Study On The Anti-tumor Activity And Mechanism Of Tanshinone ?A In Granulocytic Leukemia

Salvia miltiorrhiza is a commonly used Chinese medicine in the genus Salvia of the Labiatae family.It is often used clinically for the treatment of cardiovascular and cerebrovascular diseases.Fat-soluble tanshinones and water-soluble salvianolic acids are the main active ingredients in Salvia miltiorrhiza.Salvia miltiorrhiza,as a traditional Chinese medicine in China,has been used in clinical practice for more than 2000 years,it has a wide range of biological activities and little toxic and side effects.In early research,research on the active ingredients of Salvia Miltiorrhiza mainly focused on tanshinones.Tanshinone is an ether or ethanol extract from the root of Salvia Miltiorrhiza,and is the main fat-soluble component of Salvia Miltiorrhiza.According to its chemical structure,it is mainly divided into four kinds: tanshinone ?A,tanshinone I,dihydrotanshinone,and cryptotanshinone,all of which are diterpene quinone compounds of orthoquinone type.Each tanshinone has its specific pharmacological effect.Leukemia is a heterogeneous group of diseases caused by chromosomal rearrangements,multiple gene mutations,and abnormal epigenetic regulation.Chronic myelogenous leukemia(CML)is one of the types of leukemia and is a malignant myeloproliferative disease.CML is one of the earliest cancers that are clearly associated with genetic damage,the Philadelphia chromosome,which produces the chimeric BCR/ABL protein.The cloned disease,which is characterized by the Philadelphia chromosome,is characterized by the proliferation of myeloid leukemia cells in the bone marrow,accounting for about 15% of newly diagnosed adult leukemia cases(3 cases).Although significant advances have been made in the clinical treatment of leukemia over the past few decades,the development of CML is very complicated,involving gene mutations,chromosomal mutations and epigenetic regulation of genes.The therapeutic effect is modest,the prognosis is poor,and the pathogenesis is unclear.There are still problems with its treatment.Therefore,it is important to elucidate the key mechanisms of CML in order to develop effective therapeutic strategies.The purpose of this study was to explore the antitumor activity of tanshinone ?A in leukemia and to provide a new therapeutic strategy for the clinical treatment of leukemia.We tested the effect of tanshinone ?A on the cell viability of 13 human leukemia cell lines in our laboratory cell bank using MTT method,the results showed that tanshinone ?A inhibited the proliferation of 6 leukemia cell lines(HL-60,K562,KG-1a,THP-1,U937,RS4:11)in a dose-dependent manner,while the proliferation of 7 other leukemia cell lines(CCRF-CEM,Jurkat,Kopn-8,Molm-13,ML-2,NB4/BF,MM6)was not significantly inhibited.Subsequently,the effects of tanshinone ?A combined with the chemotherapy drugs Cytosine arabinoside and Doxorubicin on the cell activity of six leukemia cell lines(HL-60,K562,KG-1a,THP-1,U937,RS4:11)that were sensitive to tanshinone ?A were examined,the results showed that tanshinone ?A combined with chemotherapy could significantly inhibited the proliferation and the clonal formation of K562 cells.Next,we investigated whether the inhibition of K562 cell proliferation by tanshinone ?A was related to the induction of apoptosis in K562 cells and whether it affected the cell cycle distribution by flow cytometry.It was found that tanshinone ?A could induced K562 cell apoptosis,but did not affect the change of K562 cell cycle.Giemsa staining showed that tanshinone ?A induced the changes related to apoptosis of K562 cells.In order to further investigate the mechanism of tanshentone ?A-induced apoptosis in K562 cells,we examined the changes in mitochondrial membrane potential and expression levels of related proteins(PARP,Caspase-3,Caspase-8,Caspase-9,APAF1,Cyt-c,Bax,Bcl-2,Bcl-XL,Bad)in K562 cells by flow cytometry and Western blot.The results showed that tanshinone ?A could decreased the mitochondrial membrane potential of K562 cells,reduced the expression levels of anti-apoptotic proteins Bcl-2 and Bcl-XL,increased the expression of pro-apoptotic proteins Bax and Bad,and release Cyt-c into the cytoplasm to activate Caspase-3 and Caspase-9,which leads to the cleavage of poly-ADP ribose polymerase(PARP),and ultimately leads to cell apoptosis.To investigate the anti-tumor efficacy of tanshinone ?A in vivo,we constructed a NOD/SCID mouse model of K562 cell xenotransplantation,intraperitoneal administration of tanshinone ?A(50 mg/kg),and detected the tumor tissue weight and the morphology and size of the liver and spleen of the mice after 14 days.And found that tanshinone ?A(50 mg/kg)could significantly inhibited the growth of K562 tumors.In summary,our study first reported the antitumor activity of tanshinone ?A in myelogenous leukemia through in vitro and in vivo experiments,and preliminarily explored its antitumor mechanism.These studies provide a theoretical basis for the clinical treatment of leukemia with tanshinone ?A.