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Li Yao

Publications and source records attributed to Li Yao.

46 records · Page 3Linked to original sources
PubMed2003

[Expression of survivin, Fas, bcl-2 and bax in bone marrow cells from acute myeloid leukemia patients and its clinical significance].

UNLABELLED: To study the clinical significance of the expression of antiapoptosis gene, survivin and bcl-2, and proapoptosis gene, Fas and bax, in acute myeloid leukemia (AML), RT-PCR was used to examine the expression of survivin and flow cytometry (FCM) to detect the expression of Fas, bcl-2, bax and bcl-2/bax ratio in 68 cases of AML. The results demonstrated that: (1) The positivity of survivin mRNA expression was significantly higher in AML compared to control (70.6% vs 30%, P < 0.05). (2) The expression of Fas and bcl-2 in AML before treatment was significantly higher than that in control (P < 0.001), but the bax expression did not (P > 0.05). (3) The survivin-positive AML cases showed a significantly lower Fas and higher bcl-2 expression in comparison with survivin-negative ones (P < 0.01 and P < 0.001, respectively), but the bax did not (P > 0.01). (4) Survivin-positive AML cases had a lower CR rate as compared with survivin-negative cases (64.6% vs 90%, P < 0.05). (5) The survivin-positive CR cases showed a decreased expression of Fas and bcl-2 after treatment in comparison with pretreatment expression (P < 0.001), but the bax expression remained unchanged before and after therapy. The survivin-positive NR cases showed a significantly decreased Fas and increased bcl-2 expression as compared with pretreatment expression (P < 0.001). bcl-2/bax ratio was also significantly higher in NR cases. IN CONCLUSION: 70.6% AML cases showed positive for survivin expression with a lower CR rate, the survivin-positive AML showed a low Fas with high bcl-2 expression and bcl-2/bax ratio as compared to the survivin-negative cases.

Adolescent↗
PubMed2003

[A dual-color fluorescence in situ hybridization study on the detection of inv(16) in acute myeloid leukemia].

OBJECTIVE: To explore the value of dual-color fluorescence in situ hybridization (D-FISH) in the detection of inv(16) in acute myeloid leukemia (AML). METHODS: Eleven AML patients were investigated by D-FISH with two-color break apart probe for MYH11 labeled directly by fluorescein isocyanate (FITC) and a Texas Red. The results were associated or compared with those of cell morphology, cytogenetics, single color fluorescence in situ hybridization (FISH) and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Four cases (M4Eo three cases, M2a one case) had inv(16), of which one had trisomy 22 in addition to inv(16), while the other seven cases had no inv(16), of which, five cases (M4Eo three cases, M4 two cases)had a normal karyotype, one (M2a) had 5p+ and trisomy 22, one (M4Eo) had a translocation t(9;22) on G-banded karyotypic analysis. All 11 cases of AML were positive for the rearrangement of inv(16) detected by D-FISH. The average positive cell rate for these 11 AML patients was 93.45% (range 86.6%-98.7%). Of them, four had a minimal deletion of 16p13 in addition to inv(16). The results of D-FISH coincided with those of RT-PCR or single color FISH. CONCLUSION: D-FISH is a powerful tool for the detection of inv(16) due to its sensitivity and specificity. For raising the detecting rate of inv(16), it is necessary to screen inv(16) rearrangement by D-FISH in all M4- and M2-AML cases or the cases with trisomy 22, no matter whether they are accompanied by bone marrow eosinophilia.

Chromosome Inversion↗
PubMed2003

[Relationship among telomerase activity, expression of human telomerase reverse transcriptase (hTERT), and expression of c-myc in acute leukemia].

BACKGROUND & OBJECTIVE: Regulation of expression of human telomerase reverse transcriptase(hTERT) is regarded as the major determinant of telomerase activity. Several studies suggested that c-myc could regulate hTERT expression. This study was designed to examine the telomerase activity, the expression of hTERT and c-myc, and to analyze their correlations in acute leukemia. METHODS: The telomerase activity was semi-quantitatively assayed in mononuclear cells (MNCs) of bone marrow (BM) from 35 acute leukemia patients and 15 control cases by polymerase chain reaction enzyme- linked immunosorbent assay (PCR-ELISA). The mRNA expression of hTERT and c-myc were determined using reverse transcription polymerase chain reaction (RT-PCR) at the same time. RESULTS: The mean telomerase activity, the expression levels of the hTERT mRNA and c-myc mRNA in acute leukemia were 0.71+/-0.32, 0.47+/-0.36, and 0.85+/-0.31, respectively, which was significantly higher than those of control cases (P< 0.01). The telomerase activity and the expression level of c-myc mRNA were associated with the expression level of hTERT mRNA (P< 0.01). In the 25 follow-up patients, the mean telomerase activity and the expression level of the hTERT were 0.61+/-0.39 and 0.29+/-0.31 in complete remission cases, while 0.83+/-0.23 and 0.53+/-0.31 in none complete remission cases, respectively. There was no significant difference between the two groups. CONCLUSION: The telomerase activity and the expression of hTERT and c-myc mRNA were up-regulated in acute leukemia, and the elevated expression of hTERT may be an important adjuster of telomerase activity. It is likely that c-myc protein can stimulate the expression of hTERT and thereby enhance telomerase activity, which may involve in carcinogenesis of leukemia.

Acute Disease↗
PubMed2003

[The expression and clinical implication of gelatinase A in acute leukemic cells].

OBJECTIVE: To study the expression of gelatinase A (MMP2) in acute leukemic cells and its clinical implication. METHODS: The bone marrow samples from 46 acute leukemia patients were investigated by reverse transcription polymerase chain reaction (RT-PCR) and Gelatin Zymography method. Matrigel invasion assay was studied on U937, NB4, K562 and SHI1 cells in vitro. RESULTS: The expression of MMP2 was positive in 24 of 46 patients with AL (52.2%). In MMP2 positive and negative groups of AL, the extramedullary infiltration rates were 50.0% and 18.2% (P < 0.05), whilst the percentage of blast cell in peripheral white blood cells were (77.21 +/- 13.9)% and (62.95 +/- 17.2)% (P < 0.01), respectively. The positive expression of TIMP2 and MT1-MMP in 46 AL patients were 27 (58.7%) and 33 (71.7)%. The matrigel invasion assay suggested that MMP2 is involved in migration of leukemic cell through extracellular matrix (Matrigel). CONCLUSION: The active form of MMP2 might be essential to the egress of leukemic cells from bone marrow into peripheral blood, followed by an extramedullary infiltration.

Acute Disease↗
PubMed2003

[Improved RT-PCR for detection of PML/RARalpha fusion gene in rapid diagnosis of acute promyelocytic leukemia].

Detection of the PML/RARalpha fusion gene by RT-PCR in acute promyelocytic leukemia (APL) blasts is not only critical to commence promptly the specific therapy with all-trans retinoic acid (ATRA) or arsenic trioxide (As(2)O(3)), but also essential for the definition of PML breakpoint type and subsequent monitoring of minimal residual disease (MRD). The current PML/RARalpha amplification techniques with conventional nested PCR are laborious and time consuming, which fails to meet the requirements for rapid diagnosis of APL in clinical practice. Therefore, an easily handled RT-PCR methodology for the rapid and accurate amplification of PML/RARalpha fusion transcripts is needed. A modified one round RT-PCR protocol was described with a few variations which includes rapid extraction of high quality cellular total RNA, cDNA synthesis with random hexamer and M-MLV reverse transcriptase, optimal concentrations of MgCl(2) (1 mmol/L), PCR primers (0.4 micro mol/L) and Taq polymerase (0.01 U/ micro l), hot-start procedure, and concomitant amplification of PML/RARalpha fusion gene and RARalpha internal control under the identical thermocycle parameters. The results in 40 patients with newly diagnosed APL showed that the improved RT-PCR protocol allowed the rapid detection of PML/RARalpha fusion gene and the accurate discrimination of its transcript types, and simultaneous amplification of RARalpha internal control under the identical program in less than 6 hours. There were no false positive or negative results found with the assay. In conclusion, the assay reported here is proved to be a simple, easily handled, and highly specific procedure for the diagnosis of APL cases, particularly those requiring such urgent therapeutic intervention as ATRA or As(2)O(3) and meriting its further application in APL management.

Humans↗
PubMed2002

Correlation of functional and structural alterations of the coronary arterioles during development of type II diabetes mellitus in rats.

OBJECTIVE: Cardiac complications in diabetes mellitus (DM) are frequently ascribed to microangiopathy. Therefore, we sought to directly correlate the serial changes in coronary arterial function with the extent of coronary arteriolar remodeling in a model spontaneously developing type II DM. METHODS: Otsuka Long-Evans Tokushima Fatty (OLETF) rats and control Long-Evans Tokushima Otsuka (LETO) rats were used. At 5, 15 and 30 weeks of age, ten rats in each group were subjected to systemic and coronary hemodynamic measurements using the colored microsphere technique before and during maximal coronary hyperemia and histological assessment with Azan-Mallory stain of the coronary arterioles. RESULTS: As early as 15 weeks of age, at which time fasting plasma glucose concentration remained normal, OLETF rats exhibited a lower coronary flow reserve and a greater coronary vascular resistance during hyperemia than did LETO rats. On histomorphometry, OLETF rats exhibited a greater wall-to-lumen ratio and a greater degree of perivascular fibrosis of arterioles at 15 weeks of age and thereafter, both of which exhibited a significant correlation with the minimal coronary vascular resistance. CONCLUSIONS: The degree of functional deterioration in coronary circulation was directly correlated with the severity of coronary arteriolar structural remodeling during the development of microangiopathy in early stage of DM.

Animals↗
PubMed2002

Thymidine phosphorylase expression in oral squamous cell carcinoma.

Thymidine phosphorylase (TP), as an enzyme involved in DNA synthesis, catalyzes the reversible conversion of thymidine to thymine. It is also identical to the angiogenic factor, platelet-derived endothelial cell growth factor. We examined TP expression using immunohistochemistry in 66 archival samples obtained from the patients with primary oral squamous cell carcinoma (SCC) and investigated its relation to tumor vascularity, cell proliferation, apoptosis, clinicopathological features and survival. TP expression was identified in cytonucleus and/or cytoplasm in carcinomas, but was not identified in histologically normal epithelia distant to tumor in most cases. No significant difference of microvessel density (MVD) was found between the carcinomas with high TP expression (H-TP) and low TP expression (L-TP). The percentages of proliferative cells marked by Ki-67 staining in H-TP carcinomas was significantly higher than that in L-TP carcinomas (P=0.0222). The apoptotic indice (AI) in H-TP carcinomas tended to be lower than that in L-TP carcinomas (P=0.0723). Moreover, the level of TP expression was significantly correlated the pattern of tumor invasion (P=0.0146) and marginally correlated with lymph nodal metastasis (P=0.0804). Our results suggested that TP enzyme may play a role in promotion of tumor growth in oral SCC, and that its expression can be indicative of tumor aggressiveness in this tumor type.

Apoptosis↗
PubMed2002

[Effects of sodium orthovanadate on proliferation and apoptosis in raji cells and its mechanism].

In order to investigate the role and the mechanism of protein tyrosine phosphatase (PTPase) signaling pathway in the regulation of proliferation, cell cycle and apoptosis in lymphoma cells, the effects of sodium orthovanadate, Na(3)VO(4), a specific PTPase inhibitor, were explored on Raji lymphoblast-like cell line by MTT assay and CFU-Raji culture, morphologic observation, DNA gel electrophoresis, FCM and RT-PCR. Results showed that MTT assay and CFU-Raji culture demonstrated that sodium or thovanadate inhibited the growth of Raji cells in a concentration-dependent fashion; morphologic observations showed that Raji cells exhibited cytoplasm shrinkage, cytoplasm membrane blebbing, nuclear fragmentation and chromatin condensation forming crescents along nuclear membrane characteristic of apoptosis in the presence of Na(3)VO(4); DNA gel electrophoresis revealed typical DNA ladder reminiscent of DNA cleavage at internucleosomal sites in Na(3)VO(4) treated cells; FCM and RT-PCR indicated that Na(3)VO(4) intervention increased the fraction of annexin V(+) PI(-) cells, reduced the value of mitochondrial transmembrane potential, induced G(2)/M arrest and down-regulated the expression of Bcl-2 and cyclin B1 at both mRNA and protein level in a concentration-dependent manner. It was concluded that PTPase pathway might be implicated in the regulation of cell proliferation, cell cycle and apoptosis, and PTPase specific inhibitor Na(3)VO(4) could induce Raji cell growth inhibition, G(2)/M arrest and apoptosis via down-regulation of Bcl-2 and cyclin B1, and reduction of mitochondrial transmembrane potential.

Apoptosis↗
PubMedDate not supplied

Monitoring gene expression profile changes in bladder transitional cell carcinoma using cDNA microarray.

PURPOSE: Differential gene expression profiles between normal bladder mucosas and bladder transitional cell carcinomas TCC were detected. MATERIALS AND METHODS: cDNA microarrays were prepared by spotting PCR products of 12,800 human genes onto specially treated glass slides. The cDNA probes were prepared by labeling normal bladder mucosa mRNA and TCC tissue mRNA with Cy3-dUTP and Cy5-dUTP respectively through reverse transcription. The arrays were then hybridized against the cDNA probe mixture and the fluorescent signals were scanned. The ratios of Cy5/Cy3 were computed. Northern analysis was used to confirm the results of microarray hybridization. RESULTS: Eighty-three genes (0.65%), whose ratios of Cy5/Cy3 were greater than 4.0 or less than 0.25, were screened out after 10 groups of hybridization. In the cancerous tissues 28 of them showed higher expression and 55 lower. Twenty-three genes are unregistered in GenBank. These differentially expressed genes are always involved in the physiological processes such as signal transduction, apoptosis and cell cycle, etc. CONCLUSIONS: This technique provides a powerful method for quantitative analysis of the expression levels of thousands of genes in parallel, and is used to identify genes involved in TCC carcinogenesis. The data obtained by this means are comparable to those obtained by other methods. Using cDNA microarrays to define alterations in gene expression associated with a specific cancer may be an efficient way to uncover the clues to specific molecular derangements that account for its pathogenesis and thus identify potential targets for therapeutic intervention.

Aged↗