Statins enhance the efficacy of HER2-targeting radioligand therapy in drug-resistant gastric cancers.

Human epidermal growth factor receptor 2 (HER2) is overexpressed in various cancer types. HER2-targeting trastuzumab plus chemotherapy is used as first-line therapy for HER2-positive recurrent or primary metastatic gastric cancer, but intrinsic and acquired trastuzumab resistance inevitably develop over time. To overcome gastric cancer resistance to HER2-targeted therapies, we have conjugated trastuzumab with a beta-emitting therapeutic isotope, lutetium-177, to deliver radiation locally to gastric tumors with minimal toxicity. Because trastuzumab-based targeted radioligand therapy (RLT) requires only the extramembrane domain binding of membrane-bound HER2 receptors, HER2-targeting RLT can bypass any resistance mechanisms that occur downstream of HER2 binding. Leveraging our previous discoveries that statins, a class of cholesterol-lowering drugs, can enhance the cell surface-bound HER2 to achieve effective drug delivery in tumors, we proposed that the combination of statins and [177Lu]Lu-trastuzumab-based RLT can enhance the therapeutic efficacy of HER2-targeted RLT in drug-resistant gastric cancers. We demonstrate that lovastatin elevates cell surface HER2 levels and increases the tumor-absorbed radiation dose of [177Lu]Lu-DOTA-trastuzumab. Furthermore, lovastatin-modulated [177Lu]Lu-DOTA-trastuzumab RLT durably inhibits tumor growth and prolongs overall survival in mice bearing NCI-N87 gastric tumors and HER2-positive patient-derived xenografts (PDXs) of known clinical resistance to trastuzumab therapy. Statins also exhibit a radioprotective effect, reducing radiotoxicity in a mice cohort given the combination of statins and [177Lu]Lu-DOTA-trastuzumab. Since statins are commonly prescribed to patients, our results strongly support the feasibility of clinical studies that combine lovastatin with HER2-targeted RLT in HER2-postive patients and trastuzumab-resistant HER2-positive patients.

The mechanism of lovastatin in suppressing the proliferation of esophageal squamous cell carcinoma based on proteomics.

BACKGROUND: Lovastatin, a type of statin usually considered as a lipid-lowering drug that lowers blood cholesterol and low-density lipoprotein cholesterol levels, has been rediscovered to have anticancer activity. Fewer studies exist regarding the effect of lovastatin on esophageal squamous cell carcinoma (ESCC). METHODS: Here, we report that lovastatin shows anticancer effect on ESCC By affecting the mitochondrial autophagy pathway. Moreover, based on proteomics and computer molecular simulations found that RAB38 and RAB27A may be a target of lovastatin. RESULTS: We observed that autophagy of mitochondria is inhibited by lovastatin, affecting esophageal squamous cell proliferation. There is a possible link between the expression of RAB38, RAB27A and immune cell invasion in esophageal cancer. CONCLUSIONS: These results demonstrate the huge potential of lovastatin as an RAB38, RAB27A inhibitor in esophageal cancer chemotherapy and chemoprevention.

Statins enhance extracellular release of hepatitis C virus particles through ERK5 activation.

Statins, such as lovastatin, have been known to inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Statins were reported to moderately suppress hepatitis C virus (HCV) replication in cultured cells harboring HCV RNA replicons. We report here using an HCV cell culture (HCVcc) system that high concentrations of lovastatin (5-20 µg/mL) markedly enhanced the release of HCV infectious particles (virion) in the culture supernatants by up to 40 times, without enhancing HCV RNA replication, HCV protein synthesis, or HCV virion assembly in the cells. We also found that lovastatin increased the phosphorylation (activation) level of extracellular-signal-regulated kinase 5 (ERK5) in both the infected and uninfected cells in a dose-dependent manner. The lovastatin-mediated increase of HCV virion release was partially reversed by selective ERK5 inhibitors, BIX02189 and XMD8-92, or by ERK5 knockdown using small interfering RNA (siRNA). Moreover, we demonstrated that other cholesterol-lowering statins, but not dehydrolovastatin that is incapable of inhibiting HMG-CoA reductase and activating ERK5, enhanced HCV virion release to the same extent as observed with lovastatin. These results collectively suggest that statins markedly enhance HCV virion release from infected cells through HMG-CoA reductase inhibition and ERK5 activation.

Aculeatiols A-G: Lovastatin Derivatives Extracted from Aspergillus aculeatus.

In this study, we isolated lovastatin derivatives, including aculeatiols A-G (1-7) and three known compounds (8-10), from Aspergillus aculeatus. Their structures and absolute configurations were experimentally determined by high-resolution electrospray ionization mass spectrometry, nuclear magnetic resonance spectroscopy, and X-ray diffraction analyses, and the results were corroborated by quantum-chemical calculations. As members of the lovastatin derivatives, aculeatiols A-C (1-3) possess a γ-lactone functional group in the side chain. Compound 6 represents the first example that features an undescribed aromatized heterotetracyclic 6/6/6/6 ring system. Biologically, the lipid-lowering effects of all of these compounds were evaluated by analyzing the free fatty acid-induced intracellular lipid accumulation. In addition, compound 5, which regulated the transcription of genes associated with lipid uptake and synthesis, inhibited the accumulation of lipids.

Identification of lovastatin production in Aspergillus terreus strain (KF971363.1) and its antifungal role.

Lovastatin has received interest for its potential therapeutic use in treating numerous diseases, for example, the blood cholesterol level by restraining hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. The research utilized the fungal growth bioassay technique to disengage and evaluate filamentous organism for the lovastatin creation. The clever type of Aspergillus terreus (KF971363.1) was embraced for lovastatin creation by solid-state fermentation (SSF). Lovastatin production was optimized using physiological parameters such as pH and temperature at SSF. The addition of nitrogen source enhanced the production of lovastatin by the breakdown of lignocellulose that improved the production of lovastatin. The research verified a yeast growth inhibition bioassay approach, in addition to thin-layer chromatography and liquid chromatography-mass spectrometry (LC-MS). All of these techniques were used to confirm lovastatin production. The purified extract subjected to the TLC analysis showed retention factor (Rf) value of 0.73. Moreover, the inhibition bioassay method reassures the lovastatin production by comparing the zone of inhibition against C. albicans.

Linoleic acid functions as a quorum-sensing molecule in Monascus purpureus-Saccharomyces cerevisiae co-culture.

When Monascus purpureus was co-cultured with Saccharomyces cerevisiae, we noted significant changes in the secondary metabolism and morphological development of Monascus. In yeast co-culture, although the pH was not different from that of a control, the Monascus mycelial biomass increased during fermentation, and the Monacolin K yield was significantly enhanced (up to 58.87% higher). However, pigment production did not increase. Co-culture with S. cerevisiae significantly increased the expression levels of genes related to Monacolin K production (mokA-mokI), especially mokE, mokF, and mokG. Linoleic acid, that has been implicated in playing a regulating role in the secondary metabolism and morphology of Monascus, was hypothesized to be the effector. Linoleic acid was detected in the co-culture, and its levels changed during fermentation. Addition of linoleic acid increased Monacolin K production and caused similar morphological changes in Monascus spores and mycelia. Exogenous linoleic acid also significantly upregulated the transcription levels of all nine genes involved in the biosynthesis of Monacolin K (up to 69.50% higher), consistent with the enhanced Monacolin K yield. Taken together, our results showed the effect of S. cerevisiae co-culture on M. purpureus and suggested linoleic acid as a specific quorum-sensing molecule in Saccharomyces-Monascus co-culture.

Lovastatin inhibits erythroleukemia progression through KLF2-mediated suppression of MAPK/ERK signaling.

BACKGROUND: Lovastatin, an HMG-CoA inhibitor and an effective cholesterol lowering drug, exhibits anti-neoplastic activity towards several types of cancer, although the underlying mechanism is still not fully understood. Herein, we investigated mechanism of growth inhibition of leukemic cells by lovastatin. METHODS: RNAseq analysis was used to explore the effect of lovastatin on gene expression in leukemic cells. An animal model of leukemia was used to test the effect of this statin in vivo. FAM83A and DDIT4 expression was knocked-downed in leukemia cells via lentivirus-shRNA. Western blotting, RT-qPCR, cell cycle analysis and apoptosis assays were used to determine the effect of lovastatin-induced growth suppression in leukemic cells in vitro. RESULTS: Lovastatin treatment strongly inhibited cancer progression in a mouse model of erythroleukemia induced by Friend virus. In tissue culture, lovastatin inhibited cell proliferation through induction of G1 phase cell cycle arrest and apoptosis. Interestingly, lovastatin induced most known genes associated with cholesterol biosynthesis in leukemic cells. Moreover, it suppressed ERK1/2 phosphorylation by downregulating FAM83A and DDIT4, two mediators of MAP-Kinase signaling. RNAseq analysis of lovastatin treated leukemic cells revealed a strong induction of the tumor suppressor gene KLF2. Accordingly, lentivirus-mediated knockdown of KLF2 antagonized leukemia cell suppression induced by lovastatin, associated with higher ERK1/2 phosphorylation compared to control. We further show that KLF2 induction by lovastatin is responsible for lower expression of the FAM83A and DDIT4 oncogenes, involved in the activation of ERK1/2. KLF2 activation by lovastatin also activated a subset of cholesterol biosynthesis genes that may further contribute to leukemia suppression. CONCLUSIONS: These results implicate KLF2-mediated FAM83A/DDIT4/MAPK suppression and activation of cholesterol biosynthesis as the mechanism of leukemia cell growth inhibition by lovastatin.

Bioconversion of lovastatin to simvastatin by Streptomyces carpaticus toward the inhibition of HMG-CoA activity.

The aim of this study was the modification of lovastatin by microbes to improve its potential. Actinobacteria exhibit staggering diversity in terms of their biosynthetic capability for specialized metabolites which has been traced back to the presence of specialized gene clusters. The objective of the study is to exploit the potential of Actinobacteria strain(s), which can biotransform lovastatin to simvastatin, which might be a more potent therapeutic agent than lovastatin. We have screened 40 Actinobacteria strains and assessed their biotransformation potential primarily through thin layer chromatography (TLC) analysis, followed by high performance thin layer chromatography and high performance liquid chromatography analysis. One strain C7 (CTL S12) has been identified as a potential Actinobacteria that favored the simvastatin biotransformation. The morphological and biochemical analysis together with 16S rRNA sequencing coupled with phylogenetic analysis confirmed the ideal strain (C7) as Streptomyces carpaticus. Successively, the purified simvastatin from S. carpaticus was characterized by liquid chromatography-mass spectrometry (LC-MS), infrared spectrometry, nuclear magnetic resonance, and HMG-CoA assay. In the LC-MS analysis, a peak at 419.24 m/z confirmed the elemental composition of simvastatin (C25 H39 O5 ). In HMG-CoA assay, the IC50 of simvastatin was 50 µg/ml, and the inhibitory potential was 1.36 times higher compared to that of lovastatin. Thus, the biotransformation of simvastatin from lovastatin by S. carpaticus is reported for the first time.

Suppressive role of lovastatin in intracerebral hemorrhage through repression of autophagy.

Statins possess critical function in the brain. Here, we intended to investigate the role of lovastatin in brain damage after intracerebral hemorrhage (ICH). A collagenase-induced ICH rat model was established followed by lovastatin treatment. Then, the effect of lovastatin on ICH-induced brain damage was explored with cognitive function, learning and memory abilities, and neurological damage of rats analyzed. Besides, brain water content, number of degenerate neurons, Nissl's body, and apoptosis of neurons were detected. Oxidative stress levels, inflammation, and autophagy levels in ICH were measured after treatment of lovastatin. Lovastatin improved the cognitive impairment of rats, enhanced their spatial learning and memory abilities, reduced nervous system damage, lesion area, and brain water content after ICH. Lovastatin was capable of reducing the number of degenerated neurons, the apoptosis level, autophagy level, and increasing the number of Nissl's body. Lovastatin inhibited the oxidative stress response and inflammatory factors in the brain tissue after ICH, and increased the expression of anti-inflammatory factor IL-10. Lovastatin inhibited AMPK/mTOR signaling pathway after ICH. Our study highlighted the suppressive role of lovastatin in ICH-induced brain damage.

Computer-aided, resistance gene-guided genome mining for proteasome and HMG-CoA reductase inhibitors.

Secondary metabolites (SMs) are biologically active small molecules, many of which are medically valuable. Fungal genomes contain vast numbers of SM biosynthetic gene clusters (BGCs) with unknown products, suggesting that huge numbers of valuable SMs remain to be discovered. It is challenging, however, to identify SM BGCs, among the millions present in fungi, that produce useful compounds. One solution is resistance gene-guided genome mining, which takes advantage of the fact that some BGCs contain a gene encoding a resistant version of the protein targeted by the compound produced by the BGC. The bioinformatic signature of such BGCs is that they contain an allele of an essential gene with no SM biosynthetic function, and there is a second allele elsewhere in the genome. We have developed a computer-assisted approach to resistance gene-guided genome mining that allows users to query large databases for BGCs that putatively make compounds that have targets of therapeutic interest. Working with the MycoCosm genome database, we have applied this approach to look for SM BGCs that target the proteasome ß6 subunit, the target of the proteasome inhibitor fellutamide B, or HMG-CoA reductase, the target of cholesterol reducing therapeutics such as lovastatin. Our approach proved effective, finding known fellutamide and lovastatin BGCs as well as fellutamide- and lovastatin-related BGCs with variations in the SM genes that suggest they may produce structural variants of fellutamides and lovastatin. Gratifyingly, we also found BGCs that are not closely related to lovastatin BGCs but putatively produce novel HMG-CoA reductase inhibitors. ONE-SENTENCE SUMMARY: A new computer-assisted approach to resistance gene-directed genome mining is reported along with its use to identify fungal biosynthetic gene clusters that putatively produce proteasome and HMG-CoA reductase inhibitors.

Performance and mechanism of co-culture of Monascus purpureus, Lacticaseibacillus casei, and Saccharomyces cerevisiae to enhance lovastatin production and lipid-lowering effects.

To facilitate lipid-lowering effects, a lovastatin-producing microbial co-culture system (LPMCS) was constituted with a novel strain Monascus purpureus R5 in combination with Lacticaseibacillus casei S5 and Saccharomyces cerevisiae J7, which increased lovastatin production by 54.21% compared with the single strain R5. Response Surface Methodology (RSM) optimization indicated lovastatin yield peaked at 7.43 mg/g with a fermentation time of 13.88 d, water content of 50.5%, and inoculum ratio of 10.27%. Meanwhile, lovastatin in LPMCS co-fermentation extracts (LFE) was qualitatively and quantitatively analyzed by Thin-Layer Chromatography (TLC) and High-Performance Liquid Chromatography (HPLC). Cellular experiments demonstrated that LFE exhibited no obvious cytotoxicity to L-02 cells and exhibited excellent biosafety. Most notably, high-dose LFE (100 mg/L) exhibited the highest reduction of lipid accumulation, total cholesterol, and triglycerides simultaneously in oleic acid-induced L-02 cells, which decreased by 71.59%, 38.64%, and 58.85% than untreated cells, respectively. Overall, LPMCS provides a potential approach to upgrade the lipid-lowering activity of Monascus-fermented products with higher health-beneficial effects.

Statins-From Fungi to Pharmacy.

Statins have been used in the treatment of hyperlipidemia, both as monotherapy and in combination therapy. Natural fermentation processes of fungi such as Monascus spp., Penicillium spp., Aspergillus terreus, and Pleurotus ostreatus have given rise to natural statins. Compactin (mevastatin), the original naturally occurring statin, is the primary biotransformation substrate in the manufacturing process of marketed drugs. Statins are classified into natural, semi-synthetic derivatives of natural statins, and synthetic ones. Synthetic statins differ from natural statins in their structural composition, with the only common feature being the HMG-CoA-like moiety responsible for suppressing HMG-CoA reductase. Statins do not differ significantly regarding their pleiotropic and adverse effects, but their characteristics depend on their pharmacokinetic parameters and chemical properties. This paper focuses on describing the processes of obtaining natural statins, detailing the pharmacokinetics of available statins, divided into natural and synthetic, and indicating their pleiotropic effects.

Lovastatin, an Up-Regulator of Low-Density Lipoprotein Receptor, Enhances Follicular Development in Mouse Ovaries.

Ovarian aging hampers in vitro fertilization in assisted reproductive medicine and has no cure. Lipoprotein metabolism is associated with ovarian aging. It remains unclear how to overcome poor follicular development with aging. Upregulation of the low-density lipoprotein receptor (LDLR) enhances oogenesis and follicular development in mouse ovaries. This study investigated whether upregulation of LDLR expression using lovastatin enhances ovarian activity in mice. We performed superovulation using a hormone and used lovastatin to upregulate LDLR. We histologically analyzed the functional activity of lovastatin-treated ovaries and investigated gene and protein expression of follicular development markers, using RT-qPCR and Western blotting. Histological analysis showed that lovastatin significantly increased the numbers of antral follicles and ovulated oocytes per ovary. The in vitro maturation rate was 10% higher for lovastatin-treated ovaries than for control ovaries. Relative LDLR expression was 40% higher in lovastatin-treated ovaries than in control ovaries. Lovastatin significantly increased steroidogenesis in ovaries and promoted the expression of follicular development marker genes such as anti-Mullerian hormone, Oct3/4, Nanog, and Sox2. In conclusion, lovastatin enhanced ovarian activity throughout follicular development. Therefore, we suggest that upregulation of LDLR may help to improve follicular development in clinical settings. Modulation of lipoprotein metabolism can be used with assisted reproductive technologies to overcome ovarian aging.

Improved Prostate-Specific Membrane Antigen (PSMA) Stimulation Using a Super Additive Effect of Dutasteride and Lovastatin In Vitro.

Prostate-specific membrane antigen (PSMA)-based imaging improved the detection of primary, recurrent and metastatic prostate cancer. However, in certain patients, a low PSMA surface expression can be a limitation for this promising diagnostic tool. Pharmacological induction of PSMA might be useful to further improve the detection rate of PSMA-based imaging. To achieve this, we tested dutasteride (Duta)-generally used for treatment of benign prostatic enlargement-and lovastatin (Lova)-a compound used to reduce blood lipid concentrations. We aimed to compare the individual effects of Duta and Lova on cell proliferation as well as PSMA expression. In addition, we tested if a combination treatment using lower concentrations of Duta and Lova can further induce PSMA expression. Our results show that a treatment with ≤1 µM Duta and ≥1 µM Lova lead to a significant upregulation of whole and cell surface PSMA expression in LNCaP, C4-2 and VCaP cells. Lower concentrations of Duta and Lova in combination (0.5 µM Duta + 0.5 µM Lova or 0.5 µM Duta + 1 µM Lova) were further capable of enhancing PSMA protein expression compared to a single compound treatment using higher concentrations in all tested cell lines (LNCaP, C4-2 and VCaP).

Lovastatin Treatment Inducing Apoptosis in Human Pancreatic Cancer Cells by Inhibiting Cholesterol Rafts in Plasma Membrane and Mitochondria.

Resistance to anticancer drugs is a problem in the treatment of pancreatic ductal carcinoma (PDAC) and overcoming it is an important issue. Recently, it has been reported that statins induce apoptosis in cancer cells but the mechanism has not been completely elucidated. We investigated the antitumor mechanisms of statins against PDAC and their impact on resistance to gemcitabine (GEM). Lovastatin (LOVA) increased mitochondrial oxidative stress in PDAC cells, leading to apoptosis. LOVA reduced lipid rafts in the plasma membrane and mitochondria, suppressed the activation of epithelial growth factor receptor (EGFR) and AKT in plasma membrane rafts, and reduced B-cell lymphoma 2 (BCL2)-Bcl-2-associated X protein (BAX) binding and the translocation of F1F0 ATPase in mitochondrial rafts. In the three GEM-resistant cell lines derived from MIA and PANC1, the lipid rafts in the cell membrane and the mitochondria were increased to activate EGFR and AKT and to increase BCL2-BAX binding, which suppressed apoptosis. LOVA abrogated these anti-apoptotic effects by reducing the rafts in the resistant cells. By treating the resistant cells with LOVA, GEM sensitivity improved to the level of the parental cells. Therefore, cholesterol rafts contribute to drug resistance in PDAC. Further clinical research is warranted on overcoming anticancer drug resistance by statin-mediated intracellular cholesterol regulation.

Pitavastatin and Lovastatin Exhibit Calcium Channel Blocking Activity Which Potentiate Vasorelaxant Effects of Amlodipine: A New Futuristic Dimension in Statin's Pleiotropy.

Background and Objectives: We have recently reported that Fluvastatin, Atorvastatin, Simvastatin and Rosuvastatin have calcium channel antagonistic activities using rabbits' intestinal preparations. The current study is focused on the effects of Pitavastatin and Lovastatin for possible inhibition of vascular L-Type calcium channels, which may have vasorelaxant effect(s). Combined effects of Pitavastatin and Lovastatin in the presence of Amlodipine were also tested for vasorelaxation. Materials and Methods: Possible relaxing effects of Pitavastatin and Lovastatin on 80 mM Potassium chloride (KCL)-induced contractions and on 1 µM norepinephrine (N.E)-induced contractions were studied in isolated rabbit's aortic strips preparations. Relaxing effects on 80 mM KCL-induced vascular contractions were further verified by constructing Calcium Concentration Response Curves (CCRCs), in the absence and presence of three different concentrations of Pitavastatin and Lovastatin using CCRCs as negative control. Verapamil was used as a standard drug that has L-Type calcium channel binding activity. In other series of experiments, we studied drug interaction(s) among Pitavastatin, Lovastatin, and amlodipine. Results: The results of this study imply that Lovastatin is more potent than Pitavastatin for having comparatively lower EC50 (7.44 × 10-5 ± 0.16 M) in intact and (4.55 × 10-5 ± 0.10 M) in denuded aortae for KCL-induced contractions. Lovastatin amplitudes in intact and denuded aortae for KCL-induced contractions were, respectively, 24% and 35.5%; whereas amplitudes for Pitavastatin in intact and denuded aortae for KCL-induced contractions were 34% and 40%, respectively. A left shift in the EC50 values for the statins was seen when we added amlodipine in EC50 (Log Ca++ M). Right shift for CCRCs state that Pitavastatin and Lovastatin have calcium channel antagonistic effects. Lovastatin in test concentration (6.74 × 10-7 M) produced a right shift in relatively lower EC50 (-2.5 ± 0.10) Log Ca++ M as compared to Pitavastatin, which further confirms that lovastatin is relatively more potent. The right shift in EC50 resembles the right shift of Verapamil. Additive effect of Pitavastatin and Lovastatin was noted in presence of amlodipine (p < 0.05). Conclusions: KCL (80 mM)-induced vascular contractions were relaxed by Pitavastatin and Lovastatin via inhibitory effects on L-Type voltage-gated calcium channels. Lovastatin and Pitavastatin also relaxed Norepinephrine (1 µM)-induced contractions giving an insight for involvement of dual mode of action of Pitavastatin and Lovastatin.

Lovastatin enhances chemosensitivity of paclitaxel-resistant prostate cancer cells through inhibition of CYP2C8.

Chemotherapy is the mainstay of treatment for prostate cancer, with paclitaxel being commonly used for hormone-resistant prostate cancer. However, drug resistance often develops and leads to treatment failure in a variety of prostate cancer patients. Therefore, it is necessary to enhance the sensitivity of prostate cancer to chemotherapy. Lovastatin (LV) is a natural compound extracted from Monascus-fermented foods and is an inhibitor of HMG-CoA reductase (HMGCR), which has been approved by the FDA for hyperlipidemia treatment. We have previously found that LV could inhibit the proliferation of refractory cancer cells. Up to now, the effect of LV on chemosensitization and the mechanisms involved have not been evaluated in drug-resistant prostate cancer. In this study, we used prostate cancer cell line PC3 and its paclitaxel-resistant counterpart PC3-TxR as the cell model. Alamar Blue cell viability assay showed that LV and paclitaxel each conferred concentration-dependent inhibition of PC3-TxR cells. When paclitaxel was combined with LV, the proliferation of PC3-TxR cells was synergistically inhibited, as demonstrated by combination index <1. Moreover, colony formation decreased while apoptosis increased in paclitaxel plus LV group compared with paclitaxel alone group. Quantitative RT-PCR showed that the combination of paclitaxel and LV could significantly reduce the expression of CYP2C8, an important drug-metabolizing enzyme. Bioinformatics analysis from the TCGA database showed that CYP2C8 expression was negatively correlated with progression-free survival (PFS) in prostate cancer patients. Our results suggest that LV might increase the sensitivity of resistant prostate cancer cells to paclitaxel through inhibition of CYP2C8 and could be utilized as a chemosensitizer for paclitaxel-resistant prostate cancer cells.

Transcriptome reveals BCAAs biosynthesis pathway is influenced by lovastatin and can act as a potential control target in Phytophthora sojae.

AIMS: Lovastatin has been indicated to impair growth and development of Phytophthora sojae. Therefore, this study was performed to understand the inhibitory mechanism of lovastatin and investigate the metabolic pathway potentially served as a new control target for this plant pathogen. METHODS AND RESULTS: Whole transcriptome analysis of lovastatin-treated P. sojae was performed by RNA-sequencing. The results revealed that 84 genes were upregulated and 58 were downregulated with more than fourfold changes under treatment. Kyoto Encyclopaedia of Genes and Genomes analysis indicated that the branched-chain amino acids (BCAAs) biosynthesis pathway was abundantly enriched. All enzymes in the BCAAs biosynthesis pathway were identified in the P. sojae genome. Moreover, the study found that the herbicide flumetsulam targeting acetohydroxyacid synthase (AHAS) of the BCAAs biosynthesis pathway could effectively inhibit mycelial growth of P. sojae. CONCLUSIONS: Lovastatin treatment significantly influences the BCAAs biosynthesis pathway in P. sojae. Moreover, the herbicide flumetsulam targets AHAS and inhibits growth of P. sojae. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study revealed that BCAAs biosynthesis pathway was influenced by lovastatin treatment and its key enzyme AHAS was identified as a potential new control target, which provides clues for exploring more oomycetes to control plant diseases caused by P. sojae.

AGR2-induced cholesterol synthesis drives lovastatin resistance that is overcome by combination therapy with allicin.

Anterior gradient 2 (AGR2), a protein disulfide isomerase (PDI), is a multifunctional protein under physiological and pathological conditions. In this study we investigated the roles of AGR2 in regulating cholesterol biogenesis, lipid-lowering efficiency of lovastatin as well as in protection against hypercholesterolemia/statin-induced liver injury. We showed that AGR2 knockout significantly decreased hepatic and serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in mice with whole-body or hepatocyte-specific Agr2-null mutant, compared with the levels in their wild-type littermates fed a normal chow diet (NCD) or high-fat diet (HFD). In contrast, mice with AGR2 overexpression (Agr2/Tg) exhibited an increased cholesterol level. Mechanistic studies revealed that AGR2 affected cholesterol biogenesis via activation of AKT/sterol regulatory element-binding protein-2 (SREBP2), to some extent, in a PDI motif-dependent manner. Moreover, elevated AGR2 led to a significant decrease in the lipid-lowering efficacy of lovastatin (10 mg· kg-1· d-1, ip, for 2 weeks) in mice with hypercholesterolemia (hyperCho), which was validated by results obtained from clinical samples in statin-treated patients. We showed that lovastatin had limited effect on AGR2 expression, but AGR2 was inducible in Agr2/Tg mice fed a HFD. Further investigations demonstrated that drug-induced liver toxicity and inflammatory reactions were alleviated in hypercholesterolemic Agr2/Tg mice, suggesting the dual functions of AGR2 in lipid management and hyperCho/statin-induced liver injury. Importantly, the AGR2-reduced lipid-lowering efficacy of lovastatin was attenuated, at least partially, by co-administration of a sulfhydryl-reactive compound allicin (20 mg· kg-1· d-1, ip, for 2 weeks). These results demonstrate a novel role of AGR2 in cholesterol metabolism, drug resistance and liver protection, suggesting AGR2 as a potential predictor for selection of lipid-lowering drugs in clinic.

Genome-Wide Identification and Expression Analysis of Cytokinin Response Regulator (RR) Genes in the Woody Plant Jatropha curcas and Functional Analysis of JcRR12 in Arabidopsis.

The cytokinin (CK) response regulator (RR) gene family plays a pivotal role in regulating the developmental and environmental responses of plants. Axillary bud outgrowth in the perennial woody plant Jatropha curcas is regulated by the crosstalk between CK and gibberellins (GA). In this study, we first analyzed the effects of gibberellin A3 (GA3), lovastatin (a CK synthesis inhibitor), decapitation, and their interaction, on the outgrowth of axillary buds. The results indicate that lovastatin completely inhibited GA-promoted axillary bud outgrowth and partially weakened the decapitation-promoted axillary bud outgrowth. To further characterize and understand the role of CK signaling in promoting the development of female flowers and branches, we performed bioinformatics and expression analyses to characterize the CK RR gene (JcRR) family in J. curcas. A total of 14 members of the JcRR family were identified; these genes were distributed on 10 chromosomes. Phylogenetic analysis indicated that the corresponding RR proteins are evolutionarily conserved across different plant species, and the Myb-like DNA-binding domain divides the 14 members of the JcRR family into type-A and type-B proteins. Further analysis of cis-acting elements in the promoter regions of JcRRs suggests that JcRRs are expressed in response to phytohormones, light, and abiotic stress factors; thus, JcRRs may be involved in some plant development processes. Genomic sequence comparison revealed that segmental duplication may have played crucial roles in the expansion of the JcRR gene family, and five pairs of duplicated genes were all subjected to purifying selection. By analyzing RNA sequencing (RNA-seq) and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) data, we characterized that the temporospatial expression patterns of JcRRs during the development of various tissues and the response of these genes to phytohormones and abiotic stress. The JcRRs were mainly expressed in the roots, while they also exhibited differential expression patterns in other tissues. The expression levels of all six type-A and one type-B JcRRs increased in response to 6-benzylaminopurine (6-BA), while the four type-B JcRRs levels decreased. The expression levels of two type-B JcRRs increased in response to exogenous GA3 treatment, while those of three type-A and three type-B JcRRs decreased. We found that type-A JcRRs may play a positive role in the continuous growth of axillary buds, while the role of type-B JcRRs might be the opposite. In response to abiotic stress, the expression levels of two type-A and three type-B JcRRs strongly increased. The overexpression of JcRR12 in Arabidopsis thaliana slightly increased the numbers of rosette branches after decapitation, but not under normal conditions. In conclusion, our results provide detailed knowledge of JcRRs for further analysis of CK signaling and JcRR functions in J. curcas.