As essential components of the eukaryotic cytoskeleton, microtubules fulfill a variety of functions that can be temporally and spatially controlled by tubulin posttranslational modifications. Tubulin ...glycylation has so far been mostly found on motile cilia and flagella, where it is involved in the stabilization of the axoneme. In contrast, barely anything is known about the role of glycylation in primary cilia because of limitations in detecting this modification in these organelles. We thus developed novel glycylation-specific antibodies with which we detected glycylation in many primary cilia. Glycylation accumulates in primary cilia in a length-dependent manner, and depletion or overexpression of glycylating enzymes modulates the length of primary cilia in cultured cells. This strongly suggests that glycylation is essential for the homeostasis of primary cilia, which has important implications for human disorders related to primary cilia dysfunctions, such as ciliopathies and certain types of cancer.
Changes in the oral microbiome, particularly Fusobacterium nucleatum, are associated with oral squamous cell carcinoma (OSCC). F. nucleatum has been reported to modulate local immunity in cancers. We ...aimed to assess the association between intratumoral F. nucleatum and clinico-pathological features, relapse, and overall survival (OS) in two independent cohorts of patients with OSCC, and to explore the interplay with immune-related genes. We retrospectively analyzed tissue samples from a first cohort of 122 patients with head and neck squamous cell carcinoma, including 61 OSCC (cohort #1), and a second cohort of 90 additional OSCC (cohort #2). We then performed a sensitivity analysis on the merged cohort of OSCC patients (N = 151). F. nucleatum 16S rRNA gene sequences were quantified using real-time quantitative PCR. The presence of gram-negative bacteria and macrophages was confirmed by LPS and CD163 immunostainings, respectively. F. nucleatum positivity was associated with older age, less alcohol and combined alcohol plus tobacco consumption, and less frequent lymph node invasion. There was a trend for a lower recurrence rate in F. nucleatum-positive cases, with less metastatic relapses compared to F. nucleatum-negative tumors, and significantly longer OS, relapse-free and metastasis-free survival. F. nucleatum status was independently associated with OS in multivariate analysis. Immune-related gene and immunohistochemistry analyses showed that gram-negative bacteria load inversely correlated with M2 macrophages. F. nucleatum-associated OSCC has a specific immune microenvironment, is more frequent in older, non-drinking patients, and associated with a favorable prognosis.
The actin cytoskeleton generates and senses forces. Here we report that branched actin networks from the cell cortex depend on ARPC1B-containing Arp2/3 complexes and that they are specifically ...monitored by type I coronins to control cell cycle progression in mammary epithelial cells. Cortical ARPC1B-dependent branched actin networks are regulated by the RAC1/WAVE/ARPIN pathway and drive lamellipodial protrusions. Accordingly, we uncover that the duration of the G1 phase scales with migration persistence in single migrating cells. Moreover, cortical branched actin more generally determines S-phase entry by integrating soluble stimuli such as growth factors and mechanotransduction signals, ensuing from substratum rigidity or stretching of epithelial monolayers. Many tumour cells lose this dependence for cortical branched actin. But the RAC1-transformed tumour cells stop cycling upon Arp2/3 inhibition. Among all genes encoding Arp2/3 subunits, ARPC1B overexpression in tumours is associated with the poorest metastasis-free survival in breast cancer patients. Arp2/3 specificity may thus provide diagnostic and therapeutic opportunities in cancer.
Resistance to endocrine treatments and CDK4/6 inhibitors is considered a near-inevitability in most patients with estrogen receptor positive breast cancers (ER + BC). By genomic and metabolomics ...analyses of patients' tumours, metastasis-derived patient-derived xenografts (PDX) and isogenic cell lines we demonstrate that a fraction of metastatic ER + BC is highly reliant on oxidative phosphorylation (OXPHOS). Treatment by the OXPHOS inhibitor IACS-010759 strongly inhibits tumour growth in multiple endocrine and palbociclib resistant PDX. Mutations in the PIK3CA/AKT1 genes are significantly associated with response to IACS-010759. At the metabolic level, in vivo response to IACS-010759 is associated with decreased levels of metabolites of the glutathione, glycogen and pentose phosphate pathways in treated tumours. In vitro, endocrine and palbociclib resistant cells show increased OXPHOS dependency and increased ROS levels upon IACS-010759 treatment. Finally, in ER + BC patients, high expression of OXPHOS associated genes predict poor prognosis. In conclusion, these results identify OXPHOS as a promising target for treatment resistant ER + BC patients.
Objective. The restoration of vision in blind patients suffering from degenerative retinal diseases like retinitis pigmentosa may be obtained by local electrical stimulation with retinal implants. In ...this study, a very large electrode array for retinal stimulation (VLARS) was introduced and tested regarding its safety in implantation and biocompatibility. Further, the array's stimulation capabilities were tested in an acute setting. Approach. The polyimide-based implants have a diameter of 12 mm, cover approximately 110 mm2 of the retinal surface and carrying 250 iridium oxide coated gold electrodes. The implantation surgery was established in cadaveric porcine eyes. To analyze biocompatibility, ten rabbits were implanted with the VLARS device, and observed for 12 weeks using slit lamp examination, fundus photography, optical coherence tomography (OCT) as well as ultrasound imaging. After enucleation, histological examinations were performed. In acute stimulation experiments, electrodes recorded cortical field potentials upon retinal stimulation in the visual cortex in rabbits. Main results. Implantation studies in rabbits showed that the implantation surgery is safe but difficult. Retinal detachment induced by retinal tears was observed in five animals in varying severity. In five cases, corneal edema reduced the quality of the follow-up examinations. Findings in OCT-imaging and funduscopy suggested that peripheral fixation was insufficient in various animals. Results of the acute stimulation demonstrated the array's ability to elicit cortical responses. Significance. Overall, it was possible to implant very large epiretinal arrays. On retinal stimulation with the VLARS responses in the visual cortex were recorded. The VLARS device offers the opportunity to restore a much larger field of visual perception when compared to current available retinal implants.
Abstract Objectives Immunotherapy for bladder cancer seems to have promising results. Here, we evaluated the association between messenger RNA (mRNA) and protein levels and possible prognostic value ...of the programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4) immune checkpoint pathways during bladder carcinogenesis. Methods and materials Tumor samples were obtained from 155 patients (84 with muscle-invasive bladder cancer MIBC, and 71 non–muscle-invasive bladder cancer NMIBC) and normal bladder tissue from 15 patients. We evaluated the mRNA expression of 3 genes in the PD-1 pathway ( PD-1 , PD-L1 , and PD-L2 ) and 4 in the CTLA4 pathway ( CTLA4 , CD28 , CD80 , and CD86 ) in normal and tumoral human bladder samples by quantitative real-time reverse transcription polymerase chain reaction, with immunohistochemistry used to evaluate the protein expression of PD-1 and PD-L1 in tumor and immune cells. Results of molecular analyses were compared with survival analyses. Results As compared with normal bladder tissue, MIBC tissue showed PD-1 , PD-L1 , CTLA4 , and CD80 overexpression (59.5%, 60.7%, 84.5%, and 92.9%, respectively), whereas overexpression was lower in NMIBC tissue (22.5%, 4.2%, 35.2%, and 46.5%, respectively). The results of reverse transcription polymerase chain reaction analysis were confirmed by immunohistochemistry, with a high correlation between mRNA and protein expression. On multivariate analyses, overexpression of the studied genes was not associated with prognosis in relapse or progression of NMIBC or in recurrence-free and overall survival of MIBC. Conclusions The CTLA4 pathway appears to be deregulated along with the PD-1/PD-L1 pathway in bladder carcinogenesis, with good correlation between mRNA and protein expression endorsing the useful role of immune checkpoints, especially for a large subgroup of MIBC.
Gene fusions provide access to new therapeutic opportunities for patients treated for a colorectal cancer (CRC). However, they do not excess 1% of patients. A better identification of patients in ...whom gene fusions are highly prevalent is a major issue in a therapeutic and medico-economics perspective. This study assesses the rates of gene fusions in CRC patients with MSI/RAS-BRAFWT in our routine practice detected with a commercially available NGS-based fusion panel. Among the 130 MSI CRC tumors, 43 (33%) were KRAS-NRAS-BRAFWT. A gene fusion was detected in 7 (25.9%) of the 27 MSI/RAS-BRAFWT samples, which had RNA suitable for analysis after quality control. These fusions involved mainly NTRK1/3 (n = 5), as well as ALK (n = 1) and BRAF (n = 1). In the present study, we confirm that patients with MSI/RAS-BRAFWT CRCs represent a subpopulation in which targetable gene fusions are overrepresented. Our results support the use of a two-step algorithm for molecular screening, in which metastatic CRC patients would have routine MSI and RAS/BRAF testing, and then only those with MSI/RAS-BRAFWT would be screened with dedicated NGS RNA panel for gene fusions.
•Gene fusions do not excess 1% of patients with colorectal cancer (CRC).•Gene fusions are overrepresented in patients with MSI/RAS-BRAFWT CRC.•Most of gene fusions provide access to new therapeutic opportunities.•Our results support the use of a two-step algorithm for molecular screening.
Everolimus is widely used in patients with advanced ER‐positive, HER2‐negative breast cancer. We looked at alterations in the PIK3CA/AKT/mTOR pathway in a multicenter cohort as potential biomarkers ...of efficacy. Patients with advanced ER‐positive, HER2‐negative breast cancer treated with everolimus and endocrine therapy between 2012 and 2014 in two cancer centers were included. Targeted sequencing examined mutations in PIK3CA, ESR1, and AKT1 genes. An immunochemical analysis was conducted to evaluate expression of PTEN, INPP4B, STK11, p4EBP1, and pS6. We analyzed 71 patients (44 primary tumors; 27 metastatic tissues). Median age was 63 years 58–69. All patients had heavily pretreated advanced disease. A mutation in the PIK3CA pathway was observed in 32 samples (PIK3CA exons 10 and 21 and AKT1 exon 4 in 15.5%, 24.0%, and 5.6% of samples), and in ESR1 in 5 samples (7.0%), respectively. Most samples showed cytoplasmic expression of the PIK3CA pathway proteins. Progression‐free survival was longer in patients with a pS6 or p4EBP1 histoscore ≥ median value (6.6 versus 3.7 months, p = 0.037), and in patients with a PTEN histoscore ≤ median value (7.1 versus 5.3 months, p = 0.02). Overall survival was longer in patients with pS6 ≥ 3rd quartile (27.6 versus 19.3 months, p = 0.038) and in patients with any mutation in the PIK3CA/AKT/mTOR pathway (27.6 versus 19.3 months, p = 0.011). The prognosis of patients treated with everolimus for advanced ER‐positive, HER2‐negative breast cancer appears primarily driven by molecular features associated with the activation of the PIK3CA/AKT/mTOR pathway.
A promising avenue for cancer treatment is exacerbating the deregulation of the DNA repair machinery that would normally protect the genome. To address the applicability of poly(ADP-ribose) ...polymerase (PARP) inhibitors (PARPi) combined with radiotherapy for the treatment of hepatocellular carcinoma (HCC) two approaches were used: firstly, the in vitro sensitivity to the PARPi Veliparib and Talazoparib +/- radiation exposure was determined in liver cell lines and the impact of the HBV X protein (HBx) that deregulates cellular DNA damage repair via SMC5/6 degradation was investigated. Secondly, PARP expression profiles and DNA damage levels using the surrogate marker gammaH2AX were assessed in a panel of control liver vs HCC tissues.
Cell cytotoxicity was measured by clonogenic survival or relative cell growth and the DNA damage response using immunological-based techniques in Hep3B, PLC/PRF/5, HepG2- and HepaRG-derived models. Transcriptome changes due to HBx expression vs SMC6 loss were assessed by RNA sequencing in HepaRG-derived models. PARP and PARG transcripts (qPCR) and PARP1, H2AX and gammaH2AX protein levels (RPPA) were compared in control liver vs HBV-, HCV-, alcohol- and non-alcoholic steatohepatitis-associated HCC (tumor/peritumor) tissues.
PARPi cytotoxicity was significantly enhanced when combined with X-rays (2Gy) with Talazoparib having a greater impact than Veliparib in most in vitro models. HBx expression significantly lowered survival, probably driven by SMC5/6 loss based on the transcriptome analysis and higher DNA damage levels. PARP1 and PARP2 transcript levels were significantly higher in tumor than peritumor and control tissues. The HBV/HCV/alcohol-associated tumor tissues studied had reduced H2AX but higher gammaH2AX protein levels compared to peritumor and control tissues providing evidence of increased DNA damage during liver disease progression.
These proof-of-concept experiments support PARPi alone or combined with radiotherapy for HCC treatment, particularly for HBV-associated tumors, that warrant further investigation.
Chordomas are rare neoplasms characterized by a high recurrence rate and a poor long-term prognosis. Considering their chemo-/radio-resistance, alternative treatment strategies are strongly required, ...but their development is limited by the paucity of relevant preclinical models. Mutations affecting genes of the SWI/SNF complexes are frequently found in chordomas, suggesting a potential therapeutic effect of epigenetic regulators in this pathology. Twelve PDX models were established and characterized on histological and biomolecular features. Patients whose tumors were able to grow into mice had a statistically significant lower progression-free survival than those whose tumors did not grow after in vivo transplantation (
= 0.007). All PDXs maintained the same histopathological features as patients' tumors. Homozygous deletions of
(58.3%) and
(25%) variants were the most common genomic alterations found. In the tazemetostat treated PDX model harboring a
variant, an overall survival of 100% was observed. Our panel of chordoma PDXs represents a useful preclinical tool for both pharmacologic and biological assessments. The first demonstration of a high antitumor activity of tazemetostat in a PDX model harboring a
variant supports further evaluation for EZH2-inhibitors in this subgroup of chordomas.
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