mRNA expression profiling of phyllodes tumours of the breast: identification of genes important in the development of borderline and malignant phyllodes tumours

Are both distinct epithelial and stromal cells molecular analysis from phyllodes tumors versus fibroadenoma components affected in breast fibroepithelial progression?

PURPOSE

To determine molecular events involved in the tumorigenesis of phyllodes tumors (PT) and the role of each stromal (SC) and epithelial (EC) cell.

METHODS

Frozen breast samples enriched with epithelial and stromal cells from three fibroadenomas and 14 PT were retrieved and laser microdissected. Sanger and polymerase chain reaction-based sequencing of exon 2 MED12 and TERT promoter hotspot mutations were performed; 44K microarray platform was used to analyze gene expression.

RESULTS

All three fibroadenomas (FAs) presented mutations in MED12, but not in TERT, whose mutation was observed in five of the 14 PTs. EC and SC of each affected tumor displayed identical alterations. Of the total differentially expressed genes (DEG) (EC = 1,543 and SC = 850), 984 were EC-eDEGs and 291 were SC-eDEGs. We found a high similarity of diseases and functions enriched by both cell types, but dissimilarity in the number of enriched canonical pathways. Three signaling canonical pathways overlapping with EC and SC were predicted to be activated in one cell type and inactivated in the other, while no overlap in eDEGs was assigned to them. We also identified 13 EC-eDEGs and five SC-eDEGs enriched networks, in which the SC-eDEGs were able to segregate FA from PT samples.

CONCLUSIONS

Identical TERT mutations from both SC and ES origins might affect the PTs tumorigenesis. Gene expression differences suggest coordinated molecular processes between these components with determinant differences acquired by SC, able to fully distinguish PTs from FAs lesions.

An integrative approach for exploring the nature of fibroepithelial neoplasms

BACKGROUND

Malignant phyllodes tumour (MPT) is a rare breast malignancy with epithelial and mesenchymal features. Currently, there are no appropriate research models or effective targeted therapeutic approaches for MPT.

METHODS

We collected fresh frozen tissues from nine patients with MPT and performed whole-exome and RNA sequencing. Additionally, we established patient-derived xenograft (PDX) models from patients with MPT and tested the efficacy of targeting dysregulated pathways in MPT using the PDX model from one MPT.

RESULTS

MPT has unique molecular characteristics when compared to breast cancers of epithelial origin and can be classified into two groups. The PDX model derived from one patient with MPT showed that the mouse epithelial component increased during tumour growth. Moreover, targeted inhibition of platelet-derived growth factor receptor (PDGFR) and phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) by imatinib mesylate and PKI-587 showed in vivo tumour suppression effects.

CONCLUSIONS

This study revealed the molecular profiles of MPT that can lead to molecular classification and potential targeted therapy, and suggested that the MPT PDX model can be a useful tool for studying the pathogenesis of fibroepithelial neoplasms and for preclinical drug screening to find new therapeutic strategies for MPT.

Case Report: Mitral valve obstruction by metastatic malignant phyllodes tumor

Cardiac metastases are rare. Herein, we report a case of a 37-year-old female patient with a history of borderline breast phyllodes tumor (PT) treated by surgery, admitted to our department for concomitant cardiac and pulmonary metastases of malignant PT. Cardiac metastasis occurred through direct extension from pulmonary metastasis to the left atrium via the right inferior pulmonary vein, causing severe mitral valve obstruction. Although the total surgical removal of metastases, the patient had a huge relapse of the mediastinal metastasis resulting in her death.

Circular RNA expression profiles in human bronchial epithelial cells treated with beryllium sulfate

Circular RNAs (circRNAs), is a novel type of endogenous non-coding RNAs (ncRNAs) participated in the pathogenesis of many diseases. Beryllium is one of the carcinogenesis elements. However, the mechanism and function of circRNAs in human bronchial epithelial cells (16HBE) induced by beryllium sulfate (BeSO₄) was rarely reported. Therefore, the high-throughput RNA sequencing analysis was performed to detect the circRNA profiles between control groups and BeSO₄-induced groups. Furthermore, circRNA-miRNA-mRNA network, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and PPI network analysis were used for bioinformatics analysis. CircRNA sequencing analysis revealed that 36 circRNAs were up-regulated and 35 circRNAs were down-regulated in the BeSO₄-exposed groups. The selected circRNAs were verified by real-time fluorescent quantitative PCR (qRT-PCR). Hsa_circ_0004214 and hsa_circ_0003586 were validated to be up-regulated, hsa_circ_0047958, hsa_circ_0001944, and hsa_circ_0008982 were down-regulated. The circRNA-miRNA-mRNA network annotated the key signaling pathway including cellular senescence, TNF signaling pathway, NF-kappa B signaling pathway, HIF-1 signaling pathway, and Hippo signaling pathway. The PPI network indicated the most circRNAs might participate in the BeSO₄ toxicity by acting as a sponge for the miR-663b through JAK-STAT signaling pathway. In summary, our study suggests that circRNAs may play roles in the mechanism of beryllium toxicity.

Epithelial-mesenchymal transition and cancer stem cell interactions in breast phyllodes tumours: immunohistochemical evaluation of EZH2, EZR, HMGA2, CD24 and CD44 in correlation with outcome analysis

AIM

Phyllodes tumours (PTs) categorised as benign, borderline and malignant, account for 1% of all breast tumours. Histological assessment does not always predict tumour behaviour, hindering determination of the clinical course and management.Epithelial-mesenchymal transition (EMT) is an important process during embryogenesis. Dysregulation of EMT causes loss of cell polarity, decreased intercellular adhesion, increased motility and invasiveness, promoting tumour progression. Similarly, cancer stem cells (CSCs) promote tumour growth, resistance and recurrence. The aim of this study is to evaluate expression of CSC markers; enhancer of zeste homolog 2 (EZH2), CD24 and CD44 and EMT associated proteins; ezrin (EZR) and high-mobility group AT-hook 2 (HMGA2) in PTs.

METHOD

Uing tissue microarray sections, immunohistochemistry was performed on 360 PTs. Epithelial and stromal expressions of EZH2, EZR, HMGA2, CD24 and CD44 were evaluated to assess their impact on disease progression and behaviour in correlation with clinicopathological parameters.

RESULTS

Stromal expression of EZH2, EZR and HMGA2 was observed in 73 (20.3%), 53 (14.7%) and 28 (7.8%) of tumours, epithelial expression in 121 (35.9%), 3 (0.8%) and 351 (97.5%) tumours, respectively. CD24 and CD44 staining was absent in both components.

CONCLUSION

Expression of biomarkers correlated significantly with aggressive tumour traits such as stromal hypercellularity, atypia, mitoses and permeative tumour borders.Stromal expression of EZH2 and EZR shortened disease-free survival and overall survival; HMGA2 expression did not alter patient survival. EZH2 and EZR may thus be useful in predicting PT behaviour.

Bilateral Phyllodes Giant Tumor. A Case Report Analyzed by Array-CGH

The breast phyllodes tumor is a biphasic tumor that accounts for less than of 1% of all breast neoplasms. It is classified as benign, borderline, or malignant, and can mimic benign masses. Some recurrent alterations have been identified. However, a precise molecular classification of these tumors has not yet been established. Herein, we describe a case of a 43-year-old woman that was admitted to the emergency room for a significant bleeding from the breast skin. A voluminous ulcerative mass of the left breast and multiple nodules with micro-calcifications on the right side were detected at a physical examination. A left total mastectomy and a nodulectomy of the right breast was performed. The histological diagnosis of the surgical specimens reported a bilateral giant phyllodes tumor, showing malignant features on the left and borderline characteristics associated with a fibroadenoma on the right. A further molecular analysis was carried out by an array-Comparative Genomic Hybridization (CGH) to characterize copy-number alterations. Many losses were detected in the malignant mass, involving several tumor suppressor genes. These findings could explain the malignant growth and the metastatic risk. In our study, genomic profiling by an array-CGH revealed a greater chromosomal instability in the borderline mass (40 total defects) than in the malignant (19 total defects) giant phyllodes tumor, reflecting the tumor heterogeneity. Should our results be confirmed with more sensitive and specific molecular tests (DNA sequencing and FISH analysis), they could allow a better selection of patients with adverse pathological features, thus optimizing and improving patient's management.

High mobility group A protein-2 as a tumor cancer diagnostic and prognostic marker: a systematic review and meta-analysis

High mobility group A protein-2 (HMGA2) is an architectural transcription factor that binds to the A/T-rich DNA minor groove and is responsible for regulating transcriptional activity of multiple genes indirectly through chromatin change and assembling enhanceosome. HMGA2 is overexpressed in multiple tumor types, suggesting its involvement in cancer initiation and progression, thus, making it an ideal candidate for cancer diagnostic and prognostic. We performed a systematic review to examine the role of HMGA2 as a universal tumor cancer diagnostic and prognostic marker. We used Reporting Recommendations for Tumor Marker Prognostic Studies to systematically search OvidMedline, PubMed, and the Cochrane Library for English language studies, published between 1995 and June 2019. Meta-analysis provided pooled risk estimates and their 95% confidence intervals (CIs) for an association between overall survival and recurrence of cancers for studies with available estimates. We identified 42 eligible studies with a total of 5123 tumor samples in 15 types of cancer. The pooled percentage of HMGA2 gene expression in tumor samples was 65.14%. Meta-analysis showed that cancer patients with HMGA2 positive have significantly reduced survival, compared to patients without HMGA2 gene [pooled-hazard ratio (HR) = 1.85, 95% CI 1.48-2.22]. There was a positive association between cancer patients with HMGA2 overexpression and cancer recurrence though this association did not reach significance (pooled-HR = 1.44, 95% CI 0.80-2.07). Overexpression of HMGA2 was found in 15 types of cancer. There was an association between HMGA2 overexpression with reduced survival of cancer patients. HMGA2 is thus considered a promising universal tumor marker for prognostics.

Morphologic and genetic heterogeneity in breast fibroepithelial lesions-a comprehensive mapping study

Breast fibroepithelial lesions (FELs) encompass the common fibroadenoma (FA) and relatively rare phyllodes tumour (PT); the latter entity is usually classified as benign, borderline or malignant. Intratumoural heterogeneity is frequently present in these tumours, making accurate histologic evaluation challenging. Despite their rarity, PTs are an important clinical problem due to their propensity for recurrence and, in the case of malignant PT, metastasis. Surgical excision is the mainstay of management. Recent work has uncovered myriad genetic alterations in breast FELs. In this study, exome sequencing was performed on seven cases of morphologically heterogeneous breast FELs, including FAs, PTs of all grades, and a case of metaplastic spindle cell carcinoma arising in PT, in order to elucidate their intratumoural genetic repertoire. Gene mutations identified encompassed cell signalling, tumour suppressor, DNA repair and cell cycle regulating pathways. Mutations common to multiple tumour regions generally showed higher variant allele frequency. Frequent mutations included MED12, TP53, RARA and PIK3CA. Histological observations of increased cellular density and pleomorphism correlated with mutational burden. Phylogenetic analyses revealed disparate pathways of possible tumour progression. In summary, histological heterogeneity correlated with genetic changes in breast FELs.

A giant malignant phyllodes tumor of breast post mastectomy with metastasis to stomach manifesting as anemia: a case report and review of literature

BACKGROUND

Phyllodes tumors (PTs) are well known for local recurrence and progression. Less than 10% of these tumors grow larger than 10 cm. Distant metastases have been reported in up to 22% of malignant PTs, with most metastases being discovered in the lungs. PTs of the breast rarely metastasize to the gastrointestinal tract, and reported cases are scarce. To date, a review of the English literature revealed only 3 cases, including our case, of PTs metastasis to stomach.

CASE PRESENTATION

An 82-year-old female patient had 10-year-duration of palpable huge tumor on left breast which was in rapid growth in recent months. Total mastectomy of left breast was performed thereafter, and pathology diagnosis was malignant phyllodes tumor. Adjuvant radiotherapy was suggested while she declined out of personal reasons initially. For PTs recurred locally on left chest wall 2 months later, and excision of the recurrent PTs was performed. She, at length, completed adjuvant radiation therapy since then. Six months later, she was diagnosed of metastasis to stomach due to severe anemia with symptom of melena. Gastrostomy with tumor excision was performed for uncontrollable tumor bleeding.

CONCLUSION

For PTs presenting as anemia without known etiologies, further studies are suggested to rule out possible gastrointestinal tract metastasis though such cases are extremely rare. Management of metastatic gastric tumor from PTs should be done on a case-to-case basis, surgical intervention may be needed if there is persistent active bleeding despite medical treatment. Adjuvant radiotherapy is recommended in borderline and malignant PTs with tumor-free margin < 1 cm and high-risk malignant tumors. Adjuvant chemotherapy or target therapy may be helpful for metastatic PTs. Molecular and genomic techniques may predict clinical outcomes of benign and borderline PTs more precisely.

Radiotherapy with apatinib for recurrence of malignant phyllodes tumor of the breast: A case report

RATIONALE

Malignant phyllodes tumors of the breast are rare, and there are currently no guidelines and a large number of clinical trials to guide the treatment of recurrence tumor. Here we reported a case of radiotherapy with apatinib for the treatment of recurrent malignant phyllodes tumor of the breast.

PATIENT CONCERNS

A 58-year-old patient with massive breast mass was admitted to our hospital. Two months after surgical treatment, the tumor recurred in the chest wall scar.

DIAGNOSES

The histopathologic diagnoses was right breast malignant phyllodes tumor with chondrosarcomas and osteosarcomas in some areas.

INTERVENTIONS

The patient was first treated with surgery. Malignant phyllodes tumor recurred in the chest wall two months after surgery and was treated with radiotherapy and apatinib.

OUTCOMES

With surgery, radiotherapy and apatinib treatment, the patient still died within several months.

LESSONS

Apatinib and radiotherapy failed to obtain good therapeutic effect in the recurrence of breast malignant phyllodes tumor in this case.

Malignant phyllodes tumor with metastases to lung, adrenal and brain: A rare case report

Background

Phyllodes tumors are spectrum of tumors ranging from benign to malignant. Malignant spectrum pose a management challenge for clinicians due to high risks of recurrence and metastasis. Malignant phyllodes tumor with brain, lung and adrenal metastases at the same time is rare.

Case presentation

A 37 years-old unmarried female presented with an ulcerated huge lump in left breast with severe bleeding. Trucut biopsy showed necrosis with spindle cell proliferation with atypia for which she underwent modified radical mastectomy with final diagnosis of malignant phyllodes tumor. Three months after surgery, patient presented with headache, which on further evaluation showed masses in lung, right adrenal and brain.

Conclusion

We presented a rare case of malignant phyllodes tumor with clinical, imaging and histological findings with metastases to multiple sites early in course and poor outcome of the patient despite margin negative resection.

•

Metastatic malignant phyllodes tumor have poor outcome.

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Simultaneous metastasis to brain, lung and adrenal is rare.

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Margin negative resection is feasible even in huge malignant phyllodes tumor.

TMEM119 promotes gastric cancer cell migration and invasion through STAT3 signaling pathway

Objective

TMEM119 is a member of transmembrane proteins family, which is abnormally expressed in human cancers and associated with tumorigenesis. In this study, we focused on the expression of TMEM119 and its role in cell invasion and migration in gastric cancer.

Methods

Real-time polymerase chain reaction, Western blotting, and immunohistochemistry were performed to examine the expression of TMEM119 in gastric cancer tissues and cell lines. After transfection with TMEM119 siRNA or recombined TMEM119-expressing vector, the invasion and migration ability of MKN45 and SGC-7901 cells was measured by transwell assay. The expression of TMEM119, p-STAT3, STAT3, VEGF, MMP2, and MMP9 proteins in SGC-7901 and MKN45 cells treated with TMEM119 siRNA, TMEM119-expressing vector, or AG490 was measured by Western blotting.

Results

We found that higher TMEM119 expression was found in gastric cancer tissues and cell lines and was associated with lower survival rate. TMEM119 knockdown inhibited SGC-7901 cell invasion and migration, along with the expression of p-STAT3, VEGF, MMP2, and MMP9. TMEM119 overexpression promoted MKN45 cell invasion and migration, along with the expression of p-STAT3, VEGF, MMP2, and MMP9. Additionally, AG490 treatment significantly corrected TMEM119-induced MKN45 cell migration and invasion and expression of p-STAT3, VEGF, MMP9, and MMP2 proteins.

Conclusion

The results indicated that TMEM119 promotes gastric cancer cell migration and invasion through activation of STAT3 signaling pathway, and TMEM119 may therefore act as a novel therapeutic target for gastric cancer.

Phyllodes Tumor of the Breast: Ultrasound-Pathology Correlation

OBJECTIVE

The purpose of this study is to evaluate the sonographic and histopathologic features distinguishing benign from borderline and malignant phyllodes tumors.

MATERIALS AND METHODS

The ultrasound examinations of women with pathologically proven phyllodes tumors from 2004 to 2011 were retrospectively reviewed. The sonographic features of benign, borderline, and malignant phyllodes tumors were compared and analyzed using the American College of Radiology's BI-RADS ultrasound lexicon. Fisher exact test and Wilcoxon rank sum test were used for statistical analysis.

RESULTS

Fifty-nine women were included in the study; 28 benign (47%), 19 malignant (32%), and 12 borderline (20%) phyllodes tumors were identified. Significant univariate predictors of increased risk of borderline or malignant phyllodes tumors were patient age greater than 55 years (p = 0.014), irregular lesion shape (p = 0.011), and longest lesion dimension greater than 7 cm (p = 0.0022) at sonography. No significant differences were observed in lesion margins, boundaries, echo patterns, or posterior acoustic features.

CONCLUSION

There is substantial overlap in the sonographic features of benign and borderline or malignant phyllodes tumors. Understanding the clinical and sonographic features of phyllodes tumors may aid the radiologist in predicting biological behavior, including the likelihood of benign versus borderline or malignant phyllodes tumors at pathologic analysis.

Case Report: Metastatic Phyllodes Tumor

This report describes the clinical presentation, imaging findings, and treatment options of a case of metastatic malignant phyllodes.

Phyllodes tumors of the breast in 2 sisters: Case report and review of literature

RATIONALE

Phyllodes tumors (PT) of the breast are rare neoplasm originating from fibroepithelial component. To our knowledge, our report is the first reported case of PT in 2 sisters.

PATIENT CONCERNS

We presented 2 cases of PT of the breast involving in 2 sisters. On physical examination of the younger sister, a firm mass measuring approximately 3 cm in diameter was identified in upper inner quadrant of the right breast. Physical examination of the elder sister revealed a 3 cm lump in upper outer quadrant of the left breast.

DIAGNOSES

Histopathology of the younger sister revealed a malignant PT. The elder sister was diagnosed with borderline PT.

INTERVENTIONS

The younger sister with malignant PT underwent right mastectomy. The elder sister with borderline PT was scheduled for wide resection of the mass in the left breast.

OUTCOMES

After a follow-up of 23 months, no local or distant recurrence was observed.

LESSONS

Our cases indicate that genetic factor may contribute to the risk of PT of the breast. Markers such as p53 and Ki-67 may have some correlation with PT malignancy.

Phyllodes Tumor of the Breast: Histopathologic Features, Differential Diagnosis, and Molecular/Genetic Updates

CONTEXT

-Phyllodes tumor (PT) of the breast is a rare fibroepithelial neoplasm with risks of local recurrence and uncommon metastases. The classification proposed by the World Health Organization for PTs into benign, borderline, and malignant is based on a combination of several histologic features. The differential diagnosis between PT and fibroadenoma and the histologic grading of PT remain challenging. In addition, the molecular pathogenesis of PT is largely unknown.

OBJECTIVE

-To provide an updated overview of pathologic features, diagnostic terminology, and molecular alterations of PT.

DATA SOURCES

-Current English literature related to PT of the breast.

CONCLUSIONS

-Phyllodes tumor shows a wide spectrum of morphology. There are no clearly distinct boundaries between PT and fibroadenoma. Strict histologic assessment of a combination of histologic features with classification can help to achieve the correct diagnosis and provide useful clinical information. The genomic landscapes of PT generated from genomic sequencing provide insights into the molecular pathogenesis of PT and help to improve diagnostic accuracy and identify potential drug targets in malignant PT.

The largest and neglected giant phyllodes tumor of the breast-A case report and literature review

INTRODUCTION

Phyllodes tumours are rare fibro-epithelial lesions. The role of the pathologist in the preoperative diagnosis of phyllodes tumours of the breast is critical to appropriate surgical planning. Wide local excision or mastectomy with adequate margin remains the treatment of choice. Local recurrence occurs in approximately 10- 16.1% of patients (Wei et al., 2014) [1] and distant metastases occurs in 6.3-31% of patients with malignant phyllodes tumours (Wei et al. (2014), Chaney et al., 1998) [1,2] but only in 4% of all phyllodes tumours (Salvador et al., 1989) [3]. Emphasis should be given in early diagnosis and intervention to decrease morbidity and mortality.

Heterologous Liposarcomatous Differentiation in Malignant Phyllodes Tumor is Histologically Similar but Immunohistochemically and Molecularly Distinct from Well-differentiated Liposarcoma of Soft Tissue

Malignant phyllodes tumor (PT) infrequently displays heterologous differentiation, and when present is most often liposarcomatous. We identified five cases of malignant PT with regions identical to well-differentiated liposarcoma (WDLS) of soft tissue and evaluated them for MDM2 and CDK4 gene expression and amplification using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively. Despite indistinguishable morphology all cases of malignant PT with WDLS-like liposarcomatous differentiation were negative for MDM2 and CDK4 IHC and FISH, supporting different underlying pathogenesis.

Malignant phyllodes tumor metastasized to the right ventricle: a case report

Cardiac metastasis of malignant phyllodes tumor is very rare. We herein report a rare case that developed cardiac metastasis from malignant phyllodes tumor. A 38-year-old woman underwent lumpectomy, and the final pathological findings showed the 5-cm malignant phyllodes tumor partially containing 1 cm of squamous cell carcinoma. Four months after the first surgery, a local recurrence of malignant phyllodes tumor and distant metastases to the bone, lung, pulmonary main trunk, and right ventricle were detected. Mass reduction surgery of cardiac metastasis of the malignant phyllodes tumor was performed to avoid sudden death. In immunohistochemical findings, the tumor was suspected to be originated in myoepithelial cells because of the expression of smooth muscle lineage including α-smooth muscle actin and Calponin1 and highly malignant characteristics showing MIB-1 and p53 highly positive with angiogenesis. Further studies are needed to clarify the effective treatment to these tumors.

High mobility group a proteins as tumor markers

Almost 30 years ago, overexpression of HMGA proteins was associated with malignant phenotype of rat thyroid cells transformed with murine retroviruses. Thereafter, several studies have analyzed HMGA expression in a wide range of human neoplasias. Here, we summarize all these results that, in the large majority of the cases, confirm the association of HMGA overexpression with high malignant phenotype as outlined by chemoresistance, spreading of metastases, and a global poor survival. Even though HMGA proteins’ overexpression indicates a poor prognosis in almost all malignancies, their detection may be particularly useful in determining the prognosis of breast, lung, and colon carcinomas, suggesting for the treatment a more aggressive therapy. In particular, the expression of HMGA2 in lung carcinomas is frequently associated with the presence of metastases. Moreover, recent data revealed that often the cause for the high HMGA proteins levels detected in human malignancies is a deregulated expression of non-coding RNA. Therefore, the HMGA proteins represent tumor markers whose detection can be a valid tool for the diagnosis and prognosis of neoplastic diseases.

MicroRNAs are differentially deregulated in mammary malignant phyllodes tumour

AIMS

MicroRNAs (miRs) have been shown to play important roles in tumour progression. Their expression pattern can be useful for cancer classification. However, little is known about miRs in mammary phyllodes tumours (PT).

METHODS AND RESULTS

In this study, polymerase chain reaction (PCR)-based miR profiling was performed in a small PT cohort to identify deregulated miRs in malignant PT. The purported roles and targets of these miRs were further validated. Unsupervised clustering of miR expression profiling segregated PT into different grades, implicating the miR profile in PT classification. Among the deregulated miRs, miR-21, miR-335 and miR-155 were validated to be higher in malignant than in lower-grade PT in the independent cohort by quantitative PCR (qPCR) (P ≤ 0.032). Their expression correlated with some of the malignant histological features, including high stromal cellularity, nuclear pleomorphism and mitosis. Subsequent analysis of their downstream proteins, namely PTEN for miR-21/miR-155 and Rb for miR-335, also showed an independent significant negative association between miR and protein expression.

CONCLUSIONS

Differential expression of miRs in PT could be useful in diagnosis and grading of PT. Their deregulated expression, together with the altered downstream targets, implicated their active involvement in PT malignant transformation.

Gene expression-based classifications of fibroadenomas and phyllodes tumours of the breast

Fibroepithelial tumors (FTs) of the breast are a heterogeneous group of lesions ranging from fibroadenomas (FAD) to phyllodes tumors (PT) (benign, borderline, malignant). Further understanding of their molecular features and classification might be of clinical value. In this study, we analysed the expression of 105 breast cancer‐related genes, including the 50 genes of the PAM50 intrinsic subtype predictor and 12 genes of the Claudin‐low subtype predictor, in a panel of 75 FTs (34 FADs, 5 juvenile FADs, 20 benign PTs, 5 borderline PTs and 11 malignant PTs) with clinical follow‐up. In addition, we compared the expression profiles of FTs with those of 14 normal breast tissues and 49 primary invasive ductal carcinomas (IDCs). Our results revealed that the levels of expression of all breast cancer‐related genes can discriminate the various groups of FTs, together with normal breast tissues and IDCs (False Discovery Rate < 5%). Among FTs, the levels expression of proliferation‐related genes (e.g. CCNB1 and MKI67) and mesenchymal/epithelial‐related (e.g. CLDN3 and EPCAM) genes were found to be most discriminative. As expected, FADs showed the highest and lowest expression of epithelial‐ and proliferation‐related genes, respectively, whereas malignant PTs showed the opposite expression pattern. Interestingly, the overall profile of benign PTs was found more similar to FADs and normal breast tissues than the rest of tumours, including juvenile FADs. Within the dataset of IDCs and normal breast tissues, the vast majority of FADs, juvenile FADs, benign PTs and borderline PTs were identified as Normal‐like by intrinsic breast cancer subtyping, whereas 7 (63.6%) and 3 (27.3%) malignant PTs were identified as Claudin‐low and Basal‐like, respectively. Finally, we observed that the previously described PAM50 risk of relapse prognostic score better predicted outcome in FTs than the morphological classification, even within PTs‐only. Our results suggest that classification of FTs using gene expression‐based data is feasible and might provide clinically useful biological and prognostic information.

The levels expression of proliferation‐ and mesenchymal/epithelial‐related genes were found to be the most discriminative.

The overall profile of benign phyllodes was very similar to fibroadenomas.

The vast majority of fibroepithelial tumors (FTs) were identified as Normal‐like by the PAM50 and Claudin‐low predictors.

The PAM50 risk of relapse prognostic score better predicted outcome in FTs than the morphological classification.

Classification of FTs using gene expression‐based data provides clinically useful information.

Gene expression profiling of blood in brain arteriovenous malformation patients

Brain arteriovenous malformations (BAVMs) are an important cause of intracranial hemorrhage (ICH) in young adults. Gene expression profiling of blood has led to the identification of stroke biomarkers, and may help identify BAVM biomarkers and illuminate BAVM pathogenesis. It is unknown whether blood gene expression profiles differ between 1) BAVM patients and healthy controls, or 2) unruptured and ruptured BAVM patients at presentation. We characterized blood transcriptional profiles in 60 subjects (20 unruptured BAVM, 20 ruptured BAVM, and 20 healthy controls) using Affymetrix whole genome expression arrays. Expression differences between groups were tested by ANOVA, adjusting for potential confounders. Genes with absolute fold change ≥ 1.2 (false discovery rate corrected p ≤ 0.1) were selected as differentially expressed and evaluated for over-representation in KEGG biological pathways (p ≤ 0.05). Twenty-nine genes were differentially expressed between unruptured BAVM patients and controls, including 13 which may be predictive of BAVM. Patients with ruptured BAVM compared to unruptured BAVM differed in expression of 1490 genes, with over-representation of genes in 8 pathways including MAPK, VEGF, Wnt signaling and several inflammatory pathways. These results suggest clues to the pathogenesis of BAVM and/or BAVM rupture and point to potential biomarkers or new treatment targets.

Phyllodes tumor of the breast: an update

Phyllodes tumor is an uncommon biphasic breast tumor, with the ability to recur and metastasize, and it behaves biologically like a stromal neoplasm. Traditionally, phyllodes tumors are graded by the use of a set of histologic data into benign, borderline, and malignant. In most series, all phyllodes tumors may recur, but only the borderline and malignant phyllodes tumors metastasize. On the basis of histologic features, prediction of behavior is difficult. The expression of many biological markers, including p53, hormone receptors, proliferation markers, angiogenesis group of markers, c-kit, CD10 and epidermal growth factor receptor have been explored, and many have been shown to be variably expressed, depending on the grade of the tumor. These markers are, however, of limited value in predicting the behavior of the tumor. Recently investigators have reported a plethora of genetic changes in phyllodes tumors, the most consistent of which seems to be 1q gain by comparative genomic hybridization. Some candidate genes have been mapped to various sites, and preliminary data suggest that some of these changes may be related to recurrence. It is foreseeable that more exciting data will be generated to help us to understand the etiology and pathogenesis of phyllodes tumor.