kla-peptide and Neoplasms

The stimuli-responsive conformational transformation of peptides possessing a constrained form triggered by specific biological microenvironment would provide an effective strategy for the development of highly specific peptide therapeutics. Here, we developed a peptide containing a cytotoxic helical KLA sequence with therapeutic specificity through the use of stimuli-responsive conformational transformation. The KLA peptide is modified to form a cyclic structure to allow for constrained helicity that confers low cytotoxicity. The modified KLA peptide is electrostatically complexed to hyaluronic acid to facilitate enhanced endocytosis into the cancer cells. After endocytosis, the peptide is released from the complex into the cellular cytoplasm by hyaluronidases on the surface of the cellular membrane. Specific intracellular stimuli then trigger the release of the strain that suppresses peptide helicity, and the inherent helical conformation of the KLA peptide is restored. Therefore, the stimuli-responsive conformational transformation of a peptide from low to high helicity selectively induces cell death by disruption of the plasma and mitochondrial membrane.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Survival; Drug Discovery; Humans; Intercellular Signaling Peptides and Proteins; Mitochondrial Membranes; Models, Molecular; Neoplasms; Protein Conformation, alpha-Helical

In recent decades, drug self-delivery systems (DSDSs) have appeared with extraordinary superiority for cancer therapy while realizing intracellular delivery without supererogatory drug carriers. Here, we have designed and programmed a novel self-delivery system to realize tumor targeting therapy. The amphiphilic proapoptotic peptide KLAKLAKKLAKLAKGCK(Fmoc)

Topics: Antineoplastic Agents; Doxorubicin; Drug Delivery Systems; Drug Liberation; Humans; Hyaluronan Receptors; Hyaluronic Acid; Hyaluronoglucosaminidase; Intercellular Signaling Peptides and Proteins; Neoplasms

Topics: Antineoplastic Combined Chemotherapy Protocols; Cell Survival; Doxorubicin; Drug Carriers; Drug Delivery Systems; Drug Liberation; Drug Synergism; HeLa Cells; Humans; Intercellular Signaling Peptides and Proteins; Microscopy, Electron, Transmission; Nanoparticles; Neoplasms; Peptides; Porosity; Silicon Dioxide

Low molecular weight heparin (LMWH) is a natural sulfated glycosaminoglycan with the affinity to proangiogenic factors, rendering it a promising agent for tumor therapy. Inspired by DOX binding to the helix of DNA, mitochondrial damage KLA peptide derivative (mKLA) and anti-angiogenic LMWH-chrysin conjugate (LC) are constructed to simulate the double strands for doxorubicin (DOX) binding (LKD nanocomplex). Initiated and "locked" by DOX, mKLA and LC temporarily aggregate by π-π stacks, electrostatic and hydrophobic interactions in aqueous condition with self-amplified DOX loading (19.07 ± 1.08 wt%). During endosome-lysosome trafficking, DOX protonated by H

Topics: Angiogenesis Inhibitors; Animals; DNA; Doxorubicin; Flavonoids; Hep G2 Cells; Heparin, Low-Molecular-Weight; Hepatocytes; Humans; Intercellular Signaling Peptides and Proteins; Mice, Nude; Mitochondria; Nanoconjugates; Neoplasms; Peptides; Xenograft Model Antitumor Assays

To enhance the anticancer activity, tumor penetration ability of the hybrid anticancer peptide, in this study, a TAT (RKKRRQRRR) peptide modified kla peptide (KLAKLAKKLAKLAK, with all D-amino acids), named kla-TAT, was co-administrated with the homing/penetrating peptide iRGD which could enhance the permeability of chemical drug in solid tumor and tumor vessel by co-administration. In this study, the nonsmall cell lung cancer A549 cell line with the iRGD targeting receptor neuropilin-1 high expression was selected to establish the 2D monolayer cell, 3D multiple cell spheroids, and xenograft mice model. The co-administration of iRGD strengthened the permeability of kla-TAT peptide against A549 2D and 3D sphere model with the penetration improvement property of iRGD; more importantly, co-administration with iRGD dramatically enhanced the accumulation of kla-TAT peptide in tumor tissue on the xenograft mice model with the homing property of iRGD. The co-administration of iRGD strategy confers targeting ability to the hybrid peptide kla-TAT. We believe the chemical conjugation plus co-administration approach may provide a promising way for cancer treatment in clinical practices.

Topics: A549 Cells; Amino Acid Sequence; Animals; Cell Cycle Checkpoints; Cell Survival; Humans; Intercellular Signaling Peptides and Proteins; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasms; Neuropilin-1; Oligopeptides; Peptide Fragments; Peptides; Permeability; tat Gene Products, Human Immunodeficiency Virus; Transplantation, Heterologous

Several cationic antimicrobial peptides have been investigated as potential anti-cancer drugs due to their demonstrated selective toxicity towards cancer cells relative to normal cells. For example, intracellular delivery of KLA, a pro-apoptotic peptide, results in toxicity against a variety of cancer cell lines; however, the relatively low activity and small size lead to rapid renal excretion when applied in vivo, limiting its therapeutic potential. In this work, apoptotic peptide-polymer hybrid materials were developed to increase apoptotic peptide activity via multivalent display. Multivalent peptide materials were prepared with comb-like structure by RAFT copolymerization of peptide macromonomers with N-(2-hydroxypropyl) methacrylamide (HPMA). Polymers displayed a GKRK peptide sequence for targeting p32, a protein often overexpressed on the surface of cancer cells, either fused with or as a comonomer to a KLA macromonomer. In three tested cancer cell lines, apoptotic polymers were significantly more cytotoxic than free peptides as evidenced by an order of magnitude decrease in IC50 values for the polymers compared to free peptide. The uptake efficiency and intracellular trafficking of one polymer construct was determined by radiolabeling and subcellular fractionation. Despite their more potent cytotoxic profile, polymeric KLA constructs have poor cellular uptake efficiency (<1%). A significant fraction (20%) of internalized constructs localize with intact mitochondrial fractions. In an effort to increase cellular uptake, polymer amines were converted to guanidines by reaction with O-methylisourea. Guanidinylated polymers disrupted function of isolated mitochondria more than their lysine-based analogs, but overall toxicity was decreased, likely due to inefficient mitochondrial trafficking. Thus, while multivalent KLA polymers are more potent than KLA peptides, these materials can be substantially improved by designing next generation materials with improved cellular internalization and mitochondrial targeting efficiency.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carrier Proteins; Cell Survival; Chemistry, Pharmaceutical; Dose-Response Relationship, Drug; Drug Carriers; HeLa Cells; Humans; Inhibitory Concentration 50; Intercellular Signaling Peptides and Proteins; Ligands; Methacrylates; Mice; Mitochondrial Proteins; Neoplasms; Oligopeptides; Peptides; Polymerization; Technology, Pharmaceutical

The peptide KLA (acetyl-(KLAKLAK)2-NH2), which is rather non toxic for eukaryotic cell lines, becomes active when coupled to the cell penetrating peptide, penetratin (Pen), by a disulfide bridge. Remarkably, the conjugate KLA-Pen is cytotoxic, at low micromolar concentrations, against a panel of seven human tumor cell lines of various tissue origins, including cells resistant to conventional chemotherapy agents but not to normal human cell lines. Live microscopy on cells possessing fluorescent labeled mitochondria shows that in tumor cells, KLA-Pen had a strong impact on mitochondria tubular organization instantly resulting in their aggregation, while the unconjugated KLA and pen peptides had no effect. But, mitochondria in various normal cells were not affected by KLA-Pen. The interaction with membrane models of KLA-Pen, KLA and penetratin were studied using dynamic light scattering, calorimetry, plasmon resonance, circular dichroism and ATR-FTIR to unveil the mode of action of the conjugate. To understand the selectivity of the conjugate towards tumor cell lines and its action on mitochondria, lipid model systems composed of zwitterionic lipids were used as mimics of normal cell membranes and anionic lipids as mimics of tumor cell and mitochondria membrane. A very distinct mode of interaction with the two model systems was observed. KLA-Pen may exert its deleterious and selective action on cancer cells by the formation of pores with an oblique membrane orientation and establishment of important hydrophobic interactions. These results suggest that KLA-Pen could be a lead compound for the design of cancer therapeutics.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Calorimetry, Differential Scanning; Carrier Proteins; Cell-Penetrating Peptides; Circular Dichroism; Humans; Intercellular Signaling Peptides and Proteins; Liposomes; Membrane Lipids; Mitochondria; Mitochondrial Membranes; Neoplasms; Peptides; Spectroscopy, Fourier Transform Infrared; Tumor Cells, Cultured