Abstract 5662: <i>PDCD1</i> and <i>CD48</i> significantly impact cancer recurrence and survival in pediatric acute lymphoblastic leukemia
Authors: Shatha Fawaz Alotaibi, Lames Abuhadi, Noura Alolyani, Moureq R. Alotaibi, Ali R. Alhoshani, Homood As Sobeai
Journal: Cancer Research (2024)

Abstract Introduction: Immune checkpoints (ICPs) play a critical role in modulating the immune response, maintaining self-tolerance, and preventing excessive immune system activation. Dysregulation of immune checkpoints has been implicated in cancer progression and treatment resistance. In this study, we aimed to screen for dysregulated immune checkpoint genes that might be associated with cancer recurrence in pediatric acute lymphoblastic leukemia (ALL) following a course of cancer treatment. We hypothesized that certain ICPs would be significantly dysregulated in relapsed ALL patients, potentially providing insights into the underlying mechanisms driving therapy resistance and disease recurrence. Methods: 51 ICP genomic data (gene expression, copy number alterations (CNAs), and mutation) of133 patients with relapse information [relapse-free (n=29) and relapsed (n=104)] extracted from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) were examined in the study. Patient’s t-test (p-value &amp;lt; 0.05) was used to identify significant genetic factors between relapse-free and relapsed patients. Free and overall survival analyses were performed using log-rank test (p-value &amp;lt; 0.05) based on patient gene expression profiles. Results: Among the 51 genes examined, PDCD1, PVR, CD70, and CD48 were significantly upregulated in relapsed patients compared with relapse-free patients (P &amp;lt; 0.05). No significant CNAs nor mutations were detected in these four genes. Patients with high expression profiles of PDCD1 and CD48 at diagnosis were 1.71 and 1.47 more likely to relapse compared to patients with low expression profiles, respectively (P &amp;lt; 0.05). Furthermore, the upregulation of PDCD1 (P= 0.0004, HR= 1.972) and CD48 (P= 0.0344, HR= 1.533) demonstrated significantly increased mortality rates in patients following treatment, as indicated by overall survival analyses. Conclusion: The upregulation of PDCD1 and CD48 was significantly associated with relapse and survival of ALL patients. Promisingly, these two ICPs can potentially be used as prognostic biomarkers for relapse risk and rationale for alternative therapeutic strategies. Our study suggests that targeting PDCD1 and CD48 might be beneficial in enhancing the treatment efficiency and thereby reducing the recurrence risk. The study was funded by the Deputyship for Research and Innovation, Ministry of Education, Saudi Arabia (DRI-KSU-1273). Citation Format: Shatha Fawaz Alotaibi, Lames Abuhadi, Noura Alolyani, Moureq R. Alotaibi, Ali R. Alhoshani, Homood As Sobeai. PDCD1 and CD48 significantly impact cancer recurrence and survival in pediatric acute lymphoblastic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5662.