Shikonin inhibits prostate cancer cells metastasis by reducing matrix metalloproteinase-2/-9 expression via AKT/mTOR and ROS/ERK1/2 pathways.

Metastasis is one of the most important factors related to prostate cancer therapeutic efficacy. In previous studies, shikonin, an active naphthoquinone isolated from the Chinese medicine Zi Cao, has various anticancer activities both in vivo and in vitro. However, the mechanisms underlying shikonin's anticancer activity are not fully elucidated on prostate cancer cells. In the present study, we aimed to investigate the potential effects of shikonin on prostate cancer cells and the underlying mechanisms by which shikonin exerted its actions. With cell proliferation, flow cytometric cell cycle, migration and invasion assays, we found that shikonin potently suppressed PC-3 and DU145 cell growth by cell cycle arrest at the G2 phase and metastasis in a dose-dependent manner. Mechanically, we presented that shikonin could suppress the metastasis of PC-3 and DU145 cells via inhibiting the matrix metalloproteinase-2 (MMP-2) and MMP-9 expression and activation. In addition, shikonin significantly decreased the phosphorylation of AKT and mTOR in a dose-dependent manner while it induced extracellular signal-regulated kinase (ERK), p38 mitogen activated protein kinase (MAPK) and c-Jun N terminal kinase (JNK) phosphorylation. Further investigation of the underlying mechanism revealed that shikonin also induced the production of reactive oxygen species (ROS) that was reversed by the ROS scavenger dithiothreitol (DTT). Additionally, DTT reversed the shikonin induced activation of ERK1/2, thereby maintaining MMP-2 and MMP-9 expression and restoring cell metastasis. Together, shikonin inhibits aggressive prostate cancer cell migration and invasion by reducing MMP-2/-9 expression via AKT/mTOR and ROS/ERK1/2 pathways and presents a potential novel alternative agent for the treatment of human prostate cancer.

Chen Y ，Zheng L ，Liu J ，Zhou Z ，Cao X ，Lv X ，Chen F ... -  《-》

Shikonin attenuates lung cancer cell adhesion to extracellular matrix and metastasis by inhibiting integrin β1 expression and the ERK1/2 signaling pathway.

Integrin β1 facilitates cancer cell adhesion, migration and metastasis by activating intracellular signaling pathways including the ERK and PI3K signaling pathways. In previous studies, shikonin, an active naphthoquinone isolated from the Chinese medicine Zi Cao (gromwell), showed effective anticancer activity both in vivo and in vitro. However, the mechanisms underlying shikonin's anticancer activity are not fully elucidated. Increasing evidence indicates that shikonin inhibits tumor metastasis, but little is known about the effect of shikonin on lung cancer cells. To better understand the anti-metastatic role of shikonin in lung cancer, in this study we sought to investigate the effect of shikonin on lung cancer cell proliferation, adhesion to extracellular matrices (ECM), migration and invasion in non-small cell lung cancer A549 cells. We also sought to investigate the molecular mechanisms underlying shikonin's anticancer effects. Here we showed that when non-small cell lung cancer A549 cells were treated with shikonin for 24h, 8.0μM shikonin significantly inhibited cell proliferation, while cells treated with less than 2.0μM shikonin for 24h significantly suppressed cell adhesion to the ECM, invasion and migration in a dose-dependent manner. Moreover, real-time PCR and Western blot analysis showed that shikonin led to a reduction in the expression of integrin β1 at the mRNA and protein levels. Further elucidation of the mechanisms involved revealed that shikonin repressed the phosphorylation of extracellular signal-regulated kinase (ERK1/2). Taken together, our findings provide new evidence that shikonin suppresses lung cancer invasion and metastasis by inhibiting integrin β1 expression and the ERK1/2 signaling pathway.

Wang H ，Wu C ，Wan S ，Zhang H ，Zhou S ，Liu G ... -  《-》

Reactive oxygen species-mediated activation of the Akt/ASK1/p38 signaling cascade and p21(Cip1) downregulation are required for shikonin-induced apoptosis.

Ahn J ，Won M ，Choi JH ，Kim YS ，Jung CR ，Im DS ，Kyun ML ，Lee K ，Song KB ，Chung KS ... -  《-》

Shikonin Inhibits the Migration and Invasion of Human Glioblastoma Cells by Targeting Phosphorylated β-Catenin and Phosphorylated PI3K/Akt: A Potential Mechanism for the Anti-Glioma Efficacy of a Traditional Chinese Herbal Medicine.

Zhang FY ，Hu Y ，Que ZY ，Wang P ，Liu YH ，Wang ZH ，Xue YX ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

Antitumor effects of the novel quinazolinone MJ-33: inhibition of metastasis through the MAPK, AKT, NF-κB and AP-1 signaling pathways in DU145 human prostate cancer cells.

Hour MJ ，Tsai SC ，Wu HC ，Lin MW ，Chung JG ，Wu JB ，Chiang JH ，Tsuzuki M ，Yang JS ... -  《-》