A Comparison of Colorimetric and DNA Quantification Assays for the Assessment of Meniscal Fibrochondrocyte Proliferation in Microcarrier Culture

We have developed and refined a rapid, reliable method for the evaluation of attachment and proliferation of ovine meniscal chondrocytes in microcarrier culture. Assays measuring both mitochondrial activity, using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and MTS [3-(4,5-dimethylthiazol-2-yl)5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium], and DNA synthesis with a PicoGreen assay were compared. The MTT assay was the most sensitive at lower cell concentrations and enabled accurate assessment of cell proliferation over 14 day culture.     

Cellular stress induced by resazurin leads to autophagy and cell death via production of reactive oxygen species and mitochondrial impairment

Mitochondrial bioenergetics and reactive oxygen species (ROS) often play important roles in cellular stress mechanisms. In this study we investigated how these factors are involved in the stress response triggered by resazurin (Alamar Blue) in cultured cancer cells. Resazurin is a redox reactive compound widely used as reporter agent in assays of cell biology (e.g. cell viability and metabolic activity) due to its colorimetric and fluorimetric properties. In order to investigate resazurin‐induced stress mechanisms we employed cells affording different metabolic and regulatory phenotypes. In HL‐60 and Jurkat leukemia cells resazurin caused mitochondrial disintegration, respiratory dysfunction, reduced proliferation, and cell death. These effects were preceded by a burst of ROS, especially in HL‐60 cells which were also more sensitive and contained autophagic vesicles. Studies in Rho⁰ cells (devoid of mitochondrial DNA) indicated that the stress response does not depend on the rates of mitochondrial respiration. The anti‐proliferative effect of resazurin was confirmed in native acute myelogenous leukemia (AML) blasts. In conclusion, the data suggest that resazurin triggers cellular ROS production and thereby initiates a stress response leading to mitochondrial dysfunction, reduced proliferation, autophagy, and cell degradation. The ability of cells to tolerate this type of stress may be important in toxicity and chemoresistance. J. Cell. Biochem. 111: 574–584, 2010. © 2010 Wiley‐Liss, Inc.     

LncRNA SNHG14 potentiates pancreatic cancer progression via modulation of annexin A2 expression by acting as a competing endogenous RNA for miR‐613

This study aimed to determine long non‐coding RNA (lncRNA) small nucleolar RNA host gene 14 (SNHG14) expression in pancreatic cancer and to explore the potential molecular actions of SNHG14 in mediating pancreatic cancer progression. Gene expression was detected by quantitative real‐time PCR. Cell proliferation, growth and invasion were detected by respective CCK‐8, colony formation, and transwell invasion assays. Protein levels were measured by Western blotting. Cell apoptosis and caspase‐3 activity were detected by flow cytometry and caspase‐3 activity assay. The link between miR‐613 and its targets was evaluated by luciferase reporter assay. In vivo tumour growth was evaluated using a xenograft model of nude mice. SNHG14 expression was up‐regulated in cancerous tissues from pancreatic cancer patients. High expression of SNHG14 was associated with poor tumour differentiation, advanced TNM stage and nodal metastasis. SNHG14 overexpression enhanced cell proliferative, growth and invasive abilities, and suppressed apoptotic rates and caspase‐3 activity in pancreatic cancer cells, while SNHG14 knockdown exerted opposite effects. Mechanistic studies revealed that miR‐613 was targeted by SNHG14, and Annexin A2 (ANXA2) was targeted and inversely regulated by miR‐613 in pancreatic cancer cells. In vivo studies showed that SNHG14 knockdown attenuated tumour growth. MiR‐613 was down‐regulated and ANXA2 was up‐regulated in the pancreatic cancer tissues, and SNHG14 expression levels were inversely correlated with miR‐613 expression levels and positively correlated with the ANXA2 mRNA expression levels. Collectively, our results suggest that SNHG14 potentiates pancreatic cancer progression through modulation of annexin A2 expression via acting as a competing endogenous RNA for miR‐613.     

A role for two‐pore potassium (K2P) channels in endometrial epithelial function

The human endometrial epithelium is pivotal to menstrual cycle progression, implantation and early pregnancy. Endometrial function is directly regulated by local factors that include pH, oxygen tension and ion concentrations to generate an environment conducive to fertilization. A superfamily of potassium channels characterized by two‐pore domains (K2P) and encoded by KCNK genes is implicated in the control of the cell resting membrane potential through the generation of leak currents and modulation by various physicochemical stimuli. The aims of the study were to determine the expression and function of K2P channel subtypes in proliferative and secretory phase endometrium obtained from normo‐ovulatory women and in an endometrial cancer cell line. Using immunochemical methods, real‐time qRT‐PCR proliferation assays and electrophysiology. Our results demonstrate mRNA for several K2P channel subtypes in human endometrium with molecular expression of TREK‐1 shown to be higher in proliferative than secretory phase endometrium (P < 0.001). The K2P channel blockers methanandamide, lidocaine, zinc and curcumin had antiproliferative effects (P < 0.01) in an endometrial epithelial cancer cell line indicating a role for TASK and TREK‐1 channels in proliferation. Tetraethylammonium‐ and 4‐aminopyridine‐insensitive outwards currents were inhibited at all voltages by reducing extracellular pH from 7.4 to 6.6. Higher expression of TREK‐1 expression in proliferative phase endometrium may, in part, underlie linked to increased cell division. The effects of pH and a lack of effect of non‐specific channel blockers of voltage‐gated potassium channels imply a role for K2P channels in the regulation of human endometrial function.     

Effects of rGM-CSF on leukemia cell proliferation and on the incorporation of cytosine arabinoside into DNA.

In vitro studies of the effects of recombinant granulocyte macrophage-colony stimulating factor (rGM-CSF) on freshly obtained human leukemia cells were conducted to determine if there is a relationship between the effects of this growth factor on the proliferative characteristics of leukemia cells and on their incorporation of cytosine arabinoside (araC) into DNA. While rGM-CSF was found to be able to stimulate both leukemia cell proliferation and araC incorporation, for individual leukemia specimens there was no consistent relationship among these effects. In some specimens proliferation was stimulated without an increase in araC incorporation. The reverse was also observed. These studies demonstrate the difficulty in identifying assays capable of predicting the clinical effects of growth factors on leukemia cells in patients since the effect in vitro vary with the assay.     

Predictive features of ligand‐specific signaling through the estrogen receptor

Some estrogen receptor‐α (ERα)‐targeted breast cancer therapies such as tamoxifen have tissue‐selective or cell‐specific activities, while others have similar activities in different cell types. To identify biophysical determinants of cell‐specific signaling and breast cancer cell proliferation, we synthesized 241 ERα ligands based on 19 chemical scaffolds, and compared ligand response using quantitative bioassays for canonical ERα activities and X‐ray crystallography. Ligands that regulate the dynamics and stability of the coactivator‐binding site in the C‐terminal ligand‐binding domain, called activation function‐2 (AF‐2), showed similar activity profiles in different cell types. Such ligands induced breast cancer cell proliferation in a manner that was predicted by the canonical recruitment of the coactivators NCOA1/2/3 and induction of the GREB1 proliferative gene. For some ligand series, a single inter‐atomic distance in the ligand‐binding domain predicted their proliferative effects. In contrast, the N‐terminal coactivator‐binding site, activation function‐1 (AF‐1), determined cell‐specific signaling induced by ligands that used alternate mechanisms to control cell proliferation. Thus, incorporating systems structural analyses with quantitative chemical biology reveals how ligands can achieve distinct allosteric signaling outcomes through ERα.     

Evaluation of cell cycle arrest in estrogen responsive MCF-7 breast cancer cells: pitfalls of the MTS assay

Endocrine resistance is a major problem with anti-estrogen treatments and how to overcome resistance is a major concern in the clinic. Reliable measurement of cell viability, proliferation, growth inhibition and death is important in screening for drug treatment efficacy in vitro. This report describes and compares commonly used proliferation assays for induced estrogen-responsive MCF-7 breast cancer cell cycle arrest including: determination of cell number by direct counting of viable cells; or fluorescence SYBR®Green (SYBR) DNA labeling; determination of mitochondrial metabolic activity by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay; assessment of newly synthesized DNA using 5-ethynyl-2′-deoxyuridine (EdU) nucleoside analog binding and Alexa Fluor® azide visualization by fluorescence microscopy; cell-cycle phase measurement by flow cytometry. Treatment of MCF-7 cells with ICI 182780 (Faslodex), FTY720, serum deprivation or induction of the tumor suppressor p14ARF showed inhibition of cell proliferation determined by the Trypan Blue exclusion assay and SYBR DNA labeling assay. In contrast, the effects of treatment with ICI 182780 or p14ARF-induction were not confirmed using the MTS assay. Cell cycle inhibition by ICI 182780 and p14ARF-induction was further confirmed by flow cytometric analysis and EdU-DNA incorporation. To explore this discrepancy further, we showed that ICI 182780 and p14ARF-induction increased MCF-7 cell mitochondrial activity by MTS assay in individual cells compared to control cells thereby providing a misleading proliferation readout. Interrogation of p14ARF-induction on MCF-7 metabolic activity using TMRE assays and high content image analysis showed that increased mitochondrial activity was concomitant with increased mitochondrial biomass with no loss of mitochondrial membrane potential, or cell death. We conclude that, whilst p14ARF and ICI 182780 stop cell cycle progression, the cells are still viable and potential treatments utilizing these pathways may contribute to drug resistant cells. These experiments demonstrate how the combined measurement of metabolic activity and DNA labeling provides a more reliable interpretation of cancer cell response to treatment regimens.     

A combined strategy to reduce restenosis for vascular tissue engineering applications

Biodegradable polymers including poly(l-lactic acid) (PLLA) have been used to develop cardiovascular prostheses such as vascular grafts and stents. However, implant-associated thrombosis, inflammation, and restenosis are still major obstacles for the utility of these devices. The lack of an endothelial cell (EC) lining (endothelialization) on the implants and the responses of the immune systems toward the implants have been associated with these complications. In our research strategy, we have combined the drug delivery principle with the strategies of tissue engineering, the controlled release of anti-inflammation drugs and enhanced endothelialization, to reduce the implant-associated adverse responses. We first integrated curcumin, an anti-inflammatory drug and anti-smooth muscle cell (SMC) proliferative drug, with PLLA. This curcumin-loaded PLLA material was then modified using adsorptive coating of adhesive proteins such as fibronectin, collagen-I, vitronectin, laminin, and matrigel to improve the endothelial cell (EC) adhesion and proliferation, and ECs were seeded on top of these modified surfaces. Our results showed steady drug release kinetics over the period of 50 days from curcumin-loaded PLLA materials. Additionally, integration of curcumin in PLLA increased the roughness of the scaffold at the nanometric scale using an atomic force microscopic analysis. Moreover, coating with fibronectin on curcumin-loaded PLLA surfaces gave the highest EC adhesion and proliferation compared to other adhesive proteins using PicoGreen DNA assays. The ability of our strategy to release the curcumin for producing anti-inflammation and anti-proliferation responses and to improve EC adhesion and growth after EC seeding suggests this strategy may reduce implant-associated adverse responses and be a better approach for vascular tissue engineering applications.     

The endothelization of polyhedral oligomeric silsesquioxane nanocomposites

It has been recognized that seeding vascular bypass grafts with endothelial cells is the ideal method of improving their long-term patency rates. The aim of this study was to assess the in vitro cytocompatibility of a novel silica nanocomposite, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane (POSS-PCU) and hence elicit its feasibility at the vascular interface for potential use in cardiovascular devices such as vascular grafts. Using primary human umbilical vein endothelial cells (HUVEC), cell viability and adhesion were studied using AlamarBlue assays, whereas cell proliferation on the polymer was assessed using the PicoGreen dye assay. Cellular confluence and morphology on the nanocomposite were analyzed using light and electron microscopy, respectively. Our results showed that there was no significant difference between cell viability in standard culture media and POSS-PCU. Endothelial cells were capable of adhering to the polymer within 30 min of contact (Student's t-test, p<0.05) with no difference between POSS-PCU and control cell culture plates. POSS-PCU was also capable of sustaining good cell proliferation for up to 14d even from low seeding densities (1.0×10³ cells/cm²) and reaching saturation by 21 d. Microscopic analysis showed evidence of optimal endothelial cell adsorption morphology with the absence of impaired motility and morphogenesis. In conclusion, these results support the application of POSS-PCU as a suitable biomaterial scaffold in bio-hybrid vascular prostheses and biomedical devices.     

miRNA‐4317 suppresses human gastric cancer cell proliferation by targeting ZNF322

Studies have shown that miR‐4317 is dysregulated in tumor, but the biologic role of miR‐4317 in tumor development and progression remains unknown. The present study aimed to investigate the role of miR‐4317 in human gastric cancer. Quantitative real‐time PCR was used to quantify miR‐4317 expression levels in clinical gastric cancer specimens and cell lines. MTT, colony formation and cell cycle assays were performed to identify the contributions of miR‐4317 to cell proliferation in gastric cancer cell lines. The results showed that miR‐4317 was significantly decreased in 17 clinical gastric cancer specimens compared with adjacent non‐tumor stomach tissues. Forced expression of miR‐4317 suppressed gastric cancer cell proliferation and blocked S‐G2/M transition. Bioinformatics and dual‐luciferase reporter assays confirmed that ZNF322 is a direct target of miR‐4317. Silencing ZNF322 recapitulated the cellular and molecular effects seen upon miR‐4317 overexpression. These findings indicate that miR‐4317 represses the proliferation of gastric cancer cell, at least in part, by targeting and suppressing ZNF322 and that it may serve as a therapeutic target for gastric cancer treatment.     

Downregulation of the Werner syndrome protein induces a metabolic shift that compromises redox homeostasis and limits proliferation of cancer cells

The Werner syndrome protein (WRN) is a nuclear protein required for cell growth and proliferation. Loss‐of‐function mutations in the Werner syndrome gene are associated with the premature onset of age‐related diseases. How loss of WRN limits cell proliferation and induces replicative senescence is poorly understood. Here, we show that WRN depletion leads to a striking metabolic shift that coordinately weakens the pathways that generate reducing equivalents for detoxification of reactive oxygen species and increases mitochondrial respiration. In cancer cells, this metabolic shift counteracts the Warburg effect, a defining characteristic of many malignant cells, resulting in altered redox balance and accumulation of oxidative DNA damage that inhibits cell proliferation and induces a senescence‐like phenotype. Consistent with these findings, supplementation with antioxidant rescues at least in part cell proliferation and decreases senescence in WRN‐knockdown cancer cells. These results demonstrate that WRN plays a critical role in cancer cell proliferation by contributing to the Warburg effect and preventing metabolic stress.     

Effect of a synthetic cannabinoid agonist on the proliferation and invasion of gastric cancer cells

Although cannabinoids are associated with antineoplastic activity in a number of cancer cell types, the effect in gastric cancer cells has not been clarified. In the present study, we investigated the effects of a cannabinoid agonist on gastric cancer cell proliferation and invasion. The cannabinoid agonist WIN 55,212‐2 inhibited the proliferation of human gastric cancer cells in a dose‐dependent manner and that this effect was mediated partially by the CB₁ receptor. We also found that WIN 55,212‐2 induced apoptosis and down‐regulation of the phospho‐AKT expression in human gastric cancer cells. Furthermore, WIN 55,212‐2 treatment inhibited the invasion of gastric cancer cells, and down‐regulated the expression of MMP‐2 and VEGF‐A through the cannabinoid receptors. Our results open the possibilities in using cannabinoids as a new gastric cancer therapy. J. Cell. Biochem. 110: 321–332, 2010. © 2010 Wiley‐Liss, Inc.     

A computational study of the Warburg effect identifies metabolic targets inhibiting cancer migration

Over the last decade, the field of cancer metabolism has mainly focused on studying the role of tumorigenic metabolic rewiring in supporting cancer proliferation. Here, we perform the first genome‐scale computational study of the metabolic underpinnings of cancer migration. We build genome‐scale metabolic models of the NCI‐60 cell lines that capture the Warburg effect (aerobic glycolysis) typically occurring in cancer cells. The extent of the Warburg effect in each of these cell line models is quantified by the ratio of glycolytic to oxidative ATP flux (AFR), which is found to be highly positively associated with cancer cell migration. We hence predicted that targeting genes that mitigate the Warburg effect by reducing the AFR may specifically inhibit cancer migration. By testing the anti‐migratory effects of silencing such 17 top predicted genes in four breast and lung cancer cell lines, we find that up to 13 of these novel predictions significantly attenuate cell migration either in all or one cell line only, while having almost no effect on cell proliferation. Furthermore, in accordance with the predictions, a significant reduction is observed in the ratio between experimentally measured ECAR and OCR levels following these perturbations. Inhibiting anti‐migratory targets is a promising future avenue in treating cancer since it may decrease cytotoxic‐related side effects that plague current anti‐proliferative treatments. Furthermore, it may reduce cytotoxic‐related clonal selection of more aggressive cancer cells and the likelihood of emerging resistance.     

Anti-breast cancer and anti-angiogenic potential of a lichen-derived small-molecule: barbatolic acid

Natural products have been used for centuries as the most potent remedies to cure many diseases including cancer diseases. Angiogenesis is defined as the formation of new capillaries from existing vessels and plays a key role in the tumorigenesis process. Barbatolic acid is a little known lichen-derived small-molecule. In the present study, barbatolic acid was isolated from the acetone extract of Bryoria capillaris, and its anti-breast cancer and anti-angiogenic potential was investigated using human umbilical vein endothelial cells (HUVECs), human breast ductal carcinoma (T-47D) and cisplatin-resistant BRCA2-mutated human breast TNM stage IV adenocarcinoma (HCC1428) cells. AlamarBlue? cell viability, lactate dehydrogenase cellular membrane degradation and PicoGreen? dsDNA quantitation assays were performed to determine the cytotoxic potential of barbatolic acid. Anti-angiogenic and anti-migratory activities were investigated using endothelial tube formation assay and scratch wound healing assay, respectively. Half maximal inhibitory concentration of barbatolic acid was found to be higher than 100 µM for HUVEC, HCC1428 and T-47D cells. The sub-cytotoxic concentrations such as 25 µM, 50 µM and 100 µM were applied to determine anti-angiogenic and anti-migratory activities. Although the sub-cytotoxic concentrations inhibited endothelial tube formation and cellular migration in a concentration depended manner, barbatolic acid was more effective on the migration of HCC1428 and T-47D breast cancer cells than the migration of HUVECs. Consequently, the findings suggest that barbatolic acid is a promising anti-angiogenic and anti-migratory agent and the underlying activity mechanisms should be investigated by further in vitro and in vivo experiments.     

Tomentosin induces apoptotic pathway by blocking inflammatory mediators via modulation of cell proteins in AGS gastric cancer cell line

In this study, we investigated the in vitro effect of tomentosin on cell proliferation by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay, reactive oxygen species by 2′,7′‐dichlorofluorescein diacetate staining assay, apoptosis (AO/EtBr, propidium iodide, and 4′,6‐diamidino‐2‐phenylindole staining, mitochondrial membrane potential), cell adherent, cell migration, inflammation, apoptosis, and oxidative stress from gastric cancer cells (GCCs) AGS. Upon their relative cell proliferative, inflammatory, and apoptotic molecular markers were analyzed by using the enzyme‐linked immunosorbent assay and Western blot analysis method. Treatment with tomentosin (IC₅₀ = 20 µM) significantly inhibited cell proliferation and oxidative stress‐induced anti‐cell proliferative (proliferating cell nuclear antigen and cyclin‐D1) also regulated expression, drastically diminished tumor necrosis factor‐α, nuclear factor‐κB, interleukin‐6, and interleukin‐1β expression levels, significantly upregulated Bcl‐2 and Bax expression. Thus, this tomentosin can significantly reduce GCC proliferation via cytotoxicity which is stimulated apoptosis markers via morphology staining changes and inhibitory inflammatory markers. The tomentosin‐induced oxidative stress may be involved to stimulate apoptotic mechanisms via mitochondria‐mediated signaling by the inhibition of inflammation. Taken together, our findings suggest a possible future use of chemotherapeutic agents for pharmacological benefits and as an anti‐cancer treatment option.     

Geraniol and simvastatin show a synergistic effect on a human hepatocarcinoma cell line

Simvastatin is a competitive inhibitor of 3‐hydroxymethylglutaryl coenzyme A reductase activity, whereas geraniol is a monoterpene with multiple pharmacologic effects on mevalonate metabolism. Both of them inhibit growth and proliferation of many cell lines. The present study was designed to determine the action of geraniol, in combination with simvastatin, by assessing their effects in vitro on human hepatocarcinoma cell line (Hep G2). The treatment of Hep G2 cells with concentrations of simvastatin or geraniol that did not inhibit cell proliferation (5 µmol·l^‐1 of simvastatin and 50 µmol·l^‐1 of geraniol) resulted in a significant inhibition of cell proliferation. We also examined the effect of simvastatin, geraniol and the combination of both on the biosynthesis of lipids from [¹⁴C]‐acetate. Our results demonstrate that the combination of simvastatin and geraniol synergistically inhibited cholesterol biosynthesis and proliferation of Hep G2 cell line, contributing to a better understanding of the action of a component of essential oils targeting a complex metabolic pathway, which would improve the use of drugs or their combination in the fight against cancer and/or cardiovascular diseases. Copyright © 2011 John Wiley & Sons, Ltd.     

甲状旁腺素对成骨样细胞增殖的调节作用

甲状旁腺素（ＰＴＨ）是调节钙磷代谢的经典激素,有报道ＰＴＨ对其靶细胞－成骨细胞有促增殖分化作用。经多层次、多水平的实验研究证实,ＰＴＨ对成骨样细胞ＲＯＳ１７／２．８确有促增殖作用。（１）细胞计数、ＭＴＴ［３－（４,５－ｄｉｍｅｔｈｙｌｔｈｉａ－ｚｏｌ－ｚ－ｙｉ）２,５－ｄｉｐｈｅｎｙｌｔｅｔｒａｚｏｌｉｕｍｂｒｏｍｉｄｅ］测定及ＳＲＢ（ｓｏｄｉｕｍｒｈｏｄａｍｉｎｅＢ,ＳＲＢ）染色均显示经ＰＴＨ（１０－９ｍｏｌ／Ｌ）处理的细胞,其数目明显增加;（２）３Ｈ－ＴｄＲ参入增加;（３）与增殖相关的原癌基因（ｃ－ｆｏｓ、ｃ－ｊｕｎ、ｃ－ｋｉ－ｒａｓ和ｃ－ｍｙｃ）的表达增强;（４）成骨细胞特征性蛋白－碱性磷酸酶活性降低．这些结果不仅表明该激素具有非经典样作用,同时意味着激素也参与其靶细胞增殖分化的调节作用     

Colorimetric cell proliferation assay for microorganisms in microtiter plate using water-soluble tetrazolium salts

A colorimetric method to assay cell proliferation of microorganisms in 96-well microtiter plates using water-soluble tetrazolium salts and electron mediators was developed. Combinations of 6 kinds of water-soluble tetrazolium salts and 27 kinds of electron mediators that considered the metabolic efficiency of microorganisms and the influence with medium components were investigated. 2-Methyl-1,4-naphthoquinone (NQ) was reduced most effectively by various species of microorganisms, and a combination of WST-8 as a water-soluble tetrazolium salt with 2-methyl-1,4-NQ repressed the increase in background due to medium components. In the presence of 2-methyl-1,4-NQ, WST-8 was reduced by microbial cells to formazan, which exhibited maximum absorbance at 460 nm. The proposed tetrazolium method could be applied to measure proliferations of various microbial cells including 3 kinds of yeast, 9 kinds of Gram-positive bacteria, and 10 kinds of Gram-negative bacteria. Linear relationships between the absorbance and viable microbial cell density were obtained in all microorganisms, suggesting that the absorbance change reflected the microbial cell proliferation.     

Protein abundance of AKT and ERK pathway components governs cell type‐specific regulation of proliferation

Signaling through the AKT and ERK pathways controls cell proliferation. However, the integrated regulation of this multistep process, involving signal processing, cell growth and cell cycle progression, is poorly understood. Here, we study different hematopoietic cell types, in which AKT and ERK signaling is triggered by erythropoietin (Epo). Although these cell types share the molecular network topology for pro‐proliferative Epo signaling, they exhibit distinct proliferative responses. Iterating quantitative experiments and mathematical modeling, we identify two molecular sources for cell type‐specific proliferation. First, cell type‐specific protein abundance patterns cause differential signal flow along the AKT and ERK pathways. Second, downstream regulators of both pathways have differential effects on proliferation, suggesting that protein synthesis is rate‐limiting for faster cycling cells while slower cell cycles are controlled at the G1‐S progression. The integrated mathematical model of Epo‐driven proliferation explains cell type‐specific effects of targeted AKT and ERK inhibitors and faithfully predicts, based on the protein abundance, anti‐proliferative effects of inhibitors in primary human erythroid progenitor cells. Our findings suggest that the effectiveness of targeted cancer therapy might become predictable from protein abundance.     

Plantamajoside inhibits the proliferation and epithelial‐to‐mesenchymal transition in hepatocellular carcinoma cells via modulating hypoxia‐inducible factor‐1α‐dependent gene expression

As a potential antitumor herbal medicine, plantamajoside (PMS) benefits the treatment of many human malignances. However, the role of PMS in the progression of hepatocellular carcinoma (HCC) and the related molecular mechanisms is still unknown. Here, we proved that the cell viabilities of HepG2 cells were gradually decreased with the increasing concentrations of CoCl₂ and/or PMS via cell counting kit‐8 assay. Meanwhile, 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) and western blot assays were used to further confirm that PMS inhibited the CoCl₂‐induced cell proliferation in HepG2 cells via suppressing the Ki67 and proliferating cell nuclear antigen expressions. We also performed wound‐healing and transwell assays and demonstrated that PMS inhibited CoCl₂‐induced migration and invasion in HepG2 cells via suppressing the epithelial–mesenchymal transition (EMT) process. In addition, the use of 3‐(5′‐hydroxymethyl‐2′‐furyl)‐1‐benzylindazole further proved that PMS inhibited the malignant biological behaviors of HepG2 cells under hypoxic condition by suppressing the hypoxia‐inducible factor‐1α (HIF‐1α) expression. Besides, we further confirmed that PMS suppressed the growth and metastasis of implanted tumors in vivo. Given that PMS suppressed the proliferation and EMT induced by CoCl₂ in HCC cells via downregulating HIF‐1α signaling pathway, we provided evidence that PMS might be a novel anti‐cancer drug for HCC treatment.