[ long non-coding RNA, PSORS1C3, located upstream of the human Oct4 gene is expressed in pluripotent and tumor cell lines]

Long non-coding RNAs [lncRNAs], a vast class of recently discovered noncoding genes in the human genome, have been implicated in the regulation of several biological processes, including the maintenance of stem cell pluripotency and neurogenesis. New evidences have emerged that some long IncRNAs act as enhancers for their neighboring genes. Oct4, also known as POU5F1 and Oct3/4, functions as a master regulator in maintaining the properties of pluripotency and self-renewal of embryonic stem [ES] cells and embryonal carcinoma [EC] cells. Oct-4 expression must be tightly regulated; too much or too little expression can lead to cell differentiation. PSORS1C3, an IncRNA, is located upstream of the Oct4 gene. This IncRNA could potentially impact the level of Oct4 expression. Here, we have investigated potential expression of PSORS1C3 on 23 different human pluripotent and cancer cell lines by means of RT-PCR. Our results revealed a noticeable expression of PSORS1C3 both in a well-known pluripotent cell line [NTera2/NT2] and five different cancer cell lines [AGS, 5637, Ht-29, HepG2 and PC3]. We detected the expression of PSORS1C3 for the first time in both cancer cell lines and stem cells

Overexpression of BMI1, a polycomb group repressor protein, in bladder tumors: a preliminary report

A polycomb group repressor protein named BMI1 represses the genes that induce cellular senescence and cell death, and it can contribute to cancer when improperly expressed. We aimed to evaluate expression of BMI1 gene in bladder tumors. Tissue specimens containing bladder tumor were evaluated and compared with intact tissues from tumor margins and normal bladder. These were 40 tumor specimens of patients with transitional cell carcinoma of the bladder, 20 tumor-free tissues taken from the margin of the tumors, and 8 specimens from patients without tumor. Specific primers for BMI1 and B2M [as an internal control] were used for reverse transcript polymerase chain reaction technique. The production and distribution of BMI1 protein was also examined by western blotting and immunohistochemistry techniques. Polymerase chain reaction generated a 683-bp product, corresponding to the expect size of BMI1 amplified region. The identity of the amplified fragment was then confirmed by direct DNA sequencing. The mean of expression of BMI1 detected in tumor tissues was significantly higher than that in intact tissues, and there was also a significant association between the mean of gene expression and the stage of malignancy [P<0.001]. The expression of BMI1 at protein level was further confirmed by western blotting and immunohistochemistry. BMI1 is a potent repressor of retinoblastoma and p53 pathways, and hence, elucidating its role in tumorigenesis is very important. We reported for the first time the expression of BMI1 and its correlation with incidence and progress of bladder tumors