Xenotransplantation of uterine leiomyoma in Wistar rats: a pilot study

Pre-clinical models to study abnormal uterine bleeding (AUB)

Abnormal Uterine Bleeding (AUB) is a common debilitating condition that significantly reduces quality of life of women across the reproductive age span. AUB creates significant morbidity, medical, social, and economic problems for women, their families, workplace, and health services. Despite the profoundly negative effects of AUB on public health, advancement in understanding the pathophysiology of AUB and the discovery of novel effective therapies is slow due to lack of reliable pre-clinical models. This review discusses currently available laboratory-based pre-clinical scientific models and how they are used to study AUB. Human and animal in vitro, ex vivo, and in vivo models will be described along with advantages and limitations of each method.

Use of hypertonic glucose (10%) in the prevention of postoperative adhesions in rats

Purpose

To evaluate the efficacy of hypertonic glucose (10%), alone or in combination with the corticoid dexamethasone, to prevent peritoneal adhesion following hysterectomy in rats.

Methods

Forty-two adult rats underwent hysterectomy with peritoneal lavage: G1 – glucose (10%); G2 – glucose (10%) and dexamethasone 3 mg·kg^–1; and G3 – physiological saline (PS) 0.9%.

Results

In the macroscopic analysis after 14 days, G1 had a median score of 1, G2 of 1, and G3 of 2.5 (p < 0.0001), G3 compared to G1 and G2. There was no difference between groups after 28 days. In the microscopic analysis, the median vascular proliferation after 14 days was 2 for G1, 1 for G2, and 3 for G3 (p = 0.0037, G3 vs. G1 and G2). After 28 days, G1 showed a median vascular proliferation score of 2, G2 of 2.5, and G3 of 3 (p < 0.0001, G3 vs. G1 and G2). Regarding the inflammatory reaction after 14 days, G1 had a median score of 2, G2 of 1, and G3 of 3 (p = 0.7916). After 28 days, G1 had a median score of 0.5 (0–1.75), G2 of 1.5, and G3 of 2.5 (p < 0.0001, G3 vs. the others and G2 vs. G1). In the evaluation of fibrosis after 14 days, G1 had a median score of 1, G2 of 1, and G3 of 2.5 (p < 0.0001, G3 vs. G1and G2). After 28 days, G1 had a median fibrosis score of 1, G2: 2, and G3: 2.5 (p < 0.0001), G3 vs. the others andG2 vs. G1).

Conclusions

The use of hypertonic glucose (10%) solution seems to reduce macroscopic and microscopic pelvic adhesions.

Development and Validation of Hormonal Impact of a Mouse Xenograft Model for Human Uterine Leiomyoma

Multiple in vivo animal models for uterine leiomyoma do not adequately represent human disease based on etiology, molecular phenotype, or limited fixed life span. Our objective was to develop a xenograft model with sustained growth, by transplanting a well-established actively growing three-dimensional (3D) cell culture of human leiomyoma and myometrium in NOD/SCID ovariectomized female mice. We demonstrated continued growth to at least 12 weeks and the overexpression of extracellular matrix (ECM). Further, we confirmed maintenance of hormonal response that is comparable to human disease in situ. Leiomyoma xenografts under hormonal treatment demonstrated 8 to12-fold increase of volume over the xenografts not treated with hormones. Estradiol-treated xenografts were more cellular as compared to progesterone or combination milieu, at the end of 8-week time frame. There was also a non-statistically significant 2-4 mm³ increase in volume between 8-week and 12-week xenografts with higher matrix to cell ratio in 12-week xenografts compared to the 8-week and placebo xenografts. Increased expression of ECM proteins, fibronectin, versican, and collagens, indicated an actively growing cell matrix formation in the xenografts. In conclusion, we have developed and validated a xenograft in vivo model for uterine leiomyoma that shares the genomic and proteomic characteristics with the human surgical specimens of origin and recapitulates the most important features of the human tumors, the aberrant ECM expression that defines the leiomyoma phenotype and gonadal hormone regulation. Using this model, we demonstrated that combination of estradiol and progesterone resulted in increased cellularity and ECM production leading to growth of the xenograft tumors.