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Kan Gong

Publications and source records attributed to Kan Gong.

15 recordsLinked to original sources
PubMed2006

Coexpression of erythopoietin and erythopoietin receptor in sporadic clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (CCRCC) is the most common renal carcinoma and it is often associated with von Hippel-Lindau disease (VHL) gene mutations. CCRCCs with VHL mutations demonstrate hypoxia-inducible factor (HIF) overexpression as well as increased expression of vascular endothelial growth factor (VEGF). Recently, the erythropoietin (Epo) has been found to be upregulated in renal and other tumors associated with VHL disease. Furthermore, Epo and Epo receptor (EpoR) coexpression has also been reported in these tumors. The results provided strong evidence that an autocrine loop is involved in tumorigenesis in VHL disease. We investigated whether Epo and EpoR coexpression also occurs in sporadic CCRCC. Fifty-four sporadic CCRCCs were analyzed. VHL gene mutations were detected in 30 out of 54 tumors. Coexpression of Epo and EpoR was detected in 50 out of 54 tumors regardless of their VHL mutation status. The results suggest that coexpression of Epo and EpoR plays an important role in tumorigenesis of sporadic CCRCC.

Adenocarcinoma, Clear Cell↗
PubMed2006

[Expression of hypoxia-inducible factor-1-alpha, hypoxia-inducible factor-2alpha and vascular endothelial growth factor in sporadic clear cell renal cell renal cell carcinoma and their significance in the pathogenesis thereof].

OBJECTIVE: To investigate the expression of hypoxia-inducible factor (HIF)-1-alpha, HIF-2alpha, and vascular endothelial growth factor (VEGF) in sporadic clear cell renal cell carcinoma (CCRCC) and to analyze the relationship among them. METHODS: Samples of CCRCC were obtained from 107 patients during resection. Immunohistochemistry was used to detect the expression of HIF-1-alpha, HIF-2alpha, and VEGF in the tumor tissues and normal kidney tissues distant from the tumor. The microvessel density (MVD) was observed by microscopy. RESULTS: HIF-1-alpha and HIF-2alpha were not expressed in the normal kidney tissues. However, in the tumor tissues the HIF-1-alpha positive rate was 69.2% (74/107), significantly lower than that of the HIF-2-alpha (80.5%, 88/107, P = 0.001), the VEGF positive rate was 78.5% (84/107). The VEGF positive rate of the HIF-1-alpha-positive group was 90.5%, significantly higher than that of the HIF-1-alpha-negative group (51.5%, P = 0.001). The VEGF positive rate of the HIF-2-alpha-positive group was 89.8%, significantly higher than that of the HIF-1-alpha-negative group (26.3%, P = 0.001). The MVD of the 64 HIF-1alpha, HIF-2alpha, and VEGF positive samples was 697, significantly higher than that of the 13 HIF-1alpha, HIF-2alpha, and VEGF negative samples (391, P = 0.001). The MVD of the HIF-2alpha positive samples was 678 +/- 324, significantly higher than that of the HIF-2alpha negative samples (383 +/- 293, P = 0.001). The MVD of the VEGF positive samples was 692 +/- 325, significantly higher than that of the VEGF negative samples (384 +/- 269, P = 0.001). Spearman correlation analysis showed that MVD was strongly positively correlated with HIF-2alpha and VEGF. Mann-Whitney U test showed that HIF-1alpha and HIF-2alpha were not correlated with the staging of CCRCC. CONCLUSION: HIF-2alpha is expressed more frequently in sporadic CCRCC than HIF-1alpha. Both HIF-1alpha and HIF-2alpha upregulate the VEGF expression and angiogenesis, especially HIF-2alpha.

Adult↗
PubMed2006

[Treatment and prognosis of scrotal extramammary Paget's disease: a report of 23 cases].

OBJECTIVE: To evaluate the clinical manifestation, management and prognostic characteristics of scrotal extramammary Pagets disease (EMPD). METHODS: Twenty-three cases of EMPD were identified and retrospectively reviewed, and the clinical findings, surgical treatment, pathologic features and prognostic characteristics were evaluated. The patients ranged in age from 49 to 72 years (mean 62. 4 years). The diagnoses were delayed by 12 to 132 months (67. 6 on average) in 9 cases at Stage A1 , 12 at A2, 1 at B and 1 at D. The rate of initial misdiagnosis was 91.3% (21/23). Twenty of the patients underwent operations, 2 received radiotherapy and 1 chemotherapy. RESULTS: Twenty-two patients of the total number were followed up for 7 to 223 months, averaging at 119, therapy and 1 chemotherapy. of whom 12 remained cancer free, 1 died of tumor, 3 died of intercurrent disease, 4 experienced local recurrence, 1 relapsed with inguinal lymph node metastasis and 1 developed inguinal lymph node metastasis exclusively. Those with relapses received the second surgery, and 5 of them survived without cancer and 1 died of intercurrent disease. CONCLUSION: The primary treatment of choice for scrotal EMPD is radical excision. Precise, histological examination before and during the operation is of crucial importance. The positive excisal margins are one of the key causes of local recurrence, and the involvement of dermis by Pagets cells may suggest possible metastasis. Scrotal EMPD tends to occur as a slowly growing lesion, mainly in the elderly, and has a good prognosis in cases of non-invasion. Otherwise the prognosis is poor.

Aged↗
PubMed2005

[The expression of hypoxia inducible factor-1,2 alpha in sporadic clear cell renal cell carcinoma and their relationships to the mutations of von Hippel-Lindau gene].

OBJECTIVE: To evaluate the expression of hypoxia inducible factor (HIF)-1alpha, 2alpha in sporadic clear cell renal cell carcinoma and their relationships to the mutations of von Hippel-Lindau (VHL) gene. METHODS: Mutations of VHL gene, expression of HIF-1alpha and 2alpha were detected by polymerase chain reaction (PCR), direct DNA sequencing and immunohistochemistry in 77 cases of Chinese sporadic clear cell renal cell carcinoma (CCRCC). The stage was pT(1)N(0)M(0)in 55 patients (71%), pT(2)N(0)M(0) in 7 patients (9%), pT(3)N(0)M(0) in 14 patients (18%), and pT(4)N(0)M(0) in 1 patient (1%). The classification according to the tumor nuclear grading system showed 15 carcinomas (19%) of tumor nuclear grade 1, 56 (73%) of tumor nuclear grade 2 and 6 (8%) of tumor nuclear grade 3. RESULTS: None of the VHL gene mutations were found in all the normal tissue specimens. VHL gene mutations were detected in 40 (52%) cases of CCRCC. The positive rate of HIF-2alpha (81%) was higher than that of HIF-1alpha (66%) (chi(2) = 23.310, P < 0.01); The positive rate of HIF-1alpha and HIF-2alpha in the cases of mutations (98% and 93% respectively) was higher than that of them in non-mutations (32% and 68% respectively) (chi(2) = 36.386, 7.617, P < 0.01); The correlation between HIF-1alpha and VHL gene mutations was closer than that between HIF-2alpha and VHL gene mutations (partial correlation coefficiency was 4.481 and 2.027 respectively, P < 0.01). The expression of HIF-1alpha and 2alpha in different pathological grade and stage of CCRCC showed no significant difference (P > 0.05). CONCLUSIONS: Our study suggests that VHL gene mutations are frequent in sporadic CCRCC, and the high expression of HIF-1alpha and 2alpha are found in the group of VHL mutations. However, we have not found significant correlation between the expression of HIF-1alpha and 2alpha and pathological grade and stage of CCRCC in our study.

Adult↗
PubMed2005

[Analysis of biallelic inactivation of the von Hippel-Lindau tumor suppressor gene VHL in patients of renal cell carcinoma patient].

OBJECTIVE: To investigate biallelic inactivation of the von Hippel-Lindau tumor suppressor gene (VHL) in patient of renal cell carcinoma (RCC) patient. METHODS: We extracted tumor and normal DNA from 41 RCC patients. Mutation of VHL gene from tumor tissue was detected from tumor tissue by polymerase chain reaction (PCR) and direct sequencing. Two single nucleotide polymorphism (SNP) sites located in VHL gene were analyzed by PCR restriction fragment length polymorphism, and loss of heterozygosity (LOH) was analyzed for VHL gene by comparing between tumor with normal tissue. RESULTS: Mutation and LOH of VHL gene was found in 51% (21/41) and 42% (8/19) of RCC patients respectively. LOH was highly associated with mutation positive tumors (r = 0.78) and VHL biallelic inactivation was detected in 37% of RCC patients. CONCLUSION: Biallelic inactivation of VHL gene occurs in RCC due to VHL mutation and LOH, and its frequency rate is 37%.

Adult↗
PubMed2005

[Analysis of two single nucleotide polymorphisms in von Hippel-Lindau gene and detection of loss of heterozygosity in Chinese sporadic renal cell carcinoma].

OBJECTIVE: To exam two single nucleotide polymorphism(SNP) in VHL gene and intragenic loss of heterozygosity (LOH) of VHL gene in 79 Chinese sporadic renal cell carcinomas(RCCs), and to analyze the relationships between VHL LOH and clinicopathological parameters. METHODS: The authors extracted tumor and normal tissue DNA and detected two genotypes of intragenic SNP sites, rs779805 in the 5'terminal and rs 1642742 in the 3'terminal of VHL gene by polymerase chain reaction-restriction frament length polymorphism, then analyzed VHL LOH by comparing tumor tissue versus normal tissue in heterozygosities. Subsequently the relationships between VHL LOH and clinicopathological parameters of RCCs were analyzed. RESULTS: The computed heritage parameters of two SNPs, included genotype frequency, allele frequency, heterozygosity, and polymorphism information content. Twenty-nine heterozygosities were detected in 79 RCCs. LOH was found in 41.4%(12/29) of RCCs. No significant relationships between VHL LOH and age, sex, tumor stage, pathological grade were found. CONCLUSION: LOH of VHL gene is an important genetic event in Chinese sporadic renal carcinoma, and the LOH frequency is 41.4%. VHL LOH has no influence on stage and grade of RCC.

Adult↗
PubMed2005

[Primary artery erectile dysfunction: one case report].

OBJECTIVE: To evaluate the relationship between the deformation of penile artery and the primary artery erectile dysfunction, and to improve the treatment and diagnosis of primary artery erectile dysfunction. METHODS: One case of primary artery erectile dysfunction was presented with its primary clinic data. RESULTS: The dorsal artery of the penis was thin and the bilateral penile arteries were lacking by arteriography. The implantation of a penile prosthesis significantly improved the patient's erectile function. CONCLUSION: The primary artery erectile dysfunction is a relatively rare disease. The possibility of primary artery erectile dysfunction should be kept in mind. Penile prosthesis implantation is an effective means for the treatment of primary artery erectile dysfunction.

Adult↗
PubMed2004

[Mutation of von Hippel-Lindau gene and expression of vascular endothelial growth factor in sporadic clear cell renal cell carcinoma and their relationships to angiogenesis].

OBJECTIVE: To evaluate the relationship between the mutation of the von Hippel-Lindau (VHL) gene and expression of vascular endothelial growth factor (VEGF) in sporadic clear cell renal cell carcinoma (CCRCC) and angiogenesis. METHODS: Polymerase chain reaction (PCR) was used to detect the mutation of VHL gene in the specimens of cancerous tissue and normal tissues away from tumor from 77 patients with CCRCC. Immunohistochemistry was used to examine the expression of VEGF. CD34 staining was used to measure the microvascular density (MVD). RESULTS: VHL gene mutations were detected in 40 cases (51.9%). The expression rate of VEGF was 79.2% (61 cases). The positive rate of VEGF in the cases with VHL mutation was 92.5%, significantly higher than that in the cases without VHL mutation (64.9%, P = 0.003). The levels of MVD was higher in the cases with VHL mutation and those with VEGF expression were 760.80/mm2 and 715.95/mm2 respectively, both significantly higher than those in the cases without VHL-mutation and those without VEGF expression (547.03/mm2 and 437.44/mm2 respectively, all P = 0.001). The cases with expression of VEGF were divided into two groups according the presence or absence of VHL gene mutations or not. The MVD of the cases with VEGF expression and VHL mutation was 760.80 mm2, significantly higher than that of the cases with VEGF expression and without VHL mutation (547.03 mm2, P = 0.011). CONCLUSION: The mutation rate of VHL gene is high among the Chinese with sporadic CCRCC. VHL gene mutation increases significantly the VEGF expression, thus, and perhaps via other mechanism too, promoting the angiogenesis in tumor. The high level of MVD of the cases with VHL gene mutation may be related to the high malignant potential of CCRCC.

Adenocarcinoma, Clear Cell↗
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

[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

[Report of a case of penile epithelioid sarcoma].

OBJECTIVE: To enhance the knowledge and the effect of the diagnosis and treatment of primary epithelioid sarcoma of the penis. METHODS: One rare case of primary epithelioid sarcoma of the penis was studied with regard to its primary clinical process and characteristics, differential diagnosis and method of treatment. RESULTS: An operation was performed on the penis to treat the epithelioid sarcoma. The diagnosis was confirmed by immunohistological and pathological techniques. There was no evidence of relapse during the three-year follow-up after operation. CONCLUSION: The possibility of primary epithelioid sarcoma of the penis should be considered if a mass or induration of the proximal penis and the symptoms of urethremphraxis are found. Total phallectomy could be chosen as an appropriate method of treatment. Unless adenopathy is palpable, node dissections are not recommended.

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

Transurethral electrochemical treatment of benign prostatic hyperplasia.

OBJECTIVE: To study the mechanism and feasibility of transurethral electrochemical therapy for the treatment of benign prostatic hyperplasia (BPH). METHODS: Between March 1998 and March 2000, specifically designed devices and catheters for electrochemical therapy were applied to 6 prostate specimens obtained by suprapubic prostatectomy in order to treat BPH patients with urinary retention for whom surgery was contraindicated. Sixteen patients (with a mean age of 77.3 years old) underwent electrical treatment totaling 160-220 coulombs under topical urethral anesthesia for 68-132 min. The catheters remained inside the patient for 7-10 d. RESULTS: Irreversible destructive changes occurred within cathodal tissue, while carbonization occurred within anodic tissue. The radius of tissue change was 7-8 mm and 1-2 mm, respectively. In vivo trial: 11 (69%) patients could be weaned off the catheters with satisfactory urination. Three months after therapy, the mean international prostate symptom score (IPSS) was 14.5, mean peak flow rate was 10.5 ml/s, and mean residual urine was 39 ml. No serious complications were observed. CONCLUSION: Transurethral electrochemical treatment is potentially a minimally invasive alternative for treatment of BPH, especially for elderly patients at high risk.

Aged↗