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Abstract Overexpression of the EPS15 Homology Domain containing 1 (EHD1) protein has been linked to tumorigenesis but whether its core function as a regulator of intracellular traffic of cell surface receptors plays a role in oncogenesis remains unknown. We establish that EHD1 is overexpressed in Ewing sarcoma (EWS), with high EHD1 mRNA expression specifying shorter patient survival. ShRNA-knockdown and CRISPR-knockout with mouse Ehd1 rescue established a requirement of EHD1 for tumorigenesis and metastasis. RTK antibody arrays identified IGF-1R as a target of EHD1 regulation in EWS. Mechanistically, we demonstrate a requirement of EHD1 for endocytic recycling and Golgi to plasma membrane traffic of IGF-1R to maintain its surface expression and downstream signaling. Conversely, EHD1 overexpression-dependent exaggerated oncogenic traits require IGF-1R expression and kinase activity. Our findings define the RTK traffic regulation as a proximal mechanism of EHD1 overexpression-dependent oncogenesis that impinges on IGF-1R in EWS, supporting the potential of IGF-1R and EHD1 co-targeting.

Abstract Background Osteosarcoma is the most common primary malignant tumour of bone occurring in children and young adolescents and is characterised by complex genetic and epigenetic changes. The miRNA miR-486-5p has been shown to be downregulated in osteosarcoma and in cancer in general. Results To investigate if the mir-486 locus is epigenetically regulated, we integrated DNA methylation and miR-486-5p expression data using cohorts of osteosarcoma cell lines and patient samples. A CpG island in the promoter of the ANK1 host gene of mir-486 was shown to be highly methylated in osteosarcoma cell lines as determined by methylation-specific PCR and direct bisulfite sequencing. High methylation levels were seen for osteosarcoma patient samples, xenografts and cell lines based on quantitative methylation-specific PCR. 5-Aza-2′-deoxycytidine treatment of osteosarcoma cell lines caused induction of miR-486-5p and ANK1, indicating common epigenetic regulation in osteosarcoma cell lines. When overexpressed, miR-486-5p affected cell morphology. Conclusions miR-486-5p represents a highly cancer relevant, epigenetically regulated miRNA in osteosarcoma, and this knowledge contributes to the understanding of osteosarcoma biology.

Lung metastasis is the major cause of death in osteosarcoma patients. However, molecular mechanisms underlying this metastasis remain poorly understood. To identify key molecules related with pulmonary metastasis of pediatric osteosarcomas, we analyzed high‐throughput miRNA expression in a cohort of 11 primary tumors and 15 lung metastases. Results were further validated with an independent cohort of 10 primary tumors and 6 metastases. In parallel, we performed immunohistochemical analysis of activated signaling pathways in 36 primary osteosarcomas. Only phospho‐AKT associated with lower overall survival in primary tumors, supporting its role in osteosarcoma progression. CTNNB1 expression also associated with lower overall survival but was not strong enough to be considered an independent variable. Interestingly, miR‐200c was overexpressed in lung metastases, implicating an inhibitory feed‐back loop to PI3K‐AKT. Moreover, transfection of miR200c‐mimic in U2‐OS cells reduced phospho‐AKT levels but increased cellular migration and proliferation. Notably, miR‐200c expression strongly correlated with miR‐141 and with the osteogenic inhibitor miR‐375, all implicated in epithelial to mesenchymal transition. These findings contrast epithelial tumors where reduced miR‐200c expression promotes metastasis. Indeed, we noted that osteosarcoma cells in the lung also expressed the epithelial marker CDH1, revealing a change in their mesenchymal phenotype. We propose that miR‐200c upregulation occurs late in osteosarcoma progression to provide cells with an epithelial phenotype that facilitates their integration in the metastatic lung niche. Thus, our findings identify phospho‐AKT in the primary tumor and miR‐200c later during tumor progression as prognostic molecules and potential therapeutic targets to prevent progression and metastasis of pediatric osteosarcomas.

Objetivo: Caracecterizar morfológica e inmunohitoquimicamente el carcinoma apocrino mamamario. Materiales y métodos: Este estudio toma 24 casos diagnosticados como carcinomas apocrinos o con rasgos apocrinos, clasificándolos como puros y mixtos, reconociendo la presencia de componentes in situ asociados, para evaluar la expresión inmunohistoquímica del receptor de andrógenos (AR), receptor de estrógenos (ER), receptor de progesterona (PR), gross cistyc disease proteína (GCDFP-15), BCL2,KI67 y ERB-2 tanto en las áreas infiltrantes como intraepiteliales, estudiando adicionalmente la amplificación génica del ERB-2 en el cromosoma 17 por métodos de FISH. Resultados: Los tumores clasificados como puros correspondieron a 11 casos que expresan la siguiente positividad inmunohistoquímica en las áreas infiltrativas: AR (100%), ER (18%), PR (18%), GCDFP (63%), BCL2 (54%), KI67 (28%) y ERB-2(28%) con una positividad de GCDFP-15(100%) en la áreas in situ. Los tumores mixtos correspondientes a 13 casos mostraron la siguiente positividad inmunohistoquímica: AR (58%), ER (46%), PR (46%), GCDFP-15 (50%), BCL2 (33%), KI67 (58%) y ERB-2(16%), con una positividad de GCDFP-15 (100%) en las áreas in situ. Las áreas in situ expresan GCDFP-15 en todos los casos con una reducción de la expresión en las zonas de infiltración del mismo al 63 y 50% en los tumores puros y mixtos, respectivamente. Conclusiones: Los carcinomas mamarios apocrinos puros deben ser distinguidos de los mixtos mediante un examen morfológico detallado y por su perfil inmunohistoquímico (AR+, ER-, PR-/GCDFP+, BCL2+/-, KI67-, ERB2/-).

The Ewing sarcoma family of tumors (EFT) is a group of highly malignant small round blue cell tumors occurring in children and young adults. We report here the largest genomic survey to date of 101 EFT (65 tumors and 36 cell lines). Using a combination of whole genome sequencing and targeted sequencing approaches, we discover that EFT has a very low mutational burden (0.15 mutations/Mb) but frequent deleterious mutations in the cohesin complex subunit STAG2 (21.5% tumors, 44.4% cell lines), homozygous deletion of CDKN2A (13.8% and 50%) and mutations of TP53 (6.2% and 71.9%). We additionally note an increased prevalence of the BRCA2 K3326X polymorphism in EFT patient samples (7.3%) compared to population data (OR 7.1, p = 0.006). Using whole transcriptome sequencing, we find that 11% of tumors pathologically diagnosed as EFT lack a typical EWSR1 fusion oncogene and that these tumors do not have a characteristic Ewing sarcoma gene expression signature. We identify samples harboring novel fusion genes including FUS-NCATc2 and CIC-FOXO4 that may represent distinct small round blue cell tumor variants. In an independent EFT tissue microarray cohort, we show that STAG2 loss as detected by immunohistochemistry may be associated with more advanced disease (p = 0.15) and a modest decrease in overall survival (p = 0.10). These results significantly advance our understanding of the genomic and molecular underpinnings of Ewing sarcoma and provide a foundation towards further efforts to improve diagnosis, prognosis, and precision therapeutics testing.

Driven by genomic somatic variation, tumour tissues are typically heterogeneous, yet unbiased quantitative methods are rarely used to analyse heterogeneity at the protein level. Motivated by this problem, we developed automated image segmentation of images of multiple biomarkers in Ewing sarcoma to generate distributions of biomarkers between and within tumour cells. We further integrate high dimensional data with patient clinical outcomes utilising random survival forest (RSF) machine learning. Using material from cohorts of genetically diagnosed Ewing sarcoma with EWSR1 chromosomal translocations, confocal images of tissue microarrays were segmented with level sets and watershed algorithms. Each cell nucleus and cytoplasm were identified in relation to DAPI and CD99, respectively, and protein biomarkers (e.g. Ki67, pS6, Foxo3a, EGR1, MAPK) localised relative to nuclear and cytoplasmic regions of each cell in order to generate image feature distributions. The image distribution features were analysed with RSF in relation to known overall patient survival from three separate cohorts (185 informative cases). Variation in pre-analytical processing resulted in elimination of a high number of non-informative images that had poor DAPI localisation or biomarker preservation (67 cases, 36%). The distribution of image features for biomarkers in the remaining high quality material (118 cases, 104 features per case) were analysed by RSF with feature selection, and performance assessed using internal cross-validation, rather than a separate validation cohort. A prognostic classifier for Ewing sarcoma with low cross-validation error rates (0.36) was comprised of multiple features, including the Ki67 proliferative marker and a sub-population of cells with low cytoplasmic/nuclear ratio of CD99. Through elimination of bias, the evaluation of high-dimensionality biomarker distribution within cell populations of a tumour using random forest analysis in quality controlled tumour material could be achieved. Such an automated and integrated methodology has potential application in the identification of prognostic classifiers based on tumour cell heterogeneity.

OBJECTIVE:Growing evidences indicate that the histone methyltransferase EZH2 (enhancer of zeste homolog 2) may be an appropriate therapeutic target in some tumors. Indeed, a high expression of EZH2 is correlated with poor prognosis and metastasis in many cancers. In addition, 3-Deazaneplanocin A (DZNep), an S-adenosyl-L homocysteine hydrolase inhibitor which induces EZH2 protein depletion, leads to cell death in several cancers and tumors. The aim of this study was to determine whether an epigenetic therapy targeting EZH2 with DZNep may be also efficient to treat chondrosarcomas. METHODS:EZH2 expression was determined by immunohistochemistry and western-blot. Chondrosarcoma cell line CH2879 was cultured in the presence of DZNep, and its growth and survival were evaluated by counting adherent cells periodically. Apoptosis was assayed by cell cycle analysis, Apo2.7 expression using flow cytometry, and by PARP cleavage using western-blot. Cell migration was assessed by wound healing assay. RESULTS:Chondrosarcomas (at least with high grade) highly express EZH2, at contrary to enchondromas or chondrocytes. In vitro, DZNep inhibits EZH2 protein expression, and subsequently reduces the trimethylation of lysine 27 on histone H3 (H3K27me3). Interestingly, DZNep induces cell death of chondrosarcoma cell lines by apoptosis, while it slightly reduces growth of normal chondrocytes. In addition, DZNep reduces cell migration. CONCLUSION:These results indicate that an epigenetic therapy that pharmacologically targets EZH2 via DZNep may constitute a novel approach to treat chondrosarcomas.

В останні роки в науковій пресі з'явилисm численні дані про молекулярну біологію раку молочної залози. У зв'язку з цим, гістологічна класифікація ВООЗ (2004 ) виявилась застарілою. Сьогодні більшість відомостей про прогноз, лікування та клінічний результат захворювання грунтується на результатах молекулярних і біологічних досліджень останніх років. Розглянуто сучасні підходи до питань гістопатологічної діагностики раку молочної залози на основі нових технологій. Обговорено рекомендації з імуногістохімічного тестування рецепторів естрогенів і прогестерону , а також рецепторів до епідермального фактора росту 2 (HERB2) у зразках пухлинної тканини. Запропоновано алгоритм оцінки отриманих даних, включаючи позитивні, спірні й негативні результати, що стосуються експресії білків HERB2 і ампліфікації гена. На основі характеру експресії генів, вивченого за технологією мікрочіпів з подальшою ієрархічної кластеризацією РНК нативної тканини, виділено нові генетичні профілі пухлини. Показано можливість застосування методів імуногістохімії в тканинах, залитих у парафін. Рекомендовано імуногістохімічну панель для діагностики наступних типів раку молочної залози: люмінальної А (Luminal А) , люмінальної В (Luminal В), базальноподібний і HER2/neu.Заключна частина роботи присвячена варіантам раку молочної залози з генетичною сприйнятливістю до BRCA1 і 2. Такі пухлини вкрай агресивні, характеризуються високим ступенем злоякісності і мають несприятливий прогноз. Проаналізовано нові підходи до терапії захворювання.