Overexpression of GLI1 and PTTG1 as Poor Prognostic Factor of Patients with Laryngeal Squamous Cell Carcinoma

Abstract

Background: Laryngeal squamous cell carcinoma (LSCC) constitutes about 98% of all laryngeal carcinomas with high mortality rates. The transcription factors Glioma-associated oncogene homolog1 (GLI1) and pituitary tumor transforming gene-1 (PTTG1) were associated with poor prognosis in several carcinomas. To date, no previous studies addressed the role of GLI1 in LSCC and limited studies have examined the role of PTTG1 in LSCC. Objectives: This study aims to evaluate the immunohistochemical (IHC) expression of GLI1 and PTTG1 in LSCC, to correlate their expression with clinicopathological features and patients' survival, and to assess the correlation between both proteins in LSCC. Materials and methods: GLI1 and PTTG1 expression was immunohistochemically examined in 60 LSCC specimens and 50 benign vocal fold polyps (control group). Results: GLI1and PTTG1 expression were significantly higher in LSCC than in the control group (p <0.0001 for each). Their expression was significantly higher in LSCC with larger size (p=0.001, p < 0.0001 respectively), higher grade (p <0.0001 for each), stage (p <0.0001 for each), lymph node metastasis (p<0.0001 for each), and lymphovascular emboli (p=0.003, p=0.004 respectively). High GLI1 and PTTG1 were the significant independent predictors for disease free survival (p=0.005, p=0.048 respectively). While higher tumor stage and higher GLI1 were the only significant indepen­dent prognostic factors for overall survival (p=0.049, p=0.041 respectively). Significant strong positive correlation was detected between GlI1 and PTTG1 in LSCC (p <0.0001). Conclusion: These results suggest that GLI1 and PTTG1 may contribute to LSCC pathogenesis. Targeting both proteins may improve the clinical management in the near future.

Keywords

• gli1 pttg1
• laryngeal squamous cell carcinoma survival