UNASSIGNED: Synovial sarcoma (SS) is an SS18-SSX fusion gene-driven soft tissue sarcoma with mesenchymal characteristics, associated with a poor prognosis due to frequent metastasis to a distant organ, such as the lung. Histone deacetylase (HDAC) inhibitors (HDACis) are arising as potent molecular targeted drugs, as HDACi treatment disrupts the SS oncoprotein complex, which includes HDACs, in addition to general HDACi effects. To provide further molecular evidence for the advantages of HDACi treatment and its limitations due to drug resistance induced by the microenvironment in SS cells, we examined cellular responses to HDACi treatment in combination with two-dimensional (2D) and 3D culture conditions.
UNASSIGNED: Using several SS cell lines, biochemical and cell biological assays were performed with romidepsin, an HDAC1/2 selective inhibitor. SN38 was concomitantly used as an ameliorant drug with romidepsin treatment. Cytostasis, apoptosis induction, and MHC class I polypeptide-related sequence A/B (MICA/B) induction were monitored to evaluate the drug efficacy. In addition to the conventional 2D culture condition, spheroid culture was adopted to evaluate the influence of cell-mass microenvironment on chemoresistance.
UNASSIGNED: By monitoring the cellular behavior with romidepsin and/or SN38 in SS cells, we observed that responsiveness is diverse in each cell line. In the apoptotic inducible cells, co-treatment with SN38 enhanced cell death. In nonapoptotic inducible cells, cytostasis and MICA/B induction were observed, and SN38 improved MICA/B induction further. As a novel efficacy of SN38, we revealed TWIST1 suppression in SS cells. In the spheroid (3D) condition, romidepsin efficacy was severely restricted in TWIST1-positive cells. We demonstrated that TWIST1 downregulation restored romidepsin efficacy even in spheroid form, and concomitant SN38 treatment along with romidepsin reproduced the reaction.
UNASSIGNED: The current study demonstrated the benefits and concerns of using HDACi for SS treatment in 2D and 3D culture conditions and provided molecular evidence that concomitant treatment with SN38 can overcome drug resistance to HDACi by suppressing TWIST1 expression.

The regeneration of peripheral nerves after injury is often slow and impaired, which may be associated with weakened and denervated muscles subsequently leading to atrophy. Adipose-derived stem cells (ADSCs) are often regarded as cell-based therapeutic candidate due to their regenerative potential. The study aims to assess the therapeutic efficacy of gene-modified ADSCs on sciatic nerve injury. We lentivirally transduced ADSCs with shRNA-TWIST1 and transplanted modified cells to rats undergoing sciatic nerve transection and repair. Results showed that TWIST1 knockdown accelerated functional recovery of rats with sciatic nerve injury as faster nerve conduction velocity and higher wire hang scores obtained by rats transplanted with TWIST1-silenced ADSCs than scramble ADSCs. Although the rats experienced degenerated axons and decreased myelin sheath thickness after sciatic nerve injury 8 weeks after operation, those transplanted with TWIST1-silenced ADSCs exhibited more signs of regenerated nerve fibers surrounded by newly formed myelin sheaths than those with scramble ADSCs. The rats transplanted with TWIST1-silenced ADSCs presented increased expressions of neurotrophic factors including neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and glial cell line-derived neurotrophic factor (GDNF) in the sciatic nerves than those with scramble ADSCs. These results suggest that genetically modifying TWIST1 in ADSCs could facilitate peripheral nerve repair after injury in a more efficient way than that with ADSCs alone.

In breast cancer, epithelial-mesenchymal transition (EMT) is positively associated with programmed death ligand 1 (PD-L1) expression and immune escape, and TWIST1 silences ERα expression and induces EMT and cancer metastasis. However, how TWIST1 regulates PD-L1 and immune evasion is unknown. This study analyzed TWIST1 and PD-L1 expression in breast cancers, investigated the mechanism for TWIST1 to regulate PD-L1 transcription, and assessed the effects of TWIST1 and PD-L1 in cancer cells on cytotoxic CD8+ T cells. Interestingly, TWIST1 expression is correlated with high-level PD-L1 expression in ERα-negative breast cancer cells. The overexpression and knockdown of TWIST1 robustly upregulate and downregulate PD-L1 expression, respectively. TWIST1 binds to the PD-L1 promoter and recruits the TIP60 acetyltransferase complex in a BRD8-dependent manner to transcriptionally activate PD-L1 expression, which significantly accelerates the exhaustion and death of the cytotoxic CD8+ T cells. Accordingly, knockdown of TWIST1 or BRD8 or inhibition of PD-L1 significantly enhances the tumor antigen-specific CD8+ T cells to suppress the growth of breast cancer cells. These results demonstrate that TWIST1 directly induces PD-L1 expression in ERα-negative breast cancer cells to promote immune evasion. Targeting TWIST1, BRD8, and/or PD-L1 in ERα-negative breast cancer cells with TWIST1 expression may sensitize CD8+ T-cell-mediated immunotherapy.

This chapter discusses the role of cardiac neural crest cells in the formation of the septum that divides the cardiac arterial pole into separate systemic and pulmonary arteries. Further, cardiac neural crest cells directly support the normal development and patterning of derivatives of the caudal pharyngeal arches, including the great arteries, thymus, thyroid, and parathyroids. Recently, cardiac neural crest cells have also been shown to indirectly influence the development of the secondary heart field, another derivative of the caudal pharynx, by modulating signaling in the pharynx. The contribution and function of the cardiac neural crest cells has been learned in avian models; most of the genes associated with cardiac neural crest function have been identified using mouse models. Together these studies show that the neural crest cells may not only critical for normal cardiovascular development but also may be involved secondarily because they represent a major component in the complex tissue interactions in the caudal pharynx and outflow tract. Cardiac neural crest cells span from the caudal pharynx into the outflow tract, and therefore may be susceptible to any perturbation in or by other cells in these regions. Thus, understanding congenital cardiac outflow malformations in human sequences of malformations resulting from genetic and/or environmental insults necessarily requires better understanding the role of cardiac neural crest cells in cardiac development.

BACKGROUND: Radiation-induced pulmonary fibrosis (RIPF) is a chronic, progressive, irreversible lung interstitial disease that develops after radiotherapy. Although several previous studies have focused on the mechanism of epithelial-mesenchymal transition (EMT) in lung epithelial cells, the essential factors involved in this process remain poorly understood. The DNA-dependent protein kinase catalytic subunit (DNA-PKcs) exhibits strong repair capacity when cells undergo radiation-induced damage; whether DNA-PKcs regulates EMT during RIPF remains unclear.
OBJECTIVE: To investigate the role and molecular mechanism of DNA-PKcs in RIPF and provide an important theoretical basis for utilising DNA-PKcs-targeted drugs for preventing RIPF.
METHODS: DNA-PKcs knockout (DPK-/-) mice were generated via the Cas9/sgRNA technique and subjected to whole chest ionizing radiation (IR) at a 20 Gy dose. Before whole chest IR, the mice were intragastrically administered the DNA-PKcs-targeted drug VND3207. Lung tissues were collected at 1 and 5 months after IR.
RESULTS: The expression of DNA-PKcs is low in pulmonary fibrosis (PF) patients. DNA-PKcs deficiency significantly exacerbated RIPF by promoting EMT in lung epithelial cells. Mechanistically, DNA-PKcs deletion by shRNA or inhibitor NU7441 maintained the protein stability of Twist1. Furthermore, AKT1 mediated the interaction between DNA-PKcs and Twist1. High Twist1 expression and EMT-associated changes caused by DNA-PKcs deletion were blocked by insulin-like growth factor-1 (IGF-1), an AKT1 agonist. The radioprotective drug VND3207 prevented IR-induced EMT and alleviated RIPF in mice by stimulating the kinase activity of DNA-PKcs.
CONCLUSIONS: Our study clarified the critical role and mechanism of DNA-PKcs in RIPF and showed that it could be a potential target for preventing RIPF.

BACKGROUND: Osteoarthritis (OA) is a chronic joint disease characterized by the degradation of articular cartilage. Polyphyllin I (PPI) has anti-inflammatory effects in many diseases. However, the mechanism of PPI in OA remains unclear.

Methods: HC-a cells treated with IL-1β were identified by immunofluorescence staining and microscopic observation. The expression of collagen II and DAPI in HC-a cells was detected by immunofluorescence. The effects of gradient concentration of PPI on IL-1β-induced cell viability, apoptosis, senescence, and inflammatory factor release were detected by MTT, flow cytometry, SA-β-Gal assay and ELISA, respectively. Expressions of apoptosis-related genes, extracellular matrix (ECM)- related genes, and TWIST1 were determined by qRT-PCR and western blot as needed. The above-mentioned experiments were conducted again after TWIST1 overexpression in IL-1β-induced chondrocytes.

Results: IL-1β reduced the number of chondrocytes and the density of collagen II. PPI (0.25, 0.5, 1 µmol/L) had no effect on cell viability, but it dose-dependently elevated the inhibition of cell viability regulated by IL-1β. The elevation of cell apoptosis, senescence and expression of IL-6 and TNF-α were suppressed by PPI in a dosedependent manner. Additionally, PPI reduced the expression of cleaved caspase-3, bax, MMP-3, and MMP-13 and promoted the expression of collagen II. TWIST1 expression was diminished by PPI. TWIST1 overexpression reversed the abovementioned effects of PPI on chondrocytes.

Conclusion: PPI suppressed apoptosis, senescence, inflammation, and ECM degradation of OA chondrocytes by downregulating the expression of TWIST1.

UNASSIGNED: Luteolin, a common dietary flavonoid found in plants, has been shown to have anti-cancer properties. However, its exact mechanisms of action in non-small cell lung cancer (NSCLC) are still not fully understood, particularly its role in regulating broader genomic networks and specific gene targets. In this study, we aimed to elucidate the role of microRNAs (miRNAs) in NSCLC treated with luteolin, using A549 cells as a model system.
UNASSIGNED: miRNA profiling was conducted on luteolin-treated A549 cells using Exiqon microarrays, with validation of selected miRNAs by qRT-PCR. Bioinformatic analysis identified the regulatory roles of miRNAs in biological processes and pathways following luteolin treatment. Computational algorithms were employed to identify potential target genes. A549 cells were transfected with miR-106a-5p mimic and inhibitor or their corresponding controls. The expression levels of 2 genes, twist basic helix-loop-helix transcription factor 1 (TWIST1) and matrix metallopeptidase 2 (MMP2), and cell migration were assessed.
UNASSIGNED: miRNA profiling identified 341 miRNAs, with 18 exhibiting significantly altered expression (P < 0.05). Subsequent qRT-PCR analysis confirmed altered expression of 6 selected miRNAs. KEGG and GO analyses revealed significant alterations in pathways and biological processes crucial for tumor biology. TWIST1 and MMP2, which both contain conserved miR-106a-5p binding sites, exhibited an inverse correlation with the expression levels of miR-106a-5p. Dual-luciferase reporter assays confirmed TWIST1 and MMP2 as direct targets of miR-106a-5p. Luteolin treatment led to a reduction in A549 cell migration, and this reduction was further amplified by the overexpression of miR-106a-5p.
UNASSIGNED: Luteolin inhibits A549 cell migration by modulating the miRNA landscape, shedding light on its mechanisms and laying the foundation for miRNA-based therapeutic approaches for NSCLC.

Exposure to diisodecyl phthalate (DIDP) during early pregnancy may be a risk factor for depressive behavior in offspring. While ozone (O3) exposure also raises the probability of depressive behavior during the preceding DIDP-induced process. In the present study, we investigated the effects of prenatal exposure to DIDP and O3 on the development of depressive-like behavior in offspring mice. The study found that prenatal exposure to both DIDP and O3 significantly increased depressive-like behavior in the offspring mice compared to either DIDP or O3 alone. Prenatal exposure to DIDP and O3 obviously increased the levels of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and cortisol, and decreased the levels of brain-derived neurotrophic factor (BDNF), 5-hydroxytryptamine (5-HT), dopamine (DA) and norepinephrine (NE) in the brain tissues of offspring mice. Transcriptome analysis further revealed significant alterations in genes related to oxidative stress and TWIST1 (a helix-loop-helix transcription factor) in response to the combined exposure to DIDP and O3. HPA axis activation, dysregulation of neurodevelopmental factors, oxidative stress and TWIST1 involvement, collectively contributed to the development of depression-like behaviors in offspring mice following prenatal exposure to DIDP and O3. Moreover, the study also verified the potential role of oxidative stress using vitamin E as an antioxidant. The findings provide valuable evidence for the relationship between co-exposure to DIDP and O3 and depression, highlighting the importance of considering the combined effects of multiple environmental pollutants in assessing their impact on mental health outcomes.

MicroRNAs are small RNA molecules that have a significant role in translational repression and gene silencing through binding to downstream target mRNAs. MiR-762 can stimulate the proliferation and metastasis of various types of cancer. Hippo pathway is one of the pathways that regulate tissue development and carcinogenesis. Dysregulation of this pathway plays a vital role in the progression of cancer. This study aimed to evaluate the possible correlation between miR-762, the Hippo signaling pathway, TWIST1, and SMAD3 in patients with lung cancer, as well as patients with chronic inflammatory diseases. The relative expression of miR-762, MST1, LATS2, YAP, TWIST1, and SMAD3 was determined in 50 lung cancer patients, 30 patients with chronic inflammatory diseases, and 20 healthy volunteers by real-time PCR. The levels of YAP protein and neuron-specific enolase were estimated by ELISA and electrochemiluminescence immunoassay, respectively. Compared to the control group, miR-762, YAP, TWIST1, and SMAD3 expression were significantly upregulated in lung cancer patients and chronic inflammatory patients, except SMAD3 was significantly downregulated in chronic inflammatory patients. MST1, LATS2, and YAP protein were significantly downregulated in all patients. MiR-762 has a significant negative correlation with MST1, LATS2, and YAP protein in lung cancer patients and with MST1 and LATS2 in chronic inflammatory patients. MiR-762 may be involved in the induction of malignant behaviors in lung cancer through suppression of the Hippo pathway. MiR-762, MST1, LATS2, YAP mRNA and protein, TWIST1, and SMAD3 may be effective diagnostic biomarkers in both lung cancer patients and chronic inflammatory patients. High YAP, TWIST1, SMA3 expression, and NSE level are associated with a favorable prognosis for lung cancer.

Background: Ulcerative colitis (UC) is a common and progressive inflammatory bowel disease primarily affecting the colon and rectum. Prolonged inflammation can lead to colitis-associated colorectal cancer (CAC). While the exact cause of UC remains unknown, this study aims to investigate the role of the TWIST1 gene in UC. Methods: Second-generation sequencing data from adult UC patients were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified, and characteristic genes were selected using machine learning and Lasso regression. The Receiver Operating Characteristic (ROC) curve assessed TWIST1\'s potential as a diagnostic factor (AUC score). Enriched pathways were analyzed, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Variation Analysis (GSVA). Functional mechanisms of marker genes were predicted, considering immune cell infiltration and the competing endogenous RNA (ceRNA) network. Results: We found 530 DEGs, with 341 upregulated and 189 downregulated genes. TWIST1 emerged as one of four potential UC biomarkers via machine learning. TWIST1 expression significantly differed in two datasets, GSE193677 and GSE83687, suggesting its diagnostic potential (AUC = 0.717 in GSE193677, AUC = 0.897 in GSE83687). Enrichment analysis indicated DEGs associated with TWIST1 were involved in processes like leukocyte migration, humoral immune response, and cell chemotaxis. Immune cell infiltration analysis revealed higher rates of M0 macrophages and resting NK cells in the high TWIST1 expression group, while TWIST1 expression correlated positively with M2 macrophages and resting NK cell infiltration. We constructed a ceRNA regulatory network involving 1 mRNA, 7 miRNAs, and 32 long non-coding RNAs (lncRNAs) to explore TWIST1\'s regulatory mechanism. Conclusion: TWIST1 plays a significant role in UC and has potential as a diagnostic marker. This study sheds light on UC\'s molecular mechanisms and underscores TWIST1\'s importance in its progression. Further research is needed to validate these findings in diverse populations and investigate TWIST1 as a therapeutic target in UC.