Cathepsin B: A sellsword of cancer progression

Transcriptome analysis of the immunomodulatory effects of Salvia miltiorrhiza polysaccharide on hemocyte immune response in Procambarus clarkii

Natural plant polysaccharide as immune modulator is considered an effective strategy for healthy aquaculture to reduce medicine treatment. Salvia miltiorrhiza polysaccharides (SMP) had applications to regulate immune activity and enhance antioxidant in vertebrates, but the potential function has been rarely reported in crustaceans. In this study, the immunological effects of SMP on hemocytes of Procambarus clarkii were analyzed. Results showed that total superoxide dismutase (T-SOD), phenoloxidase (PO) activity and respiratory burst were up-regulated after SMP treatment. After high-throughput sequencing, 2170 differentially expressed genes (DEGs) including 1294 up-regulated and 876 down-regulated genes were identified. KEGG function enrichment analysis indicated that DEGs are involved in crustaceans cellular immune-related signaling pathways, including lysosome, phagosome and endocytosis. Transcriptome mining and qRT-PCR showed that SMP up-regulated humoral immunity factors gene expression. Diets supplemented with 0.8% SMP significantly up-regulated the total number of hemocytes (THC), T-SOD and PO activity, improved the survival of crayfish after Citrobacter freundii infection. This study suggested that SMP could improve the cellular and humoral immunity of P. clarkii. Furthermore, this finding supplied a molecular foundation for further comprehending the immunopotentiator effects of plant polysaccharides in crustaceans.

Osteoblasts and osteoclasts: an important switch of tumour cell dormancy during bone metastasis

Bone metastasis occurs when tumour cells dissociate from primary tumours, enter the circulation (circulating tumour cells, CTCs), and colonize sites in bone (disseminated tumour cells, DTCs). The bone marrow seems to be a particularly dormancy-inducing environment for DTCs, yet the mechanisms of dormancy initiation, reactivation, and interaction within the bone marrow have to be elucidated. Intriguingly, some evidence has suggested that dormancy is a reversible state that is switched 'on' or 'off' depending on the presence of various bone marrow resident cells, particularly osteoclasts and osteoblasts. It has become clear that these two cells contribute to regulating dormant tumour cells in bone both directly (interaction) and indirectly (secreted factors). The involved mechanisms include TGFβ signalling, the Wnt signalling axis, the Notch2 pathway, etc. There is no detailed review that specifically focuses on ascertaining the dynamic interactions between tumour cell dormancy and bone remodelling. In addition, we highlighted the roles of inflammatory cytokines during this 'cell-to-cell' communication. We also discussed the potential clinical relevance of remodelling the bone marrow niche in controlling dormant tumour cells. Understanding the unique role of osteoclasts and osteoblasts in regulating tumour dormancy in bone marrow will provide new insight into preventing and treating tumour bone metastasis.

A Novel Antibody-Drug Conjugate Targeting Nectin-2 Suppresses Ovarian Cancer Progression in Mouse Xenograft Models

Ovarian cancer is the fifth leading cause of cancer, followed by front line is mostly platinum agents and PARP inhibitors, and very limited option in later lines. Therefore, there is a need for alternative therapeutic options. Nectin-2, which is overexpressed in ovarian cancer, is a known immune checkpoint that deregulates immune cell function. In this study, we generated a novel anti-nectin-2 antibody (chimeric 12G1, c12G1), and further characterized it using epitope mapping, enzyme-linked immunosorbent assay, surface plasmon resonance, fluorescence-activated cell sorting, and internalization assays. The c12G1 antibody specifically bound to the C2 domain of human nectin-2 with high affinity (K_D = 2.90 × 10^-10 M), but not to mouse nectin-2. We then generated an antibody-drug conjugate comprising the c12G1 antibody conjugated to DM1 and investigated its cytotoxic effects against cancer cells in vitro and in vivo. c12G1-DM1 induced cell cycle arrest at the mitotic phase in nectin-2-positive ovarian cancer cells, but not in nectin-2-negative cancer cells. c12G1-DM1 induced ~100-fold cytotoxicity in ovarian cancer cells, with an IC₅₀ in the range of 0.1 nM~7.4 nM, compared to normal IgG-DM1. In addition, c12G1-DM1 showed ~91% tumor growth inhibition in mouse xenograft models transplanted with OV-90 cells. These results suggest that c12G1-DM1 could be used as a potential therapeutic agent against nectin-2-positive ovarian cancers.

Leucine zipper protein 2 serves as a prognostic biomarker for prostate cancer correlating with immune infiltration and epigenetic regulation

Background

We sought to determine whether leucine zipper protein 2 (LUZP2) could benefit men with prostate cancer (PCa) undergoing radical radiotherapy (RT) or prostatectomy (RP).

Methods

Analysis was done on differentiating expression, clinical prognosis, co-expressed genes, immune infiltration, and epigenetic changes. All of our analyses were done using the R software (version 3.6.3) and the appropriate packages.

Results

In terms of PCa, tumor samples expressed LUZP2 more than normal samples did. In the TCGA database and GSE116918, we found that LUZP2 was the only independent risk factor for PCa. The shared enriched pathways for patients undergoing RP or RT were cell-cell adhesion, regulation of filopodium assembly, and extracellular matrix containing collagen. With the exception of TNFRSF14, we discovered that LUZP2 was negatively correlated with 21 immune checkpoints in PCa patients receiving RT. We found a significant inverse relationship between LUZP2 expression and the tumor immune environment, which included B cells, CD4+ T cells, neutrophils, macrophages, dendritic cells, stromal score, immune score, and estimate score, in patients receiving RP or RT. Additionally, tumor purity was positively correlated with LUZP2. We found that the drug bortezomib may be susceptible to the LUZP2. DNA methylation was significantly associated with the mRNA expression of LUZP2 in PCa patients from the TCGA database, and LUZP2 methylation was positively correlated with immune cells. The proliferative activity of various PCa cells, which correlated to different stages of this disease, was also found to be significantly reduced by LUZP2 reduction, according to the results of our experimental work.

Conclusions

We proposed a relatively comprehensive understanding of the roles of LUZP2 on PCa from the fresh perspective of senescence.

All Roads Lead to Cathepsins: The Role of Cathepsins in Non-Alcoholic Steatohepatitis-Induced Hepatocellular Carcinoma

Cathepsins are lysosomal proteases that are essential to maintain cellular physiological homeostasis and are involved in multiple processes, such as immune and energy regulation. Predominantly, cathepsins reside in the lysosomal compartment; however, they can also be secreted by cells and enter the extracellular space. Extracellular cathepsins have been linked to several pathologies, including non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). NASH is an increasingly important risk factor for the development of HCC, which is the third leading cause of cancer-related deaths and poses a great medical and economic burden. While information regarding the involvement of cathepsins in NASH-induced HCC (NASH-HCC) is limited, data to support the role of cathepsins in either NASH or HCC is accumulating. Since cathepsins play a role in both NASH and HCC, it is likely that the role of cathepsins is more significant in NASH-HCC compared to HCC derived from other etiologies. In the current review, we provide an overview on the available data regarding cathepsins in NASH and HCC, argue that cathepsins play a key role in the transition from NASH to HCC, and shed light on therapeutic options in this context.

Cathepsin L promotes chemresistance to neuroblastoma by modulating serglycin

Cathepsin L (CTSL), a lysosomal acid cysteine protease, is found to play a critical role in chemosencitivity and tumor progression. However, the potential roles and molecular mechanisms of CTSL in chemoresistance in neuroblastoma (NB) are still unclear. In this study, the correlation between clinical characteristics, survival and CTSL expression were assessed in Versteeg dataset. The chemoresistant to cisplatin or doxorubicin was detected using CCK-8 assay. Western blot was employed to detect the expression of CTSL, multi-drug resistance proteins, autophagy-related proteins and apoptosis-related proteins in NB cells while knocking down CTSL. Lysosome staining was analyzed to access the expression levels of lysosomes in NB cells. The expression of apoptosis markers was analyzed with immunofluorescence. Various datasets were analyzed to find the potential protein related to CTSL. In addition, a subcutaneous tumor xenografts model in M-NSG mice was used to assess tumor response to CTSL inhibition in vivo. Based on the validation dataset (Versteeg), we confirmed that CTSL served as a prognostic marker for poor clinical outcome in NB patients. We further found that the expression level of CTSL was higher in SK-N-BE (2) cells than in IMR-32 cells. Knocking down CTSL reversed the chemoresistance in SK-N-BE (2) cells. Furthermore, combination of CTSL inhibition and chemotherapy potently blocked tumor growth in vivo. Mechanistically, CTSL promoted chemoresistance in NB cells by up-regulating multi-drug resistance protein ABCB1 and ABCG2, inhibiting the autophagy level and cell apoptpsis. Furthermore, we observed six datasets and found that Serglycin (SRGN) expression was positively associated with CTSL expresssion. CTSL could mediate chemoresistance by up-regulating SRGN expression in NB cells and SRGN expression was positively correlated with poor prognosis of NB patients. Taken together, our findings indicate that the CTSL promotes chemoresistance to cisplatin and doxorubicin by up-regulating the expression of multi-drug resistance proteins and inhibiting the autophagy level and cell apoptosis in NB cells. Thus, CTSL may be a therapeutic target for overcoming chemoresistant to cisplatin and doxorubicin in NB patients.

NO news: S-(de)nitrosylation of cathepsins and their relationship with cancer

Tumor formation and progression have been much of a study over the last two centuries. Recent studies have seen different developments for the early diagnosis and treatment of the disease; some of which even promise survival of the patient. Cysteine proteases, mainly cathepsins have been unequivocally identified as putative worthy players of redox imbalance that contribute to the premonition and further progression of cancer by interfering in the normal extracellular and intracellular proteolysis and initiating a proteolytic cascade. The present review article focuses on the study of cancer so far, while establishing facts on how future studies focused on the cellular interrelation between nitric oxide (NO) and cancer, can direct their focus on cathepsins. For a tumor cell to thrive and synergize a cancerous environment, different mutations in the proteolytic and signaling pathways and the proto-oncogenes, oncogenes, and the tumor suppressor genes are made possible through cellular biochemistry and some cancer-stimulating environmental factors. The accumulated findings show that S-nitrosylation of cathepsins under the influence of NO-donors can prevent the invasion of cancer and cause cancer cell death by blocking the activity of cathepsins as well as the major denitrosylase systems using a multi-way approach. Faced with a conundrum of how to fill the gap between the dodging of established cancer hallmarks with cathepsin activity and gaining appropriate research/clinical accreditation using our hypothesis, the scope of this review also explores the interplay and crosstalk between S-nitrosylation and S-(de)nitrosylation of this protease and highlights the utility of charging thioredoxin (Trx) reductase inhibitors, low-molecular-weight dithiols, and Trx mimetics using efficient drug delivery system to prevent the denitrosylation or regaining of cathepsin activity in vivo. In foresight, this raises the prospect that drugs or novel compounds that target cathepsins taking all these factors into consideration could be deployed as alternative or even better treatments for cancer, though further research is needed to ascertain the safety, efficiency and effectiveness of this approach.

Correlation of Matrisome-Associatted Gene Expressions with LOX Family Members in Astrocytomas Stratified by IDH Mutation Status

Tumor cell infiltrative ability into surrounding brain tissue is a characteristic of diffusely infiltrative astrocytoma and is strongly associated with extracellular matrix (ECM) stiffness. Collagens are the most abundant ECM scaffolding proteins and contribute to matrix organization and stiffness. LOX family members, copper-dependent amine oxidases, participate in the collagen and elastin crosslinking that determine ECM tensile strength. Common IDH mutations in lower-grade gliomas (LGG) impact prognosis and have been associated with ECM stiffness. We analyzed the expression levels of LOX family members and matrisome-associated genes in astrocytoma stratified by malignancy grade and IDH mutation status. A progressive increase in expression of all five LOX family members according to malignancy grade was found. LOX, LOXL1, and LOXL3 expression correlated with matrisome gene expressions. LOXL1 correlations were detected in LGG with IDH mutation (IDH^mut), LOXL3 correlations in LGG with IDH wild type (IDH^wt) and strong LOX correlations in glioblastoma (GBM) were found. These increasing correlations may explain the increment of ECM stiffness and tumor aggressiveness from LGG-IDH^mut and LGG-IDH^wt through to GBM. The expression of the mechanosensitive transcription factor, β-catenin, also increased with malignancy grade and was correlated with LOXL1 and LOXL3 expression, suggesting involvement of this factor in the outside–in signaling pathway.

High cathepsin A protein expression predicts poor prognosis and tumor recurrence of hepatocellular carcinoma patients after curative hepatectomy

Cathepsin A (CTSA) is overexpressed in various types of cancer and is linked to poor clinical outcomes. However, the clinical application of CTSA in HCC has not been explored. In this study, we examined the protein level of CTSA in the archived HCC samples from 161 patients by Immunohistochemistry (IHC). The high protein level of CTSA was significantly correlated to the poor clinicopathological parameters, such as TNM stage, serum AFP level, tumor differentiation, liver cirrhosis, Child-Pugh class, vascular invasion, tumor encapsulation, tumor recurrence, and patient death. In addition, multivariate Cox regression analysis indicated that high CTSA expression was an independent prognostic factor of OS and RFS. We also analyzed the area under the curve (AUC) of the time-dependent receiver operating characteristic (ROC) of CTSA expression for 1-, 3-, and 5-year OS and RFS prediction. Furthermore, we constructed a nomogram that exhibited excellent prediction performance, which was validated by the calibration curve and decision curve analysis. Together, our study demonstrated that CTSA protein level is strongly associated with poor clinical outcome of HCC patients and may be used as a potential diagnostic and prognostic biomarker in HCC.

Bibliometric Analysis of Cathepsin B Research From 2011 to 2021

Cathepsin B (CTSB) is a lysosomal protease implicated in the progression of various diseases. A large number of CTSB-related studies have been conducted to date. However, there is no comprehensive bibliometric analysis on this subject. In our study, we performed quantitative analysis of CTSB-related publications retrieved from the Science Citation Index Expanded (SCIE) of the Web of Science Core Collection (reference period: 2011–2021). A total of 3,062 original articles and reviews were retrieved. The largest number of publications were from USA (n = 847, 27.66%). The research output of each country showed positive correlation with gross domestic product (GDP) (r = 0.9745, P < 0.0001). Active collaborations between countries/regions were also observed. Reinheckel T and Sloane BF were perhaps the most impactful researchers in the research landscape of CTSB. Plos ONE was the most prevalent (119/3,062, 3.89%) and cited journal (3,021 citations). Comprehensive analysis of the top citations, co-citations, and keywords was performed to acquire the theoretical basis and hotspots of CTSB-related research. The main topics included CTSB-related cancers and inflammatory diseases, CTSB-associated cell death pattern, and the applications of CTSB. These results provide comprehensive insights into the current status of global CTSB-related research especially in pancreas, which is worthy of continued follow-up by practitioners and clinicians in this field.

A risk variant for Barrett's esophagus and esophageal adenocarcinoma at chr8p23.1 affects enhancer activity and implicates multiple gene targets

Nineteen genetic susceptibility loci for esophageal adenocarcinoma (EAC) and its precursor Barrett's esophagus (BE) have been identified through genome-wide association studies (GWAS). Clinical translation of such discoveries, however, has been hindered by the slow pace of discovery of functional/causal variants and gene targets at these loci. We previously developed a systematic informatics pipeline to prioritize candidate functional variants using functional potential scores, applied the pipeline to select high-scoring BE/EAC risk loci, and validated a functional variant at chr19p13.11 (rs10423674). Here, we selected two additional prioritized loci for experimental interrogation: chr3p13/rs1522552 and chr8p23.1/rs55896564. Candidate enhancer regions encompassing these variants were evaluated using luciferase reporter assays in two EAC cell lines. One of the two regions tested exhibited allele-specific enhancer activity - 8p23.1/rs55896564. CRISPR-mediated deletion of the putative enhancer in EAC cell lines correlated with reduced expression of three candidate gene targets: B lymphocyte kinase (BLK), nei like DNA glycosylase 2 (NEIL2), and cathepsin B (CTSB). Expression quantitative trait locus (eQTL) mapping in normal esophagus and stomach revealed strong associations between the BE/EAC risk allele at rs55896564 (G) and lower expression of CTSB, a protease gene implicated in epithelial wound repair. These results further support the utility of functional potential scores for GWAS variant prioritization, and provide the first experimental evidence of a functional variant and risk enhancer at the 8p23.1 GWAS locus. Identification of CTSB, BLK, and NEIL2 as candidate gene targets suggests that altered expression of these genes may underlie the genetic risk association at 8p23.1 with BE/EAC.

Oxidative Stress in Cancer Immunotherapy: Molecular Mechanisms and Potential Applications

Immunotherapy is an effective treatment option that revolutionizes the management of various cancers. Nevertheless, only a subset of patients receiving immunotherapy exhibit durable responses. Recently, numerous studies have shown that oxidative stress induced by reactive oxygen species (ROS) plays essential regulatory roles in the tumor immune response, thus regulating immunotherapeutic effects. Specifically, studies have revealed key roles of ROS in promoting the release of tumor-associated antigens, manipulating antigen presentation and recognition, regulating immune cell phenotypic differentiation, increasing immune cell tumor infiltration, preventing immune escape and diminishing immune suppression. In the present study, we briefly summarize the main classes of cancer immunotherapeutic strategies and discuss the interplay between oxidative stress and anticancer immunity, with an emphasis on the molecular mechanisms underlying the oxidative stress-regulated treatment response to cancer immunotherapy. Moreover, we highlight the therapeutic opportunities of manipulating oxidative stress to improve the antitumor immune response, which may improve the clinical outcome.

In Silico, In Vitro, and Clinical Investigations of Cathepsin B and Stefin A mRNA Expression and a Correlation Analysis in Kidney Cancer

The cysteine protease Cathepsin B (CtsB) plays a critical role in multiple signaling pathways, intracellular protein degradation, and processing. Endogenous inhibitors regulate its enzymatic activity, including stefins and other cystatins. Recent data proved that CtsB is implicated in tumor extracellular matrix remodeling, cell invasion, and metastasis: a misbalance between cathepsins and their natural inhibitors is often considered a sign of disease progression. In the present study, we investigated CtsB and stefin A (StfA) expression in renal cell carcinoma (RCC). mRNA analysis unveiled a significant CTSB and STFA increase in RCC tissues compared to adjacent non-cancerogenic tissues and a higher CtsB expression in malignant tumors than in benign renal neoplasms. Further analysis highlighted a positive correlation between CtsB and StfA expression as a function of patient sex, age, tumor size, grade, lymph node invasion, metastasis occurrence, and survival. Alternative overexpression and silencing of CtsB and StfA confirmed the correlation expression between these proteins in human RCC-derived cells through protein analysis and fluorescent microscopy. Finally, the ectopic expression of CtsB and StfA increased RCC cell proliferation. Our data strongly indicated that CtsB and StfA expression play an important role in RCC development by mutually stimulating their expression in RCC progression.

A seven-autophagy-related gene signature for predicting the prognosis of differentiated thyroid carcinoma

Background

Numerous studies have implicated autophagy in the pathogenesis of thyroid carcinoma. This investigation aimed to establish an autophagy-related gene model and nomogram that can help predict the overall survival (OS) of patients with differentiated thyroid carcinoma (DTHCA).

Methods

Clinical characteristics and RNA-seq expression data from TCGA (The Cancer Genome Atlas) were used in the study. We also downloaded autophagy-related genes (ARGs) from the Gene Set Enrichment Analysis website and the Human Autophagy Database. First, we assigned patients into training and testing groups. R software was applied to identify differentially expressed ARGs for further construction of a protein-protein interaction (PPI) network for gene functional analyses. A risk score-based prognostic risk model was subsequently developed using univariate Cox regression and LASSO-penalized Cox regression analyses. The model’s performance was verified using Kaplan-Meier (KM) survival analysis and ROC curve. Finally, a nomogram was constructed for clinical application in evaluating the patients with DTHCA. Finally, a 7-gene prognostic risk model was developed based on gene set enrichment analysis.

Results

Overall, we identified 54 differentially expressed ARGs in patients with DTHCA. A new gene risk model based on 7-ARGs (CDKN2A, FGF7, CTSB, HAP1, DAPK2, DNAJB1, and ITPR1) was developed in the training group and validated in the testing group. The predictive accuracy of the model was reflected by the area under the ROC curve (AUC) values. Univariate and multivariate Cox regression analysis indicated that the model could independently predict the prognosis of patients with THCA. The constrained nomogram derived from the risk score and age also showed high prediction accuracy.

Conclusions

Here, we developed a 7-ARG prognostic risk model and nomogram for differentiated thyroid carcinoma patients that can guide clinical decisions and individualized therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02590-6.

Single-Cell Transcriptome Analysis Reveals Inter-Tumor Heterogeneity in Bilateral Papillary Thyroid Carcinoma

Background

The tumor microenvironment (TME) plays a pivotal role in cancer progression in papillary thyroid carcinoma (PTC), yet the composition and the phenotype of cells within the TME in bilateral PTC are poorly understood.

Methods

We performed unbiased transcriptome-wide single-cell RNA sequencing (scRNA-seq) analysis on 29,561 cells from 3 pairs of bilateral PTC and 1 non-tumor thyroid sample. The results of the analysis were validated by a large-scale bulk transcriptomic dataset deposited in The Cancer Genome Atlas (TCGA) database.

Results

Our integrative analysis of thyroid follicular cells revealed 42 signaling pathways enriched in malignant follicular cells, including cytokine–cytokine receptor interaction, PI3K/Akt signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, and tumor necrosis factor (TNF) signaling pathway. A 6-gene signature (CXCL3, CXCL1, IL1A, CCL5, TNFRSF12A, and IL18) in the cytokine–cytokine receptor interaction pathway was constructed to predict the prognosis of patients with PTC, with high risk scores being associated with decreased overall survival [hazard ratio (HR) = 3.863, 95% CI = 2.233−6.682, p < 0.001]. Gene set variation analysis (GSVA) indicated that the pathways enriched in bilateral PTC were significantly different, indicating great heterogeneity in bilateral PTC, even with the same BRAF V600E mutation. Comprehensive analysis of T cells revealed that the proportion of CD8⁺ tissue-resident memory T cells expressing IFNG decreased in tumor samples with advanced N stage. Within the myeloid compartment, the ratio of suppressive M2-like to pro-inflammatory M1-like macrophages increased with advanced disease stage, which was confirmed in the bulk dataset using transcriptomic profiles. In addition, we also identified numerous biologically critical interactions among myeloid cells, T cells, and follicular cells, which were related to T-cell recruitment, M2-like macrophage polarization, malignant follicular cell progression, and T-cell inhibitory signaling.

Conclusion

Our integrative analyses revealed great inter-tumor heterogeneity within the TME in bilateral PTC, which will offer assistance for precise diagnosis and treatment.

CTSB is a negative prognostic biomarker and therapeutic target associated with immune cells infiltration and immunosuppression in gliomas

Previous researches have demonstrated the meaning of CTSB for the progress of several tumors, whereas few clues about its immunological characteristic in gliomas. Here we systematically explored its biologic features and clinical significance for gliomas. 699 glioma cases of TCGA and 325 glioma cases of CGGA were respectively included as training and validating cohorts. R software was used for data analysis and mapping. We found that CTSB was remarkably highly-expressed for HGG, IDH wild type, 1p19q non-codeletion type, MGMT promoter unmethylation type and mesenchymal gliomas. CTSB could specifically and sensitively indicate mesenchymal glioma. Upregulated CTSB was an independent hazard correlated with poor survival. CTSB-related biological processes in gliomas chiefly concentrated on immunoreaction and inflammation response. Then we proved that CTSB positively related to most inflammatory metagenes except IgG, including HCK, LCK, MHC II, STAT1 and IFN. More importantly, the levels of glioma-infiltrating immune cells were positively associated with the expression of CTSB, especially for TAMs, MDSCs and Tregs. In conclusion, CTSB is closely related to the malignant pathological subtypes, worse prognosis, immune cells infiltration and immunosuppression of gliomas, which make it a promising biomarker and potential target in the diagnosis, treatment and prognostic assessment of gliomas.

Chemical Design of Activatable Photoacoustic Probes for Precise Biomedical Applications

Photoacoustic (PA) imaging technology, a three-dimensional hybrid imaging modality that integrates the advantage of optical and acoustic imaging, has great application prospects in molecular imaging due to its high imaging depth and resolution. To endow PA imaging with the ability for real-time molecular visualization and precise biomedical diagnosis, numerous activatable molecular PA probes which can specifically alter their PA intensities upon reacting with the targets or biological events of interest have been developed. This review highlights the recent developments of activatable PA probes for precise biomedical applications including molecular detection of the biotargets and imaging of the biological events. First, the generation mechanism of PA signals will be given, followed by a brief introduction to contrast agents used for PA probe design. Then we will particularly summarize the general design principles for the alteration of PA signals and activatable strategies for developing precise PA probes. Furthermore, we will give a detailed discussion of activatable PA probes in molecular detection and biomedical imaging applications in living systems. At last, the current challenges and outlooks of future PA probes will be discussed. We hope that this review will stimulate new ideas to explore the potentials of activatable PA probes for precise biomedical applications in the future.

Cathepsin F and Fibulin-1 as novel diagnostic biomarkers for brain metastasis of non-small cell lung cancer

Background

The lack of non-invasive methods for detection of early micro-metastasis is a major cause of the poor prognosis of non-small cell lung cancer (NSCLC) brain metastasis (BM) patients. Herein, we aimed to identify circulating biomarkers based on proteomics for the early diagnosis and monitoring of patients with NSCLC BM.

Methods

Upregulated proteins were detected by secretory proteomics in the animal-derived high brain metastatic lung cancer cell line. A well-designed study composed of three independent cohorts was then performed to verify these blood-based protein biomarkers: the serum discovery and verification cohorts (n = 80; n = 459), and the tissue verification cohort (n = 76). Logistic regression was used to develop a diagnostic biomarker panel. Model validation cohort (n = 160) was used to verify the stability of the constructed predictive model. Changes in serum Cathepsin F (CTSF) levels of patients were tracked to monitor the treatment response. Progression-free survival (PFS) and overall survival (OS) were analysed to assess their prognostic relevance.

Results

CTSF and Fibulin-1 (FBLN1) levels were specifically upregulated in sera and tissues of patients with NSCLC BM compared with NSCLC without BM and primary brain tumour. The combined diagnostic performance of CTSF and FBLN1 was superior to their individual ones. CTSF serum changes were found to reflect the therapeutic response of patients with NSCLC BM and the trends of progression were detected earlier than the magnetic resonance imaging changes. Elevated expression of CTSF in NSCLC BM tissues was associated with poor PFS, and was found to be an independent prognostic factor.

Conclusions

We report a novel blood-based biomarker panel for early diagnosis, monitoring of therapeutic response, and prognostic evaluation of patients with NSCLC BM.

ASPER-29 suppresses the metastasis of pancreatic cancer cells by dual inhibition of cathepsin-L and cathepsin-S

Pancreatic cancer will be the second leading cause of cancer-related mortality worldwide due to its high rate of metastasis. Cathepsins (CATs) are effectors of invasive growth in various cancers. Currently, targeting CATs represents an attractive strategy for the treatment of highly metastatic cancers with high CATs activity, such as pancreatic cancer. To develop a stronger antimetastatic agent, ASPER-29, a novel inhibitor of CATs designed by using the asperphenamate derivative BBP as a lead compound, was synthesized, and its therapeutic potential in pancreatic cancer metastasis was investigated in this study. Molecular docking and enzyme inhibition assays proved that ASPER-29 can inhibit the activity of CAT-L and CAT-S by binding with these enzymes in classical action modes. Furthermore, ASPER-29 significantly inhibited the activity of CAT-L and CAT-S but had no effect on their expression in PANC-1 and BxPC-3 cells. The in vitro antimetastatic activities of ASPER-29 were examined by wound healing and Transwell chamber assays. We found that ASPER-29 inhibited the migration and invasion of PANC-1 and BxPC-3 cells in a concentration-dependent manner. Moreover, the in vivo antimetastatic effects of ASPER-29 were confirmed in a mouse xenotransplantation model. H&E staining and immunohistochemistry assays of Ki67 and CEACAM6 proved that ASPER-29 treatment significantly blocked the metastasis of pancreatic cancer cells to lung and liver tissues. Additionally, the activity of both CAT-L and CAT-S was markedly inhibited in the lung and liver tissues of ASPER-29-administered mice compared with the mice in the model group, suggesting that the metastasis-blocking effect of ASPER-29 should be mediated via inhibition of the activity of CAT-L and CAT-S in pancreatic cancer cells. Together, our results demonstrated that ASPER-29, as a novel inhibitor of CAT-L and CAT-S, possessed the evident ability to block the metastasis of pancreatic cancer cells.

Cathepsin B is a potential therapeutic target for coronavirus disease 2019 patients with lung adenocarcinoma

Coronavirus disease 2019 (COVID-19) was declared a serious global public health emergency. Hospitalization and mortality rates of lung cancer patients diagnosed with COVID-19 are higher than those of patients presenting with other cancers. However, the reasons for the outcomes being disproportionately severe in lung adenocarcinoma (LUAD) patients with COVID-19 remain elusive. The present study aimed to identify the possible causes for disproportionately severe COVID-19 outcomes in LUAD patients and determine a therapeutic target for COVID-19 patients with LUAD. We used publicly available data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and various bioinformatics tools to identify and analyze the genes implicated in SARS-CoV-2 infection in LUAD patients. Upregulation of the SARS-CoV-2 infection-related molecules dipeptidyl peptidase 4, basigin, cathepsin B (CTSB), methylenetetrahydrofolate dehydrogenase, and peptidylprolyl isomerase B rather than angiotensin-converting enzyme 2 may explain the relatively high susceptibility of LUAD patients to SARS-CoV-2 infection. CTSB was highly expressed in the LUAD tissues after SARS-CoV-2 infection, and its expression was positively correlated with immune cell infiltration and proinflammatory cytokine expression. These findings suggest that CTSB plays a vital role in the hyperinflammatory response in COVID-19 patients with LUAD and is a promising target for the development of a novel drug therapy for COVID-19 patients.

Secretory autophagy-induced bladder tumour-derived extracellular vesicle secretion promotes angiogenesis by activating the TPX2-mediated phosphorylation of the AURKA-PI3K-AKT axis

Tumour angiogenesis is an independent risk factor for bladder cancer (BCa) progression, but viable and promising antiangiogenic targets are understudied. Secretory autophagy has received increasing interest recently, while the roles and executing mechanisms in the tumour microenvironment (TME) remain unclear. Herein, we found that active cathepsin B (CTSB) was upregulated in tumour tissues and serum EVs of 241 BCa patients from four cohorts and was significantly associated with poor prognosis. Starving TME (STME)-induced conventional autophagy in BCa cells elevated active CTSB levels by facilitating the expression and nuclear translocation of NFATC2. In addition, STME-induced secretory autophagy simultaneously led to markedly increased secretion of LC3-conjugated EVs loaded with active CTSB (EV-CTSB) into the TME. The increased exogenous active CTSB in endothelial cells by directly ingesting EV-CTSB prominently activated the TPX2-mediated phosphorylation of the AURKA-PI3K-AKT axis, increased VEGFA expression, and promoted angiogenesis. Our findings not only verify that EV-CTSB can be a promising target for antiangiogenic strategies in bladder cancer, but also reveal a novel action pattern based on secretory autophagy-induced EV secretion which is enlightening to explore crosstalk in the TME from various perspectives.

Size-Adjustable Nano-Drug Delivery Systems for Enhanced Tumor Retention and Penetration

Over the past decades, nano-drug delivery systems have shown great potential in improving tumor treatment. And the controllability and design flexibility of nanoparticles endow them a broad development space. The particle size is one of the most important factors affecting the potency of nano-drug delivery systems. Large-size (100–200 nm) nanoparticles are more conducive to long circulation and tumor retention, but have poor tumor penetration; small-size (<50 nm) nanoparticles can deeply penetrate tumor but are easily cleared. Most of the current fixed-size nanoparticles are difficult to balance the retention and penetration, while the proposal of size-adjustable nano-drug delivery systems offers a solution to this paradox. Many endogenous and exogenous stimuli, such as acidic pH, upregulated enzymes, temperature, light, catalysts, redox conditions, and reactive oxygen species, can trigger the in situ transformation of nanoparticles based on protonation, hydrolysis, click reaction, phase transition, photoisomerization, redox reaction, etc. In this review, we summarize the principles and applications of stimuli-responsive size-adjustable strategies, including size-enlargement strategies and size-shrinkage strategies. We also propose the challenges faced by size-adjustable nano-drug delivery systems, hoping to promote the development of this strategy.

Smart Nanotherapeutics and Lung Cancer

Lung cancer is a significant health problem worldwide. Unfortunately, current therapeutic strategies lack a sufficient level of specificity and can harm adjacent healthy cells. Consequently, to address the clinical need, novel approaches to improve treatment efficiency with minimal side effects are required. Nanotechnology can substantially contribute to the generation of differentiated products and improve patient outcomes. Evidence from previous research suggests that nanotechnology-based drug delivery systems could provide a promising platform for the targeted delivery of traditional chemotherapeutic drugs and novel small molecule therapeutic agents to treat lung cancer cells more effectively. This has also been found to improve the therapeutic index and reduce the required drug dose. Nanodrug delivery systems also provide precise control over drug release, resulting in reduced toxic side effects, controlled biodistribution, and accelerated effects or responses. This review highlights the most advanced and novel nanotechnology-based strategies, including targeted nanodrug delivery systems, stimuli-responsive nanoparticles, and bio-nanocarriers, which have recently been employed in preclinical and clinical investigations to overcome the current challenges in lung cancer treatments.

Experimental and Clinical Evidence Supports the Use of Urokinase Plasminogen Activation System Components as Clinically Relevant Biomarkers in Gastroesophageal Adenocarcinoma

Simple Summary

Patients with gastric and oesophageal adenocarcinomas (GOCs) have short life expectancies as their tumours spread to other sites early. This is facilitated by the increased expression of the urokinase plasminogen activation system (uPAS); a feature of the majority of GOCs. There is increasing appreciation of the importance of uPAS expression in a range of cell types within the tumour microenvironment. Abundant clinical evidence indicates that altered expression of uPAS proteins is associated with worse outcomes, including time to tumour recurrence and patient survival. Emerging technologies, including liquid biopsy, suggest a role of uPAS for the detection of circulating tumour cells, which are responsible for the dissemination of cancers. We review and summarise pre-clinical and clinical data that supports the use of uPAS as a biomarker in GOC.

Abstract

Gastric and oesophageal cancers (GOCs) are lethal cancers which metastasise early and recur frequently, even after definitive surgery. The urokinase plasminogen activator system (uPAS) is strongly implicated in the invasion and metastasis of many aggressive tumours including GOCs. Urokinase plasminogen activator (uPA) interaction with its receptor, urokinase plasminogen activator receptor (uPAR), leads to proteolytic activation of plasminogen to plasmin, a broad-spectrum protease which enables tumour cell invasion and dissemination to distant sites. uPA, uPAR and the plasminogen activator inhibitor type 1 (PAI-1) are overexpressed in some GOCs. Accumulating evidence points to a causal role of activated receptor tyrosine kinase pathways enhancing uPAS expression in GOCs. Expression of these components are associated with poorer clinicopathological features and patient survival. Stromal cells, including tumour-associated macrophages and myofibroblasts, also express the key uPAS proteins, supporting the argument of stromal involvement in GOC progression and adverse effect on patient survival. uPAS proteins can be detected on circulating leucocytes, circulating tumour cells and within the serum; all have the potential to be developed into circulating biomarkers of GOC. Herein, we review the experimental and clinical evidence supporting uPAS expression as clinical biomarker in GOC, with the goal of developing targeted therapeutics against the uPAS.

Understanding the interactions between inorganic-based nanomaterials and biological membranes

The interactions between inorganic-based nanomaterials (NMs) and biological membranes are among the most important phenomena for developing NM-based therapeutics and resolving nanotoxicology. Herein, we introduce the structural and functional effects of inorganic-based NMs on biological membranes, mainly the plasma membrane and the endomembrane system, with an emphasis on the interface, which involves highly complex networks between NMs and biomolecules (such as membrane proteins and lipids). Significant efforts have been devoted to categorizing and analyzing the interaction mechanisms in terms of the physicochemical characteristics and biological effects of NMs, which can directly or indirectly influence the effects of NMs on membranes. Importantly, we summarize that the biological membranes act as platforms and thereby mediate NMs-immune system contacts. In this overview, the existing challenges and potential applications in the areas are addressed. A strong understanding of the discussed concepts will promote therapeutic NM designs for drug delivery systems by leveraging the NMs-membrane interactions and their functions.

Cathepsin B-Activated Fluorescent and Photoacoustic Imaging of Tumor

Early diagnosis is crucial to the treatment of cancer. Cathepsin B (CTB) plays an important role in numerous cancers, which is a promising biomarker for early diagnosis of cancer. It is necessary to exploit new probes for visualization of CTB in vivo. Fluorescent/photoacoustic (FL/PA) imaging is a powerful tool for in vivo study which possesses both excellent sensitivity and spatial resolution. To our knowledge, there has been no FL/PA probe to image CTB in vitro or in vivo. Therefore, we developed two CTB-activated FL/PA probes HCy-Cit-Val and HCy-Gly-Leu-Phe-Gly, which could successfully monitor CTB activity in vivo. Both two probes had excellent sensitivity and selectivity in vitro. Cell imaging showed that HCy-Cit-Val or HCy-Gly-Leu-Phe-Gly could image endogenous CTB in lysosome with 6.8-fold or 5.1-fold enhancement of the FL signal and 5.8-fold or 3.4-fold enhancement of the PA signal compared to their inhibitor contrast groups. Tumor imaging in vivo further confirmed the good applicability of these two probes to monitor CTB activity with high sensitivity and spatial resolution. Moreover, the property of HCy-Cit-Val is superior to HCy-Gly-Leu-Phe-Gly due to the higher catalytic efficiency of CTB toward HCy-Cit-Val than HCy-Gly-Leu-Phe-Gly. We envision that our FL/PA probe HCy-Cit-Val will be suitable for clinical early diagnosis of CTB-related cancer in the near future.

RNA interference mediated suppression of TRPV6 inhibits the progression of prostate cancer in vitro by modulating cathepsin B and MMP9 expression

Purpose

The transient receptor potential vanilloid 6 (TRPV6) channel is overexpressed in prostate cancer and its silencing is known to inhibit the growth of LNCaP cells. However, the role of TRPV6 in the metastasis of prostate cancer cells and its relationship to the invasive markers, matrix metalloproteinase (MMP) and cathepsin B, is unclear. Thus, the present study was focused on understanding these tumor-related processes.

Materials and Methods

We performed a wound-healing assay and a Transwell migration and invasion assay to assess the migration and invasion of prostate cancer cells. Western blot analysis was used to measure the expression of cathepsin B, MMP2, and MMP9.

Results

TRPV6 siRNA significantly inhibited the proliferation of LNCaP prostate cancer cells. It also significantly attenuated the wound healing and migration capacities of LNCaP cells. Moreover, the invasiveness of LNCaP cells and the expression of MMP9 and cathepsin B in LNCaP cells were also significantly inhibited by TRPV6 siRNA.

Conclusions

The results indicate that TRPV6 may promote prostate cancer progression in association with MMP9 and cathepsin B, thereby validating further research into TRPV6 as a useful therapeutic target for local invasion or metastasis of advanced prostate cancer.

Genetic polymorphisms of Cathepsin B are associated with gastric cancer risk and prognosis in a Chinese population

BACKGROUND

Genetic polymorphisms are believed to represent a key aspect of predisposition to gastric cancer (GC). Therefore, considering the important role of Cathepsin B (CTSB) in promoting cancer onset and development, it could be very worthful to explore the function of CTSB-related genetic polymorphisms in GC.

OBJECTIVE

In this study, we investigated the correlation of CTSB-related polymorphisms (rs9009A>T, rs6731T>C, rs1293303G>C, rs1874547C>T, rs3779659C>T, rs17814426C>T and rs148669985C>T) with GC risk and prognosis in a case-control study of 994 cases and 1000 controls.

METHODS

All tag single nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction-ligase detection reaction (PCR-LDR) sequencing technology.

RESULTS

The results indicated rs9009, rs6731 and rs17814426 correlated with decreased risks of GC (HR = 0.97, p< 0.001; HR = 0.86, P= 0.019; HR = 0.85, P= 0.017; respectively). Stratification analysis further showed rs17814426 variant genotypes correlated with earlier T stage (p= 0.044). In addition, GC patients carrying the C allele of rs6371 had better overall prognosis (HR = 0.62, 95%CI = 0.44-0.88).

CONCLUSION

Our results firstly suggested the importance of CTSB-related polymorphisms on GC which could predict GC risk and prognosis.

Significances of viable synergistic autophagy-associated cathepsin B and cathepsin D (CTSB/CTSD) as potential biomarkers for sudden cardiac death

Background

The Cathepsins family, including cathepsin B and cathepsin D, potentially affects the entire processes involved in atherosclerosis. Although coronary heart disease (CHD) has been widely studied as the basis of Sudden Cardiac Death (SCD), the relationship between CHD and CTSB/D remains unclear.

Methods

We screened for differentially expressed proteins (DEPs) associated with autophagy by limma package in R. For the genes corresponding to the DEPs after screening, we used various databases to carry out functional enrichment of related DEGs to explore their possible influence on a specific aspect of the disease. Functional enrichment analysis of DEGs was performed by DAVID, Metascape and GSEA. STRING and Cytoscape were obtained the hub genes, the analysis of interaction networks through the GENMANIA and Networkanalyst. Western Blot was used to validate the protein expression level of target genes. TF and miRNA prediction were performed using Networkanalyst and visualized using Cytoscape.

Results

The expression levels of members of the cathepsin family were up regulated in CHD tissues compared with the control. GO and KEGG revealed that cathepsin was markedly enriched in endopeptidase activities, immune responses, lysosome pathways, et al. The correlation analysis showed that in patients with CHD, the CTSB/CTSD expression were negatively correlated with ATG4D and BNIP3, but positively with BCL2L1, CAPNS1, and TP53. In the TF-mRNA-miRNA network, has-miR-24-3p and has-miR-128-3p had higher degrees, CTSB/CTSD could be targeted by them.

Conclusions

Our findings elucidated the expression and regulatory role of cathepsins in coronary heart disease induced SCD and might further explore the potential mechanisms of autophagy in CHD.

Curcumin analogue AI-44 alleviates MSU-induced gouty arthritis in mice via inhibiting cathepsin B-mediated NLRP3 inflammasome activation

NOD-like receptors (NLRs), as a part of intracellular pattern recognition receptors (PRR), are important regulators in innate immune system. The NLRP3 inflammasome which is a member of NLRs has been linked to several human inflammatory diseases. Gouty arthritis is triggered when the deposition of monosodium urate (MSU) crystals in joints induces acute inflammation characterized by the recruitment of macrophages and neutrophils. In this study, we explored the curcumin analogue AI-44 alleviated the gouty arthritis in mice via suppressing MSU engaging NLRP3 inflammasome activation. Furthermore, we demonstrated that AI-44 inhibited the interaction of cathepsin B and NLRP3 to prevent the activation of NLRP3 inflammasome. Moreover, we found AI-44 inhibited the enzyme activity of cathepsin B and bound to the key residue E122 in cytoplasm but not in lysosome. Collectively, these data suggest that AI-44 is a novel drug candidate for the treatment of gouty arthritis through targeting cathepsin B and inhibiting NLRP3 inflammasome activation.

A bi-directional dialog between vascular cells and monocytes/macrophages regulates tumor progression

Cancer progression largely depends on tumor blood vessels as well on immune cell infiltration. In various tumors, vascular cells, namely endothelial cells (ECs) and pericytes, strongly regulate leukocyte infiltration into tumors and immune cell activation, hence the immune response to cancers. Recently, a lot of compelling studies unraveled the molecular mechanisms by which tumor vascular cells regulate monocyte and tumor-associated macrophage (TAM) recruitment and phenotype, and consequently tumor progression. Reciprocally, TAMs and monocytes strongly modulate tumor blood vessel and tumor lymphatic vessel formation by exerting pro-angiogenic and lymphangiogenic effects, respectively. Finally, the interaction between monocytes/TAMs and vascular cells is also impacting several steps of the spread of cancer cells throughout the body, a process called metastasis. In this review, the impact of the bi-directional dialog between blood vascular cells and monocytes/TAMs in the regulation of tumor progression is discussed. All together, these data led to the design of combinations of anti-angiogenic and immunotherapy targeting TAMs/monocyte whose effects are briefly discussed in the last part of this review.

Proteases and Their Modulators in Cancer Therapy: Challenges and Opportunities

Proteostasis is the process of regulating intracellular proteins to maintain the balance of the cell proteome, which is crucial for cancer cell survival. Several proteases located in the cytoplasm, mitochondria, lysosome, and extracellular environment have been identified as potential antitumor targets because of their involvement in proteostasis. Although the discovery of small-molecule inhibitors targeting proteases faces particular challenges, rapid advances in chemical biology and structural biology, and the new technology of drug discovery have facilitated the development of promising protease modulators. In this review, the protein structure and function of important tumor-related proteases and their inhibitors are presented. We also provide a prospective on advances and the outlook of new drug strategies that target these proteases.

Expression Profile Analysis Identifies a Novel Seven Immune-Related Gene Signature to Improve Prognosis Prediction of Glioblastoma

Glioblastoma multiform (GBM) is a malignant central nervous system cancer with dismal prognosis despite conventional therapies. Scientists have great interest in using immunotherapy for treating GBM because it has shown remarkable potential in many solid tumors, including melanoma, non-small cell lung cancer, and renal cell carcinoma. The gene expression patterns, clinical data of GBM individuals from the Cancer Genome Atlas database (TCGA), and immune-related genes (IRGs) from ImmPort were used to identify differentially expressed IRGs through the Wilcoxon rank-sum test. The association between each IRG and overall survival (OS) of patients was investigated by the univariate Cox regression analysis. LASSO Cox regression assessment was conducted to explore the prognostic potential of the IRGs of GBM and construct a risk score formula. A Kaplan–Meier curve was created to estimate the prognostic role of IRGs. The efficiency of the model was examined according to the area under the receiver operating characteristic (ROC) curve. The TCGA internal dataset and two GEO external datasets were used for model verification. We evaluated IRG expression in GBM and generated a risk model to estimate the prognosis of GBM individuals with seven optimal prognostic expressed IRGs. A landscape of 22 types of tumor-infiltrating immune cells (TIICs) in glioblastoma was identified, and we investigated the link between the seven IRGs and the immune checkpoints. Furthermore, there was a correlation between the IRGs and the infiltration level in GBM. Our data suggested that the seven IRGs identified in this study are not only significant prognostic predictors in GBM patients but can also be utilized to investigate the developmental mechanisms of GBM and in the design of personalized treatments for them.

Genomic and Epigenomic Profile of Uterine Smooth Muscle Tumors of Uncertain Malignant Potential (STUMPs) Revealed Similarities and Differences with Leiomyomas and Leiomyosarcomas

Uterine smooth muscle tumors of uncertain malignant potential (STUMPs) represent a heterogeneous group of tumors that cannot be histologically diagnosed as unequivocally benign or malignant. For this reason, many authors are working to obtain a better definition of diagnostic and prognostic criteria. In this work, we analyzed the genomic and epigenomic profile of uterine smooth muscle tumors (USMTs) in order to find similarities and differences between STUMPs, leiomyosarcomas (LMSs) and leiomyomas (LMs), and possibly identify prognostic factors in this group of tumors. Array-CGH data on 23 USMTs demonstrated the presence of a more similar genomic profile between STUMPs and LMSs. Some genes, such as PRKDC and PUM2, with a potential prognostic value, were never previously associated with STUMP. The methylation data appears to be very promising, especially with regards to the divergent profile found in the sample that relapsed, characterized by an overall CGI hypomethylation. Finally, the Gene Ontology analysis highlighted some cancer genes that could play a pivotal role in the unexpected aggressive behavior that can be found in some of these tumors. These genes could prove to be prognostic markers in the future.

A hemocyte-specific cathepsin L-like cysteine protease is involved in response to 20-hydroxyecdysone and microbial pathogens stimulation in silkworm, Bombyx mori

Cathepsin L protease belongs to the papain-like cysteine proteases family, plays indispensable roles in animals' pathological and physiological processes. However, little is known about Cathepsin L in silkworm, Bombyx mori. Herein, a novel Cathepsin L-like (Cat L-like) was cloned and identified from silkworm by the rapid amplification of cDNA ends (RACE). Cat L-like contains an intact open reading frame (ORF) of 1 668 bp and encodes 556 amino acid residues, consisting of a signal peptide, typical cathepsins' inhibitor_I29, and pept_C1 domain. Cat L-like is specifically and highly expressed in hemocytes. The cathepsin (including Cathepsin L, B, and H) crude extract from hemocytes had typical substrate specific catalytic activities and were sensitive to pH and temperature. Cat L-like up-regulated considerably after 20-hydroxyecdysone (20-E) administration, indicating that Cat L-like may be regulated by insect hormone. The responses of Cat L-like against bacterial infection suggest it may play essential roles in silkworm immunity. Overall, our studies provide a theoretical basis and insights to further investigate the functions of Cat L-like and in insects' innate immunity mechanisms.

Cepharanthine as a Potential Novel Tumor-Regional Therapy in Treating Cutaneous Melanoma: Altering the Expression of Cathepsin B, Tumor Suppressor Genes and Autophagy-Related Proteins

The incidence of primary cutaneous melanoma continues to increase annually and is one of the most aggressive malignancies in humans and need to develop more novel non-surgical therapies. Autophagy and cathepsin B targeted therapy was reported to improve melanoma treatment. Cepharanthine (CEP), a natural alkaloid extracted from the genus Cephalophyllum has been reported to have the function of inhibiting cancers. We found that CEP inhibited human primary cutaneous melanoma cells viability and proliferation in 24 h in vitro, and topical application or intra-tumoral injection of CEP decreased the growth of cutaneous melanoma in mice within 4 weeks. CEP preparations below 50% concentration did not induce skin irritation and allergy reaction on human skin in vivo. Primary cutaneous melanoma cells incubated with CEP, the expression of cathepsin B was decreased and the LC3-I and LC3-II expression changed in a dose-dependent manner, while p53, p21Cip1p, and p16Inka gene expression was up-regulated. We demonstrated the effects of CEP as a novel tumor-regional therapy for cutaneous melanoma and provided a preliminary research basis for future clinical treatment researches and the exploration of integrated treatments with systemic therapy, radiotherapy, and surgery for human primary cutaneous melanoma.

Cathepsin B is highly expressed in pancreatic cancer stem-like cells and is associated with patients' surgical outcomes

Cancer stem-like cells (CSLCs) in solid tumors are resistant to conventional chemotherapy and molecularly targeted therapy, which is thought to contribute to cancer recurrence and metastasis. The present study aimed to identify biomarkers for pancreatic CSLCs (P-CSLCs). Using our previously reported methods, P-CSLC-enriched populations were generated from pancreatic cancer cell lines. The protein expression profiles of these populations were compared with those of parental cells using two-dimensional electrophoresis, tandem mass spectrometry, flow cytometry and immunohistochemistry. Protein expression in surgical specimens was also evaluated for relationships with clinical outcomes. A lysosomal cysteine protease, cathepsin B (CTSB), was significantly upregulated in P-CSLCs compared with that in the parental cells, as shown using western blotting. Flow cytometry analysis also confirmed that CTSB was more highly expressed on the surface of P-CSLCs compared with that on parental cells. Moreover, PCLCs had elevated cellular secretions of CTSB compared with the parental cells. Finally, CTSB expression was evaluated in 69 resected tumor specimens, and high expression was associated with the patients' clinicopathological features and surgical outcomes. The present results suggested that CTSB is a biomarker for poor survival in patients with pancreatic cancer, which is possibly associated with P-CSLCs. This novel biomarker may also have potential as a therapeutic target.

Internalization of HMGB1 (High Mobility Group Box 1) Promotes Angiogenesis in Endothelial Cells

OBJECTIVE

In patients with peripheral artery disease, blockages in arterioles <1 mm cannot be treated surgically, and there are currently few effective medicines. Studies have shown that inflammation in ischemic tissue is related to injury recovery and angiogenesis, but insufficient attention has been paid to this area. Studies have suggested that HMGB1 (high mobility group protein 1), which is released by ischemic tissue, promotes angiogenesis, but the mechanism is not entirely clear. In this study, we tested the internalization of HMGB1 in endothelial cells and investigated a novel proangiogenic pathway. Approach and Results: Using green fluorescent protein-tagged HMGB1 to stimulate endothelial cells, we demonstrated HMGB1 internalization via dynamin and RAGE (receptor for advanced glycation end products)-dependent signaling. Using a fluorescence assay, we detected internalized protein fusion to lysosomes, followed by activation of CatB (cathepsin B) and CatL (cathepsin L). The latter promoted the release of VEGF (vascular endothelial growth factor)-A and endoglin and upregulated the capacities of cell migration, proliferation, and tube formation in endothelial cells. We identified that the cytokine-induced fragment-a key functional domain in HMGB1-mediates the internalization and angiogenic function of HMGB1. We further confirmed that HMGB1 internalization also occurs in vivo in endothelial cells and promotes angiogenesis in mouse femoral artery ligation.

CONCLUSIONS

In this study, we identified a novel pathway of HMGB1 internalization-induced angiogenesis in endothelial cells. This finding sheds light on the regulatory role of inflammatory factors in angiogenesis through cell internalization and opens a new door to understand the relationship between inflammation and angiogenesis in ischemic diseases.

Proteomic and Transcriptomic Profiling Identifies Early Developmentally Regulated Proteins in Dictyostelium Discoideum

Cyclic AMP acts as a secondary messenger involving different cellular functions in eukaryotes. Here, proteomic and transcriptomic profiling has been combined to identify novel early developmentally regulated proteins in eukaryote cells. These proteomic and transcriptomic experiments were performed in Dictyostelium discoideum given the unique advantages that this organism offers as a eukaryotic model for cell motility and as a nonmammalian model of human disease. By comparing whole-cell proteome analysis of developed (cAMP-pulsed) wild-type AX2 cells and an independent transcriptomic analysis of developed wild-type AX4 cells, our results show that up to 70% of the identified proteins overlap in the two independent studies. Among them, we have found 26 proteins previously related to cAMP signaling and identified 110 novel proteins involved in calcium signaling, adhesion, actin cytoskeleton, the ubiquitin-proteasome pathway, metabolism, and proteins that previously lacked any annotation. Our study validates previous findings, mostly for the canonical cAMP-pathway, and also generates further insight into the complexity of the transcriptomic changes during early development. This article also compares proteomic data between parental and cells lacking glkA, a GSK-3 kinase implicated in substrate adhesion and chemotaxis in Dictyostelium. This analysis reveals a set of proteins that show differences in expression in the two strains as well as overlapping protein level changes independent of GlkA.