Expression and significance of ALDH1A1, CD44, and OCT3/4 stem cell markers in glioblastoma tissues: an immunohistochemical study in Iraqi patients

Abstract

Cancers of the brain and nervous system are among the top five most common malignancies affecting both men and women in Iraq. Improvements in diagnostic techniques alongside increased medical awareness have facilitated earlier detection, thereby potentially improving patient outcomes. Cancer stem cells (CSCs) have been recognized as key players in the initiation, progression, and recurrence of tumors, including glioblastoma, the most aggressive form of brain cancer. These CSCs are characterized by specific markers that contribute to tumor growth, resistance to therapy, and poor prognosis. In this study, we collected 26 glioma tissue samples from Iraqi patients and classified them according to tumor grade. Using immunohistochemical methods, we investigated the expression patterns of three important CSC markers-ALDH1A1, CD44, and OCT3/4-across different glioblastoma grades. Our findings demonstrated a significant upregulation of cytoplasmic ALDH1A1 and membrane-bound CD44 in higher-grade tumors (grades III and IV), with P-values of less than 0.0174 and 0.0013, respectively. Additionally, nuclear OCT3/4 expression was markedly increased in these advanced tumor grades (P < 0.05), suggesting a role in tumor aggressiveness and stemness. These data provide compelling evidence that ALDH1A1, CD44, and OCT3/4 are not only involved in glioblastoma progression but may also serve as useful prognostic biomarkers. Furthermore, their elevated presence in more malignant tumors highlights their potential as targets for novel therapeutic interventions aimed at improving treatment efficacy and patient survival. This study thus contributes valuable insights into the molecular landscape of glioblastoma in the Iraqi population and sets a foundation for future research in targeted cancer therapy.