shikonin and Carcinoma--Squamous-Cell

Shikonin, a naphthoquinone pigment isolated from the Chinese herbal Zicao, has been shown to exhibit antioxidant and anticancer effects. In the present study, we investigated the antiproliferative and pro-apoptotic effects of shikonin on A431 cells and explored the underlying molecular mechanisms. In the present study, our results showed that shikonin significantly inhibited the growth of A431 cells in a concentration- and time-dependent manner, and caused cell cycle arrest by upregulation of p21 and p27, and downregulation of cyclins and cyclin-dependent kinases. In addition, shikonin evidently induced apoptosis due to decreasing Bcl-2 expression, increasing Bax expression, activating caspase and inactivating NF-κB, while pretreatment with a pan-caspase inhibitor Z-Asp-CH2-DCB abrogated shikonin-induced apoptosis. Moreover, EGF could significantly increase the NF-κB DNA-binding activity and reversed the shikonin-induced inactivation of NF-κB. As anticipated AG1478 (EGFR inhibitor) and Bay11-7082 (NF-κB inhibitor) blocked EGF-reversed the inactivation of NF-κB induced by shikonin. Our data also showed that EGF could evidently reverse the shikonin-induced decreases in cell viability and increases in apoptosis. Then, the NF-κB inhibitors such as Bay11-7082, SN50, Helenalin and the EGFR inhibitor AG1478 and its downstream inhibitor such as PI3K inhibitor LY294002 and STAT3 inhibitor Stattic dramatically blocked EGF-reversed decreases in cell viability and increases in apoptosis induced by shikonin. Collectively, our findings indicated that shikonin inhibited cell growth and caused cell cycle arrest of the A431 cells through the regulation of apoptosis. Moreover, these effects were mediated at least partially by suppressing the activation of the EGFR-NF-κB signaling pathways.

Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Cycle Checkpoints; Cell Line, Tumor; Dose-Response Relationship, Drug; ErbB Receptors; Humans; Naphthoquinones; Neoplasm Proteins; NF-kappa B

To investigate the role of NF-kappaB signal transduction pathway in apoptosis induced by shikonin in human tongue squamous cell carcinoma Tca-8113 cell line.. Expression of IkappaBa, phosphatase-IkappaBa, bcl-2 and Bax proteins were detected by Western blot, NF-kappaB DNA-binding activity was detected by electrophoretic mobility shift analysis (EMSA), and activities of caspase 3, caspase 8 and caspase 9 were analyzed by enzyme linked immunosorbent assay(ELISA). The data was analyzed by one-way ANOVA test and t test using SPSS12.0 software package.. The expression of phosphatase-IkappaBa protein and the nuclear NF-kappaB DNA-binding activity was significantly decreased in shikonin treated cells by Western and EMSA. Bcl-2 protein expression was also decreased in the process. The activity of all the three proteases was elevated and pancaspase inhibitor Z-Asp-CH2-DCB could protect Tca8113 cells from shikonin-induced apoptosis(P=0.02).. Anti-tumor effects of shikonin in Tca-8113 cells act at least partially through the inactivation of NF-kappaB pathway and subsequent activation of protease caspase family. Pharmacologic inhibition of the NF-kappaB activity by shikonin might be a powerful treatment option for OSCC.

Topics: Apoptosis; Aspartic Acid; Blotting, Western; Carcinoma, Squamous Cell; Cell Line, Tumor; Humans; Mouth Neoplasms; Naphthoquinones; NF-kappa B; Signal Transduction

Shikonin, a naphthoquinone pigment isolated from the Chinese herbal therapeutic, Zicao, has been shown to exhibit antioxidant and anticancer effects. In this study, its ability to induce apoptosis in cultured Tca-8113 oral cancer cells was studied. Treatment of the Tca-8113 cells with a variety of concentrations of Shikonin (10-40 microm) resulted in dose- and time-dependent sequences of events marked by apoptosis, as shown by the loss of cell viability, chromatin condensation, internucleosomal DNA fragmentation and sub-G1 phase accumulation. Furthermore, apoptosis in the Tca-8113 cells was accompanied by the activation of protease caspase-8, -9, -3 and low expression of Bcl-2 protein. Interestingly, inactivation of the NF-kappaB pathway was found in shikonin-induced apoptosis in Tca-8113 cells. These results raise the possibility that the anti-tumor effects of Shikonin in Tca-8113 cells are at least partly through the inactivation of the NF-kappaB pathway and subsequent activation of protease caspase family. Pharmacological inhibition of the NF-kappaB activity by Shikonin might be a powerful treatment option for OSCC in which activation of NF-kappaB plays a critical role in tumor growth and progression.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Antibodies, Monoclonal; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Squamous Cell; Caspases; Cell Cycle; Cell Line, Tumor; Cell Proliferation; DNA; DNA Fragmentation; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Gene Expression; Humans; Naphthoquinones; NF-kappa B; Proto-Oncogene Proteins c-bcl-2; Time Factors

Shikonin isolated from the roots of the Chinese herb Lithospermum erythrorhizon has been associated with anti-inflammatory properties. We evaluated shikonin's chemotherapeutic potential and investigated its possible mechanism of action in a human cutaneous neoplasm in tissue culture. Shikonin preferentially inhibits the growth of human epidermoid carcinoma cells concentration- and time-dependently compared to SV-40 transfected keratinocytes, demonstrating its anti-proliferative effects against this cancer cell line. Additionally, shikonin decreased phosphorylated levels of EGFR, ERK1/2 and protein tyrosine kinases, while increasing phosphorylated JNK1/2 levels. Overall, shikonin treatment was associated with increased intracellular levels of phosphorylated apoptosis-related proteins, and decreased levels of proteins associated with proliferation in human epidermoid carcinoma cells.

Topics: Carcinoma, Squamous Cell; Cell Division; Enzyme Inhibitors; ErbB Receptors; Humans; MAP Kinase Signaling System; Naphthoquinones; Phosphorylation; Protein-Tyrosine Kinases; Signal Transduction; Tumor Cells, Cultured

The shikonin mixture was used for 19 cases of later-stage lung cancer who were not the candidates for operation, radiotherapy and chemotherapy. The clinical observation showed that shikonin mixture could inhibit the growth of lung cancer and improve the immune function of the body. The tumors were reduced over 25% in diameter. The effective rate was 63.3%, remission rate 36.9%, survival rate of one year 47.3%. The intermedium survival period was about 10 months, including adenocarcinoma 10 months, squamous carcinoma 12 months. After treatment the life quality of patients were greatly improved. The patients got better appetite and their body weights were increased. They could manage themselves in daily life. The Karnofsky scores were enhanced by 20. The authors also observed that shikonin mixture could relieve such symptoms as cough, bloody sputum and chest pain caused by lung cancer. The levels of cells and interleukin-2 were increased (P less than 0.001). It had no harmful effects on peripheral blood picture, heart, kidney and liver. Shikonin mixture is safe and effective for later-stage cancer.

Topics: Adenocarcinoma; Adult; Antineoplastic Agents, Phytogenic; Carcinoma, Bronchogenic; Carcinoma, Squamous Cell; Female; Ginsenosides; Humans; Interleukin-2; Killer Cells, Natural; Lung Neoplasms; Male; Middle Aged; Naphthoquinones; Saponins