Search Results (203)

Classic Kaposi sarcoma (CKS) is a rare vascular neoplasm driven by infection with Kaposi sarcoma-associated herpesvirus (KSHV) and characterized by a heterogeneous geographic distribution. While the etiology of other Kaposi’s sarcoma (KS) variants is well established, the underlying mechanisms of CKS appear multifactorial, with several risk factors, among which advanced age and male sex are most significant. Due to the rarity of CKS and its often indolent clinical course, clinical trials are sparse, and current knowledge of therapeutic approaches remains limited. Most available clinical trials and practice guidelines focus on human immunodeficiency virus (HIV) -related Kaposi sarcoma. Therefore, specific recommendations for the classic form are restricted and rely on a low level of evidence, as categorized by the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines, making disease management more challenging. Current approaches to treating CKS include both local and systemic therapies, selected based on disease stage, patient comorbidities, and individual preferences. Systemic treatment options may include immunotherapy, chemotherapy, or antiangiogenic agents. This review summarizes current management strategies and highlights emerging therapeutic approaches for CKS. It aims to support clinicians in optimizing therapeutic decision-making, including the use of novel and investigational therapies. Although several novel therapies are currently under investigation in clinical trials, significant gaps remain. Therefore, further research is needed to improve disease management. Full article

Kaposi’s Sarcoma-associated herpesvirus (KSHV) has been etiologically linked to several human cancers, including Kaposi’s sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman’s disease (MCD). However, recent studies suggest that KSHV infection may also be associated with the development of other diseases or increased risks, such as KSHV inflammatory cytokine syndrome (KICS), diabetes, malaria, heart disease, and other cancers. In this review, we summarize these findings from clinical observations, epidemiological studies or laboratory research, though more studies are needed in these emerging areas. We believe that this work will enhance our understanding of the molecular mechanisms underlying KSHV pathogenesis and contribute to improving treatments for related human diseases. Full article

Persistent oncovirus infections account for 15–20% of the global cancer burden, driving multiple forms of human cancer. To maintain persistent infection and spread, oncoviruses drive alterations in host cell metabolism, immune signaling, and cell-to-cell communication throughout tumor microenvironments. Accumulating evidence has indicated that these alterations occur in conjunction with a range of organelle remodeling events that can differ between “dormant” viral latency and active lytic replication. Throughout each phase of infection, oncoviruses alter the morphology, composition, and function of organelles to promote cellular survival and proliferation, while periodically supporting viral replication. Here, we review oncovirus-driven organelle remodeling strategies across distinct infection states, including viral latency, reactivation from latency, and chronic active replication. We focus on the molecular mechanisms by which oncovirus-driven organelle remodeling promotes cellular transformation, impedes immune responses, and facilitates virion assembly and egress. We also draw parallels between remodeling strategies employed by oncogenic and oncomodulatory viruses, emphasizing broadly conserved mechanisms across cancer-associated infections. Lastly, we highlight how studies of oncovirus organelle remodeling are critical for discovering vulnerabilities in both oncogenic virus infection and viral oncogenesis, with therapeutic potential for multiple cancers. Full article

Kaposi’s Sarcoma-associated herpesvirus (KSHV) and Epstein–Barr virus (EBV) are oncogenic gammaherpesviruses with high prevalence in sub-Saharan Africa. Both viruses are typically acquired during childhood, establishing lifelong latency. While viral reactivation into the lytic cycle has been mainly studied in adult HIV-infected populations—and more recently in the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) co-infection—the dynamics of KSHV and EBV infection in children remain poorly understood. Here, we characterize pediatric patients (n = 175; median age 4.6 years; IQR 2.0–8.3) presenting with inflammatory conditions during the COVID-19 pandemic in South Africa (from July 2020 to February 2024). Including a healthy, non-inflammatory control group, we found widespread exposure to SARS-CoV-2 (70.9% seropositivity), with 72.6% of the children being seropositive for EBV and 19.4% for KSHV. There were no significant differences in seroprevalence between children with inflammatory conditions and healthy controls for any of these viruses, although SARS-CoV-2 antibody titers were significantly higher in the inflammatory group, while EBV immune responses were lower in children presenting with inflammation. Among the KSHV-seropositive children, no active viremia was detected (as determined by the absence of viral DNA in the peripheral blood). In contrast, 34.4% of EBV-seropositive children had detectable EBV viral load, with a modestly higher proportion in the inflammatory group. However, EBV viral load levels were comparable between children diagnosed with Multisystem Inflammatory Syndrome in Children (MIS-C), Kawasaki Disease (KD), and other inflammatory conditions. Logistic regression analyses revealed that increasing age was significantly associated with higher risk of SARS-CoV-2 and EBV seropositivity, but not KSHV. Notably, the risk of EBV DNA detection in the peripheral blood decreased with age. In summary, this study suggests effective immunological control of gammaherpesvirus infections in HIV-negative paediatric patients, even in the presence of inflammatory conditions that might otherwise trigger viral reactivation. Full article

Nucleic acid-based gene interfering and editing molecules, such as antisense oligonucleotides, ribozymes, small interfering RNAs (siRNAs), and CRISPR-Cas9-associated guide RNAs, are promising gene-targeting agents for therapeutic applications. Cancer’s heterogeneous and diverse nature demands gene-silencing technologies that are both specific and adaptable. RNase P ribozymes, called M1GS RNAs, are engineered constructs that link the catalytic M1 RNA from bacterial RNase P to a programmable guide sequence. This guide sequence directs the M1GS ribozyme to base-pair with a target RNA, inducing it to fold into a structure resembling pre-tRNA. Catalytic activity can be enhanced through in vitro selection strategies. In this review, we will discuss the application of M1GS ribozymes in targeting cancer-associated RNAs, focusing on the BCR-ABL transcript in leukemia, the internal ribosome entry site (IRES) of hepatitis C virus (HCV), and the replication and transcription activator (RTA) of Kaposi’s sarcoma-associated herpesvirus (KSHV). Together, these examples highlight the versatility of M1GS ribozymes across both viral and cellular oncogenic targets, underscoring their potential as a flexible synthetic biology platform for cancer therapy. Full article

Approximately 12% of all human cancers are caused by oncoviruses. Macrophage migration inhibitory factor (MIF) signaling activation has been found closely related to many cancer cell malignant behaviors and infectious disease progression. However, its role in virus-associated cancers or how oncoviruses may regulate MIF signaling activities remains largely unknown. In the current review, we summarize recent findings about the oncovirus activation of MIF signaling pathways, their functional roles in viral oncogenesis, and the development of MIF-targeted therapies. We also discuss future directions in this interesting field. Full article

Kaposi’s sarcoma (KS), an AIDS-defining illness, is caused by Kaposi’s sarcoma-associated herpesvirus (KSHV). A member of the human herpesvirus family, designated as human herpesvirus 8 (HHV-8), KSHV is also linked to other oncogenic manifestations such as primary effusion lymphoma (PEL). The current dearth of available compounds against KSHV necessitates development of effective antiviral treatments. As with other herpesviruses, KSHV can result in both lytic and latent infections. KSHV pathogenesis and the development of KS have been associated with the expression of KSHV genes and transcripts during viral infections. The transcriptome of KSHV heavily intersects with regulatory pathways and mechanisms involved with a multitude of diseases in humans. Circular RNAs (circRNAs) have recently been discovered to be expressed by KSHV. Research endeavors on KSHV circRNAs have focused on the roles they play throughout latent and lytic infection. Understanding the specific functions and interactions of KSHV circRNAs with the viral and host transcriptomes, as well as how they are identified and analyzed, will be the primary focus of this review. Overall, recent advances in KSHV circRNA research have deepened our understanding of the KSHV transcriptome and pathogenesis and are paving the way for the development of circRNA-based antiviral therapies. Full article

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi’s sarcoma (KS) and several lymphoproliferative diseases. As with all herpesviruses, KSHV replicates in a biphasic manner, with the establishment of a latent, persistent infection from which reactivation occurs, resulting in the completion of the temporal lytic replication cycle and production of infectious virions. Herein, we discuss the impact of KSHV lytic replication on the host cell nucleus and nuclear-related pathways. We highlight the dramatic remodelling of the nuclear architecture driven by the formation of viral replication and transcription centres (vRTCs), and the implications for sub-nuclear organelles, and how pathways involved in DNA damage, ribosomal biogenesis and epitranscriptomic regulation are disrupted or modified during KSHV replication. These changes foster an environment favourable for KSHV replication and may provide novel targets and strategies for therapeutic intervention. Full article

Kaposi’s sarcoma (KS) is a tumor that primarily affects the skin, caused by a multifactorial pathogenesis mediated through immune dysfunction, often leading to increased morbidity and mortality in Sub-Saharan Africa (SSA). Human herpesvirus-8, also known as Kaposi’s sarcoma-associated herpesvirus (KSHV), induces an infection that can facilitate the pathogenesis of KS and other conditions. All KSHV subtypes depend on the expression of specific markers, such as K1 proteins, which play critical roles in their life cycles. The infection is unevenly scattered worldwide, with individuals infected with human immunodeficiency virus (HIV) and pregnant women being among the most vulnerable groups. HIV infection and related effectors, such as TAT proteins, have substantial impacts on KSHV infectiousness, angiogenesis, various signaling pathways, and KS pathogenesis. Africa endures the heaviest burden of KS, which affects both men and women, sometimes from an early age. KS’s pathogenesis and underlying mechanisms remain unclear; this study aims to highlight the dynamics to be considered in managing and mitigating the burden of KS in SSA. In that region, certain infections are endemic and can cause intermediate health damage leading to KS tumorigenesis, highlighting the link between non-communicable and communicable diseases. Full article

Kaposi sarcoma (KS) is an intermediate-grade vascular tumour that has undergone major treatment and diagnostic breakthroughs following the discovery of Human herpesvirus 8 (HHV8). Whilst classically described in Eastern European populations, the endemic and epidemic forms of KS have facilitated its association with AIDS. This was led by the detection of HHV8 by PCR, and thereafter, immunohistochemically. This not only enabled the recognition and diagnosis of complex histopathological KS subtypes but also facilitated distinction from its mimickers, including acroangiodermatitis and pyogenic granuloma. Recent advances in the viral genomics of HHV8 have expanded the diagnostic landscape of KS clinically and molecularly. The latent phase of replication in the HHV8 lifecycle reveals numerous angiogenic and inflammatory factors. Novel therapies targeting these viral–human molecular interactions may prove useful. However, this is highly dependent on the clonal nature of KS. Conflicting research outcomes demonstrate varying viewpoints on the clonal (monoclonal/oligoclonal/polyclonal) nature of KS, heightening the tumoural versus inflammatory pseudoneoplastic controversy. Understanding the clinical context of KS is fundamental to understanding its clonality, and a dearth of this clinical information in recent studies appears to be the critical factor in determining the true clonal nature of KS. The current molecular landscape, histopathology, treatment options, and opinions on clonality are critically reviewed. Full article

Castleman disease and Kaposi sarcoma (KS) are both associated with infection by human herpesvirus 8 (HHV-8), also known as Kaposi’s sarcoma-associated herpesvirus (KSHV). This virus plays a critical role in the pathogenesis of both conditions, particularly in immunocompromised individuals, such as those with HIV/AIDS. Multicentric Castleman disease (MCD) generally presents with systemic inflammatory symptoms, lymphadenopathy, and organ dysfunction, while Kaposi sarcoma typically appears as vascular tumors on the skin, with occasional involvement of mucous membranes or internal organs. We present four clinical cases, with concurrent KS and MCD, treated with chemotherapy and rituximab, with a satisfactory response. We highlighted the essential role of prompt investigation of systemic or inflammatory manifestations (fever, vital parameter alterations such as palpitation, high breath frequency, edema, and kidney impairment) as underlined in our case series, which might underscore possible complications. Multiorgan failure, opportunistic infections, or rapid clinical deterioration might occur if the diagnosis is not adequately assessed. Therefore, this paper emphasizes the importance of timely diagnosis, as it enables the prompt initiation of appropriate antiviral, immunomodulatory, or oncologic therapies—interventions that can significantly improve outcomes and may be life-saving in advanced or aggressive disease presentations. Full article

Porcine lymphotropic herpesviruses -1, -2, and -3 (PLHV-1, PLHV-2, and PLHV-3) are gammaherpesviruses that are widespread in pigs. These viruses are closely related to the human pathogens Epstein–Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV), both of which are known to cause severe diseases in humans. To date, however, no definitive association has been established between PLHVs and any disease in pigs. With the growing interest in xenotransplantation as a means to address the shortage of human organs for transplantation, the safety of using pig-derived cells, tissues, and organs is under intense investigation. In preclinical trials involving pig-to-nonhuman primate xenotransplantation, another porcine herpesvirus—porcine cytomegalovirus, a porcine roseolovirus (PCMV/PRV)—was shown to be transmissible and significantly reduced the survival time of the xenotransplants. In the present study, we examined donor pigs and their respective baboon recipients, all of which were part of preclinical pig heart xenotransplantation studies, for the presence of PLHV. PLHV-1, PLHV-2, and PLHV-3 were detected in nearly all donor pigs; however, no evidence of PLHV transmission to the baboon recipients was observed. Full article

Herpesviruses are DNA viruses that evade the immune response and persist as lifelong infections. Human gamma-herpesviruses Epstein–Barr virus (EBV) and Kaposi’s sarcoma herpesvirus (KSHV) are oncogenic; they can lead to cancer. Oncogenic viruses are responsible for 10–15% of human cancer development, which can have poor prognoses. Non-coding RNAs (ncRNAs) are RNAs that regulate gene expression without encoding proteins, and are being studied for their roles in viral immune evasion, infection, and oncogenesis. ncRNAs are classified by their size, and include long non-coding RNAs, microRNAs, and circular RNAs. EBV and KSHV manipulate host ncRNAs, and encode their own ncRNAs, regulating host processes and immune responses. Viral ncRNAs regulate host functions by post-transcriptionally modifying host RNAs, and by serving as mimics of other host RNAs, promoting immune evasion. ncRNAs in gamma-herpesvirus infection are also important for tumorigenesis, as dampening immune responses via ncRNAs can upregulate pro-tumorigenic pathways. Emerging topics such as RNA modifications, target-directed miRNA degradation, competing endogenous RNA networks, and lncRNA/circRNA–miRNA interactions provide new insights into ncRNA functions. This review compares ncRNAs and the mechanisms of viral immune evasion in EBV and KSHV, while also expanding on recent developments in the roles of ncRNAs in immune evasion, viral infection, and oncogenesis. Full article

There has been extensive research on the KSHV/HHV8 virus, which has led to a better understanding of viral transmission, pathogenesis, viral-driven lymphoid proliferation, neoplastic transformation, and how we might combat these processes clinically. On an extensive review of the literature, only two true KSHV/HHV8-positive lymphoid neoplasms are described: primary effusion lymphoma (PEL), which can also present as solid or extracavitary primary effusion lymphoma (EC-PEL) and diffuse large B-cell lymphoma (DLBCL). Two lymphoproliferative disorders have also been described, and while they are not true monotypic neoplasms, these lesions can transform into neoplasms: KSHV/HHV8-positive germinotropic lymphoproliferative disorder (GLPD) and multicentric Castleman disease (MCD). This review provides a somewhat concise overview of information related to KSHV/HHV8-positive lymphoid neoplasms and pertinent associated lymphoproliferative lesions. Full article

Oncoviruses, such as Epstein–Barr virus (EBV), human papillomavirus (HPV), and Kaposi sarcoma-associated herpesvirus (KSHV), have been widely discussed for their oncogenic risk. Initially, the oral cavity was disregarded. In recent years, orientation has shifted to the importance of the oral cavity and cancer-related issues via Handbook 19 titled “Oral Cancer Prevention” by the International Agency for Research on Cancer, the WHO Global Oral Health Status Report 2022, and multiple other actions focused on reducing the oversight of this neglected area. Oncoviruses play a significant role in oral cavity malignancies by establishing persistent infections, evading host immune responses, and inducing cellular transformation through the disruption of normal regulatory pathways. Molecular biology and microbiome research have advanced our understanding of the complex interplay between oncoviruses and oral microbiota, demonstrating how coinfections and dysbiosis can enhance viral oncogenic potential. These findings improve the understanding of virus-induced oral cancers and support the development of novel diagnostic and therapeutic strategies. This narrative review focuses on the relationship between oncoviruses and the oral cavity by focusing on how a specific virus triggers tumorigenesis for each of the described viruses and how it affects oral cavity cancer development. Finally, we describe recent advances and future perspectives including vaccines and/or treatment. Full article