Sclerotium rolfsii lectin inhibits proliferation and induces apoptosis in human ovarian cancer cell line PA-1.
OBJECTIVE
Sclerotium rolfsii lectin (SRL), isolated from soil born phytopathogenic fungus Sclerotium rolfsii, exhibits exquisite binding specificity to the oncofoetal Thomsen-Friedenreich (Galβ1,3GalNAcα-O-Ser/Thr, T or TF) antigen and associated glycans. In the present study, we report anti-proliferative activity of SRL and investigate underlying mechanisms of SRL-induced apoptosis, in the human ovarian cancer cell line PA-1.


METHODS
SRL-induced anti-proliferative effects were determined using MTT assay and induction of apoptosis was determined by flow cytometry, confocal microscopy and western blot analysis.


RESULTS
SRL inhibited population growth of PA-1 cells in a dose- and time-dependent manner with maximum inhibition (71.3 ± 1.9%) occurring at concentration of 50 μg/ml after 72 h incubation. Observed effects of SRL could be blocked by competing glycoproteins, asialomucin, mucin and fetuin. Treatment with SRL resulted in increase in hypodiploid cell population as determine by cell cycle analysis. Increase in numbers of annexin V-PI positive cells, and cleavage of PARP confirmed apoptosis-inducing activity of SRL. Involvement of caspases in SRL-mediated apoptosis was determined by cleavage of caspases-3, -8 and -9 in a time-dependent manner, thereby suggesting possible involvement of both intrinsic and extrinsic caspase-dependent pathways.


CONCLUSIONS
The present study demonstrates anti-proliferative and apoptosis-inducing activity of SRL that can be exploited for potential application in ovarian cancer research.
Department of Studies in Biochemistry, Karnatak University, Dharwad, India.
S M
SM
Eligar
R
R
Pujari
B M
BM
Swamy
P
P
Shastry
S R
SR
Inamdar
D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D001203:Ascomycota / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D005260:Female; D006801:Humans; D037102:Lectins / Q000378:metabolism / Q000494:pharmacology*; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology
D015295:Antigens, Tumor-Associated, Carbohydrate; D037102:Lectins; C016467:Thomsen-Friedenreich antigen