Keratin 6A (KRT6A) promotes radioresistance, invasion, and metastasis in lung cancer via p53 signaling pathway

BACKGROUND

It is reported that the incidence rate and mortality of lung cancer are very high. Therefore, early diagnosis and identification of specific biomarkers are crucial for the clinical treatment of lung cancer. This study aims to comprehensively investigate the prognostic significance of KRT6A in human lung cancer.

METHODS

The GEO2R online tool was utilized to analyze the differential expression of mRNA between lung carcinoma tissues and radioresistant tissues in the GSE73095 and GSE197236 datasets. DAVID database was used to perform GO and KEGG enrichment analyses on target genes. The Kaplan-Meier plotter tool was used to analyze the impact of key messenger ribonucleic acid on the survival status of lung cancer. In addition, quantitative real-time polymerase chain reaction (qPCR) was used to investigate the impact of key genes on the phenotype of lung cancer cells. After the knockout, we conducted cell migration and CCK-8 experiments to detect their effects on cell proliferation and invasion.

RESULTS

40 differentially expressed genes (DEGs) were chosen from GSE73095 and 118 DEGs were chosen from GSE197236. Kaplan-Meier map analysis showed that the overall cancer survival rate of the high-expression KRT6A group was higher than that of the low-expression group (P < 0.05). Besides, cell experiments have shown that when the KRT6A gene is downregulated, the proliferation and invasion ability of lung cancer cells is weakened.

CONCLUSIONS

Our research concluded that KRT6A may take part in the radioresistance and progression of lung cancer and can be a potential biomarker for lung cancer patients.

KRT6A Inhibits IL-1β-Mediated Pyroptosis of Keratinocytes via Blocking IL-17 Signaling

Keratin 6A (KRT6A) is involved in the pathogenesis of various skin diseases. However, the reports on the roles of KRT6A in atopic dermatitis (AD) are limited. This study aimed to investigate the potentials of KRT6A in AD. mRNA levels were detected by RT-PCR. Cytokine release was determined by ELISA. Protein expression was determined using Western blot. Cell viability was determined by CCK-8. Cytotoxicity was detected by LDH assay. Cell death was determined by TUNEL. The pyroptosis of keratinocytes was detected using flow cytometry. We found that KRT6A was overexpressed in AD patients. Moreover, KRT6A was stimulated after exposed to proinflammatory cytokines. Overexpressed KRT6A suppressed inflammatory response, while KRT6A knockdown exerted the opposite effects. Overexpressed KRT6A suppressed inflammation-induced pyroptosis of keratinocytes. Additionally, KRT6A negatively regulated interleukin-17a (IL-17a) expression, blocking IL-17 signaling. IL-17a overexpression antagonized the effects of KRT6A and promoted pyroptosis of keratinocytes. In conclusion, KRT6A exerted protective functions in AD via regulating IL-17 signaling. This KRT6A/IL-17 may be a novel target for AD.

The expression pattern of cytokeratin 6a in epithelial cells of different origin in dermo-epidermal skin substitutes in vivo

Keratinocytes are the predominant cell type of skin epidermis. Through the programmed process of differentiation, they form a cornified envelope that provides a physical protective barrier against harmful external environment. Keratins are major structural proteins of keratinocytes that together with actin filaments and microtubules form the cytoskeleton of these cells. In this study, we examined the expression pattern and distribution of cytokeratin 6a (CK6a) in healthy human skin samples of different body locations, in fetal and scar skin samples, as well as in dermo-epidermal skin substitutes (DESSs). We observed that CK6a expression is significantly upregulated in fetal skin and scar tissue as well as in skin grafts after short-term transplantation. Importantly, the abundance of CK6a corresponds directly to the expression pattern of wound healing marker CK16. We postulate that CK6a is a useful marker to accurately evaluate the homeostatic state of DESSs.

Bacterial Pyocyanin Inducible Keratin 6A Accelerates Closure of Epithelial Defect under Conditions of Mitochondrial Dysfunction

Repair of epithelial defect is complicated by infection and related metabolites. Pyocyanin (PYO) is one such metabolite that is secreted during Pseudomonas aeruginosa infection. Keratinocyte (KC) migration is required for the closure of skin epithelial defects. This work sought to understand PYO-KC interaction and its significance in tissue repair. Stable Isotope Labeling by Amino acids in Cell culture proteomics identified mitochondrial dysfunction as the top pathway responsive to PYO exposure in human KCs. Consistently, functional studies showed mitochondrial stress, depletion of reducing equivalents, and adenosine triphosphate. Strikingly, despite all stated earlier, PYO markedly accelerated KC migration. Investigation of underlying mechanisms revealed, to our knowledge, a previously unreported function of keratin 6A in KCs. Keratin 6A was PYO inducible and accelerated closure of epithelial defect. Acceleration of closure was associated with poor quality healing, including compromised expression of apical junction proteins. This work recognizes keratin 6A for its role in enhancing KC migration under conditions of threat posed by PYO. Qualitatively deficient junctional proteins under conditions of defensive acceleration of KC migration explain why an infected wound close with deficient skin barrier function as previously reported.

KRT6A expedites bladder cancer progression, regulated by miR-31-5p

Bladder cancer is one of the most severe life-threatening illnesses worldwide. To contribute to a solution to this public health issue, here, we sought to identify a novel biomarker for the early diagnosis of bladder tumors. We conducted RNA sequence analysis utilizing samples from tumorous tissue and adjacent healthy tissue in bladder cancer patients and found that KRT6A was upregulated in bladder tumor tissues, suggesting that it might be a candidate for involvement in bladder tumorigenesis. Accordingly, we performed a series of experiments to further verify the role of KRT6A in bladder tumor progression. Our results revealed that KRT6A promoted bladder tumor cell viability, proliferation, and adhesion, while diminishing bladder tumor cell apoptosis. We also focused on the role of epigenetics in bladder tumors and verified that KRT6A was a miR-31-5p target gene, and its positive effect on bladder tumor progression was relieved by miR-31-5p. Overall, this study sheds new light regarding a novel oncogenic regulatory axis, KRT6A/miR-31-5p, which is related to bladder tumor growth.

Utility of D2-40, Cytokeratin 5/6, and High-Molecular-weight Cytokeratin (Clone 34βE12) in Distinguishing Intraductal Spread of Urothelial Carcinoma From Prostatic Stromal Invasion

Intraductal spread of urothelial carcinoma (UC) is not an uncommon finding in bladder cancer that requires appropriate clinical management. The presence of prostatic stromal invasion in non-muscle-invasive bladder cancer upstages the disease, necessitating cisplatin-based neoadjuvant chemotherapy and subsequent cystroprostatectomy. However, the identification of prostatic stromal invasion can be challenging, especially in biopsy and transurethral resection specimens. We assess the utility of D2-40, CK5/6, and high-molecular-weight cytokeratin (HMWCK) immunohistochemistry as an ancillary tool to differentiate prostatic stromal invasion from intraductal UC spread. We reviewed 13 cystoprostatectomies performed for UC with prostatic involvement. The presence of stromal invasion was histologically determined by the presence of circumferential retraction artifact, paradoxical differentiation, complex architecture, and desmoplastic reaction. The areas of interest were subsequently stained with D2-40, CK5/6, and HMWCK (clone 34βE12). Four bladder biopsies were used as a control to assess labeling in the benign urothelium. Nine cases had histologic evidence of prostatic stromal invasion (4 transmurally through bladder wall). D2-40 highlighted basal cells in all benign prostatic ducts and was consistently negative in UC, benign urothelium, prostatic adenocarcinoma, and benign luminal prostatic epithelium. D2-40 and CK5/6 performed similarly for intraductal UC, labeling only the basal cell layer with the exception of 1 case with squamous differentiation where CK5/6 exhibited full thickness staining. HMWCK diffusely stained 9 of 10 intraductal UCs without squamous differentiation and 1 intraductal UC with squamous differentiation. All 8 cases of invasive UC without squamous differentiation were negative for D2-40. Seven of these cases had focal CK5/6 and diffuse HMWCK staining. In 1 case of invasive UC with squamous differentiation, all stains were positive. D2-40 is expressed in prostatic basal cells, but it is not expressed in the benign or neoplastic urothelium. D2-40 and CK5/6 effectively highlight the intraductal spread of UC. While invasive UC is negative for D2-40, CK5/6 is usually patchy and localized to the periphery of the tumor nests. HMWCK often demonstrates diffuse staining in both scenarios. However, these stains do not perform well in cases of UC with squamous differentiation. Thus, D2-40 can be used as an ancillary tool to rule out prostatic stromal invasion.

Alteration of tumor-associated macrophage subtypes mediated by KRT6A in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is severely affecting the health and lives of patients. Clarifying the composition and regulatory factors of tumor immune microenvironment (TIME) is helpful for the treatment of PDAC. We analyzed the unique TIMEs and gene expression patterns between PDAC and adjacent normal tissue (ANT) using Gene Expression Omnibus (GEO) to find new immunotherapy targets. The Cancer Genome Atlas (TCGA) datasets were used to elucidate the possible mechanism of which tumor-associated macrophages (TAMs) changed in PDAC. We found that the composition of TAMs subtypes, including M0, M1, and M2, was different between PDAC and ANT, which was validated in recently published single-cell RNA-seq data. Many immune cells interacted with each other to affect the TIME. There were many DEGs enriched in some pathways that could potentially change the immune cell composition. KRT6A was found to be a DEG between PDAC and ANT that overlapped with DEGs between the M0-high group and the M0-low group in TCGA datasets, and it might alter and regulate TAMs via a collection of genes including COL5A2, COL1A2, MIR3606, SPARC, and COL6A3. TAMs, which could be a target of immunotherapy, might be influenced by genes through KRT6A and indicate an undesirable prognosis in PDAC.

Trafficking and secretion of keratin 75 by ameloblasts in vivo

A highly specialized cytoskeletal protein, keratin 75 (K75), expressed primarily in hair follicles, nail beds, and lingual papillae, was recently discovered in dental enamel, the most highly mineralized hard tissue in the human body. Among many questions this discovery poses, the fundamental question regarding the trafficking and secretion of this protein, which lacks a signal peptide, is of an utmost importance. Here, we present evidence that K75 is expressed during the secretory stage of enamel formation and is present in the forming enamel matrix. We further show that K75 is secreted together with major enamel matrix proteins amelogenin and ameloblastin, and it was detected in Golgi and the endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC) but not in rough ER (rER). Inhibition of ER-Golgi transport by brefeldin A did not affect the association of K75 with Golgi, whereas ameloblastin accumulated in rER, and its transport from rER into Golgi was disrupted. Together, these results indicate that K75, a cytosolic protein lacking a signal sequence, is secreted into the forming enamel matrix utilizing portions of the conventional ER-Golgi secretory pathway. To the best of our knowledge, this is the first study providing insights into mechanisms of keratin secretion.

Keratin 6, 16 and 17-Critical Barrier Alarmin Molecules in Skin Wounds and Psoriasis

Located at the skin surface, keratinocytes (KCs) are constantly exposed to external stimuli and are the first responders to invading pathogens and injury. Upon skin injury, activated KCs secrete an array of alarmin molecules, providing a rapid and specific innate immune response against danger signals. However, dysregulation of the innate immune response of KCs may lead to uncontrolled inflammation and psoriasis pathogenesis. Keratins (KRT) are the major structural intermediate filament proteins in KCs and are expressed in a highly specific pattern at different differentiation stages of KCs. While KRT14-KRT5 is restricted to basal proliferative KCs, and KRT10-KRT1 is restricted to suprabasal differentiated KCs in normal skin epidermis, the wound proximal KCs downregulate KRT10-K1 and upregulate KRT16/KRT17-KRT6 upon skin injury. Recent studies have recognized KRT6/16/17 as key early barrier alarmins and upregulation of these keratins alters proliferation, cell adhesion, migration and inflammatory features of KCs, contributing to hyperproliferation and innate immune activation of KCs in response to an epidermal barrier breach, followed by the autoimmune activation of T cells that drives psoriasis. Here, we have reviewed how keratins are dysregulated during skin injury, their roles in wound repairs and in initiating the innate immune system and the subsequent autoimmune amplification that arises in psoriasis.

Keratin 6, induced by chronic cisplatin exposure, confers chemoresistance in human gastric carcinoma cells

Currently, various types of keratins have been reported to be highly expressed in cancer cells and to be associated with a malignant phenotype. In the present study, it was found that expression levels of keratin 6 (K6), keratin 16 (K16), and keratin 17 (K17) were highly elevated in SNU601 cells resistant to cisplatin (SNU601‑cis2 and SNU601‑cis10), but not in the parental SNU601 cells as confirmed by quantitative PCR, immunoblotting, and immunofluorescence assays. K6 is a type II keratin and is known to form a keratin filament in conjugation with type I keratin, K16 or K17. Thus, we attempted to understand the role of the overexpression of K6/K16 or K6/K17 keratin filaments by regulating the expression of K6. Silencing of K6 by siRNA in SNU601‑cis2 cells promoted oxaliplatin‑induced apoptosis in the resistant cells as shown by increased apoptotic body formation, caspase‑8 and caspase‑3 cleavage, and cytochrome c release. In addition, induction of K6 levels in wild‑type SNU601 cells, by transfection with pCMV6‑K6A and pCMV6‑K6B overexpression vectors, resulted in decreased apoptosis in response to cisplatin and L‑OHP. Platinum drugs, such as oxaliplatin, were shown to induce the extrinsic apoptotic pathway by inducing lipid raft formation and death receptor recruitment into lipid rafts. However, in the resistant cells, the oxaliplatin‑triggered extrinsic apoptotic pathway appeared to be suppressed by decreased lipid raft formation, and recruitment of death receptor 5 and FADD into lipid rafts. Therefore, the increase in the levels of the K6 filament may be associated with the regulation of lipid raft formation and may contribute, at least in part, to resistance to anticancer drugs.

[Expression of TTF-1, NapsinA, P63, CK5/6 in Lung Cancer and Its Diagnostic Values for Histological Classification]

OBJECTIVES

To investigate the expressions of thyroid transcription factor-1(TTF-1), NapsinA, P63 and CK5/6 in lung cancer tissues and their diagnostic value for histological classification.

METHODS

The protein expression in a total of 964 lung cancer samples was detected by immunohistochemistry, of which 929 cases for TTF-1, 113 cases for NapsinA, 282 cases for P63, and 277 for CK5/6, respectively. The correlations between the protein expressions of the four markers and clinicopathological features in lung cancer patients were analyzed. The area under the curves (AUCs) of ROC curves, sensitivity and specificity were calculated to determine the diagnostic values for the four markers.

RESULTS

There were 552 cases of lung adenocarcinoma (ADC), 146 cases of lung squamous cell carcinoma (SCC), 253 cases of small cell carcinoma (SCLC), and 13 cases of large cell carcinoma (LCC). The median age was 56 years old, and 63.4% was male. The positive expression rates of TTF-1, NapsinA, P63, and CK5/6 were 76.3% (709/929), 67.3% (76/113) , 47.2% (133/282) and 34.7% (96/277), respectively. The positive expression rates of TTF-1 and NapsinA were higher in lung ADC, and the sensitivity and specificity of TTF-1 in the diagnosis of ADC were 81.15% and 30.41% respectively, those of NapsinA were 82.05% and 65.71% respectively. The AUCs for TTF-1 and NapsinA were 0.557 8 (P=0.002 6, 95%CI:0.520 0-0.595 6) and 0.738 8 (P<0.000 1, 95%CI:0.633 4-0.844 2) respectively. The positive expression rates of P63 and CK5/6 were significantly higher in lung SCC, and their sensitivities to diagnose SCC were 80.68% and 81.25%, with specificity 68.04% and 84.26% respectively. TheAUCsfor P63 and CK5/6 were 0.743 6 (P<0.000 1, 95%CI:0.681 9-0.805 3) and 0.827 6 (P<0.000 1, 95%CI:0.770 0-0.885 2) respectively. Logistic regression model with small sample (44 cases, ADC or SCC) showed that NapsinA was an independent factor to distinguish ADC and SCC (partial regression coefficient=2.826, P=0.022), while the other three markers showed no statistical significance (P>0.05).

CONCLUSIONS

TTF-1 and NapsinA can be used as prognositic markers for lung ADC. P63 and CK5/6 can be used as prognostic markers for lung SCC. NapsinA may be used to distinguish ADC and SCC.

Rhomboid family member 2 regulates cytoskeletal stress-associated Keratin 16

Keratin 16 (K16) is a cytoskeletal scaffolding protein highly expressed at pressure-bearing sites of the mammalian footpad. It can be induced in hyperproliferative states such as wound healing, inflammation and cancer. Here we show that the inactive rhomboid protease RHBDF2 (iRHOM2) regulates thickening of the footpad epidermis through its interaction with K16. K16 expression is absent in the thinned footpads of irhom2-/- mice compared with irhom2+/+mice, due to reduced keratinocyte proliferation. Gain-of-function mutations in iRHOM2 underlie Tylosis with oesophageal cancer (TOC), characterized by palmoplantar thickening, upregulate K16 with robust downregulation of its type II keratin binding partner, K6. By orchestrating the remodelling and turnover of K16, and uncoupling it from K6, iRHOM2 regulates the epithelial response to physical stress. These findings contribute to our understanding of the molecular mechanisms underlying hyperproliferation of the palmoplantar epidermis in both physiological and disease states, and how this 'stress' keratin is regulated.

Proteomic profiling reveals candidate markers for arsenic-induced skin keratosis

Proteomics technology is an attractive biomarker candidate discovery tool that can be applied to study large sets of biological molecules. To identify novel biomarkers and molecular targets in arsenic-induced skin lesions, we have determined the protein profile of arsenic-affected human epidermal stratum corneum by shotgun proteomics. Samples of palm and foot sole from healthy subjects were analyzed, demonstrating similar protein patterns in palm and sole. Samples were collected from the palms of subjects with arsenic keratosis (lesional and adjacent non-lesional samples) and arsenic-exposed subjects without lesions (normal). Samples from non-exposed healthy individuals served as controls. We found that three proteins in arsenic-exposed lesional epidermis were consistently distinguishably expressed from the unaffected epidermis. One of these proteins, the cadherin-like transmembrane glycoprotein, desmoglein 1 (DSG1) was suppressed. Down-regulation of DSG1 may lead to reduced cell-cell adhesion, resulting in abnormal epidermal differentiation. The expression of keratin 6c (KRT6C) and fatty acid binding protein 5 (FABP5) were significantly increased. FABP5 is an intracellular lipid chaperone that plays an essential role in fatty acid metabolism in human skin. This raises a possibility that overexpression of FABP5 may affect the proliferation or differentiation of keratinocytes by altering lipid metabolism. KRT6C is a constituent of the cytoskeleton that maintains epidermal integrity and cohesion. Abnormal expression of KRT6C may affect its structural role in the epidermis. Our findings suggest an important approach for future studies of arsenic-mediated toxicity and skin cancer, where certain proteins may represent useful biomarkers of early diagnoses in high-risk populations and hopefully new treatment targets. Further studies are required to understand the biological role of these markers in skin pathogenesis from arsenic exposure.

[p16INK4a protein is a specific molecular biomarker of breast cancer]

OBJECTIVE

To investigate the expression of p16INK4a protein in breast cancer and analyze its clinical significance.

METHODS

A total of 132 surgical specimens of primary breast cancer obtained between 2014 and 2015 were examined for expressions of ER, PR, CK5/6, Her-2 and p16INK4a proteins using immunohistochemistry.

RESULTS

The breast cancer samples were classified into 5 molecular subtypes, namely Luminal A (58 cases), Luminal B (32 cases), Her-2-positive (21 cases), basal-like (12 cases) and normal-like (9 cases) types. p16INK4a expression was negative in 7/132 (5.30%) cases, weakly positive in 15/132 (11.36%) cases, positive in 40/132 (30.30%) cases, and strongly positive in 70/132 (53.03%) cases. When categorizing negative and weakly positive cases into negative group and the positive and strongly positive cases into positive group, the total negative and positive expression rates of p16INK4a were 16.67% (22/132) and 83.33% (110/132) in the carcinoma tissues. Statistical analysis showed the expression intensity of p16INK4a differed significantly between the age groups (P<0.05) but was not significantly correlated with ER, PR, Her-2, molecular subtypes or metastasis of the tumors.

CONCLUSION

The compensatory high expression of p16INK4a is the main mechanism of cell cycle deregulation in invasive breast cancer and can be an important specific molecular marker for invasive breast cancer.

IMMUNOHISTOCHEMICAL DIFFERENTIATION OF TRIPLE NEGATIVE BREAST CANCER

Based on immunohistochemical staining for the basal markers cytokeratin 5/6 (CK 5/6), cytokeratin 14 (CK 14) and P-cadherin, triple negative tumors (TNT) are divided into two groups: 1) basal-like (BL) positive for one or all three markers; and 2) non basal-like (NBL) negative for all three markers. Even though the different origin of the cells of these two types of tumors implies different biological properties, they had been treated as one entity until recently. This paper analyzes TNT collected from 150 patients and distributed into two groups according to the results of immunohistochemical analysis, i.e. BL 116 (77.3%) and NBL 34 (22.67%). In this study, CK 5/6, CK 14 and P-cadherin were used as markers for identifying BL tumors. The immunohistochemical reaction was positive for CK 5/6 in 37%, for CK 14 in 50.86% and for P-cadherin in 68.34% of cases. The subclassification of triple negative breast cancer using the basal markers CK 5/6, CK 14 and P-cadherin has enabled identification of BL and NBL breast cancers in a proportion that is in line with the only accurate analysis of TNT gene expression. Using the mentioned combination of markers in daily practice is easy to perform and economically affordable.

Heterogeneity of luminal breast cancer characterised by immunohistochemical expression of basal markers

BACKGROUND

Luminal A breast cancer defined as hormone receptor positive and human epidermal growth factor receptor 2 (HER2) negative is known to be heterogeneous. Previous study showed that luminal A tumours with the expression of basal markers ((cytokeratin (CK) 5 or CK5/6) or epidermal growth factor receptor (EGFR)) were associated with poorer prognosis compared with those that stained negative for basal markers. Prompted by this study, we assessed whether tumour characteristics and risk factors differed by basal marker status within luminal A tumours.

METHODS

We pooled 5040 luminal A cases defined by immunohistochemistry (4490 basal-negative ((CK5 (or CK5/6))- and EGFR-) and 550 basal-positive ((CK5 (or CK5/6+)) or EGFR+)) from eight studies participating in the Breast Cancer Association Consortium. Case-case comparison was performed using unconditional logistic regression.

RESULTS

Tumour characteristics and risk factors did not vary significantly by the expression of basal markers, although results suggested that basal-positive luminal tumours tended to be smaller and node negative, and were more common in women with a positive family history and lower body mass index.

CONCLUSIONS

Most established breast cancer risk factors were similar in basal-positive and basal-negative luminal A tumours. The non-significant but suggestive differences in tumour features and family history warrant further investigations.

[Value of CK5/6, CK14, ER and PR detection in differential diagnosis of intraductal proliferative lesions of the breast]

OBJECTIVE

To investigate the expression of high-molecular-weight keratins CK5/6, CK14, estrogen receptor (ER) and progesterone receptor (PR) in differential diagnosis of simple ductal hyperplasia (UDH), atypical ductal hyperplasia (ADH) and low-grade ductal carcinoma in situ (low-grade DCIS) .

METHODS

The clinicopathological data of twenty cases of atypical ductal epithelial hyperplasia (ADH) with focal cancerization changed into low-grade DCIS diagnosed at Tianjin Medical University Cancer Institute and Hospital between January 2013 and February 2014 were reviewed and analyzed. The expressions of CK5/6, CK14, ER and PR were detected by immunohistochemistry.

RESULTS

Positive expressions of CK5/6 and CK14 were seen in UDH showing a mosaic pattern, while negative expression in ADH and low-grade DCIS. In addition, CK5/6 and CK14 were positively expressed in the myoepithelial cells of UDH, ADH and low-grade DCIS. Positive expressions of ER and PR were observed in UDH, ADH and low-grade DCIS. But they presented diffuse and homogeneous strong positive expression in ADH and variable positive expression in UDH.

CONCLUSION

In the intraductal proliferative lesions of the breast, the use of combined detection of the expression of CK5/6, CK14, ER and PR is of practical significance in the differential diagnosis of UDH, ADH and low-grade DCIS.

[Expression of p63, p40 and CK5/6 in small cell lung cancer]

OBJECTIVE

To study the expression of squamous cell markers p63, p40 and CK5/6 in small cell carcinoma of lung (SCLC).

METHODS

Immunohistochemical study for squamous cell markers (p63, p40 and CK5/6), neuroendocrine markers (chromogranin A, synaptophysin and CD56) and TTF1 was carried out in 283 cases of SCLC. The diagnostic value of these markers was evaluated.

RESULTS

The expression rate of p63, p40 and CK5/6 were 20.7% (54/261), 7.9% (5/63) and 0.5% (1/221), respectively in the cases of SCLC studied. Amongst the squamous cell markers, CK5/6 had the lowest rate of positivity (P < 0.01). On the other hand, chromogranin A, synaptophysin and CD56 were positive in 61.8% (170/275), 85.5% (242/283) and 89.2% (248/278), respectively. The positivity rate for chromogranin A was lower than that for synaptophysin and CD56 (P < 0.01). TTF1 was expressed in 77.2% (217/281).

CONCLUSIONS

p63 and p40 are expressed in a subset of SCLC. In contrast, CK5/6 is rarely positive in SCLC. An immunohistochemical panel of CK5/6, synaptophysin and CD56 is recommended for differential diagnosis of SCLC.

KRT6 interacting with notch1 contributes to progression of renal cell carcinoma, and aliskiren inhibits renal carcinoma cell lines proliferation in vitro

Notch signaling is a conserved and widely expressed signaling pathway, which mediates various physiological processes including tumorigenesis. This study aims to explore the potential role and mechanism of notch1 interacting with KRT6B in the progression of RCC. The results indicated that the mRNA and protein expression of notch1 and KRT6 were significantly increased in tumor tissues, and highly positive correlation existed between notch1 and KRT6. Moreover, the patients with high notch1 expression had a significantly poorer prognosis than those of low expression patients. In vitro, KRT6 loss-of-function could inhibit the expression of notch1 and induce renal carcinoma cell death. Eventually, we found that renin inhibitor, aliskiren, could inhibit cell proliferation and decrease the expression of notch1 and KRT6 as well as regulate apoptosis-related protein expression in 786-O and ACHN renal carcinoma cell lines. These results suggested that the upregulation of notch1 and KRT6B might be involved in the development, progression and prognosis of human RCC, and aliskiren could suppress renal carcinoma cell proliferation, at least partially, through downregulation the expression of notch1 and KRT6.

The active tamoxifen metabolite endoxifen (4OHNDtam) strongly down-regulates cytokeratin 6 (CK6) in MCF-7 breast cancer cells

Introduction

Tamoxifen is an anti-estrogen drug used in treatment of Estrogen Receptor (ER) positive breast cancer. Effects and side effects of tamoxifen is the sum of tamoxifen and all its metabolites. 4-Hydroxytamoxifen (4OHtam) and 4-hydroxy-N-demethyltamoxifen (4OHNDtam, endoxifen) both have ER affinity exceeding that of the parent drug tamoxifen. 4OHNDtam is considered the main active metabolite of tamoxifen. Ndesmethyltamoxifen (NDtam) is the major tamoxifen metabolite. It has low affinity to the ER and is not believed to influence tumor growth. However, NDtam might mediate adverse effects of tamoxifen treatment. In this study we investigated the gene regulatory effects of the three metabolites of tamoxifen in MCF-7 breast cancer cells.

Material and Methods

Using concentrations that mimic the clinical situation we examined effects of 4OHtam, 4OHNDtam and NDtam on global gene expression in 17β-estradiol (E₂) treated MCF-7 cells. Transcriptomic responses were assessed by correspondence analysis, differential expression, gene ontology analysis and quantitative real time PCR (Q-rt-PCR). E₂ deprivation and knockdown of Steroid Receptor Coactivator-3 (SRC-3)/Amplified in Breast Cancer 1 (AIB1) mRNA in MCF-7 cells were performed to further characterize specific effects on gene expression.

Results

4OHNDtam and 4OHtam caused major changes in gene expression compared to treatment with E₂ alone, with a stronger effect of 4OHNDtam. NDtam had nearly no effect on the global gene expression profile. Treatment of MCF-7 cells with 4OHNDtam led to a strong down-regulation of the CytoKeratin 6 isoforms (KRT6A, KRT6B and KRT6C). The CytoKeratin 6 mRNAs were also down-regulated in MCF-7 cells after E₂ deprivation and after SRC-3/AIB1 knockdown.

Conclusion

Using concentrations that mimic the clinical situation we report global gene expression changes that were most pronounced with 4OHNDtam and minimal with NDtam. Genes encoding CytoKeratin 6, were highly down-regulated by 4OHNDtam, as well as after E₂ deprivation and knockdown of SRC-3/AIB1, indicating an estrogen receptor-dependent regulation.

Cleavage of host cytokeratin-6 by lysine-specific gingipain induces gingival inflammation in periodontitis patients

BACKGROUND/PURPOSE

Lysine-specific gingipain (Kgp) is a virulence factor secreted from Porphyromonas gingivalis (P. gingivalis), a major etiological bacterium of periodontal disease. Keratin intermediate filaments maintain the structural integrity of gingival epithelial cells, but are targeted by Kgp to produce a novel cytokeratin 6 fragment (K6F). We investigated the release of K6F and its induction of cytokine secretion.

METHODS

K6F present in the gingival crevicular fluid of periodontal disease patients and in gingipain-treated rat gingival epithelial cell culture supernatants was measured by matrix-assisted laser desorption/ionization time-of-flight mass spectrometer-based rapid quantitative peptide analysis using BLOTCHIP. K6F in gingival tissues was immunostained, and cytokeratin 6 protein was analyzed by immunofluorescence staining and flow cytometry. Activation of MAPK in gingival epithelial cells was evaluated by immunoblotting. ELISA was used to measure K6F and the cytokines release induced by K6F. Human gingival fibroblast migration was assessed using a Matrigel invasion chamber assay.

RESULTS

We identified K6F, corresponding to the C-terminus region of human cytokeratin 6 (amino acids 359-378), in the gingival crevicular fluid of periodontal disease patients and in the supernatant from gingival epithelial cells cultured with Kgp. K6F antigen was distributed from the basal to the spinous epithelial layers in gingivae from periodontal disease patients. Cytokeratin 6 on gingival epithelial cells was degraded by Kgp, but not by Arg-gingipain, P. gingivalis lipopolysaccharide or Actinobacillus actinomycetemcomitans lipopolysaccharide. K6F, but not a scrambled K6F peptide, induced human gingival fibroblast migration and secretion of interleukin (IL)-6, IL-8 and monocyte chemoattractant protein-1. These effects of K6F were mediated by activation of p38 MAPK and Jun N-terminal kinase, but not p42/44 MAPK or p-Akt.

CONCLUSION

Kgp degrades gingival epithelial cell cytokeratin 6 to K6F that, on release, induces invasion and cytokine secretion by human gingival fibroblasts. Thus, Kgp may contribute to the development of periodontal disease.

Krt6a-positive mammary epithelial progenitors are not at increased vulnerability to tumorigenesis initiated by ErbB2

While most breast cancers are thought to arise from the luminal layer of the breast tissue, it remains unclear which specific cells in the luminal layer are the cells of origin of breast cancer. We have previously reported that WAP-positive luminal epithelial cells are at increased susceptibility to tumor initiation by ErbB2 compared to the bulk population, while the mammary cells with canonical Wnt signaling activity fail to evolve into tumors upon ErbB2 activation. Here, we used retrovirus to introduce ErbB2 into the Krt6a-positive mammary progenitor subset of the luminal epithelium and, for comparison, into the mammary luminal epithelium indiscriminately. Tumors developed from both groups of cells with a similar latency. These data indicate that the Krt6a-positive subset of mammary epithelial cells can be induced to form cancer by ErbB2 but it is not more susceptible to tumorigenesis initiated by ErbB2 than the bulk population of the luminal epithelium.

Expression of thrombomodulin, calretinin, cytokeratin 5/6, D2-40 and WT-1 in a series of primary carcinomas of the lung: an immunohistochemical study in comparison with epithelioid pleural mesothelioma

AIMS AND BACKGROUND

A number of immunohistochemical markers have been suggested as useful in the positive diagnosis of epithelioid mesothelioma. The most widely used mesothelioma markers are thrombomodulin, calretinin, cytokeratin 5/6, D2-40 and WT-1. Numerous investigations have demonstrated their variable sensitivity and specificity in differentiating epithelioid mesothelioma from lung adenocarcinoma. However, data on the expression of these markers in other types of lung carcinomas are very limited. We evaluated the expression of these markers in a series of 172 primary carcinomas of the lung and in 75 epithelioid pleural mesotheliomas.

RESULTS

Thrombomodulin expression was found in squamous cell carcinomas (71%), small cell lung carcinomas (11%), adenocarcinomas (4%), large cell carcinomas (50%), large cell neuroendocrine carcinomas (25%) and in sarcomatoid carcinomas (10%). Calretinin expression was common in small cell lung carcinomas (44%) and large cell neuroendocrine carcinomas (25%), less common in squamous cell carcinomas (20%), rare and focal in adenocarcinomas (4%) and sarcomatoid carcinomas (10%). Cytokeratin 5/6 was expressed in most of the squamous cell carcinomas (94.5%). Immunoreactivity was also found in large cell carcinomas (50%), sarcomatoid carcinomas (30%) and rarely in adenocarcinomas (4%). D2-40 was consistently expressed in squamous cell carcinomas (42%). Focal immunoreactivity was found in adenocarcinomas (3%). WT-1 was focally present in one (2%) squamous cell carcinoma.

CONCLUSIONS

These results indicate that some of the most commonly used mesothelioma markers may react with different types of primary lung carcinomas. These data should be taken into consideration especially when dealing with small biopsy fragments and poorly differentiated tumors.

Androgenic pathways in the progression of triple-negative breast carcinoma: a comparison between aggressive and non-aggressive subtypes

One of the active intracellular pathways/networks in triple-negative breast carcinoma (TNBC) is that of the androgen receptor (AR). In this study, we examined AR and androgen-metabolising enzyme immunoreactivity in subcategories of TNBC to further elucidate the roles of androgenic pathways in TNBC. We utilised formalin-fixed paraffin-embedded breast cancer samples from ductal carcinoma in situ (DCIS) and invasive ductal carcinoma patient cohorts. We then used immunohistochemistry to classify these samples into basal-like and non-basal samples and to assess interactions between AR, androgen-metabolising enzymes and proliferation. To further substantiate our hypothesis and provide mechanistic insights, we also looked at the expression and regulation of these factors in publically available microarray data and in a panel of TNBC AR-positive cell lines. DCIS was associated with higher levels of AR and enzymes (p < 0.02), although a similar difference was not noticed in basal and non-basal samples. AR and enzymes were correlated in all states. In TNBC cell lines (MDA-MD-453, MFM-223 and SUM185-PE), we found that DHT treatment up-regulated 5αR1 and 17βHSD5 suggesting a mechanistic explanation for the correlations observed in the histological samples. Publicly available microarray data in TNBC cases suggested similar patterns to those observed in histological samples. In the majority of settings, including publically available microarray data, an inverse association between AR and proliferation was detected. These findings suggest that decreases in AR and androgen-metabolising enzymes may be involved in the increased biological aggressiveness in TNBC development.

Small cell type neuroendocrine carcinoma colliding with squamous cell carcinoma at esophagus

Collision tumor is an extremely rare tumor which defined as the concrescence of two distinct primaries neoplasms. We report here a case of collision tumor at lower third esophagus composed of small cell type neuroendocrine carcinoma (NEC), which is an very rare, highly aggressive and poorly prognostic carcinoma and squamous cell carcinoma (SqCC). In our case, pathologically, the small cell carcinoma display the characteristic of small, round, ovoid or spindle-shaped tumor cells with scant cytoplasm, which colliding with a moderately differentiated squamous cell carcinoma. Immunohistochemical staining demonstrated positive activities for CD56, synaptophysin, 34βE12, CK 5/6, ki-67 (70%-80%), but negative for CD99, chromogranin A, and TTF-1. Accurate diagnosis was made base on these findings.

[Clinicopathologic features of cystic hypersecretory lesion of the breast]

OBJECTIVE

To study the clinicopathologic features, immunophenotype and differential diagnosis of cystic hypersecretory lesion (CHL) of the breast.

METHODS

Clinicopathologic and follow-up data of six cases of breast CHL in 2010-2013 were collected and reviewed.Immunohistochemical and mucinous staining was performed.

RESULTS

All six patients were female, age ranged from 37 to 71 years (average 49.3 years). Three cases were cystic hypersecretory hyperplasia (CHH), the other three cases were cystic hypersecretory carcinoma (CHC). Clinically the lesions presented as either breast mass or mammographic calcification.Grossly, the cystic hypersecretory lesions were poorly circumscribed, with multiple colloid containing cysts on the cut surface. Microscopically, the remarkable feature was numerous enlarged cysts which contained densely eosinophilic homogeneous secretion similar to the colloid seen in thyroid follicles, and calcification was seen in the cyst in one case. The secretion was D-PAS and mucicarmine positive. The lining epithelium of the cysts was uniformly flat, cuboid or columnar, and arranged in a monolayer. The cells may be arranged in turfs, solid or micropapillary patterns in CHH.In cases with dysplasia, the epithelium showed cytological and structural atypia, but the usual morphology of atypical dutal hyperplasia such as arcades, rigid bridges or cribriform pattern was less common. The three CHC included two invasive ductal carcinomas (IDC) and one ductal carcinoma in situ (DCIS).In CHL, there was immunoreactivity to S-100 protein, CK5/6 and CK14.Of the three CHCs, ER and PR were expressed in only one IDC.No HER2 expression was identified in the two invasive CHCs.One patient was lost to follow-up, and the rest were uneventful at 18 months.

CONCLUSIONS

CHL of the breast is a rare pathological entity. Multiple colloid-filled cysts is a unique histological feature. The epithelium of CHL may show usual hyperplasia, dysplasia or carcinoma.

Thyrotropin-releasing hormone (TRH) promotes wound re-epithelialisation in frog and human skin

There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis) skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH) as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression). Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters.

Histopathological, histogenetic, and immunohistochemical analysis of epidermoid cyst of spleen

Splenic cysts are encountered not uncommonly, but large cysts occupying a significant portion of the spleen are extremely rare. We report a case of a young female patient presenting with a large epidermoid cyst involving the majority of the spleen. The patient was involved in a motor vehicle accident during which she sustained multiple rib fractures and traumatic internal organ injuries. She subsequently underwent exploratory laparotomy and splenectomy for grade III splenic lacerations. Incidentally, a 13.3 cm in greatest dimension splenic cyst replacing the majority of the splenic parenchyma was identified. Grossly, the inner lining of cyst was gray-white, smooth, and glistening. Histologically, the thick fibrous cyst wall was composed of stratified squamous epithelium, scattered foci of which were denuded. A panel of properly-controlled immunohistochemical stains was performed and showed the squamous epithelium to be strongly and diffusely immunoreactive with carcinoembryonic antigen (CEA), CA 19-9, and cytokeratin 5/6, focally immunoreactive with HBME-1, and negative for calretinin. The histomorphological features and immunohistochemical staining pattern were consistent with a diagnosis of an epidermoid cyst of the spleen.

[Invasive lobular carcinoma of basal-like subtype of breast: a clinicopathologic analysis]

OBJECTIVE

To investigate the clinicopathologic features, clinical progress and prognosis of the basal-like subtype of invasive lobular carcinoma (ILC) of the breast.

METHODS

Four cases of ILC were analyzed by detailed histopathologic observation and immunohistochemical staining for E-cadherin, p120 catenin, ER, PR, HER2, CK5/6, EGFR, p63, p53, Ki-67 using MaxVision method. The follow-up and clinical data were analyzed.

RESULTS

Morphologically, one case was mixed ILC and three cases were pleomorphic ILC. The tumor cells were negative for E-cadherin except one case with focal membrane positivity, and all showed p120 catenin cytoplasmic positivity except one case with focal membrane positivity. All cases were negative for ER, PR and HER2 (triple negative), and positive for EGFR and CK5/6. Two cases were positive for p63. The cases were partly and weakly positive for p53, and the Ki-67 positive rate was between 30% and 75%. Follow-up data showed that two cases developed chest wall metastases, and in one case, there was progression to liver and abdominal metastases.

CONCLUSIONS

ILC of the breast are ER, PR and HER2 "triple negative", CK5/6 and EGFR positive, indicative of basal-like characteristics. Basal-like subtype of ILC are peculiarly prone to metastasis and poor response to chemotherapy, suggesting that it is associated with poor prognosis.

Spontaneous atopic dermatitis-like symptoms in a/a ma ft/ma ft/J flaky tail mice appear early after birth

Loss-of-function mutations in human profilaggrin gene have been identified as the cause of ichthyosis vulgaris (IV), and as a major predisposition factor for atopic dermatitis (AD). Similarly, flaky tail (a/a ma ft/ma ft/J) mice were described as a model for IV, and shown to be predisposed to eczema. The aim of this study was to correlate the flaky tail mouse phenotype with human IV and AD, in order to dissect early molecular events leading to atopic dermatitis in mice and men, suffering from filaggrin deficiency. Thus, 5-days old flaky tail pups were analyzed histologically, expression of cytokines was measured in skin and signaling pathways were investigated by protein analysis. Human biopsies of IV and AD patients were analyzed histologically and by real time PCR assays. Our data show acanthosis and hyperproliferation in flaky tail epidermis, associated with increased IL1β and thymic stromal lymphopoietin (TSLP) expression, and Th2-polarization. Consequently, NFκB and Stat pathways were activated, and IL6 mRNA levels were increased. Further, quantitative analysis of late epidermal differentiation markers revealed increased Small proline-rich protein 2A (Sprr2a) synthesis. Th2-polarization and Sprr2a increase may result from high TSLP expression, as shown after analysis of 5-days old K14-TSLP tg mouse skin biopsies. Our findings in the flaky tail mouse correlate with data obtained from patient biopsies of AD, but not IV. We propose that proinflammatory cytokines are responsible for acanthosis in flaky tail epidermis, and together with the Th2-derived cytokines lead to morphological changes. Accordingly, the a/a ma ft/ma ft/J mouse model can be used as an appropriate model to study early AD onset associated with profilaggrin deficiency.

Basal cytokeratin as a potential marker of low risk of invasion in ductal carcinoma in situ

OBJECTIVES

Biological markers that predict the development of invasive breast cancer are needed to improve personalized therapy for patients diagnosed with ductal carcinoma in situ. We investigated the role of basal cytokeratin 5/6 in the risk of invasion in breast ductal carcinoma in situ.

METHODS

We constructed tissue microarrays using 236 ductal carcinoma in situ samples: 90 pure samples (group 1) and 146 samples associated with invasive carcinoma (group 2). Both groups had similar nuclear grades and were obtained from patients of similar ages. The groups were compared in terms of estrogen (ER) and progesterone receptor (PR) status, human epidermal growth factor receptor 2 (HER2) expression, cytokeratin 5/6 immunostaining, human epidermal growth factor receptor 1 (EGFR) membrane staining and molecular subtype, as indicated by their immunohistochemistry profiles.

RESULTS

ER/PR-negative status was predictive of invasion, whereas HER2 superexpression and cytokeratin 5/6-positive status were negatively associated with invasion. Among the high-grade ductal carcinoma in situ cases, a triple-positive profile (positive for estrogen receptor, progesterone receptor, and HER2) and cytokeratin 5/6 expression by neoplastic cells were negatively associated with invasion. In the low-grade ductal carcinoma in situ subgroup, only cytokeratin 5/6 expression exhibited a negative association with the probability of invasion.

CONCLUSION

The immunohistochemical expression of cytokeratin 5/6 by ductal carcinoma in situ epithelial cells may provide clinically useful information regarding the risk of progression to invasive disease.

Id4 protein is highly expressed in triple-negative breast carcinomas: possible implications for BRCA1 downregulation

BRCA1 germline mutation carriers usually develop ER, PR and HER2 negative breast carcinoma. Somatic BRCA1 mutations are rare in sporadic breast cancers, but other mechanisms could impair BRCA1 functions in these tumors, particularly in triple-negative breast carcinomas (TNBCs). Id4, a helix-loop-helix DNA binding factor, blocks BRCA1 gene transcription in vitro and could downregulate BRCA1 in vivo. We compared Id4 immunoreactivity in 101 TNBCs versus 113 non-TNBCs, and correlated the results with tumor morphology and immunoreactivity for CK5/6, CK14, EGFR, and androgen receptor (AR). Id4 was present in 76 out of 101 (75 %) TNBCs: 40 (40 %) TNBCs displayed Id4 positivity in >50 % of neoplastic cells, 23 (23 %) in 5-50 %, and 13 (13 %) in <5 %. In contrast, only 6 (5 %) of 113 non-TNBCs showed focal Id4 positivity, limited to fewer than 5 % of the tumor (p < 0.0001). Id4 expression significantly associated with high histologic grade (p = 0.0002) and mitotic rate (p = 0.006). Id4 decorated all 12 TNBCs with large central acellular zone of necrosis in our series, with positive staining in 10-90 % of the cells. Id4 signal strongly correlated with cytokeratin CK14 reactivity (p < 0.0001), but not with CK5/6 and EGFR. All apocrine carcinomas in our series were positive for AR and most for EGFR, but they were negative for CK5/6, CK14, and Id4, with only two exceptions. Our results document substantial expression of Id4 in most TNBCs, which could result in functional downregulation of BRCA1 pathways in these tumors.

[Clinicopathologic and immunohistochemical study of 187 cases of intraductal papillary neoplasm of breast]

OBJECTIVE

To evaluate the diagnostic approach and criteria for intraductal papillary neoplasms of breast.

METHODS

According to the criteria of 2003 WHO classification, 187 cases of intraductal papillary neoplasm of breast were identified and enrolled into the study. The clinical and histologic features were reviewed and immunohistochemical study for CD10, p63, CK14, CK5/6, CK7, MGB1 and p53 were carried out on 53 cases.

RESULTS

Amongst the 187 cases studied, there were 128 cases of intraductal papilloma, 16 cases of atypical intraductal papilloma and 43 cases of intraductal papillary carcinoma. They showed a spectrum of morphologic features including epithelial and stromal hyperplasia and secondary changes. The expression of myoepithelial markers, including CD10 and p63, significantly decreased in ascending order from intraductal papillomas, atypical intraductal papillomas and intraductal papillary carcinomas (P < 0.001). The expression of basal cell markers, including CK5/6 and CK14, showed a mosaic pattern in benign lesions and significantly decreased or was absent in atypical and carcinomatous lesions (P < 0.001). In contrast, the luminal cell marker CK7 expressed in the three groups with no statistically significant difference (P = 0.06). On the other hand, the expression of MGB1 in intraductal papillary carcinomas was much lower than that in the other two groups (P = 0.002 and P = 0.007). The staining for p53 was negative in all of the three groups.

CONCLUSIONS

Intraductal papillary neoplasms of breast represent a heterogeneous group of lesions with various morphologic appearances. Correlation with immunostaining results for myoepithelial markers, basal-type cytokeratins and luminal epithelial markers are helpful in arriving at a definitive diagnosis.

[Clinicopathologic features of endolymphatic sac tumor at cerebellopontine angle]

OBJECTIVE

To study the clinicopathologic features and immunophenotype of endolymphatic sac tumor (ELST) and normal endolymphatic sac.

METHODS

The clinical and histologic features were evaluated in 5 cases of ELST. Eight cases of choroid plexus papilloma at cerebellopontine angle and 2 cases of normal endolymphatic sac were used as controls. Immunohistochemical study for vimentin, AE1/AE3, CK8/18, CK5/6, EMA, GFAP, synaptophysin, S-100 protein, CEA, TTF-1, VEGF, D2-40, calponin, calretinin and Ki-67 was carried out.

RESULTS

The age of onset of ELST ranged from 23 to 35 years (median = 24 years). The male-to-female ratio was 2:3. The clinical presentation was tinnitus, otalgia, hearing loss, otorrhagia with effusion and headache. The duration of symptoms ranged from 6 months to 10 years. Local recurrences were noted in 3 cases. Radiologically, the tumors were located at cerebellopontine angle and demonstrated petrous bone destruction. Histologic examination showed that the tumors had a papillary-glandular pattern. The papillae were covered by a single layer of low cuboidal cells. The tumor cells had distinct cell borders and contained eosinophilic to clear cytoplasm. The nuclei were slightly atypical and sometimes apically located. Focal dilated glandular structures with colloid-like material were also identified. The surrounding stroma was vascularized. All of the 5 cases had dural or petrous bone infiltration. Immunohistochemical study showed that all of the 5 cases were positive for AE1/AE3, CK8/18, CK5/6 and VEGF, 4 cases for EMA, 3 cases for calponin (focal), 2 cases for vimentin, 2 cases for S-100 protein, 1 case for GFAP and 1 case for synaptophysin (focal and weak). The Ki-67 index measured less than 1%. The staining for D2-40, calretinin, CEA and TTF-1 was negative. The 2 cases of the normal endolymphatic sac were positive for AE1/AE3 and CK8/18, and negative for CK5/6, EMA, S-100 protein, GFAP and synaptophysin. The 8 cases of choroid plexus papilloma were positive for synaptophysin. Seven cases were also positive for S-100 protein, 2 cases for GFAP and 1 case for D2-40. All of the 8 cases were negative for EMA, CK5/6 and calponin.

CONCLUSIONS

ELST is a rare slow-growing and potentially malignant tumor with a tendency of bone invasion and local recurrence. Distant metastasis is not observed. It must be distinguished from choroid plexus papilloma occurring at cerebellopontine angle. Correlation with clinical, radiologic and immunohistochemical findings would also be helpful.

Cytokeratin profile in exfoliative cytology of smokers

OBJECTIVE

To compare the expression of cytokeratins (CKs) 6, 16, 19 and pan-cytokeratin (PAN) in oral mucosa cells between smokers and nonsmokers to determine the proliferative activity and expression indicative of a potential for malignant transformation.

STUDY DESIGN

Smears were obtained from the left lateral border of the tongue with a cytobrush from 25 smokers and 20 nonsmokers seen at the clinics of São José dos Campos Dental School, São Paulo State University, São José dos Campos, São Paulo, Brazil, and processed for immunohistochemistry. Conventional microscopy was used for qualitative analysis. Proportions were compared statistically by the z-test and Fisher's exact test.

RESULTS

The expression of CK6 (p = 0.002), CK16 (p = 0.003), CK19 (p = 0.0001) and PAN (p = 0.008) was higher in oral mucosa smears from smokers compared to nonsmokers.

CONCLUSION

The expression of CK6 and CK16 demonstrated increased epithelial proliferation in the oral mucosa of smokers, and expression of CK19 indicated alterations in epithelial maturation. The expression of PAN indicates the need for the investigation of other types of CK in further studies.

Clinicopathlogic and immunohistochemical characteristics of triple negative invasive lobular carcinoma

PURPOSE

Our study is performed to find out clinicopathlogic and immunohistochemical (IHC) characteristics of triple negative invasive lobular carcinoma (ILC), as has been demonstrated in their invasive ductal counterparts.

MATERIALS AND METHODS

Retrospective analysis of variable clinicopathlogic parameters and IHC stains for androgen receptor, estrogen receptor, progesterone receptor, p53, c-kit, galectin-3, cytokeratin 5 (CK5), CK5/6, vimentin, E-cadherin, epidermal growth factor receptor, and HER2 were performed in 117 cases of ILC.

RESULTS

Eight cases (6.8%) were triple negative carcinoma (TNC), which showed higher incidence of high histologic grade than non-TNC (p = 0.019). Galectin-3 was expressed with higher incidence in tumor cells of TNC (62.5%) than those of non-TNC (7.3%) (p = 0.000). In contrast, galectin-3 was expressed with higher incidence in stromal cells of non-TNC (53.2%) than those of TNC (12.5%) (p = 0.029). CK5 and CK5/6 were not expressed in all ILCs.

CONCLUSION

TNC in ILC showed distinct clinicopathologic and IHC characteristics such as higher histologic grade and increased expression of galectin-3, compared to non-TNC in ILC. TNC in ILC was less frequent and did not show CK5 and CK5/6 expression when compared to TNC in invasive ductal carcinoma.

Primary combined small cell carcinoma of larynx with lateralized histologic components and corresponding side-specific neck nodal metastasis: report of a unique case and review of literature

Combined small cell carcinoma (neuroendocrine) of the larynx has been rarely reported in the literature, and included in the current WHO classification. We hereby report an unusual case of combined carcinoma of the larynx; composed mainly of small cell neuroendocrine carcinoma nearly confined to the right side (mainly involving supraglottis extending to glottis) with synchronous minor in-situ and invasive squamous cell carcinoma component located on the left side of larynx (mainly glottis). Interestingly, this side-specific distribution of tumor was recapitulated in its metastatic nodal spread; so that right cervical lymph nodes showed only metastatic small cell carcinoma and left cervical lymph nodes only metastatic squamous cell carcinoma. To the best of our knowledge, the present case is the seventeenth reported case of a combined small cell carcinoma of larynx, second case in which individual tumor components were lateralized on either side of larynx, and the first case in which this side-specificity of tumor was reflected in its metastatic neck nodal spread. This report emphasizes the value of accurate pathologic diagnosis including diversity in differentiation and localization of laryngeal tumors, and underscores the need for thorough pathologic examination of bilateral laryngeal tumors. The pre-operative diagnostic yield of small cell carcinoma (pure or combined) can be enhanced by including deeper submucosal biopsies on laryngoscopy in all those cases in which the extent of disease on imaging is disproportionately larger than the apparent mucosal involvement on laryngoscopy. This approach can facilitate selection of neoadjuvant or palliative chemo-radiotherapy in large or unresectable tumors.

Laparoscopic aspiration cytology in rheumatoid ascites: a case report

BACKGROUND

To the best of our knowledge, there are currently no recorded cytologic features of any effusion from rheumatoid peritonitis showing cytologic findings linked to rheumatoid pleural disease, although rheumatoid nodules have been described in the peritoneum.

CASE

A 75-year-old man with longstanding, poorly controlled rheumatoid arthritis was seen in our hospital after a motor vehicle collision. Computed tomography showed free fluid in the abdominal cavity. Laparoscopic examination revealed a large amount of nonhemorrhagic ascitic fluid and no traumatic intraabdominal injuries. Abdominal and peritoneal surfaces appeared completely normal. The ascitic fluid was aspirated through the laparoscope and sent for cytologic examination. Cytospin preparations revealed histiocytes and loosely cohesive clusters of small cytologically bland epithelioid cells amid acute inflammatory cells and granular necrotic debris. Cell block material displayed transected fibroconnective tissue fragments lined by hyperplastic mesothelium with squamous metaplasia. Immunohistochemical studies revealed that the mesothelial cells were positive for calretinin, cytokeratin 5/6, and p63.

CONCLUSION

The ascites was attributed to peritoneal disease from rheumatoid arthritis, based on the cytologic findings, immuno-profile, exclusion of other possible causes (i.e., cirrhosis, nephrotic syndrome, protein-losing enteropathy, or drugs), and patient's clinical setting.

Loss of stromal caveolin-1 expression predicts poor clinical outcome in triple negative and basal-like breast cancers

Here, we investigated the possible predictive value of stromal caveolin-1 (Cav-1) as a candidate biomarker for clinical outcome in triple negative (TN) breast cancer patients. A cohort of 85 TN breast cancer patients was available, with the necessary annotation and nearly 12 years of follow-up data. Our primary outcome of interest in this study was overall survival. Interestingly, TN patients with high-levels of stromal Cav-1 had a good clinical outcome, with >50% of the patients remaining alive during the follow-up period. In contrast, the median survival for TN patients with moderate stromal Cav-1 staining was 33.5 months. Similarly, the median survival for TN patients with absent stromal Cav-1 staining was 25.7 months. A comparison of 5-year survival rates yields a similar pattern. TN patients with high stromal Cav-1 had a good 5-year survival rate, with 75.5% of the patients remaining alive. In contrast, TN patients with moderate or absent stromal Cav-1 levels had progressively worse 5-year survival rates, with 40 and 9.4% of the patients remaining alive. In contrast, in a parallel analysis, the levels of tumor epithelial Cav-1 had no prognostic significance. As such, the prognostic value of Cav-1 immunostaining in TN breast cancer patients is compartment-specific, and selective for an absence of Cav-1 staining in the stromal fibroblast compartment. A recursive-partitioning algorithm was used to assess which factors are most predictive of overall survival in TN breast cancer patients. In this analysis, we included tumor size, histologic grade, whether the patient received surgery, radiotherapy or chemotherapy, CK5/6, EGFR, p53 and Ki67 status, as well as the stromal Cav-1 score. This analysis indicated that stromal loss of Cav-1 expression was the most important prognostic factor for overall survival in TN breast cancer. Virtually identical results were obtained with CK5/6 (+) and/or EGFR (+) TN breast cancer cases, demonstrating that a loss of stromal Cav-1 is also a strong prognostic factor for basal-like breast cancers. Our current findings may have important implications for the close monitoring and treatment stratification of TN and basal-like breast cancer patients.

[Relationship between breast cancer molecular subtypes with clinicopathological characteristics and prognosis]

OBJECTIVES

This study try to subclassify breast cancer into different prognostic subgroups according to immunohistochemical algorithm and discuss the relationship between subtypes and biological and clinical behavior and prognosis.

METHODS

One hundred and twenty-eight cases of infiltrative ductal carcinoma were studied using immunohistochemical staining with an antibody panel of ER, PR, HER2 and CK5/6 and subclassified referring to previous reports, and the 9 cases of HER2 positive subtype were tested using FISH.

RESULTS

The expression of ER, PR, HER2, and CK5/6 was detected in 67%, 45%, 27% and 27% cases, respectively. All cases were subclassified into five subgroups, with luminal A (55%), luminal B (20%), HER2 positive (7%), basal-like (10%) and unclassified cases (8%). Nine HER2 positive cases all showed amplification of HER2 gene. It was demonstrated that the luminal A group was associated with the best prognosis but the basal-like group worst by univariate analysis. Multivariate analysis demonstrated that both the clinical stage and immunohistochemical subtypes of tumor were related to overall survival. Menses status were different among these subtypes.

CONCLUSION

According to the expression of ER, PR, HER2 and CK5/6, infiltrative ductal carcinoma could be subclassified into five subgroups with different biological features and outcome, having a role in evaluating the prognosis and guiding the clinical treatment.