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Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal proliferative disease of hematopoietic stem cells. Various gene mutations, including the phosphatidylinositol glycan anchor biosynthesis class A (PIG-A) gene, may contribute to the proliferation of PNH clones. In order to explore the mechanism of PNH clone proliferation, a study was performed on 13 patients with PNH who underwent whole exome sequencing. The frequency of mutations in these patients was explored, and an additional 30 patients with PNH were selected for analysis of cluster of differentiation 59-negative (CD59−) cells. The mRNA expression of 13 genes, which were selected based on their high frequency in patients with PNH and the fact that they met four screening conditions, was determined in these CD59− cells. Cell proliferation, apoptosis and cell cycle were evaluated upon knocking down the recombinant signal binding protein of immunoglobulin κJ region (RBPJ) gene in 5 patients in vitro. The detection rate of PIG-A gene mutation was 61.54% (8/13), and additional mutations in somatic genes were detected, including RBPJ, zinc finger protein 717, polycomb repressive complex 2 subunit and tet methylcytosine dioxygenase. Upon screening according to the mutation frequency and expression level, the present study focused on the RBPJ gene. The expression level of RBPJ in CD59− cells was apparently higher than that in CD59+ cells and normal controls which was significantly correlated with clinical data. Furthermore, the expression of RBPJ in PNH primary cells could be effectively inhibited by small interfering RNA-RBPJ. Once the expression of RBPJ decreased remarkably, the apoptotic rate increased gradually, while cell proliferation activity decreased with transfection time and cells were blocked in G0/G1 phase. In conclusion, mutations and abnormal expression of the RBPJ gene may participate in the abnormal proliferation of PNH clones. [ABSTRACT FROM AUTHOR]

Breast cancer is the second leading cause of cancer-associated mortality in women worldwide. Strong evidence has suggested that Ran, which is a small GTP binding protein involved in the transport of RNA and protein across the nucleus, may be a key cellular protein involved in the metastatic progression of cancer. The present study investigated Ran gene expression in breast cancer tissue samples obtained from 140 patients who had undergone surgical resection for breast cancer. Western blot analysis of Ran in breast cancer tissues and paired adjacent normal tissues showed that expression of Ran was significantly increased in breast cancer tissues. Immunohistochemistry analyses conducted on formalin-fixed paraffin-embedded breast cancer tissue sections revealed that Ran expression was associated with tumor histological grade, nerve invasion and metastasis, vascular metastasis and Ki-67 expression (a marker of cell proliferation). Kaplan-Meier survival analysis showed that increased Ran expression in patients with breast cancer was positively associated with a poor survival prognosis. Furthermore, in vitro experiments demonstrated that highly migratory MDA-MB-231 cancer cells treated with Ran-si-RNA (si-Ran), which knocked down expression of Ran, exhibited decreased motility in trans-well migration and wound healing assays. Cell cycle analysis of Ran knocked down MDA-MB-231 cells implicated Ran in cell cycle arrest and the inhibition of proliferation. Furthermore, a starvation and re-feeding (CCK-8) assay was performed, which indicated that Ran regulated breast cancer cell proliferation. Taken together, the results provide strong in vitro evidence of the involvement of Ran in the progression of breast cancer and suggest that it could have high potential as a therapeutic target and/or marker of disease. [ABSTRACT FROM AUTHOR]