Xianghui Ning

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.

Shorter telomere length increases age‐related tumor risks in von Hippel‐Lindau disease patients

Von Hippel‐Lindau (VHL) disease is a rare autosomal dominant cancer syndrome caused by alterations of VHL gene. Patients are predisposed to develop pheochromocytomas and solid or cystic tumors of the central nervous system, kidney, pancreas, and retina. Remarkable phenotypic heterogeneity exits in organ involvement and tumor onset age between and within VHL families. However, no reliable markers have been found to predict the age‐related tumor risks in VHL patients. A large Chinese cohort composed of 300 VHL patients and 92 healthy family controls was enrolled in our study. Blood relative telomere length was measured in 184 patients and all the controls available for genomic DNA samples. Age‐related risks for the five major VHL‐associated tumors were evaluated using Kaplan–Meier plots and Cox regression analysis. Differences in clinical phenotype were observed between Chinese cohort and the United Kingdom cohort. VHL patients showed significantly shorter telomere length than healthy family controls(P = 0.0183), and a positive correlation was found between telomere length and onset age of the five major tumors, respectively. Moreover, patients in the shorter telomere group (age‐adjusted telomere length ≤ 0.44) suffered higher age‐related risks for VHL‐associated central nervous system hemangioblastomas (HR: 1.879, P = 0.004), renal cell carcinoma (HR: 2.126, P = 0.002) and pancreatic cyst and neuroendocrine tumors (HR: 2.093, P = 0.001). These results indicate that blood shorter telomere length is a new biomarker for age‐related tumor risks in VHL patients, which will be crucial to genetic counseling and future research about the role of telomere shortening in the pathogenesis of VHL‐associated tumors.

Novel germline mutations in FLCN gene identified in two Chinese patients with Birt–Hogg–Dubé syndrome

Birt–Hogg–Dubé (BHD) syndrome, a hereditary renal cancer syndrome caused by mutations in the folliculin (FLCN) gene, is characterized by the presence of fibrofolliculomas, pulmonary cysts, spontaneous pneumothorax, and renal cell carcinoma (RCC). Few BHD syndrome cases have been reported in Asian countries, and cutaneous presentations are relatively rare in Asian patients. Asian BHD patients may be misdiagnosed due to their atypical manifestations. Here, we report two Chinese BHD patients with novel FLCN mutations (c.946-947delAG in exon 9 and c.770-772delCCT in exon 7). Both of them had RCC and spontaneous pneumothorax without fibrofolliculomas. In patients with RCC and pulmonary cysts but without cutaneous lesions, screening for mutations in the FLCN gene should be performed, especially for those with a family history of RCC or pulmonary cysts (pneumothorax).

Clinicopathologic Features and Prognosis of Sporadic Bilateral Renal Cell Carcinoma: A Series of 148 Cases

Micro‐Abstract Sporadic bilateral renal cell carcinoma (RCC) is relatively rare in RCC. Sporadic bilateral RCC is a distinct subtype and has different biological behaviors compared with hereditary bilateral RCC. The latter occurrence does not bear a significantly worse pathologic biology in metachronous bilateral RCC. The prognosis of patients with sporadic bilateral RCC is comparable with that of patients with unilateral RCC. Introduction: The purpose of this study was to investigate the clinicopathologic features, treatment, and prognosis of sporadic bilateral renal cell carcinoma (RCC). Patients and Methods: A total of 148 patients with sporadic bilateral RCC treated in our center from June 1986 to December 2015 were included in this retrospective study. Their clinicopathologic features and treatments were evaluated. The survival and prognostic factors were assessed based on data from follow‐up. Results: The median age was 54 years (range, 31‐78 years). There were 88 patients with synchronous bilateral RCC and 60 with metachronous bilateral RCC. The median interval between bilateral tumors of metachronous bilateral RCC was 75.5 months. There was no significant difference in tumor size, nuclear grade, or T stage between metachronous tumors (P = .385, P = .544, and P = .263, respectively). Of 148 patients, 124 patients underwent bilateral surgery, 16 underwent unilateral surgery, and 8 patients did not undergo surgery. Of the 317 tumors with pathologic results, 297 (93.7%) were clear‐cell subtype. A total of 136 (91.9%) patients were followed‐up, and the median follow‐up period was 77 months (range, 2‐398 months). During follow‐up, 38 (27.9%) patients died. The 5‐year overall survival rate was 85.9%. The median survival time of patients with no surgery was 5 months. Older age (P = .001), bilateral nonoperative treatment (P < .001), higher T stage (P < .001), and multifocality (P = .02) were related to worse prognosis in multivariate analysis. Conclusion: In metachronous bilateral RCC, the latter occurrence does not bear a significantly worse pathologic biology. The prognosis of sporadic bilateral RCC with no surgery is poor. The overall oncologic results of patients with sporadic bilateral RCC are comparable with that of patients with unilateral 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.

PD52-10 SHORTER TELOMERE LENGTH INCREASES AGE-RELATED TUMOR RISKS IN CHINESE VON HIPPLE-LINDAU DISEASE

incidents that had occurred up until 2015 were documented. Patient demographics and comorbidities were analyzed for risk factors for VTE. All VTE incidents were documented in adjunct with known risk factors for each patient. RESULTS: Of the 900 patients that were evaluated, 10 were documented to have VTE, making the incidence 1.1%. 40% of these patients had a prior history of VTE. 20% of the patients with a VTE had metastatic disease at time of surgery. 90% of patients were obese with a mean BMI of 32.3. 50% of patients with postoperative VTE had tobacco use. 100% of patients with documented VTE had at least 1 risk factor for VTE while 80% of patients had greater than 2 risk factors. CONCLUSIONS: VTE incident following renal cell carcinoma surgery was found to be 1.1%. All patients had at least one risk factor in addition to surgery. The rate of significant postoperative bleeding following surgical therapy for renal cell carcinoma requiring transfusion is noted to be 3-6%. Risks of postoperative bleeding and other complications outweigh the benefit pharmacological VTE may have with such a low incidence of VTE. Early ambulation and mechanical VTE prophylaxis are warranted following surgery. Although VTE was a rare event, those with multiple risk factors may warrant special consideration and more aggressive VTE prophylaxis following surgery.