Lorenzo Borgognoni

Osteonectin expression correlates with clinical outcome in thin cutaneous malignant melanomas

Osteonectin, also termed BM40 or SPARC (secreted protein, acidic and rich in cysteine) is a multifunctional glycoprotein involved in tissue mineralization, cell-extracellular matrix interactions as well as angiogenesis. It has been suggested that osteonectin may play a key role in the process of tumoral invasion and metastasis in certain malignancies. In this study, we reviewed the clinical records and the histopathologic slides of 188 thin cutaneous malignant melanomas (< or = 0.75 mm). Among them, 12 cases underwent progression and were selected for the study. Osteonectin expression was investigated by immunohistochemistry in these 12 patients and 24 matched controls who did not undergo progression. Osteonectin staining was correlated with clinical outcome and other clinicopathologic parameters. Progression-free and disease-specific survival rates were calculated with the Kaplan-Meier method and their differences were evaluated by the log rank test. Overall, immunoreactivity for osteonectin was found in 23 (63.8%) cases. Eighteen cases (50%) displayed staining in 1% to 50% of neoplastic cells whereas five cases (13.8%) showed a diffuse positivity in more than 50% of the tumor cells. Osteonectin expression was significantly correlated with risk of progression (P = .01), incidence of distant metastases (P = .005) and survival (P = .03). There was a higher incidence of osteonectin-positive tumors in cases that did experience regional lymph node metastases versus those cases that did not, but that difference did not reach statistical significance (P = .06). No significant correlation was found between osteonectin expression and other clinicopathologic features, including age, sex, site, histotype, Clarks level, presence of regression, presence of inflammatory response, and tumor growth phase. Our data showed that osteonectin expression is a predictor of clinical outcome in thin cutaneous melanomas.

HEDGEHOG‐GLI Signaling Drives Self‐Renewal and Tumorigenicity of Human Melanoma‐Initiating Cells

The question of whether cancer stem/tumor‐initiating cells (CSC/TIC) exist in human melanomas has arisen in the last few years. Here, we have used nonadherent spheres and the aldehyde dehydrogenase (ALDH) enzymatic activity to enrich for CSC/TIC in a collection of human melanomas obtained from a broad spectrum of sites and stages. We find that melanomaspheres display extensive in vitro self‐renewal ability and sustain tumor growth in vivo, generating human melanoma xenografts that recapitulate the phenotypic composition of the parental tumor. Melanomaspheres express high levels of Hedgehog (HH) pathway components and of embryonic pluripotent stem cell factors SOX2, NANOG, OCT4, and KLF4. We show that human melanomas contain a subset of cells expressing high ALDH activity (ALDHhigh), which is endowed with higher self‐renewal and tumorigenic abilities than the ALDHlow population. A good correlation between the number of ALDHhigh cells and sphere formation efficiency was observed. Notably, both pharmacological inhibition of HH signaling by the SMOOTHENED (SMO) antagonist cyclopamine and GLI antagonist GANT61 and stable expression of shRNA targeting either SMO or GLI1 result in a significant decrease in melanoma stem cell self‐renewal in vitro and a reduction in the number of ALDHhigh melanoma stem cells. Finally, we show that interference with the HH‐GLI pathway through lentiviral‐mediated silencing of SMO and GLI1 drastically diminishes tumor initiation of ALDHhigh melanoma stem cells. In conclusion, our data indicate an essential role of the HH‐GLI1 signaling in controlling self‐renewal and tumor initiation of melanoma CSC/TIC. Targeting HH‐GLI1 is thus predicted to reduce the melanoma stem cell compartment. Stem Cells2012;30:1808–1818

Inducible nitric oxide synthase expression in benign and malignant cutaneous melanocytic lesions.

Nitric oxide (NO) is synthesized by nitric oxide synthases (NOS) and plays an important role in tumour growth. In this study, inducible NOS (iNOS) expression was evaluated by immunohistochemistry in 34 melanocytic naevi (13 common melanocytic naevi, six Spitz naevi, and 15 so‐called ‘dysplastic naevi’), ten cutaneous melanomas in situ, 50 stage I invasive melanomas, and eight subcutaneous metastases of melanoma. In addition, four samples of melanocytic naevi and four samples of invasive melanomas were collected in order to perform western blot and northern blot analysis. By immunohistochemistry, melanocytic naevi never expressed iNOS. Among cases of melanoma in situ, two were negative, seven displayed staining in less than 20% of melanoma cells, and positivity was observed in 21–50% of melanoma cells in only one case. iNOS expression was detected in 46 out of 50 invasive melanomas (92%). Among these cases, 18 showed positivity in less than 20% of melanoma cells, 18 showed positivity in 21–50% of melanoma cells, and ten showed iNOS expression in more than 50% of cells. Statistical analysis revealed a significant difference in iNOS expression between melanocytic naevi and cutaneous melanomas (p<0.001). In addition, iNOS expression was significantly higher in invasive melanomas than in melanomas in situ (p=0.01). Among primary cutaneous melanomas, no significant correlation was found between iNOS expression and histopathological parameters (histotype, level, thickness and presence of regression/inflammatory infiltrate) and disease‐specific survival. In subcutaneous melanoma metastases, iNOS expression was diffuse in more than 50% of cells. Statistical analysis revealed that subcutaneous melanoma metastases showed greater iNOS immunoreactivity than invasive melanomas (p=0.02). Molecular analyses confirmed that iNOS mRNA and protein were highly expressed in melanoma samples. In conclusion, iNOS was constantly absent in melanocytic naevi, whereas it was frequently expressed in melanomas, with up‐regulation of the enzyme paralleling tumour progression. These data suggest that iNOS may play a role in the malignant transformation of melanocytes and in tumour growth. In addition, iNOS may be useful as an immunohistochemical marker for malignant melanocytic lesions. Copyright

A Key Role for Poly(ADP-Ribose) Polymerase-1 Activity during Human Dendritic Cell Maturation

Poly(ADP-ribose) (PAR) polymerase (PARP)-1 is a nuclear enzyme regulating protein that functions by targeting PAR chains. Besides its classic role in DNA repair, PARP-1 is emerging as a key transcriptional regulator in different cell types including the immune ones. In this study, we investigated the role of PARP-1 in human dendritic cell (DC) function. We report that both PARP-1 mRNA and protein levels significantly increased during in vitro DC differentiation from monocytes. Of note, inhibitors of PARP-1 such as phenanthridinone and thieno[2,3-c]isoquinolin-5-one reduced expression of CD86 and CD83 in a concentration-dependent manner, having no effects on expression of CD80 and HLA-DR in mature DCs. In the same cultures, PARP-1 inhibitors also reduced production of IL-12 and IL-10. Addition of exogenous IL-12 to the culture medium partially restored CD86 expression in DCs exposed to PARP-1 inhibitors. In line with the role of PAR formation in NF-κB-dependent transactivation, we also report that phenanthridinone and thieno[2,3-c]isoquinolin-5-one impaired NF-κB and AP-1 subunit DNA binding activity in cellular extract of activated DCs. Finally, we show that PARP-1 inhibitors reduced the T cell allostimulatory activity of mature DCs, and that this reduction was prevented when DCs matured in the presence of PARP-1 inhibitors plus IL-12. Of note, nonproliferating T cells exposed to PARP-1 inhibitor-challenged DCs could undergo efficient proliferation when exposed to a subsequent activation stimulus such as anti-CD3 plus anti-CD-28. Together, data provide evidence for a key role of PARP-1 and poly ADP-ribosylation in DC immunocompetence and underscore the relevance of PARP-1 inhibitors to treatment of immune disorders.

Thick cutaneous malignant melanoma: a reappraisal of prognostic factors.

&NA; The prognosis of patients with thick (> 3 mm) cutaneous malignant melanomas is generally poor; however, some cases survive far longer than expected. Thus tumour thickness cannot serve as the only predictor of disease course in the individual patient. The aims of the current study were to evaluate the clinical outcome of patients with thick (> 3 mm) cutaneous melanoma and test the prognostic value of a series of clinicopathological parameters on disease‐free and cause‐specific survival. We retrospectively evaluated 140 patients with stage I cutaneous melanoma > 3 mm in thickness. Disease‐free and cause‐specific survival rates (Kaplan‐Meier method) were compared using the log rank test. A multivariate analysis (Cox proportional hazards model) was used to determine the independent effect of each variable on prognosis. The overall 5‐year and 10‐year disease‐free survival rates were 35.5% and 29.3%, respectively, whereas the overall 5‐year and 10‐year cause‐specific survival rates were 55.3% and 47.7%, respectively. In the univariate analysis, the following factors were found to be significantly associated with the disease‐free and cause‐specific survival: tumour thickness, mitotic rate/mm2, type of invasive front, ulceration, thickness of the nodular component and predominant cell type. In addition, the presence of vascular invasion was significantly correlated with the risk of metastases but not with survival. In the multivariate analysis (Cox proportional hazards model), only tumour thickness (both as a continuous variable and > 7.5 mm), infiltrating invasive front, presence of ulceration and mitotic rate/mm2 (both as a continuous variable and > 10 mitoses/mm2) were significant independent predictors of poorer clinical outcome.

Prediction of Survival in Patients With Thin Melanoma: Results From a Multi-Institution Study

PURPOSE Cutaneous melanoma incidence is increasing. Most new cases are thin (≤ 1 mm) with favorable prognoses, but survival is nonetheless variable. Our aim was to investigate new prognostic factors and construct a nomogram for predicting survival in individual patients. PATIENTS AND METHODS Data from 2,243 patients with thin melanoma were retrieved from prospectively maintained databases at six centers. Kaplan-Meier survival and crude cumulative incidences of recurrence were estimated, and competing risks were taken into account. Multivariable Cox regression was used to investigate survival predictors. RESULTS Median follow-up was 124 months (interquartile range, 106 to 157 months); 12-year overall survival was 85.3% (95% CI, 83.4% to 87.2%). Median times to local, regional, and distant recurrence were 79, 78, and 107 months, respectively. Relapse was significantly related to age, Breslow thickness, mitotic rate (MR), ulceration, lymphovascular invasion (LVI), and regression; incidence was lower and subgroup differences were less marked for distant metastasis than for regional relapse. The worst prognosis categories were age older than 60 years, Breslow thickness more than 0.75 mm, MR ≥ 1, presence of ulceration, presence of LVI, and regression ≥ 50%. Breslow thickness more than 0.75 mm, MR ≥ 1, presence of ulceration, and LVI (all P = .001) were significantly associated with sentinel node positivity. Age, MR, ulceration, LVI, regression, and sentinel node status were independent predictors of survival and were used to construct a nomogram to predict 12-year overall survival. The nomogram was well calibrated and had good discriminative ability (adjusted Harrell C statistic, 0.88). CONCLUSION Our findings suggest including LVI and regression as new prognostic factors in the melanoma staging system. The nomogram appears useful for risk stratification in clinical management and for recruiting patients to clinical trials.

Nonsentinel Lymph Node Status in Patients With Cutaneous Melanoma: Results From a Multi-Institution Prognostic Study

PURPOSE We investigated whether the nonsentinel lymph node (NSLN) status in patients with melanoma improves the prognostic accuracy of common staging features; then we formulated a proposal for including the NSLN status in the current melanoma staging system. PATIENTS AND METHODS We retrospectively collected the clinicopathologic data of 1,538 patients with positive SLN status who underwent completion lymph node dissection (CLND) at nine Italian centers. Multivariable Cox regression survival analysis was used to identify independent prognostic factors. Literature meta-analysis was used to summarize the available evidence on the prognostic value of the NSLN status in patients with positive SLN. RESULTS NSLN metastasis was observed in 353 patients (23%). After a median follow-up of 45 months, NSLN status was an independent prognostic factor for melanoma-specific survival (hazard ratio [HR] = 1.34; 95% CI, 1.18 to 1.52; P < .001). NSLN status efficiently stratified the prognosis of patients with two to three positive lymph nodes (n = 387; HR = 1.39; 95% CI, 1.07 to 1.81; P = .013), independently of other staging features. Searching the literature, this patient subgroup was investigated in other two studies. Pooling the results (n = 620 patients; 284 NSLN negative and 336 NSLN positive), we found that NSLN status is a highly significant prognostic factor (summary HR = 1.59; 95% CI, 1.27 to 1.98; P < .001) in patients with two to three positive lymph nodes. CONCLUSION These findings support the independent prognostic value of the NSLN status in patients with two to three positive lymph nodes, suggesting that this information should be considered for the routine staging in patients with melanoma.

WIP1 phosphatase modulates the Hedgehog signaling by enhancing GLI1 function

The Hedgehog-GLI (HH-GLI) signaling plays a critical role in controlling growth and tissue patterning during embryogenesis and is implicated in a variety of human malignancies, including those of the skin. Phosphorylation events have been shown to regulate the activity of the GLI transcription factors, the final effectors of the HH-GLI signaling pathway. Here, we show that WIP1 (or PPM1D), an oncogenic phosphatase amplified/overexpressed in several types of human cancer, is a positive modulator of the HH signaling. Mechanistically, WIP1 enhances the function of GLI1 by increasing its transcriptional activity, nuclear localization and protein stability, but not of GLI2 nor GLI3. We also find that WIP1 and GLI1 are in a complex. Modulation of the transcriptional activity of GLI1 by WIP1 depends on the latter’s phosphatase activity and, remarkably, does not require p53, a known WIP1 target. Functionally, we find that WIP1 is required for melanoma and breast cancer cell proliferation and self-renewal in vitro and melanoma xenograft growth induced by activation of the HH signaling. Pharmacological blockade of the HH pathway with the SMOOTHENED antagonist cyclopamine acts synergistically with inhibition of WIP1 in reducing growth of melanoma and breast cancer cells in vitro. Overall, our data uncover a role for WIP1 in modulating the activity of GLI1 and in sustaining cancer cell growth and cancer stem cell self-renewal induced by activation of the HH pathway. These findings open a novel therapeutic approach for human melanomas and, possibly, other cancer types expressing WIP1 and with activated HH pathway.

Induction of CD83+CD14+ Nondendritic Antigen-Presenting Cells by Exposure of Monocytes to IFN-α

IFN-α is a well-known agent for treatment of viral and malignant diseases. It has several modes of actions, including direct influence on the immune system. We investigated IFN-α effects on PBMC in terms of dendritic cell (DC) differentiation, as PBMC are exposed to high IFN-α levels during treatment of infections and cancers. We show that in vitro IFN-α exposure induced rapid and strong up-regulation of the DC-maturation markers CD80, CD86, and CD83 in bulk PBMC. Consistently, IFN-α induced up-regulation of these molecules on purified monocytes within 24 h. Up-regulation of CD80 and CD83 expression was IFN-α concentration-dependent. In contrast to GM-CSF + IL-4-generated DCs, most of the IFN-α-challenged CD83+ cells coexpressed the monocyte marker CD14. Despite a typical mature DC immunophenotype, IFN-α-treated monocytes conserved phagocytic activity and never acquired a dendritic morphology. In mixed lymphocyte reactions IFN-α-treated monocytes were less potent than GM-CSF + IL-4-generated DCs but significantly more potent than untreated monocytes to induce T cell proliferation in bulk PBMC. However, only GM-CSF + IL-4-generated DCs were able to induce a significant proliferation of naive CD4+ T cells. Notably, autologous memory CD4+ T cells proliferated when exposed to tetanus toxoid-pulsed IFN-α-treated monocytes. At variance with untreated or GM-CSF + IL-4-exposed monocytes, those challenged with IFN-α showed long-lasting STAT-1 phosphorylation. Remarkably, CD83+CD14+ cells were present in varicella skin lesions in close contact with IFN-α-producing cells. The present findings suggest that IFN-α alone promptly generates nondendritic APCs able to stimulate memory immune responses. This may represent an additional mode of action of IFN-α in vivo.

Enhancing anti-melanoma immunity by electrochemotherapy and in vivo dendritic-cell activation

Combining electrochemotherapy with dendritic cell-based immunotherapy is a promising strategy against human metastatic melanoma that deserves to be clinically assessed. While electrochemotherapy induces a rapid regression of metastases, immunotherapy generates systemic anticancer immunity, contributes to eradicate the tumor and maintains an immunological memory to control relapse.