Condyloma and coincidental epidermodysplasia verruciformis acanthoma positive for human papillomavirus-14 and -21.

Epidermodysplasia verruciformis (EDV) is a rare genodermatosis that predisposes individuals to persistent infection with ß-human papillomavirus (HPV) genotypes. The term EDV acanthoma may be applied to lesions with incidental findings of EDV-defining histopathological features without clinical signs of EDV. We report a case of HPV-14- and -21-positive EDV acanthoma arising in association with condyloma in a female patient with a history of low-grade squamous intraepithelial lesion of the cervix positive for high-risk HPV (non-16/18), chronic kidney disease, and systemic lupus erythematosus. The patient had no family or personal history of EDV, but the patient was on immunosuppressive therapy with mycophenolate mofetil and prednisone. A biopsy specimen from one of the perianal lesions revealed histopathologic changes consistent with EDV in the setting of condyloma. Molecular testing showed HPV-14 and -21, which supported the coexistence of condyloma with EDV acanthoma.

Effect of selinexor on lipogenesis in virus-positive Merkel cell carcinoma cell lines.

BACKGROUND: Merkel cell carcinoma (MCC) is a highly aggressive neuroendocrine cutaneous carcinoma aetiologically linked to the Merkel cell polyomavirus (MCPyV). Immune checkpoint inhibitors are currently the first-line therapy for metastatic MCC; however, the treatment is effective in only about half of patients, highlighting the need for alternative therapies. Selinexor (KPT-330) is a selective inhibitor of nuclear exportin 1 (XPO1) and has been shown to inhibit MCC cell growth in vitro, but the pathogenesis has not been established. Decades of research have established that cancer cells significantly upregulate lipogenesis to meet an increased demand for fatty acids and cholesterol. Treatments that inhibit lipogenic pathways may halt cancer cell proliferation. AIM: To determine the effect of increasing doses of selinexor on fatty acid and cholesterol synthesis in MCPyV-positive MCC (MCCP) cell lines and aid in elucidating the mechanism by which selinexor prevents and reduces MCC growth. METHODS: MKL-1 and MS-1 cell lines were treated with increasing doses of selinexor for 72 h. Protein expression quantification was determined using chemiluminescent Western immunoblotting and densitometric analysis. Fatty acids and cholesterol were quantified using free fatty acid assay and cholesterol ester detection kits. RESULTS: Selinexor causes statistically significant reductions of the lipogenic transcription factors sterol regulatory element-binding proteins 1 and 2, and lipogenic enzymes acetyl-CoA carboxylase, fatty acid synthase, squalene synthase and 3ß-hydroxysterol Δ-24-reductase in a dose-dependent manner in two MCCP cell lines. Although inhibiting the fatty acid synthesis pathway results in meaningful decreases in fatty acids, the cellular cholesterol levels did not demonstrate such reductions. CONCLUSION: For patients with metastatic MCC refractory to immune checkpoint inhibitors, selinexor may provide clinical benefit through the inhibition of the lipogenesis pathway; however, further research and clinical trials are needed to evaluate these findings.

Trichodysplasia spinulosa polyomavirus small T antigen synergistically modulates S6 protein translation and DNA damage response pathways to shape host cell environment.

TSPyV is a viral agent linked to Trichodysplasia spinulosa, a disfiguring human skin disease which presents with hyperkeratotic spicule eruption in immunocompromised hosts. This proliferative disease state requires extensive modulation of the host cell environment. While the small T (sT) antigen of TSPyV has been postulated to cause widespread cellular perturbation, its specific substrates and their mechanistic connection are unclear. To identify the cellular substrates and pathways perturbed by TSPyV sT and propose a nuanced model that reconciles the multiple arms of TSPyV pathogenesis, changes in expression of several proteins and phospho-proteins in TSPyV sT expressing and TSPyV sT deletion mutant-expressing cell lysates were interrogated using Western blot assays. TSPyV sT expression exploits the DNA damage response pathway, by inducing hyperphosphorylation of ATM and 53BP1 and upregulation of BMI-1. Concurrently, sT dysregulates the S6 protein translation pathway via hyperphosphorylation of CDC2, p70 S6 kinase, S6, and PP1α. The S6S244/247 and p-PP1αT320 phospho-forms are points of overlap between the DDR and S6 networks. We propose a mechanistic rationale for previous reports positioning sT antigen as the key driver of TSPyV pathogenesis. We illuminate novel targets in the S6 and DDR pathways and recognize a potential synergy between these pathways. TSPyV may sensitize the cell to both unrestricted translation and genomic instability. This multi-pronged infection model may inform future therapeutic modalities against TSPyV and possibly other viruses with overlapping host substrates.

Eosinophilic homogeneous intracytoplasmic inclusion bodies: Unique viral cytopathic changes associated with epidermodysplasia verruciformis and human papillomavirus type 49.

Epidermodysplasia verruciformis (EDV) is a rare genodermatosis that predisposes affected individuals to persistent infection with certain types of human papillomavirus (HPV), particularly those that belong to the genus beta-HPV, including HPV-5 and HPV-8, which carry high oncogenic potential. There are three main HPV-related viral cytopathic changes in cutaneous verrucae in terms of intracytoplasmic inclusion bodies (ICBs), namely, granular, filamentous, and homogeneous type ICBs. To date, only HPV-4, HPV-60, and HPV-65 have been found in association with homogeneous ICBs. We report a unique case of HPV-49-associated EDV in a 41-year-old woman with common variable immunodeficiency, mycosis fungoides, and multiple cutaneous malignancies, including squamous cell carcinoma and Merkel cell carcinoma who presented with multiple pink papules and hyperpigmented macules on the left upper extremity. One of the skin lesions histopathologically revealed keratinocytic nuclear enlargement with abundant blue-gray cytoplasm, accompanied by hypergranulosis, characteristic of EDV, along with peculiar bright eosinophilic and homogeneous ICBs. To the best of our knowledge, this is the first reported case of EDV with detection of HPV-49 by genotyping, which features eosinophilic homogeneous ICBs, like those seen in the setting of HPV-4, HPV-60, or HPV-65 infection.

Selinexor is a novel inhibitor of DNA damage response in Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is a highly lethal cutaneous carcinoma, which in ~80% of cases in the USA is aetiologically linked to Merkel cell polyomavirus (MCPyV). Immune checkpoint inhibitors (ICIs) can successfully treat ~50% of patients with metastatic MCC, but some MCCs are refractory to ICIs, possibly due to altered DNA damage response (DDR). Selinexor, an anticancer therapy that is currently approved in combination with chemotherapy for multiple myeloma, downregulates the small T and large T tumour antigens in MCC through selective inhibition of nuclear exportin 1 (XPO1). We examined the effect of varying doses of selinexor on DDR protein expression in MCPyV-positive and MCPyV-negative MCC cells. Selinexor was found to inhibit DDR protein expression in both MCPyV-positive and MCPyV-negative cells. Addition of selinexor alone or combined with ICI may be a promising treatment for MCC, but further in vivo research and clinical trials are required to validate these findings.

The effect of selinexor on prostaglandin synthesis in virus-positive Merkel cell carcinoma cell lines.

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer with high rates of metastasis and mortality. In vitro studies suggest that selinexor (KPT-330), an inhibitor of exportin 1, may be a targeted therapeutic option for MCC. This selective inhibitor prevents the transport of oncogenic mRNA out of the nucleus. Of note, 80% of MCC tumors are integrated with Merkel cell polyomavirus (MCPyV), and virally encoded tumor-antigens, small T (sT) and large T (LT) mRNAs may require an exportin transporter to relocate to the cytoplasm and modulate host tumor-suppressing pathways. To explore selinexor as a targeted therapy for MCC, we examine its ability to inhibit LT and sT antigen expression in vitro and its impact on the prostaglandin synthesis pathway. Protein expression was determined through immunoblotting and quantified by densitometric analysis. Statistical significance was determined with t-test. Treatment of MCPyV-infected cell lines with selinexor resulted in a significant dose-dependent downregulation of key mediators of the prostaglandin synthesis pathway. Given the role of prostaglandin synthesis pathway in MCC, our findings suggest that selinexor, alone or in combination with immunotherapy, could be a promising treatment for MCPyV-infected MCC patients who are resistant to chemotherapy and immunotherapy.

Current treatments and emerging therapies of human polyomavirus-associated skin diseases: a comprehensive review.

Since Merkel cell polyomavirus (MCPyV) was linked as the predominant etiology of Merkel cell carcinoma (MCC) in 2008, three additional human polyomaviruses (HPyV) have been definitively linked to cutaneous diseases-trichodysplasia spinulosa virus (TSPyV) and human polyomavirus 6 and 7 (HPyV6, HPyV7). TSPyV contributes to the development of trichodysplasia spinulosa (TS), and HPyV6/7 is associated closely with the eruption of pruritic and dyskeratotic dermatoses (PDD). Clinically, MCC is treated with surgical excision and radiation with adjuvant chemotherapy, although newer treatment options include immune checkpoint inhibition. These novel immunotherapies hold promise for the treatment of metastatic MCC, but resistance and side effects prevent a significant proportion of patients from realizing their benefits. Based on previous case reports, the standard of care for the less deadly but disfiguring cutaneous disease TS include immunosuppressant (IS) reduction, the use of antivirals such as cidofovir (CDV) or valganciclovir (VGCV), or a combination of these treatments. Similar treatments were attempted for PDD, but oral acitretin was found to be most effective. As MCC, TS, and PDD are rare diseases, further research is required for effective treatments. In this review, we summarize clinical trials, preclinical studies, and case reports that present outcomes and side effects of current and emerging treatments for HPyV-associated cutaneous diseases, offering a comprehensive resource for clinical application and prospective clinical trials.

The efficacy of selinexor (KPT-330), an XPO1 inhibitor, on non-hematologic cancers: a comprehensive review.

PURPOSE: Selinexor is a novel XPO1 inhibitor which inhibits the export of tumor suppressor proteins and oncoprotein mRNAs, leading to cell-cycle arrest and apoptosis in cancer cells. While selinexor is currently FDA approved to treat multiple myeloma, compelling preclinical and early clinical studies reveal selinexor's efficacy in treating hematologic and non-hematologic malignancies, including sarcoma, gastric, bladder, prostate, breast, ovarian, skin, lung, and brain cancers. Current reviews of selinexor primarily highlight its use in hematologic malignancies; however, this review seeks to summarize the recent evidence of selinexor treatment in solid tumors. METHODS: Pertinent literature searches in PubMed and the Karyopharm Therapeutics website for selinexor and non-hematologic malignancies preclinical and clinical trials. RESULTS: This review provides evidence that selinexor is a promising agent used alone or in combination with other anticancer medications in non-hematologic malignancies. CONCLUSION: Further clinical investigation of selinexor treatment for solid malignancies is warranted.