Cutaneous Human Papillomavirus Infection and Development of Subsequent Squamous Cell Carcinoma of the Skin

The role of cutaneous human papillomavirus (HPV) infection in the development of subsequent cutaneous squamous cell carcinoma (SCC) is unknown. Pathologically confirmed cases of SCC (n = 150) enrolled in a previously conducted case-control study were included in a retrospective cohort study to examine the association of cutaneous HPV at the time of SCC diagnosis with the risk of subsequent SCC development. Data on HPV seropositivity, HPV DNA in eyebrow hairs (EB) and SCC tumors were available from the parent study. Incidence of subsequent SCC was estimated using person-years of follow up. Cox Proportional Hazards ratios were estimated to evaluate the associations of both, HPV seropositivity and HPV DNA positivity with subsequent SCC. The five year cumulative incidence of subsequent SCC was 72%. Seropositivity to cutaneous HPV was not associated with the risk of subsequent SCC (HR = 0.83, 95% CI = 0.41-1.67). Any beta HPV infection in EB was associated with reduced risk (HR = 0.30, 95% CI = 0.11-0.78) of subsequent SCC among cases who were positive for beta HPV DNA in tumor tissue. Infection with beta HPV type 2 (HR = 0.32, 95% CI = 0.12-0.86) in EB was associated with reduced risk of subsequent SCC among HPV DNA positive SCCs. In conclusion, beta HPV infection was inversely associated with the risk of subsequent SCC.

Abstract A2-25: Identification of RASA1 as a novel melanoma tumor suppressor gene

Hyperactivation of the Ras-Raf-Mitogen-activated protein kinase (MAPK) pathway has been commonly observed in melanoma via frequent activating mutations in NRAS and BRAF. Novel mutations in other components of this pathway such as MEK1, MEK2, MAP3K5, and MAP3K9 have been reported recently by high-throughput sequencing efforts. In addition, NF1 (neurofibromatosis type 1), one of the Ras GTPase activating proteins (RasGAPs) that negatively regulate Ras, has been shown to be mutated or suppressed in melanoma. However, importance of other RasGAPs has not been addressed in melanoma.

To obtain a comprehensive view of melanoma genomes, we conducted whole genome sequencing (WGS) of 15 metastatic melanomas and matched normal PBMC genomes from 13 melanoma patients. All melanoma genomes from these 13 patients contained at least one mutation in genes of Ras-Raf-MAPK pathway (MAPK1, MAP3K1, MAP4K2, MAP3K14, NRAS, and BRAF). In addition, we identified two novel, clustered somatic missense mutations (p.Tyr472His and p.Leu481Phe) in RASA1 (RAS p21 protein activator 1, p120RasGAP). In this study, we addressed functional roles of RASA1 in melanoma tumorigenesis. The RNAi-mediated down-regulation of RASA1 promoted, while ectopic expression of wild type RASA1 decreased, anchorage-independent colony formation, tumor growth, and RAS activation. Interestingly, RASA1 Y472H mutant enhanced soft agar colony formation and tumor growth, while RASA1 L481F mutant lost its tumor suppressive activity. Mechanistically, RASA1 required RasGAP activity to suppress colony formation and showed higher activity toward R-Ras (related RAS viral (r-ras) oncogene homolog) isoform among the Ras superfamily of small GTPases. In addition, RASA1 suppressed Ral-A among Ras downstream effectors. Interestingly, RASA1 expression was frequently down-regulated in metastatic melanoma samples (11.4% (4/35) of lymph node metastasis and 3.4% (1/29) of distal metastases) compared to primary melanomas (33.3% (21/63)) and dysplastic nevi (44.1% (15/34)). We also observed significantly shorter overall survival of melanoma patients with BRAF mutations when RASA1 mRNA expression is low. Thus, these data support that RASA1 is a novel melanoma tumor suppressor that is inactivated by suppressed expression or by mutation.

Citation Format: Hyeran Sung, Krishna L. Kanchi, Jane Messina, Ji-Hyun Lee, Youngchul Kim, Li Ding, Richard K. Wilson, Jeffrey S. Weber, Minjung Kim. Identification of RASA1 as a novel melanoma tumor suppressor gene. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A2-25.

Merkel cell polyomavirus (MCV) T-antigen seroreactivity, MCV DNA in eyebrow hairs, and squamous cell carcinoma

Background

The role of Merkel cell polyomavirus (MCV) infection in the etiology of non-melanoma skin cancers, other than Merkel cell carcinoma, is unclear. Previously, we reported a significant association between seropositivity to MCV capsid antigen and MCV DNA-positive cutaneous squamous cell carcinoma (SCC). Here we present associations between SCC and seroreactivity to MCV T-antigen (T-Ag) oncoprotein, as well as MCV DNA detected in eyebrow hairs.

Findings

A clinic-based case–control study, including 171 SCC cases and 300 controls without skin cancer, was conducted at Moffitt Cancer Center in Tampa, Florida. Multiplex assays were used to measure serum antibodies against MCV small and large T-Ag and MCV DNA in both eyebrow hairs and SCC tumors (n = 144). Odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated using logistic regression to evaluate the associations between MCV and SCC. No significant association was observed between seroreactivity to MCV full-length large or small T-Ag and SCC, overall [OR_{large T-Ag} = 0.99 (0.48-2.08), OR_{small T-Ag} = 0.31 (0.06–1.62)] or when comparing tumor MCV DNA-positive cases to controls [OR_{large T-Ag} = 1.06 (0.38–2.93)]. Only presence of MCV DNA in eyebrow hairs was significantly associated with MCV DNA-positive SCC [OR = 4.05 (2.01–8.18)].

Conclusion

MCV infection is unlikely to play a direct role in SCC.

Abstract A05: Identification of RASA1 as a novel melanoma tumor suppressor gene

Hyperactivation of the Ras-Raf-Mitogen-activated protein kinase (MAPK) pathway via frequent activating mutations in NRAS and BRAF has been commonly observed in melanoma. Novel mutations in other components of this pathway such as MEK1, MEK2, MAP3K5, and MAP3K9 have been reported recently by high-throughput sequencing efforts. In addition, NF1 (neurofibromatosis type 1), one of the Ras GTPase activating proteins (RasGAPs), has been shown to be mutated or suppressed in melanoma. However, importance of other RasGAPs has not been addressed in melanoma.

To obtain a comprehensive view of melanoma genomes, we conducted whole genome sequencing (WGS) of 15 metastatic melanomas and matched normal PBMC genomes from 13 melanoma patients. All melanoma genomes from these 13 patients contained at least one mutation in genes of Ras-Raf-MAPK pathway (MAPK1, MAP3K1, MAP4K2, MAP3K14, NRAS, and BRAF). In addition, we identified two novel, clustered somatic missense mutations (p.Tyr472His and p.Leu481Phe) in RASA1 (RAS p21 protein activator 1, p120RasGAP) that negatively regulates Ras by catalyzing the hydrolysis of active Ras-GTP to inactive Ras-GDP. In this study, we addressed functional roles of RASA1 in melanoma tumorigenesis. Ectopic expression of wild-type RASA1 in human melanoma cell lines SKMEL28 and WM983C (with BRAF V600E) decreased, while RASA1 Y472H mutant enhanced soft agar colony formation, tumor growth, and Ras activity. The RASA1 L481F mutant lost its tumor suppressive activity. The siRNA- or shRNA-mediated knockdown of RASA1 promoted soft agar colony formation, tumor growth, and RAS activation in human melanoma cell lines IGR1 and KML1 (with BRAFV600E). Mechanistically, RASA1 required RasGAP activity to suppress colony formation and showed higher activity toward R-Ras isoform among Ras superfamily of small GTPases. To determine RASA1 level in melanocytic lesions, immunohistochemical analysis of RASA1 on human melanoma tissue microarray (TMA) was performed. RASA1 expression was frequently down-regulated in metastatic melanoma samples (11.4% (4/35) of lymph node metastasis and 3.4% (1/29) of distal metastases) compared to primary melanomas (33.3% (21/63)) and dysplastic nevi (44.1% (15/34)). Thus, these data support that RASA1 is a novel melanoma tumor suppressor that is inactivated by loss of expression or by mutation.

Citation Format: Hyeran Sung, Krishna L. Kanchi, Jane Messina, Ji-Hyun Lee, Li Ding, Richard K. Wilson, Jeffrey S. Weber, Minjung Kim. Identification of RASA1 as a novel melanoma tumor suppressor gene. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Melanoma: From Biology to Therapy; Sep 20-23, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(14 Suppl):Abstract nr A05.

Clinical validation of a gene expression signature that differentiates benign nevi from malignant melanoma

BACKGROUND

Histopathologic examination is sometimes inadequate for accurate and reproducible diagnosis of certain melanocytic neoplasms. As a result, more sophisticated and objective methods have been sought. The goal of this study was to identify a gene expression signature that reliably differentiated benign and malignant melanocytic lesions and evaluate its potential clinical applicability. Herein, we describe the development of a gene expression signature and its clinical validation using multiple independent cohorts of melanocytic lesions representing a broad spectrum of histopathologic subtypes.

METHODS

Using quantitative reverse-transcription polymerase chain reaction (PCR) on a selected set of 23 differentially expressed genes, and by applying a threshold value and weighting algorithm, we developed a gene expression signature that produced a score that differentiated benign nevi from malignant melanomas.

RESULTS

The gene expression signature classified melanocytic lesions as benign or malignant with a sensitivity of 89% and a specificity of 93% in a training cohort of 464 samples. The signature was validated in an independent clinical cohort of 437 samples, with a sensitivity of 90% and specificity of 91%.

CONCLUSIONS

The performance, objectivity, reliability and minimal tissue requirements of this test suggest that it could have clinical application as an adjunct to histopathology in the diagnosis of melanocytic neoplasms.

STIM1- and Orai1-mediated Ca(2+) oscillation orchestrates invadopodium formation and melanoma invasion

Calcium signaling mediated by STIM1 and Orai1 activates Src to promote invadopodium assembly while simultaneously promoting MT1-MMP recycling to the plasma membrane to promote ECM degradation.

Ca²⁺ signaling has been increasingly implicated in cancer invasion and metastasis, and yet, the underlying mechanisms remained largely unknown. In this paper, we report that STIM1- and Orai1-mediated Ca²⁺ oscillations promote melanoma invasion by orchestrating invadopodium assembly and extracellular matrix (ECM) degradation. Ca²⁺ oscillation signals facilitate invadopodial precursor assembly by activating Src. Disruption of Ca²⁺ oscillations inhibited invadopodium assembly. Furthermore, STIM1 and Orai1 regulate the proteolysis activity of individual invadopodia. Mechanistically, Orai1 blockade inhibited the recycling of MT1–matrix metalloproteinase (MMP) to the plasma membrane and entrapped MT1-MMP in the endocytic compartment to inhibit ECM degradation. STIM1 knockdown significantly inhibited melanoma lung metastasis in a xenograft mouse model, implicating the importance of this pathway in metastatic dissemination. Our findings provide a novel mechanism for Ca²⁺-mediated cancer cell invasion and shed new light on the spatiotemporal organization of store-operated Ca²⁺ signals during melanoma invasion and metastasis.

Abstract PR09: Genetic interaction of NEDD9 with melanoma-prone oncogenes and tumor suppressor genes

Mouse models have proven their utility in establishing causal roles and addressing genetic interactions of candidate alterations in tumorigenesis. Previously, our cross-species comparison of human and mouse melanoma genomes led to the identification of NEDD9 (Neural precursor cell Expressed, Developmentally Down-regulated 9) as a novel melanoma metastasis gene that is up-regulated in 35~50% of metastatic melanomas. We have shown that NEDD9 enhances proliferation and drives invasion in vitro and lung seeding in vivo of melanoma cells. In this study, to explore the biological roles of NEDD9 in melanoma tumorigenesis, we have generated tet-inducible NEDD9 mouse model that carries a doxycycline-responsive, melanocyte-targeted NEDD9. Two independent transgenic founder lines (line A and D) were obtained and genetic interaction of NEDD9 with melanoma-prone oncogenes and tumor suppressor genes have been tested.

Melanoma displays frequent activation of NRAS and BRAF and inactivation of CDKN2A (INK4A/ARF) and PTEN. First, we asked whether NEDD9 cooperates with RAS/RAF/MAPK pathway activation by crossing Nedd9 alleles onto the non-metastatic Tyr-RAS* Ink4a/Arf-/- melanoma model to establish a colony of compound mutant mice designated as “iNEDD9” (e.g. Tyr-HRAS*;Tyr-rtTA/Tet-NEDD9;Ink4a/Arf-/-). These mice developed spontaneous cutaneous nodular type melanomas and ocular melanomas indistinguishable from the ones developed in Tyr-RAS* Ink4a/Arf-/- model. In these mice, NEDD9 expression in melanocytes via doxycycline administration led to decreased tumor latency (Median latency: 88 (NEDD9 ON) vs. 120 (NEDD9 OFF) days (p=0.041, log-rank test)) and increased tumor initiation without signs of metastasis. Median melanoma-free survival of iNEDD9 mice was 111 (line A, p=0.009, log-rank test) and 114.5 (line D, p=0.032) days, lower than 166 days observed in control mice without NEDD9. This data supports the cooperation of NEDD9 with RAS/RAF/MAPK pathway activation in melanoma tumorigenesis. Secondly, we addressed whether NEDD9 can synergize with loss of PTEN and INK4a/ARF in vitro and in vivo. We observed that NEDD9 cooperated with PTEN loss in Ink4a/Arf-/- melanocytes without activating RAS or RAF mutation and enhanced proliferation, anchorage independent growth, and invasion in vitro and tumor growth in nude mice. NEDD9 expression correlated with increased phosphorylation of SFKs (Src family kinases), AKT2, and STAT3. To analyze the biological consequence of NEDD9 expression in vivo, we generated a mouse model based on loss of PTEN and CDKN2A (INK4A/ARF) with or without NEDD9 up-regulation designated as “NIP” (e.g. Tyr-CreERT2;Tyr-rtTA/Tet-NEDD9;cInk4a/ArfL/L;cPtenL/L). These mice developed cutaneous and ocular melanomas following tamoxifen treatment, which are under characterization.

This study will generate a body of knowledge for the in vivo roles of NEDD9 in melanoma tumorigenesis and invaluable melanoma models driven by genetic lesions observed in human melanoma patients. Since most of the current mouse melanoma models are driven by activating mutations in NRAS or BRAF genes, our model may provide a novel opportunity to understand melanomas without these mutations.

This abstract is also presented as Poster B04.

Citation Format: Hyeran Sung, Jong Woo Lee, Gretchen Alicea, Ji-Hyun Lee, Jane Messina, Scott Granter, Lynda Chin, Minjung Kim. Genetic interaction of NEDD9 with melanoma-prone oncogenes and tumor suppressor genes. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr PR09.

Analysis of tumor mitotic rate in thin metastatic melanomas compared with thin melanomas without metastasis using both the hematoxylin and eosin and anti-phosphohistone 3 IHC stain

Studies have suggested that elevated tumor mitotic rate (MR) is linked to overall survival in thin melanoma. Recently, promising data regarding anti-phosphohistone 3 (pHH3) immunohistochemistry and its ability to aid in calculation of MR have emerged. The authors retrospectively analyzed original biopsies from 13 thin melanomas with positive sentinel node (SN) status and 16 thin melanomas with negative SN status. Both anti-pHH3 immunohistochemistry and the hematoxylin and eosin (H&E) stain were used to evaluate MR by 2 dermatopathologists blinded to SN status using the "hot spot" method. Intraclass coefficient values were attained to measure interobserver concordance and reliability of the pHH3 stain. By generating a receiver operating characteristic curve and analyzing the overall area under the curve, pHH3 was found to have good interobserver reliability. The relationship between MR and SN involvement was also evaluated, but this correlation was not statistically significant.

Implementation of the ‘Sapere Migliora’ information aid for newly diagnosed people with multiple sclerosis in routine clinical practice: a late-phase controlled trial

Background:

The SIMS-Trial showed that the ‘Sapere Migliora’ information aid (IA) for newly diagnosed people with multiple sclerosis (PwMS) effectively improved patient knowledge and satisfaction with care.

Objectives:

The objectives of this paper are to assess the effectiveness of the IA in clinical practice and to compare the whole IA with the take-home booklet/website component alone.

Methods:

After updating the IA and replacing the CD with a website, a prospective, open-label non-randomised controlled trial compared the whole IA (group A, five SIMS-Trial centres) to take-home (group B, 16 centres). One month after the intervention, participants completed the MS Knowledge Questionnaire (MSKQ), care satisfaction questionnaire (COSM-R) (primary study outcomes), Hospital and Anxiety Depression Scale, and ad hoc questionnaire appraising the IA.

Results:

We enrolled 159 newly diagnosed PwMS (May 2012–March 2013). Drop-outs were four of 77 (5%, group A) and 11/82 (13%, group B). Primary endpoint (highest tertile both for MSKQ and COSM-R section 2 scores) was achieved by 38/77 (49%) group A and 33/82 (40%) group B ( p = 0.25). Attainment of secondary outcomes was also similar between groups.

Conclusions:

This study shows that the entire IA is not superior to the booklet/website alone, and that both are comparable in efficacy to the intervention arm of the SIMS-Trial.

Trial registration number:

ISRCTN78940214.

Anatomical Description of the Dorsal Capsulo-Scapholunate Septum (DCSS)-Arthroscopic Staging of Scapholunate Instability after DCSS Sectioning

Background The dorsal capsuloligamentous scapholunate septum (DCSS) is a confluence of the dorsal capsule, the dorsal intercarpal ligament (DIC), and the scapholunate interosseous ligament (SLIOL). It appears to play a role in the stability of the scapholunate articulation. The purpose of this study was to describe the anatomical basis for this structure and to investigate its role in scapholunate instability through sectioning of this structure followed by an arthroscopic and fluoroscopic analysis. Material and Methods In the anatomical part of the study we dissected 3 fresh cadaver wrists to examine the anatomy of the DCSS. In the arthroscopic part of the study we assessed the EWAS grade of SL instability before and after sectioning the DCSS and measured the scapholunate and radiolunate angles fluoroscopically. Results Sectioning the DCSS increased the EWAS grade of SL instability but did not affect the scapholunate gap, the scapholunate angle or radiolunate angle. Conclusion We have demonstrated that there is a distinct structure that is separate from the dorsal capsule, which we have labeled the Dorsal Capsuloligamentous Scapholunate Septum. We believe that the DCSS is a previously unreported secondary stabilizer of the SL joint which may have therapeutic and prognostic implications.