Genetic variants in NKG2D axis and susceptibility to Epstein-Barr virus-induced nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a rare epithelial carcinoma arising from the nasopharyngeal region. The pathogenesis of NPC is linked to Epstein-Barr virus (EBV) infection, although genetics and lifestyle factors appears to be also implicated. NKG2D is an immunoreceptor expressed by NK and T-cell subsets that recognizes MICA protein and other ligands on tumor cells. NKG2D interaction with MICA plays a role in the immunosurveillance to viruses and cancer. METHODS: We investigated potential associations between functional polymorphisms in NKG2D and MICA genes with NPC susceptibility. We conducted a case-control study including 255 Vietnamese patients with EBV + non-differentiated NPC and 220 healthy controls. RESULTS: We observed a significant association between the LNK/LNK genotype of rs1049174 (a variant associated with lower NKG2D receptor expression and reduced NK cell cytotoxicity) and increased susceptibility to NPC (adjusted OR = 1.66, 95% CI 1.07-2.59; p = 0.024). Similarly, the AA genotype of MICA rs2596542 was significantly associated with NPC (adjusted OR = 2.12; 95% CI 1.22-3.81; p = 0.009). In addition, tumor specimens of NPC patients with the AA genotype displayed a higher expression level of MICA proteins and showed higher EBV titers compared with tumor tissues from patients with the GG or GA genotypes. Higher EBV copy numbers were also observed in tumors with the A allele of MICA rs1051792 (also known as MICA-129 Met/Val) compared with those with the G allele; however, MICA rs1051792 variants were not associated with NPC susceptibility. These results suggest that genetic variants in components of the NKG2D axis may influence the individual susceptibility to EBV-induced NPC.

A systematic review finds underreporting of ethics approval, informed consent, and incentives in clinical trials.

OBJECTIVES: In this study, we aim to review researchers' reporting practices of the ethics statement, financial incentives, and local ethical committees' profile in their clinical trials. STUDY DESIGN AND SETTING: A systematic search was done through top-ranked 50 medical journals (Scimago Ranking) to retrieve 2,000 latest publications. Only primary clinical trials were included with no restriction to language or participants. RESULTS: Among the 927 included trials, 14 trials (1.5%) did not report an ethical statement and two-third (63%) did not completely report the investigated components (Institutional Review eBoard approval, Helsinki Declaration, and informed consent). Moreover, 21 trials (2.26%) reported motivational incentives with the method and amount of payment for participants. Of them, 15 trials offered monetary incentives to participants in different forms. In the remaining six trials, the incentives were mainly medical benefits. Only one trial reported the profile or quality of local Institutional Review Board. CONCLUSION: A potential gap in the reporting practices of ethics statement and financial incentives was addressed in this review. Authors are urged to fully report all ethical components related to their study, including incentives and compensations plan. Medical journals are also recommended to implement further publication requirements concerning ethics reporting.

The simultaneous inhibition of the mTOR and MAPK pathways with Gnetin-C induces apoptosis in acute myeloid leukemia.

Acute myelogenous leukemia (AML) is a clinically heterogeneous disease that is frequently associated with relapse and a poor prognosis. Among the various subtypes, AML with the monosomal karyotype (AML-MK) has an extremely unfavorable prognosis. We performed screening to identify antitumor compounds that are capable of inducing apoptosis in primary leukemia cells harboring the AML-MK karyotype and identified a naturally occurring stilbene, Gnetin-C, with potent anti-tumor activities against AML cells from patients with various cytogenetic abnormalities, including patients with the AML-MK karyotype. Gnetin-C simultaneously inhibits the ERK1/2 and the AKT/mTOR pathways, two signals that are essential for the survival of leukemia cells. A combination of Gnetin-C with low doses of chemotherapeutic drugs led to synergistic anti-tumor effects against AML cells. In an immunodeficient mouse model of human leukemia, Gnetin-C attenuated the formation of leukemia, depleted leukemia cells and improved survival. These findings suggest that Gnetin-C has antitumor activities in AML and supports the therapeutic potential of blocking two different pathways in AML.

The Repeated Administration of Resveratrol Has Measurable Effects on Circulating T-Cell Subsets in Humans.

Preclinical studies have shown that resveratrol exerts immunomodulatory effects with potential clinical value in the amelioration of autoimmune disorders and cancer prevention; however, little is known about the in vivo effects of this naturally occurring polyphenol on human immune cells. We assessed the effects of repeated doses of resveratrol (1000 mg/day for 28 days) on circulating immune cells in healthy Japanese individuals. Resveratrol was safe and well tolerated and was associated with significant increases in the numbers of circulating γδ T cells and regulatory T cells and resulted in small, yet significant, decreases in the plasma levels of the proinflammatory cytokines TNF-α and MCP-1 and a significant increase in the plasma antioxidant activity compared with the corresponding antioxidant baseline activity and with that in four control individuals. In in vitro studies, resveratrol significantly improved the growth of γδ T cells and regulatory T cells. These findings demonstrate that resveratrol has some clear biological effects on human circulating immune cells. Further studies are necessary to interpret the long-term immunological changes associated with resveratrol treatment.

Resveratrol selectively induces apoptosis in malignant cells with the JAK2V617F mutation by inhibiting the JAK2 pathway.

SCOPE: Resveratrol is a natural occurring polyphenol with several health promoting activities, including anticancer potential. Here, we analyzed the cytotoxic effects of resveratrol against malignant cells characterized by aberrant activation of the Janus kinase 2 (JAK2). METHODS AND RESULTS: Cell-cycle analysis, proliferation, apoptosis, and Western blotting assays were performed to study the effect of resveratrol on malignant cells exhibiting an excessive activation of the JAK2 pathway secondary to the JAK2(V617F) mutation. Resveratrol inhibited proliferation and induced apoptosis in JAK2(V617F) mutant tumor cells and its selectivity was 1.5-6.9 times greater than that observed in other tumor cells without the JAK2(V617F) mutation. In addition, resveratrol inhibited the phosphorylation of JAK1, JAK2, and Tyk2 and their downstream mediators, including STAT3 and STAT5. In primary cultures, resveratrol treatment inhibited erythroid progenitor colony formation in blood samples obtained from JAK2(V617F) polycythemia vera patients. Moreover, resveratrol synergized with the selective JAK2 inhibitor ruxolitinib, eliminating tumor cells with the JAK2 mutation. CONCLUSION: Resveratrol may have therapeutic potential against myeloproliferative neoplasms associated with the aberrant activation of the JAK2 pathway.

Paraptosis cell death induction by the thiamine analog benfotiamine in leukemia cells.

Benfotiamine is a synthetic thiamine analogue that stimulates transketolase, a cellular enzyme essential for glucose metabolism. Currently, benfotiamine is used to treat diabetic neuropathy. We recently reported that oral benfotiamine induced a temporary but remarkable recovery from acute myeloid leukemia in an elderly patient who was ineligible for standard chemotherapy due to dementia and renal failure. In the present study we present evidences that benfotiamine possess antitumor activity against leukemia cells. In a panel of nine myeloid leukemia cell lines benfotiamine impaired the viability of HL-60, NB4, K562 and KG1 cells and also inhibited the growing of primary leukemic blasts. The antitumor activity of benfotiamine is not mediated by apoptosis, necrosis or autophagy, but rather occurs though paraptosis cell death induction. Mechanistic studies revealed that benfotiamine inhibited the activity of constitutively active ERK1/2 and concomitantly increased the phosphorylation of JNK1/2 kinase in leukemic cells. In addition, benfotiamine induced the down regulation of the cell cycle regulator CDK3 which resulted in G1 cell cycle arrest in the sensitive leukemic cells. Moreover, combination index studies showed that benfotiamine enhanced the antiproliferative activities of cytarabine against leukemia cells. These findings suggest that benfotiamine has antitumor therapeutic potential.

Resveratrol prevents EBV transformation and inhibits the outgrowth of EBV-immortalized human B cells.

BACKGROUND: Epstein Barr virus-associated lymphoproliferative disease is an increasing complication in patients with immunosuppressive conditions. Although the current therapies for this disorder are effective, they are also associated with significant toxicity. In an attempt to identify newer therapeutic agents, this study investigated the effects of Resveratrol, a naturally occurring polyphenolic compound, on the EBV transformation of human B cells. METHODOLOGY/PRINCIPAL FINDINGS: This study demonstrates that resveratrol prevents EBV transformation in human B cells. These effects are mediated by specific cytotoxic activities of resveratrol against EBV-infected B cells that are associated with the downregulation of the anti-apoptotic proteins Mcl-1 and survivin. This occurs as a consequence of the inhibition of EBV-induced NFκB and STAT-3 signaling pathways and a resveratrol-induced decrease in the expression of the oncogenic viral product LMP1 in EBV-infected B cells. In addition, resveratrol decreased the expression of miR-155 and miR-34a in EBV-infected B cells, blocked the expression of the anti-apoptotic viral gene BHRF1, and thus interrupted events that are critical for EBV transformation and the survival of EBV-transformed cells. CONCLUSIONS/SIGNIFICANCE: These results suggest that resveratrol may therefore be a potentially effective therapeutic alternative for preventing EBV-associated lymphoproliferative diseases in immune compromised patients.