAs are implicated in regulating cancer progression and metastasis. Here we show that miR-720 is positively associated with RCC by negatively regulating key metastasis suppressing genes.

Methods: We performed a series of in vitro and in vivo experiments including qRT-PCR, FACS cell cycle and apoptosis, chemotactic transwell migration and invasion, immunoblotting and luciferase reporter assays along with intratumoral xenograft mouse model.

Results: Elevated levels of miR-720 were observed in a panel of RCC cell lines and clinical tissues compared to non-malignant cell line and normal samples. Loss of miR-720 function inhibited proliferation, migration and invasion and induced apoptosis in RCC cell lines in vitro and repressed tumor growth in xenograft mouse model. Conversely, gain of miR-720 function in non-malignant HK-2 cells induced pro-cancerous characteristics. Silencing of miR-720 caused a marked induction in the levels of endogenous αE-catenin and E-cadherin protein levels in anti720 transfected cells compared to control. Whereas, miR-720 overexpression in RCC cell lines reduced activity of a luciferase reporter gene fused to the wild-type αE-catenin or E-cadherin 3' UTR compared to non-specific 3' UTR control indicating that αE-catenin-E-cadherin complex is a direct and functional target of miR-720 in RCC. We also observed attenuation of β-Catenin, CD44 and Akt expression in RCC cells transfected with miR-720 inhibitor compared to control. Further, miR-720 exhibited clinical significance in RCC. Expression of miR-720 significantly distinguished malignant from normal samples. Elevated miR-720 levels positively correlated with higher Fuhrman grade, pathological stage and poor overall survival of RCC patients.

Conclusion: These findings uncover a new regulatory network in RCC involving metastasis-promoting miR-720 that directly targets expression of key metastasis-suppressing proteins E-cadherin and αE-catenin complex. These results suggest that therapeutic regulation of miR-720 may provide an opportunity to regulate EMT and metastasis in RCC.

Citation Format: Nadeem S. Bhat, Altaf A. Dar, Sharanjot Saini, Varahram Shahryari, Soichiro Yamamura, Yuichiro Tanaka, Taku Kato, Yutaka Hashimoto, Marisa Shiina, Priyanka Kulkarni, Pritha Dasgupta, Z Laura Tabatabai, Guoren Deng, Rajvir Dahiya, Shahana Majid. Role of a prometastatic miRNA as a negative regulator of the key metastasis suppressor genes in renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1111.

Abstract 471: High expression of miR-182 promotes prostate cancer aggressiveness in African-Americans compared to Caucasians

Background: African-Americans (AfA) have higher risk for developing prostate cancer and when diagnosed, the cancer is more aggressive with worse survival compared to Caucasians (CA). To clarify the mechanisms involved in this disparity, we analyzed the role of miR-182 in AfA and CA prostate cancer tissues and cells. Materials and Methods: We analyzed miR-182 expression in AfA and CA prostate cancer tissue samples by Real Time PCR. We selected two cell lines, DU-145 (CA) and MDA-PCa-2b (AfA), which express different levels of miR-182, to mimic the tissue samples and help identify the mechanisms related to racial disparity. We generated lentivirus stable miR-182 knockdown cells lines and performed cell viability assays using a CellTiter-Glo luminescent assay. For cell cycle analysis, cells were stained with PI/RNase staining buffer and analyzed for DNA content by BD FACSVerse. Cancer pathway-focused gene expression profiling was done using a human RT2 Profiler Cancer Pathway Finder and Oncogenes and Tumor Suppressor Genes PCR Array. Results: We found miR-182 expression to be higher in AfA prostate cancer tissues compared to CA patients with localized disease. Also, expression of miR-182 in AfA cell line, MDA-PCa-2b, was significantly higher compared to CA cell line, DU-145. To determine the role of miR-182 in the differences between AfA and CA, miR-182 was knocked down in MDA-PCa-2b and DU- 145 cells. miR-182 knockdown in MDA-PCa-2b cells effectively inhibited cell migration, invasion and colony formation compared to control cells, while there was no difference in DU-145 cells. Knockdown of miR-182 caused a decrease in MDA-PCa-2b cell viability compared with negative control. In addition, the cell cycle profile showed an increase in the G1 phase of MDA-PCa-2b cells (control 7.3% compared to miR-182 knockdown cells 18.6%), whereas no change was observed in DU-145 cells. Similar to these results, wound healing was significantly slower in the miR-182 knockdown MDA-PCa-2b cells compared to controls. PCR array analysis was performed to determine the molecular effects of miR-182 knockdown in MDA-PCa-2b and DU-145 cells. We found from our PCR array data some potential targets genes regulated by miR-182. Conclusion: We conclude that high levels of miR-182 is associated with prostate cancer aggressiveness in African-Americans.

Citation Format: Marisa Shiina, Yutaka Hashimoto, Guoren Deng, Varahram Shahryari, Majid Shahana, Soichiro Yamamura, Priyanka Kulkarni, Pritha Dasgupta, Divya Bhagirath, Sharanjot Sharan, Yuichiro Tanaka, Rajvir Dahiya. High expression of miR-182 promotes prostate cancer aggressiveness in African-Americans compared to Caucasians [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 471.

MicroRNA-203 Inhibits Long Noncoding RNA HOTAIR and Regulates Tumorigenesis through Epithelial-to-mesenchymal Transition Pathway in Renal Cell Carcinoma

This study aims to investigate the role of miR-203-HOTAIR interaction in the suppression of renal cell carcinoma (RCC). We employed series of in vitro assays such as proliferation, invasion, migration, and colony formation along with in vivo tumor xenograft model. Profiling of miR-203 and HOTAIR expression revealed that miR-203 was significantly underexpressed, whereas HOTAIR was overexpressed in RCC cell lines and clinical specimens compared with normal cell line and tissue. Both miR-203 and HOTAIR expression significantly distinguished malignant from normal tissues and significantly correlated with clinicopathologic characteristics of patients. Overexpression of miR-203 significantly inhibited proliferation, migration, and invasion with an induction of apoptosis and cell-cycle arrest. However, HOTAIR suppression resulted in the similar functional effects in the same RCC cell lines. In silico, RNA-22 algorithm showed a binding site for miR-203 in HOTAIR. We observed a direct interaction between miR-203 and HOTAIR by RNA-immunoprecipitation (RIP) and luciferase reporter assays. We show that miR-203-HOTAIR interaction resulted in the inhibition of epithelial-to-mesenchymal transition (EMT) and metastatic genes as indicated by induction of key metastasis-suppressing proteins E-cadherin, claudin (epithelial markers), and PTEN along with induction of tumor suppressor genes p21 and p27. A significant decrease in vimentin (mesenchymal marker), KLF4, and Nanog (stemness markers) was also observed. This is the first report demonstrating miR-203-mediated regulation of HOTAIR induces tumor suppressor effects in RCC by regulating EMT and metastatic pathway genes. Thus, the study suggests that therapeutic regulation of HOTAIR by miR-203 overexpression may provide an opportunity to regulate RCC growth and metastasis. Mol Cancer Ther; 17(5); 1061-9. ©2018 AACR.

Functional role and tobacco smoking effects on methylation of CYP1A1 gene in prostate cancer

Cytochrome P450 (CYP) 1A1 is a phase I enzyme that can activate various compounds into reactive forms and thus, may contribute to carcinogenesis. In this study, we investigated the expression, methylation status, and functional role of CYP1A1 on prostate cancer cells. Increased expression of CYP1A1 was observed in all cancer lines (PC-3, LNCaP, and DU145) compared to BPH-1 (P < 0.05); and was enhanced further by 5-aza-2′-deoxycytidine treatment (P < 0.01). Methylation-specific PCR (MSP) and sequencing of bisulfite-modified DNA of the xenobiotic response element (XRE) enhancer site XRE-1383 indicated promoter methylation as a regulator of CYP1A1 expression. In tissue, microarrays showed higher immunostaining of CYP1A1 in prostate cancer than normal and benign prostatic hyperplasia (BPH; P < 0.001), and methylation analyses in clinical specimens revealed significantly lower methylation levels in cancer compared to BPH at all enhancer sites analyzed (XRE-1383, XRE-983, XRE-895; P < 0.01). Interestingly, smoking affected the XRE-1383 site where the methylation level was much lower in cancer tissues from smokers than non-smokers (P < 0.05). CYP1A1 levels are thus increased in prostate cancer and to determine the functional effect of CYP1A1 on cells, we depleted the gene in LNCaP and DU145 by siRNA. We observe that CYP1A1 knockdown decreased cell proliferation (P < 0.05) and increased apoptosis (P < 0.01) in both cell lines. We analyzed genes affected by CYP1A1 silencing and found that apoptosis-related BCL2 was significantly down-regulated. This study supports an oncogenic role for CYP1A1 in prostate cancer via promoter hypomethylation that is influenced by tobacco smoking, indicating CYP1A1 to be a promising target for prostate cancer treatment.

A novel missense mutation affecting the same amino acid as the recurrent PACS1 mutation in Schuurs-Hoeijmakers syndrome

A novel causative variant (c.608G>A, p.Arg203Gln) in PACS1.

Activation of Matrix Hyaluronan-Mediated CD44 Signaling, Epigenetic Regulation and Chemoresistance in Head and Neck Cancer Stem Cells

Head and neck squamous cell carcinoma (HNSCC) is a solid tumor composed by a genotypically and phenotypically heterogeneous population of neoplastic cells types. High recurrence rate and regional metastases lead to major morbidity and mortality. Recently, many studies have focused on cellular and molecular mechanisms of tumor progression that can help to predict prognosis and to choose the best therapeutic approach for HNSCC patients. Hyaluronan (HA), an important glycosaminoglycan component of the extracellular matrix (ECM), and its major cell surface receptor, CD44, have been suggested to be important cellular mediators influencing tumor progression and treatment resistance in head and neck cancer. HNSCC contains a small subpopulation of cells that exhibit a hallmark of CD44-expressing cancer stem cell (CSC) properties with self-renewal, multipotency, and a unique potential for tumor initiation. HA has been shown to stimulate a variety of CSC functions including self-renewal, clone formation and differentiation. This review article will present current evidence for the existence of a unique small population of CD44v3^highALDH^high-expressing CSCs in HNSCC. A special focus will be placed on the role of HA/CD44-induced oncogenic signaling and histone methyltransferase, DOT1L activities in regulating histone modifications (via epigenetic changes) and miRNA activation. Many of these events are essential for the CSC properties such as Nanog/Oct4/Sox2 expression, spheroid/clone formation, self-renewal, tumor cell migration/invasion, survival and chemotherapeutic drug resistance in HA-activated head and neck cancer. These newly-discovered HA/CD44-mediated oncogenic signaling pathways delineate unique tumor dynamics with implications for defining the drivers of HNSCC progression processes. Most importantly, the important knowledge obtained from HA/CD44-regulated CSC signaling and functional activation could provide new information regarding the design of novel drug targets to overcome current therapeutic drug resistance which will have significant treatment implications for head and neck cancer patients.

The role of miR-24 as a race related genetic factor in prostate cancer

The incidence of prostate cancer (PCa) among African-Americans (AfA) is significantly higher than Caucasian-Americans (CaA) but the genetic basis for this disparity is not known. To address this problem, we analyzed miRNA expression in AfA (n = 81) and CaA (n = 51) PCa patients. Here, we found that miR-24 is differentially expressed in AfA and CaA PCa patients and attempt to clarify its role in AfA patients. Also, the public sequencing data of the miR-24 promoter confirmed that it was highly methylated and down-regulated in PCa patients. Utilizing a VAMCSF and NDRI patient cohorts, we discovered that miR-24 expression was linked to a racial difference between AfA/CaA PCa patients. Interestingly, miR-24 was restored after treatment of PCa cells with 5Aza-CdR in an AfA cell line (MDA-PCa-2b), while restoration of miR-24 was not observed in CaA cells, DU-145. Ectopic expression of miR-24 showed decreased growth and induced apoptosis, though the effect was less in the CaA cell line compared to the AfA cell line. Finally, we found unique changes in biological pathways and processes associated with miR-24 transfected AfA cells by quantitative PCR-based gene expression array. Evaluation of the altered pathways showed that AR, IGF1, IGFBP5 and ETV1 were markedly decreased in the AfA derived cell line compared with CaA cells, and there was a reciprocal regulatory relationship of miR-24/target expression in prostate cancer patients. These results demonstrate that miR-24 may be a central regulator of key events that contribute to race-related tumorigenesis and has potential to be a therapeutic agent for PCa treatment.

A case of atypical Kabuki syndrome arising from a novel missense variant in HNRNPK

A novel causative variant (c. 464T>C, p.Leu155Pro) in the heterogeneous nuclear ribonucleoprotein K (HNRNPK) gene.

Abstract 2288: Effects of tobacco smoking and alcohol consumption on risks of CYP1B1 polymorphisms for prostate cancer

Cytochrome P450 1B1 (CYP1B1) converts xenobiotics to carcinogens and polymorphic variants have been shown to increase activity levels. Lifestyle choices such as tobacco smoking and alcohol consumption are known to enhance the carcinogenesis process and in this study, how these factors may interact with CYP1B1 polymorphisms and affect prostate cancer risk was assessed. Blood genomic DNA from a Caucasian population consisting of 405 healthy men and 400 prostate cancer patients were obtained. Of these, 507 were current or former smokers and 407 were alcohol drinkers. Eight polymorphic sites of the promoter region of CYP1B1 (rs2551188 G to A, rs2567206 G to A, rs2567207 A to G, rs162556 A to G, rs10175368 C to T, rs163090 T to A, rs162330 T to G, and rs162331 A to G) were analyzed in samples using Taqman genotyping assays and real-time PCR. Lifestyle factors and its influence on CYP1B1 polymorphisms toward cancer risks were also evaluated. Overall, both alcohol (P=0.006) and smoker (P=0.069) status were associated with prostate cancer. CYP1B1 variants were also risks for cancer at rs2551188 (P=0.043), rs2567206 (P=0.008), and rs10175368 (P=0.001). Evaluation of linkage disequilibrium show rs2551188, rs2567206, rs2567207, and rs10175368 to be linked and interestingly, the G-G-A-C haplotype (wildtype at respective sites) was significantly reduced in cancer (P=0.0282). When classified by lifestyle factors, no associations for CYP1B1 variants were found for cancer among non-smokers with rs10175368 (P=0.051) being a risk among non-drinkers. On the other hand, variants at both rs2567206 and rs10175368 showed increased cancer risk among smokers (P=0.032 and 0.002, respectively) as well as drinkers (P=0.044 and 0.019, respectively). No genotyping differences were observed when analyzing cancers by pathological grades. These results demonstrate smoker and alcoholic drinker status to modify the risks of CYP1B1 polymorphisms for prostate cancer and this is of importance in understanding their role in the pathogenesis of this disease.

Citation Format: Taku Kato, Yutaka Hashimoto, Shigekatsu Maekawa, Marisa Shiina, Mitsuho Imai-Sumida, Pritha Dasgupta, Priyanka Kulkarni, Soichiro Yamamura, Shahana Majid, Sharanjot Saini, Varahram Sharryari, Guoren Deng, Rajvir Dahiya, Yuichiro Tanaka. Effects of tobacco smoking and alcohol consumption on risks of CYP1B1 polymorphisms for prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2288. doi:10.1158/1538-7445.AM2017-2288

Abstract 5448: An exosomal biomarker for prostate cancer

Prostate tumors are highly heterogeneous and molecular characterization based on biopsy sampling is often challenging. Hence, it is desirable to have an easily accessible, minimally invasive way to determine the molecular imprints of a patient’s tumor. Exosomes in blood are an important source of non-invasive, circulating biomarkers and provide an enriched source of microRNAs. With an objective of identifying microRNA based markers, we developed a comprehensive procedure for exosomal microRNA profiling analyses from sera of prostate cancer patients employing Nanostring nCounter technology. In a pilot study, we profiled exosomal miRNAs from a training cohort of normal individuals, patients with benign prostate hyperplasia (BPH), indolent form of PCa and aggressive metastatic prostate cancer. Exosomes were extracted from serum and the integrity of exosomal preparations was confirmed by nanoparticle tracking analysis and Western blot analyses for exosomal markers CD63, CD9 and TSG101. Levels of two miRNAs were significantly upregulated and several candidate miRNAs were markedly downregulated in metastatic PCa serum samples compared with controls. The candidate microRNAs were further validated in a larger cohort by real time PCR based microRNA assays. Of significance, we validated miR-1246 as an exosomal marker for prostate cancer. miR-1246 levels were specifically altered in prostate cancer patients and not significantly altered in BPH. Our analyses suggest that miR-1246 is a promising diagnostic biomarker for prostate cancer.

Citation Format: Divya Bhagirath, Thao Yang, Kirandeep Sekhon, Nathan Bucay, Shahana Majid, Yutaka Hashimoto, Priyanka Kulkarni, Pritha Dasgupta, Marisa Shiina, Varahram Shahryari, Mitsuho Imai-Sumida, Soichiro Yamamura, Z Laura Tabatabai, Yuichiro Tanaka, Rajvir Dahiya, Guoren Deng, Sharanjot Saini. An exosomal biomarker for prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5448. doi:10.1158/1538-7445.AM2017-5448

Abstract LB-326: A novel oncomiR negatively regulates PTEN pathway in prostate cancer

Prostate carcinogenesis involves alterations in several signaling pathways, the most prominent being the PI3K/AKT pathway. This pathway is constitutively active and drives prostate cancer (PCa) progression to advanced metastatic disease. PTEN, a critical tumor and metastasis suppressor gene negatively regulates cell survival, proliferation, migration and angiogenesis via the PI3K/Akt pathway. PTEN is mutated, downregulated/dysfunctional in many cancers and its dysregulation correlates with poor prognosis in PCa. Here, we demonstrate that a novel microRNA, microRNA-4534 (miR-4534) is overexpressed in PCa and show that miR-4534 is hypermethylated in normal tissues and cell lines compared to PCa tissues/cells. miR-4534 exerts its oncogenic effects partly by downregulating the tumor suppressor PTEN gene. Knockdown of miR-4534 impaired cell proliferation, migration/invasion and induced G0/G1 cell cycle arrest and apoptosis in PCa. Suppression of miR-4534 and its effects on tumor growth was confirmed in a xenograft mouse model. We performed parallel experiments in non-cancer RWPE1 cells by overexpessing miR-4534 followed by functional assays. Overexpression of miR-4534 induced pro-cancerous characteristics in this non-cancer cell line. Kaplan-Meier and ROC analyses revealed that miR-4534 has potential to independently distinguish malignant from normal tissues and positively correlated with poor overall and PSA recurrence free survival. Taken together, our results show that depletion of miR-4534 in PCa induces a tumor suppressor phenotype partly through induction of PTEN. These results have important implications for identifying and defining the role of new PTEN regulators such as microRNAs in prostate tumorigenesis. Understanding aberrantly overexpressed miR-4534 and its downregulation of PTEN will provide mechanistic insight and therapeutic targets for PCa therapy.

Note: This abstract was not presented at the meeting.

Citation Format: Nadeem S. Bhat, Melissa Colden, Prerna Arora, Altaf A. Dar, Sharanjot Saini, Varahram Shahryari, Soichiro Yamamura, Yuichiro Tanaka, Taku Katu, Yutaka Hashimoto, Marisa Shiina, Priyanka Kulkarni, Pritha Dasgupta, Mitsuho Imai-sumida, Shigekatsu Maekawa, Guoren Deng, Rajvir Dahiya, Shahana Majid. A novel oncomiR negatively regulates PTEN pathway in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-326. doi:10.1158/1538-7445.AM2017-LB-326

Abstract 462: The role of miR-24 as a race-related genetic factor in prostate cancer

The incidence of prostate cancer (PCa) among African-Americans (AfA) is significantly higher than Caucasian-Americans (CaA) but the genetic basis for this disparity is not known. To address this problem, we analyzed miRNA expression in AfA (n=81) and CaA (n=51) PCa patients. Here, we found that miR-24 is differentially expressed in AfA and CaA PCa patients and attempt to clarify its role in AfA patients. Also, the public sequencing data of the miR-24 promoter confirmed that it was highly methylated and down-regulated in PCa patients. Utilizing a VAMCSF and NDRI patient cohorts, we discovered that miR-24 expression was linked to a racial difference between AfA/CaA PCa patients. Interestingly, miR-24 was restored after treatment of PCa cells with 5Aza-CdR in an AfA cell line (MDA-PCa-2b), while restoration of miR-24 was not observed in CaA cells, DU-145. Ectopic expression of miR-24 showed decreased growth and induced apoptosis, though the effect was less in the CaA cell line compared to the AfA cell line. Finally, we found unique changes in biological pathways and processes associated with miR-24 transfected AfA cells by quantitative PCR-based gene expression array. Evaluation of the altered pathways showed that AR, PDPK1, IGF1, and IGFBP5 were markedly decreased in the AfA derived cell line compared with CaA cells, and there was a reciprocal regulatory relationship of miR-24/target expression in prostate cancer patients. These results demonstrate that miR-24 may be a central regulator of key events that contribute to race-related tumorigenesis and has potential to be a therapeutic agent for PCa treatment.

Citation Format: Yutaka Hashimoto, Marisa Shiina, Taku Kato, Soichiro Yamamura, Yuichiro Tanaka, Shahana Majid, Sharanjot Saini, Varahram Shahryari, Priyanka Kulkarni, Pritha Dasgupta, Yozo Mitsui, Mitsuho Sumida, Guoren Deng, Laura Tabatabai, Deepak Kumar, Rajvir Dahiya. The role of miR-24 as a race-related genetic factor in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 462. doi:10.1158/1538-7445.AM2017-462

Abstract 3449: Genistein inhibits renal cancer progression through long non-coding RNA HOTAIR suppression

Genistein, a soy isoflavone, has been shown to have anticancer effects on various cancers in vitro and in vivo including renal cancer. Long non-coding RNAs (lncRNAs) are differentially expressed in various tissues and have important functions in cellular processes such as cell proliferation, motility and apoptosis in various malignancies. HOX transcript antisense RNA (HOTAIR) is a lncRNA localized in the Homeobox C gene cluster on chromosome 12. HOTAIR interacts with the polycomb repressive complex 2 (PRC2), which enhances H3K27 trimethylation and represses the expression of tumor suppressors. In various cancers, HOTAIR is highly expressed and involved in their progression and metastasis. In this study, we investigated the molecular mechanisms of genistein action through a novel pathway that represses HOTAIR. We found that HOTAIR expression is higher in renal cancer cell lines compared to normal controls. Genistein treatment was found to significantly decrease HOTAIR expression in renal cancer cells (786-O and ACHN cells). Genistein treatment also reduced expression of epithelial-to-mesenchyme transition (EMT)-related proteins (ZEB1, Vimentin and Snail), causing reduced cell migration, invasion, and increased apoptosis. We performed RNA immunoprecipitation assays, and found that genistein inhibits HOTAIR binding to PRC2. One of the other EMT markers, a tight junction protein ZO-1, is upregulated by genistein. We are currently investigating if genistein represses PRC2 recruitment to the ZO-1 promoter by inhibiting binding of HOTAIR to PRC2. Our results indicate that genistein is a potent therapeutic agent for renal cancer.

Citation Format: Mitsuho Imai-Sumida, Shahana Majid, Pritha Dasgupta, Priyanka Kulkarni, Sharanjot Saini, Divya Bhagirath, Taku Kato, Shigekatsu Maekawa, Yutaka Hashimoto, Marisa Shiina, Guoren Deng, Varahram Shahryari, Yuichiro Tanaka, Rajvir Dahiya, Soichiro Yamamura. Genistein inhibits renal cancer progression through long non-coding RNA HOTAIR suppression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3449. doi:10.1158/1538-7445.AM2017-3449

Abstract 5749: VCAN promotes clear cell renal cell carcinoma tumor progression and metastasis, and predicts poor prognosis

Introduction and Objectives: Although versican (VCAN) is known to promote tumor progression and enhance metastasis of several types of cancers, its role in clear cell renal cell carcinoma (ccRCC) remains unknown. Interestingly, a recent report showed that VCAN is an important target of chromosomal 5q gain, one of the most prevalent genetic abnormalities in ccRCC cases. In the present study, we investigated whether VCAN expression is associated with the pathogenesis of ccRCC.

Methods: VCAN expression was analyzed in 3 RCC and normal kidney cell lines, as well as 84 matched ccRCC and normal renal tissues. We also performed various functional analyses of growth and progression properties using VCAN-depleted ccRCC cells. Microarray analysis was then employed to investigate the target genes of the pathway involved in ccRCC tumorigenesis and development.

Results: There are 4 isoforms of VCAN containing the N-terminal globular (G1 domain) and C-terminal globular (G3 domain) domains, each of which was found to be over-expressed in the ccRCC samples as compared to the controls. Higher VCAN expression was significantly correlated with metastasis (p&lt;0.001) and worse 5-year overall survival after a radical nephrectomy (p=0.014). In vitro, VCAN knockdown by siRNA in Caki-2 and 786-O cells significantly decreased cell proliferation and increased apoptosis, and was also found to be associated with alteration of several TNF signaling-related genes, such as TNF-α, BID, and BAK. Furthermore, VCAN depletion markedly decreased cell migration and invasion associated with reduced MMP7 and CXCR4 levels.

Conclusion: Our results demonstrate that VCAN promotes ccRCC tumorigenesis and metastasis, showing it to be an attractive novel target for diagnostic, prognostic, and therapeutic strategies for affected patients.

Note: This abstract was not presented at the meeting.

Citation Format: Yozo Mitsui, Taku Kato, Shigekatsu Maekawa, Yutaka Hashimoto, Marisa Shiina, Mitsuho Imai Sumida, Ryan Kenji Wong, Soichiro Yamamura, Varahram Shahryari, Shahana Majid, Sharanjot Saini, Guoren Deng, Rajvir Dahiya, Koichi Nakajima, Yuichiro Tanaka. VCAN promotes clear cell renal cell carcinoma tumor progression and metastasis, and predicts poor prognosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5749. doi:10.1158/1538-7445.AM2017-5749

Abstract 4435: Exosomal miR-3622a as prognostic marker in prostate cancer

Loss of chromosome (chr) 8p21 is a frequent genomic alteration in prostate cancer (PCa). Genomic deletions of this region increase significantly with tumor grade and are associated with tumor progression and poor prognosis. A common region of loss of heterozygosity (LOH) has been mapped to the chr8p21 locus that primarily harbors prostate-specific NKX3.1 homeobox gene. We recently demonstrated that this frequently deleted locus is associated with a cluster of microRNA genes- miR-3622a/b- that are lost in prostate cancer and play an important mechanistic role in PCa progression and metastasis. MicroRNA expression profiling in microdissected human PCa clinical tissues showed that miR-3622a/b expression is widely downregulated and is correlated with poor survival outcome in prostate cancer. Our analyses suggested that miR-3622a has potential as a prognostic and diagnostic marker for prostate cancer. Extending these findings, we explored the prognostic potential of serum miR-3622a in prostate cancer patients. Since exosomes provide an important source of non-invasive, circulating biomarkers and represent an enriched source of microRNAs for biomarker profiling, we profiled the microRNA content of exosomes derived from sera of prostate cancer patients. In a pilot study, we profiled exosomal miRNAs from a training cohort of individuals with benign prostate hyperplasia (BPH), an indolent form of PCa or aggressive metastatic PCa. Exosomes were isolated from sera of prostate cancer patients and integrity of exosomal preparations was confirmed by nanoparticle tracking analysis and Western blot analyses for exosomal markers. Expression analyses of exosomal miR-3622a expression showed that this miRNA is enriched in exosomes. Higher levels of miR-3622a were significantly associated with tumor stage and lymph node metastasis in a cohort of prostate cancer clinical specimens. Further, ROC (Receiver Operating Characteristic) analyses showed that exosomal miR-3622a expression can be a single significant parameter to discriminate between BPH and prostate cancer. Overall, our data suggests that exosomal miR-3622a is a promising prognostic biomarker for prostate cancer. patients.

Citation Format: Thao Yang, Divya Bhagirath, Kirandeep Sekhon, Nathan Bucay, Shahana Majid, Varahram Shahryari, Marisa Shiina, Yutaka Hashimoto, Priyanka Kulkarni, Pritha Dasgupta, Mitsuho Imai-Sumida, Soichiro Yamamura, Z Laura Tabatabai, Kirsten Greene, Yuichiro Tanaka, Rajvir Dahiya, Guoren Deng, Sharanjot Saini. Exosomal miR-3622a as prognostic marker in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4435. doi:10.1158/1538-7445.AM2017-4435

Abstract 483: Differential expression of miR-34b and androgen receptor pathway regulate prostate cancer aggressiveness between African Americans and Caucasians

African-Americans are diagnosed with more aggressive prostate cancers and have worse survival than Caucasians, however a comprehensive understanding of this health disparity remains unclear. To clarify the mechanisms leading to this disparity, we analyzed the potential involvement of miR-34b expression in African-Americans and Caucasians. We found that miR-34b expression is lower in human prostate cancer tissues from African-Americans compared to Caucasians. DNA hypermethylation of the miR-34b-3p promoter region showed significantly higher methylation in prostate cancer compared to normal tissues. We found that AR and ETV1 genes are differentially expressed in MDA-PCa-2b and DU-145 cells after overexpression of miR-34b. Direct interaction of miR-34b with the 3’ untranslated region of AR and ETV1 was validated by luciferase reporter assay. We found that miR-34b downregulation in African-Americans is inversely correlated with high AR levels that lead to increased cell proliferation. Overexpression of miR-34b in cell lines showed higher inhibition of cell proliferation, apoptosis and G1 arrest in African-American cells (MDA-PCa-2b) compared to the Caucasian cell line (DU-145). Taken together, our results show that differential expression of miR-34b and AR are associated with prostate cancer aggressiveness in African-Americans.

Citation Format: Marisa Shiina, Yutaka Hashimoto, Taku Kato, Soichiro Yamamura, Yuichiro Tanaka, Shahana Majid, Sharanjot Saini, Shahryari Varahram, Priyanka Kulkarni, Prita Dasgupta, Mitsuho Sumida, Guoren Deng, Rajvir Dahiya. Differential expression of miR-34b and androgen receptor pathway regulate prostate cancer aggressiveness between African Americans and Caucasians [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 483. doi:10.1158/1538-7445.AM2017-483

Versican Promotes Tumor Progression, Metastasis and Predicts Poor Prognosis in Renal Carcinoma

The proteoglycan versican (VCAN) promotes tumor progression and enhances metastasis in several cancers; however, its role in clear cell renal cell carcinoma (ccRCC) remains unknown. Recent evidence suggests that VCAN is an important target of chromosomal 5q gain, one of the most prevalent genetic abnormalities in ccRCC. Thus, we investigated whether VCAN expression is associated with the pathogenesis of ccRCC. VCAN expression was analyzed using three RCC and normal kidney cell lines as well as a clinical cohort of 84 matched ccRCC and normal renal tissues. Functional analyses on growth and progression properties were performed using VCAN-depleted ccRCC cells. Microarray expression profiling was employed to investigate the target genes and biologic pathways involved in VCAN-mediated ccRCC carcinogenesis. ccRCC had elevated VCAN expression in comparison with normal kidney in both cell lines and clinical specimens. The elevated expression of VCAN was significantly correlated with metastasis (P < 0.001) and worse 5-year overall survival after radical nephrectomy (P = 0.014). In vitro, VCAN knockdown significantly decreased cell proliferation and increased apoptosis in Caki-2 and 786-O cells, and this was associated with alteration of several TNF signaling-related genes such as TNFα, BID, and BAK Furthermore, VCAN depletion markedly decreased cell migration and invasion which correlated with reduction of MMP7 and CXCR4. These results demonstrate that VCAN promotes ccRCC tumorigenesis and metastasis and thus is an attractive target for novel diagnostic, prognostic, and therapeutic strategies.Implications: This study highlights the oncogenic role of VCAN in renal cell carcinogenesis and suggests that this gene has therapeutic and/or biomarker potential for renal cell cancer. Mol Cancer Res; 15(7); 884-95. ©2017 AACR.

Differential expression of miR-34b and androgen receptor pathway regulate prostate cancer aggressiveness between African-Americans and Caucasians

African-Americans are diagnosed with more aggressive prostate cancers and have worse survival than Caucasians, however a comprehensive understanding of this health disparity remains unclear. To clarify the mechanisms leading to this disparity, we analyzed the potential involvement of miR-34b expression in African-Americans and Caucasians. miR-34b functions as a tumor suppressor and has a multi-functional role, through regulation of cell proliferation, cell cycle and apoptosis. We found that miR-34b expression is lower in human prostate cancer tissues from African-Americans compared to Caucasians. DNA hypermethylation of the miR-34b-3p promoter region showed significantly higher methylation in prostate cancer compared to normal samples. We then sequenced the promoter region of miR-34b-3p and found a chromosomal deletion in miR-34b in African-American prostate cancer cell line (MDA-PCA-2b) and not in Caucasian cell line (DU-145). We found that AR and ETV1 genes are differentially expressed in MDA-PCa-2b and DU-145 cells after overexpression of miR-34b. Direct interaction of miR-34b with the 3' untranslated region of AR and ETV1 was validated by luciferase reporter assay. We found that miR-34b downregulation in African-Americans is inversely correlated with high AR levels that lead to increased cell proliferation. Overexpression of miR-34b in cell lines showed higher inhibition of cell proliferation, apoptosis and G1 arrest in the African-American cells (MDA-PCa-2b) compared to Caucasian cell line (DU-145). Taken together, our results show that differential expression of miR-34b and AR are associated with prostate cancer aggressiveness in African-Americans.

Up-regulation of Histone Methyltransferase, DOT1L, by Matrix Hyaluronan Promotes MicroRNA-10 Expression Leading to Tumor Cell Invasion and Chemoresistance in Cancer Stem Cells from Head and Neck Squamous Cell Carcinoma

Human head and neck squamous cell carcinoma is a solid tumor malignancy associated with major morbidity and mortality. In this study, we determined that human head and neck squamous cell carcinoma-derived HSC-3 cells contain a subpopulation of cancer stem cells (CSCs) characterized by a high level of CD44v3 and aldehyde dehydrogenase-1 (ALDH1) expression. Importantly, matrix hyaluronan (HA) induces the up-regulation of stem cell markers that display the hallmark CSC properties. Histone methyltransferase, DOT1L, is also up-regulated by HA in CSCs (isolated from HSC-3 cells). Further analyses indicate that the stimulation of microRNA-10b (miR-10b) expression is DOT1L-specific and HA/CD44-dependent in CSCs. This process subsequently results in the overexpression of RhoGTPases and survival proteins leading to tumor cell invasion and cisplatin resistance. Treatment of CSCs with DOT1L-specific small interfering RNAs (siRNAs) effectively blocks HA/CD44-mediated expression of DOT1L, miR-10b production, and RhoGTPase/survival protein up-regulation as well as reduces tumor cell invasion and enhances chemosensitivity. CSCs were also transfected with a specific anti-miR-10b inhibitor to silence miR-10b expression and block its target functions. Our results demonstrate that the anti-miR-10 inhibitor not only decreases RhoGTPase/survival protein expression and tumor cell invasion, but also increases chemosensitivity in HA-treated CSCs. Taken together, these findings strongly support the contention that histone methyltransferase, DOT1L-associated epigenetic changes induced by HA play pivotal roles in miR-10 production leading to up-regulation of RhoGTPase and survival proteins. All of these events are critically important for the acquisition of cancer stem cell properties, including self-renewal, tumor cell invasion, and chemotherapy resistance in HA/CD44-activated head and neck cancer.

A PLK4 mutation causing azoospermia in a man with Sertoli cell-only syndrome

About 15% of couples wishing to have children are infertile; approximately half these cases involve a male factor. Polo-like kinase 4 (PLK-4) is a member of the polo protein family and a key regulator of centriole duplication. Male mice with a point mutation in the Plk4 gene show azoospermia associated with germ cell loss. Mutational analysis of 81 patients with azoospermia and Sertoli cell-only syndrome (SCOS) identified one man with a heterozygous 13-bp deletion in the Ser/Thr kinase domain of PLK4. Division of centrioles occurred in wild-type PLK4-transfected cells, but was hampered in PLK-4-mutant transfectants, which also showed abnormal nuclei. Thus, this PLK4 mutation might be a cause of human SCOS and nonobstructive azoospermia.

Hyaluronan-CD44 interaction promotes oncogenic signaling, microRNA functions, chemoresistance, and radiation resistance in cancer stem cells leading to tumor progression

Hyaluronan (HA), a major component of the extracellular matrix (ECM), is enriched in many types of tumors. There is good evidence linking high levels of HA production in human carcinomas to an aggressive phenotype and tumor metastasis. HA is generally bound to CD44 isoforms (so-called CD44s and CD44v3) which are ubiquitous, abundant, and functionally important cell surface receptors. This chapter describes the evidence for HA/CD44v3-mediated activation of the cytoskeleton (e.g., ankyrin and GTPases) and matrix metalloproteinase (MMP) signaling during tumor progression. A special focus is placed on the role of HA-CD44v3 interaction in cancer stem cells (CSCs). Matrix HA is known to be present in CSC niches. Since CD44v3 serves as a CSC marker, it provides an important physical linkage between matrix HA and various transcription factors that regulate tumor cell functions through distinct signaling pathways. CSCs are known to be chemoresistant and/or radiation resistant and to cause cancer relapse. The purpose of this chapter is to review the most current research on the cellular and molecular biology of CSCs. The emphasis will be placed on both CSC niche and matrix HA-induced microRNA signaling plus various CSC functions (e.g., self-renewal, differentiation, and chemoresistance) during cancer progression. Understanding the regulation of CSCs is critically important for designing CSC-specific therapeutic targets to prevent cancer development and progression.

ZEB1 limits adenoviral infectability by transcriptionally repressing the coxsackie virus and adenovirus receptor

Background

We have previously reported that RAS-MEK (Cancer Res. 2003 May 1;63(9):2088-95) and TGF-β (Cancer Res. 2006 Feb 1;66(3):1648-57) signaling negatively regulate coxsackie virus and adenovirus receptor (CAR) cell-surface expression and adenovirus uptake. In the case of TGF-β, down-regulation of CAR occurred in context of epithelial-to-mesenchymal transition (EMT), a process associated with transcriptional repression of E-cadherin by, for instance, the E2 box-binding factors Snail, Slug, SIP1 or ZEB1. While EMT is crucial in embryonic development, it has been proposed to contribute to the formation of invasive and metastatic carcinomas by reducing cell-cell contacts and increasing cell migration.

Results

Here, we show that ZEB1 represses CAR expression in both PANC-1 (pancreatic) and MDA-MB-231 (breast) human cancer cells. We demonstrate that ZEB1 physically associates with at least one of two closely spaced and conserved E2 boxes within the minimal CAR promoter here defined as genomic region -291 to -1 relative to the translational start ATG. In agreement with ZEB1's established role as a negative regulator of the epithelial phenotype, silencing its expression in MDA-MB-231 cells induced a partial Mesenchymal-to-Epithelial Transition (MET) characterized by increased levels of E-cadherin and CAR, and decreased expression of fibronectin. Conversely, knockdown of ZEB1 in PANC-1 cells antagonized both the TGF-β-induced down-regulation of E-cadherin and CAR and the reduction of adenovirus uptake. Interestingly, even though ZEB1 clearly contributes to the TGF-β-induced mesenchymal phenotype of PANC-1 cells, TGF-β did not seem to affect ZEB1's protein levels or subcellular localization. These findings suggest that TGF-β may inhibit CAR expression by regulating factor(s) that cooperate with ZEB1 to repress the CAR promoter, rather than by regulating ZEB1 expression levels. In addition to the negative E2 box-mediated regulation the minimal CAR promoter is positively regulated through conserved ETS and CRE elements.

Conclusions

This report provides evidence that inhibition of ZEB1 may improve adenovirus uptake of cancer cells that have undergone EMT and for which ZEB1 is necessary to maintain the mesenchymal phenotype. Targeting of ZEB1 may reverse some aspects of EMT including the down-regulation of CAR.

Four-year study of lamivudine and adefovir combination therapy in lamivudine-resistant hepatitis B patients: influence of hepatitis B virus genotype and resistance mutation pattern

To investigate the efficacy of long-term lamivudine (3TC) and adefovir dipivoxil (ADV) combination therapy in 3TC-resistant chronic hepatitis B virus (HBV) infected patients, we analysed 28 3TC-resistant patients treated with the combination therapy during 47 months (range, 9-75). At 12, 24, 36, and 48 months, the rates of virological response with undetectable HBV DNA (≤ 2.6 log copies/mL) were 56, 80, 86, and 92%, respectively. Among 17 hepatitis B e antigen (HBeAg)-positive patients, HBeAg disappeared in 24% at 12 months, 25% at 24 months, 62% at 36 months, and 88% at 48 months. When HBV genotypes were compared, patients with genotype B achieved virological response significantly more rapidly than those with genotype C (P=0.0496). One patient developed virological breakthrough after 54 months, and sequence analysis of HBV obtained from the patient was performed. An rtA200V mutation was present in the majority of HBV clones, in addition to the 3TC-resistant mutations of rtL180M+M204V. The rtN236T ADV-resistant mutation was observed in only 25% clones. In vitro analysis showed that the rtA200V mutation recovered the impaired replication capacity of the clone with the rtL180M+M204V mutations and induced resistance to ADV. Moreover, rtT184S and rtS202C, which are known entecavir-resistant mutations, emerged in some rtL180M+M204V clones without rtA200V or rtN236T. In conclusion, 3TC+ADV combination therapy was effective for most 3TC-resistant patients, especially with genotype B HBV, but the risk of emergence of multiple drug-resistant strains with long-term therapy should be considered. The mutation rtA200V with rtL180M+M204V may be sufficient for failure of 3TC+ADV therapy.