New drug targets in Kaposi sarcoma

Electrochemotherapy in Kaposi's Sarcoma Patients: From the Gold Standard Strategy to Locally Advanced Cutaneous and Subcutaneous Lesions

Electrochemotherapy (ECT) is one of the newest therapeutic strategies employed as a medical procedure for skin neoplasms' treatment, especially for classic Kaposi's sarcoma (CKS). The aim of this study was to demonstrate ECT clinical response and the local control of CKS disease. The primary endpoint was to value the worth and efficacy of this local therapy in CKS skin lesions' treatment. In total, 19 CKS patients were enrolled, 14 males and 5 females with median age at diagnosis of 72. Complete response (CR) has been gained in 12 patients after first ECT attempt; meanwhile, 3 and 4 out of 19 patients obtained a partial response (PR), so they underwent a second and third ECT treatment, respectively. Clinical response was evaluated during the entire timeframe of the follow-up, which ranged between 3 months and 4 years with a median of 18 months. The control of CKS skin lesions still represents a challenge for surgeons and oncologists. Nevertheless, according to this and other authors' recent experiences, ECT could be considered the gold standard strategy for early-stage patients, but at the same time it could be considered as a valid option in controlling Kaposi's sarcoma locally advanced lesions.

Oncoviruses: How do they hijack their host and current treatment regimes

Viruses have the ability to modulate the cellular machinery of their host to ensure their survival. While humans encounter numerous viruses daily, only a select few can lead to disease progression. Some of these viruses can amplify cancer-related traits, particularly when coupled with factors like immunosuppression and co-carcinogens. The global burden of cancer development resulting from viral infections is approximately 12%, and it arises as an unfortunate consequence of persistent infections that cause chronic inflammation, genomic instability from viral genome integration, and dysregulation of tumor suppressor genes and host oncogenes involved in normal cell growth. This review provides an in-depth discussion of oncoviruses and their strategies for hijacking the host's cellular machinery to induce cancer. It delves into how viral oncogenes drive tumorigenesis by targeting key cell signaling pathways. Additionally, the review discusses current therapeutic approaches that have been approved or are undergoing clinical trials to combat malignancies induced by oncoviruses. Understanding the intricate interactions between viruses and host cells can lead to the development of more effective treatments for virus-induced cancers.

Parthenolide inhibits proliferation of cells infected with Kaposi's sarcoma-associated herpesvirus by suppression of the NF-κB signaling pathway

The disease caused by Kaposi's sarcoma-associated herpesvirus (KSHV) is one of the major causes of death of individuals with acquired immunodeficiency syndrome (AIDS). Development of anti-KSHV drugs is thus crucial. In this study, we investigated the effect of parthenolide (PTL) on the proliferation and NF-κB signaling pathway of KSHV-infected cells. iSLK.219 and KSHV-infected SH-SY5Y cells (SK-RG) were treated with PTL, TaqMan real-time quantitative PCR was used to determine the number of copies of the KSHV genome, and mRNA and protein expression of KSHV genes were analyzed by real-time PCR and immunocytochemistry. A cell viability test was used to measure cell proliferation, and flow cytometry was used to examine the effect of the drug on the cell cycle. Cyclin D1, CDK6, CDK4, and NF-κB-related proteins, including IKKβ, P-p65, and P-IKB-α, were detected by Western blot. The results showed that PTL altered the morphology of the cells, reduced the KSHV copy number, and suppressed the production of ORF50, K8.1, and v-GPCR mRNA and the LANA, ORF50, and K8.1 proteins. It blocked the G1 phase in iSLK.219 cells and decreased the levels of cyclin D1, CDK6, and CDK4 as well as the levels of NF-κB signaling proteins, including IKKβ, P-p65, and P-IKB-α. Together, these results suggest that PTL is a candidate drug that can decrease KSHV pathogenicity by suppressing cell proliferation and inhibiting the NF-κB signaling pathway in KSHV-infected cells.

Clinicopathologic Correlation of Kaposi Sarcoma Involving the Ocular Adnexa: Immunophenotyping of Diagnostic and Therapeutic Targets

PURPOSE

To describe the clinicopathologic characteristics and the expression of diagnostic/treatment targets in ocular adnexal Kaposi Sarcoma.

METHODS

We conducted a clinical-pathologic retrospective case series. Immunohistochemical staining for cluster of differentiation 31 (CD31), human herpesvirus-8 (HHV8), platelet-derived growth factor receptor alpha (PDGFR-A), vascular endothelial growth factor receptor-1 (VEGF), tyrosine-protein kinase Kit (c-Kit), and programmed cell death protein 1 (PD-1) were performed. Percentage of positive tumor cells was recorded for PD-1; staining intensity and distribution (H-score) were determined for the remaining stains. A Friedman non-parametric ANOVA analysis evaluated the staining.

RESULTS

The study cohort included 13 patients (age 25 to 95 years; mean 46): 7 lesions were in the eyelid, 5 in the conjunctiva, and 1 in the cornea. Nine of 11 lesions (82%) were in human immunodeficiency syndrome-positive patients (human immunodeficiency syndrome status was unknown in 2 cases). Staging included 6 plaques and 7 nodules. The mean H-scores of CD31, HHV8, c-Kit, VEGF, and PDGF-A were 8.00, 8.23, 2.77, 11.54, and 10.31, respectively. Mean PD-1 staining was 6.46%. The Friedman non-parametric ANOVA analysis showed VEGF, PDGF-A, CD31, and HHV8 differed significantly, and all differed significantly from c-Kit. Programmed cell death protein 1 staining was not significant with any clinical variable.

CONCLUSIONS

Cluster of differentiation 31 and HHV8 are helpful diagnostic adjuncts for ocular adnexal Kaposi Sarcoma. Platelet-derived growth factor receptor alpha and VEGF are promising treatment targets. Programmed cell death protein 1/PD-L1 and c-Kit are targets that are useful in several tumors; their roles in ocular adnexal Kaposi Sarcoma warrant further studies.

A Series of Patients with Kaposi Sarcoma (Mediterranean/Classical Type): Case Presentations and Short Update on Pathogenesis and Treatment

BACKGROUND:

Kaposi’s sarcoma was first described in 1872 by Moritz Kaposi. To date, it is considered a malignant disease is originating from the endothelial cells of the lymphatic vessels believed to be infected with HHV-8. The current classification defines four major epidemiological forms of Kaposi’s sarcoma: classical, endemic, AIDS-associated, and iatrogenic.

CASE REPORT:

A 90-year-old male is presented with multiple plaques- and tumour-shaped brown-violet formations located on an erythematous-livid base in the area of both feet and both shanks. Two samples were taken from the lesions on the skin of the shanks, with histopathological examination and the subsequent immunohistochemistry showing Kaposi’s sarcoma.

CONCLUSIONS:

Kaposi sarcoma is a disease that causes difficulties both in diagnostic and therapeutic respect. The only sure way to determine the correct diagnosis is immunohistochemical staining with the anti-HHV8 antibody. Despite the wide range of systematic and local treatment options, there is still no unified algorithm and a unified strategy for the treatment of Kaposi’s sarcoma.

mTOR, VEGF, PDGFR, and c-kit signaling pathway activation in Kaposi sarcoma

Kaposi sarcoma (KS) is a locally progressive, intermediate-grade vascular neoplasm with no known cure, high recurrence rates, and potential for wide dissemination. Low efficacy and high toxicity limit current therapeutic options for advanced disease. Activation of mammalian target of rapamycin (mTOR), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and c-kit signaling pathways has been implicated in KS pathogenesis and may suggest a role for targeted inhibitors. KS cases were retrospectively retrieved (N=274), most (90%) associated with human immunodeficiency virus. Tissue microarray slides were stained with human herpes virus-8, Friend leukemia integration 1 transcription factor, CD117 (c-kit), phospho-S6 (pS6), PDGF receptor-β, VEGF, and phospho-mTOR. Both intensity and extent of staining were scored. Multiplying these scores for each core yielded total staining H-scores. Human herpes virus-8 was positive in 87% and Friend leukemia integration 1 transcription factor in 95.7% of cases. Most were also VEGF+ (97.6%), pS6+ (95.7%), CD117+ (92.5%), and PDGFRB+ (87.4%). Approximately half (55.6%) were phospho-mTOR+. There was no significant difference in staining among patients with low (<500 cells/mm³) or preserved CD4 T-cell counts. Immunohistochemistry confirms upregulation of the mTOR, PDGF, VEGF, and c-kit pathways in a large cohort of KS samples. Of proteins tested, pS6, downstream of mTOR, demonstrated the highest proportion of strong positivity (67.1%). These results support the possibility of using targeted inhibitors in KS. Overexpression was independent of CD4 count, suggesting that even patients with low counts may be targeted therapy candidates.

Infection of KSHV and Interaction with HIV: The Bad Romance

Kaposi's sarcoma-associated herpesvirus (KSHV), namely, human herpesvirus 8 (HHV-8), is considered as the pathogen of Kaposi's sarcoma (KS), the most frequent cancer in untreated HIV-infected individuals. Patients infected with HIV have a much higher possibility developing KS than average individual. Researchers have found that HIV, which functions as a cofactor of KS, contributes a lot to the development of KS. In this article, we will give a brief introduction of KS and KSHV and how the interaction between KSHV and HIV contributes to the development of KS. Also we will take a glance at the development of treatment in KS, especially AIDS-KS.

Pulmonary Kaposi sarcoma and disseminated Mycobacterium genavense infection in an HIV-infected patient

We report a case of Kaposi sarcoma (KS) and disseminated infection by Mycobacterium genavense in a 40-year-old HIV-positive man with CD4+ T-cell count 5/µL. He presented with anorexia, diarrhoea, cachexia and multiple firm violaceous nodules distributed over the face, neck and upper and lower extremities. Biopsy of a skin nodule was performed, confirming KS. Immunoperoxidase staining for human herpesvirus 8 was strongly positive. Endoscopic examination revealed erosive duodenopathy. Multiple biopsy samples showed numerous acid-fast bacilli at direct microscopic examination. Real-time PCR (RT-PCR) identified M. genavense. A CT scan showed diffuse pulmonary infiltrates with a 'tree-in-bud' appearance, striking splenomegaly and abdominal lymphadenopathy. A bronchoscopy was performed, revealing typical Kaposi's lesions in the upper respiratory tract. RT-PCR of bronchial aspirate identified M. genavense and Pneumocystis jirovecii. Despite treatment with highly active antiretroviral therapy, antimycobacterial therapy and trimethoprim/sulfamethoxazole, the outcome was fatal.

Isolated kaposi sarcoma of the tonsil: a case report and review of the scientific literature

Kaposi sarcoma is a tumour caused by human herpes virus 8, also known as Kaposi sarcoma-associated herpes virus. It usually affects the skin and oral mucosa; however, it can also sometimes affect the lungs, the liver, the stomach, the bowel, and lymph nodes. Several body sites may be affected simultaneously. The involvement of the tonsils is rare. We described an isolated localization of Kaposi's sarcoma of the right tonsil in a HIV-positive patient.

Review of latent and lytic phase biomarkers in Kaposi's sarcoma

INTRODUCTION

Kaposi's sarcoma (KS) is a vascular neoplasm with distinct clinical-epidemiological subtypes and varied clinical presentations. While the association of KS with human herpesvirus-8 (HHV8, KSHV) infection is well known, additional factors are needed for tumorigenesis. The precise sequence of events involved in KS development, progression and regression continues to be investigated. The discovery of KSHV biomarkers is helpful for diagnostic purposes, for understanding KS pathogenesis and for identifying potential druggable targets.

AREAS COVERED

This article reviews a number of key biomarkers relevant for the diagnosis of KS and HHV8-related pathogenesis. New developments in KS, potential therapeutic targets and the challenges involved in their discovery are highlighted.

EXPERT OPINION

Although there is currently no cure for KS, continued research devoted to uncovering biomarkers and understanding their pathogenic roles remains encouraging. The hope is that sometime soon one of these candidate targets will provide a curative therapy for this enigmatic sarcoma.

Kaposi sarcoma

Kaposi sarcoma (KS) is a low-grade vascular tumor associated with Kaposi sarcoma herpesvirus/human herpesvirus 8 (KSHV/HHV8) infection. Kaposi sarcoma lesions predominantly present at mucocutaneous sites, but may involve all organs and anatomic locations. Recognized epidemiologic-clinical forms of KS include classic, African (endemic), AIDS-associated (epidemic), and iatrogenic KS. New clinical manifestations have been described, such as antiretroviral therapy-related KS regression or flares. Kaposi sarcoma lesions evolve from early (patch stage) macules into plaques (plaque stage) that grow into larger nodules (tumor stage). Newer histologic variants include anaplastic, hyperkeratotic, lymphangioma-like, bullous, telangiectatic, ecchymotic, keloidal, pyogenic granuloma-like, micronodular, intravascular, glomeruloid and pigmented KS, as well as KS with sarcoidlike granulomas and KS with myoid nodules. Latency-associated nuclear antigen (HHV8) is the most specific immunohistochemical marker available to help distinguish KS from its mimics. Since KS remains one of the most common AIDS-defining malignancies, it is important that pathologists be able to recognize KS and its contemporary manifestations.

Advances in the systemic treatment of cutaneous sarcomas

Cutaneous sarcomas are a rare subset of soft tissue sarcomas. These tumors are primarily managed with definitive surgical resection; however, upon unresectable recurrence or metastatic spread, systemic therapy is warranted. As with other sarcomas, these treatments have classically included cytotoxic chemotherapy programs that were associated with variable response rates and poor overall survival. Recently, major advances have been made in the understanding of the molecular biology of these tumors, and treatment paradigms are changing. Multiple pathways have been documented to be important in the growth of cutaneous sarcomas, including receptor tyrosine kinases such as platelet-derived growth factor receptor, insulin-like growth factor receptor and KIT. Dysregulated angiogenesis, through vascular endothelial growth factor (VEGF) and other pathways, is also associated with the growth of these tumors. In this review, we discuss the current standard therapies of cutaneous sarcoma and the recent advances and ongoing investigations into cutaneous sarcoma biology.

[Pulmonary involvement due to HHV-8 virus during the course of HIV infection]

HHV-8 is a herpes virus discovered in 1994 in Kaposi sarcoma cells. Its involvement was later demonstrated in multicentric Castleman disease and in primary lymphoma effusion lymphoma. These diseases arise almost exclusively in immunocompromised patients, mostly in association with HIV infection. Apart from Kaposi's sarcoma, combined antiretroviral therapy does not seem to have reduced the incidence of these diseases, which remain rare. In these three diseases, pulmonary involvement is common and may be the presenting feature. Kaposi's sarcoma of the lung is usually asymptomatic but may require specific therapy. Pulmonary involvement is mostly associated with cutaneous disease. Patients with Castleman disease typically present with fever and lymphadenopathy, associated with interstitial lung disease without opportunistic infection. Patients with primary lymphoma effusion presents with fever and an exudative lymphocytic pleural effusion, without a pleural mass on the CT-scan. Rapid diagnosis of these conditions avoids unnecessary invasive examinations and leads to prompt specific treatment.