MUC4 O-GlcNAcylation Regulates the Epithelial Phenotype in Conjunctival Epithelial Cells.

In the present study, our aim was to explore the role of MUC4 in IL-4-stimulated conjunctival epithelial cells and the underlying mechanisms. Human recombinant IL-4 was employed in human conjunctival epithelial cells (HConEpic) cells, and MUC4 shRNA (sh-MUC4) was constructed to explore the functional role of MUC4. The protein level of MUC4, O-GlcNAc transferase (OGT), O-GlcNAc hydrolase (OGA), zonula occludens 1 (ZO-1), gap junction protein beta 2 (GJB2), claudin-8 (CLDN8), and E-cadherin were detected by Western blot in HConEpic cells, the interaction between MUC4 and OGT/OGA was assessed by co-immunoprecipitation (IP) and Western blot in 293T cells. Our results showed that IL-4 significantly up-regulated MUC4 and OGT protein levels in HConEpic cells, while down-regulated OGA protein level. Also, IL-4 down-regulated ZO-1, GJB2, CLDN8, and E-cadherin protein levels in HConEpic cells, while which was markedly reversed by sh-MUC4. Additionally, OGT inhibitor significantly reduced MUC4 protein level, and elevated ZO-1, GJB2, CLDN8, and E-cadherin protein levels in HConEpic cells, while OGA inhibitor resulted in the opposite results. Furthermore, in addition to the interaction between OGT/OGA and MUC4, Co-IP and Western blot also revealed the alteration of MUC4 O-GlcNAcylation in 293T cells treated with OGT/OGA inhibitor. Above findings suggested that OGT/OGA inhibitor regulated MUC4 protein level by affecting MUC4 O-GlcNAcylation to regulate ZO-1, GJB2, CLDN8, and E-cadherin protein levels in HConEpic cells, which was achieved via inhibiting the interaction between OGT/OGA and MUC4. This study may provide a better understanding of the pathogenesis of allergic conjunctivitis (AC).

Primary sclerosing epitheloid fibrosarcoma of the kidney: First case reported in Mexico.

Here we reported a case of primary sclerosing epitheloid fibrosarcoma (SEF) of the kidney, an extremely rare and aggressive tumor. The patient presented a mass in the upper part of the right kidney with pulmonary metastasis at the time of diagnosis, a right radical nephrectomy was performed, it was a solid tumor of 15 cm × 9 cm affecting almost the entire kidney. Histological study revealed a neoplasm of uniform epithelioid cells with scant cytoplasm with dense and sclerotic stroma. immunohistochemistry positive for MUC-4, detection by fusion of EWSR1-CREB3L1 by FISH positive.

Primary lung low-grade fibromyxoid sarcoma: A rare case with A diagnostic dilemma.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare, low-grade malignant soft tissue tumor that is often mistaken for benign or more rarely malignant tumor types. Commonly, this tumor affects young adults and typically arises in the deep proximal extremities or trunk with frequent recurrences and can metastasize to the lungs many years late. Visceral LGFMS is extremely rare. Only a few cases of primary LGFMS of the lung have been reported. Here, we present the clinical, gross, microscopic, and immunohistochemical characteristics of Evans tumor occurring in the lung with a review of the literature and discuss the differential diagnosis in this exceptional localization.

Primary sclerosing epithelioid fibrosarcoma of the kidney: A rare case report.

Sclerosing epithelioid fibrosarcoma (SEF) represents a rare variant of fibrosarcoma primarily arising in the deep soft tissue of the extremities and trunk. The author reported a rare case of SEF emerged primarily in the kidney. Clinically, the patient complained of hematuria. The diagnosis was confirmed by histological examination and immunohistochemical staining of MUC4. Subsequent fluorescence in situ hybridization (FISH) analysis detected the presence of EWSR1 gene rearrangement, further confirming the histological diagnosis. The patient has been alive with 12 months follow-ups after nephrectomy. The disease should be considered in the differential diagnosis for primary renal tumors.

Novel KMT2B gene mutation in MUC4 positive low-grade fibromyxoid sarcoma.

BACKGROUND: Low-grade Fibromyxoid Sarcoma(LGFM)is a rare fibrosarcoma, which mainly occurs in young people and is mostly seen in the trunk and limbs. The tumor is usually FUS-CREB3L2 fusion caused by t(7;16)(q32-34;p11)chromosome translocation, and rarely FUS-CREB3L1 and EWSR1-CREB3L1 fusion. MUC4 diffuse strong positive can be used as a specific index of LGFM. LGFM is similar to Sclerosing Epithelioid Fibrosarcoma(SEF) and may have the same origin. CASE PRESENTATION: We report a case of LGFM in the chest wall. A female who is 59 years old. In 2016, CT showed dense nodule shadow and focal thickening of the left pleura, the patient underwent surgery, Pathological report that low to moderate malignant fibrosarcoma(fibromyxoid type). The CT re-examination in 2021 showed that the tumors on the left chest wall were significantly larger than before. Pathological examination showed the disease is composed of alternating collagen like and mucinous areas. Under high-power microscope, the tumor cells are consistent in shape, spindle or short spindle, and the tumor cells are arranged in bundles. In local areas, the density of tumor cells is significantly increased, mixed with collagen fibers, and small focal SEF appear. The result of immunohistochemistry showed that SMA, Desmin, CD34, STAT6, S100, SOX10, HMB45 and Melan A were negative, EMA was weakly positive, MUC4 was diffuse and strongly positive, and Ki67 index was low (3%). CONCLUSION: Sequencing results showed that MET, EGFR, KMT2B and RET gene were mutated in LGFM, and KMT2B gene had cancer promoting effect, but there was no literature report in LGFM, which may be of certain significance for the diagnosis and treatment of LGFM.

Isolation of Membrane Bound Mucins from Human Bronchial Epithelial Cells.

Membrane-bound mucins constitute a large portion of the periciliary layer of lung epithelial surfaces, and thus play an important role in many aspects of innate defense. The biophysical and biochemical properties of the membrane-bound mucins have important implications for mucociliary clearance, viral penetration, and potential therapeutics delivered to the airway surface. Hence, isolating them and determining these properties is important in understanding airways disease and ultimately in developing treatments. Here, we describe a method using isopycnic centrifugation to enrich and isolate shed membrane-bound mucins from the washings of human bronchial epithelial cell cultures.

Sclerosing Epithelioid Fibrosarcoma.

Sclerosing epithelioid fibrosarcoma (SEF) is a distinctive sarcoma that may arise in nearly any soft tissue site or bone. While there has been past controversy as to whether it is related to low-grade fibromyxoid sarcoma (LGFMS), it has been shown to behave far more aggressively than LGFMS. SEF has a propensity to metastasize to the lungs and bone and arise within the abdominal cavity. Histologically, it is characterized by uniform nuclei embedded in a densely collagenous stroma simulating osteoid. By immunohistochemistry, it is often strongly positive for MUC4. The majority (75%) have EWSR1 gene rearrangement, most commonly with CREB3L1 as a fusion partner, although a variety of FUS/EWSR1 and CREB3L1/CREB3L2/CREB3L3 fusions have been described in addition to others. SEF is currently recalcitrant to nearly all chemotherapy and radiation therapy.

Survey on resistance occurrence for F4+ and F18+ enterotoxigenic Escherichia coli (ETEC) among pigs reared in Central Italy regions.

Porcine Post Weaning Diarrhoea (PWD) is one of the most important swine disease worldwide, caused by Enterotoxigenic Escherichia coli (ETEC) strains able to provoke management, welfare and sanitary issues. ETEC is determined by proteinaceous surface appendages. Numerous studies conducted by now in pigs have demonstrated, at the enterocytes level, that, the genes mucin 4 (MUC4) and fucosyltransferase (FUT1), coding for ETEC F4 and F18 receptors respectively, can be carriers of single nucleotide polymorphisms (SNPs) associated with natural resistance/susceptibility to PWD. The latter aspect was investigated in this study, evaluating the SNPs of the MUC4 and FUT1 genes in slaughtered pigs reared for the most in Central Italy. Genomic DNA was extracted from 362 swine diaphragmatic samples and then was subjected to the detection of known polymorphisms on MUC4 and FUT1candidate target genes by PCR-RFLP. Some of the identified SNPs were confirmed by sequencing analysis. Animals carrying the SNPs associated with resistance were 11% and 86% for the FUT1 and MUC4 genes respectively. Therefore, it can be assumed that the investigated animals may be an important resource and reservoir of favorable genetic traits for the breeding of pigs resistant to enterotoxigenic E.coli F4 variant.

The Expression of Mucin-4 (MUC4) in Sarcomas Apart From Sclerosing Epithelioid Fibrosarcoma and Low-Grade Fibromyxoid Sarcoma.

Background Low-grade fibromyxoid sarcoma (LGFMS) and sclerosing epithelioid fibrosarcoma (SEF) are two rare but aggressive soft tissue sarcomas that can be difficult to distinguish due to histopathological similarities. The present study examines the diagnostic capacities of mucin-4 (MUC4), a transmembrane mucin, in identifying different types of sarcomas and broadens its evaluation to include a wide range of sarcomas. Methods Immunohistochemical (IHC) examination of tissue samples from various sarcomas was performed using a mouse anti-MUC4 monoclonal antibody. IHC was conducted on 4-mm thick formalin-fixed paraffin-embedded tissue sections after pressure cooker antigen retrieval with a mouse anti-MUC4 monoclonal antibody. Results MUC4 was shown to be highly expressed in SEF (n=13) and LGFMS (n=10), while focal positivity in synovial sarcoma (n=1). Other sarcomas, such as malignant peripheral nerve sheath tumors, fibrosarcoma, leiomyosarcoma, liposarcoma, and myxofibrosarcoma, exhibited no expression (n=0). These findings are consistent with previous research and support MUC4 specificity as a SEF and LGFMS marker. This study provides information on the diagnostic efficacy of MUC4, particularly in the context of certain subtypes. It not only helps our understanding of these unique instances, but it also provides context for histopathological and IHC findings in soft tissue sarcoma. Furthermore, this study investigates the influence of age and gender on MUC4 expression in a range of sarcomas, which was typically understudied in the literature and found no relation with expression of MUC4. Conclusion In conclusion, this study adds to our understanding of soft tissue sarcomas by emphasizing the crucial role of MUC4 in certain sarcoma subtypes while acknowledging the complex variety of the sarcoma landscape. Further research is needed to understand the molecular mechanism that governs marker expression patterns, as well as the therapeutic implications.

Oncogenic KRAS, Mucin 4, and Activin A-Mediated Fibroblast Activation Cooperate for PanIN Initiation.

Over 90% of patients with pancreatic ductal adenocarcinoma (PDAC) have oncogenic KRAS mutations. Nevertheless, mutated KRAS alone is insufficient to initiate pancreatic intraepithelial neoplasia (PanIN), the precursor of PDAC. The identities of the other factors/events required to drive PanIN formation remain elusive. Here, optic-clear 3D histology is used to analyze entire pancreases of 2-week-old Pdx1-Cre; LSL-KrasG12D/+ (KC) mice to detect the earliest emergence of PanIN and observed that the occurrence is independent of physical location. Instead, it is found that the earliest PanINs overexpress Muc4 and associate with αSMA+ fibroblasts in both transgenic mice and human specimens. Mechanistically, KrasG12D/+ pancreatic cells upregulate Muc4 through genetic alterations to increase proliferation and fibroblast recruitments via Activin A secretion and consequently enhance cell transformation for PanIN formation. Inhibition of Activin A signaling using Follistatin (FST) diminishes early PanIN-associated fibroblast recruitment, effectively curtailing PanIN initiation and growth in KC mice. These findings emphasize the vital role of interactions between oncogenic KrasG12D/+ -driven genetic alterations and induced microenvironmental changes in PanIN initiation, suggesting potential avenues for early PDAC diagnostic and management approaches.

Relationship Between MUC4 Variants and Metastatic Recurrence in Colorectal Cancer.

Background: Recurrent metastasis after radical resection in patients of colorectal cancer (CRC) is a great challenge for the world, in which genomic alterations play a major role in tumorigenesis. MUC4 plays a significant role in recurrence and metastasis in tumor. This study is aimed at exploring the association between MUC4 variants and metastatic recurrence of CRC. Methods: Forty-seven patients relapsing with metastasis and 37 patients remaining disease-free postoperatively were enrolled. Next-generation sequencing (NGS) detected mutations. Mutation and mRNA expression data were downloaded from TCGA and cBioPortal databases. We analyzed the relationship between MUC4 variants and clinical parameters, as well as possible molecular mechanisms. Results: MUC4 variants rs56359992 and rs781124621 were associated with survival in patients with CRC. Rs56359992 was more common in patients with metastatic recurrence. MAPK pathway, PI3K-Akt pathway, JAK-STAT pathway, cell cycle, WNT pathway and mTOR pathway were found to correlate with MUC4 mutation by GO/KEGG analysis, as well as resting and activated mast cell related to MUC4 mutation by CIBERSORT analysis. Conclusion: Genetic variants of MUC4 with CRC may constitute a molecular signature of metastatic recurrence. MUC4 may become a new target for the treatment of CRC recurrence.

Utility of MUC4 in the diagnosis of secretory carcinoma of salivary glands.

Salivary gland tumors are diverse in morphology and both benign and malignant tumors may pose diagnostic challenges especially in small biopsies. Secretory carcinoma (SC) is histologically characterized by microcysts, follicles, solid growth pattern and occasional papillary structures, and absence of zymogen granules. SC is molecularly defined by the presence of novel gene fusion ETV6::NTRK3. Among the positive stains (S100 and mammaglobin), MUC4 is now another promising marker for the diagnosis of SC, that would enable the pathologists to exclude other morphologically close simulators. Aim of this study was to report clinicopathological features and assess utility of MUC4 in the diagnosis of SC. MUC4 was performed on 22 cases of SC. Glass slides were reviewed to record morphological patterns and staining of S100, mammaglobin, DOG1 and MUC4. Age ranged from 9 to 63 years with mean age of 34.41 ± 16.28 years. The male: female ratio was 72.7 %:27.3 %. The majority occurred in major salivary glands. A combination of patterns was seen; microfollicles were the most prevalent (90 %) followed by papillary-cystic and macrofollicles. MUC4 was positive in 19/21 (90 %) cases with almost equal number of 2+ and 3+ staining. MUC4 was negative in all cases of acinic cell carcinoma, polymorphous adenocarcinoma, adenoid cystic carcinoma, salivary duct carcinoma, myopepithelioma and myoeithelial carcinoma, cystadenoma and cribriform adenocarcinoma and all except 3 cases of mucoepidermoid carcinoma tested. Overall sensitivity of MUC4 was 95.4 %, specificity 90 %, p-value being <0.01, positive predictive value 87.5 % and negative predictive value 96.4 %. A characteristic cytoplasmic granular pattern was observed in 76.1 % tumors. S100 and mammaglobin were positive in all the performed cases. DOG1 was positive in 6/11 (28.5 %) tumors. In conclusion, MUC4 is a useful addition to a diagnostic immunohistochemical panel for SC, and to distinguish it from close potential mimickers such as acinic cell carcinoma, especially in practice settings where molecular testing is unavailable.

Low-grade Fibromyxoid Sarcoma With Massive Degeneration: A Case of Unusual Gross and Histological Features.

BACKGROUND: Low-grade fibromyxoid sarcoma (LGFMS) is a rare type of sarcoma which is observed in the soft tissue of proximal extremities, typically in young and middle-aged adults. It consists of a solid proliferation of bland spindle cells within collagenous and myxoid stroma. CASE REPORT: Herein, we report a case of LGFMS with massive degeneration and hyalinization. A 30-year-old man presented with a well-circumscribed mass measuring 15 cm in diameter in his left biceps femoris muscle. Marginal tumor resection was performed under the clinical diagnosis of an ancient schwannoma or chronic expanding hematoma (CEH). The resected tissue revealed a well-demarcated tumor mass with massive degeneration and hyalinization with focal calcification. Proliferation of spindle tumor cells with abundant collagenous stroma, which resembled the fibrous capsule of CEH, was observed exclusively in a small area of the periphery of the tumor. No nuclear palisading, myxoid stroma, or collagen rosettes were identified. Immunohistochemical analysis demonstrated that the spindle tumor cells expressed mucin 4 and epithelial membrane antigen. Reverse transcriptase-polymerase chain reaction analysis detected mRNA expression of fused in sarcoma::CAMP-responsive element binding protein 3-like protein 2 (FUS::CREB3L2) fusion gene. Thus, a final diagnosis of LGFMS with massive degeneration and FUS::CREB3L2 fusion was made. CONCLUSION: The recognition of massive degeneration and hyalinization as unusual features of LGFMS might be helpful to differentiate it from CEH and other benign spindle-cell tumors.

Whole-exome sequencing of calcitonin-producing pancreatic neuroendocrine neoplasms indicates a unique molecular signature.

Introduction: Calcitonin-producing pancreatic neuroendocrine neoplasms (CT-pNENs) are an extremely rare clinical entity, with approximately 60 cases reported worldwide. While CT-pNENs can mimic the clinical and diagnostic features of medullary thyroid carcinoma, their molecular profile is poorly understood. Methods: Whole-exome sequencing (WES) was performed on tumor and corresponding serum samples of five patients with increased calcitonin serum levels and histologically validated calcitonin-positive CT-pNENs. cBioPortal analysis and DAVID gene enrichment analysis were performed to identify dysregulated candidate genes compared to control databases. Immunohistochemistry was used to detect the protein expression of MUC4 and MUC16 in CT-pNEN specimens. Results: Mutated genes known in the literature in pNENs like MEN1 (35% of cases), ATRX (18-20% of cases) and PIK3CA (1.4% of cases) were identified in cases of CT-pNENs. New somatic SNVs in ATP4A, HES4, and CAV3 have not been described in CT- pNENs, yet. Pathogenic germline mutations in FGFR4 and DPYD were found in three of five cases. Mutations of CALCA (calcitonin) and the corresponding receptor CALCAR were found in all five tumor samples, but none of them resulted in protein sequelae or clinical relevance. All five tumor cases showed single nucleotide variations (SNVs) in MUC4, and four cases showed SNVs in MUC16, both of which were membrane-bound mucins. Immunohistochemistry showed protein expression of MUC4 in two cases and MUC16 in one case, and the liver metastasis of a third case was double positive for MUC4 and MUC16. The homologous recombination deficiency (HRD) score of all tumors was low. Discussion: CT-pNENs have a unique molecular signature compared to other pNEN subtypes, specifically involving the FGFR4, DPYD, MUC4, MUC16 and the KRT family genes. However, a major limitation of our study was the relative small number of only five cases. Therefore, our WES data should be interpreted with caution and the mutation landscape in CT-pNENs needs to be verified by a larger number of patients. Further research is needed to explain differences in pathogenesis compared with other pNENs. In particular, multi-omics data such as RNASeq, methylation and whole genome sequencing could be informative.

[Role and clinical significance of MUC4 gene mutations in thrombotic events in patients with classic paroxysmal nocturnal hemoglobinuria].

Objective: This study aimed to investigate the role and clinical significance of MUC4 gene mutations in thrombotic events in patients with classic paroxysmal nocturnal hemoglobinuria (PNH) patients. Methods: A retrospective analysis was conducted on the clinical data and gene sequencing results of 45 patients with classic PNH admitted to the Department of Hematology, Tianjin Medical University General Hospital, from June 2018 to February 2022. MUC4 gene mutations in patients with classic PNH were summarized, and the risk factors for thrombotic events in these patients were analyzed. Additionally, the effects of MUC4 gene mutations on the cumulative incidence and survival of thrombotic events in patients with classic PNH were determined. Results: The detection rate of MUC4 gene mutations in patients with classic PNH who experienced thrombotic events (thrombotic group) was 68.8% (11/16), which was significantly higher than that in the non-thrombotic group [10.3% (3/29) ] (P<0.001). All mutations occurred in exon 2. MUC4 mutation (OR=20.815, P=0.010) was identified as an independent risk factor for thrombotic events in patients with classic PNH. The cumulative incidence of thrombotic events was 78.6% (11/14) in the MUC4 gene mutation group (mutation group) and 16.1% (5/31) in the non-mutation group, showing a statistically significant difference between the two groups (P<0.001). Survival analysis showed a lower overall survival (OS) rate in the thrombotic group compared with that in the non-thrombotic group [ (34.4±25.2) % vs. (62.7±19.3) % ] (P=0.045). The OS rate of patients was (41.7±29.9) % in the mutation group and (59.1±18.3) % in the non-mutation group (P=0.487) . Conclusion: MUC4 gene mutations are associated with an increased incidence of thrombotic events in classic PNH patients, highlighting their role as independent risk factors for thrombosis in this population. These mutations can be considered a novel predictive factor that aids in evaluating the risk of thrombosis in patients with classic PNH.

An mRNA Profiling Study of Vaginal Swabs from Pre- and Postmenopausal Women.

Body fluid identification by means of mRNA profiling provides valuable supplementary information in forensic investigations. In particular, the detection of vaginal mucosa mRNA markers is highly relevant in sexual assault cases. Although the vagina undergoes characteristic age-related physiological changes over a lifetime, few studies have evaluated the efficacy of vaginal mRNA markers in women of different ages. In this multicentric study, a 19-plex mRNA profiling assay including vaginal-specific markers (CYP2B7P1, MUC4, MYOZ1) was tested in a collection of 6-20-month-old vaginal swabs obtained from pre- (n = 84) and postmenopausal (n = 55) female volunteer donors. Overall, participating laboratories were able to correctly identify ~85% of samples as vaginal mucosa by mRNA profiling. The assay's success rate did not differ between the two age groups and was not affected by the time interval between swab collection and RNA analysis. MYOZ1 resulted a less sensitive vaginal marker compared to MUC4 and CYP2B7P1. A significant relative increase in the contribution to the total amplification signal was observed for MUC4, compared to CYP2B7P1 and MYOZ1, in postmenopausal women. Observation of other body fluids and tissues different from vaginal mucosa was also evaluated in connection to information on previous sexual activity and menstrual cycle phase at the time of sampling.

LncRNA BBOX1-AS1 Contributes to the Development of Nasopharyngeal Carcinoma via miR-204-5p/MUC4 Axis.

OBJECTIVE: Dysregulation of long non-coding RNAs (lncRNAs) is common in nasopharyngeal carcinoma (NPC) progression, and it is important to have an in-depth understanding of their functions in NPC. This study is the first to explore the role of the lncRNA BBOX1-AS1 in NPC development. METHODS: The expression of lncRNA BBOX1-AS1, MUC4, or miR-204-5p was measured in NPC cell lines or tissues via RT-qPCR and western blotting. Wound healing assays and CCK-8 were used to identify cell migration and cell viability, respectively. The protein expression of Bax and Bcl-2 was measured by western blotting. The tumorigenic effect of NPC cells in vivo was verified using xenograft tumors in nude mice. Luciferase reporter and RIP assays were conducted to clarify the association between miR-204-5p and lncRNA BBOX1-AS1 or MUC4. RESULTS: lncRNA BBOX1-AS1 upregulation was observed in NPC cells and tissues. Silencing lncRNA BBOX1-AS1 suppressed the migration and viability of C666-1 and TW03 cells while promoting cell apoptosis. Knockdown of the lncRNA BBOX1-AS1 repressed tumor growth in vivo. Moreover, the tumor suppression effect of silenced lncRNA BBOX1-AS1 might be reversed with the help of the miR-204-5p inhibitor. lncRNA BBOX1-AS1 targets miR-204-5p and regulates MUC4 expression in NPC. MUC4 is a miR-204-5p target and exerts a function similar to that of lncRNA BBOX1-AS1. CONCLUSION: These observations highlight that lncRNA BBOX1-AS1 is an essential NPC progression promoter and suggest that the lncRNA BBOX1-AS1/miR-204-5p/MUC4 axis is a potential therapeutic target in NPC.

Low-grade fibromyxoid sarcoma of the breast: genetic characterization and immunohistochemical comparison to morphologic mimics.

Spindle cell lesions of the breast elicit a specific, relatively limited differential diagnosis, and accurate classification often requires careful morphologic evaluation and immunohistochemical workup. Low-grade fibromyxoid sarcoma (LGFMS) is a rare malignant fibroblastic tumor with deceptively bland spindle cell morphology. Involvement of the breast is exceedingly rare. We examined the clinicopathologic and molecular characteristics of three cases of breast/axillary LGFMS. In addition, we interrogated the immunohistochemical expression of MUC4, a commonly used marker of LGFMS, in other breast spindle cell lesions. LGFMS presented in women at 23, 33, and 59 years of age. Tumor size ranged from 0.9 to 4.7 cm. Microscopically, they were circumscribed nodular masses composed of bland spindle cells with fibromyxoid stroma. Immunohistochemically, tumors were diffusely positive for MUC4 and negative for keratin, CD34, S100 protein, and nuclear beta-catenin. Fluorescence in-situ hybridization demonstrated FUS (n = 2) or EWSR1 (n = 1) rearrangements. Next-generation sequencing identified FUS::CREB3L2 and EWSR1::CREB3L1 fusions. MUC4 immunohistochemistry performed on 162 additional breast lesions demonstrated only weak and limited expression in a subset of cases of fibromatosis (10/20, ≤30% staining), scar (5/9, ≤10%), metaplastic carcinoma (4/23, ≤5%), and phyllodes tumor (3/74, ≤10%). MUC4 was entirely negative in cases of pseudoangiomatous stromal hyperplasia (n = 9), myofibroblastoma (n = 6), periductal stromal tumor (n = 3), and cellular/juvenile fibroadenoma (n = 21). LGFMS can rarely occur in the breast and should be considered in the differential diagnosis of breast spindle cell lesions. Strong and diffuse MUC4 expression is highly specific in this histologic context. Detection of an FUS or EWSR1 rearrangement can confirm the diagnosis.

MUC4 Expression in Oral Dysplastic Epithelium and Oral Squamous Cell Carcinoma: An Immunohistochemical Study.

Objective: MUCIN4 (MUC4) glycosylation is linked to the oncogenesis and progression of a neoplastic process. It can suggest information pertaining to tumor progression, management and its natural properties. Thus, MUC4 can play a pivotal role in prognostic diagnosis. This study aimed to analyze the MUC4 expression in oral cell squamous carcinoma and oral dysplastic epithelium. Materials and Methods: The research included 45 samples of oral epithelial dysplasia (OED) and 45 cases of oral squamous cell carcinoma (OSCC). In order to carry out the investigation, tissue blocks of previously diagnosed cases of OED and OSCC were retrieved from the relevant archives. Forty-five OED cases were categorized into three group's mild, moderate and severe dysplasia, with 15 cases in each respective category. Forty-five OSCC cases were categorized into three groups: well differentiated, moderately differentiated, and poorly differentiated OSCC with 15 cases in each respective category. Ten tissue biopsies of normal oral mucosa were obtained from subjects in the control group. The chi-square test and one-way ANOVA were used for statistical analysis. Result: There was an absence of MUC4 expression in normal mucosa, whereas the OED and OSCC groups had a significant amount of observable variance. Within the OED category of cases, a consistent progression from mild to severe dysplasia was seen in terms of the staining pattern. Cases with severe dysplasia displayed a staining pattern that covered the complete thickness of the tissue in the epithelium. Expression of MUC4 was shown to be lower in moderate differentiated squamous cell carcinoma (MDSCC), and poorly differentiated squamous cell carcinoma (PDSCC) as compared to well differentiated squamous cell carcinoma (WDSCC). It showed decreasing pattern across all grades of OSCC. In WDSCC, an intense highest staining response was noticed, particularly among the cells that are highly differentiated and take the form of a honeycomb pattern. Conclusion: Analysis of the expression profile of MUC4 and the aberrant expression of this gene in OSCC suggests that it may serve as a useful diagnostic marker. Therefore, it is possible to draw the conclusion that MUC4 plays a very significant part in the pathogenesis of OSCC and also acts as a marker that may be taken into consideration for the accurate diagnosis of OED and OSCC.

Superparamagnetic iron oxide nanoparticles target BxPC-3 cells and silence MUC4 for the treatment of pancreatic cancer.

PURPOSE: Superparamagnetic iron oxide nanoparticles (SPION) are excellent magnetic resonance imaging (MRI) contrast agents. Mucin 4 (MUC4) acts as pancreatic cancer (PC) tumor antigen and influences PC progression. Small interfering RNAs (siRNAs) are used as a gene-silencing tool to treat a variety of diseases. METHODS: We designed a therapeutic probe based on polyetherimide-superparamagnetic iron oxide nanoparticles (PEI-SPION) combined with siRNA nanoprobes (PEI-SPION-siRNA) to assess the contrast in MRI. The biocompatibility of the nanocomposite, and silencing of MUC4 were characterized and evaluated. RESULTS: The prepared molecular probe had a particle size of 61.7 ± 18.5 nm and a surface of 46.7 ± 0.8mV and showed good biocompatibility in vitro and T2 relaxation efficiency. It can also load and protect siRNA. PEI-SPION-siRNA showed a good silencing effect on MUC4. CONCLUSION: PEI-SPION-siRNA may be beneficial as a novel theranostic tool for PC.