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Melatonin Attenuates Her-2, p38 MAPK, p-AKT, and mTOR Levels in Ovarian Carcinoma of Ethanol-Preferring Rats.

Ferreira GM, Martinez M, Camargo IC, Domeniconi RF, Martinez FE, Chuffa LG - J Cancer (2014)

Bottom Line: While Mel therapy was unable to reduce Her-4 and phosphoinositide 3-kinase (PI3K) levels, it was able to suppress the OC-related increase in the levels of the Her-2, p38 mitogen-activated protein kinases (p38 MAPK), protein kinase B (phospho-AKT), and mammalian target of rapamycin (mTOR).In addition, Mel significantly attenuated the expression of Her-2, p38 MAPK, and p-AKT, which are involved in OC signaling during ethanol intake.Collectively, our results suggest that Mel attenuates the Her-2-signaling pathway in OC of ethanol-preferring rats, providing an effective contribution for further development of adjuvant therapies.

View Article: PubMed Central - PubMed

Affiliation: 1. Department of Anatomy, Biosciences Institute, UNESP - Univ. Estadual Paulista, Botucatu-SP, Brazil, 18618-970.

ABSTRACT
Epidermal growth factor receptors 2 (Her-2) and 4 (Her-4) are closely associated with ovarian cancer (OC) progression and metastasis, and a more complete understanding of these signaling pathways allow the development of new therapeutic strategies. Melatonin (Mel) is recognized as having several anticancer properties and has been reported to modulate Her-2 system in aggressive tumors. Here, we investigated OC and the role of Mel therapy on the Her-2- and Her-4-signaling pathway related to downstream molecules in an ethanol-preferring rat model. To induce OC, the left ovary was injected directly with a single dose of 100 µg 7,12-dimethylbenz(a)anthracene (DMBA) dissolved in 10 µL of sesame oil under the bursa. Right ovaries were used as sham-surgery controls. After developing OC, half of the animals received i.p. injections of Mel (200 µg/100 g b.w./day) for 60 days. While Mel therapy was unable to reduce Her-4 and phosphoinositide 3-kinase (PI3K) levels, it was able to suppress the OC-related increase in the levels of the Her-2, p38 mitogen-activated protein kinases (p38 MAPK), protein kinase B (phospho-AKT), and mammalian target of rapamycin (mTOR). In addition, Mel significantly attenuated the expression of Her-2, p38 MAPK, and p-AKT, which are involved in OC signaling during ethanol intake. Collectively, our results suggest that Mel attenuates the Her-2-signaling pathway in OC of ethanol-preferring rats, providing an effective contribution for further development of adjuvant therapies.

No MeSH data available.


Related in: MedlinePlus

Immunohistochemical localization and Western blot analysis of p38 MAPK, PI3K, p-AKT, and mTOR in serous papillary OC. The immunoreaction of p38 MAPK was moderate in the OC (A) and OC+EtOH (C) groups while a weak reaction was observed in OC+Mel (B) and OC+EtOH+Mel (D) animals (arrow). Immunoreaction of PI3K was only moderate to weak in the surface epithelium of the OC (E) and a weak reaction was notable in the OC+Mel (F), OC+EtOH (G) and OC+EtOH+Mel (H) groups (arrow). A strong reaction to p-AKT was present in the papillae epithelium of the OC (I) and OC+EtOH (K) groups (arrows). The OC+Mel (J) and OC+EtOH+Mel (L) groups showed moderate and weak signals, respectively, for p-AKT (arrows). Reaction of mTOR was only weak in the OC+Mel (N) group, in contrast to moderate to high signals in the OC (M), OC+EtOH (O), and OC+EtOH+Mel (P) grups. Bar = 20 µm. Negative controls were used. (Q) Representative p38 MAPK, PI3K, p-AKT, and mTOR profiles of cytosolic extracts (70 µg protein) pooled from 10 samples/group (upper panel). (R-U) Extracts obtained from individual animals were used for densitometric analysis of the proteins following normalization to house-keeping genes (β-actin). All results are expressed as the mean ± SD (n = 10). a P < 0.05 versus OC; b P < 0.05 versus OC+EtOH. (V) Schematic representation of the EGFR/Her-2 signaling pathway leading to the activation of downstream molecules in OC cell. This activation occurs after the ligand binds to its specific receptor. Intracellular signaling results in the phosphorylation of PI3K, AKT, mTOR, S6k1, and ras. Lastly, p38 MAPK and S6k1 may be translocated to the nucleus to promote the transactivation of target genes related to inflammation, apoptosis, differentiation, and cell proliferation. Her-2, p38 MAPK, and p-AKT are downregulated by Mel and/or EtOH+Mel. Mel therapy also negatively regulated mTOR expression in OC.
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Figure 4: Immunohistochemical localization and Western blot analysis of p38 MAPK, PI3K, p-AKT, and mTOR in serous papillary OC. The immunoreaction of p38 MAPK was moderate in the OC (A) and OC+EtOH (C) groups while a weak reaction was observed in OC+Mel (B) and OC+EtOH+Mel (D) animals (arrow). Immunoreaction of PI3K was only moderate to weak in the surface epithelium of the OC (E) and a weak reaction was notable in the OC+Mel (F), OC+EtOH (G) and OC+EtOH+Mel (H) groups (arrow). A strong reaction to p-AKT was present in the papillae epithelium of the OC (I) and OC+EtOH (K) groups (arrows). The OC+Mel (J) and OC+EtOH+Mel (L) groups showed moderate and weak signals, respectively, for p-AKT (arrows). Reaction of mTOR was only weak in the OC+Mel (N) group, in contrast to moderate to high signals in the OC (M), OC+EtOH (O), and OC+EtOH+Mel (P) grups. Bar = 20 µm. Negative controls were used. (Q) Representative p38 MAPK, PI3K, p-AKT, and mTOR profiles of cytosolic extracts (70 µg protein) pooled from 10 samples/group (upper panel). (R-U) Extracts obtained from individual animals were used for densitometric analysis of the proteins following normalization to house-keeping genes (β-actin). All results are expressed as the mean ± SD (n = 10). a P < 0.05 versus OC; b P < 0.05 versus OC+EtOH. (V) Schematic representation of the EGFR/Her-2 signaling pathway leading to the activation of downstream molecules in OC cell. This activation occurs after the ligand binds to its specific receptor. Intracellular signaling results in the phosphorylation of PI3K, AKT, mTOR, S6k1, and ras. Lastly, p38 MAPK and S6k1 may be translocated to the nucleus to promote the transactivation of target genes related to inflammation, apoptosis, differentiation, and cell proliferation. Her-2, p38 MAPK, and p-AKT are downregulated by Mel and/or EtOH+Mel. Mel therapy also negatively regulated mTOR expression in OC.

Mentions: To investigate the effects of Mel upon Her-2-signaling pathway, the downstream molecules p38 MAPK, PI3K, p-AKT, and mTOR were measured in OC tissues. Curiously, Mel therapy downregulated p38 MAPK in the groups OC+Mel (1.46-fold reduced vs. OC; Fig. 4 A, B, Q, R) and OC+EtOH+Mel (1.29-fold reduced vs. OC+EtOH; Fig. 4 C, D, Q, R). While no significant differences (P > 0.05) were found in the expression of PI3K over the treatments (Fig. 4 E-H, Q, S), Mel therapy efficiently downregulated p-AKT in the groups OC+Mel (1.45-fold reduced vs. OC; Fig. 4 I, J, Q, T) and OC+EtOH+Mel (1.24-fold reduced vs. OC+EtOH; Fig. 4 K, L, Q, T). In addition, Mel therapy reduced the expression of mTOR in the OC+Mel group (1.37-fold reduced vs. OC; Fig 4 M, N, Q, U), but not in the presence of EtOH (P > 0.05; Fig 4 O, P, Q, U). Briefly, Figure 4 V indicates the positive or negative regulatory signals produced by Mel therapy or EtOH intake on Her-2 activation, and related downstream molecules (p38 MAPK, p-AKT, mTOR) in the "in vivo" OC cell.


Melatonin Attenuates Her-2, p38 MAPK, p-AKT, and mTOR Levels in Ovarian Carcinoma of Ethanol-Preferring Rats.

Ferreira GM, Martinez M, Camargo IC, Domeniconi RF, Martinez FE, Chuffa LG - J Cancer (2014)

Immunohistochemical localization and Western blot analysis of p38 MAPK, PI3K, p-AKT, and mTOR in serous papillary OC. The immunoreaction of p38 MAPK was moderate in the OC (A) and OC+EtOH (C) groups while a weak reaction was observed in OC+Mel (B) and OC+EtOH+Mel (D) animals (arrow). Immunoreaction of PI3K was only moderate to weak in the surface epithelium of the OC (E) and a weak reaction was notable in the OC+Mel (F), OC+EtOH (G) and OC+EtOH+Mel (H) groups (arrow). A strong reaction to p-AKT was present in the papillae epithelium of the OC (I) and OC+EtOH (K) groups (arrows). The OC+Mel (J) and OC+EtOH+Mel (L) groups showed moderate and weak signals, respectively, for p-AKT (arrows). Reaction of mTOR was only weak in the OC+Mel (N) group, in contrast to moderate to high signals in the OC (M), OC+EtOH (O), and OC+EtOH+Mel (P) grups. Bar = 20 µm. Negative controls were used. (Q) Representative p38 MAPK, PI3K, p-AKT, and mTOR profiles of cytosolic extracts (70 µg protein) pooled from 10 samples/group (upper panel). (R-U) Extracts obtained from individual animals were used for densitometric analysis of the proteins following normalization to house-keeping genes (β-actin). All results are expressed as the mean ± SD (n = 10). a P < 0.05 versus OC; b P < 0.05 versus OC+EtOH. (V) Schematic representation of the EGFR/Her-2 signaling pathway leading to the activation of downstream molecules in OC cell. This activation occurs after the ligand binds to its specific receptor. Intracellular signaling results in the phosphorylation of PI3K, AKT, mTOR, S6k1, and ras. Lastly, p38 MAPK and S6k1 may be translocated to the nucleus to promote the transactivation of target genes related to inflammation, apoptosis, differentiation, and cell proliferation. Her-2, p38 MAPK, and p-AKT are downregulated by Mel and/or EtOH+Mel. Mel therapy also negatively regulated mTOR expression in OC.
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Related In: Results  -  Collection

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Figure 4: Immunohistochemical localization and Western blot analysis of p38 MAPK, PI3K, p-AKT, and mTOR in serous papillary OC. The immunoreaction of p38 MAPK was moderate in the OC (A) and OC+EtOH (C) groups while a weak reaction was observed in OC+Mel (B) and OC+EtOH+Mel (D) animals (arrow). Immunoreaction of PI3K was only moderate to weak in the surface epithelium of the OC (E) and a weak reaction was notable in the OC+Mel (F), OC+EtOH (G) and OC+EtOH+Mel (H) groups (arrow). A strong reaction to p-AKT was present in the papillae epithelium of the OC (I) and OC+EtOH (K) groups (arrows). The OC+Mel (J) and OC+EtOH+Mel (L) groups showed moderate and weak signals, respectively, for p-AKT (arrows). Reaction of mTOR was only weak in the OC+Mel (N) group, in contrast to moderate to high signals in the OC (M), OC+EtOH (O), and OC+EtOH+Mel (P) grups. Bar = 20 µm. Negative controls were used. (Q) Representative p38 MAPK, PI3K, p-AKT, and mTOR profiles of cytosolic extracts (70 µg protein) pooled from 10 samples/group (upper panel). (R-U) Extracts obtained from individual animals were used for densitometric analysis of the proteins following normalization to house-keeping genes (β-actin). All results are expressed as the mean ± SD (n = 10). a P < 0.05 versus OC; b P < 0.05 versus OC+EtOH. (V) Schematic representation of the EGFR/Her-2 signaling pathway leading to the activation of downstream molecules in OC cell. This activation occurs after the ligand binds to its specific receptor. Intracellular signaling results in the phosphorylation of PI3K, AKT, mTOR, S6k1, and ras. Lastly, p38 MAPK and S6k1 may be translocated to the nucleus to promote the transactivation of target genes related to inflammation, apoptosis, differentiation, and cell proliferation. Her-2, p38 MAPK, and p-AKT are downregulated by Mel and/or EtOH+Mel. Mel therapy also negatively regulated mTOR expression in OC.
Mentions: To investigate the effects of Mel upon Her-2-signaling pathway, the downstream molecules p38 MAPK, PI3K, p-AKT, and mTOR were measured in OC tissues. Curiously, Mel therapy downregulated p38 MAPK in the groups OC+Mel (1.46-fold reduced vs. OC; Fig. 4 A, B, Q, R) and OC+EtOH+Mel (1.29-fold reduced vs. OC+EtOH; Fig. 4 C, D, Q, R). While no significant differences (P > 0.05) were found in the expression of PI3K over the treatments (Fig. 4 E-H, Q, S), Mel therapy efficiently downregulated p-AKT in the groups OC+Mel (1.45-fold reduced vs. OC; Fig. 4 I, J, Q, T) and OC+EtOH+Mel (1.24-fold reduced vs. OC+EtOH; Fig. 4 K, L, Q, T). In addition, Mel therapy reduced the expression of mTOR in the OC+Mel group (1.37-fold reduced vs. OC; Fig 4 M, N, Q, U), but not in the presence of EtOH (P > 0.05; Fig 4 O, P, Q, U). Briefly, Figure 4 V indicates the positive or negative regulatory signals produced by Mel therapy or EtOH intake on Her-2 activation, and related downstream molecules (p38 MAPK, p-AKT, mTOR) in the "in vivo" OC cell.

Bottom Line: While Mel therapy was unable to reduce Her-4 and phosphoinositide 3-kinase (PI3K) levels, it was able to suppress the OC-related increase in the levels of the Her-2, p38 mitogen-activated protein kinases (p38 MAPK), protein kinase B (phospho-AKT), and mammalian target of rapamycin (mTOR).In addition, Mel significantly attenuated the expression of Her-2, p38 MAPK, and p-AKT, which are involved in OC signaling during ethanol intake.Collectively, our results suggest that Mel attenuates the Her-2-signaling pathway in OC of ethanol-preferring rats, providing an effective contribution for further development of adjuvant therapies.

View Article: PubMed Central - PubMed

Affiliation: 1. Department of Anatomy, Biosciences Institute, UNESP - Univ. Estadual Paulista, Botucatu-SP, Brazil, 18618-970.

ABSTRACT
Epidermal growth factor receptors 2 (Her-2) and 4 (Her-4) are closely associated with ovarian cancer (OC) progression and metastasis, and a more complete understanding of these signaling pathways allow the development of new therapeutic strategies. Melatonin (Mel) is recognized as having several anticancer properties and has been reported to modulate Her-2 system in aggressive tumors. Here, we investigated OC and the role of Mel therapy on the Her-2- and Her-4-signaling pathway related to downstream molecules in an ethanol-preferring rat model. To induce OC, the left ovary was injected directly with a single dose of 100 µg 7,12-dimethylbenz(a)anthracene (DMBA) dissolved in 10 µL of sesame oil under the bursa. Right ovaries were used as sham-surgery controls. After developing OC, half of the animals received i.p. injections of Mel (200 µg/100 g b.w./day) for 60 days. While Mel therapy was unable to reduce Her-4 and phosphoinositide 3-kinase (PI3K) levels, it was able to suppress the OC-related increase in the levels of the Her-2, p38 mitogen-activated protein kinases (p38 MAPK), protein kinase B (phospho-AKT), and mammalian target of rapamycin (mTOR). In addition, Mel significantly attenuated the expression of Her-2, p38 MAPK, and p-AKT, which are involved in OC signaling during ethanol intake. Collectively, our results suggest that Mel attenuates the Her-2-signaling pathway in OC of ethanol-preferring rats, providing an effective contribution for further development of adjuvant therapies.

No MeSH data available.


Related in: MedlinePlus