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Background WNT7a, a member of the Wnt ligand family implicated in several developmental processes, has also been reported to be dysregulated in some types of tumors; however, its function and implication in oncogenesis is poorly understood. Moreover, the expression of this gene and the role that it plays in the biology of blood cells remains unclear. In addition to determining the expression of the WNT7A gene in blood cells, in leukemia-derived cell lines, and in samples of patients with leukemia, the aim of this study was to seek the effect of this gene in proliferation. Methods We analyzed peripheral blood mononuclear cells, sorted CD3 and CD19 cells, four leukemia-derived cell lines, and blood samples from 14 patients with Acute lymphoblastic leukemia (ALL), and 19 clinically healthy subjects. Reverse transcription followed by quantitative Real-time Polymerase chain reaction (qRT-PCR) analysis were performed to determine relative WNT7A expression. Restoration of WNT7a was done employing a lentiviral system and by using a recombinant human protein. Cell proliferation was measured by addition of WST-1 to cell cultures. Results WNT7a is mainly produced by CD3 T-lymphocytes, its expression decreases upon activation, and it is severely reduced in leukemia-derived cell lines, as well as in the blood samples of patients with ALL when compared with healthy controls (p ≤0.001). By restoring WNT7A expression in leukemia-derived cells, we were able to demonstrate that WNT7a inhibits cell growth. A similar effect was observed when a recombinant human WNT7a protein was used. Interestingly, restoration of WNT7A expression in Jurkat cells did not activate the canonical Wnt/β-catenin pathway. Conclusions To our knowledge, this is the first report evidencing quantitatively decreased WNT7A levels in leukemia-derived cells and that WNT7A restoration in T-lymphocytes inhibits cell proliferation. In addition, our results also support the possible function of WNT7A as a tumor suppressor gene as well as a therapeutic tool.

Background Fragile X Syndrome (FXS) and its associated disorders are caused by the expansion of the CGG repeat in the 5’ untranslated region of the fragile X mental retardation 1 (FMR1) gene, with disease classification based on the number of CGG repeats. The mechanisms of repeat expansion are dependent on the presence of cis elements and the absence of trans factors both of which are not mutually exclusive and contribute to repeat instability. Expansions associated with trans factors are due to the haploinsuffient or reduced expression of several DNA repair/metabolizing proteins. The reduction of expression in trans factors has been primarily conducted in animal models without substantial examination of many of these expansion mechanisms and trans factors in humans. Results To understand the trans factors and pathways associated with trinucleotide repeat expansion we have analyzed two microarray datasets which characterized the transcript expression in patients with FXS and in controls. Conclusion We observed significant down regulation of DNA damage/repair pathway transcripts. This observation was consistent in both datasets, which used different populations. Within these datasets, several transcripts overlapped in the direction of association and fold change. Further characterization of these genes will be critical to understand their role in trinucleotide repeat instability in FXS.