Epithelial-mesenchymal Transition In Breast Cancer Research Articles

PyMT-1099, a versatile murine cell model for EMT in breast cancer

An epithelial-mesenchymal transition (EMT) has been implicated in cancer metastasis, drug resistance, and in conferring stem cell-like traits to cancer cells. Most studies investigating EMT in cancer have either utilized immortalized or cancer cell lines that are already primed to undergo an EMT and do not adequately represent a fully differentiated epithelial state in the absence of an EMT induction. Hence, model systems are required which recapitulate all stages of EMT in cancer cells. Here, we report the derivation and characterization of epithelial PyMT-1099 cancer cells from the MMTV-PyMT mouse model of breast cancer. We demonstrate that PyMT-1099 cells undergo an EMT upon TGFβ treatment, while upon TGFβ withdrawal they go through a mesenchymal-epithelial transition (MET), as assessed by changes in cell morphology and marker expression and comparable to normal murine mammary gland NMuMG cells. However, in contrast to NMuMG cells, PyMT-1099 cells show an increase in cell migration and are highly tumorigenic and metastatic when transplanted into immunocompromised mice. Finally, we report cancer cell-specific changes in gene expression during EMT of PyMT-1099 cells not found in non-transformed NMuMG cells. Thus, PyMT-1099 cells are a versatile tool to study breast cancer-associated EMT and MET in vitro and in vivo.

Inhibitor of DNA Binding 2 Inhibits Epithelial-Mesenchymal Transition via Up-Regulation of Notch3 in Breast Cancer

Breast cancer is the second leading cause of cancer death in women worldwide. Incurable metastatic breast disease presents a major clinical challenge and is the main cause of breast cancer-related death. The epithelial-mesenchymal transition (EMT) is a critical early promoter of metastasis. In the present study, we identified a novel role for the inhibitor of DNA binding 2 (Id2), a member of the basic helix–loop–helix protein family, during the EMT of breast cancer. Expression of Id2 was positively correlated with Notch3 in breast cancer cells. Low expression of Id2 and Notch3 was associated with worse distant metastasis-free survival in breast cancer patients. The present study revealed that Id2 activated Notch3 expression by blocking E2A binding to an E-box motif in the Notch3 promoter. The Id2-mediated up-regulation of Notch3 expression at both the mRNA and protein levels resulted in an attenuated EMT, which was associated with reduced motility and matrix invasion of ER-positive and -negative human breast cancer cells and the emergence of E-cadherin expression and reduction in the mesenchymal marker vimentin in triple-negative breast cancer cells. In summary, our findings identified Id2 as a suppressor of the EMT and positive transcriptional regulator of Notch3 in breast cancer. Id2 and Notch3 may serve as novel prognostic markers in a subpopulation of ER-positive breast cancer patients.

LncRNA NKILA suppresses TGF-β-induced epithelial-mesenchymal transition by blocking NF-κB signaling in breast cancer.

TGF-β plays a central role in mediating epithelial-mesenchymal transition (EMT) by activating the Smad pathway. In addition, accumulating evidence suggests that TGF-β-induced EMT is NF-κB-dependent in various cancer types. However, it is largely unclear if NF-κB mediates TGF-β-induced EMT in breast cancer, and if this mediation occurs, the regulatory mechanisms are unknown. In our study, we found that TGF-β activates the NF-κB pathway. Inhibition of NF-κB signaling markedly abrogates TGF-β-induced EMT. By studying the regulatory mechanism of TGF-β-induced NF-κB signaling, we found that lncRNA NKILA was upregulated by TGF-β and was essential for the negative feedback regulation of the NF-κB pathway. Accordingly, overexpression of NKILA significantly reduced TGF-β-induced tumor metastasis in vivo. Consistent with the results from mice, the expression of NKILA was negatively correlated with EMT phenotypes in clinical breast cancer samples. Collectively, our study indicated that the NKILA-mediated negative feedback affects TGF-β-induced NF-κB activation and that NKILA may be a therapeutic molecule in breast cancer metastasis via inhibition of EMT.

MiR‑185‑5p inhibits F‑actin polymerization and reverses epithelial mesenchymal transition of human breast cancer cells by modulating RAGE.

In our previous study, advanced glycosylation end-product specific receptor (RAGE) was observed to bind to S100A8/A9 and cause epithelial mesenchymal transition (EMT). The results from target gene prediction revealed that microRNA (miR)-185-5p had a RAGE binding site. However, the function of miR-185-5p in the invasion and migration of breast cancer remains ambiguous. In the present study, the expression of miR-185-5p was examined in breast cancer tissues and cells. Clinical features revealed a negative correlation between miR-185-5p and tumor size, as well as in tumor differentiation and lymph node metastasis in breast cancer. In addition, miR-185-5p was negatively associated with RAGE, and this miRNA reversed the EMT of breast cancer by modulating RAGE in vitro. In addition, miR-185-5p inhibited the S100A8/A9-induced EMT of breast cancer cells by the nuclear factor-κB/Snail signaling pathway. Notably, miR-185-5p upregulation inhibited the F-actin polymerization induced by S100A8/A9 in breast cancer. Furthermore, overexpression of miR-185-5p and reduction of RAGE inhibited lung metastasis node in vivo. Thus, miR-185-5p represents a potential therapeutic target in breast cancer by modulating RAGE.

Crosstalk between Notch, HIF-1α and GPER in Breast Cancer EMT.

The Notch signaling pathway acts in both physiological and pathological conditions, including embryonic development and tumorigenesis. In cancer progression, diverse mechanisms are involved in Notch-mediated biological responses, including angiogenesis and epithelial-mesenchymal-transition (EMT). During EMT, the activation of cellular programs facilitated by transcriptional repressors results in epithelial cells losing their differentiated features, like cell–cell adhesion and apical–basal polarity, whereas they gain motility. As it concerns cancer epithelial cells, EMT may be consequent to the evolution of genetic/epigenetic instability, or triggered by factors that can act within the tumor microenvironment. Following a description of the Notch signaling pathway and its major regulatory nodes, we focus on studies that have given insights into the functional interaction between Notch signaling and either hypoxia or estrogen in breast cancer cells, with a particular focus on EMT. Furthermore, we describe the role of hypoxia signaling in breast cancer cells and discuss recent evidence regarding a functional interaction between HIF-1α and GPER in both breast cancer cells and cancer-associated fibroblasts (CAFs). On the basis of these studies, we propose that a functional network between HIF-1α, GPER and Notch may integrate tumor microenvironmental cues to induce robust EMT in cancer cells. Further investigations are required in order to better understand how hypoxia and estrogen signaling may converge on Notch-mediated EMT within the context of the stroma and tumor cells interaction. However, the data discussed here may anticipate the potential benefits of further pharmacological strategies targeting breast cancer progression.

SREBP1, targeted by miR-18a-5p, modulates epithelial-mesenchymal transition in breast cancer via forming a co-repressor complex with Snail and HDAC1/2

The progression of localized breast cancer to distant metastasis results in a poor prognosis and a high mortality rate. In this study, the contributions of miRNAs to tumor progression and the regulatory mechanisms leading to their expression alterations were investigated. Using highly lung-metastatic sub-lines from parental breast cancer cells, miRNA expression profiling revealed that the miR-17-92 cluster is significantly downregulated and the miR-18a-5p is the most evidently decreased. Ectopic expression and inhibition of miR-18a-5p demonstrated its capacity in suppressing migration and invasion of breast cancer cells. Further research identified sterol regulatory element binding transcription protein 1 (SREBP1), the master transcription factor that controls lipid metabolism, as a candidate target of miR-18a-5p. SREBP1 is overexpressed and strongly associated with worse clinical outcomes in breast cancer. Functionally SREBP1 promotes growth and metastasis of breast cancer both in vitro and in vivo. To unravel the underlying mechanism of SREBP1-mediated metastasis, mRNA profiling and subsequent gene set enrichment analyses (GSEA) were performed and SREBP1 was demonstrated to be significantly associated with epithelial-mesenchymal transition (EMT). Furthermore, SREBP1-mediated repression of E-cadherin was found to be deacetylation dependent and was augmented by recruiting Snail/HDAC1/2 repressor complex. In the light of these data, we propose that reduced expression of miR-18a-5p and concomitant overexpression of SREBP1 lead to induction of EMT states that in turn, promote breast cancer progression and metastasis. Taken together, our study reveals the crucial role of miR-18a-5p and SREBP1 in the EMT and metastasis, thus providing promising drug targets for tailored therapy in the advanced breast cancer setting.

PO-181 Predicting homing ability of hepatocellular carcinoma cells by using a lab-on-a-chip system

IntroductionThe core subunit of the COMPASS-like complex, WD Repeat Domain 5 (WDR5) has a prominent role in cell self-renewal, reprogramming and Epithelial-to-Mesenchymal transition (EMT) in different tumour types. We have identified WDR5 as an epigenetic target in in vivo and in vitro shRNA screenings performed in MCF10DCIS.com (from now MCF10DCIS) breast cancer (BC) cells. Here, we show that WDR5 can regulate metastasis dissemination in BC by stimulating TGFB-induced EMT.Material and methodsMCF10DCIS and MDAMB231 cells and six metastatic PDXs were used for in vivo and in vitro studies. Cells were transduced to silence WDR5 (shWDR5) or a neutral control (shLuc). Transcriptomic profiles were evaluated by RNA-seq in shLuc and shWDR5 PDXs and MCF10DCIS cells. Differentially expressed genes (DEGs) were identified using Log2FC>|0.6| and FDR<0.05. Chromatin Immunoprecipitation was performed to identify H3K4me3 binding in shLuc and shWDR5 MCF10DCIS cells. Peak calling was performed using MACS2.0 and peaks distribution was analysed within ±2.5 kbp from Transcription Start Sites (TSS) region of target genes. TGFB induction was obtained by 5 ng/ml TGFB-administration for 2 days in MCF10DCIS cells. Statistical analysis was performed by applying a Student t test for in vivo and in vitro experiments.Results and discussionsWDR5 interference significantly inhibited tumour growth and in vitro migration of PDXs and MCF10DCIS cells and reduced metastatic burden of MDAMB231 cells in vivo. These data suggested that WDR5 may be involved in cell motility, promoting invasiveness and metastasis. Gene Ontology performed on DEGs highlighted an enrichment of functions related to EMT and TGFB signalling. Indeed, protein and mRNA levels of a series of gene implicated in EMT (e.g. SNAI1, TWIST1, CDH2, SNAI2, ZEB1) were strongly reduced in shWDR5 PDXs and MCF10DCIS cells, thus suggesting a regulatory role of WDR5 in EMT. H3K4me3 levels were globally affected and concordantly reduced at TSS level of SNAI1 and TWIST1 genes in shWDR5 MCF10DCIS cells, confirming that WDR5 can transcriptionally regulate EMT in BC. Moreover, the induction of EMT by TGFB treatment can be abrogated in WDR5-deficient cells, suggesting that the EMT induced by TGFB is WDR5-dependent.ConclusionOur evidences support a model in which WDR5 is responsible for mediating the epithelial-to-mesenchymal transition and metastasis dissemination in BC. WDR5 is essential for TGFB response and its inhibition may be a successful approach to prevent progression of metastatic BC.

PMLIV overexpression promotes TGF-β-associated epithelial-mesenchymal transition and migration in MCF-7 cancer cells.

The epithelial-mesenchymal transition (EMT) is a key event associated with metastasis and dissemination in breast tumor pathogenesis. Promyelocytic leukemia (PML) gene produces several isoforms due to alternative splicing; however, the biological function of each specific isoform has yet to be identified. In this study, we report a previously unknown role for PMLIV, the most intensely studied nuclear isoform, in transforming growth factor-β (TGF-β) signaling-associated EMT and migration in breast cancer. This study demonstrates that PMLIV overexpression promotes a more aggressive mesenchymal phenotype and increases the migration of MCF-7 cancer cells. This event is associated with activation of the TGF-β canonical signaling pathway through the induction of Smad2/3 phosphorylation and the translocation of phospho-Smad2/3 to the nucleus. In this study, we report a previously unknown role for PMLIV in TGF-β signaling-induced regulation of breast cancer-associated EMT and migration. Targeting this pathway may be therapeutically beneficial.

Trop2 is a potential biomarker for the promotion of EMT in human breast cancer.

Trop2 is considered to have an important function in tumor metastasis and the promotion of epithelial‑mesenchymal transition (EMT). E‑cadherin is a crucial factor in intercellular adhesion and EMT transformation. In the present study, we detected the expression of Trop2 and E‑cadherin in breast cancer (BC) to better define their prognostic value. The mRNA expression levels of these two genes in 20cases of fresh BC tissues were detected by quantitative real‑time polymerase chain reaction (qRT‑PCR). We also detected the expression levels of these two genes by immunohistochemistry (IHC) in 312BC tissues, and the correlations between the expression of these two genes and the clinicopathological characteristics in BC patients were analyzed. The mRNA and protein expression levels of the two genes in BC cell lines were studied by qRT‑PCR and western blotting. The results indicated that Trop2+/E‑cadherin‑ was expressed in BC tissues more than that in the matched adjacent tissues. The protein expression results obtained via IHC were similar to the mRNA expression results. Trop2+/E‑cadherin‑ that was expressed in BC was associated with lymph node status, metastasis, tumor‑node‑metastasis (TNM) stage, and ER‑/PR‑/HER2‑ expression. BC patients that expressed Trop2+/E‑cadherin‑ had poor overall survival rates. The results of Trop2 and E‑cadherin expression levels obtained in the BC cell lines were the same as those obtained in the BC tissues. Overall, Trop2 has a potential role in the promotion of EMT in BC and it could be considered as a therapeutic target in the future.

MicroRNA-708-3p mediates metastasis and chemoresistance through inhibition of epithelial-to-mesenchymal transition in breast cancer.

Metastasis and chemoresistance remain major challenges in the clinical treatment of breast cancer. Recent studies show that dysregulated microRNAs (miRNAs) play an important role in metastasis and chemoresistance development in breast cancer. Herein, we identified downregulated expression of miR‐708‐3p in breast cancers. In particular, miR‐708‐3p expression was significantly decreased in specimens from breast cancer patients with metastasis compared to that in specimens from patients with no metastasis. Consistent with clinical data, our in vitro data show that miR‐708‐3p was more significantly decreased in invasive breast cancer cell lines. In addition, our data show that inhibition of miR‐708‐3p significantly stimulated breast cancer cell metastasis and induced chemoresistance both in vitro and in vivo. In contrast, overexpression of miR‐708‐3p dramatically inhibited breast cancer cell metastasis and enhanced the sensitivity of breast cancer cells to chemotherapy both in vitro and in vivo. Furthermore, we identified that miR‐708‐3p inhibits breast cancer cell epithelial‐to‐mesenchymal transition (EMT) by directly targeting EMT activators, including ZEB1, CDH2 and vimentin. Taken together, our findings suggest that miR‐708‐3p acts as a cancer suppressor miRNA and carries out its anticancer function by inhibiting EMT in breast cancer. In addition, our findings suggest that restoration of miR‐708‐3p may be a novel strategy for inhibiting breast cancer metastasis and overcoming the chemoresistance of breast cancer cells.

Macrophage inflammatory factors promote epithelial-mesenchymal transition in breast cancer.

The majority of breast cancers (90–95%) arise due to mediators distinct from inherited genetic mutations. One major mediator of breast cancer involves chronic inflammation. M1 macrophages are an integral component of chronic inflammation and the breast cancer tumor microenvironment (TME). Previous studies have demonstrated that up to 50% of the breast tumor comprise of tumor-associated macrophages (TAMs) and increased TAM infiltration has been associated with poor patient prognosis. Furthermore, breast cancer associated deaths are predominantly attributed to invasive cancers and metastasis with epithelial-mesenchymal transition (EMT) being implicated. In this study, we investigated the effects of cellular crosstalk between TAMs and breast cancer using an in vitro model system. M1 polarized THP-1 macrophage conditioned media (CM) was generated and used to evaluate cellular and functional changes of breast cancer lines T47D and MCF-7. We observed that T47D and MCF-7 exhibited a partial EMT phenotype in the presence of activated THP-1 CM. Additionally, MCF-7 displayed a significant increase in migratory and invasive properties. We conclude that M1 secretory factors can promote a partial EMT of epithelial-like breast cancer cells. The targeting of M1 macrophages or their secretory components may inhibit EMT and limit the invasive potential of breast cancer.

TRPS1 Suppresses Breast Cancer Epithelial-mesenchymal Transition Program as a Negative Regulator of SUZ12

Breast cancer (BC) is among the most common malignant diseases and metastasis is the handcuff of treatment. Cancer metastasis is a multistep process associated with the epithelial-mesenchymal transition (EMT) program. Several studies have demonstrated that transcriptional repressor GATA binding 1 (TRPS1) played important roles in development and progression of primary BC. In this study we sought to identify the mechanisms responsible for this function of TRPS1 in the continuum of the metastatic cascade. Here we described that TRPS1 was significantly associated with BC metastasis using public assessable datasets. Clinically, loss of TRPS1 expression in BC was related to higher histological grade. In vitro functional study and bioinformatics analysis revealed that TRPS1 inhibited cell migration and EMT in BC. Importantly, we identified SUZ12 as a novel target of TRPS1 related to EMT program. ChIP assay demonstrated TRPS1 directly inhibited SUZ12 transcription by binding to the SUZ12 promoter. Loss of TRPS1 resulted in increased SUZ12 binding and H3K27 tri-methylation at the CDH1 promoter and repression of E-cadherin. In all, our data indicated that TRPS1 maintained the expression of E-cadherin by inhibiting SUZ12, which might provide novel insight into how loss of TRPS1 contributed to BC progression.

U-box ubiquitin ligase PPIL2 suppresses breast cancer invasion and metastasis by altering cell morphology and promoting SNAI1 ubiquitination and degradation

Metastasis is the leading cause of breast cancer fatalities. To develop new therapeutic strategies, the mechanisms underlying breast cancer invasion and metastasis need to be further investigated. Peptidylprolyl isomerase (cyclophilin)-like 2 (PPIL2) is a U-box-type E3 ubiquitin ligase belonging to the cyclophilin family. Proteins within this family are the major cytosolic binding proteins of the immunosuppressant drug cyclosporine A (CsA). Although PPIL2 has been reported to potentially be involved in cell migration, its role in breast cancer is still unclear. Herein, we demonstrate that PPIL2 suppressed metastasis in a breast cancer model by altering cell morphology and suppressing the epithelial–mesenchymal transition (EMT) process. Moreover, elevated PPIL2 inhibited EMT and breast cancer invasion by interacting with the classical EMT transcription factor, SNAI1, to enhance its ubiquitin-dependent degradation. Furthermore, PPIL2 protein level and stability was upregulated after CsA treatment, indicating that PPIL2 might be involved in CsA-mediated repression of EMT in breast cancer. Analysis of tissue samples taken from breast cancer patients showed a significant correlation between the expression of PPIL2 and the degree of cancer invasion and metastasis. In summary, these results would shed light on a potential clinical use of CsA in breast cancer patients.

PTBP3-Mediated Regulation of ZEB1 mRNA Stability Promotes Epithelial-Mesenchymal Transition in Breast Cancer.

The RNA polypyrimidine tract-binding protein PTBP3 is a little studied paralog of PTBP1, which has oncogenic properties. In this study, we demonstrate that PTBP3 induces epithelial-mesenchymal transition (EMT) in breast tumor cells and promotes their invasive growth and metastasis. Elevated expression of PTBP3 associated significantly with lymph node metastasis, advanced histology grade, TNM stage, and poor 5-year overall survival of patients. In human mammary epithelial cells, PTBP3 overexpression was sufficient to induce EMT and to enhance cell migration, invasion, and cancer stem-like cell properties. PTBP3 regulated expression of the EMT regulatory transcription factor ZEB1 by binding the 3'UTR of its mRNA, thereby preventing its degradation. Conversely, ZEB1 ablation blocked the ability of PTBP3 to induce EMT. Overall, our findings define PTBP3 as a regulator of EMT that acts by governing expression of ZEB1, and they establish an oncogenic function of PTBP3, suggesting its candidacy as a theranostic target.Significance: These findings define PTBP3 as a regulator of EMT that acts by governing expression of ZEB1, and they establish an oncogenic function of PTBP3, suggesting its candidacy as a theranostic target. Cancer Res; 78(2); 387-98. ©2017 AACR.

FGF18 Enhances Migration and the Epithelial-Mesenchymal Transition in Breast Cancer by Regulating Akt/GSK3β/Β-Catenin Signaling

Background/Aims: Fibroblast growth factors (FGFs) and their high-affinity receptors contribute to autocrine and paracrine growth stimulation in several human malignant tumors, including breast cancer. However, the mechanisms underlying the carcinogenic actions of FGF18 remain unclear. Methods: The transcription level of FGF18 under the hypoxic condition was detected with quantitative PCR (qPCR). A wound-healing assay was performed to assess the role of FGF18 in cell migration. A clonogenicity assay was used to determine whether FGF18 silencing affected cell clonogenicity. Western blotting was performed to investigate Akt/GSK3β/β-catenin pathway protein expression. Binding of β-catenin to the target gene promoter was determined by chromatin immunoprecipitation (ChIP) assays. Results: FGF18 promoted the epithelial-mesenchymal transition (EMT) and migration in breast cancer cells through activation of the Akt/GSK3β/β-catenin pathway. FGF18 increased Akt-Ser473 and -Thr308 phosphorylation, as well as that of GSK3β-Ser9. FGF18 also enhanced the transcription of proliferation-related genes (CDK2, CCND2, Ki67), metastasis-related genes (TGF-β, MMP-2, MMP-9), and EMT markers (Snail-1, Snail-2, N-cadherin, vimentin, TIMP1). β-catenin bound to the target gene promoter on the ChIP assay. Conclusion: FGF18 contributes to the migration and EMT of breast cancer cells following activation of the Akt/GSK3β/β-catenin pathway. FGF18 expression may be a potential prognostic therapeutic marker for breast cancer.

Long non-coding RNAs AC026904.1 and UCA1: a "one-two punch" for TGF-β-induced SNAI2 activation and epithelial-mesenchymal transition in breast cancer.

Transforming growth factor-β (TGF-β) has received much attention as a major inducer of epithelial-mesenchymal transition (EMT) during cancer progression, mainly by activating a set of pleiotropic transcription factors including SNAI2/Slug. However, the involvement of long non-coding RNAs (lncRNAs) in TGF-β-induced Slug activation and EMT remains largely unknown.Methods: In this study, we used microarray analysis to compare lncRNA expression profiles between TGF-β treated and untreated breast cancer cells. Then, the clinical significance of lncRNAs in breast cancer was investigated by qPCR and Kaplan-Meier survival analysis. The molecular mechanisms and EMT-promoting effects in vitro were analyzed by confocal laser microscopy, Western blotting, chromosome conformation capture (3C), chromatin isolation by RNA purification (ChIRP), ChIP, luciferase reporter assay and transwell migration assay. Lastly, the pro-metastatic effects in vivo were evaluated by bioluminescent imaging and hematoxylin and eosin (H&E) staining.Results: We observed that TGF-β induced genome-wide changes in lncRNA levels in breast cancer cells, among which AC026904.1 and UCA1 were highly expressed in metastatic breast cancer and closely associated with poor prognosis. Mechanistic study revealed that AC026904.1 and UCA1 were upregulated by non-canonical and canonical TGF-β pathways, respectively. Further analysis showed that AC026904.1 functions as an enhancer RNA in the nucleus, whereas UCA1 exerts a competitive endogenous RNA (ceRNA) activity in the cytoplasm. In addition, the biological functions of these two lncRNAs converged on the activation and maintenance of Slug, constituting a one-two punch in promoting EMT and tumor metastasis.Conclusion: These findings uncover for the first time that AC026904.1 and UCA1 could cooperatively upregulate Slug expression at both transcriptional and post-transcriptional levels, exerting critical roles in TGF-β-induced EMT. The present work provides new evidence that lncRNAs function as key regulators of EMT and hold great promise to be used as novel biomarkers and therapeutic targets for metastatic breast cancer.

FOXM 1 Expression in Breast Carcinoma and Correlation with Histopathological Staging and Grading

FOXM1 (Forkhead box protein M1) promoted EMT (Epithelial-to-mesenchymal transition) in breast cancer by binding and activation of the promoter of SLUG gene. that FOXM1 promotes breast cancer metastases by activation of the TGF-β pathway with through interaction SMAD3 (this prevented E3 ubiquitin-protein ligase transcriptional intermediary factor 1 γ [TIF1 γ] binding to SMAD3 and protected SMAD4 from ubiquitination) that leads to stabilization of the SMAD3/SMAD4 complex. The study samples included seventy four formalin-fixed, paraffin embedded tissue blocks which have been diagnosed as forty four cases of breast carcinoma and their lymph nodes. In the present study from 74 total cases, 46 cases (62.6%) were showing FOXM1 marker positive while 28 cases (37.8%) were showing negative immunohistochemistry for FOXM1 marker. Sub classification of malignant cases, 16 malignant breast cancer cases (36.4%) showed no FOXM1 expression, while 12 malignant cases (27.3%) were strongly positive for FOXM1 expression. There is significant correlation between breast carcinoma grade, stage and FOXM1 expression.

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

Lactate-activated macrophages induced aerobic glycolysis and epithelial-mesenchymal transition in breast cancer by regulation of CCL5-CCR5 axis: a positive metabolic feedback loop.

Aberrant energy metabolism is critical for cancer progression. Tumor-associated macrophages (TAMs) can stimulate tumor angiogenesis and enhance cancer metastasis; however, the metabolic interaction between cancer cells and macrophages characterized by lactate shuttles remains unclear. Here, we showed that lactate activated human macrophages to a TAM-like phenotype and stimulated the secretion of CCL5 by activation of Notch signaling in macrophages. Reciprocally, CCL5 increased cell migration, induced cancer cell EMT, and promoted aerobic glycolysis in breast cancer cells, suggesting a positive metabolic feedback loop in the co-culture system. Inhibition of CCR5, the cognate receptor of CCL5, or neutralization of CCL5, broke the metabolic loop and decreased cancer cell migration and EMT. Inhibition of aerobic glycolysis significantly reduced breast cancer cell EMT, indicated that aerobic glycolysis was necessary for the invasive phenotype of cancer cells. We further showed that TGF-β signaling regulated the expression of CCR5 in the co-culture system, and CCL5 induced glycolysis by mediation of AMPK signaling. The expression of CCL5-CCR5 axis was highly associated with macrophage infiltration, TGF-β and p-AMPK in clinical samples. CCL5-CCR5 axis promoted breast cancer metastasis in vivo. Our findings suggested a pivotal role of CCL5-CCR5 axis in the metabolic communication between cancer cells and macrophages.

Protein tyrosine phosphatase receptor-type δ acts as a negative regulator suppressing breast cancer

Protein tyrosine phosphatase receptor-type δ (PTPRD) is frequently inactivated in human cancers. This study investigated the role of PTPRD in the regulation of stemness, epithelial-mesenchymal transition (EMT), and migration and invasion in breast cancer cells. In vitro, PTPRD silencing using siRNA enhanced the stem cell-like properties of breast cancer cells, including their mammosphere- and holoclone-forming abilities, and it promoted tumorigenicity in vivo. PTPRD knockdown also increased the CD44+/CD24− breast cancer stem cell (BCSC) population and the expression of the stem cell markers ALDH1 and OCT4. It also promoted migration and invasion by breast cancer cell, EMT, and activation of signal transducer and activator of transcription 3 (STAT3). BCSCs expressed low levels of PTPRD, displayed mesenchymal phenotypes, and were more sensitive to IL-6-mediated STAT3 activation than non-BCSCs. PTPRD expression was upregulated by IL-6 in breast cancer cells, thereby establishing a negative feedback circuit by which IL-6 induced canonical STAT3 phosphorylation and transiently upregulated PTPRD, which in turn dephosphorylated STAT3 and prevented downstream signaling via the IL-6/STAT3 cascade. These data suggest that therapies aimed at restoring or enhancing PTPRD expression may be effective in controlling breast cancer progression and metastasis.