Hankyeom Kim

HRG-β1-driven ErbB3 signaling induces epithelial-mesenchymal transition in breast cancer cells

BackgroundHeregulin (HRG; also known as neuregulin) is a ligand for ErbB3. One of its isotypes, HRG-β1, binds to ErbB3 and forms heterodimers with other ErbB family members, thereby enhancing the proliferation and tumorigenesis of breast cancer cells. HRG stimulation may contribute to the progression of epithelial–mesenchymal transition (EMT) and tumor metastasis in breast cancer. Majority of studies regarding EMT has been concentrated on TGF-β signaling. Therefore, we investigated whether the HRG-β1 and ErbB3 activate Smad2 signaling during process of EMT in breast cancer cells.MethodsThe SK-BR-3 and MCF7 breast cancer cell lines were used. The expressions of phospho-Smad2 and EMT markers were observed by western blotting and immunofluorescence assays after treatment with HRG-β1. The cell motility and invasiveness were determined by wound healing and matrigel invasion assays. Smad2 and ErbB3 small interfering RNA (siRNA) transfections were performed to assess the involvement of ErbB3 and Smad2 in HRG-β1-induced EMT.ResultsHRG-β1 induced EMT through activation of Smad2. The expression of E-cadherin was decreased after HRG-β1 treatment, while the expressions of Snail, vimentin, and fibronectin were increased. The HRG-β1-induced expressions of Snail, vimentin, and fibronectin, and nuclear colocalization of phospho-Smad2 and Snail were inhibited by pretreatment with a PI3k inhibitor, LY294002, or two phospho-Smad2 inhibitors, PD169316 or SB203580 and cancer cell migration by HRG-β1 was inhibited. Knockdown of Smad2 by siRNA transfection suppressed the expressions of Snail and fibronectin in response to HRG-β1 stimulation and knockdown of ErbB3 suppressed the expressions of phospho-Smad2, Snail, and fibronectin induced by HRG-β1, whereas E-cadherin was increased compared with control siRNA-transfected cells. Knockdown of ErbB3 and Smad2 also decreased SK-BR-3 and MCF7 cell invasion.ConclusionsOur data suggest that HRG-β1 and ErbB3 induce EMT, cancer cell migration and invasion through the PI3k/Akt-phospho-Smad2-Snail signaling pathway in SK-BR-3 and MCF7 breast cancer cells.

Human papillomavirus genotyping by oligonucleotide microarray and p16INK4A expression in uterine cervical intraepithelial neoplasm and in invasive carcinoma in Korean women

For evaluating the diagnostic significance of p16INK4A over‐expression in the uterine cervical intraepithelial neoplasm and in invasive carcinoma, human papillomavirus (HPV) was detected and genotyped by oligonucleotide microarray in archival tissues of 117 cervical specimens, including 47 invasive squamous cell carcinomas (SCC), 30 cases of cervical intraepithelial neoplasia (CIN), 20 adenocarcinomas, and 20 cases of non‐neoplastic cervix. The expression of p16INK4A protein was immunohistochemically studied in these cases and in five HPV‐positive and one HPV‐negative cervical cancer cell lines. HPV was detected in 50% of CIN, 61.7% of SCC, and 45.5% of adenocarcinomas. p16INK4A expression was seen in all 20 cases of adenocarcinoma, 78.7% (37/47) of SCC, and 96.7% (29/30) of CIN, but not in any cases of the non‐neoplastic cervix. There was no difference in p16INK4A expression between the HPV‐positive and HPV‐negative cervical lesions. All HPV‐positive and ‐negative cervical cancer cell lines expressed p16INK4A protein. In conclusion, the presence of p16INK4A expression in cervical squamous and glandular epithelium indicates the existence of dysplasia or malignancy in the uterine cervix, regardless of HPV infection.

Immune regulatory effects of simvastatin on regulatory T cell-mediated tumour immune tolerance

Statins are potent inhibitors of hydroxyl‐3‐methylglutaryl co‐enzyme A (HMG‐CoA) reductase, and have emerged as potential anti‐cancer agents based on preclinical evidence. In particular, compelling evidence suggests that statins have a wide range of immunomodulatory properties. However, little is known about the role of statins in tumour immune tolerance. Tumour immune tolerance involves the production of immunosuppressive molecules, such as interleukin (IL)‐10, transforming growth factor (TGF)‐β and indoleamine‐2,3‐dioxygenase (IDO) by tumours, which induce a regulatory T cell (Treg) response. In this study, we investigated the effect of simvastatin on the production of IL‐10, TGF‐β and IDO production and the proliferation of Tregs using several cancer cell lines, and Lewis lung cancer (3LL) cells‐inoculated mouse tumour model. Simvastatin treatment resulted in a decrease in the number of cancer cells (3LL, A549 and NCI‐H292). The production of the immune regulatory markers IL‐10, TGF‐β in 3LL and NCI‐H292 cells increased after treatment with simvastatin. The expression of IDO and forkhead box P3 (FoxP3) transcription factor was also increased in the presence of simvastatin. In a murine 3LL model, there were no significant differences in tumour growth rate between untreated and simvastatin‐treated mice groups. Therefore, while simvastatin had an anti‐proliferative effect, it also exhibited immune tolerance‐promoting properties during tumour development. Thus, due to these opposing actions, simvastatin had no net effect on tumour growth.

A Novel Adenovirus in Chinstrap Penguins (Pygoscelis antarctica) in Antarctica

Adenoviruses (family Adenoviridae) infect various organ systems and cause diseases in a wide range of host species. In this study, we examined multiple tissues from Chinstrap penguins (Pygoscelis antarctica), collected in Antarctica during 2009 and 2010, for the presence of novel adenoviruses by PCR. Analysis of a 855-bp region of the hexon gene of a newly identified adenovirus, designated Chinstrap penguin adenovirus 1 (CSPAdV-1), showed nucleotide (amino acid) sequence identity of 71.8% (65.5%) with South Polar skua 1 (SPSAdV-1), 71% (70%) with raptor adenovirus 1 (RAdV-1), 71.4% (67.6%) with turkey adenovirus 3 (TAdV-3) and 61% (61.6%) with frog adenovirus 1 (FrAdV-1). Based on the genetic and phylogenetic analyses, CSPAdV-1 was classified as a member of the genus, Siadenovirus. Virus isolation attempts from kidney homogenates in the MDTC-RP19 (ATCC® CRL-8135™) cell line were unsuccessful. In conclusion, this study provides the first evidence of new adenovirus species in Antarctic penguins.

Genetic and molecular epidemiological characterization of a novel adenovirus in antarctic penguins collected between 2008 and 2013

Antarctica is considered a relatively uncontaminated region with regard to the infectious diseases because of its extreme environment, and isolated geography. For the genetic characterization and molecular epidemiology of the newly found penguin adenovirus in Antarctica, entire genome sequencing and annual survey of penguin adenovirus were conducted. The entire genome sequences of penguin adenoviruses were completed for two Chinstrap penguins (Pygoscelis antarctica) and two Gentoo penguins (Pygoscelis papua). The whole genome lengths and G+C content of penguin adenoviruses were found to be 24,630–24,662 bp and 35.5–35.6%, respectively. Notably, the presence of putative sialidase gene was not identified in penguin adenoviruses by Rapid Amplification of cDNA Ends (RACE-PCR) as well as consensus specific PCR. The penguin adenoviruses were demonstrated to be a new species within the genus Siadenovirus, with a distance of 29.9–39.3% (amino acid, 32.1–47.9%) in DNA polymerase gene, and showed the closest relationship with turkey adenovirus 3 (TAdV-3) in phylogenetic analysis. During the 2008–2013 study period, the penguin adenoviruses were annually detected in 22 of 78 penguins (28.2%), and the molecular epidemiological study of the penguin adenovirus indicates a predominant infection in Chinstrap penguin population (12/30, 40%). Interestingly, the genome of penguin adenovirus could be detected in several internal samples, except the lymph node and brain. In conclusion, an analysis of the entire adenoviral genomes from Antarctic penguins was conducted, and the penguin adenoviruses, containing unique genetic character, were identified as a new species within the genus Siadenovirus. Moreover, it was annually detected in Antarctic penguins, suggesting its circulation within the penguin population.

Allium sativum Potentiates Suicide Gene Therapy for Murine Transitional Cell Carcinoma

This study evaluated the synergistic effect of Allium sativum (AS) with suicide gene therapy for transitional cell carcinoma (TCC) of the bladder. Subcutaneous TCCs were established in syngeneic C3H/He mice with 1 × 105 MBT-2 cells. AS liquid extract was injected at the site of tumor transplantation on Day 1 for three weeks (Experiment I) and into the established tumors weekly for five weeks (Experiment II) in combination with or without gene therapy using a replication-defective adenoviral vector containing a herpes simplex virus thymidine kinase (HSV-TK) gene under the transcriptional control of Rous sarcoma virus (RSV) promoter (Ad-RSV-TK, 5 × 108 plaque-forming units) plus ganciclovir (20 mg/kg/day ip). AS demonstrated a statistically significant reduction in incidence of TCC (cumulative dose 25 mg of AS). Combination AS-suicide gene therapy significantly inhibited the tumor growth compared with the controls, which was evidenced by apoptosis on histomorphological and immunohistochemical studies. These results suggest that AS had a definite antitumor effect in inhibiting tumorigenesis and growth of TCC in a murine model. AS treatment combined with suicide gene therapy had significant additive antitumor effects on TCC and may provide a novel and effective treatment modality for TCC of the bladder.

Carcinosarcoma in the Cecum

Carcinosarcoma of the colon is rare. Seventeen cases have been reported in the English literature. Most cases occurred in the left side of the colon. Indeed, there is only one reported case of cecal carcinosarcoma. Carcinosarcoma has a tendency to distantly metastasize and shows dismal prognosis. We report a case of carcinosarcoma in the cecum and review the literature describing colonic carcinosarcoma.

A Case of Malignant PEComa of the Uterus Associated with Intramural Leiomyoma and Endometrial Carcinoma

Perivascular epithelioid cell tumors (PEComas) refers to a family of mesenchymal neoplasms composed of angiomyolipomas, clear cell “sugar” tumors of the lung, and lymphangioleiomyomatoses. These tumors have a distinctive and common component of perivascular epithelioid cells that show an association with blood vessel walls and immunohistochemically display myomelanocytic differentiation. The unique neoplasms have been shown to have an expanded range through a variety of case reports, including visceral, intra-abdominal, soft tissue, and bone tumors. The retroperitoneum, abdominopelvic region, and uterus have been reported to be the most common sites. Most PEComas follow a benign course. However, reports of malignant PEComas are increasing. Many papers have described uterine PEComas, but to our knowledge, there have not yet been any reports of a malignant PEComa arising concomitant with another epithelial tumor and mesenchymal tumor. We report herein the case of a 67-year-old woman who experienced a malignant uterine PEComa infiltrating a preexisting intramural leiomyoma with synchronous well differentiated endometrial carcinoma and multiple liver and lung metastases.

Analysis of human tissue management models for medical research: preparation for implementation of the 2012 revision of the Bioethics and Safety Act of Korea.

Efficient management of human tissue samples is a critical issue; the supply of samples is unable to satisfy the current demands for research. Lack of informed consent is also an ethical problem. One of the goals of the 2012 revision of Koreas Bioethics and Safety Act was to implement regulations that govern the management of human tissue samples. To remain competitive, medical institutions must prepare for these future changes. In this report, we review two tissue management models that are currently in use; model 1 is the most common system utilized by hospitals in Korea and model 2 is implemented by some of the larger institutions. We also propose three alternative models that offer advantages over the systems currently in use. Model 3 is a multi-bank model that protects the independence of physicians and pathologists. Model 4 utilizes a comprehensive single bioresource bank; although in this case, the pathologists gain control of the samples, which may make it difficult to implement. Model 5, which employs a bioresource utilization steering committee (BUSC), is viable to implement and still maintains the advantages of Model 4. To comply with the upcoming law, we suggest that physicians and pathologists in an institution should collaborate to choose one of the improved models of tissue management system that best fits for their situation.

Abstract 5369: Methylation profile of markers for epithelial-mesenchymal transition and stem cell in tamoxifen-resistant MCF-7 breast cancer cell line.

DNA methylation plays a key role in the epigenetic-based regulation of gene expression. Several genes that showed increased hypomethylations of gene promotors in antiestrogen-resistant breast cancer cells were found to be increased in tumor cells and possess oncogenic activity. The purpose of this study is to investigate the differences of methylation profiles, especially EMT markers, between tamoxifen-sensitive breast cancer cell lines and tamoxifen-resistant cell lines using MCF7 and tamoxifen-resistant MCF7 (MCF7-R) cell lines, and then to indentify the presence of the identified markers in the breast tissues of recurred patients with antiestrogen treatments. Bisulphite-converted genomic DNA was assayed on Infinium Human Methylation 450K Beadchips using the Illumina Infinium HD methylation assay kit using four groups of the cells including MCF7, MCF7-R, MCF+E2 and MCF7-R+E2. . In MCF7-R cells, 31023 CpG sites showed altered methylations, with 13617 hypomethylated and 17406 hypermethylated, compared with MCF7. The numbers of hypomethylated and hypermethylated CpG sites in the promoter regions were 4719 and 3347, respectively. Among the well-known EMT markers, the genes meeting the results of methylation status selected were CTNNB1, SNAIL2, TWIST1, LEF1, GSC and ETS1. Although the results of the current study suggest that aberrant DNA methylations of EMT markers are not the main force driving the molecular biology of resistance against antiestrogen therapy, these will contribute and result in to some extent. Citation Format: Youngseok Lee, Aeree Kim, Han-Kyeom Kim. Methylation profile of markers for epithelial-mesenchymal transition and stem cell in tamoxifen-resistant MCF-7 breast cancer cell line. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5369. doi:10.1158/1538-7445.AM2013-5369