Loss of epidermal MCPIP1 is associated with aggressive squamous cell carcinoma

Eccrine poroma versus eccrine porocarcinoma: a comparative study of clinicopathological features

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare cutaneous neoplasm, commonly arising from its benign counterpart, eccrine poroma (EP), but potential unrevealed clinicopathological differences between them are not well understood.

OBJECTIVES

This study aimed to identify clinicopathological features of EP and EPC and describe the factors that may be associated with the malignant transformation of EP by comparing the two groups.

METHODS

A total of 37 cases of EP and 22 cases of EPC diagnosed between January 2017 and June 2023 were retrospectively reviewed, and the clinical and histopathological characteristics were compared using statistical methods.

RESULTS

Clinical and histopathologic data such as age, gender, site, clinical presentation, and histopathologic characteristics were collected. The EPC group was more common in older patients, with more cases located in exposed areas, and the patients with EPC had larger lesions with a higher incidence of ulceration. Histopathological features showed significant differences in tumor architecture, ulceration, squamous differentiation, spindle cell changes, central necrosis, and diffuse inflammatory infiltration between the two groups.

STUDY LIMITATIONS

This study has limitations due to a small number of cases with potential experimental bias.

CONCLUSION

The clinicopathological features of EP and EPC were compared in this study and the results may assist clinicians in diagnosis and management of these tumors by helping to identify potential factors associated with the malignant transformation of EP.

SUV39H1 epigenetically modulates the MCPIP1-AURKA signaling axis to enhance neuroblastoma tumorigenesis

Epigenetic regulation is a pivotal factor during neuroblastoma (NB) pathogenesis and investigations into cancer epigenetics are actively underway to identify novel therapeutic strategies for NB patients. SUV39H1, a member of the H3K9 methyltransferase family, contributing to tumorigenesis across multiple malignancies. However, its specific role in NB remains unexplored. In this study, we conducted a high-throughput screen utilizing a compound library containing 288 epigenetic drugs, leading to the identification of chaetocin as the most potent NB inhibitor by targeting SUV39H1. Genetic manipulation and therapeutic inhibition of SUV39H1 significantly impacted proliferation, migration, cell cycle phases, and apoptosis in NB cells. Concurrently, chaetocin demonstrated robust anti-tumor efficacy in vivo with tolerable toxicity. RNA-seq unveiled that SUV39H1 knockdown and inhibition down-regulated cell cycle pathways, impacting vital genes such as AURKA. Besides, MCPIP1 emerged as a novel tumor suppressor following SUV39H1 inhibition, which decreased AURKA expression in NB. In detail, SUV39H1 mediated the enrichment of H3K9me3 at the promoter region of MCPIP1, repressing the MCPIP1-mediated degradation of AURKA and facilitating the subsequent accumulation of AURKA, which revealed the oncogenic role of SUV39H1 via the SUV39H1-MCPIP1-AURKA signaling axis in NB. Therapeutic inhibition of SUV39H1 using chaetocin emerges as an effective and safe strategy for NB patients. Illustration of the oncogenic pathway regulated by SUV39H1 in NB.

MCPIP1 modulates the miRNA‒mRNA landscape in keratinocyte carcinomas

BACKGROUND

Monocyte Chemotactic Protein 1-Induced Protein 1 (MCPIP1, also called Regnase-1) is a negative modulator of inflammation with tumor-suppressive properties. Mice with keratinocyte-specific deletion of the Zc3h12a gene, encoding MCPIP1, (Mcpip1eKO mice) are more susceptible to the development of epidermal papillomas initiated by 7,12-dimethylbenz[a]-anthracene (DMBA) and promoted by 2-O-tetradecanoylphorbol-13-acetate (TPA).

METHODS

The aim of this study was to investigate the MCPIP1 RNase-dependent microRNA (miRNA)‒mRNA regulatory network in chemically induced squamous cell carcinoma (SCC)-like skin papillomas. Next-generation sequencing (NGS) coupled with bioinformatic analysis was used to shortlist the MCPIP1-dependent changes in protein-coding genes and miRNAs. The expression levels of the selected miRNAs were analyzed by quantitative PCR in human keratinocytes with MCPIP1 silencing. Functional studies were performed in human keratinocytes transfected with appropriate miRNA mimics. The DIANA-microT-CDS algorithm and DIANA-TarBase v7 database were used to predict potential target genes and identify the experimentally validated targets of differentially expressed (DE) miRNAs.

RESULTS

RNA sequencing (RNA-Seq) analysis of control and Mcpip1eKO DMBA/TPA-induced papillomas revealed transcriptome changes, with 2400 DE protein-coding genes and 33 DE miRNAs. The expression of miR-223-3p, miR-376c-3p, and miR-139-5p was confirmed to be dependent on MCPIP1 activity in both murine and human models. We showed that MCPIP1 directly regulates the expression of miR-376c-3p via direct cleavage of the corresponding precursor miRNA. The pro-proliferative activity of miR-223-3p, miR-376c-3p, and miR-139-5p was experimentally confirmed in SCC-like keratinocytes. Bioinformatic prediction of the mRNA targets of the DE-miRNAs revealed 416 genes as putative targets of the 18 upregulated miRNAs and 425 genes as putative targets of the 15 downregulated miRNAs. Further analyses revealed the murine interactions that are conserved in humans. Functional analysis indicated that during the development of cutaneous SCC, the most important pathways/processes mediated by the miRNA‒mRNA MCPIP1-dependent network are the regulation of inflammatory processes, epithelial cell proliferation, Wnt signaling, and miRNA transcription.

CONCLUSIONS

Loss of MCPIP1 modulates the expression profiles of 33 miRNAs in chemically induced Mcpip1eKO papillomas, and these changes directly affect the miRNA‒mRNA network and the modulation of pathways and processes related to carcinogenesis.

Keratinocyte and myeloid MCPIP1 have distinct roles in maintaining skin homeostasis

The skin is a complex organ, and the intricate network between keratinocytes and immune cells is critical for ensuring skin function. Monocyte chemotactic protein-1-induced protein 1 (MCPIP1) is a ribonuclease that functions as a key negative modulator of inflammation. We previously reported that conditional deletion of MCPIP1 in keratinocytes (Mcpip1EKO) impairs skin integrity in adult mice. A similar phenotype was observed following the depletion of MCPIP1 in the myeloid compartment (Mcpip1MKO). The aim of this study was to develop a keratinocyte and myeloid double-MCPIP1 knockout mouse model to clarify the specific roles of myeloid and epidermal MCPIP1 in skin biology. Histological analyses indicated that the skin morphology changed after depletion of MCPIP1 in cells of myeloid origin as well as in keratinocytes. The thicknesses of the epidermal and subcutaneous fat layers increased in the mice with a loss of epidermal MCPIP1, whereas the loss of myeloid MCPIP1 had the opposite effect. In addition, both types of mice showed opposite responses to stimulation with 12-O-tetradecanoylphorbol-13-acetate. Transcriptomic profiling of whole-skin lysates revealed some common target transcripts in all the knockout mice. Further analyses revealed that distinct pathways are modulated following the loss of epidermal or myeloid MCPIP1. The skin morphology and inflammatory phenotype of keratinocyte and myeloid double-MCPIP1 knockout mice resembled those of mice with only keratinocyte-specific knockout of MCPIP1. Overall, myeloid and epidermal MCPIP1 play important but distinct roles in the modulation of skin-related processes.

MCPIP1 Elicits a Therapeutic Effect on Cervical Cancer by Facilitating XIAP mRNA Decay via Its Endoribonuclease Activity

Cervical cancer is the fourth most common malignancy in women globally. Chemotherapies, targeted therapies, and immunotherapies in the treatment of cervical cancer are usually accompanied by effective and adverse effects. Therefore, finding other efficient and accurate molecular targets remains essential to improve the treatment benefits of cervical cancer patients. MCPIP1 (monocyte chemoattractant protein-induced protein 1) is a kind of endonuclease with a CCCH zinc finger domain and a PilT-N-terminal (PIN) domain, and its function in cervical cancer is unknown. We found that MCPIP1 inhibits cell proliferation and promotes cell apoptosis of cervical cancer. Additionally, MCPIP1 suppresses mRNA and protein expression of the apoptotic inhibitor XIAP by decreasing its mRNA stability. Mechanically, MCPIP1 binds to the XIAP mRNA via its CCCH zinc finger domain and degrades the XIAP mRNA via the endonuclease activity coming from its PIN domain. Our study clarifies that MCPIP1 promotes cervical cancer cell apoptosis by suppressing the expression of XIAP, thereby impeding cervical cancer progression. Moreover, targeted delivery of MCPIP1 with engineered Salmonella typhimurium leads to tumor growth retardation in the HeLa xenograft tumor model in mice. Therefore, our study may provide a theoretical basis for formulating clinical treatment strategies for cervical cancer.

MCPIP1 Inhibits Hepatic Stellate Cell Activation in Autocrine and Paracrine Manners, Preventing Liver Fibrosis

BACKGROUND & AIMS

Hepatic fibrosis is characterized by enhanced deposition of extracellular matrix (ECM), which results from the wound healing response to chronic, repeated injury of any etiology. Upon injury, hepatic stellate cells (HSCs) activate and secrete ECM proteins, forming scar tissue, which leads to liver dysfunction. Monocyte-chemoattractant protein-induced protein 1 (MCPIP1) possesses anti-inflammatory activity, and its overexpression reduces liver injury in septic mice. In addition, mice with liver-specific deletion of Zc3h12a develop features of primary biliary cholangitis. In this study, we investigated the role of MCPIP1 in liver fibrosis and HSC activation.

METHODS

We analyzed MCPIP1 levels in patients' fibrotic livers and hepatic cells isolated from fibrotic murine livers. In vitro experiments were conducted on primary HSCs, cholangiocytes, hepatocytes, and LX-2 cells with MCPIP1 overexpression or silencing.

RESULTS

MCPIP1 levels are induced in patients' fibrotic livers compared with their nonfibrotic counterparts. Murine models of fibrosis revealed that its level is increased in HSCs and hepatocytes. Moreover, hepatocytes with Mcpip1 deletion trigger HSC activation via the release of connective tissue growth factor. Overexpression of MCPIP1 in LX-2 cells inhibits their activation through the regulation of TGFB1 expression, and this phenotype is reversed upon MCPIP1 silencing.

CONCLUSIONS

We demonstrated that MCPIP1 is induced in human fibrotic livers and regulates the activation of HSCs in both autocrine and paracrine manners. Our results indicate that MCPIP1 could have a potential role in the development of liver fibrosis.

RNA Metabolism Governs Immune Function and Response

Inflammation is a complex process that protects our body from various insults such as infection, injury, and stress. Proper inflammation is beneficial to eliminate the insults and maintain organ homeostasis, however, it can become detrimental if uncontrolled. To tightly regulate inflammation, post-transcriptional mechanisms governing RNA metabolism play a crucial role in monitoring the expression of immune-related genes, such as tumor necrosis factor (TNF) and interleukin-6 (IL-6). These mechanisms involve the coordinated action of various RNA-binding proteins (RBPs), including the Regnase family, Roquin, and RNA methyltransferases, which are responsible for mRNA decay and/or translation regulation. The collaborative efforts of these RBPs are essential in preventing aberrant immune response activation and consequently safeguarding against inflammatory and autoimmune diseases. This review provides an overview of recent advancements in our understanding of post-transcriptional regulation within the immune system and explores the specific roles of individual RBPs in RNA metabolism and regulation.

Construction and validation of a prognostic model for tongue cancer based on three genes signature

Tongue squamous cell carcinoma (TSCC) has a poor prognosis and destructive characteristics. Reliable biomarkers are urgently required to predict disease outcomes and to guide TSCC treatment. This study aimed to develop a multigene signature and prognostic nomogram that can accurately predict the prognosis of patients with TSCC. We screened differentially expressed genes associated with TSCC using The Cancer Genome Atlas dataset. Based on this, we developed a new multi-mRNA gene signature using univariate Cox regression, Least Absolute Shrinkage and Selection Operator regression, and multivariate Cox regression. We used the concordance index to evaluate the accuracy of this new multigene model. Moreover, we performed receiver operating characteristic and Kaplan-Meier survival analyses to assess the predictive ability of the new multigene model. In addition, we created a prognostic nomogram incorporating clinical and pathological characteristics, with the aim of enhancing the adaptability of this model in practical clinical settings. We successfully developed a new prognostic model based on the expression levels of these 3 mRNAs that can be used to predict the prognosis of patients with TSCC. This prediction model includes 3 genes: KRT33B, CDKN2A, and CA9. In the validation set, the concordance index of this model was 0.851, and the area under the curve was 0.778 and 0.821 in the training and validation sets, respectively. Kaplan-Meier survival analysis showed that regardless of whether it was in the training or validation set, the prognosis of high-risk patients was significantly worse than that of low-risk patients (P < .001). Multivariate Cox regression analysis revealed that this model was an independent prognostic factor for patients with TSCC (P < .001). Our study suggests that this 3-gene signature model has a high level of accuracy and predictive ability, is closely related to the overall survival rate of patients with TSCC, and can independently predict the prognosis of TSCC patients with high accuracy and predictive ability.

N4BP1 regulates keratinocytes development and plays protective role in burn- and adhesive-related skin injury via MMP9

Extensive studies have demonstrated critical roles of Regnase-1 in skin inflammation; however the role of N4BP1, a member of Regnase-1 family, in skin is largely unexplored. Here, we found that N4BP1 was highly expressed in skin and its expression was further increased upon skin injury. Compared to wildtype mice, N4BP1 deficient mice showed severe skin injury upon tape-stripping and burns. Overexpression of N4BP1 in HaCaT cells caused more cuboidal with higher cell-to-cell packing, while reduced expression of N4BP1 made cells become more spindle shaped and loosely packed. Overexpression of N4BP1 promoted cell migration, while silence of N4BP1 reduced migration. N4BP1 deficient HaCaT cells were more sensitive to heats compared to control cells. RNA profiling in N4BP1 genetically modified cells demonstrated that N4BP1 broadly affects cellular behaviors such as epithelium development. RNA profiling, RT-PCR verification, WB analysis and RNA immunoprecipitation demonstrated that MMP9 was one of N4BP1 targets that significantly increased in N4BP1 deficient HaCaT cells and skin tissues. Collectively, our results demonstrate a protective role of N4BP1 in skin injury through broadly affecting cellular behaviors of keratinocytes. Furthermore, we identified MMP9 is a target of N4BP1 in keratinocytes. Our findings provide new insight to understand how N4BP1 protects skin under injury.

Keratinocyte Regnase-1, a Downregulator of Skin Inflammation, Contributes to Protection against Tumor Promotion by Limiting Cyclooxygenase-2 Expression

We previously showed that the ribonuclease Regnase-1 (Reg1) in keratinocytes plays a role in mitigating skin inflammation by downregulating proinflammatory cytokines. In this study, we explored whether Reg1 also has a protective role against skin carcinogenesis. The chemically induced two-stage carcinogenesis protocol revealed that epidermis-specific Reg1-deficient (Reg1-knockout [Reg1-cKO]) mice developed skin tumors with shorter latency and more multiplicity than control mice. In addition, repeated UVB irradiation readily provoked solar keratosis-like lesions in Reg1-cKO mice. Increased levels of cyclooxygenase 2, whose mRNA (Ptgs2) is reportedly a target of Reg1, have been known to be associated with the development of squamous cell carcinomas. Indeed, Ptgs2 mRNA levels were upregulated in the skin of Reg1-cKO mice after treatment with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate. The level of prostaglandin E2 was higher in 12-O-tetradecanoylphorbol-13-acetate‒treated Reg1-cKO mouse skin than in control mice skin. Moreover, in vivo inhibition of cyclooxygenase 2 attenuated the 12-O-tetradecanoylphorbol-13-acetate‒induced epidermal thickening in Reg1-cKO mice. Finally, REG1 knockdown in human squamous cell carcinomas lines enhanced PTGS2 mRNA levels after 12-O-tetradecanoylphorbol-13-acetate treatment. In conclusion, epidermal Reg1 plays a regulatory role not only in skin inflammation but also in tumor promotion through the downregulation of cyclooxygenase 2. Therefore, forced expression of Reg1 under inflammatory conditions may be relevant to preventing skin cancer.