Association Between Unstable Angina and CXCL17: a New Potential Biomarker

From orphan to oncogene: The role of GPR35 in cancer and immune modulation

G protein-coupled receptors (GPCRs) are well-studied and the most traceable cell surface receptors for drug discovery. One of the intriguing members of this family is G protein-coupled receptors 35 (GPR35), which belongs to the class A rhodopsin-like family of GPCRs identified over two decades ago. GPR35 presents interesting features such as ubiquitous expression and distinct isoforms. Moreover, functional and genome-wide association studies on its widespread expression have linked GPR35 with pathophysiological disease progression. Various pieces of evidence have been accumulated regarding the independent or endogenous ligand-dependent role of GPR35 in cancer progression and metastasis. In the current scenario, the relationship of this versatile receptor and its putative endogenous ligands for the activation of oncogenic signal transduction pathways at the cellular level is an active area of research. These intriguing features offered by GPR35 make it an oncological target, justifying its uniqueness at the physiological and pathophysiological levels concerning other GPCRs. For pharmacologically targeting receptor-induced signaling, few potential competitive antagonists have been discovered that offer high selectivity at a human level. In addition to its fascinating features, targeting GPR35 at rodent and human orthologue levels is distinct, thus contributing to the sub-species selectivity. Strategies to modulate these issues will help us understand and truly target GPR35 at the therapeutic level. In this article, we have provided prospects on each topic mentioned above and suggestions to overcome the challenges. This review discusses the molecular mechanism and signal transduction pathways activated by endogenous ligands or spontaneous auto-activation of GPR35 that contributes towards disease progression. Furthermore, we have highlighted the GPR35 structure, ubiquitous expression, its role in immunomodulation, and at the pathophysiological level, especially in cancer, indicating its status as a versatile receptor. Subsequently, we discussed the various proposed ligands and their mechanism of interaction with GPR35. Additionally, we have summarized the GPR35 antagonist that provides insights into the opportunities for therapeutically targeting this receptor.

The cryptic role of CXCL17/CXCR8 axis in the pathogenesis of cancers: a review of the latest evidence

Chemokines are immune system mediators that mediate various activities and play a role in the pathogenesis of several cancers. Among these chemokines, C-X-C motif chemokine 17 (CXCL-17) is a relatively novel molecule produced along the airway epithelium in physiological and pathological conditions, and evidence shows that it plays a homeostatic role in most cases. CXCL17 has a protective role in some cancers and a pathological role in others, such as liver and lung cancer. This chemokine, along with its possible receptor termed G protein-coupled receptor 35 (GPR35) or CXCR8, are involved in recruiting myeloid cells, regulating angiogenesis, defending against pathogenic microorganisms, and numerous other mechanisms. Considering the few studies that have been performed on the dual role of CXCL17 in human malignancies, this review has investigated the possible pro-tumor and anti-tumor roles of this chemokine, as well as future treatment options in cancer therapy.

Effect of combining sST2/HDL-C ratio with risk factors of coronary heart disease on the detection of angina pectoris in Chinese: a retrospective observational study

Background

Soluble suppression of tumorigenicity 2 (sST2), a member of the interleukin-1 receptor family, binds IL-33, preventing its interaction with membrane-bound form ST2 (ST2L), thereby blocking its protection against atherosclerosis. High-density lipoprotein cholesterol (HDL-C), a variety of lipoproteins with mean size of 8-10 nm and density of 1.063-1.21 g/mL, not only acts as lipid transporters that transport cholesterol reversely, but also carries a variety of proteins and microRNAs endowing it with the ability to prevent cardiovascular disease. Most studies on the relationship between sST2 and coronary heart disease (CHD) are limited to acute myocardial infarction (AMI). The present study set out to investigate the association between the sST2/HDL-C ratio and angina pectoris.

Methods

A retrospective single-center cohort study was conducted and a total of 250 patients with chest pain that formed a convenience series, hospitalized between January 2018 and August 2020, were enrolled. Patients with AMI, acute and chronic heart failure, structural heart disease, renal insufficiency [estimate glomerular filtration rate (eGFR) <60 mL/min/1.73 m2], rheumatic immune diseases, malignant tumors and severe infections were excluded. Patients with missing data were also excluded. Two hundred and nine patients were finally enrolled. Levels of sST2, HDL-C and sST2/HDL-C ratio were measured and calculated after admission. The angina pectoris was diagnosed by combining clinical features, coronary angiography results and cardiac troponin I levels. The diagnosis value of sST2/HDL-C on angina pectoris was analyzed by binary logistic analysis and the receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) assesses.

Results

Patients with stable angina pectoris (SAP) or unstable angina pectoris (UAP) accounted for a larger proportion (28.8% vs. 42.9%, P=0.035) in patients with the higher sST2/HDL-C ratio. Binary logistics regression showed that for every unit of sST2/HDL-C increase, the risk of angina pectoris increased by 38.8% (OR =1.388, P=0.018). By subgroup analysis, a stronger association was found in non-diabetic patients (OR =1.551, P=0.006), non-hypertension patients (OR =1.700, P=0.025), non-smokers (OR =1.527, P=0.049) and patients aged <65 y (OR =1.693, P=0.019). ROC curve showed that AUC was higher [0.643 (0.566, 0.719) vs. 0.618 (0.540, 0.696)] and the sensitivity of diagnosis increased significantly (84.0% vs. 49.3%) by combining sST2/HDL-C with risk factors of CHD.

Conclusions

A higher ratio of sST2/HDL-C was associated with an increased risk of angina pectoris. sST2/HDL-C combined with CHD risk factors showed increased diagnostic value in identifying angina pectoris.

Trial Registration

Clinical trial: ChiCTR-DDD-17013908.

A comprehensive review of chemokine CXC17 (VCC1) in cancer, infection, and inflammation

A crucial component of the immune system are chemokiness. Chemokine's dysregulation has been linked to a number of pathological diseases. Recently, CXCL17, a chemokine belonging to the CXC subfamily, was identified. With regard to a number of physiological conditions and disorders, CXCL17 either has homeostatic or pathogenic effects. Some research suggests that CXCL17 is an orphan ligand, despite the fact that G protein-coupled receptor (GPR) 35 has been suggested as a possible receptor for CXCL17. Since CXCL17 is primarily secreted by mucosal epithelia, such as those in the digestive and respiratory tracts, under physiological circumstances, this chemokine is referred to as a mucosal chemokine. Macrophages and monocytes are the cells that express GPR35 and hence react to CXCL17. In homeostatic conditions, this chemokine has anti-inflammatory, antibacterial, and chemotactic properties. CXCL17 promotes angiogenesis, metastasis, and cell proliferation in pathologic circumstances like malignancies. However, other studies suggest that CXCL17 may have anti-tumor properties. Additionally, studies have shown that CXCL17 may have a role in conditions such as idiopathic pulmonary fibrosis, multiple sclerosis, asthma, and systemic sclerosis. Additionally, deregulation of CXCL17 in some diseases may serve as a biomarker for diagnosis and prognosis. Clarifying the underlying mechanism of CXCL17's activity in homeostatic and pathological situations may thus increase our understanding of its role and hold promise for the development of novel treatment strategies.