Leiomyoma and Vascular Endothelial Growth Factor Gene Polymorphisms: A Systematic Review

Open Gastrostomy of a Gastric Leiomyoma Proximal to the Gastroesophageal Junction: A Case Report

Gastric leiomyomas are benign, submucosal tumors found incidentally on unrelated imaging or during autopsy. The majority of leiomyomas are asymptomatic; however, patients can develop central ulcerations on the lesions leading to upper gastrointestinal (GI) bleeding. A 75-year-old female, with a past medical history of hypertension, hyperlipidemia, and a cerebrovascular accident, presented with complaints of melena, near-syncope events, lightheadedness, weakness, and hematemesis. A computed tomography (CT) of the abdomen with contrast found a heterogeneous low-attenuation mass of 4×4×3 cm3 within the gastric fundus and near the gastroesophageal (GE) junction. After an open gastrostomy and excisional biopsy, the mass was identified as a leiomyoma. This case report reviews the presentation, diagnostic assessments, and treatment of a gastric leiomyoma in a complex location proximal to the gastroesophageal junction. Gastric leiomyomas should be considered as a differential diagnosis for patients presenting with an upper gastrointestinal bleed.

Rare Presentation of Small Bowel Obstruction Secondary to Intestinal Leiomyoma in a Patient with Crohn's Disease

Small bowel obstructions (SBOs) are surgical emergencies that can occur with mechanical blockage of the intestinal lumen. These blockages are most commonly caused by adhesions or hernias, but can also result from intestinal neoplasms. This case report documents the rare occurrence of SBO due to a submucosal leiomyoma. This case was complicated by the patient's longstanding history of Crohn's disease, which has a considerable overlap in symptomatology with SBOs. This may have resulted in a delay in the patient's diagnosis. Leiomyomas should always be considered as a potential, albeit rare, cause of SBO.

SATB2 and NGR1: potential upstream regulatory factors in uterine leiomyomas

PURPOSE

We attempted to identify the genes involved in the pathogenesis of uterine leiomyomas, under a hypothesis that the aberrant expression of upstream regulatory genes caused by aberrant DNA methylation is involved in the onset and development of uterine leiomyomas.

METHODS

To find such genes, we compared genome-wide mRNA expression and DNA methylation in uterine leiomyomas and adjacent normal myometrium. Analysis of the data by Ingenuity Pathway Analysis software identified SATB2 which is known to be an epigenetic regulator, and NRG1 as candidate upstream regulatory genes. To infer the functions of these genes, human uterine smooth muscle cell lines overexpressing SATB2 or NRG1 genes were established (SATB2 or NRG1 lines), and their transcriptomes and pathways were analyzed.

RESULTS

SATB2 and NRG1 were confirmed to be hypermethylated and upregulated in most uterine leiomyoma specimens (nine to 11 of the 11 cases). Among the established cell lines, morphological changes from spindle-like forms to fibroblast-like forms with elongated protrusions were observed in only the SATB2 line. Pathway analysis revealed that WNT/β-catenin and TGF-β signaling pathways which are related to the pathogenesis of uterine leiomyomas were activated in both SATB2 and NRG1 lines. In addition, signaling of growth factors including VEGF, PDGF, and IGF1, and retinoic acid signaling were activated in the SATB2 and NRG1 lines, respectively.

CONCLUSIONS

These results indicate that SATB2 and NRG1 overexpression induced many of the signaling pathways that are considered to be involved in the pathogenesis of uterine leiomyomas, suggesting that these genes have roles as upstream regulatory factors.

Effects of liver depression and psychological stress on human uterine leiomyoma cells by an AR-cAMP-PKA signal transduction pathway

OBJECTIVE

Based on the emotional theory of Traditional Chinese Medicine, and combined with the modern medicine theory of psychological stress, a research model of human uterine leiomyoma cells (ULM) was cultured in vitro to determine the effectiveness of adrenergic receptor (AR) agonists in human ULM cell growth. In addition, we studied the functional influence of "liver depression and psychological stress theory" on fibroid formation by intervening in the AR-cAMP-PKA signaling pathway. The intention was to establish a new method to prevent and cure fibroids through "liver depression and psychological stress theory" and provide an experimental basis for the Traditional Chinese Medicine emotional theory.

MATERIALS AND METHODS

Primary human ULM cells were enriched by collagenase digestion. Immunohistochemistry and hematoxylin and eosin (HE) staining were used for cytological identification. Using this model, we studied intervention using specific AR agonists on ULM cells to observe the influence of "liver depression and psychological stress theory" on estrogen receptor (ER), progesterone receptor (PR), vascular endothelial growth factor (VEGF) and fibroblast growth factors (FGF).

RESULTS

Norepinephrine (NE) and epinephrine (E) are adrenergic receptor agonists. They promoted ULM cell proliferation and increased the levels of ER, PR, VEGF and FGF. In contrast, isoproterenol (ISO) inhibited ULM cell proliferation and decreased the levels of ER, PR, VEGF and FGF. The protein expression of cAMP and PKA in ULM cells was reduced and the levels of ER, PR, VEGF and FGF were increased when co-treatment with the α-AR blocker (phentolamine). The β-AR blocker (metoprolol) displayed an opposite effect.

CONCLUSIONS

AR agonists modulated ER, PR, VEGF and FGF levels in ULM cells in an AR-cAMP-PKA-dependent signaling pathways to influence fibroid occurrence and development.

A network pharmacology approach to investigate the pharmacological effects of Guizhi Fuling Wan on uterine fibroids

To investigate the pharmacological mechanism of Guizhi Fuling Wan (GFW) in the treatment of uterine fibroids, a network pharmacology approach was used. Information on GFW compounds was collected from traditional Chinese medicine (TCM) databases, and input into PharmMapper to identify the compound targets. Genes associated with uterine fibroids genes were then obtained from the GeneCards and Online Mendelian Inheritance in Man databases. The interaction data of the targets and other human proteins was also collected from the STRING and IntAct databases. The target data were input into the Database for Annotation, Visualization and Integrated Discovery for gene ontology (GO) and pathway enrichment analyses. Networks of the above information were constructed and analyzed using Cytoscape. The following networks were compiled: A compound-compound target network of GFW; a herb-compound target-uterine fibroids target network of GWF; and a compound target-uterine fibroids target-other human proteins protein-protein interaction network, which were subjected to GO and pathway enrichment analyses. According to this approach, a number of novel signaling pathways and biological processes underlying the effects of GFW on uterine fibroids were identified, including the negative regulation of smooth muscle cell proliferation, apoptosis, and the Ras, wingless-type, epidermal growth factor and insulin-like growth factor-1 signaling pathways. This network pharmacology approach may aid the systematical study of herbal formulae and make TCM drug discovery more predictable.

Signaling Pathways in Leiomyoma: Understanding Pathobiology and Implications for Therapy

Uterine leiomyomas are the most common tumors of the female genital tract, affecting 50% to 70% of females by the age of 50. Despite their prevalence and enormous medical and economic impact, no effective medical treatment is currently available. This is, in part, due to the poor understanding of their underlying pathobiology. Although they are thought to start as a clonal proliferation of a single myometrial smooth muscle cell, these early cytogenetic alterations are considered insufficient for tumor development and additional complex signaling pathway alterations are crucial. These include steroids, growth factors, transforming growth factor-beta (TGF-β)/Smad; wingless-type (Wnt)/β-catenin, retinoic acid, vitamin D, and peroxisome proliferator-activated receptor γ (PPARγ). An important finding is that several of these pathways converge in a summative way. For example, mitogen-activated protein kinase (MAPK) and Akt pathways seem to act as signal integrators, incorporating input from several signaling pathways, including growth factors, estrogen and vitamin D. This underlines the multifactorial origin and complex nature of these tumors. In this review, we aim to dissect these pathways and discuss their interconnections, aberrations and role in leiomyoma pathobiology. We also aim to identify potential targets for development of novel therapeutics.

Effect of lichong decoction on expression of IGF-I and proliferating cell nuclear antigen mRNA in rat model of uterine leiomyoma

OBJECTIVE

To study the effect of Lichong Decoction (Lichong Decoction for strengthening anti-pathogenic Qi and eliminating blood stasis) on the expression of insulin-like growth factor-I (IGF-I) and proliferating cell nuclear antigen (PCNA) mRNA in a rat model of uterine leiomyoma.

METHODS

Fifty female Wistar rats were randomized into a normal control group, model group, Lichong Decoction group, Guizhifuling Capsule (Capsule containing Cassia Twig and Poria) group, and Mifepristone group. The uterine leiomyoma model was established by peritoneal injections of exogenous estrogen and progesterone hormone. The ultrastructural changes in cells of rat uterine tissues were observed with transmission electron microscopy, and the expression of IGF-I and PCNA mRNA was detected by real-time fluorescent quantitative PCR.

RESULTS

Following treatment, cells in the Lichong Decoction group appeared to be arranged normally, the cellular morphology were almost in a normal state, hyperplasia and hypertrophy of the chondriosome was reduced, collagen fibers were arranged in a regular manner, without obvious hyperplasia, and the expression of IGF-I and PCNA mRNA was significantly decreased compared with the model group (P < 0.01).

CONCLUSIONS

The effect of Lichong Decoction on uterine leiomyoma is related to its function in reducing the expression of IGF-I and PCNA mRNA.

Does vascular endothelial growth factor participate in uterine myoma growth stimulation?

OBJECTIVE

Peptide growth factors play a role in the rebuilding of extracellular matrix in the course of leiomyoma growth, and exert a regulative effect on the cell only when they bind with a specific membrane receptor and transmit a signal into the cell. A high content of certain peptide growth factors and their receptors in leiomyoma suggests that in the course of the tumour growth hyperstimulation of cells takes place. A combined action of various peptide growth factors causes an amplification of signal paths in cells, inducing gene expression of proteins responsible for cell division and changes of metabolism. We therefore decided to evaluate the amounts and expression of VEGF, their receptor and mRNA levels.

STUDY DESIGN

Studies were performed on human myometrium and uterine leiomyomas of various weights (small: i.e. less than 10 g, and large: i.e. more than 100 g). Expression and content of VEGF-A, D and VEGF R-1, R-2 were analysed with Western blot and ELISA methods, respectively. The RT-PCR method was used to determine VEGF mRNA levels.

RESULTS

Our immunoblotting studies and immunoenzymatic assay, as well as RT-PCR technique, did not detect significant differences in the expression of VEGFs and their receptors in control myometrium and in uterine leiomyomas.

CONCLUSION

The increase in the amount of some peptide growth factors, especially FGFs and IGF-I, in large leiomyomas without any change in VEGF content means a decrease in the proportional relationship of the latter to other growth factors. Stimulation of extracellular matrix formation seems stronger than angiogenesis during myoma growth.