There is more than one kind of myofibroblast: analysis of CD34 expression in benign, in situ, and invasive breast lesions

Reassessing Breast Cancer-Associated Fibroblasts (CAFs) Interactions with Other Stromal Components and Clinico-Pathologic Parameters by Using Immunohistochemistry and Digital Image Analysis (DIA)

BACKGROUND

Breast cancer (BC) stroma has CD34- and αSMA-positive cancer-associated fibroblasts (CAFs) differently distributed. During malignant transformation, CD34-positive fibroblasts decrease while αSMA-positive CAFs increase. The prevalence of αSMA-positive CAFs in BC stroma makes microscopic examination difficult without digital image analysis processing (DIA). DIA was used to compare CD34- and αSMA-positive CAFs among breast cancer molecular subgroups. DIA-derived data were linked to age, survival, tumor stroma vessels, tertiary lymphoid structures (TLS), invasion, and recurrence.

METHODS

Double immunostaining for CD34 and αSMA showed different CAF distribution patterns in normal and BC tissues. Single CD34 immunohistochemistry on supplemental slides quantified tumor stroma CD34_CAFs. Digital image analysis (DIA) data on CAF density, intensity, stromal score, and H-score were correlated with clinico-pathologic factors.

RESULTS

CD34/αSMA CAF proportion was significantly related to age in Luminal A (LA), Luminal B (LB), and HER2 subtypes. CD34_CAF influence on survival, invasion, and recurrence of LA, LB-HER2, and TNBC subtypes was found to be significant. The CD34/αSMA-expressing CAFs exhibited a heterogeneous impact on stromal vasculature and TLS.

CONCLUSION

BC stromal CD34_CAFs/αSMA_CAFs have an impact on survival, invasion, and recurrence differently between BC molecular subtypes. The tumor stroma DIA assessment may have predictive potential to prognosis and long-term follow-up of patients with breast cancer.

Crosstalk between colorectal cancer cells and cancer-associated fibroblasts in the tumor microenvironment mediated by exosomal noncoding RNAs

Colorectal cancer (CRC) is a common malignant tumor of the digestive system, and its morbidity rates are increasing worldwide. Cancer-associated fibroblasts (CAFs), as part of the tumor microenvironment (TME), are not only closely linked to normal fibroblasts, but also can secrete a variety of substances (including exosomes) to participate in the regulation of the TME. Exosomes can play a key role in intercellular communication by delivering intracellular signaling substances (e.g., proteins, nucleic acids, non-coding RNAs), and an increasing number of studies have shown that non-coding RNAs of exosomal origin from CAFs are not only closely associated with the formation of the CRC microenvironment, but also increase the ability of CRC to grow in metastasis, mediate tumor immunosuppression, and are involved in the mechanism of drug resistance in CRC patients receiving. It is also involved in the mechanism of drug resistance after radiotherapy in CRC patients. In this paper, we review the current status and progress of research on CAFs-derived exosomal non-coding RNAs in CRC.

Transcriptome analysis reveals differences in cell cycle, growth and migration related genes that distinguish fibroblasts derived from pre-invasive and invasive breast cancer

Background/Introduction

As the most common form of pre-invasive breast cancer, ductal carcinoma in situ (DCIS) affects over 50,000 women in the US annually. Despite standardized treatment involving lumpectomy and radiation therapy, up to 25% of patients with DCIS experience disease recurrence often with invasive ductal carcinoma (IDC), indicating that a subset of patients may be under-treated. As most DCIS cases will not progress to invasion, many patients may experience over-treatment. By understanding the underlying processes associated with DCIS to IDC progression, we can identify new biomarkers to determine which DCIS cases may become invasive and improve treatment for patients. Accumulation of fibroblasts in IDC is associated with disease progression and reduced survival. While fibroblasts have been detected in DCIS, little is understood about their role in DCIS progression.

Goals

We sought to determine 1) whether DCIS fibroblasts were similar or distinct from normal and IDC fibroblasts at the transcriptome level, and 2) the contributions of DCIS fibroblasts to breast cancer progression.

Methods

Fibroblasts underwent transcriptome profiling and pathway analysis. Significant DCIS fibroblast-associated genes were further analyzed in existing breast cancer mRNA databases and through tissue array immunostaining. Using the sub-renal capsule graft model, fibroblasts from normal breast, DCIS and IDC tissues were co-transplanted with DCIS.com breast cancer cells.

Results

Through transcriptome profiling, we found that DCIS fibroblasts were characterized by unique alterations in cell cycle and motility related genes such as PKMYT1, TGF-α, SFRP1 and SFRP2, which predicted increased cell growth and invasion by Ingenuity Pathway Analysis. Immunostaining analysis revealed corresponding increases in expression of stromal derived PKMYT1, TGF-α and corresponding decreases in expression of SFRP1 and SFRP2 in DCIS and IDC tissues. Grafting studies in mice revealed that DCIS fibroblasts enhanced breast cancer growth and invasion associated with arginase-1+ cell recruitment.

Conclusion

DCIS fibroblasts are phenotypically distinct from normal breast and IDC fibroblasts, and play an important role in breast cancer growth, invasion, and recruitment of myeloid cells. These studies provide novel insight into the role of DCIS fibroblasts in breast cancer progression and identify some key biomarkers associated with DCIS progression to IDC, with important clinical implications.

Epithelioid myofibroblastoma of the breast: A case report and review of the literature

INTRODUCTION

Mammary myofibroblastoma (MFB) is a rare tumour. Its clinical and pathologic characteristics have been only sporadically described. A case of epithelioid variant of MFB is reported with the diagnostic tips, the differential diagnoses, and a discussion on the possible pathogenesis.

PRESENTATION OF CASE

A 74 year-old woman presented with a painless nodule in the left breast. Core needle biopsy (CNB) revealed a tumour primarily composed of epithelioid cells. Despite epithelioid appearance of the tumour cells, ductal/lobular components were absent within the tumour. As cell lineage of the epithelioid cells could not be determined with CNB, lumpectomy was performed to obtain definitive diagnosis and, at the same time, to remove the lesion. Histologically, the tumour consisted of multiple epithelioid cell nests that were spread over fibrous stroma infiltrated with adipose tissue. Spindle cells were also present, but they were fewer than epithelioid cell clusters. Occasionally, the tumour cells showed nuclear atypia. It was difficult to determine whether this tumour was benign or malignant solely with Hematoxylin-eosin stain. However, with the aid of immunohistochemical analyses, we could make a histodiagnosis of epithelioid subtype of myofibroblastoma.

DISCUSSION

The differential diagnoses of epithelioid MFB include ductal, lobular, metaplastic carcinomas and mesenchymal tumours. Comprehensive knowledge of classic and variant MFB is necessary for the correct diagnosis.

CONCLUSION

Pathologic diagnosis of epithelioid variant of MFB requires careful evaluation of histology and the use of a panel of immunohistochemistry. Female phenotype of breast stroma may play a role in the pathogenesis of MFB.

CD34+ Stromal Cells/Telocytes as a Source of Cancer-Associated Fibroblasts (CAFs) in Invasive Lobular Carcinoma of the Breast

Several origins have been proposed for cancer-associated fibroblasts (CAFs), including resident CD34+ stromal cells/telocytes (CD34+SCs/TCs). The characteristics and arrangement of mammary CD34+SCs/TCs are well known and invasive lobular carcinoma of the breast (ILC) is one of the few malignant epithelial tumours with stromal cells that can express CD34 or αSMA, which could facilitate tracking these cells. Our objective is to assess whether tissue-resident CD34+SCs/TCs participate in the origin of CAFs in ILCs. For this purpose, using conventional and immunohistochemical procedures, we studied stromal cells in ILCs (n:42) and in normal breasts (n:6, also using electron microscopy). The results showed (a) the presence of anti-CD34+ or anti-αSMA+ stromal cells in varying proportion (from very rare in one of the markers to balanced) around nests/strands of neoplastic cells, (b) a similar arrangement and location of stromal cells in ILC to CD34+SCs/TCs in the normal breast, (c) both types of stromal cells coinciding around the same nest of neoplastic cells and (d) the coexpression of CD34 and αSMA in stromal cells in ILC. In conclusion, our findings support the hypothesis that resident CD34+SCs/TCs participate as an important source of CAFs in ILC. Further studies are required in this regard in other tumours.

Characterization of neoplastic cells outlining the cystic space of invasive micropapillary carcinoma of the canine mammary gland

BACKGROUND

Invasive micropapillary carcinoma (IMPC) is a rare malignant breast tumor and a variant form of invasive ductal carcinoma that is an aggressive neoplasm of the human breast and canine mammary gland. The importance of the tumor microenvironment in cancer development has gradually been recognized, but little is known about the cell types outlining the cystic space of canine IMPC. This study aimed to characterize the neoplastic cells outlining the cystic space of IMPC.

RESULTS

Immunohistochemistry (IHC), immunofluorescence (IF), superresolution and transmission electron microscopy (TEM) were used to assess the cell types in the cystic areas of IMPCs. Cells expressing the mesenchymal markers alpha-smooth muscle actin (αSMA), Vimentin, and S100A4 outlined the cystic space of IMPC. Furthermore, loss of epithelial cell polarity in IMPC was shown by the localization of MUC1 at the stroma-facing surface. This protein modulates lumen formation and inhibits the cell-stroma interaction. Immunohistochemical and IF staining for the myoepithelial cell marker p63 were negative in IMPC samples. Furthermore, associated with peculiar morphology, such as thin cytoplasmic extensions outlining cystic spaces, was observed under TEM. These observations suggested cells with characteristics of myoepithelial-like cells.

CONCLUSIONS

The cells outlining the cystic space of IMPC in the canine mammary gland were characterized using IHC, IF and TEM. The presence of cells expressing αSMA, Vimentin, and S100A4 in the IMPC stroma suggested a role for tumor-associated fibroblasts in the IMPC microenvironment. The reversal of cell polarity revealed by the limited basal localization of MUC1 may be an important factor contributing to the invasiveness of IMPC. For the first time, the cystic space of canine mammary gland IMPC was shown to be delimited by myoepithelial-like cells that had lost p63 expression. These findings may enhance our understanding of the cellular microenvironment of invasive tumors to improve cancer diagnosis and treatment.

Fibroblasts direct differentiation of human breast epithelial progenitors

BACKGROUND

Breast cancer arises within specific regions in the human breast referred to as the terminal duct lobular units (TDLUs). These are relatively dynamic structures characterized by sex hormone driven cyclic epithelial turnover. TDLUs consist of unique parenchymal entities embedded within a fibroblast-rich lobular stroma. Here, we established and characterized a new human breast lobular fibroblast cell line against its interlobular counterpart with a view to assessing the role of region-specific stromal cues in the control of TDLU dynamics.

METHODS

Primary lobular and interlobular fibroblasts were transduced to express human telomerase reverse transcriptase (hTERT). Differentiation of the established cell lines along lobular and interlobular pathways was determined by immunocytochemical staining and genome-wide RNA sequencing. Their functional properties were further characterized by analysis of mesenchymal stem cell (MSC) differentiation repertoire in culture and in vivo. The cells' physiological relevance for parenchymal differentiation was examined in heterotypic co-culture with fluorescence-activated cell sorting (FACS)-purified normal breast primary luminal or myoepithelial progenitors. The co-cultures were immunostained for quantitative assessment of epithelial branching morphogenesis, polarization, growth, and luminal epithelial maturation. In extension, myoepithelial progenitors were tested for luminal differentiation capacity in culture and in mouse xenografts. To unravel the significance of transforming growth factor-beta (TGF-β)-mediated crosstalk in TDLU-like morphogenesis and differentiation, fibroblasts were incubated with the TGF-β signaling inhibitor, SB431542, prior to heterotypic co-culture with luminal cells.

RESULTS

hTERT immortalized fibroblast cell lines retained critical phenotypic traits in culture and linked to primary fibroblasts. Cell culture assays and transplantation to mice showed that the origin of fibroblasts determines TDLU-like and ductal-like differentiation of epithelial progenitors. Whereas lobular fibroblasts supported a high level of branching morphogenesis by luminal cells, interlobular fibroblasts supported ductal-like myoepithelial characteristics. TDLU-like morphogenesis, at least in part, relied on intact TGF-β signaling.

CONCLUSIONS

The significance of the most prominent cell type in normal breast stroma, the fibroblast, in directing epithelial differentiation is largely unknown. Through establishment of lobular and interlobular fibroblast cell lines, we here demonstrate that epithelial progenitors are submitted to stromal cues for site-specific differentiation. Our findings lend credence to considering stromal subtleties of crucial importance in the development of normal breast and, in turn, breast cancer.

Presence/Absence and Specific Location of Resident CD34+ Stromal Cells/Telocytes Condition Stromal Cell Development in Repair and Tumors

CD34+ stromal cells/telocytes (CD34+SCs/TCs) can have a role as mesenchymal precursor cells. Our objective is to assess whether the myofibroblastic stromal cell response in repair and in desmoplastic reactions in tumors depend on the presence or absence of resident CD34+SCs/TCs in specific regions/layers of an organ and on the location of their possible subpopulations. For this purpose, using conventional and immunohistochemical procedures, we studied specimens of (a) acute cholecystitis, with early repair phenomena (n: 6), (b) surgically resected segments of colon tattooed with India ink during previous endoscopic removal of malignant polyps, with macrophage infiltration and stromal cell reaction (n: 8) and (c) infiltrative adenocarcinomas of colon, with desmoplastic reaction (n: 8). The results demonstrated (a) stromal myofibroblastic reaction during repair and tumor desmoplasia in most regions in which resident CD34+SCs/TCs are present, (b) absence of stromal myofibroblastic reaction during repair in the mucosa of both organs in which resident CD34+SCs/TCs are absent and (c) permanence of CD34+SCs/TCs as such, without myofibroblastic response, in smooth muscle fascicles, nerves, and Meissner and Auerbach plexuses, in which the CD34+SCs/TCs mainly undergo reactive phenomena. Therefore, the development of activated αSMA+ myofibroblasts in these conditions requires the presence of resident CD34+SCs/TCs and depends on their location. In conclusion, the facts support the hypotheses that CD34+SCs/TCs participate in the origin of myofibroblasts during repair and tumor stroma formation, and that there is a heterogeneous population of resident CD34+SCs/TCs with different roles.

Stromal CCL2 Signaling Promotes Mammary Tumor Fibrosis through Recruitment of Myeloid-Lineage Cells

Obesity is correlated with breast tumor desmoplasia, leading to diminished chemotherapy response and disease-free survival. Obesity causes chronic, macrophage-driven inflammation within breast tissue, initiated by chemokine ligand 2 (CCL2) signaling from adipose stromal cells. To understand how CCL2-induced inflammation alters breast tumor pathology, we transplanted oncogenically transformed human breast epithelial cells with breast stromal cells expressing CCL2 or empty vector into murine mammary glands and examined tumor formation and progression with time. As tumors developed, macrophages were rapidly recruited, followed by the emergence of cancer-associated fibroblasts (CAFs) and collagen deposition. Depletion of CD11b + myeloid lineage cells early in tumor formation reduced tumor growth, CAF numbers, and collagen deposition. CCL2 expression within developing tumors also enhanced recruitment of myeloid progenitor cells from the bone marrow into the tumor site. The myeloid progenitor cell population contained elevated numbers of fibrocytes, which exhibited platelet-derived growth factor receptor-alpha (PDGFRα)-dependent colony formation and growth in vitro. Together, these results suggest that chronic inflammation induced by CCL2 significantly enhances tumor growth and promotes the formation of a desmoplastic stroma through early recruitment of macrophages and fibrocytes into the tumor microenvironment. Fibrocytes may be a novel target in the tumor microenvironment to reduce tumor fibrosis and enhance treatment responses for obese breast cancer patients.

Fibrocytes in the Tumor Microenvironment

Tumors have long been compared to chronic wounds that do not heal, since they share many of the same molecular and cellular processes. In normal wounds, healing processes lead to restoration of cellular architecture, while in malignant tumors, these healing processes become dysregulated and contribute to growth and invasion of neoplastic cells into the surrounding tissues. Fibrocytes are fibroblast-like cells that differentiate from bone marrow-derived CD14+ circulating monocytes and aid wound healing. Although most monocytes will differentiate into macrophages after extravasating into a tissue, signals present in a wound environment can cause some monocytes to differentiate into fibrocytes. The fibrocytes secrete matrix proteins and inflammatory cytokines, activate local fibroblasts to proliferate and increase extracellular matrix production, and promote angiogenesis, and because fibrocytes are contractile, they also help wound contraction. There is now emerging evidence that fibrocytes are present in the tumor microenvironment, attracted by the chronic tissue damage and cytokines from both cancer cells and other immune cells. Fibrocytes may aid in the survival and spread of neoplastic cells, so these wound-healing cells may be a promising target for anticancer research in future studies.

A functional interaction between the CCR5 and CD34 molecules expressed in hematopoietic cells can support (or even promote) the development of cancer

Inflammation and angiogenesis are linked to the development of cancer since both can support the establishment of a tumor-prone microenvironment. The CCR5 is a major regulatory molecule involved in inflammation. The CD34 molecule is commonly described as a hematopoietic stem cell marker, and CD34⁺ cells are involved in the regulation of distinct physiological processes, including angiogenesis. CCR5 participates in the development of various types of cancer, and recently, a reduced CCR5 expression was associated with low CD34⁺ cell counts in human cord blood. A naturally occurring genetic variant of the CCR5 gene, the so-called CCR5Δ32 polymorphism, consists of a 32 base-pair deletion in the DNA, interfering in the CCR5 protein levels on the cell surface. When in homozygosis, this variant leads to a total absence of CCR5 expression on the cell surface. In heterozygous individuals, CCR5 surface levels are reduced. Based on these key findings, we hypothesize that a functional interaction can connect CCR5 and CD34 molecules (giving rise to a “CCR5-CD34 axis”). According to this, a CCR5-CD34 interaction can potentially support the development of different types of cancer. Consequently, the lack of CCR5 in association with reduced CD34⁺ cell counts could indicate a protective factor against the development of cancer. It is required to characterize in detail the functional relationship between CCR5 and CD34 proteins, as well as the real influence of both molecules on the susceptibility and development of cancer at population level. If our hypothesis is confirmed, the CCR5-CD34 axis may be a potential target in the development of anti-cancer therapies.

Activated hepatic stellate cells and portal fibroblasts contribute to cholestatic liver fibrosis in MDR2 knockout mice

BACKGROUND & AIMS

Chronic liver injury often results in the activation of hepatic myofibroblasts and the development of liver fibrosis. Hepatic myofibroblasts may originate from 3 major sources: hepatic stellate cells (HSCs), portal fibroblasts (PFs), and fibrocytes, with varying contributions depending on the etiology of liver injury. Here, we assessed the composition of hepatic myofibroblasts in multidrug resistance gene 2 knockout (Mdr2-/-) mice, a genetic model that resembles primary sclerosing cholangitis in patients.

METHODS

Mdr2-/- mice expressing a collagen-GFP reporter were analyzed at different ages. Hepatic non-parenchymal cells isolated from collagen-GFP Mdr2-/- mice were sorted based on collagen-GFP and vitamin A. An NADPH oxidase (NOX) 1/4 inhibitor was administrated to Mdr2-/- mice aged 12-16 weeks old to assess the therapeutic approach of targeting oxidative stress in cholestatic injury.

RESULTS

Thy1+ activated PFs accounted for 26%, 51%, and 54% of collagen-GFP+ myofibroblasts in Mdr2-/- mice at 4, 8, and 16 weeks of age, respectively. The remaining collagen-GFP+ myofibroblasts were composed of activated HSCs, suggesting that PFs and HSCs are both activated in Mdr2-/- mice. Bone-marrow-derived fibrocytes minimally contributed to liver fibrosis in Mdr2-/- mice. The development of cholestatic liver fibrosis in Mdr2-/- mice was associated with early recruitment of Gr1+ myeloid cells and upregulation of pro-inflammatory cytokines (4 weeks). Administration of a NOX inhibitor to 12-week-old Mdr2-/- mice suppressed the activation of myofibroblasts and attenuated the development of cholestatic fibrosis.

CONCLUSIONS

Activated PFs and activated HSCs contribute to cholestatic fibrosis in Mdr2-/- mice, and serve as targets for antifibrotic therapy.

LAY SUMMARY

Activated portal fibroblasts and hepatic stellate cells, but not fibrocytes, contributed to the production of the fibrous scar in livers of Mdr2-/- mice, and these cells can serve as targets for antifibrotic therapy in cholestatic injury. Therapeutic inhibition of the enzyme NADPH oxidase (NOX) in Mdr2-/- mice reversed cholestatic fibrosis, suggesting that targeting NOXs may be an effective strategy for the treatment of cholestatic fibrosis.

Enhancer Domains in Gastrointestinal Stromal Tumor Regulate KIT Expression and Are Targetable by BET Bromodomain Inhibition

Gastrointestinal stromal tumor (GIST) is a mesenchymal neoplasm characterized by activating mutations in the related receptor tyrosine kinases KIT and PDGFRA. GIST relies on expression of these unamplified receptor tyrosine kinase (RTK) genes through a large enhancer domain, resulting in high expression levels of the oncogene required for tumor growth. Although kinase inhibition is an effective therapy for many patients with GIST, disease progression from kinase-resistant mutations is common and no other effective classes of systemic therapy exist. In this study, we identify regulatory regions of the KIT enhancer essential for KIT gene expression and GIST cell viability. Given the dependence of GIST upon enhancer-driven expression of RTKs, we hypothesized that the enhancer domains could be therapeutically targeted by a BET bromodomain inhibitor (BBI). Treatment of GIST cells with BBIs led to cell-cycle arrest, apoptosis, and cell death, with unique sensitivity in GIST cells arising from attenuation of the KIT enhancer domain and reduced KIT gene expression. BBI treatment in KIT-dependent GIST cells produced genome-wide changes in the H3K27ac enhancer landscape and gene expression program, which was also seen with direct KIT inhibition using a tyrosine kinase inhibitor (TKI). Combination treatment with BBI and TKI led to superior cytotoxic effects in vitro and in vivo, with BBI preventing tumor growth in TKI-resistant xenografts. Resistance to select BBI in GIST was attributable to drug efflux pumps. These results define a therapeutic vulnerability and clinical strategy for targeting oncogenic kinase dependency in GIST. SIGNIFICANCE: Expression and activity of mutant KIT is essential for driving the majority of GIST neoplasms, which can be therapeutically targeted using BET bromodomain inhibitors.

Clinicopathological study of role of CD34 expressions in the stroma of premalignant and malignant lesions of uterine cervix

CD34 is a transmembrane glycoprotein that is thought to be involved in the modulation of cell adhesion and signal transduction. The connective tissue stroma of virtually all human organs contain large amounts of resident CD34+ fibrocytes, which are involved in multiple functions such as wound healing, secretion of cytokines and also participate in stromal remodeling. It has been seen in various studies that absence of CD34+ fibrocytes within the stroma is associated with invasive carcinomas. In our study, we also investigated the presence and distribution of CD34+ fibrocytes in cervical intraepithelial neoplasia, invasive cervical carcinoma and adjacent normal cervical stroma. It was seen that normal cervical stroma and the stroma adjacent to cervical intra epithelial lesions harbours a dense meshwork of CD34+ fibrocytes, whereas the stroma of invasive carcinoma was nearly devoid of this cell population. Early stromal invasion by squamous carcinoma was characterized by a focal loss of CD34+ fibrocytes. This can be used as a sensitive tool in detecting tiny foci of stromal invasion in early cancer.

An Immunohistochemical and Polarizing Microscopic Study of the Tumor Microenvironment in Varying Grades of Oral Squamous Cell Carcinoma

BACKGROUND

Invasion of epithelial cells into the connective tissue brings about massive morphological and architectural changes in the underlying stroma. Myofibroblasts reorganize the stroma to facilitate the movement of tumor cells leading to metastasis. The aim of this study was to determine the number and pattern of distribution of myofibroblasts and the qualitative and quantitative change that they cause in the collagen present in the stroma in various grades of oral squamous cell carcinoma (OSCC).

METHODS

The study was divided into two groups with group I (test group, 65 cases) consisting of 29 cases of well-differentiated squamous cell carcinoma, 25 moderately differentiated SCC, and 11 poorly differentiated SCC, and group II (control group) consisting of 11 cases of normal mucosa. Sections from each sample were stained with anti-α-smooth muscle actin (α-SMA) antibodies, hematoxylin and eosin, and Picrosirius red. Several additional sections from each grade of OSCC were stained with Masson's trichrome to observe the changes in collagen. For the statistical analysis, Fisher's exact test, Tukey's post hoc honest significant difference test, ANOVA, and the chi-square test were used, and p < .05 was considered statistically significant.

RESULTS

As the tumor stage progressed, an increase in the intensity α-SMA expression was seen, and the network pattern dominated in more dedifferentiated carcinomas. The collagen fibers became thin, loosely packed, and haphazardly aligned with progressing cancer. Additionally, the mean area fraction decreased, and the fibers attained a greenish yellow hue and a weak birefringence when observed using polarizing light microscopy.

CONCLUSIONS

Myofibroblasts bring about numerous changes in collagen. As cancer progresses, there isincrease in pathological collagen,which enhances the movement of cells within the stroma.

Interaction between oral squamous cell carcinoma cells and fibroblasts through TGF-β1 mediated by podoplanin

Podoplanin is upregulated in the invasive front of oral squamous cell carcinoma (OSCC). Carcinoma-associated fibroblasts (CAFs) may mediate podoplanin expression. However, the role of podoplanin in OSCC cell and fibroblast interaction remains elusive. In the present study, we found that positive podoplanin expression in OSCC cells correlated with smooth muscle actin (α-SMA) expression in CAFs. Using CAFs and normal mucosal fibroblasts (NFs), we established indirect and direct co-culture systems mimicking the structure of OSCC. Podoplanin-overexpressing OSCC cells promoted NF activation; in direct co-culture, but not in indirect co-culture, podoplanin-overexpressing OSCC cells increased fibroblast invasion via matrix metalloproteinase 2 (MMP-2), MMP-14, and αv/β6 integrin receptor (ITGA5/ITGB6) signaling. CAFs also induced podoplanin expression through the transforming growth factor-β1 (TGF-β1)/Smad pathway. TGF-β1 increased the podoplanin-dependent activation of epidermal growth factor receptor (EGFR), AKT, and extracellular signal-regulated kinase (ERK) signaling. Additionally, CAFs promoted OSCC cell invasion by upregulating MMP-2 and MMP-14 expression in both indirect and direct co-culture. Taken together, our findings indicate that podoplanin regulates the interaction between OSCC cells and CAFs via the mutual paracrine effects of TGF-β1.

Benign Fibromyxoid Lesion of the Breast: A Distinct Entity From Benign Spindle Cell Tumors of the Mammary Stroma?

Myxoid lesions of the breast can be diagnostically challenging entities. We report 4 cases of CD34+ fibromyxoid lesion that have been previously diagnosed as “benign myxoid lesion,” “nodular mucinosis,” or “mammary myofibroblastoma, myxoid type” on the basis of CD34-positivity. The lesions were microscopically well circumscribed and composed of a paucicellular spindle cell proliferation in a background of myxoid stroma. No epithelial component was identified. The spindle cells showed immunohistochemical reactivity for CD34 and smooth muscle actin. Based on morphologic and immunohistochemical similarities between these cases and myxoid myofibroblastoma, we compared 4 myxoid lesions with cases of typical myofibroblastoma, utilizing retinoblastoma (Rb) antibody and fluorescent in situ hybridization for 13q14 gene rearrangement (encoding the Rb gene). The myxoid lesions showed retention of Rb protein by immunohistochemistry, whereas Rb expression was lost in cases of myofibroblastoma. We identified loss of 13q14 in 3 of 4 cases of myofibroblastoma. Notably, 13q14 gene rearrangement was not observed in any of the myxoid lesions. Our data show that there is at least a subset of CD34+ fibromyxoid lesions that, despite overlapping morphologic and immunohistochemical phenotype and proposed common histogenesis with myofibroblastomas, is genetically distinct from the latter based on Rb analysis.

A Diagnostic Approach to Fibroepithelial Breast Lesions

Fibroepithelial breast lesions encompass a heterogeneous group of neoplasms that range from benign to malignant, each exhibiting differing degrees of stromal proliferation in relation to the epithelial compartment. Fibroadenomas are common benign neoplasms that may be treated conservatively. Phyllodes tumors are relatively rare lesions, and classified as benign, borderline, or malignant based on histologic evaluation of various parameters. The diagnostic interpretation of "gray-zone" fibroepithelial lesions often imposes formidable demands on a pathologist's skills. This article offers practical recommendations for the diagnostic workup of these lesions, including the appropriate utilization of ancillary investigations and the approach to core needle biopsies.

Effects of cytokines derived from cancer-associated fibroblasts on androgen synthetic enzymes in estrogen receptor-negative breast carcinoma

PURPOSE

The tumor microenvironment plays pivotal roles in promotion of many malignancies. Cancer-associated fibroblasts (CAFs) have been well-known to promote proliferation, angiogenesis, and metastasis but mechanistic understanding of tumor-stroma interactions is not yet complete. Recently, estrogen synthetic enzymes were reported to be upregulated by co-culture with stromal cells in ER positive breast carcinoma (BC) but effects of co-culture on androgen metabolism have not been extensively examined. Therefore, we evaluated roles of CAFs on androgen metabolism in ER-negative AR-positive BC through co-culture with CAFs.

METHODS

Concentrations of steroid hormone in supernatant of co-culture of MDA-MB-453 and primary CAFs were measured using GC-MS. Cytokines derived from CAFs were determined using Cytokine Array. Expressions of androgen synthetic enzymes were confirmed using RT-PCR and Western blotting. Correlations between CAFs and androgen synthetic enzymes were analyzed using triple-negative BC (TNBC) patient tissues by immunohistochemistry.

RESULTS

CAFs were demonstrated to increase expressions and activities of 17βHSD2, 17βHSD5, and 5α-Reductase1. IL-6 and HGF that were selected as potential paracrine mediators using cytokine array induced 17βHSD2, 17βHSD5, and 5α-Reductase1 expression. Underlying mechanisms of IL-6 paracrine regulation of 17βHSD2 and 17βHSD5 could be partially dependent on phosphorylated STAT3, while phosphorylated ERK could be involved in HGF-mediated 5α-Reductase1 induction. α-SMA status was also demonstrated to be significantly correlated with 17βHSD2 and 17βHSD5 status in TNBC tissues, especially AR-positive cases.

CONCLUSIONS

Results of our present study suggest that both IL-6 and HGF derived from CAFs could contribute to the intratumoral androgen metabolism in ER-negative BC patients.

Bilateral breast keloids in an elderly woman associated with bilateral breast cancers and high concentration of serum tumor growth factor-β

We report a case of bilateral annular breast keloids in a 72-year-old woman who had been suffering from bilateral breast cancers. Histopathologically, the keloids showed unique distribution of α-SMA+, CD34- myofibroblasts and α-SMA-, CD34+ fibroblasts depending on the region. High serum levels of tumor growth factor-β were detected at 6 months after the development of the breast keloids, but not at 10 months. CD163-positive cells were abundantly detected in the skin of the elevated portion of the keloids. In contrast, these cells were considerably less numerous in the skin of the central healing portion compared with the skin of the elevated expanding portion. One interesting idea based on these results is that high levels of tumor growth factor-β released from CD163-positive cells played a crucial role in the formation of breast keloids through active induction of fibroblast differentiation into myofibroblasts. The present case strongly supports the previously proposed idea that keloids can form as a paraneoplastic phenomenon in breast cancer patients with keloid constitution.

Prolactin/androgen-inducible carboxypeptidase-D increases with nitrotyrosine and Ki67 for breast cancer progression in vivo, and upregulates progression markers VEGF-C and Runx2 in vitro

PURPOSE

Carboxypeptidase-D (CPD) cleaves C-terminal arginine (Arg) to produce nitric oxide (NO). Upregulation of CPD and NO by 17β-estradiol, prolactin (PRL), and androgen increases survival of human breast cancer (BCa) cells in vitro. To demonstrate similar events in vivo, CPD, nitrotyrosine (NT, hallmark of NO action), androgen receptor (AR), prolactin receptor (PRLR), and phospho-Stat5a (for activated PRLR) levels were evaluated in benign and malignant human breast tissues, and correlated with cell proliferation (Ki67) and BCa progression (Cullin-3) biomarkers.

METHODS

Paraffin-embedded breast tissues were analyzed by immunohistochemistry (IHC). BCa progression markers in human MCF-7 and T47D BCa cell lines treated with NO donor SIN-1 or PRL, ±CPD inhibitors were analyzed by RT-qPCR and immunoblotting.

RESULTS

IHC showed progressive increases in CPD, NT, Ki67, and Cullin-3 from low levels in benign tissues to high levels in ductal carcinoma in situ, low-grade, high-grade, and triple-negative BCa. CPD and NT staining were closely associated, implicating CPD in NO production. Phospho-Stat5a increased significantly from benign to high-grade BCa and was mostly nuclear. AR and PRLR were abundant in benign breast and BCa, including triple-negative tumors. SIN-1 and PRL increased VEGF-C and Runx2, but not Cullin-3, in BCa cell lines. PRL induction of VEGF-C and Runx2 was inhibited partly by CPD inhibitors, implicating NO, produced by PRL-regulated CPD, in BCa progression.

CONCLUSIONS

The CPD-Arg-NO pathway contributes to BCa progression in vitro and in vivo. PRL/androgen activation of the pathway support combined AR and PRLR blockade as an additional therapy for BCa.

Endothelial cell markers from clinician's perspective

Endothelial cell markers are membrane-bound or cytoplasmic molecules expressed by endothelial cells, which help their easier identification and discrimination from other cell types. During vasculogenesis, endothelial cells differentiate from hemangioblasts to form new blood vessels. With the discovery of endothelial progenitor cells (EPC) and their ability to form new blood vessels, the term vasculogenesis is not only reserved for the embryonic development. Possibility of de novo blood vessel formation from EPC is now widely explored in different ischemic conditions, especially in cardiovascular medicine. Numerous clinical trials have tested enhancing tissue vascularization by delivering hematopoietic cells that expressed endothelial markers. This therapeutic approach proved to be challenging and promising, particularly for patients who have exhausted all conventional therapeutic modalities. Angiogenesis, which refers to the formation of new blood vessels from existing vasculature, is indispensable process during tumor progression and metastasis. Blockage of tumor angiogenesis by targeting and inhibiting endothelial cell has emerged as novel safe and efficacious method to control many advanced malignant diseases. Numerous clinical studies are currently testing new antiangiogenic drugs which target and inhibit endothelial cell markers, receptors or molecules which transmit receptor-mediated signals, therefore inhibiting endothelial cell proliferation, migration and vascular tube formation. Many of these drugs are now widely used in clinical settings as first- or second-line chemotherapy in advanced malignant conditions. So far, these therapeutic approaches gave modest, yet encouraging clinical improvements, prolonging survival and improving functional capacity and quality of life for many terminally ill patients. Here we present the most commonly used endothelial cell markers along with their applicability in contemporary clinical practice.

Human adipose stem cell differentiation is highly affected by cancer cells both in vitro and in vivo: implication for autologous fat grafting

Recent studies showed that mesenchymal stem cells derived from adipose tissue can promote tumour progression, raising some concerns regarding their use in regenerative medicine. In this context, we co-cultured either SAOS2 osteosarcoma or MCF7 breast cancer cells with human adipose stem cells (hASCs), in order to evaluate potential effects of cancer cells on hASCs differentiation, in vitro and in vivo. In this study we observed that both SAOS2 and MCF7 cell lines induced an increase in hASCs proliferation, compared to hASCs alone, but, surprisingly, neither changes in the expression of CD90, CD29, CD324 and vimentin, nor variations in the Twist and Slug mRNAs were detectable. Noteworthy, SAOS2 and MCF7 cells induced in hASCs an upregulation of CD34 expression and stemness genes, including OCT3/4, Nanog, Sox2 and leptin, and a decrease in angiogenic factors, including CD31, PDGFα, PDGFRα, PDGFRβ and VEGF. SMAD and pSMAD2/3 increased only in hASCs alone. After 21 days of co-culture, hASCs differentiated both in adipocytes and endothelial cells. Moreover, co-injection of MCF7 cells with hASCs led to the formation of a highly vascularized tumour. Taken together our findings suggest that mesenchymal stem cells, under tumour cell induction, do not differentiate in vitro or facilitate the angiogenesis of the tumour in vivo, thus opening interesting new scenarios in the relationship between cancer and stem cells. These findings may also lead to greater caution, when managing autologous fat grafts in cancer patients.

Extra-acral cutaneous sclerosing perineurioma with CD34 fingerprint pattern

Sclerosing perineuroma is a variant of extraneural perineurioma that, as a rule, occurs in acral sites. However, it has also been occasionally reported in non-acral regions. Recently, CD34 expression in a pattern reminiscent of the human fingerprint has been observed in a subset of perineuriomas, but this immunohistochemical finding has not been documented in non-acral sclerosing perineuriomas. We report a case of sclerosing perineurioma presenting CD34 expression in a fingerprint-like pattern on the skin of the neck (a previously unreported site for this neoplasm) of a 56-year-old man. In addition, alpha smooth-muscle actin showed a similar pattern of expression, suggesting that the cell population implicated in the remarkable immunolabeling is most probably fibroblastic/myofibroblastic. Other immunohistochemical findings included epithelial membrane antigen and claudin1-positive lesional cells, and the absence of S100, glucose transporter protein 1, MUC4 and desmin.

Stiffened Extracellular Matrix and Signaling from Stromal Fibroblasts via Osteoprotegerin Regulate Tumor Cell Invasion in a 3-D Tumor in Situ Model

Several changes have been described in the stroma surrounding a tumor, including changes in cellular composition, altered extracellular matrix composition and organization, and increases in stiffness. Tumor cells are influenced by the composition, organization, and mechanical properties of the microenvironment, and by signals from stromal cells. Here we sought to test whether signaling from stromal fibroblasts and/or the small change in stiffness observed in vivo surrounding epithelial tumors regulates tumor cell invasion from a model of a tumor in situ. We generated a novel tumor in situ model system in which a tumor spheroid is encased within a collagen-IV containing membrane and further encased within a collagen-I matrix of in vivo stiffness with or without fibroblasts. Effects of the matrix, fibroblasts or fibroblast signals were determined by observing the invasion of tumor cells into the matrix. Effects of reciprocal tumor cell signaling upon fibroblasts were determined by observing markers of fibroblast activation. We found that a stiffened matrix led to increased dissemination of MDA-MB-231 cells from tumor spheroids when no fibroblasts were present and that MCF10A cells maintained a more normal organization with a stiffened matrix. The presence of fibroblasts, or fibroblast conditioned media, attenuated the effect upon MDA-MB-231 cells. We also observed an attenuation of fibroblast activation associated gene expression in the presence of MDA-MB-231 cells, with a paradoxical increase in activation associated contractile activity. Furthermore, we identified osteoprotegerin as a soluble factor released by fibroblasts in the stiffened environment that is key to the inhibition of cell invasion.

Telocytes heterogeneity: From cellular morphology to functional evidence

Telocytes (TCs), located ubiquitously in the internal organs of vertebrates, are a heterogeneous, recently described, cell population of the stromal space. Characterized by lengthy cytoplasmic extensions that can reach tens of microns and are called telopodes (Tps), TCs are difficult to see using conventional microscopes. It was the electron microscopy which led to their first identification and Popescu's team the first responsible for the reconstructions indicating TCs 'organization' in a three-dimensional (3D) network that is believed to be accountable for the complex roles of TCs. Gradually, it became increasingly evident that TCs are difficult to characterize in terms of immunophenotype and that their phenotype is different depending on the location and needs of the tissue at one time. This review discusses the growing body of evidence accumulated since TCs were discovered and highlights how the complex interplay between TCs and stem cells might be of importance for tissue engineering and regenerative medicine.

Chronic Inflammation and Breast Pathology: A Theoretical Model

Breast cell pathology results from biochemical and molecular changes that culminate in the cell’s loss of functional responsiveness. The epithelial cell compartment in the breast ductal system is the site of approximately 98% of malignant proliferations, and it is from within these cells that the first biochemical signal of change may be expressed as an inflammatory response. Inflammation may be represented by biomarkers of early pathologic changes in breast cells and be associated with risk for the development of breast cancer. A theoretical model of the inflammatory process is proposed showing predictive linkages among stimuli in the breast microenvironment and the development of breast pathology, in particular, breast cancer. This model fuels intervention concepts that may prevent malignant breast health outcomes.

Invasive Micropapillary Carcinoma of the Breast: An Immunohistochemical Study of Neoplastic and Stromal Cells

A 59-year-old woman complained of a palpable mass in the right breast, and a needle biopsy disclosed small clusters of neoplastic cells in the fibrous stroma. The small clusters did not contain fibrovascular cores but exhibited micropapillary configuration. Epithelial membrane antigen (EMA) immunohistochemistry confirmed the reverse polarity of the neoplastic cells. Additionally, the plasma membrane of many neoplastic cells stained with E-cadherin and f-catenin. Myofibroblasts, which were positive for alpha smooth muscle actin (ASMA) and negative for cytokeratin 14, were abundant in the neoplastic stroma, but no CD34-positive stromal cells were observed in the neoplastic stroma. For comparison, 3 additional cases of invasive micropapillary carcinoma (IMC) and 4 cases of invasive ductal carcinoma (IDC) were studied. Similar results for stromal cells were obtained in all cases. Our results from this preliminary investigation suggest that CD34-positive stromal cells may disappear from the stroma of IMC as well as IDC.

Skeletal stem cell isolation: A review on the state-of-the-art microfluidic label-free sorting techniques

Skeletal stem cells (SSC) are a sub-population of bone marrow stromal cells that reside in postnatal bone marrow with osteogenic, chondrogenic and adipogenic differentiation potential. SSCs reside only in the bone marrow and have organisational and regulatory functions in the bone marrow microenvironment and give rise to the haematopoiesis-supportive stroma. Their differentiation capacity is restricted to skeletal lineages and therefore the term SSC should be clearly distinguished from mesenchymal stem cells which are reported to exist in extra-skeletal tissues and, critically, do not contribute to skeletal development. SSCs are responsible for the unique regeneration capacity of bone and offer unlimited potential for application in bone regenerative therapies. A current unmet challenge is the isolation of homogeneous populations of SSCs, in vitro, with homogeneous regeneration and differentiation capacities. Challenges that limit SSC isolation include a) the scarcity of SSCs in bone marrow aspirates, estimated at between 1 in 10-100,000 mononuclear cells; b) the absence of specific markers and thus the phenotypic ambiguity of the SSC and c) the complexity of bone marrow tissue. Microfluidics provides innovative approaches for cell separation based on bio-physical features of single cells. Here we review the physical principles underlying label-free microfluidic sorting techniques and review their capacity for stem cell selection/sorting from complex (heterogeneous) samples.

Behaviour of telocytes during physiopathological activation

We consider CD34+ stromal cells/telocytes (CD34+ SC/TCs) in normal and pathological conditions. These cells are involved in organisation and control of the extracellular matrix, structural support, creation of microenvironments, intercellular communication, neurotransmission, immunomodulation and immunosurveillance, inhibition of apoptosis, and control, regulation and source of other cell types. CD34+ SC/TCs are widely reported in the origin of interstitial cells of Cajal and in regeneration in the heart, skeletal muscle, skin, respiratory tree, liver, urinary system and the eye. In addition, we contribute CD34+ SC/TC hyperplasia associated with several processes, including neurogenous hyperplasia (neuroma of the appendix), hyperplasia of Leydig cells in undescended testes (Cryptorchidism), peripheral areas of inflammatory/repair processes (pericicatricial tissue and transitional zones between diseased segments in Crohn's disease and normal bowel), benign tumours (neurofibromas, Antoni-B zones of neurilemmomas, granular cell tumours, and melanocytic nevi) and in some lesions with myxoid, oedematous and degenerative changes (Reinke's oedema, myxomatous mitral valve degeneration, thyroid-associated ophthalmopathy and basophilic degenerative changes of the collagen in the dermis). We pay particular attention to the role of CD34+ SC/TCs during repair through granulation tissue, including morphologic changes, loss of CD34 expression and gain of αSMA expression with myofibroblast transformation, and interactions with pericytes, endothelial and inflammatory cells. Finally, we consider CD34 or αSMA expression in stromal cells of malignant epithelial tumours, and the role of CD34+ SC/TCs in the origin of carcinoma-associated fibroblasts (CAFs) and myofibroblasts. In conclusion, CD34+ SC/TCs play an important role in the maintenance and modulation of tissue homeostasis and in morphogenesis/renewal/repair.

CD105 expression on CD34-negative spindle-shaped stromal cells of primary tumor is an unfavorable prognostic marker in early breast cancer patients

Several studies have confirmed that the breast tumor microenvironment drives cancer progression and metastatic development. The aim of our research was to investigate the prognostic significance of the breast tumor microenvironment in untreated early breast cancer patients. Therefore, we analyzed the association of the expression of α-SMA, FSP, CD105 and CD146 in CD34-negative spindle-shaped stromal cells, not associated with the vasculature, in primary breast tumors with classical prognostic marker levels, metastatic recurrence, local relapse, disease-free survival, metastasis-free survival and the overall survival of patients. In the same way, we evaluated the association of the amount of intra-tumor stroma, fibroblasts, collagen deposition, lymphocytic infiltration and myxoid changes in these samples with the clinical-pathological data previously described. This study is the first to demonstrate the high CD105 expression in this stromal cell type as a possible independent marker of unfavorable prognosis in early breast cancer patients. Our study suggests that this new finding can be useful prognostic marker in the clinical-pathological routine.

Live fibroblast harvest reveals surface marker shift in vitro

Current methods for the isolation of fibroblasts require extended ex vivo manipulation in cell culture. As a consequence, prior studies investigating fibroblast biology may fail to adequately represent cellular phenotypes in vivo. To overcome this problem, we describe a detailed protocol for the isolation of fibroblasts from the dorsal dermis of adult mice that bypasses the need for cell culture, thereby preserving the physiological, transcriptional, and proteomic profiles of each cell. Using the described protocol we characterized the transcriptional programs and the surface expression of 176 CD markers in cultured versus uncultured fibroblasts. The differential expression patterns we observed highlight the importance of a live harvest for investigations of fibroblast biology.

Diagnostic and prognostic impact of peritumoral stromal remodeling in patients with surgically treated invasive penile squamous cell cancer

Stromal remodeling (SR), characterized by focal loss of CD34(+) fibrocytes paralleled by a gain of α-smooth muscle actin (α-SMA)-positive myofibroblasts, has been reported in several cancer types. However, the role of SR in invasive penile squamous cell cancer (PSC) has not been investigated so far. We compared 90 surgically treated PSCs (study group) and 55 control specimens (33 foreskins and 22 differentiated penile intraepithelial neoplasias) for the presence of stromal CD34(+) fibrocytes and α-SMA-positive myofibroblasts scored by independent raters. Multivariate proportional hazards regression analysis was used to assess the impact of staining profiles on cancer-specific mortality of the 90 PSCs (median follow-up, 32 months; interquartile range, 6-64). The incidence of SR differed significantly between study and control group specimens (51.1% versus 9.1%; P < .001). Five years postsurgically, 24% and 46% of the study patients without and with SR had succumbed to their PSC (P = .010). After adjusting for the age at the time of surgery, type of surgery, tumor size, Broders' grade, pT stage, and nodal status, study patients with SR showed 3.76-fold increased cancer-specific mortality (95% confidence interval, 1.3-10.5; P = .012). Our findings suggest that SR might have prognostic as well as some limited differential diagnostic value in terms of delineating invasive PSC from preinvasive lesions. However, our preliminary data clearly need to be validated by larger advanced studies in the future.

Stromal myofibroblasts in nonmetastatic and metastatic oral squamous cell carcinoma: An immunohistochemical study

BACKGROUND AND AIMS

Myofibroblasts are one of the important components of the tumor microenvironment which could possibly play an important role in tumor progression. The purpose of this study was to compare the presence of α-smooth muscle actin (α-SMA) and CD34 positive fibroblasts in nonmetastatic and metastatic oral squamous cell carcinoma and to evaluate their role in tumor metastasis.

MATERIALS AND METHODS

Ten cases each of histologically proven metastatic and nonmetastatic oral squamous cell carcinoma formed the study group. The tissue sections were stained immunohistochemically for α-SMA and CD34. The stromal spindle cells positive for these markers in the study groups were counted and compared.

RESULTS

α-SMA positive cases were more in the metastatic group and CD34 positive cases were found to be more in the nonmetastatic tumors.

CONCLUSIONS

Though difference in the staining pattern was statistically nonsignificant, the inverse relationship between α-SMA and CD34 positive cells is indicative of dynamic nature and the influence of tumor stroma in tumor progression and metastasis.

Digital microscopy assessment of angiogenesis in different breast cancer compartments

Background/Aim. Tumour angiogenesis defined by microvessel density (MVD) is generally accepted as a prognostic factor in breast cancer. However, due to variability of measurement systems and cutoffs, it is questionable to date whether it contributes to predictive outline. Our study aims to grade vascular heterogeneity by comparing clear-cut compartments: tumour associated stroma (TAS), tumour parenchyma, and tumour invasive front. Material and Methods. Computerized vessel area measurement was performed using a tissue cytometry system (TissueFAXS) on slides originated from 50 patients with breast cancer. Vessels were marked using immunohistochemistry with CD34. Regions of interest were manually defined for each tumour compartment. Results. Tumour invasive front vascular endothelia area was 2.15 times higher than that in tumour parenchyma and 4.61 times higher than that in TAS (P < 0.002). Worth to mention that the lymph node negative subgroup of patients show a slight but constant increase of vessel index in all examined compartments of breast tumour. Conclusion. Whole slide digital examination and region of interest (ROI) analysis are a valuable tool in scoring angiogenesis markers and disclosing their prognostic capacity. Our study reveals compartments' variability of vessel density inside the tumour and highlights the propensity of invasive front to associate an active process of angiogenesis with potential implications in adjuvant therapy.

Variable stromal periductular expression of CD34 and smooth muscle actin (SMA) in intraductal carcinoma of the breast

In breast carcinoma, the stromal loss of CD34 expression and acquisition of SMA myofibroblastic features may constitute a prerequisite for tumor invasiveness. However, this hypothesis remains controversial, with some authors describing the loss of CD34 fibrocytes in the absence of SMA myofibroblastic-like cells in the stroma of invasive carcinoma. Others have also described the disappearance of CD34 fibrocytes from in situ carcinoma. To clarify this issue, we compared the distribution of CD34 fibrocytes and SMA reactive myofibroblasts between stromal areas of tumor-free mammary tissue, ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). In addition to 28 IDC, 300 normal duct–lobular units and 600 ducts with DCIS (158 low-grade, 266 intermediate, and 176 high-grade) were scored. The relationships between staining patterns and different histological features (grade of DCIS and presence or absence of necrosis) were compared. Loss of CD34 expression and acquisition of SMA expression were more frequent in high-grade in situ lesions than in intermediate and low-grade lesions (p<0.001). When necrosis was found in association with grade 2 or 3 DCIS, the decrease in CD34 expression was higher than in lesions without necrosis and that independently of the grade of DCIS (p<0.05). Necrosis did not appear to play a significant role in the expression of SMA (p = 0.35). In all cases, the stroma of invasive carcinomas showed a complete loss of CD34 fibrocytes. Future research on both CD34 fibrocytes and mechanisms stromal changes are essential in the future and may potentially lead to new treatment approaches.

Elevated circulating fibrocyte levels in patients with hypertensive heart disease

OBJECTIVE

Autopsy and biopsy studies have shown that there is significantly more fibrosis in hearts of patients with hypertensive heart disease compared to normal hearts. Fibrocytes, a population of circulating bone marrow-derived cells, have been shown to home to tissues and promote scar formation in several diseases, but their role in human hypertensive heart disease has not been investigated to date. Our objective was to determine whether fibrocyte levels are elevated in individuals with hypertensive heart disease.

METHODS

We measured peripheral blood fibrocyte levels and their activated phenotypes in 12 individuals with hypertensive heart disease as determined by increased left ventricular mass on noninvasive imaging and compared them to fibrocyte levels from 19 healthy normal controls and correlated them to cardiac MRI findings.

RESULTS

Compared to normal controls, individuals with hypertensive heart disease had significantly higher circulating levels of total fibrocytes [median (interquartile range); 149000 (62200-220000) vs. 564500 (321000-1.2900e(+006)), P < 0.0001, respectively] as well as activated fibrocytes [15700 (6380-19800) vs. 478500 (116500-1.2360e(+006)) P < 0.0001]. Moreover, the fibrocyte subsets expressing the chemokine markers CXCR4 (P < 0.0001), CCR2 (P < 0.0001), CCR7 (P < 0.0001) and coexpression of both CXCR4 and CCR2 (P < 0.0001) were significantly elevated in patients with hypertensive heart disease compared to controls. Lastly, in patients with hypertensive heart disease there was a strong correlation between left ventricular mass index and total fibrocytes (r = 0.65, P = 0.037) and activated fibrocytes (r = 0.70, P = 0.016).

CONCLUSION

Our data suggest that bone marrow-derived circulating fibrocytes are associated with the presence and extent of left ventricular hypertrophy in patients with hypertensive heart disease.

Transcription factor networks in invasion-promoting breast carcinoma-associated fibroblasts

Carcinoma-associated fibroblasts (CAFs) contribute to both tumor growth and cancer progression. In this report, we applied an emerging transcription factor (TF) activity array to fibroblasts to capture the activity of the intracellular signaling network and to define a signature that distinguishes mammary CAFs from normal mammary fibroblasts. Normal fibroblasts that restrained cancer cell invasion developed into an invasion-promoting CAF phenotype through exposure to conditioned medium from MDA-MB-231 breast cancer cells. A myofibroblast-like CAF cell line expressing high levels of smooth muscle actin was compared to normal mammary fibroblasts before and after induction. Comparison of TF activity profiles for all three fibroblast types identified a TF activity signature common to CAFs which included activation of reporters for TFs ELK1, GATA1, retinoic acid receptor (RAR), serum response factor (SRF), and vitamin D receptor (VDR). Additionally, CAFs resembling myofibroblasts, relative to normal fibroblasts, had elevated activation corresponding to NF-kappaB, RUNX2, and YY1, and distinct activity patterns for several differentiation-related TF reporters. Induction of CAFs by exposure of normal fibroblasts to conditioned medium from MDA-MB-231 cells resulted in increased activation of reporters for HIF1, several STAT TFs, and proliferation-related TFs such as AP1. Myofibroblast-like CAFs and induced normal mammary fibroblasts promoted invasion of breast cancer cells by distinct mechanisms, consistent with their distinct patterns of TF activation. The TF activity profiles of CAF subtypes provide an overview of intracellular signaling associated with the induction of a pro-invasive stroma, and provide a mechanistic link between the microenvironmental stimuli and phenotypic response.

[The advancement of cancer-associated fibroblasts in lung cancer]

癌相关成纤维细胞（cancer-associated fibroblasts, CAFs）是肿瘤组织中被癌细胞激活的成纤维细胞，具有成肌纤维细胞的特性。CAFs表型恶性转换与肿瘤演进密切相关，同时CAFs是肿瘤微环境的主要组织成分。本文主要从以下方面结合肺癌进行综述：①CAFs的来源及其形态学特征，CAFs异质性及其表型时、空转换的临床意义；②CAFs的研究现状及临床应用中的问题；③CAFs与肺癌侵袭与转移的关系；④CAFs对肺癌预后及其治疗的影响。

Comparison of myofibroblasts expression in oral squamous cell carcinoma, verrucous carcinoma, high risk epithelial dysplasia, low risk epithelial dysplasia and normal oral mucosa

The aim was to evaluate and compare the presence of myofibroblasts in oral squamous cell carcinoma (OSCC), verrucous carcinoma (VC), high-risk epithelial dysplasia (HRED), low-risk epithelial dysplasia (LRED), and normal oral mucosa (NOM). The study consisted of 37 OSCC, 15 VC, 15 HRED, 15 LRED and 15 NOM. α-smooth muscle actin (α-SMA) antibody was used to identify myofibroblasts. The α-SMA expression was not observed in NOM and LRED. The α-SMA was expressed in 97.29% of OSCC, 86.66% of VC, 46.66 % of HRED. The α-SMA expression was significantly higher in OSCC than VC (p = 0.023) and HRED (p < 0.000). The α-SMA expression was significantly higher in VC than HRED (p = 0.043). Myofibroblastic expression, as highlighted by α-SMA, is undetectable in NOM and LRED but increases as the disease progresses from potentially malignant disorders, as HRED to VC to invasive OSCC. Thus, proliferation of myofibroblasts may be used as a stromal marker of oral premalignancy and malignancy.

Expression and role of fibroblast activation protein-alpha in microinvasive breast carcinoma

BACKGROUND

Diagnosis of ductal carcinoma in situ (DCIS) in breast cancer cases is challenging for pathologist due to a variety of in situ patterns and artefacts, which could be misinterpreted as stromal invasion. Microinvasion is detected by the presence of cytologically malignant cells outside the confines of the basement membrane and myoepithelium. When malignant cells invade the stroma, there is tissue remodeling induced by perturbed stromal-epithelial interactions. Carcinoma-associated fibroblasts (CAFs) are main cells in the microenvironment of the remodeled tumor-host interface. They are characterized by the expression of the specific fibroblast activation protein-alpha (FAP-α), and differ from that of normal fibroblasts exhibiting an immunophenotype of CD34. We hypothesized that staining for FAP-α may be helpful in determining whether DCIS has microinvasion.

METHODS

349 excised breast specimens were immunostained for smooth muscle actin SMA, CD34, FAP-α, and Calponin. Study material was divided into 5 groups: group 1: normal mammary tissues of healthy women after plastic surgery; group 2: usual ductal hyperplasia (UDH); group 3: DCIS without microinvasion on H & E stain; group 4: DCIS with microinvasion on H & E stain (DCIS-MI), and group 5: invasive ductal carcinoma (IDC). A comparative evaluation of the four immunostains was conducted.

RESULTS

Our results demonstrated that using FAP-α and Calponin adjunctively improved the sensitivity of pathological diagnosis of DCIS-MI by 11.29%, whereas the adjunctive use of FAP-α and Calponin improved the sensitivity of pathological diagnosis of DCIS by 13.6%.

CONCLUSIONS

This study provides the first evidence that immunostaining with FAP-α and Calponin can serve as a novel marker for pathologically diagnosing whether DCIS has microinvasion.

Tissue remodelling in breast cancer: human mast cell tryptase as an initiator of myofibroblast differentiation

AIMS

Cancerogenesis is characterized by increase of differentiated myofibroblasts. Mast cells (MCs) exert powerful effects on fibroblasts through a variety of mediators. We investigated α-smooth-muscle actin (α-SMA(+) ) and CD34(+) fibroblasts, density of toluidine blue-stained (MCs-TB) and tryptase-immunolabelled MCs (MCs-Try) in 30 primary breast tumours.

METHODS AND RESULTS

Tumour (T), peri-tumoral (PT) and non-tumoral (NT) tissue was studied by immunohistochemistry and electron microscopy. MCs-TB and MCs-Try increased gradually from NT to PT and T and the comparison between the three compartments varied significantly. Degranulated MCs were present more significantly in NT and adjacent PT than T. Transition between NT, PT and T was marked by increasing α-SMA(+) fibroblasts and slow disappearance of CD34(+) stromal cells. In NT, CD34(+) fibroblasts correlated with low density both of MCs-TB and intact MCs-Try (P=0.0346 and P=0.0409, respectively). In T, the few preserved CD34(+) fibroblasts were associated with low-density degranulated MCs-Try (P=0.0173). The α-SMA(+) fibroblasts correlated with high density of intact MCs-Try in PT, and with high density of degranulated MCs-Try in T (P=0.0289), also confirmed by ultrastructural analysis.

CONCLUSIONS

This preliminary investigation suggests that during breast cancer progression the MCs may contribute to stromal remodelling and differentiation of myofibroblasts, through tryptase released in stromal microenvironment.