The Parkinson's disease risk gene cathepsin B promotes fibrillar alpha-synuclein clearance, lysosomal function and glucocerebrosidase activity in dopaminergic neurons.

Background: Variants in the CTSB gene encoding the lysosomal hydrolase cathepsin B (catB) are associated with increased risk of Parkinson's disease (PD). However, neither the specific CTSB variants driving these associations nor the functional pathways that link catB to PD pathogenesis have been characterized. CatB activity contributes to lysosomal protein degradation and regulates signaling processes involved in autophagy and lysosome biogenesis. Previous in vitro studies have found that catB can cleave monomeric and fibrillar alpha-synuclein, a key protein involved in the pathogenesis of PD that accumulates in the brains of PD patients. However, truncated synuclein isoforms generated by catB cleavage have an increased propensity to aggregate. Thus, catB activity could potentially contribute to lysosomal degradation and clearance of pathogenic alpha synuclein from the cell, but also has the potential of enhancing synuclein pathology by generating aggregation-prone truncations. Therefore, the mechanisms linking catB to PD pathophysiology remain to be clarified. Methods: Here, we conducted genetic analyses of the association between common and rare CTSB variants and risk of PD. We then used genetic and pharmacological approaches to manipulate catB expression and function in cell lines and induced pluripotent stem cell-derived dopaminergic neurons and assessed lysosomal activity and the handling of aggregated synuclein fibrils. Results: We first identified specific non-coding variants in CTSB that drive the association with PD and are linked to changes in brain CTSB expression levels. Using iPSC-derived dopaminergic neurons we then find that catB inhibition impairs autophagy, reduces glucocerebrosidase (encoded by GBA1) activity, and leads to an accumulation of lysosomal content. Moreover, in cell lines, reduction of CTSB gene expression impairs the degradation of pre-formed alpha-synuclein fibrils, whereas CTSB gene activation enhances fibril clearance. Similarly, in midbrain organoids and dopaminergic neurons treated with alpha-synuclein fibrils, catB inhibition or knockout potentiates the formation of inclusions which stain positively for phosphorylated alpha-synuclein. Conclusions: The results of our genetic and functional studies indicate that the reduction of catB function negatively impacts lysosomal pathways associated with PD pathogenesis, while conversely catB activation could promote the clearance of pathogenic alpha-synuclein.

Novel 1,2,4-triazoles as selective carbonic anhydrase inhibitors showing ancillary anticathepsin B activity.

Background: Exploration of the multi-target approach considering both human carbonic anhydrase (hCA) IX and XII and cathepsin B is a promising strategy to target cancer. Methodology & Results: 22 novel 1,2,4-triazole derivatives were synthesized and evaluated for their inhibition efficacy against hCA I, II, IX, XII isoforms and cathepsin B. The compounds demonstrated effective inhibition against hCA IX and/or XII isoforms with considerable selectivity over off-target hCA I/II. All compounds presented significant anticathepsin B activities at a low concentration of 10-7 M and in vitro results were also supported by the molecular modeling studies. Conclusion: Insights of present study can be utilized in the rational design of effective and selective hCA IX and XII inhibitors capable of inhibiting cathepsin B.

Gastric cancer prognosis: unveiling autophagy-related signatures and immune infiltrates.

Background: Autophagy played a crucial regulatory role in tumor initiation and progression. Therefore, we aimed to comprehensively analyze autophagy-related genes (ARGs) in gastric cancer, focusing on their expression, prognostic value, and potential functions. Methods: The gastric cancer gene chip datasets (GSE79973 and GSE54129) were collected from the Gene Expression Omnibus (GEO) database. Subsequently, the Limma package was employed to identify differentially expressed genes (DEGs) between the normal and disease groups. The selected ARGs were further authenticated using the Human Protein Atlas (HPA) database, The Cancer Genome Atlas (TCGA) database, and GSE19826 database. Results: A total of 15 autophagy-related DEGs, eight of which were upregulated [FKBP1A, IL24, PEA15, HSP90AB1, cathepsin B (CTSB), ITGB1, SPHK1, HIF1A], while seven were downregulated (DAPK2, EIF2AK3, FKBP1B, PTK6, NKX2-3, NFE2L2, PRKCD). Analysis revealed that CTSB was specifically associated with the prognosis of gastric cancer patients. Gene set enrichment analysis (GSEA) showcased a significant enrichment of CTSB-related genes within immune-related pathways. Moreover, correlation analysis demonstrated a clear association between the expression of CTSB and immune infiltration. The upregulation of CTSB in gastric cancer was linked to poor survival and increased immune infiltration. Conclusions: We conjectured that CTSB likely played a critical role in regulating immunity and autophagy in gastric cancer.

Design, synthesis, and biological evaluation of cathepsin B cleavage albumin-binding SN38 prodrug in breast cancer.

Here, we introduce a novel and effective approach utilizing a cathepsin B cleavage albumin-binding SN38 prodrug specifically designed for the treatment of metastatic breast cancer. Termed Mal-va-mac-SN38, our prodrug exhibits a unique ability to rapidly and covalently bind with endogenous albumin, resulting in the formation of HSA-va-mac-SN38. This prodrug demonstrates exceptional stability in human plasma. Importantly, HSA-va-mac-SN38 showcases an impressive enhancement in cellular uptake by 4T1 breast cancer cells, primarily facilitated through caveolin-mediated endocytosis. Intriguingly, the release of the active SN38, is triggered by the enzymatic activity of cathepsin B within the lysosomal environment. In vivo studies employing a lung metastasis 4T1 breast cancer model underscore the potency of HSA-va-mac-SN38. Histological immunohistochemical analyses further illuminate the multifaceted impact of our prodrug, showcasing elevated levels of apoptosis, downregulated expression of matrix metalloproteinases, and inhibition of angiogenesis, all critical factors contributing to the anti-metastatic effect observed. Biodistribution studies elucidate the capacity of Mal-va-mac-SN38 to augment tumor accumulation through covalent binding to serum albumin, presenting a potential avenue for targeted therapeutic interventions. Collectively, our findings propose a promising therapeutic avenue for metastatic breast cancer, through the utilization of a cathepsin B-cleavable albumin-binding prodrug.

PDX proteins from Arabidopsis thaliana as novel substrates of cathepsin B: implications for vitamin B6 biosynthesis regulation.

Vitamin B6 is a critical molecule for metabolism, development, and stress sensitivity in plants. It is a cofactor for numerous biochemical reactions, can serve as an antioxidant, and has the potential to increase tolerance against both biotic and abiotic stressors. Due to the importance of vitamin B6 , its biosynthesis is likely tightly regulated. Plants can synthesize vitamin B6 de novo via the concerted activity of Pyridoxine Biosynthesis Protein 1 (PDX1) and PDX2. Previously, PDX proteins have been identified as targets for ubiquitination, indicating they could be marked for degradation by two highly conserved pathways: the Ubiquitin Proteasome Pathway (UPP) and the autophagy pathway. Initial experiments show that PDXs are in fact degraded, but surprisingly, in a ubiquitin-independent manner. Inhibitor studies pointed toward cathepsin B, a conserved lysosomal cysteine protease, which is implicated in both programed cell death and autophagy in humans and plants. In plants, cathepsin Bs are poorly described, and no confirmed substrates have been identified. Here, we present PDX proteins from Arabidopsis thaliana as interactors and substrates of a plant Cathepsin B. These findings not only describe a novel cathepsin B substrate in plants, but also provide new insights into how plants regulate de novo biosynthesis of vitamin B6 .

Enzyme-responsive design combined with photodynamic therapy for cancer treatment.

Photodynamic therapy (PDT) is a noninvasive cancer treatment that has garnered significant attention in recent years. However, its application is still hampered by certain limitations, such as the hydrophobicity and low targeting of photosensitizers (PSs) and the hypoxia of the tumor microenvironment. Nevertheless, the fusion of enzyme-responsive drugs with PDT offers novel solutions to overcome these challenges. Utilizing the attributes of enzyme-responsive drugs, PDT can deliver PSs to the target site and selectively release them, thereby enhancing therapeutic outcomes. In this review, we spotlight recent advances in enzyme-responsive materials for cancer treatment and primarily delineate their application in combination with PDT.

Role of Cathepsin B Expression in Oral Squamous Cell Carcinoma: A Comprehensive Review.

This comprehensive review delves into the intricate landscape of oral squamous cell carcinoma (OSCC) by examining the role of cathepsin B expression in its pathogenesis. OSCC, a prevalent and clinically significant oral malignancy, poses a considerable global health burden, necessitating a thorough exploration of its underlying molecular mechanisms. Cathepsin B, a lysosomal cysteine protease, emerges as a critical player in OSCC, influencing tumour initiation, invasion, and metastasis. The review begins with a brief overview of OSCC, emphasizing its epidemiological and clinical features, followed by exploring the significance of studying cathepsin B expression in this context. In the manuscript, the structure and function of cathepsin B are elucidated, providing a foundation for understanding its aberrant expression in OSCC. Clinical studies revealing correlations with tumour grade and stage, along with prognostic significance, are scrutinized, offering insights into the potential diagnostic and prognostic utility of cathepsin B. The biological functions of cathepsin B in OSCC, including its impact on tumour invasion and modulation of apoptosis, are comprehensively discussed. The Therapeutic Implications section explores targeting cathepsin B as a potential strategy, emphasizing the need for future research to overcome associated challenges. In the Conclusion section, the review synthesizes key findings, delineates implications for future research, and highlights the potential impact of cathepsin B on OSCC diagnosis and treatment, contributing to the ongoing efforts to advance our understanding of this complex malignancy, which is associated with a high mortality rate and improve clinical outcomes.

Syntaxin17 Restores Lysosomal Function and Inhibits Pyroptosis Caused by Acinetobacter baumannii.

Acinetobacter baumannii (A. baumannii) causes autophagy flux disorder by degrading STX17, resulting in a serious inflammatory response. It remains unclear whether STX17 can alter the inflammatory response process by controlling autolysosome function. This study aimed to explore the role of STX17 in the regulation of pyroptosis induced by A. baumannii. Our findings indicate that overexpression of STX17 enhances autophagosome degradation, increases LAMP1 expression, reduces Cathepsin B release, and improves lysosomal function. Conversely, knockdown of STX17 suppresses autophagosome degradation, reduces LAMP1 expression, augments Cathepsin B release, and accelerates lysosomal dysfunction. In instances of A. baumannii infection, overexpression of STX17 was found to improve lysosomal function and reduce the expression of mature of GSDMD and IL-1ß, along with the release of LDH, thus inhibiting pyroptosis caused by A. baumannii. Conversely, knockdown of STX17 led to increased lysosomal dysfunction and further enhanced the expression of mature of GSDMD and IL-1ß, and increased the release of LDH, exacerbating pyroptosis induced by A. baumannii. These findings suggest that STX17 regulates pyroptosis induced by A. baumannii by modulating lysosomal function.

Cathepsin B degrades RbcL during freezing-induced programmed cell death in Arabidopsis.

KEY MESSAGE: Cathepsin B plays an important role that degrades the Rubisco large subunit RbcL in freezing stress. Programmed cell death (PCD) has been well documented in both development and in response to environmental stresses in plants, however, PCD induced by freezing stress and its molecular mechanisms remain poorly understood. In the present study, we characterized freezing-induced PCD and explored its mechanisms in Arabidopsis. PCD induced by freezing stress was similar to that induced by other stresses and senescence in Arabidopsis plants with cold acclimation. Inhibitor treatment assays and immunoblotting indicated that cathepsin B mainly contributed to increased caspase-3-like activity during freezing-induced PCD. Cathepsin B was involved in freezing-induced PCD and degraded the large subunit, RbcL, of Rubisco. Our results demonstrate an essential regulatory mechanism of cathepsin B for Rubisco degradation in freezing-induced PCD, improving our understanding of freezing-induced cell death and nitrogen and carbohydrate remobilisation in plants.

Cathepsin B-Activated PET Tracer for In Vivo Tumor Imaging.

Cathepsin B, a lysosomal protease, is considered as a crucial biomarker for tumor diagnosis and treatment as it is overexpressed in numerous cancers. A stimulus-responsive SF scaffold has been reported to detect the activity of a variety of tumor-associated enzymes. In this work, a small-molecule PET tracer ([68Ga]NOTA-SF-CV) was developed by combining an SF scaffold with a cathepsin B-specific recognition substrate Cit-Val. Upon activation by cathepsin B, [68Ga]NOTA-SF-CV could form the cyclization product in a reduction environment, resulting in reduced hydrophilicity. This unique property could effectively prevent exocytosis of the tracer in cathepsin B-overexpressing tumor cells, leading to prolonged retention and amplified PET imaging signal. Moreover, [68Ga]NOTA-SF-CV had great targeting specificity to cathepsin B. In vivo microPET imaging results showed that [68Ga]NOTA-SF-CV was able to effectively visualize the expression level of cathepsin B in various tumors. Hence, [68Ga]NOTA-SF-CV may be served as a potential tracer for diagnosing cathepsin B-related diseases.

Mono-amino acid linkers enable highly potent small molecule-drug conjugates by conditional release.

The endosome cleavable linkers have been widely employed by antibody-drug conjugates and small molecule-drug conjugates (SMDCs) to control the accurate release of payloads. An effective linker should provide stability in systemic circulation but efficient payload release at its targeted tumor sites. This conflicting requirement always leads to linker design with increasing structural complexity. Balance of the effectiveness and structural complexity presents a linker design challenge. Here, we explored the possibility of mono-amino acid as so far the simplest cleavable linker (X-linker) for SMDC-based auristatin delivery. Within a diverse set of X-linkers, the SMDCs differed widely in bioactivity, with one (Asn-linker) having significantly improved potency (IC50 = 0.1 nM) and fast response to endosomal cathepsin B cleavage. Notably, this SMDC, once grafted with effector protein fragment crystallizable (Fc), demonstrated a profound in vivo therapeutic effect in aspects of targetability, circulation half-life (t1/2 = 73 h), stability, and anti-tumor efficacy. On the basis of these results, we believe that this mono-amino acid linker, together with the new SMDC-Fc scaffold, has significant potential in targeted delivery application.

Human ß-Defensin 3 Inhibition of P. gingivalis LPS-Induced IL-1ß Production by BV-2 Microglia through Suppression of Cathepsins B and L.

Cathepsin B (CatB) is thought to be essential for the induction of Porphyromonas gingivalis lipopolysaccharide (Pg LPS)-induced Alzheimer's disease-like pathologies in mice, including interleukin-1ß (IL-1ß) production and cognitive decline. However, little is known about the role of CatB in Pg virulence factor-induced IL-1ß production by microglia. We first subjected IL-1ß-luciferase reporter BV-2 microglia to inhibitors of Toll-like receptors (TLRs), IκB kinase, and the NLRP3 inflammasome following stimulation with Pg LPS and outer membrane vesicles (OMVs). To clarify the involvement of CatB, we used several known CatB inhibitors, including CA-074Me, ZRLR, and human ß-defensin 3 (hBD3). IL-1ß production in BV-2 microglia induced by Pg LPS and OMVs was significantly inhibited by the TLR2 inhibitor C29 and the IκB kinase inhibitor wedelolactonne, but not by the NLRPs inhibitor MCC950. Both hBD3 and CA-074Me significantly inhibited Pg LPS-induced IL-1ß production in BV-2 microglia. Although CA-074Me also suppressed OMV-induced IL-1ß production, hBD3 did not inhibit it. Furthermore, both hBD3 and CA-074Me significantly blocked Pg LPS-induced nuclear NF-κB p65 translocation and IκBα degradation. In contrast, hBD3 and CA-074Me did not block OMV-induced nuclear NF-κB p65 translocation or IκBα degradation. Furthermore, neither ZRLR, a specific CatB inhibitor, nor shRNA-mediated knockdown of CatB expression had any effect on Pg virulence factor-induced IL-1ß production. Interestingly, phagocytosis of OMVs by BV-2 microglia induced IL-1ß production. Finally, the structural models generated by AlphaFold indicated that hBD3 can bind to the substrate-binding pocket of CatB, and possibly CatL as well. These results suggest that Pg LPS induces CatB/CatL-dependent synthesis and processing of pro-IL-1ß without activation of the NLRP3 inflammasome. In contrast, OMVs promote the synthesis and processing of pro-IL-1ß through CatB/CatL-independent phagocytic mechanisms. Thus, hBD3 can improve the IL-1ß-associated vicious inflammatory cycle induced by microglia through inhibition of CatB/CatL.

Negative Regulation of Cathepsins by ß-Amyloid.

Genome wide association study (GWAS) uncovered Alzheimer's disease (AD) risk genes linked to the endo-lysosomal pathway. This pathway seems to be the gateway of protein aggregates, such as tau and α-synuclein, to the cytoplasm. Furthermore, we and others reported that the amyloid precursor protein (APP) C99 is predominantly processed by γ-secretase in the endo-lysosomal compartments, and ß-amyloid (Aß) peptides are enriched in the same subcellular loci. While the role(s) of APP/Aß in the endo-lysosomal pathway has not been fully established, a recent study reported that Aß, in particular Aß42, inhibits cathepsin D (CTSD) activity. Here, we show using a cell-free in vitro assay that Aß42 also blocks cathepsin B (CTSB) activity. Furthermore, we uncovered that the autocatalytic processing (i.e., conversion of single chain to heavy/light chains) of CTSB and CTSD is accelerated in APP-deficient cells compared with wild-type controls. Taken together, our findings further support the negative regulation of cathepsins by Aß.

Cathepsin B Responsive Peptide-Purpurin Conjugates Assembly-Initiated in Situ Self-Aggregation for Cancer Sonotheranostics.

Sonodynamic therapy (SDT) was hampered by the sonosensitizers with low bioavailability, tumor accumulation, and therapeutic efficiency. In situ responsive sonosensitizer self-assembly strategy may provide a promising route for cancer sonotheranositics. Herein, an intelligent sonotheranostic peptide-purpurin conjugate (P18-P) is developed that can self-assemble into supramolecular structures via self-aggregation triggered by rich enzyme cathepsin B (CTSB). After intravenous injection, the versatile probe could achieve deep tissue penetration because of the penetration sequence of P18-P. More importantly, CTSB-triggered self-assembly strongly prolonged retention time, amplified photoacoustic imaging signal for sensitive CTSB detection, and boosted reactive oxygen species for advanced SDT, evoking specific CTSB responsive sonotheranostics. This peptide-purpurin conjugate may serve as an efficient sonotheranostic platform for the early diagnosis of CTSB activity and effective cancer therapy.

Chitosan-coated nanostructured lipid carriers for effective brain delivery of Tanshinone IIA in Parkinson's disease: interplay between nuclear factor-kappa ß and cathepsin B.

Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder associated with increased oxidative stress, the underlying vital process contributing to cell death. Tanshinone IIA (TAN) is a phytomedicine with a documented activity in treating many CNS disorders, particularly PD owing to its unique anti-inflammatory and antioxidant effect. However, its clinical utility is limited by its poor aqueous solubility, short half-life, and hence low concentration reaching targeted cells. This work aimed to develop a biocompatible chitosan-coated nanostructured lipid carriers (CS-NLCs) for effective brain delivery of TAN for PD management. The proposed nanosystem was successfully prepared using a simple melt-emulsification ultra-sonication method, optimized and characterized both in vitro and in vivo in a rotenone-induced PD rat model. The developed TAN-loaded CS-NLCs (CS-TAN-NLCs) showed good colloidal properties (size ≤ 200 nm, PDI ≤ 0.2, and ζ-potential + 20 mV) and high drug entrapment efficiency (> 97%) with sustained release profile for 24 h. Following intranasal administration, CS-TAN-NLCs succeeded to achieve a remarkable antiparkinsonian and antidepressant effect in diseased animals compared to both the uncoated TAN-NLCs and free TAN suspension as evidenced by the conducted behavioral tests and improved histopathological findings. Furthermore, biochemical evaluation of oxidative stress along with inflammatory markers, nuclear factor-kabba ß (NF-Kß) and cathepsin B further confirmed the potential of the CS-TAN-NLCs in enhancing brain delivery and hence the therapeutic effect of TAN of treatment of PD. Accordingly, CS-TAN-NLCs could be addressed as a promising nano-platform for the effective management of PD.

1,2,3-Triazole-based esters and carboxylic acids as nonclassical carbonic anhydrase inhibitors capable of cathepsin B inhibition.

Herein, we report the design and synthesis of a library of 28 new 1,2,3-triazole derivatives bearing carboxylic acid and ester moieties as dual inhibitors of carbonic anhydrase (CA) and cathepsin B enzymes. The synthesised compounds were assayed in vitro for their inhibition potential against four human CA (hCA) isoforms, I, II, IX and XII. The carboxylic acid derivatives displayed low micromolar inhibition against hCA II, IX and XII in contrast to the ester derivatives. Most of the target compounds showed poor inhibition against the hCA I isoform. 4-Fluorophenyl appended carboxylic acid derivative 6c was found to be the most potent inhibitor of hCA IX and hCA XII with a KI value of 0.7 µM for both the isoforms. The newly synthesised compounds showed dual inhibition towards CA as well as cathepsin B. The ester derivatives exhibited higher % inhibition at 10-7 M concentration as compared with the corresponding carboxylic acid derivatives against cathepsin B. The results from in silico studies of the target compounds with the active site of cathepsin B were found in good correlation with the in vitro results. Moreover, two compounds, 5i and 6c, showed cytotoxic activity against A549 lung cancer cells, with IC50 values lower than 100 µM.

Reactions of Medicinal Gold Compounds with Cathepsin B Explored through Electrospray Mass Spectrometry Measurements.

Medicinal gold compounds, a novel class of potential anticancer drugs, are believed to produce their pharmacological effects mainly through direct gold binding to protein targets at the level of solvent exposed cysteine (or selenocysteine) residues. We have explored therein the reactions of a panel of seven representative gold compounds with the cysteine protease cathepsin B according to an established ESI MS approach. Detailed information on the mode of protein binding of these gold compounds is gained; notably, quite distinct patterns of cathepsin B metalation have emerged from these studies. It is shown that panel gold compounds interact preferentially, often exclusively, with the free cysteine located in the active site of the enzyme.

Trichinella spiralis cathepsin B bound and degraded host's intestinal type I collagen.

Trichinellosis is a zoonotic parasitic disease that poses threats to human health, the meat industry, food safety, and huge financial losses. The critical stage of Trichinella spiralis (T. spiralis) infection is the invasion of intestinal larvae into the host's intestinal epithelial cells (IECs). T. spiralis Cathepsin B (TsCB) specifically interacts with IECs to facilitate the invasion of larvae. This study aims to look at how TsCB affects mouse IECs. TsCB was successfully cloned, expressed, and characterized, demonstrating its natural cysteine protease hydrolysis activity. A total of 140 proteins that interact with rTsCB were identified by GST pull-down combined with LC-MS/MS, including type I collagen, an essential component of the host's intestinal epithelial barrier system and intimately related to intestinal epithelial damage. TsCB transcription and expression levels rise, whereas type I collagen in the host's intestinal mucosa declines when the T. spiralis larvae invaded. Besides, it was discovered that TsCB bound to and degraded type I collagen of the host's intestine. This research can serve as a foundation for clarifying how T. spiralis invades the host's intestinal barrier and might provide information on potential targets for the creation of novel treatments to treat parasite illnesses.

Extracellular vesicle proteome unveils cathepsin B connection to Alzheimer's disease pathogenesis.

Extracellular vesicles (EVs) are membrane vesicles that are released extracellularly and considered to be implicated in the pathogenesis of neurodegenerative diseases including Alzheimer's disease. Here, CSF EVs of 16 ATN-classified cases were subjected to quantitative proteome analysis. In these CSF EVs, levels of 11 proteins were significantly altered during the ATN stage transitions (P < 0.05 and fold-change > 2.0). These proteins were thought to be associated with Alzheimer's disease pathogenesis and represent candidate biomarkers for pathogenic stage classification. Enzyme-linked immunosorbent assay analysis of CSF and plasma EVs revealed altered levels of cathepsin B (CatB) during the ATN transition (seven ATN groups in validation set, n = 136). The CSF and plasma EV CatB levels showed a negative correlation with CSF amyloid-ß42 concentrations. This proteomic landscape of CSF EVs in ATN classifications can depict the molecular framework of Alzheimer's disease progression, and CatB may be considered a promising candidate biomarker and therapeutic target in Alzheimer's disease amyloid pathology.

Attenuation of pro-tumorigenic senescent secretory phenotype by StN, a novel derivative of stevioside, potentiates its inhibitory activity on hepatocellular carcinoma.

Ent-13-Hydroxy-15-kaurene-19-acid N-Methylpiperazine Ethyl Ester (StN) is a novel derivative of the natural diterpene stevioside isolated from Stevia rebaudiana (Bertoni). In this study, we examined the effects of StN against hepatocellular carcinoma (HCC) in vitro and in vivo as well as its anticancer mechanisms by inhibiting proliferation and regulating the senescence-associated secretory phenotype (SASP). We showed that StN significantly inhibited HCC cell proliferation by inducing cellular senescence, as observed by increased senescence-associated ß-galactosidase activity and cell cycle arrest. Mechanistically, StN impaired lysosomal stability and triggered the release of cathepsin B from the lysosomes into the nucleus where it promoted DNA damage. Cathepsin B-mediated DNA damage contributed to cellular senescence triggered by StN. Meanwhile, StN transcriptionally suppressed multiple pro-inflammatory SASP components, including IL-6, IL-1α, IL-1ß, and IL-8, resulting in the reduction of pro-tumorigenic impact of SASP. Further study revealed that StN inactivated NF-κB and PI3K/Akt signaling, which significantly accounted for its inhibition on the SASP factors. In HCC xenograft mice, administration of StN significantly suppressed tumor growth, while no significant toxicity was detected. This study demonstrates a novel mechanism that suppressing the SASP by StN in senescent cells potentiates its anticancer efficacy, thus defining a potential compound for cancer treatment.