Molecular markers of epithelial-to-mesenchymal transition are associated with tumor aggressiveness in breast carcinoma

An update on existing therapeutic options and status of novel anti-metastatic agents in breast cancer: Elucidating the molecular mechanisms underlying the pleiotropic action of Withania somnifera (Indian ginseng) in breast cancer attenuation

Major significant advancements in pharmacology and drug technology have been made to heighten the impact of cancer therapies, improving the life expectancy of subjects diagnosed with malignancy. Statistically, 99% of breast cancers occur in women while 0.5-1% occur in men, the female gender being the strongest breast cancer risk factor. Despite several breakthroughs, breast cancer continues to have a worldwide impact and is one of the leading causes of mortality. Additionally, resistance to therapy is a crucial factor enabling cancer cell persistence and resurgence. As a result, the search and discovery of novel modulatory agents and effective therapies capable of controlling tumor progression and cancer cell proliferation is critical. Withania somnifera (L.) Dunal (WS), commonly known as Indian ginseng, has long been used traditionally for the treatment of several ailments in the Indian context. Recently, WS and its phytoconstituents have shown promising anti-breast cancer properties and, as such, can be employed as prophylactic as well as therapeutic adjuncts to the main line of breast cancer treatment. The present review is an attempt to explore and provide experimental evidences in support of the prophylactic and therapeutic potential of WS in breast cancer, along with a deeper insight into the multiple molecular mechanisms and novel targets through which it acts against breast and other hormonally-induced cancers viz. ovarian, uterine and cervical. This exploration might prove crucial in providing better understanding of breast cancer progression and metastasis and its use as an adjunct in improving disease prognosis and therapeutic outcome.

Exploring the impact of PDGFD in osteosarcoma metastasis through single-cell sequencing analysis

PURPOSE

The overall survival rate for metastatic osteosarcoma hovers around 20%. Responses to second-line chemotherapy, targeted therapies, and immunotherapies have demonstrated limited efficacy in metastatic osteosarcoma. Our objective is to validate differentially expressed genes and signaling pathways between non-metastatic and metastatic osteosarcoma, employing single-cell RNA sequencing (scRNA-seq) and additional functional investigations. We aim to enhance comprehension of metastatic mechanisms and potentially unveil a therapeutic target.

METHODS

scRNA-seq was performed on two primary osteosarcoma lesions (1 non-metastatic and 1 metastatic). Seurat package facilitated dimensionality reduction and cluster identification. Copy number variation (CNV) was predicted using InferCNV. CellChat characterized ligand-receptor-based intercellular communication networks. Differentially expressed genes underwent GO function enrichment analysis and GSEA. Validation was achieved through the GSE152048 dataset, which identified PDGFD-PDGFRB as a common ligand-receptor pair with significant contribution. Immunohistochemistry assessed PDGFD and PDGFRB expression, while multicolor immunofluorescence and flow cytometry provided insight into spatial relationships and the tumor immune microenvironment. Kaplan-Meier survival analysis compared metastasis-free survival and overall survival between high and low levels of PDGFD and PDGFRB. Manipulation of PDGFD expression in primary osteosarcoma cells examined invasion abilities and related markers.

RESULTS

Ten clusters encompassing osteoblasts, osteoclasts, osteocytes, fibroblasts, pericytes, endothelial cells, myeloid cells, T cells, B cells, and proliferating cells were identified. Osteoblasts, osteoclasts, and osteocytes exhibited heightened CNV levels. Ligand-receptor-based communication networks exposed significant fibroblast crosstalk with other cell types, and the PDGF signaling pathway was activated in non-metastatic osteosarcoma primary lesion. These results were corroborated by the GSE152048 dataset, confirming the prominence of PDGFD-PDGFRB as a common ligand-receptor pair. Immunohistochemistry demonstrated considerably greater PDGFD expression in non-metastatic osteosarcoma tissues and organoids, correlating with extended metastasis-free and overall survival. PDGFRB expression showed no significant variation between non-metastatic and metastatic osteosarcoma, nor strong correlations with survival times. Multicolor immunofluorescence suggested co-localization of PDGFD with PDGFRB. Flow cytometry unveiled a highly immunosuppressive microenvironment in metastatic osteosarcoma. Manipulating PDGFD expression demonstrated altered invasive abilities and marker expressions in primary osteosarcoma cells from both non-metastatic and metastatic lesions.

CONCLUSIONS

scRNA-seq illuminated the activation of the PDGF signaling pathway in primary lesion of non-metastatic osteosarcoma. PDGFD displayed an inhibitory effect on osteosarcoma metastasis, likely through the suppression of the EMT signaling pathway.

PRIM2: A Marker of MYC-driven Hyper-proliferation, Disease Progression, Tumor Aggressiveness and Poor Survival in Glioma Patients

BACKGROUND/AIM

Gliomas are the most prevalent brain tumors with metabolic alterations playing a pivotal role in disease progression. However, the precise coordination of metabolic alterations with tumor-promoting cellular mechanisms, leading to tumor initiation, progression, and aggressiveness, resulting in poor outcomes, remains poorly understood in gliomas.

MATERIALS AND METHODS

We conducted a metabolism-targeted differential gene expression analysis using glioma patients' expression profiling data from The Cancer Genome Atlas (TCGA) database. In addition, pathway enrichment analysis, gene set enrichment analysis (GSEA), transcription factor prediction, network construction, and correlation analyses were performed. Survival analyses were performed in R. All results were validated using independent GEO expression datasets.

RESULTS

Metabolism-targeted analysis identified 5 hits involved in diverse metabolic processes linking them to disease aggressiveness in gliomas. Subsequently, we established that cell cycle progression and hyper-proliferation are key drivers of tumor progression and aggressiveness in gliomas. One of the identified metabolic hits, DNA primase 2 (PRIM2), a gene involved in DNA replication was found directly associated with cell cycle progression in gliomas. Furthermore, our analysis indicated that PRIM2, along with other cell cycle-related genes, is under the control of and regulated by the oncogenic MYC transcription factor in gliomas. In addition, PRIM2 expression alone is enough to predict MYC-driven cell cycle progression and is associated with tumor progression, aggressive disease state, and poor survival in glioma patients.

CONCLUSION

Our findings highlight PRIM2 as a marker of MYC-driven cell cycle progression and hyper-proliferation, disease onset and progression, tumor aggressiveness, and poor survival in glioma patients.

Stem Cell Protein PIWIL2 Promotes EMT Process and Stem Cell-Like Properties in MCF7 Breast Cancer Cell Line

Background

Piwi-like RNA-mediated gene silencing 2 (PIWIL2) is a member of AGO/PIWI gene family, which is enriched in cancer stem cells (CSCs). The purpose of this research was to investigate the overexpression of PIWIL2 and its role in the induction of EMT and CSC properties in MCF7 breast cancer cell line.

Materials and Methods

MCF7 cells were transfected with the human gene PIWIL2 (Hili) under the control of CMV promoter utilizing the neon electroporation method. Subsequently, the selection was conducted using G418, and doubling time was calculated in the transformed and control cells. RT and real-time PCR were also performed to analyze the expression of epithelial and mesenchymal genes and those related to CSCs.

Results

According to the observations from this study, transfecting MCF7 cells with PIWIL2 triggered the conversion of epithelial cells to mesenchymal cells and induced the genes specific for breast CSCs, which was coincident with 9-h reduction in the doubling time of the transfected cells. Furthermore, the molecular analyses revealed a significant reduction in the expression of epithelial markers, while a significant increase was detected in the expression of mesenchymal genes and many CSC biomarkers.

Conclusion

PIWIL2 protein acts as a master regulatory protein that is able to manipulate the transcription through specific signaling pathways, which allow the cells to gain stem cell-like properties.

The significance of immune microenvironment in patients with endometriosis

Endometriosis represents an estrogen-dependent disease of the female reproductive system and intra- and extraperitoneal regions, with chronic feature. Currently, immune cells, such as macrophages and lymphocytes, are considered to play a pivotal role in angiogenesis and invasion of endometriotic cells through matrix remodeling. Additionally, various studies have revealed the role of E-cadherin, β-catenin, along with steroid hormone receptors in endometriosis development. In this context, our study aimed to analyze the relationship between the cellular immune profile and E-cadherin, β-catenin, estrogen receptor alpha (ERα), and progesterone receptor (PR) immunoexpression in endometriosis tissues, along with an analysis of the possible association between serological parameters and immunohistochemical (IHC) markers. The study included 53 patients diagnosed with ovarian or cutaneous abdominal wall endometriosis, which have been investigated by routine histology, immunohistochemistry, and serum analysis. The IHC exam showed an increased density of cluster of differentiation (CD)4+ T-cells, CD8+ T-cells, and CD68+ macrophages, along with variable increased expressions of E-cadherin, β-catenin, ERα, and PR. Statistical analysis revealed an intense positive correlation between CD68 and PR expression (p<0.05), without any other statistically significant correlations between IHC markers or between IHC and serological markers. Our study supports that endometriosis is an immune-dependent disease characterized by an abnormal morphological profile of T-cells and macrophages in endometriotic implants. Our study provides additional data useful in the understanding the immune milieu of endometriosis in the context of its complex pathogenic molecular mechanism. Further research is needed to develop new immunological therapeutic approaches, like immune checkpoint inhibitors administration or T-cell-targeted immunotherapy in these patients.

Inhibition of WNT signaling by conjugated microRNA nano-carriers: A new therapeutic approach for treating triple-negative breast cancer a perspective review

Triple-Negative Breast Cancer is the most aggressive form and accounts the 15%-25% of all breast cancer. Receptors are absent in triple-negative breast cancer, which makes them unresponsive to the current hormonal therapies. The patients with TNBC are left with the option of cytotoxic chemotherapy. The Wnt pathways are connected to cancer, and when activated, they result in mammary hyperplasia and tumors. The tumor suppressor microRNAs can block tumor cell proliferation, invasion, and migration, lead to cancer cell death, and are also known to down-regulate the WNT signaling. Nanoparticles with microRNA have been seen to be more effective when compared with their single release. In this review, we have tried to understand how Wnt signaling plays a crucial role in TNBC, EMT, metastasis, anti-drug resistance, and regulation of Wnt by microRNA. The role of nano-carriers in delivering micro-RNA. The clinical biomarkers, including the present state-of-the-art, involve novel pathways of Wnt.

Metabolomics and EMT Markers of Breast Cancer: A Crosstalk and Future Perspective

Cancer cells undergo transient EMT and MET phenomena or vice versa, along with the parallel interplay of various markers, often correlated as the determining factor in decoding metabolic profiling of breast cancers. Moreover, various cancer signaling pathways and metabolic changes occurring in breast cancer cells modulate the expression of such markers to varying extents. The existing research completed so far considers the expression of such markers as determinants regulating the invasiveness and survival of breast cancer cells. Therefore, this manuscript is crosstalk among the expression levels of such markers and their correlation in regulating the aggressiveness and invasiveness of breast cancer. We also attempted to cover the possible EMT-based metabolic targets to retard migration and invasion of breast cancer.

Fish oil supplementation increases expression of mammary tumor apoptosis mediators and reduces inflammation in an obesity-associated HER-2 breast cancer model

Obesity is associated with inflammation and has been shown to increase breast cancer severity. The objective of this study was to examine the effect of fish oil (FO) supplementation in obesity-associated mammary tumorigenesis in the MMTV-neu(ndl)-YD5 mouse model of human epidermal growth factor receptor-2 positive BC. Female mice were fed one of three diets for 16 weeks: i) high fat diet [HF, % kacl: 41.2% lard, 18.7% corn oil (CO)], ii) an isocaloric HF plus menhaden FO diet (HF+FO, % kcal: 41.2 lard, 13.4% CO, 5.3% FO), iii) low fat diet (LF, % kcal: 4.7% lard, 6% CO). HF mice had increased body weight, visceral adipose weight and serum hormone concentrations (increased leptin and resistin; decreased adiponectin) versus LF, which was attenuated in the HF+FO group versus HF (P<.05). Compared to HF, tumor onset was delayed in HF+FO and LF mice (P<0.05). Compared to HF, HF+FO reduced mammary tumor multiplicity (-27%), tumor weight (-46%) and total tumor volume (-50%) (P<0.05). Additionally, HF+FO reduced mammary tumor multiplicity (-33%), tumor weight (-39%) and total tumor volume (-60%) versus LF. HF+FO improved mammary tumor apoptosis status with increased expression of pro-apoptotic Bad and decreased expression of anti-apoptotic Bcl-xLmediators versus HF (P<0.05). Additionally, HF+FO decreased tumor protein expression of activated Akt, NFκB p65 and STAT3, versus HF (P<0.05). Tumor mRNA expression of inflammatory mediators TNFα, IL-6 and leptin were reduced in HF+FO, whereas IL-10 expression was increased compared to HF (P<0.05). Collectively these results demonstrate the efficacy of FO supplementation for improving obesity-associated breast cancer outcomes.

Insights into molecular pathways of endometriosis and endometriosis-related ovarian carcinoma

Background: Endometriosis is a benign estrogen-dependent gynecological disease involving components of the female genital tract (uterus, Fallopian tubes, ovaries, large, round, and utero-sacral ligaments) and intra- and extraperitoneal regions. Since the moment of its etiopathogeny has been identified, the intrinsic capacity of endometriosis malignant transformation has been hypothesized. Patients,Materials and Methods: Our study included a total number of 50 patients diagnosed with endometriosis (31 cases) and endometriosis-related ovarian carcinoma (EOC) (19 cases). A clinicopathological and immunohistochemical study directed towards the detection of atypical transition lesions and the similitudes in epithelial–mesenchymal transition (EMT) phenomenon [E-cadherin/β-catenin/cytokeratin 18 (CK18)], apoptosis [B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X (Bax)], and hormonal dynamics mirrored by the immunoexpression of estrogen receptor (ER) and progesterone receptor (PR) in endometriosis and EOC glands and stroma has been performed. Results: Our study showed a higher immunoexpression of CK18 and E-cadherin in endometriosis than in neoplastic counterparts, while β-catenin had a stronger immunoexpression in tumors compared with endometriotic areas, with statistically significant differences between the studied groups. Bcl-2/Bax higher rate in endometriosis had a statistically significant association to a more aggressive tumor behavior (p=0.020). ER immunoexpression was stronger in endometriosis, with less negative scores compared to EOC, while PR immunoexpression was stronger in endometriosis, with a lower percent of negative scores compared to EOC. PR immunostaining was correlated to ovarian location of endometriosis (p=0.004) and tumor grade of EOC (p=0.027). Stromal ER and PR immunoexpression has been significantly lower in endometriosis in comparison to tumor stroma (p=0.001) and PR stromal immunoexpression had been higher in more differentiated tumors compared to less differentiated types (p=0.005). Conclusions: Our study supports that endometriosis is a precursor of EOC by the identification and the coexistence of both lesions in the investigated cases, the identification of intermediate lesions, as well as the expression of EMT immunomarkers, along with apoptosis and steroid receptors immunoexpression.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

Can NF-κB Be Considered a Valid Drug Target in Neoplastic Diseases? Our Point of View

Multidrug resistance (MDR), of the innate and acquired types, is one of major problems in treating tumor diseases with a good chance of success. In this review, we examine the key role of nuclear factor-kappa B (NF-κB) to induce MDR in three tumor models characterized precisely by innate or acquired MDR, in particular triple negative breast cancer (TNBC), hepatocellular carcinoma (HCC), and acute myeloid leukemia (AML). We also present different pharmacological approaches that our group have employed to reduce the expression/activation of this transcriptional factor and thus to restore chemo-sensitivity. Finally, we examine the latest scientific evidence found by other groups, the most significant clinical trials regarding NF-κB, and new perspectives on the possibility to consider this transcriptional factor a valid drug target in neoplastic diseases.

Histone deacetylase inhibitors reinforce the phenotypical markers of breast epithelial or mesenchymal cancer cells but inhibit their migratory properties

Introduction

Histone deacetylase inhibitors (HDIs) are a group of compounds that exhibit anticancer activity, but their significance and usefulness in breast cancer (BC) treatment are still controversial. The ability of cancer cells to invade and migrate is augmented by the acquisition of a mesenchymal phenotype – a process known as epithelial-to-mesenchymal transition (EMT). Changes in the expression level of different cadherins, so-called cadherin switches, have been used to monitor the EMT process in development and tumor progression, in particular migration and invasion potential. The aim of this study was to analyze the influence of two HDIs – valproic acid (VPA) and vorinostat (SAHA) – on the migration potential of different BC cell types, as well as on EMT, or its reverse process – mesenchymal-to-epithelial transition, progression by means of shift in epithelial and mesenchymal marker expression.

Methods

HDI treatment-induced expression of E- and N-cadherin at the mRNA and protein levels was evaluated by qPCR, Western blotting and immunostaining methods, respectively. BC cell proliferation and migration were assessed by BrdU, xCELLigence system and wound-healing assay.

Results

VPA and SAHA inhibited the proliferation and migration in a dose- and time-dependent manner, regardless of the BC cell type. Unawares, BC cells having a more mesenchymal phenotype (MDA-MB-468) were found to overexpress N-cadherin, whereas BC lines having an epithelial phenotype (T47D, MCF7) responded to HDI treatment by a significant increase of E-cadherin expression.

Discussion

We suggest that HDAC inhibition results in a more relaxed chromatin concomitant to an increase in the expression of already expressing genes.

Conclusion

By using multiple cancer cell lines, we conclude that HDI induction or reversal of EMT is not a universal mechanism, yet inhibition of cell migration is, and thus EMT should not be considered as the only measurement for tumor aggressiveness.

Profiling of Invasive Breast Carcinoma Circulating Tumour Cells-Are We Ready for the 'Liquid' Revolution?

As dissemination through blood and lymph is the critical step of the metastatic cascade, circulating tumour cells (CTCs) have attracted wide attention as a potential surrogate marker to monitor progression into metastatic disease and response to therapy. In patients with invasive breast carcinoma (IBC), CTCs are being considered nowadays as a valid counterpart for the assessment of known prognostic and predictive factors. Molecular characterization of CTCs using protein detection, genomic and transcriptomic panels allows to depict IBC biology. Such molecular profiling of circulating cells with increased metastatic abilities appears to be essential, especially after tumour resection, as well as in advanced disseminated disease, when information crucial for identification of therapeutic targets becomes unobtainable from the primary site. If CTCs are truly representative of primary tumours and metastases, characterization of the molecular profile of this easily accessible ‘biopsy’ might be of prime importance for clinical practice in IBC patients. This review summarizes available data on feasibility and documented benefits of monitoring of essential IBC biological features in CTCs, with special reference to multifactorial proteomic, genomic, and transcriptomic panels of known prognostic or predictive value.

Factors Secreted by Cancer-Associated Fibroblasts that Sustain Cancer Stem Properties in Head and Neck Squamous Carcinoma Cells as Potential Therapeutic Targets

This study investigates for the first time the crosstalk between stromal fibroblasts and cancer stem cell (CSC) biology in head and neck squamous cell carcinomas (HNSCC), with the ultimate goal of identifying effective therapeutic targets. The effects of conditioned media from cancer-associated fibroblasts (CAFs) and normal fibroblasts (NFs) on the CSC phenotype were assessed by combining functional and expression analyses in HNSCC-derived cell lines. Further characterization of CAFs and NFs secretomes by mass spectrometry was followed by pharmacologic target inhibition. We demonstrate that factors secreted by CAFs but not NFs, in the absence of serum/supplements, robustly increased anchorage-independent growth, tumorsphere formation, and CSC-marker expression. Modulators of epidermal growth factor receptor (EGFR), insulin-like growth factor receptor (IGFR), and platelet-derived growth factor receptor (PDGFR) activity were identified as paracrine cytokines/factors differentially secreted between CAFs and NFs, in a mass spectrometry analysis. Furthermore, pharmacologic inhibition of EGFR, IGFR, and PDGFR significantly reduced CAF-induced tumorsphere formation and anchorage-independent growth suggesting a role of these receptor tyrosine kinases in sustaining the CSC phenotype. These findings provide novel insights into tumor stroma⁻CSC communication, and potential therapeutic targets to effectively block the CAF-enhanced CSC niche signaling circuit.

The role of PDGF-B/PDGFR-BETA axis in the normal development and carcinogenesis of the breast

PDGFs/PDGFRs axis is documented as an important tumor-promoting agent and potential therapeutic target for several human carcinomas, including breast cancer. However, little is known about the role played by the PDGF family members in the normal development of the breast tissue, breast carcinogenesis and tumor-microenvironment dynamics Despite its potent pro-lymphangiogenic effects, PDGF-B/PDGFR-beta axis remains controversial and incompletely elucidated in the field of breast cancer, with emphasis to its differential implications in breast cancer molecular subtypes. Although some data are available concerning this aspect, little or no information is found regarding the role of the PDGF-B/PDGFR-beta axis in rare and aggressive types of breast cancers, such as triple negative breast cancers (TNBCs) and its associated subtypes This review attempted to gather as many data as possible concerning PDGFs family members in the normal breast tissue and in breast carcinogenesis with special focus on their role in diagnosis and therapeutic approach.

MicroRNAs in regulation of triple-negative breast cancer progression

PURPOSE

Dysregulation of miRNA profile has been associated with a broad spectrum of cellular processes underlying progression of various human malignancies. Increasing evidence suggests that specific microRNA clusters might be of clinical utility, especially in triple-negative breast carcinoma (TNBC), devoid of both predictive markers and potential therapeutic targets. Here we provide a comprehensive review of the existing data on microRNAs in TNBC, their molecular targets, a putative role in invasive progression with a particular emphasis on the epithelial-to-mesenchymal transition (EMT) and acquisition of stem-cell properties (CSC), regarded both as prerequisites for metastasis, and significance for therapy.

METHODS

PubMed and Medline databases were systematically searched for the relevant literature. 121 articles have been selected and thoroughly analysed.

RESULTS

Several miRNAs associated with EMT/CSC and invasion were identified as significantly (1) upregulated: miR-10b, miR-21, miR-29, miR-9, miR-221/222, miR-373 or (2) downregulated: miR-145, miR-199a-5p, miR-200 family, miR-203, miR-205 in TNBC. Dysregulation of miR-10b, miR-21, miR-29, miR-145, miR-200 family, miR-203, miR-221/222 was reported of prognostic value in TNBC patients.

CONCLUSION

Available data suggest that specific microRNA clusters might play an important role in biology of TNBC, understanding of which should assist disease prognostication and therapy.

Epithelial-Mesenchymal Transition Markers in Breast Cancer and Pathological Responseafter Neoadjuvant Chemotherapy

The association between pathologic complete response (pCR) following to neoadjuvant chemotherapy (NAC) and the improved survival in breast cancer has been previously reported. The aim of this study was is to explore the expression of several biomarkers described during epithelial-mesenchymal transition (EMT) and the achievement of pCR in different molecular subtypes of breast cancer. We identified archived pathology tissue from patients with breast cancer who received NAC during the year 2014. We performed immunohistochemical analysis of vimentin, nuclear factor κB (NF-κB), epidermal growth factor receptor (EGFR), E-cadherin, estrogen receptor (ER), progesterone receptor, and Her2neu and studied the association between the expression of these markers and pCR. A Fisher exact test for categorical cofactors, an unpaired t test and a nonparametric Wilcoxon test for continuous cofactors were used. The results showed a significant expression of vimentin in triple-negative breast cancer (TNBC; P = .023). An inverse correlation between vimentin and the ER expression (P = .032) was observed. No significant association was noted for vimentin, NF-κB, EGFR, and E-cadherin was associated with pCR. This study suggests that the evaluated EMT related biomarkers are not associated with pCR after NAC chemotherapy in an unselected breast cancer population. Vimentin and NF-κB expressions were associated with TNBC and could be further explored as potential therapeutic targets in this subgroup. A prevalence of vimentin and NF-κB among Hispanic patients with breast cancer warrants further investigation as a possibly contributing to the prevalence of TNBC and adverse prognosis in this population.

Knockdown of B7H6 inhibits tumor progression in triple-negative breast cancer

The B7 family, the most common family of secondary signaling molecules, consists of eight cell-surface proteins, which regulate the T-cell mediated immune response by delivering co-inhibitory or co-stimulatory signals through their corresponding ligands. Among them, natural killer cell cytotoxicity receptor 3 ligand 1 (NCR3LG1, also known as B7H6) has been reported as a new member, and is involved in tumor progression of various types of human cancer. However, the role of B7H6 in triple-negative breast cancer (TNBC) remains unknown. In the present study, western blotting was performed to determine the protein expression levels of B7H6 in a normal mammary epithelial cell line (MCF-10A), non-TNBC breast cancer cell lines (MCF-7 and AU565) and TNBC cell lines (MDA-MB-231 and MDA-MB-468). B7H6 was knocked down using small interfering RNA, and an MTT assay was performed to determine proliferation ability, flow cytometry was used to analyze apoptosis, and Transwell and wound-healing assays were performed to measure migration ability. Expression of proliferation-associated proteins (SMAD family member 4 and β-catenin) and apoptosis-associated proteins (BCL2 associated X, BCL2 apoptosis regulator and caspase-3) were analyzed by western blotting. The results demonstrated that B7H6 was highly expressed in TNBC cells, and that knockdown of B7H6 inhibited cell proliferation and migration, and promoted apoptosis. Furthermore, the results revealed that proliferation and apoptosis-associated proteins were altered in the B7H6-knockdown MDA-MB-231 cells. In conclusion, the present study demonstrated that B7H6 may have significant roles in the regulation of cell proliferation, apoptosis and migration of TNBC cells.

Platelet-derived growth factor-D promotes colorectal cancer cell migration, invasion and proliferation by regulating Notch1 and matrix metalloproteinase-9

Colorectal cancer (CRC) has been one of the most common types of cancer for decades worldwide. The pathogenesis of CRC is associated with the processes of activating oncogenes and inactivating anti-oncogenes. Platelet-derived growth factor-D (PDGF-D) was confirmed to regulate migration, invasion, proliferation, apoptosis and metastasis in various cancer cells. Overexpression of PDGF-D exists in a number of human malignancies, including pancreatic, prostate and breast cancer. However, the expression and function of PDGF-D and its associated molecular mechanism in CRC remain unclear. Thus, the expression of PDGF-D was detected in CRC tissues and human colon cancer lines. Subsequently, the effects of PDGF-D on the invasion, migration and proliferation of cancer cells were investigated. The corresponding molecular mechanism had also been explored. The present study revealed that PDGF-D was upregulated not only in CRC tissues but also in CRC cell lines, and simultaneously, facilitated the processes of migration, invasion and proliferation. Silencing PDGF-D in the SW480 cell line inhibited migration, invasion and proliferation distinctly, with reduced expression of Notch1 and matrix metalloproteinase-9. Furthermore, upregulating PDGF-D in HCT116 cells led to the opposite results. These findings indicate that PDGF-D may be developed into a potential therapeutic target for CRC treatment.

Neutralization of IL-8 decreases tumor PMN-MDSCs and reduces mesenchymalization of claudin-low triple-negative breast cancer

The complex signaling networks of the tumor microenvironment that facilitate tumor growth and progression toward metastatic disease are becoming a focus of potential therapeutic options. The chemokine IL-8 is overexpressed in multiple cancer types, including triple-negative breast cancer (TNBC), where it promotes the acquisition of mesenchymal features, stemness, resistance to therapies, and the recruitment of immune-suppressive cells to the tumor site. The present study explores the utility of a clinical-stage monoclonal antibody that neutralizes IL-8 (HuMax-IL8) as a potential therapeutic option for TNBC. HuMax-IL8 was shown to revert mesenchymalization in claudin-low TNBC models both in vitro and in vivo as well as to significantly decrease the recruitment of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) at the tumor site, an effect substantiated when used in combination with docetaxel. In addition, HuMax-IL8 enhanced the susceptibility of claudin-low breast cancer cells to immune-mediated lysis with NK and antigen-specific T cells in vitro. These results demonstrate the multifaceted way in which neutralizing this single chemokine reverts mesenchymalization, decreases recruitment of MDSCs at the tumor site, assists in immune-mediated killing, and forms the rationale for using HuMax-IL8 in combination with chemotherapy or immune-based therapies for the treatment of TNBC.

EMT: Mechanisms and therapeutic implications

Metastasis, the dissemination of cancer cells from primary tumors, represents a major hurdle in the treatment of cancer. The epithelial-mesenchymal transition (EMT) has been studied in normal mammalian development for decades, and it has been proposed as a critical mechanism during cancer progression and metastasis. EMT is tightly regulated by several internal and external cues that orchestrate the shifting from an epithelial-like phenotype into a mesenchymal phenotype, relying on a delicate balance between these two stages to promote metastatic development. EMT is thought to be induced in a subset of metastatic cancer stem cells (MCSCs), bestowing this population with the ability to spread throughout the body and contributing to therapy resistance. The EMT pathway is of increasing interest as a novel therapeutic avenue in the treatment of cancer, and could be targeted to prevent tumor cell dissemination in early stage patients or to eradicate existing metastatic cells in advanced stages. In this review, we describe the sequence of events and defining mechanisms that take place during EMT, and how these interactions drive cancer cell progression into metastasis. We summarize clinical interventions focused on targeting various aspects of EMT and their contribution to preventing cancer dissemination.

Suppression of Spry1 inhibits triple-negative breast cancer malignancy by decreasing EGF/EGFR mediated mesenchymal phenotype

Sprouty (Spry) proteins have been implicated in cancer progression, but their role in triple-negative breast cancer (TNBC), a subtype of lethal and aggressive breast cancer, is unknown. Here, we reported that Spry1 is significantly expressed in TNBC specimen and MDA-MB-231 cells. To understand Spry1 regulation of signaling events controlling breast cancer phenotype, we used lentiviral delivery of human Spry1 shRNAs to suppress Spry1 expression in MDA-MB-231, an established TNBC cell line. Spry1 knockdown MDA-MB-231 cells displayed an epithelial phenotype with increased membrane E-cadherin expression. Knockdown of Spry1 impaired MDA-MB-231 cell migration, Matrigel invasion, and anchorage-dependent and -independent growth. Tumor xenografts originating from Spry1 knockdown MDA-MB-231 cells grew slower, had increased E-cadherin expression, and yielded fewer lung metastases compared to control. Furthermore, suppressing Spry1 in MDA-MB-231 cells impaired the induction of Snail and Slug expression by EGF, and this effect was associated with increased EGFR degradation and decreased EGFR/Grb2/Shp2/Gab1 signaling complex formation. The same phenotype was also observed in the TNBC cell line MDA-MB-157. Together, our results show that unlike in some tumors, where Spry may mediate tumor suppression, Spry1 plays a selective role in at least a subset of TNBC to promote the malignant phenotype via enhancing EGF-mediated mesenchymal phenotype.

Epithelial-Mesenchymal Transition and Breast Cancer

Breast cancer is the most common cancer in women and distant site metastasis is the main cause of death in breast cancer patients. There is increasing evidence supporting the role of epithelial-mesenchymal transition (EMT) in tumor cell progression, invasion, and metastasis. During the process of EMT, epithelial cancer cells acquire molecular alternations that facilitate the loss of epithelial features and gain of mesenchymal phenotype. Such transformation promotes cancer cell migration and invasion. Moreover, emerging evidence suggests that EMT is associated with the increased enrichment of cancer stem-like cells (CSCs) and these CSCs display mesenchymal characteristics that are resistant to chemotherapy and target therapy. However, the clinical relevance of EMT in human cancer is still under debate. This review will provide an overview of current evidence of EMT from studies using clinical human breast cancer tissues and its associated challenges.

The Interactions of Obesity, Inflammation and Insulin Resistance in Breast Cancer

Obese postmenopausal women have an increased breast cancer risk, the principal mechanism for which is elevated estrogen production by adipose tissue; also, regardless of menstrual status and tumor estrogen dependence, obesity is associated with biologically aggressive breast cancers. Type 2 diabetes has a complex relationship with breast cancer risk and outcome; coexisting obesity may be a major factor, but insulin itself induces adipose aromatase activity and estrogen production and also directly stimulates breast cancer cell growth and invasion. Adipose tissue inflammation occurs frequently in obesity and type 2 diabetes, and proinflammatory cytokines and prostaglandin E2 produced by cyclooxygenase-2 in the associated infiltrating macrophages also induce elevated aromatase expression. In animal models, the same proinflammatory mediators, and the chemokine monocyte chemoattractant protein-1, also stimulate tumor cell proliferation and invasion directly and promote tumor-related angiogenesis. We postulate that chronic adipose tissue inflammation, rather than body mass index-defined obesity per se, is associated with an increased risk of type 2 diabetes and postmenopausal estrogen-dependent breast cancer. Also, notably before the menopause, obesity and type 2 diabetes, or perhaps the associated inflammation, promote estrogen-independent, notably triple-negative, breast cancer development, invasion and metastasis by mechanisms that may involve macrophage-secreted cytokines, adipokines and insulin.

Epigenetic changes and nuclear factor-κB activation, but not microRNA-224, downregulate Raf-1 kinase inhibitor protein in triple-negative breast cancer SUM 159 cells

Raf-1 kinase inhibitor protein (RKIP) is a tumor suppressor and metastasis inhibitor, which enhances drug-induced apoptosis of cancer cells. Downregulation of RKIP may be significant in the biology of highly aggressive and drug-resistant tumors, for example triple-negative breast cancers (TNBCs). Potential causes for the low levels of RKIP expressed by SUM 159 TNBC cells were investigated in the present study. Bisulphite modification, methylation specific-polymerase chain reaction (PCR) and a TransAM NF-κB assay were performed and the results suggested that various mechanisms, including methylation of the gene promoter, histone deacetylation and nuclear factor-κB (NF-κB) activation, but not targeting by microRNA-224 (miR/miRNA-224), as determined by transfection of pre-miR-224 miRNA precursor or anti-miR-224 miRNA inhibitor, may downregulate RKIP in these cells. Furthermore, reverse transcription-quantitative PCR, western blotting, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium cell growth assay and flow cytometry revealed that in SUM 159 cells, the demethylating agent 5-aza-2'-deoxycytidine (5-AZA), the histone deacetylase inhibitor trichostatin A (TSA) and the NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) enhanced RKIP expression and resulted in significant cell growth inhibition and induction of apoptosis. 5-AZA and TSA mainly produced additive antitumor effects, while the combination of DHMEQ and TSA exhibited significant synergy in cell growth inhibition and induction of apoptosis assays. Increasing evidence that aberrant activation of NF-κB signaling is a frequent characteristic of TNBC highlights the fact that this transcription factor may be a useful target for treatment of such tumors. In addition to DHMEQ, proteasome inhibitors may also represent valuable therapeutic resources in this context. Notably, proteasome inhibitors, in addition to the inhibition of NF-κB activation, may also restore RKIP levels by inhibiting proteasome degradation of the ubiquitinated protein. The current results contribute to the understanding of the molecular mechanisms of RKIP downregulation in TNBC and suggest possible novel therapeutic approaches for the treatment of these types of cancer.

[Role of cadherins in health and in developing breast cancer]

The review gives data on the structure of cadherin cell adhesion molecules, their role in the body's development and malignant tumor progression. It describes cadherins that are considered to play the most important role in the development of a tumor process: E-, P-, and N-cadherins that belong to type I classical cadhedrins and VE-cadhedrin that does to type II cadherins. Particular emphasis is placed on the signal mechanisms with involvement of cadherins and cadherin-related molecules, which are realized in the body in health and in tumor transformation of cells.

Soluble factors regulated by epithelial-mesenchymal transition mediate tumour angiogenesis and myeloid cell recruitment

Epithelial-mesenchymal transition (EMT) programmes provide cancer cells with invasive and survival capacities that might favour metastatic dissemination. Whilst signalling cascades triggering EMT have been extensively studied, the impact of EMT on the crosstalk between tumour cells and the tumour microenvironment remains elusive. We aimed to identify EMT-regulated soluble factors that facilitate the recruitment of host cells in the tumour. Our findings indicate that EMT phenotypes relate to the induction of a panel of secreted mediators, namely IL-8, IL-6, sICAM-1, PAI-1 and GM-CSF, and implicate the EMT-transcription factor Snail as a regulator of this process. We further show that EMT-derived soluble factors are pro-angiogenic in vivo (in the mouse ear sponge assay), ex vivo (in the rat aortic ring assay) and in vitro (in a chemotaxis assay). Additionally, conditioned medium from EMT-positive cells stimulates the recruitment of myeloid cells. In a bank of 40 triple-negative breast cancers, tumours presenting features of EMT were significantly more angiogenic and infiltrated by a higher quantity of myeloid cells compared to tumours with little or no EMT. Taken together, our results show that EMT programmes trigger the expression of soluble mediators in cancer cells that stimulate angiogenesis and recruit myeloid cells in vivo, which might in turn favour cancer spread.

Novel strategies targeting cancer stem cells through phytochemicals and their analogs

Cancer stem cells (CSCs) are cells that exist within a tumor with a capacity of self-renewal and an ability to differentiate, giving rise to heterogeneous populations of cancer cells. These cells are increasingly being implicated in resistance to conventional therapeutics and have also been implicated in tumor recurrence. Several cellular signaling pathways including Notch, Wnt, phosphoinositide-3-kinase-Akt-mammalian target of rapamycin pathways, and known markers such as CD44, CD133, CD166, ALDH, etc. have been associated with CSCs. Here, we have reviewed our current understanding of self-renewal pathways and factors that help in the survival of CSCs with special emphasis on those that have been documented to be modulated by well characterized natural agents such as curcumin, sulforaphane, resveratrol, genistein, and epigallocatechin gallate. With the inclusion of a novel derivative of curcumin, CDF, we showcase how natural agents can be effectively modified to increase their efficacy, particularly against CSCs. We hope that this article will generate interest among researchers for further mechanistic and clinical studies exploiting the cancer preventive and therapeutic role of nutraceuticals by targeted elimination of CSCs.

Triple negative breast cancer

Triple-negative breast cancers (TNBC), characterized by absence of the estrogen receptor (ER) and progesterone receptor (PR) and lack of overexpression of human epidermal growth factor receptor 2 (HER2), have a poor prognosis. To overcome therapy limitations of TNBC, various new approaches are needed. This mini-review focuses on discovery of new targets and drugs which might offer new hope for TNBC patients.

n-3 polyunsaturated fatty acids and mechanisms to mitigate inflammatory paracrine signaling in obesity-associated breast cancer

Globally, the prevalence of obesity is increasing which subsequently increases the risk of the development of obesity-related chronic diseases. Low-grade chronic inflammation and dysregulated adipose tissue inflammatory mediator/adipokine secretion are well-established in obesity, and these factors increase the risk of developing inflammation-associated cancer. Breast cancer is of particular interest given that increased inflammation within the subcutaneous mammary adipose tissue depot can alter the local tissue inflammatory microenvironment such that it resembles that of obese visceral adipose tissue. Therefore, in obese women with breast cancer, increased inflammatory mediators both locally and systemically can perpetuate inflammation-associated pro-carcinogenic signaling pathways, thereby increasing disease severity. Herein, we discuss some of these inflammation-associated pro-carcinogenic mechanisms of the combined obese breast cancer phenotype and offer evidence that dietary long chain n-3 polyunsaturated fatty acids (PUFA) may have utility in mitigating the severity of obesity-associated inflammation and breast cancer.

Protein kinase D1 regulates ERα-positive breast cancer cell growth response to 17β-estradiol and contributes to poor prognosis in patients

About 70% of human breast cancers express and are dependent for growth on estrogen receptor α (ERα), and therefore are sensitive to antiestrogen therapies. However, progression to an advanced, more aggressive phenotype is associated with acquisition of resistance to antiestrogens and/or invasive potential. In this study, we highlight the role of the serine/threonine-protein kinase D1 (PKD1) in ERα-positive breast cancers. Growth of ERα-positive MCF-7 and MDA-MB-415 human breast cancer cells was assayed in adherent or anchorage-independent conditions in cells overexpressing or depleted for PKD1. PKD1 induces cell growth through both an ERα-dependent manner, by increasing ERα expression and cell sensitivity to 17β-estradiol, and an ERα-independent manner, by reducing cell dependence to estrogens and conferring partial resistance to antiestrogen ICI 182,780. PKD1 knockdown in MDA-MB-415 cells strongly reduced estrogen-dependent and independent invasion. Quantification of PKD1 mRNA levels in 38 cancerous and non-cancerous breast cell lines and in 152 ERα-positive breast tumours from patients treated with adjuvant tamoxifen showed an association between PKD1 and ERα expression in 76.3% (29/38) of the breast cell lines tested and a strong correlation between PKD1 expression and invasiveness (P < 0.0001). In tamoxifen-treated patients, tumours with high PKD1 mRNA levels (n = 77, 50.66%) were significantly associated with less metastasis-free survival than tumours with low PKD1 mRNA expression (n = 75, 49.34%; P = 0.031). Moreover, PKD1 mRNA levels are strongly positively associated with EGFR and vimentin levels (P < 0.0000001). Thus, our study defines PKD1 as a novel attractive prognostic factor and a potential therapeutic target in breast cancer.

Up-regulation of microRNA-10b is associated with the development of breast cancer brain metastasis

Brain metastases from primary breast cancer are difficult to treat and associated with poor prognosis. Our understanding of the molecular basis for the development of such cancers is sparse. We hypothesized that the pro-metastatic microRNA-10b (miR-10b) plays a role in breast cancer brain metastasis. The study cohort comprised of twenty patients with breast cancer and brain metastasis as well as ten control patients (age, stage, and follow-up matched) with breast cancer without brain metastasis. All cases were microscopically reviewed to select tumor blocks with >50% tumor cells. RNA was extracted from formalin fixed paraffin embedded (FFPE) tumor tissue blocks. Expression of miR-10b was analyzed using qRT-PCR. The relevance of miR-10b expression was also tested using human breast cancer cell lines. An increased expression of miR-10b was noted in the primary breast cancer specimens of patients who subsequently developed brain metastasis, compared to those who did not. miR-10b also increased the invasive potential of breast cancer cells in vitro. Wilcoxon signed rank test revealed a statistically significant difference between the paired tumors from breast cancers and brain metastasis (p <0.001). Increased expression of miR-10b appears to be associated with breast cancer brain metastasis. These findings are clinically relevant since miR-10b could serve as a prognostic and/or therapeutic target for anti-metastatic therapy. Identifying molecular signatures of primary breast cancers which have a propensity for brain metastasis is critical for designing novel therapies to counter the development of brain metastasis in patients diagnosed with breast cancer.

Association of TRPS1 gene with different EMT markers in ERα-positive and ERα-negative breast cancer

Background

Breast cancer is a heterogeneous disease consisting of different subtypes. Trichorhinophalangeal syndrome type 1 (TRPS1) gene, a GATA-type transcription factor, has been found to be highly expressed in breast cancer. Epithelial-to-mesenchymal transition (EMT) is known to play an important role in tumour invasion and metastasis. Our objective was to elucidate the different roles and clinical relevance of TRPS1 in different estrogen receptor (ER) expression subtypes of breast cancer.

Methods

An immunohistochemical study was performed. The correlation between clinicopathological features and other biomarker profiles were analysed statistically.

Result

TRPS1 expression was correlated with the patients’ age (P = 0.017). It was positively related with ERα (P < 0.001), progesterone receptor (PR) (P < 0.001) and ERβ (P = 0.001) status, but negatively associated with Ki67 (P = 0.002) and HER2 (P = 0.025) status. In ERα-positive breast cancer, TRPS1 expression was positively associated with the expression of E-cadherin (P < 0.001), β-catenin(P = 0.001), ERβ (P = 0.03), and p53 (P = 0.002) status, while in ERα-negative breast cancer, TRPS1 expression was correlated with slug (P = 0.004), vimentin (P = 0.003), smooth muscle actin (SMA) (P = 0.031), and IMP3 (P = 0.005) expression.

Conclusions

Based on our findings, we conclude that TRPS1 is positively associated with E-cadherin and β-catenin status in ERα-positive breast cancer cells, while it is also significantly associated with mesenchymal markers of EMT in ERα-negative breast cancer cells. TRPS1 can be a prognostic marker depending on the type of breast cancer.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8686515681264281

The therapeutic potential of targeting the epithelial-mesenchymal transition in cancer

INTRODUCTION

The process of epithelial-to-mesenchymal transition (EMT) has long been advocated as a process during tumor progression and the acquisition of metastatic potential of human cancers. EMT has also been linked with resistance to cancer therapies.

AREAS COVERED

Basic research has provided evidence connecting EMT to increased invasion, angiogenesis and metastasis of cancer cells. A number of signaling pathways such as notch, wnt, hedgehog and PI3K-AKT, and various other individual factors therein, have been intricately connected to the onset of EMT. Here, we provide latest updates on the evidences that further highlight an association between various signaling pathways and EMT, with a focus on therapeutic targets that may have the potential to reverse EMT.

EXPERT OPINION

Our understanding of EMT and its underlying causes is rapidly evolving and a number of putative targets have been identified. It is crucial, now than ever before, to design novel translational and clinical studies for the benefit of advanced stage cancer patients with metastatic disease.

Biochemical and molecular mechanisms for the association between obesity, chronic inflammation, and breast cancer

Upper body obesity is a risk factor for postmenopausal breast cancer and is related to an aggressive tumor phenotype and a poor prognosis regardless of menopausal status. After the menopause, the major mechanism for the association with disease risk is elevated estrogen production by adipose tissue, due to a high level of aromatase activity: these hormone-dependent tumors express both estrogen and progesterone receptors. Other important biological factors of risk include leptin and adiponectin, adipokines with opposing endocrine and paracrine activities, and obesity-related hyperinsulinemia. Chronic inflammation of the breast adipose tissue, which occurs in some obese women and is indicated by the accumulation of macrophages around dead adipocytes ("crown-like structures"), rather than adiposity per se, may prove to be the pathological lesion responsible for both local aromatase induction, and enhanced invasiveness and metastatic capacity through biological mechanisms that involve leptin, tumor necrosis factor-α, and insulin. A causal association between obesity in premenopausal women and breast cell epithelial-mesenchymal transition, perhaps with the participation of the Wnt signaling pathway, and aggressive hormone-independent breast cancer is suggested by a number of experimental and clinical studies.

The obesity-inflammation-eicosanoid axis in breast cancer

Inflammation of the adipose tissues occurs in association with obesity. This inflammatory process leads to the induction of cyclooxygenase-2 (COX-2) expression and a consequent elevation in prostaglandin (PG) production, which, together with proinflammatory cytokines, induce aromatase expression and estrogen synthesis. Infiltrating macrophages support the growth of breast epithelial cells and vascular endothelial cells by producing a milieu of cytokines and growth factors. This scenario creates a microenvironment favorable to breast cancer growth and invasion. The eicosanoids promote further development and growth of breast cancers indirectly by the induction of aromatase, particularly in estrogen positive breast cancers, or by direct stimulatory effect of PGE2 and lipoxygenase (LOX) products on the more aggressive, estrogen-independent tumors. Beyond this, the local production of estrogens and proinflammatory cytokines which occurs in association with breast adipose tissue inflammation, and consequent activation of the estrogen receptor and nuclear factor-κB, provides a mechanism by which breast cancers develop resistance to selective estrogen receptor modulation and aromatase inhibitor therapy. The obesity-inflammation-eicosanoid axis in breast cancer does offer a therapeutic target for the prevention of relapse in breast cancer by improving the efficacy of antiaromatase therapy using COX/LOX inhibitors; however, careful consideration of menopausal status and obesity in patients is warranted.

Role of fucosyltransferase IV in epithelial-mesenchymal transition in breast cancer cells

Epithelial–mesenchymal transition (EMT) is a crucial step in tumor progression and has an important role during cancer invasion and metastasis. Although fucosyltransferase IV (FUT4) has been implicated in the modulation of cell migration, invasion and cancer metastasis, its role during EMT is unclear. This study explores the molecular mechanisms of the involvement of FUT4 in EMT in breast cancer cells. Breast cancer cell lines display increased expression of FUT4, which is accompanied by enhanced appearance of the mesenchymal phenotype and which can be reversed by knockdown of endogenous FUT4. Moreover, FUT4 induced activation of phosphatidylinositol 3-kinase (PI3K)/Akt, and inactivation of GSK3β and nuclear translocation of NF-κB, resulting in increased Snail and MMP-9 expression and greater cell motility. Taken together, these findings indicate that FUT4 has a role in EMT through activation of the PI3K/Akt and NF-κB signaling systems, which induce the key mediators Snail and MMP-9 and facilitate the acquisition of a mesenchymal phenotype. Our findings support the possibility that FUT4 is a novel regulator of EMT in breast cancer cells and a promising target for cancer therapy.

Clinical advances in molecular biomarkers for cancer diagnosis and therapy

Cancer diagnosis is currently undergoing a paradigm shift with the incorporation of molecular biomarkers as part of routine diagnostic panel. The molecular alteration ranges from those involving the DNA, RNA, microRNAs (miRNAs) and proteins. The miRNAs are recently discovered small non-coding endogenous single-stranded RNAs that critically regulates the development, invasion and metastasis of cancers. They are altered in cancers and have the potential to serve as diagnostic markers for cancer. Moreover, deregulating their activity offers novel cancer therapeutic approaches. The availability of high throughput techniques for the identification of altered cellular molecules allowed their use in cancer diagnosis. Their application to a variety of body specimens from blood to tissues has been helpful for appreciating their use in the clinical context. The development of innovative antibodies for immunohistochemical detection of proteins also assists in diagnosis and risk stratification. Overall, the novel cancer diagnostic tools have extended their application as prognostic risk factors and can be used as targets for personalized medicine.

Expression of Smad7 in cholangiocarcinoma: prognostic significance and implications for tumor metastasis

BACKGROUND

There are few molecular markers known to predict cholangiocarcinoma (CCA) prognosis. Smad7 has a certain relationship with epithelial-mesenchymal transition (EMT), but its relevance to CCA in unclear. Therefore expression and clinical significance of Smad7 in CCA was the focus of this study.

METHODS

Expression of Smad7, E-cadherin and vimentin was assessed in 41 patients with CCA by immunohistochemistry and analyzed for associations with clinical parameters.

RESULTS

Smad7 and vimentin expression in the CCA tissue was dramatically higher than that in adjacent tissues. In addition, Smad7, vimentin and E-cadherin expression was significantly associated with CCA lymph node metastasis and perineural invasion(P ≤ 0.05), but not other factors, such as gender, age, tumor location, tumor type and tumor differentiation degree (P>0.05). The overall survival and relapse-free survival rate was significantly higher in patients with negative Smad7 expression than those with positive Smad7 expression.

CONCLUSION

EMT phenomena may occur in the process of CCA invasion and metastasis. Smad7, which was highly expressed in CCA, may be considered to be one feedback regulator in late stages and could have potential as a prognostic indicator for clinical assessment.

Characteristics of cross-hybridization and cross-alignment of expression in pseudo-xenograft samples by RNA-Seq and microarrays

Background

Exploring stromal changes associated with tumor growth and development is a growing area of oncologic research. In order to study molecular changes in the stroma it is recommended to separate tumor tissue from stromal tissue. This is relevant to xenograft models where tumors can be small and difficult to separate from host tissue. We introduce a novel definition of cross-alignment/cross-hybridization to compare qualitatively the ability of high-throughput mRNA sequencing, RNA-Seq, and microarrays to detect tumor and stromal expression from mixed ‘pseudo-xenograft’ samples vis-à-vis genes and pathways in cross-alignment (RNA-Seq) and cross-hybridization (microarrays). Samples consisted of normal mouse lung and human breast cancer cells; these were combined in fixed proportions to create a titration series of 25% steps. Our definition identifies genes in a given species (human or mouse) with undetectable expression in same-species RNA but detectable expression in cross-species RNA. We demonstrate the comparative value of this method and discuss its potential contribution in cancer research.

Results

Our method can identify genes from either species that demonstrate cross-hybridization and/or cross-alignment properties. Surprisingly, the set of genes identified using a simpler and more common approach (using a ‘pure’ cross-species sample and calling all detected genes as ‘crossers’) is not a superset of the genes identified using our technique. The observed levels of cross-hybridization are relatively low: 5.3% of human genes detected in mouse, and 3.5% of mouse genes detected in human. Observed levels of cross-alignment are practically comparable to the levels of cross-hybridization: 6.5% of human genes detected in mouse, and 2.3% of mouse genes detected in human. We also observed a relatively high percentage of orthologs: 40.3% of cross-hybridizing genes, and 32.2% of cross-aligning genes.

Normalizing the gene catalog to use Consensus Coding Sequence (CCDS) IDs (Genome Res 19:1316–1323, 2009), our results show that the observed levels of cross-hybridization are low: 2.7% of human CCDS IDs are detected in mouse, and 2.4% of mouse CCDS IDs are detected in human. Levels of cross-alignment using the RNA-Seq data are comparable for the mouse, 2.2% of mouse CCDS IDs detected in human, and 9.9% of human CCDS IDs detected in mouse. However, the lists of cross-aligning/cross-hybridizing genes contain many that are of specific interest to oncologic researchers.

Conclusions

The conservative definition that we propose identifies genes in mouse whose expression can be attributed to human RNA, and vice versa, as well as revealing genes with cross-alignment/cross-hybridization properties which could not be identified using a simpler but more established approach. The overall percentage of genes affected by cross-hybridization/cross-alignment is small, but includes genes that are of interest to oncologic researchers. Which platform to use with mixed xenograft samples, microarrays or RNA-Seq, appears to be primarily a question of cost and whether the detection and measurement of expression of specific genes of interest are likely to be affected by cross-hybridization or cross-alignment.

Activated K-Ras and INK4a/Arf deficiency promote aggressiveness of pancreatic cancer by induction of EMT consistent with cancer stem cell phenotype

Pancreatic ductal adenocarcinoma (PDAC) is one of the most frequently diagnosed cancers and the fourth leading cause of cancer-related death in the United States, suggesting that there is an urgent need to design novel strategies for achieving better treatment outcome of patients diagnosed with PDAC. Our previous study has shown that activation of Notch and NF-κB play a critical role in the development of PDAC in the compound K-Ras(G12D) and Ink4a/Arf deficient transgenic mice. However, the exact molecular mechanism by which mutated K-Ras and Ink4a/Arf deficiency contribute to progression of PDAC remains largely elusive. In the present study, we used multiple methods, such as real-time RT-PCR, Western blotting assay, and immunohistochemistry to gain further mechanistic insight. We found that the deletion of Ink4a/Arf in K-Ras(G12D) expressing mice led to high expression of PDGF-D signaling pathway in the tumor and tumor-derived cell line (RInk-1 cells). Furthermore, PDGF-D knock-down in RInk-1 cells resulted in the inhibition of pancreatosphere formation and down-regulation of EZH2, CD44, EpCAM, and vimentin. Moreover, we demonstrated that epithelial-mesenchymal transition (EMT) was induced in the compound mice, which is linked with aggressiveness of PDAC. In addition, we demonstrated that tumors from compound transgenic mice have higher expression of cancer stem cell (CSC) markers. These results suggest that the acquisition of EMT phenotype and induction of CSC characteristics could be linked with the aggressiveness of PDAC mediated in part through the activation of PDGF-D, signaling.

Suppression of HER-2 via siRNA interference promotes apoptosis and decreases metastatic potential of SKOV‑3 human ovarian carcinoma cells

The aberrant expression of human epidermal growth factor receptor-2 (HER-2) has been detected in ovarian cancer. However, the role of HER-2 in the development of ovarian cancer has not been sufficiently elucidated. The objective of this study was to determine the role of HER-2 in the apoptosis and metastasis of SKOV-3 ovarian cancer cells. SKOV-3 cells were transfected with three double‑stranded small interfering RNA (siRNA) molecules that target HER-2. Various sequences were synthesized by T7 transcription in vitro to select the most effective HER-2‑silencing siRNA. SKOV-3 cells were examined for growth inhibition using the MTT proliferation assay and apoptosis was assessed using flow cytometry and TUNEL assay. The Matrigel basement memebrane matrix was used to assess invasion and chemotactic mobility, as a model of tumor cell metastasis. Western blot analysis was used to detect the expression of matrix metallopeptidase-9 (MMP-9), E-cadherin, N-cadherin and vimentin. siRNA interference in HER-2 resulted in decreased cell proliferation and invasion and increased apoptosis. Western blot analysis demonstrated a marked increase in E-cadherin and MMP-9 and a reduction in N-cadherin and vimentin protein levels in the SKOV-3 cells. The suppression of HER-2 expression resulted in apoptosis and the inhibition of metastasis of SKOV-3 cells. Therefore, the overexpression of the HER-2 gene can enhance the metastatic potential of SKOV-3 cells by increasing the protein levels of MMP-9. Epithelial-mesenchymal transition may be involved in the HER-2 siRNA-induced invasion and migration of SKOV-3 cells. Taken together, these results suggest that HER-2 functions as an oncogene and may thus be an attractive therapeutic target in SKOV-3 ovarian cancer cells.

Emerging roles of PDGF-D in EMT progression during tumorigenesis

Platelet-derived growth factor-D (PDGF-D) signaling pathway has been reported to be involved in regulating various cellular processes, such as cell growth, apoptotic cell death, migration, invasion, angiogenesis and metastasis. Recently, multiple studies have shown that PDGF-D plays a critical role in governing epithelial-to-mesenchymal transition (EMT), although the underlying mechanism of PDGF-D-mediated acquisition of EMT is largely unclear. Therefore, this mini review will discuss recent advances in our understanding of the role of PDGF-D in the acquisition of EMT during tumorigenesis. Furthermore, we will summarize the function of chemical inhibitors and natural compounds that are known to inactivate PDGF-D signaling pathway, which leads to the reversal of EMT. In summary, inactivation of PDGF-D could be a novel strategy for achieving better treatment outcome of patients inflicted with cancers.

Epithelial mesenchymal transition in colorectal cancer: Seminal role in promoting disease progression and resistance to neoadjuvant therapy

BACKGROUND

Epithelial mesenchymal transition (EMT) may be physiological as part of embryological development, or pathological as part of cancer development. It is one of the key initiating events in the metastatic cascade. EMT has profound effects on tumour cell invasiveness, proliferation and motility. In the present article we aimed to review the potential role of EMT as a process to explain colorectal cancer progression and resistance to neoadjuvant therapy.

METHODS

Extensive literature searches were performed in Pubmed, EMBASE and Google Scholar databases to identify relevant articles published before March 2012.

RESULTS

There is adequate evidence to support the complex upstream signalling alterations needed for EMT to occur in colorectal cancers. Changes of EMT are likely to be found at the tumour invasive front: the deepest, growing tumour margin. Loss of E-cadherin at the cell membrane causes loss of cellular integrity, with subsequent migration of malignant cells and tumour budding. These processes are associated with metastases and recurrence of colorectal cancer. There is early evidence from a limited number of studies that resistance to neoadjuvant therapy in colorectal cancer is associated with changes of EMT. However, there is a lack of supporting evidence originating from human colorectal cancer tissues.

CONCLUSIONS

Emerging evidence demonstrates that development of EMT in colorectal cancer leads to an aggressive phenotype that may promote metastatic spread, and augment treatment resistance during neoadjuvant therapy. A clearer understanding of the processes and role of EMT in colorectal cancer may also highlight novel therapeutic strategies.

Migration of cells from experimental endometriosis to the uterine endometrium

Endometriosis is the estrogen-dependent growth of endometrial tissue outside the uterus. Endometriosis has an effect on the eutopic endometrium; however, the nature of the cellular or molecular signal from the lesion to the uterus is unknown. Here we demonstrate that cells migrate from endometriosis to eutopic endometrium. Experimental endometriosis was established by transplanting endometrial tissue from green fluorescent protein (GFP) mice to the peritoneal cavity of DS-Red mice. Immunofluorescence (IF) identified cells from the ectopic lesions in the uterus. The eutopic endometrial cells were sorted by fluorescence activated cell sorting, and the GFP(+)/DS-Red(-) population was characterized using microarray analysis. The results of cell sorting as well as the array results were confirmed by quantitative PCR and IF. GFP(+)/DS-red(-)/Cd45(-) cells were identified in the eutopic endometrium of mice with experimental endometriois (∼1.8%) and not in controls. Global gene expression profiling of these cells showed absence of leukocyte and increased expression of pan-epithelial markers in the uterine GFP(+) cells. Moreover, GFP(+) cells showed up-regulation of Wnt7A expression and 17 other genes associated with the Wingless pathway. Several genes that are associated with epithelial-to-mesenchymal transition were also highly differentially expressed in GFP(+) cells. IF confirmed the presence of the GFP(+)/CD45(-)/Wnt7a(+)/cytokeritin(+) cells in the endometrium of endometriotic animals, and not in controls. Cells from endometriotic lesions are capable of migrating to the eutopic endometrium. The ectopic expression of Wnt7A suggests a possible mechanism by which ectopic lesions affect the eutopic endometrium and interfere with embryo implantation and fertility.

Selection of a MCF-7 Breast Cancer Cell Subpopulation with High Sensitivity to IL-1β: Characterization of and Correlation between Morphological and Molecular Changes Leading to Increased Invasiveness

Cancer and inflammation are closely related in tumor malignancy prognosis. Breast cancer MCF-7 cells have a poor invasive phenotype, although, under IL-1β stimulus, acquire invasive features. Cell response heterogeneity has precluded precise evaluation of the malignant transition. MCF-7A3 cells were selected for high sensitivity to IL-1β stimulus, uniform expression of CXCR4, and stability of IL1-RI. Structural changes, colony formation ability, proliferation rate, chemotaxis, Matrigel invasion, E-cadherin mRNA expression and protein localization were determined in these cells and in MCF-7 parental cells under the stimulus of IL-1β. Selected MCF-7A3 cells showed a uniform response to IL-1β stimulation increasing features of invasive cells such as scattering, colony formation, proliferation, chemokinesis and invasion. Basal expression of E-cadherin mRNA was higher, and IL-1β stimulus had no further effect at early times of cytokine exposure. Total E-cadherin levels remained unchanged in parental cells, whereas levels decreased, as MCF-7A3 cells became fibroblastoid or scattered. Triton X-100 soluble/insoluble E-cadherin ratios were highly increased in these cells, while, in MCF-7pl cells, ratios could not be correlated with morphology changes. MCF-7A3 cells uniform response to IL-1β allowed characterization of changes induced by the cytokine that had not been assessed when using heterogeneous cell lines.