The Experimental and Clinical Study on the Effect of Curcumin on Cell Cycle Proteins and Regulating Proteins of Apoptosis in Acute Myelogenous Leukemia

To investigate whether the Bcl- 2 gene family is involved in m odulating mechanism of apoptosis and change of cell cycle protein induced by curcumin in acute myeloid leukemia HL - 6 0 cell line and primary acute m yelogenous leukem ic cells,the Bcl- 2 family member Mcl- 1,Bax and Bak and cell cycle proteins including P2 7kipl,P2 1wafl,cyclin D3and p Rbp- were selected and their ex- pression detected by SABC imm uno- histochem ical stain m ethod.The attitude of sub- G1 peak in DNA histogram was determined by FCM.The TU NEL positive cell percentage was identified by term inal deoxynucleotidyl transferase (Td T ) - m ediated Biotin d U NP end labeling technique.It was found that when HL - 6 0 cells were treated with 2 5μm ol/ L curcumin for 2 4 h,the expression level of Mcl- 1was down- regulated,but that of Bax and Bak up- regulated time- dependently.There was significant difference in the expression level of Mcl- 1,Bax and Bak between the curcumin- treated groups and control group(P<0 .0 5 - 0 .0 1) .At the sam e time,curcumin had no effect on progress of cell cycle in prim aty acute m yelogenous leukemia at newly diagnosis,but could in- crease the peak of Sub- G1 (P<0 .0 5 ) ,and down- regulate the expression of Mcl- 1and up- regulate the expression of Bax and Bak with the difference being statistically significant.The expression of P2 7kipl,P2 1wafl and p Rbp- were elevated and thatof cyclin D3decreased in the presence of curcum in. These findings suggested thatthe Bcl- 2 gene fam ily indeed participated in the regulatory process of apoptosis induced by curcumin in HL - 6 0 cells and AML cells.Curcumin can induce apoptosis of primary acute myelogenous leukemic cells and disturb cell cycle progression of HL - 6 0 cells.The m echanism appeared to be m ediated by perturbing G0 / G1 phases checkpoints which associated with up- regulation of P2 7kipl,P2 1wafl and p Rbp- expression,and down- regulation of cyclin D3.

Effects of estradiol on cell cycle and cyclin proteins of vascular smooth muscle cells in rats

To study the effects of 17β-estradiol(E2) on the growth of cultured rat vascular smooth muscle cells (VSMC).Methods The cell cycle and the expressions of Cyclin D1 and CDK4 proteins were examined by flow cytometry in VSMC cultured in different concentrations (0～100 nmol/L) of 17β-estradiol with or without serum.Results Under serum-stimulating conditions,17β-estradiol(1,10,100 nmol/L) promoted VSMC proliferation by accelerating their cell cycle progression from G1 to S phases,and the cell rates at S were (31.89±9.14)%(35.90±4.59)% and (30.77±1.20)% respectively,significantly higher than the corresponding values of control cells (21.63±1.80)%.This was accompanied by the significantly increased expression of Cyclin D1 and CDK4 proteins.In the cultures without serum,however,high concentrations (10,100 nmol/L) of E2 induced a cell cycle arrest at G1 phase,which was characterizsed by decreased cell rates at S phase [(9.93±1.43)% and (8.76±1.80)% respectively,P<0.05] as compared with the corresponding control values and a down-regulation of expressions of Cyclin D1 and CDK4 proteins.Conclusion E2 can either promote or inhibit VSMC proliferation depending upon the presence or absence of serum mitogens.The underlying mechanism may be associated with the hormone’s action on the expression of Cyclin D1 and CDK4 which act as the G1 phase regulators.4 refs.

Expression of CDC42 in cervical squamous cell carcinoma and its correlation with clinicopathologic characteristics

Objective： The high expression of cell division cycle 42 protein （CDC42） may be involved in the occurrence and progression of several tumors. However, the expression and function of CDC42 in cervical squamous cell carcinoma remains unclear. This study aimed to investigate the expression of CDC42 in cervical squamous cell carcinoma and its correlation with clinicopathologic characteristics. Methods： The expression of CDC42 in 162 cervical squamous cell carcinoma tissue samples and 33 normal cervical tissue samples was investigated by immunohistochemistry. The CDC42 mRNA expression was detected by reverse transcription-polymerase chain reaction （RT-PCR）. Results： The cervical squamous cell carcinoma group showed a significantly higher CDC42 positive rate, compared to the normal cervical tissues （P〈0.05）. Fttrthermore, the tissues of stage Ⅱ-Ⅳ carcinoma patients showed higher CDC42 expression levels compared to stage I patients （P=0.05）. In addition, the expression of CDC42 was not correlated to age of patients, differentiation degree of cancer cells, or lymph node metastasis （P〉0.05）. Furthermore, compare with normal cervical tissues, the CDC42 mRNA expression in cervical cancer had no significant difference. Conclusions： CDC42 was up-regulated at protein level, but not mRNA level, in cervical squamous cell carcinoma. The high expression of CDC42 was correlated to the clinical stage of the patients, indicating that CDC42 might contribute to the progression of cervical squamous cell carcinoma.

Effect of Exogenous bFGF on the Proliferation of Human Adenoid Cystic Carcinoma ACC-2 Cells

To observe the effects of basic fibroblast growth factor （bFGF） on human adenoid cystic carcinoma ACC-2 cell line proliferation and ERK, cyclin D1/p21^waf/cip1 signaling pathways, human adenoid cystic carcinoma cells （ACC-2） were cultured and the influence of bFGF of different concentrations on cell proliferation was determined by MTT. Protein was detected by immuno-precipitation and ERK activity by using ERK agent kit. p-ERK1/2 and down-stream cyclin D1, p21^waf/cip1 expression were detected by Western blotting and the interfering role of mitogen protein-activated kinase （MEK） suppressor U0126 in the afore-mentioned indicators was examined. MTT demonstrated ACC-2 cell proliferation was substantially enhanced by bFGF, immuo-precipitation displayed ERK activity was up-regulated by bFGF, and immuno-imprinting also showed p-ERK1/2, cyclin D1 expression was greatly enhanced and p21^waf/cip1 expression was inhibited by bFGE U0126 suppressed the effect of bFGF. It is concluded that bFGF can promote the proliferation of human adenoid cystic carcinoma ACC-2 cells, and its pathways are associated with the up-regulated activity and expression of p-ERK1/2, inhibited p21waf/cip1 expression and enhanced cyclin D1 expression.

Qufeng Tongluo Prescription(祛风通络方)Inhibits Mesangial Cell Proliferation and Promotes Apoptosis through Regulating Cell Cycle Progression

Objective： To study the effects and possible underlying mechanism of Qufeng Tongluo Prescription （祛风通络方, QFTL） on the regulation of mesangial cells （MCs） proliferation and apoptosis. Methods： The MCs used in this experiment have undergone five passages induced by lipopolysaccharide （LPS）. Changes in the proliferation, apoptosis, cell cycle regulatory proteins and mRNA expression levels of the MCs after administration of Benazepril or QFTL were measured by methyl thiazolyl tetrazolium （MTT） reduction assay, flow cytometry, Western blot and quantitative real-time polymerase chain reaction （qRT-PCR）, respectively. Results： The addition of Benazepril or QFTL serum inhibited LPS-induced MC proliferation after treatment for 24, 48 and 72 h, respectively （P〈0.05 or P〈0.01）. Moreover, the inhibitory effect is more significant in the QFTL group at 48 h （P〈0.05）. Compared with the control group, LPS-induced cell proliferation decreased the number of cells in G1 phase versus cells in S and G2/M phases, while the addition of QFTL and Benazepril serum increased the ratio of cells at G1 phase （P〈0.05 or P〈0.01） to cells at S phase （P〈0.01）, implicating the cell cycle inhibition effect exerted by QFTL. LPS decreased the level of MC apoptosis, compared with the control group （P〈0.05）, while QFTL and Benazepril serum increased the level of MC apoptosis （P〈0.01）. Moreover, the difference between the QFTL group and the Benazepril group was statistically significant （P〈0.01）. Compared with the control group, the protein and mRNA expression levels of cylinD1, cyclin dependent kinase 2 （CDK2） and p21 were significantly increased （P〈0.05 or P〈0.01）, p27 was decreased but with no statistical significance （P〉0.05）; After being treated with QFTL and Benazepril serum, the protein and mRNA expression levels of cylinD1, CDK2, p21 were decreased and p27 increased significantly （P〈0.05 or P〈0.01）; Compared with the Benazepril group, QFTL show better effects on protein and mRNA expression levels of cylinD1, CDK2 （P〈0.05 or P〈0.01） and p21 protein expression （P〈0.05）. Conclusion： QFTL inhibits MCs proliferation, promotes MCs apoptosis through an underlying mechanism of down-regulating the protein and mRNA expression levels of cylinD1, CDK2, p21 and up-regulation of the expression level of p27.

Effects of insulin-like growth factor binding protein 7 on cell cycle and proliferation of gastric cancer in vitro and in vivo

Objective To investigate the effects of insulin-like growth factor binding protein 7(IGFBP7)on the proliferation,cell cycle of gastric cancer cell and the expression of cynlin D1,cyclin-dependent kinase(CDK)4,and to observe the effects of IGFBP7 on the growth of gastric tumor xenografts in nude mice.Methods The MKN-28cell line was interfered by small interfere ribonucleic acid(siRNA)(interfered group),and blank control group,