Complete protection against cryodamage of cryopreserved whole bovine and human ovaries using DMSO as a cryoprotectant.

PURPOSE: This study aims to determine the optimal cryopreservation protocol for whole ovaries intended for preservation of fertility in women. METHODS: We investigated the optimal cryopreservation procedure for whole ovaries in a bovine model. The following parameters were investigated to determine their effect on ovarian tissue viability: type of cryoprotectant, administration route of the cryoprotectant (perfusion and/or submersion), and the maximum tolerable interval between death of the animal and start of the cryopreservation process. The resulting optimal cryopreservation procedure for bovine ovaries was subsequently tested on human ovaries. In vitro glucose uptake, histology, and immunohistochemistry were used to assess the integrity of the ovarian tissue. RESULTS: Starting the cryopreservation procedure (including perfusion with and submersion in DMSO) within 10-15 min after death of the animal proved critical, resulting in a 90-100% protection level against cryodamage. When cryopreserving human ovaries using the same protocol, over 95% protection against cryodamage was observed on all tissue levels. In addition, no apparent morphological damage to either the follicles or the vascular endothelium was observed. CONCLUSION: Our findings suggest that using the optimized protocol presented in this paper allows good cryopreservation of whole human ovaries and represents an important step in considering whole ovary autotransplantation for clinically applied fertility preservation.

Clinically applied procedures for human ovarian tissue cryopreservation result in different levels of efficacy and efficiency.

PURPOSE: Different protocols are being used worldwide for the cryopreservation of human ovarian tissue for fertility preservation purposes. The efficiency and efficacy of the majority of these protocols has not been extensively evaluated, possibly resulting in sub-optimally cryopreserved ovarian tissue. To address the impact of this issue, we assessed the effects of two clinically successful human ovarian tissue slow-freezing cryopreservation procedures on the quality of the cryopreserved tissue. METHODS: To differentiate between cryopreservation (C) versus thawing (T) related effects, four combinations of these two (A and B) very different cryopreservation/thawing protocols (ACAT, ACBT, BCAT, BCBT) were studied. Before and after cryopreservation and thawing, the percentage of living and morphologically normal follicles, as well as the overall tissue viability, was assessed. RESULTS: Our experiments revealed that the choice of the cryopreservation protocol noticeably affected the overall tissue viability and percentage of living follicles, with a higher viability after protocol BC when compared to AC. No statistically significant differences in tissue viability were observed between the two thawing protocols, but thawing protocol BT required considerably more human effort and materials than thawing protocol AT. Tissue morphology was best retained using the BCAT combination. CONCLUSION: Our results indicate that extensive and systematical evaluation of clinically used protocols is warranted.

Angiostatin generating capacity and anti-tumour effects of D-penicillamine and plasminogen activators.

BACKGROUND: Upregulation of endogenous angiostatin levels may constitute a novel anti-angiogenic, and therefore anti-tumor therapy. In vitro, angiostatin generation is a two-step process, starting with the conversion of plasminogen to plasmin by plasminogen activators (PAs). Next, plasmin excises angiostatin from other plasmin molecules, a process requiring a donor of a free sulfhydryl group. In previous studies, it has been demonstrated that administration of PA in combination with the free sulfhydryl donor (FSD) agents captopril or N-acetyl cysteine, resulted in angiostatin generation, and anti-angiogenic and anti-tumour activity in murine models. METHODS: In this study we have investigated the angiostatin generating capacities of several FSDs. D-penicillamine proved to be most efficient in supporting the conversion of plasminogen to angiostatin in vitro. Next, from the optimal concentrations of tPA and D-penicillamine in vitro, equivalent dosages were administered to healthy Balb/c mice to explore upregulation of circulating angiostatin levels. Finally, anti-tumor effects of treatment with tPA and D-penicillamine were determined in a human melanoma xenograft model. RESULTS: Surprisingly, we found that despite the superior angiostatin generating capacity of D-penicillamine in vitro, both in vivo angiostatin generation and anti-tumour effects of tPA/D-penicillamine treatment were impaired compared to our previous studies with tPA and captopril. CONCLUSION: Our results indicate that selecting the most appropriate free sulfhydryl donor for anti-angiogenic therapy in a (pre)clinical setting should be performed by in vivo rather than by in vitro studies. We conclude that D-penicillamine is not suitable for this type of therapy.

Noninvasive Detection of Metastases and Follicle Density in Ovarian Tissue Using Full-Field Optical Coherence Tomography.

PURPOSE: Autotransplantation of ovarian tissue can be used to restore fertility in patients with cancer following gonadotoxic treatment. Whether this procedure is safe remains unclear, as current tumor detection methods render the ovarian tissue unsuitable for transplantation. Full-field optical coherence tomography (FF-OCT) is an imaging modality that rapidly produces high-resolution histology-like images without the need to fix, freeze, or stain the tissue. In this proof-of-concept study, we investigated whether FF-OCT can be used to detect metastases in ovarian tissue, thereby increasing the safety of ovarian tissue autotransplantation. We also evaluated whether cortical ovarian tissue and follicles remain viable following FF-OCT imaging. EXPERIMENTAL DESIGN: Formalin-fixed, paraffin-embedded tissue samples were obtained from seven normal ovaries and fourteen ovaries containing metastases and/or micrometastases. These samples were deparaffinized and imaged using FF-OCT. The FF-OCT images were then compared with corresponding hematoxylin and eosin-stained tissue sections. Finally, we examined the effect of FF-OCT imaging on the viability of ovarian tissues and follicles in fresh bovine ovarian tissue using a glucose uptake and neutral red staining, respectively. RESULTS: FF-OCT illustrated both normal structures and metastases in ovarian tissue within minutes. Primordial follicles were readily identifiable. Finally, tissues and follicles remained viable following FF-OCT imaging for up to 180 and 60 minutes, respectively. CONCLUSIONS: FF-OCT imaging is a promising method for the noninvasive detection of metastases, including micrometastases, in ovarian tissue. Moreover, this method facilitates the selection of cortical ovarian tissue with the highest density of primordial follicles, potentially increasing the likelihood of restoring ovarian function following ovarian tissue autotransplantation. Clin Cancer Res; 22(22); 5506-13. ©2016 AACR.

Decrease in circulating anti-angiogenic factors (angiostatin and endostatin) after surgical removal of primary colorectal carcinoma coincides with increased metabolic activity of liver metastases.

Removal of a primary colorectal tumor resulted in an increase in metabolic activity in its liver metastasis. Concomitantly, levels of angiostatin and endostatin in urine and plasma, respectively, dropped. This finding indicates that the primary tumor suppressed angiogenesis in its distant metastasis, and that removal of the primary lesion caused a flare-up in vessel neoformation and, thus, enhanced metabolic activity in its liver metastasis.

Status of sperm morphology assessment: an evaluation of methodology and clinical value.

OBJECTIVE: To characterize methodological changes in sperm morphology assessment and to correlate sperm morphology with clinical outcome. DESIGN: In this observational study, sperm morphology profiles of patients were analyzed. The percentages of morphologically normal spermatozoa were evaluated with respect to changes in morphology assessment criteria; male aging; and prognostic value for outcomes after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). SETTING: Diagnostic and clinical laboratories. PATIENT(S): A total of 8,846 men who visited the diagnostic laboratory; 133 samples from a sperm bank; and 3,676 IVF/ICSI couples. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The percentage of morphologically normal spermatozoa in semen samples. The regression of the individual morphologically normal cell profiles. The relation between the percentage of normal forms with pregnancy outcome after IVF/ICSI. RESULT(S): The percentage of morphologically normal spermatozoa showed a decrease from roughly 30%-80% in 1984 to 0%-10% since 2004. With added evidence from sperm bank samples, this decrease was found to be attributable mainly to changes in morphology assessment criteria. Furthermore, an intraindividual aging effect of 0.51% per year was observed. A statistically significant relationship was found between decreases in percentage of normal forms and a lower probability of ongoing pregnancies after IVF, although the area under the curve was only 54%. CONCLUSION(S): Methodological changes had a strong effect on the percentage of morphologically normal spermatozoa over the past few decades. In addition, male aging results in decreasing sperm morphology. The percentage of morphologically normal spermatozoa has no prognostic value for individual IVF/ICSI patients.

Technology evaluation: ABT-510, Abbott.

ABT-510 is a small peptide thrombospondin-1 mimetic angiogenesis inhibitor under development by Abbott Laboratories for the potential treatment of solid tumors. ABT-510 is undergoing phase II clinical trials.

Outgrowth of human liver metastases after resection of the primary colorectal tumor: a shift in the balance between apoptosis and proliferation.

Rapid outgrowth of metastases after removal of the primary tumor has been described in several mouse models. Loss of primary tumor-induced inhibition of angiogenesis in the metastases has been suggested as the underlying cause. Accordingly, we recently demonstrated that vascular density in human colorectal liver metastases increases after primary tumor resection. Here, we investigate whether this increase in vascular density has, in its turn, effects on the tumor growth of the liver metastases. We analyzed tumor growth in synchronous liver metastases from patients with the primary tumor in place, in synchronous metastases from patients with the primary tumor resected and in metachronous metastases. Tumor growth was studied by assessing the percentage of cells undergoing apoptosis by activated caspase-3 staining, and the percentage of proliferating cells by Ki-67 staining. While the percentage of proliferating cells within the metastases showed a modest increase after primary tumor resection, a significant decrease in the percentage of apoptotic cells was observed. Taken together, an increased net tumor growth of the metastases occurred after primary tumor resection. This acceleration of tumor growth could be confirmed by studying biopsies taken from the same patient before and after tumor resection. Our data show that in human cancer patients, a primary tumor may inhibit the growth of its liver metastases.

Progressive loss of endothelial P-selectin expression with increasing malignancy in colorectal cancer.

Adhesion of inflammatory cells to vascular endothelium is mediated by specific cell adhesion receptors on both leukocytes and endothelial cells. One of the adhesion molecules on the endothelium is P-selectin. Decreased vascular P-selectin expression has been associated with tumor progression in melanoma patients. We now report on the expression of endothelial P-selectin in colorectal cancer (CRC). We studied a colorectal tissue specimen series ranging from normal colorectal tissue via unmetastasized primary tumors to tumors with the same depth of invasion at the primary site but with liver metastases. Moreover, P-selectin expression levels in liver metastases were determined. The number of P-selectin positive vessels as a fraction of the total number of vessels, both intra- and peritumorally, was determined by staining for CD62P and CD34, respectively. Furthermore, by immunostaining for leukocytes (CD45) and macrophages (CD68), it was evaluated whether levels of P-selectin expression influenced infiltrate density and composition. The results showed that levels of peritumoral P-selectin expression were reciprocal to the degree of progression in CRC. This relation was even more pronounced intratumorally: in metastasized primary tumors and in the metastatic lesions, P-selectin expression was virtually absent. This distribution pattern was reflected in the numbers of leukocytes that accumulated in the various tissues, since in the primary tumors with metastases, and in the metastatic lesions, hardly any infiltrating cells were observed. In these lesions, leukocytes were present in the peritumoral zone, but seemed unable to enter the tumor tissue. In primary tumors without metastasis, the intratumoral leukocyte infiltration density was significantly higher. Recruitment levels of macrophages remained constant throughout the different tissues. We suggest that downregulation of endothelial P-selectin expression is a mechanism by which CRC lesions evade inflammatory regression and, thereby, progress to a more advanced stage of malignancy.

The angiopoietin-like factor cornea-derived transcript 6 is a putative morphogen for human cornea.

The human cornea-specific protein cornea-derived transcript 6 (CDT6) is a member of the angiopoietin gene family. We report the structural and functional characterization of CDT6. We demonstrate that CDT6 is a secreted protein that folds into disulfide-linked homotetramers by coiled-coil interactions. The finding that CDT6 is expressed at high levels in the avascular corneal stromal layer suggested that the protein, similar to certain angiopoietins, acts as a negative regulator of angiogenesis. To test this hypothesis and to assay the effect of the protein on a growing tissue with high vascular density, CDT6 was expressed in a mouse xenograft model. Expression of CDT6 led to a reduction in tumor growth and aberrant blood vessel formation by inducing massive fibrosis. Interestingly, expression of CDT6 also resulted in the deposition of extracellular matrix components typical for the mature corneal stromal layer. These observations strongly suggest a role as morphogen for CDT6 in inducing a corneal phenotype in vivo.

Vascular density in colorectal liver metastases increases after removal of the primary tumor in human cancer patients.

In animal models, explosive growth of metastases after removal of the primary tumor has been attributed to abolishment of angiogenesis inhibition. We investigated the influence of (removal of) the primary tumor on vascularization of liver metastases in human colorectal cancer patients. We analyzed vascular density in synchronous liver metastases from patients with the primary tumor in situ, in synchronous metastases from patients with the primary tumor resected and in metachronous metastases. In a limited number of cases, biopsies from metastases from the same patient before and within 3 months after resection were analyzed. In addition, vascular density in metastases was compared to the vascular density in the corresponding primary tumor. Peritumoral and intratumoral vascular density were determined by staining for endothelial antigens CD31 and CD34, respectively. Both peritumoral and intratumoral vascular density were elevated in synchronous metastases from patients with the primary tumor removed compared to synchronous metastases from patients with the primary tumor in situ. Comparable results were observed in patients with metachronous metastases. An increase in vascular density after resection of the colorectal malignancy was also observed in biopsies taken from the same patient before and after tumor resection. Remarkably, vascular density in the liver metastases was always lower than that in the corresponding primary tumor. Our data show for the first time in humans that the presence of a primary tumor is correlated with decreased vascularization of its distant metastases. Resection of the primary tumor results in an increased vascularization of metastatic lesions.

The effects of surgery, with or without rhGM-CSF, on the angiogenic profile of patients treated for colorectal carcinoma.

Wound healing is a process with immunological and angiogenic aspects. rhGM-CSF is known to stimulate the immune system and angiogenesis via multiple pathways. In this study we investigated the combined effects of surgery, with or without rhGM-CSF, on angiogenic parameters in patients with a colorectal carcinoma. In this phase II randomized, placebo-controlled trial, 16 patients were assigned to perioperative rhGM-CSF (2.8 microg/kg body weight) treatment or saline. Patients received subcutaneous injections from three days before surgery until four days after. IL-6, VEGF, endostatin and angiostatin levels were measured perioperatively. rhGM-CSF enhanced the production of IL-6 and VEGF, but had no effect on the antiangiogenic agents endostatin and angiostatin. Surgery induced a transient decrease of endostatin. Two types of angiostatin (kringle 1-3 and kringle 1-4) became visible postoperatively. We conclude that this study demonstrated the immediate initiation of angiogenesis postoperatively, reflected by the increase of VEGF and a transient decrease of endostatin, followed by the appearance of two angiostatin bands, which confirms physiological wound healing in these cancer patients.

Anti-tumor activity of a combination of plasminogen activator and captopril in a human melanoma xenograft model.

Angiostatin, a proteolytic fragment of plasminogen consisting of the first 3 or 4 kringle domains, reduces tumor growth by specifically inhibiting tumor angiogenesis. Angiostatin is generated in vitro in a 2-step process. First, plasminogen is converted to plasmin by plasminogen activators. Next, plasmin excises the angiostatin fragment from plasminogen, a process requiring molecules that are able to donate a free sulfhydryl group. In this study, we investigated whether stimulation of in vivo angiostatin generation by administration of plasminogen activator and a free sulfhydryl group donor (FSD) has anti-tumor activity. First, we determined the optimal conditions for in vitro angiostatin generation by incubating murine plasma with different concentrations of plasminogen activator and/or the FSD captopril. Angiostatin generation was monitored by western blot analysis. Our results were extrapolated to the in vivo situation by administering the optimal dose of tissue-type plasminogen activator (tPA, i.v. injection 3 times/week) and captopril (in drinking water) to mice and analyzing the presence of angiostatin in the circulation. Angiostatin was readily detectable in mice receiving both tPA and captopril, but not in mice receiving either one of the agents. Finally, the anti-tumor activity of the tPA/captopril treatment was tested in a human melanoma xenograft model. Administration of tPA alone had only a marginal effect on tumor growth. Captopril alone reduced tumor growth by about 60%, whereas treatment with both captopril and tPA resulted in 83% inhibition of tumor growth.