scholarly journals Repurposing Combination Therapy of Voacamine With Vincristine for Downregulation of Hypoxia-Inducible Factor-1α/Fatty Acid Synthase Co-axis and Prolyl Hydroxylase-2 Activation in ER+ Mammary Neoplasia

Author(s):  
Lakhveer Singh ◽  
Subhadeep Roy ◽  
Anurag Kumar ◽  
Shubham Rastogi ◽  
Dinesh Kumar ◽  
...  

Graphical AbstractMechanism of VOA and VIN to inhibit fatty acid synthesis in DMBA-induced mammary gland carcinoma of albino Wistar rats. Hypoxia-activated HIF-1α enhances lactate acidosis in the tumor microenvironment, and dysregulated pH in the tumor microenvironment activates SREBP-1c and FASN expression to speed up the fatty acid synthesis required for plasma membrane synthesis in rapidly proliferating cells. VOA- and VIN-activated PHD-2 enhanced the proteolytic degradation of HIF, thus inhibiting fatty acid synthesis. HIF-1α, hypoxia-inducible factor-1α; SREBP-1c, sterol regulatory element-binding protein-1c; FASN, fatty acid synthesis; PHD-2, prolyl hydroxylase-2.

2020 ◽  
Author(s):  
Lakhveer Singh ◽  
Manjari Singh ◽  
Dinesh Kumar ◽  
Mohd. Nazam Ansari ◽  
Abdulaziz S. Saeedan ◽  
...  

Abstract Background The current study was attempted to inquest the role of combination therapy of Voacamine and Vincristine for the prevention of mammary gland carcinoma through prolyl hydroxylase-2 activation. The prolyl hydroxylase‐2 activation leads the downregulation of hypoxia‐inducible factor‐1α and fatty acid synthase. Over expression of hypoxia inducible factor-1α and fatty acid synthase is previously reported in solid tumor of mammary gland. Methods After screening a battery of natural compounds which were similar to vincristine, vocamine was selected as a possible prolyl hydroxylase-2 activator and justify its activity using 7, 12-Dimethylbenz[a]anthracene induced rat model. The combination therapy was evaluated for cardiac toxicity using hemodynamic profile. The angiogenic markers were evaluated using carmine staining. Monotherapy and combination therapy were also evaluated for liver and kidney toxicity through haematoxylin and eosin staining. The combination therapy also delineated the markers of oxidative stress favorably. Afterwards, the disruption of fatty acids was evaluated using gas chromatography. Results The immunoblotting analysis validated that combination therapy has a potential to switch on the prolyl hydroxylase-2 activity and thus initiate proteolytic degradation of hypoxia‐inducible factor‐1α and its consequence effects. The combination therapy also stimulated programmed cell death (apoptosis) in rapidly dividing cancer cells. Conclusion The present study explores the role of voacamine in activation of prolyl hydroxylase-2 which can decrease over expression of hypoxia‐inducible factor‐1α and fatty acid synthase in cells of mammary gland carcinoma.


2020 ◽  
Author(s):  
Lakhveer Singh ◽  
Manjari Singh ◽  
Mohd. Nazam Ansari ◽  
Abdulaziz S. Saeedan ◽  
Gaurav Kaithwas

Abstract Background: The current study was attempted to inquest the role of combination therapy of Voacamine and Vincristine for the prevention of mammary gland carcinoma through prolyl hydroxylase‐2 activation. The prolyl hydroxylase‐2 activation leads the downregulation of hypoxia‐inducible factor‐1α and fatty acid synthase. Over expression of hypoxia inducible factor-1α and fatty acid synthase is previously reported in solid tumor of mammary gland. Methods: After screening a battery of natural compounds which were similar to vincristine, vocamine was selected as a possible prolyl hydroxylase‐2 activator and justify its activity using 7, 12-Dimethylbenz[a]anthracene induced rat model. The combination therapy was evaluated for cardiac toxicity using hemodynamic profile. The angiogenic markers were evaluated using carmine staining. Monotherapy and combination therapy were also evaluated for liver and kidney toxicity through haematoxylin and eosin staining. The combination therapy also delineated the markers of oxidative stress favorably. Afterwards, the disruption of fatty acids was evaluated using gas chromatography. Results: The immunoblotting analysis validated that combination therapy has a potential to switch on the prolyl hydroxylase‐2 activity and thus initiate proteolytic degradation of hypoxia‐inducible factor‐1α and its consequence effects. The combination therapy also stimulated programmed cell death (apoptosis) in rapidly dividing cancer cells.Conclusion: The present study explores the role of voacamine in activation of prolyl hydroxylase‐2 which can decrease over expression of hypoxia‐inducible factor‐1α and fatty acid synthase in cells of mammary gland carcinoma.


RSC Advances ◽  
2018 ◽  
Vol 8 (23) ◽  
pp. 12848-12860 ◽  
Author(s):  
Manjari Singh ◽  
Uma Devi ◽  
Subhadeep Roy ◽  
Pushpraj S. Gupta ◽  
Gaurav Kaithwas

(4-[7-(Acetyloxy)-2-ethyl-2H-chromen-3-yl] phenyl acetate) (BBAP-1) was identified as a potential prolyl hydroxylase-2 activator and tested for this activity using the 2-oxoglutarate dependentin vitroassay.


2000 ◽  
Vol 3 (6) ◽  
pp. 525-531 ◽  
Author(s):  
Robb E. Wilentz ◽  
Lee A. Witters ◽  
Ellen S. Pizer

Endogenous fatty acid synthesis has been observed in some rapidly proliferating cells and tissues, both normal and neoplastic, and probably supports membrane synthesis. Sterol regulatory element binding proteins (SREBPs) are transcription factors that regulate the expression of genes for both cholesterol and fatty acid synthesis. The inactive precursor form resides in cytoplasmic membranes. Intracellular lipid depletion triggers proteolytic cleavage of SREBP, allowing the amino terminus to enter the nucleus and activate the expression of enzymes, including acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), major biosynthetic enzymes for fatty acid synthesis. The expression patterns of ACC, FAS, SREBP, and Ki-67 in fetal tissues were compared to determine whether SREBP is likely to participate in the regulation of proliferation-associated fatty acid synthesis during fetal growth. Tissues from 22 fetuses, 12 first-trimester and 10 second-trimester (range 7.0 to 21.6 weeks), were studied. Serial 5-μm sections were stained with antibodies to ACC, FAS, SREBP, and Ki-67 and were compared. ACC, FAS, SREBP, and Ki-67 were coexpressed in the proliferative compartments of the intestines, skin, and kidney. ACC, FAS, and Ki-67 were coexpressed with little SREBP in lung and cytotrophoblast. SREBP, ACC, and FAS were coexpressed without Ki-67 in hepatocytes, ganglion cells, and intermediate trophoblast. The close linkage of SREBP, ACC, FAS, and Ki-67 in some proliferating fetal tissues suggests that in these tissues SREBP participates in the transcriptional regulation of lipogenic genes during proliferation. SREBP, ACC, and FAS coexpression without Ki-67 occurs in differentiated tissues that may synthesize fatty acids for other functions.


2000 ◽  
Vol 28 (6) ◽  
pp. 567-574 ◽  
Author(s):  
J. Ohlrogge ◽  
M. Pollard ◽  
X. Bao ◽  
M. Focke ◽  
T. Girke ◽  
...  

For over 25 years there has been uncertainty over the pathway from CO2, to acetyl-CoA in chloroplasts. On the one hand, free acetate is the most effective substrate for fatty acid synthesis by isolated chloroplasts, and free acetate concentrations reported in leaf tissue (0.1–1 mM) appear adequate to saturate fatty acid synthase. On the other hand, a clear mechanism to generate sufficient free acetate for fatty acid synthesis is not established and direct production of acetyl-CoA from pyruvate by a plastid pyruvate dehydrogenase seems a more simple and direct path. We have re-examined this question and attempted to distinguish between the alternatives. The kinetics of 13CO2 and 14CO2 movement into fatty acids and the absolute rate of fatty acid synthesis in leaves was determined in light and dark. Because administered 14C appears in fatty acids within < 2–3 min our results are inconsistent with a large pool of free acetate as an intermediate in leaf fatty acid synthesis. In addition, these studies provide an estimate of the turnover rate of fatty acid in leaves. Studies similar to the above are more complex in seeds, and some questions about the regulation of plant lipid metabolism seem difficult to solve using conventional biochemical or molecular approaches. For example, we have little understanding of why or how some seeds produce >50%, oil whereas other seeds store largely carbohydrate or protein. Major control over complex plant biochemical pathways may only become possible by understanding regulatory networks which provide ‘global’ control over these pathways. To begin to discover such networks and provide a broad analysis of gene expression in developing oilseeds, we have produced micro-arrays that display approx. 5000 seed-expressed Arabidopsis genes. Sensitivity of the arrays was 1–2 copies of mRNA/cell. The arrays have been hybridized with probes derived from seeds, leaves and roots, and analysis of expression ratios between the different tissues has allowed the tissue-specific expression patterns of many hundreds of genes to be described for the first time. Approx. 10% of the genes were expressed at ratios ≥ 10-fold higher in seeds than in leaves or roots. Included in this list are a large number of proteins of unknown function, and potential regulatory factors such as protein kinases, phosphatases and transcription factors. The arrays were also found to be useful for analysis of Brassica seeds.


2010 ◽  
Vol 299 (6) ◽  
pp. E918-E927 ◽  
Author(s):  
Michael C. Rudolph ◽  
Jenifer Monks ◽  
Valerie Burns ◽  
Meridee Phistry ◽  
Russell Marians ◽  
...  

The lactating mammary gland synthesizes large amounts of triglyceride from fatty acids derived from the blood and from de novo lipogenesis. The latter is significantly increased at parturition and decreased when additional dietary fatty acids become available. To begin to understand the molecular regulation of de novo lipogenesis, we tested the hypothesis that the transcription factor sterol regulatory element binding factor (SREBF)-1c is a primary regulator of this system. Expression of Srebf1c mRNA and six of its known target genes increased ≥2.5-fold at parturition. However, Srebf1c-null mice showed only minor deficiencies in lipid synthesis during lactation, possibly due to compensation by Srebf1a expression. To abrogate the function of both isoforms of Srebf1, we bred mice to obtain a mammary epithelial cell-specific deletion of SREBF cleavage-activating protein (SCAP), the SREBF escort protein. These dams showed a significant lactation deficiency, and expression of mRNA for fatty acid synthase ( Fasn), insulin-induced gene 1 ( Insig1), mitochondrial citrate transporter ( Slc25a1), and stearoyl-CoA desaturase 2 ( Scd2) was reduced threefold or more; however, the mRNA levels of acetyl-CoA carboxylase-1α ( Acaca) and ATP citrate lyase ( Acly) were unchanged. Furthermore, a 46% fat diet significantly decreased de novo fatty acid synthesis and reduced the protein levels of ACACA, ACLY, and FASN significantly, with no change in their mRNA levels. These data lead us to conclude that two modes of regulation exist to control fatty acid synthesis in the mammary gland of the lactating mouse: the well-known SREBF1 system and a novel mechanism that acts at the posttranscriptional level in the presence of SCAP deletion and high-fat feeding to alter enzyme protein.


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