The novel therapeutic potential of bovine α-lactalbumin made lethal to tumour cells (BALMET) and oleic acid in oral squamous cell carcinoma (OSCC).

BACKGROUND: Since the serendipitous discovery of bovine α-lactalbumin made lethal to tumour cells (BAMLET)/human α-lactalbumin made lethal to tumour cells there has been an increased interest in the ability of the two components, oleic acid and α-lactalbumin, to form anti-cancer complexes. Here we have investigated the in-vitro efficacy of the BAMLET complex in killing oral cancer (OC) cells, determined the active component of the complex and investigated possible biological mechanisms. MATERIALS AND METHODS: Two OC cell lines (±p53 mutation) and one dysplastic cell line were used as a model of progressive oral carcinogenesis. We performed cell viability assays with increasing BAMLET concentrations to determine the cytotoxic potential of the complex. We further analysed the individual components to determine their respective cytotoxicities. siRNA knockdown of p53 was used to determine its functional role in mediating sensitivity to BAMLET. Cell death mechanisms were investigated by flow cytometry, confocal microscopy and the lactate dehydrogenase assay. RESULTS: Our results show that BAMLET is cytotoxic to the OC and dysplastic cell lines in a time and dose-dependent manner. The cytotoxic component was found to be oleic acid, which, can induce cytotoxicity even when not in complex. Our results indicate that the mechanism of cytotoxicity occurs through multiple simultaneous events including cell cycle arrest, autophagy like processes with a minor involvement of necrosis. CONCLUSION: Deciphering the mechanism of cytotoxicity will aid treatment modalities for OC. This study highlights the potential of BAMLET as a novel therapeutic strategy in oral dysplastic and cancerous cells.

Photo-CIDNP NMR methods for studying protein folding.

Chemically induced dynamic nuclear polarization (CIDNP) is a nuclear magnetic resonance phenomenon that can be used to probe the solvent-accessibility of tryptophan, tyrosine, and histidine residues in proteins by means of laser-induced photochemical reactions, resulting in significant enhancement of NMR signals. CIDNP offers good sensitivity as a surface probe of protein structure and is particularly powerful in time-resolved NMR measurements. Real-time, rapid-injection protein refolding experiments permit the observation of changes in the accessibility of specific residues during the folding process. CIDNP pulse-labeling gives information on the accessibility of residues in partially structured proteins (e.g., molten globule states) whose NMR spectra are broad and poorly resolved. Heteronuclear two-dimensional (15)N-(1)H CIDNP techniques allow identification of surface-accessible residues with improved resolution and sensitivity. These methods offer residue-specific structural and kinetic information on transient folding intermediates and other partially folded states of proteins that are not readily available from more routine NMR techniques.