Lauren diffuse-type gastric adenocarcinomas (DGAs) are generally genomically stable. We identified lysine (K)-specific methyltransferase 2C (
) as a frequently mutated gene and examined its role in ...DGA progression.
We performed whole exome sequencing on tumor samples of 27 patients with DGA who underwent gastrectomy. Lysine (K)-specific methyltransferase 2C (
) was analyzed in DGA cell lines and in patient tumors.
was the most frequently mutated gene (11 of 27 tumors 41%). KMT2C expression by immunohistochemistry in tumors from 135 patients with DGA undergoing gastrectomy inversely correlated with more advanced tumor stage (
= 0.023) and worse overall survival (
= 0.017). KMT2C shRNA knockdown in non-transformed HFE-145 gastric epithelial cells promoted epithelial-to-mesenchymal transition (EMT) as demonstrated by increased expression of EMT-related proteins N-cadherin and Slug. Migration and invasion in gastric epithelial cells following KMT2C knockdown increased by 47- to 88-fold. In the DGA cell lines MKN-45 and SNU-668, which have lost KMT2C expression, KMT2C re-expression decreased expression of EMT-related proteins, reduced cell migration by 52% to 60%, and reduced cell invasion by 50% to 74%. Flank xenografts derived from KMT2C-expressing DGA organoids, compared with wild-type organoids, grew more slowly and lost their infiltrative leading edge. EMT can lead to the acquisition of cancer stem cell (CSC) phenotypes. KMT2C re-expression in DGA cell lines reduced spheroid formation by 77% to 78% and reversed CSC resistance to chemotherapy via promotion of DNA damage and apoptosis.
is frequently mutated in certain populations with DGA. KMT2C loss in DGA promotes EMT and is associated with worse overall survival.
•GenScript cPass is a user-friendly commercial neutralising antibodies(nAb) assay.•The assay sensitivity was high when tested in DRC (88 %) and Belgium (94 %).•We recommend the test for surveillance ...purposes in sub-Saharan Africa.
High-throughput serological tests that can detect neutralizing antibodies against SARS-CoV-2 are desirable for serosurveillance and vaccine efficacy evaluation. Although the conventional neutralization test (cVNT) remains the gold standard to confirm the presence of neutralizing antibodies in sera, the test is too labour-intensive for massive screening programs and less reproducible as live virus and cell culture is involved. Here, we performed an independent evaluation of a commercially available surrogate virus neutralization test (sVNT, GenScript cPass™) that can be done without biosafety level 3 containment in less than 2 h. When using the cVNT and a Luminex multiplex immunoassay (MIA) as reference, the sVNT obtained a sensitivity of 94 % (CI 90–96 %) on a panel of 317 immune sera that were obtained from hospitalized and mild COVID-19 cases from Belgium and a sensitivity of 88 % (CI 81–93 %) on a panel of 184 healthcare workers from the Democratic Republic of Congo. We also found strong antibody titer correlations (rs>0.8) among the different techniques used. In conclusion, our evaluation suggests that the sVNT could be a powerful tool to monitor/detect neutralising antibodies in cohort and population studies. The technique could be especially useful for vaccine evaluation studies in sub-Saharan Africa where the basic infrastructure to perform cVNTs is lacking.
Few prospective studies have compared poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors to chemotherapy for the treatment of BRCA1-mutated or BRCA2-mutated ovarian carcinoma. We aimed ...to assess rucaparib versus platinum-based and non-platinum-based chemotherapy in this setting.
In this open-label, randomised, controlled, phase 3 study (ARIEL4), conducted in 64 hospitals and cancer centres across 12 countries (Brazil, Canada, Czech Republic, Hungary, Israel, Italy, Poland, Russia, Spain, Ukraine, the UK, and the USA), we recruited patients aged 18 years and older with BRCA1-mutated or BRCA2-mutated ovarian carcinoma, with an Eastern Cooperative Oncology Group performance status of 0 or 1, and who had received two or more previous chemotherapy regimens. Eligible patients were randomly assigned (2:1), using an interactive response technology and block randomisation (block size of six) and stratified by progression-free interval after the most recent platinum-containing therapy, to oral rucaparib (600 mg twice daily) or chemotherapy (administered per institutional guidelines). Patients assigned to the chemotherapy group with platinum-resistant or partially platinum-sensitive disease were given paclitaxel (starting dose 60–80 mg/m2 on days 1, 8, and 15); those with fully platinum-sensitive disease received platinum-based chemotherapy (single-agent cisplatin or carboplatin, or platinum-doublet chemotherapy). Patients were treated in 21-day or 28-day cycles. The primary endpoint was investigator-assessed progression-free survival, assessed in the efficacy population (all randomly assigned patients with deleterious BRCA1 or BRCA2 mutations without reversion mutations), and then in the intention-to-treat population (all randomly assigned patients). Safety was assessed in all patients who received at least one dose of assigned study treatment. This study is registered with ClinicalTrials.gov, NCT02855944; enrolment is complete, and the study is ongoing.
Between March 1, 2017, and Sept 24, 2020, 930 patients were screened, of whom 349 eligible patients were randomly assigned to rucaparib (n=233) or chemotherapy (n=116). Median age was 58 years (IQR 52–64) and 332 (95%) patients were White. As of data cutoff (Sept 30, 2020), median follow-up was 25·0 months (IQR 13·8–32·5). In the efficacy population (220 patients in the rucaparib group; 105 in the chemotherapy group), median progression-free survival was 7·4 months (95% CI 7·3–9·1) in the rucaparib group versus 5·7 months (5·5–7·3) in the chemotherapy group (hazard ratio HR 0·64 95% CI 0·49–0·84; p=0·0010). In the intention-to-treat population (233 in the rucaparib group; 116 in the chemotherapy group), median progression-free survival was 7·4 months (95% CI 6·7–7·9) in the rucaparib group versus 5·7 months (5·5–6·7) in the chemotherapy group (HR 0·67 95% CI 0·52–0·86; p=0·0017). Most treatment-emergent adverse events were grade 1 or 2. The most common grade 3 or worse treatment-emergent adverse event was anaemia or decreased haemoglobin (in 52 22% of 232 patients in the rucaparib group vs six 5% of 113 in the chemotherapy group). Serious treatment-emergent adverse events occurred in 62 (27%) patients in the rucaparib group versus 13 (12%) in the chemotherapy group; serious adverse events considered related to treatment by the investigator occurred in 32 (14%) patients in the rucaparib group and six (5%) in the chemotherapy group. Three deaths were considered to be potentially related to rucaparib (one due to cardiac disorder, one due to myelodysplastic syndrome, and one with an unconfirmed cause).
Results from the ARIEL4 study support rucaparib as an alternative treatment option to chemotherapy for patients with relapsed, BRCA1-mutated or BRCA2-mutated ovarian carcinoma.
Clovis Oncology.
Abstract
Background
About 20% of breast cancers in humans are basal-like, a subtype that is often triple-negative and difficult to treat. An effective translational model for basal-like breast cancer ...is currently lacking and urgently needed. To determine whether spontaneous mammary tumors in pet dogs could meet this need, we subtyped canine mammary tumors and evaluated the dog–human molecular homology at the subtype level.
Methods
We subtyped 236 canine mammary tumors from 3 studies by applying various subtyping strategies on their RNA-seq data. We then performed PAM50 classification with canine tumors alone, as well as with canine tumors combined with human breast tumors. We identified feature genes for human BLBC and luminal A subtypes via machine learning and used these genes to repeat canine-alone and cross-species tumor classifications. We investigated differential gene expression, signature gene set enrichment, expression association, mutational landscape, and other features for dog–human subtype comparison.
Results
Our independent genome-wide subtyping consistently identified two molecularly distinct subtypes among the canine tumors. One subtype is mostly basal-like and clusters with human BLBC in cross-species PAM50 and feature gene classifications, while the other subtype does not cluster with any human breast cancer subtype. Furthermore, the canine basal-like subtype recaptures key molecular features (e.g., cell cycle gene upregulation, TP53 mutation) and gene expression patterns that characterize human BLBC. It is enriched in histological subtypes that match human breast cancer, unlike the other canine subtype. However, about 33% of canine basal-like tumors are estrogen receptor negative (ER−) and progesterone receptor positive (PR+), which is rare in human breast cancer. Further analysis reveals that these ER−PR+ canine tumors harbor additional basal-like features, including upregulation of genes of interferon-
γ
response and of the Wnt-pluripotency pathway. Interestingly, we observed an association of
PGR
expression with gene silencing in all canine tumors and with the expression of T cell exhaustion markers (e.g.,
PDCD1
) in ER−PR+ canine tumors.
Conclusions
We identify a canine mammary tumor subtype that molecularly resembles human BLBC overall and thus could serve as a vital translational model of this devastating breast cancer subtype. Our study also sheds light on the dog–human difference in the mammary tumor histology and the hormonal cycle.
Transactivation response DNA-binding protein 43 (TDP-43) proteinopathy has recently been reported in chronic traumatic encephalopathy, a neurodegenerative condition linked to prior history of ...traumatic brain injury (TBI). While TDP-43 appears to be vulnerable to proteolytic modifications under neurodegenerative conditions, the mechanism underlying the contribution of TDP-43 to the pathogenesis of TBI remains unknown. In this study, we first mapped out the calpain or caspase-3 TDP-43 fragmentation patterns by in vitro protease digestion. Concurrently, in cultured cerebrocortical neurons subjected to cell death challenges, we identified distinct TDP-43 breakdown products (BDPs) of 35, 33, and 12kDa that were indicative of dual calpain/caspase attack. Cerebrocortical culture incubated with calpain and caspase-fragmented TDP-43 resulted in neuronal injury. Furthermore, increased TDP-43 BDPs as well as redistributed TDP-43 from the nucleus to the cytoplasm were observed in the mouse cortex in two TBI models: controlled cortical impact injury and overpressure blast-wave-induced brain injury. Finally, TDP-43 and its 35 kDa fragment levels were also elevated in the cerebrospinal fluid (CSF) of severe TBI patients. This is the first evidence that TDP-43 might be involved in acute neuroinjury and TBI pathology, and that TDP-43 and its fragments may have biomarker utilities in TBI patients.
Summary Background Poly(ADP-ribose) polymerase (PARP) inhibitors have activity in ovarian carcinomas with homologous recombination deficiency. Along with BRCA1 and BRCA2 (BRCA) mutations genomic loss ...of heterozygosity (LOH) might also represent homologous recombination deficiency. In ARIEL2, we assessed the ability of tumour genomic LOH, quantified with a next-generation sequencing assay, to predict response to rucaparib, an oral PARP inhibitor. Methods ARIEL2 is an international, multicentre, two-part, phase 2, open-label study done at 49 hospitals and cancer centres in Australia, Canada, France, Spain, the UK, and the USA. In ARIEL2 Part 1, patients with recurrent, platinum-sensitive, high-grade ovarian carcinoma were classified into one of three predefined homologous recombination deficiency subgroups on the basis of tumour mutational analysis: BRCA mutant (deleterious germline or somatic), BRCA wild-type and LOH high (LOH high group), or BRCA wild-type and LOH low (LOH low group). We prespecified a cutoff of 14% or more genomic LOH for LOH high. Patients began treatment with oral rucaparib at 600 mg twice per day for continuous 28 day cycles until disease progression or any other reason for discontinuation. The primary endpoint was progression-free survival. All patients treated with at least one dose of rucaparib were included in the safety analyses and all treated patients who were classified were included in the primary endpoint analysis. This trial is registered with ClinicalTrials.gov , number NCT01891344 . Enrolment into ARIEL2 Part 1 is complete, although an extension (Part 2) is ongoing. Findings 256 patients were screened and 206 were enrolled between Oct 30, 2013, and Dec 19, 2014. At the data cutoff date (Jan 18, 2016), 204 patients had received rucaparib, with 28 patients remaining in the study. 192 patients could be classified into one of the three predefined homologous recombination deficiency subgroups: BRCA mutant (n=40), LOH high (n=82), or LOH low (n=70). Tumours from 12 patients were established as BRCA wild-type, but could not be classified for LOH, because of insufficient neoplastic nuclei in the sample. The median duration of treatment for the 204 patients was 5·7 months (IQR 2·8–10·1). 24 patients in the BRCA mutant subgroup, 56 patients in the LOH high subgroup, and 59 patients in the LOH low subgroup had disease progression or died. Median progression-free survival after rucaparib treatment was 12·8 months (95% CI 9·0–14·7) in the BRCA mutant subgroup, 5·7 months (5·3–7·6) in the LOH high subgroup, and 5·2 months (3·6–5·5) in the LOH low subgroup. Progression-free survival was significantly longer in the BRCA mutant (hazard ratio 0·27, 95% CI 0·16–0·44, p<0·0001) and LOH high (0·62, 0·42–0·90, p=0·011) subgroups compared with the LOH low subgroup. The most common grade 3 or worse treatment-emergent adverse events were anaemia or decreased haemoglobin (45 22% patients), and elevations in alanine aminotransferase or aspartate aminotransferase (25 12%). Common serious adverse events included small intestinal obstruction (10 5% of 204 patients), malignant neoplasm progression (10 5%), and anaemia (nine 4%). Three patients died during the study (two because of disease progression and one because of sepsis and disease progression). No treatment-related deaths occurred. Interpretation In patients with BRCA mutant or BRCA wild-type and LOH high platinum-sensitive ovarian carcinomas treated with rucaparib, progression-free survival was longer than in patients with BRCA wild-type LOH low carcinomas. Our results suggest that assessment of tumour LOH can be used to identify patients with BRCA wild-type platinum-sensitive ovarian cancers who might benefit from rucaparib. These results extend the potential usefulness of PARP inhibitors in the treatment setting beyond BRCA mutant tumours. Funding Clovis Oncology, US Department of Defense Ovarian Cancer Research Program, Stand Up To Cancer—Ovarian Cancer Research Fund Alliance—National Ovarian Cancer Coalition Dream Team Translational Research Grant, and V Foundation Translational Award.
A key resistance mechanism to platinum-based chemotherapies and PARP inhibitors in
-mutant cancers is the acquisition of
reversion mutations that restore protein function. To estimate the prevalence ...of
reversion mutations in high-grade ovarian carcinoma (HGOC), we performed targeted next-generation sequencing of circulating cell-free DNA (cfDNA) extracted from pretreatment and postprogression plasma in patients with deleterious germline or somatic
mutations treated with the PARP inhibitor rucaparib.
reversion mutations were identified in pretreatment cfDNA from 18% (2/11) of platinum-refractory and 13% (5/38) of platinum-resistant cancers, compared with 2% (1/48) of platinum-sensitive cancers (
= 0.049). Patients without
reversion mutations detected in pretreatment cfDNA had significantly longer rucaparib progression-free survival than those with reversion mutations (median, 9.0 vs. 1.8 months; HR, 0.12;
< 0.0001). To study acquired resistance, we sequenced 78 postprogression cfDNA, identifying eight additional patients with
reversion mutations not found in pretreatment cfDNA. SIGNIFICANCE:
reversion mutations are detected in cfDNA from platinum-resistant or platinum-refractory HGOC and are associated with decreased clinical benefit from rucaparib treatment. Sequencing of cfDNA can detect multiple
reversion mutations, highlighting the ability to capture multiclonal heterogeneity.
.
The lack of blood-brain barrier (BBB) penetrating ability has hindered the delivery of many therapeutic agents for tauopathy treatment. In this study, we report the synthesis of a circular ...bifunctional aptamer to enhance the in vivo BBB penetration for better tauopathy therapy. The circular aptamer consists of one reported transferrin receptor (TfR) aptamer to facilitate TfR-aptamer recognition-induced transcytosis across BBB endothelial cells, and one Tau protein aptamer that we recently selected to inhibit Tau phosphorylation and other tauopathy-related pathological events in the brain. This novel circular Tau-TfR bifunctional aptamer displays significantly improved plasma stability and brain exposure, as well as the ability to disrupt tauopathy and improve traumatic brain injury (TBI)-induced cognitive/memory deficits in vivo, providing important proof-of-principle evidence that circular Tau-TfR aptamer can be further developed into diagnostic and therapeutic candidates for tauopathies.
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