Epstein–Barr virus, a ubiquitous human herpesvirus, can induce both lytic and latent infections that result in a variety of human diseases, including lymphoproliferative disorders. The oncogenic potential of Epstein–Barr virus is related to its ability to infect and transform B lymphocytes into continuously proliferating lymphoblastoid cells. However, Epstein–Barr virus has also been implicated in the development of T/natural killer cell lymphoproliferative diseases. Epstein–Barr virus encodes a series of products that mimic several growth, transcription and anti-apoptotic factors, thus usurping control of pathways that regulate diverse homeostatic cellular functions and the microenvironment. However, the exact mechanism by which Epstein–Barr virus promotes oncogenesis and inflammatory lesion development remains unclear. Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases often have overlapping clinical symptoms as well as histologic and immunophenotypic features because both lymphoid cell types derive from a common precursor. Accurate classification of Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases is a prerequisite for appropriate clinical management. Currently, the treatment of most T/natural killer cell lymphoproliferative diseases is less than satisfactory. Novel and targeted therapies are strongly required to satisfy clinical demands. This review describes our current knowledge of the genetics, oncogenesis, biology, diagnosis and treatment of Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases.

13-Methyltetradecanoic acid (13-MTD), a saturated branched-chain fatty acid purified from soy fermentation products, induces apoptosis in human cancer cells. We investigated the inhibitory effects and mechanism of action of 13-MTD on T-cell non-Hodgkin’s lymphoma (T-NHL) cell lines both in vitro and in vivo. Growth inhibition in response to 13-MTD was evaluated by the cell counting kit-8 (CCK-8) assay in three T-NHL cell lines (Jurkat, Hut78, EL4 cells). Flow cytometry analyses were used to monitor the cell cycle and apoptosis. Proteins involved in 13-MTD-induced apoptosis were examined in Jurkat cells by western blotting. We found that 13-MTD inhibited proliferation and induced the apoptosis of T-NHL cell lines. 13-MTD treatment also induced a concentration-dependent arrest of Jurkat cells in the G1-phase. During 13-MTD-induced apoptosis in Jurkat cells, the cleavage of caspase-3 and poly ADP-ribose polymerase (PARP, a caspase enzymolysis product) were detected after incubation for 2 h, and increased after extending the incubation time. However, there was no change in the expression of Bcl-2 or c-myc proteins. The appearance of apoptotic Jurkat cells was accompanied by the inhibition of AKT and nuclear factor-kappa B (NF-κB) phosphorylation. In addition, 13-MTD could also effectively inhibit the growth of T-NHL tumors in vivo in a xenograft model. The tumor inhibition rate in the experimental group was 40%. These data indicate that 13-MTD inhibits proliferation and induces apoptosis through the down-regulation of AKT phosphorylation followed by caspase activation, which may provide a new approach for treating T-cell lymphomas.

Key Points Question Is there characteristic microbiota in nasopharyngeal carcinoma (NPC) tissues and, if so, is it associated with prognosis? Findings In this multicenter cohort study including 802 patients with NPC, we confirmed the existence of microbiota within NPC tissues, which mainly originated from the nasopharynx. Intratumoral bacterial load was associated with poor survival in patients with NPC and was negatively associated with T-lymphocyte infiltration. Meaning The results suggest that the intratumoral bacterial load may be a reliable prognostic indicator for patients with NPC.

Purpose: Deregulation of microRNA (miRNA) has been extensively investigated in both Hodgkin and non-Hodgkin lymphomas (NHL); however, little is known about the roles of miRNAs in T-cell lymphoblastic lymphoma (T-LBL). The aim of the present study was to investigate the potential roles of miR-374b in the development and treatment of T-LBL.Experimental Design: MiRCURY LNA array was used to generate a miRNA-expressing profile. Real-time quantitative PCR and immunohistochemistry (IHC) were applied to detect the expression of miR-374b, AKT1, and Wnt16 in T-LBL samples. The dual-luciferase reporter assay was conducted to confirm target associations of miR-374b. The tumor-suppressive effect of miR374b was determined by both in vitro and in vivo studies.Results: The expression of 380 miRNAs was evaluated in five human T-LBL tissues and five infantile thymus samples by micro-RNA microarrays. Downregulation of miR-374b was frequently detected in primary T-LBL tissues, which was significantly associated with worse overall survival and increased risk of recurrence of the 58 patients enrolled in this study. miR-374b suppressed T-LBL cell proliferation in vitro and in vivo and sensitized cells to serum starvation-and chemotherapeutic agent-induced apoptosis. Furthermore, we characterized two AKT pathway-associated molecules, AKT1 and Wnt16, as direct targets of miR-374b. Consistently, in T-LBL patient tissues, AKT1 and Wnt16 expression was inversely correlated with miR-374b levels, and was an independent predictor of recurrence and survival.Conclusions: Our data highlight the molecular etiology and clinical significance of miR-374b in T-LBL. Targeting miR-374b may represent a new therapeutic strategy to improve therapy and survival for T-LBL patients.