Membrane 5α-pregnane-3,20-dione (5αP) receptors in MCF-7 and MCF-10A breast cancer cells are up-regulated by estradiol and 5αP and down-regulated by the progesterone metabolites, 3α-dihydroprogesterone and 20α-dihydroprogesterone, with associated changes in cell proliferation and detachment

Pawlak, Kevin J.; Zhang, G.; Wiebe, John P.

doi:10.1016/j.jsbmb.2005.05.014

Cited by 27 publications

(35 citation statements)

References 52 publications

(72 reference statements)

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“…Lack of inhibition of the response by cycloheximide supports a mechanism not dependent upon protein synthesis. The dose of cycloheximide used in this study was previously shown to inhibit protein synthesis in MCF-10A cells (36). We corroborated this finding by demonstrating inhibition of TGF-␤ 1 -induced expression of Id-1, a known transcriptional induction in MCF-10A cells (28).…”

Section: Discussionsupporting

confidence: 86%

Progesterone stimulates mitochondrial activity with subsequent inhibition of apoptosis in MCF-10A benign breast epithelial cells

Behera

Dai

Garde

et al. 2009

American Journal of Physiology-Endocrinology and Metabolism

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As an example, progesterone levels correlate with increased epithelial cell proliferation, but there is discordance between the dividing cells and the cells with nuclear progesterone receptor expression. The release of paracrine growth factors from nuclear receptor-positive cells has been postulated as a mechanism, since in vitro studies show a lack of growth effect by progesterone in breast epithelial cells lacking nuclear receptors. This study examined possible nongenomic effects of progesterone in breast epithelia by using MCF-10A cells known to lack nuclear progesterone receptor expression. Treatment for 30 -60 min with progesterone or the progestin, R5020, increased mitochondrial activity as shown by an increase in mitochondrial membrane potential (hyperpolarization) with a concordant increase in total cellular ATP. The reaction was inhibited by a specific progesterone receptor antagonist and not affected by the translation inhibitor cycloheximide. Progestin treatment inhibited apoptosis induced by activation of the FasL pathway, as shown by a decrease in sub-G 1 cell fraction during fluorescence-activated cell sorting and a decrease in caspase 3/7 levels. Progestin treatment did not alter the cell cycle over 48 h. Our study demonstrates a nongenomic action of progesterone on benign breast epithelial cells, resulting in enhanced cellular respiration and protection from apoptosis.progesterone; MCF-10A cells; mitochondria; apoptosis; cellular respiration PREVIOUS STUDIES HAVE SHOWN a discordance between the proliferative action of progesterone in the breast and the content of nuclear progesterone receptors (PR-B and PR-A) in breast epithelial cells. As examples, the mitotic rate of breast epithelial cells is greatest in the progesterone-dominant luteal phase (44). Exogenous administration of estrogen plus progestin results in greater breast epithelial proliferation than estrogen alone (15, 18). The progesterone receptor knockout (PRKO) mouse, an excellent model for the function of nuclear PR in mammary gland development, supports a proliferative role. PR-B is primarily responsible for gland development, with PRKO-B mice showing less extensive ductal development and lack of alveolar terminal end buds (7,29). In contrast to these physiological effects, very few breast epithelial cells appear to express nuclear PR. In immunocytochemical studies of human breast tissue, from 6 to 13% of ductal epithelial cells express PR (6, 37), with the two PR isoforms, B and A, typically localizing in the same cell (14). Immunocytochemical analysis of proliferation by detection of Ki67 antigen in human breast or autoradiographs of [ 3 H]thymidine incorporation in rodent mammary samples show nuclear PR-expressing cells to be nonproliferating. Adjacent cells lacking nuclear PR expression have greater mitotic activity (23). This disassociation between nuclear PR expression and proliferation led to the hypothesis that nuclear PR-expressing cells regulate proliferation of adjacent cells via the control of paracrine factors (4).This ...

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Section: Discussionsupporting

confidence: 86%

Progesterone stimulates mitochondrial activity with subsequent inhibition of apoptosis in MCF-10A benign breast epithelial cells

Behera

Dai

Garde

et al. 2009

American Journal of Physiology-Endocrinology and Metabolism

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“…6, A and D). Western blots showed that the total intact P-gp-EGFP protein level was considerably decreased (ϳ42%) after incubation with CHX (10 g/ml, 24 h), a concentration used previously under similar conditions (8,27,28,31), indicating that synthesis of P-gp-EGFP was indeed inhibited (data not shown). In addition, the percentage of P-gp-EGFP localized on the plasma membrane was notably decreased after treatment of CHX (Fig.…”

Section: Accumulation Of P-gp-egfp In Early Endosome After Disruptionsupporting

confidence: 53%

“…The pathway for traffic of P-gp-EGFP was also studied with the use of CHX to inhibit new protein synthesis (8,18,27,31). P-gp-EGFP was observed to have intracellular localization after MCF-7/P-gp-EGFP cells were incubated with 10 g/ml CHX for 24 h (Fig.…”

Section: Accumulation Of P-gp-egfp In Early Endosome After Disruptionmentioning

confidence: 99%

Actin disruption inhibits endosomal traffic of P-glycoprotein-EGFP and resistance to daunorubicin accumulation

Roufogalis²

2007

American Journal of Physiology-Cell Physiology

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traffic of human P-glycoprotein (P-gp), a membrane transporter responsible for multidrug resistance in cancer chemotherapy, was investigated using a P-gp and enhanced green fluorescent fusion protein (P-gp-EGFP) in human breast cancer MCF-7 cells. The stably expressed P-gp-EGFP from a clonal cell population was functional as a drug efflux pump, as demonstrated by the inhibition of daunorubicin accumulation and the conferring of resistance of the cells to colchicine and daunorubicin. Colocalization experiments demonstrated that a small fraction of the total P-gp-EGFP expressed was localized intracellularly and was present in early endosome and lysosome compartments. P-gp-EGFP traffic was shown to occur via early endosome transport to the plasma membrane. Subsequent movement of P-gp-EGFP away from the plasma membrane occurred by endocytosis to the early endosome and lysosome. The component of the cytoskeleton responsible for P-gp-EGFP traffic was demonstrated to be actin rather than microtubules. In functional studies it was shown that in parallel with the interruption of the traffic of P-gp-EGFP, cellular accumulation of the P-gp substrate daunorubicin was increased after cells were treated with actin inhibitors, and cell proliferation was inhibited to a greater extent than in the presence of daunorubicin alone. The actin dependence of P-gp traffic and the parallel changes in cytotoxic drug accumulation demonstrated in this study delineates the pathways of P-gp traffic and may provide a new approach to overcoming multidrug resistance in cancer chemotherapy. protein traffic; drug resistance in cancer; daunorubicin

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“…5␣-Pregnanes (e.g., 5␣P) increase breast cancer cell proliferation and detachment while 4-pregnenes (e.g., 3␣HP and 20␣HP) decrease breast cancer cell proliferation and detachment [23]. Progesterone metabolites and E2 have also been shown to affect 5␣P receptor levels [25,26] and these changes were correlated with changes in proliferation and adhesion [26]. The findings that progesterone metabolites and E2 can both influence proliferation in ER positive mammary cells and interact with each other to regulate 5␣P-R numbers, led us to investigate the role of the progesterone metabolites, 5␣P, 3␣HP and 20␣HP on ER levels in MCF-7 cells.…”

Section: Introductionmentioning

confidence: 99%

Regulation of estrogen receptor (ER) levels in MCF-7 cells by progesterone metabolites

Pawlak

Wiebe

2007

The Journal of Steroid Biochemistry and Molecular Biology

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Membrane 5α-pregnane-3,20-dione (5αP) receptors in MCF-7 and MCF-10A breast cancer cells are up-regulated by estradiol and 5αP and down-regulated by the progesterone metabolites, 3α-dihydroprogesterone and 20α-dihydroprogesterone, with associated changes in cell proliferation and detachment

Cited by 27 publications

References 52 publications

Progesterone stimulates mitochondrial activity with subsequent inhibition of apoptosis in MCF-10A benign breast epithelial cells

Progesterone stimulates mitochondrial activity with subsequent inhibition of apoptosis in MCF-10A benign breast epithelial cells

Actin disruption inhibits endosomal traffic of P-glycoprotein-EGFP and resistance to daunorubicin accumulation

Regulation of estrogen receptor (ER) levels in MCF-7 cells by progesterone metabolites

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