Z-FL-COCHO, a cathepsin S inhibitor, enhances oxaliplatin-induced apoptosis through upregulation of Bim expression

Correlation between cathepsins and the likelihood of renal cancer: a Mendelian randomization study

BACKGROUND

Previous studies have established a relationship between cathepsins and renal cancer. Nonetheless, the specific causal connection between the two factors continues to be ambiguous. The aim of this study is to evaluate the causal relationship between cathepsins and renal cancer via employing Mendelian randomization (MR).

METHODS

The summary data of genome-wide association study were used for univariable MR (UVMR), reverse MR, and multivariable MR (MVMR) analyses. The primary MR method used in this study was Inverse variance weighting.

RESULTS

UVMR analysis showed that cathepsin Z increased the overall risk of renal cancer and cathepsin F were observed increased the risk of clear cell renal cell carcinoma. Furthermore, the concentration of cathepsin S had a significant positive correlation with the risk of papillary renal cell carcinoma (pRCC), whereas that of cathepsin G was negatively correlated with the risk of pRCC. Reverse MR analysis showed that renal cancer reduced the concentration of cathepsin H. MVMR analysis showed that the concentration of cathepsin B had a significant positive correlation with overall risk of renal cancer and pRCC. In addition, a higher concentration of cathepsin S was significantly associated with an increased risk of pRCC.

CONCLUSION

This study confirmed a direct link between cathepsins and the risk of renal cancer. Specifically, cathepsin S has a significant positive correlation with the risk of pRCC. The findings of our research could provide significant contributions to both fundamental and clinical investigations pertaining to renal cancer. Key message What is already known on this topic? - Previous studies have suggested the role of some cathepsins in renal cancer occurrence and progression. However, the causal link between different cathepsins and renal cancer is unknown. What this study adds? - Our Mendelian randomization (MR) study revealed that the effects of different cathepsins on the risk of renal cancer. Remarkably, both univariable MR and multivariable MR demonstrated that the levels of cathepsin S increases the risk of papillary renal cell carcinoma. How this study might affect research, practice or policy? - The findings offer novel insights into the relationship between cathepsins and renal cancer, which may have implications for the prevention and management of renal cancer.

Roles of cathepsin S expression levels on the prognosis and tumour microenvironment in clear cell renal cell carcinoma

BACKGROUND

Increasing evidence suggests a link between the enzyme cathepsin S (CTSS) and tumour development. However, the potential involvement and molecular functions of CTSS in clear cell renal cell carcinoma (ccRCC) remain unclear.

METHODS

We downloaded original data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and integrated them using R. Kaplan-Meier plots of integrated expression scores were used to analyse survival outcomes. Additionally, we investigated mRNA expression, clinicopathological features, immune infiltrates, and single-cell sequencing analysis of CTSS in ccRCC. In vitro experiments were conducted with qRT-PCR and IHC staining.

RESULTS

CTSS transcriptomic and proteomic levels were higher in ccRCC than in para-cancerous tissues. Low CTSS expression was correlated with poor prognosis in patients with ccRCC. Our data demonstrated that the expression of CTSS was strongly correlated with immune cell infiltration levels and gene markers of immune cells, chemokines, and receptors. Single-cell sequencing analysis demonstrated that CTSS expression was detectable in monocytes/macrophages. Finally, certain chemicals were confirmed to affect CTSS expression.

CONCLUSION

Our findings indicate that CTSS offers promise as a prognostic biomarker and novel immune-related therapeutic target for ccRCC.

Advances in Cathepsin S Inhibition: Challenges and Breakthroughs in Drug Development

Cathepsin S (CatS) is a proteolytic enzyme and a member of the cysteine protease family of proteolytic enzymes. Cathepsins S, K, and L are particularly similar in terms of their amino acid sequences and interactions with substrates, and this has made it difficult to develop inhibitors with specificity for either CatS, CatK, or CatL. The involvement of CatS in various disease pathophysiologies (autoimmune disorders, cardiovascular diseases, cancer, etc.) has made it a very important target in drug development. Efforts have been made since the early 1990s to develop a specific CatS inhibitor without any major success. Following many failed efforts to develop an inhibitor for CatS, it was discovered that interactions with the amino acid residues at the S2 and S3 pockets of CatS are critical for the identification of CatS-specific inhibitors. Amino acid residues at these pockets have been the target of recent research focused on developing a non-covalent, reversible, and specific CatS inhibitor. Methods applied in the identification of CatS inhibitors include molecular modeling, in-vitro screening, and in-vivo studies. The molecular modeling process has proven to be very successful in the identification of CatS-specific inhibitors, with R05459072 (Hoffmann-La Roche) and LY3000328 (Eli Lilly Company) which has completed phase 1 clinical trials. CatS inhibitors identified from 2011 to 2023 with promising prospects are discussed in this article.

Lysosomal peptidases – Intriguing roles in cancer progression and neurodegeneration

Lysosomal peptidases are hydrolytic enzymes capable of digesting waste proteins that are targeted to lysosomes via endocytosis and autophagy. Besides intracellular protein catabolism, they play more specific roles in several other cellular processes and pathologies, either within lysosomes, upon secretion into the cell cytoplasm or extracellular space, or bound to the plasma membrane. In cancer, lysosomal peptidases are generally associated with disease progression, as they participate in crucial processes leading to changes in cell morphology, signaling, migration, and invasion, and finally metastasis. However, they can also enhance the mechanisms resulting in cancer regression, such as apoptosis of tumor cells or antitumor immune responses. Lysosomal peptidases have also been identified as hallmarks of aging and neurodegeneration, playing roles in oxidative stress, mitochondrial dysfunction, abnormal intercellular communication, dysregulated trafficking, and the deposition of protein aggregates in neuronal cells. Furthermore, deficiencies in lysosomal peptidases may result in other pathological states, such as lysosomal storage disease. The aim of this review was to highlight the role of lysosomal peptidases in particular pathological processes of cancer and neurodegeneration and to address the potential of lysosomal peptidases in diagnosing and treating patients.

Role of protein phosphatase 2A in kidney disease (Review)

Kidney disease affects millions of people worldwide and is a financial burden on the healthcare system. Protein phosphatase 2A (PP2A), which is involved in renal development and the function of ion-transport proteins, aquaporin-2 and podocytes, is likely to serve an important role in renal processes. PP2A is associated with the pathogenesis of a variety of different kidney diseases including podocyte injury, inflammation, tumors and chronic kidney disease. The current review aimed to discuss the structure and function of PP2A subunits in the context of kidney diseases. How dysregulation of PP2A in the kidneys causes podocyte death and the inactivation of PP2A in renal carcinoma tissues is discussed. Inhibition of PP2A activity prevents epithelial-mesenchymal transition and attenuates renal fibrosis, creating a favorable inflammatory microenvironment and promoting the initiation and progression of tumor pathogenesis. The current review also indicates that PP2A serves an important role in protection against renal inflammation. Understanding the detailed mechanisms of PP2A provides information that can be utilized in the design and application of novel therapeutics for the treatment and prevention of renal diseases.

miR-193a-5p as a promising therapeutic candidate in colorectal cancer by reducing 5-FU and Oxaliplatin chemoresistance by targeting CXCR4

Colorectal cancer (CRC) is one of the most common causes of cancer-related deaths worldwide. The role of microRNAs (miRNAs/miRs) as small (19-25 nucleotides in length) non-coding RNA molecules that modify gene expression has been shown in several types of cancer. 5-Fluorouracil (5-FU) and oxaliplatin (Ox) are two common chemotherapeutic agents used to treat cancer. The present study aimed to evaluate the expression levels of miR-193a-5p in CRC, and its effect on the C-X-C Motif Chemokine Receptor 4 (CXCR4) target gene alone and in combination with chemotherapeutic drugs, to determine its possible role in chemoresistance. CRC tissues and adjacent non-cancerous tissue were obtained from 67 patients who had undergone surgery to determine the expression levels of miR-193a-5p and CXCR4. Subsequently, qPCR and Western blotting were performed to determine the effect of miR-193a-5p and chemotherapy drugs on CXCR4. َAlso, MTT assay, and flow cytometry was performed to determine their role in cell viability and apoptosis. Besides, the relationship between miR-193a-5p and CXCR4 with patients' clinical features was investigated. The results of the present study showed that miR-193a-5p was significantly downregulated, whereas CXCR4 was significantly upregulated in tumor tissues obtained from patients with CRC compared with the adjacent non-tumor healthy controls. In addition, the upregulation of miR-193-5p reduced the expression levels of CXCR4, particularly in combination with 5-FU and OX. Besides, using rescue experiments, the present study showed that miR-193a-5p replacement was able to suppress CXCR4-induced CRC cell proliferation by directly targeting CXCR4. Furthermore, there was a significant association between miR-193a-5p and CXCR4 with certain clinicopathological characteristics, particularly with metastasis-related features. These results suggest that miR-193a-5p serves a tumor-suppressive function in CRC and can directly target CXCR4 and decrease its mRNA and protein expression levels. Additionally, miR-193a-5p in combination with 5-FU and Ox potentiated reducing CXR4 expression, which may reveal its contribution to tumor chemoresistance. In conclusion, miR-193-5p may be applicable as a prognostic and diagnostic marker, and also serve as a therapeutic factor by reducing CXCR4 in combination with chemotherapeutic drugs.

Cathepsin S Regulates Antigen Processing and T Cell Activity in Non-Hodgkin Lymphoma

Genomic alterations in cancer cells can influence the immune system to favor tumor growth. In non-Hodgkin lymphoma, physiological interactions between B cells and the germinal center microenvironment are coopted to sustain cancer cell proliferation. We found that follicular lymphoma patients harbor a recurrent hotspot mutation targeting tyrosine 132 (Y132D) in cathepsin S (CTSS) that enhances protein activity. CTSS regulates antigen processing and CD4⁺ and CD8⁺ T cell-mediated immune responses. Loss of CTSS activity reduces lymphoma growth by limiting communication with CD4⁺ T follicular helper cells while inducing antigen diversification and activation of CD8⁺ T cells. Overall, our results suggest that CTSS inhibition has non-redundant therapeutic potential to enhance anti-tumor immune responses in indolent and aggressive lymphomas.

Melatonin attenuates epidermal growth factor-induced cathepsin S expression in ARPE-19 cells: Implications for proliferative vitreoretinopathy

Abnormal proliferation and motility of retinal pigment epithelial cells leads to proliferative vitreoretinopathy (PVR). Melatonin is a known effective antitumour and anti-invasive agent, but whether it affects the formation and underlying mechanisms of PVR remains unclear. In this study, the results of the MTT assay, colony formation and propidium iodide (PI) staining with flow cytometry revealed that melatonin dose dependently inhibited epidermal growth factor (EGF)-induced proliferation of human ARPE-19 cells. Furthermore, melatonin reduced EGF-induced motility by suppressing cathepsin S (CTSS) expression. Pretreatment with ZFL (a CTSS inhibitor) or overexpression of CTSS (pCMV-CTSS) significantly inhibited EGF-induced cell motility when combined with melatonin. Epidermal growth factor induced the phosphorylation of AKT(S473)/mTOR (S2448) and transcription factor (c-Jun/Sp1) signaling pathways. Pretreatment of LY294002 (a PI3K inhibitor) or rapamycin (an mTOR inhibitor) markedly reduced EGF-induced motility and p-AKT/p-mTOR/c-Jun/Sp1 expression when combined with melatonin. Taken together, these data indicate that melatonin inhibited EGF-induced proliferation and motility of human ARPE-19 cells by activating the AKT/mTOR pathway, which is dependent on CTSS modulation of c-Jun/Sp1 signalling. Melatonin may be a promising therapeutic drug against PVR.

Cathepsin K inhibition-induced mitochondrial ROS enhances sensitivity of cancer cells to anti-cancer drugs through USP27x-mediated Bim protein stabilization

Cathepsin K (Cat K) is expressed in cancer cells, but the effect of Cat K on apoptosis is still elusive. Here, we showed that inhibition of Cat K sensitized the human carcinoma cells to anti-cancer drug through up-regulation of Bim. Inhibition of Cat K increased USP27x expression, and knock down of USP27x markedly blocked Cat K-induced up-regulation of Bim expression. Furthermore, inhibition of Cat K induced proteasome-dependent degradation of regulatory associated protein of mammalian target of rapamycin (Raptor). Down-regulation of Raptor expression increased mitochondrial ROS production, and mitochondria specific superoxide scavengers prevented USP27x-mediated stabilization of Bim by inhibition of Cat K. Moreover, combined treatment with Cat K inhibitor (odanacatib) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) reduced tumor growth and induced cell death in a xenograft model. Our results demonstrate that Cat K inhibition enhances anti-cancer drug sensitivity through USP27x-mediated the up-regulation of Bim via the down-regulation of Raptor.

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Inhibition of Cat K sensitizes cancer cells to anti-cancer drugs.

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Reduction of Raptor by inhibition of Cat K induces mitochondria dysfunction.

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Mitochondrial ROS induction by inhibition of Cat K induces USP27X expression.

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Up-regulation of USP27X by inhibition of Cat K stabilizes Bim protein.

Inhibition of FOXO3a/BIM signaling pathway contributes to the protective effect of salvianolic acid A against cerebral ischemia/reperfusion injury

Salvianolic acid A (SalA) is an effective compound extracted from traditional Chinese medicine Salvia miltiorrhiza Bunge. The Forkhead box O3a (FOXO3a) signaling pathway plays crucial roles in the modulation of ischemia-induced cell apoptosis. However, no information about the regulatory effect of SalA on FoxO3a is available. To explore the anti-cerebral ischemia effect and clarify the therapeutic mechanism of SalA, SH-SY5Y cells and Sprague–Dawley rats were applied, which were exposed to oxygen glucose deprivation/reoxygenation (OGD/R) and middle cerebral artery occlusion/reperfusion (MCAO/R) injuries, respectively. The involved pathway was identified using the specific inhibitor LY294002. Results showed that SalA concentration-dependently inhibited OGD/R injury triggered cell viability loss. SalA reduced cerebral infarction, lowered brain edema, improved neurological function, and inhibited neuron apoptosis in MCAO/R rats, which were attenuated by the treatment of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) specific inhibitor LY294002. SalA time- and concentration-dependently upregulated the phosphorylation levels of protein kinase B (AKT) and its downstream protein FOXO3a. Moreover, the nuclear translocation of FOXO3a was inhibited by SalA both in vivo and in vitro, which was also reversed by LY294002. The above results indicated that SalA fought against ischemia/reperfusion damage at least partially via the AKT/FOXO3a/BIM pathway.

Cathepsins: Potent regulators in carcinogenesis

Cathepsins (CTS) are mainly lysosomal acid hydrolases extensively involved in the prognosis of different diseases, and having a distinct role in tumor progression by regulating cell proliferation, autophagy, angiogenesis, invasion, and metastasis. As all these processes conjunctively lead to cancer progression, their site-specific regulation might be beneficial for cancer treatment. CTS regulate activation of the proteolytic cascade and protein turnover, while extracellular CTS is involved in promoting extracellular matrix degradation and angiogenesis, thereby stimulating invasion and metastasis. Despite cancer regulation, the involvement of CTS in cellular adaptation toward chemotherapy and radiotherapy augments their therapeutic potential. However, lysosomal permeabilization mediated cytosolic translocation of CTS induces programmed cell death. This complex behavior of CTS generates the need to discuss the different aspects of CTS associated with cancer regulation. In this review, we mainly focused on the significance of each cathepsin in cancer signaling and their targeting which would provide noteworthy information in the context of cancer biology and therapeutics.