Telocinobufagin, a PLK1 suppressor that inhibits tumor growth and metastasis by modulating CDC25c and CTCF in HNSCC cells.

BACKGROUND: The high metastasis and mortality rates of head and neck squamous cell carcinoma (HNSCC) urgently require new treatment targets and drugs. A steroidal component of ChanSu, telocinobufagin (TBG), was verified to have anti-cancer effects in various tumors, but its activity and mechanism in anti-HNSCC were still unknown. PURPOSE: This study tried to demonstrate the anti-tumor effect of TBG on HNSCC and verify its potential mechanism. METHODS: The effect of TBG on cell proliferation and metastasis were performed and the TBG changed genes were detected by RNA-seq analysis in HNSCC cells. The GSEA and PPI analysis were used to identify the pathways targeted for TBG-regulated genes. Meanwhile, the mechanism of TBG on anti-proliferative and anti-metastasis were investigated in vitro and in vivo. RESULTS: The in vitro and in vivo experiments confirmed that TBG has favorable anti-tumor effects by induced G2/M phase arrest and suppressed metastasis in HNSCC cells. Further RNA-seq analysis demonstrated the genes regulated by TBG were enriched at the G2/M checkpoint and PLK1 signaling pathway. Then, the bioinformatic analysis of clinical data found that high expressed PLK1 were closely associated with poor overall survival in HNSCC patients. Furthermore, PLK1 directly and indirectly modulated G2/M phase and metastasis (by regulated CTCF) in HNSCC cells, simultaneously. TBG significantly inhibited the protein levels of PLK1 in both phosphorylated and non-phosphorylated forms and then, in one way, inactivated PLK1 failed to activate G2/M phase-related proteins (including CDK1, CDC25c, and cyclin B1). In another way, be inhibited PLK1 unable promote the nuclear translocation of CTCF and thus suppressed HNSC cell metastasis. In contrast, the anti-proliferative and anti-metastasis effects of TBG on HNSCC cell were vanished when cells high-expressed PLK1. CONCLUSION: The present study verified that PLK1 mediated TBG induced anti-tumor effect by modulated G2/M phase and metastasis in HNSCC cells.

Exploring the in vitro potential of royal jelly against glioblastoma and neuroblastoma: impact on cell proliferation, apoptosis, cell cycle, and the biomolecular content.

Neuroblastoma and glioblastoma are the most commonly seen nervous system tumors, and their treatment is challenging. Relatively safe and easy acquisition of nutraceutical natural products make them suitable candidates for anticancer research. Royal jelly (RJ), a superfood, has many biological and pharmacological activities. This study was conducted to, for the first time, elucidate its anticancer efficiency, even in high doses, on neuroblastoma and glioblastoma cell lines through cell viability, apoptosis, cell cycle and biomolecular content evaluation. We performed experiments with RJ concentrations in the range of 1.25-10 mg mL-1 for 48 h. Cell viability assays revealed a notable cytotoxic effect of RJ in a concentration-dependent manner. Treatment with a high dose of RJ significantly increased the apoptotic cell population of both cell lines. Furthermore, we observed G0-G1 phase arrest in neuroblastoma cells but G2-M arrest in glioblastoma cells. All these cellular changes are closely associated with the alterations of the macromolecular makeup of the cells, such as decreased saturated lipid, protein, DNA and RNA amounts, protein conformational changes, decreased protein phosphorylation and increased protein carbonylation. These cellular changes are associated with RJ triggered-ROS formation. The clear segregation between the control and the RJ-treated groups proved these changes, obtained from the unsupervised and supervised chemometric analysis. RJ has good anticancer activity against nervous system cancers and could be safely used with current treatment strategies.

Cytotoxicity of dioncophylline A and related naphthylisoquinolines in leukemia cells, mediated by NF-κB inhibition, angiogenesis suppression, G2/M cell cycle arrest, and autophagy induction.

BACKGROUND: Inhibition of NF-κB activity represents a strategy to treat acute myeloid leukemia, one of the most lethal leukemia types. Naphthylisoquinolines (NIQs) are cytotoxic alkaloids from lianas of the families Ancistrocladaceae and Dioncophyllaceae, which are indigenous to tropical rainforests. PURPOSE: Uncovering therapeutic possibilities and underlying molecular mechanisms of dioncophylline A and its derivatives towards NF-κB related cellular processes. METHODS: Resazurin-based cell viability assay was performed for dioncophylline A and three derivatives on wild-type CCRF-CEM and multidrug-resistant CEM/ADR5000 cells. Transcriptome analysis was executed to discover cellular functions and molecular networks associated with dioncophylline A treatment. Expression changes obtained by mRNA microarray hybridization were confirmed using qRT-PCR. Molecular docking was applied to predict the affinity of the NIQs with NF-κB. To validate the in silico approach, NF-κB reporter assays were conducted on HEK-Blue™ Null1 cells. Cell death mechanisms and cell cycle arrest were studied using flow cytometry. The potential activity on angiogenesis was evaluated with the endothelial cell tube formation assay on HUVECs using fluorescence microscopy. Intracellular NF-κB location in HEK-Blue™ Null1 cells was visualized with immunofluorescence. Finally, the anti-tumor activity of dioncophylline A was studied by a xenograft zebrafish model in vivo. RESULTS: Our study demonstrated that dioncophylline A and its derivatives exerted potent cytotoxicity on leukemia cells. Using Ingenuity Pathway Analysis, we identified the NF-κB network as the top network, and docking experiments predicted dioncophylline A and two of its derivatives sharing the same binding pocket with the positive control compound, triptolide. Dioncophylline A showed the best inhibitory activity in NF-κB reporter assays compared to its derivatives, caused autophagy rather than apoptosis, and induced G2/M arrest. It also prevented NF-κB translocation from the cytoplasm to the nucleus. Tube formation as an angiogenesis marker was significantly suppressed by dioncophylline A treatment. Finally, the remarkable anti-tumor activity of dioncophylline A was proven in zebrafish in vivo. CONCLUSION: Taken together, we report for the first time the molecular mechanism behind the cytotoxic effect of dioncophylline A on leukemia cells. Dioncophylline A showed strong cytotoxic activity, inhibited NF-κB translocation, significantly affected the NF-κB in silico and in vitro, subdued tube formation, induced autophagy, and exerted antitumor activity in vivo. Our findings enlighten both the cellular functions including the NF-κB signaling pathway and the cytotoxic mechanism affected by dioncophylline A.

Indigofera suffruticosa aerial parts extract induce G2/M arrest and ATR/CHK1 pathway in Jurkat cells.

BACKGROUND: Indigofera suffruticosa Mill. is used as a folk medicine for treating patients with leukemia, however very little is known regarding the molecular mechanism of its anti-leukemic activity and the chemical profile of the active extract. The present study aimed to reveal the molecular effect of I. suffruticosa aerial parts extract (ISAE) on leukemia cells and its chemical constituents. METHODS: Cytotoxicity of ISAE were determined by resazurin viability assay, multitox - Glo multiplex cytotoxicity assay, and Annexin V staining assay. Cell cycle profiles were revealed by propidium iodide staining assay. The effects of ISAE on G2/M arrest signaling and DNA damage were evaluated by Western blot assay and phospho-H2A.X staining assay. The chemical profile of ISAE were determined by tandem mass spectroscopy and molecular networking approach. RESULTS: We showed that the acute lymphoblastic leukemia cell line Jurkat cell was more responsive to ISAE treatment than other leukemia cell lines. In contrast, ISAE did not induce cytotoxic effects in normal fibroblast cells. Cell cycle analysis revealed that ISAE triggered G2/M arrest in Jurkat cells in dose- and time-dependent manners. Elevation of annexin V-stained cells and caspase 3/7 activity suggested ISAE-induced apoptosis. Furthermore, ISAE alone could increase the phosphorylation of CDK1 at Y15 and activate the ATR/CHK1/Wee1/CDC25C signaling pathway. However, the addition of caffeine, a widely used ATR inhibitor to ISAE, reduced the phosphorylation of ATR, CHK1, and CDK1, as well as G2/M arrest in Jurkat cells. Moreover, increased phospho-H2A.X stained cells indicated the involvement of DNA damage in the anti-leukemic effect of ISAE. Finally, qualitative analysis using UPLC-tandem mass spectroscopy and molecular networking revealed that tryptanthrin was the most abundant organoheterocyclic metabolite in ISAE. At equivalent concentrations to ISAE, tryptanthrin induced G2/M arrest of Jurkat cells, which can be prevented by caffeine. CONCLUSIONS: ISAE causes G2/M arrest via activating ATR/CHK1/CDK1 pathway and tryptanthrin is one of the active components of ISAE. Our findings provide subtle support to the traditional use of I. suffruitcosa in leukemia management in folk medicine.

Epiberberine induced p53/p21-dependent G2/M cell cycle arrest and cell apoptosis in gastric cancer cells by activating γ-aminobutyric acid receptor- ß3.

BACKGROUND AND PURPOSE: Epiberberine (EPI) is one of the most important bioalkaloid found in the rhizome of Coptis chinensis, which has been observed to exhibit pharmaceutical effects against gastric cancer (GC). Nevertheless, the potential mechanism of EPI against GC cells still remains unclear. This study aimed to identify the core receptor on GC cells through which EPI inhibited the growth of GC cells and to explore the underlying inhibitory mechanisms. METHODS: To identify hub receptor targets that respond to EPI treatment, RNA sequencing (RNA-Seq) data from a tumor-bearing mouse model were analyzed using bioinformatics method and molecular docking. The binding interaction between EPI and GABRB3 was validated through western blotting based-cellular thermal shift assay (WB-CETSA). To further verify the binding region between EPI and GABRB3 through circular dichroism (CD) chromatography, fragments of the extracellular and transmembrane domains of the GABRB3 protein were expressed and purified in vitro. Stable cell lines with the overexpression or knockdown of GABRB3 were established using the recombinant lentivirus system. MTT ((3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide)) assay, colony formation assay, invasion and migration experiments, and flow cytometry were conducted to validate the inhibitory effect of EPI on the GC cells via GABRB3. Additionally, western blotting was utilized to explore the potential inhibitory mechanisms. RESULTS: Through the combination of multiple bioinformatics methods and molecular docking, we found that the γ-aminobutyric acid type A receptor subunit -ß3 (GABRB3) might be the critical receptor target in response to EPI treatment. The results of WB-CETSA analysis indicated that EPI significantly promoted the thermostability of the GABRB3 protein. Importantly, EPI could directly bind to GABRB3 and alter the secondary structure of GABRB3 fragments similar to the natural agonist, γ-aminobutyric acid (GABA). The EPI-induced suppression of the malignant phenotype of GC cells was dependent on the presence of GABRB3. GABRB3 expression was positively correlated with TP53 in patients with GC. The binding of EPI to GABRB3 stimulated p53 accumulation in GC cells. This activated the p21/CDK1/cyclinB1 pathway, resulting in G2/M cell cycle arrest, and induced the Bcl-2/BAX/Caspase axis-dependent cell apoptosis. CONCLUSION: This study revealed the target receptor for EPI in GC cells and provided new insights into its anticancer mechanisms.

Antiproliferative and Apoptosis Effects of Hybrid Varieties of Vitis vinifera L. Sweet Sapphire and Sweet Surprise on Human Prostate Cancer Cells Using In Vitro and In Silico Approaches.

OBJECTIVE: Grape hybrids are characterized by different chemical compositions; often with high hybrids are characterized by different chemical compositions, often with a high phenolic content and a specific profile of anthocyanins. The aim of study was to characterize the constituents of hybrid Vitis vinifera L. varieties Sweet Sapphire (SA) and Sweet Surprise (SU) extracts and their influence on apoptosis induction and antiproliferative effects on human prostate cancer cells. METHODS: We used the MTT assay to evaluate the cytotoxic effect of extracts of SA and SU, on the prostate adenocarcinoma cell lines PC-3 and DU-145. To analyze the inhibiting impact by flow cytometry, used 24 and 48 hours. Anthocyanins were quantified by liquid chromatography and analysed by their absorption rate, hepatotoxicity, blood concentration, blood-brain barrier passage ability and maximum recommended dose by in silico approaches. RESULTS: Our results showed that malvidin derivatives present the highest content in both cultivars. We identified 14.46mg/100g malvidin-3-O-glycoside in SA and 2.76 mg/100 g in SU. A reduction in cell viability of DU-145 (45 and 65%) and PC-3 (63 and 67%) cells after 48h treatment with SA and SU, respectively, was found via MTT assay. Flow cytometry showed that the treatment with extracts from SA and SU had an inhibitory impact on cell development due to G2/M arrest and caused a rise in apoptotic cells compared to control group. None of the anthocyanin presented hepatotoxicity as well as blood-brain barrier passage ability. Peonidin 3-O-glucoside had the lower maximum recommended dose as well as the highest intestinal absorption rate. However, delphinidin 3-O-glucoside had the highest blood concentration values. CONCLUSION: The findings of this study highlight the potential of hybrid Vitis vinifera L. varieties as an important source of natural antioxidants and their protective effect against prostate cancer cells as well as elucidate in part their anthocyanin's metabolism.

Cucurbitacin C suppresses the progression of pancreatic ductal adenocarcinoma via inhibition of the cGMP-PKG-VASP axis.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most devastating diseases; it has a considerably poor prognosis and may become the second most lethal malignancy in the next 10 years. Chemotherapeutic resistance is common in PDAC; thus, it is necessary to exploit effective alternative drugs. In recent years, traditional folk medicines and their extracts have shown great potential in cancer treatment. The seed of Lagenaria siceraria (Molina) Standl. is a traditional medicine in Asia. Because of its analgesic effects and ability to reduce swelling, it is often used as an adjuvant treatment for abdominal tumors. Cucurbitacin compounds are extracts abundant in Lagenaria siceraria (Molina) Standl. Here, we found that cucurbitacin C (CuC), a member of the cucurbitacin family, has apparent anti-PDAC therapeutic properties. CuC decreased the viability and suppressed the proliferation of PDAC cells in a time- and dose-dependent manner. Further studies revealed that CuC inhibited cell migration and invasion by inhibiting epithelial-mesenchymal transition (EMT). In addition, G2/M arrest was induced, and the apoptotic pathway was activated. Transcriptomic and bioinformatic analyses showed that CuC inhibited the cGMP-PKG-VASP axis, increasing the content of cGMP to restore tumor characteristics. The antitumor activity of CuC in vivo was verified through animal experiments, and no obvious side effects were observed. Overall, our study indicates a candidate therapeutic compound for PDAC that is worthy of further development.

T52 attenuates oncogenic STAT3 signaling and suppresses osteosarcoma.

BACKGROUND: T52 is a steroidal saponin extracted from the traditional Chinese herb Rohdea fargesii (Baill.), and it is reported to possess strong anti-proliferative capabilities in human pharyngeal carcinoma cell lines. However, whether T52 has anti-osteosarcoma properties, and its potential mechanism is remains unknown. PURPOSE: To examine the outcome and underlying mechanism of T52 in osteosarcomas (OS). METHODS/STUDY DESIGNS: The physiological roles of T52 in OS cells were examined using CCK-8, colony formation (CF), EdU staining, cell cycle/apoptosis and cell migration/invasion assays. The relevant T52 targets against OS were assessed via bioinformatics prediction, and the binding sites were analyzed by molecular docking. Western blot analysis was carried out to examine the levels of factors associated with apoptosis, cell cycle, and STAT3 signaling pathway activation. RESULTS: T52 markedly diminished the proliferation, migration, and invasion of OS cells, and promoted G2/M arrest and apoptosis in a dose-dependent fashion (DDF) in vitro. Mechanistically, molecular docking predicted that T52 stably associated with STAT3 Src homology 2 (SH2) domain residues. Western blot revealed that T52 suppressed the STAT3 signaling pathway, as well as the expression of the downstream targets, such as, Bcl-2, Cyclin D1, and c-Myc. In addition, the anti-OS property of T52 were partially reversed by STAT3 reactivation, which confirmed that STAT3 signaling is critical for regulating the anti-OS property of T52. CONCLUSION: We firstly demonstrated that T52 possessed strong anti-osteosarcoma property in vitro, which was brought on by the inhibition of the STAT3 signaling pathway. Our findings provided pharmacological support for treating OS with T52.

Effect of acetone fraction of Ottelia alismoides on the G2/M cell cycle arrest and apoptosis in the human carcinoma cell lines.

ETHNOPHARMACOLOGICAL RELEVANCE: The North-eastern parts of India have immense therapeutic floras, Ottelia alismoides is an aquatic plant that has been in use for a long time in traditional medicine for treating diseases like cancer, tuberculosis, diabetes, febrifuge, hemorrhoids, and rubefacient. In lung and skin carcinoma cells with a high rate of proliferation and metastasis including drug resistance and non-specific target activity, generates important challenges towards their treatment strategy. Thus, finding novel therapeutic targets to treat lung and skin cancer progression is essential to enhance the patients' survival with treatment. AIM OF THE STUDY: The purpose of this study was to evaluate the apoptotic potential of acetone extract of O. alismoides (L.) Pers. (OA-AC) and to identify the compounds responsible for this effect, HRLC-MS-QTOF analysis of the extract has been undertaken along with in-silico molecular docking analysis of the identified compounds. MATERIALS AND METHODS: A549 and A431 cells were treated with acetone extract of O. alismoides (OA-AC) at 24 h and 48 h exposure and cell cycle phase distribution was evaluated and also apoptosis induction activity was evaluated by OA-EtBr staining and Mitochondrial outer membrane potential assay. Western blotting was performed for the evaluation of apoptotic protein expression. At last, the HR-LCMS of OA-AC was analyzed to identify the compounds responsible for the apoptotic activity of the extract. RESULTS: The cell cycle phase distribution analysis in A549 and A431 cells at 24hrs exposure with 10 µg/mL and 25 µg/mL of OA-AC showed a potent arrest or blockage at the G2/M phase of the cell cycle with reduced expression of cyclin B and p-Cdc2. At 48 h exposure, apoptosis was observed in these cancer cells with elevated expression of Bax, p21 and cleaved caspase 3 and reduced expression of the Bcl2. CONCLUSION: AO-EtBr staining of these cancer cells reveals that the death induced by OA-AC was apoptotic in nature with depolarization of mitochondrial membrane due to loss or damage of the mitochondrial membrane. The HRLC-MS-QTOF analysis of OA-AC depicted 14 major isolable compounds and molecular docking analysis displayed 4 compounds that might act as an inhibitor of cyclin B for G2/M phase arrest that leads to apoptotic induction in the cells.

The Complex Roles of DNA Repair Pathways, Inhibitors, Hyperthermia, and Contact Inhibition in Cell Cycle Halts.

The cell cycle has the capacity to safeguard the cell's DNA from damage. Thus, cell cycle arrest can allow tumor cells to investigate their own DNA repair processes. Cancer cells become extremely reliant on G1-phase cyclin-dependent kinases due to mutated oncogenes and deactivated tumor suppressors, producing replication stress and DNA damage during the S phase and destroying checkpoints that facilitate progression through the S/G2/M phase. DNA damage checkpoints activate DNA repair pathways to prevent cell proliferation, which occurs when the genome is damaged. However, research on how cells recommence division after a DNA lesion-induced arrest is insufficient which is merely the result of cancer cells' susceptibility to cell cycle arrest. For example, defects in the G1 arrest checkpoint may cause a cancer cell to proliferate more aggressively, and attempts to fix these complications may cause the cell to grow more slowly and eventually die. Defects in the G2-M arrest checkpoint may enable a damaged cell to enter mitosis and suffer apoptosis, and attempts to boost the effectiveness of chemotherapy may increase its cytotoxicity. Alternatively, attempts to promote G2-M arrest have also been linked to increased apoptosis in the laboratory. Furthermore, variables, such as hyperthermia, contact inhibition, nucleotide shortage, mitotic spindle damage, and resting phase effects, and DNA replication inhibitors add together to halt the cell cycle. In this review, we look at how nucleotide excision repair, MMR, and other variables, such as DNA replication inhibitors, hyperthermia, and contact inhibition, contribute to the outlined processes and functional capacities that cause cell cycle arrest.

Oligo-Fucoidan supplementation enhances the effect of Olaparib on preventing metastasis and recurrence of triple-negative breast cancer in mice.

BACKGROUND: Seaweed polysaccharides have been recommended as anticancer supplements and for boosting human health; however, their benefits in the treatment of triple-negative breast cancers (TNBCs) and improving immune surveillance remain unclear. Olaparib is a first-in-class poly (ADP-ribose) polymerase inhibitor. Oligo-Fucoidan, a low-molecular-weight sulfated polysaccharide purified from brown seaweed (Laminaria japonica), exhibits significant bioactivities that may aid in disease management. METHODS: Macrophage polarity, clonogenic assays, cancer stemness properties, cancer cell trajectory, glucose metabolism, the TNBC 4T1 cells and a 4T1 syngeneic mouse model were used to inspect the therapeutic effects of olaparib and Oligo-Fucoidan supplementation on TNBC aggressiveness and microenvironment. RESULTS: Olaparib treatment increased sub-G1 cell death and G2/M arrest in TNBC cells, and these effects were enhanced when Oligo-Fucoidan was added to treat the TNBC cells. The levels of Rad51 and programmed death-ligand 1 (PD-L1) and the activation of epidermal growth factor receptor (EGFR) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) facilitate drug resistance and TNBC metastasis. However, the combination of olaparib and Oligo-Fucoidan synergistically reduced Rad51 and PD-L1 levels, as well as the activity of EGFR and AMPK; consistently, TNBC cytotoxicity and stemness were inhibited. Oligo-Fucoidan plus olaparib better inhibited the formation of TNBC stem cell mammospheroids with decreased subpopulations of CD44high/CD24low and EpCAMhigh cells than monotherapy. Importantly, Oligo-Fucoidan plus olaparib repressed the oncogenic interleukin-6 (IL-6)/p-EGFR/PD-L1 pathway, glucose uptake and lactate production. Oligo-Fucoidan induced immunoactive and antitumoral M1 macrophages and attenuated the side effects of olaparib, such as the promotion on immunosuppressive and protumoral M2 macrophages. Furthermore, olaparib plus Oligo-Fucoidan dramatically suppressed M2 macrophage invasiveness and repolarized M2 to the M0-like (F4/80high) and M1-like (CD80high and CD86high) phenotypes. In addition, olaparib- and Oligo-Fucoidan-pretreated TNBC cells resulted in the polarization of M0 macrophages into CD80(+) M1 but not CD163(+) M2 macrophages. Importantly, olaparib supplemented with oral administration of Oligo-Fucoidan in mice inhibited postsurgical TNBC recurrence and metastasis with increased cytotoxic T cells in the lymphatic system and decreased regulatory T cells and M2 macrophages in tumors. CONCLUSION: Olaparib supplemented with natural compound Oligo-Fucoidan is a novel therapeutic strategy for reprogramming cancer stemness, metabolism and the microenvironment to prevent local postsurgical recurrence and distant metastasis. The combination therapy may advance therapeutic efficacy that prevent metastasis, chemoresistance and mortality in TNBC patients.

Study on inhibition of Britannin on triple-negative breast carcinoma through degrading ZEB1 proteins.

BACKGROUND: Triple-negative breast carcinomas (TNBCs) are a breast carcinoma with the most aggressive form, which is demonstrated as enhanced invasion and recurrence. Britannin is extracted mainly from the traditional Chinese herb Inula japonica Thunb, and few studies have focused on its effect on TNBC. Moreover, there is still no report concerning the role of Britannin in degrading the transcripts of Zinc finger E-box-binding homeobox 1 (ZEB1) proteins. PURPOSE: To explore the potential effect of Britannin on invasion and stemness of TNBCs and its underlying mechanism. METHODS: Cellular activity was measured using MTT, and cell cycle was measured using flow cytometry (FCM). The effect of Britannin on the migrating and invading abilities of MDA-MB-231 and 4T1 cells were measured using the wound healing and transwell assays. The sizes and number of breast carcinoma cells were measured by tumor formation assay and in vitro limiting-dilution assay. CD44 expression in tumor spheroids was tested by immunofluorescence assay. Nextly, the expressions of epithelial-mesenchymal transition (EMT) markers and ZEB1 protein expressional level were detected by western blot . ZEB1 mRNA expressional level was analyzed using RT-qPCR. Drug affinity-responsive target stability (DARTS) method was used to detect the binding activity between Britannin and ZEB1. Co-immunoprecipitation (Co-IP) analysis was applied to test the ubiquitination of ZEB1. The mouse models for experimental lung metastasis of 4T1 cells were established to detect the anti-metastasis effect of Britannin in vivo, and the expressional levels of EMT markers in lung metastases were detected by immunohistochemistry. RESULTS: Britannin could inhibit cell growth and G2/M arrest in TNBC cells. Britannin could inhibit the migrating and invading ability without inducing severe apoptosis of MDA-MB-231 and 4T1 cells. Meanwhile, Britannin reduced the size and number of spheroids formed in these two cells, and decreased the expressional level of stem cells biomarker CD44 in tumor spheroids. Mechanism research showed that Britannin specifically bound to ZEB1 and induced its ubiquitination in MDA-MB-231 cells. Afterwards, Britannin disturbed protein stability and promoted ZEB1 protein degradation. Importantly, Britannin could not inhibit cell invasion and spheroid formation after ZEB1 expression was knocked down. Finally, Britannin inhibition of 4T1 cell metastasis was confirmed through establishing mouse models for the experimental lung metastasis. It was proved that both Britannin and paclitaxel could decrease the lung metastases, and Britannin could also down-regulate the protein expressional levels of ZEB1, MMP9 and CD44. CONCLUSION: This study reveals that Britannin suppresses the invasion and metastasis of TNBC cells through degrading ZEB1, which suggests that Britannin can be used to prevent tumor metastasis and recurrence via degrading ZEB1proteins.

The role of ER stress and ATP/AMPK in oxidative stress meditated hepatotoxicity induced by citrinin.

Citrinin, a secondary metabolite, can pose serious risks to the environment and organisms, but its hepatotoxic mechanisms are still unclear. Histopathological and ultrastructural results showed that citrinin-induced liver injury in Kunming mice, and the mechanism of citrinin-induced hepatotoxicity was studied in L02 cells. Firstly, citrinin mades L02 cell cycle arrest in G2/M phase by inhibition of cyclin B1, cyclin D1, cyclin-dependent kinases 2 (CDK2), and CDK4 expression. Secondly, citrinin inhibits proliferation and promotes apoptosis of L02 cells via disruption of mitochondria membrane potential, increase Bax/Bcl-2 ration, activation of caspase-3, 9, and enhance lactate dehydrogenase (LDH) release. Then, citrinin inhibits superoxide dismutase (SOD) activity and increases the accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS), resulting oxidative damage in L02 cells; upregulates the protein expression of binding immunoglobulin protein (Bip), C/EBP homologous protein (CHOP), PKR-like ER kinase (PERK) and activating transcription factor6 (ATF6), inducing ER stress in L02 cells; increases the phosphorylation of AMP-activated protein kinase (AMPK) and decreases the content of adenosine-triphosphate (ATP), activating AMPK pathway in L02 cells. Eventually, pretreatment with NAC, an ROS inhibitor, alleviates citrinin-induced cell cycle G2/M arrest and apoptosis by inhibiting ROS-mediated ER stress; pretreatment with 4-PBA, an ER stress inhibitor, reversed ER stress and p-AMPK; pretreatment with dorsomorphin, an AMPK inhibitor, decreases citrinin-induced cell cycle G2/M arrest and apoptosis. In summary, citrinin induces cell cycle arrest and apoptosis to aggravate liver injury by activating ROS-ER stress-AMPK signaling pathway.

Osmundacetone modulates mitochondrial metabolism in non-small cell lung cancer cells by hijacking the glutamine/glutamate/α-KG metabolic axis.

BACKGROUND: Osmundacetone (OSC) is a bioactive phenolic compound isolated from Phellinus igniarius and that was shown to exert cytotoxic effects on cancer cells in our previous work. The antiproliferative impact of OSC on non-small cell lung cancer (NSCLC) and the underlying mechanisms, however, have not been studied. PURPOSE: This study aimed to explore the antiproliferative effect of OSC on NSCLC cells and the mechanisms involved. METHODS: Cell viability, colony formation and cell cycle distribution were measured following exposure to OSC in vitro. The anticancer activity of OSC was also examined using a xenograft growth assay in vivo. Furthermore, serum metabolomics analysis by GC-MS was done to detect alterations in the metabolic profile. Next, expression of GLS1 and GLUD1, the key enzymes in glutamine metabolism, was evaluated using RT-PCR and western blot. α-KG and NADH metabolites were assessed by ELISA. Mitochondrial functions and morphology were evaluated using the JC-1 probe and transmission electron microscopy, respectively. The ATP production rate in mitochondria of cells with OSC treatment was determined using a Seahorse XFe24 Analyzer. RESULTS: OSC selectively reduced the proliferation of A549 and H460 cells. OSC triggered G2/M cell cycle arrest and decreased the cell clone formation. A mouse xenograft model revealed that OSC inhibited tumor growth in vivo. Findings of serum metabolomics analyses indicated that the anticancer function of OSC was related to disorders of glutamine metabolism. Such a speculation was further verified by the expression level of GLUD1, which was downregulated by OSC treatment. Concentrations of the related metabolites α-KG and NADH were reduced in response to OSC treatment. Moreover, OSC led to disorganization of the mitochondrial ultrastructure and a decrease in mitochondrial membrane potential. OSC also decreased ATP production via oxidative phosphorylation (OXPHOS) but did not affect glycolysis in NSCLC cells. CONCLUSION: The key role of OSC in mitochondrial energy metabolism in NSCLC cells is to suppress tumor development and cell proliferation downregulating GLUD1 to inhibit the glutamine/glutamate/α-KG metabolic axis and OXPHOS. It indicats that OSC might be a potential natural agent for personalized medicine and an anticancer metabolic modulator in NSCLC chemotherapy.

Arachidin-1, a Prenylated Stilbenoid from Peanut, Induces Apoptosis in Triple-Negative Breast Cancer Cells.

Triple-negative breast cancer (TNBC) is unresponsive to typical hormonal treatments, causing it to be one of the deadliest forms of breast cancer. Investigating alternative therapies to increase survival rates for this disease is essential. The goal of this study was to assess cytotoxicity and apoptosis mechanisms of prenylated stilbenoids in TNBC cells. The prenylated stilbenoids arachidin-1 (A-1) and arachidin-3 (A-3) are analogs of resveratrol (RES) produced in peanut upon biotic stress. The anticancer activity of A-1 and A-3 isolated from peanut hairy root cultures was determined in TNBC cell lines MDA-MB-231 and MDA-MB-436. After 24 h of treatment, A-1 exhibited higher cytotoxicity than A-3 and RES with approximately 11-fold and six-fold lower IC50, respectively, in MDA-MB-231 cells, and nine-fold and eight-fold lower IC50, respectively, in MDA-MB-436 cells. A-1 did not show significant cytotoxicity in the non-cancerous cell line MCF-10A. While A-1 blocked cell division in G2-M phases in the TNBC cells, it did not affect cell division in MCF-10A cells. Furthermore, A-1 induced caspase-dependent apoptosis through the intrinsic pathway by activating caspase-9 and PARP cleavage, and inhibiting survivin. In conclusion, A-1 merits further research as a potential lead molecule for the treatment of TNBC.

Neochamaejasmine A Promotes Apoptosis and Cell Cycle Arrest in B16F10 Melanoma Cells via JNK and p38 MAPK Signaling Pathway.

BACKGROUND: The incidence of melanoma has been increasing over the last 30 years. The most common treatments, such as surgery, chemotherapy, and radiotherapy, frequently cause serious damage to the body. It is therefore critical to develop a new therapeutic strategy for the treatment of melanoma. OBJECTIVES: This research aims to evaluate the anti-tumor effect of Neochamaejasmine A (NCA) on B16F10 melanoma cells and the underlying molecular mechanisms. METHODS: The CCK-8 kit was utilized to assay the influence of NCA on the vitality of B16F10 cells. Modifications in B16F10 cells morphology were observed using a phase-contrast microscope. Apoptosis of B16F10 melanoma cells was assessed by Hoechst 33258, Annexin V and propidium iodide staining. Cell cycle was detected using a commercial kit by flow cytometry. The mRNA and protein expression levels associated with apoptosis and cell cycle arrest were detected by RT-PCR and Western blot. The expression level of pathway proteins was assessed using Western blot. RESULTS: It was found that the proliferation of B16F10 cells was inhibited by NCA in concentration- and time-dependent manners. NCA promoted apoptosis by halting the cell cycle at the G2/M phase. After treatment with NCA, cell apoptosis was confirmed by Hoechst 33258 staining. NCA triggered the cell cycle to seize at the G2/M stage by downregulating cyclin B1 and cyclin-dependent kinase 2 (CDC2) expression. Moreover, the mRNA and protein expression of cleaved caspase- 9 and Bcl-2-associated X-protein (Bax) were increased, whereas there was a decline in the expression of B-cell lymphoma 2 (Bcl-2). The p-p38/p38 and phosphorylated c-Jun N-terminal kinase (p-JNK/JNK) ratio were also elevated by NCA. The apoptosis and G2/M cell cycle arrest were inhibited in cells co-treated with the p38 inhibitor SB203580 and JNK inhibitor SP600125. The expression of apoptosis-related proteins Bax was decreased, and Bcl-2 was increased. CONCLUSION: The findings of this study showed that NCA could induce apoptosis and cell cycle arrest in B16F10 melanoma cells by activating JNK and p38 MAPK signaling pathway.

Mineral Nanomedicine to Enhance the Efficacy of Adjuvant Radiotherapy for Treating Osteosarcoma.

It is vital to remove residual tumor cells after resection to avoid the recurrence and metastasis of osteosarcoma. In this study, a mineral nanomedicine, europium-doped calcium fluoride (CaF2:Eu) nanoparticles (NPs), is developed to enhance the efficacy of adjuvant radiotherapy (i.e., surgical resection followed by radiotherapy) for tumor cell growth and metastasis of osteosarcoma. In vitro studies show that CaF2:Eu NPs (200 µg/mL) exert osteosarcoma cell (143B)-selective toxicity and migration-inhibiting effects at a Eu dopant amount of 2.95 atomic weight percentage. These effects are further enhanced under X-ray irradiation (6 MeV, 4 Gy). Furthermore, in vivo tests show that intraosseous injection of CaF2:Eu NPs and X-ray irradiation have satisfactory therapeutic efficacy in controlling primary tumor size and inhibiting primary tumor metastasis. Overall, our results suggest that CaF2:Eu NPs with their osteosarcoma cell (143B)-selective toxicity and migration-inhibiting effects combined with radiotherapy might be nanomedicines for treating osteosarcoma after tumor resection.

A Second Near-Infrared Ru(II) Polypyridyl Complex for Synergistic Chemo-Photothermal Therapy.

The clinical success of cisplatin ushered in a new era of the application of metallodrugs. When it comes to practice, however, drug resistance, tumor recurrence, and drug systemic toxicity make it implausible to completely heal the patients. Herein, we successfully transform an electron acceptor [1, 2, 5]thiadiazolo[3,4-g]quinoxaline into a novel second near-infrared (NIR-II) fluorophore H7. After PEGylation and chelation, HL-PEG2k exhibits a wavelength bathochromic shift, enhanced photothermal conversion efficiency (41.77%), and an antineoplastic effect against glioma. Its potential for in vivo tumor tracking and image-guided chemo-photothermal therapy is explored. High levels of uptake and high-resolution NIR-II imaging results are thereafter obtained. The hyperthermia effect could disrupt the lysosomal membranes, which in turn aggravate the mitochondria dysfunction, arrest the cell cycle in the G2 phase, and finally lead to cancer cell apoptosis. HL-PEG2k displays a superior biocompatibility and thus can be a potential theranostic platform to combat the growth and recurrence of tumors.

Dehydroevodiamine inhibits lung metastasis by suppressing survival and metastatic abilities of colorectal cancer cells.

BACKGROUND: Despite the rising 5-year survival rate of colorectal cancer (CRC) patients, the survival rate decreases as the stage progress, and a low survival rate is highly associated with metastasis. PURPOSE: The purpose of our study is to investigate the effect of dehydroevodiamine (DHE) on the lung metastasis of CRC and the proliferation of CRC cells. STUDY DESIGN: Cell death was confirmed after DHE treatment on several CRC cell lines. The mechanism of cell cytotoxicity was found using flow cytometry. After that, the expression of the proteins or mRNAs related to the cell cytotoxicity was confirmed. Also, anti-metastatic ability of DHE in CRC cells was measured by checking the expression of Epithelial to Mesenchymal Transition (EMT) markers. Lung metastasis mouse model was established, and DHE was administered orally for 14 days. RESULTS: DHE suppressed the viability of HCT116, CT26, SW480, and LoVo cells. DHE treatment led to G2/M arrest via a reduction of cyclin B1/CDK1 and caspase-dependent apoptosis. It also induced autophagy by regulating LC3-II and beclin-1 expression. Additionally, migration and invasion of CRC cells were decreased by DHE through regulation of the expression of EMT markers. Oral administration of DHE could inhibit the lung metastasis of CT26 cells in an in vivo model. CONCLUSION: Our study demonstrated that DHE has a potential therapeutic effect on colorectal cancer metastasis.

Cdc25C/cdc2/cyclin B, raf/MEK/ERK and PERK/eIF2α/CHOP pathways are involved in forskolin-induced growth inhibition of MM.1S cells by G2/M arrest and mitochondrion-dependent apoptosis.

Multiple myeloma (MM) remains an incurable hematological malignancy characterized by proliferation and accumulation of plasma cells in the bone marrow. Innovative and effective therapeutic approaches that are able to improve the outcome and the survival of MM sufferers, especially the identification of novel natural compounds and investigation of their anti-MM mechanisms, are needed. Here, we investigated the effects and the potential mechanisms against MM of forskolin, a diterpene derived from the medicinal plant Coleus forskohlii, in MM cell line MM.1S. CCK-8 assay showed that forskolin significantly inhibited MM.1S cells viability in a time- and dose-dependent manner. Furthermore, we demonstrated that forskolin induced G2/M phase arrest with a remarkable increase of p-cdc25c, p-cdc2, and a decrease of cyclin B1, indicating the suppression of cdc25C/cdc2/cyclin B pathway. Moreover, we found that forskolin induced mitochondrion-dependent apoptosis which was accompanied by the increase of pro-apoptotic proteins Bax, Bad, Bim and Bid, the decrease of anti-apoptotic proteins Bcl-2 and Bcl-xl, the changes of the mitochondrial membrane potential (MMP) and increase of cleaved caspase-9, cleaved caspase-3 and cleaved PARP. Of note, we demonstrated that forskolin induced a decrease of p-C-Raf, p-MEK, p-ERK1/2 and p-p90Rsk, and an increase of p-PERK, p-eIF2α and CHOP, which indicated that the inhibition of Raf/MEK/ERK pathway and activation of PERK/eIF2α/CHOP pathway were involved, at least partially, in forskolin-induced MM.1S cells apoptosis. These findings confirm the anti-MM action of forskolin and extend the understanding of its anti-MM mechanism in MM.1S cells, as well as reinforcing the evidence for forskolin as a natural chemotherapeutic compound against MM.