Pathology-Guided Transcriptomic Profiling of Prostate Cancer Identifies Grade-Associated Proliferative and Immune Signatures in a MENA Cohort.

BACKGROUND: Prostate cancer (PC) is a heterogeneous disease in which the histopathological grade does not always reflect underlying biological behavior. While transcriptomic studies have provided insight into tumor biology, grade-associated molecular changes remain incompletely defined, particularly in underrepresented populations such as those from the Middle East and North Africa (MENA) region. METHODS: In this study, we used a pathology-guided transcriptomic approach to examine gene expression patterns across PC grades in a MENA cohort. RNA sequencing was performed on formalin-fixed paraffin-embedded (FFPE) tissues, including benign prostatic hyperplasia (BPH, n = 7), low-grade tumors (Gleason 6-7 [3 + 4]; LG; n = 7), and high-grade tumors (Gleason 7 [4 + 3]-10; HG; n = 7). Differential expressions, pathway-level enrichment analyses and the estimation of immune cell composition were carried out, followed by comparison with publicly available datasets (TCGA-PRAD, n = 496), including LG tumors (n = 292) and HG tumors (n = 204), using the GEPIA2 and UALCAN platforms. Selected genes were further assessed using qRT-PCR in an independent set of samples (n = 21). Representative immunohistochemical images from the Human Protein Atlas were reviewed to provide descriptive protein-level context across tumor grades. RESULTS: Transcriptomic comparisons of tumor samples with benign controls identified a set of shared transcriptional changes present in both low- and high-grade disease. Among these, SLC29A2 and IL2RA showed consistent upregulation across tumor grades and similar expression trends in external datasets. Direct comparison between HG and LG tumors revealed distinct transcriptional profiles with patterns indicative of increased proliferative activity and altered immune-related signaling in higher-grade disease. Pathway-level analyses showed the enrichment of cell-cycle and metabolic gene signatures in HG tumors, whereas inflammatory and NF-κB-associated transcriptional signatures showed a comparatively reduced expression. Additional genes, including AAMDC, ASAH2, TNFRSF1B, NFKBIL1, and NFKBIZ, were associated with these grade-dependent differences. qRT-PCR findings were generally consistent with the RNA-seq results for selected targets. CONCLUSIONS: This study describes transcriptional patterns associated with the PC grade in a MENA cohort using a pathology-guided framework. The findings highlight candidate genes associated with tumor presence and grade progression and provide a foundation for further investigation in larger, well-annotated cohorts, particularly in populations that remain underrepresented in transcriptomic studies.