Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A hereditary form of colon cancer, hereditary non-polyposis colon cancer (HNPCC), is characterized by high instability of short repeated sequences known as microsatellites. Because the genes controlling microsatellite stability were known in bacteria and yeast, as was their evolutionary conservation, the search for human genes responsible for HNPCC became a 'targeted' search for known sequences. Mismatch-repair deficiency in bacteria and yeast produces multiple phenotypes as a result of its dual involvement in the editing of both replication errors and recombination intermediates. In addition, mismatch-repair functions are specialized in eukaryotes, characterized by specific mitotic (versus meiotic) functions, and nuclear (versus mitochondrial) localization. Given the number of phenotypes observed so far, we predict other links between mismatch-repair deficiency and human genetic disorders. For example, a similar type of sequence instability has been found in HNPCC tumours and in a number of neuro-muscular genetic disorders. Several human mitochondrial disorders display genomic instabilities reminiscent of yeast mitochondrial mismatch-repair mutants. In general, the process of mismatch repair is responsible for the constant maintenance of genome stability and its faithful transmission from one generation to the next. However, without genetic alteration, species would not be able to adapt to changing environments. It appears that nature has developed both negative and positive controls for genetic diversity. In bacteria, for example, an inducible system (sos) exists which generates genetic alterations in response to environmental stress (e.g. radiation, chemicals, starvation). Hence, the cost of generating diversity to adapt to changing conditions might be paid as sporadic gene alterations associated with disease.
 ...
PMID:Editing DNA replication and recombination by mismatch repair: from bacterial genetics to mechanisms of predisposition to cancer in humans. 774 61

Juvenile polyposis of infancy is a rare genetic disorder, involving multiple hamartomatous polyps of the gastrointestinal tract, which usually has a very aggressive clinical course and is often fatal. It is characterized by early onset (during the 1st months of life) and by diffuse juvenile polyposis with anemia, recurrent gastrointestinal bleeding, diarrhea, rectal prolapse, intussusception, protein-losing enteropathy, starvation, and malnutrition. There is a hypothesis that mutation of the tumor-suppressor genes BMPR1A and PTEN, located on the long arm of chromosome 10, is associated with the development of this disease. Medical treatment for this disorder is challenging and should be conservative whenever possible. We present the case of a 3-year-old girl with juvenile polyposis of infancy who eventually died from mesenteric artery thrombosis during surgical colectomy. Karyotype of the patient showed a paracentric inversion in 10q and a deletion in 10p. We will briefly comment on some genetic considerations of this disease.
 ...
PMID:Juvenile polyposis of infancy associated with paracentric inversion and deletion of chromosome 10 in a Hispanic patient: a case report. 2033 46

Mutations in the serine-threonine kinase (LKB1) lead to a gastrointestinal hamartomatous polyposis disorder with increased predisposition to cancer (Peutz-Jeghers syndrome). LKB1 has many targets, including the AMP-activated protein kinase (AMPK) that is phosphorylated under low-energy conditions. AMPK phosphorylation in turn, affects several processes, including inhibition of the target of rapamycin (TOR) pathway, and leads to proliferation inhibition. To gain insight into how LKB1 mediates its effects during development, we generated zebrafish mutants in the single LKB1 ortholog. We show that in zebrafish lkb1 is dispensable for embryonic survival but becomes essential under conditions of energetic stress. After yolk absorption, lkb1 mutants rapidly exhaust their energy resources and die prematurely from starvation. Notably, intestinal epithelial cells were polarized properly in the lkb1 mutants. We show that attenuation of metabolic rate in lkb1 mutants, either by application of the TOR inhibitor rapamycin or by crossing with von Hippel-Lindau (vhl) mutant fish (in which constitutive hypoxia signaling results in reduced metabolic rate), suppresses key aspects of the lkb1 phenotype. Thus, we demonstrate a critical role for LKB1 in regulating energy homeostasis at the whole-organism level in a vertebrate. Zebrafish models of Lkb1 inactivation could provide a platform for chemical genetic screens to identify compounds that target accelerated metabolism, a key feature of tumor cells.
 ...
PMID:The serine-threonine kinase LKB1 is essential for survival under energetic stress in zebrafish. 2136 12