The t(4;8)(p16;p23) translocation, in either the balanced form or the unbalanced form, has been reported several times. Taking into consideration the fact that this translocation may be undetected in routine cytogenetics, we find that it may be the most frequent translocation after t(11q;22q), which is the most common reciprocal translocation in humans. Case subjects with der(4) have the Wolf-Hirschhorn syndrome, whereas case subjects with der(8) show a milder spectrum of dysmorphic features. Two pairs of the many olfactory receptor (OR)-gene clusters are located close to each other, on both 4p16 and 8p23. Previously, we demonstrated that an inversion polymorphism of the OR region at 8p23 plays a crucial role in the generation of chromosomal imbalances through unusual meiotic exchanges. These findings prompted us to investigate whether OR-related inversion polymorphisms at 4p16 and 8p23 might also be involved in the origin of the t(4;8)(p16;p23) translocation. In seven case subjects (five of whom both represented de novo cases and were of maternal origin), including individuals with unbalanced and balanced translocations, we demonstrated that the breakpoints fell within the 4p and 8p OR-gene clusters. FISH experiments with appropriate bacterial-artificial-chromosome probes detected heterozygous submicroscopic inversions of both 4p and 8p regions in all the five mothers of the de novo case subjects. Heterozygous inversions on 4p16 and 8p23 were detected in 12.5% and 26% of control subjects, respectively, whereas 2.5% of them were scored as doubly heterozygous. These novel data emphasize the importance of segmental duplications and large-scale genomic polymorphisms in the evolution and pathology of the human genome.
SummaryDysfunctions in mitochondrial dynamics and metabolism are common pathological processes associated with Parkinson’s disease (PD). It was recently shown that an inherited form of PD and dementia is caused by mutations in the OPA1 gene, which encodes for a key player in mitochondrial fusion and structure. iPSC-derived neural cells from these patients exhibited severe mitochondrial fragmentation, respiration impairment, ATP deficits, and heightened oxidative stress. Reconstitution of normal levels of OPA1 in PD-derived neural cells normalized mitochondria morphology and function. OPA1-mutated neuronal cultures showed reduced survival in vitro. Intriguingly, selective inhibition of necroptosis effectively rescued this survival deficit. Additionally, dampening necroptosis in MPTP-treated mice protected from DA neuronal cell loss. This human iPSC-based model captures both early pathological events in OPA1 mutant neural cells and the beneficial effects of blocking necroptosis, highlighting this cell death process as a potential therapeutic target for PD.
Previous studies have suggested a "catalytic role" in neoplastic angiogenesis and cancer progression for bone marrow-derived endothelial progenitor cells (EPC). However, preclinical and clinical studies have shown that the quantitative role of marrow-derived EPCs in cancer vascularization is extremely variable. We have found that human and murine white adipose tissue (WAT) is a very rich reservoir of CD45-CD34þ EPCs with endothelial differentiation potential, containing a mean of 263 times more CD45-CD34 þ cells/mL than bone marrow.Compared with marrow-derived CD34 þ cells mobilized in blood by granulocyte colony-stimulating factor, purified WAT-CD34 þ cells expressed similar levels of stemness-related genes, significantly increased levels of angiogenesis-related genes, and increased levels of FAP-a, a crucial suppressor of antitumor immunity.
The human white adipose tissue (WAT) contains progenitors with cooperative roles in breast cancer (BC) angiogenesis, local and metastatic progression. The biguanide Metformin (Met), commonly used for Type 2 diabetes, might have activity against BC and was found to inhibit angiogenesis in vivo. We studied Met and another biguanide, phenformin (Phe), in vitro and in vivo in BC models. In vitro, biguanides activated AMPK, inhibited Complex 1 of the respiratory chain and induced apoptosis of BC and WAT endothelial cells. In coculture, biguanides inhibited the production of several angiogenic proteins. In vivo, biguanides inhibited local and metastatic growth of triple negative and HER21 BC in immune-competent and immune-deficient mice orthotopically injected with BC. Biguanides inhibited local and metastatic BC growth in a genetically engineered murine model model of HER21 BC. In vivo, biguanides increased pimonidazole binding (but not HIF-1 expression) of WAT progenitors, reduced tumor microvessel density and altered the vascular pericyte/endothelial cell ratio, so that cancer vessels displayed a dysplastic phenotype. Phe was significantly more active than Met both in vitro and in vivo. Considering their safety profile, biguanides deserve to be further investigated for BC prevention in high-risk subjects, in combination with chemo and/or targeted therapy and/or as post-therapy consolidation or maintenance therapy for the prevention of BC recurrence.There is increasing preclinical evidence that the biguanide Metformin (Met), commonly used for the therapy of Type 2 diabetes, might have activity against several types of neoplastic diseases 1-25 including breast cancer (BC). Another biguanide, phenformin (Phe), which was dismissed from the arsenal of antidiabetes drug because of some side effects, has shown preclinical activity in a model of BC. 26 We and others have recently shown that two populations of human white adipose tissue (WAT) CD45-CD341 progenitors have cooperative roles in BC angiogenesis, local and metastatic progression. [27][28][29][30][31][32][33][34][35] In orthotopic murine models we found that (i) purified human WAT CD341CD131 mesenchymal adipose stromal cell progenitors (ASCs) were not able to migrate but promoted local tumor growth in the mammary fat pad and (ii) purified human WAT CD341CD311 endothelial progenitor cells (EPCs) were able to migrate toward lymph nodes and blood and promoted BC cell EMT, migration, invasion and metastatic growth. 34In another recent study we have found that Met inhibited the formation of capillary-like networks by human umbilical vein endothelial cells (HUVEC), and decreased microvessel density (MVD) in tumor-free mice. 36 Here we report that Met and Phe (with even more efficacy) targeted in vitro and in vivo both BC cells and WAT EPCs, resulting in profound effects on BC angiogenesis, local and metastatic growth that are likely due to additive effects on both tumor and microenvironment cells. These effects were observed both in triple negative and in HER21 models o...
Our results excluded most of the possible explanations for the POF phenotype and suggested that POF should be ascribed to a position effect of the breakpoints on flanking genes. We also showed that while the X breakpoint may affect X-linked genes in the distal part of Xq, from Xq23 to Xq28, interruption of the critical region in Xq21 could be explained by a position effect of the Xq critical region on genes flanking the autosomal breakpoints.
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