Isolation, structure elucidation and bioactivity of secondary metabolites produced by marine derived Streptomonospora arabica VSM-25

The strain VSM-25 with an exhilarating bioactive potential isolated during our systematic screening of marine actinomycetes was identified as Streptomonospora arabica based on polyphasic taxonomy. The ethyl acetate extract of culture filtrate was purified by silica gel column chromatography. The chemical structure of active compounds was determined by NMR, FTIR, and ESIMS and were established as Indole-3-carboxaldehyde (C1), 2, 3-dihydroxy benzoic acid (C2), Vanillic acid (C3), Daidzein (C4), and 3, 4-Dihydroxy benzaldehyde (C5). The antimicrobial activities of the compounds were tested against medicinally and agriculturally significant bacteria and fungi. C1 displayed a high inhibitory effect against bacteria and fungi to that of the other compounds tested. C5 exerted the strongest scavenging activity of free radicals such as DPPH and NO at a concentration of 400 µg/mL. C1 inhibited alpha-amylase effectively at 400 µg/mL although it was less potent than acarbose. C3 and C4 exerted significant anti-inflammatory and anti-arthritic activities at 400 µg/mL. The anti-inflammatory activity of compound C3 was found to be more potent than Diclofenac sodium, the reference drug. MTT assays of five compounds against MDA-MB-231 and MCF-7 cell lines using taxol as standard documented cytotoxicity. C4 showed highest activity of 67.81% and 54.33% (IC50 -1 µg/mL) against MDA-MB-231 and MCF-7. The cytotoxicity of five compounds was also evaluated by soft agar colony forming assay to determine the ability of MDA-MB-231 cells to proliferate while cell cycle arrest at sub G1 and induction of apoptosis was documented with MDA-MB-231 cells after treatment with C1, C2, C3, C4, and C5.

Isolation, structure elucidation and bioactivity of secondary metabolites produced by marine derived Streptomonospora arabica VSM-25-Supplementary data

The strain VSM-25 with an exhilarating bioactive potential isolated during our systematic screening of marine actinomycetes was identified as Streptomonospora arabica based on polyphasic taxonomy. The ethyl acetate extract of culture filtrate was purified by silica gel column chromatography. The chemical structure of active compounds was determined by NMR, FTIR, and ESIMS and were established as Indole-3-carboxaldehyde (C1), 2, 3-dihydroxy benzoic acid (C2), Vanillic acid (C3), Daidzein (C4), and 3, 4-Dihydroxy benzaldehyde (C5). The antimicrobial activities of the compounds were tested against medicinally and agriculturally significant bacteria and fungi. C1 displayed a high inhibitory effect against bacteria and fungi to that of the other compounds tested. C5 exerted the strongest scavenging activity of free radicals such as DPPH and NO at a concentration of 400 µg/mL. C1 inhibited alpha-amylase effectively at 400 µg/mL although it was less potent than acarbose. C3 and C4 exerted significant anti-inflammatory and anti-arthritic activities at 400 µg/mL. The anti-inflammatory activity of compound C3 was found to be more potent than Diclofenac sodium, the reference drug. MTT assays of five compounds against MDA-MB-231 and MCF-7 cell lines using taxol as standard documented cytotoxicity. C4 showed highest activity of 67.81% and 54.33% (IC50 -1 µg/mL) against MDA-MB-231 and MCF-7. The cytotoxicity of five compounds was also evaluated by soft agar colony forming assay to determine the ability of MDA-MB-231 cells to proliferate while cell cycle arrest at sub G1 and induction of apoptosis was documented with MDA-MB-231 cells after treatment with C1, C2, C3, C4, and C5.

Discovery of a small-molecule inhibitor of carbamoyl phosphate synthase 1 and its anti-colorectal cancer mechanism / 药学学报

The carbamoyl phosphate synthase 1 (CPS1) enzyme is involved in the first phase of the urea cycle, providing a prerequisite molecule for pyrimidine synthesis, as well as promoting tumor cell proliferation and growth. Studies have found that CPS1 is highly expressed in a variety of tumors, including colorectal cancer, lung cancer, etc. and its overexpression is related to the poor prognosis of tumors. Thus, small molecules targeted to inhibit the function of CPS1 in tumors may provide therapeutic benefits for cancer patients who overexpress CPS1. In this study, the function of CPS1 was investigated in vitro, and we found that overexpression of CPS1 can enhance the migration ability of colorectal cancer cells HCT15. Here, based upon the existing crystal structure, combined with high-throughput virtual screening, we obtained 8 candidate small molecule compounds. In vitro activity evaluation, we found that compound 3 has good anti-HCT15, HCT116 cell proliferation activity (HCT15, IC50, 7.69 ± 1.10 μmol‧L-1, HCT116, IC50, 13.53 ± 0.46 μmol‧L-1). Subsequently, molecular docking and molecular dynamics (MD) simulation analysis showed that, compound 3 could target and inhibit the activity of CPS1. In vitro studies showed that compound 3 could inhibit the migration of HCT15 cells, as well as induced cell cycle arrest and apoptosis. Taken together, this study found that compound 3 is a potential small molecule inhibitor that targets CPS1, which provides the experimental basis and theoretical basis for the development of targeted intervention small molecule therapeutic drugs. Based upon the chemical structure of compound 3, we will shed new light on further optimizing its activity and therapeutic potential, which may provide a therapeutic benefit to the patients with CPS1-related tumors.

Study on the mechanism of curcumol inhibiting the proliferation of breast cancer cells T 47D / 中国药房

OBJECTIVE To study the mechanism of curcumol inhibiting the pro liferation of breast cancer cells T 47D. METHODS MTT assay was used to detect the inhibitory effects of different doses of curcumol （0，6.25，12.5，25，50，100 μg/mL）on the proliferation of T 47D cells. After treated with curcumol （12.5，25，50，100 μg/mL），the morphology of T 47D cells was observed by inverted phase contrast microscope. The cell cycle and the levels of reactive oxygen species （ROS）were detected by flow cytometry. Quantitative real-time PCR （qRT-PCR）was used to detect the expressions of proliferating cell nuclear antigen （PCNA），cell cycle regular p 21 and cyclin-dependent kinase 2（CDK2）mRNA. Western blot assay was used to detect the protein expression of CDK 2，CDK6，Cyclin D ，PCNA，nucler transcription factor E 2-related factor （Nrf2）and Kelch-like ECH associated protein 1（Keap1）. Breast cancer cells T 47D were divided into 2 groups，one group was given different doses of curcumol ，and another group was given curcumol 33 μg/mL for 6，12，24，48 h. After the optimal oxidation time and administration concentration were determined according to the results of the above two groups ，the blank control group ，N-acetylcysteine（NAC）group（ROS antioxidant NAC alone ），curcumol group （curcumol alone ），curcumol combined with NAC group （pretreatment with ROS antioxidant NAC ，and then adding into curcumol ）. Cell cycle and fluorescence intensity of ROS were detected. RESULTS Curcumol could significantly increase the inhibitory rate of the proliferation of T 47D cells （P＜0.05 or P＜0.01），and showed a certain dose and time dependent trend. Curcumol blocked the ， cycle in the G 1 phase and significantly increased the level of ROS （P＜0.05 or P＜0.01）；ROS antioxidant NAC could significantly reverse above inductive effect of curcumol （P＜ 0.01）. qRT-PCR showed that curcumol down-regulated the com expression of PCNA and CDK 2 mRNA and up-regulated the expression of p 21 mRNA（P＜0.05 or P＜0.01）. Western blot assay showed that curcumol significantly down-regulated the edu.cn protein expression of Keap 1，Nrf2，CDK2，CDK6 and Cyclin D（P＜0.05，P＜0.01）；ROS antioxidant NAC could reverse the down-regulation effects of curcumol on the expression of these proteins（P＜0.05 or P＜0.01）. CONCLUSIONS Curcumol may induce oxidative stress and cell arrest in G 1 phase to inhibit the proliferation of T 47D cells.

The cell cycle inhibitor P21 promotes the development of pulmonary fibrosis by suppressing lung alveolar regeneration

The cell cycle inhibitor P21 has been implicated in cell senescence and plays an important role in the injury-repair process following lung injury. Pulmonary fibrosis (PF) is a fibrotic lung disorder characterized by cell senescence in lung alveolar epithelial cells. In this study, we report that P21 expression was increased in alveolar epithelial type 2 cells (AEC2s) in a time-dependent manner following multiple bleomycin-induced PF. Repeated injury of AEC2s resulted in telomere shortening and triggered P21-dependent cell senescence. AEC2s with elevated expression of P21 lost their self-renewal and differentiation abilities. In particular, elevated P21 not only induced cell cycle arrest in AEC2s but also bound to P300 and β-catenin and inhibited AEC2 differentiation by disturbing the P300-β-catenin interaction. Meanwhile, senescent AEC2s triggered myofibroblast activation by releasing profibrotic cytokines. Knockdown of P21 restored AEC2-mediated lung alveolar regeneration in mice with chronic PF. The results of our study reveal a mechanism of P21-mediated lung regeneration failure during PF development, which suggests a potential strategy for the treatment of fibrotic lung diseases.

Mechanism of HSP90 Inhibitor AUY-922 Reversing ALK Inhibitor Resistance in Human Neuroblastoma Cells / 肿瘤防治研究

Objective To investigate the mechanism of HSP90 inhibitor AUY-922 reversing the resistance of human neuroblastoma cells to the second generation ALK inhibitor TAE684. Methods The effect of AUY-922 on the proliferation of human neuroblastoma cells SH-SY5Y and KELLY carrying ALK F1174L gene was detected by MTT method. The effect of AUY-922 on cell cycle of SH-SY5Y and KELLY cells was detected by flow cytometry. The effects of AUY-922 on cyclin Cdc2, ALK protein and downstream signal pathways p-Akt, p-Erk, p-stat3 in SH-SY5Y and KELLY cells were detected by Western blot. Results AUY-922 could significantly inhibit the proliferation of SH-SY5Y and KELLY cells, and the IC50 were about 0.30 μmol/L and 0.12 μmol/L, respectively. AUY-922 could induce cell cycle arrest of SH-SY5Y and KELLY cells in G2/M phase in a dose-dependent manner. AUY-922 could degrade Cdc2 and ALK proteins in SH-SY5Y and KELLY cells in a dose-dependent manner, and reduce the levels of p-Akt, p-Erk and p-stat3. Conclusion The reversal effect of HSP90 inhibitor AUY-922 on drug resistance of human neuroblastoma to ALK inhibitor may be related to its induction of G2/M cell cycle arrest, the degradation of ALK protein and the inhibition of downstream signal pathway.

Scutellariae Barbatae Herba Extract Promotes Cycle Arrest of Nasopharyngeal Carcinoma Cells by Inhibiting STAT3/SKP2 Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the effect of Scutellariae Barbatae Herba extract on on the cycle arrest of nasopharyngeal carcinoma cells and the possible mechanism by adding different concentration of Scutellariae Barbatae Herba extract （0.25， 0.5， 1 g·L-1） in the culture medium， taking CNE1 （nasopharyngeal carcinoma cells） as the research object. MethodAfter the treatment of CNE1 by Scutellariae Barbatae Herba extract， cell counting kit-8 （CCK-8） was used to detect cell proliferation， and Giemsa staining was used to detect the clone formation rate. Flow cytometry was used to detect cell cycle distribution， and reverse transcription-polymerase chain reaction （ RT-PCR） assay and Western blot assay were used to detect the relative expression of messenger ribonucleic acid （mRNA） by small interfering RNA （siRNA） or overexpression. ResultAs compared with the blank group， the proliferation and colony formation rate of CNE1 in the Scutellariae Barbatae Herba extract group significantly decreased （P<0.05， P<0.01） in a dose and time-dependent manner， whereas the percentage of cells in the presynthetic phase （G0/G1） increased （P<0.05， P<0.01）. The expression level of S-phase kinase associated protein 2 （SKP2） in the Scutellariae Barbatae Herba extract group significantly decreased （P<0.01） as compared with the blank group. As compared with the Scutellariae Barbatae Herba extract group， the protein levels of p21 and p27 significantly decreased in the overexpressed SKP2+ Scutellariae Barbatae Herba extract group （P<0.01）. As compared with the blank group， the signal activation and the phosphorylation level of signal transducer and activator of transcription 3 （STAT3） of CNE1 in the S. barbata extract group significantly decreased （P<0.05， P<0.01）. ConclusionScutellariae Barbatae Herba extract effectively inhibits the proliferation of CNE1， and the mechanism may be related to its action on the STAT3/SKP2 pathway.

Scutellariae Barbatae Herba Extract Promotes Cycle Arrest of Nasopharyngeal Carcinoma Cells by Inhibiting STAT3/SKP2 Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the effect of Scutellariae Barbatae Herba extract on on the cycle arrest of nasopharyngeal carcinoma cells and the possible mechanism by adding different concentration of Scutellariae Barbatae Herba extract （0.25， 0.5， 1 g·L-1） in the culture medium， taking CNE1 （nasopharyngeal carcinoma cells） as the research object. MethodAfter the treatment of CNE1 by Scutellariae Barbatae Herba extract， cell counting kit-8 （CCK-8） was used to detect cell proliferation， and Giemsa staining was used to detect the clone formation rate. Flow cytometry was used to detect cell cycle distribution， and reverse transcription-polymerase chain reaction （ RT-PCR） assay and Western blot assay were used to detect the relative expression of messenger ribonucleic acid （mRNA） by small interfering RNA （siRNA） or overexpression. ResultAs compared with the blank group， the proliferation and colony formation rate of CNE1 in the Scutellariae Barbatae Herba extract group significantly decreased （P<0.05， P<0.01） in a dose and time-dependent manner， whereas the percentage of cells in the presynthetic phase （G0/G1） increased （P<0.05， P<0.01）. The expression level of S-phase kinase associated protein 2 （SKP2） in the Scutellariae Barbatae Herba extract group significantly decreased （P<0.01） as compared with the blank group. As compared with the Scutellariae Barbatae Herba extract group， the protein levels of p21 and p27 significantly decreased in the overexpressed SKP2+ Scutellariae Barbatae Herba extract group （P<0.01）. As compared with the blank group， the signal activation and the phosphorylation level of signal transducer and activator of transcription 3 （STAT3） of CNE1 in the S. barbata extract group significantly decreased （P<0.05， P<0.01）. ConclusionScutellariae Barbatae Herba extract effectively inhibits the proliferation of CNE1， and the mechanism may be related to its action on the STAT3/SKP2 pathway.

Apoptosis-inducing activity of synthetic hydrocarbon-stapled peptides in H358 cancer cells expressing KRAS

Lung cancers are the leading cause of cancer deaths worldwide and pose a grave threat to human life and health. Non-small cell lung cancer (NSCLC) is the most frequent malignancy occupying 80% of all lung cancer subtypes. Except for other mutations (

DNA damage repair and cell cycle arrest / 国际生物医学工程杂志

In the face of DNA damage caused by various factors, cells have a set of response and repair mechanisms. Cell cycle arrest plays an important role in the DNA damage repair, which provides enough time for repairing damaged DNA. Research on cell cycle regulation focuses on cyclin-dependent protein kinases (CDKs) and cell cycle checkpoints. In the process of DNA damage repair, phosphatidylinositol-3-kinase like kinases (PIKKs) which are recruited to the DNA damage sites can activate cell cycle checkpoint-related proteins to halt cell cycle. In the common DNA damage repair pathways, such as base excision repair (BER), nucleotide excision repair (NER) , mismatch repair (MMR) , and DNA double-strand break repair, the recruitment of repair-related proteins also plays a role in the cell cycle regulation. In this paper, the relationship between the main forms of DNA damage repair and cell cycle arrest and relevant research progress were reviewed.

Apoptotic and cytostatic actions of maslinic acid in colorectal cancer cells through possible IKK-β inhibition

Objective: To explore the anti-cancer activity of maslinic acid against colorectal cancer (CRC) cell lines and its possible mechanism. Methods: The inhibitory effect of maslinic acid was screened against five CRC cell lines (HT-29, HCT 116, SW480, SW48, and LS 174T) via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis and cell cycle analyses were carried out using annexin Ⅴ-FITC/propidium iodide staining and propidium iodide staining, respectively and subjected to fluorescence-activated cell sorting analysis. Protein expression studies of inhibitor of κB kinase-β (IKK-β), checkpoint kinase 1 (Chk1) and cyclin D1 were conducted using the JESS system. Results: Maslinic acid exhibited growth inhibitory effect in a dose- and time-dependent manner in HT-29 and HCT 116 cell lines. A more prominent apoptosis induced by maslinic acid was observed in HCT 116 cell line. However, in HT-29 cell line, maslinic acid induced cell cycle arrest by inhibiting the G1-S transition, which was accompanied by the downregulation of cyclin D1. The expression of unphosphorylated IKK-β protein was increased in both (HT-29 and HCT 116) cell lines after maslinic acid treatment. Conclusions: Maslinic acid inhibits the growth of HT-29 and HCT 116 cells in a different manner, induces cell cycle arrest in HT-29 cells and causes apoptosis in HCT 116 cells partially via NF-κB pathway inhibition.

Apoptotic and cytostatic actions of maslinic acid in colorectal cancer cells through possible IKK-β inhibition

Objective: To explore the anti-cancer activity of maslinic acid against colorectal cancer (CRC) cell lines and its possible mechanism. Methods: The inhibitory effect of maslinic acid was screened against five CRC cell lines (HT-29, HCT 116, SW480, SW48, and LS 174T) via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis and cell cycle analyses were carried out using annexin V-FITC/propidium iodide staining and propidium iodide staining, respectively and subjected to fluorescence-activated cell sorting analysis. Protein expression studies of inhibitor of κB kinase-β (IKK-β), checkpoint kinase 1 (Chk1) and cyclin D1 were conducted using the JESS system. Results: Maslinic acid exhibited growth inhibitory effect in a doseand time-dependent manner in HT-29 and HCT 116 cell lines. A more prominent apoptosis induced by maslinic acid was observed in HCT 116 cell line. However, in HT-29 cell line, maslinic acid induced cell cycle arrest by inhibiting the G1-S transition, which was accompanied by the downregulation of cyclin D1. The expression of unphosphorylated IKK-β protein was increased in both (HT-29 and HCT 116) cell lines after maslinic acid treatment. Conclusions: Maslinic acid inhibits the growth of HT-29 and HCT 116 cells in a different manner, induces cell cycle arrest in HT-29 cells and causes apoptosis in HCT 116 cells partially via NF-κB pathway inhibition.

Rational drug design, synthesis, and biological evaluation of novel chiral tetrahydronaphthalene-fused spirooxindole as MDM2-CDK4 dual inhibitor against glioblastoma

Simultaneous inhibition of MDM2 and CDK4 may be an effective treatment against glioblastoma. A collection of chiral spirocyclic tetrahydronaphthalene (THN)-oxindole hybrids for this purpose have been developed. Appropriate stereochemistry in THN-fused spirooxindole compounds is key to their inhibitory activity: selectivity differed by over 40-fold between the least and most potent stereoisomers in time-resolved FRET and KINOMEscan® assays. Studies in glioblastoma cell lines showed that the most active compound induced apoptosis and cell cycle arrest by interfering with MDM2 -P53 interaction and CDK4 activation. Cells treated with showed up-regulation of proteins involved in P53 and cell cycle pathways. The compound showed good anti-tumor efficacy against glioblastoma xenografts in mice. These results suggested that rational design, asymmetric synthesis and biological evaluation of novel tetrahydronaphthalene fused spirooxindoles could generate promising MDM2-CDK4 dual inhibitors in glioblastoma therapy.

Carfilzomib inhibits the growth of lung adenocarcinoma via upregulation of Gadd45a expression / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Proteasome inhibitors have shown remarkable success in the treatment of hematologic neoplasm. There has been a lot of attention to applying these drugs for solid tumor treatment. Recent preclinical study has signified the effectiveness on cell proliferation inhibition in lung adenocarcinoma treated by carfilzomib (CFZ), a second generation proteasome inhibitor. However, no insight has been gained regarding the mechanism. In this study, we have systematically investigated the CFZ functions in cell proliferation and growth, cell cycle arrest, and apoptosis in lung adenocarcinoma cells. Flow cytometry experiments showed that CFZ significantly induced G2/M cell cycle arrest and apoptosis in lung adenocarcinoma. MTS and colony formation assays revealed that CFZ substantially inhibited survival of lung adenocarcinoma cells. All results were consistently correlated to the upregulation expression of Gadd45a, which is an important gene in modulating cell cycle arrest and apoptosis in response to physiologic and environmental stresses. Here, upregulation of Gadd45a expression was observed after CFZ treatment. Knocking down Gadd45a expression suppressed G2/M arrest and apoptosis in CFZ-treated cells, and reduced cytotoxicity of this drug. The protein expression analysis has further identified that the AKT/FOXO3a pathway is involved in Gadd45a upregulation after CFZ treatment. These findings unveil a novel mechanism of proteasome inhibitor in anti-solid tumor activity, and shed light on novel preferable therapeutic strategy for lung adenocarcinoma. We believe that Gadd45a expression can be a highly promising candidate predictor in evaluating the efficacy of proteasome inhibitors in solid tumor therapy.

Synergistic antitumor effects and mechanism of apigenin and tanshinone ⅡA / 中草药

Objective: To evaluate the synergistic anticancer effects of the combination of apigenin (Api) and tanshinone Ⅱ A (Tan IIA), and investigate the mechanisms of pharmacological effects and their potential applications as an anticancer therapy in clinics. Methods: MTT assay were used to determine anticancer effects of the combination of Api and Tan ⅡA on BGC823, MCF7, and SMMC7721 cells. AV-PI dual stain and PI staining method were used for detecting the effect of the two drugs combination on BGC823 cell apoptosis and cell cycle. Expression of p53, BAX/BCL-2, cyclin B1 and D1 proteins were determined by Western blotting. Circular dichroism method and DNA melting point method were explored to detect interaction among the two drugs and DNA. S180 tumor xenograft mice model was used to evaluate the antitumor effects of the two drugs combination. Results: Tan IIA combined with Api exerted synergistic inhibitory effects on the proliferation of BGC823 and other tumor cells with the CI of 0.28. After tumor cell treated by combination of Tan IIA and Api, the tumor cell apoptosis was significantly enhanced and the value of BAX/BCL-2 in cells was up-regulated (P < 0.01); The levels of cyclin B1, D1 protein were changed and cell cycle arrest was increased which mainly blocked in S phase. The interaction among the two drugs and DNA was in two different ways, leading to the curves of thermal denaturation of DNA changed significantly. Furthermore, the combination of Tan IIA and Api showed a stronger inhibitory effect on tumor volume and weight in S180 mice model than monotherapy, which was similar to cyclophosphamide therapy but less side effects. Conclusion Tan IIA combined with Api exerted synergistic antitumor effects. The two drugs interacted with DNA in different ways and aggravated the cell cycle arrest, which were the key mechanisms of their synergistic antitumor effects.

In vitro antitumor effect of cucurbitacin E on human lung cancer cell line and its molecular mechanism / 中国天然药物

Cucurbitacin E (CuE) is previously reported to exhibit antitumor effect by several means. In this study, CuE acted as a tyrosine kinase inhibitor interfering with the epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK) signaling pathway and subsequently induced apoptosis and cell cycle arrest in non-small-cell lung cancer (NSCLC) cell line A549. The apoptosis regulators, cleaved Caspases-3 and Caspases-9, were observed to be increased with the treatment of CuE. The activated transcription factor STAT3 and the apoptosis inhibitor protein survivin were also observed to be reduced. The cell cycle regulators, CyclinA2, cylinB1, CyclinD1 and CyclinE, were also investigated and the results suggested that the cell cycle was arrested at G1/G0 phase. Treatment of CuE also altered the existence status of most of the participants in the EGFR/MAPK signaling. Phosphorylation of EGFR enhanced significantly, leading to the alteration of members downstream, either total amount or phosphorylation level, notably, MEK1/2 and ERK1/2. Moreover, the results of molecular simulation brought an insight on the interaction mechanism between CuE and EGFR. In summary, CuE exhibited anti-proliferative effect against A549 cells by targeting the EGFR/MAPK signaling pathway.

Effects of salinomycin on proliferation and apoptosis of oral squamous cell carcinoma / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effects of salinomycin on the proliferation and apoptosis of oral squamous carcinoma cells and to further understand the mechanisms of these effects.@*METHODS@#The human oral squamous carcinoma cell line CAL-27 was cultured in different concentrations of salinomycin and cisplatin. After co-culture with 0, 1, 2, 4, 8, 16 and 32 μmol/L salinomycin or 0, 1.25, 2.5, 5, 10, 20, 40 and 80 μmol/L cisplatin for 24 hours and 48 hours, the proliferation of oral squamous carcinoma cells were detected by cell counting kit-8(CCK-8) assay. After being exposed to 0, 2, 4, 8 μmol/L salinomycin and 0, 5, 10, 20 μmol/L cisplatin for 48 hours, the cell cycle of oral squamous carcinoma cells was detected by flow cytometry assay, and Western blot analysis was performed to analyze the expressions of cysteine-containing aspartate-specific proteases-3(Caspase-3), cysteine-containing aspartate-specific proteases-9(Caspase-9), poly ADP-ribose polymerase (PARP), protein kinase B (Akt) and phosphorylated protein kinase B (p-Akt) protein in oral squamous carcinoma cells.@*RESULTS@#Both salinomycin and cisplatin significantly inhibited the proliferation of oral squamous cell carcinoma CAL-27 cells in a time- and dose-dependent manner. However, compared with the first-line chemotherapeutic drug cisplatin, salinomycin showed stronger anti-proliferation activity in oral squamous carcinoma cells than cisp-latin (P < 0.001). After being exposed to 8 μmol/L salinomycin, CAL-27 cells exhibited markedly higher proportion in quiescent/ first gap phases (40.40%±1.99% vs. 64.46%±0.90%, P < 0.05), and had a significantly lower proportion in synthesis phases and second gap / mitosis phases (24.32%±2.30% vs. 18.73%±0.61%, P < 0.05; 35.01%±1.24% vs. 16.54%±1.31%, P < 0.05) compared with the dimethyl sulfoxide control group; moreover cisplatin didn't show cell-cycle specific effect on CAL-27. Western blot proved that salinomycin could up-regulate the expressions of Caspase-3 and Caspase-9 protein in oral squamous cell carcinoma CAL-27 cells (P < 0.05). At the same time, the levels of PARP, Akt and p-Akt protein were down-regulated (P < 0.05).@*CONCLUSION@#Compared with cisplatin, salinomycin has a better inhibitory effect on the proliferation of oral squamous carcinoma cells and blocks the cell cycle process at the quiescent / first gap phase. At the same time, salinomycin could trigger apoptosis of oral squamous carcinoma cells and the mechanism is associated with the Akt/p-Akt signaling pathway.

Gramicidin inhibits human gastric cancer cell proliferation, cell cycle and induced apoptosis

BACKGROUND: Gastric cancer is a common malignant tumor with high morbidity and mortality worldwide, which seriously affects human health. Gramicidin is a short peptide antibiotic which could be used for treating infection induced by bacteria or fungi. However, the anti-cancer effect of gramicidin on gastric cancer cells and its underlying mechanism remains largely unknown. RESULTS: Gastric cancer cells SGC-7901, BGC-823 and normal gastric mucosal cells GES-1 were treated with different concentrations of gramicidin respectively. The results of CCK-8 experiment revealed cellular toxicity of gramicidin to cancer cells while cell colony formation assay showed that gramicidin significantly inhibited the proliferation of gastric cancer cells, but had little effect on normal gastric mucosal cells. In addition, the wound healing assay showed that gramicidin inhibited the migration of SGC-7901 cell. Meanwhile, apoptosis and cell cycle analysis revealed that gramicidin induced cell apoptosis with G2/M cell cycle inhibition. Furthermore, western blot analysis demonstrated that gramicidin down-regulated the expression of cyclinD1 and Bcl-2 as well as the FoxO1 phosphorylation. CONCLUSIONS: The current study illustrated the anti-tumor activity of gramicidin on gastric cancer cells, providing a possibility for gramicidin to be applied in clinical practice for the treatment of gastric cancer.

Bleomycin Inhibits Proliferation via Schlafen-Mediated Cell Cycle Arrest in Mouse Alveolar Epithelial Cells / 결핵

BACKGROUND: Idiopathic pulmonary fibrosis involves irreversible alveolar destruction. Although alveolar epithelial type II cells are key functional participants within the lung parenchyma, how epithelial cells are affected upon bleomycin (BLM) exposure remains unknown. In this study, we determined whether BLM could induce cell cycle arrest via regulation of Schlafen (SLFN) family genes, a group of cell cycle regulators known to mediate growth-inhibitory responses and apoptosis in alveolar epithelial type II cells. METHODS: Mouse AE II cell line MLE-12 were exposed to 1–10 µg/mL BLM and 0.01–100 µM baicalein (Bai), a G1/G2 cell cycle inhibitor, for 24 hours. Cell viability and levels of pro-inflammatory cytokines were analyzed by MTT and enzyme-linked immunosorbent assay, respectively. Apoptosis-related gene expression was evaluated by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Cellular morphology was determined after DAPI and Hoechst 33258 staining. To verify cell cycle arrest, propidium iodide (PI) staining was performed for MLE-12 after exposure to BLM. RESULTS: BLM decreased the proliferation of MLE-12 cells. However, it significantly increased expression levels of interleukin 6, tumor necrosis factor α, and transforming growth factor β1. Based on Hoechst 33258 staining, BLM induced condensation of nuclear and fragmentation. Based on DAPI and PI staining, BLM significantly increased the size of nuclei and induced G2/M phase cell cycle arrest. Results of qRT-PCR analysis revealed that BLM increased mRNA levels of BAX but decreased those of Bcl2. In addition, BLM/Bai increased mRNA levels of p53, p21, SLFN1, 2, 4 of Schlafen family. CONCLUSION: BLM exposure affects pulmonary epithelial type II cells, resulting in decreased proliferation possibly through apoptotic and cell cycle arrest associated signaling.

Mesenchymal stem cells in acute myeloid leukemia: a focus on mechanisms involved and therapeutic concepts

Drug resistance in cancer, especially in leukemia, creates a dilemma in treatment planning. Consequently, studies related to the mechanisms underlying drug resistance, the molecular pathways involved in this phenomenon, and alternate therapies have attracted the attention of researchers. Among a variety of therapeutic modalities, mesenchymal stem cells (MSCs) are of special interest due to their potential clinical use. Therapies involving MSCs are showing increasing promise in cancer treatment and anticancer drug screening applications; however, results have been inconclusive, possibly due to the heterogeneity of MSC populations. Most recently, the effect of MSCs on different types of cancer, such as hematologic malignancies, their mechanisms, sources of MSCs, and its advantages and disadvantages have been discussed. There are many proposed mechanisms describing the effects of MSCs in hematologic malignancies; however, the most commonly-accepted mechanism is that MSCs induce tumor cell cycle arrest. This review explains the anti-tumorigenic effects of MSCs through the suppression of tumor cell proliferation in hematological malignancies, especially in acute myeloid leukemia.