Expression of Runt-related Transcription Factor 3 in Human Colon Cancer Cell Line HCT-116 Resistant to 5-Fluorouracil and the Mechanism of Drug Resistance / 中国医学科学院学报

Objective To establish a human colon cancer cell line HCT-116/5-FU resistant to 5-fluorouracil(5-FU)and explore the relationship between runt-related transcription factor 3(RUNX3)and drug resistance of colorectal cancer.Methods The human colon cancer cell line HCT-116/5-FU with resistance to 5-FU was established by low concentration gradient increment combined with high-dose intermittent shock.CCK-8 method was used to determine the half maximal inhibitory concentration(IC

Study on the aging of leukemia K562 cells induced by ginsenoside Rg1 / 医学研究生学报

Objective　At present, the main studies of ginsenoside Rg1 are almost on the field of solid tumors and acute leukemias, and few on chronic leukemias. We aims to figure out the role of ATR-Chk1 pathway on cell aging in ginsenoside Rg1-treated leukemia K562 cells.　Methods　K562 cells were treated with ginsenoside Rg1 at different concentrations and divided into a control group (with 50 μL PBS culture solution) and 5 μmol/L ginsenoside group, 10 μmol/L ginsenoside group, 20 μmol/L ginsenoside group, 40 μmol/L ginsenoside group, 80 μmol/L ginsenoside group. CCK-8 assay，colony formation assay and flow cytometry for cell cycle detection were used to determine the effect of ginsenoside Rg1 on the aging of K562 cells. SA-β-Gal staining and Wright’s staining were used to observe the morphological changes of K562 cells’ aging. Real-time quantitative PCR and Western blot were used to detect the changes of ATR and Chk1 expression.　Results　The colony formation rate of K562 cells in the 20 μmol/L ginsenoside group was significantly lower than that in the other groups (P<0.05). CCK-8 test results showed that K562 cell proliferation of ginsenoside Rg1 induced groups was higher than that of the control group at 24, 48, and 72 hours (P<0.05). K562 cell proliferation inhibition rate was the highest in 20 μmol/L ginsenoside group for 48 hours treatment (P<0.05). The rate of SA-β-Gal positive cells [(95.833 ± 1.528) %] in 20 μmol/L ginsenoside-treated K562 cells for 48 h was significantly higher than that of the control group [(3.083 ± 0.764) %]. Cells blocked in G0/G1 phase and entered S and G2/M phases were significantly higher and lower than those in the control group, respectively (P<0.05).The ATR and Chk1 mRNA expression levels [(0.0117 ± 0.0038) %, (0.0120 ± 0.0021) %] were significantly higher than that of the control group ([0.0027 ± 0.0006) %, (0.0058 ± 0.0019) %) (P<0.05). ATR and Chk1 relative protein expression levels [(19.370 ± 0.994) %, (43.520 ± 1.236) %] were significantly increased compared with that of the control group [(17.080 ± 1.274) %, (39.100 ± 0.969) %) (P<0.05).　Conclusion　Ginsenoside Rg1 can induce the aging of K562 cells by regulating the ATR-Chk1 pathway, providing a new target for clinical leukemia treatment.

Effect of ginsenoside Rg_1 in delaying premature ovarian failure induced by D-gal in mice through PI3K/Akt/mTOR autophagy pathway / 中国中药杂志

The aim of this paper was to study the role of phosphoinositide 3-kinase(PI3 K), protein kinase B(Akt) and mamma-lian target of rapamycin(mTOR) in the inhibition of premature ovarian failure induced by D-galactose(D-gal) in mice model by ginsenoside Rg_1(Rg_1). Fifty-four female SPF BALB/c mice were randomly divided into PBS group, D-gal group, and Rg_1 group. In the D-gal group, D-galactose(200 mg·kg~(-1)·d~(-1)) was injected subcutaneously into the neck and back for 42 days. In the PBS group, an equal amount of phosphate buffered saline(PBS) was injected into the neck and back for 42 days. In addition to the therapy of D-gal group, Rg_1 group was given Rg_1(20 mg·kg~(-1)·d~(-1)) through intraperitoneal injection since the 15 th day for 28 days, at the same time, the D-gal group and the PBS group were also given an equal amount of PBS through intraperitoneal injection since the 15 th day for 28 days. After the treatment, the estrous cycle changes of the mice were detected, and the ovarian SA-β-Gal staining was used to detect the changes of ovarian aging. Western blot was used to detect the changes in protein expressions of PI3 K, Akt, mTOR, S6 k, LC3-Ⅱ and P16~(INK4 a). Fluorescence quantitative PCR was used to detect the changes in mRNA expressions of PI3 K, Akt, mTOR, S6 k, LC3-Ⅱ and P16~(INK4 a). According to the findings, compared with the PBS group, the D-gal group began to show estrous cycle disorder in the 3 rd week,the ovarian SA-β-Gal staining positive granulosa cells increased in the D-gal group, the expression of senescence marker P16~(INK4 a) increased, while the expression of autophagy signaling molecule LC3-Ⅱ decreased. After treatment with Rg_1, the positive rate of ovarian SA-β-Gal staining in Rg_1 group decreased, the expression level of autophagy signaling molecule LC3-Ⅱ in Rg_1 group was higher than that in D-gal group, while the expression level of senescence marker P16~(INK4 a) was lower than that in D-gal group. Compared with the PBS group, the protein and mRNA expressions of PI3 K, Akt, mTOR and S6 k in the D-gal group were up-regulated, the protein expressions of Akt, mTOR and S6 k in the Rg_1 group were up-regulated, and the mRNA expressions of PI3 K and mTOR were up-regulated. After treatment with Rg_1, the protein expressions of PI3 K, Akt, mTOR and S6 k in the Rg_1 group were lower than those in the D-gal group, while the mRNA expressions of Akt, mTOR and S6 k in the Rg_1 group were lower than those in the D-gal group. The finding ssuggested that Rg_1 has the effect in delaying ovarian premature failure in D-gal-induced mouse models, and PI3 K/Akt/mTOR autophagy signaling pathways play an important role.

Ginsenoside Rg_1 induces leukemia stem cell senescence via SIRT1/TSC_2 signal axis / 中国中药杂志

The aim of this paper was to investigate the effect of SIRT1/TSC_2 signal axis on leukemia stem cell senescence induced by ginsenoside Rg_1. CD34~+CD38~- leukemia stem cells(CD34~+CD38~-LSCs) was isolated by magnetic cell sorting(MACS) and divided into two groups. The control group cells were routinely cultured, 40 μmol·L~(-1) ginsenoside Rg_1 was added to the control group for co-culture in Rg_1 group. The effect of Rg_l to induce CD34~+CD38~-LSCs senescence were evaluated by senescence-associated β-Galactosidase(SA-β-Gal) staining, cell cycle assay, CCK-8 and Colony-Assay. The expression of senescence associated SIRT1, TSC_2 mRNA and protein was examined by Real-time fluorescence quantitative PCR(FQ-PCR) and Western blot. The results showed that the CD34~+CD38~-LSCs could effectively be isolated by MACS, and the purity of CD34~+CD38~-LSCs is up to(95.86±3.04)%. Compared with the control group, the percentage of positive cells expressed SA-β-Gal in the Rg_1 group is increased, the senescence morphological changes were observed in the CD34~+CD38~-LSCs in the Rg_1 group. The proliferation inhibition rate and the number of cells entered G_0/G_1 phase in the Rg_1 group were increased, but the colony-formed ability was decreased, Rg_1 could significantly inhibit the proliferation and self-renewal ability of CD34~+CD38~-LSCs. The expression of SIRT1 and TSC_2 mRNA and protein were down regulated in the Rg_1 group compared with the control group. Our research implied that Rg_1 may induce the senescence of CD34~+CD38~-LSCs and SIRT1/TSC_2 signal axis plays a significant role in this process.