title: Overexpression of NDUFA4L2 is associated with poor prognosis in patients with colorectal cancer.
abstract: BACKGROUND
  NDUFA4L2 (NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 4-like 2, also called NADH-ubiquinone oxidoreductase MLRQ subunit homologue) was clearly enriched in the mitochondrial fraction under hypoxic conditions, and immunofluorescence showed a clear colocalization of NDUFA4L2 and cytochrome c in some tumour cells. However, little study has investigated its prognostic value in colorectal cancer (CRC).
  
  
  METHODS
  In our study, mRNA-NDUFA4L2 and protein expression were analysed in 150 cases of CRC and adjacent normal tissues using immunohistochemistry, semi-quantitative reverse transcriptase-polymerase chain reaction. The correlation between NDUFA4L2 expression and clinicopathological factors was evaluated by the Chi-square test. Overall survival of patients was analysed by the Kaplan-Meier method.
  
  
  RESULTS
  NDUFA4L2 overexpression was observed in 84% (126/150) of CRC tissues, but only in 24.7% (37/150) of adjacent normal tissues (P < 0.05). Semi-quantitative reverse transcriptase-polymerase chain reaction showed average mRNA expression levels to be 23.34 ± 1.356 and 4.34 ± 1.132 for CRC tissue and adjacent normal tissue (P < 0.05). Statistical analysis showed a significant correlation of NDUFA4L2 expression with histological grade, Dukes' stages, lymph node metastasis and liver metastasis. More importantly, multivariate analysis indicated that overexpression of NDUFA4L2 was an independent prognostic factor for CRC patients (P = 0.002). NDUFA4L2-negative patients had a higher tumour-free/overall survival rate than patients with high NDUFA4L2 expression (P = 0.001 and 0.002, respectively).
  
  
  CONCLUSIONS
  Our data suggest that NDUFA4L2 overexpression is associated with tumour progression and a poor prognosis in CRC patients.
authors.affiliation: University of South China, Hengyang, Hunan, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Lv
authors.affiliation: Department of Colorectal Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
authors.forename: Shao-Lin
authors.initials: SL
authors.lastname: Nie
authors.affiliation: Department of Colorectal Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
authors.forename: Ju-Mei
authors.initials: JM
authors.lastname: Zhou
authors.affiliation: University of South China, Hengyang, Hunan, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Colorectal Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
authors.forename: Ying-Bin
authors.initials: YB
authors.lastname: Hu
authors.affiliation: Department of Colorectal Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
authors.forename: Jia-Rui
authors.initials: JR
authors.lastname: Jiang
authors.affiliation: Department of Colorectal Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
authors.forename: Ni
authors.initials: N
authors.lastname: Li
authors.affiliation: Department of Colorectal Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
authors.forename: Jing-Shi
authors.initials: JS
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D042967:Electron Transport Complex I / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008113:Liver Neoplasms / Q000235:genetics* / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; C000625979:NDUFA4L2 protein, human; D012333:RNA, Messenger; D042967:Electron Transport Complex I
keywords: 
  NDUFA4L2
  ; biomarker; colorectal cancer; prognosis