Patterns of episialin/MUC1 expression in endometrial carcinomas and prognostic relevance

In Vitro Assessment of the Expression and T Cell Immunogenicity of the Tumor-Associated Antigens BORIS, MUC1, hTERT, MAGE-A3 and Sp17 in Uterine Cancer

Background: While immunotherapy moved to the forefront of treatment of various cancers, it remains underexplored for uterine cancer. This might be due to the small patient population with advanced endometrial carcinoma and uterine sarcoma. Data about immunotherapeutic targets are scarce in endometrial carcinoma and lacking in uterine sarcoma. Methods: Expression of five tumor-associated antigens (TAA) (BORIS, MUC1, hTERT, MAGE-A3 and Sp17) was validated in uterine tumor samples by immunohistochemistry (IHC) and/or quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). TAA immunogenicity was analyzed by determining spontaneous T cell responses towards overlapping peptide pools covering the whole TAA in patient blood. Results: At mRNA level, MAGE-A3 and Sp17 were overexpressed in a minority of patients and BORIS was moderately overexpressed (26% in endometrial carcinoma and 62% in uterine sarcoma). hTERT was overexpressed in the vast majority of tumors. On protein level, MUC1 was upregulated in primary, recurrent and metastatic EMCAR and in metastatic US tumors. hTERT protein was highly expressed in both normal and malignant tissue. Spontaneous TAA-specific T cell responses were detected in a minority of patients, except for hTERT to which T cell responses occurred more frequently. Conclusions: These data point to MUC1 and hTERT as most suitable targets based on expression levels and T cell immunogenicity for use in immunotherapeutic regimens.

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.

Prognostic Significance of Mucin Antigen MUC1 in Various Human Epithelial Cancers: A Meta-Analysis

Accumulating evidence indicates that mucin antigen MUC1 plays a fundamental role in the initiation and progression of several types of epithelial carcinomas. However, whether the expression of MUC1 on tumor cells is associated with patients' survival remains controversial. Medline/PubMed, EMBASE, the Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) databases, and Grey literature were searched up to 15 August 2015 for eligible studies of the association between the MUC1 expression and overall survival (OS) in various epithelial cancers. The hazard ratio (HR) and its 95% confidence interval (CI) were calculated from the included studies. Moreover, the odds ratio (OR) was also extracted to evaluate the association between the clinicopathological parameters of participants and MUC1 expression. A total of 3425 patients covering 23 studies were included in the analysis. The pooled results showed that positive MUC1 staining was a negative predictor of OS (HRFEM = 1.98,95% CIFEM: 1.76-2.22, PFEM = 0.479; HRREM = 2.16,95% CIREM: 1.58-2.94, PREM = 0.355) in various epithelial carcinomas. Subgroup analysis revealed that the increased MUC1 expression was significantly associated with poor OS in patients with gastric cancer (HRFEM = 2.12, 95%CIFEM: 1.75-2.57, PFEM = 0.359; HRREM = 1.89, 95% CIREM: 1.05-3.41, PREM = 0.238), colorectal cancer (HRFEM = 1.73, 95%CIFEM: 1.41-2.13, PFEM = 0.048; HRREM = 2.00,95% CIREM: 1.46-2.73, PREM = 0.019), cholangiocarcinoma (HRFEM = 2.52, 95% CIFEM: 1.42-4.49, PFEM = 0.252; HRREM = 2.34, 95% CIREM: 1.30-4.22, PREM = 0.244), and nonsmall cell lung cancer (NSCLC) (HRFEM = 2.14, 95% CIFEM: 1.46-3.14, PFEM = 0.591; HRREM = 2.81, 95% CIREM: 1.40-5.64, PREM = 0.280). In addition, MUC1 overexpression was more likely to be found in colorectal cancer patients with an advanced tumor node metastasis stage (ORREM = 1.55, 95% CIREM: 1.06-2.27; PREM = 0.187) and in gastric cancer patients with positive lymph node metastasis (ORREM = 2.37, 95% CIREM: 1.19-4.73; PREM = 0.004) and intestinal-type classification (ORREM = 2.34, 95% CIREM: 1.59-3.45; PREM = 0.767). Our findings provide evidence that MUC1 detection has a prognostic value in patients with epithelial-originated cancers, especially in NSCLC and gastrointestinal cancers.

Dendritic cell immunotherapy in uterine cancer

Uterine cancer is the most common pelvic gynecological malignancy. Uterine sarcomas and relapsed uterine carcinomas have limited treatment options. The search for new therapies is urgent. Dendritic cell (DC) immunotherapy holds much promise, though has been poorly explored in uterine cancer. This commentary gives an insight in existing DC immunotherapy studies in uterine cancer and summarizes the possibilities and the importance of the loading of tumor antigens onto DC and their subsequent maturation. However, the sole application of DC immunotherapy to target uterine cancer will be insufficient because of tumor-induced immunosuppression, which will hamper the establishment of an effective anti-tumor immune response. The authors give an overview on the limited existing immunosuppressive data and propose a novel approach on DC immunotherapy in uterine cancer.

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.

Detection of glycosylated proteins in rabbit oviductal isthmus and uterine endometrium during early embryo development

In this study, lectin histochemistry was performed on paraffin sections to compare carbohydrate expression of oviductal isthmus and uterine endometrium in rabbits during early embryo development. Rabbit embryos are surrounded not only by the zona pellucida but also by tubal secretion-derived mucinous coat material, the mucin coat. Twenty sexually mature females were euthanized at 0 (pre-ovulatory group) and 24, 72 and 96 h after insemination (pseudopregnancy group). The following lectin-binding agents were used: Arachis hypogaea, Peanut (PNA) to label galactosyl (β-1,3)N- acetyl-galactosamine, Dolichos biflorus Agglutinin (DBA) to label galactosyl (β-1,4)N- acetyl-galactosamine, Lens curinaris (LCA) to label α--mannose, α-d-glucose and Pisum sativum agglutinin (PSA) to label α-d-mannose, α-d-glucose. Blood was collected by cardiac puncture, and direct enzyme immunoassay technique was used to measure progesterone concentration. A significant increase in total plasma progesterone concentrations was detected at 96 h post-ovulation when compared with 0, 24 and 72 h post-ovulation (2.9 ± 0.5 vs 0.5 ± 0.15, 1.6 ± 0.5 and 1.5 ± 0.4 ng/ml, at 96 h vs 0, 24 and 72 h post-ovulation, respectively). No differences between pre-ovulatory and pseudopregnant females were observed for glycoprotein localization in isthmus. In contrast, in the endometrium, differences in the glycoprotein detection between pre-ovulatory and pseudopregnant stages were detected. PNA to label galactosyl (β-1,3)N- acetyl-galactosamine was not detected at the pre-ovulatory stage, but its presence was detected at 24 h after ovulation. Both PSA and LCA to label α-d-mannose, α-d-glucose were only detected at 72 h after ovulation. DBA detection was similar for all stages of the reproductive cycle. Therefore, N-acetyl-galactosamine secreted from isthmus could be involved in the formation of the embryonic mucin coat. d-galactose (PNA), d-glucose and d-mannose (PSA and LCA) might be crucial for the implantation period.

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.

Host response in tumor diagnosis and prognosis: importance of immunologists and pathologists alliance

Pathologists and immunologists have collaborated over many years in their efforts to understand and properly diagnose cancer. The ability of pathologists to correctly diagnose this disease was facilitated by the development of immunohistology that utilized specificity of antibodies to distinguish between normal cells and cancer cells. Further boost was provided through the advent of monoclonal antibodies. The two disciplines are now together on the brink of a paradigm shift resulting from a better understanding of the importance for cancer diagnosis and prognosis to consider not only the characteristics of the cancer cells, but also the cancer microenvironment reflecting the host response to the disease. This new immunology and pathology alliance named "Immunoscore" will advance research in both disciplines as well as benefit patients.

Perineal use of talcum powder and endometrial cancer risk

BACKGROUND

Several studies have reported a positive association between perineal use of talcum powder among adult women and ovarian cancer risk. However, the relationship between talcum powder use and other gynecologic malignancies such as endometrial cancer has not been examined, and little information is available on nonhormonal risk factors for endometrial cancer.

METHODS

Perineal use of talcum powder was assessed in 1982 in the Nurses' Health Study. Approximately 40% of women who responded to the questions about perineal use of talcum powder reported ever use. Cox proportional hazards models were used to estimate the incidence rate ratio of endometrial cancer and 95% confidence interval (CI), adjusted for body mass index and other potential confounders. We evaluated the relationship among all women and stratified by menopausal status.

RESULTS

Our analysis included 66,028 women with 599 incident cases of invasive endometrial adenocarcinoma diagnosed between 1982 and 2004. Although no association was observed overall, the association varied by menopausal status (P interaction=0.02) and a positive association was observed among postmenopausal women; ever use of talcum powder was associated with a 21% increase in risk of endometrial cancer (95% CI, 1.02-1.44), whereas regular use (at least once a week) was associated with a 24% increase in risk (95% CI, 1.03-1.48). In addition, we observed a borderline increase in risk with increasing frequency of use (P trend=0.04).

CONCLUSIONS

Our results suggest that perineal talcum powder use increases the risk of endometrial cancer, particularly among postmenopausal women.

IMPACT

Future and larger studies are needed to confirm this association and investigate potential mechanisms.

Comparative effects of estradiol, methyl-piperidino-pyrazole, raloxifene, and ICI 182 780 on gene expression in the murine uterus

Selective estrogen receptor modulators (SERMs) are potentially useful in treating various endometrial disorders, including endometrial cancer, as they block some of the detrimental effects of estrogen. It remains unclear whether each SERM regulates a unique subset of genes and, if so, whether the combination of a SERM and 17beta-estradiol has an additive or synergistic effect on gene expression. We performed microarray analysis with Affymetrix Mouse Genome 430 2.0 short oligomer arrays to determine gene expression changes in uteri of ovariectomized mice treated with estradiol (low and high dose), methyl-piperidino-pyrazole (MPP), ICI 182 780, raloxifene, and combinations of high dose of estradiol with one of the SERM and dimethyl sulfoxide (DMSO) vehicle control. The nine treatments clustered into two groups, with MPP, raloxifene, and high dose of estradiol in one, and low dose of estradiol, ICI + estradiol, ICI, MPP + estradiol, and raloxifene + estradiol in the second group. Surprisingly, combining a high dose of estradiol with a SERM markedly increased (P<0.02) the number of regulated genes compared with each individual treatment. Analysis of expression for selected genes in uteri of estradiol and SERM-treated mice by quantitative (Q)RT-PCR generally supported the microarray results. For some cancer-associated genes, including Klk1, Ihh, Cdc45l, and Cdca8, administration of MPP or raloxifene with estradiol resulted in greater expression than estradiol alone (P<0.05). By contrast, ICI 182 780 suppressed more genes governing DNA replication compared with MPP and raloxifene treatments. Therefore, ICI 182 780 might be superior to MPP and raloxifene to treat estrogen-induced endometrial cancer in women.

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.

Immunohistochemical markers in endometrial hyperplasia: is there a panel with promise? A review

OBJECTIVE

Despite advances in defining the biology of endometrial carcinomas, there has been little progress in determining markers that distinguish preinvasive endometrial proliferations. The goal of this literature review was to identify studies on endometrial hyperplasia (EH) that describe markers with potential to predict response to progestin therapy or potential for progression to invasive disease.

METHODS

Articles published between January 2000 and October 2006 were identified using the key words endometrial hyperplasia and progesterone receptor or estrogen receptor or biologic marker or immunohistochemistry/immunohistochemical. Articles that reported immunohistochemical studies on specimens of human EH +/-endometrioid endometrial carcinoma with a normal comparison group were included. Only those who reported hyperplasia with atypia separately from nonatypical hyperplasia and with a sample size greater than 10 specimens for the sum of complex and atypical samples were included.

RESULTS

A total of 289 abstracts were reviewed and 150 articles potentially met inclusion criteria. Of these, 123 described immunohistochemical studies on human EH specimens. Only 46 met all criteria for analysis of 61 different markers.

CONCLUSIONS

PTEN seems to have the greatest potential for diagnostic utility in EH, perhaps in combination with Bcl-2 and Bax. However, more uniform and rigorous studies are required to confirm these and additional markers' utility diagnostically in a diagnostic panel. As a major clinical priority is to determine which lesions can be treated medically and which require surgical intervention, focusing future studies on markers that distinguish response to hormone therapy or are involved in hormone regulation, will be important future considerations.

[MUC1 (EMA): A key molecule of carcinogenesis?]

MUC1 is a large trans-membrane highly glycosylated mucin which is expressed at the apical pole of normal cells in glandular epithelia. MUC1 is implicated in many physiological mechanisms such as adhesion, development and differentiation. Also, MUC1 is frequently deregulated and over-expressed with a membrane circumferential and/or cytoplasmic expression. The intracellular tail of MUC1 is phosphorylated and can interact with many signalling proteins and transcriptional factors. Indeed, MUC1 can interact with B-catenin competitively for E-cadherin, thus destabilizing intercellular junctions and favouring metastatic dissemination. In carcinomas, the overexpression and membrane delocalization of MUC1 is associated with a worse prognosis and a shorter survival in breast, colon, kidney, prostate or gastro-intestinal cancers. MUC1 appears to be a novel therapeutic target for immunotherapy or anti-tumour vaccines.

Mucin Genes (MUC2, MUC4, MUC5AC, and MUC6) Detection in Normal and Pathological Endometrial Tissues

Changes in the composition and physical properties of the mucous gel covering the endometrial surface are detected during the menstrual cycle and in pathological conditions. The aim of this study is to analyze the expression patterns of the 11p15 secreted mucins, MUC2, MUC5AC, and MUC6, and the membrane-bound mucin MUC4 in proliferative and secretory normal endometrium, simple and complex hyperplasia, and endometrial adenocarcinoma. A total of 98 samples, 19 of normal endometrium (11 proliferative and 8 secretor), 44 of endometrial hyperplasia (23 simple, 21 complex), and 35 of endometrial endometrioid adenocarcinomas were analyzed by immunohistochemical techniques using specific antimucin antibodies. In the endometrial proliferative glandular epithelium, only MUC4 is detected (36.3% cases). During the secretory phase, increased levels of MUC2 are found (37.5%), whereas MUC4 is less detected (12.5%). In simple hyperplasia, higher levels of mucins are expressed in the endometrial glands: MUC2 is detected in 8.7%, MUC4 in 43.4%, and MUC5AC and MUC6 in 13% of the samples, whereas in complex hyperplasia, decreased levels of mucin expression are found: MUC2 and MUC5AC are not detected, and MUC4 (28.5%) and MUC6 (20.4%) are positive. In endometrial adenocarcinoma, MUC4 is highly detected (77.1%) and increased levels of MUC5AC and MUC6 are found (61.7% and 48.5%), whereas MUC2 is poorly detected (8.5%). These findings suggest that during endometrial neoplasic transformation, increased levels of MUC4, MUC5AC, and MUC6 are detected, whereas MUC2 is only significantly detected in the secretory endometrium.

The effects of sex steroid hormones and interleukin-1-beta on MUC1 expression in endometrial epithelial cell lines

Oestrogen, progesterone and paracrine signals from the embryo have been associated with the overall control of implantation. Changes in the expression of the heavily glycosylated transmembrane glycoprotein MUC1 mucin on the endometrial epithelium are also thought to be important for embryo attachment. Increased MUC1 expression has been correlated with elevated progesterone levels in the secretory phase of the menstrual cycle. Embryonic control of endometrial receptivity through changes in MUC1 expression could be achieved through the interleukin-1 system. Four endometrial epithelial cell lines (HEC1A, HEC1B, Ishikawa and RL592) were treated with oestrogen and progesterone (with or without interleukin-1-beta) and were subjected to immunocytochemistry and flow cytometric analysis to determine MUC1 production using MUC1 antibodies. HEC1A (oestrogen receptor (ER) and progesterone receptor (PR) positive) and HEC1B (ER positive and PR negative) were transfected with the MUC1 promoter, underwent similar treatment regimes and the activity of the MUC1 promoter relative to their untreated controls was determined using a chloramphenicol acetyltransferase (CAT) enzyme-linked immunoassay. Using the cell lines, we determined that endometrial MUC1 expression is up-regulated by progesterone, consistent with the in vivo increases in MUC1 related to high progesterone levels. We also revealed that neither oestrogen, nor interleukin-1-beta, appear to modulate MUC1. Progesterone-dependent regulation of MUC1 is likely to be an important factor in determining endometrial receptivity.

Hypoxia-inducible factor-1alpha expression in human endometrium and its regulation by prostaglandin E-series prostanoid receptor 2 (EP2)

The menstrual cycle is a complex interaction of sex steroids, prostanoids, and cytokines that lead to coordinated tissue degradation, regeneration and repair. The transcription factor hypoxia-inducible factor (HIF-1) plays critical roles in cellular responses to hypoxia, the generation of an inflammatory response and vasculogenesis through transcriptional activation of angiogenic genes. We hypothesize that HIF-1 is expressed in human endometrium and that locally synthesized prostaglandins (PGE2 and PGF(2alpha)) regulate HIF-1 activity. Here we demonstrate that PGE2 up-regulates HIF-1alpha mRNA and protein via the E-series prostanoid receptor 2 (EP2), and this up-regulation is dependent on epidermal growth factor receptor kinase activity. We show the tight temporal-spatial confinement of HIF-1alpha protein expression in endometrium across the cycle. HIF-1alpha is expressed exclusively during the secretory and menstrual phases. Protein expression is maximal at progesterone withdrawal during the late secretory and menstrual phase. HIF-1alpha protein colocalizes with prostaglandin EP2 receptor in glandular cells. In contrast, HIF-1beta/aryl receptor nuclear translocator 1 expression occurs throughout the cycle but is maximal in glandular cells during the proliferative phase. This provides evidence for a role for HIF-1 in the menstrual cycle and demonstrates that HIF-1 activation in human endometrium may occur via a PGE2-regulated pathway and provides a coordinated pathway from progesterone withdrawal through to angiogenic gene expression via HIF-1.

Inclusion of MUC1 (Ma695) in a panel of immunohistochemical markers is useful for distinguishing between endocervical and endometrial mucinous adenocarcinoma

BACKGROUND

Distinguishing endocervical adenocarcinoma (ECA) from endometrial mucinous adenocarcinoma (EMMA) is clinically significant in view of the differences in their management and prognosis. In this study, we used a panel of tumor markers to determine their ability to distinguish between primary endocervical adenocarcinoma and primary endometrial mucinous adenocarcinoma.

METHODS

Immunohistochemistry using monoclonal antibodies to MUC1 (Ma695), p16, estrogen receptor (ER), progesterone receptor (PR), and vimentin, was performed to examine 32 cases, including 18 EMMAs and 14 ECAs. For MUC1, cases were scored based on the percentage of staining pattern, apical, apical and cytoplasmic (A/C), or negative. For p16, cases were scored based on the percentage of cells stained. For the rest of the antibodies, semiquantitative scoring system was carried out.

RESULTS

For MUC1, majority of EMMA (14 of 18 cases, 78%) showed A/C staining, whereas only few ECA (2 of 14, 14%) were positive. The difference of MUC1 expression in the two groups of malignancy was statistically significant (p < 0.001). Staining for p16 was positive in 10 of 14 (71%) ECA and 4 of 18 (22%) EMMA. Estrogen receptor was positive in 3 of 14 (21%) ECA and 17 of 18 (94%) EMMA. Progesterone receptor was positive in 3 of 14 (21%) ECA and 16 of 18 (89%) EMMA. Vimentin was positive in 1 of 14 (7%) ECA, and 9 of 18 (50%) EMA, with median and range of 0 (0-6), and 1.5 (0-9) respectively.

CONCLUSION

A panel of immunohistochemical markers including MUC1, p16, ER, PR, and vimentin is recommended, when there is morphological and clinical doubt as to the primary site of endocervical or endometrial origin.

Conditions associated with antibodies against the tumor-associated antigen MUC1 and their relationship to risk for ovarian cancer

Many cancers, including ovarian, overexpress epithelial mucin (MUC1) and promote anti-MUC1 antibodies that may correlate with more favorable prognosis. By extension, risk for ovarian cancer might be reduced by preexisting MUC1-specific immunity. We measured anti-MUC1 antibodies in 705 control women, identified events predicting antibodies, and estimated ovarian cancer risk by comparing profiles of events generating antibodies in controls with those in 668 ovarian cancer cases. Factors predicting antibodies included oral contraceptive use, breast mastitis, bone fracture or osteoporosis, pelvic surgeries, nonuse of talc in genital hygiene, and to a lesser extent intrauterine device use and current smoking. There was a significant increase in the likelihood of having anti-MUC1 antibodies from 24.2% in women with 0 or 1 condition, to 51.4% in those with five or more conditions. By the same index of events, the risk for ovarian cancer was inversely associated with number of conditions predisposing to anti-MUC1 antibodies. Compared with having experienced 0 or 1 event, the adjusted risk for ovarian cancer decreased progressively with relative risks (and 95% confidence limits) of 0.69 (0.52-0.92), 0.64 (0.47-0.88), 0.49 (0.34-0.72), and 0.31 (0.16-0.61), respectively for women with two, three, four, and five or more events related to the presence of antibodies (P(trend) < 0.0001.) We conclude that several traditional and new risk factors for ovarian cancer may be explained by their ability to induce MUC1 immunity through exposure of MUC1 to immune recognition in the context of inflammatory or hormonal processes in various MUC1-positive tissues.

Glycodelin reduces carcinoma-associated gene expression in endometrial adenocarcinoma cells

OBJECTIVE

Glycodelin is a major secretory glycoprotein of differentiated endometrial epithelium, rarely expressed in proliferative endometrium or endometrial cancer. We aimed to elucidate its role in growth and gene expression of endometrial adenocarcinoma cells, and hypothesized that glycodelin affects cell growth and tumor-associated gene expression.

STUDY DESIGN

Endometrial adenocarcinoma HEC-1B cells were transfected with glycodelin cDNA in both antisense and sense orientations. Cellular morphology, cell proliferation, and gene expression were compared between native and transfected cells.

RESULTS

Compared with native and antisense-transfected carcinoma cells, sense-transfected, glycodelin-producing carcinoma cells showed reduced proliferation, morphologic changes, and altered expression of cancer-related genes. Notably, anti-apoptotic Bcl-XL and MUC1 genes were down-regulated.

CONCLUSION

Reduction by glycodelin transfection of carcinoma cell proliferation and expression of MUC1 and Bcl-XL is significant because these genes are often overexpressed in human cancers--MUC1 is linked to invasive growth and metastases, and both confer resistance to chemotherapy. These results suggest a novel mechanism whereby malignant growth of endometrial adenocarcinoma cells is regulated.

Real-time quantitative RT-PCR detection of disseminated endometrial tumor cells in peripheral blood and lymph nodes using the LightCycler System

OBJECTIVE

Some endometrial cancer patients without clinical evidence of extrauterine spread die as a result of recurrence even after curative operation. These recurrences may arise from occult tumor cells that are not detected by conventional methods. The goal of this study was to develop a quantitative method for the detection of disseminated tumor cells (DTCs) in the peripheral blood (PB) and lymph nodes (LNs) of patients with endometrial cancer.

METHODS

Ninety-eight PB samples from 30 patients and 218 LNs from 14 patients were studied. Real-time quantitative analysis was performed using a LightCycler instrument and a TaqMan probe for cytokeratin 19 (CK19) as a marker gene.

RESULTS

This method resulted in the reproducible quantitation of 10 to 10(6) MCF-7 cells (CK19-expressing breast cancer cell line) per 10(6) peripheral blood nucleated cells. CK19 mRNA expression was detected in 28 PB samples and in 62 LNs. Only three preoperative PB samples and one postoperative PB sample (from four patients) and 33 LNs (from six patients) were PCR-positive. The PCR-positive rate of LNs was higher in patients with pathologically metastatic (path-positive) LNs than in patients with path-negative but PCR-positive LNs. Furthermore, the CK19 mRNA background expression rate was higher in the LNs of path-negative but PCR-positive patients than in LNs of path-negative and PCR-negative patients.

CONCLUSIONS

Real-time qRT-PCR with TaqMan probes is a sensitive, specific and rapid method for the detection of DTCs in PB and LNs. Additional studies with larger numbers of patients and adequate follow-up would be of benefit.

MUC1, MUC2, MUC4, and MUC5AC expression in salivary gland mucoepidermoid carcinoma: diagnostic and prognostic implications

We determined whether immunostaining for mucins could provide a better characterization of salivary gland mucoepidermoid carcinoma (MEC). We investigated 63 MECs by immunohistochemistry for MUC1, MUC2, MUC4, and MUC5AC. Mucin expressing cell types and labeling patterns were recorded. The results were compared with microscopic grade, tumor-associated lymphoid infiltrate, mucin expression in surrounding salivary glands, clinical features, and outcome. MUC1 and MUC4 labeled the apical membrane of glandular tumor cells and the entire membrane of intermediate, clear, and epidermoid tumor cells. MUC2 and MUC5AC were expressed in the cytoplasm of glandular, mucous, and intermediate tumor cells. In contrast to MUC1, MUC4 expression decreased with tumor grade (P < 0.01). Unlike MUC2, MUC5AC was expressed in more than 50% of high-grade tumors, including 2 cases that were not stained with Alcian blue. MUC1 and MUC5AC were associated with tumor-associated lymphoid infiltrates (P < 0.05), but not with tumor-associated lymphoid follicles. The proportions of tumors expressing mucins were 71% for MUC1, 21% for MUC2, 79% for MUC4, and 68% for MUC5AC. MUC1 and MUC5AC were more frequently expressed in tumors than in surrounding glands (P < 0.0001). MUC1 expression correlated with shorter progression-free survival (P < 0.05). In conclusion, mucin expression in MEC differs from that in salivary glands. Intermediate cells express MUC1 and MUC4 all along their cell surface and MUC2 and MUC5AC in their cytoplasm. Staining for MUC5AC in high-grade tumors can be helpful for distinguishing high-grade MEC from squamous cell carcinoma. While MUC4 is related to tumor differentiation, MUC1 expression indicates a worse prognosis.

Hath1, down-regulated in colon adenocarcinomas, inhibits proliferation and tumorigenesis of colon cancer cells

A striking feature of colon tumors is the significant reduction of goblet cells. Although targeted deletion of Math1 in mice leads to a loss of intestinal secretory cells, including goblet cells, the role of Hath1 in colon tumorigenesis remains unknown. Here we report that Hath1, the human ortholog of Math1, was dramatically down-regulated in colon tumor samples and colon cancer cell lines. Overexpression of Hath1 in HT29, an aggressive colon cancer cell line, resulted in a significant inhibition on cell proliferation, anchorage-independent growth in soft agar and, more importantly, growth of human colon cancer cell xenografts in athymic nude mice. Such inhibition was accompanied by altered expression of a goblet cell differentiation marker, MUC2, and cell cycle regulators cyclin D1 and p27kip1. Hath1 expression also was up-regulated on inhibition of the Wnt pathway, which has been well implicated in colon tumorigenesis. Hence, this study suggests that Hath1 may be a novel factor downstream of the Wnt pathway capable of suppressing anchorage-independent growth of colon cancer cell lines. More importantly, this study is the first to establish a link between down-regulation of Hath1 expression and colon tumorigenesis.

MUC1 and MUC2 in pancreatic neoplasia

MUCs are glycoproteins with various roles in homeostasis and carcinogenesis. Among other actions, MUC1 may inhibit cell-cell and cell-stroma interactions and function as a signal transducer, participating in cancer progression. In contrast, MUC2 is normally found only in goblet cells, where it contributes to the protective barrier function of these cells. Recently, a tumour suppressor role has been demonstrated for MUC2, and both MUC1 and MUC2 appear to have important roles in pancreatic neoplasia. MUC1 appears to be a marker of aggressive phenotype and may facilitate the vascular spread of carcinoma cells. In contrast, MUC2 is rarely detectable in aggressive pancreatic tumours, but is commonly expressed in intraductal papillary mucinous neoplasms (IPMNs), which are rare, indolent tumours, in intestinal IPMNs, and in indolent colloid carcinomas. MUC2 appears to be not only a marker of this indolent pathway, but also partly responsible for its less aggressive nature. Thus, in pancreatic neoplasia, MUC1 and MUC2 have potential diagnostic and prognostic value as markers of aggressive and indolent phenotypes, respectively, and have potential as therapeutic targets.

Expression of MUC1 (EMA) and E-cadherin in renal cell carcinoma: a systematic immunohistochemical analysis of 188 cases

MUC1 (epithelial membrane antigen) is a membrane-associated mucin known to interfere with both cell-cell and cell-matrix adhesions. Overexpression has been associated with poor prognosis in a variety of cancers. We investigated the expression of MUC1 (using two different antibodies, MA695 and E29) and E-cadherin in renal cell carcinomas (137 conventional, 23 chromophobe, 20 papillary, and eight unclassified tumors) with respect to diagnostic and prognostic significance using a tissue microarray technique. Immunoreactivity was correlated with histological subtype, pT-stage, and grade using the chi2 test or the Fisher's exact test, respectively. Impact on disease-free survival was analyzed using the Kaplan-Meier method and the log-rank test. Immunoreactivity of more than 10% of cancer cells with MA695, E 29, and E-cadherin antibodies was found in 112/133 (84%), 86/133 (65%), and 7/131 (5%) conventional, 20/22 (91%), 19/22 (86%), and 21/22 (95%) chromophobe, 13/20 (65%), 8/20 (40%), and 3/20 (15%) papillary as well as 5/8 (63%), 5/8 (63%), and 4/8 (50%) unclassified carcinomas, respectively. The two different MUC1 antibodies yielded comparable staining results. A diffuse cytoplasmic staining pattern for MUC1 was found exclusively in chromophobe carcinomas, whereas conventional and papillary subtypes showed predominantly membranous staining (P<0.0001). Regarding papillary carcinomas, MUC1 was predominantly associated with type 1 (P=0.0001), and E-cadherin with type 2 (P=0.049) tumors. The cellular staining pattern of MUC1 in conventional tumors was related to pT-stage (P=0.002) and tumor grade (P=0.001): Low-stage (pT1/pT2) and grade (G1/G2) tumors showed a predominantly apical membranous staining, high-stage (pT3a/pT3b) and grade (G3/G4) tumors a predominantly circumferential membranous staining (with or without additional diffuse cytoplasmic immunoreactivity), which, in the conventional subtype, was associated with poor prognosis (P<0.0001). In conclusion, MUC1 and E-cadherin are diagnostically and prognostically useful markers in renal tumor pathology, especially when cellular staining patterns are considered.

Association of hypoxia-inducible factors 1alpha and 2alpha with activated angiogenic pathways and prognosis in patients with endometrial carcinoma

BACKGROUND

Hypoxia-inducible factor 1alpha (HIF-1alpha) and HIF-2alpha are essential regulatory proteins for the adaptation of tumor cells to hypoxia, and they stimulate angiogenesis through activation of the vascular endothelial growth factor (VEGF) gene.

METHODS

HIF-1alpha and HIF-2alpha proteins were studied immunohistochemically in a group of 81 patients with Stage I endometrial adenocarcinoma of the endometrioid cell type. The results were correlated with intratumoral angiogenesis, the expression of the angiogenic factors VEGF and thymidine phosphorylase (TP), and the VEGF/receptor (VEGF/KDR) complex. Relations also were sought with estrogen receptor (ER) and progesterone receptor (PR), with the apoptosis-related proteins bcl-2 and p53, with several histopathologic parameters, and with patient prognosis. In addition, a sample of 25 normal endometria at various phases of the menstrual cycle was studied for the presence of HIF-1alpha and HIF-2alpha.

RESULTS

HIF-1alpha expression was detected in 49% of endometrial carcinomas. The expression was cytoplasmic or mixed nuclear/cytoplasmic. HIF-1alpha expression was associated with up-regulation of the VEGF pathway and with increased standard microvessel density (sMVD) and activated VEGF/KDR microvessel density (aMVD). It also was associated with a poor prognosis in both univariate and multivariate analyses. HIF-2alpha protein showed a pattern of expression similar to the pattern seen in HIF-1alpha, but expression of HIF-2alpha protein occurred in only 17% of endometrial carcinomas, and it was associated with increased TP reactivity. There also was a relation of HIF-1alpha expression with well-differentiated endometrial neoplasms, and there was a marginal association of HIF-1alpha and HIF-2alpha with ER expression. With reference to normally cycling tissues, HIF-1alpha nuclear/cytoplasmic expression was particularly strong in the samples of early proliferative phase endometrium compared with HIF-2alpha protein expression, which showed a constant reaction throughout the menstrual cycle.

CONCLUSIONS

The up-regulation of HIF-1alpha and, to a lesser extent, of HIF-2alpha is a common event in Stage I endometrial adenocarcinomas. In these tumors, HIF-1alpha expression is related to increased angiogenesis, through activation of the VEGF angiogenic pathway, and to an unfavorable prognosis. HIF-2alpha accumulation is associated with increased expression of the angiogenic factor TP.