BYL719 reverses gefitinib-resistance induced by PI3K/AKT activation in non-small cell lung cancer cells.

Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation often obtain de novo resistance or develop secondary resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs), which restricts the clinical benefit for the patients. The activation of phosphatidylinositol 3-kinase (PI3K)/AKT signal pathway is one of the most important mechanisms for the EGFR-TKIs resistance beyond T790M mutation. There are currently no drugs simultaneously targeting EGFR and PI3K signal pathways, and combination of these two pathway inhibitors may be a possible strategy to reverse theses resistances. To test whether this combinational strategy works, we investigated the therapeutic effects and mechanisms of combining BYL719, a PI3Kα inhibitor, with gefitinib, an EGFR-TKI inhibitor in EGFR-TKIs resistance NSCLC models induced by PI3K/AKT activation. Our results demonstrated that PIK3CA mutated cells showed increased growth rate and less sensitive or even resistant to gefitinib, associated with increased PI3K/AKT expression. The combination of BYL719 and gefitinib resulted in synergistic effect compared with the single agents alone in EGFR-mutated NSCLC cells with PI3K/AKT activation. The inhibition of AKT phosphorylation by BYL719 increased the antitumor efficacy of gefitinib in these cell lines. Moreover, the combined effect and mechanism of gefitinib and BYL719 were also confirmed in the NSCLC cells and patient-derived organoids under 3D culture condition, as well as in vivo. Taken together, the data indicate that PIK3CA mutation induces more aggressive growth and gefitinib resistance in NSCLC cells, and the combination treatment with gefitinib and BYL719 is a promising therapeutic approach to overcoming EGFR-TKIs resistance induced by PI3K/AKT activation.

Retracted: Effect of Sham Acupuncture on Chronic Pain: A Bayesian Network Meta-Analysis.

BACKGROUND: Along with increasing research on acupuncture for chronic pain, the validity of sham acupuncture (SA) has also been argued. METHODS: Nine databases were searched for randomized controlled trials (RCTs) from the inception dates of the databases to July 5, 2022. With Markov Chain Monte Carlo methods, a Bayesian multiple-treatment network meta-analysis (NMA) with random-effects model was conducted. RESULTS: A total of 62 RCTs with 6,806 patients and four kinds of treatments (real acupuncture [RA], non-acupuncture [NA], penetrative SA [PSA], and non-penetrative SA [NPSA]) were included. The results indicated that both NPSA and PSA were not superior to NA in improving chronic pain (NPSA: mean difference [MD]= -4.77, 95% confidence interval [CI] -11.09 to 1.52; PSA: MD= -4.96, 95% CI -10.38 to 0.48). After NPSA and PSA were combined into the SA group, the weak trend of pain relief from SA was still not statistically significant (MD= -4.91, 95% CI -9.93 to 0.05). NPSA and PSA had similar effects (MD= 0.18, 95% CI -5.45 to 5.81). RA was significantly associated with pain relief, compared with NPSA and PSA (NPSA: MD= -12.03, 95% CI -16.62 to -7.41; PSA: MD= -11.85, 95% CI -15.48 to -8.23). The results were generally consistent regardless of pain phenotype, frequency, duration, acupuncture methods, analgesic intake, or detection bias. CONCLUSION: These results suggested that acupuncture was significantly associated with reduced chronic pain. The two kinds of placebo acupuncture, NPSA and PSA, have similar effects. Both NPSA and PSA, with a weak but not significant effect, are appropriate to be inert placebo controls in RCTs for chronic pain.

Solamargine inhibits the growth of hepatocellular carcinoma and enhances the anticancer effect of sorafenib by regulating HOTTIP-TUG1/miR-4726-5p/MUC1 pathway.

Hepatocellular carcinoma (HCC) is one of the most common primary malignancies. Drug resistance has significantly prevented the clinical application of sorafenib (SF), a first-line targeted medicine for the treatment of HCC. Solamargine (SM), a natural alkaloid, has shown potential antitumor activity, but studies about antitumor effect of SM are obviously insufficient in HCC. In the present study, we found that SM significantly inhibited the growth of HCC and enhanced the anticancer effect of SF. In brief, SM significantly inhibited the growth of HepG2 and Huh-7 cells. The combination of SM and SF showed a synergistic antitumor effect. Mechanistically, SM downregulated the expression of long noncoding RNA HOTTIP and TUG1, followed by increasing the expression of miR-4726-5p. Moreover, miR-4726-5p directly bound to the 3'-UTR region of MUC1 and decreased the expression of MUC1 protein. Overexpression of MUC1 partially reversed the inhibitory effect of SM on HepG2 and Huh-7 cells viability, which suggested that MUC1 may be the key target in SM-induced growth inhibition of HCC. More importantly, the combination of SM and SF synergistically restrained the expression of MUC1 protein. Taken together, our study revealed that SM inhibited the growth of HCC and enhanced the anticancer effect of SF through HOTTIP-TUG1/miR-4726-5p/MUC1 signaling pathway. These findings will provide potential therapeutic targets and strategies for the treatment of HCC.

Comparative efficacy and safety of first-line treatments for advanced non-small cell lung cancer with ALK-rearranged: a meta-analysis of clinical trials.

BACKGROUND: Whereas there are many pharmacological interventions prescribed for patients with advanced anaplastic lymphoma kinase (ALK)- rearranged non-small cell lung cancer (NSCLC), comparative data between novel generation ALK-tyrosine kinase inhibitors (TKIs) remain scant. Here, we indirectly compared the efficacy and safety of first-line systemic therapeutic options used for the treatment of ALK-rearranged NSCLC. METHODS: We included all phase 2 and 3 randomised controlled trials (RCTs) comparing any two or three treatment options. Eligible studies reported at least one of the following outcomes: progression free survival (PFS), overall survival (OS), objective response rate (ORR), or adverse events of grade 3 or higher (Grade ≥ 3 AEs). Subgroup analysis was conducted according to central nervous system (CNS) metastases. RESULTS: A total of 9 RCTs consisting of 2484 patients with 8 treatment options were included in the systematic review. Our analysis showed that alectinib (300 mg and 600 mg), brigatinib, lorlatinib and ensartinib yielded the most favorable PFS. Whereas there was no significant OS or ORR difference among the ALK-TKIs. According to Bayesian ranking profiles, lorlatinib, alectinib 600 mg and alectinib 300 mg had the best PFS (63.7%), OS (35.9%) and ORR (37%), respectively. On the other hand, ceritinib showed the highest rate of severe adverse events (60%). CONCLUSION: Our analysis indicated that alectinib and lorlatinib might be associated with the best therapeutic efficacy in first-line treatment for major population of advanced NSCLC patients with ALK-rearrangement. However, since there is little comparative evidence on the treatment options, there is need for relative trials to fully determine the best treatment options as well as the rapidly evolving treatment landscape.

The most recent progress of baicalein in its anti-neoplastic effects and mechanisms.

Problems, such as toxic side effects and drug resistance of chemoradiotherapy, target therapy and immunotherapy accompanying the current anti-cancer treatments, have become bottlenecks limiting the clinical benefit for patients. Therefore, it is urgent to find promising anti-cancer strategies with higher efficacy and lesser side effects. Baicalein, a flavonoid component derived from the Chinese medicine scutellaria baicalensis, has been widely studied for its remarkable anti-cancer activity in multiple types of malignancies both at the molecular and cellular levels. Baicalein exerts its anti-tumor effects by inhibiting angiogenesis, invasion and migration, inducing cell apoptosis and cell cycle arrest, as well as regulating cell autophagy, metabolism, the tumor microenvironment and cancer stem cells with no obvious toxic side effects. The role of classic signaling pathways, such as PI3K/AKT/mTOR, MAPK, AMPK, Wnt/ß-catenin, JAK/STAT3, MMP-2/-9, have been highlighted as the major targets for baicalein exerting its anti-malignant potential. Besides, baicalein can regulate the relevant non-coding RNAs, such as lncRNAs, miRNAs and circ-RNAs, to inhibit tumorigenesis and progression. In addition to the mentioned commonalities, baicalein shows some specific anti-tumor characteristics in some specific cancer types. Moreover, the preclinical studies of the combination of baicalein and chemoradiotherapy pave the way ahead for developing baicalein as an adjunct treatment with chemoradiotherapy. Our aim is to summary the role of baicalein in different types of cancer with its mechanisms based on in vitro and in vivo experiments, hoping providing proof for baicalein serving as an effective and safe compound for cancer treatment in clinic in the future.

Non-target and target quantitative metabolomics with quantitative aroma evaluation reveal the influence mechanism of withering light quality on tea aroma and volatile metabolites evolution.

Withering is the first and key process that influences tea quality, with light quality being a key regulatory factor. However, effects of withering light quality (WLQ) on transformation and formation pathways of tea aroma and volatile metabolites (VMs) remain unclear. In the present study, four WLQs were set up to investigate their effects on tea aroma and VMs. The results showed that blue and red light reduced the grassy aroma and improved the floral and fruity aroma of tea. Based on GC-MS/MS, 83 VMs were detected. Through VIP, significant differences, and OAV analysis, 13 key differential VMs were screened to characterize the differential impacts of WLQ on tea aroma. Further analysis of the evolution and metabolic pathways revealed that glycoside metabolism was the key pathway regulating tea aroma through WLQ. Blue light withering significantly enhanced glycosides hydrolysis and amino acids deamination, which was beneficial for the enrichment of floral and fruity VMs, such as geraniol, citral, methyl salicylate, 2-methyl-butanal, and benzeneacetaldehyde, as well as the transformation of grassy VMs, such as octanal, naphthalene, and cis-3-hexenyl isovalerate, resulting in the formation of tea floral and fruity aroma. The results provide theoretical basis and technical support for the targeted processing of high-quality tea.

Objective quantification technique and widely targeted metabolomic reveal the effect of drying temperature on sensory attributes and related non-volatile metabolites of black tea.

Drying temperature (DT) considerably affects the flavor of black tea (BT); however, its influence on non-volatile metabolites (NVMs) and their correlations remain unclear. In this study, an objective quantification technique and widely targeted metabolomics were applied to explore the effects of DT (130 °C, 110 °C, 90 °C, and 70 °C) on BT flavor and NVMs conversion. BT with a DT of 90 °C presented the highest umami, sweetness, overall taste, and brightness color values. Using the weighted gene co-expression network and multiple factor analysis, 455 sensory trait-related NVMs were explored across six key modules. Moreover, 169 differential NVMs were screened, and flavonoids, phenolic acids, amino acids, organic acids, and lipids were identified as key differential NVMs affecting the taste and color attributes of BT in response to DT. These findings enrich the BT processing theory and offer technical support for the precise and targeted processing of high-quality BT.

Tanreqing injection inhibits stemness and enhances sensitivity of non-small cell lung cancer models to gefitinib through ROS/STAT3 signaling pathway.

Resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has emerged as a significant obstacle in managing patients with EGFR-mutant non-small-cell lung cancer (NSCLC), necessitating the exploration of novel therapeutic approaches. Tanreqing injection (TRQ) is a kind of Chinese patent medicine known for its heat-clearing and detoxifying properties. Studies have shown a correlation between tumor drug resistance and enrichment of cancer stem cells (CSCs). We aim to investigate the feasibility of TRQ enhancing sensitivity to gefitinib by targeting CSCs and reactive oxygen species (ROS). In our study, TRQ significantly inhibited cell proliferation in gefitinib-resistant non-small-cell lung cancer (NSCLC) models including 2D cell lines, 3D cell spheres, tumor-bearing animal and organoids. Compared with the gefitinib group alone, addition of TRQ elevated ROS levels, attenuated upregulation of the protein levels of sex-determining region Y-box 2 (SOX2) and aldehyde dehydrogenase 1 family member A1 (ALDH1A1) induced by gefitinib treatment, and inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3). Scavenging ROS could restore tumor stemness, attenuate the inhibitory effect on the phosphorylation of STAT3, and promote cell proliferation. These results suggested that TRQ could enhance sensitivity of NSCLC models to gefitinib, providing a new combined treatment strategy.

Reprogramming of glucose metabolism: The hallmark of malignant transformation and target for advanced diagnostics and treatments.

Reprogramming of cancer metabolism has become increasingly concerned over the last decade, particularly the reprogramming of glucose metabolism, also known as the "Warburg effect". The reprogramming of glucose metabolism is considered a novel hallmark of human cancers. A growing number of studies have shown that reprogramming of glucose metabolism can regulate many biological processes of cancers, including carcinogenesis, progression, metastasis, and drug resistance. In this review, we summarize the major biological functions, clinical significance, potential targets and signaling pathways of glucose metabolic reprogramming in human cancers. Moreover, the applications of natural products and small molecule inhibitors targeting glucose metabolic reprogramming are analyzed, some clinical agents targeting glucose metabolic reprogramming and trial statuses are summarized, as well as the pros and cons of targeting glucose metabolic reprogramming for cancer therapy are analyzed. Overall, the reprogramming of glucose metabolism plays an important role in the prediction, prevention, diagnosis and treatment of human cancers. Glucose metabolic reprogramming-related targets have great potential to serve as biomarkers for improving individual outcomes and prognosis in cancer patients. The clinical innovations related to targeting the reprogramming of glucose metabolism will be a hotspot for cancer therapy research in the future. We suggest that more high-quality clinical trials with more abundant drug formulations and toxicology experiments would be beneficial for the development and clinical application of drugs targeting reprogramming of glucose metabolism.This review will provide the researchers with the broader perspective and comprehensive understanding about the important significance of glucose metabolic reprogramming in human cancers.

Xie-Bai-San increases NSCLC cells sensitivity to gefitinib by inhibiting Beclin-1 mediated autophagosome formation.

BACKGROUND: Autophagy, a cellular process involving lysosomal self-digestion, plays a crucial role in recycling biomolecules and degrading dysfunctional proteins and damaged organelles. However, in non-small cell lung cancer (NSCLC), cancer cells can exploit autophagy to survive metabolic stress and develop resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), which reduce treatment efficacies. Currently, most studies have found that late-stage autophagy inhibitors can hinder EGFR-TKIs resistance, while research on early-stage autophagy inhibitors is still limited. PURPOSE: This study investigates the mechanism via which the Xie-Bai-San (XBS) formula enhances NSCLC cell sensitivity to gefitinib, revealing the relationship between XBS-induced cell death and the inhibition of autophagosome formation. METHODS: Cell viability was assessed using CCK-8 and EdU assays, lentivirus transfection was utilized to generate PC9 cells harboring the PIK3CA E545K mutation (referred to as PC9-M), autophagic flux was monitored using mCherry-GFP-LC3 adenovirus. Protein expression and colocalization were observed through immunofluorescence staining. The interaction between Bcl-2 and Beclin-1 in PC9-GR and PC9-M cells was determined via co-immunoprecipitation (Co-IP) assay, cell apoptosis was assessed by flow cytometry and PI staining, and overall survival analysis of lung adenocarcinoma patients was conducted using the TCGA database. In vivo experiments included a patient-derived xenograft (PDX) model with EGFR and PIK3CA mutations and subcutaneous mice xenografts of NSCLC cell lines (PC9 and PC9-GR). In addition, autophagic vesicles in mouse tumor tissues were observed via transmission electron microscopy analysis. RESULTS: XBS effectively inhibits the proliferation of gefitinib-resistant NSCLC cells and induces apoptosis both in vitro and in vivo. Mechanistically, XBS suppresses gefitinib-induced autophagic flux by inhibiting autophagy through the upregulation of p-mTOR and Bcl-2 and downregulation of Beclin-1. Additionally, XBS enhances the interaction between Bcl-2 and Beclin-1, and the overexpression of Beclin-1 promotes NSCLC cell proliferation and counteracts XBS-induced cell death, while XBS demonstrates minimal impact on autophagosome-lysosome fusion or lysosome function. CONCLUSION: This study reveals a novel role for the XBS formula in impeding autophagy initiation and demonstrates its potential as a candidate drug to counteract autophagy-induced treatment resistance in NSCLC.

Investigation of non-volatile metabolite variations during round green tea processing and effect of pan-frying degree using untargeted metabolomics and objective quantification.

Round green tea (RGT) presents unique properties and is widely distributed in China, and during processing, it undergoes dynamic changes in non-volatile metabolites (NVMs), which are poorly understood. Utilizing UHPLC-Q-Exactive/MS analysis, this study comprehensively characterized 216 NVMs during RGT processing and identified fixation and pan-frying as key processes influencing NVMs. Additionally, 23 key differential NVMs were screened, with amino acid and flavonoid metabolism highlighted as key metabolic pathways for RGT taste and color quality. The impact of pan-frying degree on shape, color, and taste was also explored. Moderate pan-frying led to optimal results, including a tight and round shape, green and bright color, mellow and umami taste, and reduced astringent and bitter taste NVMs, including epigallocatechin gallate, procyanidin B2, myricetin 3-O-galactoside, quinic acid, strictinin, phenylalanine, and theobromine. This study addresses the NVM research gap in RGT processing, thus providing a technical foundation for the precision-oriented processing of high-quality tea.

Construction of Mn-N-C nanoparticles with multienzyme-like properties and photothermal performance for the effective treatment of bacterial infections.

In this work, we successfully constructed Mn-coordinated nitrogen-carbon nanoparticles (Mn-N-C NPs) exhibiting multienzyme-like activities. In a bacterial infectious microenvironment, the POD-like and OXD-like activities of Mn-N-C NPs could synergistically trigger the generation of ROS (˙OH and O2˙-), causing oxidative damage to the bacterial cell membrane for killing bacteria. Alternatively, in neutral or weak alkaline normal tissues, the excessive O2˙- could be converted into O2 and H2O2via the SOD-like ability of Mn-N-C NPs, and subsequently their CAT-like activity catalyzed excess H2O2 into H2O and O2 for protecting normal cells through the antioxidant defense. Mn-N-C NPs also possessed a good NIR-photothermal performance, which could enhance their POD-like and OXD-like activities. Furthermore, Mn-N-C NPs could facilitate the GSH oxidation process and disrupt the intrinsic balance in the bacterial protection microenvironment with the assistance of H2O2, which is beneficial for rapid bacterial death. Undoubtedly, the Mn-N-C NPs + H2O2 system showed the highest antibacterial activity when irradiated with an 808 nm laser, destroying the bacterial membrane and causing the efflux of proteins. Moreover, the Mn-N-C NPs + H2O2 system was immune to the development of bacterial resistance and could efficiently disrupt the formation of a bacterial biofilm with negligible cytotoxicity and low hemolysis ratio. Finally, Mn-N-C NPs exhibited an excellent antibacterial performance in vivo and could accelerate wound healing without cellular inflammation production. Therefore, due to their significant therapeutic effects, Mn-N-C NPs show great potential in fighting antibiotic-resistant bacteria.

Biocompatible N-carbazoleacetic acid decorated CuxO nanoparticles as self-cascading platforms for synergistic single near-infrared triggered phototherapy treating microbial infections.

In this work, positively charged N-carbazoleacetic acid decorated CuxO nanoparticles (CuxO-CAA NPs) as novel biocompatible nanozymes have been successfully prepared through a one-step hydrothermal method. CuxO-CAA can serve as a self-cascading platform through effective GSH-OXD-like and POD-like activities, and the former can induce continuous generation of H2O2 through the catalytic oxidation of overexpressed GSH in the bacterial infection microenvironment, which in turn acts as a substrate for the latter to yield ˙OH via Fenton-like reaction, without introducing exogenous H2O2. Upon NIR irradiation, CuxO-CAA NPs possess a high photothermal conversion effect, which can further improve the enzymatic activity for increasing the production rate of H2O2 and ˙OH. Besides, the photodynamic performance of CuxO-CAA NPs can produce 1O2. The generated ROS and hyperthermia have synergetic effects on bacterial mortality. More importantly, CuxO-CAA NPs are more stable and biosafe than Cu2O, and can generate electrostatic adsorption with negatively charged bacterial cell membranes and accelerate bacterial death. Antibacterial results demonstrate that CuxO-CAA NPs are lethal against methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin-resistant Escherichia coli (AREC) through destroying the bacterial membrane and disrupting the bacterial biofilm formation. MRSA-infected animal wound models show that CuxO-CAA NPs can efficiently promote wound healing without causing toxicity to the organism.

Targeted quantitative metabolomic and flavor objective quantification technique reveal the impact mechanism of shaking on black tea quality and non-volatile metabolites.

Shaking constitutes a pivotal technique for enhancing black tea quality; nevertheless, its impact on the transformation mechanism of non-volatile metabolites (NVMs) in black tea remains obscure. The present study aimed to investigate the impact of shaking-withering methods (SWM) and traditional-withering methods (TWM) on black tea quality and NVMs conversion. A total of 57 NVMs and 14 objective quantitative indicators were obtained. SWM enhanced sweetness and umami taste, as well as appearance and liquor color brightness of black tea. Eight key differential NVMs were identified by multivariate statistical and dose over threshold value analysis. Metabolic pathway and evolution law analysis revealed that SWM enhanced the oxidation of catechins and flavonol glycosides, promoted the decarboxylation of glutamic acid, then facilitated the formation of theaflavin-3,3'-digallate, finally enhanced the taste and color quality of black tea. This study offers theoretical guidance and technical support for the targeted processing of high-quality black tea.

Effects of electromagnetic roller-hot-air-steam triple-coupled fixation on reducing the bitterness and astringency and improving the flavor quality of green tea.

Despite the importance of fixation in determining green tea quality, its role in reducing the bitter and astringent taste of this beverage remains largely unknown. Herein, an electromagnetic roller-hot-air-steam triple-coupled fixation (ERHSF) device was developed, and its operating parameters were optimized (steam volume: 20 kg/h; hot-air temperature: 90 °C; hot-air blower speed: 1200 r/min). Compared with conventional fixation treated samples, the ratio of tea polyphenols to free amino acids and ester-catechins to simple-catechins in ERHSF-treated samples was reduced by 11.0% and 3.2%, reducing bitterness and astringency of green tea; amino acids, soluble sugars, and chlorophyll contents were significantly increased, enhancing the freshness, sweetness, and greenness; the color indexes, such as L/L* value of brightness and -a/-a* value of greenness, were also improved, and ERHSF-treated samples had the highest sensory scores. These results provided theoretical support and technical guidance for precise quality improvement of summer-autumn green tea.

Effect of shaking on the improvement of aroma quality and transformation of volatile metabolites in black tea.

Shaking is an innovative technology employed in black tea processing to enhance flavor. However, the effects of shaking on the evolutionary mechanisms of volatile metabolites (VMs) remain unclear. In this study, we compared the effects of a shaking-withering method with those of traditional withering on the flavor and VMs transformation of black tea. The results showed that black tea treated with shaking exhibited excellent quality with floral and fruity aroma. Based on gas chromatography-tandem mass spectrometry, 128 VMs (eight categories) were detected. Combining variable importance projection with odor activity value analysis, eight key differential VMs were identified. Shaking could promote the oxidative degradation of fatty acids and carotenoids and modulate the biosynthesis of terpenoids to facilitate the formation of floral/fruity VMs (such as (Z)-hexanoic acid-3-hexenyl ester, ethyl hexanoate, trans-ß-ionone, and decanal). Our findings provide theoretical guidance for the production of high-quality black tea with floral and fruity aromas.

Assessment of Variations in Round Green Tea Volatile Metabolites During Manufacturing and Effect of Second-Drying Temperature via Nontargeted Metabolomic Analysis.

Round green tea (RGT) is widely distributed and presents a high yield in China. The quality of RGT can be determined by its aroma; however, the transformation and formation of volatile metabolites during RGT processing remain unclear. In this study, 173 volatile compounds (nine categories) were identified totally from RGT via gas chromatography-mass spectrometry with infrared-assisted headspace-solid phase microextraction. These substances exhibited different changing trends during various procedures, with the most intense transformation occurring during fixation, followed by pan-frying and second drying; moreover, 51 substances were screened, mainly containing fatty acid-derived volatiles (i.e., (E)-2-hexen-1-ol, Hexanal, pentanal, hexanal) and glycoside-derived volatiles (i.e., linalool, geraniol, benzyl alcohol, benzaldehyde), and their evolution during processing was clarified. Furthermore, the effect of the second-drying temperature on volatile compound metabolism was clarified, and 90°C was the best temperature for RGT aroma. This research lays a foundation for in-depth quality control and the aroma formation mechanism of RGT.

Analysis of non-volatile and volatile metabolites reveals the influence of second-drying heat transfer methods on green tea quality.

Second-drying is a key process of green tea manufacturing, however, hitherto the effect of second-drying methods on green tea quality has not been assessed. In this study, we compared the effect of three heat transfer drying methods (heat radiation, heat convection, and heat conduction) on green tea quality. Gas chromatography-tandem dual mass spectrometry was used to detect volatile compounds, while absolute quantitative methods were used to detect the non-volatile ones. We identified 45 non-volatile metabolites, 101 volatile metabolites, and 15 objective flavor indicators. Seventeen differential non-volatiles and 8 differential volatiles were screened. Microwave second-drying in heat radiation was the optimal method for green tea flavor, as it can promote the retention of chlorophyll, the degradation of flavonoid glycosides, and the enrichment of amino acids, soluble sugars, nonanal, trans-ß-ionone, linalool, and jasmone. The results provide a theoretical basis and technical guidance for the precise and directional processing of high-quality green tea.

Analysis of volatile metabolite variations in strip green tea during processing and effect of rubbing degree using untargeted and targeted metabolomics.

Strip green tea (SGT) is widely distributed in China owing to its unique appearance and aroma but the evolution and formation mechanisms of volatile metabolites (VMs) during SGT processing, and especially in the unique process of rubbing, remain unclear. In this study, based on untargeted metabolomics, 217 VMs (8 categories) were identified, and fixation and rubbing processes were found to be key for SGT aroma formation. Moreover, targeted metabolomics was applied to obtain 38 differential VMs and their related substances, of which fatty acid-derived volatiles (14 VMs) and glycoside-derived volatiles (8 VMs) showed significant contributions to SGT aroma, and their derivation laws during SGT manufacturing were clarified. Furthermore, the effect of rubbing degree on volatile metabolite formation was explored, and 11 key differential VMs were screened by variable importance in projection, and odor activity value analyses. Appropriate rubbing promoted the loss of grassy VMs (such as 1-octanol and 2-pentyl-furan) and enrichment of floral/fruity VMs (such as trans-ß-ionone, nonanal, geraniol, citral, (Z)-3,7-dimethyl-2,6-octadien-1-ol, and (Z)-hexanoic acid, 3-hexenyl ester). Our study not only enriches the chemical theory of green tea processing but also provides technical support for the precision directional processing of high-quality SGT.

The role of PD-1/PD-L1 and application of immune-checkpoint inhibitors in human cancers.

Programmed cell death protein-1 (PD-1) is a checkpoint receptor expressed on the surface of various immune cells. PD-L1, the natural receptor for PD-1, is mainly expressed in tumor cells. Studies have indicated that PD-1 and PD-L1 are closely associated with the progression of human cancers and are promising biomarkers for cancer therapy. Moreover, the interaction of PD-1 and PD-L1 is one of the important mechanism by which human tumors generate immune escape. This article provides a review on the role of PD-L1/PD-1, mechanisms of immune response and resistance, as well as immune-related adverse events in the treatment of anti-PD-1/PD-L1 immunotherapy in human cancers. Moreover, we summarized a large number of clinical trials to successfully reveal that PD-1/PD-L1 Immune-checkpoint inhibitors have manifested promising therapeutic effects, which have been evaluated from different perspectives, including overall survival, objective effective rate and medium progression-free survival. Finally, we pointed out the current problems faced by PD-1/PD-L1 Immune-checkpoint inhibitors and its future prospects. Although PD-1/PD-L1 immune checkpoint inhibitors have been widely used in the treatment of human cancers, tough challenges still remain. Combination therapy and predictive models based on integrated biomarker determination theory may be the future directions for the application of PD-1/PD-L1 Immune-checkpoint inhibitors in treating human cancers.