Immunoexpression of PAX 8 in Endometrial Cancer: Relation to High-Grade Carcinoma and p53

Single-nuclei sequencing of uterine serous carcinoma reveals racial differences in immune signaling

Significant racial disparities exist between Black and White patients with uterine serous carcinoma (USC). While the reasons for these disparities are unclear, several studies have demonstrated significantly different rates of driver mutations between racial groups, including TP53. However, limited research has investigated the transcriptional differences of tumors or the composition of the tumor microenvironment (TME) between these groups. Here, we report the single-nuclei RNA-sequencing profiles of primary USC tumors from diverse racial backgrounds. We find that there are significant differences between the tumors of Black and White patients. Tumors from Black patients exhibited higher expression of specific genes associated with aggressiveness, such as PAX8, and axon guidance and synaptic signaling pathways. We also demonstrated that T cell populations are reduced in the tumor tissue compared to matched benign, while anti-inflammatory macrophage populations are retained within the TME. Furthermore, we investigated the connection between PAX8 overexpression and immunosuppression in USC through regulation of several cytokines and chemokines. Notably, we show that PAX8 activity can influence macrophage gene expression and protein secretion. These studies provide a detailed understanding of the USC transcriptome and TME, and identify differences in tumor biology from patients of different racial backgrounds.

Pax-8: Molecular biology, pathophysiology, and potential pathogenesis

Transcription factors, as the convergence points of multiple signaling pathways in eukaryotic cells, are closely involved in disease development. Pax-8, an important transcription factor belonging to the Pax family, exerts a crucial influence on the regulation of gene expression required for both physiological conditions and pathological processes. Pax-8 contributes to the pathogenesis of many human diseases, ranging from cardiovascular disease to many cancers, and therefore, it can be imagined that Pax-8 holds great therapeutic potential. In this review, we summarize the structure, distribution, function, and regulatory mechanisms of Pax-8 to provide a new research direction for Pax-8.

Evaluation of Lineage/Site-specific Nuclear Immunohistochemical Markers SATB2, Cyclin D1, SALL4, and BCOR in High-grade Endometrial Carcinomas

Poorly differentiated malignant neoplasms involving the gynecologic tract routinely include a poorly differentiated endometrial carcinoma (EC) in the differential diagnosis. Some nuclear lineage/site-specific immunohistochemical markers are utilized in this diagnostic setting including SATB2, cyclin D1, SALL4, and BCOR, but their specificity and use in small samples are not clear across the spectrum of ECs. Cases of undifferentiated/dedifferentiated endometrial carcinomas (UEC/DDEC), clear cell carcinoma (CCC), uterine serous carcinoma (USC), FIGO grade 3 endometrial endometrioid carcinoma (EEC), and uterine carcinosarcoma (UCS) were identified and diagnoses confirmed. Whole-section immunohistochemical stains for SATB2, cyclin D1, SALL4, BCOR, and PAX8 were performed. A total of 113 cases were utilized: 15 CCC, 26 EEC, 19 UCS, 22 USC, and 31 UEC/DDEC. Cases were distributed across both low (49%) and high (51%) FIGO clinical stages. SATB2 was expressed by UCS (8/19, 42%), EEC (10/26, 38%), UEC/DDEC (11/30, 37%), and USC (6/22, 27%). Cyclin D1 was expressed by EEC (24/26, 92%), USC (17/22, 77%), UEC/DDEC (15/20 EEC component, 75%; 22/30 UEC, 73%), UCS (10/16 carcinoma, 63%; 11/19 sarcoma, 58%), and CCC (8/15, 53%). SALL4 was expressed most frequently by UEC/DDEC (12/30, 40%), but also USC (7/22, 32%), EEC (5/26, 19%), and UCS (4/16 carcinoma, 25%; 3/19 sarcoma, 16%). BCOR was expressed at low levels in 2 USC, 2 UEC/DDEC, and 2 UCS. PAX8 was generally positive but showed lower expression in UEC/DDEC (17/30, 57%) and in the sarcomatous portions of UCS (6/19, 32%). SATB2, cyclin D1, SALL4, and BCOR stain variable numbers of poorly-differentiated EC and must be carefully interpreted within morphologic and clinical context.

SOX17: A Highly Sensitive and Specific Immunomarker for Ovarian and Endometrial Carcinomas

PAX8 is the most commonly used immunomarker to link a carcinoma to the gynecologic tract; however, it lacks specificity. Through mining The Cancer Genome Atlas mRNA expression profile data, we identified SOX17 as a potential specific marker at the mRNA level for gynecologic tumors. To evaluate the utility of this marker in the identification of the gynecologic origin of a given carcinoma, we performed immunochemical staining in a large cohort of ovarian and endometrial cancer cases (n = 416), together with a large cohort of solid tumors from other organs (n = 1544) in tissue microarrays. Similar to PAX8, SOX17 was highly expressed in different subtypes of ovarian carcinoma (97.5% for SOX17 vs 97% for PAX8 in serous carcinoma, 90% vs 90% in endometrioid carcinoma, and 100% vs 100% in clear cell carcinoma), except for mucinous carcinoma (0% vs 27%), and was also highly expressed in different subtypes of endometrial carcinoma (88% vs 84% in endometrioid carcinoma, 100% vs 100% in serous and clear cell carcinoma). SOX17 was not expressed in thyroid and renal cell carcinomas, whereas PAX8 expression was high (86% and 85%, respectively). In addition, SOX17 was expressed at low levels in cervical adenocarcinoma (20%) and had no expression in cervical squamous carcinoma, mesothelioma, and carcinomas from the breast, lung, pancreas, colon, stomach, liver, bladder, and salivary gland. Our data indicate that SOX17 is not only a sensitive but also a specific marker for the origin of ovarian and endometrial carcinomas.

Paired-Box Gene 8 (PAX8) and Its Association With Epithelial Carcinomas

Cancer is the second most common culprit of mortality in the United States and epithelial carcinomas are considered as one of the most predominant types of cancer. The association between epithelial cancers and paired-box gene 8 (PAX8) has been studied significantly before. PAX8 belongs to the paired-box gene family, which plays an important role in the organogenesis of different body organ systems, especially the thyroid gland, the renal system, and the Müllerian system. Immunohistochemical staining is being used to detect PAX8 expression in different epithelial cancers and differentiate them from PAX8-negative tumors. In follicular, papillary, and anaplastic thyroid carcinomas, targeting the PAX8/peroxisome proliferator-activated receptors (PPARs) fusion protein is being considered as a potential mechanism for therapy. Moreover, because of its high expression in primary ovarian cancers, PAX8 is being considered as a target for ovarian cancer treatment as well. More studies are needed to test the possibility of using PAX8 as a possible target for managing endometrial carcinomas. In this article, we review the functions of the PAX8 gene, how its mutations lead to the development of certain epithelial carcinomas, how it can be used as a diagnostic or a prognostic marker, and its potential as a therapeutic target for these cancers.

Duodenal recurrence of endometrial carcinoma: report of a rare metastatic site

Endometrial carcinoma is one of the most common gynaecologic malignancies in the western society. Treatment of recurrent disease became more refined, with the study of molecular and hormonal receptors playing a central role. A 76-year-old caucasian woman presented to the emergency department with growing tiredness, and melaena. Past medical history included an endometrioid adenocarcinoma. The patient had undergone a hysterectomy with bilateral salpingo-oophorectomy with pelvic and paraaortic lymphadenectomy and was disease-free for 2 years. The endoscopy revealed an ulcerated lesion involving the second and third portions of the duodenum. Histopathologic examination confirmed a poorly differentiated adenocarcinoma of endometrial origin. She started palliative chemotherapy, remaining with adequate symptomatic control. Endometrial cancer recurrence typically occurs locally. The liver is the intra-abdominal organ most commonly involved. There are scarce reports of duodenal metastasis of malignancies originated in distant organs. The duodenum remains an uncommon metastization site and is rarely associated with endometrial cancer.

Immunohistochemical expression of PAX-8 in Sudanese patients diagnosed with malignant female reproductive tract tumors

Objectives

Paired box protein-8 (PAX-8) immunohistochemical expression can be used as a diagnostic marker for epithelial cells tumors. This study aimed at investigating the immunohistochemical expression of PAX-8 among Sudanese females diagnosed with cervical, endometrial, and ovarian cancers between December 2017 and May 2019 by studying their Formalin-fixed paraffin embedded blocks.

Results

Sixty patients diagnosed with female reproductive tract cancers were included who aged 58.7 ± 6.9 years (range, 43—71). Cervix was the most common cancer site in 51/60 (85%) patients. Regarding cancer stage, there was 17 (28%) and 14 (23%) of the study population had stage 3B and 2B, respectively. The histopathological diagnosis included 20 (44%), 13 (29%), and 12 (27%) poorly, moderately, and well differentiated cervical squamous cell carcinoma (SCC) as well as 11 (73%), 2 (13%), 1 (7%), and 1 (7%) endometrial adenocarcinoma, metastatic adenocarcinoma, endocervical adenocarcinoma, and ovarian mucinous cyst adenocarcinoma, respectively. PAX-8 was positively expressed in 9 endometrial adenocarcinoma, 1 endocervical adenocarcinoma and 1 ovarian mucinous cyst adenocarcinoma, 2 poorly, and 1 moderately differentiated SCC. All patients diagnosed with well differentiated SCC and metastatic adenocarcinoma showed no expression of PAX-8. A statistically significant was seen for PAX-8 expression and the different histopathological diagnosis, P value < 0.001.

RNA-seq analysis identifies key long non-coding RNAs connected to the pathogenesis of alcohol-associated head and neck squamous cell carcinoma

Alcohol consumption has been implicated in the pathogenesis of head and neck squamous cell carcinoma (HNSCC), although its mechanism is poorly understood. Recent advances in the identification and understanding of long non-coding RNAs (lncRNAs) have indicated that these molecules have a profound effect on numerous biological processes, including tumorigenesis and oncogenesis. The present authors hypothesize that alcohol-mediated dysregulation of lncRNAs is a key event in HNSCC pathogenesis. An in silico differential expression analysis utilizing RNA sequencing (RNA-seq) data from 34 HNSCC patients, which included alcohol drinkers and non-alcohol drinkers, identified a panel of lncRNAs that were dysregulated due to alcohol consumption. Normal oral keratinocytes were then exposed to ethanol and acetaldehyde to validate the RNA-seq results. Two lncRNAs that were differentially expressed due to alcohol consumption were identified from RNA-seq analysis of the clinical data: lnc-PSD4-1 and lnc-NETO-1. Oral keratinocytes exposed to alcohol and acetaldehyde demonstrated dysregulation of these two lncRNAs, thus validating the results of RNA-seq analysis. In addition, low expression of the lnc-PSD4-1 isoform, lnc-PSD4-1:14, exhibited a strong correlation with high survival rates in a Cox proportional hazards regression model. Therefore, these lncRNAs may play a key role in the early pathogenesis of HNSCC, since they are dysregulated in both clinical data and in vitro experiments mimicking the effects of alcohol use.

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).

Defective DNA Mismatch Repair Influences Expression of Endometrial Carcinoma Biomarkers

Endometrial endometrioid carcinomas are related to estrogen excess and express estrogen and progesterone receptors. However, hormone receptor expression can be variable from tumor to tumor, and this variability is not always explained by differences in tumor grade. Variable expression of other biomarkers that may be used in the diagnostic work-up of endometrial cancer has also been noted. We hypothesized that mismatch repair (MMR) defects may contribute to this variability. A total of 411 unselected endometrial carcinomas were evaluated for immunohistochemical expression of DNA MMR proteins and MLH1 methylation. Loss of immunohistochemical expression of MLH1, MSH2, MSH6, or PMS2 was defined as MMR deficient; positive expression was defined as MMR intact. A case-control cohort of 80 Grade 2 endometrioid carcinomas was selected from this set (40 MMR deficient, 40 MMR intact). Cases were matched for histotype, grade, and age. Estrogen receptor, progesterone receptor, CK7(+), CK20, and Pax-8 immunohistochemistry was evaluated. The median percentage of CK7 tumor cells was significantly lower in the MMR deficient group compared with the MMR intact group. The mean percentage of tumor cells exhibiting estrogen receptor expression was similar in both the MMR-deficient and MMR intact groups. However, there was greater variability in the MMR-deficient group. Our study shows that MMR defects influence the expression of clinically important biomarkers for endometrioid-type endometrial carcinoma as decreased cytokeratin 7 expression is more commonly associated with MMR deficiency.

GATA3 Is a Sensitive and Specific Marker of Benign and Malignant Mesonephric Lesions in the Lower Female Genital Tract

GATA3 is a transcription factor critical for embryogenesis, development, and cell differentiation. Recent studies have suggested that GATA3 is a sensitive and relatively specific biomarker for urothelial and breast carcinomas, with most Müllerian carcinomas being negative. We investigated GATA3 expression in mesonephric/Wolffian remnants and tumors in the female genital tract. A western blot was performed to assess specificity for the GATA3 antibody. GATA3 immunohistochemistry was performed on 59 formalin-fixed paraffin-embedded mesonephric samples, including 17 mesonephric remnants (MR; 11 cervical and 6 fallopian tube), 15 mesonephric hyperplasias, 21 mesonephric carcinomas, and 6 female adnexal tumors of probable Wolffian origin. Thirty conventional endocervical adenocarcinomas (ENDO-CA), 9 gastric-type cervical adenocarcinomas, and 165 endometrial adenocarcinomas (EM-CA) were also evaluated. GATA3 nuclear intensity and extent of staining was evaluated. The western blot revealed GATA3 expression in seminal vesicle and cell lines derived from breast and urothelial carcinomas, but not in other cell lines including ovarian, cervical, and endometrial cancers. All cervical MRs and mesonephric hyperplasias, 5/6 (83%) fallopian tube MRs, and 20/21 (95%) mesonephric carcinomas were GATA3 positive, although with great variability in both intensity (weak to strong) and extent (1+ to 3+) of staining. Only 1/6 (17%) female adnexal tumors of probable Wolffian origin showed weak multifocal staining. One of 30 (3%) usual-type ENDO-CAs and 3/165 EM-CAs exhibited weak-moderate GATA3 immunoreactivity; all gastric-type cervical adenocarcinomas were negative. GATA3 is a highly sensitive and specific marker for mesonephric lesions in the lower genital tract; however, its utility in the upper genital tract may be more limited. In addition, GATA3 can aid in distinguishing lower genital mesonephric lesions from usual-type and gastric-type ENDO-CAs and uterine EM-CAs.

Unusual Presentation of Recurrent Early Stage Endometrial Carcinoma 28 Years after Primary Surgery

Endometrial carcinoma is the most common neoplasia of female genital tract. The prognosis of early stage disease (FIGO I and FIGO II) is excellent: recurrence after surgery is less than 15%, most of which are reported within 3 years after primary treatment. Herein we report a case of late rectal recurrence from FIGO Ib endometrial adenocarcinoma. Patient had also familiar and personal history of colonic adenocarcinoma and previous findings of microsatellite instability (MSI); molecular analysis evidenced heterozygotic somatic mutation in MLH1 gene. Twenty-eight years after hysterectomy and bilateral salpingoovariectomy, a rectal wall mass was detected during routine colonoscopy. Patients underwent CT scan, pelvic MRI, and rectal EUS with FNA: histopathological and immunohistochemical analysis revealed differentiated carcinoma cells of endometrial origin. No neoadjuvant treatment was planned and low rectal anterior resection with protective colostomy was performed; histology confirmed rectal lesion as metastasis from endometrial carcinoma. Recurrence of early stage endometrial carcinoma after a long period from primary surgery is possible. It is important to keep in mind this possibility in order to set a correct diagnostic and therapeutic algorithm, including preoperative immunohistochemical staining, and to plan a prolonged follow-up program.

Differential patterns of PAX8, p16, and ER immunostains in mesonephric lesions and adenocarcinomas of the cervix

Mesonephric remnants, usually located deep in the lateral cervical wall, may become hyperplastic resulting in a florid proliferation. These can be misinterpreted as malignant and confused with endocervical adenocarcinomas. Recent data have shown that PAX2 is diffusely expressed in mesonephric remnants and hyperplasias. PAX8 is a related transcription protein that is expressed in tissues of müllerian and wolffian origin. In this study, we have investigated the utility of an immunohistochemical panel comprising of PAX8, estrogen receptor (ER), and p16 in the differential diagnosis between mesonephric proliferations and cervical adenocarcinomas. A database search was conducted for cases of mesonephric remnants/hyperplasia/carcinoma of cervix and invasive cervical adenocarcinomas. Immunohistochemical stains for PAX8, ER, and p16 were performed using the avidin-biotin peroxidase technique on the most representative tissue. The search yielded 28 cases of mesonephric proliferations of cervix (15 mesonephric remnants, 12 mesonephric hyperplasias, and 1 mesonephric adenocarcinoma) and 16 cases of cervical adenocarcinomas (15 usual type and 1 adenoma malignum). Immunohistochemically, all the mesonephric proliferations, regardless of being benign or malignant, displayed a consistent staining pattern-diffusely and strongly positive for PAX8, negative for ER, and patchy cytoplasmic staining for p16. The usual type cervical adenocarcinomas exhibited a variable staining pattern with PAX8 and ER but all were strongly and diffusely positive for p16. The case of adenoma malignum was PAX8 positive, ER negative, and showed weak and patchy staining with p16. Our study suggests that a panel of immunohistochemical stains composed of PAX8, p16, and ER is useful in the distinction between mesonephric proliferations and cervical adenocarcinomas.

PAX8 expression in uterine adenocarcinomas and mesonephric proliferations

PAX8 is a useful immunohistochemical marker for the diagnosis of gynecologic tract malignancies. Several studies have described PAX8 expression in a wide variety of epithelial neoplasms, including ovarian and endometrial carcinomas. The goal of this study was to evaluate PAX8 expression in various types of uterine adenocarcinomas and mesonephric proliferations. Ninety-four cases of uterine adenocarcinomas (52 endometrial endometrioid carcinomas, 21 endometrial serous carcinomas, and 21 human papillomavirus-related endocervical carcinomas), 11 cases of benign mesonephric proliferations (remnants/hyperplasia), and normal endometrial and endocervical glandular epithelium in 58 cases were studied. Immunohistochemical staining was performed with the rabbit polyclonal anti-PAX8 antibody. All adenocarcinoma groups demonstrated a high frequency of PAX8 expression but with relatively high variability in the extent of staining among different subtypes. Both serous carcinomas and endometrioid carcinomas were positive in most cases (95% and 96%, respectively), but serous carcinomas displayed a significantly higher level of expression (immunohistochemical composite scores based on combined extent and intensity of expression) compared with endometrioid carcinomas (mean immunohistochemical composite scores: 8.3 vs. 5.3, respectively; P<0.006). Endocervical adenocarcinomas also had a high frequency of PAX8 expression (86% of cases), but the level of expression was significantly less than that of endometrial adenocarcinomas (mean immunohistochemical composite scores: 2.9 vs. 5.3-8.3, respectively; P<0.004). Among benign glandular epithelia, normal endocervical glands exhibited a significantly lower level of expression compared with either normal endometrial glands or benign mesonephric proliferations (mean immunohistochemical composite scores: 2.6 vs. 6.6-11.2, respectively; P<0.0006). We conclude that PAX8 is expressed in the vast majority of uterine adenocarcinomas, including those of both endometrial and endocervical origin, and that the level of expression based on combined extent and intensity is highest in endometrial serous carcinoma and lowest in endocervical adenocarcinoma. However, the high prevalence of PAX8 expression in the various types of uterine adenocarcinomas precludes use of this marker for distinguishing these tumors. In extrauterine sites, PAX8 can serve as a useful marker for adenocarcinomas of uterine origin (also positive in the majority of ovarian carcinomas), being most sensitive for identification of endometrial adenocarcinomas (both serous and endometrioid). The sensitivity for identifying metastatic endocervical adenocarcinomas is likely less and dependent on the degree to which the significantly lower extent of expression in these tumors is maintained in metastatic sites.

Reliability of PAX8 in clinical practice to accurately determine primary site of origin in female pelvic or abdominal lesions

Female patients with gynecological malignancies can harbor peritoneal pelvic or abdominal lesions; however, other primary tumors can involve the peritoneum as well. Since sampling of the peritoneum now can be easily performed by fine needle aspiration or percutaneous biopsy, we have noticed an increase in such procedures as initial attempts to establish a diagnosis. PAX8 has been used alone or in combination with other tumor markers to accurately classify these lesions and determine primary site of origin; however, prior published studies determined expression of PAX8 within historically diagnosed cases. We reviewed the reliability of PAX8 to determine tumor type or primary site in 135 current clinical pelvic or abdominal lesions and highlight several pitfalls in its routine use, in particular, relying on the presumed expression pattern (positive or negative) within a given primary tumor and that poorly differentiated endometrial endometrioid carcinomas or undifferentiated carcinomas may have patchy PAX8 expression or even lose expression within the primary tumor or the metastasis.

Long non coding RNAs (lncRNAs) are dysregulated in Malignant Pleural Mesothelioma (MPM)

Malignant Pleural Mesothelioma (MPM) is an aggressive cancer that is often diagnosed at an advanced stage and is characterized by a long latency period (20–40 years between initial exposure and diagnosis) and prior exposure to asbestos. Currently accurate diagnosis of MPM is difficult due to the lack of sensitive biomarkers and despite minor improvements in treatment, median survival rates do not exceed 12 months. Accumulating evidence suggests that aberrant expression of long non-coding RNAs (lncRNAs) play an important functional role in cancer biology. LncRNAs are a class of recently discovered non-protein coding RNAs >200 nucleotides in length with a role in regulating transcription. Here we used NCode long noncoding microarrays to identify differentially expressed lncRNAs potentially involved in MPM pathogenesis. High priority candidate lncRNAs were selected on the basis of statistical (P<0.05) and biological significance (>3-fold difference). Expression levels of 9 candidate lncRNAs were technically validated using RT-qPCR, and biologically validated in three independent test sets: (1) 57 archived MPM tissues obtained from extrapleural pneumonectomy patients, (2) 15 cryopreserved MPM and 3 benign pleura, and (3) an extended panel of 10 MPM cell lines. RT-qPCR analysis demonstrated consistent up-regulation of these lncRNAs in independent datasets. ROC curve analysis showed that two candidates were able to separate benign pleura and MPM with high sensitivity and specificity, and were associated with nodal metastases and survival following induction chemotherapy. These results suggest that lncRNAs have potential to serve as biomarkers in MPM.

Detection of PAX8 and p53 is beneficial in recognizing metastatic carcinomas in pelvic washings, especially in cases with suspicious cytology

OBJECTIVE

The aim of this study is to evaluate the detection of paired box gene 8 (PAX8) and p53 with immunohistochemistry in pelvic washing cell block sections.

METHODS

A total of 92 cases were used in this study, which were assigned to three groups according to the cytopathology files. The first group with positive cytology including endometrial and ovarian carcinomas comprised 32 cases. The second group with suspicious cytology for endometrial or ovarian carcinomas consisted of 29 cases. The third group with negative cytology (regarded as mesothelial cells) included 31 cases. The pelvic washing cell blocks underwent immunohistochemistry to detect PAX8 and p53 expression.

RESULTS

Immunoreactivity for PAX8 was found in 75% (24/32) of the cases in the group with positive cytology, in 6.9% (2/29) of the cases with suspicious cytology, and in none of the 31 cases with negative cytology (sensitivity: 75%; specificity: 100%; p<0.05). p53 expression was detected in 37.5% (12/32) of the cases in the first group, in 3.4% (1/29) of the cases in the second group, and in none of the cases in the third group (sensitivity: 37.5%; specificity: 100%; p<0.05). Moreover, the combined expression of PAX8 and p53 showed the same result as the single expression of p53 in the three groups.

CONCLUSION

The detection of PAX8 and p53 is beneficial in recognizing metastatic carcinomas in pelvic washings, especially in cases with suspicious cytology, which additionally supports the Müllerian origin of these carcinomas.

Pair-Box (PAX8) protein-positive expression is associated with poor disease outcome in women with endometrial cancer

BACKGROUND

The Pax8 transcription factor genes have a role in cell differentiation and cell growth, and silencing of Pax8 in cell cultures results in cell death. The aims of this study were to determine the expression and correlation of Pax8 protein with several clinicopathological variables in patients with endometrial cancer.

METHODS

The following clinical parameters from 229 patients were used for correlation with Pax8 expression; age, histological subtype, myometrial depth of invasion, lymphovascular invasion (LVI), the International Federation of Gynecology and Obstetrics grade, lymph nodes status, and disease status.

RESULTS

A positive association of Pax8(+) expression was found with high tumour grade (P=0.002), LVI+(P=0.0186), and type II tumour subtype (P<0.0001) in univariate analysis. Survival analysis showed an association of Pax8 and 5-year overall survival probability (P=0.01486), 80.04% for patients with Pax8(-) and 55.59% for patients with Pax8(+). There was also an association of Pax8 and 5-year disease-free survival probability (P=0.02028), 72.12% for patients with Pax8(-) vs 49.88% for patients with Pax8(+). Finally, an association of Pax8(+) and shorter recurrence-free survival was also found (P=0.00203), with 74.36% for Pax8(-) and 52.11% for Pax8(+).

CONCLUSION

Overexpression of Pax8 protein by endometrial cancer is associated with poor disease outcomes. Inhibition of Pax8 may be a very attractive targeted therapy for selective patients.

Value of PAX 8 immunostaining in tumor diagnosis: a review and update

PAX 8 is a transcription factor involved in the regulation of organogenesis of the thyroid gland, kidney, and Müllerian system. Recent studies have shown that, among tumors, PAX 8 is commonly expressed in epithelial tumors of the thyroid and parathyroid glands, kidney, thymus, and female genital tract. Although PAX 8 expression has also been reported in certain neuroendocrine tumors, including well-differentiated pancreatic neuroendocrine tumors, and duodenal and rectal carcinoids, as well as in B-cell lymphomas, it has recently been shown that the PAX 8 positivity reported in these tumors was due to a cross-reactivity of the antibody used with the N-terminal region of PAX 6 and PAX 5, respectively. Owing to its restricted expression, PAX 8 has proved to be a useful immunohistochemical marker with a wide range of diagnostic applications in surgical pathology, some of which are briefly reviewed.

Expression pattern of PAX2 in hyperplastic and malignant endometrium

BACKGROUND

PAX2 is a member of paired box gene family and expressed during development of urogenital system. This study aimed to evaluate PAX2 expression pattern in hyperplastic and malignant endometrial tissues in comparison to non-pathological endometrial changes and to investigate the presence of any correlation between the PAX2 expression and tumor behavior.

METHODS

The study was performed on the archival material of 121 endometrial tissues including complex hyperplasia (n = 18), complex atypical hyperplasia (n = 20), and endometrioid type adenocarcinoma (n = 47) as study groups, and proliferative endometrium (n = 21) and atrophic endometrium (n = 16) as control groups. One representative block for each case was selected for immunohistochemical evaluation. Sections with 4μm thickness were cut from the blocks and incubated with PAX2 rabbit anti-human polyclonal antibody.

RESULTS

PAX2 nuclear staining was detected in all of the endometrial tissues. The mean percentages of PAX2 staining cells were 80.8, 96.7, 88.6, 92.7, and 99.2% with proliferative endometrium, atrophic endometrium, complex hyperplasia, complex atypical hyperplasia, and adenocarcinoma, respectively (Kruskal-Wallis; P < 0.001). The frequency of PAX2 staining increased as the pathology progressed in the manner of complex hyperplasia → complex atypical hyperplasia → adenocarcinoma. In cancer cases, there was no correlation between PAX2 expression levels and the stage, histological grade, myometrial invasion, and lymph node status.

CONCLUSIONS

PAX2 is expressed in hyperplastic and malignant endometrium as well as proliferative and atrophic endometrium. As the neoplastic lesion progresses from a premalignant state to endometrial cancer, PAX2 expression increases. These findings suggest that PAX2 may contribute to the development of endometrial cancer.