Expression and clinical role of small glutamine-rich tetratricopeptide repeat (TPR)-containing protein alpha (SGTA) as a novel cell cycle protein in NSCLC

J Cancer Res Clin Oncol. 2013 Sep;139(9):1539-49. doi: 10.1007/s00432-013-1474-5. Epub 2013 Jul 16.

Abstract

Purpose: A small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) is a 35 kDa protein involved in a number of biological processes. However, the role of SGTA in non-small-cell lung cancer (NSCLC) tumorigenesis has never been elucidated. The purpose of this study was to determine whether SGTA could serve as a biomarker for stratification and prediction of prognosis in NSCLC.

Methods: Small glutamine-rich tetratricopeptide repeat-containing protein alpha expression was evaluated by Western blot in 8 paired fresh lung cancer tissues and immunohistochemistry on 83 paraffin-embedded sections. The effect of SGTA was assessed by RNA interference in A549 cells. Serum starvation and refeeding, flow cytometry, CCK-8, and tunnel assays were performed.

Results: Small glutamine-rich tetratricopeptide repeat-containing protein alpha was highly expressed in NSCLC and significantly correlated with NSCLC histological differentiation, clinical stage, and Ki-67. Multivariate analysis indicated that SGTA was an independent prognostic factor for NSCLC patients' survival. The present investigation demonstrated that suppression of SGTA expression resulted in a significant decline of proliferation in A549 cells. Besides, SGTA could abolish the toxicity of cisplatin in A549 cells.

Conclusions: These findings suggested that SGTA might play an important role in promoting the tumorigenesis of NSCLC, and thus be a promising therapeutic target to prevent NSCLC progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / metabolism*
  • Adenocarcinoma / mortality
  • Adult
  • Aged
  • Apoptosis
  • Biomarkers, Tumor / metabolism*
  • Blotting, Western
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / mortality
  • Carcinoma, Squamous Cell / metabolism*
  • Carcinoma, Squamous Cell / mortality
  • Carrier Proteins / metabolism*
  • Cell Cycle*
  • Cell Proliferation
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Immunoenzyme Techniques
  • Lung / metabolism
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / mortality
  • Male
  • Middle Aged
  • Molecular Chaperones
  • Neoplasm Grading
  • Neoplasm Staging
  • Prognosis
  • Survival Rate
  • Tumor Cells, Cultured

Substances

  • Biomarkers, Tumor
  • Carrier Proteins
  • Molecular Chaperones
  • SGTA protein, human