Role of MEK1 and DIAPH3 expression in colorectal adenoma-carcinoma sequence.

BACKGROUND: It is well established that most colorectal carcinomas arise from conventional adenomas through the adenoma-carcinoma sequence (ACS) model. mitogen-activated protein kinases (MAPKs) pathway has been reported as a crucial player in tumorigenesis. The MAPK signaling pathway is activated by different extracellular signals involving the "mitogen-activated/extracellular signal-regulated kinase 1 (MEK1)", and this induces the expression of genes involved in proliferation and cellular transformation. Diaphanous-related formin-3 (DIAPH3) acts as a potential metastasis regulator through inhibiting the cellular transition to amoeboid behavior in different cancer types. OBJECTIVE: The aim of the study was to investigate the pattern of immunohistochemical expression of MEK1 and DIAPH3 in colorectal adenoma (CRA) and corresponding colorectal carcinoma (CRC) specimens. METHODS: The immunohistochemical expression of DIAPH3 and MEK1 was examined in 43 cases of CRC and their associated adenomas using tissue microarray technique. RESULTS: MEK1 was overexpressed in 23 CRC cases (53.5%) and in 20 CRA cases (46.5%). DIAPH3 was overexpressed in 11 CRA cases (about 29%) which were significantly lower than CRC (22 cases; 58%) (P = 0.011). Both MEK1 and DIAPH3 overexpression were significantly correlated in CRC (P = 0.009) and CRA cases (P = 0.002). Tumors with MEK1 overexpression had a significantly higher tumor grade (P = 0.050) and perineural invasion (P = 0.017). CONCLUSIONS: Both MEK1 and DIAPH3 are overexpressed across colorectal ACS with strong correlation between them. This co- expression suggests a possible synergistic effect of MEK1 and DIAPH-3 in colorectal ACS. Further large-scale studies are required to investigate the potential functional aspects of MEK1 and DIAPH3 in ACS and their involvement in tumor initiation and the metastatic process.

Brd4::Nutm1 fusion gene initiates NUT carcinoma in vivo.

NUT carcinoma (NC) is an aggressive cancer with no effective treatment. About 70% of NUT carcinoma is associated with chromosome translocation events that lead to the formation of a BRD4::NUTM1 fusion gene. Because the BRD4::NUTM1 gene is unequivocally cytotoxic when ectopically expressed in cell lines, questions remain on whether the fusion gene can initiate NC. Here, we report the first genetically engineered mouse model for NUT carcinoma that recapitulates the human t(15;19) chromosome translocation in mice. We demonstrated that the mouse t(2;17) syntenic chromosome translocation, forming the Brd4::Nutm1 fusion gene, could induce aggressive carcinomas in mice. The tumors present histopathological and molecular features similar to human NC, with enrichment of undifferentiated cells. Similar to the reports of human NC incidence, Brd4::Nutm1 can induce NC from a broad range of tissues with a strong phenotypical variability. The consistent induction of poorly differentiated carcinoma demonstrated a strong reprogramming activity of BRD4::NUTM1. The new mouse model provided a critical preclinical model for NC that will lead to better understanding and therapy development for NC.

dsRNAi-mediated silencing of PIAS2beta specifically kills anaplastic carcinomas by mitotic catastrophe.

The E3 SUMO ligase PIAS2 is expressed at high levels in differentiated papillary thyroid carcinomas but at low levels in anaplastic thyroid carcinomas (ATC), an undifferentiated cancer with high mortality. We show here that depletion of the PIAS2 beta isoform with a transcribed double-stranded RNA-directed RNA interference (PIAS2b-dsRNAi) specifically inhibits growth of ATC cell lines and patient primary cultures in vitro and of orthotopic patient-derived xenografts (oPDX) in vivo. Critically, PIAS2b-dsRNAi does not affect growth of normal or non-anaplastic thyroid tumor cultures (differentiated carcinoma, benign lesions) or cell lines. PIAS2b-dsRNAi also has an anti-cancer effect on other anaplastic human cancers (pancreas, lung, and gastric). Mechanistically, PIAS2b is required for proper mitotic spindle and centrosome assembly, and it is a dosage-sensitive protein in ATC. PIAS2b depletion promotes mitotic catastrophe at prophase. High-throughput proteomics reveals the proteasome (PSMC5) and spindle cytoskeleton (TUBB3) to be direct targets of PIAS2b SUMOylation at mitotic initiation. These results identify PIAS2b-dsRNAi as a promising therapy for ATC and other aggressive anaplastic carcinomas.

Effective detection of BRAFV595E mutation in canine urothelial and prostate carcinomas using immunohistochemistry.

Canine urothelial carcinoma (UC) and prostate carcinoma (PC) frequently exhibit the BRAFV595E mutation, akin to the BRAFV600E mutation common in various human cancers. Since the initial discovery of the BRAF mutation in canine cancers in 2015, PCR has been the standard method for its detection in both liquid and tissue biopsies. Considering the similarity between the canine BRAFV595E and human BRAFV600E mutations, we hypothesized that immunohistochemistry (IHC) using a BRAFV600E-specific antibody could effectively identify the canine mutant BRAFV595E protein. We tested 122 canine UC (bladder n = 108, urethra n = 14), 21 PC, and benign tissue using IHC and performed digital droplet PCR (ddPCR) on all 122 UC and on 14 IHC positive PC cases. The results from ddPCR and IHC were concordant in 99% (135/136) of the tumours. Using IHC, BRAFV595E was detected in 72/122 (59%) UC and 14/21 (65%) PC. Staining of all benign bladder and prostate tissues was negative. If present, mutant BRAF staining was homogenous, with rare intratumour heterogeneity in three (4%) cases of UC. Additionally, the BRAFV595E mutation was more prevalent in tumours with urothelial morphology, and less common in glandular PC or UC with divergent differentiation. This study establishes that BRAFV600-specific IHC is a reliable and accurate method for detecting the mutant BRAFV595E protein in canine UC and PC. Moreover, the use of IHC, especially with tissue microarrays, provides a cost-efficient test for large-scale screening of canine cancers for the presence of BRAF mutations. This advancement paves the way for further research to define the prognostic and predictive role of this tumour marker in dogs and use IHC to stratify dogs for the treatment with BRAF inhibitors.

Single nucleotide polymorphism (SNP) chromosomal microarray as a diagnostic tool for mucinous tubular and spindle cell carcinoma: A validation study.

Mucinous tubular and spindle cell carcinoma (MTSCC) shows significant overlap with papillary renal cell carcinoma (PRCC), and harbor recurrent copy-number alterations (CNA). We evaluated 16 RCC with features suggestive of MTSCC using chromosomal microarrays. The cohort was comprised of 8 females and males, each, with an age range of 33-79 years (median, 59), and a tumor size range of 3.4-15.5 cm (median, 5.0). Half the tumors were high-grade (8/16, 50%) with features such as necrosis, marked cytologic atypia, and sarcomatoid differentiation, and 5/16 (31%) were high stage (≥pT3a). Three (of 16, 19%) cases had a predominant (>95%) spindle cell component, whereas 5/16 (31%) were composed of a predominant (>95%) epithelial component. Most cases (12/16, 75%) exhibited a myxoid background and/or extravasated mucin, at least focally. Twelve (of 16, 75%) cases demonstrated CNA diagnostic of MTSCC (losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22). In addition, 2 high-grade tumors showed loss of CDKN2A/B, and gain of 1q, respectively, both of which are associated with aggressive behavior. Three (of 16, 19%) cases, demonstrated nonspecific CNA, and did not meet diagnostic criteria for established RCC subtypes. One (of 16, 6%) low-grade epithelial predominant tumor (biopsy) demonstrated characteristic gains of 7, 17, and loss of Y, diagnostic of PRCC. MTSCC can be a morphologically heterogenous tumor. Our study validates the detection of characteristic chromosomal CNA for diagnostic use that may be useful in challenging cases with unusual spindle cell or epithelial predominant features, as well as in high-grade tumors.

Primary cutaneous NUT carcinoma with BRD4::NUTM1 fusion.

Nuclear protein in testis (NUT) carcinoma, molecularly defined by the NUTM1 gene rearrangement, is most commonly reported in young adults in the sinonasal tract, nasopharynx, or thorax. At these sites, NUT carcinoma is an extremely aggressive malignancy with dismal prognosis. Recently, five cases of primary cutaneous NUT adnexal carcinoma have been reported with BRD3 and NSD3 fusion partners. Although NUT adnexal carcinomas are shown to have metastatic potential, they may behave less aggressively than extracutaneous NUT carcinomas. We report a case of a 59-year-old man who underwent a biopsy of a 3-cm plantar mass, which showed BRD4::NUTM1 fusion. The tumor was a poorly differentiated dermal neoplasm showing cytologic atypia, large vesicular nuclei with prominent nucleoli, conspicuous mitotic activity, and foci of necrosis. Immunohistochemically, the tumor showed positivity for keratins, EMA, SOX10, and NUT, with patchy smooth muscle actin. Molecular testing revealed BRD4::NUTM1 rearrangement. With no alternative primary identified by imaging, a diagnosis of primary cutaneous NUT carcinoma was favored. We hope to contribute to the limited body of knowledge on this entity, with emphasis on recognition as well as studying and defining its prognostic differences from extracutaneous NUT carcinomas.

Relationship between ERCC1 and XPC polymorphisms and the susceptibility to head and neck carcinoma: A systematic review, meta-analysis, and trial sequential analysis.

OBJECTIVE: This meta-analysis was conducted to investigate the relationship between ERCC1 and XPC polymorphisms and the risk of head and neck cancer (HNC), incorporating more studies and additional analyses. DESIGN: An exhaustive search of various databases, including PubMed/Medline, Web of Science, Scopus, and Cochrane Library was carried out, up until November 18, 2023, to identify pertinent studies. The Review Manager 5.3 software was employed to calculate the effect sizes, which were presented as the odds ratio (OR) along with a 95% confidence interval (CI). RESULTS: The study found that the T allele (OR = 1.11; p-value = 0.02; 95%CI: 1.02, 1.22) and the TT genotype rs2228000 polymorphism in both the homozygous model (OR = 1.61, p-value = 0.02; 95%CI: 1.07, 2.42) and the recessive model (OR = 1.53; p-value = 0.02; 95%CI: 1.06, 2.22) had statistically significant associations. However, no significant associations were found for rs11615, rs3212986, rs735482, rs2228001, and PAT polymorphisms in any genetic models. CONCLUSIONS: The meta-analysis revealed significant associations for the T allele and TT genotype rs2228000 polymorphism, but not for rs11615, rs3212986, rs735482, rs2228001, and PAT polymorphisms. The results highlight the impact of factors such as ethnicity, cancer subtype, and control source on these associations, emphasizing the intricate nature of genetic interactions in disease risk.

Clinical responses to vemurafenib in postoperative recurrence of papillary thyroid carcinoma with esophageal fistula: A case report.

BACKGROUND: While papillary thyroid carcinoma (PTC) generally exhibits a favorable prognosis post-surgery, the poorly differentiated subtype presents elevated rates of postoperative recurrence. Certain aggressive cases demonstrate invasive behavior, compromising adjacent structures and leading to a poor prognosis. This study delineates a unique case of postoperative PTC recurrence, complicated by esophageal fistula, that showed favorable outcomes following brief Vemurafenib treatment. PATIENT DESCRIPTION: A 64-year-old female patient underwent surgical resection for PTC, subsequently experiencing rapid tumor recurrence and development of an esophageal fistula. DIAGNOSIS: The patient was confirmed to have locally advanced PTC through intraoperative cytopathology. The cancer recurred postoperatively, culminating in the formation of an esophageal fistula. METHODS: The patient was administered Vemurafenib at a dosage of 960 mg twice daily following tumor recurrence. RESULTS: A 12-month regimen of targeted Vemurafenib therapy led to a substantial reduction in tumor size. Concurrently, the esophageal fistula underwent complete healing, facilitating successful removal of the gastrostomy tube. The tumor response was classified as stable disease. CONCLUSION SUBSECTIONS: Vemurafenib demonstrates potential as a targeted therapeutic strategy for recurrent PTC harboring the BRAFV600E mutation. This approach may effectively mitigate tumor dimensions and the associated risk of esophageal and tracheal fistulas.

Immunotherapy experience in sinonasal NUT midline carcinoma, case report.

NUT midline carcinoma (NMC) is an aggressive malignant neoplasm arising from midline structures. Although it is classified as a rare disease, the pathological nonspecific appearance as undifferentiated/poorly differentiated carcinoma and the difficulty in making the definitive diagnosis are probably the reasons for the underdiagnosis; the disease is thought to be more prevalent. There is no standard treatment for the disease. The disease shows a poor response to chemotherapy and radiotherapy, and patients' survival is poor. We present a case of sinonasal NMC treated with chemotherapy and immunotherapy in first-line, which is the first in the literature. The patient presented with metastatic disease and received cisplatin-fluorouracil-docetaxel-pembrolizumab treatment. The tumor's PD-L1 expression was 10%, evaluated by tumor proportion score. The response to the therapy was poor, and the patient died of disease progression 5.4 months after the diagnosis. The efficacy of immunotherapy in NMC is not known. More reports are needed to draw conclusions.

PKM2 promotes lymphatic metastasis of hypopharyngeal carcinoma via regulating epithelial-mesenchymal transition: an experimental research.

BACKGROUND: Patients with hypopharyngeal carcinoma (HPC) have a poor prognosis mainly because of lymphatic metastasis. This research aimed to determine the PKM2 role in lymphatic metastasis in HPC and the underlying molecular mechanism contributing to this phenomenon. METHODS: PKM2 in HPC was studied for its expression and its likelihood of overall survival using TCGA dataset. Western blotting, qRT-PCR, and IHC were employed to confirm PKM2 expression. Methods including gain- and loss-of-function were used to examine the PKM2 role in HPC metastasis in vitro and in vivo. In vitro and in vivo studies also confirmed lymphatic metastasis's mechanism. RESULTS: Prominent PKM2 overexpression was seen in patients with lymphatic metastasis of HPC, and there was an inherent relationship between a high PKM2 level and poor prognosis. In vitro research showed that knocking down PKM2 decreased tumor cell invasion, migration, and proliferation while promoting apoptosis and inhibiting epithelial-mesenchymal transition, but overexpressing PKM2 had the reverse effect. Animal studies suggested that PKM2 may facilitate tumor development and lymphatic metastasis. CONCLUSIONS: Our findings suggest that PKM2 may be a tumor's promoter gene of lymphatic metastasis, which may promote lymphatic metastasis of HPC by regulating epithelial-mesenchymal transition. PKM2 may be a biomarker of metastatic potential, ultimately providing a basis for exploring new therapeutic targets.

Dysregulation and antimetastatic function of circLRIG1 modulated by miR-214-3p/LRIG1 axis in bladder carcinoma.

CircLRIG1, a newly discovered circRNA, has yet to have its potential function and biological processes reported. This study explored the role of circLRIG1 in the development and progression of bladder carcinoma and its potential molecular mechanisms. Techniques such as qRT-PCR, Western blot, various cellular assays, and in vivo models were used to investigate mRNA and protein levels, cell behavior, molecular interactions, and tumor growth. The results showed that both circLRIG1 and LRIG1 were significantly reduced in bladder carcinoma tissues and cell lines. Low circLRIG1 expression was associated with poor patient prognosis. Overexpressing circLRIG1 inhibited bladder carcinoma cell growth, migration, and invasion, promoted apoptosis, and decreased tumor growth and metastasis in vivo. Importantly, circLRIG1 was found to sponge miR-214-3p, enhancing LRIG1 expression, and its overexpression also modulated protein levels of E-cadherin, N-cadherin, Vimentin, and LRIG1. Similar effects were observed with LRIG1 overexpression. Notably, a positive correlation was found between circLRIG1 and LRIG1 expression in bladder carcinoma tissues. Additionally, the tumor-suppressing effect of circLRIG1 was reversed by overexpressing miR-214-3p or silencing LRIG1. The study concludes that circLRIG1 suppresses bladder carcinoma progression by enhancing LRIG1 expression via sponging miR-214-3p, providing a potential strategy for early diagnosis and treatment of bladder carcinoma.

Comparative analysis of ARID1A mutations with mRNA levels and protein expression in gastric carcinoma.

The ARID1A gene is pivotal in chromatin remodeling and genomic integrity and is frequently mutated in various cancer types. ARID1A mutation is the second most frequently mutated tumor suppressor gene and has been suggested as a predictor of immunotherapeutic responsiveness in gastric carcinoma (GC). Despite its significance, the relationship among ARID1A somatic mutations, RNA expression levels, and protein expression remains unclear, particularly in GC. For this purpose, we performed comparative study in two cohorts. Cohort 1 used next-generation sequencing (NGS) to identify 112 GC cases with ARID1A mutations. These cases were compared with ARID1A immunohistochemistry (IHC) results. Cohort 2 employed microarray gene expression data to assess ARID1A RNA levels and compare them with ARID1A IHC results. In Cohort 1, 38.4% of ARID1A-mutated GC exhibited a complete loss of ARID1A protein when assessed by IHC, whereas the remaining 61.6% displayed intact ARID1A. Discordance between NGS and IHC results was not associated with specific mutation sites, variant classifications, or variant allele frequencies. In Cohort 2, 24.1% of the patients demonstrated a loss of ARID1A protein, and there was no significant difference in mRNA levels between the ARID1A protein-intact and -loss groups. Our study revealed a substantial discrepancy between ARID1A mutations detected using NGS and protein expression assessed using IHC in GC. Moreover, ARID1A mRNA expression levels did not correlate well with protein expression. These findings highlighted the complexity of ARID1A expression in GC.

LGALS3BP is a novel and potential biomarker in clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most common solid renal tumor. Therefore, it is necessary to explore the related tumor markers. LGALS3BP (galectin 3 binding protein) is a multifunctional glycoprotein implicated in immunity and cancer. Some studies have shown that LGALS3BP promotes the occurrence and development of tumors. However, their exact role in renal tumorigenesis remains unclear. Our study used a webserver to explore the mRNA expression and clinical features of LGALS3BP in ccRCC. Survival analysis showed that patients with high LGALS3BP expression had significantly worse OS and DFS than those with low LGALS3BP expression. LGALS3BP expression is significantly related to B cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells. Furthermore, we determined that LGALS3BP is significantly associated with angiogenesis, stemness and proliferation in renal cancer. Three phenotypes may be associated with a poor prognosis. Genes related to proliferation, angiogenesis and stemness were derived from a Venn diagram of FGF2. FGF2 is negatively correlated with proliferation and positively correlated with angiogenesis. Finally, we screened for drugs that may have potential therapeutic value for ccRCC. The PCR results showed that the expression of LGALS3BP in the normal cell line was lower than that in the tumor cell lines. After LGALS3BP knockdown, the proliferation of 769-P and 786-O cells decreased. The present findings show that LGALS3BP is critical for ccRCC cell proliferation and may be a potential target and biomarker for ccRCC.

Genome-wide quantification of copy-number aberration impact on gene expression in ovarian high-grade serous carcinoma.

Copy-number alterations (CNAs) are a hallmark of cancer and can regulate cancer cell states via altered gene expression values. Herein, we have developed a copy-number impact (CNI) analysis method that quantifies the degree to which a gene expression value is impacted by CNAs and leveraged this analysis at the pathway level. Our results show that a high CNA is not necessarily reflected at the gene expression level, and our method is capable of detecting genes and pathways whose activity is strongly influenced by CNAs. Furthermore, the CNI analysis enables unbiased categorization of CNA categories, such as deletions and amplifications. We identified six CNI-driven pathways associated with poor treatment response in ovarian high-grade serous carcinoma (HGSC), which we found to be the most CNA-driven cancer across 14 cancer types. The key driver in most of these pathways was amplified wild-type KRAS, which we validated functionally using CRISPR modulation. Our results suggest that wild-type KRAS amplification is a driver of chemotherapy resistance in HGSC and may serve as a potential treatment target.

Stage II oesophageal carcinoma: peril in disguise associated with cellular reprogramming and oncogenesis regulated by pseudogenes.

INTRODUCTION: Pseudogenes have been implicated for their role in regulating cellular differentiation and organismal development. However, their role in promoting cancer-associated differentiation has not been well-studied. This study explores the tumour landscape of oesophageal carcinoma to identify pseudogenes that may regulate events of differentiation to promote oncogenic transformation. MATERIALS AND METHOD: De-regulated differentiation-associated pseudogenes were identified using DeSeq2 followed by 'InteractiVenn' analysis to identify their expression pattern. Gene expression dependent and independent enrichment analyses were performed with GSEA and ShinyGO, respectively, followed by quantification of cellular reprogramming, extent of differentiation and pleiotropy using three unique metrics. Stage-specific gene regulatory networks using Bayesian Network Splitting Average were generated, followed by network topology analysis. MEME, STREME and Tomtom were employed to identify transcription factors and miRNAs that play a regulatory role downstream of pseudogenes to initiate cellular reprogramming and further promote oncogenic transformation. The patient samples were stratified based on the expression pattern of pseudogenes, followed by GSEA, mutation analysis and survival analysis using GSEA, MAF and 'survminer', respectively. RESULTS: Pseudogenes display a unique stage-wise expression pattern that characterizes stage II (SII) ESCA with a high rate of cellular reprogramming, degree of differentiation and pleiotropy. Gene regulatory network and associated topology indicate high robustness, thus validating high pleiotropy observed for SII. Pseudogene-regulated expression of SOX2, FEV, PRRX1 and TFAP2A in SII may modulate cellular reprogramming and promote oncogenesis. Additionally, patient stratification-based mutational analysis in SII signifies APOBEC3A (A3A) as a potential hallmark of homeostatic mutational events of reprogrammed cells which in addition to de-regulated APOBEC3G leads to distinct events of hypermutations. Further enrichment analysis for both cohorts revealed the critical role of combinatorial expression of pseudogenes in cellular reprogramming. Finally, survival analysis reveals distinct genes that promote poor prognosis in SII ESCA and patient-stratified cohorts, thus providing valuable prognostic bio-markers along with markers of differentiation and oncogenesis for distinct landscapes of pseudogene expression. CONCLUSION: Pseudogenes associated with the events of differentiation potentially aid in the initiation of cellular reprogramming to facilitate oncogenic transformation, especially during SII ESCA. Despite a better overall survival of SII, patient stratification reveals combinatorial de-regulation of pseudogenes as a notable marker for a high degree of cellular differentiation with a unique mutational landscape.

Hsa_circ_0014606 Derived from Exosomes Promotes Gastric Carcinoma Tumorigenesis and Proliferation by Sponging miR-514b-3p to Upregulate HNRNPC.

Gastric cancer is a common malignant tumor, and due to its insidious onset and limited screening methods, most patients are diagnosed with advanced disease and have a poor prognosis. The circRNA in exosomes has an essential role in cancer diagnosis and treatment. However, the part of hsa_circ_0014606 within exosomes in gastric cancer progression is unclear. Firstly, we extracted exosomes from the serum of gastric cancer patients and healthy individuals by ultracentrifugation and analyzed the expression of hsa_circ_0014606 in both exosomes; then knocked down hsa_circ_0014606 in vivo and in vitro, respectively, to observe its effect on the physiological function of gastric cancer cells; finally, we used bioinformatics to screen hsa_circ_0014606 targeting miRNAs and mRNAs, and experiments were performed to verify the interrelationship between the three. The results showed that the level of hsa_circ_0014606 in the serum exosomes of gastric cancer patients was significantly higher than that of the healthy population. The knockdown of hsa_circ_0014606 slowed the proliferation of gastric cancer cells, significantly reduced migration and invasion ability, accelerated apoptosis, and reduced tumor size in mice. In addition, the expression of hsa_circ_0014606 was negatively correlated with the expression of miR-514b-3p and positively correlated with the expression of heterogeneous nuclear ribonucleoprotein C (HNRNPC). In conclusion, hsa_circ_0014606 exerted a pro-cancer effect indirectly through miR-514b-3p targeting gene HNRNPC, and this study provides a new potential target for treating gastric cancer.

EBV DNA methylation profiles and its application in distinguishing nasopharyngeal carcinoma and nasal NK/T-cell lymphoma.

BACKGROUND: As an oncovirus, EBV is associated with multiple cancers, including solid tumors and hematological malignancies. EBV methylation plays an important role in regulating tumor occurrence. However, the EBV methylation profiles in EBV-associated tumor tissues are poorly understood. RESULTS: In this study, EBV methylation capture sequencing was conducted in several different tumor tissue samples, including NPC, EBVaGC, lung LELC and parotid LELC. Besides, EBV capture sequencing and following qMSP were performed on nasopharyngeal brushing samples from NPC and nasal NKTCL patients. Our results showed that the EBV genome among different types of tumors displayed specific methylation patterns. Among the four types of tumors from epithelial origin (NPC, EBVaGC, lung LELC and parotid LELC), the most significant differences were found between EBVaGC and the others. For example, in EBVaGC, all CpG sites within 1,44,189-1,45,136 bp of the EBV genome sequence on gene RPMS1 were hyper-methylated compared to the others. Differently, significant differences of EBV CpG sites, particularly those located on gene BILF2, were observed between NPC and nasal NKTCL patients in nasopharyngeal brushing samples. Further, the methylated level of BILF2 was further detected using qMSP, and a diagnostic model distinguishing NPC and nasal NKTCL was established. The AUC of the model was 0.9801 (95% CI 0.9524-1.0000), with the sensitivity and specificity of 98.81% (95% CI 93.63-99.94%) and 76.92% (95% CI 49.74-91.82%), respectively. CONCLUSIONS: Our study reveals more clues for further understanding the pathogenesis of EBV, and provides a possibility for distinguishing EBV-related tumor by detecting specific EBV CpG sites.

Downregulation of NEBL promotes migration and invasion of clear cell renal cell carcinoma by inducing epithelial-mesenchymal transition.

As a member of the nebulin protein family and a structural protein of cytoskeleton, NEBL plays an important role in cardiac diseases. Recently, literature have reported the involvement of NEBL in the occurrence and development of various cancers except clear cell renal cell carcinoma (ccRCC). In this study, we found that mRNA and protein of NEBL are downregulated remarkably in ccRCC tissues based on both the TCGA database and clinical samples we collected. The areas under curve values of NEBL analyzed based on the TCGA database, qRT-PCR and IHC results were 0.9376, 0.9733 and 0.9807, respectively. The lower mRNA level of NEBL was associated with worse outcomes in ccRCC patients. When overexpressing NEBL in ccRCC cell lines, the proliferation, migration and invasion of ccRCC cells were suppressed significantly, suggesting a tumor suppressor role of NEBL. In addition, we identified that NEBL is closely related to epithelial-mesenchymal transition (EMT), thereby reducing the motility of ccRCC cells. Furthermore, the lower expression of NEBL was correlated with ccRCC patients with distant organ metastasis. In summary, we firstly described the aberrant expression of NEBL and revealed its tumor suppressor role in ccRCC. Our data support that NEBL could serve as a valuable diagnostic and prognostic biomarker in ccRCC, as well as a promising therapeutic target.

Amyloid aggregates induced by the p53-R280T mutation lead to loss of p53 function in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a malignant tumor that is highly prevalent in Southeast Asia, especially in South China. The pathogenesis of NPC is complex, and genetic alterations of tumor suppressors and proto-oncogenes play important roles in NPC carcinogenesis. p53 is unexpectedly highly expressed in NPC and possesses an uncommon mutation of R280T, which is different from a high frequency of hotspot mutations or low expression in other tumors. However, the mechanism of p53 loss of function and its correlation with R280T in NPC are still unclear. In this study, p53 amyloid aggregates were found to be widespread in NPC and can be mainly induced by the R280T mutation. Aggregated p53-R280T impeded its entry into the nucleus and was unable to initiate the transcription of downstream target genes, resulting in decreased NPC cell cycle arrest and apoptosis. In addition, NPC cells with p53-R280T amyloid aggregates also contributed aggressively to tumor growth in vivo. Transcriptome analysis suggested that p53 amyloid aggregation dysregulated major signaling pathways associated with the cell cycle, proliferation, apoptosis, and unfolded protein response (UPR). Further studies revealed that Hsp90, as a key molecular chaperone in p53 folding, was upregulated in NPC cells with p53-R280T aggregation, and the upregulated Hsp90 facilitated p53 aggregation in turn, forming positive feedback. Therefore, Hsp90 inhibitors could dissociate p53-R280T aggregation and restore the suppressor function of p53 in vitro and in vivo. In conclusion, our study demonstrated that p53-R280T may misfold to form aggregates with the help of Hsp90, resulting in the inability of sequestered p53 to initiate the transcription of downstream target genes. These results revealed a new mechanism for the loss of p53 function in NPC and provided novel mechanistic insight into NPC pathogenesis.