Collagen XVII promotes dormancy of colorectal cancer cells by activating mTORC2 signaling.

Tumor dormancy is the underpinning for cancer relapse and chemoresistance, leading to massive cancer-related death in colorectal cancer (CRC). However, our comprehension of the mechanisms dictating tumor dormancy and strategies for eliminating dormant tumor cells remains restricted. In this study, we identified that collagen XVII (COL17A1), a hemidesmosomal transmembrane protein, can promote the dormancy of CRC cells. The upregulation of COL17A1 was observed to prolong quiescence periods and diminish drug susceptibility of CRC cells. Mechanistically, COL17A1 acts as a scaffold, enhancing the crosstalk between mTORC2 and Akt, thereby instigating the mTORC2-mediated dormant signaling. Notably, the activation of mTORC2 is contingent upon the intracellular domain of COL17A1, regardless of its ectodomain shedding. Our findings underscore a pivotal role of the COL17A1-mTORC2 axis in CRC dormancy, suggesting that mTORC2-specific inhibitors may hold therapeutic prospects for the eradication of dormant tumor cells.

Levels of type XVII collagen (BP180) ectodomain are elevated in circulation from patients with multiple cancer types and is prognostic for patients with metastatic colorectal cancer.

BACKGROUND: Collagens are the major components of the extracellular matrix (ECM) and are known to contribute to tumor progression and metastasis. There are 28 different types of collagens each with unique functions in maintaining tissue structure and function. Type XVII collagen (BP180) is a type II transmembrane protein that provides stable adhesion between epithelial cells and the underlying basement membrane. Aberrant expression and ectodomain shedding of type XVII collagen have been associated with epithelial damage, tumor invasiveness, and metastasis in multiple tumor types and may consequently be used as a potential (non-invasive) biomarker in cancer and treatment target. METHOD: An ELISA targeting the type XVII collagen ectodomain (PRO-C17) was developed for use in serum. PRO-C17 was measured in a cohort of patients with 11 different cancer types (n = 214) and compared to healthy controls (n = 23) (cohort 1). Based on the findings from cohort 1, PRO-C17 and its association with survival was explored in patients with metastatic colorectal cancer (mCRC) treated with bevacizumab in combination with chemotherapy (n = 212) (cohort 2). RESULTS: PRO-C17 was robust and specific towards the ectodomain of type XVII collagen. In cohort 1, PRO-C17 levels were elevated (p < 0.05) in serum from patients with CRC, kidney, ovarian, bladder, breast, and head and neck cancer compared to healthy controls. PRO-C17 was especially good at discriminating between CRC patients and healthy controls with an AUROC of 0.904. In cohort 2, patients with mCRC and high levels (tertile 3) of PRO-C17 had shorter overall survival (OS) with a median OS of 390 days compared to 539 days for patients with low levels of PRO-C17. When evaluated by multivariate Cox regression analysis, high PRO-C17 was predictive for poor OS independent of risk factors and the tumor fibrosis biomarker PRO-C3. CONCLUSION: PRO-C17 measures the ectodomain of type XVII collagen in serum and is a promising non-invasive biomarker that can aid in understanding tumor heterogeneity as well as elaborate on the role of collagen XVII in tumor progression. Moreover, the findings in the study proposes PRO-C17 as novel biomarker of epithelial damage in specific cancer types including CRC.

Disease Endotypes Predict the Severity of Mucous Membrane Pemphigoid.

Mucous membrane pemphigoid is an autoimmune disease with variable clinical presentation and multiple autoantigens. To determine whether disease endotypes could be identified on the basis of the pattern of serum reactivity, the clinical and diagnostic information of 70 patients with mucous membrane pemphigoid was collected, and reactivity to dermal or epidermal antigens, using indirect immunofluorescence, and specific reactivity to bullous pemphigoid (BP) autoantigens BP180 and BP230, collagen VII, and laminin 332 were evaluated. Most patients had lesions at multiple mucosae, with the most prevalent being oropharyngeal (mouth, gingiva, pharynx; 98.6%), followed by ocular (38.6%), nasal (32.9%), genital or anal (31.4%), laryngeal (20%), and esophageal (2.9%) sites and skin (45.7%). Autoantigen profiling identified BP180 (71%) as the most common autoantigen, followed by laminin 332 (21.7%), collagen VII (13%), and BP230 IgG (11.6%). Reactivity to dermal antigens predicted a more severe disease characterized by a higher number of total sites involved, especially high-risk sites, and a decreased response to rituximab. In most cases, identification of dermal indirect immunofluorescence reactivity is an accurate predictor of disease course; however, confirmation of laminin 332 reactivity is important, with dermal indirect immunofluorescence positivity because of an increased risk of solid tumors. In addition, the ocular mucosae should be monitored in patients with IgA on direct immunofluorescence.

What's new in the pathogeneses and triggering factors of bullous pemphigoid.

Bullous pemphigoid (BP) is a subepidermal blistering disease induced by autoantibodies to type XVII collagen (COL17, also called BP180) and BP230. Previous studies using patients' samples and animal disease models elucidated the complement-dependent and complement-independent pathways of blister formation, the pathogenic roles of immune cells (T and B cells, macrophages, mast cells, neutrophils, eosinophils), and the pathogenicity of IgE autoantibodies in BP. This review introduces the recent progress on the mechanism behind the epitope-spreading phenomenon in BP, which is considered to be important to understand the chronic and intractable disease course of BP, and the pathogenicity of anti-BP230 autoantibodies, mainly focusing on studies that used active disease models. To clarify the pathogenesis of BP, the mechanism behind the breakdown of immune tolerance to BP antigens should be investigated. Recent studies using various experimental models have revealed important roles for regulatory T cells in the maintenance of self-tolerance to COL17 and BP230 as well as in the suppression of inflammation triggered by the binding of antibodies to COL17. Notably, physical stresses such as trauma, thermal burns, bone fractures, irradiation and ultraviolet exposure, some pathologic conditions such as neurological diseases and hematological malignancies, and the use of dipeptidyl peptidase-IV inhibitors and immune checkpoint inhibitors have been reported as triggering factors for BP. These factors and certain underlying conditions such as genetic background, regulatory T-cell dysfunction or aging might synergistically affect some individuals and eventually induce BP. Further studies on the breakdown of self-tolerance and on the identification of key molecules that are relevant to blister formation and inflammation may expand our understanding of BP's etiology and may lead to the development of novel therapeutic approaches.

[Effects of collagen type â ©â ¦ α1 on epidermal stem cells in aging skin and the microRNA intervention mechanism].

Objective: To investigate the expression and function of collagen type ⅩⅦ α1 (COL17α1) in aging mouse skin and its effect on the stemness and proliferation of human epidermal stem cells (ESCs), and to explore the mechanism of related microRNA (miR) in intervening the expression of COL17α1 of human ESC. Methods: The method of experimental research was used. Twelve 2-month-old (young) and twelve 24-month-old (aged) male C57BL/6J mice were selected, and full-thickness skin samples from their upper back were taken for follow-up detection. After hematoxylin-eosin staining of the full-thickness skin samples of young mice and aged mice, the structure of the epidermis was observed and the thickness of the epidermis was measured; the morphology of epidermal basement membrane and hemidesmosomes were observed by transmission electron microscopy, and the hemidesmosomes were counted; the mRNA and protein expressions of COL17α1 were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting respectively, and the protein expression and distribution of COL17α1 was observed and detected by immunofluorescence method. The fresh foreskin tissue discarded after surgery was obtained from 3 healthy men aged 20-30 years who underwent circumcision at the Fourth Medical Center of PLA General Hospital, ESCs were extracted and well-grown cells were wsed for follow-up experiments. According to the random number table (the same grouping method below), ESCs were divided into blank control group, transfection reagent control group, empty vector plasmid group, and COL17α1 knockdown plasmid group with corresponding treatment. After 48 hours of culture, the mRNA expression of COL17α1 was detected by real-time fluorescent quantitative RT-PCR, the protein expressions of COL17α1 and cytokeratin 14 (CK14) were detected by Western blotting, and the cell proliferation level was detected by cell counting kit 8. miRs that might act on the 3' non-coding region of COL17α1 mRNA were screened through DIANA, miRTarBase, miRNAMap, TargetScan, and microRNA databases. The ESCs were divided into negative control group transfected with miR mimic negative control and each miR mimic group transfected with each of the previously screened miR mimics. Forty-eight hours after transfection, the protein expression of COL17α1 was detected by Western blotting. Based on the sequencing data set GSE114006 in Gene Expression Omnibus (GEO), the GEO2R tool was used to statistically analyze the expression of the previously screened miRs that could cause the reduction of COL17α1 protein expression in the skin of 30 young (18-25 years old) and 30 elderly (>70 years old) human skins. The full-thickness skin samples of young mice and aged mice were taken, and the expressions of increased miRs in the aforementioned aged human skin were detected by real-time fluorescent quantitative RT-PCR. Two batches of human ESCs were taken, the first batch was divided into COL17α1 wild type+miR-203b-3p negative control group and COL17α1 wild type+miR-203b-3p mimic group, and the second batch was divided into COL17α1 mutant+miR-203b-3p negative control group and COL17α1 mutant+miR-203b-3p mimic group. Each group of ESC was transfected with corresponding sequences respectively. Forty-eight hours later, the luciferase reporter gene detection kit was used to detect the gene expression level of COL17α1. The number of samples in the tissue experiment was 6, and the number of samples in the cell experiment was 3. Data were statistically analyzed with independent sample t test, one-way analysis of variance, least significant difference test or Dunnett's test, Mann-Whitney U test or Kruskal-Wallis H test. Results: Compared with those of young mice, the boundary between the epidermis and the dermis of the aged mice skin was blurred and the cell layers were less, and the thickness of epidermis was significantly thinner (Z=-2.88, P<0.01); the morphology of basement membrane was discontinuous, with less unevenly distributed hemidesmosomes at the epidermis-dermis junction, and the number of hemidesmosomes was significantly reduced (Z=-2.91, P<0.01); the mRNA and protein expression levels of COL17α1 in the skin of aged mice were significantly decreased (with t values of 10.61 and 6.85, respectively, P<0.01). Compared with those of young mice, the protein expression of COL17α1 in the basal layer of epidermis and the bulb of hair follicle in the skin of aged mice was significantly decreased (Z=-2.24, P<0.05). After 48 hours of culture, the protein expression levels of COL17α1 in ESCs of blank control group, transfection reagent control group, empty vector plasmid group, and COL17α1 knockdown plasmid group were 1.00±0.27, 1.12±0.21, 1.13±0.23, and 0.42±0.18, respectively. Compared with those of blank control group, the mRNA and protein expression levels of COL17α1, the protein expression level of CK14, and the proliferation level of ESCs in transfection reagent control group and empty vector plasmid group did not change significantly (P>0.05), while these indexes in COL17α1 knockdown plasmid group were significantly decreased (P<0.05 or P<0.01). miR-203a-3p, miR-203b-3p, miR-512-5p, miR-124-3p, miR-28-5p, miR-590-3p, and miR-329-5p might bind to the 3' non-coding region of COL17α1 mRNA. Forty-eight hours after transfection, compared with 1.000±0.224 in negative control group, the protein expression level of COL17α1 in ESCs of miR-329-5p mimic group, miR-203b-3p mimic group, and miR-203a-3p mimic group decreased significantly (0.516±0.188, 0.170±0.025, and 0.235±0.025, with t values of 3.17, 5.43, and 5.07, respectively, P<0.05 or P<0.01). Only the expression level of miR-203b-3p in the skin of the elderly was significantly higher than that of the young (t=3.27, P<0.01). The expression level of miR-203b-3p in the skin of aged mice was significantly higher than that of young mice (Z=-2.88, P<0.01). Forty-eight hours after transfection, the gene expression level of COL17α1 in ESCs of COL17α1 wild type+miR-203b-3p mimic group was significantly lower than that of COL17α1 wild type+miR-203b-3p negative control group (t=7.66, P<0.01). The gene expression level of COL17α1 in ESCs of COL17α1 mutant+miR-203b-3p mimic group was similar to that of COL17α1 mutant+miR-203b-3p negative control group (P>0.05). Conclusions: The mRNA and protein expression levels of COL17α1 decrease with age increasing in mice, which may lead to the detachment of mouse ESC from the epidermal basement membrane. Decreased expression of COL17α1 can inhibit the expression of CK14 and ESC proliferation, which may be responsible for the thinning of the epidermis and slower wound healing in aged human skin. The increased expression of miR-203b-3p in aged mouse skin can target and bind to the 3' non-coding region of COL17α1 mRNA, hindering the post-transcriptional translation process, thus resulting in decreased COL17α1 protein expression.

A Case of Anti-BP180-type Mucous Membrane Pemphigoid with IgG and IgA Autoantibodies Showing Distinct Reactivities.

Dear Editor, Mucous membrane pemphigoid (MMP) is an autoimmune blistering disease characterized by erosive mucosal lesions mainly on the oral and ocular mucosae (1). We report a case of oral and ocular anti-BP180-type MMP with variable IgG and IgA reactivities and underlying dementia. An 84-year-old Japanese man presented with a 4-year history of erosions in the oral cavity and on the conjunctivae, with progressive vision impairment. The medical history included benign prostatic hyperplasia, cataract, sinusitis, and dementia. Physical examination revealed erosions and white atrophic scars along the gingival mucosa and on the hard palate (Figure 1, a, b). Conjunctival inflammation and corneal scarring were also observed only on the left eye (Figure 1, c, d). No lesions were observed on the skin or on any other mucosae. A skin biopsy from the patient's oral mucosa showed lymphocytic infiltration in the superficial dermis without apparent subepithelial blister. Direct immunofluorescence showed linear depositions of IgG, IgA, and C3 at the epithelial basement membrane zone (Figure 1, e-g). Circulating IgG and IgA autoantibodies were not detected by indirect immunofluorescence of normal human skin, while circulating IgA, but not IgG, autoantibodies were bound to the epidermal side of 1M NaCl-split normal human skin at 1:10 serum dilution (Figure 1, h, i). Commercially available IgG enzyme-linked immunosorbent assays (ELISAs) of BP180 NC16a domain, BP230, and type VII collagen (MBL, Nagoya, Japan) showed negative results. IgG and IgA immunoblotting analyses of six different antigen sources, including BP180 C-terminal domain recombinant protein, were all negative. However, ELISA of full-length BP180 was slightly positive for IgG antibodies (index = 5.79; cut-off <4.64). Immunoblotting analysis of full-length BP180 was negative for both IgG and IgA antibodies (Figure 1, j, k). Immunoblotting analysis of hemidesmosome-rich fraction was negative for both IgG and IgA antibodies to integrin ß4 (Figure 1, l). Based mainly on the clinical and immunological findings, we established a diagnosis of MMP with IgG and IgA autoantibodies, likely reactive with BP180. Because the patient refused systemic treatments, we prescribed a mouth rinse sodium gualenate hydrate and eyedrops of fluorometholone and purified sodium hyaluronate, which did not improve the oral and ocular mucosal symptoms during the 8 month follow-up period (Figure 1, m, n). Both IgG and IgA autoantibodies in anti-BP180-type MMP tend to react with the C-terminal domain of BP180 (2), and IgG autoantibodies in 39.7% of MMP patients reactive with the epidermal side of split skin were reported to be positive with BP180 C-terminal domain (3). The full-length BP180 ELISA shows excellent sensitivity for diagnosing BP180-type MMP (4). The different IgG and IgA reactivities among various methods used in the present study may be attributed either to different methodologies (i.e., immunoblotting or ELISA) or to the different substrates, since BP180-type MMP targets various regions of BP180, including the NC16a domain, the C-terminal domain, and the intracytoplasmic region (5). Precise diagnosis for MMP by various immunological methods is critical, because urgent and extensive treatments are necessary for the ocular and laryngeal lesions, which may result in loss of eyesight and airway obstruction, respectively. Acknowledgments: We express our gratitude to Ms. Mako Mine and Dr. Daisuke Hayashi, Department of Dermatology, Osaka City University Graduate School of Medicine in Osaka, Japan for the HD-rich fraction immunoblotting analysis, and Dr. Yoshiaki Hirako, Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan for the preparation of the HD-rich fraction sample. This work was supported by JSPS KAKENHI Grant Number JP20k08684 and the Hirosaki University Research Support System.

Use of gliptins reduces levels of SDF-1/CXCL12 in bullous pemphigoid and type 2 diabetes, but does not increase autoantibodies against BP180 in diabetic patients.

The use of dipeptidyl peptidase 4 (DPP4) inhibitors, (also known as gliptins), is associated with an increased risk of bullous pemphigoid (BP), an autoimmune blistering skin disease. To explore the mechanism behind gliptin-associated BP we investigated circulating autoantibodies against the major BP autoantigen BP180 in serum samples from patients with type 2 diabetes (T2D) with preceding gliptin medication (n = 136) or without (n = 136). Sitagliptin was the most frequently prescribed gliptin (125/136 patients). Using an ELISA assay, we showed that IgG autoantibodies against the immunodominant NC16A domain of BP180 were found in 5.9% of gliptin treated and in 6.6% of non-gliptin treated T2D patients. We found that 28% of gliptin treated patients had IgG autoantibodies recognizing the native full-length BP180 in ELISA, but among non-gliptin treated the seropositivity was even higher, at 32%. Further ELISA analysis of additional serum samples (n = 57) found no major changes in the seropositivity against BP180 during a follow-up period of about nine years. In immunoblotting, full-length BP180 was recognized by 71% of gliptin treated and 89% of non-gliptin treated T2D patients, but only by 46% of the age-and sex-matched controls. The chemokine stromal derived factor-1(SDF-1/CXCL12) is one of the major substrates of DPP4. Immunostainings showed that the expression of SDF-1 was markedly increased in the skin of BP patients, but not affected by prior gliptin treatment. We found that the use of gliptins decreased the serum level of SDF-1α in both BP and T2D patients. Our results indicate that the autoantibodies against the linear full-length BP180 are common in patients with T2D, but seropositivity is unaffected by the use of sitagliptin.

Serum autoantibody reactivity in bullous pemphigoid is associated with neuropsychiatric disorders and the use of antidiabetics and antipsychotics: a large, prospective cohort study.

BACKGROUND: Bullous pemphigoid (BP), the by far most frequent autoimmune blistering skin disease (AIBD), is immunopathologically characterized by autoantibodies against the two hemidesmosomal proteins BP180 (collagen type XVII) and BP230 (BPAG1 or dystonin). Several comorbidities and potentially disease-inducing medication have been described in BP, yet a systematic analysis of these clinically relevant findings and autoantibody reactivities has not been performed. OBJECTIVE: To determine associations of autoantibody reactivities with comorbidities and concomitant medication. METHODS: In this prospective multicenter study, 499 patients diagnosed with BP in 16 European referral centers were included. The relation between anti-BP180 NC16A and anti-BP230 IgG ELISA values at the time of diagnosis as well as comorbidities and concomitant medication collected by a standardized form were analysed. RESULTS: An association between higher serum anti-BP180 reactivity and neuropsychiatric but not atopic and metabolic disorders was observed as well as with the use of insulin or antipsychotics but not with dipeptidyl peptidase-4 (DPP4) inhibitors, inhibitors of platelet aggregation and L-thyroxine. The use of DPP4 inhibitors was associated with less anti-BP180 and anti-BP230 reactivity compared with BP patients without these drugs. This finding was even more pronounced when compared with diabetic BP patients without DPP4 inhibitors. Associations between anti-BP180 and anti-BP230 reactivities were also found in patients using insulin and antipsychotics, respectively, compared with patients without this medication, but not for the use of inhibitors of platelet aggregation, and L-thyroxine. CONCLUSION: Taken together, these data imply a relation between autoantibody reactivities at the time of diagnosis and both neuropsychiatric comorbidities as well as distinct concomitant medication suggesting a link between the pathological immune mechanisms and clinical conditions that precede the clinically overt AIBD.

Cell-matrix interface regulates dormancy in human colon cancer stem cells.

Cancer relapse after chemotherapy remains a main cause of cancer-related death. Although the relapse is thought to result from the propagation of resident cancer stem cells1, a lack of experimental platforms that enable the prospective analysis of cancer stem cell dynamics with sufficient spatiotemporal resolution has hindered the testing of this hypothesis. Here we develop a live genetic lineage-tracing system that allows the longitudinal tracking of individual cells in xenotransplanted human colorectal cancer organoids, and identify LGR5+ cancer stem cells that exhibit a dormant behaviour in a chemo-naive state. Dormant LGR5+ cells are marked by the expression of p27, and intravital imaging provides direct evidence of the persistence of LGR5+p27+ cells during chemotherapy, followed by clonal expansion. Transcriptome analysis reveals that COL17A1-a cell-adhesion molecule that strengthens hemidesmosomes-is upregulated in dormant LGR5+p27+ cells. Organoids in which COL17A1 is knocked out lose the dormant LGR5+p27+ subpopulation and become sensitive to chemotherapy, which suggests that the cell-matrix interface has a role in the maintenance of dormancy. Chemotherapy disrupts COL17A1 and breaks the dormancy in LGR5+p27+ cells through FAK-YAP activation. Abrogation of YAP signalling prevents chemoresistant cells from exiting dormancy and delays the regrowth of tumours, highlighting the therapeutic potential of YAP inhibition in preventing cancer relapse. These results offer a viable therapeutic approach to overcome the refractoriness of human colorectal cancer to conventional chemotherapy.

Bullous pemphigoid and milia: prevalence and clinical laboratory findings in a Brazilian sample.

BACKGROUND: Bullous pemphigoid (BP) associated with milia lesions has been increasingly reported, but its prevalence has not been reported in a Brazilian BP population yet. OBJECTIVES: To describe the occurrence and clinical-laboratorial findings of BP-milia association in a southeastern Brazilian sample. METHODS: A descriptive study based on the medical charts of 102 BP patients was accomplished. Clinical and laboratory data of BP-milia patients were compiled. Total serum IgE measurements, immunoblot assays based on basement membrane zone antigens, and HLA-DQ alleles typing were performed. RESULTS: Milia was evident in 8 (7.8%) BP patients, five males, aged between 46 and 88 years. Increased total IgE levels were determined in 7 (87.5%) of the eight patients. In five of eight patients, immunoblotting showed IgG reactivity against the BP180-NC16a domain but not against collagen VII or laminin-332; it also revealed reactivity against the BP180 C-terminal domain or LAD-1, or both in four of them. The HLA-DQB1*03:01 and HLA-DQA1*05:05 alleles were identified in three of five BP-milia patients. Moreover, three of five cases presented the HLA-DQB1*06 allelic group. STUDY LIMITATIONS: HLA determination was performed in five patients. CONCLUSIONS: Milia formation in BP patients seems to be less uncommon than previously admitted. Laboratory data revealed increased IgE; autoantibodies against the BP180 C-terminal domain or LAD-1, or both; and the HLA-DQB1*06 allelic group, described for the BP-milia association. Careful determination of antibodies against basement membrane zone molecules and HLA characterization in different populations may provide further insights into this association.

Type XX Collagen Is Elevated in Circulation of Patients with Solid Tumors.

In the tumor microenvironment, the extracellular matrix (ECM) has been recognized as an important part of cancer development. The dominant ECM proteins are the 28 types of collagens, each with a unique function in tissue architecture. Type XX collagen, however, is poorly characterized, and little is known about its involvement in cancer. We developed an ELISA quantifying type XX collagen, named PRO-C20, using a monoclonal antibody raised against the C-terminus. PRO-C20 and PRO-C1, an ELISA targeting the N-terminal pro-peptide of type I collagen, was measured in sera of 219 patients with various solid cancer types and compared to sera levels of 33 healthy controls. PRO-C20 was subsequently measured in a separate cohort comprising 36 patients with pancreatic ductal adenocarcinoma (PDAC) and compared to 20 healthy controls and 11 patients with chronic pancreatitis. PRO-C20 was significantly elevated in all cancers tested: bladder, breast, colorectal, head and neck, kidney, lung, melanoma, ovarian, pancreatic, prostate, and stomach cancer (p < 0.01−p < 0.0001). PRO-C1 was only elevated in patients with ovarian cancer. PRO-C20 could discriminate between patients and healthy controls with AUROC values ranging from 0.76 to 0.92. Elevated levels were confirmed in a separate cohort of patients with PDAC (p < 0.0001). High PRO-C20 levels (above 2.57 nM) were predictive of poor survival after adjusting for the presence of metastasis, age, and sex (HR: 4.25, 95% CI: 1.52−11.9, p-value: 0.006). Circulating type XX collagen is elevated in sera of patients with various types of cancer and has prognostic value in PDAC. If validated, PRO-C20 may be a novel biomarker for patients with solid tumors and can help understand the ECM biology of cancer.

Bullous Pemphigoid-Associated Mortality Rate in a Canadian Tertiary Referral Centre.

BACKGROUND: Bullous pemphigoid (BP) is the most common autoimmune blistering disorder in adults. Most individuals with BP are over the age of 60. Its worldwide incidence has been increasing owing to population aging. Observational studies published over the last 2 decades highlight the non-negligible, albeit variable overall mortality of BP patients, with reported 12-month mortality rates of 10.8% to 40.8%, and 24-month mortality rates of 20.1% to 51.0%. Data in the Canadian population are lacking. OBJECTIVES: We aimed to estimate the 12- and 24-month overall mortality rate of Canadian patients diagnosed with BP, and to identify independent risk factors adversely impacting overall survival. METHODS: A retrospective cohort study of 166 patients with a diagnosis of BP between 2010 and 2020 was carried out at Centre hospitalier de l'Université de Montréal (CHUM), a tertiary referral center in Montréal, Québec, Canada. Cumulative mortality was calculated using the Kaplan-Meier estimator, and independent prognostic factors were identified using a Cox proportional hazards regression model. RESULTS: Eighty-five patients (51.2%) in our study were female. The median age was 79.1 years old, and 80 patients (48.2%) were 80 years old or older. Mortality at 12 and 24 months in our study cohort was 16.2% (CI95% = 10.5 - 21.8) and 27.6% (CI95% = 20.5 - 34.7), respectively. In a multivariate analysis, patients who were male, 80 years old or older, and/or had a diagnosis of a major neurocognitive disorder had a poorer overall survival. CONCLUSIONS: The all-cause mortality of patients with BP in our study population compared favorably with international data reported in the literature.

The role of network-forming collagens in cancer progression.

Collagens are the main components of extracellular matrix in the tumor microenvironment. Both fibrillar and nonfibrillar collagens are involved in tumor progression. The nonfibrillar network-forming collagens such as type IV and type VIII collagens are frequently overexpressed in various types of human cancers, which promotes tumor cell proliferation, adhesion, invasion, metastasis and angiogenesis. Studies on the roles of these collagens have shed light on the mechanisms underpinning the effects of this protein family. Future research has to explicit the role of network-forming collagens with respect to cancer progression and treatment. Herein, we review the regulation of network-forming collagens expression in cancer; the roles of network-forming collagens in tumor invasion, metastasis and angiogenesis; and the clinical significance of network-forming collagens expression in cancer patients.

EGFR-mediated epidermal stem cell motility drives skin regeneration through COL17A1 proteolysis.

Skin regenerative capacity declines with age, but the underlying mechanisms are largely unknown. Here we demonstrate a functional link between epidermal growth factor receptor (EGFR) signaling and type XVII collagen (COL17A1) proteolysis on age-associated alteration of keratinocyte stem cell dynamics in skin regeneration. Live-imaging and computer simulation experiments predicted that human keratinocyte stem cell motility is coupled with self-renewal and epidermal regeneration. Receptor tyrosine kinase array identified the age-associated decline of EGFR signaling in mouse skin wound healing. Culture experiments proved that EGFR activation drives human keratinocyte stem cell motility with increase of COL17A1 by inhibiting its proteolysis through the secretion of tissue inhibitor of metalloproteinases 1 (TIMP1). Intriguingly, COL17A1 directly regulated keratinocyte stem cell motility and collective cell migration by coordinating actin and keratin filament networks. We conclude that EGFR-COL17A1 axis-mediated keratinocyte stem cell motility drives epidermal regeneration, which provides a novel therapeutic approach for age-associated impaired skin regeneration.

Collagen XVII inhibits breast cancer cell proliferation and growth through deactivation of the AKT/mTOR signaling pathway.

Collagen XVII (COL17), a cell-matrix adhesion protein, has been found to be suppressed in breast cancer. Our previous data demonstrated a preventive role of COL17 in breast cancer invasiveness. The present study used the stable COL17-overexpressing MCF7 and MDA-MB-231 cells to reveal an anti-proliferative effect of COL17 on breast cancer cell through mTOR deactivation. Cell proliferation was negatively correlated with the expression level of COL17 in a concentration-dependent manner in both conventional and three-dimensional (3D) culture systems. The correlation was confirmed by decreased expression of the proliferative marker Ki67 in COL17-expressing cells. In addition, overexpression of COL17 reduced the clonogenicity and growth of the cells. We demonstrated that COL17 affects the AKT/mTOR signaling pathway by deactivation of AKT, mTOR and downstream effectors, particularly 4EBP1. Moreover, mice xenografted with high COL17-expressing cells exhibited delayed tumor progression and prolonged survival time. The high expression of COL17A1 gene encoding COL17 is associated with low-proliferation tumors, extended tumor-free period, and overall survival of breast cancer patients. In conclusion, our results revealed the novel function of COL17 using in vitro and in vivo models and elucidated the related pathway in breast cancer cell growth and proliferation.

The CD44/COL17A1 pathway promotes the formation of multilayered, transformed epithelia.

At the early stage of cancer development, oncogenic mutations often cause multilayered epithelial structures. However, the underlying molecular mechanism still remains enigmatic. By performing a series of screenings targeting plasma membrane proteins, we have found that collagen XVII (COL17A1) and CD44 accumulate in RasV12-, Src-, or ErbB2-transformed epithelial cells. In addition, the expression of COL17A1 and CD44 is also regulated by cell density and upon apical cell extrusion. We further demonstrate that the expression of COL17A1 and CD44 is profoundly upregulated at the upper layers of multilayered, transformed epithelia in vitro and in vivo. The accumulated COL17A1 and CD44 suppress mitochondrial membrane potential and reactive oxygen species (ROS) production. The diminished intracellular ROS level then promotes resistance against ferroptosis-mediated cell death upon cell extrusion, thereby positively regulating the formation of multilayered structures. To further understand the functional role of COL17A1, we performed comprehensive metabolome analysis and compared intracellular metabolites between RasV12 and COL17A1-knockout RasV12 cells. The data imply that COL17A1 regulates the metabolic pathway from the GABA shunt to mitochondrial complex I through succinate, thereby suppressing the ROS production. Moreover, we demonstrate that CD44 regulates membrane accumulation of COL17A1 in multilayered structures. These results suggest that CD44 and COL17A1 are crucial regulators for the clonal expansion of transformed cells within multilayered epithelia, thus being potential targets for early diagnosis and preventive treatment for precancerous lesions.

Comorbidities of bullous pemphigoid: A single-center retrospective case-control study from Turkey.

Although significant associations between bullous pemphigoid (BP) and certain comorbidities, primarily subtypes of neurological disorders, have been reported in several populations, it has yet to be demonstrated whether a correlation exists between pre-existing comorbidities and serum titers of anti-BP180 and 230 immunoglobulin G (IgG) antibodies among BP patients. The aim of the current study is to investigate the demographic and clinical features of BP patients in a large series from Turkey, determine the prevalence of pre-existing neurological and systemic disorders, and assess the correlation between the existence of certain comorbidities and basal serum titers of anti-BP180 and 230 IgG autoantibodies. Thus, data from 145 BP patients diagnosed in the study's center between 1987 and 2017 were retrospectively analyzed and compared with 310 age- and sex-matched control subjects. The serum titers of anti-BP 180 and 230 IgG autoantibodies were compared between the patients with and without comorbidities and its subtypes among 55 patients with available serum basal anti-BP levels. Twenty-eight of the BP patients (19.3%) had already been diagnosed with at least one neurological disorder at the onset of BP. According to regression analysis, preexisting neurological disorders (p = 0.017), stroke (p = 0.017), and malignancies (p = 0.005) were found to be higher among the study's BP patients than the controls. The serum titers of anti-BP180 and 230 that were measured at the time of diagnosis were significantly higher in patients with neurological disorders than in patients without neurological disorders (p = 0.042; p = 0.018). Among the pre-existing comorbidities, neurological disorders, particularly stroke, and malignancies were found to be significantly connected to the occurrence of BP in the selected Turkish population. The high titers of serum anti-BP180 and 230 IgG antibodies at the time of BP diagnoses may highlight undiagnosed pre-existing neurological disorders by provoking suspicion.

Case of pemphigoid vegetans with autoantibodies against the BP180 C-terminal domain and BP230 antigen.

Pemphigoid vegetans is a rare variant of bullous pemphigoid characterized by vegetative and purulent lesions of the groin, axillae, thighs, hands, eyelids, and perioral regions. The clinical features and histological findings of pemphigus vegetans and immunohistochemical characteristics of bullous pemphigoid are shown. An 86-year-old woman presented with vegetative lesions in the vulva and groin, and blisters on the head, neck, axillae, and thighs. Although clinically suspected as pemphigus vegetans, skin biopsy showed subepidermal clefts with eosinophil infiltration and eosinophilic pustules in the epidermis. Direct immunofluorescence analysis showed linear deposition of immunoglobulin (Ig)G along the basement membrane zone. Indirect immunofluorescence using 1 mol/L NaCl salt-split skin showed linear deposition of IgG on the epidermal side. Chemiluminescent enzyme immunoassay and enzyme-linked immunosorbent assay were positive for BP180 and BP230. Immunoblotting of recombinant protein of the BP180 C-terminal domain showed positive reactivity. Pemphigoid vegetans was diagnosed and treated successfully with oral corticosteroids. This is the first case of pemphigoid vegetans reported to date with detection of autoantibodies against both BP180 C-terminal domain and BP230.