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.

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.

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.

Keratin 17 testing in pancreatic cancer needle aspiration biopsies predicts survival

BACKGROUND

Although pancreatic ductal adenocarcinoma (PDAC) has one of the lowest 5-year survival rates of all cancers, differences in survival exist between patients with clinically identical characteristics. The authors previously demonstrated that keratin 17 (K17) expression in PDAC, measured by RNA sequencing or immunohistochemistry (IHC), is an independent negative prognostic biomarker. Only 20% of cases are candidates for surgical resection, but most patients are diagnosed by needle aspiration biopsy (NAB). The aims of this study were to determine whether there was a correlation in K17 scores detected in matched NABs and surgical resection tissue sections and whether K17 IHC in NAB cell block specimens could be used as a negative prognostic biomarker in PDAC.

METHODS

K17 IHC was performed for a cohort of 70 patients who had matched NAB cell block and surgical resection samples to analyze the correlation of K17 expression levels. K17 IHC was also performed in cell blocks from discovery and validation cohorts. Kaplan-Meier and Cox proportional hazards regression models were analyzed to determine survival differences in cases with different levels of K17 IHC expression.

RESULTS

K17 IHC expression correlated in matched NABs and resection tissues. NAB samples were classified as high for K17 when ≥80% of tumor cells showed strong (2+) staining. High-K17 cases, including stage-matched cases, had shorter survival.

CONCLUSIONS

K17 has been identified as a robust and independent prognostic biomarker that stratifies clinical outcomes for cases that are diagnosed by NAB. Testing for K17 also has the potential to inform clinical decisions for optimization of chemotherapeutic interventions.

Keratin 17 is Not Always a Marker of Proliferation of Keratinocytes in Skin Diseases

Purpose

Keratin 17 (K17) is an embryonic keratin and overexpression is seen in psoriasis, which is a hyperproliferation skin disease. Nonetheless, whether it is also highly expressed in other proliferative skin diseases remains unclear. The aim of this study is to explore the expression of K17 in cutaneous lichen planus (CLP), lichen simplex chronicus (LSC), and prurigo nodularis (PN).

Methods

A total of 20 skin samples from CLP lesions, 20 from LSC lesions, 20 from PN lesions, and 10 healthy adult skin tissues were obtained. Then, the expression of K17 was analyzed using immunohistochemistry on paraffin-embedded tissue sections. Furthermore, quantitative and semi-quantitative immunohistochemical scores of K17 were independently evaluated under a microscope by 2 dermatologists.

Results

Immunohistochemical analysis revealed that in normal skin, K17 was minimally expressed. Nevertheless, it was highly expressed in all epidermal layers in CLP lesions (P-value <0.01), and negatively expressed in LSC and PN lesions (all P-value >0.05). The average gray value of K17 in CLP was 151.153±13.985 (P-value <0.001), while the average values of K17 in LSC and PN were 178.720±12.001 and 181.316±8.920, respectively (all P-value >0.05).

Conclusion

K17 is potentially expressed in certain inflammatory skin diseases, including psoriasis and lichen planus. Besides, it is not always a marker of hyperproliferation of keratinocytes in skin diseases.

Ureteric Bud-derivatives in Wilms Tumor and Nephrogenic Rest

BACKGROUND/AIM

Recent studies suggest that not only the nephrogenic blastema but also the ureteric bud is involved in oncogenesis of Wilms' tumor (WT). However, the occurrence of ureteric bud (UB) derivatives in nephrogenic rest is not yet known. The aim of our study was to find UB derivatives in WT.

MATERIALS AND METHODS

Keratin 17 (KRT17) is expressed exclusively in UB in foetal kidneys. In this study KRT17 immunohistochemistry was used to detect UB-derivatives in 21 triphasic, 2 stromal and 3 epithelial predominant WTs and 9 nephrogenic rests.

RESULTS

We have detected KRT17 positive tubular structures resembling UB in 3 of 9 nephrogenic rests and 15 of 26 WTs.

CONCLUSION

Not only the metanephric blastema but also the UB is involved in the histogenesis of nephrogenic rest and WT.

Keratin 17 knockdown suppressed malignancy and cisplatin tolerance of bladder cancer cells, as well as the activation of AKT and ERK pathway

INTRODUCTION

Bladder cancer (BCa) is one the most common urinary system malignancies and approximately one quarter of diagnosis is invasive muscle-invasive BCa. Accumulating evidence revealed that keratin 17 (KRT17) is closely related to the prognosis and progression of various tumors including a recent study also implying the potential role of KRT17 in the diagnosis of BCa. However, the specific role of KRT17 in BCa remains to be elucidated.

MATERIAL AND METHODS

The expression of KRT17 in 5637 BCa cells and SV-HUC-1 normal human urothelial cells was detected using quantitative real-time PCR (qRT-PCR) and western blot. Short hairpin RNA targeting KRT17 was used to knockdown KRT17 in BCa cells. The colony formation was assessed and the proliferation of cells was studied by Cell Counting Kit-8 (CCK-8). Invasion and epithelial-mesenchymal transition (EMT) capacity of BCa cells were assessed using transwell assay and western blot, respectively. Cisplatin sensitivity of cancer cells was measured by evaluating the cell viability using CCK-8 assay. The downstream pathway of KRT17 was explored by western blot.

RESULTS

The expression of KRT17 was elevated in BCa cells in comparison with the normal human urothelial cell at the mRNA and protein levels. The in vitro assays demonstrated that KRT17 interference affected the proliferation, colony formation and invasion capacity of BCa cells, as well as EMT. Furthermore, knockdown of KRT17 enhanced cisplatin sensitivity in BCa cells. Mechanically, KRT17 ablation led to the inactivation of both AKT and ERK pathways.

CONCLUSIONS

Our results elucidate the vital role of KRT17 in the development of malignancy of BCa cells, probably by the activation of AKT and ERK pathways and suggest that it may represent a novel therapeutic target for BCa.

Current knowledge on autoantigens and autoantibodies in psoriasis

In the past decades, clinical and experimental evidence has demonstrated that psoriasis is an immune-mediated inflammatory disease of the skin that occurs in genetically susceptible individuals. Psoriasis also shows clear autoimmune pathomechanisms, but specific cellular targets for the onset and maintenance of psoriatic lesions were not established until 2014. Since then, four psoriasis autoantigens were discovered, namely cathelicidin LL-37, melanocytic ADAMTSL5, lipid antigen PLA2G4D and keratin 17. Autoreactive T cells against these autoantigens were found in a number of patients with moderate-to-severe plaque psoriasis. Moreover, the discovery of autoantibodies against LL-37 and ADAMTSL5 and their strong association with psoriatic arthritis (PsA) suggest a potential role of these autoantibodies in the pathogenesis of PsA. This review discusses the current studies on psoriatic autoantigens and the associated circulating autoantibodies and their mechanisms involved in the development and maintenance of psoriatic plaques. Recent autoimmune evidence fuelled the discussion on psoriasis as an autoimmune skin disorder and has the potential to develop new treatment strategies with protective and therapeutic antigen-targeted methods.

An unbiased high-throughput drug screen reveals a potential therapeutic vulnerability in the most lethal molecular subtype of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related deaths in the United States by 2020, due in part to innate resistance to widely used chemotherapeutic agents and limited knowledge about key molecular factors that drive tumor aggression. We previously reported a novel negative prognostic biomarker, keratin 17 (K17), whose overexpression in cancer results in shortened patient survival. In this study, we aimed to determine the predictive value of K17 and explore the therapeutic vulnerability in K17-expressing PDAC, using an unbiased high-throughput drug screen. Patient-derived data analysis showed that K17 expression correlates with resistance to gemcitabine (Gem). In multiple in vitro and in vivo models of PDAC, spanning human and murine PDAC cells, and orthotopic xenografts, we determined that the expression of K17 results in a more than twofold increase in resistance to Gem and 5-fluorouracil, key components of current standard-of-care chemotherapeutic regimens. Furthermore, through an unbiased drug screen, we discovered that podophyllotoxin (PPT), a microtubule inhibitor, showed significantly higher sensitivity in K17-positive compared to K17-negative PDAC cell lines and animal models. In the clinic, another microtubule inhibitor, paclitaxel (PTX), is used in combination with Gem as a first-line chemotherapeutic regimen for PDAC. Surprisingly, we found that when combined with Gem, PPT, but not PTX, was synergistic in inhibiting the viability of K17-expressing PDAC cells. Importantly, in preclinical models, PPT in combination with Gem effectively decreased tumor growth and enhanced the survival of mice bearing K17-expressing tumors. This provides evidence that PPT and its derivatives could potentially be combined with Gem to enhance treatment efficacy for the ~ 50% of PDACs that express high levels of K17. In summary, we reported that K17 is a novel target for developing a biomarker-based personalized treatment for PDAC.

Overexpression of KRT17 promotes proliferation and invasion of non-small cell lung cancer and indicates poor prognosis

Purpose

Keratin 17 (KRT17) is a 48 KDa type I intermediate filament, which is mainly expressed in epithelial basal cells. KRT17 has been shown to be overexpressed in many malignant tumors and play an important role in the occurrence and development of tumors. Therefore, this study explored the role and underlying mechanism of KRT17 in non-small cell lung cancers (NSCLC).

Methods

KRT17 expression and its correlations with clinicopathological factors were examined in lung cancer tissues by immunohistochemistry. The prognosis value of KRT17 in NSCLCs was retrieved from The Cancer Genome Atlas (TCGA) online databases. The expression level of KRT17 was increased or decreased by KRT17 gene transfection or small RNA interference in lung cancer cells, respectively. Further, proliferation and invasiveness of lung cancer cells were determined by cell proliferation and invasion assays, respectively. Finally, expression levels of proteins related to Wnt signaling pathways and epithelial mesenchymal transition (EMT) were detected by Western blot.

Results

The expression level of KRT17 in NSCLCs was significantly higher than normal lung tissues. High expression of KRT17 predicted poor prognosis of patients with NSCLCs, especially lung adenocarcinomas, and was correlated with poor differentiation and lymphatic metastasis. Overexpression of KRT17 enhanced, while KRT17 knockdown inhibited, the proliferation and invasiveness of lung cancer cells. Overexpression of KRT17 up-regulated β-catenin activity and levels of Wnt target genes, such as cyclin D1, c-Myc, and MMP7. Moreover, KRT17 promoted EMT by up-regulating Vimentin, MMP-9, and Snail expression and down-regulating E-cadherin expression.

Conclusion

Overexpression of KRT17 is common in NSCLCs and indicates poor prognosis. Overexpression of KRT17 enhances the proliferation and invasiveness of NSCLC cells by activating the Wnt signaling pathway and EMT process. KRT17 is a potential indicator of NSCLC progression and poor survival.

The contribution of IL-17 to the development of autoimmunity in psoriasis

Psoriasis is an (auto)immune-mediated disease that manifests as widespread desquamative erythema. The TNF-α/IL-23/IL-17A axis is crucial to its pathogenesis, which is demonstrated by its excellent therapeutic response to biologics that target this axis. There is a strong association between HLA-C*0602 and psoriasis, and researchers have identified autoantigens that are restricted to this major histocompatibility class I molecule. These auto-Ags include LL-37, A disintegrin and metalloprotease domain containing thrombospondin type 1 motif-like 5 (ADAMTSL5), and keratin 17. IL-17A-producing T cells have been identified in T cell populations that are reactive to these auto-Ags. In addition, lipid Ags have surfaced as candidate auto-Ags that activate IL-17A-producing T cells in a CD1a-restricted manner. In this article, we review the candidate auto-Ags that may contribute to the activation of the IL-17A-deviated immune response in psoriasis.

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.

Keratin pearl degradation in oral squamous cell carcinoma: reciprocal roles of neutrophils and macrophages

BACKGROUND

We have reported that neutrophilic infiltration was associated with round-shaped dyskeratosis foci, a kind of keratin pearl, of oral carcinoma in situ and that those inflammatory cells are recruited from intra-epithelially entrapped blood vessels. Based on these lines of evidence, we have formulated a hypothesis that keratin pearls are terminally degraded by neutrophils. To confirm this hypothesis, we investigated immunohistochemically stepwise degradation of keratin pearls in oral squamous cell carcinoma (SCC) to clarify any other type scavenger cells in addition to neutrophils are involved in this particular degradation process.

METHODS

Neutrophils (neutrophil elastase) and macrophage subpopulations (CD68, CD163 and CD204) were immunohistochemically localized in 30 cases of oral SCC with typical round-shaped keratin pearls. SCC cells were revealed by immunohistochemistry for keratin (K) 17, and blood vessels were demonstrated by CD31.

RESULTS

Keratin pearl degradation process was divided into four steps: (i) intact stage: no macrophage infiltration but minimal neutrophils were found in keratin pearls; (ii) neutrophil recruit stage: no macrophage infiltration but focal neutrophilic infiltration within the pearls; (iii) neutrophil predominant stage: dense neutrophil infiltration with minimal macrophages and segregated keratinized cancer cells strongly positive for K17; and (iv) macrophage predominant stage: dense infiltration of CD68-, CD163 (mononuclear)- and CD204 (multinucleated)-positive macrophages engulfing detached keratinized SCC cells.

CONCLUSION

Keratin pearl degradation in oral SCC is strictly regulated by two types of scavenger cells: neutrophils, which perform initial tasks, and macrophages, which reciprocally take over from neutrophils the role to finalize the degradation processes.

Keratin 17: a critical player in the pathogenesis of psoriasis

Keratin 17 (K17) is an intermediate filament protein present in the basal cells of complex epithelia, such as nails, hair follicles, sebaceous glands, and eccrine sweat glands. Studies have shown that it is expressed aberrantly in the suprabasal keratinocytes of psoriatic lesions, compared to in normal epidermis. K17 is also closely associated with the immune system and plays an important role in the pathogenesis of psoriasis. In this review, we present our experimental findings concerning the role of K17 in psoriasis, and compare them to results published in the literature. Our results show that cytokines related to Th17 and IL-22-producing (where Th17 is T helper cells, type 17 and IL is interleukin) CD4(+) T cells, including IL-17A and IL-22, upregulate the expression of K17 in keratinocytes. In addition, K17 stimulates autoreactive T cells and promotes the production of psoriasis-associated cytokines. Our findings lend support to the hypothesis that a K17/T-cell/cytokine autoimmune loop is involved in the pathogenesis of psoriasis. We therefore review the current understanding of the K17 immunoregulation, including its expression and direct/indirect effects on immune responses. Pertinent strategies for the treatment of psoriasis are also discussed.