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Oridonin induces apoptosis and senescence in colorectal cancer cells by increasing histone hyperacetylation and regulation of p16, p21, p27 and c-myc.

Gao FH, Hu XH, Li W, Liu H, Zhang YJ, Guo ZY, Xu MH, Wang ST, Jiang B, Liu F, Zhao YZ, Fang Y, Chen FY, Wu YL - BMC Cancer (2010)

Bottom Line: Senescent cells were determined by senescence-associated β-galactosidase activity analysis.Daily i.p. injection of oridonin (6.25, 12.5 or 25 mg/kg) for 28 days significantly inhibited the growth of SW1116 s.c. xenografts in BABL/C nude mice.With western blot and reverse transcription-PCR, we further showed that the antitumor activities of oridonin correlated with induction of histone (H3 and H4) hyperacetylation, activation of p21, p27 and p16, and suppression of c-myc expression.

View Article: PubMed Central - HTML - PubMed

Affiliation: NO 3 People's Hospital affiliated to Shanghai Jiao-Tong University School of Medicine, Shanghai 201900, PR China.

ABSTRACT

Background: Oridonin, a tetracycline diterpenoid compound, has the potential antitumor activities. Here, we evaluate the antitumor activity and action mechanisms of oridonin in colorectal cancer.

Methods: Effects of oridonin on cell proliferation were determined by using a CCK-8 Kit. Cell cycle distribution was determined by flow cytometry. Apoptosis was examined by analyzing subdiploid population and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Senescent cells were determined by senescence-associated β-galactosidase activity analysis. Semi-quantitative RT-PCR was used to examine the changes of mRNA of p16, p21, p27 and c-myc. The concomitant changes of protein expression were analyzed with Western blot. Expression of AcH3 and AcH4 were examined by immunofluorescence staining and Western blots. Effects of oridonin on colony formation of SW1116 were examined by Soft Agar assay. The in vivo efficacy of oridonin was detected using a xenograft colorectal cancer model in nude mice.

Results: Oridonin induced potent growth inhibition, cell cycle arrest, apoptosis, senescence and colony-forming inhibition in three colorectal cancer cell lines in a dose-dependent manner in vitro. Daily i.p. injection of oridonin (6.25, 12.5 or 25 mg/kg) for 28 days significantly inhibited the growth of SW1116 s.c. xenografts in BABL/C nude mice. With western blot and reverse transcription-PCR, we further showed that the antitumor activities of oridonin correlated with induction of histone (H3 and H4) hyperacetylation, activation of p21, p27 and p16, and suppression of c-myc expression.

Conclusion: Oridonin possesses potent in vitro and in vivo anti-colorectal cancer activities that correlated with induction of histone hyperacetylation and regulation of pathways critical for maintaining growth inhibition and cell cycle arrest. Therefore, oridonin may represent a novel therapeutic option in colorectal cancer treatment.

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Oridonin inhibits tumor growth in nude mice through induction apoptosis and senescence. The mice were administered intraperitoneally with 0.2 ml of PBS or DMSO (1% in PBS) or indicated dose of oridonin for 28 days, then the tumors were excised for pathological examination. (A). Tumor section from PBS or DMSO (1% in PBS) or oridonin treated mice were stained with hematoxylin-eosin (HE) (×200). (B). Apoptotic colorectal cells were assessed by fluorescent TUNEL assay (×100). (C). Senescent colorectal cells were examined by Senescence-associated-β-galactosidase (SA-β-Gal) staining (×200).
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Figure 7: Oridonin inhibits tumor growth in nude mice through induction apoptosis and senescence. The mice were administered intraperitoneally with 0.2 ml of PBS or DMSO (1% in PBS) or indicated dose of oridonin for 28 days, then the tumors were excised for pathological examination. (A). Tumor section from PBS or DMSO (1% in PBS) or oridonin treated mice were stained with hematoxylin-eosin (HE) (×200). (B). Apoptotic colorectal cells were assessed by fluorescent TUNEL assay (×100). (C). Senescent colorectal cells were examined by Senescence-associated-β-galactosidase (SA-β-Gal) staining (×200).

Mentions: We next further assessed the in vivo anti-colorectal cancer effects of oridonin. BALB/C nude mice xenografts were treated with oridonin by daily i.p injection at 6.25 or 12.5 or 25 mg/kg for up to 28 days. Such treatment resulted in significant suppression of xenograft growth , compared with the PBS or DMSO (1% in PBS) treated group (P < 0.05; Figure 6B and 6C). In the low-dose (6.25 mg/kg) group, significant tumor growth inhibition effect was observed until 21 days, while in the middle dose (12.5 mg/kg) group, significant tumor growth inhibition effect was observed on day 14. More interesting, the high dose (25 mg/kg) administration almost completely inhibited tumor growth at the onset phase. It is worth noting that no obvious changes in body weight were observed in the oridonin treated groups, compared with the PBS or DMSO (1% in PBS) treated groups (Figure 6D). In H & E stained tumor section, sparse tumor cells and areas of necrosis foci can be seen in oridonin treated mice, while massive tumor cells were observed in PBS or DMSO (1% in PBS) treated mice (Figure 7A). TUNEL assay (Figure 7B) and Senescence-associated-β-galactosidase (SA-β-Gal) staining (Figure 7C) were also performed to detect the degree of apoptosis and senescence. The results showed that oridonin induces apoptosis and senescence of colorectal cells in vivo in a dose dependent manner.


Oridonin induces apoptosis and senescence in colorectal cancer cells by increasing histone hyperacetylation and regulation of p16, p21, p27 and c-myc.

Gao FH, Hu XH, Li W, Liu H, Zhang YJ, Guo ZY, Xu MH, Wang ST, Jiang B, Liu F, Zhao YZ, Fang Y, Chen FY, Wu YL - BMC Cancer (2010)

Oridonin inhibits tumor growth in nude mice through induction apoptosis and senescence. The mice were administered intraperitoneally with 0.2 ml of PBS or DMSO (1% in PBS) or indicated dose of oridonin for 28 days, then the tumors were excised for pathological examination. (A). Tumor section from PBS or DMSO (1% in PBS) or oridonin treated mice were stained with hematoxylin-eosin (HE) (×200). (B). Apoptotic colorectal cells were assessed by fluorescent TUNEL assay (×100). (C). Senescent colorectal cells were examined by Senescence-associated-β-galactosidase (SA-β-Gal) staining (×200).
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC2992521&req=5

Figure 7: Oridonin inhibits tumor growth in nude mice through induction apoptosis and senescence. The mice were administered intraperitoneally with 0.2 ml of PBS or DMSO (1% in PBS) or indicated dose of oridonin for 28 days, then the tumors were excised for pathological examination. (A). Tumor section from PBS or DMSO (1% in PBS) or oridonin treated mice were stained with hematoxylin-eosin (HE) (×200). (B). Apoptotic colorectal cells were assessed by fluorescent TUNEL assay (×100). (C). Senescent colorectal cells were examined by Senescence-associated-β-galactosidase (SA-β-Gal) staining (×200).
Mentions: We next further assessed the in vivo anti-colorectal cancer effects of oridonin. BALB/C nude mice xenografts were treated with oridonin by daily i.p injection at 6.25 or 12.5 or 25 mg/kg for up to 28 days. Such treatment resulted in significant suppression of xenograft growth , compared with the PBS or DMSO (1% in PBS) treated group (P < 0.05; Figure 6B and 6C). In the low-dose (6.25 mg/kg) group, significant tumor growth inhibition effect was observed until 21 days, while in the middle dose (12.5 mg/kg) group, significant tumor growth inhibition effect was observed on day 14. More interesting, the high dose (25 mg/kg) administration almost completely inhibited tumor growth at the onset phase. It is worth noting that no obvious changes in body weight were observed in the oridonin treated groups, compared with the PBS or DMSO (1% in PBS) treated groups (Figure 6D). In H & E stained tumor section, sparse tumor cells and areas of necrosis foci can be seen in oridonin treated mice, while massive tumor cells were observed in PBS or DMSO (1% in PBS) treated mice (Figure 7A). TUNEL assay (Figure 7B) and Senescence-associated-β-galactosidase (SA-β-Gal) staining (Figure 7C) were also performed to detect the degree of apoptosis and senescence. The results showed that oridonin induces apoptosis and senescence of colorectal cells in vivo in a dose dependent manner.

Bottom Line: Senescent cells were determined by senescence-associated β-galactosidase activity analysis.Daily i.p. injection of oridonin (6.25, 12.5 or 25 mg/kg) for 28 days significantly inhibited the growth of SW1116 s.c. xenografts in BABL/C nude mice.With western blot and reverse transcription-PCR, we further showed that the antitumor activities of oridonin correlated with induction of histone (H3 and H4) hyperacetylation, activation of p21, p27 and p16, and suppression of c-myc expression.

View Article: PubMed Central - HTML - PubMed

Affiliation: NO 3 People's Hospital affiliated to Shanghai Jiao-Tong University School of Medicine, Shanghai 201900, PR China.

ABSTRACT

Background: Oridonin, a tetracycline diterpenoid compound, has the potential antitumor activities. Here, we evaluate the antitumor activity and action mechanisms of oridonin in colorectal cancer.

Methods: Effects of oridonin on cell proliferation were determined by using a CCK-8 Kit. Cell cycle distribution was determined by flow cytometry. Apoptosis was examined by analyzing subdiploid population and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Senescent cells were determined by senescence-associated β-galactosidase activity analysis. Semi-quantitative RT-PCR was used to examine the changes of mRNA of p16, p21, p27 and c-myc. The concomitant changes of protein expression were analyzed with Western blot. Expression of AcH3 and AcH4 were examined by immunofluorescence staining and Western blots. Effects of oridonin on colony formation of SW1116 were examined by Soft Agar assay. The in vivo efficacy of oridonin was detected using a xenograft colorectal cancer model in nude mice.

Results: Oridonin induced potent growth inhibition, cell cycle arrest, apoptosis, senescence and colony-forming inhibition in three colorectal cancer cell lines in a dose-dependent manner in vitro. Daily i.p. injection of oridonin (6.25, 12.5 or 25 mg/kg) for 28 days significantly inhibited the growth of SW1116 s.c. xenografts in BABL/C nude mice. With western blot and reverse transcription-PCR, we further showed that the antitumor activities of oridonin correlated with induction of histone (H3 and H4) hyperacetylation, activation of p21, p27 and p16, and suppression of c-myc expression.

Conclusion: Oridonin possesses potent in vitro and in vivo anti-colorectal cancer activities that correlated with induction of histone hyperacetylation and regulation of pathways critical for maintaining growth inhibition and cell cycle arrest. Therefore, oridonin may represent a novel therapeutic option in colorectal cancer treatment.

Show MeSH
Related in: MedlinePlus