Enhancement of 5'-nucleotidase activity of human leukemic cells after fractionation: implications for cancer and aging

Pyrimidine 5’Nucleotidase I and II Activities in Acute Leukaemias

Bacground and objective: Pyrimidine 5’nucleotidase I and II activities of peripheral mononuclear cells were studied to evaluate their role in diagnosis, assessment of therapy and follow up of remission in acute leukaemias. Design and methods: Blood samples were obtained from 40 untreated patients with acute lymphoblastic and myeloid leukaemia and 40 healthy controls, before the therapy and after remission. The correlation between the activity of the enzymes and the efficacy of therapy were established. The enzyme activities were measured by High-Performance Liquid Chromatography (HPLC), using the method described by Amici. For statistical analysis, Mann-Whitney U, Kruskal-Wallis and Wilcoxon methods were used. Results: Before the therapy, Pyrimidine 5’nucleotidase I levels in the leukaemic group were found to be significantly elevated when compared to the control group (p<0.001). Also Pyrimidine 5’nucleotidase II levels were significantly elevated before the therapy and during remission (p<0.02 and p<0.001 respectively). The isoenzyme activities were compared in patients who were in remission, who did not respond to therapy and in patients who died during the therapy, but no significant difference was found. Interpretation and conclusions: We concluded that, Pyrimidine 5’nucleotidase I and II activities can be used as markers for diagnosis and follow up of remission in patients with acute leukaemia. But, they can not have predictive value for prognosis.

Oleanolic acid suppresses vascular smooth muscle cell proliferation by increasing lincRNA-p21 expression

Arteriosclerosis poses a significant risk to human health and involves the thickening and hardening of the walls of arteries. Accumulated evidence demonstrates that aberrant proliferation of vascular smooth muscle cells (VSMCs) accounts for the onset and progression of arteriosclerosis. Suppression of their proliferation has been demonstrated to be an effective anti-arteriosclerosis strategy. Long non-coding RNAs (lncRNAs) have recently been observed to be implicated in the proliferation of VSMCs and arteriosclerosis. In this study, we observed that oleanolic acid (OA), a natural compound from plants, inhibited the proliferation of VSMCs. The expression of lincRNA-p21, an arteriosclerosis-associated lncRNA, was demonstrated to be elevated by OA treatment. Suppression of lincRNA-p21 rescued the effect of OA on the proliferation of VSMCs. Collectively, targeting lncRNA is a promising strategy for arteriosclerosis prevention and treatment, and OA ameliorates arteriosclerosis by increasing lncRNA levels.

Expression of the murine plasma cell nucleotide pyrophosphohydrolase PC-1 is shared by human liver, bone, and cartilage cells. Regulation of PC-1 expression in osteosarcoma cells by transforming growth factor-beta

A bone and cartilage enzyme with both 5'-nucleotide phosphodiesterase I and nucleotide pyrophosphohydrolase (NTPPPH) activity modulates physiologic mineralization and pathologic chondrocalcinosis by generating inorganic pyrophosphate. We hypothesized that, as for alkaline phosphatase, expression of an NTPPPH gene can be shared by cells from bone, cartilage, and liver and by certain leukocytes. Recently, we demonstrated the hepatocyte and murine plasma cell membrane glycoprotein PC-1 to have both 5'-nucleotide phosphodiesterase I and NTPPPH activity. We detected polypeptides cross-reactive with PC-1 in human U20S osteosarcoma cells, articular chondrocytes, homogenized human knee cartilages, human knee synovial fluids, hepatoma cells, and murine plasmacytoma cells. Constitutive low abundance PC-1 mRNA expression was detected in U20S cells and chondrocytes by a nested RNA-PCR assay and by Northern blotting. TGF beta is known to substantially increase NTPPPH activity in primary osteoblast cultures. We demonstrated that TGF beta 1 increased NTPPPH activity and the level of PC-1 mRNA and immunoprecipitable [35S]-methionine-labeled PC-1 polypeptides in U20S cells. The identification of PC-1 as an NTPPPH expressed in cells derived from bone and cartilage may prove useful in furthering the understanding of the role of NTPPPH i n physiologic and pathologic mineralization.