Differential expression of MUC genes in endometrial and cervical tissues and tumors

Pathological features of gastric‑type endocervical adenocarcinoma: A report of two cases

Gastric-type endocervical adenocarcinoma (GEA) is an uncommon form of uterine cervical adenocarcinoma with an unfavorable prognosis. The tumor consists of glands exhibiting a morphological resemblance to gastric cells and occasionally manifests features akin to pancreaticobiliary mucinous adenocarcinoma. GEA differs from the typical cervical cancer, particularly in its lack of association with the human papillomavirus. Immunophenotypic analysis suggests intestinal differentiation. The present study reports two cases of GEA occurring in postmenopausal individuals who were diagnosed in Lishui Central Hospital (Lishui, China) between January 2015 and January 2023. Microscopic examination revealed cysts lined with mucinous cells within the tumors. Immunohistochemical assays confirmed the positivity of the tumors for cytokeratin 7, mucin (MUC)5AC, and mutant tumor protein p53, while the results were negative for tumor suppressor p16, and in one case for paired box protein 8, consistent with characteristics of mucinous adenocarcinoma originating from the gastrointestinal tract. Programmed death-ligand 1 expression was also negative. The proto-oncogene K-ras was identified using amplification refractory mutation system polymerase chain reaction. Both cases were negative for mutations in codons 12 and 13 of exon 2, codon 61 of exon 3 and codon 146 of exon 4, but were positive for wild-type K-ras. Clinical follow-up revealed a potential association between histopathological features and resistance to chemotherapeutic drugs. The infrequency of this tumor type may contribute to diagnostic challenges.

Investigating the relationship between the cervical mucoprotein levels and cervical intraepithelial neoplasia

BACKGROUND

Cervical cancer has been ranked as the fourth most common cancer in women. The role of HPV, the DNA virus identified in the 1980s, in almost all cervical cancers is undisputed. In patients scanned with smear and HPV, a cervical biopsy is performed accompanied by colposcopic examination, and the lesion is defined. The concentration of mucoproteins varies in the structure of the cervical mucus with neoplasms. The major aim of this study was to investigate the changes in the levels of cervical mucoprotein in patients at the early stages of cervical cancer and evaluate if these levels can be used in the early diagnosis of this cancer type.

METHODS

The study was designed as a prospective cohort study. Samples from cervical mucus were taken and stored before colposcopy examination of human papillomavirus (HPV) positive patients (N.=100). According to the pathology results, while 36 cases constituted the precancerous group, no suspicion of cancer was found in 64 cases. To ensure standardization, colposcopy was performed immediately after the menstrual cycle and at least 0.5 mL of the cervical mucus sample was taken from all individual patients used in this study. Cervical mucus samples of the patients were analyzed for mucoproteins MUC1, MUC2, MUC5AC and MUC5B.

RESULTS

All mucoprotein levels were found to be higher in patients with cervical intraepithelial neoplasia (CIN) than those of subjects with normal pathology for cervical neoplasia.

CONCLUSIONS

Significant relationship was obtained between cervical intraepithelial neoplasms and the levels of mucoproteins in cervical mucus. The results showed that diagnosis of neoplasia with HPV may be easily performed by utilizing any mucoprotein test.

Mucins as contrast agent targets for fluorescence-guided surgery of pancreatic cancer

Pancreatic cancer is difficult to resect due to its unique challenges, often leading to incomplete tumor resections. Fluorescence-guided surgery (FGS), also known as intraoperative molecular imaging and optical surgical navigation, is an intraoperative tool that can aid surgeons in complete tumor resection through an increased ability to detect the tumor. To target the tumor, FGS contrast agents rely on biomarkers aberrantly expressed in malignant tissue compared to normal tissue. These biomarkers allow clinicians to identify the tumor and its stage before surgical resection and provide a contrast agent target for intraoperative imaging. Mucins, a family of glycoproteins, are upregulated in malignant tissue compared to normal tissue. Therefore, these proteins may serve as biomarkers for surgical resection. Intraoperative imaging of mucin expression in pancreatic cancer can potentially increase the number of complete resections. While some mucins have been studied for FGS, the potential ability to function as a biomarker target extends to the entire mucin family. Therefore, mucins are attractive proteins to investigate more broadly as FGS biomarkers. This review summarizes the biomarker traits of mucins and their potential use in FGS for pancreatic cancer.

Mechanism of endometrial MUC2 in reproductive performance in mice through PI3K/AKT signaling pathway after lipopolysaccharide treatment

The objective of this study was to investigate the effects of exposure to endotoxin on the reproductive performance of humans and animals in pregnancy and delivery period. Mucin is considered to play a critical role in protecting the tissue epithelium. At pregnancy period, the MUC2 expression of uterus in the High LPS group was significantly higher than that in the Control group. The glycosaminoglycans of gland cells were secreted into the uterine cavity to protect the uterus. Then, the MUC2 layer became thinner, and LPS entered the lamina propria of the uterus. The mRNA expression of tight junction proteins showed a marked drop, and morphological damage of the uterus occurred. Subsequently, the glycosaminoglycans of gland cells in the High LPS and Low LPS groups increased with the increasing LPS dose, and the damage to the endometrial epithelium was repaired in female mice at Day 5 postdelivery. A low dose of LPS activated the PI3K/AKT signaling pathways to increase the glycosaminoglycans particles, while a high dose of LPS inhibited the PI3K/AKT signaling pathway to decrease the glycosaminoglycans particles. Taken together, our results suggest that gland cells secreted glycosaminoglycans particles into the uterine cavity by exocytosis to increase the thickness of the mucus layer to protect the uterus and that this process was regulated by PI3K/AKT signaling pathways.

Infertile human endometrial organoid apical protein secretions are dysregulated and impair trophoblast progenitor cell adhesion

INTRODUCTION

Embryo implantation failure leads to infertility. As an important approach to regulate implantation, endometrial epithelial cells produce and secrete factors apically into the uterine cavity in the receptive phase to prepare the initial blastocyst adhesion and implantation. Organoids were recently developed from human endometrial epithelium with similar apical-basal polarity compared to endometrial gland making it an ideal model to study endometrial epithelial secretions.

METHODS

Endometrial organoids were established using endometrial biopsies from women with primary infertility and normal fertility. Fertile and infertile organoids were treated with hormones to model receptive phase of the endometrial epithelium and intra-organoid fluid (IOF) was collected to compare the apical protein secretion profile and function on trophoblast cell adhesion.

RESULTS

Our data show that infertile organoids were dysregulated in their response to estrogen and progesterone treatment. Proteomic analysis of organoid apical secretions identified 150 dysregulated proteins between fertile and infertile groups (>1.5-fold change). Trophoblast progenitor spheroids (blastocyst surrogates) treated with infertile organoid apical secretions significantly compromised their adhesion to organoid epithelial cell monolayers compared to fertile group (P < 0.0001).

DISCUSSION

This study revealed that endometrial organoid apical secretions alter trophoblast cell adhesiveness relative to fertility status of women. It paves the way to determine the molecular mechanisms by which endometrial epithelial apical released factors regulate blastocyst initial attachment and implantation.

MUC5AC Expression in Various Tumor Types and Nonneoplastic Tissue: A Tissue Microarray Study on 10 399 Tissue Samples

Background: Mucin 5AC (MUC5AC) belongs to the glycoprotein family of secreted gel-forming mucins and is physiologically expressed in some epithelial cells. Studies have shown that MUC5AC is also expressed in several cancer types suggesting a potential utility for the distinction of tumor types and subtypes. Methods: To systematically determine MUC5AC expression in normal and cancerous tissues, a tissue microarray containing 10 399 samples from 111 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. Results: MUC5AC was expressed in normal mucus-producing cells of various organs. At least weak MUC5AC positivity was seen in 44 of 111 (40%) tumor entities. Of these 44 tumor entities, 28 included also tumors with strong positivity. MUC5AC immunostaining was most commonly seen in esophageal adenocarcinoma (72%), colon adenoma (62%), ductal adenocarcinoma of the pancreas (64%), mucinous carcinoma of the ovary (46%), diffuse gastric adenocarcinoma (44%), pancreatic ampullary adenocarcinoma (41%), intestinal gastric adenocarcinoma (39%), and bronchioloalveolar carcinoma (33%). Clinically relevant tumors with complete or almost complete absence of MUC5AC staining included small cell carcinoma of the lung (0% of 17), clear cell renal cell carcinoma (0% of 507), papillary thyroid carcinoma (0% of 359), breast cancer (2% of 1097), prostate cancer (2% of 228), soft tissue tumors (0.1% of 968), and hematological neoplasias (0% of 111). Conclusion: The highly standardized analysis of a broad range of cancers identified a ranking order of tumors according to their relative prevalence of MUC5AC expression.

Glycosylation in Cervical Cancer: New Insights and Clinical Implications

Cervical cancer has become the most frequent female malignancy and presents as a general health challenge in many countries undergoing economic development. Various human papillomaviruses (HPV) types have appeared as one of the most critically identifiable causes of widespread cervical cancers. Conventional cervical cytological inspection has limitations of variable sensitivity according to cervical cytology. Glycobiology has been fundamental in related exploration in various gynecologic and reproductive fields and has contributed to our understanding of cervical cancer. It is associated with altered expression of N-linked glycan as well as abnormal expression of terminal glycan structures. The analytical approaches available to determine serum and tissue glycosylation, as well as potential underlying molecular mechanisms involved in the cellular glycosylation alterations, are monitored. Moreover, cellular glycosylation influences various aspects of cervical cancer biology, ranging from cell surface expressions, cell-cell adhesion, cancer signaling, cancer diagnosis, and management. In general, discoveries in glycan profiling make it technically reproducible and affordable to perform serum glycoproteomic analyses and build on previous work exploring an expanded variety of glycosylation markers in the majority of cervical cancer patients.

Claudin-6 is down-regulated in gastric cancer and its potential pathway

Claudins are indispensible in modulating the permeability of epithelial and endothelial cells and in the maintenance of cell polarity. In order to verify the function of claudin-6 in the development of gastric cancer, we investigated claudin-6 expression in different gastric disease tissues. Moreover, we further explored whether overexpression of claudin-6 altered proliferation, apoptosis, migration, invasiveness, differentiation in BGC-823 cells and the potential mechanism. Immunohistochemistry was performed to detect the in situ expression of claudin-6 in different gastric disease tissues; moreover, cell culture, real-time PCR and western blot were used to evaluate the effect of overexpression of claudin-6 in vitro and the related mechanism. The results of immunohistochemical staining showed that the positivity of claudin-6 was significantly higher in superficial gastritis than that in gastric cancer. Overexpression of claudin-6 induced differentiation of BGC-823 cells by inhibiting the JNK pathway. However, it had no effect on proliferation, apoptosis, migration or invasiveness in vitro. The expression of claudin-6 was decreased in gastric cancer. Overexpression of claudin-6 induced differentiation of gastric cancer cells by inhibiting the JNK pathway.

MUC Glycoproteins: Potential Biomarkers and Molecular Targets for Cancer Therapy

MUC proteins have great significance as prognostic and diagnostic markers as well as a potential target for therapeutic interventions in most cancers of glandular epithelial origin. These are high molecular weight glycosylated proteins located in the epithelial lining of several tissues and ducts. Mucins belong to a heterogeneous group of large O-glycoproteins that can be either secreted or membrane-bound. Glycosylation, a post-translational modification affects the biophysical, functional and biochemical properties and provides structural complexity for these proteins. Aberrant expression and glycosylation of mucins contribute to tumour survival and proliferation in many cancers, which in turn activates numerous signalling pathways such as NF-kB, ERα, HIF, MAPK, p53, c-Src, Wnt and JAK-STAT, etc. This subsequently induces cancer cell growth, proliferation and metastasis. The present review mainly demonstrates the functional aspects of MUC glycoproteins along with its unique signalling mechanism and role of aberrant glycosylation in cancer progression and therapeutics. The importance of MUC proteins and its subtypes in a wide spectrum of cancers including but not limited to breast cancer, colorectal cancer, endometrial and cervical cancer, lung cancer, primary liver cancer, pancreatic cancer, prostate cancer and ovarian cancer has been exemplified with significance in targeting the same. Several patents associated with the MUC proteins in the field of cancer therapy are also emphasized in the current review.

AGR2-induced glucose metabolism facilitated the progression of endometrial carcinoma via enhancing the MUC1/HIF-1α pathway

Anterior gradient 2 (AGR2) was proved to modulate cancer progression. However, the role of AGR2 on endometrial cancer was not established. Here, we investigated the effects of AGR2 expression on endometrial cancer and explored the regulation mechanism. In the study, we found that AGR2 was overexpressed in tumor tissues of 30 endometrial cancer patients. A high level of AGR2 promoted endometrial cancer cells proliferation, migration and invasion. AGR2 induced the expression of lactate dehydrogenase A (LDHA), phosphoglycerate kinase 1 (PGK1), kallikrein 2 (HK2), and enolase 1-α (ENO1), glucose uptake and lactate production. AGR2 could bind to MUC1 and induce MUC1 and hypoxia-inducible factor 1α (HIF-1α). The inhibition effects of AGR2 knockdown on cells proliferation, migration and invasion ability were abolished by the overexpression of MUC1. Besides, the overexpression of MUC1 also reversed the inhibition effects of AGR2 knockdown on the expression of LDHA, HK2, PGK1 and ENO1, glucose uptake and lactate production. AGR2 knockdown inhibited tumor growth, the levels of Ki-67, MUC1, HIF-1α and glycolysis. In conclusion, AGR2 was overexpressed in endometrial cancer and AGR2-induced glucose metabolism facilitated the progression of endometrial carcinoma via the MUC1/HIF-1α pathway. AGR2 may be an effective therapeutic target for endometrial carcinoma.

Mucins and Pathogenic Mucin-Like Molecules Are Immunomodulators During Infection and Targets for Diagnostics and Vaccines

Mucins and mucin-like molecules are highly O-glycosylated proteins present on the cell surface of mammals and other organisms. These glycoproteins are highly diverse in the apoprotein and glycan cores and play a central role in many biological processes and diseases. Mucins are the most abundant macromolecules in mucus and are responsible for its biochemical and biophysical properties. Mucin-like molecules cover various protozoan parasites, fungi and viruses. In humans, modifications in mucin glycosylation are associated with tumors in epithelial tissue. These modifications allow the distinction between normal and abnormal cell conditions and represent important targets for vaccine development against some cancers. Mucins and mucin-like molecules derived from pathogens are potential diagnostic markers and targets for therapeutic agents. In this review, we summarize the distribution, structure, role as immunomodulators, and the correlation of human mucins with diseases and perform a comparative analysis of mucins with mucin-like molecules present in human pathogens. Furthermore, we review the methods to produce pathogenic and human mucins using chemical synthesis and expression systems. Finally, we present applications of mucin-like molecules in diagnosis and prevention of relevant human diseases.

The prognostic significance of preoperative serum cancer antigen 15-3 levels in endometrial carcinomas

OBJECTIVES

To determine the associations between serum cancer antigen 15-3 levels and prognostic factors in patients with endometrial carcinomas. Additionally, we investigated the clinical utility of serum cancer antigen 15-3 levels in the selection of low-risk patients with endometrioid type, tumor size less than 2 cm, myometrial invasion ≤50%, and histological grade 1-2. Methods: Ninety-six patients, who were surgically staged at  Ankara Yildirim Beyazit University, Ankara, Turkey, between 2007 and 2016, were retrospectively analyzed. Demographic, clinical, and surgical characteristics were retrieved from the patients' hospital records. A p less than 0.05 was considered significant. Results: Fifteen patients had advanced (≥Stage II) disease, 14 patients had Type 2 histology, 20 patients had Grade 3 tumors, 23 patients had lymphovascular space invasion, and 10 patients had positive lymph node involvement. Serum cancer antigen 15-3 levels were significantly higher in patients with advanced (≥Stage II) disease, Type 2 histology, Grade 3 tumors, lymphovascular space invasion, and positive lymph node involvement (p less than 0.05). Serum cancer antigen 15-3 levels were also significantly correlated with tumor size (p=0.006). Serum cancer antigen 15-3 levels were significantly lower (95% confidence interval: 0.57-0.79; p=0.03) in low-risk patients compared to other endometrial carcinoma patients. A cutoff of 25.0 IU/mL was used to identify high-risk patients with a specificity of 100%. Conclusion: Serum cancer antigen 15-3 levels significantly correlated with prognostic factors and were a useful diagnostic tool for endometrial carcinomas.

In vivo imaging of the Muc5b gel-forming mucin

Gel-forming mucins are macromolecules produced by goblet cells and responsible for the mucus gel formation. Changes in goblet cell density and in gel-forming mucin production have emerged as sensitive indicators for mucosal diseases. A Muc5b-GFP tagged reporter mouse was used to assess Muc5b production in mouse tissues by immunofluorescence microscopy and fluorescent activity using stereromicroscopy and probe-based confocal laser endomicroscopy. Muc5b production was followed longitudinally by recording the fluorescent activity in vagina and in embryonic lung explants under stimulation by interleukin 13. We show that the GFP is easily visualized in the mouse adult ear, nose, trachea, gallbladder, and cervix. Live Muc5b is also easily monitored in the nasal cavity, trachea and vagina where its production varies during the estrus cycle with a peak at the proestrus phase and in pregnant mice. Explant culture of reporter mouse embryonic whole lung shows that interleukin 13 stimulates Muc5b production. The transgenic Muc5b-GFP mouse is unique and suitable to study the mechanisms that regulate Muc5b production/secretion and mucous cell differentiation by live imaging and can be applied to test drug efficacy in mucosal disease models.

MUC1 stimulates EGFR expression and function in endometrial cancer

The current standard of care for endometrial cancer patients involves hysterectomy with adjuvant radiation and chemotherapy, with no effective treatment for advanced and metastatic disease. MUC1 is a large, heavily glycosylated transmembrane protein that lubricates and protects cell surfaces and increases cellular signaling through the epidermal growth factor receptor (EGFR). We show for the first time that MUC1 stimulates EGFR expression and function in endometrial cancer. siRNA knockdown and CRISPR/Cas knockout of MUC1 reduced EGFR gene expression, mRNA, protein levels and signaling. MUC1 bound strongly to two regions of the EGFR promoter: -627/-511 and -172/-64. MUC1 knockout also reduced EGFR-dependent proliferation in two dimensional culture, as well as growth and survival in three dimensional spheroid cultures. MUC1 knockout cells were more sensitive to the EGFR inhibitor, lapatinib. Finally, MUC1 and EGFR co-expression was associated with increased cellular proliferation in human endometrial tumors. These data demonstrate the importance of MUC1-driven EGFR expression and signaling and suggest dual-targeted therapies may provide improved response for endometrial tumors.

ECGene: A Literature-Based Knowledgebase of Endometrial Cancer Genes

Endometrial cancer (EC) ranks as the sixth common cancer for women worldwide. To better distinguish cancer subtypes and identify effective early diagnostic biomarkers, we need improved understanding of the biological mechanisms associated with EC dysregulated genes. Although there is a wealth of clinical and molecular information relevant to EC in the literature, there has been no systematic summary of EC‐implicated genes. In this study, we developed a literature‐based database ECGene (Endometrial Cancer Gene database) with comprehensive annotations. ECGene features manual curation of 414 genes from thousands of publications, results from eight EC gene expression datasets, precomputation of coexpressed long noncoding RNAs, and an EC‐implicated gene interactome. In the current release, we generated and comprehensively annotated a list of 458 EC‐implicated genes. We found the top‐ranked EC‐implicated genes are frequently mutated in The Cancer Genome Atlas (TCGA) tumor samples. Furthermore, systematic analysis of coexpressed lncRNAs provided insight into the important roles of lncRNA in EC development. ECGene has a user‐friendly Web interface and is freely available at http://ecgene.bioinfo‐minzhao.org/. As the first literature‐based online resource for EC, ECGene serves as a useful gateway for researchers to explore EC genetics.

Exploring the role and diversity of mucins in health and disease with special insight into non-communicable diseases

Mucins are major glycoprotein components of the mucus that coats the surfaces of cells lining the respiratory, digestive, gastrointestinal and urogenital tracts. They function to protect epithelial cells from infection, dehydration and physical or chemical injury, as well as to aid the passage of materials through a tract i.e., lubrication. They are also implicated in the pathogenesis of benign and malignant diseases of secretory epithelial cells. In Human there are two types of mucins, membrane-bound and secreted that are originated from mucous producing goblet cells localized in the epithelial cell layer or in mucous producing glands and encoded by MUC gene. Mucins belong to a heterogeneous family of high molecular weight proteins composed of a long peptidic chain with a large number of tandem repeats that form the so-called mucin domain. The molecular weight is generally high, ranging between 0.2 and 10 million Dalton and all mucins contain one or more domains which are highly glycosylated. The size and number of repeats vary between mucins and the genetic polymorphism represents number of repeats (VNTR polymorphisms), which means the size of individual mucins can differ substantially between individuals which can be used as markers. In human it is only MUC1 and MUC7 that have mucin domains with less than 40% serine and threonine which in turn could reduce number of PTS domains. Mucins can be considered as powerful two-edged sword, as its normal function protects from unwanted substances and organisms at an arm's length while, malfunction of mucus may be an important factor in human diseases. In this review we have unearthed the current status of different mucin proteins in understanding its role and function in various non-communicable diseases in human with special reference to its organ specific locations. The findings described in this review may be of direct relevance to the major research area in biomedicine with reference to mucin and mucin associated diseases.

IPA Analysis of Cervicovaginal Fluid from Precancerous Women Points to the Presence of Biomarkers for the Precancerous State of Cervical Carcinoma

Despite large gaps in our knowledge on the intracellular mechanism leading to cervical cancer, the pathways induced by oncogenic high-risk Human Papilloma Virus (HPV) and those finally causing cervical cancer are increasingly being unraveled. Assuming that precancerous tissue is recognized and lysed by the immune system—which is in many cases incomplete because of the counteraction by the HPV virus—we hypothesize that several intracellular factors, involved in induction and development of precancerous lesions and/or cervical cancer are being released into the cervicovaginal fluid (CVF). These factors can then be seen as markers for the precancerous state, and when they persist they are indicative for an increased risk for cervical carcinoma. In a previous study, we analyzed the proteomic profiles of six CVF samples from women with different stages of precancerous lesions and compared these with the CVF proteomes from healthy women. Here, we extend these observations by investigating these proteomes by Ingenuity Pathway Analysis (IPA). We show that proteins in CVF from precancerous women are clearly more involved in pathways that make up the ‘hallmarks of cancer’, as compared to CVF proteins from healthy persons. Moreover, after literature search, proteins classified by IPA in the ‘cancer’ category, were more correlated with cervical cancer when they originated from CVF from precancerous women. Many of these proteins formed a network with angiotensin II as central mediator. The search for ‘network biomarkers’, rather than single biomarkers, could drastically increase specificity, sensitivity and prognostic value of cervical cancer diagnosis, making use of an easy to handle fluid, the CVF.

Expression of the transmembrane mucins, MUC1, MUC4 and MUC16, in normal endometrium and in endometriosis

STUDY QUESTION

Are the transmembrane mucins, MUC1, MUC4 and MUC16, differentially expressed in endometriosis compared with normal endometrium?

SUMMARY ANSWER

This study revealed that transmembrane mucin expression does not vary significantly in normal endometrium during the menstrual cycle and is not altered in endometriosis relative to the epithelial marker, cytokeratin-18 (KRT18).

WHAT IS KNOWN ALREADY

Increased serum levels of the transmembrane mucin fragments MUC1, MUC4 and MUC16 that normally dominate the apical surface of simple epithelia are found in several pathological conditions, including endometriosis. Altered mucin expression in gynecologic diseases may promote infertility or endometrial pathologies.

STUDY DESIGN, SIZE, DURATION

This was a laboratory-based study of samples from 12 endometriosis patients as well as non-endometriosis control samples obtained from 31 patients.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Total RNA was isolated from endometrial biopsies of ectopic and eutopic endometrium from women with endometriosis and control patients from different stages of the menstrual cycle. Quantitative (q)-RT-PCR analyses were performed for the mucins, MUC1, MUC4 and MUC16, relative to the epithelial marker, cytokeratin-18 (KRT18), or β-actin (ACTB). Frozen sections from endometrial biopsies of proliferative and mid-secretory stage women with endometriosis were immunostained for MUC1, MUC4 and MUC16.

MAIN RESULTS AND THE ROLE OF CHANCE

qRT-PCR analyses of MUC1 and MUC16 mRNA revealed that these mucins do not vary significantly during the menstrual cycle nor are they altered in women with endometriosis relative to the epithelial marker, KRT18. MUC4 mRNA is expressed at very low levels relative to MUC1 and MUC16 under all conditions. There was little difference in MUC1 and MUC16 expression between eutopic endometrial and ectopic endometriotic tissues. MUC4 expression also was not significantly higher in the ectopic endometriotic tissues. Immunostaining for all three mucins reveals robust expression of MUC1 and MUC16 at the apical surfaces of endometrial epithelia, but little to no staining for MUC4.

LIMITATIONS, REASONS FOR CAUTION

qRT-PCR analysis was the main method used for mucin detection. Additional studies with stage III-IV endometriotic tissue would be useful to determine if changes in MUC1 and MUC16 expression occur, or if MUC4 expression increases, at later stages of endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

We report a comprehensive comparative profile of the major transmembrane mucins, MUC1, MUC4 and MUC16, relative to the epithelial marker, KRT18, in normal cycling endometrium and in endometriosis, and indicate constitutive expression. Previous studies have profiled the expression of individual mucins relative to β-actin and indicate accumulation in the luteal phase. Thus, these differences in interpretation appear to reflect the increased epithelial content of endometrium during the luteal phase.

STUDY FUNDING

This study was supported by: NIH R01HD29963 to D.D.C.; NIH U54HD007495 to S.M.H.; and NIH R01HD067721 to S.L.Y. and B.A.L. The authors have no competing interests to declare.

Candidate biomarkers for cervical cancer treatment: Potential for clinical practice (Review)

Cervical cancer ranks high among the causes of female cancer mortalities and is an important disease in developing and developed countries. Current diagnosis of cervical cancer depends on colposcopy, pathological diagnosis and preoperative diagnosis using methods, including magnetic resonance imaging and computed tomography. Advanced cervical cancer has a poor prognosis. The tumor marker squamous cell carcinoma is conventionally used for screening, but recent studies have revealed the mechanisms of carcinogenesis and the factors associated with a poor prognosis in cervical cancer. These include epigenetic biomarkers, with the methylation level of the checkpoint with forkhead and ring finger gene being potentially useful for predicting the malignancy of cervical cancer and sensitivity to treatment with paclitaxel. The extent of methylation of the Werner DNA helicase gene is also useful for determining sensitivity to an anticancer agent, CPT-11. In addition to epigenetic changes, the expression levels of hypoxia-inducible factor 1α subunit, epidermal growth factor receptor and cyclooxygenase-2 have been reported as possible biomarkers in cervical cancer. Novel prognostic factors, including angiogenic factors, fragile histidine triad, thymidylate synthase, glucose-related protein 58 and mucin antigens, have also been described, and hemoglobin and platelets may also be significant prognostic biomarkers. Utilization of these biomarkers may facilitate personalized treatment and improved outcomes in cervical cancer.

Human female genital tract infection by the obligate intracellular bacterium Chlamydia trachomatis elicits robust Type 2 immunity

While Chlamydia trachomatis infections are frequently asymptomatic, mechanisms that regulate host response to this intracellular Gram-negative bacterium remain undefined. This investigation thus used peripheral blood mononuclear cells and endometrial tissue from women with or without Chlamydia genital tract infection to better define this response. Initial genome-wide microarray analysis revealed highly elevated expression of matrix metalloproteinase 10 and other molecules characteristic of Type 2 immunity (e.g., fibrosis and wound repair) in Chlamydia-infected tissue. This result was corroborated in flow cytometry and immunohistochemistry studies that showed extant upper genital tract Chlamydia infection was associated with increased co-expression of CD200 receptor and CD206 (markers of alternative macrophage activation) by endometrial macrophages as well as increased expression of GATA-3 (the transcription factor regulating T_H2 differentiation) by endometrial CD4⁺ T cells. Also among women with genital tract Chlamydia infection, peripheral CD3⁺ CD4⁺ and CD3⁺ CD4^- cells that proliferated in response to ex vivo stimulation with inactivated chlamydial antigen secreted significantly more interleukin (IL)-4 than tumor necrosis factor, interferon-γ, or IL-17; findings that repeated in T cells isolated from these same women 1 and 4 months after infection had been eradicated. Our results thus newly reveal that genital infection by an obligate intracellular bacterium induces polarization towards Type 2 immunity, including Chlamydia-specific T_H2 development. Based on these findings, we now speculate that Type 2 immunity was selected by evolution as the host response to C. trachomatis in the human female genital tract to control infection and minimize immunopathological damage to vital reproductive structures.

MUC20 overexpression predicts poor prognosis and enhances EGF-induced malignant phenotypes via activation of the EGFR-STAT3 pathway in endometrial cancer

OBJECTIVE

Mucins play a critical role in the malignancy of various tumors and have been identified as diagnostic markers and as attractive therapeutic targets. However, the role of mucin (MUC) 20 in endometrial cancer (EC) is still unknown.

METHODS

The relationship between MUC20 expression and clinical characteristics of EC was analyzed in 97 EC tumors and 16 normal tissues by immunohistochemistry. Effects of MUC20 on EC cells, HEC-1A and RL95-2, were examined by in vitro cell growth, migration, and invasion assays, as well as in vivo tumor growth in SCID mouse model. Western blotting was performed to analyze signaling pathways modulated by MUC20.

RESULTS

MUC20 expression was significantly higher in EC tumors compared with the normal tissue. High levels of MUC20 expression in EC tumors were correlated with an unfavorable histologic subtype. Furthermore, MUC20 was an independent prognostic factor for poor survival as evaluated by multivariate analyses. Overexpression of MUC20 in EC cells significantly enhanced cell growth, migration, and invasion, as well as tumor growth in vivo. The MUC20-enhanced invasive behavior was significantly blocked by erlotinib, an EGFR inhibitor. Moreover, MUC20 overexpression enhanced EGF-mediated migration and invasion, suggesting a critical role of EGFR in MUC20-mediated effects. We found that MUC20 overexpression could enhance EGF-induced phosphorylation of EGFR and STAT3. Inhibition of the STAT3 activity by its inhibitor Stattic significantly suppressed the MUC20-enhanced invasive behavior.

CONCLUSIONS

MUC20 is novel prognostic factor for EC and its overexpression enhances EGF-triggered invasive behavior through activation of EGFR-STAT3 pathway.

Integrative proteomics and tissue microarray profiling indicate the association between overexpressed serum proteins and non-small cell lung cancer

Lung cancer is the leading cause of cancer deaths worldwide. Clinically, the treatment of non-small cell lung cancer (NSCLC) can be improved by the early detection and risk screening among population. To meet this need, here we describe the application of extensive peptide level fractionation coupled with label free quantitative proteomics for the discovery of potential serum biomarkers for lung cancer, and the usage of Tissue microarray analysis (TMA) and Multiple reaction monitoring (MRM) assays for the following up validations in the verification phase. Using these state-of-art, currently available clinical proteomic approaches, in the discovery phase we confidently identified 647 serum proteins, and 101 proteins showed a statistically significant association with NSCLC in our 18 discovery samples. This serum proteomic dataset allowed us to discern the differential patterns and abnormal biological processes in the lung cancer blood. Of these proteins, Alpha-1B-glycoprotein (A1BG) and Leucine-rich alpha-2-glycoprotein (LRG1), two plasma glycoproteins with previously unknown function were selected as examples for which TMA and MRM verification were performed in a large sample set consisting about 100 patients. We revealed that A1BG and LRG1 were overexpressed in both the blood level and tumor sections, which can be referred to separate lung cancer patients from healthy cases.

Molecular aspects of mucin biosynthesis and mucus formation in the bovine cervix during the periestrous period

Mucus within the cervical canal represents a hormonally regulated barrier that reconciles the need to exclude the vaginal microflora from the uterus during progesterone dominance, while permitting sperm transport at estrus. Its characteristics change during the estrous cycle to facilitate these competing functional requirements. Hydrated mucin glycoproteins synthesized by the endocervical epithelium form the molecular scaffold of this mucus. This study uses the bovine cervix as a model to examine functional groups of genes related to mucin biosynthesis and mucus production over the periestrous period when functional changes in cervical barrier function are most prominent. Cervical tissue samples were collected from 30 estrus synchronized beef heifers. Animals were slaughtered in groups starting 12 h after the withdrawal of intravaginal progesterone releasing devices (controlled internal drug releases) until 7 days postonset of estrus (luteal phase). Subsequent groupings represented proestrus, early estrus, late estrus, metestrus, and finally the early luteal phase. Tissues were submitted to next generation RNA-seq transcriptome analysis. We identified 114 genes associated with biosynthesis and intracellular transport of mucins, and postsecretory modifications of cervical; 53 of these genes showed at least a twofold change in one or more experimental group in relation to onset of estrus, and the differences between groups were significant ( P < 0.05). The majority of these genes showed the greatest alteration in their expression in the 48 h postestrus and luteal phase groups.

Mucins and toll-like receptors: kith and kin in infection and cancer

Inflammation is underlying biological phenomenon common in infection and cancer. Mucins are glycoproteins which establish a physical barrier for undesirable entry of foreign materials through epithelial surfaces. A deregulated expression and an anomalous glycosylation pattern of mucins are known in large number of cancers. TLRs are class of receptors which recognize the molecular patterns of invading pathogens and activate complex inflammatory pathways to clear them. Aberrant expression of TLRs is observed in many cancers. A highly orchestrated action of mucins and TLRs is well evolved host defence mechanism; however, a link between the two in other non-infectious conditions has received less attention. Here we present an overview as to how mucins and TLRs give protection to the host and are deregulated during carcinogenesis. Further, we propose the possible mechanisms of cross-regulation between them in pathogenesis of cancer. As both mucins and TLRs are therapeutically important class of molecules, an understanding of the underlying molecular mechanisms connecting the two will open new avenues for the therapeutic targeting of cancer.

AP2alpha is essential for MUC8 gene expression in human airway epithelial cells

Mucins are high molecular weight proteins that make up the major components of mucus. Hypersecretion of mucus is a feature of several chronic inflammatory airway diseases. MUC8 is an important component of airway mucus, and its gene expression is upregulated in nasal polyp epithelium. Little is known about the molecular mechanisms of MUC8 gene expression. We first observed overexpression of activator protein-2 alpha (AP2 alpha) in human nasal polyp epithelium. We hypothesized that AP2 alpha overexpression in nasal polyp epithelium correlates closely with MUC8 gene expression. We demonstrated that phorbol 12-myristate 13-acetate (PMA) treatment of the airway epithelial cell line NCI-H292 increases MUC8 gene and AP2 alpha expression. In this study, we sought to determine which signal pathway is involved in PMA-induced MUC8 gene expression. The results show that the protein kinase C and mitogen-activating protein/ERK kinase (MAPK) pathways modulate MUC8 gene expression. PD98059 or ERK1/2 siRNA and RO-31-8220 or PKC siRNA significantly suppress AP2 alpha as well as MUC8 gene expression in PMA-treated cells. To verify the role of AP2 alpha, we specifically knocked down AP2 alpha expression with siRNA. A significant AP2 alpha knock-down inhibited PMA-induced MUC8 gene expression. While dominant negative AP2 alpha decreased PMA-induced MUC8 gene expression, overexpressing wildtype AP2 alpha increased MUC8 gene expression. Furthermore, using lentiviral vectors for RNA interference in human nasal polyp epithelial cells, we confirmed an essential role for AP2 alpha in MUC8 gene expression. From these results, we concluded that PMA induces MUC8 gene expression through a mechanism involving PKC, ERK1/2, and AP2 alpha activation in human airway epithelial cells.

Intraobserver and interobserver variability in distinguishing between endocervical and endometrial adenocarcinoma on problematic cases of cervical curettings

We conducted a prospective study where 4 pathologists examined patients' problematic cases of cervical curetting for adenocarcinoma to determine whether it is of endocervical or endometrial origin based on 3 parameters: age, morphology, and immunohistochemistry (IHC) panel. Our aims were to evaluate the intraobserver and interobserver variability and to compare the results using those parameters to the final hysterectomy specimens. The value of morphology, morphology+age, and the combined parameters (morphology+age+IHC) in predicting the correct origin of the tumor was evaluated. The intraobserver agreements ranged from fair to almost perfect for each of morphology, morphology+age, and the combined parameters. The interobserver agreements were fair in the first review and ranged from slight to fair in the second review. The agreements between the diagnosis based on morphology, morphology+age, and the combined parameters compared with the final diagnosis on the hysterectomy specimen were slight (kappa=0.137), fair (kappa=0.290), and moderate (kappa=0.497), respectively. We concluded that (i) discriminating between endocervical and endometrial carcinoma is highly subject to intraobserver and interobserver variability. (ii) Surprisingly, this variability is not affected by pathologists' experience. (iii) An IHC panel adds a useful piece of information to predict the tumor origin. Lastly, even though the combination of morphology, age, and IHC is far from perfect in predicting the correct origin of the tumor, it is still the best available method.

Diagnostic value of mucins (MUC1, MUC2 and MUC5AC) expression profile in endoscopic ultrasound-guided fine-needle aspiration specimens of the pancreas

Mucins are aberrantly expressed in various malignancies. We immunohistochemically tested mucins expression (MUC1, MUC2 and MUC5AC) in EUS-FNA samples from pancreatic occupying lesions for the diagnostic utility. The prevalence of MUC1, MUC2 and MUC5AC expression in pancreatic cancers were 77.5% (31/40), 10.0% (4/40) and 80.0% (32/40), respectively, and in the benign pancreatic diseases 25% (4/16), 31.3% (5/16) and 43.8% (7/16). MUC1 and MUC5AC significantly overexpressed in pancreatic cancer, and MUC1 negatively related with tumor differentiation degree (p < 0.05). The prevalence of MUC1, MUC2 and MUC5AC expression in pancreatic mucinous neoplasms were 66.7% (12/18), 38.9% (7/18) and 88.9% (16/18), respectively, and in the pancreatic non-mucinous neoplasms 60.5% (23/38), 5.3% (2/38) and 57.9% (22/38). MUC2 and MUC5AC significantly overexpressed in pancreatic mucinous neoplasms, especially MUC2 in benign mucinous neoplasms (p < 0.05). Compared with cytology alone, the combination test of MUC1+cytology, and MUC5AC+cytology could achieve higher sensitivity (85 vs. 65%, 100 vs. 65%) and accuracy (89.3% vs. 73.2%, 91.1% vs. 73.2%) for pancreatic cancer diagnosis; the combination test of MUC2 + cytology, and MUC5AC + cytology could achieve higher sensitivity (77.8% vs. 38.9%, 100% vs. 38.9%), and specificity (97.4% vs. 60.5%, 71.1% vs. 60.5%) accuracy (100% vs. 51.8%, 80.4% vs. 51.8%) for mucinous neoplasm diagnosis. The panel MUC1+/MUC2-/MUC5AC+/ was higher specific in pancreatic cancer diagnosis, as well as MUC1-/MUC2+/MUC5AC+/ in pancreatic mucinous neoplasms. Our observations suggest the mucins expression profile in EUS-FNA specimens has higher value for the diagnosis of pancreatic cancer and mucinous neoplasms.

Itchy-dry eye associated with polycystic ovary syndrome

PURPOSE

The authors aimed to define the ocular symptomatology of women with polycystic ovaries and hyperandrogenism.

DESIGN

Prospective, observational case series.

METHODS

Of the 62 consecutive patients with an ultrasonographic diagnosis of polycystic ovary (PCO), 16 were identified as having clinical and biochemical signs of hyperandrogenism. All women with a history of ocular symptoms (20/62 total patients [32.3%], 15/16 polycystic ovary syndrome (PCOS) patients [93.7%], and 5/46 PCO patients [10.8%]) underwent a complete eye examination with conjunctival impression cytologic sampling. Clinical measurements of tear function (tear film break-up time [BUT], Schirmer I test) were completed along with analysis of conjunctival goblet cell number, conjunctival immunostaining, and reverse-transcriptase polymerase chain reaction for the mucins MUC1 and MUC5AC. Clinical, histologic, and biochemical data of patients with PCOS were compared statistically with that of patients with PCO and with eight age- and gender-matched healthy controls. Eight of the most severely affected patients received systemic antiandrogen therapy and underwent further ocular evaluation four months after systemic therapy.

RESULTS

Women with PCOS had greater conjunctival hyperemia (P < .001), dryness (P < .001), itching (P < .001), mucous discharge (P < .001), and contact lens intolerance (P < .001) than patients with PCO. Patients with PCOS had a significant reduction of the tear film BUT accompanied by a significant increase in goblet cell number and conjunctival MUC5AC messenger ribonucleic acid expression compared with both PCO patients and healthy subjects.

CONCLUSIONS

Evaluation of the ocular surface should be considered in patients with PCO or PCOS. Women with PCOS were more likely to have itchy-dry eyes, decreased tear film BUT, and increased goblet cell density.

Lack of effective MUC1 tumor antigen-specific immunity in MUC1-transgenic mice results from a Th/T regulatory cell imbalance that can be corrected by adoptive transfer of wild-type Th cells

Glycoprotein tumor Ag MUC1 is overexpressed on the majority of epithelial adenocarcinomas. CTLs that recognize MUC1 and can kill tumor cells that express this molecule have been found in cancer patients, yet they are present in low frequency and unable to eradicate MUC1(+) tumors. Patients also make anti-MUC1 Abs but predominantly of the IgM isotype reflecting the lack of effective MUC1-specific Th responses. Mice transgenic for the human MUC1 gene (MUC1-Tg) are similarly hyporesponsive to MUC1. We used a vaccine consisting of dendritic cells loaded with a long synthetic MUC1 peptide to investigate the fate and function of MUC1-specific CD4(+) Th elicited in wild-type (WT) or MUC1-Tg mice or adoptively transferred from vaccinated WT mice. We show that hyporesponsiveness of MUC1-Tg mice to this vaccine is a result of insufficient expansion of Th cells, while at the same time their regulatory T cells are efficiently expanded to the same extent as in WT mice and exert a profound suppression on MUC1-specific B and T cell responses in vivo. Adoptive transfer of WT Th cells relieved this suppression and enhanced T and B cell responses to subsequent MUC1 immunization. Our data suggest that the balance between Th and regulatory T cells is a critical parameter that could be modulated to improve the response to cancer vaccines.

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