Abstract
Introduction: Calotropis procera (Aiton) Dryand (Apocynaceae) is an herb that has been commonly used in folk medicine to treat various diseases for more than 1500 years.
Aims: Our goal was to investigate the anti-metastatic effects of phenolics extracted from C. procera (CphE) against 4T1 breast cancer cells and in BALB/c mice.
Methods: 4T1 cells were treated with CphE and quercetin (positive control) at concentrations that inhibited cell viability by 50% (IC50). Levels of reactive oxygen species (ROS), wound healing, and protein expressions were determined following standard protocols. For the in vivo pilot study, the syngeneic BALB/c mouse model was used. 4T1 cells were injected into mammary fat pads. Tumors were allowed to grow for 9 days before gavage treatment with CphE (150 mg GAE/kg/day) or PBS (controls) for one week. Excised tumors, liver, and lungs were analyzed for gene and protein expression and histology.
Results: In vitro results showed that CphE suppressed cell viability through apoptosis induction, via caspase-3 cleavage and total PARP reduction. CphE also scavenged ROS and suppressed Akt, mTOR, ERK1/2, CREB, and Src activation contributing to cell motility inhibition. CphE reduced IR, PTEN, TSC2, p70S6, and RPS6, protein levels, which are proteins involved in the PI3K/Akt/mTOR pathway, suggesting this pathway as CphE primary target. In vivo results showed downregulation of ERK1/2 activation by phosphorylation in tumor tissues, accompanied by angiogenesis reduction in tumor and lung tissues. A reduction of Cenpf mRNA levels in liver and lung tissues strongly suggested anti-invasive cancer activity of CphE.
Conclusion: CphE inhibited 4T1 cell signal pathways that play a key role in cell growth and invasion. The potential for in vitro results to be translated in vivo was confirmed. A complete animal study is a guarantee to confirm the CphE anticancer and antimetastatic activity in vivo.
Keywords: stage IV human breast cancer, milkweed (Calotropis procera), MAPK/ERK1/2, medicinal plants, angiogenesis, metastasis.
Graphical Abstract
[http://dx.doi.org/10.3322/caac.21660] [PMID: 33538338]
[PMID: 26380552]
[http://dx.doi.org/10.3389/fphar.2020.632079] [PMID: 33716731]
[http://dx.doi.org/10.1007/s00404-015-3859-y] [PMID: 26341644]
[http://dx.doi.org/10.1200/JOP.2017.022632] [PMID: 28489980]
[http://dx.doi.org/10.1016/j.cell.2018.03.041] [PMID: 29681456]
[http://dx.doi.org/10.1016/j.drudis.2019.09.001] [PMID: 31520748]
[http://dx.doi.org/10.1371/journal.pone.0098624] [PMID: 24878664]
[http://dx.doi.org/10.1186/bcr2927] [PMID: 21834963]
[http://dx.doi.org/10.1007/s10555-020-09881-y] [PMID: 32399646]
[http://dx.doi.org/10.1016/j.phrs.2020.104806] [PMID: 32294525]
[http://dx.doi.org/10.1177/1947601913507951] [PMID: 24349632]
[http://dx.doi.org/10.1007/s10549-016-3967-9] [PMID: 27592113]
[http://dx.doi.org/10.1016/j.canlet.2019.05.025] [PMID: 31128213]
[http://dx.doi.org/10.1186/s13058-019-1125-0] [PMID: 30845991]
[http://dx.doi.org/10.2147/OTT.S6909] [PMID: 20616959]
[http://dx.doi.org/10.1016/j.biopha.2017.11.134] [PMID: 29198744]
[http://dx.doi.org/10.1155/2018/8324696] [PMID: 29681985]
[http://dx.doi.org/10.1016/j.bcp.2007.02.014] [PMID: 17382300]
[http://dx.doi.org/10.12989/cac.2006.3.1.017]
[http://dx.doi.org/10.1155/2017/8086791] [PMID: 28951762]
[http://dx.doi.org/10.3109/13880200903490513] [PMID: 20690894]
[http://dx.doi.org/10.1155/2013/615454] [PMID: 24348174]
[http://dx.doi.org/10.3923/jms.2013.269.275]
[http://dx.doi.org/10.1080/10286020.2015.1040772] [PMID: 25971597]
[http://dx.doi.org/10.1515/znc-2011-11-1203] [PMID: 22351979]
[http://dx.doi.org/10.1371/journal.pone.0048514] [PMID: 23284617]
[http://dx.doi.org/10.1046/j.1365-2621.2002.00552.x]
[http://dx.doi.org/10.1021/jf201056x] [PMID: 21682256]
[http://dx.doi.org/10.1021/jm049405a] [PMID: 15689169]
[http://dx.doi.org/10.1016/j.bcp.2009.01.018] [PMID: 19447218]
[http://dx.doi.org/10.3390/medicina55040114] [PMID: 31013662]
[http://dx.doi.org/10.1021/jf900259m] [PMID: 19530711]
[http://dx.doi.org/10.3390/biom9110735] [PMID: 31766246]
[http://dx.doi.org/10.3109/10715761003667554] [PMID: 20370557]
[http://dx.doi.org/10.1002/jcb.21977] [PMID: 19009557]
[http://dx.doi.org/10.4236/jbpc.2012.32018]
[http://dx.doi.org/10.1080/01926230701320337] [PMID: 17562483]
[http://dx.doi.org/10.1016/j.rvsc.2021.06.005] [PMID: 34119813]
[http://dx.doi.org/10.3748/wjg.v12.i16.2517] [PMID: 16688796]
[http://dx.doi.org/10.1111/cpr.12017] [PMID: 23510470]
[http://dx.doi.org/10.1093/annonc/mdz133] [PMID: 31050709]
[http://dx.doi.org/10.1038/s41598-020-63310-2] [PMID: 32286420]
[http://dx.doi.org/10.1158/1078-0432.CCR-08-1137] [PMID: 19351775]
[http://dx.doi.org/10.1155/2020/9258396] [PMID: 32211045]
[http://dx.doi.org/10.1126/sciadv.aaw9960] [PMID: 32128390]
[http://dx.doi.org/10.1016/S0898-6568(01)00271-6] [PMID: 11882383]
[http://dx.doi.org/10.1111/cpr.12451] [PMID: 29484762]
[http://dx.doi.org/10.3389/fendo.2011.00093] [PMID: 22654833]
[http://dx.doi.org/10.1016/j.ejca.2005.03.023] [PMID: 15951164]
[http://dx.doi.org/10.1002/mc.22538] [PMID: 27533114]
[http://dx.doi.org/10.3390/ijms20102505] [PMID: 31117237]
[http://dx.doi.org/10.4161/cc.8.8.8147] [PMID: 19282669]
[http://dx.doi.org/10.18632/oncotarget.18264] [PMID: 28903453]
[http://dx.doi.org/10.3390/ijms20133177] [PMID: 31261749]
[http://dx.doi.org/10.1016/j.lfs.2016.05.036] [PMID: 27245276]
[http://dx.doi.org/10.1080/2162402X.2017.1316437] [PMID: 28680747]
[http://dx.doi.org/10.1186/s12967-015-0425-0] [PMID: 25885919]