Neoplasic growth and pregnancy: hormonal profile and placental alterations in pregnant tumor-bearing rats

Author(s)

Angela Luzia Drezza

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2008-08-15

Examining board members

Maria Cristina Cintra Gomes Marcondes; Maria Alice Rostom de Mello; Miguel Arcanjo Areas

• Advisor: Maria Cristina Cintra Gomes Marcondes

Abstract

Pregnancy causes several modifications in the maternal organism for the blastocistic implantation that are made by hormonal action, as oestradiol and progesterone. The pregnancy progress depends on the placenta, maternal / foetal unit, which exchanges nutrients, gas and substances between mother and foetus, and can produce a variety of hormones, like prolactin, oestrogen and progesterone. The association between pregnancy and tumoral growth, two situations that involve intense cell multiplication, can be extremely harmful for the foetus development. Sex hormones and prolactin have their concentrations modified during normal gestational progress and can also interact and modulate many physiological functions, as well as immune cells. In turn, tumour growth can raise body cytokines that may influence the hormones necessary to pregnancy and placenta development. In this work we analyzed 3 experimental groups (Control - pregnant rats without tumour, Tumour - pregnant tumour-bearing rats and Ascitic - pregnant rats inoculated with ascitic fluid daily) evaluating the placental morphometry, serum hormonal concentration (oestrogen, progesterone and prolactin), immunohistochemistry, protein expression of the placental oestrogen and progesterone receptors, and also measurements of ín vítro assays of protein synthesis and degradation and placenta's hormonal biosynthesis. Tumour group animais presented, when compared to the Control group, low foetus weight, molecular and morphological placenta alterations and abnormal pregnancy hormone variation (decrease in progesterone levels and increase in prolactin and oestrogen content). Animais of the ascitic fluid group also showed similar abnormal variation of these hormones in the pregnancy as observed in thé Tumour group, indicating that some factors contained in the ascitic fluid could be the greatest responsible for these alterations. Moreover, when compared to the Control group, the ascitic fluid group also presented low foetus weight and molecular and morphological placenta alterations. Since the ascitic fluid group was not tumour host and, therefore, have no nutritional competition between foetus and tumoral cells, the results allowed to observe the direct and/or indirect effects of the factors produced by the host tissue or tumoral cells. These effects included reduction of trophoblastic giants cells and decidual and trophoblastic layers, less placental and foetal oestrogen and progesterone receptor protein expression and reduced foetal weight. We concluded that humoral effectors from hosts immune system or produced by the tumour cells are able to cause pathological conditions and, during pregnancy, can also cause damages to the placental and foetal development. (AU)