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

We investigated the effect of modeled microgravity (MMG) on normal vascular smooth muscle cells (VSMC) and neoplastic human breast cancer cells (MCF-7). In both cell types, MMG induced partial arrest in G2M and increased p14-3-3, HSP70, HSP60 and p21 expression. Cells synchronized by 24h starvation reentered the normal cycle within 24h if released in complete medium and exposed to normal gravity, but not if exposed to MMG. Similarly, MMG prevented VSMC and MCF-7 cells from overcoming growth arrest and re-synthesizing DNA. This study shows that cells adjust their metabolic rate in response to MMG.
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PMID:Exposure to modeled microgravity induces metabolic idleness in malignant human MCF-7 and normal murine VSMC cells. 1663 72

Excessive beta-catenin is considered to contribute to tumor progression by inducing transcription of cell cycle-related genes such as cyclin D1 and c-myc. In contrast, our recent studies demonstrated that beta-catenin could inhibit cell proliferation through activation of p14(ARF)/p53/p21(WAF1) pathway during trans-differentiation toward morular phenotype of endometrial carcinoma (Em Ca) cells. Here, we focused on associations with alterations in p16(INK4A) and pRb expression during this process. In clinical cases, p16(INK4A) immunoreactivity was found to frequently overlap with nuclear beta-catenin accumulation in small-sized morules and surrounding glandular carcinomas (Sur-Ca), demonstrating a significant positive correlation (r = 0.447, p < 0.0001) overall, while the immunoreactions showed stepwise decrease in enlarged morules, despite persistent accumulation of beta-catenin and p21(WAF1) in nuclei. Immunoreactivity for both total pRb and its phosphorylated form was apparently decreased in all morules as compared to Sur-Ca lesions, with a significantly positive correlation. In cell lines, transcriptional activation of p16(INK) (4A) promoter by active form beta-catenin, as well as p21(WAF1), occurred through the region from -385 to -280 bp relative to the translation start site, in a TCF4-independent manner. Moreover, cell proliferation was accompanied with phosphorylation of pRb and increased p16(INK4A) expression, while its inhibition by serum starvation caused decreased expression of total pRb but not p16(INK4A), resulting in high relative amounts of the latter. These findings indicate that induction of p16(INK4A) mediated by nuclear beta-catenin and p21(WAF1), along with loss of pRb expression, may be important for initial steps during trans-differentiation of Em Ca cells. In addition, its down-regulation is associated with progression of lesions.
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PMID:Induction of p16INK4A mediated by beta-catenin in a TCF4-independent manner: implications for alterations in p16INK4A and pRb expression during trans-differentiation of endometrial carcinoma cells. 1685 82

p14/p19ARF (ARF) is a tumor suppressor gene that is frequently mutated in human cancer. ARF has multiple tumor suppressor functions, some of which are mediated by signaling to p53. Surprisingly, a significant fraction of human tumors retain persistently high levels of ARF, suggesting that ARF may possess a prosurvival function. We show that ARF protein is markedly up-regulated in cells exposed to nutrient starvation. Cells with silenced ARF show reduced autophagy and reduced viability when placed under conditions of starvation. We show for the first time that ARF silencing can limit the progression of some tumors, such as lymphoma, but not others, such as E1A/Ras-induced tumors. Specifically, myc-driven lymphomas with mutant p53 tend to overexpress ARF; we show that silencing ARF in these tumors greatly impedes their progression. These data are the first to show that ARF can act in a p53-independent manner to promote the progression of some tumors.
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PMID:The ARF tumor suppressor can promote the progression of some tumors. 1904 37

Geometric analysis of the nutritional regulatory responses was performed on an omnivorous mealworm beetle, Tenebrio molitor L. (Coleoptera: Tenebrionidae) to test whether this beetle had the capacity to balance the intake of protein and carbohydrate. We also identified the pattern of ingestive trade-off employed when the insect was forced to balance the costs of over- and under-ingesting macronutrients. When allowed to mix their diet from two nutritionally imbalanced but complementary foods (protein-biased food: p35:c7 or p28:c5.6; carbohydrate-biased food: p7:c35 or p5.6:c28), beetles of both sexes actively regulated their intake of protein and carbohydrate to a ratio of 1:1. When confined to one of seven nutritionally imbalanced foods (p0:c42, p7:c35, p14:c28, p21:c21, p28:c14, p35:c7 or p42:c0), beetles over-ingested the excessive nutrient from these foods to such an extent that all the points of protein-carbohydrate intake aligned linearly in the nutrient space, a pattern that is characteristic of generalist feeders and omnivores. Under the restricted feeding conditions, males ate more nutrients but were less efficient at retaining their body lipids than females. Body lipid content was higher on carbohydrate-rich foods and was positively correlated with starvation resistance. Our results are consistent with the prediction based on the nutritional heterogeneity hypothesis, which links the nutritional regulatory responses of insects to their diet breadth and feeding ecology.
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PMID:Geometric analysis of nutrient balancing in the mealworm beetle, Tenebrio molitor L. (Coleoptera: Tenebrionidae). 2530 81

Human papillomavirus 16 (HPV16) E7 has long been known to stabilize the tumor suppressor TP53. However, the molecular mechanism of TP53 stabilization by HPV16 E7 has remained obscure, and this stabilization can occur independently of the E2F-regulated MDM2 inhibitor p14ARF Here, we report that the damage-induced noncoding (DINO) lncRNA (DINOL) is the "missing link" between HPV16 E7 and increased TP53 levels. DINO levels are decreased in cells where TP53 is inactivated, either by HPV16 E6, by expression of a dominant negative TP53 minigene, or by TP53 depletion. DINO levels are increased in HPV16 E7-expressing cells. HPV16 E7 causes increased DINO expression independently of RB1 degradation and E2F1 activation. Similar to what is seen with the adjacent CDKN1A locus, DINO expression is regulated by the histone demethylase KDM6A. DINO stabilizes TP53 in HPV16 E7-expressing cells, and as it is a TP53 transcriptional target, DINO levels further increase. As with expression of other oncogenes, such as adenovirus E1A or MYC, HPV16 E7-expressing cells are sensitized to cell death under conditions of metabolic stress, which in the case of E7 has been linked to TP53 activation. Consistent with earlier studies, we show that HPV16 E7-expressing keratinocytes are highly sensitive to metabolic stress induced by starvation or the antidiabetic drug metformin. Sensitivity of HPV16 E7-expressing cells to metabolic stress is rescued by DINO depletion. Moreover, DINO depletion decreases sensitivity to the DNA damage-inducing chemotherapy agent doxorubicin. This work identifies DINO as a critical mediator of TP53 stabilization and activation in HPV16 E7-expressing cells.IMPORTANCE Viral oncoproteins, including HPV16 E6 and E7, have been instrumental in elucidating the activities of cellular signaling networks, including those governed by the TP53 tumor suppressor. Our study demonstrates that the long noncoding RNA DINO is the long-sought missing link between HPV16 E7 and elevated TP53 levels. Importantly, the TP53-stabilizing DINO plays a critical role in the cell death response of HPV16 E7-expressing cells to metabolic stress or DNA damage.
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PMID:KDM6A-Mediated Expression of the Long Noncoding RNA DINO Causes TP53 Tumor Suppressor Stabilization in Human Papillomavirus 16 E7-Expressing Cells. 3226 26