Cell Cycle Changes, DNA Ploidy, and PTTG1 Gene Expression in HTLV-1 Patients.

Human T-cell lymphotropic virus type-1 (HTLV-1) is a pathogenic retrovirus that is associated with adult T-cell leukemia/lymphoma (ATL). Genetic instability is the hallmark of ATL. Cell cycle progression is needed for virus particle reproduction. HTLV-1 encoded Tax protein ultimately disrupts the mitotic spindle checkpoint, leading to incorrect chromosome segregation, resulting in aneuploidy. Cell cycle abnormalities have been described in T cells transfected with HTLV-1 virus in vitro, but not in HTLV-1 asymptomatic carriers. PTTG1 and HTLV-1 viral protein Tax exhibit a cooperative transforming activity. Overexpressed PTTG1 results in chromosome instability and aneuploidy, which has been suggested as a mechanism underlying PTTG1 transforming activity. Here we aimed to investigate cell cycle, DNA ploidy and PTTG1 mRNA expression in CD4+ and CD8+ T cells in healthy subjects (HS), HTLV-1 asymptomatic carriers and ATL patients. We have identified that HTLV-1 asymptomatic carriers have shown DNA aneuploidy and cell cycle arrest at cell cycle phase G0/G1 in CD4+ T cells. CD8+ T cells of HTLV-1 asymptomatic carriers also demonstrated DNA aneuploidy but without alteration in cell cycle. In ATL, CD4+ and CD8+ T cells present a higher number of cells in cell cycle S-phase and PTTG1 overexpression. These studies provide insight into malignant transformation of HTLV-1 asymptomatic carriers to ATL patients.

Treatment outcomes of adult Burkitt lymphoma: results with a modified LMB protocol in Brazil and feasibility of outpatient administration.

While Burkitt lymphoma (BL) is an aggressive subtype of non-Hodgkin lymphoma more prevalent in tropical areas, few studies on BL have been conducted in Latin America. Here, we evaluate the clinical presentation and outcomes of an adapted LMB regimen for adults with sporadic BL. We retrospectively evaluated hospital records from University of São Paulo (USP) between 1999 and 2017. Thirty-six patients were included, the median age was 33.5 years and 69% (25) were male. Most patients presented advanced stage disease (81%), 8% had CNS disease, and the majority belonged to LMB group B (75% (27)). Three patients died during the induction phase, and the remaining patients (33) achieved complete response. There was one relapse over a median follow-up of 6 years. Overall survival estimated at 5 years was 89%. We conclude that an adapted LMB protocol is safe and feasible in Brazil.