Structural insights into the regulation of RyR1 by S100A1.

S100A1, a small homodimeric EF-hand Ca2+-binding protein (~21 kDa), plays an important regulatory role in Ca2+ signaling pathways involved in various biological functions including Ca2+ cycling and contractile performance in skeletal and cardiac myocytes. One key target of the S100A1 interactome is the ryanodine receptor (RyR), a huge homotetrameric Ca2+ release channel (~2.3 MDa) of the sarcoplasmic reticulum. Here, we report cryoelectron microscopy structures of S100A1 bound to RyR1, the skeletal muscle isoform, in absence and presence of Ca2+. Ca2+-free apo-S100A1 binds beneath the bridging solenoid (BSol) and forms contacts with the junctional solenoid and the shell-core linker of RyR1. Upon Ca2+-binding, S100A1 undergoes a conformational change resulting in the exposure of the hydrophobic pocket known to serve as a major interaction site of S100A1. Through interactions of the hydrophobic pocket with RyR1, Ca2+-bound S100A1 intrudes deeper into the RyR1 structure beneath BSol than the apo-form and induces sideways motions of the C-terminal BSol region toward the adjacent RyR1 protomer resulting in tighter interprotomer contacts. Interestingly, the second hydrophobic pocket of the S100A1-dimer is largely exposed at the hydrophilic surface making it prone to interactions with the local environment, suggesting that S100A1 could be involved in forming larger heterocomplexes of RyRs with other protein partners. Since S100A1 interactions stabilizing BSol are implicated in the regulation of RyR-mediated Ca2+ release, the characterization of the S100A1 binding site conserved between RyR isoforms may provide the structural basis for the development of therapeutic strategies regarding treatments of RyR-related disorders.

S100A11 promotes focal adhesion disassembly via myosin II-driven contractility and Piezo1-mediated Ca2+ entry.

S100A11 is a small Ca2+-activatable protein known to localize along stress fibers (SFs). Analyzing S100A11 localization in HeLa and U2OS cells further revealed S100A11 enrichment at focal adhesions (FAs). Strikingly, S100A11 levels at FAs increased sharply, yet transiently, just before FA disassembly. Elevating intracellular Ca2+ levels with ionomycin stimulated both S100A11 recruitment and subsequent FA disassembly. However, pre-incubation with the non-muscle myosin II (NMII) inhibitor blebbistatin or with an inhibitor of the stretch-activatable Ca2+ channel Piezo1 suppressed S100A11 recruitment, implicating S100A11 in an actomyosin-driven FA recruitment mechanism involving Piezo1-dependent Ca2+ influx. Applying external forces on peripheral FAs likewise recruited S100A11 to FAs even if NMII activity was inhibited, corroborating the mechanosensitive recruitment mechanism of S100A11. However, extracellular Ca2+ and Piezo1 function were indispensable, indicating that NMII contraction forces act upstream of Piezo1-mediated Ca2+ influx, in turn leading to S100A11 activation and FA recruitment. S100A11-knockout cells display enlarged FAs and had delayed FA disassembly during cell membrane retraction, consistent with impaired FA turnover in these cells. Our results thus demonstrate a novel function for S100A11 in promoting actomyosin contractility-driven FA disassembly.

S100A4 makes two appearances in mechanisms leading to fibrosis.

Non-muscle myosin 2 (NM2) is known to play an important role in myofibroblast transdifferentiation, a hallmark of fibrotic disorders. In a recent JBC article, Southern et al. demonstrate that endogenous S100A4, a calcium- and NM2-binding protein acts as a mechanoeffector in this process. Since extracellular S100A4 is also involved in fibrogenesis by triggering the inflammatory response, this small protein appears to contribute to fibrosis via at least two distinct mechanisms.

Repeated sprint training in hypoxia induces specific skeletal muscle adaptations through S100A protein signaling.

Athletes increasingly engage in repeated sprint training consisting in repeated short all-out efforts interspersed by short recoveries. When performed in hypoxia (RSH), it may lead to greater training effects than in normoxia (RSN); however, the underlying molecular mechanisms remain unclear. This study aimed at elucidating the effects of RSH on skeletal muscle metabolic adaptations as compared to RSN. Sixteen healthy young men performed nine repeated sprint training sessions in either normoxia (FIO2 = 0.209, RSN, n = 7) or normobaric hypoxia (FIO2 = 0.136, RSH, n = 9). Before and after the training period, exercise performance was assessed by using repeated sprint ability (RSA) and Wingate tests. Vastus lateralis muscle biopsies were performed to investigate muscle metabolic adaptations using proteomics combined with western blot analysis. Similar improvements were observed in RSA and Wingate tests in both RSN and RSH groups. At the muscle level, RSN and RSH reduced oxidative phosphorylation protein content but triggered an increase in mitochondrial biogenesis proteins. Proteomics showed an increase in several S100A family proteins in the RSH group, among which S100A13 most strongly. We confirmed a significant increase in S100A13 protein by western blot in RSH, which was associated with increased Akt phosphorylation and its downstream targets regulating protein synthesis. Altogether our data indicate that RSH may activate an S100A/Akt pathway to trigger specific adaptations as compared to RSN.

Dual and triple gene combinations of KRT5, KRT17, and S100A2 identify basal-like subtype of pancreatic ductal adenocarcinoma and correlate with survival outcome.

There is a significant difference in prognosis and response to chemotherapy between basal and classical subtypes of pancreatic ductal adenocarcinoma (PDAC). Further biomarkers are required to identify subtypes of PDAC. We selected candidate biomarkers via review articles. Correlations between these candidate markers and the PDAC molecular subtype gene sets were analyzed using bioinformatics, confirming the biomarkers for identifying classical and basal subtypes. Subsequently, 298 PDAC patients were included, and their tumor tissues were immunohistochemically stratified using these biomarkers. Survival data underwent analysis, including Cox proportional hazards modeling. Our results indicate that the pairwise and triple combinations of KRT5/KRT17/S100A2 exhibit a higher correlation coefficient with the basal-like subtype gene set, whereas the corresponding combinations of GATA6/HNF4A/TFF1 show a higher correlation with the classical subtype gene set. Whether analyzing unmatched or propensity-matched data, the overall survival time was significantly shorter for the basal subtype compared with the classical subtype (p < .001), with basal subtype patients also facing a higher risk of mortality (HR = 4.017, 95% CI 2.675-6.032, p < .001). In conclusion, the combined expression of KRT5, KRT17, and S100A2, in both pairwise and triple combinations, independently predicts shorter overall survival in PDAC patients and likely identifies the basal subtype. Similarly, the combined expression of GATA6, HNF4A, and TFF1, in the same manner, may indicate the classical subtype. In our study, the combined application of established biomarkers offers valuable insights for the prognostic evaluation of PDAC patients.

Early skin inflammatory biomarker is predictive of development and persistence of atopic dermatitis in infants.

BACKGROUND: The Short-Term Topical Application for Prevention of Atopic Dermatitis (STOP AD) study, a randomized, open-label trial evaluating the effect of short-term (from the first 4 postnatal days to age 8 weeks) skin barrier protection using Aveeno Dermexa Fast & Long-Lasting Balm (Johnson & Johnson, New Brunswick, NJ) in infants with a parent with allergic disease, demonstrated decreased cumulative incidence and decreased prevalence of atopic dermatitis (AD) at age 12 months. OBJECTIVE: In the STOP AD study, we aimed to identify skin biomarkers that are associated with risk of development of AD. METHODS: Skin swabs were collected from the cheek and antecubital fossa (AF) at baseline, age 8 weeks, and age 12 months from subsets of study participants from the intervention arm (n = 43 of 119) and control arm (n = 43 of 138) and were analyzed for specific cytokines (CCL27, CXCL2, human ß-defensin-1 [hBD-1], IL-18, IL-8, IL-1α, IL-1 receptor antagonist [IL-1RA], IL-1ß, S100A8/9, and IL-36γ) by ELISA. RESULTS: Higher titers of S100A8/9 at the AF at age 8 weeks in infants with the filaggrin wild-type genotype (FLGwt), but not in those with filaggrin loss-of-function mutation (FLGmut), predicted (1) development of AD in the first year of life (P = .033), (2) presence of AD at ages 6 or 12 months (P = .009 and .035, respectively), (3) persistence of AD between ages 6 and 12 months (P < .001), and (4) development of AD with the emollient intervention. CONCLUSION: Increased titers of S100A8/9 from skin swabs of the AF in high-risk infants at age 8 weeks with FLGwt were predictive of AD development in the first year of life and other AD features. These findings suggest that there are different molecular pathways leading to AD in individuals with FLGmut and in individuals with FLGwt. Early identification of infants who are likely to develop AD will allow more targeted interventions.

Modulation of prostaglandin transport activity of SLCO2A1 by annexin A2 and S100A10.

Solute carrier organic anion transporter family member 2A1 (SLCO2A1) is a prostaglandin (PG) transporter and serves as the osmosensitive ATP-permeable maxi-anion channel (Maxi-Cl). Since a heterotetrameric complex of annexin A2 (ANXA2) and S100A10 is obligatory for the channel activity, the present study aimed to determine if they regulate SLCO2A1-mediated PG transport. This study examined PGE2 uptake and ATP release in Anxa2 and/or S100a10 knockout (KO) murine breast C127 cells. Deletion of Slco2a1 decreased PGE2-d4 uptake by wild-type (WT) cells in an isotonic medium (290 mosmol/kgH2O). Decreased osmolarity (135 mosmol/kgH2O) stimulated ATP release but did not affect PGE2 uptake kinetics, showing Km (1,280 nM) and Vmax (10.38 pmol/15 s/mg protein) similar to those in isotonic medium (1,227 nM and 10.65 pmol/15 s/mg protein), respectively, in WT cells. Deletion of Anxa2 associated with loss of S100a10 diminished SLCO2A1-mediated ATP release and uncompetitively inhibited PGE2 uptake with lowered Km (376 nM) and Vmax (2.59 pmol/15 s/mg protein). Moreover, the immunoprecipitation assay confirmed the physical interaction of ANXA2 with SLCO2A1 in WT cells. Enforcement of ANXA2 expression to Anxa2 KO cells partially restored PGE2 uptake and increased Km (744.3 nM) and Vmax (9.07 pmol/15 s/mg protein), whereas the uptake clearance (Vmax/Km) did not change much regardless of ANXA2 expression. These results suggest that an ANXA2/S100A10 complex modulates PG transport activity but osmolality has little effect on it; therefore, the bound form of SLCO2A1, which functions as a PG transporter and Maxi-Cl, may exist regardless of changes in the cell volume.NEW & NOTEWORTHY A previous study indicated that the ANXA2/S100A10 complex represents the regulatory component of SLCO2A1-mediated Maxi-Cl channel activity. The present study showed that apparent PGE2 uptake by C127 cells was osmoinsensitive and uncompetitively inhibited by loss of ANXA2 expression, demonstrating that ANXA2 is a regulatory factor of SLCO2A1-mediated PG transport activity.

Resistance to gemcitabine is mediated by the circ_0036627/miR-145/S100A16 axis in pancreatic cancer.

The development of gemcitabine (GEM) resistance severely limits the treatment efficacy in pancreatic cancer (PC) and increasing evidence highlights the vital roles of circular RNAs (circRNAs) in the tumorigenesis, progression and drug resistance of PC. However, the circRNAs underlying GEM resistance development of PC remains to be clarified. The current research aims to unveil the roles of circ_0036627 in dictating the aggressiveness and GEM sensitivity in PC. We reported the increased expression of circ_0036627 in PC tissues and PC cell lines. Elevated circ_0036627 expression level was correlated with advanced tumour grade and poor overall survival in PC patients. Functional assays and in vivo experiments demonstrated that circ_0036627 overexpression was required for the proliferation, migration invasion and GEM resistance in PC cells. circ_0036627 knockdown suppressed tumour development in vivo. The molecular analysis further showed that circ_0036627 increased S100A16 expression by sponging microRNA-145 (miR-145), a tumour-suppressive miRNA that could significantly attenuate PC cell proliferation, migration, invasion and GEM resistance. Furthermore, our findings suggested that S100A16 acted as an oncogenic factor to promote aggressiveness and GEM resistance in PC cells. In conclusion, the current findings provide new mechanistic insights into PC aggressiveness and GEM resistance, suggesting the critical role of circ_0036627/miR-145/S100A16 axis in PC progression and drug resistance development and offering novel therapeutic targets for PC therapy.

S100A1's single cysteine is an indispensable redox switch for the protection against diastolic calcium waves in cardiomyocytes.

The EF-hand calcium (Ca2+) sensor protein S100A1 combines inotropic with antiarrhythmic potency in cardiomyocytes (CMs). Oxidative posttranslational modification (ox-PTM) of S100A1's conserved, single-cysteine residue (C85) via reactive nitrogen species (i.e., S-nitrosylation or S-glutathionylation) has been proposed to modulate conformational flexibility of intrinsically disordered sequence fragments and to increase the molecule's affinity toward Ca2+. Considering the unknown biological functional consequence, we aimed to determine the impact of the C85 moiety of S100A1 as a potential redox switch. We first uncovered that S100A1 is endogenously glutathionylated in the adult heart in vivo. To prevent glutathionylation of S100A1, we generated S100A1 variants that were unresponsive to ox-PTMs. Overexpression of wild-type (WT) and C85-deficient S100A1 protein variants in isolated CM demonstrated equal inotropic potency, as shown by equally augmented Ca2+ transient amplitudes under basal conditions and ß-adrenergic receptor (ßAR) stimulation. However, in contrast, ox-PTM defective S100A1 variants failed to protect against arrhythmogenic diastolic sarcoplasmic reticulum (SR) Ca2+ waves and ryanodine receptor 2 (RyR2) hypernitrosylation during ßAR stimulation. Despite diastolic performance failure, C85-deficient S100A1 protein variants exerted similar Ca2+-dependent interaction with the RyR2 than WT-S100A1. Dissecting S100A1's molecular structure-function relationship, our data indicate for the first time that the conserved C85 residue potentially acts as a redox switch that is indispensable for S100A1's antiarrhythmic but not its inotropic potency in CMs. We, therefore, propose a model where C85's ox-PTM determines S100A1's ability to beneficially control diastolic but not systolic RyR2 activity.NEW & NOTEWORTHY S100A1 is an emerging candidate for future gene-therapy treatment of human chronic heart failure. We aimed to study the significance of the conserved single-cysteine 85 (C85) residue in cardiomyocytes. We show that S100A1 is endogenously glutathionylated in the heart and demonstrate that this is dispensable to increase systolic Ca2+ transients, but indispensable for mediating S100A1's protection against sarcoplasmic reticulum (SR) Ca2+ waves, which was dependent on the ryanodine receptor 2 (RyR2) nitrosylation status.

An overview of S100 proteins and their functions in skin homeostasis, interface dermatitis conditions and other skin pathologies.

S100 proteins comprise a family of structurally related proteins that are calcium-sensitive. S100 proteins have been found to play various roles in regulation of cell apoptosis, cell proliferation and differentiation, cell migration and invasion, energy metabolism, calcium homeostasis, protein phosphorylation, anti-microbial activity and inflammation in a variety of cell types. While the specific function of many S100 proteins remains unknown, some of the S100 proteins serve as disease biomarkers as well as possible therapeutic targets in skin diseases. Interface dermatitis (ID) is a histopathological term that covers many different skin conditions including cutaneous lupus erythematosus, lichen planus, and dermatomyositis. These pathologies share similar histological features, which include basal cell vacuolization and lymphocytic infiltration at the dermal-epidermal junction. In this review, we summarize how the S100 protein family contributes to both homeostatic and inflammatory processes in the skin. We also highlight the role of S100 proteins in neuronal signalling, describing how this might contribute to neuroimmune interactions in ID and other skin pathologies. Last, we discuss what is known about the S100 family proteins as both biomarkers and potential treatment targets in specific pathologies.

Ultraviolet B irradiation increases the expression of cornulin and retepin in human skin xenotransplants.

Cornulin (CRNN) and repetin (RPTN) belong to the fused-type S100 protein family. Although these proteins have been reported to be expressed in the granular layer of the epidermis and have been suggested to be associated with barrier formation in the epidermis, their exact function remains unclear. This study examined the effects of ultraviolet B (UVB) irradiation on CRNN and RPTN expression in human skin xenotransplantation. The CRNN expression increased in the granular layer of UVB-irradiated skin 2 days after UVB irradiation compared to that in sham-irradiated skin. Interestingly, CRNN signals were observed not only in the cytoplasm, but also in the peripheral regions of granular keratinocytes. In contrast, RPTN was rarely expressed in sham-irradiated skin; however, RPTN signals were markedly increased in the granular layer of the UVB-irradiated skin. In addition, activation of ERK1/2 and STAT3 was observed in UVB-irradiated skin. Accordingly, the present study demonstrated that CRNN and RPTN are novel proteins whose expression can be increased by UVB irradiation. The activation of ERK1/2 and STAT3 may be associated with the regeneration of a UVB-damaged epidermis, and CRNN and RPTN may be induced to repair any dysfunction in the epidermal barrier during this regeneration process.

Comparative transcriptome analysis of acne vulgaris, rosacea, and hidradenitis suppurativa supports high-dose dietary zinc as a therapeutic agent.

Acne vulgaris, rosacea, and hidradenitis suppurativa are enduring inflammatory skin conditions that frequently manifest with akin clinical attributes, posing a considerable challenge for their distinctive diagnosis. While these conditions do exhibit certain resemblances, they also demonstrate distinct underlying pathophysiological mechanisms and treatment modalities. Delving into both the molecular parallels and disparities among these three disorders can yield invaluable insights for refined diagnostics, effective management, and targeted therapeutic interventions. In this report, we present a comparative analysis of transcriptomic data across these three diseases, elucidating differentially expressed genes and enriched pathways specific to each ailment, as well as those shared among them. Specifically, we identified multiple zinc-binding proteins (SERPINA1, S100A7, S100A8, S100A9 and KRT16) as consistently highly upregulated genes across all three diseases. Our hypothesis suggests that these proteins could bind and sequester zinc, potentially leading to localized zinc deficiency and heightened inflammation. We identified high-dose dietary zinc as a promising therapeutic approach and confirmed its effectiveness through validation in an acne mouse model.

Subungual melanoma with cartilaginous differentiation: Molecular insights.

Melanoma's rare capacity to undergo heterologous differentiation can create significant diagnostic challenges. The molecular mechanisms underlying this phenomenon are not well understood. We present an unusual case of subungual melanoma exhibiting extensive cartilaginous differentiation and provide insights into its molecular and cytogenomic features. Histopathologically, the tumor was predominantly composed of nodules of malignant cartilage in association with a smaller population of nested epithelioid to rhabdoid cells. Immunohistochemically, the tumor cells in both components were positive for S100, SOX10, and PRAME, and were negative for Melan-A and HMB-45. Molecular analysis by whole exome DNA sequence did not detect any pathogenic variants in genes commonly implicated in melanoma. Additional analysis by SNP chromosomal microarray revealed a complex genome characterized by numerous chromosomal losses and gains, including a homozygous deletion of the CDKN2A locus and a heterozygous deletion of the locus containing EXT2, a tumor suppressor implicated in hereditary multiple osteochondromas and secondary chondrosarcomas. This case underscores the importance of recognizing cartilaginous differentiation as a rare manifestation of melanoma, particularly at subungual sites, and suggests that at least some of these melanomas may be driven by non-canonical molecular pathways.

Single-cell and bulk RNA sequencing reveal heterogeneity and diagnostic markers in papillary thyroid carcinoma lymph-node metastasis.

PURPOSE: Papillary thyroid carcinoma (PTC) is characterized by lymph-node metastasis (LNM), which affects recurrence and prognosis. This study analyzed PTC LNM by single-cell RNA sequencing (scRNA-seq) data and bulk RNA sequencing (RNA-seq) to find diagnostic markers and therapeutic targets. METHODS: ScRNA-seq data were clustered and malignant cells were identified. Differentially expressed genes (DEGs) were identified in malignant cells of scRNA-seq and bulk RNA-seq, respectively. PTC LNM diagnostic model was constructed based on intersecting DEGs using glmnet package. Next, PTC samples from 66 patients were used to validate the two most significant genes in the diagnostic model, S100A2 and type 2 deiodinase (DIO2) by quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and immunohistochemical (IHC). Further, the inhibitory effect of DIO2 on PTC cells was verified by cell biology behavior, western blot, cell cycle analysis, 5-ethynyl-2'-deoxyuridine (EdU) assay, and xenograft tumors. RESULTS: Heterogeneity of PTC LNM was demonstrated by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis. A total of 19 differential genes were used to construct the diagnostic model. S100A2 and DIO2 differ significantly at the RNA (p < 0.01) and protein level in LNM patient tissues (p < 0.001). And differed in PTC tissues with different pathologic typing (p < 0.001). Further, EdU (p < 0.001) and cell biology behavior revealed that PTC cells overexpressed DIO2 had reduced proliferative capacity. Cell cycle proteins were reduced and cells are more likely to be stuck in G2/M phase (p < 0.001). CONCLUSIONS: This study explored the heterogeneity of PTC LNM using scRNA-seq. By combining with bulk RNA-seq data, diagnostic markers were explored and the model was established. Clinical diagnostic efficacy of S100A2 and DIO2 was validated and the treatment potential of DIO2 was discovered.

A Case of Superficial Papular Neuroma: A Rare Neural Neoplasm.

ABSTRACT: A case of 67-year-old male patient with superficial papular neuroma (SPN) on the occiput is reported. This is the second report of SPN and the first with clinical images. Histologically, in the superficial dermis and periadnexa, the specimen exhibits a nodule of bland spindle cells with an S-shaped and spindle nucleus, surrounded by eosinophilic collagen fibers and scattered mast cells, which forms focally peripheral nerve-like structures. Lichen simplex chronicus-like changes are observed. Immunostaining result revealed that the tumor cells are positive for S-100, neurofilament, collagen IV, and CD34 but negative for Melan A, epithelial membrane antigen, and glial fibrillary acidic protein. Histological differential diagnosis includes prurigo nodularis, neurotized nevus, benign peripheral nerve sheath tumor, such as neurofibroma or schwannoma, a type of neuroma, such as traumatic neuroma, mucosal neuroma, and palisaded encapsulated neuroma, or a type of neural hamartoma. A careful histological investigation will enable dermatopathologists to make a diagnosis of SPN.

Primary gallbladder melanoma: A systematic review of literature.

Primary gallbladder melanoma (PGM) is a rare malignancy with only sporadic cases reported in the English literature. We performed a systematic review of the cases published in the PubMed, Science Direct and Google Scholar databases with the aim of describing the reported clinicopathologic features of PGM. Thirty-six articles reporting on 39 patients were reviewed. There was a male predominance, with 23 (64 %) of 36 patients being males. The mean age at presentation was 55 ±16 years. Pain in the right upper quadrant was reported in 20/27 (74 %). The average size of the tumor was 3.5 × 1.9 × 1.4 cm. Gallbladder calculi were reported in 7/27 (26 %). A cholecystectomy was performed in 34/38 (89.5 %). Grossly, the tumor mostly (96.5 %) had polypoid appearances and on microscopic examination, the tumor were predominantly comprised of epithelioid cells 12/17 (70.6 %). Mitotic figures and prominent nucleoli were reportedly found in 8/8 (100 %) and 3/3 (100 %) respectively. Junctional melanocytic components were present in 13/21 (61.9 %). Tumor cells were reportedly immunoreactive for S-100 and HMB-45 in all tested cases. Metastasis were reported in 25/36 (69.4 %), with lymph nodes being the most common site (n = 8), followed by brain (n = 6) and liver (n = 4) for metastasis. At a mean follow-up period of 19 +/- 3 months, 16 (48.5 %) of the 33 patients with available survival data were alive and 17/33 (51.5 %) were dead of disease. There is a lack of unified criteria for the diagnosis of PGM, and future studies should aim to resolve this.

Primary schwannoma of the thyroid gland: analysis of case characteristics and review of the literature.

BACKGROUND: To improve the characteristics of primary thyroid schwannomas (PTS) and to provide reference basis for clinical diagnosis and treatment. METHODS: PubMed was searched for case reports of PTS up to December 2022 using the search terms "Thyroid nerve sheath tumor" or "Thyroid schwannoma" or "Thyroid Neurilemmoma", respectively. 34 cases were screened. RESULTS: PTS can occur at any age, nodules averaged 3.9 cm. The most common symptoms were voice change and dysphagia. Fine needle aspiration cytology showing spindle-shaped cells should be considered for schwannoma. Most cases underwent thyroid lobectomy or nodule removal with a good prognosis. Tissue types with both Antoni A and Antoni B features are common. Positive immunohistochemical staining for S-100 protein, CD34 and waveform proteins helped confirm the diagnosis. CONCLUSIONS: Positive immunohistochemistry for S-100 and wave proteins helps confirm the diagnosis. Preoperative diagnosis is challenging, but pathology and immunohistochemical staining are the gold standard for diagnosis. The first choice of treatment is surgical resection of the nodules, the prognosis is good.

Upregulation of psoriasin/S100A7 correlates with clinical severity in patients with oral lichen planus.

OBJECTIVES: The aim of this study was to: (1) investigate the expression patterns of antimicrobial peptides (AMPs), specifically psoriasin (S100A7) and calgranulin A and B (S100A8/A9), in patients with oral lichen planus (OLP) compared to healthy individuals; (2) evaluate the oral health-related quality of life (OHrQoL) in OLP patients versus healthy controls; (3) investigate the impact of clinical severity of OLP on OHrQoL; and (4) assess the influence of AMP expression on clinical severity and OHrQoL in OLP patients. MATERIALS AND METHODS: Oral mucosal biopsies (n = 38) were collected from healthy individuals (n = 17) and patients with OLP (n = 21). Levels of AMPs (S100A7, S100A8, S100A9) and pro-inflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor alpha (TNFα) were assessed by RT-qPCR. AMP protein localization was identified by indirect immunofluorescence analysis. OHrQoL was assessed using the OHIP-G14 questionnaire, and clinical severity was evaluated with the Oral Disease Severity Score (ODSS). Correlations between OLP manifestation, OHrQoL, and AMP expression were evaluated. RESULTS: (1) S100A7 (p < 0.001), IL-8 (p < 0.001), and TNFα (p < 0.001) mRNA levels were significantly upregulated in OLP tissue compared to healthy tissue, while S100A8 (p < 0.001) and S100A9 (p < 0.001) mRNA levels were downregulated. Immunofluorescence staining revealed an enhanced expression of S100A7 and decreased protein expression of S100A9 in OLP tissue. (2) OLP patients (9.58 ± 8.32) reported significantly higher OHIP-G14 scores compared to healthy individuals (0.67 ± 0.87; p < 0.001), particularly in the categories "physical pain" (p < 0.001) and "psychological discomfort" (p = 0.025). (3,4) Clinical severity (25.21 ± 9.77) of OLP correlated positively with OHrQoL (ρ = 0.497) and psoriasin expression (ρ = 0.402). CONCLUSIONS: This study demonstrated differential expression patterns of AMPs in OLP and highlighted the correlation between the clinical manifestation of OLP and OHrQoL. Further research approaches should address the role of psoriasin in the risk of malignant transformation of OLP. CLINICAL RELEVANCE: Psoriasin is a putative biomarker to monitor disease severity including malignant transformation of OLP lesions. OHIP-G14 scores can be useful to monitor OHrQoL in OLP patients.

Tetraspanin CD82 Correlates with and May Regulate S100A7 Expression in Oral Cancer.

Many metastatic cancers with poor prognoses correlate to downregulated CD82, but exceptions exist. Understanding the context of this correlation is essential to CD82 as a prognostic biomarker and therapeutic target. Oral squamous cell carcinoma (OSCC) constitutes over 90% of oral cancer. We aimed to uncover the function and mechanism of CD82 in OSCC. We investigated CD82 in human OSCC cell lines, tissues, and healthy controls using the CRISPR-Cas9 gene knockout, transcriptomics, proteomics, etc. CD82 expression is elevated in CAL 27 cells. Knockout CD82 altered over 300 genes and proteins and inhibited cell migration. Furthermore, CD82 expression correlates with S100 proteins in CAL 27, CD82KO, SCC-25, and S-G cells and some OSCC tissues. The 37-50 kDa CD82 protein in CAL 27 cells is upregulated, glycosylated, and truncated. CD82 correlates with S100 proteins and may regulate their expression and cell migration. The truncated CD82 explains the invasive metastasis and poor outcome of the CAL 27 donor. OSCC with upregulated truncated CD82 and S100A7 may represent a distinct subtype with a poor prognosis. Differing alternatives from wild-type CD82 may elucidate the contradictory functions and pave the way for CD82 as a prognostic biomarker and therapeutic target.

Knockdown of S100A2 inhibits the aggressiveness of endometrial cancer by activating STING pathway.

BACKGROUND: Endometrial cancer is a kind of gynaecological cancer. S100A2 is a newfound biomarker to diagnose endometrial cancer. This study was to investigate the role of S100A2 on regulating migration and invasion of endometrial cancer. METHODS: The mRNA and protein levels of S100A2 were obtained by quantitative real-time polymerase chain reaction, immunohistochemistry and western blot methods. Cell viability was measured by the Cell Counting Kit-8 assay. Cell migration and invasion were quantified using transwell assays. Western blot assay was conducted to quantify protein expressions of epithelial to mesenchymal transition-related proteins (N-cadherin and E-cadherin). Furthermore, in vivo tumour formation experiments were performed to evaluate the role of S100A2 on tumour xenografts. RESULTS: S100A2 was significantly up-regulated in endometrial cancer tissues. Knockdown of S100A2 inhibited cell viability, migration and invasion of endometrial cancer cells. Meanwhile, STING pathway was activated by the inhibited S100A2. STING inhibitor C-176 significantly reversed the effects of S100A2 knockdown on aggressive behaviours of endometrial cancer cells. Inhibition of S100A2 dramatically suppresses the tumour growth in vivo. CONCLUSIONS: S100A2 functions as an oncogene in endometrial cancer. Targeting S100A2 may be a promising therapeutic method to treat endometrial carcinoma.

This study was to investigate the role of S100A2 on regulating migration and invasion of endometrial cancer. S100A2 was significantly up-regulated in endometrial cancer tissues. Knockdown of S100A2 inhibited cell viability, migration and invasion of endometrial cancer cells. Meanwhile, STING pathway was activated by the inhibited S100A2. STING inhibitor C-176 significantly reversed the effects of S100A2 knockdown on aggressive behaviours of endometrial cancer cells. Inhibition of S100A2 dramatically suppresses the tumour growth in vivo. S100A2 functions as an oncogene in endometrial cancer. Targeting S100A2 may be a promising therapeutic method to treat endometrial carcinoma.