In vitro antimetastatic potential of pseudolaric acid B in HSC-3 human tongue squamous carcinoma cell line.

OBJECTIVE: Pseudolaric acid B (PAB) is a novel diterpenoid derived from the traditional Chinese medicinal herb Cortex pseudolaricis that exerts anticancer, anti-inflammatory, and immunomodulatory properties. While the anticancer potential of PAB has been studied, its effects on metastasis have not been well-studied. This study aims to determine the inhibitory effects of PAB on HSC-3 human tongue squamous cell carcinoma (TSCC) cell line. DESIGN: Cell viability and soft agar colony formation assays were conducted to assess cellular proliferation and in vitro tumorigenic capacity of TSCC cells, respectively. Additionally, wound healing, transwell migration, and invasion assays were conducted to monitor the aggressive behavior of TSCC cells. Furthermore, Western blotting analysis was conducted to reveal the signaling pathways involved in the modulation of epithelial-mesenchymal transition (EMT). RESULTS: The migratory and invasive capacities of HSC-3 cells were suppressed by PAB irrespective of their proliferation states. PAB's effects on EMT involved upregulation of E-cadherin expression and downregulation of Twist; these were concomitantly accompanied by downregulated phosphorylation of epidermal growth factor receptor (EGFR). CONCLUSIONS: PAB suppresses human TSCC in vitro by regulating Twist/E-cadherin through the EGFR signaling pathway. PAB may have potential as a candidate antimetastatic drug for TSCC treatment.

Apoptosis induced by methanol extract of Potentilla discolor in human mucoepidermoid carcinoma cells through STAT3/PUMA signaling axis.

Potentilla discolor has been used in traditional Chinese medicine for the treatment of hyperglycemia. However, the potential role of Potentilla discolor against cancer and its mode of action remain to be fully elucidated. The present study explored the apoptotic effect of methanol extract of Potentilla discolor (MEPD) in human mucoepidermoid carcinoma (MEC) cell lines of salivary glands. MEPD markedly suppressed the growth and induced apoptotic cell death in MC3 and YD15 cells. MEPD treatment significantly upregulated the expression of PUMA and reduced STAT3 phosphorylation. Overexpression of STAT3 partially recovered the growth of MEC cells inhibited by MEPD. In addition, dephosphorylation of STAT3 by cryptotanshinone (a potent STAT3 inhibitor) was sufficient to inhibit the growth of MEC cells and induce apoptosis via affecting PUMA protein. These results suggest that MEPD has a potential anticancer property via the STAT3/PUMA signaling axis in human MEC cells of salivary gland.

Silymarin and its active component silibinin act as novel therapeutic alternatives for salivary gland cancer by targeting the ERK1/2-Bim signaling cascade.

PURPOSE: Approximately 20% of all salivary gland cancer patients who are treated with current treatment modalities will ultimately develop metastases. Its most common form, mucoepidermoid carcinoma (MEC) is a highly aggressive tumor with an overall 5-year survival rate of ~30%. Until now, several chemotherapeutic drugs have been tested for the treatment of salivary gland tumors, but the results have been disappointing and the drugs often cause unwanted side effects. Therefore, several recent studies have focused on the potential of alternative and/or complementary therapeutic options, including the use of silymarin. METHODS: The effects of silymarin and its active component silibinin on salivary gland cancer-derived MC3 and HN22 cells and their underlying molecular mechanisms were examined using trypan blue exclusion, 4'-6-diamidino-2-phenylindole (DAPI) staining, Live/Dead, Annexin V/PI staining, mitochondrial membrane potential (ΔΨm) measurement, quantitative RT-PCR, soft agar colony formation and Western blotting analyses. RESULTS: We found that silymarin and silibinin dramatically increased the expression of the pro-apoptotic protein Bim in a concentration- and time-dependent manner and, concomitantly, induced apoptosis in MC3 and HN22 cells. We also found that ERK1/2 signaling inhibition successfully sensitized these cells to the apoptotic effects of silymarin and silibinin, which indicates that the ERK1/2 signaling pathway may act as an upstream regulator that modulates the silymarin/silibinin-induced Bim signaling pathway. CONCLUSIONS: Taken together, we conclude that ERK1/2 signaling pathway inhibition by silymarin and silibinin increases the expression of the pro-apoptotic Bcl-2 family member Bim which, subsequently, induces mitochondria-mediated apoptosis in salivary gland cancer-derived cells.

In Vitro Assessment of the Anticancer Potential of Evodiamine in Human Oral Cancer Cell Lines.

Evodiamine, a bioactive alkaloid, has been regarded as having antioxidant, antiinflammatory, and anticancer properties. In the present study, we explored the effects of evodiamine on cell growth and apoptosis in human oral cancer cell lines. Our data revealed that evodiamine significantly inhibited the proliferation of human oral cancer cells and resulted in the cleavages of PARP (poly (ADP-ribose) polymerase) and caspase-3, in addition to causing the typical characteristics of apoptosis. Evodiamine also increased Bax protein levels and caused translocation of Bax into mitochondria and Bax oligomerization. In addition, evodiamine decreased expression of myeloid cell leukemia (Mcl-1) at the transcriptional modification, and knockdown of Mcl-1 clearly resulted in an increase in expression of Bax and active Bax, resulting in induction of apoptosis. Evodiamine reduced expression of phosphorylated AKT, and LY294002 potentiated evodiamine-induced apoptosis by regulating Mcl-1 protein. Our results suggest that evodiamine induces apoptosis in human oral cancer cells through the AKT pathway. These findings provide a rationale for its clinical application in the treatment of oral cancer.

Extracellular signal­regulated kinase inhibition is required for methanol extract of Smilax china L.­induced apoptosis through death receptor 5 in human oral mucoepidermoid carcinoma cells.

Smilax china L., a well­known Chinese traditional medicine, has been used as an anti­inflammatory, anti­cancer and analgesic agent, but its role has not yet been fully elucidated in oral mucoepidermoid carcinoma (MEC). The present study focused on addressing the anticancer activity and molecular mechanism of methanol extract of Smilax china L. (MESC) in MC­3 human oral MEC cells. The results indicated that MESC inhibited cell growth and induced apoptosis in MC­3 cells. These observations were found to correlate with increases in truncated BH3 interacting­domain death agonist and B­cell lymphoma 2 (Bcl­2) interacting mediator of cell death, but not Bcl­2 homologous antagonist killer, Bcl­2­associated X protein, Bcl­2, B­cell lymphoma­extra large and induced myeloid leukemia cell differentiation protein levels. MESC also damaged the mitochondrial membrane potential, cleaved caspase­8 protein and increased death receptor 5 (DR5) protein levels by enhancing the stability of DR5 protein. Furthermore, MESC affected the phosphorylation of extracellular signal­regulated kinase (ERK) only, and did not affect c­Jun N­terminal kinase or p38 phosphorylation. Co­treatment with MESC and an ERK inhibitor (PD98059) significantly increased the expression of DR5 to induce apoptosis in MC­3 cells. Therefore, these results suggest that MESC may induce apoptosis via the ERK pathway and may be a potential anticancer drug candidate against human oral MEC.