title: LETM1 overexpression is correlated with the clinical features and survival outcome of breast cancer.
abstract: BACKGROUND
  Leucine zipper/EF hand-containing transmembrane-1 (LETM1) is a mitochondrial inner membrane protein that was first identified in Wolf-Hirschhorn syndrome. However, high-level expression of LETM1 has been correlated with multiple human malignancies, suggesting roles in carcinogenesis and tumor progression. This study is aimed to explore the clinicopathological characteristics and prognostic value of LETM1 overexpression in breast cancer.
  
  
  METHODS
  Immunohistochemical (IHC) staining, and immunofluorescence (IF) were performed to examine LETM1 expression in breast cancer cell line/tissues compared with adjacent normal tissues. Statistical analysis was applied to evaluate the correlation between LETM1 overexpression and the clinicopathological features of breast cancer. Survival rates were calculated using the Kaplan-Meier method, and the relationship between prognostic factors and patient survival was analyzed using the Cox proportional hazard models.
  
  
  RESULTS
  LETM1 protein showed cytoplasmic staining pattern in breast cancer. The strongly positive rate of LETM1 protein was 61.6% (98/159) in breast cancer, which was significantly higher than in DCIS (29.7%, 11/37), hyperplasia (16.7%, 3/18) and adjacent normal breast tissues (15.9%, 7/44). High-level expression of LETM1 protein was correlated with lymph node metastasis, poor differentiation, late clinical stage, disease-free survival (DFS) and overall survival (OS) rates in breast cancer. Moreover, multivariate analysis suggested that LETM1 emerged as a significant independent prognostic factor along with clinical stage of patients with breast cancer.
  
  
  CONCLUSIONS
  LETM1 plays an important role in the progression of breast cancer. High level expression of LETM1 is an independent poor prognostic factor of breast cancer.
authors.affiliation: Key Laboratory Nature Resources of Changbai Mountain & Functional Molecules, Ministry Education, Yanbian University Yanji 133002, Jilin, China ; Department of Pathology & Cancer Research Center, Yanbian University Medical College Yanji 133002, Jilin, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Li
authors.affiliation: Department of Pathology & Cancer Research Center, Yanbian University Medical College Yanji 133002, Jilin, China.
authors.forename: Yahui
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Department of Pathology & Cancer Research Center, Yanbian University Medical College Yanji 133002, Jilin, China.
authors.forename: Chouhui
authors.initials: C
authors.lastname: Xuan
authors.affiliation: Key Laboratory Nature Resources of Changbai Mountain & Functional Molecules, Ministry Education, Yanbian University Yanji 133002, Jilin, China ; Department of Pathology & Cancer Research Center, Yanbian University Medical College Yanji 133002, Jilin, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Key Laboratory Nature Resources of Changbai Mountain & Functional Molecules, Ministry Education, Yanbian University Yanji 133002, Jilin, China ; Department of Oncology, Yanbian University Hospital Yanji 133002, Jilin, China.
authors.forename: Longzhen
authors.initials: L
authors.lastname: Piao
authors.affiliation: Key Laboratory Nature Resources of Changbai Mountain & Functional Molecules, Ministry Education, Yanbian University Yanji 133002, Jilin, China ; Department of Pathology & Cancer Research Center, Yanbian University Medical College Yanji 133002, Jilin, China.
authors.forename: Shuangping
authors.initials: S
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000096:biosynthesis*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D053208:Kaplan-Meier Estimate; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis*; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins; C488528:LETM1 protein, human; D008565:Membrane Proteins
keywords: LETM1; breast cancer; immunohistochemistry