Comparative Assessment of Vitamin-B12, Folic Acid and Homocysteine Levels in Relation to p53 Expression in Megaloblastic Anemia

Abstract

BackgroundMegaloblastic anemia (MBA), also known as macrocytic anemia, is a type of anemia characterized by decreased number of RBCs as well as the presence of unusually large, abnormal and poorly developed erythrocytes (megaloblasts), which fail to enter blood circulation due to their larger size. Lack of vitamin-B12 (VB12) and / or folate (Vitamin-B9, VB9) with elevated homocysteine is the key factor responsible for megaloblastic anemia. Prior studies have demonstrated the induction of apoptosis in these abnormal under-developed erythrocytes. However, it is not clear whether this apoptosis induction is due to elevated p53 level or due to any other mechanism. Furthermore, it is also not fully known whether decreased vitamin-B12 and / or folate are responsible for apoptosis induction mediated by p53 in pre-erythroblasts.MethodsLevels of serum VB9, VB12 and homocysteine in 50 patients suffering from MBA were compared with 50 non-megaloblastic anemia control subjects, who were referred by the clinicians for bone marrow examination for medical conditions other than MBA. Next, we have measured the p53 expression in the paraffin embedded blocks prepared from bone marrow biopsy, using immunohistochemistry, and the expression levels correlated with VB9 and VB12 levels.ResultsOut of 50 MBA patients 40 (80%) and 44 (88%) subjects had very low VB12 and VB9 levels respectively. In contrast, only 2 (4%) and 12 (24%) non-megaloblastic anemia controls, out of 50 subjects, had low VB12 and VB9 respectively. Correlating with low vitamin B9 and B12, the homocysteine levels were high in 80% cases. But, only 20% non-megaloblastic controls exhibited high homocysteine in plasma. Immunohistochemical analysis for p53 expression showed a significantly high level of expression in MBA cases and no—or very low—expression in control subjects. Our correlation studies comparing the VB12 and VB9 levels with p53 expression concludes unusually high p53 levels in patients suffering from VB12 and VB9 deficiency induced MBA compared to control subjects not suffering from MBA.ConclusionTumor protein p53 is the key protein expressed heavily in the bone marrow biopsies of patients suffering from VB12 and VB9 deficiency induced MBA but not in control subjects. Hence, p53 expression could be used as a surrogate marker for confirming the VB9 and VB12 induced MBA.

Vitamin B12 and Semen Quality

“…Therefore, a wide symptomatic spectrum is related to vitamin B 12 deficiency ranging from fatigue and depression to severe anemia and memory loss [6,7,8]. …”

“…Vitamin B 12 is involved in the metabolism of almost all cells in the human body as it is required for DNA synthesis, as well as amino acid and fatty acid metabolism [ 5 ]. Therefore, a wide symptomatic spectrum is related to vitamin B 12 deficiency ranging from fatigue and depression to severe anemia and memory loss [ 6 , 7 , 8 ].…”

Visualization and Analysis of the Interaction Network of Proteins Associated with Blood-cell targeting Autoimmune Diseases

“…Moreover, in accordance with the study of Guinn et al (1995) (70), high levels of TP53 have been recorded in an ITP patient ( Supplementary Figure 6, B ). More recent evidence by Yadav et al (71) in 2016, shows overexpression of TP53 in pernicious anemia (PA) patients – indicating TP53 as a primary apoptosis inducer in megaloblasts ( Supplementary Figure 6, D ).…”

Deoxyuracil in DNA and disease: Genomic signal or managed situation?

“…Folate deficient erythroblasts cultured in folate deficient medium demonstrated increased uracil misincorporation into DNA and increased p53 and p21 accumulation compared to control cells (95). Patients with megaloblastic anemia often demonstrate primary folate deficiency or a secondary folate deficiency due to vitamin B12 deficiency, as well as increased p53 accumulation in bone marrow, compared to non-megaloblastic anemia controls (96). Additional challenges to de novo dTMP biosynthesis, including deleterious mutations in DHFR and antifolate treatment, are associated with megaloblastic anemia (97,98).…”