sapogenins and Colorectal-Neoplasms

Protopanaxadiol (PPD), a main ginseng metabolite, exerts powerful anticancer effects against multiple types of cancer; however, its cellular targets remain elusive. Here, we synthesized a cell-permeable PPD probe via introducing a bifunctional alkyne-containing diazirine photo-crosslinker and performed a photoaffinity labeling-based chemoproteomic study. We identified retinoblastoma binding protein 4 (RBBP4), a chromatin remodeling factor, as an essential cellular target of PPD in HCT116 colorectal cancer cells. PPD significantly decreased RBBP4-dependent trimethylation at lysine 27 of histone H3 (H3K27me3), a crucial epigenetic marker that correlates with histologic signs of colorectal cancer aggressiveness, and PPD inhibition of proliferation and migration of HCT116 cells was antagonized by RBBP4 RNA silencing. Collectively, our study highlights a previously undisclosed anti-colorectal cancer cellular target of the ginseng metabolite and advances the fundamental understanding of RBBP4 functions via a chemical biology strategy.

Topics: Colorectal Neoplasms; HCT116 Cells; Humans; Panax; Retinoblastoma-Binding Protein 4; Sapogenins; Transcription Factors

Colorectal carcinoma (CRC) recurrence is often accompanied by metastasis. Most metastasis undergo through epithelial-mesenchymal transition (EMT). Studies showed that retinol X receptor alpha (RXRα) and 20(S)-Protopanaxadiol (PPD) have anti-tumour effects. However, the anti-metastasis effect of 20(S)-PPD and the effect of RXRα on EMT-induced metastasis are few studies on. Therefore, the role of RXRα and 20(S)-PPD in CRC cell metastasis remains to be fully elucidated. RXRα with clinicopathological characteristics and EMT-related expression in clinical samples were examined. Then, RXRα and EMT level in SW480 and SW620 cells, overexpressed and silenced RXRα in SW620 cells and SW480 cells, respectively, were evaluated. Finally, 20(S)-PPD effect on SW620 and SW480 cells was evaluated. The results showed that a lower RXRα expression in cancer tissues, and a moderate negative correlation between RXRα and N stage, and tended to higher level of EMT. SW480 and SW620 cells had the highest and lowest RXRα expression among four CRC cell lines. SW480 had lower EMT level than SW620. Furthermore, 20(S)-PPD increased RXRα and inhibited EMT level in SW620 cell. Finally, 20(S)-PPD cannot restore SW480 cells EMT level to normal when RXRα silencing. These findings suggest that 20(S)-PPD may inhibit EMT process in CRC cells by regulating RXRα expression.

Topics: Adult; Aged; Animals; Cell Line, Tumor; Cell Movement; Cell Proliferation; Colorectal Neoplasms; Disease Models, Animal; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Male; Middle Aged; Retinoid X Receptor alpha; Sapogenins

Among important components of American ginseng, protopanaxadiol (PPD) showed more active anticancer potential than other triterpenoid saponins. In this study, we determined the in vivo effects of PPD in a mouse cancer model first. Then, using human colorectal cancer cell lines, we observed significant cancer cell growth inhibition by promoting G1 cell cycle redistribution and apoptosis. Subsequently, we characterized the downstream genes targeted by PPD in HCT-116 cancer cells. Using Affymetrix high density GeneChips, we obtained the gene expression profile of the cells. Microarray data indicated that the expression levels of 76 genes were changed over two-fold after PPD, of which 52 were upregulated while the remaining 24 were downregulated. Ingenuity pathway analysis of top functions affected was carried out. Data suggested that by regulating the interactions between p53 and DR4/DR5, the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) pathway played a key role in the action of PPD, a promising colon cancer inhibitory compound.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Female; Gene Expression Profiling; Humans; Mice; Panax; Sapogenins; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand; Xenograft Model Antitumor Assays

Natural products play an important role in cancer therapeutics, and lately more attentions have been paid to the prevention of major lethal malignancies, such as colorectal cancer (CRC). After oral ingestion, botanicals' parent compounds can be converted to their metabolites by the enteric microbiome, and these metabolites may have different bioactivities and variable bioavailability. In this study, we used an active ginseng metabolite, protopanaxadiol (PPD), as an example to assess its colon cancer preventive effect by comparing its effect with the treatment effect of fluorouracil (5-FU). A xenograft tumor nude mouse model with human colon cancer cell inoculation was used. After preventive PPD or treatment 5-FU administration with the same dose (30 mg/kg), tumor growth inhibition was evaluated by both a Xenogen bioluminescence imaging technique and manual tumor size measurement. Our data showed that preventive PPD very significantly inhibited the tumor growth compared to 5-FU (p < 0.01). Our data suggest that the PPD is a promising cancer prevention agent. More studies are needed to explore the chemopreventive actions of PPD and its potential clinical utility.

Topics: Animals; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Biological Availability; Biological Products; Colorectal Neoplasms; Disease Models, Animal; Fluorouracil; Heterografts; Humans; Mice, Nude; Neoplasm Transplantation; Panax; Phytotherapy; Sapogenins

Protopanaxadiol (PPD) is a triterpenoid that can be prepared from steamed ginseng. PPD possesses anticancer potential via caspase-dependent apoptosis. Whether paraptosis, a type of the caspase-independent cell death, is also induced by PPD has not been evaluated.. Cell death, the cell cycle and intracellular reactive oxygen species (ROS) were analyzed by flow cytometry after staining with annexin V/PI, PI/RNase or H2DCFDA. We observed morphological changes by crystal violet staining assay. Mitochondrial swelling was measured by ultraviolet-visible spectrophotometry. The activation of NF-κB was measured by luciferase reporter assay.. At comparable concentrations of 5-fluorouracil, PPD induced more cell death in human colorectal cancer cell lines HCT-116 and SW-480. We demonstrated that PPD induced paraptosis in these cancer cells. PPD treatment significantly increased the percentage of cancer cells with cytoplasmic vacuoles. After the cells were treated with PPD and cycloheximides, cytoplasmic vacuole generation was inhibited. The paraptotic induction effect of PPD was also supported by the results of the mitochondrial swelling assay. PPD induced ROS production in cancer cells, which activated the NF-κB pathway. Blockage of ROS by NAC or PS-1145 inhibited the activation of NF-κB signaling.. PPD induces colorectal cancer cell death in part by induction of paraptosis. The anticancer activity of PPD may be enhanced by antioxidants such as green tea, which also inhibit the activation of NF-κB signaling.

Topics: Anticarcinogenic Agents; Antineoplastic Agents, Phytogenic; Cell Death; Chemoprevention; Colorectal Neoplasms; HCT116 Cells; Heterocyclic Compounds, 3-Ring; Humans; Mitochondria; NF-kappa B; Panax; Phytotherapy; Plant Extracts; Pyridines; Reactive Oxygen Species; Sapogenins; Signal Transduction; Vacuoles

Protopanaxadiol (PPD), an aglycon of ginseng saponins, has shown anticancer activity in earlier studies. Here, we have reported the semisynthesis of nine PPD derivatives with acetyl substitutions. Subsequently, the antiproliferative effects of these nine analogs on different human cancer cell lines have been investigated. Compounds 1, 3, and 5 showed more significant and more potent antiproliferative activity compared with PPD and other derivatives. A flow cytometric assay indicated that compounds 1, 3, and 5 arrested cell cycle progression in the G1 phase and significantly induced apoptosis of cancer cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Breast Neoplasms; Cell Growth Processes; Cell Line, Tumor; Colorectal Neoplasms; Drug Screening Assays, Antitumor; Female; G1 Phase; HCT116 Cells; Humans; Magnetic Resonance Spectroscopy; Panax; Sapogenins; Saponins; Structure-Activity Relationship

A new cephalostatin/ritterazine analogue was prepared from the commercially available hecogenin acetate and the natural cytotoxic steroid 22-epi-hippuristanol. The method involved the reductive dimerization of enaminoketones (condensation of alpha-aminoketones) and condensation between an enaminoketone and an alpha-hydroxyketone. The new analogue showed higher cytotoxic activity than the cytotoxic 22-epi-hippuristanol against MDA-MB-231, A-549 and HT-29 cultured tumor cell lines.

Topics: Antineoplastic Agents; Breast Neoplasms; Carcinoma; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Cytotoxins; Female; Humans; Inhibitory Concentration 50; Lung Neoplasms; Phenazines; Sapogenins; Spiro Compounds; Steroids; Sterols

Colorectal cancer remains one of the most prevalent cancer and a leading cause of cancer related death in the US. Many currently used chemotherapeutic agents are derived from botanicals. Identifying herbal sources, including those from ginseng family, to develop better anti-cancer therapies remains an essential step in advancing the treatment of the cancer. In this article, potential roles of ginseng herbs, especially American ginseng and notoginseng, in colorectal cancer therapeutics are presented. The major pharmacologically active constituents of ginsengs are ginsenosides, which can be mainly classified as protopanaxadiol and protopanaxatriol groups. Structure-activity relationship between their chemical structures and pharmacological activities are discussed. In addition, various steaming temperature and time treatment of the ginseng herbs can change ginsenoside profiles, and enhance their anti-cancer activities. This heat treatment process may increase the role of ginseng in treating colorectal cancer.

Topics: Colorectal Neoplasms; Drugs, Chinese Herbal; Herbal Medicine; Humans; Panax; Sapogenins; Structure-Activity Relationship