Epithelial-mesenchymal transition in cancer: parallels between normal development and tumor progression

Understanding the effect of mechanical forces on ovarian cancer progression

OBJECTIVE

Mechanical forces including tension, compression, and shear stress are increasingly implicated in tumor progression and metastasis. Understanding the mechanisms behind epithelial ovarian cancer (EOC) progression and metastasis is critical, and this study aimed to elucidate the effect of oscillatory and constant tension on EOC.

METHODS

SKOV-3 and OVCAR-8 EOC cell lines were placed under oscillatory tension for 3 days and compared to cells placed under no tension. Cell proliferation, migration, and invasion were analyzed while RNAseq and Western Blots helped investigate the biological mechanisms underlying the increasingly aggressive state of the experimental cells. Finally, in vivo experiments using SCID mice assisted in confirming the in vitro results.

RESULTS

Oscillatory tension (OT) and constant tension (CT) significantly increased SKOV-3 proliferation, while OT caused a significant increase in proliferative genes, migration, and invasion in this cell line. CT did not cause significant increases in these areas. Neither OT nor CT increased proliferation or invasion in OVCAR-8 cells, while both tension types significantly increased cellular migration. Two proteins involved in metastasis, E-cadherin and Snail, were both significantly affected by OT in both cell lines, with E-cadherin levels decreasing and Snail levels increasing. In vivo, tumor growth and weight for both cell types were significantly increased, and ascites development was significantly higher in the experimental OVCAR-8 group than in the control group.

CONCLUSIONS

This study found that mechanical forces are influential in EOC progression and metastasis. Further analysis of downstream mechanisms involved in EOC metastasis will be critical for improvements in EOC treatment.

Repeated Irradiation with γ-Ray Induces Cancer Stemness through TGF-β-DLX2 Signaling in the A549 Human Lung Cancer Cell Line

Cancer stem cells (CSCs) play an important role in cancer recurrence and metastasis. It is suggested that the CSC properties in heterogeneous cancer cells can be induced by ionizing radiation (IR). This study investigated the role of DLX2 in the radioresistance and CSC properties induced by IR in NSCLC cancer cells. Here, A549 cells were exposed to fractionated irradiation at a cumulative dose of 52 Gy (4 Gy × 13 times) for a generation of radioresistant cells. After fractionated irradiation, surviving A549 cells exhibited resistance to IR and enhanced expression of various cancer stem cell markers. They also showed upregulation of mesenchymal molecular markers and downregulation of epithelial molecular markers, correlating with an increase in the migration and invasion. Fractionated irradiation triggered the secretion of TGF-β1 and DLX2 expression. Interestingly, the increased DLX2 following fractionated irradiation seemed to induce the expression of the gene for the EGFR-ligand betacellulin via Smad2/3 signaling. To contrast, DLX2 knockdown dramatically decreased the expression of CSC markers, migration, and proliferation. Moreover, A549 cells expressing DLX2 shRNA formed tumors with a significantly smaller volume compared to those expressing control shDNA in a mouse xenograft assay. These results suggest that DLX2 overexpression in surviving NSCLC cancer cells after fractionated IR exposure is involved in the cancer stemness, radioresistance, EMT, tumor survival, and tumorigenic capability.

A review: hippo signaling pathway promotes tumor invasion and metastasis by regulating target gene expression

BACKGROUND

The Hippo pathway is widely considered to inhibit cell growth and play an important role in regulating the size of organs. However, recent studies have shown that abnormal regulation of the Hippo pathway can also affect tumor invasion and metastasis. Therefore, finding out how the Hippo pathway promotes tumor development by regulating the expression of target genes provides new ideas for future research on targeted drugs that inhibit tumor progression.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were systematically searched.

RESULTS

The search strategy identified 1892 hits and 196 publications were finally included in this review. As the core molecule of the Hippo pathway, YAP/TAZ are usually highly expressed in tumors that undergo invasion and migration and are accompanied by abnormally strong nuclear metastasis. Through its interaction with nuclear transcription factors TEADs, it directly or indirectly regulates and the expressions of target genes related to tumor metastasis and invasion. These target genes can induce the formation of invasive pseudopodia in tumor cells, reduce intercellular adhesion, degrade extracellular matrix (ECM), and cause epithelial-mesenchymal transition (EMT), or indirectly promote through other signaling pathways, such as mitogen-activated protein kinases (MAPK), TGF/Smad, etc, which facilitate the invasion and metastasis of tumors.

CONCLUSION

This article mainly introduces the research progress of YAP/TAZ which are the core molecules of the Hippo pathway regulating related target genes to promote tumor invasion and metastasis. Focus on the target genes that affect tumor invasion and metastasis, providing the possibility for the selection of clinical drug treatment targets, to provide some help for a more in-depth study of tumor invasion and migration mechanism and the development of clinical drugs.

EIF5A2 controls ovarian tumor growth and metastasis by promoting epithelial to mesenchymal transition via the TGFβ pathway

BACKGROUND

Epithelial to mesenchymal transition (EMT) contributes to tumor metastasis and chemoresistance. Eukaryotic initiation factor 5A2 (EIF5A2) is highly expressed in a variety of human cancers but rarely expressed in normal tissues. While EIF5A2 has oncogenic activity in several cancers and contributes to tumor metastasis, its role in ovarian cancer is unknown. In this study, we investigate whether EIF5A2 contributes to ovarian tumor metastasis by promoting EMT.

METHODS

To investigate the role of EIF5A2, we knocked out (KO) EIF5A2 using lentiviral CRISPR/Cas9 nickase in high invasive SKOV3 and OVCAR8 cells and overexpressed EIF5A2 in low invasive OVCAR3 cells using lentiviral vector. Cell proliferation, migration and invasion was examined in vitro ovarian cancer cells and tumor metastasis was evaluated in vivo using orthotopic ovarian cancer mouse models.

RESULTS

Here we report that EIF5A2 is highly expressed in ovarian cancers and associated with patient poor survival. Lentiviral CRISPR/Cas9 nickase vector mediated knockout (KO) of EIF5A2 inhibits epithelial to mesenchymal transition (EMT) in SKOV3 and OVCAR8 ovarian cancer cells that express high levels of EIF5A2. In contrast, overexpression of EIF5A2 promotes EMT in OVCAR3 epithelial adenocarcinoma cells that express relatively low EIF5A2 levels. KO of EIF5A2 in SKOV3 and OVCAR8 cells inhibits ovarian cancer cell migration and invasion, while its overexpression promotes cell migration and invasion in OVCAR3 adenocarcinoma cells. We further demonstrate that EIF5A2 promotes EMT by activating the TGFβ pathway and KO of EIF5A2 inhibits ovarian tumor growth and metastasis in orthotopic ovarian cancer mouse models.

CONCLUSION

Our results indicate that EIF5A2 is an important controller of ovarian tumor growth and metastasis by promoting EMT and activating the TGFβ pathway.

hCINAP is potentially a direct target gene of HIF-1 and is required for hypoxia-induced EMT and apoptosis in cervical cancer cells

The early metastasis of cervical cancer is a multistep process requiring the cancer cells to adapt to the signal input from different tissue environments, including hypoxia. Hypoxia-induced epithelial-to-mesenchymal transition (EMT) plays a critical role in the ability to invade surrounding tissues. However, the molecular mechanisms underlying EMT in cervical cancer remain to be elucidated. Herein, we show that hypoxia-inducible factor-1alpha (HIF-1α) and aryl hydrocarbon receptor nuclear translocator (ARNT) are recruited to the human coilin-interacting nuclear ATPase protein (hCINAP) promoter and initiate hCINAP expression in hypoxia. Ablation of hCINAP decreased the migratory capacity and EMT of cervical cancer cells under hypoxic conditions. Furthermore, hCINAP regulated EMT through the Akt–mTOR signaling pathway, and inhibits hypoxia-induced p53-dependent apoptosis. Our data collectively show that hCINAP may have essential roles in the metastasis of cervical cancer and could be a potential target for curing cervical cancer.

TGFβ signaling networks in ovarian cancer progression and plasticity

Epithelial ovarian cancer (EOC) is a leading cause of cancer-related death in women. Late-stage diagnosis with significant tumor burden, accompanied by recurrence and chemotherapy resistance, contributes to this poor prognosis. These morbidities are known to be tied to events associated with epithelial-mesenchymal transition (EMT) in cancer. During EMT, localized tumor cells alter their polarity, cell-cell junctions, cell-matrix interactions, acquire motility and invasiveness and an exaggerated potential for metastatic spread. Key triggers for EMT include the Transforming Growth Factor-β (TGFβ) family of growth factors which are actively produced by a wide array of cell types within a specific tumor and metastatic environment. Although TGFβ can act as either a tumor suppressor or promoter in cancer, TGFβ exhibits its pro-tumorigenic functions at least in part via EMT. TGFβ regulates EMT both at the transcriptional and post-transcriptional levels as outlined here. Despite recent advances in TGFβ based therapeutics, limited progress has been seen for ovarian cancers that are in much need of new therapeutic strategies. Here, we summarize and discuss several recent insights into the underlying signaling mechanisms of the TGFβ isoforms in EMT in the unique metastatic environment of EOCs and the current therapeutic interventions that may be relevant.

MACC1 Is Associated With Epithelial-Mesenchymal Transition and Can Predict Poor Prognosis in Nasopharyngeal Carcinoma

Background

Given the reported correlation between the oncogene metastasis-associated in colon cancer 1 (MACC1) and nasopharyngeal carcinoma (NPC), as well as between MACC1 and epithelial–mesenchymal transition (EMT), we speculated that EMT is a likely causative link between MACC1 expression and poor NPC prognosis. Thus, we aim to clarify the relationship between MACC1 and EMT in NPC prognosis.

Material and Methods

We performed immunohistochemical examination of tissue sections from 128 NPC patients that were divided into six groups corresponding to high and low protein expression of MACC1 and two EMT-related proteins, vimentin and E-cadherin, and Kaplan–Meier (KM) survival analyses were performed.

Results

KM survival analysis showed that upregulation of MACC1 and vimentin and downregulation of E-cadherin were significantly associated with reduced survival in NPC. Short hairpin RNA (shRNA) interference and immunoblotting in the NPC cell line HNE-1 led to increased E-cadherin but decreased vimentin levels. MACC1 overexpression was significantly correlated with poor 5-year overall survival, metastasis-free survival, and disease-free survival (P<0.05) but not with poor relapse-free survival (P>0.05). Univariate analyses revealed that MACC1, E-cadherin, and vimentin levels along with T and N tumor classifications and cancer staging are significant prognostic factors of NPC (P<0.05).

Conclusion

Our findings showed the association between MACC1 and EMT in NPC malignancy and support the role of MACC1 as a prognostic biomarker and molecular target for NPC treatment.

A novel 3D atomistic-continuum cancer invasion model: In silico simulations of an in vitro organotypic invasion assay

We develop a three-dimensional genuinely hybrid atomistic-continuum model that describes the invasive growth dynamics of individual cancer cells in tissue. The framework explicitly accounts for phenotypic variation by distinguishing between cancer cells of an epithelial-like and a mesenchymal-like phenotype. It also describes mutations between these cell phenotypes in the form of epithelial-mesenchymal transition (EMT) and its reverse process mesenchymal-epithelial transition (MET). The proposed model consists of a hybrid system of partial and stochastic differential equations that describe the evolution of epithelial-like and mesenchymal-like cancer cells, respectively, under the consideration of matrix-degrading enzyme concentrations and the extracellular matrix density. With the help of inverse parameter estimation and a sensitivity analysis, this three-dimensional model is then calibrated to an in vitro organotypic invasion assay experiment of oral squamous cell carcinoma cells.

The Epithelial-Mesenchymal Transcription Factor SNAI1 Represses Transcription of the Tumor Suppressor miRNA let-7 in Cancer

Simple Summary

When cells undergo epithelial–mesenchymal transition (EMT) they gain characteristics of stem cells. We investigated the mechanism by which the EMT transcription factor SNAI1 induces stem cell features. In these studies, we observed that SNAI1 represses a microRNA that maintains differentiation, let-7. This microRNA is lost in cancer, and its loss correlates with poor prognosis. In breast, pancreatic, and ovarian cancer cell lines the cell stemness in increased by SNAI1 overexpression and reduced by SNAI1 knockdown. We extended the ovarian cancer results to patient-derived cells, and to a mouse xenograft model. In mice, we used nanoparticles to deliver small RNAs (RNAi) targeting SNAI1, resulting in restoration of let-7 levels, inhibition of stemness, and reduced tumor burden. Our studies validate nanoparticle-delivered RNAi targeting SNAI1 as a clinically relevant approach.

Abstract

We aimed to determine the mechanism of epithelial–mesenchymal transition (EMT)-induced stemness in cancer cells. Cancer relapse and metastasis are caused by rare stem-like cells within tumors. Studies of stem cell reprogramming have linked let-7 repression and acquisition of stemness with the EMT factor, SNAI1. The mechanisms for the loss of let-7 in cancer cells are incompletely understood. In four carcinoma cell lines from breast cancer, pancreatic cancer, and ovarian cancer and in ovarian cancer patient-derived cells, we analyzed stem cell phenotype and tumor growth via mRNA, miRNA, and protein expression, spheroid formation, and growth in patient-derived xenografts. We show that treatment with EMT-promoting growth factors or SNAI1 overexpression increased stemness and reduced let-7 expression, while SNAI1 knockdown reduced stemness and restored let-7 expression. Rescue experiments demonstrate that the pro-stemness effects of SNAI1 are mediated via let-7. In vivo, nanoparticle-delivered siRNA successfully knocked down SNAI1 in orthotopic patient-derived xenografts, accompanied by reduced stemness and increased let-7 expression, and reduced tumor burden. Chromatin immunoprecipitation demonstrated that SNAI1 binds the promoters of various let-7 family members, and luciferase assays revealed that SNAI1 represses let-7 transcription. In conclusion, the SNAI1/let-7 axis is an important component of stemness pathways in cancer cells, and this study provides a rationale for future work examining this axis as a potential target for cancer stem cell-specific therapies.

MicroRNA Signature of Epithelial-Mesenchymal Transition in Group B Streptococcal Infection of the Placental Chorioamniotic Membranes

BACKGROUND

Infection-induced preterm birth is a major cause of neonatal mortality and morbidity and leads to preterm premature rupture of placental chorioamniotic membranes. The loss of amniotic epithelial cells and tensile strength preceding membrane rupture is poorly understood. We hypothesized that intrauterine bacterial infection induces changes in microRNA (miRNA) expression, leading to amniotic epithelial cell loss and membrane weakening.

METHODS

Ten pregnant pigtail macaques received choriodecidual inoculation of either group B Streptococcus (GBS) or saline (n = 5/group). Placental chorioamniotic membranes were studied using RNA microarray and immunohistochemistry. Chorioamniotic membranes from women with preterm premature rupture of membranes (pPROM) and normal term pregnancies were studied using transmission electron microscopy.

RESULTS

In our model, an experimental GBS infection was associated with changes in the miRNA profile in the chorioamniotic membranes consistent with epithelial to mesenchymal transition (EMT) with loss of epithelial (E-cadherin) and gain of mesenchymal (vimentin) markers. Similarly, loss of desmosomes (intercellular junctions) was seen in placental tissues from women with pPROM.

CONCLUSIONS

We describe EMT as a novel mechanism for infection-associated chorioamniotic membrane weakening, which may be a common pathway for many etiologies of pPROM. Therapy based on anti-miRNA targeting of EMT may prevent pPROM due to perinatal infection.

Aggressiveness of 4T1 breast cancer cells hampered by Wnt production-2 inhibitor nanoparticles: An in vitro study

Polymeric nanoparticles may enable delivery of drugs with lower systemic toxicity to solid tumors. Wnt signaling are evolutionary conserved pathways, involved in proliferation and fate decisions. Alterations in Wnt signaling play a pivotal role in various cancer types that promote cancer initiation, growth, metastasis and drug resistance. We designed a new strategy to allow an efficient targeting of both the canonical and the non-canonical Wnt pathways using nanoparticles loaded with inhibitor of Wnt productions-2 (IWP-2). This hydrophobic drug was successfully co-assembled into NPs composed of poly gamma-glutamic acid and a cationic and amphiphilic b-sheet peptide. Aggressive 4T1 breast cancer cells that were treated with IWP-2 loaded NPs gained a significant decrease in tumorigenic capacities attributed to improved IWP solubility, cellular uptake and efficacy.

The FAM3C locus that encodes interleukin-like EMT inducer (ILEI) is frequently co-amplified in MET-amplified cancers and contributes to invasiveness

BACKGROUND

Gene amplification of MET, which encodes for the receptor tyrosine kinase c-MET, occurs in a variety of human cancers. High c-MET levels often correlate with poor cancer prognosis. Interleukin-like EMT inducer (ILEI) is also overexpressed in many cancers and is associated with metastasis and poor survival. The gene for ILEI, FAM3C, is located close to MET on chromosome 7q31 in an amplification "hotspot", but it is unclear whether FAMC3 amplification contributes to elevated ILEI expression in cancer. In this study we have investigated FAMC3 copy number gain in different cancers and its potential connection to MET amplifications.

METHODS

FAMC3 and MET copy numbers were investigated in various cancer samples and 200 cancer cell lines. Copy numbers of the two genes were correlated with mRNA levels, with relapse-free survival in lung cancer patient samples as well as with clinicopathological parameters in primary samples from 49 advanced stage colorectal cancer patients. ILEI knock-down and c-MET inhibition effects on proliferation and invasiveness of five cancer cell lines and growth of xenograft tumors in mice were then investigated.

RESULTS

FAMC3 was amplified in strict association with MET amplification in several human cancers and cancer cell lines. Increased FAM3C and MET copy numbers were tightly linked and correlated with increased gene expression and poor survival in human lung cancer and with extramural invasion in colorectal carcinoma. Stable ILEI shRNA knock-down did not influence proliferation or sensitivity towards c-MET-inhibitor induced proliferation arrest in cancer cells, but impaired both c-MET-independent and -dependent cancer cell invasion. c-MET inhibition reduced ILEI secretion, and shRNA mediated ILEI knock-down prevented c-MET-signaling induced elevated expression and secretion of matrix metalloproteinase (MMP)-2 and MMP-9. Combination of ILEI knock-down and c-MET-inhibition significantly reduced the invasive outgrowth of NCI-H441 and NCI-H1993 lung tumor xenografts by inhibiting proliferation, MMP expression and E-cadherin membrane localization.

CONCLUSIONS

These novel findings suggest MET amplifications are often in reality MET-FAM3C co-amplifications with tight functional cooperation. Therefore, the clinical relevance of this frequent cancer amplification hotspot, so far dedicated purely to c-MET function, should be re-evaluated to include ILEI as a target in the therapy of c-MET-amplified human carcinomas.

The Paradoxical Behavior of microRNA-211 in Melanomas and Other Human Cancers

Cancer initiation, progression, and metastasis leverage many regulatory agents, such as signaling molecules, transcription factors, and regulatory RNA molecules. Among these, regulatory non-coding RNAs have emerged as molecules that control multiple cancer types and their pathologic properties. The human microRNA-211 (MIR211) is one such molecule, which affects several cancer types, including melanoma, glioblastoma, lung adenocarcinomas, breast, ovarian, prostate, and colorectal carcinoma. Previous studies suggested that in certain tumors MIR211 acts as a tumor suppressor while in others it behaves as an oncogenic regulator. Here we summarize the known molecular genetic mechanisms that regulate MIR211 gene expression and molecular pathways that are in turn controlled by MIR211 itself. We discuss how cellular and epigenetic contexts modulate the biological effects of MIR211, which exhibit pleiotropic effects. For example, up-regulation of MIR211 expression down-regulates Warburg effect in melanoma tumor cells associated with an inhibition of the growth of human melanoma cells in vitro, and yet these conditions robustly increase tumor growth in xenografted mice. Signaling through the DUSP6-ERK5 pathway is modulated by MIR211 in BRAFV600E driven melanoma tumors, and this function is involved in the resistance of tumor cells to the BRAF inhibitor, Vemurafenib. We discuss several alternate but testable models, involving stochastic cell-to-cell expression heterogeneity due to multiple equilibria involving feedback circuits, intracellular communication, and genetic variation at miRNA target sties, to reconcile the paradoxical effects of MIR211 on tumorigenesis. Understanding the precise role of this miRNA is crucial to understanding the genetic basis of melanoma as well as the other cancer types where this regulatory molecule has important influences. We hope this review will inspire novel directions in this field.

Systematic investigation of biomarker-like role of ARHGDIB in breast cancer

BACKGROUND

ARHGDIB, a Rho GDP dissociation inhibitor protein, has been reported playing critical roles in regulation of multiple biological responses. However, whether ARHGDIB serves as a valuable biomarker in cancer is little known so far, especially in breast cancer.

OBJECTIVE

In this study, we aimed to investigate the importance of ARHGDIB in breast cancer, including but not limited to biomarker-like role, as well as potential mechanisms.

METHODS

Total 100 breast cancer samples and 100 benign breast disease samples were enrolled and underwent detailed pathological assessment and IHC analysis. Human breast cancer cell lines and epithelial cell line were subjected to siRNA-mediated knock-down, RT-qPCR, western blot, MTT staining, cell cycle assay, transwell analysis respectively.

RESULTS

We observed the expression of ARHGDIB is significantly higher in human breast cancer tissues compared with the benign tissues. ARHGDIB expression was positively correlated with tumor size, lymph node metastasis and TNM stage in breast cancer patients. Moreover, ARHGDIB depletion decreased proliferation, migration and invasion of breast cancer cells. Furthermore, we found ARHGDIB mediated epithelial-mesenchymal transition, and MMP2 is the key downstream effector of ARHGDIB.

CONCLUSIONS

Hence, our results suggested the significance and predictive role of ARHGDIB in breast cancer. High expression of ARHGDIB indicated the poor prognosis for breast cancer patients.

Myeloid cells: Prime drivers of tumor progression

Metastasis is a key step in cancer progression, and was traditionally attributed to the accumulation of genetic and epigenetic changes within individual cancer cells. These changes promoted invasiveness, immune evasion and survival at distant sites. However, recent studies reveal that metastasis is not achieved by the cancer cell in isolation, but requires intervention from the immune system. The myeloid cell population in particular is now implicated in many aspects of metastasis. Here, we bring together the evidence for the importance of various myeloid cell sub-populations throughout the metastatic process, from initiation of cancer cell invasiveness, to priming the tissue site for colonization.

Regulation of valproic acid induced EMT by AKT/GSK3β/β-catenin signaling pathway in triple negative breast cancer

Valproic acid (VPA) is a selective histone deacetylation (HDAC) inhibitor and exerts anti-cancer properties in different types of cancer. The epithelial-to-mesenchymal transition (EMT) mediating by different signaling cascade can be a potential target in aggressive human cancers. Therefore, we aimed to clarified the unravel relationship between AKT/GSK3β/β-catenin signalling pathway and VPA-induced EMT in triple negative breast cancer (TNBC). The cytotoxicity of VPA in MDA-MB-231 TNBC and MCF-10A control cells was evaluated. Alterations in the expression levels of Snail, E-cadherin, AKT, GSK3β, β-catenin were analyzed by RT-PCR. Additionally, Annexin V, cell cycle and wound healing assays were performed. Our results showed that VPA remarkably inhibited the growth of TNBC cell and triggered apoptotic cell death through G0/G1 arrest. Furthermore, VPA increased cell migration and activated the EMT process through significantly increasing Snail expression and in turn downregulation of E-cadherin and GKS3β levels. However, the level of AKT and β-catenin was reduced after treatment of VPA. Our data showed that VPA induced EMT process and cell migration in TNBC cells. However, AKT/GSK3β/β-catenin signaling pathway did not mediate EMT activation.

Multiple roles of HOX proteins in Metastasis: Let me count the ways

Knowledge of the role of HOX proteins in cancer has been steadily accumulating in the last 25 years. They are encoded by 39 HOX genes arranged in 4 distinct clusters, and have unique and redundant function in all types of cancers. Many HOX genes behave as oncogenic transcriptional factors regulating multiple pathways that are critical to malignant progression in a variety of tumors. Some HOX proteins have dual roles that are tumor-site specific, displaying both oncogenic and tumor suppressor function. The focus of this review is on how HOX proteins contribute to growth or suppression of metastasis. The review will cover HOX protein function in the critical aspects of epithelial-mesenchymal transition, in cancer stem cell sustenance and in therapy resistance, manifested as distant metastasis. The emerging role of adiposity in both initiation and progression of metastasis is described. Defining the role of HOX genes in the metastatic process has identified candidates for targeted cancer therapies that may combat the metastatic process. We will discuss potential therapeutic opportunities, particularly in pathways influenced by HOX proteins.

Targeting the cytoskeleton against metastatic dissemination

Cancer is a pathology characterized by a loss or a perturbation of a number of typical features of normal cell behaviour. Indeed, the acquisition of an inappropriate migratory and invasive phenotype has been reported to be one of the hallmarks of cancer. The cytoskeleton is a complex dynamic network of highly ordered interlinking filaments playing a key role in the control of fundamental cellular processes, like cell shape maintenance, motility, division and intracellular transport. Moreover, deregulation of this complex machinery contributes to cancer progression and malignancy, enabling cells to acquire an invasive and metastatic phenotype. Metastasis accounts for 90% of death from patients affected by solid tumours, while an efficient prevention and suppression of metastatic disease still remains elusive. This results in the lack of effective therapeutic options currently available for patients with advanced disease. In this context, the cytoskeleton with its regulatory and structural proteins emerges as a novel and highly effective target to be exploited for a substantial therapeutic effort toward the development of specific anti-metastatic drugs. Here we provide an overview of the role of cytoskeleton components and interacting proteins in cancer metastasis with a special focus on small molecule compounds interfering with the actin cytoskeleton organization and function. The emerging involvement of microtubules and intermediate filaments in cancer metastasis is also reviewed.

Berbamine Suppresses the Progression of Bladder Cancer by Modulating the ROS/NF-κB Axis

Berbamine (BBM), one of the bioactive ingredients extracted from Berberis plants, has attracted intensive attention because of its significant antitumor activity against various malignancies. However, the exact role and potential molecular mechanism of berbamine in bladder cancer (BCa) remain unclear. In the present study, our results showed that berbamine inhibited cell viability, colony formation, and proliferation. Additionally, berbamine induced cell cycle arrest at S phase by a synergistic mechanism involving stimulation of P21 and P27 protein expression as well as downregulation of CyclinD, CyclinA2, and CDK2 protein expression. In addition to suppressing epithelial-mesenchymal transition (EMT), berbamine rearranged the cytoskeleton to inhibit cell metastasis. Mechanistically, the expression of P65, P-P65, and P-IκBα was decreased upon berbamine treatment, yet P65 overexpression abrogated the effects of berbamine on the proliferative and metastatic potential of BCa cells, which indicated that berbamine attenuated the malignant biological activities of BCa cells by inhibiting the NF-κB pathway. More importantly, berbamine increased the intracellular reactive oxygen species (ROS) level through the downregulation of antioxidative genes such as Nrf2, HO-1, SOD2, and GPX-1. Following ROS accumulation, the intrinsic apoptotic pathway was triggered by an increase in the ratio of Bax/Bcl-2. Furthermore, berbamine-mediated ROS accumulation negatively regulated the NF-κB pathway to a certain degree. Consistent with our in vitro results, berbamine successfully inhibited tumor growth and blocked the NF-κB pathway in our xenograft model. To summarize, our data demonstrated that berbamine exerts antitumor effects via the ROS/NF-κB signaling axis in bladder cancer, which provides a basis for further comprehensive study and presents a potential candidate for clinical treatment strategies against bladder cancer.

MicroRNA-377-3p targeting MMP-16 inhibits ovarian cancer cell growth, invasion, and interstitial transition

Background

To evaluate role of microRNA (miRNA)-377-3p on the remission of ovarian cancer (OC) cell proliferation, invasion, and interstitial transition in vivo and vitro.

Methods

SKOV3 cells were used as the object of in vitro research and four-week-old immunodeficient BABL/c female nude mice were used to form the xenograft model. Cell models were constructed by transfecting NC mimics, miR-377 mimic, plasmid cloning DNA (pcDNA), pc-matrix metalloproteinase (MMP)-16, or co-transfecting miR-377 mimic and pc-MMP-16. TargetScan software was used to predict the targeting relationship between miRNA-377-3p and MMP-16 in OC cells. The combination of miRNA-377-3p and MMP-16 was detected by dual luciferase report experiment. miRNA expression levels of miRNA-377-3p and MMP-16 in each transfection group cells were detected by reverse transcription-polymerase chain reaction (RT-PCR). The proliferation of SKOV3 cells were assessed by 5-ethynyl-2'-deoxyuridine (EdU) staining and microtubule formation, while the invasion ability of SKOV3 cells was detected by Transwell assay. Protein expression levels of MMP-16, survivin, Ki67, vascular endothelial growth factor (VEGF), E-cadherin, and N-cadherin were detected by Western blot (WB), and the positive cells of Ki67 and VEGF were detected by immunohistochemistry (IHC).

Results

MMP-16 overexpression markedly increased the EDU-positive cell percentage, upregulated survivin and Ki67 levels, increased the number of invasive cells per field, and enhanced VEGF and N-cadherin expression. Importantly, co-transfection of miRNA-377-3p and MMP-16 reversed these abnormal phenomena. Xenotransplantation mouse models were formed by injecting SKOV-3 cells subcutaneously. Tumor size, tumor volume, and tumor weight were all reduced in the miR-377-3p mimic–transfected group. The results of IHC indicated that Ki67 and VEGF expression were decreased in the miR-377-3p mimic–transfected group.

Conclusions

These findings indicate that miR-377-3p could be a promising therapeutic agent for OC cell growth, invasion, and interstitial transition with MMP-16 being its likely target.

Metastasis: crosstalk between tissue mechanics and tumour cell plasticity

Despite the fact that different genetic programmes drive metastasis of solid tumours, the ultimate outcome is the same: tumour cells are empowered to pass a series of physical hurdles to escape the primary tumour and disseminate to other organs. Epithelial-to-mesenchymal transition (EMT) has been proposed to drive the detachment of individual cells from primary tumour masses and facilitate the subsequent establishment of metastases in distant organs. However, this concept has been challenged by observations from pathologists and from studies in animal models, in which partial and transient acquisition of mesenchymal traits is seen but tumour cells travel collectively rather than as individuals. In this review, we discuss how crosstalk between a hybrid E/M state and variations in the mechanical aspects of the tumour microenvironment can provide tumour cells with the plasticity required for strategies to navigate surrounding tissues en route to dissemination. Targeting such plasticity provides therapeutic opportunities to combat metastasis.

Profiling of ribose methylations in ribosomal RNA from diffuse large B-cell lymphoma patients for evaluation of ribosomes as drug targets

Cancer cells are addicted to ribosome biogenesis and high levels of translation. Thus, differential inhibition of cancer cells can be achieved by targeting aspects of ribosome biogenesis or ribosome function. Using RiboMeth-seq for profiling of the ∼112 2′-O-Me sites in human ribosomal RNA, we demonstrated pronounced hypomethylation at several sites in patient-derived diffuse large B-cell lymphoma (DLBCL) cell lines with a more severe perturbation in ABC-DLBCL compared to GBC-DLBCL. We extended our analysis to tumor samples from patients and demonstrated significant changes to the ribosomal modification pattern that appeared to consist of cell growth-related as well as tumor-specific changes. Sites of hypomethylation in patient samples are discussed as potential drug targets, using as an example a site in the small subunit (SSU-C1440) located in a ribosomal substructure that can be linked to DLBCL pathogenesis.

lncRNA involvement in cancer stem cell function and epithelial-mesenchymal transitions

Epithelial to mesenchymal transition (EMT) is a cellular process in which cells composing epithelial tissue lose requirements for physical contact with neighboring cells and acquire mesenchymal characteristics consisting of increased migratory and invasive behaviors. EMT is a fundamental process that is required for initial and later events during embryogenesis. Cancer stem cells (CSCs) possess multipotency sufficient for their differentiation into bulk tumor cells and also have the capacity to undergo EMT. When CSCs initiate EMT programs the resulting cancerous mesenchymal cells become invasive and this migratory behavior also poises them for metastatic activity. Long noncoding RNAs (lncRNAs) are functional RNA molecules that do not encode proteins, yet regulate the expression of protein-coding genes through recruitment or sequestration of gene-regulatory proteins and microRNAs. lncRNA exhibit tissue-specific patterns of gene expression during development and specific sets of lncRNAs are also involved in various cancer types. This review considers the interplay between lncRNAs and the biogenesis of CSCs. We also review function of lncRNAs in EMT in CSCs. In addition, we discuss the utility of lncRNAs as biomarkers of cancer progression, and their potential use as therapeutic targets for treatment of cancer.

The O-GalNAcylating enzyme GALNT5 mediates carcinogenesis and progression of cholangiocarcinoma via activation of AKT/ERK signaling

Mucin type O-glycosylation is a posttranslational modification of membrane and secretory proteins. Transferring of N-acetylgalactosamine, the first sugar of O-glycosylation, is catalyzed by one of the 20 isoforms of polypeptide N-acetylgalactosaminyltransferases (GALNTs). In this study, Vicia villosa lectin (VVL), a lectin that recognizes O-GalNAcylated glycans, was used to detect VVL-binding glycans (VBGs) in cholangiocarcinoma (CCA). The elevation of VBGs in tumor tissues of the liver fluke associated with CCA from hamsters and patients was noted. VBGs were detected in hyperplastic/dysplastic bile ducts and CCA but not in normal biliary epithelia and hepatocytes, indicating the association of VBGs with CCA development and progression. GALNT5 was shown to be the major isoform found in human CCA cell lines with high VBG expression. Suppression of GALNT5 expression using siRNA significantly reduced VBG expression, signifying the connection of GALNT5 and VBGs observed. Knocked-down GALNT5 expression considerably inhibited proliferation, migration and invasion of CCA cells. Increased expression of GALNT5 using pcDNA3.1-GALNT5 expression vector induced invasive phenotypes in CCA cells with low GALNT5 expression. Increasing of claudin-1 and decreasing of slug and vimentin expression together with inactivation of Akt/Erk signaling were noted in GALNT5 knocked-down cells. These observations were reversed in GALNT5 over-expressing cells. GALNT5-modulated progression of CCA cells was shown to be, in part, via GALNT5-mediated autocrine/paracrine factors that stimulated activations of Akt/Erk signaling and the epithelial to mesenchymal transition process. GALNT5 and its O-GalNAcylated products may have important roles in promoting progression of CCA and could possibly be novel targets for treatment of metastatic CCA.

HPV-inactive cell populations arise from HPV16-transformed human keratinocytes after p53 knockout

HPV-inactive head and neck and cervical cancers contain HPV DNA but do not express HPV E6/E7. HPV-positive primary head and neck tumors usually express E6/E7, however they may produce HPV-inactive metastases. These observations led to our hypothesis that HPV-inactive cancers begin as HPV-active lesions, losing dependence on E6/E7 expression during progression. Because HPV-inactive cervical cancers often have mutated p53, we investigated whether p53 loss may play a role in the genesis of HPV-inactive cancers. p53 knockout (p53-KO) by CRISPR-Cas9 resulted in a 5-fold reduction of E7 mRNA in differentiation-resistant HPV16 immortalized human keratinocytes (HKc/DR). E7 expression was restored by 5-Aza-2 deoxycytidine in p53 KO lines, suggesting a role of DNA methylation in this process. In-situ hybridization showed that p53 KO lines consist of mixed populations of E6/E7-positive and negative cells. Hence, loss of p53 predisposes HPV16 transformed cells to losing dependence on the continuous expression of HPV oncogenes for proliferation.

Epithelial to Mesenchymal Transition (EMT) in a Laryngeal Squamous Cell Carcinoma of a Horse: Future Perspectives

Simple Summary

Squamous cell carcinoma (SCC) is one of the most common cancers in horses, and it can arise at any site on the skin and mucosae. Recent studies associated equine papillomavirus type 2 (EcPV2) infections with this type of cancers of the oral tract and genitals. Larynx and pharynx are frequently recognized as sites of SCC. In humans, squamous cell carcinoma of the larynx (SCCL) is a common cancer associated with papilloma virus (PV) infection and epithelial to mesenchymal transition (EMT). EMT can occur under different biological conditions, upon the same programmed changes: embryogenesis and organ development fibrosis, wound healing, and cancer metastases. This work reports for the first time in a SCCL of a horse a wide immunohistochemical EMT characterization, by analyzing main epithelial markers (E-cadherin, β-catenin, and pan-cytokeratin AE3/AE1), main mesenchymal markers (N-cadherin and vimentin), and the main EMT-related transcription factors (TWIST-1, ZEB-1, and HIF-1α). This work illustrates an example of tumor cell adaptation during the metastatic process in the equine SCCL, taking also into consideration the potential influence provided by EcPV2 oncoproteins on the EMT process.

Abstract

Squamous cell carcinoma (SCC) is one of the most frequent tumors of skin and muco-cutaneous junctions in the horse. Equine papillomavirus type 2 (EcPV2) has been detected in equine SCC of the oral tract and genitals, and recently also in the larynx. As human squamous cell carcinoma of the larynx (SCCL), it is strongly etiologically associated with high-risk papillomavirus (h-HPV) infection. This study focuses on tumor cells behavior in a naturally occurring tumor that can undergo the so-called epithelial to mesenchymal transition (EMT). A SCCL in a horse was investigated by immunohistochemistry using antibodies against E-cadherin, pan-cytokeratin AE3/AE1, β-catenin, N-cadherin, vimentin, ZEB-1, TWIST, and HIF-1α. EcPV2 DNA detection and expression of oncogenes in SCC were investigated. A cadherin switch and an intermediate filaments rearrangement within primary site tumor cells together with the expression of the EMT-related transcription factors TWIST-1, ZEB-1, and HIF-1α were observed. DNA obtained from the tumor showed EcPV2 positivity, with E2 gene disruption and E6 gene dysregulation. The results suggest that equine SCCL might be a valuable model for studying EMT and the potential interactions between EcPV2 oncoproteins and the EMT process in SCCL.

Identification of EMT-Related Gene Signatures to Predict the Prognosis of Patients With Endometrial Cancer

Background

Endometrial cancer (EC) is one of the most common gynecological cancers. Epithelial–mesenchymal transition (EMT) is believed to be significantly associated with the malignant progression of tumors. However, there is no relevant study on the relationship between EMT-related gene (ERG) signatures and the prognosis of EC patients.

Methods

We extracted the mRNA expression profiles of 543 tumor and 23 normal tissues from The Cancer Genome Atlas database. Then, we selected differentially expressed ERGs (DEERGs) among these mRNAs. Next, univariate and multivariate Cox regression analyses were performed to select the ERGs with predictive ability for the prognosis of EC patients. In addition, risk score models were constructed based on the selected genes to predict patients’ overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS). Finally, nomograms were constructed to estimate the OS and PFS of EC patients, and pan-cancer analysis was performed to further analyze the functions of a certain gene.

Results

Six OS-, ten PFS-, and five DFS-related ERGs were obtained. By constructing the prognostic risk score model, we found that the OS, PFS, and DFS of the high-risk group were notably poorer. Last, we found that AQP5 appeared in all three gene signatures, and through pan-cancer analysis, it was also found to play an important role in immunity in lower grade glioma (LGG), which may contribute to the poor prognosis of LGG patients.

Conclusions

We constructed ERG signatures to predict the prognosis of EC patients using bioinformatics methods. Our findings provide a thorough understanding of the effect of EMT in patients with EC and provide new targets and ideas for individualized treatment, which has important clinical significance.

A practical toolkit to study aspects of the metastatic cascade in vitro

While metastasis - the spread of cancer from the primary location to distant sites in the body - remains the principle cause of cancer death, it is incompletely understood. It is a complex process, requiring the metastatically successful cancer cell to negotiate a formidable series of interconnected steps, which are described in this paper. For each step, we review the range of in vitro assays that may be used to study them. We also provide a range of detailed, step-by-step protocols that can be undertaken in most modestly-equipped laboratories, including methods for converting qualitative observations into quantitative data for analysis. Assays include: (1) a gelatin degradation assay to study the ability of endothelial cells to degrade extracellular matrix during tumour angiogenesis; (2) the morphological characterisation of cells undergoing epithelial-mesenchymal transition (EMT) as they acquire motility; (3) a 'scratch' or 'wound-healing' assay to study cancer cell migration; (4) a transwell assay to study cancer cell invasion through extracellular matrix; and (5) a static adhesion assay to examine cancer cell interactions with, and adhesion to, endothelial monolayers. This toolkit of protocols will enable researchers who are interested in metastasis to begin to focus on defined aspects of the process. It is only by further understanding this complex, fascinating and clinically relevant series of events that we may ultimately devise ways of better treating, or even preventing, cancer metastasis. The assays may also be of more broad interest to researchers interested in studying aspects of cellular behaviour in relation to other developmental and disease processes.

Differences and similarities between cancer and somatic stem cells: therapeutic implications

Over the last decades, the cancer survival rate has increased due to personalized therapies, the discovery of targeted therapeutics and novel biological agents, and the application of palliative treatments. Despite these advances, tumor resistance to chemotherapy and radiation and rapid progression to metastatic disease are still seen in many patients. Evidence has shown that cancer stem cells (CSCs), a sub-population of cells that share many common characteristics with somatic stem cells (SSCs), contribute to this therapeutic failure. The most critical properties of CSCs are their self-renewal ability and their capacity for differentiation into heterogeneous populations of cancer cells. Although CSCs only constitute a low percentage of the total tumor mass, these cells can regrow the tumor mass on their own. Initially identified in leukemia, CSCs have subsequently been found in cancers of the breast, the colon, the pancreas, and the brain. Common genetic and phenotypic features found in both SSCs and CSCs, including upregulated signaling pathways such as Notch, Wnt, Hedgehog, and TGF-β. These pathways play fundamental roles in the development as well as in the control of cell survival and cell fate and are relevant to therapeutic targeting of CSCs. The differences in the expression of membrane proteins and exosome-delivered microRNAs between SSCs and CSCs are also important to specifically target the stem cells of the cancer. Further research efforts should be directed toward elucidation of the fundamental differences between SSCs and CSCs to improve existing therapies and generate new clinically relevant cancer treatments.

HOX Genes Family and Cancer: A Novel Role for Homeobox B9 in the Resistance to Anti-Angiogenic Therapies

Simple Summary

The inhibition of angiogenesis, relying on the use of drugs targeting the VEGF signaling pathway, has become one of the main strategies for cancer treatment. However, the intrinsic and acquired resistance to this type of therapy limit its efficacy. Thus, the identification of novel therapeutic targets is urgently needed. The resistance to anti-angiogenic treatment often occurs through the activation of alternative VEGF independent signaling pathways and recruitment of bone marrow-derived pro-angiogenic cells in the tumor microenvironment. HOX genes are key regulators of embryonic development, also involved in angiogenesis and in cancer progression. HOXB9 upregulation occurs in many types of cancer and it has been identified as a critical transcription factor involved in tumour resistance to anti-angiogenic drugs. Indeed, HOXB9 modulates the expression of alternative pro-angiogenic secreted factors in the tumour microenvironment leading tumor escape from the anti-angiogenic treatments. Hence, HOXB9 could serves as a novel therapeutic target to overcome the resistance to anti-angiogenic therapies.

Abstract

Angiogenesis is one of the hallmarks of cancer, and the inhibition of pro-angiogenic factors and or their receptors has become a primary strategy for cancer therapy. However, despite promising results in preclinical studies, the majority of patients either do not respond to these treatments or, after an initial period of response, they develop resistance to anti-angiogenic agents. Thus, the identification of a novel therapeutic target is urgently needed. Multiple mechanisms of resistance to anti-angiogenic therapy have been identified, including the upregulation of alternative angiogenic pathways and the recruitment of pro-angiogenic myeloid cells in the tumor microenvironment. Homeobox containing (HOX) genes are master regulators of embryonic development playing a pivotal role during both embryonic vasculogenesis and pathological angiogenesis in adults. The importance of HOX genes during cancer progression has been reported in many studies. In this review we will give a brief description of the HOX genes and their involvement in angiogenesis and cancer, with particular emphasis on HOXB9 as a possible novel target for anti-angiogenic therapy. HOXB9 upregulation has been reported in many types of cancers and it has been identified as a critical transcription factor involved in resistance to anti-angiogenic drugs.

The enigmatic helicase DHX9 and its association with the hallmarks of cancer

Much interest has been expended lately in characterizing the association between DExH-Box helicase 9 (DHX9) dysregulation and malignant development, however, the enigmatic nature of DHX9 has caused conflict as to whether it regularly functions as an oncogene or tumor suppressor. The impact of DHX9 on malignancy appears to be cell-type specific, dependent upon the availability of binding partners and activation of inter-connected signaling pathways. Realization of DHX9's pivotal role in the development of several hallmarks of cancer has boosted the enzyme's potential as a cancer biomarker and therapeutic target, opening up novel avenues for exploring DHX9 in precision medicine applications. Our review discusses the ascribed functions of DHX9 in cancer, explores its enigmatic nature and potential as an antineoplastic target.

The mesenchymal property of mouse mammary anlagen repopulating cell population is associated with its stemness

During early embryogenesis, mammary glands are derived from surface ectoderm and their morphogenesis is controlled by mammary stem cells (MaSCs) and epithelial-mesenchymal transition (EMT). Mammary anlagen stage (E13.5-15.5) is an important stage for fetal mice to achieve EMT dependent mammary morphogenesis. And the characteristics of mammary anlagen repopulating cell population (MaRC) should be identified for understanding its stemness at earlier embryonic stage. Here we quantify and characterize MaSCs proportion at mammary anlagen stage. Compared with adult mouse mammary gland, our data revealed that E14.5 mammary anlagen exhibit higher stem cell activities. Then we purified mammary anlagen cell populations depending on the expression levels of CD24 and CD49f in mouse mammary anlagen, and identified an unique MaRC population (Lin-CD24medCD49f+) by real-time PCR, transplantation and mammosphere forming assays. In addition, by comparing with adult MaSC (Lin-CD24+CD29hi) and differentiated mammary anlagen cells, we find that E14.5 mouse MaRC population exhibit gene expression programs related to mesenchymal properties. To further identify the cell types of E14.5 mouse MaRC population, the expressions of K8, K14, K18, e-cadherin, n-cadherin and vimentin in mammary anlagen Lin-CD24medCD49f + cells were detected by immunofluorescence assay. These findings verified that the undifferentiated E14.5 mouse MaRC population is a heterogeneous population with mesenchymal property, which is associated with cell stemness and mammary duct morphogenesis.

Rosuvastatin inhibit spheroid formation and epithelial-mesenchymal transition (EMT) in prostate cancer PC-3 cell line

There is a growing body of evidence suggesting antitumor activity of statins. In metastasis and invasion of cancer the Epithelial-Mesenchymal Transition (EMT) of cancerous cells is an important process. Our goal was to understand the effect of Rosuvastatin on the EMT process in human prostate cancer cell line PC-3 cells in adherent 2 dimensional (2D) and spheroid 3 dimensional (3D) culture. PC-3 cells were cultured in adherence and/or spheroid culture system. The cells were treated with different concentrations of Rosuvastatin. After 96 h, the cell proliferation, viability, type and number of spheroids, the expression of E-Cadherin, Vimentin and Zeb-1 were analyzed. The results show that Rosuvastatin inhibit cell proliferation without significant cytotoxicity. The spheroid formation and spheroid sizes were inhibited by Rousavastatin in a dose dependent manner. In 2D culture, expression of the E-Cadherin was increased up to 2.0 fold in a dose dependent linear manner (R² = 0.89). Vimentin and Zeb-1 expressions were decreased up to 40 and 20% of untreated control cells expression level respectively, (R² = 0.99 and 0.92). In 3D system, the expression of E-Cadherin did not show a significant change, but Vimentin and Zeb-1 expressions were decreased up to 70 and 40% of untreated control cells expression level respectively in a dose dependent linear manner in comparison to 2D system (R² = 0.36 and 0.90). Our finding indicates that Rousavastatin inhibit cell proliferation and spheroid formation of PC-3 cells. This inhibition accompanies by inhibition of EMT markers. Therefor, this cholesterol lowering agent could probably have potential in the prevention and suppression of cancer in androgen dependent prostate cancer.

Simulation of multiple microenvironments shows a pivot role of RPTPs on the control of Epithelial-to-Mesenchymal Transition

Epithelial-to-Mesenchymal Transition (EMT) is a natural and reversible process involved in embryogenesis, wound healing and thought to participate in the process of metastasis. Multiple signals from the microenvironment have been reported to drive EMT. However, the tight control of this process on physiological scenarios and how it is disrupted during cancer progression is not fully understood. Here, we analysed a regulatory network of EMT accounting for 10 key microenvironment signals focusing on the impact of two cell contact signals on the reversibility of EMT and the stability of resulting phenotypes. The analysis showed that the microenvironment is not enough for stabilizing Hybrid and Amoeboid-like phenotypes, requiring intracellular de-regulations as reported during cancer progression. Our simulations demonstrated that RPTP activation by cell contacts have the potential to inhibit the process of EMT and trigger its reversibility under tissue growth and chronic inflammation scenarios. Simulations also showed that hypoxia inhibits the capacity of RPTPs to control EMT. Our analysis further provided a theoretical explanation for the observed correlation between hypoxia and metastasis under chronic inflammation, and predicted that de-regulations in FAT4 signalling may promote Hybrid stabilization. Taken together, we propose a natural control mechanism of EMT that supports the idea that EMT is tightly regulated by the microenvironment.

MicroRNA-1236-3p inhibits human osteosarcoma growth

Osteosarcoma (OS) is a common bone tumor with high mortality worldwide. The long-term survival rate of patients with metastatic or recurrent disease is <20%. The present study explored the biological role of microRNA (miRNA/miR)-1236-3p in OS. miRNA and mRNA expression levels were measured via reverse transcription-quantitative PCR. Fluorescence in situ hybridization was performed to determine miR-1236-3p expression levels in clinical specimens. Protein expression was measured via western blotting. Immunohistochemical analysis was used to detect Wnt target gene expression in tumor tissues. The interaction between the Wnt3a 3′untranslated region and miR-1236-3p was assessed via dual-luciferase reporter assays. Cell cycle, Transwell, Cell Counting Kit-8 and wound healing assays were conducted to evaluate the function of the miR-1236-3p/Wnt3a axis. Human OS (HOS) cells stably transfected with vector or miR-1236-3p sponge were injected subcutaneously into nude mice to assess the role of miR-1236-3p in vivo. miR-1236-3p expression was downregulated in OS tissues compared with chondroma tissues, and miR-1236-3p overexpression inhibited OS cell migration and proliferation compared with the negative control group. Furthermore, in vivo xenograft assays displayed enhanced tumour growth rates in the miR-1236-3p sponge group compared with the vector control group. In the present study, the results indicated that miR-1236-3p inhibited OS progression and Wnt3a was identified as a target of miR-1236-3p.

Wogonoside Attenuates Cutaneous Squamous Cell Carcinoma by Reducing Epithelial-Mesenchymal Transition/Invasion and Cancer Stem-Like Cell Property

Purpose

Cutaneous squamous cell carcinoma (cSCC) is the most common second basal cell carcinoma in our population. Wogonoside, the main in vivo metabolite of wogonin, possesses anti-inflammatory, anti-angiogenesis and anti-cancer activities. Nevertheless, the effectiveness of wogonoside therapy on cSCC has not been clarified.

Methods

In this study, we investigated the effects of wogonoside on cell proliferation, invasion, epithelial–mesenchymal transition (EMT) and cancer stem-like cell (CSC) properties of SCL-1 and SCC12 cell lines, and the effects on tumor formation in vivo. In vitro, cells were treated with 0, 25, 50 and 100 μM wogonoside for 48 h. In vivo, SCL-1 cells were subcutaneously injected into the right thigh of mice to form xenograft tumors. Animals were randomly divided into two groups (n=10): the control group and the 80 mg/kg wogonoside group.

Results

The results showed that wogonoside attenuated proliferation, invasion and EMT of SCL-1 and SCC12 cell lines, and enhanced the rate of apoptosis. Meanwhile, wogonoside efficiently abolished the CSC traits of cSCC; the expression of CSC markers (ALDH1, SOX-2, Oct4 and CD44) and the percentage of CD133⁺ cells were remarkably downregulated. In addition, we found that wogonoside repressed the activation of both PI3K/AKT and Wnt/β-catenin pathways. In vivo, wogonoside significantly inhibited tumor formation.

Conclusion

The results indicated that wogonoside could attenuate cSCC by reducing EMT, invasion and CSC properties. The efficacy of intervention may be related to inhibition of the PI3K/Akt and Wnt/β-catenin pathways. These novel findings could furnish new ideas on the potential therapeutic application of wogonoside in cSCC cancellation and cancer intervention.

Real-time fluorometric evaluation of hepatoblast proliferation in vivo and in vitro using the expression of CYP3A7 coding for human fetus-specific P450

The fields of drug discovery and regenerative medicine require large numbers of adult human primary hepatocytes. For this purpose, it is desirable to use hepatocyte-like cells (HLCs) differentiated from human pluripotent stem cells (PSCs). Premature hepatoblast-like cells (HB-LCs) differentiated from PSCs provide an intermediate source and steady supply of newly mature HLCs. To develop an efficient HB-LC induction method, we constructed a red fluorescent reporter, CYP3A7R, in which DsRed is placed under the transcriptional control of CYP3A7 coding for a human fetus-type P450 enzyme. Before using this reporter in human cells, we created transgenic mice using mouse embryonic stem cells (ESCs) carrying a CYP3A7R transgene and confirmed that CYP3A7R was specifically expressed in fetal and newborn livers and reactivated in the adult liver in response to hepatic regeneration. Moreover, we optimized the induction procedure of HB-LCs from transgenic mouse ESCs using semi-quantitative fluorometric evaluation. Activation of Wnt signaling together with chromatin modulation prior to Activin A treatment greatly improved the induction efficiency of HB-LCs. BMP2 and 1.7% dimethyl sulfoxide induced selective proliferation of HB-LCs, which matured to HLCs. Therefore, CYP3A7R will provide a fluorometric evaluation system for high content screening of chemicals that induce HB-LC differentiation, hepatocyte regeneration, and hepatotoxicity when it is introduced into human PSCs.

The Role of microRNAs in Epithelial Ovarian Cancer Metastasis

Epithelial ovarian cancer (EOC) is the deadliest gynecological cancer, and the major cause of death is mainly attributed to metastasis. MicroRNAs (miRNAs) are a group of small non-coding RNAs that exert important regulatory functions in many biological processes through their effects on regulating gene expression. In most cases, miRNAs interact with the 3′ UTRs of target mRNAs to induce their degradation and suppress their translation. Aberrant expression of miRNAs has been detected in EOC tumors and/or the biological fluids of EOC patients. Such dysregulation occurs as the result of alterations in DNA copy numbers, epigenetic regulation, and miRNA biogenesis. Many studies have demonstrated that miRNAs can promote or suppress events related to EOC metastasis, such as cell migration, invasion, epithelial-to-mesenchymal transition, and interaction with the tumor microenvironment. In this review, we provide a brief overview of miRNA biogenesis and highlight some key events and regulations related to EOC metastasis. We summarize current knowledge on how miRNAs are dysregulated, focusing on those that have been reported to regulate metastasis. Furthermore, we discuss the role of miRNAs in promoting and inhibiting EOC metastasis. Finally, we point out some limitations of current findings and suggest future research directions in the field.

Long non-coding RNA LINC01116 is overexpressed in lung adenocarcinoma and promotes tumor proliferation and metastasis

Long non-coding RNA LINC01116 is involved in the occurrence and progression of a variety of cancers. However, the specific role of LINC01116 in lung adenocarcinoma (LUAD) remains unclear. In this work, we found that LINC01116 was overexpressed in LUAD tissues and cell lines and that increased expression was significantly associated with worse prognoses in patients with LUAD. Univariate and multivariate Cox regression analyses indicated that LINC01116 was an independent risk factor for the prognosis of patients with LUAD. Downregulation of LINC01116 significantly inhibited cell proliferation and migration, promoted cell apoptosis, and prevented cell progression from G1 to S phase. In addition, downregulation of LINC01116 significantly inhibited the epithelial-mesenchymal transition, leading to an increased expression of the epithelial marker E-cadherin and decreased expression of the mesenchymal markers N-cadherin and vimentin. In summary, our results suggest that LINC01116 may act as an oncogene in LUAD and may be a valuable prognostic biomarker for patients with LUAD.

Sprouty2 regulates positioning of retinal progenitors through suppressing the Ras/Raf/MAPK pathway

Sproutys are negative regulators of the Ras/Raf/MAPK signaling pathway and involved in regulation of organogenesis, differentiation, cell migration and proliferation. Although the function of Sproutys have been extensively studied during embryonic development, their role and mode of action during eye formation in vertebrate embryonic development is still unknown. Here we show that Xenopus sprouty2 is expressed in the optic vesicle at late neurula stage and knockdown of Sprouty2 prevents retinal progenitors from populating the retina, which in turn gives rise to small eyes. In the absence of Sprouty2, progenitor cell population of the retina can be restored by blocking the MAPK signaling pathway through overexpression of DN-Ras or DN-Raf. In contrast, activation of the MAPK pathway through overexpression of a constitutively active form of c-Raf (ca-Raf) inhibits progenitor population of the retina, similar to the Sprouty2 loss-of-function phenotype. Moreover, we present evidence that the retinal defect observed in Sprouty2 morphants is attributed to the failure of proper movement of retinal progenitors into the optic vesicle, rather than an effect on progenitor cell survival. These results suggest that Sprouty2 is required for the positioning of retinal progenitors within the optic vesicle through suppressing Ras/Raf/MAPK signaling pathway.

PRP4 Kinase Domain Loss Nullifies Drug Resistance and Epithelial-Mesenchymal Transition in Human Colorectal Carcinoma Cells

We have investigated the involvement of the pre-mRNA processing factor 4B (PRP4) kinase domain in mediating drug resistance. HCT116 cells were treated with curcumin, and apoptosis was assessed based on flow cytometry and the generation of reactive oxygen species (ROS). Cells were then transfected with PRP4 or pre-mRNA-processing-splicing factor 8 (PRP8), and drug resistance was analyzed both in vitro and in vivo. Furthermore, we deleted the kinase domain in PRP4 using GatewayTM technology. Curcumin induced cell death through the production of ROS and decreased the activation of survival signals, but PRP4 overexpression reversed the curcumin-induced oxidative stress and apoptosis. PRP8 failed to reverse the curcumin-induced apoptosis in the HCT116 colon cancer cell line. In xenograft mouse model experiments, curcumin effectively reduced tumour size whereas PRP4 conferred resistance to curcumin, which was evident from increasing tumour size, while PRP8 failed to regulate the curcumin action. PRP4 overexpression altered the morphology, rearranged the actin cytoskeleton, triggered epithelial-mesenchymal transition (EMT), and decreased the invasiveness of HCT116 cells. The loss of E-cadherin, a hallmark of EMT, was observed in HCT116 cells overexpressing PRP4. Moreover, we observed that the EMT-inducing potential of PRP4 was aborted after the deletion of its kinase domain. Collectively, our investigations suggest that the PRP4 kinase domain is responsible for promoting drug resistance to curcumin by inducing EMT. Further evaluation of PRP4-induced inhibition of cell death and PRP4 kinase domain interactions with various other proteins might lead to the development of novel approaches for overcoming drug resistance in patients with colon cancer.

Histamine H4 receptor agonists induce epithelial-mesenchymal transition events and enhance mammosphere formation via Src and TGF-β signaling in breast cancer cells

Epithelial-mesenchymal transition (EMT) contributes to cell invasion and metastasis during the progression of epithelial cancers. Though preclinical evidence suggests a role for histamine H4 receptor (H4R) in breast cancer growth, its function in the EMT is less known. In this study we proposed to investigate the effects of H4R ligands on EMT and mammosphere formation as a surrogate assay for cancer stem cells in breast cancer cells with different invasive phenotype. We also investigated the participation of Src and TGF-β signaling in these events. Breast cancer cells were treated with the H4R agonists Clobenpropit, VUF8430 and JNJ28610244 and the H4R antagonist JNJ7777120. Immunodetection studies showed cytoplasmic E-cadherin, cytoplasmic and nuclear beta-catenin, nuclear Slug and an increase in vimentin and α-smooth muscle actin expression. There was also an enhancement in cell migration and invasion assessed by transwell units. All these effects were prevented by JNJ7777120. Moreover, H4R agonists induced an increase in phospho-Src levels detected by Western blot. Results revealed the involvement of phospho-Src in EMT events. Upon treatment with H4R agonists there was an increase in phospho-ERK1/2 and TGF-β1 levels by Western blot, in Smad2/3 positive nuclei by indirect immunofluorescence, and in tumor spheres formation by the mammosphere assay. Notably, the selective TGF-β1 kinase/activin receptor-like kinase inhibitor A83-01 blocked these effects. Moreover, cells derived from mammospheres exhibited higher Slug expression and enhanced migratory behavior. Collectively, findings support the interaction between H4R and TGF-β receptor signaling in the enhancement of EMT features and mammosphere formation and point out intracellular TGF-β1 as a potential mediator of these events.

Dietary Polyphenols in Cancer Chemoprevention: Implications in Pancreatic Cancer

Naturally occurring dietary agents present in a wide variety of plant products, are rich sources of phytochemicals possessing medicinal properties, and thus, have been used in folk medicine for ages to treat various ailments. The beneficial effects of such dietary components are frequently attributed to their anti-inflammatory and antioxidant properties, particularly in regards to their antineoplastic activities. As many tumor types exhibit greater oxidative stress levels that are implicated in favoring autonomous cell growth activation, most chemotherapeutic agents can also enhance tumoral oxidative stress levels in part via generating reactive oxygen species (ROS). While ROS-mediated imbalance of the cellular redox potential can provide novel drug targets, as a consequence, this ROS-mediated excessive damage to cellular functions, including oncogenic mutagenesis, has also been implicated in inducing chemoresistance. This remains one of the major challenges in the treatment and management of human malignancies. Antioxidant-enriched natural compounds offer one of the promising approaches in mitigating some of the underlying mechanisms involved in tumorigenesis and metastasis, and therefore, have been extensively explored in cancer chemoprevention. Among various groups of dietary phytochemicals, polyphenols have been extensively explored for their underlying chemopreventive mechanisms in other cancer models. Thus, the current review highlights the significance and mechanisms of some of the highly studied polyphenolic compounds, with greater emphasis on pancreatic cancer chemoprevention.

Isocorydine decrease gemcitabine-resistance by inhibiting epithelial-mesenchymal transition via STAT3 in pancreatic cancer cells

Gemcitabine is widely used as an anticancer chemotherapy drug for a variety of solid tumors, and it has become the standard treatment option for locally advanced and metastatic pancreatic cancer. However, pancreatic cancer cells develop resistance to gemcitabine after a few weeks of treatment, resulting in poor therapeutic effects. Isocorydine (ICD) is a typical natural aporphine alkaloid, and ICD and its derivatives inhibit the proliferation of many types of cancer cells in vitro. In this study, ICD was found to synergistically inhibit cell viability with gemcitabine in pancreatic cancer cells. A microarray analysis showed that ICD can inhibit the upregulation of STAT3 and EMT in pancreatic cancer cells induced by gemcitabine. STAT3 is closely related to tumor EMT, migration and invasion. After knocking down the expression of STAT3 in pancreatic cancer cells, the combination index (CI) of ICD and gemcitabine decreased. ICD can reverse the increase in the expression of EMT-related transcription factors and proteins caused by gemcitabine, thereby inhibiting the enhanced cell migration and invasion ability caused by gemcitabine. Finally, the synergistic treatment effect of the combination treatment of ICD and gemcitabine in pancreatic cancer cells was confirmed in established xenograft models.

α-Linolenic acid inhibits the migration of human triple-negative breast cancer cells by attenuating Twist1 expression and suppressing Twist1-mediated epithelial-mesenchymal transition

α-Linolenic acid (ALA), an essential fatty acid, has anticancer activity in breast cancer, but the mechanism of its effects in triple-negative breast cancer (TNBC) remains unclear. We investigated the effect of ALA on Twist1, which is required to initiate epithelial-mesenchymal transition (EMT) and promotes tumor metastasis, and Twist1-mediated migration in MDA-MB231, MDA-MB468 and Hs578T cells. Twist1 protein was constitutively expressed in these TNBC cells, particularly MDA-MB-231 cells. Treatment with 100 μM ALA and Twist1 siRNA markedly decreased the Twist1 protein level and cell migration. Moreover, ALA transiently attenuated the nuclear accumulation of STAT3α as well as Twist1 mRNA expression. Treatment with ALA significantly attenuated the phosphorylation of JNK, ERK and Akt and decreased the phosphorylation of Twist1 at serine 68 in MDA-MB-231 cells. ALA accelerated Twist1 degradation in the presence of cycloheximide, whereas the ubiquitination and degradation of Twist1 by ALA was suppressed by MG-132. Pretreatment with ALA mimicked Twist1 siRNA, increased the protein expression of epithelial markers such as E-cadherin, and decreased the protein expression of mesenchymal markers including Twist1, Snail2, N-cadherin, vimentin, and fibronectin. Our findings suggest that ALA can be used not only to abolish EMT but also to suppress Twist1-mediated migration in TNBC cells.

Slug and E-Cadherin: Stealth Accomplices?

During physiological epithelial-mesenchymal transition (EMT), which is important for embryogenesis and wound healing, epithelial cells activate a program to remodel their structure and achieve a mesenchymal fate. In cancer cells, EMT confers increased invasiveness and tumor-initiating capacity, which contribute to metastasis and resistance to therapeutics. However, cellular plasticity that navigates between epithelial and mesenchymal states and maintenance of a hybrid or partial E/M phenotype appears to be even more important for cancer progression. Besides other core EMT transcription factors, the well-characterized Snail-family proteins Snail (SNAI1) and Slug (SNAI2) play important roles in both physiological and pathological EMT. Often mentioned in unison, they do, however, differ in their functions in many scenarios. Indeed, Slug expression does not always correlate with complete EMT or loss of E-cadherin (CDH1). For example, Slug plays important roles in mammary epithelial cell progenitor cell lineage commitment and differentiation, DNA damage responses, hematopoietic stem cell self-renewal, and in pathologies such as pulmonary fibrosis and atherosclerosis. In this Perspective, we highlight Slug functions in mammary epithelial cells and breast cancer as a “non-EMT factor” in basal epithelial cells and stem cells with focus reports that demonstrate co-expression of Slug and E-cadherin. We speculate that Slug and E-cadherin may cooperate in normal mammary gland and breast cancer/stem cells and advocate for functional assessment of such Slug⁺/E-cadherin^low/+ (SNAI2⁺/CDH1^low/+) “basal-like epithelial” cells. Thus, Slug may be regarded as less of an EMT factor than driver of the basal epithelial cell phenotype.

C-phycocyanin inhibits epithelial-to-mesenchymal transition in Caski cells

Background

In cervical cancer, most patients die of metastasis. The epithelial-to-mesenchymal transition (EMT) is a pivotal and intricate process that increases the metastatic potential of cervical cancer. C-phycocyanin (C-PC) is a natural marine product isolated and purified from Spirulina platensis, has been investigated that has anti-cancer function. The aim of this study was to explore the inhibitory effect of C-phycocyanin on the migration and invasion of cervical cancer cells induced by transforming growth factor-β1 (TGF-β1), so as to provide a new idea for the treatment and prognosis of cervical cancer.

Methods

A wound-healing assay, an invasion assay, immunofluorescence assay, western blot, flow cytometry and real-time reverse transcriptione polymerase chain reaction were explored in cervical cancer Caski cell lines. TGF-β/smad signaling pathway was evaluated of in Caski cell lines.

Results

Our study indicated that TGF-β1 induced EMT in cervical cancer cells. C-phycocyanin inhibited EMT in Caski cells by down-regulating N-cadherin and up-regulating E-cadherin protein expression. Furthermore, C-phycocyanin could inhibit the expression and proteins Twist, Snail and Zeb1 transcription factors related to EMT. In addition, C-phycocyanin could inhibit the migration and invasion of Caski cells induced by TGF-β1. Besides, C-phycocyanin inhibited EMT through TGF-β/smads signaling pathway. We also found C-phycocyanin induced cell cycle G0/G1 arrest by decreasing protein expression levels of Cyclin D1 and p27.

Conclusions

C-phycocyanin reversed TGF-β1-induced epithelial-to-mesenchymal transition in cervical cancer cells and down-regulated the TGF-β/samd signaling pathway induced G0/G1 arrest of tumor cell cycle.

Shikonin blocks human lung adenocarcinoma cell migration and invasion in the inflammatory microenvironment via the IL‑6/STAT3 signaling pathway

Increasing evidence indicates that the inflammatory tumor microenvironment can lead to cancer cell metastasis. Shikonin, which is extracted from the Chinese herb Zicao (the dried root of Lithospermum erythrorhizon), possesses various pharmacological effects, but its effect on tumor metastasis in the inflammatory microenvironment remains unknown. In the present study, we aimed to investigate the potential effect of shikonin on tumor metastasis in an inflammatory microenvironment as well as the underlying molecular mechanisms. It was found that, in the inflammatory microenvironment simulated by THP-1 cell conditioned medium (THP-1-CM) in vitro, shikonin significantly inhibited the epithelial-mesenchymal transition (EMT), migration and invasion of human lung adenocarcinoma cell lines A549 and H1299. In addition, we found that interleukin-6 (IL-6), which is expressed in THP-1-CM, promoted the EMT of lung adenocarcinoma cells, and shikonin markedly inhibited IL-6-induced EMT and cell motility. Moreover, shikonin inhibited IL-6-induced phosphorylation of signal transducer and activator of transcription 3 (STAT3), prevented phosphorylated STAT3 (p-STAT3) translocation into the nucleus, and suppressed p-STAT3 transactivation activity. Additionally, it was found that shikonin inhibited lung metastasis, EMT and expression of p-STAT3 of A549 cells in vivo. Furthermore, IL-6 levels in human lung adenocarcinoma tissues were significantly associated with tumor-node-metastasis stage and lymph node metastasis, and its expression was correlated with tumor-associated macrophage (TAM) infiltration. Together, these results suggest that shikonin suppresses the migration and invasion of human lung adenocarcinoma cells in an inflammatory microenvironment involving the IL-6/STAT3 signaling pathway.

Large intestine embryogenesis: Molecular pathways and related disorders (Review)

The large intestine, part of the gastrointestinal tract (GI), is composed of all three germ layers, namely the endoderm, the mesoderm and the ectoderm, forming the epithelium, the smooth muscle layers and the enteric nervous system, respectively. Since gastrulation, these layers develop simultaneously during embryogenesis, signaling to each other continuously until adult age. Two invaginations, the anterior intestinal portal (AIP) and the caudal/posterior intestinal portal (CIP), elongate and fuse, creating the primitive gut tube, which is then patterned along the antero‑posterior (AP) axis and the radial (RAD) axis in the context of left‑right (LR) asymmetry. These events lead to the formation of three distinct regions, the foregut, midgut and hindgut. All the above‑mentioned phenomena are under strict control from various molecular pathways, which are critical for the normal intestinal development and function. Specifically, the intestinal epithelium constitutes a constantly developing tissue, deriving from the progenitor stem cells at the bottom of the intestinal crypt. Epithelial differentiation strongly depends on the crosstalk with the adjacent mesoderm. Major molecular pathways that are implicated in the embryogenesis of the large intestine include the canonical and non‑canonical wingless‑related integration site (Wnt), bone morphogenetic protein (BMP), Notch and hedgehog systems. The aberrant regulation of these pathways inevitably leads to several intestinal malformation syndromes, such as atresia, stenosis, or agangliosis. Novel theories, involving the regulation and homeostasis of intestinal stem cells, suggest an embryological basis for the pathogenesis of colorectal cancer (CRC). Thus, the present review article summarizes the diverse roles of these molecular factors in intestinal embryogenesis and related disorders.