Pulmonary hypertension (PH) is a kind of disease characterized by progressive increase of pulmonary vascular resistance and occlusive vascular remodeling. Hypoxic inductive factor-2α (HIF-2α) plays an important role in the abnormal proliferation of pulmonary vascular cells and pulmonary vascular remodeling. This review focuses on the role of HIF-2α in pulmonary hypertension at the cellular and the global level, and candidates targeting HIF-2α for the treatment of pulmonary hypertension, in order to better understand the pathogenesis of PH and find effective treatments.

Nrf2 is a multi-effect transcription factor, which plays a crucial role in cytoprotective system. With the deepening of research on new regulatory modes and biologic functions of Nrf2, the oncogenic role of Nrf2 in malignant transformed tumors is increasingly obvious. More and more evidences show that Nrf2 is involved in the whole process of tumor occurrence, development, metastasis and prognosis, and inhibiting Nrf2 may be a promising strategy in tumor therapy. However, the development of Nrf2 inhibitors is still in early stage. In this paper, the biological function of Nrf2 and its dual role in tumor are briefly introduced, and representative Nrf2 inhibitors are reviewed according to their structure types, so as to provide reference and ideas for the development of anti-tumor drugs centering on the regulation of Nrf2.

Hair roots induced by Agrobacterium rhizogene produce higher levels of secondary metabolites than non-induced plants, and the enhanced metabolic capacity is driven by the rol gene. We hypothesized that rol genes can be utilized to improve the biosynthesis of tropane alkaloids (TAs) in Atropa belladonna. In this study, the rolC gene from Agrobacterium rhizogene pRiA4 plasmid, driven by a CaMV35S promoter, was overexpressed in A. belladonna. The phenotypes, TAs content and transcriptional expression of key genes in TAs biosynthesis were analyzed in transgenic A. belladonna plants. Results show that transgenic A. belladonna exhibited a well-developed root system, male sterility, higher stamen column length than pistil, early flowering, internode shortening, smaller but more flowers, increased axillary buds and lateral buds, decreased apical dominance, and long and narrow leaves as compared to wild-type plants. Transgenic A. belladonna produced more TAs than wild-type plants, with the content of hyoscyamine, anisodamine and scopolamine reaching 2.58, 3.59 and 15.77-fold that of the control group, respectively. The gene expression of putrescine N-methyltransferase (PMT), tropinone reductase I (TRⅠ) and hyoscyamine 6-β-hydroxylase (H6H), key enzymes in TAs biosynthesis, were up-regulated compared with the control group. The above results indicate that the rolC gene enhances TAs biosynthesis in A. belladonna by up-regulating the expression of key enzymes in the TAs biosynthesis pathway, laying a foundation for genetic manipulation of A. belladonna to increase TAs content by increasing rolC gene expression.

Endoplasmic reticulum (ER), a multifunctional organelle in eukaryotic cells, is responsible for protein synthesis and intracellular signal transduction, which dominates cell function, survival, and apoptosis. Disequilibrium of ER homeostasis may induce ER stress, which closely intertwines with tumor occurrence and progress. A few clinical-used drugs (such as anthraquinones and oxaliplatin) can mediate the immunogenic cell death of tumor cells through excessive ER stress, and sequentially stimulate anti-tumor immune responses as well as long-term immune memory. However, these drugs often exhibit poor targeting ability and extremely low ER accumulation in tumor cells, limiting their clinical efficacy. Therefore, the researches of ER-targeted delivery of these drugs will significantly benefit the efficient and precise anti-tumor immunotherapy. In this review, we introduce the relationship between ER and tumor immunity, and summarize the ER targeting strategies for anti-tumor immunotherapy in recent years. Furthermore, we discuss the problems of existing ER targeting strategies and look into its broad prospects of application.

Tumor microenvironment (TME) is composed of abnormal tumor vasculature, extracellular matrix components, endothelial cells, pericytes, tumor associated fibroblasts, smooth muscle cells and immune cells, which is characterized by hypoxia, acidosis and high interstitial fluid pressure. Hypoxia and acidosis within the TME trigger an adjustment of the extracellular matrix (ECM), a response from neighbor stromal cells (e.g., fibroblasts) and immune cells (lymphocytes and macrophages), inducing tumor growth, angiogenesis, and ultimately, resulting in metastasis. What's more, the components of TME including abnormal tumor vasculature, rich composition of the ECM, and abundant stroma cells impair tumoral distribution and penetration of the drugs. At the same time, this stromal microenvironment plays a vital role in creating an immunosuppressive environment.Over the past years, more and more researches focus on targeting and remolding TME to improve therapeutic effects against tumors. Herein, we reviewed current strategies developed to target and remodel TME, including modulating tumor hypoxia, tumor vasculature, tumor associated fibroblasts, extracellular matrix components, tumor associated macrophage phenotypes and dendritic cells. Also, potential problems and future directions are pointed out in this review.

Cancer is considered as one of the major diseases endangering human health in the world, it is urgent to find a safer and more efficient treatment for cancer therapy. Gene therapy with ribonucleic acid (RNA) drugs could regulate the expression of tumor related genes, and exhibit good anti-tumor therapeutic potential in preclinical and clinical trials. Based on the differences between tumor tissues and normal tissues in microenvironment signal characteristics such as pH, specific enzyme concentration or redox gradient, various microenvironment responsive nanocarriers had been studied and developed to deliver RNA drugs to tumor tissues and cells, improving the anti-tumor efficacy of RNA drugs and reducing toxic and side effects. This paper reviews the pathophysiological characteristics of tumor microenvironment and various strategies of tumor microenvironment responsive nanocarriers, in order to provide reference for the design of safe and efficient RNA drug delivery system for cancer therapy.

The neonatal Fc receptor (FcRn) was first found to be a membrane protein that maternal antibodies transmitted to fetuses and newborns, and also expressed in multiple organs and tissues for whole life in adults. It plays a significant role to central regulate the lifespan of immunoglobulin G and serum albumin, as well as its involvement in innate and adaptive immune responses. In modern biopharmaceuticals, FcRn is a great potential drug delivery target and a highlighted subject for current research. This paper briefly describes the basic biological properties and action mechanism of FcRn, as well as the commonly used drug carrier design strategies of FcRn, especially the functional applications of prolonging half-life, targeted drug delivery, transmembrane and antigen presentation and so on. We propose that these distribution in different tissues and the diverse biological activities may have significant implications of targeting FcRn for novel drug delivery systems and immunotherapy.

This paper aims to develop folic acid-modified paclitaxel nanocrystals (PTX NC@FA) with good stability, high drug loading and tumor cell targeting for endoscopic injection for preoperative local chemotherapy of gastric cancer. PTX NC@FA was prepared by the "bottom-up" followed by ultrasonic to study its morphology, particle size, ζ-potential, drug loading, folic acid-modified phospholipid (FA-DSPE-PEG₂₀₀₀) content, crystalline characteristics, stability, in vitro release, cytotoxicity against human gastric cancer cell line SGC-7901, and anti-tumor effect in two different tumor sizes (tumor volume 100 mm³ or 300 mm³) after single peri-tumor injection in a murine subcutaneous SGC-7901 tumor model. Animal experiments were approved by the Experimental Animal Ethics Committee of the School of Pharmacy, Fudan University. The resulting PTX NC@FA was of short rod-like shape, average particle size 175.3±2.5 nm (PDI 0.17±0.02), ζ-potential -2.5±0.2 mV, PTX loading (28.23±0.74)% (w/w) and FA-DSPE-PEG₂₀₀₀ content (4.40±0.60)% (w/w). The size of the PTX NC@FA remained unchanged for 4 days in phosphate buffer with or without serum. Cellular growth inhibition effect on SGC-7901 showed the superiority of PTX NC@FA over nanocrystals without FA modification. PTX NC@FA inhibited tumor growth more efficiently than both nanocrystals without FA modification and commercially available paclitaxel injection (Taxol) 12 days after peri-tumor injection. For model tumor with the volume of 100 mm³, tumors of all animals in the PTX NC@FA group disappeared completely. For model tumor with the volume of 300 mm³, tumors of 3 animals in the PTX NC@FA group completely disappeared and tumors of the rest 4 animals also became significantly smaller with a tumor volume inhibition rate of 90%. PTX NC@FA showed good potential for preoperative chemotherapy of increase the chances of function preserving gastrectomy and improve the quality of life of patients.

Tumor immune checkpoint therapy is a clinical treatment strategy developed based on the new principle of the inhibition of negative immune regulation. In this article, the tumor immune checkpoint therapy and the drug delivery strategies were reviewed, mainly including immunity and tumor therapy, tumor immune checkpoint therapy and its mechanism of action, clinical application of tumor immune checkpoint therapy and therapeutic drugs, immune resistance of programmed cell death protein 1 (PD1)/programmed cell death ligand 1 (PDL1) treatment and countermeasures, drug delivery strategies for tumor immune checkpoint therapeutic agents, etc. As a revolutionary new immunotherapy strategy, tumor immune checkpoint therapy has shown obvious superior therapeutic efficacy in a variety types of tumor. However, tumor immune checkpoint therapy is also faced with a big challenge, namely, immunotherapy resistance. With the discovery of new mechanism, the continuous development of new therapeutic drugs and delivery strategies, tumor immune checkpoint therapy is expected to further improve the clinical efficacy of tumor.

Exosomes are one of the most important ways of cell-to-cell communication in living lives. They are involved in major physiological and pathological processes, including drug resistance, infection propagation, cancer development and cardiovascular diseases. The biological functions of exosomes made it possess characteristics of low immunogenicity, high delivery efficiency, ability to cross multiple biological barriers and targeting capacity, which also encourage people to try to use it as a drug carrier to overcome the disadvantages of poor stability, low solubility, low bioavailability and high toxicity of some drugs. In this paper, the latest progress of exosomes in the delivery of antitumor drugs, including small chemotherapeutic drugs, biological macromolecules and nucleic acid drugs, is reviewed. In addition, the isolation, drug loading, and modification method and the application prospect of exosomes are also discussed.