Molecular mechanisms controlling E-cadherin expression in breast cancer

Benzo[a]pyrene promotes an epithelial-to-mesenchymal transition process in MCF10A cells and mammary tumor growth and brain metastasis in female mice

Breast cancer is the most frequent neoplasia in developed countries and the leading cause of death in women worldwide. Epithelial-to-mesenchymal transition (EMT) is a cellular process through which epithelial cells decrease or lose their epithelial characteristics and gain mesenchymal properties. EMT mediates tumor progression, because tumor cells acquire the capacity to execute the multiple steps of invasion and metastasis. Benzo[a]pyrene (B[a]P) is an environmental organic pollutant generated during the burning of fossil fuels, wood, and other organic materials. B[a]P exposition increases the incidence of breast cancer, and induces migration and/or invasion in MDA-MB-231 and MCF-7 breast cancer cells. However, the role of B[a]P in the induction of an EMT process and metastasis of mammary carcinoma cells has not been studied in detail. In this study, we demonstrate that B[a]P induces an EMT process in MCF10A mammary non-tumorigenic epithelial cells. In addition, B[a]P promotes the formation of larger tumors in Balb/cJ mice inoculated with 4T1 cells than in untreated mice and treated with dimethyl sulfoxide (DMSO). B[a]P also increases the number of mice with metastasis to brain and the total number of brain metastatic nodules in Balb/cJ mice inoculated with 4T1 cells compared with untreated mice and treated with DMSO. In conclusion, B[a]P induces an EMT process in MCF10A cells and the growth of mammary tumors and metastasis to brain in Balb/cJ mice inoculated with 4T1 cells.

Evaluating Recurrence Risk in Patients Undergoing Breast-conserving Surgery Using E-cadherin Staining as a Biomarker

BACKGROUND/AIM

Following the National Comprehensive Cancer Network guidelines, radiotherapy is administered after breast-conserving surgery (BCS) in patients with more than four positive lymph nodes. Four positive lymph nodes are typically considered an indicator to assess disease spread and patient prognosis. However, the subjective counting of positive axillary lymph nodes underscores the need for biomarkers to improve diagnostic precision and reduce the risk of unnecessary treatments. Loss of E-cadherin expression is associated with cancer metastasis, but its potential as a predictive marker for cancer treatment remains uncertain. This study aimed to investigate the validity of E-cadherin as a reference for adjuvant radiotherapy in breast cancer patients with positive lymph nodes post-mastectomy.

MATERIALS AND METHODS

Immunohistochemistry was performed on 60 clinical tissue specimens to assess these implications.

RESULTS

Although no significant result was found in a single E-cadherin subgroup (low, medium, and high subgroups according to the X-tile algorithm), the proposed multivariate model, including the E-cadherin category, breast cancer subtype, and tumor size, yielded satisfactory recurrence risk estimation results for patients undergoing BCS. Patients with a low E-cadherin category, triple-negative breast cancers, and tumor size over 5 cm could have an increased risk of recurrence.

CONCLUSION

Our study proposed a multivariate model that serves as a candidate prognostic factor for recurrence-free survival in patients undergoing BCS and radiotherapy. Utilizing this model for patient stratification in high-risk diseases and as a standard for assessing postoperative intensified therapy can potentially improve patient outcomes.

Dynamic interplay of nuclear receptors in tumor cell plasticity and drug resistance: Shifting gears in malignant transformations and applications in cancer therapeutics

Recent advances have brought forth the complex interplay between tumor cell plasticity and its consequential impact on drug resistance and tumor recurrence, both of which are critical determinants of neoplastic progression and therapeutic efficacy. Various forms of tumor cell plasticity, instrumental in facilitating neoplastic cells to develop drug resistance, include epithelial-mesenchymal transition (EMT) alternatively termed epithelial-mesenchymal plasticity, the acquisition of cancer stem cell (CSC) attributes, and transdifferentiation into diverse cell lineages. Nuclear receptors (NRs) are a superfamily of transcription factors (TFs) that play an essential role in regulating a multitude of cellular processes, including cell proliferation, differentiation, and apoptosis. NRs have been implicated to play a critical role in modulating gene expression associated with tumor cell plasticity and drug resistance. This review aims to provide a comprehensive overview of the current understanding of how NRs regulate these key aspects of cancer biology. We discuss the diverse mechanisms through which NRs influence tumor cell plasticity, including EMT, stemness, and metastasis. Further, we explore the intricate relationship between NRs and drug resistance, highlighting the impact of NR signaling on chemotherapy, radiotherapy and targeted therapies. We also discuss the emerging therapeutic strategies targeting NRs to overcome tumor cell plasticity and drug resistance. This review also provides valuable insights into the current clinical trials that involve agonists or antagonists of NRs modulating various aspects of tumor cell plasticity, thereby delineating the potential of NRs as therapeutic targets for improved cancer treatment outcomes.

Clinical importance of serum miRNA levels in breast cancer patients

There is limited data on the relationship of miRNAs with parameters that may affect surgical management or reflect tumour prognosis. It was aimed to evaluate serum miRNA levels in breast carcinoma cases and reveal the relationship between these levels and prognosis-related factors such as the histological type of the tumour, estrogen receptor, progesterone receptor, Ki-67 index, HER-2neu, E-cadherin, tumour size, CK5/6, CA15.3 levels, number of tumour foci, number of metastatic lymph nodes, and status of receiving neoadjuvant therapy. Thirty-five patients with a histopathologically confirmed breast carcinoma diagnosis in the case group and 35 healthy individuals in the control group were examined. miR-206, miR-17-5p, miR-125a, miR-125b, miR-200a, Let-7a, miR-34a, miR-31, miR-21, miR-155, miR-10b, miR-373, miR-520c, miR-210, miR-145, miR-139-5p, miR-195, miR-99a, miR-497 and miR-205 expression levels in the serum of participants were determined using the Polymerase Chain Reaction method. While serum miR-125b and Let-7a expression levels were significantly higher in breast cancer patients, miR-17-5p, miR-125a, miR-200a, miR-34a, miR-21, miR-99a and miR-497 levels were significantly lower in them. The Let-7a expression level had a statistically significant relationship with breast cancer histological type and HER-2neu parameters, miR-17-5p, miR-125b, Let-7a, miR-34a, miR-21 and miR-99a levels with E-cadherin, miR-34a, miR-99a and miR-497 with CA15.3, miR-125b, miR-200a and miR-34a with the number of metastatic lymph nodes, miR-125a with the number of tumour foci and miR-200a with the status of having the neoadjuvant therapy. Serum miR-17-5p, miR-125a, miR-125b, miR-200a, Let-7a, miR-34a, miR-21, miR-99a and miR-497 expression levels were determined to have predictive and prognostic importance in breast cancer.

A cohort study investigating the role of Bisphenol A in the molecular pathogenesis of breast cancer

BACKGROUND

Breast cancer is an abnormal division of breast cells. Bisphenol A (BPA), an environmental toxicant, is identified as an emerging risk factor for breast cancer development. However, to the best of our knowledge, no previous study has investigated the BPA levels in breast cancer patients in Pakistan. The present study sought to explore the role of BPA in tumor growth among the Pakistani population.

METHODS

The levels of BPA were analyzed in the serum samples of breast cancer patients and controls by using HPLC. To elucidate the role of BPA to initiate tumorigenic events in breast tissue different biochemical assays along with expression analysis of tumor markers were performed.

RESULTS

The level of BPA in the serum samples of breast cancer patients was significantly higher than control. Histological analysis of breast cancer tissue samples revealed distinct subtypes of tumor, such as ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). There was a significant increase in ROS level while a significant decrease in the levels of superoxide dismutase (SOD) and catalase (CAT) enzymes in malignant breast tissue samples as compared to control tissue samples. We found upregulated expression of p53, ZEB1 and WNT1 genes at mRNA level in malignant breast tissue samples by 17 folds, 328 folds and 35 folds, respectively. p53 protein expression in malignant breast tissue samples was also enhanced at the translational level.

CONCLUSION

Current findings suggest a relationship between BPA and the progression of breast cancer among the Pakistani population.

Role of Truncated O-GalNAc Glycans in Cancer Progression and Metastasis in Endocrine Cancers

Glycans are an essential part of cells, playing a fundamental role in many pathophysiological processes such as cell differentiation, adhesion, motility, signal transduction, host-pathogen interactions, tumour cell invasion, and metastasis development. These glycans are also able to exert control over the changes in tumour immunogenicity, interfering with tumour-editing events and leading to immune-resistant cancer cells. The incomplete synthesis of O-glycans or the formation of truncated glycans such as the Tn-antigen (Thomsen nouveau; GalNAcα- Ser/Thr), its sialylated version the STn-antigen (sialyl-Tn; Neu5Acα2-6GalNAcα-Ser/Thr) and the elongated T-antigen (Thomsen-Friedenreich; Galβ1-3GalNAcα-Ser/Thr) has been shown to be associated with tumour progression and metastatic state in many human cancers. Prognosis in various human cancers is significantly poor when they dedifferentiate or metastasise. Recent studies in glycobiology have shown truncated O-glycans to be a hallmark of cancer cells, and when expressed, increase the oncogenicity by promoting dedifferentiation, risk of metastasis by impaired adhesion (mediated by selectins and integrins), and resistance to immunological killing by NK cells. Insight into these truncated glycans provides a complimentary and attractive route for cancer antigen discovery. The recent emergence of immunotherapies against cancers is predicted to harness the potential of using such agents against cancer-associated truncated glycans. In this review, we explore the role of truncated O-glycans in cancer progression and metastasis along with some recent studies on the role of O-glycans in endocrine cancers affecting the thyroid and adrenal gland.

Layered Double Hydroxide-Loaded miR-30a for the Treatment of Breast Cancer In Vitro and In Vivo

MicroRNAs (miRNAs) play an essential role in cancer therapy, but the disadvantages of its poor inherent stability, rapid clearance, and low delivery efficiency affect the therapeutic efficiency. Loading miRNAs by nanoformulations can improve their bioavailability and enhance therapeutic efficiency, which is an effective miRNA delivery strategy. In this study, we synthesized layered double hydroxides (LDH), which are widely used as carriers of drugs or genes due to the characteristics of good biocompatibility, high loading capacity, and pH sensitivity. We loaded the suppressor oncogene miR-30a on LDH nanomaterials (LDH@miR-30a) and determined the mass ratio of miRNA binding to LDH by agarose gel electrophoresis. LDH@miR-30a was able to escape the lysosomal pathway and was successfully phagocytosed by breast cancer SKBR3 cells and remained detectable in the cells after 24 h of co-incubation. In vitro experiments showed that LDH@miR-30a-treated SKBR3 cells showed decreased proliferation and cell cycle arrest in the G0/G1 phase and LDH@miR-30a was able to regulate the epithelial-mesenchymal transition (EMT) process and inhibit cell migration and invasion by targeting SNAI1. Meanwhile, in vivo experiments showed that nude mice treated with LDH@miR-30a showed a significant reduction in their solid tumors and no significant impairment of vital organs was observed. In conclusion, LDH@miR-30a is an effective drug delivery system for the treatment of breast cancer.

Study of anti-tumorigenic actions of essential fatty acids in a murine mammary gland adenocarcinoma by micro-XRF

In the present work, a statistical experiment based on the microscopy X-ray fluorescence technique was developed to evaluate the effect of diets rich in ω-3 and ω-6 polyunsaturated fatty acids on tumour tissues. Relative variations on the local content of P, S, Ca, Fe, Cu and Zn were analysed in the experiment. Neoplastic tissues were obtained from mammary gland adenocarcinomas inoculated in mice belonging to three different dietary groups: normal, rich in ω-3 and in ω-6 polyunsaturated fatty acids. Slices of 30 microns thick sections of these samples were scanned in the air atmosphere in areas of 5 mm × 5 mm with a spatial resolution of 50 microns using synchrotron radiation. Principal component analysis was employed to analyse the correlation between the X-ray fluorescence signals of P, S, Ca, Fe, Cu and Zn. The subsequent application of the K-means clustering was used for the automatic segmentation of the image scans. By comparison with conventional histological analysis, the clusters were positively identified as tumour parenchyma, transition and necrotic region. The calculation of the mean content of P, S, Ca, Fe, Cu, and Zn in these regions showed that dietary polyunsaturated fatty acids modify elemental content of tumour parenchyma, suggesting its involvement in the antitumour effects of chia oil and protumour effects of safflower oil.

Breast carcinogenesis induced by organophosphorous pesticides

Breast cancer is a major health threat to women worldwide and the leading cause of cancer-related death. The use of organophosphorous pesticides has increased in agricultural environments and urban settings, and there is evidence that estrogen may increase breast cancer risk in women. The mammary gland is an excellent model for examining its susceptibility to different carcinogenic agents due to its high cell proliferation capabilities associated with the topography of the mammary parenchyma and specific stages of gland development. Several experimental cellular models are presented here, in which the animals were exposed to chemical compounds such as pesticides, and endogenous substances such as estrogens that exert a significant effect on normal breast cell processes at different levels. Such models were developed by the effect of malathion, parathion, and eserine, influenced by estrogen demonstrating features of cancer initiation in vivo as tumor formation in rodents; and in vitro in the immortalized normal breast cell line MCF-10F, that when transformed showed signs of carcinogenesis such as increased cell proliferation, anchorage independence, invasive capabilities, modulation of receptors and genomic instability. The role of acetylcholine was also demonstrated in the MCF-10F, suggesting a role not only as a neurotransmitter but also with other functions, such as induction of cell proliferation, playing an important role in cancer. Of note, this is a unique experimental approach that identifies mechanistic signs that link organophosphorous pesticides with breast carcinogenesis.

MAGED4B is a Poor Prognostic Marker of Stomach Adenocarcinoma and a Potential Therapeutic Target for Stomach Adenocarcinoma Tumorigenesis

Background

Gastric cancer is the second most common cause of cancer death worldwide with poor overall prognosis. It is important to study the molecular mechanism of stomach adenocarcinoma (STAD). MAGED4B, a member of the melanoma antigen gene (MAGE) family, is highly expressed in many tumor cells and is associated with tumor progression. Its prognostic value in and the function of the encoded protein are still unclear.

Methods

The data of 415 STAD tissues was retrieved from TCGA database, and the expression level of MAGED4B mRNA was evaluated. The correlation between the expression of MAGED4B mRNA and the progression free survival (PFS) time of STAD patients was evaluated by Kaplan Meier analysis. The STAD cell lines with overexpressed and silent MAGED4B were constructed, and the effects of MAGED4B on the viability, migration and proliferation were evaluated by the CCK-8, scratch test and EDU test. The flow cytometry was used to detect apoptosis with overexpressed and silent MAGED4B under the cisplatin treatment, and WB was used to detect the expressions of related proteins, such as TNF-α.

Results

The expression level of MAGED4B mRNA in the STAD tissues was higher than that in the normal tissues, and its high expression was related to poor PFS. The overexpression of MAGED4B in the STAD cell lines can promote the vitality, motility and proliferation of the STAD cells, while the silencing of MAGED4B can inhibit the above three cell functions of the STAD cells. The overexpression of MAGED4B can reduce the cisplatin induced apoptosis and increase the cisplatin IC₅₀; the silencing of MAGED4B can promote the cisplatin induced apoptosis and reduce the cisplatin IC₅₀. The overexpression of MAGED4B reduced the protein levels of TRIM27 and TNF- α.

Conclusion

MAGED4B could be a valuable prognostic biomarker and a therapeutic target for gastric adenocarcinoma of great interest.

Extracellular vesicles from MDA-MB-231 breast cancer cells stimulated with insulin-like growth factor 1 mediate an epithelial-mesenchymal transition process in MCF10A mammary epithelial cells

Insulin-like growth factor-1 (IGF-1) plays an important role in function and development of the mammary gland. However, high levels of IGF-1 has been associated with an increased risk of breast cancer development. Epithelial-mesenchymal transition (EMT) is a process where epithelial cells lose their epithelial characteristics and acquire a mesenchymal phenotype, which is considered one of the most important mechanisms in cancer initiation and promotion of metastasis. Extracellular vesicles (EVs) are released into the extracellular space by different cell types, which mediate intercellular communication and play an important role in different physiological and pathological processes, such as cancer. In this study, we demonstrate that EVs from MDA-MB-231 breast cancer cells stimulated with IGF-1 (IGF-1 EVs) decrease the levels of E-cadherin, increase the expression of vimentin and N-cadherin and stimulate the secretion of metalloproteinase-9 in mammary non-tumorigenic epithelial cells MCF10A. IGF-1 EVs also induce the expression of Snail1, Twist1 and Sip1, which are transcription factors involved in EMT. Moreover, IGF-1 EVs induce activation of ERK1/2, Akt1 and Akt2, migration and invasion. In summary, we demonstrate, for the first time, that IGF-1 EVs induce an EMT process in mammary non-tumorigenic epithelial cells MCF10A.

Celastrol inhibits the migration and invasion and enhances the anti-cancer effects of docetaxel in human triple-negative breast cancer cells

The molecular mechanism of anti-metastatic effect of celastrol is not fully understood in breast cancer cells. Herein, we investigated the activity and molecular mechanism of celastrol in triple-negative breast cancer (TNBC) cells, which is a more aggressive subtype of breast cancer. The results of wound healing assay and trans-well assay revealed that celastrol inhibited cell migration and invasion under sub-cytotoxic concentrations in MDA-MB-231 and MDA-MB-468 TNBC cells. Molecular data showed that the effect of celastrol on TNBC cells might be mediated via up-regulation of E-cadherin, a key protein involved in epithelial-mesenchymal transition (EMT). In addition, Hakai, an E3 ligase responsible for E-cadherin complex ubiquitination and degradation, was down-regulated under celastrol treatment. Hakai partially contributed to celastrol-induced anti-invasive effect. In addition, celastrol and docetaxel could synergistically inhibit growth and metastasis of MDA-MB-231 cells. Our results showing anti-migratory/anti-invasive effects of celastrol and associated mechanisms provide new evidence for the development of celastrol as a potential anti-metastatic compound against highly aggressive breast cancer, and celastrol in combination with docetaxel might potentially be used as a novel regimen for the treatment of TNBC.

The Pleiotropy of PAX5 Gene Products and Function

PAX5, a member of the Paired Box (PAX) transcription factor family, is an essential factor for B-lineage identity during lymphoid differentiation. Mechanistically, PAX5 controls gene expression profiles, which are pivotal to cellular processes such as viability, proliferation, and differentiation. Given its crucial function in B-cell development, PAX5 aberrant expression also correlates with hallmark cancer processes leading to hematological and other types of cancer lesions. Despite the well-established association of PAX5 in the development, maintenance, and progression of cancer disease, the use of PAX5 as a cancer biomarker or therapeutic target has yet to be implemented. This may be partly due to the assortment of PAX5 expressed products, which layers the complexity of their function and role in various regulatory networks and biological processes. In this review, we provide an overview of the reported data describing PAX5 products, their regulation, and function in cellular processes, cellular biology, and neoplasm.

DNMT3B-mediated FAM111B methylation promotes papillary thyroid tumor glycolysis, growth and metastasis

Over the past decades, the incidence of thyroid cancer (TC) rapidly increased all over the world, with the papillary thyroid cancer (PTC) accounting for the vast majority of TC cases. It is crucial to investigate novel diagnostic and therapeutic targets for PTC and explore more detailed molecular mechanisms in the carcinogenesis and progression of PTC. Based on the TCGA and GEO databases, FAM111B is downregulated in PTC tissues and predicts better prognosis in PTC patients. FAM111B suppresses the growth, migration, invasion and glycolysis of PTC both in vitro and in vivo. Furthermore, estrogen inhibits FAM111B expression by DNMT3B methylation via enhancing the recruitment of DNMT3B to FAM111B promoter. DNMT3B-mediated FAM111B methylation accelerates the growth, migration, invasion and glycolysis of PTC cells. In clinical TC patient specimens, the expression of FAM111B is inversely correlated with the expressions of DNMT3B and the glycolytic gene PGK1. Besides, the expression of FAM111B is inversely correlated while DNMT3B is positively correlated with glucose uptake in PTC patients. Our work established E2/DNMT3B/FAM111B as a crucial axis in regulating the growth and progression of PTC. Suppression of DNMT3B or promotion of FAM111B will be potential promising strategies in the estrogen induced PTC.

ST8SIA6-AS1 Promotes the Epithelial-to-Mesenchymal Transition and Angiogenesis of Pituitary Adenoma

To investigate the effect of long noncoding RNA ST8SIA6-AS1 on the epithelial-to-mesenchymal transition (EMT) and angiogenesis of pituitary adenoma and its possible mechanism. The expression levels of ST8SIA6-AS1 and HOXA9 in noninvasive pituitary adenoma and invasive pituitary adenoma were detected using qRT-PCR. sh-ST8SIA6-AS1 transfection silenced the expression of ST8SIA6-AS1 in GH3 and GTI-1 cells. The effects of ST8SIA6-AS1 on the proliferation, invasion, angiogenesis, and EMT of GH3 and GTI-1 pituitary adenoma cells were detected. The migration ability of cells was detected through scratch assay. Dual luciferase analysis verified the targeting relationship between ST8SIA6-AS1 and miR-5195-3p. ST8SIA6-AS1 and HOXA9 were highly expressed in invasive pituitary adenoma. In pituitary adenomas, miR-5195-3p directly targeted HOXA9. miR-5195-3p is the target gene of ST8SIA6-AS1. ST8SIA6-AS1 knockdown inhibited the proliferation, invasion, angiogenesis, and EMT of pituitary adenoma. HOXA9 expression mediates the biological effect of ST8SIA6-AS1. ST8SIA6-AS1 targets miR-5195-3p to regulate the expression of HOXA9 and promote the EMT of pituitary adenomas.

Role of let7-g and miR-221 level as potential predictors for overall survival of hepatocellular carcinoma patients

BACKGROUND AND STUDY AIMS

Hepatocellular carcinoma (HCC) is one of the most common cancer types worldwide. A hallmark of epithelial-mesenchymal transition is the loss of epithelial E-cadherin, which is considered an epithelial differentiation marker. MicroRNAs serve vital roles in various biological processes in the cell via post-transcriptional gene regulation. Therefore, the present study aimed to investigate the involvement of certain miRNAs in the progression of HCC.

PATIENTS AND METHODS

A reverse transcription-quantitative PCR assay was conducted to detect the expression levels of 20 EMT-related miRNAs in 36 fresh tissue biopsies from patients with primary HCC compared with healthy controls. Gene expression levels, as well as immunohistochemistry assays, were performed for E-cadherin, ZEB1 and ZEB2 proteins. The correlation between their expression levels and different clinicopathological factors was also assessed.

RESULTS

A significant decrease of E-Cadherin and an increase in ZEB1 expression levels were identified in HCC groups compared with controls, while no significant changes for ZEB2 were found. The absence of E-cadherin membranous protein was observed in ∼48% of the cases examined. Moreover, ZEB1 protein was absent in 46% of E-cadherin positive cases. Upregulation of miR-182, miR-221 and miR-222 expression levels, and downregulation of let-7g, miR-9, miR-16, miR29c, miR122, miR-145, miR-148a, miR-193b, miR-194 and miR-215 expression levels were identified. A positive correlation between let7-g with E-Cadherin expression was reported. No significant association was identified between each of E-cadherin, ZEB1, ZEB2 or miRNAs examined with different clinicopathological features of the patients. Furthermore, the low expression of let7-g and high expression of miR-221 were associated with poorer survival.

CONCLUSION

Collectively, the present data suggested that let7-g functions as a tumor suppressor in the development of HCC via regulating E-Cadherin. Furthermore, both let7-g and miR-221 may be potential biomarkers for the outcomes of HCC patients.

EGFR inhibition reverses epithelial‑mesenchymal transition, and decreases tamoxifen resistance via Snail and Twist downregulation in breast cancer cells

Tamoxifen resistance remains a major obstacle in the treatment of estrogen receptor (ER)‑positive breast cancer. In recent years, the crucial role of the epithelial‑mesenchymal transition (EMT) process in the development of drug resistance in breast cancer has been underlined. However, the central molecules inducing the EMT process during the development of tamoxifen resistance remain to be elucidated. In the present study, it was demonstrated that tamoxifen‑resistant breast cancer cells underwent EMT and exhibited an enhanced cell motility and invasive behavior. The inhibition of snail family transcriptional repressor 1 (Snail) and twist family BHLH transcription factor 1 (Twist) reversed the EMT phenotype and decreased the tamoxifen resistance, migration and invasion of tamoxifen‑resistant breast cancer cells. In addition, it was observed that the inhibition of epidermal growth factor receptor (EGFR) reversed the EMT phenotype in tamoxifen‑resistant MCF7 (MCF‑7/TR) cells via the downregulation of Snail and Twist. Notably, the EGFR inhibitor, gefitinib, decreased tamoxifen resistance, migration and invasion through the inhibition of Snail and Twist. On the whole, the results of the present study suggest that EGFR may be a promising therapeutic target for tamoxifen‑resistant breast cancer. Moreover, it was suggested that gefitinib may serve as a potent novel therapeutic strategy for breast cancer patients, who have developed tamoxifen resistance.

Non-homogeneous dispersion of graphene in polyacrylonitrile substrates induces a migrastatic response and epithelial-like differentiation in MCF7 breast cancer cells

Background

Recent advances from studies of graphene and graphene-based derivatives have highlighted the great potential of these nanomaterials as migrastatic agents with the ability to modulate tumor microenvironments. Nevertheless, the administration of graphene nanomaterials in suspensions in vivo is controversial. As an alternative approach, herein, we report the immobilization of high concentrations of graphene nanoplatelets in polyacrylonitrile film substrates (named PAN/G10) and evaluate their potential use as migrastatic agents on cancer cells.

Results

Breast cancer MCF7 cells cultured on PAN/G10 substrates presented features resembling mesenchymal-to-epithelial transition, e.g., (i) inhibition of migratory activity; (ii) activation of the expression of E-cadherin, cytokeratin 18, ZO-1 and EpCAM, four key molecular markers of epithelial differentiation; (iii) formation of adherens junctions with clustering and adhesion of cancer cells in aggregates or islets, and (iv) reorganization of the actin cytoskeleton resulting in a polygonal cell shape. Remarkably, assessment with Raman spectroscopy revealed that the above-mentioned events were produced when MCF7 cells were preferentially located on top of graphene-rich regions of the PAN/G10 substrates.

Conclusions

The present data demonstrate the capacity of these composite substrates to induce an epithelial-like differentiation in MCF7 breast cancer cells, resulting in a migrastatic effect without any chemical agent-mediated signaling. Future works will aim to thoroughly evaluate the mechanisms of how PAN/G10 substrates trigger these responses in cancer cells and their potential use as antimetastatics for the treatment of solid cancers.

Graphical Abstract

Cadherin Signaling in Cancer and Autoimmune Diseases

Cadherins mediate cell–cell adhesion through a dynamic process that is strongly dependent on the cellular context and signaling. Cadherin regulation reflects the interplay between fundamental cellular processes, including morphogenesis, proliferation, programmed cell death, surface organization of receptors, cytoskeletal organization, and cell trafficking. The variety of molecular mechanisms and cellular functions regulated by cadherins suggests that we have only scratched the surface in terms of clarifying the functions mediated by these versatile proteins. Altered cadherins expression is closely connected with tumorigenesis, epithelial–mesenchymal transition (EMT)-dependent fibrosis, and autoimmunity. We review the current understanding of how cadherins contribute to human health and disease, considering the mechanisms of cadherin involvement in diseases progression, as well as the clinical significance of cadherins as therapeutic targets.

Radiation-induced H3K9 methylation on E-cadherin promoter mediated by ROS/Snail axis : Role of G9a signaling during lung epithelial-mesenchymal transition

Lung cancer patients who have undergone radiotherapy developed severe complications such as pneumonitis and fibrosis. Upon irradiation, epithelial cells acquire mesenchymal phenotype via a process called epithelial to mesenchymal transition (EMT), which plays a vital role in organ fibrosis. Several mechanisms have been studied on EMT, however, the correlation between radiation-induced EMT and epigenetic changes are not well known. In the present study, we investigated the role of histone methyltransferase G9a on radiation-induced EMT signaling. There was an increase in total global histone methylation level in irradiated epithelial cells. Western blot analysis on irradiated cells showed an increased expression of H3K9me2/3. The pre-treatment of G9a inhibitor enhanced E-cadherin expression and decreased the mesenchymal markers like N-cadherin, vimentin in the radiated group. Surprisingly, radiation-induced ROS generation and pERK1/2 levels were also inhibited by G9a inhibitor BIX01294, which is showing its antioxidant potential. The ChIP-qPCR analysis on the E-cadherin promoter suggested that G9a and Snail might have formed complex to enrich suppressive marker H3K9me2/3. On the whole, our present study suggested that 1] ROS could modify H3K9 methylation via G9a and promote radiation-induced lung EMT in Beas2B and A549 cells 2] E-cadherin promoter enrichment with heterochromatin mark H3K9me2 expression upon irradiation could be modified by regulating G9a methyltransferase.

High Adenosine Extracellular Levels Induce Glioblastoma Aggressive Traits Modulating the Mesenchymal Stromal Cell Secretome

Glioblastoma is an aggressive, fast-growing brain tumor influenced by the composition of the tumor microenvironment (TME) in which mesenchymal stromal cell (MSCs) play a pivotal role. Adenosine (ADO), a purinergic signal molecule, can reach up to high micromolar concentrations in TME. The activity of specific adenosine receptor subtypes on glioma cells has been widely explored, as have the effects of MSCs on tumor progression. However, the effects of high levels of ADO on glioma aggressive traits are still unclear as is its role in cancer cells-MSC cross-talk. Herein, we first studied the role of extracellular Adenosine (ADO) on isolated human U343MG cells as a glioblastoma cellular model, finding that at high concentrations it was able to prompt the gene expression of Snail and ZEB1, which regulate the epithelial–mesenchymal transition (EMT) process, even if a complete transition was not reached. These effects were mediated by the induction of ERK1/2 phosphorylation. Additionally, ADO affected isolated bone marrow derived MSCs (BM-MSCs) by modifying the pattern of secreted inflammatory cytokines. Then, the conditioned medium (CM) of BM-MSCs stimulated with ADO and a co-culture system were used to investigate the role of extracellular ADO in GBM–MSC cross-talk. The CM promoted the increase of glioma motility and induced a partial phenotypic change of glioblastoma cells. These effects were maintained when U343MG cells and BM-MSCs were co-cultured. In conclusion, ADO may affect glioma biology directly and through the modulation of the paracrine factors released by MSCs overall promoting a more aggressive phenotype. These results point out the importance to deeply investigate the role of extracellular soluble factors in the glioma cross-talk with other cell types of the TME to better understand its pathological mechanisms.

Role of Cadherins in Cancer-A Review

Cadherins play an important role in tissue homeostasis, as they are responsible for cell-cell adhesion during embryogenesis, tissue morphogenesis, differentiation and carcinogenesis. Cadherins are inseparably connected with catenins, forming cadherin-catenin complexes, which are crucial for cell-to-cell adherence. Any dysfunction or destabilization of cadherin-catenin complex may result in tumor progression. Epithelial mesenchymal transition (EMT) is a mechanism in which epithelial cadherin (E-cadherin) expression is lost during tumor progression. However, during tumorigenesis, many processes take place, and downregulation of E-cadherin, nuclear β-catenin and p120 catenin (p120) signaling are among the most critical. Additional signaling pathways, such as Receptor tyrosine kinase (RTK), Rho GTPases, phosphoinositide 3-kinase (PI3K) and Hippo affect cadherin cell-cell adhesion and also contribute to tumor progression and metastasis. Many signaling pathways may be activated during tumorigenesis; thus, cadherin-targeting drugs seem to limit the progression of malignant tumor. This review discusses the role of cadherins in selected signaling mechanisms involved in tumor growth. The clinical importance of cadherin will be discussed in cases of human and animal cancers.

Radiation-induced H3K9 tri-methylation in E-cadherin promoter during lung EMT: in vitro and in vivo approaches using vanillin

Radiotherapy is an important treatment regime for lung cancer, worldwide. However, radiation-induced pneumonitis and fibrosis are the treatment-limiting toxicities among patients who have undergone radiotherapy. The epithelial cells via epithelial to mesenchymal transition [EMT] acquires mesenchymal phenotype, which ultimately leads to fibrosis. Many investigations are focussed on understanding the signalling pathways mediating in EMT, however, the role of histone methylation is less understood in radiation-induced lung EMT. In the present study, we analysed the effect of vanillin, an antioxidant, on histone methylation during radiation-induced EMT. The thoracic region of Wistar rats was irradiated with a fractionated dose of X-ray (3 Gy/day) for two weeks (total of 30 Gy). The irradiated animals were sacrificed at the 8th and 16th weeks and tissues were used for analyses. Our data showed that radiation decreased the level of antioxidant enzymes such as SOD, catalase and reduced glutathione that would ultimately enhance oxidative stress in the tissues. Histopathological analysis revealed that radiation increased the infiltration of inflammatory cells to the tissue injury site. Total global histone methylation was increased upon irradiation, which was effectively prevented by vanillin administration. Vanillin enhanced E-cadherin expression and decreased the mesenchymal markers N-cadherin and vimentin in the irradiated lung tissue. The ChIP-qPCR analysis suggested that snail expression in the nucleus might involve in the enrichment of suppressive marker H3K9me3 on the E-cadherin promoter. Finally, we suggested that vanillin administration decreased radiation-induced oxidative stress and EMT expression. Additionally, irradiation increased the H3K9 methylation status with nuclear translocation of snail during lung EMT.

Adipose Tissue from Lean and Obese Mice Induces a Mesenchymal to Epithelial Transition-Like Effect in Triple Negative Breast Cancers Cells Grown in 3-Dimensional Culture

Breast cancer is the second leading cause of cancer-related mortality among women globally with obesity being one risk factor. Obese breast cancer patients have at least a 30% increased risk of death from breast cancer compared to non-obese breast cancer patients because they present with larger tumors and generally have increased rates of metastasis. Moreover, obese breast cancer patients respond more poorly to treatment compared to non-obese patients, particularly pre-menopausal women diagnosed with triple negative breast cancer (TNBC). To help understand the molecular mechanisms underlying the increased metastasis associated with obesity, we previously established a three-dimensional culture system that permits the co-culture of adipocytes and TNBC cells in a manner that mimics an in vivo milieu. Using this system, we demonstrate that white adipose tissue from both lean and obese mice can induce a partial mesenchymal-to-epithelial transition (MET). Triple negative breast cancer cells adopt an epithelial morphology and have an increased expression of some epithelial markers, but they maintain the expression of mesenchymal markers, furnishing the breast cancer cells with hybrid properties that are associated with more aggressive tumors. Thus, these data suggest that adipose tissue has the potential to promote secondary tumor formation in lean and obese women. Further work is needed to determine if targeting the partial MET induced by adipose tissue could reduce metastasis.

Family's History Based on the CDH1 Germline Variant (c.360delG) and a Suspected Hereditary Gastric Cancer Form

Hereditary diffuse gastric cancer (HDGC) is a cancer susceptibility syndrome caused by germline pathogenic variant in CDH1, the gene encoding E-cadherin. The germline loss-of-function variants are the only proven cause of the cancer syndrome HDGC, occurring in approximately 10-18% of cases and representing a helpful tool in genetic counseling. The current case reports the family history based on a CDH1 gene variant, c.360delG, p.His121Thr in a suspected family for hereditary gastric cancer form. This frameshift deletion generates a premature stop codon at the amino acid 214, which leads to a truncated E-cadherin protein detecting it as a deleterious variant. The present study expands the mutational spectra of the family with the CDH1 variant. Our results highlight the clinical impact of the reported CDH1 variant running in gastric cancer families.

Expression of epithelial-Mesenchymal transition related markers in Plasmacytoid Urothelial carcinoma of the urinary bladder

Background

Plasmacytoid urothelial carcinoma (PUC) of the urinary bladder is a variant of urothelial carcinoma that carries a poor prognosis. The epithelial-mesenchymal transition (EMT) has been demonstrated to contribute to tumor progression. As the cause of the increased aggressiveness of PUC is unknown, we investigated PUC and EMT-related marker expression.

Methods

A total of 633 bladder carcinoma cases diagnosed from 2006 to 2015 at the Nippon Medical School Hospital were analyzed. Twelve patients were found to have plasmacytoid histology and diagnosed with PUC. Slides were evaluated for percentage of plasmacytoid variant, and stained for E-cadherin, N-cadherin, Vimentin, Fibronectin and Snail expression.

Results

The incidence of PUC was 1.9% (12/633). The median patient age at diagnosis was 71 years (range, 60–80 years) and the male-female ratio was 11:1. All but three patients had stage T2b or higher. The median overall survival was 10 months. In 10/12 cases, Snail and N-cadherin were positive. Vimentin was positive in 9/12 cases. Fibronectin was positive in 8/12 cases. While E-cadherin was negative in 10/12 cases. Nine cases showed > 10% plasmacytoid component. Eight of the nine patients (88.9%) with > 10% plasmacytoid component died.

Conclusions

The results indicate that PUC may induce EMT and may be associated with high invasion.

Selective EP2 and Cox-2 inhibition suppresses cell migration by reversing epithelial-to-mesenchymal transition and Cox-2 overexpression and E-cadherin downregulation are implicated in neck metastasis of hypopharyngeal cancer

Cyclooxygenase-2 (Cox-2) has been shown to promote cancer initiation and progression through pleiotropic functions including induction of epithelial-to-mesenchymal transition (EMT) via its predominant product prostaglandin E₂ that binds to the cognate receptor EP2. Hence, pharmacological inhibition at the level of EP2 is assumed to be a more selective alternative with less risk to Cox-2 inhibition. However, little is known regarding the anti-cancer effect of an EP2 antagonist on the malignant properties of cancers including hypopharyngeal squamous cell carcinoma (HPSCC). The present study found that both the Cox-2 inhibitor celecoxib and the EP2 antagonist PF-04418948 upregulated CDH-1 expression, restored membranous localization of E-cadherin, and reduced vimentin expression, by downregulating the transcriptional repressors of E-cadherin in BICR6 and FaDu cells. Such Cox-2 or EP2 inhibition-induced EMT reversal led to repressed migration ability in both cells. Immunohistochemical analysis of surgical HPSCC specimens demonstrated an inverse relationship in expression between Cox-2 and E-cadherin both in the context of statistics (P = 0.028) and of reciprocal immunolocalization in situ. Multivariate logistic regression revealed that overexpression of Cox-2 (P < 0.001) and downregulation of E-cadherin (P = 0.016) were both independently predictive of neck metastasis. These results suggest that suppression of cell migration ability via reversing EMT by inhibiting the Cox-2/EP2 signaling may contribute to preventing the development and progression of lymphatic metastasis. Collectively, targeting Cox-2/EP2, especially using EP2 antagonist, can be a promising therapeutic strategy by exerting an anti-metastatic effect via EMT reversal for improving the treatment outcomes of patients with various cancers including HPSCC.

LRIG3 represses cell motility by inhibiting slug via inactivating ERK signaling in human colorectal cancer

Metastasis is responsible for 90% of colorectal cancer (CRC)-related deaths. In the present study, we identified a novel key regulator of CRC metastasis, leucine-rich repeats and immunoglobulin-like domains protein 3 (LRIG3), which was significantly decreased in CRC tissues and cell lines. Downregulation of LRIG3 was attributed to copy number loss and promoter hypermethylation. Low LRIG3 expression was positively correlated with metastatic clinical features and shorter survival time. Functional experiments showed that knockout of LRIG3 markedly enhanced CRC cell migration and invasion ability, whereas reintroduction of LRIG3 exerted the opposite effects. Regarding the mechanism, LRIG3 could facilitate the binding of DUSP6 to ERK1/2, resulting in the dephosphorylation of ERK1/2 and subsequently downregulation of slug, an epithelial-to-mesenchymal transition trigger, thereby constraining CRC cell motility. Importantly, LRIG3 expression was strongly negatively correlated with slug or p-ERK1/2 expression in CRC tissues. Collectively, our data suggest that LRIG3 is a novel suppressor of CRC metastasis, reactivation of LRIG3 may be a promising therapeutic approach for metastatic CRC patients.

A proteomics outlook towards the elucidation of epithelial-mesenchymal transition molecular events

The main cause of death in cancer is the spread, or metastasis, of cancer cells to distant organs with consequent tumor formation. Additionally, metastasis is a process that demands special attention, as the cellular transformations make cancer at this stage very difficult or occasionally even impossible to be cured. The main process that converts epithelial tumor cells to mesenchymal-like metastatic cells is the Epithelial to Mesenchymal Transition (EMT). This process allows stationary and polarized epithelial cells, which are connected laterally to several types of junctions as well as the basement membrane, to undergo multiple biochemical changes that enable disruption of cell-cell adherence and apical-basal polarity. Moreover, the cells undergo important reprogramming to remodel the cytoskeleton and acquire mesenchymal characteristics such as enhanced migratory capacity, invasiveness, elevated resistance to apoptosis and a large increase in the production of ECM components. As expected, the alterations of the protein complement are extensive and complex, and thus exploring this by proteomic approaches is of particular interest. Here we review the overall findings of proteome modifications during EMT, mainly focusing on molecular signatures observed in multiple proteomic studies as well as coordinated pathways, cellular processes and their clinical relevance for altered proteins. As a result, an interesting set of proteins is highlighted as potential targets to be further investigated in the context of EMT, metastasis and cancer progression.

Spinal versus intracranial meningioma: Expression of E-cadherin and Fascin with relation to clinicopathological features

BACKGROUND

E-cadherin and Fascin are adhesive proteins that are expressed in many tumors. It was supposed that loss of expression of these proteins is associated with increased aggressiveness of the tumor. Whether spinal and intracranial meningiomas express adhesion proteins in different rates is not yet known.

OBJECTIVE

We aimed to investigate the expression of E-cadherin and Fascin in a large number of meningioma specimens and determine if clinical and prognostic significance existsMETHODS: One hundred and thirty-four spinal and intracranial meningioma samples were collected. Manual TMA blocks were constructed and immunohistochemistry for E-cadherin and Fascin was done. Focal or diffuse staining was considered positive.

RESULTS

Intracranial meningioma occurred in significantly younger age than spinal ones. Most of spinal meningiomas were of transitional histology. E-cadherin was expressed in 38.8% of cases. Spinal meningiomas showed statistically significant negative expression of E-cadherin than intracranial tumors. All atypical meningiomas showed negative E-cadherin expression. Fascin was expressed in 9% of cases with significant expression in atypical cases.

CONCLUSIONS

Aggressive behavior of meningioma could be explained in part by loss of E-cadherin and overexpression of Fascin especially in spinal meningiomas. Further studies are suggested to explore the biological aspects of spinal and intracranial meningiomas for constructing tailored targeted therapies.

CD47-SIRPα Signaling Induces Epithelial-Mesenchymal Transition and Cancer Stemness and Links to a Poor Prognosis in Patients with Oral Squamous Cell Carcinoma

Background: Oral squamous cell carcinoma (OSCC), with high mortality rates, is one of the most diagnosed head and neck cancers. Epithelial-to-mesenchymal transition (EMT) and the generation of cancer stem cells (CSCs) are two keys for therapy-resistance, relapse, and distant metastasis. Accumulating evidence indicates that aberrantly expressed cluster of differentiation (CD)47 is associated with cell-death evasion and metastasis; however, the role of CD47 in the generation of CSCs in OSCC is not clear. Methods: We investigated the functional roles of CD47 in OSCC cell lines SAS, TW2.6, HSC-3, and FaDu using the bioinformatics approach, immunoblotting, immunofluorescence staining, and assays for cellular migration, invasion, colony, and orosphere formation, as well as radiosensitivity. Results: We demonstrated increased expression of CD47 in OSCC patients was associated with an estimated poorly survival disadvantage (p = 0.0391) and positively correlated with the expression of pluripotency factors. Silencing CD47 significantly suppressed cell viability and orosphere formation, accompanied by a downregulated expression of CD133, SRY-Box transcription factor 2 (SOX2), octamer-binding transcription factor 4 (OCT4), and c-Myc. In addition, CD47-silenced OSCC cells showed reduced EMT, migration, and clonogenicity reflected by increased E-cadherin and decreased vimentin, Slug, Snail, and N-cadherin expression. Conclusion: Of therapeutic relevance, CD47 knockdown enhanced the anti-OSCC effect of radiotherapy. Collectively, we showed an increased CD47 expression promoted the generation of CSCs and malignant OSCC phenotypes. Silencing CD47, in combination with radiation, could provide an alternative and improved therapeutic efficacy for OSCC patients.

Prognostic phenotypic classification for canine mammary tumors

Mammary neoplasms are a heterogeneous form of disease, and in order to determine its course and biological features with more accuracy, investigations based on tumor phenotypes are required. The aim of the present study was to propose and validate a phenotypic classification for canine mammary tumors and to assess any association between clinicopathological characteristics, survival and prognosis. For the immunohistochemistry analysis, the primary antibodies against estrogen receptor-α, progesterone receptor, human epidermal growth factor receptor 2 (HER-2)/neu and E-cadherin were used. A total of 110 canine mammary tumors were investigated; 42 tumors were classified as luminal A, 41 as luminal B, 17 as triple-negative and 10 as HER-2-positive. The luminal A and B phenotypes were associated with improved prognosis, whereas HER-2positive and triple-negative tumors were more aggressive, and exhibited a significant association with the occurrence of metastasis, a worse Tumor-Node-Metastasis classification and shorter survival time (P<0.05). In addition, there were different levels of E-cadherin expression intensity observed among the four tumor profiles investigated. Luminal A and B phenotypes presented an upregulation of E-cadherin compared with the HER-2 positive and triple-negative phenotypes (P<0.05). From the results of the present study, the proposed immunohistochemical panel and phenotypic classification techniques could be useful diagnostic tools with a good technical applicability in veterinary oncology. The analysis of E-cadherin expression in the panel of tumor markers allowed a more accurate classification for determining the biological features of the mammary tumor.

Two Novel Tri-Aryl Derivatives Attenuate the Invasion-Promoting Effects of Stromal Mesenchymal Stem Cells on Breast Cancer

Background:

The concept of Epithelial-Mesenchymal Transition (EMT) to promote carcinoma progression has been recognized as a venue for research on novel anticancer drugs. Triaryl template-based structures are one of the pivotal structural features found in a number of compounds with a wide variety of biological properties including anti-breast cancer. Among the various factors triggering EMT program, cyclooxygenase-2 (COX-2), NF-κB as well as the transforming growth factor-beta (TGF-β) have been widely investigated.

Objective:

Here, we aim to investigate the effect of two novel compounds A and B possessing triaryl structures, which interact with both COX-2 and TGF-β active sites and suppress NF-κB activation, on EMT in a co-culture system with breast cancer and stromal cells.

Methods:

MDA-MB-231 and bone-marrow mesenchymal stem (BM-MS) cells were co-cultured in a trans-well plate. Migration, matrigel-based invasion and colony formation in soft agar assays along with Real- time PCR and Western blot analysis were performed to examine the effect of compounds A and B on the invasive properties of MDA-MB-231 cells after 72 hours of co-culturing with BM-MSCs. In addition, TGF-beta interaction was investigated by Localized Surface Plasmon Resonance (LSPR).

Results:

BM-MSCs enhanced migration, invasion and anchorage-independent growth of the co-cultured MDAMB- 231 cells. A reduction in E-cadherin level concomitant with an increase in vimentin and N-cadherin levels following the co-culture implied EMT as the underlying process. Compounds A and B inhibited invasion and anchorage-independent growth of breast cancer cells co-cultured with BM-MSCs at 10µM. The observed inhibitory effects along with an increase in E-cadherin and a reduction in vimentin and ZEB2 levels suggest that the anti-invasive properties of compounds A and B might proceed through the blockade of stromal cell-induced EMT, mediated by their interaction with TGF-beta.

Conclusion:

These findings introduce compounds A and B as novel promising agents, which prevent EMT in invasive breast cancer cells.

Epithelial-mesenchymal plasticity-engaging stemness in an interplay of phenotypes

Cancer is a genetic disease which results in a functional imbalance between tumour-repressive and oncogenic signals. The WHO highlights the burden of this indomitable disease, listing it as the second leading cause of death globally. The major cause of cancer-related death is rarely the effect of the primary tumour itself, but rather, the devastating spread of cancer cells in metastases. Epithelial-mesenchymal plasticity (EMP)-termed as the ability of cells to maintain its plasticity and transit between epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) states-plays a fundamental role in cancer metastasis. These cell transitions allow them migrate from the primary tumour and invade the secondary site. EMP is associated with migration, invasion, colonisation, self-renewal and drug resistance. This review briefly elucidates the mechanism of EMP and the association between cancer stem cells (CSCs) and circulating tumour cells (CTCs), biomarkers and signalling pathways involved in EMP as well as drug resistance and therapeutic targeting.

The molecular mechanisms underlying reduced E-cadherin expression in invasive ductal carcinoma of the breast: high throughput analysis of large cohorts

E-cadherin is a tumor suppressor gene in invasive lobular breast cancer. However, a proportion of high-grade ductal carcinoma shows reduced/loss of E-cadherin. In this study, we assessed the underlying mechanisms and molecular implications of E-cadherin loss in invasive ductal carcinoma. This study used large, well-characterized cohorts of early-stage breast cancer-evaluated E-cadherin expression via various platforms including immunohistochemistry, microarray analysis using Illumina HT-12 v3, copy number analysis using Affymetrix SNP 6.0 arrays, and next-generation sequencing for differential gene expression. Our results showed 27% of high-grade invasive ductal carcinoma showed reduced/loss of E-cadherin membranous expression. CDH1 copy number loss was in 21% of invasive ductal carcinoma, which also showed low CDH1 mRNA expression (p = 0.003). CDH1 copy number was associated with copy number loss of TP53, ATM, BRCA1, and BRCA2 (p < 0.001). Seventy-nine percent of invasive ductal carcinoma with reduced CDH1 mRNA expression showed elevated expression of E-cadherin transcription suppressors TWIST2, ZEB2, NFKB1, LLGL2, CTNNB1 (p < 0.01). Reduced/loss E-cadherin expression was associated with differential expression of 2143 genes including those regulating Wnt (FZD2, GNG5, HLTF, WNT2, and CER1) and PIK3-AKT (FGFR2, GNF5, GNGT1, IFNA17, and IGF1) signaling pathways. Interestingly, key genes differentially expressed between invasive lobular carcinoma and invasive ductal tumors did not show association with E-cadherin loss in invasive ductal carcinoma. We conclude that E-cadherin loss in invasive ductal carcinoma is likely a consequence of genomic instability occurring during carcinogenesis. Potential novel regulators controlling E-cadherin expression in invasive ductal carcinoma warrant further investigation.

Deletion of sorting nexin 27 suppresses proliferation in highly aggressive breast cancer MDA-MB-231 cells in vitro and in vivo

BACKGROUND

Sorting Nexin 27 (SNX27) belongs to a family of sortin nexins and possesses a unique binding domain at the C-terminus which mediates protein-protein interaction in intracellular trafficking, membrane remodeling, organelle motility, and tight junctions. However, its role in cancer development, especially in vivo, remains largely unknown.

METHODS

We have generated a stable SNX27 knockdown clone in a highly aggressive breast cancer cell line MDA-MB-231 using an inducible lentiviral shRNA system. Cell migration and proliferation of SNX27 knockdown (KD) cells were compared with wild-type (WT) cells by MTT and wound healing assay, respectively. The differences in colony formation between SNX27-KD and WT cells were detected by soft agar culture and matrigel 3D culture. Furthermore, tumor growth was examined in a xenograft nude mouse model using SNX27-KD and WT MDA-MB-231 cells. The critical EMT (epithelial-mesenchymal transition) regulators were examined in vitro and in vivo.

RESULTS

The wound healing assay showed that SNX27 knockdown significantly decreased cell motility and proliferation. Colony formation in soft agar showed that the SNX27 knockdown cells formed significantly fewer and smaller colonies than the parental MDA-MB-231 cells. Western blots and immunostaining showed that knockdown of SNX27 led to increased expression of E-cadherin and β-catenin proteins, which facilitate adhesion formation and reverse EMT. EMT is a cellular program that allows polarized, immotile epithelial cells to convert to motile mesenchymal cells, promoting carcinoma invasion. The expression levels of Vimentin, the transcription factor of EMT, and tight junction protein Claudin-5, were significantly diminished in the SNX27 knockdown cells. The expression of PCNA, the cell proliferation marker, was increased in SNX27-KD cells transfected with E-cadherin siRNA. In a xenograft nude mouse model, we found that knockdown of SNX27 significantly inhibited tumor growth. The tumors from mice with SNX27-KD cells showed less proliferation compared to tumors from mice injected with wildtype cells. The increase in E-cadherin and β-catenin and decrease in Vimentin and Claudin-5 were observed in tumors of mice injected with SNX27-KD cells.

CONCLUSIONS

Our data have demonstrated that SNX27 plays a crucial role in tumor growth in vitro and in vivo.

Characterization of the molecular changes associated with the overexpression of a novel epithelial cadherin splice variant mRNA in a breast cancer model using proteomics and bioinformatics approaches: identification of changes in cell metabolism and an increased expression of lactate dehydrogenase B

Background

Breast cancer (BC) is the most common female cancer and the leading cause of cancer death in women worldwide. Alterations in epithelial cadherin (E-cadherin) expression and functions are associated to BC, but the underlying molecular mechanisms have not been fully elucidated. We have previously reported a novel human E-cadherin splice variant (E-cadherin variant) mRNA. Stable transfectants in MCF-7 human BC cells (MCF7Ecadvar) depicted fibroblast-like cell morphology, E-cadherin wild-type downregulation, and other molecular changes characteristic of the epithelial-to-mesenchymal transition process, reduced cell-cell adhesion, and increased cell migration and invasion. In this study, a two-dimensional differential gel electrophoresis (2D-DIGE) combined with mass spectrometry (MS) protein identification and bioinformatics analyses were done to characterize biological processes and canonical pathways affected by E-cadherin variant expression.

Results

By 2D-DIGE and MS analysis, 50 proteins were found differentially expressed (≥ Δ1.5) in MCF7Ecadvar compared to control cells. Validation of transcript expression was done in the ten most overexpressed and underexpressed proteins. Bioinformatics analyses revealed that 39 of the 50 proteins identified had been previously associated to BC. Moreover, metabolic processes were the most affected, and glycolysis the canonical pathway most altered. The lactate dehydrogenase B (LDHB) was the highest overexpressed protein, and transcript levels were higher in MCF7Ecadvar than in control cells. In agreement with these findings, MCF7Ecadvar conditioned media had lower glucose and higher lactate levels than control cells. MCF7Ecadvar cell treatment with 5 mM of the glycolytic inhibitor 2-deoxy-glucose led to decreased cell viability, and modulation of LDHB expression in MCF7Ecadvar cells with a specific small interfering RNA resulted in decreased cell proliferation. Finally, a positive association between expression levels of the E-cadherin variant and LDHB transcripts was demonstrated in 21 human breast tumor tissues, and breast tumor samples with higher Ki67 expression showed higher LDHB mRNA levels.

Conclusions

Results from this investigation contributed to further characterize molecular changes associated to the novel E-cadherin splice variant expression in BC cells. They also revealed an association between expression of the novel variant and changes related to BC progression and aggressiveness, in particular those associated to cell metabolism.

Long noncoding RNA DLX6-AS1 promotes tumorigenesis by modulating miR-497-5p/FZD4/FZD6/Wnt/β-catenin pathway in pancreatic cancer

Background

Long noncoding RNAs (lncRNAs) are abnormally expressed in various human tumors and play an important role in multiple tumorigeneses, including pancreatic cancer (PC).

Materials and methods

The present study was designed to evaluate the role of lncRNA DLX6-AS1 in tumorigenesis of PC. The expression of DLX6-AS1 and its effect on proliferation, apoptosis, migration, and invasion was investigated in vitro. Its effect on tumor growth and metastasis in vivo and its potential targets were also examined.

Results

We observed that DLX6-AS1 was highly expressed in PC tissues and PC cell lines, and was negatively correlated with the survival of PC patients. We found that overexpression of DLX6-AS1 promoted proliferation, migration, and invasion of PC cells, inhibited apoptosis, increased Bcl-2, cyclin D1, and MMP-2 expression, and decreased cleaved caspase 3, p27, and E-cadherin expression in PC cells. In addition, overexpression of DLX6-AS1 promoted PC growth by increasing tumor volume and weight and increasing the number of liver and lung metastatic foci. Knockdown of DLX6-AS1 showed an opposite effect in all the experiments. miR-497-5p was demonstrated to be a direct target of DLX6-AS1 and was regulated by DLX6-AS1. We also demonstrated that miR-497-5p targeted FZD4 and FZD6 and decreased their expression. miR-497-5p mimics also decreased the expression of FZD4, FZD6, and β-catenin; the expression of FZD4 or FZD6 was reversed by the overexpression of vectors FZD4 or FZD6, respectively, while the expression of β-catenin was reversed by either vector. Finally, the effect of DLX6-AS1 on proliferation, cell cycle, migration, invasion, and apoptosis of cells and expression of FZD4, FZD6, and β-catenin was neutralized by overexpression of vectors of miR-497-5p, FZD4, or FZD6, totally or partially.

Conclusion

Collectively, these findings suggested that DLX6-AS1/miR-497-5p/FZD4/FZD6/Wnt/β-catenin signaling pathway is involved in the pathogenesis of PC, and DLX6-AS1 could be a potential biomarker and target for PC treatment.

A 3D microvascular network model to study the impact of hypoxia on the extravasation potential of breast cell lines

Hypoxia is a common feature of the tumor microenvironment. Accumulating evidence has demonstrated hypoxia to be an important trigger of tumor cell invasion or metastasizes via hypoxia-signaling cascades, including hypoxia-inducible factors (HIFs). Microfluidic model can be a reliable in vitro tool for systematically interrogating individual factors and their accompanying downstream effects, which may otherwise be difficult to study in complex tumor tissues. Here, we used an in vitro model of microvascular networks in a microfluidic chip to measure the extravasation potential of breast cell lines subjected to different oxygen conditions. Through the use of HIF-1α knock-down cell lines, we also validated the importance of HIF-1α in the transmigration ability of human breast cell lines. Three human breast cell lines derived from human breast tissues (MCF10A, MCF-7 and MDA-MB-231) were used in this study to evaluate the role of hypoxia in promoting metastasis at different stages of cancer progression. Under hypoxic conditions, HIF-1α protein level was increased, and coincided with changes in cell morphology, viability and an elevated metastatic potential. These changes were accompanied by an increase in the rate of extravasation compared to normoxia (21% O₂). siRNA knockdown of HIF-1α in hypoxic tumors significantly decreased the extravasation rates of all the cell lines tested and may have an effect on the function of metastatic and apoptotic-related cellular processes.

Association of CDH1 and TERT Single-Nucleotide Polymorphisms with Susceptibility to Familial Breast Cancer Risk

Breast cancer (BC) is a multistep disease that is thought to result from an interaction between genetic background and environmental factors. In Iran, one of the strongest risk factors for developing BC is a positive family history of the disease. Recently, various polymorphisms of E-cadherin (CDH1) and TERT have been found to be associated with increased BC risk worldwide. This study aimed to analyze the association of CDH1 and TERT single-nucleotide polymorphisms with susceptibility to familial BC (FBC) risk in the Iranian patients. One hundred five patients with FBC and 110 non-FBC (NFBC) were genotyped to elucidate the potential association between CDH1 rs5030625 polymorphism and TERT rs2736098 polymorphism by polymerase chain reaction-restriction fragment length polymorphism. Then, results were evaluated by electrophoresis and Epi Info(™) 2012 software. A significant association was found between CDH1 rs5030625 GAGA genotype and FBC risk. Compared with the control group, the FBC patients had a lower frequency of GG genotype (69% vs. 85%) and a higher frequency of GAGA (5% vs. 2%, P < 0.02). Furthermore, the patients with FBC had a lower frequency of TERT rs2736098 GG genotype (38% vs. 49%, P = 0.001) and a higher frequency of rs2736098 AA genotype (12% vs. 5%, P = 0.001) compared with the NFBC. In contrast, the TERT rs2736098 GG genotype potentially increased the recurring risk of FBC (odds ratio = 3.17, P < 0.01). Allele genotypic frequencies in the FBC patients differed from those of the controls. Interestingly, tumors in FBC patients with rs2736098 GG genotype and rs5030625 GAGA exhibited higher mitotic activity, higher grade, lower estrogen receptor, and progesterone receptor than the other genotypes. In conclusion, CDH1 rs5030625 GAGA genotype and TERT rs2736098 GG genotype in combination with clinical parameters may be prognostic factors rather than susceptibility factors during the progression of FBC.

Potential clinically useful prognostic biomarkers in triple-negative breast cancer: preliminary results of a retrospective analysis

Background

Triple-negative breast cancer (TNBC) has a poor prognosis, even in its early stages. In the absence of postoperative targeted treatments, intensive adjuvant chemotherapy regimens are proposed. For those favorable histologies, such as apocrine and adenoid cystic carcinoma, which frequently belong to TNBC, aggressive treatments are unnecessary.

Patients and methods

We retrospectively analyzed 631 cases of breast cancer, primary operated curatively, and followed up at our institution for at least 36 months to identify the bio-markers assessable by immunohistochemistry, to be proposed as prognostic score for tailoring adjuvant treatment to TNBC patients.

Results

The triple-negative phenotype was found in 85 patients (13.5%). Over a mean followup of 55.7 months, relapses occurred in 106 patients (16.8%), of which 18 (2.8%) were TNBC. Recurrence was directly correlated with Ki67 and cytokeratin 5/6 (CK5/6) immunoreactivity in all breast cancer patients (P=0.005), but only marginally with CK5/6 and epithelial cadherin (E-cad) expression in TNBC patients (P=0.07). Mean event-free survival (EFS) in TNBC patients was 85.52 months compared with 100.4 months in non-TNBC patients (P=0.228). The EFS of CK5/6-negative triple-negative patients was 68.84 months compared with 98.84 months in those who were CK5/6 positive (HR =5.08; P=0.038). EFS differed among patients identified as double-positive for E-cad and CK5/6 (83.87 months), those expressing E-cad or CK5/6 (64.23 months), and those negative for both biomarkers (39.64 months).

Conclusion

These preliminary results suggest that CK5/6 and E-cad are possible core biomarkers for a cost-effective prognostic evaluation of primary operable TNBC patients.

Role of hypoxia-induced exosomes in tumor biology

Purpose

Hypoxia is a major regulator of angiogenesis and always influences the release of exosomes in various types of tumors. The present review aimed to assess the role of hypoxia-induced exosomes in the tumor biology.

Methods

The relevant publications were retrieved from PubMed using keywords such as hypoxia, exosome, extracellular vesicles, tumor, cancer, and other similar terms.

Results

Recent studies have shown that cancer cells produce more exosomes under hypoxic conditions than do parental cells under normoxic conditions. The secretion and function of exosomes could be influenced by hypoxia in various types of cancer. Hypoxia-induced exosomes play critical roles in tumor angiogenesis, invasion, metastasis, and the immune system.

Conclusions

These findings provide new insights into the complex networks underlying cellular and genomic regulation in response to hypoxia and might provide novel and specific targets for future therapies.

Downregulation of GEP100 Improved the Growth Inhibition Effect of Erlotinib Through Modulating Mesenchymal Epithelial Transition Process in Pancreatic Cancer

OBJECTIVE

The epidermal growth factor receptor is overexpressed in the majority of pancreatic cancer. Epidermal growth factor receptor tyrosine kinase inhibitor erlotinib was approved to treat patients combining with gemcitabine. However, the sensitivity is low. Here, we try to reveal the regulatory role of guanine nucleotide exchange protein 100 (GEP100) in erlotinib sensitivity.

METHODS

We investigated the correlation between GEP100 expression and sensitivity to erlotinib in different pancreatic cancer cell lines, followed by examination of the effect of GEP100 on erlotinib sensitivity by establishing the stable knocked-down cell line. The expression level of epithelial mesenchymal transition-related protein was examined by Western blot, and the regulatory mechanism was investigated by short hairpin RNA. Xenograft experiment was also performed in nude mice.

RESULTS

We identified a significant correlation between sensitivity to erlotinib and expression of GEP100. GEP100 downregulation increased its sensitivity to erlotinib. E-cadherin short hairpin RNA treatment inhibited this sensitivity. Immunohistochemical staining showed a mutual exclusive expression pattern of GEP100 and E-cadherin in human pancreatic cancer tissues. Xenograft showed that downregulation of GEP100 enhanced the growth inhibition of erlotinib in nude mice.

CONCLUSIONS

Our results suggested that GEP100 and E-cadherin have the predictive value for responsiveness to erlotinib in pancreatic cancer.

Histone Deacetylases as New Therapeutic Targets in Triple-negative Breast Cancer: Progress and Promises

Triple-negative breast cancer (TNBC) lacks expression of estrogen receptor (ER), progesterone receptor (PR) and HER2 gene. It comprises approximately 15-20% of breast cancers (BCs). Unfortunately, TNBC's treatment continues to be a clinical problem because of its relatively poor prognosis, its aggressiveness and the lack of targeted therapies, leaving chemotherapy as the mainstay of treatment. It is essential to find new therapies against TNBC, in order to surpass the resistance and the invasiveness of already existing therapies. Given the fact that epigenetic processes control both the initiation and progression of TNBC, there is an increasing interest in the mechanisms, molecules and signaling pathways that participate at the epigenetic modulation of genes expressed in carcinogenesis. The acetylation of histone proteins provokes the transcription of genes involved in cell growth, and the expression of histone deacetylases (HDACs) is frequently up-regulated in many malignancies. Unfortunately, in the field of BC, HDAC inhibitors have shown limited effect as single agents. Nevertheless, their use in combination with kinase inhibitors, autophagy inhibitors, ionizing radiation, or two HDAC inhibitors together is currently being evaluated. HDAC inhibitors such as suberoylanilidehydroxamic acid (SAHA), sodium butyrate, mocetinostat, panobinostat, entinostat, YCW1 and N-(2-hydroxyphenyl)-2-propylpentanamide have shown promising therapeutic outcomes against TNBC, especially when they are used in combination with other anticancer agents. More studies concerning HDAC inhibitors in breast carcinomas along with a more accurate understanding of the TNBC's pathobiology are required for the possible identification of new therapeutic strategies.

Erythropoietin drives breast cancer progression by activation of its receptor EPOR

Breast cancer is a leading cause of cancer-related deaths. Anemia is common in breast cancer patients and can be treated with blood transfusions or with recombinant erythropoietin (EPO) to stimulate red blood cell production. Clinical studies have indicated decreased survival in some groups of cancer patients treated with EPO. Numerous tumor cells express the EPO receptor (EPOR), posing a risk that EPO treatment would enhance tumor growth, but the mechanisms involved in breast tumor progression are poorly understood.

Here, we have examined the functional role of the EPO-EPOR axis in pre-clinical models of breast cancer. EPO induced the activation of PI3K/AKT and MAPK pathways in human breast cancer cell lines. EPOR knockdown abrogated human tumor cell growth, induced apoptosis through Bim, reduced invasiveness, and caused downregulation of MYC expression. EPO-induced MYC expression is mediated through the PI3K/AKT and MAPK pathways, and overexpression of MYC partially rescued loss of cell proliferation caused by EPOR downregulation. In a xenotransplantation model, designed to simulate recombinant EPO therapy in breast cancer patients, knockdown of EPOR markedly reduced tumor growth.

Thus, our experiments in vitro and in vivo demonstrate that functional EPOR signaling is essential for the tumor-promoting effects of EPO and underline the importance of the EPO-EPOR axis in breast tumor progression.