Annual Report 2017
Division of Biomarker Discovery (Tsukiji Campus)
Hiroki Sasaki, Rie Komatsuzaki, Fumiko Chiwaki, Masayuki Komatsu, Kazuaki Yamamoto, Takashi Takeda, Tsukasa Fujimoto
Our team and what we do
The three major research areas of the Division of Biomarker Discovery were: 1) preclinical studies using newly established gastric, esophageal, pancreatic, and ovarian cancer cell lines for derivation of industrial and academia seeds/drugs to the Exploratory Oncology Research & Clinical Trial Center (EPOC), 2) basic research and development of personalized cancer diagnosis and treatment for gastric cancer (GC) and esophageal squamous cell carcinoma (ESCC), and 3) provision and sharing omics information of originally-established cancer cell lines for facilitating translational research (TR) on Asian cancers in Japan.
Research activities
1. Preclinical Studies Using Newly Established Cell Lines from Common Cancers in Asia
Genome-wide genetic information in about 1,000 cancer cell lines is available on COSMIC DB (Sanger Institute, UK); however, among them, only 28 cell lines are derived from GC. Since driver gene mutation frequency in a certain cancer is often less than 5%, the establishment of cell lines from each patient to be analyzed is desired for functional selection of driver gene mutations. Furthermore, almost all of the 28 GC cell lines were established many years ago, thereby, the clinical and pathological information is insufficient. The wait is on for the establishment of new GC cell lines, especially from metastatic sites after therapy. Peritoneal metastasis is most frequent in GCs, especially diffuse-type GCs. In 2010-2017, we successfully established 87 diffuse-type GC cell lines (National Cancer Center Stomach Cancer (NSC) series) from 49 patients, and also established 32 pancreatic and nine ovarian cancer cell lines, and so on. We are conducting omics analyses for gene expression and copy number variation, and hot spot- and genome wide-gene alteration in these cell lines. Moreover, for in vivo preclinical study, their tumorigenicity and histopathological characteristics in the xenograft, such as fibroblast rich-, hypovascular-, and dormant-state, were evaluated. Through collaboration with five pharmaceutical industries, in vitro and in vivo preclinical studies were conducted to derivate clinical trials in the EPOC.
2. Basic Research and Development of Personalized Diagnosis and Treatment for GC and ESCC
The study for GC: GC is one of the leading causes of cancer-related death worldwide.
Histopathologically, GCs can be divided into two major categories: an intestinal-type and a diffuse-type. Unlike the decreasing incidence of an intestinal-type, the prevalence of a diffuse-type is reportedly increasing worldwide. Although therapeutic results for GC have recently been improved, the prognosis of patients with advanced diffuse-type GC still remains poor. Peritoneal dissemination is a frequent form of metastasis of diffuse-type GC. The survival rates of patients with peritoneal metastasis (P1) at three and five years are only 9.8% and 0%, respectively. Peritoneal lavage cytology (CY) provides important prognostic information for GC after surgery. CY positive (CY1) is well known as a poor prognostic factor in advanced GC patients. However, the optical therapeutic strategy for patients with CY1 has not yet been established. The two-, three-, and five-year survival rates of GC patients with no peritoneal metastasis (P0) but with CY1 are 25.3, 13.8, and 7.8%, respectively. Development of a new therapeutic modality for peritoneal metastasis of GC is very important for improving the outcome of those patients with P1/CY1 or P0/CY1. For personalized medicine, we have developed and improved sensitivity of mini DNA chips containing six markers and three control genes for predicting GC recurrence from peritoneal washings. The CY offers important prognostic information for GC after surgery, but has only a limited sensitivity and the task requires great skill. In 2017, we obtained data from preoperative samples from 316 cases and pre- and post-neoadjuvant chemotherapy samples from 114 cases by an improved method.
The study for ESCC: Definitive chemoradiotherapy (CRT) is a less invasive therapy for ESCC; however, the five-year survival rate of locally advanced ESCC patients was only 37%. Therefore, a prediction of CRT-responder is awaited. We have successfully identified five intrinsic subtypes (1a/M1, 2a/I, 3b, 5/M2, and 7/E) of ESCCs by gene expression profile-based unsupervised clustering of 274 biopsy samples obtained before treatment. For the cases treated with CRT, the five-year survival rate was 24% in subtype M2, whereas it was 74% in subtype E. Furthermore, we found transcriptional pathways activated characteristically in each subtype; the subtype E showed a differentiation phenotype, while non-E subtypes including M1 and M2 showed an epithelial-mesenchymal transition phenotype. In 2017, we reported that a transcriptional factor, single-minded family bHLH transcription factor 2 (SIM2) increases CRT sensitivity through differentiation of PDPN-positive malignant basal cells and repression of DNA repair and antioxidant enzymes (FANCD2, XRCC5, and SOD2) by cooperation with ARNT in ESCC (Tamaoki M et al., Cancer Sci, 2018), and also reported that SIM2 attenuates resistance to hypoxia and tumor growth by transcriptional suppression of HIF1A in uterine cervical squamous cell carcinoma (Nakamura K et al., Scientific Rep, 2018). To develop an in vitro diagnostic (IVD) for predicting subtype E with high SIM2 expression, we are collaborating with a pharmaceutical company and ten institutes for clinical investigation of 225 ESCC patients with the support of the Japan Agency for Medical Research and Development (AMED), and are preparing the investigator-initiated clinical trial of the immune checkpoint inhibitor for subtype I that shows tumor-specific cytotoxic T-lymphocyte activation signatures by CRT.
3. Facilitating TR by providing originally-established cancer cell lines
In 2017, for facilitating TR on Asian cancers in Japan, we provided originally-established cancer cell lines to three inside and two outside researchers and an industry under the Material Transfer Agreement (MTA).
Education
We supported a postdoctoral fellow through design of a research, writing a paper and grant applications, and nurtured four assisting scientists, a graduate school student, and two undergraduate school students through experiments, discussion, and writing a report or paper.
Future prospects
To develop IVD and to derivate new drugs to the EPOC, collaboration with pharmaceutical industries will be continued. To facilitate innovative basic research and to create intellectual properties, we will make continuous efforts to support inside and outside researchers through providing established cell lines with omics information.
List of papers published in January 2017 - March 2018
Journal
1. Nakamura K, Komatsu M, Chiwaki F, Takeda T, Kobayashi Y, Banno K, Aoki D, Yoshida T, Sasaki H. SIM2l attenuates resistance to hypoxia and tumor growth by transcriptional suppression of HIF1A in uterine cervical squamous cell carcinoma. Sci Rep, 7:14574, 2017
2. Nagasato M, Rin Y, Yamamoto Y, Henmi M, Hiraoka N, Chiwaki F, Matsusaki K, Tagawa M, Sasaki H, Aoki K. A Tumor-targeting Adenovirus with High Gene-transduction Efficiency for Primary Pancreatic Cancer and Ascites Cells. Anticancer Res, 37:3599-3605, 2017
3. Nishimura T, Tamaoki M, Komatsuzaki R, Oue N, Taniguchi H, Komatsu M, Aoyagi K, Minashi K, Chiwaki F, Shinohara H, Tachimori Y, Yasui W, Muto M, Yoshida T, Sakai Y, Sasaki H. SIX1 maintains tumor basal cells via transforming growth factor-beta pathway and associates with poor prognosis in esophageal cancer. Cancer Sci, 108:216-225, 2017
4. Fukuoka S, Kojima T, Koga Y, Yamauchi M, Komatsu M, Komatsuzaki R, Sasaki H, Yasunaga M, Matsumura Y, Doi T, Ohtsu A. Preclinical efficacy of Sym004, novel anti-EGFR antibody mixture, in esophageal squamous cell carcinoma cell lines. Oncotarget, 8:11020-11029, 2017
5. Kamei R, Yoshimura K, Yoshino S, Inoue M, Asao T, Fuse M, Wada S, Kuramasu A, Furuya-Kondo T, Oga A, Iizuka N, Suzuki N, Maeda N, Watanabe Y, Matsukuma S, Iida M, Takeda S, Ueno T, Yamamoto N, Fukagawa T, Katai H, Sasaki H, Hazama S, Oka M, Nagano H. Expression levels of UL16 binding protein 1 and natural killer group 2 member D affect overall survival in patients with gastric cancer following gastrectomy. Oncology letters, 15:747-754, 2018
6. Tamaoki M, Komatsuzaki R, Komatsu M, Minashi K, Aoyagi K, Nishimura T, Chiwaki F, Hiroki T, Daiko H, Morishita K, Sakai Y, Seno H, Chiba T, Muto M, Yoshida T, Sasaki H. Multiple roles of single-minded 2 in esophageal squamous cell carcinoma and its clinical implications. Cancer Sci, 109:1121-1134, 2018