Epithelial-mesenchymal transition as a fundamental mechanism underlying the cancer phenotype

Epithelial-mesenchymal transition in an EcPV2-positive vulvar squamous cell carcinoma of a mare

BACKGROUND

Vulvar squamous cell carcinoma (VSCC) has been recently associated with Equus caballus papillomavirus type 2 (EcPV2) infection. Still, few reports concerning this disease are present in the literature.

OBJECTIVE

To describe a case of naturally occurring EcPV2-induced VSCC, by investigating tumour ability in undergoing the epithelial-to-mesenchymal transition (EMT).

STUDY DESIGN

Case report.

METHODS

A 13-year-old Haflinger mare was referred for a rapidly growing vulvar mass. After surgical excision, the mass was submitted to histopathology and molecular analysis. Histopathological diagnosis was consistent with a VSCC. Real-time qPCR, real-time reverse transcriptase (RT)-qPCR and RNAscope were carried out to detect EcPV2 infection and to evaluate E6/E7 oncogenes expression. To highlight the EMT, immunohistochemistry (IHC) was performed. Expression of EMT-related and innate immunity-related genes was investigated through RT-qPCR.

RESULTS

Real-time qPCR, RT-qPCR and RNAscope confirmed EcPV2 DNA presence and expression of EcPV2 oncoproteins (E6 and E7) within the neoplastic vulvar lesion. IHC highlighted a cadherin switch together with the expression of the EMT-related transcription factor HIF1α. With RT-qPCR, significantly increased gene expression of EBI3 (45.0 ± 1.62, p < 0.01), CDH2 (2445.3 ± 0.39, p < 0.001), CXCL8 (288.7 ± 0.40, p < 0.001) and decreased gene expression of CDH1 (0.3 ± 0.57, p < 0.05), IL12A (0.04 ± 1.06, p < 0.01) and IL17 (0.2 ± 0.64, p < 0.05) were detected.

MAIN LIMITATIONS

Lack of ability to generalise and danger of over-interpretation.

CONCLUSION

The results obtained were suggestive of an EMT event occurring within the neoplastic lesion.

Vulvo-vaginal epithelial tumors in mares: A preliminary investigation on epithelial-mesenchymal transition and tumor-immune microenvironment

Vulvo-vaginal epithelial tumors are uncommon in mares, and data on the epithelial-to-mesenchymal transition (EMT) and the tumor-immune microenvironment (TIME) are still lacking. This is a study investigating the equus caballus papillomavirus type 2 (EcPV2) infection state as well as the EMT process and the tumor microenvironment in vulvo-vaginal preneoplastic/ benign (8/22) or malignant (14/22) epithelial lesions in mares. To do this, histopathological, immunohistochemical, transcriptomic, in situ hybridization, and correlation analyses were carried out. Immunohistochemistry quantification showed that cytoplasmic E-cadherin and β-catenin expression as well as nuclear β-catenin expression were features of malignant lesions, while benign/preneoplastic lesions were mainly characterized by membranous E-cadherin and β-catenin expression. Despite this, there were no differences between benign and malignant equine vulvo-vaginal lesions in the expression of downstream genes involved in the canonical and noncanonical wnt/β-catenin pathways. In addition, malignant lesions were characterized by a lower number of cells with cytoplasmic cytokeratin expression as well as a slightly higher cytoplasmic vimentin immunolabeling. The TIME of malignant lesions was characterized by more numerous CD204+ M2-polarized macrophages. Altogether, our results support the hypothesis that some actors in TIME such as CD204+ M2-polarized macrophages may favor the EMT process in equine vulvo-vaginal malignant lesions providing new insights for future investigations in the field of equine EcPV2-induced genital neoplastic lesions.

5-Methoxytryptophan enhances the sensitivity of sorafenib on the inhibition of proliferation and metastasis for lung cancer cells

BACKGROUND

Lung cancer is a leading cause of cancer-related mortality worldwide, and effective therapies are limited. Lung cancer is a leading cause of cancer-related mortality worldwide with limited effective therapy. Sorafenib is a multi-tyrosine kinase inhibitor frequently used to treat numerous types of malignant tumors. However, it has been demonstrated that sorafenib showed moderate antitumor activity and is associated with several side effects in lung cancer, which restricted its clinical application. This study aimed to examine the antitumor effect of the combination treatment of sorafenib and 5-methoxytryptophan (5-MTP) on cell growth and metastasis of Lewis lung carcinoma (LLC) cells.

METHOD

The anticancer effect of the combination treatment of sorafenib and 5-MTP was determined through cytotoxicity assay and colony forming assays. The mechanism was elucidated using flow cytometry and western blotting. Wound healing and Transwell assays were conducted to evaluate the impact of the combination treatment on migration and invasion abilities. An in vivo model was employed to analyze the effect of the combination treatment on the tumorigenic ability of LLC cells.

RESULT

Our results demonstrated that the sorafenib and 5-MTP combination synergistically reduced viability and proliferation compared to sorafenib or 5-MTP treatment alone. Reduction of cyclin D1 expression was observed in the sorafenib alone or combination treatments, leading to cell cycle arrest. Furthermore, the sorafenib-5-MTP combination significantly increased the inhibitory effect on migration and invasion of LLC cells compared to the single treatments. The combination also significantly downregulated vimentin and MMP9 levels, contributing to the inhibition of metastasis. The reduction of phosphorylated Akt and STAT3 expression may further contribute to the inhibitory effect on proliferation and metastasis. In vivo, the sorafenib-5-MTP combination further reduced tumor growth and metastasis compared to the treatment of sorafenib alone.

CONCLUSIONS

In conclusion, our data indicate that 5-MTP sensitizes the antitumor activity of sorafenib in LLC cells in vitro and in vivo, suggesting that sorafenib-5-MTP has the potential to serve as a therapeutic option for patients with lung cancer.

The mechanistic role of NAT10 in cancer: Unraveling the enigmatic web of oncogenic signaling

N-acetyltransferase 10 (NAT10), a versatile enzyme, has gained considerable attention as a significant player in the complex realm of cancer biology. Its enigmatic role in tumorigenesis extends across a wide array of cellular processes, impacting cell growth, differentiation, survival, and genomic stability. Within the intricate network of oncogenic signaling, NAT10 emerges as a crucial agent in multiple cancer types, such as breast, lung, colorectal, and leukemia. This compelling research addresses the intricate complexity of the mechanistic role of NAT10 in cancer development. By elucidating its active participation in essential physiological processes, we investigate the regulatory role of NAT10 in cell cycle checkpoints, coordination of chromatin remodeling, and detailed modulation of the delicate balance between apoptosis and cell survival. Perturbations in NAT10 expression and function have been linked to oncogenesis, metastasis, and drug resistance in a variety of cancer types. Furthermore, the bewildering interactions between NAT10 and key oncogenic factors, such as p53 and c-Myc, are deciphered, providing profound insights into the molecular underpinnings of cancer pathogenesis. Equally intriguing, the paradoxical role of NAT10 as a potential tumor suppressor or oncogene is influenced by context-dependent factors and the cellular microenvironment. This study explores the fascinating interplay of genetic changes, epigenetic changes, and post-translational modifications that shape the dual character of NAT10, revealing the delicate balance between cancer initiation and suppression. Taken together, this overview delves deeply into the enigmatic role of NAT10 in cancer, elucidating its multifaceted roles and its complex interplay with oncogenic networks.

Cofilin Acts as a Booster for Progression of Malignant Tumors Represented by Glioma

Cofilin, as a depolymerization factor of actin filaments, has been widely studied. Evidences show that cofilin has a role in actin structural reorganization and dynamic regulation. In recent years, several studies have demonstrated a regulatory role for cofilin in the migration and invasion mediated by cell dynamics and epithelial to mesenchymal transition (EMT)/EMT-like process, apoptosis, radiotherapy resistance, immune escape, and transcriptional dysregulation of malignant tumor cells, particularly glioma cells. On this basis, it is practical to evaluate cofilin as a biomarker for predicting tumor metastasis and prognosis. Targeting cofilin regulating kinases, Lin11, Isl-1 and Mec-3 kinases (LIM kinases/LIMKs) and their major upstream molecules inhibits tumor cell migration and invasion and targeting cofilin-mediated mitochondrial pathway induces apoptosis of tumor cells represent effective options for the development of novel anti-malignant tumor drug, especially anti-glioma drugs. This review explores the structure, general biological function, and regulation of cofilin, with an emphasis on the critical functions and prospects for clinical therapeutic applications of cofilin in malignant tumors represented by glioma.

Mixed computational-experimental study to reveal the anti-metastasis and anti-angiogenesis effects of Astragalin in human breast cancer

BACKGROUND

Breast cancer is the most aggressive malignant tumor with high morbidity and mortality. Astragalin, a flavonoid widely found in a variety of edible and medicinal plants, is recorded to possess multiple biological and pharmacological activities. However, its effect of anti-breast cancer has been unknown.

METHODS

Computational pharmacology was employed to explore the potential mechanism of anti-metastasis and anti-angiogenesis effects of Astragalin on breast cancer. The targets of Astragalin were obtained from TCMSP, Swiss Target Prediction, SEA, BATMAN-TCM, ChemMapper and STITCH databases, and targets of breast cancer were got from OMIM, GeneCards, and DisGeNET databases. Protein-protein interaction network (PPI), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to elucidate the interactions of these two groups of targets. Moreover, the anti-metastasis and anti-angiogenesis effects of Astragalin were validated by in vitro and in vivo experiments using wound healing assay, transwell migration and invasion assay, gelatin zymography assay, tube formation assay, and chick embryo chorioallantoic membrane model.

RESULTS

Computational pharmacology analysis indicated that the effects of Astragalin against breast cancer were mainly related to the regulation of the cell movement, migration, and angiogenesis, and taking AKT, ZEB1, VEGF, and MMP9 as the promising targets. Further experimental pharmacology indicated that Astragalin exerted anti-metastasis and anti-angiogenesis activities on breast cancer, and verified AKT, ZEB1, VEGF, and MMP9 as the key targets.

CONCLUSION

Astragalin suppresses the metastasis and angiogenesis of breast cancer, and AKT, ZEB1, VEGF, and MMP9 are the promising targets for Astragalin against breast cancer. Thus, Astragalin is a potential therapeutic agent for breast cancer.

Circ_001042 Inhibits TGF-β1/P38 MAPK Signaling Axis-Mediated Epithelial-Mesenchymal Transition and Metastasis in Lung Adenocarcinoma

Objective

To explore the role and molecular mechanism of circ_001042 in lung adenocarcinoma (LUAD).

Methods

The expression level of circ_001042 and linear RNA MRPS35 in cells and clinical tissues was detected by real-time PCR (qRT-PCR). The expression of circ_001042 and transforming growth factor β1 (TGF-β1) in LUAD cells was elevated by the respective transfection of overexpression vectors OE-circ_001042 and TGF-β1; MTT and transwell assays were applied to test the proliferation, migration, and invasion abilities of cells, respectively. The E-cadherin expression level in the cells was assessed by immunofluorescence staining, and western blot was utilized to determine the expression level of epithelial-mesenchymal transition (EMT) and TGF-β1/P38 MAPK signaling axis-related proteins in the cells.

Results

Circ_001042 was significantly downregulated in LUAD tissues and cells, and high circ_001042 expression could inhibit the proliferation, invasion, and migration of LUAD cells. In addition, circ_001042 also inhibited the EMT process (the E-cadherin level was upregulated; and the levels of N-cadherin, vimentin, and Snail were downregulated) and TGF-β1/P38 MAPK signaling axis activity in LUAD cells. Moreover, circ_001042 could suppress the promotion of TGF-β1 on the proliferation, invasion, migration, and EMT process of LUAD cells and the activation of TGF-β1/P38 MAPK signaling axis.

Conclusion

By inhibiting TGF-β1, circ_001042 not only suppresses the proliferation, migration, invasion, and EMT of LUAD but also inhibits the activation of TGF-β1/P38 MAPK signaling axis. Therefore, circ_001042 can act as a potential target for early diagnosis and targeted therapy of LUAD.

circRPPH1_025 Overexpression Promotes Migration and Invasion of Glioblastoma Multiforme

Objective

To study the effect of circ_0000512 (circRPPH1_025) on the tumorigensis and development of glioblastoma and its molecular mechanism.

Methods

The expression levels of circ_0000512 in normal astrocytes (NHA) and human glioblastoma cell lines (U87, U251, and A172) and the expression levels of circ_0000512 and linear RNA RPPH1 in U87 cells after RNase R treatment were detected by qRT-PCR. The effects of circ_0000512 knockdown or overexpression on the proliferation, migration, invasion, and epithelial-mesenchymal transition of U87 cells were detected by CCK-8 assay, cell colony formation assay, transwell invasion assay, wound healing assay, and western blot.

Results

The expression of circ_0000512 was upregulated in glioblastoma cells, and the overexpression of circ_0000512 was beneficial to the proliferation, migration, invasion, and epithelial-mesenchymal transition of U87 cells, while knockdown of circ_0000512 showed the opposite results.

Conclusion

circ_0000512 can be used as a potential target for early diagnosis and targeted therapy of glioblastoma multiforme.

Tumor budding of cervical squamous cell carcinoma: epithelial-mesenchymal transition-like cancer stem cells?

Recent evidence indicates that cancer stem cells (CSCs) are the origin of cancers. Scientists have identified CSCs in various tumors and have suggested the existence of a variety of states of CSCs. The existence of epithelial-mesenchymal transition (EMT)-like CSCs has been confirmed in vitro, but they have not been identified in vivo. Tumor budding was defined as single cell or clusters of ≤ 5 cells at the invasive front of cancers. Such tumor budding is hypothesized to be closely related to EMT and linked to CSCs, especially to those migrating at the invasive front. Therefore, tumor budding has been proposed to represent EMT-like stem cells. However, this hypothesis has not yet been proven. Thus, we studied the expression of EMT markers, certain CSC markers of tumor budding, and the tumor center of cervical squamous cell carcinoma (CxSCC). We performed tissue chip analyses of 95 primary CxSCCs from patients. Expression of EMT and CSC markers (E-cadherin, β-catenin, vimentin, Ki67, CD44, SOX2 , and ALDH1A1) in a set of tumor samples on tissue chips (87 cases of tumor budding/the main tumor body) were evaluated by immunohistochemistry. We found that the cell-membranous expression of β-catenin was stronger in the main tumor body than in tumor buds. Compared with the main tumor body, tumor buds had reduced proliferative activity as measured by Ki67. Moreover, vimentin expression was high and E-cadherin expression was low in tumor buds. Expression of EMT-related markers suggested that tumor buds were correlated with EMT. We noted that CxSCC tumor buds had a CD44negative/low/SOX2high/ALDH1A1high staining pattern, indicating that tumor buds of CxSCC present CSC-like immunophenotypic features. Taken together, our data indicate that tumor buds in CxSCC may represent EMT-like CSCs in vivo.

Curcuminoids as Modulators of EMT in Invasive Cancers: A Review of Molecular Targets With the Contribution of Malignant Mesothelioma Studies

Curcuminoids, which include natural acyclic diarylheptanoids and the synthetic analogs of curcumin, have considerable potential for fighting against all the characteristics of invasive cancers. The epithelial-to-mesenchymal transition (EMT) is a fundamental process for embryonic morphogenesis, however, the last decade has confirmed it orchestrates many features of cancer invasiveness, such as tumor cell stemness, metabolic rewiring, and drug resistance. A wealth of studies has revealed EMT in cancer is in fact driven by an increasing number of parameters, and thus understanding its complexity has now become a cornerstone for defining future therapeutic strategies dealing with cancer progression and metastasis. A specificity of curcuminoids is their ability to target multiple molecular targets, modulate several signaling pathways, modify tumor microenvironments and enhance the host’s immune response. Although the effects of curcumin on these various parameters have been the subject of many reviews, the role of curcuminoids against EMT in the context of cancer have never been reviewed so far. This review first provides an updated overview of all EMT drivers, including signaling pathways, transcription factors, non-coding RNAs (ncRNAs) and tumor microenvironment components, with a special focus on the most recent findings. Secondly, for each of these drivers the effects of curcumin/curcuminoids on specific molecular targets are analyzed. Finally, we address some common findings observed between data reported in the literature and the results of investigations we conducted on experimental malignant mesothelioma, a model of invasive cancer representing a useful tool for studies on EMT and cancer.

FSCN1 Promotes Glycolysis and Epithelial-Mesenchymal Transition in Prostate Cancer through a YAP/TAZ Signaling Pathway

Objective

The aim of the study is to investigate the role and possible mechanism of fascin-1 (FSCN1) in the invasion, migration, glycolysis, and epithelial-mesenchymal transition (EMT) of prostate cancer.

Methods

Real-time quantitative polymerase chain reaction (qRT-PCR) was utilized to determine the mRNA expression level of FSCN1 in prostate cancer tissues and prostate cancer cells PC-3 and DU145. The transwell and the scratch test were applied to detect the invasion and migration abilities of cells, respectively. A metabolic assay was used for measuring the glucose consumption, lactate production, and the extracellular acidification rate (ECAR) in cells; western blot was used for checking FSCN1, EMT, and yes-associated protein/transcriptional co-activators with the PDZ-binding motif (YAP/TAZ) signaling pathway-related protein expression level in cells or tissues.

Results

FSCN1 was significantly highly expressed in prostate cancer tissues and cells. On the one hand, interference with the expression of FSCN1 could inhibit the invasion, migration, EMT, and glycolysis of prostate cancer cells. On the other hand, overexpression of FSCN1 promoted the invasion, migration, EMT, and glycolysis of prostate cancer cells. Besides, further mechanistic studies revealed that FSCN1 could activate the YAP/TAZ signaling pathway in prostate cancer cells.

Conclusion

FSCN1 promotes invasion, migration, EMT, and glycolysis in prostate cancer cells by activating the YAP/TAZ signaling pathway. FSCN1 may be used as a biomarker for the diagnosis or treatment in prostate cancer.

Comparative Pathobiology of Canine and Human Prostate Cancer: State of the Art and Future Directions

First described in 1817, prostate cancer is considered a complex neoplastic entity, and one of the main causes of death in men in the western world. In dogs, prostatic carcinoma (PC) exhibits undifferentiated morphology with different phenotypes, is hormonally independent of aggressive character, and has high rates of metastasis to different organs. Although in humans, the risk factors for tumor development are known, in dogs, this scenario is still unclear, especially regarding castration. Therefore, with the advent of molecular biology, studies were and are carried out with the aim of identifying the main molecular mechanisms and signaling pathways involved in the carcinogenesis and progression of canine PC, aiming to identify potential biomarkers for diagnosis, prognosis, and targeted treatment. However, there are extensive gaps to be filled, especially when considering the dog as experimental model for the study of this neoplasm in humans. Thus, due to the complexity of the subject, the objective of this review is to present the main pathobiological aspects of canine PC from a comparative point of view to the same neoplasm in the human species, addressing the historical context and current understanding in the scientific field.

The Protein L-Isoaspartyl (D-Aspartyl) Methyltransferase Regulates Glial-to-Mesenchymal Transition and Migration Induced by TGF-β1 in Human U-87 MG Glioma Cells

The enzyme PIMT methylates abnormal aspartyl residues in proteins. U-87 MG cells are commonly used to study the most frequent brain tumor, glioblastoma. Previously, we reported that PIMT isoform I possessed oncogenic features when overexpressed in U-87 MG and U-251 MG glioma cells. Higher levels of wild-type PIMT stimulated migration and invasion in both glioma cell lines. Conversely, PIMT silencing reduced these migratory abilities of both cell lines. These results indicate that PIMT could play a critical role in glioblastoma growth. Here, we investigated for the first time, molecular mechanisms involving PIMT in the regulation of epithelial to mesenchymal transition (EMT) upon TGF-β1 treatments. Gene array analyses indicated that EMT genes but not PIMT gene were regulated in U-87 MG cells treated with TGF-β1. Importantly, PIMT silencing by siRNA inhibited in vitro migration in U-87 MG cells induced by TGF-β1. In contrast, overexpressed wild-type PIMT and TGF-β1 had additive effects on cell migration. When PIMT was inhibited by siRNA, this prevented Slug induction by TGF-β1, while Snail stimulation by TGF-β1 was increased. Indeed, overexpression of wild-type PIMT led to the opposite effects on Slug and Snail expression dependent on TGF-β1. These data highlighted the importance of PIMT in the EMT response dependent on TGF-β1 in U-87 MG glioma cells by an antagonist regulation in the expression of transcription factors Slug and Snail, which are critical players in EMT.

The Leaf Extract of Mitrephora chulabhorniana Suppresses Migration and Invasion and Induces Human Cervical Cancer Cell Apoptosis through Caspase-Dependent Pathway

Cervical cancer is rated to be the leading cause of cancer-related death in women worldwide. Since screening test and conventional treatments are less accessible for people in developing countries, an alternative use of medicinal plants exhibiting strong anticancer activities may be an affordable means to treat cervical cancer. Mitrephora chulabhorniana (MC) is the newly identified species; however, its biological functions including anticancer activities have been largely unexplored. Hence, in this study, we were interested in investigating anticancer effects of this plant on the human cervical cell line (HeLa). MC extract was profiled for phytochemicals by TLC. This plant was tested to contain alkaloids, flavonoids, and terpenes. HeLa cells were treated with MC extract to investigate the anticancer activities. Cytotoxicity and viability of cells treated with MC were determined by MTT assay and Trypan blue exclusion assay. Cell migration was tested by wound healing assay, and cell invasion was determined by Transwell assay. The level of caspase 7, caspase 9, and PARP was determined by western blot analysis. We found that the leaf extract of MC strongly reduced cancer cell survival rate. This finding was consistent with the discovery that the extract dramatically induced apoptosis of cervical cancer cells through the activation of caspase 7 and caspase 9 which consequently degraded PARP protein. Furthermore, MC extract at lower concentrations which were not cytotoxic to the cancer cells showed potent inhibitory activities against HeLa cervical cancer cell migration and invasion. Mitrephora chulabhorniana possesses its pharmacological properties in inhibiting cervical cancer cell migration/invasion and inducing apoptotic signaling. This accumulated information suggests that Mitrephora chulabhorniana may be a beneficial source of potential agents for cervical cancer treatment.

MICAL2 Promotes Proliferation and Migration of Glioblastoma Cells Through TGF-β/p-Smad2/EMT-Like Signaling Pathway

Recent studies showed that molecule interacting with CasL2 (MICAL2) could be a novel tumor growth factor, and it is closely associated with tumor growth and invasion. However, the role it plays in glioblastoma (GBM) and its potential mechanisms are currently unknown. Our study is designed to identify the effect of MICAL2 on GBM cells and the potential mechanisms behind it. Here, we found that MICAL2 interacts with TGF receptor-type I (TGFRI) and promotes the proliferation and migration of glioblastoma through the TGF-β/p-Smad2/EMT-like signaling pathway. MICAL2-knockdown inhibited the proliferation of glioblastoma cells, which was related to cell cycle arrest and downregulation of DNA replication. The invasion abilities of U87 and U251 cells were reduced after the knockdown of MICAL2. MICAL2 promoted the growth of GBM in nude mice. High MICAL2 predicts poor outcome of GBM patients. MICAL2 could be identified as a novel promising therapeutic target for human GBM.

Atorvastatin preferentially inhibits the growth of high ZEB-expressing canine cancer cells

The epithelial-to-mesenchymal transition (EMT) is fundamental in cancer progression and contributes to the acquisition of malignant properties. The statin class of cholesterol-lowering drugs exhibits pleiotropic anticancer effects in vitro and in vivo, and many epidemiologic studies have reported a correlation between statin use and reduced cancer mortality. We have shown previously that sensitivity to the anti-proliferative effect of statins varies among human cancer cells and statins are more effective against mesenchymal-like cells than epithelial-like ones in human cancers. There have only been few reports on the application of statins to cancer therapy in veterinary medicine, and differences in statin sensitivity among canine cancer cells have not been examined. In this study, we aimed to clarify the correlation between sensitivity to atorvastatin and epithelial/mesenchymal states in 11 canine cancer cell lines derived from mammary gland, squamous cell carcinoma, lung, and melanoma. Sensitivity to atorvastatin varied among canine cancer cells, with IC₅₀ values ranging from 5.92 to 71.5 μM at 48 h, which were higher than the plasma concentrations clinically achieved with statin therapy. Atorvastatin preferentially attenuated the proliferation of mesenchymal-like cells. In particular, highly statin-sensitive cells were characterized by aberrant expression of the ZEB family of EMT-inducing transcription factors. However, ZEB2 silencing in highly sensitive cells did not induce resistance to atorvastatin. Taken together, these results suggest that high expression of ZEB is a characteristic of highly statin-sensitive cells and could be a molecular marker for predicting whether cancers are sensitive to statins, though ZEB itself does not confer statin sensitivity.

Investigation of the Epithelial to Mesenchymal Transition (EMT) Process in Equine Papillomavirus-2 (EcPV-2)-Positive Penile Squamous Cell Carcinomas

Equine penile squamous cell carcinoma (epSCC) is the most frequent tumor of the external male genitalia, representing 67.5% of equine genital cancers. epSCC is associated with papilloma virus (PV) infection and has been recently proposed as a model for human PV-induced squamous cell carcinomas. It has already been suggested that epSCC might undergo epithelial-to-mesenchymal transition (EMT). This work aims to investigate in detail this process and the possible role of PV oncoproteins in epSCC. For this purpose, 18 penile SCCs were retrospectively selected and tested for both EcPV2 presence and oncoproteins (EcPV2 E6 and EcPV2 E7) expression. Moreover, immunohistochemical EMT characterization was carried out by analyzing the main epithelial markers (E-cadherin, β-catenin, and pan-cytokeratin AE3/AE1), the main mesenchymal markers (N-cadherin and vimentin), and the main EMT-related transcription factors (TWIST-1, ZEB-1). PCR analysis was positive for EcPV2 in 16 out of 18 samples. EMT was investigated in epSCC positive for EcPV2. The immunohistochemistry results suggested the presence of EMT processes in the neoplastic cells at the tumor invasive front. Moreover, the significant upregulation of RANKL, together with BCATN1, LEF1, and FOSL1 genes, might suggest a canonical Wnt pathway activation, similarly to what is reported in human penile squamous cell carcinomas

COX-2 Silencing in Canine Malignant Melanoma Inhibits Malignant Behaviour

Metastatic melanoma is a very aggressive form of cancer in both humans and dogs. Dogs primarily develop oral melanoma of mucosal origin. Although oral melanoma in humans is rare, both diseases are highly aggressive with frequent metastases. This disease represents a “One Health” opportunity to improve molecular and mechanistic understanding of melanoma progression. Accumulating evidence suggests that cyclooxygenase-2 (COX-2) may play a critical role in the malignant behaviour of melanoma. In this study we analysed 85 histologically confirmed melanomas from canine patients and showed that COX-2 is overexpressed in both oral and cutaneous melanomas and that COX-2 expression correlates with established markers of poor prognosis. To determine the role of COX-2 in melanoma we developed two melanoma cell lines with stable integration of an inducible doxycycline-regulated expression vector containing a COX-2 targeted micro-RNA (miRNA). Using this system, we showed that cellular proliferation, migration and invasion are COX-2 dependent, establishing a direct relationship between COX-2 expression and malignant behaviour in canine melanoma. We have also developed a powerful molecular tool to aid further dissection of the mechanisms by which COX-2 regulates melanoma progression.

LncRNA FBXL19-AS1 promotes proliferation and metastasis of cervical cancer through upregulating COL1A1 as a sponge of miR-193a-5p

BACKGROUND

Cervical cancer (CC) is one of the most common and malignant tumors in women. In this study, we aim to explore the role and mechanism of F-box and leucine rich repeat protein 19 antisense RNA 1 (FBXL19-AS1), a novel long-chain non coding RNA (lncRNA) with marked roles in a variety of tumors, in regulating the proliferation and metastasis of CC.

METHODS

The expression of FBXL19-AS1, miR-193a-5p and COL1A1 were detected by RT-PCR and western blot. Gain- and loss-of functional assays of FBXL19-AS1 and miR-193a-5p were performed in CC cell lines in vitro or in vivo. The proliferation, migration, invasion, apoptosis and epithelial-mesenchymal transition (EMT) of CC cells were determined.

RESULTS

FBXL19-AS1 and COL1A1 were significantly up-regulated in CC tissues, while miR-193a-5p was significantly down-regulated. Overexpression of FBXL19-AS1 significantly promoted the proliferation, migration, invasion, EMT and growth of CC cells and inhibited apoptosis, while knockdown of FBXL19-AS1 had the opposite effects. On the other hand, miR-193a-5p inhibited the proliferation and metastasis of CC cells. Mechanistically, FBXL19-AS1 functioned as a competitive endogenous RNA (ceRNA) and inhibited the expression of miR-193a-5p, which targeted at the 3'-UTR site of COL1A1 and negatively regulated COL1A1 expression.

CONCLUSIONS

FBXL19-AS1 promotes the proliferation and metastasis of CC cells by sponging miR-193a-5p and up-regulating COL1A1.

miR-199a-5p suppresses epithelial- mesenchymal-transition in anaplastic thyroid carcinoma cells via targeting Snail signals

MicroRNAs (miRNAs) have been validated to play prominent roles in the occurrence and development of anaplastic thyroid carcinoma (ATC). miR-199a-5p was previously reported to act as a tumor suppressor or oncomiRNA in various types of cancer. However, its accurate expression, function, and mechanism in ATC remain unclear. Here, we find that miR-199a-5p is significantly downregulated in ATC tissues compared with adjacent non-cancerous tissues. Overexpression of miR-199a-5p significantly inhibits migration and invasion of ATC cells in vitro, and lung metastasis in vivo. Importantly, miR-199a-5p suppresses epithelial-mesenchymal transition (EMT) both in vitro and in vivo by targeting Snail. Taken together, this study reveals that miR-199a-5p is critical to the EMT progression in ATC cells. Targeting the pathway described here may be a novel approach for inhibiting metastasis of ATC.

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.

Periostin induces epithelial‑to‑mesenchymal transition via the integrin α5β1/TWIST‑2 axis in cholangiocarcinoma

Periostin (PN) (also known as osteoblast-specific factor OSF-2) is a protein that in humans is encoded by the POSTN gene and has been correlated with a reduced survival of cholangiocarcinoma (CCA) patients, with the well-known effect of inducing epithelial-to-mesenchymal transition (EMT). The present study investigated the effect of PN, through integrin (ITG)α5β1, in EMT-mediated CCA aggressiveness. The alterations in EMT-related gene and protein expression were investigated by real-time PCR, western blot analysis and zymogram. The effects of PN on migration and the level of TWIST-2 were assessed in CCA cells with and without siITGα5 transfection. PN was found to induce CCA cell migration and EMT features, including increments in Twist-related protein 2 (TWIST-2), zinc finger protein SNAI1 (SNAIL-1), α-smooth muscle actin (ASMA), vimentin (VIM) and matrix metallopeptidase 9 (MMP-9), and a reduction in cytokeratin 19 (CK-19) together with cytoplasmic translocation of E-cadherin (CDH-1). Additionally, PN markedly induced MMP-9 activity. TWIST-2 was significantly induced in PN-treated CCA cells; this effect was attenuated in the ITGα5β1-knockdown cells and corresponded to reduced migration of the cancer cells. These results indicated that PN induced CCA migration through ITGα5β1/TWIST-2-mediated EMT. Moreover, clinical samples from CCA patients showed that higher levels of TWIST-2 were significantly correlated with shorter survival time. In conclusion, the ITGα5β1-mediated TWIST-2 signaling pathway regulates PN-induced EMT in CCA progression, and TWIST-2 is a prognostic marker of poor survival in CCA patients.

The expressions and prognostic implications of Twist and E-cadherin in adenocarcinomas of the gastroesophageal junction and proximal gastric carcinoma

Twist and E-cadherin are crucial for the development of different types of cancer; however, their clinical significance in adenocarcinoma of the gastroesophageal junction (AGE) remains unknown. Here, we investigated the correlation between the expression of Twist and E-cadherin and their impact on the clinical outcomes and prognosis of patients with AGE and proximal gastric carcinoma (PGC).Using immunohistochemistry, we determined the expression of Twist and E-cadherin in the tissue samples of patients with AGE and PGC. The correlation of the expression of Twist and E-cadherin with the clinicopathological factors was assessed by using the chi-square test, Fisher exact test, and non-parametric Mann-Whitney U test. The Kaplan-Meier method along with the log-rank test and Cox proportional-hazards model were used to evaluate the correlation of Twist and E-cadherin expression with the overall survival (OS) of patients.Overall, 94 patients with AGE (n = 45, 47.87%) or PGC (n = 49, 52.13%) who underwent primary tumor resection were included in this study. The median follow-up period was 40.5 months. We observed a significant difference in the smoking status (P < .001) and differentiation grade (P = .004) between patients with AGE and PGC. There was a significant association of a high Twist expression with T stage (only in PGC, P = .008), lymph node metastasis (AGE, P = .075; PGC, P = .051), and advanced pathological stages (AGE, P = .019; PGC, P = .006). A low E-cadherin expression showed similar results; however, it was not significantly associated with the advanced pathological stages of AGE (P = .372). A low E-cadherin expression was significantly associated with a low differentiation grade of AGE (P = .002). In addition, a significant inverse relationship was observed between Twist and E-cadherin expression. The Kaplan-Meier survival analysis and Cox regression analysis revealed that a high Twist expression and low E-cadherin expression were independent prognostic factors for short OS of patients with AGE or PGC.A high Twist expression or low E-cadherin expression was associated with unfavorable clinicopathological factors and independently predicted short OS of patients with AGE or PGC.

Immunohistochemical Features of Epithelial-Mesenchymal Transition in Feline Oral Squamous Cell Carcinoma

Feline oral squamous cell carcinoma (FOSCC) is an aggressive malignancy with invasive and metastatic behavior. It is poorly responsive to chemotherapy and radiation. Neoplastic epithelial-mesenchymal transition (EMT) portends highly malignant behavior and enhances resistance to therapy. In transitioning to a more malignant phenotype, carcinoma stem cells undergo transformation mediated by expression of proteins, endowing them with mesenchymal properties advantageous to cell survival. The goal of the current study was to identify proteins associated with EMT in FOSCC. This study documents protein expression patterns in 10 FOSCC biopsies and 3 FOSCC cell lines (SCCF1, SCCF2, SCCF3), compatible with an EMT phenotype. As markers of EMT, P-cadherin, N-cadherin, vimentin, nuclear transcription factors Twist and Snail, hypoxia inducible factor 1α (HIF-1α), programmed death ligand 1, and vascular endothelial growth factor D, as well as E-cadherin, were examined using immunohistochemistry, Western blot, and enzyme-linked immunosorbent assay. P-cadherin, Twist, HIF-1α, and programmed death ligand 1 were commonly expressed in biopsies and cell lines. N-cadherin, classically associated with EMT, was not highly expressed, and E-cadherin was coexpressed along with proteins characteristic of EMT in all specimens. Production of vascular endothelial growth factor A by cell lines, a process regulated by HIF-1α expression, was suppressed by the small-molecule inhibitor dasatinib. These data are consistent with EMT in FOSCC and shed light on cellular changes that could contribute to the aggressive behavior of FOSCC.

N-Acetyltransferase 10 Enhances Doxorubicin Resistance in Human Hepatocellular Carcinoma Cell Lines by Promoting the Epithelial-to-Mesenchymal Transition

Background

N-Acetyltransferase 10 (NAT10) has been reported to be expressed at high levels in hepatocellular carcinoma (HCC); however, its role in chemoresistance is unclear. This study is aimed at investigating whether NAT10 regulates the epithelial-mesenchymal transition (EMT) and chemoresistance in HCC.

Methods

HCC cell lines (Huh-7, Bel-7402, SNU387, and SNU449) were treated with remodelin, an inhibitor of NAT10, or transfected with small inhibitory RNAs (siRNAs) targeting NAT10 or Twist. The EMT was induced by hypoxia. The CCK-8 assay was used to quantify cell viability, the EdU incorporation assay to assess cell proliferation. siRNA knockdown efficiency and epithelial/mesenchymal marker expression were assessed by western blotting.

Results

Knockdown of NAT10 using siRNA or inhibition of NAT10 using remodelin increased the sensitivity of HCC cell lines to doxorubicin; similar effects were observed in cells transfected with the Twist siRNA. Inhibition of NAT10 using remodelin also reversed the ability of doxorubicin to induce the EMT in HCC cells. Furthermore, inhibiting NAT10 reversed the hypoxia-induced EMT. Finally, we confirmed that combining doxorubicin with remodelin delayed tumor growth and reduced tumor cell proliferation in a mouse xenograft model of HCC.

Conclusions

NAT10 may contribute to chemoresistance in HCC by regulating the EMT. The mechanism by which NAT10 regulates the EMT and doxorubicin sensitivity in HCC cells merits further investigation.

Differential expression and functions of Ehm2 transcript variants in lung adenocarcinoma

Ehm2 [also known as erythrocyte membrane protein band 4.1‑like protein 4B (EPB41L4B)] is a member of the NF2/ERM/4.1 superfamily. The overexpression of Ehm2 has been observed in metastatic cancer cells. Through alternative splicing, the Ehm2 gene produces two transcript variants that encode the two different isoforms, Ehm2/1 and Ehm2/2. The biological functions of these different Ehm2 transcript variants remain unclear. The present study aimed to determine the expression of the Ehm2 variants in lung adenocarcinoma and their involvement in the disease progression of the patients. The expression of Ehm2 transcript variants in human lung adenocarcinoma tissues was analyzed using immunohistochemistry and western blot analysis. Ehm2 variants were overexpressed or knocked down in A549 human lung adenocarcinoma cells. The consequent effects of the genetic modifications on the cellular functions of lung cancer cells were then examined using in vitro cell viability, invasion and migration assays. The expression of epithelial‑mesenchymal transition (EMT)‑related markers was evaluated by western blot analysis in the cell models. The association of Ehm2 variant expression with patient survival was analyzed using Kaplan‑Meier survival analysis. The expression of Ehm2/1 was significantly decreased in lung cancers compared with the paired normal lung tissues (P<0.05), while the Ehm2/2 protein levels were higher in the tumors than in the paired normal lung tissues, although this was not statistically significant. The overexpression of Ehm2/1 exerted inhibitory effects, while the knockdown of Ehm2/1 promoted the growth, invasion and migration of A549 cells in vitro. Ehm2/2 was expressed at low levels in the A549 cells and the enforced expression of Ehm2/2 significantly increased the invasiveness and migration of the A549 cells. Immunofluorescence staining revealed that Ehm2/1 was confined to the plasma membrane, while Ehm2/2 was observed at both the plasma membrane and cytoplasm. The overexpression of Ehm2/1 resulted in the upregulation of the epithelial marker, E‑cadherin, and in the decreased expression of the mesenchymal markers, N‑cadherin and Snail1, while the knockdown of Ehm2/1 and the enforced expression of Ehm2/2 had the opposite effects on the protein levels of EMT‑related markers. Kaplan‑Meier survival analysis revealed that higher Ehm2/1 transcript levels were associated with the longer survival of patients with lung adenocarcinoma, while the lower expression of Ehm2/2 exhibited a similar association with patient survival. Taken together, the two Ehm2 variants appear to be differentially expressed in lung adenocarcinoma. Ehm2/1 may function as a putative tumor suppressor in the disease progression of lung adenocarcinoma, while Ehm2/2 may have an opposite function.

Molecular carcinogenesis in equine penile cancer: A potential animal model for human penile cancer

OBJECTIVES

To evaluate the expression of COX-2, E-cadherin, vimentin, 14-3-3σ, and Phosphatase and tensin homolog (PTEN) tumor-related proteins in equine penile papillomas (ePP) and squamous cell carcinomas (ePSCC), the occurrence of epithelial-mesenchymal transition (EMT) at the invasion front (IF) and compare our findings with current knowledge on human penile squamous cell carcinoma (hPSCC).

MATERIAL AND METHODS

We analyzed, by immunohistochemistry in 45 equine penile proliferative epithelial lesions, the expression of COX-2, E-cadherin, vimentin, 14-3-3σ, and PTEN using monoclonal antibodies. Tumors were histopathologically classified as well-differentiated or poorly differentiated using the IF grading scheme. Semiquantitative analysis was performed to determine down or up-regulation of the proteins and association with histopathological characteristics were statistically investigated using Mann-Whitney U test and/or Spearman's tests.

RESULTS

COX-2 was neo-expressed in 86.6% of the cases and expression progressively increased from ePP to ePSCC (P = 0.0003) and from well to poorly differentiated (P = 0.033). High COX-2 expression was associated with a high mitotic index (MI) (P = 0.026). In contrast to normal epidermis, ePSCC had very low E-cadherin expression in 64% of the cases (P = 0.0005). Vimentin was neo-expressed in 65% of poorly differentiated ePSCC at the IF indicating EMT. Cytoplasmic 14-3-3σ protein expression was reduced in 42% of the ePSCC and additionally, nuclear expression of 14-3-3σ in neoplastic keratinocytes and in the cytoplasm of stromal fibroblasts at the IF was features only found in ePSCC. PTEN protein showed a tendency to be decreased or lost in ePSCC.

CONCLUSIONS

Our study provides evidence of molecular abnormalities in ePSCC similar to those reported for human PSCC. The occurrence of EMT at the IF is a common event in ePSCC. Naturally occurring ePSCC could serve as a valuable preclinical animal model to explore upcoming therapeutic options for hPSCC.

Ring finger protein 125, as a potential highly aggressive and unfavorable prognostic biomarker, promotes the invasion and metastasis of human gallbladder cancers via activating the TGF- β1-SMAD3-ID1 signaling pathway

Human gallbladder cancer (GBC) is a lethal aggressive malignant neoplasm. Identification of potential molecular biomarkers and development of targeted therapeutics for GBC patients is very necessary. In this study, we firstly investigated the correlation between ring finger protein 125 (RNF125) expression and the metastasis and prognosis of GBC, and the underlying molecular mechanism. RNF125 expression in a cohort of GBC tissues was examined; its correlation with clinicopathological and prognostic factors of GBC patients was analyzed. Moreover, the metastasis-related difference expressed genes in highly and lowly aggressive GBC cell lines were identified; and the influence of RNF125 knockdown on the metastatic phenotypes and characteristic EMT markers in highly aggressive GBC NOZ cells was detected. Furthermore, the underlying molecular mechanism of RNF125 effect was explored. The results showed that RNF125 was highly expressed in GBC tissues and related with aggressive characteristics such as Nevin stage (P = 0.041) etc. and unfavorable prognosis of GBC patients (P = 0.023, log-rank test). And, RNF125 was proved to a positive metastasis-related gene in vitro. RNF125 knockdown inhibited the invasion and migration, enhanced the adhesion, upregulated E-cadherin and β-catenin expression, and downregulated vimentin and N-cadherin expression (all P < 0.001) of NOZ cells in vitro. RNF125 promoting effect on GBC tumor progression was identified to relate with the activation of TGF-β1-SMAD3-ID1 signaling pathway. These findings firstly confirm that high RNF125 expression is related with aggressive characteristics and unfavorable prognosis of GBC patients; RNF125 promotes the invasion and metastasis of human GBCs via activating the TGF-β1-SMAD3-ID1 signaling pathway.

Deregulation of E-cadherin, β-catenin, APC and Caveolin-1 expression occurs in canine prostate cancer and metastatic processes

Prostate cancer is a heterogeneous disease with high levels of clinical and gene heterogeneity, consequently offering several targets for therapy. Dogs with naturally occurring prostate cancer are useful models for molecular investigations and studying new treatment efficacy. Three genes and proteins associated with the WNT pathway (β-catenin, APC and E-cadherin) and Caveolin-1 (CAV-1) were evaluated in canine pre-neoplastic proliferative inflammatory atrophy (PIA), prostate cancer and metastatic disease. The APC gene methylation status was also investigated. As in human prostate cancer, cytoplasmic and nuclear β-catenin, which are fundamental for activating the canonical WNT pathway, were found in canine prostate cancer and metastasis. Membranous E-cadherin was also lost in these lesions, allowing cellular migration to the stroma and nuclear localization of β-catenin. In contrast to human prostate tumours, no APC downregulation or hypermethylation was found in canine prostate cancer. The CAV-1 gene and protein overexpression were found in canine prostate cancer, and as in humans, the highest levels were found in Gleason scores ≥8. In conclusion, as with human prostate cancer, β-catenin and E-cadherin in the WNT pathway, as well as Caveolin-1, are molecular drivers in canine prostate cancer. These findings provide additional evidence that dogs are useful models for studying new therapeutic targets in prostate cancer.

MXR7 facilitates liver cancer metastasis via epithelial-mesenchymal transition

MXR7 is a cell-surface protein and highly expressed in hepatocellular carcinoma (HCC). The aim of this study is to determine the expression profile of MXR7 in HCC and investigate the influence of MXR7 on invasion and metastasis of HCC cells. For this purpose, immunohistochemical assay was used to identify the differential expression of MXR7 in 94 HCC specimens. Expression of MXR7 in 4 pairs of HCC and portal vein tumor thrombus (PVTT) was also tested. The motility of HCC cells were characterized by transwell migration and matrigel invasion assays. In vivo metastasis potential was determined via tail vein injection assay. Moreover, compared with noninvasive HCC tumors or human HCC cell lines with low metastatic potential, invasive HCC samples and HCC cell lines with high metastatic potential exhibited higher MXR7 expression. Furthermore, forced expression of MXR7 in SMMC-7721 promoted cell proliferation, migration and invasion in vitro and accelerated tumor growth and metastasis in vivo. Conversely, knockdown of MXR7 expression in HuH7 cells inhibited proliferation and motility of cells. Mechanically, overexpression of MXR7 promoted epithelial-mesenchymal transition (EMT) progress, and MXR7 depletion repressed the EMT phenotype. In conclusion, MXR7 is a mediator of EMT and metastasis in HCC and may serve as a novel therapeutic target.

Leucine-rich repeat-containing G protein-coupled receptor 4 (Lgr4) is necessary for prostate cancer metastasis via epithelial-mesenchymal transition

Prostate cancer is a highly penetrant disease among men in industrialized societies, but the factors regulating the transition from indolent to aggressive and metastatic cancer remain poorly understood. We found that men with prostate cancers expressing high levels of the G protein-coupled receptor LGR4 had a significantly shorter recurrence-free survival compared with patients with cancers having low LGR4 expression. LGR4 expression was elevated in human prostate cancer cell lines with metastatic potential. We therefore generated a novel transgenic adenocarcinoma of the mouse prostate (TRAMP) mouse model to investigate the role of Lgr4 in prostate cancer development and metastasis in vivo TRAMP Lgr4^-/- mice exhibited an initial delay in prostate intraepithelial neoplasia formation, but the frequency of tumor formation was equivalent between TRAMP and TRAMP Lgr4^-/- mice by 12 weeks. The loss of Lgr4 significantly improved TRAMP mouse survival and dramatically reduced the occurrence of lung metastases. LGR4 knockdown impaired the migration, invasion, and colony formation of DU145 cells and reversed epithelial-mesenchymal transition (EMT), as demonstrated by up-regulation of E-cadherin and decreased expression of the EMT transcription factors ZEB, Twist, and Snail. Overexpression of LGR4 in LNCaP cells had the opposite effects. Orthotopic injection of DU145 cells stably expressing shRNA targeting LGR4 resulted in decreased xenograft tumor size, reduced tumor EMT marker expression, and impaired metastasis, in accord with our findings in TRAMP Lgr4^-/- mice. In conclusion, we propose that Lgr4 is a key protein necessary for prostate cancer EMT and metastasis.

Downregulated connexin32 promotes EMT through the Wnt/β-catenin pathway by targeting Snail expression in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the common malignances in the world and is associated with high mortality and poor prognosis, partly due to early invasion and metastasis. Cx32 has been indicated to be involved in the progression of many cancers including HCC, but its relationship with tumor invasion and metastasis is still controversial. In the present study, the downregulated Cx32 in HCC tissue was found negatively correlated with histological grade and lymph node metastasis. Cx32 regulated HCC migration and invasion in vitro and inhibited tumor metastasis in xenograft models in vivo. We subsequently identified that Cx32 mediated epithelial-mesenchymal transition (EMT) by regulating Snail expression, and the enhanced Snail was due to activation of Wnt/β-catenin signaling in response to Cx32 inhibition. Finally, decreased expression of Cx32 showed strong correlation with loss/reduction of E-cadherin, higher expression of Snail, and nuclear accumulation of β-catenin in HCC tissues. Taken together, our results suggest that Cx32 inhibits HCC invasion and metastasis through Snail-mediated EMT, Cx32 and this signaling pathway molecules may offer potential targets for HCC cancer therapy.

Nobiletin inhibits invasion via inhibiting AKT/GSK3β/β-catenin signaling pathway in Slug-expressing glioma cells

Epithelial-mesenchymal transition (EMT) is a pivotal event in tumor progression during which cancer cells undergo dramatic changes acquiring highly invasive properties. In this study, we found that nobiletin, a polymethoxylated flavone, suppressed migration and invasion in both U87 and U251 glioma cells. Expression of epithelial markers (E-cadherin and occludin) was upregulated; mesenchymal markers (N-cadherin, fibronectin) and the transcriptional factor Slug were downregulated after nobiletin treatment. Transforming growth factor β (TGF-β) was applied to stimulate EMT and the results showed that nobiletin not only influenced basal level cell migration but also prevented TGF-β-triggered migration and EMT, with the AKT/GSK3β/β-catenin signaling pathway greatly involved. Furthermore, nobiletin remarkably diminished TGF-β-induced β-catenin nuclear translocation and the binding to the Slug promoter. It is worth noting that nobiletin almost blocked invasion in Slug-expressing U87 and U251 cells, and only exhibiting faint effect on non-Slug-expressing U343 glioma cells. Reinforced Slug expression in U343 cells by transfecting Slug plasmid was significantly attenuated by nobiletin, demonstrating the essential role of Slug in the anti-metastasis effect of nobiletin. Nobiletin repressed tumor growth in vivo and abrogated EMT in nude mice bearing U87-Luc xenografts, as demonstrated by Xenogen IVIS imaging and immunohistochemistry assay. Our findings suggested that nobiletin might have a great potential for treating glioblastoma.

Prostate-specific IL-6 transgene autonomously induce prostate neoplasm through amplifying inflammation in the prostate and peri-prostatic adipose tissue

Background

The causative role of the pro-inflammatory cytokine IL-6 in prostate cancer progression has been well established at molecular level. However, whether and how IL-6 may play a role in prostate cancer risk and development is not well defined. One limitation factor to acquiring this knowledge is the lack of appropriate animal models.

Methods

We generated a novel line of prostate-specific IL-6 transgenic mouse model. We compared the prostate pathology, tumorigenic signaling components, and prostate tumor microenvironment of the IL-6 transgenic mice with wild type littermates.

Results

With this model, we demonstrate that IL-6 induces prostate neoplasm autonomously. We further demonstrate that transgenic expression of IL-6 in the prostate activates oncogenic pathways, induces autocrine IL-6 secretion and steadily-state of STAT3 activation in the prostate tissue, upregulates paracrine insulin-like growth factor (IGF) signaling axis, reprograms prostate oncogenic gene expression, and more intriguingly, amplifies inflammation in the prostate and peri-prostatic adipose tissue.

Conclusions

The pro-inflammatory IL-6 is autonomous oncogene for the prostate. IL-6 induces prostate oncogenesis through amplifying local inflammation. We also presented a valuable animal model to study inflammation and prostate cancer development.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-016-0386-7) contains supplementary material, which is available to authorized users.

β-Lapachone Inhibits Lung Metastasis of Colorectal Cancer by Inducing Apoptosis of CT26 Cells

Background: β-Lapachone is a quinone-containing compound found in red lapacho (Tabebuia impetiginosa, syn. T avellanedae) trees. Lapacho has been used in traditional medicine by several South and Central American indigenous people to treat various types of cancer. The purpose of this study was to investigate the antimetastatic properties of β-lapachone and the underlying mechanisms using colon cancer cells. Methods: This research used metastatic murine colon cancer cell lines, colon 26 (CT26) and colon 38 (MC38). A WST assay, annexin V assay, cell cycle analysis, wound healing assay, invasion assay, western blot analysis, and real-time reverse transcription–polymerase chain reaction were performed to examine the effects of β-lapachone on metastatic phenotypes and molecular mechanisms. The effect of β-lapachone on lung metastasis was assessed in a mouse experimental metastasis model. Results: We found that the inhibition of proliferation of the colon cancer cell lines by β-lapachone was due to the induction of apoptosis and cell cycle arrest. β-Lapachone induced the apoptosis of CT26 cells through caspase-3, -8, and -9 activation; poly(ADP-ribose) polymerase cleavage; and downregulation of the Bcl-2 family in a dose- and time-dependent manner. In addition, a low concentration of β-lapachone decreased the cell migration and invasion by decreasing the expression of matrix metalloproteinases-2 and -9, and increased the expression of tissue inhibitors of metalloproteinases-1 and -2. Moreover, β-lapachone treatment regulated the expression of epithelial-mesenchymal transition markers such as E- and N-cadherin, vimentin, β-catenin, and Snail in CT26 cells. In the mouse experimental metastasis model, β-lapachone significantly inhibited the lung metastasis of CT26 cells. Conclusions: Our results demonstrated the inhibitory effect of β-lapachone on colorectal lung metastasis. This compound may be useful for developing therapeutic agents to treat metastatic cancer.

Oridonin inhibition and miR‑200b‑3p/ZEB1 axis in human pancreatic cancer

The relationship among oridonin, miR-200b-3p and pancreatic cancer on epithelial-to-mesenchymal transition (EMT) was investigated for the molecular mechanism or signaling pathways on the migration in pancreatic cancer. BxPC-3 and PANC-1 cells were cultivated and the IC50 of oridonin in BxPC-3 and PANC-1 cells were obtained by the CCK-8 array. The expression of miR‑200b-3p was verified by using real-time PCR and its target gene was predicted. BxPC-3 and PANC-1 cells were treated with oridonin or transfected by miR-200b-3p, those cells were used for western blot assay, Transwell assay, ELISA, immunofluorescence staining, tumorigenesis assay in nude mice and immunohistochemical assay to verify the effects of oridonin or miR-200b-3p on pancreatic cancer. We found that oridonin inhibited the proliferation of BxPC-3 and PANC-1 cells in a dose-dependent manner. miR-200b-3p was downregulated by oridonin in BxPC-3 and PANC-1 cells. ZEB1 was a target gene for miR-200b-3p. Oridonin or overexpression of miR‑200b-3p can inhibit the cell migration in BxPC-3 and PANC-1 cells. miR-200b-3p can inhibit the EMT and oridonin can inhibit the expression of ZEB1, N-cadherin and fibronectin but not increase the expression of E-cadherin, while the cell adhesion molecules ICAM-1 and VCAM-1 were decreased by oridonin in BxPC-3 and PANC-1 cells and the cytoskeleton was altered by oridonin in PANC-1 cells compared with the control. In summary, the results demonstrate that miR‑200b-3p was able to inhibit the EMT of human pancreatic cancer in vivo and in vitro by targeted ZEB1. In vitro, oridonin had a certain effect on the migration in BxPC-3 and PANC-1 cells, but not though type III EMT by miR-200-3p/ZEB1 axis, and may be related to type Ⅱ EMT, tumor microenvironment or altering the cytoskeleton. In vivo, oridonin inhibited the cancer migration in the nude mouse model though inhibiting EMT.

Upregulation of flotillin-1 promotes invasion and metastasis by activating TGF-β signaling in nasopharyngeal carcinoma

Metastasis is the main cause of cancer-related deaths. Nasopharyngeal carcinoma (NPC) is characterized by severe local invasion and high incidence of regional lymph node metastasis, which represents poor prognosis. However, the underlying mechanism that induces lymph node metastasis of NPC remains largely unknown. Herein, we report that flotillin-1 (FLOT1), a component of lipid raft, which was reported to be involved in tumor progression, was robustly upregulated in the NPC samples with lymph node metastasis. High FLOT1 expression was significantly associated with N classification as well as poorer overall and disease-free survivals in 169 archived clinical NPC samples. Overexpression of FLOT1 enhanced the migratory and invasive abilities of NPC cells in vitro, and more importantly, promoted invasion into the surrounding tissues and metastasis to lymph nodes in vivo. Whereas silencing of endogenous FLOT1 in NPC cells decreased the local invasion and metastasis to lymph nodes. Furthermore, FLOT1 induced the expression and secretion of TGF-β1, facilitated the activation of TGF-β/Smad3 signaling to effectuate epithelial-mesenchymal transition. Our findings present new evidence that FLOT1 plays an important role in promoting aggressive behavior of NPC and provide new insights into the regulatory mechanism of TGF-β signaling.

Zinc finger E-box-binding homeobox 1: its clinical significance and functional role in human thyroid cancer

Objective

Transcription factor zinc finger E-box-binding homeobox 1 (ZEB1), as one of the key inducers of epithelial-mesenchymal transition, has been reported to be regulated by microRNA-144 and Bcl-2-associated athanogene 3, which both promote thyroid cancer cell invasion. However, the involvement of ZEB1 in thyroid cancer has not been fully elucidated. In this study, we aimed to investigate the role and clinical implication of ZEB1 in this disease.

Methods

Immunohistochemistry was performed to examine the subcellular localization and the expression level of ZEB1 protein in 82 self-pairs of formalin-fixed and paraffin-embedded cancerous and adjacent noncancerous tissues obtained from patients with thyroid cancer. The roles of ZEB1 in thyroid cancer cell migration, invasion, and proliferation were also detected by transwell and MTT analyses, respectively.

Results

Immunohistochemistry showed that ZEB1 was predominantly localized in the nucleus of thyroid cancer cells. Its immunoreactive score in thyroid cancer tissues was significantly higher than that in adjacent noncancerous tissues (P=0.01). In addition, ZEB1 overexpression was significantly associated with the advanced tumor node metastasis staging (P=0.008), the positive lymph node metastasis (P=0.01) and distant metastasis (P=0.02). Furthermore, ZEB1 knockdown by siRNA could efficiently inhibit the migration, invasion, and proliferation abilities of thyroid cancer cells in vitro.

Conclusion

These findings indicated that ZEB1 might function as an oncogene, the overexpression of which was associated with the aggressive tumor progression of human thyroid cancer. Interestingly, ZEB1 also could promote thyroid cancer cell migration, invasion, and proliferation, suggesting that the inhibition of this protein might be a therapeutic strategy for the treatment of this malignancy.

A three-dimensional cell culture system as an in vitro canine mammary carcinoma model for the expression of connective tissue modulators

In this study, derived complex carcinoma (CC) and simple carcinoma (SC) cell lines were established and cultured under two-dimensional (2D) and three-dimensional (3D) conditions. The 3D was performed in six-well AlgiMatrix™ (LifeTechnologies®, Carlsbad, CA, USA) scaffolds, resulting in spheroids sized 50-125 µm for CC and 175-200 µm for SC. Cell viability was demonstrated up to 14 days for both models. Epidermal growth factor receptor (EGFR) was expressed in CC and SC in both systems. However, higher mRNA and protein levels were observed in SC 2D and 3D systems when compared with CC (P < 0.005). The connective tissue modulators, metalloproteinases-1, -2, -9 and -13 (MMPs), relaxin receptors 1 and 2 (RXR1 and RXR2) and E-cadherin (CDH1) were quantitated. All were upregulated similarly when canine mammary tumour (CMT)-derived cell lines were cultured under 3D AlgiMatrix, except CDH1 that was downregulated (P < 0.005). These results are promising towards the used of 3D system to increase a high throughput in vitro canine tumour model.

Lapatinib-induced mesenchymal-epithelial transition in squamous cell carcinoma cells correlates with unexpected alteration of β-catenin expression

The epithelial-mesenchymal transition (EMT) is a key developmental program that is often activated during cancer progression, and may promote resistance of cancer cells to therapy. Inhibiting EMT appears to be crucial to inhibit drug resistance. The mesenchymal-epithelial transition (MET), which is the reverse program of EMT in metastases, is characterized by the upregulation of epithelial adhesive proteins such as E-cadherin, and downregulation of mesenchymal proteins such as vimentin. The sensitivity of cancer cells to epithelial growth factor receptor (EGFR) inhibitor may be increased by inducing MET in these cells. Therefore, it is of clinical importance to specify the phenotype of cancer cells in order to overcome the phenomenon of drug resistance. The aim of the present study was to investigate the expression pattern of specific markers in squamous cell carcinoma (SCC) cells following stimulation with lapatinib and gefitinib. For this purpose, the head and neck (HN) SCC cell lines HNSCC22B and HNSCC11A were incubated with 0.5 and 2 µg/ml lapatinib and gefitinib, and the levels of E-cadherin, vimentin, matrix metalloproteinase-14, c-kit and β-catenin were detected by immunocytochemistry and enzyme-linked immunosorbent assay at 5, 24 and 96 h post-incubation. The results indicated that, compared with HNSCC22B cells, the protein expression levels of vimentin increased, whereas those of E-cadherin reduced, in non-stimulated HNSCC11A cells. In addition, the protein expression levels of β-catenin were altered in the epithelial- and mesenchymal-associated SCC cell lines following treatment with lapatinib and gefitinib. Furthermore, lapatinib induced the downregulation of vimentin and upregulation of E-cadherin in HNSCC11A cells in a time-dependent manner. This suggests that the sensitivity of cancer cells to lapatinib may be improved by inducing MET in these cells. In summary, the results of the present study demonstrated that lapatinib-induced MET led to an unexpected alteration of the protein expression levels of β-catenin in SCC cells. Further studies on the mechanistic role of MET are required in order to increase the sensitivity of cancer cells to EGFR inhibitor and block the EMT process in these cells.

Histological and immunohistochemical characterization of feline renal cell carcinoma: a case series

Four feline renal cell carcinomas (RCCs) were examined using histopathological and immunohistochemical procedures. Specimens were classified by predominant histological pattern according to WHO criteria. A panel of antibodies including β-catenin, C-KIT, VEGF and VEGF-R2 and double immunostaining for vimentin/cytokeratin and for E-cadherin/CD10 was selected to characterize the tumors. Neoplasms were classified as tubular (3/4) and papillary (1/4). Neoplastic epithelial cells were cytokeratin, vimentin, E-cadherin, VEGF-R2 positive and C-KIT negative; 3 cases were β-catenin positive, whereas only 2 tumors were CD10 and VEGF positive. No correlation with histotype was evident. Our results confirm the low frequency of RCCs in cats and suggest a histological pattern similar to canine RCCs. In contrast, a peculiar immunohistochemical profile different from both canine and human RCCs is identified.

Substrate stiffness modulates lung cancer cell migration but not epithelial to mesenchymal transition

Biomechanical properties of the tumor microenvironment, including matrix/substrate stiffness, play a significant role in tumor evolution and metastasis. Epithelial to Mesenchymal Transition (EMT) is a fundamental biological process that is associated with increased cancer cell migration and invasion. The goal of this study was to investigate (1) how substrate stiffness modulates the migration behaviors of lung adenocarcinoma cells (A549) and (2) if stiffness-induced changes in cell migration correlate with biochemical markers of EMT. Collagen-coated polydimethylsiloxane (PDMS) substrates and an Ibidi migration assay were used to investigate how substrate stiffness alters the migration patterns of A549 cells. RT-PCR, western blotting and immunofluorescence were used to investigate how substrate stiffness alters biochemical markers of EMT, that is, E-cadherin and N-cadherin, and the phosphorylation of focal adhesion proteins. Increases in substrate stiffness led to slower, more directional migration but did not alter the biochemical markers of EMT. Interestingly, growth factor (i.e., Transforming Growth Factor-β) stimulation resulted in similar levels of EMT regardless of substrate stiffness. We also observed decreased levels of phosphorylated focal adhesion kinase (FAK) and paxillin on stiffer substrates which correlated with slower cell migration. These results indicate that substrate stiffness modulates lung cancer cell migration via focal adhesion signaling as opposed to EMT signaling.

Low adherent cancer cell subpopulations are enriched in tumorigenic and metastatic epithelial-to-mesenchymal transition-induced cancer stem-like cells

Cancer stem cells are responsible for tumor progression, metastasis, therapy resistance and cancer recurrence, doing their identification and isolation of special relevance. Here we show that low adherent breast and colon cancer cells subpopulations have stem-like properties. Our results demonstrate that trypsin-sensitive (TS) breast and colon cancer cells subpopulations show increased ALDH activity, higher ability to exclude Hoechst 33342, enlarged proportion of cells with a cancer stem-like cell phenotype and are enriched in sphere- and colony-forming cells in vitro. Further studies in MDA-MB-231 breast cancer cells reveal that TS subpopulation expresses higher levels of SLUG, SNAIL, VIMENTIN and N-CADHERIN while show a lack of expression of E-CADHERIN and CLAUDIN, being this profile characteristic of the epithelial-to-mesenchymal transition (EMT). The TS subpopulation shows CXCL10, BMI-1 and OCT4 upregulation, differing also in the expression of several miRNAs involved in EMT and/or cell self-renewal such as miR-34a-5p, miR-34c-5p, miR-21-5p, miR-93-5p and miR-100-5p. Furthermore, in vivo studies in immunocompromised mice demonstrate that MDA-MB-231 TS cells form more and bigger xenograft tumors with shorter latency and have higher metastatic potential. In conclusion, this work presents a new, non-aggressive, easy, inexpensive and reproducible methodology to isolate prospectively cancer stem-like cells for subsequent biological and preclinical studies.

Protein kinase C-dependent regulation of human hepatic drug transporter expression

Hepatic drug transporters are now recognized as major actors of hepatobiliary elimination of drugs. Characterization of their regulatory pathways is therefore an important issue. In this context, the present study was designed to analyze the potential regulation of human hepatic transporter expression by protein kinase C (PKC) activation. Treatment by the reference PKC activator phorbol 12-myristate 13-acetate (PMA) for 48h was shown to decrease mRNA expression of various sinusoidal transporters, including OATP1B1, OATP2B1, NTCP, OCT1 and MRP3, but to increase that of OATP1B3, whereas mRNA expression of canalicular transporters was transiently enhanced (MDR1), decreased (BSEP and MRP2) or unchanged (BCRP) in human hepatoma HepaRG cells. The profile of hepatic transporter mRNA expression changes in PMA-treated HepaRG cells was correlated to that found in PMA-exposed primary human hepatocytes and was similarly observed in response to the PKC-activating marketed drug ingenol mebutate. It was associated with concomitant repression of OATP1B1 and OATP2B1 protein expression and reduction of OATP, OCT1, NTCP and MRP2 activity. The use of chemical PKC inhibitors further suggested a contribution of novel PKCs isoforms to PMA-mediated regulations of transporter mRNA expression. PMA was finally shown to cause epithelial-mesenchymal transition (EMT) in HepaRG cells and exposure to various additional EMT inducers, i.e., hepatocyte growth factor, tumor growth factor-β1 or the HNF4α inhibitor BI6015, led to transporter expression alterations highly correlated to those triggered by PMA. Taken together, these data highlight PKC-dependent regulation of human hepatic drug transporter expression, which may be closely linked to EMT triggered by PKC activation.

Inflammation and cancer: till death tears them apart

Advances in biotechnology have enabled the collection of an immeasurable amount of information from genomic, transcriptomic, metabolomic and proteomic studies of tumours within their microenvironments. The dissection of cytokine and chemokine networks has provided new clues to the interactions between cancer cells and their surrounding inflammatory landscape. To bridge the gap between chronic inflammation and cancer, dynamic participants in the tumour microenvironment have been identified, including tumour-associated macrophages (TAMs) and regulatory T cells (Tregs). Both of these cell types are notable for their ability to cause immunosuppressive conditions and support the evasion of tumour immune surveillance. It is clear now that the tumour-promoting inflammatory environment has to be included as one of the major cancer hallmarks. This review explores the recent advances in the understanding of cancer-related inflammation and how this is being applied to comparative oncology studies in humans and domestic species, such as the dog.