Actein Inhibits Cell Proliferation and Migration in Human Osteosarcoma

In Vitro and In Vivo Imaging-Based Evaluation of Doxorubicin Anticancer Treatment in Combination with the Herbal Medicine Black Cohosh

As a substitution for hormone replacement therapy, many breast cancer patients use black cohosh (BC) extracts in combination with doxorubicin (DOX)-based chemotherapy. In this study, we evaluated the viability and survival of BC- and DOX-treated MCF-7 cells. A preclinical model of MCF-7 xenografts was used to determine the influence of BC and DOX administration on tumor growth and metabolism. The number of apoptotic cells after incubation with both DOX and BC was significantly increased (~100%) compared to the control. Treatment with DOX altered the potential of MCF-7 cells to form colonies; however, coincubation with BC did not affect this process. In vivo, PET-CT imaging showed that combined treatment of DOX and BC induced a significant reduction in both metabolic activity (29%) and angiogenesis (32%). Both DOX and BC treatments inhibited tumor growth by 20% and 12%, respectively, and combined by 57%, vs. control. We successfully demonstrated that BC increases cytotoxic effects of DOX, resulting in a significant reduction in tumor size. Further studies regarding drug transport and tumor growth biomarkers are necessary to establish the underlying mechanism and potential clinical use of BC in breast cancer patients.

A Selective Reduction of Osteosarcoma by Mitochondrial Apoptosis Using Hydroxyapatite Nanoparticles

Background

In recent years, using hydroxyapatite nanoparticles (HANPs) for tumor therapy attracted increasing attention because HANPs were found to selectively suppress the growth of tumor cells but exhibit ignorable toxicity to normal cells.

Purpose

This study aimed to investigate the capacities of HANPs with different morphologies and particle sizes against two kinds of osteosarcoma (OS) cells, human OS 143B cells and rat OS UMR106 cells.

Methods

Six kinds of HANPs with different morphologies and particle sizes were prepared by wet chemical method. Then, the antitumor effect of these nanoparticles was characterized by means of in vitro cell experiments and in vivo tumor-bearing mice model. The underlying antitumor mechanism involving mitochondrial apoptosis was also investigated by analysis of intracellular calcium, expression of apoptosis-related genes, reactive oxygen species (ROS), and the endocytosis efficiency of the particles in tumor cells.

Results

Both in vitro cell experiments and in vivo mice model evaluation revealed the anti-OS performance of HANPs depended on the concentration, morphology, and particle size of the nanoparticles, as well as the OS cell lines. Among the six HANPs, rod-like HANPs (R-HANPs) showed the best inhibitory activity on 143B cells, while needle-like HANPs (N-HANPs) inhibited the growth of UMR106 cells most efficiently. We further demonstrated that HANPs induced mitochondrial apoptosis by selectively raising intracellular Ca²⁺ and the gene expression levels of mitochondrial apoptosis-related molecules, and depolarizing mitochondrial membrane potential in tumor cells but not in MC3T3-E1, a mouse pre-osteoblast line. Additionally, the anti-OS activity of HANPs also linked with the endocytosis efficiency of the particles in the tumor cells, and their ability to drive oxidative damage and immunogenic cell death (ICD).

Conclusion

The current study provides an effective strategy for OS therapy where the effectiveness was associated with the particle morphology and cell line.

Actein antagonizes colorectal cancer through blocking PI3K/Akt pathways by downregulating IMPDH2

Actein, a triterpene glycoside, isolated from rhizomes of Cimicifuga foetida, was reported to exhibit anticancer effects in vitro and in vivo. However, the effects of actein on colorectal cancer (CRC) remains unclear. As one of the most popular cancers all over the world, CRC ranked third place in both men and women. Recently, we investigated the potential anti-CRC effects of actein and its mechanisms. The Cell counting kit-8 cell proliferation assays, cell cycle detection, apoptosis detection, reactive oxygen species and mitochondrial membrane potential evaluation, western blot, as well as SW480 xenograft mice model were conducted to illustrate the mechanisms of action on anti-CRC effects of actein. Actein could significantly inhibit the human CRC cell lines SW480 and HT-29 proliferation, whereas less antiproliferation effects were found in normal colorectal cell lines HCoEpiC and FHC. Administration of actein resulted in G1 phase cell cycle arrest in both SW480 and HT-29 cells. Moreover, mitochondria-mediated apoptosis was also observed after treatment with actein in SW480 and HT-29 cell lines. Further investigation of mechanisms of action on actein-mediated anti-CRC proliferation effects indicated that the phosphoinositide 3-kinases (PI3K)/Akt pathways were involved. Actein significantly downregulated the phosphorylation of key molecules in PI3K/Akt pathways, including mTOR, glycogen synthesis kinase 3β (GSK-3β), as well as FOXO1. In addition, inosine 5'-monophosphate dehydrogenase type II (IMPDH2) was also observed decreasing in both SW480 and HT-29 cell lines after actein treatment, suggesting that actein may inhibit the PI3K/Akt pathways by decreasing IMPDH2. Finally, our SW480 xenograft model verified the anti-CRC effects and the safety of actein in vivo. Our findings suggest actein is worthy of further investigation as a novel drug candidate for the treatment of CRC.

Actein Inhibits Tumor Growth and Metastasis in HER2-Positive Breast Tumor Bearing Mice via Suppressing AKT/mTOR and Ras/Raf/MAPK Signaling Pathways

HER2-positive breast cancer accounts for 15–20% in breast cancer and 50% of the metastatic HER2-positive breast cancer patients died of central nervous system progression. The present study investigated the effects of actein (a natural cycloartane triterpene) on cells adhesion, migration, proliferation and matrix degradation, and its underlying mechanism in HER2-positive breast cancer cells. The in vivo effect of actein on tumor growth and metastasis in MDA-MB-361 tumor-bearing mice as well as the anti-brain metastasis in tail vein injection mice model were also investigated. Our results showed that actein inhibited HER2-positive breast cancer cells viability, proliferation and migration. Actein also induced MDA-MB-361 cells G1 phase arrest and inhibited the expressions of cyclins and cyclin-dependent kinases. For intracellular mechanisms, actein inhibited the expressions of molecules in AKT/mTOR and Ras/Raf/MAPK signaling pathways. Furthermore, actein (15 mg/kg) was shown to exhibit anti-tumor and anti-metastatic activities in MDA-MB-361 breast tumor-bearing mice, and reduced brain metastasis in tail vein injection mice model. All these findings strongly suggested that actein is a potential anti-metastatic agent for HER2-positive breast cancer.

The Effects of Ludartin on Cell Proliferation, Cell Migration, Cell Cycle Arrest and Apoptosis Are Associated with Upregulation of p21WAF1 in Saos-2 Osteosarcoma Cells In Vitro

BACKGROUND The aim of this study was investigate the effects of the sesquiterpene lactone, ludartin, on cell proliferation, cell migration, apoptosis, and the cell cycle in osteosarcoma cell lines, compared with a normal osteoblast cell line. MATERIAL AND METHODS Osteosarcoma cell lines, MG-63 Saos-2 U-2OS, T1-73 143B, and HOS, and normal hFOB 1.19 osteoblasts, were cultured and treated with increasing doses of ludartin, The MTT colorimetric assay was used to measure cell metabolic activity and viability. Apoptosis was studied by fluorescence-activated cell sorting (FACS) using 4',6-diamidino-2-phenylindole (DAPI) nuclear staining and Annexin-V/propidium iodide (PI) staining. Cell cycle was studied using flow cytometry. Cell migration and invasion were studied using wound healing and Boyden chamber assays. Protein expression was measured by Western blotting. RESULTS Ludartin inhibited cell viability, cell migration, cell proliferation, and increased cell apoptosis, in all osteosarcoma cell lines, with an IC50 dose ranging from 15-30 µM. The greatest effects were on the Saso-2 osteosarcoma cells, with an IC50 of 15 µM. However, ludartin showed minor cytotoxic effects of the normal hFOB 1.19 osteoblasts (IC50 >100 µM). Ludartin exerted its anti-proliferative effects on Saos-2 cells via induction of apoptosis and cell cycle arrest at the G2/M checkpoint, associated with reduced expression of Cdc25c (Ser216), Cdc25c, pCdc2 (Tyr15), and Cdc2 and increased expression of p21WAF1. Ludartin inhibited cell migration and invasion of the Saos-2 cells. CONCLUSIONS The dose-dependent effects of ludartin on cell proliferation, migration, apoptosis, cell cycle arrest at the G2/M checkpoint involved p21WAFI in Saos-2 osteosarcoma cells.

Actein inhibits cell proliferation and migration and promotes cell apoptosis in human non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is the leading cause of death in smokers and the most common cause for cancer mortality in both males and females in the United States. Predisposition of this malignancy to distant metastasis leads to poor prognosis; therefore, it is urgent to discover novel therapeutic agents for metastatic NSCLC. The present study aimed to investigate the effects of actein treatment on NSCLC cell growth and migration. Cell viability assays demonstrated that administration of actein markedly inhibited NSCLC cell proliferation in a dose- and time-dependent manner. Transwell assays demonstrated that actein treatment suppressed cell migration and invasion in two NSCLC cell lines, A549 and 95D. Furthermore, treatment with actein remarkably increased the activities of caspase-3 and -9 in NSCLC cells. The protein expression levels of cytoplasmic BCL2 apoptosis regulator (Bcl-2) and BCL2 associated X (Bax) were markedly decreased, while the protein expression levels of mitochondrial Bax, caspase-3, -9 and cytochrome c were upregulated following actein treatment, as evidenced by western blot analysis. The present results demonstrated that actein inhibited cell proliferation and metastasis and promoted cell apoptosis in NSCLC cells, which indicated that actein administration might serve as a potential therapeutic strategy for the treatment of NSCLC in the clinic.

Leptocarpin Suppresses Proliferation, Migration, and Invasion of Human Osteosarcoma by Targeting Type-1 Insulin-Like Growth Factor Receptor (IGF-1R)

BACKGROUND Leptocarpin (LTC) has drawn much attention for suppressing tumor growth or reducing inflammation. However, the effect of LTC on osteosarcoma has rarely been reported. Our object was to determine whether LTC suppresses MG63 cell proliferation, migration, and invasion, and whether type-1 insulin-like growth factor receptor (IGF-1R) is one of the targets in LTC suppressing osteosarcoma. MATERIAL AND METHODS Cytotoxicity of LTC was performed by use of a cell-counting kit-8 (CCK-8). RNA interference (RNAi) or pEABE-bleo IGF-1R plasmid were used for silencing or overexpressing IGF-1R, Western blot (WB) analysis was used for IGF-1R expression, CCK-8 for proliferation, and transwell assay for migration and invasion. RESULTS LTC (23.533 μM) treatment for 48 h was taken as the 50% inhibiting concentration (IC50), which significantly (P<0.05) suppressed MG63 cells proliferation, migration, and invasion. LTC (IC50) obviously inhibited IGF-1R expression in MG63 cells, with similar effect to small interfering RNA (siRNA), while pEABE-bleo IGF-1R transfection overexpressed IGF-1R. siRNA silencing IGF-1R suppressed MG63 cells proliferation, migration, and invasion, while pEABE-bleo IGF-1R transfection was significantly (P<0.05) promoted. With or without siRNA or pEABE-bleo IGF-1R transfection, LTC (IC50) suppressed MG63 cells proliferation, migration, and invasion. The effect of LTC (IC50) combined with siRNA on suppressing MG63 cells proliferation, migration, and invasion was more obvious, while the effect of LTC (IC50) combined with pEABE-bleo IGF-1R transfection was less significant (P<0.05). CONCLUSIONS LTC suppressed osteosarcoma proliferation, migration, and invasion by inhibiting IGF-1R expression. IGF-1R is one of the targets in LTC suppressing osteosarcoma.

New potential beneficial effects of actein, a triterpene glycoside isolated from Cimicifuga species, in breast cancer treatment

Actein is a triterpene glycoside isolated from the rhizomes of Cimicifuga foetida (Chinese herb “shengma”) which could inhibit the growth of breast cancer cells. Nevertheless, the effect of actein on angiogenesis, which is an essential step for tumor growth and metastasis, has never been reported. Hence, this study aimed to investigate the in vitro and in vivo effects of actein on angiogenesis using human microvascular endothelial cells (HMEC-1), matrigel plug and tumor-bearing mouse models. Our results showed that actein significantly inhibited the proliferation, reduced the migration and motility of endothelial cells, and it could suppress the protein expressions of VEGFR1, pJNK and pERK, suggesting that JNK/ERK pathways were involved. In vivo results showed that oral administration of actein at 10 mg/kg for 7 days inhibited blood vessel formation in the growth factor-containing matrigel plugs. Oral actein treatments (10–15 mg/kg) for 28 days resulted in decreasing mouse 4T1 breast tumor sizes and metastasis to lungs and livers. The apparent reduced angiogenic proteins (CD34 and Factor VIII) expressions and down-regulated metastasis-related VEGFR1 and CXCR4 gene expressions were observed in breast tumors. Our novel findings provide insights into the use of actein for development of anti-angiogenic agents for breast cancer.