The incidence of consecutive manifestations in Von Hippel-Lindau disease.

Von Hippel-Lindau (VHL) disease is an autosomal dominant rare tumor syndrome characterized by high penetrance. VHL mutation carriers develop numerous manifestations in multiple organs during life. The natural course of development of new and growth of existing VHL-related manifestations is still unclear. In this study we aimed to gain insight into the development of subsequent manifestations in VHL disease. We retrospectively scored each new VHL-related manifestation as detected by standard follow-up (retina, central nervous system, kidneys and pancreas, excluding adrenal and endolymfatic sac manifestations) in 75 VHL mutation carriers. The Kaplan-Meier method was used to plot the cumulative proportions of all consecutive manifestations in each organ against age. The cumulative average number of manifestations in all organs during life was calculated by summating these cumulative proportions. Poisson model parameters were used to calculate average time to the detection of consecutive VHL manifestations in each organ. Consecutive VHL-related kidney and retina manifestations during life occur linearly according to Poisson distribution model. The total number of VHL manifestations rises linearly, with an average of seven VHL-related lesions at age 60 years. The incidence of consecutive VHL-related manifestations is constant during life in VHL mutation carriers. Our data is consistent with the notion that somatic inactivation of the remaining allele (Knudson's "two-hit" hypothesis) is the determining factor in developing new VHL-related manifestations.

Difference in CXCR4 expression between sporadic and VHL-related hemangioblastoma.

Central nervous system hemangioblastomas occur sporadically and in patients with von Hippel-Lindau (VHL) disease due to a VHL germline mutation. This mutation leads to enhanced transcription of chemokine receptor 4 (CXCR4), its ligand (CXCL12) and vascular endothelial growth factor A (VEGFA). We aimed to determine in VHL-related and sporadic hemangioblastomas CXCR4, CXCL12, and VEGFA protein expression and to correlate this to hemangioblastoma size and expression in normal surrounding tissue. 27 patients with a hemangioblastoma were included for analysis of immunohistochemistry of tissue, MRI and DNA. Hemangioblastomas overexpress CXCR4, CXCL12, and VEGFA compared to normal surrounding tissue. In sporadic hemangioblastomas the mean percentage of CXCR4 positive hemangioblastoma cells was 16 %, SD 8.4, in VHL-related hemangioblastomas 8 %, SD 4.4 (P = 0.002). There was no relation between preoperative tumor size and CXCR4 or CXCL12 expression. Compared to normal surrounding tissue CXCR4, CXCL12, and VEGFA were overexpressed in hemangioblastomas. Most interestingly, sporadic hemangioblastomas overexpress CXCR4 compared to VHL-related hemangioblastoma.

Calculating optimal surveillance for detection of von Hippel-Lindau-related manifestations.

von Hippel-Lindau (VHL) mutation carriers develop benign and malignant tumors, requiring regular surveillance. The aim of this study was to calculate the optimal organ-specific age to initiate surveillance and optimal intervals to detect initial and subsequent VHL-related manifestations. In this study, we compare these results with the current VHL surveillance guidelines. We collected data from 82 VHL mutation carriers in the Dutch VHL surveillance program. The cumulative proportion of carriers diagnosed with a first VHL-related manifestation was estimated by the Kaplan-Meier method. The Poisson distribution model was used to calculate average time to detection of the first VHL-related manifestation and subsequent manifestations. We used this to calculate the optimal organ-specific age to initiate surveillance and the surveillance interval that results in a detection probability of 5%. The calculated organ-specific ages to initiate surveillance were 0 years (birth) for adrenal glands, 7 years for the retina, 14 years for the cerebellum, 15 years for the spinal cord, 16 years for pancreas, and 18 years for the kidneys. The calculated surveillance intervals were 4 years for the adrenal glands, biennially for the retina and pancreas, and annually for the cerebellum, spinal cord, and kidneys. Compared with current VHL guidelines, the calculated starting age of surveillance was 6 years later for the retina and 5 years earlier for adrenal glands. The surveillance intervals were two times longer for the retina and four times longer for the adrenal glands. To attain a 5% detection probability rate per organ, our mathematical model indicates that several modifications of current VHL surveillance guidelines should be considered.

A review on CXCR4/CXCL12 axis in oncology: no place to hide.

Classical chemotherapeutic anti-cancer treatments induce cell death through DNA damage by taking advantage of the proliferative behaviour of cancer cells. The more recent approach of targeted therapy (usually protein-targeted) has led to many treatments that are currently available or are under development, all of which are designed to strike at the critical driving forces of cancer cells. The interaction of the cancer cells with their microenvironment is one of these fundamental features of neoplasms that could be targeted in such cancer treatments. Haematological and solid tumour cells interact with their microenvironment through membrane chemokine receptors and their corresponding ligands, which are expressed in the tumour microenvironment. Important representatives of this system are the chemokine ligand CXCL12 and its receptor chemokine receptor 4 (CXCR4). This interaction can be disrupted by CXCR4 antagonists, and this concept is being used clinically to harvest haematopoietic stem/progenitor cells from bone marrow. CXCR4 and CXCL12 also have roles in tumour growth and metastasis, and more recently their roles in cancer cell-tumour microenvironment interaction and angiogenesis have been studied. Our review focuses on these roles and summarises strategies for treating cancer by disrupting this interaction with special emphasis on the CXCR4/CXCL12 axis. Finally, we discuss ongoing clinical trials with several classes of CXCR4 inhibitors, and their potential additive value for patients with a (therapy resistant) malignancy by sensitising cancer cells to conventional therapy.

CXCR4 inhibition with AMD3100 sensitizes prostate cancer to docetaxel chemotherapy.

Several in vitro and in vivo models have revealed the key role of CXCR4/CXCL12 axis in tumor-stroma interactions. Stromal cells present in the tumor microenvironment express high levels of CXCL12 protein, directly stimulating proliferation and migration of CXCR4-expressing cancer cells. This specific prosurvival influence of stromal cells on tumor cells is thought to protect them from cytotoxic chemotherapy and is postulated as a possible explanation for the minimal residual disease in hematological and solid cancers. Therefore, CXCR4/CXCL12 signaling is an attractive therapeutic target in cancer, as proven in preclinical leukemia mouse models, where CXCR4 inhibition sensitized cancer cells to conventional chemotherapy. This study investigates whether inhibition of CXCR4 with the specific inhibitor AMD3100 sensitizes human prostate cancer cells to docetaxel. We showed that both mouse and human stromal cell lines have a protective effect on PC3-luc cells by promoting their survival after chemotherapy. Furthermore, we demonstrated that AMD3100 sensitizes PC3-luc cells to docetaxel. In a subcutaneous xenograft mouse model of human prostate carcinoma, we showed that a combination of docetaxel and AMD3100 exerts increased antitumor effect compared with docetaxel alone. We concluded that CXCR4 inhibition chemosensitizes prostate cancer cells, both in vitro and in vivo. To explore the relevance of these findings, we analyzed CXCR4 expression levels in human prostate cancer samples. We found that cancer cells present in bone metastatic lesions express higher CXCR4 levels relative to the cells present in primary tumors and lymph node metastatic lesions. These findings underscore the potential of CXCR4 inhibitors as chemosensitizing agents.

Pregnancy-related hemangioblastoma progression and complications in von Hippel-Lindau disease.

OBJECTIVE: We studied the reciprocal effect of pregnancy and von Hippel-Lindau (VHL) disease by analyzing the influence of pregnancy on VHL disease-related lesions and VHL disease on pregnancy outcome. METHODS: Medical charts and imaging reports from the VHL disease expertise centers in the Netherlands were used to retrospectively assess lesion progression score before and after pregnancy and to obtain data on pregnancy outcome and VHL disease-related lesions. The Friedman test was used for analysis (p ≤ 0.05). Twenty-nine patients were studied (48 pregnancies, 49 newborns). RESULTS: The progression score of cerebellar hemangioblastomas significantly changed between the single MRI scan before and the 2 scans after pregnancy (p = 0.049) (n = 12). Fetal mortality rate was 2% (n = 1) caused by maternal pheochromocytoma. Maternal VHL disease-related complications occurred in 17% (n = 8) of all pregnancies. In 4 patients, a life-threatening situation emerged: hydrocephalus due to cerebellar hemangioblastoma (n = 2) and pheochromocytoma (n = 2). CONCLUSIONS: Pregnancy in patients with VHL disease induces cerebellar hemangioblastoma progression and causes a high VHL disease-related pregnancy complication rate. We recommend intensified surveillance of patients with VHL disease, especially of cerebellar hemangioblastomas during preconception care and pregnancy.

Role of chemokines and their receptors in cancer.

Metastases are the cause of 90% of human cancer deaths. The current treatment of cancer with chemo,- and/or radiotherapy is based on cell death by DNA damage neglecting the fact that cancer cell invasion into surrounding tissues and metastasizing are fundamental features of neoplasms and the major reason for treatment failure. Metastasis is the result of several sequential steps and represents a highly organized, non-random, and organ-selective process. A number of in vitro and in vivo models show that tumor cells use chemokine-mediated mechanisms during this metastasizing process, comparable to those observed in the regulation of leukocyte trafficking. Furthermore, chemokines modulate tumor behavior such as the regulation of tumor-associated angiogenesis, activation of host tumor-specific immunological responses, and direct stimulation of tumor cell proliferation in an autocrine fashion. These findings may lead to new drugs that target chemokines or their receptors and will likely be of great additional value for treatment of cancer patients.