Intralesional photodynamic therapy induces apoptosis in basal cell carcinoma and Bowen's disease through caspase 3 and granzyme B.

BACKGROUND: Photodynamic therapy (PDT) is used to treat cutaneous cancers. It may induce cell death through direct and indirect means, including apoptosis, inflammation and certain immune mechanisms, with the depth of penetration as a potential modifying factor. OBJECTIVES: To examine the pathways of apoptosis in the intralesional PDT of basal cell carcinoma (BCC) and intraepidermal squamous cell carcinoma (Bowen's disease). METHODS: Sixteen patients with superficial or nodular BCC and Bowen's disease were treated with intralesional aminolevulinic acid-PDT. Biopsies were taken at baseline and 24 h post-PDT, and sections were examined by immunohistochemistry for the expression of markers of apoptosis, such as caspase 3, involved in the intrinsic apoptotic pathway, granzyme B, a caspase-independent apoptotic mediator, and the proapoptotic markers BAX and BAK. RESULTS: Apoptotic cells stained with TUNEL showed statistically significant staining at 24 h post PDT (p < 0.01 in both BCC and Bowen's lesions). Caspase 3 (p < 0.01 in BCC and p < 0.05 in Bowen's) and granzyme B (p < 0.01 in BCC and p < 0.01 in Bowen's) were significantly increased at 24 h post-PDT. BAX expression was apparently increased compared to baseline in Bowen's lesions at 24 h post-PDT, whereas Bak was upregulated both in BCC and Bowen's disease at baseline and at 24 h post-PDT. CONCLUSION: Intralesional PDT induces apoptosis in BCC and Bowen's disease via common and alternative apoptotic pathways involving granzyme B. Proapoptotic factors Bak in both BCC and Bowen and Bax in Bowen's disease appear to increase by intralesional PDT at 24 h.

A real-world, non-interventional, prospective study of the effectiveness and safety of apremilast in bio-naïve adults with moderate plaque psoriasis treated in the routine care in Greece - the 'APRAISAL' study.

BACKGROUND: Real-world data in patients with moderate psoriasis treated with apremilast is limited. OBJECTIVES: To evaluate the effectiveness and safety of apremilast in bio-naïve patients with moderate psoriasis in real-world clinical settings. METHODS: This was a 52-week multicenter, observational, prospective study of adult outpatients with moderate psoriasis {[10% < body surface area < 20% or 10 < psoriasis area severity index (PASI) < 20] and 10 < dermatology quality of life index (DLQI) < 20} initiated on apremilast ≤7 days before enrollment. Missing data were imputed using the last observation carried forward method. RESULTS: A total of 287 eligible patients (median age: 54.2 years; median psoriasis duration: 9.8 years) were consecutively enrolled. At baseline, the median DLQI and PASI scores were 12.0 and 11.8, respectively. The 52-week DLQI ≤ 5 and PASI75 response rates were 68.3% and 61.0%. At 52 weeks, 70.8% and 72.7% of the patients shifted from moderate/severe/very severe to clear/minimal scalp and palmoplantar psoriasis involvement, respectively; the pruritus severity state improved in 67.2%. The 52-week Kaplan-Meier estimated drug continuation rate was 85.3%. The adverse drug reaction rate was 19.9%. CONCLUSIONS: Apremilast is a safe and effective treatment for bio-naïve patients with moderate psoriasis and specific psoriasis manifestations.

Effectiveness and safety of apremilast in biologic-naïve patients with moderate psoriasis treated in routine clinical practice in Greece: the APRAISAL study.

BACKGROUND: Apremilast is an oral phosphodiesterase-4 inhibitor indicated for patients with moderate-to-severe chronic plaque psoriasis and active psoriatic arthritis. OBJECTIVES: To examine the effectiveness of apremilast on Dermatology Life Quality Index (DLQI), Psoriasis Area and Severity Index (PASI) and nail, scalp and palmoplantar involvement, when administered prior to biologics. METHODS: This 52-week real-world study included biologic-naive adults with moderate psoriasis (psoriasis-involved body surface area 10% to <20%, or PASI 10 to <20 and DLQI 10 to <20). Apremilast was initiated ≤7 days before enrolment. Data from the first 100 eligible patients who completed 24 weeks (W24) of observation (or were prematurely withdrawn) are presented in this interim analysis using the last-observation-carried-forward imputation method. RESULTS: Eligible patients (mean age: 49.9 years; 71.0% males; median disease duration: 8.0 years) were consecutively enrolled between April and October 2017, by 18 dermatology specialists practising in hospital outpatient settings in Greece. Baseline DLQI (median: 12.0) and PASI (median: 11.7) scores improved (P < 0.001) at all postbaseline timepoints (Weeks 6, 16 and 24; W24 median decreases: 9.0 and 9.4 points respectively). At W24, DLQI ≤5, DLQI 0 or 1, and PASI-75 response rates were 63.0%, 25.0% and 48.0% respectively. The Nail Psoriasis Severity Index score in patients with baseline nail involvement (n = 57) decreased at all postbaseline timepoints (P < 0.001; W24 median decrease: 20.0 points). At W24, 50.0% and 51.7% of patients with baseline scalp (n = 76) and palmoplantar (n = 29) involvement respectively achieved postbaseline Physician's Global Assessment (PGA) score of 0 or 1 if baseline score was ≥3, or 0 if baseline score was 1 or 2. The adverse drug reaction rate was 21.0% (serious: 2.0%). CONCLUSIONS: These interim results indicate that through 24 weeks, apremilast improved quality of life and reduced disease severity in biologic-naive patients with moderate plaque psoriasis, while demonstrating safety consistent with the known safety profile.

Conventional vs. daylight photodynamic therapy for patients with actinic keratosis on face and scalp: 12-month follow-up results of a randomized, intra-individual comparative analysis.

INTRODUCTION: Daylight PDT (DLPDT) is a new PDT procedure. Several trials demonstrate that DLPDT achieves similar response rates with conventional PDT (CPDT) in the treatment of non-hyperkeratotic actinic keratoses (AKs) in a nearly painless way. It seems that DLPDT represents a more convenient and equally effective treatment modality. Data on long-term efficacy of DLPDT are limited. OBJECTIVE: To compare short- and long-term efficacy, safety and tolerability of DLPDT with that of CPDT in face and scalp AKs. METHODS: The study, an intra-individual right-left comparison study, was conducted in three centres in North, Center and South Greece. Eligible patients received either DLPDT or CPDT randomly allocated to alternate sides of face or scalp. Patients were evaluated at baseline, 3 and 12 months after treatment. Assessments included lesion response at 3 and 12 months, PDT-associated pain during PDT session, local skin reactions 3 days after treatment as well as patients' preference 3 months after treatment. RESULTS: A total of 46 patients completed the study. Three months after treatment, the overall lesion complete response rate was 78% for DLPDT and 80.6% for CPDT. At the 12-month follow-up, response rate decreased to 71.8% and 73.7% for DLPDT and CPDT accordingly. Regarding response based on lesion grade, response rates obtained in grade-I lesions were higher with DLPDT, while treatment with CPDT resulted to higher rates of cured grade-II lesions at both follow-up visits. Results were not supported by statistical significance. DLPDT was associated with significantly lower pain and reduced severity of local skin reactions. Patients' preference favoured DLPDT. CONCLUSIONS: Our study demonstrated that DLPDT is similar to CPDT in terms of long-term efficacy and recurrence rates in the treatment of face and scalp AKs. DLPDT demonstrated a better tolerability profile as it was associated with lower pain and less severe adverse events.

Local complications of erysipelas: a study of associated risk factors.

BACKGROUND: Local complications of erysipelas include haemorrhagic, bullous, abscessing and necrotic lesions. The risk factors predisposing patients to local complications are not fully known. AIM: To examine local complications of erysipelas and to identify possible risk factors predisposing to their appearance. METHODS: Medical records from all patients hospitalized with complications of erysipelas (purpura, bullae, abscesses and necrosis), admitted to the University Hospital of Heraklion between 1994 and 2002, were retrospectively studied. Clinical and laboratory data were compared with those from patients with erysipelas without local complications. RESULTS: In total, 145 patients were analysed, of whom 46 had local disease complications. Using bivariate analysis, the factors significantly associated with disease complications were found to be age ≥ 51 years, obesity, longer duration of local symptoms, and fever on admission. During hospitalization, increased C-reactive protein level, isolation of pathogens, longer duration of fever and/or presence of leucocytosis, absence of response to initial antibiotic therapy, and longer length of hospitalization were also associated with complications in the bivariate analysis. However, in the multivariate analysis, obesity (OR 4.489, 95% CI 1.719-11.725, P = 0.002) was the only independent factor associated with complicated erysipelas. CONCLUSIONS: This study found obesity to be an independent risk factor for local complications, of erysipelas. Hence, obese patients with erysipelas are prone to complications, and should be carefully evaluated because of the potential severity of disease and the increased risk of failure of empirical antimicrobial therapy.

The role of endothelial cell apoptosis in the effect of etanercept in psoriasis.

BACKGROUND: Psoriasis is a chronic inflammatory skin disease associated with abnormal vascular expansion in the papillary dermis. Tumour necrosis factor (TNF)-α is a proinflammatory cytokine that can induce antiapoptotic proteins and endothelial cell activation factors in psoriasis. OBJECTIVES: The present study investigated the effect of the anti-TNF-α agent etanercept on the expression of endothelial nuclear factor-κB (NF-κB), angiogenic vascular endothelial growth factor (VEGF), endothelial cell marker CD31, antiangiogenic factor thrombospondin-1 (TSP-1), and antiapoptotic factors Bcl-2 and Bcl-xL in psoriasis. METHODS: Sixteen patients with moderate-to-severe psoriasis were included in the study and treated with etanercept 50 mg twice weekly subcutaneously for 12 weeks. Biopsies of lesional skin (baseline, weeks 3, 6 and 10) were obtained and immunohistochemically stained with antibodies for CD31, VEGF, TSP-1, NF-κB, Bcl-2 and Bcl-xL. Double immunofluorescence staining for VEGF and CD31 was evaluated with confocal laser microscopy. The terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling (TUNEL) assay was applied for apoptosis detection. RESULTS: Etanercept caused a statistically significant time-dependent reduction in the number of dermal blood vessels, the number of CD31+ cells and VEGF in psoriatic lesions, with induction of endothelial cell apoptosis and statistically significant upregulation of TSP-1 in psoriatic vessels. Immunohistochemical analysis showed significant reduction of NF-κB, Bcl-2 and Bcl-xL expression in endothelial cells during treatment. These changes were accompanied by a marked clinical response. CONCLUSIONS: The present findings suggest that treatment with etanercept induces apoptosis, reduces apoptosis-inhibiting factors in psoriatic endothelial cells, and decreases angiogenesis in psoriatic skin.

Chondroitin sulfate and heparan sulfate-containing proteoglycans are both partners and targets of basic fibroblast growth factor-mediated proliferation in human metastatic melanoma cell lines.

Basic fibroblast growth factor (FGF-2) and its respective tyrosine kinase receptors, form an autocrine loop that affects human melanoma growth and metastasis. The aim of the present study was to examine the possible participation of various glycosaminoglycans, i.e. chondroitin sulfate, dermatan sulfate and heparin on basal and FGF-2-induced growth of WM9 and M5 human metastatic melanoma cells. Exogenous glycosaminoglycans mildly inhibited WM9 cell's proliferation, which was abolished by FGF-2. Treatment with the specific inhibitor of the glycosaminoglycan sulfation, sodium chlorate, demonstrated that endogenous glycosaminoglycan/proteoglycan production is required for both basal and stimulated by FGF-2 proliferation of these cells. Heparin capably restored their growth, and unexpectedly exogenous chondroitin sulfate to WM9 and both chondroitin sulfate and dermatan sulfate to M5 cells allowed FGF-2 mitogenic stimulation. Furthermore, in WM9 cells the degradation of membrane-bound chondroitin/dermatan sulfate stimulates basal growth and even enhances FGF-2 stimulation. The specific tyrosine kinase inhibitor, genistein completely blocked the effects of FGF-2 and glycosaminoglycans on melanoma proliferation whereas the use of the neutralizing antibody for FGF-2 showed that the mitogenic effect of chondroitin sulfate involves the interaction of FGF-2 with its receptors. Both the amounts of chondroitin/dermatan/heparan sulfate and their sulfation levels differed between the cell lines and were distinctly modulated by FGF-2. In this study, we show that chondroitin/dermatan sulfate-containing proteoglycans, likely in cooperation with heparan sulfate, participate in metastatic melanoma cell FGF-2-induced mitogenic response, which represents a novel finding and establishes the central role of sulfated glycosaminoglycans on melanoma growth.

Effects of interferons and cytokines on melanoma cells.

This review summarizes recent information on the effects of immunomodulatory cytokines on human melanoma cells. The action of interferon (IFN)-alpha, -beta, and -gamma has been extensively examined in melanoma and melanocyte cultures in vitro, and increasing information on the action of other cytokines is now available. All IFNs revealed a dose-dependent antiproliferative effect on melanoma cells with the highest growth inhibition caused by IFN-beta. Proliferation was also inhibited by interleukin (IL) 1-alpha and -beta, and tumor necrosis factor (TNF)-alpha. For IL-4, both growth-stimulatory and -inhibitory properties have been reported. Cellular differentiation in terms of melanin synthesis, formation of dendritelike structures, and antigenic changes was not affected by IFN-alpha or -beta. IFN-gamma, however, induced a more dedifferentiated and biologically more aggressive phenotype of melanoma cells. Histocompatibility antigen (HLA) class I molecules were found upregulated by all IFNs and by TNF-alpha, associated with a marked increase of melanoma cell lysis by tumor infiltrating lymphocytes in vitro. HLA class II molecules were de novo expressed or enhanced by IFN-gamma and TNF-alpha. The adhesion molecules ICAM-1, LFA-3, and VLA-2 were upregulated by IFN-gamma, TNF-alpha, and IL-1-beta, whereas melanoma-associated antigens were hardly affected by cytokines. It seems that both antiproliferative and immunomodulatory effects may contribute to the antitumoral activity of cytokines in vivo. In vivo application of cytokines as well as combinations with cytotoxic drugs, therefore, may be promising for future treatment strategies.

Effects of interferons on cultured human melanocytes in vitro: interferon-beta but not-alpha or -gamma inhibit proliferation and all interferons significantly modulate the cell phenotype.

The effects of human recombinant interferon-alpha-2a (rIFN-alpha), natural interferon-beta (nIFN-beta) and recombinant interferon-gamma (rIFN-gamma) on the proliferation, morphology and antigen expression of cultured human melanocytes were studied in vitro. The investigations were performed in 12-O-tetradecanoylphorbol-13-acetate (TPA)- and serum-containing melanocyte growth medium (MGM), in TPA- and serum-free complete melanocyte medium (CMM) and its mitogen reduced variant (RMM). In MGM, none of these interferons inhibited the growth of normal melanocytes at concentrations 1-10,000 international units (IU)/ml over a period of 5 d. Only nIFN-beta, dose dependently, inhibited melanocyte proliferation in CMM and RMM in a 6- and 12-d assay (growth inhibition at 10,000 IU/ml; 77-80% of the controls, p less than 0.001). In contrast, rIFN-alpha and rIFN-gamma exerted no (RMM), or minor effects (CMM) on melanocyte proliferation (only in 12-d assays at 10,000 IU/ml: 24% and 21% of the controls respectively, p less than 0.01). In parallel experiments performed on melanoma cells, all three interferons were potent inhibitors of proliferation in a 5-d serum-free assay (growth inhibition at 10,000 IU/ml; rIFN-alpha 59%, nIFN-beta 78%, rIFN-gamma 56%, all p less than 0.001). In addition, nIFN-beta and also rIFN-gamma caused striking morphologic changes of normal melanocytes in vitro. Especially under greater than or equal to 10 IU/ml rIFN-gamma cytoplasmic spreading and flattening of the cultured melanocytes and their nuclei were seen, thus resembling melanoma cells in vitro. Untreated human melanocytes grown in MGM showed high expression of the melanoma-associated antigens HMB-45 (95-100%) and K.1.2 (40-100%), whereas the progression marker A.1.43 was present only on less than 5% of the cells. Cultured melanocytes were 95-100% positive for histocompatibility antigen class I (HLA-I), 30-75% were positive for ICAM-1, whereas they were negative for HLA-DR. After treatment with rIFN-alpha, increased expression of HLA-I antigens was found; nIFN-beta and rIFN-gamma decreased the labeling with HMB-45 (75-100%) and with K.1.2 (25-80%), whereby the expression of A.1.43 was found slightly increased (5-15%). The HLA class I antigens were upregulated by both nIFN-beta and rIFN-gamma, nIFN-beta being the most potent agent. Also, both nIFN-beta and rIFN-gamma increased the expression of ICAM-1 (nIFN-beta, 75-90%; rIFN-gamma, 90-95%) and induced de novo expression of HLA-DR antigen (nIFN-beta, 15-20%; rIFN-gamma, 65-95%).(ABSTRACT TRUNCATED AT 400 WORDS)

12-O-tetradecanoylphorbol-13-acetate not only modulates proliferation rates, but also alters antigen expression and LAK-cell susceptibility of normal human melanocytes in vitro.

For serial cultivation of normal human melanocytes media supplemented with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) are largely employed. By using a culture medium that permits cultivation of melanocytes without TPA, the effects of TPA on melanocyte proliferation, phenotype, and susceptibility to lymphokine-activated killer cells were studied. Addition of 50 ng/ml TPA to the medium induced rapid dendrite formation and increased the cell proliferation rate by 16-63% in mitogen-rich media (four of seven cultures, p < 0.01), and by 237% in mitogen-reduced media (p < 0.001). Furthermore, several phenotypic changes indicating early stages of melanocyte transformation were induced by 50 ng/ml TPA. These included increased expression of melanoma progression-associated antigens such as A.1.43 and A.10.33, upregulation of nerve-growth factor receptor as well as of the melanocyte-activation marker HMB-45 and of histocompatibility class I antigens. In contrast, the expression of the differentiation marker K.1.2 and of intercellular adhesion molecule-1 was decreased in TPA-treated cultures. Most of these changes persisted even after removal of TPA from the culture medium (> or = 2 weeks). Staurosporine, a protein kinase C inhibitor, modulated melanocyte-antigen expression similar to TPA, suggesting that protein kinase C downmodulation rather than activation by TPA is involved. In addition to the antigenic alterations, the susceptibility of TPA-treated melanocytes to lymphokine-activated killer cell cytotoxicity decreased by 40% (p < 0.01), possibly due to their altered surface antigen expression. The presented data reveal that the tumor promoter TPA hitherto used as a supplement of melanocyte culture media induces profound phenotypic and functional changes of the cultured cells, indicating incipient transformation of normal human melanocytes in vitro.

Antitumor activities of interferon alpha, beta, and gamma and their combinations on human melanoma cells in vitro: changes of proliferation, melanin synthesis, and immunophenotype.

The antitumor activities of human interferon (IFN) alpha, beta, and gamma alone or in combination were studied on four human melanoma cell lines (StML-11, StML-12, StML-14, and SKMel-28) in various concentrations (1-50,000 IU/ml IFN alpha, 0.1-1000 IU/ml IFN beta, 1-10,000 IU/ml IFN gamma) in vitro. In all experiments IFN beta exhibited the most potent antiproliferative effect of all IFN tested. After 3 d of incubation a 50% growth inhibition was achieved with 20-40 IU/ml for natural IFN beta and with 600-1200 U/ml for recombinant IFN gamma. Substantially higher doses (7,000 to more than 50,000 IU/ml) of recombinant IFN alpha 2a were required to achieve a 50% growth inhibition. A strong synergistic antiproliferative activity resulted from the combination of IFN alpha with IFN gamma and IFN beta with IFN gamma. None of the IFN tested induced terminal differentiation of melanoma cells in vitro. The formation of dendrites was inhibited, and the portion of differentiated cells in vitro was reduced after treatment with IFN in comparison to the untreated controls (untreated controls: 100%; portion of differentiated cells after treatment with IFN alpha: 58%-74%, IFN beta: 48%-96%, IFN gamma: 10%-33%). The melanin synthesis was slightly elevated after treatment with IFN alpha (untreated controls: 100%; after treatment with IFN alpha: 103%-157%, ns.) and decreased significantly after treatment with IFN beta (49%-71%, p less than 0.05) as well as with IFN gamma (80%-88%, ns.). Cell surface markers were modulated varyingly by the IFN: HLA-I antigens were enhanced by all IFN, with IFN beta emerging as the most potent inducer. Only IFN gamma, however, induced a de novo expression of HLA-DR and -DQ antigens and increased the expression of the ICAM-1 molecule and of the melanoma progression marker A.1.43. Possibly, these findings indicate a biologically more aggressive phenotype of melanoma cells.

Cytostatic and cytotoxic effects of recombinant tumor necrosis factor-alpha on sensitive human melanoma cells in vitro may result in selection of cells with enhanced markers of malignancy.

Monolayer cultures of the human melanoma cell lines StML-12, StML-11, StML-14 (third, respectively, twenty-fifth subculture), and SKMel-28 derived from specimens representing different stages of tumor progression were treated with 10-10,000 U/ml rTNF-alpha applied for 72 h. The effects of rTNF-alpha on cell proliferation, DNA synthesis, cell viability, cloning efficiency, cell division, cell morphology, and the immunophenotype were studied in triplicate experiments. The cell line StML-14(3) revealed a significantly dose-dependent reduction of growth due to both cytostatic and cytotoxic activities of rTNF-alpha as well as a decrease of CE. Increased numbers of cells in prophase were observed 24 h after addition of r-TNF-alpha. In addition, dislocation of chromosomes in the metaphase, formation of micronuclei, and dose-dependent increases of cells exhibiting micronuclei and the DNA amount per cell were detected at the end of treatment. On the other hand, only a slight sensitivity to the anti-proliferative effect of rTNF-alpha was observed with StML-14(25) and SKMel-28, whereas StML-12 and StML-11 were significantly resistant. The last four cell lines were serially subcultivated and presented common phenotypic patterns with more malignant characteristics than the cell line StML-14(3) before treatment. Overall, rTNF-alpha enhanced the malignant immunophenotype of the cell lines tested. It increased the expression of the "late" melanoma progression markers A.10.33 and A.1.43, and Ki67, and it decreased the expression of the "early" progression marker K.1.2. The expression of HLA-I, HLA-DR, and ICAM-1 was also enhanced after rTNF-alpha treatment, whereas in contrast to other cytokines, rTNF-alpha did not induce the de novo expression of HLA-DR in HLA-DR-negative melanoma cell lines. These findings indicate that rTNF-alpha induces cytostasis and decreases cell viability of certain rTNF-alpha-sensitive melanoma cells. These effects may result in selection of rTNF-alpha-non-sensitive human melanoma cell populations with higher proliferation rates and a more aggressive immunophenotype in vitro.

RT-PCR for tyrosinase-mRNA-positive cells in peripheral blood: evaluation strategy and correlation with known prognostic markers in 123 melanoma patients.

Reverse transcriptase polymerase chain reaction for the detection of tyrosinase-mRNA-positive cells in peripheral blood of melanoma patients, as a possible marker of hematogenous dissemination, has demonstrated varying detection rates. This study examined the sensitivity and reproducibility of the technique using a protocol of multiple polymerase chain reaction to determine circulating melanocytic cells. For each of the 123 melanoma patients included in this study, four nested polymerase chain reactions were performed from two blood specimens requiring both polymerase chain reactions from at least one blood sample to be positive to consider a patient as positive. Thus, a definitive result was obtained in 98% of the cases, whereas only 1.6% lacked conclusive findings. Thus, we found a correlation between the tyrosinase detection rate and the clinical stage. Circulating tyrosinase-mRNA-positive cells were detected in 13% of patients with primary tumor, 17% with regional skin/lymph node metastasis, and 44% with distant metastasis. Positivity also correlated with known melanoma progression markers such as gender, tumor thickness, and histologic type. Positive results were obtained more frequently in (i) men compared with women, (ii) patients with thick primary melanomas (> 4 mm: 38%) compared with those with thinner tumors (1.1-4 mm, 22%; < or = 1 mm, 5%), and (iii) patients with nonclassifiable (38%), nodular (34%), and occult primary melanomas (30%) compared with those with acrolentiginous (17%), superficial spreading (9%), or lentigo maligna melanoma (0%). These findings suggest that detection of tyrosinase-mRNA-positive cells in peripheral blood is not an adequate marker for identifying melanoma patients with distant metastasis. Reverse transcriptase polymerase chain positivity in early melanoma stages, however, as corresponding to other prognostic parameters, may indicate increased risk for the development of hematogenous metastasis and may be of value as a progression marker.

Capsaicin inhibits plasma membrane NADH oxidase and growth of human and mouse melanoma lines.

Hormone- and growth factor-stimulated NADH oxidase of the mammalian plasma membrane is thought to be involved in the control of normal cell proliferation. The aim of this study was to determine the effect of the naturally occurring quinone analogue capsaicin (8-methyl-N-vanillyl-6-noneamide) on the NADH oxidase activity of plasma membranes and cell growth of human primary melanocytes, the A-375 and SK-MEL-28 human melanoma cell cultures. NADH oxidase activity was inhibited preferentially in the A-375 melanoma cells but not in the primary melanocytes, by capsaicin. Inhibition of growth and the NADH oxidase by capsaicin could be induced in resistant SK-MEL-28 melanoma cells by co-administration of capsaicin with t-butyl hydroperoxide, a mild oxidising agent. Death of the inhibited cells was accompanied by nuclear changes suggestive of apoptosis. With B16 mouse melanoma, capsaicin inhibited both the NADH oxidase activity and growth in culture. Growth of B16 melanoma, transplanted in C57BL/6 mice, was significantly inhibited by capsaicin injected directly into the tumour site when co-administered with t-butyl hydroperoxide. The findings correlate the inhibition of cell surface NADH oxidase activity with inhibition of growth and capsaicin-induced apoptosis, and also suggest that the extent of inhibition may relate to the oxidation state of the plasma membrane.

Effects of thymic peptides, in vitro, on the impaired immunocytotoxicity of peripheral blood mononuclear cells from tumor patients.

The effects of a thymic peptide preparation (TP) on the immunocytotoxicity and cytokine secretion of peripheral blood lymphocytes and monocytes from patients with colorectal tumors, breast tumors and melanoma were studied in vitro. On average, breast tumor and melanoma patients showed significantly lower natural killer (NK) cell activities than colorectal tumor patients and normal controls. In contrast, the generation of lymphokine (IL-2) activated killer (LAK) cells was found to be comparable within the different tumor diseases (24% cytotoxicity), but lower than in the group of normal controls. TP, being without any effects on NK cell activity in all groups, increased the deficient LAK cell activity of breast tumor and melanoma patients, as well as of normal controls? without significant effects on PBL from colorectal tumor patients. This increase was found to be associated with an increase of the IL-2 induced IFN-gamma and, on a lower level, TNF-alpha secretion, especially from breast tumor and melanoma patients. In addition, monocytes from these patients showed a deranged tumoristatic activity, compared to colorectal tumor patients and normal controls. The stimulation of monocytes by IFN-gamma greatly elevated the mean of the antitumor activity in all groups studied. TP being slightly effective on monocytes from melanoma patients, did not further enhance monocyte-mediated cytotoxicity when applied alone or in combination with IFN-gamma. Reduced basal monocytic chemokine levels were only found in the groups of melanoma (IL-8) and colorectal tumor patients (MCP-1), whereas RANTES secretion was increased, compared to normal controls. TP was active only in reducing the IL-8 secretion of monocytes from colon tumor patients. The results indicate that selected functions of peripheral blood mononuclear cells can be partially improved by the thymic peptide preparation.

Production of cytokines by human melanoma cells and melanocytes.

Experimental animal models have shown that various cytokines, depending of their specific properties, may support growth and metastasis of tumor cells or even lead to tumor rejection. The analysis of expression of cytokine genes by melanoma cell lines indicated that melanoma cells constitutively produce both autostimulatory and inhibitory cytokines. Using reverse transcriptase polymerase chain reaction analysis, simultaneous expression of several cytokines, including interleukin-1 beta (IL-1 beta), IL-6, IL-8, tumor necrosis factor-alpha, and granulocyte-macrophage colony-stimulating factor, by melanoma cells was found. The same cytokine transcripts were detected in melanocytes, suggesting that cells of the melanocytic lineage express a specific pattern of cytokines in vitro. All these cytokines are known to be able to stimulate effector cells of the host. Additionally, production of mRNA for IL-10, a cytokine with potential immunosuppressive properties, was detected in melanoma cells and melanocytes. These and other cytokines are likely to be involved in the immune response to cancer and at this time it is unknown what the net effects of multiple cytokines are on the outcome of the host response to tumor.

Growth control of melanoma cells and melanocytes by cytokines.

Aberrant proliferation of tumor cells characterizes cancer growth. Investigations of cellular growth control mechanisms have contributed to our understanding of carcinogenesis and to the identification of compounds with specific antitumor activity. Many cytokines have been found to act on melanoma tumors, either produced by the tumor cells themselves or by infiltrating host cells. Purified cytokines allowed direct comparison of the growth response between normal human melanocytes and malignant melanoma cells. The present paper summarizes results of a series of our own experiments not yet published and data from a review of the recent literature. Proliferation of normal human melanocytes is enhanced by several cytokines, including basic fibroblast growth factor (bFGF), melanoma growth stimulatory activity (MGSA), hepatocyte growth factor (HGF), and mast cell growth factor (MGF). Melanoma cells are additionally stimulated by epidermal growth factor (EGF)/transforming growth factor alpha (TGF-alpha) and nerve growth factor (NGF). Tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta 1 (TGF-beta 1), and interleukin (IL)-6 are all potent inhibitors of melanocyte growth, but they are less effective on melanoma cells or even stimulate their growth. Interferon (IFN)-alpha and IFN-gamma inhibited proliferation of melanoma cells but not of melanocytes, whereas IFN-beta showed antiproliferative effects in both cell types. These findings suggest an alteration in growth control mechanisms during melanocyte transformation and possibly play a role in melanoma pathogenesis.

Low molecular thymic peptides improve the deficient immunocytotoxicity of mononuclear cells from tumor patients in vitro.

We studied, in vitro, the stimulating effects of a commercial preparation of low molecular thymic peptides (TP) on the immunocytotoxicity of peripheral blood lymphocytes and monocytes from patients with breast tumors, melanoma and colorectal tumors. On average, tumor patients showed a lower natural killer (NK), lymphokine (IL-2) activated killer (LAK) cell and basic tumoristatic activity of monocytes, compared with healthy donors. There was no correlation between the NK-cell number and the NK-cell activity of the tumor patients. The TP showed no effects on the NK-cell activity in any group, yet elevated the deficient LAK-cell activity of tumor patients and that of healthy donors. On monocytes, TP enhanced the deranged tumoristatic activity only in tumor patients, while being slightly inhibitory on control monocytes. Dividing the donors on the basis of the TP effects on cytotoxicity of the mononuclear cells into TP-nonresponders and TP-responders, a higher number of TP-responders was found among tumor patients, compared with healthy donors. Moreover, a higher number of TP-nonresponders were observed with lymphocytes from colorectal tumor patients at advanced tumor stage. Therefore, on the basis of the applied immunocytotoxic assays, these results may provide a basis for selecting tumor patients, who may respond to TP in immunotherapy protocols.