No abstract

We investigated the anti-tumor efficiency of sonodynamic therapy (SDT) on human tongue squamous carcinoma SAS cell line using low intensity ultrasound (LIU) of 0.6 and 0.8 W/cm², plus 5-aminolevulinic acid (ALA). Xenograft in vivo experiments using Balb/ca nude mice and MTT assays in vitro showed that ALA-LIU therapy significantly suppressed the proliferation of SAS cells. ALA-LIU therapy markedly enhanced SAS cell apoptosis rate compared to LIU alone. Based on TEM and fluorescence microscopy observations, there are notably morphology changes and seriously swollen mitochondria in xenograft tissues, and ALA-induced PpIX bond strongly to mitochondria of SAS cells. Immunohistochemical staining and western blotting demonstrated upregulation of Bax, cytochrome c and caspase-3, and downregulation of Bcl-2 for both in vivo and in vitro cases after ALA-LIU treatment. Increase of reactive oxygen species (ROS) in the ALA-LIU treatment groups were found using 2, 7-dichlorofluorescin diacetate (DCFH-DA) staining. Administration of the ROS scavenger, N-acetylcysteine (NAC), suppressed ALA-LIU-induced apoptosis and the expression of mitochondria apoptosis-related proteins, which confirmed that the ALA-LIU induced SAS cell apoptosis is through the generation of ROS. The process initially damaged mitochondria, activated pro-apoptotic factors Bax and cytochrome c and supressed the anti-apoptotic factor Bcl-2, activated caspase-3 to executed apoptosis through mitochondrial signaling pathway.

Eugenol can be separated from the oil extract of clove bud, and has many pharmacological functions such as anticancer and transdermal absorption. HER2/PI3K-AKT is a key signaling pathway in the development of breast cancer. In this study, 80 μM eugenol could significantly inhibit the proliferation of HER-2 positive MCF-10AT cells and the inhibition rate was up to 32.8%, but had no obvious inhibitory effect on MCF-7 and MCF-10A cells with HER2 weak expression. Eugenol also significantly induced human breast precancerous lesion MCF-10AT cell apoptosis and cell cycle S-phase arrest, but the biological effects nearly disappeared after HER2 over-expression through transfecting pcDNA3.1-HER2. In MCF-10AT cells treated by 180 μM eugenol, the protein expressions of HER2, AKT, PDK1, p85, Bcl2, NF-κB, Bad and Cyclin D1 were decreased and the decreased rates were respectively 63.0%, 60.0%, 52.9%, 62.9%, 37.1%, 47.2%, 61.7%, 59.1%, while the p21, p27 and Bax expression were increased by 4.48-, 4.76- and 2.57-fold respectively. In the rat models of breast precancerous lesion, 1 mg eugenol for external use significantly inhibited the progress of breast precancerous lesion and the occurrence rate of breast precancerous lesions and invasive carcinomas was decreased by about 30.5%. Furthermore eugenol for external (1 mg) markedly decreased the protein expressions of HER2 (62.9%), AKT (58.6%), PDK1 (56.4%), p85 (54.3%), Bcl2 (59.3%), NF-κB (65.7%), Bad (64.0%), Cyclin D1 (43.0%), while p21, p27 and Bax protein expressions were respectively increased 1.83-, 2.52- and 2.51-fold. The results showed eugenol could significantly inhibit the development of breast precancerous lesions by blocking HER2/PI3K-AKT signaling network. So eugenol may be a promising external drug for breast precancerous lesions.

Sonodynamic therapy (SDT) is an innovative modality for cancer treatment. But the biological effect of SDT on oral squamous cell carcinoma has not been studied. Our previous study has shown that endo-Protoporphyrin IX based SDT (ALA-SDT) could induce apoptosis in human tongue squamous carcinoma SAS cells through mitochondrial pathway. Herein, we investigated the effect of exo- Protoporphyrin based SDT (PpIX-SDT) on SAS cells in vitro and in vivo. We demonstrated that PpIX-SDT increased the ratio of cells in the G2/M phase and induced 3–4 times more cell apoptosis compared to sonocation alone. PpIX-SDT caused cell membrane damage prior to mitochondria damage and upregulated the expression of Fas and Fas L, while the effect was suppressed if cells were pre-treated with p53 inhibitor. Additionally, we examined the SDT-induced cell apoptosis in two cell lines with different p53 status. The increases of p53 expression and apoptosis rate in wild-type p53 SAS cells were found in the SDT group, while p53-mutated HSC-3 cells did not show such increase. Our data suggest that PpIX-SDT suppress the proliferation of SAS cells via arresting cell cycle at G2/M phase and activating the extrinsic Fas-mediated membrane receptor pathway to induce apoptosis, which is regulated by p53.

The mechanisms underlying the effects of COX-2 on tumor lymphangiogenesis remain largely undefined. Here, the human lung cancer cell lines A549, 95D, Anip973, and AGZY83-a with different metastatic capacities were investigated by immunostaining, western blotting, and real-time RT-PCR. We observed increased expressions of COX-2 and VEGF-C in the three highly metastatic cell lines compared with the less metastatic AGZY83-a cell line. The COX-2-specific inhibitor Celecoxib suppressed VEGF-C expression whereas the main COX-2 metabolite PGE 2 elevated VEGF-C expression in Anip973 and AGZY83-a cells in positive and negative experiments. To determine the functional link to COX-2 more specifically and elucidate the mechanistic pathway, we used a siRNA to knock down the high COX-2 expression in Anip973 cells and transfected a COX-2 cDNA to enhance the low COX-2 expression in AGZY83-a cells, and then treated the cells with EP1/EP4 agonists or antagonists, respectively. The results revealed that the EP1/EP4 agonists significantly increased VEGF-C production in the COX-2-knockdown Anip973 cells. In contrast, the EP1/ EP4 antagonists diminished VEGF-C production in the COX-2-overexpressing AGZY83-a cells. Furthermore, animal models provided evidence that Celecoxib decreased VEGF-C expression, lymphangiogenesis, and lymph node metastases in Anip973 cells, whereas PGE 2 treatment increased the same factors in the parental AGZY83-a cells. A positive correlation between COX-2 and VEGF-C was also confirmed in vivo. The present data suggest that COX-2 regulates VEGF-C expression via the PGE 2 pathway, and that EP1/EP4 receptors are involved in PGE 2 -mediated VEGF-C production. Thus, COX-2 may represent a candidate gene for blocking tumor lymphangiogenesis and lymph node metastasis. Anat Rec, 293:1838Rec, 293: -1846