YAP immunoreactivity is directly related to pilomatrixoma size and proliferation rate

A comparative study of pilomatricoma and epidermoid cyst with ultrasound

AIM

To explore and compare the ultrasonic (US) features of pilomatricoma (PM) and epidermoid cyst (EC) in the differential diagnosis and improve the accuracy of US diagnosis of PM.

MATERIALS AND METHODS

Three hundred and nine patients who underwent US examination before surgery with a histopathological diagnosis of PM or EC after surgery were analysed retrospectively. The patients were categorised into the training and validation sets according to the inspection times. Univariate analysis was undertaken on the US and clinical features of PM and statistically significant variables (p<0.05) were included in the multivariate logistic regression model to establish a diagnostic model.

RESULTS

The results demonstrated that the multivariate logistic regression model for PM was statistically significant (p<0.001). The risk factors included posterior echo attenuation and hypoechoic halos (odds ratio [OR] = 9.277, 10.254) and the protective factors included age, diameter thickness, and posterior echo enhancement (OR=0.936, 0.302, 0.156). The performance of the diagnostic model was tested using the training set (area under the receiver operating characteristic curve [AUC] = 0.974, 95% confidence interval [CI] = 0.955-0.994) and the validation set (AUC = 0.967, 95% CI = 0.926-1.000), which demonstrated good discriminant ability.

CONCLUSIONS

The diagnostic accuracy for PM was higher than that for EC when the nodule is characterised by posterior echo attenuation, hypoechoic halos, smaller thickness, and younger age. The US diagnostic model developed may be used to guide the diagnosis of PM.

Targeting the Hippo/YAP/TAZ signalling pathway: Novel opportunities for therapeutic interventions into skin cancers

Skin cancers are by far the most frequently diagnosed human cancers. The closely related transcriptional co-regulator proteins YAP and TAZ (WWTR1) have emerged as important drivers of tumour initiation, progression and metastasis in melanoma and non-melanoma skin cancers. YAP/TAZ serve as an essential signalling hub by integrating signals from multiple upstream pathways. In this review, we summarize the roles of YAP/TAZ in skin physiology and tumorigenesis and discuss recent efforts of therapeutic interventions that target YAP/TAZ in in both preclinical and clinical settings, as well as their prospects for use as skin cancer treatments.

Role of Yes-Associated Protein in Psoriasis and Skin Tumor Pathogenesis

Psoriasis and skin tumors (such as basal cell carcinoma, squamous cell carcinoma, and melanoma) are chronic diseases that endanger physical and mental health, and yet the causes are largely unknown and treatment options limited. The development of targeted drugs requires a better understanding of the exact pathogenesis of these diseases, and Yes-associated protein (YAP), a member of the Hippo signaling pathway, is believed to play an important role. Psoriasis and skin tumors are characterized by excessive cell proliferation, abnormal differentiation, vasodilation, and proliferation. Here, we review the literature related to YAP-associated disease mechanisms and discuss the latest research. YAP regulates cell apoptosis, proliferation, and differentiation; inhibits cell density and intercellular contacts and angiogenesis; and maintains the three-dimensional structure of the skin. These mechanisms may be associated with the occurrence and development of psoriasis and skin tumors. The results of recent studies have shown that YAP expression is increased in psoriasis and skin tumors. High expression of YAP in psoriasis and skin tumors may indicate its positive functions in skin inflammation and malignancies and may play an important role in disease pathogenesis. The study of new drugs targeting YAP can provide novel approaches for the treatment of skin diseases.

The Roles of YAP/TAZ and the Hippo Pathway in Healthy and Diseased Skin

Skin is the largest organ of the human body. Its architecture and physiological functions depend on diverse populations of epidermal cells and dermal fibroblasts. Reciprocal communication between the epidermis and dermis plays a key role in skin development, homeostasis and repair. While several stem cell populations have been identified in the epidermis with distinct locations and functions, there is additional heterogeneity within the mesenchymal cells of the dermis. Here, we discuss the current knowledge of how the Hippo pathway and its downstream effectors Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) contribute to the maintenance, activation and coordination of the epidermal and dermal cell populations during development, homeostasis, wound healing and cancer.

A new case of the pilomatrixoma rare in the preauricular region and review of series of cases

Pilomatrixoma is considered a rare benign tumor arising from the hair follicle, most common in the head and neck region, but it is rarely diagnosed on a clinical basis. This report describes a new case of giant pilomatrixoma in a 36-year-old female patient. The nodule was localized in the preauricular area on the right side, appearing as a slow-growing, fixed, painless, with a hardened consistency, unusual giant (4.5 cm). A cone-beam computed tomography (CBCT) examination showed a slightly hyperdense lesion, and fine-needle aspiration cytology (FNAC) revealed peripheral blood and mononucleated inflammatory cells. After enucleation of lesion, a diagnosis of pilomatrixoma was confirmed. The differential diagnosis of pilomatrixoma is broad, because its characteristics also can be found in other lesions common to the head and neck. Thus, a lesion in the head and neck, adherent to the skin, and well demarcated, mainly in the young and in females, should be suspected as pilomatrixoma.

YAP, TAZ and AREG expression in eighth cranial nerve schwannoma

BACKGROUND

Although the diagnosis and treatment of eighth cranial nerve (VIII CN) schwannoma (acoustic neuroma) has improved over the years, no factors capable of predicting tumor growth have been identified as yet. This study is a preliminary investigation of the expression in sporadic VIII CN schwannomas of Yes-associated protein (YAP), transcriptional coactivator with PDZ-binding motif (TAZ), and amphiregulin (AREG), a direct target gene of YAP and TAZ. The expression of YAP, TAZ and AREG was correlated with the volumetric dimensions of tumors on contrast-enhanced magnetic resonance imaging (ceMRI).

METHODS

YAP, TAZ and AREG expression was assessed immunohistochemically in surgical specimens of 36 consecutive sporadic VIII CN schwannomas. 3D reconstructions of the tumors and their corresponding volumes in cm3 were obtained from measurements on ceMRI images using the OsiriX® software.

RESULTS

We found a significant direct correlation between TAZ expression and VIII CN schwannoma volumes on latest preoperative ceMRI (p<0.0003). Mean TAZ expression was also significantly higher in VIII CN schwannomas with a volume ≥2.1 cm3 than in those with a volume <2.1 cm3(p<0.0018). No significant correlations emerged for YAP or AREG expression and VIII CN schwannoma volume.

CONCLUSIONS

The immunohistochemical expression of TAZ (but not YAP or AREG) correlated significantly with schwannoma volume measured on ceMRI. Further investigations are needed to identify the biological factors influencing tumor proliferation (ideally secreted proteins like AREG) that might be detected using non-invasive approaches (i.e., blood samples).

miR-130A as a diagnostic marker to differentiate malignant mesothelioma from lung adenocarcinoma in pleural effusion cytology

BACKGROUND

Malignant pleural mesothelioma is a rare tumor with a dismal prognosis, usually presenting with recurrent effusions. However, the majority of malignant pleural effusions are due to lung adenocarcinoma (AdC). The distinction between these tumors has considerable therapeutic and medicolegal implications and can be very challenging both histologically and cytologically. Appropriate immunohistochemistry (IHC) is required to support the diagnosis. MicroRNA (miRNA) expression analysis could be a viable diagnostic tool for distinguishing between these tumors. The purpose of the current study was to assess the reliability of miRNAs as diagnostic markers to differentiate epithelioid malignant mesothelioma (MM) from lung AdC.

METHODS

Bioinformatic analysis of publicly searchable data sets regarding miRNA expression profiling was performed to select the most significant differentially expressed miRNAs. These were analyzed by quantitative polymerase chain reaction on histologic (41 MM cases and 40 lung AdC cases) and cytological (26 MM cases and 27 lung AdC cases) specimens and the diagnostic performances were assessed.

RESULTS

miR-130a, miR-193a, miR-675, miR-141, miR-205, and miR-375 were found to be the best distinguishing markers. Of these, only miR-130a was significantly overexpressed in MM compared with lung AdC (P =.029 in histologic and P =.014 in cytological samples). miR-130a demonstrated a sensitivity of 77%, a specificity of 67%, a positive predictive value of 69%, a negative predictive value of 75%, and an accuracy of 72% in identifying MM.

CONCLUSIONS

The diagnostic performances of miR-130a expression analysis and IHC appear to be similar. miR-130a quantification could be used reliably as second-level diagnostic tool to differentiate MM from lung AdC in pleural effusion cytology, mainly in those cases with ambiguous or negative IHC. Further validation is needed. Cancer Cytopathol 2017;125:635-43. © 2017 American Cancer Society.