Antitumor Activity of Bioactive Compounds from Rapana venosa against Human Breast Cell Lines

Abstract

This study is the first report describing the promising antitumor activity of biologically active compounds isolated from the hemolymph of marine snail Rapana venosa—a fraction with Mw between 50 and 100 kDa and two structural subunits (RvH1 and RvH2), tested on a panel of human breast cell lines—six lines of different molecular subtypes of breast cancer MDA-MB-231, MDA-MB-468, BT-474, BT-549, SK-BR-3, and MCF-7 and the non-cancerous MCF-10A. The fraction with Mw 50–100 kDa (HRv 50–100) showed good antitumor activity manifested by a significant decrease in cell viability, altered morphology, autophagy, and p53 activation in treated cancer cells. An apparent synergistic effect was observed for the combination of HRv 50–100 with cis-platin for all tested cell lines. The combination of HRv 50–100 with cisplatin and/or tamoxifen is three times more effective compared to treatment with classical chemotherapeutics alone. The main proteins in the active fraction, with Mw at ~50 kDa, ~65 kDa, ~100 kDa, were identified by MALDI-MS, MS/MS analyses, and bioinformatics. Homology was established with known proteins with antitumor potential detected in different mollusc species: peroxidase-like protein, glycoproteins Aplysianin A, L-amino acid oxidase (LAAO), and the functional unit with Mw 50 kDa of RvH. Our study reveals new perspectives for application of HRv 50–100 as an antitumor agent used alone or as a booster in combination with different chemotherapies.

Antibacterial Action of Protein Fraction Isolated from Rapana venosa Hemolymph against Escherichia coli NBIMCC 8785

“…The identified protein band at 50.230 kDa most likely included functional units (FUs) of R. venosa hemocyanin derived from endogenous proteolytic processes [ 30 , 31 ].…”

“…In order to confirm some of these proteins, the protein bands from 12% SDS-PAGE were excised from the gel and, after trypsin digestion, the extracted peptides were analyzed by mass spectrometry, as presented in study [ 31 ]. The amino acid sequences (AASs) for extracted peptides from each protein band were determined by de novo MS/MS analyses as described in [ 31 ], because Mascot search of the experimentally determined peptide masses as [M + H] + , after trypsin digestion, did not lead to satisfactory results. In Figure 2 is presented the MALDI-MS/MS spectrum of peptide [M + H] + at m / z 1274.68 extracted from the protein band at 61.106 kDa.…”

“…After alignment of the identified amino acid sequence (LDWPVLFNDR) for peptide [M + H] + at m / z 1274.68 with a database for extracellular proteins from gastropods by the Basic Local Alignment Search Tool (BLAST), we established a high homology (83%) with Aplysianin-A of Aplysia kurodai. In this way were determined the other proteins presented in Table 1 [ 31 ].…”

“…Several studies have shown that different proteins are present in the hemolymph of molluscs, such as different forms of hemocyanin, protease inhibitors, alpha-2-macroglobulin, a putative clotting protein, actin and many others [ 23 ]. Although, up to now, some extracellular proteins in R. venosa hemolymph have been identified, such as actin, some functional units of hemocyanin RvH, etc., as well as antimicrobial proline-rich peptides, the remaining proteins are still unknown [ 17 , 30 , 31 , 41 ].…”

“…The presence of proteins with L-AAO activity in the protein band at 61.106 kDa in the Rv 50–100 kDa fraction may explain not only the observed antibacterial activity against E. coli but also the high antifungal activity of this fraction against six pathogenic strains [ 29 ], as well as recently established antitumor activity [ 31 ].…”