Neoplastic Endometrium Research Articles

Expression of HOXA10 in Endometrial Hyperplasia and Adenocarcinoma and Regulation by Sex Hormones In Vitro

The objective of the study was to determine the expression of HOXA10 in human endometrial tissue in endometrial hyperplasia and carcinomas, and regulation by sex steroids in Ishikawa cells. Endometrial tissue was obtained from 133 subjects with normal endometria, endometrial hyperplasia, or endometrial adenocarcinoma. Among 133 specimens, 20 were normal endometria, 19 were simple hyperplasias without atypia, 20 were complex hyperplasias without atypia, 33 were atypical hyperplasias, and 41 were endometrial adenocarcinomas. The expression of HOXA10 was analyzed by immunohistochemistry. Ishikawa cell lines were incubated with 17β estradiol (10⁻⁸ mol/L) alone, medroxyprogesterone acetate (10⁻⁶ mol/L) alone, or the combination of estrogen and progesterone for 48 hours, respectively. In certain experiments, the antiprogestin antagonist, RU486 (10⁻⁵ mol/L), was also added to Ishikawa cells along with estradiol and medroxyprogesterone acetate for 48 hours. The expression of HOXA10 gene was detected by reverse transcriptase-polymerase chain reaction and Western blotting. HOXA10 was expressed in both normal and neoplastic endometria. No significant difference in HOXA10 expression was found between normal and hyperplastic endometrial tissues. The expression of HOXA10 was decreased in endometrial adenocarcinomas compared with normal endometria. Estrogen alone, progestin alone, or progestin combined with estrogen could significantly increase the expression of HOXA10 gene (P<0.05). RU486 could inhibit the effect of up-regulation of HOXA10 expression by progestin. The expression of HOXA10 was deregulated in endometrial carcinomas and up-regulated by sex hormones.

Laser-captured microdissection-microarray analysis of the genes involved in endometrial carcinogenesis: stepwise up-regulation of lipocalin2 expression in normal and neoplastic endometria and its functional relevance

Endometrial carcinoma often arises from normal endometrial glandular cells via a precursor, atypical endometrial hyperplasia. However, the genetic changes involved in this carcinogenetic process are not fully understood. Differentially expressed genes were selected from glandular cells of normal proliferative-phase endometria, atypical endometrial hyperplasia, and endometrial carcinoma using laser-captured microdissection and microarray. The microarray analysis revealed a total of 51 genes to be up-regulated and 23 genes to be down-regulated in neoplastic endometrial epithelia. We focused on lipocalin2 (LCN2), which showed the largest magnitude of up-regulation. Immunostaining for lipocalin2 confirmed a stepwise increase in its expression in endometrial hyperplasia and carcinoma. In addition, elevated expression of lipocalin2 was correlated with the poor outcome of endometrial carcinoma patients. The subcellular distribution of lipocalin2 was both cytoplasmic and nuclear, despite reports that lipocalin2 is a secretory protein. Treatment of endometrial carcinoma cells with 5-azacytidine increased the expression of lipocalin2, suggesting the expression to be controlled by methylation of the promoter. The forced expression of lipocalin2 resulted in the enhanced cell proliferation and invasion in vitro. The expression of lipocalin2 increased with the endometrial carcinogenesis, and accumulation of the protein conferred biological aggressiveness to endometrial carcinoma cells. These results suggest lipocalin2 to be a novel target in the treatment of endometrial carcinoma.

Significance of Nuclear p-Akt in Endometrial Carcinogenesis: Rapid Translocation of p-Akt Into the Nucleus by Estrogen, Possibly Resulting in Inhibition of Apoptosis

Endometrial endometrioid adenocarcinoma (endometrial cancer) develops through endometrial hyperplasia caused by estrogenic hyperstimulation. Estrogen is known to activate growth factor signaling pathways, resulting in cellular proliferation, but precisely how has not been clarified. The aim of this study was to investigate the significance of estrogen and downstream factors such as the MAPK (MEK, ERK) and Akt pathways in endometrial carcinogenesis. The expression of p-MEK, p-ERK, and p-Akt was analyzed immunohistochemically in normal, hyperplastic, and neoplastic endometria. The estrogenic effect on p-Akt was examined using an endometrial cancer cell line (Ishikawa cells). The estrogenic effect on the apoptosis of Ishikawa cells was assessed by the TUNEL method. Phospho-MEK (p-MEK) and p-ERK expression levels were similar among histological types but correlated with each other. The nuclear p-Akt labeling index (LI) was higher in cancer than in normal endometrium and hyperplasia. The nuclear p-Akt LI of well-differentiated cancer (G1) was higher than that of moderately (G2) or poorly (G3) differentiated cancers. The nuclear expression of p-Akt was correlated with that of estrogen receptor α (ER-α). The nuclear p-Akt level was significantly correlated with prognosis in cases of G1. In Ishikawa cells transfected with ERα, p-Akt was translocated into the nucleus from the cytoplasm in 1 to 3 hours after estrogenic stimulation. Further, apoptosis induced by H2O2 was inhibited by estrogen in the ER-α-positive cells. The translocation of p-Akt into the nucleus by estrogen may be related to the suppression of apoptosis by estrogen and consequently to endometrial carcinogenesis and prognosis in G1 endometrial cancer.

Immunohistochemical analysis of steroid receptors, proliferation markers, apoptosis related molecules, and gelatinases in non-neoplastic and neoplastic endometrium

Endometrioid endometrial carcinoma developed from endometrial hyperplasia is associated with anomalies of proliferation, apoptosis, and matrix metalloproteinase (MMP) expression. Our study was designed to investigate steroid receptor (ER, PR) expression and its correlation with proliferative activity (PCNA), apoptosis (Fas, FasL, Bcl-2, Bax, and p53), gelatinases (MMP-2 and MMP-9) and their tissue specific inhibitor (TIMP-1 and TIMP-2) immunoexpression in endometrial carcinogenesis. A total of 38 cases were investigated, 10 non-neoplastic, 11 hyperplastic, and 17 carcinomatous endometria. Immunolabeling showed a higher expression of steroid receptors in hyperplasia and carcinoma than in non-neoplastic endometria and an ER/PR imbalance in carcinoma. The epithelial component of endometrial carcinomas had the highest proliferative index. Bcl-2 had a stronger expression in hyperplasia and carcinoma compared to non-neoplastic endometria and stromal tissue. The Bcl-2/Bax ratio was lower in endometrial carcinoma. Fas and FasL expression was stronger in hyperplasia and furthermore in carcinoma. p53 expression was progressively stronger along the sequence non-neoplastic endometrial to hyperplasia-carcinoma. Both types of investigated MMPs showed an increased expression in neoplastic endometria reaching a maximum level in carcinomas. MMP-9 immunostaining could be correlated to myometrial invasion. TIMP-1 decreased and TIMP-2 increased in expression from non-neoplastic endometria to hyperplastic and carcinomatous endometrial, respectively. Our study demonstrates that coordinated anomalies of steroid receptors, apoptosis and invasiveness factors are already present in hyperplasia as cumulative steps along the way to malignant transformation and that a complex MMP-2, MMP-9, TIMP-2/TIMP-1 imbalance seems to be responsible for the endometrial proliferation.

Repression of Translation of Human Estrogen Receptor α by G-Quadruplex Formation

Tissue-specific expression of the human estrogen receptor alpha gene (ESR1) is achieved through multiple promoter sequences resulting in various mRNA transcripts encoding a common protein but differing in their 5'-untranslated region (5'-UTR). Many cancers are estrogen-sensitive with neoplastic growth stimulated through the estrogen receptor, a transcription factor that regulates developmental genes. We demonstrate that the human ESR1 gene is rich in potential quadruplex-forming sequences with 3 of 20 identified within exonic regions. In particular, we show using CD, UV, and NMR spectroscopy that a stable DNA G-quadruplex motif is formed within the exon C gene sequence. This motif, which PCR shows is transcribed in normal and neoplastic endometrium and in MCF-7 cells, forms a stable RNA quadruplex demonstrable by CD and UV analysis. Cloning the exon C G-quadruplex sequence upstream of a luciferase reporter gene caused a 6-fold reduction of enzymatic activity compared to a mutant sequence. We conclude that the exon C G-quadruplex motif is present in the 5'-UTR of the mRNA transcript, where it modulates the efficiency of translation.

Adrenomedullin, Bcl‐2 and microvessel density in normal, hyperplastic and neoplastic endometrium

Adrenomedullin (ADM) is a multifunctional 52-amino acid peptide involved in numerous physiological and pathological processes, including angiogenesis, growth regulation, differentiation, and vasodilation. ADM is thought to act through the G protein-coupled receptor calcitonin receptor-like receptor, with specificity being conferred by receptor-associated modifying protein 2. The aim of the present study was to clarify the roles of ADM status, and tumor vessels in endometrium. Specimens were examined for ADM, microvessel density (MVD), area of venules (AV) and Bcl-2 oncoprotein using an immunoperoxidase method. The difference of ADM between normal proliferative phase and hyperplasia without atypia was significant (P < 0.05). The level of Bcl-2 was significantly different between hyperplasia without atypia and hyperplasia with atypia (P < 0.05). ADM, MVD and AV in the endometrium increased in a stepwise manner from normal, simple or complex hyperplasia with or without atypia to grade 1 adenocarcinoma. In contrast, expression of Bcl-2 oncoprotein was decreased. These parameters identify the role of ADM expression and Bcl-2 protein in relation to cell growth and vasodilating in the neoplastic changes.

Expression of immunoreactivity and genetic mutation in eosinophilic and ciliated metaplastic changes of endometrial glandular and stromal breakdown: cytodiagnostic implications

Various metaplastic changes may be present in endometrium, in which also cellular atypias may often be observed. Particularly, eosinophilic and ciliated changes (ECCs) occur in both nonneoplastic and neoplastic endometrium. This may cause confusion in the cytodiagnosis. This study was enterprised to investigate the possible help of immunocytochemical and cytogenetic study in the diagnostic and biologic assessment of ECC cells. In immunocytochemistry for p53 protein, Ki-67, and cyclin A, the material consists of 40 cases of cytologic smears examined by direct sampling of the endometrial cavity comprising 30 cases of ECC in endometrial glandular and stromal breakdown (EGBD) and 10 cases of well-differentiated adenocarcinoma (G1). After cytodiagnosis, immunostaining for p53 protein, Ki-67, and cyclin A was performed on multiple wet-fixed slides from each single case to evaluate the immunoreactivity, intensity of nuclear staining, and nuclear labeling index (N-LI). The intensity of nuclear staining was scored as negative (0), weak (1), moderate (2), or strong (3), and the N-LI was scored as less than 10% (0), from 10% to 25% (1), from 26% to 50% (2), or more than 50% (3), and the final score was calculated by adding both partial scores. A statistical significance test was performed by using Mann-Whitney U test, and the result was judged as significant when the P value was less than .05. For genetic mutation analysis of p53, the material comprised 6 cases of EGBD in which a high score was measured with immunocytochemistry for p53 protein, and the presence of ECC was confirmed on the hematoxylin and eosin. The ECC cells on paraffin-embedded specimens were captured using laser capture microdissection technology. Mutations in p53 gene (exons 5-8) were examined using DNA sequencing analysis. In immunocytochemistry for p53 protein, Ki-67, and cyclin A, the proportions of immunoreactive cells for p53 were statistically higher in ECC compared with those of G1 (P < .05). The proportions of the immunoreactive cells for Ki-67 and cyclin A were statistically higher in G1 compared with those of ECC (P < .05). (2) In genetic mutation analysis of p53, DNA sequencing of p53 in 6 cases revealed no mutations. The percentage of immunoreactive cells for p53 protein were higher in ECC than in G1, but the mutation point was not confirmed in genetic mutation analysis. The differential expression of these biologic parameters in ECC cells could be considered of possible relevance to the cytopathologic diagnosis in the future.

Diagnostic value of endometrium associated with papillary metaplastic changes in endometrial cytopathology

Papillary metaplastic changes especially occur in both non-neoplastic and neoplastic endometrium. We tried to investigate to assess the relationship between endometrial cytologic diagnosis and papillary metaplasia. The material consists of 160 cases of cytologic smears obtained by direct sampling of the endometrial cavity comprising 54 cases of normal proliferative endometrium (NPE), 36 cases of glandular and stromal breakdown (EGBD), and 70 cases of endometrial hyperplasia without atypia (EH). As for the correlation between the appearance of papillary metaplasia and cytological diagnosis, a statistical significance test was performed. The material consists of 40 cases of cytologic smears examined by direct sampling of the endometrial cavity comprising 10 cases of EGBD with papillary metaplasia, 10 cases of G1 without papillary metaplasia, 10 cases of NPE without papillary metaplasia, and 10 cases of EH without papillary metaplasia. Using the comparison between appearance of papillary metaplasia and cytological diagnosis, a significant difference was only seen in the rate of correct diagnoses in EGBD cases. The nuclear area of papillary metaplastic cells in EGBD was 888.8, G1 was 928.7, NPE was 682.0, and EH was 722.2. Significant difference was observed between ECC cells in EGBD to NPE, between papillary metaplastic cells in EGBD to EH, between G1 to NPE, or between G1 to EH. This study provides new and important information on the correlation between endometrial cytological diagnosis and papillary metaplastic changes.

Evidence for a latent precursor (p53 signature) that may precede serous endometrial intraepithelial carcinoma

Both serous intraepithelial carcinoma and endometrial glandular dysplasia are associated with uterine serous carcinoma. Recently a candidate serous cancer precursor containing p53 mutations (p53 signature) was described in the fallopian tube. We analyzed normal and neoplastic endometrium for a similar entity. In total 10 endometrial polyps involved by intraepithelial and/or invasive carcinoma and 137 benign polyps were studied. All were stained for p53 and MIB-1. A subset of p53 signatures and carcinomas were analyzed for γ-H2AX and p53 mutations. p53 signatures were identified in 7 of 10 cases intraepithelial carcinoma and were multicentric in 2. In one case, the signature was in continuity with intraepithelial carcinoma. Of 137 benign polyps (4%), 6 contained p53 signatures. The MIB-1 fraction in most signatures was less than 5%, and ranged from 50 to 90% in carcinomas. DNA damage (γ-H2AX) was demonstrated in both p53 signatures and adjacent carcinomas but not in benign polyps. Shared identical p53 mutations were found in paired signatures and carcinomas in two of three cases analyzed, including one case with multiple signatures. In one, a coexistent invasive serous cancer was not found to contain a p53 mutation. In a third, a p53 signature and an invasive cancer harbored two different p53 mutations. This is the first description of p53 signatures adjacent to carcinoma, suggesting a role for this entity in the genesis of serous malignancy. The significance of p53 signatures in benign conditions (polyps) remains to be determined. The role of the p53 signature in early serous neoplasia is discussed.

Altered PTEN expression; a diagnostic marker for differentiating normal, hyperplastic and neoplastic endometrium

BackgroundDifferent molecular alterations have been described in endometrioid endometrial carcinoma (EECA). Among them the most frequently altered is loss of the PTEN protein, a tumor suppressor gene. The purpose of this study was to evaluate the expression pattern of PTEN gene in normal, hyperplastic and neoplastic endometrium.MethodsIn a study in a referral gynecologic hospital in Tehran, Iran, immunohistochemical (IHC) evaluation of PTEN was performed on 87 consecutive specimens to the following three groups; group A- normal proliferative endometrium(n = 29); group B- hyperplastic endometrium [including simple hyperplasia without atypia(n = 21) and complex hyperplasia with atypia (n = 8)] and group C- EECA(n = 29). Immunostaining of cells was analyzed by arbitrary quantitative methods according to both slide's area staining and intensity of color reaction.ResultsPTEN immunoreactivity was present in all normal proliferative endometrium, all simple hyperplasia, 75% of atypical complex hyperplasia and in 48% of EECA (P < 0.001). The intensity of PTEN reaction was significantly higher in group with proliferative endometrium than hyperplastic endometrium and EECA (P < 0.001).ConclusionPTEN expression was significantly higher in cyclical endometrium than in atypical hyperplasia and endometrioid carcinoma.

Estrogen Receptor Beta (ERβ) in Endometrial Simple Hyperplasia and Endometrioid Carcinoma

The aim of this study was to analyze the expression of estrogen receptor (ER) beta in endometrioid carcinoma in comparison to non-neoplastic endometrium. Fifty-seven histopathologically confirmed non-neoplastic endometria (22 proliferative phase, 15 secretory phase, and 20 simple hyperplasia without atypia), and 26 cases of endometrioid carcinoma were studied. The ERbeta/ERalpha transcript ratio was determined by semiquantitative reverse transcription-polymerase chain reaction. The receptor protein expression was evaluated by immunohistochemistry using the Allred Scoring System. Decreased expression of ERbeta, ERalpha, and progesterone receptor proteins was observed in endometrioid carcinoma compared with proliferative endometrium and simple hyperplasia (P<0.01, Mann-Whitney U test). Within the group of endometrioid carcinoma, a correlation of increased ERbeta expression with tumors exhibiting > or =50% myoinvasion (P=0.034) was observed, whereas there was no correlation with the grade of tumor (P=0.314). There was a significant association of ERbeta with ERalpha expression in both non-neoplastic and neoplastic endometrium indicating interdependence of expression. Progesterone receptor protein expression was influenced by ERalpha levels and not by ERbeta as shown by regression analysis in non-neoplastic and neoplastic endometrium. Thus, ERbeta alterations are important in endometrioid carcinoma. The relationship of ERbeta expression to myoinvasion warrants further investigation.

Sulfatase Activity in Normal and Neoplastic Endometrium

Background: Dehydroepiandrosterone sulfate (DHEAS) is metabolized to active androgens and estrogens, which may have a role in the development of endometrial cancer. Methods: We studied DHEAS conversion to dehydroepiandrosterone (DHEA) in normal and neoplastic endometrium utilizing gas chromatography-mass spectral (GC-MS) analysis. Endometrial homogenate was incubated with known amounts of DHEAS for 4 h at 37°C. Methanol extract was separated from debris by centrifugation, concentrated to 200 μl and 1 μl injected into the GC-MS instrument, equipped with a CP-Sil 8 column. DHEAS and DHEA areas were calculated by autoquantization and DHEA/DHEAS ratio was used for comparing sulfatase activity among normal endometrium (n = 6), Stage I endometrioid carcinoma (EC) (n = 15), Stage I mixed mesodermal Müllerian tumor (MMMT) (n = 6) and Stage I uterine papillary serous carcinoma (UPSC) (n = 7). Results: DHEA/DHEAS ratios in normal endometrium, EC, MMMT and UPSC were 1.45 ± 1.10, 5.63 ± 3.27, 2.88 ± 0.99, and 3.04 ± 1.76, respectively. Sulfatase activity was significantly higher in EC when compared with normal endometrium (p < 0.001), MMMT (p < 0.05), and UPSC (p < 0.05). The enzyme activity did not differ significantly between low-grade and high-grade EC tumors (5.8 ± 2.77 and 5.49 ± 3.84, respectively, p > 0.05). Conclusion: Stage I EC have higher sulfatase activity than normal endometrium, and Stage I MMMT and UPSC tumors.

Calretinin and CD34 immunoreactivity of the endometrial stroma in normal endometrium and change of the immunoreactivity in dysfunctional uterine bleeding with evidence of ‘disordered endometrial stroma’

We investigated the pattern of reactivity of calretinin and CD34 in normal and pathological endometria. Various endometrial tissues were submitted for calretinin and CD34 immunostaining. Calretinin reactivity was limited to the endometrial stromal cells (ESC) of the superficial zone of the functionalis layer (FL) in the proliferative phase, and was extensive in all stages of the secretory phase. The ESC of the post-menopausal, ectopic, hyperplastic or neoplastic endometria showed negative or focal weak reactivity for calretinin. In dysfunctional uterine bleeding (DUB) with a normal or an abnormal histopathological appearance on routine stain, there were varying degrees of focal to extensive decreases in calretinin reactivity. The foci of negative calretinin reactivity in the FL displayed varying reactivity for CD34 and appeared to be continuous with the basalis layer (BL). Endometrial polyps were often reactive for CD34, but not reactive for calretinin. Immunostaining for calretinin and CD34 is helpful in the diagnosis of endometrial polyp and hyperplasia. In DUB, with or without abnormal histopathological findings, there were alterations of the zonal pattern of calretinin reactivity in the FL. This alteration appears to be an expansion of the stroma of the BL into the FL, resulting in a 'disordered endometrial stroma'.

Endometrial Glandular Dysplasia with Frequent p53 Gene Mutation: A Genetic Evidence Supporting Its Precancer Nature for Endometrial Serous Carcinoma

Endometrial glandular dysplasia (EmGD) has been recently proposed to be a putative precursor to endometrial serous carcinoma (ESC). The purpose of this study is to determine if EmGD is genetically linked to ESC and if it can be used for early detection. The tumor suppressor p53 gene was sequenced from serial samples of benign and neoplastic endometria with serous differentiation. The study group contained 15 neoplastic uteri and the control group had 12 age-matched benign uteri. A total of 139 informative samples were obtained, including 55 resting endometrium, 37 EmGD, 25 serous endometrial intraepithelial carcinoma (EIC), and 22 ESC. At least one representative section from each uterus was used for p53 immunohistochemical staining to correlate p53 overexpression with gene mutation status. The mutations of p53 were detected in 0%, 43%, 72%, and 96% in resting endometrium, EmGD, serous EIC, and ESC, respectively. More than 50% of the neoplastic uteri showed at least one identical p53 gene mutant among lesions of EmGD, serous EIC, and/or ESC. The majority of lesions showed overexpression of p53 protein, which was significantly correlated with p53 gene mutation (P < 0.01). This genetic evidence strongly supports that EmGD represents the precancer of ESC or serous EIC. Mutation of p53 gene is probably one of the most important factors to initiate the endometrial serous carcinogenesis. Correct identification of EmGD will provide us an opportunity of early diagnosis and a potentially effective therapeutic modality to control ESC.

The Immunohistochemical Evaluation of Estrogen Receptor-α and Progesterone Receptors of Normal, Hyperplastic, and Neoplastic Endometrium in 88 Pet Rabbits

The expression of estrogen receptor-alpha (ER) and progesterone receptor (PR) in normal, hyperplastic, and neoplastic endometrium in rabbits was evaluated by immunohistochemistry. The tissues evaluated were 27 normal uteri, 19 cases with endometrial hyperplasia, and 42 adenocarcinomas. Sixteen of 27 cases of normal uteri (59.3%) and 13 out of 19 hyperplasias (68.4%) stained positive with both ER-alpha and PR. Adenocarcinomas were further subdivided into 26 papillary and 16 tubular/solid adenocarcinomas. Papillary adenocarcinoma infiltrated the myometrium late in the disease and caused attenuation of the myometrium. In contrast, tubular/solid adenocarcinoma invaded into the deep myometrium early in the disease without thinning of the myometrium. Twenty-one cases out of 26 (80.8%) cases of papillary adenocarcinoma were both ER-alpha and PR negative, whereas 15 out of 16 (93.8%) of the tubular/solid adenocarcinomas were positive for ER-alpha, PR, or both. The total immunoreactive scores of ER-alpha, PR, and mode of myometrial invasion were significantly different between histopathologic types. This suggests that there may be 2 different developmental pathways for uterine adenocarcinomas in the rabbit.

Objective risk definition for endometrial lesion spectrum: A diagnostic algorithm

Objective. Investigations for risk definition in endometrial lesion spectrum still go on. In this study, molecular, morphometric, immunohistochemical techniques were combined with conventional morphology to realize whether an algorithm is definable for risk assessment to progress an invasive carcinoma in endometrial glandular lesion spectrum is possible. Methods. The study was carried out on 20 benign endometria, 35 hyperplasias, and 20 adenocarcinoma cases. Clonality of glandular cells, the volume percent of endometrial stroma (VPS), PTEN inactivation, and proliferative index (PI) were evaluated. Statistical analysis was evaluated to set an objective algorithm. Results. All benign tissues had polyclonal (PC), whereas all malignant tissues had monoclonal (MC) glandular epithelium. Of hyperplasias, 19 were MC, and 16 were PC. VPS value of 55% had 100% sensitivity, and 80% specificity ( n = 67) to distinguish MC from PC. Neither PTEN nor PI data augmented the specificity or the sensitivity of clonal distinction. Conclusion. Clonality and VPS values were found to be significant in differential of endometrial lesions. With this rationale, a diagnostic algorithm for endometrial risk lesions was set. This algorithm is based on HE morphology, VPS and clonality findings, and has 100% sensitivity and specificity to discriminate neoplastic endometrium from hyperplasia.

Angiogenic factors in normal endometrium and endometrial adenocarcinoma

In the endometrium, angiogenesis plays important roles not only in tumor growth but also in the menstrual cycle. The purpose of the present paper was to investigate immunohistochemically the correlation between angiogenic factor expression and angiogenic score in normal and neoplastic endometrium. Immunohistochemical staining for vascular endothelial growth factor (VEGF), angiopoietin (Ang)-1, Ang2, Tie2, CD34 and CD105 was performed on formalin-fixed and paraffin-embedded tissues from 31 normal endometrium and 85 endometrial adenocarcinoma. VEGF, Ang1, Ang2 and Tie2 expression was localized in the cytoplasm of glandular and tumor cells. The levels of each angiogenic factor were different in the phases of the menstrual cycle and each layer of normal endometrium. In general, VEGF and Tie2 expression was higher in adenocarcinoma than in normal epithelial cells. Conversely, Ang1 and Ang2 expression was higher in normal epithelium than in adenocarcinoma. The angiogenic score (CD105/CD34) tended to be higher in the adenocarcinoma than in the normal epithelium. It is suggested that the angiogenic pathway and the role of these factors seem to differ between normal tissue and carcinoma of the endometrium.

Calretinin: An immunohistochemical marker for the normal functional endometrial stroma and alterations of the immunoreactivity in dysfunctional uterine bleeding

Calretinin has been identified in the central nervous system, in various endocrine and mesothelial cells, and is often used as an immunohistochemical tool in the pathologic diagnosis. We have recently observed its presence in the endometrial stromal cells (ESC) of the normal functionalis (FL). Endometrial tissue from various physiologic and pathologic conditions was submitted for immunostaining for calretinin. For each condition, two to ten samples were tested. Calretinin displayed a strong cytoplasmic and occasionally nuclear reactivity for ESC of the normal FL in all physiologic phases of the normal menstrual cycle except for the breakdown period. Reactivity was limited in the superficial zone of the FL in proliferative phase, and was extensive in all stages of secretory phase. The ESC of the basilis layer, postmenopausal women, endometriotic and adenomyotic tissue, endometrial polyps, hyperplasia, carcinoma, and ESC neoplasms were not reactive for the marker. In endometrial specimens from patients with dysfunctional bleeding, there were varying degrees of decrease in reactivity in a patchy pattern. We demonstrated for the first time that calretinin reactivity of the ESC is strong and diffuse in a zonal pattern in the normal FL of the normal cycling endometrium. In endometrium with dysfunctional bleeding, postmenopausal, ectopic, hyperplastic, and neoplastic endometria, the ESC displayed focally decreased to negative reactivity. Calretinin can be used as a marker for normally functional ESC. Further study is necessary to investigate the mechanism and the role that calretinin plays in the physiologic cyclic changes of the endometrium.

Immunohistochemical characterization of cancer antigen in uterine cancers

The pattern of cancer antigen (CA-125) expression by immunohistochemistry (IHC) was investigated in malignant and nonneoplastic endometrium in endometrial carcinoma. Ninety cases of primary uterine carcinomas (65 endometrioid [EM] carcinoma, 15 serous papillary [SP] carcinoma, 6 carcinosarcomas [malignant mixed müllerian tumors], and 4 clear cell carcinoma [CC]) and adjacent atrophic and/or hyperplastic endometrium were analyzed by IHC for CA-125 expression. The percentage and intensity of luminal, apical, basal, and diffuse cytoplasmic immunostaining of epithelial cells were categorized on a scale of 0-4. The immunoreaction score (IRS score) was calculated and correlated with the grade and stage of carcinoma according to the histologic type. CA-125 expression (3-4/4) was localized in apical borders of grade 1 and grade 2 EM carcinoma and was weak or negative (0-1/4) in grade 3 EM. Mucinous differentiation in EM was associated with intense luminal and apical staining. Squamous areas and stroma showed no staining at all. SP carcinoma and endometrial intraepithelial carcinoma showed much higher mean IRS score than EM. In malignant mixed müllerian tumors (MMMT), the epithelial component stained as above according to the type of epithelial cell differentiation of the neoplastic cells. Benign proliferative glands showed moderate apical luminal, basal, and cytoplasmic staining. Intense diffuse staining was observed in atypical complex hyperplasia. Different patterns of CA-125 immunostaining were observed in normal, hyperplastic, and neoplastic endometrium. IRS score correlated with the grade but not with the stage of EM carcinoma. The intense different staining pattern of endometrium with atypical complex hyperplasia suggests that CA-125 may be a useful diagnostic aid.

Metalloproteinase-2, -7 and -9 and tissue inhibitor of metalloproteinase-1 and -2 expression in normal, hyperplastic and neoplastic endometrium: a clinical-pathological correlation study

Background: Matrix metalloproteinases (MMPs) and their inhibitors are key-players in extracellular matrix and basement membrane degradation, and are involved in both physiological and malignant processes. The aim of this study was to examine MMP-2, -7 and -9 and TIMP-1 and -2 expression in normal, hyperplastic and malignant endometrium, and their relation to clinical and histological prognostic factors.Materials and methods: We performed qualitative and semi-quantitative immunohistochemical analysis of 20 samples of normal endometrium (10 in the proliferative phase, 10 in the secretory phase), 39 samples of hyperplastic endometrium (17 without atypia and 22 with atypia) and 38 samples of endometrioid carcinoma, by using specific monoclonal antibodies.Results: In normal endometrium, epithelial expression of MMP-2 (P = 0.0007), MMP-7 (P = 0.0002) and TIMP-2 (P = 0.0004) was increased during the proliferative phase of the menstrual cycle. MMP-2 expression correlated negatively with TIMP-2 expression (P = 0.001, ρ = 0.702). Endometrial stromal cells in the secretory phase showed strong MMP-2 expression (P = 0.004) and weak MMP-7 (P = 0.001) and TIMP-1 expression (P = 0.01). In hyperplastic endometrium, the presence of atypia was associated with lower TIMP-2 expression (P = 0.005) and was also associated with a trend towards higher MMP-2 expression. Endometrial stromal cell expression of MMP-2, -7 and -9 and TIMP-1 and -2 did not differ between hyperplastic endometrium with and without atypia. A gradient of MMP-2 and -9 expression was observed from hyperplastic endometrium to endometrial carcinomas. In endometrial carcinomas, MMP-2 expression increased (P = 0.0004) and TIMP-2 expression decreased (P = 0.0005) with the histological grade. TIMP-2 expression correlated with myometrial invasion (P = 0.005), lymphovascular space involvement (P = 0.008) and lymph node involvement (P = 0.007).Conclusion: These results support the involvement of MMPs and TIMPs in endometrial carcinogenesis. Strong MMP-2 and weak TIMP-2 expression were the most potent markers of endometrial malignancies with a high risk of local and distant spread.