Twist Family bHLH Transcription Factor Research Articles

A Case Study of a High-Grade Serous Carcinoma of the Fallopian Tube Transformed into Carcinosarcoma at the Site of Peritoneal Dissemination With Immunohistological Evidence of an Epithelial-Mesenchymal Transition.

We report a patient in whom a primary high-grade serous carcinoma (HGSC) of the fallopian tube transformed into a carcinosarcoma at the site of peritoneal dissemination, and immunohistological analysis suggested the involvement of an epithelial-mesenchymal transition (EMT). The patient, a 70-year-old woman, had an abdominal mass palpated on admission, and a laparotomy was performed after a close examination. The resected right fallopian tube was cystically dilated, and a solid mass was observed in its lumen. The histological diagnosis was HGSC of the right fallopian tube with a papillary or complex tubular structure composed of tumor cells with marked nuclear irregularities. p53 was overexpressed, and no mesenchymal tumor component was observed. The resected left-sided abdominal mass of the omentum was a solid with a long diameter of 100 mm. Microscopically, the tumor exhibited a mixture of HGSC and high-grade sarcoma with nonspecific differentiation. Furthermore, a heterologous chondrosarcoma was subsequently observed from the high-grade sarcoma. The HGSC component was E-cadherin positive. The high-grade sarcoma component was positive for EMT-related proteins such as zinc finger E-box-binding homeobox 1 (ZEB1) and twist family bHLH transcription factor 1 (TWIST1). The chondrosarcoma component was ZEB1 positive and TWIST1 negative. p53 overexpression was found in all 3 components. The tumor of the omentum suggested that an EMT phenomenon was involved in the tumorigenesis. In this scenario, the primary HGSC of the fallopian tube with obvious invasion demonstrated that the conversion from carcinoma to sarcoma by EMT occurs only with peritoneal dissemination.

Decreased PANK1 expression in kidney renal clear cell carcinoma: impact on cell apoptosis, invasion, migration, and epithelial-mesenchymal transition

ObjectiveTo investigate pantothenate kinases 1 (PANK1) expression in kidney renal clear cell carcinoma (KIRC) tissues, analyze its correlation with clinicopathological features and prognosis, and explore its impact on invasion, migration, and apoptosis in KIRC cells.MethodsGEPIA (gene expression profiling interactive analysis), UALCAN and LinkedOmics, were employed to analyze PANK1 expression in KIRC tissues and its correlation with clinical characteristics. Comparative analyses were performed between KIRC (Caki-1 and 786-O) and noncancerous renal cells (HK-2 and RPTEC). Transfection with PANK1 activation particles was conducted, followed by Wound healing, Transwell assay, Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining, quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and Western blotting.ResultsPANK1 was down-regulated in KIRC tissues and cells compared to normal tissues and noncancerous cells. Correlation analyses linked PANK1 expression with clinicopathological features in KIRC, with high PANK1 expression associated with a favorable outcome. High PANK1 expression correlated positively with E-cadherin (CDH1), tight junction protein 1 (TJP1), Fas cell surface death receptor (FAS), caspase-8 (CASP8), and CASP9, while showing a negative correlation with vimentin (VIM), snail family transcriptional repressor 1 (SNAIL1), twist family BHLH transcription factor 1 (TWIST1), and TWIST2. PANK1 overexpression increased CDH1, TJP1, FAS, CASP8, and CASP9 while downregulating SNAIL1, VIM, TWIST1, and TWIST2, inhibiting invasion and migration, and promoting apoptosis in KIRC cells.ConclusionPANK1 down-regulation in KIRC tissues correlated with clinicopathological features and prognosis. Its overexpression modulated epithelial-mesenchymal transition (EMT)-related gene, inhibited invasion, promoted apoptosis in KIRC cells, highlighting its role in disease progression and therapeutic potential.

Inhibition of FBP1 expression by KMT5A through TWIST1 methylation is one of the mechanisms leading to chemoresistance in breast cancer.

Lysine methyltransferase 5A (KMT5A) is the sole mammalian enzyme known to catalyse the mono‑methylation of histone H4 lysine 20 and non‑histone proteins such as p53, which are involved in the occurrence and progression of numerous cancers. The present study aimed to determine the function of KMT5A in inducing docetaxel (DTX) resistance in patients with breast carcinoma by evaluating glucose metabolism and the underlying mechanism involved. The upregulation or downregulation of KMT5A‑related proteins was examined after KMT5A knockdown in breast cancer (BRCA) cells by Tandem Mass Tag proteomics. Through differential protein expression and pathway enrichment analysis, the upregulated key gluconeogenic enzyme fructose‑1,6‑bisphosphatase 1 (FBP1) was discovered. Loss of FBP1 expression is closely related to the development and prognosis of cancers. A dual‑luciferase reporter gene assay confirmed that KMT5A inhibited the expression of FBP1 and that overexpression of FBP1 could enhance the chemotherapeutic sensitivity to DTX through the suppression of KMT5A expression. The KMT5A inhibitor UNC0379 was used to verify that DTX resistance induced by KMT5A through the inhibition of FBP1 depended on the methylase activity of KMT5A. According to previous literature and interaction network structure, it was revealed that KMT5A acts on the transcription factor twist family BHLH transcription factor 1 (TWIST1). Then, it was verified that TWSIT1 promoted the expression of FBP1 by using a dual‑luciferase reporter gene experiment. KMT5A induces chemotherapy resistance in BRCA cells by promoting cell proliferation and glycolysis. After the knockdown of the KMT5A gene, the FBP1 related to glucose metabolism in BRCA was upregulated. KMT5A knockdown expression and FBP1 overexpression synergistically inhibit cell proliferation and block cells in the G2/M phase. KMT5A inhibits the expression of FBP1 by methylating TWIST1 and weakening its promotion of FBP1 transcription. In conclusion, KMT5A was shown to affect chemotherapy resistance by regulating the cell cycle and positively regulate glycolysis‑mediated chemotherapy resistance by inhibiting the transcription of FBP1 in collaboration with TWIST1. KMT5A may be a potential therapeutic target for chemotherapy resistance in BRCA.

Britanin - a beacon of hope against gastrointestinal tumors?

Britanin is a bioactive sesquiterpene lactone known for its potent anti-inflammatory and anti-oxidant properties. It also exhibits significant anti-tumor activity, suppressing tumor growth in vitro and in vivo. The current body of research on Britanin includes thirty papers predominantly related to neoplasms, the majority of which are gastrointestinal tumors that have not been summarized before. To drive academic debate, the present paper reviews the available research on Britanin in gastrointestinal tumors. It also outlines novel research directions using data not directly concerned with the digestive system, but which could be adopted in future gastrointestinal research. Britanin was found to counteract liver, colorectal, pancreatic, and gastric tumors, by regulating proliferation, apoptosis, autophagy, immune response, migration, and angiogenesis. As confirmed in pancreatic, gastric, and liver cancer, its most commonly noted molecular effects include nuclear factor kappa B and B-cell lymphoma 2 downregulation, as well as Bcl-2-associated X protein upregulation. Moreover, it has been found to induce the Akt kinase and Forkhead box O1 axis, activate the AMP-activated protein kinase pathway, elevate interleukin-2 and peroxisome proliferator-activated receptor-γ levels, reduce interleukin-10, as well as downregulate matrix metalloproteinase-9, Twist family bHLH transcription factor 1, and cyclooxygenase-2. It also inhibits Myc-HIF1α interaction and programmed death ligand 1 transcription by interrupting the Ras/ RAF/MEK/ERK pathway and mTOR/P70S6K/4EBP1 signaling. Future research should aim to unravel the link between Britanin and acetylcholinesterase, mast cells, osteolysis, and ischemia, as compelling data have been provided by studies outside the gastrointestinal context. Since the cytotoxicity of Britanin on noncancerous cells is significantly lower than that on tumor cells, while still being effective against the latter, further in-depth studies with the use of animal models are merited. The compound exhibits pleiotropic biological activity and offers considerable promise as an anti-cancer agent, which may address the current paucity of treatment options and high mortality rate among patients with gastrointestinal tumors.

Optimizing aspirin dose for colorectal cancer patients through deep phenotyping using novel biomarkers of drug action.

Background: Low-dose aspirin's mechanism of action for preventing colorectal cancer (CRC) is still debated, and the optimal dose remains uncertain. We aimed to optimize the aspirin dose for cancer prevention in CRC patients through deep phenotyping using innovative biomarkers for aspirin's action. Methods: We conducted a Phase II, open-label clinical trial in 34 CRC patients of both sexes randomized to receive enteric-coated aspirin 100mg/d, 100mg/BID, or 300mg/d for 3 ± 1weeks. Biomarkers were evaluated in blood, urine, and colorectal biopsies at baseline and after dosing with aspirin. Novel biomarkers of aspirin action were assessed in platelets and colorectal tissues using liquid chromatography-mass spectrometry to quantify the extent of cyclooxygenase (COX)-1 and COX-2 acetylation at Serine 529 and Serine 516, respectively. Results: All aspirin doses caused comparable % acetylation of platelet COX-1 at Serine 529 associated with similar profound inhibition of platelet-dependent thromboxane (TX)A2 generation ex vivo (serum TXB2) and in vivo (urinary TXM). TXB2 was significantly reduced in CRC tissue by aspirin 300mg/d and 100mg/BID, associated with comparable % acetylation of COX-1. Differently, 100mg/day showed a lower % acetylation of COX-1 in CRC tissue and no significant reduction of TXB2. Prostaglandin (PG)E2 biosynthesis in colorectal tumors and in vivo (urinary PGEM) remained unaffected by any dose of aspirin associated with the variable and low extent of COX-2 acetylation at Serine 516 in tumor tissue. Increased expression of tumor-promoting genes like VIM (vimentin) and TWIST1 (Twist Family BHLH Transcription Factor 1) vs. baseline was detected with 100mg/d of aspirin but not with the other two higher doses. Conclusion: In CRC patients, aspirin 300mg/d or 100mg/BID had comparable antiplatelet effects to aspirin 100mg/d, indicating similar inhibition of the platelet's contribution to cancer. However, aspirin 300mg/d and 100mg/BID can have additional anticancer effects by inhibiting cancerous tissue's TXA2 biosynthesis associated with a restraining impact on tumor-promoting gene expression. EUDRACT number: 2018-002101-65. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT03957902.

Twist family BHLH transcription factor 1 is required for the maintenance of leukemia stem cell in MLL-AF9+ acute myeloid leukemia.

Leukemia stem cells (LSC) are a rare population capable of limitless self-renewal and are responsible for the initiation, maintenance, and relapse of leukemia. Elucidation of the mechanisms underlying the regulation of LSC function could provide novel treatment strategies. Here, we show that TWIST1 is extremely highly expressed in the LSC of MLL-AF9+ acute myeloid leukemia (AML), and its upregulation is positively regulated by KDM4C in a H3K9me3 demethylation-dependent manner. We further demonstrate that TWIST1 is essential for the viability, dormancy, and self-renewal capacities of LSC, and that it promotes the initiation and maintenance of MLL-AF9-mediated AML. In addition, TWIST1 directly interacts and collaborates with HOXA9 in inducing AML in mice. Mechanistically, TWIST1 exerts its oncogenic function by activating the WNT5a/RAC1 axis. Collectively, our study uncovers a critical role of TWIST1 in LSC function and provides new mechanistic insights into the pathogenesis of MLL-AF9+ AML.

In Silico Identification of Therapeutic Targets and Novel Drug Candidates for Malignant Peripheral Nerve Sheath Tumors.

Malignant peripheral nerve sheath tumors (MPNSTs) are an aggressive form of sarcomas with a poor prognosis and limited treatment options. Therefore, new therapeutic targets are urgently needed to identify novel drugs. Based on the Gene Expression Omnibus database, an integrated analysis was performed to identify differentially expressed genes (DEGs) in MPNSTs compared to neurofibromas (NFs). Then functional enrichment analyses, protein-protein interaction (PPI) network construction, and hub gene selection were conducted. We explored DEG-guided repurposable drugs to treat MPNST based on the Library of Integrated Network-Based Cellular Signatures (LINCS) database. Furthermore, the binding affinity between predicted drug candidates and the MPNST-associated hub gene was calculated using molecular docking. We identified 89 DEGs in common with all three MPNSTs datasets. In the PPI networks, twist family bHLH transcription factor 1 (Twist1) with higher node degrees was further evaluated as a therapeutic target. Cytochalasin-d, cabozantinib, everolimus, refametinib, and BGT-226 were extracted from the LINCS database, which showed lower normalized connectivity scores (-1.88, -1.81, -1.78, -1.76, and -1.72, respectively) and was considered as drug candidates. In addition, the results of molecular docking between the five drugs and Twist1 showed a binding affinity of -6.61, -7.03, -7.73, -3.94, and -7.07 kcal/mol, respectively. Overall, our results describe the importance of Twist1 in MPNST pathogenesis. Everolimus was also found to be a potential therapeutic drug for MPNSTs.

Microrna 138 Upregulation is Associated with Decreasing Levels of CCND1 Gene Expression and Promoting Cell Death in Human Prostate Cancer Cell Lines

Background: This research intended to discover the significance of miR-138 (microRNA 138) on the expression profile, proliferation, and the associated regulatory mechanisms in prostate cancer (PCa). Methods: Thirty-five specimens of prostate were studied to evaluate the expression level of miR138 by RT-qPCR (Quantitative reverse transcription polymerase chain reaction). Bioinformatics analysis was performed to search for the target genes of miR-138; and ABL1 (ABL proto-oncogene 1, non-receptor tyrosine kinase), CCND1 (cyclin D1), CCND3 (cyclin D3), VIM (vimentin), TWIST1 (twist family bHLH transcription factor 1), HIF1A (hypoxia-inducible factor 1 subunit alpha), and TERT (telomerase reverse transcriptase) genes were selected. Then, the biological role of miR-138 and CCND1 in the progression of PCa was investigated using RT-qPCR and luciferase reporter gene assay. Finally, overexpression of miR-138 on the proliferation in PCa cell lines was analyzed using the MTT (3-(4, 5-dimethylthiazol-2-Yl)-2, 5-diphenyltetrazolium bromide, Sigma, Germany) assay. Results: RT-qPCR showed that the expression of miR-138 downregulated in PCa tissues and cell lines. Bioinformatics analysis and RT-qPCR assay demonstrated that CCND1 expression level was negatively correlated with miR-138 in PCa tissues and the PC3 cell line. Moreover, CCND1 was predicted to be the target gene of miR138 in the PC3 cell line based on the results of luciferase reporter gene assay. Substantially, over-expression of miR138-5p mimic could inhibit the expression level of CCND1 gene in PC3 cell lines. Lastly, over-expression of miR-138 inhibited the proliferative capacities in PC3 and DU-145 cells. Conclusion: Our research introduces miR-138 as a negative regulator of CCND1 in the progression of PCa with an inhibitory impact on the proliferation rate of PCa cell lines. This regulatory mechanism could be utilized for the design and target selection of remedial miRNA-based approaches.

Abstract 6705: Molecular detection of circulating cancer cells with cancer stem cell or mesenchymal characteristics in esophageal squamous cell carcinoma

Abstract Esophageal squamous cell carcinoma (ESCC) is a clinically challenging disease that requires a multidisciplinary approach. Unfortunately, the scarcity of ESCC genomic data hinders the understanding of ESCC biology, disease progression and rational therapy design. Circulating tumor cells (CTCs), which are shed from the primary and metastatic tumors and then circulate within the peripheral vasculature, reflect the existing tumor heterogeneity. Here, we utilized the non-biased size-based CTC enrichment strategy in combination with the real-time RT-PCR to molecularly characterize the CTCs with cancer stem cell (CSC) or mesenchymal properties in ESCC. Comprehensive data from ESCC cell lines, mouse ESCC xenograft models and clinical ESCC peripheral blood samples emphasize the importance of TWIST1 (Twist Family BHLH Transcription Factor 1) in ESCC progression. Gain-of-function and loss-of-function analyses demonstrate that TWIST1 promotes cell migration, invasion and colony formation in ESCC cells. Moreover, positive TWIST1 expression is responsible for the chemoresistance of ESCC cells to Cisplatin and is correlated with poor overall survival in ESCC patients. In addition, we show that TWIST1 promotes malignant potential, including tumor growth, invasion and chemoresistance via the TWIST1-TGFBI-ZEB1 signaling pathway in ESCC. Meanwhile, the TWIST1-TGFBI-ZEB1 signaling pathway confers immunosuppressive conditions to the tumor microenvironment, which in turn contributes to EMT to promote tumor progression. Collectively, these findings indicate that TWIST1 has a novel role in ESCC carcinogenesis by regulating tumorigenicity and cancer stem cell properties that may be useful as a prognostic monitoring biomarker and a promising therapeutic target in clinical ESCC treatment. Citation Format: Zhen Tan, Josephine Mun-Yee Ko, Valen Zhuoyou Yu, Hoi Yan Ng, Simon Law, Maria Li Lung. Molecular detection of circulating cancer cells with cancer stem cell or mesenchymal characteristics in esophageal squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6705.

Effect and Mechanism of lncRNA-PCMF1/hsa-miR-137/Twist1 Axis Involved inthe EMTRegulation of Prostate Cancer Cells.

The metastasis is a majorreason for the poor prognosis of the patients with prostate cancer (PC). Currently, androgen deprivation therapy (ADT) is the basic method for the treatment of PC regardless of surgery or drug treatments. However, ADT therapy is generally not recommended for patients with advanced/metastatic PC. Herein, wereportforthefirsttime a long non-coding RNA (lncRNA)-PCMF1 which promotes the progression of Epithelial-Mesenchymal Transition (EMT) in PC cells. Our data demonstrated that PCMF1 in metastatic PC tissues increased significantly compared to non-metastatic specimens. Mechanismresearchshowedthat PCMF1 could competitively bind to hsa-miR-137 instead of the 3' -Untranslated Region (UTR) of Twist Family BHLH Transcription Factor 1 (Twist1) by acting as an endogenous miRNA sponge. Furthermore,we found that silence of PCMF1 effectively blocked the EMT in PC cells by indirectly suppressing Twist1 protein mediated by hsa-miR-137 at post-transcriptional level. In summary, our research shows that PCMF1 promotes the EMT of PC cells by causing the functional inactivation of hsa-miR-137 on Twist1 protein, which is an independent risk factor of PC. PCMF1 knockdown combined with hsa-miR-137 expression is a promising PC-targeted therapy. Furthermore, PCMF1 is also expected toactas a useful marker for predicting malignantchanges and assessing the prognosis of PC patients.

MiR-137 Regulates Proliferation, Migration, Invasion and EMT of Nasopharyngeal Carcinoma Cells by Targeting TWIST1

To investigate the effects of miR-137 on biological cell function of nasopharyngeal carcinoma (NPC) cells. Totally, 31 pairs of NPC tissues and para-cancer tissues were collected. Meanwhile, human immortalized nasopharyngeal epithelial cell lines (NP69) and human NPC cell lines (6-10B) were cultured. The abilities of cell proliferation, invasion and migration were detected by CCK-8 and Transwell assay, respectively. The relative protein and mRNA expression level was detected by Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. In quantitative real-time polymerase chain reaction (qRT-PCR) experiment, miR-137 was found widely low-expressed in clinical samples and cell lines of nasopharyngeal carcinoma (NPC). On-line target gene prediction software was applied to screen potential downstream target of miR-137 in NPC. Then, Twist Family BHLH Transcription Factor 1 (TWIST1) was verified by luciferase reporter assay and Western blot experiments as a target for negative regulation of miR-137 in NPC cells. We up-regulated the expression of miR-137 and/or TWIST1 in 6-10Bin vitro, and then examined the effects of cell function after by CCK8, Transwell, scratch-wound and Western blot experiments. The results showed that decreased expression of TWIST1 resulting from up-regulation of miR-137 in 6-10B cells could inhibit the biological functions of cells including proliferation, invasion, migration and process of epithelial-mesenchymal transition (EMT). Our research discovered the suppressor function of miR-137 on NPC cells by targeting TWIST1, suggesting that miR-137 could be used as a potential therapeutic target for NPC.

MiR-372-3p promotes preeclampsia progression by regulating twist1.

Preeclampsia (PE) is a common pregnancy-related disorder worldwide. PE is mainly characterized by the defective migration and invasion of trophoblast cells. MicroRNAs (miRs) have been reported to serve an important role in PE. The purpose of the study was to explore the pathogenesis and therapeutic targets of preeclampsia. In the present study, reverse transcription-quantitative PCR analysis revealed that the expression levels of miR-372-3p were upregulated in placental tissues from patients with PE. Notably, the expression levels of miR-372-3p were significantly upregulated in patients with early-onset PE compared with patients with late-onset PE. Moreover, in vitro analysis using wound healing, Transwell and western blotting assays demonstrated that miR-372-3p overexpression inhibited the migration, invasion and epithelial-mesenchymal transition (EMT) of HTR-8/SVneo trophoblast cells, respectively. Bioinformatics analysis and a dual luciferase reporter assay revealed that miR-372-3p is sponged by twist family bHLH transcription factor 1 (twist1). Rescue experiments found that miR-372-3p overexpression suppressed trophoblast cell migration, invasion and EMT by downregulating the expression of twist1. In conclusion, the present study revealed that high level of miR-372-3p may act as a factor to cause PE and may also be a potential novel therapeutic target for PE.

INT6/eIF3e represses E-cadherin expression through HIF2α in lung carcinoma A549 cells.

Hypoxia-inducible factor 2 α (HIF2α), a transcription factor playing a vital role in hypoxia, promotes cancer metastasis. We had previously reported that the cancer-related gene integration site 6/eukaryotic translation initiation factor 3 subunit e (INT6/eIF3e) negatively regulates the protein stability of HIF2α in an oxygen-independent manner. Presently, the downstream targets for INT6/eIF3e-regulated HIF2α are unknown. Given the roles of HIF2α and INT6/eIF3e in epithelial-mesenchymal transition (EMT) that promotes cancer metastasis, we hypothesized that INT6/eIF3e-regulated HIF2α controls EMT. This study shows that INT6/eIF3e knockdown in lung carcinoma A549 cells led to increased expression of HIF2α protein and an EMT-like phenotypic change. The increased HIF2α subsequently repressed the E-cadherin gene. Mechanistically, HIF2α interacts with the twist family bHLH transcription factor 1 (TWIST1) known to regulate EMT process, and binds to the proximal promoter region of E-cadherin, repressing it. Collectively, our work demonstrates that HIF2α, regulated by INT6/eIF3e, represses the E-cadherin gene through TWIST1 to enhance EMT, suggesting a role of the INT6/eIF3e-HIF2α axis in cancer metastasis.

E3 ubiquitin ligase RBX1 drives the metastasis of triple negative breast cancer through a FBXO45-TWIST1-dependent degradation mechanism.

Triple-negative breast cancer (TNBC) patients are at high risk of recurrence and metastasis in the early stages, although receiving standard treatment. However, the underlying mechanism of TNBC remains unclear. Here, the critical effect of E3 ubiquitin ligase RBX1 in the metastasis of TNBC was reported for the first time. We discovered that RBX1 expression was evidently raised in the tissues of TNBC. Our clinical research displayed that high RBX1 expression was markedly related to poor distant invasion and survival. Functional analysis exhibited that RBX1 facilitated metastasis of TNBC cells through increasing EMT. Furthermore, we demonstrated that RBX1 knockdown increased the levels of the Twist family bHLH transcription factor 1 (TWIST1), is a significant regulator in the EMT process in some cancers. It can be observed an evident positive correlation between the TWIST1 and RBX1 levels, further confirming that EMT induced by RBX1 in TNBC cells is determined by TWIST1. Mechanistically, RBX1 modulates the expression of TWIST1 via modulating FBXO45, directly binding to FBXO45, and facilitating its degradation and ubiquitination. Briefly, our findings confirm that RBX1 is probably a new biomarker of TNBC carcinogenesis, thus suggesting that targeting the RBX1/FBXO45/TWIST1 axis may be an underlying strategy for TNBC treatment.

Hsa_circ_0016070/micro-340-5p Axis Accelerates Pulmonary Arterial Hypertension Progression by Upregulating TWIST1 Transcription Via TCF4/β-Catenin Complex.

Background Hypoxia is considered a major leading cause of pulmonary hypertension (PH). In this study, the roles and molecular mechanism of circ_0016070 in PH were studied. Methods and Results The expression of circ_0016070 in serum samples, human pulmonary artery smooth muscle cells and hypoxia/monocrotaline-treated rats was determined by real-time quantitative polymerase chain reaction. Cell viability, migration, and apoptosis were analyzed by Cell Counting Kit-8, wound healing, flow cytometry, and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assays, respectively. The molecular interactions were validated using RNA immunoprecipitation, chromatin immunoprecipitation, and dual luciferase reporter assays. The levels of phenotype switch-related proteins were evaluated by Western blot and immunohistochemistry. The pathological characteristics were assessed using hematoxylin and eosin staining. circ_0016070 was highly expressed in the serum samples, hypoxia-induced pulmonary artery smooth muscle cells and pulmonary arterial tissues of PH rats. Downregulation of circ_0016070 ameliorated the excessive proliferation, migration, vascular remodeling, and phenotypic transformation but enhanced cell apoptosis in the PH rat model. In addition, micro (miR)-340-5p was verified as a direct target of circ_0016070 and negatively regulated TCF4 (transcription factor 4) expression. TCF4 formed a transcriptional complex with β-catenin to activate TWIST1 (Twist family bHLH transcription factor 1) expression. Functional rescue experiments showed that neither miR-340-5p inhibition nor TWIST1 or TCF4 upregulation significantly impeded the biological roles of circ_0010670 silencing in PH. Conclusions These results uncovered a novel mechanism by which circ_0016070 play as a competing endogenouse RNA of miR-340-5p to aggravate PH progression by promoting TCF4/β-catenin/TWIST1 complex, which may provide potential therapeutic targets for PH.

Isoliquiritigenin inhibits non-small cell lung cancer progression via m6A/IGF2BP3-dependent TWIST1 mRNA stabilization

BackgroundN6-methyladenosine (m6A) has been identified to regulate the tumorigenesis and development of various tumors, including non-small cell lung cancer (NSCLC). Isoliquiritigenin (ISL), derived from the Chinese herb licorice, shows a significant anti-tumor activity on multiple human cancers. However, the role of ISL on NSCLC through m6A is still unclear. PurposeHere, we investigated the anti-tumor effect of ISL on NSCLC, and explored whether ISL affected the NSCLC phenotype by modulating its m6A modification. MethodsCell proliferation, migration and invasion assays were performed to evaluate the inhibitory effects of ISL on NSCLC cells. M6A enrichment was determined by m6A quantitative analysis. The mechanism regarding IGF2BP3 was explored using RIP-PCR, MeRIP-qPCR and RNA decay analysis. ResultsISL significantly repressed the proliferation, migration and invasion of NSCLC cells in vitro. In addition, m6A reader IGF2BP3 expression significantly increased in NSCLC tissues compared to adjacent tissues, and was positively correlated with NSCLC patients’ poor survival. Mechanistically, ISL reduced m6A modification and down-regulated IGF2BP3 expression in NSCLC. Furthermore, IGF2BP3 enhanced the mRNA stability of twist family bHLH transcription factor 1 (TWIST1) in m6A-dependent manner. Moreover, ISL treatment combined with TWSIT1 knockdown effectively reversed IGF2BP3 overexpression-induced NSCLC cells’ proliferation, migration and invasion. ConclusionOur findings uncover that ISL might function as an anticarcinogen through targeting IGF2BP3/m6A/TWIST1 axis for NSCLC.

EGFR inhibition reverses epithelial‑mesenchymal transition, and decreases tamoxifen resistance via Snail and Twist downregulation in breast cancer cells.

Tamoxifen resistance remains a major obstacle in the treatment of estrogen receptor (ER)‑positive breast cancer. In recent years, the crucial role of the epithelial‑mesenchymal transition (EMT) process in the development of drug resistance in breast cancer has been underlined. However, the central molecules inducing the EMT process during the development of tamoxifen resistance remain to be elucidated. In the present study, it was demonstrated that tamoxifen‑resistant breast cancer cells underwent EMT and exhibited an enhanced cell motility and invasive behavior. The inhibition of snail family transcriptional repressor1 (Snail) and twist family BHLH transcription factor1 (Twist) reversed the EMT phenotype and decreased the tamoxifen resistance, migration and invasion of tamoxifen‑resistant breast cancer cells. In addition, it was observed that the inhibition of epidermal growth factor receptor (EGFR) reversed the EMT phenotype in tamoxifen‑resistant MCF7 (MCF‑7/TR) cells via the downregulation of Snail and Twist. Notably, the EGFR inhibitor, gefitinib, decreased tamoxifen resistance, migration and invasion through the inhibition of Snail and Twist. On the whole, the results of the present study suggest that EGFR may be a promising therapeutic target for tamoxifen‑resistant breast cancer. Moreover, it was suggested that gefitinib may serve as a potent novel therapeutic strategy for breast cancer patients, who have developed tamoxifen resistance.

TWIST1-EP300 Expedites Gastric Cancer Cell Resistance to Apatinib by Activating the Expression of COL1A2.

The association between collagen type I alpha (COL1A) and chemoresistance has been verified in cancers. However, the specific role of COL1A2 in gastric cancer (GC) cell resistance to apatinib, a highly selective small-molecule inhibitor of vascular endothelial growth factor receptor 2, has not been investigated before. The purpose of this study was to explore the potential factors associated with COL1A2 regulation on GC cell apatinib resistance in vitro. With the aid of the Oncomine database and integrated bioinformatics methods, we identified COL1A2 overexpression in GC and its prognostic value. Mechanistically, the COL1A2 promoter has a distinct H3K27ac modification site and that E1A binding protein p300 (EP300) and twist family bHLH transcription factor 1 (TWIST1) can bind to the COL1A2 promoter, which in turn transcriptionally activated COL1A2 expression. In addition, overexpression of COL1A2 significantly promoted resistance to apatinib in GC cells, but knockdown of EP300 or TWIST1 remarkably inhibited COL1A2 expression and promoted sensitivity of GC cells to apatinib. Our findings demonstrated that the combination of EP300 and TWIST1 has a synergistically regulatory effect on COL1A2 expression, thus contributing to apatinib resistance in GC cells.

Anti-cancer potentials of Gynura procumbens leaves extract against two canine mammary cancer cell lines.

BackgroundThe anti‐cancer effects of Gynura procumbens leaves extract (GPE) have been reported in various human cancers. However, the anti‐cancer effects and molecular mechanisms of this extract on canine mammary cancer (CMC) have not yet been elucidated.ObjectivesThe main goal of this study was to investigate the anti‐cancer properties of GPE against two CMC cell lines (CHMp‐13a and CHMp‐5b).MethodsThe GP leaves were extracted with 80% ethanol. Anti‐cancer potentials of GPE on CHMp‐13a and CHMp‐5b cancer cell lines using dimethyl‐2‐thiazolyl‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT), wound healing, transwell migration, and caspase 3/7 activity assays were evaluated. The mRNA expression levels of two oncogenes: epidermal growth factor receptor (EGFR) and twist family bHLH transcription factor 1 (TWIST) and one tumour suppressor gene: phosphatase and tensin homolog (PTEN) in these cell lines were determined by quantitative real‐time PCR (qRT‐PCR). In addition, The EGFR and PTEN protein levels as well as protein kinase B (AKT) and extracellular signal‐regulated kinase 1/2 (ERK1/2) phosphorylation levels expression were also evaluated by western blot analysis.ResultsThe results showed that GPE caused a significant concentration‐ and time‐dependent reduction in cell proliferation of both CHMp‐13a and CHMp‐5b cells, detected by MTT assays. This extract also significantly suppressed cancer cell migration in both cell lines, tested by wound healing and transwell migration assays. Additionally, the increase in caspase 3/7 activity observed in both CMC cell treated with GPE suggests that GPE induced caspase 3/7 dependent apoptosis. Moreover, GPE significantly decreased EGFR mRNA and protein expression levels compared to control in both cell lines in a dose‐dependent manner.ConclusionThese findings emphasized that GPE has an in vitro anti‐cancer activity against CMC by inhibiting EGFR signalling pathway. Thus, GPE may serve as an alternative therapy in CMC with high EGFR expression.

Circ_0001658 regulates gefitinib resistance of non-small cell lung cancer through miR-409-3p/TWIST1 axis.

To investigate the function and mechanism of circular RNA circ_0001658 on gefitinib resistance of non-small cell lung cancer (NSCLC) cells. Circ_0001658, microRNA (miRNA, miR)-409-3p and twist family bHLH transcription factor 1 (TWIST1) expression levels in NSCLC tissues and cell lines were probed by quantitative real-time PCR and Western blot assays. Cell counting kit-8 assay was adopted to examine the inhibitory effect of different concentrations of gefitinib on the viability of NSCLC cells, with the 50% concentration of inhibition (IC50) value calculated. Besides, BrdU assay and flow cytometry assay were used to detect the proliferative and apoptotic rate of NSCLC cells. What's more, the binding relationships between miR-409-3p and circ_0001658, miR-409-3p and TWIST1 mRNA 3' untranslated region (3' UTR) were confirmed by dual-luciferase reporter gene assay and RNA immunoprecipitation assay. Circ_0001658 expression was raised in NSCLC tissue samples and cell lines, which was significantly associated with TNM stage and the differentiation degree of NSCLC tissues. Knocking down circ_0001658 could restrain the viability of NSCLC cells, promote the apoptosis, and reduce the IC50 of gefitinib, while transfection of miR-409-3p inhibitors could partially reverse these impacts. Additionally, circ_0001658 directly targeted miR-409-3p and negatively modulated its expression. TWIST1 was the target of miR-409-3p, which could be indirectly and positively modulated by circ_0001658. Moreover, circ_0001658 expression was negatively interrelated with miR-409-3p expression, while positively correlated with TWIST1 expression in NSCLC samples. Circ_0001658 promotes the malignant phenotypes and the resistance to gefitinib of NSCLC cells by regulating the miR-409-3p/TWIST1 axis.