ABSTRACT
Objective To detect the hypermethylation of HOXB6 gene in gastric cancer tissue and investigate the relationship between the gene expression and the clinics.Methods seven types of gastric cancer cell line and 73 cases of gastric cancer biopsy tissues were measured by combined bisulfite restriction analysis method.The gene expression and the re-expression after demethylation were detected by RT-PCR.Results Of 7 cell lines examined, 4 showed hypermethylation.The methylating status of HOXB6 was found to be correlated with loss of expression,which was restored by 5-aza-2＇-deoxycytidine treatment.We also find hypermethylation in 20/73(27.40%)case of cancer tissues but no one in non cancer tissue.Conclusion There are close relationship between hypermethylation and gene silencing in the HOXB6 gene of gastric cancer,There are also a gene re-expression after its demethylation.Hypermethylation of HOXB6 gene can be a tumor marker for gastric cancer diagnosis,and the agent of demethylation maybe a new antineoplastic drug.
ABSTRACT
Objective To observe the expression level of HOXB6 gene on the differentiation and proliferation of hematopoietic stem cells(HSC) to colony forming unit-granulocyte-monocyte(CFU-GM),erythroid progenitor(CFU-E) and colony forming unite-T-lymphocyt(CFU-TL).And the proliferation procress was affected by all-transretinoic acid(ATRA).Methods 1.By the colony culture in vitro,the impact of ATRA on the CFU-GM,CFU-E,CFU-TL colony formation were surveyed;the expressions of HOXB6 gene were observed on the differentiation procress of HSC to CFU-GM,CFU-E and CFU-TL affected by ATRA on the 3rd,7th,12th.2.Real-time fluorogenic quantitative reserve transcription-polymerize chain reaction(FQ-RT-PCR) method was used to explore the possible mechanism of ATRA up-regulated to human cord blood CFU-GM,CFU-E and CFU-TL in gentic level.Results 1.HOXB6 gene had a regulatory function in the differentiation procress of hematopoiesis.During the differentiation and proliferation of HSC to colony forming CFU-GM or CFU-E,CFU-TL in vitro,the expressions of HOXB6 gene were significant positive.2.Compared with the expressions of CFU-GM and CFU-TL HOXB6 mRNA on day 3,the quantity of HOXB6 mRNA was obviously higher on day 7 and lower on day 12,respectively in each group.Compared with the expression of CFU-E HOXB6 mRNA on day 3,the quantity of HOXB6 mRNA was obviously higher on day 12 in each group.3.Compared with the HOXB6 gene of control group,the expressions of HOXB6 gene of group ATRA were up-regulated remarkable.Conclusions 1.HOXB6 gene has a regulatory function in the differentiation procress of hematopoiesis.HOXB6 gene plays an important role in the progress which can be associated with the regulating effect of HOXB6 gene on the differentiation and proliferation of CFU-GM,CFU-E and CFU-TL.2.During the differentiation and proliferation of HSC,the expression of HOXB6 gene is regular in time.3.Low concentration of ATRA(60 ?mol?L-1) can up-regulate the expression of HOXB6 gene,which confirms the theory that the normal hematopoie-tic lineage determination and maturation rely on the stable and consistent expression of HOXB6 gene.