Nuclear Beta-catenin Expression Research Articles

Beta-Catenin Alterations in Postchemotherapy Yolk Sac Tumor, Postpubertal-Type With Enteroblastic Features

Postchemotherapy postpubertal-type yolk sac tumors (YST) with glandular and solid phenotypes are aggressive and commonly resistant to systemic chemotherapy. These neoplasms show morphologic features that significantly overlap with those of somatic carcinomas with “enteroblastic” or “fetal” phenotype (the preferred terminology depends on the site of origin). They often present as late or very late recurrences, and their diagnosis is challenging because they frequently affect patients in an age group at risk for carcinomas of somatic origin. Recently, we incidentally identified examples of postchemotherapy glandular and solid YST with “enteroblastic” phenotypes and nuclear expression of beta-catenin, prompting us to further evaluate the prevalence of this phenomenon. We found nuclear expression of beta-catenin in 10 (29%) of 34 such tumors. A subset of cases with nuclear beta-catenin expression was further analyzed with a DNA sequencing panel (n = 6) and fluorescence in situ hybridization for isochromosome 12p [i(12p); n = 5]. Sequencing identified exon 3 CTNNB1 variants in 3 (50%) of 6 analyzed cases, and fluorescence in situ hybridization was positive for i(12p) in 5 of 5 cases. In conclusion, a significant subset of postchemotherapy YST with glandular or solid architecture and “enteroblastic” phenotype demonstrates beta-catenin alterations, suggesting that activation of Wnt signaling may play a role in the progression of these neoplasms. Moreover, nuclear beta-catenin expression in these tumors represents a potential diagnostic pitfall given that carcinomas of true somatic origin with overlapping morphology may also be positive for this marker.

Beta-Catenin Nuclear Expression in Squamoid Morules in Colorectal Adenomas: Clinicopathologic Study of Fifteen Cases

Abstract Introduction/Objective Squamoid morules are an intriguing finding rarely seen in colorectal adenomas, mimicking foci of microinvasion or neuroendocrine differentiation. Previous observations include mostly case reports and small series, with few examining the squamoid morules in detail. Methods/Case Report We identified fifteen colorectal adenomas with squamoid morules and collected clinicopathological data including age, sex, procedure, location, pathologic diagnosis, and size. A representative block was chosen for immunohistochemistry in each case. The expression of p40, p63, CK5/6, beta-catenin, synaptophysin, chromogranin, and Ki-67 in squamoid morules were examined immunohistochemically. Results (if a Case Study enter NA) The fifteen patients comprised thirteen males and two females ranging in age from 45 to 85 years (average: 60.6 years old). The adenomas were removed by endoscopic resection (n = 7) or surgical resection (n = 8). Nine adenomas were found in the rectosigmoid colon, one in the descending colon, and five in the right colon. Eleven adenomas were tubulovillous adenomas (average: 3.8 cm, ranging 1.0 to 6.0 cm) and four were tubular adenomas (average: 2.6 cm, ranging 1.6 to 3.0 cm). Seven adenomas contained invasive adenocarcinoma. Squamoid morules were randomly distributed in adenomas. All foci of squamoid morules showed beta-catenin nuclear positivity and most (more than 90 %) showed CK5/6 expression. Squamoid morules were focally positive for p63 in three adenomas and focally positive for p40 in one adenoma. In one adenoma squamoid morules are positive for both synaptophysin and chromogranin. In all fifteen adenomas squamoid morules were negative for Ki- 67. Conclusion Squamoid morules are characterized by strong male predominance, association with large adenoma size, beta-catenin nuclear positivity, CK5/6 expression, and no Ki-67 expression. Beta-catenin nuclear expression is helpful in distinguishing squamoid morules from foci of microinvasion.

Germline APC Alterations May Predispose to Testicular Sex Cord-Stromal Tumors.

Sertoli cell tumor is a type of testicular sex cord-stromal tumor (TSCST) typically driven by gain-of-function CTNNB1 variants. Recently, molecular studies have identified TSCSTs (including Sertoli cell tumors) with loss-of-function APC variants, raising the possibility that germline APC alterations may predispose to TSCSTs. In this study, we evaluated 4 TSCSTs from 4 individual patients, including 3 APC -mutant neoplasms identified in prior studies (1 in a patient with familial adenomatous polyposis [FAP] and 2 in patients with unknown syndromic status) and 1 tumor of unknown mutational status diagnosed in a patient with known FAP. Three neoplasms were typical Sertoli cell tumors, and 1 was a malignant unclassified TSCT. All neoplasms exhibited diffuse nuclear beta-catenin expression. Non-neoplastic tissue could be obtained for DNA sequencing in the 3 Sertoli cell tumors. Comparative assessment of non-neoplastic and lesional tissue in these cases suggested that germline APC variants with subsequent inactivation of the gene (loss of heterozygosity) were the likely oncogenic driver of these Sertoli cell tumors. In the malignant unclassified TSCSTs, APC inactivation was also interpreted as the most likely driver event, and the germline origin of the variant was inferred using a recently published method. The results of this study suggest that pathogenic germline APC alterations (eg, FAP and variants thereof) may predispose to TSCSTs.

An Expanded Series of Pilomatrix-like High-grade Endometrioid Carcinoma (PiMHEC), Including Both MMR Deficient and MMR Proficient Cases.

An Expanded Series of Pilomatrix-like High-grade Endometrioid Carcinoma (PiMHEC), Including Both MMR Deficient and MMR Proficient Cases.

Immunohistochemical assessment of COX2, P53, and beta-catenin expression to predict metachronous lesion development following polypectomy.

234 Background: Following colorectal polypectomy, 20-50% develop metachronous polyps, and some have increased colorectal cancer (CRC) risk. Surveillance colonoscopy is recommended to high-risk patients, based on index polyp number, histology and size. We aimed to assess if COX2, p53 and beta-catenin expression could predict metachronous polyp/ CRC risk. Methods: Tissue microarrays (TMA’s) were constructed for 339 patients from the INCISE study, a retrospective analysis of all patients undergoing screening polypectomy (Apr’09-Dec’16) followed by surveillance (6months-6years) in Glasgow, UK. Epithelial COX2, p53 and beta-catenin expression were assessed for each patient’s most advanced index polyp using immunohistochemistry, quantified by QuPath software. Kaplan-Meier analysis, log-rank tests and univariate/ multivariate cox regression assessed the association between marker expression and time to metachronous polyp/ CRC detection. Results: Low nuclear p53 expression was associated with shorter time to metachronous polyp/ CRC detection (p=0.024). Low nuclear (p=0.012) and membranous (p=0.046) beta-catenin expression was associated with shorter time to metachronous polyp/ CRC detection. There was no association between cytoplasmic COX2 expression and time to metachronous polyp/ CRC detection overall (p=0.309), but high cytoplasmic COX2 expression was associated with shorter time to detection of advanced metachronous lesions (advanced colorectal polyps/ CRC) (p=0.011). A combined score using the two most powerful biomarkers (nuclear p53 and nuclear beta-catenin – both high/ one low/ both low) was also associated with shorter time to metachronous polyp/ CRC detection (p=0.011). Univariate and multivariate cox regression are shown. Conclusions: Index polyp number and combined nuclear p53/beta-catenin expression independently predicted time to metachronous polyp/ CRC detection. [Table: see text]

Post‐radiotherapy cribriform‐morular thyroid carcinoma

According to the new 2022 World Health Organization classification of endocrine tumors, thyroid malignancy, formerly known as the cribriform-morular variant of papillary thyroid carcinoma, is now categorized as differentiated thyroid malignancy; it is, at present, called cribriform-morular thyroid carcinoma and classified as a tumor of unknown histogenesis. In this case report, we report on a 15-year-old patient who underwent external radiotherapy to the neck for Hodgkin's disease and developed cribriform-morular thyroid carcinoma 5 years after radiotherapy. We believe that cribriform-morular thyroid carcinoma with diffuse nuclear beta-catenin expression has exciting and unresolved uncertainties that may affect disease prognosis and follow-up for cytopathologists and endocrinologists.

Clinical and histopathologic characterization of SETD2-mutated colorectal cancer

With the advent of next-generation sequencing (NGS), identifying and better understanding genetic mutations in cancer pathways has become more feasible. A mutation now commonly reported in NGS panels is the SETD2 gene (H3K36 trimethyltransferase). However, its contributions to colorectal cancer (CRC) are not well described. In this study, we describe the clinicopathologic characteristics of SETD2-mutated CRC, determine common mutation sites on the SETD2 gene, and correlate these mutations with the loss of H3K36 trimethylation and the aberrant expression of beta-catenin. By searching pathology reports at our institution which included the 161-gene NGS panel from 2019 to 2021, we identify 24 individuals with SETD2-mutated CRC. All samples were evaluated for microsatellite status, H3K36 trimethylation, and beta-catenin via immunohistochemistry. In this cohort of 24 SETD2-mutated CRC individuals (a median age of 62.4 years [interquartile range: 49.1-73.6]), 10 (41.7%) patients presented at American Joint Committee on Cancer (AJCC) tumor stage II, seven (29.2%) at stage III, six (25%) at stage IV, and one (4.2%) at stage I. Most tumors studied were adenocarcinomas with no further specification (22, 92%), and most tumors were microsatellite stable (18, 82.5%). Thirty-three mutation locations were represented by 24 patients, with one patient having six mutations in the SETD2 gene and two patients having three mutations. The dominant mutation type is missense mutations (N=29, 87.9%), and no mutation hotspots were found. Only two samples lost trimethylation of histone H3K36, both from individuals with multiple SETD2 mutations and aberrant nuclear beta-catenin expression. SETD2-mutated CRC is similar in clinical and histologic presentation to other commonly reported CRC. SETD2 mutations were missense dominantand showed no hotspots, and multiple mutations are likely necessary for loss of H3K36 trimethylation. These results warrant further study on determining a role of SETD2-histone H3K36 pathway in CRC.

Spontaneous Occurrence of Various Types of Hepatocellular Adenoma in the Livers of Metabolic Syndrome-Associated Steatohepatitis Model TSOD Mice.

Male Tsumura-Suzuki Obese Diabetes (TSOD) mice, a spontaneous metabolic syndrome model, develop non-alcoholic steatohepatitis and liver tumors by feeding on a standard mouse diet. Nearly 70% of liver tumors express glutamine synthetase (GS), a marker of hepatocellular carcinoma. In contrast, approximately 30% are GS-negative without prominent nuclear or structural atypia. In this study, we examined the characteristics of the GS-negative tumors of TSOD mice. Twenty male TSOD mice were sacrificed at 40 weeks and a total of 21 tumors were analyzed by HE staining and immunostaining of GS, liver fatty acid-binding protein (L-FABP), serum amyloid A (SAA), and beta-catenin. With immunostaining for GS, six (29%) tumors were negative. Based on the histological and immunohistological characteristics, six GS-negative tumors were classified into several subtypes of human hepatocellular adenoma (HCA). One large tumor showed generally similar findings to inflammatory HCA, but contained small atypical foci with GS staining and partial nuclear beta-catenin expression suggesting malignant transformation. GS-negative tumors of TSOD mice contained features similar to various subtypes of HCA. Different HCA subtypes occurring in the same liver have been reported in humans; however, the diversity of patient backgrounds limits the ability to conduct a detailed, multifaceted analysis. TSOD mice may share similar mechanisms of HCA development as in humans. It is timely to review the pathogenesis of HCA from both genetic and environmental perspectives, and it is expected that TSOD mice will make further contributions in this regard.

Abstract 5914: E-cadherin and beta-catenin in oral dysplasia progression

Abstract Objectives: Epithelial-mesenchymal transition (EMT), a biological process characterized by a progressive decrease in epithelial features and increase in mesenchymal traits, has been suggested as a critical mechanism in cancer development. A defining feature of EMT is the loss of E-cadherin. Together with beta-catenin, alpha-catenin, and p120-catenin, E-cadherin forms the adherens junctions, which are involved in cell-cell adhesion of epithelial cells. As beta-catenin has both a structural and signaling role, E-cadherin potentially contributes to malignant progression via beta-catenin signaling through the Wnt pathway. E-cadherin and beta-catenin expression is altered from normal oral tissue, oral epithelial dysplasia (OED), to oral squamous cell carcinoma (OSCC), but there is no longitudinal research on the role of these biomarkers in malignant progression. The objective of this study is to explore the expression of E-cadherin and beta-catenin in OED and to determine if these expression patterns predict malignant progression. Methods: 28 progressors (PR) and 56 non-progressors (NPR) were included in this case-control study. Samples that progressed to severe OED, carcinoma in situ, or OSCC were categorized as PRs, and samples that did not progress were NPRs. Patient samples with a baseline biopsy of low-grade (mild or moderate) OED and at least 5 years of follow-up for NPRs were obtained from the Oral Cancer Prediction Longitudinal study, which has been prospectively following patients with OED for over 20 years. Immunohistochemistry (IHC) is performed on formalin-fixed paraffin-embedded tissue samples to assess for reduced membranous E-cadherin, and reduced membranous and increased cytoplasmic and/or nuclear beta-catenin expression in PRs compared to NPRs. We hypothesized that OED with this expression pattern will show greater likelihood of progression. Fisher’s exact test was used. Logistic regression will be performed to predict progression. Results: There were no significant differences in age, sex, risk of lesion site, and grade of dysplasia between PRs and NPRs. There were significant differences in length of follow-up time and smoking history. IHC has been completed on 27 samples to date, which show decreased membranous beta-catenin expression in PRs compared to NPRs (p=0.042). IHC for additional samples will be performed to assess for cytoplasmic and nuclear beta-catenin expression, and to compare expression patterns between PRs and NPRs to determine prediction of malignant progression. Conclusion: Early results suggest that membranous beta-catenin expression may be decreased in OED that progressed compared to OED that did not. This research enhances the understanding of EMT’s role in malignant progression and hopes to potentially aid in the intervention of oral lesions at risk of cancer. Citation Format: Ilena Yim, Iris Lin, Leigha Rock, Lewei Zhang, Miriam Rosin, Denise Laronde. E-cadherin and beta-catenin in oral dysplasia progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5914.

Immunohistochemical expression of beta-catenin in hepatoblastoma and its clinical significance.

Primary hepatic malignancies account for 0.5-2% of all solid tumours in childhood. Hepatoblastoma, a rare embryonic tumour in the general population, represents the most frequent primary hepatic malignancy in the paediatric age group, with an incidence of one new case per million under 15 years of age, median age at diagnosis being 1 year. Aberrant activation of the Wnt/beta-catenin signalling pathway is likely to result in tumorigenesis of hepatoblastoma. The nuclear and intra-cytoplasmic accumulations of beta-catenin correlate with the likely prognosis of the disease. Nuclear expression of beta catenin is associated with a shorter survival, higher stage, and seen in embryonal/undifferentiated types. To study the expression of beta-catenin in hepatoblastoma by immunohistochemistry and correlate it with the tumour histology and survival outcome. This is a retrospective study of 11 children over a period of 5 years with the diagnosis of hepatoblastoma. These children underwent partial hepatectomy or liver transplantation at the Department of Paediatric Surgery. The clinical, histological and survival data were collected. Immunohistochemical analysis with beta-catenin was done and analysed. Mean birth weight of the children was 2.75kg.63.6% had an epithelial type of histology.Beta catenin expression by IHC was studied in 11 cases and found to be positive in 4 cases. Nuclear positivity was noted in 2/4 cases of embryonal type and Cytoplasmic and membranous positivity was seen in the other 2/4 cases. Normal liver showed a membranous pattern of positivity in one case. Negative staining was seen in 6 out of 11 cases. Beta catenin is considered to be an useful tool for assessing the prognosis of patients with hepatoblastoma and its expression is associated with a poor survival outcome. There are no validated biomarkers for prognosis so far. However, larger studies incorporating molecular profiling is warranted to establish prognostic factors for planning effective treatment strategies.

Corded and Hyalinized and Spindled Endometrioid Endometrial Carcinoma: A Clinicopathologic and Molecular Analysis of 9 Tumors Based on the TCGA Classifier.

Corded and hyalinized and spindled carcinomas are rare variants of endometrioid carcinoma (EC) characterized by cords of low-grade epithelial cells (±spindle cells) within a hyalinized stroma or spindled epithelial cells, respectively, that merge with conventional low-grade EC. Due to their "biphasic" morphology, these tumors are often misdiagnosed as carcinosarcoma. The clinicopathologic features including mismatch repair protein (PMS2 and MSH6) and p53 immunohistochemical expression and POLE mutational status of 9 corded and hyalinized and spindled endometrial ECs were evaluated and classified into The Cancer Genome Atlas (TCGA) based molecular subgroups. Beta-catenin immunohistochemistry was performed as a surrogate for CTNNB1 mutational status. The mean age at diagnosis was 49 years (range: 34 to 68 y) with staging information available for 6 patients: stage IA (n=1), stage IB (n=1), stage II (n=2), stage IIIA (n=1), stage IIIC1 (n=1). A prominent corded and hyalinized component was present in 7 ECs comprising 15% to 80% of the tumor with a minor (5% to 15%) spindled morphology in 5. Two additional tumors were composed of a low-grade spindled component comprising 25% to 30% of the neoplasm. Tumors were grade 1 (n=3), grade 2 (n=5), and grade 2 to 3 (n=1) and squamous differentiation was identified in 8/9. All tumors had preserved expression of mismatch repair proteins with 8 showing a p53 wild-type phenotype including the grade 2 to 3 EC; 1 grade 2, stage IB tumor exhibited a mutant pattern of expression. All (n=7) but 1 tumor demonstrated nuclear beta-catenin expression in the glandular, squamous, and corded or spindled components. POLE exonuclease domain mutations were absent in all tumors. Based on our findings, corded and hyalinized EC and EC with spindle cells are usually low grade, low stage, and present at a younger age and exhibit squamous differentiation at an increased frequency compared to typical EC. Unlike carcinosarcomas, which frequently harbor TP53 mutations, these tumors usually exhibit wild-type p53 and nuclear beta-catenin expression, indicative of underlying CTNNB1 mutations. According to the TCGA subgroups of endometrial carcinoma, the majority of corded and hyalinized and spindled EC appear to fall into the copy number low ("no specific molecular profile") subgroup.

Immunohistochemical assessment of MMR Proteins, BRAF Mutation and Beta-Catenin in Colorectal Carcinoma in Egypt

We conduct this study to investigate the prevalence of dMMR, BRAFV600E mutation and nuclear BetaCatenin among Egyptian CRC cases and correlate results with clinico-pathological parameters and survival.Immunohistochemical assessment of MMR, BRAF and Beta-Catenin was carried out on 83 CRC cases.dMMR, BRAFV600E mutation and nuclear Beta-Catenin expression were identified in (48.2%), (20.5%)and(4.8%)of cases. For MMR and BRAF, none of the clinicopathologic parameters were significantlycorrelated with their status. Despite that the 5-year PFS was slightly better in dMMR tumors than pMMRtumors; yet, the statistical difference could not be verified. BRAF mutation had no prognostic impact onOS and PFS. The smaller number of Beta-Catenin positive tumors precluded the drawing of definitiveconclusion concerning its prognostic role.

Expression of Beta-Catenin in Colorectal Carcinoma and its Association with Various Clinicopathological Parameters

Introduction: Colorectal Carcinoma (CRC) is the third most commonly diagnosed cancer and the second leading cause of cancer related mortality globally. It is a source of concern for researchers worldwide and hence, a lot of emphasis is being given towards early detection and targeted drug therapy to improve the survival rate. Aim: To study the expression of beta-catenin in colonic polyps, adenomas and CRC and to associate beta-catenin expression with various clinicopathological features. Materials and Methods: This was a prospective cross-sectional study conducted in the Department of Pathology, Kalinga Institute of Medical Sciences, Bhubaneswar, Odisha, India from September 2018 to August 2020. Colonoscopic biopsies, mucinous carcinoma and poorly preserved tissue were excluded. Histopathological study and Immunohistochemistry evaluation of beta-catenin was done. Statistical analysis was done by using appropriate tests. A p-value of less than 0.05 was taken as statistically significant. Results: Out of 80 cases, 40 cases were benign lesions Non neoplastic polyp and adenoma) and 40 cases were adenocarcinoma. It was observed that benign lesions had maximum cases with preserved membranous expression (36/40) and very few cases (4/40) showed cytoplasmic expression of beta-catenin. But in carcinoma, high cytoplasmic expression was seen in 20/40 (50%) whereas 8/40 (20%) cases had nuclear positivity. Membranous beta-catenin expression was significantly higher in benign lesions than in the malignant lesions (IS:8.75±3.09 versus 4.30±2.70) respectively; (p<0.0001). But cytoplasmic beta-catenin expression was low in benign lesion as compared to malignant lesion (IS: 2.07±3.46 versus 5.35±3.14), respectively; (p<0.0001). However, nuclear beta-catenin expression was extremely low in benign lesions than in malignant lesions (0.08±0.47 versus 1.90±3.49), respectively; (p=0.0016), this difference was statistically significant. Conclusion: The present study demonstrates the change in beta-catenin expression with gradual transition from predominantly membranous pattern to cytoplasmic or nuclear as we progress from normal colorectal tissues to polyps, benign premalignant lesions and malignant neoplasms. This property of beta-catenin helps in determining malignant potential of various premalignant neoplasms of large intestine which in turn helps in initiating early prophylactic treatment.

Nuclear Beta-Catenin Expression in Endometrioid Intraepithelial Neoplasia (Atypical Hyperplasia) Does Not Predict Carcinoma on Subsequent Hysterectomy

Beta-catenin (BC) mutations are associated with a high risk of recurrence in otherwise low-grade, early-stage uterine endometrioid adenocarcinomas. Recent literature suggests nuclear BC expression by immunohistochemistry is highly sensitive and specific for BC mutations. The significance of BC expression in endometrioid intraepithelial neoplasia (EIN/atypical hyperplasia) and its relationship to altered differentiation patterns in EIN has yet to be fully explored. Cases meeting current diagnostic criteria for EIN based on H&E examination were obtained from 2 institutions (years 1999-2014). Patterns of altered differentiation (eg, tubal, squamous morular metaplasia, mucinous, secretory) were noted. Representative blocks were stained for BC, and expression patterns recorded. Follow-up and demographic data was obtained from the electronic medical record. Ninety-six cases were included (84 biopsies, 12 hysterectomies). BC nuclear expression was identified in 41 cases (42.7%), with 33 of 41 demonstrating foci of nonmorular BC staining. BC staining in any component of EIN was not significantly associated with the presence of carcinoma on subsequent hysterectomy (P=0.79). When restricting to nonmorular BC, the results were the same (P=0.56). Cases with tubal differentiation were significantly less likely to demonstrate nonmorular BC than cases with no specific pattern of differentiation (P<0.01). EIN frequently demonstrates BC nuclear positivity, especially in cases without tubal differentiation. BC nuclear expression in EIN does not appear to be associated with an increased likelihood of carcinoma on subsequent hysterectomy. Our results do not support routine use of BC immunohistochemistry as a prognostic biomarker in cases of EIN.

Quercetin treatment reduces the severity of renal dysplasia in a beta-catenin dependent manner.

Renal dysplasia, the major cause of childhood renal failure, is characterized by defective branching morphogenesis and nephrogenesis. Beta-catenin, a transcription factor and cell adhesion molecule, is markedly increased in the nucleus of kidney cells in human renal dysplasia and contributes to its pathogenesis by altering target genes that are essential for kidney development. Quercetin, a naturally occurring flavonoid, reduces nuclear beta-catenin levels and reduces beta-catenin transcriptional activity. In this study, we utilized wild type and dysplastic mouse kidney organ explants to determine if quercetin reduces beta-catenin activity during kidney development and whether it improves the severity of renal dysplasia. In wild type kidney explants, quercetin treatment resulted in abnormal branching morphogenesis and nephrogenesis in a dose dependent manner. In wild type embryonic kidneys, quercetin reduced nuclear beta-catenin expression and decreased expression of beta-catenin target genes Pax2, Six2, and Gdnf, which are essential for kidney development. Our RDB mouse model of renal dysplasia recapitulates the overexpression of beta-catenin and histopathological changes observed in human renal dysplasia. RDB kidneys treated with quercetin resulted in improvements in the overall histopathology, tissue organization, ureteric branching morphogenesis, and nephrogenesis. Quercetin treatment also resulted in reduced nuclear beta-catenin and reduced Pax2 expression. These improvements were associated with the proper organization of vimentin, NCAM, and E-cadherin, and a 45% increase in the number of developing and maturing nephrons. Further, our results show that in human renal dysplasia, beta-catenin, vimentin, and e-cadherin also have abnormal expression patterns. Taken together, these data demonstrate that quercetin treatment reduces nuclear beta-catenin and this is associated with improved epithelial organization of developing nephrons, resulting in increased developing nephrons and a partial rescue of renal dysplasia.

Downregulation of beta-catenin in chemo-tolerant TNBC through changes in receptor and antagonist profiles of the WNT pathway: Clinical and prognostic implications.

In approximately 30% of triple-negative breast cancer (TNBC) patients a complete pathological response is achieved. However, after neo-adjuvant chemotherapy treatment (NACT) residual tumour cells can be intrinsically resistant to chemotherapy. In this study, associations of the WNT/beta-catenin pathway with chemo-tolerance of NACT treated TNBC patients were compared to that of pre-treatment TNBC patients. Expression analyses were performed in both pre-treatment and NACT treated TNBC samples using immunohistochemistry and qRT-PCR, along with DNA copy number variation (CNV) and promoter methylation analyses to elucidate the mechanism(s) underlying chemo-tolerance. In addition, in vitro validation experiments were performed in TNBC cells followed by in vivo clinicopathological correlation analyses. A reduced expression (41.1%) of nuclear beta-catenin together with a low proliferation index was observed in NACT samples, whereas a high expression (59.0%) was observed in pre-treatment samples. The reduced nuclear expression of beta-catenin in the NACT samples showed concordance with reduced expression levels (47-52.9%) of its associated receptors (FZD7 and LRP6) and increased expression levels (35.2-41.1%) of its antagonists (SFRP1, SFRP2, DKK1) compared to those in the pre-treatment samples. The expression levels of the receptors showed no concordance with its respective gene copy number/mRNA expression statuses, regardless treatment. Interestingly, however, significant increases in promoter hypomethylation of the antagonists were observed in the NACT samples compared to the pre-treatment samples. Similar expression patterns of the antagonists, receptors and beta-catenin were observed in the TNBC-derived cell line MDA-MB-231 using the anthracyclines doxorubicin and nogalamycin, suggesting the importance of promoter hypomethylation in chemotolerance. NACT patients showing reduced receptor and/or beta-catenin expression levels and high antagonist expression levels exhibited a comparatively better prognosis than the pre-treatment patients. Our data suggest that reduced nuclear expression of beta-catenin in NACT TNBC samples, due to downregulation of its receptors and upregulation of its antagonists through promoter hypomethylation of the WNT pathway, plays an important role in chemo-tolerance.

Combined hepatoblastoma and yolk sac tumor of the liver

A 6-year-old patient was admitted to the Petrovsky National Research Center of Surgery in Moscow, diagnosed with hepatoblastoma (HB) of the right lobe of the liver and after undergoing 4 cycles of SIOPEL (super PLADO) pre-operative chemotherapy. An immunohistochemistry test, performed after liver resection, revealed a rare combination of mixed epithelial and mesenchymal hepatoblastoma and yolk sac tumor. The epithelial component of HB consisted of highly differentiated fetal cells, while the mesenchymal component consisted of osteoid. The morphological structure of the second lesion corresponded to yolk sac tumor. Both tumors had regressive changes conditioned by chemotherapy: these changes were most pronounced in HB. In the highly differentiated fetal component of HB it was possible to detect a weak focal perinuclear alpha-fetoprotein expression, HepPar expression, membranous expression of beta-catenin and diffuse glutamine synthetase expression. Mitotic figures were not determined. The node of the yolk sac tumor had the characteristic histological structure of an endodermal sinus tumor with a hepatoid component. In the main tumor node and its nodular elements in the fibrovascular stroma it was possible to identify alpha-fetoprotein expression, CD34, nuclear and cytoplasmic expression of beta-catenin, CDX2, as well as a rare expression of PLAP and multi-cytokeratin, and mitotic activity was high (21 in 10 high power fields, 400x magnification). In the existing literature available to us, there is only one observation of combined hepatoblastoma and yolk sac tumor. Parents patients agreed to use personal data, including the fotos, in research and publications.

Immunohistochemical analysis of beta-catenin, E-cadherin and p53 in canine gastrointestinal epithelial tumors.

Wnt/beta-catenin signaling, E-cadherin and p53 reportedly play important roles in the development and/or progression of human gastrointestinal cancer. The present study evaluated the roles of beta-catenin, E-cadherin and p53 in canine gastrointestinal tumors. Endoscopic biopsy or surgically resected samples, a total of 131, including 38 gastric, 13 small intestinal and 80 large intestinal tumors, were obtained from 95 dogs. Those specimens were examined pathologically. Immunohistochemically, nuclear beta-catenin expression was found in 88% (42/48) of polypoid type adenocarcinomas. Most cases of non-polypoid type adenocarcinomas lacked nuclear expression of beta-catenin with the exception of one case (6%, 1/17). Nuclear beta-catenin expression was not observed in signet ring cell carcinomas (0/15), mucinous adenocarcinomas (0/7) and undifferentiated carcinomas (0/4). The findings indicate that nuclear translocation of beta-catenin is closely related to the development of polypoid type adenocarcinomas but not that of non-polypoid type malignant tumors. The immunoreactivity of E-cadherin for tumor cells tended to decline overall in most of cases including benign tumors. Significant immunoreactivity for p53 was not found in 61% of tumors examined (80/131), including malignant tumors (63%, 57/91), while intense p53-immunoreactivity was rarely found in a few cases of malignant tumors (8%, 7/91). We could not conclude clearly significant correlations between histopathological tumor types and immunohistochemical results of E-cadherin or p53. This paper indicates the importance of the nuclear translocation of beta-catenin for the tumorigenesis of canine intestinal polypoid type adenocarcinomas, especially in the colorectum.

Multinucleate cell angiohistiocytoma: A clinicopathologic study of 62 cases and proposed diagnostic criteria.

Multinucleate cell angiohistiocytoma (MCAH) is an uncommon and likely underdiagnosed entity that is thought to be of vascular and fibrohistiocytic origin. We retrospectively reviewed all cases diagnosed as MCAH at the Yale Medicine Dermatopathology laboratory between 1 January 1990 and 1 September 2018. Sixty-two cases were retained. We performed immunohistochemistry on the ten most inflamed lesions found and assessed for a possible alteration within the Wnt/ß-catenin signaling pathway, involved in follicular induction in dermatofibroma. We subsequently established histologic diagnostic criteria to differentiate MCAH from its mimickers. MCAH affected both genders equally. The hands or fingers were affected in 51.6% of cases. We found the most specific histologic criteria to be: (a) presence of odd multinucleated fibroblasts, (b) presence of superficial parallel fibrosis, (c) presence and thickening of superficial papillary dermal vessels, and (d) absence of perifollicular fibrosis. As for immunoreactivity, we found positivity to CD138, CD163, and CD117 in the mononuclear inflammatory infiltrate. There was no histopathologic evidence of follicular induction, as can be seen in dermatofibromas, and no expression of nuclear beta-catenin as seen in dermatofibromas with follicular induction. This large case series establishes MCAH as a distinct clinical and histopathologic entity.

Quercetin as a Novel Treatment for Developmental Abnormalities of the Kidney

Renal dysplasia is the abnormal development of the kidney and is the leading cause of chronic kidney disease and kidney failure in children. Despite this, there is no cure. Invasive symptom management such as dialysis and kidney transplants have significant adverse effects. Normal kidney development involves the interaction between three cell types: ureteric epithelium, metanephric mesenchyme, and renal stroma. The ureteric epithelium undergoes branching morphogenesis to form the collecting system, and the metanephric mesenchyme undergoes nephrogenesis to form the nephrons. The renal stroma provides structural support to the developing kidney and regulates proper branching morphogenesis and nephrogenesis. Beta‐catenin is a transcription factor essential for normal branching morphogenesis and nephrogenesis. In human renal dysplasia, beta‐catenin levels are markedly increased in the nucleus of the stroma, mesenchyme and epithelium. Our findings from transgenic mouse models show that elevated levels of beta‐catenin in the nucleus cause dysregulation of genes leading to abnormal branching morphogenesis and nephrogenesis, resulting in renal dysplasia. Our objective is to inhibit beta‐catenin transcriptional activity in the kidney and determine its effects on normal and dysplastic kidney development. Quercetin is a flavonoid that inhibits beta‐catenin activity and was effective in reducing beta‐catenin levels that resulted to improved outcomes in different cancer types and in kidney fibrosis. We tested if Quercetin alters beta‐catenin activity during normal kidney development. Wild‐type embryonic day 13.5 mouse kidneys were cultured in growth medium supplemented with 0uM (control), 40uM, 80uM, and 160uM Quercetin for 48 hours. A dose‐dependent disruption in branching morphogenesis and nephrogenesis was observed by performing immunofluorescence for cytokeratin, Pax2, and Six2. In addition, quantitative reverse‐transcriptase PCR (qRT‐PCR) showed a disrupted expression of beta‐catenin target genes essential for kidney development (Pax2, Wnt4, and GDNF). Consistent with these findings, immunohistochemistry for beta‐catenin demonstrated that Quercetin reduced nuclear beta‐catenin expression and increased cytoplasmic expression in a dose‐dependent manner. Next, to determine if Quercetin rescues renal dysplasia, we utilized transgenic mice models that over‐express beta‐catenin specifically in the kidney stroma (Foxd1;B‐catGOFs), or in the mesenchyme, stroma, and ureteric epithelium (Rarb2;B‐catGOFsmu). Both of these animal models have severe renal dysplasia characterized by disorganized branching morphogenesis and disrupted nephrogenesis. Immunofluorescence for cytokeratin and Pax2 showed that in‐vitro treatment of embryonic day 13.5 dysplastic kidneys with 40uM Quercetin resulted in a markedly improved kidney with improved branching morphogenesis and nephrogenesis, and closely resembles wild‐type kidney development. Our findings demonstrate that Quercetin reduces beta‐catenin activity in normal and dysplastic kidneys, reduces the transcription of genes that play central roles in kidney development, and resulted to a reduced severity of renal dysplasia.Support or Funding InformationNSERC, CIHR and KFOCThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.