Selective accumulation of PpIX and photodynamic effect after aminolevulinic acid treatment of human adenomyosis xenografts in nude mice

Applications of Photodynamic Therapy in Endometrial Diseases

Photodynamic therapy (PDT) is a medical procedure useful for several benign conditions (such as wound healing and infections) and cancer. PDT is minimally invasive, presents few side effects, good scaring, and is able to minimal tissue destruction maintaining organ anatomy and function. Endoscopic access to the uterus puts PDT in the spotlight for endometrial disease treatment. This work systematically reviews the current evidence of PDT’s potential and usefulness in endometrial diseases. Thus, this narrative review focused on PDT applications for endometrial disease, including reports regarding in vitro, ex vivo, animal, and clinical studies. Cell lines and primary samples were used as in vitro models of cancer, adenomyosis and endometrioses, while most animal studies focused the PDT outcomes on endometrial ablation. A few clinical attempts are known using PDT for endometrial ablation and cancer lesions. This review emphasises PDT as a promising field of research. This therapeutic approach has the potential to become an effective conservative treatment method for endometrial benign and malignant lesions. Further investigations with improved photosensitisers are highly expected.

Animal Models of Adenomyosis

Adenomyosis is a nonmalignant uterine disorder in which endometrial tissue exists within and grows into the myometrium. Animal models have generated limited insight into the still-unclear pathogenesis of adenomyosis, provided a platform for preclinical screening of many drugs and compounds with potential as therapeutics, and elucidated mechanisms underlying the pain and fertility issues that occur in many women with the disease. Spontaneous adenomyosis has been studied in nonhuman primates, primarily in the form of case reports. Adenomyosis is routinely experimentally induced in mice through methods such as neonatal tamoxifen exposure, pituitary engraftment, and human tissue xenotransplantation. Several studies have also reported hormonal or environmental toxicant exposures that give rise to murine adenomyosis, and genetically engineered models have been created that recapitulate the human-like condition, most notably involving alteration of β-catenin expression. This review describes the animal models for adenomyosis and their contributions to our understanding of the factors underpinning the development of symptoms. Animal models represent a unique opportunity for understanding the molecular basis of adenomyosis and developing efficacious treatment options for affected women. Herein, we assess their different potentials and limitations with regard to identification of new therapeutic interventions and reflect on future directions for research and drug validation.

Photodiagnosis and photodynamic therapy of endometriotic epithelial cells using 5-aminolevulinic acid and steroids

BACKGROUND

The photodynamic diagnosis and therapy represent relatively new methods used, i.a., in the detection of some preneoplastic and neoplastic conditions. They are based on selective accumulation of photosensitizers in the altered cells, which can be identified by fluorescence of the sensitizers and, using light of an appropriate wavelength, can be eliminated. Currently, investigations continue on application of the methods in diagnosis and therapy of endometriosis, one of the most prevalent causes of a reduced fertility in women.

METHODS

In this study protoporphyrin IX, a photosensitizer derived from 5-aminolevulinic acid, was used to locate and destroy endometrial epithelium. Material for the investigations involved primary epithelial cells, isolated from 15 normal endometria and 15 ovarian endometriotic epithelia. Taking into account the cyclical hormonal alterations, which affect endometrial cells in individual phases of the menstrual cycle, experiments were conducted on accumulation of the photosensitizer and photodestruction of the cells preceded by their hormonal stimulation (17β-estradiol and progesterone).

RESULTS AND CONCLUSION

It was found that following 48 h stimulation with 17β-estradiol and/or progesterone a significantly augmented synthesis of protoporphyrin IX can be obtained in cells of endometrial epithelium as compared to the normal epithelium. Moreover, the endometriotic epithelial cells were most effectively eliminated following 48 h prestimulation with progesteron alone. The obtained result permits to assume that photodynamic diagnosis and photodynamic therapy of endometrial epithelium should be performed in the secretory phase of endometrium in order to optimise their results.