New Chemotherapeutic Agents: Monoterpenes and Fatty Acid Synthase Inhibitors

Hyperglycaemia confers resistance to chemotherapy on breast cancer cells: the role of fatty acid synthase

Endocrine Related Cancer ◽

10.1677/erc-09-0221 ◽

2010 ◽

Vol 17 (2) ◽

pp. 539-551 ◽

Cited By ~ 71

Author(s):

L Zeng ◽

K M Biernacka ◽

J M P Holly ◽

C Jarrett ◽

A A Morrison ◽

...

Keyword(s):

Breast Cancer ◽

Fatty Acids ◽

Cell Death ◽

Fatty Acid ◽

Fatty Acid Synthase ◽

Cell Types ◽

Chemotherapeutic Agents ◽

Malignant Cells ◽

Obesity And Diabetes ◽

Ceramide Production

The prognosis for women with breast cancer is adversely affected by the comorbidities of obesity and diabetes mellitus (DM), which are conditions associated with elevated levels of circulating fatty acids, hyperglycaemia and hyperinsulinaemia. We investigated the effects of exposure of non-malignant and malignant human breast epithelial cells to elevated levels of fatty acids and glucose on their growth, survival and response to chemotherapeutic agents. We found that palmitate induced cell death in the non-malignant cells but not in the malignant cells, which was abrogated through the inhibition of ceramide production and by oleate but not by IGF1. Fatty acid synthase (FAS) is responsible for the de novo synthesis of fatty acids from sugars, and is over-expressed in many epithelial cancers. Abundance of FAS was higher in malignant cells than in non-malignant cells, and was up-regulated by IGF1 in both cell types. IGF-induced growth of non-malignant cells was unaffected by suppression of FAS expression, whereas that of malignant cells was blocked as was their resistance to palmitate-induced cell death. Palmitate did not affect cell proliferation, whereas oleate promoted the growth of non-malignant cells but had the opposite effect, that is, inhibition of IGF1-induced growth of malignant cells. However, when the phosphatidylinositol 3-kinase pathway was inhibited, oleate enhanced IGF1-induced growth in both cell types. Hyperglycaemia conferred resistance on malignant cells, but not on non-malignant cells, to chemotherapy-induced cell death. This resistance was overcome by inhibiting FAS or ceramide production. Understanding the mechanisms involved in the associations between obesity, DM and breast cancer may lead to more effective treatment regimens and new therapeutic targets.

Download Full-text

Prostatic Acid Phosphatase (PAP) Differentiated Ultracytochemically from Lysosomal Acid Phosphate in the Rat with a PAP/Specific Substrate, Phosphorylcholine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100115870 ◽

1975 ◽

Vol 33 ◽

pp. 450-451

Author(s):

W. Allen Shannon ◽

José A. Serrano ◽

Hannah L. Wasserkrug ◽

Anna A. Serrano ◽

Arnold M. Seligman

Keyword(s):

Acid Phosphatase ◽

Phosphate Buffer ◽

Prostatic Carcinoma ◽

Prostatic Acid Phosphatase ◽

Chemotherapeutic Agents ◽

Specific Substrate ◽

Acid Phosphate ◽

Lysosomal Acid ◽

Design And Synthesis ◽

New Chemotherapeutic Agents

During the design and synthesis of new chemotherapeutic agents for prostatic carcinoma based on phosphorylated agents which might be enzyme-activated to cytotoxicity, phosphorylcholine, [(CH3)3+NCH2CH2OPO3Ca]Cl-, has been indicated to be a very specific substrate for prostatic acid phosphatase (PAP). This phenomenon has led to the development of specific histochemical and ultracytochemical methods for PAP using modifications of the Gomori lead method for acid phosphatase. Comparative histochemical results in prostate and kidney of the rat have been published earlier with phosphorylcholine (PC) and β-glycerophosphate (βGP). We now report the ultracytochemical results.Minced tissues were fixed in 3% glutaraldehyde-0.1 M phosphate buffered (pH 7.4) for 1.5 hr and rinsed overnight in several changes of 0.05 M phosphate buffer (pH 7.0) containing 7.5% sucrose. Tissues were incubated 30 min to 2 hr in Gomori acid phosphatase medium (2) containing 0.1 M substrate, either PC or βGP.

Download Full-text