Endostatin Gene Therapy for Endometriosis in Rats

Single-cell transcription analysis reveals the tumor origin and heterogeneity of human bilateral renal clear cell carcinoma

Bilateral renal clear cell carcinoma (BRCC) is a rare type of renal cell carcinoma (RCC) that accounts for only 1-5% of RCC cases and has a poor clinical prognosis. The origin, tumor microenvironment, cellular molecular features, and intra-tumoral heterogeneity of BRCC are still unclear. We downloaded BRCC single-cell transcriptome sequencing data from the gene expression omnibus database biochip GSE171306, containing 3,575 cells from left-sided clear cell renal cell carcinoma (ccRCC) and 3,568 cells from right-sided ccRCC, and used a series of R packages for data quality control (QC) and subsequent analysis of BRCC single-cell transcriptome data, including the use of the R packages Seurat and scCancer for cell QC, identification of major cell types, and cell annotation; R package scran for calculation of cell cycle scores; R package infercnv for malignancy scoring of tumor cells; R package ReactomeGSA for functional enrichment analysis; R package Monocle 2 for the analysis of cell differentiation trajectories; and R package CellphoneDB for the analysis of intercellular interactions. In this study, by analyzing the high-quality single-cell transcriptome data of BRCC, we identified 18 cell types and found that left- and right-sided ccRCC were approximately the same in terms of cell type and the number of each cell but differed significantly in terms of tumor cell malignancy score, tumor microenvironment, and cell stemness score. In the cell differentiation trajectory analysis of BRCC, we found that endothelial cells and macrophages play an extremely important role in its tumor progression. Further cell communication analysis was performed, and we found that it may signal through ligand-receptors, such as vascular endothelial growth factor-vascular endothelial growth factor receptor1 (VEGF-VEGFR1), MIF-(CD74-CXCR4), and growth arrest-specific protein 6-AXL, to influence the development of BRCC. The analysis of single-cell transcriptomic data of human BRCC suggests that left- and right-sided ccRCC may be of the same tumor origin, but the left-sided ccRCC is more malignant and has a better immune response.

New developments in the medical treatment of endometriosis

Endometriosis affects 1 in 10 women of reproductive-age. The current treatments are surgical and hormonal but have limitations, including the risk of recurrence, side effects, contraceptive action for women who desire pregnancy, and cost. New treatments include gonadotropin-releasing hormone analogues, selective progesterone (or estrogen) receptor modulators, aromatase inhibitors, immunomodulators, and antiangiogenic agents. Further research is needed into central sensitization, local neurogenesis, and the genetics of endometriosis to identify additional treatment targets. A wider range of medical options allows for the possibility of precision health and a more personalized treatment approach for women with endometriosis.

Efficacy of Anti-VEGF/VEGFR Agents on Animal Models of Endometriosis: A Systematic Review and Meta-Analysis

Background/Objective

Vascular endothelial growth factor (VEGF) is the most important promotor of angiogenesis. Some studies indicate that anti-angiogenic agents that interfere with VEGF and its receptor (VEGFR), i.e., anti-VEGF/VEGFR agents, may be applied to treat endometriosis. This meta-analysis investigated the efficacy of anti-VEGF/VEGFR agents in animal models of endometriosis.

Methods

A systematic literature search was performed for animal studies published in English or Chinese from January 1995 to June 2016, which evaluated the effect of anti-VEGF/VEGFR agents on endometriosis. The databases were: PubMed, Web of Science, BIOSIS, Embase, and CNKI. The quality of included studies was assessed using the SYRCLE tool. The random-effect models were used to combine the results of selected studies. Heterogeneity was assessed using H²statistic and I² statistic. Subgroup analyses were performed to determine the source of heterogeneity in endometriosis scores and follicle numbers.

Results

We identified 13 studies that used anti-VEGF/VEGFR agents in various animal models. The meta-analysis showed that anti-VEGF/VEGFR agents were associated with smaller size (standardized mean difference (SMD) –0.96, 95% CI –1.31 to –0.62; P < 0.0001) and weight (SMD –1.70, 95% CI –2.75 to –0.65; P = 0.002) of endometriosis lesions, relative to the untreated controls, as well as a lower incidence rate of endometriosis (risk ratio 0.26, 95% CI 0.07 to 0.93; P = 0.038) and endometriosis score (SMD –1.17, 95% CI –1.65 to –0.69; P < 0.0001); the number of follicles were similar (SMD –0.78, 95% CI –1.65 to 0.09; P = 0.08).

Conclusions

Anti-VEGF/VEGFR agents appeared to inhibit the growth of endometriosis, with no effect on ovarian function. Anti-angiogenic therapy may be a novel strategy in treating endometriosis.

Endostatin's emerging roles in angiogenesis, lymphangiogenesis, disease, and clinical applications

BACKGROUND

Angiogenesis is the process of neovascularization from pre-existing vasculature and is involved in various physiological and pathological processes. Inhibitors of angiogenesis, administered either as individual drugs or in combination with other chemotherapy, have been shown to benefit patients with various cancers. Endostatin, a 20-kDa C-terminal fragment of type XVIII collagen, is one of the most potent inhibitors of angiogenesis.

SCOPE OF REVIEW

We discuss the biology behind endostatin in the context of its endogenous production, the various receptors to which it binds, and the mechanisms by which it acts. We focus on its inhibitory role in angiogenesis, lymphangiogenesis, and cancer metastasis. We also present emerging clinical applications for endostatin and its potential as a therapeutic agent in the form a short peptide.

MAJOR CONCLUSIONS

The delicate balance between pro- and anti-angiogenic factors can be modulated to result in physiological wound healing or pathological tumor metastasis. Research in the last decade has emphasized an emerging clinical potential for endostatin as a biomarker and as a therapeutic short peptide. Moreover, elevated or depressed endostatin levels in diseased states may help explain the pathophysiological mechanisms of the particular disease.

GENERAL SIGNIFICANCE

Endostatin was once sought after as the 'be all and end all' for cancer treatment; however, research throughout the last decade has made it apparent that endostatin's effects are complex and involve multiple mechanisms. A better understanding of newly discovered mechanisms and clinical applications still has the potential to lead to future advances in the use of endostatin in the clinic.