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.

Resolution of painful trichodysplasia spinulosa with topical cidofovir: case report.

Purpose: Trichodysplasia spinulosa (TS) is a rare, disfiguring skin condition which presents with widespread asymptomatic or pruritic, skin-colored papules with white protruding keratin spiculations in immunocompromised individuals. Due to its rarity, there is little data to guide treatment decisions. The purpose of this article is to report a case of TS that completely resolved after treatment with topical cidofovir.Materials and methods: A 19-year-old immunosuppressed female presented with widespread painful, itchy bumps on the nose and face. Upon examination, there were erythematous papules with hyperkeratinized spicules affecting the central face. Biopsy of the lesions was consistent with TS which was confirmed via PCR analysis. The tenderness of this patient's eruption was highly atypical for TS. Once daily topical application of compounded 1% cidofovir cream was prescribed.Results: The patient's symptoms resolved completely after 4 weeks of therapy with topical cidofovir 1% cream, without reduction of immunosuppression.Conclusions: Topical cidofovir 1% cream may be a valuable treatment for this rare disease.

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.

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.

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.

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.

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.

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.

Acquired epidermodysplasia verruciformis: clinical presentation and treatment update.

Acquired epidermodysplasia verruciformis (AEV) is a form of epidermodysplasia verruciformis (EV) that is most commonly found in immunocompromised or immunosuppressed patients. EV is commonly associated with human papillomavirus (HPV), which is often found in EV and AEV lesions. Clinical presentation of AEV in patients with organ transplantation, HIV+, congenital HIV+, hematological diseases, and other iatrogenic immunosuppression are reviewed. Treatment options include topical cidofovir, topical retinoids, topical imiquimod, topical glycolic acid, HPV 9-valent vaccine, acitretin, improving cellular immunity, and changing transplant medication to mycophenolate mofetil.

Concurrent Adjacent Merkel Cell Carcinoma and Chronic Lymphocytic Leukemia without Simultaneous Merkel Cell Polyomavirus Detection: A Case Series.

BACKGROUND: The association between Merkel cell carcinoma (MCC) and chronic lymphocytic leukemia/small lymphocytic leukemia (CLL/SLL) is well established in the literature. A majority of MCCs are known to be associated with Merkel cell carcinoma polyomavirus (MCPyV), which is postulated to be a possible causative agent linking these two entities. We aim to identify the presence of MCPyV in patients with concurrent adjacent MCC and CLL/SLL. METHODS: Archived pathology materials of three cutaneous or surgical excisions with concurrent MCC and CLL/SLL were reviewed. Additional 12-µm sections from paraffin-embedded tissue of these resections were matched with original hematoxylin and eosin-stained slides and used to extract foci from each tumor separately. DNA was extracted from these tissues, and polymerase chain reaction (PCR), utilizing a primer set within a highly conserved "small T" viral DNA region, was done to detect MCPyV. RESULTS: Out of 140 cases of cutaneous or surgical excisions with MCC identified in our electronic medical records (EMR), three had coexisting neighboring CLL/SLL in the same resection specimen. In one case out of three, MCPyV was detected in MCC but not in CLL/SLL. The remaining two cases showed no detection of MCPyV in either MCC or CLL/SLL. CONCLUSION: MCPyV was not concurrently associated with adjacent MCC and CLL/SLL, indicating that it is not driving simultaneous tumorigenesis, at least in a subset of these cases.

A case report of disseminated verrucosis secondary to ustekinumab in a patient with Crohn's disease.

Ustekinumab is a biologic agent with Food and Drug Administration approval for the treatment of moderate-to-severe plaque psoriasis, psoriatic arthritis, ulcerative colitis, and Crohn's disease. It functions to inhibit the p40 subunit common to both interleukin-12 and interleukin-23. These pro-inflammatory cytokines are implicated in autoinflammatory and autoimmune disorders, but they also play an important role in cell-mediated immunity against viral, bacterial, and fungal pathogens. Therefore, antagonism of interleukin-12 and interleukin-23 by ustekinumab may increase the risk of human papillomavirus infection or reactivation which can lead to the development of verrucae. To the best of our knowledge, there is only one published report of disseminated verrucosis secondary to ustekinumab treatment for psoriasis. Here, we present the first case report of ustekinumab-induced disseminated verrucosis occurring in the setting of treatment for Crohn's disease.

Effects of ß-HPV on DNA damage response pathways to drive carcinogenesis: a review.

The DDR is a complex signaling network responsible for the preservation of genomic integrity. Beta human papillomaviruses (ß-HPVs) are able to destabilize the host genome by attenuating the DDR machinery at the molecular scale following expression of the oncogenes E6 and E7. In the event of ß-HPV infection, the E6- and E7-mediated inhibition of the DDR enhances the oncogenicity of UV-induced mutations to enable carcinogenesis in an otherwise immunocompetent host, marking an important mechanistic divergence from the alpha genus of HPVs. In this review, we summarize recent updates to build upon the 'hit-and-run' hypothesis of ß-HPV pathomechanism and highlight strain-dependent variations. Simultaneously, we illuminate points within the ß-HPV-DDR interface that may unravel new insights for HPV viral genetics, genus-specific mechanistic models, and developments in targeted molecular therapy of ß-HPV-related cancers.

The contribution of human papilloma virus infection to cutaneous squamous cell carcinoma in patients with chronic lymphocytic leukemia.

Patients with chronic lymphocytic leukemia (CLL), a B-cell malignancy characterized by impaired humoral and cellular immunity, are at increased risk of developing cutaneous squamous cell carcinoma (cSCC). Human papilloma virus (HPV) is the most common sexually transmitted infection worldwide and it has been associated with various malignancies, including cSCC. Impaired cell-mediated immunity is considered a primary risk factor in HPV-induced cSCC. We examined cSCC lesions from CLL patients with consensus review and HPV genetic analysis to further characterize the relationship between HPV and prevalence of cutaneous malignancy in this population. Eleven patients with CLL contributed 35 cSCCs. Treatment with chemotherapy shortened the latency time to first cSCC. HPV was detected in 54% of the lesions. Among the HPV-positive cSCC lesions, 84% of the lesions contained alpha-genus HPV, 42% contained beta-genus HPV, and 26% of the lesions contained both genera. There was a significant association between HPV-containing lesions and peritumoral lymphocytic inflammation, suggesting this as a future area for further characterization. The majority of the lesions, including those with alpha-genus HPV, occurred in sun-exposed areas, such as the scalp and face. These findings may lead to practice-changing recommendations for skin cancer, including the use of vaccinations to reduce HPV-associated skin cancer.

Heck's disease occurring after Epstein-Barr virus-associated smooth muscle tumors in an immunosuppressed child.

A 10-year-old Guatemalan girl with past medical history of Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) and combined immunodeficiency presented for evaluation of painful intraoral lesions. On examination, she was noted to have multiple, white to flesh-colored, soft, flat-topped papules, and plaques on the buccal and labial mucosa. Human papillomavirus type 13 was detected on PCR with PGMY primers of previously biopsied buccal tissue, confirming a diagnosis of Heck's disease (multifocal epithelial hyperplasia). We present an immunosuppressed, pediatric patient with two rare, virus-associated neoplastic disorders that have not been previously reported to occur in the same individual.