Hiroki Imaoka

Circulating microRNA-203 predicts prognosis and metastasis in human colorectal cancer.

Background and aims Distant metastasis is a major cause of deaths in patients with colorectal cancer (CRC), which is partly due to lack of robust metastasis-predictive biomarkers. In spite of the important function of microRNA (miR)-203 in cancer metastasis, its clinical significance in CRC metastasis remains unknown. Here, we evaluated the potential role of serum miR-203 as a non-invasive biomarker for CRC metastasis. Methods MiR-203 expression was quantified by quantitative reverse-transcription PCR in 58 pairs of primary CRC (pCRC) and corresponding matched liver metastasis (LM), as well as 186 serum and 154 matched tissue specimens from patients with CRC in cohort 1. Next, we performed validation of miR-203 levels in serum from 144 patients with CRC in an independent cohort (cohort 2). Mouse models of CRC-associated metastases were established to identify the source of circulating miR-203. Expression patterns of miR-203 in tissues were determined by in situ hybridisation. Results MiR-203 expression was significantly upregulated in LM compared with matched pCRC tissues. Serum miR-203 levels were significantly upregulated in a stage-dependent manner, and high miR-203 expression was associated with poor survival in patients with CRC in both patient cohorts. Increased miR-203 levels in serum indicated high risk for poor prognosis (HR=2.1), as well as metastasis to lymph nodes (OR=2.5), liver (OR=6.2), peritoneum (OR=7.2) and distant organs (OR=4.4). Serum miR-203 levels were significantly higher in animals with liver or systemic metastasis compared with controls. Conclusions High levels of serum miR-203 associate with poor survival and metastasis, suggesting it to be a promising non-invasive prognostic and metastasis-predictive biomarker in patients with CRC.

Circulating microRNA-1290 as a novel diagnostic and prognostic biomarker in human colorectal cancer

BACKGROUND Circulating microRNAs (miRNAs) are attracting major interest as potential non-invasive biomarkers for colorectal cancer (CRC). This study aimed to identify a novel serum miRNA biomarker for the early detection and/or evaluating prognosis of CRC patients. PATIENTS AND METHODS Comprehensive miRNA array analysis was carried out using serum samples from patients with colorectal neoplasia and healthy controls. Next, to verify whether the candidate miRNA possessed a secretory potential, we screened miRNA expression levels in culture medium from 2 CRC cell lines, followed by serum analysis from 12 stage IV CRC, 12 adenoma, and 12 control subjects. Thereafter, we validated expression of candidate miRNAs in 179 primary CRC tissues, as well as serum samples from an independent cohort of 211 CRCs, 56 adenomas, and 57 control subjects. RESULTS Through microarray analysis, we identified significantly higher levels of miRNA-1290 (miR-1290) in serum from patients with colorectal adenomas and cancers. We verified miR-1290 overexpression in serum of CRC patients in a training cohort. In the validation cohort, serum miR-1290 levels were significantly up-regulated in patients with colorectal adenomas (P < 0.0001) and cancers (P < 0.0001). Serum miR-1290 levels could robustly distinguish adenoma [area under the curve (AUC) = 0.718] and CRC patients (AUC = 0.830) from normal subjects. High miR-1290 expression in serum and tissue was significantly associated with tumor aggressiveness and poor prognosis. Moreover, serum miR-1290 levels were an independent prognostic factor [hazard ratio (HR) = 4.51; 95% confidence interval (CI) = 1.23-23.69; P = 0.0096] and an independent predictor for tumor recurrence (hazard ratio = 3.92; 95% confidence interval = 1.11-25.14; P = 0.032) in CRC. CONCLUSIONS Serum miR-1290 is a novel biomarker for early detection, recurrence, and prognosis in CRC.

RacGAP1 expression, increasing tumor malignant potential, as a predictive biomarker for lymph node metastasis and poor prognosis in colorectal cancer

Rac GTPase-activating protein (RacGAP) 1 plays a key role in controlling various cellular phenomena including cytokinesis, transformation, invasive migration and metastasis. This study investigated the function and clinical significance of RacGAP1 expression in colorectal cancer (CRC). The intrinsic functions of RacGAP1 in CRC cells were analyzed using small interfering RNA (siRNA). We analyzed RacGAP1 mRNA expression in surgical specimens from 193 CRC patients (Cohort 1) by real-time PCR. Finally, we validated RacGAP1 protein expression using formalin-fixed paraffin-embedded samples from 298 CRC patients (Cohort 2) by immunohistochemistry. Reduced RacGAP1 expression by siRNA in CRC cell lines showed significantly decreased cellular proliferation, migration and invasion. In Cohort 1, RacGAP1 expression in CRC was significantly higher than in adjacent normal mucosa and increased according to tumor node metastasis stage progression. High RacGAP1 expression in tumors was significantly associated with progression and prognosis. In Cohort 2, RacGAP1 protein was overexpressed mainly in the nuclei of CRC cells; however, its expression was scarcely observed in normal colorectal mucosa. RacGAP1 protein expression was significantly higher in CRC patients with higher T stage, vessel invasion and lymph node and distant metastasis. Increased expression of RacGAP1 protein was significantly associated with poor disease-free and overall survival. Multivariate analyses revealed that high RacGAP1 expression was an independent predictive marker for lymph node metastasis, recurrence and poor prognosis in CRC. Our data provide novel evidence for the biological and clinical significance of RacGAP1 as a potential biomarker for identifying patients with lymph node metastasis and poor prognosis in CRC.

Serum angiopoietin-like protein 2 as a potential biomarker for diagnosis, early recurrence and prognosis in gastric cancer patients.

Chronic inflammation of gastric mucosa by Helicobacter pylori infection can initiate gastric carcinogenesis. As angiopoietin-like protein 2 (ANGPTL2) mediates inflammation and inflammation-associated carcinogenesis, we investigated the functional and clinical significance of ANGPTL2 in human gastric cancer (GC). SiRNA knockdown studies were performed for the functional assessment of ANGPTL2 in GC cell lines. ANGPTL2 expression was evaluated immunohistochemically in 192 tissue specimens from GC patients. In addition, we screened serum ANGPTL2 levels from 32 GC patients and 23 healthy controls; and validated these results in 194 serum samples from GC patients and 45 healthy controls by ELISA. ANGPTL2 knockdown caused anoikis and inhibited proliferation, invasion and migration in GC cells. ANGPTL2 expression was upregulated in GC tissues compared to normal gastric mucosa; and high ANGPTL2 expression was significantly associated with tumor progression, early recurrence (P = 0.003) and poor prognosis (P = 0.007). Serum ANGPTL2 in GC patients was significantly higher than for healthy controls (P < 0.05), and accurately distinguished GC patients from healthy control (AUC = 0.865). The validation step confirmed significantly higher serum ANGPTL2 levels in GC patients than healthy controls (P < 0.0001). Receiver operating characteristic curves yielded robust AUC value (0.831) accompanied by high sensitivity (73.0%) and specificity (82.2%) in distinguishing GC patients from healthy controls. High serum ANGPTL2, rather than its expression in matched tissues, was significantly associated with tumor progression, and emerged as an independent marker for recurrence (HR: 5.05, P = 0.0004) and prognosis (HR: 3.6, P = 0.01). Serum ANGPTL2 expression is a potential noninvasive biomarker for diagnosis, early recurrence and prognosis of GC patients.

Successful identification of a predictive biomarker for lymph node metastasis in colorectal cancer using a proteomic approach

Colorectal cancer (CRC)-associated mortality is primarily caused by lymph node (LN) and distant metastasis, highlighting the need for biomarkers that predict LN metastasis and facilitate better therapeutic strategies. We used an Isobaric Tags for Relative and Absolute Quantification (iTRAQ)-based comparative proteomics approach to identify novel biomarkers for predicting LN metastasis in CRC patients. We analyzed five paired samples of CRC with or without LN metastasis, adjacent normal mucosa, and normal colon mucosa, and differentially expressed proteins were identified and subsequently validated at the protein and/or mRNA levels by immunohistochemistry and qRT-PCR, respectively. We identified 55 proteins specifically associated with LN metastasis, from which we selected ezrin for further analysis and functional assessment. Expression of ezrin at both the protein and mRNA levels was significantly higher in CRC tissues than in adjacent normal colonic mucosa. In univariate analysis, high ezrin expression was significantly associated with tumor progression and poor prognosis, which was consistent with our in vitro findings that ezrin promotes the metastatic capacity of CRC cells by enabling cell invasion and migration. In multivariate analysis, high levels of ezrin protein and mRNA in CRC samples were independent predictors of LN metastasis. Our data thus identify ezrin as a novel protein and mRNA biomarker for predicting LN metastasis in CRC patients.

Prognostic relevance of stromal CD26 expression in rectal cancer after chemoradiotherapy

BackgroundCD26 is a transmembrane glycoprotein whose role in various types of malignancies, along with the potential therapeutic and diagnostic targets, has been evaluated. Preoperative chemoradiotherapy (CRT) is an effective tool for local control of rectal cancer, but the rate of disease recurrence remains high. The aim of this study was to clarify the association between CD26 expression and rectal cancer after preoperative CRT.MethodsA total of 85 patients with rectal cancer who had undergone preoperative CRT were enrolled in this study. We investigated CD26 expression in residual tumors and the surrounding stromal tissue using immunohistochemistry. Additionally, stromal CD26 gene expression was assessed by real-time quantitative polymerase chain reaction.ResultsPatients with high CD26 expression in cancer tissue more frequently had serosal invasion, vascular invasion, and a poor pathological response. High expression of CD26 in the tumor stroma was significantly correlated with histology and tumor recurrence. High CD26 expression in the stroma, but not the tumor itself, was significantly correlated with a poor prognosis. Patients expressing CD26 in the tumor stroma, based on transcriptional analysis, also had a significantly poorer prognosis than those without the expression. In multivariate analysis, lymph node metastasis and high stromal CD26 expression were identified as independent prognostic factors in patients with rectal cancer after neoadjuvant CRT.ConclusionStromal CD26 expression after preoperative CRT was significantly associated with tumor recurrence and prognosis in rectal cancer patients. Our data suggest that stromal CD26 plays an important role and is a potential therapeutic target in tumor relapse.

Abstract 968: Circulating microRNA-1290 as a novel diagnostic and prognostic biomarker in human colorectal cancer

Background & Aims: MicroRNAs (miRNAs) play a crucial role in diverse cellular biological processes such as differentiation, proliferation, migration, invasion and survival. MiRNA expression patterns are found to be frequently dysregulated in human tumors, which is currently being exploited both from a basic science perspective and for its clinical usefulness as disease biomarkers. Circulating miRNAs are attracting major interest as potential noninvasive biomarkers for colorectal cancer (CRC). This study aimed to identify a novel serum miRNA biomarker for the early detection and/or evaluating prognosis of CRC patients. Methods: Comprehensive miRNA array analysis was performed using serum samples from patients with colorectal neoplasia (CRC: n = 3, adenoma: n = 3) and healthy controls (n = 3). Next, to verify whether the candidate miRNA possessed a secretory potential, we screened miRNA expression levels in culture medium from 2 CRC cell lines, followed by serum analysis from 12 stage IV CRC, 12 adenoma and 12 control subjects. Thereafter, we validated expression of candidate miRNAs in 179 primary CRC tissues, as well as serum samples from an independent cohort of 211 CRCs, 56 adenomas, and 57 control subjects. Results: Through microarray analysis, we identified significantly higher levels of miRNA-1290 (miR-1290) in serum from patients with colorectal adenomas and cancers. We verified miR-1290 overexpression in serum of CRC patients in a training cohort. In the validation cohort, serum miR-1290 levels were significantly upregulated in patients with colorectal adenomas (P Conclusions: Serum miR-1290, which might be secreted from primary CRC, is a novel diagnostic and prognostic biomarker in CRC. Citation Format: Yuji Toiyama, Hiroki Imaoka, Hiroyuki Fujikawa, Junichiro Hiro, Susumu Saigusa, Koji Tanaka, Yasuhiro Inoue, Yasuhiko Mohri, Takao Mori, Toshio Kato, Ajay Goel, Masato Kusunoki. Circulating microRNA-1290 as a novel diagnostic and prognostic biomarker in human colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 968.

Systemic Acute-phase Response in Laparoscopic and Open Ileal Pouch Anal Anastomosis in Patients With Ulcerative Colitis: A Case-matched Comparative Study.

Aim: The current trial was designed to study and compare the postoperative outcomes and systemic acute responses between patients undergoing laparoscopic-ileal pouch anal anastomosis (LAP-IPAA) and open IPAA for ulcerative colitis. Methods: The clinical records of patients who underwent 89 restorative proctocolectomy procedures with IPAA were reviewed. After determining which patients underwent LAP-IPAA versus open IPAA, an equivalent number of controls matched for age and ulcerative colitis severity were selected. Results: Twenty of 22 patients who underwent laparoscopic surgery met the inclusion criteria. Patients who underwent LAP-IPAA had significantly shorter times to first walking (P=0.021) and food intake (P=0.0003). The LAP-IPAA group had significantly lower interleukin-6 and interleukin-1ra levels soon after surgery (P=0.011 and P=0.0076). The LAP-IPAA group had significantly lower C-reactive protein levels on postoperative day 1 (P=0.0027). Conclusions: LAP-IPAA is a less-invasive operative procedure than open IPAA with respect to the postoperative systemic inflammatory response and postoperative recovery.

Intussusception of Rectosigmoid Colon Cancer Mimicking a Pedunculated Tumor

Intussusception in adults is a rare phenomenon involving the colon in approximately 20% of cases. A 65-year-old man was hospitalized with anorexia, anemia, dehydration, and melena. Digital rectal examination revealed a palpable mass approximately 5 cm from the anal verge. The mass moved between the rectosigmoid colon and the rectum below the peritoneal reflection during radiographic examinations and during sigmoidoscopy. We strongly suspected a rectosigmoid pedunculated tumor and performed a low anterior resection. Intraoperatively we observed intussusception of the rectosigmoid colon with easy manual reduction. The tumor was palpable in the rectosigmoid colon. The postoperative course was uneventful. This case illustrates intussusception of a rectosigmoid type 1 colon adenocarcinoma mimicking a pedunculated tumor.

Complete laparoscopic total mesorectal excision with an intersphincteric resection and coloplasty pouch anal anastomosis for lower rectal cancer

This pilot study aimed to develop a new technique, complete laparoscopic total mesorectal excision (TME) with an intersphincteric resection (ISR) and coloplasty pouch anal anastomosis to avoid any further abdominal incision other than laparoscopic port sites, and to assess the impact on short-quality of life and oncological outcomes of this technique. After laparoscopic TME, large bowel was dissected at the level of the promontory. Then, laparoscopic construction of the coloplasty pouch was performed. Simultaneously, a rectal specimen with ISR was excised using the transanal approach. Coloplasty pouch was gently pulled from pelvic thorough anal and a hand-sewn coloplasty pouch anal anastomosis was created. We had performed 8 surgeries using the new technique. Though one patient developed pelvic infections, but intestinal continuity could be maintained and no local and distant recurrence was recognized in other patients. We foresee this novel approach to have significant clinical potential for lower rectal cancer patients with ISR.