Telomerase activity and the expression of telomerase subunits (for example, telomerase reverse transcriptase and telomerase associated protein 1 and telomerase RNA component) of peripheral white blood cells were detected in the patients with acute myelogenous leukaemia (AML) and the correlation between telomerase activity and the expression of telomerase subunits was observed. In 94 peripheral white blood cells from 18 healthy volunteers and 76 patients with AML, including 31 AML at initial presentation, 24 at relapse and 21 at complete remission, the telomerase activity and telomerase subunits mRNA or RNA were detected by PCR-ELISA and RT-PCR respectively. The results showed that the positive rate of telomerase from patients with AML at initial presentation, at relapse and at complete remission was 74.1%, 79.2% and 4.8% respectively. The positive rate of telomerase reverse transcriptase mRNA from healthy volunteers, AML at initial presentation. AML at relapse and AML at complete remission was 5.6%, 80.6%, 83.3% and 9.5% respectively. The positive rate of telomerase associated protein 1 mRNA and telomerase RNA component in all samples were 100%. It was suggested that the up-regulation of telomerase activity and the expression of telomerase reverse transcriptase is correlated closely with the occurrence and relapse of AML, so telomerase activity and the expression of telomerase reverse transcriptase may be used to estimate the curative effect and predict relapse of AML. Moreover, the upregulation of telomerase activity is correlated with the expression of telomerase reverse transcriptase significantly.
To investigate the expression of Bcl-2 and Bcl-xl gene in sensitive (A2780) and drug-resistance (AD6) human ovarian cancer cell lines and explore the molecular mechanism of multidrug resistance. A2780 and AD6 were detected by using DNA gel electrophoresis, flow cytometry and RT-PCR. Our results showed that (1) “DNA ladder” was observed in A2780 and AD6 after cisplatin treatment; (2) after 3.0, 6.0, 9.9 μg/ml of cisplatin treatment, a significant difference was noted in the rate of apoptosis between in A2780 and AD6 (P<0.05); (3) Bcl-2 and Bcl-xl genes were overexpressed in AD6. After cisplatin treatment, the expression of Bcl-2 and Bcl-xl genes was down-regulated in A2780 and AD6. It is concluded that cisplatin could induce the apoptosis of ovarian cancer cells, and the over-expression of Bcl-2 and Bcl-xl genes may contribute to apoptotic inhibition and the development of multidrug-resistance of human ovarian cancer.
The relationship between glutathione S-transferases (GSTs) M1, T1 genotype and childhood acute lymphoblastic leukemia (ALL) was investigated. GSTM1 and GSTT1 genotypes in genomic DNA from 67 children with ALL and 146 healthy controls were analyzed by using the multiplex polymerase chain reaction (PCR). The frequencies of GSTM1, M1-T1 null genotypes in ALL children were significantly higher than in the healthy controls (76. 12% versus 52.74%. OR=2. 856.P<0.001: 50.74% versus 24.66%, OR=3.148,P<0.01, respectively). However, there was no significant relationship between GSTT1 null genotype and ALL of children (61.19% versus 49.32%. OR=1.621.P>0.05). It was suggested that GSTM1 null genotype might be a risk genotype of childhood ALL. While there as no correlation between GSTT1 null genotype and childhood ALL.
To study the effects of free fatty acids on insulin secretion and expression of SUR1 gene in rat pancreatic B cellsin vitro, and to explore the molecular mechanisms in lipotoxicity inducing insulin secretion dysfunction, pancreatic islet cells were isolated and digested from male SD rats. Purified islets were incubated with either 0.25 mmol/L palmitate or 0.125 mmol/L oleate for 48 hin vitro. Then islets were stimulated with either 5.6 mmol/L or 16.7 mmol/L glucose for 1 h. Insulin release was measured by using radioimmunoassay, and the expression of SUR1 gene mRNA was quantified by reserve transcription-polymerase chain reaction (RT-PCR). The islets exposed to both palmitate and oleate for 48 h showed an increased basal and a decreased glucose-indused insulin release as compared with control islets. Palmitate increased basal insulin secretion by 110 % (P<0.01), decreased glucose stimulated insulin secretion by 43% (P<0.01); while oleate increased basal insulin secretion by 80% (P<0.01) and decreased glucose stimulated insulin secretion by 32% (P<0.05). RT-PCR showed that oleate significantly suppressed SUR1 gene expression by 64% (P<0.01) as compared with the control group, while palmitate group manifested a light decrease of 15% (P>0.05) of SUR1 gene expression. Our results suggested that chronic exposure to free fatty acids of pancreatic β cells inhibited glucose stimulated insulin secretion. Regulation of SUR1 gene expression may be involved in such effects, which may also be one of the molecular mechanisms in lipotoxocity inducing β cells secretion dysfunction.
The effects of early hemofiltration on the serum levels of cytokines, pro-and anti-inflammatory balance and organ function in pigs with severe acute pancreatits (SAP) were studied. SAP pig model was induced by retrograde injection of artificial bile into the pancreatic duct. The pigs were randomly divided into SAP hemofiltration treatment group (HF group,n=8) and SAP nonhemofiltration treatment group (NHF group,n=8). In the HF group, the animals were subjected to high-volume and zero-balance hemofiltration therapy. The results showed that as compared with NHF group, MAP, CVP and PaO2/FiO2 were significantly increased (P<0.01), while HR, urinary protein content, serum ALT level, pulmonary coefficient and lung wet/dry ratio obviously decreased (P<0.05) in HF group. Under a light microscope, the pulmonary histologic scoring was lower that in HF group (P<0.01) and the lesions of renal and liver tissues were milder. However, there was no significant difference in the pancreatic histologic scoring between the two groups. Six h after establishment of the model, the serum levels of TNF-α, IL-1β were lower, while the IL-10/TNF-α ratio was higher in HF group (allP<0.05). It was suggested that early hemofiltration could effectively remove the serum cytokines TNF-α and IL-1β in SAP pigs, elevate the ratio of IL-10/TNF-α, improve hemodynamics and alleviate the lesions of lung, kidney and liver tissues.