Inhibition of Raf-MEK-ERK and Hypoxia pathways by Phyllanthus prevents metastasis in human lung (A549) cancer cell line

Lee, S.H. and Jaganath, I.B. and Manikam, R. and Sekaran, S.D. (2013) Inhibition of Raf-MEK-ERK and Hypoxia pathways by Phyllanthus prevents metastasis in human lung (A549) cancer cell line. BMC Complementary and Alternative Medicine, 13. ISSN 1472-6882,

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Background: Lung cancer constitutes one of the malignancies with the greatest incidence and mortality rates with 1.6 million new cases and 1.4 million deaths each year. Prognosis remains poor due to deleterious development of multidrug resistance resulting in less than 15 lung cancer patients reaching five years survival. We have previously shown that Phyllanthus induced apoptosis in conjunction with its antimetastastic action. In the current study, we aimed to determine the signaling pathways utilized by Phyllanthus to exert its antimetastatic activities. Methods: Cancer 10-pathway reporter array was performed to screen the pathways affected by Phyllanthus in lung carcinoma cell line (A549) to exert its antimetastatic effects. Results from this array were then confirmed with western blotting, cell cycle analysis, zymography technique, and cell based ELISA assay for human total iNOS. Two-dimensional gel electrophoresis was subsequently carried out to study the differential protein expressions in A549 after treatment with Phyllanthus. Results: Phyllanthus was observed to cause antimetastatic activities by inhibiting ERK1/2 pathway via suppression of Raf protein. Inhibition of this pathway resulted in the suppression of MMP2, MMP7, and MMP9 expression to stop A549 metastasis. Phyllanthus also inhibits hypoxia pathway via inhibition of HIF-1 alpha that led to reduced VEGF and iNOS expressions. Proteomic analysis revealed a number of proteins downregulated by Phyllanthus that were involved in metastatic processes, including invasion and mobility proteins (cytoskeletal proteins), transcriptional proteins (proliferating cell nuclear antigen; zinc finger protein), antiapoptotic protein (Bcl2) and various glycolytic enzymes. Among the four Phyllanthus species tested, P. urinaria showed the greatest antimetastatic activity. Conclusions: Phyllanthus inhibits A549 metastasis by suppressing ERK1/2 and hypoxia pathways that led to suppression of various critical proteins for A549 invasion and migration.

Item Type: Article
Additional Information: ISI Document Delivery No.: 271AX Times Cited: 0 Cited Reference Count: 63 Lee, Sau Har Jaganath, Indu Bala Manikam, Rishya Sekaran, Shamala Devi University Malaya Research Grant RG391/11HTM; University Malaya IPPP Grants PS180/2010A, PV053/2011B We thank Ms Anusyah Rathakrishnan and Dr Soh Chen Loong for editing the English language of this manuscript. This project was funded by University Malaya Research Grant (RG391/11HTM) and University Malaya IPPP Grants (PS180/2010A; PV053/2011B). Biomed central ltd London
Uncontrolled Keywords: Phyllanthus, Metastasis, Apoptosis, ERK1/2, HIF-1 alpha, posttranslational modifications, signaling pathways, proteomic analysis, down-regulation, kinase cascade, proteins, expression, identification, carcinoma, apoptosis
Subjects: R Medicine
Divisions: Faculty of Medicine
Depositing User: Ms azrahani halim
Date Deposited: 20 Aug 2014 01:24
Last Modified: 14 Jul 2017 07:03

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