tachyplesin-peptide--tachypleus-tridentatus and Lung-Neoplasms

Cisplatin has strong broad-spectrum anticancer activity and is one of the most effective anticancer drugs currently used. The clinical application of cisplatin has led to the resistance of cancer cells to cisplatin. Tachyplesin is an active, natural marine peptide with antitumour activity. In the present study, we investigated whether tachyplesin can be used in non-small cell lung cancer (NSCLC) A549 and H460 cells as well as the cisplatin-resistant human A549/DDP NSCLC cell line. The results revealed that tachyplesin treatment significantly inhibited proliferation and induced apoptosis in A549 and H460 cells and the combination of tachyplesin and cisplatin significantly suppressed migration and improved sensitivity to cisplatin in A549/DDP cells. Further mechanistic examination revealed that tachyplesin induced apoptosis in A549/DDP cells by increasing Fas, FasL and p-RIPK1 levels. These results indicated that tachyplesin induces lung cancer death by activating the Fas, mitochondrial and necroptosis pathways. Tachyplesin could be developed as a candidate drug for cisplatin-resistant NSCLC.

Topics: Antimicrobial Cationic Peptides; Antineoplastic Agents; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Movement; Cisplatin; DNA-Binding Proteins; Drug Resistance, Neoplasm; fas Receptor; Humans; Lung Neoplasms; Membrane Potential, Mitochondrial; Necroptosis; Peptides, Cyclic; Up-Regulation

The importance of the antitumor activity of some antimicrobial peptides (AMPs) is being increasingly recognized. The antimicrobial peptide, tachyplesin, has been shown to exhibit anticancer properties and a linear, cysteine deleted analogue (CDT), was found to retain its antibacterial function.. The objective was to test CDT and related analogues against normal mammalian, bacterial, and cancer cells to determine their effectiveness and then utilize specific assays to determine a possible mechanism of action.. We used sequence reversal and D-amino acids to synthesize four CDT analogues by solid phase peptide synthesis. A number of assays were used including liposome dye-leakage, antibacterial activity against both Gram-positive and Gram-negative bacterial strains, hemolytic assays, methyl thiazolyl tetrazolium (MTT), and apoptosis to examine their effectiveness as both AMPs and anti-cancer peptides (ACPs). We then tested the analogues for their ability to inhibit proliferation of the human lung cancer cell line, A549.. We found that D-CDT exhibited the best bactericidal properties of those tested and was not damaging to red blood cells. Both D-CDT and reverse D-CDT showed a dose-dependent reduction of cell viability. However, D-CDT was most effective with an IC50 of 9.814 μM, a value 9-fold lower than that calculated for reverse D-CDT (90.16 μM). Apoptosis does not appear to be a mechanism by which D-CDT exerts its anticancer properties since > 100 μM was required to increase activation of caspase 3. Moreover, the ERK1/2 pathway is also unlikely since only a modest (20%) decrease of activity was observed with > 100 μM D-CDT. However, D-CDT was found to operate via a hyaluronan (HA)-dependent mechanism as pretreatment of the cells with hyaluronidase decreased the cytotoxic effects of D-CDT on A549 cells and increased its IC50 29-fold to 283.9 μM.. D-CDT is both an effective AMP and ACP, and likely exerts its anticancer effects through both membranolytic as well as an HA-mediated mechanism.

Topics: A549 Cells; Adenocarcinoma; Adenocarcinoma of Lung; Amino Acid Sequence; Amino Acids; Antimicrobial Cationic Peptides; Apoptosis; Cell Proliferation; Cysteine; DNA-Binding Proteins; Drug Screening Assays, Antitumor; Gram-Negative Bacteria; Humans; Lung Neoplasms; MAP Kinase Signaling System; Peptides, Cyclic