Inactivation of the Tumor Suppressor CYLD Sensitizes Mice to Breast Cancer Development.

BACKGROUND/AIM: Breast cancer is a leading cause of cancer-related deaths among women. Down-regulation of the tumor suppressor gene Cyld in breast cancer has been linked to a poor prognosis. This study investigated the role of Cyld in breast cancer using conditional mutant mouse models carrying a Cyld mutation, which inactivates the deubiquitinating activity of its protein product CYLD in mammary epithelial cells. MATERIALS AND METHODS: We examined the potential of CYLD inactivation to induce mammary tumors spontaneously or modify the susceptibility of mice to mammary tumorigenesis by DMBA treatment or ErbB2 over-expression. RESULTS: CYLD inactivation significantly increased susceptibility to breast cancer induced by either DMBA treatment or ErbB2 over-expression. Moreover, while CYLD inactivation alone did not lead to spontaneous mammary tumorigenesis, it did contribute to the formation of multifocal hyperplastic lesions in virgin mice of predominantly FVB/NJ background. CONCLUSION: Our study demonstrates the tumor enhancing potential of CYLD inactivation in mammary tumorigenesis in vivo and establishes novel relevant mouse models that can be exploited for developing prognostic and therapeutic protocols.

TNF and IFNγ-induced cell death requires IRF1 and ELAVL1 to promote CASP8 expression.

TNFα and IFNγ (TNF/IFNγ) synergistically induce caspase-8 activation and cancer cell death. However, the mechanism of IFNγ in promoting TNF-initiated caspase-8 activation in cancer cells is poorly understood. Here, we found that in addition to CASP8, CYLD is transcriptionally upregulated by IFNγ-induced transcription factor IRF1. IRF1-mediated CASP8 and CYLD upregulation additively mediates TNF/IFNγ-induced cancer cell death. Clinically, the expression levels of TNF, IFNγ, CYLD, and CASP8 in melanoma tumors are increased in patients responsive to immune checkpoint blockade (ICB) therapy after anti-PD-1 treatment. Accordingly, our genetic screen revealed that ELAVL1 (HuR) is required for TNF/IFNγ-induced caspase-8 activation. Mechanistically, ELAVL1 binds CASP8 mRNA and extends its stability to sustain caspase-8 expression both in IFNγ-stimulated and in basal conditions. Consequently, ELAVL1 determines death receptors-initiated caspase-8-dependent cell death triggered from stimuli including TNF and TRAIL by regulating basal/stimulated caspase-8 levels. As caspase-8 is a master regulator in cell death and inflammation, these results provide valuable clues for tumor immunotherapy and inflammatory diseases.

CYLD induces high oxidative stress and DNA damage through class I HDACs to promote radiosensitivity in nasopharyngeal carcinoma.

Abnormal expression of Cylindromatosis (CYLD), a tumor suppressor molecule, plays an important role in tumor development and treatment. In this work, we found that CYLD binds to class I histone deacetylases (HDAC1 and HDAC2) through its N-terminal domain and inhibits HDAC1 activity. RNA sequencing showed that CYLD-HDAC axis regulates cellular antioxidant response via Nrf2 and its target genes. Then we revealed a mechanism that class I HDACs mediate redox abnormalities in CYLD low-expressing tumors. HDACs are central players in the DNA damage signaling. We further confirmed that CYLD regulates radiation-induced DNA damage and repair response through inhibiting class I HDACs. Furthermore, CYLD mediates nasopharyngeal carcinoma cell radiosensitivity through class I HDACs. Thus, we identified the function of the CYLD-HDAC axis in radiotherapy and blocking HDACs by Chidamide can increase the sensitivity of cancer cells and tumors to radiation therapy both in vitro and in vivo. In addition, ChIP and luciferase reporter assays revealed that CYLD could be transcriptionally regulated by zinc finger protein 202 (ZNF202). Our findings offer novel insight into the function of CYLD in tumor and uncover important roles for CYLD-HDAC axis in radiosensitivity, which provide new molecular target and therapeutic strategy for tumor radiotherapy.

YTHDC2 Retards Cell Proliferation and Triggers Apoptosis in Papillary Thyroid Cancer by Regulating CYLD-Mediated Inactivation of Akt Signaling.

N6-Methyladenosine (m6A) mRNA methylation modification is regarded as an important mechanism involved in diverse physiological processes. YT521-B homology (YTH) domain family members are associated with the tumorigenesis of several cancers. However, the role of YTHDC2 in papillary thyroid cancer (PTC) progression remains unknown. Results showed that YTHDC1, YTHDF1, YTHDF2, and YTHDF3 showed no observable difference in thyroid cancer samples. YTHDC2 was significantly downregulated in thyroid cancer samples and cells. YTHDC2 inhibited cell proliferation in PTC cells. YTHDC2 elicited apoptosis in PTC cells, as demonstrated by the elevated expression of pro-apoptotic factors cl-caspase-3/caspase-3 and Bcl-2-associated (Bax), and the reduced anti-apoptotic B cell lymphoma-2 (Bcl-2) expression. There was a positive correlation between YTHDC2 and cylindromatosis (CYLD) expression based on GEPIA database. YTHDC2 increased CYLD expression in PTC cells. CYLD knockdown abolished the effects of YTHDC2 on PTC cell proliferation and apoptosis. Additionally, YTHDC2 inactivated the protein kinase B (Akt) pathway by increasing CYLD in PTC cells. Overall, YTHDC2 inhibited cell proliferation and induced apoptosis in PTC cells by regulating CYLD-mediated inactivation of Akt pathway.

miR-130b regulates B cell proliferation via CYLD-mediated NF-κB signaling.

Previous studies have revealed that B cell activation is regulated by various microRNAs(miRNAs). However, the role of microRNA-130b regulating B cell activation and apoptosis is still unclear. In the present study, we first found that the expression of miR-130b was the lowest in Pro/Pre-B cells and the highest in immature B cells. Besides, the expression of miR-130b decreased after activation in B cells. Through the immuno-phenotypic analysis of miR-130b transgenic and knockout mice, we found that miR-130b mainly promoted the proliferation of B cells and inhibited B cell apoptosis. Furthermore, we identified that Cyld, a tumor suppressor gene was the target gene of miR-130b in B cells. Besides, the Cyld-mediated NF-κB signaling was increased in miR-130b overexpressed B cells, which further explains the enhanced proliferation of B cells. In conclusion, we propose that miR-130b promotes B cell proliferation via Cyld-mediated NF-κB signaling, which provides a new theoretical basis for the molecular regulation of B cell activation.

Wnt/ß­catenin signaling is a novel therapeutic target for tumor suppressor CYLD­silenced glioblastoma cells.

Tumor suppressor cylindromatosis (CYLD) dysfunction by its downregulation is significantly associated with poor prognosis in patients with glioblastoma (GBM), the most aggressive and malignant type of glioma. However, no effective treatment is currently available for patients with CYLD­downregulated GBM. The aim of the present study was to identify the crucial cell signaling pathways and novel therapeutic targets for CYLD downregulation in GBM cells. CYLD knockdown in GBM cells induced GBM malignant characteristics, such as proliferation, metastasis, and GBM stem­like cell (GSC) formation. Comprehensive proteomic analysis and RNA sequencing data from the tissues of patients with GBM revealed that Wnt/ß­catenin signaling was significantly activated by CYLD knockdown in patients with GBM. Furthermore, a Wnt/ß­catenin signaling inhibitor suppressed all CYLD knockdown­induced malignant characteristics of GBM. Taken together, the results of the present study revealed that Wnt/ß­catenin signaling is responsible for CYLD silencing­induced GBM malignancy; therefore, targeting Wnt/ß­catenin may be effective for the treatment of CYLD­negative patients with GBM with poor prognosis.

Expanding CYLD protein in NF-κß/TNF-α signaling pathway in response to Lactobacillus acidophilus in non-metastatic rectal cancer patients.

The CYLD gene is a tumor suppressor, reduced in many cancers. Here, we aimed to investigate CYLD protein level and NF-κß/TNF-α signaling pathway in rectal cancer patients with Lactobacillus acidophilus (L. acidophilus) consumption. One hundred ten patients with non-metastatic rectal cancer were randomly divided into L. acidophilus probiotic (500 mg, three times daily) and placebo groups for 13 weeks. The expression of CYLD, TNF-α, and NF-κB proteins and the genes involved in the NF-κß/TNF-α pathway were evaluated using ELISA and qPCR techniques. The survival rate was measured after five years. Unlike the placebo group, the results showed a significant increase in the expression of CYLD protein and tumor suppressor genes, including FOXP3, ROR-γ, Caspase3, GATA3, T-bet, and a considerable decrease in the expression of NF-Òß and TNF-α proteins and oncogenes, including STAT3, 4, 5, 6, and SMAD 3, in the probiotic group. A higher overall survival rate was seen after L. acidophilus consumption compared to the placebo group (P < 0.05). L. acidophilus consumption can reduce inflammation factors by affecting CYLD protein and its downstream signaling pathways. A schematic plot of probiotic consumption Effects on the CYLD protein in regulating the NF-Ä¸ß signaling pathway in colorectal cancer. NF-Ä¸ß can be activated by canonical and noncanonical pathways, which rely on IκB degradation and p100 processing, respectively. In the canonical NF-κß pathway, dimmers, such as p65/p50, are maintained in the cytoplasm by interacting with an IκBα protein. The binding of a ligand to a cell-surface receptor activates TRAF2, which triggers an IKK complex, containing -α, -ß, -g, which phosphorylates IKK-ß. It then phosphorylates IκB-α, leading to K48-ubiquitination and degradation of this protein. The p65/p50 protein freely enters the nucleus to turn on target genes. The non-canonical pathway is primarily involved in p100/RelB activation. It differs from the classical pathway in that only certain receptor signals activate this pathway. It proceeds through an IKK complex that contains two IKK-α subunits but not NEMO. Several materials including peptidoglycan, phorbol, myristate, acetate, and gram-positive bacteria such as probiotics inhibit NF-κB by inducing CYLD. This protein can block the canonical and noncanonical NF-κß pathways by removing Lys-63 ubiquitinated chains from activated TRAFs, RIP, NEMO, and IKK (α, ß, and γ). Moreover, TNF-α induces apoptosis by binding caspase-3 to FADD.

Multiple brain regions are involved in reaction to acute restraint stress in CYLD-knockout mice.

The lysine 63 deubiquitinase cylindromatosis (CYLD) is expressed at high levels in the brain and is considered to be involved in anxious and depressive behavior, cognitive inflexibility, and autism disorders. Previous research was limited in some brain regions, including the hippocampus, striatum, and amygdala. To better understand whether CYLD plays a role in adaptation to stress and which brain regions are involved, we analyzed the behavior of CYLD-knockout mice in the elevated plus maze (EPM) and light-dark box test (LDT) after acute restraint stress (ARS) and mapped their c-Fos immunoreactivity in brain sections. Here we report that CYLD deficiency leads to an unexpected reaction to ARS in mice, and is accompanied by significant neuronal activation of brain regions including the medial prefrontal cortex (mPFC), dorsal striatum (DS), nucleus accumbens (NAc), and basal lateral amygdala (BLA), but not ventral hippocampus (vHPC). Our findings show that CYLD participates in ARS-induced anxious behavior and that this involves multiple brain regions.

CYLD in health and disease.

CYLD lysine 63 deubiquitinase (CYLD) is a ubiquitin hydrolase with important roles in immunity and cancer. Complete CYLD ablation, truncation and expression of alternate isoforms, including short CYLD, drive distinct phenotypes and offer insights into CYLD function in inflammation, cell death, cell cycle progression and cell transformation. Research in diverse model systems has shown that these are mediated via CYLD regulation of cellular pathways including the NF-κB, Wnt and TGF-ß pathways. Recent biochemical advances and models have offered new insights into the regulation and function of CYLD. In addition, recent discoveries of gain-of-function germline pathogenic CYLD variants in patients with a neurodegenerative phenotype contrast with the more widely known loss-of-function mutations seen in patients with CYLD cutaneous syndrome and with sporadic cancers. Here, we provide a current review of mechanistic insights into CYLD function gained from CYLD animal models, as well as an update on the role of CYLD in human disease.

Cylindroma of the breast with CYLD gene mutation: a case report and review of the literature.

BACKGROUND: Cylindroma of the breast is a rare benign neoplasm. Since its first description in 2001, 20 cases have been reported in the literature. METHODS AND RESULTS: We report another case of this rare tumor in a 60-year-old woman with demonstration of the underlying molecular alteration. Histologically, the tumor showed the typical "jigsaw" pattern of a dual population of cells with a triple-negative phenotype. The pathognomonic mutation of the CYLD gene mutation was detected by whole exome sequencing. Cylindromas show morphological overlap with the solid-basaloid variant of adenoid cystic carcinoma, which renders this differential diagnosis difficult. However, distinction of these two lesions is of outmost importance, since cylindromas, in contrast to solid-basaloid variant of adenoid cystic carcinoma, behave in an entirely benign fashion. CONCLUSIONS: Careful evaluation of morphological features such as mitotic figures and cellular atypia is crucial in the diagnostic work-up of triple-negative breast lesions. It is important to keep cylindroma in mind as a pitfall and possible differential diagnosis for the solid-basaloid variant of adenoid cystic carcinoma. Molecular detection of CYLD gene mutation is helpful in cases with ambiguous histology. With this case report, we aim to contribute to a better understanding of mammary cylindroma and facilitate the diagnosis of this rare entity.

The Potential of Cylindromatosis (CYLD) as a Therapeutic Target in Oxidative Stress-Associated Pathologies: A Comprehensive Evaluation.

Oxidative stress (OS) arises as a consequence of an imbalance between the formation of reactive oxygen species (ROS) and the capacity of antioxidant defense mechanisms to neutralize them. Excessive ROS production can lead to the damage of critical biomolecules, such as lipids, proteins, and DNA, ultimately contributing to the onset and progression of a multitude of diseases, including atherosclerosis, chronic obstructive pulmonary disease, Alzheimer's disease, and cancer. Cylindromatosis (CYLD), initially identified as a gene linked to familial cylindromatosis, has a well-established and increasingly well-characterized function in tumor inhibition and anti-inflammatory processes. Nevertheless, burgeoning evidence suggests that CYLD, as a conserved deubiquitination enzyme, also plays a pivotal role in various key signaling pathways and is implicated in the pathogenesis of numerous diseases driven by oxidative stress. In this review, we systematically examine the current research on the function and pathogenesis of CYLD in diseases instigated by oxidative stress. Therapeutic interventions targeting CYLD may hold significant promise for the treatment and management of oxidative stress-induced human diseases.

MALT1-dependent cleavage of CYLD promotes NF-κB signaling and growth of aggressive B-cell receptor-dependent lymphomas.

The paracaspase mucosa-associated lymphoid tissue 1 (MALT1) is a protease and scaffold protein essential in propagating B-cell receptor (BCR) signaling to NF-κB. The deubiquitinating enzyme cylindromatosis (CYLD) is a recently discovered MALT1 target that can negatively regulate NF-κB activation. Here, we show that low expression of CYLD is associated with inferior prognosis of diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) patients, and that chronic BCR signaling propagates MALT1-mediated cleavage and, consequently, inactivation and rapid proteasomal degradation of CYLD. Ectopic overexpression of WT CYLD or a MALT1-cleavage resistant mutant of CYLD reduced phosphorylation of IκBα, repressed transcription of canonical NF-κB target genes and impaired growth of BCR-dependent lymphoma cell lines. Furthermore, silencing of CYLD expression rendered BCR-dependent lymphoma cell lines less sensitive to inhibition of NF-κΒ signaling and cell proliferation by BCR pathway inhibitors, e.g., the BTK inhibitor ibrutinib, indicating that these effects are partially mediated by CYLD. Taken together, our findings identify an important role for MALT1-mediated CYLD cleavage in BCR signaling, NF-κB activation and cell proliferation, which provides novel insights into the underlying molecular mechanisms and clinical potential of inhibitors of MALT1 and ubiquitination enzymes as promising therapeutics for DLBCL, MCL and potentially other B-cell malignancies.

CYLD inhibits osteoclastogenesis to ameliorate alveolar bone loss in mice with periodontitis.

Periodontitis is a chronic immune inflammatory disease that can lead to the destruction and loss of the tooth-supporting apparatus. During this process, the balance between bone absorption mediated by osteoclasts and bone formation mediated by osteoblasts is damaged. Consistent with previous studies, we observed that depletion of cylindromatosis (CYLD) resulted in an osteoporotic bone phenotype. However, the effect of CYLD deficiency on periodontitis is undetermined. Here, we investigated whether CYLD affects periodontal tissue homeostasis in experimental periodontitis in Cyld knockout (KO) mice, and we explored the underlying mechanisms. Interestingly, we discovered significant alveolar bone density loss and severely reduced alveolar bone height in Cyld KO mice with experimentally induced periodontitis. We observed increased osteoclast number and activity in both the femurs and alveolar bones, accompanied by the downregulation of osteogenesis genes and upregulation of osteoclastogenesis genes of alveolar bones in ligatured Cyld KO mice. Taken together, our findings demonstrate that the deletion of CYLD in mice plays a vital role in the pathogenesis of periodontal bone loss and suggest that CYLD might exert an ameliorative effect on periodontal inflammatory responses.

Deubiquitinase cylindromatosis (CYLD) regulates antibacterial immunity and apoptosis in Chinese mitten crab (Eriocheir sinensis).

Ubiquitination and deubiquitination of target proteins is an important mechanism for cells to rapidly respond to changes in the external environment. The deubiquitinase, cylindromatosis (CYLD), is a tumor suppressor protein. CYLD from Drosophila melanogaster participates in the antimicrobial immune response. In vertebrates, CYLD also regulates bacterial-induced apoptosis. However, whether CYLD can regulate the bacterial-induced innate immune response in crustaceans is unknown. In the present study, we reported the identification and cloning of CYLD in Chinese mitten crab, Eriocheir sinensis. Quantitative real-time reverse transcription polymerase chain reaction analysis showed that EsCYLD was widely expressed in all the examined tissues and was upregulated in the hemolymph after Vibrio parahaemolyticus challenge. Knockdown of EsCYLD in hemocytes promoted the cytoplasm-to-nucleus translocation of transcription factor Relish under V. parahaemolyticus stimulation and increased the expression of corresponding antimicrobial peptides. In vivo, silencing of EsCYLD promoted the removal of bacteria from the crabs and enhanced their survival. In addition, interfering with EsCYLD expression inhibited apoptosis of crab hemocytes caused by V. parahaemolyticus stimulation. In summary, our findings revealed that EsCYLD negatively regulates the nuclear translocation of Relish to affect the expression of corresponding antimicrobial peptides and regulates the apoptosis of crab hemocytes, thus indirectly participating in the innate immunity of E. sinensis.

The expression of miR-181b, CYLD, CBX-7, BCL2, and p53 in osteosarcoma patients and correlation with clinicopathological factors.

Osteosarcoma is a common human malignancy with a high mortality rate worldwide. Recent studies have been focused on understanding the involvement of microRNA (miRNAs) in the pathogenesis of osteosarcoma. Therefore, the present study aimed to measure the expression levels of miR-181a, cylindromatosis (CYLD), chromo box homolog 7 (CBX7), B-cell lymphoma 2 (BCL2), and tumor protein p53 in tumor tissue and adjacent normal tissues in patients with osteosarcoma and its relationship with clinicopathological factors. The expression levels of miR-181a, CYLD, CBX7, BCL2, and p53 were measured in 60 patients with osteosarcoma using quantitative real-time polymerase chain reaction. Finally, we compared the relationship between these gene levels and clinicopathological factors in tumor and healthy tissues. Our results showed that the expression levels of miR-181a, BCL2, and p53 were significantly higher in osteosarcoma tissue in comparison with normal tissues (p < .05). On the contrary, CYLD and CBX7 were downregulated in osteosarcoma tumor tissues compared to adjacent healthy tissues (p < .05). In addition, the expression levels of miR-181a in tumor tissues were strongly correlated with patients' age, tumor size, clinical stage, cancer grade, and lymph node metastasis (p < .05). Our findings highlight new insights into understanding the role of miR-181a in the pathogenesis of osteosarcoma. However, further studies are needed to elucidate miRNA as therapeutic targets for osteosarcoma.

Spata2L Suppresses TLR4 Signaling by Promoting CYLD-Mediated Deubiquitination of TRAF6 and TAK1.

Toll-like receptor 4 (TLR4) is a key pattern recognition receptor that can be activated by bacterial lipopolysaccharide to elicit inflammatory response. Proper activation of TLR4 is critical for the host defense against microbial infections. Since overactivation of TLR4 causes deleterious effects and inflammatory diseases, its activation needs to be tightly controlled by negative regulatory mechanisms, among which the most pivotal could be deubiquitination of key signaling molecules mediated by deubiquitinating enzymes (DUBs). CYLD is a member of the USP family of DUBs that acts as a critical negative regulator of TLR4-depedent inflammatory responses by deconjugating polyubiquitin chains from signaling molecules, such as TRAF6 and TAK1. Dysregulation of CYLD is implicated in inflammatory diseases. However, how the function of CYLD is regulated during inflammatory response remains largely unclear. Recently, we and other authors have shown that Spata2 functions as an important CYLD partner to regulate enzymatic activity of CYLD and substrate binding by this protein. Here, we show that a Spata2-like protein, Spata2L, can also form a complex with CYLD to inhibit the TLR4-dependent inflammatory response. We found that Spata2L constitutively interacts with CYLD and that the deficiency of Spata2L enhances the LPS-induced NF-κB activation and proinflammatory cytokine gene expression. Mechanistically, Spata2L potentiated CYLD-mediated deubiquitination of TRAF6 and TAK1 likely by promoting CYLD enzymatic activity. These findings identify Spata2L as a novel CYLD regulator, provide new insights into regulatory mechanisms underlying CYLD role in TLR4 signaling, and suggest potential targets for modulating TLR4-induced inflammation.

Oxidative stress-induced lncRNA CYLD-AS1 promotes RPE inflammation via Nrf2/miR-134-5p/NF-κB signaling pathway.

Oxidative stress-induced damage to and dysfunction of retinal pigment epithelium (RPE) cells are important pathogenetic factors of age-related macular degeneration (AMD); however, the underlying molecular mechanism is not fully understood. Long noncoding RNAs (lncRNAs) have important roles in various biological processes. In this study, using an oxidative damage model in RPE cells, we identified a novel oxidation-related lncRNA named CYLD-AS1. We further revealed that the expression of CYLD-AS1 was increased in RPEs during oxidative stress. Depletion of CYLD-AS1 promoted cell proliferation and mitochondrial function and protected RPE cells against hydrogen peroxide (H2 O2 )-induced damage. Mechanistically, CYLD-AS1 also regulated the expression of NRF2, which is related to oxidative stress, and NF-κB signaling pathway members, which are related to inflammation. Remarkably, these two signaling pathways were mediated by the CYLD-AS1 interactor miR-134-5p. Moreover, exosomes secreted by CYLD-AS1 knockdown RPE cells had a lower proinflammatory effect than those secreted by control cells. In summary, our study revealed that CYLD-AS1 affects the oxidative stress-related and inflammatory functions of RPE cells by sponging miR-134-5p to mediate NRF2/NF-κB signaling pathway activity, suggesting that targeting CYLD-AS1 could be a promising strategy for the treatment of AMD and related diseases.

CYLD variants identified in Alzheimer's disease and frontotemporal dementia patients.

OBJECTIVES: CYLD was a novel causative gene for frontotemporal dementia (FTD) and amyotrophic lateral sclerosis. Given the clinical and pathological overlap of FTD and Alzheimer's disease (AD), it is necessary to screen CYLD in AD patients and FTD patients in the Chinese population. METHODS: In our study, using a targeted sequencing panel, we sequenced the CYLD gene in a large cohort of 2485 participants in the Chinese population, including 1008 AD patients, 105 FTD patients, and 1372 controls. RESULTS: In the present study, the average onset age of AD and FTD patients was 66.84 ± 30.42 years old and 60 ± 10.00 years old, respectively. Our study reported three novel CYLD variants: p.Phe288Leu (patient No. 1, AD), p.Tyr485Phe (patients No. 6-9, all AD) and p.Thr951Ala (patient No. 10, AD), plus a previously reported variant: p.Arg397Ser (patient No. 2-5, AD and No. 11, FTD). These variants were absent in our in-house controls and predicted to be deleterious according to the MutationTaster. The variant carriers were composed of 10 AD patients and one FTD patient, and the average onset age was 61.2 ± 10.9 years. The frequency of CYLD variants in AD was similar to that in FTD, which was 0.99% (10/1008) and 0.95% (1/105), respectively. INTERPRETATION: Our finding extended the genotype and phenotype of the CYLD gene and demonstrated that CYLD rare damaging variants may be implicated in AD and FTD pathogenesis.

CYLD expression in endometrial carcinoma and correlation with clinicohistopathological parameters.

OBJECTIVE: Endometrial cancer is a threat to women health worldwide. Cylindromatosis (CYLD) enzyme is a tumour suppressor, considered an effective prognostic marker in various malignancies, but its role in endometrial carcinoma is not fully elucidated. Here, we sought to estimate the prognostic value of CYLD expression in endometrial carcinoma. MATERIALS AND METHODS: CYLD levels were immunohistochemically evaluated in 65 patients with endometrial carcinoma and inferential statistics were applied. RESULTS: Low or negative CYLD expression significantly correlates with older ages, non-endometrioid and invasive carcinomas, tumours with moderate or poor differentiation and advanced stages. Moreover, non-endometrioid and invasive carcinomas are independent risk factors for weaker CYLD expression. Kaplan-Meier analysis illustrated that negative or low CYLD expression is statistically significantly associated with increased death risk, compared to moderate or high expression. CONCLUSION: This study demonstrates for the first time a clear correlation between CYLD expression and clinicohistopathological parameters of endometrial carcinoma patients, suggesting its use as a potential prognostic/predictive marker for Endometrial Carcinoma.

NF-κB over-activation portends improved outcomes in HPV-associated head and neck cancer.

Evolving understanding of head and neck squamous cell carcinoma (HNSCC) is leading to more specific diagnostic disease classifications. Among HNSCC caused by the human papilloma virus (HPV), tumors harboring defects in TRAF3 or CYLD are associated with improved clinical outcomes and maintenance of episomal HPV. TRAF3 and CYLD are negative regulators of NF-κB and inactivating mutations of either leads to NF-κB overactivity. Here, we developed and validated a gene expression classifier separating HPV+ HNSCCs based on NF-κB activity. As expected, the novel classifier is strongly enriched in NF-κB targets leading us to name it the NF-κB Activity Classifier (NAC). High NF-κB activity correlated with improved survival in two independent cohorts. Using NAC, tumors with high NF-κB activity but lacking defects in TRAF3 or CYLD were identified; thus, while TRAF3 or CYLD gene defects identify the majority of tumors with NF-κB activation, unknown mechanisms leading to NF-kB activity also exist. The NAC correctly classified the functional consequences of two novel CYLD missense mutations. Using a reporter assay, we tested these CYLD mutations revealing that their activity to inhibit NF-kB was equivalent to the wild-type protein. Future applications of the NF-κB Activity Classifier may be to identify HPV+ HNSCC patients with better or worse survival with implications for treatment strategies.