Reversal Of Epithelial-mesenchymal Transition Research Articles

Cold atmospheric plasma and silymarin nanoemulsion synergistically inhibits human melanoma tumorigenesis via targeting HGF/c-MET downstream pathway

BackgroundRecent studies claimed the important role of cold atmospheric plasma (CAP) with nanotechnology in cancer treatments. In this study, silymarin nanoemulsion (SN) was used along with air CAP as therapeutic agent to counter human melanoma.MethodsIn this study, we examined the combined treatment of CAP and SN on G-361 human melanoma cells by evaluating cellular toxicity levels, reactive oxygen and nitrogen species (RONS) levels, DNA damage, melanoma-specific markers, apoptosis, caspases and poly ADP-ribose polymerase-1 (PARP-1) levels using flow cytometer. Dual-treatment effects on the epithelial–mesenchymal transition (EMT), Hepatocyte growth factor (HGF/c-MET) pathway, sphere formation and the reversal of EMT were also assessed using western blotting and microscopy respectively. SN and plasma-activated medium (PAM) were applied on tumor growth and body weight and melanoma-specific markers and the mesenchymal markers in the tumor xenograft nude mice model were checked.ResultsCo-treatment of SN and air CAP increased the cellular toxicity in a time-dependent manner and shows maximum toxicity at 200 nM in 24 h. Intracellular RONS showed significant generation of ROS (< 3 times) and RNS (< 2.5 times) in dual-treated samples compared to control. DNA damage studies were assessed by estimating the level of γ-H2AX (1.8 times), PD-1 (> 2 times) and DNMT and showed damage in G-361 cells. Increase in Caspase 8,9,3/7 (> 1.5 times), PARP level (2.5 times) and apoptotic genes level were also observed in dual treated group and hence blocking HGF/c-MET pathway. Decrease in EMT markers (E-cadherin, YKL-40, N-cadherin, SNAI1) were seen with simultaneously decline in melanoma cells (BRAF, NAMPT) and stem cells (CD133, ABCB5) markers. In vivo results showed significant reduction in SN with PAM with reduction in tumor weight and size.ConclusionsThe use of air CAP using μ-DBD and the SN can minimize the malignancy effects of melanoma cells by describing HGF/c-MET molecular mechanism of acting on G-361 human melanoma cells and in mice xenografts, possibly leading to suitable targets for innovative anti-melanoma approaches in the future.

Role of Jagged1/STAT3 signalling in platinum-resistant ovarian cancer.

Jagged1, the essential ligand of the Notch signalling pathway, is highly expressed in metastatic prostate cancer, and its high expression in breast cancer is linked to poor survival rates. However, the mechanism of Jagged1′s involvement in platinum‐resistant ovarian cancer has not been thoroughly elucidated to date. The purpose of the present study was to investigate the roles of Jagged1 in the platinum resistance of ovarian cancer and its possible mechanisms. Compared with a platinum responsive group of ovarian epithelial cell carcinomas, we found the positive staining intensity of Notch1, Notch2, Jagged1, STAT3 and Epithelial‐mesenchymal transition (EMT) proteins were lower in a platinum‐resistant group. The DDP‐resistant ovarian cancer cell line (C13K) had a higher IC50 of DDP than its parental cell line (OV2008) (P < 0.05) and acquired an EMT phenotype and invasive characteristics. Inhibiting or knockdown of Jagged1 expression could not only reduce its capacity of migration and invasion but also reverse EMT and down‐regulate the expression of serine 727‐phosphorylated STAT3 (pS727) at the protein level but not total STAT3 or tyrosine 705‐phosphorylated STAT3 (pY705) in C13K cells. Furthermore, it was found that crosstalk between the Jagged1/Notch and JAK/STAT3 signalling pathways were involved in Jagged1‐promoting EMT in C13K cells. Experiments in vivo showed a reduced micrometastatic tumour burden in the lung, liver and spleen of mice implanted with C13K cells with knocked‐down Jagged1 compared with mice implanted with control cells. All of these results demonstrate that Jagged1 can crosstalk with the JAK/STAT3 pathway, and they all cooperate to promote the aberrant occurrence of EMT, further reinforcing the abilities of invasion and migration of platinum‐resistant ovarian cancer in vivo and in vitro.

Prevention of epithelial to mesenchymal transition in colorectal carcinoma by regulation of the E-cadherin-β-catenin-vinculin axis.

Epithelial to mesenchymal transition (EMT) is compulsory for metastatic dissemination and is stimulated by TGF-β. Although targeting EMT has significant therapeutic potential, very few pharmacological agents have been shown to exert anti-metastatic effects. BI-69A11, a competitive Akt inhibitor, displays anti-tumor activity toward melanoma and colon carcinoma. This study provides molecular and biochemical insights into the effects of BI-69A11 on EMT in colon carcinoma cells in vitro and in vivo. BI-69A11 inhibited metastasis-associated cellular migration, invasion and adhesion by inhibiting the Akt-β-catenin pathway. The underlying mechanism of BI-69A11-mediated inhibition of EMT included suppression of nuclear transport of β-catenin and diminished phosphorylation of β-catenin, which was accompanied by enhanced E-cadherin-β-catenin complex formation at the plasma membrane. Additionally, BI-69A11 caused increased accumulation of vinculin in the plasma membrane, which fortified focal adhesion junctions leading to inhibition of metastasis. BI-69A11 downregulated activation of the TGF-β-induced non-canonical Akt/NF-κB pathway and blocked TGF-β-induced enhanced expression of Snail causing restoration of E-cadherin. Overall, this study enhances our understanding of the molecular mechanism of BI-69A11-induced reversal of EMT in colorectal carcinoma cells in vitro, in vivo and in TGF-β-induced model systems.

Cyanidin-3-glucoside induces mesenchymal to epithelial transition via activating Sirt1 expression in triple negative breast cancer cells

Triple-negative breast cancer (TNBC) is a heterogeneous group of breast cancer with one common feature: distinctly metastatic nature with higher rate of relapse and shorter survival compared with other subtypes of breast cancer. The epithelial to mesenchymal transition (EMT) is highly associated with cancer metastasis. Cyanidin-3-glucoside (C3G), the most abundant anthocyanin pigment enriched in fresh fruits and vegetables, showed ideal anti-oxidant property. C3G could also inhibit certain malignant behaviors of cancer cells, however, whether repression of EMT was involved in its anti-cancer especially TNBC effect remains unknown. Herein, we report that C3G decreases the migratory and invasive nature of TNBC lines MDA-MB-231 and BT-549. Mechanistically, C3G induces reversion of EMT characterized by phenotype modulation with increased epithelial marker E-ca and ZO-1, decreased mesenchymal marker Vimentin, N-ca and EMT-associated transcription factors Snail1, Snail2. NF-κB is pivotal for EMT and Sirt1 is a NF-κB inhibitor. We show that NF-κB is attenuated and Sirt1 is induced by C3G in TNBC, respectively. And later evidence demonstrates that abrogation of Sirt1 with small interfering RNA transfection abolished NF-κB inhibition and EMT reversion by C3G. Subsequently, we show that microRNA-138(miR-138) represses Sirt1 via mRNA translation inhibition and is inhibited by C3G. Moreover, miR-138 repression is involved in Sirt1 re-activation and migratory and invasive inhibition of TNBC by C3G. Taken together, we supplied more evidence to the anti-breast cancer mechanisms of C3G.

Revisiting TGF-β and EMT

Cancer Cancer progression is enhanced by the epithelial-to-mesenchymal transition (EMT), a process mediated by transforming growth factor–β (TGF-β). EMT is thought to be a reversible process. However, Katsuno et al. found that TGF-β withdrawal did not reverse EMT induced by long-term exposure to TGF-β, which mimics what occurs during carcinoma progression. By contrast, an inhibitor of the kinase mammalian target of rapamycin reversed some EMT features in cells and metastatic breast cancer models in mice. These results may explain why TGF-β inhibitors are not effective in some cancer patients and highlight a potential alternative therapy. Sci. Signal. 12 , eaau8544 (2019).

Abstract P5-08-04: Defining chromatin accessibility profiles of partial and reversible EMT

Abstract The epithelial-to-mesenchymal transition (EMT) reversible cellular reprogramming event, used repeatedly throughout development, is hypothesized to be involved in the cell migration and consequently metastasis that ultimately contributes to most breast cancer-related fatalities. In this process, cuboidal epithelial cells, marked by the presence of tight junction proteins and cell-cell adhesions, lose their apicobasal polarity and acquire a spindle-like morphology and migratory traits. EMT was originally regarded to have only two states, with cells exhibiting either epithelial or mesenchymal phenotypes; however, recently, researchers have demonstrated the existence of a dual epithelial/mesenchymal state, termed hybrid- or partial-EMT. Due to its inherent plasticity, it is believed that EMT and its reversal mesenchymal-to-epithelial transition (MET) is, at least, partly regulated by epigenetic means such as alterations in chromatin structure. Assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) is a novel technique that employs the use of a mutant Tn5 transposase to cleave nucleosome-free DNA regions in a non-biased manner. In this investigation, we induced MCF10A mammary epithelial cells to undergo a short-term (&amp;lt;4 days) or long-term (&amp;gt;4 days) EMT. Addition and withdrawal of exogenous TGFβ1 produced partial- or full-EMT and MET conditions which were interrogated by ATAC- and RNA-seq. Hierarchical clustering of ATAC cleavage peaks revealed that pre-EMT and short- and long-term MET conditions demonstrate similar chromatin accessibility profiles with cleavage sites enriched for specific binding motifs. Notably, transcription factors typically not associated with EMT displayed dynamic enrichment in the accessible chromatin at various timepoints in our assay. Correlation with RNA-seq data reveals highly dynamic changes in gene expression suggesting dynamic and reversible use of regulatory programs. Importantly, partial-EMT cells were characterized by unique accessibility patterns, motif enrichment, and gene expression supporting the conclusion that this is not merely an intermediate but a unique state. Citation Format: Johnson KS, Hussein S, Lin Y, Taube JH. Defining chromatin accessibility profiles of partial and reversible EMT [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-08-04.

Abstract P5-08-06: Differential effects of eribulin on key transcription factors snail and slug

Abstract Microtubule targeting agents (MTAs) are a mainstay in the treatment of breast cancer and a growing body of evidence demonstrates that they have non-mitotic effects that contribute to their anticancer actions. Even after decades of clinical use, there is much to still be learned about the mechanisms of action these drugs, and differences among them, for optimal utility. MTAs rapidly alter microtubule dynamics, often within minutes, leading to significant changes in oncogenic cellular signaling. We evaluated the early effects of eribulin on key oncogenic signaling pathways following a 2 h incubation using clinically relevant concentrations and compared the effects to those initiated by other MTAs. These studies led to the identification of novel mechanisms by which MTAs disrupt oncogenic signaling and contribute to the reversal of epithelial to mesenchymal transition (EMT), including unanticipated differences among drugs. The TGF-β-mediated expression of the Snail transcription factor is a key driver pathway of EMT in breast cancer. The effects of eribulin and other MTAs on TGF-β-induced, Smad-dependent expression of Snail were evaluated. Our results show that eribulin and vinorelbine, but not paclitaxel or ixabepilone, inhibit the ability of TGF-β to promote the transcriptional induction of Snail by impeding the nuclear transport of Smad2/3 proteins in 4 triple-negative breast cancer cell lines. This study begins to explain how microtubule disruption might contribute to the eribulin-mediated EMT reversal observed in vitro, in vivo, and in patients. Slug is another member of the Snail family of transcription factors that plays a central role in breast cancer EMT. Although Snail and Slug are often grouped together due to functional similarities, it is becoming increasingly clear that Slug has an independent role in regulating stemness and cancer cell survival during partial EMT. In contrast to our findings with Snail, eribulin and vinorelbine, but not paclitaxel or ixabepilone, induced Slug expression independent of TGF-β stimulation in a subset of triple-negative breast cancer cell lines. Studies are ongoing to identify the molecular pathways and consequences of eribulin and vinorelbine-induced Slug induction, which might begin to identify biomarkers of patient response to different MTAs. This work highlights the multifaceted nature of MTA-mediated effects on EMT-associated signaling pathways in breast cancer cells and prompts a reevaluation of their differential efficacy in tumors with distinct molecular profiles. These studies are supported by Eisai Inc. Citation Format: Kaul R, Risinger AL, Mooberry SL. Differential effects of eribulin on key transcription factors snail and slug [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-08-06.

Garcinol Sensitizes NSCLC Cells to Standard Therapies by Regulating EMT-Modulating miRNAs.

Garcinol, a dietary factor obtained from Garcinia indica, modulates several key cellular signaling pathways as well as the expression of miRNAs. Acquired resistance to standard therapies, such as erlotinib and cisplatin, is a hallmark of non-small cell lung cancer (NSCLC) cells that often involves miRNA-regulated epithelial-to-mesenchymal transition (EMT). We used A549 cells that were exposed to transforming growth factor beta 1 (TGF-β1), resulting in A549M cells with mesenchymal and drug resistant phenotype, and report that garcinol sensitized resistant cells with mesenchymal phenotype to erlotinib as well as cisplatin with significant decrease in their IC50 values. It also potentiated the apoptosis-inducing activity of erlotinib in A549M and the endogenously mesenchymal H1299 NSCLC cells. Further, garcinol significantly upregulated several key EMT-regulating miRNAs, such as miR-200b, miR-205, miR-218, and let-7c. Antagonizing miRNAs, through anti-miRNA transfections, attenuated the EMT-modulating activity of garcinol, as determined by mRNA expression of EMT markers, E-cadherin, vimentin, and Zinc Finger E-Box Binding Homeobox 1 (ZEB1). This further led to repression of erlotinib as well as cisplatin sensitization, thus establishing the mechanistic role of miRNAs, particularly miR-200c and let-7c, in garcinol-mediated reversal of EMT and the resulting sensitization of NSCLC cells to standard therapies.

Reversal of Triple-Negative Breast Cancer EMT by miR-200c Decreases Tryptophan Catabolism and a Program of Immunosuppression.

Tryptophan-2,3-dioxygenase (TDO2), a rate-limiting enzyme in the tryptophan catabolism pathway, is induced in triple-negative breast cancer (TNBC) by inflammatory signals and anchorage-independent conditions. TNBCs express extremely low levels of the miR-200 family compared with estrogen receptor-positive (ER+) breast cancer. In normal epithelial cells and ER+ breast cancers and cell lines, high levels of the family member miR-200c serve to target and repress genes involved in epithelial-to-mesenchymal transition (EMT). To identify mechanism(s) that permit TNBC to express TDO2 and other proteins not expressed in the more well-differentiated ER+ breast cancers, miRNA-200c was restored in TNBC cell lines. The data demonstrate that miR-200c targeted TDO2 directly resulting in reduced production of the immunosuppressive metabolite kynurenine. Furthermore, in addition to reversing a classic EMT signature, miR-200c repressed many genes encoding immunosuppressive factors including CD274/CD273, HMOX-1, and GDF15. Restoration of miR-200c revealed a mechanism, whereby TNBC hijacks a gene expression program reminiscent of that used by trophoblasts to suppress the maternal immune system to ensure fetal tolerance during pregnancy. IMPLICATIONS: Knowledge of the regulation of tumor-derived immunosuppressive factors will facilitate development of novel therapeutic strategies that complement current immunotherapy to reduce mortality for patients with TNBC.

A mediator of phosphorylated Smad2/3, evodiamine, in the reversion of TAF-induced EMT in normal colonic epithelial cells.

Purpose Transdifferentiation exists within stromal cells in the tumour microenvironment. Transforming growth factor-β (TGF-β) secreted by tumour-associated fibroblasts (TAFs) affects the differentiation states of epithelial cells, including epithelial-mesenchymal transition (EMT). Evodiamine, a natural drug, can regulate differentiation. However, the specific effects and relative mechanisms of evodiamine remain unknown. Design We used four models to observe the influence of TAF-like CCD-18Co cells on the colon epithelial cell line HCoEpiC: the 3D- and 2D-mono-culture system, Transwell and direct co-culture model. Additionally, we established conditioned medium from CCD-18Co cells. The TGF-β pathway inhibitor LY364947 and evodiamine were added. Morphological changes and classical EMT markers were observed and detected using phase contrast microscopy and immunofluorescence. Cell migration was measured by the wound-healing assay. Western blotting was performed to detect the TGF-β/Smad signalling pathway. Results CCD-18Co cells induced EMT-like changes in the 2D- and 3D-cultured epithelial cell line HCoEpiC, accompanied by high expression of ZEB1 and Snail and the enhancement of migration. Moreover, CCD-18Co-derived conditioned medium caused dysfunction of TGF-β/Smad signalling in EMT. Evodiamine inhibited these EMT-like HCoEpiC and their migration. Additionally, evodiamine down-regulated the expression of ZEB1/Snail and up-regulated the expression of phosphorylated Smad2/3 (pSmad2/3). Evodiamine also increased the ratios of pSmad2/Smad2 and pSmad3/Smad3. Conclusion Based on our observations, evodiamine can reverse the TAF-induced EMT-like phenotype in colon epithelial cells, which may be associated with its mediation of phosphorylated Smad2 and Smad3 expression.

Blockade of TGF-β signaling with novel synthetic antibodies limits immune exclusion and improves chemotherapy response in metastatic ovarian cancer models

ABSTRACTEpithelial ovarian cancer (EOC) is a leading cause of cancer-related death in women. EOC is often diagnosed at late stages, with peritoneal metastases and ascites production. Current surgery and platinum-based chemotherapy regimes fail to prevent recurrence in most patients. High levels of Transforming growth factor-β (TGF-β) within ascites has been linked to poor prognosis. TGF-β signaling promotes epithelial-mesenchymal transition (EMT) in EOC tumor cells, and immune suppression within the tumor microenvironment, with both contributing to chemotherapy resistance and metastasis. The goal of this study was to develop specific synthetic inhibitory antibodies to the Type II TGF-β receptor (TGFBR2), and test these antibodies in EOC cell and tumor models. Following screening of a phage-displayed synthetic antigen-binding fragment (Fab) library with the extracellular domain of TGFBR2, we identified a lead inhibitory Fab that suppressed TGF-β signaling in mouse and human EOC cell lines. Affinity maturation of the lead inhibitory Fab resulted in several derivative Fabs with increased affinity for TGFBR2 and efficacy as suppressors of TGF-β signaling, EMT and EOC cell invasion. In EOC xenograft and syngeneic tumor models, blockade of TGFBR2 with our lead antibodies led to improved chemotherapy response. This correlated with reversal of EMT and immune exclusion in these tumor models with TGFBR2 blockade. Together, these results describe new inhibitors of the TGF-β pathway that improve antitumor immunity, and response to chemotherapy in preclinical EOC models.

Metformin sensitizes hypoxia-induced gefitinib treatment resistance of HNSCC via cell cycle regulation and EMT reversal.

ObjectivesThe objectives of this study were to explore the mechanisms of metformin sensitization to hypoxia-induced gefitinib treatment in resistant head and neck squamous cell carcinoma (HNSCC) and evaluate the effects of this combined treatment strategy.MethodsThe effects of gefitinib treatment on HNSCC were measured under normoxic and hypoxic conditions. The relationship between hypoxia and cell cycle and epithelial–mesenchymal transition (EMT) in tumor cells were analyzed. Palbociclib and LY294002 were used in combination with gefitinib to evaluate the effects on HNSCC cell cytotoxicity during hypoxia. Finally, metformin was used to evaluate the sensitizing effects of gefitinib treatment on HNSCC in vivo and in vitro.ResultsCell viability and apoptosis assays demonstrated a significant difference in HNSCC cells treated with gefitinib between the normoxia and hypoxia groups. Hypoxia induced the expression of cyclin D1, decreased the percentage of cells in G1, and promoted the EMT of tumor cells. Both palbociclib and LY294002 enhanced gefitinib-induced cytotoxicity of HNSCC cells under hypoxic conditions. Encouragingly, metformin sensitized HNSCC to gefitinib treatment in vivo and in vitro.ConclusionHypoxia promotes G1–S cell cycle progression and EMT in HNSCC, resulting in gefitinib treatment resistance. Metformin sensitizes HNSCC to gefitinib treatment, which might serve as a novel combined treatment strategy.

Long noncoding RNA HOTAIR knockdown inhibits autophagy and epithelial-mesenchymal transition through the Wnt signaling pathway in radioresistant human cervical cancer HeLa cells.

Cervical cancer is one of the most common female malignancies around the world, and radiation resistance is a major obstacle to cancer therapy. Previously, overexpression of the long noncoding ribonucleic acid (RNA) (lncRNA) HOX transcript antisense RNA (HOTAIR) has been found to be associated with the invasion and metastasis capacities of several epithelial cancers, including cervical cancer. To gain insights into the molecular mechanisms of HOTAIR in cervical cancer resistance to radiotherapy, we investigated cellular autophagy and epithelial-to-mesenchymal transition (EMT) in radioresistant human cervical cancer HeLa cells when HOTAIR was suppressed.HOTAIR levels were quantified in cancerous and noncancerous cervical tissues obtained from 108 patients with cervical cancer. Next, we inhibited HOTAIR by RNA interference and activated the Wnt signaling pathway by LiCl in radioresistant HeLa cells to investigate the regulatory mechanisms for the HOTAIR mediating Wnt signaling pathway.We determined that the upregulated HOTAIR may contribute to cervical cancer progression. We found that the short interfering ribonucleic acid (siRNA)-mediated knockdown of HOTAIR disturbed the Wnt signaling pathway, reduced autophagy, inhibited EMT, decreased cell proliferation, and induced apoptosis in radioresistant HeLa cells. It is worthy to note that the combination treatment of siRNA-HOTAIR and LiCl demonstrated that the activation of the Wnt signaling pathway is responsible for the beneficial effect of HOTAIR knockdown in enhancing sensitivity to radiotherapy in radioresistant HeLa cells.Together, our results revealed an important role of HOTAIR in regulating cervical cancer resistance to radiotherapy. Functional suppression of HOTAIR could enhance sensitivity to radiotherapy by reduction of autophagy and reversal of EMT through the suppression of the Wnt signaling pathway.

MicroRNA‑301a targets WNT1 to suppress cell proliferation and migration and enhance radiosensitivity in esophageal cancer cells.

Esophageal cancer (EC) is one of the leading causes of death among malignancies. Radiotherapy for esophageal squamous cell carcinoma (ESCC) patients is limited by resistance to ionizing radiation (IR). An increasing body of evidence has demonstrated that aberrant expression of microRNA‑301a (miR‑301a) contributes to cancer progression and sensitivity to radiation. The aim of the present study was to investigate the exact functions and potential mechanisms of miR‑301a in ESCC radioresistance. Initially, the miR‑301a‑transfected radioresistant ESCC cells KYSE‑150R exhibited a decreased proliferation rate, and enhanced radiosensitivity and migration, whereas downregulation of miR‑301a in radiosensitive KYSE‑150 cells produced the opposite results. miR‑301a regulates WNT1 expression at both the mRNA and protein levels. Furthermore, dual‑luciferase reporter assays revealed that WNT1 was a target gene of miR‑301a. In addition, the expression of miR‑301a markedly affected the expression of Wnt/β‑catenin‑related proteins such as β‑catenin and cyclinD1. Finally, overexpression of miR‑301a inhibited epithelial‑mesenchymal transition (EMT) conversion by directly targeting Snail and vimentin in radioresistant‑ESCC cell lines; however, no inhibitory effects were exerted on Twist. Collectively, these results indicated that miR‑301a increased the radiosensitivity and inhibited the migration of radioresistant‑ESCC cells by targeting WNT1, thereby inactivating the Wnt/β‑catenin signaling pathway and EMT reversal. Thus, miR‑301a may be a potential therapeutic target for the treatment of EC radioresistance.

Synergistic antitumor effect of a γ-secretase inhibitor PF-03084014 and sorafenib in hepatocellular carcinoma.

As a multi-kinase inhibitor, sorafenib is beneficial in around 30% of hepatocellular carcinoma (HCC) patients; however, HCC patients develop acquired drug resistance quickly. Clinical benefits of sorafenib, in combination with transarterial chemoembolization (TACE), radiotherapy, and other chemodrugs are limited. We investigated the efficacy and mechanisms of Notch signaling inhibition as adjuvant to sorafenib in HCC spheroid-derived in vitro and in vivo tumor models, using the γ-secretase inhibitor (GSI), PF-03084014. The combination of PF-03084014 plus sorafenib inhibited proliferation and self-renewal of HCC spheroids (stem-like cancer cells). PF-03084014 significantly enhanced antitumor activity of sorafenib; both agents at low dose reached synergistic tumor growth suppression of HCC spheroid-derived orthotopic tumors. The Notch1-Snail1 signaling pathway contributed to sorafenib resistance via increasing epithelial-mesenchymal transition (EMT) and EMT-mediated cancer stem cell (CSC) features, such as increased expression of Snail1, N-cadherin, ABCG2, and the stem cell related genes Nanog and Oct4, and decreased expression of E-cadherin. Anti-tumor activity of the combination therapy was associated with decreased expression of survival signals (Mek/Erk, PI3K/Akt) and reduced microvessel density. PF-03084014 plus sorafenib targets Notch1-Snail1 signaling to reverse EMT and EMT-mediated CSC stemness in the tumors. These synergistic effects provide a rationale to utilize GSIs, in combination with sorafenib, as a new therapeutic strategy for the treatment of HCC.

Retracted: Suppression of BMX‐ARHGAP fusion gene inhibits epithelial‐mesenchymal transition in gastric cancer cells via RhoA‐mediated blockade of JAK/STAT axis

Gastric cancer (GC) is one of the main causes of cancer-related mortality worldwide. Epithelial-mesenchymal transition (EMT) is an important biological process involving the process by which malignant tumor cells obtain the ability of migration, invasion, resistance of apoptosis, and degradation in the extracellular matrix. The current study aimed at investigating whether bone marrow X kinase Rho GTPase activating protein 12 (BMX-ARHGAP) fusion gene affects GC. First, short hairpin RNA (shRNA) against BMX-ARHGAP or BMX-ARHGAP were introduced to treat SGC-7901 cells with the highest BMX-ARHGAP among the five GC cell lines (SGC-7901, MKN-45, NCI-N87, SNU-5, and AGS). Next, cell vitality, drug resistance, migration, and invasion of SGC-7901 cells, activities of Rho and JAK/STAT axis, as well as EMT and lymph node metastasis (LNM) were evaluated. The survival rate of the mice was then determined through the transfection of the specific pathogen-free NOD-SCID mice with treated SGC-7901 cells. The results showed that BMX-ARHGAP expression was associated with the infiltration degree of GC tumor and poor prognosis for patients with GC. BMX-ARHGAP silencing was found to play an inhibitory role in the Rho and JAK/STAT axis to reduce cell vitality, drug resistance, migration and invasion, reverse EMT process, as well as inhibit LNM. BMX-ARHGAP overexpression was observed to have induced effects on GC cells as opposed to those inhibited by BMX-ARHGAP silencing. The survival rate of mice was increased after transfection with silenced BMX-ARHGAP. These findings provided evidence that the suppression of BMX-ARHGAP resulted in the inhibition of RhoA to restraint the development of GC cells by blocking the JAK/STAT axis.

A molecular portrait of epithelial\u2013mesenchymal plasticity in prostate cancer associated with clinical outcome

The propensity of cancer cells to transition between epithelial and mesenchymal phenotypic states via the epithelial–mesenchymal transition (EMT) program can regulate metastatic processes, cancer progression, and treatment resistance. Transcriptional investigations using reversible models of EMT, revealed the mesenchymal-to-epithelial reverting transition (MErT) to be enriched in clinical samples of metastatic castrate resistant prostate cancer (mCRPC). From this enrichment, a metastasis-derived gene signature was identified that predicted more rapid cancer relapse and reduced survival across multiple human carcinoma types. Additionally, the transcriptional profile of MErT is not a simple mirror image of EMT as tumour cells retain a transcriptional “memory” following a reversible EMT. This memory was also enriched in mCRPC samples. Cumulatively, our studies reveal the transcriptional profile of epithelial–mesenchymal plasticity and highlight the unique transcriptional properties of MErT. Furthermore, our findings provide evidence to support the association of epithelial plasticity with poor clinical outcomes in multiple human carcinoma types.

TGF-β receptor I inhibitor enhances response to enzalutamide in a pre-clinical model of advanced prostate cancer.

Prostate cancer progression is navigated by the androgen receptor (AR) and transforming-growth factor-β (TGF-β) signaling. We previously demonstrated that aberrant TGF-β signaling accelerates prostate tumor progression in a transgenic mouse model of prostate cancer via effects on epithelial-mesenchymal transition (EMT), driving castration-resistant prostate cancer (CRPC). This study examined the antitumor effect of the combination of TGF-β receptor I (TβRI) inhibitor, galunisertib, and FDA-approved antiandrogen enzalutamide, in our pre-clinical model. Age-matched genotypically characterized DNTGFβRII male mice were treated with either galunisertib and enzalutamide, in combination or as single agents in three "mini"-trials and the effects on tumor growth, phenotypic EMT, and actin cytoskeleton were evaluated. Galunisertib in combination with enzalutamide significantly suppressed prostate tumor growth, by increasing apoptosis and decreasing cell proliferation of tumor cell populations compared to the inhibitor as a monotherapy (P < 0.05). The combination treatment dramatically reduced cofilin levels, actin cytoskeleton regulator, compared to single agents. Treatment with galunisertib targeted nuclear Smad4 protein (intracellular TGF-β effector), but had no effect on nuclear AR. Consequential to TGF-β inhibition there was an EMT reversion to mesenchymal-epithelial transition (MET) and re-differentiation of prostate tumors. Elevated intratumoral TGF-β1 ligand, in response to galunisertib, was blocked by enzalutamide. Our results provide novel insights into the therapeutic value of targeting TGF-β signaling to overcome resistance to enzalutamide in prostate cancer by phenotypic reprogramming of EMT towards tumor re-differentiation and cytoskeleton remodeling. This translational work is significant in sequencing TGF-β blockade and antiandrogens to optimize therapeutic response in CRPC.

A Randomized Phase II Study of Eribulin/Cyclophosphamide or Docetaxel/Cyclophosphamide as Neoadjuvant Therapy in Operable HER2-negative Breast Cancer

BackgroundEribulin mesylate is a non–taxane microtubule inhibitor effective in the treatment of metastatic breast cancer refractory to anthracyclines and taxanes. In preclinical studies, additional mechanisms of eribulin included reversal of epithelial mesenchymal transition and tumor vascular remodeling. The present study compared the safety and efficacy of eribulin plus cyclophosphamide (ErC) to docetaxel plus cyclophosphamide (TC) as neoadjuvant therapy for operable HER2− breast cancer. Patients and MethodsWomen with invasive HER2− breast adenocarcinoma with no distant metastases were eligible. After a 10-patient safety lead-in, the patients were randomized 2:1 to receive either ErC (eribulin 1.4 mg/m2 on days 1 and 8 plus cyclophosphamide 600 mg/m2 on day 1) or TC (docetaxel 75 mg/m2 plus cyclophosphamide 600 mg/m2 on day 1) administered every 21 days for 6 cycles, followed by surgery. The pathologic complete response (pCR) rate was the primary endpoint. Tumor samples collected at baseline and at surgery were assayed for select epithelial mesenchymal transition and vascular density markers: E-cadherin, vimentin, and CD31 expression. ResultsA total of 76 patients were enrolled. Of the 76 patients, 10 received ErC in the lead-in phase and 66 were randomized to ErC (n = 44) or TC (n = 22). The pCR rates with ErC and TC were 13% and 9%, respectively. Both regimens produced frequent neutropenia and peripheral neuropathy. Both regimens increased vascular density as measured by CD31 staining. ConclusionThe neoadjuvant regimens of ErC and TC resulted in relatively low pCR rates in this patient population. No unexpected toxicities were observed. Our results also provided no suggestion that ErC is a neoadjuvant treatment with greater efficacy than that of standard regimens.

AKR1C3, a crucial androgenic enzyme in prostate cancer, promotes epithelial-mesenchymal transition and metastasis through activating ERK signaling

BackgroundAKR1C3, as a crucial androgenic enzyme, facilitates intratumoral androgen biosynthesis and androgen receptor activation in castration-resistant prostate cancer (PCa). The data has shown that AKR1C3 expression is significantly elevated in clinical metastatic PCa specimens, indicating a potential role of AKR1C3 in PCa metastasis. MethodsC4-2, 22RV1-T, and PC-3 cells with higher AKR1C3 expression were selected and treated with several specific AKR1C3 shRNAs or small molecule inhibitor, and the cell migration and invasion abilities were detected by wound healing assay and Transwell assay. The expression of several epithelial-mesenchymal transition (EMT) markers (i.e., E-cadherin and vimentin) and the related transcription factors (i.e., ZEB1, TWIST1, and SLUG) was examined by Western blot or quantitative PCR assays, and the phosphorylation of AKT or ERK was detected by Western blot. Also, subcutaneous xenografts with 22RV1-T sublines were used to detect in vivo tumor growth, and the expression of E-cadherin, vimentin, and ZEB1 by immunohistochemical staining. The correlation between AKR1C3 and EMT marker expression in clinical specimens was analyzed. ResultsAKR1C3 was overexpressed in more aggressive PCa cell lines regardless of the androgen receptor status. Knockdown of AKR1C3 expression or inhibition of AKR1C3 activity could significantly suppress cell migration and invasion abilities in vitro, and increase E-cadherin expression but decrease vimentin expression, in which the phosphorylation of ERK and the EMT-associated transcription factor expression were specifically down-regulated. Also, knockdown of AKR1C3 could suppress PCa tumorigenesis and reverse EMT in vivo. Moreover, there was a significant correlation between AKR1C3 expression and EMT in human PCa specimens from public tissue microarray. ConclusionsAKR1C3 is a novel EMT driver in PCa metastasis through activating ERK signaling.