Targeting polyamine biosynthetic pathway through RNAi causes the abrogation of MCF 7 breast cancer cell line.
The diamine putrescine and polyamines, spermidine (triamine) and spermine (tetraamine) are small organic polycations that play an indispensable role in key cellular processes such as the regulation of growth, differentiation, and macromolecular functions. Elevated levels of polyamines (PAs) have been shown to be one of the major factors involved in carcinogenesis. In this study, specific silencing of the expression of three genes of PA biosynthesis pathway, ornithine decarboxylase (ODC), S-adenosylmethionine decarboxylase (SAMDC), and spermidine synthase (SPDSYN) was achieved using RNA interference in MCF 7 breast cancer cell line. For optimizing the effective small interfering nucleic acid (siNA), three variants of ODC siNA [siRNA, locked nucleic acid (LNA)-modified siRNA, and siHybrid (RNA and DNA hybrid)] were used and a dose- and time-dependent study was conducted. The PA biosynthetic genes were targeted individually and in combination. RNAi-mediated reduction in the expression of PA biosynthesis genes resulted in distorted cell morphology, reduced cancer cell viability, and migration characteristic. The most promising results were observed with the combined treatment of siSPDSYN and siODC with 83 % cell growth inhibition. On analyzing the messenger RNA (mRNA) expression profile of the cell cycle and apoptosis-related genes, it was observed that RNAi against PA biosynthetic genes downregulated the expression of CDK8, CCNE2, CCNH, CCNT1, CCNT2, CCNF, PCNA, CCND1, and CDK2, and upregulated the expression of E2F4, BAX, FAS, TP53, CDKN1A, BAK1, CDKN1B, ATM, GRANB, and ATR genes when compared with control-transfected cells. These results suggest that the targeting polyamine biosynthesis through RNAi approach could be a promising strategy for breast cancer therapy and might be extended for therapy of other cancers.
Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
Enna Dogra
ED
Gupta
Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
Manendra
M
Pachauri
Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
Prahlad Chandra
PC
Ghosh
Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. rajam.mv@gmail.com.
Manchikatla Venkat
MV
Rajam
D012437:Adenosylmethionine Decarboxylase / Q000378:metabolism; D017209:Apoptosis; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002455:Cell Division; D002465:Cell Movement; D049109:Cell Proliferation; D002470:Cell Survival; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D061986:MCF-7 Cells; D009955:Ornithine Decarboxylase / Q000378:metabolism; D011073:Polyamines / Q000737:chemistry*; D011700:Putrescine / Q000096:biosynthesis; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D013095:Spermidine / Q000096:biosynthesis; D011436:Spermidine Synthase / Q000378:metabolism; D013096:Spermine / Q000096:biosynthesis
D011073:Polyamines; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D013096:Spermine; D011436:Spermidine Synthase; D009955:Ornithine Decarboxylase; D012437:Adenosylmethionine Decarboxylase; D013095:Spermidine; D011700:Putrescine
Cancer; Cell division; Polyamine biosynthesis genes; Polyamines; RNA interference