Search PubMed⌕ Search

Biomedical subjects

Yan-qun Na

Publications and source records attributed to Yan-qun Na.

50 records · Page 3Linked to original sources
PubMed2004

[Diagnosis and treatment of multilocular cystic renal cell carcinoma: a study of 22 cases].

OBJECTIVE: To summarize the diagnosis and treatment of multilocular cystic renal cell carcinoma (MCRCC), a special subtype of renal cell carcinoma. METHODS: The clinical data of 22 cases of MCRCC diagnosed and treated from January 1998 to December 2002 in the First Hospital of Peking University were analyzed retrospectively. RESULTS: 482 patients with renal cell carcinomas were hospitalized during that period with a male-to-female ratio of 2.09:1. Out of the 482 cases 22 cases (4.56%) were classified as MCRCC with a male-to-female ratio of 2.67:1, not significantly different from that of the general group of renal cell carcinoma patients (P > 0.05). The mean age of the patients of MCRCC was 46.6 years, significantly lower than that of the patients with other types of renal cell carcinomas (57.83 years, P< 0.01). Eighteen cases were diagnosed correctly as renal carcinomas before operation. Six patients (27%) were at the stage pT(1)N(0)M(0), 15 (68%) at the stage pT(2)N(0)M(0), and 1 (5%) at the stage pT(3)bN(0)M(0). The classification according to the tumor nuclear grading system showed 5 carcinomas (23%) of tumor nuclear grade 1, 17(77%) are of tumor nuclear grade 2. Eighteen patients underwent radical renal nephrectomy and 4 underwent partial nephrectomy. CONCLUSION: The preoperative diagnosis of MCRCC, difficult to be differentiated from other cystic renal diseases, mainly depends on imaging studies. Intraoperative frozen-section or nephron sparing surgery will benefit the patients if the preoperative diagnosis is unclear, especially for the patients of category 3 or 4 of Bosniak's system.

Adult↗
PubMed2004

[Genetic risk factors of prostate cancer in Han nationality population in Northern China and a preliminary study of the reason of racial difference in prevalence of prostate cancer].

OBJECTIVE: To investigate the genetic polymorphisms of the three major susceptibility genes, AR, VDR, and SRD5A2 genes, in the Han nationality population in Northern China with a low risk of prostate cancer (Pca) and the relationship of these polymorphisms to the susceptibility to Pca, and to discuss the possible reason causing racial difference of prevalence of PCa. METHODS: Restriction fragment length polymorphism (RFLP) technique and denaturing high-performance liquid chromatography (DHPLC) were used to detect the polymorphic sites in the DNAs from the peripheral blood samples of 116 patients with PCa and 190 normal male controls, all of Han nationality in Northern China. The distribution frequencies of different polymorphic sites were compared with those of the populations with high risk of prostate cancer. RESULTS: The frequencies of SRD5A2 and VDR genotypes were not significantly different between the Pca patients and the controls (P > 0.05). The frequency of CAG repeat < 22 was significantly higher in the Pca group than in the control group (P < 0.05). Statistical analyses of the AR genotype prevalence showed significant differences between the PCa patients and the controls (P < 0.05). The frequencies of AR, VDR, and SRD5A2 genotypes showed significant difference between the Han population in Northern China and the high-PCa risk populations in Western countries. The frequency of CAG > or = 22 was 80.4% in the Han people in Northern China, significantly higher than that in the US Caucasians (52.1%) and Afro-Americans (25%, both P < 0.001). CONCLUSION: There is a significant association between the AR gene CAG polymorphisms and PCa in the Han nationality population in Northern China. The distributions of the genotypes of AR, SRD5A2 and VDR gene are different among different ethnic population, which may be one of the reasons causing the racial difference in prostate cancer risk.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2004

[Somatic mutations of VHL gene and HIF-1alpha expression in primary renal clear cell carcinomas].

OBJECTIVE: To evaluate the significance of somatic mutations of VHL gene and hypoxia-inducible factor-1alpha (HIF-1alpha) expression in primary renal clear cell carcinoma (RCC). METHODS: Mutation of VHL gene and HIF-1alpha expression were detected by means of PCR, denaturing high-performance liquid chromatography (DHPLC), direct sequencing and immunohistochemistry in 32 samples from primary renal clear cell carcinoma patients. RESULTS: In 32 RCC samples, 17 samples (53.1%) had and 32 samples of adjacent nonmalignant renal tissue had not mutations of VHL gene expression. Twelve RCC samples (70.6%) which had mutations of VHL gene expressed HIF-1alpha, and it had significant difference to 4 RCC (26.7%) samples which didn't have mutations of VHL gene (P < 0.05). CONCLUSION: Mutations of VHL gene may play a significant role in the tumorigenesis of RCC, and HIF-1alpha expression correlates with it.

Adenocarcinoma, Clear Cell↗
PubMed2004

[Prevention of cell death in LNCaP cells by overexpression of clusterin].

OBJECTIVE: To evaluate the effect of clusterin with and without leader sequence on overexpression preventing apoptosis in human prostate LNCaP cells. METHODS: The plasmid pIRES2-EGFP was used to generate the clusterin expression constructs with full-length or without the leader sequence (designated as pIRES2-EGFP/cluac, pIRES2-EGFP/clubc, respectively). Western blot analysis was employed to compare clusterin expression levels in the lysis and supernatant fluid of clusterin transfected LNCaP cells in vitro. The distribution of different functional domains of clusterin in cells was detected with Immunocytochemical staining. The clusterin's protective role of Na2SeO3-induced apoptosis in LNCaP cells was examined by flow cytometry (FCM) and fluorescence microscope. RESULTS: Clusterin expression was detected in the lysis and supernatant fluid of pIRES2-EGFP/cluac transfected LNCaP cells, while clusterin was found only in lysis liquid of pIRES2-EGFP/clubc transfected LNCaP cells, but not found in their supernatant fluid. The distribution of cluserin in the plasm of pIRES2-EGFP/cluac transfected cells was aggregative, and on the other hand, clusterin distributed dispersedly in pIRES2-EGFP/clubc transfected cells. Its anti-apoptotic property in LNCaP cells was proved by FCM and fluorescence microscope. CONCLUSION: It is apparent that clusterin plays an important role in preventing apoptosis in prostate cancer, and the presence of the leader sequence is necessary for clusterin's anti-apoptotic function.

Apoptosis↗
PubMed2004

[Expression of MAGE genes and MAGE gene products in human renal and urinary bladder tumor].

OBJECTIVE: To observe the expression of MAGE-1 MAGE-3 genes and MAGE-3 gene product in renal and urinary bladder tumor, and to explore the possibility of MAGE-1 and MAGE-3 genes encoding proteins or MAGE-3 gene product used as a target for immunotherapy in renal and urinary bladder tumor patients. METHODS: Reverse transcriptase polymerase chain reaction for MAGE-1 and MAGE-3 genes was performed using 39 renal and urinary bladder tumor specimens. Immunohistochemical technique for MAGE-3 antigen was performed using formal infixed paraffin embedded section of 121 renal and urinary bladder tumor specimens. RESULTS: MAGE-1 and MAGE-3 mRNAs were detected in 23(59.0%) and 22(56.4%) of 39 patients with renal and urinary bladder tumor without expression in 10 tumor surrounding tissues.MAGE-3 antigen was detected in 56(46.3%) of 121 patients with renal and urinary bladder tumor without expression in 10 tumor surrounding tissues. The expression rates of MAGE-1 and MAGE-3 mRNA and MAGE-3 gene product were significantly higher in renal and urinary bladder tumors tissues than in tumor surrounding tissues. The frequency of MAGE-3 gene product expression was examined according to clinical stage and differentiation of histopathology. The results revealed no significant differences in MAGE gene product expression among the clinical stage and the grade of differentiation of histopathology according to Logistic Regression test(P>0.05). CONCLUSION: The tumor-specific antigens might be used as molecular markers and targets for human renal and urinary bladder tumor.

Adult↗
PubMed2004

[Frequent somatic mutations of the von Hippel-Lindau (VHL) tumor suppressor gene and its meaning in sporadic human renal clear cell carcinoma].

OBJECTIVE: To investigate the mutation of VHL gene, an important tumor suppressor gene in primary sporadic human renal cell carcinoma (RCC) and analyse its relationships with pathological stage and grade of renal cell carcinoma. METHODS: We analyzed 57 cases of primary sporadic Chinese renal clear carcinoma using the polymerase chain reaction (PCR) and denaturing high performance liquid chromatography(DHPLC). All positive cases in DHPLC analysis were further characterized by direct sequencing. RESULTS: Somatic mutations were detected in 30 (53%) of 57 clear cell renal carcinomas including 13 deletions, 2 insertions, and 15 missense mutations. These mutations mainly occurred in the last one-third region of exon 1, 2,and 3. CONCLUSION: VHL tumor suppressor gene is one of the major tumor suppressor genes in human renal cell carcinoma and there are frequent mutations of VHL in primary sporadic Chinese renal clear cell carcinomas. The mutations of VHL gene were irrespective of the age and pathological grade and stage of patients.

Adult↗
PubMed2003

[Wnt/Frizzled signaling pathway in renal carcinoma].

OBJECTIVE: To investigate the transduction of Wnt/Frizzled signaling pathway, especially the function of T cell factor 4 (TCF(4)), in renal carcinoma. METHODS: A renal carcinoma yeast two hybrid library and a human TCF(4) yeast two hybrid expression vector were constructed. Proteins interacting with the bait protein human TCF(4) were obtained from the renal carcinoma yeast two hybrid library by reverse yeast two hybrid system. RESULTS: 67 positive clones interacting with the bait protein TCF(4) were obtained by reverse yeast two hybrid system, including 18 beta-catenin clones, 24 TCF(4) clones and 25 unknown clones. CONCLUSION: Wnt/Frizzled signaling pathway exists in renal carcinoma. TCF(4), its important signal factor, interacts with beta-catenin and forms homodimer or homocopolymer by itself, thus displaying its constitutive transcriptional activity.

Adenocarcinoma, Clear Cell↗
PubMed2003

[Prevention of postoperative recurrence of human bladder carcinoma by intravesical instillation of immunotoxin, a clinical study].

OBJECTIVE: To observe the effects of intravesical instillation of immunotoxin (IT) on the prevention of recurrence of bladder carcinoma. METHODS: 128 patients with superficial bladder carcinoma or bladder carcinoma of T2 stage underwent operation, and then were randomly divided into 3 groups 2 - 3 weeks after operation to be instilled intravesically with solution of mitomycin (n = 53), Calmette-Guerin vaccine (n = 30), or IT (n = 45) once a week for 8 weeks and then once every month for 8 months respectively. Cystoscopy, blood routine examination, routine urine examination, and liver function test were conducted every 3 months. Immunohistochemistry was used to examine 30 samples of resected carcinoma. The effects and side effects were observed. Recurrence was verified by cystoscopy and/or ultrasonography, CT, and surgery. RESULTS: Out of the 30 samples of resected bladder carcinoma, 27 were staining positive (+ - + + +) with a positive rate of 90%. The binding activity was significantly different between the G(1) carcinoma of and the G(3) carcinoma (P < 0.05) and not significantly different between the G(1) and G(2) carcinomas and between the G(2) and G(3) carcinomas (both P > 0.05). The higher the grade of carcinoma, the stronger the binding activity of IT (P < 0.05). The recurrence rate in the first year were 11.1%, 10.0%, and 15.1% in the IT, BCG, and MMC groups respectively without significant difference between any 2 groups (all P > 0.05); and the recurrence rate in the 2nd year were 24.4%, 30.0%, and 28.3% in the 3 groups respectively without significant difference between any 2 groups (all P > 0.05). The side effect rate were 17.8% on the IT group, significantly lower than those in the other 2 groups (70.0% and 56.6% respectively, both P < 0.01). However, the side effect rates between the BCG group and MMC group was not significantly different (P > 0.05). CONCLUSION: IT is more effective on the prevention of recurrence of carcinomas with higher malignancy and has fewer side effects. The short-term effect of IT is similar to those of BCG and MMC. The activity of IT is associated with the grade and not the stage of carcinoma.

Administration, Intravesical↗
PubMed2003

[Construction and screening of suppression subtractive hybridization library of renal cell carcinoma].

OBJECTIVE: To construct and screen the suppression subtractive hybridization (SSH) library of human renal cell carcinoma (RCC). METHODS: Poly A(+) RNA was isolated from RCC lines 786-O (tester) and renal cell (RC) lines HK-2 (driver), respectively. SSH procedure was performed according to the protocol of the PCR-Select cDNA Subtraction Kit (Clontech), and PCR products were cloned into pT-Adv vector and transformed E. coli TOP10F'. All positive clones picked out were digested and some of which were sequenced. RESULTS: The SSH library contained 362 clones with SSH cDNA fragments distributed mainly from 0.3 to 0.9 kb. Among 50 clones sequenced randomly, 2 represented unknown genes and the other 48 derived from 36 known genes. CONCLUSION: The quality of the SSH library of human RCC is reliable and its construction is the basis for further screening differentially expressed genes of RCC.

Adenocarcinoma, Clear Cell↗
PubMed2003

[Expression and significance of clusterin in normal prostate, benign prostate hyperplasia and prostate cancer].

OBJECTIVE: To investigate the expression and significance of Clusterin in normal prostate, benign prostate hyperplasia (BPH) and prostate cancer. METHODS: Clusterin expression in samples of 12 normal prostate, 15 BPH, and 56 prostate cancer were studied by immunohistochemical stain. RESULTS: Of 83 cases, 67 are positive or weak positive (81%). The rate of positive or weak positive for normal prostate, BPH and prostate cancer was 17% (2/12), 73% (11/15), and 96% (54/56) respectively. The expression level of Clusterin in prostate cancer was much higher than in normal prostate (t = 8.82, P < 0.01). BPH (t = 7.63, P < 0.01) was related positively with pathological grade (r = 0.649, P < 0.01) and stage (r = 0.609, P < 0.01) of prostate cancer. CONCLUSION: Clusterin may play an important role in the biological characteristics of prostate cancer by the anti-apoptosis pathway.

Apoptosis↗
PubMed2003

[Multivariate analysis of recurrence in T1 bladder transitional cell carcinoma].

OBJECTIVE: To investigate the prognostic value of some clinicopathologic indexes and biologic tumor markers in predicting recurrence in T1 transitional cell carcinoma (TCC) of the bladder. METHODS: The expressions of p53, E-cadherin and VEGF of 75 patients with T1 primary bladder TCC were detected by streptabitin peroxidase (SP) immunohistochemical methods. The effects of clinicopathologic indexes and biologic tumor markers on recurrence were assessed by Kaplan-Meier and Cox proportional hazards model. RESULTS: The 1-, 3-, and 5-year recurrence- free survival rates were 68.0%, 45.3% and 20.9%. In Kaplan-Meier analysis, tumor mutifocality and the expression of p53, E-cadherin and VEGF were associated with recurrence. In multivariate analysis, the independent recurrence variables were tumor mutifocality, the expression of p53 and E-cadherin. CONCLUSION: Tumor mutifocality and the abnormal expression of p53 and E-cadherin are the variables that independently predict recurrence in T1 transitional cell carcinoma of the bladder.

Adult↗
PubMed2003

[Impact of short-term neoadjuvant hormonal treatment on neuroendocrine differentiation in prostate carcinoma].

OBJECTIVE: To study the impact of short-term neoadjuvant hormonal treatment on neuroendocrine (NE) differentiation and the relation of NE differentiation and tumor regression. METHODS: The radical prostatectomy specimens and the biopsy specimens of the same 18 patients with prostate cancer were compared. The effect of hormonal treatment on NE-differentiation was evaluated by specific antibodies against chromogranin A (ChA) and serotonin (5-HT). RESULTS: The ChA-positive cell count was 3.2 x 10(-5)/microm(2) [(0-5.7) x 10(-5)/microm(2)] before hormonal treatment and 2.3 x 10(-5) microm(2)[(0-6.6) x 10(-5)/microm(2)] afterward (P > 0.05). For the proportion of NE-positive tumor, it was 7.0% (0%-14.9%) and 4.5% (0%-13.1%) (P > 0.05). No correlation existed between NE-differentiation and the neoadjuvant hormonal treatment. The NE cell density did not differ significantly between 12 non-/slightly regressive tumor foci and 6 highly regressive ones (P > 0.05). CONCLUSION: Short-term neoadjuvant hormonal therapy does not induce clonal propagation of NE cells. The degree of tumor regression following short-term neoadjuvant hormonal therapy is not correlated with the NE differentiation.

Aged↗
PubMed2002

[Screening of novel genes differentially expressed in human renal cell carcinoma by suppression subtractive hybridization].

BACKGROUND AND OBJECTIVE: Identifying the differentially expressed genes in renal cell carcinoma (RCC) contributes to the elucidation of its genetic basis. However, the above knowledge has not yet been fully understood. The aims of this experiment were to screen novel genes differentially expressed in RCC tissues by suppression subtractive hybridization (SSH) and clone RCC-specific related genes. METHODS: To construct SSH library of RCC by using the mRNA from RCC tissues and matched normal kidney tissues as tester and driver, respectively. Partial positive clones in the library were selected randomly and sequenced, then analyze the sequences with the BLAST software. To confirm the location of the fragments of interest in human chromosome through comparing their sequences with the human genome draft. mRNA levels of the novel genes in RCC and matched normal kidney tissues were determined by Northern blot and semi-quantitative RT-PCR analysis. RESULTS: The SSH library contained 414 positive clones. Random analysis of 280 clones with enzyme restriction showed that 265 clones contained cDNA fragments distributed mainly between 300-900bp. Among 80 arbitrary clones with were derived from above 265 clones and sequenced, No. 28, 158, 170, and 249 clones are previously unknown genes and located in human chromosome 21q22, 4p15.3, 9q34, and 22q11.2 by electronic mapping, respectively. The consequence of semi-quantitative RT-PCR demonstrated that mRNA levels of the two novel genes were overexpressed in RCC compared to matched normal tissues by more than 2-6 folds. Northern blot analysis confirmed the above results. CONCLUSIONS: SSH is a reliable strategy for screening novel genes differentially expressed in RCC. The novel gene fragments can be used to clone their full length and further to study their functions.

Blotting, Northern↗