Keratin 17 Is a Prognostic Biomarker in Endocervical Glandular Neoplasia

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.

The role of URO17® in diagnosis and follow up of bladder cancer patients

OBJECTIVE

to evaluate the role of urinary URO17® biomarker in the detection of urothelial tumors in haematuria patients and the detection of recurrence in non-muscle invasive bladder urothelial tumors.

MATERIALS AND METHODS

Our study was formed of two cohorts of patients, group I represents patients presenting with haematuria (n = 98), while group II represents patients with known non-muscle invasive bladder cancers on their scheduled follow up cystoscopic investigation (n = 51). For both groups, patients were asked to provide urine samples before cystoscopy, either primary as part of the haematuria investigation or as a scheduled follow-up. Urine samples were sent anonymously for standard urine cytology and URO17® biomarker immunostaining. Results were compared to cystoscopic findings using Chi-square analysis and Fisher's exact test (P < 0.05).

RESULTS

Group I was formed of 98 patients, with an average age of 60 years. URO17® showed 100% sensitivity and 96.15% specificity with a negative predictive value (NPV) of 100 and a positive predictive value (PPV) of 95.83. The results showed statistical significance with P value < 0.001. Group II was formed of 51 patients, with an average age of 75 years. URO17® was shown to have a sensitivity of 85.71% and NPV of 95.45. Eleven patients of group II were on scheduled BacillusCalmette-Guerin (BCG) and another 5 received Mitomycin C (MMC). The overall results of both groups combined (n = 149) showed statistical significance between flexible cystoscopy results and the results of urinary URO17® and urine cytology.

CONCLUSION

URO17® has a potential to be a reliable test for diagnosis and follow up of urothelial cancer patients and a screening tool adjunct to flexible cystoscopy.

TRIAL REGISTRATION

Not applicable as the current study is not a clinical trial, as per according to the National Institutes of Health, "studies that involve a comparison of methods and that do not evaluate the effect of the interventions on the participant do not meet the NIH clinical trial definition."

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.

Reduced Expression of KRT17 Predicts Poor Prognosis in HER2high Breast Cancer

Breast cancer (BC) is one of the most common types of malignancies in women and greatly threatens female health. KRT17 is a member of the keratin (KRT) protein family that is abundant in the outer layer of the skin, where it protects epithelial cells from damage. Although KRT17 has been studied in many types of cancer, the expression of KRT17 in specific subtypes of BC remains to be determined. In our study, we explored the expression and prognostic implications of KRT17 in BC patients using mRNA transcriptome data and clinical BC data from The Cancer Genome Atlas (TCGA). Receiver operating characteristic (ROC) curves and the chi-square test were used to assess the diagnostic value of KRT17 expression. Quantitative real-time PCR (qRT−PCR) analysis of BC cells and tissues and immunohistochemistry (IHC) analysis of clinical tissues were used for external validation. Furthermore, the relationship between KRT17 and immune function was studied by using the CIBERSORT algorithm to predict the proportions of tumor-infiltrating immune cells (TIICs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to explore the potential mechanisms by which KRT17 expression influences patient survival. We found that KRT17 expression was significantly lower in BC tissues than in normal tissues, especially in the luminal-A, luminal-B and human epidermal growth factor receptor-2 (HER2)+ subtypes of BC. ROC analysis revealed that KRT17 expression had moderate diagnostic value. Interestingly, decreased expression of KRT17 was significantly correlated with poor prognosis in BC patients, especially in HER2high and ERhigh patients. This trend was also verified by tissue microarray (TMA) analysis. KRT17 was found to be involved in some antitumor immune pathways, especially the IL-17 signaling pathway, and associated with multiple immune cells, such as natural killer (NK) and CD4+ T cells. In conclusion, high expression of KRT17 predicted favorable prognosis in BC patients with higher HER2 expression. This result may indicate that KRT17 plays a different role depending on the level of HER2 expression and could serve as a promising and sensitive biomarker for the diagnosis and prognostication of HER2high BC.

Construction of a four-mRNA prognostic signature with its ceRNA network in CESC

Cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) tumorigenesis involves a combination of multiple genetic alteration processes. Constructing a survival-associated competing endogenous RNA (ceRNA) network and a multi-mRNA-based prognostic signature model can help us better understand the complexity and genetic characteristics of CESC. In this study, the RNA-seq data and clinical information of CESC patients were downloaded from The Cancer Genome Atlas. Differentially expressed mRNAs, lncRNAs and miRNAs were identified with the edgeR R package. A four-mRNA prognostic signature was developed by multivariate Cox regression analysis. Kaplan–Meier survival with the log-rank tests was performed to assess survival rates. The relationships between overall survival (OS) and clinical parameters were evaluated by Cox regression analysis. A survival-associated ceRNA network was constructed with the multiMiR package and miRcode database. Kyoto encyclopedia of genes and genomes (KEGG) analysis and gene ontology analyses were used to identify the functional role of the ceRNA network in the prognosis of CESC. A total of 298 differentially expressed mRNAs, 8 miRNAs, and 29 lncRNAs were significantly associated with the prognosis of CESC. A prognostic signature model based on 4 mRNAs (OPN3, DAAM2, HENMT1, and CAVIN3) was developed, and the prognostic ability of this signature was indicated by the AUC of 0.726. Patients in the high-risk group exhibited significantly worse OS. The KEGG pathways, TGF-β and Cell adhesion molecules, were significantly enriched. In this study, a CESC-associated ceRNA network was constructed, and a multi-mRNA-based prognostic model for CESC was developed based on the ceRNA network, providing a new perspective for cancer pathogenesis research.

Negative regulation of miR-1288-3p/KRT4 axis through a circular RNA in oral cancer

Circular RNA (circRNA) has been widely reported to be involved in oral squamous cell carcinoma (OSCC), while the way in which hsa_circ_0096042 affects OSCC remains unclear. The hsa_circ_0096042, miR-1288-3p, and KRT4 expression in OSCC tissues and cell lines were detected by quantitative reverse-transcription polymerase chain reaction. Based on the overexpression of hsa_circ_0096042, miR-1288-3p, or KRT4, the viability and proliferation of OSCC cells were analyzed by cell counting kit-8 and colony formation assay, and the protein levels of Bax and Bcl-2 were detected by western blot, and the growth of cancer cells in vivo was analyzed by xenograft experiment. In addition, the database was used to predict the binding of hsa_circ_0096042, miR-1288-3p, and KRT4, and the interaction was confirmed by luciferase, RIP, and RNA pull-down assay. Hsa_circ_0096042 and KRT4 were abnormally downregulated and miR-1288-3p was upregulated in OSCC. Hsa_circ_0096042 overexpression restrained the proliferation and viability of OSCC cells, facilitated apoptosis, and inhibited the growth of cancer cells in vivo. Hsa_circ_0096042 bound to miR-1288-3p, whose upregulation promoted OSCC progression and eliminated the effects of overexpression of hsa_circ_0096042 on OSCC cells. KRT4 was the target gene for miR-1288-3p. Hsa_circ_0096042 plays an antitumor role in OSCC via miR-1288-3p/KRT4 axis.

YB-1 is a positive regulator of KLF5 transcription factor in basal-like breast cancer

Y-box binding protein 1 (YB-1) is a well-known oncogene highly expressed in various cancers, including basal-like breast cancer (BLBC). Beyond its role as a transcription factor, YB-1 is newly defined as an epigenetic regulator involving RNA 5-methylcytosine. However, its specific targets and pro-cancer functions are poorly defined. Here, based on clinical database, we demonstrate a positive correlation between Kruppel-like factor 5 (KLF5) and YB-1 expression in breast cancer patients, but a negative correlation with that of Dachshund homolog 1 (DACH1). Mechanistically, YB-1 enhances KLF5 expression not only through transcriptional activation that can be inhibited by DACH1, but also by stabilizing KLF5 mRNA in a RNA 5-methylcytosine modification-dependent manner. Additionally, ribosomal S6 kinase 2 (RSK2) mediated YB-1 phosphorylation at Ser102 promotes YB-1/KLF5 transcriptional complex formation, which co-regulates the expression of BLBC specific genes, Keratin 16 (KRT16) and lymphocyte antigen 6 family member D (Ly6D), to promote cancer cell proliferation. The RSK inhibitor, LJH685, suppressed BLBC cell tumourigenesis in vivo by disturbing YB-1-KLF5 axis. Our data suggest that YB-1 positively regulates KLF5 at multiple levels to promote BLBC progression. The novel RSK2-YB-1-KLF5-KRT16/Ly6D axis provides candidate diagnostic markers and therapeutic targets for BLBC.

The cytokeratin 17 expression in primary ovarian tumors has diagnostic but not prognostic significance

We assessed the value of cytokeratin 17 (CK17) expression for the differential diagnosis between primary ovarian mucinous tumors and metastases from the gastrointestinal tract (GIT) and the significance of CK17 expression in a broad spectrum of primary ovarian tumors with respect to their prognosis. The sample set consisted of 554 primary ovarian tumors and 255 GIT tumors. In the primary ovarian tumors, a higher CK17 expression (in > 10% of tumors cells) was present only in 0-11.4% of all tumors (including mucinous tumors, micropapillary serous borderline tumors, clear cell, endometrioid, and high-grade serous carcinomas). The only exception was low-grade serous carcinoma, where higher CK17 expression was present in 24% of cases. Concerning GIT tumors, the higher levels of CK 17 expression (in > 10% of tumor cells) were observed in the upper GIT tumors (68.5% of pancreatic ductal adenocarcinoma, 61.6% of gallbladder adenocarcinoma, and 46% of gastric adenocarcinoma), which differs substantially not only from most of the primary ovarian tumors, but also from colorectal carcinoma (3.7%; p < 0.001). The results of our study suggest that expression of CK17 can potentially be used as an adjunct marker in differential diagnosis between primary ovarian mucinous tumors and metastases from the upper GIT, but not from colorectal carcinoma. However, in GIT tumors, CK17 can be used in the differential diagnosis between adenocarcinomas of the upper and lower GIT. Statistical analysis did not reveal strong association of CK17 expression with clinicopathological variables or patient outcomes in any primary ovarian tumors.

Added value of radiomics analysis in MRI invisible early-stage cervical cancers

OBJECTIVES

To determine the diagnostic ability of cervical mucosa radiomics signature of sagittal T2WI and T1 contrast-enhanced (CE) imaging in detecting early-stage cervical cancers with negative MRI.

METHODS

Preoperative images of postoperative pathology confirmed early-stage cervical cancer patients and normal cervix patients admitted to our hospital between January 2013 and December 2020 were retrospectively reviewed. Patients with cancer signals on T2WI, T1CE and DWI were deleted. Regions of interests (ROIs) were delineated on cervical mucosa (from cervical canal to cervical dome) with 5 mm width on sagittal T2WI and T1CE. The maximum-relevance and minimumredundancy (mRMR) and least absolute shrinkage and selection operator (LASSO) methods were used for the calculation of radiomics signature scores. Diagnostic performance was assessed and compared between radiomics prediction models (model 1: T1CE; model 2: T2WI; model 3: model one combined with model 2). Differential diagnostic ability of radiomics signature in detecting lymphatic vascular space invasion (LVSI) was further explored.

RESULTS

Diagnostic performance of model three was higher than model 1 and model 2 both in primary (model 3 0.874, model 1 0.857, model 2 0.816) and validation (model 3 0.853, model 1 0.847, model 2 0.634) cohorts. Model 3 showed statistical diagnostic difference compared with model 2 (primary p = 0.008, validation p = 0.000). However, the diagnostic improvement ability of model 3 showed no statistical difference compared with model 1 (primary p = 0.351, validation p = 0.739). Diagnostic efficiency of model 3 in detecting LVSI was not apparent (AUC 0.64).

CONCLUSIONS

Radiomics analysis of cervical mucosa combining T1CE and T2WI is promising for predicting MRI invisible early-stage cervical cancers, however further ability in detecting LVSI was not apparent.

ADVANCES IN KNOWLEDGE

Conventional MRI was originally defined as meaningless in very early-stage cervical cancers. However, whether MRI radiomics analysis of cervical mucosa can detecting tiny changes of invisible early stage cervical cancers has not been researched yet.

Keratin 17 Promotes T Cell Response in Allergic Contact Dermatitis by Upregulating C-C Motif Chemokine Ligand 20

Allergic contact dermatitis (ACD) is a delayed-type hypersensitivity response to skin contact allergens in which keratinocytes are critical in the initiation of early responses. Keratin 17 (K17) is a cytoskeletal protein inducible under stressful conditions and regulates multiple cellular processes, especially in skin inflammatory diseases; however, knowledge regarding its contribution to ACD pathogenesis remains ill defined. In the present study, we clarified the proinflammatory role of K17 in an oxazolone (OXA)-induced contact hypersensitivity (CHS) murine model and identified the underlying molecular mechanisms. Our results showed that K17 was highly expressed in the lesional skin of ACD patients and OXA-induced CHS mice. Mice lacking K17 exhibited alleviated OXA-induced skin inflammation, including milder ear swelling, a reduced frequency of T cell infiltration, and decreased inflammatory cytokine levels. In vitro, K17 stimulated and activated human keratinocytes to produce plenty of proinflammatory mediators, especially the chemokine CCL20, and promoted keratinocyte-mediated T cell trafficking. The neutralization of CCL20 with a CCL20-neutralizing monoclonal antibody significantly alleviated OXA-induced skin inflammation in vivo. Moreover, K17 could translocate into the nucleus of activated keratinocytes through a process dependent on the nuclear-localization signal (NLS) and nuclear-export signal (NES) sequences, thus facilitating the activation and nuclear translocation of signal transducer and activator of transcription 3 (STAT3), further promoting the production of CCL20 and T cell trafficking to the lesional skin. Taken together, these results highlight the novel roles of K17 in driving allergen-induced skin inflammation and suggest targeting K17 as a potential strategy for ACD.

Abnormal keratin expression pattern in prurigo nodularis epidermis

Background

Prurigo nodularis (PN) is a highly pruritic, chronic dermatosis and difficult to treat. PN lesions are characterized by existence of many hyperkeratotic, erosive papules and nodules. However, the pathogenesis of PN still remains unelucidated.

Aim

To clarify the keratin role in the epidermis hyperproliferation, the keratin expression pattern in the PN lesional skin.

Methods

In this study, we enrolled 24 patients with PN and 9 healthy control volunteers. K1/K10, K5/K14, K6/K16/K17 expression pattern were investigated by using immunohistochemical staining.

Results

The lesional skin consists of the thickened spinous layers, in which active cell division was found. K5/K14 were upregulated in PN lesional epidermis, the staining signal localized in the basal layer and lower suprabasal layers. Hyperproliferation‐associated K6 was found in all layers of epidermal lesional skin, especially in the spinous layers. In contrast, K16 was only detected in the basal and lower suprabasal layers, K17 was observed in the basal and spinous layers. Terminal differential keratins K1/K10 were upregulated, detected in the pan‐epidermis, but spared in the basal and low suprabasal layers.

Conclusion

The keratinocytes enter an alternative differentiation pathway, which are responsible for the activated keratinocyte phenotype, abnormal keratins expression potentially contributes to the keratinocytes proliferation, subsequently lead to increased lesional skin epidermis thickness, hyperkeratiosis and alteration of skin barrier properties.

Keratin 17 Is a Novel Cytologic Biomarker for Urothelial Carcinoma Diagnosis

OBJECTIVES

The microscopic features of urine cytology specimens are subjective and may not reliably distinguish between benign urothelial cells and low-grade urothelial carcinoma (UC). Prior studies demonstrated that keratin 17 (K17) detection in biopsies is highly sensitive for UC. The current study aimed to define K17 diagnostic test performance for initial screening and detect recurrent UC in urine specimens.

METHODS

K17 was detected by immunocytochemistry (ICC) in consecutively collected urine specimens (2018-2019). A qualitative score for the K17 test was determined in 81 samples (discovery cohort) and validated in 98 samples (validation cohort). K17 sensitivity and specificity were analyzed in both cohorts across all grades of UC.

RESULTS

Based on the discovery cohort, the presence of 5 or more K17 immunoreactive urothelial cells (area under the curve = 0.90; P < .001) was the optimal threshold to define a K17-positive test. The sensitivity of the K17 ICC test for biopsy-confirmed UC was 35 of 36 (97%) and 18 of 21 (86%) in the discovery and validation cohorts, respectively. K17 was positive in 16 of 19 (84%) specimens with biopsy-confirmed low-grade UC and in 34 of 34 (100%) of specimens with high-grade UC.

CONCLUSIONS

K17 ICC is a highly sensitive diagnostic test for initial screening and detection of recurrence across all grades of UC.

A role for keratin 17 during DNA damage response and tumor initiation

High levels of the intermediate filament protein keratin 17 (K17) are associated with poor prognoses for several human carcinomas. Studies in mouse models have shown that K17 expression is positively associated with growth, survival, and inflammation in skin and that lack of K17 delays onset of tumorigenesis. K17 occurs in the nucleus of human and mouse tumor keratinocytes where it impacts chromatin architecture, gene expression, and cell proliferation. We report here that K17 is induced following DNA damage and promotes keratinocyte survival. The presence of nuclear K17 is required at an early stage of the double-stranded break (DSB) arm of the DNA damage and repair (DDR) cascade, consistent with its ability to associate with key DDR effectors, including γ-H2A.X, 53BP1, and DNA-PKcs. Mice lacking K17 or with attenuated K17 nuclear import showed curtailed initiation in a two-step skin carcinogenesis paradigm. The impact of nuclear-localized K17 on DDR and cell survival provides a basis for the link between K17 induction and poor clinical outcomes for several human carcinomas.

iTRAQ-Based Proteomic Profiling of Potential Biomarkers in Rat Serum for Uranium Tailing Suspension Intratracheal Instillation

Protection against low-dose ionizing radiation is of great significance. Uranium tailings are formed as a byproduct of uranium mining and a potential risk to organisms. In this study, we identified potential biomarkers associated with exposure to low-dose radiation from uranium tailings. We established a Wistar rat model of low dose rate irradiation by intratracheal instillation of a uranium tailing suspension. We observed pathological changes in the liver, lung, and kidney tissues of the rats. Using isobaric tags for relative and absolute quantification, we screened 17 common differentially expressed proteins in three dose groups. We chose alpha-1 antiproteinase (Serpina1), keratin 17 (Krt17), and aldehyde dehydrogenase (Aldh3a1) for further investigation. Our data showed that expression of Serpina1, Krt17, and Aldh3a1 had changed after the intratracheal instillation in rats, which may be potential biomarkers for uranium tailing low-dose irradiation. However, the underlying mechanisms require further investigation.

The role of URO17™ biomarker to enhance diagnosis of urothelial cancer in new hematuria patients—First European Data

Introduction and objectives

Novel biomarker research is vital for the progression of safe and thorough diagnostic medicine. There is now a need to improve the diagnosis of bladder cancer via a noninvasive urine test while balancing the risks of harm from investigational procedures, such as cystoscopy and radiological tests, against the likelihood of malignancy. We evaluate the diagnostic accuracy and sensitivity of Uro17™ urinary biomarker for the detection of urothelial cancer in hematuria patients in a prospective blinded validation study. Uro17™ is an immunobiomarker which binds to the oncoprotein Keratin 17, which is involved in the replication cycle of malignant cells. This study compared cystoscopic and histological investigations against Uro17™ results in patients being investigated for symptoms of urothelial cancer.

Materials and methods

After receiving both local and national ethics/protocol approval, 71 patients were consented and recruited into the study. All patients were scheduled to undergo cystoscopic investigation, and following recruitment, a urine sample was collected. Urine samples were anonymized and processed as per standard cytology protocols and stained using Uro17™ immunobiomarker. The pathologists assessing the results were blinded to the patient and background history, and the results were compared to the biopsy histology.

Results

The full cohort of enrolled patients consisted of 71 participants included. There were 55 males and 16 females, with an average age of 70. Thirteen were current smokers, 42 ex‐smokers, and 16 nonsmokers. The malignancies detected included both muscle‐invasive (n = 6) and non‐muscle‐invasive tumors (n = 38), and tumors of all grades and carcinoma in situ. Uro17™ was shown to have an overall sensitivity of 100% and a specificity of 92.6%, with a positive predictive value of 0.957 and negative predictive value of 1. Uro17™ investigation was positive in every case of urothelial malignancy.

Conclusions

Our current data indicates Uro17™ is a highly sensitive noninvasive bladder cancer urine detection test that can improve the diagnosis of Bladder cancer. This can further improve diagnostic capabilities in primary care, reduce the number of referrals to Urology department, and reduce the number of unnecessary invasive procedures for new patients with a suspected urinary bladder cancer.

Keratin 17 is induced in prurigo nodularis lesions

Prurigo nodularis (PN) is a highly pruritic chronic inflammatory dermatosis with unknown pathogenesis. It is characterized by the existence of many hyperkeratotic, erosive papules and nodules, and the development of lesions may be associated with hyperproliferation and aberrant differentiation of keratinocytes. Keratin 17 (K17) is overexpressed selectively in human proliferative skin diseases, promoting keratinocyte proliferation not found in normal epidermis. In this study, we investigated the mRNA levels and protein levels of K17 in lesional and perilesional skin using quantitative real-time polymerase chain reaction and western blot. We demonstrate that K17 is induced in lesional and perilesional skin in PN. The mRNA expression level of K17 was upregulated in PN lesions (P < 0.01), with multifold changes in the PN lesion (normalized to glyceraldehyde-3-phosphate dehydrogenase as the housekeeping gene) showing a median positive correlation with PRUNOSI (P < 0.05). The protein level of K17 was also markedly increased in PN lesions (P < 0.01). In conclusion, K17 is highly induced in PN lesions, which may contribute to the proliferation of keratinocytes and the pathogenesis of PN.

Keratin 17 Expression Predicts Poor Clinical Outcome in Patients With Advanced Esophageal Squamous Cell Carcinoma

The major roles of keratin 17 (K17) as a prognostic biomarker have been highlighted in a range of human malignancies. However, its relevance to esophageal squamous cell carcinoma (ESCC) remains unexplored. In this study, the relationship between K17 expression and clinicopathologic parameters and survival were determined by RNA sequencing (RNA-Seq) in 90 ESCCs and by immunohistochemistry (IHC) in 68 ESCCs. K17 expression was significantly higher in ESCC than in paired normal tissues at both the messenger RNA and protein levels. K17 messenger RNA and staining by IHC were significantly correlated with aggressive characteristics, including advanced clinical stage, invasion depth, and lymph node metastases; and were predictive of poor prognosis in advanced disease patients. Furthermore, K17 expression was detected by IHC in high-grade premalignant lesions of the esophageal mucosa, suggesting that K17 could also be a biomarker of dysplasia of the esophageal mucosa. Overall, this study established that K17 is a negative prognostic biomarker for the most common subtype of esophageal cancer.

Silencing of keratin 17 by lentivirus-mediated short hairpin RNA inhibits the proliferation of PANC-1 human pancreatic cancer cells

Keratin 17 (KRT17) has been demonstrated to be a potential biological marker for the prediction of prognosis in particular types of cancer. The aim of the present study was to investigate the molecular mechanisms underlying the function of KRT17 in the pancreatic cancer (PAC) cell line PANC-1 and the potential of KRT17 as a therapeutic target for PAC. KRT17 expression levels were analyzed using quantitative PCR and compared with histological data using bioinformatics tools in PAC samples and three human PAC cell lines. Cell proliferation was determined using an MTT assay, in addition to cell cycle distribution and apoptosis analysis using flow cytometry, colony formation assay using Giemsa staining and cell motility analysis using a Transwell migration assay. Tumor growth was evaluated in vivo in nude mice. The expression levels of a number of signaling molecules were measured to establish the potential mechanism by which silencing KRT17 expression affected PAC PANC-1 cells. Increased levels of KRT17 expression were observed in human PAC compared with normal tissues, as well as in three human PAC cell lines (MIA PaCa-2, PANC-1 and KP-3 cells) compared with the H6c7 human immortal pancreatic duct epithelial cell line. High expression levels of KRT17 in PAC samples were associated with poor overall survival (P=0.036) and disease-free survival (P=0.017). Lentivirus-mediated KRT17 silencing inhibited cell proliferation, colony formation and migration, but promoted apoptosis and resulted in cell cycle arrest in the G₀/G₁ phase in PANC-1 cells. In addition, KRT17 knockdown inhibited in vivo tumor growth. KRT17 knockdown induced dysregulation of ERK1/2 and upregulation of the pro-apoptotic Bcl-2 protein Bad. In conclusion, the present study demonstrated that elevated KRT17 levels are positively associated with pancreatic cancer progression; KRT17 knockdown suppressed cell growth, colony formation, migration and tumor growth, and induced apoptosis and cell cycle arrest, affecting ERK1/2/Bad signaling. Therefore, the results of the present study suggested that KRT17 may be a potential target for the treatment of pancreatic cancer.

SOX17 expression and its down-regulation by promoter methylation in cervical adenocarcinoma in situ and adenocarcinoma

AIMS

SOX17 expression has not been studied in glandular lesions of the uterine cervix like adenocarcinoma in situ (AIS) and invasive adenocarcinomas (AdC), whereas SOX17 promoter CpG island methylation has been reported. Therefore, the aim of this study was to relate the topographical distribution of SOX17 expression and SOX17 methylation status to each other, and to SOX2 expression, human papillomavirus (HPV) type, and physical status of the virus.

METHODS AND RESULTS

Immunohistochemistry was used in 45 cases to assess expression of SOX17 and SOX2. SOX17 promoter methylation was determined in 25 cases by means of bisulphite conversion and methylation-specific polymerase chain reaction. SOX17 and SOX2 showed a mutually exclusive expression pattern in normal epithelium, with a sharp delineation in the squamocolumnar junction. SOX17 was found in endocervical columnar and reserve cells, whereas SOX2 was exclusively found in squamous epithelium. In both glandular lesions and cases with coexisting glandular and squamous intraepithelial components, a complex combination of SOX17 and SOX2 expression patterns was seen and mutually exclusive expression was lost. Frequently, gain of expression of SOX2 was found and expression of SOX17 was lost. Methylation of the CpG island in the SOX17 promoter was shown to be strongly associated with loss of expression of SOX17 (P = 0.0016).

CONCLUSIONS

In this study, we show for the first time a direct correlation between the topographical distribution of SOX17 expression and the methylation status of its gene promoter. This explains the heterogeneity of SOX17 expression in the glandular lesions of the cervix. No correlation was found between HPV type and physical status of the virus on the one hand and methylation status on the other.

Dual role of KRT17: development of papillary renal cell tumor and progression of conventional renal cell carcinoma

Expression of KRT17 has been described in multi-layered epithelia as well as in tumors derived from these cells. In cancers arising from KRT17 negative single layered epithelia neo-expression of KRT17 has been associated with tumor progression. To obtain more insight into the biology of kidney cancers we have investigated KRT17 expression by immunohistochemistry in normal kidney, in papillary preneoplastic lesions and in 151 papillary and 692 conventional renal cell carcinomas placed on tissue microarray. We found a positive staining in ureteric bud and collecting duct cells in foetal kidney, in all papillary preneoplastic lesions and also in 77% of the 151 papillary renal cell tumors indicating a continuos KRT17 expression during tumor development. The neo-expression of KRT17 in conventional renal cell carcinomas, which derives from KRT17 negative proximal tubules showed a significant correlation with postoperative tumor relapse (RR=2.50; 95% CI=1.59-3.94; p<0.001). In conclusion, the continuous expression of KRT17 from emerging fetal kidney tubules and microscopic pre-neoplastic lesions towards papillary renal cell tumors and its neo-expression in aggressive growing conventional renal cell carcinomas reflects the multiple function of KRT17 in kidney cancers with distinct natural history. This should be taken into account in clinical managements and therapy.

Keratin 17 identifies the most lethal molecular subtype of pancreatic cancer

Although the overall five-year survival of patients with pancreatic ductal adenocarcinoma (PDAC) is dismal, there are survival differences between cases with clinically and pathologically indistinguishable characteristics, suggesting that there are uncharacterized properties that drive tumor progression. Recent mRNA sequencing studies reported gene-expression signatures that define PDAC molecular subtypes that correlate with differences in survival. We previously identified Keratin 17 (K17) as a negative prognostic biomarker in other cancer types. Here, we set out to determine if K17 is as accurate as molecular subtyping of PDAC to identify patients with the shortest survival. K17 mRNA was analyzed in two independent PDAC cohorts for discovery (n = 124) and validation (n = 145). Immunohistochemical localization and scoring of K17 immunohistochemistry (IHC) was performed in a third independent cohort (n = 74). Kaplan-Meier and Cox proportional-hazard regression models were analyzed to determine cancer specific survival differences in low vs. high mRNA K17 expressing cases. We established that K17 expression in PDACs defines the most aggressive form of the disease. By using Cox proportional hazard ratio, we found that increased expression of K17 at the IHC level is also associated with decreased survival of PDAC patients. Additionally, within PDACs of advanced stage and negative surgical margins, K17 at both mRNA and IHC level is sufficient to identify the subgroup with the shortest survival. These results identify K17 as a novel negative prognostic biomarker that could inform patient management decisions.

TFAP2A Induced KRT16 as an Oncogene in Lung Adenocarcinoma via EMT

Objectives: keratin 16 (KRT16) is a type I cytokeratin that overexpressed in many kinds of cancers, but unlike other keratins, KRT16 was poorly studied, so the aim of current study was to determine the biological role of KRT16 in lung adenocarcinoma (LUAD).

Materials and Methods: by utilizing open access data, we determined KRT16 expression in LUAD. After that we evaluated the biological role of KRT16 in-vitro and in-vivo. We also explored the reason for KRT16 overexpression. Last, we explored the clinical significance of KRT16 in LUAD.

Results: we found KRT16 is overexpressed in LUAD and positively correlated with lymph node metastasis. Knockdown of KRT16 significantly influenced the LUAD cells' migration, invasion, proliferation and epithelial-mesenchymal transition (EMT). Moreover, TFAP2A could transcriptionally overexpress KRT16, which contributed to the TFAP2A tumorigenicity. Last, we determined that high level of KRT16 predicts poor prognosis of LUAD patients.

Conclusions: our data indicate that, TFAP2A induced KRT16 overexpression promotes tumorigenicity in LUAD via EMT, and KRT16 expression could serve as an independent prognosis marker.

Keratin 17 is a sensitive and specific biomarker of urothelial neoplasia

There is a clinical need to identify novel biomarkers to improve diagnostic accuracy for the detection of urothelial tumors. The current study aimed to evaluate keratin 17 (K17), an oncoprotein that drives cell cycle progression in cancers of multiple anatomic sites, as a diagnostic biomarker of urothelial neoplasia in bladder biopsies and in urine cytology specimens. We evaluated K17 expression by immunohistochemistry in formalin-fixed, paraffin embedded tissue specimens of non-papillary invasive urothelial carcinoma (UC) (classical histological cases), high grade papillary UC (PUC-LG), low grade papillary UC (PUC-HG), papillary urothelial neoplasia of low malignant potential (PUNLMP), and normal bladder mucosa. A threshold was established to dichotomize K17 status in tissue specimens as positive vs. negative, based on the proportion of cells that showed strong staining. In addition, K17 immunocytochemistry was performed on urine cytology slides, scoring positive test results based on the detection of K17 in any urothelial cells. Mann-Whitney and receiver operating characteristic analyses were used to compare K17 expression between histologic diagnostic categories. The median proportion of K17 positive tumor cells was 70% (range 20-90%) in PUNLMP, 30% (range 5-100%) in PUC-LG, 20% (range 1-100%), in PUC-HG, 35% (range 5-100%) in UC but staining was rarely detected (range 0-10%) in normal urothelial mucosa. Defining cases in which K17 was detected in ≥10% of cells were considered positive, the sensitivity of K17 in biopsies was 89% (95% CI: 80-96%) and the specificity was 88% (95% CI: 70-95%) to distinguish malignant lesions (PUC-LG, PUC-HG, and UC) from normal urothelial mucosa. Furthermore, K17 immunocytochemistry had a sensitivity of 100% and a specificity of 96% for urothelial carcinoma in 112 selected urine specimens. Thus, K17 is a sensitive and specific biomarker of urothelial neoplasia in tissue specimens and should be further explored as a novel biomarker for the cytologic diagnosis of urine specimens.

Overview of established and emerging immunohistochemical biomarkers and their role in correlative studies in MRI

Clinical practice in radiology and pathology requires professional expertise and many years of training to visually evaluate and interpret abnormal phenotypic features in medical images and tissue sections to generate diagnoses that guide patient management and treatment. Recent advances in digital image analysis methods and machine learning have led to significant interest in extracting additional information from medical and digital whole-slide images in radiology and pathology, respectively. This has led to significant interest and research in radiomics and pathomics to correlate phenotypic features of disease with image analytics in order to identify image-based biomarkers. The expanding role of big data in radiology and pathology parallels the development and role of immunohistochemistry (IHC) in the daily practice of pathology. IHC methods were initially developed to provide additional information to help classify tumors and then transformed into an indispensable tool to guide treatment in many types of cancer. IHC markers are used in daily practice to identify specific types of cells and highlight their distributions in tissues in order to distinguish benign from neoplastic cells, determine tumor origin, subclassify neoplasms, and support and confirm diagnoses. In this regard, radiomics, pathomics, and IHC methods are very similar since they enable the extraction of image-based features to characterize various properties of diseases. Due to the dramatic advancements in recent radiomics research, we provide a brief overview of the role of established and emerging IHC biomarkers in various tumor types that have been correlated with radiologic biomarkers to improve diagnostic accuracy, predict prognosis, guide patient management, and select treatment strategies. Level of Evidence: 5 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2020;51:341-354.

Keratin 17 in disease pathogenesis: from cancer to dermatoses

Keratin 17 (K17) is a type I intermediate filament mainly expressed in the basal cells of epithelia. As a multifaceted cytoskeletal protein, K17 regulates a myriad of biological processes, including cell proliferation and growth, skin inflammation and hair follicle cycling. Aberrant overexpression of K17 is found in various diseases ranging from psoriasis to malignancies such as breast, cervical, oral squamous and gastric carcinomas. Moreover, genetic mutation in KRT17 is related to tissue-specific diseases, represented by steatocystoma multiplex and pachyonychia congenita. In this review, we summarize our findings concerning the regulatory mechanisms of K17 overexpression in psoriasis and compare them to the literature relating to other diseases. We discuss data that proinflammatory cytokines, including interleukin-17 (IL-17), IL-22, interferon-gamma (IFN-γ), transforming growth factor-beta (TGF-β) and transcription factors glioma-associated oncogene homolog 1/2 (Gli1/2), Nrf2 and p53 can regulate K17 by transcriptional and translational control. Moreover, post-translational modification, including phosphorylation and ubiquitination, is involved in the regulation of K17 stability and biological functions. We therefore review the current understanding of the K17 regulatory mechanism and its pathogenic role in diseases from dermatoses to cancer. Prospects for anti-K17 therapy in diagnosis, prognosis and disease treatment are also discussed. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Elevated expression of keratin 17 in oropharyngeal squamous cell carcinoma is associated with decreased survival

BACKGROUND

Overexpression of keratin 17 (K17) is highly associated with poor prognosis in squamous cell carcinoma (SCC) of the cervix. This study was performed to (1) determine whether K17 may be a prognostic biomarker in head and neck squamous cell carcinoma (HNSCC) and (2) to establish if K17 expression is associated with human papillomavirus (HPV) status.

METHODS

Immunohistochemical staining was performed for K17 of oral, oropharyngeal, and laryngeal SCCs, and normal oropharyngeal mucosa. The HPV status was determined using polymerase chain reaction (PCR).

RESULTS

Elevated K17 expression was significantly associated with an overall decreased patient survival (P = .02) and, more specifically, in patients with oropharyngeal SCC (P = .01). When controlling for HPV status and tumor location K17 was still a significant predictor of survival (P = .01).

CONCLUSION

Therefore, K17 is a novel prognostic biomarker of poor survival for patients with HNSCCs, controlling for anatomic site and HPV status.