Disabled 2 (Dab2) Regulates Tumour Progression in Skin Squamous Cell Carcinoma.

Dab2 is an endocytic adaptor protein involved in various physiological processes and signaling pathways. Dab2 is deregulated in various cancers; however, its role in skin squamous cell carcinoma ( SCC) has not been elucidated yet. In the present study, we used the DMBA/TPA induced murine skin carcinogenesis model to examine the role of Dab2 in skin tumour progression. We generated tamoxifen inducible Dab2 conditional knockout system for our study. Loss of Dab2 led to delayed papilloma initiation and reduced papilloma burden. Delayed papilloma initiation was due to reduce proliferative potential of the papillomas due to Dab2 loss. Furthermore, while the WT papillomas progressed to SCC, the papillomas formed in Dab2 cKO mice failed to undergo malignant conversion to SCC. Dab2 cKO tumours showed reduced expression of K8, a marker for aggressive tumour. Moreover, Dab2 ckO tumours failed to undergo EMT as shown by reduced expression of Vimentin and Twist1. Dab2 cKO tumours also showed reduced expression of Sox2, a stem cell marker. Furthermore, qPCR analysis showed upregulation of Dab2 expression in the human skin cancer cell lines as compared to normal human skin keratinocytes. In patients, TCGA data analysis of skin cancer melanoma (SKCM) showed a trend where high levels of Dab2 correlated with poor overall survival. The present study shows that Dab2 promotes tumour progression in skin SCC.

The Diagnostic Value of microRNA Expression Analysis in Detecting Intraductal Papillomas in Patients with Pathological Nipple Discharge.

Patients with pathological nipple discharge (PND) often undergo local surgical procedures because standard radiologic imaging fails to identify the underlying cause. MicroRNA (MiRNA) expression analysis of nipple fluid holds potential for distinguishing between breast diseases. This study aimed to compare miRNA expression levels between nipple fluids from patients with PND to identify possible relevant miRNAs that could differentiate between intraductal papillomas and no abnormalities in the breast tissue. Nipple fluid samples from patients with PND without radiological and pathological suspicion for malignancy who underwent a ductoscopy procedure were analyzed. We used univariate and multivariate regression analyses to identify nipple fluid miRNAs differing between pathologically confirmed papillomas and breast tissue without abnormalities. A total of 27 nipple fluid samples from patients with PND were included for miRNA expression analysis. Out of the 22 miRNAs examined, only miR-145-5p was significantly differentially expressed (upregulated) in nipple fluid from patients with an intraductal papilloma compared to patients showing no breast abnormalities (OR 4.76, p = 0.046), with a diagnostic accuracy of 92%. miR-145-5p expression in nipple fluid differs for intraductal papillomas and breast tissue without abnormalities and, therefore, has potential as a diagnostic marker to signal presence of papillomas in PND patients. However, further refinement and validation in clinical trials are necessary to establish its clinical applicability.

Involvement of TLR9 in priming the immune response in oral papillomatosis induced by low-risk HPV.

Oral papillomatosis represents a benign lesion of the oral mucosa often induced by human papillomavirus (HPV) or having a non-infection local or general etiology. HPVs are very well adapted and efficient viruses able to produce changes in the immune system, endowed with the ability to replicate in the keratinocytes and to remain silent. The natural evolution of HPV infection is different, depending on the efficiency of the innate immune system. The purpose of this study was to explore Toll-like receptor 9 (TLR9) immunohistochemical expression in low-risk (LR)-HPV oral infection and its ability to facilitate an efficient immune response by activating the macrophages, which serve as main antigen-presenting cells. Samples of two groups of oral mucosae - LR-HPV-positive and HPV-negative - were processed for immunohistochemistry technique and incubated with antibody against TLR9 and cluster of differentiation 68 (CD68). Image analysis and morphometry were conducted to assess the intensity of TLR9 immune signal in the epithelium and the number of macrophages labeled by CD68. We found a statistically significant difference between macrophage count for the subjects in HPV-positive and HPV-negative groups; thought no significant differences of TLR9 immune signal was noted, which demonstrates a diminished immune response in HPV-positive group, probably influencing the time of lesion's clearance.

Mesenchymal stem cells-derived exosomal miR-653-5p suppresses laryngeal papilloma progression by inhibiting BZW2.

OBJECTIVES: Although miR-653-5p has been validated to participate in the progression of multiple types of cancer, the functional role of exosomal miR-653-5p derived from Mesenchymal Stem Cells (MSCs) in Laryngeal Papilloma (LP) has still remained elusive. Hence, this study aimed to investigate the role of MSCs-derived exosomal miR-653-5p in LP. METHODS: LP tissues (n = 15) and adjacent normal tissues (n = 10) were collected to examine the expression level of miR-653-5p. The expression level of miR-653-5p in LP cells and normal cells was also detected. Then, miR-653-5p was overexpressed or silenced to explore its effects on the proliferation, migration, invasion, and apoptosis of LP cells. Thereafter, the effects of exosomal miR-653-5p derived from MSCs on LP cell progression and the potential regulatory mechanism of miR-653-5p were assessed. RESULTS: It was revealed that the expression level of miR-653-5p was downregulated in LP tissues and cells. In addition, miR-653-5p suppressed the proliferation, migration, invasion, and apoptosis of LP cells. Exosomes derived from MSCs played a suppressive role in LP development and mediated the transmission of miR-653-5p to LP cells. Further exploration identified Basic leucine Zipper and W2 domains 2 (BZW2) as the target of miR-653-5p. More importantly, the rescue experiments revealed that MSCs-secreted exosomal miR-653-5p efficiently inhibited the aggressive phenotypes of LP cells, which could be significantly reversed by BZW2 overexpression in LP cells. CONCLUSION: MSCs-derived exosomal miR-653-5p exerted inhibitory effects on LP progression through targeting BZW2, which provided a novel idea for the therapy of LP. CLINICAL TRIAL REGISTRATION NUMBER: chictr-ior-17011021.

Long non-coding RNA nuclear-enriched abundant transcript 1 (LncRNA NEAT1) upregulates Cyclin T2 (CCNT2) in laryngeal papilloma through sponging miR-577/miR-1224-5p and blocking cell apoptosis.

Long non-coding RNA nuclear-enriched abundant transcript 1 (Lnc-NEAT1) is a crucial mediator in cancer progression, which is associated with poor prognosis of patients with laryngeal papilloma (LP). Herein, we aimed to determine how Lnc-NEAT1 promotes LP development. q-PCR, MTT, EDU and Western blotting were performed to determine that Lnc-NEAT1 facilitates LP cell proliferation and hinders cell apoptosis. LncBase database, q-PCR, GEPIA online database, Dual luciferase reporter and RIP assays were utilized to confirm that Lnc-NEAT1 sponged miR-577/miR-1224-5p and negatively mediated CCNT2. Western blotting, MTT and EDU were used to confirm that Lnc-NEAT1 promoted LP cell proliferation and inhibited cell apoptosis through CCNT2. Lnc-NEAT1 was highly expressed in LP, and enhanced LP cell proliferation, and it was inhibited by Lnc-NEAT1 depleting. Concerning the underlying mechanism, it was found that Lnc-NEAT1 could functionally sponge microRNA-577 (miR-577) and microRNA-1224-5p (miR-1224-5p) and up-regulate Cyclin T2 (CCNT2) in LP cells. Notably, CCNT2 knockdown blocked Lnc-NEAT1-induced LP cell proliferation, and rescued cell apoptosis, which was specifically indicated by restoration of Bax, Cleaved caspase 3 and Cleaved caspase 9. Lnc-NEAT1 played a carcinogenic role in LP through mediating miR-577 or miR-1224-5p/CCNT2 axis, which may provide promising insights for the treatment of LP.

Immune delineation of laryngeal papilloma reveals enhanced neutrophil associated gene profile.

Laryngeal papilloma (LP) is a rare benign disease, caused by recurrent multisite papillomas that are referred to as recurrent respiratory papillomatosis (RRP). RRP is caused primarily by two types of human papillomavirus (HPV): HPV6 and HPV11. The immune dysregulation within the microenvironment of the lesions has been shown to likely play a role in the development of RRP. The present study aimed at analyzing the transcriptional profile of immune response genes and cancer-related genes in the LP microenvironment. We used the NanoString® nCounter® analysis system to study expression of 730 genes among seven paired samples of LP and healthy laryngeal (HL) tissue. qRT-PCR and flow cytometric analysis was performed to confirm identified transcripts and follow-up scores of infiltrating immune cells, respectively. In total, 113 differentially expressed transcripts were detected of which 37 showed increased expression levels and 76 decreased expression levels in the LP samples compared to the HL samples (fold change ≥ 2). Transcripts with increased expression levels included S100As (A7, A8, and A12), CEACAM1, neutrophil activation associated cytokines (IL8), chemokines (CXCL6), and IL receptors, e.g., IL4R. Transcripts with decreased expression in LP were associated with innate and adaptive immunity. Overall, HPV6 and 11 were present in 67% and 33% of the patients, respectively. There was a significant increase in neutrophils and a significant decrease in CD8+ T cells in LP. LP samples display an immune profile characterized by enhanced expression of neutrophilic markers and significantly reduced T cell-associated markers.

DOT1L modulates the senescence-associated secretory phenotype through epigenetic regulation of IL1A.

Oncogene-induced senescence (OIS) is a stable cell cycle arrest that occurs in normal cells upon oncogene activation. Cells undergoing OIS express a wide variety of secreted factors that affect the senescent microenvironment termed the senescence-associated secretory phenotype (SASP), which is beneficial or detrimental in a context-dependent manner. OIS cells are also characterized by marked epigenetic changes. We globally assessed histone modifications of OIS cells and discovered an increase in the active histone marks H3K79me2/3. The H3K79 methyltransferase disruptor of telomeric silencing 1-like (DOT1L) was necessary and sufficient for increased H3K79me2/3 occupancy at the IL1A gene locus, but not other SASP genes, and was downstream of STING. Modulating DOT1L expression did not affect the cell cycle arrest. Together, our studies establish DOT1L as an epigenetic regulator of the SASP, whose expression is uncoupled from the senescence-associated cell cycle arrest, providing a potential strategy to inhibit the negative side effects of senescence while maintaining the beneficial inhibition of proliferation.

Molecular characterization of a marine turtle tumor epizootic, profiling external, internal and postsurgical regrowth tumors.

Sea turtle populations are under threat from an epizootic tumor disease (animal epidemic) known as fibropapillomatosis. Fibropapillomatosis continues to spread geographically, with prevalence of the disease also growing at many longer-affected sites globally. However, we do not yet understand the precise environmental, mutational and viral events driving fibropapillomatosis tumor formation and progression.Here we perform transcriptomic and immunohistochemical profiling of five fibropapillomatosis tumor types: external new, established and postsurgical regrowth tumors, and internal lung and kidney tumors. We reveal that internal tumors are molecularly distinct from the more common external tumors. However, they have a small number of conserved potentially therapeutically targetable molecular vulnerabilities in common, such as the MAPK, Wnt, TGFß and TNF oncogenic signaling pathways. These conserved oncogenic drivers recapitulate remarkably well the core pan-cancer drivers responsible for human cancers. Fibropapillomatosis has been considered benign, but metastatic-related transcriptional signatures are strongly activated in kidney and established external tumors. Tumors in turtles with poor outcomes (died/euthanized) have genes associated with apoptosis and immune function suppressed, with these genes providing putative predictive biomarkers.Together, these results offer an improved understanding of fibropapillomatosis tumorigenesis and provide insights into the origins, inter-tumor relationships, and therapeutic treatment for this wildlife epizootic.

False-Positive Uptake of 131I From Basal Cell Papilloma in a Patient With Metastatic Papillary Thyroid Cancer.

ABSTRACT: A 64-year-old woman with metastatic papillary thyroid cancer underwent a total thyroidectomy followed by 2 courses of 131I therapy. The posttherapeutic whole-body scan after the second dose of 131I therapy showed multifocal bone metastasis. In addition, there is focal abnormal intense radiotracer uptake at the right inguinal region. SPECT/CT revealed that this abnormal focal radioactivity was from a superficial skin lesion. Further physical examination revealed a raised, approximately 1-cm, irregular grayish-brown lesion on the right groin skin. Histopathological examination confirmed the diagnosis of basal cell papilloma (seborrheic keratosis).

MACE RNA sequencing analysis of conjunctival squamous cell carcinoma and papilloma using formalin-fixed paraffin-embedded tumor tissue.

Recent advances in the field of biomedical research allow for elucidation of the transcriptional signature of rare tumors such as conjunctival squamous cell carcinoma (SCC). In this study we compare its expression profile to conjunctival papilloma (Pap) and healthy conjunctival tissue (Ctrl) and develop a classification tool to differentiate these entities. Seven conjunctival SCC, seven Pap and ten Ctrl were formalin-fixed and paraffin-embedded (FFPE) and analyzed using Massive Analysis of cDNA Ends (MACE) RNA sequencing. Differentially expressed genes (DEG) and gene ontology (GO) clusters were explored and the abundance of involved cell types was quantified by xCell. Finally, a classification model was developed to distinguish SCC from Pap and Ctrl. Among the most prominent DEG in SCC a plethora of keratins were upregulated when compared to Pap and Ctrl. xCell analysis revealed an enrichment of immune cells, including activated dendritic cells and T-helper type 1 cells (Th1), in SCC when compared to Ctrl. The generated classification model could reliably discriminate between the three entities according to the expression pattern of 30 factors. This study provides a transcriptome-wide gene expression profile of rare conjunctival SCC. The analysis identifies distinct keratins, as well as dendritic and Th1 cells as important mediators in SCC. Finally, the provided gene expression classifier may become an aid to the conventional histological classification of conjunctival tumors in uncertain cases.

Chronic expression of p16INK4a in the epidermis induces Wnt-mediated hyperplasia and promotes tumor initiation.

p16INK4a (CDKN2A) is a central tumor suppressor, which induces cell-cycle arrest and senescence. Cells expressing p16INK4a accumulate in aging tissues and appear in premalignant lesions, yet their physiologic effects are poorly understood. We found that prolonged expression of transgenic p16INK4a in the mouse epidermis induces hyperplasia and dysplasia, involving high proliferation rates of keratinocytes not expressing the transgene. Continuous p16INK4a expression increases the number of epidermal papillomas formed after carcinogen treatment. Wnt-pathway ligands and targets are activated upon prolonged p16INK4a expression, and Wnt inhibition suppresses p16INK4a-induced hyperplasia. Senolytic treatment reduces p16INK4a-expressing cell numbers, and inhibits Wnt activation and hyperplasia. In human actinic keratosis, a precursor of squamous cell carcinoma, p16INK4a-expressing cells are found adjacent to dividing cells, consistent with paracrine interaction. These findings reveal that chronic p16INK4a expression is sufficient to induce hyperplasia through Wnt-mediated paracrine stimulation, and suggest that this tumor suppressor can promote early premalignant epidermal lesion formation.

Dysregulated Expression of Phosphorylated Epidermal Growth Factor Receptor and Phosphatase and Tensin Homologue in Canine Cutaneous Papillomas and Squamous Cell Carcinomas.

The molecular mechanisms contributing to the development of cutaneous papillomas (CPs) and cutaneous squamous cell carcinomas (CSCCs) are still poorly understood, limiting the ability to identify molecular suitable targets for the development of novel therapies. Persistent activation of the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) signalling pathway is a component of epidermal carcinogenesis in dogs. The present study describes the immunohistochemical expression pattern of two key regulatory molecules involved in the PI3K/Akt/mTOR signalling pathway, phosphorylated epidermal growth factor receptor (pEGFR)Tyr1068 and phosphatase and tensin homologue (PTEN), in samples of normal canine epidermis, CP, preneoplastic epidermis and CSCC using tissue microarrays to determine whether the deregulated activity of these molecules is involved in the pathogenesis of these relevant epidermal tumours of dogs. Expression of pEGFR and PTEN was dysregulated in most samples of CP, preneoplastic epidermis and CSCC. Overexpression of pEGFR, together with decreased expression of PTEN, may facilitate the progression of some canine CPs and CSCCs by deregulation of the key cellular functions in which the PI3K/Akt/mTOR signalling pathway is involved. These findings suggest that the PI3K/Akt/mTOR signalling molecules may be potential therapeutic targets for canine patients with CP and CSCC.

Epidermal ROCK2 induces AKT1/GSK3ß/ß-catenin, NFκB and dermal tenascin C; but enhanced differentiation and p53/p21 inhibit papilloma.

ROCK2 roles in epidermal differentiation and carcinogenesis have been investigated in mice expressing an RU486-inducible, 4HT-activated ROCK2 transgene (K14.creP/lslROCKer). RU486/4HT-mediated ROCKer activation induced epidermal hyperplasia similar to cutaneous oncogenic rasHa (HK1.ras); however ROCKer did not elicit papillomas. Instead, anomalous basal-layer ROCKer expression corrupted normal ROCK2 roles underlying epidermal rigidity/stiffness and barrier maintanance, resulting in premature keratin K1, loricrin and filaggrin expression. Also, hyperproliferative/stress-associated keratin K6 was reduced; possibly reflecting altered ROCK2 roles in epidermal rigidity and keratinocyte flexibility/migration during wound healing. Consistent with increased proliferation, K14.creP/lslROCKer hyperplasia displayed supra-basal-to-basal increases in activated p-AKT1, inactivated p-GSK3ß ser9 and membranous/nuclear ß-catenin expression together with weak NFκB, which were absent in equivalent HK1.ras hyperplasia. Furthermore, ROCKer-mediated increases in epidermal rigidity via p-MypT1 inactivation/elevated MLC, coupled to anomalous ß-catenin expression, induced tenascin C-positive dermal fibroblasts. Alongside an altered ECM, these latent tenascin C-positive dermal fibroblasts may become putative pre-cancer-associated fibroblasts (pre-CAFs) and establish a susceptibility that subsequently contributes to tumour progression. However, anomalous differentiation was also accompanied by an immediate increase in basal-layer p53/p21 expression; suggesting that while ROCK2/AKT1/ß-catenin activation increased keratinocyte proliferation resulting in hyperplasia, compensatory p53/p21 and accelerated differentiation helped inhibit papillomatogenesis.

Relationship between inflammation and the severity of Recurrent Respiratory Papillomatosis.

OBJECTIVE: To characterize inflammatory cells in Recurrent Respiratory Papillomatosis (RRP) and to correlate it with severity using the Derkay laryngoscopic scale. MATERIALS AND METHODS: The data and biopsies from 36 patients with Juvenile (JRRP) and 56 patients with Adult (ARRP) were collected and analyzed under light microscopy. The patients were separated into groups according to the Derkay index: ≥20 for the most severe and < 20 for the less severe cases. Immunohistochemical analysis using CD3, CD4, CD8, CD15, CD20, CD68, FoxP3 and MUM-1 antibodies was performed, and the inflammatory cells were quantified. All the clinicopathological characteristics and the results of the immunohistochemical analysis were compared among the groups proposed using the Chi-Square test and correlated through the Spearman correlation test. RESULTS: The ARRP showed significantly higher quantities of CD3+, CD8+ and MUM1+ cells (p < .05) than the JRRP samples. The presence of CD15+ cells showed positive correlation with the Derkay index (p < .05), while the MUM-1+ cells showed an inverse correlation (p = .01). CONCLUSION: There are differences between the inflammatory cells population in the juvenile and adult groups and it can be related to disease severity.

Molecular carcinogenesis in equine penile cancer: A potential animal model for human penile cancer.

OBJECTIVES: To evaluate the expression of COX-2, E-cadherin, vimentin, 14-3-3σ, and Phosphatase and tensin homolog (PTEN) tumor-related proteins in equine penile papillomas (ePP) and squamous cell carcinomas (ePSCC), the occurrence of epithelial-mesenchymal transition (EMT) at the invasion front (IF) and compare our findings with current knowledge on human penile squamous cell carcinoma (hPSCC). MATERIAL AND METHODS: We analyzed, by immunohistochemistry in 45 equine penile proliferative epithelial lesions, the expression of COX-2, E-cadherin, vimentin, 14-3-3σ, and PTEN using monoclonal antibodies. Tumors were histopathologically classified as well-differentiated or poorly differentiated using the IF grading scheme. Semiquantitative analysis was performed to determine down or up-regulation of the proteins and association with histopathological characteristics were statistically investigated using Mann-Whitney U test and/or Spearman's tests. RESULTS: COX-2 was neo-expressed in 86.6% of the cases and expression progressively increased from ePP to ePSCC (P = 0.0003) and from well to poorly differentiated (P = 0.033). High COX-2 expression was associated with a high mitotic index (MI) (P = 0.026). In contrast to normal epidermis, ePSCC had very low E-cadherin expression in 64% of the cases (P = 0.0005). Vimentin was neo-expressed in 65% of poorly differentiated ePSCC at the IF indicating EMT. Cytoplasmic 14-3-3σ protein expression was reduced in 42% of the ePSCC and additionally, nuclear expression of 14-3-3σ in neoplastic keratinocytes and in the cytoplasm of stromal fibroblasts at the IF was features only found in ePSCC. PTEN protein showed a tendency to be decreased or lost in ePSCC. CONCLUSIONS: Our study provides evidence of molecular abnormalities in ePSCC similar to those reported for human PSCC. The occurrence of EMT at the IF is a common event in ePSCC. Naturally occurring ePSCC could serve as a valuable preclinical animal model to explore upcoming therapeutic options for hPSCC.

Oral fibropapillomatosis and epidermal hyperplasia of the lip in newborn lambs associated with bovine Deltapapillomavirus.

Congenital fibropapillomatosis of the gingiva and oral mucosa and epidermal hyperplasia of the lip are described, for the first time, in two newborn lambs. Expression of the E5 oncoprotein of bovine deltapapillomavirus types 2 (BPV-2) and -13 (BPV-13) was detected in both fibropapillomas and the hyperplastic epidermal cells suggesting the BPV infection was the cause of the proliferative lesions. No DNA sequences of BPV-1 and BPV-14 were detected. Both BPV-2 and BPV-13 DNA were also amplified from peripheral blood mononuclear cells (PBMCs) of the newborn lambs' dams. The concordance between BPV genotypes detected in the blood of dam and the oral and skin pathological samples of their offspring suggests that a vertical hematogeneous transmission was most likely source of BPV infection. Immunoblotting revealed the presence of E5 dimers allowing the viral protein to be biologically active. E5 dimers bind and activate the platelet derived growth factor ß receptor (PDGFßR), a major molecular mechanism contributing to disease. The detection of E5 protein within the proliferating cells therefore adds further evidence that the BPV infection was the cause of the proliferative lesions seen in these lambs. This is the first evidence of vertical transmission of BPVs in sheep resulting in a clinical disease.

Increased expression of hypoxia-inducible factor-1 alpha and its impact on transcriptional changes and prognosis in malignant tumours of the ocular adnexa.

PURPOSE: To investigate the expression profile of the hypoxia-inducible transcription factor-1α (HIF-1α) and its downstream targets in malignancies of the ocular adnexa and to determine its relevance as a prognostic factor for clinical outcome. METHODS: We included 49 subjects with malignant tumours (25 squamous cell carcinomas (SCC), 15 non-Hodgkin lymphomas, 9 melanomas) and 30 patients with benign tumours of the ocular adnexa (13 papillomas, 7 reactive lymphoid hyperplasias (RLHs) and 10 nevi) as controls. We quantified HIF-1α protein expression by immunohistochemistry and assessed the association between HIF-1α and clinical outcome via Kaplan-Meier analysis. Furthermore, we assessed the expression of HIF-1α downstream factors by transcriptional sequencing using the MACE (massive analysis of cDNA ends) technology. RESULTS: SCCs revealed a strong HIF-1α expression in 61% of tumour cells in comparison with only 22% in papillomas (p < 0.0001). In contrast, malignant melanomas and lymphomas revealed a similar HIF-1α expression compared with nevi and RLHs. Transcriptional sequencing and Gene Ontology Cluster analysis demonstrated 37 hypoxia-associated factors, including HIF-1α, VEGF, SFRP1 and LOXL2 that are significantly increased in SCC and may contribute to tumour proliferation, angiogenesis, and metastasis. Association analysis between HIF-1α immunoreactivity and clinical outcome revealed a trend towards an unfavourable prognosis in malignant tumours with increased HIF-1α expression. CONCLUSIONS: HIF-1α protein is increased in malignant tumours of the ocular adnexa, which is associated with an increase in multiple HIF-1α-downstream factors and a trend towards an unfavourable clinical outcome.

Differential Role of the RasGEFs Sos1 and Sos2 in Mouse Skin Homeostasis and Carcinogenesis.

Using Sos1 knockout (Sos1-KO), Sos2-KO, and Sos1/2 double-knockout (Sos1/2-DKO) mice, we assessed the functional role of Sos1 and Sos2 in skin homeostasis under physiological and/or pathological conditions. Sos1 depletion resulted in significant alterations of skin homeostasis, including reduced keratinocyte proliferation, altered hair follicle and blood vessel integrity in dermis, and reduced adipose tissue in hypodermis. These defects worsened significantly when both Sos1 and Sos2 were absent. Simultaneous Sos1/2 disruption led to severe impairment of the ability to repair skin wounds, as well as to almost complete ablation of the neutrophil-mediated inflammatory response in the injury site. Furthermore, Sos1 disruption delayed the onset of tumor initiation, decreased tumor growth, and prevented malignant progression of papillomas in a DMBA (7,12-dimethylbenz[α]anthracene)/TPA (12-O-tetradecanoylphorbol-13-acetate)-induced skin carcinogenesis model. Finally, Sos1 depletion in preexisting chemically induced papillomas resulted also in decreased tumor growth, probably linked to significantly reduced underlying keratinocyte proliferation. Our data unveil novel, distinctive mechanistic roles of Sos 1 and Sos2 in physiological control of skin homeostasis and wound repair, as well as in pathological development of chemically induced skin tumors. These observations underscore the essential role of Sos proteins in cellular proliferation and migration and support the consideration of these RasGEFs as potential biomarkers/therapy targets in Ras-driven epidermal tumors.

Clinical Significance of Low 2-Methoxyestradiol Levels in Serum and Tissue of Recurrent Juvenile-Onset Laryngeal Papillomatosis.

Objective We aim to explore the correlation between serum and tissue 2-methoxyestradiol (2-ME-2) levels and recurrence of juvenile-onset respiratory papillomatosis (JORRP). Study Design Retrospective cohort studies. Settings Laboratory of Otolaryngology, Department of Head and Neck Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University. Subjects and Methods Sixty-four patients diagnosed with JORRP in our department from January 2007 to December 2012 were enrolled. Patients were divided into recurrence and nonrecurrence groups, with 32 patients in each group. ELISA detected the concentration of 2-ME-2 in serum and tissue samples collected during the first surgical procedure. Mann-Whitney analysis, receiver operating characteristic curves, logistic regression model, and Kaplan-Meier method were used for data processing. Results There was no difference in the serum 2-ME-2 concentration between the groups ( P = .237), while the tissue 2-ME-2 concentration of the recurrent group was significantly lower than that of the nonrecurrence group ( P = .0001). When the area under the curve was 0.752, the cutoff value of tissue 2-ME-2 at 670.02 pg/mL yielded the highest predictive sensitivity (71.9%) and specificity (71.9%). Regrouped by this cutoff point, patients with a lower tissue 2-ME-2 level (n = 26) had shorter disease-free survival and a higher recurrence odds ratio than patients with a higher tissue 2-ME-2 level (n = 38; P = .0408, odds ratio = 7.667). Conclusion A low tissue 2-ME-2 level is associated with a higher recurrence rate of JORRP. Tissue 2-ME-2 may be an effective target for JORRP treatment and a convenient measure for recurrence monitoring.

Association of Epithelial Atypia With Recurrence After Surgical Excision in Conjunctival Papilloma.

PURPOSE: To investigate the association between recurrence of conjunctival papillomas and presence of atypical epithelial changes in patients undergoing surgical excision for conjunctival papilloma. METHODS: We retrospectively reviewed 1,195 ophthalmic pathology specimens from 2004 to 2014 at Ichikawa General Hospital. Pathologic specimens of 5 patients with a final diagnosis of "conjunctival papilloma" were stained with hematoxylin-eosin, Ki 67, p53, human papillomavirus (HPV) 16 and 18 antibodies. RESULTS: Of 1,195 patients, 5 patients (4 men, 1 woman; age range: 27∼57 years, mean age: 38.4 years) had a diagnosis of conjunctival papilloma, which constituted to 0.42% of the pathologic diagnosis made for the ophthalmology specimens. All specimens displayed multiple fronds of thickened conjunctival epithelium that enclosed cores of vascularized connective tissues. Three patients with recurrence after surgical excision demonstrated moderate to severe epithelial atypia, who also showed higher staining with Ki67 and p53 compared with patients with no recurrence. HPV16 and 18 antibodies staining did not appear to relate to recurrences. CONCLUSIONS: Conjunctival papillomas with higher positive staining for Ki67 and p53 seem to have a higher risk of recurrence even after complete surgical excision and necessitate careful follow-up.