Immune system-mediated tumor killing has revolutionized anti-tumor therapies, providing long-term and durable responses in some patients. The phosphoinositide 3-kinase (PI3K) pathway controls ...multiple biological processes and is frequently dysregulated in malignancies. Enormous efforts have been made to develop inhibitors against class I PI3K. Notably, with the increasing understanding of PI3K, it has been widely accepted that PI3K inhibition not only restrains tumor progression, but also reshapes the immunosuppressive tumor microenvironment. In this review, we focus on the pivotal roles of class I PI3Ks in adaptive and innate immune cells, as well as other stromal components. We discuss the modulation by PI3K inhibitors of the tumor-supportive microenvironment, including eliminating the regulatory immune cells, restoring cytotoxic cells or regulating angiogenesis. The potential combinations of PI3K inhibitors with other therapies to enhance the anti-tumor immunity are also described.
Oncogene-induced cellular senescence (OIS) is a complex program that is triggered in response to aberrant activation of oncogenic signaling. Initially, OIS was thought to be a barrier to malignant ...transformation because of its suppression on cell proliferation. Later studies showed that senescence induced by oncogenes can also promote the initiation and development of cancer. The opposing effects of OIS occur through different combinations of downstream effectors as well as the interplay of senescent cells and the microenvironment, such as senescence-associated inflammation. Here, we review the common features and molecular mechanisms underlying OIS and the interaction between senescent cells and the microenvironment. We propose that targeting senescent cells may have a beneficial therapeutic effect during the treatment of cancer.
The pivotal roles of phosphatidylinositol 3-kinases （PI3Ks） in human cancers have inspired active development of small molecules to inhibit these lipid kinases. However, the first-generation pan-PI3K ...and dual-PI3K/mTOR inhibitors have encountered problems in clinical trials, with limited efficacies as a monotherapeutic agent as well as a relatively high rate of side effects. It is increasingly recognized that different PI3K isoforms play non-redundant roles in particular tumor types, which has prompted the development of isoform-selective inhibitors for pre-selected patients with the aim for improving efficacy while decreasing undesirable side effects. The success of PI3K isoform-selective inhibitors is represented by CAL101 （Idelalisib）, a first-in-class PI3Kδ-selective small-molecule inhibitor that has been approved by the FDA for the treatment of chronic lymphocytic leukemia, indolent B-cell non-Hodgkin’s lymphoma and relapsed small lymphocytic lymphoma. Inhibitors targeting other PI3K isoforms are also being extensively developed. This review focuses on the recent progress in development of PI3K isoform-selective inhibitors for cancer therapy. A deeper understanding of the action modes of novel PI3K isoform-selective inhibitors will provide valuable information to further validate the concept of targeting specific PI3K isoforms, while the identification of biomarkers to stratify patients who are likely to benefit from the therapy will be essential for the success of these agents.
Cancer is a highly heterogeneous disease in term of molecular signature even though it is originated from the same tissue type. Cancer heterogeneity may occur during its development or treatment, ...which is the main cause resulting in drug resistance and recurrence. Precision medicine refers to matching the right medicine to the right patients based on their molecular signatures. Therefore, a thorough understanding of the mechanism of tumorigenesis and drug resistance is essential to precision medicine. CRISPR-cas9 system is a powerful tool for gene editing and CRISPR-based high-throughput screening has been widely applied especially in searching for tumor-driven or synergistic lethal genes aiming to overcome drug resistance. In this review, we describe the progress of CRISPR-cas9-based unbiased screening in precision medicine including identification of new drug targets, biomarkers and elucidation of mechanisms leading to drug resistance. The existing challenges as well as the future directions are also discussed.
Rapamycin and its analogs (rapalogs) are the first generation of mTOR inhibitors, which have the same molecular scaffold, but different physiochemical properties. Rapalogs are being tested in a wide ...spectrum of human tumors as both monotherapy and a component of combination therapy. Among them, temsirolimus and everolimus have been approved for the treatment of breast and renal cancer. However, objective response rates with rapalogs in clinical trials are modest and variable. Identification of biomarkers predicting response to rapalogs, and discovery of drug combinations with improved efficacy and tolerated toxicity are critical to moving this class of targeted therapeutics forward. This review focuses on the aberrations in the PI3K/mTOR pathway in human tumor cells or tissues as predictive biomarkers for rapalog efficacy. Recent results of combinational therapy using rapalogs and other anticancer drugs are documented. With the rapid development of next-generation genomic sequencing and precision medicine, rapalogs will provide greater benefits to cancer patients.
Abstract
Nationwide prospective surveillance of all-age patients with acute respiratory infections was conducted in China between 2009‒2019. Here we report the etiological and epidemiological ...features of the 231,107 eligible patients enrolled in this analysis. Children <5 years old and school-age children have the highest viral positivity rate (46.9%) and bacterial positivity rate (30.9%). Influenza virus, respiratory syncytial virus and human rhinovirus are the three leading viral pathogens with proportions of 28.5%, 16.8% and 16.7%, and
Streptococcus pneumoniae
,
Mycoplasma pneumoniae
and
Klebsiella pneumoniae
are the three leading bacterial pathogens (29.9%, 18.6% and 15.8%). Negative interactions between viruses and positive interactions between viral and bacterial pathogens are common. A Join-Point analysis reveals the age-specific positivity rate and how this varied for individual pathogens. These data indicate that differential priorities for diagnosis, prevention and control should be highlighted in terms of acute respiratory tract infection patients’ demography, geographic locations and season of illness in China.
National-based prospective surveillance of all-age patients with acute diarrhea was conducted in China between 2009‒2018. Here we report the etiological, epidemiological, and clinical features of the ...152,792 eligible patients enrolled in this analysis. Rotavirus A and norovirus are the two leading viral pathogens detected in the patients, followed by adenovirus and astrovirus. Diarrheagenic Escherichia coli and nontyphoidal Salmonella are the two leading bacterial pathogens, followed by Shigella and Vibrio parahaemolyticus. Patients aged <5 years had higher overall positive rate of viral pathogens, while bacterial pathogens were more common in patients aged 18‒45 years. A joinpoint analysis revealed the age-specific positivity rate and how this varied for individual pathogens. Our findings fill crucial gaps of how the distributions of enteropathogens change across China in patients with diarrhea. This allows enhanced identification of the predominant diarrheal pathogen candidates for diagnosis in clinical practice and more targeted application of prevention and control measures.
CXCL12/CXCR4 plays an important role in metastasis of gastric carcinoma. Rapamycin has been reported to inhibit migration of gastric cancer cells. However, the role of mTOR pathway in ...CXCL12/CXCR4-mediated cell migration and the potential of drugs targeting PI3K/mTOR pathway remains unelucidated. We found that CXCL12 activated PI3K/Akt/mTOR pathway in MKN-45 cells. Stimulating CHO-K1 cells expressing pEGFP-C1-Grp1-PH fusion protein with CXCL12 resulted in generation of phosphatidylinositol (3,4,5)-triphosphate, which provided direct evidence of activating PI3K by CXCL12. Down-regulation of p110β by siRNA but not p110α blocked phosphorylation of Akt and S6K1 induced by CXCL12. Consistently, p110β-specific inhibitor blocked the CXCL12-activated PI3K/Akt/mTOR pathway. Moreover, CXCR4 immunoprecipitated by anti-p110β antibody increased after CXCL12 stimulation and Gi protein inhibitor pertussis toxin abrogated CXCL12-induced activation of PI3K. Further studies demonstrated that inhibitors targeting the PI3K/mTOR pathway significantly blocked the chemotactic responses of MKN-45 cells triggered by CXCL12, which might be attributed primarily to inhibition of mTORC1 and related to prevention of F-actin reorganization as well as down-regulation of active RhoA, Rac1, and Cdc42. Furthermore, rapamycin inhibited the secretion of CXCL12 and the expression of CXCR4, which might form a positive feedback loop to further abolish upstream signaling leading to cell migration. Finally, we found cells expressing high levels of cxcl12 were sensitive to rapamycin in its activity inhibiting migration as well as proliferation. In summary, we found that the mTOR pathway played an important role in CXCL12/CXCR4-mediated cell migration and proposed that drugs targeting the mTOR pathway may be used for the therapy of metastatic gastric cancer expressing high levels of cxcl12.
Background: The cross-talk between CXCL12/CXCR4 axis and PI3K/mTOR pathway in migration of gastric carcinoma cells is unknown.
Results: p110β provided a conduit for CXCL12-stimulated signaling and targeting PI3K/mTOR blocked CXCL12-activated cell motility.
Conclusion: Targeting PI3K/mTOR pathway inhibited CXCL12-mediated cell migration.
Significance: Drugs targeting mTOR pathway may be used for the therapy of metastatic gastric cancer expressing high levels of CXCL12.
We report for the first time the usage of Millettia speciosa Champ cellulose (MSCC) and carboxymethylcellulose (MSCCMC) for the fabrication of 3D-network hydrogel as delivery system for probiotics. ...The structural features, swelling behavior and pH-responsiveness of MSCC-MSCCMC hydrogels and their encapsulation and controlled-release behavior for Lactobacillus paracasei BY2 (L. paracasei BY2) were mainly studied. Structural analyses demonstrated that MSCC-MSCCMC hydrogels with porous and network structures were successfully synthesized through the crosslinking of –OH groups between MSCC and MSCCMC molecules. An increasing concentration of MSCCMC significantly improved the pH-responsiveness and swelling ability of the MSCC-MSCCMC hydrogel toward neutral solvent. Besides, the encapsulation efficiency (50.38–88.91 %) and release (42.88–92.86 %) of L. paracasei BY2 were positively correlated with the concentration of MSCCMC. The higher the encapsulation efficiency was, the higher the release in the target intestine. However, due to the existence of bile salts, controlled-release behavior decreased the survivor rate and physiological state (degrading cholesterol) of encapsulating L. paracasei BY2. Even so, the number of viable cells encapsulated by hydrogels still reached the minimum effective concentration in the target intestine. This study provides an available reference for the practical application of hydrogels fabricated from the cellulose of the Millettia speciosa Champ plant for probiotic delivery.
Indoleamine 2,3-dioxygenase 1 (IDO1) is the enzyme catalyzing the oxidative metabolism of tryptophan, which accounts for cancer immunosuppression in tumor microenvironment. Several compounds ...targeting IDO1 have been reported and epacadostat shows strong inhibitory activity against IDO1, which is further studied in clinic trails. However, its pharmacokinetic profiles are not satisfactory. The half-life of epacadostat is 2.4 h in human and dosage is 50 mg BID in the phase III clinic trial. To overcome the shortcomings of epacadostat, structure-based drug design was performed to improve the pharmacokinetic profiles via changing the metabolic pathway of epacadostat and to enhance anti-tumor potency. A novel series of 1,2,5-oxadiazole-3-carboximidamide derivatives bearing cycle in the side chain were designed, synthesized, and biologically evaluated for their anti-tumor activity. Most of them exhibited potent activity against hIDO1 in enzymatic assays and in HEK293T cells over-expressing hIDO1. Among them, compound 23, 25 and 26 showed significant inhibitory activity against hIDO1 (IC50 = 108.7, 178.1 and 139.1 nM respectively) and in HEK293T cells expressing hIDO1 (cellular IC50 = 19.88, 68.59 and 57.76 nM respectively). Moreover, compound 25 displayed improved PK property with longer half-life (t1/2 = 3.81 h in CD-1 mice) and better oral bioavailability (F = 33.6%) compared with epacadostat. In addition, compound 25 showed similar potency to inhibit the growth of CT-26 syngeneic xenograft compared to epacadostat, making it justifiable for further investigation.
Display omitted
•Novel 1,2,5-oxadiazole-3-carboximidamide derivatives as IDO1 inhibitors were designed, synthesized, and evaluated.•The structure-activity relationship (SAR) of this novel series of 27 compounds was demonstrated.•Compound 23, 25 and 26 demonstrated potent in vitro inhibitory activity against hIDO1 (IC50 = 108.7, 178.1 and 139.1 nM respectively) and compound 25 showed improved PK profiles (t1/2 = 3.81 h, F = 33.6%) compared with epacadostat.•Compound 25 exhibited the similar anti-tumor efficacy with epacadostat without inducing significant change in body weight compared to the control group.
PDF
