Adipose-derived stem cells promote glycolysis and peritoneal metastasis via TGF-ß1/SMAD3/ANGPTL4 axis in colorectal cancer.

Peritoneal metastasis, the third most common metastasis in colorectal cancer (CRC), has a poor prognosis for the rapid progression and limited therapeutic strategy. However, the molecular characteristics and pathogenesis of CRC peritoneal metastasis are poorly understood. Here, we aimed to elucidate the action and mechanism of adipose-derived stem cells (ADSCs), a prominent component of the peritoneal microenvironment, in CRC peritoneal metastasis formation. Database analysis indicated that ADSCs infiltration was increased in CRC peritoneal metastases, and high expression levels of ADSCs marker genes predicted a poor prognosis. Then we investigated the effect of ADSCs on CRC cells in vitro and in vivo. The results revealed that CRC cells co-cultured with ADSCs exhibited stronger metastatic property and anoikis resistance, and ADSCs boosted the intraperitoneal seeding of CRC cells. Furthermore, RNA sequencing was carried out to identify the key target gene, angiopoietin like 4 (ANGPTL4), which was upregulated in CRC specimens, especially in peritoneal metastases. Mechanistically, TGF-ß1 secreted by ADSCs activated SMAD3 in CRC cells, and chromatin immunoprecipitation assay showed that SMAD3 facilitated ANGPTL4 transcription by directly binding to ANGPTL4 promoter. The ANGPTL4 upregulation was essential for ADSCs to promote glycolysis and anoikis resistance in CRC. Importantly, simultaneously targeting TGF-ß signaling and ANGPTL4 efficiently reduced intraperitoneal seeding in vivo. In conclusion, this study indicates that tumor-infiltrating ADSCs promote glycolysis and anoikis resistance in CRC cells and ultimately facilitate peritoneal metastasis via the TGF-ß1/SMAD3/ANGPTL4 axis. The dual-targeting of TGF-ß signaling and ANGPTL4 may be a feasible therapeutic strategy for CRC peritoneal metastasis.

Trained quantity discrimination in invasive red-eared slider and a comparison with the native stripe-necked turtle.

Little is known about the behavioral and cognitive traits that best predict invasion success. Evidence is mounting that cognitive performance correlates with survival and fecundity, two pivotal factors for the successful establishment of invasive populations. We assessed the quantity discrimination ability of the globally invasive red-eared slider (Trachemys scripta elegans). We further compared it to that of the native stripe-necked turtle (Mauremys sinensis), which has been previously evaluated for its superior quantity discrimination ability. Specifically, our experimental designs aimed to quantify the learning ability as numerosity pairs increased in difficulty (termed fixed numerosity tests), and the immediate response when turtles were presented with varied challenges concurrently in the same tests (termed mixed numerosity tests). Our findings reaffirm the remarkable ability of freshwater turtles to discern numerical differences as close as 9 vs 10 (ratio = 0.9), which was comparable to the stripe-necked turtle's performance. However, the red-eared slider exhibited a moderate decrease in performance in high ratio tests, indicating a potentially enhanced cognitive capacity to adapt to novel challenges. Our experimental design is repeatable and is adaptable to a range of freshwater turtles. These findings emphasize the potential importance of cognitive research to the underlying mechanisms of successful species invasions.

MACC1 and Gasdermin-E (GSDME) regulate the resistance of colorectal cancer cells to irinotecan.

Metastasis-associated in colon cancer 1 (MACC1) is an oncogene associated with the progression and metastasis of many solid cancer entities. High expression of MACC1 is found in colorectal cancer (CRC) tissues. So far, the role of MACC1 in CRC cell pyroptosis and resistance to irinotecan is unclear. The cleavage of Gasdermin-E (GSDME) is the main executors of activated pyroptosis. We found that GSDME enhanced CRC cell pyroptosis and reduced their resistance to irinotecan, while MACC1 inhibited the cleavage of GSDME and CRC cell pyroptosis, promoted CRC cell proliferation, and enhanced the resistance of CRC cells to irinotecan. Therefore, CRC cells with high MACC1 expression and low GSDME expression had higher resistance to irinotecan, while CRC cells with low MACC1 expression and high GSDME expression had lower resistance to irinotecan. Consistently, by analyzing CRC patients who received FOLFIRI (Fluorouracil + Irinotecan + Leucovorin) in combination with chemotherapy in the GEO database, we found that CRC patients with low MACC1 expression and high GSDME expression had higher survival rate. Our study suggests that the expression of MACC1 and GSDME can be used as detection markers to divide CRC patients into irinotecan resistant and sensitive groups, helping to determine the treatment strategy of patients.

NF-κB Activator 1 downregulation in macrophages activates STAT3 to promote adenoma-adenocarcinoma transition and immunosuppression in colorectal cancer.

BACKGROUND: Adenoma-adenocarcinoma transition is a key feature of colorectal cancer (CRC) occurrence and is closely regulated by tumor-associated macrophages (TAMs) and CD8+ T cells. Here, we investigated the effect of the NF-κB activator 1 (Act1) downregulation of macrophages in the adenoma-adenocarcinoma transition. METHODS: This study used spontaneous adenoma-developing ApcMin/+, macrophage-specific Act1-knockdown (anti-Act1), and ApcMin/+; anti-Act1 (AA) mice. Histological analysis was performed on CRC tissues of patients and mice. CRC patients' data retrieved from the TCGA dataset were analyzed. Primary cell isolation, co-culture system, RNA-seq, and fluorescence-activated cell sorting (FACS) were used. RESULTS: By TCGA and TISIDB analysis, the downregulation of Act1 expression in tumor tissues of CRC patients negatively correlated with accumulated CD68+ macrophages in the tumor. Relative expression of EMT markers in the tumor enriched ACT1lowCD68+ macrophages of CRC patients. AA mice showed adenoma-adenocarcinoma transition, TAMs recruitment, and CD8+ T cell infiltration in the tumor. Macrophages depletion in AA mice reversed adenocarcinoma, reduced tumor amounts, and suppressed CD8+ T cell infiltration. Besides, macrophage depletion or anti-CD8a effectively inhibited metastatic nodules in the lung metastasis mouse model of anti-Act1 mice. CRC cells induced activation of IL-6/STAT3 and IFN-γ/NF-κB signaling and the expressions of CXCL9/10, IL-6, and PD-L1 in anti-Act1 macrophages. Anti-Act1 macrophages facilitated epithelial-mesenchymal-transition and CRC cells' migration via CXCL9/10-CXCR3-axis. Furthermore, anti-Act1 macrophages promoted exhaustive PD1+ Tim3+ CD8+ T cell formation. Anti-PD-L1 treatment repressed adenoma-adenocarcinoma transition in AA mice. Silencing STAT3 in anti-Act1 macrophages reduced CXCL9/10 and PD-L1 expression and correspondingly inhibited epithelial-mesenchymal-transition and CRC cells' migration. CONCLUSIONS: Act1 downregulation in macrophages activates STAT3 that promotes adenoma-adenocarcinoma transition via CXCL9/10-CXCR3-axis in CRC cells and PD-1/PD-L1-axis in CD8+ T cells.

Blockade of IL-6 inhibits tumor immune evasion and improves anti-PD-1 immunotherapy.

Long-standing inflammatory bowel disease predisposes to the development of colorectal cancer (CRC). Interleukin (IL) -6, a pivotal link between chronic inflammation and tumor progression, has recently been recognized as a potential therapeutic target. The effect of IL-6 on proliferation and metastasis of CRC by activating the STAT3 pathway has been widely demonstrated in recent years, but few on mediating tumor immune evasion. In this study, we found that IL-6 was remarkably overexpressed in CRC and its elevation was associated with a poor prognosis. We studied CRC tumorigenesis in vivo by inoculating MC38 tumors and induced-CRC model via AOM/DSS (azoxymethane/dextransulfate sodium) in IL-6 deficient (IL-6-/-) and wild-type (WT) mice and found that IL-6-/- mice were less susceptible to develop tumors, compared to WT mice. We detected CD8+ T cells via immunofluorescence and found they exhibit high expression in tumor of IL-6-/- mice. High level of IL-6 was found in colitis model, with down-regulation of MHC-I molecules. In in vitro experiments, we found that IL-6 may act as a negative regulator in IFNγ-STAT1-MHC-I signaling. In addition, vivo trials also confirmed that MHC-I mRNA level was negatively related to the existence of IL-6. Furthermore, the blockade of IL-6 also activated CD8+T-cell accumulation and led to the high PD-L1 expression in CRC, which can sensitize animals to anti-PD-1 therapy. Our study provides a research basis for the significant role of IL-6 in tumor evasion and highlights a novel target to improve the efficacy of immunotherapy.

Highly rapid and diverse sex chromosome evolution in the Odorrana frog species complex.

Sex chromosomes in poikilothermal vertebrates are characterized by rapid and diverse evolution at the species or population level. Our previous study revealed that the Taiwanese frog Odorrana swinhoana (2n = 26) has a unique system of multiple sex chromosomes created by three sequential translocations among chromosomes 1, 3, and 7. To reveal the evolutionary history of sex chromosomes in the Odorrana species complex, we first identified the original, homomorphic sex chromosomes, prior to the occurrence of translocations, in the ancestral-type population of O. swinhoana. Then, we extended the investigation to a closely related Japanese species, Odorrana utsunomiyaorum, which is distributed on two small islands. We used a high-throughput nuclear genomic approach to analyze single-nucleotide polymorphisms and identify the sex-linked markers. Those isolated from the O. swinhoana ancestral-type population were found to be aligned to chromosome 1 and showed male heterogamety. In contrast, almost all the sex-linked markers isolated from O. utsunomiyaorum were heterozygous in females and homozygous in males and were aligned to chromosome 9. Morphologically, we confirmed chromosome 9 to be heteromorphic in females, showing a ZZ-ZW sex determination system, in which the W chromosomes were heterochromatinized in a stripe pattern along the chromosome axis. These results indicated that after divergence of the two species, the ancestral homomorphic sex chromosome 1 underwent highly rapid and diverse evolution, i.e., sequential translocations with two autosomes in O. swinhoana, and turnover to chromosome 9 in O. utsunomiyaorum, with a transition from XY to ZW heterogamety and change to heteromorphy.

One Fluorophore-Two Sensing Films: Hydrogen-Bond Directed Formation of a Quadruple Perylene Bisimide Stack.

Elaborately designed π-stacked molecular aggregates are significant for modulation of photophysical properties of polycyclic aromatic hydrocarbons (PAHs). Herein, a double hydrogen-bonds trussed di(pyridyl)pyrrole-perylene bisimide (HDPP-PBI) was designed and its dimerization behavior was studied. HDPP-PBI tends to form a quadruple PBI stack with a dimerization constant of ∼5.56×106  M-1 . The dimerization was ascribed to synergistic intramolecular double hydrogen-bonds formation and intermolecular π-π stacking. Addition of CF3 COOH, a hydrogen bond blocker, promotes the dimer to monomer transition. Accordingly, two distinct fluorescent films were prepared by drop-casting of the dimerized or the monomeric HDPP-PBI onto a substrate surface. Interestingly, the less-emissive PBI quadruple stack-based film showed a turn on response to acetone vapor, while the highly emissive HDPP-PBI-based film exhibited fluorescence quenching upon exposure to triethylamine vapor. We believe that the discovered synergistic effect in the PBI aggregates would enlighten the design of new PAHs aggregates with defined structures.

Study on the levels of N-nitrosamine compounds and untargeted metabolomics in patients with colorectal cancer.

Plasma samples were collected from 34 patients with advanced CRC and 92 healthy persons (control group), and the levels of 9 VNAs were measured using GC-MS. Untargeted metabolomics analysis was performed using LC-MS/MS. Partial least squares discriminant analysis (PLS-DA) and hierarchical cluster analysis were used to determine differential metabolites between the 2 groups. Receiver operating characteristic (ROC) curve analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis were performed on the differential metabolites. It turned out that the detection rates of N-nitrosodimethylamine (NDMA) and N-nitrosopyrrolidine (NPYR) in patients with CRC were higher than in the control group (P < 0.05). N-nitrosomethylethylamine (NMEA) and N-nitrosodiphenylamine (NDPhA) were not detected in CRC patients. NDMA, N-nitrosodibutylamine (NDBA), N-nitrosopiperidine (NPIP), and NPYR were detected in male and female patients with CRC. There was no difference in VNAs exposure between the sexes of CRC patients. In the positive and negative ion mode, a total of 132 differential metabolites and 6 differential metabolic pathways were detected. Adenosine 5'-monophosphate, hypoxanthine, 11,12-epoxy-(5Z,8Z,11Z)-icosatrienoic acid, 16(R)-HETE, acetylcarnitine, and lysophosphatidic acid (LPA 20:5, LPA 20:4) were candidate biomarkers with higher predictive value. Hypoxanthine and xanthine metabolic pathways were associated with changes in VNAs in CRC patients. In summary, the effects of changes of VNAs in the plasma of CRC patients (especially NDMA and NPYR) on the progression of CRC should attract attention. Abnormalities of adenine and guanine and downstream hypoxanthine-xanthine metabolic pathways were closely related to changes of VNAs and metabolomics in CRC patients.

Through-Space Charge Transfer: A New Way to Develop a High-Performance Fluorescence Sensing Film towards Opto-Electronically Inert Alkanes.

New strategies are in high demand for fast, sensitive, selective, on-site and real-time detection of the important but challenging alkane vapors owing to their opto-electronic inertness. Herein, we report, for the first time, a high-performance fluorescent film sensor (FFS) for the alkanes with a rationally designed through-space charge transfer (TSCT) molecule as the sensing fluorophore. Steady-state fluorescence, femto-second transient absorption spectroscopy and theoretical studies revealed continuous TSCT dynamics in the excited U-shaped molecule with increasing medium polarity. Furthermore, the interlocked, face-to-face alignment between the donor and acceptor favors mass transport of the analyte molecules in the film state. As anticipated, the compound-based FFS showed an experimental detection limit of ≈10 ppm for n-pentane, less than 5 s for a full detection, negligible interference and super-stability, revealing the effectiveness of the design strategy. Notably, the sensor is small (≈3.7 cm3 ), power-saving, and workable at room temperature.

High-Performance NMHC Detection Enabled by a Perylene Bisimide-Cored Metallacycle Complex-Based Fluorescent Film Sensor.

Non-methane hydrocarbons (NMHCs) can serve as precursors of ozone and photochemical smog, and hence their highly efficient detection is of great importance for air quality monitoring. Here, we synthesized a new fluorescent perylene bisimide (PBI)-cored metallacycle complex through coordination-driven self-assembly and used it for the production of a fluorescent film sensor. The unique rectangular structure of the developed fluorophore endows the sensor with enhanced sensing performance and discriminability to n-alkanes (C5-10). Specifically, the experimental detection limits for n-pentane, n-hexane, and n-decane are 39, 7, and 1.4 mg/m3, respectively, and the corresponding linear ranges are from 39 to 2546, 7 to 1745, and 1.4 to 85 mg/m3, respectively. Moreover, the sensing is fully reversible. In tandem with a gas chromatographic separation system, the film sensor showed comparable detection ability for the n-alkanes with a commercial flame ionization detector (FID), while the film sensor needs no hydrogen; it occupies a much smaller size (30 × 30 × 44 mm3) and consumes less energy (0.215 W). Further studies demonstrated that the developed sensor can be used for on-site and real-time quantification of NHMCs, laying the foundation for developing into a portable detector.

Perylene Bisimide-Cored Supramolecular Coordination Complexes: Interplay between Ensembles, Excited State Processes, and Aggregation Behaviors.

Manipulating the optical properties of fluorescent species is challenging owing to complicated and tedious synthetic works. Herein, the photophysical properties of perylene bisimide (PBI) were effectively tuned by varying the geometrical arrangement of PBI moieties within supramolecular coordination complexes (SCCs), where a PBI-based dicycle (2) and a trigonal prism (3) were generated via using a typical 90° Pt(II) reagent, cis-(PEt3 )2 Pt(OTf)2 -based coordination-driven self-assembly approach. The ligand, an ortho-tetrapyridiyl-PBI (1), exhibits a moderate fluorescence quantum yield (∼13 %) and efficient inter-system crossing (ISC). 2, however, is much more emissive with a fluorescence quantum yield of ∼41 %, and the relevant ISC process is significantly hindered. The fluorescence quantum yield of 3 is merely ∼6 % due to the observed symmetry-breaking charge separation (SB-CS), which turns to triplet state upon charge recombination. Interestingly, 3 could be fully transformed into 2 by simply adding a suitable amount of a 90° Pt(II)-based neutral triangle. Moreover, 2 tends to form discrete dimers both in crystal and solution states, but 3 does not show the property. Therefore, controlling geometrical arrangement of fluorophores through coordination-driven self-assembly could be taken as another effective way to tune their excited state relaxation pathways and construct high-performance optical molecular materials, which generally have to be prepared via organic synthesis.

Superior continuous quantity discrimination in a freshwater turtle.

BACKGROUND: Quantity discrimination, the ability to discriminate a magnitude of difference or discrete numerical information, plays a key role in animal behavior. While quantitative ability has been well documented in fishes, birds, mammals, and even in previously unstudied invertebrates and amphibians, it is still poorly understood in reptiles and has never been tested in an aquatic turtle despite the fact that evidence is accumulating that reptiles possess cognitive skills and learning ability. To help address this deficiency in reptiles, we investigated the quantitative ability of an Asian freshwater turtle, Mauremys sinensis, using red cubes on a white background in a trained quantity discrimination task. While spontaneous quantity discrimination methods are thought to be more ecologically relevant, training animals on a quantity discrimination task allows more comparability across taxa. RESULTS: We assessed the turtles' quantitative performance in a series of tests with increasing quantity ratios and numerosities. Surprisingly, the turtles were able to discriminate quantities of up to 9 versus 10 (ratio = 0.9), which shows a good quantitative ability that is comparable to some endotherms. Our results showed that the turtles' quantitative performance followed Weber's law, in which success rate decreased with increasing quantity ratio across a wide range of numerosities. Furthermore, the gradual improvement of their success rate across different experiments and phases suggested that the turtles possess learning ability. CONCLUSIONS: Reptile quantitative ability has long been ignored and therefore is likely under-estimated. More comparative research on numerical cognition across a diversity of species will greatly contribute to a clearer understanding of quantitative ability in animals and whether it has evolved convergently in diverse taxa.

Niche partitioning among three snail-eating snakes revealed by dentition asymmetry and prey specialisation.

The level of dentition asymmetry in snail-eating snakes may reflect their prey choice and feeding efficiency on asymmetric land snails. The three species of Pareas snakes (Squamata: Pareidae) in Taiwan, which form partially sympatric distribution on the island, provide a potential case to test the hypothesis of niche partitioning and character displacement with regard to dentition asymmetry and specialisation in feeding behaviour. In this study, behavioural experiments confirmed that P. formosensis feeds exclusively on slugs, whereas P. atayal and P. komaii consumed both. However, P. atayal more efficiently preys on land snails than P. komaii, exhibiting a shorter handling time and fewer mandibular retractions. Micro-CT and ancestral character reconstruction demonstrated the lowest asymmetry in P. formosensis (the slug specialist), the highest dentition asymmetry in P. atayal (the land snail specialist) and flexibility in P. komaii (the niche switcher): increased dentition asymmetry when sympatrically distributed with the slug eater (character displacement), and decreased asymmetry when living alone (ecological niche release). Ecological niche modelling showed that the distribution of P. formosensis is associated with the presence of slugs, while that of P. atayal could be explained by the land snails. Combining the results from morphology, phylogeny, behavioural experiments and ecological niche modelling, we showed that competition in the sympatric region might have facilitated character displacement among congeners, while the absence of competition in allopatric region has led to ecological niche release.

Do I stay or do I go? Shifts in perch use by lizards during morning twilight suggest anticipatory behaviour.

Anticipatory behaviour is the expectation of a near-future event based on information processed in the past and influences an animal's tactical decisions, particularly when there are significant fitness consequences. The grass lizard (Takydromus viridipunctatus) perches on blades of grass at night which likely reduces the probability of predation by terrestrial predators such as snakes, rodents and shrews. During twilight (starting 30 min before sunrise), they move from above the grass to within grass clumps and this is thought to afford the lizard protection while reducing detection by avian predators. Here, we examined how lizards shift their behaviour as a function of visual detectability to their primary predator, the cattle egret (Bubulcus ibis). We show that the lizards shift from their perch site during twilight at the earliest time at which egrets depart communal roosts. At the same time, visual modelling shows a dramatic increase in the detectability of the lizards to the visual system of egrets. Therefore, anticipatory behaviour in response to environmental cues acts to reduce predation risk as lizards become more conspicuous and predators become more active. Grass lizard anticipatory behaviour appears to be finely tuned by natural selection to adjust to temporal changes in predation risk.

Self-Assembled Perylene Bisimide-Cored Trigonal Prism as an Electron-Deficient Host for C60 and C70 Driven by "Like Dissolves Like".

Poor processability of fullerenes is a major remaining drawback for them to be studied monomolecularly and to find real-life applications. One of the strategies to tackle this problem is to encapsulate them within a host, which is however quite often, accompanied by significant alteration of their physical/chemical properties as encountered in chemical modification. To minimize the effect, an electron-deficient entities-based, dissolvable, and fluorescence active supramolecular host was designed and constructed via coordination-driven self-assembly of o-tetrapyridyl perylene bisimide (PBI) with cis-(PEt3)2Pt(OTf)2. The trigonal prism 1 possesses a trigonal-prismatic inner cavity with 14.7 Šas the diameter of its inscribed circle. Host-guest chemistry investigations revealed that both C60 and C70 could be quantitatively encapsulated by the host in a 1:1 ratio. Further studies demonstrated that the produced host-guest complex 1⊃C70 is significantly more stable than 1⊃C60, allowing complete transformation of the latter to the former and separation of C70 from its mixture with C60. The fullerenes in the inclusion state could rotate freely within the cavity. Electrochemistry and spectroscopy studies disclosed that the encapsulation of the guests shows little effect upon the reduction of the host and its fluorescence properties. Thus, "like dissolves like" is believed to be the main driving force for the formation of the host-guest complexes. Moreover, the host and host-guest complexes can be fabricated into monomolecular membranes using the conventional Langmuir-Blodgett technique. We propose that these unique host-guest complexes could be used as model ensembles for further studies of the physical/chemical properties of fullerenes in both single molecular and 2D membrane states. In addition, their reversible four-electron reduction property may allow them to find applications in photo/electrocatalysis, organic electronics, etc.

Engagement of Robo1 by Slit2 induces formation of a trimeric complex consisting of Src-Robo1-E-cadherin for E-cadherin phosphorylation and epithelial-mesenchymal transition.

Loss of E-cadherin elicits epithelial-mesenchymal transition (EMT). While both the Src family of membrane-associated non-receptor tyrosine kinases (SFKs) and Slit2 binding to Roundabout 1 (Robo1) have been shown to induce E-cadherin repression and EMT, whether these two signaling pathways are mechanistically coupled remains unknown in epithelial cells. Here we found that Slit2 and Robo1 overexpression activated Src kinases for tyrosine phosphorylation, degradation of E-cadherin and induction of EMT. Specific blockade of Slit2 binding to Robo1 inactivated Src, prevented E-cadherin phosphorylation and EMT induction. Biochemically, the cytoplasmic CC3 motif of Robo1 (CC3) bound directly to the SH2 and 3 domains of c-Src and the cytoplasmic domains of E-cadherin. Slit2 induced Robo1 association with endogenous c-Src and E-cadherin, whereas ectopic expression of CC3 dissociated this protein complex in colorectal epithelial cells. These results indicate that Slit2 not only induces Robo1 binding to Src, but also recruits Src to E-cadherin for tyrosine phosphorylation of E-cadherin, leading to E-cadherin degradation and EMT induction in colorectal epithelial cells.