Upregulation of Twist in oesophageal squamous cell carcinoma is associated with neoplastic transformation and distant metastasis

Novel TCF4:TCF12 heterodimer inhibits glioblastoma growth

TWIST1 (TW) is a pro-oncogenic basic helix-loop-helix (bHLH) transcription factor and promotes the hallmark features of malignancy (e.g., cell invasion, cancer cell stemness, and treatment resistance), which contribute to poor prognoses of glioblastoma (GBM). We previously reported that specific TW dimerization motifs regulate unique cellular phenotypes in GBM. For example, the TW:E12 heterodimer increases periostin (POSTN) expression and promotes cell invasion. TW dimer-specific transcriptional regulation requires binding to the regulatory E-box consensus sequences, but alternative bHLH dimers that balance TW dimer activity in regulating pro-oncogenic TW target genes are unknown. We leveraged the ENCODE DNase I hypersensitivity data to identify E-box sites and tethered TW:E12 and TW:TW proteins to validate dimer binding to E-boxes in vitro. Subsequently, TW knockdown revealed a novel TCF4:TCF12 bHLH dimer occupying the same TW E-box site that, when expressed as a tethered TCF4:TCF12 dimer, markedly repressed POSTN expression and extended animal survival. These observations support TCF4:TCF12 as a novel dimer with tumor-suppressor activity in GBM that functions in part through displacement of and/or competitive inhibition of pro-oncogenic TW dimers at E-box sites.

In vitro and in vivo anti-tumor activity of Coenzyme Q0 against TWIST1-overexpressing HNSCC cells: ROS-mediated inhibition of EMT/metastasis and autophagy/apoptosis induction

HNSCC (Head and Heck Squamous Cell Carcinoma) is a reasonably prevalent cancer with a high mortality rate. In this study, we tried to examine the anti-metastasis and apoptosis/autophagy actions of Coenzyme Q₀ (CoQ₀, 2,3-dimethoxy-5-methyl-1,4-benzoquinone), a derivative of Antrodia camphorata in HNCC TWIST1 overexpressing (FaDu-TWIST1) cells as well as in vivo tumor xenograft mice model. Using fluorescence based cellular assays, western blot and nude mice tumor xenografts, we determined that CoQ₀ effectively reduced cell viability and displayed rapid morphological changes in FaDu-TWIST1 cells compared to FaDu cells. Non/sub-cytotoxic concentrations of CoQ₀ treatment reduces the cell migration by downregulating TWIST1 and upregulating E-cadherin. Apoptosis produced by CoQ₀ was mostly related with caspase-3 activation, PARP cleavage, and VDAC-1 expression. The FaDu-TWIST1 cells treated with CoQ₀ exhibits autophagy-mediated LC3-II accumulation and acidic vesicular organelles (AVOs) formation. Pre-treatment with 3-MA and CoQ effectively prevented CoQ₀-induced cell death and CoQ₀-triggered autophagy in FaDu-TWIST cells as a death mechanism. CoQ₀ induces ROS production in FaDu-TWIST1 cells and NAC pre-treatment significantly reduces anti-metastasis, apoptosis, and autophagy. Likewise, ROS-mediated AKT inhibition regulates CoQ₀-induced apoptosis/autophagy in FaDu-TWIST1 cells. In vivo studies exhibit, CoQ₀ effectively delays and reduces the tumor incidence and burden in FaDu-TWIST1-xenografted nude mice. Current findings display, CoQ₀ exhibits a novel anti-cancer mechanism hence, it might be appropriate for anticancer therapy, and a new potent drug for HNSCC.

In vitro and in vivo anti-tumor activity of Antrodia salmonea against twist-overexpressing HNSCC cells: Induction of ROS-mediated autophagic and apoptotic cell death

Head and neck squamous cell carcinoma (HNSCC) is a relatively common malignancy, characterized by lethal morbidity. Herein, we attempted to investigate the autophagy/apoptosis activities of the submerged fermented broths of Antrodia salmonea (AS) in HNSCC Twist-overexpressing (OECM-1 and FaDu-Twist) cells. AS (0-150 μg/mL) effectively reduced cell viability, colony formation, and downregulated Twist expression in OECM-1 and FaDu-Twist cells compared to FaDu cells. AS- induced apoptosis was mainly associated with activation of caspase-3, PARP cleavage, increased expression of VDAC-1 and disproportionation of Bax/Bcl-2. Annexin V/PI staining suggested late apoptosis induction by AS treatment. AS exhibits enhanced autophagy process mediated via LC3-I/II accumulation, increased acidic vesicular organelles (AVOs) formation and p62/SQSTM1 expression feeding into the apoptotic program. However, pre-treatment with autophagy blockers 3-MA and CQ significantly diminished AS-induced cell death. Additionally, suppression of AS-induced ROS release by treatment with antioxidant N-acetylcysteine (NAC) resulted in reduction of apoptotic and autophagic cell death. In vivo studies strengthened the above observations and showed that AS effectively reduced the tumor volume and tumor weight in OECM-1-xenografted nude mice. This study discovered that Antrodia salmonea exhibits a novel anti-cancer mechanism which could be harnessed as a new potent drug for HNSCC treatment.

Cyclophilin A regulates A549 cells apoptosis via stabilizing Twist1 protein

Cyclophilin A (CypA) is an essential member of the immunophilin family. As an intracellular target of immunosuppressive drug cyclosporin A (CsA) or a peptidyl-prolyl cis/trans isomerase (PPIase), it catalyzes the cis-trans isomerization of proline amidic peptide bonds, through which, it regulates a variety of biological processes, such as intracellular signaling, transcription, and apoptosis. In this study, we found that intracellular CypA enhanced Twist1 phosphorylation at Ser68 and inhibited apoptosis in A549 cells. Mechanistically, CypA could mediate the phosphorylation of Twist1 at Ser68 via p38 MAPK, which inhibited its ubiquitination-mediated degradation. In addition, CypA increased Twist-p65 interaction and nuclear accumulation, which regulated Twist1-dependent expression of CDH1 and CDH2. Our findings collectively indicated the role of CypA in Twist1-mediated A549 cells apoptosis through stabilizing Twist1 protein.

Clinical Significance of TWIST-Positive Circulating Tumor Cells in Patients with Esophageal Squamous Cell Carcinoma

BACKGROUND/AIMS

Unlike other gastrointestinal tract cancers, there are relatively few reports on the clinical significance of circulating tumor cells (CTCs) and TWIST, a marker of epithelial-mesenchymal transition, in patients with esophageal squamous cell carcinoma (ESCC). This study aimed to evaluate the clinical significance of TWIST expression in CTCs in patients with ESCC.

METHODS

Peripheral blood samples for CTC analyses were prospectively obtained from 52 patients with ESCC prior to treatment between September 2017 and September 2019. CTCs were detected using a centrifugal microfluidic system based on a fluid-assisted separation technique, and CTCs positive for TWIST on immunostaining were defined as TWIST (+) CTCs.

RESULTS

Of the 52 patients with ESCC, CTCs and TWIST (+) CTCs were detected in 44 patients (84.6%) and 39 patients (75.0%), respectively. The CTC and TWIST (+) CTC counts were significantly higher in patients aged >65 years and those who had a large tumor (>3 cm) than in those aged ≤65 years and those who had a small tumor (≤3 cm), respectively. There were no differences in CTC and TWIST (+) CTC counts according to tumor location, histologic grade, or TNM stage. TWIST (+) CTCs were significantly associated with histologic grade; a proportion of TWIST (+) CTCs ≥0.5 was significantly associated with advanced histologic grade. Other clinicopathologic characteristics such as sex, age, tumor location, tumor size, and TNM stages were not significantly associated with TWIST (+) CTCs.

CONCLUSIONS

Our study showed that TWIST (+) CTCs were frequently detected in patients with ESCC, and a high proportion of TWIST (+) CTCs was associated with poor differentiation.

Regulatory Role of the Transcription Factor Twist1 in Cancer-Associated Muscle Cachexia

Muscle cachexia is a catabolic response, usually takes place in various fatal diseases, such as sepsis, burn injury, and chronic kidney disease. Muscle cachexia is also a common co-morbidity seen in the vast majority of advanced cancer patients, often associated with low quality of life and death due to general organ dysfunction. The triggering events and underlying molecular mechanisms of muscle wasting are not yet clearly defined. Our recent study has shown that the ectopic expression of Twist1 in muscle progenitor cells is sufficient to drive muscle structural protein breakdown and attendant muscle atrophy, reminiscent of muscle cachexia. Intriguingly, muscle Twist1 expression is highly induced in cachectic muscles from several mouse models of pancreatic ductal adenocarcinoma (PDAC), raising the interesting possibility that Twist1 may mediate PDAC-driven muscle cachexia. Along these lines, both genetic and pharmacological inactivation of Twist1 function was highly significant at protecting against cancer cachexia, which translated into a significant survival benefit in the experimental PDAC animals. From a translational perspective, elevated expression of Twist1 is also detected in cancer patients with severe muscle wasting, implicating a role of Twist1 in cancer cachexia, and further providing a possible target for therapeutic attenuation of cachexia to improve cancer patient survival. In this article, we will briefly summarize how Twist1 acts as a master regulator of tumor-induced cachexia, and discuss the relevance of our findings to muscle wasting diseases in general. The mechanism of decreased muscle mass in various catabolic conditions is thought to rely on similar pathways, and, therefore, Twist1-induced cancer cachexia may benefit diverse groups of patients with clinical complications associated with loss of muscle mass and functions, beyond the expected benefits for cancer patients.

CBX7 binds the E-box to inhibit TWIST-1 function and inhibit tumorigenicity and metastatic potential

Deaths from ovarian cancer usually occur when patients succumb to overwhelmingly numerous and widespread micrometastasis. Whereas epithelial-mesenchymal transition is required for epithelial ovarian cancer cells to acquire metastatic potential, the cellular phenotype at secondary sites and the mechanisms required for the establishment of metastatic tumors are not fully determined. Using in vitro and in vivo models we show that secondary epithelial ovarian cancer cells (sEOC) do not fully reacquire the molecular signature of the primary epithelial ovarian cancer cells from which they are derived. Despite displaying an epithelial morphology, sEOC maintains a high expression of the mesenchymal effector, TWIST-1. TWIST-1 is however transcriptionally nonfunctional in these cells as it is precluded from binding its E-box by the PcG protein, CBX7. Deletion of CBX7 in sEOC was sufficient to reactivate TWIST-1-induced transcription, prompt mesenchymal transformation, and enhanced tumorigenicity in vivo. This regulation allows secondary tumors to achieve an epithelial morphology while conferring the advantage of prompt reversal to a mesenchymal phenotype upon perturbation of CBX7. We also describe a subclassification of ovarian tumors based on CBX7 and TWIST-1 expression, which predicts clinical outcomes and patient prognosis.

Overexpression of JAB1 promotes malignant behavior and predicts poor prognosis in esophageal squamous cell carcinoma

BACKGROUND

This study investigated the expression and biological function of JAB1 in esophageal squamous cell carcinoma (ESCC).

METHODS

The expression of JAB1 in ESCC tissues and cells was measured using reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and western blot analysis. Kaplan-Meier survival analysis was performed to explore the effect of JAB1 expression on the prognosis of ESCC patients. Furthermore, experiments were conducted in vivo and in vitro to determine the effect of JAB1 expression on the malignant behavior of ESCC cells.

RESULTS

Compared with adjacent tissues, JAB1 was highly overexpressed in cancer tissues (P = 0.01). Univariate and multivariate analyses of clinical data indicated that patients with JAB1 overexpression had a worse prognosis (P = 0.001 and P = 0.049, respectively). Cell function experiments and tumorigenesis experiments in nude mice showed that the upregulation of JAB1 might promote malignant behavior, and vice versa.

CONCLUSIONS

Overexpression of JAB1 promoted the proliferation, migration, and invasion of ESCC cells, and was significantly associated with poor prognosis of ESCC patients. Therefore, JAB1 could be considered as a promising prognostic factor and a possible target for the specific therapy of ESCC.

KEY POINTS

In this study, we found that JAB1 was highly overexpressed in cancer tissues, which could influence the malignant behavior of ESCC cells, and was significantly associated with poor prognosis of ESCC patients.

Overexpressed PKMYT1 promotes tumor progression and associates with poor survival in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors worldwide and the 5-year overall survival rate remains poor. Protein kinase, membrane associated tyrosine/threonine (PKMYT1) is overexpressed in several cancers and participate in tumor progression. However, the mechanism of PKMYT1 in ESCC is unclear.

PURPOSE

The objective of our study was to demonstrate the the expression and role of PKMYT1 in ESCC.

PATIENTS AND METHODS

  We detected the expression of PKMYT1 in ESCC patients and analysed the correlation with overall survival time and disease-free survival time. Then we detected PKMYT1 expression in ESCC cell lines and immortalized human esophageal epithelial cell line. Down-regulated PKMYT1 was carried out in KYSE70 and KYSE450 cells to invetigate the mechanism of PKMYT1 in ESCC cells.

RESULTS

PKMYT1 was up-regulated in tumor tissues and ESCC cell lines, and higher expression of PKMYT1 correlated with poorer overall survival in ESCC patients. Besides, in ESCC cell lines KYSE70 and KYSE450, knocking down PKMYT1 allowed more cells to skip G2/M checkpoint to complete mitosis, which promoted cell apoptosis, inhibited cell proliferation, and prevented the EMT phenotype in vitro. Meantime, we also observed that down-regulated PKMYT1 in ESCC cells suppressed AKT/mTOR signaling pathway. These results demonstrated PKMYT1 may act as an oncogene in ESCC.

CONCLUSION

PKMYT1 plays an crutial role in ESCC progression, downregulated PKMYT1 might inhibit the development of ESCC by AKT/mTOR signaling pathway, and might be a novel target in the treatment of ESCC.

Matrix Hyaluronan-CD44 Interaction Activates MicroRNA and LncRNA Signaling Associated With Chemoresistance, Invasion, and Tumor Progression

Tumor malignancies involve cancer cell growth, issue invasion, metastasis and often drug resistance. A great deal of effort has been placed on searching for unique molecule(s) overexpressed in cancer cells that correlate(s) with tumor cell-specific behaviors. Hyaluronan (HA), one of the major ECM (extracellular matrix) components have been identified as a physiological ligand for surface CD44 isoforms which are frequently overexpressed in malignant tumor cells during cancer progression. The binding interaction between HA and CD44 isoforms often stimulates aberrant cellular signaling processes and appears to be responsible for the induction of multiple oncogenic events required for cancer-specific phenotypes and behaviors. In recent years, both microRNAs (miRNAs) (with ~20–25 nucleotides) and long non-coding RNAs (lncRNAs) (with ~200 nucleotides) have been found to be abnormally expressed in cancer cells and actively participate in numerous oncogenic signaling events needed for tumor cell-specific functions. In this review, I plan to place a special emphasis on HA/CD44-induced signaling pathways and the presence of several novel miRNAs (e.g., miR-10b/miR-302/miR-21) and lncRNAs (e.g., UCA1) together with their target functions (e.g., tumor cell migration, invasion, and chemoresistance) during cancer development and progression. I believe that important information can be obtained from these studies on HA/CD44-activated miRNAs and lncRNA that may be very valuable for the future development of innovative therapeutic drugs for the treatment of matrix HA/CD44-mediated cancers.

Glaucocalyxin A reverses EMT and TGF-β1-induced EMT by inhibiting TGF-β1/Smad2/3 signaling pathway in osteosarcoma

Metastatic osteosarcoma usually has an unsatisfactory response to the current standard chemotherapy and causes poor prognosis. Currently, epithelial-mesenchymal transition (EMT) is reported as a critical event in osteosarcoma metastasis. Glaucocalyxin A, a bioactive ent-kauranoid diterpenoid, exerts anti-cancer effect on osteosarcoma by inducing apoptosis in previous study. However, the effect of Glaucocalyxin A on EMT and metastasis of osteosarcoma is unclear. In this study, we investigated the potential mechanisms of Glaucocalyxin A on EMT and metastasis of osteosarcoma. We found that Glaucocalyxin A inhibited migration and invasion of MG-63 and 143B cells. Moreover, Glaucocalyxin A increased the protein and mRNA levels of E-cadherin and decreased the protein and transcription expression of N-cadherin, Vimentin. Glaucocalyxin A also inhibited the protein and mRNA levels of EMT-associated transcription factor including Snail and Slug. Furthermore, Glaucocalyxin A inhibited transforming growth factor-β1 (TGF-β1)-induced migration, invasion and EMT of low-metastatic osteosarcoma U2OS cells. Glaucocalyxin A inhibited TGF-β-induced phosphorylation of Smad 2/3 in osteosarcoma U2OS cells. Finally, we established transplanted metastatic models of highly metastatic osteosarcoma 143B cells. Glaucocalyxin A inhibited lung metastasis in vivo. Interestingly, Glaucocalyxin A increased the protein expression of E-cadherin and reduced the protein expression of N-cadherin and Vimentin. Glaucocalyxin A inhibited the protein expression of Snail and Slug in vivo. In summary, this study demonstrated that Glaucocalyxin A inhibited EMT and TGF-β1-induced EMT by inhibiting TGF-β1/Smad2/3 signaling pathway in osteosarcoma. Therefore, Glaucocalyxin A might be a promising candidate against the metastasis of human osteosarcoma.

High SRC-1 and Twist1 expression predicts poor prognosis and promotes migration and invasion by inducing epithelial-mesenchymal transition in human nasopharyngeal carcinoma

Steroid receptor coactivator 1 (Src-1) and Twist1 are aberrantly upregulated in a variety of tumors and play an important role in tumor progression. However, the exact role of Src-1 and Twist1 in nasopharyngeal carcinoma (NPC) is uncertain. In this study, we investigated the possible prognostic value and biological effect of Src-1 and Twist1 in NPC. Src-1 and Twist1 expression was detected in a cohort of NPC patients (n = 134) by qRT-PCR. Kaplan-Meier survival analysis was used comparing overall survival (OS) and progression-free survival (PFS). Multivariate analysis was performed using the Cox proportional hazard regression model. Biologic effect of Src-1 and Twist1 in NPC cell lines was evaluated by western blot, colony formation assay, soft agar assay, scratch wound healing assay, transwell invasion assay and tumor xenografts growth. We have found that Src-1 and Twist1 were aberrantly upregulated in human NPC tissues, and associated with advanced tumor stage, distant metastasis and unfavorable prognosis. Knockdown of Src-1 or Twist1 in human NPC cell line CNE-1 suppressed colony formation, anchorage-independent growth, cell migration, invasion and tumor xenografts growth, while enforced expression of Src-1 or Twist1 in human NPC cell line HNE-2 promotes anchorage-independent growth, cell migration and invasion. In addition, Src-1 and Twist1 could suppress E-cadherin expression and increase Vimentin expression, thus suggested that Src-1 and Twist1 enhanced the malignant behaviors of NPC cells via inducing epithelial-mesenchymal transition (EMT). Our data indicated that Src-1 and Twist1 could be possible prognostic biomarkers and potential therapy targets for patients with NPC.

Oridonin prevents epithelial-mesenchymal transition and TGF-β1-induced epithelial-mesenchymal transition by inhibiting TGF-β1/Smad2/3 in osteosarcoma

Osteosarcoma is the most common primary bone tumor with highly invasive characteristic and low long-term survival. Recently, epithelial-mesenchymal transition (EMT) is reported as a key event in cancer invasion and metastasis. Oridonin, a bioactive diterpenoid, has been proved to possess anti-cancer effects. However, the effect of oridonin on EMT and metastasis of osteosarcoma is unclear. In this study, we investigated the underlying mechanism of oridonin on EMT and metastasis of osteosarcoma. We found that oridonin inhibited migration and invasion of MG-63 and 143B cells. Moreover, oridonin increased the protein expression of E-cadherin and decreased that of N-cadherin and Vimentin. Oridonin upregulated the transcription of E-cadherin and downregulated N-cadherin and Vimentin. Oridonin inhibited the protein and mRNA levels of Snail and Slug. Furthermore, oridonin inhibited TGF-β-induced phosphorylation of Smad 2/3, prevented Smad dimer translocation into the nucleus. Finally, we established metastatic models of osteosarcoma 143B cells, and found that oridonin inhibited lung metastasis in vivo. Oridonin increased the protein expression of E-cadherin and reduced N-cadherin and Vimentin. Oridonin inhibited the protein expression of Snail and Slug as well as Smad 2/3 activation. In conclusion, our study demonstrated that oridonin inhibited EMT and TGF-β1-induced EMT by inhibiting TGF-β1/Smad2/3 signaling pathway in osteosarcoma.

Long non-coding RNA NKILA inhibits migration and invasion of tongue squamous cell carcinoma cells via suppressing epithelial-mesenchymal transition

Long non-coding RNAs (lncRNAs) have emerged recently as key regulators of tumor development and progression. Our previous study identified an NF-KappaB interacting lncRNA (NKILA) which was negatively correlated with breast cancer metastasis and patient prognosis. However, its clinical significance and potential role in Tongue squamous cell carcinoma (TSCC) remain unclear. Here we show that NKILA is down-regulated in TSCC cancer tissues than that in matched adjacent noncancerous tissues. And low NKILA expression in TSCC is significantly correlated with tumor metastasis and poor patient prognosis. In vitro, overexpression of NKILA decreases TSCC cells migration and invasion. Mechanistic study shows that NKILA inhibits the phosphorylation of IκBα and NF-κB activation as well as the induction of the epithelial-mesenchymal transition (EMT) process. Ectopic expression of NKILA in Tscca cells inhibits NF-κB activator TNF-α-promoted cell migration and invasion, while applying NF-κB inhibitor Bay-117082 or JSH-23 in NKILA silenced CAL27 cells reverses cell migration capacity to lower level. In vivo experimental metastasis model also demonstrates NKILA inhibits lung metastasis of NOD/SCID mice with TSCC tumors. These results suggested that NKILA is a vital determinant of TSCC migration and invasion and NF-κB signaling pathway mediates this effect. Given the above mentioned function of NKILA, it could act as a potential predictor for overall survival in patients with TSCC and a potential therapeutic target for TSCC intervention.

Ectopic expression of TWIST1 upregulates the stemness marker OCT4 in the esophageal squamous cell carcinoma cell line KYSE30

Background

The transcription factor TWIST1 plays an important role in the epithelial–mesenchymal transition (EMT) process and in the migration, invasion and metastasis of cancer cells. OCT4, which is a homeobox transcription factor, has an important role in the self-renewal potential of cancer cells. Our aim here is to elucidate impact of ectopic expression of TWIST1 on OCT4 gene expression in esophageal squamous cell carcinoma (ESCC).

Methods

The ESCC line was KYSE30. GP293T cells were transfected with purf-IRES-GFP and pGP plasmids to produce recombinant viral particles. A semi-confluent KYSE30 culture was transduced with the prepared retroviral particles. mRNA extraction and cDNA synthesis were performed from normal KYSE30 cells and those ectopically expressing TWIST1. Expressional analysis of TWIST1 and OCT4 were performed with relative comparative real-time PCR.

Results

Ectopic expression of TWIST1 in KYSE30 cells was related to its significant overexpression: nearly nine-fold higher in GFP-hTWIST1 KYSE-30 cells than in control GFP cells. This induced expression of TWIST1 caused significant upregulation of OCT4 in GFP-hTWIST1 KYSE-30 cells: nearly eight-fold higher. In silico analysis predicted the correlation of TWIST1 and OCT4 through ETS2.

Conclusions

Overexpressed TWIST1 can be correlated with upregulation of the cancer stem cell marker OCT4 and the protein may play critical regulatory role in OCT4 gene expression. Since OCT4 is involved in the self-renewal process, the results may suggest a new linkage between TWIST1 and OCT4 in the cell biology of ESCC, highlighting the probable role of TWIST1 in inducing self-renewal.

Multiple biological functions of Twist1 in various cancers

Twist1 is a well-known regulator of transcription during embryonic organogenesis in many species. In humans, Twist1 malfunction was first linked to Saethre-Chotzen syndrome and later identified to play an essential role in tumor initiation, stemness, angiogenesis, invasion, metastasis, and chemo-resistance in a variety of carcinomas, sarcomas, and hematological malignances. In this review, we will first focus on systematically elaborating the diverse pathological functions of Twist1 in various cancers, then delineating the intricate underlying network of molecular mechanisms, based on which we will summarize current therapeutic strategies in cancer treatment that target and modulate Twist1-involved signaling pathways. Most importantly, we will put special emphasis on revealing the independence and interdependency of these multiple biological functions of Twist1, piecing together the whole delicate picture of Twist1's diversified pathological roles in different cancers and providing new perspectives to guide future research.

Autophagy supports generation of cells with high CD44 expression via modulation of oxidative stress and Parkin-mediated mitochondrial clearance

High CD44 expression is associated with enhanced malignant potential in esophageal squamous cell carcinoma (ESCC), amongst the deadliest of all human carcinomas. Although alterations in autophagy and CD44 expression are associated with poor patient outcomes in various cancer types, the relationship between autophagy and cells with high CD44 expression remains incompletely understood. In transformed esophageal keratinocytes, CD44^Low-CD24^High (CD44L) cells give rise to CD44^High-CD24^−/Low (CD44H) cells via epithelial-mesenchymal transition (EMT) in response to transforming growth factor (TGF)-β. We couple patient samples and xenotransplantation studies with this tractable in vitro system of CD44L to CD44H cell conversion to investigate the functional role of autophagy in generation of cells with high CD44 expression. We report that high expression of the autophagy marker cleaved LC3 expression correlates with poor clinical outcome in ESCC. In ESCC xenograft tumors, pharmacological autophagy inhibition with chloroquine derivatives depletes cells with high CD44 expression while promoting oxidative stress. Autophagic flux impairment during EMT-mediated CD44L to CD44H cell conversion in vitro induces mitochondrial dysfunction, oxidative stress and cell death. During CD44H cell generation, transformed keratinocytes display evidence of mitophagy, including mitochondrial fragmentation, decreased mitochondrial content and mitochondrial translocation of Parkin, essential in mitophagy. RNA interference-mediated Parkin depletion attenuates CD44H cell generation. These data suggest that autophagy facilitates EMT-mediated CD44H generation via modulation of redox homeostasis and Parkin-dependent mitochondrial clearance. This is the first report to implicate mitophagy in regulation of tumor cells with high CD44 expression, representing a potential novel therapeutic avenue in cancers where EMT and CD44H cells have been implicated, including ESCC.

TWIST1 upregulates the MAGEA4 oncogene

Overexpression of MAGEA4 oncogene has been demonstrated in different malignancies; however, little is known about its exact mechanism for overexpression. TWIST1, as a bHLH transcription factor, activates a cell migration‐invasion program involved in both embryonic and tumor development. Since MAGEA4 overexpression was statistically correlated to TWIST1, we aimed to elucidate the probable regulatory role of TWIST1 on MAGEA4 expression in KYSE30 cells. Methods: Expression pattern of MAGEA4 and TWIST1 was analyzed in 55 ESCC patients using relative comparative real‐time PCR. In silico analysis of the MAGEA4 gene was performed. Methylation status of MAGEA4 promoter was determined by quantitative methylation specific PCR (qMSP). Using a retroviral system, KYSE30 cells were transduced to ectopically express TWIST1, followed by qRT‐PCR, Western blot analysis, chromatin immunoprecipitation (ChIP), and luciferase assays to elucidate the regulatory role of TWIST1 on MAGEA4 gene expression. Results: Concomitant overexpression of MAGEA4 and TWIST1 was detected in ESCC in significant correlation with each other in different clinicopathological indices of poor prognosis (P < 0.05). The TWIST1‐expressing cells showed significantly higher MAGEA4 expression compared to control cells. ChIP and luciferase assays results confirmed indirect binding of TWIST1 to the E‐boxes of MAGEA4 promoter sequence and revealed a novel regulatory role of TWIST1 in MAGEA4 upregulation. Conclusion: Since MAGEA4 is a highly expressed oncogene in a variety of malignancies in significant correlation with tumor cell invasiveness and aggressiveness, our finding may help understand one regulatory mechanism of increased expression in tumor cells. © 2016 Wiley Periodicals, Inc.

Negative Regulatory Role of TWIST1 on SNAIL Gene Expression

Epithelial-mesenchymal transition (EMT) is crucial for specific morphogenetic movements during embryonic development as well as pathological processes of tumor cell invasion and metastasis. TWIST and SNAIL play vital roles in both developmental and pathological EMT. Our aim in this study was to investigate the functional correlation between TWIST1 and SNAIL in human ESCC cell line (KYSE-30). The packaging cell line GP293T was cotransfected with either control retroviral pruf-IRES-GFP plasmid or pruf-IRES-GFP-hTWIST1 and pGP plasmid. The KYSE-30 ESCC cells were transduced with produced viral particles and examined with inverted fluorescence microscope. DNA was extracted from transduced KYSE-30 cells and analyzed for copy number of integrated retroviral sequences in the target cell genome. The concentration of retroviral particles was determined by Real-time PCR. After RNA extraction and cDNA synthesis, the mRNA expression of TWIST1 and SNAIL was assessed by comparative real-time PCR amplification. Ectopic expression of TWIST1 in KYSE-30, dramatically reduces SNAIL expression. Retroviral transduction enforced TWIST1 overexpression in GFP-hTWIST1 nearly 9 folds in comparison with GFP control cells, and interestingly, this TWIST1 enforced expression caused a - 7 fold decrease of SNAIL mRNA expression in GFP-hTWIST1 compared to GFP control cells. Inverse correlation of TWIST1 and SNAIL mRNA levels may introduce novel molecular gene expression pathway controlling EMT process during ESCC aggressiveness and tumorigenesis. Consequently, these data extend the spectrum of biological activities of TWIST1 and propose that therapeutic repression of TWIST1 may be an effective strategy to inhibit cancer cell invasion and metastasis.

Concise Review: Stem Cells and Epithelial-Mesenchymal Transition in Cancer: Biological Implications and Therapeutic Targets

Cancer stem cells (CSCs) constitute a small subpopulation of cancer cells with stem-like properties that are able to self-renew, generate differentiated daughter cells, and give rise to heterogeneous tumor tissue. Tumor heterogeneity is a hallmark of cancer and underlies resistance to anticancer therapies and disease progression. The epithelial-mesenchymal transition (EMT) is a reversible phenomenon that is mediated by EMT-inducing transcription factors (EMT-TFs) and plays an important role in normal organ development, wound healing, and the invasiveness of cancer cells. Recent evidence showing that overexpression of several EMT-TFs is associated with stemness in cancer cells has suggested the existence of a link between EMT and CSCs. In this review, we focus on the roles of CSCs and EMT signaling in driving tumor heterogeneity. A better understanding of the dynamics of both CSCs and EMT-TFs in the generation of tumor heterogeneity may provide a basis for the development of new treatment options for cancer patients. Stem Cells 2016;34:1997-2007.

TWIST1 and BMI1 in Cancer Metastasis and Chemoresistance

Purpose Increasing evidences revealed that cancer cells with the characteristics of epithelial-mesenchymal transition (EMT) or cancer stem cells (CSC) have high ability of progression, invasion, metastasis and chemoresistance. TWIST1 and BMI1 are crucial transcription factors required for EMT and CSC. Both TWIST1 and BMI1 are up-regulated in various cancers and have a positive correlation with poor prognosis. Although recent results showed that the two molecules function in promoting cancer metastasis and chemoresistance respectively, the correlation of TWIST1 and BMI1 is not well understood. Methods In this review, we summarize recent advance in cancer research focus on TWIST1 and BMI1 in cancer metastasis and chemoresistance, and emphasize the possible link between EMT and CSC. Results Further investigation of TWIST1 and BMI1 cooperately promote CSC proliferation due to EMT-associated effect will help to understand the mechanism of tumor cells metastasis and chemoresistance. Conclusions TWIST1 and BMI1 in cancer cells will be effective targets for treating chemoresistant metastatic lesions.

Osteopontin-A Master Regulator of Epithelial-Mesenchymal Transition

Osteopontin (OPN) plays an important functional role in both physiologic and pathologic states. OPN is implicated in the progression of fibrosis, cancer, and metastatic disease in several organ systems. The epithelial-mesenchymal transition (EMT), first described in embryology, is increasingly being recognized as a significant contributor to fibrotic phenotypes and tumor progression. Several well-established transcription factors regulate EMT and are conserved across tissue types and organ systems, including TWIST, zinc finger E-box-binding homeobox (ZEB), and SNAIL-family members. Recent literature points to an important relationship between OPN and EMT, implicating OPN as a key regulatory component of EMT programs. In this review, OPN’s interplay with traditional EMT activators, both directly and indirectly, will be discussed. Also, OPN’s ability to restructure the tissue and tumor microenvironment to indirectly modify EMT will be reviewed. Together, these diverse pathways demonstrate that OPN is able to modulate EMT and provide new targets for directing therapeutics.

Significance of twist and iNOS expression in human breast carcinoma

Twist is a basic helix-loop-helix transcription factor family normally expressed during embryonic development and apparently activated in variety of tumours. Overexpression of twist is correlated with uncontrolled cell proliferation, differentiation, invasion and metastasis. Twist expression is associated with oestrogen receptor (ER); however, the molecular mechanism behind involvement of twist in progression of breast cancer is still unclear. Nitric oxide synthases (NOSs) which cause damage to the cellular DNA are also shown to be involved in cancer progression. The present study involves total number of n = 85 breast biopsies, which include 19 non-cancer and 66 cancerous lesions. We analysed twist, iNOS and ER expression pattern in human breast carcinomas by RT-PCR and also analysed twist cellular localisation by immunohistochemical analysis. iNOS expression pattern was correlated with different stages of breast carcinoma. Twist expression was significantly increased in cancer lesions when compared to the non-cancer. The breast cancer lesions positive to ER showed positivity to twist (72%) as well. The higher stages of cancer lesions showed a significant expression of twist localised in cytoplasm of the cancer cells. Collectively these data indicate that up-regulation of twist is correlated with the ER presenting breast cancer, and iNOS expression was positively correlated with tumour-node metastasis (TNM) staging of breast cancer. These findings suggest that expression of twist and iNOS may have a functional role in cancer progression.

Contribution of EVX1 in Aggressiveness of Esophageal Squamous Cell Carcinoma

Homeobox genes play an overruling role in the regional cell fate determination during development. EVX1 is known as a new target gene of BMP signaling pathway, a group of morphogens which are making the largest subset within the transformation growth factor beta (TGF-β) superfamily. In this study, we aimed to enlighten the expression level of EVX1 in esophageal squamous cell carcinoma (ESCC) and to disclose its apparent roles in maintenance and progression of the disease. The expression level of EVX1 was analyzed in fresh tumoral tissues in comparison with distant tumor-free tissues of 50 ESCC patients using relative comparative real-time PCR. The importance of EVX1 in development and cancer was also reviewed. EVX1 was underexpressed in 70% of tumor samples. There was a significant correlation between down-regulation of EVX1 and lymph node metastasis of tumor cells (p = 0.027). Furthermore, EVX1 underexpression was significantly correlated with depth of tumor cell invasion (P = 0.037). To the best of our knowledge, this is the first report highlighting EVX1 expression in ESCC to date. The clinicopathological relevance of EVX1 mRNA expression in ESCC targeted this gene as a new independent molecular marker for advanced tumor, which determine the characteristics and behavior of aggressive ESCC.

Quercetin Suppresses Twist to Induce Apoptosis in MCF-7 Breast Cancer Cells

Quercetin is a dietary flavonoid which exerts anti-oxidant, anti-inflammatory and anti-cancer properties. In this study, we investigated the anti-proliferative effect of quercetin in two breast cancer cell lines (MCF-7 and MDA-MB-231), which differed in hormone receptor. IC₅₀ value (37μM) of quercetin showed significant cytotoxicity in MCF-7 cells, which was not observed in MDA-MB-231 cells even at 100μM of quercetin treatment. To study the response of cancer cells to quercetin, with respect to different hormone receptors, both the cell lines were treated with a fixed concentration (40μM) of quercetin. MCF-7 cells on quercetin treatment showed more apoptotic cells with G1 phase arrest. In addition, quercetin effectively suppressed the expression of CyclinD1, p21, Twist and phospho p38MAPK, which was not observed in MDA-MB-231 cells. To analyse the molecular mechanism of quercetin in exerting an apoptotic effect in MCF-7 cells, Twist was over-expressed and the molecular changes were observed after quercetin administration. Quercetin effectively regulated the expression of Twist, in turn p16 and p21 which induced apoptosis in MCF-7 cells. In conclusion, quercetin induces apoptosis in breast cancer cells through suppression of Twist via p38MAPK pathway.

Different levels of Twist1 regulate skin tumor initiation, stemness, and progression

Twist1 promotes epithelial-to-mesenchymal transition (EMT), invasion, metastasis, and cancer stem cell (CSC) properties. However, it remains unclear whether Twist1 is also required for tumor initiation and whether Twist1-induced cancer stemness and EMT are functionally linked. Using a conditional deletion of Twist1 at different stages of skin carcinogenesis, we show that Twist1 is required for skin tumor initiation and progression in a gene-dosage-dependent manner. Moreover, conditional ablation of Twist1 in benign tumors leads to increased apoptosis, reduced cell proliferation, and defective tumor maintenance and propagation independently of its EMT-inducing abilities. Concomitant deletion of Twist1 and p53 rescues the apoptotic response, but not the cell proliferation and propagation defects. These results reveal that Twist1 is required for tumor initiation and maintenance in a p53-dependent and -independent manner. Importantly, our findings also indicate that tumor stemness and EMT can be regulated by distinct mechanisms.

TWIST and ovarian cancer stem cells: implications for chemoresistance and metastasis

The transcription factor TWIST1 is a highly evolutionally conserved basic Helix-Loop-Helix (bHLH) transcription factor that functions as a master regulator of gastrulation and mesodermal development. Although TWIST1 was initially associated with embryo development, an increasing number of studies have shown TWIST1 role in the regulation of tissue homeostasis, primarily as a regulator of inflammation. More recently, TWIST1 has been found to be involved in the process of tumor metastasis through the regulation of Epithelial Mesenchymal Transition (EMT). The objective of this review is to examine the normal functions of TWIST1 and its role in tumor development, with a particular focus on ovarian cancer. We discuss the potential role of TWIST1 in the context of ovarian cancer stem cells and its influence in the process of tumor formation.

Co-Expression of TWIST1 and ZEB2 in Oral Squamous Cell Carcinoma Is Associated with Poor Survival

Oral squamous cell carcinoma (OSCC) is an aggressive disease accounting for more than 260,000 cancer cases diagnosed and 128,000 deaths worldwide. A large majority of cancer deaths result from cancers that have metastasized beyond the primary tumor. The relationship between genetic changes and clinical outcome can reflect the biological events that promote cancer's aggressive behavior, and these can serve as molecular markers for improved patient management and survival. To this end, epithelial-mesenchymal transition (EMT) is a major process that promotes tumor invasion and metastasis, making EMT-related proteins attractive diagnostic biomarkers and therapeutic targets. In this study, we used immunohistochemistry to study the expression of a panel of transcription factors (TWIST1, SNAI1/2, ZEB1 and ZEB2) and other genes intimately related to EMT (CDH1 and LAMC2) at the invasive tumor front of OSCC tissues. The association between the expression of these proteins and clinico-pathological parameters were examined with Pearson Chi-square and correlation with survival was analyzed using Kaplan Meier analysis. Our results demonstrate that there was a significant differential expression of CDH1, LAMC2, SNAI1/2 and TWIST1 between OSCC and normal oral mucosa (NOM). Specifically, CDH1 loss was significantly associated with Broder's grading, while diffused LAMC2 was similarly associated with non-cohesive pattern of invasion. Notably, co-expression of TWIST1 and ZEB2 in OSCC was significantly associated with poorer overall survival, particularly in patients without detectable lymph node metastasis. This study demonstrates that EMT-related proteins are differentially expressed in OSCC and that the co-expression of TWIST1 and ZEB2 could be of clinical value in identifying patients with poor survival for appropriate patient management.

Decreased mRNA and protein expression of TWIST1 in myocardial tissue of fetuses with ventricular septal defects

Ventricular septal defect (VSD) is the most common type of congenital heart disease (CHD). The single gene mutations or absences that contribute to VSD development are well established; however, the aim of the present study was to measure gene expression variation between VSDs and normal fetal myocardial tissue. TWIST1, an important tumor biomarker, is a basic helix-loop-helix transcription factor that regulates cell proliferation, migration and differentiation in embryonic development and transformed tumor cells. Although growing evidence demonstrates that TWIST1 participates in a variety of human neoplastic diseases, the role of TWIST1 in VSD has remained elusive. Twenty-six VSD fetal myocardial tissue samples and 12 normal samples at matched gestational weeks (22-28 weeks) were included in the present study. Using reverse transcription quantitative polymerase chain reaction (PCR) and real-time PCR, it was demonstrated that TWIST1 mRNA was reduced by almost two-fold in the VSD samples compared with the normal samples. Western blot analysis also revealed that TWIST1 expression was decreased by ~three-fold (P=0.001) in the VSD samples compared with that in the normal samples. Of note, five complete ventricular (also called functionally univentricular or single ventricular) septal ageneses were identified among the specimens. For the five complete ventricular septal agenesis samples, similar results to those for other VSD fetal myocardial tissues were obtained. In conclusion, the results of the present study showed that TWIST1 mRNA and protein levels were reduced in VSDs. The present study was the first, to the best of our knowledge, to report that TWIST1 is not only a tumor biomarker, but may also be involved in the pathogenesis of VSD.

PRMT1 Is a Novel Regulator of Epithelial-Mesenchymal-Transition in Non-small Cell Lung Cancer

Protein arginine methyl transferase 1 (PRMT1) was shown to be up-regulated in cancers and important for cancer cell proliferation. However, the role of PRMT1 in lung cancer progression and metastasis remains incompletely understood. In the present study, we show that PRMT1 is an important regulator of epithelial-mesenchymal transition (EMT), cancer cell migration, and invasion, which are essential processes during cancer progression, and metastasis. Additionally, we have identified Twist1, a basic helix-loop-helix transcription factor and a well-known E-cadherin repressor, as a novel PRMT1 substrate. Taken together, we show that PRMT1 is a novel regulator of EMT and arginine 34 (Arg-34) methylation of Twist1 as a unique "methyl arginine mark" for active E-cadherin repression. Therefore, targeting PRMT1-mediated Twist1 methylation might represent a novel strategy for developing new anti-invasive/anti-metastatic drugs. Moreover, methylated Twist1 (Arg-34), as such, could also emerge as a potential important biomarker for lung cancer.

A cross sectional study of p504s, CD133, and Twist expression in the esophageal metaplasia dysplasia adenocarcinoma sequence

The incidence of esophageal adenocarcinoma has increased dramatically over recent years and Barrett's esophagus is considered the most established risk factor for its development. Endoscopic surveillance of Barrett's esophagus is therefore recommended but hinges on histological interpretation of randomly taken biopsies which is poorly reproducible. The use of biomarkers presents an opportunity to improve our ability to risk-stratify these patients.We examined three biomarkers namely p504s, CD133, and Twist in the setting of Barrett's esophagus, low-grade dysplasia, and esophageal adenocarcinoma to evaluate differential expression between benign, dysplastic, and malignant Barrett's tissue in an exploratory cross-sectional study. Twenty-five cases each of Barrett's esophagus, low-grade dysplasia, and esophageal adenocarcinoma were included along-with 25 cases of esophagectomy resections for Barrett's adenocarcinoma. The biomarkers were immunostained on automated Ventana(®) immunostainer. The biopsies were assessed for biomarker expression by two independent observers. Granular cytoplasmic staining of p504s was observed in dysplastic Barrett's biopsies and esophageal adenocarcinoma but not in Barrett's esophagus. Apical and membranous CD133 expression was also observed in dysplastic Barrett's and esophageal adenocarcinoma. Nuclear Twist expression was seen predominantly in stromal cells. There was increased p504s expression in dysplastic Barrett's esophagus and esophageal adenocarcinoma compared with controls. CD133 expression was detected for the first time in esophageal adenocarcinoma and dysplastic Barrett's esophagus. Twist expression was not convincing enough to be labeled as Barrett's biomarker. p504s and CD133 have the potential to differentiate benign from malignant Barrett's tissue in this exploratory study. Their validity should be established in prospective longitudinal studies.

RNA-based TWIST1 inhibition via dendrimer complex to reduce breast cancer cell metastasis

Breast cancer is the leading cause of cancer-related deaths among women in the United States, and survival rates are lower for patients with metastases and/or triple-negative breast cancer (TNBC; ER, PR, and Her2 negative). Understanding the mechanisms of cancer metastasis is therefore crucial to identify new therapeutic targets and develop novel treatments to improve patient outcomes. A potential target is the TWIST1 transcription factor, which is often overexpressed in aggressive breast cancers and is a master regulator of cellular migration through epithelial-mesenchymal transition (EMT). Here, we demonstrate an siRNA-based TWIST1 silencing approach with delivery using a modified poly(amidoamine) (PAMAM) dendrimer. Our results demonstrate that SUM1315 TNBC cells efficiently take up PAMAM-siRNA complexes, leading to significant knockdown of TWIST1 and EMT-related target genes. Knockdown lasts up to one week after transfection and leads to a reduction in migration and invasion, as determined by wound healing and transwell assays. Furthermore, we demonstrate that PAMAM dendrimers can deliver siRNA to xenograft orthotopic tumors and siRNA remains in the tumor for at least four hours after treatment. These results suggest that further development of dendrimer-based delivery of siRNA for TWIST1 silencing may lead to a valuable adjunctive therapy for patients with TNBC.

SOX5 promotes epithelial-mesenchymal transition and cell invasion via regulation of Twist1 in hepatocellular carcinoma

The transcription factor sex determining region Y-box protein 5 (SOX5) plays important roles in various types of cancers. However, the expression and function of SOX5 in hepatocellular carcinoma (HCC) have not been elucidated. Here, we found that SOX5 is significantly up-regulated in HCC tissues and cell lines. Gain- and loss-of-function studies demonstrated that SOX5 promoted HCC cell migration and invasion. In addition, we revealed that SOX5 is linked to epithelial-mesenchymal transition (EMT) by regulation of Twist1. Our results indicate for the first time that SOX5 is a novel regulator of EMT in HCC and may be a potential therapeutic target for HCC metastasis.

Twist1 correlates with poor differentiation and progression in gastric adenocarcinoma via elevation of FGFR2 expression

AIM: To explore the correlation between Twist-related protein (Twist)1, fibroblast growth factor receptor (FGFR)2 and gastric adenocarcinoma differentiation and progression.

METHODS: We evaluated Twist1 and FGFR2 in 52 gastric adenocarcinoma samples by immunohistochemistry and quantitative real time polymerase chain reaction, and analyzed the correlation between Twist1, FGFR2 and cancer differentiation. We also detected Twist1 and FGFR2 expression in gastric adenocarcinoma cell lines, and evaluated Twist1 influence on FGFR2 expression. In addition, we studied the role of FGFR2 in Twist1-promoted cancer progression, including proliferation, invasion and epithelial-mesenchymal transition (EMT).

RESULTS: Twist1 and FGFR2 were detected in almost all the gastric adenocarcinoma samples. Twist1 (P = 0.0213) and FGFR2 (P = 0.0310) mRNA levels had a significant association with gastric adenocarcinoma differentiation. Moreover, Twist1 and FGFR2 expression in poorly differentiated cells (SNU-1 and SNU-16) was notably higher than in well-differentiated cells (MKN-7 and MKN-28). In poorly differentiated gastric adenocarcinomas, FGFR2 mRNA level was significantly positively correlated with Twist1 mRNA level (P = 0.004). Twist1 was proved to promote FGFR2 by regulating Twist1 expression by knockdown and overexpression. Additionally, Twist1 could induce proliferation, invasion and EMT in gastric cancer; of these, FGFR2 was required for invasion and EMT, rather than proliferation.

CONCLUSION: Twist1 and FGFR2 are highly associated with differentiation of gastric adenocarcinoma; Twist1 can facilitate invasion and EMT in gastric adenocarcinoma via promotion of FGFR2 expression.

Epithelial to mesenchymal transition inducing transcription factors and metastatic cancer

The epithelial to mesenchymal transition (EMT) is an important step for the developmental process. Recent evidences support that EMT allows the tumor cells to acquire invasive properties and to develop metastatic growth characteristics. Some of the transcription factors, which are actively involved in EMT process, have a significant role in the EMT-metastasis linkage. A number of studies have reported that EMT-inducing transcription factors (EMT-TFs), such as Twist, Snail, Slug, and Zeb, are directly or indirectly involved in cancer cell metastasis through a different signaling cascades, including the Akt, signal transducer and activator of transcription 3 (STAT3), mitogen-activated protein kinase (MAPK) and Wnt pathways, with the ultimate consequence of the downregulation of E-cadherin and upregulation of metastatic proteins, such as N-cadherin, vimentin, matrix metalloproteinase (MMP)-2, etc. This review summarizes the update information on the association of EMT-TFs with cancer metastasis and the possible cancer therapeutics via targeting the EMT-TFs.

Wogonin suppresses human alveolar adenocarcinoma cell A549 migration in inflammatory microenvironment by modulating the IL-6/STAT3 signaling pathway

Increasing evidence from various clinical and experimental studies has demonstrated that the inflammatory microenvironment facilitates tumor metastasis. Clinically, it will be a promising choice to suppress tumor metastasis by targeting inflammatory microenvironment. Our previous studies have demonstrated that wogonin (a bioflavonoid isolated from the traditional Chinese medicine of Huang-Qin) possesses the anti-metastatic and anti-inflammatory activity, but we have little idea about its efficacy on inflammatory-induced tumor metastasis and the mechanism underlying it. In this study, we focused on epithelial mesenchymal transition (EMT), the first step of tumor metastasis, to evaluate the effects of wogonin on tumor metastasis in inflammatory microenvironment. We found that wogonin inhibited THP-1 conditioned-medium- (CM-) and IL-6-induced EMT by inactivating STAT3 signal. And in wogonin-treated A549 cells which pretreated with THP-1 CM or IL-6, the expression level of E-cadherin, an EMT negative biomarker, increased while that of N-cadherin, Vimentin, and EMT-related transcription factors including Snail and Twist decreased. Moreover, wogonin inhibited IL-6-induced phosphorylation of STAT3, prevented p-STAT3 dimer translocation into the nucleus, and suppressed the DNA-binding activity of p-STAT3. Interestingly, similar results were obtained in the tumor xenografts mice, including downregulation of p-STAT3, N-cadherin, and Vimentin while up-regulation of E-cadherin. Wogonin also inhibit the metastasis of A549 cells in vivo. Taken all data together, we concluded that wogonin suppresses tumor cells migration in inflammatory microenvironment by inactivating STAT3 signal.

miR-300 inhibits epithelial to mesenchymal transition and metastasis by targeting Twist in human epithelial cancer

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) is a key step of the progression of tumor cell metastasis. Recent work has demonstrated some miRNAs play critical roles in EMT. In this study, we focused on the roles of miR-300 in regulating EMT.

METHODS

The expression levels of miR-300 were examined in epithelial carcinoma cells that underwent an EMT using quantitative reverse transcription-PCR. The role of miR-300 in EMT was investigated by transfection of the miR-300 mimic or inhibitor in natural epithelial-mesenchymal phenotype cell line pairs and in transforming growth factor (TGF) beta-induced EMT cell models. A luciferase reporter assay and a rescue experiment were conducted to confirm the target gene of miR-300. The efficacy of miR-300 against tumor invasion and metastasis was evaluated both in vitro and in vivo. Correlation analysis between miR-300 expression and the expression levels of its target gene, as well as tumor metastasis was performed in specimens from patients with head and neck squamous cell carcinoma (HNSCC).

RESULTS

MiR-300 was found down-regulated in the HNSCC cells and breast cancer cells that underwent EMT. Ectopic expression of miR-300 effectively blocked TGF-beta-induced EMT and reversed the phenotype of EMT in HN-12 and MDA-MB-231 cells, but inhibition of miR-300 in the epithelial phenotype cells, HN-4 and MCF-7 cells, could induce EMT. The luciferase reporter assay and the rescue assay results showed that miR-300 directly targets the 3'UTR of Twist. Enforced miR-300 expression suppressed cell invasion in vitro and experimental metastasis in vivo. Clinically, miR-300 expression was found inversely correlated with Twist expression and reduced miR-300 was associated with metastasis in patient specimens.

CONCLUSIONS

Down-regulation of miR-300 is required for EMT initiation and maintenance. MiR-300 may negatively regulate EMT by direct targeting Twist and therefore inhibit cancer cell invasion and metastasis, which implicates miR-300 as an attractive candidate for cancer therapy.

Twist and miR-34a are involved in the generation of tumor-educated myeloid-derived suppressor cells

Tumors can induce the generation and accumulation of immunosuppressive cells such as myeloid-derived suppressor cells in the tumor microenvironment, contributing to tumor immunological escapes. Many studies have demonstrated that multiple factors could induce myeloid precursor cells into myeloid-derived suppressor cells, not dendritic cells. In our study, we found that tumor supernatants could induce the generation of myeloid-derived suppressor cells by disturbing the development of dendritic cells. Twist and miR-34a may regulate the effect of tumor cells inducing myeloid-derived suppressor cells via TGF-β and/or IL-10.

Twist: a molecular target in cancer therapeutics

Twist, the basic helix-loop-helix transcription factor, is involved in the process of epithelial to mesenchymal transitions (EMTs), which play an essential role in cancer metastasis. Overexpression of Twist or its promoter methylation is a common scenario in metastatic carcinomas. Twist is activated by a variety of signal transduction pathways, including Akt, signal transducer and activator of transcription 3, mitogen-activated protein kinase, Ras, and Wnt signaling. Activated Twist upregulates N-cadherin and downregulates E-cadherin, which are the hallmarks of EMT. Moreover, Twist plays an important role in some physiological processes involved in metastasis, like angiogenesis, invadopodia, extravasation, and chromosomal instability. Twist also protects cancer cells from apoptotic cell death. In addition, Twist is responsible for the stemness of cancer cells and the generation of drug resistance. Recently, targeting Twist has gained significant interests in cancer therapeutics. The inactivation of Twist by small RNA technology or chemotherapeutic approach has been proved successful. Moreover, several inhibitors which are antagonistic to the upstream or downstream molecules of Twist signaling pathways have also been identified. Development of potential treatment strategies by targeting Twist has a great promise in cancer therapeutics.

Biomarkers for predicting future metastasis of human gastrointestinal tumors

The recent advances in surgery and radiation therapy have significantly improved the prognosis of patients with primary cancer, and the major challenge of cancer treatment now is metastatic disease development. The 5-year survival rate of cancer patients who have distant metastasis at diagnosis is extremely low, suggesting that prediction and early detection of metastasis would definitely improve their prognosis because suitable patient therapeutic management and treatment strategy can be provided. Cancer cells from a primary site give rise to a metastatic tumor via a number of steps which require the involvement and altered expression of many regulators. These regulators may serve as biomarkers for predicting metastasis. Over the past few years, numerous regulators have been found correlating with metastasis. In this review, we summarize the findings of a number of potential biomarkers that are involved in cadherin-catenin interaction, integrin signaling, PI3K/Akt/mTOR signaling and cancer stem cell identification in gastrointestinal cancers. We will also discuss how certain biomarkers are associated with the tumor microenvironment that favors cancer metastasis.

Inducible knockout of Twist1 in young and adult mice prolongs hair growth cycle and has mild effects on general health, supporting Twist1 as a preferential cancer target

Twist1 promotes epithelial-mesenchymal transition, invasion, metastasis, stemness, and chemotherapy resistance in cancer cells and thus is a potential target for cancer therapy. However, Twist1-null mice are embryonic lethal, and people with one Twist1 germline mutant allele develop Saethre-Chotzen syndrome; it is questionable whether Twist1 can be targeted in patients without severe adverse effects. We found that Twist1 is expressed in several tissues, including fibroblasts of the mammary glands and dermal papilla cells of the hair follicles. We developed a tamoxifen-inducible Twist1 knockout mouse model; Twist1 knockout in 6-week-old female mice did not affect mammary gland morphogenesis and function during pregnancy and lactation. In both males and females, the knockout did not influence body weight gain, heart rate, or total lean and fat components. The knockout also did not alter blood pressure in males, although it slightly reduced blood pressure in females. Although Twist1 is not cyclically expressed in dermal papilla cells, knockout of Twist1 at postnatal day 13 (when hair follicles have developed) drastically extended the anagen phase and accelerated hair growth. These results indicate that Twist1 is not essential for maintaining an overall healthy condition in young and adult mice and that loss of function facilitates hair growth in adulthood, supporting Twist1 as a preferential target for cancer therapy.

Spatiotemporal regulation of epithelial-mesenchymal transition is essential for squamous cell carcinoma metastasis

Epithelial-mesenchymal transition (EMT) is implicated in converting stationary epithelial tumor cells into motile mesenchymal cells during metastasis. However, the involvement of EMT in metastasis is still controversial, due to the lack of a mesenchymal phenotype in human carcinoma metastases. Using a spontaneous squamous cell carcinoma mouse model, we show that activation of the EMT-inducing transcription factor Twist1 is sufficient to promote carcinoma cells to undergo EMT and disseminate into blood circulation. Importantly, in distant sites, turning off Twist1 to allow reversion of EMT is essential for disseminated tumor cells to proliferate and form metastases. Our study demonstrates in vivo the requirement of "reversible EMT" in tumor metastasis and may resolve the controversy on the importance of EMT in carcinoma metastasis.

Linkage between Twist1 and Bmi1: molecular mechanism of cancer metastasis/stemness and clinical implications

Cancer metastasis is the major cause of cancer-related death despite significant improvements in multimodal cancer therapy. Epithelial-mesenchymal transition (EMT), a major mechanism of cancer metastasis, is a process that generates cells with stem cell-like properties (cancer stemness). Cancer stemness is a concept that describes a minor population of cells (cancer stem cells) residing within a tumour that are able to self-renew and are resistant to conventional therapy. The mechanisms delineating the generation of cancer stemness and its connection to cancer metastasis remain largely unknown. Twist1 is an EMT regulator and increased Twist1 expression, which has prognostic significance in various human cancers, has been widely reported. Bmi1 is a critical component of polycomb repressive complex (PRC) 1, which maintains self-renewal and stemness. Bmi1 is frequently overexpressed in different types of human cancers and can induce drug resistance (Table 2). Recent studies have shown that Twist1 directly activates Bmi1 expression and that these two molecules function together to mediate cancer stemness and EMT. These results present a unique mechanism of EMT-induced cancer metastasis and stemness. Further investigation of the mechanisms of EMT-mediated cancer metastasis and stemness will contribute to the management and treatment of metastatic cancers.

Expression of TWIST1, Snail, Slug, and NF-κB and methylation of the TWIST1 promoter in mammary phyllodes tumor

TWIST1, Slug, Snail, SIP1, and NF-κB are overexpressed in various tumors and associated with metastasis and poor prognosis. In this study, we examined their potential roles in phyllodes tumor (PT). The expression of TWIST1, Snail, Slug, SIP1, and NF-κB in benign (n = 103), borderline (n = 38), and malignant (n = 38) PTs was examined by immunostaining. The methylation status of the TWIST1 promoter was analyzed by methylation-specific PCR. We detected high expression levels of TWIST1 in 47.4 % of borderline/malignant PTs and 31.1 % of benign PTs, Slug in 64 % of borderline/malignant PTs and 62.1 % of benign PTs, epithelial SIP1 in 75.0 % of borderline/malignant PTs and 86.3 % of benign PTs, stromal SIP1 in 35.5 % of borderline/malignant PTs and 22.3 % of benign PTs, and NF-κB in 63.2 % of borderline/malignant PTs and 52.4 % of benign PTs. Snail expression was detected in all cases. A high expression of TWIST1 (p = 0.026) and TWIST1 promoter methylation (p = 0.000) were significantly more frequent in borderline/malignant PTs than in benign PTs. Moreover, a high expression of at least four of the five antibodies was more commonly observed in borderline/malignant PTs than in benign PTs (p = 0.026). However, no relationship was found between the expression of TWIST1 or the other proteins examined and the clinical outcome. Our results suggest that a high expression of TWIST1 and related proteins plays a pivotal role in the malignant progression of PT.

EMT-activating transcription factors in cancer: beyond EMT and tumor invasiveness

Cancer is a complex multistep process involving genetic and epigenetic changes that eventually result in the activation of oncogenic pathways and/or inactivation of tumor suppressor signals. During cancer progression, cancer cells acquire a number of hallmarks that promote tumor growth and invasion. A crucial mechanism by which carcinoma cells enhance their invasive capacity is the dissolution of intercellular adhesions and the acquisition of a more motile mesenchymal phenotype as part of an epithelial-to-mesenchymal transition (EMT). Although many transcription factors can trigger it, the full molecular reprogramming occurring during an EMT is mainly orchestrated by three major groups of transcription factors: the ZEB, Snail and Twist families. Upregulated expression of these EMT-activating transcription factors (EMT-ATFs) promotes tumor invasiveness in cell lines and xenograft mice models and has been associated with poor clinical prognosis in human cancers. Evidence accumulated in the last few years indicates that EMT-ATFs also regulate an expanding set of cancer cell capabilities beyond tumor invasion. Thus, EMT-ATFs have been shown to cooperate in oncogenic transformation, regulate cancer cell stemness, override safeguard programs against cancer like apoptosis and senescence, determine resistance to chemotherapy and promote tumor angiogenesis. This article reviews the expanding portfolio of functions played by EMT-ATFs in cancer progression.

Snail promotes lymph node metastasis and Twist enhances tumor deposit formation through epithelial-mesenchymal transition in colorectal cancer

Snail and Twist, transcriptional repressors of E-cadherin as well as inducers of epithelial-mesenchymal transition, play pivotal roles in tumor invasion and metastasis. We investigated the expression of Snail, Twist, and E-cadherin by immunohistochemistry in 193 colorectal cancers, including 79 with positive lymph nodes, 36 with tumor deposits, 39 with both, and 39 with no metastases. Snail was expressed to a greater extent in the group with positive lymph nodes (68.4%), whereas Twist was overexpressed in patients with other metastases (75.0%). Ectopic expression of Snail and Twist correlated with reduced membranous expression of E-cadherin. Importantly, Snail overexpression correlated significantly with lymph node metastasis (P < .0001), whereas Twist up-regulation correlated strongly with other metastases (P < .0001). Multivariate logistic regression analysis showed that Snail was an independent predictor of lymph node metastasis (odds ratio, 4.445; 95% confidence interval, 2.250-8.781; P < .0001), whereas Twist displayed predictive value for metastasis formation (odds ratio, 5.606; 95% confidence interval, 2.829-11.111; P < .0001), suggesting that lymph node and other metastases may follow different signaling pathways. In conclusion, ectopic expression of Snail and Twist contributed to lymph node and disseminated metastasis, respectively, by reducing E-cadherin expression, providing a novel role for Snail and Twist in the progression of colorectal cancer.

Expression and significance of twist, E-cadherin, and N-cadherin in gastrointestinal stromal tumors

BACKGROUND

Twist, a basic helix-loop-helix transcription factor, has been reported to play a key role in the metastatic progression of several types of cancer.

AIMS

To investigate the expression and clinical significance of Twist, E-cadherin, and N-cadherin in gastrointestinal stromal tumors (GISTs).

METHODS

The expression of Twist, E-cadherin, and N-cadherin in GISTs was determined by immunohistochemistry, and their relationship with clinicopathological characteristics was analyzed.

RESULTS

The positive rates of Twist, E-cadherin, and N-cadherin in GISTs were 66.7 % (52/78), 35.9 % (28/78), and 75.6 % (59/78), respectively. Twist was expressed significantly more in GISTs with distant metastasis or local invasion (p < 0.05). Although E-cadherin was expressed significantly less in cases of GISTs with distant metastasis (p < 0.05), expression of N-cadherin did not differ significantly according to clinical and pathological characteristics (p > 0.05). Expression of Twist was correlated positively with E-cadherin (rs = -0.253, p = 0.026) and negatively with N-cadherin (rs = 0.245, p = 0.030).

CONCLUSIONS

Twist was expressed significantly more and E-cadherin significantly less in GISTs with metastasis, and expression of both was closely related to metastasis of GISTs.

Relationship between TWIST expression and epithelial-mesenchymal transition of oesophageal squamous cell carcinoma

We have investigated mRNA and protein expression of TWIST, Vimentin and E-cadherin in ESCC (oesophageal squamous cell carcinoma) and explored their relationship with tumour's infiltration and metastasis. RT-PCR (reverse transcriptase-PCR) was used to evaluate mRNA expression of TWIST, E-cadherin and Vimentin in 40 cases of ESCC. The protein expression of the genes was examined by immunohistochemical staining in each specimen. Expression of TWIST, E-cadherin and Vimentin mRNA and protein with clinicopathologic parameters were analysed. mRNAs of TWIST, Vimentin and E-cadherin were expressed in 75, 55 and 35% respectively of ESCC, i.e. significantly different from that in normal oesophageal mucosa (15, 0 and 85% respectively; P<0.01). In ESCC with LN (lymph node) metastasis, expression of TWIST and Vimentin mRNA, but not E-cadherin mRNA was significantly higher (100 and 83%) than in ESCC without LN metastasis (64 and 43%, P=0.018) respectively. Levels of mRNA expression of the 3 genes followed similar patterns to their above-mentioned frequencies. Protein expression of TWIST, E-cadherin and Vimentin were observed in 70, 35 and 50% respectively of ESCC, which were significantly different from normal mucosa (15, 80 and 0%; P<0.001). In ESCC with LN metastasis, protein expression of TWIST and Vimentin, but not E-cadherin, were significantly higher (100 and 75%) than in ESCC without LN metastasis (61 and 39%). Protein expression of TWIST was positively correlated with Vimentin (r=0.327, P=0.039), but negatively correlated with E-cadherin (r= -0.633, P=0.000). Thus, both mRNAs and proteins of TWIST and Vimentin were significantly overexpressed in ESCC, especially ESCC with LN metastasis. The mRNA and protein of E-cadherin were down-regulated in ESCC. These results suggest potential roles of TWIST as the promoter of tumour invasion and metastasis associated with down-regulation of E-cadherin.