Young-Ae Park

Altered MicroRNA Expression in Cervical Carcinomas

Purpose: MicroRNAs (miRNA) are small noncoding RNAs that are 18 to 25 nucleotides in length; they regulate the stability or translational efficiency of target mRNAs. Emerging evidence suggests that miRNAs might be involved in the pathogenesis of a variety of human cancers. Experimental Design: In this study, we profiled miRNA expression in 10 early stage invasive squamous cell carcinomas (ISCC) and 10 normal cervical squamous epithelial specimens using TaqMan real-time quantitative PCR array methods. In order to evaluate the role of miR-199a, one of the most significantly overexpressed in ISCCs, we transfected cervical cancer cells (SiHa and ME-180) with anti–miR-199a oligonucleotides and assessed the cell viability. Results: We found 70 genes (68 up-regulated, 2 down-regulated) with significantly different expression in the ISCCs compared with normal samples (P < 0.05). When we analyzed the expression of the 10 most significant miRNAs in 31 ISCCs, increased miR-127 expression was significantly associated with lymph node metastasis (P = 0.006). Transfection of anti–miR-199a oligonucleotides to cervical cancer cells suppressed cell growth in vitro, which was potentiated with the anticancer agent cisplatin. Conclusions: Our results show that miRNA deregulation may play an important role in the malignant transformation of cervical squamous cells. In addition, they may offer new candidate targets to be exploited for both prognostic and therapeutic strategies in patients with cervical cancer.

The expression of the miRNA-200 family in endometrial endometrioid carcinoma

OBJECTIVEnRecent reports suggest that targeting the unique miRNAs highly expressed in several cancers may be a promising approach in the development of new cancer therapeutic tools. The purpose of this study was to evaluate the roles of miRNAs as therapeutic targets in human endometrial endometrioid carcinomas (EECs).nnnMETHODSnWe evaluated the differential expressions of miRNAs in EECs and normal endometrial tissues using microarrays and cluster analysis. After validation of differentially expressed miRNAs in another set of EECs and normal endometrial tissues, we performed the in vitro experiment using endometrial cancer cells with anti-miRNA (anti-miR) to evaluate the roles of miRNAs that are highly expressed in EECs for cell proliferation and chemosensitivity.nnnRESULTSnA miRNA microarray showed that the miR-200 family, including hsa-miR-141, hsa-miR-200a, hsa-miR-200b, hsa-miR-200c, and hsa-miR-429, was up-regulated in EECs as compared with that in normal endometrial tissues. When we treated endometrial cancer cells with specific anti-miRs, including anti-miR-141, -200a, -200b, -200c, or -429, we found that anti-miR-200a, -200b, -200c, and -429 significantly inhibited the growth of HEC-1A cells and anti-miR-141, -200c, and -429 significantly inhibited the growth of Ishikawa cells. Moreover, transfection with anti-miR-429 enhanced the cytotoxic effect of cisplatin in HEC-1A cells.nnnCONCLUSIONSnThese results indicate that the miR-200 family is highly expressed in EECs compared with that of normal endometrial tissues and could play an important role in cancer growth. Specifically, anti-miR-429 could enhance the cytotoxic activity with cisplatin in EECs. Therefore, the miR-200 family may offer new candidate targets to be exploited in therapeutic strategies for patients with these carcinomas.

Angiotensin II type I receptor and miR-155 in endometrial cancers: Synergistic antiproliferative effects of anti-miR-155 and losartan on endometrial cancer cells ☆

OBJECTIVEnMicroRNA-155 (miR-155) is one of the micro RNAs (miRNA) most consistently involved in neoplastic diseases, and it is known to repress the angiotensin II type 1 receptor (AGTR1). The aim of the present study was to evaluate the expressions of miR-155 and AGTR1, and to clarify the potential efficacy of anti-miR-155, alone and in combination with AGTR1 blocker losartan in endometrial cancers.nnnMETHODSnExpressions of miR-155 and AGTR1 were evaluated using real-time PCR and immunohistochemistry. And the MTT assay was performed in endometrial cancer cells following anti-miR-155 and AGTR1 blocker (losartan) treatment, alone and in combination.nnnRESULTSnmiR-155 was over-expressed and AGTR1 was underexpressed in endometrial carcinoma tissues. AGTR1 immunoreactivity was found in six of ten (60.0%) normal endometrium, 11 of 14 (78.6%) endometrial hyperplasia, and 27 of 62 (43.5%) endometrial carcinoma tissues (P=0.051), and patients with AGTR1 expression showed trend towards improved survival after multivariate analysis (P=0.08). We checked that abolishing the function of miR-155 and AGTR1 by anti-miR-155 or losartan inhibited cell survival of endometrial carcinoma cells, respectively, and furthermore, combined treatment showed synergistic effects.nnnCONCLUSIONSnIn this study, we characterized the expressions of miR-155 and AGTR1 in endometrial tissues. The combined treatment with anti-miR-155 and losartan has a synergistic antiproliferative effect and an improved understanding is required to clarify whether miR-155 and AGTR1 can be used as a novel therapeutic target in endometrial cancer.

Tumor Suppressive Effects of Bromodomain-Containing Protein 7 (BRD7) in Epithelial Ovarian Carcinoma

Purpose: Bromodomain-containing protein 7 (BRD7), which is a subunit of SWI/SNF complex, has been recently suggested as a novel tumor suppressor in several cancers. In this study, we investigated the tumor suppressive effect of BRD7 in epithelial ovarian cancer. Experimental Design: We analyzed the expression of BRD7 in human ovarian tissues with real-time PCR. To investigate the functional role of BRD7, we transfected ovarian cancer cells (A2780 and SKOV3) with BRD7 plasmid and checked the cell viability, apoptosis, and invasion. The activities of BRD7 in the signaling pathways associated with carcinogenesis were also tested. In addition, we used the orthotopic mouse model for ovarian cancer to evaluate tumor growth-inhibiting effect by administration of BRD7 plasmid. Results: The BRD7 expression was downregulated in the ovarian cancer tissues compared with normal (P < 0.05), high-grade serous cancer exhibited significantly decreased expression of BRD7 compared with low-grade (P < 0.01) serous cancer. Transfection of BRD7 plasmid to A2780 (p53-wild) or SKOV3 (p53-null) ovarian cancer cells showed the tumor suppressive effects assessed by cell viability, apoptosis, and invasion assay and especially significantly decreased tumor weight in orthotopic mouse model (A2780). Moreover, we found that tumor suppressive effects of BRD7 are independent to the presence of p53 activity in ovarian cancer cells. BRD7 negatively regulated β-catenin pathway, resulting in decreased its accumulation in the nucleus. Conclusions: These results suggested that BRD7 acts as a tumor suppressor in epithelial ovarian cancers independently of p53 activity, via negative regulation of β-catenin pathway. Clin Cancer Res; 20(3); 565–75. ©2013 AACR.

High claudin-7 expression is associated with a poor response to platinum-based chemotherapy in epithelial ovarian carcinoma

BACKGROUNDnClaudin-7 (CLDN-7) is a tight junction protein that has been shown overexpressed in several human cancers. We investigated prognostic significance of CLDN-7 overexpression in patients with epithelial ovarian carcinoma (EOC) and its functional role on cell proliferation in ovarian carcinoma cell lines.nnnPATIENTS AND METHODSnCLDN-7 expression was evaluated by real-time RT-PCR and immunohistochemical analysis in 71 patients with EOC. We assessed the association of CLDN-7 expressions with prognosis of the patients including sensitivity to platinum-based chemotherapy. In vitro experiment was performed with and without inhibition of CLDN-7 by its siRNA to evaluate the sensitivity of the human ovarian cancer cells to cisplatin chemotherapy.nnnRESULTSnCLDN-7 transcripts in EOCs were significantly up-regulated compared with normal ovarian tissues (P<0.001). The expression of CLDN-7 protein was observed in majority (69/71, 97.1%) of the EOCs but not in normal ovarian tissues (P<0.001). High CLDN-7 expression in primary tumour correlated with shorter progression-free survival (PFS) of the patients (P=0.005) and poor sensitivity to platinum-based chemotherapy (P=0.024). Moreover, CLDN-7 was highly expressed in 2774 and HeyA8 human ovarian cancer cells and inhibition of CLDN-7 by its siRNA significantly enhanced the sensitivity of 2774 and HeyA8 cells to cisplatin treatment.nnnCONCLUSIONnThese findings suggest CLDN-7 expression is an independent prognostic factor for PFS and it may play a role in regulating response to platinum-based chemotherapy in the treatment of EOC.

RAR-beta expression is associated with early volumetric changes to radiation therapy in cervical cancer.

Background: To identify a molecular marker associated with volumetric changes to radiotherapy (RT) in cervical cancer, we compared gene expression profiles of an early response (ER) group with a late response (LR) group, which are defined by complete and partial disappearance of a primary cervical lesion on MRI performed 1 month after completion of RT. Methods: Microarray analysis of mRNA expression profiles was performed in 17 patients (11 in the ER and 6 in the LR group). After selection of the genes with significant differential expression, we evaluated the association of the selected genes with radioresistance in clinical specimens. Results: We identified 53 genes with differential expression on microarray analysis using the permutation test with t statistics (p ≤ 0.01). Using immunohistochemistry, we evaluated the expression of RAR-β, one of the genes selected among the differentially expressed genes. RAR-β expression was significantly down-regulated in the LR group compared with the ER group (p = 0.02). However, this gene did not predict permanent radioresistance (p = 0.19). Conclusions: RAR-β expression might be a valuable marker for the prediction of early volumetric changes to RT in cervical carcinomas. Further search for additional genes associated with early volumetric changes and radioresistance may aid in refining individual treatment strategies.

Abstract 4618: Therapeutic targeting for sphingosine kinase 1 in epithelial ovarian cancer

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CAnnPurpose: Sphingosine kinase 1 (SK1) is over-expressed in various human cancers with pro-growth effects and its inhibitors has been suggested potential anti-cancer agents. This study was designed to investigate the therapeutic potential of SK1 inhibitor in epithelial ovarian carcinoma (EOC).nnExperimental design: The expression of SK1 protein was evaluated using immunohistochemistry in patients with EOC. EOC cell lines (A2780, SKOV3ip1, A2780-CP20, SKOV3-TR, ES2 and RMG2) were used in this study to test SK1 siRNA or inhibitors. We used two kinds of SK inhibitor including SK inhibitor (for both SK1 and 2) and FTY720 (specifically inhibiting SK1) to check cell proliferation, apoptosis, angiogenesis and invasion using MTT, FACS, ELISA and wound-healing assay, respectively. Furthermore, in vivo experiments were performed to test the FTY720 on tumor growth in orthotopic EOC mouse model.nnResults: The expression of SK1 protein in primary EOC tissues was strongly observed in all of patients; however, there was no expression of SK1 protein in the normal ovarian epithelium (n=5). Blocking SK1 by its siRNA or inhibitors significantly affected cell proliferation, apoptosis, angiogenesis and invasion in A2780-PAR andnnSKOV3ip1 cells. SK1 inhibitors led to decrease of SK enzymatic activity in cells. Furthermore, utilizing the in vivo animal model (A2780-PAR), FTY720 treatment significantly decreased the total tumor weight compared with control (P < 0.05).nnConclusions: These results show that therapeutic targeting of SK1 with its inhibitor could have potentials of novel therapeutics for EOC.nnCitation Format: Jeong-Won Lee, Ji Yoon Ryu, Hye-Kyung Jeon, Young-Ae Park, Young-Jae Cho, Jung-Joo Choi, Yoo-Young Lee, Tae-Joong Kim, Chel Hun Choi, Byoung-Gie Kim, Duk-Soo Bae. Therapeutic targeting for sphingosine kinase 1 in epithelial ovarian cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4618. doi:10.1158/1538-7445.AM2014-4618

Abstract 892: Angiotensin II /angiotensin II type I receptor (AGTR1) promotes cell growth in epithelial ovarian cancer

Background: Angiotensin and its receptor, AGTR (Anigiotensin receptor) are known as main effectors molecules of renin-angiotensin system in regulating the physiological processes of the cardiovascular system. Not only do they function as an endocrine system, but they have recently reported to regulate cell proliferation, angiogenesis, invasiveness, and viabilities via inducing intercellular signaling pathways. The aim of this study is to evaluate the role of angiotensin II and AGTR1 on cell survival and proliferation in epithelial ovarian carcinoma cells. Methods: Expressions of AGTR1 were evaluated by immunohistochemistry in epithelial ovarian carcinoma tissues and analyzed the correlation between AGTR1 expression and clinicopathological characteristics of patients. For in vitro test, we checked the level of expression for angiotensin II and AGTR1 in human ovarian cancer cell lines by Western blot. A recombinant angiotensin II and its blocker losartan were treated into the cells. For cell viabilities and proliferations were estimated by MTT assay. Results: Through checking the expression of AGTR1 in human ovarian cancer cells, we selected A2780 and HeyA8 cells for in vitro tests because these cells have relatively high expression. Exogenous treatment of angiotensin II resulted in increased cell growth of both cells. Losartan, specific blocker of AGTR1, diminished the angiotensin II-induced increased cell growth. Moreover, we identified that angiotensin II activated Akt and STAT signaling through AGTR1 and pretreatment of losartan inhibited those activations. Conclusion: In this study, we inquired into the role of angiotensin II-AGTR1 interaction in ovarian cancer. They positively regulate cell survivability and proliferation and activate intercellular signaling involving Akt and STAT via suggesting their oncogenic mechanisms. Moreover, treatment of losartan, showed antiproliferative effect by inhibiting the activations of AGTR1 mediated signaling. These results suggest that AGTR1 inhibitor like as losartan could be a novel therapeutic strategy treating this cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 892. doi:1538-7445.AM2012-892