Hypoxia-Induced Caveolin-1 Expression Promotes Migration and Invasion of Tumor Cells

BACKGROUND

Exacerbated proliferation of cancer cells in nascent tumors leads to the genesis of a hypoxic microenvironment, which is associated with poor patient prognosis, because these stress conditions enhance migratory, invasive and metastatic capacities of tumor cells. These changes are associated with the induction of the hypoxia-inducible factors (HIFs, mainly HIF1α) and increased expression of target genes, including Caveolin-1 (CAV1). Results from our group have shown that CAV1 expression in metastatic cancer cells promotes cell migration/invasion in vitro and metastasis in vivo in a manner dependent on tyrosine-14 phosphorylation by src family kinases. Here, we evaluated whether hypoxia-induced expression of CAV1 was required for hypoxia-dependent migration and invasion in cancer cells.

METHODS

B16-F10 murine melanoma and HT29(US) colon adenocarcinoma cells were exposed to hypoxia (1% O2). CAV1 expression was evaluated by western blotting. Endogenous CAV1 and HIF1α were knocked-down using different shRNA constructs. Cell migration and invasion were evaluated in Boyden Chamber and Matrigel assays, respectively.

RESULTS

We observed that hypoxia increased CAV1 protein levels in a HIF1 α- dependent manner, in B16-F10 and HT29(US) cells. Importantly, hypoxia-dependent migration of both tumor cell lines was blocked upon CAV1 knock-down. Likewise, pharmacological inhibition of HIF prevented hypoxia-induced migration and invasion in B16-F10 cells. Finally, hypoxia-induced migration was also blocked by the src-family kinase inhibitor 4-amino-5-(4-chloro-phenyl)-7-(t-butyl) pyrazolo3,4-dpyrimidine (PP2), an inhibitor of CAV1 phosphorylation.

CONCLUSION

Hypoxia induced migration and invasion of metastatic cancer cells require HIF1α-dependent induction of CAV1 expression and src family kinase activation.

Origin and composition of cell-free DNA in spent medium from human embryo culture during preimplantation development

STUDY QUESTION

What is the origin and composition of cell-free DNA in human embryo spent culture media?

SUMMARY ANSWER

Cell-free DNA from human embryo spent culture media represents a mix of maternal and embryonic DNA, and the mixture can be more complex for mosaic embryos.

WHAT IS KNOWN ALREADY

In 2016, ~300 000 human embryos were chromosomally and/or genetically analyzed using preimplantation genetic testing for aneuploidies (PGT-A) or monogenic disorders (PGT-M) before transfer into the uterus. While progress in genetic techniques has enabled analysis of the full karyotype in a single cell with high sensitivity and specificity, these approaches still require an embryo biopsy. Thus, non-invasive techniques are sought as an alternative.

STUDY DESIGN, SIZE, DURATION

This study was based on a total of 113 human embryos undergoing trophectoderm biopsy as part of PGT-A analysis. For each embryo, the spent culture media used between Day 3 and Day 5 of development were collected for cell-free DNA analysis. In addition to the 113 spent culture media samples, 28 media drops without embryo contact were cultured in parallel under the same conditions to use as controls. In total, 141 media samples were collected and divided into two groups: one for direct DNA quantification (53 spent culture media and 17 controls), the other for whole-genome amplification (60 spent culture media and 11 controls) and subsequent quantification. Some samples with amplified DNA (N = 56) were used for aneuploidy testing by next-generation sequencing; of those, 35 samples underwent single-nucleotide polymorphism (SNP) sequencing to detect maternal contamination. Finally, from the 35 spent culture media analyzed by SNP sequencing, 12 whole blastocysts were analyzed by fluorescence in situ hybridization (FISH) to determine the level of mosaicism in each embryo, as a possible origin for discordance between sample types.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Trophectoderm biopsies and culture media samples (20 μl) underwent whole-genome amplification, then libraries were generated and sequenced for an aneuploidy study. For SNP sequencing, triads including trophectoderm DNA, cell-free DNA, and follicular fluid DNA were analyzed. In total, 124 SNPs were included with 90 SNPs distributed among all autosomes and 34 SNPs located on chromosome Y. Finally, 12 whole blastocysts were fixed and individual cells were analyzed by FISH using telomeric/centromeric probes for the affected chromosomes.

MAIN RESULTS AND THE ROLE OF CHANCE

We found a higher quantity of cell-free DNA in spent culture media co-cultured with embryos versus control media samples (P ≤ 0.001). The presence of cell-free DNA in the spent culture media enabled a chromosomal diagnosis, although results differed from those of trophectoderm biopsy analysis in most cases (67%). Discordant results were mainly attributable to a high percentage of maternal DNA in the spent culture media, with a median percentage of embryonic DNA estimated at 8%. Finally, from the discordant cases, 91.7% of whole blastocysts analyzed by FISH were mosaic and 75% of the analyzed chromosomes were concordant with the trophectoderm DNA diagnosis instead of the cell-free DNA result.

LIMITATIONS, REASONS FOR CAUTION

This study was limited by the sample size and the number of cells analyzed by FISH.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to combine chromosomal analysis of cell-free DNA, SNP sequencing to identify maternal contamination, and whole-blastocyst analysis for detecting mosaicism. Our results provide a better understanding of the origin of cell-free DNA in spent culture media, offering an important step toward developing future non-invasive karyotyping that must rely on the specific identification of DNA released from human embryos.

STUDY FUNDING/ COMPETING INTEREST

This work was funded by Igenomix S.L. There are no competing interests.

Autism Treatment Evaluation Checklist (ATEC) Norms: A "Growth Chart" for ATEC Score Changes as a Function of Age

Most early-intervention Autism Spectrum Disorder (ASD) clinical trials are limited by the availability of psychometric technicians who assess each child's abilities before and after therapeutic intervention. If parents could administer regular psychometric evaluations of their children, then the cost of clinical trials will be reduced, enabling longer clinical trials with the larger number of participants. The Autism Treatment Evaluation Checklist (ATEC) was designed nearly two decades ago to provide such a tool, but the norms on the longitudinal changes in ATEC in the "treatment as usual" population were lacking. Here we report the norms of the observational cohort who voluntarily completed ATEC evaluations over the period of four years from 2013 to 2017.

[Neuroplasticity: synaptogenesis during normal development and its implication in intellectual disability]

Neuroplasticity is the biological capacity of the nervous system to modify its structure and functioning to adapt to both physiological and pathological variations in the environment. Its main physiological consequences are learning and memory, and its pathological outcome is neurological rehabilitation. The continuous change and initial fragility of the developing brain make the embryonic and foetal periods especially plastic (what is known as developmental neuroplasticity). The progressive reduction in plasticity, however, is never complete and the capacity to modify the brain circuits in response to new learning (adaptive neuroplasticity) or brain injuries (reactive neuroplasticity) remains throughout the individual's entire lifespan. The main neurobiological mechanism underlying neuroplasticity is the formation of synaptic contacts between neurons. Neurodevelopmental disorders are associated to functional anomalies of the brain, often derived from the lack of adaptive or reactive capacity of the brain to modify circuits that are malformed or damaged by genetic or environmental anomalies. They are traditionally associated with the appearance of intellectual disability and mental illnesses. This review deals with the development of the neuroplasticity of the brain and its neurobiological mechanisms. Some of the cellular and molecular processes involved in its normal development are also examined, together with the possible consequences deriving from alterations affecting them.

Synthesis of 4-aryl-1,2,3-triazolyl appended natural coumarin-related compounds with antiproliferative and radical scavenging activities and intracellular ROS production modification

Diverse natural coumarin-based compounds linked to aryl via a 1,2,3-triazole spacer with antiproliferative activity against K562 cells, radical scavenging activity and a decrease of ROS production were provided.

[Brain development and plasticity]

Neurodevelopmental disorders are associated to functional anomalies of the brain that become manifest early on in life. Traditionally, they have been related almost exclusively to the appearance of intellectual disability and delayed psychomotor development. The causes of these disorders have been partially described, and include anomalies due to genetic causes (Down syndrome, fragile X syndrome, etc.), exposure to toxic factors during pregnancy (foetal alcohol syndrome), infections (cytomegalovirus, toxoplasmosis, etc.) or other alterations, including a status of great immaturity at birth (very preterm). Epidemiological data based on a better knowledge of the diseases affecting the central nervous system suggest that some mental disorders, which appear in adolescence or early adulthood, also have their origin in anomalies in brain development. This review aims to offer an overview of brain development. Some of the cellular and molecular processes that may account for the similarities and differences in the phenotypes that generate alterations affecting normal development are also analysed. The study is conducted with a view to clearly identifying processes that are susceptible to modification by means of therapeutic intervention consisting in an early care programme.

[Endobronchial ultrasound in the diagnosis of malignant pleural mesothelioma]

The diagnosis of malignant pleural mesothelioma relies mostly on the pathological examination of pleural samples, validated by a panel of experts and generally obtained during medical or surgical thoracoscopy performed for the management of an exudative pleural effusion. In the absence of pleural effusion (dry-type mesothelioma), the diagnostic approach depends on the features of the lesions (pleural thickness, nodules and/or masses) and their pleural location. Ultrasound and CT-guided needle aspiration represent recognized alternative diagnostic techniques in these situations. We present the case of a patient, presenting a dry-type mesothelioma, whose diagnosis was obtained by endobronchial ultrasound (EBUS)-guided needle aspiration of a pleural mediastinal mass and confirmed by a CT-guided needle aspiration of another pleural mass in close contact with the chest wall. The samples have been compared and show quantitative and qualitative similarities. EBUS represents a minimally invasive alternative diagnostic technique for dry-type mesothelioma, showing thickness of the mediastinal pleura in contact with a central airway or when thoracoscopy, which remains the "gold standard" diagnostic approach, is not feasible.

[Bilateral diaphragmatic paralysis due to Parsonage-Turner syndrome]

We report the case of a 49-years-old patient who presented to the accident and emergency department with sudden onset dyspnea associated with acute shoulder pain. He was breathless at rest with supine hypoxemia. He had an amyotrophic left shoulder with localized paresis of the shoulder. Both hemi-diaphragms were elevated on chest X-rays. Pulmonary function tests showed a restrictive pattern and both phrenic nerve conduction velocities were decreased. At night, alveolar hypoventilation was evidenced by elevated mean capnography (PtcCO2: 57mmHg). Neuralgic amyotrophy, Parsonage-Turner syndrome was the final diagnosis. This syndrome is a brachial plexus neuritis with a predilection for the suprascapular and axillary nerves. Phrenic nerve involvement is rare but where present can be the most prominent clinical feature as in our case report.

HPV-negative carcinoma of the uterine cervix: a distinct type of cervical cancer with poor prognosis

OBJECTIVE

Using highly sensitive polymerase chain reaction (PCR) techniques, we reanalysed all cervical carcinomas (CCs) found to be human papillomavirus (HPV)-negative by Hybrid Capture 2 (HC2) to determine the prevalence of true HPV-negativity. We also evaluated the characteristics of the patients with tumours with confirmed HPV-negativity.

DESIGN

Observational study.

SETTING

Barcelona, Spain.

POPULATION

A cohort of 136 women with CC (32 adenocarcinomas, 104 squamous cell carcinomas) who had pre-treatment HC2 testing.

METHODS

All negative cases were reanalysed and genotyped for HPV using three PCR assays (SPF10, GP5+/6+ and E7-specific assay).

MAIN OUTCOME MEASURES

Percentage of confirmed HPV-negative and HPV-positive tumours. Clinicopathological features and disease-free survival (DFS) and overall survival (OS) of both groups.

RESULTS

Fourteen of 136 women (10.2%) were negative for HPV by HC2. After reanalysis by PCR-based techniques only 8/136 (5.8%) tumours were confirmed as HPV-negative, whereas in six cases different HPVs were identified [HPV-11, -16 (two tumours), -18, -45, and -68]. Confirmed HPV-negativity was more frequent in adenocarcinomas than in squamous cell carcinomas (5/32, 15.6% versus 3/104, 2.9%, respectively; P = 0.017). Patients with CCs with confirmed HPV-negativity had significantly worse DFS than women with HPV-positive tumours [51.9 months (95% CI 12.2-91.7 months) versus 109.9 months (95% CI 98.2-121.5 months); P = 0.010]. In the multivariate analysis HPV-negativity and International Federation of Gynecology and Obstetrics (FIGO) staging were associated with increased risk of progression and mortality.

CONCLUSIONS

An HC2-negative result is an uncommon finding in women with CC, but in almost half of these cases HPVs are identified by more sensitive techniques. CCs with confirmed HPV-negativity are more frequently adenocarcinomas, and seem to be associated with worse DFS.