MMP-13 In-Vivo Molecular Imaging Reveals Early Expression in Lung Adenocarcinoma

The multifaceted roles of matrix metalloproteinases in lung cancer

Background

Though the matrix metalloproteinases (MMPs) are widely investigated in lung cancer (LC), however, almost no review systematically clarify their multi-faced roles in LC.

Methods

We investigated the expression of MMPs and their effects on survival of patients with LC, the resistance mechanisms of MMPs in anti-tumor therapy, the regulatory networks of MMPs involved, the function of MMPs inducing CSCLs, MMPs-related tumor immunity, and effects of MMP polymorphisms on risk of LC.

Results

High expression of MMPs was mainly related to poor survival, high clinical stages and cancer metastasis. Role of MMPs in LC are multi-faced. MMPs are involved in drug resistance, induced CSCLs, participated in tumor immunity. Besides, MMPs polymorphisms may increase risk of LC.

Conclusions

MMPs might be promising targets to restore the anti-tumor immune response and enhance the killing function of nature immune cells in LC.

Pre-Clinical Study: Immunohistochemical evaluation of matrix metalloproteinase-13 on rabbit (Oryctolagus cuniculus) socket healing after application of platelet-rich fibrin with and without hydroxyapatite

Background: Tissue engineering technology has been used globally and proven to accelerate wound healing. This study aimed to analyse the effect of adding hydroxyapatite (HA) as a scaffold to platelet-rich fibrin (PRF) as a growth factor in accelerating the wound healing process as seen from the expression of matrix metalloproteinase-13 (MMP-13). Methods: This research is an animal experiment conducted on 18 rabbits (Oryctolagus cuniculus). Rabbits were randomly divided into the following three groups of treatment: (G1) the application of PRF group, (G2) the application of PRF+HA group and (C) the control group without any application. Furthermore, each treatment group was split randomly into three groups of observation time. Periodontal tissue biopsy was performed to analyse the histopathological features that were examined on the basis of the level of MMP-13 immunoexpression. Results: MMP-13 immunoexpression in the PRF+HA group showed better histoscore results, indicating a substantial reduction in MMP-13 values compared with other groups. The healing process was shown to increase with increasing observation time (p<0.05), and the PRF+HA group outperformed the PRF and control groups. On day 3, MMP-13 exhibited a dark brown colour of Immunohistochemistry (IHC), which indicated an increase in the expression value of MMP-13 in the early stages of healing, namely, inflammation. On day 14, light brown IHC was seen, especially in group 2, as a reference that the remodeling process had begun. Conclusions: This study indicates that the administration of PRF and HA was capable of reducing the MMP-13 expression that significantly accelerates the socket healing process. Hydroxyapatite is an alloplastic material that has inherent bioactive properties that support osteoconduction, can bind MMPs, and showed faster healing results based on the observation time as documented by immunohistochemistry.

USMB-shMincle: a virus-free gene therapy for blocking M1/M2 polarization of tumor-associated macrophages

Mincle is essential for tumor-associated macrophage (TAM)-driven cancer progression and represents a potential immunotherapeutic target for cancer. Nevertheless, the lack of a specific inhibitor has largely limited its clinical translation. Here, we successfully developed a gene therapeutic strategy for silencing Mincle in a virus-free and tumor-specific manner by combining RNA interference technology with an ultrasound-microbubble-mediated gene transfer system (USMB). We identified a small hairpin RNA (shRNA) sequence shMincle that can silence not only Mincle expression but also the protumoral effector production in mouse bone marrow- and human THP-1-derived macrophages in the cancer setting in vitro. By using our well-established USMB system (USMB-shMincle), the shMincle-expressing plasmids were delivered in a tissue-specific manner into xenografts of human lung carcinoma A549 and melanoma A375 in vivo. Encouragingly, we found that USMB-shMincle effectively inhibited the protumoral phenotypes of TAMs as well as the progression of both A549 and A375 xenografts in a dose-dependent manner in mice without significant side effects. Mechanistically, we identified that USMB-shMincle markedly enhanced the anticancer M1 phenotype of TAMs in the A549 and A375 xenografts by blocking the protumoral Mincle/Syk/nuclear factor κB (NF-κB) signaling axis. Thus, USMB-shMincle may represent a clinically translatable novel and safe gene therapeutic approach for cancer treatment.

Optical Detection of Distal Lung Enzyme Activity in Human Inflammatory Lung Disease

Objective and Impact Statement. There is a need to develop platforms delineating inflammatory biology of the distal human lung. We describe a platform technology approach to detect in situ enzyme activity and observe drug inhibition in the distal human lung using a combination of matrix metalloproteinase (MMP) optical reporters, fibered confocal fluorescence microscopy (FCFM), and a bespoke delivery device. Introduction. The development of new therapeutic agents is hindered by the lack of in vivo in situ experimental methodologies that can rapidly evaluate the biological activity or drug-target engagement in patients. Methods. We optimised a novel highly quenched optical molecular reporter of enzyme activity (FIB One) and developed a translational pathway for in-human assessment. Results. We demonstrate the specificity for matrix metalloproteases (MMPs) 2, 9, and 13 and probe dequenching within physiological levels of MMPs and feasibility of imaging within whole lung models in preclinical settings. Subsequently, in a first-in-human exploratory experimental medicine study of patients with fibroproliferative lung disease, we demonstrate, through FCFM, the MMP activity in the alveolar space measured through FIB One fluorescence increase (with pharmacological inhibition). Conclusion. This translational in situ approach enables a new methodology to demonstrate active drug target effects of the distal lung and consequently may inform therapeutic drug development pathways.

Crosstalk between MMP-13, CD44, and TWIST1 and its role in regulation of EMT in patients with esophageal squamous cell carcinoma

Matrix metalloproteinases (MMPs) play key roles in epithelial-mesenchymal transition (EMT) for the development of cancer cell invasion and metastasis. MMP-13 is an extracellular matrix (ECM)-degrading enzyme that plays crucial roles in angiogenesis, cell cycle regulation, niche maintenance, and transforming squamous epithelial cells in various tissues. CD44, a transmembrane glycoprotein expressed on esophageal tumor cells, is required for EMT induction and invasion in esophageal squamous cell carcinoma (ESCC). The transcription factor TWIST1, as EMT and stemness marker, regulates MMPs expression and is identified as the downstream target of CD44. In this study, we aimed to investigate the probable interplay between the expression of key genes contributing to ESCC development, including MMP-13, TWIST1, and CD44 with clinical features for introducing novel diagnostic and therapeutic targets in the disease. The gene expression profiling of MMP-13, TWIST1, and CD44 was performed using quantitative real-time PCR in tumor tissues from 50 ESCC patients compared to corresponding margin non-tumoral tissues. Significant overexpression of MMP-13, CD44S, CD44V3, CD44V6, and TWIST1 were observed in 74%, 36%, 44%, 44%, and 52% of ESCC tumor samples, respectively. Overexpression of MMP-13 was associated with stage of tumor progression, metastasis, and tumor location (P < 0.05). There was a significant correlation between TWIST1 overexpression and grade (P < 0.05). Furthermore, overexpression of CD44 variants was associated with stage of tumor progression, grade, tumor invasion, and location (P < 0.05). The results indicated the significant correlation between concomitant expression of MMP-13/TWIST1, TWIST1/CD44, and CD44/MMP-13 with each other in a variety of clinicopathological traits, including depth of tumor invasion, tumor location, stage of tumor, and lymph node involvement in ESCC tissue samples (P < 0.05). Collectively, our results indicate that the TWIST1-CD44-MMP-13 axis is involved in tumor aggressiveness, proposing these genes as regulators of EMT, diagnostic markers, and therapeutic targets in ESCC.

Astragalus Polysaccharide (PG2) Suppresses Macrophage Migration Inhibitory Factor and Aggressiveness of Lung Adenocarcinoma Cells

Astragalus membranaceus is the most popular traditional Chinese medicine for managing vital energy deficiency. Its injectable polysaccharide PG2 has been used for relieving cancer-related fatigue, and PG2 has immune-modulatory and anti-inflammatory effects. In this study, we explored the effects of PG2 in lung adenocarcinoma A549 and CL1-2 cells and investigated its anticancer activity, and the results were validated in severe combined immunodeficiency (SCID) mice. Although PG2 did not inhibit the growth of these cells, it dose-dependently suppressed their migration and invasion, accompanied by reduced vimentin and AXL and induced epithelial cadherin (E-cadherin) expression. Regarding the underlying molecular mechanism, PG2 treatment reduced the macrophage migration inhibitory factor (MIF), an inflammatory cytokine that promotes the epithelial-mesenchymal transition and aggressiveness of cancer cells. Consistent with the previous finding that MIF regulates matrix metalloproteinase-13 (MMP-13) and AMP-activated protein kinase (AMPK), treatment with PG2 reduced MMP-13 and activated AMPK in A549 and CL1-2 cells in this study. In SCID mice injected with A549 cells through the tail vein, intraperitoneal injection with PG2 reduced lung and abdominal metastases in parallel with decreased immunohistochemical staining of AXL, vimentin, MMP-13, and MIF in the tumor. Collectively, data revealed a potential application of PG2 in integrative cancer treatment through the suppression of MIF in cancer cells and their aggressiveness.

A matrix metalloproteinase activation probe for painting human tumours

A probe that allows specific 'painting' of human tumours is described. Probe activation was mediated by specific matrix metalloproteinases, resulting not only in disruption of a FRET pair, but in the generation of a fragment that "fluorescently paints" human tumours. This probe demonstrated rapid and effective human tumour labelling with the potential to allow margin detection during surgical resection.

Ab locks for improving the selectivity and safety of antibody drugs

Monoclonal antibodies (mAbs) are a major targeted therapy for malignancies, infectious diseases, autoimmune diseases, transplant rejection and chronic inflammatory diseases due to their antigen specificity and longer half-life than conventional drugs. However, long-term systemic antigen neutralization by mAbs may cause severe adverse events. Improving the selectivity of mAbs to distinguish target antigens at the disease site from normal healthy tissue and reducing severe adverse events caused by the mechanisms-of-action of mAbs is still a pressing need. Development of pro-antibodies (pro-Abs) by installing a protease-cleavable Ab lock is a novel and advanced recombinant Ab-based strategy that efficiently masks the antigen binding ability of mAbs in the normal state and selectively "turns on" the mAb activity when the pro-Ab reaches the proteolytic protease-overexpressed diseased tissue. In this review, we discuss the design and advantages/disadvantages of different Ab lock strategies, focusing particularly on spatial-hindrance-based and affinity peptide-based approaches. We expect that the development of different masking strategies for mAbs will benefit the local reactivity of mAbs at the disease site, increase the therapeutic efficacy and safety of long-term treatment with mAbs in chronic diseases and even permit scientists to develop Ab drugs for formerly undruggable targets and satisfy the unmet medical needs of mAb therapy.

pH-dependent and cathepsin B activable CaCO3 nanoprobe for targeted in vivo tumor imaging

Background: The intraoperative visualization of tumor cells is a powerful modality for surgical treatment of solid tumors. Since the completeness of tumor excision is closely correlated with the survival of patients, probes that can assist in distinguishing tumor cells are highly demanded.

Purpose: In the present study, a fluorescent probe JF1 was synthesized for imaging of tumor cells by conjugating a substrate of cathepsin B (quenching moiety) to Oregon Green derivative JF2 using a self-immolative linker.

Methods: JF1 was then loaded into the folate-PEG modified CaCO₃ nanoparticles. The folate receptor-targeted, pH-dependent, and cathepsin B activable CaCO₃ nanoprobe was test in vitro and in vivo for tumor imaging.

Results: CaCO₃ nanoprobe demonstrated good stability and fast lighting ability in tumors under low pH conditions. It also showed lower fluorescence background than the single cathepsin B dependent fluorescent probe. The pH-dependent and cathepsin B controlled “turn-on” property enables precise and fast indication of tumor in vitro and in vivo.

Conclusion: This strategy of controlled drug delivery enables in vivo imaging of tumor nodules with a high signal-to-noise ratio, which has great potential in surgical tumor treatment.

Bimodal fluorogenic sensing of matrix proteolytic signatures in lung cancer

Optical biosensing based on the activation of fluorescent reporters offers a powerful methodology for the real-time molecular interrogation of pathology. Here we report a first-in-class, bimodal fluorescent reporter strategy for the simultaneous and highly specific detection of two independent proteases (thrombin and matrix metalloproteases (MMPs)) pivotal in the fibroproliferative process surrounding lung cancer, based on a dual, multiplexing, peptide FRET system. This sophisticated synthetic smartprobe, with a molecular weight of 6 kDa, contains two independent fluorophores and quenchers that generate photonic signatures at two specific wavelengths upon activation by target enzymes within human lung cancer tissue.

Molecular imaging of pulmonary diseases

Imaging holds an important role in the diagnosis of lung diseases. Along with clinical tests, noninvasive imaging techniques provide complementary and valuable information that enables a complete differential diagnosis. Various novel molecular imaging tools are currently under investigation aimed toward achieving a better understanding of lung disease physiopathology as well as early detection and accurate diagnosis leading to targeted treatment. Recent research on molecular imaging methods that may permit differentiation of the cellular and molecular components of pulmonary disease and monitoring of immune activation are detailed in this review. The application of molecular imaging to lung disease is currently in its early stage, especially compared to other organs or tissues, but future studies will undoubtedly reveal useful pulmonary imaging probes and imaging modalities.

Estrogen metabolism in the human lung: impact of tumorigenesis, smoke, sex and race/ethnicity

Previous data from this group demonstrate that the murine lung metabolizes estrogen. Production of the putative carcinogen 4-hydroxyestrogen (4-OHE) is elevated within the lungs of female vs. male mice and accelerated by tobacco smoke. The goal of this study was to determine if the human lung metabolizes estrogen and evaluate the impact of tumor formation, smoke, sex and race/ethnicity on metabolism. Urine and lung tissue (normal, tumor) were obtained from 49 non-small cell lung cancer patients. Healthy postmenopausal Caucasian (n = 19) and Chinese (n = 20) American women (never-smokers) donated urine. Quantitative RT-PCR analyses indicate that multiple estrogen synthesis and metabolism genes are expressed in human bronchoalveolar cells. Estrogen and its metabolites were measured in lung tissue and urine using liquid chromatography/tandem mass spectrometry. Wilcoxon rank tests were used for statistical comparisons. E₁, E₂, E₃ and estrogen metabolites 2-OHE₁, 2-OHE₂, 4-OHE₁, 4-OHE₂, 2-OME₁ and 2-OME₂ were detected at higher levels in tumor vs. adjacent normal tissue and in women vs. men (P < 0.05). The proportion of 4-OHEs was higher in tumors than in normal lung tissue (P < 0.05), and elevated in normal tissue from current- vs. never-smoking women (P = 0.006); similar trends were observed in urine. The proportion of 4-OHEs in the urine of postmenopausal Chinese American women was 1.8-fold higher than that of Caucasian women (P = 0.015). These data indicate that estrogen metabolites are present in the human lung. A shift towards 4-hydroxylation during lung tumorigenesis may contribute to the risk conferred by smoking, sex or race/ethnicity.

Sensitive in vivo Visualization of Breast Cancer Using Ratiometric Protease-activatable Fluorescent Imaging Agent, AVB-620

With the goal of improving intraoperative cancer visualization, we have developed AVB-620, a novel intravenously administered, in vivo fluorescent peptide dye conjugate that highlights malignant tissue and is optimized for human use. Matrix metalloproteinases (MMPs) hydrolyze AVB-620 triggering tissue retention and a ratiometric fluorescence color change which is visualized using camera systems capable of imaging fluorescence and white light simultaneously. AVB-620 imaging visualizes primary tumors and demonstrated high in vivo diagnostic sensitivity and specificity (both >95%) for identifying breast cancer metastases to lymph nodes in two immunocompetent syngeneic mouse models. It is well tolerated and single-dose toxicology studies in rats determined a no-observed-adverse-effect-level (NOAEL) at >110-fold above the imaging and estimated human dose. Protease specificity and hydrolysis kinetics were characterized and compared using recombinant MMPs. To understand the human translation potential, an in vitro diagnostic study was conducted to evaluate the ability of AVB-620 to differentiate human breast cancer tumor from healthy adjacent tissue. Patient tumor tissue and healthy adjacent breast tissue were homogenized, incubated with AVB-620, and fluorogenic responses were compared. Tumor tissue had 2-3 fold faster hydrolysis than matched healthy breast tissue; generating an assay sensitivity of 96% and specificity of 88%. AVB-620 has excellent sensitivity and specificity for identifying breast cancer in mouse and human tissue. Significant changes were made in the design of AVB-620 relative to previous ratiometric protease-activated agents. AVB-620 has pharmaceutical properties, fluorescence ratio dynamic range, usable diagnostic time window, a scalable synthesis, and a safety profile that have enabled it to advance into clinical evaluation in breast cancer patients.

Characterization of the Tumor Microenvironment and Tumor-Stroma Interaction by Non-invasive Preclinical Imaging

Tumors are often characterized by hypoxia, vascular abnormalities, low extracellular pH, increased interstitial fluid pressure, altered choline-phospholipid metabolism, and aerobic glycolysis (Warburg effect). The impact of these tumor characteristics has been investigated extensively in the context of tumor development, progression, and treatment response, resulting in a number of non-invasive imaging biomarkers. More recent evidence suggests that cancer cells undergo metabolic reprograming, beyond aerobic glycolysis, in the course of tumor development and progression. The resulting altered metabolic content in tumors has the ability to affect cell signaling and block cellular differentiation. Additional emerging evidence reveals that the interaction between tumor and stroma cells can alter tumor metabolism (leading to metabolic reprograming) as well as tumor growth and vascular features. This review will summarize previous and current preclinical, non-invasive, multimodal imaging efforts to characterize the tumor microenvironment, including its stromal components and understand tumor–stroma interaction in cancer development, progression, and treatment response.

Matrix Metalloproteases as Biomarkers of Disease

Matrix metalloprotease play a vital role in many cellular processes. Dysfunction in activity of these enzymes has been implicated in the pathogenesis of a number of diseases. Factors that affect the balanced interaction between MMPs and their inhibitors, such as genetic mutations of extracellular matrix components or dysregulation of MMP expression, can lead to various diseases. Due to their essential role in ECM remodeling, MMPs have become targets of interest as biomarkers for the diagnosis and prognosis of diseases associated with alterations of the ECM.

Microenvironmental changes in the progression from adenocarcinoma in situ to minimally invasive adenocarcinoma and invasive lepidic predominant adenocarcinoma of the lung

OBJECTIVES

Invasive lepidic predominant adenocarcinoma (LPA) of the lung is thought to progress in a stepwise fashion from adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA). The aim of this study was to investigate the microenvironmental changes during the development from AIS to LPA.

MATERIALS AND METHODS

Clinicopathological characteristics of AIS (n=51), MIA (n=59), LPA smaller than 3cm (LPA-S, n=113), and LPA larger than 3cm (LPA-L, n=47) were analyzed. We then evaluated the expression levels of epithelial-mesenchymal transition (EMT)-related molecules (E-cadherin, S100A4), invasion-related molecules (laminin-5, ezrin), stem-cell-related molecules (ALDH-1), and growth factor receptors (c-Met, EGFR) in cancer cells of each group (n=20). The number of tumor-promoting stromal cells, including podoplanin-positive cancer-associated fibroblasts (PDPN+ CAFs), CD204-positive tumor-associated macrophages (CD204+ TAMs), and CD34+ microvessel cells, were also analyzed.

RESULTS

No significant difference in these characteristics was found between LPA-S and LPA-L. Laminin-5 expression in the non-invasive carcinoma component of MIA was significantly higher than that of AIS (p<0.001). During the progression from MIA to LPA-S, the expression level of laminin-5 in the invasive carcinoma component was significantly elevated (p<0.01). Moreover, tumor-promoting stromal cells were more frequently recruited in the invasive area of LPA-S (PDPN+ CAFs; p<0.05, CD204+ TAMs; p<0.001, CD34+ microvessel; p<0.05). Ezrin expression in the invasive carcinoma component of LPA-L was significantly increased (p<0.05) compared to LPA-S; however, the number of tumor-promoting stromal cells were not different between these two groups.

CONCLUSION

Our current results indicated that microenvironmental molecular changes occur during the progression from MIA to LPA-S and suggested that this process may play an important role in disease progression from AIS to LPA.