The success of immunotherapy using immune checkpoint inhibitors has changed the practice of cancer treatment tremendously. However, there are still many clinical challenges, such as drug resistance, ...predictive biomarker development, exploration of combination therapies, and prediction of immune-related adverse events in preclinical settings. To overcome these problems, it is essential to establish faithful preclinical mouse models that recapitulate the clinical features, molecular genetics, biological heterogeneity, and immune microenvironment of human cancers. Here we review the advantages and disadvantages of current preclinical mouse models, including syngeneic murine tumor cell lines, autochthonous tumor models, cancer cell line-derived xenografts, patient-derived-xenografts, and various kinds of immunologically humanized mice. We discuss how these models should be characterized and applied in preclinical settings, and how we should prepare preclinical studies for successful translation from bench to bedside.
High-grade urothelial cancer contains intrinsic molecular subtypes that exhibit differences in underlying tumor biology and can be divided into luminal-like and basal-like subtypes. We describe here ...the first subtype-specific murine models of bladder cancer and show that Upk3a-Cre
; Trp53
; Pten
; Rosa26
(UPPL, luminal-like) and BBN (basal-like) tumors are more faithful to human bladder cancer than the widely used MB49 cells. Following engraftment into immunocompetent C57BL/6 mice, BBN tumors were more responsive to PD-1 inhibition than UPPL tumors. Responding tumors within the BBN model showed differences in immune microenvironment composition, including increased ratios of CD8
:CD4
and memory:regulatory T cells. Finally, we predicted and confirmed immunogenicity of tumor neoantigens in each model. These UPPL and BBN models will be a valuable resource for future studies examining bladder cancer biology and immunotherapy.
This work establishes human-relevant mouse models of bladder cancer.
.
Recently, the emergence and rapid dissemination of extended-spectrum beta-lactamase (ESBL)-producing bacteria, particularly of the family Enterobacteriaceae, has posed serious healthcare challenges. ...Here, we determined the antimicrobial susceptibility and genetic characteristics of 164 Escherichia coli strains isolated from infected patients in two hospitals in Ghana. In total, 102 cefotaxime-resistant isolates (62.2%) were identified as ESBL-producers. Multilocus sequence typing of the ESBL-producers identified 20 different sequence types (STs) with ST131 (n = 25, 24.5%) as the dominant group. Other detected STs included ST410 (n = 21, 20.6%) and ST617 (n = 19, 18.6%). All identified ESBL-producers harbored bla
, bla
, or bla
, with bla
(n = 96, 94.1%) being the most predominant ESBL allele. Further analysis showed that the immediate genetic environment around bla
is conserved within bla
containing strains. Five of the 25 ST131 isolates were clustered with clade A, one with sub-clade C1, and 19 with the dominant sub-clade C2. The results show that fluoroquinolone-resistant, bla
- and bla
-producing ESBL E. coli ST131 strains belonging to clade A and sub-clades C1 and C2 are disseminating in Ghanaian hospitals. To the best of our knowledge, this is the first report of the ST131 phylogeny in Ghana.
Remarkable advances have recently been made in the development of Brain-Machine Interface (BMI) technologies for restoring or enhancing motor function. However, the application of these technologies ...may be limited to patients in static conditions, as these developments have been largely based on studies of animals (e.g., non-human primates) in constrained movement conditions. The ultimate goal of BMI technology is to enable individuals to move their bodies naturally or control external devices without physical constraints. Here, we demonstrate accurate decoding of muscle activity from electrocorticogram (ECoG) signals in unrestrained, freely behaving monkeys. We recorded ECoG signals from the sensorimotor cortex as well as electromyogram signals from multiple muscles in the upper arm while monkeys performed two types of movements with no physical restraints, as follows: forced forelimb movement (lever-pull task) and natural whole-body movement (free movement within the cage). As in previous reports using restrained monkeys, we confirmed that muscle activity during forced forelimb movement was accurately predicted from simultaneously recorded ECoG data. More importantly, we demonstrated that accurate prediction of muscle activity from ECoG data was possible in monkeys performing natural whole-body movement. We found that high-gamma activity in the primary motor cortex primarily contributed to the prediction of muscle activity during natural whole-body movement as well as forced forelimb movement. In contrast, the contribution of high-gamma activity in the premotor and primary somatosensory cortices was significantly larger during natural whole-body movement. Thus, activity in a larger area of the sensorimotor cortex was needed to predict muscle activity during natural whole-body movement. Furthermore, decoding models obtained from forced forelimb movement could not be generalized to natural whole-body movement, which suggests that decoders should be built individually and according to different behavior types. These results contribute to the future application of BMI systems in unrestrained individuals.
Klebsiella pneumoniae carbapenemase (KPC) producers are an emerging threat to global health, and the hospital water environment is considered an important reservoir of these life-threatening ...bacteria. We characterized plasmids of KPC-2-producing Citrobacter freundii and Klebsiella variicola isolates recovered from hospital sewage in Japan. Antimicrobial susceptibility testing, whole-genome sequencing analysis, bacterial conjugation, and transformation experiments were performed for both KPC-2 producers. The blaKPC-2 gene was located on the Tn3 transposon-related region from an IncP-6 replicon plasmid that could not be transferred via conjugation. Compared to the blaKPC-2-encoding plasmid of the C. freundii isolate, alignment analysis of plasmids with blaKPC-2 showed that the blaKPC-2-encoding plasmid of the K. variicola isolate was a novel IncP-6/IncF-like hybrid plasmid containing a 75,218-bp insertion sequence composed of IncF-like plasmid conjugative transfer proteins. Carbapenem-resistant transformants harboring blaKPC-2 were obtained for both isolates. However, no IncF-like insertion region was found in the K. variicola donor plasmid of the transformant, suggesting that this IncF-like region is not readily functional for plasmid conjugative transfer and is maintained depending on the host cells. The findings on the KPC-2 producers and novel genetic content emphasize the key role of hospital sewage as a potential reservoir of pathogens and its linked dissemination of blaKPC-2 through the hospital water environment. Our results indicate that continuous monitoring for environmental emergence of antimicrobial-resistant bacteria might be needed to control the spread of these infectious bacteria. Moreover, it will help elucidate both the evolution and transmission pathways of these bacteria harboring antimicrobial resistance. IMPORTANCE Antimicrobial resistance is a significant problem for global health, and the hospital environment has been recognized as a reservoir of antimicrobial resistance. Here, we provide insight into the genomic features of blaKPC-2-harboring isolates of Citrobacter freundii and Klebsiella variicola obtained from hospital sewage in Japan. The findings of carbapenem-resistant bacteria containing this novel genetic context emphasize that hospital sewage could act as a potential reservoir of pathogens and cause the subsequent spread of blaKPC-2 via horizontal gene transfer in the hospital water environment. This indicates that serial monitoring for environmental bacteria possessing antimicrobial resistance may help us control the spread of infection and also lead to elucidating the evolution and transmission pathways of these bacteria.
Meningococcal chemoprophylaxis for people in close contact with patients with invasive meningococcal disease (IMD) is necessary for preventing the spread of Neisseria meningitidis. Ciprofloxacin ...(CIP) is commonly used to treat IMD. However, CIP-resistant N. meningitidis isolates have rapidly evolved worldwide; therefore, rapid and accurate detection of CIP-resistant N. meningitidis is essential. We developed a mismatch amplification mutation assay for identifying gyrA substitutions T91I and D95Y, associated with reduced CIP susceptibility, using two primer sets to detect these variants. Comparison with gyrA sequencing data showed complete congruency. This method enables reliable detection of CIP-resistant N. meningitidis, thus leading to efficient management and control of IMD infections.
Inactivation of the von Hippel-Lindau (VHL) E3 ubiquitin ligase protein is a hallmark of clear cell renal cell carcinoma (ccRCC). Identifying how pathways affected by VHL loss contribute to ccRCC ...remains challenging. We used a genome-wide in vitro expression strategy to identify proteins that bind VHL when hydroxylated. Zinc fingers and homeoboxes 2 (ZHX2) was found as a VHL target, and its hydroxylation allowed VHL to regulate its protein stability. Tumor cells from ccRCC patients with
loss-of-function mutations usually had increased abundance and nuclear localization of ZHX2. Functionally, depletion of ZHX2 inhibited VHL-deficient ccRCC cell growth in vitro and in vivo. Mechanistically, integrated chromatin immunoprecipitation sequencing and microarray analysis showed that ZHX2 promoted nuclear factor κB activation. These studies reveal ZHX2 as a potential therapeutic target for ccRCC.
We compared three screening methods for carbapenemase-producing Enterobacteriaceae. While the Modified-Hodge test and Carba NP test produced false-negative results for OXA-48-like and mucoid NDM ...producers, the carbapenem inactivation method (CIM) showed positive results for these isolates. Although the CIM required cultivation time, it is well suited for general clinical laboratories.
is emerging as an important human pathogen of concern especially strains with plasmid-mediated carbapenemase genes. The IncX3-
plasmid has been described as the primary vector for
dissemination. ...However, whether strains with this plasmid have any competitive edge remain largely unexplored. We characterized a
-producing
strain (KO_408) from Japan and sought to understand the driving force behind the recent dissemination of IncX3-
a
plasmids in different bacterial hosts. Antibiotic susceptibility testing, conjugation, and whole-genome sequencing were performed for KO_408, a clinical isolate recovered from a respiratory culture. Fitness, stability, and competitive assays were performed using the IncX3-
plasmid, pKO_4-NDM-5. KO_408 was ascribed to a novel sequence type, ST256, and harbored resistance genes conforming to its MDR phenotype. The
gene was localized on the ~44.9 kb IncX3 plasmid (pKO_4-NDM-5), which was transferable in the conjugal assay. The acquisition of pKO_4-NDM-5 did not impose any fitness burden and showed high stability in the host cells. However, transformants with pKO_4-NDM-5 were outcompeted by their host cells and transconjugants with the IncX3-
plasmid. The genetic environment of
in pKO_4-NDM-5 has been previously described. pKO_4-NDM-5 showed a close phylogenetic distance with seven similar plasmids from China. KO_408 clustered with strains within the KoI phylogroup, which is closely associated with carbapenemase genes. This study highlights the emergence of a high-risk
clone harboring carbapenemase genes and affirms that the recent spread of IncX3-
plasmids might be due to their low fitness cost and stability but not their competitive prowess.
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