Expression and significance of twist and E-cadherin in ovarian cancer tissues

Claudin-4 Immunoexpression in Urothelial Carcinomas

The involvement of claudins in urothelial carcinogenesis is controversial. In this study, we analyzed Claudin-4 immunoexpression in 50 cases of bladder urothelial carcinomas depending on the main prognostic parameters of the lesions represented by the tumor grade and tumor extension. Claudin-4 immunoexpression scores were significantly higher in high-grade urothelial carcinomas and in tumors with invasion in muscularis propria. The results obtained indicate the involvement of Claudin-4 in the progression of urothelial bladder carcinomas.

Epithelial-mesenchymal interconversions in ovarian cancer: The levels and functions of E-cadherin in intraabdominal dissemination

The metastatic process of ovarian cancer (OC) is almost exclusively defined by direct shedding of tumor cells into the abdominal cavity, followed by clustering into multicellular aggregates and posterior peritoneal anchorage. This process relies on dynamic intercellular interactions which are modified by epithelial- mesenchymal interconversions and, therefore, E-cadherin expression variability. Although widely accepted as a tumor suppressor in many types of cancer, E-cadherin is currently known to have a dynamic expression and a much more complex role in OC. First, high E-cadherin expression is considered a sign of metaplasia in the normal ovarian epithelium, due to its association with epithelial growth factor receptor (EGFR) mediated cell proliferation. Subsequently, it is the decreased expression of E-cadherin that allows the acquisition of a more invasive phenotype, leading to the spread of primary tumor cells into the peritoneal fluid. This downregulation seems to depend on complex regulatory mechanisms, from molecular proteolysis to microenvironment interference and epigenetic regulation. E-cadherin cleavage and its resulting fragments appear to be essential to the process of dissemination and even to the formation of multicellular aggregates. Paradoxically, the maintenance of some E-cadherin expression seems to promote intercellular adhesion, resistance, and survival while decreasing cancer response to chemotherapy. Multiple studies have shown that reversing epithelial-mesenchymal transaction (EMT) and increasing E-cadherin expression prevents OC intraperitoneal dissemination, but findings that simultaneously correlate E-cadherin downregulation to higher chemotherapy sensitivity should not be ignored. Nevertheless, EMT and E-cadherin seem to have a potential interest as therapeutic targets in novel approaches to OC treatment.

Antrodia camphorata inhibits epithelial-to-mesenchymal transition by targeting multiple pathways in triple-negative breast cancers

Antrodia camphorata (AC) exhibits potential for engendering cell-cycle arrest as well as prompting apoptosis and metastasis inhibition in triple-negative breast cancer (TNBC) cells. We performed the current study to explore the anti-epithelial-to-mesenchymal transition (EMT) properties of fermented AC broth in TNBC cells. Our results illustrated that noncytotoxic concentrations of AC (20-60 μg/ml) reversed the morphological changes (fibroblastic-to-epithelial phenotype) as well as the EMT by upregulating the observed E-cadherin expression. Furthermore, we discovered treatment with AC substantially inhibit the Twist expression in human TNBC (MDA-MB-231) cells as well as in those that were transfected with Twist. In addition, we determined AC to decrease the observed Wnt/β-catenin nuclear translocation through a pathway determined to be dependent on GSK3β. Notably, AC treatment consistently inhibited the EMT by downregulating mesenchymal marker proteins like N-cadherin, vimentin, Snail, ZEB-1, and fibronectin; at that same time upregulating epithelial marker proteins like occludin and ZO-1. Bioluminescence imaging that was executed in vivo demonstrated AC substantially suppressed breast cancer metastasis to the lungs. Notably, we found that western blot analysis confirmed that AC decreased lung metastasis as demonstrated by upregulation of E-cadherin expression in biopsied lung tissue. Together with our results support the anti-EMT activity of AC, indicating AC as having the potential for acting as an anticancer agent for the treatment of human TNBC treatment.

Targeting epithelial-mesenchymal transition and cancer stem cells for chemoresistant ovarian cancer

Chemoresistance is the main challenge for the recurrent ovarian cancer therapy and responsible for treatment failure and unfavorable clinical outcome. Understanding mechanisms of chemoresistance in ovarian cancer would help to predict disease progression, develop new therapies and personalize systemic therapy. In the last decade, accumulating evidence demonstrates that epithelial-mesenchymal transition and cancer stem cells play important roles in ovarian cancer chemoresistance and metastasis. Treatment of epithelial-mesenchymal transition and cancer stem cells holds promise for improving current ovarian cancer therapies and prolonging the survival of recurrent ovarian cancer patients in the future. In this review, we focus on the role of epithelial-mesenchymal transition and cancer stem cells in ovarian cancer chemoresistance and explore the therapeutic implications for developing epithelial-mesenchymal transition and cancer stem cells associated therapies for future ovarian cancer treatment.

CXCL11 mediates TWIST1-induced angiogenesis in epithelial ovarian cancer

To investigate the role of TWIST1 in tumor angiogenesis in epithelial ovarian cancer and to identify key molecules involved in angiogenesis. TWIST1 small interfering RNA was transfected into A2780 cells, while a complementary DNA vector was transfected into non-malignant human ovarian surface epithelial cells to generate a TWIST1-overexpressing cell line. To evaluate how this affects angiogenesis, human umbilical vein endothelial cell tube formation assays were performed using the control and transfected cell lines. An antibody-based cytokine array was used to identify the molecules involved in TWIST1-mediated angiogenesis. After knockdown of TWIST1 via transfection of TWIST1 small interfering RNA into A2780 cells, the number of tubes formed by human umbilical vein endothelial cells significantly decreased in a tube formation assay. In a cytokine array, TWIST1 downregulation did not significantly decrease the secretion of the common pro-angiogenic factor, vascular endothelial growth factor, but instead inhibited the expression of the CXC chemokine ligand 11, which was confirmed by both an enzyme-linked immunosorbent assay and western blotting. In contrast, TWIST1 overexpression resulted in increased secretion of CXC chemokine ligand 11. Conversely, CXC chemokine ligand 11 downregulation did not inhibit the expression of TWIST1. Furthermore, the ability of TWIST1-expressing A2780 cells to induce angiogenesis was found to be inhibited after CXC chemokine ligand 11 knockdown in a tube formation assay. TWIST1 plays an important role in angiogenesis in epithelial ovarian cancer and is mediated by a novel pro-angiogenic factor, CXC chemokine ligand 11. Downregulation of CXC chemokine ligand 11 can inhibit tumor angiogenesis, suggesting that anti-CXC chemokine ligand 11 therapy may offer an alternative treatment strategy for TWIST1-positive ovarian cancer.

Twist may be associated with invasion and metastasis of hypoxic NSCLC cells

Hypoxia promotes tumor invasion and metastasis via multiple mechanisms, including epithelial-mesenchymal transition (EMT). Twist, an EMT regulator, has been disclosed to associate with invasion and metastasis as well as poor prognosis of many malignancies. However, it remains undefined whether Twist is involved in invasion and metastasis of hypoxic non-small cell lung cancer (NSCLC). In this study, protein levels of Twist, hypoxia-inducible factor-1α (HIF-1α), and EMT markers (E-cadherin and vimentin) were examined by immunohistochemistry in 76 lung cancer tissues from NSCLC patients. Expression of Twist and its correlation with HIF-1α, E-cadherin, and vimentin were analyzed. Small interfering RNA (siRNA) against Twist was used to knockdown Twist expression in hypoxic NSCLC cells, A549 and NCI-H460. Cellular invasion and protein levels of Twist, E-cadherin, and vimentin were evaluated by matrigel invasion assay and Western blot, respectively. Our results showed that in clinical samples, there was a significant association between Twist expression and differentiation degree, lymph node metastasis, and TNM stage. Correlation analysis demonstrated that expression of Twist was negatively correlated with E-cadherin expression, but positively associated with HIF-1α and vimentin expression. In cultured NSCLC cells, Twist messenger RNA (mRNA) and protein levels were upregulated under hypoxia, while knockdown of Twist suppressed potentiated invasion and expression of mesenchymal marker vimentin induced by hypoxia. Protein level of increased epithelial marker E-cadherin was shown along with Twist downregulation. These findings suggest that Twist promoting hypoxic invasion and metastasis of NSCLC may be associated with altered expression of EMT markers. Inhibition of Twist may be of therapeutic significance.

MiR-548c impairs migration and invasion of endometrial and ovarian cancer cells via downregulation of Twist

BACKGROUND

MicroRNAs (miRNAs) are a class of small non-coding RNAs, which post-transcriptionally repress the expression of genes involved in cancer initiation and progression. Although some miRNAs that target many signaling pathways (also called universe miRNAs) are supposed to play a global role in diverse human tumors, their regulatory functions in gynecological cancers remain largely unknown. We investigated the biological role and underlying mechanism of miR-548c (one universe miRNA) in endometrial and ovarian cancer.

METHODS

The effects of miR-548c overexpression on cell proliferation, migration and invasion were studied in endometrial and ovarian cancer cells. TWIST1 (Twist) was identified as a direct miR-548c target by western blot analysis and luciferase activity assay. The expression of miR-548c and Twist were examined by qRT-PCR in endometrial and ovarian cancer tissues.

RESULTS

Here, we report that miR-548c is down-regulated in endometrial and ovarian cancer tissues when compared to normal tissues, and our meta-analysis reveal that decreased miR-548c expression correlates with poor prognosis in endometrial cancer patients. We show that in endometrial and ovarian cancer cells, ectopic expression of miR-548c significantly inhibits whereas knockdown of miR-548c dramatically induces cancer cell proliferation, migration and invasion. By using luciferase reporter assay, we demonstrate that Twist, a known oncogene in endometrial and ovarian cancers, is a direct target of miR-548c. Furthermore, the expression of Twist partially abrogates the tumor suppressive effects of miR-548c on cell migration and invasion.

CONCLUSION

These findings suggest that miR-548c directly downregulates Twist, and provide a novel mechanism for Twist upregulation in both endometrial and ovarian cancers. The use of miR-548c may hold therapeutic potential for the treatment of Twist-overexpressing tumors.

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.

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.

BMI1 and TWIST1 downregulated mRNA expression in basal cell carcinoma

BACKGROUND

BMI1, TWIST1 and SNAI2/SLUG have been implicated in aggressive behavior of squamous cell carcinoma (SCC) and melanoma and BMI1 expression could identify subtypes of Merkel cell carcinoma (MCC). However, BMI1, TWIST1 and SNAI2 expression levels in basal cell carcinomas (BCCs) have not been elucidated. We hypothesized BCC could be a good model system to decipher mechanisms which inhibit processes that drive tumor metastasis. The aim of this study was to examine the mRNA expression level of BMI1, TWIST1, and SNAI2 in BCCs.

MATERIALS AND METHODS

Thirty-five fresh non-metastatic BCC tissue samples and seven fresh normal skin tissue samples were evaluated by real-time RT-PCR.

RESULTS

BMI1 and TWIST1 demonstrated marked down-regulation (p<0.00l, p=0.00l respectively), but SNAI2 showed no significant change (p=0.12).

CONCLUSIONS

Previous literature has clearly demonstrated a positive association between BMI1 and TWIST1 expression and metastatic BCC, aggressive SCC and melanoma. Here, we demonstrated a negative association between BMI1 and TWIST1 mRNA expression level and BCC.

Silencing of COX-2 by RNAi modulates epithelial-mesenchymal transition in breast cancer cells partially dependent on the PGE2 cascade

In order to prove whether downregulation of COX-2 (Cyclooxygenase-2) could modulate the epithelial- mesenchymal transition (EMT) of breast cancer, celecoxib and siRNA were respectively used to inhibit COX-2 function and expression in MDA-MB-231 cells. The EMT reversal effect in the RNAi treated group was better than that of the celecoxib group while there were no obvious differences in the medium PGE2 levels between the two groups. The results show that COX-2 pathways may contribute considerably to EMT of breast cancer cells, partially dependent on the PGE2 cascade. Akt2, ZEB2 and Snail were measured to clarify the underlying mechanisms of COX-2 on EMT; COX-2 may modulate EMT of breast cancer by regulating these factors. This finding may be helpful to elucidate the mechanisms of selective COX-2 inhibitor action in EMT modulation in breast cancer.

Expression of transcription factor FOXC2 in cervical cancer and effects of silencing on cervical cancer cell proliferation

OBJECTIVE

Forkhead box C2 (FOXC2) is a member of the winged helix/forkhead box (Fox) family of transcription factors. It has been suggested to regulate tumor vasculature, growth, invasion and metastasis, although it has not been studied in cervical cancer. Here, we analyzed FOXC2 expression in cervical tissues corresponding to different stages of cervical cancer development and examined its correlation with clinicopathological characteristics. In addition, we examined the effects of targeting FOXC2 on the biological behavior of human cervical cancer cells.

METHODS

The expression of FOXC2 in normal human cervix, CIN I-III and cervical cancer was examined by immunohistochemistry and compared among the three groups and between cervical cancers with different pathological subtypes. Endogenous expression of FOXC2 was transiently knocked down in human Hela and SiHa cervical cells by siRNA, and cell viability and migration were examined by scratch and CCK8 assays, respectively.

RESULTS

In normal cervical tissue the frequency of positive staining was 25% (10/40 cases), with a staining intensity (PI) of 0.297 ± 0.520, in CIN was 65% (26/40 cases), with a PI of 3.00 ± 3.29, and in cancer was 91.8% (68/74 cases), with a PI of 5.568 ± 3.449. The frequency was 100% in adenocarcinoma (5/5 cases) and 91.3% in SCCs (63/69 cases). The FOXC2 positive expression rate was 88.5% in patients with cervical SCC stage I and 100% in stage II, showing significant differences compared with normal cervix and CIN. With age, pathologic differentiation degree and tumor size, FOXC2 expression showed no significant variation. On transient transfection of Hela and SiHa cells, FOXC2-siRNA inhibition rates were 76.2% and 75.7%; CCK8 results showed reduced proliferation and relative migration (in Hela cells from 64.5 ± 3.16 to 49.5 ± 9.24 and in SiHa cells from 60.1 ± 3.05 to 44.3 ± 3.98) (P < 0.05).

CONCLUSION

FOXC2 gene expression increases with malignancy, especially with blood vessel hyperplasia and invasion degree. Targeted silencing was associated with reduced cell proliferation as well as invasion potential.

The effect and mechanism of CXCR4 silencing on metastasis suppression of human glioma U87 cell line

Tumor metastasis is the major cause of treatment failure and poor prognosis of glioma. Inhibiting metastasis has become an important therapeutic strategy for glioma treatment. CXCR4 has been proved to play an important role in the occurrence and development of tumors. In order to illustrate the effect of CXCR4 on glioma metastasis, we investigated the role of CXCR4 in U87 cells metastasis based on the CXCR4 silencing tumor cells. In this study, we found that CXCR4 silencing could suppress U87 cells invasion and adhesion potential, production of TGF-β1, IL-6, and IL-8, and blocked the G0/G1 phase of the cell cycle. We also found that CXCR4 silencing could up-regulate the mRNA and protein expression of p53, p21, and E-cadherin, and down-regulate the mRNA and protein expression of CD44 and MMP-2/-9. Meanwhile, CXCR4 silencing could decrease the phosphorylation of p-AKT and transcription activity of NF-κB promoter, and increased the phosphorylation of PTEN. The results provided a new research basis for the further study of CXCR4 gene, the screening of human glioma, as well as the target treatment for glioma and its prognosis.