Enhanced polo-like kinase 1 expression in myelodysplastic syndromes

BACKGROUND: Cancer is characterized by uncontrolled cellular proliferation, and Polo-like kinase 1 (PLK1), a key regulator of the cell cycle, is overexpressed in many cancers, including acute leukemia and lymphoma. However, the dynamics of PLK1 transcription in myelodysplastic syndromes (MDS) are unknown. This study aimed to investigate the transcript dynamics of PLK1 and determine its role in the pathophysiology of MDS. METHODS: PLK1 mRNA obtained from the bone marrow samples of 67 patients with MDS, 16 patients with secondary acute myeloid leukemia (sAML), and 10 healthy controls were analyzed using quantitative real-time PCR and compared according to various clinical parameters. RESULTS: The median PLK1 expression levels differed slightly, but not significantly, between MDS and sAML patients [661.21 (range, 29.38–8,987.31) vs. 1,462.05 (32.22–5,734.09), respectively], but were significantly higher (P<0.001) than the levels in the healthy controls [19.0 (1.60–49.90)]. Further analyses of PLK1 levels according to the WHO classification of MDS, prognostic risk groups, karyotype risk groups, marrow blast percentage, and depth of cytopenia did not reveal any significant associations. In patients progressing to sAML, PLK1 expression levels differed significantly according to the presence or absence of resistance to hypomethylation treatment (2,470.58 vs. 415.98, P=0.03). CONCLUSION: PLK1 is upregulated in MDS patients; however, its role in the pathophysiology of MDS is unclear. Gene upregulation in cases with pharmacotherapeutic resistance warrants further investigation.

Enhanced differentiation of mesenchymal stromal cells by three-dimensional culture and azacitidine

BACKGROUND: Mesenchymal stromal cells (MSCs) are useful for cell therapy because of their potential for multilineage differentiation. However, MSCs that are expanded in traditional two-dimensional (2D) culture systems eventually lose their differentiation abilities. Therefore, we investigated whether azacitidine (AZA) supplementation and three-dimensional culture (3D) could improve the differentiation properties of MSCs. METHODS: 2D- or 3D-cultured MSCs which were prepared according to the conventional or hanging-drop culture method respectively, were treated with or without AZA (1 µM for 72 h), and their osteogenic and adipogenic differentiation potential were determined and compared. RESULTS: AZA treatment did not affect the cell apoptosis or viability in both 2D- and 3D-cultured MSCs. However, compared to conventionally cultured 2D-MSCs, AZA-treated 2D-MSCs showed marginally increased differentiation abilities. In contrast, 3D-MSCs showed significantly increased osteogenic and adipogenic differentiation ability. When 3D culture was performed in the presence of AZA, the osteogenic differentiation ability was further increased, whereas adipogenic differentiation was not affected. CONCLUSION: 3D culture efficiently promoted the multilineage differentiation of MSCs, and in combination with AZA, it could help MSCs to acquire greater osteogenic differentiation ability. This optimized culture method can enhance the therapeutic potential of MSCs.

Regulation of TGF-beta 1 and Collagen Expression by Antisense Oligodeoxynucleotide in Human Corpus Cavernosum Smooth Muscle Cells / 대한남성과학회지

PURPOSE: Transforming growth factor (TGF)-beta 1 stimulates collagen synthesis in human corpus cavernosum smooth cells (HCCSMC). We studied whether an antisense TGF-beta 1 oligodeoxynucleotide changed TGF-beta 1 mRNA expression and its related collagen synthesis. MATERIALS AND METHODS: The HCCSMC were cultured primarily from three impotent patients. Expression of TGF-beta 1 mRNA was induced by phorbol 12-myristate 13-acetate (PMA) 0.2 micro gram/ml in the presence or absence of antisense TGF-beta 1 oligodeoxynucleotide (5'-GGGCGGCATGGGGGA-3') 20 micro gram/ml. The effect of the antisense oligodeoxynucleotide on TGF-beta 1 mRNA and collagen I synthesis were measured by RT-PCR or Northern blot analysis. RESULTS: The expression of TGF-beta 1 mRNA in response to PMA was inhibited by treatment with the antisense oligodeoxynucleotide. Collagen I expression was also induced by PMA treatment, and the antisense oligodeoxynucleotide downregulated this expression. CONCLUSIONS: Antisense TGF-beta 1 oligodeoxynucleotide can suppress the expression of TGF-beta 1 and TGF-beta 1-induced collagen I synthesis in HCCSMC.