[Clinical phenotype and genetic analysis of a patient with 12q22-qter duplication and Xq23-qter deletion caused by maternal balanced translocation].

OBJECTIVE: To explore the clinical phenotype and genetic diagnosis of a patient featuring secondary amenorrhea, breast dysplasia and mental retardation. METHODS: Peripheral venous blood samples were collected from the patient and her family members and subjected to G-banding karyotyping and single nucleotide polymorphism array (SNP-array) analysis. RESULTS: The patient was found to have a karyotype of 46,X,der(X)(12qter→ 12q22::Xq23→ Xpter)mat, her mother had a karyotype of 46,X,t(X;12)(Xpter→ Xq23::12q22→ 12qter;12pter→ 12q22::Xq23→ Xqter), while her father and brother were both 46,XY. SNP-array analysis suggested the patient to be arr[hg19]12q22q24.33(94 792 972-133 777 562)× 3, Xq23q28(108 786 070-155 233 098)×1. CONCLUSION: The abnormal phenotypes of the patient can probably be attributed to the presence of Xq23-qter deletion and 12q22-qter duplication, both have derived from her mother's balanced t (X;12) translocation.

[Increased expression of acetaldehyde dehydrogenase in cisplatin-resistant human lung adenocarcinoma A549/DDP cells].

OBJECTIVE: To investigate the expression and biological significance of acetaldehyde dehydrogenase (ALDH) in cisplatin-resistant human A549/DDP lung adenocarcinoma cell line. METHODS: The expressions of biomarkers of cancer stem cells (CSCs) including CD44, CD73, CD90, CD105, epithelial cell adhesion molecule (EpCAM), ATP-binding cassette sub-family G member 2 (ABCG2) and ALDH in human lung adenocarcinoma A549 cells and cisplatin-resistant A549/DDP cells were ascertained by flow cytometry. The proliferation and sensitivity of A549/DDP cells to cisplatin were evaluated by MTT assay before and after ALDH inhibitor diethylaminobenzaldehyde (DEAB) treatment. The differential expression of ALDH subtypes in cells was determined by real-time quantitative PCR, and was further confirmed by a Western blotting. RESULTS: The frequencies of ABCG2 and ALDH positive cells were higher in cisplatin-resistant A549/DDP cells than those in A549 cells, in particular the expression of ALDH which was 97.7% in A549/DDP cells, and only 4.3% in A549 cells. There was no significantly differential expression of CD44, CD90, CD73, CD105 between A549/DDP cells and A549 cells, whereas less EpCAM was found in A549/DDP cells compared with A549 cells. Importantly, the ALDH inhibitor DEAB (100 µmol/L) was able to significantly reduce cisplatin resistance in A549/DDP cells. Compared with A549 cells, the expressions of ALDH subtypes ALDH1A3 and ALDH1B1 mRNA significantly went up in A549/DDP cells. Interestedly, Western blotting revealed that ALDH1B1 protein expression was elevated but ALDH1A3 protein was reduced in A549/DDP cells in comparison with A549 cells. CONCLUSION: ALDH can serve as a useful surface marker for cisplatin-resistant human lung adenocarcinoma cells.ALDH1B1 may play a role in the chemoresistance of these cells. Therefore, ALDH1B1 may be an important target for developing novel therapeutic agents and strategies for patients with cisplatin-resistant lung adenocarcinoma.

Alteration of histone acetylation pattern during long-term serum-free culture conditions of human fetal placental mesenchymal stem cells.

Increasing evidence suggests that the mesenchymal stem cells (MSCs) derived from placenta of fetal origin (fPMSCs) are superior to MSCs of other sources for cell therapy. Since the initial number of isolated MSCs is limited, in vitro propagation is often required to reach sufficient numbers of cells for therapeutic applications, during which MSCs may undergo genetic and/or epigenetic alterations that subsequently increase the probability of spontaneous malignant transformation. Thus, factors that influence genomic and epigenetic stability of MSCs following long-term expansions need to be clarified before cultured MSCs are employed for clinical settings. To date, the genetic and epigenetic stability of fPMSCs after long-term in vitro expansion has not been fully investigated. In this report, alterations to histone acetylation and consequence on the expression pattern of fPMSCs following in vitro propagation under serum-free conditions were explored. The results show that fPMSCs maintain their MSC characteristics before they reached a senescent state. Furthermore, acetylation modification patterns were changed in fPMSCs along with gradually increased global histone deacetylase (HDAC) activity and expression of HDAC subtypes HDAC4, HDAC5 and HDAC6, as well as a down-regulated global histone H3/H4 acetylation during in vitro culturing. In line with the acetylation alterations, the expression of oncogenes Oct4, Sox2 and TERT were significantly decreased over the propagation period. Of note, the down-regulation of Oct4 was strongly associated with changes in acetylation. Intriguingly, telomere length in fPMSCs did not significantly change during the propagating process. These findings suggest that human fPMSCs may be a safe and reliable resource of MSCs and can be propagated under serum-free conditions with less risk of spontaneous malignancy, and warrants further validation in clinical settings.

Placental mesenchymal stem cells of fetal origin deposit epigenetic alterations during long-term culture under serum-free condition.

OBJECTIVE: Fetal placental mesenchymal stem cells (fPMSCs) have shown promising cell therapy potentials. However, their genetic and epigenetic stability during in vitro propagation has not been well studied. We thus interrogated the methylation alterations and tumorigenicity of fPMSCs after in vitro expansion using serum-free medium. RESEARCH DESIGN AND METHODS: The properties of fPMSCs cultured in a serum-free medium at passage 3 and passage 8 were ascertained by determining their MSC markers, proliferative capacity, chromosomal stability, activity of global DNA methyltransferases and methylation profile. Their potential of malignant transformation was also evaluated in a severe combined immunodeficiency (SCID) murine model. RESULTS: The fPMSCs could maintain their MSC characteristics but quickly reached a senescent state of proliferation during in vitro expansion. 246 genes with differential DNA methylation of promoters were identified, along with a significantly downregulated global DNA methyltransferase activity. The genes associated with aging and tumorigenesis had a significantly demethylated tendency over in vitro propagation. However, the deposition of epigenetic alterations did not translate into malignant transformation in SCID mice. CONCLUSION: The fPMSCs cultured in serum-free medium have a tendency to deposit methylation modifications over in vitro expansion, therefore the detection of genetic and/or epigenetic alterations is necessary for fPMSCs before they are employed for clinical uses.