The multidrug resistance pumps are inhibited by silibinin and apoptosis induced in K562 and KCL22 leukemia cell lines.

Silibinin have been introduced for several years as a potent antioxidant in the field of nutraceuticals. Based on wide persuasive effects of this drug, we have decided to investigate the effects of silibinin on chronic myelogenous leukemia (CML) in vitro models, K562 and KCL22 cell lines. Lactate dehydrogenase (LDH) release, microculture tetrazolium test (MTT assay) and real-time PCR were employed to evaluate the effects of silibinin on cell cytotoxicity, cell proliferation and expression of various multidrug resistance genes in these cell lines, respectively. Our results have shown that presence of silibinin has inhibitory effects on cell proliferation of K562 and KCL22 cell lines. Also, our data indicated that silibinin, in a dose-dependent manner with applying no cytotoxic effects, inhibited cell proliferation and reduced mRNA expression levels of some transporter genes e.g. MDR1, MRP3, MRP2, MRP1, MRP5, MRP4, ABCG2, ABCB11, MRP6 and MRP7. The multifarious in vitro inhibitory effects of silibinin are in agreement with growing body of evidence that silibinin would be an efficient anticancer agent in order to be used in multi-target therapy to prevail the therapeutic hold backs against CML.

Use of siRNA in knocking down of dopamine receptors, a possible therapeutic option in neuropsychiatric disorders.

Heightened dopaminergic activity has been shown to be implicated in some major neuropsychiatric disorders such as schizophrenia. Use of dopaminergic antagonists was limited by some serious side effects related to unspecific blocking of dopamine receptors. Thus a target specific dopamine receptor gene silencing method such as using small interfering RNA (siRNA) might be useful. In this study recombinant plasmids expressing siRNA against dopamine receptors (D1-D5DRs) were produced, and their efficiency in knocking down of receptors in were assessed in rat neuroblastoma cell line (B65), using Real-time PCR method. Furthermore, D2DR siRNA expressing plasmid was injected into the rat nucleus accumbens bilaterally to investigate whether it can prevent the hyperactivity induced by apomorphine. Locomotion was measured in 10 min intervals, 50 min before and 60 min after apomorphine injection (0.5 mg/kg, S.C). Our results indicated that the mRNA level of dopamine receptors were reduced between 25 and 75% in B65 cells treated with the plasmids in vitro. In behavioral tests, locomotion was lower at least in the second 10 min after apomorphine injection in rats treated with plasmid expressing D2DR siRNA compare to control group [F (4,24) = 2.77, (P < 0.05)]. The spontaneous activity of treated rats was normal. In conclusion, dopamine receptors can be downregulated by use of siRNA expressing plasmids in nucleus accumbens. Although our work may have some possible clinical applications; the potentially therapeutic application of siRNA in knocking down of dopamine receptors needs further studies.

TGF-Beta codon 25 polymorphism and the risk of graft-versus-host disease after allogenic hematopoietic stem cell transplantation.

Some of the genotypes of cytokines are associated with acute graft versus host disease after bone marrow transplantation. The purpose of the present investigation was to find out the possible association between transforming growth factor beta-1 (TGF-beta1) codon 25 polymorphism (rs:1800471) and acute graft versus host disease (aGVHD) after bone marrow transplantation from the sibling with the similar HLA among the Iranian population. In this retrospective case-control investigation, 172 subjects including 86 Iranian patients and their siblings with the similar HLA as donor/recipient pairs were recruited. All of the patients were diagnosed with one group of blood disorder consisting of Acute Myeloid Leukemia (AML)=40, Acute Lymphoblastic Leukemia (ALL)=25 and Chronic Myeloid Leukemia (CML)=21. PCR-SSP method was carried out to ascertain TGF- beta1 codon 25 G/C polymorphism genotypes. The frequency of TGF- beta1 codon 25 GG, GC and CC genotypes among all cases were 77.3%, 21.5% and 1.2%, respectively. Recipients with the GG genotype developed severe aGVHD significantly more than those with CC or GC genotypes (Odds Ratio =12.133, P=0.015). Genetic background of TGF-beta1 may be involved in aGVHD development and/or severity in the patients who received Bone Marrow Transplantation (BMT) from their siblings with the similar HLA among the Iranian population.