LAT1 Expression (lat1 + expression)

Distribution by Scientific Domains


Selected Abstracts


Expression of L-type amino acid transporter 1 (LAT1) in esophageal carcinoma

JOURNAL OF SURGICAL ONCOLOGY, Issue 4 2005
Hideaki Kobayashi MD
Abstract Background and Objectives It has been reported that amino acid transport systems play an important role in cell proliferation. Their activity is increased in malignant cells compared to benign cells. In this study, we investigated whether L-type amino acid transporter 1 (LAT1) is expressed in human non-cancerous esophageal mucosa and esophageal squamous cell carcinoma. We also examined whether LAT1 expression is correlated with histopathological features. Methods From January 1999 to December 2001, sections of formalin-fixed, paraffin-embedded tissue from 11 cases of early esophageal carcinoma (T1) and 19 cases of advanced esophageal carcinoma (T2, T3) were entered in the study. Histopathologically, all 30 cases were squamous cell carcinoma. Immunohistochemical staining was performed using rabbit anti-LAT1 IgG, with the standard avidin-streptavidin immuno-peroxidase method. Measurement was performed by means of computer-assisted image analysis. The ratio of cells with LAT1 expression in esophageal squamous cell carcinoma and non-cancerous esophageal mucosa was used for analysis in this study. Results Non-cancerous esophageal mucosa expressed LAT1 only in the basal layer of the esophageal wall. Esophageal squamous cell carcinoma expressed LAT1 throughout the tumor. LAT1 expression in esophageal squamous cell carcinoma was significantly higher than that in non-cancerous esophageal mucosa. LAT1 expression in esophageal squamous cell carcinoma increased as the depth of invasion progressed (T1,<,T2 (P,=,0.0477), T2,<,T3 (P,=,0.0415), T1,<,T3 (P,=,0.0044)), and as the tumor size increased. Also, high LAT1 expression was significantly associated with well-differentiated carcinoma. Conclusion These results suggest that LAT1 plays a significant role in cell proliferation, differentiation, and invasion in esophageal squamous cell carcinoma. J. Surg. Oncol. 2005;90:233,238. © 2005 Wiley-Liss, Inc. [source]


L-type amino-acid transporter 1 as a novel biomarker for high-grade malignancy in prostate cancer

PATHOLOGY INTERNATIONAL, Issue 1 2009
Takeshi Sakata
To find reliable biomarkers for high-grade malignancy, the relationship between immunohistochemical L-type amino-acid transporter 1 (LAT1) expression of biopsy samples, determined with the newly developed monoclonal antibody against human LAT1, and prognosis of patients with prostate cancer, was investigated. The intensity and score of immunohistochemical LAT1 expression of first biopsy samples were assessed using the modified Sinicrope et al. method and were found to be correlated with poor survival for the study group of 114 surgically treated patients as a whole (P = 0.0002 and 0.0270, respectively). LAT1 intensity further had a significant relationship (P = 0.0057) with prognosis in pathological T3 + T4 groups. Multivariate analysis indicated that the LAT1 intensity and score were more reliable prognostic markers, compared with the Gleason score and the Ki-67 labeling index. A relationship of the LAT1 intensity and score with prognosis could also be confirmed in 63 patients with inoperable cancer (P = 0.0070 and <0.0001, respectively). Similarly, significant differences in prognosis were confirmed in clinical T3 + T4 groups (P = 0.0091 and 0.0244, respectively). Moreover, the combination of LAT1 expression and Gleason score was found to have a more reliable correlation with prognosis. Thus, elevated LAT1 expression in prostate cancers is a novel independent biomarker of high-grade malignancy, which can be utilized together with the Gleason score, which is mainly dependent on cellular and structural atypia, to assess prognosis. [source]


Correlation of angiogenesis with 18F-FMT and 18F-FDG uptake in non-small cell lung cancer

CANCER SCIENCE, Issue 4 2009
Kyoichi Kaira
L-[3- 18F]-,-methyltyrosine (18F-FMT) is an amino-acid tracer for positron-emission tomography (PET). We have conducted a clinicopathologic study to elucidate the correlation of angiogenesis with 18F-FMT and 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) uptake in patients with non-small cell lung cancer (NSCLC). Thirty-seven NSCLC patients were enrolled in this study, and two PET studies with 18F-FMT and 18F-FDG were performed. Uptake of PET tracers was evaluated with standardized uptake value. Vascular endothelial growth factor (VEGF), CD31, CD34, L-type amino acid transporter 1 (LAT1) and Ki-67 labeling index of the resected tumors were analyzed by immunohistochemical staining, and correlated with the clinicopathologic variables and the uptake of PET tracers. The median VEGF rate was 45% (range, 10,78%). High expression was seen in 30 patients (81%, 30/37). VEGF expression was statistically associated with progressively growing microvessel count. VEGF showed a correlation with LAT1 expression (P = 0.04) and Ki-67 labeling index (P = 0.01). However, it showed no correlation with age, gender, disease stage, tumor size, and histology. Microvessel density (MVD) showed no correlation with any parameters. 18F-FMT and 18F-FDG uptake correlated significantly with VEGF (P < 0.0001, P = 0.026, respectively), whereas the correlation of 18F-FMT and VEGF was more meaningful. The present study demonstrated that the metabolic activity of primary tumors as evaluated by PET study with 18F-FMT and 18F-FDG is related to tumor angiogenesis and the proliferative activity in NSCLC. (Cancer Sci 2009; 100: 753,758) [source]