hCG stimulates angiogenic signals in lymphatic endothelial and circulating angiogenic cells

Expression characteristics and biological functions of CGB5 gene in gastric cancer

OBJECTIVE

The chorionic gonadotropin (CG) subunit beta 5 (CGB5) gene is a member of the glycoprotein hormone β chain family, encoding the β5 subunit of CG, which has been shown to promote tumorigenesis and induce proliferation in various types of cancer including gastric cancer (GC). However, the mechanistic role of CGB5 in GC has not been fully elucidated. Therefore, this study investigated relevant genes that regulate GC through bioinformatics analysis.

METHODS

Immunohistochemistry, immunofluorescence, and western blot (WB) detection methods were appropriately used to evaluate the expression pattern and clinical significance of CGB5 in 100 Chinese GC patients that were recruited from the Gaochun People's Hospital. The effect of small interfering ribonucleic acid (siRNA) on apoptosis, migration, and invasion of GC cells was investigated in vitro. Three-dimensional tumor spheres of these two types of GC cells (NCI-N87 cells and MKN45 cells) were constructed before investigation of the Calcein acetoxymethyl ester (AM)/ Propidium iodide (PI) staining, flow cytometric apoptosis, and apoptotic-related protein content of the tumor spheres after siRNA inhibition of CGB5 expression.

RESULTS

It was observed that compared with adjacent normal gastric tissue, expression of CGB5 was significantly upregulated in GC tissue. The siRNA inhibited CGB5 expression in two GC cell lines (NCI-N87 cells and MKN45 cells). Also, it was discovered that CGB5 highly correlated with microsatellite instability (MSI) and immune cell activity in GC, thus revealing the greater research value of CGB5 gene. More importantly, CGB5 siRNA could inhibit invasion and migration of tumor cells, induce apoptosis of GC cells and GC tumor spheres, as well as the mechanism relating to regulation of apoptosis associated gene expression. Overall, the findings suggest that CGB5 may play a crucial role in the development of GC carcinogenesis. Thus, this research may contribute to design of potential drug targets for treatment of GC.

Luteinizing hormone receptor promotes angiogenesis in ovarian endothelial cells of Macaca fascicularis and Homo sapiens†

Angiogenesis within the ovarian follicle is an important component of ovulation. New capillary growth is initiated by the ovulatory surge of luteinizing hormone (LH), and angiogenesis is well underway at the time of follicle rupture. LH-stimulated follicular production of vascular growth factors has been shown to promote new capillary formation in the ovulatory follicle. The possibility that LH acts directly on ovarian endothelial cells to promote ovulatory angiogenesis has not been addressed. For these studies, ovaries containing ovulatory follicles were obtained from cynomolgus macaques and used for histological examination of ovarian vascular endothelial cells, and monkey ovarian microvascular endothelial cells (mOMECs) were enriched from ovulatory follicles for in vitro studies. mOMECs expressed LHCGR mRNA and protein, and immunostaining confirmed LHCGR protein in endothelial cells of ovulatory follicles in vivo. Human chorionic gonadotropin (hCG), a ligand for LHCGR, increased mOMEC proliferation, migration and capillary-like sprout formation in vitro. Treatment of mOMECs with hCG increased cAMP, a common intracellular signal generated by LHCGR activation. The cAMP analog dibutyryl cAMP increased mOMEC proliferation in the absence of hCG. Both the protein kinase A (PKA) inhibitor H89 and the phospholipase C (PLC) inhibitor U73122 blocked hCG-stimulated mOMEC proliferation, suggesting that multiple G-proteins may mediate LHCGR action. Human ovarian microvascular endothelial cells (hOMECs) enriched from ovarian aspirates obtained from healthy oocyte donors also expressed LHCGR. hOMECs also migrated and proliferated in response to hCG. Overall, these findings indicate that the LH surge may directly activate ovarian endothelial cells to stimulate angiogenesis of the ovulatory follicle.

A novel necroptosis-related gene index for predicting prognosis and a cold tumor immune microenvironment in stomach adenocarcinoma

Background

Gastric cancer (GC) represents a major global clinical problem with very limited therapeutic options and poor prognosis. Necroptosis, a recently discovered inflammatory form of cell death, has been implicated in carcinogenesis and inducing necroptosis has also been considered as a therapeutic strategy.

Objective

We aim to evaluate the role of this pathway in gastric cancer development, prognosis and immune aspects of its tumor microenvironment.

Methods and results

In this study, we evaluated the gene expression of 55 necroptosis-related genes (NRGs) that were identified via carrying out a comprehensive review of the medical literature. Necroptosis pathway was deregulated in gastric cancer samples (n=375) as compared to adjacent normal tissues (n=32) obtained from the “The Cancer Genome Atlas (TCGA)”. Based on the expression of these NRGs, two molecular subtypes were obtained through consensus clustering that also showed significant prognostic difference. Differentially expressed genes between these two clusters were retrieved and subjected to prognostic evaluation via univariate cox regression analysis and LASSO cox regression analysis. A 13-gene risk signature, termed as necroptosis-related genes prognostic index (NRGPI), was constructed that comprehensively differentiated the gastric cancer patients into high- and low-risk subgroups. The prognostic significance of NRGPI was validated in the GEO cohort (GSE84437: n=408). The NRGPI-high subgroup was characterized by upregulation of 10 genes (CYTL1, PLCL1, CGB5, CNTN1, GRP, APOD, CST6, GPX3, FCN1, SERPINE1) and downregulation of 3 genes (EFNA3, E2F2, SOX14). Further dissection of these two risk groups by differential gene expression analysis indicated involvement of signaling pathways associated with cancer cell progression and immune suppression such as WNT and TGF-β signaling pathway. Para-inflammation and type-II interferon pathways were activated in NRGPI-high patients with an increased infiltration of Tregs and M2 macrophage indicating an exhausted immune phenotype of the tumor microenvironment. These molecular characteristics were mainly driven by the eight NRGPI oncogenes (CYTL1, PLCL1, CNTN1, GRP, APOD, GPX3, FCN1, SERPINE1) as validated in the gastric cancer cell lines and clinical samples. NRGPI-high patients showed sensitivity to a number of targeted agents, in particular, the tyrosine kinase inhibitors.

Conclusions

Necroptosis appears to play a critical role in the development of gastric cancer, prognosis and shaping of its tumor immune microenvironment. NRGPI can be used as a promising prognostic biomarker to identify gastric cancer patients with a cold tumor immune microenvironment and poor prognosis who may response to selected molecular targeted therapy.

Discovery of Prognostic Signature Genes for Overall Survival Prediction in Gastric Cancer

Background

Gastric cancer (GC) is one of the most common malignant tumors in the digestive system with high mortality globally. However, the biomarkers that accurately predict the prognosis are still lacking. Therefore, it is important to screen for novel prognostic markers and therapeutic targets.

Methods

We conducted differential expression analysis and survival analysis to screen out the prognostic genes. A stepwise method was employed to select a subset of genes in the multivariable Cox model. Overrepresentation enrichment analysis (ORA) was used to search for the pathways associated with poor prognosis.

Results

In this study, we designed a seven-gene-signature-based Cox model to stratify the GC samples into high-risk and low-risk groups. The survival analysis revealed that the high-risk and low-risk groups exhibited significantly different prognostic outcomes in both the training and validation datasets. Specifically, CGB5, IGFBP1, OLFML2B, RAI14, SERPINE1, IQSEC2, and MPND were selected by the multivariable Cox model. Functionally, PI3K-Akt signaling pathway and platelet-derived growth factor receptor (PDGFR) were found to be hyperactive in the high-risk group. The multivariable Cox regression analysis revealed that the risk stratification based on the seven-gene-signature-based Cox model was independent of other prognostic factors such as TNM stages, age, and gender.

Conclusion

In conclusion, we aimed at developing a model to predict the prognosis of gastric cancer. The predictive model could not only effectively predict the risk of GC but also be beneficial to the development of therapeutic strategies.

CXCL12 in normal and pathological pregnancies: A review

The survival of allogeneic fetuses during pregnancy is a rather paradoxical phenomenon with a complex mechanism. Chemokine ligand12 (CXCL12) and its receptors CXC chemokine receptor (CXCR)4 and 7 are extensively found in placenta tissues and cells, including trophoblast cells, vascular endothelial cells, and decidual stromal and decidual immune cells (eg, NK cells and regulatory T cells). Evidence has illustrated that the CXClL12/CXCR4/CXCR7 axis could enhance the cross talk at the maternal-fetal interface through multiple processes, such as invasion and placental angiogenesis, which appears to be critical signaling components in placentation and fetal outcome. In addition, an increasing number of studies have demonstrated that the CXCL12/CXCR4/CXCR7 axis also stands out for its pleiotropic roles in several pregnancy-associated diseases (eg, recurrent spontaneous abortion (RSA), pre-eclampsia (PE), and preterm labor). In the present review, the different biological properties and signaling in physiological and pathological pregnancy conditions of CXCL12/CXCR4/CXCR7 axis were discussed, with the aim of obtaining a further understanding of the regulatory mechanisms and highlighting their potential as a target for therapeutic approaches.

CGB5 expression is independently associated with poor overall survival and recurrence-free survival in patients with advanced gastric cancer

The human CGB5 gene encodes chorionic gonadotropin (hCG)β 5, which is aberrantly expressed in trophoblastic neoplasm and in some non‐trophoblastic neoplasms. Fucntional studies observed that it involved tumor initiation, growth, and metastatic outgrowth. In this study, using data from the International Cancer Genome Consortium (ICGC) and the Cancer Genome Atlas (TCGA)‐stomach adenocarcinoma (STAD), we assessed the independent prognostic value of CGB5 expression in patients with primary gastric cancer (GC). Results showed that CGB5 expression was nearly not expressed in normal GC tissues. In comparison, its expression was detected in 214 of the 415 primary GC cases (51.6%) in TCGA‐STAD and was associated with poor response to primary therapy and a higher risk of recurrence and death. In early stages, CGB5 expression was not a prognostic factor in terms of OS (HR: 1.448; 95% CI: 0.811–2.588, P = 0.211) or RFS (HR: 1.659; 95% CI: 0.778–3.540, P = 0.190). However, its expression was independently associated with unfavorable OS (HR: 1.719; 95% CI: 1.115–2.651, P = 0.014) and RFS (HR: 3.602; 95% CI: 1.708–7.598, P = 0.001) in advanced stages. Using deep sequencing data from TCGA‐STAD, we found that CGB5 expression was not related to its genetic amplification or DNA methylation in GC. Based on these findings, we infer that CGB5 expression is common in GC patients and its expression might independently predict poor OS and RFS in advanced stages, but not in early stages of GC.

ELM: A New, Simple, and Economic Assay to Measure Motility of Lymphatic Endothelial Cells

BACKGROUND

Relatively few attempts have been made to set up an assay that allows the measurement of lymphatic endothelial cells (LECs) motility. Nowadays, the most widely used methods involve adaptation of the Boyden chamber method or the wound scratch assay, both of them showing some limitations due to long and expensive setup and high variability.

METHODS AND RESULTS

We propose a new, economic, and easy to setup LEC Motility (ELM) assay that will contribute to the study of lymphangiogenesis. The experimental setup consists of extending the coating of the flask with extracellular matrix (ECM) proteins also at the area opposite to the cap, where the LECs will be initially seeded at various densities. The day after, the flasks will be inclined at an angle of about 20° to cover the entire coated surface. Twenty-four hours later, flasks will be moved to the standard position, and the motility of the cells will be easily observed. Using the ELM assay, we were able to compare the motility rate of LECs isolated from different origins, or seeded on different substrates.

CONCLUSION

We propose the use of a new method to evaluate the motility of LECs: the ELM assay. This cost-effective analysis has several advantages: It can be easily set up in any cell biology laboratory, can be carried out rapidly, and allows the monitoring of cellular motility for a long period.