Expression of Oct4 Protein in Astrocytic Tumours-Histopathologic and Immunohistochemical Study

• Main Authors: Menar M Al-Sayed Ayoub, Samar Abdel-Moneim Al-Sheikh, Lubna Omar Al-Farouk Abdel-Salam, Engy Samir Mohamed Abdel-Moneim Al-Hariry
• Format: Article
• Language: English
• Published: JCDR Research and Publications Private Limited 2018-11-01
• Series: Journal of Clinical and Diagnostic Research
• Subjects: astrocytoma; normal brain tissue; oct4; stem cells
• Online Access: https://jcdr.net/articles/PDF/12276/35035_CE[Ra1]_F(SL)_PF1(PG_SL)_PFA(HJ_SL)_PN(SL).pdf
• ISSN: 2249-782X; 0973-709X

Introduction: The majority of gliomas in adults are resistant to therapy. Therapy resistance has been attributed to the presence of cancer stem cells (CSCs). Oct4 is a transcription factor required for maintaining the pleuripotency and self-renewal of CSCs. It was found to be highly expressed in astrocytomas and other tumours. Aim: Assessment of immunohistochemical expression of Oct4 protein, being a target antigen for cancer immunotherapy of astrocytic tumours, and correlation between Oct4 expression and the grades of astrocytoma. Materials and Methods: In this retrospective cross sectional study, 66 paraffin embedded biopsies of astrocytomas were collected including; 12 cases of grade I, 19 cases of grade II, 15 cases of grade III and 20 cases of grade IV. All the cases were studied immunohistochemically using anti-Oct4 protein antibody. Chi-square test or Fisher’s exact test was used to examine the relation between qualitative variables. All tests were two-tailed. Only a p-value <0.05 was considered significant. Results: Oct4 was expressed in 30 cases. The higher the grade of astrocytoma, the more was the expression (p-value=0.006) and the percentage of positive tumour cells (p-value=0.039). The expression was both nuclear and cytoplasmic. The intensity of expression was variable within the same tumour. Oct4 was not expressed in normal brain tissue. Conclusion: Oct4 is a stem cell marker that is involved in the development of CSCs, and accordingly, the development of many tumours including astrocytomas.