SKIN AND SUBCUTANEOUS ADIPOSE TISSUE DAMAGE AFTER RADIATION THERAPY IN BREAST CANCER PATIENTS

The analysis of long-term researches of the pathological changes arising in soft tissues at patients with a breast cancer as a result of radical surgical treatment and adjuvant radiotherapy is carried out in work. The article shows that the standard approach to postoperative radiation therapy, which is based only on the prevalence of the primary tumor process is not always justified. Very often it leads to excessive radiation load on the patient's body and the development of local acute and chronic radiation reactions of the skin, subcutaneous tissue and other soft tissues.In this regard, the question of differentiated purpose of radiotherapy acquires special value first of all at patients with small primary prevalence of tumor process. The paper presents the results of studies to study changes in the anterior chest wall in patients with breast cancer. In relation to the conduct of adjuvant radiotherapy more often need to use the concept of personalized radiation therapy. Radical operation, post-radiation early and late pathological changes in soft tissues, disturbance of microcirculation of lymph and blood, disturbance of innervation of vessels of an upper extremity, peripheral nerves in system of a cervical and plexus plexus, leads to intensive degen-erative and dystrophic changes in soft tissues of the upper. and causes morphological changes in them and further progression of reflex neurovascular and neurodystrophic disorders. Based on the data of adverse effects of radio-therapy on the skin and surrounding tissues, as well as to reduce excessive radiation exposure to the patient's body, a differentiated approach to the appointment of adjuvant radiation therapy.

PNPLA1 defects in patients with autosomal recessive congenital ichthyosis and KO mice sustain PNPLA1 irreplaceable function in epidermal omega-O-acylceramide synthesis and skin permeability barrier

Autosomal recessive congenital ichthyosis (ARCI) is a heterogeneous group of monogenic genodermatoses that encompasses non-syndromic disorders of keratinization. The pathophysiology of ARCI has been linked to a disturbance in epidermal lipid metabolism that impaired the stratum corneum function, leading to permeability barrier defects. Functional characterization of some genes involved in ARCI contributed to the identification of molecular actors involved in epidermal lipid synthesis, transport or processing. Recently, PNPLA1 has been identified as a gene causing ARCI. While other members of PNPLA family are key elements in lipid metabolism, the function of PNPLA1 remained unclear. We identified 5 novel PNPLA1 mutations in ARCI patients, mainly localized in the putative active enzymatic domain of PNPLA1. To investigate Pnpla1 biological role, we analysed Pnpla1-deficient mice. KO mice died soon after birth from severe epidermal permeability defects. Pnpla1-deficient skin presented an important impairment in the composition and organization of the epidermal lipids. Quantification of epidermal ceramide species highlighted a blockade in the production of ω-O-acylceramides with a concomitant accumulation of their precursors in the KO. The virtually loss of ω-O-acylceramides in the stratum corneum was linked to a defective lipid coverage of the resistant pericellular shell encapsulating corneocytes, the so-called cornified envelope, and most probably disorganized the extracellular lipid matrix. Finally, these defects in ω-O-acylceramides synthesis and cornified envelope formation were also evidenced in the stratum corneum from PNPLA1-mutated patients. Overall, our data support that PNPLA1/Pnpla1 is a key player in the formation of ω-O-acylceramide, a crucial process for the epidermal permeability barrier function.