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Biomedical subjects

Lan Sun

Publications and source records attributed to Lan Sun.

24 records · Page 2Linked to original sources
PubMed2002

Regulative function of telomerase and extracellular regulated protein kinases to leukemic cell apoptosis.

In order to investigate the regulative function of telomerase and phosphorylated (activated) extracellular regulated protein kinase (ERK) 1 and 2 in the leukemic cell lines HL-60 and K562 proliferation inhibition and apoptosis, three chemotherapeutic drugs Harringtonine (HRT), Vincristine (VCR) and Etoposide (Vp16) were selected as inducers. The proliferation inhibition rate was detected by MTT method, the cell cycle and cell apoptosis was analyzed by flow cytometry and the telomerase activity was detected by the telomeric repeat amplification protocol (TRAP) assay and bioluminescence analysis method. The phosphorylated ERK1/2 protein expression was detected by western blot method. The results showed that HRT, VCR and Vp16 could inhibit cell proliferation, induce apoptosis, inhibit telomerase activity and down-regulate the protein expression of phosphorylated ERK. It was suggested that ERK signal transduction pathway was involved in the down-regulation of telomerase activity and the onset of apoptosis in the leukemic cells treated by HRT, VCR and Vp16.

Antineoplastic Agents↗
PubMed2002

[Effect of praeruptorum caumarin on cardiac mass, myocardial [Ca2+]i and Na+, K(+)-ATPase, Ca2+, Mg(2+)-ATPase activity in renovascular hypertensive rats].

AIM: To investigate the preventive and reversional effect of praeruptorum caumarin compound on left ventricular hypertrophy in renovascular hypertensive rats (RHR) and its mechanism. METHODS: The two-kidney-one-clip (2K1C) RHR model was used. The blood pressure, wet weight of the left ventricle, surface area of myocardial cells, resting [Ca2+]i level and Na+, K(+)-ATPase, Ca2+, Mg(2+)-ATPase activity of myocardial membrane and mitochondria were measured. RESULTS: Praeruptorum caumarin 30 mg.kg-1.d-1 was given ig for 9 weeks from the 6th or 9th week after operation in the preventive or regressive group. The blood pressure, left ventricle wet weight and area of myocardial cells of the preventive and regressive group were significantly reduced than that of the LVH group. The resting [Ca2+]i of the both praeruptorum caumarin treated groups (121 +/- 13, 133 +/- 9 nmol.L-1) were lower than that of the LVH group (158 +/- 7 nmol.L-1). The KCl-induced [Ca2+]i elevation was decreased more significantly in preventive and regressive group than that of the hypertrophic myocytes. The activity of Na+, K(+)-ATPase and Ca2+, Mg(2+)-ATPase increased by 40% and 93% in the preventive group, 28.4% and 48.8% in regressive group than that of the LVH group. CONCLUSION: Praeruptorum caumarin was shown to prevent and reverse hypertrophy of LVH by lowering [Ca2+]i and increasing the ATPase activity.

Animals↗
PubMed2002

[Two flavone glycosides from Chinese traditional medicine Amomum villosum].

OBJECTIVE: To study the water soluble constituents from Amomum villosum. METHOD: The constituents were separated and purified with chromatographic methods, identified by NMR, MS, UV and IR. RESULT: Two quercetin glycosides: quercitrin (quercetin-3-O-alpha-L-rhamnoside I) and isoquercitrin (quercetin-3-O-beta-D-glucoside II) were isolated and identified. CONCLUSION: I and II were isolated for the first time from A. villosum.

Amomum↗
PubMed2001

[Establishment of the Cell Line U937-ASPI3K with Stable Expression of Antisense ATM/PI3K]

In order to provide a valuable cell model for studying the mechanism of DNA damage to kill tumor cells and enhance the curative effect, an antisense cDNA, which effectively expressed ATM gene encoding carboxyl terminal 100 kD domain fragment, was constructed, and a cell line U937-ASPI3K, which stably expressed the antisense ATM/PI3K cDNA was established through transfection and Zeocin selection. The results showed the constructed ATM/PI3K cDNA is in the opposite orientation in expression vector pZeoSV2(+) through examination of gene sequence. The cell line U937-ASPI3K was total loss of constitutive ATM protein, while the ATM abundance was not influenced in both the control cell lines U937-pZeoSV(-) and U937. The present experiment provided a practical cell model to elusidate mechanism of cell cycle checkpoints in DNA damage signal transduction pathway and search a new approach for tumor therapy.

Journal Article↗
PubMed1998

Murihexol, a linear acetogenin from Annona muricata.

Murihexol (1), a novel acetogenin, and three known ones, donhexocin (2), annonacin A and annonacin, have been isolated from the seeds of Annona muricata. Compound 1 is a C(35) acetogenin without any THF rings, with six hydroxyls in the long aliphatic chain. The hydroxyls of 1 and 2 are all located at C-4, C-10, C-15, C-16, C-19 and C-20, but their stereochemistries are different. The vicinal diol at C-15/C-16 in 1 is threo and C-19/C-20 has the erythro configuration; in 2 C-15/C-16 and C-19/C-20 all have the same threo configuration.

Journal Article↗