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.

Repeated stress to the skin amplifies neutrophil infiltration in a keratin 17- and PKCα-dependent manner.

Neutrophils are the first immune cells to reach inflamed sites and contribute to the pathogenesis of chronic inflammatory skin diseases. Yet, little is known about the pattern of neutrophil infiltration in inflamed skin in vivo and the mechanisms mediating their recruitment. Here, we provide insight into the dynamics of neutrophil infiltration in skin in response to acute or repeated inflammatory stress, highlighting a novel keratinocyte- and keratin 17 (K17)-dependent mechanism that regulates neutrophil recruitment to inflamed skin. We used the phorbol ester TPA and UVB, alone or in combination, to induce sterile inflammation in mouse skin. A single TPA treatment results in a neutrophil influx in the dermis that peaks at 12 h and resolves within 24 h. A subsequent TPA treatment or a UVB challenge, when applied 24 h but not 48 h later, accelerates, amplifies, and prolongs neutrophil infiltration. This transient amplification response (TAR) is mediated by local signals in inflamed skin, can be recapitulated in ex vivo culture, and involves the K17-dependent sustainment of protein kinase Cα (PKCα) activity and release of chemoattractants by stressed keratinocytes. K17 binds RACK1, a scaffold protein essential for PKCα activity. The N-terminal head domain of K17 is crucial for its association with RACK1 and regulation of PKCα activity. Analysis of RNAseq data reveals a signature consistent with TAR and PKCα activation in inflammatory skin diseases. These findings uncover a novel, keratin-dependent mechanism that amplifies neutrophil recruitment in skin under stress, with direct implications for inflammatory skin disorders.

Keratin 17 and Collagen type 1 genes: Esophageal cancer molecular marker discovery and evaluation.

One hundred eighty pairs of tissues of esophageal squamous cell carcinoma (ESCC) were tested by the transcriptome sequencing in order to explore etiology factors. The chi-square test and correlation analysis demonstrated that the relative expression levels of keratin 17 (KRT17) and collagen type I α1 chain (COL1A1) were significantly higher in EC with diabetes. Expression of KRT17 was correlated with blood glucose (r = 0.204, p = 0.001) and tumor size (r = -0.177, p = 0.038) in patients. COL1A1 correlated with age (r = -0.170, p = 0.029) and blood glucose levels (r = 0.190, p = 0.015). Experimental results of qRT-PCR: KRT17 and COL1A1 genes were highly expressed in ESCC (p < 0.05). When the two genes were used as a combination test, the positive detection rate of EC was 90.6%, and the ROC curve had greater power. The KRT17 and COL1A1 genes had the potential to be biomarkers for the diagnosis of ESCC.

Over-expression of KRT17 and MDK genes at mRNA levels in urine-exfoliated cells is associated with early non-invasive diagnosis of non-muscle-invasive bladder cancer.

INTRODUCTION: Current diagnostic approaches for bladder cancer (BLCA) are often invasive or lack the required sensitivity and specificity. This underscores the need for an early non-invasive diagnostic test for BLCA. This work aimed to explore the potential of molecular markers in urine-exfoliated cells for the diagnosis of non-muscle-invasive bladder cancer (NMIBC). MATERIALS AND METHODS: Urine specimens (n = 140) were collected from NMIBC patients (n = 68) and control subjects (31 healthy volunteers and 41 non-cancer patients with common urological diseases [CUD]. Total RNA was extracted from the cells isolated from urine specimens. mRNA expression of selected genes: CDC20, KRT15, FOXM1, CXCR2, UPK1B, MDK, KRT20, and KRT17 was determined using RT-qPCR. The receiver operating characteristic (ROC) curve was then plotted to obtain the area under the curve (AUC), specificity, and sensitivity of the urinary mRNA markers. RESULTS: The expression of CDC20, MDK, UPK1B, FOXM1, KRT17, and KRT20 was up-regulated in samples obtained from low- and high-grade pathological grades of NMIBC compared to that measured in healthy subjects. Notably, MDK and KRT17 mRNA levels in the low- and high-grade cases were substantially higher than in normal and CUD groups. The AUC of the KRT17 and MDK combination in diagnosing NMIBC was 0.92, surpassing that of single genes. The sensitivity and specificity of the KRT17 and MDK combination were 74% and 94%, respectively. In diagnosing low-grade from healthy and CUD groups, analysis of the KRT17 and MDK combination yielded AUCs of 0.94 and 0.95, respectively, with sensitivities of 85% and 97%, and specificities of 93% and 85%. CONCLUSION: The findings of this study revealed that KRT17 and MDK together are potential urine-based biomarkers for early diagnosis of NMIBC.

Expression patterns of keratin family members during tooth development and the role of keratin 17 in cytodifferentiation of stratum intermedium and stellate reticulum.

Keratins are typical intermediate filament proteins of the epithelium that exhibit highly specific expression patterns related to the epithelial type and stage of cellular differentiation. They are important for cytoplasmic stability and epithelial integrity and are involved in various intracellular signaling pathways. Several keratins are associated with enamel formation. However, information on their expression patterns during tooth development remains lacking. In this study, we analyzed the spatiotemporal expression of keratin family members during tooth development using single-cell RNA-sequencing (scRNA-seq) and microarray analysis. scRNA-seq datasets from postnatal Day 1 mouse molars revealed that several keratins are highly expressed in the dental epithelium, indicating the involvement of keratin family members in cellular functions. Among various keratins, keratin 5 (Krt5), keratin 14 (Krt14), and keratin 17 (Krt17) are highly expressed in the tooth germ; KRT17 is specifically expressed in the stratum intermedium (SI) and stellate reticulum (SR). Depletion of Krt17 did not affect cell proliferation in the dental epithelial cell line SF2 but suppressed their differentiation ability. These results suggest that Krt17 is essential for SI cell differentiation. Furthermore, scRNA-seq results indicated that Krt5, Krt14, and Krt17 exhibited distinct expression patterns in ameloblast, SI, and SR cells. Our findings contribute to the elucidation of novel mechanisms underlying tooth development.

Keratin 17 modulates the immune topography of pancreatic cancer.

BACKGROUND: The immune microenvironment impacts tumor growth, invasion, metastasis, and patient survival and may provide opportunities for therapeutic intervention in pancreatic ductal adenocarcinoma (PDAC). Although never studied as a potential modulator of the immune response in most cancers, Keratin 17 (K17), a biomarker of the most aggressive (basal) molecular subtype of PDAC, is intimately involved in the histogenesis of the immune response in psoriasis, basal cell carcinoma, and cervical squamous cell carcinoma. Thus, we hypothesized that K17 expression could also impact the immune cell response in PDAC, and that uncovering this relationship could provide insight to guide the development of immunotherapeutic opportunities to extend patient survival. METHODS: Multiplex immunohistochemistry (mIHC) and automated image analysis based on novel computational imaging technology were used to decipher the abundance and spatial distribution of T cells, macrophages, and tumor cells, relative to K17 expression in 235 PDACs. RESULTS: K17 expression had profound effects on the exclusion of intratumoral CD8+ T cells and was also associated with decreased numbers of peritumoral CD8+ T cells, CD16+ macrophages, and CD163+ macrophages (p < 0.0001). The differences in the intratumor and peritumoral CD8+ T cell abundance were not impacted by neoadjuvant therapy, tumor stage, grade, lymph node status, histologic subtype, nor KRAS, p53, SMAD4, or CDKN2A mutations. CONCLUSIONS: Thus, K17 expression correlates with major differences in the immune microenvironment that are independent of any tested clinicopathologic or tumor intrinsic variables, suggesting that targeting K17-mediated immune effects on the immune system could restore the innate immunologic response to PDAC and might provide novel opportunities to restore immunotherapeutic approaches for this most deadly form of cancer.

Keratin 17 is a prognostic and predictive biomarker in pancreatic ductal adenocarcinoma.

OBJECTIVES: To determine the role of keratin 17 (K17) as a predictive biomarker for response to chemotherapy by defining thresholds of K17 expression based on immunohistochemical tests that could be used to optimize therapeutic intervention for patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: We profiled K17 expression, a hallmark of the basal molecular subtype of PDAC, by immunohistochemistry in 2 cohorts of formalin-fixed, paraffin-embedded PDACs (n = 305). We determined a K17 threshold of expression to optimize prognostic stratification according to the lowest Akaike information criterion and explored the potential relationship between K17 and chemoresistance by multivariate predictive analyses. RESULTS: Patients with advanced-stage, low K17 PDACs treated using 5-fluorouracil (5-FU)-based chemotherapeutic regimens had 3-fold longer survival than corresponding cases treated with gemcitabine-based chemotherapy. By contrast, PDACs with high K17 did not respond to either regimen. The predictive value of K17 was independent of tumor mutation status and other clinicopathologic variables. CONCLUSIONS: The detection of K17 in 10% or greater of PDAC cells identified patients with shortest survival. Among patients with low K17 PDACs, 5-FU-based treatment was more likely than gemcitabine-based therapies to extend survival.

Enhancing upper tract urothelial carcinoma diagnosis: Utility of cytokeratin 17 and CK20/CD44/p53 immunohistochemical panel.

Upper tract urothelial carcinoma (UTUC) presents diagnostic challenges due to small biopsy specimen size, poor orientation, and technical obstacles that can yield equivocal diagnoses. This uncertainty often mandates repeated biopsies to evaluate the necessity of nephroureterectomy. Prior studies have suggested cytokeratin 17 (CK17) immunostain as an adjunctive tool for diagnosing bladder urothelial neoplasia in both urine cytology and tissue biopsy specimens. We evaluated the utility of CK17 in differentiating UTUC from benign urothelium and its ability to stratify low-grade from high-grade neoplasia. Our study involved a cohort of previously diagnosed cytology (n = 29) and tissue specimens from biopsies and resections (n = 85). We evaluated CK17 staining percentage in cytology and tissue samples and localization patterns in biopsy/resection samples. Our findings showed a statistically significant distinction (p < 0.05) between UTUC and benign tissue specimens based on full thickness localization pattern (odds ratio 8.8 [95% CI 1.53-67.4]). The percentage of CK17 staining failed to significantly differentiate neoplastic from non-neoplastic cases in cytology or tissue samples. Additionally, based on prior research showing the efficacy of CK20/CD44/p53 triple panel in bladder urothelial neoplasia, we utilized tissue microarrays to evaluate if these markers could distinguish UTUC from benign urothelium. We found that CK20/CD44/p53, individually or in combination, could not distinguish urothelial neoplasia from non-neoplasia. Full thickness CK17 urothelial localization by immunohistochemistry was highly reproducible with excellent interobserver agreement and may play a supplementary role in distinguishing upper tract urothelial neoplasia from benign urothelium.

Loss of mutant p53 in HaCaT keratinocytes promotes cadmium-induced keratin 17 expression and cell death.

BACKGROUND: Cadmium exposure induces dermatotoxicity and epidermal barrier disruption and leads to the development of various pathologies. HaCaT cells are immortalized human keratinocytes that are widely used as alternatives to primary human keratinocytes, particularly for evaluating cadmium toxicity. HaCaT cells bear two gain-of-function (GOF) mutations in the TP53 gene, which strongly affect p53 function. Mutant forms of p53 are known to correlate with increased resistance to various stimuli, including exposure to cytotoxic substances. In addition, keratin 17 (KRT17) was recently shown to be highly expressed in HaCaT cells in response to genotoxic stress. Moreover, p53 is a direct transcriptional repressor of KRT17. However, the impact of TP53 mutations in HaCaT cells on the regulation of cell death and keratin 17 expression is unclear. In this study, we aimed to evaluate the impact of p53 on the response to Cd-induced cytotoxicity. METHODS AND RESULTS: Employing the MTT assay and Annexin V/propidium iodide staining, we demonstrated that knockout of TP53 leads to a decrease in the sensitivity of HaCaT cells to the cytotoxic effects of cadmium. Specifically, HaCaT cells with TP53 knockout (TP53 KO HaCaT) exhibited cell death at a cadmium concentration of 10 µM or higher, whereas wild-type cells displayed cell death at a concentration of 30 µM. Furthermore, apoptotic cells were consistently detected in TP53 KO HaCaT cells upon exposure to low concentrations of cadmium (10 and 20 µM) but not in wild-type cells. Our findings also indicate that cadmium cytotoxicity is mediated by reactive oxygen species (ROS), which were significantly increased only in TP53 knockout cells treated with 30 µM cadmium. An examination of proteomic data revealed that TP53 knockout in HaCaT cells resulted in the upregulation of proteins involved in the regulation of apoptosis, redox systems, and DNA repair. Moreover, RT‒qPCR and immunoblotting showed that cadmium toxicity leads to dose-dependent induction of keratin 17 in p53-deficient cells but not in wild-type cells. CONCLUSIONS: The connection between mutant p53 in HaCaT keratinocytes and increased resistance to cadmium toxicity was demonstrated for the first time. Proteomic profiling revealed that TP53 knockout in HaCaT cells led to the activation of apoptosis regulatory circuits, redox systems, and DNA repair. In addition, our data support the involvement of keratin 17 in the regulation of DNA repair and cell death. Apparently, the induction of keratin 17 is p53-independent but may be inhibited by mutant p53.

Diagnosis of verruciform acanthotic vulvar intra-epithelial neoplasia (vaVIN) using CK17, SOX2 and GATA3 immunohistochemistry.

AIMS: Verruciform acanthotic vulvar intra-epithelial neoplasia (vaVIN) is an HPV-independent, p53 wild-type lesion with distinct morphology and documented risk of recurrence and cancer progression. vaVIN is rare, and prospective distinction from non-neoplastic hyperplastic lesions can be difficult. CK17, SOX2 and GATA3 immunohistochemistry has emerging value in the diagnosis of HPV-independent lesions, particularly differentiated VIN. We aimed to test the combined value of these markers in the diagnosis of vaVIN versus its non-neoplastic differentials in the vulva. METHODS AND RESULTS: CK17, SOX2 and GATA3 immunohistochemistry was evaluated on 16 vaVINs and 34 mimickers (verruciform xanthoma, lichen simplex chronicus, lichen sclerosus, psoriasis, pseudo-epitheliomatous hyperplasia). CK17 was scored as 3+ = full-thickness, 2+ = partial-thickness, 1+ = patchy, 0 = absent; SOX2 as 3+ = strong staining ≥ 10% cells, 2+ = moderate, 1 + =weak, 0 = staining in < 10% cells; and GATA3 as pattern 0 = loss in < 25% basal cells, 1 = loss in 25-75% basal cells, 2 = loss in > 75% basal cells. For analysis, results were recorded as positive (CK17 = 3+, SOX2 = 3+, GATA3 = patterns 1/2) or negative (CK17 = 2+/1+/0, SOX2 = 2+/1+/0, GATA3 = pattern 0). CK17, SOX2 and GATA3 positivity was documented in 81, 75 and 58% vaVINs, respectively, versus 32, 17 and 22% of non-neoplastic mimickers, respectively; ≥ 2 marker positivity conferred 83 sensitivity, 88 specificity and 86% accuracy in vaVIN diagnosis. Compared to vaVIN, SOX2 and GATA3 were differentially expressed in lichen sclerosus, lichen simplex chronicus and pseudo-epitheliomatous hyperplasia, whereas CK17 was differentially expressed in verruciform xanthoma and adjacent normal mucosa. CONCLUSIONS: CK17, SOX2 and GATA3 can be useful in the diagnosis of vaVIN and its distinction from hyperplastic non-neoplastic vulvar lesions. Although CK17 has higher sensitivity, SOX2 and GATA3 are more specific, and the combination of all markers shows optimal diagnostic accuracy.

Diagnosis of differentiated dysplasia as a variant of oral epithelial dysplasia.

OBJECTIVES: The World Health Organization's definition of oral epithelial dysplasia includes differentiated dysplasia, which is defined by purely architectural abnormalities of oral mucosa without cytological changes. We analysed differentiated dysplasia's frequency, progression risk and correlation with oral brush cytology. MATERIALS AND METHODS: Cytoarchitectural criteria and expression patterns of keratin 13/17 and ki67 were studied in oral biopsies clinically diagnosed with leukoplakia. Biopsies were assessed for dysplasia and its grade. Available brush cytology findings were obtained from clinical records. RESULTS: We included 159 biopsies from 112 patients (33% differentiated dysplasia; 27% keratosis without dysplasia; oral epithelial dysplasia with atypia of mild, moderate and severe degree including invasive cancers in 9%, 8% and 7%, respectively). Keratin 13 loss and keratin 17 gain were higher in differentiated-dysplasia cases (p < 0.0001), which had the highest hypergranulosis frequency. Keratin 17 expression was associated with higher malignant-transformation rates (p = 0.0028). The transformation rate and time were comparable between dysplasia with atypia and differentiated-dysplasia cases, which had higher progression rates and shorter time periods than keratosis cases without dysplasia (p = 0.08). Cytology prior to differentiated dysplasia all indicated normal oral mucosa. CONCLUSIONS: Keratin 17 but not oral brush cytology can help identify patients with differentiated dysplasia with higher risk for malignant transformation.

WB518, a novel STAT3 inhibitor, effectively alleviates IMQ and TPA-induced animal psoriasis by inhibiting STAT3 phosphorylation and Keratin 17.

OBJECTIVES: Psoriasis is a prevalent chronic inflammatory skin disease in humans that is characterized by frequent relapses and challenging to cure. WB518 is a novel small molecule compound with an undisclosed structure. Therefore, our study aimed to investigate the therapeutic potential of WB518 in vitro and in vivo for the treatment of psoriasis, specifically targeting the abnormal proliferation, aberrant differentiation of epidermal keratinocytes, and pathogenic inflammatory response. MATERIALS AND METHODS: We employed dual luciferase reporter assay to screen compounds capable of inhibiting STAT3 gene transcription. Flow cytometry was utilized to analyze CD3-positive cells. Protein and mRNA levels were assessed through Western blotting, immunofluorescence, immunohistochemistry, and real-time PCR. Cell viability was measured using the MTS assay, while in vivo models of psoriasis induced by IMQ and TPA were employed to study the anti-psoriasis effect of WB518. RESULTS: WB518 was found to significantly reduce the mRNA and protein levels of Keratin 17 (K17) in HaCaT cells by inhibiting the phosphorylation of STAT3 Tyr705 (Y705). In the IMQ and TPA-induced psoriasis mouse model, WB518 effectively improved scaling, epidermal hyperplasia, and inflammation. WB518 also suppressed the expression of inflammatory cytokines, such as interleukin (IL)-1ß, IL-6, IL-17, and IL-23. Furthermore, WB518 decreased the proportion of CD3-positive cells in the psoriatic skin of mice. CONCLUSIONS: WB518 exhibits promising potential as a treatment candidate for psoriasis.

Emerging Prognostic and Predictive Significance of Stress Keratin 17 in HPV-Associated and Non HPV-Associated Human Cancers: A Scoping Review.

A growing body of literature suggests that the expression of cytokeratin 17 (K17) correlates with inferior clinical outcomes across various cancer types. In this scoping review, we aimed to review and map the available clinical evidence of the prognostic and predictive value of K17 in human cancers. PubMed, Web of Science, Embase (via Scopus), Cochrane Central Register of Controlled Trials, and Google Scholar were searched for studies of K17 expression in human cancers. Eligible studies were peer-reviewed, published in English, presented original data, and directly evaluated the association between K17 and clinical outcomes in human cancers. Of the 1705 studies identified in our search, 58 studies met criteria for inclusion. Studies assessed the prognostic significance (n = 54), predictive significance (n = 2), or both the prognostic and predictive significance (n = 2). Altogether, 11 studies (19.0%) investigated the clinical relevance of K17 in cancers with a known etiologic association to HPV; of those, 8 (13.8%) were focused on head and neck squamous cell carcinoma (HNSCC), and 3 (5.1%) were focused on cervical squamous cell carcinoma (SCC). To date, HNSCC, as well as triple-negative breast cancer (TNBC) and pancreatic cancer, were the most frequently studied cancer types. K17 had prognostic significance in 16/17 investigated cancer types and 43/56 studies. Our analysis suggests that K17 is a negative prognostic factor in the majority of studied cancer types, including HPV-associated types such as HNSCC and cervical cancer (13/17), and a positive prognostic factor in 2/17 studied cancer types (urothelial carcinoma of the upper urinary tract and breast cancer). In three out of four predictive studies, K17 was a negative predictive factor for chemotherapy and immune checkpoint blockade therapy response.

Persister cell phenotypes contribute to poor patient outcomes after neoadjuvant chemotherapy in PDAC.

Neoadjuvant chemotherapy can improve the survival of individuals with borderline and unresectable pancreatic ductal adenocarcinoma; however, heterogeneous responses to chemotherapy remain a significant clinical challenge. Here, we performed RNA sequencing (n = 97) and multiplexed immunofluorescence (n = 122) on chemo-naive and postchemotherapy (post-CTX) resected patient samples (chemoradiotherapy excluded) to define the impact of neoadjuvant chemotherapy. Transcriptome analysis combined with high-resolution mapping of whole-tissue sections identified GATA6 (classical), KRT17 (basal-like) and cytochrome P450 3A (CYP3A) coexpressing cells that were preferentially enriched in post-CTX resected samples. The persistence of GATA6hi and KRT17hi cells post-CTX was significantly associated with poor survival after mFOLFIRINOX (mFFX), but not gemcitabine (GEM), treatment. Analysis of organoid models derived from chemo-naive and post-CTX samples demonstrated that CYP3A expression is a predictor of chemotherapy response and that CYP3A-expressing drug detoxification pathways can metabolize the prodrug irinotecan, a constituent of mFFX. These findings identify CYP3A-expressing drug-tolerant cell phenotypes in residual disease that may ultimately inform adjuvant treatment selection.

Tranexamic acid improves psoriasis-like skin inflammation: Evidence from in vivo and in vitro studies.

The chronic disease psoriasis is associated with severe inflammation and abnormal keratinocyte propagation in the skin. Tranexamic acid (TXA), a plasmin inhibitor, is used to cure serious bleeding. We investigated whether TXA ointment mitigated Imiquimod (IMQ)-induced psoriasis-like inflammation. Furthermore, this study investigated the effect of noncytotoxic concentrations of TXA on IL-17-induced human keratinocyte (HaCaT) cells to determine the status of proliferative psoriatic keratinocytes. We found that TXA reduced IMQ-induced psoriasis-like erythema, thickness, scaling, and cumulative scores (erythema plus thickness plus scaling) on the back skin of BALB/c mice. Additionally, TXA decreased ear thickness and suppressed hyperkeratosis, hyperplasia, and inflammation of the ear epidermis in IMQ-induced BALB/c mice. Furthermore, TXA inhibited IMQ-induced splenomegaly in BALB/c mouse models. In IL-17-induced HaCaT cells, TXA inhibited ROS production and IL-8 secretion. Interestingly, TXA suppressed the IL-17-induced NFκB signaling pathway via IKK-mediated IκB degradation. TXA inhibited IL-17-induced activation of the NLRP3 inflammasome through caspase-1 and IL1ß expression. TXA inhibited IL-17-induced NLRP3 inflammasome activation by enhancing autophagy, as indicated by LC3-II accumulation, p62/SQSTM1 expression, ATG4B inhibition, and Beclin-1/Bcl-2 dysregulation. Notably, TXA suppressed IL-17-induced Nrf2-mediated keratin 17 expression. N-acetylcysteine pretreatment reversed the effects of TXA on NFκB, NLRP3 inflammasomes, and the Nrf2-mediated keratin 17 pathway in IL-17-induced HaCaT cells. Results further confirmed that in the ear skin of IMQ-induced mice, psoriasis biomarkers such as NLRP3, IL1ß, Nrf2, and keratin 17 expression were downregulated by TXA treatment. TXA improves IMQ-induced psoriasis-like inflammation in vivo and psoriatic keratinocytes in vitro. Tranexamic acid is a promising future treatment for psoriasis.

RBM15-Mediated m6A Modification of K17 Affects Keratinocytes Response to IL-17A Stimulation in Psoriasis.

OBJECTIVE: Psoriasis is characterized by excessive proliferation and abnormal differentiation of epidermal keratinocytes. This study aimed to reveal the function and mechanism of a N6-methyladenosine (m6A) methyltransferase RNA-binding motif protein 15 (RBM15) in IL-17A-induced keratinocytes. METHODS: A immortalized keratinocyte cell line HaCaT was used to undergo the IL-17A stimulation. The mRNA levels were detected by qRT-PCR, whereas the protein levels were measured by western blotting. The change of keratinocytes proliferation was determined using CCK8 and EdU assays, and the inflammation factors (IL-8 and TNF-α) in keratinocytes were analyzed by qRT-PCR. The m6A modification of Keratin 17 (K17) was confirmed by MeRIP and mRNA stability assays. RESULTS: The levels of RBM15 and K17 in skin samples from patients with psoriasis and IL-17A-induced keratinocytes were upregulated, and showed the positive correlation. Silencing RBM15 suppressed viability, proliferation, and inflammation of keratinocytes that were enhanced by IL-17A stimulation. Moreover, RBM15 knockdown reduced the stability of K17 mRNA via m6A modification method. Since K17 is modified by RBM15, its overexpression relieved the effects of RBM15 knockdown on keratinocytes under IL-17A stimulation. CONCLUSION: This study revealed that RBM15 knockdown suppressed proliferation and inflammation by mediating m6A modification of K17 to reduce K17 stability in IL-17A-induced keratinocytes. Our findings may provide novel idea for improving the treatment of psoriasis.

Interference KRT17 reverses doxorubicin resistance in triple-negative breast cancer cells by Wnt/ß-catenin signaling pathway.

BACKGROUND: Triple-negative breast cancer (TNBC) is a subtype of breast cancer with the highest degree of malignancy and is easily resistant to drugs due to the lack of hormone receptors. Research on the resistance mechanisms in TNBC is particularly important. Keratin 17 (KRT17) is highly expressed in TNBC. Anthracycline doxorubicin (Dox) is a commonly used chemotherapeutic drug for early stage triple-negative breast cancer. OBJECTIVE: This study investigated the role of KRT17 in TNBC-Dox resistance. METHODS: Immuno-histochemical staining, qPCR, western blotting (WB), and immunofluorescence were used to detect the expression of KRT17 in TNBC-Dox-resistant patients and in TNBC-Dox-resistant MDA-MB-468 and MDA-MB-231. the effect of KRT17 on the proliferation and migration in KRT17 knockdown of TNBC-Dox-resistant cells was determined by the CCK8, clone formation, transwell invasion and wound healing assays were used to determine. RESULTS: KRT17 was highly expressed in the TNBC-Dox-resistant cells. Knockdown of KRT17 significantly reduced the IC50s of TNBC-Dox-resistant and parental strains and also reduced the proliferation and invasion abilities of TNBC-Dox-resistant cell lines. KRT17 regulated the Wnt/ß-catenin signaling pathway. The inhibitory effect of KRT17 knockdown on the proliferation and migration of TNBC-Dox-resistant cells was reversed by an activator of the Wnt signaling pathway. CONCLUSION: KRT17 can inhibit the Wnt/ß-catenin signaling pathway, thereby reducing the proliferation and invasion ability of TNBC-Dox-resistant cells.

Keratin 17 Impacts Global Gene Expression and Controls G2/M Cell Cycle Transition in Ionizing Radiation-Induced Skin Damage.

Keratin 17 (K17) is a cytoskeletal protein that is part of the intermediate filaments in epidermal keratinocytes. In K17-/- mice, ionizing radiation induced more severe hair follicle damage, whereas the epidermal inflammatory response was attenuated compared with that in wild-type mice. Both p53 and K17 have a major impact on global gene expression because over 70% of the differentially expressed genes in the skin of wild-type mice showed no expression change in p53-/- or K17-/- skin after ionizing radiation. K17 does not interfere with the dynamics of p53 activation; rather, global p53 binding in the genome is altered in K17-/- mice. The absence of K17 leads to aberrant cell cycle progression and mitotic catastrophe in epidermal keratinocytes, which is due to nuclear retention, thus reducing the degradation of B-Myb, a key regulator of the G2/M cell cycle transition. These results expand our understanding of the role of K17 in regulating global gene expression and ionizing radiation-induced skin damage.

Keratin 17 covalently binds to alpha-enolase and exacerbates proliferation of keratinocytes in psoriasis.

Dysregulated glucose metabolism is an important characteristic of psoriasis. Cytoskeletal protein keratin 17 (K17) is highly expressed in the psoriatic epidermis and contributes to psoriasis pathogenesis. However, whether K17 is involved in the dysregulated glucose metabolism of keratinocytes (KCs) in psoriasis remains unclear. In the present study, loss- and gain-of-function studies showed that elevated K17 expression was critically involved in glycolytic pathway activation in psoriatic KCs. The level of α-enolase (ENO1), a novel potent interaction partner of K17, was also elevated in psoriatic KCs. Knockdown of ENO1 by siRNA or inhibition of ENO1 activity by the inhibitor ENOBlock remarkably suppressed KCs glycolysis and proliferation. Moreover, ENO1 directly interacted with K17 and maintained K17-Ser44 phosphorylation to promote the nuclear translocation of K17, which promoted the transcription of the key glycolysis enzyme lactic dehydrogenase A (LDHA) and resulted in enhanced KCs glycolysis and proliferation in vitro. Finally, either inhibiting the expression and activation of ENO1 or repressing K17-Ser44 phosphorylation significantly alleviated the IMQ-induced psoriasis-like phenotype in vivo. These findings provide new insights into the metabolic profile of psoriatic KCs and suggest that modulation of the ENO1-K17-LDHA axis is a potentially innovative therapeutic approach to psoriasis.

Stress keratin 17 and estrogen support viral persistence and modulate the immune environment during cervicovaginal murine papillomavirus infection.

A murine papillomavirus, MmuPV1, infects both cutaneous and mucosal epithelia of laboratory mice and can be used to model high-risk human papillomavirus (HPV) infection and HPV-associated disease. We have shown that estrogen exacerbates papillomavirus-induced cervical disease in HPV-transgenic mice. We have also previously identified stress keratin 17 (K17) as a host factor that supports MmuPV1-induced cutaneous disease. Here, we sought to test the role of estrogen and K17 in MmuPV1 infection and associated disease in the female reproductive tract. We experimentally infected wild-type and K17 knockout (K17KO) mice with MmuPV1 in the female reproductive tract in the presence or absence of exogenous estrogen for 6 mon. We observed that a significantly higher percentage of K17KO mice cleared the virus as opposed to wild-type mice. In estrogen-treated wild-type mice, the MmuPV1 viral copy number was significantly higher compared to untreated mice by as early as 2 wk postinfection, suggesting that estrogen may help facilitate MmuPV1 infection and/or establishment. Consistent with this, viral clearance was not observed in either wild-type or K17KO mice when treated with estrogen. Furthermore, neoplastic disease progression and cervical carcinogenesis were supported by the presence of K17 and exacerbated by estrogen treatment. Subsequent analyses indicated that estrogen treatment induces a systemic immunosuppressive state in MmuPV1-infected animals and that both estrogen and K17 modulate the local intratumoral immune microenvironment within MmuPV1-induced neoplastic lesions. Collectively, these findings suggest that estrogen and K17 act at multiple stages of papillomavirus-induced disease at least in part via immunomodulatory mechanisms.