ABSTRACT
Objective: Ghrelin is a peptide which has a proliferative and antiapoptotic effect in many cells including bone marrow stromal cells [BMSCs]. Homeobox protein B4 [HOXB4] is a transcription factor involved in stem cell regeneration and survival. The aim of the study was to find out the effect of ghrelin on Hoxb4 expression in BMSCs
Materials and Methods: In this experimental study, rat BMSCs were cultivated in Dulbecco's Modified Eagle Medium [DMEM]. Passage three BMSCs were treated with ghrelin 100 micro M for 48 hours. Real-time polymerase chain reaction [PCR] was carried out from the untreated BMSCs [B], BMSCs treated with 125 micro M H2O2 [BH], BMSCs treated with 100 microM ghrelin then 125 microM H2O2[BGH] and BMSCs treated with 100 micro M ghrelin [BG] groups. For immunofluorescence, cells were incubated with an anti-HOXB4 monoclonal antibody. Primary antibodies were visualized using the Fluorescein isothiocyanate [FITC] method. All data are presented as mean +/- SEM and P<0.05 was considered as statistical significant
Results: Hoxb4 expression significantly increased in the BG compared with BH and BGH groups. Furthermore, 100 microM ghrelin, increased the mean of HOXB4 positive immunoreactive cells compared to the BH group
Conclusion: Ghrelin probably enhances proliferation and viability of BMSCs through Hoxb4 upregulation. However, the signaling pathway and other biological outcomes of this effect should be elucidated in different stem cells
ABSTRACT
The Bcl-2 protein family members have known as essential controllers of mitochondrial pathway of apoptosis. Bax is a proapoptotic member of Bcl-2 protein family, which is well known to play crucial roles for apoptosis control. bax has been implicated as potential tumor suppressor in certain solid tumors such as breast and colorectal carcinoma. DNA methylation of promoter associated CpG islands has known as a common mechanism for gene inactivation in tumor cells. The Methylation Specific PCR [MSP] has used to find the methylation profile of the bax gene promoter CpG islands in colorectal and breast cancer cell lines. We have not detected any kind of "CpG islands hyper methylation" in promoter region of the bax gene in T47D, MCF7 [as ER positive], MDA-MB-231 and MDA-MB-468 [as ER negative] breast carcinoma-derived cell lines and colorectal cancer cell lines H29 and Caco II. It seems that CpG island methylation could not play the main role in down-regulation of bax gene in breast and colon cancers