Asporin Is a Fibroblast-Derived TGF-β1 Inhibitor and a Tumor Suppressor Associated with Good Prognosis in Breast Cancer

Fetal-like reversion in the regenerating intestine is regulated by mesenchymal asporin

Mesenchymal cells and the extracellular matrix (ECM) support epithelium during homeostasis and regeneration. However, the role of the mesenchyme in epithelial conversion into a fetal-like regenerative state after damage is not known. We modeled epithelial regeneration by culturing intestinal epithelium on decellularized small intestinal scaffolds (iECM) and identify asporin (Aspn), an ECM-bound proteoglycan, as a critical mediator of epithelial fetal-like reprogramming. After damage, transient increase in Aspn expression by the pericryptal fibroblasts induces epithelial transforming growth factor β (TGF-β)-signaling via CD44 and promotes timely epithelial reprogramming. Temporal control of Aspn is lost in old mice, and after damage, the persistently high level of Aspn stagnates epithelium in the regenerative state. Increase in Wnt signaling can resolve the stagnated regenerative program of the old epithelium, promoting restoration of tissue function. In summary, we establish a platform for modeling epithelial injury responses ex vivo and show that the mesenchymal Aspn-producing niche modulates tissue repair by regulating epithelial fetal-like reprogramming.

TGFβ-activated Asporin interacts with STMN1 to promote prostate cancer docetaxel chemoresistance and metastasis by upregulating the Wnt/β-catenin signaling pathway

AIMS

Prostate cancer (PCa) remains a significant challenge in oncology due to high rates of drug resistance following standard treatment with docetaxel-based chemotherapy. Asporin (ASPN) has been regarded as an oncogene and its upregulation is closely associated with malignant behavior and poor prognosis in multiple cancers. Studies indicated that abnormal activation of the Wnt/β-catenin signaling pathway is prevalent in PCa. This study investigated the important role of ASPN in regulating Wnt/β-catenin signaling pathway in docetaxel resistance and metastasis of PCa.

METHODS

The impacts of ASPN on the docetaxel chemoresistance and metastasis of PCa cells were investigated in vitro and in vivo assays. Lastly, the underlying mechanism of ASPN was revealed by Western blot, protein immunocoprecipitation, Immunofluorescence, Immunohistochemical staining, liquid chromatography-mass spectrometry, and rescue experiments.

RESULTS

In present study, we reported that ASPN is highly expressed in PCa cells and tissues. Functional and molecular analyses showed that ASPN is activated by TGFβ and interacts with STMN1. ASPN increases the expression of β-catenin and promotes its nuclear accumulation by mediating the activation of the Wnt/β-catenin signaling pathway, thereby enhancing the stemness and epithelial-mesenchymal transition (EMT) of PCa cells, ultimately facilitating the docetaxel resistance and metastasis of PCa cells.

CONCLUSIONS

Our findings identify ASPN as a novel upstream regulatory factor of Wnt/β-catenin signaling pathway, suggesting that targeting the ASPN/STMN1/β-catenin axis could be a promising strategy for PCa intervention.

Extracellular matrix shapes cancer stem cell behavior in breast cancer: a mini review

Today, cancer has become one of the leading global tragedies. It occurs when a small number of cells in the body mutate, causing some of them to evade the body's immune system and proliferate uncontrollably. Even more irritating is the fact that patients with cancers frequently relapse after conventional chemotherapy and radiotherapy, leading to additional suffering. Scientists thereby presume that cancer stem cells (CSCs) are the underlying cause of metastasis and recurrence. In recent years, it was shown that not only can chemotherapy and radiotherapy underperform in the treatment of breast cancer, but they can also increase the number of breast cancer stem cells (BCSCs) that transform regular breast cancer cells into their own population. Such data somewhat support the aforementioned hypothesis. Meanwhile, our understanding of the extracellular matrix (ECM) has changed considerably over the last decade. A lot of studies have bit by bit complemented human knowledge regarding how the ECM greatly shapes the behaviors of BCSCs. In this review, we highlighted the influence on BCSCs exerted by different critical components and biochemical properties of ECM.

Asporin increases the extracellular matrix cross-links and inhibits the cancer cell migration

BackgroundMigrating strategies of the triple-negative breast cancer (TNBC) together with its role in the establishment of tumor microenvironment (TME), supporting metastasis, have been extensively studied. Extracellular matrix (ECM) is a major player for the TME, establishing the 3D spatial networks with interconnected pores necessary for the mechano-physiological function of the cells. Certain collagen aligners and cross-linkers which are necessary for the formation and the stabilization of ECM networks, however, have not been studied either in normal or in abnormal tissues. Complexities in cell-cell and cell-matrix interactions, and different in types and ratios of ECM proteins in a TME challenge to reveal the precise function of a particular protein that is exhibited by special cells and if specifically present in insignificant amount. Cancer-associated fibroblasts (CAFs) predominantly occupy the major stroma of a solid tumor where they deposit extracellular proteins in the excessive amount compared to other tumor-associated cells. For example, the TNBC tumor itself is positive for asporin (ASPN) since CAFs are major ASPN exhibitors. However, the TNBC cells express it insignificantly.ObjectiveThe increase in ECM and its networks suppresses the metastasis.MethodsHere, we studied the expression of collagen type I and ASPN in CAFS and MDA-MB-231 (MM231), and evaluated the role of ASPN in collagen alignment and crosslinking.ResultsTNBC cells have an insignificant expression of ASPN and scanty collagen fibers, some of which aggregate to form the stiff deranged fibers, forming large-size pores in ECM of cancer-cell-dominant outer core of TNBC that support cancer cell invasion and metastasis. Exogenous ASPN and fibroblast-ASPN supported for the collagen alignment and crosslinking that established the small-size pores in the ECM, inhibiting the cancer cell invasion.ConclusionsThe collagen aligner and the cross-linker, ASPN increases the ECM networks and decreases the migration, and this preliminary study provides the hope that ASPN might be used as an anti-metastatic drug after its confirmation through extensive studies in animal, and positive outcomes through preclinical trials.

Comprehensive investigation of proteoglycan gene expression in breast cancer: Discovery of a unique proteoglycan gene signature linked to the malignant phenotype

Solid tumors present a formidable challenge in oncology, necessitating innovative approaches to improve therapeutic outcomes. Proteoglycans, multifaceted molecules within the tumor microenvironment, have garnered attention due to their diverse roles in cancer progression. Their unique ability to interact with specific membrane receptors, growth factors, and cytokines provides a promising avenue for the development of recombinant proteoglycan-based therapies that could enhance the precision and efficacy of cancer treatment. In this study, we performed a comprehensive analysis of the proteoglycan gene landscape in human breast carcinomas. Leveraging the available wealth of genomic and clinical data regarding gene expression in breast carcinoma and using a machine learning model, we identified a unique gene expression signature composed of five proteoglycans differentially modulated in the tumor tissue: Syndecan-1 and asporin (upregulated) and decorin, PRELP and podocan (downregulated). Additional query of the breast carcinoma data revealed that serglycin, previously shown to be increased in breast carcinoma patients and mouse models and to correlate with a poor prognosis, was indeed decreased in the vast majority of breast cancer patients and its levels inversely correlated with tumor progression and invasion. This proteoglycan gene signature could provide novel diagnostic capabilities in breast cancer biology and highlights the need for further utilization of publicly available datasets for the clinical validation of preclinical experimental results.

The prognostic implications of podoplanin in cancer-associated fibroblasts and PD-L1 expression in high-grade neuroendocrine carcinoma of the lung

OBJECTIVES

Podoplanin (PDPN) expression in cancer-associated fibroblasts (CAFs) (CAF-PDPN) is considered a poor prognostic factor in nonsmall cell lung cancer, but little is known about its clinical significance in high-grade neuroendocrine carcinoma of the lung (HGNEC). This study examines the association between CAF-PDPN and stromal programmed death-ligand 1 (PD-L1) expression and the prognostic implications of CAF-PDPN and PD-L1 expression status in surgically resected HGNEC patients.

METHODS

Immunohistochemical analyses were performed on 121 resected HGNEC specimens using antibodies against PDPN and PD-L1. Correlations between CAF-PDPN, stromal PD-L1 expression, and clinicopathologic features and their implications for survival were analyzed statistically.

RESULTS

There were substantially more large-cell neuroendocrine carcinomas in the stromal PD-L1-positive group and more vascular invasion in the tumoral PD-L1-positive group. PDPN expression in CAF was moderately correlated with stromal PD-L1 expression (ρ = 0.567, p < 0.001). In a survival analysis combining CAF-PDPN and stromal PD-L1 status, the 5-year RFS rates for Group A: CAF-PDPN (+)/stromal PD-L1 (+), Group B: CAF-PDPN (+)/stromal PD-L1 (-), Group C: CAF-PDPN (-)/stromal PD-L1 (+), and Group D: CAF-PDPN (-)/stromal PD-L1 (-) were 62.0%, 46.8%, 17.5%, and 20.2%, respectively, with corresponding 5-year OS rates of 76.6%, 69.2%, 27.0%, and 25.3%. The log-rank test showed statistically significant differences among the groups in RFS (p < 0.001) and OS (p < 0.001).

CONCLUSIONS

There is a correlation between CAF-PDPN and tumoral/stromal PD-L1 expression, and positive status for either CAF-PDPN or stromal PD-L1 expression could be an independent favorable prognostic factor in surgically resected HGNEC patients.

Integrative Multiomics in the Lung Reveals a Protective Role of Asporin in Pulmonary Arterial Hypertension

BACKGROUND

Integrative multiomics can elucidate pulmonary arterial hypertension (PAH) pathobiology, but procuring human PAH lung samples is rare.

METHODS

We leveraged transcriptomic profiling and deep phenotyping of the largest multicenter PAH lung biobank to date (96 disease and 52 control) by integration with clinicopathologic data, genome-wide association studies, Bayesian regulatory networks, single-cell transcriptomics, and pharmacotranscriptomics.

RESULTS

We identified 2 potentially protective gene network modules associated with vascular cells, and we validated ASPN, coding for asporin, as a key hub gene that is upregulated as a compensatory response to counteract PAH. We found that asporin is upregulated in lungs and plasma of multiple independent PAH cohorts and correlates with reduced PAH severity. We show that asporin inhibits proliferation and transforming growth factor-β/phosphorylated SMAD2/3 signaling in pulmonary artery smooth muscle cells from PAH lungs. We demonstrate in Sugen-hypoxia rats that ASPN knockdown exacerbated PAH and recombinant asporin attenuated PAH.

CONCLUSIONS

Our integrative systems biology approach to dissect the PAH lung transcriptome uncovered asporin as a novel protective target with therapeutic potential in PAH.

Targeting the devil: Strategies against cancer-associated fibroblasts in colorectal cancer

Cancer-associated fibroblasts (CAFs), as significant constituents of the tumor microenvironment (TME), play a pivotal role in the progression of cancers, including colorectal cancer (CRC). In this comprehensive review, we presented the origins and activation mechanisms of CAFs in CRC, elaborating on how CAFs drive tumor progression through their interactions with CRC cells, immune cells, vascular endothelial cells, and the extracellular matrix within the TME. We systematically outline the intricate web of interactions among CAFs, tumor cells, and other TME components, and based on this complex interplay, we summarize various therapeutic strategies designed to target CAFs in CRC. It is also essential to recognize that CAFs represent a highly heterogeneous group, encompassing various subtypes such as myofibroblastic CAF (myCAF), inflammatory CAF (iCAF), antigen-presenting CAF (apCAF), vessel-associated CAF (vCAF). Herein, we provide a summary of studies investigating the heterogeneity of CAFs in CRC and the characteristic expression patterns of each subtype. While the majority of CAFs contribute to the exacerbation of CRC malignancy, recent findings have revealed specific subtypes that exert inhibitory effects on CRC progression. Nevertheless, the comprehensive landscape of CAF heterogeneity still awaits exploration. We also highlight pivotal unanswered questions that need to be addressed before CAFs can be recognized as feasible targets for cancer treatment. In conclusion, the aim of our review is to elucidate the significance and challenges of advancing in-depth research on CAFs, while outlining the pathway to uncover the complex roles of CAFs in CRC and underscore their significant potential as therapeutic targets.

Tumor Cell Stemness and Stromal Cell Features Contribute to Oral Cancer Outcome Disparity in Black Americans

Black Americans (BAs) with head and neck cancer (HNC) have worse survival outcomes compared to the White patients. While HNC disparities in patient outcomes for BAs have been well recognized, the specific drivers of the inferior outcomes remain poorly understood. Here, we investigated the biologic features of patient tumor specimens obtained during the surgical treatment of oral cancers and performed a follow-up study of the patients' post-surgery recurrences and metastases with the aim to explore whether tumor biologic features could be associated with the poorer outcomes among BA patients compared with White American (WA) patients. We examined the tumor stemness traits and stromal properties as well as the post-surgery recurrence and metastasis of oral cancers among BA and WA patients. It was found that high levels of tumor self-renewal, invasion, tumorigenesis, metastasis, and tumor-promoting stromal characteristics were linked to post-surgery recurrence and metastasis. There were more BA than WA patients demonstrating high stemness traits and strong tumor-promoting stromal features in association with post-surgery tumor recurrences and metastases, although the investigated cases displayed clinically comparable TNM stages and histological grades. These findings demonstrated that the differences in tumor stemness and stromal property among cancers with comparable clinical diagnoses contribute to the outcome disparity in HNCs. More research is needed to understand the genetic and molecular basis of the biologic characteristics underlying the inferior outcomes among BA patients, so that targeting strategies can be developed to reduce HNC disparity.

Low- and High-Grade Glioma-Associated Vascular Cells Differentially Regulate Tumor Growth

A key feature distinguishing high-grade glioma (HG) from low-grade glioma (LG) is the extensive neovascularization and endothelial hyperproliferation. Prior work has shown that tumor-associated vasculature from HG is molecularly and functionally distinct from normal brain vasculature and expresses higher levels of protumorigenic factors that promote glioma growth and progression. However, it remains unclear whether vessels from LG also express protumorigenic factors, and to what extent they functionally contribute to glioma growth. Here, we profile the transcriptomes of glioma-associated vascular cells (GVC) from IDH-mutant (mIDH) LG and IDH-wild-type (wIDH) HG and show that they exhibit significant molecular and functional differences. LG-GVC show enrichment of extracellular matrix-related gene sets and sensitivity to antiangiogenic drugs, whereas HG-GVC display an increase in immune response-related gene sets and antiangiogenic resistance. Strikingly, conditioned media from LG-GVC inhibits the growth of wIDH glioblastoma cells, whereas HG-GVC promotes growth. In vivo cotransplantation of LG-GVC with tumor cells reduces growth, whereas HG-GVC enhances tumor growth in orthotopic xenografts. We identify ASPORIN (ASPN), a small leucine-rich repeat proteoglycan, highly enriched in LG-GVC as a growth suppressor of wIDH glioblastoma cells in vitro and in vivo. Together, these findings indicate that GVC from LG and HG are molecularly and functionally distinct and differentially regulate tumor growth. Implications: This study demonstrated that vascular cells from IDH-mutant LG and IDH-wild-type HG exhibit distinct molecular signatures and have differential effects on tumor growth via regulation of ASPN-TGFβ1-GPM6A signaling.

Biological Activity of Natural and Synthetic Peptides as Anticancer Agents

Cancer is one of the leading causes of morbidity and death worldwide, making it a serious global health concern. Chemotherapy, radiotherapy, and surgical treatment are the most used conventional therapeutic approaches, although they show several side effects that limit their effectiveness. For these reasons, the discovery of new effective alternative therapies still represents an enormous challenge for the treatment of tumour diseases. Recently, anticancer peptides (ACPs) have gained attention for cancer diagnosis and treatment. ACPs are small bioactive molecules which selectively induce cancer cell death through a variety of mechanisms such as apoptosis, membrane disruption, DNA damage, immunomodulation, as well as inhibition of angiogenesis, cell survival, and proliferation pathways. ACPs can also be employed for the targeted delivery of drugs into cancer cells. With over 1000 clinical trials using ACPs, their potential for application in cancer therapy seems promising. Peptides can also be utilized in conjunction with imaging agents and molecular imaging methods, such as MRI, PET, CT, and NIR, improving the detection and the classification of cancer, and monitoring the treatment response. In this review we will provide an overview of the biological activity of some natural and synthetic peptides for the treatment of the most common and malignant tumours affecting people around the world.

Asporin and CD109, expressed in the injured neonatal spinal cord, attenuate axonal re-growth in vitro

Axonal regeneration is restricted in adults and causes irreversible motor dysfunction following spinal cord injury (SCI). In contrast, neonates have prominent regenerative potential and can restore their neural function. Although the distinct cellular responses in neonates have been studied, how they contribute to neural recovery remains unclear. To assess whether the secreted molecules in neonatal SCI can enhance neural regeneration, we re-analyzed the previously performed single-nucleus RNA-seq (snRNA-seq) and focused on Asporin and Cd109, the highly expressed genes in the injured neonatal spinal cord. In the present study, we showed that both these molecules were expressed in the injured spinal cords of adults and neonates. We treated the cortical neurons with recombinant Asporin or CD109 to observe their direct effects on neurons in vitro. We demonstrated that these molecules enhance neurite outgrowth in neurons. However, these molecules did not enhance re-growth of severed axons. Our results suggest that Asporin and CD109 influence neurites at the lesion site, rather than promoting axon regeneration, to restore neural function in neonates after SCI.

The hidden messengers: cancer associated fibroblasts-derived exosomal miRNAs as key regulators of cancer malignancy

Cancer-associated fibroblasts (CAFs), a class of stromal cells in the tumor microenvironment (TME), play a key role in controlling cancer cell invasion and metastasis, immune evasion, angiogenesis, and resistance to chemotherapy. CAFs mediate their activities by secreting soluble chemicals, releasing exosomes, and altering the extracellular matrix (ECM). Exosomes contain various biomolecules, such as nucleic acids, lipids, and proteins. microRNA (miRNA), a 22-26 nucleotide non-coding RNA, can regulate the cellular transcription processes. Studies have shown that miRNA-loaded exosomes secreted by CAFs engage in various regulatory communication networks with other TME constituents. This study focused on the roles of CAF-derived exosomal miRNAs in generating cancer malignant characteristics, including immune modulation, tumor growth, migration and invasion, epithelial-mesenchymal transition (EMT), and treatment resistance. This study thoroughly examines miRNA's dual regulatory roles in promoting and suppressing cancer. Thus, changes in the CAF-derived exosomal miRNAs can be used as biomarkers for the diagnosis and prognosis of patients, and their specificity can be used to develop newer therapies. This review also discusses the pressing problems that require immediate attention, aiming to inspire researchers to explore more novel avenues in this field.

Dysregulation of deubiquitination in breast cancer

Breast cancer (BC) is a highly frequent malignant tumor that poses a serious threat to women's health and has different molecular subtypes, histological subtypes, and biological features, which act by activating oncogenic factors and suppressing cancer inhibitors. The ubiquitin-proteasome system (UPS) is the main process contributing to protein degradation, and deubiquitinases (DUBs) are reverse enzymes that counteract this process. There is growing evidence that dysregulation of DUBs is involved in the occurrence of BC. Herein, we review recent research findings in BC-associated DUBs, describe their nature, classification, and functions, and discuss the potential mechanisms of DUB-related dysregulation in BC. Furthermore, we present the successful treatment of malignant cancer with DUB inhibitors, as well as analyzing the status of targeting aberrant DUBs in BC.

Effects of laparoscopic sleeve gastrectomy on nonalcoholic fatty liver disease and TGF-β signaling pathway

Nonalcoholic fatty liver disease (NAFLD) develops as a result of unhealthy lifestyle but improves with laparoscopic sleeve gastrectomy (LSG). The transforming growth factor (TGF)-β signaling pathway reportedly contributes to liver fibrosis, mainly in animal experiments. The aim of the present study was to evaluate changes in serum proteins before and after LSG by proteomic analysis and to investigate their association with NAFLD. This study enrolled 36 severely obese patients who underwent LSG at our hospital from January 2020 to April 2022. As a pilot study, proteomic analysis was conducted on six patients using serum collected before and at 6 months after LSG, and significantly fluctuating proteins were extracted. Subsequently, verification by enzyme-linked immunosorbent assay (ELISA) using collected serum was performed on the remaining 30 patients. The mean weight of enrolled patients was 118.5 kg. Proteomic analysis identified 1,912 proteins, many of which were related to the TGF-β signaling pathway. Among these proteins, we focused on five TGF-β-related proteins: asporin, EMILIN-1, platelet factor-4, serglycin, and thrombospondin-1. Verification by ELISA revealed that asporin (p = 0.006) and thrombospondin-1 (p = 0.043) levels significantly fluctuated before and after LSG. Univariate analysis with a linear regression model showed that aspartate aminotransferase (p = 0.045), asporin (p = 0.011), and thrombospondin-1 (p = 0.022) levels were significantly associated with postoperative liver fibrosis. On multivariate analysis, asporin was an independent prognostic factor for postoperative liver fibrosis (95% confidence interval: 0.114-1.291, p = 0.002). TGF-β-related proteins dramatically fluctuated before and after LSG and were correlated with NAFLD pathogenesis. Asporin may be a useful prognostic marker of liver fibrosis in NAFLD after LSG.

Cancer-associated fibroblast spatial heterogeneity and EMILIN1 expression in the tumor microenvironment modulate TGF-β activity and CD8+ T-cell infiltration in breast cancer

Rationale: The tumor microenvironment (TME) and its multifaceted interactions with cancer cells are major targets for cancer treatment. Single-cell technologies have brought major insights into the TME, but the resulting complexity often precludes conclusions on function. Methods: We combined single-cell RNA sequencing and spatial transcriptomic data to explore the relationship between different cancer-associated fibroblast (CAF) populations and immune cell exclusion in breast tumors. The significance of the findings was then evaluated in a cohort of tumors (N=75) from breast cancer patients using immunohistochemistry analysis. Results: Our data show for the first time the degree of spatial organization of different CAF populations in breast cancer. We found that IL-iCAFs, Detox-iCAFs, and IFNγ-iCAFs tended to cluster together, while Wound-myCAFs, TGFβ-myCAFs, and ECM-myCAFs formed another group that overlapped with elevated TGF-β signaling. Differential gene expression analysis of areas with CD8+ T-cell infiltration/exclusion within the TGF-β signaling-rich zones identified elastin microfibrillar interface protein 1 (EMILIN1) as a top modulated gene. EMILIN1, a TGF-β inhibitor, was upregulated in IFNγ-iCAFs directly modulating TGFβ immunosuppressive function. Histological analysis of 75 breast cancer samples confirmed that high EMILIN1 expression in the tumor margins was related to high CD8+ T-cell infiltration, consistent with our spatial gene expression analysis. High EMILIN1 expression was also associated with better prognosis of patients with breast cancer, underscoring its functional significance for the recruitment of cytotoxic T cells into the tumor area. Conclusion: Our data show that correlating TGF-β signaling to a CAF subpopulation is not enough because proteins with TGF-β-modulating activity originating from other CAF subpopulations can alter its activity. Therefore, therapeutic targeting should remain focused on biological processes rather than on specific CAF subtypes.

Tumor polo-like kinase 4 protein expression reflects lymphovascular invasion, higher Federation of Gynecology and Obstetrics stage, and shortened survival in endometrial cancer patients who undergo surgical resection

BACKGROUND

Polo-like kinase 4 (PLK4) serves as a marker for tumor features and poor outcomes in cancers. This study aimed to explore the associations of tumor PLK4 protein expression with tumor characteristics and survival in endometrial cancer (EC) patients who underwent surgical resection.

METHODS

This study included 142 EC patients who underwent surgical resection. Tumor tissue samples were obtained for tumor PLK4 protein expression detection via immunohistochemistry (IHC).

RESULTS

Among EC patients, 26.1% had a PLK4 IHC score of 0, 24.6% had a score of 1-3, 27.5% had a score of 4-6, and 21.8% had a score of 7-12. Tumor PLK4 protein expression positively associated with lymphovascular invasion (P = 0.008) and Federation of Gynecology and Obstetrics (FIGO) stage (P = 0.005). Disease-free survival (DFS) was not different between patients with tumor PLK4 IHC scores > 0 and ≤ 0 (P = 0.154) but was reduced in patients with scores > 3 vs. ≤ 3 (P = 0.009) and > 6 vs. ≤ 6 (P < 0.001). Similarly, overall survival (OS) was not different between patients with scores > 0 and ≤ 0 (P = 0.322) but was shorter in patients with scores > 3 vs. ≤ 3 (P = 0.011) and > 6 vs. ≤ 6 (P = 0.006). After adjustment, a tumor PLK4 IHC score > 6 (vs. ≤ 6) (hazard ratio (HR): 3.156, P = 0.008) or > 3 (vs. ≤ 3) (HR: 3.918, P = 0.026) was independently associated with shortened DFS and OS.

CONCLUSION

A tumor PLK4 IHC score > 6 or > 3 associates with shortened DFS and OS in EC patients who undergo surgical resection.

Periodontal ligament-associated protein-1 promotes osteoclastogenesis in mice by modulating TGF-β1/Smad1 pathway

BACKGROUND

Periodontal ligament-associated protein-1 (PLAP-1), an important target molecule of osteoarthritis research, may affect alveolar bone resorption. The aim of our study was to comprehensively and systematically detect the effect of PLAP-1 on alveolar bone resorption and the underlying mechanism in PLAP-1 knockout mouse models.

METHODS

We used a PLAP-1 knockout (C57BL/6N-Plap-1-/- ) mouse model to investigate the effect of PLAP-1 on osteoclast differentiation and the underlying mechanism by adding Porphyromonas gingivalis lipopolysaccharide to stimulate bone marrow-derived macrophages. The effect of PLAP-1 on alveolar bone resorption and the underlying mechanism were studied using a ligature periodontitis model, with microcomputed tomography imaging, immunochemistry, and immunofluorescence.

RESULTS

The in vitro analysis results demonstrated that PLAP-1 knockout significantly inhibited osteoclast differentiation under both normal and inflammatory conditions. Bioinformatic analysis, immunofluorescence, and co-immunoprecipitation showed colocalization and interaction between PLAP-1 and transforming growth factor beta 1 (TGF-β1). The phosphorylation of Smad1 was reduced in the PLAP-1 knockout cells compared with that in the cells from wild-type mice. The in vivo analysis results demonstrated that PLAP-1 knockout decreased bone resorption and the levels of osteoclast differentiation markers in experimental periodontitis compared with those in wild-type mice. Immunofluorescence staining confirmed colocalization of PLAP-1 and TGF-β1 in the experimental periodontitis model. The phosphorylation level of Smad1 was significantly reduced in PLAP-1 knockout mice compared with that in wild-type mice.

CONCLUSIONS

This study revealed that the knockout of PLAP-1 inhibits osteoclast differentiation and decreases alveolar bone resorption through the TGF-β1/Smad1 signaling pathway, which could serve as an innovative target for the prevention and treatment of periodontitis.

ASPORIN: A root of the matter in tumors and their host environment

Asporin (ASPN) has been identified as one of the members of the class I small leucine-rich proteoglycans (SLRPs) family in the extracellular matrix (ECM). It is involved in classic ensigns of cancers such as self-dependent growth, resistance to growth inhibitors, restricting apoptosis, cancer metastasis, and bone-related disorders. ASPN is different from other members of SLRPs, such as decorin (DCN) and biglycan (BGN), in a way that it contains a distinctive length of aspartate (D) residues in the amino (N) -terminal region. These D-repeats residues possess germline polymorphisms and are identified to be linked with cancer progression and osteoarthritis (OA). The polyaspartate stretch in the N-terminal region of the protein and its resemblance to DCN are the reasons it is called asporin. In this review, we comprehensively summarized and updated the dual role of ASPN in various malignancies, its structure in mice and humans, variants, mutations, cancer-associated signalings and functions, the relationship between ASPN and cancer-epithelial, stromal fibroblast crosstalk, immune cells and immunosuppression in cancer and other diseases. In cancer and other bone-related diseases, ASPN is identified to be regulating various signaling pathways such as TGFβ, Wnt/β-catenin, notch, hedgehog, EGFR, HER2, and CD44-mediated Rac1. These pathways promote cancer cell invasion, proliferation, and migration by mediating the epithelial-to-mesenchymal transition (EMT) process. Finally, we discussed mouse models mimicking ASPN in vivo function in cancers and the probability of therapeutic targeting of ASPN in cancer cells, fibrosis, and other bone-related diseases.

Characterization of vestibular schwannoma tissues using liquid chromatography-tandem mass spectrometry analysis of specific peptide fragments separated by in-sample tryptic protein digestion followed by mathematical analysis

Vestibular schwannoma is the most common benign neoplasm of the cerebellopontine angle. Its first symptoms include hearing loss, tinnitus, and vestibular symptoms, followed by cerebellar and brainstem symptoms, along with palsy of the adjacent cranial nerves. However, the clinical picture has unpredictable dynamics and currently, there are no reliable predictors of tumor behavior. Hence, it is desirable to have a fast routine method for analysis of vestibular schwannoma tissues at the molecular level. The major objective of this study was to verify whether a technique using in-sample specific protein digestion with trypsin would have the potential to provide a proteomic characterization of these pathological tissues. The achieved results showed that the use of this approach with subsequent liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of released peptides allowed a fast identification of a considerable number of proteins in two differential parts of vestibular schwannoma tissue as well as in tissues of control healthy samples. Furthermore, mathematical analysis of MS data was able to discriminate between pathological vestibular schwannoma tissues and healthy tissues. Thus, in-sample protein digestion combined with LC-MS/MS separation and identification of released specific peptides followed by mathematical analysis appears to have the potential for routine characterization of vestibular schwannomas at the molecular level. Data are available via ProteomeXchange with identifier PXD045261.

Identification and validation of cancer-associated fibroblast-related subtypes and the prognosis model of biochemical recurrence in prostate cancer based on single-cell and bulk RNA sequencing

BACKGROUND

Cancer-associated fibroblasts (CAFs) are an essential component of the tumor immune microenvironment that are involved in extracellular matrix (ECM) remodeling. We aim to investigate the characteristics of CAFs in prostate cancer and develop a biochemical recurrence (BCR)-related CAF signature for predicting the prognosis of PCa patients.

METHODS

The bulk RNA-seq and relevant clinical information were obtained from the TCGA and GEO databases, respectively. The infiltration scores of CAFs in prostate cancer patients were calculated using the MCP counter and EPIC algorithms. The single-cell RNA sequencing (scRNA-seq) was downloaded from the GEO database. Subsequently, univariate Cox regression analysis was employed to identify prognostic genes associated with CAFs. We identified two subtypes (C1 and C2) of prostate cancer that were associated with CAFs via non-negative matrix factorization (NMF) clustering. In addition, the BCR-related CAF signatures were constructed using Lasso regression analysis. Finally, a nomogram model was established based on the risk score and clinical characteristics of the patients.

RESULTS

Initially, we found that patients with high CAF infiltration scores had shorter biochemical recurrence-free survival (BCRFS) times. Subsequently, CAFs in four pairs of tumors and paracancerous tissues were identified. We discovered 253 significantly differentially expressed genes, of which 13 had prognostic significance. Using NMF clustering, we divided PCa patients into C1 and C2 subgroups, with the C1 subgroup having a worse prognosis and substantially enriched cell cycle, homologous recombination, and mismatch repair pathways. Furthermore, a BCR-related CAFs signature was established. Multivariate COX regression analysis confirmed that the BCR-related CAFs signature was an independent prognostic factor for BCR in PCa. In addition, the nomogram was based on the clinical characteristics and risk scores of the patient and demonstrated high accuracy and reliability for predicting BCR. Lastly, our findings indicate that the risk score may be a useful tool for predicting PCa patients' sensitivity to immunotherapy and drug treatment.

CONCLUSION

NMF clustering based on CAF-related genes revealed distinct TME immune characteristics between groups. The BCR-related CAF signature accurately predicted prognosis and immunotherapy response in prostate cancer patients, offering a promising new approach to cancer treatment.

Low- and high-grade glioma endothelial cells differentially regulate tumor growth

Background

A key feature distinguishing high-grade glioma (HGG) from low-grade glioma (LGG) is the extensive neovascularization and endothelial hyperproliferation. Prior work has shown that tumor endothelial cells (TEC) from HGG are molecularly and functionally distinct from normal brain EC and secrete higher levels of pro-tumorigenic factors that promote glioma growth and progression. However, it remains unclear whether TEC from LGG also express pro-tumorigenic factors, and to what extent they functionally contribute to glioma growth.

Methods

Transcriptomic profiling was conducted on tumor endothelial cells (TEC) from grade II/III (LGG, IDH-mutant) and grade IV HGG (IDH-wildtype). Functional differences between LGG- and HGG-TEC were evaluated using growth assays, resistance to anti-angiogenic drugs and radiation therapy. Conditioned media and specific factors from LGG- and HGG-TEC were tested on patient-derived gliomasphere lines using growth assays in vitro and in co-transplantation studies in vivo in orthotopic xenograft models.

Results

LGG-TEC showed enrichment of extracellular matrix and cell cycle-related gene sets and sensitivity to anti-angiogenic therapy whereas HGG-TEC displayed an increase in immune response-related gene sets and anti-angiogenic resistance. LGG- and HGG-TEC displayed opposing effects on growth and proliferation of IDH-wildtype and mutant tumor cells. Asporin (ASPN), a small leucine rich proteoglycan enriched in LGG-TEC was identified as a growth suppressor of IDH-wildtype GBM by modulating TGFΒ1-GPM6A signaling.

Conclusions

Our findings indicate that TEC from LGG and HGG are molecularly and functionally heterogeneous and differentially regulate the growth of IDH-wildtype and mutant tumors.

Small leucine rich proteoglycans: Biology, function and their therapeutic potential in the ocular surface

Small leucine rich proteoglycans (SLRPs) are the largest family of proteoglycans, with 18 members that are subdivided into five classes. SLRPs are small in size and can be present in tissues as glycosylated and non-glycosylated proteins, and the most studied SLRPs include decorin, biglycan, lumican, keratocan and fibromodulin. SLRPs specifically bind to collagen fibrils, regulating collagen fibrillogenesis and the biomechanical properties of tissues, and are expressed at particularly high levels in fibrous tissues, such as the cornea. However, SLRPs are also very active components of the ECM, interacting with numerous growth factors, cytokines and cell surface receptors. Therefore, SLRPs regulate major cellular processes and have a central role in major fundamental biological processes, such as maintaining corneal homeostasis and transparency and regulating corneal wound healing. Over the years, mutations and/or altered expression of SLRPs have been associated with various corneal diseases, such as congenital stromal corneal dystrophy and cornea plana. Recently, there has been great interest in harnessing the various functions of SLRPs for therapeutic purposes. In this comprehensive review, we describe the structural features and the related functions of SLRPs, and how these affect the therapeutic potential of SLRPs, with special emphasis on the use of SLRPs for treating ocular surface pathologies.

Cancer-associated fibroblasts and its derived exosomes: a new perspective for reshaping the tumor microenvironment

Cancer-associated fibroblasts (CAFs) are the most abundant stromal cells within the tumor microenvironment (TME). They extensively communicate with the other cells. Exosome-packed bioactive molecules derived from CAFs can reshape the TME by interacting with other cells and the extracellular matrix, which adds a new perspective for their clinical application in tumor targeted therapy. An in-depth understanding of the biological characteristics of CAF-derived exosomes (CDEs) is critical for depicting the detailed landscape of the TME and developing tailored therapeutic strategies for cancer treatment. In this review, we have summarized the functional roles of CAFs in the TME, particularly focusing on the extensive communication mediated by CDEs that contain biological molecules such as miRNAs, proteins, metabolites, and other components. In addition, we have also highlighted the prospects for diagnostic and therapeutic applications based on CDEs, which could guide the future development of exosome-targeted anti-tumor drugs.

Fibroblasts in cancer: Unity in heterogeneity

Tumor cells do not exist in isolation in vivo, and carcinogenesis depends on the surrounding tumor microenvironment (TME), composed of a myriad of cell types and biophysical and biochemical components. Fibroblasts are integral in maintaining tissue homeostasis. However, even before a tumor develops, pro-tumorigenic fibroblasts in close proximity can provide the fertile 'soil' to the cancer 'seed' and are known as cancer-associated fibroblasts (CAFs). In response to intrinsic and extrinsic stressors, CAFs reorganize the TME enabling metastasis, therapeutic resistance, dormancy and reactivation by secreting cellular and acellular factors. In this review, we summarize the recent discoveries on CAF-mediated cancer progression with a particular focus on fibroblast heterogeneity and plasticity.

Identification and characterization of bone/cartilage-associated signatures in common fibrotic skin diseases

Background: Fibrotic skin diseases are characterized by excessive accumulation of the extracellular matrix (ECM) and activation of fibroblasts, leading to a global healthcare burden. However, effective treatments of fibrotic skin diseases remain limited, and their pathological mechanisms require further investigation. This study aims to investigate the common biomarkers and therapeutic targets in two major fibrotic skin diseases, namely, keloid and systemic sclerosis (SSc), by bioinformatics analysis.

Methods: The keloid (GSE92566) and SSc (GSE95065) datasets were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified, followed by functional enrichment analysis using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). We then constructed a protein–protein interaction (PPI) network for the identification of hub genes. We explored the possibility of further functional enrichment analysis of hub genes on the Metascape, GeneMANIA, and TissueNexus platforms. Transcription factor (TF)–hub gene and miRNA–hub gene networks were established using NetworkAnalyst. We fixed GSE90051 and GSE76855 as the external validation datasets. Student’s t-test and receiver operating characteristic (ROC) curve were used for candidate hub gene validation. Hub gene expression was assessed in vitro by quantitative real-time PCR.

Results: A total of 157 overlapping DEGs (ODEGs) were retrieved from the GSE92566 and GSE95065 datasets, and five hub genes (COL11A1, COL5A2, ASPN, COL10A1, and COMP) were identified and validated. Functional studies revealed that hub genes were predominantly enriched in bone/cartilage-related and collagen-related processes. FOXC1 and miR-335-5p were predicted to be master regulators at both transcriptional and post‐transcriptional levels.

Conclusion: COL11A1, COL5A2, ASPN, COL10A1, and COMP may help understand the pathological mechanism of the major fibrotic skin diseases; moreover, FOXC1 and miR-355-5p could build a regulatory network in keloid and SSc.

Fibroblasts as Turned Agents in Cancer Progression

Differentiated epithelial cells reside in the homeostatic microenvironment of the native organ stroma. The stroma supports their normal function, their G0 differentiated state, and their expansion/contraction through the various stages of the life cycle and physiologic functions of the host. When malignant transformation begins, the microenvironment tries to suppress and eliminate the transformed cells, while cancer cells, in turn, try to resist these suppressive efforts. The tumor microenvironment encompasses a large variety of cell types recruited by the tumor to perform different functions, among which fibroblasts are the most abundant. The dynamics of the mutual relationship change as the sides undertake an epic battle for control of the other. In the process, the cancer "wounds" the microenvironment through a variety of mechanisms and attracts distant mesenchymal stem cells to change their function from one attempting to suppress the cancer, to one that supports its growth, survival, and metastasis. Analogous reciprocal interactions occur as well between disseminated cancer cells and the metastatic microenvironment, where the microenvironment attempts to eliminate cancer cells or suppress their proliferation. However, the altered microenvironmental cells acquire novel characteristics that support malignant progression. Investigations have attempted to use these traits as targets of novel therapeutic approaches.

Unusual Suspects: Bone and Cartilage ECM Proteins as Carcinoma Facilitators

The extracellular matrix (ECM) is the complex three-dimensional network of fibrous proteins and proteoglycans that constitutes an essential part of every tissue to provide support for normal tissue homeostasis. Tissue specificity of the ECM in its topology and structure supports unique biochemical and mechanical properties of each organ. Cancers, like normal tissues, require the ECM to maintain multiple processes governing tumor development, progression and spread. A large body of experimental and clinical evidence has now accumulated to demonstrate essential roles of numerous ECM components in all cancer types. Latest findings also suggest that multiple tumor types express, and use to their advantage, atypical ECM components that are not found in the cancer tissue of origin. However, the understanding of cancer-specific expression patterns of these ECM proteins and their exact roles in selected tumor types is still sketchy. In this review, we summarize the latest data on the aberrant expression of bone and cartilage ECM proteins in epithelial cancers and their specific functions in the pathogenesis of carcinomas and discuss future directions in exploring the utility of this selective group of ECM components as future drug targets.

Determinants of DNMT2/TRDMT1 preference for substrates tRNA and DNA during the evolution

RNA methyltransferase DNMT2/TRDMT1 is the most conserved member of the DNMT family from bacteria to plants and mammals. In previous studies, we found some determinants for tRNA recognition of DNMT2/TRDMT1, but the preference mechanism of this enzyme for substrates tRNA and DNA remains to be explored. In the present study, CFT-containing target recognition domain (TRD) and target recognition extension domain (TRED) in DNMT2/TRDMT1 play a crucial role in the substrate DNA and RNA selection during the evolution. Moreover, the classical substrate tRNA for DNMT2/TRDMT1 had a characteristic sequence CUXXCAC in the anticodon loop. Position 35 was occupied by U, making cytosine-38 (C38) twist into the loop, whereas C, G or A was located at position 35, keeping the C38-flipping state. Hence, the substrate preference could be modulated by the easily flipped state of target cytosine in tRNA, as well as TRD and TRED. Additionally, DNMT2/TRDMT1 cancer mutant activity was collectively mediated by five enzymatic characteristics, which might impact gene expressions. Importantly, G155C, G155V and G155S mutations reduced enzymatic activities and showed significant associations with diseases using seven prediction methods. Altogether, these findings will assist in illustrating the substrate preference mechanism of DNMT2/TRDMT1 and provide a promising therapeutic strategy for cancer.

Relationship between asporin and extracellular matrix behavior: A literature review

Asporin (ASPN), as a member of the small leucine-rich repeat proteoglycan family, is a type of protein that is found in the extracellular matrix. Collagen deposition or transformation is involved in a variety of pathological processes. ASPN is identified in cancerous tissue, pathological cardiac tissue, articular cartilage, keloid, and fibrotic lung tissue, and it has a role in the development of cancer, cardiovascular, bone and joint, keloid, and pulmonary fibrosis by interfering with collagen metabolism. This review article summarizes the data on ASPN expressions in mouse and human and highlights that overexpress of ASPN might play a role in a variety of diseases. Although our knowledge of ASPN is currently limited, these instances may help us better understand how it interacts with diseases.

Proteoglycans Determine the Dynamic Landscape of EMT and Cancer Cell Stemness

Proteoglycans (PGs) are pivotal components of extracellular matrices, involved in a variety of processes such as migration, invasion, morphogenesis, differentiation, drug resistance, and epithelial-to-mesenchymal transition (EMT). Cellular plasticity is a crucial intermediate phenotypic state acquired by cancer cells, which can modulate EMT and the generation of cancer stem cells (CSCs). PGs affect cell plasticity, stemness, and EMT, altering the cellular shape and functions. PGs control these functions, either by direct activation of signaling cascades, acting as co-receptors, or through regulation of the availability of biological compounds such as growth factors and cytokines. Differential expression of microRNAs is also associated with the expression of PGs and their interplay is implicated in the fine tuning of cancer cell phenotype and potential. This review summarizes the involvement of PGs in the regulation of EMT and stemness of cancer cells and highlights the molecular mechanisms.

Identification of nanoparticle-mediated siRNA-ASPN as a key gene target in the treatment of keloids

Background: Keloid, also known as connective tissue hyperplasia, is a benign proliferative disorder with a global distribution. The available therapeutic interventions are steroid injections, surgical removal of keloids, radiotherapy, compression therapy, the application of cryosurgery, and many other methods.

Objectives: Existing treatments or approaches for keloids may lead to similar or even larger lesions at the site of keloid excision, leading to a high recurrence rate. Therefore, this study aims at identifying a new gene-based therapy for the treatment of keloids.

Methods: An ASPN-siRNA/nanoparticle combination (si-ASPN) and a negative siRNA/nanoparticle complex (NC) was developed on the basis of bioinformatics studies and used in vitro and in vivo experiments.

Results: The results showed a strong correlation between the development of keloids and high expression of ASPN protein. With the expression of ASPN protein greatly reduced in keloid fibroblasts and nude mice allografts after treatment with si-ASPN, the collagen and fibroblasts were also uniform, thinner, parallel and regular.

Conclusion: All the above experimental results suggest that keloid and ASPN are closely related and both fibroblast growth and metabolism of keloid are inhibited after silencing ASPN. Therefore, ASPN-siRNA delivered via nanoparticles can serve as a novel intervention therapy for the treatment of keloids.

TGF-β at the crossroads of multiple prognosis in breast cancer, and beyond

Transforming growth factor β (TGF-β), a pluripotent cytokine and a multifunctional growth factor has a crucial role in varied biological mechanisms like invasion, migration, epithelial-mesenchymal transition, apoptosis, wound healing, and immunosuppression. Moreover, it also has an imperative role both in normal mammary gland development as well as breast carcinogenesis. TGF-β has shown to have a paradoxical role in breast carcinogenesis, by transitioning from a growth inhibitor to a growth promoter with the disease advancement. The inter-communication and crosstalk of TGF-β with different signaling pathways has strengthened the likelihood to explore it as a comprehensive biomarker. In the last two decades, TGF-β has been studied extensively and has been found to be a promising biomarker for early detection, disease monitoring, treatment selection, and tumor progression making it beneficial for disease management. In this review, we focus on the signaling pathways and biological activities of the TGF-β family in breast cancer pathogenesis and its role as a circulatory and independent biomarker for breast cancer progression and metastasis. Moreover, this review highlights TGF-β as a drug target, and the underlying mechanisms through which it is involved in tumorigenesis that will aid in the development of varied therapies targeting the different stages of breast cancer.

Adipose tissue-to-breast cancer crosstalk: Comprehensive insights

The review focuses on mechanistic evidence for the link between obesity and breast cancer. According to the IARC study, there is sufficient evidence that obesity is closely related to a variety of cancers. Among them, breast cancer is particularly disturbed by adipose tissue due to the unique histological structure of the breast. The review introduces the relationship between obesity and breast cancer from two aspects, including factors that promote tumorigenesis or metastasis. We summarize alterations in adipokines and metabolic pathways that contribute to breast cancer development. Breast cancer metastasis is closely related to obesity-induced pro-inflammatory microenvironment, adipose stem cells, and miRNAs. Based on the mechanism by which obesity causes breast cancer, we list possible therapeutic directions, including reducing the risk of breast cancer and inhibiting the progression of breast cancer. We also discussed the risk of autologous breast remodeling and fat transplantation. Finally, the causes of the obesity paradox and the function of enhancing immunity are discussed. Evaluating the balance between obesity-induced inflammation and enhanced immunity warrants further study.

Asporin Interacts With HER2 to Promote Thyroid Cancer Metastasis via the MAPK/EMT Signaling Pathway

Approximately 85% of histological subtypes of thyroid cancer are papillary thyroid cancer (PTC), and the morbidity and mortality of PTC patients rapidly increased due to lymph node metastases or distant metastasis. Therefore, it needs to distill an enhanced understanding of the pathogenesis of PTC patients with lymph node metastases or distant metastasis. We employed the TMT-based quantitative proteomics approach to identify and analyze differentially expressed proteins in PTC with different degrees of lymph node metastases. Compared with paired normal tissues, asporin is overexpressed in PTC-N0, PTC-N1a, and PTC-N1b tumorous tissues via proteomics, western blotting, and immunohistochemistry assays. Functionally, asporin is mainly expressed in the extracellular matrix, cell membrane, and cytoplasm of PTC tumorous tissues, and promotes thyroid cancer cell proliferation, migration, and invasion. Mechanistically, asporin, interacting with HER2, co-localizes HER2 on the cell membrane and cytoplasm, and the asporin/HER2/SRC/EGFR axis upregulate the expression of EMT-activating transcription factors through the MAPK signaling pathway. Clinically, asporin can be regarded as a serological biomarker to identify PTC patients with or without lymph node metastasis, and high expression of asporin in PTC tumorous tissues is a risk factor for poor prognosis.

Fibrous stroma: Driver and passenger in cancer development

Cumulative evidence shows that fibrogenic stroma and stiff extracellular matrix (ECM) not only result from tumor growth but also play pivotal roles in cellular transformation and tumor initiation. This emerging concept may largely account for the increased cancer risk associated with environmental fibrogenic agents, such as asbestos and silica, and with chronic conditions that are fibrogenic, such as obesity and diabetes. It may also contribute to poor outcomes in patients treated with certain chemotherapeutics that can promote fibrosis, such as bleomycin and methotrexate. Although the mechanistic details of this phenomenon are still being unraveled, we provide an overview of the experimental evidence linking fibrogenic stroma and tumor initiation. In this Review, we will summarize the causes and consequences of fibrous stroma and how this stromal cue is transmitted to the nuclei of parenchymal cells through a physical continuum from the ECM to chromatin, as well as ECM-dependent biochemical signaling that contributes to cellular transformation.

Antimicrobial production by perifollicular dermal preadipocytes is essential to the pathophysiology of acne

Innate immune defense against deep tissue infection by Staphylococcus aureus is orchestrated by fibroblasts that become antimicrobial when triggered to differentiate into adipocytes. However, the role of this process in noninfectious human diseases is unknown. To investigate the potential role of adipogenesis by dermal fibroblasts in acne, a disorder triggered by Cutibacterium acnes, single-cell RNA sequencing was performed on human acne lesions and mouse skin challenged by C. acnes. A transcriptome consistent with adipogenesis was observed within specific fibroblast subsets from human acne and mouse skin lesions infected with C. acnes. Perifollicular dermal preadipocytes in human acne and mouse skin lesions showed colocalization of PREF1, an early marker of adipogenesis, and cathelicidin (Camp), an antimicrobial peptide. This capacity of C. acnes to specifically trigger production of cathelicidin in preadipocytes was dependent on TLR2. Treatment of wild-type mice with retinoic acid (RA) suppressed the capacity of C. acnes to form acne-like lesions, inhibited adipogenesis, and enhanced cathelicidin expression in preadipocytes, but lesions were unresponsive in Camp^-/- mice, despite the anti-adipogenic action of RA. Analysis of inflamed skin of acne patients after retinoid treatment also showed enhanced induction of cathelicidin, a previously unknown beneficial effect of retinoids in difficult-to-treat acne. Overall, these data provide evidence that adipogenic fibroblasts are a critical component of the pathogenesis of acne and represent a potential target for therapy.

Crosstalk of tumor stromal cells orchestrates invasion and spreading of gastric cancer

Tumors contain various stromal cells that support cancer progression. Some types of cancer, such as scirrhous gastric cancer, are characterized by large areas of fibrosis accompanied by cancer-associated fibroblasts (CAFs). Asporin (ASPN) is a small leucine-rich proteoglycan highly expressed in CAFs of various tumors. ASPN accelerates CAF migration and invasion, resulting in CAF-led cancer cell invasion. In addition, ASPN further upregulated the expression of genes specific to a characteristic subgroup of fibroblasts in tumors. These cells were preferentially located at the tumor periphery and could be generated by a unique mechanism involving the CAF-mediated education of normal fibroblasts (CEFs). In this review, we at first describe recent findings regarding the function of ASPN in the tumor microenvironment, as well as the mechanism involved in the generation of CEFs. CAFs are derived from heterogeneous origins besides resident normal fibroblasts. Among them, CAFs derived from mesothelial cells (mesothelial cell-derived CAF [MC-CAFs]) play pivotal roles in peritoneal carcinomatosis. We observed that MC-CAFs on the surfaces of organs also participate in tumor formation by infiltrating into the parenchyma, promoting local invasion by gastric cancers. This review also highlights the potential functions of macrophages in the formation of MC-CAFs in gastric cancers, by transfer the contents of cancer cell-derived extracellular vesicles.

Fibroblast-derived prolargin is a tumor suppressor in hepatocellular carcinoma

Cancer-associated fibroblasts (CAF) are important constituents of the tumor microenvironment (TME) and are major drivers of tumorigenesis. Yet, therapies aiming at eliminating CAF have failed to cure patients. This setback has raised questions regarding whether CAF exclusively favour cancer progression, or if they may also assume tumor-suppressor functions. In the present study, we used proteomics and single cell RNA-sequencing analysis to examine the CAF landscape in hepatocellular carcinoma (HCC). We thereby unveil three major CAF populations in HCC, one of which specifically expressing the prolargin protein. This CAF subpopulation (further termed as CAF_Port) shared a strong transcriptomic signature with portal liver fibroblasts. We further show that CAF_Port deposit prolargin in the TME and that its levels are lower in tumors as compared to the peritumoral region. Mechanistically, aggressive cancer cells degraded prolargin using matrix metalloprotease activity. Survival analysis of 188 patients revealed that high prolargin protein levels correlate with good patient outcome (HR = 0.37; p = 0.01). In vivo, co-injection of cancer cells with fibroblasts silenced for prolargin, led to faster tumor development (5-fold; p = 0.01), mainly due to stronger angiogenesis. Using protein-protein interaction study and structural modelling, we further demonstrate that prolargin binds and inhibits the activity of several pro-agiogenic proteins, including hepatocyte and fibroblast growth factors. In conclusion, prolargin is angiogenesis modulator and CAF-derived tumor suppressor in HCC. Stabilizing prolargin levels in the CAF_Port subpopulation may revert their tumor-antagonizing properties, warranting exploration in further pre-clinical studies.

Asporin Promotes TGF-β-induced Lung Myofibroblast Differentiation by Facilitating Rab11-dependent Recycling of TβRI

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive fibrotic lung disease with high mortality and morbidity. Asporin (ASPN), a member of the small leucine-rich proteoglycan (SLRP) family, plays crucial roles in tissue injury and regeneration. However, the precise pathophysiological role of ASPN and its molecular mechanisms in IPF remain unknown. We sought to investigate the role of ASPN during the development of pulmonary fibrosis and the therapeutic potential of targeting ASPN-related signaling pathways. In our study, three microarray datasets were downloaded from the Gene Expression Omnibus (GEO) database, and differentially expressed genes (DEGs) were screened out by bioinformatic analysis. Hub genes were selected from the protein-protein interaction network. ASPN was examined in lung tissues from pulmonary fibrosis mouse models and the role of ASPN in TGF-β/Smad signaling was determined by transfection with ASPN shRNA vectors in vitro. Biotinylation assays were conducted to measure plasma membrane TβRI and TβRI recycling after ASPN knockdown. The results showed ASPN expression was increased in the lungs of pulmonary fibrosis mouse models, and ASPN was primarily localized in α-SMA+ myofibroblasts. In vitro experiments proved that ASPN knockdown inhibited TGF-β/Smad signaling and myofibroblast differentiation by regulating the stability of TβRI. Further molecular mechanisms revealed that ASPN knockdown inhibited TGF-β/Smad signaling by suppressing recycling of TβRI to the cell surface in a Rab11-dependent manner and facilitated lysosome-mediated degradation of TβRI. In conclusion, our findings provide important evidence for the use of ASPN as a novel pharmacological target for treating pulmonary fibrosis.

Breast Cancer CAFs: Spectrum of Phenotypes and Promising Targeting Avenues

Activationof the tumor-associated stroma to support tumor growth is a common feature observed in different cancer entities. This principle is exemplified by cancer-associated fibroblasts (CAFs), which are educated by the tumor to shape its development across all stages. CAFs can alter the extracellular matrix (ECM) and secrete a variety of different molecules. In that manner they have the capability to affect activation, survival, proliferation, and migration of other stromal cells and cancer cell themselves. Alteration of the ECM, desmoplasia, is a common feature of breast cancer, indicating a prominent role for CAFs in shaping tumor development in the mammary gland. In this review, we summarize the multiple roles CAFs play in mammary carcinoma. We discuss experimental and clinical strategies to interfere with CAFs function in breast cancer. Moreover, we highlight the issues arising from CAFs heterogeneity and the need for further research to identify CAFs subpopulation(s) that can be targeted to improve breast cancer therapy.

Roles of the Mesenchymal Stromal/Stem Cell Marker Meflin/Islr in Cancer Fibrosis

Fibroblasts synthesise the extracellular matrix (ECM) such as collagen and elastin, the excessive accumulation of which can lead to fibrosis and organ dysfunction under pathological conditions. Cancer-associated fibroblasts (CAFs) are major constituents of the tumour microenvironment (TME) that accompany the desmoplastic reaction responsible for anti-cancer treatment resistance. Thus, it is important to dissect the roles of CAFs in the TME to develop new therapeutic strategies for refractory cancers. Recent progress in the studies of CAF biology suggests that the functions of CAFs are complicated and that they are composed of functionally distinct populations, including cancer-promoting CAFs (pCAFs) and cancer-restraining CAFs (rCAFs). We recently identified a new cell surface marker for rCAFs in pancreatic and colon cancers, designated as Meflin (mesenchymal stromal cell- and fibroblast-expressing Linx paralogue)/Islr (immunoglobulin super family containing leucine-rich repeat). Based on the distribution of Meflin/Islr-positive cells, we also considered it a specific candidate marker for mesenchymal stroma/stem cells. Meflin/Islr-positive CAFs have been shown to suppress cancer progression by being involved in regulating collagen structures and BMP signalling in the TME. This review describes the function of Meflin/Islr in cancer fibrosis as well as in cardiac and lung fibrosis and its potential in the development of new cancer therapeutics.

Reciprocal interplay between asporin and decorin: Implications in gastric cancer prognosis

Effective patient prognosis necessitates identification of novel tumor promoting drivers of gastric cancer (GC) which contribute to worsened conditions by analysing TCGA-gastric adenocarcinoma dataset. Small leucine-rich proteoglycans, asporin (ASPN) and decorin (DCN), play overlapping roles in development and diseases; however, the mechanisms underlying their interplay remain elusive. Here, we investigated the complex interplay of asporin, decorin and their interaction with TGFβ in GC tumor and corresponding normal tissues. The mRNA levels, protein expressions and cellular localizations of ASPN and DCN were analyzed using real-time PCR, western blot and immunohistochemistry, respectively. The protein-protein interaction was predicted by in-silico interaction analysis and validated by co-immunoprecipitation assay. The correlations between ASPN and EMT proteins, VEGF and collagen were achieved using western blot analysis. A significant increase in expression of ASPN in tumor tissue vs. normal tissue was observed in both TCGA and our patient cohort. DCN, an effective inhibitor of the TGFβ pathway, was negatively correlated with stages of GC. Co-immunoprecipitation demonstrated that DCN binds with TGFβ, in normal gastric epithelium, whereas in GC, ASPN preferentially binds TGFβ. Possible activation of the canonical TGFβ pathway by phosphorylation of SMAD2 in tumor tissues suggests its role as an intracellular tumor promoter. Furthermore, tissues expressing ASPN showed unregulated EMT signalling. Our study uncovers ASPN as a GC-promoting gene and DCN as tumor suppressor, suggesting that ASPN can act as a prognostic marker in GC. For the first time, we describe the physical interaction of TGFβ with ASPN in GC and DCN with TGFβ in GC and normal gastric epithelium respectively. This study suggests that prevention of ASPN-TGFβ interaction or overexpression of DCN could serve as promising therapeutic strategies for GC patients.

Asporin inhibits collagen matrix-mediated intercellular mechanocommunications between fibroblasts during keloid progression

Keloids are fibrotic lesions that grow unceasingly and invasively and are driven by local mechanical stimuli. Unlike other fibrotic diseases and normal wound healing, keloids exhibit little transformation of dermal fibroblasts into α-SMA⁺ myofibroblasts. This study showed that asporin is the most strongly expressed gene in keloids and its gene-ontology terms relate strongly to ECM metabolism/organization. Experiments with human dermal cells (HDFs) showed that asporin overexpression/treatment abrogated the HDF ability to adopt a perpendicular orientation when subjected to stretching tension. It also induced calcification of the surrounding 3D collagen matrix. Asporin overexpression/treatment also prevented the HDFs from remodeling the surrounding 3D collagen matrix, leading to a disorganized network of thick, wavy collagen fibers that resembled keloid collagen architecture. This in turn impaired the ability of the HDFs to contract the collagen matrix. Asporin treatment also made the fibroblasts impervious to the fibrous collagen contraction of α-SMA⁺ myofibroblasts, which normally activates fibroblasts. Thus, by calcifying collagen, asporin prevents fibroblasts from linearly rearranging the surrounding collagen; this reduces both their mechanosensitivity and mechanosignaling to each other through the collagen network. This blocks fibroblast activation and differentiation into the mature myofibroblasts that efficiently remodel the extracellular matrix. Consequently, the fibroblasts remain immature, highly proliferative, and continue laying down abundant extracellular matrix, causing keloid growth and invasion. Notably, dermal injection of asporin-overexpressing HDFs into murine wounds recapitulated keloid collagen histopathological characteristics. Thus, disrupted interfibroblast mechanocommunication may promote keloid progression. Asporin may be a new diagnostic biomarker and therapeutic target for keloids.

Asporin represses gastric cancer apoptosis via activating LEF1-mediated gene transcription independent of β-catenin

Asporin (ASPN) presents in the tumor microenvironment and exhibits a cancer-promoting effect as a stroma protein. Even though ASPN has already been observed inside cancer cells, the functions of intracellular ASPN and its underlying mechanisms remain unknown. Here we reported that ASPN was upregulated in different stages of gastric cancer (GC), and associated with a poor prognosis. Moreover, we found that ASPN markedly inhibited GC cell apoptosis and promoted cell growth in vitro and in vivo. Further mechanism investigations revealed that ASPN directly binding to lymphoid enhancer-binding factor 1 (LEF1) and promoted LEF1-mediated gene transcription independent of β-catenin, the classic co-factor in the Wnt/LEF1 pathway. We also demonstrated that ASPN selectively facilitated LEF1 binding to and activating the promoters of PTGS2, IL6, and WISP1 to promote their transcription. The suppression of cell apoptosis by ASPN overexpression could be attenuated by LEF1 knockdown or 100 µM aspirin (PTGS2 inhibitor), and siASPN mediated apoptosis could be rescued by LEF1 ectopic expression or adding recombinant IL6. Therefore, we concluded that ASPN repressed GC cell apoptosis via activating LEF1-mediated gene transcription independent of β-catenin, which could serve as a potential prognostic biomarker in GC patients.

Asporin Expression on Stromal Cells and/or Cancer Cells Might Be A Useful Prognostic Marker in Patients with Diffuse-Type Gastric Cancer

BACKGROUND

Asporin (ASPN), a member of the proteoglycan family, has been shown to have a close correlation with cancer progression. It is not known whether ASPN is an oncogenic driver or a tumor suppressor in human gastric cancer. We sought herein to determine the relationship between ASPN expression and clinicopathological features of gastric cancer.

PATIENTS AND METHODS

A total of 296 gastric cancer patients (diffuse type, n = 144; intestinal type, n = 152) were enrolled. The ASPN expression level in each case was analyzed by immunohistochemistry.

RESULTS

ASPN was mainly found on stromal cells, especially on fibroblasts in tumor stroma, i.e., cancer-associated fibroblasts. The ASPN expression on either cancer cells or stromal cells was significantly high in macroscopic scirrhous-type tumors (p < 0.001) and histologically abundant stroma-type tumors (p < 0.001). Interestingly, a Kaplan-Meier survival curve of the 144 cases of diffuse-type gastric cancer revealed a significantly poorer prognosis in patients with ASPN-positive expression (p = 0.043; log rank) compared to those with ASPN-negative expression, but the prognoses were not significantly different in these subgroups of the 152 cases of intestinal-type gastric cancer. A multivariate analysis with respect to overall survival showed that ASPN expression on stromal cells and/or cancer cells was significantly correlated with overall survival in patients with diffuse-type gastric cancer (p = 0.041).

CONCLUSION

In gastric cancer, ASPN was expressed mainly on stromal cells and partially on cancer cells. ASPN expression on stromal cells and/or cancer cells might be a useful prognostic marker in patients with diffuse-type gastric cancer.

Frequency of Growth Differentiation Factor 5 rs143383 and asporin D-repeat polymorphisms in patients with hand and knee osteoarthritis in Kurdistan province, Iran

AIM

Osteoarthritis (OA) is the most common chronic joint disorder, resulting from the breakdown of joint cartilage. It occurs in the knees, hands, and hips, leading to pain, stiffness, inflammation, and swelling.

METHODS

In this study, 100 hand and knee OA patients, meeting the American College of Rheumatology criteria were included in the case group, and 100 healthy individuals were allocated to the control group. Blood samples were collected from the participants. After DNA extraction, genotyping was carried out for GDF5 rs143383 C/T polymorphism by allele-specific polymerase chain reaction (ASPCR) and for D-repeat alleles of asporin (ASPN) by conventional PCR assay.

RESULTS

The results showed that the frequency of the D14 allele of ASPN was significantly higher than other alleles in the case group (P = .0001). Also, the frequency of the D14 allele among women was significantly higher than in men (P = .004). Moreover, the frequency of the TT allele in GDF5 rs143383 C/T polymorphism was significantly higher than the CC and CT alleles in the case group, compared with the control group (P = .001). A significant difference was found between the TT allele and other alleles in female and male patients compared with the control group (P = .02).

CONCLUSIONS

The D14 allele of the ASPN gene and TT allele of the GDF5 gene (rs143383 + 104T/C) are associated with hand and knee OA in the Kurdish population, indicating that these alleles could be risk factors for OA, at least in our populations.

Intratumoral Fibrosis in Facilitating Renal Cancer Aggressiveness: Underlying Mechanisms and Promising Targets

Intratumoral fibrosis is a histologic manifestation of fibrotic tumor stroma. The interaction between cancer cells and fibrotic stroma is intricate and reciprocal, involving dysregulations from multiple biological processes. Different components of tumor stroma are implicated via distinct manners. In the kidney, intratumoral fibrosis is frequently observed in renal cell carcinoma (RCC). However, the underlying mechanisms remain largely unclear. In this review, we recapitulate evidence demonstrating how fibrotic stroma interacts with cancer cells and mechanisms shared between RCC tumorigenesis and renal fibrogenesis, providing promising targets for future studies.