Galectin-3 expression in uterine endometrioid adenocarcinoma: comparison of staining in conventional tumor glands and in areas of MELF pattern myometrial invasion

Proteomic Changes Associated With Endogenous FBXW7 Mutations in Moderately Differentiated Endometrial Cancer Cells Include Increased TROP2 and Galectin-3 Levels

BACKGROUND

Endometrial cancer (EC) is the fourth most commonly diagnosed cancer among women in the US and the fifth leading cause of cancer death in this population. The FBXW7 tumor suppressor gene is frequently mutated in all molecular subtypes of EC. The encoded protein is part of a ubiquitin ligase complex that targets substrate proteins for ubiquitination and, in most instances, proteasome-mediated degradation.

AIMS

The purpose of this investigation was to identify the proteomic changes associated with endogenous FBXW7 mutations in EC.

MATERIALS & METHODS

Quantitative LC-MS/MS was used to identify significant (p < 0.05) differences in the proteomes and phosphoproteomes of two FBXW7-mutated EC cell lines, HEC-1-BFBXW7-R367X and JHUEM-1FBXW7-R505C, as compared to isogenic mutation-corrected cell lines. Western blotting was performed to orthogonally validate a subset of protein changes.

RESULTS

Analysis of LC-MS/MS results identified 397 total proteins and/or phosphoproteins with significantly different levels in both HEC-1-BFBXW7-R367X and JHUEM-1FBXW7-R505C, as compared to isogenic mutation-corrected cell lines. This protein set included increased levels of TROP2, galectin-3, ASS1, and PLCG2 in both HEC-1-BFBXW7-R367X and JHUEM-1FBXW7-R505C cells; these perturbations orthogonally validated by western blotting.

CONCLUSION

This study provides novel insights into the proteomic and phosphoproteomic effects of the endogenous FBXW7-R367X and FBXW7-R505C mutations in EC cells, including increased levels of galectin-3, a potentially druggable target, and of TROP2, which is a druggable target in EC.

Endocervical Adenocarcinoma Showing Microcystic, Elongated, and Fragmented (MELF) Pattern of Stromal Invasion: A Single-Institutional Analysis of 10 Cases with Comprehensive Clinicopathological Analyses and Ki-67 Immunostaining

Microcystic, elongated, and fragmented (MELF) pattern of invasion has seldom been documented in endocervical adenocarcinoma (EAC). The aim of this study was to analyze the clinicopathological characteristics of EAC showing MELF pattern. We collected the clinicopathological information of 10 cases of EAC with the MELF pattern and conducted polymer-based immunostaining for Ki-67 (dilution 1:200, clone MIB-1) on these cases. Ki-67 expression was assessed using the average estimation within the hotspot method. All tumors were human papillomavirus-associated EAC with Silva pattern C. All except one tumor exceeded 3 cm in size. Five tumors involved the entire thickness of the cervical stroma, and four tumors extended into the parametrium. Lymphovascular space invasion was identified in six cases. Two patients developed metastatic recurrences in the para-aortic lymph nodes and lungs, respectively. The MELF area showed significantly lower Ki-67 labelling index than that of a conventional tumor area. We confirmed our previous observation that the MELF area displayed lower proliferative activity than the conventional tumor area of EAC. We also demonstrated that patients with EAC showing MELF pattern had several adverse clinicopathological characteristics reflecting aggressive behavior. On the other hand, since the frequencies of post-operative recurrence and disease-related mortality that occurred during the follow-up period were relatively low, further investigations are warranted to clarify the prognostic value of MELF pattern in EAC patients.

In-depth quantitative proteomics analysis revealed C1GALT1 depletion in ECC-1 cells mimics an aggressive endometrial cancer phenotype observed in cancer patients with low C1GALT1 expression

BACKGROUND

Endometrial cancer (EC) is the most common cancer of the female reproductive organs. Despite the good overall prognosis of most low-grade ECs, FIGO I and FIGO II patients might experience tumor recurrence and worse prognosis. The study of alterations related to EC pathogenesis might help to get insights into underlying mechanisms involved in EC development and progression.

METHODS

Core tumoral samples were used to investigate the role of C1GALT1 in EC by immunohistochemistry (IHC). ECC-1 cells were used as endometrioid EC model to investigate the effect of C1GALT1 depletion using C1GALT1 specific shRNAs. SILAC quantitative proteomics analyses and cell-based assays, PCR, qPCR, WB, dot-blot and IHC analyses were used to identify, quantify and validate dysregulation of proteins.

RESULTS

Low C1GALT1 protein expression levels associate to a more aggressive phenotype of EC. Out of 5208 proteins identified and quantified by LC-MS/MS, 100 proteins showed dysregulation (log2fold-change ≥ 0.58 or ≤-0.58) in the cell protein extracts and 144 in the secretome of C1GALT1 depleted ECC-1 cells. Nine dysregulated proteins were validated. Bioinformatics analyses pointed out to an increase in pathways associated with an aggressive phenotype. This finding was corroborated by loss-of-function cell-based assays demonstrating higher proliferation, invasion, migration, colony formation and angiogenesis capacity in C1GALT1 depleted cells. These effects were associated to the overexpression of ANXA1, as demonstrated by ANXA1 transient silencing cell-based assays, and thus, correlating C1GALT and ANXA1 protein expression and biological effects. Finally, the negative protein expression correlation found by proteomics between C1GALT1 and LGALS3 was confirmed by IHC.

CONCLUSION

C1GALT1 stably depleted ECC-1 cells mimic an EC aggressive phenotype observed in patients and might be useful for the identification and validation of EC markers of progression.

Patterns of Myometrial Invasion in Endometrial Adenocarcinoma with Emphasizing on Microcystic, Elongated and Fragmented (MELF) Glands Pattern: A Narrative Review of the Literature

Endometrioid endometrial adenocarcinoma (EEC) is the most common malignancy of the female genital tract. According to the 2009 FIGO staging system, the depth of myometrial invasion (MI), and tumor spread to adjacent organs or tissues are the staging criteria for endometrial carcinoma (EC). Therefore, assessment of the depth of MI is of great importance. There is a spectrum of morphological patterns of MI. Still, their number and features vary according to the scientific literature, with a certain overlap that creates difficulties and controversies in the precise assessment of MI depth. The purpose of this review is to present and discuss the most important and recent information about patterns of MI, focusing on the more aggressive and the elongated and fragmented glands (MELF) pattern in particular. Assessment of MI depth and correct staging of EC is possible only after the precise recognition of each MI pattern.

POLE mutation combined with microcystic, elongated and fragmented (MELF) pattern invasion in endometrial carcinomas might be associated with poor survival in Chinese women

OBJECTIVE

POLE mutation is a prognostic marker associated with excellent outcome in endometrial carcinoma (EC). However, these EC tumors frequently have aggressive histology. The aim of this study was to determine how to integrate the implications of POLE mutations into existing risk assessment strategies and further stratify patients.

METHODS

We detected POLE mutations in a cohort of 426 ECs from Chinese women and observed their prognostic significance in terms of survival and recurrence outcomes in combination with histological and other molecular characteristics, including microcystic, elongated and fragmented (MELF) pattern invasion, histologic subtype, tumor grade, myometrial invasion and p53 protein and mismatch repair protein expression status.

RESULTS

POLE mutations were identified in 38 of 426 ECs (8.9%). The most common mutations were P286R (31.6%), V411L (15.8%) and Q453R (15.8%). We confirmed that POLE mutation was associated with improved overall survival (P = .047), although it did not show a statistically significant relationship with progression-free survival (P = .45). Interestingly, further analyses indicated that in POLE-mutant tumors, MELF pattern invasion was associated with a 15.1-fold increase in tumor recurrence or progression risk (HR = 15.1, 95%CI = 1.57-145.3, P = .018), whereas this phenomenon was not present in the POLE-wild-type subgroup (HR = 0.90, 95%CI = 0.39-2.08, P = .80). Furthermore, higher staging and deeper myometrial invasion also showed much higher risk in patients harboring POLE mutations compared with those without POLE mutations.

CONCLUSIONS

Although POLE mutation was associated with favorable overall survival, the combined consideration of POLE mutation status and established clinicopathologic factors in the risk assessment of endometrial cancer is more accurate than the consideration of clinicopathologic factors alone and might lead to precise and individualized therapeutic strategies.

Pathological features, immunoprofile and mismatch repair protein expression status in uterine endometrioid carcinoma: focus on MELF pattern of myoinvasion

AIMS

Microcystic, elongated, and fragmented (MELF) pattern of myoinvasion has been related with increased risk of lympho-vascular space invasion (LVSI) and lymph node metastasis. We analysed a cohort of endometrioid endometrial carcinomas (EECs) to examine the relationships between the MELF pattern of invasion and the clinico-pathological and immunohistochemical features of EEC.

METHODS AND RESULTS

129 EECs were evaluated for the presence of MELF pattern and immunohistochemically tested for Mismatch repair (MMR) proteins, p16, p53 and beta-catenin. We observed 28 MELF + EECs and 101 MELF- EECs. LVSI was observed in 20 MELF + cases and in MELF- tumors. Lymph-node metastases were observed in 7 MELF + cases (2 macrometastases, 3 micrometastases and 2 ITCs). None of the MELF- cases showed micrometastases or ITCs, 18 cases had macrometastatic lymph-nodes. Statistical analysis showed that MELF + tumors carry an increased risk of developing nodal metastasis independent of tumor dimension and LVSI. Loss of MMR proteins expression was observed in 11 MELF + cases and 45 MELF- cases, respectively. Our data showed a higher frequency of immunohistochemical MLH1-PMS2 loss in MELF- pattern of invasion (32.67% of MELF- cases vs 21.43% of MELF + cases) but a higher prevalence of MSH2-MSH6 loss in MELF + pattern (7.14% in MELF + population vs 3.96% of MELF- population) CONCLUSIONS: The morphological recognition of MELF pattern is more reliable than immunohistochemical and molecular signatures of EEC in predicting the risk of nodal involvement. The observed higher prevalence of MSH2-MSH6 loss in MELF + group and MLH1-PMS2 loss in MELF- group may suggest a different molecular signature.

The Role of Galectins in Tumor Progression, Treatment and Prognosis of Gynecological Cancers

Galectins are the member of soluble proteins that bind with β-galactoside containing glycans. These proteins have been considered to be associated in various important events such as different types of cancers. It has been found that galectins could contribute to neoplastic transformation or regulate cell growth, cell apoptosis, and immune cells, causing tumor invasion, progression, metastasis and angiogenesis. Somehow, galectins are also found to exert a protective effect on cancer in a tissue-dependent way. These glycans binding proteins have been shown to be involved in the regulation of different tumor suppressor genes and oncogenes with their possible roles in human cancers. Objective of the current review is to summarize the role of galectin-1, -3 -7, and -9 in tumorigenesis of gynecological cancers. Galectin protein may be a potential therapeutic target in gynecological malignancies due to reported radio- and chemo- sensitivities, immunotherapeutic, anti-angiogenic and anti-proliferative activities. This review considers the evidence for the future research that how galectins may be important in the progression and treatment of gynecological cancers along with its potent use as a novel prognostic marker.

Tumor-Associated T-Lymphocytes and Macrophages are Decreased in Endometrioid Endometrial Carcinoma with MELF-Pattern Stromal Changes

Microcystic, elongated, fragmented (MELF)-pattern is an unusual morphology of myometrial invasive front in endometrioid endometrial carcinoma (EA). The aim of the study was to investigate potential correlation between MELF-pattern and peritumoral inflammatory immune response. A total of 96 out of 368 patients were included in this study. CD3, CD20, CD57. CD68 and S100 markers were used for the detection of tumor-associated T-lymphocytes (TAT), tumor-associated B-lymphocytes (TAB), tumor-associated NK-lymphocytes (NK), tumor-associated macrophages and dendritic cells respectively. Mann-Whitney tests, receiver operating characteristic (ROC) curve analysis, and Spearman correlation were used as methods for statistical analyses. Odds ratio with 95% confidence interval (95% CI) was determined with the use of a logistic regression model. A p < 0.05 was considered statistically significant. Our results suggested that the number of CD3 and CD68 cells were significantly lower (p < 0.001) in cases of endometrioid carcinoma with MELF-pattern. A significant correlation between the presence of MELF-pattern and decrease of CD3 positive T-lymphocytes (r = 0.691; p < 0.001) was also observed. Additionally, we found an inverse correlation between the presence of MELF-pattern and TAM (r = 0.568; p = 0.001). Therefore, our data suggest that MELF-pattern may be associated with EA stroma fibrosis that contains immune cells infiltration and demonstrated a decrease in the number of TAT and TAM cells. This may indicate the poor clinical prognosis of this disease.

[MELF pattern in myometrial infiltration in endometrioid adenocarcinoma of the endometrium. A retrospective study of 70 cases]

INTRODUCTION

Endometrioid adenocarcinoma of the endometrium (EAE) usually has a favorable prognosis. Recently, the MELF (microcystic, elongated and fragmented) pattern of myometrial infiltration has been described. It is associated with lymphovascular invasion and lymph node metastasis. Seventy cases of EAE were reviewed to identify the presence of MELF and its correlation with other prognostic factors.

MATERIAL AND METHODS

Hysterectomies performed for EAE during a 5-year period were reviewed, searching for MELF pattern. Its presence was correlated with other variables such as histological grade, depth of myometrial infiltration, pelvic and/or aortic lymph node metastasis, peritoneal implants and evolution.

RESULTS

In 17 (24%) cases MELF pattern was detected. It was more frequent in low grade tumors; it was present in four grade 3 cases. In 9 (53%) cases there was deep myometrial infiltration. Five cases had lymph node metastasis in the pelvis and three in the para-aortic region. One of the patients died, another presented a vulvar recurrence and another pulmonary metastasis.

CONCLUSION

MELF pattern can be seen in high grade EAE and correlates with deep myometrial infiltration and pelvic lymph node metastasis. Its presence does not seem to influence survival.

The Potential Roles of MELF-Pattern, Microvessel Density, and VEGF Expression in Survival of Patients with Endometrioid Endometrial Carcinoma: A Morphometrical and Immunohistochemical Analysis of 100 Cases

Background

In this study, we hypothesized that microcystic, elongated, fragmented (MELF)-pattern, vascular endothelial growth factor (VEGF) expression by cancer cells and microvessel density of cancer stroma may be associated with progression of endometrioid adenocarcinoma.

Methods

The study used data from the Belarus Cancer Registry and archival histological material of 100 patients with retrospectively known good (survival) and poor (disease progression and death) outcomes. All cases were immunohistochemically stained for CD34 and VEGF. Two independent samples were compared for the characteristics of signs, and obtained results were analyzed by receiver operating characteristic analysis, Mann-Whitney U test, χ² test (Yates correction), and Mantel-Cox test. Multivariate Cox hazard analysis and Spearman correlation test were used. A p-value of less than .05 was considered statistically significant.

Results

The observed survival rate of patients with endometrioid adenocarcinoma was significantly lower (p = .002) in MELF-pattern positive patients when compared with MELF-pattern negative patients. The overall survival rate of patients whose tumors had more than 114 vessels/mm² of tissue was significantly low (p < .001). Interestingly, a similar observation was found in patients with increased vessel area, evidenced by VEGF expression in the glandular tumor component.

Conclusions

Our study suggests, for the first time, that these criteria may be used as risk factors of endometrioid adenocarcinoma progression during 5 years after radical surgical treatment. However, a large independent cohort of samples should be considered in the future to validate our findings.

Immunohistochemical expression of galectin-3 is significantly associated with grade, stage and differentiation of endometrial carcinomas

This study describes galectin-3 immunohistochemical phenotype and its association with clinicopathological factors in the carcinoma of endometrium. Seventy one cases of endometrial carcinoma and 30 cases of benign and normal endometrium were employed for the detection of galectin-3 protein using tissue microarrays and immunohistochemistry staining. Thirty nine (55%) cases, including 54.2% of endometrioid adenocarcinomas and 55.5% serous carcinomas, were positively stained for galectin-3. Brown granular expression of this glycoprotein was detected in transformed epithelial cells of 36 cases including 28 cases with membranous and cytoplasmic staining and 8 cases with only cytoplasmic staining; nuclear expression was present in stromal cells of the remaining 3 cases. Twenty-four (80%) control cases showed granular cytoplasmic and membranous expression, and six control cases were negative. Tumor grade, stage and differentiation were significantly associated with galectin-3 immunoreactivity (p-values are 0.043, 0.016, and 0.044 respectively), cases with membranous and cytoplasmic staining is significantly associated with grade I and stage II, while cases with loss of staining are more frequent in grade II, III and poorly differentiated tumors. No significant association of galectin-3 staining was observed with age, diagnosis, recurrence and alive status. The current study supports the tumor suppression role of galectin-3 in endometrial carcinoma. Greater galectin-3 immunostaining has been found in control endometrial tissues compared to endometrial tumors. Loss or decreased galectin-3 immunoexpression gives a sign for poor prognoses in endometrial carcinoma patients.

The Microcystic, Elongated, and Fragmented (MELF) Pattern of Invasion: A Single Institution Report of 464 Consecutive FIGO Grade 1 Endometrial Endometrioid Adenocarcinomas

MELF invasion has been associated with nonvaginal recurrences and lymph node (LN) metastases in multi-institutional case control studies but has not been well examined in large single-institution cohorts. Hysterectomy specimens with FIGO 1 endometrioid endometrial carcinoma and lymphadenectomies from 2007 to 2012 were identified. Electronic medical records and histologic slides were reviewed. Of 464 identified cases, 163 (35.1%) were noninvasive, 60 (12.9%) had MELF, 222 (47.8%) had a component of the infiltrative invasion pattern without MELF, 13 (2.8%) had pure pushing borders of invasion, 5 (1.1%) had pure adenomyosis-like invasion, and 1 (0.2%) had pure adenoma malignum-like invasion. Sixteen cases had LN metastases. Significantly more MELF cases had positive LNs than non-MELF cases overall (18.3% vs. 1.2%, P<0.001). The results were almost identical when invasive infiltrative cases with and without MELF were compared (18.3% vs. 1.8%, P<0.001). The maximum number of MELF glands per slide did not differ between cases with and without LN metastases, P=0.137. A majority of positive LNs, even in MELF cases, demonstrated nonhistiocyte-like metastases. Only 5 cases (all with MELF invasion) demonstrated micrometastatic lesions or isolated tumor cells only. MELF cases demonstrated a nonsignificant decrease in time to extravaginal recurrence (P=0.082, log-rank test), for which analysis was limited by low recurrence rates. In summary, MELF is associated with LN metastases, even when compared with other infiltrative cases and shows multiple patterns of growth in positive LNs. MELF cases additionally trended toward decreased time to extravaginal recurrence.

Aberrant expression and hormonal regulation of Galectin-3 in endometriosis women with infertility

OBJECTIVE

To investigate the role and potential molecular mechanism of Galectin-3 (Gal-3) in the etiology of endometriosis-associated infertility.

METHODS

We detected Gal-3 expression in eutopic endometrium from women with endometriosis-associated infertility and healthy women without endometriosis or infertility. We then evaluated Gal-3 expression in endometrial glandular epithelial cells (EECs) and endometrial stromal cells (ESCs) and investigated its response to hormone stimulation in EECs and ESCs from both groups of women.

RESULTS

Results of real-time PCR and western blot analysis showed Gal-3 expression in both proliferative and secretory stages of the menstrual cycle decreased significantly in women with endometriosis-associated infertility compared to healthy women. The changes in expression of Gal-3 were more dramatic in EECs than ESCs. Moreover, estrogen (E2) and progesterone (P4) induced Gal-3 expression in EECs of healthy groups, and P4 was more significant than E2 and combined E2 and P4 (E2P4). However, in the endometriosis group, P4 failed to induce a similar increase in Gal-3 expression.

CONCLUSIONS

Our results suggest that aberrant expression of Gal-3 might contribute to infertility in patients with endometriosis due to progesterone resistance.

How to approach the many faces of endometrioid carcinoma

This article reviews the salient features of variants of endometrioid carcinoma (ECa) that can pose a diagnostic challenge and/or are associated with unique clinicopathological findings. Variants with distinct architectural and cytologic features include the following: (1) ECa with a villoglandular pattern (tumor with finger-like papillae lined by bland cells with a tendency for vascular/lymphatic invasion and lymph node metastasis once this pattern is seen within the myoinvasive component); (2) papillary ECa of intermediate grade (grade 2) (tumor that can be mistaken for serous carcinoma, as it contains papillae showing slightly irregular contours, moderately atypical cells, and it is associated with vascular/lymphatic invasion/lymph node metastasis, but with common association with mucinous metaplasia, MELF (microcystic, elongated, and fragmented) pattern of invasion, and wild p53 expression); (3) ECa with non-villous papillae (tumor containing pseudopapillae within glands with bland-appearing cytology commonly associated with abortive squamous differentiation and otherwise not different from usual ECa); (4) ECa with microglandular-like pattern (tumor that mimics microglandular hyperplasia of the cervix, often lacking the typical appearance of microglandular hyperplasia and showing Ki-67 index >10%, strong CD10 expression, and negative PAX-2, p63, and CD34); and (5) ECa with sex cord-like formations and hyalinization (tumor with interconnected cords and nests of bland epithelioid and spindled cells that merge with a typical component of low-grade ECa, usually associated with squamous differentiation and hyalinization). This tumor should be distinguished from carcinosarcoma and, in contrast to the latter, it shows nuclear β-catenin expression, ER/PR and patchy p16 positivity, tends to present at a low stage, and has a favorable prognosis and (6) dedifferentiated ECa (tumor showing a low-grade ECa juxtaposed to an undifferentiated carcinoma-the latter characterized by variably sized monotonous, often non-cohesive cells with brisk mitotic activity and usually arranged in sheets). Undifferentiated carcinoma tends to be negative for PAX8 and ER/PR with variable expression of keratins and can be associated with microsatellite instability (may be part of Lynch syndrome). Variants with distinct cytological features include the following: (1) ECa with clear cells (tumors with clearing due to 'clear' (glycogenated) squamous cells, distinct vacuoles, or not otherwise specified. EC with clear cells should be distinguished from clear cell carcinoma by the absence of the variety of architectural patterns, lack of cuboidal/flattened/hobnail cells, and lack of degree of atypia usually detected in clear cell carcinoma. In addition, they are ER/PR positive and Napsin A and p504S negative in contrast to clear cell carcinoma); (2) ECa with spindle cells (tumor with transition from spindle cells to the glandular component of a low-grade ECa. The spindle cells are keratin, ER/PR, and patchy p16 positive and show wild-type p53 expression); (3) ECa with mucinous differentiation (this tumor can be mistaken for a cervical adenocarcinoma, as they have overlapping features. Expression of ER/PR and vimentin in the context of a negative or patchy p16 positivity and the absence of high-risk HPV allows a correct diagnosis).

G3-C12 Peptide Reverses Galectin-3 from Foe to Friend for Active Targeting Cancer Treatment

Galectin-3 is overexpressed by numerous carcinomas and is a potential target for active tumor treatments. On the other hand, galectin-3 also plays a key role in cancer progression and prevents cells from undergoing apoptosis, thereby offsetting the benefits of active targeting drugs. However, the relative contribution of the protective antiapoptotic effects of galectin-3 and the proapoptotic effects of galectin-3-targeted therapies has remained yet unrevealed. Here, we show that a galectin-3-binding peptide G3-C12 could reverse galectin-3 from foe to friend for active targeting delivery system. Results showed G3-C12 modified N-(2-hydroxypropyl)methacrylamide copolymer doxorubicin conjugates (G3-C12-HPMA-Dox) could internalize into galectin-3 overexpressed PC-3 cells via a highly specific ligand-receptor pathway (2.2 times higher cellular internalization than HPMA-Dox). The internalized Dox stimulated the translocation of galectin-3 to the mitochondria to prevent from apoptosis. In turn, this caused G3-C12-HPMA-Dox to concentrate into the mitochondria after binding to galectin-3 intracellularly. Initially, mitochondrial galectin-3 weakened Dox-induced mitochondrial damage; however, as time progressed, G3-C12 active-mediation allowed increasing amounts of Dox to be delivered to the mitochondria, which eventually induced higher level of apoptosis than nontargeted copolymers. In addition, G3-C12 downregulates galectin-3 expression, 0.43 times lower than control cells, which could possibly be responsible for the suppressed cell migration. Thus, G3-C12 peptide exerts sequential targeting to both cell membrane and mitochondria via regulating galectin-3, and eventually reverses and overcomes the protective effects of galectin-3; therefore, it could be a promising agent for the treatment of galectin-3-overexpressing cancers.

Expression of immune checkpoint molecules in endometrial carcinoma

The main obstacle in the development of an effective tumor vaccine is the inherent ability of tumors to evade immune responses. Tumors often use common immune mechanisms and regulators to evade the immune system. The present study aimed to analyze the expression levels of indoleamine 2,3-dioxygenase (IDO), programmed death-ligand (PD-L) 1, PD-L2, B7-H4, galectin-1 and galectin-3 in tissue samples from patients with endometrial carcinoma, in order to detect the immunosuppressive environment of endometrial carcinomas. The levels of IDO, PD-L1, PD-L2 and B7-H4 were analyzed by immunohistochemical methods, and the levels of galectin-1 and galectin-3 in tumor lysates were determined using ELISA. PD-L2 was expressed at low levels in the majority of tumor samples. IDO expression was detected in 38, 63 and 43% of primary endometrial carcinoma, recurrent endometrial carcinoma, and metastatic endometrial carcinoma specimens, respectively. Positive expression rates for PD-L1 were 83% in primary endometrial carcinoma, 68% in recurrent endometrial carcinoma, and 100% in metastatic endometrial carcinoma, whereas B7-H4 expression was detected in 100% of both primary endometrial carcinoma and recurrent endometrial carcinoma samples, and in 96% of metastatic endometrial carcinoma specimens. The expression levels of galectin-1 and galectin-3 were not significantly different between the normal and tumor specimens. The results of the present study suggest that the interaction between PD-1/PD-L1 and B7-H4 may be a potential target for immune intervention in the treatment of endometrial carcinoma. Furthermore, the results may provide the basis for immunosuppressant therapy in the treatment of patients with uterine cancer.

Galectins: Double-edged Swords in the Cross-roads of Pregnancy Complications and Female Reproductive Tract Inflammation and Neoplasia

Galectins are an evolutionarily ancient and widely expressed family of lectins that have unique glycan-binding characteristics. They are pleiotropic regulators of key biological processes, such as cell growth, proliferation, differentiation, apoptosis, signal transduction, and pre-mRNA splicing, as well as homo- and heterotypic cell-cell and cell-extracellular matrix interactions. Galectins are also pivotal in immune responses since they regulate host-pathogen interactions, innate and adaptive immune responses, acute and chronic inflammation, and immune tolerance. Some galectins are also central to the regulation of angiogenesis, cell migration and invasion. Expression and functional data provide convincing evidence that, due to these functions, galectins play key roles in shared and unique pathways of normal embryonic and placental development as well as oncodevelopmental processes in tumorigenesis. Therefore, galectins may sometimes act as double-edged swords since they have beneficial but also harmful effects for the organism. Recent advances facilitate the use of galectins as biomarkers in obstetrical syndromes and in various malignancies, and their therapeutic applications are also under investigation. This review provides a general overview of galectins and a focused review of this lectin subfamily in the context of inflammation, infection and tumors of the female reproductive tract as well as in normal pregnancies and those complicated by the great obstetrical syndromes.

Histological features associated with occult lymph node metastasis in FIGO clinical stage I, grade I endometrioid carcinoma

AIMS

Lymph node involvement affects prognosis/treatment in endometrial carcinoma patients. We assessed various histological features associated with nodal metastasis in patients with grade I, stage I endometrial endometrioid carcinoma (EEC).

METHODS AND RESULTS

Eighteen stage I EECs with occult positive lymph nodes and 36 controls were assessed for depth of myoinvasion; microcystic, elongated and fragmented (MELF) pattern of myometrial invasion; lymphovascular invasion (LVI); and epithelial metaplasia. Nodal metastases were subclassified as isolated tumour cells (ITCs; ≤0.2 mm), micrometastasis (>0.2 mm and <2 mm), or macrometastasis (≥2 mm). Node-positive cases had significantly higher rates of LVI (P < 0.001) and MELF invasion (P = 0.003) on univariate analysis. Only LVI was associated significantly with nodal metastasis on multivariate analysis (P = 0.002). Tumours with MELF invasion demonstrated reduced E-cadherin expression. Macrometastases were identified in seven cases (39%) with or without micrometastasis/ITCs. Eight (44%) contained only ITCs. Eleven (61%) had histiocyte-like nodal metastases. Biopsy material from four of six (67%) and five of 17 (29%) cases with and without nodal metastasis showed detached eosinophilic tumour cell buds. Of the former, three were associated with histiocyte-like nodal metastases - a feature absent in biopsies without tumour budding.

CONCLUSIONS

Lymph nodes from grade I EEC exhibiting cellular budding or LVI should be examined for occult metastases, especially in the form of histiocyte-like cells.

Epithelial-mesenchymal transition in carcinomas of the female genital tract

Invasion is a defining feature of malignancy, but the mechanisms of invasion in many common cancers, including gynaecological malignancies, remain unclear. However, it has been proposed that malignant cells may usurp a normal embryological process, epithelial-mesenchymal transition (EMT), as a means of acquiring migratory capacity. The synergistic role of the tumour microenvironment in EMT induction has also been explored and helps to explain the spatially restricted distribution of EMT at the deep tumour margin (invasive front). Furthermore, tumour cells undergoing EMT may acquire cancer stem cell characteristics, and this may be relevant to the entire metastatic process and to tumour recurrence and treatment failure. Nevertheless, doubts persist regarding the role of EMT in malignant progression in vivo, partly because few studies have correlated molecular and histological alterations in clinical pathology specimens. In the current review we summarize the evidence for EMT in the common gynaecological epithelial malignancies, and discuss the morphological and immunohistochemical changes occurring at the invasive tumour front that may represent EMT-like processes. The possibility that carcinosarcomas represent a variant type of EMT with 'fixed' mesenchymal differentiation is also considered. Diagnostic histopathologists are ideally placed to critically evaluate the role of EMT in gynaecological and other types of malignancy.

Patterns of myoinvasion in endometrial adenocarcinoma: recognition and implications

Endometrial endometrioid adenocarcinoma (EEC) is the most common malignancy of the female genital tract, partly attributable to chronic estrogen exposure secondary to increased obesity rates. Tumor stage, which in most cases is based on depth of invasion (DOI), is of critical importance in determining if additional treatment is needed. However, the array of invasive morphologies within the spectrum of ECC can make the determination of DOI difficult. Several morphologic patterns of invasion have been described, including diffusely infiltrating irregular glands, "broad front" (or pushing border), adenoma malignum, adenomyosis-like, and microcystic, elongated, and fragmented glands. EEC may often contain a mixture of invasive patterns, which can further complicate evaluation of these common tumors. Recognition of these patterns may lead to more accurate staging, but perhaps more importantly, some patterns may be associated with adverse prognostic features. The purpose of this review is to highlight the various invasive patterns of EEC and note their unique pitfalls and prognostic implications in an effort to improve staging accuracy and treatment and follow-up for the thousands of women affected by this disease each year.