Overexpression of CD44 variant 6 in human endometrial cancer and its prognostic significance

Potential biomarkers in endometrial cancer: a narrative review

CONTEXT

Every year, approximately 0.4 million women suffer from endometrial cancer (EC) worldwide and it has become the most common gynecological malignancy. Almost 66% of EC cases are diagnosed at an early stage and can be cured by performing surgery while those at an advanced stage turns out to be fatal. Biomarkers of endometrial cancer would be very valuable for screening of women who are at high risk and in detecting the chance of recurrence of disease.

OBJECTIVE

The current article has reviewed studies published on expression of biomarkers and susceptibility to EC.

METHODS

Google Scholar and PubMed were used as searching platforms and we have majorly considered the literature from last 10 years.

RESULTS

Potential biomarkers of EC identified from various studies were summarised.

Cell adhesion molecules in endometrial cancer - A systematic review

Adhesive molecules are responsible for the cell-cell interaction and the surrounding intercellular environment creating normal tissue architecture. The role of adhesion proteins in cancer refers to angiogenesis, loss of tissue continuity, and deprivation of intercellular contact with the extracellular matrix, promoting the spread of cancer through the formation of metastases. The integrity of the epithelium is disturbed - with disturbances in the whole mechanism of cell connections, thanks to which cancer cells infiltrate surrounding tissues, and move to lymphatic and blood vessels. Adhesive molecules are divided into five main families: cadherin, catenins, integrins, the immunoglobulin superfamily and non-classical adhesion molecules. In the present review we describe the role of all five families of adhesive molecules in endometrial cancer.

Unsupervised Clustering of Immunohistochemical Markers to Define High-Risk Endometrial Cancer

Considerable heterogeneity exists in outcomes of early endometrial cancer (EC) according to the type but also the histological grading. Our goal was to describe the immunohistochemical profiles of type I EC according to grades and type II EC, to identify groups of interacting proteins using principal component analysis (PCA) and unsupervised clustering. We studied 13 immunohistochemical markers (steroid receptors, pro/anti-apoptotic proteins, metalloproteinases (MMP) and tissue inhibitor of metalloproteinase (TIMP), and CD44 isoforms known for their role in endometrial pathology. Co-expressed proteins associated with the type, grade and outcome of EC were determined by PCA and unsupervised clustering. PCA identified three functional groups of proteins from 43 tissue samples (38 type I and 5 type II EC): the first was characterized by p53 expression; the second by MMPs, bcl-2, PR B and CD44v6; and the third by ER alpha, PR A, TIMP-2 and CD44v3. Unsupervised clustering found two main clusters of proteins, with both type I grade 3 and type II EC exhibiting the same cluster profile. PCA and unsupervised clustering of immunohistochemical markers in EC contribute to a better comprehension and classification of the disease.

EMP2 is a novel therapeutic target for endometrial cancer stem cells

Previous studies have suggested that overexpression of the oncogenic protein epithelial membrane protein-2 (EMP2) correlates with endometrial carcinoma progression and ultimately poor survival from disease. To understand the role of EMP2 in the etiology of disease, gene analysis was performed to show transcripts that are reciprocally regulated by EMP2 levels. In particular, EMP2 expression correlates with and helps regulate the expression of several cancer stem cell associated markers including aldehyde dehydrogenase 1 (ALDH1). ALDH expression significantly promotes tumor initiation and correlates with the levels of EMP2 expression in both patient samples and tumor cell lines. As therapy against cancer stem cells in endometrial cancer is lacking, the ability of anti-EMP2 IgG1 therapy to reduce primary and secondary tumor formation using xenograft HEC1A models was determined. Anti-EMP2 IgG1 reduced the expression and activity of ALDH and correspondingly reduced both primary and secondary tumor load. Our results collectively suggest that anti-EMP2 therapy may be a novel method of reducing endometrial cancer stem cells.

Impact of structurally modifying hyaluronic acid on CD44 interaction

CD44 is a widely-distributed type I transmembrane glycoprotein that binds hyaluronic acid (HA) in most cell types, including primary tumor cells and cancer-initiating cells and has roles in cell migration, cell-cell, and cell-matrix adhesion. HA-derived conjugates and nanoparticles that target the CD44 receptor on cells have been reported for targeted delivery of therapeutics and imaging agents. Altering crucial interactions of HA with CD44 active sites holds significant importance in modulating targeting ability of hyaluronic acid to other cancer types that do not express the CD44 receptor or minimizing the interaction with CD44+ cells that are not target cells. The approach adopted here was deacetylation of the N-acetyl group and selective sulfation on the C6-OH on the HA polymer, which form critical interactions with the CD44 active site. Major interactions identified by molecular modeling were confirmed to be hydrogen bonding of the C6-OH with Tyr109 and hydrophobic interaction of the N-acetyl group with Tyr46, 83 and Ile 92. Modified HA was synthesized and characterized and its interactions were assessed by in vitro and molecular modeling approaches. In vitro techniques included flow cytometry and fluorescence polarization, while in silico approaches included docking and binding calculations by a MM-PBSA approach. These studies indicated that while both deacetylation and sulfation of HA individually decrease CD44 interaction, both chemical modifications are required to minimize interaction with CD44+ cells. The results of this study represent the first step to effective retargeting of HA-derived NPs for imaging and drug delivery.

E-Cadherin, CD44v6, and Insulin-Like Growth Factor-II mRNA-Binding Protein 3 Expressions in Different Stages of Hydatidiform Moles

E-cadherin, CD44v6, and IMP3 expression in partial, complete, and invasive hydatidiform moles (HMs) was evaluated. High E-cadherin expression with low CD44v6 expression was observed in partial, complete, and invasive HMs, as well as in normal placental tissues; and there was no significant difference in E-cadherin and CD44v6 expression among the four groups. However, IMP3 expression was gradually decreased in the order of normal placental tissues, partial HMs, complete HMs, and invasive HMs; wherein, invasive HMs had the lowest level. Low IMP3 expression may serve as a prognostic biomarker for HMs, and IMP3 may play a certain role in HMs progression.

Immunohistochemical expression of cancer stem cell related markers CD44 and CD133 in endometrial cancer

The goal of this study was to detect the presence of cancer stem cell markers CD44 and CD133 in immunohistochemically stained samples of endometrial cancer and correlate their expression with clinicopathological variables to identify the impact of CD44 or CD133 expression on tumor behavior and endometrial carcinogenesis. Marker expression was analyzed in 62 endometrial cancer samples (57 endometrioid carcinoma and 5 carcinosarcoma) and 15 proliferative endometrium samples. We detected CD133 and CD44 expression in 87.09% and 79.03% respectively of the studied endometrial cancers, and the expression was significantly different from the normal group. CD44 expression decreased with myometrial invasive depth and lymph-vascular space invasion (LVSI), and these inverse relationships were significant (p=0.034, p=0.019, respectively). CD133 was more expressed by early stage tumor (FIGO I-II) compared with those having FIGO III to IV stage disease (p=0.021). The most notable conclusion of the present study is that CD44 and CD133 might participate in early-stage endometrial cancer carcinogenesis, and their overexpression may facilitate the early diagnosis of endometrial cancers. Analysis of our results supports the hypothesis that CD44 expression tends to decrease as the disease becomes invasive and progressive. So, we concluded that CD44 down-regulation might warn of a more aggressive course and may have a link with poorly prognosis carcinosarcomas. Further examination of the expression and function of CD44 and CD133 with a greater number of carcinosarcomas is warranted.

Advances and advantages of nanomedicine in the pharmacological targeting of hyaluronan-CD44 interactions and signaling in cancer

Extensive experimental evidence in cell and animal tumor models show that hyaluronan-CD44 interactions are crucial in both malignancy and resistance to cancer therapy. Because of the intimate relationship between the hyaluronan-CD44 system and tumor cell survival and growth, it is an increasingly investigated area for applications to anticancer chemotherapeutics. Interference with the hyaluronan-CD44 interaction by targeting drugs to CD44, targeting drugs to the hyaluronan matrix, or interfering with hyaluronan matrix/tumor cell-associated CD44 interactions is a viable strategy for cancer treatment. Many of these methods can decrease tumor burden in animal models but have yet to show significant clinical utility. Recent advances in nanomedicine have offered new valuable tools for cancer detection, prevention, and treatment. The enhanced permeability and retention effect has served as key rationale for using nanoparticles to treat solid tumors. However, the targeted and uniform delivery of these particles to all regions of tumors in sufficient quantities requires optimization. An ideal nanocarrier should be equipped with selective ligands that are highly or exclusively expressed on target cells and thus endow the carriers with specific targeting capabilities. In this review, we describe how the hyaluronan-CD44 system may provide such an alternative in tumors expressing specific CD44 variants.

CD44 expression in curettage and postoperative specimens of endometrial cancer

BACKGROUND

Adhesive molecules like CD44 are well defined key players in the metastatic cascade in many cancers, including endometrial cancer. They could play a role of markers of invasion, metastasis and prognostic factors.

AIM OF THE STUDY

The aim of the study is to assess a possible role of the CD44 as a marker of invasion in endometrial cancer, both at the moment of preoperative workup and final staging.

MATERIALS AND METHODS

Available for analysis were archival specimens of 51 patients who had underwent curettage and surgery between 2002 and 2007. An immunohistochemical study for CD44 expression was performed in curettage and postoperative specimens. Normal endometrium of 20 randomly chosen patients was used as a control group.

RESULTS

In endometrial cancer the expression of CD44 was significantly more intensive than in normal endometrium. In postoperative specimens, the CD44 expression was weaker in serous than in endometrioid cancer. There was no significant correlation between the adhesion molecule expression and clinicopathological features: grade,depth of invasion, cervical involvement, serosal and adnexal involvement, lymph-vascular space involvement, lymph node and distant metastases nor FIGO stage.

CONCLUSIONS

An increased expression of CD44 in endometrial cancer suggests its possible role in pathogenesis of this disease, however, it doesn't seem to be crucial. Different expression of the CD44 in endometrioid and papillary-serous type may reflect different pathogenesis of these types of cancer. No statistically proved relation between the investigated molecule expression and clinicopathological parameters suggests scepticism about its use in diagnostic process of endometrial cancer.

Metastasis review: from bench to bedside

Cancer is the final result of uninhibited cell growth that involves an enormous group of associated diseases. One major aspect of cancer is when cells attack adjacent components of the body and spread to other organs, named metastasis, which is the major cause of cancer-related mortality. In developing this process, metastatic cells must successfully negotiate a series of complex steps, including dissociation, invasion, intravasation, extravasation, and dormancy regulated by various signaling pathways. In this review, we will focus on the recent studies and collect a comprehensive encyclopedia in molecular basis of metastasis, and then we will discuss some new potential therapeutics which target the metastasis pathways. Understanding the new aspects on molecular mechanisms and signaling pathways controlling tumor cell metastasis is critical for the development of therapeutic strategies for cancer patients that would be valuable for researchers in both fields of molecular and clinical oncology.

CD44 variant 6 is associated with prostate cancer metastasis and chemo-/radioresistance

INTRODUCTION

Prostate cancer (CaP) is the second leading malignancy in older men in Western countries. The role of CD44 variant 6 (CD44v6) in CaP progression and therapeutic resistance is still uncertain. Here, we investigated the roles of CD44v6 in CaP metastasis and chemo/radioresistance. Expression of CD44v6 in metastatic CaP cell lines, human primary CaP tissues and lymph node metastases was assessed using immunofluorescence and immunohistochemistry, respectively.

METHODS

Knock down (KD) of CD44v6 was performed in PC-3M, DU145, and LNCaP cells using small interfering RNA (siRNA), and confirmed by confocal microscope, Western blot and quantitative real time polymerase chain reaction (qRT-PCR). Cell growth was evaluated by proliferation and colony formation assays. The adhesive ability and invasive potential were assessed using a hyaluronic acid (HA) adhesion and a matrigel chamber assay, respectively. Tumorigenesis potential and chemo-/radiosensitivity were measured by a sphere formation assay and a colony assay, respectively.

RESULTS

Over-expression of CD44v6 was found in primary CaP tissues and lymph node metastases including cancer cells and surrounding stromal cells. KD of CD44v6 suppressed CaP proliferative, invasive and adhesive abilities, reduced sphere formation, enhanced chemo-/radiosensitivity, and down-regulated epithelial-mesenchymal transition (EMT), PI3K/Akt/mTOR, and Wnt/β-catenin signaling pathway proteins in vitro.

CONCLUSIONS

Our findings demonstrate that CD44v6 is an important cancer stem cell-like marker associated with CaP proliferation, invasion, adhesion, metastasis, chemo-/radioresistance, and the induction of EMT as well as the activation PI3K/Akt/mTOR and Wnt signaling pathways, suggesting that CD44v6 is a novel therapeutic target to sensitize CaP cells to chemo/radiotherapy.

Methylation analysis of tumor suppressor genes in endometroid carcinoma of endometrium using MS-MLPA

BACKGROUND

Epigenetic changes are considered to be a frequent event during tumor development. Hypermethylation of promoter CpG islands represents an alternative mechanism for inactivation of tumor suppressor genes, DNA repair genes, cell cycle regulators and transcription factors. The aim of this study was to investigate promoter methylation of specific genes in endometrial cancer by comparison with normal endometrial tissue.

MATERIALS AND METHODS

We used MS-MLPA (Methylation-specific Multiplex ligation-dependent probe amplification) to compare the methylation status of 59 tissue samples of endometroid type of endometrial carcinoma with 20 control samples of non-neoplastic endometrium.

RESULTS

Using 15% cut-off for methylation, we observed significantly higher methylation in the CDH13 gene in endometrial cancer group. We observed significantly higher methylation in both WT1 and GATA5 genes in IB stage of endometroid carcinoma. We also observed significantly higher methylation in GATA5 gene in the group of poorly differentiated endometroid carcinoma.

CONCLUSION

The findings suggest the importance of hypermethylation of CDH13, WT1 and GATA5 genes in endometrial carcinogenesis and could have implications for future diagnostic and therapeutic strategies of endometrial cancer based on epigenetic changes.

Clinicopathological significance of fascin and CD44v6 expression in endometrioid carcinoma

Background

Fascin and CD44v6 may have significant roles as biomarkers in tumour progression and metastasis. In endometrioid carcinomas, the fascin expression profile is less defined, and the significance of CD44v6 is uncertain. We aimed to investigate the expressions of both fascin and CD44v6 in endometrioid carcinomas and to evaluate their inter-relation with clinicopathological parameters.

Methods

Fascin and CD44v6 expressions were evaluated, individually and in combination, in a series of 47 endometrioid carcinomas and 10 proliferative endometrium samples. The staining extent and intensity of both markers in tumour cells were scored semiquantitatively. The relationship between immunoexpressions and clinicopathological variables was assessed.

Results

The expression rates of fascin and CD44v6 in endometrioid carcinoma were 72.34% and 46.80%, respectively. Although these expression rates were higher than those in proliferative endometrial samples, fascin expression showed a statistically significant difference from the normal group (p = 0.02), but CD44v6 did not differ (p = 0.54). Fascin expression was significantly correlated with tumour grade (p = 0.003) and neural invasion (p = 0.036) in a univariate analysis. In contrast, no significant correlation was found between CD44v6 and any of the clinicopathological parameters.

Conclusions

Our findings suggest that fascin might be an independent prognostic indicator in the different steps of extracellular matrix invasion. On the other hand, CD44v6 was not a predictive factor in endometrioid cancer.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8511594927206899.

Cadherins, catenins and cell cycle regulators: impact on survival in a Gynecologic Oncology Group phase II endometrial cancer trial

OBJECTIVE

We evaluated the clinical relevance of catenins, cadherins and cell cycle regulators in stage IV or recurrent endometrial carcinoma in a multi-center phase II trial (GOG protocol #119).

METHODS

Tissue microarrays of metastatic or recurrent (n=42) tumor were developed and immunohistochemistry was performed. Average expression (percent staining x intensity) was assessed in tumor epithelium ((E)) and stroma ((S)) and categorized into tertiles (T1, T2, T3) for E-cadherin(E), N-cadherin(E), alpha-catenin(E), beta-catenin(E), gamma-catenin(E), p120-catenin(E) and Ki-67(E); as negative, below median or above median for p16(E), p27(E) and CD44(S); or as negative or positive for p53(E), Ki-67(S) and APC(S) (adenomatous polyposis coli). End points included response and survival.

RESULTS

E-cadherin(E), p16(E), and p53(E) varied by race (p=0.003, p=0.024, p=0.002,) and N-cadherin(E), Ki-67(E), p16(E) and p27(E) by tumor type (p=0.015, p=0.011, p=0.005, p=0.021). Correlations were observed among E-cadherin(E) with p120(E) (r=0.66), p53(E) (r=-0.32), alpha-catenin(E) (r=0.52), beta-catenin(E) (r=0.58), and gamma-catenin(E) (r=0.58). High E-cadherin(E) (T2 or T3) versus low (T1) expression was associated with better survival in unadjusted (hazard ratio [HR]=0.14, 95% confidence interval [CI]=0.06-0.37 or HR=0.17, 95% CI=0.07-0.42) and adjusted models (HR=0.18, 95% CI=0.05-0.59 or HR=0.22, 95% CI=0.07-0.70). High p16(E) versus negative expression was associated with worse survival in unadjusted (HR=3.87, 95% CI=1.74-8.61) and adjusted (HR=4.18, 95% CI=1.28-13.6) models. Positive versus negative expression of p53(E) was associated with worse survival in unadjusted (HR=2.31, 95% CI=1.16-4.60) but not adjusted models.

CONCLUSIONS

E-cadherin(E) and p16(E) appear to be clinically relevant, independent prognostic factors in stage IV or recurrent endometrial cancers treated with Tamoxifen and Medroxyprogesterone acetate, and merit further study.

Hyaluronan-CD44 interactions as potential targets for cancer therapy

It is becoming increasingly clear that signals generated in tumor microenvironments are crucial to tumor cell behavior, such as survival, progression and metastasis. The establishment of these malignant behaviors requires that tumor cells acquire novel adhesion and migration properties to detach from their original sites and to localize to distant organs. CD44, an adhesion/homing molecule, is a major receptor for the glycosaminoglycan hyaluronan, which is one of the major components of the tumor extracellular matrix. CD44, a multistructural and multifunctional molecule, detects changes in extracellular matrix components, and thus is well positioned to provide appropriate responses to changes in the microenvironment, i.e. engagement in cell-cell and cell-extracellular matrix interactions, cell trafficking, lymph node homing and the presentation of growth factors/cytokines/chemokines to co-ordinate signaling events that enable the cell responses that change in the tissue environment. The potential involvement of CD44 variants (CD44v), especially CD44v4-v7 and CD44v6-v9, in tumor progression has been confirmed for many tumor types in numerous clinical studies. The downregulation of the standard CD44 isoform (CD44s) in colon cancer is postulated to result in increased tumorigenicity. CD44v-specific functions could be caused by their higher binding affinity than CD44s for hyaluronan. Alternatively, CD44v-specific functions could be caused by differences in associating molecules, which may bind selectively to the CD44v exon. This minireview summarizes how the interaction between hyaluronan and CD44v can serve as a potential target for cancer therapy, in particular how silencing CD44v can target multiple metastatic tumors.

Delivery of CD44 shRNA/nanoparticles within cancer cells: perturbation of hyaluronan/CD44v6 interactions and reduction in adenoma growth in Apc Min/+ MICE

Our studies have shown that constitutive interactions between hyaluronan and CD44 on tumor cells induces various anti-apoptotic cell survival pathways through the formation of a multimeric signaling complex that contains activated receptor tyrosine kinases. Inhibition of the hyaluronan-CD44 interactions on tumor cells by hyaluronan-CD44 interaction antagonists suppresses these activities by disassembling the complex. Although the anti-tumor activity of hyaluronan-oligosaccharides, a hyaluronan-CD44 interaction antagonist, is effective in sensitizing tumor cells to chemotherapeutic agents and reducing tumor growth in xenografts, hyaluronan-oligosaccharide alone was not effective in reducing tumor progression in Apc Min/+ mice. We now show in vitro and in vivo that targeted inhibition of the expression of CD44v6 depletes the ability of the colon tumor cells to signal through hyaluronan-CD44v6 interactions. First, we cloned oligonucleotides coding CD44v6 shRNA into a conditionally silenced pSico vector. Second, using pSico-CD44v6 shRNA and a colon-specific Fabpl promoter-driven Cre recombinase expression vector packaged into transferrin-coated nanoparticles, we successfully delivered the CD44v6 shRNA within pre-neoplastic and neoplastic colon malignant cells. Third, using the Apc Min/+ mice model, we demonstrated that inhibition of the CD44v6 expression reduces the signaling through a hyaluronan/CD44v6-pErbB2-Cox-2 interaction pathway and reduced adenoma number and growth. Together, these data provide insight into the novel therapeutic strategies of short hairpin RNA/nanoparticle technology and its potential for silencing genes associated with colon tumor cells.

Junctional Adhesion Molecule: An Expression in Human Endometrial Carcinoma

Junctional adhesion molecule A (JAM-A) is involved in cell-cell contact and tight junction formation. Loss of cell adhesion molecules may be associated with high histologic grade and invasiveness of endometrial carcinoma. We attempted to determine JAM-A expression in human endometrial carcinoma and its correlations with pathologic features, stage, and survival. Junctional adhesion molecule A expression in human endometrial carcinoma was evaluated by immunohistochemistry. In addition, we cultured human well and poorly differentiated endometrial adenocarcinoma cell lines, Ishikawa cells, and KLE in 3-dimensional basement membrane preparation, and JAM-A expression in these cells was assessed by real-time reverse transcription-polymerase chain reaction and immunohistochemistry. Junctional adhesion molecule A immunostaining intensity was negatively correlated with histologic grade (τ = −0.420, P < 0.0001), myometrial invasion (τ = −0.306, P < 0.01), and stage (τ = −0.383, P < 0.0001). Low JAM-A immunostaining intensity was associated with positive vascular space involvement (P < 0.01). Moreover, low immunostain intensity was significantly (P < 0.0001) related to low overall survival rate and progression-free survival rate. Additionally, in our 3-dimensional epithelial cell culture, JAM-A expression in poorly differentiated adenocarcinoma was significantly lower than that in well-differentiated adenocarcinoma (P < 0.001). Junctional adhesion molecule A expression seems to be reduced in high-grade or advanced endometrial carcinoma and may be a prognostic factor.

Expression of a novel oncofetal mRNA-binding protein IMP3 in endometrial carcinomas: diagnostic significance and clinicopathologic correlations

Insulin-like growth factor-II mRNA-binding protein 3 (IMP3) is a newly identified oncofetal mRNA-binding protein that is involved in embryogenesis and carcinogenesis of some malignant neoplasms. To investigate the diagnostic and clinicopathologic significance of this protein in endometrial carcinomas, we evaluated immunohistochemical expression of IMP3 in the two most common forms of endometrial malignancies, endometrioid adenocarcinoma and serous carcinoma. We selected 167 endometrial adenocarcinoma cases including 122 cases of endometrioid adenocarcinoma and 45 cases of serous carcinoma. Twenty samples of benign endometrium obtained from 20 patients with nonmalignant uterine lesions were used as controls. Positive immunohistochemical stain for IMP3 was identified in all serous carcinoma cases, among which, 39 (86%) and 3 (7%) cases showed IMP3 immunoreactivity in >50%, and 21-50, or 6-20% of tumor cells, respectively. Immunohistochemical reaction intensity for IMP3 was identified to be strong in 38 (84%) and intermediate in 7 (16%) cases of serous carcinoma. Fifty-four (44%) cases of endometrioid adenocarcinoma were negative for IMP3. Thirty (25%), 20 (16%), 10 (8%), and 8 (7%) cases of endometrioid adenocarcinoma demonstrated positive immunoreactivity for IMP3 in 1-5, 6-20, 21-50, and >50% of the tumor cells. Strong IMP3-staining intensity was noted in 34 (28%), intermediate in 26 (21%), and weak in 8 (7%) cases of endometrioid adenocarcinoma. All 20 control cases were negative for IMP3. To compare p53 with IMP3 expressions, we found that 35 (78%) of the serous carcinoma cases showed strong p53 immunohistochemical activity in >50% of the tumor cell nuclei. In contrast, 11 of 112 (10%) endometrioid adenocarcinoma cases demonstrated strong p53 positivity in >50% of the tumor cell nuclei. In conclusion, our findings demonstrate significant expression of IMP3 in serous carcinoma as compared to endometrioid adenocarcinoma (P<0.0001). Expression of IMP3 and p53 may be helpful biomarkers in the distinction of endometrial serous carcinoma from endometrioid adenocarcinoma. In addition, expression of IMP3 in endometrioid adenocarcinoma correlates with higher nuclear and architecture grades of the tumor (P=0.0000 and P=0.0002, respectively).

Significance of CD44v6 expression in gynecologic malignancies

AIM

Variants of CD44 have been proposed to be important in cancer invasion and metastasis. The purpose of this study was to evaluate the diagnostic and prognostic value of CD44v6 expression in gynecologic malignancies.

METHODS

Immunohistochemistry was used to determine the expression of CD44v6 in samples from a series of 65 cases of early cervical cancer, 76 cases of endometrial samples and 57 cases of serous epithelial ovarian tumors. We analyzed the expression of CD44v6 and correlated the findings with clinicopathological factors.

RESULTS

In the cervical series, CD44v6 was detected in 60 cases of cervical cancer (92.3%). The immunoreactivity was decreased when stromal invasion reached a depth of more than 5 mm (P < 0.05). However, it was not correlated with other clinicopathological factors. In the endometrial series, CD44v6 was detected in one endometrial hyperplasia (6.7%) and in 24 endometrial cancers (100%), while it was not detected in the proliferative endometrium (P < 0.05). Immunoreactivity was decreased in grade 2 and 3 endometrial cancers compared with grade 1 (P < 0.05). In the ovarian series, CD44v6 was not detected in the benign tumors, but it was detected in four borderline malignancies (27%) and 12 carcinomas (40%). Immunoreactivity was not correlated with clinicopathological factors of ovarian cancer.

CONCLUSION

CD44v6 may be involved in stromal invasion of early squamous cervical carcinomas and in the cellular differentiation of endometrial cancer. In addition, it may be useful for early diagnosis of endometrial cancer.

CGH and CD 44/MIB-1 immunohistochemistry are helpful to distinguish metastasized from nonmetastasized sporadic pheochromocytomas

The natural course of pheochromocytomas (PCC) cannot be predicted for certain on the basis of primary histology, their malignant character can only be confirmed by the occurrence of metastases during follow-up. Based on the recently proposed PASS score for evaluation we examined 37 adrenal (36 sporadic and one familial) and six sporadic extra-adrenal paragangliomas (all designated as pheochromocytomas) with a 'malignant histology' to find additional predictive factors. Drawing upon the follow-up (18 months to 12 years, mean 5.8 years) metastasized (n=20) and nonmetastasized (n=23) courses could be distinguished. Metastasized PCC revealed significantly (P=0.03) more copy number changes on comparative genomic hybridization (CGH) (mean 8.3) than nonmetastasized tumors (mean: 4.3). The most frequent chromosomal alterations were losses on 1p (75.6%) and 3q (44%). Both were detected with identical frequency in metastasized and nonmetastasized PCC. A gain on 17q (P=0.025) was significantly predominant in malignant courses and suggests similarities in the genetic origin and progression of PCC and neuroblastomas. The proliferative activity (MIB-1 score) of metastasized PCC (n=20) was found to be significantly higher in metastasized tumors (mean 12.8% vs mean 3.5%). In contrast, the semiquantitatively scored membrane-bound staining of CD 44-S was stronger in tumors without metastases (mean 2.1 vs mean: 0.25) during the follow-up period (P<0.01). Although the results correspond to the established weight differences the tumor weight does not appear to be an independent prognostic factor. Our study suggests that CD 44-S and MIB-1 immunostaining as well as the CGH results might complement the PASS score in predicting a metastasized course of PCC. Regardless of tumor weight, tumors with a 'malignant histology' are highly prone to metastasize when more than 5% of MIB1-positive nuclei are present or CD44-S immunostaining is negative, or both. PCC with 10 or more copy number changes on CGH must be referred to as malignant tumors.

CD44 expression in papillary serous endometrial carcinoma

The objective of this paper is to evaluate the relationship between CD44 expression and the clinicopathologic features of papillary serous endometrial cancer. CD44 expression was assessed in 32 cases of papillary serous endometrial carcinoma by standard immunohistochemical staining techniques. Clinicopathologic features including myometrial invasion, nodal metastases, tumor spread, stage, and the shedding of malignant cells on cervical cytology were reviewed. The Chi-square test was used for statistical analysis. CD44 was not expressed in 81% of patients with papillary serous endometrial carcinoma. Malignant cells were seen on cervical cytology in 68% of all cases with significantly more in the CD44-negative group (78% vs. 33%, P 0.05). CD44 expression was not related to stage, myometrial invasion, nodal involvement, or intraperitoneal spread. We conclude that the cell adhesion molecule CD44 is expressed infrequently in papillary serous endometrial carcinoma. Shedding of malignant cells on cervical cytology is common in papillary serous endometrial cancer and occurs more frequently in CD44-negative cases. CD44 expression doesn't appear to be related to known prognostic features such as nodal metastases or stage. The biologic aggressiveness of this tumor type may, in part, be related to its lack of CD44 expression.

CD44 in cancer

CD44 is a multistructural and multifunctional cell surface molecule involved in cell proliferation, cell differentiation, cell migration, angiogenesis, presentation of cytokines, chemokines, and growth factors to the corresponding receptors, and docking of proteases at the cell membrane, as well as in signaling for cell survival. All these biological properties are essential to the physiological activities of normal cells, but they are also associated with the pathologic activities of cancer cells. Experiments in animals have shown that targeting of CD44 by antibodies, antisense,and CD44-soluble proteins markedly reduces the malignant activities of various neoplasms, stressing the therapeutic potential of anti-CD44 agents. Furthermore, because alternative splicing and posttranslational modifications generate many different CD44 sequences, including, perhaps, tumor-specific sequences, the production of anti-CD44 tumor-specific agents may be a realistic therapeutic approach. However, in many cancers (renal cancer and non-Hodgkin's lymphomas are exceptions), a high level of CD44 expression is not always associated with an unfavorable outcome. On the contrary, in some neoplams CD44 upregulation is associated with a favorable outcome. Even worse, in many cases different research grows analyzing the same neoplastic disease reached contradictory conclusions regarding the correlation between CD44 expression and disease prognosis, possibly due to differences in methodology. These problems must be resolved before applying anti-CD44 therapy to human cancers.

Endometrial carcinoma cells are nonpermissive for CD44-erbB2 interactions

The erbB2 receptor tyrosine kinase and the CD44 transmembrane glycoprotein interact with one another in numerous cell types. This interaction helps to maintain erbB2 activity that contributes to tumor progression. We investigated whether CD44 and erbB2 similarly interact in endometrial carcinomas in vitro and in situ. In contrast to other carcinomas, CD44 did not colocalize with erbB2 in any of the 51 cases of endometrial cancer analyzed. CD44 also did not coimmunoprecipitate or colocalize with erbB2 in two endometrial carcinoma cell lines. We propose that the lack of CD44-erbB2 interactions may reduce the contribution of erbB2 to endometrial carcinoma progression.

Determination of prognosis in patients with prostate cancer treated with radical prostatectomy: prognostic value of CD44v6 score

PURPOSE

A third of the patients treated with radical prostatectomy experience progression even when tumors are confined pathologically to the prostate. CD44 may be a promising prognostic marker for determining malignant potential. However, there has not been a standard scoring system because of its heterogeneous staining pattern. Thus, we developed an objective scoring system to evaluate reliably CD44v6 (Bender Medsystems, Vienna, Austria) as a prognostic marker for prostate cancer.

MATERIALS AND METHODS

A total of 22 patients with metastatic stage pT3bN0M0 or any pTN1M0 disease and 18 with nonmetastatic disease less than stage pT3bN0M0 were selected from a well examined group of 114 who underwent radical retropubic prostatectomy. Mean followup was 33 months (range 4 to 78). A combined CD44v6 score was determined by adding the scores of the primary and secondary areas. CD44v6 expression in terms of the CD44v6 score in primary and metastatic tissues was examined. The relationships of CD44v6 expression with pathological stage, progression and PSA-free survival were also evaluated. The prognostic value of the CD44v6 score for progression was analyzed by multivariate analysis.

RESULTS

Progression in the metastatic group was significantly higher than in the nonmetastatic group (p <0.0001). CD44v6 expression of the primary tumors differed significantly in the 2 groups (p = 0.014). The CD44v6 score in primary tumor tissues inversely correlated with pathological stage (p = 0.004) and progression (p = 0.035), and positively correlated with PSA-free survival (p = 0.041). Furthermore, patients in the nonmetastatic group with a CD44v6 score of greater than 75 (cutoff value) had a significantly better prognosis (log rank test p = 0.0022), while those with a CD44v6 score of less than 75 had a prognosis similar to those in the metastatic group. On multivariate analysis pathological stage and surgical margin positivity were independent factors for progression but the CD44v6 score was not.

CONCLUSIONS

According to our results the suggested CD44v6 score system is useful. A CD44v6 score of less than 75 may be a predictor of poor prognosis in the nonmetastatic group and this property may have potential application for planning adjuvant therapy.

Association of CD44 isoform immunohistochemical expression with myometrial and vascular invasion in endometrioid endometrial carcinoma

OBJECTIVE

Appropriate clinical management of cases of FIGO Grade I and II endometrial carcinoma relies heavily on the determination of myometrial invasion (MI). There are no reports addressing expression of the cell adhesion molecule CD44 in the subset of Grade I and II endometrioid carcinoma (EC) as it relates to prognosis, including MI.

METHODS

Immunohistochemical staining for CD44s and CD44v6 was evaluated in 40 hysterectomy specimens with Grade I and II EC, including 11 noninvasive ECs, 14 with MI <50% of myometrial thickness, and 15 with deep invasion (MI >50%). Staining characteristics according to the presence of MI and vascular space invasion (VSI) were evaluated. Strong membranous staining of >10% of tumor cells was interpreted as positive.

RESULTS

CD44v6 staining was positive in 20% (8/40) of cases, including 45% (5/11) of EC without MI but only 10% (3/29) with MI (P = 0.025). CD44v6 staining was not present in deeply invasive tumors (0/15), while it was present in 8/25 superficially or noninvasive tumors (P = 0.016). Sensitivity and specificity were 25 and 100%, respectively, using CD44v6 in evaluating deep myometrial invasion. CD44s showed a trend toward positive staining when comparing noninvasive versus invasive tumors and noninvasive/superficially invasive versus deeply invasive tumors (P = 0.08 and 0.12, respectively). CD44s or CD44v6 staining was highly specific for absence of VSI, although statistical comparison did not reach significance.

CONCLUSION

Deeply invasive EC was associated with a consistent lack of CD44v6 expression. This may have potential clinical utility if this finding is demonstrated in further study of prehysterectomy sampling specimens containing EC.