curcumin and Carcinoma--Basal-Cell

Curcumin, or diferuloylmethane, is a crystalline compound which gives the East Asian spice turmeric its bright yellow color. The medicinal properties of this spice have been referenced in numerous countries and cultures throughout the world. Today, there is growing scientific evidence suggesting curcumin's utility in the treatment of chronic pain, inflammatory dermatoses, acceleration of wound closure, skin infections, as well as cosmetic ailments such as dyspigmentation. In addition, curcumin may have a protective role against various pollutants and cytotoxic agents, indicating that it may be beneficial in a mitigational or prophylaxis role. Although turmeric has been used for thousands of years in alternative medicine, curcumin has yet to emerge as a component of our mainstream dermatologic therapeutic armamentarium. Interestingly, curcumin provides an ideal alternative to current therapies because of its relative safety profile even at high doses. Although the advantageous properties of curcumin in medicine are well established, its therapeutic potential thus far has been limited because of its poor oral bioavailablity. Topical administration of curcumin can directly deliver it to the affected tissue making it useful in treating skin-related disorders. However, limitations still exist such as the cosmetically unpleasing bright yellow-orange color, its poor solubility, and its poor stability at a high pH. Here the current literature detailing the potential and current use of curcumin in dermatology is reviewed.

Topics: Anti-Bacterial Agents; Anti-Inflammatory Agents, Non-Steroidal; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Curcuma; Curcumin; Humans; Lichen Planus; Melanoma; Psoriasis; Scleroderma, Diffuse; Skin Diseases; Skin Neoplasms

There is considerable evidence that the excessive ultraviolet radiation B (UVB) from sunlight is implicated in skin damage, ultimately inducing the death of keratinocytes. The UVB-induced apoptotic pathways are tightly regulated by the balance between pro-apoptotic and anti-apoptotic molecules. Among them, modulations of Bcl2 family proteins are important to decide the fate of UVB-irradiated cells. If the apoptotic pathway does not work properly, the damaged cells have a chance to transform into a carcinoma, such as basal cell carcinoma or squamous cell carcinoma of the skin. To develop a strategy of inducing apoptosis of skin cancer cells, the current study was performed to investigate the apoptotic pathway, especially focused on Bcl2 family proteins, in curcumin or UVB-treated basal cell carcinoma cell lines. Our data showed that the decreased proliferation rates and apoptotic DNA laddering were clearly observed in UVB irradiation, but not markedly observed in curcumin treatment. The decreased expression of Bcl-XL, which is involved in protection of apoptosis, was also clearly observed in UVB-irradiated cells without markedly changing mRNA levels. However, the expression of Bax or Bcl2 were not markedly changed by UVB-irradiation. The decreased expression of Bcl-XL protein after UVB treatment was partially restored in the presence of MG132, which is an inhibitor of proteasome, implying that the down-regulation of Bcl-XL may be regulated by the proteasome-mediated degradation. Our data demonstrated that the expression of Bcl-XL protein was decreased by proteasome-mediated degradation prior to change of mRNA level in UVB-induced apoptotic basal cell carcinoma cell lines, thereby these results will offer fundamental information to develop a strategy of inducing apoptosis of skin cancer cells.

Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; bcl-Associated Death Protein; bcl-X Protein; Blotting, Western; Carcinoma, Basal Cell; Cell Line, Tumor; Cell Proliferation; Curcumin; DNA Fragmentation; Gene Expression; Humans; Proteasome Endopeptidase Complex; Reverse Transcriptase Polymerase Chain Reaction; Ultraviolet Rays

Curcumin, a potent antioxidant and chemopreventive agent, has recently been found to be capable of inducing apoptosis in human hepatoma and leukemia cells by way of an elusive mechanism. Here, we demonstrate that curcumin also induces apoptosis in human basal cell carcinoma cells in a dose- and time-dependent manner, as evidenced by internucleosomal DNA fragmentation and morphologic change. In our study, consistent with the occurrence of DNA fragmentation, nuclear p53 protein initially increased at 12 h and peaked at 48 h after curcumin treatment. Prior treatment of cells with cycloheximide or actinomycin D abolished the p53 increase and apoptosis induced by curcumin, suggesting that either de novo p53 protein synthesis or some proteins synthesis for stabilization of p53 is required for apoptosis. In electrophoretic mobility gel-shift assays, nuclear extracts of cells treated with curcumin displayed distinct patterns of binding between p53 and its consensus binding site. Supportive of these findings, p53 downstream targets, including p21(CIP1/WAF1) and Gadd45, could be induced to localize on the nucleus by curcumin with similar p53 kinetics. Moreover, we immunoprecipitated extracts from basal cell carcinoma cells with different anti-p53 antibodies, which are known to be specific for wild-type or mutant p53 protein. The results reveal that basal cell carcinoma cells contain exclusively wild-type p53; however, curcumin treatment did not interfere with cell cycling. Similarly, the apoptosis suppressor Bcl-2 and promoter Bax were not changed with the curcumin treatment. Finally, treatment of cells with p53 antisense oligonucleotide could effectively prevent curcumin-induced intracellular p53 protein increase and apoptosis, but sense p53 oligonucleotide could not. Thus, our data suggest that the p53-associated signaling pathway is critically involved in curcumin-mediated apoptotic cell death. This evidence also suggests that curcumin may be a potent agent for skin cancer prevention or therapy.

Topics: Apoptosis; Biomarkers; Carcinoma, Basal Cell; Cell Cycle; Curcumin; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; DNA-Binding Proteins; GADD45 Proteins; Humans; Intracellular Signaling Peptides and Proteins; Oligonucleotides, Antisense; Proteins; Tumor Cells, Cultured; Tumor Suppressor Protein p53