Isotoosendanin exerts inhibition on triple-negative breast cancer through abrogating TGF-β-induced epithelial-mesenchymal transition via directly targeting TGFβR1

LncRNA XIST/miR-455-3p/HOXC4 axis promotes breast cancer development by activating TGF-β/SMAD signaling pathway

Breast cancer is the second primary cause of cancer death among women. Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is a central regulator for X chromosome inactivation, and its abnormal expression is a primary feature of breast cancer. So far, the mechanism of XIST in breast cancer has not been fully elucidated. We attempted to illustrate the mechanism of XIST in breast cancer. The expressions of XIST, microRNA-455-3p (miR-455-3p) in breast cancer were measured using quantitative real-time PCR. The expressions of homeobox C4 (HOXC4) were assessed with immunohistochemical and Western blot. Also, the functions of XIST in breast cancer were assessed by Cell Counting Kit-8 analysis, colony formation assay, flow cytometry, Western blot, Transwell, and cell scratch assays. Meanwhile, the mechanism of XIST in breast cancer was validated using database analysis and dual-luciferase reporter assay. Furthermore, the function of XIST in breast cancer in vivo was estimated by tumor xenograft model, immunohistochemical assay, and hematoxylin-eosin staining. XIST and HOXC4 expressions were increased, but miR-455-3p expressions were decreased in breast cancer tissues and cells. Knocking down XIST restrained breast cancer cell proliferation, invasion, migration, epithelial-mesenchymal transformation (EMT), and induced cell cycle arrest at G0/G1. Meanwhile, XIST interacted with miR-455-3p, while miR-455-3p interacted with HOXC4. XIST knockdown repressed breast cancer cell proliferation, invasion, and EMT, while miR-455-3p inhibitor or HOXC4 overexpression abolished those impacts. HOXC4 overexpression also blocked the impacts of miR-455-3p mimic on breast cancer cell malignant behavior. In vivo experimental data further indicated that XIST knockdown repressed breast cancer cell tumorigenic ability, and decreased HOXC4 and p-SMAD3 (TGF-β/SMAD-related protein) expressions.XIST/miR-455-3p/HOXC4 facilitated breast cancer development by activating the TGF-β/SMAD pathway.

Isotoosendanin exerts anti-tumor effects in NSCLC by enhancing the stability of SHP-2 and inhibiting the JAK/STAT3 pathway

BACKGROUND

Lung cancer has been considered as a serious problem for the public health system. NSCLC is the main type of lung cancer, and finding improved treatments for NSCLC is a pressing concern. In this study, we have explored the efficacy of isotoosendanin (ITSN) for the treatment of NSCLC, and also explored the potential underlying mechanisms.

METHODS

NSCLC cells were cultured, and colony formation, cell cycle as well as apoptosis assays have been conducted for investigating the biological functions of ITSN on NSCLC cells. Furthermore, target genes of ITSN have been predicted via PharmMapper and SuperPred database, subsequently validated using the drug affinity responsive target stability (DARTS) approach, a cellular thermal shift assay (CETSA) as well as surface plasmon resonance (SPR) analysis. Additionally, ubiquitination experiments have been conducted for the level of ubiquitination of the NSCLC cells. Finally, a nude mouse xenograft model has been established for evaluating the anti-tumor effects of ITSN in vivo.

RESULTS

ITSN has shown anti-NSCLC activities both in vitro and in vivo. Mechanistically, ITSN interacts with SHP-2 through enhancing its stability and decreases the level of ubiquitination. Notably, ITSN may regulate the behaviors of NSCLC cells via affecting the JAK/STAT3 signaling, and finally, the anti-tumor effects of ITSN was partially reversed by the application of SHP-2 inhibitor or siRNA of SHP-2.

CONCLUSIONS

ITSN may exert its anti-tumor effects by directly targeting SHP-2, increasing its stability and minimizing its ubiquitination. These results imply that ITSN could be a revolutionary component for treating NSCLC.

Mitochondrial metabolism blockade nanoadjuvant reversed immune-resistance microenvironment to sensitize albumin-bound paclitaxel-based chemo-immunotherapy

Currently, the efficacy of albumin-bound paclitaxel (PTX@Alb) is still limited due to the impaired PTX@Alb accumulation in tumors partly mediated by the dense collagen distribution. Meanwhile, acquired immune resistance always occurs due to the enhanced programmed cell death-ligand 1 (PD-L1) expression after PTX@Alb treatment, which then leads to immune tolerance. To fill these gaps, we newly revealed that tamoxifen (TAM), a clinically widely used adjuvant therapy for breast cancer with mitochondrial metabolism blockade capacity, could also be used as a novel effective PD-L1 and TGF-β dual-inhibitor via inducing the phosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK) protein. Following this, to obtain a more significant effect, TPP-TAM was prepared by conjugating mitochondria-targeted triphenylphosphine (TPP) with TAM, which then further self-assembled with albumin (Alb) to form TPP-TAM@Alb nanoparticles. By doing this, TPP-TAM@Alb nanoparticles effectively decreased the expression of collagen in vitro, which then led to the enhanced accumulation of PTX@Alb in 4T1 tumors. Besides, TPP-TAM@Alb also effectively decreased the expression of PD-L1 and TGF-β in tumors to better sensitize PTX@Alb-mediated chemo-immunotherapy by enhancing T cell infiltration. All in all, we newly put forward a novel mitochondrial metabolism blockade strategy to inhibit PTX@Alb-resistant tumors, further supporting its better clinical application.

Forsythiaside-A improved bile-duct-ligation-induced liver fibrosis in mice: The involvement of alleviating mitochondrial damage and ferroptosis in hepatocytes via activating Nrf2

Liver fibrosis is a key and reversible stage in the progression of many chronic liver diseases to cirrhosis or hepatocellular carcinoma. Forsythiaside-A (FTA), a main compound isolated from Forsythiae Fructus, has an excellent liver protective activity. This study aims to investigate the efficacy of FTA in improving cholestatic liver fibrosis. Bile-duct-ligation (BDL) was conducted to induce liver fibrosis in mice. Hepatic collagen deposition was evaluated by Masson and Sirus red staining. The bile acid spectrum in the liver and serum was analyzed by mass spectrometry. Liver oxidative stress injury and mitochondria damage were observed by using Mito-Tracker Red fluorescence staining, transmission electron microscopy, etc. The level of ferrous iron (Fe2+) and the expression of ferroptosis-associated molecules were detected. The binding between FTA and its target protein was confirmed by Co-immunoprecipitation (Co-IP), cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) and surface plasmon resonance (SPR). Our results demonstrated that FTA alleviated BDL-induced liver fibrosis in mice. FTA did not decrease the elevated amount of bile acids in BDL-treated mice, but reduced the bile acid-induced mitochondrial damage, oxidative stress and ferroptosis in hepatocytes, and also induced nuclear factor erythroid 2-related factor-2 (Nrf2) activation. In Nrf2 knock-out mice, the FTA-provided protection against BDL-induced liver fibrosis was disappeared, and FTA's inhibition on mitochondrial damage, oxidative stress and ferroptosis were lowered. Further results displayed that FTA could directly bind to Kelch-like ECH-associated protein-1 (Keap1), thereby activating Nrf2. Moreover, the BDL-induced liver fibrosis was markedly weakened in liver-specific Keap1 knockout mice. Hence, this study suggests that FTA alleviated the BDL-induced liver fibrosis through attenuating mitochondrial damage and ferroptosis in hepatocytes by activating Nrf2 via directly binding to Keap1.

Soloxolone para-methylanilide effectively suppresses aggressive phenotype of glioblastoma cells including TGF-β1-induced glial-mesenchymal transition in vitro and inhibits growth of U87 glioblastoma xenografts in mice

Soloxolone amides are semisynthetic triterpenoids that can cross the blood-brain barrier and inhibit glioblastoma growth both in vitro and in vivo. Here we investigate the impact of these compounds on processes associated with glioblastoma invasiveness and therapy resistance. Screening of soloxolone amides against glioblastoma cells revealed the ability of compound 7 (soloxolone para-methylanilide) to inhibit transforming growth factor-beta 1 (TGF-β1)-induced glial-mesenchymal transition Compound 7 inhibited morphological changes, wound healing, transwell migration, and expression of mesenchymal markers (N-cadherin, fibronectin, Slug) in TGF-β1-induced U87 and U118 glioblastoma cells, while restoring their adhesiveness. Confocal microscopy and molecular docking showed that 7 reduced SMAD2/3 nuclear translocation probably by direct interaction with the TGF-β type I and type II receptors (TβRI/II). In addition, 7 suppressed stemness of glioblastoma cells as evidenced by inhibition of colony forming ability, spheroid growth, and aldehyde dehydrogenase (ALDH) activity. Furthermore, 7 exhibited a synergistic effect with temozolomide (TMZ) on glioblastoma cell viability. Using N-acetyl-L-cysteine (NAC) and flow cytometry analysis of Annexin V-FITC-, propidium iodide-, and DCFDA-stained cells, 7 was found to synergize the cytotoxicity of TMZ by inducing ROS-dependent apoptosis. Further in vivo studies showed that 7, alone or in combination with TMZ, effectively suppressed the growth of U87 xenograft tumors in mice. Thus, 7 demonstrated promising potential as a component of combination therapy for glioblastoma, reducing its invasiveness and increasing its sensitivity to chemotherapy.

Isotoosendanin inhibits triple-negative breast cancer metastasis by reducing mitochondrial fission and lamellipodia formation regulated by the Smad2/3-GOT2-MYH9 signaling axis

Triple-negative breast cancer (TNBC) is incurable and prone to widespread metastasis. Therefore, identification of key targets for TNBC progression is urgently needed. Our previous study revealed that isotoosendanin (ITSN) reduced TNBC metastasis by targeting TGFβR1. ITSN is currently used as an effective chemical probe to further discover the key molecules involved in TNBC metastasis downstream of TGFβR1. The results showed that GOT2 was the gene downstream of Smad2/3 and that ITSN decreased GOT2 expression by abrogating the activation of the TGF-β-Smad2/3 signaling pathway through directly binding to TGFβR1. GOT2 was highly expressed in TNBC, and its knockdown decreased TNBC metastasis. However, GOT2 overexpression reversed the inhibitory effect of ITSN on TNBC metastasis both in vitro and in vivo. GOT2 interacted with MYH9 and hindered its binding to the E3 ubiquitin ligase STUB1, thereby reducing MYH9 ubiquitination and degradation. Moreover, GOT2 also enhanced the translocation of MYH9 to mitochondria and thus induced DRP1 phosphorylation, thereby promoting mitochondrial fission and lamellipodia formation in TNBC cells. ITSN-mediated inhibition of mitochondrial fission and lamellipodia formation was associated with reduced GOT2 expression. In conclusion, ITSN prevented MYH9-regulated mitochondrial fission and lamellipodia formation in TNBC cells by enhancing MYH9 protein degradation through a reduction in GOT2 expression, thus contributing to its inhibition of TNBC metastasis.