Jung-Joo Choi

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

OBJECTIVE Recent 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). METHODS We 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. RESULTS A 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. CONCLUSIONS These 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.

Increased toll-like receptor 9 expression in cervical neoplasia

Toll‐like receptors (TLRs) recognize pathogen‐associated molecular patterns (PAMPs) and enable innate immune responses. Although TLR9 has been previously considered to be expressed only in immune cells, there is now increasing evidence that TLR9 expression is present in nonimmune cells as well. In this study, we undertook to determine whether TLR9 expression was associated with disease progression in cervical neoplasia. TLR9 expression was evaluated by immunohistochemistry in 55 formalin‐fixed paraffin‐embedded cervical tissues; nine normal cervical specimens, 10 low‐grade cervical intraepithelial neoplasias (CINs), 12 high‐grade CINs, and 24 invasive squamous cell carcinomas (ISCCs). In addition, TLR9 expression was evaluated, at the RNA level, in fresh frozen cervical carcinoma tissues by real‐time quantitative RT‐PCR. Immunohistochemical staining showed that TLR9 expression was undetectable (55.6%) or weak (44.4%) in normal cervical squamous epithelial tissues, however, variable staining was observed in the basal layer of all normal endocervical glands. TLR9 expression, which was mainly observed as cytoplasmic staining, gradually increased in accordance with the histopathological grade in the following order: low‐grade CIN < high‐grade CIN < ISCC (P < 0.001), and in particular, was moderate to strong in 70% of ISCC cases. Furthermore, real‐time quantitative RT‐PCR revealed that TLR9 expression, in tumors, was significantly enhanced compared to normal cervical tissues (P = 0.012). These results suggest that TLR9 may play a significant role in tumor progression of cervical neoplasia and may represent a useful marker for malignant transformation of cervical squamous cells.

Galectin 1 expression is associated with tumor invasion and metastasis in stage IB to IIA cervical cancer

Galectin 1 is a 14-kd laminin-binding lectin involved in important biologic mechanisms of tumors, including neoplastic transformation, cell survival, angiogenesis, cell proliferation, and metastasis. In this study, we investigated the role of galectin 1 in cell survival and metastasis in cervical cancer. The expression of galectin 1 was determined in 73 formalin-fixed, paraffin-embedded cervical cancer tissues using an immunohistochemical method and compared with clinicopathologic risk factors for recurrence after surgery. To evaluate the role of galectin 1 in cell proliferation and invasion, we performed proliferation and invasion assays with galectin 1 small interfering RNA (siRNA) using cervical cancer cell lines, including HeLa and SiHa cells. Immunohistochemical analysis revealed that galectin 1 expression was found in most peritumoral stroma samples (72/73; 98.6%). Galectin 1 expression was significantly correlated with the depth of invasion in the cervix (P=.015) and lymph node metastasis (P=.045) on univariate analysis. When progression-free survival of all of the patients studied was analyzed based upon galectin 1 expression, galectin 1 expression was not correlated with progression-free survival (P=.32). Down-regulation of galectin 1 using small interfering RNA resulted in the inhibition of cell growth and proliferation of HeLa and SiHa cells. Moreover, the ability of cells to invade was significantly reduced by galectin 1 small interfering RNA. Our results revealed that high galectin 1 expression in peritumoral stroma was significantly correlated with depth of invasion in cervical lesions and lymph node metastasis of cervical cancer and that galectin 1 may be functionally involved in cell proliferation and invasion.

High galectin-1 expression correlates with poor prognosis and is involved in epithelial ovarian cancer proliferation and invasion

PURPOSE Galectin-1 (Gal-1) is a 14-kDa laminin-binding galectin involved in several biological events including regulation of tumour proliferation and metastasis. In this study, we investigated the clinical significance of Gal-1 expression and its functional role in cell proliferation and invasion in epithelial ovarian cancer (EOC). EXPERIMENTAL DESIGN We evaluated the expression of Gal-1 in 52 serous, 11 endometrioid, and 3 mucinous type EOC tumour samples from 66 patients by immunohistochemistry. In vitro experiments were performed to determine the function of Gal-1 in cell survival, proliferation, and invasion in EOC cells using siRNA and anginex, a Gal-1 inhibitor, as well as recombinant Gal-1 protein. RESULTS Patients with strong Gal-1 peritumoural staining had poorer progression-free survival (PFS) than patients with weak peritumoural staining (p=0.03). Inhibition of Gal-1 by siRNA or anginex resulted in the inhibition of cell growth and proliferation of HeyA8 and SKOV3ip1 cells. Moreover, the ability of cells to migrate was significantly reduced by treatment of cells with Gal-1 siRNA but was increased by treatment of cells with recombinant Gal-1. When we evaluated the interaction between fibroblasts (T HESCs) and cancer cells (A2780-CP20), we found that MMP-2 expression in cancer cells was affected by Gal-1 secreted by fibroblast cells, which suggests that Gal-1 in human fibroblasts might affect the invasive abilities of tumour cells. CONCLUSION Our results suggest that Gal-1 expression is a potential prognostic factor for PFS and that Gal-1 could be a novel treatment target in EOC patients.

Sentinel lymph node biopsy in papillary thyroid cancer: Comparison study of blue dye method and combined radioisotope and blue dye method in papillary thyroid cancer

AIM Occult lymph node metastasis is common in differentiated thyroid cancer (DTC). However, the role of lymph node dissection in the treatment of DTC remains controversial. The authors investigated the usefulness of methylene blue dye only method and combined radioisotope and methylene blue dye method for detecting SLN and compared the values of these two methods in patients with DTC. METHODS From February to May 2008, 97 patients with DTC underwent sentinel lymph node biopsy (SLNB). The methylene blue dye method (dye only method) was used in 54 of the 97 patients, and radioisotope and methylene blue dye method (combined method) in 43 patients. RESULTS The SLNs were identified in 89 patients, and the sensitivity and specificity of SLNB in the 97 patients were 85% and 100% respectively. For the dye only method, sensitivity, specificity, and the false negative rate (FNR) were 79%, 100%, and 21%; and for the combined method (43 patients) the corresponding figures were, 91%, 100%, and 9%, respectively. Six patients with SLN metastasis in the lateral neck underwent additional modified radical neck dissection (MRND). CONCLUSIONS SLNB was found to be feasible, repeatable, and accurate in evaluating the lymph node status in patient with DTC. The present study indicates that the combined method could reduce false negative rate and increase detection rates of sentinel lymph node metastases, especially in lateral neck, compared to the dye only method.

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

OBJECTIVE MicroRNA-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. METHODS Expressions 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. RESULTS miR-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. CONCLUSIONS In 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.

Splicing variant of AIMP2 as an effective target against chemoresistant ovarian cancer

Chemoresistance is a main cause for the failure of cancer management and intensive investigation is on-going to control chemoresistant (CR) cancers. Although NF-κB has been suggested as one of the potential targets to alleviate chemoresistance of epithelial ovarian cancer (EOC), direct targeting of NF-κB may result in an unexpected effect due to the complex regulatory network via NF-κB. Here we show that AIMP2-DX2, a splicing variant of tumor suppressor AIMP2, can be a therapeutic target to control CR EOC. AIMP2-DX2 was often highly expressed in CR EOC both in vitro and in vivo. AIMP2-DX2 compromised the tumor necrosis factor alpha-dependent pro-apoptotic activity of AIMP2 via the competitive inhibition of AIMP2 binding to TRAF2 that plays a pivotal role in the regulation of NF-κB. The direct delivery of siRNA against AIMP2-DX2 into abdominal metastatic tumors of ovarian cancer using a microneedle converged on microendoscopy significantly suppressed the growth rate of tumors. The treated cancer tissues showed an enhanced apoptosis and the decreased TRAF2 level. Thus, we suggest that the downregulation of AIMP2-DX2 can be a potent adjuvant therapeutic approach for CR EOC that resulted from an aberrant activity of NF-κB.

Gene expression profiling for the prediction of lymph node metastasis in patients with cervical cancer.

We investigated whether gene expression profiling of primary cervical tumor tissue could be used to predict lymph node (LN) metastasis and compared this with conventional magnetic resonance imaging. We obtained 43 primary cervical cancer samples (16 with LN metastasis and 27 without LN metastasis) for microarray analysis. A prediction model for LN metastasis from the training set was developed by support vector machine methods using a 10‐fold cross‐validation. The ‘LN prediction model’ derived from the signature of 156 distinctive genes (P < 0.01) had a prediction accuracy of 77%. Correlation between mRNA expressions measured by microarray and semiquantitative reverse transcription–polymerase chain reaction was ascertained in four (RBM8A, SDHB, SERPINB13, and γ‐interferon) out of 10 genes. Magnetic resonance imaging showed accuracy (69%) for the prediction of LN metastasis. These results suggest that gene expression profiling allows reliable prediction of LN metastasis in cervical cancer. (Cancer Sci 2008; 99: 31–38)

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.