Pengjie Wu

The Erythropoietin/Erythropoietin Receptor Signaling Pathway Promotes Growth and Invasion Abilities in Human Renal Carcinoma Cells

Co-expression of erythropoietin (Epo) and erythropoietin receptor (EpoR) has been found in various non-hematopoietic cancers including hereditary and sporadic renal cell carcinomas (RCC), but the Epo/EpoR autocrine and paracrine mechanisms in tumor progression have not yet been identified. In this study, we used RNA interference method to down-regulate EpoR to investigate the function of Epo/EpoR pathway in human RCC cells. Epo and EpoR co-expressed in primary renal cancer cells and 6 human RCC cell lines. EpoR signaling was constitutionally phosphorylated in primary renal cancer cells, 786-0 and Caki-1 cells, and recombinant human Epo (rhEpo) stimulation had no significant effects on further phosphorylation of EpoR pathway, proliferation, and invasiveness of the cells. Down-regulation of EpoR expression in 786-0 cells by lentivirus-introduced siRNA resulted in inhibition of growth and invasiveness in vitro and in vivo, and promotion of cell apoptosis. In addition, rhEpo stimulation slightly antagonized the anti-tumor effect of Sunitinib on 786-0 cells. Sunitinib could induce more apoptotic cells in 786-0 cells with knockdown EpoR expression. Our results suggested that Epo/EpoR pathway was involved in cell growth, invasion, survival, and sensitivity to the multi-kinases inhibitor Sunitinib in RCC cells.

Telomere Shortening Is Associated with Genetic Anticipation in Chinese Von Hippel–Lindau Disease Families

Von Hippel-Lindau (VHL) disease is a rare autosomal dominant cancer syndrome. A phenomenon known as genetic anticipation has been documented in some hereditary cancer syndromes, where it was proved to relate to telomere shortening. Because studies of this phenomenon in VHL disease have been relatively scarce, we investigated anticipation in 18 Chinese VHL disease families. We recruited 34 parent-child patient pairs (57 patients) from 18 families with VHL disease. Onset age was defined as the age when any symptom or sign of VHL disease first appeared. Anticipation of onset age was analyzed by paired t test and the other two special tests (HV and RY2). Relative telomere length of peripheral leukocytes was measured in 29 patients and 325 healthy controls. Onset age was younger in child than in parent in 31 of the 34 parent-child pairs. Patients in the first generation had older onset age with longer age-adjusted relative telomere length, and those in the next generation had younger onset age with shorter age-adjusted relative telomere length (P < 0.001) in the 10 parent-child pairs from eight families with VHL disease. In addition, relative telomere length was shorter in the 29 patients with VHL disease than in the normal controls (P = 0.003). The anticipation may relate to the shortening of telomere length in patients with VHL in successive generations. These findings indicate that anticipation is present in families with VHL disease and may be helpful for genetic counseling for families with VHL disease families and for further understanding the pathogenesis of VHL disease.

Mosaicism in von Hippel–Lindau disease with severe renal manifestations

von Hippel–Lindau (VHL) disease is an inheritable multisystem tumor syndrome characterized by multiple benign and malignant tumors affecting multiple organs. VHL is the result of a germline mutation in the VHL tumor suppressor gene. Molecular genomic analysis routinely confirms the clinical diagnosis. However, the use of molecular diagnostic methods can often be insufficient for the detection of mosaic germline VHL mutations, making the diagnosis of some cases of VHL difficult. Here, we report the case of a VHL mosaic patient with bilateral renal lesions in the absence of other VHL‐associated lesions. A VHL mutation was not originally detected by routine molecular testing. Nonetheless, the detection of a heterozygous c.194C>G (p.Ser65Trp) VHL mutation in the patients daughter prompted further genetic assessment and eventually resulted in the finding of a mosaic c.194C>G (p.Ser65Trp) VHL mutation in the patient. The mutation rate was 18.8 ± 3.84% in peripheral leukocytes. As the frequency of VHL mosaicism remains underdetermined, the possibility of a diagnosis of mosaic VHL should be considered in patients with both typical and atypical VHL‐associated manifestations.

Suppression of renal cell carcinoma growth in vivo by forced expression of vascular endothelial growth inhibitor

Vascular endothelial growth inhibitor (VEGI) has been associated with tumor-related vasculature in certain malignancies. However, its implication in renal cell carcinoma (RCC), an angiogenesis-dependent tumor, remains unknown. In the present study, we investigated the role played by VEGI in RCC. The expression of VEGI was examined in human renal tissue and RCC cell lines using immunohistochemical staining and RT-PCR, respectively. The biological impact of modifying the expression of VEGI in RCC cells was evaluated using in vitro and in vivo models. We show that VEGI mRNA is expressed in a wide variety of human RCC cell lines, all of normal renal and most of RCC tissue specimens. VEGI protein expression was observed in normal renal tubular epithelial cells, but was decreased or absent in RCC specimens, particularly in tumors with high grade. Moreover, forced expression of VEGI led to an inhibition of vascular endothelial tube formation, decrease in the motility and adhesion of RCC cells in vitro. Interestingly, forced expression of VEGI had no bearing on growth, apoptosis and invasive capacity of RCC cells. However, tumor growth was reduced in xenograft models. Immunohistochemical staining showed that microvessel density decreased in VEGI forced expression xenograft tumor samples. Taken together, our findings showed that the expression of VEGI is decreased in RCC, particularly in tumors with higher grade. Together with its inhibitory effect on cellular motility, adhesion, vascular endothelial tube formation and tumor growth in vivo, this suggests that VEGI functions mainly through inhibition of angiogenesis and is a negative regulator of aggressiveness during the development and progression of RCC.

Risk factors for survival in patients with von Hippel-Lindau disease

Background Historically, von Hippel-Lindau (VHL) disease is characterised by a poor survival. Although genotype–phenotype correlation has been described in many studies, the risk factors for VHL survival remain unclear. This study aims to evaluate the median survival of Chinese patients with VHL disease and explore whether VHL survival is influenced by genetic and clinical factors. Methods In this retrospective study, we recruited 340 patients from 127 VHL families. Kaplan-Meier plot and Cox regression model were used to evaluate the median survival and assess how survival was influenced by birth year, birth order, sex, family history, mutation type, onset age and first presenting symptom. Results The estimated median life expectancy for Chinese patients with VHL disease was 62 years. Patients with early-onset age, positive family history and truncating mutation types had poorer overall and VHL-related survival. Patients with haemangioblastoma as their first presenting symptom were related to a higher risk of death from central nervous system haemangioblastoma than those with abdominal lesions (HR 8.84, 95% CI 2.04 to 38.37, P=0.004). Conclusions This largest VHL survival analysis indicates that onset age, family history, mutation type and first presenting symptom have an effect on the survival of patients with VHL disease, which is helpful to genetic counselling and clinical decision-making.

Genotype and phenotype correlation in von Hippel–Lindau disease based on alteration of the HIF-α binding site in VHL protein

PurposeVon Hippel–Lindau (VHL) disease is a rare hereditary cancer syndrome that reduces life expectancy. We aimed to construct a more valuable genotype–phenotype correlation based on alterations in VHL protein (pVHL).MethodsVHL patients (n = 339) were recruited and grouped based on mutation types: HIF-α binding site missense (HM) mutations, non-HIF-α binding site missense (nHM) mutations, and truncating (TR) mutations. Age-related risks of VHL-associated tumors and patient survival were compared.ResultsMissense mutations conferred an increased risk of pheochromocytoma (HR = 1.854, p = 0.047) compared with truncating mutations. The risk of pheochromocytoma was lower in the HM group than in the nHM group (HR = 0.298, p = 0.003) but was similar between HM and TR groups (HR = 0.901, p = 0.810). Patients in the nHM group had a higher risk of pheochromocytoma (HR = 3.447, p < 0.001) and lower risks of central nervous system hemangioblastoma (CHB) (HR = 0.700, p = 0.045), renal cell carcinoma (HR = 0.610, p = 0.024), and pancreatic tumor (HR = 0.382, p < 0.001) than those in the combined HM and TR (HMTR) group. Moreover, nHM mutations were independently associated with better overall survival (HR = 0.345, p = 0.005) and CHB-specific survival (HR = 0.129, p = 0.005) than HMTR mutations.ConclusionThe modified genotype–phenotype correlation links VHL gene mutation, substrate binding site, and phenotypic diversity (penetrance and survival), and provides more accurate information for genetic counseling and pathogenesis studies.

MP60-05 ERYTHROPOIETIN RECEPTOR MAY BECOME A TARGET FOR RENAL CELL CARCINOMA

paired metastatic tumors, and 8 paired normal kidney samples by immunohistochemistry. RESULTS: NF2 mutations are enriched in higher grade (>pT3, pT4) and metastatic tumors compared to low grade or non-metastatic tumors (20-30% vs. 1.5%), and are associated with a decreased disease-free survival. Cell lines derived from metastatic RCC have lower NF2 expression than cell lines derived from local tumors, more importantly, MERLIN protein levels are decreased or undetectable by Western blot or IHC in metastatic derived cell lines. The metastatic lines Caki1 and ACHN have increased metastatic potential as measured by increased colony formation. MERLIN was absent in a tumor with sarcomatoid differentiation but was present in all 8 metastatic samples. CONCLUSIONS: These results support a potential intriguing role for MERLIN loss of function in the clinically-relevant phenotypic transition from localized to invasive RCC. The model system described here will provide a crucial framework for testing MERLIN0s influence on invasiveness through knockdown and rescue of MERLIN activity in appropriate RCC cell lines.

Renal Arterial Pseudoaneurysm and Renal Arteriovenous Fistula Following Partial Nephrectomy

Introduction: Renal arterial pseudoaneurysm (RAP) and renal arteriovenous fistula (RAVF) are rare but can cause fatal bleeding. Materials and Methods: A retrospective review was conducted for patients undergoing partial nephrectomy (PN) in our department. The clinical features and treatment methods were analysed, and the relationships between RAP/RAVF and the surgical methods and R.E.N.A.L. score were investigated. Results: Eleven patients were diagnosed with RAP/RAVF (9 with RAP and 2 with RAVF). The incidence of RAP/RAVF after laparoscopic PN showed no significant difference compared to that after open PN (p = 0.47). A low R.E.N.A.L. score was present in 6 patients, while an intermediate/high score was present in the other 5 patients. The major clinical manifestations included haematuria and haemorrhagic shock, and the median time of occurrence was 8 days after the operation. Six patients underwent an ultrasound examination. Of the 4 patients who underwent enhanced CT, 2 patients were diagnosed with RAP. All 11 patients were diagnosed by renal angiography and were cured after super-selective arterial embolization. The serum creatinine levels before and after embolization showed no significant differences (p = 0.14). Conclusions: RAP/RAVF may not have any relationship with the surgical procedure or R.E.N.A.L. score. Renal angiography and super-selective arterial embolization are the preferred methods for diagnosing and treating RAP/RAVF.

739 CLINICAL CHARACTERISTICS OF VON HIPPEL-LINDAU DISEASE IN CHINESE PATIENTS

cases in 2001 and 44,455 cases in 2010. Benign kidney neoplasm rates (nephrectomy specimen) were 5.3% in 2001 and 4.4% in 2010; malignancy rates were 94.7% in 2001 and 95.6% in 2010. Partial nephrectomy cases increased from 5,607 (2001) to 18,492 (2010). Benign kidney neoplasm rates for partial nephrectomy cases were 16% in both 2001 and 2010, while averaging 17% over the time period. Malignancy rates for partial nephrectomy cases were 84% in both 2001 and 2010. Benign kidney tumor rates (overall) based on gender and age are shown in the Table below.