Type VII collagen regulates expression of OATP1B3, promotes front-to-rear polarity and increases structural organisation in 3D spheroid cultures of RDEB tumour keratinocytes

Near-infrared photodynamic and photothermal co-therapy based on organic small molecular dyes

Near-infrared (NIR) organic small molecule dyes (OSMDs) are effective photothermal agents for photothermal therapy (PTT) due to their advantages of low cost and toxicity, good biodegradation, and strong NIR absorption over a wide wavelength range. Nevertheless, OSMDs have limited applicability in PTT due to their low photothermal conversion efficiency and inadequate destruction of tumor regions that are nonirradiated by NIR light. However, they can also act as photosensitizers (PSs) to produce reactive oxygen species (ROS), which can be further eradicated by using ROS-related therapies to address the above limitations of PTT. In this review, the synergistic mechanism, composition, and properties of photodynamic therapy (PDT)-PTT nanoplatforms were comprehensively discussed. In addition, some specific strategies for further improving the combined PTT and PDT based on OSMDs for cancer to completely eradicate cancer cells were outlined. These strategies include performing image-guided co-therapy, enhancing tumor infiltration, increasing H2O2 or O2 in the tumor microenvironment, and loading anticancer drugs onto nanoplatforms to enable combined therapy with phototherapy and chemotherapy. Meanwhile, the intriguing prospects and challenges of this treatment modality were also summarized with a focus on the future trends of its clinical application.

Characterization of Human Colon Organoids From Inflammatory Bowel Disease Patients

Inflammatory Bowel Diseases (IBD) are chronic inflammatory disorders, where epithelial defects drive, at least in part, some of the pathology. We reconstituted human intestinal epithelial organ, by using three-dimension culture of human colon organoids. Our aim was to characterize morphological and functional phenotypes of control (non-IBD) organoids, compared to inflamed organoids from IBD patients. The results generated describe the epithelial defects associated with IBD in primary organoid cultures, and evaluate the use of this model for pharmacological testing of anti-inflammatory approaches. Human colonic tissues were obtained from either surgical resections or biopsies, all harvested in non-inflammatory zones. Crypts were isolated from controls (non-IBD) and IBD patients and were cultured up to 12-days. Morphological (size, budding formation, polarization, luminal content), cell composition (proliferation, differentiation, immaturity markers expression), and functional (chemokine and tight junction protein expression) parameters were measured by immunohistochemistry, RT-qPCR or western-blot. The effects of inflammatory cocktail or anti-inflammatory treatments were studied in controls and IBD organoid cultures respectively. Organoid cultures from controls or IBD patients had the same cell composition after 10 to 12-days of culture, but IBD organoid cultures showed an inflammatory phenotype with decreased size and budding capacity, increased cell death, luminal debris, and inverted polarization. Tight junction proteins were also significantly decreased in IBD organoid cultures. Inflammatory cytokine cocktail reproduced this inflammatory phenotype in non-IBD organoids. Clinically used treatments (5-ASA, glucocorticoids, anti-TNF) reduced some, but not all parameters. Inflammatory phenotype is associated with IBD epithelium, and can be studied in organoid cultures. This model constitutes a reliable human pre-clinical model to investigate new strategies targeting epithelial repair.

Epidermolysis Bullosa-Associated Squamous Cell Carcinoma: From Pathogenesis to Therapeutic Perspectives

Epidermolysis bullosa (EB) is a heterogeneous group of inherited skin disorders determined by mutations in genes encoding for structural components of the cutaneous basement membrane zone. Disease hallmarks are skin fragility and unremitting blistering. The most disabling EB (sub)types show defective wound healing, fibrosis and inflammation at lesional skin. These features expose patients to serious disease complications, including the development of cutaneous squamous cell carcinomas (SCCs). Almost all subjects affected with the severe recessive dystrophic EB (RDEB) subtype suffer from early and extremely aggressive SCCs (RDEB-SCC), which represent the first cause of death in these patients. The genetic determinants of RDEB-SCC do not exhaustively explain its unique behavior as compared to low-risk, ultraviolet-induced SCCs in the general population. On the other hand, a growing body of evidence points to the key role of tumor microenvironment in initiation, progression and spreading of RDEB-SCC, as well as of other, less-investigated, EB-related SCCs (EB-SCCs). Here, we discuss the recent advances in understanding the complex series of molecular events (i.e., fibrotic, inflammatory, and immune processes) contributing to SCC development in EB patients, cross-compare tumor features in the different EB subtypes and report the most promising therapeutic approaches to counteract or delay EB-SCCs.

The role of collagen in cancer: from bench to bedside

Collagen is the major component of the tumor microenvironment and participates in cancer fibrosis. Collagen biosynthesis can be regulated by cancer cells through mutated genes, transcription factors, signaling pathways and receptors; furthermore, collagen can influence tumor cell behavior through integrins, discoidin domain receptors, tyrosine kinase receptors, and some signaling pathways. Exosomes and microRNAs are closely associated with collagen in cancer. Hypoxia, which is common in collagen-rich conditions, intensifies cancer progression, and other substances in the extracellular matrix, such as fibronectin, hyaluronic acid, laminin, and matrix metalloproteinases, interact with collagen to influence cancer cell activity. Macrophages, lymphocytes, and fibroblasts play a role with collagen in cancer immunity and progression. Microscopic changes in collagen content within cancer cells and matrix cells and in other molecules ultimately contribute to the mutual feedback loop that influences prognosis, recurrence, and resistance in cancer. Nanoparticles, nanoplatforms, and nanoenzymes exhibit the expected gratifying properties. The pathophysiological functions of collagen in diverse cancers illustrate the dual roles of collagen and provide promising therapeutic options that can be readily translated from bench to bedside. The emerging understanding of the structural properties and functions of collagen in cancer will guide the development of new strategies for anticancer therapy.

A Unique Panel of Patient-Derived Cutaneous Squamous Cell Carcinoma Cell Lines Provides a Preclinical Pathway for Therapeutic Testing

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) incidence continues to rise with increasing morbidity and mortality, with limited treatment options for advanced disease. Future improvements in targeted therapy will rely on advances in genomic/transcriptomic understanding and the use of model systems for basic research. We describe here the panel of 16 primary and metastatic cSCC cell lines developed and characterised over the past three decades in our laboratory in order to provide such a resource for future preclinical research and drug screening.

METHODS

Primary keratinocytes were isolated from cSCC tumours and metastases, and cell lines were established. These were characterised using short tandem repeat (STR) profiling and genotyped by whole exome sequencing. Multiple in vitro assays were performed to document their morphology, growth characteristics, migration and invasion characteristics, and in vivo xenograft growth.

RESULTS

STR profiles of the cSCC lines allow the confirmation of their unique identity. Phylogenetic trees derived from exome sequence analysis of the matched primary and metastatic lines provide insight into the genetic basis of disease progression. The results of in vivo and in vitro analyses allow researchers to select suitable cell lines for specific experimentation.

CONCLUSIONS

There are few well-characterised cSCC lines available for widespread preclinical experimentation and drug screening. The described cSCC cell line panel provides a critical tool for in vitro and in vivo experimentation.

Injury- and inflammation-driven skin fibrosis: The paradigm of epidermolysis bullosa

Genetic or acquired destabilization of the dermal extracellular matrix evokes injury- and inflammation-driven progressive soft tissue fibrosis. Dystrophic epidermolysis bullosa (DEB), a heritable human skin fragility disorder, is a paradigmatic disease to investigate these processes. Studies of DEB have generated abundant new information on cellular and molecular mechanisms at play in skin fibrosis which are not only limited to intractable diseases, but also applicable to some of the most common acquired conditions. Here, we discuss recent advances in understanding the biological and mechanical mechanisms driving the dermal fibrosis in DEB. Much of this progress is owed to the implementation of cell and tissue omics studies, which we pay special attention to. Based on the novel findings and increased understanding of the disease mechanisms in DEB, translational aspects and future therapeutic perspectives are emerging.

Epidermal aspects of type VII collagen: Implications for dystrophic epidermolysis bullosa and epidermolysis bullosa acquisita

Type VII collagen (COL7), a major component of anchoring fibrils in the epidermal basement membrane zone, has been characterized as a defective protein in dystrophic epidermolysis bullosa and as an autoantigen in epidermolysis bullosa acquisita. Although COL7 is produced and secreted by both epidermal keratinocytes and dermal fibroblasts, the role of COL7 with regard to the epidermis is rarely discussed. This review focuses on COL7 physiology and pathology as it pertains to epidermal keratinocytes. We summarize the current knowledge of COL7 production and trafficking, its involvement in keratinocyte dynamics, and epidermal carcinogenesis in COL7 deficiency and propose possible solutions to unsolved issues in this field.

Combinatorial Omics Analysis Reveals Perturbed Lysosomal Homeostasis in Collagen VII-deficient Keratinocytes

The extracellular matrix protein collagen VII is part of the microenvironment of stratified epithelia and critical in organismal homeostasis. Mutations in the encoding gene COL7A1 lead to the skin disorder dystrophic epidermolysis bullosa (DEB), are linked to skin fragility and progressive inflammation-driven fibrosis that facilitates aggressive skin cancer. So far, these changes have been linked to mesenchymal alterations, the epithelial consequences of collagen VII loss remaining under-addressed. As epithelial dysfunction is a principal initiator of fibrosis, we performed a comprehensive transcriptome and proteome profiling of primary human keratinocytes from DEB and control subjects to generate global and detailed images of dysregulated epidermal molecular pathways linked to loss of collagen VII. These revealed downregulation of interaction partners of collagen VII on mRNA and protein level, but also increased abundance of S100 pro-inflammatory proteins in primary DEB keratinocytes. Increased TGF-β signaling because of loss of collagen VII was associated with enhanced activity of lysosomal proteases in both keratinocytes and skin of collagen VII-deficient individuals. Thus, loss of a single structural protein, collagen VII, has extra- and intracellular consequences, resulting in inflammatory processes that enable tissue destabilization and promote keratinocyte-driven, progressive fibrosis.

Unique mouse monoclonal antibodies reactive with maturation-related epitopes on type VII collagen

In this study, we generated a new set of monoclonal antibodies (mAbs) to bovine and human type VII collagen (COL7) by immunizing mice with bovine cornea-derived basement membrane zone (BMZ) fraction. The four mAbs, tentatively named as COL7-like mAbs, showed speckled subepidermal staining in addition to linear BMZ staining of normal human skin and bovine cornea, a characteristic immunofluorescence feature of COL7, but showed no reactivity with COL7 by in vitro biochemical analyses. Taking advantage of the phenomenon that COL7-like mAbs did not react with mouse BMZ, we compared immunofluorescence reactivity between wild-type and COL7-rescued humanized mice and found that COL7-like mAbs reacted with BMZ of COL7-rescued humanized mice. In ELISAs, COL7-like mAbs reacted with intact triple-helical mammalian recombinant protein (RP) of COL7 but not with bacterial RP. Furthermore, COL7-like mAbs did not react with COL7 within either cultured DJM-1 cells or basal cells of skin of a bullous dermolysis of the newborn patient. These results confirmed that COL7-like mAbs reacted with human and bovine COL7. The epitopes for COL7-like mAbs were considered to be present only on mature COL7 after secretion from keratinocytes and deposition to BMZ and to be easily destroyed during immunoblotting procedure. Additional studies indicated association of the speckled subepidermal staining with both type IV collagen and elastin. These unique anti-COL7 mAbs should be useful in studies of both normal and diseased conditions, particularly dystrophic epidermolysis bullosa, which produces only immature COL7.

Multifunctional Photosensitizer Grafted on Polyethylene Glycol and Polyethylenimine Dual-Functionalized Nanographene Oxide for Cancer-Targeted Near-Infrared Imaging and Synergistic Phototherapy

The integration of photodynamic therapy (PDT) with photothermal therapy (PTT) offers improved efficacy in cancer phototherapy. Herein, a PDT photosensitizer (IR-808) with cancer-targeting ability and near-infrared (NIR) sensitivity was chemically conjugated to both polyethylene glycol (PEG)- and branched polyethylenimine (BPEI)-functionalized nanographene oxide (NGO). Because the optimal laser wavelength (808 nm) of NGO for PTT is consistent with that of IR-808 for PDT, the IR-808-conjugated NGO sheets (NGO-808, 20-50 nm) generated both large amounts of reactive oxygen species (ROS) and local hyperthermia as a result of 808 nm laser irradiation. With PEG- and BPEI-modified NGO as the carrier, the tumor cellular uptake of NGO-808 exhibited higher efficacy than that of strongly hydrophobic free IR-808. Through evaluation with both human and mouse cancer cells, NGO-808 was demonstrated to provide significantly enhanced PDT and PTT effects compared to individual PDT using IR-808 or PTT using NGO. Furthermore, NGO-808 preferentially accumulated in cancer cells as mediated by organic-anion transporting polypeptides (OATPs) overexpressed in many cancer cells, providing the potential for highly specific cancer phototherapy. Using the targeting ability of NGO-808, in vivo NIR fluorescence imaging enabled tumors and their margins to be clearly visualized at 48 h after intravenous injection, providing a theranostic platform for imaging-guided cancer phototherapy. Remarkably, after a single injection of NGO-808 and 808 nm laser irradiation for 5 min, the tumors in two tumor xenograft models were ablated completely, and no tumor recurrence was observed. After treatment with NGO-808, no obvious toxicity was detected in comparison to control groups. Thus, high-performance cancer phototherapy with minimal side effects was afforded from synergistic PDT/PTT treatment and cancer-targeted accumulation of NGO-808.

Lysyl Hydroxylase 3 Localizes to Epidermal Basement Membrane and Is Reduced in Patients with Recessive Dystrophic Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is caused by mutations in COL7A1 resulting in reduced or absent type VII collagen, aberrant anchoring fibril formation and subsequent dermal-epidermal fragility. Here, we identify a significant decrease in PLOD3 expression and its encoded protein, the collagen modifying enzyme lysyl hydroxylase 3 (LH3), in RDEB. We show abundant LH3 localising to the basement membrane in normal skin which is severely depleted in RDEB patient skin. We demonstrate expression is in-part regulated by endogenous type VII collagen and that, in agreement with previous studies, even small reductions in LH3 expression lead to significantly less secreted LH3 protein. Exogenous type VII collagen did not alter LH3 expression in cultured RDEB keratinocytes and we show that RDEB patients receiving bone marrow transplantation who demonstrate significant increase in type VII collagen do not show increased levels of LH3 at the basement membrane. Our data report a direct link between LH3 and endogenous type VII collagen expression concluding that reduction of LH3 at the basement membrane in patients with RDEB will likely have significant implications for disease progression and therapeutic intervention.

Tumour-stroma crosstalk in the development of squamous cell carcinoma

Squamous cell carcinoma (SCC) represents one of the most frequently diagnosed tumours and contributes significant mortality worldwide. Recent deep sequencing of cancer genomes has identified common mutations in SCC arising across different tissues highlighting perturbation of squamous differentiation as a key event. At the same time significant data have been accumulating to show that common tumour-stroma interactions capable of driving disease progression are also evident when comparing SCC arising in different tissues. We and others have shown altered matrix composition surrounding SCC can promote tumour development. This review focuses on some of the emerging data with particular emphasis on SCC of head and neck and skin with discussion on the potential tumour suppressive properties of a normal microenvironment. Such data indicate that regardless of the extent and type of somatic mutation it is in fact the tumour context that defines metastatic progression.