EMT promoting transcription factors as prognostic markers in human breast cancer

E-cadherin staining in the diagnosis of lobular versus ductal neoplasms of the breast: the emperor has no clothes

Categorizing breast neoplasia as ductal or lobular is a daily exercise that relies on a combination of histologic and immunohistochemical tools. The historically robust link between loss of the E-cadherin molecule and lobular neoplasia has rendered staining for E-cadherin by immunohistochemistry a staple of this diagnostic process. Unfortunately, discordances between E-cadherin expression and histomorphology, and variations in E-cadherin staining patterns and intensities abound in clinical practice, but are often neglected in favour of a binary interpretation of the E-cadherin result. In this article, we highlight the complexities of E-cadherin expression through a review of the E-cadherin protein and its associated gene (CDH1), the mechanisms leading to aberrant/absent E-cadherin expression, and the implications of these factors on the reliability of the E-cadherin immunohistochemical stain in the classification of ductal versus lobular mammary neoplasia.

Tumor necrosis factor receptor-associated factor 5 enhances perianal fistulizing Crohn's disease through epithelial-mesenchymal transition

Objective

Crohn's disease (CD) is a chronic inflammatory condition of the bowel that remarkably impairs a patient's quality of life and often has a poor prognosis. Perianal fistulizing CD (PFCD) is one of the most common parenteral symptoms of CD and a huge challenge for the management of this illness. This study aimed to elucidate the molecular mechanisms underlying PFCD and identify potential biomarkers to advance our understanding and management of this condition.

Material and Methods

Transcriptome sequencing was performed using the control and PFCD groups to investigate the mechanisms of PFCD development. The expression of tumor necrosis factor receptor-associated factor 5 (TRAF5), nuclear factor-kappa B (NF-κB), and interleukin 13 (IL-13) messenger ribonucleic acid (mRNAs) was detected by quantitative polymerase chain reaction (qPCR). Pathological morphology was observed using hematoxylin and eosin staining. The expression of TRAF5, Epithelial Cadherin (E-cadherin), Snail family transcriptional repressor 1 (SNAIL1), and vimentin protein was detected by immunohistochemistry. Following the knockdown of TRAF5 in human tumor-29 (HT-29) cells, the effects on cell proliferation and migration were assessed using the cell counting kit-8 and Transwell assays. The expression levels of crucial markers were analyzed by qPCR, Western blot, and immunohistochemistry.

Results

Transcriptomic sequencing revealed a significant upregulation of TRAF5 in the PFCD group, accompanied by elevated mRNA levels of NF-κB and IL-13 compared with those in the control group. In addition, the PFCD group exhibited increased expression of TRAF5, SNAIL, and vimentin and marked reduction in E-cadherin levels, indicating that PFCD may facilitate epithelial-mesenchymal transition (EMT). Knocking down TRAF5 in HT-29 cells reduced cell proliferation and migration; inhibited NF-κB and IL-13 mRNAs, SNAIL1, and vimentin levels; and promoted E-cadherin levels.

Conclusions

The development of PFCD was associated with EMT, and TRAF5 was a key gene of PFCD. Knocking down TRAF5 alleviated the EMT promotion of PFCD, indicating that TRAF5 drove the development of PFCD through EMT.

Structurally diverse design and synthesis of novel 2-phenylindole amide derivatives with anti-canine breast cancer activity

Breast cancer stands as the cancer with the highest incidence and mortality rates among women globally, in which triple-negative breast cancer has been ranked as the most difficult one. Bazedoxifene (BZA), a third-generation selective estrogen receptor modulator (SERM), has been exhibited notable inhibitory effect on both hormone-dependent breast cancer cells and triple-negative breast cancer cells, but showing very low in vivo effeacy. In order to obtain more effective antitumor derivatives than BZA, we have employed a structurally diverse design and synthesis of 57 novel 2-phenylindole amides for detecting their cytotoxities against triple-negative mammary cancer cell line, CMT-7364. Among them, 21 compounds demonstrated significant inhibitory activity against CMT-7364 cells (IC50 < 20 μM). Notably, compound 49 stood out, displaying both similar tumor cell inhibition (20 % reduce in IC50 value) and higher selectivity (4.6 times higher in SI value), compared to Bazedoxifene. Additionally, compound 49 exhibited desirable antitumor effects in a CMT-7364 cell-derived mouse in vivo model, achieving the best inhibition rate of 43.1 % and establishing strong molecular bonding with GP130. Our findings are also supported by comprehensive SAR and 3D-QSAR analyses. Furthermore, the best potent compound 49 was determined to block the cell cycle of canine breast cancer cells in the G0G1 phase in a time-dependent manner, by inducing apoptosis and autophagy. In conclusion, this work presents a valuable lead compound as a potential GP130 inhibitor against triple-negative breast cancer cell lines, laying the foundation for further antitumor drug development.

Tumor biomarkers for diagnosis, prognosis and targeted therapy

Tumor biomarkers, the substances which are produced by tumors or the body's responses to tumors during tumorigenesis and progression, have been demonstrated to possess critical and encouraging value in screening and early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, continuous progress has been made in exploring and discovering novel, sensitive, specific, and accurate tumor biomarkers, which has significantly promoted personalized medicine and improved the outcomes of cancer patients, especially advances in molecular biology technologies developed for the detection of tumor biomarkers. Herein, we summarize the discovery and development of tumor biomarkers, including the history of tumor biomarkers, the conventional and innovative technologies used for biomarker discovery and detection, the classification of tumor biomarkers based on tissue origins, and the application of tumor biomarkers in clinical cancer management. In particular, we highlight the recent advancements in biomarker-based anticancer-targeted therapies which are emerging as breakthroughs and promising cancer therapeutic strategies. We also discuss limitations and challenges that need to be addressed and provide insights and perspectives to turn challenges into opportunities in this field. Collectively, the discovery and application of multiple tumor biomarkers emphasized in this review may provide guidance on improved precision medicine, broaden horizons in future research directions, and expedite the clinical classification of cancer patients according to their molecular biomarkers rather than organs of origin.

Single-cell tracking as a tool for studying EMT-phenotypes

This article demonstrates that label-free single-cell video tracking is a useful approach for in vitro studies of Epithelial-Mesenchymal Transition (EMT). EMT is a highly heterogeneous process, involved in wound healing, embryogenesis and cancer. The process promotes metastasis, and increased understanding can aid development of novel therapeutic strategies. The role of EMT-associated biomarkers depends on biological context, making it challenging to compare and interpret data from different studies. We demonstrate single-cell video tracking for comprehensive phenotype analysis. In this study we performed single-cell video tracking on 72-h long recordings. We quantified several behaviours at a single-cell level during induced EMT in MDA-MB-468 cells. This revealed notable variations in migration speed, with different dose-response patterns and varying distributions of speed. By registering cell morphologies during the recording, we determined preferred paths of morphological transitions. We also found a clear association between migration speed and cell morphology. We found elevated rates of cell death, diminished proliferation, and an increase in mitotic failures followed by re-fusion of sister-cells. The method allows tracking of phenotypes in cell lineages, which can be particularly useful in epigenetic studies. Sister-cells were found to have significant similarities in their speeds and morphologies, illustrating the heritability of these traits.

USP30 promotes the progression of breast cancer by stabilising Snail

Breast cancer (BC) is the most prevalent tumour in women worldwide. USP30 is a deubiquitinase that has been previously reported to promote tumour progression and lipid synthesis in hepatocellular carcinoma. However, the role of USP30 in breast cancer remains unclear. Therefore, we investigated its biological action and corresponding mechanisms in vitro and in vivo. In our study, we found that USP30 was highly expressed in breast cancer samples and correlated with a poor patient prognosis. Knockdown of USP30 significantly suppressed the proliferation, invasion and migration abilities of BC cells in vitro and tumour growth in vivo, whereas overexpression of USP30 exhibited the opposite effect. Mechanistically, we verified that USP30 interacts with and stabilises Snail to promote its protein expression through deubiquitination by K48-linked polyubiquitin chains and then accelerates the EMT program. More importantly, USP30 reduced the chemosensitivity of BC cells to paclitaxel (PTX). Collectively, these data demonstrate that USP30 promotes the BC cell EMT program by stabilising Snail and attenuating chemosensitivity to PTX and may be a potential therapeutic target in BC.

The APE1/REF-1 and the hallmarks of cancer

APE1/REF-1 (apurinic/apyrimidinic endonuclease 1 / redox factor-1) is a protein with two domains, with endonuclease function and redox activity. Its main activity described is acting in DNA repair by base excision repair (BER) pathway, which restores DNA damage caused by oxidation, alkylation, and single-strand breaks. In contrast, the APE1 redox domain is responsible for regulating transcription factors, such as AP-1 (activating protein-1), NF-κB (Nuclear Factor kappa B), HIF-1α (Hypoxia-inducible factor 1-alpha), and STAT3 (Signal Transducers and Activators of Transcription 3). These factors are involved in physiological cellular processes, such as cell growth, inflammation, and angiogenesis, as well as in cancer. In human malignant tumors, APE1 overexpression is associated with lung, colon, ovaries, prostate, and breast cancer progression, more aggressive tumor phenotypes, and worse prognosis. In this review, we explore APE1 and its domain's role in cancer development processes, highlighting the role of APE1 in the hallmarks of cancer. We reviewed original articles and reviews from Pubmed related to APE1 and cancer and found that both domains of APE1/REF-1, but mainly its redox activity, are essential to cancer cells. This protein is often overexpressed in cancer, and its expression and activity are correlated to processes such as proliferation, invasion, inflammation, angiogenesis, and resistance to cell death. Therefore, APE1 participates in essential processes of cancer development. Then, the activity of APE1/REF-1 in these hallmarks suggests that targeting this protein could be a good therapeutic approach.

Transcriptional regulation of EMT transcription factors in cancer

The epithelial-mesenchymal transition (EMT) is one of the processes by which epithelial cells transdifferentiate into mesenchymal cells in the developmental stage, known as "complete EMT." In epithelial cancer, EMT, also termed "partial EMT," is associated with invasion, metastasis, and resistance to therapy, and is elicited by several transcription factors, frequently referred to as EMT transcription factors. Among these transcription factors that regulate EMT, ZEB1/2 (ZEB1 and ZEB2), SNAIL, and TWIST play a prominent role in driving the EMT process (hereafter referred to as "EMT-TFs"). Among these, ZEB1/2 show positive correlation with both expression of mesenchymal marker proteins and the aggressiveness of various carcinomas. On the other hand, TWIST and SNAIL are also correlated with the aggressiveness of carcinomas, but are not highly correlated with mesenchymal marker protein expression. Interestingly, these EMT-TFs are not detected simultaneously in any studied cases of aggressive cancers, except for sarcoma. Thus, only one or some of the EMT-TFs are expressed at high levels in cells of aggressive carcinomas. Expression of EMT-TFs is regulated by transforming growth factor-β (TGF-β), a well-established inducer of EMT, in cooperation with other signaling molecules, such as active RAS signals. The focus of this review is the molecular mechanisms by which EMT-TFs are transcriptionally sustained at sufficiently high levels in cells of aggressive carcinomas and upregulated by TGF-β during cancer progression.

Low Sulfur Amino Acid, High Polyunsaturated Fatty Acid Diet Inhibits Breast Cancer Growth

Cancer cells may acquire resistance to stress signals and reprogram metabolism to meet the energetic demands to support their high proliferation rate and avoid death. Hence, targeting nutrient dependencies of cancer cells has been suggested as a promising anti-cancer strategy. We explored the possibility of killing breast cancer (BC) cells by modifying nutrient availability. We used in vitro models of BC (MCF7 and MDA-MB-231) that were maintained with a low amount of sulfur amino acids (SAAs) and a high amount of oxidizable polyunsatured fatty acids (PUFAs). Treatment with anti-apoptotic, anti-ferroptotic and antioxidant drugs were used to determine the modality of cell death. We reproduced these conditions in vivo by feeding BC-bearing mice with a diet poor in proteins and SAAs and rich in PUFAs (LSAA/HPUFA). Western blot analysis, qPCR and histological analyses were used to assess the anti-cancer effects and the molecular pathways involved. We found that BC cells underwent oxidative damage to DNA and proteins and both apoptosis and ferroptosis were induced. Along with caspases-mediated PARP1 cleavage, we found a lowering of the GSH-GPX4 system and an increase of lipid peroxides. A LSAA/HPUFA diet reduced tumor mass and its vascularization and immune cell infiltration, and induced apoptosis and ferroptotic hallmarks. Furthermore, mitochondrial mass was found to be increased, and the buffering of mitochondrial reactive oxygen species limited GPX4 reduction and DNA damage. Our results suggest that administration of custom diets, targeting the dependency of cancer cells on certain nutrients, can represent a promising complementary option for anti-cancer therapy.

Phenotypic heterogeneity driven by plasticity of the intermediate EMT state governs disease progression and metastasis in breast cancer

The epithelial-to-mesenchymal transition (EMT) is frequently co-opted by cancer cells to enhance migratory and invasive cell traits. It is a key contributor to heterogeneity, chemoresistance, and metastasis in many carcinoma types, where the intermediate EMT state plays a critical tumor-initiating role. We isolate multiple distinct single-cell clones from the SUM149PT human breast cell line spanning the EMT spectrum having diverse migratory, tumor-initiating, and metastatic qualities, including three unique intermediates. Using a multiomics approach, we identify CBFβ as a key regulator of metastatic ability in the intermediate state. To quantify epithelial-mesenchymal heterogeneity within tumors, we develop an advanced multiplexed immunostaining approach using SUM149-derived orthotopic tumors and find that the EMT state and epithelial-mesenchymal heterogeneity are predictive of overall survival in a cohort of stage III breast cancer. Our model reveals previously unidentified insights into the complex EMT spectrum and its regulatory networks, as well as the contributions of epithelial-mesenchymal plasticity (EMP) in tumor heterogeneity in breast cancer.

Downregulation of GLYAT Facilitates Tumor Growth and Metastasis and Poor Clinical Outcomes Through the PI3K/AKT/Snail Pathway in Human Breast Cancer

Background

The Glycine N-acyltransferase (GLYAT) gene encodes a protein that catalyzes the transfer of acyl groups from acyl CoA to glycine, resulting in acyl glycine and coenzyme A. Aberrant GLYAT expression is associated with several malignant tumors, but its clinical importance in human breast cancer (BC), has yet to be fully addressed. This study aims to evaluate the clinical function of GLYAT in BC patients.

Methods

GLYAT expression was determined by immune blot and immunohistochemistry in three BC cell lines and primary cancer tissues. The MDA-MB 231 cell line was used for GLYAT gene knockdown experiments while the MCF7 cell line for overexpression experiments. Colony formation experiments, soft agar experiments, and transwell assays were utilized for further inspection of cell proliferation and migration capabilities. Immunofluorescence and western blot were used to detect markers of the epithelial-mesenchymal transition (EMT) and changes in the PI3K/AKT/Snail pathway. The role of GLYAT in tumor growth and metastasis was also assessed in nude mice in vivo. Also, a correlation analysis was performed between clinicopathological features and GLYAT expression in BC patients.

Results

GLYAT was decreased in human BC tissues and cell lines. Functional analysis showed that knockdown of GLYAT augmented BC cell proliferation in vitro and in vivo. However, this phenomenon was reversed when GLYAT was overexpressed in the transfected cells. Moreover, downregulation of GLYAT promoted the migratory properties of BC cells, likely through the activation of PI3K/AKT/Snail signaling, which subsequently induced the EMT. IHC analysis indicated that GLYAT was decreased in human BC tissues and lower GLYAT expression was correlated with histological grade, tumor TNM stage, Ki-67 status, and poorer survival in BC patients. Furthermore, lower GLYAT expression seemed as an independent risk factor related to poor prognosis in BC patients based on Cox regression analyses.

Conclusion

Our findings demonstrate that downregulation of GLYAT expression in human breast cancer is correlated with EMT via the PI3K/AKT/Snail pathway and is also associated with histological grade, tumor TNM stage, Ki-67 status, and poor survival in breast cancer patients.

Hard antler extract inhibits invasion and epithelial-mesenchymal transition of triple-negative and Her-2+ breast cancer cells by attenuating nuclear factor-κB signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Hard antler extract (HAE) is a traditional Chinese medicine and has potent antitumor, antioxidative, anti-inflammatory, and immunomodulatory activities. Previous studies have demonstrated that HAE can inhibit human prostate cancer metastasis and murine breast cancer proliferation. However, the effect of HAE on human breast cancer cells has not been clarified.

AIM OF THE STUDY

To investigate the effects and underlying mechanism of HAE on self-renewal of stem-like cells and spontaneous and transforming growth factor (TGF)-β1-enhanced wound healing, invasion and epithelial-mesenchymal transition (EMT) in breast cancer cells.

METHODS

HAE was prepared from sika deer by sequential enzymatic digestions and the active compounds were determined by HPLC. The effects of HAE on the viability, mammosphere formation, wound healing and invasion of MDA-MB-231 and SK-BR3 cells were determined. The impact of HAE treatment on spontaneous and TGF-β1-promoted EMT and the nuclear factor (NF)-κB signaling in breast cancer cells was examined by quantitative RT-PCR and western blotting.

RESULTS

Treatment with HAE at varying concentrations did not change the viability of breast cancer cells. However, HAE at 0.25 or 0.5 mg/mL significantly reduced the number and size of formed mammospheres, and inhibited spontaneous and TGF-β1-enhanced wound healing, invasion and EMT in MDA-MB-231 and SK-BR3 cells in a dose-dependent manner. TGF-β1 treatment significantly decreased IκBα expression and increased NF-kBp65 phosphorylation in breast cancer cells, indicating that TGF-β1 enhanced NF-κB signaling. In contrast, HAE treatment attenuated the spontaneous and TGF-β1-enhanced NF-κB signaling in breast cancer cells.

CONCLUSION

Our data indicated that HAE inhibited the self-renewal of stem-like cells and spontaneous and TGF-β1-enhanced wound healing, invasion and EMT in breast cancer cells by attenuating the NF-κB signaling in vitro.

LncRNA GAS5 inhibits Invasion and Migration of Lung Cancer through influencing EMT process

Background: Lung cancer is a malignant tumor in mammary gland epithelium with high morbidity and mortality among women worldwide. Long noncoding RNA GAS5 (GAS5) has been proved to be closely related with tumor progression. However, the influence of GAS5 on lung cancer and the specific mechanism remain unclear.

Methods: Cell invasion, cell migration, cell apoptosis and cell cycle were investigated after transfection with pcDNA-GAS5 and sh-GAS5. Sizes of tumors were measured by establishing transplanted tumor model in vivo. E-cadherin and N-cadherin expressions were investigated.

Results: Cell invasion and migration were inhibited markedly in GAS5 overexpressed cell line. Cell cycle results indicated that the percentage of S-phase cells was increased, and G2-phase was reduced in the GAS5 overexpression cell line. Tumor size was suppressed obviously after GAS5 overexpression treatment. GAS5 markedly inhibited the expression of E-cadherin and induced the expression of N-cadherin. GAS5 overexpression significantly inhibited lung cancer cell proliferation by increasing the E-cadherin and decreasing N-cadherin.

Conclusions: These findings provide novel evidence that GAS5 can be viewed as an anti-lung cancer agent through affecting EMT pathway.

Sanguinarine impedes metastasis and causes inversion of epithelial to mesenchymal transition in breast cancer

BACKGROUND

A large number of breast cancer patients perishes due to metastasis instead of primary tumor, but molecular mechanisms contributing towards cancer metastasis remain poorly understood. Therefore, prompting development of novel treatment is inevitable. A vast variety of plant derived natural substance possesses several therapeutically active constituents, e.g. alkaloids, flavonoids, tannins, resins, terpenoids etc. that exhibit various pharmacological properties e.g. anti-inflammatory, anti-microbial and anti-cancer properties. Sanguinarine (SAN) alkaloid found its place among such naturally occurring substances that exerts several pharmacological activities, including anti-cancer effects.

PURPOSE

Until now, role of SAN not only against epithelial-mesenchymal transition (EMT) but also against metastasis progression in breast cancer remains indistinct. Thus, aim of the present study was to investigate effects of SAN on EMT process and cancer metastasis in animal model.

METHODS

MTT assay was performed to assess SAN effects on proliferation in breast cancer. Scratch assay was performed to evaluate effects of SAN on migration in breast cancer. Colony formation assay was performed to determine effects of SAN on colonization characteristics of breast cancer. Western blotting was performed to measure EMT regulating protein expression as well as major pathway protein expression induced against TGF-β treatment in breast cancer. Tail vein method of injecting breast cancer cells in bulb/c mice was conducted to study metastasis progression and thereafter assessing effects of SAN against metastasis in mice.

RESULTS

In vivo results: MTT assay performed, demonstrated dose dependent inhibition of cell proliferation in breast cancer. Scratch assay results showed, SAN played a major role as migration inhibitor in estrogen receptor positive (ER+) breast cancer. Colony forming assay results demonstrated that SAN constrains ability of breast cancer to develop into well-defined colonies. Western blotting results for EMT regulating protein expression, after TGF-β treatment showed, SAN inhibited cadherin switch in ER+ breast cancer. Moreover, expression of pathway proteins involved in EMT process after TGF-β treatment i.e. Smad, PI3K/Akt and MAP kinase were significantly masked against SAN treatment.

IN VIVO RESULTS

The appearance of metastatic nodules in lung tissues of mice model, helps to study the effects of SAN against metastasis in bulb/c mice. The obtained results have confirmed that SAN impeded lung metastasis. The macroscopic examination has confirmed metastasis inhibitory role of SAN in breast cancer. The Hematoxylin and eosin (H&E) staining results further advocate anti-metastatic characteristics of SAN, presented by fewer metastatic nodule and lesions appearance in SAN treated mice compared to untreated metastasis mice.

CONCLUSION

In summary, SAN displayed prominent anti-metastatic effects in animal model and anti-proliferation effects together with significant inhibitory potential on EMT regulating protein expression against TGF-β treatment in ER+ breast cancer. So, overall findings of our study highlighted the pre-clinical significance of SAN in animal model therefore, further studies in humans as a part of clinical trial will be needed to establish pharmacokinetics and other effects of SAN, so that it can be a potential candidate for future treatment of metastatic breast cancer (MBC).

Prognostic and clinicopathological values of tissue expression of MFAP5 and ITM2A in triple-negative breast cancer: an immunohistochemical study

Introduction

Triple-negative breast cancer (TNBC) is a markedly aggressive molecular subtype of breast cancer; there is an urgent need to clarify the molecular mechanisms underlying the progression and metastases of BLBC, in order to find a novel targeted therapy. Microfibrillar-associated protein 5 (MFAP5) plays an essential role in the regulation of cell behaviour and survival. Integral membrane protein 2A (ITM2A) is a type II transmembrane protein, which is a member of a family of autophagy related proteins.

The aim of this study was to assess the expression of MFAP5 and ITM2A proteins in tissues of BLBC using immunohistochemistry, in order to correlate the expression with clinicopathological and prognostic parameters of such aggressive cancer.

Material and methods

The present study included sections from archived paraffin blocks retrieved from 120 patients with TNBC. We collected cases from three years, i.e. from 2016 to 2019. We assessed expression of MFAP5 and ITM2A using immunohistochemistry.

Results

High expression of MFAP5 and low expression of ITM2A was associated with advanced stage (p = 0.007), higher grade of tumour (p = 0.005 and p = 0.004, respectively), the presence of lymph nodes metastases (p < 0.001 and p = 0.002, respectively), lower three-year RFS rate (p < 0.001 and p = 0.016, respectively), and lower three-year OS rate (p < 0.001).

Conclusions

MFAP5 and ITM2A are novel prognostic biomarkers for breast cancer and might be considered as promising therapeutic targets for patients with breast cancer, particularly TNBC molecular subtype, in the future.

Hydroxytyrosol and Oleuropein Inhibit Migration and Invasion via Induction of Autophagy in ER-Positive Breast Cancer Cell Lines (MCF7 and T47D)

Hydroxytyrosol (HT) and oleuropein (OL), the most abundant of the phenolic compounds in olives, have anticancer properties against breast cancer (BC). However, little attention has been paid to the mechanism of HT or OL in BC cells. The objective of this study was to identify the underlying molecular mechanisms of these compounds. ER-positive BC MCF7 and T47D cells were treated with HT and OL in combination with hepatocyte growth factor (HGF), rapamycin (Rapa, an agonist of autophagy) or 3-methyladenine (3-MA, an inhibitor of autophagy). Cell viability, metastasis capability and autophagy-related proteins were evaluated by wound healing assays, Transwell assays and Western blot. HT and OL reduced the cell viability of MCF-7 and T47D cells in a dose-dependent manner. Both cells were more sensitive to HT than OL. In addition, Rapa significantly inhibited HGF-induced migration and invasion, indicating that metastases of both BC cells could be inhibited by suppression of autophagy. Moreover, HT and OL significantly blocked HGF- or 3-MA-induced cell migration and invasion by reversing LC3II/LC3I and Beclin-1 downregulation and p62 upregulation. These findings revealed that HT and OL could suppress migration and invasion by activating autophagy in ER-positive BC cells, which might be a promising therapeutic strategy.

Phosphorylation of BCKDK of BCAA catabolism at Y246 by Src promotes metastasis of colorectal cancer

Branched-chain α-keto acid dehydrogenase kinase (BCKDK), the key enzyme of branched-chain amino acids (BCAAs) metabolism, has been reported to promote colorectal cancer (CRC) tumorigenesis by upregulating the MEK-ERK signaling pathway. However, the profile of BCKDK in metastatic colorectal cancer (mCRC) remains unknown. Here, we report a novel role of BCKDK in mCRC. BCKDK is upregulated in CRC tissues. Increased BCKDK expression was associated with metastasis and poor clinical prognosis in CRC patients. Knockdown of BCKDK decreased CRC cell migration and invasion ex vivo, and lung metastasis in vivo. BCKDK promoted the epithelial mesenchymal transition (EMT) program, by decreasing the expression of E-cadherin, epithelial marker, and increasing the expression of N-cadherin and Vimentin, which are mesenchymal markers. Moreover, BCKDK-knockdown experiments in combination with phosphoproteomics analysis revealed the potent role of BCKDK in modulating multiple signal transduction pathways, including EMT and metastasis. Src phosphorylated BCKDK at the tyrosine 246 (Y246) site in vitro and ex vivo. Knockdown and knockout of Src downregulated the phosphorylation of BCKDK. Importantly, phosphorylation of BCKDK by Src enhanced the activity and stability of BCKDK, thereby promoting the migration, invasion, and EMT of CRC cells. In summary, the identification of BCKDK as a novel prometastatic factor in human CRC will be beneficial for further diagnostic biomarker studies and suggests novel targeting opportunities.

Paeoniflorin: a monoterpene glycoside from plants of Paeoniaceae family with diverse anticancer activities

OBJECTIVES

Paeoniflorin, a representative pinane monoterpene glycoside in plants of Paeoniaceae family, possesses promising anticancer activities on diverse tumours. This paper summarized the advance of Paeoniflorin on cancers in vivo and in vitro, discussed the related molecular mechanisms, as well as suggested some perspectives of the future investigations.

KEY FINDINGS

Anticancer activities of paeoniflorin have been comprehensively investigated, including liver cancer, gastric cancer, breast cancer, lung cancer, pancreatic cancer, colorectal cancer, glioma, bladder cancer and leukaemia. Furthermore, the potential molecular mechanisms corresponding to the antitumour effects of Paeoniflorin might be related to the following aspects: inhibition of tumour cell proliferation and neovascularization, induction apoptosis, and inhibition of tumour invasion and metastasis.

SUMMARY

Paeoniflorin has wide spectrum antitumour activities; however, in vivo and clinical investigations on antitumour effect of Paeoniflorin are lacking which should be focused on further studies. Our present review on antitumour effects of Paeoniflorin would be beneficial for the further molecular mechanisms study, candidate antitumour drug development and clinical research of Paeoniflorin in the future.

MFAP5 promotes basal-like breast cancer progression by activating the EMT program

Purpose

Human basal-like breast cancer (BLBC) is an aggressive malignancy with poor prognosis. Since most current treatments are ineffective, there is an urgent need to identify therapeutic targets for BLBC. Microfibrillar-associated protein 5 (MFAP5) plays an important role in the integration of elastic microfibers and the regulation of endothelial cell behaviors. We previously demonstrated that MFAP5 was significantly overexpressed in BLBC tissues and associated with poor metastasis-free survival of patients with BLBC. However, the detailed role of MFAP5 in BLBC is unclear. Thereby, the current study aimed to investigate the underlying function of MFAP5 in BLBC.

Method

Functional analyses were conducted for the role of MFAP5 in BLBC in vitro and in vivo.

Results

Overexpression of MFAP5 resulted in a significant increase in the proliferation, migration, invasion and epithelial–mesenchymal transition (EMT) markers in BLBC in vitro and in vivo. In addition, other metastasis animal models by tail intravenous injection of BT20 cells further confirmed that MFAP5 overexpression promoted BLBC proliferation and BT20 cells metastasis. We found that the TGF-β or Notch inhibitor significantly reversed the tumorigenicity and metastasis of MFAP5-induced BLBC cells.

Conclusion

Our findings suggest that MFAP5 may promote EMT in BLBC metastasis via the TGF-β/Notch pathway.

Electronic supplementary material

The online version of this article (10.1186/s13578-019-0284-0) contains supplementary material, which is available to authorized users.

IL‑6 prevents CXCL8‑induced stimulation of EpCAM expression in ovarian cancer cells

Epithelial cell adhesion molecule (EpCAM), which is expressed in the majority of epithelial tissues, exhibits tumor growth promoting abilities and is overexpressed in human epithelial ovarian cancer. Therefore, EpCAM is considered to be a promising target for specific immune‑based therapies. The present study evaluated the role of IL‑6 and IL‑8 in the expression of EpCAM in the A2780 human ovarian cancer cell line. Furthermore, the cellular localization of the EpCAM protein in A2780 cells was determined and the effect of EpCAM inhibition on the proliferation of the A2780 cells was investigated. An MTT assay demonstrated that blocking EpCAM with anti‑EPCAM antibodies had no effect on cellular metabolic activity (proliferation). Gene expression analysis revealed that IL‑8 increased EpCAM expression, whereas IL‑6 and the combination of IL‑6/IL‑8 had no effect on EpCAM expression. Immunofluorescence analysis confirmed that EpCAM is expressed on A2780 cell membranes. The present results demonstrated that IL‑8 increased EpCAM expression at the mRNA level in ovarian cancer cells and suggested a potential role of IL‑6 as an inhibitor of IL‑8‑stimulated EpCAM expression.

The Role of Tumor Microenvironment and Impact of Cancer Stem Cells on Breast Cancer Progression and Growth

Breast cancer is not only a mass of genetically abnormal tissue in the breast. This is a well-organized system of a complex heterogeneous tissue. Cancer cells produce regulatory signals that stimulate stromal cells to proliferate and migrate; then, stromal elements respond to these signals by releasing components necessary for tumor development that provide structural support, vasculature, and extracellular matrices. Developing tumors can mobilize a variety of cell types from both local and distant niches via secret chemical factors derived from cancer cells themselves or neighboring cells disrupted by growing neoplasm, such as fibroblasts, immune inflammatory cells, and endothelial cells. CSCs are a group of very few cells that are tumorigenic (able to form tumors) and are defined as those cells within a tumor that can self-renew and lead to tumorigenesis. BCSCs represent a small population of cells that have stem cell characteristics and are related to breast cancer. There are different theories about the origin of BCSCs. BCSCs are responsible for breast carcinoma metastasis. Usually, there is a metastatic spread to the bones, and rarely to the lungs and liver. A phenomenon that allows BCSCs to make the transition from epithelial to mesenchymal expression and thus avoid the effect of cytotoxic agents is the epithelial-mesenchymal transition (EMT). During this process, cells change their molecular characteristics in terms of loss of epithelial characteristics taking the mesenchymal phenotype. This process plays a key role in the progression, invasion, and metastasis of breast tumors.

Oridonin inhibits VEGF-A-associated angiogenesis and epithelial-mesenchymal transition of breast cancer in vitro and in vivo

Metastasis is the primary cause of mortality in patients with breast cancer and lacks effective therapeutic agents. Oridonin, an active diterpenoid compound isolated from Rabdosia rubescens, was identified to be the most potent anti-tumor ingredient. However, the molecular mechanisms responsible for its anti-metastatic effects remain unclear. In the present study, oridonin significantly suppressed the migration, invasion and adhesion of MDA-MB-231 and 4T1 breast cancer cells, and inhibited tube formation of human umbilical vein endothelial cells in a dose-dependent manner. The expression levels of epithelial-mesenchymal transition (EMT)-associated marker and the hypoxia inducible factor 1α (HIF-1α)/vascular endothelium growth factor (VEGF) signaling pathway mRNA and proteins were determined by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively in vitro. The results demonstrated that oridonin effectively inhibited EMT as demonstrated by the significant increases in the expression levels of E-cadherin, and decreased expression of N-cadherin, Vimentin and Snail. In addition, oridonin exerted its anti-angiogenesis activity through significantly decreasing HIF-1α, VEGF-A and VEGF receptor-2 protein expression. Furthermore, oridonin was demonstrated to decrease the micro-vessel density as evidenced by the decreased expression of cluster of differentiation 31, a marker for neovasculature. In brief, oridonin inhibits tumor cell migration, invasion and adhesion, as well as tumor angiogenesis, which are mediated by suppressing EMT and the HIF-1α/VEGF signaling pathway. The results of the present study suggest that oridonin may be a promising anti-metastatic agent in breast cancer treatment.

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.

OTUB1 promotes esophageal squamous cell carcinoma metastasis through modulating Snail stability

Snail is a key regulator of epithelial-mesenchymal transition (EMT) and plays an important role in tumor progression and metastasis. Snail is rapidly degraded in the cells and its protein level is critically controlled. Although several E3 ligases regulating Snail degradation have been defined, the deubiquitinases (DUBs) responsible for Snail deubiquitination are less studied. We identified ovarian tumor domain-containing ubiquitin aldehyde binding protein 1 (OTUB1) as a DUB that stabilizes Snail through preventing its ubiquitination and proteasomal degradation. Functionally, OTUB1 facilitates metastasis of esophageal squamous cell carcinoma (ESCC) through promoting Snail protein stability. Moreover, OTUB1 is highly expressed in ESCC and higher expression of OTUB1 predicts poor prognosis. These findings suggest that OTUB1 is an essential regulator of Snail and plays a critical role in facilitating esophageal cancer progression.

Paeoniflorin Inhibits Migration and Invasion of Human Glioblastoma Cells via Suppression Transforming Growth Factor β-Induced Epithelial-Mesenchymal Transition

Paeoniflorin (PF) is a polyphenolic compound derived from Radix Paeoniae Alba thathas anti-cancer activities in a variety of human malignancies including glioblastoma. However, the underlying mechanisms have not been fully elucidated. Epithelial to mesenchymal transition (EMT), characterized as losing cell polarity, plays an essential role in tumor invasion and metastasis. TGFβ, a key member of transforming growth factors, has been demonstrated to contribute to glioblastoma aggressiveness through inducing EMT. Therefore, the present studies aim to investigate whether PF suppresses the expression of TGFβ and inhibits EMT that plays an important role in anti-glioblastoma. We found that PF dose-dependently downregulates the expression of TGFβ, enhances apoptosis, reduces cell proliferation, migration and invasion in three human glioblastoma cell lines (U87, U251, T98G). These effects are enhanced in TGFβ siRNA treated cells and abolished in cells transfected with TGFβ lentiviruses. In addition, other EMT markers such as snail, vimentin and N-cadherin were suppressed by PF in these cell lines and in BALB/c nude mice injected with U87 cells. The expression of MMP2/9, EMT markers, are also dose-dependently reduced in PF treated cells and in U87 xenograft mouse model. Moreover, the tumor sizes are reduced by PF treatment while there is no change in body weight. These results indicate that PF is a potential novel drug target for the treatment of glioblastoma by suppression of TGFβ signaling pathway and inhibition of EMT.

Narrower insight to SIRT1 role in cancer: A potential therapeutic target to control epithelial-mesenchymal transition in cancer cells

The epithelial-mesenchymal transition (EMT) is a highly networked cellular process which involves cell transition from the immotile epithelial to the motile mesenchymal phenotype, whereby cells lose their cell-cell adhesion and cell polarity. This important process is one of the underlying mechanisms for enabling invasion and metastasis of cancer cells which is considered as malignant phase of tumor progression. However, the molecular mechanisms of this process are not fully clarified. It is reported that Sirtuin1 (SIRT1), a NAD+ dependent class III histone deacetylase is associated with tumor metastasis through positive regulation of EMT in several types of cancers. Recent studies confirmed that up and down regulation of SIRT1 expression remarkably change the migration ability of different cancer cells in vitro and tumor metastasis in vivo. Also, according to this fact that carcinomas as the main human solid tumors, originate from different epithelial cell types, SIRT1 role in EMT has received a great attention due to its potential role in tumor development and metastasis. Therefore, SIRT1 has been proposed as a key regulator of cancer metastasis by promoting EMT, although little is known about the cleared effect of SIRT1 in this transition. Our aim in this review is to explain in more detail the role of SIRT1 in various signaling pathways related to carcinogenesis, with the focus on the promoting role of SIRT1 in EMT as a potential therapeutic target to control EMT and to prevent cancer progression.

MiR-29b/TET1/ZEB2 signaling axis regulates metastatic properties and epithelial-mesenchymal transition in breast cancer cells

MiR-29b has been reported to be both a suppressor and a promoter in breast cancer (BC) cells proliferation and metastasis. Significant efforts have been made to explain the seemingly contradictory effects of miR-29b on BC, but no answer has yet been clearly verified. In this study, we overexpressed and knocked down miR-29b in BC cell lines, modulated expression of its downstream target gene TET1 and downregulated a downstream target gene of TET1, ZEB2, to explore the regulatory mechanism of miR-29b in BC cell proliferation, migration and epithelial-mesenchymal transition (EMT). Our results showed lower expression of miR-29b in BC samples and cell lines. Functional assays showed that miR-29b overexpression resulted in a higher cell proliferation, greater colony formation, higher migration rate and EMT. A dual luciferase assay identified TET1 as a direct target of miR-29b. As the promoting effects of miR-29b in the proliferation and metastasis of MDA-MB-231 and MCF-7, knockdown of TET1 also led to increased proliferation, colony formation, invasion and EMT. Further, we found that TET1 bound to the promoter of ZEB2, and siTET1 enhanced ZEB2 expression. Disruption of ZEB2 expression inhibited BC cells proliferation, colony formation and invasion. Our results establish the miR-29b/TET1/ZEB2 pathway in BC cell proliferation, migration and provide a theoretical basis for further research on the molecular mechanisms and new clinical treatments for BC.

Exploring association between statin use and breast cancer risk: an updated meta-analysis

PURPOSE

The benefits of statin treatment for preventing cardiac disease are well established. However, preclinical studies suggested that statins may influence mammary cancer growth, but the clinical evidence is still inconsistent. We, therefore, performed an updated meta-analysis to provide a precise estimate of the risk of breast cancer in individuals undergoing statin therapy.

METHODS

For this meta-analysis, we searched PubMed, the Cochrane Library, Web of Science, Embase, and CINAHL for published studies up to January 31, 2017. Articles were included if they (1) were published in English; (2) had an observational study design with individual-level exposure and outcome data, examined the effect of statin therapy, and reported the incidence of breast cancer; and (3) reported estimates of either the relative risk, odds ratios, or hazard ratios with 95% confidence intervals (CIs). We used random-effect models to pool the estimates.

RESULTS

Of 2754 unique abstracts, 39 were selected for full-text review, and 36 studies reporting on 121,399 patients met all inclusion criteria. The overall pooled risks of breast cancer in patients using statins were 0.94 (95% CI 0.86-1.03) in random-effect models with significant heterogeneity between estimates (I ² = 83.79%, p = 0.0001). However, we also stratified by region, the duration of statin therapy, methodological design, statin properties, and individual stain use.

CONCLUSIONS

Our results suggest that there is no association between statin use and breast cancer risk. However, observational studies cannot clarify whether the observed epidemiologic association is a causal effect or the result of some unmeasured confounding variable. Therefore, more research is needed.