Phycocyanin Induces Apoptosis and Enhances the Effect of Topotecan on Prostate Cell Line LNCaP

Abstract

C-phycocyanin (C-PC) from Spirulina has been previously shown to have anticancer properties. Here, we report on anticancer activity of C-PC that was isolated from the novel cyanobacterium Limnothrix sp. 37-2-1. C-PC from this organism exhibited anticancer properties in our in vitro systems; however, the required doses were well above the range of anticancer drugs normally used. Therefore, we conducted several experiments to test whether lower-than-usual doses of the anticancer drug topotecan (TPT) can offer the same level of cytotoxic effects as normal doses when combined with C-PC. For this purpose, cytotoxicities of C-PC and TPT were tested using the LNCaP (prostate cancer) cells. We found that when only 10% of a typical dose of TPT was combined with C-PC, the cancer cells were killed at a higher rate than when TPT was used alone at full dose. Similarly, we were also able to detect an increased level of radical oxygen species (ROS) generation as well as an increase in activities of caspase-9 and caspase-3 when these two compounds were used in combination. Taken together, our findings suggest that combining C-PC from Limnothrix sp. with the lower dose of TPT can induce apoptosis through generation of ROS and activation of caspases. In that respect, we suggest that C-PC can potentially improve the efficacy of the currently available anticancer drug, and therefore diminish its harsh side effects in the patient.

Antitumor activity of C-phycocyanin from Arthronema africanum (Cyanophyceae)

“…In contrast to the C-PC of S. platensis, the C-PC from the cyanobacterium Limnothrix sp. exhibited low activity (Gantar et al 2012). When combined with low dose of the anticancer drug topotecan, however, the C-PC from Limnothrix sp.…”

“…significantly improved the topotecan efficacy. In combination, these two compounds induced apoptosis in the LNCaP (prostate cancer) cells through the generation of ROS and activation of caspases (Gantar et al 2012). The other studied phycocyanins, those of the red algae Porphyra haitanensis (Liu et al 2000a) and P. yezoensis (Zhang et al 2011) significantly inhibited the growth of human leukemia HL-60 cells, and Hep-2 (laryngeal carcinoma) and A375 (malignant melanoma) cell lines, respectively by the unidentified pathways.…”

“…The investigations on antitumor activity have been focused on the C-PC from Spirulina platensis, while the other rich sources of this valuable pigment remain unexplored, except for Limnothrix sp. (Gantar et al 2012), Porphyra yezoensis (Zhang et al 2011) and Porphyra haitanensis (Liu et al 2000a). Remarkably, the tested phycocyanins differed in their potential and mechanisms of action, which could be due to their different molecular weights and the specificity of the used experimental models.…”

Anti-tumor effect of C-phycocyanin from Anabaena sp.ISC55 in inbred BALB/c mice injected with 4T1 breast cancer cell

“…C-phycocyanin (C-PC) could induce apoptosis on prostate cell line LNCaP. Use of the C-PC-TPT combination can reduce the effective dose of TPT and still maintain its efficacy in inducing significant apoptotic cell death in LNCaP cells (Gantar et al 2012). Anti-inflammatory and c Graph 4 Elston grade of nuclear pleomorphism in the control and treatment groups (mean ± SD).…”

Microalgal Rainbow Colours for Nutraceutical and Pharmaceutical Applications

“…It was observed that as little as a 50 μM dose decreased the proliferation of K562 cells by 49 % for 48 h (Subhashini et al 2004 ). Also, C-PC induced apoptosis in prostate cancer (LNCaP) cell line by diminishing the required dosage of topotecan, an anticancer medication which frequently causes adverse side reactions in patients (Gantar et al 2012 ). In another study involving human hepatoma cell line (HepG2), C-PC led to a reduction in the proliferation of the cells with the highest reduction observed at a concentration of 7 μg/ml C-PC along with a loss of nuclear entities due to fragmentation (Basha et al 2008 ).…”