Deconstructing the mechanisms and consequences of TGF-β-induced EMT during cancer progression

HIV-1 proteins gp120 and tat induce the epithelial-mesenchymal transition in oral and genital mucosal epithelial cells

The oral, cervical, and genital mucosa, covered by stratified squamous epithelia with polarized organization and strong tight and adherens junctions, play a critical role in preventing transmission of viral pathogens, including human immunodeficiency virus (HIV). HIV-1 interaction with mucosal epithelial cells may depolarize epithelia and disrupt their tight and adherens junctions; however, the molecular mechanism of HIV-induced epithelial disruption has not been completely understood. We showed that prolonged interaction of cell-free HIV-1 virions, and viral envelope and transactivator proteins gp120 and tat, respectively, with tonsil, cervical, and foreskin epithelial cells induces an epithelial-mesenchymal transition (EMT). EMT is an epigenetic process leading to the disruption of mucosal epithelia and allowing the paracellular spread of viral and other pathogens. Interaction of cell-free virions and gp120 and tat proteins with epithelial cells substantially reduced E-cadherin expression and activated vimentin and N-cadherin expression, which are well-known mesenchymal markers. HIV gp120- and tat-induced EMT was mediated by SMAD2 phosphorylation and activation of transcription factors Slug, Snail, Twist1 and ZEB1. Activation of TGF-β and MAPK signaling by gp120, tat, and cell-free HIV virions revealed the critical roles of these signaling pathways in EMT induction. gp120- and tat-induced EMT cells were highly migratory via collagen-coated membranes, which is one of the main features of mesenchymal cells. Inhibitors of TGF-β1 and MAPK signaling reduced HIV-induced EMT, suggesting that inactivation of these signaling pathways may restore the normal barrier function of mucosal epithelia.

Evolution of placental invasion and cancer metastasis are causally linked

Among mammals, placental invasion is correlated with vulnerability to malignancy. Animals with more invasive placentation (e.g. humans) are more vulnerable to malignancy. To explain this correlation, we propose the hypothesis of Evolved Levels of Invasibility: the evolution of invasibility of stromal tissue affects both, placental and cancer invasion. We provide evidence for this hypothesis using an in vitro model. We find that bovine endometrial and skin fibroblasts are more resistant to invasion than their human counterparts. Gene expression profiling identified genes with high expression in human but not in bovine fibroblasts. Knocking down a subset of them in human fibroblasts leads to stronger resistance to cancer cell invasion. Identifying the evolutionary determinants of stromal invasibility can provide significant insights to develop rational anti-metastatic therapeutics.

JMJD3 in the regulation of human diseases

In recent years, many studies have shown that histone methylation plays an important role in maintaining the active and silent state of gene expression in human diseases. The Jumonji domain-containing protein D3 (JMJD3), specifically demethylate di- and trimethyl-lysine 27 on histone H3 (H3K27me2/3), has been widely studied in immune diseases, infectious diseases, cancer, developmental diseases, and aging related diseases. We will focus on the recent advances of JMJD3 function in human diseases, and looks ahead to the future of JMJD3 gene research in this review.

JMJD3 promotes the epithelial-mesenchymal transition and migration of glioma cells via the CXCL12/CXCR4 axis

Histone H3K27 demethylase Jumonji domain-containing protein 3 (JMJD3) is involved in somatic cell differentiation and tumor progression; however, the underlying mechanisms of JMJD3 in cancer progression are yet to be fully explored. To improve understanding regarding the function of JMJD3 in brain tumor cells, the present study investigated the effects of JMJD3 on the epithelial-mesenchymal transition (EMT) and migration in glioma cells, and the underlying mechanisms involving the C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C motif chemokine receptor 4 (CXCR4) axis. Immunohistochemical staining of a tissue microarray of glioma samples confirmed that JMJD3 overexpression could stratify highly metastatic glioma. The overexpression of JMJD3 induced a spindle-shaped morphology, promoted N-cadherin expression, inhibited E-cadherin expression and enhanced the migration ability of U-251MG and U-87MG American Type Culture Collection cells. The expression of E-cadherin and N-cadherin were assessed by western blotting and reverse transcription-quantitative polymerase chain reaction, and cell migration was evaluated using a Transwell migration assay and wound-healing. The overexpression of JMJD3 upregulated CXCL12 expression in a demethylase activity-dependent manner as ChIP assays revealed a decrease in H3K27 trimethylation at the CXCL12 promoter following overexpression of JMJD3 in U-87MG ATCC cells. Accordingly, CXCL12 overexpression was sufficient to rescue the suppressive effects of JMJD3 inhibition on the EMT and migration in glioma cells. In addition, CXCR4 expression was not regulated by JMJD3, but the interruption of CXCR4 caused by the CXCR4 inhibitor AMD3100 abolished the promotional effect of JMJD3 on EMT and migration in glioma cells. Collectively, these results suggested that JMJD3 promoted EMT and migration in glioma cells via the CXCL12/CXCR4 axis. The present study described a novel epigenetic mechanism regulating tumor cell EMT and migration, and provided a novel direction for glioma diagnosis and treatment.

Low Vitamin D Status Is Associated with Epithelial-Mesenchymal Transition in Patients with Chronic Obstructive Pulmonary Disease

Vitamin D deficiency is correlated with the increased morbidity of chronic obstructive pulmonary disease (COPD). However, the mechanisms underlying these effects have largely remained elusive. This study analyzed the correlations among COPD, vitamin D concentration, and epithelial-mesenchymal transition (EMT). Ninety-five patients with newly diagnosed COPD and 190 age- and sex-matched healthy subjects were recruited for this research. Serum 25(OH)D levels were detected, and pulmonary EMT biomarkers and TGF-β/Smad signaling were evaluated. Serum 25(OH)D level was remarkably decreased in COPD patients compared with that in control subjects. Furthermore, serum 25(OH)D concentration gradually decreased in COPD patients ranging from grade 1-2 to 4. However, reduced expression of the epithelial biomarker E-cadherin and increased expression of the mesenchymal biomarkers vimentin and α-SMA were found in COPD patients. Mechanistic analysis showed that pulmonary nuclear vitamin D receptor (VDR) was decreased in patients with COPD. In contrast, TGF-β/Smad signaling was obviously activated in COPD patients. Furthermore, the level of serum TGF-β in COPD patients increased in parallel with COPD severity. Serum 25(OH)D concentration was inversely associated with TGF-β levels in COPD patients. In vitro experiments showed that active vitamin D3 inhibits TGF-β-induced Smad2/3 phosphorylation in MRC-5 cells. Furthermore, vitamin D concentration was inversely correlated with TGF-β/Smad signaling and EMT in COPD patients, suggesting EMT as a vital mediator of COPD development in patients with low vitamin D concentrations.

MicroRNA-23b-3p promotes the proliferation, migration, and epithelial-mesenchymal transition of lens epithelial cells by targeting Sprouty2

Cataract, opacification of the lens, is one of the most important reasons of visual impairment and blindness. Though microRNAs (miRNAs) have been demonstrated to play important roles in cataractogenesis, the underlying molecular mechanisms in this progress remain obscure. In the present study, microRNA-23b-3p (miR-23b) overexpression promoted the proliferation, migration and epithelial-mesenchymal transition (EMT), whereas miR-23b knockdown markedly inhibited the proliferation, migration and TGF-β-induced EMT of lens epithelial cells (LECs). In TGF-β-induced LECs, the expression of miR-23b was markedly upregulated and the expression of Sprouty2 (SPRY2) was markedly downregulated, furthermore the mRNA and protein levels of SPRY2 were markedly decreased in miR-23b inhibitor-transfected LECs. We then performed a Dual-luciferase reporter assay to confirm that miR-23b directly targeted SPRY2. The promoted migration and EMT of LECs by enforced expression of miR-23b were suppressed by SPRY2 overexpression. The findings present the first evidence indicating that miR-23b can promote the proliferation, migration, and EMT of LECs by targeting SPRY2 and the inhibition of miR-23b may possess the therapeutic potential for cataract.

FMNL1 down-regulation suppresses bone metastasis through reducing TGF-β1 expression in non-small cell lung cancer (NSCLC)

Approximately 40% of patients with non-small cell lung cancer (NSCLC) develop bone metastasis. The formin protein formin-like 1 (FMNL1) plays a key role in the pathogenic processes of hematopoietic malignancies, and has been reported to be associated with the progression of multiple types of cancer. In the study, we found that FMNL1 expression was markedly up-regulated in primary NSCLC samples, and stronger expression of FNML1 was detected in bone metastasis. Reducing FMNL1 expression significantly suppressed cell proliferation in NSCLC cells. We also investigated the functional effects of FMNL1 knockdown on the inhibition of migration and invasion by meditating the expression of epithelial to mesenchymal transition (EMT)-associated signals in NSCLC cells. The transforming growth factor-β1 (TGF-β1)/SMADs signaling pathway was repressed in FMNL1-knockdown NSCLC cells. Further studies indicated that additional treatment with TGF-β1 could markedly abrogate FMNL1 knockdown-induced suppression of migration and invasion in NSCLC cells. In addition, NSCLC cell-induced osteoclastogenesis was also inhibited by FMNL1 deletion, as evidenced by the down-regulated expression of tartrate-resistant acid phosphatase (TRAP) and NFATc1. In vivo studies confirmed the results that FMNL1 knockdown markedly limited tumor growth. Importantly, decreasing FMNL1 reduced bone metastasis ability in vivo. Therefore, our results demonstrated that suppressing FMNL1 expression could inhibit bone metastasis in NSCLC through blocking TGF-β1 signaling, and FMNL1 might be a novel target for developing effective therapeutic strategy to limit the bone metastasis of NSCLC.

SOX4: Epigenetic regulation and role in tumorigenesis

Sex-determining region Y-related (SRY) high-mobility group box 4 (SOX4) is a member of the group C subfamily of SOX transcription factors and promotes tumorigenesis by endowing cancer cells with survival, migratory, and invasive capacities. Emerging evidence has highlighted an unequivocal role for this transcription factor in mediating various signaling pathways involved in tumorigenesis, epithelial-to-mesenchymal transition (EMT), and tumor progression. During the last decade, numerous studies have highlighted the epigenetic interplay between SOX4-targeting microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and SOX4 and the subsequent modulation of tumorigenesis, invasion and metastasis. In this review, we summarize the current state of knowledge about the role of SOX4 in cancer development and progression, the epigenetic regulation of SOX4, and the potential utilization of SOX4 as a diagnostic and prognostic biomarker and its depletion as a therapeutic target.

Immune checkpoint inhibitors for small cell lung cancer: opportunities and challenges

Lung cancer is the most common cancer and the leading cause of cancer death worldwide, with an estimated 2.1 million new cases and 1.8 million deaths in 2018. Although small cell lung cancer (SCLC) is the most aggressive type of lung cancer, it shows high response rates to chemotherapy in early lines of therapy. Unfortunately, it is associated with rapid recurrence and relatively poor prognosis. Over the last few years, considerable progress has been made in cancer immunotherapy. One of the most promising ways to activate therapeutic antitumor immunity is via blockade of immune checkpoints, such as cytotoxic T lymphocyte-associated protein-4 (CTLA-4) and programmed cell death protein-1/programmed cell death ligand-1 (PD-1/PD-L1). Immune checkpoint inhibitors show promise as SCLC therapeutics. The overall expectation for immuno-oncology is high, and the outcomes of trials will hopefully reveal a variety of treatment options for SCLC patients. In this review, we discuss the discovery of new immune inhibitory and stimulatory pathways and rational combination strategies to explain the role of immunotherapy in SCLC and its future opportunities and challenges.

Reproducibility of novel immune-inflammatory biomarkers over 4 months: an analysis with repeated measures design

Aim: Assessment of the feasibility and reliability of immune-inflammatory biomarker measurements. Methods: The following biomarkers were assessed in 207 predominantly healthy participants at baseline and after 4 months: MMF, TGF-β, suPAR and clusterin. Results: Intraclass correlation coefficients (95% CIs) ranged from good for TGF-β (0.75 [95% CI: 0.33-0.90]) to excellent for MMF (0.81 [95% CI: 0.64-0.90]), clusterin (0.83 [95% CI: 0.78-0.87]) and suPAR (0.91 [95% CI: 0.88-0.93]). Measurement of TGF-β was challenged by the large number of values below the detection limit. Conclusion: Single measurements of suPAR, clusterin and MMF could serve as feasible and reliable biomarkers of immune-inflammatory pathways in biomedical research.

WASF3 expression correlates with poor prognosis in gastric cancer patients

Aim: WASF3 has been shown to be required for invasion and metastasis in different cancers, this study is to explore the prognostic value of WASF3 in gastric cancer. Materials & methods: The coexpression of WASF3 and E-cadherin in gastric cancer patients and cells were evaluated. Results: WASF3 was overexpressed and the expression of E-cadherin was decreased in gastric cancer tissues compared with normal tissues (p < 0.001). WASF3 expression is associated with decreased expression of E-cadherin (p = 0.002). Patients with WASF3-positive expression had a poorer prognosis. The multivariate analysis showed that WASF3 expression is an independent prognostic factor related to overall survival (p = 0.027). Conclusion: Our analysis demonstrates that WASF3 expression correlates with poor outcomes and is a potential prognostic factor in gastric cancer patients.

Spleen Tyrosine Kinase-Mediated Autophagy Is Required for Epithelial-Mesenchymal Plasticity and Metastasis in Breast Cancer

The ability of breast cancer cells to transiently transition between epithelial and mesenchymal states contributes to their metastatic potential. Therefore, driving tumor cells into a stable mesenchymal state, as opposed to complete tumor cell eradication, presents an opportunity to pharmacologically limit disease progression by promoting an asymptomatic state of dormancy. Here, we compare a reversible model of epithelial-mesenchymal transition (EMT) induced by TGFβ to a stable mesenchymal phenotype induced by chronic exposure to the ErbB kinase inhibitor lapatinib. Only cells capable of returning to an epithelial phenotype resulted in skeletal metastasis. Gene expression analyses of the two mesenchymal states indicated similar transition expression profiles. A potently downregulated gene in both datasets was spleen tyrosine kinase (SYK). In contrast to this similar diminution in mRNA, kinome analyses using a peptide array and DNA-conjugated peptide substrates showed a robust increase in SYK activity upon TGFβ-induced EMT only. SYK was present in cytoplasmic RNA processing depots known as P-bodies formed during the onset of EMT, and SYK activity was required for autophagy-mediated clearance of P-bodies during mesenchymal-epithelial transition (MET). Genetic knockout of autophagy-related 7 (ATG7) or pharmacologic inhibition of SYK activity with fostamatinib, a clinically approved inhibitor of SYK, prevented P-body clearance and MET, inhibiting metastatic tumor outgrowth. Overall, this study suggests assessment of SYK activity as a biomarker for metastatic disease and the use of fostamatinib as a means to stabilize the latency of disseminated tumor cells. SIGNIFICANCE: These findings present inhibition of spleen tyrosine kinase as a therapeutic option to limit breast cancer metastasis by promoting systemic tumor dormancy.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/8/1831/F1.large.jpg.See related commentary by Farrington and Narla, p. 1756.

Lulling the Cancer Cell into an Eternal Sleep

A hallmark of metastasis is the ability of cancer cells to undergo the epithelial-to-mesenchymal transition to invade and disseminate to distal sites. More recently, the case has been made that the critical last step in metastasis is dependent on the ability to undergo reversion to an epithelial phenotype in a process known as the mesenchymal-to-epithelial transition (MET). It is this transition in the metastatic cascade that researchers are focusing on clinically to treat disseminated disease. Shinde and colleagues identified spleen tyrosine kinase (SYK) as a critical mediator of MET that facilitated the removal of P-bodies during autophagy. Remarkably, pharmacologic inhibition of SYK inhibited the clearance of P-bodies and autophagy in preclinical models of metastasis, arresting cancer cells in an indefinite dormant state and preventing tumor cell colonization and thus the establishment of aggressive metastatic disease.See related article by Shinde et al., p. 1831.

Multiplex fluorescent immunohistochemistry quantitatively analyses microvascular density (MVD) and the roles of TGF-β signalling in orchestrating angiogenesis in colorectal cancer

Background

Advances in multiplex fluorescent immunohistochemistry (mfIHC) techniques and digital pathology platforms allow the quantification of multiple proteins in the same tissue section and produce continuous data. Previously, we used mfIHC to establish the expressed profiles of proteins involved in TGF-β signalling in colorectal cancer (CRC).

Methods

We used mfIHC to show microvascular density (MVD) by staining CD31 in the tissues from CRC patients. We further investigated the relationship between MVD and TGF-β signalling.

Results

We found that the levels of MVD were significantly higher in cancer tissues than in paired normal tissues. Prognostic analysis revealed that the survival time for CRC patients with high levels of MVD was significantly shorter than that for those with low levels of MVD. Systematic analysis of the levels of MVD and TGF-β signalling proteins revealed that TGF-β signalling showed contradictory roles in sustained tumour angiogenesis. In CRC cells, the expression of VEGFA was increased by low concentrations of TGFB1 but decreased by high concentrations of TGFB1. Vessel-forming assays demonstrated that low-dose TGFB1 stimulated but high-dose TGFB1 inhibited HUVECs to form vessel tubes.

Conclusions

Our analysis based on mfIHC staining in CRC tissues supports the concept that TGF-β signalling either promotes or inhibits tumour angiogenesis.

Epithelial to Mesenchymal Transition and Cell Biology of Molecular Regulation in Endometrial Carcinogenesis

Endometrial carcinogenesis is involved in several signaling pathways and it comprises multiple steps. The four major signaling pathways-PI3K/AKT, Ras/Raf/MEK/ERK, WNT/β-catenin, and vascular endothelial growth factor (VEGF)-are involved in tumor cell metabolism, growth, proliferation, survival, and angiogenesis. The genetic mutation and germline mitochondrial DNA mutations also impair cell proliferation, anti-apoptosis signaling, and epithelial⁻mesenchymal transition by several transcription factors, leading to endometrial carcinogenesis and distant metastasis. The PI3K/AKT pathway activates the ransforming growth factor beta (TGF-β)-mediated endothelial-to-mesenchymal transition (EMT) and it interacts with downstream signals to upregulate EMT-associated factors. Estrogen and progesterone signaling in EMT also play key roles in the prognosis of endometrial carcinogenesis. In this review article, we summarize the current clinical and basic research efforts regarding the detailed molecular regulation in endometrial carcinogenesis, especially in EMT, to provide novel targets for further anti-carcinogenesis treatment.

From Desert to Medicine: A Review of Camel Genomics and Therapeutic Products

Camels have an important role in the lives of human beings, especially in arid regions, due to their multipurpose role and unique ability to adapt to harsh conditions. In spite of its enormous economic, cultural, and biological importance, the camel genome has not been widely studied. The size of camel genome is roughly 2.38 GB, containing over 20,000 genes. The unusual genetic makeup of the camel is the main reason behind its ability to survive under extreme environmental conditions. The camel genome harbors several unique variations which are being investigated for the treatment of several disorders. Various natural products from camels have also been tested and prescribed as adjunct therapy to control the progression of ailments. Interestingly, the camel employs unique immunological and molecular mechanisms against pathogenic agents and pathological conditions. Here, we broadly review camel classification, distribution and breed as well as recent progress in the determination of the camel genome, its size, genetic distribution, response to various physiological conditions, immunogenetics and the medicinal potential of camel gene products.

Cancer upregulated gene (CUG)2 elevates YAP1 expression, leading to enhancement of epithelial-mesenchymal transition in human lung cancer cells

Although our previous studies have showed that a novel oncogene, cancer upregulated gene (CUG)2 induced epithelial-mesenchymal transition (EMT), the detailed molecular mechanism remains unknown. Because several lines of evidence documented that Yes-Associated Protein (YAP)1 is closely associated with cancer stem cell (CSC)-like phenotypes including EMT, stemness, and drug resistance, we wondered if YAP1 is involved in CUG2-induced EMT. We herein found that the overexpression of CUG2 increased YAP1 expression at the transcriptional as well as protein levels. Chromatin immunoprecipitation assay revealed that the elevated YAP1 transcripts are attributed to c-Jun and AP2 bindings to the YAP1 promoter. Akt and MAPK kinases including ERK, JNK, and p38 MAPK enhanced the level of YAP1 protein. In spite of a close relationship between β-catenin and YAP1, not β-catenin but NEK2 played the role in increasing YAP1 expression. Silencing YAP1 inhibited CUG2-induced cell migration and invasion. N-cadherin and vimentin expressions were decreased during YAP1 knockdown. The suppression of YAP1 diminished TGF-β transcriptional activity and expression as well as phosphorylation level of Smad2 and Twist protein. Conversely, LY2109761 or Smad2 siRNA treatment reduced YAP1 protein levels, indicating a close interplay between YAP1 and TGF-β signaling. Taken together, we suggest that CUG2 induces up-regulation of YAP1 expression, leading to enhancing CUG2-induced EMT via a close crosstalk between YAP1 and TGF-β signaling.

Evaluation of the cytotoxic effect of Ly2109761 on HeLa cells using the xCELLigence RTCA system

In the present study, the in vitro cytotoxic effect of a novel transforming growth factor-β receptor inhibitor, LY2109761, was investigated in the human cervix carcinoma HeLa cell lines. For the purpose of the present study, cell index values obtained using the xCELLigence Real-Time Cell Analysis DP instrument, and mitotic, labelling and apoptotic index analysis were used. The results of the present study indicated that LY2109761 affected the cytoskeleton of HeLa cells, decreased the mitotic and labelling index values of the HeLa cell line, and increased the apoptotic index values. Significant differences were observed between the control group which was not treated with LY2109761 and the experimental groups, which were treated with LY2109761 (P<0.01). The results of the present study suggest that LY2109761 may serve as a promising treatment option for cervix carcinoma.

Towards the contribution of the p38MAPK pathway to the dual role of TGFβ in cancer: A boolean model approach

The transforming growth factor-beta (TGF-β) pathway is involved in the regulation of cell growth and differentiation. In normal cells or in the early stages of cancer, this pathway can control proliferation stimuli by inducing cell cycle arrest or apoptosis (through the MAP-kinase protein p38MAPK), while in late stages it seems to act as a tumor promoter. This feature is known as the TGF-β dual role in cancer and it is not completely explained. This seems to arise through the accumulation of mutations in cancer development that affect the normal function of these pathways. In this work we propose a Boolean model of the crosstalk between the TGF-β, p38 MAPK and cell cycle checkpoint pathways which qualitatively describes this dual behavior. The model shows that for the wild type case, TGF-β acts as tumor supressor by inducing cell cycle arrest or apoptosis, as expected. However, the loss of function (LoF) of its two signaling proteins: SMAD2 and SMAD3 has immortalization effects due to the activation of the PI3K/AKT pathway that contributes to inhibit apoptosis. In silico mutations of the model elements were compared with cell phenotypes in experiments presenting agreement. In addition, we performed a series of double gene perturbations (that simulate random deleterious mutations) to determine the main regulators of the network. The results suggest that SMAD2/3 and p38MAPK are key players in processing the network input. In addition, when the LoF of SMAD2/3 is combined with the LoF of p38MAPK and p53, cell cycle arrest is completely abrogated. In conclusion, the model allows to visualize, through in silico mutations, the dual role of TGF-β: for the wild-type case TGF-β is able to block proliferation, however deleterious mutations can impair cell cycle arrest promoting cellular proliferation.

Interleukin-27 Inhibits Trophoblast Cell Invasion and Migration by Affecting the Epithelial-Mesenchymal Transition in Preeclampsia

Preeclampsia (PE) is a pregnancy-specific disorder representing a major cause of maternal and perinatal morbidity and mortality. Invasive and migratory phenotypes are acquired by trophoblasts through the process of epithelial-mesenchymal transition (EMT). Studies have shown that trophoblast EMT events are dysregulated in PE and play an important role in its development. Dysregulation of interleukin (IL)-27 and IL-27R (T-cell cytokine receptor (TCCR)/WSX -1) is relevant to PE. In this study, our results demonstrated that IL-27 did not significantly affect the proliferation and apoptosis of HTR -8/SVneo trophoblast cells, while it did significantly inhibit trophoblast invasion and migration. The expression of EMT-related proteins in HTR-8/SVneo cells and extravillous explants was detected after treatment with IL-27. Expression of epithelial markers was increased, and mesenchymal marker expression was reduced. Furthermore, we found that IL-27 could induce significant phosphorylation of Signal Transducer and Activator of Transcription 1 (STAT1) and Signal Transducer and Activator of Transcription 3 (STAT3) in a time-dependent manner in HTR-8/SVneo cells. Selective inhibitors of STAT1 (STAT1 siRNA) and STAT3 (STAT3 siRNA) were used to determine whether both STAT1 and STAT3 are required for IL-27-mediated inhibition of EMT. STAT1 inhibition in IL-27-treated cells attenuated the IL-27 effect, while the inhibition of STAT3 activation had no effect on the development of the epithelial phenotype. These results demonstrate that IL-27 may inhibit trophoblast cell migration and invasion by affecting the EMT process through an STAT1-dominant pathway in PE.

Bone morphogenetic protein and activin membrane-bound inhibitor suppress bone cancer progression in MG63 and SAOS cells via regulation of the TGF-β-induced EMT signaling pathway

Bone cancer is one of the most common tumor types that occurs in bones and their affiliated tissues. The prognosis remains poor due to the limited number of effective therapeutic targets. Downregulation of bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) has been observed in human cancer cells and BAMBI reconstitution can inhibit growth and metastasis of human cancer cells. In the present study, a potential mechanism mediated by BAMBI in osteosarcoma cells was investigated. The data demonstrated that BAMBI reconstitution suppressed the cell growth, migration and invasion of the osteosarcoma cell lines SAOS2 and MG63. Alterations to the epithelial-to-mesenchymal transition (EMT) marker expression were observed in BAMBI-treated osteosarcoma SAOS2 and MG63 cells. The apoptosis rate of SAOS2 and MG63 cells induced by cisplatin were increased in BAMBI-treated osteosarcoma SAOS2 and MG63 cells via downregulation of the anti-apoptosis genes P16, P21 and B-cell lymphoma 2. The potential mechanism investigated indicated that BAMBI administration downregulated the transforming growth factor-β (TGF-β) signaling pathway, whilst knockdown of BAMBI upregulated the TGF-β signaling pathway in SAOS2 and MG63 cells. Reconstitution of BAMBI in SAOS2 and MG63 cells resulted in a notable reduction of TGF-β-induced EMT, cell growth, migration and invasion in vitro. In conclusion, the results demonstrated that BAMBI reconstitution inhibited growth and invasiveness of osteosarcoma, as well as promoted the apoptotic sensibility, which indicated that the TGF-β-induced EMT signaling pathway may be regarded as a potential target for osteosarcoma therapy.

LINK-A lncRNA promotes migration and invasion of ovarian carcinoma cells by activating TGF-β pathway

Introduction: LINK-A lncRNA is a well-characterized oncogenic lncRNA only in triple negative breast cancer. Our study was carried out to investigate the possible involvement of LINK-A lncRNA in ovarian carcinoma. Methods: Expression of LINK-A in ovarian biopsies and plasma of both ovarian carcinoma patients and healthy females was detected by qRT-PCR. Plasma TGF-β1 was detected by ELISA. Correlation between plasma LINK-A and TGF-β1 was analyzed by Pearson correlation analysis. Correlation between plasma LINK-A and patients' clinicopathological data was analyzed by Chi-square test. LINK-A overexpression vector was transfected into cells of human ovarian carcinoma cell lines. Cell migration and invasion were detected by Transwell migration and invasion assay. TGF-β1 expression was detected by Western blot. Results: We found that LINK-A and TGF-β1 were up-regulated in ovarian carcinoma patients than in healthy controls. Plasma levels of LINK-A were positively correlated with plasma TGF-β1 in ovarian carcinoma patients but not in healthy controls. Plasma levels of LINK-A were correlated with distant tumor metastasis but not tumor size. LINK-A overexpression led to up-regulated TGF-β1 in ovarian carcinoma cells and promoted cell migration and invasion. In contrast, TGF-β1 treatment showed no effects on LINK-A expression but attenuated the effects of LINK-A overexpression on cell migration and invasion. Conclusions: We conclude that LINK-A lncRNA may promote migration and invasion of ovarian carcinoma cells by activating TGF-β pathway.

TGF-β induced epithelial-mesenchymal transition in an advanced cervical tumor model by 3D printing

An advanced in vitro cervical tumor model was established by 3D printing to study the epithelial-to-mesenchymal transition (EMT), which is a very important stage of dissemination of carcinoma leading to metastatic tumors. A HeLa/hydrogel grid construct composed of gelatin, alginate, Matrigel and HeLa cells was fabricated by forced extrusion in a layer-by-layer fashion. HeLa cells rapidly proliferated, formed spheroids and presented tumorigenic characteristic in the 3D-printed structure. With the supplement of TGF-β, aggregated HeLa cells started to disintegrate, and some of them changed into fibroblast-like spindle morphology, which indicated that EMT was induced. The down-regulation of epithelial marker E-cadherin, and up-regulation of mesenchymal markers such as snail, vimentin and N-cadherin were all observed in the 3D-printed model, and performed differently in 3D and 2D models. The TGF-β induced EMT was inhibited by the treatment of disulfiram and EMT pathway inhibitor C19 in a dose dependent manner, showing great potential for future studies of a therapeutic program towards cervical tumor metastasis.

Rab23 Promotes Hepatocellular Carcinoma Cell Migration Via Rac1/TGF-β Signaling

Rab23 is a member of Ras-related small GTPase family, which plays a critical role in the progression of wide range of tumors. However, its biological function in hepatocellular carcinoma still remains unclear. Here, we investigated the effects of Rab23 on proliferation and migration in hepatocellular carcinoma cell and its potential mechanisms. We found over-expression of Rab23 promoted the Hep3B hepatocellular carcinoma cell migration, which could be reversed by Rab23 silencing. Rab23 induced Rac1 activation and followed progression of epithelial-mesenchymal transition (EMT) along with upregulation of N-cadherin, snail as well as vimentin and downregulation of E-cadherin via upregulating Transforming Growth Factor-β (TGF-β). Silencing Rac1 significantly attenuated Rab23-induced HepG2 migration and TGF-β. Moreover, knockdown of TGF-β effectively attenuated Rab23-induced EMT. Taken together, we demonstrated a mechanistic cascade of Rab23 enhangcing Rac1 activation and subsequent TGF-β expression, leading to hepatocellular carcinoma cell migration.

lncRA ANCR Inhibits Non-Small Cell Lung Cancer Cell Migration and Invasion by Inactivating TGF-β Pathway

Background

lncRNA ANCR is proved to be a tumor suppressor gene only in colorectal cancer and breast cancer. Our study aimed to explore the possible involvement of ACNR in non-small cell lung cancer (NSCLC).

Material/Methods

In this study, we first detected the expression of ACNR in lung biopsies and plasma of both NSCLC patients and healthy controls. The diagnostic value of ANCR for NSCLC was analyzed by ROC curve analysis. Follow-up data of NSCLC patients was analyzed and the prognostic value of ANCR was analyzed by survival curve analysis. ANCR expression vector was transfected into cells of human NSCLC cell lines, and the effects on cell migration and invasion were explored by Transwell migration and invasion assays, respectively. TGF-β1 expression after ANCR overexpression was detected by Western blot analysis.

Results

ANCR was significantly downregulated in NSCLC patients compared with healthy controls in lung biopsies and plasma. Downregulated expression of ANCR distinguishes NSCLC patients from healthy controls and low NSCLC expression level indicates shorter postoperative survival time of NSCLC patients. ANCR overexpression inhibited NSCLC cell migration and invasion and downregulated TGF-β1 expression, while TGF-β1 treatment showed no significant effects on ANCR expression but promoted NSCLC cell migration and invasion. In addition, TGF-β1 treatment also attenuated the inhibitory effects of ANCR overexpression on NSCLC cell migration and invasion.

Conclusions

ANCR can inhibit NSCLC cell migration and invasion by downregulating TGF-β1 expression.

Transforming growth factor-β1 gene promoter -509C/T polymorphism in association with expression affects colorectal cancer development and depends on gender

It is widely known that sporadic colorectal cancer (CRC) is age-related diseases with higher incidence rate among men. Transforming growth factor-β1 (TGF-β1) is a major immune regulatory cytokine with a great impact and dual role in gastrointestinal carcinogenesis. In this context, the aim of the study was to explore the role of circulating TGF-β1 and the -509C/T functional promoter polymorphism (rs1800469) within the TGF-β1 gene (TGFB1) in the susceptibility, progression, and prognosis of CRC among Bulgarian male and female patients. Patients with sporadic CRC and healthy controls were genotyped by polymerase-chain reaction–restriction fragment length polymorphism. Serum TGF-β1 levels before and after curative surgery were determined by ELISA. Total RNA was extracted from paired tumor, normal mucosa and distant metastasis samples and was used for quantitative detection of TGFB1 mRNA by TaqMan qPCR.We observed that TGF-β1 serum levels depend on the -509C/T genotype in combination with gender. TGF-β1 serum levels in CRC patients were decreased compared to controls, but statistical significance was reached only for men. In the stratified analysis by gender and genotype, a significant association was found for the CC genotype. Overall, our results indicate that the -509C allele increased the cancer risk, particularly for advanced stages (OR = 1.477; p = 0.029). The results from the relative mRNA quantification showed a significant upregulation of TGFB1 in distant metastases compared to primary tumor tissues and higher TGFB1 mRNA levels in men (RQ = 4.959; p = 0.022). In conclusion, we present data that diminished circulating TGF-β1 due to the CC genotype could be a possible risk factor for tumor susceptibility and progression. This association is more pronounced in males than in females. Colorectal cancer tissue expression of TGFB1 gene mRNA correlates with tumor progression and metastasis.

LY2109761 reduces TGF-β1-induced collagen production and contraction in hypertrophic scar fibroblasts

Hypertrophic scars (HS) are fibro-hyperproliferative dermal lesions with effusive continuous accumulation of extracellular matrix components, particularly collagen. They usually occur after dermal injury in genetically susceptible individuals and cause both physical and psychological distress for the affected individuals. Transforming growth factor-β1 (TGF-β1) is known to mediate wound healing process by regulating cell differentiation, collagen production and extracellular matrix degradation. The sustained high expression of TGF-β1 is believed to result in the formation of hypertrophic scars. Inhibition of TGF-β1 signaling pathway may represent one of effective strategies for limiting excessive scarring. LY2109761, an orally active TβRI/II kinase dual inhibitor, has been previously reported that it had inhibitory effects on carcinomas and attenuates Radiation-induced pulmonary murine fibrosis. Our results revealed that LY2109761 reduced TGF-β1-induced collagen production and α-smooth muscle actin (α-SMA) expression, and attenuated TGF-β1-induced cell contraction in hypertrophic scar fibroblasts. The data from this study provide evidence supporting the potential use of LY2109761 as a novel treatment for hypertrophic scars.

Role of Homeodomain-Interacting Protein Kinase 2 in the Pathogenesis of Tissue Fibrosis in Keloid-Derived Keratinocytes

Epithelial-mesenchymal transition (EMT) plays a critical role in fibrotic keloid formation, which is characterized by excessive collagen and extracellular matrix synthesis and deposition. Growing evidence suggests that the serine/threonine kinase homeodomain-interacting protein kinase 2 (HIPK2) acts upstream of several major fibrosis signaling pathways; however, the role of HIPK2 in the keloid fibrogenesis remains unknown. In the current study, we investigated the roles of HIPK2 in the pathogenesis of keloids. Primary normal skin and keloid keratinocytes were cultured and pretreated with transforming growth factor (TGF)-β1. Next, keratinocytes were transfected with scrambled small interfering RNA (siRNA) and anti-HIPK2 siRNA. The TGF-β1-associated HIPK2 alterations were investigated by quantitative real-time polymerase chain reaction. Protein levels were analyzed by western blotting. The HIPK2 was markedly increased in the keloid-derived keratinocytes compared with normal skin keratinocytes. In addition, HIPK2 induced the expression of EMT markers in normal skin keratinocytes by TGF-β1-SMAD family member 3 (SMAD3). The effect of TGF-β1-related EMT markers and SMAD3 phosphorylation in response to added TGF-β1 was significantly abrogated when the cells were transfected with HIPK2 siRNA. We conclude that HIPK2 is a crucial factor in the pathogenesis of keloids, suggesting that HIPK2 might be a novel potential drug target for antikeloid therapy.

CRISPR-Mediated Reactivation of DKK3 Expression Attenuates TGF-β Signaling in Prostate Cancer

The DKK3 gene encodes a secreted protein, Dkk-3, that inhibits prostate tumor growth and metastasis. DKK3 is downregulated by promoter methylation in many types of cancer, including prostate cancer. Gene silencing studies have shown that Dkk-3 maintains normal prostate epithelial cell homeostasis by limiting TGF-β/Smad signaling. While ectopic expression of Dkk-3 leads to prostate cancer cell apoptosis, it is unclear if Dkk-3 has a physiological role in cancer cells. Here, we show that treatment of PC3 prostate cancer cells with the DNA methyltransferase (DNMT) inhibitor decitabine demethylates the DKK3 promoter, induces DKK3 expression, and inhibits TGF-β/Smad-dependent transcriptional activity. Direct induction of DKK3 expression using CRISPR-dCas9-VPR also inhibited TGF-β/Smad-dependent transcription and attenuated PC3 cell migration and proliferation. These effects were not observed in C4-2B cells, which do not respond to TGF-β. TGF-β signals can regulate gene expression directly via SMAD proteins and indirectly by increasing DNMT expression, leading to promoter methylation. Analysis of genes downregulated by promoter methylation and predicted to be regulated by TGF-β found that DKK3 induction increased expression of PTGS2, which encodes cyclooxygenase-2. Together, these observations provide support for using CRISPR-mediated induction of DKK3 as a potential therapeutic approach for prostate cancer and highlight complexities in Dkk-3 regulation of TGF-β signaling.

Integrin αvβ6: Structure, function and role in health and disease

Integrins are cell surface receptors that traditionally mediate cell-to-extracellular matrix and cell-to-cell adhesion. They can, however, also bind a large repertoire of other molecules. Integrin αvβ6 is exclusively expressed in epithelial cells where it can, for example, serve as a fibronectin receptor. However, its hallmark function is to activate transforming growth factor-β1 (TGF-β1) to modulate innate immune surveillance in lungs and skin and along the gastrointestinal tract, and to maintain epithelial stem cell quiescence. The loss of αvβ6 integrin function in mice and humans leads to an altered immune response in lungs and skin, amelogenesis imperfecta, periodontal disease and, in some cases, alopecia. Elevated αvβ6 integrin expression and aberrant TGF-β1 activation and function are associated with organ fibrosis and cancer. Therefore, αvβ6 integrin serves as an attractive target for cancer imaging and for fibrosis and cancer therapy.

Next generation of immune checkpoint therapy in cancer: new developments and challenges

Immune checkpoints consist of inhibitory and stimulatory pathways that maintain self-tolerance and assist with immune response. In cancer, immune checkpoint pathways are often activated to inhibit the nascent anti-tumor immune response. Immune checkpoint therapies act by blocking or stimulating these pathways and enhance the body's immunological activity against tumors. Cytotoxic T lymphocyte-associated molecule-4 (CTLA-4), programmed cell death receptor-1 (PD-1), and programmed cell death ligand-1(PD-L1) are the most widely studied and recognized inhibitory checkpoint pathways. Drugs blocking these pathways are currently utilized for a wide variety of malignancies and have demonstrated durable clinical activities in a subset of cancer patients. This approach is rapidly extending beyond CTLA-4 and PD-1/PD-L1. New inhibitory pathways are under investigation, and drugs blocking LAG-3, TIM-3, TIGIT, VISTA, or B7/H3 are being investigated. Furthermore, agonists of stimulatory checkpoint pathways such as OX40, ICOS, GITR, 4-1BB, CD40, or molecules targeting tumor microenvironment components like IDO or TLR are under investigation. In this article, we have provided a comprehensive review of immune checkpoint pathways involved in cancer immunotherapy, and discuss their mechanisms and the therapeutic interventions currently under investigation in phase I/II clinical trials. We also reviewed the limitations, toxicities, and challenges and outline the possible future research directions.

Cancer upregulated gene 2 induces epithelial-mesenchymal transition of human lung cancer cells via TGF-β signaling

Cancer upregulated gene 2 (CUG2) enhances cell migration and invasion, but the underlying mechanism has not been revealed. Herein, CUG2 decreased the expression of E-cadherin and increased the expression of N-cadherin and vimentin, characteristics of the epithelial-mesenchymal transition (EMT). A CUG2 deletion mutant, lacking interaction with nucleophosmin 1 (NPM1), or suppression of NPM1 reduced wound healing and cell invasion, indicating that CUG2-mediated EMT requires NPM1. CUG2 enhanced activation of Smad2/3 and expression of Snail and Twist, while the CUG2 silence decreased these TGF-β signaling pathways, leading to suppression of EMT. NPM silence also inhibited the CUG2-induced TGF-β signaling. These results suggest that TGF-β signaling is involved in CUG2-induced EMT. Treatment with EW-7197, a novel inhibitor of TGF-β signaling, diminished CUG2-mediated EMT and inhibition of Akt, ERK, JNK, and p38 MAPK, non-canonical TGF-β signaling molecules, also decreased expression of Smad2/3, Snail and Twist, leading to inhibition of EMT. The results confirm that TGF-β signaling is essential for CUG2-mediated EMT. Interestingly, TGF-β enhanced CUG2 expression. We further found that both CUG2-induced TGF-β production and TGF-β-induced CUG2 up-regulation required a physical interaction between Sp1 and Smad2/3 in the CUG2 and TGF-β promoter, as demonstrated by a promoter reporter assay, immunoprecipitation, and ChIP assay. These results indicated close crosstalk between CUG2 and TGF-β. Conversely, suppression of CUG2 or NPM1 did not completely inhibit TGF-β-induced EMT, indicating that the effect of TGF-β on EMT is dominant over the effect of CUG2 on EMT. Collectively, our findings suggest that CUG2 induces the EMT via TGF-β signaling.

FGFR signaling maintains a drug persistent cell population following epithelial-mesenchymal transition

An emerging characteristic of drug resistance in cancer is the induction of epithelial-mesenchymal transition (EMT). However, the mechanisms of EMT-mediated drug resistance remain poorly defined. Therefore, we conducted long-term treatments of human epidermal growth factor receptor-2 (Her2)-transformed breast cancer cells with either the EGFR/Her2 kinase inhibitor, Lapatinib or TGF-β, a known physiological inducer of EMT. Both of these treatment regimes resulted in robust EMT phenotypes, but upon withdrawal a subpopulation of TGF-β induced cells readily underwent mesenchymal-epithelial transition, where as Lapatinib-induced cells failed to reestablish an epithelial population. The mesenchymal population that remained following TGF-β stimulation and withdrawal was quickly selected for during subsequent Lapatinib treatment, manifesting in inherent drug resistance. The Nanostring cancer progression gene panel revealed a dramatic upregulation of fibroblast growth factor receptor 1 (FGFR1) and its cognate ligand FGF2 in both acquired and inherent resistance. Mechanistically, FGF:Erk1/2 signaling functions to stabilize the EMT transcription factor Twist and thus maintain the mesenchymal and drug resistant phenotype. Finally, Lapatinib resistant cells could be readily eliminated using recently characterized covalent inhibitors of FGFR. Overall our data demonstrate that next-generation targeting of FGFR can be used in combination with Her2-targeted therapies to overcome resistance in this breast cancer subtype.

The role of tumor microenvironment in therapeutic resistance

Cancer cells undergo unlimited progression and survival owing to activation of oncogenes. However, support of the tumor microenvironment is essential to the formation of clinically relevant tumors. Recent evidence indicates that the tumor microenvironment is a critical regulator of immune escape, progression, and distant metastasis of cancer. Moreover, the tumor microenvironment is known to be involved in acquired resistance of tumors to various therapies. Despite significant advances in chemotherapy and radiotherapy, occurrence of therapeutic resistance leads to reduced efficacy. This review highlights myeloid cells, cancer-associated fibroblasts, and mesenchymal stem cells consisting of the tumor microenvironment, as well as the relevant signaling pathways that eventually render cancer cells to be therapeutically resistant.

Genetic status of KRAS influences Transforming Growth Factor-beta (TGF-β) signaling: An insight into Neuropilin-1 (NRP1) mediated tumorigenesis

Oncogenic RAS and deregulated transforming growth factor-beta (TGF)-β signaling have been implicated in several cancers. So far, attempts to target either one of them therapeutically have been futile as both of them are involved in multiple fundamental cellular processes and the normal forms are expressed by almost all cells. Hence, their inhibition would disrupt several physiological processes. Besides, their downregulation stimulates the tumor cells to develop adaptive mechanisms and would most likely be ineffective as therapeutic targets. Furthermore, growing literature suggests that both of these signaling pathways converge to enhance tumor development. Therefore, a lot of interest has been generated to explore the areas where these pathways interface that might identify new molecules that could potentially serve as novel therapeutic targets. In this review, we focus on such convergent signaling and cross-interaction that is mediated by neuropilin-1 (NRP1), a receptor that can interact with multiple growth factors including TGF-β for promoting tumorigenesis process.

GP73 promotes invasion and metastasis of bladder cancer by regulating the epithelial-mesenchymal transition through the TGF-β1/Smad2 signalling pathway

This study investigated the effects of Golgi membrane protein 73 (GP73) on the epithelial-mesenchymal transition (EMT) and on bladder cancer cell invasion and metastasis through the TGF-β1/Smad2 signalling pathway. Paired bladder cancer and adjacent tissue samples (102) and normal bladder tissue samples (106) were obtained. Bladder cancer cell lines (T24, 5637, RT4, 253J and J82) were selected and assigned to blank, negative control (NC), TGF-β, thrombospondin-1 (TSP-1), TGF-β1+ TSP-1, GP73-siRNA-1, GP73-siRNA-2, GP73-siRNA-1+ TSP-1, GP73-siRNA-1+ pcDNA-GP73, WT1-siRNA and WT1-siRNA + GP73-siRNA-1 groups. Expressions of GP73, TGF-β1, Smad2, p-Smad2, E-cadherin and vimentin were detected using RT-qPCR and Western blotting. Cell proliferation, migration and invasion were determined using MTT assay, scratch testing and Transwell assay, respectively. Compared with the blank and NC groups, levels of GP73, TGF-β1, Smad2, p-Smad2, N-cadherin and vimentin decreased, and levels of WT1 and E-cadherin increased in the GP73-siRNA-1 and GP73-siRNA-2 groups, while the opposite results were observed in the WT1 siRNA, TGF-β, TSP-1 and TGF-β + TSP-1 groups. Cell proliferation, migration and invasion notably decreased in the GP73-siRNA-1 and GP73-siRNA-2 groups in comparison with the blank and NC groups, while in the WT1 siRNA, TGF-β, TSP-1 and TGF-β + TSP-1 groups, cell migration, invasion and proliferation showed the reduction after the EMT. These results suggest that GP73 promotes bladder cancer invasion and metastasis by inducing the EMT through down-regulating WT1 levels and activating the TGF-β1/Smad2 signalling pathway.

Long non-coding RNA XIST promotes TGF-β-induced epithelial-mesenchymal transition by regulating miR-367/141-ZEB2 axis in non-small-cell lung cancer

Growing evidence shows that lncRNA XIST functions as an oncogene accelerating tumor progression. Transforming growth factor β (TGF-β)-induced epithelial-mesenchymal transition (EMT) plays a key role in tumor metastasis. However, it is still unclear whether lncRNA XIST is implicated in TGF-β-induced EMT and influences cell invasion and metastasis in non-small-cell lung cancer (NSCLC). Here, we observed increased expression of lncRNA XIST and ZEB2 mRNA in metastatic NSCLC tissues. Knockdown of lncRNA XIST inhibited ZEB2 expression, and repressed TGF-β-induced EMT and NSCLC cell migration and invasion. Being in consistent with the in vitro findings, the in vivo experiment of metastasis showed that knockdown of lncRNA XIST inhibited pulmonary metastasis of NSCLC cells in mice. In addition, knockdown of ZEB2 expression can inhibit TGF-β-induced EMT and NSCLC cell migration and invasion. Mechanistically, lncRNA XIST and ZEB2 were targets of miR-367 and miR-141. Furthermore, both miR-367 and miR-141 expression can be upregulated by knockdown of lncRNA XIST. Taken together, our study reveals that lncRNA XIST can promote TGF-β-induced EMT and cell invasion and metastasis by regulating miR-367/miR-141-ZEB2 axis in NSCLC.

Anti-cancer Effects of HNHA and Lenvatinib by the Suppression of EMT-Mediated Drug Resistance in Cancer Stem Cells

Anaplastic thyroid cancer (ATC) constitutes less than 2% of total thyroid cancers but accounts for 20–40% of thyroid cancer-related deaths. Cancer stem cell drug resistance represents a primary factor hindering treatment. This study aimed to develop targeted agents against thyroid malignancy, focusing on individual and synergistic effects of HNHA (histone deacetylase), lenvatinib (FGFR), and sorafenib (tyrosine kinase) inhibitors. Patients with biochemically and histologically proven papillary thyroid cancer (PTC) and ATC were included. Cell samples were obtained from patients at the Thyroid Cancer Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea. PTC and ATC cells were treated with lenvatinib or sorafenib, alone or in combination with HNHA. Tumor-bearing mice (10/group) were administered 10 mg/kg lenvatinib (p.o.) or 40 mg/kg sorafenib (p.o.), alone or in combination with 25 mg/kg HNHA (i.p.) once every three days. Gene expression in patient-derived PTC and ATC cells was compared using a microarray approach. Cellular apoptosis and proliferation were examined by immunohistochemistry and MTT assays. Tumor volume and cell properties were examined in the mouse xenograft model. HNHA-lenvatinib combined treatment induced markers of cell cycle arrest and apoptosis and suppressed anti-apoptosis markers, epithelial-mesenchymal transition (EMT), and the FGFR signaling pathway. Combined treatment induced significant tumor shrinkage in the xenograft model. HNHA-lenvatinib combination treatment thus blocked the FGFR signaling pathway, which is important for EMT. Treatment with HNHA-lenvatinib combination was more effective than either agent alone or sorafenib-HNHA combination. These findings have implications for ATC treatment by preventing drug resistance in cancer stem cells.

CD109 released from human bone marrow mesenchymal stem cells attenuates TGF-β-induced epithelial to mesenchymal transition and stemness of squamous cell carcinoma

Although there is increasing evidence that human bone marrow mesenchymal stem cells (hBM-MSCs) play an important role in cancer progression, the underlying mechanisms are poorly understood. Transforming growth factor β (TGF-β) is an important pro-metastatic cytokine. We have previously shown that CD109, a glycosylphosphatidylinositol-anchored protein, is a TGF-β co-receptor and a strong inhibitor of TGF-β signalling. Moreover, CD109 can be released from the cell surface. In the current study, we examined whether hBM-MSCs regulate the malignant properties of squamous cell carcinoma cells, and whether CD109 plays a role in mediating the effect of hBM-MSCs on cancer cells. Here we show that hBM-MSC-conditioned medium decreases proliferation and induces apoptosis in human squamous carcinoma cell lines, A431 and FaDu. Importantly, hBM-MSC-conditioned medium markedly suppresses markers of epithelial-to-mesenchymal transition and stemness, and concomitantly decreases cell migration, invasion, and spheroid formation in A431 and FaDu cells. In addition, knockdown of CD109 in hBM-MSCs abrogates the anti-malignant activity of hBM-MSC-conditioned medium on A431 and FaDu cells. Furthermore, overexpression of CD109 in A431 cells decreases their malignant traits. Together, our findings suggest that hBM-MSCs inhibit the malignant traits of squamous cell carcinoma cells by a paracrine effect via released factors and that CD109 released from hBM-MSCs, at least partially, mediates these effects.

New therapeutic directions for advanced pancreatic cancer: cell cycle inhibitors, stromal modifiers and conjugated therapies

INTRODUCTION

Pancreatic adenocarcinoma is a devastating malignancy with an extremely poor prognosis. These tumors progress rapidly and somewhat silently with few specific symptoms and are relatively resistant to chemotherapeutic agents. Many agents, including cell cycle inhibitors, are under development for the treatment of this cancer for which there are disappointingly few treatment options. Areas covered: Here we outline the existing approved treatments for advanced pancreatic disease and discuss a range of novel therapies currently under development including cell cycle inhibitors, stromal modifiers and conjugated therapies. We also describe the current state of the pancreatic cancer therapeutics market both past and future. Expert opinion: Despite the recent explosion of novel therapies with an array of unique targets, the core treatment of pancreatic cancer still with traditional cytotoxic agents with a few exceptions. However, as these novel treatments move through the pipeline, we are hopeful that there will soon be a number of effective options for patients with advanced pancreatic cancer.

ITGA1 is a pre-malignant biomarker that promotes therapy resistance and metastatic potential in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has single-digit 5-year survival rates at <7%. There is a dire need to improve pre-malignant detection methods and identify new therapeutic targets for abrogating PDAC progression. To this end, we mined our previously published pseudopodium-enriched (PDE) protein/phosphoprotein datasets to identify novel PDAC-specific biomarkers and/or therapeutic targets. We discovered that integrin alpha 1 (ITGA1) is frequently upregulated in pancreatic cancers and associated precursor lesions. Expression of ITGA1-specific collagens within the pancreatic cancer microenvironment significantly correlates with indicators of poor patient prognosis, and depleting ITGA1 from PDAC cells revealed that it is required for collagen-induced tumorigenic potential. Notably, collagen/ITGA1 signaling promotes the survival of ALDH1-positive stem-like cells and cooperates with TGFβ to drive gemcitabine resistance. Finally, we report that ITGA1 is required for TGFβ/collagen-induced EMT and metastasis. Our data suggest that ITGA1 is a new diagnostic biomarker and target that can be leveraged to improve patient outcomes.

TGF-β Stimulation of EMT Programs Elicits Non-genomic ER-α Activity and Anti-estrogen Resistance in Breast Cancer Cells

AIM

Estrogen receptor-α (ER-α) activation drives the progression of luminal breast cancers. Signaling by transforming growth factor-β (TGF-β) typically opposes the actions of ER-α; it also induces epithelial-mesenchymal transition (EMT) programs that promote breast cancer dissemination, stemness, and chemoresistance. The impact of EMT programs on nongenomic ER-α signaling remains unknown and was studied herein.

METHODS

MCF-7 and BT474 cells were stimulated with TGF-β to induce EMT programs, at which point ER-α expression, localization, and nongenomic interactions with receptor tyrosine kinases and MAP kinases (MAPKs) were determined. Cell sensitivity to anti-estrogens both before and after traversing the EMT program was also investigated.

RESULTS

TGF-β stimulated MCF-7 and BT474 cells to acquire EMT phenotypes, which enhanced cytoplasmic accumulation of ER-α without altering its expression. Post-EMT cells exhibited (i) elevated expression of EGFR and IGF1R, which together with Src formed cytoplasmic complexes with ER-α; (ii) enhanced coupling of EGF, IGF-1 and estrogen to the activation of MAPKs; and (iii) reduced sensitivity to tamoxifen, an event reversed by administration of small molecule inhibitors against the receptors for TGF-β, EGF, and IGF-1, as well as those against MAPKs.

CONCLUSION

EMT stimulated by TGF-β promotes anti-estrogen resistance by activating EGFR-, IGF1R-, and MAPK-dependent nongenomic ER-α signaling.

Overexpression of CTHRC1 in human melanoma promotes tumorigenesis targeted by miRNA155

Most of human malignant melanoma is metastatic and invasive, which has poor therapeutic response and poor prognosis as well as high incidence worldwide. CTHRC1 was overexpressed in metastatic primary melanomas. The relationship between CTHRC1 and miRNA in affecting the melanoma has not been studied. This study was aimed to explore the function of CTHRC1 in human melanoma and finding its regulator miRNA. CTHRC1 and miR155 expression in cancer tissues and paracancer tissues was examined. The cell proliferation, cell cycle, cell migration and cell invasion was evaluated in M21 cell transfected with CTHRC1 siRNA or miR155. The mRNA expression of miR155 in cancer tissues was lower than that in paracancer tissues. The mRNA expression of CTHRC1 in the cancer tissues was higher than that in corresponding paracancer tissues. The mRNA expression of CTHRC1 in the M21 cells was decreased by treated with miR155 mimic. CTHRC1 promoted the cell proliferation, cell cycle process, cell migration and invasion capacity and prevented the cell from apoptosis. miR155 inhibited the cell proliferation, cell migration and cell invasion, arrested the cell cycle process at G1 phase and enhanced the cell apoptosis. The luciferases reporter assay showed that miR155 bound to the 3'-UTR of CTHRC1 and regulated the expression of CTHRC1, further influenced the functions of CTHRC1 in human melanoma development. The study contributed to unearthing a novel potential predictor and therapeutic targets of human melanoma. CTHRC1 was a potential independent predictor and therapeutic target for human melanoma.

SOX4: Joining the Master Regulators of Epithelial-to-Mesenchymal Transition?

The epithelial-to-mesenchymal transition (EMT) is an important developmental program exploited by cancer cells to gain mesenchymal features. Transcription factors globally regulating processes during EMT are often referred as 'master regulators' of EMT, and include members of the Snail and ZEB transcription factor families. The SRY-related HMG box (SOX) 4 transcription factor can promote tumorigenesis by endowing cells with migratory and invasive properties, stemness, and resistance to apoptosis, thereby regulating key aspects of the EMT program. We propose here that SOX4 should also be considered as a master regulator of EMT, and we review the molecular mechanisms underlying its function.

Transforming growth factor-β1 contributes to oxaliplatin resistance in colorectal cancer via epithelial to mesenchymal transition

Transforming growth factor-β1 (TGF-β1), secreted by main components of tumor microenvironment, is considered to be closely associated with cancer development and chemoresistance. The present study aimed to analyze the effects and mechanisms underlying TGF-β1-induced chemoresistance to oxaliplatin (LOH) in human colorectal cancer (CRC) cell lines. The cytotoxic effects of LOH subsequent to TGF-β1 treatment were assessed in three CRC cell lines by MTT assay. In addition, epithelial to mesenchymal transition (EMT), DNA damage and apoptosis assays were performed to evaluate the mechanisms of drug resistance in vitro. It was revealed that an exposure of CRC cells to TGF-β1 induced EMT. This was followed by a decrease in the levels of DNA damage and LOH-induced apoptotic cell death at certain TGF-β1 concentrations compared with untreated cells, which was responsible for LOH resistance. TGF-β1 leads to resistance to LOH in CRC cells, primarily through EMT. These data not only provide insight into the understanding of the chemoresistant mechanisms, but also may guide the clinical applications of reducing EMT to enhance the sensitivity to chemotherapy, by targeting TGF-β1.

CCT6A suppresses SMAD2 and promotes prometastatic TGF-β signaling

Paradoxically, during early tumor development in many cancer types, TGF-β acts as a tumor suppressor, whereas in the advanced stages of these cancers, increased TGF-β expression is linked to high metastasis and poor prognosis. These findings suggest that unidentified mechanisms may function to rewire TGF-β signaling toward its prometastatic role in cancer cells. Our current study using non-small-cell lung carcinoma (NSCLC) cell lines, animal models, and clinical specimens demonstrates that suppression of SMAD2, with SMAD3 function intact, switches TGF-β-induced transcriptional responses to a prometastatic state. Importantly, we identified chaperonin containing TCP1 subunit 6A (CCT6A) as an inhibitor and direct binding protein of SMAD2 and found that CCT6A suppresses SMAD2 function in NSCLC cells and promotes metastasis. Furthermore, selective inhibition of SMAD3 or CCT6A efficiently suppresses TGF-β-mediated metastasis. Our findings provide a mechanism that directs TGF-β signaling toward its prometastatic arm and may contribute to the development of therapeutic strategies targeting TGF-β for NSCLC.

TGF-β triggers rapid fibrillogenesis via a novel TβRII-dependent fibronectin-trafficking mechanism

There is increased recycling of soluble fibronectin from the cell surface for fibrillogenesis. This recycling is regulated by TGF-β in a transcription- and SMAD-independent manner via specific TβRII and integrin α5β1 interactions. The recycling of fibronectin is Rab11 dependent and is required for TGF-β–induced cell migration.

Fibronectin (FN) is a critical regulator of extracellular matrix (ECM) remodeling through its availability and stepwise polymerization for fibrillogenesis. Availability of FN is regulated by its synthesis and turnover, and fibrillogenesis is a multistep, integrin-dependent process essential for cell migration, proliferation, and tissue function. Transforming growth factor β (TGF-β) is an established regulator of ECM remodeling via transcriptional control of ECM proteins. Here we show that TGF-β, through increased FN trafficking in a transcription- and SMAD-independent manner, is a direct and rapid inducer of the fibrillogenesis required for TGF-β–induced cell migration. Whereas TGF-β signaling is dispensable for rapid fibrillogenesis, stable interactions between the cytoplasmic domain of the type II TGF-β receptor (TβRII) and the FN receptor (α5β1 integrin) are required. We find that, in response to TGF-β, cell surface–internalized FN is not degraded by the lysosome but instead undergoes recycling and incorporation into fibrils, a process dependent on TβRII. These findings are the first to show direct use of trafficked and recycled FN for fibrillogenesis, with a striking role for TGF-β in this process. Given the significant physiological consequences associated with FN availability and polymerization, our findings provide new insights into the regulation of fibrillogenesis for cellular homeostasis.