Noninvasive Bioluminescence Imaging of Matrix Metalloproteinase-14 Activity in Lung Cancer Using a Membrane-Bound Biosensor

Analysis of Matrix Metalloproteinase Activity and Inhibition in Cancer Spheroids

The utilization of tumor spheroids and organoids has greatly facilitated mechanistic understanding of tumor growth and invasion and lead to more effective high-throughput analysis of potential chemotherapeutic agents. In spheroid and organoid systems, tumor invasion occurs in three dimensions and monitoring this behavior can be data intensive. Quantitative correlation of tumor invasion with protease activity can further exacerbate data storage issues. The present method utilizes the "Hit Pick" approach to provide quantitative analysis and correlation of tumor invasion and membrane type 1 matrix metalloproteinase (MT1-MMP) activity in a rapid fashion with greatly reduced data storage requirements compared with standard image analysis approaches. Inhibition of MT1-MMP activity in spheroids can also be monitored by the present approach.

IL-17 induces non-small cell lung cancer metastasis via GCN5-dependent SOX4 acetylation enhancing MMP9 gene transcription and expression

Interleukin-17 (IL-17), a potent proinflammatory cytokine, can trigger the metastasis of non-small cell lung cancer (NSCLC). However, the underlying mechanism involved in IL-17-induced NSCLC cell metastasis remains unclear. In this study, we found that not only the expression of IL-17, IL-17RA, and/or general control nonrepressed protein 5 (GCN5), SRY-related HMG-BOX gene 4 (SOX4), and matrix metalloproteinase 9 (MMP9) was increased in the NSCLC tissues and in the IL-17-stimulated NSCLC cells, but also IL-17 treatment could enhance NSCLC cell migration and invasion. Further mechanism exploration revealed that IL-17-upregulated GCN5 and SOX4 could bind to the same region (-915 to -712 nt) of downstream MMP9 gene promoter driving its gene transcription. In the process, GCN5 could mediate SOX4 acetylation at lysine 118 (K118, a newly identified site) boosting MMP9 gene expression as well as cell migration and invasion. Moreover, the SOX4 acetylation or MMP9 induction and metastatic nodule number in the lung tissues of the BALB/c nude mice inoculated with the NSCLC cells stably infected by corresponding LV-shGCN5 or LV-shSOX4, LV-shMMP9 plus IL-17 incubation were markedly reduced. Overall, our findings implicate that NSCLC metastasis is closely associated with IL-17-GCN5-SOX4-MMP9 axis.

Signal-On Mass Spectrometric Biosensing of Multiplex Matrix Metalloproteinases with a Phospholipid-Structured Mass-Encoded Microplate

The detection of matrix metalloproteinases (MMPs) is of great importance for diagnosis and staging of cancer. This work proposed a signal-on mass spectrometric biosensing strategy with a phospholipid-structured mass-encoded microplate for assessment of multiplex MMP activities. The designed substrate and internal standard peptides were subsequently labeled with the reagents of isobaric tags for relative and absolute quantification (iTRAQ), and DSPE-PEG(2000)maleimide was embedded on the surface of a 96-well glass bottom plate to fabricate the phospholipid-structured mass-encoded microplate, which offered a simulated environment of the extracellular space for enzyme reactions between MMPs and the substrates. The strategy achieved multiplex MMP activity assays by dropping the sample in the well for enzyme cleavages, followed by adding trypsin to release the coding regions for ultrahigh performance liquid chromatography-tandem mass spectrometric (UHPLC-MS/MS) analysis. The peak area ratios of released coding regions and their respective internal standard (IS) peptides exhibited satisfied linear ranges of 0.05-50, 0.1-250, and 0.1-100 ng mL^-1 with the detection limits of 0.017, 0.046, and 0.032 ng mL^-1 for MMP-2, MMP-7, and MMP-3, respectively. The proposed strategy demonstrated good practicability in inhibition analysis and detections of multiplex MMP activities in serum samples. It is of great potential for clinical applications and can be expanded for multiplex enzyme assays.

Tumor-expressed B7-H3 promotes vasculogenic mimicry formation rather than angiogenesis in non-small cell lung cancer

BACKGROUND

Vasculogenic mimicry (VM), an alternative microvascular circulation independent of angiogenesis, is formed by aggressive cancer cells. Tumor-expressed B7-H3 has been reported to promote VM formation in hepatocellular carcinoma and modulate angiogenesis in breast cancer and colorectal cancer. However, its effects on VM generation and angiogenesis in non-small cell Lung cancer (NSCLC) remained to be elucidated.

METHODS

CRISPR/Cas9-mediated B7-H3 knockout (KO) was conducted in NSCLC A549 and H3255 cells. The expression of VM-related proteins, including vascular endothelial (VE)-cadherin and matrix metalloproteinase 14 (MMP14), and the secretion of vascular endothelial growth factor (VEGF) were measured by western blotting and chemiluminescence assay in both B7-H3 KO and mock-edited A549 and H3255 cells. To examine VM formation, a three-dimensional (3D) culture model was used for B7-H3 KO and mock A549 and H3255 cells. For in vivo analysis, xenograft mice models were established using B7-H3 KO and mock-edited A549 cells, and immunohistochemical (CD31) and histochemical (periodic acid-Schiff, PAS) double staining were performed to identify VM and endothelial vessels in tumor tissues. Finally, specific signaling inhibitors were used to analyze B7-H3-induced signaling pathway responsible for VE-cadherin and MMP14 expression and VM generation.

RESULTS

Higher expression of B7-H3 was associated with a worse prognosis and more advanced T-category in NSCLC. CRISPR/Cas9-mediated B7-H3 KO in A549 and H3255 cells led to decreased expression of VE-cadherin and MMP14; however, the secretion of VEGF by the two cell lines remained unchanged. In the 3D cell culture model, both B7-H3 KO A549 and H3255 cells showed a significant reduction in the formation of capillary-like tubular structures compared to mock-edited cells. In the in vivo xenograft model, mock-edited A549 cells formed excessive PAS⁺ CD31^- VM channels, while B7-H3 KO restrained VM formation in the xenograft tumors. However, no significant differences were found in CD31⁺ endothelial vessels between xenografts formed by B7-H3 KO and mock-edited A549 cells. Finally, we analyzed the signaling pathway responsible for B7-H3-induced VM formation and found that selective inhibition of the phosphoinositide 3-kinase(PI3K)/protein kinase B (AKT) hyperactivation by LY294002 was associated with decreased expression of MMP14 and VE-cadherin, and in vitro VM formation by both A549 and H3255 cells.

CONCLUSIONS

Tumor-expressed B7-H3 acts via PI3K/AKT signaling pathway to promote VM formation by NSCLC cells while bears no effects on angiogenesis in NSCLC.

Screening MT1-MMP Activity and Inhibition in Three-Dimensional Tumor Spheroids

Membrane type 1 matrix metalloproteinase (MT1-MMP) has been shown to be crucial for tumor angiogenesis, invasion, and metastasis, and thus MT1-MMP is a high priority target for potential cancer therapies. To properly evaluate MT1-MMP inhibitors, a screening protocol is desired by which enzyme activity can be quantified in a tumor microenvironment-like model system. In the present study, we applied a fluorogenic, collagen model triple-helical substrate to quantify MT1-MMP activity for tumor spheroids embedded in a collagen hydrogel. The substrate was designed to be MT1-MMP selective and to possess fluorescent properties compatible with cell-based assays. The proteolysis of the substrate correlated to glioma spheroid invasion. In turn, the application of either small molecule or protein-based MMP inhibitors reduced proteolytic activity and glioma spheroid invasion. The presence of MT1-MMP in glioma spheroids was confirmed by western blotting. Thus, spheroid invasion was dependent on MT1-MMP activity, and inhibitors of MT1-MMP and invasion could be conveniently screened in a high-throughput format. The combination of the fluorogenic, triple-helical substrate, the three-dimensional tumor spheroids embedded in collagen, and Hit-Pick software resulted in an easily adaptable in vivo-like tumor microenvironment for rapidly processing inhibitor potential for anti-cancer use.

A highly sensitive NanoLuc-based protease biosensor for detecting apoptosis and SARS-CoV-2 infection

Proteases play critical roles in various biological processes, including apoptosis and viral infection. Several protease biosensors have been developed; however, obtaining a reliable signal from a very low level of endogenous protease activity remains a challenge. In this study, we developed a highly sensitive protease biosensor, named FlipNanoLuc, based on the Oplophorus gracilirostris NanoLuc luciferase. The flipped β-strand was restored by protease activation and cleavage, resulting in the reconstitution of luciferase and enzymatic activity. By making several modifications, such as introducing NanoBiT technology and CL1-PEST1 degradation tag, the FlipNanoLuc-based protease biosensor system achieved more than 500-fold luminescence increase in the corresponding protease-overexpressing cells. We demonstrated that the FlipNanoLuc-based caspase sensor can be utilized for the detection of staurosporine-induced apoptosis with sixfold increase in luminescence. Furthermore, we also demonstrated that the FlipNanoLuc-based coronavirus 3CL-protease sensor can be used to detect human coronavirus OC43 with tenfold increase in luminescence and severe acute respiratory syndrome-coronavirus-2 infections with 20-fold increase in luminescence by introducing the stem-loop 1 sequence to prevent the virus inducing global translational shutdown.

The study of cancer cell in stromal environment through induced pluripotent stem cell-derived mesenchymal stem cells

BACKGROUND

The development of mesenchymal stem cells (MSCs) has gained reputation from its therapeutic potential in stem cell regeneration, anti-inflammation, tumor suppression, and drug delivery treatment. Previous studies have shown MSCs have both promoting and suppressing effects against cancer cells. While the limitation of obtaining a large quantity of homologous MSCs for studies and treatment remains a challenge, an alternative approach involving the production of MSCs derived from induced pluripotent stem cells (iPSCs; induced MSCs [iMSCs]) may be a promising prospect given its ability to undergo prolonged passage and with similar therapeutic profiles as that of their MSC counterparts. However, the influence of iMSC in the interaction of cancer cells remains to be explored as such studies are not well established. In this study, we aim to differentiate iPSCs into MSC-like cells as a potential substitute for adult MSCs and evaluate its effect on non-small-cell lung cancer (NSCLC).

METHODS

iMSCs were derived from iPSCs and validated with reference to the International Society of Cellular Therapy guidelines on MSC criteria. To create a stromal environment, the conditioned medium (CM) of iMSCs was harvested and applied for coculturing of NSCLC of H1975 at different concentrations. The H1975 was then harvested for RNA extraction and subjected to next-generation sequencing (NGS) for analysis.

RESULTS

The morphology of iMSCs-CM-treated H1975 was different from an untreated H1975. Our NGS data suggest the occurrence of apoptotic events and the presence of cytokines from H1975's RNA that are treated with iMSCs-CM.

CONCLUSION

Our results have shown that iMSCs may suppress the growth of H1975 by releasing proapoptotic cytokines into coculture media. Using iPSC-derived MSC models allows a deeper study of tumor cross talk between MSC and cancer cells that can be applied for potential future cancer therapy.

Matrix Metalloproteinases: From Molecular Mechanisms to Physiology, Pathophysiology, and Pharmacology

The first matrix metalloproteinase (MMP) was discovered in 1962 from the tail of a tadpole by its ability to degrade collagen. As their name suggests, matrix metalloproteinases are proteases capable of remodeling the extracellular matrix. More recently, MMPs have been demonstrated to play numerous additional biologic roles in cell signaling, immune regulation, and transcriptional control, all of which are unrelated to the degradation of the extracellular matrix. In this review, we will present milestones and major discoveries of MMP research, including various clinical trials for the use of MMP inhibitors. We will discuss the reasons behind the failures of most MMP inhibitors for the treatment of cancer and inflammatory diseases. There are still misconceptions about the pathophysiological roles of MMPs and the best strategies to inhibit their detrimental functions. This review aims to discuss MMPs in preclinical models and human pathologies. We will discuss new biochemical tools to track their proteolytic activity in vivo and ex vivo, in addition to future pharmacological alternatives to inhibit their detrimental functions in diseases. SIGNIFICANCE STATEMENT: Matrix metalloproteinases (MMPs) have been implicated in most inflammatory, autoimmune, cancers, and pathogen-mediated diseases. Initially overlooked, MMP contributions can be both beneficial and detrimental in disease progression and resolution. Thousands of MMP substrates have been suggested, and a few hundred have been validated. After more than 60 years of MMP research, there remain intriguing enigmas to solve regarding their biological functions in diseases.

In situ ratiometric SERS imaging of intracellular protease activity for subtype discrimination of human breast cancer

Accurate discrimination between different cells at the molecular level is of fundamental importance for disease diagnosis. Endogenous proteases are such molecular candidates for cancer cell subtype study. But in situ probing their activity in live cells remains challenging for surface-enhanced Raman scattering (SERS). Here, we present a sensitive ratio-type SERS nanoprobe for imaging of matrix metalloproteinase-2 (MMP-2) in different cancer cells subtypes. The nanoprobe contained three components: a plasmon-active gold nanoparticle as the SERS enhancing matrix, Raman dye rhodamine B (Rh B)-labelled substrate peptides as the specific MMP-2 recognizer, and 2-naphthalenethiol (2-NT) as the internal standard. MMP-2-responsive cleavage of peptides from the nanoprobe surface results in decrease or even disappearance of SERS emission of Rh B, which was ratioed over the emission of 2-NT for the quantification of MMP-2 activity. Both in-tube assay and in-cell imaging results show that the MMP-responsive nanoprobe can work and serve to differentiate the normal breast cells from the tumorous ones, to differentiate two breast cancer cell subtypes with a different degree of malignancy. We believe that this SERS nanoprobe could find a wide application in the fields of tumor biology and accurate disease diagnosis.

A method establishment and comparison of in vivo lung cancer model development platforms for evaluation of tumour metabolism and pharmaceutical efficacy

BACKGROUND

Currently, the identification of accurate biomarkers for the diagnosis of patients with early-stage lung cancer remains difficult. Fortunately, metabolomics technology can be used to improve the detection of plasma metabolic biomarkers for lung cancer. In a previous study, we successfully utilised machine learning methods to identify significant metabolic markers for early-stage lung cancer diagnosis. However, a related research platform for the investigation of tumour metabolism and drug efficacy is still lacking.

HYPOTHESIS/PURPOSE

A novel methodology for the comprehensive evaluation of the internal tumour-metabolic profile and drug evaluation needs to be established.

METHODS

The optimal location for tumour cell inoculation was identified in mouse chest for the non-traumatic orthotopic lung cancer mouse model. Microcomputed tomography (micro-CT) was applied to monitor lung tumour growth. Proscillaridin A (P.A) and cisplatin (CDDP) were utilised to verify the anti-lung cancer efficacy of the platform. The top five clinically valid biomarkers, including proline, L-kynurenine, spermidine, taurine and palmitoyl-L-carnitine, were selected as the evaluation indices to obtain a suitable lung cancer mouse model for clinical metabolomics research by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

RESULTS

The platform was successfully established, achieving 100% tumour development rate and 0% surgery mortality. P.A and CDDP had significant anti-lung cancer efficacy in the platform. Compared with the control group, four biomarkers in the orthotopic model and two biomarkers in the metastatic model had significantly higher abundance. Principal component analysis (PCA) showed a significant separation between the orthotopic/metastatic model and the control/subcutaneous/KRAS transgenic model. The platform was mainly involved in arginine and proline metabolism, tryptophan metabolism, and taurine and hypotaurine metabolism.

CONCLUSION

This study is the first to simulate clinical metabolomics by comparing the metabolic phenotype of plasma in different lung cancer mouse models. We found that the orthotopic model was the most suitable for tumour metabolism. Furthermore, the anti-tumour drug efficacy was verified in the platform. The platform can very well match the clinical reality, providing better lung cancer diagnosis and securing more precise evidence for drug evaluation in the future.