Photothermal therapy( PTT) is an extremely promising tumor therapeutic modality.H owever,e xcessive heat inevitably injures normal tissues near tumors,a nd the damage to cancer cells caused by mild hyperthermia is easily repaired by stress-induced heat shock proteins (HSPs). Thus, maximizing the PTT efficiency and minimizing the damage to healthy tissues simultaneously by adopting appropriate therapeutic temperatures is imperative.H erein, an innovative strategy is reported:f erroptosis-boosted mild PTT based on as ingle-atom nanozyme (SAzyme). The Pd SAzyme with atom-economical utilization of catalytic centers exhibits peroxidase (POD) and glutathione oxidase (GSHOx) mimicking activities,a nd photothermal conversion performance,w hich can result in ferroptosis featuring the up-regulation of lipid peroxides (LPO) and reactive oxygen species (ROS). The accumulation of LPO and ROSprovides apowerfulapproach for cleaving HSPs,which enables Pd SAzyme-mediated mildtemperature PTT.

Nuclear translocation of SMAD2/3, core transcription factors of TGFβ signaling, is critical for hepatic stellate cell (HSC) differentiation into metastasis-promoting myofibroblasts. SMAD2/3 have multiple coactivators, including WW domain-containing transcription regulator protein 1 (WWTR1 or TAZ) and p300 acetyltransferase. In the nucleus, TAZ binds to SMAD2/3 to prevent SMAD2/3 nuclear export. However, how TAZ and SMAD2/3 enter the nucleus remains poorly understood because neither contains a nuclear localization signal (NLS), an amino acid sequence tagging proteins for nuclear transport. P300 is a NLS-containing large scaffold protein so we hypothesized that SMAD2/3 and TAZ may undergo nuclear import through complexing with p300. Coimmunoprecipitation, immunofluorescence, and nuclear fractionation assays revealed that TGFβ1 promoted binding of SMAD2/3 and TAZ to p300 and that p300 inactivation disrupted TGFβ1-mediated SMAD2/3 and TAZ nuclear accumulation. Deleting the p300 NLS blocked TGFβ1-induced SMAD2/3 and TAZ nuclear transport. Consistently, p300 inactivation suppressed TGFβ1-mediated HSC activation and transcription of genes encoding tumor-promoting factors, such as CTGF, TNC, POSTN, PDGFC, and FGF2, as revealed by microarray analysis. ChIP-qPCR showed that canonical p300-mediated acetylation of histones also facilitated transcription in response to TGFβ1 stimulation. Interestingly, although both TGFβ1- and stiffness-mediated HSC activation require p300, comparison of gene expression datasets revealed that transcriptional targets of TGFβ1 were distinct from those of stiffness-p300 mechanosignaling. Lastly, in tumor/HSC coinjection and intrasplenic tumor injection models, targeting p300 of activated-HSC/myofibroblasts by C646, shRNA, or cre-mediated gene disruption reduced tumor and liver metastatic growth in mice. Conclusion: P300 facilitates TGFβ1-stimulated HSC activation by both non-canonical (cytoplasm-to-nucleus shuttle for SMAD2/3 and TAZ) and canonical (histone acetylation) mechanisms. P300 is an attractive target for inhibiting HSC activation and the prometastatic liver microenvironment.

TGFβ induces the differentiation of hepatic stellate cells (HSCs) into tumor‐promoting myofibroblasts but underlying mechanisms remain incompletely understood. Because endocytosis of TGFβ receptor II (TβRII), in response to TGFβ stimulation, is a prerequisite for TGF signaling, we investigated the role of protein diaphanous homolog 1 (known as Diaph1 or mDia1) for the myofibroblastic activation of HSCs. Using shRNA to knockdown Diaph1 or SMIFH2 to target Diaph1 activity of HSCs, we found that the inactivation of Diaph1 blocked internalization and intracellular trafficking of TβRII and reduced SMAD3 phosphorylation induced by TGFβ1. Mechanistic studies revealed that the N‐terminal portion of Diaph1 interacted with both TβRII and Rab5a directly and that Rab5a activity of HSCs was increased by Diaph1 overexpression and decreased by Diaph1 knockdown. Additionally, expression of Rab5aQ79L (active Rab5a mutant) increased whereas the expression of Rab5aS34N (inactive mutant) reduced the endosomal localization of TβRII in HSCs compared to the expression of wild‐type Rab5a. Functionally, TGFβ stimulation promoted HSCs to express tumor‐promoting factors, and α‐smooth muscle actin, fibronection, and CTGF, markers of myofibroblastic activation of HSCs. Targeting Diaph1 or Rab5a suppressed HSC activation and limited tumor growth in a tumor implantation mouse model. Thus, Dipah1 and Rab5a represent targets for inhibiting HSC activation and the hepatic tumor microenvironment.

Transforming growth factor β (TGFβ) induces hepatic stellate cell (HSC) differentiation into tumor-promoting myofibroblast, although underlying mechanism remains incompletely understood. Focal adhesion kinase (FAK) is activated in response to TGFβ stimulation, so it transmits TGFβ stimulus to extracellular signal-regulated kinase and P38 mitogenactivated protein kinase signaling. However, it is unknown whether FAK can, in return, modulate TGFβ receptors. In this study, we tested whether FAK phosphorylated TGFβ receptor 2 (TGFβR2) and regulated TGFβR2 intracellular trafficking in HSCs. The FAKY397F mutant and PF-573,228 were used to inhibit the kinase activity of FAK, the TGFβR2 protein level was quantitated by immunoblotting, and HSC differentiation into myofibroblast was assessed by expression of HSC activation markers, alpha-smooth muscle actin, fibronectin, or connective tissue growth factor. We found that targeting FAK kinase activity suppressed the TGFβR2 protein level, TGFβ1-induced mothers against decapentaplegic homolog phosphorylation, and myofibroblastic activation of HSCs. At the molecular and cellular level, active FAK (phosphorylated FAK at tyrosine 397) bound to TGFβR2 and kept TGFβR2 at the peripheral plasma membrane of HSCs, and it induced TGFβR2 phosphorylation at tyrosine 336. In contrast, targeting FAK or mutating Y336 to F on TGFβR2 led to lysosomal sorting and degradation of TGFβR2. Using RNA sequencing, we identified that the transcripts of 764 TGFβ target genes were influenced by FAK inhibition, and that through FAK, TGFβ1 stimulated HSCs to produce a panel of tumor-promoting factors, including extracellular matrix remodeling proteins, growth factors and cytokines, and immune checkpoint molecule PD-L1. Functionally, targeting FAK inhibited tumorpromoting effects of HSCs in vitro and in a tumor implantation mouse model. Conclusion: FAK targets TGFβR2 to the plasma membrane and protects TGFβR2 from lysosome-mediated degradation, thereby promoting TGFβ-mediated HSC activation. FAK is a target for suppressing HSC activation and the hepatic tumor microenvironment. (Hepatology Communications 2020;4:268-283).269 express α-smooth muscle actin (α-SMA), fibronectin and connective tissue growth factor (CTGF), markers of HSC activation, (4,5) and paracrine factors that promote liver metastatic growth. (6) Understanding how TGFβ signaling events are regulated, such as how TGFβ receptors distribute and traffic in HSCs, will help identify targets to inhibit HSC activation and the metastasis-promoting liver microenvironment.Focal adhesion kinase (FAK) is a 125-kDa nonreceptor tyrosine (Y) kinase. It consists of an N-terminal FERM domain, a middle kinase domain, and a C-terminal FAT domain. (7,8) Inactive FAK exists as an auto-inhibited monomer, and its autophosphorylation at Y397 creates a binding site for SH2 domain of Src, so that Src is recruited to induce phosphorylation of FAK at additional sites, leading to full activation of FAK kinase. (7,8) In addition, FAK functions as a protein scaffold for sign...

Photothermal therapy( PTT) is an extremely promising tumor therapeutic modality.H owever,e xcessive heat inevitably injures normal tissues near tumors,a nd the damage to cancer cells caused by mild hyperthermia is easily repaired by stress-induced heat shock proteins (HSPs). Thus, maximizing the PTT efficiency and minimizing the damage to healthy tissues simultaneously by adopting appropriate therapeutic temperatures is imperative.H erein, an innovative strategy is reported:f erroptosis-boosted mild PTT based on as ingle-atom nanozyme (SAzyme). The Pd SAzyme with atom-economical utilization of catalytic centers exhibits peroxidase (POD) and glutathione oxidase (GSHOx) mimicking activities,a nd photothermal conversion performance,w hich can result in ferroptosis featuring the up-regulation of lipid peroxides (LPO) and reactive oxygen species (ROS). The accumulation of LPO and ROSprovides apowerfulapproach for cleaving HSPs,which enables Pd SAzyme-mediated mildtemperature PTT.

Development of nanotheranostic agents with near-infrared (NIR) absorption offers an effective tool for fighting malignant diseases. Lanthanide ion neodymium (Nd3+)-based nanomaterials, due to the maximum absorption at around 800 nm and unique optical properties, have caught great attention as potential agents for simultaneous cancer diagnosis and therapy. Herein, we employed an active nanoplatform based on gadolinium-ion-doped NdVO4 nanoplates (NdVO4:Gd3+ NPs) for multiple-imaging-assisted photothermal therapy. These NPs exhibited enhanced NIR absorption and excellent biocompatibility after being grafted with polydopamine (pDA) and bovine serum albumin (BSA) layers on their surface. Upon expose to an 808 nm laser, these resulting NPs were able to trigger hyperthermia rapidly and cause photo-destruction of cancer cells. In a xenograft tumor model, tumor growth was also significantly inhibited by these photothermal agents under NIR laser irradiation. Owing to the multicomponent nanostructures, we demonstrated these nanoagents as being novel contrast agents for in vivo magnetic resonance (MR) imaging, X-ray computed tomography (CT), photoacoustic (PA) imaging, and second biological window fluorescent imaging of tumor models. Thus, we believe that this new kind of nanotherapeutic will benefit the development of emerging nanosystems for biological imaging and cancer therapy.