Insulin Modulates Myogenesis and Muscle Atrophy Resulting From Skin Scald Burn in Young Male Rats.

BACKGROUND: Burn injuries (BIs) due to scalding are one of the most common accidents among children. BIs greater than 40% of total body surface area are considered extensive and result in local and systemic response. We sought to assess morphological and myogenic mechanisms through both short- and long-term intensive insulin therapies that affect the skeletal muscle after extensive skin BI in young rats. MATERIALS AND METHODS: Wistar rats aged 21 d were distributed into four groups: control (C), control with insulin (C + I), scald burn injury (SI), and SI with insulin (SI + I). The SI groups were submitted to a 45% total body surface area burn, and the C + I and SI + I groups received insulin (5 UI/Kg/d) for 4 or 14 d. Glucose tolerance and the homeostatic model assessment of insulin resistance index were determined. Gastrocnemius muscles were analyzed for histopathological, morphometric, and immunohistochemical myogenic parameters (Pax7, MyoD, and MyoG); in addition, the expression of genes related to muscle atrophy (MuRF1 and MAFbx) and its regulation (IGF-1) were also assessed. RESULTS: Short-term treatment with insulin favored muscle regeneration by primary myogenesis and decreased muscle atrophy in animals with BIs, whereas the long-term treatment modulated myogenesis by increasing the MyoD protein. Both treatments improved histopathological parameters and secondary myogenesis by increasing the MyoG protein. CONCLUSIONS: Treatment with insulin benefits myogenic parameters during regeneration and modulates MuRF1, an important mediator of muscle atrophy.

Immunohistochemical detection of PAX-FOXO1 fusion proteins in alveolar rhabdomyosarcoma using breakpoint specific monoclonal antibodies.

Alveolar Rhabdomyosarcoma (ARMS) is an aggressive pediatric cancer with about 80% of cases characterized by either a t(1;13)(p36;q14) or t(2;13)(q35;q14), which results in the formation of the fusion oncogenes PAX7-FOXO1 and PAX3-FOXO1, respectively. Since patients with fusion-positive ARMS (FP-RMS) have a poor prognosis and are treated with an aggressive therapeutic regimen, correct classification is of clinical importance. Detection of the translocation by different molecular methods is used for diagnostics, including fluorescence in situ hybridization and RT-PCR or NGS based approaches. Since these methods are complex and time consuming, we developed specific monoclonal antibodies (mAbs) directed to the junction region on the PAX3-FOXO1 fusion protein. Two mAbs, PFM.1 and PFM.2, were developed and able to immunoprecipitate in vitro-translated PAX3-FOXO1 and cellular PAX3-FOXO1 from FP-RMS cells. Furthermore, the mAbs recognized a 105 kDa band in PAX3-FOXO1-transfected cells and in FP-RMS cell lines. The mAbs did not recognize proteins in fusion-negative embryonal rhabdomyosarcoma cell lines, nor did they recognize PAX3 or FOXO1 alone when compared to anti-PAX3 and anti-FOXO1 antibodies. We next evaluated the ability of mAb PFM.2 to detect the fusion protein by immunohistochemistry. Both PAX3-FOXO1 and PAX7-FOXO1 were detected in HEK293 cells transfected with the corresponding cDNAs. Subsequently, we stained 26 primary tumor sections and a rhabdomyosarcoma tissue array and detected both fusion proteins with a positive predictive value of 100%, negative predictive value of 98%, specificity of 100% and a sensitivity of 91%. While tumors are stained homogenously in PAX3-FOXO1 cases, the staining pattern is heterogenous with scattered positive cells only in tumors expressing PAX7-FOXO1. No staining was observed in stromal cells, embryonal rhabdomyosarcoma, and fusion-negative rhabdomyosarcoma. These results demonstrate that mAbs specific for the chimeric oncoproteins PAX3-FOXO1 and PAX7-FOXO1 can be used efficiently for simple and fast subclassification of rhabdomyosarcoma in routine diagnostics via immunohistochemical detection.

Hypermethylated ZNF582 and PAX1 genes in mouth rinse samples as biomarkers for oral dysplasia and oral cancer detection.

BACKGROUND: Effective biomarkers for oral cancer screening are important for early diagnosis and treatment of oral cancer. METHODS: Oral epithelial cell samples collected by mouth rinse were obtained from 65 normal control subjects, 108 patients with oral potentially malignant disorders, and 94 patients with oral squamous cell carcinoma (OSCC). Methylation levels of zinc-finger protein 582 (ZNF582) and paired-box 1 (PAX1) genes were quantified by real-time methylation-specific polymerase chain reaction after bisulfite conversion. RESULTS: An abrupt increase in methylated ZNF582 (ZNF582m ) and PAX1 (PAX1m ) levels and positive rates from mild dysplasia to moderate/severe dysplasia, indicating that both ZNF582m and PAX1m are effective biomarkers for differentiating moderate dysplasia or worse (MODY+) oral lesions. When ZNF582m /PAX1m tests were used for identifying MODY+ oral lesions, the sensitivity, specificity, and odds ratio (OR) were 0.65/0.64, 0.75/0.82, and 5.6/8.0, respectively. CONCLUSION: Hypermethylated ZNF582 and PAX1 genes in oral epithelial cells collected by mouth rinse are effective biomarkers for the detection of oral dysplasia and oral cancer.

Crucial roles of Pox neuro in the developing ellipsoid body and antennal lobes of the Drosophila brain.

The paired box gene Pox neuro (Poxn) is expressed in two bilaterally symmetric neuronal clusters of the developing adult Drosophila brain, a protocerebral dorsal cluster (DC) and a deutocerebral ventral cluster (VC). We show that all cells that express Poxn in the developing brain are postmitotic neurons. During embryogenesis, the DC and VC consist of only 20 and 12 neurons that express Poxn, designated embryonic Poxn-neurons. The number of Poxn-neurons increases only during the third larval instar, when the DC and VC increase dramatically to about 242 and 109 Poxn-neurons, respectively, virtually all of which survive to the adult stage, while no new Poxn-neurons are added during metamorphosis. Although the vast majority of Poxn-neurons express Poxn only during third instar, about half of them are born by the end of embryogenesis, as demonstrated by the absence of BrdU incorporation during larval stages. At late third instar, embryonic Poxn-neurons, which begin to express Poxn during embryogenesis, can be easily distinguished from embryonic-born and larval-born Poxn-neurons, which begin to express Poxn only during third instar, (i) by the absence of Pros, (ii) their overt differentiation of axons and neurites, and (iii) the strikingly larger diameter of their cell bodies still apparent in the adult brain. The embryonic Poxn-neurons are primary neurons that lay out the pioneering tracts for the secondary Poxn-neurons, which differentiate projections and axons that follow those of the primary neurons during metamorphosis. The DC and the VC participate only in two neuropils of the adult brain. The DC forms most, if not all, of the neurons that connect the bulb (lateral triangle) with the ellipsoid body, a prominent neuropil of the central complex, while the VC forms most of the ventral projection neurons of the antennal lobe, which connect it ipsilaterally to the lateral horn, bypassing the mushroom bodies. In addition, Poxn-neurons of the VC are ventral local interneurons of the antennal lobe. In the absence of Poxn protein in the developing brain, embryonic Poxn-neurons stall their projections and cannot find their proper target neuropils, the bulb and ellipsoid body in the case of the DC, or the antennal lobe and lateral horn in the case of the VC, whereby the absence of the ellipsoid body neuropil is particularly striking. Poxn is thus crucial for pathfinding both in the DC and VC. Additional implications of our results are discussed.

HER2/neu, p53, MIB1 and PAX8 immunoexpression in Primary Serous Fallopian Tube Carcinomas / Determinación inmunohistoquímica de HER2/neu, p53, MIB1 y PAX8 en el Carcinoma Seroso Primario de la Trompa Uterina

Background. Carcinoma of the fallopian tube is a rare gynecological malignancy. A previous review of Primary Fallopian Tube Carcinoma (PFTC) from a multi-institutional study identified several poor prognosis indicators, including the depth of invasion, advanced stage disease, tumor grade and the presence of lymph node metastases. The detection of the malignant lesion at an early stage and the identification of biomarkers with prognostic significance are the major concerns of recent studies. Aims. In this study, we have investigated the immunohistochemical expression of 4 proteins in cases of low-grade (n:5) and high-grade (n:65) serous PFTC to determine their role in PFTC prognosis. Material and methods. HER2/neu, p53, PAX8 and MIB-1 were evaluated using immunohistochemistry on a tissue microarray of 70 serous PFTC and the expression was correlated to the following clinico-pathologic variants: age, grade, lymph node metastases, stage and survival. Results. HER2/neu oncoprotein overexpression was demonstrated in 20 of 65 (31%) high-grade serous fallopian tube carcinomas. p53 was demonstrated in more than 50% (3+) of the tumor in 59 (90.7%) high-grade serous FTCs, while eight cases (12%) were moderate or weakly positive (2+). The expression of PAX8 was positive in 55 (78.5%) cases, the remaining 15 (21%) cases being negative. The outcome of the disease for patients with tumors showing HER2/neu overexpression was worse (p:0.0001). p53, MIB-1 or PAX8 failed to have a predictive value in disease outcome. Conclusion. The potential prognostic relevance of HER2/neu in tubal cancer and its potential role in the selection of patients for targeted therapy should be investigated further (AU)

Introducción. El carcinoma de la trompa uterina (TU) es una neoplasia poco frecuente del tracto ginecológico. Una revisión previa de los carcinomas primarios de la TU, en un estudio multiinstitucional, identificó varios factores de mal pronóstico, incluyendo profundidad de invasión, estadio avanzado, grado histológico y presencia de ganglios linfáticos metastásicos. Detectar esta neoplasia en estadios tempranos e identificar biomarcadores con significado pronóstico ha sido el objetivo de los últimos estudios. Objetivos. En este estudio investigamos la expresión de 4 proteínas a través de inmunohistoquímica en 70 casos de carcinomas serosos de la TU (CSTU) (5 de bajo grado [BG], y 65 de alto grado [AG]) para determinar su papel pronóstico. Material y métodos. Se evaluó el estado de HER2/neu, p53, PAX8 y MIB-1 en matrices de tejidos, y se correlacionó con las siguientes variantes clinicopatológicas: edad, grado, metástasis ganglionares, estadio y supervivencia. Resultados. Demostramos la sobreexpresión de la oncoproteína HER2/neu en 20 de 65 (31%) CSTU AG. p53 se expresó en más de 50% (3+) del tumor en 59 (90,7%) casos, mientras que en 8 casos (12%), la expresión fue moderada o débil (2+). El PAX8 se expresó en 55 (78,5%) casos, y los otros 15 casos (21%) fueron negativos. El pronóstico de las pacientes cuyos tumores sobreexpresaron el HER2/neu fue más adverso (p=0,0001). p53, MIB-1 o PAX-8 no tuvieron un papel predictivo en el pronóstico de la enfermedad. Conclusiones. La relevancia del papel pronóstico de la sobreexpresión del HER2/neu en el CSTU, así como la posibilidad de seleccionar pacientes para recibir terapias dirigidas deben ser investigadas en más estudios (AU)

Neuroendocrine Carcinoma of the Endometrium: A Clinicopathologic Study of 25 Cases.

Neuroendocrine carcinoma (NECa) of the endometrium is an uncommon tumor. In this study, we present the clinicopathologic features of 25 such cases. The patients ranged in age from 37 to 87 years (median, 57 y) and most commonly presented with vaginal bleeding. The tumors were either pure NECa (10) or mixed with other histotypes (15), most commonly endometrioid carcinoma. The NECas were large cell type (15), small cell type (4), or a mixture of both (6). NECa was underrecognized in 89% of referral/consultation cases. All tumors were positive for ≥1 neuroendocrine marker (chromogranin, synaptophysin, CD56). Additional immunohistochemical (IHC) studies were obtained in 18 cases, with positive results as follows: keratin cocktail (17), diffuse p16 (6), PAX-8 (6), CD117 (6), and TTF-1 (1). Mismatch-repair protein expression by IHC was abnormal in 8 of 18 cases (6 MLH1/PMS2 loss; 1 MSH2/MSH6 loss; 1 MSH6 loss). According to FIGO staging, cases were distributed as follows: I (6), II (2), III (10), and IV (7). All patients underwent surgical treatment, and 20 patients received adjuvant therapy. Twelve patients died of disease (mean survival 12.3 mo). Eleven patients were alive 5 to 134 months after diagnosis, including 7 who achieved a 5-year survival (3 stage I; 4 stage III). In summary, most of our endometrial NECas were large cell type, mixed with other histotypes, and underrecognized. These tumors tend to be PAX-8 negative and may be associated with microsatellite instability. The recognition of NECa may have an impact on the treatment of the patients affected by this disease. Although NECa usually has an aggressive behavior, 28% of our patients survived at least 5 years.

Impact and mechanistic role of oral contraceptive pills on the number and epithelial type of ovarian cortical inclusion cysts; a clinicopathology and immunohistochemical study.

BACKGROUND: Ovarian epithelial cancers are among the most lethal women's cancers. There is no doubt about the preventive role of oral contraceptive pills (OCPs) in development of ovarian cancers. But, there are limited numbers of studies to address the effect of these agents on the number of cortical inclusion cysts (CICs), their epithelial type and suppression of the metaplastic phenomenon by these pills. The aim of this study was to clarify the role of these agents in the prevention of these cyst formation and tubal metaplasia and also examine the mesenchymal-epithelial transition theory in this context by immunohistochemical methods. METHODS: The representative section(s) of ovarian cortex from a total number of 201 consecutive total abdominal hysterectomy with bilateral or unilateral salpingo-oophorectomy specimens were examined for mean number of CICs and their epithelial type between two groups of the patients. Group A included the patients who were on oral contraceptive pills for more than 5 years. All of the subjects with other contraceptive methods or a history of less than 5 years contraceptive pills usage were stratified in group B. Sections from 20 cases in which more than five inclusion cysts were found, were selected for IHC staining with calretinine and PAX8 as markers for mesothelium and mullerian epithelium respectively. RESULTS: The mean age of the patients was 51.67 years with no significant differences between two groups. The mean number of cysts were 1.27 and 3.23 in group A and B respectively (P =0.0001). Similarly the mean number of CICs, lined by tubal epithelium, was significantly different between two groups (0.65 vs 2.65, P =0.0001). In IHC staining 123 out of 150 CICs (82 %) were PAX+ while only 7 CICs (4.8 %) showed positive reaction for calretinin irrespective of type of epithelium. CONCLUSION: Our findings showed that the use of OCP for more than five years in women, significantly prevents development of cortical inclusion cysts in the ovaries which lined by tubal (PAX8 positive) type epithelium. These findings may explain the alternative mechanism of oral contraceptive pills or long time use of progesterone in suppression of tubal type overgrowth and subsequently prevention of ovarian epithelial cancers.

Assessment of the Utility of PAX8 Immunohistochemical Stain in Diagnosing Endocervical Glandular Lesions.

CONTEXT: PAX8, a member of the paired-box family of genes, is expressed in many tumors of Müllerian origin. However, it is unclear whether PAX8 is a useful marker in diagnosing endocervical glandular lesions because of limited data. OBJECTIVE: To study the expression of PAX8 in endocervical glandular lesions. DESIGN: We first studied a cohort of 29 cervical cone biopsies, followed by a second cohort of 17 cases of endocervical adenocarcinoma and 20 cases of uterine endometrioid adenocarcinoma. RESULTS: In the first cohort, we found that PAX8 was expressed in 23 of 23 (100%) benign endocervical glandular epithelium, 15 of 16 (94%) adenocarcinoma in situ, and 21 of 26 (81%) invasive endocervical adenocarcinoma specimens. In the second cohort, endocervical adenocarcinomas were positive for PAX8 in 14 of 17 (82%), strongly and diffusely positive for p16 in 14 of 17 (82%), positive for carcinoembryonic antigen in 12 of 17 (71%), positive for vimentin in 2 of 17 (12%), and positive for estrogen receptor in 7 of 17 cases (41%). Uterine endometrioid cancer was positive for PAX8 in 20 of 20 (100%), weakly and/or patchy positive for p16 in 17 of 20 (85%), positive for carcinoembryonic antigen in 2 of 20 (10%), positive for vimentin in 19 of 20 (95%), and positive for estrogen receptor in 20 of 20 cases (100%). CONCLUSIONS: PAX8 is expressed in the majority of benign, premalignant, and malignant endocervical glandular lesions. The usefulness of PAX8 in differentiating endocervical from endometrial lesions is limited.

A Detailed Immunohistochemical Analysis of a Large Series of Cervical and Vaginal Gastric-type Adenocarcinomas.

Adenocarcinomas exhibiting gastric differentiation represent a recently described and uncommon subtype of non-human papillomavirus (HPV)-related cervical adenocarcinoma. They comprise a spectrum from a well-differentiated variant (adenoma malignum/mucinous variant of minimal deviation adenocarcinoma) to a more poorly differentiated overtly malignant form, generally referred to as gastric-type adenocarcinoma. Rarely, such tumors have also been described as primary vaginal neoplasms. Gastric-type adenocarcinomas exhibit considerable morphologic overlap with adenocarcinomas originating outside the female genital tract, especially mucinous adenocarcinomas arising in the pancreas and biliary tract. Moreover, they often metastasize to unusual sites, such as the ovary and peritoneum/omentum, where they can be mistaken for metastatic adenocarcinomas from other, nongynecologic sites. There is little information regarding the immunophenotype of gastric-type adenocarcinomas, and knowledge of this is important to aid in the distinction from other adenocarcinomas. In this study, we undertook a detailed immunohistochemical analysis of a large series of cervical (n=45) and vaginal (n=2) gastric-type adenocarcinomas. Markers included were cytokeratin (CK)7, CK20, CDX2, carcinoembryonic antigen, CA125, CA19.9, p16, estrogen receptor, progesterone receptor, MUC6, PAX8, PAX2, p53, hepatocyte nuclear factor 1 beta, carbonic anhydrase IX, human epidermal receptor 2 (HER2), and mismatch repair (MMR) proteins. All markers were classified as negative, focal (<50% of tumor cells positive), or diffuse (≥50% tumor cells positive) except for p53 (classified as "wild-type" or "mutation-type"), HER2 (scored using the College of American Pathologists guidelines for gastric carcinomas), and MMR proteins (categorized as retained or lost). There was positive staining with CK7 (47/47-45 diffuse, 2 focal), MUC6 (17/21-6 diffuse, 11 focal), carcinoembryonic antigen (25/31-12 diffuse, 13 focal), carbonic anhydrase IX (20/24-8 diffuse, 12 focal), PAX8 (32/47-20 diffuse, 12 focal), CA125 (36/45-5 diffuse, 31 focal), CA19.9 (11/11-8 diffuse, 3 focal), hepatocyte nuclear factor 1 beta (13/14-12 diffuse, 1 focal), CDX2 (24/47-4 diffuse, 20 focal), CK20 (23/47-6 diffuse, 17 focal), and p16 (18/47-4 diffuse, 14 focal). Most cases were negative with estrogen receptor (29/31), progesterone receptor (10/11), PAX2 (18/19), and HER2 (25/26). p53 showed "wild-type" and "mutation-type" staining in 27 of 46 and 19 of 46 cases, respectively. MMR protein expression was retained in 19 of 20 cases with loss of MSH6 staining in 1 patient with Lynch syndrome. Molecular studies for HPV were undertaken in 2 tumors, which exhibited diffuse "block-type" immunoreactivity with p16, and both were negative. This is the first detailed immunohistochemical study of a large series of gastric-type adenocarcinomas of the lower female genital tract. Our results indicate immunophenotypic overlap with pancreaticobiliary adenocarcinomas but suggest that PAX8 immunoreactivity may be especially useful in distinguishing gastric-type adenocarcinomas from pancreaticobiliary and other nongynecologic adenocarcinomas, which are usually negative. Diffuse "block-type" p16 immunoreactivity in a cervical adenocarcinoma is not necessarily indicative of a high-risk HPV-associated tumor.

Cytologic Features and Immunocytochemical Profiles of Malignant Effusions with Metastatic Papillary Thyroid Carcinoma: A Case Series from a Single Institution.

OBJECTIVE: Malignant effusions due to papillary thyroid carcinoma (PTC) are rare, but portend a poor prognosis. PTC metastases, although rare, most frequently occur in the lungs and bone. Therefore, differentiating thyroid etiology of malignant effusions from other sites becomes clinically significant in patient management. This study examines morphologic and immunocytochemical findings in 5 cases of malignant effusions with PTC involvement. STUDY DESIGN: The electronic database at the University of Michigan was searched from January 1, 1995 to December 31, 2014 for malignant pleural effusions with PTC involvement. Clinicopathologic data were obtained from electronic medical records. Cytologic slides were reviewed. RESULTS: Five cases of malignant effusions due to PTC were identified. Characteristic cytologic features of PTC, including ovoid nuclei, irregular nuclear contours, and psammomatous calcifications, were seen. However, the predominant cytologic feature observed was moderate amounts of delicate to vacuolated cytoplasm within the tumor cells. A review of immunocytochemistry demonstrated that all 5 cases showed patchy to diffuse TTF-1 positivity and diffuse positivity for Pax-8. Thyroglobulin only showed focal to patchy positivity in 3 of 5 cases. CONCLUSION: Given the morphologic features found in our case series, an immunocytochemical workup for the evaluation of involvement of an effusion by a thyroid primary is crucial for accurate diagnosis and appropriate clinical treatment.

Clonality analysis of combined Brenner and mucinous tumours of the ovary reveals their monoclonal origin.

The derivation of ovarian intestinal-type mucinous tumours is not well established. Some are derived from teratomas but the origin of the majority is not clear. It has been recently proposed that the non-germ cell group may be derived from Brenner tumours, as the association of a mucinous tumour with a Brenner tumour is frequently observed. In order to explore the histogenesis of these neoplasms, we undertook a clonality analysis of the two components of ten combined Brenner and mucinous tumours using a human androgen receptor gene (HUMARA) assay. All eight informative cases of ten showed a concordant X-chromosome inactivation pattern between the two tumour components, indicative of a shared clonal origin (p = 0.0039). Microsatellite genotyping in five of the combined tumours displayed an identical heterozygous pattern with paired Fallopian tube tissue, indicative of a somatic cell origin. In addition, paired box protein 8, a highly sensitive Müllerian epithelial marker, was not detected by immunohistochemistry in either tumour component in any of the ten tumours, suggesting that this subset of mucinous tumours does not originate from Müllerian-derived epithelium. In conclusion, this study demonstrates that in combined mucinous and Brenner tumours, there is a shared clonal relationship between the two different tumour components and suggests that some pure mucinous tumours may develop from a Brenner tumour in which the Brenner tumour component becomes compressed and obliterated by an expanding mucinous neoplasm.

Assessing methylation status of PAX1 in cervical scrapings, as a novel diagnostic and predictive biomarker, was closely related to screen cervical cancer.

OBJECTIVE: Previous studies have demonstrated that levels of hypermethylation of paired boxed gene 1 in cervical tissues are associated with the grades of severities of cervical neoplasia in women, which suggests that testing for DNA methylation has a potential role in neoplasma screening. In this study, by testing methylation levels of PAX1 genes in cervical scrapings and cervical tissues of different lesion levels, aims to evaluate the diagnostic value of DNA methylation testing as a biomarker for early detecting cancerous changes in cervical tissues and to compare the efficacy between PAX1 methylation test and HPV test in detecting of cervical cancer. METHODS: A total of 121 cervical scrapings were analyzed, including normal (n = 28), cervical intraepithelial neoplasm 1 (CIN1; n = 32), CIN2/3 (n = 34), and invasive cancer (n = 27), which were all diagnosed by pathologic examination. RESULTS: The values of PAX1 methylation reference in invasive cancer (mean [SE], 26.3 [3.5]) was significantly higher than CIN2/3 (13. 2 [2.2]) and the CIN1 (4.5 [0.45]; P < 0.001). The PAX1 promoter was hypermethylated in 100% of invasive cancer tissue compared with 0% of normal tissue, 9% of CIN1, 44% of CIN2/3 (P < 0.01). Methylation levels of cervical scrapings and cervical tissues represent strong consistency within each group. In contrast, the HPV test result was positive in 17% of normal tissue, 81% of CIN1, 91% of CIN2/CIN3, and 92% of invasive cancer. Based on receiver operating characteristic (ROC) analysis, hypermethylation of PAX1 was a significant candidate in segregating cervical cancer from normal/cervical neoplasia cases (P < 0.001). At an optimal cutoff value, sensitivity and specificity between 80% and 93% were obtained. In conclusion, the current results indicated that the methylation density of PAX1 by pyrosequencing in cervical scrapings held a great promise for cervical cancer screening.

Napsin A is frequently expressed in clear cell carcinoma of the ovary and endometrium.

Napsin A is a reliable marker for pulmonary adenocarcinoma and is expressed in a subset of ovarian clear cell carcinomas (O-CCCs), endometrial (EM) CCCs, and endometrioid carcinomas (EC). We investigated napsin A levels in O-CCC and EM-CCC and compared these with levels in other nonmucinous ovarian carcinomas and EM-EC, respectively. Napsin A, thyroid transcription factor (TTF)-1, paired box (PAX) 8, and cancer antigen (CA) 125 expression was evaluated in 111 ovarian and uterine carcinoma cases (22 O-CCC, 15 EM-CCC, 13 ovarian EC (O-EC), 39 high-grade serous carcinoma [HGSC], and 22 EM-EC) using immunohistochemistry. Napsin A immunoreactivity was observed in 21 (95.5%) of 22 O-CCC and 10 (66.7%) of 15 EM-CCC cases but was rare in O-EC and EM-EC (7.7% and 4.5%) and undetectable in HGSC cases. Thyroid transcription factor 1 was not expressed in O-CCC but was detected in 1 (6.7%) of 15 EM-CCC, 3 (23.1%) of 13 O-EC, 2 (5.1%) of 39 HGSC, and 1 (4.5%) of 22 EM-EC cases. All 111 cases examined were positive for PAX8, whereas 3 (20.0%) of 15 of EM-CCC and 1 (4.5%) of 22 EM-EC cases were negative for CA125. There were no napsin A/TTF-1 double-positive cases, except for 1 EM-CCC, in which cells had a focal expression pattern. All napsin A- and/or TTF-1-positive cases expressed PAX8 and CA125. In conclusion, napsin A is frequently expressed in O-CCC and EM-CCC, rarely in O-EC and EM-EC, and never in HGSC cases. These findings confirm the importance of using a panel of antibodies that includes napsin A, TTF-1, and PAX8 when evaluating metastatic carcinomas of unknown origin, particularly when gynecologic and pulmonary adenocarcinomas are included in the differential diagnosis.

Differentiating primary and extragenital metastatic mucinous ovarian tumours: an algorithm combining PAX8 with tumour size and laterality.

AIMS: Our aim was to analyse the utility of the algorithm combining PAX8 with clinicopathological characteristics (tumour size, laterality and patient age) in differentiating primary ovarian mucinous tumours (POMTs) from extragenital metastatic mucinous carcinomas involving the ovary (eMOMCs). METHODS AND RESULTS: Immunohistochemical staining for PAX8 was performed on formalin fixed, paraffin embedded tissues from 47 POMTs, 18 eMOMCs and 70 extragenital primary mucinous carcinomas (ePMCs) using anti-PAX8 rabbit polyclonal antibody (pAb) and anti-PAX8 rabbit monoclonal antibody (mAb). PAX8 (pAb) positive signals were found in 3/18 eMOMCs and in 32/70 ePMCs. PAX8 (mAb) demonstrated superior specificity, with 0% positivity in both eMOMCs and ePMCs, but unfavourable sensitivity, with 60.9% in ovarian mucinous borderline tumours and 45.8% in POMCs. Although PAX8 (mAb) immunostaining status (66.2%), tumour size (75.4%) and laterality (84.6%) demonstrated unsatisfactory accuracy when they were evaluated individually in differentiating POMTs from eMOMCs, a combination of PAX8 (mAb) immunostaining status, tumour size and laterality markedly increased accuracy (86.2%), with a satisfactory Youden Index (63.7%). CONCLUSIONS: PAX8 (mAb) was a specific marker in differentiating POMTs from eMOMCs. As a simple, convenient and high performance to price ratio algorithm, a combination of PAX8 (mAb) immunostaining with tumour size and laterality will improve the diagnostic criteria of ovarian mucinous metastasis.

Simultaneous carcinomas of the breast and ovary: utility of Pax-8, WT-1, and GATA3 for distinguishing independent primary tumors from metastases.

Breast carcinomas rarely metastasize to the ovary and are even more rarely present clinically as primary ovarian tumors. However, patients with breast cancer not infrequently develop independent primary ovarian carcinomas. In these cases, distinction between independent primaries and metastatic tumors is crucial. Several comparative immunohistochemical studies have been reported, but few included significant clinicopathologic data and none investigated cases of ovarian and breast carcinomas from the same patients. In this study, we compared 18 cases of patients with bona fide independent breast and ovarian carcinomas (15 high-grade serous and 3 clear cell carcinomas), with 9 cases of patients with known mammary carcinomas (7 lobular and 2 ductal carcinomas) metastatic to the ovary. Immunohistochemical stains for Pax-8, WT-1, and GATA3 were carried out on tissue microarrays (TMA). Most primary ovarian carcinomas were larger than the metastatic tumors (P=0.001) and were diagnosed at an advanced stage. All primary ovarian tumors showed marked nuclear pleomorphism, whereas only 2 metastatic breast carcinomas had Grade 3 nuclei (P=0.000). The vast majority of ovarian metastases (7/9) showed the typical pattern of lobular breast carcinoma. Pax-8 and WT-1 expression were found in 16 of 18 (88%) and 13 of 18 (72%) primary ovarian carcinomas, respectively. In contrast, all primary ovarian carcinomas were negative for GATA3. The 2 Pax-8-negative ovarian carcinomas were also negative for WT-1. With the exception of 3 triple-negative carcinomas, all primary breast carcinomas were positive for GATA3. All metastatic breast carcinomas were positive for GATA3 and negative for Pax-8. WT-1 expression was seen in only 1 of 9 metastatic breast carcinomas (11%). Patients with ovarian metastases had worse prognosis than patients with independent breast and ovarian carcinomas (P=0.000). Pax-8, WT-1, and GATA3 immunoreactions are useful in the distinction between independent primaries and metastatic mammary carcinomas to the ovary in the light of clinicopathologic findings.

Primary mediastinal seminomas: a comprehensive immunohistochemical study with a focus on novel markers.

Primary mediastinal seminomas are unusual tumors that can present in a pure form or as part of a mixed germ cell tumor. Contrary to testicular seminomas, little is known about the expression of novel immunohistochemical markers in mediastinal seminomas. This study investigates the immunohistochemical features of these tumors with a focus on novel markers. Thirty-two cases of primary mediastinal seminomas were reviewed; and representative whole-tissue sections were selected for immunohistochemical studies using antibodies directed against high molecular weight cytokeratin 5/6 (CK5/6), low molecular weight cytokeratin (CAM5.2), octamer-binding transcription factor 3/4 (OCT3/4), spalt-like transcription factor 4 (SALL4), GATA binding protein 3 (GATA-3), sry-related HMG box 2 (SOX2), SOX17, human T cell leukemia/lymphoma 1 (TCL1), glypican 3, melanoma associated antigen C2 (MAGEC2), and paired box gene 8 (Pax8). The percentage of positive tumor cells as well as the intensity of staining was evaluated and scored. Thirty-one cases (97%) expressed SOX17, whereas 29 cases (91%) were positive for OCT3/4 and SALL4, respectively. Twenty-eight cases (88%) expressed MAGEC2 and CAM5.2, respectively. Two cases (6%) were positive for Pax8, and a single case (3%) was positive for TCL1. None of the cases stained with CK5/6, GATA-3, SOX2, or glypican 3. Similar to testicular seminomas, mediastinal seminomas show consistent expression of OCT3/4, SALL4, SOX17, and MAGEC2 and are negative for SOX2, glypican 3, GATA-3, and CK5/6. Pax8 positivity is only inconsistently identified in mediastinal seminomas. Contrary to their testicular counterparts, mediastinal tumors show diffuse expression of low-molecular-weight cytokeratin in up to 90% of cases and are commonly negative for TCL1. Although there is some immunohistochemical overlap between testicular and mediastinal seminomas, considerable differences also exist and should be acknowledged when dealing with these tumors.

Evaluation of PAX2 and PAX8 expression in salivary gland neoplasms.

PAX2 and PAX8 are transcription factors involved in embryogenesis that have been utilized as immunohistochemical indicators of tumor origin. Specifically, PAX2 is a marker of neoplasms of renal and müllerian origin, while PAX8 is expressed by renal, müllerian, and thyroid tumors. While studies examining these transcription factors in a variety of tumors have been published, data regarding their expression in salivary gland neoplasms are limited. The goal of this study was to assess expression of PAX2 and PAX8 in a large cohort of salivary gland tumors. Utilizing tissue microarrays, samples of normal salivary glands (n = 68) and benign and malignant salivary gland neoplasms (n = 442) were evaluated for nuclear immunoreactivity with PAX2 and PAX8. No expression was observed with either marker in the normal salivary glands, and PAX8 was negative in all neoplasms. Focal expression of PAX2 was observed in one example each of oncocytoma and acinic cell carcinoma. These results indicate that evaluation of PAX2 and/or PAX8 expression would be valuable in differentiating primary salivary gland tumors from metastases known to express PAX2 and/or PAX8.

Pax6 controls centriole maturation in cortical progenitors through Odf2.

Cortical glutamatergic neurons are generated by radial glial cells (RGCs), specified by the expression of transcription factor (TF) Pax6, in the germinative zones of the dorsal telencephalon. Here, we demonstrate that Pax6 regulates the structural assembly of the interphase centrosomes. In the cortex of the Pax6-deficient Small eye (Sey/Sey) mutant, we find a defect of the appendages of the mother centrioles, indicating incomplete centrosome maturation. Consequently, RGCs fail to generate primary cilia, and instead of staying in the germinative zone for renewal, RGCs detach from the ventricular surface thus affecting the interkinetic nuclear migration and they exit prematurely from mitosis. Mechanistically, we show that TF Pax6 directly regulates the activity of the Odf2 gene encoding for the appendage-specific protein Odf2 with a role for the assembly of mother centriole. Our findings demonstrate a molecular mechanism that explains important characteristics of the centrosome disassembly and malfunctioning in developing cortex lacking Pax6.

Comparison of PAX6 and PAX8 as immunohistochemical markers for pancreatic neuroendocrine tumors.

To compare the utility of PAX6 and PAX8 as immunohistochemical markers for neuroendocrine tumors (NETs) of pancreatic origin, we performed PAX6 and PAX8 immunostains on 178 NETs, including 110 primary NETs (26 pancreatic, 10 gastric, 12 duodenal, 22 jejuno-ileal, 10 rectal, 30 pulmonary) and 68 NETs metastatic to the liver (24 pancreatic, 1 duodenal, 37 jejuno-ileal, 1 rectal, 5 pulmonary). Among primary NETs, PAX6 and PAX8 were positive in 65 % (17/26) and 73 % (19/26) of pancreatic, 0 % (0/10) and 10 % (1/10) of gastric, 92 % (11/12) and 92 % (11/12) of duodenal, 0 % (0/22) and 0 % (0/22) of jejuno-ileal, 90 % (9/10) and 80 % (8/10) of rectal, and 0 % (0/30) and 23 % (7/30) of pulmonary NETs, respectively. PAX6 and PAX8 positivity was seen in 46 % (11/24) and 50 % (12/24) of metastatic pancreatic NETs to the liver, respectively. None of the nonpancreatic NETs metastatic to the liver were immunoreactive for either PAX6 or PAX8. PAX6 showed a slightly but statistically significant higher specificity for pancreatic NETs than did PAX8 (P = 0.039), while the sensitivities were similar (P = 0.51). PAX6 had the additional advantages over PAX8 of not exhibiting nonspecific cytoplasmic staining of tumor cells and only infrequently staining background lymphocytes. Since rectal NETs rarely present with metastatic disease, positive staining of a metastatic NET of unknown primary origin for PAX6 and/or PAX8 favors a pancreatic or duodenal origin. This information may be helpful in directing further diagnostic studies to identify the primary site of the metastatic tumor.

Intrinsic transient tracheal occlusion training and myogenic remodeling of rodent parasternal intercostal fibers.

It is recognized that diaphragm muscle plasticity occurs with mechanical overloads, yet less is known about synergistic parasternal intercostal muscle fiber remodeling. We conducted overload training with intrinsic transient tracheal occlusion (ITTO) exercises in conscious animals. We hypothesized that ITTO would yield significant fiber hypertrophy and myogenic activation that would parallel diaphragm fiber remodeling. Sprague-Dawley rats underwent placement of a tracheal cuff and were randomly assigned to receive daily 10 min sessions of conscious ITTO or observation (sham) over 2 wk. After training, fiber morphology, myosin heavy chain (MHC) isoform composition, cross-sectional area, proportion of Pax7-positive nuclei, and presence of embryonic MHC (eMHC) were quantified. Type IIx/b fibers were 20% larger after ITTO training than with sham training (ITTO: 4,431 +/­ 676 µm2, sham: 3,689 +/­ 400 µm2, p < 0.05), and type I fibers were more prevalent after ITTO (p < 0.01). Expression of Pax7 was increased in ITTO parasternals and diaphragm (p < 0.05). In contrast, the proportion of eMHC-positive fibers was increased only in ITTO parasternals (1.2% [3.4%­0.6%], sham: 0% [0.6%­0%], p < 0.05). Although diaphragm and parasternal type II fibers hypertrophy to a similar degree, myogenic remodeling appears to differ between the two muscles.