Apoptotic events induced by a natural plastoquinone from the marine alga Desmarestia menziesii in lymphoid neoplasms
Authors: Iris Mattos Santos-Pirath
Paulo Antunes Horta
Ana Cláudia Philippus
Miriam De Barcellos Falkenberg
Gabriele Andressa Zatelli
Pio Colepicolo
Laura Otto Walter
Maria Cláudia Santos-Silva
Mariana Franzoni Maioral
Journal: Experimental Hematology (2020)
Discipline: CLINICAL MEDICINE
Keywords: new drugs; lymphoid neoplasms; marine plastoquinone; cytotoxic effect; mechanism
Affiliations: Experimental Oncology and Hemopathics Laboratory, Clinical Analysis Department, Federal University of Santa Catarina, Florianópolis, SC, Brazil; Post-graduation Program in Pharmaceutical Sciences, Health Sciences Center, Federal University of Santa Catarina, Florianópolis, SC, Brazil., Post-graduation Program in Pharmaceutical Sciences, Health Sciences Center, Federal University of Santa Catarina, Florianópolis, SC, Brazil; Research Group of Natural and Synthetic Marine Products, Department of Pharmaceutical Sciences, Federal University of Santa Catarina, Florianópolis, SC, Brazil., Post-graduation Program in Pharmaceutical Sciences, Health Sciences Center, Federal University of Santa Catarina, Florianópolis, SC, Brazil., Research Group of Natural and Synthetic Marine Products, Department of Pharmaceutical Sciences, Federal University of Santa Catarina, Florianópolis, SC, Brazil., Department of Chemistry, University of São Paulo, São Paulo, SP, Brazil., Experimental Oncology and Hemopathics Laboratory, Clinical Analysis Department, Federal University of Santa Catarina, Florianópolis, SC, Brazil; Post-graduation Program in Pharmaceutical Sciences, Health Sciences Center, Federal University of Santa Catarina, Florianópolis, SC, Brazil. Electronic address: .

Abstract:  There exists an urgent need for the development of new drugs for the treatment of lymphoid neoplasms. The aim of this study was to evaluate the cytotoxic effect of the marine plastoquinone 9'-hydroxysargaquinone (9'-HSQ), focusing on investigation of the mechanism by which it causes death in lymphoid neoplastic cells. This particular plastoquinone reduced the cell viability of different hematological tumor cell lines in a time-dependent and concentration-dependent manner. Intrinsic apoptosis occurred with time-dependent reduction of mitochondrial membrane potential (42.3 ± 1.1% of Daudi cells and 18.6 ± 5.6% of Jurkat cells maintained mitochondrial membrane integrity) and apoptosis-inducing factor release (Daudi: 133.3 ± 8.1%, Jurkat: 125.7 ± 6.9%). Extrinsic apoptosis also occurred, as reflected by increased FasR expression (Daudi: 139.5 ± 7.1%, Jurkat: 126.0 ± 1.0%). Decreases were observed in the expression of Ki-67 proliferation marker (Daudi: 67.5 ± 2.5%, Jurkat: 84.3 ± 3.8%), survivin (Daudi: 66.0 ± 9.9%, Jurkat: 63.1 ± 6.0%), and NF-κB (0.7 ± 0.04% in Jurkat cells). Finally, 9'-HSQ was cytotoxic to neoplastic cells from patients with different lymphoid neoplasms (IC50: 4.9 ± 0.6 to 34.2 ± 0.4 µmol/L). These results provide new information on the apoptotic mechanisms of 9'-HSQ and suggest that it might be a promising alternative for the treatment of lymphoid neoplasms. 

Retracted: No

PubPeer comments:
 Concern about Figure 3C. Image made a bit lighter to bring out background. * Unexpected rectangular areas of pitch black blocks suggesting image modification * Boxes of the same color highlight cells that look remarkably similar. * The left two control images also appear in IM Santos-Pirath et al., Hematology Oncology and Stem Cell Therapy (2021), doi: 10.1016 j.hemonc.2020.07.007 - https: pubpeer.com publications 668EC6986F601FCBAADA2C10DF278A ![file] ![file] , 
 The Control lanes in the Western blots of this paper also look remarkably similar to those in DOI: 10.1016 j.hemonc.2020.07.007, suggesting that lanes shown next to each other might not have run adjacent to each other in the original blot. This makes it hard to compare thickness and sizes of bands. Could the authors please show the original, uncropped blots? ![file] ,