ABSTRACT
<p><b>OBJECTIVE</b>To study the effects of different dietary fatty acid on the expression of nuclear receptor genes in the breast cancer of rats.</p><p><b>METHODS</b>Fifty-day-old female Sprague-Dawley rats were fed on eight different diets containing following fatty acids: saturated fatty acid (SFA); monounsaturated fatty acid (MUFA); n-6 polyunsaturated fatty acid (PUFA); n-3 PUFA; 1:1 n-6/n-3; 5:1 n-6/n-3; 10:1 n-6/n-3; 1:2:1 S/M/P (n-6/n-3 at 1:1). The rats were given a single intraperitoneal injection of methyl-nitrosourea (MNU) at 50 mg/kg body weight to establish the rat model of mammary carcinogenesis, the ultrastructure changes of mammary gland cells in rats were observed by transmission electron microscope, the cell proliferation activity was detected by BrdU-labeled immunocytochemistry, and the expression of PPARbeta and PPARgamma mRNA were assayed by RT-PCR.</p><p><b>RESULTS</b>There was no breast cancer occurring in control groups and the MNU-treated n-3 PUFA group, and the ultrastructure and proliferation activity of mammary gland cells in these groups were normal. In contrast, there appeared obvious marker of adenocarcinomas in mammary gland cells of MNU-induced breast cancer, and a high cell proliferation activity was found in tumor growth-enhancing groups (SFA, MUFA, n-6 PUFA, 5:1 n-6/n-3, 10:1 n-6/n-3 and S/M/P, 21% - 22% of BrdU-labeled cells), while a low cell proliferation activity was detected in rats fed with 1:1 n-6/n-3 diet (13% of BrdU-labeled cells, P < 0.05). Moreover, peroxisome proliferator-activated receptors (PPARs), as important nuclear receptor genes of relating lipid metabolism, the expressions of PPARbeta and PPARgamma mRNA were significantly up-regulated in mammary adipose tissues of MNU-induced breast cancer as compared with the control groups, but the expression levels of peroxisome proliferator-activated receptors (PPARs) in rats fed with 1:1 n-6/n-3 group were lowest (P < 0.05).</p><p><b>CONCLUSION</b>The different dietary fatty acid compositions should diversely adjust the expression of PPARs gene in rats, which maybe have an important role in affecting incidence of breast cancer.</p>
Subject(s)
Animals , Female , Rats , Fatty Acids , Pharmacology , Fatty Acids, Omega-3 , Pharmacology , Fatty Acids, Omega-6 , Pharmacology , Fatty Acids, Unsaturated , Pharmacology , Gene Expression , Gene Expression Regulation, Neoplastic , Mammary Neoplasms, Experimental , Genetics , PPAR gamma , Genetics , RNA, Messenger , Genetics , Rats, Sprague-DawleyABSTRACT
Objective To investigate the expression of TGF-β and TGF-β receptor in human breast cancer cell Bcap-37 inhibited by soybean isoflavones. Methods mRNA and protein of TGF-β1、TGF-βRⅠ in Bcap-37 cells were examined with reverse transcription ploymerase chain reaction(RT-PCR) and immunohistochemistry after cells were treated with daidein or genistein for 1-4 d.The expression of TGF-β1 and TGF-β2 was determined with TGF-β resistance test. Results The TGF-β1, TGF-β2 and TGF-β recepor increased in Bcap-37 cells at a concentration of 3×10-5 mol/L of genistein. No changes was found when treated with daidzein. Conclusion Genistein may inhibit the proliferation of Bcap-37 cells and accompany with increasing expression of TGF-β1, TGF-β2 and TGF-β receptor.
ABSTRACT
Objective To study the effect of glucagon-like peptide 2 (GLP-2) on mitogen-activated protein kinase (MAPK) activity in small intestinal epithelia in mice after radiation injury and its relation with the change of small intestinal epithelial proliferation. Methods Mice were given a single dose of 8 Gy of total body 60Co gamma irradiation and then divided into GLP-2 and control groups. The activity of MAPK and proliferation rate in small intestinal epithelia were measured. Results The activity of MAPK in small intestinal epithelia was higher in GLP-2-treated mice than in irradiated mice, and the proliferation rate in small intestinal epithelia significantly increased in GLP-2-treated mice. These two indices were of significantly positive correlated. Conclusion GLP-2 can promote small intestinal epithelial proliferation in irradiated mice, and this may be related to activation of MAPK in small intestinal epithelia.
ABSTRACT
Objective To investigate the effects of glucagon-like peptide 2 (GLP-2) on recovery of small intestinal epithelia from radiation injury in mice. Methods Mice received a single 8 Gy dose of total body irradiation from 60Co gamma ray followed by treatment with GLP-2 or vehicle. DNA and protein content in small intestinal mucosa were measured, and small intestine was processed for histological examination with light microscope and scanning electron microscope. Results Small intestinal mucosal DNA and protein content, villus height, and villus number significantly decreased in irradiated mice, partial villus tips were ulcerated. GLP-2 administration caused increase in DNA and protein content, villus height, and villus number as compared with irradiated control group. Meanwhile, the villus tips were lack of ulceration. Conclusion GLP-2 can promote recovery of small intestinal epithelia from radiation injury in mice.
ABSTRACT
Objective To investigate the expression of TGF-β and TGF-β receptor in human breast cancer cell Bcap-37 inhibited by soybean isoflavones. Methods mRNA and protein of TGF-β1、TGF-βRⅠ in Bcap-37 cells were examined with reverse transcription ploymerase chain reaction(RT-PCR) and immunohistochemistry after cells were treated with daidein or genistein for 1-4 d.The expression of TGF-β1 and TGF-β2 was determined with TGF-β resistance test. Results The TGF-β1, TGF-β2 and TGF-β recepor increased in Bcap-37 cells at a concentration of 3×10-5 mol/L of genistein. No changes was found when treated with daidzein. Conclusion Genistein may inhibit the proliferation of Bcap-37 cells and accompany with increasing expression of TGF-β1, TGF-β2 and TGF-β receptor.
ABSTRACT
Objective To study the effect of glucagon-like peptide 2 (GLP-2) on mitogen-activated protein kinase (MAPK) activity in small intestinal epithelia in mice after radiation injury and its relation with the change of small intestinal epithelial proliferation. Methods Mice were given a single dose of 8 Gy of total body 60Co gamma irradiation and then divided into GLP-2 and control groups. The activity of MAPK and proliferation rate in small intestinal epithelia were measured. Results The activity of MAPK in small intestinal epithelia was higher in GLP-2-treated mice than in irradiated mice, and the proliferation rate in small intestinal epithelia significantly increased in GLP-2-treated mice. These two indices were of significantly positive correlated. Conclusion GLP-2 can promote small intestinal epithelial proliferation in irradiated mice, and this may be related to activation of MAPK in small intestinal epithelia.
ABSTRACT
Objective To investigate the effects of glucagon-like peptide 2 (GLP-2) on recovery of small intestinal epithelia from radiation injury in mice. Methods Mice received a single 8 Gy dose of total body irradiation from 60Co gamma ray followed by treatment with GLP-2 or vehicle. DNA and protein content in small intestinal mucosa were measured, and small intestine was processed for histological examination with light microscope and scanning electron microscope. Results Small intestinal mucosal DNA and protein content, villus height, and villus number significantly decreased in irradiated mice, partial villus tips were ulcerated. GLP-2 administration caused increase in DNA and protein content, villus height, and villus number as compared with irradiated control group. Meanwhile, the villus tips were lack of ulceration. Conclusion GLP-2 can promote recovery of small intestinal epithelia from radiation injury in mice.