The two faces of transforming growth factor beta in carcinogenesis

Association of TGF-β2 levels in breast milk with severity of breast biopsy diagnosis

PURPOSE

TGF-β plays a dual role in breast carcinogenesis, acting at early stages as tumor-suppressors and later as tumor-promoters. TGF-β isoforms are expressed in breast tissues and secreted in milk, suggesting that analysis of levels in milk might be informative for breast cancer risk. Accordingly, we assessed TGF-β2 levels in milk from women who had undergone a breast biopsy and related the concentrations to diagnosis.

METHODS

Milk donated by women who had undergone or were scheduled for a breast biopsy was shipped on ice for processing and testing. Breast cancer risk factors were obtained through a self-administered questionnaire, and biopsy diagnoses were extracted from pathology reports. TGF-β2 levels in milk, assessed as absolute levels and in relation to total protein, were analyzed in bilateral samples donated by 182 women. Linear regression was used to estimate relationships of log-transformed TGF-β2 levels and TGF-β2/ total protein ratios to biopsy category.

RESULTS

Milk TGF-β2 levels from biopsied and non-biopsied breasts within women were highly correlated (r (2) = 0.77). Higher mean TGF-β2 milk levels (based on average of bilateral samples) were marginally associated with more severe breast pathological diagnosis, after adjusting for duration of nursing current child (adjusted p trend = 0.07).

CONCLUSIONS

Our exploratory analysis suggests a borderline significant association between higher mean TGF-β2 levels in breast milk and more severe pathologic diagnoses. Further analysis of TGF-β signaling in milk may increase understanding of postpartum remodeling and advance efforts to analyze milk as a means of assessing risk of breast pathology.

Long non-coding RNAs (LncRNA) regulated by transforming growth factor (TGF) β: LncRNA-hit-mediated TGFβ-induced epithelial to mesenchymal transition in mammary epithelia

Long noncoding RNAs (lncRNAs) are emerging as key regulators in various biological processes. Epithelial-to-mesenchymal transition (EMT) is a developmental process hijacked by tumor cells to depart from the primary tumor site, invade surrounding tissue, and establish distant metastases. Transforming growth factor β (TGFβ) signaling has been shown to be a major inducer of EMT and to facilitate breast cancer metastasis. However, the role of lncRNAs in this process remains largely unknown. Here we report a genome-wide lncRNA profile in mouse mammary epithelial NMuMG cells upon TGFβ induction of EMT. Among 10,802 lncRNAs profiled, over 600 were up-regulated and down-regulated during the EMT, respectively. Furthermore, we identify that lncRNA-HIT (HOXA transcript induced by TGFβ) mediates TGFβ function, i.e. depletion of lncRNA-HIT inhibits TGFβ-induced migration, invasion, and EMT in NMuMG. LncRNA-HIT is also significantly elevated in the highly metastatic 4T1 cells. Knockdown of lncRNA-HIT in 4T1 results in decrease of cell migration, invasion, tumor growth, and metastasis. E-cadherin was identified as a major target of lncRNA-HIT. Moreover, lncRNA-HIT is conserved in humans and elevated expression associates with more invasive human primary breast carcinoma. Collectively, these data suggest that a subset of lncRNAs such as lncRNA-HIT play a significant role in regulation of EMT and breast cancer invasion and metastasis, and could be potential therapeutic targets in breast cancers.

Role of TGFβ in regulation of the tumor microenvironment and drug delivery (review)

Deregulation of cell signaling homeostasis is a predominant feature of cancer initiation and progression. Transforming growth factor β (TGFβ) is a pleiotropic cytokine, which regulates numerous biological processes of various tissues in an autocrine and paracrine manner. Aberrant activity of TGFβ signaling is well known to play dual roles in cancer, depending on tumor stage and cellular context. The crucial roles of TGFβ in modulating the tumor microenvironment, its contribution to the accumulation of mechanical forces within the solid constituents of a tumor and its effects on the effective delivery of drugs are also becoming increasingly clear. In this review, we discuss the latest advances in the efforts to unravel the effects of TGFβ signaling in various components of the tumor microenvironment and how these influence the generation of forces and the efficacy of drugs. We also report the implications of tumor mechanics in cancer therapy and the potential usage of anti-TGFβ agents to enhance drug delivery and augment existing therapeutic approaches. These findings provide new insights towards the significance of targeting TGFβ pathway to enhance personalized tumor treatment.

H3K9 histone methyltransferase, KMT1E/SETDB1, cooperates with the SMAD2/3 pathway to suppress lung cancer metastasis

Aberrant histone methylation is a frequent event during tumor development and progression. KMT1E (also known as SETDB1) is a histone H3K9 methyltransferase that contributes to epigenetic silencing of both oncogenes and tumor suppressor genes in cancer cells. In this report, we demonstrate that KMT1E acts as a metastasis suppressor that is strongly downregulated in highly metastatic lung cancer cells. Restoring KMT1E expression in this setting suppressed filopodia formation, migration, and invasive behavior. Conversely, loss of KMT1E in lung cancer cells with limited metastatic potential promoted migration in vitro and restored metastatic prowess in vivo. Mechanistic investigations indicated that KMT1E cooperates with the TGFβ-regulated complex SMAD2/3 to repress metastasis through ANXA2. Together, our findings defined an essential role for the KMT1E/SMAD2/3 repressor complex in TGFβ-mediated lung cancer metastasis.

Cellular and molecular immunology of lung cancer: therapeutic implications

Although the incidence of lung cancer is declining, the prognosis remains poor. This is likely due to lack of early detection and only recent developments in selective cancer therapies. Key immune cells involved in the pathogenesis of lung cancer include CD4(+) T lymphocytes, macrophages, dendritic cells and NK cells. The growing understanding of these cells indicates a highly complex and intertwined network of their involvement in each stage of lung cancer. Immune cell types and numbers affect prognosis and could offer an opportunity for clinical therapeutic applications. However, an incomplete understanding of immune cell involvement and the underlying processes in lung cancer still remain. Deeper investigation focusing on the role of the immune cells will further the understanding of lung carcinogenesis and develop novel therapeutic approaches for the treatment and management of patients with more specialized and selective lung cancer.

Significance of expression of human METCAM/MUC18 in nasopharyngeal carcinomas and metastatic lesions

Human METCAM/MUC18, a cell adhesion molecule (CAM) in the immunoglobulin-like gene super family, plays a dual role in the progression of several epithelium cancers; however, its role in the nasopharyngeal carcinoma (NPC) remains unclear. To initiate the study we determined human METCAM/MUC18 expression in tissue samples of normal nasopharynx (NP), NPCs, and metastatic lesions, and in two established NPC cell lines. Immunoblotting analysis was used for the determination in lysates of frozen tissues, and immunohistochemistry (IHC) for expression in formalin-fixed, paraffin-embedded tissue sections of 7 normal nasopharynx specimens, 94 NPC tissue specimens, and 3 metastatic lesions. Human METCAM/MUC18 was expressed in 100% of the normal NP, not expressed in 73% of NPC specimens (or expressed at very low levels in only about 27% of NPC specimens), and expressed again in all of the metastatic lesions. The level of human METCAM/MUC18 expression in NPC tissues was about one fifth of that in the normal NP and metastatic lesions. The low level of human METCAM/ MUC18 expression in NPC specimens was confirmed by a weak signal of RT-PCR amplification of the mRNA. Low expression levels of human METCAM/MUC18 in NPC tissues were also reflected in the seven established NPC cell lines. These findings provided the first evidence that diminished expression of human METCAM/MUC18 is an indicator for the emergence of NPC, but increased expression then occurs with metastatic progression, suggesting that huMETCAM/MUC18, perhaps similar to TGF-β, may be a tumor suppressor, but a metastasis promoter for NPC.

β-Galactoside α2,6-sialyltranferase 1 promotes transforming growth factor-β-mediated epithelial-mesenchymal transition

β-Galactoside α2,6-sialyltranferase 1 (ST6GAL1) catalyzes the addition of terminal α2,6-sialylation to N-glycans. Increased expression of ST6GAL1 has been reported in diverse carcinomas and highly correlates with tumor progression. Here, we report that St6gal1 transcription and α2,6-sialylated N-glycans are up-regulated during TGF-β-induced epithelial-mesenchymal transition (EMT) in GE11 cells, requiring the Sp1 element within the St6gal1 promoter. Knockdown of St6gal1 strongly suppressed TGF-β-induced EMT with a concomitant increase in E-cadherin expression, a major determinant of epithelial cell adherens junctions. Conversely, overexpression of ST6GAL1 increased the turnover of cell surface E-cadherin and promoted TGF-β-induced EMT. Overexpressing β-galactoside α2,3-sialyltranferase 4 had little influence on EMT, indicating specificity for α2,6-sialylation. The basal mesenchymal phenotype of MDA-MB-231 human breast cancer cells was partially reversed by ST6GAL1 silencing. Moreover, ST6GAL1 knockdown inhibited the phosphorylation of Akt, but not Smad2, suggesting that ST6GAL1 contributes to EMT through a non-Smad signaling pathway. Taken together, our data indicate that ST6GAL1 promotes TGF-β-dependent EMT as well as maintenance of the mesenchymal state by growth signaling, providing a plausible mechanism whereby up-regulated ST6GAL1 may promote malignant progression.

Role of pyruvate kinase M2 in transcriptional regulation leading to epithelial-mesenchymal transition

Pyruvate kinase M2 (PKM2) is an alternatively spliced variant of the pyruvate kinase gene that is preferentially expressed during embryonic development and in cancer cells. PKM2 alters the final rate-limiting step of glycolysis, resulting in the cancer-specific Warburg effect (also referred to as aerobic glycolysis). Although previous reports suggest that PKM2 functions in nonmetabolic transcriptional regulation, its significance in cancer biology remains elusive. Here we report that stimulation of epithelial-mesenchymal transition (EMT) results in the nuclear translocation of PKM2 in colon cancer cells, which is pivotal in promoting EMT. Immunoprecipitation and LC-electrospray ionized TOF MS analyses revealed that EMT stimulation causes direct interaction of PKM2 in the nucleus with TGF-β-induced factor homeobox 2 (TGIF2), a transcriptional cofactor repressor of TGF-β signaling. The binding of PKM2 with TGIF2 recruits histone deacetylase 3 to the E-cadherin promoter sequence, with subsequent deacetylation of histone H3 and suppression of E-cadherin transcription. This previously unidentified finding of the molecular interaction of PKM2 in the nucleus sheds light on the significance of PKM2 expression in cancer cells.

Expression of TGF-β1 in Wilms' tumor was associated with invasiveness and disease progression

OBJECTIVE

To detect the expression of TGF-β1 in Wilms' tumor and association with disease progression.

METHODS

Immunohistochemistry was used to examine TGF-β1 expression in 51 primary tumors and 17 invasions/metastases. Transient transfection was performed to establish Wilms' tumor cells with high TGF-β1 expression (TGF-β1-WT), and the expression level of TGF-β1 was detected by Western blot analysis. Invasive capacity of the transfected cells was evaluated by transwell analysis.

RESULTS

The positive expression rate of TGF-β1 was 50.98% (26/51) and 82.35% (14/17) in primary WT tissues and associated invasive/metastatic tissues, respectively. The higher level of TGF-β1 expression in primary WT tumors was relative to invasion/metastasis (p = 0.048). The expression of TGF-β1 between primary WT and matched invasive/metastatic tissues was concordant (p = 0.219). TGF-β1-WT cells showed more invasive capacity than GFP-WT and WT cells. TGF-β1 expression status was associated with disease-free survival (DFS) (50.2 months vs. 75.4 months, p = 0.022) but not overall survival (OS) (62.3 months vs. 75.8 months, p = 0.141).

CONCLUSIONS

Positive expression of TGF-β1 in WT was correlated with tumor invasion and disease progression, which might be useful in identifying patients at high risk of unfavorable outcomes.

Bioinformatic approaches to augment study of epithelial-to-mesenchymal transition in lung cancer

Bioinformatic approaches are intended to provide systems level insight into the complex biological processes that underlie serious diseases such as cancer. In this review we describe current bioinformatic resources, and illustrate how they have been used to study a clinically important example: epithelial-to-mesenchymal transition (EMT) in lung cancer. Lung cancer is the leading cause of cancer-related deaths and is often diagnosed at advanced stages, leading to limited therapeutic success. While EMT is essential during development and wound healing, pathological reactivation of this program by cancer cells contributes to metastasis and drug resistance, both major causes of death from lung cancer. Challenges of studying EMT include its transient nature, its molecular and phenotypic heterogeneity, and the complicated networks of rewired signaling cascades. Given the biology of lung cancer and the role of EMT, it is critical to better align the two in order to advance the impact of precision oncology. This task relies heavily on the application of bioinformatic resources. Besides summarizing recent work in this area, we use four EMT-associated genes, TGF-β (TGFB1), NEDD9/HEF1, β-catenin (CTNNB1) and E-cadherin (CDH1), as exemplars to demonstrate the current capacities and limitations of probing bioinformatic resources to inform hypothesis-driven studies with therapeutic goals.

Activin A balance regulates epithelial invasiveness and tumorigenesis

Activin A (Act A) is a member of the TGFβ superfamily. Act A and TGFβ have multiple common downstream targets and have been described to merge in their intracellular signaling cascades and function. We have previously demonstrated that coordinated loss of E-cadherin and TGFβ receptor II (TβRII) results in epithelial cell invasion. When grown in three-dimensional organotypic reconstruct cultures, esophageal keratinocytes expressing dominant-negative mutants of E-cadherin and TβRII showed activated Smad2 in the absence of functional TβRII. However, we could show that increased levels of Act A secretion was able to induce Smad2 phosphorylation. Growth factor secretion can activate autocrine and paracrine signaling, which affects crosstalk between the epithelial compartment and the surrounding microenvironment. We show that treatment with the Act A antagonist Follistatin or with a neutralizing Act A antibody can increase cell invasion in organotypic cultures in a fibroblast- and MMP-dependent manner. Similarly, suppression of Act A with shRNA increases cell invasion and tumorigenesis in vivo. Therefore, we conclude that maintaining a delicate balance of Act A expression is critical for homeostasis in the esophageal microenvironment.

Berberine reverses epithelial-to-mesenchymal transition and inhibits metastasis and tumor-induced angiogenesis in human cervical cancer cells

Metastasis is the most common cause of cancer-related death in patients, and epithelial-to-mesenchymal transition (EMT) is essential for cancer metastasis, which is a multistep complicated process that includes local invasion, intravasation, extravasation, and proliferation at distant sites. When cancer cells metastasize, angiogenesis is also required for metastatic dissemination, given that an increase in vascular density will allow easier access of tumor cells to circulation, and represents a rational target for therapeutic intervention. Berberine has several anti-inflammation and anticancer biologic effects. In this study, we provided molecular evidence that is associated with the antimetastatic effect of berberine by showing a nearly complete inhibition on invasion (P < 0.001) of highly metastatic SiHa cells via reduced transcriptional activities of matrix metalloproteinase-2 and urokinase-type plasminogen activator. Berberine reversed transforming growth factor-β1-induced EMT and caused upregulation of epithelial markers such as E-cadherin and inhibited mesenchymal markers such as N-cadherin and snail-1. Selective snail-1 inhibition by snail-1-specific small interfering RNA also showed increased E-cadherin expression in SiHa cells. Berberine also reduced tumor-induced angiogenesis in vitro and in vivo. Importantly, an in vivo BALB/c nude mice xenograft model and tail vein injection model showed that berberine treatment reduced tumor growth and lung metastasis by oral gavage, respectively. Taken together, these findings suggested that berberine could reduce metastasis and angiogenesis of cervical cancer cells, thereby constituting an adjuvant treatment of metastasis control.

Definition of smad3 phosphorylation events that affect malignant and metastatic behaviors in breast cancer cells

Smad3, a major intracellular mediator of TGFβ signaling, functions as both a positive and negative regulator in carcinogenesis. In response to TGFβ, the TGFβ receptor phosphorylates serine residues at the Smad3 C-tail. Cancer cells often contain high levels of the MAPK and CDK activities, which can lead to the Smad3 linker region becoming highly phosphorylated. Here, we report, for the first time, that mutation of the Smad3 linker phosphorylation sites markedly inhibited primary tumor growth, but significantly increased lung metastasis of breast cancer cell lines. In contrast, mutation of the Smad3 C-tail phosphorylation sites had the opposite effect. We show that mutation of the Smad3 linker phosphorylation sites greatly intensifies all TGFβ-induced responses, including growth arrest, apoptosis, reduction in the size of putative cancer stem cell population, epithelial-mesenchymal transition, and invasive activity. Moreover, all TGFβ responses were completely lost on mutation of the Smad3 C-tail phosphorylation sites. Our results demonstrate a critical role of the counterbalance between the Smad3 C-tail and linker phosphorylation in tumorigenesis and metastasis. Our findings have important implications for therapeutic intervention of breast cancer.

Caveolin-1 in oral squamous cell carcinoma microenvironment: an overview

Caveolin-1 plays an important role in the pathogenesis of oncogenic cell transformation, tumorigenesis, and metastasis. Increased expression of caveolin-1 in an array of tumors has confirmed its value in prognosis. It has been established that oxidative stress is the main cause for loss of stromal caveolin-1 via autophagy in the tumor microenvironment. In this overview, we attempt to abridge the relationship between caveolin-1 and oral squamous cell carcinoma, taking all the established theories into consideration.

An in vitro retinoblastoma human triple culture model of angiogenesis: a modulatory effect of TGF-β

Retinoblastoma is the most common intraocular tumour in children. In view of understanding the molecular mechanisms through which angiogenic switch on happens in the early phases of reciprocal interaction between tumour and cells constituting retinal microvessel, Transwell co-cultures constituted by human retinal endothelial cells (HREC), pericytes (HRPC), and human retinoblastoma cell line Y-79 were performed. Y-79 enhanced HREC proliferation, reduced by the introduction of HRPC in triple culture. In HREC/HRPC cultures, TGF-β in media increased, decreasing in triple cultures. High VEGF levels in triple cultures witnessed the establishment of a strongly in vitro angiogenic environment. Y-79 induced in HREC an increase in c- and iPLA2, phospho-cPLA2, inducible COX-2 protein expressions, PLA2 activities and prostaglandin E2 (PGE2) release. These effects were attenuated when HRPC were introduced in triple culture. Moreover, antibody silencing of TGF-β demonstrated a strong correlation between the signalling pathway triggered by TGF-β of pericytal origin and the phospholipase activation and the modulation of PGE2 release. Inhibiting VEGFA effect, the HRPC loss in triple culture decreased, showing its modulatory effect on their survival. Relying on the data here presented, sustaining the pericytal survival in a tumour retinal environment could ensure the integrity of microvessels and the TGF-β supply, essential for controlling aberrant endothelial pruning and angiogenesis.

Effect of truncated neurokinin-1 receptor expression changes on the interaction between human breast cancer and bone marrow-derived mesenchymal stem cells

Previous studies in breast cancer cell lines showed that truncated neurokinin receptor-1 (NK1R-Tr) was able to promote malignant transformation of breast cells, and NK1R-Tr may contribute to tumor progression and promote distant metastasis in human breast cancer. A co-culture model of breast cancer and bone marrow-derived human mesenchymal stem (HMSC-bm) cells showed that HMSC-bm inhibited the growth of breast cancer cells and entered the bone marrow at early stages. Down-regulation of NK1R-Tr may be a key factor in maintaining the quiescent phenotype of breast cancer cells among bone marrow stroma. Stromal-derived factor (SDF)-1α expression was negatively correlated with NK1R-Tr expression in breast cancer cells. Secretion of SDF-1α by HMSC-bm may maintain the quiescent phenotype of breast cancer cells among bone marrow stroma by down-regulating NK1R-Tr expression. Transforming growth factor (TGF)-β1 expression was positively associated with NK1R-Tr expression in breast cancer cells. In a co-culture system, MDA-MB-231-TGF-β1I (TGF-β genes were suppressed using specific shRNA) cells were able to attach to HMSC-bm quickly, indicating that TGF-β1 was also a key factor for maintaining the quiescent phenotype of breast cancer cells in bone marrow stroma. However, the detailed mechanism still remained unclear and could involve other molecules, in addition to NK1R-Tr.

Transforming growth factor-β-induced lncRNA-Smad7 inhibits apoptosis of mouse breast cancer JygMC(A) cells

Transforming growth factor (TGF)-β exhibits both pro-apoptotic and anti-apoptotic effects on epithelial cells in a context-dependent manner. The anti-apoptotic function of TGF-β is mediated by several downstream regulatory mechanisms, and has been implicated in the tumor-progressive phenotype of breast cancer cells. We conducted RNA sequencing of mouse mammary gland epithelial (NMuMG) cells and identified a long non-coding RNA, termed lncRNA-Smad7, which has anti-apoptotic functions, as a target of TGF-β. lncRNA-Smad7 was located adjacent to the mouse Smad7 gene, and its expression was induced by TGF-β in all of the mouse mammary gland epithelial cell lines and breast cancer cell lines that we evaluated. Suppression of lncRNA-Smad7 expression cancelled the anti-apoptotic function of TGF-β. In contrast, forced expression of lncRNA-Smad7 rescued apoptosis induced by a TGF-β type I receptor kinase inhibitor in the mouse breast cancer cell line JygMC(A). The anti-apoptotic effect of lncRNA-Smad7 appeared to occur independently of the transcriptional regulation by TGF-β of anti-apoptotic DEC1 and pro-apoptotic Bim proteins. Small interfering RNA for lncRNA-Smad7 did not alter the process of TGF-β-induced epithelial-mesenchymal transition, phosphorylation of Smad2 or expression of the Smad7 gene, suggesting that the contribution of this lncRNA to TGF-β functions may be restricted to apoptosis. Our findings suggest a complex mechanism for regulating the anti-apoptotic and tumor-progressive aspects of TGF-β signaling.

Growth inhibition after exposure to transforming growth factor-β1 in human bladder cancer cell lines

Purpose

Transforming growth factor-β1 (TGF-β1) plays a dual role in apoptosis and in proapoptotic responses in the support of survival in a variety of cells. The aim of this study was to determine the function of TGF-β1 in bladder cancer cells.

Materials and Methods

The role of TGF-β1 in bladder cancer cells was examined by observing cell viability by using the tetrazolium dye (MTT) assay after treating the bladder cancer cell lines 253J, 5637, T24, J82, HT1197, and HT1376 with TGF-β1. Among these cell lines, the 253J and T24 cell lines were coincubated with TGF-β1 and the pan anti-TGF-β antibody. Fluorescence-activated cell sorter (FACS) analysis was performed to determine the mechanism involved after TGF-β1 treatment in 253J cells.

Results

All six cell lines showed inhibited cellular growth after TGF-β1 treatment. Although the T24 and J82 cell lines also showed inhibited cellular growth, the growth inhibition was less than that observed in the other 4 cell lines. The addition of pan anti-TGF-β antibodies to the culture media restored the growth properties that had been inhibited by TGF-β1. FACS analysis was performed in the 253J cells and the 253J cells with TGF-β1. There were no significant differences in the cell cycle between the two treatments. However, there were more apoptotic cells in the TGF-β1-treated 253J cells.

Conclusions

TGF-β1 did not stimulate cellular proliferation but was a growth inhibitory factor in bladder cancer cells. However, the pattern of its effects depended on the cell line. TGF-β1 achieved growth inhibition by enhancing the level of apoptosis.

Influence of secreted frizzled receptor protein 1 (SFRP1) on neoadjuvant chemotherapy in triple negative breast cancer does not rely on WNT signaling

BACKGROUND

Triple negative breast cancer (TNBC) is characterized by lack of expression of both estrogen and progesterone receptor as well as lack of overexpression or amplification of HER2. Despite an increased probability of response to chemotherapy, many patients resistant to current chemotherapy regimens suffer from a worse prognosis compared to other breast cancer subtypes. However, molecular determinants of response to chemotherapy specific to TNBC remain largely unknown. Thus, there is a high demand for biomarkers potentially stratifying triple negative breast cancer patients for neoadjuvant chemotherapies or alternative therapies.

METHODS

In order to identify genes correlating with both the triple negative breast cancer subtype as well as response to neoadjuvant chemotherapy we employed publicly available gene expression profiles of patients, which had received neoadjuvant chemotherapy. Analysis of tissue microarrays as well as breast cancer cell lines revealed correlation to the triple negative breast cancer subtype. Subsequently, effects of siRNA-mediated knockdown on response to standard chemotherapeutic agents as well as radiation therapy were analyzed. Additionally, we evaluated the molecular mechanisms by which SFRP1 alters the carcinogenic properties of breast cancer cells.

RESULTS

SFRP1 was identified as being significantly overexpressed in TNBC compared to other breast cancer subtypes. Additionally, SFRP1 expression is significantly correlated with an increased probability of positive response to neoadjuvant chemotherapy. Knockdown of SFRP1 in triple negative breast cancer cells renders the cells more resistant to standard chemotherapy. Moreover, tumorigenic properties of the cells are modified by knockdown, as shown by both migration or invasion capacity as well reduced apoptotic events. Surprisingly, we found that these effects do not rely on Wnt signaling. Furthermore, we show that pro-apoptotic as well as migratory pathways are differentially regulated after SFRP1 knockdown.

CONCLUSION

We could firstly show that SFRP1 strongly correlates with the triple negative breast cancer subtype and secondly, that SFRP1 might be used as a marker stratifying patients to positively respond to neoadjuvant chemotherapy. The mechanisms by which tumor suppressor SFRP1 influences carcinogenic properties of cancer cells do not rely on Wnt signaling, thereby demonstrating the complexity of tumor associated signaling pathways.

TGF- β Signaling Cooperates with AT Motif-Binding Factor-1 for Repression of the α -Fetoprotein Promoter

α-Fetoprotein (AFP) is known to be highly produced in fetal liver despite its barely detectable level in normal adult liver. On the other hand, hepatocellular carcinoma often shows high expression of AFP. Thus, AFP seems to be an oncogenic marker. In our present study, we investigated how TGF-β signaling cooperates with AT motif-binding factor-1 (ATBF1) to inhibit AFP transcription. Indeed, the expression of AFP mRNA in HuH-7 cells was negatively regulated by TGF-β signaling. To further understand how TGF-β suppresses the transcription of the AFP gene, we analyzed the activity of the AFP promoter in the presence of TGF-β. We found that the TGF-β signaling and ATBF1 suppressed AFP transcription through two ATBF1 binding elements (AT-motifs). Using a heterologous reporter system, both AT-motifs were required for transcriptional repression upon TGF-β stimulation. Furthermore, Smads were found to interact with ATBF1 at both its N-terminal and C-terminal regions. Since the N-terminal (ATBF1N) and C-terminal regions of ATBF1 (ATBF1C) lack the ability of DNA binding, both truncated mutants rescued the cooperative inhibitory action by the TGF-β signaling and ATBF1 in a dose-dependent manner. Taken together, these findings indicate that TGF-β signaling can act in concert with ATBF1 to suppress the activity of the AFP promoter through direct interaction of ATBF1 with Smads.

Transforming growth factor beta receptor type III is a tumor promoter in mesenchymal-stem like triple negative breast cancer

Introduction

There is a major need to better understand the molecular basis of triple negative breast cancer (TNBC) in order to develop effective therapeutic strategies. Using gene expression data from 587 TNBC patients we previously identified six subtypes of the disease, among which a mesenchymal-stem like (MSL) subtype. The MSL subtype has significantly higher expression of the transforming growth factor beta (TGF-β) pathway-associated genes relative to other subtypes, including the TGF-β receptor type III (TβRIII). We hypothesize that TβRIII is tumor promoter in mesenchymal-stem like TNBC cells.

Methods

Representative MSL cell lines SUM159, MDA-MB-231 and MDA-MB-157 were used to study the roles of TβRIII in the MSL subtype. We stably expressed short hairpin RNAs specific to TβRIII (TβRIII-KD). These cells were then used for xenograft tumor studies in vivo; and migration, invasion, proliferation and three dimensional culture studies in vitro. Furthermore, we utilized human gene expression datasets to examine TβRIII expression patterns across all TNBC subtypes.

Results

TβRIII was the most differentially expressed TGF-β signaling gene in the MSL subtype. Silencing TβRIII expression in MSL cell lines significantly decreased cell motility and invasion. In addition, when TβRIII-KD cells were grown in a three dimensional (3D) culture system or nude mice, there was a loss of invasive protrusions and a significant decrease in xenograft tumor growth, respectively. In pursuit of the mechanistic underpinnings for the observed TβRIII-dependent phenotypes, we discovered that integrin-α2 was expressed at higher level in MSL cells after TβRIII-KD. Stable knockdown of integrin-α2 in TβRIII-KD MSL cells rescued the ability of the MSL cells to migrate and invade at the same level as MSL control cells.

Conclusions

We have found that TβRIII is required for migration and invasion in vitro and xenograft growth in vivo. We also show that TβRIII-KD elevates expression of integrin-α2, which is required for the reduced migration and invasion, as determined by siRNA knockdown studies of both TβRIII and integrin-α2. Overall, our results indicate a potential mechanism in which TβRIII modulates integrin-α2 expression to effect MSL cell migration, invasion, and tumorigenicity.

Tgf-Beta family signaling in embryonic stem cells

Ligands of transforming growth factor beta (TGF-β) family members have been implicated in the development and patho-physiological process of various organs. Embryonic stem cells (ESCs) are characterized by their ability to proliferate indefinitely and differentiated into all three germ layer cells, which are termed as pluripotency and self-renewal,respectively. For successful therapeutic application of ESCs, it is essential to understand the mechanisms underlying self-renewal and pluripotency, which involve complex networks among key factors including transcription factors, epigenetic control, microRNAs and signaling pathways. In this review, we discuss recent progress on the function of TGF beta family ligands and their canonical SMAD signaling in the maintenance of ESC' s identity.

Targeting the Transforming Growth Factor-β Signaling in Cancer Therapy

TGF-β pathway is being extensively evaluated as a potential therapeutic target. The transforming growth factor-β (TGF-β) signaling pathway has the dual role in both tumor suppression and tumor promotion. To design cancer therapeutics successfully, it is important to understand TGF-β related functional contexts. This review discusses the molecular mechanism of the TGF-β pathway and describes the different ways of tumor suppression and promotion by TGF-β. In the last part of the review, the data on targeting TGF-β pathway for cancer treatment is assessed. The TGF-β inhibitors in pre-clinical studies, and Phase I and II clinical trials are updated.

Expression of TGFβ-1 and EHD1 correlated with survival of non-small cell lung cancer

Transforming growth factor-β1 (TGFβ-1) signaling is regulated by endocytotic pathway. To clarify the prognostic value of TGFβ-1 and to verify the involvement of endocytosis in drug resistance, we examined the expression of TGFβ-1 and Eps15 homology domain 1 (EHD1) in non-small cell lung cancer (NSCLC) and its association with tumor characteristics and survival of patients with NSCLC. Expression of TGFβ-1 and EHD1 was evaluated by immunohistochemistry in paraffin sections from 105 NSCLC patients. Overall survival (OS) was analyzed by Kaplan-Meier method, log-rank test, and multivariate Cox proportional hazard regression model. Positive immunostaining of TGFβ-1 and EHD1 was detected in 52.38 and 39.05 % of NSCLC samples, respectively. In non-adjuvant chemotherapy-treated group (P = 0.006) and epidermal growth factor receptor (EGFR) (+) group (P = 0.038), patients with TGFβ-1 expression had a longer OS. EHD1 negative expression predicted a longer OS (P = 0.003), especially in EGFR (+) (P = 0.006) and adjuvant chemotherapy-treated patients (P = 0.003). NSCLC patients with concurrent positive TGFβ-1 and negative EHD1 (combined markers) were significantly correlated with better OS (P = 0.001). American Joint Committee on Cancer (AJCC) status and combined markers were independent prognostic indicators for OS (HR (95 % CI) 1.576 (1.112-2.232), P = 0.011 and HR 0.349 (0.180-0.673), P = 0.002, respectively). We identified concordant TGFβ-1 positive and EHD1 negative as a strong favorable prognosis factor in NSCLC. Our results may help us to select and optimize strategies for individualized therapy.

The role of the inflammatory microenvironment in thyroid carcinogenesis

Immune responses against thyroid carcinomas have long been demonstrated and associations between inflammatory microenvironment and thyroid carcinomas repeatedly reported. This scenario has prompted scientists throughout the world to unveil how the inflammatory microenvironment is established in thyroid tumors and what is its influence on the outcome of patients with thyroid carcinoma. Many studies have reported the role of evasion from the immune system in tumor progression and reinforced the weakness of the innate immune response toward thyroid cancer spread in advanced stages. Translational studies have provided evidence that an increased density of tumor-associated macrophages in poorly differentiated thyroid carcinoma (DTC) is associated with an aggressive phenotype at diagnosis and decreased cancer-related survival, whereas well-DTC microenvironment enriched with macrophages is correlated with improved disease-free survival. It is possible that these different results are related to different microenvironments. Several studies have provided evidence that patients whose tumors are not infiltrated by lymphocytes present a high recurrence rate, suggesting that the presence of lymphocytes in the tumor microenvironment may favor the prognosis of patients with thyroid carcinoma. However, the effect of lymphocytes and other immune cells on patient outcome seems to result from complex interactions between the tumor and immune system, and the molecular pattern of cytokines and chemokines helps to explain the involvement of the immune system in thyroid tumor progression. The inflammatory microenvironment may help to characterize aggressive tumors and to identify patients who would benefit from a more invasive approach, probably sparing the vast majority of patients with an indolent disease from unnecessary procedures.

New experimental models of skin homeostasis and diseases

Homeostasis, whose regulation at the molecular level is still poorly understood, is intimately related to the functions of epidermal stem cells. Five research groups have been brought together to work on new in vitro and in vivo skin models through the SkinModel-CM program, under the auspices of the Spanish Autonomous Community of Madrid. This project aims to analyze the functions of DNA methyltransferase 1, endoglin, and podoplanin in epidermal stem cell activity, homeostasis, and skin cancer. These new models include 3-dimensional organotypic cultures, immunodeficient skin-humanized mice, and genetically modified mice. Another aim of the program is to use skin-humanized mice to model dermatoses such as Gorlin syndrome and xeroderma pigmentosum in order to optimize new protocols for photodynamic therapy.

The Treg/Th17 paradigm in lung cancer

Pathogenic mechanisms underlying the development of lung cancer are very complex and not yet entirely clarified. T lymphocytes and their immune-regulatory cytokines play a pivotal role in controlling tumor growth and metastasis. Following activation by unique cytokines, CD4+ T helper cells differentiate into Th1, Th2, Th17, and regulatory T cells (Tregs). Traditionally, research in lung cancer immunity has focused almost exclusively on Th1/Th2 cell balance. Recently, Th17 cells and Tregs represent an intriguing issue to be addressed in lung cancer pathogenesis. Tregs play an important role in the preservation of self-tolerance and modulation of overall immune responses against tumor cells. Th17 cells directly or via other proinflammatory cytokines modulate antitumor immune responses. Notably, there is a close relation between Tregs and Th17 cells. However, the possible interaction between these subsets in lung cancer remains to be elucidated. In this setting, targeting Treg/Th17 balance for therapeutic purposes may represent a useful tool for lung cancer treatment in the future. The purpose of this review is to discuss recent findings of the role of these novel populations in lung cancer immunity and to highlight the pleiotropic effects of these subsets on the development and regulation of lung cancer.

Transforming growth factors and receptor as potential modifiable pre-neoplastic biomarkers of risk for colorectal neoplasms

Increased colorectal epithelial cell proliferation is an early, common event in colorectal carcinogenesis. We conducted a pilot, colonoscopy-based case-control study (n = 49 cases, 154 controls) of incident, sporadic colorectal adenoma to investigate endogenous cell growth factors and receptor, as well as the balance of growth factors, as potential modifiable pre-neoplastic biomarkers of risk for colorectal neoplasms. We measured transforming growth factor alpha (TGFα), TGFβ(1), and TGFβ receptor II (TGFβRII) expression in normal-appearing mucosa from the rectum, sigmoid colon, and ascending colon using automated immunohistochemistry and quantitative image analysis. Diet and lifestyle were assessed via questionnaires. The mean ratio of rectal TGFα to TGFβ(1) expression and mean rectal TGFα expression were, respectively, 110% (P = 0.02) and 49% (P = 0.04) higher in cases than in controls, and associated with a more than two-fold (OR 2.42, 95% CI 0.85-6.87) and a 62% (OR 1.62, 95% CI 0.63-4.19) higher risk of colorectal adenoma. TGFβ(1) and TGFβRII expression were 6.7% (P = 0.75) and 7.2% (P = 0.49), respectively, lower in cases than in controls. The TGFα/TGFβ(1) expression ratio was 105% higher among smokers than among non-smokers (P = 0.03). These preliminary data suggest that the balance of TGFα and TGFβ(1) expression, and to a lesser extend TGFα alone, in the normal-appearing rectal mucosa may be directly associated with risk for incident, sporadic colorectal neoplasms, as well as with modifiable risk factors for colorectal neoplasms.

TGF-β1-ROS-ATM-CREB signaling axis in macrophage mediated migration of human breast cancer MCF7 cells

Macrophages in the tumor microenvironment play an important role in tumor cell survival. They influence the tumor cell to proliferate, invade into surrounding normal tissues and metastasize to local and distant sites. In this study, we evaluated the effect of conditioned medium from monocytes and macrophages on growth and migration of breast cancer cells. Macrophage conditioned medium (MϕCM) containing elevated levels of cytokines TNF-α, IL-1β and IL-6 had a differential effect on non-invasive (MCF7) and highly invasive (MDA-MB-231) breast cancer cell lines. MϕCM induced the secretion of TGF-β1 in MCF7 cells. This was associated with apoptosis in a fraction of cells and generation of reactive oxygen and nitrogen species (ROS and RNS) and DNA damage in the remaining cells. This, in turn, increased expression of cAMP response element binding protein (CREB) and vimentin resulting in migration of cells. These effects were inhibited by neutralization of TNF-α, IL-1β and IL-6, inhibition of ROS and RNS, DNA damage and siRNA mediated knockdown of ATM. In contrast, MDA-MB-231 cells which had higher basal levels of pCREB were not affected by MϕCM. In summary, we have found that pro-inflammatory cytokines secreted by macrophages induce TGF-β1 in tumor cells, which activate pCREB signaling, epithelial-mesenchymal-transition (EMT) responses and enhanced migration.

F-box protein complex FBXL19 regulates TGFβ1-induced E-cadherin down-regulation by mediating Rac3 ubiquitination and degradation

Background

Rac3 is a small GTPase multifunctional protein that regulates cell adhesion, migration, and differentiation. It has been considered as an oncogene in breast cancer; however, its role in esophageal cancer and the regulation of its stability have not been studied. F-box proteins are major subunits within the Skp1-Cullin-1-F-box (SCF) E3 ubiquitin ligases that recognize particular substrates for ubiquitination and proteasomal degradation. Recently, we have shown that SCF^FBXL19 targets Rac1 and RhoA, thus regulating Rac1 and RhoA ubiquitination and degradation. Here, we demonstrate the role of FBXL19 in the regulation of Rac3 site-specific ubiquitination and stability. Expression of TGFβ1 is associated with poor prognosis of esophageal cancer. TGFβ1 reduces tumor suppressor, E-cadherin, expression in various epithelial-derived cancers. Here we investigate the role of FBXL19-mediated Rac3 degradation in TGFβ1-induced E-cadherin down-regulation in esophageal cancer cells.

Methods

FBXL19-regulated endogenous and over-expressed Rac3 stability were determined by immunoblotting and co-immunoprecipitation. Esophageal cancer cells (OE19 and OE33) were used to investigate TGFβ1-induced E-cadherin down-regulation by Immunoblotting and Immunostaining.

Results

Overexpression of FBXL19 decreased endogenous and over-expressed Rac3 expression by interacting and polyubiquitinating Rac3, while down-regulation of FBXL19 suppressed Rac3 degradation. Lysine166 within Rac3 was identified as an ubiquitination acceptor site. The FBXL19 variant with truncation at the N-terminus resulted in an increase in Rac3 degradation; however, the FBXL19 variant with truncation at the C-terminus lost its ability to interact with Rac3 and ubiquitinate Rac3 protein. Further, we found that Rac3 plays a critical role in TGFβ1-induced E-cadherin down-regulation in esophageal cancer cells. Over-expression of FBXL19 attenuated TGFβ1-induced E-cadherin down-regulation and esophageal cancer cells elongation phenotype.

Conclusions

Collectively these data unveil that FBXL19 functions as an antagonist of Rac3 by regulating its stability and regulates the TGFβ1-induced E-cadherin down-regulation. This study will provide a new potential therapeutic strategy to regulate TGFβ1 signaling, thus suppressing esophageal tumorigenesis.

Mechanisms of tumor escape from immune system: role of mesenchymal stromal cells

Tumor microenvironment represents the site where the tumor tries to survive and escape from immune system-mediated recognition. Indeed, to proliferate tumor cells can divert the immune response inducing the generation of myeloid derived suppressor cells and regulatory T cells which can limit the efficiency of effector antitumor lymphocytes in eliminating neoplastic cells. Many components of the tumor microenvironment can serve as a double sword for the tumor and the host. Several types of fibroblast-like cells, which herein we define mesenchymal stromal cells (MSC), secrete extracellular matrix components and surrounding the tumor mass can limit the expansion of the tumor. On the other hand, MSC can interfere with the immune recognition of tumor cells producing immunoregulatory cytokines as transforming growth factor (TGF)ß, releasing soluble ligands of the activating receptors expressed on cytolytic effector cells as decoy molecules, affecting the correct interaction among lymphocytes and tumor cells. MSC can also serve as target for the same anti-tumor effector lymphocytes or simply impede the interaction between these lymphocytes and neoplastic cells. Thus, several evidences point out the role of MSC, both in epithelial solid tumors and hematological malignancies, in regulating tumor cell growth and immune response. Herein, we review these evidences and suggest that MSC can be a suitable target for a more efficient anti-tumor therapy.

Keep-ING balance: tumor suppression by epigenetic regulation

Cancer cells accumulate genetic and epigenetic changes that alter gene expression to drive tumorigenesis. Epigenetic silencing of tumor suppressor, cell cycle, differentiation and DNA repair genes contributes to neoplastic transformation. The ING (inhibitor of growth) proteins (ING1-ING5) have emerged as a versatile family of growth regulators, phospholipid effectors, histone mark sensors and core components of HDAC1/2 - and several HAT chromatin-modifying complexes. This review will describe the characteristic pathways by which ING family proteins differentially affect the Hallmarks of Cancer and highlight the various epigenetic mechanisms by which they regulate gene expression. Finally, we will discuss their potentials as biomarkers and therapeutic targets in epigenetic treatment strategies.

Modeling TGF-β in early stages of cancer tissue dynamics

Recent works have highlighted a double role for the Transforming Growth Factor (-): it inhibits cancer in healthy cells and potentiates tumor progression during late stage of tumorigenicity, respectively; therefore it has been termed the “Jekyll and Hyde” of cancer or, alternatively, an “excellent servant but a bad master”. It remains unclear how this molecule could have the two opposite behaviours. In this work, we propose a - multi scale mathematical model at molecular, cellular and tissue scales. The multi scalar behaviours of the - are described by three coupled models built up together which can approximatively be related to distinct microscopic, mesoscopic, and macroscopic scales, respectively. We first model the dynamics of - at the single-cell level by taking into account the intracellular and extracellular balance and the autocrine and paracrine behaviour of -. Then we use the average estimates of the - from the first model to understand its dynamics in a model of duct breast tissue. Although the cellular model and the tissue model describe phenomena at different time scales, their cumulative dynamics explain the changes in the role of - in the progression from healthy to pre-tumoral to cancer. We estimate various parameters by using available gene expression datasets. Despite the fact that our model does not describe an explicit tissue geometry, it provides quantitative inference on the stage and progression of breast cancer tissue invasion that could be compared with epidemiological data in literature. Finally in the last model, we investigated the invasion of breast cancer cells in the bone niches and the subsequent disregulation of bone remodeling processes. The bone model provides an effective description of the bone dynamics in healthy and early stages cancer conditions and offers an evolutionary ecological perspective of the dynamics of the competition between cancer and healthy cells.

Genome-wide comparison of the transcriptomes of highly enriched normal and chronic myeloid leukemia stem and progenitor cell populations

The persistence leukemia stem cells (LSCs) in chronic myeloid leukemia (CML) despite tyrosine kinase inhibition (TKI) may explain relapse after TKI withdrawal. Here we performed genome-wide transcriptome analysis of highly refined CML and normal stem and progenitor cell populations to identify novel targets for the eradication of CML LSCs using exon microarrays. We identified 97 genes that were differentially expressed in CML versus normal stem and progenitor cells. These included cell surface genes significantly upregulated in CML LSCs: DPP4 (CD26), IL2RA (CD25), PTPRD, CACNA1D, IL1RAP, SLC4A4, and KCNK5. Further analyses of the LSCs revealed dysregulation of normal cellular processes, evidenced by alternative splicing of genes in key cancer signaling pathways such as p53 signaling (e.g. PERP, CDKN1A), kinase binding (e.g. DUSP12, MARCKS), and cell proliferation (MYCN, TIMELESS); downregulation of pro-differentiation and TGF-β/BMP signaling pathways; upregulation of oxidative metabolism and DNA repair pathways; and activation of inflammatory cytokines, including CCL2, and multiple oncogenes (e.g., CCND1). These data represent an important resource for understanding the molecular changes in CML LSCs, which may be exploited to develop novel therapies for eradication these cells and achieve cure.

Loss of WISP2/CCN5 in estrogen-dependent MCF7 human breast cancer cells promotes a stem-like cell phenotype

It has been proposed that the epithelial-mesenchymal transition (EMT) in mammary epithelial cells and breast cancer cells generates stem cell features. WISP2 (Wnt-1-induced signaling protein-2) plays an important role in maintenance of the differentiated phenotype of estrogen receptor-positive breast cancer cells and loss of WISP2 is associated with EMT. We now report that loss of WISP2 in MCF7 breast cancer cells can also promote the emergence of a cancer stem-like cell phenotype characterized by high expression of CD44, increased aldehyde dehydrogenase activity and mammosphere formation. Higher levels of the stem cell markers Nanog and Oct3/4 were observed in those mammospheres. In addition we show that low-cell inoculums are capable of tumor formation in the mammary fat pad of immunodeficient mice. Gene expression analysis show an enrichment of markers linked to stem cell function such as SOX9 and IGFBP7 which is linked to TGF-β inducible, SMAD3-dependent transcription. Taken together, our data demonstrate that WISP2 loss promotes both EMT and the stem-like cell phenotype.

A genetic variant in microRNA target site of TGF-β signaling pathway increases the risk of colorectal cancer in a Chinese population

Evidence shows that single-nucleotide polymorphisms in microRNA (miRNA) target sites can create, destroy, or modify the miRNA/mRNA binding, therefore modulating gene expression and affecting cancer susceptibility. The transforming growth factor-β (TGF-β) signaling pathway plays a pivotal role in tumor initiation and progression. Intriguingly, recent advances of genome-wide association studies have identified multiple risk loci in this pathway to be associated with risk of colorectal cancer (CRC). To test the hypothesis that genetic variants in miRNA target sites in genes of the TGF-β signaling pathway may also be associated with CRC risk, we first systematically scanned the single-nucleotide polymorphisms (SNPs) in genes of TGF-β signaling pathway which potentially affect the miRNA/mRNA bindings. Through a series of filters, we narrowed down these candidates to four SNPs. Then, we conducted a case-control study with 600 CRC patients and 638 controls in Han Chinese population. We observed that compared with A carriers (AA + AG), the GG genotype of rs12997:ACVR1 is associated with a significantly higher risk of CRC (OR = 1.52, 95% confidence interval (95% CI) = 1.04-2.21, P = 0.031), particularly in nonsmokers with a higher OR of 1.63 (95% CI = 1.04-2.55, P = 0.032). Our study suggested that SNPs in miRNA target sites could contribute to the likelihood of CRC susceptibility and emphasized the important role of polymorphisms at miRNA-regulatory elements in carcinogenesis.

The effect of 5'-adenylic acid on hepatic proteome of mice radiated by 60Co γ-ray

Understanding the protection mechanism of 5′-AMP requires comprehensive knowledge of the proteins expressed during the period that the body is exposed to irradiation. Proteomics provides the tools for such analyses. Here, the experimental ICR mice were divided into three groups (normal group, model group and 5′-AMP + irradiation group). After different treatment, the hepatic total protein of each animal in three groups was separated by two-dimensional gel electrophoresis (2-DE). 2-DE analysis revealed fifty-eight protein spots were differentially expressed in comparison to three groups. From 58 protein spots, we selected nine spots to identify by MALDI-TOF-MS and received credible results. They were determined to be type I arginase, annexin A5, regucalcin, catalase, Tpm3 protein, Pdia4 protein, 14-3-3 protein epsilon, NAD-Malate dehydrogenase and heat shock protein 90. Considering the characteristic of these proteins, we proposed a possible protection pathway.

Low-dose anisomycin is sufficient to alter the bio-behaviors of Jurkat T cells

Anisomycin is a pyrrolidine antibiotic isolated from Streptomyces griseolus. It has been found that a quite low dose of anisomycin is sufficient to block proliferation of primary T lymphocytes. The focus of this study is to explore the possibility of anisomycin to treat human acute leukemia Jurkat T cells in vitro. The results indicated that the low dose of anisomycin could significantly inhibit the colony formation of Jurkat T cells and elevate the inhibition rate of Jurkat T cell growth along with its increasing concentrations. Jurkat T cell cycle was blocked into S-phase by anisomycin. Consistent with the increased proportion of sub-G1 phase, anisomycin promoted Jurkat T cell apoptosis. The CD69 and CD25 expression on the surface of Jurkat T cells was also down-regulated prominently along with the enhancing concentrations of anisomycin, followed by the decreased production of IL-4, IL-10, IL-17, TGF-β and IFN-γ, and the down-regulated expression of phosphorylated-ERK1/2. The results suggest that the suppressive effect of anisomycin on Jurkat T cell growth may be related to inhibiting TGF-β production and ERK1/2 activation, arresting the cell cycle at S-phase and promoting the apoptosis of Jurkat T cells.

The Roles of Epithelial-to-Mesenchymal Transition (EMT) and Mesenchymal-to-Epithelial Transition (MET) in Breast Cancer Bone Metastasis: Potential Targets for Prevention and Treatment

Many studies have revealed molecular connections between breast and bone. Genes, important in the control of bone remodeling, such as receptor activator of nuclear kappa (RANK), receptor activator of nuclear kappa ligand (RANKL), vitamin D, bone sialoprotein (BSP), osteopontin (OPN), and calcitonin, are expressed in breast cancer and lactating breast. Epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) effectors play critical roles during embryonic development, postnatal growth, and epithelial homeostasis, but also are involved in a number of pathological conditions, including wound repair, fibrosis, inflammation, as well as cancer progression and bone metastasis. Transforming growth factor β (TGFβ), insulin-like growth factor I & II (IGF I & II), platelet-derived growth factor (PDGF), parathyroid hormone-related protein (PTH(rP)), vascular endothelial growth factor (VEGF), epithelial growth factors II/I (ErbB/EGF), interleukin 6 (IL-6), IL-8, IL-11, IL-1, integrin αvβ3, matrix metalloproteinases (MMPs), catepsin K, hypoxia, notch, Wnt, bone morphogenetic proteins (BMP), and hedgehog signaling pathways are important EMT and MET effectors identified in the bone microenviroment facilitating bone metastasis formation. Recently, Runx2, an essential transcription factor in the regulation of mesenchymal cell differentiation into the osteoblast lineage and proper bone development, is also well-recognized for its expression in breast cancer cells promoting osteolytic bone metastasis. Understanding the precise mechanisms of EMT and MET in the pathogenesis of breast cancer bone metastasis can inform the direction of therapeutic intervention and possibly prevention.

Ltbp1L is focally induced in embryonic mammary mesenchyme, demarcates the ductal luminal lineage and is upregulated during involution

Introduction

Latent TGFβ binding proteins (LTBPs) govern TGFβ presentation and activation and are important for elastogenesis. Although TGFβ is well-known as a tumor suppressor and metastasis promoter, and LTBP1 is elevated in two distinct breast cancer metastasis signatures, LTBPs have not been studied in the normal mammary gland.

Methods

To address this we have examined Ltbp1 promoter activity throughout mammary development using an Ltbp1L-LacZ reporter as well as expression of both Ltbp1L and 1S mRNA and protein by qRT-PCR, immunofluorescence and flow cytometry.

Results

Our data show that Ltbp1L is transcribed coincident with lumen formation, providing a rare marker distinguishing ductal from alveolar luminal lineages. Ltbp1L and Ltbp1S are silent during lactation but robustly induced during involution, peaking at the stage when the remodeling process becomes irreversible. Ltbp1L is also induced within the embryonic mammary mesenchyme and maintained within nipple smooth muscle cells and myofibroblasts. Ltbp1 protein exclusively ensheaths ducts and side branches.

Conclusions

These data show Ltbp1 is transcriptionally regulated in a dynamic manner that is likely to impose significant spatial restriction on TGFβ bioavailability during mammary development. We hypothesize that Ltbp1 functions in a mechanosensory capacity to establish and maintain ductal luminal cell fate, support and detect ductal distension, trigger irreversible involution, and facilitate nipple sphincter function.

Gastric cancer-molecular and clinical dimensions

Gastric cancer imposes a considerable health burden around the globe despite its declining incidence. The disease is often diagnosed in advanced stages and is associated with a poor prognosis for patients. An in-depth understanding of the molecular underpinnings of gastric cancer has lagged behind many other cancers of similar incidence and morbidity, owing to our limited knowledge of germline susceptibility traits for risk and somatic drivers of progression (to identify novel therapeutic targets). A few germline (PLCE1) and somatic (ERBB2, ERBB3, PTEN, PI3K/AKT/mTOR, FGF, TP53, CDH1 and MET) alterations are emerging and some are being pursued clinically. Novel somatic gene targets (ARID1A, FAT4, MLL and KMT2C) have also been identified and are of interest. Variations in the therapeutic approaches dependent on geographical region are evident for localized gastric cancer-differences that are driven by preferences for the adjuvant strategies and the extent of surgery coupled with philosophical divides. However, greater uniformity in approach has been noted in the metastatic cancer setting, an incurable condition. Having realized only modest successes, momentum is building for carrying out more phase III comparative trials, with some using biomarker-based patient selection strategies. Overall, rapid progress in biotechnology is improving our molecular understanding and can help with new drug discovery. The future prospects are excellent for defining biomarker-based subsets of patients and application of specific therapeutics. However, many challenges remain to be tackled. Here, we review representative molecular and clinical dimensions of gastric cancer.

Tranilast enhances the anti-tumor effects of tamoxifen on human breast cancer cells in vitro

Background

Tamoxifen is the most widely used anti-estrogen for the treatment of breast cancer. Studies show that the combination therapy with other substances that helps the activity of tamoxifen. The objective of this study was to evaluate the effect of tamoxifen when used in combination with tranilast on human breast cancer cells.

Results

Two MCF-7 and MDA-MB-231 human breast cancer cell lines were treated with tamoxifen and/or tranilast. The cell viability and cytotoxicity was assessed using MTT and LDH assays; the apoptotic effects were examined by TUNEL assay, acridine orange/ethidium bromide staining and DNA laddering, also the expression levels of bax and bcl-2 genes were detected by real-time RT-PCR. The mRNA expression of TGF-β ligands and receptors examined using real-time RT-PCR and TGF-β1 protein secretion levels were also evaluated by ELISA assay. Inhibitory effect of these drugs on invasion and metastasis were tested by wound healing and matrigel invasion assay.

We found that combination of these drugs led to a marked increase in growth and proliferation inhibition compared to either agent alone. Furthermore, bax and bcl-2 affected by tamoxifen and/or tranilast and resulted in a significant increase in bax and decrease in bcl-2 mRNA expression. In addition, treatment with tamoxifen and/or tranilast resulted in significant decreased in TGF-β1, 2, 3, TGF-βRI and II mRNA and TGF-β1 protein levels while TGF-βRIII mRNA level was increased and invasion was also inhibited.

Conclusions

These findings indicate that tranilast, by synergistic effect, enhances the activity of tamoxifen and the TGF-β pathway is a target for this combination therapy, therefore; we propose that this combined treatment may be suitable selection in prevention of breast cancer.

Cytokine and cytokine receptor genes of the adaptive immune response are differentially associated with breast cancer risk in American women of African and European ancestry

Disparities in breast cancer biology are evident between American women of African ancestry (AA) and European ancestry (EA) and may be due, in part, to differences in immune function. To assess the potential role of constitutional host immunity on breast carcinogenesis, we tested associations between breast cancer risk and 47 single nucleotide polymorphisms (SNPs) in 26 cytokine-related genes of the adaptive immune system using 650 EA (n = 335 cases) and 864 AA (n = 458 cases) women from the Women's Circle of Health Study (WCHS). With additional participant accrual to the WCHS, promising SNPs from the initial analysis were evaluated in a larger sample size (1,307 EAs and 1,365 AAs). Multivariate logistic regression found SNPs in genes important for T helper type 1 (Th1) immunity (IFNGR2 rs1059293, IL15RA rs2296135, LTA rs1041981), Th2 immunity (IL4R rs1801275), and T regulatory cell-mediated immunosuppression (TGFB1 rs1800469) associated with breast cancer risk, mainly among AAs. The combined effect of these five SNPs was highly significant among AAs (P-trend = 0.0005). When stratified by estrogen receptor (ER) status, LTA rs1041981 was associated with ER-positive breast cancers among EAs and marginally among AAs. Only among AA women, IL15 rs10833 and IL15RA rs2296135 were associated with ER-positive tumors, and IL12RB1 rs375947, IL15 rs10833 and TGFB1 rs1800469 were associated with ER-negative tumors. Our study systematically identified genetic variants in the adaptive immune response pathway associated with breast cancer risk, which appears to differ by ancestry groups, menopausal status and ER status.