Infection with human herpesvirus type 8 and human T-cell leukaemia virus type 1 among individuals participating in a case-control study in Havana City, Cuba

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

Deguelin-induced blockade of PI3K/protein kinase B/MAP kinase signaling in zebrafish and breast cancer cell lines is mediated by down-regulation of fibroblast growth factor receptor 4 activity

Deguelin, a natural component derived from leguminous plants, has been used as pesticide in some regions. Accumulating evidence show that deguelin has promising chemopreventive and therapeutic activities against cancer cells. This study shows that low concentrations of deguelin can lead to significant delay in zebrafish embryonic development through growth inhibition and induction of apoptosis. Furthermore, we identified fibroblast growth factor receptor 4 (FGFR4) as the putative target of deguelin. The candidate was initially identified by a microarray approach and then validated through in vitro experiments using hormone‐responsive (MCF‐7) and nonresponsive (MDA‐MB‐231) human breast cancer cell lines. The results show that deguelin suppressed cell proliferation and induced apoptosis in both cancer cell lines, but not in Hs 578Bst cells, by blocking PI3K/AKT and mitogen‐activated protein kinases (MAPK) signaling. The FGFR4 mRNA and protein level also diminished in a dose‐dependent manner. Interestingly, we found that forced FGFR4 overexpression attenuated deguelin‐induced proliferative suppression and apoptotic cell death in both zebrafish and MCF‐7 cell lines, p‐AKT and p‐ERK levels were restored upon FGFR4 overexpression. Taken together, our results strongly suggest that deguelin inhibition of PI3K/AKT and MAPK signaling in zebrafish and breast cancer cell lines is partially mediated through down‐regulation of FGFR4 activity.

Human herpesvirus 8 seroprevalence among Tobago women and the role of sexual lifestyle behavior

Human herpesvirus 8 (HHV-8) infection is present in 22.9% of Tobago men. However, seroprevalence and modes of transmission of HHV-8 among Tobago women are not known. HHV-8 seropositivity rates in Tobago women were examined and compared rates to Tobago men of similar ages. To assess possible modes of transmission, sexual behavior among Tobago women was examined to determine its association with HHV-8 seropositivity. A cross-sectional study was conducted in 213 Tobago women, ages 18-65 years, who participated in the Tobago Cervical and Oral Cancer Screening Study. HHV-8 seropositivity was determined by a monoclonal immunofluorescence assay. Age-specific rates were compared to those previously observed in men. Logistic regression analyses were performed to determine the association between HHV-8 seropositivity and sexual behavior among the women. HHV-8 seroprevalence among Tobago women was 14.1% (95% CI, 10-19%), with no significant difference with men of similar age (P-value = 0.741). Age <or=17 years at first sexual intercourse was found to have a minimal significant association with HHV-8 seropositivity (OR = 2.51, 95% CI = 1.09-5.78) in women. HHV-8 age-specific rates were similar between genders. Sexual activity may not be a major contributor to HHV-8 infection among Tobago women.

Kaposi's sarcoma-associated herpesvirus: clinical, diagnostic, and epidemiological aspects

Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.

Transmission and disease association of Kaposi's sarcoma-associated herpesvirus: recent developments

PURPOSE OF REVIEW

Kaposi's sarcoma-associated herpesvirus or human herpesvirus 8, common in sub-Saharan Africa and around the Mediterranean Sea but rare in most other countries, is known to be transmitted in childhood within families in endemic regions, and through sexual contacts among high-risk groups in Western countries. Nevertheless recent developments on other modes of transmission of the virus have been made during the last years and are summarized in this review. Furthermore, recent published disease associations are discussed.

RECENT FINDINGS

The last year has seen research addressing the question of parenteral transmission, sexual transmission through heterosexual contact, transmission of Kaposi's sarcoma-associated herpesvirus-infected cells from organ donors to recipient, as well as the first suggestion that host genetic factors may facilitate infection in childhood. Additional clinical manifestations of infection with the virus such as primary pulmonary hypertension and germinotropic lymphoproliferative disorder have been identified.

SUMMARY

Evidence of Kaposi's sarcoma-associated herpesvirus transmission other than between homosexual adults and during childhood - namely transmission through heterosexual contact or injection drug use - is growing although these issues are still incompletely analysed and far away from being fully understood. Despite our increasing knowledge on transmission and disease associations of the virus, implications on the clinical management of associated diseases and public health have to be further evaluated in the coming years.