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Suppression of MAPK Signaling and Reversal of mTOR-Dependent MDR1-Associated Multidrug Resistance by 21α-Methylmelianodiol in Lung Cancer Cells.

Aldonza MB, Hong JY, Bae SY, Song J, Kim WK, Oh J, Shin Y, Lee SH, Lee SK - PLoS ONE (2015)

Bottom Line: Interplay between PI3K/AMPK/AKT and MAPK pathways is a crucial effector in lung cancer growth and progression.Here, we described whether 21α-Methylmelianodiol (21α-MMD), an active triterpenoid derivative of Poncirus trifoliate, can display anticancer properties by regulating these signals and modulate the occurrence of multidrug resistance in NSCLC cells.Employing the established paclitaxel-resistant A549 cells (A549-PacR), we further found that 21α-MMD induced a MDR reversal activity through the inhibition of P-gp/MDR1 expressions, function, and transcription with regained paclitaxel sensitivity which might dependently correlate to the regulation of PI3K/mTOR signaling pathway.

View Article: PubMed Central - PubMed

Affiliation: College of Pharmacy, Seoul National University, Seoul, Korea.

ABSTRACT
Lung cancer is the leading cause of cancer-related deaths worldwide and remains the most prevalent. Interplay between PI3K/AMPK/AKT and MAPK pathways is a crucial effector in lung cancer growth and progression. These signals transduction protein kinases serve as good therapeutic targets for non-small cell lung cancer (NSCLC) which comprises up to 90% of lung cancers. Here, we described whether 21α-Methylmelianodiol (21α-MMD), an active triterpenoid derivative of Poncirus trifoliate, can display anticancer properties by regulating these signals and modulate the occurrence of multidrug resistance in NSCLC cells. We found that 21α-MMD inhibited the growth and colony formation of lung cancer cells without affecting the normal lung cell phenotype. 21α-MMD also abrogated the metastatic activity of lung cancer cells through the inhibition of cell migration and invasion, and induced G0/G1 cell cycle arrest with increased intracellular ROS generation and loss of mitochondrial membrane integrity. 21α-MMD regulated the expressions of PI3K/AKT/AMPK and MAPK signaling which drove us to further evaluate its activity on multidrug resistance (MDR) in lung cancer cells by specifying on P-glycoprotein (P-gp)/MDR1-association. Employing the established paclitaxel-resistant A549 cells (A549-PacR), we further found that 21α-MMD induced a MDR reversal activity through the inhibition of P-gp/MDR1 expressions, function, and transcription with regained paclitaxel sensitivity which might dependently correlate to the regulation of PI3K/mTOR signaling pathway. Taken together, these findings demonstrate, for the first time, the mechanistic evaluation in vitro of 21α-MMD displaying growth-inhibiting potential with influence on MDR reversal in human lung cancer cells.

No MeSH data available.


Related in: MedlinePlus

Regulation of the PI3K/AMPK/AKT, mTOR and MAPK signaling pathways by 21α-MMD in lung cancer cells.A549 or H1299 cells were incubated with various concentrations of 21α-MMD for 24 h. Cell lysates were subjected to Western blotting and probed using anti-ERK, anti-JNK, anti-p38, anti-Akt, anti-mTOR, anti-PI3K, anti-AMPK antibodies as well as antibodies for their phosphorylated forms. The β-actin and phospho-protein relevant to the total protein bands confirmed the integrity and equal loading of total and phospho-proteins respectively. All protein levels were normalized to the β-actin levels.
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pone.0127841.g004: Regulation of the PI3K/AMPK/AKT, mTOR and MAPK signaling pathways by 21α-MMD in lung cancer cells.A549 or H1299 cells were incubated with various concentrations of 21α-MMD for 24 h. Cell lysates were subjected to Western blotting and probed using anti-ERK, anti-JNK, anti-p38, anti-Akt, anti-mTOR, anti-PI3K, anti-AMPK antibodies as well as antibodies for their phosphorylated forms. The β-actin and phospho-protein relevant to the total protein bands confirmed the integrity and equal loading of total and phospho-proteins respectively. All protein levels were normalized to the β-actin levels.

Mentions: Dysregulation in PI3K/AKT/mTOR, AMPK, and MAPKs pathways are often existent in cancer primarily due to deletion and post-translational modifications [35]. Since the activation of the PI3K/AMPK/AKT/mTOR pathway is shown to cause the development of a more aggressive lung cancer phenotype which correlates to poor prognosis for patients [36], we assessed whether 21α-MMD affects these signals. Strikingly, as for the mTOR signaling, 21α-MMD caused significant concomitant dose-dependent suppressive expressions of PI3K, Akt, mTOR and their respective phosphorylated forms in both A549 and H1299 cells for 24 h. It is known that the inhibition of the mTOR pathway could trigger cancer autophagy [37]. Interplay between the PI3K/mTOR and MAPK pathways has been identified as a critical factor in oncogenesis, specifically to that of lung cancer [38]. Treatment with 21α-MMD resulted in a dose-dependent suppression of total ERK, phospho-ERK, total JNK, phospho-JNK and p38 MAPK expressions in A549 cells with observed significant inhibition of phospho-p38 at 100 μM for 24 h. In H1299 cells, 21α-MMD also significantly down-regulated the activation of protein expressions of ERK, JNK, and p38. Pharmacological activation of AMPK has recently been shown to induce cytotoxicity to many established solid cancer cell lines and human cancer xenografts [39]. We confirmed that 21α-MMD significantly triggered the activation of the AMPK and its phosphorylation in a dose-dependent manner in both A549 and H1299 cells for 24 h (Fig 4). These findings reveal the rationale behind the mechanism of action of 21α-MMD to suppress growth, survival, and metastatic potential of lung cancer cells.


Suppression of MAPK Signaling and Reversal of mTOR-Dependent MDR1-Associated Multidrug Resistance by 21α-Methylmelianodiol in Lung Cancer Cells.

Aldonza MB, Hong JY, Bae SY, Song J, Kim WK, Oh J, Shin Y, Lee SH, Lee SK - PLoS ONE (2015)

Regulation of the PI3K/AMPK/AKT, mTOR and MAPK signaling pathways by 21α-MMD in lung cancer cells.A549 or H1299 cells were incubated with various concentrations of 21α-MMD for 24 h. Cell lysates were subjected to Western blotting and probed using anti-ERK, anti-JNK, anti-p38, anti-Akt, anti-mTOR, anti-PI3K, anti-AMPK antibodies as well as antibodies for their phosphorylated forms. The β-actin and phospho-protein relevant to the total protein bands confirmed the integrity and equal loading of total and phospho-proteins respectively. All protein levels were normalized to the β-actin levels.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4476707&req=5

pone.0127841.g004: Regulation of the PI3K/AMPK/AKT, mTOR and MAPK signaling pathways by 21α-MMD in lung cancer cells.A549 or H1299 cells were incubated with various concentrations of 21α-MMD for 24 h. Cell lysates were subjected to Western blotting and probed using anti-ERK, anti-JNK, anti-p38, anti-Akt, anti-mTOR, anti-PI3K, anti-AMPK antibodies as well as antibodies for their phosphorylated forms. The β-actin and phospho-protein relevant to the total protein bands confirmed the integrity and equal loading of total and phospho-proteins respectively. All protein levels were normalized to the β-actin levels.
Mentions: Dysregulation in PI3K/AKT/mTOR, AMPK, and MAPKs pathways are often existent in cancer primarily due to deletion and post-translational modifications [35]. Since the activation of the PI3K/AMPK/AKT/mTOR pathway is shown to cause the development of a more aggressive lung cancer phenotype which correlates to poor prognosis for patients [36], we assessed whether 21α-MMD affects these signals. Strikingly, as for the mTOR signaling, 21α-MMD caused significant concomitant dose-dependent suppressive expressions of PI3K, Akt, mTOR and their respective phosphorylated forms in both A549 and H1299 cells for 24 h. It is known that the inhibition of the mTOR pathway could trigger cancer autophagy [37]. Interplay between the PI3K/mTOR and MAPK pathways has been identified as a critical factor in oncogenesis, specifically to that of lung cancer [38]. Treatment with 21α-MMD resulted in a dose-dependent suppression of total ERK, phospho-ERK, total JNK, phospho-JNK and p38 MAPK expressions in A549 cells with observed significant inhibition of phospho-p38 at 100 μM for 24 h. In H1299 cells, 21α-MMD also significantly down-regulated the activation of protein expressions of ERK, JNK, and p38. Pharmacological activation of AMPK has recently been shown to induce cytotoxicity to many established solid cancer cell lines and human cancer xenografts [39]. We confirmed that 21α-MMD significantly triggered the activation of the AMPK and its phosphorylation in a dose-dependent manner in both A549 and H1299 cells for 24 h (Fig 4). These findings reveal the rationale behind the mechanism of action of 21α-MMD to suppress growth, survival, and metastatic potential of lung cancer cells.

Bottom Line: Interplay between PI3K/AMPK/AKT and MAPK pathways is a crucial effector in lung cancer growth and progression.Here, we described whether 21α-Methylmelianodiol (21α-MMD), an active triterpenoid derivative of Poncirus trifoliate, can display anticancer properties by regulating these signals and modulate the occurrence of multidrug resistance in NSCLC cells.Employing the established paclitaxel-resistant A549 cells (A549-PacR), we further found that 21α-MMD induced a MDR reversal activity through the inhibition of P-gp/MDR1 expressions, function, and transcription with regained paclitaxel sensitivity which might dependently correlate to the regulation of PI3K/mTOR signaling pathway.

View Article: PubMed Central - PubMed

Affiliation: College of Pharmacy, Seoul National University, Seoul, Korea.

ABSTRACT
Lung cancer is the leading cause of cancer-related deaths worldwide and remains the most prevalent. Interplay between PI3K/AMPK/AKT and MAPK pathways is a crucial effector in lung cancer growth and progression. These signals transduction protein kinases serve as good therapeutic targets for non-small cell lung cancer (NSCLC) which comprises up to 90% of lung cancers. Here, we described whether 21α-Methylmelianodiol (21α-MMD), an active triterpenoid derivative of Poncirus trifoliate, can display anticancer properties by regulating these signals and modulate the occurrence of multidrug resistance in NSCLC cells. We found that 21α-MMD inhibited the growth and colony formation of lung cancer cells without affecting the normal lung cell phenotype. 21α-MMD also abrogated the metastatic activity of lung cancer cells through the inhibition of cell migration and invasion, and induced G0/G1 cell cycle arrest with increased intracellular ROS generation and loss of mitochondrial membrane integrity. 21α-MMD regulated the expressions of PI3K/AKT/AMPK and MAPK signaling which drove us to further evaluate its activity on multidrug resistance (MDR) in lung cancer cells by specifying on P-glycoprotein (P-gp)/MDR1-association. Employing the established paclitaxel-resistant A549 cells (A549-PacR), we further found that 21α-MMD induced a MDR reversal activity through the inhibition of P-gp/MDR1 expressions, function, and transcription with regained paclitaxel sensitivity which might dependently correlate to the regulation of PI3K/mTOR signaling pathway. Taken together, these findings demonstrate, for the first time, the mechanistic evaluation in vitro of 21α-MMD displaying growth-inhibiting potential with influence on MDR reversal in human lung cancer cells.

No MeSH data available.


Related in: MedlinePlus