PUMA amplifies necroptosis signaling by activating cytosolic DNA sensors.

Necroptosis, a form of regulated necrotic cell death, is governed by RIP1/RIP3-mediated activation of MLKL. However, the signaling process leading to necroptotic death remains to be elucidated. In this study, we found that PUMA, a proapoptotic BH3-only Bcl-2 family member, is transcriptionally activated in an RIP3/MLKL-dependent manner following induction of necroptosis. The induction of PUMA, which is mediated by autocrine TNF-α and enhanced NF-κB activity, contributes to necroptotic death in RIP3-expressing cells with caspases inhibited. On induction, PUMA promotes the cytosolic release of mitochondrial DNA and activation of the DNA sensors DAI/Zbp1 and STING, leading to enhanced RIP3 and MLKL phosphorylation in a positive feedback loop. Furthermore, deletion of PUMA partially rescues necroptosis-mediated developmental defects in FADD-deficient embryos. Collectively, our results reveal a signal amplification mechanism mediated by PUMA and cytosolic DNA sensors that is involved in TNF-driven necroptotic death in vitro and in vivo

Editorial: Biomarkers, functional mechanisms, and therapeutic potentials in gastrointestinal cancers

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Cell Growth Measurement

The cell is the basic structural and functional unit of all living organisms. As the smallest unit and building blocks of life, cells differ in size, shape, metabolism, reproduction, and growth requirements. Cells reproduce through cell division involving a four-phase (G1, S, G2, M) cell cycle, which is tightly regulated at multiple checkpoints. The resulting growth curve demonstrates that cell population increases in three sequential steps: incubation, exponential hyperplasia, and stagnation/death phases. Cell growth is subject to changes in disease state and/or environmental conditions. This chapter will focus on methods for cell growth measurement, which are grouped into five sections: cell cycle, apoptosis, growth curve, drug-induced proliferation (DIP), and continuous assays. Among the continuous assays, the EZMTT dye allows for long-term tracking of cell growth under various conditions and shows promise in precision medicine by early detection of drug resistance

Loss‐of‐Function Genetic Screening Identifies Aldolase A as an Essential Driver for Liver Cancer Cell Growth Under Hypoxia

Background and aims: Hypoxia is a common feature of the tumor microenvironment (TME), which promotes tumor progression, metastasis, and therapeutic drug resistance through a myriad of cell activities in tumor and stroma cells. While targeting hypoxic TME is emerging as a promising strategy for treating solid tumors, preclinical development of this approach is lacking in the study of HCC. Approach and results: From a genome-wide CRISPR/CRISPR-associated 9 gene knockout screening, we identified aldolase A (ALDOA), a key enzyme in glycolysis and gluconeogenesis, as an essential driver for HCC cell growth under hypoxia. Knockdown of ALDOA in HCC cells leads to lactate depletion and consequently inhibits tumor growth. Supplementation with lactate partly rescues the inhibitory effects mediated by ALDOA knockdown. Upon hypoxia, ALDOA is induced by hypoxia-inducible factor-1α and fat mass and obesity-associated protein-mediated N6 -methyladenosine modification through transcriptional and posttranscriptional regulation, respectively. Analysis of The Cancer Genome Atlas shows that elevated levels of ALDOA are significantly correlated with poor prognosis of patients with HCC. In a screen of Food and Drug Administration-approved drugs based on structured hierarchical virtual platforms, we identified the sulfamonomethoxine derivative compound 5 (cpd-5) as a potential inhibitor to target ALDOA, evidenced by the antitumor activity of cpd-5 in preclinical patient-derived xenograft models of HCC. Conclusions: Our work identifies ALDOA as an essential driver for HCC cell growth under hypoxia, and we demonstrate that inhibition of ALDOA in the hypoxic TME is a promising therapeutic strategy for treating HCC

Multiple ITS Copies Reveal Extensive Hybridization within Rheum (Polygonaceae), a Genus That Has Undergone Rapid Radiation

During adaptive radiation events, characters can arise multiple times due to parallel evolution, but transfer of traits through hybridization provides an alternative explanation for the same character appearing in apparently non-sister lineages. The signature of hybridization can be detected in incongruence between phylogenies derived from different markers, or from the presence of two divergent versions of a nuclear marker such as ITS within one individual.In this study, we cloned and sequenced ITS regions for 30 species of the genus Rheum, and compared them with a cpDNA phylogeny. Seven species contained two divergent copies of ITS that resolved in different clades from one another in each case, indicating hybridization events too recent for concerted evolution to have homogenised the ITS sequences. Hybridization was also indicated in at least two further species via incongruence in their position between ITS and cpDNA phylogenies. None of the ITS sequences present in these nine species matched those detected in any other species, which provides tentative evidence against recent introgression as an explanation. Rheum globulosum, previously indicated by cpDNA to represent an independent origin of decumbent habit, is indicated by ITS to be part of clade of decumbent species, which acquired cpDNA of another clade via hybridization. However decumbent and glasshouse morphology are confirmed to have arisen three and two times, respectively.These findings suggested that hybridization among QTP species of Rheum has been extensive, and that a role of hybridization in diversification of Rheum requires investigation

RNA-binding protein RALY reprogrammes mitochondrial metabolism via mediating miRNA processing in colorectal cancer

Objective: Dysregulated cellular metabolism is a distinct hallmark of human colorectal cancer (CRC). However, metabolic programme rewiring during tumour progression has yet to be fully understood. Design: We analysed altered gene signatures during colorectal tumour progression, and used a complex of molecular and metabolic assays to study the regulation of metabolism in CRC cell lines, human patient-derived xenograft mouse models and tumour organoid models. Results: We identified a novel RNA-binding protein, RALY (also known as hnRNPCL2), that is highly associated with colorectal tumour aggressiveness. RALY acts as a key regulatory component in the Drosha complex, and promotes the post-transcriptional processing of a specific subset of miRNAs (miR-483, miR-676 and miR-877). These miRNAs systematically downregulate the expression of the metabolism-associated genes (ATP5I, ATP5G1, ATP5G3 and CYC1) and thereby reprogramme mitochondrial metabolism in the cancer cell. Analysis of The Cancer Genome Atlas (TCGA) reveals that increased levels of RALY are associated with poor prognosis in the patients with CRC expressing low levels of mitochondrion-associated genes. Mechanistically, induced processing of these miRNAs is facilitated by their N6-methyladenosine switch under reactive oxygen species (ROS) stress. Inhibition of the m6A methylation abolishes the RALY recognition of the terminal loop of the pri-miRNAs. Knockdown of RALY inhibits colorectal tumour growth and progression in vivo and in organoid models. Conclusions: Collectively, our results reveal a critical metabolism-centric role of RALY in tumour progression, which may lead to cancer therapeutics targeting RALY for treating CRC

E-commerce Adoption and Technical Efficiency of Wheat Production in China

Improving technical efficiency (TE) is crucial for the sustainable growth of smallholder agriculture in developing countries. While there has been a large literature investigating the determinants of smallholders’ agricultural technical efficiency, little is known about the effect of e-commerce on agriculture and crop production efficiency despite the growing importance of rural e-commerce in developing countries. This study, therefore, bridges the research gap by examining the impact of e-commerce adoption on TE using household survey data of wheat farmers in China. We employ the combination of propensity score matching (PSM) and a selectivity-corrected stochastic production frontier model to address the possible selection biases stemming from both observable and unobservable factors. We found that e-commerce adoption would lead to a 2.75 per cent increase in the technical efficiency of wheat production. Our study also complements the existing research of rural e-commerce, which mainly focuses on the benefits of e-commerce from the perspective of market opportunity and farmers’ welfare

E-commerce Adoption and Technical Efficiency of Wheat Production in China

Improving technical efficiency (TE) is crucial for the sustainable growth of smallholder agriculture in developing countries. While there has been a large literature investigating the determinants of smallholders’ agricultural technical efficiency, little is known about the effect of e-commerce on agriculture and crop production efficiency despite the growing importance of rural e-commerce in developing countries. This study, therefore, bridges the research gap by examining the impact of e-commerce adoption on TE using household survey data of wheat farmers in China. We employ the combination of propensity score matching (PSM) and a selectivity-corrected stochastic production frontier model to address the possible selection biases stemming from both observable and unobservable factors. We found that e-commerce adoption would lead to a 2.75 per cent increase in the technical efficiency of wheat production. Our study also complements the existing research of rural e-commerce, which mainly focuses on the benefits of e-commerce from the perspective of market opportunity and farmers’ welfare

Precise Measurement of Time Dependent Cell Growth and Detection of Partial Drug Resistance in Infectious Microbial

Antimicrobial drug resistance has become a serious public health problem. The current clinical diagnostic methods are turbidity-based assays that have been used for years to track bacterial growth; however, the method is relatively insensitive. To eliminate the new occurrence of drug resistance in infectious bacteria, we developed a highly sensitive EZMTT method for the antibiotic susceptibility test (AST) that magnified the cell growth signal and revealed partial drug resistance (showing 2–20% weak cell growth) that was not detected by the current turbidity assay within 24 h. By simply mixing the EZMTT dye with the bacterial culture and then following the growth by absorbance measurement at 450 nm, the drug-induced proliferation (DIP) rate can be obtained in a high-throughput-screening (HTS) mode with greater than 10-fold better sensitivity than the turbidity assay. The EZMTT-based DIP rate assay of 5 clinically isolated E. coli strains found approximately 30% more partial drug resistance than what was detected in the traditional turbidity-based assay. The observed partial drug resistance was further confirmed by mechanistic analyses. Therefore, a combination of the EZMTT dye and the current clinically used VITEK-type technology has great potential to help understand antimicrobial drug resistance and ultimately provide patients with precise medical care to prevent the occurrence of multidrug resistant bacteria