Wyniki wyszukiwania

1

Effects of cadmium on the testicular structure and the level of retinoids and beta-carotene in testis in mice after an experimental administration

100%

Massanyi P., Bardos L., Toman R.

Polish Journal of Natural Sciences

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2002

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tom 10

2

Celecoxib increases retinoid sensitivity in human colon cancer cell lines

84%

Liu J. P., Wei H.-B., Zheng Z.-H., Guo W.-P., Fang J.-F.

Cellular and Molecular Biology Letters

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2010

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tom 15

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nr 3

440-450

Retinoid resistance has limited the clinical application of retinoids as differentiation-inducing and apoptosis-inducing drugs. This study was designed to investigate whether celecoxib, a selective COX-2 inhibitor, has effects on retinoid sensitivity in human colon cancer cell lines, and to determine the possible mechanism of said effects. Cell viability was measured using the MTT assay. Apoptosis was detected via Annexin-V/PI staining and the flow cytometry assay. PGE2 production was measured with the ELISA assay. The expression of RARβ was assayed via western blotting. The results showed that celecoxib enhanced the inhibitory effect of ATRA in both COX-2 high-expressing HT-29 and COX-2 low-expressing SW480 cell lines. Further study showed the ATRA and celecoxib combination induced greater apoptosis, but that the addition of PGE2 did not affect the enhanced growth-inhibitory and apoptosis-inducing effects of the combination. Moreover, NS398 (another selective COX-2 inhibitor) did not affect the inhibitory effects of ATRA in the two cell lines. Western blotting showed that the expression of RARβ in HT-29 cell lines was increased by celecoxib, but not by NS398, and that the addition of PGE2 did not affect the celecoxib-induced expression of the retinoic acid receptor beta. In conclusion, celecoxib increased the expression of RARβ and the level of cellular ATRA sensitivity through COX-2-independent mechanisms. This finding may provide a potential strategy for combination therapy.

3

Retinoids as an immunity-modulator in dermatology disorders

84%

Chen W., Zhao S., Zhu W., Wu L., Chen X.

Archivum Immunologiae et Therapiae Experimentalis

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2019

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tom 67

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nr 6

4

The effect of doxorubicin and retinoids on proliferation, necrosis and apoptosis in MCF-7 breast cancer cells

84%

Czeczuga-Semeniuk E., Wolczynski S., Dabrowska M., Dzieciol J., Anchim T.

Folia Histochemica et Cytobiologica

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2004

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tom 42

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nr 4

5

Can transforming growth factor-beta1 and retinoids modify the activity of estradiol and antiestrogens in MCF-7 breast cancer cells?

84%

Czeczuga-Semeniuk E., Anchim T., Dzieciol J., Dabrowska M., Wolczynski S.

Acta Biochimica Polonica

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2004

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tom 51

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nr 3

Retinoic acid and transforming growth factor-ß (TGF-ß) affect differentiation, proliferation and carcinogenesis of epithelial cells. The effect of both compounds on the proliferation of cells of the hormone sensitive human breast cancer cell line (ER+) MCF-7 was assessed in the presence of estradiol and tamoxifen. The assay was based on [ 3H] thymidine incorporation and the proliferative activity of PCNA- and Ki 67-positive cells. The apoptotic index and expression of the Bcl-2 and p53 antigens in MCF-7 cells were also determined. Exogenous TGF-ß1 added to the cell culture showed antiproliferative activity within the concentration range of 0.003-30 ng/ml. Irrespective of TGF-ß 1 concentrations, a marked reduction in the stimulatory action of estradiol (10-9 and 10-8 M) was observed whereas in combination with tamoxifen (10 -7 and 10 -6 M) only 30 ng/ml TGF-ß 1 caused a statistically significant reduction to aproximately 30% of the proliferative cells. In further experiments we examined the effect of exposure of breast cancer cells to retinoids in combination with TGF-ß 1. The incorporation of [3H]thymidine into MCF-7 cells was inhibited to 52 ± 19% (control = 100%) by 3 ng/ml TGF-ß1, and this dose was used throughout. It was found that addition of TGF-ß1 and isotretinoin to the culture did not decrease proliferation, while TGF-ß1 and tretinoin at low concentrations (3 x 10 -8 and 3 x 10-7 M) reduced the percentage of proliferating cells by aproximately 30% (67±8% and 67±5%, P < 0.05 compared to values in the tretinoin group). Both retinoids also led to a statistically significant decrease in the stimulatory effect of 10-9 M estradiol, attenuated by TGF-ß1. In addition, the retinoids in combination with TGF-ß1 and tamoxifen (10–6 M) caused a further reduction in the percentage of proliferating cells. Immunocytochemical analysis showed that all the examined compounds gave a statistically significant reduction in the percentage of cells with a positive reaction to PCNA and Ki 67 antigen. TGF-ß1, isotretinoin and tretinoin added to the culture resulted in the lowest percentage of PCNA positive cells. However, the lowest fraction of Ki 67 positive cells was observed after addition of isotretinoin. The obtained results also confirm the fact that the well-known regulatory proteins Bcl-2 and p53 play an important role in the regulation of apoptosis in the MCF-7 cell line, with lowered Bcl-2 expression accompanying easier apoptotic induction. The majority of the examined compounds act via the p53 pathway although some bypass this important proapoptotic factor.

6

Can vitamin A modify the activity of docetaxel in MCF-7 breast cancer cells?

67%

Czeczuga-Semeniuk E., Lemancewicz D., Wolczynski S.

Folia Histochemica et Cytobiologica. Supplement

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2007

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tom 45

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nr 1

169-174

7

Influence of retinoids on the lysosomal system in mouse liver

67%

Krol T.

Acta Biologica Cracoviensia. Series Zoologia

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2000

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tom 42

8

Molecular mechanisms of retinoid action

67%

Gronemeyer H., Miturski R.

Cellular and Molecular Biology Letters

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2001

|

tom 06

|

nr 1

9

Biological role of liver X receptors

59%

Baranowski M.

Journal of Physiology and Pharmacology. Supplement

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2008

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tom 59

|

nr 7

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