TWEAK/Fn14 Interaction Confers Aggressive Properties to Cutaneous Squamous Cell Carcinoma

The Oncogenic Role of TNFRSF12A in Colorectal Cancer and Pan-Cancer Bioinformatics Analysis

PURPOSE

Cancer has become a significant major public health concern, making the discovery of new cancer markers or therapeutic targets exceptionally important. Elevated expression of tumor necrosis factor receptor superfamily member 12A (TNFRSF12A) expression has been observed in certain types of cancer. This project aims to investigate the function of TNFRSF12A in tumors and the underlying mechanisms.

MATERIALS AND METHODS

Various websites were utilized for conducting the bioinformatics analysis. Tumor cell lines with stable knockdown or overexpression of TNFRSF12A were established for cell phenotyping experiments and subcutaneous tumorigenesis in BALB/c mice. RNA-seq was employed to investigate the mechanism of TNFRSF12A.

RESULTS

TNFRSF12A was upregulated in the majority of cancers and associated with a poor prognosis. Knockdown TNFRSF12A hindered the colorectal cancer progression, while overexpression facilitated malignancy both in vitro and in vivo. TNFRSF12A overexpression led to increased nuclear factor кB (NF-κB) signaling and significant upregulation of baculoviral IAP repeat containing 3 (BIRC3), a transcription target of the NF-κB member RELA, and it was experimentally confirmed to be a critical downstream factor of TNFRSF12A. Therefore, we speculated the existence of a TNFRSF12A/RELA/BIRC3 regulatory axis in colorectal cancer.

CONCLUSION

TNFRSF12A is upregulated in various cancer types and associated with a poor prognosis. In colorectal cancer, elevated TNFRSF12A expression promotes tumor growth, potentially through the TNFRSF12A/RELA/BIRC3 regulatory axis.

ATP2C1 knockdown induces abnormal expressions of cytoskeletal and tight junction proteins mimicking Hailey-Hailey disease

Background Hailey-Hailey disease (HHD) is a rare, autosomal dominant, hereditary skin disorder characterised by epidermal acantholysis. The HHD-associated gene ATPase calcium-transporting type 2C member 1 (ATP2C1) encodes the protein secretory pathway Ca2+ ATPase1 (SPCA1), playing a critical role in HHD pathogenesis. Aims We aimed to investigate the effect of ATP2C1 knockdown on keratinocytes that mimicked acantholysis in HHD. Methods Immunohistochemistry (IHC) was employed to evaluate the levels of cytoskeletal and tight junction proteins such as SPCA1, P-cofilin, F-actin, claudins, occludin, and zonula occludens 1 in the skin biopsies of patients with HHD. Subsequently, the expression of these proteins in cultured ATP2C1 knockdown keratinocytes was analysed using Western blotting and immunofluorescence. Furthermore, we assessed the proliferation, apoptosis, and intracellular Ca2+ concentrations in the ATP2C1-knocked keratinocytes. Results The results showed decreased levels of these proteins (SPCA1, P-cofilin, F-actin, claudins, occluding, and zonula occludens 1) in HHD skin lesions. Moreover, their levels decreased in human keratinocytes transfected with ATP2C1 short hairpin RNA, accompanied by morphological acantholysis. Furthermore, the proliferation and apoptosis of the keratinocytes, as well as intracellular calcium concentrations in these cells, were not affected. Limitations The limitations of this study are the absence of animal experiments and the failure to explore the relationship between skeletal and tight junction proteins. Conclusion The present study indicated that ATP2C1 inhibition led to abnormal levels of the cytoskeletal and tight junction proteins in the keratinocytes. Therefore, keratinocytes can mimic HHD-like acantholysis and serve as an in vitro model, helping develop treatment strategies against HHD.

Targeting TNFR2 for cancer immunotherapy: recent advances and future directions

Cancer is the leading cause of death worldwide, accounting for nearly 10 million deaths every year. Immune checkpoint blockade approaches have changed the therapeutic landscape for many tumor types. However, current immune checkpoint inhibitors PD-1 or CTLA-4 are far from satisfactory, due to high immune-related adverse event incident (up to 60%) and the inefficiency in cases of "cold" tumor microenvironment. TNFR2, a novel hopeful tumor immune target, was initially proposed in 2017. It not only promotes tumor cell proliferation, but also correlates with the suppressive function of Treg cells, implicating in the development of an immunosuppressive tumor microenvironment. In preclinical studies, TNFR2 antibody therapy has demonstrated efficacy alone or a potential synergistic effect when combined with classical PD-1/ CTLA-4 antibodies. The focus of this review is on the characteristics, functions, and recent advancements in TNFR2 therapy, providing a new direction for the next generation of anti-tumor alternative therapy.

Genetically predicted TWEAK mediates the association between lipidome and Keratinocyte Carcinomas

BACKGROUND

Reports suggest that lipid profiles may be linked to the likelihood of developing skin cancer, yet the exact causal relationship is still unknown.

OBJECTIVE

This study aimed to examine the connection between lipidome and skin cancers, as well as investigate any possible mediators.

METHODS

A two-sample Mendelian randomization (MR) analysis was conducted on 179 lipidomes and each skin cancer based on a genome-wide association study (GWAS), including melanoma, basal cell carcinoma (BCC), and squamous cell carcinoma (SCC). Then, Bayesian weighted MR was performed to verify the analysis results of two-sample MR. Moreover, a two-step MR was employed to investigate the impact of TNF-like weak inducer of apoptosis (TWEAK)-mediated lipidome on skin cancer rates.

RESULTS

MR analysis identified higher genetically predicted phosphatidylcholine (PC) (17:0_18:2) could reduce the risk of skin tumors, including BCC (OR = 0.9149, 95% CI: 0.8667-0.9658), SCC (OR = 0.9343, 95% CI: 0.9087-0.9606) and melanoma (OR = 0.9982, 95% CI: 0.9966-0.9997). The proportion of PC (17:0_18:2) predicted by TWEAK-mediated genetic prediction was 6.6 % in BCC and 7.6% in SCC. The causal relationship between PC (17:0_18:2) and melanoma was not mediated by TWEAK.

CONCLUSION

This study identified a negative causal relationship between PC (17:0_18:2) and keratinocyte carcinomas, a small part of which was mediated by TWEAK, and most of the remaining mediating factors are still unclear. Further research on other risk factors is needed in the future.

Mechanisms of norcantharidin against renal tubulointerstitial fibrosis

Renal tubulointerstitial fibrosis (RTIF) is a common feature and inevitable consequence of all progressive chronic kidney diseases, leading to end-stage renal failure regardless of the initial cause. Although research over the past few decades has greatly improved our understanding of the pathophysiology of RTIF, until now there has been no specific treatment available that can halt the progression of RTIF. Norcantharidin (NCTD) is a demethylated analogue of cantharidin, a natural compound isolated from 1500 species of medicinal insect, the blister beetle (Mylabris phalerata Pallas), traditionally used for medicinal purposes. Many studies have found that NCTD can attenuate RTIF and has the potential to be an anti-RTIF drug. This article reviews the recent progress of NCTD in the treatment of RTIF, with emphasis on the pharmacological mechanism of NCTD against RTIF.

Conjugation of the Fn14 Ligand to a SMAC Mimetic Selectively Suppresses Experimental Squamous Cell Carcinoma in Mice

The mimetic of SMAC induced cell death in cancers by depleting the inhibitor of apoptosis proteins. Recent studies showed that Fn14 is overexpressed in the cells of squamous cell carcinoma (SCC), providing a promising candidate target for selective antitumor therapy. In this study, we conjugated a small-molecule SMAC mimetic MV1 to the ligand of Fn14, TWEAK. Our results showed that TWEAK‒MV1 conjugate retained adequate binding specificity to Fn14-positive SCC cells in vitro and accumulated selectively in tumor tissue of cutaneous SCC xenografts mice after intraperitoneal administration. This conjugation compound exhibited remarkable effectiveness in suppressing tumor growth and extending overall survival without causing significant side effects in SCC xenograft mice. Moreover, TWEAK‒MV1 conjugate greatly enhanced both apoptotic and necroptotic cell death both in vitro and in vivo, accompanied by a cellular inhibitor of apoptosis proteins degradation as well as activation of receptor-interacting protein kinase. Taken together, our preclinical data suggested that the designed conjugation compound of TWEAK and MV1 might provide a potential therapeutic strategy for cutaneous SCC with improved antitumor efficacy and negligible toxicity.

TWEAK/Fn14 signaling may function as a reactive compensatory mechanism against extracellular matrix accumulation in keloid fibroblasts

Overabundance of the extracellular matrix resulting from hyperproliferation of keloid fibroblasts (KFs) and dysregulation of apoptosis represents the main pathophysiology underlying keloids. TWEAK is a weak apoptosis inducer, and it plays a critical role in pathological tissue remodeling via its receptor, Fn14. However, the role of TWEAK/Fn14 signaling in the pathogenesis of keloids has not been investigated. In this study, we confirmed the overexpression levels of TWEAK and Fn14 in clinical keloid tissue specimens and primary KFs. The extracellular matrix (ECM)-related genes were also evaluated between primary KFs and their normal counterparts to determine the factors leading to the formation or development of keloids. Unexpectedly, exogenous TWEAK significantly reduced the levels of collagen I and collagen III, as well as alpha-smooth muscle actin (α-SMA). Additionally, TWEAK promoted MMPs expression and apoptosis activity of KFs. Furthermore, we verified that the inhibitory effect of TWEAK on KFs is through down-regulation of Polo-like kinase 5, which modulates cell differentiation and apoptosis. The TWEAK-Fn14 axis seems to be a secondary, although less effective, compensatory mechanism to increase the catabolic functions of fibroblasts in an attempt to further decrease the accumulation of collagen. DATA AVAILABILITY: All data generated or analyzed during this study are included in this published article (and its Supporting Information files).

Targeting fibroblast growth factor (FGF)-inducible 14 (Fn14) for tumor therapy

Fibroblast growth factor-inducible 14 (Fn14) is a member of the tumor necrosis factor (TNF) receptor superfamily (TNFRSF) and is activated by its ligand TNF-like weak inducer of apoptosis (TWEAK). The latter occurs as a homotrimeric molecule in a soluble and a membrane-bound form. Soluble TWEAK (sTWEAK) activates the weakly inflammatory alternative NF-κB pathway and sensitizes for TNF-induced cell death while membrane TWEAK (memTWEAK) triggers additionally robust activation of the classical NF-κB pathway and various MAP kinase cascades. Fn14 expression is limited in adult organisms but becomes strongly induced in non-hematopoietic cells by a variety of growth factors, cytokines and physical stressors (e.g., hypoxia, irradiation). Since all these Fn14-inducing factors are frequently also present in the tumor microenvironment, Fn14 is regularly found to be expressed by non-hematopoietic cells of the tumor microenvironment and most solid tumor cells. In general, there are three possibilities how the tumor-Fn14 linkage could be taken into consideration for tumor therapy. First, by exploitation of the cancer associated expression of Fn14 to direct cytotoxic activities (antibody-dependent cell-mediated cytotoxicity (ADCC), cytotoxic payloads, CAR T-cells) to the tumor, second by blockade of potential protumoral activities of the TWEAK/Fn14 system, and third, by stimulation of Fn14 which not only triggers proinflammtory activities but also sensitizes cells for apoptotic and necroptotic cell death. Based on a brief description of the biology of the TWEAK/Fn14 system and Fn14 signaling, we discuss the features of the most relevant Fn14-targeting biologicals and review the preclinical data obtained with these reagents. In particular, we address problems and limitations which became evident in the preclinical studies with Fn14-targeting biologicals and debate possibilities how they could be overcome.

Airway basal cells show regionally distinct potential to undergo metaplastic differentiation

Basal cells are multipotent stem cells of a variety of organs, including the respiratory tract, where they are major components of the airway epithelium. However, it remains unclear how diverse basal cells are and how distinct subpopulations respond to airway challenges. Using single cell RNA-sequencing and functional approaches, we report a significant and previously underappreciated degree of heterogeneity in the basal cell pool, leading to identification of six subpopulations in the adult murine trachea. Among these, we found two major subpopulations, collectively comprising the most uncommitted of all the pools, but with distinct gene expression signatures. Notably, these occupy distinct ventral and dorsal tracheal niches and differ in their ability to self-renew and initiate a program of differentiation in response to environmental perturbations in primary cultures and in mouse injury models in vivo. We found that such heterogeneity is acquired prenatally, when the basal cell pool and local niches are still being established, and depends on the integrity of these niches, as supported by the altered basal cell phenotype of tracheal cartilage-deficient mouse mutants. Finally, we show that features that distinguish these progenitor subpopulations in murine airways are conserved in humans. Together, the data provide novel insights into the origin and impact of basal cell heterogeneity on the establishment of regionally distinct responses of the airway epithelium during injury-repair and in disease conditions.

UHRF1 Knockdown Attenuates Cell Growth, Migration, and Invasion in Cutaneous Squamous Cell Carcinoma

Ubiquitin like with PHD and ring finger domains 1 (UHRF1) contributes to the progression of many cancers. Here, we firstly observed UHRF1 was elevated in cutaneous squamous cell carcinoma (cSCC) and related to the differentiation stages. Knockdown of UHRF1 in A431 and Scl-1 attenuated cell proliferation, migration, and invasion, leading to G2/M cell cycle arrest and apoptosis. Through a mouse xenograft model, we found UHRF1 deficiency ameliorated tumor growth. These results may be associated with destruction of multiple signal pathways. In summary, our results suggest UHRF1 is involved in the pathogenesis of cSCC and may be a therapeutic target.

Norcantharidin protects against renal interstitial fibrosis by suppressing TWEAK-mediated Smad3 phosphorylation

AIMS

This study investigated the role and mechanism of action of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in the pathogenesis of renal interstitial fibrosis (RIF), and its involvement in the anti-RIF effect of norcantharidin (NCTD).

MAIN METHODS

Mice with unilateral ureteral obstruction and BUMPT mouse proximal tubular cells exposed to transforming growth factor (TGF)-β1 were used as in vivo and in vitro models of RIF, respectively. NCTD was administered to mice by intraperitoneal injection (0.075 mg kg^-1·day^-1). Hematoxylin-eosin and Masson's trichrome staining were performed to assess pathologic changes in the kidney. Immunohistochemistry, western blotting, and real-time PCR were performed to evaluate the expression of TWEAK and the fibrotic factors fibronectin (FN) and collagen type I (Col-I). The role of TWEAK in RIF and in the anti-RIF effect of NCTD was evaluated by TWEAK overexpression and neutralization with a specific antibody, and specific inhibitor of Mothers against decapentaplegic homolog (Smad)3 (SIS3) was used to examine the involvement of TGF-β1/Smad3 signaling.

KEY FINDINGS

TWEAK was mainly expressed in renal tubules in mice; the level was markedly elevated in both in vivo and in vitro RIF models. TWEAK overexpression in BUMPT cells increased the levels of phosphorylated Smad3, FN, and Col-I, which were reduced by treatment with SIS3. NCTD suppressed FN and Col-I expression by blocking TWEAK-mediated Smad3 phosphorylation.

SIGNIFICANCE

Upregulation of TWEAK contributes to RIF by promoting Smad3 phosphorylation, while NCTD inhibits this process.

TWEAK Promotes the Proliferation of Squamous Cell Carcinoma Cells Through Activating cIAP1 Signals

Recent studies showed that tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) induces the proliferation of squamous cell carcinoma (SCC) cells. However, the precise mechanism underlying such effect of TWEAK remains unclear. This study was designed to elucidate the role of cellular inhibitor of apoptosis 1 (cIAP1) in TWEAK-induced proliferation of SCC cells. Human SCC cells (SCC-13, A431, and SCC-9) were cultured in vitro, receiving the stimulation of TWEAK or TNF-related apoptosis-inducing ligand (TRAIL). We found that TWEAK induced cytoplasmic cIAP1 importation and RIP1 ubiquitination in cells, followed by the activation of canonical nuclear factor kappa B signals. MV1, a cIAP1 inhibitor, abrogated TWEAK-induced proliferation of these cells. Moreover, the interaction between TWEAK and its receptor, fibroblast growth factor-inducible 14 (Fn14), enhanced the expression of TRAIL receptor types 3 and 4 (TRAIL-R3/4). Furthermore, the transfection of TRAIL-R3/4 siRNA abrogated the promotion effect of TWEAK on SCC-13 cell proliferation and cIAP1 expression. Therefore, TWEAK/Fn14 interaction promotes the proliferation of SCC cells through activating cIAP1 signals. Targeting the downstream cIAP1 signals might attenuate the effect of TWEAK on SCC cells.

Experimental atopic dermatitis is dependent on the TWEAK/Fn14 signaling pathway

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) acts through its receptor fibroblast growth factor inducible 14 (Fn14), and participates in skin inflammation. Both TWEAK and Fn14 are highly expressed in skin lesions of patients with atopic dermatitis. The purpose of this study was to further explore the effect of Fn14 inhibition on experimental atopic dermatitis. Experimental atopic dermatitis was induced in the wild-type and Fn14 knock-out BALB/c mice. The effect of TWEAK/Fn14 interaction on keratinocytes was studied in an in-vitro model of atopic dermatitis. Fn14 deficiency ameliorates skin lesions in the mice model, accompanied by less infiltration of inflammatory cells and lower local levels of proinflammatory cytokines, including TWEAK, TNF-α and interleukin (IL)-17. Fn14 deficiency also attenuates the up-regulation of TNFR1 in skin lesions of atopic dermatitis. Moreover, topical TWEAK exacerbates skin lesion in the wild-type but not in the Fn14 knock-out mice. In vitro, TWEAK enhances the expressions of IL-17, IL-18 and IFN-γ in keratinocytes under atopic dermatitis-like inflammation. These results suggest that Fn14 deficiency protects mice from experimental atopic dermatitis, involving the attenuation of inflammatory responses and keratinocyte apoptosis. In the context of atopic dermatitis-like inflammation, TWEAK modulates keratinocytes via a TNFR1-mediated pathway.

Tumor Necrosis Factor (TNF) Receptor Expression Determines Keratinocyte Fate upon Stimulation with TNF-Like Weak Inducer of Apoptosis

The interaction between tumor necrosis factor- (TNF-) like weak inducer of apoptosis (TWEAK) and fibroblast growth factor-inducible 14 (Fn14) regulates the fate of keratinocytes, depending on the relative expression of TNF receptor (TNFR) 1 or TNFR2. However, the precise mechanism underlying this TWEAK-mediated regulation remains unclear. The aim of this study was to provide comprehensive insight into the roles of Fn14, TNFR1/2, and other relevant molecules in the fate of keratinocytes. Further, we sought to elucidate the structural basis for the interaction of TWEAK and Fn14 in regulating cellular outcomes. Normal keratinocytes (mainly expressing TNFR1) and TNFR2-overexpressing keratinocytes were stimulated with TWEAK. Through immunoprecipitation and Western blotting of keratinocyte lysates, we elucidated the associations between Fn14, TNFR-associated factor 2 (TRAF2), cellular inhibitor of apoptosis protein 1 (cIAP1), and TNFR1/2 molecules. Additionally, we found that TRAF2 exhibited binding to Fn14, cIAP1, and TNFR1/2. Our data suggest that TWEAK induces apoptosis in normal keratinocytes and proliferation in TNFR2-overexpressing keratinocytes in a TNF-α-independent manner; however, inhibition of TRAF2 appears to reverse this effect. Interestingly, the interaction between TWEAK and Fn14 increased TNFR1-associated death domain protein and caspase-8 expression in normal keratinocytes and promoted cytoplasmic import of cIAP1 in TNFR2-overexpressing keratinocytes. In conclusion, we found that the Fn14-TRAF2-TNFR signaling axis mediates TWEAK's regulation of the fate of keratinocytes, possibly in a manner involving the TNF-α-independent TNFR signal transduction.

Tumor necrosis factor-like weak inducer of apoptosis expression in healthy oral mucosa, oral dysplasia and oral squamous cell carcinoma

Objective:

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) has been implicated in the pathogenesis of cancer, as it participates in the progression of internal malignancies. However, its role in the biology of squamous cell carcinoma (SCC) is uncertain. Studies regarding TWEAK in SCC have shown inconsistent results. We aimed to study the expression of TWEAK in healthy oral mucosa, oral dysplastic lesions and in oral SCC (OSCC).

Methods:

Immunohistochemistry for TWEAK was performed on one hundred oral mucosal tissues, healthy control (HC) (n = 20), oral dysplasia (OD) (n = 20) and OSCC (n = 60). Staining intensity, extent of staining (ES) and immunoreactive Score (IRS) were assessed for each sample. Kruskal–Wallis ANOVA, Mann–Whitney U, Chi-square and Spearman's rank correlation coefficient were applied.

Results:

TWEAK was expressed in 55% of HC, 90% of OD and in all cases of OSCC, with variable intensities. A significant difference in the ES and IRS of TWEAK was noted among the three groups. ES and IRS were highest in OSCC group. ES of TWEAK was significantly higher at invasive tumor front (ITF) than in the whole tumor, with a significant positive correlation. TWEAK expression showed a significant association with invasive front grading, pattern of invasion and surgical margins of OSCC.

Conclusions:

TWEAK may contribute to the progression of OSCC. It might also sustain altered differentiation, invasion and migration of tumor cells at ITF.