Aya Kawamoto

Radiation induces epithelial-mesenchymal transition in colorectal cancer cells

Radiotherapy remains a major approach to adjuvant therapy for patients with advanced rectal cancer. Nevertheless, the effects of radiation on malignant processes have yet to be clarified. The aim of this study was to assess the biological effects of radiation on colorectal cancer (CRC) cells with special reference to epithelial-mesenchymal transition (EMT), a key developmental program often activated during cancer invasion and metastasis. We investigated the effect of radiation on two colorectal cancer cell lines, CaR1 and DLD1, assessing cell morphology, motility, migration and invasive ability. Expression of molecules associated with EMT was determined using RT-PCR, Western blotting, and immunofluorescence staining in control and irradiated cells. We also used real-time RT-PCR to examine the expression of molecules associated with EMT before and after chemoradiotherapy. Thus, we studied 26 rectal cancer patients who received preoperative chemoradiotherapy followed by radical surgery. In addition, we examined the relationship between disease recurrence and the expression of a number of proteins. Irradiation caused CRC cells to undergo phenotypic changes characteristic of EMT: spindle-cell shape, loss of polarity, intercellular separation and pseudopodia formation. Irradiation enhanced cell migration and invasiveness. In irradiated CRC cells, molecular changes consistent with EMT were observed. In clinical samples, we observed molecular changes consistent with EMT, and those changes were significantly enhanced in patients with recurring disease. These results indicate that irradiation induces an alteration to a malignant phenotype consistent with EMT in colorectal cancer cells.

Brain-derived neurotrophic factor/tropomyosin-related kinase B pathway in gastric cancer

Background:Brain-derived neutrophic factor (BDNF) is a member of the neutrophin family that is known to activate the high-affinity tropomyosin-related receptor kinase B (TrkB). This study aimed to clarify the clinical and biological significance of the BDNF/TrkB pathway in gastric cancer.Methods:We analysed BDNF and TrkB expression in gastric cancer samples by real-time reverse transcription PCR and immunohistochemistry. To investigate the biological role of BDNF/TrkB axis, recombinant human BDNF (rhBDNF) and the Trk antagonist K252a were used for in vitro and in vivo analysis.Results:The BDNF expression at the invasive front of primary tumours was significantly elevated compared with that in the tumour core and adjacent normal mucosa. Increased BDNF expression at the invasive front was significantly correlated with factors reflecting disease progression, and poor prognosis. Increased co-expression of the BDNF/TrkB axis was significantly correlated with poor prognosis. Gastric cancer cells expressed BDNF, and administration of rhBDNF promoted proliferation, migration, invasion, and inhibition of anoikis. These effects were generally inhibited by K252a. In an in vivo assay, BDNF(+)/TrkB(+) gastric cancer cells injected into nude mice established peritoneal dissemination, whereas K252a inhibited tumour growth.Conclusion:The BDNF/TrkB pathway might be deeply involved in gastric cancer disease progression.

Circulating form of human vascular adhesion protein-1 (VAP-1): decreased serum levels in progression of colorectal cancer and predictive marker of lymphatic and hepatic metastasis.

Vascular adhesion protein‐1 (VAP‐1) is an endothelial cell molecule that controls leukocyte tissue infiltration. Elevated serum soluble VAP‐1 (sVAP‐1) has been described in certain diseases with an inflammatory component. However, sVAP‐1 expression or function has not been studied in colorectal cancer. The present study determined the relationships between preoperative serum sVAP‐1 and clinicopathological features and prognosis in colorectal cancer.

Prognostic Significance of a Systemic Inflammatory Response in Patients Undergoing Multimodality Therapy for Advanced Colorectal Cancer

Objectives: The inflammation-based Glasgow Prognostic Score (GPS) is associated with outcome in a variety of cancers. This study investigated whether a modified GPS (mGPS) could predict survival in patients undergoing multimodality therapy for advanced colorectal cancer (CRC). Methods: We enrolled 245 patients with advanced CRC who received chemotherapy. The mGPS was recorded prior to first-line chemotherapy and to cytoreductive therapy including secondary surgery and/or radiofrequency ablation. The prognostic significance of the mGPS was analyzed using Kaplan-Meier, univariate, and multivariate analyses. Results: In patients who received chemotherapy alone (n = 163), the mGPS prior to chemotherapy was an independent prognostic indicator of survival [odds ratio (OR) 1.858; 95% confidence interval (CI) 1.213–2.846; p = 0.0044]. In patients who also underwent cytoreductive therapy (n = 82), the mGPS decreased after chemotherapy in 22 patients (27%) and increased in 5 (6%). In these patients, the mGPS prior to cytoreductive therapy was an independent prognostic indicator of survival (OR 3.412; 95% CI 1.198–9.720; p = 0.0216), but the mGPS prior to chemotherapy was not. Conclusions: The mGPS is an independent prognostic indicator of survival in patients undergoing multimodality therapy for advanced CRC, if recorded at a relevant time point.

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.

Elevated serum angiopoietin-like protein 2 correlates with the metastatic properties of colorectal cancer: a serum biomarker for early diagnosis and recurrence

Purpose: Angiopoietin-like protein 2 (ANGPTL2) is a mediator of chronic inflammation and inflammatory carcinogenesis. The biologic and clinical significance of ANGPTL2 remains unknown in human cancer. Therefore, we investigated the function of ANGPTL2 and evaluated its clinical significance in both primary tumors and matched sera in patients with colorectal cancer. Experimental Design: A colorectal cancer cell line was transfected with siRNA against ANGPTL2 for the assessment of its function. We examined ANGPTL2 expression in colorectal cancer tissues (n = 195) by immunohistochemistry. Finally, we screened serum ANGPTL2 levels from 32 colorectal cancers and 23 normal controls (NC), and validated these results in serum samples obtained from 195 colorectal cancers and 45 NCs by ELISA. Results: Knockdown of ANGPTL2 in vitro significantly inhibited cell proliferation, migration, and invasion, whereas it enhanced anoikis. ANGPTL2 was overexpressed in colorectal cancer tissues, and was significantly associated with advanced T stage, lymph node, and liver metastasis. Likewise, serum ANGPTL2 levels in colorectal cancers were significantly higher than NCs (P < 0.01), and allowed distinguishing of colorectal cancers from NCs with high accuracy (AUC = 0.837). The subsequent validation step confirmed that serum ANGPTL2 levels in colorectal cancers were significantly higher than in NCs (P < 0.0001), and had a high AUC value (0.885) for distinguishing colorectal cancers from NCs. High serum ANGPTL2 was significantly associated with advanced T stage, lymph node and liver metastasis, early relapse, and poor prognosis in colorectal cancers. Conclusion: Serum ANGPTL2 is a novel diagnostic and recurrence-predictive biomarker in patients with colorectal cancer. Clin Cancer Res; 20(23); 6175–86. ©2014 AACR.

Elevated Platelet Count as Predictor of Recurrence in Rectal Cancer Patients Undergoing Preoperative Chemoradiotherapy Followed by Surgery

The impact of systemic inflammatory response (SIR) on prognostic and predictive outcome in rectal cancer after neoadjuvant chemoradiotherapy (CRT) has not been fully investigated. This retrospective study enrolled 89 patients with locally advanced rectal cancer who underwent neoadjuvant CRT and for whom platelet (PLT) counts and SIR status [neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR)] were available. Both clinical values of PLT and SIR status in rectal cancer patients were investigated. Elevated PLT, NLR, PLR, and pathologic TNM stage III [ypN(+)] were associated with significantly poor overall survival (OS). Elevated PLT, NLR, and ypN(+) were shown to independently predict OS. Elevated PLT and ypN(+) significantly predicted poor disease-free survival (DFS). Elevated PLT was identified as the only independent predictor of DFS. PLT counts are a promising pre-CRT biomarker for predicting recurrence and poor prognosis in rectal cancer.

Loss of the metastasis suppressor gene KiSS1 is associated with lymph node metastasis and poor prognosis in human colorectal cancer

Cancer research is currently focused on blocking the metastatic process at its early steps. Some particularly attractive targets are metastasis suppressor genes, which control cancer cell dissemination. The aim of this study was to clarify the relationship between the expression of KiSS1, a metastasis suppressor gene, and disease progression in colorectal cancer patients. One-hundred and seventy-five patients who underwent surgery for colorectal cancer were enrolled in this study. We analyzed KiSS1 mRNA expression by real-time reverse transcription PCR in colorectal cancer tissue and paired adjacent normal mucosa. KiSS1 protein expression in early- and advanced-stage colorectal cancer samples was determined by immunohistochemical analysis. Decreased KiSS1 expression was significantly associated with lymph node metastasis and was an independent prognostic factor. Logistic regression analysis revealed that decreased KiSS1 expression was an independent risk factor for lymph node metastasis. Immunohistochemical analysis indicated that KiSS1 was highly expressed in the cell cytoplasm of early-stage colorectal cancer cells. The loss of KiSS1 appears to correlate with the progression of lymph node metastasis. An assessment of KiSS1 expression may assist in the accurate colorectal cancer diagnosis and may contribute to predict clinical outcomes.

Preoperative Assessment of Vascular Anatomy by Multidetector Computed Tomography Before Laparoscopic Colectomy for Transverse Colon Cancer: Report of a Case

Although the safety of laparoscopic surgery for colon cancer has been reported in many randomized controlled trials, concerns about the difficulty of surgery for transverse colon cancer has not been fully resolved, mainly because of the variation in the vascular anatomy of mesenteric vessels, which leads to difficulty in determining the optimal operative procedure and the extent of lymph node dissection. We present the case of a patient with transverse colon cancer who underwent laparoscopic surgery after preoperative assessment using a combination of endoscopic clipping and three-dimensional computed tomography angiography (3DCTA). A 68-year-old man was diagnosed with transverse colon cancer, and laparoscopic surgery has been planned. 3DCTA showed right-middle and left-middle colic arteries arising independently from the superior mesenteric artery. The relationship between the clip and vessels showed that the right-middle colic artery was the feeding artery of the tumor. Operative findings were consistent with 3DCTA findings, and transverse colectomy with lymph node dissection was successfully performed.

Clinical Correlations and Prognostic Relevance of Tissue Angiogenic Factors in Patients with Gastric Cancer

AIMS To evaluate the relationship between vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) levels in gastric cancer tissue and clinicopathological features and to determine whether these factors were correlated with survival. MATERIALS AND METHODS We analysed tissue samples from 58 patients with gastric cancer and used 24 normal gastric mucosae as controls. Tissue levels of VEGF and HGF were measured in tissue extracts by enzyme-linked immunosorbent assay. RESULTS HGF and VEGF levels were significantly higher in gastric cancer tissue than in matched normal gastric mucosa. VEGF levels were significantly increased in cancer tissue from cases involving lymphatic invasion. HGF levels were significantly increased according to the disease stage. Patients with high levels of VEGF or HGF showed significantly worse survival rates than patients with low levels. Using multivariate analysis, a high level of VEGF or HGF was an independent factor predicting poor survival. CONCLUSIONS Intratumoral levels of HGF and VEGF are an important prognostic determinant in gastric cancer. The current findings suggest that high concentrations of HGF and VEGF may induce aggressive tumour growth and metastasis.