Lung cancer is the leading cause of cancer-related deaths worldwide. Squamous cell carcinoma is one of the predominant histological subtypes of lung cancer. Detecting lung cancer at an early stage is essential for successful therapy and increasing survival. There are still no satisfactory biomarkers for the early detection of lung cancer. In this study, tumour tissue paired with tumour-adjacent normal bronchial epithelial tissue was obtained from patients with squamous cell lung carcinoma without metastasis. The proteins extracted from the cell membrane were separated by two-dimensional polyacrylamide gel electrophoresis (2-DE) and were analysed with the Image Master two-dimensional platinum software. Twenty-five significantly different protein spots were selected and identified with matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). A total of 19 proteins were successfully identified. Twelve proteins were up-regulated, and seven proteins were down-regulated in the cancerous tissue compared with the tumour-adjacent normal tissue. One up-regulated protein and one down-regulated protein in squamous cell lung carcinoma were verified by Western blot analysis and RT-PCR; the results were consistent with the 2-DE analysis. In conclusion, membrane proteomics identified a number of candidate biomarker proteins that were differentially expressed between squamous cell lung cancer tissue and adjacent normal tissue. These biomarker candidates have the potential to elucidate the underlying pathogenesis of squamous cell lung cancer.
"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 [1,2]. Although initial use of platin-based cytotoxic chemotherapy improved the overall survival rate and life quality of the patients, the outcome remains poor due to deleterious development of drug resistance resulting in less than 15% lung cancer patients surviving for at least five years [2,3]. Approximately 80 - 85% of the lung cancer patients are diagnosed with an advanced stage of non-small cell lung cancer (NSCLC) that has limited therapeutic options due to metastasis [1,4,5] and among the three types of NSCLC, patients identified with squamous carcinoma which involves lymph node metastasis accounts for 60% [5,6]. "
[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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-1alpha 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.
Phyllanthus inhibits A549 metastasis by suppressing ERK1/2 and hypoxia pathways that led to suppression of various critical proteins for A549 invasion and migration.
BMC Complementary and Alternative Medicine 10/2013; 13(1):271. DOI:10.1186/1472-6882-13-271 · 2.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The correct understanding of tumour development relies on the comprehensive study of proteins. They are the main orchestrators of vital processes, such as signalling pathways, which drive the carcinogenic process. Proteomic technologies can be applied to cancer research to detect differential protein expression and to assess different responses to treatment. Lung cancer is the number one cause of cancer-related death in the world. Mostly diagnosed at late stages of the disease, lung cancer has one of the lowest 5-year survival rates at 15 %. The use of different proteomic techniques such as two-dimensional gel electrophoresis (2D-PAGE), isotope labelling (ICAT, SILAC, iTRAQ) and mass spectrometry may yield new knowledge on the underlying biology of lung cancer and also allow the development of new early detection tests and the identification of changes in the cancer protein network that are associated with prognosis and drug resistance.
[Show abstract][Hide abstract] ABSTRACT: This review provides an introduction to stable isotope dilution mass spectrometry (MS) and its emerging applications in the analysis of membrane transporter proteins. Various approaches and application examples, for the generation and use of quantitation reference standards-either stable isotope-labeled peptides or proteins-are discussed as they apply to the MS quantitation of membrane proteins. Technological considerations for the sample preparation of membrane transporter proteins are also presented.
The AAPS Journal 09/2013; 15(4). DOI:10.1208/s12248-013-9529-8 · 3.80 Impact Factor
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