Quantitative PCR Analysis of TSC2, ACTN4, CXCR4, and ATF1 Expression in HTLV-1-Associated Adult T-cell Leukemia/Lymphoma Compared to Healthy Controls

Abstract

Background: Adult T-cell leukemia/lymphoma (ATLL) is a hematologic malignancy associated with human T-cell lymphotropic virus type 1 (HTLV-1) infection. Gene expression changes play a role in its pathogenesis. Objectives: In this study, we examined the gene expression profiles of alpha-actinin-4 (ACTN4), Tuberous Sclerosis Complex 2 (TSC2), C-X-C chemokine receptor type 4 (CXCR4), and Activating Transcription Factor 1 (ATF1) in Iranian ATLL patients for the first time, contrasting the findings with those from healthy controls. Methods: This case-control study (2023 - 2024) included 20 male Iranian participants (10 ATLL patients and 10 healthy controls). From each participant, 6 ml of whole blood was collected. Samples from eligible participants were screened for HTLV-1 infection using enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). RNA was extracted and complementary DNA (cDNA) synthesis was performed. The expression of ACTN4, TSC2, CXCR4, ATF1, and viral HBZ genes was measured by Real-time PCR, using RPLP0 as the reference gene. Results: Expression of TSC2 and ACTN4 genes was significantly decreased in ATLL patients compared to healthy controls (TSC2: mean ± SD: 0.00003 ± 0.00004 vs. 0.00006 ± 0.00004, P < 0.05; ACTN4: 0.0129 ± 0.024 vs. 0.0207 ± 0.009, P < 0.05); CXCR4 and ATF1 expression levels were slightly increased but not significantly different between groups (CXCR4: 0.147 ± 0.154 vs. 0.139 ± 0.09, P > 0.05; ATF1: 0.0028 ± 0.0029 vs. 0.0015 ± 0.0009, P > 0.05). Conclusions: Dysregulation of target genes in ATLL patients suggests HTLV-1 involvement in disease progression by modulating host cellular pathways. Although CXCR4 and ATF1 showed non-significant upward trends, the observed downregulation of TSC2 and ACTN4 warrants further investigation in a larger sample size to clarify their potential roles in ATLL pathogenesis.