title: Dietary leucine supplementation minimises tumour-induced damage in placental tissues of pregnant, tumour-bearing rats.
abstract: BACKGROUND
  The occurrence of cancer during pregnancy merges two complex, poorly understood metabolic and hormonal conditions. This association can exacerbate the conditions of both the mother and the foetus. The branched-chain amino acid leucine enhances cellular activity, particularly by increasing protein synthesis. This study aimed to analyse the modulatory effect of a leucine-rich diet on direct and indirect tumour-induced placental damage. This was accomplished by evaluating the expression of genes involved in protein synthesis and degradation and assessing anti-oxidant enzyme activity in placental tissues collected from pregnant, tumour-bearing rats.
  
  
  RESULTS
  Pregnant rats were either implanted with Walker 256 tumour cells or injected with ascitic fluid (to study the indirect effects of tumour growth) and then fed a leucine-rich diet. Animals in a control group underwent the same procedures but were fed a normal diet. On the 20(th) day of pregnancy, tumour growth was observed. Dams fed a normoprotein diet showed the greatest tumour growth. Injection with ascitic fluid mimicked the effects of tumour growth. Decreased placental protein synthesis and increased protein degradation were observed in both the tumour-bearing and the ascitic fluid-injected groups that were fed a normoprotein diet. These effects resulted in low placental DNA and protein content and high lipid peroxidation (measured by malondialdehyde content). Decreased placental protein synthesis-related gene expression was observed in the tumour group concomitant with increased expression of genes encoding protein degradation-associated proteins and proteolytic subunits.
  
  
  CONCLUSIONS
  Consumption of a leucine-rich diet counteracted the effects produced by tumour growth and injection with ascitic fluid. The diet enhanced cell signalling, ameliorated deficiencies in DNA and protein content, and balanced protein synthesis and degradation processes in the placenta. The improvements in cell signalling included changes in the mTOR/eIF pathway. In conclusion, consumption of a leucine-rich diet improved placental metabolism and cell signalling in tumour-bearing rats, and these changes reduced the deleterious effects caused by tumour growth.
authors: Department of Structural and Functional Biology, Biology Institute, State University of Campinas, UNICAMP, CP 6109, Campinas, São Paulo, 13083862, Brazil. bread.cruz@gmail.com.
authors: Bread Leandro Gomes
authors: BL
authors: Cruz
authors: Department of Structural and Functional Biology, Biology Institute, State University of Campinas, UNICAMP, CP 6109, Campinas, São Paulo, 13083862, Brazil. prisilva@unicamp.br.
authors: Priscila Cristina
authors: PC
authors: da Silva
authors: Department of Structural and Functional Biology, Biology Institute, State University of Campinas, UNICAMP, CP 6109, Campinas, São Paulo, 13083862, Brazil. rebekatomasin@gmail.com.
authors: Rebeka
authors: R
authors: Tomasin
authors: Department of Structural and Functional Biology, Biology Institute, State University of Campinas, UNICAMP, CP 6109, Campinas, São Paulo, 13083862, Brazil. a031176@dac.unicamp.br.
authors: Andre Gustavo
authors: AG
authors: Oliveira
authors: Department of Structural and Functional Biology, Biology Institute, State University of Campinas, UNICAMP, CP 6109, Campinas, São Paulo, 13083862, Brazil. lala_viana@yahoo.com.br.
authors: Lais Rosa
authors: LR
authors: Viana
authors: Department of Structural and Functional Biology, Biology Institute, State University of Campinas, UNICAMP, CP 6109, Campinas, São Paulo, 13083862, Brazil. emisalomao@hotmail.com.
authors: Emilianne Miguel
authors: EM
authors: Salomao
authors: Department of Structural and Functional Biology, Biology Institute, State University of Campinas, UNICAMP, CP 6109, Campinas, São Paulo, 13083862, Brazil. cintgoma@unicamp.br.|, Rua Monteiro Lobato, 255, Campinas, Zip code 13083862, Brazil. cintgoma@unicamp.br.
authors: Maria Cristina Cintra
authors: MC
authors: Gomes-Marcondes
mesh_terms: D000818:Animals; D002279:Carcinoma 256, Walker / Q000178:diet therapy* / Q000235:genetics / Q000473:pathology; D019587:Dietary Supplements; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007930:Leucine / Q000008:administration & dosage*; D008315:Malondialdehyde / Q000378:metabolism; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D010920:Placenta / Q000187:drug effects / Q000473:pathology; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000178:diet therapy* / Q000235:genetics / Q000473:pathology; D051381:Rats
chemical_list: D009363:Neoplasm Proteins; D008315:Malondialdehyde; D007930:Leucine