"GLI1 Subcellular Localization and Overexpression as Prognostic Factors for Disease-Free Survival in Colorectal Carcinoma"

Abstract

Purpose: Glioma-associated oncogene homolog-1 (GLI1) is amplified in human glioblastoma, and there is growing evidence suggesting its significant role in tumor development and metastasis. Our aim was to investigate the role of the GLI-1 gene in the progression of colorectal cancer (CRC) and its correlation with various clinicopathological features. Additionally, we examined the impact of the GLI-1 gene and other factors on the prognosis of CRC.

Methods: We analyzed a total of 98 confirmed CRC cases and adjacent normal tissue controls. Patients suspected of having colon cancer underwent a colonoscopy and targeted biopsy, while those with rectal cancer underwent CT scans and MRI. GLI1 expression was detected using real-time PCR assay, Western blotting, and immunohistochemistry.

Results: The GLI1 gene was observed to be overexpressed in tumor tissues at both the protein and mRNA levels (p < 0.05). In addition, GLI1 overexpression was significantly associated with various factors such as tumor invasion (T3/T4), presence of lymph nodes, lymph node metastasis (LNM), stage (III/IV), tumor site (colon), tumor size (≥ 3 cm), localization (nucleocytoplasmic), strong staining intensity and recurrence (p < 0.05). The results of survival analysis showed that the patients with overexpression of GLI1 had a significantly lower DFS rate which was 21 months compared to those with normal expression who had 31 months (p < 0.05). Moreover, individuals with early onset disease (15 months) were more likely to have cytoplasmic localization of the GLI1 gene as opposed to nucleo-cytoplasmic localization of GLI1 which presented late-onset disease( 23 months) (p < 0.05). Finally, Stage and PNI (p < 0.05) were found to independently affect outcomes of CRC according to Cox regression analysis.

Conclusion: High expression of GLI-1 in CRC is associated with adverse pathology and poor prognosis for patients. The correlation between cytoplasmic localization of GLI-1 and reduced disease-free survival holds potential for guiding prognosis and treatment. Further research is needed to develop strategies targeting GLI-1 for improved outcomes.

Keywords: CRC; Disease-free survival; Immunohistochemistry; Real-time PCR; Western blotting.