Quantitative Proteome Analysis Reveals Increased Content of Basement Membrane Proteins in Arteries From Patients With Type 2 Diabetes Mellitus and Lower Levels Among Metformin Users

BACKGROUND

The increased risk of cardiovascular diseases in type 2 diabetes mellitus has been extensively documented, but the origins of the association remain largely unknown. We sought to determine changes in protein expressions in arterial tissue from patients with type 2 diabetes mellitus and moreover hypothesized that metformin intake influences the protein composition.

METHODS AND RESULTS

We analyzed nonatherosclerotic repair arteries gathered at coronary bypass operations from 30 patients with type 2 diabetes mellitus and from 30 age- and sex-matched nondiabetic individuals. Quantitative proteome analysis was performed by isobaric tag for relative and absolute quantitation-labeling and liquid chromatography-mass spectrometry, tandem mass spectrometry analysis on individual arterial samples. The amounts of the basement membrane components, α1-type IV collagen and α2-type IV collagen, γ1-laminin and β2-laminin, were significantly increased in patients with diabetes mellitus. Moreover, the expressions of basement membrane components and other vascular proteins were significantly lower among metformin users when compared with nonusers. Patients treated with or without metformin had similar levels of hemoglobin A1c, cholesterol, and blood pressure. In addition, quantitative histomorphometry showed increased area fractions of collagen-stainable material in tunica intima and media among patients with diabetes mellitus.

CONCLUSIONS

The distinct accumulation of arterial basement membrane proteins in type 2 diabetes mellitus discloses a similarity between the diabetic macroangiopathy and microangiopathy and suggests a molecular explanation behind the alterations in vascular remodeling, biomechanical properties, and aneurysm formation described in diabetes mellitus. The lower amounts of basement membrane components in metformin-treated individuals are compatible with the hypothesis of direct beneficial drug effects on the matrix composition in the vasculature.

The wound inflammatory response exacerbates growth of pre-neoplastic cells and progression to cancer

There is a long-standing association between wound healing and cancer, with cancer often described as a "wound that does not heal". However, little is known about how wounding, such as following surgery, biopsy collection or ulceration, might impact on cancer progression. Here, we use a translucent zebrafish larval model of Ras(G12V)-driven neoplasia to image the interactions between inflammatory cells drawn to a wound, and to adjacent pre-neoplastic cells. We show that neutrophils are rapidly diverted from a wound to pre-neoplastic cells and these interactions lead to increased proliferation of the pre-neoplastic cells. One of the wound-inflammation-induced trophic signals is prostaglandin E2 (PGE2). In an adult model of chronic wounding in zebrafish, we show that repeated wounding with subsequent inflammation leads to a greater incidence of local melanoma formation. Our zebrafish studies led us to investigate the innate immune cell associations in ulcerated melanomas in human patients. We find a strong correlation between neutrophil presence at sites of melanoma ulceration and cell proliferation at these sites, which is associated with poor prognostic outcome.

Abstract 4303: Programmed death ligand 1 (PD-L1) expression in paired melanoma tumor samples

Background: There is limited information on changes in PD-L1 expression levels over time in melanoma.

Methods: PD-L1 expression was measured in melanoma tumor samples collected at different time points from the same patient using a prototype immunohistochemistry (IHC) assay with the 22C3 antibody. PD-L1 positivity was defined as staining in ≥1% of cells. The concordance of PD-L1 expression in paired samples was analyzed by treating the IHC proportion score as a continuous variable or classifying staining as positive or negative.

Results: 48 patients were included. Median age was 65 years (range, 23-85), 73% were male, and 60% had stage I-IIIA disease. All first samples and 85% of second samples were surgical samples. The median interval between sample collection dates was 25.3 months (range, 3.1-203.5). There was no statistically significant correlation of the PD-L1 IHC proportional score between paired samples (Pearson correlation coefficient, 0.13). 40% of patients had an increased proportion score at the second time point, and 10% had a decreased score. The prevalence of PD-L1 positivity was 31% in first samples and 46% in second samples. The concordance rate was 65% (95% CI, 49%-78%) when PD-L1 expression was categorized as positive or negative (Table). The concordance rate was similar in paired samples collected within and beyond 2 years.

Concordance of PD-L1 Expression in Paired Melanoma Samples (N = 48)Later Time PointPD-L1 ExpressionPositive, n (%)Negative, n (%)Earlier Time PointPositive10 (20.8)5 (10.4)Negative12 (25.0)21 (43.7)

Conclusion: Our preliminary analysis did not suggest a significant correlation of PD-L1 expression in paired melanoma samples collected at different time points. Similar results were observed when samples were categorized as PD-L1 positive or PD-L1 negative. The 35% discordance rate between initial and subsequent tumor samples should be considered if PD-L1 expression is used for selection of enrollment in clinical trials.

Citation Format: Torben Steiniche, Allan Vestergaard Danielsen, Zhen (Adelle) Wang, Patricia Switten Nielsen, Lars Bastholt, Henrik Schmidt, Inge Marie Svane, Marisa Dolled-Filhart, Kenneth Emancipator, Dianna Y. Wu, Michael Busch-Sorensen, Wei Zhou. Programmed death ligand 1 (PD-L1) expression in paired melanoma tumor samples. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4303. doi:10.1158/1538-7445.AM2015-4303

In-situ hybridization-based quantification of hTR: a possible biomarker in malignant melanoma

AIMS

Telomerase is reactivated in most cancers and there is accumulating evidence that this is a driver event in malignant melanoma (MM). Thus, our aim was to evaluate if in-situ hybridization (ISH)-based quantification of telomerase RNA (hTR) could be used to distinguish MM from naevi, and if there was a correlation with the Breslow thickness.

RESULTS AND METHODS

We created a tissue microarray (TMA) from formalin-fixed and paraffin-embedded tissue samples from 17 MM and 23 naevi, performed ISH targeting hTR, and quantified the signals. We found a more than eightfold greater number of hTR signals per nucleus in the MM samples compared to the naevi, and a positive correlation (P = 0.0381) between the number of hTR signals per nucleus and the Breslow thickness.

CONCLUSION

Quantification of hTR ISH signals clearly distinguish MM from naevi (P < 0.0001) and the number of signals per nucleus correlates with the Breslow thickness, suggesting that hTR might be a valuable biomarker in MM. Furthermore, as ISH-based detection requires the presence of both hTR and telomerase reverse transcriptase (hTERT), it might be an indicator of active telomerase and thus have future relevance as a predictive biomarker for anti-telomerase treatment.

Human papillomavirus and the incidence of nonmelanoma and melanoma skin cancer using cervical conization as a surrogate marker: a nationwide population-based Danish cohort study

PURPOSE

Human papillomavirus' (HPV's) role in skin cancer is controversial. To examine whether an individual is prone to develop a chronic oncogenic infection, we conducted a nationwide population-based cohort study of the risk of skin cancer after another HPV-related neoplasia-that is, cervical high-grade dysplasia or carcinoma-using cervical conization as a surrogate marker.

METHODS

Using Danish registries, we identified all women who underwent conization from 1978 to 2011 (n = 87,164) and followed them until first-time skin cancer diagnosis, death, emigration, or 31 December 2011, whichever came first. We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and malignant melanoma (MM) according to national incidence rates.

RESULTS

The 1-year absolute risks were 0.0012%, 0.045%, and 0.029% for SCC, BCC, and MM, respectively. Conization was clearly associated with increased incidence of SCC (SIR = 1.37; 95% CI: 1.13-1.65), but not MM (SIR = 1.00; 95% CI: 0.91-1.11). BCC risk was slightly increased (SIR = 1.08; 95% CI: 1.02-1.13).

CONCLUSIONS

The association between conization and cutaneous SCC provides evidence for conization as a marker of underlying general susceptibility to oncogenic HPV.

Aldara®-induced skin inflammation: studies of patients with psoriasis

BACKGROUND

The application of Aldara(®) cream containing 5% imiquimod stimulates Toll-like receptor 7/8 on plasmacytoid dendritic cells, thereby producing a potent immunomodulatory effect. This has been reported to trigger psoriasis.

OBJECTIVES

To establish a human model of Aldara-induced psoriasis-like skin inflammation in patients with psoriasis.

METHODS

Nonlesional psoriatic skin of 13 patients was treated with Aldara for 2 or 7 days. The skin was evaluated clinically and histologically on days 2, 4 and 7. Cytokine expression in Aldara-treated, lesional and nonlesional psoriatic skin was compared using reverse-transcription quantitative polymerase chain reaction.

RESULTS

Nine of the 10 patients receiving application of Aldara under occlusion for 2 days developed redness, induration and scaling. Histological analysis revealed focal parakeratosis, acanthosis and perivascular mononuclear infiltration. On days 4 and 7 both clinical and histological signs of inflammation subsided. Two of the three patients treated with Aldara for 7 days developed erosions leading to psoriasis on day 21. Cytokine markers of activation of the innate immune system [interferon-α, interferon regulatory factor-7 and interleukin (IL)-1β] were equally expressed in lesional and Aldara-treated skin (n = 6). IL-6 and tumour necrosis factor-α were preferentially expressed in Aldara-treated skin. Adaptive immune system activation occurred only partially: IL-23p19 and IL-22 were similarly overexpressed in Aldara-treated and lesional psoriatic skin, but IL-17A and IL-12p40 were significantly underexpressed in Aldara-treated skin compared with lesional psoriatic skin. IL-10 was significantly overexpressed in Aldara-treated skin.

CONCLUSIONS

We were able to induce psoriasis-like skin inflammation although typical psoriasis did not develop, possibly due to incomplete adaptive immune system recruitment and the powerful stimulation of IL-10 counter-regulation.

Prognostic stratification of ulcerated melanoma: not only the extent matters

OBJECTIVES

For patients with melanoma, ulceration is an important prognostic marker and interestingly also a predictive marker for the response of adjuvant interferon. A consensual definition and accurate assessment of ulceration are therefore crucial for proper staging and clinical management. We evaluated the prognostic impact of the extent and type of ulceration and the epidermal involvement theoretically preceding it (consumption of epidermis and cleft formation) or seen subsequent to the inflammation (reepithelialization and reactive epidermal hyperplasia), aiming for better prognostic stratification of ulcerated lesions.

METHODS

From H&E-stained sections, the status (presence vs absence), extent (percentage of the total tumor length), and type (infiltrative vs attenuative) of ulceration and epidermal involvement were evaluated from 385 patients with cutaneous melanoma.

RESULTS

The presence of ulceration (hazard ratio [HR], 1.83), an attenuative type of ulceration (HR, 3.02), and excessive ulceration (HR, 3.57) were independent predictors of poor melanoma-specific survival. Further subdivision of minimal/moderate ulceration showed independent prognostic value only for lesions with epidermal involvement of the surrounding epidermis (HR, 1.78).

CONCLUSION

The extent and type of ulceration and involvement of the surrounding epidermis provided more accurate prognostic information than the mere absence or presence and may be useful markers allowing better stratification of ulcerated lesions.

KIT is a frequent target for epigenetic silencing in cutaneous melanoma

The receptor tyrosine kinase KIT and its ligand, stem cell factor (SCF), are essential for the proliferation and survival of normal melanocytes. In melanomas arising on mucosal, acral, and chronically sun-damaged skin, activating KIT mutations have been identified as oncogenic drivers and potent therapeutic targets. Through an initial whole-genome screen for aberrant promoter methylation in melanoma, we identified the KIT promoter as a target for hypermethylation in 43/110 melanoma cell lines, and in 3/12 primary and 11/29 metastatic cutaneous melanomas. Methylation density at the KIT promoter correlated inversely with promoter activity in vitro and in vivo, and the expression of KIT was restored after treatment with the demethylating agent 5-aza-2'-deoxycytidine. Hypermethylation of KIT showed no direct or inverse correlations with well-documented melanoma drivers. Growth of melanoma cells in the presence of SCF led to reduced KIT expression and increased methylation density at the KIT promoter, suggesting that SCF may exert a selection pressure for the loss of KIT. The frequent loss of KIT in cutaneous melanoma by promoter hypermethylation suggests that distinct KIT signaling pathways have opposing roles in the pathogenesis of melanoma subtypes.

Automated quantification of MART1-verified Ki-67 indices: useful diagnostic aid in melanocytic lesions

The MART1-verified Ki-67 proliferation index is a valuable aid to distinguish melanomas from nevi. Because such indices are quantifiable by image analysis, they may provide a novel automated diagnostic aid. This study aimed to validate the diagnostic performance of automated dermal Ki-67 indices and to explore the diagnostic capability of epidermal Ki-67 in lesions both with and without a dermal component. In addition, we investigated the automated indices' ability to predict sentinel lymph node (SLN) status. Paraffin-embedded tissues from 84 primary cutaneous melanomas (35 with SLN biopsy), 22 melanoma in situ, and 270 nevi were included consecutively. Whole slide images were captured from Ki-67/MART1 double stains, and image analysis computed Ki-67 indices for epidermis and dermis. In lesions with a dermal component, the area under the receiver operating characteristic (ROC) curve was 0.79 (95% confidence interval [CI], 0.72-0.86) for dermal indices. By excluding lesions with few melanocytic cells, this area increased to 0.93 (95% CI, 0.88-0.98). A simultaneous analysis of epidermis and dermis yielded an ROC area of 0.94 (95% CI, 0.91-0.96) for lesions with a dermal component and 0.98 (95% CI, 0.97-1.0) for lesions with a considerable dermal component. For all lesions, the ROC area of the simultaneous analysis was 0.89 (95% CI, 0.85-0.92). SLN-positive patients generally had a higher index than SLN-negative patients (P ≤ .003). Conclusively, an automated diagnostic aid seems feasible in melanocytic pathology. The dermal Ki-67 index was inferior to a combined epidermal and dermal index in diagnosis but valuable for predicting the SLN status of our melanoma patients.

E- to N-cadherin switch in melanoma is associated with decreased expression of phosphatase and tensin homolog and cancer progression

BACKGROUND

Cadherin switch in melanoma, with loss of E-cadherin and upregulation of N-cadherin, is believed to underlie melanoma cell detachment from the epidermis and promotion of dermal and vascular melanoma invasion. The tumour suppressor phosphatase and tensin homolog (PTEN) has been suggested as a potential regulator of this cadherin switch.

OBJECTIVES

To study the biological and clinical implications of cadherin switch and PTEN expression in melanoma progression.

METHODS

We constructed tissue microarrays from primary tumour samples from 394 formalin-fixed paraffin-embedded melanomas diagnosed between 2001 and 2006. Median follow-up was 10 years. Tissue microarray sections were stained by immunohistochemistry for E-cadherin, N-cadherin and PTEN, and expression was analysed semiquantitatively.

RESULTS

Breslow thickness correlated strongly with reduced/absent PTEN expression (P < 0·0001), low E-cadherin expression (P < 0·0001), high N-cadherin expression (P < 0·0001) and the combination of low E-cadherin and high N-cadherin expression (cadherin switch profile; P = 0·001). There was a significant association between reduced/absent PTEN and the presence of the cadherin switch profile (P = 0·03). In univariate analyses, low E-cadherin expression significantly predicted an adverse overall relapse-free (P = 0·04), melanoma-specific (P = 0·03) and distant-metastasis-free (P = 0·01) survival; reduced/absent PTEN predicted an adverse overall relapse-free survival (P = 0·006), and the cadherin switch profile predicted adverse melanoma-specific (P = 0·005) and distant-metastasis-free (P = 0·01) survival. In multivariate analysis, the cadherin switch profile was an independent prognostic marker of melanoma-specific (P = 0·04) and distant-metastasis-free survival (P = 0·02).

CONCLUSIONS

Cadherin switch and reduced/absent PTEN expression are associated in melanoma, and both factors may play important roles in the progression of melanoma.

High intratumoral macrophage content is an adverse prognostic feature in anaplastic large cell lymphoma

AIMS

Macrophage infiltration has been associated with prognosis in several cancers, including lymphoma, but has not been assessed systematically in anaplastic large cell lymphoma (ALCL). The aim of the study was to correlate expression of the macrophage-associated antigens CD68 and CD163 with pre-therapeutic parameters and outcome in a cohort of treatment-naive ALCL patients.

METHODS AND RESULTS

Pre-therapeutic tumour specimens from 52 patients with ALCL were included in a tissue microarray. The intratumoral macrophage content was assessed by immunohistochemical staining for CD68 and CD163, and quantified using digital image analysis. Anaplastic lymphoma kinase (ALK)-positive patients were significantly younger and had a favourable outcome compared with ALK-negative ALCL patients (median age: 42 versus 59 years; P = 0.008). However, ALK expression was not a significant predictor when adjusting for age. Although classical risk factors were distributed evenly between the compared groups, high intratumoral content of CD68 and/or CD163 correlated with poor outcome, in both univariate and multivariate analyses. High intratumoral CD163 content showed the strongest adverse association with both overall and progression-free survival in ALK-negative patients (P < 0.001).

CONCLUSIONS

A high content of intratumoral CD68- and/or CD163-positive macrophages correlates with an adverse outcome in ALK-negative ALCL.

Alemtuzumab is effective against severe chronic lymphocytic leukaemia-associated paraneoplastic pemphigus

Alemtuzumab (ALZ) is a monoclonal antibody used in the treatment of a variety of lymphoproliferative diseases, primarily chronic lymphocytic leukaemia (CLL). Paraneoplastic pemphigus (PNP) is a severe mucocutaneous disease, which can occur in association with B-cell malignancies. A correct diagnosis of PNP relies on distinct clinical and histopathological features, and the demonstration, by direct immunofluorescence, of intercellular and basement membrane IgG deposits in the affected tissue. PNP is often refractory to immunosuppressive drugs and frequently has a fatal outcome. We report three cases where sustained remissions of both PNP and CLL were induced by ALZ. In one of these cases, ALZ was able to reinduce a sustained remission of PNP at the reappearance of the disorder years after the primary treatment. In all cases, the PNP diagnosis was confirmed by immunofluorescence. In conclusion, ALZ should be considered as a treatment option in severe CLL-associated PNP. Patients should be carefully selected and receive appropriate infectious prophylaxis before, during and after ALZ treatment, due to the risk of opportunistic infections secondary to combined disease- and drug-induced immunosuppression.