ABSTRACT
@# Objective: To investigate the correlation between the expression of E2F1 and growth arrest and DNA damage inducible protein 45g (GADD45g) in patients with acute myeloid leukemia (AML), and to explore whether GADD45g exerts its induction of DNA damage, cell apoptosis, senescence, cell cycle arrest and drug sensitivity in AML through inhibition of E2F1. Methods: A total of 32 cases of bone marrow specimens from patients initially diagnosed asAML in Hospital of Blood DiseasesAffiliated to ChineseAcademy of Medical Sciences from January 2013 to December 2016, were selected for this study; In addition, AML cell lines (U937, HL60, THP-1, Molm-13) were also collected for this study. The mRNAexpression of GADD45g and E2F1 in above mentioned specimens and cell lines by qPCR,andtheircorrelationwasalsoanalyzed.Thelentiviral vector over-expressing E2F1 (pLV-E2F1-RFP) was constructed to prepare recombinant lentivirus, which was then transfected Molm-13 and THP-1 cells that over-expressing GADD45g. Whether GADD45g exerts tumor inhibition effect on AML cells through inhibition of E2F1 was determined by comet assay, Annexin V/7AAD flow cytometry, β-galactosidase staining and PI staining flow cytometry etc. Results: The mRNA expression of GADD45g was negatively correlated with E2F1 in bone marrow of AML patients and AML cell lines (r=–0.663, P<0.01). Over-expression of GADD45g significantly inhibited the expression of E2F1 in AML cell lines (all P<0.01). Molm-13 and THP-1 cells that simultaneously over-expressing GADD45g and E2F1 were successfully constructed. Compared with the control group, the protein expressions of GADD45g and E2F1 in over-expression groups were significantly increased (all P<0.01). Compared with cells over-expressing GADD45g alone, simultaneous over-expression of both GADD45g and E2F1 significantly reduced the apoptosis, senescence and DNA damage (all P< 0.01), and rescued cell cycle arrest in Molm-13 and THP-1 cells (all P<0.01), thus further reduced the chemo-sensitivity of AML cells caused by GADD45g over-expression (all P<0.01). Conclusion: GADD45g exerts anti-tumor effect inAMLvia inhibition of E2F1.
ABSTRACT
Objective:To explore the relationship between the expressions of MCM5 and E2F-1 with the genesis,clinicopathological parameters of gastric carcinoma.Methods:Immunohistochemistry SP method was used to detect the expressions of MCM5 and E2F-1 in gastric car- cinoma tissues of 57 cases and in normal gastric mucosa of 20 cases.The correlation between expressions of MCM5 and E2F-1 and clinicopathological parameters of gastric carcinoma was analysed. Results:The positive expression rate of MCM5 in cancer tissues was 71.9%(41/57),while in normal mucosa it was 0(0/20).The difference between the two groups was statistically significant (P0.05).The correlation between MCM5 and E2F-1 expressions in gastric carcinoma was highly significant positive(r=0.635,P=0.000).Conclusion: Overexpression of MCM5 and E2F-1 corelates with occurence and development of gastric carcinoma.MCM5 and E2F-1 may work in the early phase in carcinogenesis of gastric carcinoma.
ABSTRACT
AIM: To observe the effect of E2F decoy DNA on proliferation and apoptosis of androgen-independent prostate cancer cell line PC-3M.METHODS: E2F decoy DNA,ARE decoy DNA and control decoy DNA were transfected into PC-3M cells with lipofectamine,respectively.Their effects on cell proliferation were detected by MTT assay.The changes of cell morphology were observed by inverted phase contrast microscope.The cell apoptotic rate was determined by flow cytometry(FCM) analysis and chromosome DNA ladder was detected by DNA gel electrophoresis.The expression of c-Myc mRNA and cyclin D1 mRNA was detected by RT-PCR.The protein levels of c-Myc and cyclin D1 were detected by Western blotting.RESULTS: The growth of PC-3M cells was inhibited after transfection.The transfected PC-3M cells displayed typical apoptotic morphological changes.The apoptotic rate was 26.35% and DNA ladder was observed after transfection.The expression of c-Myc and cyclin D1 were inhibited.CONCLUSION: These results indicate that E2F decoy DNA induces apoptosis of androgen-independent prostate cancer cell lines PC-3M and inhibits cell proliferation via inhibiting expression of c-Myc and cyclin D1.