• Biomolecules & Therapeutics
• /
• v.21 no.2
• /
• pp.114-120
• /
• 2013

Most patients with mutant B-Raf melanomas respond to inhibitors of oncogenic B-Raf but resistance eventually emerges. To better understand the mechanisms that determine the long-term responses of mutant B-Raf melanoma cells to B-Raf inhibitor, we used chronic selection to establish B-Raf (V600E) melanoma clones with acquired resistance to the new oncogenic B-Raf inhibitor UI-152. Whereas the parental A375P cells were highly sensitive to UI-152 ($IC_{50}$ < $0.5{\mu}M$), the resistant sub-line (A375P/Mdr) displayed strong resistance to UI-152 ($IC_{50}$ < $20{\mu}M$). Immunofluorescence analysis indicated the absence of an increase in the levels of P-glycoprotein multidrug resistance (MDR) transporter in A375P/Mdr cells, suggesting that resistance was not attributable to P-glycoprotein overexpression. In UI-152-sensitive A375P cells, the anti-proliferative activity of UI-152 appeared to be due to cell-cycle arrest at $G_0/G_1$ with the induction of apoptosis. However, we found that A375P/Mdr cells were resistant to the apoptosis induced by UI-152. Interestingly, UI-152 preferentially induced autophagy in A375P/Mdr cells but not in A375P cells, as determined by GFP-LC3 puncta/cell counts. Further, autophagy inhibition with 3-methyladenine (3-MA) partially augmented growth inhibition of A375P/Mdr cells by UI-152, which implies that a high level of autophagy may protect UI-152-treated cells from undergoing growth inhibition. Together, our data implicate high rates of autophagy as a key mechanism of acquired resistance to the oncogenic B-Raf inhibitor, in support of clinical studies in which combination therapy with autophagy targeted drugs is being designed to overcome resistance.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.19
• /
• pp.8161-8169
• /
• 2014

Background: Cancer stem cells (CSC) are populations of cells responsible for tumor initiation, progression and therapeutic resistance in many cancers. In the present study, we aimed to investigate the expression pattern and clinical significance of two CSC markers, CD133 and Nestin, in a series of skin tumors. Materials and Methods: One hundred and thirteen paraffin blocks from skin cancers including 16 (14%) cases of melanoma, 37 (33%) of squamous cell cancer (SCC) and 60 (53%) of basal cell cancer (BCC) were collected and assembled in a tissue microarray (TMA). The samples were immunohistochemically examined for the expression of CD133 and Nestin. Expression of these markers was also correlated with clinicopathological parameters. Results: A significant difference was observed in the expression of CD133 and Nestin in melanomas, SCC and BCC (p value=0.001). Furthermore, the level of expression was significantly higher in the melanomas compared to the SCC and BCC tumors. Expression of CD133 in the melanoma was significantly associated with increased tumor invasiveness (p value=0.05), a higher rate of metastasis (p value=0.04) and the presence of ulceration (p value=0.02). Increased expression of Nestin was observed in metastatic melanoma (p value=0.04), while no statistically significant correlation was found with other clinicopathological parameters including Breslow thickness, Clark level and ulceration. Conclusions: Elevated expression levels of CD133 and Nestin in the melanomas are associated with advanced disease, with more aggressive and metastatic skin tumors. Therefore, these markers could be potential therapeutic targets for malignant tumors of the skin.

• Journal of Pharmaceutical Investigation
• /
• v.41 no.4
• /
• pp.205-210
• /
• 2011

Genistein (GT), a major isoflavone found in soybeans, has a potent antioxidant effect that protects the skin from UV-induced damages and malignant melanoma. In order to enhance the cellular uptake of GT, liposome/Tat complexes were prepared by an electrostatic interaction of anionic liposome (DMPC/DCP, 9:1 in molar ratio) with Tat peptide (0.02 to 0.08 mole), one of the well-known cell penetrating peptide (CPP). As the amount of Tat increased, the size increased but the zeta potential decreased. In vitro release study with dialysis membrane elicited GT release from liposomal preparations in a controlled manner. The addition of Tat increased GT release, especially for the initial period. In the cellular uptake study by incubating B16 melanoma cells with various liposomal preparations containing GT, B16 melanoma cells demonstrated a time-dependent increase of drug accumulation. Compared to the aqueous GT suspension, intracellular uptake was substantially enhanced by anionic liposomal formulation and further increased by the complex formulation. Therefore, liposome/ Tat complex might be a good candidate for facilitating intracellular drug delivery.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.3795-3802
• /
• 2012

Cochinchina momordica seeds (CMS) have been widely used due to antitumor activity by Mongolian tribes of China. However, the details of the underlying mechanisms remain unknown. In the present study, we found that an EtOAc (ethyl ester) extract of CMS (CMSEE) induced differentiation and caused growth inhibition of melanoma B16 F1 cells. CMSEE at the concentration of $5-200{\mu}g/ml$ exhibited strongest anti-proliferative effects on B16 F1 cells among other CMS fractions (water or petroleum ether). Moreover, CMSEE induced melanoma B16 F1 cell differentiation, characterized by dendrite-like outgrowth, increasing melanogenesis production, as well as enhancing tyrosinase activity. Western blot analysis showed that sustained phosphorylation of p38 MAP accompanied by decrease in ERK1/2 and JNK dephosphorylation were involved in CMSEE-induced B16 F1 cell differentiation. Notably, 6 compounds that were isolated and identified may be responsible for inducing differentiation of CMSEE. These results indicated that CMSEE contributes to the differentiation of B16 F1 cells through modulating MAPKs activity, which may throw some light on the development of potentially therapeutic strategies for melanoma treatment.

• The Korea Journal of Herbology
• /
• v.28 no.3
• /
• pp.69-74
• /
• 2013

Objectives : Since hypopigmentation is known to increase the risk of skin cancer, melanogenesis in the skin needs to be regulated. Here, we evaluated the melanogenesis stimulatory effects of a modified Goagium herbal remedy (HR) and HR+ox bile (Bos taurus domesticus) extract (OBE) to address hypopigmentation disorders. Methods : B16F10 melanoma cells were treated with different dosages of HR and HR+OBE for 24 to 48 h after 1 h of 10 nM ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH). After the treatment, cell viability, tyrosinase activity, melanin synthesis and the expression of genes related to melanin synthesis were measured and the regulation of the ${\alpha}$-MSH signalling through cAMP responding element binding protein (CREB) was determined. Results : HR and HR+OBE with the ranges of $15{\sim}100{\mu}g/mL$ did not affect cell viability in melanoma cells. The 1 h treatment of HR+OBE (50 and $100{\mu}g/mL$) potentiated the phosphorylation of CREB by enhancing ${\alpha}$-MSH signaling and its 24 h treatment increased CREB expression. Consistent with CREB potentiation, their treatment for 24 h, the expression of microphthalmia-associated transcription factor (MIFT), tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 were increased in realtime PCR. Ultimately, the 48 h treatment of HR+OBE (50 and $100{\mu}g/mL$) increased tyrosniase activity and melanin contents in the melanoma cells in comparison to the control. Conclusions : HR+OBE (50 and $100{\mu}g/mL$) increases melanin synthesis in B16F10 melanoma cells via the stimulation of tyrosinase activity and expression of MIFT, tyrosinase, TRP-1 and TRP-2. HR+OBE can be used as the a possible treatment for hypopigmentation of the skin.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.3
• /
• pp.1163-1169
• /
• 2014

Astragalus, a commonly used traditional Chinese medicine, has exhibited antitumor actions in patients. In this study, in vitro and in vivo antitumor effects of astragalus and synergistic antitumor efficacy in combination with pterostilbene were investigated. Melanoma cells were treated with pterostilbene (Pt), graduated doses of astragalus injection (AI), or these in combination. Cell viability was measured using a MTT assay. Released nucleosomes and caspase activity were measured using enzyme-linked immunosorbent assay. Growth inhibition in vitro and in vivo was also assessed. Analysis of variance and t tests were used for statistical analysis. Significant reduction (p<0.05) in cellular proliferation were observed with AI and AI-Pt in a time- and concentration-dependent manner. Apoptosis and caspase-3/7 activity were significantly increased by AI and AI-Pt treatment (p<0.05). In vivo, AI inhibited melanoma tumor growth, with inhibition rates ranging from 36.5 to 62.3%, by inducing apoptosis via up-regulation Bax expression and the Bax/Bcl-2 ratio and down-regulating Bcl-2 expression. AI significantly inhibits the growth of melanoma in vitro and in vivo by inducing apoptosis. These data suggest that combined treatment of astragalus with pterostilbene enhances antitumor efficacy.

• KSBB Journal
• /
• v.32 no.3
• /
• pp.187-192
• /
• 2017

In this study, we investigated the effect of Rumex axetosella, Sonchus oleraceus and Euphoibia jolkini extracts on tyrosinase activity and melanin production as natural products of whitening functional cosmetics. To measure the melanin production, 50, 100, $200{\mu}g/mL$ of Rumex axetosella, Sonchus oleraceus and Euphoibia jolkini extracts were treated on ${\alpha}-MSH$ treated B16F10 melanoma cells, respectively. Melanin contents in ${\alpha}-MSH$ treated B16F10 melanoma cells were decreased by 41.5, 51.11, and 61% in $200{\mu}g/mL$ treatment compared to none treatment, respectively. In addition, the intracellular tyrosinase activity was decreased after treatments with all extracts. Furthermore, $100{\mu}g/mL$ of Euphoibia jolkini extract was decreased 81.5% of melanin production in B16F10 melanoma cells. When the three extracts were compared, Euphoibia jolkini extract was considered to be the most functional material for whitening effect.

• Archives of Plastic Surgery
• /
• v.40 no.5
• /
• pp.627-629
• /
• 2013

The ReCell system (Avita Medical) is a cell culture product that allows the immediate processing of a small split-thickness skin biopsy to produce a complete population of cells including keratinocytes, melanocytes, Langerhans cells and fibroblasts. This series is the first to highlight the reconstructive applications of ReCell following ablative skin cancer surgery. The ReCell system was utilized for three patients following skin cancer excision. In two cases, the cells were applied to forehead flap donor sites following nasal reconstruction. In one case, the cells were applied to the calvarial periosteum following wide local excision of a melanoma scar. Assessment of the treated area was performed using the patient and observer scar assessment scale after 1 year. The Patient and Observer Scar Assessment Scale (POSAS) scores for the 2 patients treated with ReCell following forehead flap surgery were 22 and 32. The score for the patient that underwent wide local excision of a melanoma scar was 45. The absence of a donor site, accelerated healing and the satisfactory aesthetic appearance of the mature scars in this series suggest that ReCell may play a useful role in reconstruction following skin cancer excision.

• BMB Reports
• /
• v.31 no.4
• /
• pp.339-344
• /
• 1998

The plant flavonoids, including apigenin which is found in especially high concentrations in edible plants, are reported to protect against chronic diseases including several types of cancer. We observed that apigenin inhibited not only the growth of human melanoma cell line SK-MEL 28 but also the telomerase activity. We also noted the telomerase activity inhibition by genistein, a tyrosine kinase inhibitor found in soybean, which suggests that the telomerase activity of SK-MEL 28 cells may be regulated by the protein phosphorylation. Furthermore, we observed that apigenin induced SK-MEL 28 cell apoptosis with p53 upregulation. Taken together, our results indicate that apigenin plays a role as an antimelanoma component in edible plants.

• Korean Journal of Pharmacognosy
• /
• v.31 no.1
• /
• pp.77-81
• /
• 2000

The MeOH extract of Notopterygium incisum showed a strong cytotoxicity against B16 murine melanoma cell line. From this extract three furanocoumarins including bergamottin, isoimperatorin, notopterol and one polyacetylenic compound (falcarindiol) together with one phenylpropanoid (caffeic acid methyl ester) and one triterpenoid (pregnenolone) were isolated. The isolated compounds were evaluated for cytotoxic activity against four kinds of cancer cell lines, e.g. P388 (murine lymphocytic leukemia), B16 (murine melanoma), A549 (human lung carcinoma) and SK-OV-3 (human ovarian cancer). Among the isolates, falcarindiol and caffeic acid methyl ester expressed a significant antiproliferative activity against all tested cell lines.