The epigenetic and non-epigenetic regulation of statins on its anti-tumor effect and its clinical research progress / 药学学报

Statins are a class of hydroxymethylglutaryl-CoA reductase inhibitors (HMG-CoA reductase inhibitors), which are widely used to reduce blood lipid in clinic, and are especially important for the prevention and treatment of cardiovascular diseases. In recent years, many studies at home and abroad believe that statins have a unique role in tumor prevention and treatment, and have been widely concerned. In terms of epigenetic regulation mechanism, statins mainly affect the progress of tumor through DNA methylation, histone modification and miRNA regulation. In addition, statins can also achieve their anti-tumor effects by promoting tumor cell autophagy, regulating tumor cell cycle, and promoting tumor cell apoptosis and other signaling pathways. Therefore, the research on statins provides ideas for the discovery of new anti-tumor treatments. In this paper, the role of statins in the prevention and treatment of common tumors is reviewed, including its mechanism of inhibiting the occurrence and development of tumors through epigenetic regulation and other related mechanisms, as well as its clinical research status.

Effect and Mechanism of Berberine Hydrochloride Against Lung Cancer Cells in Vitro Based on Mevalonate Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the efficacy and mechanism of berberine hydrochloride （BBH） against lung cancer cells through the mevalonate （MVA） pathway. MethodHuman lung cancer A549 cells and mouse Lewis lung carcinoma （LLC） cells were used as research subjects. Cell proliferation and cell counting kit-8 （CCK-8） assay were performed to detect the inhibitory effect of BBH （10， 20， 30， 40， 50 μmol·L-1） on the proliferation of the two kinds of cells （48 h）. Then cell scratch assay was used to explore the influence of BBH （40 μmol·L-1） on the migration of A549 and LLC cells （24， 48 h）， and colony formation assay was conducted to compare the colony formation ability of the cells under different concentrations of BBH （10， 20， 40 μmol·L-1）. Moreover， the effects of BBH （40 μmol·L-1） on the content of acetyl-coenzyme A （A-CoA） and total cholesterol （TC） in A549 and LLC cells were determined by kit assay. AutoDock Vina was used for the dock of BBH and MVA pathway regulatory protein， sterol regulatory element-binding protein 2 （SREBP2）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to observe the effects of BBH （40 μmol·L-1） on the mRNA expression of nine genes related to the MVA pathway in A549 and LLC cells： hydroxymethylglutaryl-CoA synthase 1 （HMGCS1）， hydroxymethylglutaryl-CoA Reductase （HMGCR）， mevalonate kinase （MVK）， phosphomevalonate kinase （PMVK）， mevalonate 5-pyrophosphate decarboxylase （MVD）， farnesyl diphosphate synthase （FDPS）， squalene epoxidase （SQLE）， farnesyl-diphosphate farnesyltransferase 1 （FDFT1）， and geranylgeranyl diphosphate synthase 1 （GGPS1）. Western blot was performed to clarify the effects of BBH （40 μmol·L-1） on the expression of three key proteins of the MVA pathway： HMGCS1， HMGCR， and FDFT1. The Cancer Genome Atlas （TCGA） database was searched to analyze the relationship between HMGCS1， HMGCR， FDFT1 and transcription gene SREBF2 in non-small cell lung cancer （NSCLC）. ResultCompared with the conditions in the control group， the proliferation， migration， and colony formation of A549 and LLC cells in the BBH group were decreased （P<0.01）， while the cell apoptosis rate was increased （P<0.01）. Molecular docking showed that BBH had good binding activity with SREBP2. In addition， the content of A-CoA and TC of the MVA pathway was reduced （P<0.01）. BBH down-regulated the mRNA expression of HMGCS1， HMGCR， MVK， PMVK， MVD， FDPS， SQLE， FDFT1， and GGPS1 in A549 and LLC cells （P<0.01）， and lowered the levels of HMGCS1， HMGCR， and FDFT1 proteins （P<0.05， P<0.01）. In NSCLC patients， HMGCS1， HMGCR， and FDFT1 were highly correlated with SREBF2 （R=0.54， R=0.57， and R=0.48）. ConclusionBBH can inhibit the proliferation， migration， and colony formation of A549 and LLC cells and promote cell apoptosis， which may be related to the regulation of MVA pathway by BBH binding to SREBP2.

Mvda is required for zebrafish early development

BACKGROUND: The MVD gene mutations are identified in porokeratosis, which is considered a skin-specific autoin- flammatory keratinization disease. However, the biological function of MVD gene remains largely unknown. Therefore, we analyzed the function of mvda gene, orthologous to the human MVD gene, in developing zebrafish. METHODS: Morpholino antisense oligonucleotide technique was used to generate mvda loss-of-function phenotypes. Knockdown of mvda was confirmed by RT-PCR and Sanger sequencing. Scanning and transmission electron microscopy were performed to analyze the morphology of the epidermis. Angiogenesis study was presented using the Tg(fli1a:EGFP)yl transgenic strain. In addition, acridine orange staining was used to examine the apoptotic cells in vivo. RESULTS: As expected, the mvda morphants showed abnormal morphology of the epidermis. Moreover, we observed ectopic sprouts in trunk angiogenesis and impaired formation of the caudal vein plexus in the mvda-deficient zebrafish. Besides, increased apoptosis was found throughout the tail, heart, and eyes in mvda zebrafish morphants. CONCLUSIONS: These findings indicated the essential role of mvda in the early development of zebrafish. This was the first in vivo knockdown study of the zebrafish mvda gene, which might offer insight into the biological function of the human MVD gene.

Relationship between breath isoprene excretion and oxidative stress responses to submaximal exercise / 体力科学

The physiological functions of expiratory isoprene, which is abundantly contained in human breath, are not well known. Recently, breath isoprene has been proposed to be related to oxidative stress, although no direct evidence has been reported. Therefore, the purpose of this study was to investigate the relationship between breath isoprene and oxidative stress status. Ten healthy male subjects performed a 20-min submaximal step-load cycling exercise, the intensity of which corresponded to a 60% peak oxygen uptake after a 10-min rest. Breath isoprene excretion during the exercise was calculated from the product of minute ventilation and isoprene expiratory concentration. To evaluate the oxidative stress, we collected blood samples from the subject’s fingertips before and immediately after the end of the exercise, and then diacron reactive oxygen metabolites (d-ROMs), which is an index of oxidative stress level, and biological antioxidant potential (BAP), which is an index of antioxidant potential, were measured. The breath isoprene concentration at the rest was significantly positively correlated with the ratio from BAP to d-ROMs (BAP/d-ROMs), which is an index of latent antioxidant potential (r = 0.63, P < 0.05). Furthermore, the change in breath isoprene excretion from before to after the exercise was significantly negatively correlated with the change in d-ROMs (r = -0.73, P < 0.05) and positively correlated with the change in BAP/d-ROMs (r = 0.88, P < 0.01). These results suggest that isoprene might play a role in the control of oxidative stress.

Role of rate-limiting step of mevalonate pathway in improving lycopene production in Escherichia coli / 生物工程学报

The introduction of the mevalonate pathway (MVA pathway) in recombinant Escherichia coli can improve the synthesis of terpenoids. But the imbalance expression of MVA pathway genes and accumulation of intermediates inhibit cell growth and terpenoids production. In this study, each gene of MVA pathway and key genes of lycopene synthesis pathway were cloned in plasmid to express in the recombinant E. coli LYC103 with optimizing the expression of the key genes of the 2-methyl-D-erythritol-4-phosphate pathway (MEP pathway), chromosome recombinant MVA pathway and the lycopene synthesis pathway. The results showed that the overexpression of ispA, crtE, mvaK1, idi and mvaD genes did not affect the cell growth, while lycopene production increased by 13.5%, 16.5%, 17.95%, 33.7% and 61.1% respectively, indicating that these genes may be the rate-limiting steps for the synthesis of lycopene. mvaK1, mvaK2, mvaD of MVA pathway were the rate-limiting steps and were in an operon. The mvaK1, mvaK2, mvaD operon was regulated by mRS (mRNA stabilizing region) library in front of mvaK1, obtaining strain LYC104. Lycopene yield of LYC104 was doubled and cell growth was increased by 32% compared with the control strain LYC103. CRISPR-cas9 technology was used to integrate idi into chromosome at lacZ site to obtain LYC105 strain. Cell growth of LYC105 was increased by 147% and lycopene yield was increased by 2.28 times compared with that of LYC103. In this study, each gene of lycopene synthesis pathway was expressed in plasmid to certify the rate-limiting gene based on the complete MVA pathway on the chromosome. Then the rate-limiting gene was integrated in chromosome with homologous recombination to release the rate-limiting, which providing a new strategy for the construction of high-yield strains for metabolic engineering.

Integrating balanced mevalonate pathway into chromosome for improving lycopene production in Escherichia coli / 生物工程学报

Isoprenoids are all derived from two five-carbon building blocks called isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), which are synthesized either by the mevalonate (MVA) pathway or 2-C-methyld-D-erythritol-4-phosphate (MEP) pathway. In this study, the MVA pathway genes were integrated into the chromosome of LYC101, in which the expression of key genes in the MEP synthesis pathway and lycopene synthesis pathway were optimized by artificial regulatory parts, to further improve the production of isoprenoids in Escherichia coli. The plasmids pALV23 and pALV145 were screened from a plasmid library that constructed by using the RBS library to link the genes of the MVA pathway, which greatly increased the production of β-carotene. The effects of plasmids pALV23 and pALV145 on the lycopene production in low and high lycopene production strain, LYC001 and LYC101, were compared, respectively. The production of lycopene was increased by plasmids pALV23 and pALV145 in both strains. In high lycopene production strain LYC101, pALV23 produced more lycopene than pALV145. Then, the MVA gene together of promoter of pALV23 was integrated into the chromosome of LYC101 at poxB site using method of homologous recombination helped by CRISPR-Cas9 system, resulted in genetically stable strain, LYC102. The yield of lycopene of LYC102 was 40.9 mg/g DCW, 1.19-folds higher than that of LYC101, and 20% more than that of LYC101 with pALV23. Simultaneous expression of MVA pathway and MEP pathway in recombinant E. coli can effectively increase the yield of terpenoids. In this study, a plasmid-free, genetically stable, high-yielding lycopene strain was constructed, which could be used for industrialization. Also, the platform strain can be used for the synthesis of other terpenoids.

Effects of Bisphosphonates on Glucose Transport in a Conditionally Immortalized Rat Retinal Capillary Endothelial Cell Line (TR-iBRB Cells)

The objective of the present study was to elucidate the effect of bisphosphonates, anti-osteoporosis agents, on glucose uptake in retinal capillary endothelial cells under normal and high glucose conditions. The change of glucose uptake by pre-treatment of bisphosphonates at the inner blood-retinal barrier (iBRB) was determined by measuring cellular uptake of [3H]3-O-methyl glucose (3-OMG) using a conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB cells) under normal and high glucose conditions. [3H]3-OMG uptake was inhibited by simultaneous treatment of unlabeled D-glucose and 3-OMG as well as glucose transport inhibitor, cytochalasin B. On the other hand, simultaneous treatment of alendronate or pamidronate had no significant inhibitory effect on [3H]3-OMG uptake by TR-iBRB cells. Under high glucose condition of TR-iBRB cells, [3H]3-OMG uptake was increased at 48 h. However, [3H]3-OMG uptake was decreased significantly by pre-treatment of alendronate or pamidronate compared with the values for normal and high glucose conditions. Moreover, geranylgeraniol (GGOH), a mevalonate pathway intermediate, increased the uptake of [3H]3-OMG reduced by bisphosphonates pre-treatment. But, pre-treatment of histamine did not show significant inhibition of [3H]3-OMG uptake. The glucose uptake may be down regulated by inhibiting the mevalonate pathway with pre-treatment of bisphosphonates in TR-iBRB cells at high glucose condition.

Research progress on key enzymes involved in biosynthesis of tanshinone / 中草药

Tanshinone, a group of diterpene quinones from Salviae Miltiorrhizae Radix with strong physiological activities and broad pharmacological effects, is well known as an effective compound to cure cardiovascular and cerebrovascular diseases. Natural tanshinone is generated by complex biosynthetic pathway and Salvia miltiorrhiza is its main source. The increasing medical demand for tanshinone, however, can not be satisfied. The limited resource of S. miltiorrhiza and the low content of tanshinone may cause the poor yield of these compounds. This problem may be solved by regulating the key enzymes involved in the biosynthesis of tanshinone so as to elevate its content. This review summarized the research progress in the biosynthetic pathway of tanshinone and the key enzymes related to this process.

Antiproliferative Effect of Lovastatin on Vascular Smooth Muscle Cell

BACKGROUND AND OBJECTIVES: This study was performed to investigate the antiproliferative effect of lovastatin on vascular smooth muscle cell, especially to determine whether lovastatin induces apoptosis in vascular smooth muscle cell and the products of mevalonate pathway can reverse the antiproliferative effect of lovastatin. METHODS AND MATERIALS: Lovastatin only and lovastatin with one of the products of mevalonate pathway such as isopentenyl adenine, farnesol, mevalonate, cholesterol were added respectively in cultured rat vascular smooth muscle cells stimulated with 10% fetal calf serum. DNA synthesis was measured by tritiated-thymidine incorporation. Cell number was determined by hemocytometric counting. Cells were Giemsa-stained to evaluate morphological changes of apoptosis. Extracted DNA from the cells treated with lovastatin was assessed by gel electrophoresis. RESULTS: 1)Lovastatin inhibited DNA synthesis and cell proliferation in a dose-dependent manner. 2)The inhibitory effects of lovastatin could be reversed almost completely by mevalonate, partially by farnesol. 3)Lovastatin-treated vascular smooth muscle cells showed typical morphological changes of apoptosis. 4)A distinct ladder of DNA bands was visualized by gel electrophoresis of the DNA from the cells treated with lovastatin. CONCLUSION: Mevalonate metabolism is essential for vascular smooth muscle cell proliferation. The antiproliferative effect of lovastatin may result from the induction of apoptosis in vascular smooth muscle cells.