Host glial cell canceration induced by glioma stem cells in GFP/RFP dual fluorescence orthotopic glioma models in nude mice / 中华肿瘤杂志

<p><b>OBJECTIVE</b>During the process of tissue remodeling in human tumor transplantation models, the roles of the inoculated tumor cells and host tissue in tumor progression is still largely unknown. The aim of this study was to investigate the relationships and interactions between these two sides using GFP-RFP double fluorescence tracing technique.</p><p><b>METHODS</b>Red fluorescence protein (RFP) gene was stably transfected into glioma stem cell line SU3, then SU3-RFP cells were transplanted into the brain of athymic nude mice with green fluorescence protein (GFP) expression. After the intracerebral tumors were formed, the relationship and interaction between GFP cells and RFP cells were analyzed. Highly proliferative GFP cells were screened out, and monocloned with micro-pipetting. DNA content assay, chromosome banding and carcinogenicity test of the GFP cells were performed to observe the GFP cells' cancerous phenotype in nude mice.</p><p><b>RESULTS</b>In the transplantable tumor tissue, besides a great quantity of RFP cells, there were still a proportion of GFP cells and GFP/RFP fusion cells. The proportion of RFP cells, GFP cells and GFP/RFP cells were (88.99 ± 1.46)%, (5.59 ± 1.00)%, and (4.11 ± 1.020)%, respectively. Two monoclonal host GFP cells (H1 and H9) were cloned, which demonstrated the properties of immortality, loss of contact inhibition, and ultra-tetraploid when cultured in vitro. Both H1 and H9 cells expressed CNP, a specific marker of oligodendrocytes. The GFP cells also demonstrated 100% tumorigenic rate and high invasive properties in vivo.</p><p><b>CONCLUSIONS</b>In this glioma transplantation model, the transplanted tumor tissues contained not only transplanted glioma stem cells but also cancerous host GFP cells. Our findings offer important clues to further research on the relationships among different members in the tumor microenvironment.</p>

Screening for EXT1 and EXT2 gene mutations in a ethnic Han Chinese family from Shanxi with hereditary multiple exostoses / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To screen for potential mutations in an ethnic Han Chinese family from Shanxi with hereditary multiple exostoses.</p><p><b>METHODS</b>Polymerase chain reaction and DNA sequencing were used to screen potential mutations in EXT1 and EXT2 genes.</p><p><b>RESULTS</b>For EXT1 gene, two synonymous mutations (P477P and E587E), three intronic mutations (c.1537 -48A>G, c.1721 +203A>G and c.1722 -103C>G) were detected. For EXT2 gene, five intronic mutations (c.-29 -148A>T, c.1080 -18T>A, c.1336 -93C>T, c.1526 -166C>T, and c.1526 -195C>T) were identified. Among these, EXT1 P477P, EXT1 E587E and EXT2 c.1080 -18T>A are polymorphisms listed by Multiple Osteochondroma Mutation Database, whilst the other 7 sites have not been reported.</p><p><b>CONCLUSION</b>No mutations have been found among all exons of the EXT1 and EXT2 genes in this family. Linkage analysis is necessary for identifying the cause of this disease.</p>

Incubation and application of transgenic green fluorescent nude mice in visualization studies on glioma tissue remodeling / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The primary reasons for local recurrence and therapeutic failure in the treatment of malignant gliomas are the invasion and interactions of tumor cells with surrounding normal brain cells. However, these tumor cells are hard to be visualized directly in histopathological preparations, or in experimental glioma models. Therefore, we developed an experimental human dual-color in vivo glioma model, which made tracking solitary invasive glioma cells possible, for the purpose of visualizing the interactions between red fluorescence labeled human glioma cells and host brain cells. This may offer references for further studying the roles of tumor microenvironment during glioma tissue remodeling.</p><p><b>METHODS</b>Transgenic female C57BL/6 mice expressing enhanced green fluorescent protein (EGFP) were crossed with male Balb/c nude mice. Then sib mating was allowed to occur continuously in order to establish an inbred nude mice strain with 50% of their offspring that are EGFP positive. Human glioma cell lines U87-MG and SU3 were transfected with red fluorescent protein (RFP) gene, and a rat C6 glioma cell line was stained directly with CM-DiI, to establish three glioma cell lines emitting red fluorescence (SU3-RFP, U87-RFP, and C6-CM-DiI). Red fluorescence tumor cells were inoculated via intra-cerebral injection into caudate nucleus of the EGFP nude mice. Tumor-bearing mice were sacrificed when their clinical symptoms appeared, and the whole brain was harvested and snap frozen for further analysis. Confocal laser scanning microscopy was performed to monitor the mutual interactions between tumor cells and host brain cells.</p><p><b>RESULTS</b>Almost all the essential tissues of the established EGFP athymic Balb/c nude mice, except hair and erythrocytes, fluoresced green under excitation using a blue light-emitting flashlight with a central peak of 470 nm, approximately 50% of the offsprings were nu/nu EGFP+. SU3-RFP, U87-RFP, and C6-CM-DiI almost 100% expressed red fluorescence under the fluorescence microscope. Under fluorescence microscopic view, RFP+ cells were observed growing wherever they arrived at, locating in the brain parenchyma, ventricles, and para-vascular region. The interactions between the transplanted tumor cells and host adjacent cells could be classified into three types: (1) interweaving; (2) mergence; and (3) fusion. Interweaving was observed in the early stage of tumor remodeling, in which both transplantable tumor cells and host cells were observed scattered in the tumor invading and spreading area without organic connections. Mergence was defined as mutual interactions between tumor cells and host stroma during tumorigenesis. Direct cell fusion between transplantable tumor cells and host cells could be observed occasionally.</p><p><b>CONCLUSIONS</b>This study showed that self-established EGFP athymic nude mice offered the possibility of visualizing tumorigenesis of human xenograft tumor, and the dual-color xenograft glioma model was of considerable utility in studying the process of tumor remodeling. Based on this platform, mutual interactions between glioma cells and host tissues could be observed directly to further elucidate the development of tumor microenvironment.</p>

Study on three common mitochondrial DNA mutations in Leber's hereditary optic neuropathy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To screen for genetic mutations in 35 patients with Leber's hereditary optic neuropathy (LHON).</p><p><b>METHODS</b>Polymerase chain reaction and DNA sequencing were used to screen for the presence of mitochondrial DNA mutations.</p><p><b>RESULTS</b>The total detection rate of top 3 common LHON mutations were 20.0%, which included 6 cases of ND4 11778 G to A, 1 case of ND1 3460 G to A. No ND6 14484 T to C mutation was detected. A ND4 G11719A synonymous mutation was found in all patients. In addition, 21 other mutations were discovered among 23 patients, among which 13 had a single mutation, 8 had a second mutations, and 2 had a third mutation. Among the 21 mutations, ND4 11778 G to A had a frequency of 28.6%(6/21). ND1 3552 T to A, ND6 14470 T to C, ND4 11794 T to C, ND1 3497 C to T and 3644 T to C respectively had a frequency of 19.0% (4/21), 19.0%(4/21), 14.3%(3/21), 9.5%(2/21) and 9.5%(2/21). Among the 3 patients who harbored a ND4 11794 T to C mutation, 2 were heteroplasmic and one was homoplasmic in nature.</p><p><b>CONCLUSION</b>The ND4 11778 G to A mutation is common in the Top "3" primary mutations of patients with LHON. Candidate LHON mutation ND1 3552 T to A or ND1 3644 T to C resulted in LHON pathogenesis as single or synergistic effect. The visual impairment at onset of the disease with candidate mutation were better than the eyes with the ND4 11778 G to A mutation.</p>

Detection of exon 7 mutations of PAH gene in classical phenylketonuria by high-resolution melting analysis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish a simple, rapid, inexpensive and sensitive method for detecting hot region for mutations in exon 7 of PAH gene.</p><p><b>METHODS</b>High-resolution melting (HRM) technology was used to detect a c.728G>A mutation in exon 7 in 88 patients with classical type phenylketonuria. Suspected mutations were validated by direct DNA sequencing.</p><p><b>RESULTS</b>The results detected by HRM are in good agreement with the results obtained by direct sequencing.</p><p><b>CONCLUSION</b>HRM analysis is a simple, rapid, inexpensive and sensitive method for detecting hot mutational region in exon 7 of PAH gene.</p>

Preliminary studies on cell derivation of neovascularization in human glioma and its functional evaluation / 中华肿瘤杂志

<p><b>OBJECTIVE</b>The finding of vasculogenic mimicry (VM) in many solid tumors indicates that tumor cells themselves could participate in the construction of tumor vessels. However the origin of these cells is still not fully elucidated, and whether these vessels have the ability of blood-supply is still unclear. Preliminary studies were performed to investigate whether part of tumor neovascularity is derived from tumor stem cells (TSCs) and whether TSCs-derived vessels are functional.</p><p><b>METHODS</b>Transplanted glioma tissues obtained from subcutaneous and orthotopic transplantation nude mouse models were processed into paraffin sections. In order to identify the cell origin and types of tumor vessels, sections were stained with CD31, CD34, CD133, GFAP, Ki67 and HLA, respectively. CD34-PAS staining was performed as well. A part of tumor-bearing mice were perfused with activated carbon through the systemic circulation and the distribution of activated carbon was observed.</p><p><b>RESULTS</b>CD34-PAS staining showed that endothelium-dependent vessels (CD34(+), PAS(+)), VM vessels (CD34(-), PAS(+)), and the MVs (CD34(+), PAS(-)) could be seen in the transplantated tumors. Activated carbon particles were observed in all three types of vessels. CD31(+) cells adherent to the luminal surface of vessel wall. CD34(+) cells distributed along the vessels as well, but morphologically were more like a transition type between tumor cells and endothelial cells. Human specific Ki67 and HLA positive cells could be seen in the tumor vessels indicating that these vessels were derived from human tumor cells. Moreover, cells of tumor vessels were proved to be constructed by human tumor cells mainly and fusion cells of host cells and tumor cells under confocal microscope.</p><p><b>CONCLUSIONS</b>Three types of blood supply sources including endothelium-dependent vessels, vasculogenic mimicry (VMs) and mosaic vessels (MVs) exist in transplantation tumors of human glioma. Glioma stem and progenitor cells (GSCPs) have the potential to differentiate and transdifferentiate into VMs and MVs.</p>

Study on the mutations of phenylalanine hydroxylase gene in patients with phenylketonuria in Shanxi province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the mutations in exons 3, 6, 7, 11 and 12 of the phenylalanine hydroxylase gene (PAH) in Shanxi population.</p><p><b>METHODS</b>The mutations in exons 3, 6, 7, 11 and 12 and flanking sequences of PAH gene were detected by PCR-DNA sequencing, in 59 patients with phynelketonuria(PKU) and 100 healthy children from Shanxi province.</p><p><b>RESULTS</b>By sequence analysis, three single nucleotide polymorphism (SNP) Q232Q (CAA>CAG), V245V (GTG>GTA) and L385L (CTG>CTC) were detected in both the patients and healthy children, with the frequencies of nt 696, 735 and 1155 of the PAH cDNA up to 96.2%, 76.1% and 7.6% in patients respectively, and 97.0%, 77.3% and 8.3% respectively in the healthy controls. In addition, 72 different mutations accounting for 61.0% of mutant alleles were identified in the patients only. In exon 3, R111X, H64>TfsX9 and S70 del were found accounting for 5.1%, 0.8% and 0.8%; EX6-96A>G in exon 6 was found accounting for 10.2%. In exon 7, R243Q was the highest incidence accounting for 12.7%, followed by Ivs7+2 T>A(5.1%) and T278I(2.5%); the lowest incidences were G247V, R252Q, L255S, R261Q and E280K accounting for 0.8 %, respectively. In exon 11, Y356X (5.9%) and V399V (5.1%) were found; in exon 12, R413P and A434D were found accounting for 5.9% and 2.5%. In total, 9 missense mutations, 3 splice site mutations, 2 nonsense mutations and 2 deletions were included in 16 kinds of different mutations.</p><p><b>CONCLUSION</b>The mutation characteristics and distribution in exons 3, 6, 7, 11 and 12 of the PAH gene have been identified, and it suggested that the EX6-96A>G and R243Q were the hot spots of PAH gene mutations in Shanxi PKU population.</p>

Isolation and culture of tumor stem cells from human brain glioma tissues / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To isolate and culture tumor stem cells from glioma tissues obtained at surgical operation and to study their biological characteristics.</p><p><b>METHODS</b>Glioma tissues obtained from surgically resected specimens of 8 patients were fully chopped, trypsinized, and filtered to prepare single cell suspensions. The cells were cultured in serum-free medium with EGF, LIF and bFGF. CD133(+) cells were purified by magnetic cell sorting, and cultured continuously in vitro to obtain tumor cell spheres. Tumor stem cells of the 5th passage were induced to differentiate with 10% FBS, and expression of cell differentiation markers such as Nestin, MAP2, GFAP was evaluated with immunocytochemistry techniques.</p><p><b>RESULTS</b>CD133(+) cells were successfully separated and cultured from one anasplastic mixed astrocyte-ependymocyte type glioma specimen. These cells maintained a sphere-like growth status in vitro (3 months, 14 passages), and can self-renew, proliferate and conditionally differentiate into MAP2(+) and GFAP(+) cells. However, CD133(-) cells did not possess these properties.</p><p><b>CONCLUSION</b>Glioma tissue contains tumor stem cells. Those cells can be cultured and passaged in vitro for a long term, and therefore to offer new approaches for studying cellular and molecular biology of glioma.</p>