Endovascular Recanalization of Tandem Internal Carotid Occlusions Using the Balloon-assisted Tracking Technique.

PURPOSE: Tandem occlusive lesions are responsible for up to 20% of acute ischemic stroke cases and are associated with poor prognosis if complete recanalization cannot be achieved. Endovascular recanalization might be challenging due to difficulties in the safe passage of the occluded plaque at the origin of the internal carotid artery (ICA). The balloon-assisted tracking technique (BAT), where a partially deflated balloon is exposed out of the catheter tip to facilitate its passage through stenosed or spastic arterial segments was introduced by interventional cardiologists and the applicability of the technique has been recently proposed in the field of neurointervention as well. Here we describe our experience using the BAT technique in the endovascular recanalization of tandem occlusive lesions. METHODS: Procedures were performed from June 2013 to December 2020 in a single center. Baseline clinical and imaging data, procedural and follow-up details and clinical outcomes were retrospectively collected. RESULTS: In this study 107 patients, median age 66 years, median admission NIHSS 14 and median ASPECTS 8 were included. Successful recanalization of the ICA using the BAT technique was achieved in 100 (93%) and successful intracranial revascularization in 88 (82%) patients. There were no complications attributable to the BAT technique. Intraprocedural complications occurred in 9 (8%) patients. Emergent stenting was performed in 40 (37%) at the end of the procedure. Postprocedural adverse events (intracerebral hemorrhage [ICH], malignant infarction) occurred in 6 (5%) patients. Good clinical outcome at 3 months (modified Rankin scale [mRS] 0-2) was 54 (50%) and mortality 26 (24%). Delayed stent placement during follow-up occurred in 21 cases. CONCLUSION: Application of BAT technique in tandem occlusions appears feasible, safe, and efficient. Further evaluation of this technique is awaited.

ITIH5 shows tumor suppressive properties in cervical cancer cells grown as multicellular tumor spheroids.

Cervical cancer (CC) arises from premalignant cervical intraepithelial neoplasia (CIN) induced by a persistent infection with human papillomaviruses. The multi-stepwise disease progression is driven by genetic and epigenetic alterations. Our previous studies demonstrated a clear downregulation of inter-α-trypsin-inhibitor-heavy chain 5 (ITIH5) at mRNA and protein levels in CC compared to CIN2/3 and normal cervical tissue. Initial in vitro functional analyses revealed a suppressive effect of ITIH5 on relevant mechanisms for cancer progression in conventional two dimensional (2D) cell culture model systems. Based on these studies, we aimed to investigate the functional relevance of ITIH5 in multicellular tumor spheroid (MCTS) models, which resemble in vivo tumors more closely. We successfully established CC cell line-derived MCTS using the hanging-drop technique. ITIH5 was ectopically overexpressed in HeLa and SiHa cells and its functional relevance was investigated under three dimensional (3D) culture conditions. We found that ITIH5 re-expression significantly suppressed tumor spheroid growth and spheroid invasiveness of both HeLa and SiHa spheroids. Immunohistochemical (IHC) analyses revealed a significant reduction in Ki-67 cell proliferation index and CAIX-positive areas indicative for hypoxia and acidification. Furthermore, we observed an increase in cPARP-positive cells suggesting a higher rate of apoptosis upon ITIH5 overexpression. An effect of ITIH5 expression on the susceptibility of cervical MCTS towards cytostatic drug treatment was not observed. Collectively, these data uncover pronounced anti-proliferative effects of ITIH5 under 3D cell culture conditions and provide further functional evidence that the downregulation of ITIH5 expression during cervical carcinogenesis could support cancer development.

Breast cancer, placenta and pregnancy.

BACKGROUND: Breast cancer is one of the most frequently diagnosed malignancies during pregnancy. Tumours often present characteristics of high malignancy and are hormone receptor negative/HER2 positive or triple negative. In general, pregnancy, including the postpartum period, is associated with a transiently increased risk of developing breast cancer but followed by a long-lasting protective period. Placental metastases are very rare and, thus far, breast cancer metastases in the foetal compartment have not been described. To discuss these apparently contradictory observations, this narrative review resumes immunological and hormonal alterations during pregnancy potentially affecting breast cancer risk as well as tumour growth and behaviour. OBSERVATIONS: Upregulation of breast cancer-associated genes involved in immunological and reproductive processes has been observed in parous women and is potentially responsible for a transiently increased risk in pregnancy. In contrast, maternal immunisation and immunoglobulin production against antigens expressed on trophoblast cells, such as specific glycosylation patterns of mucin-1 or RCAS1-associated truncated glycans, seem to prevent breast cancer development in later years. Animal and human studies indicate that T cells are involved in these processes. Several placenta-derived factors, especially kisspeptin, have direct anti-tumour effects. The pregnancy-related increase of estrogen, progesterone, and other hormones influence growth and characteristics of breast cancer while the role of further placenta-secreted factors is still controversially discussed. CONCLUSION: Several factors and cells are involved in altered breast cancer risk during and after pregnancy and have potential for developing novel treatment strategies in future.

Human serum alters cell culture behavior and improves spheroid formation in comparison to fetal bovine serum.

BACKGROUND: The use of fetal bovine serum (FBS) as growth supplement for human cell and tissue culture is widely spread in basic research as well as in clinical approaches, although several limitations must be considered, such as unstable composition and availability, biosafety and ethical aspects. Regarding interspecies differences, xenogeneic growth factors may evoke incompatibilities and non-desired interactions with human cells resulting in imprecise outcome of human-relevant data. METHODS: In this study the functionality of human serum (HS) has been investigated in comparison to FBS by assessing proliferation, migration and invasion of the human cervical cancer cell lines SiHa and HeLa. The effects of both sera on spheroid formation were analyzed microscopically. RESULTS: Both, FBS and HS, stimulate cell proliferation and migration similarly, whereas HS significantly enhanced cell invasion. The spheroid formation assay revealed remarkable differences between both sera, especially for SiHa cells. While in FBS supplemented medium cells only formed loose aggregates, HS induced regularly shaped spheroids under all tested conditions. CONCLUSION: We were able to demonstrate that HS and FBS differently influence behavior of cells in culture which may have an impact on experimental results, especially in 3D cultures.

Uterine natural killer cells in patients with idiopathic recurrent miscarriage.

PROBLEM: Uterine natural killer (uNK) cells are major players during implantation and early pregnancy. The aim of our study was to analyze uNK cell concentration in the endometrium of idiopathic recurrent miscarriage (iRM) patients and fertile controls. METHOD OF STUDY: Out of n=130 couples with ≥3 consecutive, clinical RM screened according to a standardized diagnostic protocol, n=58 patients with iRM were identified. Endometrial biopsies were investigated in patients and n=17 fertile women (controls) via immunohistochemistry. RESULTS: Compared to controls, the concentration of uNK cells was significantly higher in iRM patients (257±212 vs. 148±73 uNK cells/mm², P=.04). IRM patients showed a higher prevalence of >300 uNK cells/mm² than controls (34.5% vs. 5.9%, P=.02). In 88% of controls and 62% of iRM patients, uNK cells were detected within the range of 40-300/mm². CONCLUSION: Idiopathic recurrent miscarriage patients showed higher uNK cell levels than controls supporting the possible impact of uNK cells in the pathophysiology of miscarriage. Our cutoff levels might help to select RM patients which may benefit from immunomodulatory treatment.

Generation of Multicellular Breast Cancer Tumor Spheroids: Comparison of Different Protocols.

Multicellular tumor spheroids are widely used models in tumor research. Because of their three dimensional organization they can simulate avascular tumor areas comprising proliferative and necrotic cells. Nonetheless, protocols for spheroid generation are still inconsistent. Therefore, in this study the breast cancer cell lines MCF-7, MDA-MB-231 and SK-BR-3 have been used to compare different spheroid generation models including hanging drop, liquid overlay and suspension culture techniques, each under several conditions. Experimental approaches differed in cell numbers (400-10,000), media and additives (25 % methocel, 25 % methocel plus 1 % Matrigel, 3.5 % Matrigel). In total, 42 different experimental setups have been tested. Generation of spheroids was evaluated by light microscopy and the structural composition was assessed immunohistochemically by means of Ki-67, cleaved poly (ADP-ribose) polymerase (cPARP) and mucin-1 (MUC-1) expression. Although the tested cell lines diverged widely in their capacity of forming spheroids we recommend hanging drops supplemented with 25 % methocel as the most reliable and efficient method with regard to success of generation of uniform spheroids, costs, experimental complexity and time expenditure in the different cell lines. MCF-7 cells formed spheroids under almost all analyzed conditions, and MDA-MB-231 cells under only one protocol (liquid overlay technique, 3.5 % Matrigel), while SK-BR-3 did not under neither condition. Therefore, we outline specific methods and recommend the use of adapted and standardized spheroid generation protocols for each cell line.