Latest ArticlesAfter the concept of liquid biopsy was proposed more than a decade ago, it has quickly expanded to the field of circulating tumor cell (CTC). As a novel biomarker, CTC has the advantages of non-invasiveness, sensitivity, and easy operation, which are incomparable with traditional imaging assay and in vivo detection, therefore it has been an increasingly important technology for tumor diagnosis and treatment. In addition to providing genomic analysis, CTC can provide information at the transcriptomic, proteomic, and epigenomic levels. Compared with other liquid biopsy methods, CTC detection can provide more complete tumor genetic information and show detailed traces of tumor development. Immunotherapy has the best prognosis for colorectal cancer with microsatellite instability (MSI). The detection of CTC has great clinical application value for the prognosis evaluation of colorectal cancer, personalized medicine and the formulation of immunotherapy plans. This review article systematically summarized the various methods of capturing CTC, the prognostic factors that affect the efficacy of colorectal cancer immunotherapy, and how to use CTC characterization to formulate treatment. Schemes, dynamic detection of disease progression, prognosis, evaluation of immunotherapy efficacy and precise treatment are also discussed and prospected.
An HPLC method was established for the assay of epinephrine sulfonate (impurity F) in epinephrine injection. The determination was performed on an AQUASIL C18 (100 mm × 4.6 mm, 3 μm) column with a gradient elution system, and the mobile phase was consisted of monopotassium phosphate solution (mobile phase A) and acetonitrile (mobile phase B). The injection volume was 40 μL. The detection wavelength was at 210 nm and the column temperature was 25 ℃. The total analytical time was 40 min. The results showed that the standard cure of epinephrine sulfonate (impurity F) between peak area and concentration exhibited good linear relationship within the ranges of 0.520-12.480 μg·mL-1 and the R2 = 0.999 8. The average recovery rate was 103.04% and the RSD was 2.00%. The limit concentration of detection was 0.104 μg·mL-1 and the limit concentration of quantitation was 0.520 μg·mL-1. The method could be applied to the determination of epinephrine sulfonate in epinephrine injection with high accuracy and precision, as well as good sensitivity. It could also enhance the quality standards of epinephrine-related products.
Immunotherapy has completely changed the paradigm of clinical tumor treatment, but immune checkpoint inhibitors still have low objective response rates and are prone to drug resistance for most solid tumors. The immune suppression tumor microenvironment and complicated tumor immune escape mechanisms are key factors that affect the clinical outcome and response rates. Therefore, it is critical to reverse the obstacle of the tumor microenvironment to improve immunotherapy efficacy. The immune suppression caused by the increased level of adenosine in the tumor microenvironment raises the attention of people. Targeting adenosine receptors, especially A2AR, will be an effective strategy to improve immunotherapy efficacy. Targeting the adenosine-A2A pathway can increase immune infiltration, enhance immune cell function, and partially reverse immunotherapy-insensitive "cold tumors" to "hot tumors" to enhance treatment response rates and improve the efficacy of current immunotherapy. At present, many adenosine receptor inhibitors have shown good results in clinical trials, especially in combination with immune checkpoint inhibitors, chemotherapy, and adoptive cell transfer therapeutic drugs, which are expected to be used for tumor immunotherapy to bring new breakthroughs. This article reviews the accumulation mode of adenosine in the tumor microenvironment, the role of A2AR and their regulatory mechanism in immune response, the progress of A2AR inhibitors in clinical trials, potential risks to target A2AR, and the prospects for therapeutic targeting A2AR.
SUMOylation is an important post-translational modification of proteins. Similar to ubiquitylation, SUMOylation is the process that the small ubiquitin-like modifier (SUMO) proteins are specifically and covalently binding to lysine residues of substrate proteins. Through SUMOylation, the physiological functions and pathological processes of cells are well controlled and balanced, and its abnormal activation has been reported in various tumors. Therefore, SUMOylation has been a potential target for anti-tumor drug development. In this review, we summarize recent advances on development of inhibitors targeting SUMOylation pathway and their antitumor properties.
In this study, butaselen-2, 6-dimethyl-β-cyclodextrin inclusion complexes were prepared by saturated aqueous solution method to improve the solubility of butaselen, so as to obtain its injection solutions. The content of butaselen in the inclusions was determined by high performance liquid chromatography (HPLC), and then the preparation process was optimized by orthogonal design using the inclusion ratio as an indicator. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) were used to verify the structure of the inclusions. The effects of the inclusions on the solubility and stability of butaselen were also investigated. The results showed that the optimized preparation process with a mass ratio of 1:340, an encapsulation time of 3 h and an encapsulation temperature of 70 ℃ resulted in an encapsulation ratio of (91.24 ± 0.42) %, and the results of XRD, FTIR and SEM demonstrated the formation of inclusion complexes. The developed HPLC method is rapid, simple, accurate, applicable, specific and reproducible for the determination of butaselen content in butaselen cyclodextrin inclusion complexes, which can lay the foundation for the development of new butaselen dosage forms and clinical applications and provide technical support.
A fast and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of prodrug of paclitaxel (Pro-PTX) and paclitaxel (PTX) in rat plasma was developed. The plasma samples were subjected to protein precipitation with acetonitrile (0.1% formic acid), and then separated by LC with an Ultimate AQ-C18 column (50 mm × 3.0 mm, 3 μm) and acetonitrile-1 mmol·L-1 ammonium formate (containing 0.1% formic acid) as the mobile phase. Multiple reaction monitoring (MRM) scanning mode was used to detect the ion responses m/z 983.4→415.2 (Pro-PTX), m/z 854.4→286.1 (PTX) and m/z 808.3→527.2 (Docetaxel, internal standard) by using a triple quadrupole tandem mass spectrometer with electrospray ionization source and positive ion mode. The method validation results show that the linear ranges of Pro-PTX and PTX in plasma were 2.00-500 ng·mL-1 (r > 0.99) and 4.00-1 000 ng·mL-1 (r > 0.99), the lower limit of quantification was 2.00 ng·mL-1 and 4.00 ng·mL-1, respectively; the quality control samples with low, medium and high concentrations of Pro-PTX and PTX were within the batch, the relative standard deviation (RSD) between batches were all less than 9%; the relative deviation (RE) was within the range of ± 9%; In the stability test, both Pro-PTX and PTX in plasma were stable under various storage conditions. The method was sensitive, specific, and reproducible, and was suitable for the pharmacokinetic study of Pro-PTX in rats. Animal experiments were approved by the Ethics Committee of Laboratory Animal Management and Animal Welfare, Institute of Materia Medica, Chinese Academy of Medical Sciences (No.: 00003552).
Ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS/MS) coupled with a molecular network analysis strategy was used to identify the chemical constituents of the stem bark of two kinds of asparagus. The chemical constituents were identified by determining an accurate molecular weight, the fragmentation pathway, and comparison with the mass spectrometry data from the references. A molecular network was established based on the similarity of MS/MS fragmentation patterns. A total of 107 compounds were identified or tentatively deduced, which included 46 saponins, 13 flavonoids, and 48 other compounds. The chemical compounds identified in the stem bark of white and green asparagus differed greatly: the white asparagus was rich in saponins, while the green asparagus was rich in flavonoids. In conclusion, the chemical constituents of asparagus stem bark were characterized rapidly using UPLC-Q-TOF-MS/MS and molecular network analysis, with 10 compounds and 45 targets determined from the HIT 2.0 herbal ingredients' targets platform. This work will provide a theoretical basis for the resource utilization of asparagus.
Tumor cells leads to enhanced glucose uptake and the conversion of a larger fraction of pyruvate into lactate even under the circumstance of abundant oxygen. This phenomenon of aerobic glycolysis is known as the Warburg effect. Lactic acid, as an important tool for tumor cells to modify the tumor microenvironment, promotes the process of tumor invasion and metastasis, and contributes to tumor development by inducing and recruiting immunosuppression-related cells and molecules. Lactic acid could efflux out of the cancer cells via the monocarboxylate transporters to prevent intracellular acidification. Lactate can inhibit the cytolytic activity of T cells and natural killer (NK) cells, promoting the differentiation of tolerogenic interleukin 10 (IL-10)-producing dendritic cells. Moreover, the lactate-derived lactylation of histone lysine residues can promote macrophage polarization toward the M2-like phenotype, suppressing the immune response within the tumor microenvironment. In this review, we discuss the role of lactate as an immunosuppressor molecule that contributes to tumor evasion from the aspects of lactic acid metabolism and its effect on immune cells. And we explore the possibility of targeting potential targets in lactate metabolism for tumor treatment. At last, we proposed a tumor immunotherapy strategy by inhibiting the pathway of aerobic glycolysis and proteins associated with the production and transport of lactic acid.
4-(Cytidine 5′-diphospho)-2-C-methyl-D-erythritol kinase (CMK) was one of the key enzymes in the methylerythritol-4-phosphate (MEP) pathway to generate terpenoids. In this study, based on the transcriptome data of Atractylodes lancea, the sequence of the CMK gene was cloned, named AlCMK (GenBank accession number OM283293). The results showed that AlCMK contains a 1 230 bp open reading frame (ORF) encoding 409 amino acids. The deduced protein had a theoretical molecular weight of 44 752.53 and an isoelectric point of 6.67. Transmembrane structure analysis showed that there was no transmembrane structure, and the secondary structure of AlCMK was predicted to be mainly composed of random coil. Homologous alignment revealed that AlCMK shared high sequence identity with the CMK proteins of Tanacetum cinerariifolium, Osmanthus fragrans, Eucommia ulmoides, Lonicera japonica and Salvia miltiorrhiza. Phylogenetic analysis indicated that AlCMK protein had the higher homology with CMK protein of Compositae. The pET-32a-AlCMK prokaryotic expression vector was constructed and a fusion protein with molecular mass of about 65 kDa was expressed in the E. coli BL21 (DE3). The qRT-PCR was used to analyze the expression pattern of AlCMK gene in different tissues and after MeJA treatment. Meanwhile, the enzyme activity was determined by ELISA kit. The results showed that AlCMK gene was tissue-expressed in different origins and its expression was induced by MeJA, and the results of the enzyme activity assay showed that the AlCMK enzyme activity in different regions was higher in the leaves. The subcellular localization showed that AlCMK was located in the chloroplast. This study provides a reference for further elucidating the biological function of AlCMK gene in terpenoid synthesis pathway in Atractylodes lancea.
To compare the neuroprotective and anti-dementia pharmacological effects of chiral oxiracetam, glutamate and calcium ions were used to establish neuronal injury models in vitro, and the protective effects of chiral oxiracetam on primary neurons were assayed by MTT. Permanent bilateral common carotid artery occlusion (2-VO)-induced rats were randomly divided into sham group, model group, galantamine 3 mg‧kg-1 group, oxiracetam groups (30, 100 and 200 mg‧kg-1), S-oxiracetam groups (30, 100 and 200 mg‧kg-1) and R-oxiracetam 200 mg‧kg-1 group. The animal experiments in the present study were performed in accordance with the Ethical Guidelines of the Laboratory Animal Welfare Ethical Committee of Peking Union Medical College. Morris water maze and step-down test were applied to evaluate the cognitive dysfunction induced by cerebral hypoperfusion in rats. Oxiracetam, S-oxiracetam and R-oxiracetam exerted protective effects on primary neuronal damage caused by various stimuli, and oxiracetam and S-oxiracetam showed better neuro-protective effects. Morris water maze and step-down results showed that oxiracetam, S-oxiracetam and R-oxiracetam improved the cognition of 2-VO rats. In summary, S-oxiracetam exerted a better neuro-protective effect than oxiracetam and R-oxiracetam.