Differential Expression of Human Tissue Factor in Normal Mammary Epithelial Cells and in Carcinomas

Advances in PET/CT Imaging for Breast Cancer

One out of eight women will be affected by breast cancer during her lifetime. Imaging plays a key role in breast cancer detection and management, providing physicians with information about tumor location, heterogeneity, and dissemination. In this review, we describe the latest advances in PET/CT imaging of breast cancer, including novel applications of 18F-FDG PET/CT and the development and testing of new agents for primary and metastatic breast tumor imaging and therapy. Ultimately, these radiopharmaceuticals may guide personalized approaches to optimize treatment based on the patient's specific tumor profile, and may become a new standard of care. In addition, they may enhance the assessment of treatment efficacy and lead to improved outcomes for patients with a breast cancer diagnosis.

Breast cancer stromal clotting activation (Tissue Factor and thrombin): A pre-invasive phenomena that is prognostic in invasion

Background

Tumor stroma, of which fibroblasts are the most abundant cell, resembles a non‐healing wound, where a procoagulant environment creates a permissive milieu for cancer growth. We aimed to determine if tumor expression of coagulation factors (procoagulant phenotype), and systemic hypercoagulability, occur at the preinvasive (ductal carcinoma in situ; DCIS) stage and correlate with breast cancer subtype, disease‐free survival (DFS), and overall survival (OS).

Methods

In a prospective cohort of early breast cancer (DCIS, n = 76; invasive, n = 248) tumor, normal breast and plasma were examined. Fibroblast and epithelial expression of Tissue Factor (TF), thrombin, PAR1, PAR2, and plasma thrombin‐antithrombin (TAT) and D‐dimer were correlated with clinicopathological data, and 5‐year survival.

Results

Fibroblast expression of TF, thrombin, and PAR1 was increased in DCIS and invasive cancer compared to normal breast fibroblasts (P ≤ .003, all). Fibroblast TF, thrombin, PAR1, and PAR2 was increased in cancers with high Ki67, high grade, ER‐ (vs ER+), and HER2+ (vs HER2‐) (all P < .05). On univariate analysis, fibroblast TF expression was inversely associated with DFS (P = .04) and OS (P = .02). D‐dimer was higher in node positive (507 (CI: 411‐625) ng/mL, n = 68) vs negative patients (428 (CI: 387‐472) ng/mL, n = 171, P = .004) and inversely associated with OS (P = .047). On multivariate analysis, plasma TAT was associated with reduced OS (HR 3.26, CI 1.16‐3.1, P = .02), with a high plasma TAT (≥3.2 ng/mL) associated with > 3‐fold mortality risk compared to low TAT.

Conclusion

This demonstrates procoagulant phenotypic changes occur in fibroblasts at the preinvasive stage. Fibroblast procoagulant phenotype is associated with aggressive breast cancer subtypes and reduced survival. Coagulation may be a therapeutic target in breast cancer.

The role of microRNA-27a/b and microRNA-494 in estrogen-mediated downregulation of tissue factor pathway inhibitor α

Essentials Estrogens are known to influence the expression of microRNAs in breast cancer cells. We looked at microRNAs in estrogenic regulation of tissue factor pathway inhibitor α (TFPIα). Estrogen upregulated microRNA-27a/b and microRNA-494 through the estrogen receptor α. MicroRNA-27a/b and microRNA-494 are partly involved in estrogenic downregulation of TFPIα.

SUMMARY

Background Tissue factor pathway inhibitor (TFPI) has been linked to breast cancer pathogenesis. We have recently reported TFPI mRNA levels to be downregulated by estrogens in a breast cancer cell line (MCF7) through the estrogen receptor α (ERα). Accumulating evidence also indicates that activation of ERα signaling by estrogens may modulate the expression of target genes indirectly through microRNAs (miRNAs). Objectives To examine if miRNAs are involved in the estrogenic downregulation of TFPIα. Methods Computational analysis of the TFPI 3'-untranslated region (UTR) identified potential binding sites for miR-19a/b, miR-27a/b, miR-494, and miR-24. Transient overexpression or inhibition of the respective miRNAs was achieved by transfection of miRNA mimics or inhibitors. Direct targeting of TFPI 3'-UTR by miR-27a/b and miR-494 was determined by luciferase reporter assay in HEK293T cells. Effects of 17α-ethinylestradiol (EE2) and fulvestrant on relative miR-27a/b, miR-494, and TFPI mRNA levels in MCF7 cells were determined by qRT-PCR and secreted TFPIα protein by ELISA. Transient knockdown of ERα was achieved by siRNA transfection. Results EE2 treatment lead to a significant increase in miR-19a, miR-27a/b, miR-494, and miR-24 mRNA levels in MCF7 cells through ERα. miR-27a/b and miR-494 mimics lead to reduced TFPI mRNA and protein levels. Luciferase assay showed direct targeting of miR-27a/b and miR-494 on TFPI mRNA. Impaired estrogen-mediated downregulation of TFPI mRNA was detected in anti-miR-27a/b and anti-miR-494 transfected cells. Conclusions Our results provide evidence that miR-27a/b and miR-494 regulate TFPIα expression and suggest a possible role of these miRNAs in the estrogen-mediated downregulation of TFPIα.

Feasibility of whole RNA sequencing from single-cell mRNA amplification

Single-cell sampling with RNA-seq analysis plays an important role in reference laboratory; cytogenomic diagnosis for specimens on glass-slides or rare cells in circulating blood for tumor and genetic diseases; measurement of sensitivity and specificity in tumor-tissue genomic analysis with mixed-cells; mechanism analysis of differentiation and proliferation of cancer stem cell for academic purpose. Our single- cell RNA-seq technique shows that fragments were 250-450 bp after fragmentation, amplification, and adapter addition. There were 11.6 million reads mapped in raw sequencing reads (19.6 million). The numbers of mapped genes, mapped transcripts, and mapped exons were 31,332, 41,210, and 85,786, respectively. All QC results demonstrated that RNA-seq techniques could be used for single-cell genomic performance. Analysis of the mapped genes showed that the number of genes mapped by RNA-seq (6767 genes) was much higher than that of differential display (288 libraries) among similar specimens which we have developed and published. The single-cell RNA-seq can detect gene splicing using different subtype TGF-beta analysis. The results from using Q-rtPCR tests demonstrated that sensitivity is 76% and specificity is 55% from single-cell RNA-seq technique with some gene expression missing (2/8 genes). However, it will be feasible to use RNA-seq techniques to contribute to genomic medicine at single-cell level.

TFPIα and TFPIβ are expressed at the surface of breast cancer cells and inhibit TF-FVIIa activity

BACKGROUND

Tissue factor (TF) pathway inhibitor-1 (TFPI) is expressed in several malignant tissues- and cell lines and we recently reported that it possesses anti-tumor effects in breast cancer cells, indicating a biological role of TFPI in cancer. The two main splice variants of TFPI; TFPIα and TFPIβ, are both able to inhibit TF-factor VIIa (FVIIa) activity in normal cells, but only TFPIα circulates in plasma. The functional importance of TFPIβ is therefore largely unknown, especially in cancer cells. We aimed to characterize the expression and function of TFPIα, TFPIβ, and TF in a panel of tumor derived breast cancer cell lines in comparison to normal endothelial cells.

METHODS

TFPIα, TFPIβ, and TF mRNA and protein measurements were conducted using qRT-PCR and ELISA, respectively. Cell-associated TFPI was detected after phosphatidylinositol-phospholipase C (PI-PLC) and heparin treatment by flow cytometry, immunofluorescence, and Western blotting. The potential anticoagulant activity of cell surface TFPI was determined in a factor Xa activity assay.

RESULTS

The expression of both isoforms of TFPI varied considerably among the breast cancer cell lines tested, from no expression in Sum149 cells to levels above or in the same range as normal endothelial cells in Sum102 and MDA-MB-231 cells. PI-PLC treatment released both TFPIα and TFPIβ from the breast cancer cell membrane and increased TF activity on the cell surface, showing TF-FVIIa inhibitory activity of the glycosylphosphatidylinositol- (GPI-) anchored TFPI. Heparin treatment released TFPIα without decreasing the cell surface levels, thus indicating the presence of intracellular storage pools of TFPIα in the breast cancer cells.

CONCLUSION

GPI-attached TFPI located at the surface of breast cancer cells inhibited TF activity and could possibly reduce TF signaling and breast cancer cell growth locally, indicating a therapeutic potential of the TFPIβ isoform.

Evaluation of tissue factor expression in canine tumor cells

OBJECTIVE

To determine whether canine tumor cell lines express functional tissue factor and shed tissue factor-containing microparticles.

SAMPLE

Cell lines derived from tumors of the canine mammary gland (CMT12 and CMT25), pancreas (P404), lung (BACA), prostate gland (Ace-1), bone (HMPOS, D-17, and OS2.4), and soft tissue (A72); from normal canine renal epithelium (MDCK); and from a malignant human mammary tumor (MDA-MB-231).

PROCEDURES

Tissue factor mRNA and antigen expression were evaluated in cells by use of canine-specific primers in a reverse transcriptase PCR assay and a rabbit polyclonal anti-human tissue factor antibody in flow cytometric and immunofluorescent microscopic assays, respectively. Tissue factor procoagulant activity on cell surfaces, in whole cell lysates, and in microparticle pellets was measured by use of an activated factor X-dependent chromogenic assay.

RESULTS

Canine tissue factor mRNA was identified in all canine tumor cells. All canine tumor cells expressed intracellular tissue factor; however, the HMPOS and D-17 osteosarcoma cells lacked surface tissue factor expression and activity. The highest tissue factor expression and activity were observed in canine mammary tumor cells and pulmonary carcinoma cells (BACA). These 3 tumors also shed tissue factor-bearing microparticles into tissue culture supernatants.

CONCLUSIONS AND CLINICAL RELEVANCE

Tissue factor was constitutively highly expressed in canine tumor cell lines, particularly those derived from epithelial tumors. Because tumor-associated tissue factor can promote tumor growth and metastasis in human patients, high tissue factor expression could affect the in vivo biological behavior of these tumors in dogs.

Tissue factor and tumor: clinical and laboratory aspects

This review summarizes data demonstrating the role of TF in tumor development, metastasis and angiogenesis. TF is a transmembrane protein that is expressed constitutively in some kinds of extravascular cells and transiently in intravascular cells after stimulation with cytokines and growth factors. Originally TF was considered to have a function in the initiation of coagulation. In the last years it became evident that TF plays a role in physiological and pathological processes outside the hemostasis. Up-regulation of TF expression appears to be characteristic of tumor tissue. In a variety of human tumors it was shown by immunohistochemistry, that TF can be expressed in malignant cells as well as in tumor-infiltrating macrophages or endothelial cells. Such abnormal TF expression contributes to the angiogenic process by a shift in the balance between endogenous proangiogenic and antiangiogenic factors. Observations of a significant correlation between elevated TF expression with increased microvessel density and VEGF expression underline the TF involvement in tumor angiogenesis. Furthermore, TF expression influences also metastasis. The effect of TF on metastasis may result from its angiogenic effect, but also from the production of growth factors or adhesion proteins.

A-432411, a novel indolinone compound that disrupts spindle pole formation and inhibits human cancer cell growth

Microtubules are among the most successful targets for anticancer therapies and for the development of new anticancer drugs. A-432411 is a novel small molecule that destabilizes microtubules at high concentration and disrupts normal spindle formation at low concentration. A-432411 is an indolinone that is structurally different from other known synthetic microtubule inhibitors. This compound is efficacious against a variety of human cancer cell lines including drug-resistant HCT-15 that overexpresses Pgp170. Biochemical studies show that A-432411 competes with the colchicine-binding site on tubulin and inhibits microtubule polymerization. Fluorescence-activated cell sorting analysis indicates that A-432411 causes G2-M arrest and induces apoptosis. Cells treated with A-432411 have increased level of phospho-histone H3 at Ser10 and decreased level of phospho-cdc2 at Tyr15. Concurrently, securin and cyclin B1 expression levels remain the same, indicating the activation of the spindle checkpoint. Immunocytochemistry and fluorescence microscopy experiments reveal that 1 micromol/L A-432411 destabilizes microtubules in cells. At 0.1 micromol/L, the compound disrupts normal spindle pole formation possibly through stabilization of microtubule dynamic. Both structural and cellular properties of A-432411 make it an attractive candidate for further development.

Changes of the coagulation and fibrinolysis system in malignancy: their possible impact on future diagnostic and therapeutic procedures

The interaction between malignant cell growth and the coagulation and fibrinolysis system has been a well known phenomenon for decades. During recent years, this area of research has received new attention. Experimental data suggest a role for the coagulation and fibrinolysis system in tumor development, progression and metastasis. Also, clinical research suggests that targeting the coagulation system or fibrinolysis system might influence the course of malignant disease beneficially. This paper reviews data on various hemostatic and fibrinolytic parameters in malignancy; the possible use of such parameters as risk markers in oncology patients; and possible targets of anti-neoplastic therapies using anticoagulant and/or antifibrinolytic strategies. Current evidence suggests that the tissue factor/factor VIIa pathway mediates the most abundant procoagulant stimulus in malignancy via the increase in thrombin generation. Tissue factor has been suggested to mediate pro-metastatic properties via coagulation-dependent and coagulation-independent pathways; tissue factor has also been implicated in tumor neo-angiogenesis. However, so far no model has been validated that would allow the use of tissue factor in its soluble or insoluble form as a marker for risk stratification in tumor patients. On the other hand, there is now good evidence that parts of the fibrinolytic system, such as urokinase-type plasminogen activator and its receptor ("uPAR"), can be used as strong predictors of outcome in several types of cancer, specifically breast cancer. Observation of various treatment options in patients with thromboembolic disease and cancer as well as attempts to use anticoagulants and/or therapies modulating the fibrinolytic system as anti-neoplastic treatment strategies have yielded exciting results. These data indicate that anticoagulant therapy, and specifically low molecular weight heparin therapy, is likely to have anti-neoplastic effects; and that their use in addition to chemotherapy will probably improve outcome of tumor treatment in certain types of cancer. However, the body of clinical data is still relatively small and the question whether or not we should routinely consider the coagulation and/or fibrinolysis system as therapeutic targets in cancer patients is yet to be answered.

Tissue factor expressed in pituitary adenoma cells contributes to the development of vascular events in pituitary adenomas

BACKGROUND

Tissue factor (TF) was initially identified as an important factor in the initiation of coagulation. TF has recently been found to be expressed highly in certain types of malignant tumors. It has also been reported to be involved in systemic coagulopathy in cancer patients and in the proliferative and invasive activities of tumor cells. Tissue factor pathway inhibitor (TFPI) is a strong biologic inhibitor of TF. To the authors' knowledge, this is the first study of the expression of TF and TFPI in human pituitary adenoma.

METHODS

The expression of TF and TFPI were analyzed by immunohistochemical methods in human pituitary adenoma samples. To examine whether TF and TFPI expression influence the proliferative and/or invasive character of pituitary adenomas, the authors determined the MIB-1 labeling indices and invasiveness of all the pituitary adenomas they examined. Furthermore, to determine whether TF contributes to coagulation inside adenoma tissues, the incidence of cysts or hematomas in adenomas was analyzed.

RESULTS

In cells from 29 of 83 pituitary adenomas, overexpression of TF was observed. This was not the case for normal pituitary gland cells. TFPI was not expressed in either the adenomas or the normal pituitary glands from adenoma-bearing individuals. The expression of TF was significantly correlated with the formation of cysts or hematomas in pituitary adenomas. However, no such correlation with either the proliferative activity or the invasive character of the adenomas was observed.

CONCLUSIONS

Locally overexpressed TF in adenoma cells may contribute to the development of vascular events, such as infarction and/or hemorrhagic infarction, in pituitary adenomas.

mRNA differential display of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine-induced rat mammary gland tumors

The mRNA differential display technique was used to compare mRNAs between normal mammary gland and tumor-derived epithelial cells from female Sprague-Dawley rat mammary gland tumors induced by the heterocyclic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and promoted by a high-fat diet (23.5% corn oil). Two genes, beta-casein and transferrin, were identified as differentially expressed. The expression of these genes was examined across a bank of rat mammary gland tumors derived from animals on a low-fat diet (5% corn oil) or the high-fat diet. Carcinomas had over a 10- and 50-fold lower expression of beta-casein and transferrin, respectively, than normal mammary gland. In addition, carcinomas from animals on the high-fat diet showed on average a 5-fold higher expression of beta-casein and transferrin than carcinomas from animals on the low-fat diet. The results indicate the process of mammary gland tumorigenesis alters the expression of certain genes in the mammary gland, and that the level of dietary fat further modulates the expression of these genes.

Overexpression of ribosomal proteins L4 and L5 and the putative alternative elongation factor PTI-1 in the doxorubicin resistant human colon cancer cell line LoVoDxR

A better understanding of the regulatory network underlying cellular drug resistance and stress response may be helpful to overcome the phenomenon of therapy-induced cross-resistances against a variety of antineoplastic agents. Two new powerful molecular techniques, mRNA differential display reverse transcriptase polymerase chain reaction (DDRT-PCR) and subtractive suppressive hybridisation were applied for the comparative analysis of the gene expression profile of a doxorubicin resistant and its corresponding sensitive parental colon carcinoma cell line (LoVo H67P). DDRT-PCR generated partial cDNAs from the doxorubicin resistant, sensitive and stress (dexamethasone, doxorubicin, cadmium chloride or heat) exposed sensitive cells, were size-separated on polyacrylamide gels. The expression patterns of more than 9000 bands of the resistant, sensitive and stressed sensitive cell populations were identical by more than 95%. Of the differentially expressed mRNAs, 20 cDNA fragments were reamplified after isolation from the gel, used as probes for Northern blot analysis to verify their differential expression and sequenced after cloning. Among the differentially expressed cDNAs, homologies of 96% and 87%, respectively, were found to the human proto-oncogene PTI-1 and the human ribosomal protein L4. Subtractive suppressive hybridisation revealed overexpression of the ribosomal protein L5 in the doxorubicin resistant line. These data point to the control of gene expression at the translational level as an important mechanism involved in cellular stress response.

Immunological and functional analyses of the extracellular domain of human tissue factor

Tissue factor (TF) initiates the extrinsic pathway of blood coagulation via formation of an enzymatic complex with coagulation factor VII/VIIa (FVII/VIIa). Although FVII is the only known ligand for TF, several reports in recent years have shown that the function of TF may not be limited to serving as a trigger of coagulation but that TF could also play a role in cellular signaling, metastasis, adhesion and embryogenesis. To explore the loci of the extracellular domain of TF important for its function, we analyzed the functional and immunological epitopes of TF1-219 by the use of both E. coli expressed TF variants encompassing various portions of the extracellular domain of TF and different anti-TF monoclonal antibodies (mAbs). N- and C-terminally truncated TF variants were analyzed for their VIIa-dependent procoagulant activity (PCA). The results obtained are in agreement with previously performed mutant and structural analyses of the interaction of FVII/FVIIa with the extracellular domain of TF. In addition, we observed that combination of two TF variants, Ec-TF1-122 and Ec-TF120-219, yields a soluble and active two-chain TF molecule with remarkable PCA. The reaction patterns of anti-TF mAbs with truncated TF variants and synthetic TF-derived peptides demonstrated that at least three distinct conformation-dependent epitope areas of TF (residues 1-25, 175-202, and 181 -214, respectively) are detected by these mAbs raised against native TF. In fact, mAbs, which are directed to the same epitope area of TF, behave very similar in various applications including immunohistochemistry and clotting tests. Since mAbs directed to the C-terminal epitope area of TF (residues 181-214) influence TF activity independent of FVIIa-binding, this region may be involved in functions of TF distinct from haemostasis.