Mechanism Of Growth Inhibition Research Articles

UM171 cooperates with PIM1 inhibitors to restrict HSC expansion markers and suppress leukemia progression

The pyrimido-indole derivative UM171 promotes human Hematopoietic Stem Cells Expansion (HSCE), but its impact on leukemia is not known. Herein, we show in a mouse model of erythroleukemia that UM171 strongly suppresses leukemia progression. UM171 inhibits cell cycle progression and apoptosis of leukemic cells in culture. The effect of UM171 on leukemia differentiation was accompanied by increased expression of HSCE markers. RNAseq analysis combined with Q-RT-PCR and western blotting revealed that the PIM1 protein kinase is highly elevated in response to UM171 treatment. Moreover, docking analysis combined with immunoprecipitation assays revealed high binding affinity of UM171 to PIM1. Interestingly, pan-PIM kinase inhibitors counteracted the effect of UM171 on HSCE marker expression and PIM1 transcription, but not its suppression of leukemic cell growth. Moreover, combination treatment with UM171 and a pan-PIM inhibitor further suppressed leukemic cell proliferation compared to each drug alone. To uncover the mechanism of growth inhibition, we showed strong upregulation of the cyclin-dependent kinase inhibitor P21CIP1 and the transcription factor KLF2 by UM171. In accordance, KLF2 knockdown attenuated growth inhibition by UM171. KLF2 upregulation by UM171 is also responsible for the activation of P21CIP1 in leukemic cells leading to a G1/S arrest and suppression of leukemogenesis. Thus, suppression of leukemic growth by UM171 through KLF2 and P21CIP1 is thwarted by PIM-mediated expansion of leukemic stemness, uncovering a novel therapeutic modality involving combined UM171 plus PIM inhibitors.

Neutrophils as immune effector cells in antibody therapy in cancer.

Tumor-targeting monoclonal antibodies are available for a number of cancer cell types (over)expressing the corresponding tumor antigens. Such antibodies can limit tumor progression by different mechanisms, including direct growth inhibition and immune-mediated mechanisms, in particular complement-dependent cytotoxicity, antibody-dependent cellular phagocytosis, and antibody-dependent cellular cytotoxicity (ADCC). ADCC can be mediated by various types of immune cells, including neutrophils, the most abundant leukocyte in circulation. Neutrophils express a number of Fc receptors, including Fcγ- and Fcα-receptors, and can therefore kill tumor cells opsonized with either IgG or IgA antibodies. In recent years, important insights have been obtained with respect to the mechanism(s) by which neutrophils engage and kill antibody-opsonized cancer cells and these findings are reviewed here. In addition, we consider a number of additional ways in which neutrophils may affect cancer progression, in particular by regulating adaptive anti-cancer immunity.

The Effective Analysis for Blue Honeysuckle Extract in the Treatment of Hepatocellular Carcinoma.

To further determine how BHE affected the growth of HCC cells, the proportion of each cell cycle phase was explored in HCC cells by flow cytometry. Blue honeysuckle (Lonicera caerulea L.) is a species of bush that grows in eastern Russia. Blue honeysuckle extract (BHE) is rich in bioactive phytochemicals which can inhibit the proliferation of tumor cells. The mechanism underlying the anticancer activity of BHE in primary liver cancer is poorly understood. The purpose of this study was to evaluate the growth inhibition mechanism of bioactive substances from blue honeysuckle on hepatocellular carcinoma (HCC) cells and to explore its protein and gene targets. The compounds in BHE were determined by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). Cell counting kit-8 (CCK8) assay was used to evaluate the effects of BHE on HCC cell proliferation, and flow cytometry assay (FCA) was used to determine how BHE arrested the proportion of each cell cycle phase in HCC cells. Western blot (WB) was performed to determine the expression of cell cycle-related proteins in HCC cells treated with different concentrations of BHE. The xenograft tumor animal models were established by HCC cell implantation. The results showed that cyanidin-3-o-glucoside and cyanidin-3-o-sophoroside which are the main biologically active components were detected in BHE. BHE is highly effective in inhibiting the proliferation of HCC cells by arresting the HCC cell cycle in the G2/M phase. BHE also downregulated the expression of conventional or classical dendritic cells-2 (cDC2) and cyclin B1 by promoting the expression of myelin transcription factor 1 (MyT1) in HCC cells. The weight and volume of xenografts were significantly decreased in the BHE treated groups when compared to the control group. BHE increased the expression of MyT1 in xenograft tissues. These findings showed that blue honeysuckle extract inhibits proliferation in vivo and in vitro by downregulating the expression of cDC2 and cyclin B1 and upregulating the expression of MyT1 in HCC cells.

Synergistic effects of carbon cycle metabolism and photosynthesis in Chinese cabbage under salt stress

Chinese cabbage (Brassica rapa ssp. pekinensis) has a long cultivation history and is one of the vegetable crops with the largest cultivation area in China. However, salt stress severely damages photosynthesis and hormone metabolism, nutritional balances, and results in ion toxicity in plants. To better understand the mechanisms of salt-induced growth inhibition in Chinese cabbage, RNA-seq and physiological index determination were conducted to explore the impacts of salt stress on carbon cycle metabolism and photosynthesis in Chinese cabbage. Here, we found that the number of thylakoids and grana lamellae and the content of starch granules and chlorophyll in the leaves of Chinese cabbage under salt stress showed a time-dependent response, first increasing and then decreasing. Chinese cabbage increased the transcript levels of genes related to the photosynthetic apparatus and carbon metabolism under salt stress, probably in an attempt to alleviate damage to the photosynthetic system and enhance CO2 fixation and energy metabolism. The transcription of genes related to starch and sucrose synthesis and degradation were also enhanced; this might have been an attempt to maintain intracellular osmotic pressure by increasing soluble sugar concentrations. Soluble sugars could also be used as potential reactive oxygen species (ROS) scavengers, in concert with peroxidase (POD) enzymes, to eliminate ROS that accumulate during metabolic processes. Our study characterizes the synergistic response network of carbon metabolism and photosynthesis under salt stress.

Arbidol inhibits human esophageal squamous cell carcinoma growth in vitro and in vivo through suppressing ataxia telangiectasia and Rad3-related protein kinase.

Human esophageal cancer has a global impact on human health due to its high incidence and mortality. Therefore, there is an urgent need to develop new drugs to treat or prevent the prominent pathological subtype of esophageal cancer, esophageal squamous cell carcinoma (ESCC). Based upon the screening of drugs approved by the Food and Drug Administration, we discovered that Arbidol could effectively inhibit the proliferation of human ESCC in vitro. Next, we conducted a series of cell-based assays and found that Arbidol treatment inhibited the proliferation and colony formation ability of ESCC cells and promoted G1-phase cell cycle arrest. Phosphoproteomics experiments, in vitro kinase assays and pull-down assays were subsequently performed in order to identify the underlying growth inhibitory mechanism. We verified that Arbidol is a potential ataxia telangiectasia and Rad3-related (ATR) inhibitor via binding to ATR kinase to reduce the phosphorylation and activation of minichromosome maintenance protein 2 at Ser108. Finally, we demonstrated Arbidol had the inhibitory effect of ESCC in vivo by a patient-derived xenograft model. All together, Arbidol inhibits the proliferation of ESCC in vitro and in vivo through the DNA replication pathway and is associated with the cell cycle.

P10.20.A Mechanisms of synergistic glioma growth suppression by radiotherapy and MET inhibition

Abstract Background Glioblastoma remains to be one of the most lethal solid cancers. Despite multi-modal therapy including surgery as safely feasible, radiotherapy and chemotherapy with the alkylating agent temozolomide, the median survival of affected patients is still limited to approximately one year on a population level. Thus, novel therapies are urgently needed. There is increasing interest in the role of the HGF/MET pathway in the response of glioblastoma to radiotherapy since MET may be involved in radioresistance via proinvasive and DNA damage response pathways. Material and Methods Here we assessed the role of the MET pathway in the response to radiotherapy in vitro and in vivo in syngeneic mouse glioma models and explored potential modes of action responsible for the synergistic effects of MET pathway inhibition and irradiation on tumor growth in vivo. Results Murine glioma cells express HGF and MET and show increased MET phosphorylation upon exposure to exogenous HGF. In vitro, glioma cell viability and proliferation are not affected by pharmacological MET inhibition using tepotinib or genetic MET inhibition using CRISPR/Cas9-engineered Met gene knockout and sensitization to irradiation by MET inhibition is not seen. In vivo, the combination of MET inhibition with focal radiotherapy mediates prolonged survival of syngeneic orthotopic glioma-bearing mice compared with either treatment alone. Complementary studies demonstrate that synergy is lost when gliomas are established and treated in immunodeficient mice, but also if MET gene expression is disrupted in the tumor of wildtype mice. Combination therapy suppresses a set of pro-inflammatory mediators that are upregulated by radiotherapy alone and which are positively regulated by transforming growth factor (TGF)-β. In line with this data, ex vivo analysis of mouse brains reveal increased TGF-β pathway activity upon irradiation alone that is counteracted by concomitant MET inhibition. Conclusion In summary, we demonstrate synergistic suppression of syngeneic glioma growth by irradiation and MET inhibition that requires MET expression in the tumor as well as an intact immune system. Clinical evaluation of this combined treatment approach in newly diagnosed glioblastoma is warranted.

Chlorpromazine cooperatively induces apoptosis with tyrosine kinase inhibitors in EGFR-mutated lung cancer cell lines and restores the sensitivity to gefitinib in T790M-harboring resistant cells

We previously reported that the antipsychotic drug chlorpromazine (CPZ), which inhibits the formation of clathrin-coated vesicles (CCVs) essential for endocytosis and intracellular transport of receptor tyrosine kinase (RTK), inhibits the growth/survival of acute myeloid leukemia cells with mutated RTK (KIT D816V or FLT3-ITD) by perturbing the intracellular localization of these molecules. Here, we examined whether these findings are applicable to epidermal growth factor receptor (EGFR). CPZ dose-dependently inhibited the growth/survival of the non-small cell lung cancer (NSCLC) cell line, PC9 harboring an EGFR-activating (EGFR exon 19 deletion). In addition, CPZ not only suppressed the growth/survival of gefitinib (GEF)-resistant PC9ZD cells harboring T790 M, but also restored their sensitivities to GEF. Furthermore, CPZ overcame GEF resistance caused by Met amplification in HCC827GR cells. As for the mechanism of CPZ-induced growth suppression, we found that although CPZ hardly influenced the phosphorylation of EGFR, it effectively reduced the phosphorylation of ERK and AKT. When utilized in combination with trametinib (a MEK inhibitor), dabrafenib (an RAF inhibitor), and everolimus (an mTOR inhibitor), CPZ suppressed the growth of PC9ZD cells cooperatively with everolimus but not with trametinib or dabrafenib. Immunofluorescent staining revealed that EGFR shows a perinuclear pattern and was intensely colocalized with the late endosome marker, Rab11. However, after CPZ treatment, EGFR was unevenly distributed in the cells, and colocalization with the early endosome marker Rab5 and EEA1 became more apparent, indicating that CPZ disrupted the intracellular transport of EGFR. These results suggest that CPZ has therapeutic potential for NSCLC with mutated EGFR by a novel mechanism different from conventional TKIs alone or in combination with other agents.

Phytochemical-rich Fractions from Foxtail Millet (Setaria italica (L.) P. Beauv) Seeds Exhibited Antioxidant Activity and Reduced the Viability of Breast Cancer Cells In Vitro by Inducing DNA Fragmentation and Promoting Cell Cycle Arrest.

The demand for millet-based diets has increased significantly in recent years due to their beneficial effects on human health. Foxtail Millet (Setaria italica (L.) P. Beauv, previously known as Panicum italicum L., referred as FTM in this manuscript) seeds have been not only used as astringent and diuretic agents, but they are also used to treat dyspepsia and rheumatism. Recent studies have shown that solvent extracts from FTM seeds exhibited antioxidant and antiinflammatory activities. However, the nature and antiproliferative potential of phytochemical constituents of solvent extracts are not much explored. Major objectives of this study are to generate and characterize the phytochemical-rich fractions from Foxtail millet seeds, test the antioxidant activity, and antiproliferative potential against cell lines representing carcinomas of the breast, and determine the mechanisms of cell growth inhibition. Phytochemical-rich fractions were generated by extracting the seeds using 70% ethanol (FTM-FP) and 10% alkali (FTM-BP). Antioxidant potential was determined by ferric reducing antioxidant power (FRAP) assay and DPPH radical scavenging activity assays. The antiproliferative potential was determined using sulforhodamine-B assay. The impact on cell cycle and DNA fragmentation was analyzed by staining the cells with DAPI followed by analyzing the stained cells using NC-3000. Analysis of the results showed the presence of phenolics and flavonoids in the FTM-FP and FTM-BP fractions. Both fractions exhibited antiproliferative potential against breast cancer cell lines. Mechanistically, both fractions induced G2/M cell cycle arrest and increased the fragmentation of DNA, which lead to the accumulation of cells in the Sub-G1 phase. In summary, results of this study demonstrated the potential of foxtail millet phytochemical fractions for retarding the proliferative potential of breast cancer cells.

Effects of Different Nutritional Zinc Forms on the Proliferation of Beneficial Commensal Microorganisms

This study compared the minimal inhibition concentrations (MICs) and their effects on the growth kinetics of seven different types of zinc (Zn) compounds and Na2EDTA in the case of three typical commensal beneficial microorganisms (Bacillus subtilis, Lactococcus lactis, and Saccharomyces cerevisiae). The seven Zn compounds included ZnSO4, four Zn–amino acid chelates, and two Zn–EDTA complexes. Both MICs and growth kinetic parameters indicated that different microorganisms show different sensitivities; for example, B. subtilis, L. lactis, and S. cerevisiae were most sensitive to ZnSO4, Na2EDTA, and Zn(NH3)2(Gly)2, respectively. Both ZnEDTA and Zn(NH3)2(Lys)2 improved the growth rate of all beneficial commensal intestinal microorganisms at low concentrations (5–10 mg/L) and showed low toxicity towards all tested strains. At higher concentrations (100–500 mg/L), all compounds decreased the growth rate and increased the lag phase. In conclusion, both growth kinetic parameters and MICs tested effectively measured the inhibitory effects of the test materials; however, growth kinetics provides a more detailed picture of the concentration-dependent effects and those on the mechanisms of microbial growth inhibition.

WASH regulates the oxidative stress Nrf2/ARE pathway to inhibit proliferation and promote apoptosis of HeLa cells under the action of Jolkinolide B.

Jolkinolide B (JB), a diterpenoid compound isolated from the roots of Euphorbia fischeriana, has gained research attention for its antitumor effects. In recent years, JB reportedly displayed anti-tumor activity in solid tumors, such as breast, ovarian, and prostate cancer, and leukemia. In this study, we evaluated the effect of JB on HeLa cells with a focus on cell growth inhibition and related mechanisms. HeLa cells were cultured in vitro and divided into a blank control group, HeLa-Scramble (0, 0.25, 0.5 mM), and Wiskott-Aldrich syndrome protein and SCAR homolog (WASH) protein silenced group, HeLa-shWASH (0, 0.25, 0.5 mM). Morphological changes were observed using an inverted microscope. The inhibition rate of cell proliferation was detected using the WST-1 method. Flow cytometry Brdu+PI double standard method was used to detect cell replication ability and FITC+PI double standard method was used to detect cell apoptosis rate. Western blot was used to verify the expression of Nrf2, HO-1, WASH, Bax, Bcl-2, and PCNA. The mRNA expression of cytokines (IL-1α, IL-6, and IL-8) was detected using RT-qPCR. The results showed that JB induced cell apoptosis and arrested cells at the G2/M phase in HeLa-shWASH cells compared with HeLa-Scramble cells (P < 0.05, P < 0.01, respectively). In addition, JB upregulated IL-1α, IL-6, and IL-8 in HeLa-shWASH cells. We conclude that WASH protein participates in JB-induced regulation of the Nrf2/ARE pathway, aggravates inflammatory responses, and promotes cancer cell apoptosis, thus inhibiting the proliferation and invasion abilities of HeLa cells. JB may have anti-tumor effects and potential clinical value for the treatment of cervical cancer.

A Quassinoid Diterpenoid Eurycomanone from Eurycoma longifolia Jack Exerts Anti-Cancer Effect through Autophagy Inhibition

Eurycomanone (EN) is one of the representative quassinoid diterpenoids from roots of Eurycoma longifolia Jack, a natural medicine that is widely distributed in Southeast Asia. Previous studies showed that EN induces cancer cell apoptosis and exhibits anti-cancer activity, but the molecular mechanism of EN against cancer has still not been elucidated. In this study, we examined the regulatory effect of EN on autophagy to reveal the mechanism of EN-mediated colon cancer growth inhibition. First, we found that EN is able to inhibit colon cancer cell proliferation and colony formation. The angiogenesis level in cancer cells was inhibited as well. Next, the treatment of EN led to the suppression of autophagy, which was characterized by the downregulation of the LC3-II level and the formation of GFP-LC3 puncta under EN treatment in colon cancer. Moreover, we revealed that the mTOR signaling pathway was activated by EN in a time- and concentration-dependent manner. Finally, autophagy induction protected colon cancer cells from EN treatment, suggesting that autophagy improves cell survival. Taken together, our findings revealed the mechanism of EN against colon cancer through inhibiting autophagy and angiogenesis in colon cancer, supporting that the autophagy inhibitor EN could be developed to be a novel anti-cancer agent.

High Glucose Induces in HK2 Kidney Cells an IFN-Dependent ZIKV Antiviral Status Fueled by Viperin.

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that rapidly became a major medical concern worldwide. We have recently reported that a high glucose level decreases the rate of Zika virus (ZIKV) replication with an impact on human kidney HK-2 cell survival. However, the mechanisms by which cells cultured in a high glucose medium inhibit ZIKV growth remain unclear. Viperin belongs to interferon-stimulated genes (ISG) and its expression is highly up-regulated upon viral infection, leading to antiviral activity against a variety of viruses, including flaviviruses. As such, viperin has been shown to be a major actor involved in the innate immune response against Zika virus (ZIKV). Our present study aims to further characterize the involvement of viperin in ZIKV growth inhibition under high glucose concentration (HK-2HGC). We show for the first time that endogenous viperin is over-expressed in HK-2 cells cultured under high glucose concentration (HK-2HGC), which is associated with ZIKV growth inhibition. Viperin knockdown in HK-2HGC rescues ZIKV growth. In addition, our results emphasize that up-regulated viperin in HK-2HGC leads to ZIKV growth inhibition through the stimulation of IFN-β production. In summary, our work provides new insights into the ZIKV growth inhibition mechanism observed in HK-2 cells cultured in a high glucose environment.

Exposure of Candida parapsilosis to the silver(I) compound SBC3 induces alterations in the proteome and reduced virulence.

The antimicrobial properties of silver have been exploited for many centuries and continue to gain interest in the fight against antimicrobial drug resistance. The broad-spectrum activity and low toxicity of silver have led to its incorporation into a wide range of novel antimicrobial agents, including N-heterocyclic carbene (NHC) complexes. The antimicrobial activity and in vivo efficacy of the NHC silver(I) acetate complex SBC3, derived from 1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene (NHC*), have previously been demonstrated, although the mode(s) of action of SBC3 remains to be fully elucidated. Label-free quantitative proteomics was applied to analyse changes in protein abundance in the pathogenic yeast Candida parapsilosis in response to SBC3 treatment. An increased abundance of proteins associated with detoxification and drug efflux were indicative of a cell stress response, whilst significant decreases in proteins required for protein and amino acid biosynthesis offer potential insight into the growth-inhibitory mechanisms of SBC3. Guided by the proteomic findings and the prolific biofilm and adherence capabilities of C. parapsilosis, our studies have shown the potential of SBC3 in reducing adherence to epithelial cells and biofilm formation and hence decrease fungal virulence.

Selection and characterization of plant-derived alkaloids with strong antialgal inhibition: growth inhibition selectivity and inhibitory mechanism

In recent years, researches on microalgae inhibition with plant-derived active substances have attracted much attention. In this study, the inhibition of six plant-derived alkaloids (neferine, isoliensinine, linensinine, nuciferine, capsaicin, and hordenine) on bloom-forming cyanobacteria Microcystis aeruginosa were investigated. The results showed that neferine and nuciferine had stronger inhibition on the growth of M. aeruginosa compared with the other four alkaloids, and the relative inhibition rate reached 91.27% and 88.70% at the concentration of 4.5 mg/L after 7 d of exposure, respectively. Different from neferine, nuciferine has no inhibition on Chlorella sp. and Tetradesmus obliquus. It also increased the diversity and species homogeneity of phytoplankton in the environmental water samples. Nuciferine decreased the contents of chlorophyll a and β-carotene in M. aeruginosa with the extension of treatment time, which was 59.40% and 31.90% of the control at the concentration of 1.04 mg/L after 48 h, respectively. After 48 h of nuciferine exposure, the values of fluorescence parameters including maximum quantum yield (Fv/Fm), actual quantum yield of PSII (Yield), non-photochemical quenching (qN and NPQ), and electron transport rates (ETR) of M. aeruginosa cells were significantly decreased and photosynthetic capacity was weakened. The superoxide dismutase (SOD), catalase (CAT), ascorbic acid (ASA), and glutathione (GSH) in the cells were significantly reduced, and the hydrogen peroxide (H2O2) and malonaldehyde (MDA) contents continued to accumulate, causing severe oxidative damage. Therefore, the good biological safety and strong specific inhibition of nuciferine makes it have great application prospects in the inhibition of cyanobacteria blooms.

Abstract 5289: Activating p53 through MDM2 and WIP1 inhibition effectively inhibits tumors in liver adenocarcinoma

Abstract Intrahepatic cholangiocarcinoma (iCCA) is an adenocarcinoma arising from the intrahepatic bile duct and accounts for the second most cases of primary liver cancers after hepatocellular carcinoma. Lacking effective treatment leads to a poor prognosis for advanced iCCA so new targeted therapy is warranted. Impaired wild-type (WT) p53 tumor suppressor function by its negative regulators frequently occurs in iCCA. Therefore, restoration of WT p53 function by inhibiting its negative regulators is a therapeutic strategy being explored for cancer treatment. Both MDM2 inhibitor (MDM2i, RG7388) stabilizing p53 and WIP1 inhibitor (WIP1i, GSK2830371) increasing p53 phosphorylation lead to maximize p53 function. The combination of MDM2i/WIP1i has been reported in severe cancer types but no in vivo study has been done. In the current study, both liver adenocarcinoma cell lines, RBE and SK-Hep-1, were treated with the RG7388 alone and in combination with GSK2830371. Cell proliferation, clonogenicity, protein and mRNA expressions, and cell cycle distribution were performed to investigate the effect and mechanism of growth suppression. To evaluate the antitumor efficacy of RG7388 and GSK2830371 in vivo, xenografts with SK-Hep-1 cells were treated with combination therapy for two weeks in NOD-SCID mice. The combination of MDM2i and WIP1i significantly increased the growth inhibition, cytotoxic activity, increased p53 protein expression, and phosphorylation (Ser 15), leading to transactivation of downstream targets (p21 and MDM2). The in vivo test demonstrated that the combination treatment can significantly inhibit tumor growth. In this study, liver adenocarcinoma cell lines were inhibited by the combination via reactivation of p53 function evidenced by increased p53 expression, phosphorylation and its downstream targets. This efficacy was also validated by in vivo study. The current research provides a novel strategy for targeting the p53 pathway in liver adenocarcinoma. Citation Format: Chiao-Ping Chen, Chun-Nan Yeh, Yi-Ru Pan, Yu-Tien Hsiao, Chih-Hong Lo, Cai-Jhen Jhuang, Chiao-En Wu. Activating p53 through MDM2 and WIP1 inhibition effectively inhibits tumors in liver adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5289.

Inhibition Effect of Ti3C2Tx MXene on Ice Crystals Combined with Laser-Mediated Heating Facilitates High-Performance Cryopreservation

The phenomena of ice formation and growth are of great importance for climate science, regenerative medicine, cryobiology, and food science. Hence, how to control ice formation and growth remains a challenge in these fields and attracts great interest from widespread researchers. Herein, the ice regulation ability of the two-dimensional MXene Ti3C2Tx in both the cooling and thawing processes is explored. Molecularly speaking, the ice growth inhibition mechanism of Ti3C2Tx MXene is ascribed to the formation of hydrogen bonds between functional groups of -O-, -OH, and -F distributed on the surface of Ti3C2Tx and ice/water molecules, which was elucidated by the molecular dynamics simulation method. In the cooling process, Ti3C2Tx can decrease the supercooling degree and inhibit the sharp edge morphology of ice crystals. Moreover, taking advantage of the outstanding photothermal conversion property of Ti3C2Tx, rapid ice melting can be achieved, thus reducing the phenomena of devitrification and ice recrystallization. Based on the ice restriction performance of Ti3C2Tx mentioned above, Ti3C2Tx is applied for cryopreservation of stem-cell-laden hydrogel constructs. The results show that Ti3C2Tx can reduce cryodamage to stem cells induced by ice injury in both the cooling and thawing processes and finally increase the cell viability from 38.4% to 80.9%. In addition, Ti3C2Tx also shows synergetic antibacterial activity under laser irradiation, thus realizing sterile cryopreservation of stem cells. Overall, this work explores the ice inhibition performance of Ti3C2Tx, elucidates the physical mechanism, and further achieves application of Ti3C2Tx in the field of cell cryopreservation.

Melatonin and andrographolide synergize to inhibit the colospheroid phenotype by targeting Wnt/beta-catenin signaling.

β-catenin signaling, and angiogenesis are associated with colospheroid (CSC), development. CSCs, spheroids derived from colon cancer cells, are responsible for metastasis, drug resistance, and disease recurrence. Whether dysregulating β-catenin and inhibiting angiogenesis reduce CSC growth is unknown. In this study, the molecular mechanism of CSC growth inhibition was evaluated using a novel combination of melatonin (MLT) and andrographolide (AGP). These drugs have anticarcinogenic, antioxidant, and antimetastatic properties. CSCs were obtained from two metastatic colon cancer cell lines (HT29 and HCT-15). The viability and stemness were monitored (FDA propidium iodide staining and immunoblot for CD44, CD133, Nanog, Sox2, and Oct4). The drug combination synergistically diminished stemness via increased reactive oxygen species (ROS) levels, reduced mitochondrial membrane potential and ATP level. MLT + AGP induced cell death by inhibiting β-catenin expression and its downregulatory signals, Cyclin D1, c-Myc. MLT + AGP treated cells exhibited translocation of phospho-β-catenin to the nucleus and dephosphorylated-β-catenin. Downregulation of β-catenin activation and its transcription factors (TCF4 and LEF1) and GTP binding/G-protein related activity were found in the dual therapy. Angiogenic inhibition is consistent with downregulation of VEGF messenger RNA transcripts (VEGF189), phosphorylated VEGF receptor protein expression, matrigel invasion, and capillary tube inhibition. In vivo, the intravenous injection of MLT + AGP slowed HT29 metastatic colon cancer. Histopathology indicated significant reduction in microvascular density and tumor index. Immunohistochemistry for caspase 7, and β-catenin found increased apoptosis and downregulation of β-catenin signals. The mechanism(s) of decreased colospheroids growth were the inhibition of the Wnt/β-catenin pathway. Our results provide a rationale for using MLT in combination with AGP for the inhibition of CRCs.

Taraxasterol prompted the anti-tumor effect in mice burden hepatocellular carcinoma by regulating T lymphocytes

Hepatocellular carcinoma (HCC) is a common digestive malignant tumor with high morbidity and mortality worldwide, however, the treatment of HCC and prognosis of patients are not optimistic, finding more effective treatments are imperative. Taraxacum officinale (L.) Weber ex F.H.Wigg is a perennial herb of compositae, and our study has demonstrated that Taraxacum officinale polysaccharide has certain anti-tumor effect on HCC cells. Taraxasterol (TS) is a natural product extracted from Taraxacum officinale with strong physiological, pharmacological and biological activities, but the effect of TS on HCC is yet to be determined. Therefore, the aim of this study is to explore the effect of dandelion sterol on HCC in vivo and in vitro. The results showed that TS significantly inhibited the proliferation, induced apoptosis and blocked cell cycle in HCC cell lines HepG2 and Huh7 cells in vitro. TS inhibited the tumor growth of H22 bearing mice and the expression of Ki67 in vivo. More importantly, TS regulated the immunity of H22 bearing mice by elevating the ratio of CD4+ T cells in spleen, and increasing the number of T cell infiltration in tumor tissue. Except immunomodulation, the mechanism of tumor growth inhibition may be related to the regulation of apoptosis related proteins and IL-6/STAT3 pathway. TS significantly inhibited the growth of HCC cells both in vitro and in vivo. The study would provide a theoretical basis for the new application of TS and the adjuvant treatment of malignant tumor with traditional Chinese medicine.

Study of the anticancer potential of Cd complexes of selenazoyl-hydrazones and their sulfur isosters

The biological activity of Cd compounds has been investigated scarce since Cd has been recognized as a human carcinogen. However, the toxicity of cadmium is comparable to the toxicity of noble metals such as Pt and Pd. The paradigm of metal toxicity has been challenged suggesting that metal toxicity is not a constant property, yet it depends on many factors like the presence of appropriate ligands. Studies on anticancer activity of cadmium complexes showed that the complexation of various ligands resulted in complexes that showed better activities than approved drugs. In the present study, cadmium complexes with biologically potent thiazolyl/selenazoyl-hydrazone ligands have been prepared, and tested for their activity against different types of tumor cell models. The complexation of ligands with Cd(II) resulted in a synergistic effect. The antiproliferative activity study revealed that all complexes are more active compared to 5-fluorouracil and cisplatin. The mechanism of tumor cell growth inhibition reveal that selenium-based compounds induce cell death in T-47D (gland carcinoma) cells through apoptosis via caspase-3/7 activation. Additionally, their pro-apoptotic effect was stronger compared to etoposide and cisplatin. Nuclease activity, detected by gel electrophoresis, may be the possible mechanism of anticancer action of investigated complexes.

Artesunate Suppresses the Growth of Lung Cancer Cells by Downregulating the AKT/Survivin Signaling Pathway.

NSCLC (non-small-cell lung cancer) is the deadliest cancer in the world. Artesunate is one of the most potent and rapidly acting antimalarial agents. Recently, emerging evidence has suggested the anticancer function of artesunate. In our work, we aimed to investigate the molecular mechanism of artesunate-induced growth inhibition in human lung adenocarcinoma cells and reported that the anticancer effects of artesunate is related to its ability in downregulating AKT/Survivin signaling in A549 cells. The effect of artesunate on the proliferation of A549 cells was determined by CCK-8 assay and colony formation assay; its effect on A549 cell apoptosis was evaluated by lactate dehydrogenase (LDH) release assay. The role of artesunate on the activation of AKT/Survivin signaling was analyzed by western blot and quantitative QPCR. Finally, we used two mouse tumor models to investigate the function of artesunate on the in vivo growth of lung cancer cells. Artesunate treatment caused significant growth inhibition and apoptosis in A549 cells. Mechanistically, artesunate downregulated the activation of AKT/Survivin signaling. In agreement, hyperactivation of AKT signaling restored artesunate-induced growth inhibition in A549 cells. In mouse lung cancer models, artesunate administration significantly reduced the growth of A549 cells and LLC cells in nude mice and immunocompetent mice, respectively. Our findings suggest that artesunate serves as a potential tumor suppressor in lung cancer and hopefully can provide new insight into the development of therapeutic strategies in the clinical lung cancer treatment.