C-Phycocyanin: Cellular targets, mechanisms of action and multi drug resistance in cancer.

C-Phycocyanin (C-PC) has been shown to be promising in cancer treatment; however, although several articles detailing this have been published, its main mechanisms of action and its cellular targets have not yet been defined, nor has a detailed exploration been conducted of its role in the resistance of cancer cells to chemotherapy, rendering clinical use impossible. From our extensive examination of the literature, we have determined as our main hypothesis that C-PC has no one specific target, but rather acts on the membrane, cytoplasm, and nucleus with diverse mechanisms of action. We highlight the cell targets with which C-PC interacts (the MDR1 gene, cytoskeleton proteins, and COX-2 enzyme) that make it capable of killing cells resistant to chemotherapy. We also propose future analyses of the interaction between C-PC and drug extrusion proteins, such as ABCB1 and ABCC1, using in silico and in vitro studies.

Production of Nanofibers Containing the Bioactive Compound C-Phycocyanin.

C-phycocyanin (C-PC) is a water-soluble phycobiliprotein present in light-harvesting antenna system of cyanobacteria. The nanostructures have not been widely evaluated, precluding improvements in stability and application of the C-PC. Electrospun nanofibers have an extremely high specific surface area due to their small diameter, they can be produced from a wide variety of polymers, and they are successfully evaluated to increase the efficacy of antitumor drugs. The incorporation of C-PC into nanofibers would allow investigations of potential uses in alternative cancer treatments and tissue engineering scaffolds. In this paper, C-phycocyanin were incorporated into the polymer polyethylene oxide (PEO) in various concentrations for nanofiber production via an electrospinning process. Nanofibers structures were analyzed using digital optical microscopy and scanning electron microscopy (SEM). Thermogravimetric analysis was performed on the pure starting compounds and the produced nanofibers. At a concentration of 2% (w/w) of PEO, nanofibers were not produced, and concentrations of 4% (w/w) of PEO failed to produce nanofibers of good quality. Solutions with 6% (w/w) PEO, 6% (w/w) PEO plus 1% (w/w) NaCI, and 8% (w/w) PEO promote the formation of bluish, homogeneous and bead-free nanofibers with average diameters varying between 542.1 and 759.9 nm, as evaluated by optical microscopy. SEM analysis showed that nanofibers produced from polymer solutions containing 6% (w/w) PEO, 1% (w/w) NaCl and 3% (w/w) C-PC have an average diameter of 295 nm. Thermogravimetric analysis detected an increase in thermal resistance with the incorporation of C-phycocyanin into nanofibers.