The Selective SIRT3 Inhibitor 3-TYP Represses Primary Myeloma Growth by Reducing c-Myc Stability.

Multiple myeloma is a hematological cancer that can be treated but remains incurable. With the advancement of science and technology, more drugs have been developed for myeloma chemotherapy that greatly improve the quality of life of patients. However, relapse remains a serious problem puzzling patients and doctors. Thus, developing more highly active and specific inhibitors is urgent for myeloma-targeted therapy. In this study, we identified the SIRT3 inhibitor 3-TYP (3-(1H-1,2,3-triazol-4-yl) pyridine) after screening a histone modification compound library, which showed high cytotoxicity and induced DNA damage in myeloma cells. Furthermore, the inhibitory effect of 3-TYP in our xenograft tumor studies also confirmed that compound 3-TYP could inhibit primary myeloma growth by reducing c-Myc protein stability by decreasing c-Myc Ser62 phosphorylation levels. Taken together, the results of our study identified 3-TYP as a novel c-Myc inhibitor, which could be a potential chemotherapeutic agent to target multiple myeloma.

Yeast optimizes metal utilization based on metabolic network and enzyme kinetics.

Metal ions are vital to metabolism, as they can act as cofactors on enzymes and thus modulate individual enzymatic reactions. Although many enzymes have been reported to interact with metal ions, the quantitative relationships between metal ions and metabolism are lacking. Here, we reconstructed a genome-scale metabolic model of the yeast Saccharomyces cerevisiae to account for proteome constraints and enzyme cofactors such as metal ions, named CofactorYeast. The model is able to estimate abundances of metal ions binding on enzymes in cells under various conditions, which are comparable to measured metal ion contents in biomass. In addition, the model predicts distinct metabolic flux distributions in response to reduced levels of various metal ions in the medium. Specifically, the model reproduces changes upon iron deficiency in metabolic and gene expression levels, which could be interpreted by optimization principles (i.e., yeast optimizes iron utilization based on metabolic network and enzyme kinetics rather than preferentially targeting iron to specific enzymes or pathways). At last, we show the potential of using the model for understanding cell factories that harbor heterologous iron-containing enzymes to synthesize high-value compounds such as p-coumaric acid. Overall, the model demonstrates the dependence of enzymes on metal ions and links metal ions to metabolism on a genome scale.

Fine-tuning of p-coumaric acid synthesis to increase (2S)-naringenin production in yeast.

(2S)-Naringenin is a key precursor for biosynthesis of various high-value flavonoids and possesses a variety of nutritional and pharmaceutical properties on human health. Systematic optimization approaches have been employed to improve (2S)-naringenin production in different microbial hosts. However, very few studies have focused on the spatiotemporal distribution of (2S)-naringenin and the related pathway intermediate p-coumaric acid, which is an important factor for efficient production. Here, we first optimized the (2S)-naringenin biosynthetic pathway by alleviating the bottleneck downstream of p-coumaric acid and increasing malonyl-CoA supply, which improved (2S)-naringenin production but significant accumulation of p-coumaric acid still existed extracellularly. We thus established a dual dynamic control system through combining a malonyl-CoA biosensor regulator and an RNAi strategy, to autonomously control the synthesis of p-coumaric acid with the supply of malonyl-CoA. Furthermore, screening potential transporters led to identification of Pdr12 for improved (2S)-naringenin production and reduced accumulation of p-coumaric acid. Finally, a titer of 2.05 g/L (2S)-naringenin with negligible accumulation of p-coumaric acid was achieved in a fed batch fermentation. Our work highlights the importance of systematic control of pathway intermediates for efficient microbial production of plant natural products.

Optimizing yeast for high-level production of kaempferol and quercetin.

BACKGROUND: Two important flavonoids, kaempferol and quercetin possess remarkably potent biological impacts on human health. However, their structural complexity and low abundance in nature make both bulk chemical synthesis and extraction from native plants difficult. Therefore microbial production via heterologous expression of plant enzymes can be a safe and sustainable route for their production. Despite several attempts reported in microbial hosts, the production levels of kaempferol and quercetin still stay far behind compared to many other microbial-produced flavonoids. RESULTS: In this study, Saccharomyces cerevisiae was engineered for high production of kaempferol and quercetin in minimal media from glucose. First, the kaempferol biosynthetic pathway was reconstructed via screening various F3H and FLS enzymes. In addition, we demonstrated that amplification of the rate-limiting enzyme AtFLS could reduce the dihydrokaempferol accumulation and improve kaempferol production. Increasing the availability of precursor malonyl-CoA further improved the production of kaempferol and quercetin. Furthermore, the highest amount of 956 mg L- 1 of kaempferol and 930 mg L- 1 of quercetin in yeast was reached in fed-batch fermentations. CONCLUSIONS: De novo biosynthesis of kaempferol and quercetin in yeast was improved through increasing the upstream naringenin biosynthesis and debugging the flux-limiting enzymes together with fed-batch fermentations, up to gram per liter level. Our work provides a promising platform for sustainable and scalable production of kaempferol, quercetin and compounds derived thereof.

Survival benefit of prophylactic cranial irradiation in limited-stage small-cell lung cancer in modern magnetic resonance imaging staging: a systematic review and meta-analysis.

BACKGROUND: The use of prophylactic cranial irradiation (PCI) in patients suffering from limited-stage small-cell lung cancer (LS-SCLC) remains controversial in modern brain magnetic resonance imaging (MRI) staging. To this end, a systematic review with meta-analysis was hereby performed to investigate the overall survival (OS) in these patients. METHODS: Relevant studies from the PubMed and EMBASE databases were reviewed, and pooled hazard risks were obtained using fixed-effects models. The PRISMA 2020 checklist was used. RESULTS: Fifteen retrospective studies were identified, with a total of 2,797 patients with LS-SCLC included in the analysis, 1,391 of which had received PCI. For all included patients, PCI was associated with improved OS [hazard ratio (HR): 0.64, 95% confidence interval (CI): 0.58-0.70]. The combination of subgroup analysis and sensitivity analysis suggested that the effect of PCI on OS was independent of primary tumor treatment, proportion of complete response (CR), median age, PCI dose, publication years, etc. Additionally, the OS curve of 1,588 patients having undergone thoracic radiotherapy (TRT) as the primary tumor treatment from 8 studies were reconstructed, and the pooled 2-, 3- and 5-year OS rates of limited stage patients were 59% vs. 42%, 42% vs. 29% and 26% vs. 19% (HR: 0.69, 95% CI: 0.61-0.77) in the PCI group and the no PCI group, respectively. Another reconstructed OS curve of 339 patients having undergone radical surgery as the primary tumor treatment from 2 studies presented better results, and the pooled 2-, 3- and 5-year OS rates of in the PCI group and the no PCI group were 85% vs. 71%, 70% vs. 56% and 52% vs. 39% (HR: 0.59, 95% CI: 0.40-0.87), respectively. CONCLUSIONS: This meta-analysis demonstrates a significant beneficial effect of PCI on the OS in patients with LS-SCLC in modern pretreatment MRI staging. However, considering the absence of a strict follow-up of brain MRI recommended by the guideline for the control group from most of the included studies, the superiority of PCI to the treatment strategy of no PCI plus brain MRI surveillance remains unclear.

Comparing the diagnostic performance of radiotracers in prostate cancer biochemical recurrence: a systematic review and meta-analysis.

OBJECTIVES: To systematically assess the early detection rate of biochemical prostate cancer recurrence using choline, fluciclovine, and PSMA. METHODS: Under the guidance of the Preferred Reporting Items for Systematic reviews and Meta-Analysis Diagnostic Test Accuracy guidelines, literature that assessed the detection rates (DRs) of choline, fluciclovine, and PSMA in prostate cancer biochemical recurrence was searched in PubMed and EMBASE databases for our systematic review from 2012 to July 15, 2021. In addition, the PSA-stratified performance of detection positivity was obtained to assess the DRs for various methods, including fluciclovine, PSMA, or choline PET/CT, with respect to biochemical recurrence based on different PSA levels. RESULTS: In total, 64 studies involving 11,173 patients met the inclusion criteria. Of the studies, 12, 7, and 48 focused on choline, fluciclovine, and PSMA, respectively. The pooled DRs were 24%, 37%, and 44%, respectively, for a PSA level less than 0.5 ng/mL (p < 0.001); 36%, 44%, and 60% for a PSA level of 0.5-0.99 ng/mL (p < 0.001); and 50%, 61%, and 80% for a PSA level of 1.0-1.99 ng/mL (p < 0.001). The DR with 18F-labeled PSMA was higher than that with 68Ga-labeled PSMA, and the DR was 58%, 72%, and 88% for PSA levels < 0.5 ng/mL, 0.5-0.9 ng/mL, and 1.0-1.99 ng/mL, respectively. CONCLUSION: The DRs of PSMA-radiotracers were greater than those of choline-radiotracers and fluciclovine-radiotracers at the patient level. 18F-labeled PSMA achieved a higher DR than 68Ga-labeled PSMA. KEY POINTS: • The DRs of PSMA-radiotracers were greater than those of choline-radiotracers and fluciclovine-radiotracers at the patient level. • 18F-labeled PSMA achieved a higher DR than 68Ga-labeled PSMA.

Comparative transcriptome analysis of genomic region deletion strain with enhanced L-tyrosine production in Saccharomyces cerevisiae.

OBJECTIVE: To determine the effect of large genomic region deletion in a Saccharomyces cerevisiae strain on tyrosine yield and to identify new genetic modification targets through transcriptome analysis. RESULTS: TAL was used to produce p-coumaric acid (p-CA) from tyrosine to quantity tyrosine yield. S. cerevisiae mutant strain NK14 with deletion of a 23.8 kb genomic region was identified to have p-CA production of 10.3 mg L- 1, while the wild-type strain BY4741 had p-CA production of 1.06 mg L- 1. Analysis of growth patterns and stress tolerance showed that the deletion did not affect the growth phenotype of NK14. Transcriptome analysis suggested that, compared to BY4741, genes related to glycolysis (ENO2, TKL1) and the tyrosine pathway (ARO1, ARO2, ARO4, ARO7, TYR1) were upregulated in NK14 at different levels. Besides genes related to the tyrosine biosynthetic pathway, amino acid transporters (AVT6, VBA5, THI72) and transcription factor (ARO80) also showed changes in transcription levels. CONCLUSIONS: We developed a strain with improved tyrosine yield and identified new genetic modification candidates for tyrosine production.

IGF-1R Inhibition Suppresses Cell Proliferation and Increases Radiosensitivity in Nasopharyngeal Carcinoma Cells.

Although ionizing radiation (IR) has provided considerable improvements in nasopharyngeal carcinoma (NPC) treatment, radioresistance is still a major threat for some subsets of patients. The insulin-like growth factor-1 receptor (IGF-1R) signaling pathway is tightly regulated and plays critical roles in mediating cell proliferation, growth, and survival. Thus, IGF-1R may be a potential therapeutic target for patients with different malignancies. However, its mechanism in NPC is not fully investigated. Linsitinib is an oral small molecule and is a tyrosine kinase inhibitor (TKI) of IGF-1R, which has been known for antitumor effects used widely. Here, we evaluated the proliferation and radiosensitivity of NPC cell lines (CNE-2 and SUNE-1) after linsitinib treatment. We found that linsitinib suppresses IGF-1-induced cell proliferation through inhibiting Akt and ERK phosphorylation. Moreover, linsitinib further boosted IR-induced DNA damage, G2-M cell cycle delay, and apoptosis in NPC cells. Finally, linsitinib reversed radioresistant NPC cells by decreasing the phosphorylation of IGF-1R. Our data indicated that the combination of linsitinib and IR and targeting IGF-1R by linsitinib could be a promising therapeutic strategy for NPC.

POT1-mediated δ-integration strategy for high-copy, stable expression of heterologous proteins in Saccharomyces cerevisiae.

In biotechnological industry, increased expression cassette stability and copy number serve as important means of maintaining consistently high production levels of heterologous proteins in Saccharomyces cerevisiae. In this study, we combined δ sequences for site-specific integration with TPI1 gene from Schizosaccharomyces pombe (POT1) as a selection marker to realize high-copy integration and stable expression of heterologous proteins in S. cerevisiae. With the newly developed POT1 platform, a 32-copy integration of enhanced green fluorescent protein (EGFP) expression cassette was obtained in a single round and was stably maintained after 100 generations of growth in a rich complex medium. Talaromyces emersonii cellobiohydrolase I gene was synthesized with S. cerevisiae codon bias and expressed under the control of TPI1 promoter and terminator via POT1-mediated δ-integration; the highest specific activity yielded 238 mU g-1 of dry cell weight when p-nitrophenyl-ß-D-cellobioside was used as substrate, whereas the highest activity in cellulose hydrolysis reached 67% Avicel conversion. POT1-mediated δ-integration produces high protein levels over a wide dynamic range and enables broad applications in metabolic engineering and synthetic biology.

Combinatorial analysis of enzymatic bottlenecks of L-tyrosine pathway by p-coumaric acid production in Saccharomyces cerevisiae.

OBJECTIVE: To identify new enzymatic bottlenecks of L-tyrosine pathway for further improving the production of L-tyrosine and its derivatives. RESULT: When ARO4 and ARO7 were deregulated by their feedback resistant derivatives in the host strains, the ARO2 and TYR1 genes, coding for chorismate synthase and prephenate dehydrogenase were further identified as new important rate-limiting steps. The yield of p-coumaric acid in the feedback-resistant strain overexpressing ARO2 or TYR1, was significantly increased from 6.4 to 16.2 and 15.3 mg l-1, respectively. Subsequently, we improved the strain by combinatorial engineering of pathway genes increasing the yield of p-coumaric acid by 12.5-fold (from 1.7 to 21.3 mg l-1) compared with the wild-type strain. Batch cultivations revealed that p-coumaric acid production was correlated with cell growth, and the formation of by-product acetate of the best producer NK-M6 increased to 31.1 mM whereas only 19.1 mM acetate was accumulated by the wild-type strain. CONCLUSION: Combinatorial metabolic engineering provides a new strategy for further improvement of L-tyrosine or other metabolic biosynthesis pathways in S. cerevisiae.

Cellular iron homeostasis mediated by the Mrs4-Ccc1-Smf3 pathway is essential for mitochondrial function, morphogenesis and virulence in Candida albicans.

Iron bioavailability is crucial for mitochondrial metabolism and biosynthesis. Dysregulation of cellular iron homeostasis affects multiple aspects of mitochondrial physiology and cellular processes. However, the intracellular iron trafficking pathway in Candida albicans remains unclear. In this study, we characterized the Mrs4-Ccc1-Smf3 pathway, and demonstrated its important role in maintaining cellular iron levels. Double deletion of vacuolar iron exporter SMF3 and mitochondrial iron transporter MRS4 further elevated cellular iron levels in comparison with the single MRS4 deletion. However, deletion of vacuolar iron importer CCC1 in the mrs4delta/delta mutant restored cellular iron homeostasis to normal wild-type levels, and also normalized most of the defective phenotypes in response to various environmental stresses. Our results also suggested that both Mrs4 and Cccl contributed to the maintenance of mitochondrial function. The mrs4delta/delta and mrs4delta/deltasmf3delta/delta mutants exhibited an obvious decrease in aconitase activities and mitochondrial membrane potential, whereas deletion of CCC1 in the mrs4delta/delta mutant effectively rescued these defects. Furthermore, we also found that the Mrs4-Ccc1-Smf3 pathway was indispensable for cell-wall stability, antifungal drug tolerance, filamentous growth and virulence, supporting the novel viewpoint that mitochondria might be the promising target for better antifungal therapies. Interestingly, the addition of exogenous iron failed to rescue the defects on non-fermentable carbon sources or hyphae-inducing medium, indicating that the defects in mitochondrial respiration and filamentous development might result from the disturbance of cellular iron homeostasis rather than environmental iron deprivation. Taken together, our results propose the Mrs4-Ccc1-Smf3 pathway as a potentially attractive target for antifungal drug development.

Deletion of genes encoding fatty acid desaturases leads to alterations in stress sensitivity in Pichia pastoris.

Unsaturated fatty acids (UFAs) are key compounds which have important roles in maintaining cell membrane physiological functions and the adaption to tough conditions. Defects of fatty acid desaturases will change cellular UFA constitution. Pichia pastoris GS115 has four fatty acid desaturase genes, namely FAD9A, FAD9B, FAD12 and FAD15. Their products catalyze the synthesis of three kinds of UFAs, oleic acid (catalyzed by Fad9A and Fad9B), linoleic acid (catalyzed by Fad12) and α-linolenic acid (catalyzed by Fad15), respectively. In this study, we found that deletion of FAD12 led to increased resistance to oxidative stress. Cellular lipid peroxidation levels declined in the fad12Δ mutant upon H2O2 treatment. Cellular fatty acids compositions were changed with the increased expression of FAD9A. On the other hand, deletion of FAD9A resulted in increased tolerance to the plasma membrane (PM) damage agent SDS, and PM deformation was not detected in the fad9AΔ mutant under this stress. Our results showed that UFAs are related to cell adaption to adverse environmental changes.

Inhibitory effect of verapamil on Candida albicans hyphal development, adhesion and gastrointestinal colonization.

Candida albicans morphogenesis and gastrointestinal colonization are closely associated with the pathogenicity of this pathogen. This study investigated the in vitro and in vivo effect of verapamil, a calcium channel blocker, on these processes. Exposure to ≥ 10 µg mL(-1) verapamil led to a significant decrease of C. albicans hyphal cells. The ability to adhere to a polystyrene surface and buccal epithelial cells was inhibited by exposure to ≥ 20 µg mL(-1) verapamil. Detection of the Hwp1-green fluorescent protein fusion protein showed that verapamil inhibited expression and transport of Hwp1, indicating its activity against both the regulation network of morphogenesis-associated proteins and the secretory pathway in C. albicans. Moreover, treatment with verapamil at 10 mg (kg day)(-1) led to a remarkable decrease in gastrointestinal-colonizing fungal cells. This study revealed the inhibitory effect of verapamil on C. albicans hyphal development, adhesion and gastrointestinal colonization, which is relevant to decreased expression and abnormal transport of the proteins required for morphogenesis. Therefore, verapamil may be taken into account when choosing an antifungal therapy against C. albicans colonization and infection.

The efficacy of stereotactic radiotherapy followed by bevacizumab and temozolomide in the treatment of recurrent glioblastoma: a case report.

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor among adults. Despite advancements in multimodality therapy for GBM, the overall prognosis remains poor, with an extremely high risk of recurrence. Currently, there is no established consensus on the optimal treatment option for recurrent GBM, which may include reoperation, reirradiation, chemotherapy, or a combination of the above. Bevacizumab is considered a first-line treatment option for recurrent GBM, as is temozolomide. However, in recurrent GBM, it is necessary to balance the risks and benefits of reirradiation in combination with bevacizumab and temozolomide. Herein, we report the case of a patient with recurrent GBM after standard treatment who benefited from stereotactic radiotherapy followed by bevacizumab and temozolomide maintenance therapy. Following 16 months of concurrent chemoradiotherapy (CCRT), the patient was diagnosed with recurrent GBM by a 3-T contrast-enhanced magnetic resonance imaging (MRI). The addition of localized radiotherapy to the ongoing treatment regimen of bevacizumab, in combination with temozolomide therapy, prolonged the patient's disease-free survival to over 2 years, achieving a significant long-term outcome, with no notable adverse effects observed. This clinical case may provide a promising new option for patients with recurrent GBM.

Nitrogen removal capability and mechanism of a novel low-temperature-tolerant simultaneous nitrification-denitrification bacterium Acinetobacter kyonggiensis AKD4.

A low-temperature-tolerant simultaneous nitrification-denitrification bacterial strain of Acinetobacter kyonggiensis (AKD4) was identified. It showed high efficiency in total nitrogen (TN) removal (92.45% at 10°C and 87.51% at 30°C), indicating its excellent low-temperature tolerance. Transcriptomic analysis revealed possible metabolic mechanisms under low-temperature stress. Genes involved in cell growth, including ATP synthase (atpADGH), amino acid (glyA, dctA, and ilvE), and TCA cycle metabolism (gltA, fumC, and mdh) were remarkably upregulated from 1.05-3.44-fold at 10°C, suggesting that their actions enhance survivability at low temperatures. The expression levels of genes associated with nitrogen assimilation (glnAE, gltBD, and gdhA), nitrogen metabolism regulation (ntrC, glnB, and glnD), and denitrification processes (napA) were increased from 1.01-4.38-fold at 10°C, which might have contributed to the bacterium's highly efficient nitrogen removal performance at low temperatures. Overall, this study offers valuable insights into transcriptome, and enhances the comprehension of the low-temperature-tolerant mechanism of simultaneous nitrification and denitrification processes.

Relieving metabolic burden to improve robustness and bioproduction by industrial microorganisms.

Metabolic burden is defined by the influence of genetic manipulation and environmental perturbations on the distribution of cellular resources. The rewiring of microbial metabolism for bio-based chemical production often leads to a metabolic burden, followed by adverse physiological effects, such as impaired cell growth and low product yields. Alleviating the burden imposed by undesirable metabolic changes has become an increasingly attractive approach for constructing robust microbial cell factories. In this review, we provide a brief overview of metabolic burden engineering, focusing specifically on recent developments and strategies for diminishing the burden while improving robustness and yield. A variety of examples are presented to showcase the promise of metabolic burden engineering in facilitating the design and construction of robust microbial cell factories. Finally, challenges and limitations encountered in metabolic burden engineering are discussed.

Prediction by a multiparametric magnetic resonance imaging-based radiomics signature model of disease-free survival in patients with rectal cancer treated by surgery.

Objective: The aim of this study was to assess the ability of a multiparametric magnetic resonance imaging (MRI)-based radiomics signature model to predict disease-free survival (DFS) in patients with rectal cancer treated by surgery. Materials and methods: We evaluated data of 194 patients with rectal cancer who had undergone radical surgery between April 2016 and September 2021. The mean age of all patients was 62.6 ± 9.7 years (range: 37-86 years). The study endpoint was DFS and 1132 radiomic features were extracted from preoperative MRIs, including contrast-enhanced T1- and T2-weighted imaging and apparent diffusion coefficient values. The study patients were randomly allocated to training (n=97) and validation cohorts (n=97) in a ratio of 5:5. A multivariable Cox regression model was used to generate a radiomics signature (rad score). The associations of rad score with DFS were evaluated using Kaplan-Meier analysis. Three models, namely a radiomics nomogram, radiomics signature, and clinical model, were compared using the Akaike information criterion. Result: The rad score, which was composed of four MRI features, stratified rectal cancer patients into low- and high-risk groups and was associated with DFS in both the training (p = 0.0026) and validation sets (p = 0.036). Moreover, a radiomics nomogram model that combined rad score and independent clinical risk factors performed better (Harrell concordance index [C-index] =0.77) than a purely radiomics signature (C-index=0.73) or clinical model (C-index=0.70). Conclusion: An MRI radiomics model that incorporates a radiomics signature and clinicopathological factors more accurately predicts DFS than does a clinical model in patients with rectal cancer.

Construction of brain metastasis prediction model in limited stage small cell lung cancer patients without prophylactic cranial irradiation.

INTRODUCTION: Small cell lung cancer (SCLC) is a highly aggressive lung cancer variant known for its elevated risk of brain metastases (BM). While earlier meta-analyses supported the use of prophylactic cranial irradiation (PCI) to reduce BM incidence and enhance overall survival, modern MRI capabilities raise questions about PCI's universal benefit for limited-stage SCLC (LS-SCLC) patients. As a response, we have created a predictive model for BM, aiming to identify low-risk individuals who may not require PCI. METHODS: A total of 194 LS-SCLC patients without PCI treated between 2009 and 2021 were included. We conducted both univariate and multivariate analyses to pinpoint the factors associated with the development of BM. A nomogram for predicting the 2- and 3-year probabilities of BM was then constructed. RESULTS: Univariate and multivariate analyses revealed several significant independent risk factors for the development of BM. These factors include TNM stage, the number of chemotherapy (ChT) cycles, Ki-67 expression level, pretreatment serum lactate dehydrogenase (LDH) levels, and haemoglobin (HGB) levels. These findings underscore their respective roles as independent predictors of BM. Based on the results of the final multivariable analysis, a nomogram model was created. In the training cohort, the nomogram yielded an area under the receiver operating characteristic curve (AUC) of 0.870 at 2 years and 0.828 at 3 years. In the validation cohort, the AUC values were 0.897 at 2 years and 0.789 at 3 years. The calibration curve demonstrated good agreement between the predicted and observed probabilities of BM. CONCLUSIONS: A novel nomogram has been developed to forecast the likelihood of BM in patients diagnosed with LS-SCLC. This tool holds the potential to assist healthcare professionals in formulating more informed and tailored treatment plans.

Optimization of Pinocembrin Biosynthesis in Saccharomyces cerevisiae.

The flavonoid pinocembrin and its derivatives have gained increasing interest for their benefits on human health. While pinocembrin and its derivatives can be produced in engineered Saccharomyces cerevisiae, yields remain low. Here, we describe novel strategies for improved de novo biosynthesis of pinocembrin from glucose based on overcoming existing limitations in S. cerevisiae. First, we identified cinnamic acid as an inhibitor of pinocembrin synthesis. Second, by screening for more efficient enzymes and optimizing the expression of downstream genes, we reduced cinnamic acid accumulation. Third, we addressed other limiting factors by boosting the availability of the precursor malonyl-CoA, while eliminating the undesired byproduct 2',4',6'-trihydroxy dihydrochalcone. After optimizing cultivation conditions, 80 mg/L pinocembrin was obtained in a shake flask, the highest yield reported for S. cerevisiae. Finally, we demonstrated that pinocembrin-producing strains could be further engineered to generate 25 mg/L chrysin, another interesting flavone. The strains generated in this study will facilitate the production of flavonoids through the pinocembrin biosynthetic pathway.

Effect of anlotinib combined with ticeorgio for recurrent nasopharyngeal carcinoma: a case report.

For patients with locally unresectable recurrent nasopharyngeal carcinoma who relapsed after 2 years of radiotherapy, re-radiotherapy is also the preferred treatment. However, for patients relapsed within 2 years, the use of re-radiotherapy would be greatly limited by its adverse effects. Consequently, finding a new strategy to prolong the time of re-radiotherapy for locally recurrent nasopharyngeal carcinoma is very necessary to reduce the related side effects and improve the curative effect. Anlotinib is an orally available small molecule multi-target tyrosine kinase inhibitor that primarily inhibits VEGFR2/3, FGFR1-4, PDGFR α/ß, c-Kit, and Ret. However, whether recurrent nasopharyngeal carcinoma patients can be treated with anlotinib combined with ticeorgio (also called S-1) remains unknown. Herein, we report a nasopharyngeal carcinoma patient with local recurrence after radical radiotherapy who benefited from combination treatment of anlotinib with ticeorgio.