Cytotoxic Effect of Vanicosides A and B from Reynoutria sachalinensis Against Melanotic and Amelanotic Melanoma Cell Lines and in silico Evaluation for Inhibition of BRAFV600E and MEK1.

Vanicosides A and B are the esters of hydroxycinnamic acids with sucrose, occurring in a few plant species from the Polygonaceae family. So far, vanicosides A and B have not been evaluated for anticancer activity against human malignant melanoma. In this study, we tested these two natural products, isolated from Reynoutria sachalinensis rhizomes, against two human melanoma cell lines (amelanotic C32 cell line and melanotic A375 cell line, both bearing endogenous BRAFV600E mutation) and two normal human cell lines-keratinocytes (HaCaT) and the primary fibroblast line. Additionally, a molecular docking of vanicoside A and vanicoside B with selected targets involved in melanoma progression was performed. Cell viability was studied using an MTT assay. A RealTime-Glo™ Annexin V Apoptosis and Necrosis assay was used for monitoring programmed cell death (PCD). Vanicoside A demonstrated strong cytotoxicity against the amelanotic C32 cell line (viability of the C32 cell line was decreased to 55% after 72 h incubation with 5.0 µM of vanicoside A), significantly stronger than vanicoside B. This stronger cytotoxic activity can be attributed to an additional acetyl group in vanicoside A. No significant differences in the cytotoxicity of vanicosides were observed against the less sensitive A375 cell line. Moreover, vanicosides caused the death of melanoma cells at concentrations from 2.5 to 50 µM, without harming the primary fibroblast line. The keratinocyte cell line (HaCaT) was more sensitive to vanicosides than fibroblasts, showing a clear decrease in viability after incubation with 25 µM of vanicoside A as well as a significant phosphatidylserine (PS) exposure, but without a measurable cell death-associated fluorescence. Vanicosides induced an apoptotic death pathway in melanoma cell lines, but because of the initial loss of cell membrane integrity, an additional cell death mechanism might be involved like permeability transition pore (PTP)-mediated necrosis that needs to be explored in the future. Molecular docking indicated that both compounds bind to the active site of the BRAFV600E kinase and MEK-1 kinase; further experiments on their specific inhibitory activity of these targets should be considered.

Effects of electrophotodynamic therapy in vitro on human melanoma cells--melanotic (MeWo) and amelanotic (C32).

Photodynamic therapy has been considered ineffective for melanomas because of the competition between the absorbance of melanin from the melanoma and the absorbance of photosensitizers at the photosensitizer excitation light wavelength. Melanomas show considerable heterogeneity and resistance to phototherapy. The effectiveness of photodynamic therapy could be intensified by electroporation for enhanced transport of a photosensitizer by transient pores in the membrane. In this study, photodynamic therapy combined with electroporation was tested in vitro on the human melanoma cell lines melanotic melanoma (MeWo) and amelanotic melanoma (C32). Control experiments were conducted on human keratinocytes (HaCaT). Photofrin was used as a photosensitizer. Photosensitizer distribution, cloning efficacy test, comet assay, and assessment of apoptotic proteins were performed. Melanin levels were determined before and after photodynamic therapy. The experiments indicated that electroporation effectively supports the photodynamic method. It was found that photodynamic therapy with electroporation efficiently induces apoptosis in melanotic and amelanotic melanoma cells.

Photothermal sensitisation and therapeutic properties of a novel far-red absorbing cyanine.

A water-soluble disulfonate cyanine was prepared by chemical synthesis and shown to possess photophysical properties which are particularly favourable for the promotion of photothermally sensitised processes, including a very low (<0.1) quantum yield of fluorescence emission and ultra-short (110 to 400 ps) excited state lifetimes, as well as the presence of intense absorption bands at wavelengths longer than 800 nm. This allows the possibility of high-energy irradiation by means of a Ti:sapphire laser operated in a pulse regime. The cyanine was accumulated in comparable amounts by B78H1 amelanotic melanoma cells and HT1080 transformed fibroblasts, however only the B78H1 cells could be extensively damaged by photothermal sensitisation with the cyanine, which was endocellularly distributed as suggested by observations at the optical microscope; the efficiency of the photoprocess could be enhanced by formation of aggregated intracellular cyanine clusters. On the other hand, only a modest photoinactivation of HT1080 cells was induced by photothermal sensitisation, possibly owing to the localization of the cyanine at the periphery of such cells. The cyanine also exhibited a good selectivity of amelanotic melanoma targeting in C57BL/6 mice, bearing the tumour subcutaneously transplanted in the dorsal area: the ratio of cyanine concentration in the melanoma and the surrounding cutaneous districts was as large as 3.8 at 1 h post-injection. The cyanine underwent a fast clearance from the organism, since only traces of the photosensitiser were observed in all the studied tissues at 3 h after i.v. administration. Thus, irradiations were performed at post-injection times shorter than 1 h. Maximum photothermal sensitisation efficiency was obtained at 10 min after injection with a 50% cure rate. Thus, photothermal therapy (PTT) appears to be a very promising and efficient modality of tumour treatment.

Antiproliferative activity on human cancer cell lines after treatment with polyphenolic compounds isolated from Iris pseudopumila flowers and rhizomes.

The present study describes the antiproliferative properties of Iris pseudopumila flowers and rhizomes extracts and fourteen constituents isolated from them. The in vitro cytotoxic activity assay against two human cancer cell lines, large lung carcinoma (CORL-23) and amelanotic melanoma (C32), showed that the most antiproliferative extract was the MeOH extract from flowers with a percentage of inhibition of 50.9 at 100 microg/ml against amelanotic melanoma cells. The most antiproliferative compounds against amelanotic melanoma cells were kaempferol-3-O-beta-D-glucopyranoside and irisolidone with a percentage of inhibition of 100 and 96.6, respectively, and against large lung carcinoma cells with a percentage of inhibition of 82.1 and 84.6, respectively. Significant activity on the amelanotic melanoma cell line was also showed by irigenin-7-O-beta-D-glucopyranoside, with a percentage of inhibition of 89.3. The compounds isovitexin and isoorientin-6-O''-beta-D-glucopyranoside showed a selective activity against amelanotic melanoma cells with a percentage of inhibition of 83.2 and 79.8, respectively.

Antiproliferative effects of essential oils and their major constituents in human renal adenocarcinoma and amelanotic melanoma cells.

OBJECTIVES: The purpose of this study was to evaluate cytotoxic activity of Platycladus orientalis, Prangos asperula and Cupressus sempervirens ssp. pyramidalis essential oils and to identify active components involved in inhibition of population growth of human cancer cell lines. MATERIALS AND METHODS: Essential oils were obtained by hydrodistillation and were analysed by gas chromatography and gas chromatography coupled to mass spectrometry. Antiproliferative activity was tested on amelanotic melanoma C32 cells and on renal cell adenocarcinoma cells, using the sulphorhodamine B assay. RESULTS: Cupressus sempervirens ssp. pyramidalis leaf oil exerted the highest cytotoxic activity with an IC(50)value of 104.90 microg/mL against C32, followed by activity of P. orientalis and P. asperula on the renal adenocarcinoma cell line (IC(50) of 121.93 and 139.17 microg/mL, respectively). P. orientalis essential oil was also active against amelanotic melanoma with an IC(50) of 330.04 microg/mL. Three identified terpenes, linalool, beta-caryophyllene and alpha-cedrol, were found to be active on both cell lines tested. CONCLUSIONS: Our findings provide novel insights into the field of cytotoxic properties of essential oils. This study provided evidence on how cytotoxic activity of the oils is not always related to their major constituents, except for lower activity found in both cell lines for alpha-cedrol. Interestingly, beta-caryophyllene and linalool exhibited comparable IC(50) values to the commercial drug vinblastine on the ACHN cell line. This opens a new field of investigation to discover mechanisms responsible for the observed activity.

Primary treatment of choroidal amelanotic melanoma with photodynamic therapy.

The management of choroidal melanoma involves a delicate balance between preserving vision and preventing metastasis. Plaque brachytherapy has become standard management of most small lesions; however, this can result in radiation retinopathy and optic neuropathy. Transpupillary thermotherapy avoids these side-effects; however, it can also result in visual loss and its effectiveness is limited in amelanotic lesions. Photodynamic therapy with verteporfin has shown promise in animal studies of choroidal melanoma, and has recently been used in the management of lesions that have failed to respond to conventional therapy. The authors report a case of primary treatment of a small choroidal amelanotic melanoma with photodynamic therapy using verteporfin.

[Amelanotic malignant melanoma of the scalp clinically resembling a proliferating trichilemmal cyst]. / Amelanotisches Melanom der Kopfhaut klinisch imponierend als proliferierende Trichilemmalzyste.

HISTORY AND FINDINGS: A 37-year-old woman was admitted with an ulcerated tumor of the scalp together with an enlarged cervical lymph node. The clinical features resembled proliferative trichilemmal cyst. INVESTIGATIONS: Fine needle aspiration of the lymph node revealed an amelanotic metastasis of a malignant melanoma. TREATMENT AND COURSE: The entire tumor was removed and a radical neck-dissection performed. Histopathological examination confirmed the diagnosis of metastatic malignant melanoma. CONCLUSION: Proliferative trichilemmal cysts and malignant melanoma of the scalp are rare, but should be considered as differential diagnoses of neoplasm in this part of the body.

Amelanotic choroidal nevus and melanoma: cytology, tumor size, and pigmentation as prognostic indicators.

BACKGROUND: Choroidal nevi are fairly common lesions of the posterior pole that can sometimes transform into melanoma, and it is thought that most choroidal melanomas arise from preexisting nevi. Occasionally, these lesions present as nonpigmented or amelanotic variations of their pigmented counterparts. Recent studies suggest a relationship between tumor pigmentation and risk of growth and metastasis, with a better prognosis for lightly pigmented or amelanotic lesions. CASE REPORTS: A case of an amelanotic choroidal nevus and melanoma are presented. In Case 1, a 26-year-old white female was found to have a large amelanotic nevus in the right eye. After 7 years of periodic observation, the lesion has not changed. In Case 2, a 51-year-old white male was diagnosed with a large amelanotic melanoma in the left eye. Due to extensive involvement of the optic nerve, the patient underwent enucleation. Histological evaluation confirmed the lesion as a mixed-cell type malignant amelanotic melanoma. CONCLUSION: Management of choroidal nevi generally consists of periodic observation, and the most widely accepted management of choroidal melanoma is observation, radiotherapy, and transpupillary thermotherapy or enucleation. The therapeutic modality of choice for melanoma will vary depending on the size, growth, and location of the lesion. In addition, recent studies suggest an association between heavy tumor pigmentation, tumor size, cell type, and risk of metastasis. Although many variables will influence the final treatment option, pigmentation of the lesion should also be considered.

Combinatorial effects of monoclonal anti-p120 antibody (MAbp120), liposomes and hyperthermia on MCF-7 and LOX tumor cell lines.

The human nucleolar protein p120 is highly expressed in human cancers. Its high expression in breast cancer correlates with a poor prognosis, and its overexpression in 3T3 mouse fibroblasts causes malignant transformation. This study reports that a combination of monoclonal anti-p 120 antibody (MAbp120), liposomes (Lipo), and hyperthermia (HT) resulted in enhanced antitumor effects in cultured human breast adenocarcinoma (MCF-7) and human amelanotic melanoma (LOX) cells. Monoclonal antibody uptake and intracellular localization of the protein p120 were monitored by double labeling indirect immunofluorescence. Cell growth inhibition by the combination of MAbp120 + Lipo + HT was 65% for MCF-7 cells and 96% for LOX cells. When tested on LOX cells, monoclonal antibodies (MAbB23, MAbC23) to other nucleolar proteins (B23, C23) produced only slight cytotoxicity with similar treatment protocols.