SB365, Pulsatilla saponin D, targets c-Met and exerts antiangiogenic and antitumor activities

Antiangiogenic, Anti-Inflammatory and Antioxidant Properties of Bidens tripartite Herb, Galium verum Herb and Rumex hydrolapathum Root

Plants are commonly used in folk medicine. Research indicates that the mechanisms of biological activity of plant extracts may be essential in the treatment of various diseases. In this respect, we decided to test the ethanolic extracts of Bidens tripartita herb (BTH), Galium verum herb (GVH), and Rumicis hydrolapathum root (RHR) on angiogenic, anti-inflammatory, and antioxidant properties and their total polyphenols content. In vitro studies using endothelial cells were used to see tested extracts' angiogenic/angiostatic and anti-inflammatory properties. The DPPH assay and FRAP analysis were used to detect antioxidant properties of extracts. The Folin-Ciocalteu analysis was used to determine the content of total polyphenols. The results of gas chromatography-mass spectrometry analysis was also presented. In vitro study demonstrated that BTH, GVH, and RHR ethanolic extracts significantly increased cell invasiveness, compared with the control group. Increased endothelial proangiogenic invasiveness was accompanied by reduced metalloproteinase inhibitor 1 (TIMP-1) and raised in metalloproteinase 9 (MMP-9). Only BTH and GVH significantly reduced cell proliferation, while BTH and RHR facilitated migration. Additionally, tested extracts reduced the production of proangiogenic platelet-derived growth factor (PDGF) and hepatocyte growth factor (HGF). The most potent anti-inflammatory capacity showed BTH and GVH, reducing proinflammatory interleukin 8 (CXCL8) and interleukin 6 (Il-6), compared to RHR extract that has slightly less inhibited CXCL8 production without affecting IL-6 production. Moreover, we confirmed the antioxidant properties of all examined extracts. The highest activity was characterized by RHR, which has been correlated with the high content of polyphenols. In conclusion, the modifying influence of examined extracts can be promising in disorders with pathogenesis related to angiogenesis, inflammation and free radicals formation. BTH is the best choice among the three tested extracts with its antiangiogenic and anti-inflammatory properties.

Inhibiting Angiogenesis by Anti-Cancer Saponins: From Phytochemistry to Cellular Signaling Pathways

Saponins are one of the broadest classes of high-molecular-weight natural compounds, consisting mainly of a non-polar moiety with 27 to 30 carbons and a polar moiety containing sugars attached to the sapogenin structure. Saponins are found in more than 100 plant families as well as found in marine organisms. Saponins have several therapeutic effects, including their administration in the treatment of various cancers. These compounds also reveal noteworthy anti-angiogenesis effects as one of the critical strategies for inhibiting cancer growth and metastasis. In this study, a comprehensive review is performed on electronic databases, including PubMed, Scopus, ScienceDirect, and ProQuest. Accordingly, the structural characteristics of triterpenoid/steroid saponins and their anti-cancer effects were highlighted, focusing on their anti-angiogenic effects and related mechanisms. Consequently, the anti-angiogenic effects of saponins, inhibiting the expression of genes related to vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1-α (HIF-1α) are two main anti-angiogenic mechanisms of triterpenoid and steroidal saponins. The inhibition of inflammatory signaling pathways that stimulate angiogenesis, such as pro-inflammatory cytokines, mitogen-activated protein kinase (MAPKs), and phosphoinositide 3-kinases/protein kinase B (PI3K/Akt), are other anti-angiogenic mechanisms of saponins. Furthermore, the anti-angiogenic and anti-cancer activity of saponins was closely related to the binding site of the sugar moiety, the type and number of their monosaccharide units, as well as the presence of some functional groups in their aglycone structure. Therefore, saponins are suitable candidates for cancer treatment by inhibiting angiogenesis, for which extensive pre-clinical and comprehensive clinical trial studies are recommended.

Pulsatilla vulgaris Inhibits Cancer Proliferation in Signaling Pathways of 12 Reporter Genes

This study aimed to examine if methanolic extracts of Pulsatilla vulgaris Mill. can inhibit HeLa cell proliferation through the modulation of cancer-related signaling pathways. The cytotoxicity and chemical composition of P. vulgaris leaves and root extracts were also determined. Research showed that root extract of P. vulgaris inhibited 12 signaling pathways in a cervical cancer cell line and the most potent activation inhibition was observed for MYC, Notch, Wnt, E2F, Ets, Stat3, Smad, Hdghog, AP-1, and NF-κB, at a concentration of 40 µg/mL. The methanolic extracts of P. vulgaris enhanced apoptotic death and deregulated cellular proliferation, differentiation, and progression toward the neoplastic phenotype by altering key signaling molecules required for cell cycle progression. This is the first study to report the influence of P. vulgaris on cancer signaling pathways. Additionally, our detailed phytochemical analysis of the methanolic extracts of P. vulgaris gives a conclusion that compounds, which strongly suppressed the growth and proliferation of HeLa cancer cells were mainly triterpenoid saponins accompanied by phenolic acids.

Pulsatilla chinensis (Bge.) Regel: A Systematic Review on Anticancer of Its Pharmacological Properties, Clinical Researches and Pharmacokinetic Studies

Pulsatilla chinensis (Bge.) Regel (PC) is one of the most commonly used Chinese medicines and has a history of thousands of years. This article reviews the research results of anti-cancer activity and its mechanism of action obtained from experimental, clinical, pharmacokinetic and bioinformatic studies in recent years. A large number of studies have shown that PC exerts had anti-cancer effects on different types of tumor cells by inhibiting cell proliferation, inducing apoptosis, inhibiting cell cycle and energy metabolism, inducing autophagy, and inhibiting angiogenesis. The literature has shown that PC can trigger the expression of autophagy-related molecules, activate the mitochondrial apoptotic pathway, inhibit the phosphorylation of PI3K downstream factors, down-regulate the expression of glycolysis-related proteins, and regulate a series of cancer-related signal pathways and proteins. The molecular mechanisms involved in PC include signal pathways such as Notch, PI3K/AKT/m TOR, AKT/mTOR, and MEK/ERK. The article also discusses the derivatives of the active ingredients in PC, which greatly improved the anti-cancer effect. In conclusion, this review provides a comprehensive overview of the biological effects and mechanisms of PC against cancer. The analysis of the literature shows that PC can be used as a potential drug candidate for the treatment of cancer.

Pharmacological activities and molecular mechanisms of Pulsatilla saponins

Saponins are found in a variety of higher plants and display a wide range of pharmacological activities, including expectorant, anti-inflammatory, vasoprotective and antimicrobial properties. Pulsatilla chinensis (P. chinensis, Bai Tou Weng, ) has been used medically in China for thousands of years for the treatment of diseases caused by bacteria, and it is rich in triterpenoid saponins. In recent decades, anemoside B4 (Pulchinenoside C) is well studied since it has been used as a quality control marker for P. chinensis. At the same time, more and more other active compounds were found in the genus of Pulsatilla. In this review, we summarize the pharmacological activities of Pulsatilla saponins (PS) and discuss the cellular or molecular mechanisms that mediate their multiple activities, such as inducing cancer cell apoptosis, inhibiting tumor angiogenesis, and protecting organs via anti-inflammatory and antioxidant measures. We aim to provide comprehensive analysis and summary of research progress and future prospects in this field to facilitate further study and drug discovery of PS.

Human telomerase reverse transcriptase promotes the epithelial to mesenchymal transition in lung cancer cells by enhancing c-MET upregulation

Human telomerase reverse transcriptase (hTERT), the essential catalytic subunit of telomerase, is associated with telomere homeostasis to prevent replicative senescence and cellular aging. However, hTERT reactivation also has been linked to the acquisition of several hallmarks of cancer, although the underlying mechanism beyond telomere extension remains elusive. This study demonstrated that hTERT overexpression promotes, whereas its inhibition by shRNA suppresses, epithelial-mesenchymal transition (EMT) in lung cancer cells (A549 and H1299). We found that hTERT modulates the expression of EMT markers E-cadherin, vimentin, and cytokeratin-18a through upregulation of the c-MET. Ectopic expression of hTERT induces expression of c-MET, while hTERT-shRNA treatment significantly decreases the c-MET level in A549 and H1299 through differential expression of p53 and c-Myc. Reporter assay suggests the regulation of c-MET expression by hTERT to be at the promoter level. An increase in c-MET level significantly promotes the expression of mesenchymal markers, including vimentin and N-cadherin, while a notable increase in epithelial markers E-cadherin and cytokeratin-18a is observed after the c-MET knockdown in A549.

Extracts from Pulsatilla patens target cancer-related signaling pathways in HeLa cells

The purpose of this study was to determine if a methanolic extract of the Pulsatilla patens (L.) Mill. can inhibit the progression of cancer through the modulation of cancer-related metabolic signaling pathways. We analyzed a panel of 13 inducible luciferase reporter gene vectors which expression is driven by enhancer elements that bind to specific transcription factors for the evaluation of the activity of cancer signaling pathways. The root extract of P. patens exhibited strong inhibition of several signaling pathways in HeLa cells, a cervical cancer cell line, and was found to be the most potent in inhibiting the activation of Stat3, Smad, AP-1, NF-κB, MYC, Ets, Wnt and Hdghog, at a concentration of 40 µg/mL. The methanolic extracts of P. patens enhanced apoptotic death, deregulated cellular proliferation, differentiation, and progression towards the neoplastic phenotype by altering key signaling molecules required for cell cycle progression. This is the first study to report the influence of Pulsatilla species on cancer signaling pathways. Further, our detailed phytochemical analysis of the methanolic extracts of the P. patens allowed to deduce that compounds, which strongly suppressed the growth and proliferation of HeLa cancer cells were mainly triterpenoid saponins accompanied by phenolic acids.

Synergistic anti-breast cancer effect of pulsatilla saponin D and camptothecin through interrupting autophagic-lysosomal function and promoting p62-mediated ubiquitinated protein aggregation

Autophagy is an evolutionarily conserved mechanism to protect the cells from unfavorable environmental conditions. Inhibition of autophagy has been contemplated as a novel strategy to enhance anticancer efficacy of existing chemotherapeutic agents. We previously reported that pulsatilla saponin D (PSD) was a potent autophagy inhibitor. However, its anticancer potential as adjuvant and underlying mechanisms are still unknown. In this study, we identified that PSD induced the formation of autophagosome in MCF-7 and MDA-MB-231 breast cancer cells. However, PSD alone and particularly co-treatment with camptothecin remarkably increased p62 protein levels, indicating that PSD strongly inhibited the autophagic cargo degradation. The mechanistic study indicated that PSD profoundly abolished the co-localization of EGFP-LC3 and lysosomal-specific probe LysoTracker Red, suggesting that the autophagosome-lysosome fusion was blocked by PSD, which is similar to the action of chloroquine. In addition, PSD significantly increased lysosomal pH and inhibited the activation of lysosomal cathepsins in both breast cancer cell lines. Furthermore, the accrued p62 resulted in accumulation of ubiquitinated proteins owing to the interaction with p62 and delivery to the malfunctioned autophagosome by PSD. Finally, we demonstrated that PSD synergistically enhanced the anticancer activity of camptothecin (CPT) in cultured breast cancer cells and in mouse xenograft tumor models. Our results indicated that PSD inhibited autophagic flux via blocking autophagosome-lysosome fusion and lysosomal acidification, which may confer a synergistic anti-breast cancer activity of PSD and CPT.

SB365 induces apoptosis and suppresses proliferation of glioblastoma cells

CONTEXT:

Glioblastoma is a malignant brain tumor with limited treatment modalities due to its nature. SB365, Pulsatilla saponin D, is known to induce apoptosis and inhibit the growth of many cancer cells.

AIM:

We elucidated the anticancer effects of SB365 in glioblastoma cells.

METHODS:

We examined the antiproliferative activity of SB365 in human glioblastoma cell lines. Apoptosis was evaluated using the Hoechst assay, TUNEL assay, DAPI nuclear staining, and Western blotting analysis. To test the antimetastatic capacity of SB365, cell migration assay was conducted, and hypoxia-inducible factor-1 alpha (HIF-1α) expression and vascular endothelial growth factor (VEGF) level were determined under hypoxic conditions.

STATICAL ANALYSIS:

Significance of the results was confirmed by a one-way analysis of variance analysis.

RESULTS:

SB365 treatment suppressed the growth of glioblastoma cells and resulted in apoptotic morphological features such as nuclear condensation and fragmentation, enhancing the expression of cleaved poly (ADP-ribose) polymerase and caspase-3. It also significantly delayed cell migration and decreased the HIF-1α expression and VEGF secretion.

CONCLUSION:

Our findings thus demonstrate that SB365 induced apoptosis and delayed the growth and migration of human glioblastoma cells. It is considered that SB365 would be a promising therapeutic option for glioblastoma.

Computational and in vitro characterization of ICY-5: A potential candidate promoting mitochondrial apoptosis via the c-MET and STAT3 pathways

Targeted chemotherapy remains the primary choice in controlling various forms of breast cancer (BC) due to its heterogenous gene expressions in various subtypes. In silico and in vitro evaluation of ICY-5, a novel arylidene analogue against c-MET, was performed. ICY-5 exhibited a docking score of -9.6 kcal/mol in inactive conformation and, - 8.6 kcal/mol in active conformation for c-MET. ICY-5 inhibited c-MET enzyme with an IC₅₀ of 34.34 nM. The compound effectively inhibited MDA-MB 231 and MCF-7 cell proliferation, with GI₅₀ values of 62.61 and 75.31 nM, respectively, and hepatocyte growth factor (HGF)/R c-MET phosphorylation with IC₅₀ s of 71.41 and 83.77 nM, respectively. ICY-5 dose-dependently inhibited HGF-induced transmigration, cell scattering, invasion and altered cell cycle. An increase in apoptotic populations of these cells, with a dose-dependent decease in phosphorylation of STAT3 protein was observed. Furthermore, ICY-5 upregulated the caspase-3, caspase-9, Bcl-2-associated X and survivin, and downregulated Bcl-2, vascular endothelial growth factor, matrix metalloproteinase-2 (MMP-2), and MMP-9 in both BC cell lines. In summary, ICY-5 exhibited excellent efficacy in BC cells, targeting c-MET/SAT-3-mediated mitochondrial apoptosis. Further research will be required to ascertain ICY-5 suitability as a targeted chemotherapeutic against multiple forms of BC.

7-Methoxy-1-Tetralone Induces Apoptosis, Suppresses Cell Proliferation and Migration in Hepatocellular Carcinoma via Regulating c-Met, p-AKT, NF-κB, MMP2, and MMP9 Expression

This study aimed to determine the anti-proliferative and anti-migratory effects of 7-methoxy-1-tetralone (MT) in hepatocellular carcinoma (HCC) cells. MTT assay assessed HCC cell viability; cell apoptosis of HCC cells was determined by flow cytometry; wound healing assay evaluated HCC cell migratory ability; protein expression levels were assessed using western blot assay; the in vivo antitumor effects of MT were tested in BALB/c nude mice and the pathological changes within the tumor tissues were evaluated by immunohistochemistry. MT treatment significantly suppressed the cell proliferative and migratory potentials of HepG2 cells, and induced HepG2 cell apoptosis. The western blot assay showed that MT treatment caused a suppression on c-Met, phosphorylated AKT (p-AKT), NF-κB, matrix metallopeptidase 2 (MMP2)/MMP9 protein levels in HepG2 cells. Further in vivo animal studies deciphered that MT treatment suppressed tumor growth of HepG2 cells in the nude mice, but had no effect on the body weight and the organ index of liver and spleen. Further immunohistochemistry analysis of the dissected tumor tissues showed that MT treatment significantly suppressed the protein expression levels of NF-κB, MMP9, MMP2, and p-AKT. In summary, the present study demonstrated the anti-tumor effects of MT on the HCC, and MT suppressed HCC progression possibly via regulating proliferation- and migration-related mediators including c-Met, p-AKT, NF-κB, MMP2, and MMP9 in HepG2 cells.

SB365, Pulsatilla Saponin D Induces Caspase-Independent Cell Death and Augments the Anticancer Effect of Temozolomide in Glioblastoma Multiforme Cells

SB365, a saponin D extracted from the roots of Pulsatilla koreana, has been reported to show cytotoxicity in several cancer cell lines. We investigated the effects of SB365 on U87-MG and T98G glioblastoma multiforme (GBM) cells, and its efficacy in combination with temozolomide for treating GBM. SB365 exerted a cytotoxic effect on GBM cells not by inducing apoptosis, as in other cancer cell lines, but by triggering caspase-independent cell death. Inhibition of autophagic flux and neutralization of the lysosomal pH occurred rapidly after application of SB365, followed by deterioration of mitochondrial membrane potential. A cathepsin B inhibitor and N-acetyl cysteine, an antioxidant, partially recovered cell death induced by SB365. SB365 in combination with temozolomide exerted an additive cytotoxic effect in vitro and in vivo. In conclusion, SB365 inhibits autophagic flux and induces caspase-independent cell death in GBM cells in a manner involving cathepsin B and mainly reactive oxygen species, and its use in combination with temozolomide shows promise for the treatment of GBM.

Antitumor effects of SB injection in canine osteosarcoma and melanoma cell lines

The present study was designed to evaluate the effect of SB injection, which is composed of extracts from the roots of Pulsatilla koreana, Panax ginseng, and Glycyrrhiza glabra, on the viability of canine osteosarcoma and melanoma cells and nonneoplastic canine cells. Cells were treated with SB injection, conventional chemotherapeutic drugs, or a combination of both at various concentrations. Cellular viability was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry was used to evaluate the cell cycle and apoptosis. SB injection inhibited the growth of osteosarcoma and melanoma cells in a dose-dependent manner. The cell cycle of the affected cells was arrested in the G2/M phase, indicating an anti-proliferative effect. SB injection dose-dependently increased the rate of apoptosis. Furthermore, we found that combining SB injection with chemotherapeutic drugs resulted in a greater reduction in canine malignant cell proliferation than either treatment alone. SB injection did not affect the viability of peripheral blood mononuclear cells regardless of concentration, which suggested that SB injection did not suppress the activity of normal cells. This study suggested that SB injection can be considered an effective alternative medication for animal cancers in veterinary medicine.

Anticancer activities and mechanisms of heat-clearing and detoxicating traditional Chinese herbal medicine

In traditional Chinese medicine (TCM) theory, pathogenic heat and toxins, which are akin to the inflammatory factors, are the causes of cancer and could promote its virulent development. Therefore, heat-clearing and detoxicating (HCD) herbs are essential components of TCM formulas for cancer treatment. An increasing interest has been focused on the study of HCD herbs and accumulated evidences have shown that HCD herbs or HCD herbs-based formulas exhibited remarkable anticancer effects when used alone or combined with other therapeutic approaches. Some of the HCD herb-derived products have been tested in clinical trials. Studies revealed that extracts or pure compounds of the HCD herbs showed a broad anticancer spectrum against both solid and hematologic malignancies without significant toxic effects. Notably, some HCD herbs or formulas could strongly enhance the anticancer activities of chemo- or radio-therapy and alleviate their side effects. The anticancer activities of HCD herb exacts or the pure compounds were reported to be through multiple cellular or molecular mechanisms, such as induction of cancer cell apoptosis, differentiation and cell cycle arrest, inhibition of cancer cell growth, invasion and metastasis, and inhibition of tumor angiogenesis. In this review, we provide comprehensive analysis and summary of research progress and future prospects in this field to facilitate the further study and application of HCD herbs.

Anticancer Chemodiversity of Ranunculaceae Medicinal Plants: Molecular Mechanisms and Functions

The buttercup family, Ranunculaceae, comprising more than 2,200 species in at least 62 genera, mostly herbs, has long been used in folk medicine and worldwide ethnomedicine since the beginning of human civilization. Various medicinal phytometabolites have been found in Ranunculaceae plants, many of which, such as alkaloids, terpenoids, saponins, and polysaccharides, have shown anti-cancer activities in vitro and in vivo. Most concerns have been raised for two epiphany molecules, the monoterpene thymoquinone and the isoquinoline alkaloid berberine. At least 17 genera have been enriched with anti-cancer phytometabolites. Some Ranunculaceae phytometabolites induce the cell cycle arrest and apoptosis of cancer cells or enhance immune activities, while others inhibit the proliferation, invasion, angiogenesis, and metastasis, or reverse the multi-drug resistance of cancer cells thereby regulating all known hallmarks of cancer. These phytometabolites could exert their anti-cancer activities via multiple signaling pathways. In addition, absorption, distribution, metabolism, and excretion/toxicity properties and structure/activity relationships of some phytometabolites have been revealed assisting in the early drug discovery and development pipelines. However, a comprehensive review of the molecular mechanisms and functions of Ranunculaceae anti-cancer phytometabolites is lacking. Here, we summarize the recent progress of the anti-cancer chemo- and pharmacological diversity of Ranunculaceae medicinal plants, focusing on the emerging molecular machineries and functions of anti-cancer phytometabolites. Gene expression profiling and relevant omics platforms (e.g. genomics, transcriptomics, proteomics, and metabolomics) could reveal differential effects of phytometabolites on the phenotypically heterogeneous cancer cells.

Curcumin inhibited HGF-induced EMT and angiogenesis through regulating c-Met dependent PI3K/Akt/mTOR signaling pathways in lung cancer

The epithelial-mesenchymal transition (EMT) and angiogenesis have emerged as two pivotal events in cancer progression. Curcumin has been extensively studied in preclinical models and clinical trials of cancer prevention due to its favorable toxicity profile. However, the possible involvement of curcumin in the EMT and angiogenesis in lung cancer remains unclear. This study found that curcumin inhibited hepatocyte growth factor (HGF)-induced migration and EMT-related morphological changes in A549 and PC-9 cells. Moreover, pretreatment with curcumin blocked HGF-induced c-Met phosphorylation and downstream activation of Akt, mTOR, and S6. These effects mimicked that of c-Met inhibitor SU11274 or PI3 kinase inhibitor LY294002 or mTOR inhibitor rapamycin treatment. c-Met gene overexpression analysis further demonstrated that curcumin suppressed lung cancer cell EMT by inhibiting c-Met/Akt/mTOR signaling pathways. In human umbilical vein endothelial cells (HUVECs), we found that curcumin also significantly inhibited PI3K/Akt/mTOR signaling and induced apoptosis and reduced migration and tube formation of HGF-treated HUVEC. Finally, in the experimental mouse model, we showed that curcumin inhibited HGF-stimulated tumor growth and induced an increase in E-cadherin expression and a decrease in vimentin, CD34, and vascular endothelial growth factor (VEGF) expression. Collectively, these findings indicated that curcumin could inhibit HGF-promoted EMT and angiogenesis by targeting c-Met and blocking PI3K/Akt/mTOR pathways.

Chemoprevention of Low-Molecular-Weight Citrus Pectin (LCP) in Gastrointestinal Cancer Cells

Background & Aims: Low-molecular-weight citrus pectin (LCP) is a complex polysaccharide that displays abundant galactosyl (i.e., sugar carbohydrate) residues. In this study, we evaluated the anti-tumor properties of LCP that lead to Bcl-xL -mediated dampening of apoptosis in gastrointestinal cancer cells.

Methods: We used AGS gastric cancer and SW-480 colorectal cancer cells to elucidate the effects of LCP on cell viability, cell cycle and apoptosis in cultured cells and tumor xenografts.

Results: Significantly decreased cell viabilities were observed in LCP treated AGS and SW-480 cells (P<0.05). Cell cycle-related protein expression, such as Cyclin B1, was also decreased in LCP treated groups as compared to the untreated group. The AGS or SW-480 cell-line tumor xenografts were significantly smaller in the LCP treated group as compared the untreated group (P<0.05). LCP treatment decreased Galectin-3 (GAL-3) expression levels, which is an important gene in cancer metastasis that results in reversion of the epithelial-mesenchymal transition (EMT), and increased suppression of Bcl-xL and Survivin to promote apoptosis. Moreover, results demonstrated synergistic tumor suppressor activity of LCP and 5-FU against gastrointestinal cancer cells both in vivo and in vitro.

Conclusions: LCP effectively inhibits the growth and metastasis of gastrointestinal cancer cells, and does so in part by down-regulating Bcl-xL and Cyclin B to promote apoptosis, and suppress EMT. Thus, LCP alone or in combination with other treatments has a high potential as a novel therapeutic strategy to improve the clinical therapy of gastrointestinal cancer.

LRG1 modulates epithelial-mesenchymal transition and angiogenesis in colorectal cancer via HIF-1α activation

Background

Leucine-rich-alpha-2-glycoprotein 1 (LRG1) has been reported to be involved in several tumors, whether it participates in colorectal cancer (CRC) progression remains unclear. Here, we investigated the biological function and underlying molecular mechanisms of LRG1 in CRC.

Methods

The mRNA and protein levels of LRG1 were assessed in CRC tissues through RT-PCR and immunohistochemistry, respectively. HCT116 and SW480 cells were treated with LRG1 siRNA, control siRNA, or recombinant LRG1. Transwell invasion assays and wound healing assays were performed to evaluate the invasion and migration of CRC cells. Epithelial-to-mesenchymal transition (EMT) markers of E-cadherin, VDR, N-cadherin, α-SMA, Vimentin and Twist1 were detected by RT-PCR and western blot. Enzyme-linked immunosorbent assay was used to measure the secretion level of VEGF-A. Conditioned medium from CRC cells was collected for endothelial cell migration, tube formation and aortic ring sprouting assays.

Results

LRG1 was overexpressed in CRC tissues and associated with cancer aggressiveness. LRG1 was further found to induce the EMT process, as well as CRC cell migration and invasion capacity. In addition, LRG1 promoted VEGF-A expression in CRC cells and contributed to tumor angiogenesis. Furthermore, HIF-1α could be induced by LRG1 in a concentration- and time-dependent manner, which was responsible for LRG1-induced VEGF-A expression and EMT.

Conclusions

The present study suggests that LRG1 plays a crucial role in the progression of CRC by regulating HIF-1α expression, thereby may be a promising therapeutic target of CRC.

Crizotinib exhibits antitumor activity by targeting ALK signaling not c-MET in pancreatic cancer

Crizotinib, a c-MET/ALK inhibitor, has exhibited antitumor efficacy in different types of cancers. However, studies regarding Crizotinib in pancreatic cancer have been limited. Thus, we investigated the effect of Crizotinib on pancreatic cancer and its mechanism of action. Crizotinib strongly suppressed the growth and proliferation of pancreatic cancer cells in a dose-dependent manner. Also, it induced apoptosis by modulating its related factors. In the study, with regard to the mechanism of action, Crizotinib did not inhibit c-MET expression on pancreatic cancer cells; instead, it specifically inhibited the activity of ALK, which was identified to be highly expressed on various pancreatic cancer cells and tissues in our study. In 42 different receptor tyrosine kinase (RTKs) array, Crizotinib also strongly inhibited the expression of activated ALK in pancreatic cancer cells, modulating its downstream mediators such as STAT3, AKT, and ERK. Furthermore, Crizotinib inhibited angiogenesis in a mouse Matrigel plug assay as well as the progression of tumor growth in a mouse xenograft model. Taken together, our investigation shows that Crizotinib inhibits the ALK signaling pathway in pancreatic cancer, resulting in cell growth/angiogenesis inhibition and apoptosis induction. We suggest that Crizotinib might be used as a novel therapeutic drug for treating pancreatic cancer.

Widdrol, a sesquiterpene isolated from Juniperus chinensis, inhibits angiogenesis by targeting vascular endothelial growth factor receptor 2 signaling

Widdrol is an odorous compound derived from Juniperus chinensis that is widely used in traditional medicine to treat fever, inflammation and cancer. It was previously reported that widdrol has antitumor activity by apoptosis induction in cancer cells in vitro. However, its anti-angiogenic activity remains elusive. In the present study, we investigated the anti‑angiogenic activity of widdrol and the molecular mechanisms involved. Widdrol inhibited cell proliferation via G1 phase arrest induction in human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner. Additionally, it was associated with a decreased expression of cyclin-dependent kinase 2 (CDK2) and an increased expression of p21, a CDK inhibitor. Widdrol significantly inhibited the cell migration and tube formation of HUVECs using an in vitro angiogenesis assay. The results showed that widdrol suppressed phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2) and its downstream proteins, such as AKT, focal adhesion kinase (FAK) and endothelial nitric oxide synthase (eNOS). Moreover, widdrol effectively reduced tumor growth and blood vessel formation in colon tumor xenograft mice. Collectively, these results suggested that widdrol may act as a potential anti-angiogenic agent by inhibiting vessel sprouting and growth, which may have implications for angioprevention.

Role of c-mesenchymal-epithelial transition pathway in gastric cancer

INTRODUCTION

Gastric cancer is the fourth most common cancer burden worldwide; many patients show incurable disease at the time of diagnosis and prognosis remains unfavorable. Recently, new findings on gastric cancer biology led to the preclinical and clinical development of new compounds aiming to improve the overall survival and to preserve quality of life and reducing chemotherapy-related toxicities. Patients with human epidermal growth factor receptor 2 (HER2) overexpression/amplification have experienced benefit from the integration of trastuzumab to the standard chemotherapy. Ramucirumab has been recently approved in second line for treatment of gastric cancer.

AREAS COVERED

Drugs targeting molecules such as anti c-mesenchymal-epithelial transition (MET), mammalian target of rapamycin inhibitors, polo-like kinase 1 inhibitors are under investigation or in preclinical or early clinical development. Approximately 10 - 20% of gastric cancer presented an increased MET gene copy numbers; inappropriate activation of MET promotes cellular proliferation, cell motility, invasiveness and angiogenesis and is associated with more aggressive phenotype and with a lower survival.

EXPERT OPINION

The role of c-MET has been extensively evaluated both in Asian and Western population, even if data are far from being conclusive. The activation of MET/hepatocyte growth factor pathway is a negative prognostic factor, and it could partially explain the resistance to EGFR/HER2 inhibitors acting as a rescue pathway likewise in other tumors.

SB365, Pulsatilla saponin D, suppresses the growth of gefitinib-resistant NSCLC cells with Met amplification

Clinical treatment using epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) such as gefitinib or erlotinib has been applied in patients with non-small cell lung cancers (NSCLCs). Unfortunately, acquired drug resistance emerges in these patients due to the amplification of the Met proto-oncogene, which may be a compensatory mechanism of NSCLCs against EGFR inhibition. To overcome this resistance, identification of new small-molecule natural compounds is crucial for cancer therapeutics. In this regard, SB365, saponin D from the root of Pulsatilla koreana which has been used as a traditional medicine in Korea for several diseases, has attracted wide interest. In the present study, SB365 effectively suppressed the proliferation of gefitinib-resistant HCC827GR NSCLC cells with Met amplification. Notably, our data revealed that SB365 inhibited the phosphorylation of Met and the downstream signaling pathway required for growth and survival in the Met-amplified HCC827GR cells. Moreover, SB365 suppressed the anchorage-independent growth, migration and invasion along with induction of apoptosis in the HCC827GR cells. Therefore, these results suggest that SB365 is good candidate as a natural product for use in the treatment of Met-amplified NSCLCs.

Research Progress on Natural Triterpenoid Saponins in the Chemoprevention and Chemotherapy of Cancer

Triterpenoid saponins are glycosides with remarkable structural and bioactive diversity. They are becoming increasingly significant in the treatment of cancer due to their efficacy and safety. This chapter provides an update on the sources, pharmacological effects, structure-activity relationships, and clinical studies of anticancer triterpenoid saponins with a particular focus on the molecular mechanisms underlying their therapeutic properties. The correlative references and study reports described were collected through PubMed. The anticancer triterpenoid saponins enable the inhibition of cancer formation and progression by modulating multiple signaling targets related to cellular proliferation, apoptosis, autophagy, metastasis, angiogenesis, inflammation, oxidative stress, multidrug resistance, cancer stem cells, and microRNAs. This review provides new insights into the molecular basis of triterpenoid saponins in the chemoprevention and chemotherapy of cancer.