Background/Aims: Metastasis is the leading cause resulting in high mortality in triple negative breast cancer (TNBC) patients. Cancer cells are skilled at utilizing thioredoxin (Trx) system as an efficient antioxidant system to counteract oxidative damage, facilitating the occurrence of metastasis. Here, we identified an organosulfur compound named DATS isolated from garlic, that inhibits the expression of Trx-1 and the enzyme activity of Trx reductase in breast cancer cells. Methods: Tissue microarray of breast cancer patients and immunohistochemical method were used to analyze the role of Trx-1 in breast cancer metastasis. Spotaneous metastasis model and experimental metastasis model combined with HE staining, immunohistochemistry were used to verify in vivo anti-metastatic effect of DATS as well as its regulation on thioredoxin. Western blot, immunofluorescence, redox state assessment and detection of enzyme activity were employed to determine the effect of DATS on thioredoxin system. Trx-1 siRNA interference was used to investigate the conclusive evidence that Trx-1 was the target of DATS. Results: In agreement with reduced Trx-1 nuclear translocation from cytoplasm by DATS, the production of reduced form of Trx-1 was dramatically decreased. Furthermore, in vivo, DATS administration was observed to significantly suppress spontaneous and experimental metastasis in nude mice. Delivery of DATS also resulted in decreased expression of Trx-1 as the direct target, as well as expression of NF-κB and MMP2/9 in primary tumor and lung tissue. Notably, the effects of DATS on the expression of downstream metastasis-associated genes were mediated by Trx-1, as demonstrated by the combination use of DATS and Trx-1 siRNA. Conclusion: Collectively, this present study indicates that targeting Trx system with DATS may provide a promising strategy for treating metastasis of TNBC.
Hepatic stellate cells (HSCs) represent a significant component of hepatocellular carcinoma (HCC) microenvironments which play a critical role in tumor progression and drug resistance. Tumor-on-a-chip technology has provided a powerful in vitro platform to investigate the crosstalk between activated HSCs and HCC cells by mimicking physiological architecture with precise spatiotemporal control. Here we developed a tri-cell culture microfluidic chip to evaluate the impact of HSCs on HCC progression. On-chip analysis revealed activated HSCs contributed to endothelial invasion, HCC drug resistance and natural killer (NK) cell exhaustion. Cytokine array and RNA sequencing analysis were combined to indicate the iron-binding protein LIPOCALIN-2 (LCN-2) as a key factor in remodeling tumor microenvironments in the HCC-on-a-chip. LCN-2 targeted therapy demonstrated robust anti-tumor effects both in vitro 3D biomimetic chip and in vivo mouse model, including angiogenesis inhibition, sorafenib sensitivity promotion and NK-cell cytotoxicity enhancement. Taken together, the microfluidic platform exhibited obvious advantages in mimicking functional characteristics of tumor microenvironments and developing targeted therapies.
Cryptotanshinone (CPT), a fat-soluble phenanthraquinone from Salvia miltiorrhiza Bunge, has been demonstrated to inhibit phosphorylation of p70 S6 kinase 1 (S6K1) and eukaryotic initiation factor 4E binding protein 1 (4E-BP1), a couple of direct downstream effectors of the mammalian target of rapamycin complex 1 (mTORC1), resulting in cancer cell arrested in G0 phase and subsequent inhibition of proliferation. However, its concrete molecular mechanism about how CPT inhibits mTORC1 signaling pathway is unclear. one solution was used to check cell viability and western blotting for determining expression of the indicated proteins. Molecular docking was performed to assess the binding of CPT with mTOR. The co-immunoprecipitation assay was to analyze whether CPT could disrupt the mTORC1 and TSC1/TSC2 complex. Recombinant adenoviral dominant-negative AMPKα was used to downregulate expression of AMPKα and lentiviral AMPK and TSC2 to silence the AMPK and TSC2 in Rh30 cells. Primarily, Rh30 cells expressing rapamycin-resistant mutant mTOR are also sensitive to CPT, while the molecular docking result for CPT binding to mTOR is negative, suggesting that CPT inhibition of mTORC1 is different from rapamycin. Then the related proteins of PTEN-PI3K pathway was proved not to be affected, but the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) was activated by a concentration- and time- dependent manner, meaning that it may be associated with AMPK. Further results indicated that compound C, inhibitor of AMPK, could clearly reversed CPT inhibitory effect on Rh30 cells, and dominant-negative AMPK in cancer cells conferred resistance to CPT inhibition of 4E-BP1 and phosphorylation of S6K1, as well as sh-AMPK. Furthermore, compared with AMPK-positive MEF cells, AMPK-negative MEF cells are less sensitive to CPT by the findings that 4E-BP1 and phosphorylation of S6K1 express comparatively more. Additionally, phosphorylation of tuberous sclerosis complex 2 (TSC2) was activated under the treatment of CPT, and down-expression of TSC2 by shRNA slightly recovered expression of 4E-BP1 and phosphorylation of S6K1, while co-immunoprecipitation of TSC2 did not alter expression of TSC1 by CPT. CPT inhibiting mTORC1 pathway was mostly due to activation of AMPK-TSC2 axis rather than specific binding to mTORC1. CPT is a potent anticancer agent targeting AMPK.
Biologically active natural products have been used for the chemoprevention of cutaneous tumors. Lycopene is the main active phytochemical in tomatoes. We herein aimed to assess the cancer preventive effects of lycopene and to find potential molecular targets. In chemically-induced cutaneous tumor mice and cell models, lycopene attenuated cutaneous tumor incidence and multiplicity as well as the tumorigenesis of normal cutaneous cells in phase-selectivity (only in the promotion phase) manners. By utilizing a comprehensive approach combining bioinformatics with network pharmacology, we predicted that intracellular autophagy and redox status were associated with lycopene's preventive effect on cutaneous tumors. Lycopene stimulated the activation of antioxidant enzymes and the translocation of the transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) that predominantly maintained intracellular redox equilibrium. The cancer chemopreventive effects were mediated by Nrf2. Further, lycopene enhanced the expression of autophagy protein p62. Therefore this led to the degradation of Keap1(Kelch ECH associating protein 1), the main protein locking Nrf2 in cytoplasm. In conclusion, our study provides preclinical evidence of the chemopreventive effects of lycopene on cutaneous tumors and reveals the mechanistic link between lycopene's stimulation of Nrf2 signaling pathway and p62-mediated degradation of Keap1 via the autophagy-lysosomal pathway.
Lipid nanoparticles (LNPs) hold great promise as carriers for developing drug delivery systems (DDSs) aimed at managing ischemic stroke (IS). Previous research has highlighted the vital role played by the lipid composition and biophysical characteristics of LNPs, influencing their interactions with cells and tissues. This understanding presents an opportunity to engineer LNPs tailored specifically for enhanced IS treatment. We previously introduced the innovative concept of reconstituted lipid nanoparticles (rLNPs), which not only retain the advantages of conventional LNPs but also incorporate lipids from the originating cell or tissue. Brain-derived rLNPs (B-rLNPs) exhibit significantly superior accumulation within the cerebral ischemic region when compared to liver-derived rLNPs (L-rLNPs). The homing effect of B-rLNPs was then employed to construct 3-n-butylphthalide (NBP) loaded DDS (B-rLNPs/NBP) for the treatment of IS. Our results demonstrated that compared with free NBP, B-rLNPs/NBP can significantly reduce infarct volume, neurological deficits, blood-brain barrier (BBB) leakage rate, brain water content, neutrophil infiltration, alleviate pathological structures, and improve the motor function in MCAO/R model. We also proved that B-rLNPs/NBP showed further reinforced protective effects on the same model than free NBP through the regulation of TLR4/MyD88/NF-κB (anti-inflammation) and Bax/Bcl-2 (anti-apoptosis) pathways. This study offers a promising tool towards improved IS treatment.