ThermomiR-377-3p-induced suppression of Cirbp expression is required for effective elimination of cancer cells and cancer stem-like cells by hyperthermia.

BACKGROUND: In recent years, the development of adjunctive therapeutic hyperthermia for cancer therapy has received considerable attention. However, the mechanisms underlying hyperthermia resistance are still poorly understood. In this study, we investigated the roles of cold­inducible RNA binding protein (Cirbp) in regulating hyperthermia resistance and underlying mechanisms in nasopharyngeal carcinoma (NPC). METHODS: CCK-8 assay, colony formation assay, tumor sphere formation assay, qRT-PCR, Western blot were employed to examine the effects of hyperthermia (HT), HT + oridonin(Ori) or HT + radiotherapy (RT) on the proliferation and stemness of NPC cells. RNA sequencing was applied to gain differentially expressed genes upon hyperthermia. Gain-of-function and loss-of-function experiments were used to evaluate the effects of RNAi-mediated Cirbp silencing or Cirbp overexpression on the sensitivity or resistance of NPC cells and cancer stem-like cells to hyperthermia by CCK-8 assay, colony formation assay, tumorsphere formation assay and apoptosis assay, and in subcutaneous xenograft animal model. miRNA transient transfection and luciferase reporter assay were used to demonstrate that Cirbp is a direct target of miR-377-3p. The phosphorylation levels of key members in ATM-Chk2 and ATR-Chk1 pathways were detected by Western blot. RESULTS: Our results firstly revealed that hyperthermia significantly attenuated the stemness of NPC cells, while combination treatment of hyperthermia and oridonin dramatically increased the killing effect on NPC cells and cancer stem cell (CSC)­like population. Moreover, hyperthermia substantially improved the sensitivity of radiation­resistant NPC cells and CSC­like cells to radiotherapy. Hyperthermia noticeably suppressed Cirbp expression in NPC cells and xenograft tumor tissues. Furthermore, Cirbp inhibition remarkably boosted anti­tumor­killing activity of hyperthermia against NPC cells and CSC­like cells, whereas ectopic expression of Cirbp compromised tumor­killing effect of hyperthermia on these cells, indicating that Cirbp overexpression induces hyperthermia resistance. ThermomiR-377-3p improved the sensitivity of NPC cells and CSC­like cells to hyperthermia in vitro by directly suppressing Cirbp expression. More importantly, our results displayed the significantly boosted sensitization of tumor xenografts to hyperthermia by Cirbp silencing in vivo, but ectopic expression of Cirbp almost completely counteracted hyperthermia-mediated tumor cell-killing effect against tumor xenografts in vivo. Mechanistically, Cirbp silencing-induced inhibition of DNA damage repair by inactivating ATM-Chk2 and ATR-Chk1 pathways, decrease in stemness and increase in cell death contributed to hyperthermic sensitization; conversely, Cirbp overexpression-induced promotion of DNA damage repair, increase in stemness and decrease in cell apoptosis contributed to hyperthermia resistance. CONCLUSION: Taken together, these findings reveal a previously unrecognized role for Cirbp in positively regulating hyperthermia resistance and suggest that thermomiR-377-3p and its target gene Cirbp represent promising targets for therapeutic hyperthermia.

Proton pump inhibitor-enhanced nanocatalytic ferroptosis induction for stimuli-responsive dual-modal molecular imaging guided cancer radiosensitization.

Although radiotherapeutic efficiency has been revealed to be positively correlated with ferroptosis, the neutral/alkaline cytoplasm pH value of tumor cells remains an intrinsic challenge for efficient Fenton/Fenton-like reaction-based ferroptosis induction. Herein, PEGylated hollow mesoporous organosilica nanotheranostics (HMON)-GOx@MnO2 nanoparticles (HGMP NPs) were designed as a ferroptosis inducer, which could specifically release Mn2+ in tumor cells to activate the Fenton-like reaction for ferroptosis induction. Proton pump inhibitors (PPIs) were synchronously administered for cytoplasm pH level regulation by inhibiting V-H+-ATPases activity, enhancing Fenton-like reaction-based ferroptosis induction. Moreover, reactive oxygen species production was facilitated via the glucose oxidase triggered cascade catalytic reaction by utilizing intracellular ß-D-glucose for H2O2 self-supply and generation of additional cytoplasm H+. The PPI enhanced ferroptosis inducing nanosystem effectively inhibited tumor growth both in vitro and in vivo for tumor-specific ferroptosis induction and radiotherapy sensitization, suggesting that PPI administration could be an efficient adjuvant to reinforce Fenton/Fenton-like reaction-based ferroptosis induction for radiosensitization. STATEMENT OF SIGNIFICANCE: The cytoplasm pH value of tumor cells is typically neutral to alkaline, which is higher than that of the Fenton/Fenton-like reaction desired acidic environments, hindering its efficiency. In this study, PEGylated hollow mesoporous organosilica nanotheranostics (HMON)-GOx@MnO2 nanoparticles were synthesized as a ferroptosis inducer, which could specifically release Mn2+ via depleting glutathione and then activate the Fenton-like reaction in the tumor microenvironment. The glucose oxidase was applied for H2O2 self-supply and addition of cytoplasm H+ to further boost the Fenton-like reaction. We found that proton pump inhibitors (PPIs) increased intracellular acidification by inhibiting the activity of V-H+-ATPases to enhance the Fenton reaction-based ferroptosis induction, suggesting PPIs administration could be a feasible strategy to reinforce ferroptosis induction for radiosensitization.

Functionalized Au@Cu-Sb-S Nanoparticles for Spectral CT/Photoacoustic Imaging-Guided Synergetic Photo-Radiotherapy in Breast Cancer.

BACKGROUND: Radiotherapy (RT) is clinically well-established cancer treatment. However, radioresistance remains a significant issue associated with failure of RT. Phototherapy-induced radiosensitization has recently attracted attention in translational cancer research. METHODS: Cu-Sb-S nanoparticles (NPs) coated with ultra-small Au nanocrystals (Au@Cu-Sb-S) were synthesized and characterized. The biosafety profiles, absorption of near-infrared (NIR) laser and radiation-enhancing effect of the NPs were evaluated. In vitro and in vivo spectral computed tomography (CT) imaging and photoacoustic (PA) imaging were performed in 4T1 breast cancer-bearing mice. The synergetic radio-phototherapy was assessed by in vivo tumor inhibition studies. RESULTS: Au@Cu-Sb-S NPs were prepared by in situ growth of Au NCs on the surface of Cu-Sb-S NPs. The cell viability experiments showed that the combination of Au@Cu-Sb-S+NIR+RT was significantly more cytotoxic to tumor cells than the other treatments at concentrations above 25 ppm Sb. In vitro and in vivo spectral CT imaging demonstrated that the X-ray attenuation ability of Au@Cu-Sb-S NPs was superior to that of the clinically used Iodine, particularly at lower KeV levels. Au@Cu-Sb-S NPs showed a concentration-dependent and remarkable PA signal brightening effect. In vivo tumor inhibition studies showed that the prepared Au@Cu-Sb-S NPs significantly suppressed tumor growth in 4T1 breast cancer-bearing mice treated with NIR laser irradiation and an intermediate X-ray dose (4 Gy). CONCLUSION: These results indicate that Au@Cu-Sb-S integrated with spectral CT, PA imaging, and phototherapy-enhanced radiosensitization is a promising multifunctional theranostic nanoplatform for clinical applications.

Graphene oxide (GO)-based nanosheets with combined chemo/photothermal/photodynamic therapy to overcome gastric cancer (GC) paclitaxel resistance by reducing mitochondria-derived adenosine-triphosphate (ATP).

BACKGROUND: Paclitaxel (PTX) has been suggested to be a promising front-line drug for gastric cancer (GC), while P-glycoprotein (P-gp) could lead to drug resistance by pumping PTX out of GC cells. Consequently, it might be a hopeful way to combat drug resistance by inhibiting the out-pumping function of P-gp. RESULTS: In this study, we developed a drug delivery system incorporating PTX onto polyethylene glycol (PEG)-modified and oxidized sodium alginate (OSA)-functionalized graphene oxide (GO) nanosheets (NSs), called PTX@GO-PEG-OSA. Owing to pH/thermal-sensitive drug release properties, PTX@GO-PEG-OSA could induced more obvious antitumor effects on GC, compared to free PTX. With near infrared (NIR)-irradiation, PTX@GO-PEG-OSA could generate excessive reactive oxygen species (ROS), attack mitochondrial respiratory chain complex enzyme, reduce adenosine-triphosphate (ATP) supplement for P-gp, and effectively inhibit P-gp's efflux pump function. Since that, PTX@GO-PEG-OSA achieved better therapeutic effect on PTX-resistant GC without evident toxicity. CONCLUSIONS: In conclusion, PTX@GO-PEG-OSA could serve as a desirable strategy to reverse PTX's resistance, combined with chemo/photothermal/photodynamic therapy.

Biodegradable hollow mesoporous organosilica nanotheranostics (HMON) for multi-mode imaging and mild photo-therapeutic-induced mitochondrial damage on gastric cancer.

BACKGROUND: CuS-modified hollow mesoporous organosilica nanoparticles (HMON@CuS) have been preferred as non-invasive treatment for cancer, as near infrared (NIR)-induced photo-thermal effect (PTT) and/or photo-dynamic effect (PDT) could increase cancer cells' apoptosis. However, the certain role of HMON@CuS-produced-PTT&PDT inducing gastric cancer (GC) cells' mitochondrial damage, remained unclear. Moreover, theranostic efficiency of HMON@CuS might be well improved by applying multi-modal imaging, which could offer an optimal therapeutic region and time window. Herein, new nanotheranostics agents were reported by Gd doped HMON decorated by CuS nanocrystals (called HMON@CuS/Gd). RESULTS: HMON@CuS/Gd exhibited appropriate size distribution, good biocompatibility, L-Glutathione (GSH) responsive degradable properties, high photo-thermal conversion efficiency (82.4%) and a simultaneous reactive oxygen species (ROS) generation effect. Meanwhile, HMON@CuS/Gd could efficiently enter GC cells, induce combined mild PTT (43-45 °C) and PDT under mild NIR power density (0.8 W/cm2). Surprisingly, it was found that PTT might not be the only factor of cell apoptosis, as ROS induced by PDT also seemed playing an essential role. The NIR-induced ROS could attack mitochondrial transmembrane potentials (MTPs), then promote mitochondrial reactive oxygen species (mitoROS) production. Meanwhile, mitochondrial damage dramatically changed the expression of anti-apoptotic protein (Bcl-2) and pro-apoptotic protein (Bax). Since that, mitochondrial permeability transition pore (mPTP) was opened, followed by inducing more cytochrome c (Cyto C) releasing from mitochondria into cytosol, and finally activated caspase-9/caspase-3-depended cell apoptosis pathway. Our in vivo data also showed that HMON@CuS/Gd exhibited good fluorescence (FL) imaging (wrapping fluorescent agent), enhanced T1 imaging under magnetic resonance imaging (MRI) and infrared thermal (IRT) imaging capacities. Guided by FL/MRI/IRT trimodal imaging, HMON@CuS/Gd could selectively cause mild photo-therapy at cancer region, efficiently inhibit the growth of GC cells without evident systemic toxicity in vivo. CONCLUSION: HMON@CuS/Gd could serve as a promising multifunctional nanotheranostic platform and as a cancer photo-therapy agent through inducing mitochondrial dysfunction on GC.

CuS-NiS2 nanomaterials for MRI guided phototherapy of gastric carcinoma via triggering mitochondria-mediated apoptosis and MLKL/CAPG-mediated necroptosis.

Gastric carcinoma is one of the most lethal malignant tumors. As part of our long-term efforts on seeking effective diagnosis and therapeutic strategies of gastric cancer, we present herein novel ternary copper-based chalcogenide nanoplatform CuS-NiS2 nanomaterials with outstanding photothermal (PT)/photodynamic (PD) property that could effectively suppress human gastric cancer in vitro and in vivo without obvious side effects. We revealed that CuS-NiS2 induced reactive oxygen species (ROS) generation, leading to apoptosis through Bcl-2/Bax pathway of human gastric cancer cells under 808 nm near-infrared (NIR) irradiation. In addition, we also confirmed that the combination of CuS-NiS2 and 808 nm NIR laser treatment triggered necroptosis by regulating the novel pathway MLKL/CAPG of human gastric cancer cells. Moreover, the CuS-NiS2 exhibited excellent contrast enhancement according to magnetic resonance imaging (MRI). Taken together, we reported new ternary copper-based chalcogenide nanomaterials CuS-NiS2, which could be successfully applied for MRI-guided PT/PD therapy of gastric carcinoma through mitochondria-mediated apoptosis and MLKL/CAPG-mediated necroptosis.

Hollow Mesoporous Tantalum Oxide Based Nanospheres for Triple Sensitization of Radiotherapy.

Radiotherapy (RT) is one of the most widely used cancer treatments in the clinical setting, while hypoxia-associated resistance often occurs. Herein, a PEGylated TaOx-based oxygen-carrying nanoplatform was constructed for triple sensitizing tumor radiotherapy. The high-Z element based hollow mesoporous TaOx nanospheres were prepared following the in situ growth of ultrasmall CuS nanocrystals and then packaged with O2-saturated perfluoropentane (PFP). NIR laser-triggered mild hyperthermia would lead to the increase of intratumoral blood flow, together with the release of O2, the radiotherapeutic efficiency would be enhanced. Alternatively, radiant energy would be deposited inside the tumor by the Ta element, therefore triple sensitization of radiotherapy could be achieved. The in vivo studies showed that the as-prepared nanospheres could achieve almost total inhibition of tumor growth without obvious side effects, which provides new possibilities for multisensitizing tumor radiotherapy.

CuS-MnS2 nano-flowers for magnetic resonance imaging guided photothermal/photodynamic therapy of ovarian cancer through necroptosis.

With a high incidence and high mortality rate, ovarian cancer presents a challenge for clinical practice. It is thus extremely urgent to investigate new diagnosis and therapy methods for the treatment of ovarian cancer. Ternary copper-based chalcogenide nanomaterials are attractive owing to their near infrared (NIR) response for cancer theranostic fields. However, improving the theranostic efficiency of these nanomaterials is challenging. Herein, CuS-MnS2 nano-flowers were easily synthesized and under NIR irradiation exhibited a relatively high photothermal conversion efficiency of 67.5% and a simultaneous reactive oxygen species (ROS) generation effect. Owing to these outstanding photothermal/photodynamic effects, excellent tumor ablation results could be achieved by the combined use of CuS-MnS2 nano-flowers and 808 nm NIR laser treatments. The main anticancer mechanism of CuS-MnS2 nano-flowers + NIR was likely necroptosis. In addition, the nano-flowers showed remarkable contrast enhancement according to magnetic resonance imaging (MRI). These CuS-MnS2 nano-flowers could thus serve as a promising multifunctional nanotheranostic agent for MRI and as a photothermal/photodynamic cancer therapy agent through necroptosis.

Multifunctional NIR-responsive poly(vinylpyrrolidone)-Cu-Sb-S nanotheranostic agent for photoacoustic imaging and photothermal/photodynamic therapy.

Ternary copper-based chalcogenide nanomaterials have become rather attractive due to the near-infrared (NIR) response in cancer theranostic fields. However, it is still challenging to further improve the theranostic efficiency of these nanomaterials. Herein, Cu-Sb-S nanoparticles (NPs) around 24 nm are synthesized facilely and functionalized with poly(vinylpyrrolidone) (PVP). Under the NIR irradiation, the resultant PVP-Cu-Sb-S NPs exhibit a relatively high photothermal conversion efficiency of 53.16% and a simultaneous reactive oxygen species (ROS) generation effect. Due to these outstanding photothermal/photodynamic effects, excellent tumor ablation results can be achieved by the combination of PVP-Cu-Sb-S NPs and 808 nm NIR laser treatments without obvious side effect. In addition, they show remarkable contrast enhancement according to in vitro and in vivo photoacoustic (PA) imaging. These PVP-Cu-Sb-S NPs could be served as a multifunctional nanotheranostic agent for PA imaging, photothermal/photodynamic cancer therapy. STATEMENT OF SIGNIFICANCE: Highly theranostic efficiency ternary copper-based chalcogenide nanomaterials has not been fully developed yet. Herein we report the PVP-Cu-Sb-S nanoparticles (NPs) with relatively high photothermal efficiency, simultaneous reactive oxygen species generation effect and photoacoustic imaging capability. The photothermal conversion efficiency of PVP-Cu-Sb-S NPs is higher than most of copper-based chalcogenide nanomaterials reported before. These findings provide a new kind of ternary copper-based chalcogenide with an enhanced theranostic effect, which could be served as a promising multifunctional nanotheranostic agent in the field of biomedical application.