The Open Proteomics Journal

2011, 4 : 1-11
Published online 2011 February 24. DOI: 10.2174/1875039701104010001
Publisher ID: TOPROTJ-4-1

Proteomics Profiling and Cytotoxic Effect of Curcuma longa on Prostate Cancer

Kurapati V.K. Rao , Nawal M. Nawal M. Boukli , Thangavel Samikkannu , Luis A. Cubano , Babu K. Dakshayani and Madhavan P.N. Nair
Professor and Chair of Immunology Associate Dean of Bio-Medical Research College of Medicine Florida International University University Park 11200 S.W. 8th Street Miami, FL 33199, USA;.

ABSTRACT

Turmeric (Curcuma longa) has been shown to possess anti-inflammatory, antioxidant and antitumor properties. Extraction, partition and column chromatography of the dry powder of C. longa rhizomes showed presence of biological activity only in ethyl acetate eluted fraction in clonogenic assays using highly metastatic PC-3M prostate cancer cell line. HPLC, UV-Vis and Mass spectra studies showed presence of three curcuminoids in this fraction. Accordingly, we have made an attempt to identify the proteins modulated by purified turmeric fraction in PC-3M human prostate cancer cell line using high-resolution two-dimensional gel electrophoresis (2-DE). Isoelectric focusing and 2-DE analysis showed a total of 29 proteins altered by treatment with ethyl acetate fraction (EAF) of C. longa. Out of 29 differentially expressed proteins, 15 were identified by peptide mass fingerprinting through LC/MS/MS sequencing. From these, a total of 7 were down-regulated and 8 were up-regulated spots. The down-regulated proteins identified by Peptide Mass Fingerprinting are Elongation Factor 2 (eEF2), Stress-induced phosphoprotein 1, Glutathione S-transferase (GST) Omega-1, Parvalbumin alpha, Succinyl-CoA: ketoacid, Lamin-A/C and Annexin A2. The up-regulated proteins identified by Peptide Mass Fingerprinting include 78 kDa Glucose-regulated protein precursor (GRP78), Protein disulfide isomerase (PDI) precursor, Actin cytoplasmic 2, protein SET, Calreticulin precursor, Nucleophosmin, Vimentin, and Aortic alpha-actin (ACTA2). The identified proteins have diverse cellular functions such as ER stress, Unfolded Protein Response (UPR), cytoskeletal, structural, regulatory, and apoptotic proteins that will require further in-depth studies to understand the biological significance.

Keywords:

Curcuma longa, ethyl acetate fraction, curcuminoids, 2-DE, LC/MS/MS sequencing..