Autophagy-Activated Self-reporting Photosensitizer Promoting Cell Mortality in Cancer Starvation Therapy

Development of Novel β-Carboline/Furylmalononitrile Hybrids as Type I/II Photosensitizers with Chemo-Photodynamic Therapy and Minimal Toxicity

Chemo-photodynamic therapy is a treatment method that combines chemotherapy and photodynamic therapy and has demonstrated significant potential in cancer treatment. However, the development of chemo-photodynamic therapeutic agents with fewer side effects still poses a challenge. Herein, we designed and synthesized a novel series of β-carboline/furylmalononitrile hybrids 10a-i and evaluated their chemo-photodynamic therapeutic effects. Most of the compounds were photodynamically active and exhibited cytotoxic effects in four cancer cells. In particular, 10f possessed type-I/II photodynamic characteristics, and its 1O2 quantum yield increased by 3-fold from pH 7.4 to 4.5. Most interestingly, 10f exhibited robust antiproliferative effects by tumor-selective cytotoxicities and hypoxic-overcoming phototoxicities. In addition, 10f generated intracellular ROS and induced hepatocellular apoptosis, mitochondrial damage, and autophagy. Finally, 10f demonstrated extremely low acute toxicity (LD50 = 1415 mg/kg) and a high tumor-inhibitory rate of 80.5% through chemo-photodynamic dual therapy. Our findings may provide a promising framework for the design of new photosensitizers for chemo-photodynamic therapy.

Cancer-cell-specific Self-Reporting Photosensitizer for Precise Identification and Ablation of Cancer Cells

Cancer-cell-specific fluorescent photosensitizers (PSs) are highly desired molecular tools for cancer ablation with minimal damage to normal cells. However, such PSs that can achieve cancer specification and ablation and a self-reporting manner concurrently are rarely reported and still an extremely challenging task. Herein, we have proposed a feasible strategy and conceived a series of fluorescent PSs based on simple chemical structures for identifying and killing cancer cells as well as monitoring the photodynamic therapy (PDT) process by visualizing the change of subcellular localization. All of the constructed cationic molecules could stain mitochondria in cancer cells, identify cancer cells specifically, and monitor cancer cell viability. Among these, IVP-Br has the strongest ability to produce ROS, which serves as a potent PS for specific recognition and killing of cancer cells. IVP-Br could translocate from mitochondria to the nucleolus during PDT, self-reporting the entire therapeutic process. Mechanism study confirms that IVP-Br with light irradiation causes cancer cell ablation via inducing cell cycle arrest, cell apoptosis, and autophagy. The efficient ablation of tumor through PDT induced by IVP-Br has been confirmed in the 3D tumor spheroid chip. Particularly, IVP-Br could discriminate cancer cells from white blood cells (WBCs), exhibiting great potential to identify circulating tumor cells (CTCs).

Glucose dysregulation promotes oncogenesis in human bladder cancer by regulating autophagy and YAP1/TAZ expression

Glucose dysregulation is strongly correlated with cancer development, and cancer is prevalent in patients with Type 2 diabetes (T2D). We aimed to elucidate the mechanism underlying autophagy in response to glucose dysregulation in human bladder cancer (BC). 220 BC patients were included in this retrospective study. The expression of YAP1, TAZ and AMPK, EMT-associated markers, and autophagy marker proteins was analysed by immunohistochemistry, western blotting, and quantitative real-time PCR (qPCR). Further, T24 and UMUC-3 BC cells were cultured in media with different glucose concentrations, and the expression of YAP1, TAZ, AMPK and EMT-associated markers, and autophagy marker proteins was analysed by western blotting and qPCR. Autophagy was observed by immunofluorescence and electron microscopy. BC cell viability was tested using MTT assays. A xenograft nude mouse model of diabetes was used to evaluate tumour growth, metastasis and survival. A poorer pathologic grade and tumour-node-metastasis stage were observed in patients with BC with comorbid T2D than in others with BC. YAP1 and TAZ were upregulated in BC samples from patients with T2D. Mechanistically, high glucose (HG) promoted BC progression both in vitro and in vivo and inhibited autophagy. Specifically, various autophagy marker proteins and AMPK were negatively regulated under HG conditions and correlated with YAP1 and TAZ expression. These results demonstrate that HG inhibits autophagy and promotes cancer development in BC. YAP1/TAZ/AMPK signalling plays a crucial role in regulating glucose dysregulation during autophagy. Targeting these effectors exhibits therapeutic significance and can serve as prognostic markers in BC patients with T2D.

Engineering Diselenide-IR780 Homodimeric Nanoassemblies with Enhanced Photodynamic and Immunotherapeutic Effects for Triple-Negative Breast Cancer Treatment

Photodynamic therapy (PDT) has emerged as an efficient approach for non-invasive cancer treatment. However, organic small-molecule photosensitizers are often associated with defects in hydrophobicity, poor photostability, and aggregation-caused quenching, which limit their application. Usually, the carrier-assisted drug delivery system is a common strategy to solve the above obstacles, but additional carrier material could increase the risk of potential biological toxicity. The carrier-free drug delivery system with easy preparation and high drug-loading capability is proposed subsequently as a potential strategy to develop the clinical use of hydrophobic drugs. Herein, we rationally designed three IR780-based carrier-free nanosystems formed by carbon/disulfide/diselenide bond conjugated IR780-based homodimers. The IR780-based homodimers could self-assemble to form nanoparticles (DC-NP, DS-NP, DSe-NP) and exhibited higher reactive oxygen species generation capability and photostability than free IR780, in which DSe-NP with 808 nm laser irradiation performed best and resulted in the strongest cytotoxicity to 4T1 cells. Meanwhile, the glutathione consumption ability of DSe-NP boosted its PDT effect and then induced excessive oxidative stress of 4T1 cells, increasing antitumor efficacy by enhancing immunogenic cell death further. In tumor-bearing mice, DSe-NP displayed obvious tumor site accumulation, which obviously inhibited tumor growth and metastasis, and enhanced the immunological effect by effectively inducing dendritic cells to mature and activating T lymphocytes and natural killer cells. In summary, our study presented an IR780-based carrier-free nanodelivery system for a combination of PDT and immunity therapy and established expanding the application of organic small-molecule photosensitizers by an approach of carrier-free drug delivery system.