CTNNB1 (β-Catenin)-altered Neoplasia: A Review Focusing on Soft Tissue Neoplasms and Parenchymal Lesions of Uncertain Histogenesis

Comprehensive genomic analysis of adrenocortical carcinoma reveals genetic profiles associated with patient survival

BACKGROUND

Adrenocortical carcinoma (ACC) is one of the most lethal endocrine malignancies and there is a lack of clinically useful markers for prognosis and patient stratification. Therefore our aim was to identify clinical and genetic markers that predict outcome in patients with ACC.

METHODS

Clinical and genetic data from a total of 162 patients with ACC were analyzed by combining an independent cohort consisting of tumors from Yale School of Medicine, Karolinska Institutet, and Düsseldorf University (YKD) with two public databases [The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO)]. We used a novel bioinformatical pipeline combining differential expression and messenger RNA (mRNA)- and DNA-dependent survival. Data included reanalysis of previously conducted whole-exome sequencing (WES) for the YKD cohort, WES and RNA data for the TCGA cohort, and RNA data for the GEO cohort.

RESULTS

We identified 3903 significant differentially expressed genes when comparing ACC and adrenocortical adenoma, and the mRNA expression levels of 461/3903 genes significantly impacted survival. Subsequent analysis revealed 45 of these genes to be mutated in patients with significantly worse survival. The relationship was significant even after adjusting for stage and age. Protein-protein interaction showed previously unexplored interactions among many of the 45 proteins, including the cancer-related proteins DNA polymerase delta 1 (POLD1), aurora kinase A (AURKA), and kinesin family member 23 (KIF23). Furthermore 14 of the proteins had significant interactions with TP53 which is the most frequently mutated gene in the germline of patients with ACC.

CONCLUSIONS

Using a multiparameter approach, we identified 45 genes that significantly influenced survival. Notably, many of these genes have protein interactions not previously implicated in ACC. These findings may lay the foundation for improved prognostication and future targeted therapies.

CTNNB1 mutation-driven hybrid tumor: desmoid fibromatosis with an unusual associated epithelioid component arising in association with a neuromuscular choristoma

CTNNB1 mutations play important roles in the development of soft tissue tumors, such as desmoid fibromatosis (DF), sinonasal tract angiofibroma, sinonasal glomangiopericytoma, intranodal palisaded myofibroblastoma, neuromuscular choristoma (NMC), and the recently reported pseudoendocrine sarcoma. Here, we report a unique hybrid soft tissue tumor with classic DF, unusual epithelioid component, and NMC in a 23-year-old female. The classic DF and NMC and the unusual epithelioid component and NMC were locally intermixed and closely related to each other. Immunohistochemically, the DF, unusual epithelioid component, and NMC exhibited nuclear positivity for β-catenin to varying degrees. More critically, all of the above components harbored identical CTNNB1 p.Ser45Pro missense mutations. To the best of our knowledge, this is the only reported CTNNB1 mutation-driven hybrid tumor with DF, unusual epithelioid component, and NMC. The present case further confirmed that CTNNB1-mutational soft tissue tumors are highly heterogeneous, but the morphological spectrum is wide and consecutive.

Molecular map of cGAS-STING pathway-related genes in bladder cancer: the perspective toward immune microenvironment and prognosis

BACKGROUND

The cGAS-STING pathway emerges as a pivotal innate immune pathway with the potential to profoundly influence all facets of tumor initiation and progression. The prognostic significance and immunological role of cGAS-STING pathway-related genes (CRGs) in individuals diagnosed with bladder cancer (BLCA) have not yet been fully elucidated.

METHODS

Performed unsupervised cluster analysis to identify distinct clusters. Utilizing LASSO and multivariate Cox regression analysis to construct a prognostic risk model. The IMvigor210, GSE13507 and GSE78220 cohorts were utilized to explore the potential value of risk score in immune therapy response and survival prediction.

RESULTS

A risk model was developed utilizing four CRGs in order to forecast the overall survival (OS) of BLCA patients. The risk score to be a standalone risk factor, which was further corroborated by the external validation set obtained from the GEO database (GSE13507). We established an integrated nomogram that combined risk scoring and clinical information, exhibiting commendable clinical practicality in predicting the overall survival period of BLCA patients. It is noteworthy that risk score could differentiate tumor microenvironments among different risk groups and individuals who were more responsive to immunotherapy in IMvigor210 and GSE13507 cohorts. In vitro experiments, we noted an up-regulation of IRF3 and IKBKB upon the activation of the cGAS-STING pathway. Conversely, the activation of the cGAS-STING pathway resulted in a down-regulation of POLR3G and CTNNB1.

CONCLUSIONS

CRG risk model shows promise as a potential stratification approach for bladder cancer patients.

Solid pseudopapillary neoplasms of the pancreas in childhood and adolescence-an analysis of the German Registry for Rare Pediatric Tumors (STEP)

Solid pseudopapillary neoplasms (SPNs) are the most common entity among pediatric pancreatic tumors. Still, these are rare tumors with an annual incidence of 0.1-0.2/1,000,000, and little is known about their optimal treatment. This analysis aimed to increase knowledge about the occurrence and treatment strategies of SPN in childhood. Data regarding diagnostics, treatment, and outcome of children aged 0-18 years with SPN recorded in the German Registry for Rare Pediatric Tumors (STEP) were analyzed. Thirty-eight patients were identified with a median age of 14.5 years at diagnosis (range: 8-18) and a female preponderance (81.6%). The most frequent location of the tumor was the pancreatic tail. In histopathological and immunohistochemical examination, pseudopapillary, solid, and cystic lesions as well as expression of beta-catenin, progesterone receptors, and cyclin D1 were the most common findings. All patients underwent surgical resection. Most patients underwent open resection, predominantly tail resection for tumors in the tail region and pylorus-preserving pancreaticoduodenectomy for tumors in the head region. The main postoperative sequela was exogenous pancreatic insufficiency (23.7%), especially with SPN in the pancreatic head. No recurrence occurred during follow-up, although two patients underwent resection with microscopic residue.

CONCLUSION

SPN of the pancreas in childhood are low-grade malignancies with usually favorable treatment outcomes. However, therapy can lead to relevant long-term sequelae. To prevent recurrence, complete surgical resection is recommended, sparing as much healthy pancreatic tissue as possible. Interdisciplinary collaboration between specialists is essential to optimize treatment. Molecular genetic analysis of these tumors could improve understanding of their genesis.

WHAT IS KNOWN

• Solid pseudopapillary neoplasms (SPNs) of the pancreas are very rare tumors in childhood. • Little is known about tumorigenesis, and there are no specific guidelines for treatment and follow-up in pediatric patients.

WHAT IS NEW

• Characteristics, treatment, and outcome were comprehensively assessed in a large cohort of pediatric patients with SPN. • We propose recommendations for diagnosis, treatment, and follow-up of children with SPN, based on our analysis and considering published experience.

Utility of Retrospective Molecular Analysis in Diagnostically Challenging Mesenchymal Neoplasms

Introduction: Molecular analysis plays a growing role in the diagnosis of mesenchymal neoplasms. The aim of this study was to retrospectively apply broad, multiplex molecular assays (a solid tumor targeted next-generation sequencing [NGS]) assay and single nucleotide polymorphism [SNP] microarray) to selected tumors, exploring the current utility and limitations. Methods: We searched our database (2010-2020) for diagnostically challenging mesenchymal neoplasms. After histologic review of available slides, tissue blocks were selected for NGS, SNP microarray, or both. DNA and RNA were extracted using the AllPrep DNA/RNA FFPE Kit Protocol on the QIAcube instrument. The NGS platform used was the TruSight Tumor 170 (TST-170). For SNP array, copy number variant (CNV) analysis was performed using the OncoScanTM CNV Plus Assay. Results: DNA/RNA was successfully extracted from 50% of tumors (n = 10/20). Specimens not successfully extracted included 6 core biopsies, 3 incisional biopsies, and 1 resection; 4 were decalcified (3 hydrochloric acid, 1 ethylenediaminetetraacetic acid). Higher tumor proportion and number of tumor cells were parameters positively associated with sufficient DNA/RNA extraction whereas necrosis and decalcification were negatively associated with sufficient extraction. Molecular testing helped reach a definitive diagnosis in 50% of tumors (n = 5/10). Conclusions: Although the overall utility of this approach is limited, these molecular panels can be helpful in detecting a specific "driver" alteration.

CTNNB1 somatic mutations drive Wnt pathway activation in a case of incidental intranodal palisaded myofibroblastoma

Intranodal palisaded myofibroblastoma (IPM) is a rare stroma-derived spindle-cell neoplasm of the lymph node with myofibroblastic differentiation and CTNNB1 (β-catenin gene) somatic mutations. We present a case of IPM found incidentally in the staging of lung adenocarcinoma. We describe the major histopathological and phenotypic features, including a palisaded bland spindle cell proliferation with myofibroblastic differentiation and Wnt pathway activation by immunohistochemistry, including β-catenin expression. Production of osteoid-like collagen directly from tumor cells was observed. We confirmed p.Gly34Arg CTNNB1 mutation by direct sequencing. We also reviewed the literature for similar cases.

Glomangiopericytoma with CTNNB1 mutation

Glomangiopericytoma (GPC) is a rare tumour, accounting <0.5% of all nasal cavity tumours. It is classified as borderline malignant to indolent and is associated with perivascular myeloid cells. We report a case of GPC in a woman in her 80s who presented with nasal obstruction. The tumour originated from the nasal septum and was resected via endoscopic sinus surgery. Histopathological examination revealed dense spindle-shaped to oval-shaped mesenchymal cells forming tumour nodules with staghorn-like vessel formation. Immunohistochemical analysis revealed that the tumour cells were positive for α-smooth muscle actin, CD34, β-catenin and cyclin D1, whereas they were negative for STAT6. The percentage of Ki-67-positive cells was approximately 2%. Recent studies have demonstrated a high frequency of β-catenin (CTNNB1) mutations in GPC. We report a case of GPC where identifying CTNNB1 mutations (c.94G>C, p.D32H) was crucial for establishing a definitive diagnosis.

Inhibition of ferroptosis ameliorates hypertensive nephropathy through p53/Nrf2/p21 pathway by Taohongsiwu decoction: Based on network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Hypertensive nephropathy (HN) is a complication of hypertension. Taohongsiwu decoction (THSWD) is used clinically but its application in the prevention and treatment of HN remains unelucidated.

AIM OF STUDY

This study aims to explore the potential targets and molecular mechanisms of THSWD in the treatment of HN.

MATERIALS AND METHODS

A network pharmacology approach was used to predict the components and targets of THSWD for treating HN. Animal experiments were performed to verify the network pharmacology findings.

RESULTS

205 targets were identified and regarded as potential targets of THSWD in HN treatment. Subsequently, we screened 17 hub genes and identified TP53 as the most critical one. KEGG enrichment analysis showed that p53 signaling pathway might play a significant role. In vivo experiments indicated that high-salt diets can lead to high blood pressure, kidney injury, inflammation, and fibrosis. Furthermore, the altered levels of biomarkers (Iron, malondialdehyde, catalase, ferritin, transferrin, Superoxide dismutase and Glutathione Peroxidase 4) provided evidence of ferroptosis. We found that the ferroptosis inhibitor ferrostatin-1 (Fer-1) and THSWD could significantly alleviate HN by suppressing ferroptosis. THSWD and Fer-1 treatment downregulated the protein and mRNA expression of p53, p21, RB, and CTNNB1, which were upregulated by high salt. Meanwhile, THSWD and Fer-1 reversed the downregulation of Nrf2 caused by high-salt diet.

CONCLUSIONS

Our results suggested that THSWD attenuate HN induced by a high-salt diet through inhibiting ferroptosis via the p53/Nrf2/p21 pathway.

Comprehensive Molecular Profiling of Sinonasal Teratocarcinosarcoma Highlights Recurrent SMARCA4 Inactivation and CTNNB1 Mutations

Sinonasal teratocarcinosarcoma (TCS) is a rare tumor defined by intermixed neuroepithelial, mesenchymal, and epithelial elements. While its etiology was historically ambiguous, we recently reported frequent SMARCA4 loss by immunohistochemistry, suggesting that TCS might be related to SMARCA4-deficient sinonasal carcinomas. However, other molecular alterations including CTNNB1 mutation have been reported in TCS, and its full genetic underpinnings are unclear. Here, we performed the first comprehensive molecular analysis of sinonasal TCS to better understand its pathogenesis and classification. We collected 30 TCS including 22 cases from our initial study. Immunohistochemical loss of SMARCA4 was seen in 22 cases (73%), with total loss in 18 cases (60%). β-catenin showed nuclear localization in 14 cases (64%) of the subset tested. We selected 17 TCS for next-generation sequencing with enrichment for partial or intact SMARCA4 immunoexpression. We identified inactivating SMARCA4 mutations in 11 cases (65%) and activating CTNNB1 mutations in 6 cases (35%), including 5 cases with both. Of 5 cases that lacked SMARCA4 or CTNNB1 mutation, 2 harbored other SWI/SNF complex and Wnt pathway alterations, including 1 with SMARCB1 inactivation and 1 with concomitant APC and ARID1A mutations, and 3 had other findings, including DICER1 hotspot mutation. These findings confirm that SMARCA4 inactivation is the dominant genetic event in sinonasal TCS with frequent simultaneous CTNNB1 mutations. They further underscore a possible relationship between TCS and sinonasal carcinomas with neuroendocrine/neuroectodermal differentiation. However, while SMARCA4 and β-catenin immunohistochemistry may help confirm a challenging diagnosis, TCS should not be regarded as a molecularly defined entity.

miRNA-seq analysis in skeletal muscle of chicken and function exploration of miR-24-3p

The regulation of skeletal muscle growth and development in chicken is complex. MicroRNAs (miRNAs) have been found to play an important role in the process, and more research is needed to further understand the regulatory mechanism of miRNAs. In this study, leg muscles of Jinghai yellow chickens at 300 d with low body weight (slow-growing group) and high body weight (fast-growing group) were collected for miRNA sequencing (miRNA-seq) and Bioinformatics analysis revealed 12 differentially expressed miRNAs (DEMs) between the two groups. We predicted 150 target genes for the DEMs, and GO and KEGG pathway analysis showed the target genes of miR-24-3p and novel_miR_133 were most enriched in the terms related to growth and development. Moreover, networks of DEMs and target genes showed that miR-24-3p and novel_miR_133 were the 2 core miRNAs. Hence, miR-24-3p was selected for further functional exploration in chicken primary myoblasts (CPMs) with molecular biology technologies including qPCR, cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) and immunofluorescence. When proliferating CPMs were transfected with miR-24-3p mimic, the expression of cyclin dependent kinase inhibitor 1A (P21) was up-regulated and both CCK-8 and EdU assays showed that the proliferation of CPMs was inhibited. However, when the inhibitor was transfected into the proliferating CPMs, the opposite results were found. In differentiated CPMs, transfection with miR-24-3p mimic resulted in up regulation of MYOD, MYOG and MYHC after 48 h. Myotube areas also increased significantly compared to the mimic negative control (NC) group. When treated with inhibitor, differentiation CPMs produced the opposite effects. Overall, we revealed 2 miRNAs (novel_miR_133 and miR-24-3p) significantly related with growth and development and further proved that miR-24-3p could suppress the proliferation and promote differentiation of CPMs. The results would facilitate understanding the effects of miRNAs on the growth and development of chickens at the post-transcriptional level and could also have an important guiding role in yellow-feathered chicken breeding.

Prospects and applications of enucleation in solid pseudopapillary neoplasms of the pancreas

Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare, low-grade, malignant neoplasms that are mostly seen in young women in the second and third decades of life and are quite uncommon in children. Standard resection for benign and borderline neoplasms of the pancreas is associated with a substantial risk of postoperative morbidity and long-term functional impairment, whereas enucleation leads to less morbidity and preserves healthy parenchyma as well as exocrine and endocrine function. Enucleation of SPNs has been increasingly reported to be feasible and safe for preserving the normal physiological function of the pancreas, especially in teenagers and children. This review summarizes findings published in recent years on the enucleation of SPNs as well as potential future developments and directions. Enucleation has undoubtedly come to stay as an alternative surgical procedure for SPNs. However, many questions remain unresolved, and future directions toward the best surgical indication, the prevention and intervention of complications, especially pancreatic fistula, intraoperative resection margin safety assessment, and long-term oncology prognosis remain to be evaluated and should be explored in future clinical trials.

Immunohistochemical Localization of Phosphorylated and Unphosphorylated Form of β-catenin With Regard to Shadow Cell and Squamous Differentiation in Cutaneous Pilomatricoma

Pilomatricoma usually contains a mutation in CTNNB1 that encodes β-catenin (BC). It also shows nuclear accumulation of BC protein, which plays an important role in tumorigenesis of pilomatricoma. In vitro studies have indicated that mutant BC protein is unphosphorylated and shows nuclear accumulation, but this theory has not been confirmed in various tumors with CTNNB1 mutation. We examined immunohistochemical localization of phosphorylated BC (pBC) and unphosphorylated BC (npBC) with regard to the modes of cell death or differentiation in 25 cases of pilomatricoma. As for the component showing shadow cell differentiation, BC was detected in cytoplasm/nucleus and along cell membrane in basaloid cells, whereas only in the latter in transitional cells in all cases. Meanwhile, npBC was localized along cell membrane of transitional cells, but not in basaloid cells, nor in nucleus of any components. The components with squamous differentiation also revealed the staining patterns similar to those seen in shadow cell differentiation in some cases. pBC was found in some cell fragments in the amorphous debris containing apoptotic bodies among shadow cell nests. These results suggested that npBC plays an important role in cell adhesion during differentiation and that pBC expression is associated with apoptosis of basaloid cells in pilomatricoma. BC accumulated in the nucleus was not immunoreactive for npBC possibly due to post-translational modification or conformational changes that resulted in loss of or masked antigenicity when BC is assumed to be unphosphorylated.

Epstein-Barr Virus-Associated Smooth Muscle Tumors of Larynx: A Clinicopathologic Study and Comprehensive Literature Review of 12 Cases

Laryngeal mesenchymal neoplasms are rare, with smooth muscle tumors comprising a small subset. Specifically, Epstein-Barr virus (EBV)-associated smooth muscle tumors are exceptionally rare, lacking a comprehensive evaluation of their clinical and histologic features. Two patients (a 59 year old male and 51 year old female) had received renal transplants 156 and 240 months, respectively prior to onset of laryngeal symptoms. Supraglottic polypoid masses were identified and removed conservatively. Histologically, the tumors were hypercellular, showing alternating light and dark areas, the latter composed of primitive appearing round cells, while a more characteristic spindled tumor cell population was noted in the remaining areas. Cytoplasmic vacuoles were noted adjacent to the nucleus. There was no tumor necrosis or pleomorphism, but increased mitotic figures (11-12/2 mm²) were seen, without atypical forms. The tumor cells were strongly immunoreactive with smooth muscle actin and smooth muscle myosin heavy chain and with Epstein-Barr virus encoded RNA (EBER) by in situ hybridization. These patients were reviewed in the context of a thorough English literature review, which demonstrates a wide age range at presentation without a sex predilection, but with most patients from specific ethnic groups (Chinese, Thai, Pilipino). Three-quarters of patients are part of multifocal disease and the majority are post-renal transplantation patients. Conservative management seems to yield the best overall outcome for these indolent tumors. In conclusion, EBV-associated smooth muscle tumors should be considered in any immunocompromised patient with a head and neck smooth muscle tumor, especially when EBER is documented by in situ hybridization. Conservative management may be employed, even when multifocal tumors are documented.

Loss of CTNNB1 exon 3 in sclerosing angiomatoid nodular transformation of the spleen

Sclerosing angiomatoid nodular transformation (SANT) is a rare vascular lesion of the spleen. Although several hypotheses have been suggested, the etiopathogenesis of SANT remains unknown. It is also unclear whether SANT is a reactive or a neoplastic lesion. Since CTNNB1 (β-catenin gene) exon 3 mutations were frequently detected in some rare fibrovascular lesions, we aimed to investigate the presence of oncogenic CTNNB1 mutations in SANT cases. For this purpose, 7 cases of SANT with typical histopathological features were retrieved. First, the presence of CTNNB1 exon 3 alterations was examined with a recently described immunohistochemistry-based method. Then, the findings were confirmed with polymerase chain reaction (PCR), reverse transcription PCR (RT-PCR), and Sanger sequencing. In all cases, immunochemistry of β-catenin gave a staining pattern that was suggestive of exon 3 alteration; however, no missense mutations were found in any case at the CTNNB1 exon 3 hotspot region. Subsequently, we screened for large interstitial deletions of CTNNB1 exon 3 which revealed short PCR products in three cases. Sequencing confirmed that these cases had large interstitial deletions, resulting in loss of the entire exon 3 of CTNNB1. In the remaining four cases, loss of exon 3 was documented at the cDNA level, although genomic deletion was not identified. These results demonstrate that loss of CTNNB1 exon 3 and stabilization of β-catenin with activation of Wnt signaling pathway might have a significant role in the pathogenesis of SANT. Through this study, we provided important evidence for the neoplastic nature and pathogenesis of this disorder.

Investigation of effect of vitamin D receptor, calcium-sensing receptor and β-catenin on cutaneous squamous cell carcinoma

Background

Cutaneous squamous cell carcinoma (cSCC) is a malignant and invasive tumor which is originated from epidermis with a high incidence among non-melanoma skin cancers. The aim of this study was to determine whether vitamin D receptor (VDR), calcium-sensing receptor (CaSR) and beta catenin (β-catenin) proteins have an effect on cSCC.

Materials and methods

VDR, CaSR and β-catenin proteins in tissue samples of cSCC and control group were analyzed by immunohistochemistry (IHC) and Western blotting (WB) method. IHC findings were statistically evaluated.

Results

IHC staining density of VDR and β-catenin were higher in cSCC tissue samples than control. The difference between IHC staining density of VDR and β-catenin in the patient and the control groups were statistically significant (p = 0.021, p = 0.021, respectively), but not for CaSR (p = 0.237). While the VDR and β-catenin staining rates obtained by the IHC method could be supported by WB results, the WB bands for CaSR could not be shown.

Conclusion

The findings suggest that VDR and β-catenin may have an effect on the disease. Further research is required to better understand the role of VDR and β-catenin together on cSCC.

Comparison of the clinicopathological features of pancreatic solid pseudopapillary neoplasms between males and females: gender does matter

BACKGROUND

Solid pseudopapillary neoplasms (SPN) of the pancreas are a rare and low-grade malignant entity with a female predominance. However, it also occurs in males, but the rarity and lack of concern makes its clinicopathological features unclarified.

METHODS

The morphological, immunohistochemical, prognostic features and CTNNB1 exon 3 mutation status of SPN were compared semi-quantitively between 9 male and 21 female patients.

RESULTS

SPN in males grew in a distinctive solid pattern, with abundant fibrotic stroma and clear cells. Collagen tended to be the main component of tumor stroma in males, while hyaluronan composed a considerable proportion in females. A much stronger expression of androgen receptor (AR) was found in males, and CD56 and/or synaptophysin (Syn) was expressed frequently in both genders. All patients survived. One male patient had post-operational liver nodules and accepted interventional therapy without biopsy. Mutations of CTNNB1 exon 3 were observed in all cases, distributed at codon 32, 33 and 37 in both genders, as well as 34, 41 and 62 in females.

CONCLUSION

SPN in males presented with significantly different morphological features from that in females, which might be helpful in differential diagnosis, especially when with extensive positivity for CD56 and/or Syn. The stronger expression of AR in males might be a clue to explore the underlying mechanism of the gender difference.

Acinar cell carcinoma of the pancreas with thyroid-like follicular features: first description of a new diagnostic challenging subtype

Acinar cell carcinomas (ACCs) of the pancreas are a heterogeneous group of neoplasms showing a wide spectrum of morphological features including acinar, solid, glandular, and trabecular architecture. In addition, uncommon cytological aspects have recently been described and include oncocytic, spindle, clear, and pleomorphic cell types. This wide histological spectrum represents a challenge in the diagnostic task for pathologists. Molecular mechanisms involved in the onset and progression of ACCs are not completely known, but, in general, they differ from those observed in ductal adenocarcinomas or neuroendocrine neoplasms of the pancreas and frequently include alterations in the APC/β-catenin pathway. In the present paper, we describe a new variant of ACC showing thyroid-like follicular features and CTNNB1 mutation. This phenotype needs to be included in the spectrum of morphological presentation of ACC.

MALAT1-Driven Inhibition of Wnt Signal Impedes Proliferation and Inflammation in Fibroblast-Like Synoviocytes Through CTNNB1 Promoter Methylation in Rheumatoid Arthritis

Fibroblast-like synoviocytes (FLSs) participate in the pathogenesis of rheumatoid arthritis (RA). Emerging evidence has highlighted the role of long non-coding RNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) and its potential involvement in RA. In this study, we test the hypothesis that the MALAT1 might inhibit proliferation and inflammatory response of FLSs in RA. The expression of MALAT1 was examined in synovial tissues from patients with RA. The effect of MALAT1 on cultured FLSs was analyzed by introducing overexpressed MALAT1 or short hairpin RNA (shRNA) against MALAT1. To validate whether methylation of CTNNB1 promoter was affected by MALAT1 alternation, we assessed the recruitment of DNA methyltransferases to CTNNB1 promoter. In cultured FLSs with shRNA-mediated CTNNB1 knockdown or activated Wnt signaling, we found the interaction between CTNNB1 and Wnt signaling. MALAT1 expression was reduced in synovial tissues of RA. MALAT1 could bind to CTNNB1 promoter region and recruit methyltransferase to promote CTNNB1 promoter methylation, thereby inhibiting CTNNB1. Notably, MALAT1 could suppress the transcription and expression of CTNNB1, thereby modulating the Wnt signaling pathway. Silenced MALAT1 stimulated the nucleation of β-catenin and the secretion of inflammatory cytokines including interleukin-6, interleukin-10, and tumor necrosis factor-α. Additionally, shRNA-mediated MALAT1 silencing elevated proliferation and suppressed apoptosis of FLSs accompanied. These findings provide evidence for the inhibitory effect of MALAT1 on proliferation and inflammation of FLSs by promoting CTNNB1 promoter methylation and inhibiting the Wnt signaling pathway. Therefore, this study provides a candidate therapeutic target for RA.

[Diagnostic and predictive molecular pathology of head and neck neoplasms]

As a result of some seminal observations as well as a consequence of increasing use of modern and innovative molecular diagnostic technologies, a variety of new genetic aberrations have been discovered in head and neck neoplasms of different anatomic locations and histogenetic origins. These advances resulted in the establishment of new molecularly defined disease entities. On the other hand, some of these new genetic biomarkers paved the way to potentially promising novel therapeutic opportunities. Diverse old (well known in other entities) and newly discovered translocations and gene fusions represent the leading subgroup of these genetic aberrations. They have been detected not only in malignant epithelial neoplasms (carcinomas) of the salivary glands, but also in carcinomas from other head and neck sites as well as diverse mesenchymal tumors. In addition to these gene fusions, several activating mutations (such as CTNNB1 in sinonasal glomangiopericytoma) as well as inactivating mutations or deletions (like SMARCB1 loss in sinonasal carcinomas) were detected as new molecular markers. In the present review we summarize the relevant molecular alterations in topographically and histopathologically distinct tumors of the head and neck region with emphasis on recently established molecular markers.

Pancreatic analogue solid pseudopapillary neoplasm arising in the paratesticular location. The first case report

We describe the first pancreatic analogue of solid pseudopapillary neoplasm arising in paratesticular location. It was a tumor arising in 32-year-old man adhering closely to the testis. The tumor had several morphologic components. The greatest was represented by signet ring cells which gradually changed into solid, non-signet ring cell areas, often being mixed together. It also formed distinct trabeculae and pseudopapillae frequently adhering to cystic areas of the tumor. Immunohistochemically, the tumor had an identical profile to its pancreatic counterpart. The tumor cells reacted diffusely with S100 protein, β-catenin, cyclin D1, Fli-1, vimentin, CD10, galectin-3, and neuron-specific enolase and focally with synaptophysin. CD56 and E-cadherin reacted only in those parts of the tumor, which formed pseudopapillae. Cytokeratin antibody AE1-AE3 was strongly positive in the areas of trabecular formation of the tumor. The mutational analysis of exon 3 of the CTNNB1 gene confirmed mutation in this exon.

Pancreatic desmoid-type fibromatosis with beta-catenin gene mutation-Report of a case and review of the literature

We experienced a rare case of pancreatic desmoid-type fibromatosis (DTF) in a 75-year-old Japanese woman. She was asymptomatic but routine examination including ultrasonography revealed a mass in the abdomen. For precise examination, she was referred to the regional hospital. Computed tomography showed that the mass was protruding anteriorly from the left-sided pancreas. Because of the enlargement of the mass lesion, distal pancreatectomy with splenectomy was performed after about 3 months. Macroscopically, the mass was encapsulated and approximately 8cm in diameter. Histological examination revealed that spindle or blunt stellate cells were proliferating in parallel or storiform fashion with myxoid and fibrous background. The tumor cells did not show prominent atypia and mitoses were rarely seen, suggesting that the tumor was low grade or borderline. Immunohistochemistry showed obvious nuclear staining of beta-catenin. Furthermore, analysis of beta-catenin gene revealed that the tumor had a typical missense mutation of threonine to alanine at colon 41 (T41A) in exon 3. These findings confirmed the pathological diagnosis of DTF of the pancreas. To the best of our knowledge, 18 cases of pancreatic DTF have been reported in the English literature and beta-catenin gene mutation had been examined in only one case among them. Thus, our case is the 19th pancreatic DTF and the second case with confirmed beta-catenin gene mutation.