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1.
Proc Natl Acad Sci U S A ; 121(34): e2403133121, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39141346

RESUMEN

Polyomaviruses are small, circular dsDNA viruses that can cause cancer. Alternative splicing of polyomavirus early transcripts generates large and small tumor antigens (LT, ST) that play essential roles in viral replication and tumorigenesis. Some polyomaviruses also express middle tumor antigens (MTs) or alternate LT open reading frames (ALTOs), which are evolutionarily related but have distinct gene structures. MTs are a splice variant of the early transcript whereas ALTOs are overprinted on the second exon of the LT transcript in an alternate reading frame and are translated via an alternative start codon. Merkel cell polyomavirus (MCPyV), the only human polyomavirus that causes cancer, encodes an ALTO but its role in the viral lifecycle and tumorigenesis has remained elusive. Here, we show MCPyV ALTO acts as a tumor suppressor and is silenced in Merkel cell carcinoma (MCC). Rescuing ALTO in MCC cells induces growth arrest and activates NF-κB signaling. ALTO activates NF-κB by binding SQSTM1 and TRAF2&3 via two N-Terminal Activating Regions (NTAR1+2), resembling Epstein-Barr virus (EBV) Latent Membrane Protein 1 (LMP1). Following activation, NF-κB dimers bind the MCPyV noncoding control region (NCCR) and downregulate early transcription. Beyond MCPyV, NTAR motifs are conserved in other polyomavirus ALTOs, which activate NF-κB signaling, but are lacking in MTs that do not. Furthermore, polyomavirus ALTOs downregulate their respective viral early transcription in an NF-κB- and NTAR-dependent manner. Our findings suggest that ALTOs evolved to suppress viral replication and promote viral latency and that MCPyV ALTO must be silenced for MCC to develop.


Asunto(s)
Regulación Viral de la Expresión Génica , FN-kappa B , Transducción de Señal , Humanos , FN-kappa B/metabolismo , Antígenos Virales de Tumores/genética , Antígenos Virales de Tumores/metabolismo , Poliomavirus de Células de Merkel/genética , Infecciones por Polyomavirus/virología , Infecciones por Polyomavirus/genética , Infecciones por Polyomavirus/metabolismo , Carcinoma de Células de Merkel/virología , Carcinoma de Células de Merkel/genética , Carcinoma de Células de Merkel/metabolismo , Sistemas de Lectura Abierta/genética , Línea Celular Tumoral , Regulación hacia Abajo , Empalme Alternativo
2.
J Pathol ; 264(1): 112-124, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39049595

RESUMEN

Merkel cell carcinoma (MCC) is an aggressive skin cancer frequently caused by genomic integration of the Merkel cell polyomavirus (MCPyV). MCPyV-negative cases often present as combined MCCs, which represent a distinctive subset of tumors characterized by association of an MCC with a second tumor component, mostly squamous cell carcinoma. Up to now, only exceptional cases of combined MCC with neuroblastic differentiation have been reported. Herein we describe two additional combined MCCs with neuroblastic differentiation and provide comprehensive morphologic, immunohistochemical, transcriptomic, genetic and epigenetic characterization of these tumors, which both arose in elderly men and appeared as an isolated inguinal adenopathy. Microscopic examination revealed biphasic tumors combining a poorly differentiated high-grade carcinoma with a poorly differentiated neuroblastic component lacking signs of proliferation. Immunohistochemical investigation revealed keratin 20 and MCPyV T antigen (TA) in the MCC parts, while neuroblastic differentiation was confirmed in the other component in both cases. A clonal relation of the two components can be deduced from 20 and 14 shared acquired point mutations detected by whole exome analysis in both combined tumors, respectively. Spatial transcriptomics demonstrated a lower expression of stem cell marker genes such as SOX2 and MCM2 in the neuroblastic component. Interestingly, although the neuroblastic part lacked TA expression, the same genomic MCPyV integration and the same large T-truncating mutations were observed in both tumor parts. Given that neuronal transdifferentiation upon TA repression has been reported for MCC cell lines, the most likely scenario for the two combined MCC/neuroblastic tumors is that neuroblastic transdifferentiation resulted from loss of TA expression in a subset of MCC cells. Indeed, DNA methylation profiling suggests an MCC-typical cellular origin for the combined MCC/neuroblastomas. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Asunto(s)
Antígenos Virales de Tumores , Carcinoma de Células de Merkel , Transdiferenciación Celular , Poliomavirus de Células de Merkel , Neoplasias Cutáneas , Humanos , Carcinoma de Células de Merkel/patología , Carcinoma de Células de Merkel/virología , Carcinoma de Células de Merkel/genética , Carcinoma de Células de Merkel/metabolismo , Masculino , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/virología , Neoplasias Cutáneas/metabolismo , Antígenos Virales de Tumores/genética , Antígenos Virales de Tumores/metabolismo , Poliomavirus de Células de Merkel/genética , Puntos de Control del Ciclo Celular/genética , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Anciano de 80 o más Años , Anciano , Neoplasias Complejas y Mixtas/patología , Neoplasias Complejas y Mixtas/genética , Neoplasias Complejas y Mixtas/metabolismo , Neuroblastoma/patología , Neuroblastoma/genética , Neuroblastoma/metabolismo
3.
Rev Med Virol ; 34(5): e2580, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39228116

RESUMEN

Merkel cell polyomavirus (MCPyV) is a significant contributor to the development of Merkel cell carcinoma (MCC), an aggressive skin cancer with high recurrence and a low survival rate. In fact, it is the deadliest skin cancer. The precise routes of transmission for MCPyV-positive MCC remain unclear, but several factors may trigger its development. Conventional treatments for MCC are not highly effective, especially in patients with metastasis, with a clear need for new treatment options. Gene-targeted therapies hold great promise for the treatment of MCC, including the use of siRNA and CRISPR/Cas (C/Cas) but critically none have yet been translated into clinical trials. Validating this approach is the fact that several siRNA products are already FDA licenced, while C/Cas has entered clinical trial, albeit for conditions other than MCC. There are many challenges that must be overcome to move from preclinical research to the clinic. In this review, we provide a comprehensive summary of the current understanding of MCC, with a particular focus on MCPyV-positive MCC, and the status of gene-targeted therapies. Additionally, we discuss the major obstacles that impede MCC research and explore future prospects.


Asunto(s)
Carcinoma de Células de Merkel , Terapia Genética , Poliomavirus de Células de Merkel , Infecciones por Polyomavirus , Humanos , Poliomavirus de Células de Merkel/genética , Carcinoma de Células de Merkel/virología , Carcinoma de Células de Merkel/terapia , Carcinoma de Células de Merkel/genética , Infecciones por Polyomavirus/virología , Infecciones por Polyomavirus/terapia , Terapia Genética/métodos , Neoplasias Cutáneas/terapia , Neoplasias Cutáneas/virología , Neoplasias Cutáneas/genética , Animales , Infecciones Tumorales por Virus/virología , Infecciones Tumorales por Virus/terapia , ARN Interferente Pequeño/genética
4.
Lab Invest ; 104(10): 102128, 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39182611

RESUMEN

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma. Checkpoint inhibitor immunotherapy plays an essential role in management of advanced MCC; however, predictors of immunotherapy response remain poorly defined. Syngeneic mouse models suitable for testing novel immunotherapy and combination therapy approaches are likely to soon become available and will require assays for evaluating the tumor microenvironment (TME). Multiplex immunofluorescence (mIF) is a powerful approach to characterize the TME for understanding immunotherapy responses and immune surveillance. In this method article, we provide detailed instructions on assay development for mIF, using as examples 2 new mIF panels for TME investigations of human and murine MCC tumors. Specifically, we demonstrate panels that allow simultaneous visualization of the Merkel cell master transcription factor SOX2 for tumor cell identification, alongside T-cell markers (CD3, CD8, and FOXP3), macrophage markers (F4/80 for mouse and CD163 for human tumors), together with the checkpoint marker PD-L1 for human tumors, and the myeloid-derived suppressor cell marker Arg1 for mouse tumors. We provide detailed protocols for investigators to incorporate these mIF panels into their investigations of human and murine MCC. We also provide fundamental guidance for mIF assay development that will be broadly useful for investigators who consider modifying the panels presented in this study or developing their own mIF panels.

5.
Lab Invest ; 104(9): 102123, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39147033

RESUMEN

Tumor-stroma ratio (TSR) has been recognized as a valuable prognostic indicator in various solid tumors. This study aimed to examine the clinicopathologic relevance of TSR in Merkel cell carcinoma (MCC) using artificial intelligence (AI)-based parameterization of the stromal landscape and validate TSR scores generated by our AI model against those assessed by humans. One hundred twelve MCC cases with whole-slide images were collected from 4 different institutions. Whole-slide images were first partitioned into 128 × 128-pixel "mini-patches," then classified using a novel framework, termed pre-tumor and stroma (Pre-TOAST) and TOAST, whose output equaled the probability of the minipatch representing tumor cells rather than stroma. Hierarchical random samplings of 50 minipatches per region were performed throughout 50 regions per slide. TSR and tumor-stroma landscape (TSL) parameters were estimated using the maximum-likelihood algorithm. Receiver operating characteristic curves showed that the area under the curve value of Pre-TOAST in discriminating classes of interest including tumor cells, collagenous stroma, and lymphocytes from nonclasses of interest including hemorrhage, space, and necrosis was 1.00. The area under the curve value of TOAST in differentiating tumor cells from related stroma was 0.93. MCC stroma was categorized into TSR high (TSR ≥ 50%) and TSR low (TSR < 50%) using both AI- and human pathology-based methods. The AI-based TSR-high subgroup exhibited notably shorter metastasis-free survival (MFS) with a statistical significance of P = .029. Interestingly, pathologist-determined TSR subgroups lacked statistical significance in recurrence-free survival, MFS, and overall survival (P > .05). Density-based spatial clustering of applications with noise analysis identified the following 2 distinct TSL clusters: TSL1 and TSL2. TSL2 showed significantly shorter recurrence-free survival (P = .045) and markedly reduced MFS (P < .001) compared with TSL1. TSL classification appears to offer better prognostic discrimination than traditional TSR evaluation in MCC. TSL can be reliably calculated using an AI-based classification framework and predict various prognostic features of MCC.


Asunto(s)
Inteligencia Artificial , Carcinoma de Células de Merkel , Neoplasias Cutáneas , Humanos , Carcinoma de Células de Merkel/patología , Carcinoma de Células de Merkel/mortalidad , Femenino , Masculino , Anciano , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/mortalidad , Anciano de 80 o más Años , Células del Estroma/patología , Persona de Mediana Edad , Pronóstico
6.
Cancer ; 130(3): 433-438, 2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-37788133

RESUMEN

BACKGROUND: Immune checkpoint inhibitor treatment of patients with metastatic Merkel cell carcinoma (mMCC) has shown high response rates, ranging from 33% to 73%. The ideal duration of treatment, however, is currently unknown. The aim of this study was to evaluate if avelumab treatment for mMCC can be safely stopped after 1 year of treatment and a complete response (CR) confirmed by fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging. METHODS: Patients who received more than one dose of avelumab treatment for mMCC between November 2017 and February 2022 were included in this study. Treatment was discontinued in case of a FDG-PET/CT confirmed CR after 1 year (26 cycles) of avelumab or a CR and unacceptable toxicity earlier. The primary end point was recurrence-free survival (RFS). RESULTS: Sixty-five patients were included: 25 (38%) had a FDG-PET/CT-confirmed CR at discontinuation of avelumab. In those 25 patients, reasons for discontinuation of treatment were completion of 1 year of treatment in 13 (52%), toxicity in five (20%), and patient preference in seven (28%). Median duration of treatment in this group was 11 months (interquartile range, 6.1-11.7). Median follow-up was 27 months (interquartile range, 15.8-33.8). The 12-month RFS was 88% (95% CI, 0.74-1) and median RFS was not reached. Two patients (8%) had a recurrence at 4 and 7 months after discontinuation of treatment. CONCLUSIONS: Patients with mMCC who acquire a CR on PET/CT imaging appear to have durable responses after discontinuation of treatment after 1 year.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Carcinoma de Células de Merkel , Neoplasias Cutáneas , Humanos , Carcinoma de Células de Merkel/diagnóstico por imagen , Carcinoma de Células de Merkel/tratamiento farmacológico , Carcinoma de Células de Merkel/inducido químicamente , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias Cutáneas/diagnóstico por imagen , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/inducido químicamente , Fluorodesoxiglucosa F18 , Anticuerpos Monoclonales/efectos adversos
7.
Cancer ; 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39101686

RESUMEN

BACKGROUND: Serum antibodies to the Merkel oncoprotein (AMERK) are detectable in approximately 50% of patients with Merkel cell carcinoma (MCC) and can be used to monitor for recurrence. The objective of this study was to characterize AMERK levels in patients receiving curative-intent radiation therapy (RT) for MCC and identify associations between AMERK and recurrence. METHODS: This was a retrospective study of patients with MCC who had baseline AMERK measurements before they received curative-intent RT from 2010 to 2020. Event-free survival (EFS) was calculated using the Kaplan-Meier method and Cox regression. The cumulative incidence of MCC-related recurrence (CIMR) was analyzed with death as a competing risk and the Gray test. RESULTS: The authors identified 88 patients who had baseline AMERK measurements, including 52 (59%) with detectable levels. AMERK positivity was associated with younger median age (67.8 vs. 72.0 years; p = .02) and tumor site (p = 0.02), with lower rates for those who had disease in the head/neck region (17.3% vs. 44.4%). EFS (71.3% vs. 60.4%; p = .30) and CIMR (24.4% vs. 39.6%; p = .23) were more favorable in AMERK-positive patients. Two patients had recurrences in the RT field, and both were AMERK-negative at baseline. The median time to AMERK nadir after RT was 11.2 months; and, in a 6-month post-RT landmark analysis, the proportion of patients who were AMERK-positive who became negative or who had levels that decreased by ≥50% were not associated with EFS (87.1% vs. 85.0%; p = .90) or CIMR (12.9% vs. 15.0%; p = .62). CONCLUSIONS: Positive AMERK baseline levels were correlated with younger age at MCC diagnosis and nonhead and neck tumor location, possibly related to the distribution of viral etiology. A specific post-RT AMERK decline correlating with EFS could not be identified.

8.
Cancer ; 130(15): 2670-2682, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38696121

RESUMEN

BACKGROUND: Merkel cell carcinoma (MCC) is an aggressive cancer with often poor outcomes. Limited biomarkers exist for predicting clinical outcomes. The Merkel cell polyomavirus (MCPyV) serum antibody test (AMERK) has shown potential for indicating better recurrence-free survival in a single-institution study. The study aimed to evaluate the link between initial AMERK serostatus and survival. Secondary objectives included examining the relationship between initial AMERK titer levels and tumor burden. METHODS: A retrospective cohort study across two institutions analyzed patients tested with AMERK within 90 days of MCC diagnosis. Regression models assessed the association of survival outcomes with serostatus, considering various factors. The relationship between AMERK titer and tumor burden indicators was evaluated using ANOVA. Significance testing was exploratory, without a fixed significance level. RESULTS: Of 261 MCC patients tested, 49.4% were initially seropositive (titer ≥75). Multivariable analysis showed that seropositivity improved recurrence, event-free, overall, and MCC-specific survival rates. Strong associations were found between initial AMERK titer and clinical, tumor, and nodal stages, tumor size, and disease extent. Notably, improved survival with seropositivity was observed only in patients with localized disease at initial presentation. CONCLUSION: Circulating antibodies to MCPyV oncoproteins, as indicated by the AMERK test, are linked with better survival in MCC patients with localized disease at presentation. This could enhance patient risk profiling and treatment personalization. The study's retrospective nature and exploratory analysis are key limitations. PLAIN LANGUAGE SUMMARY: Merkel cell carcinoma (MCC) is a potentially aggressive skin cancer, and tools to predict patient outcomes are limited. A blood test called anti-Merkel cell panel (AMERK), which checks for specific antibodies related to this cancer, might give us some clues. In this study, we looked at 261 MCC patients who took the AMERK test within 90 days of diagnosis. We found that patients with an initial positive AMERK result tended to have better outcomes, especially if their cancer was in the early stages. However, it is important to note that this study has limitations, including using retrospective data and exploratory analyses.


Asunto(s)
Anticuerpos Antivirales , Carcinoma de Células de Merkel , Poliomavirus de Células de Merkel , Neoplasias Cutáneas , Humanos , Carcinoma de Células de Merkel/virología , Carcinoma de Células de Merkel/sangre , Carcinoma de Células de Merkel/mortalidad , Carcinoma de Células de Merkel/diagnóstico , Carcinoma de Células de Merkel/inmunología , Poliomavirus de Células de Merkel/inmunología , Poliomavirus de Células de Merkel/aislamiento & purificación , Femenino , Masculino , Estudios Retrospectivos , Anciano , Pronóstico , Persona de Mediana Edad , Neoplasias Cutáneas/sangre , Neoplasias Cutáneas/virología , Neoplasias Cutáneas/mortalidad , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/inmunología , Neoplasias Cutáneas/patología , Anticuerpos Antivirales/sangre , Anciano de 80 o más Años , Infecciones Tumorales por Virus/virología , Infecciones por Polyomavirus/sangre , Infecciones por Polyomavirus/diagnóstico , Infecciones por Polyomavirus/virología , Infecciones por Polyomavirus/inmunología
9.
J Virol ; 97(4): e0190722, 2023 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-36946735

RESUMEN

Merkel cell polyomavirus (MCPyV) has been associated with approximately 80% of Merkel cell carcinoma (MCC), an aggressive and increasingly incident skin cancer. The link between host innate immunity, viral load control, and carcinogenesis has been established but poorly characterized. We previously established the importance of the STING and NF-κB pathways in the host innate immune response to viral infection. In this study, we further discovered that MCPyV infection of human dermal fibroblasts (HDFs) induces the expression of type I and III interferons (IFNs), which in turn stimulate robust expression of IFN-stimulated genes (ISGs). Blocking type I IFN downstream signaling using an IFN-ß antibody, JAK inhibitors, and CRISPR knockout of the receptor dramatically repressed MCPyV infection-induced ISG expression but did not significantly restore viral replication activities. These findings suggest that IFN-mediated induction of ISGs in response to MCPyV infection is not crucial to viral control. Instead, we found that type I IFN exerts a more direct effect on MCPyV infection postentry by repressing early viral transcription. We further demonstrated that growth factors normally upregulated in wounded or UV-irradiated human skin can significantly stimulate MCPyV gene expression and replication. Together, these data suggest that in healthy individuals, host antiviral responses, such as IFN production induced by viral activity, may restrict viral propagation to reduce MCPyV burden. Meanwhile, growth factors induced by skin abrasion or UV irradiation may stimulate infected dermal fibroblasts to promote MCPyV propagation. A delicate balance of these mutually antagonizing factors provides a mechanism to support persistent MCPyV infection. IMPORTANCE Merkel cell carcinoma is an aggressive skin cancer that is particularly lethal to immunocompromised individuals. Though rare, MCC incidence has increased significantly in recent years. There are no lasting and effective treatments for metastatic disease, highlighting the need for additional treatment and prevention strategies. By investigating how the host innate immune system interfaces with Merkel cell polyomavirus, the etiological agent of most of these cancers, our studies identified key factors necessary for viral control, as well as conditions that support viral propagation. These studies provide new insights for understanding how the virus balances the effects of the host immune defenses and of growth factor stimulation to achieve persistent infection. Since virus-positive MCC requires the expression of viral oncogenes to survive, our observation that type I IFN can repress viral oncogene transcription indicates that these cytokines could be explored as a viable therapeutic option for treating patients with virus-positive MCC.


Asunto(s)
Carcinoma de Células de Merkel , Interferones , Infecciones por Polyomavirus , Transducción de Señal , Infecciones Tumorales por Virus , Poliomavirus de Células de Merkel/inmunología , Interferones/fisiología , Transducción de Señal/inmunología , Infecciones por Polyomavirus/inmunología , Infecciones Tumorales por Virus/inmunología , Carcinoma de Células de Merkel/inmunología , Inmunidad Innata/inmunología , Interacciones Microbiota-Huesped/inmunología , Humanos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Expresión Génica/inmunología , Replicación Viral/genética
10.
Mod Pathol ; : 100627, 2024 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-39341281

RESUMEN

Although of therapeutic importance, a single sensitive and specific immunostain to distinguish Merkel cell carcinoma (MCC) from mimics is not currently available. In addition, single tumor cells are difficult to detect in sentinel lymph node biopsy. Leveraging publicly available data sets of 9264 solid tumors and over 600,000 single-cell transcriptomes, we identified POU4F3 to be a specific marker of MCC. Analyses of Pan-Cancer RNA bulk sequencing data of 24 tumor types from Tumor Cancer Genomic Atlas (TCGA) datasets as well as non-TCGA SCLC and MCC datasets confirmed POU4F3 specificity for MCC. Single-cell RNA sequencing analyses also confirmed lack of POU4F3 expression in lung small cell carcinoma as well as a variety of normal tissues. Nuclear POU4F3 immunohistochemical expression was noted in 98.7% of 153 MCCs and in only 1.7% of mimics (3 of 180 cases, including 95 small cell carcinomas of which 55 from lung and the remainder from other sites). Three POU4F3-positive non-MCC cases were from lung (2 cases) and vagina (1 case). All 153 tested MCC cases were negative for ASCL1, a key transcriptional regulator highly expressed in SCLC. NeuroD1 was seen in a subset of MCC cases (20.9%, 32/153). POU4F3 immunostain was performed on 29 sentinel lymph nodes and strong POU4F3 nuclear expression facilitated ease of metastasis detection, even single tumor cells. Our study built on prior works shows that POU4F3 to be a sensitive and specific clinical marker of MCC.

11.
J Med Virol ; 96(7): e29789, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38988206

RESUMEN

Merkel cell carcinoma (MCC) is a highly aggressive skin cancer associated with integration of Merkel cell polyomavirus (MCPyV). MCPyV-encoded T-antigens (TAs) are pivotal for sustaining MCC's oncogenic phenotype, i.e., repression of TAs results in reactivation of the RB pathway and subsequent cell cycle arrest. However, the MCC cell line LoKe, characterized by a homozygous loss of the RB1 gene, exhibits uninterrupted cell cycle progression after shRNA-mediated TA repression. This unique feature allows an in-depth analysis of the effects of TAs beyond inhibition of the RB pathway, revealing the decrease in expression of stem cell-related genes upon panTA-knockdown. Analysis of gene regulatory networks identified members of the E2F family (E2F1, E2F8, TFDP1) as key transcriptional regulators that maintain stem cell properties in TA-expressing MCC cells. Furthermore, minichromosome maintenance (MCM) genes, which encodes DNA-binding licensing proteins essential for stem cell maintenance, were suppressed upon panTA-knockdown. The decline in stemness occurred simultaneously with neural differentiation, marked by the increased expression of neurogenesis-related genes such as neurexins, BTG2, and MYT1L. This upregulation can be attributed to heightened activity of PBX1 and BPTF, crucial regulators of neurogenesis pathways. The observations in LoKe were confirmed in an additional MCPyV-positive MCC cell line in which RB1 was silenced before panTA-knockdown. Moreover, spatially resolved transcriptomics demonstrated reduced TA expression in situ in a part of a MCC tumor characterized by neural differentiation. In summary, TAs are critical for maintaining stemness of MCC cells and suppressing neural differentiation, irrespective of their impact on the RB-signaling pathway.


Asunto(s)
Antígenos Transformadores de Poliomavirus , Antígenos Virales de Tumores , Poliomavirus de Células de Merkel , Células Madre Neoplásicas , Proteínas de Unión a Retinoblastoma , Humanos , Antígenos Virales de Tumores/genética , Antígenos Virales de Tumores/metabolismo , Carcinoma de Células de Merkel/virología , Carcinoma de Células de Merkel/genética , Diferenciación Celular , Línea Celular Tumoral , Técnicas de Silenciamiento del Gen , Redes Reguladoras de Genes , Poliomavirus de Células de Merkel/genética , Células Madre Neoplásicas/virología , Células Madre Neoplásicas/metabolismo , Neuronas/virología , Proteínas de Unión a Retinoblastoma/genética , Proteínas de Unión a Retinoblastoma/metabolismo , Neoplasias Cutáneas/virología , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Antígenos Transformadores de Poliomavirus/genética , Antígenos Transformadores de Poliomavirus/metabolismo
12.
Ann Surg Oncol ; 31(9): 6079-6087, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38824193

RESUMEN

BACKGROUND: Immunotherapy is emerging as a promising option for certain locally advanced and metastatic cutaneous malignancies. However, the role of neoadjuvant immunotherapy (NIO) in Merkel cell carcinoma (MCC) with clinically detected regional lymph node metastasis (CDRLNM) has not been fully elucidated. METHODS: For this study, MCC patients with CDRLNM who underwent surgical excision were selected from the National Cancer Database (NCDB). Those who received NIO were propensity-matched with those who did not, and Kaplan-Meier analysis was used to compare overall survival (OS). RESULTS: Of the 1809 selected patients, 356 (19.7%) received NIO followed by wide excision (n = 352, 98.9%) or amputation (n = 4, 1.1%). The rate of complete pathologic response for the primary tumor (ypT0) was 45.2%. Only 223 patents (63.4%) also underwent lymph node dissection (LND). The complete pathologic nodal response (ypN0) rate for these patients was 17.9%. A pathologic complete response of both the primary tumor and the nodal basin (ypT0 ypN0) was seen in 16 of the 223 patients who underwent both primary tumor surgery and LND. Subsequently, 151 pairs were matched between the NIO and no-NIO groups (including only patients with LND). Kaplan-Meier analysis demonstrated a significant OS improvement with NIO (median not reached vs. 35.0 ± 8.0 months; p = 0.025). The 5-year OS was 57% in the NIO group versus 44% in no-NIO group (p = 0.021). CONCLUSION: The study suggests that NIO in MCC with CDRLNM provides improved OS in addition to promising rates of primary complete response, which could change the profile of surgical resection. This supports ongoing clinical trials exploring the use of NIO in MCC.


Asunto(s)
Carcinoma de Células de Merkel , Metástasis Linfática , Terapia Neoadyuvante , Neoplasias Cutáneas , Humanos , Carcinoma de Células de Merkel/terapia , Carcinoma de Células de Merkel/patología , Carcinoma de Células de Merkel/cirugía , Terapia Neoadyuvante/mortalidad , Masculino , Femenino , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/terapia , Neoplasias Cutáneas/mortalidad , Anciano , Tasa de Supervivencia , Estudios de Seguimiento , Pronóstico , Inmunoterapia/métodos , Persona de Mediana Edad , Anciano de 80 o más Años , Estudios Retrospectivos , Escisión del Ganglio Linfático
13.
Ophthalmology ; 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39127410

RESUMEN

We herein report four patients with periocular Merkel cell carcinoma treated with immune checkpoint inhibitors who experienced a dramatic response and, therefore, had less morbid surgery and/or avoided radiation therapy with its inherent ocular toxicity.

14.
Histopathology ; 84(2): 356-368, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37830288

RESUMEN

AIMS: Merkel cell carcinoma (MCC) is frequently caused by the Merkel cell polyomavirus (MCPyV). Characteristic for these virus-positive (VP) MCC is MCPyV integration into the host genome and truncation of the viral oncogene Large T antigen (LT), with full-length LT expression considered as incompatible with MCC growth. Genetic analysis of a VP-MCC/trichoblastoma combined tumour demonstrated that virus-driven MCC can arise from an epithelial cell. Here we describe two further cases of VP-MCC combined with an adnexal tumour, i.e. one trichoblastoma and one poroma. METHODS AND RESULTS: Whole-genome sequencing of MCC/trichoblastoma again provided evidence of a trichoblastoma-derived MCC. Although an MCC-typical LT-truncating mutation was detected, we could not determine an integration site and we additionally detected a wildtype sequence encoding full-length LT. Similarly, Sanger sequencing of the combined MCC/poroma revealed coding sequences for both truncated and full-length LT. Moreover, in situ RNA hybridization demonstrated expression of a late region mRNA encoding the viral capsid protein VP1 in both combined as well as in a few cases of pure MCC. CONCLUSION: The data presented here suggest the presence of wildtype MCPyV genomes and VP1 transcription in a subset of MCC.


Asunto(s)
Carcinoma de Células de Merkel , Poliomavirus de Células de Merkel , Infecciones por Polyomavirus , Poroma , Neoplasias Cutáneas , Neoplasias de las Glándulas Sudoríparas , Humanos , Carcinoma de Células de Merkel/metabolismo , Poliomavirus de Células de Merkel/genética , Infecciones por Polyomavirus/complicaciones , Neoplasias Cutáneas/patología , Genómica
15.
Exp Dermatol ; 33(3): e15062, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38532566

RESUMEN

Merkel cell carcinoma (MCC) is a high-grade skin cancer, but spontaneous regression is observed at a markedly higher frequency than in other carcinomas. Although spontaneous regression is a phenomenon that greatly impacts treatment planning, we still cannot predict it. We previously reported on the prognostic impact of the presence or absence of tertiary lymphoid structures (TLS) and of Merkel cell polyomavirus (MCPyV) infection. To learn more about the spontaneous regression of MCC, detailed analyses were performed focusing on spontaneous regression cases. We collected 71 Japanese patients with MCC including 6 cases of spontaneous regression. Samples were analysed by immunostaining, spatial single-cell analysis using PhenoCycler, and RNA sequencing using the next-generation sequencer (NGS). All 6 cases of spontaneous regression were positive for MCPyV. TLS was positive in all 5 cases analysed. Spatial single-cell analyses revealed that PD-L1-positive tumour cells were in close proximity to CD20-positive B cell and CD3-, 4-positive T cells. Gene set enrichment analysis between MCPyV-positive and TLS-positive samples and other samples showed significantly high enrichment of "B-cell-mediated immunity" gene sets in the MCPyV-positive and TLS-positive groups. In conclusion, TLS may play an important role in the spontaneous regression of MCC.


Asunto(s)
Carcinoma de Células de Merkel , Poliomavirus de Células de Merkel , Infecciones por Polyomavirus , Neoplasias Cutáneas , Estructuras Linfoides Terciarias , Infecciones Tumorales por Virus , Humanos , Carcinoma de Células de Merkel/patología , Neoplasias Cutáneas/patología , Remisión Espontánea , Infecciones Tumorales por Virus/patología , Infecciones por Polyomavirus/patología , Poliomavirus de Células de Merkel/genética
16.
BMC Cancer ; 24(1): 785, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38951767

RESUMEN

BACKGROUND: Merkel cell carcinoma (MCC) is a rare, aggressive, cutaneous tumour with high mortality and frequently delayed diagnosis. Clinically, it often manifests as a rapidly growing erythematous to purple nodule usually located on the lower extremities or face and scalp of elderly patients. There is limited available data on the dermoscopic findings of MCC, and there are no specific features that can be used to definitively diagnose MCC. AIM OF THE STUDY: Here, we aimed to summarize existing published literature on dermatoscopic and reflectance confocal microscopy (RCM) features of MCC. MATERIALS AND METHODS: To find relevant studies, we searched the PubMed and Scopus databases from inception to April 12, 2023. Our goal was to identify all pertinent research that had been written in English. The following search strategy was employed: (" dermoscopy" OR " dermatoscopy" OR " videodermoscopy" OR " videodermatoscopy" OR " reflectance confocal microscopy") AND " Merkel cell carcinoma". Two dermatologists, DK and GE, evaluated the titles and abstracts separately for eligibility. For inclusion, only works written in English were taken into account. RESULTS: In total 16 articles were retrieved (68 cases). The main dermoscopic findings of MCC are a polymorphous vascular pattern including linear irregular, arborizing, glomerular, and dotted vessels on a milky red background, with shiny or non-shiny white areas. Pigmentation was lacking in all cases. The RCM images showed a thin and disarranged epidermis, and small hypo-reflective cells that resembled lymphocytes arranged in solid aggregates outlined by fibrous tissue in the dermis. Additionally, there were larger polymorphic hyper-reflective cells that likely represented highly proliferative cells. CONCLUSION: Dermoscopic findings of MCC may play a valuable role in evaluating MCC, aiding in the early detection and differentiation from other skin lesions. Further prospective case-control studies are needed to validate these results.


Asunto(s)
Carcinoma de Células de Merkel , Dermoscopía , Microscopía Confocal , Neoplasias Cutáneas , Carcinoma de Células de Merkel/diagnóstico por imagen , Carcinoma de Células de Merkel/patología , Humanos , Dermoscopía/métodos , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/diagnóstico por imagen , Microscopía Confocal/métodos
17.
Virol J ; 21(1): 125, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38831469

RESUMEN

BACKGROUND: Merkel Cell Carcinoma (MCC) is an aggressive skin cancer that is three times deadlier than melanoma. In 2008, it was found that 80% of MCC cases are caused by the genomic integration of a novel polyomavirus, Merkel Cell Polyomavirus (MCPyV), and the expression of its small and truncated large tumor antigens (ST and LT-t, respectively). MCPyV belongs to a family of human polyomaviruses; however, it is the only one with a clear association to cancer. METHODS: To investigate the role and mechanisms of various polyomavirus tumor antigens in cellular transformation, Rat-2 and 293A cells were transduced with pLENTI MCPyV LT-t, MCPyV ST, TSPyV ST, HPyV7 ST, or empty pLENTI and assessed through multiple transformation assays, and subcellular fractionations. One-way ANOVA tests were used to assess statistical significance. RESULTS: Soft agar, proliferation, doubling time, glucose uptake, and serum dependence assays confirmed ST to be the dominant transforming protein of MCPyV. Furthermore, it was found that MCPyV ST is uniquely transforming, as the ST antigens of other non-oncogenic human polyomaviruses such as Trichodysplasia Spinulosa-Associated Polyomavirus (TSPyV) and Human Polyomavirus 7 (HPyV7) were not transforming when similarly assessed. Identification of structural dissimilarities between transforming and non-transforming tumor antigens revealed that the uniquely transforming domain(s) of MCPyV ST are likely located within the structurally dissimilar loops of the MCPyV ST unique region. Of all known MCPyV ST cellular interactors, 62% are exclusively or transiently nuclear, suggesting that MCPyV ST localizes to the nucleus despite the absence of a canonical nuclear localization signal. Indeed, subcellular fractionations confirmed that MCPyV ST could achieve nuclear localization through a currently unknown, regulated mechanism independent of its small size, as HPyV7 and TSPyV ST proteins were incapable of nuclear translocation. Although nuclear localization was found to be important for several transforming properties of MCPyV ST, some properties were also performed by a cytoplasmic sequestered MCPyV ST, suggesting that MCPyV ST may perform different transforming functions in individual subcellular compartments. CONCLUSIONS: Together, these data further elucidate the unique differences between MCPyV ST and other polyomavirus ST proteins necessary to understand MCPyV as the only known human oncogenic polyomavirus.


Asunto(s)
Antígenos Virales de Tumores , Núcleo Celular , Poliomavirus de Células de Merkel , Poliomavirus de Células de Merkel/genética , Poliomavirus de Células de Merkel/fisiología , Humanos , Antígenos Virales de Tumores/genética , Antígenos Virales de Tumores/metabolismo , Núcleo Celular/virología , Núcleo Celular/metabolismo , Animales , Ratas , Señales de Localización Nuclear , Carcinoma de Células de Merkel/virología , Línea Celular , Neoplasias Cutáneas/virología , Neoplasias Cutáneas/patología , Transformación Celular Viral , Antígenos Transformadores de Poliomavirus/genética , Antígenos Transformadores de Poliomavirus/metabolismo , Infecciones por Polyomavirus/virología
18.
J Am Acad Dermatol ; 90(3): 569-576, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37984720

RESUMEN

BACKGROUND: Merkel cell carcinoma (MCC) recurs in 40% of patients. In addition to stage, factors known to affect recurrence risk include: sex, immunosuppression, unknown primary status, age, site of primary tumor, and time since diagnosis. PURPOSE: Create a multivariable model and web-based calculator to predict MCC recurrence risk more accurately than stage alone. METHODS: Data from 618 patients in a prospective cohort were used in a competing risk regression model to estimate recurrence risk using stage and other factors. RESULTS: In this multivariable model, the most impactful recurrence risk factors were: American Joint Committee on Cancer stage (P < .001), immunosuppression (hazard ratio 2.05; P < .001), male sex (1.59; P = .003) and unknown primary (0.65; P = .064). Compared to stage alone, the model improved prognostic accuracy (concordance index for 2-year risk, 0.66 vs 0.70; P < .001), and modified estimated recurrence risk by up to 4-fold (18% for low-risk stage IIIA vs 78% for high-risk IIIA over 5 years). LIMITATIONS: Lack of an external data set for model validation. CONCLUSION/RELEVANCE: As demonstrated by this multivariable model, accurate recurrence risk prediction requires integration of factors beyond stage. An online calculator based on this model (at merkelcell.org/recur) integrates time since diagnosis and provides new data for optimizing surveillance for MCC patients.


Asunto(s)
Carcinoma de Células de Merkel , Neoplasias Primarias Desconocidas , Neoplasias Cutáneas , Humanos , Masculino , Carcinoma de Células de Merkel/epidemiología , Carcinoma de Células de Merkel/diagnóstico , Estudios Prospectivos , Neoplasias Primarias Desconocidas/patología , Estadificación de Neoplasias , Pronóstico , Neoplasias Cutáneas/patología , Internet , Recurrencia Local de Neoplasia/epidemiología , Recurrencia Local de Neoplasia/patología , Estudios Retrospectivos
19.
J Am Acad Dermatol ; 90(2): 328-338, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37714218

RESUMEN

BACKGROUND: There are limited survival data on cutaneous angiosarcoma (CAS), dermatofibrosarcoma protuberans (DFSP), Merkel cell carcinoma (MCC), and sebaceous carcinoma (SC). OBJECTIVE: To analyze survival trends in CAS, DFSP, MCC, and SC among a racially diverse, insured cohort of patients. METHODS: Using data from the Kaiser Permanente Southern California Cancer Registry, we identified adults diagnosed with CAS, DFSP, MCC, or SC between January 1, 1988 and December 31 2018, followed through December 31, 2021. RESULTS: Our cohort consisted of 83 diagnoses of CAS, 490 diagnoses of DFSP, 411 diagnoses of MCC, and 249 diagnoses of SC. Our analysis revealed no significant differences in overall or disease-specific 1000 person-years mortality rates among our populations of non-Hispanic Whites, Hispanics, African American/Blacks, and Asian American/Pacific Islanders diagnosed with CAS, DFSP, MCC, or SC. On multivariate analysis, controlling for patient and tumor characteristics, there was similarly no increased risk of overall mortality for minorities diagnosed with CAS, DFSP, MCC, or SC. LIMITATIONS: Retrospective nature of the analysis and small sample size. CONCLUSION: Contrary to existing literature, our results show a notable lack of racially driven survival disparities among insured individuals with CAS, DFSP, MCC, and SC, emphasizing the importance of health care coverage.


Asunto(s)
Adenocarcinoma Sebáceo , Carcinoma de Células de Merkel , Dermatofibrosarcoma , Neoplasias de las Glándulas Sebáceas , Neoplasias Cutáneas , Adulto , Humanos , Estudios Retrospectivos , Dermatofibrosarcoma/patología , Neoplasias Cutáneas/diagnóstico , Carcinoma de Células de Merkel/terapia
20.
Curr Oncol Rep ; 26(9): 1120-1133, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38954315

RESUMEN

PURPOSE OF REVIEW: This review provides an update on approved and emerging systemic therapies in the treatment of locally advanced or metastatic non-melanoma skin cancers (squamous cell carcinoma, basal cell carcinoma, Merkel cell carcinoma). RECENT FINDINGS: Many studies demonstrate the effectiveness of immunotherapy for all types of non-melanoma skin cancer. For basal cell carcinoma (BCC), hedgehog inhibitors (HHI) remain first-line but with poor tolerability. Numerous clinical trials studying both neoadjuvant and adjuvant use of anti-PD-1 and anti-PD-L1 therapies in advanced NMSC are under investigation. There is a growing number of systemic therapies available to treat non-melanoma skin cancers. The advent of immunotherapy has revolutionized the field and greatly improved survival compared to historical survival rates with cytotoxic chemotherapy.


Asunto(s)
Carcinoma Basocelular , Neoplasias Cutáneas , Humanos , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/terapia , Carcinoma Basocelular/tratamiento farmacológico , Carcinoma Basocelular/patología , Carcinoma Basocelular/terapia , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/terapia , Carcinoma de Células Escamosas/patología , Carcinoma de Células de Merkel/tratamiento farmacológico , Carcinoma de Células de Merkel/terapia , Carcinoma de Células de Merkel/patología , Inmunoterapia/métodos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico
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