Exo-miR-1290-induced by COX-2 overexpression promotes cancer-associated fibroblasts activation and tumor progression by CUL3-Nrf2 pathway in lung adenocarcinoma.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are critically involved in tumor progression by maintaining extracellular mesenchyma (ECM) production and improving tumor development. Cyclooxygenase-2 (COX-2) has been proved to promote ECM formation and tumor progression. However, the mechanisms of COX-2 mediated CAFs activation have not yet been elucidated. Therefore, we conducted this study to identify the effects and mechanisms of COX-2 underlying CAFs activation by tumor-derived exosomal miRNAs in lung adenocarcinoma (LUAD) progression. METHODS: As measures of CAFs activation, the expressions of fibroblasts activated protein-1 (FAP-1) and α-smooth muscle actin (α-SMA), the main CAFs markers, were detected by Western blotting and Immunohistochemistry. And the expression of Fibronectin (FN1) was used to analyze ECM production by CAFs. The exosomes were extracted by ultracentrifugation and exo-miRNAs were detected by qRT-PCR. Herein, we further elucidated the implicated mechanisms using online prediction software, luciferase reporter assays, co-immunoprecipitation, and experimental animal models. RESULTS: In vivo, a positive correlation was observed between the COX-2 expression levels in parenchyma and α-SMA/FN1 expression levels in mesenchyma in LUAD. However, PGE2, one of major product of COX-2, did not affect CAFs activation directly. COX-2 overexpression increased exo-miR-1290 expression, which promoted CAFs activation. Furthermore, Cullin3 (CUL3), a potential target of miR-1290, was found to suppress COX-2/exo-miR-1290-mediated CAFs activation and ECM production, consequently impeding tumor progression. CUL3 is identified to induce the Nuclear Factor Erythroid 2-Related Factor 2 (NFE2L2, Nrf2) ubiquitination and degradation, while exo-miR-1290 can prevent Nrf2 ubiquitination and increase its protein stability by targeting CUL3. Additionally, we identified that Nrf2 is direcctly bound with promoters of FAP-1 and FN1, which enhanced CAFs activation by promoting FAP-1 and FN1 transcription. CONCLUSIONS: Our data identify a new CAFs activation mechanism by exosomes derived from cancer cells that overexpress COX-2. Specifically, COX-2/exo-miR-1290/CUL3 is suggested as a novel signaling pathway for mediating CAFs activation and tumor progression in LUAD. Consequently, this finding suggests a novel strategy for cancer treatment that may tackle tumor progression in the future. Video Abstract.

Acute depletion of human core nucleoporin reveals direct roles in transcription control but dispensability for 3D genome organization.

The nuclear pore complex (NPC) comprises more than 30 nucleoporins (NUPs) and is a hallmark of eukaryotes. NUPs have been suggested to be important in regulating gene transcription and 3D genome organization. However, evidence in support of their direct roles remains limited. Here, by Cut&Run, we find that core NUPs display broad but also cell-type-specific association with active promoters and enhancers in human cells. Auxin-mediated rapid depletion of two NUPs demonstrates that NUP93, but not NUP35, directly and specifically controls gene transcription. NUP93 directly activates genes with high levels of RNA polymerase II loading and transcriptional elongation by facilitating full BRD4 recruitment to their active enhancers. dCas9-based tethering confirms a direct and causal role of NUP93 in gene transcriptional activation. Unexpectedly, in situ Hi-C and H3K27ac or H3K4me1 HiChIP results upon acute NUP93 depletion show negligible changesS2211-1247(22)01437-1 of 3D genome organization ranging from A/B compartments and topologically associating domains (TADs) to enhancer-promoter contacts.

Nomogram for predicting in-hospital mortality of nonagenarians with community-acquired pneumonia.

AIM: Nonagenarians with community-acquired pneumonia (CAP) have a high mortality rate; however, appropriate tools for reliable severity assessment in this population are lacking. The current study aimed to evaluate the risk factors and establish a nomogram to predict in-hospital mortality of nonagenarians with CAP. METHODS: In total, 304 patients aged ≥90 years who were admitted with CAP to Jiangsu Provincial People's Hospital and Jiangsu Provincial Hospital of Chinese Medicine between 2014 and 2020 were retrospectively analyzed. Clinical information, laboratory imaging results and pathogen detection were retrieved. Significant variables independently associated with CAP were identified by a logistic regression model, and a nomogram prediction model was constructed. The nomogram was compared with the widely used assessments: CURB-65, PSI and National Early Warning Score (NEWS) scores. RESULTS: Univariate and multivariate logistic regression analyses identified gender, blood urea nitrogen, C-reactive protein-to-albumin ratio, Charlson Comorbidity Index and systemic immune inflammation index as independent factors that affect the prognosis. We created a nomogram for CAP based on these risk factors. The nomogram had a bootstrapped concordance index of 0.796 and was well-calibrated in the decision analysis curve range of 0.1-0.98. The area under the curve was 0.796 (95% CI: 0.74-0.85), significantly higher than for CURB-65, PSI and NEWS scores (P < 0.05). CONCLUSIONS: Our nomogram model can predict the outcome of hospitalized nonagenarians with CAP and guide clinicians to provide better treatment, leading to improved prognosis and reduced mortality. Geriatr Gerontol Int 2022; 22: 635-641.

Association of blood glucose level and prognosis of inpatients with coexistent diabetes and COVID-19.

Type 2 diabetes (T2D) increases the risk of coronavirus disease (COVID-19). This study investigates the association between glucose control of COVID-19 patients with T2D in first 7 days after hospital admission and prognosis. A total of 252 infected inpatients with T2D in China were included. Well-controlled blood glucose was defined as stable fasting blood glucose (FBG) levels in the range of 3.9-7.8 mmol/L during first 7 days using indicators of average (FBGA), maximum (FBGM) or first-time (FBG1) FBG levels. The primary endpoint was admission to intensive care unit or death. Hazard ratio (HR) of poorly controlled glucose level group compared with well-controlled group were 4.96 (P = 0.021) for FBGM and 5.55 (P = 0.014) for FBGA. Well-controlled blood glucose levels in first 7 days could improve the prognosis of COVID-19 inpatients with diabetes.

Enhancer RNA m6A methylation facilitates transcriptional condensate formation and gene activation.

The mechanistic understanding of nascent RNAs in transcriptional control remains limited. Here, by a high sensitivity method methylation-inscribed nascent transcripts sequencing (MINT-seq), we characterized the landscapes of N6-methyladenosine (m6A) on nascent RNAs. We uncover heavy but selective m6A deposition on nascent RNAs produced by transcription regulatory elements, including promoter upstream antisense RNAs and enhancer RNAs (eRNAs), which positively correlates with their length, inclusion of m6A motif, and RNA abundances. m6A-eRNAs mark highly active enhancers, where they recruit nuclear m6A reader YTHDC1 to phase separate into liquid-like condensates, in a manner dependent on its C terminus intrinsically disordered region and arginine residues. The m6A-eRNA/YTHDC1 condensate co-mixes with and facilitates the formation of BRD4 coactivator condensate. Consequently, YTHDC1 depletion diminished BRD4 condensate and its recruitment to enhancers, resulting in inhibited enhancer and gene activation. We propose that chemical modifications of eRNAs together with reader proteins play broad roles in enhancer activation and gene transcriptional control.

Enhancer release and retargeting activates disease-susceptibility genes.

The functional engagement between an enhancer and its target promoter ensures precise gene transcription1. Understanding the basis of promoter choice by enhancers has important implications for health and disease. Here we report that functional loss of a preferred promoter can release its partner enhancer to loop to and activate an alternative promoter (or alternative promoters) in the neighbourhood. We refer to this target-switching process as 'enhancer release and retargeting'. Genetic deletion, motif perturbation or mutation, and dCas9-mediated CTCF tethering reveal that promoter choice by an enhancer can be determined by the binding of CTCF at promoters, in a cohesin-dependent manner-consistent with a model of 'enhancer scanning' inside the contact domain. Promoter-associated CTCF shows a lower affinity than that at chromatin domain boundaries and often lacks a preferred motif orientation or a partnering CTCF at the cognate enhancer, suggesting properties distinct from boundary CTCF. Analyses of cancer mutations, data from the GTEx project and risk loci from genome-wide association studies, together with a focused CRISPR interference screen, reveal that enhancer release and retargeting represents an overlooked mechanism that underlies the activation of disease-susceptibility genes, as exemplified by a risk locus for Parkinson's disease (NUCKS1-RAB7L1) and three loci associated with cancer (CLPTM1L-TERT, ZCCHC7-PAX5 and PVT1-MYC).

Implications of liver injury in risk-stratification and management of patients with COVID-19.

BACKGROUND: Infection with SARS-CoV-2 has been associated with liver dysfunction, aggravation of liver burden, and liver injury. This study aimed to assess the effects of liver injuries on the clinical outcomes of patients with COVID-19. METHODS: A total of 1520 patients with severe or critical COVID-19 from Huoshenshan Hospital, Wuhan, were enrolled. Chronic liver disease (CLD) was confirmed by consensus diagnostic criteria. Laboratory test results were compared between different groups. scRNA-seq data and bulk gene expression profiles were used to identify cell types associated with liver injury. RESULTS: A total of 10.98% of patients with severe or critical COVID-19 developed liver injury after admission that was associated with significantly higher rates of mortality (21.74%, p < 0.001) and intensive care unit admission (26.71%, p < 0.001). Pre-existing CLDs were not associated with a higher risk. However, fatty liver disease and cirrhosis were associated with higher risks, supported by evidences from single cell and bulk transcriptome analysis that showed more TMPRSS2+ cells in these tissues. By generating a model, we were able to predict the risk and severity of liver injury during hospitalization. CONCLUSION: We demonstrate that liver injury occurring during therapy as well as pre-existing CLDs like fatty liver disease and cirrhosis in patients with COVID-19 is significantly associated with the severity of disease and mortality, but the presence of other CLD is not associated. We provide a risk-score model that can predict whether patients with COVID-19 will develop liver injury or proceed to higher-risk stages during subsequent hospitalizations.

The SINEB1 element in the long non-coding RNA Malat1 is necessary for TDP-43 proteostasis.

Transposable elements (TEs) comprise a large proportion of long non-coding RNAs (lncRNAs). Here, we employed CRISPR to delete a short interspersed nuclear element (SINE) in Malat1, a cancer-associated lncRNA, to investigate its significance in cellular physiology. We show that Malat1 with a SINE deletion forms diffuse nuclear speckles and is frequently translocated to the cytoplasm. SINE-deleted cells exhibit an activated unfolded protein response and PKR and markedly increased DNA damage and apoptosis caused by dysregulation of TDP-43 localization and formation of cytotoxic inclusions. TDP-43 binds stronger to Malat1 without the SINE and is likely 'hijacked' by cytoplasmic Malat1 to the cytoplasm, resulting in the depletion of nuclear TDP-43 and redistribution of TDP-43 binding to repetitive element transcripts and mRNAs encoding mitotic and nuclear-cytoplasmic regulators. The SINE promotes Malat1 nuclear retention by facilitating Malat1 binding to HNRNPK, a protein that drives RNA nuclear retention, potentially through direct interactions of the SINE with KHDRBS1 and TRA2A, which bind to HNRNPK. Losing these RNA-protein interactions due to the SINE deletion likely creates more available TDP-43 binding sites on Malat1 and subsequent TDP-43 aggregation. These results highlight the significance of lncRNA TEs in TDP-43 proteostasis with potential implications in both cancer and neurodegenerative diseases.

Inhibition of lung cancer growth and metastasis by DHA and its metabolite, RvD1, through miR-138-5p/FOXC1 pathway.

BACKGROUND: Non small cell lung cancer (NSCLC) is one of the most common cancers in the world. DHA is known to be capable of suppressing NSCLC cell proliferation and metastasis. However, the mechanisms by which DHA exhibits its antitumor effects are unknown. Here we aimed to identify the effects and mechanisms of DHA and its metabolites on lung cancer cell growth and invasion. METHODS: As measures of cell proliferation and invasion ability, the cell viability and transwell assays were used in vitro. Transgenic mfat-1 mice, which convert ω-6 PUFAs to ω-3 PUFAs, were used to detect the effect of endogenous DHA on tumor transplantation. An LC - MS/MS analysis identified the elevation of several eicosanoid metabolites of DHA. By using qPCR miRNA microarray, online prediction software, luciferase reporter assays and Western blot analysis, we further elucidated the mechanisms. RESULTS: Addition of exogenous DHA inhibited the growth and invasion in NSCLC cells in vitro. Endogenously produced DHA attenuated LLC-derived tumor growth and metastasis in the transgenic mfat-1 mice. Among the elevation of DHA metabolites, resolvin D1 (RvD1) significantly contributed to the inhibition in cell growth and invasion. MiRNA microarray revealed that the level of miR-138-5p was significantly increased after RvD1 treatment. MiR-138-5p mimics decreased cell viability and invasion; while miR-138-5p inhibitor abolished RvD1-mediated suppression of cell viability and invasion. The expression of FOXC1 was significantly reduced upon overexpression of miR-138-5p while luciferase reporter assay showed that FOXC1 was a direct target of miR-138-5p. In vivo, endogenous DHA by the mfat-1 transgene enhanced miR-138-5p expression and decreased FOXC1 expression. Furthermore, overexpression of FOXC1 reversed the inhibition in cell viability and invasion induced by RvD1 treatment. CONCLUSIONS: These data identified the RvD1/miR-138-5p/FOXC1 pathway as a novel mechanism by DHA and its metabolite, RvD1, and the potential of targeting such pathway as a therapeutic strategy in treating NSCLC.

miRNA Mediated Noise Making of 3'UTR Mutations in Cancer.

Somatic mutations in 3'-untranslated regions (3'UTR) do not alter amino acids and are considered to be silent in cancers. We found that such mutations can promote tumor progression by altering microRNA (miRNA) targeting efficiency and consequently affecting miRNA⁻mRNA interactions. We identified 67,159 somatic mutations located in the 3'UTRs of messenger RNAs (mRNAs) which can alter miRNA⁻mRNA interactions (functional somatic mutations, funcMutations), and 69.3% of these funcMutations (the degree of energy change > 12 kcal/mol) were identified to significantly promote loss of miRNA-mRNA binding. By integrating mRNA expression profiles of 21 cancer types, we found that the expression of target genes was positively correlated with the loss of absolute affinity level and negatively correlated with the gain of absolute affinity level. Functional enrichment analysis revealed that genes carrying funcMutations were significantly enriched in the MAPK and WNT signaling pathways, and analysis of regulatory modules identified eighteen miRNA modules involved with similar cellular functions. Our findings elucidate a complex relationship between miRNA, mRNA, and mutations, and suggest that 3'UTR mutations may play an important role in tumor development.

Comparative proteome analysis between C . briggsae embryos and larvae reveals a role of chromatin modification proteins in embryonic cell division.

Caenorhabditis briggsae has emerged as a model for comparative biology against model organism C. elegans. Most of its cell fate specifications are completed during embryogenesis whereas its cell growth is achieved mainly in larval stages. The molecular mechanism underlying the drastic developmental changes is poorly understood. To gain insights into the molecular changes between the two stages, we compared the proteomes between the two stages using iTRAQ. We identified a total of 2,791 proteins in the C. briggsae embryos and larvae, 247 of which undergo up- or down-regulation between the two stages. The proteins that are upregulated in the larval stages are enriched in the Gene Ontology categories of energy production, protein translation, and cytoskeleton; whereas those upregulated in the embryonic stage are enriched in the categories of chromatin dynamics and posttranslational modification, suggesting a more active chromatin modification in the embryos than in the larva. Perturbation of a subset of chromatin modifiers followed by cell lineage analysis suggests their roles in controlling cell division pace. Taken together, we demonstrate a general molecular switch from chromatin modification to metabolism during the transition from C. briggsae embryonic to its larval stages using iTRAQ approach. The switch might be conserved across metazoans.

An Integrating Approach for Genome-Wide Screening of MicroRNA Polymorphisms Mediated Drug Response Alterations.

MicroRNAs (miRNAs) are a class of evolutionarily conserved small noncoding RNAs, ~22 nt in length, and found in diverse organisms and play important roles in the regulation of mRNA translation and degradation. It was shown that miRNAs were involved in many key biological processes through regulating the expression of targets. Genetic polymorphisms in miRNA target sites may alter miRNA regulation and therefore result in the alterations of the drug targets. Recent studies have demonstrated that SNPs in miRNA target sites can affect drug efficiency. However, there are still a large number of specific genetic variants related to drug efficiency that are yet to be discovered. We integrated large scale of genetic variations, drug targets, gene interaction networks, biological pathways, and seeds region of miRNA to identify miRNA polymorphisms affecting drug response. In addition, harnessing the abundant high quality biological network/pathways, we evaluated the cascade distribution of tarSNP impacts. We showed that the predictions can uncover most of the known experimentally supported cases as well as provide informative candidates complementary to existing methods/tools. Although there are several existing databases predicting the gain or loss of targeting function of miRNA mediated by SNPs, such as PolymiRTS, miRNASNP, MicroSNiPer, and MirSNP, none of them evaluated the influences of tarSNPs on drug response alterations. We developed a user-friendly online database of this approach named Mir2Drug.

Cyclooxygenase-2 induced ß1-integrin expression in NSCLC and promoted cell invasion via the EP1/MAPK/E2F-1/FoxC2 signal pathway.

Cyclooxygenase-2 (COX-2) has been implicated in cell invasion in non-small-cell lung cancer (NSCLC). However, the mechanism is unclear. The present study investigated the effect of COX-2 on ß1-integrin expression and cell invasion in NSCLC. COX-2 and ß1-integrin were co-expressed in NSCLC tissues. COX-2 overexpression or Prostaglandin E2 (PGE2) treatment increased ß1-integrin expression in NSCLC cell lines. ß1-integrin silencing suppressed COX-2-mediated tumour growth and cancer cell invasion in vivo and in vitro. Prostaglandin E Receptor EP1 transfection or treatment with EP1 agonist mimicked the effect of PGE2 treatment. EP1 siRNA blocked PGE2-mediated ß1-integrin expression. EP1 agonist treatment promoted Erk1/2, p38 phosphorylation and E2F-1 expression. MEK1/2 and p38 inhibitors suppressed EP1-mediated ß1-integrin expression. E2F-1 silencing suppressed EP1-mediated FoxC2 and ß1-integrin upregulation. ChIP and Luciferase Reporter assays identified that EP1 agonist treatment induced E2F-1 binding to FoxC2 promotor directly and improved FoxC2 transcription. FoxC2 siRNA suppressed ß1-integrin expression and EP1-mediated cell invasion. Immunohistochemistry showed E2F-1, FoxC2, and EP1R were all highly expressed in the NSCLC cases. This study suggested that COX-2 upregulates ß1-integrin expression and cell invasion in NSCLC by activating the MAPK/E2F-1 signalling pathway. Targeting the COX-2/EP1/PKC/MAPK/E2F-1/FoxC2/ß1-integrin pathway might represent a new therapeutic strategy for the prevention and treatment of this cancer.

Integrated transcriptional profiling and genomic analyses reveal RPN2 and HMGB1 as promising biomarkers in colorectal cancer.

Colorectal cancer (CRC) is a heterogeneous disease that is associated with a gradual accumulation of genetic and epigenetic alterations. Among all CRC stages, stage II tumors are highly heterogeneous with a high relapse rate in about 20-25 % of stage II CRC patients following surgery. Thus, a comprehensive analysis of gene signatures to identify aggressive and metastatic phenotypes in stage II CRC is desired for a more accurate disease classification and outcome prediction. By utilizing a Cancer Array, containing 440 oncogenes and tumor suppressors to profile mRNA expression, we identified a larger number of differentially expressed genes in poorly differentiated stage II colorectal adenocarcinoma tissues, compared to their matched normal tissues. Ontology and Ingenuity Pathway Analysis (IPA) indicated that these genes are involved in functional mechanisms associated with several transcription factors. Genomic alterations of these genes were also investigated through The Cancer Genome Atlas (TCGA) database, utilizing 195 published CRC specimens. The percentage of genomic alterations in these genes was ranked based on their mRNA expression, copy number variations and mutations. This data was further combined with published microarray studies from a large set of CRC tumors classified based on prognostic features. This led to the identification of eight candidate genes including RPN2, HMGB1, AARS, IGFBP3, STAT1, HYOU1, NQO1 and PEA15 that were associated with the progressive phenotype. In particular, RPN2 and HMGB1 displayed a higher genomic alteration frequency in CRC, compared to eight other major solid cancers. Immunohistochemistry was performed on additional 78 stage I-IV CRC samples, where RPN2 protein immunostaining exhibited a significant association with stage III/IV tumors, distant metastasis, and poor differentiation, indicating that RPN2 expression is associated with poor prognosis. Further, our study revealed significant transcriptional regulatory mechanisms, networks and gene signatures, underlying CRC malignant progression and phenotype warranting future clinical investigations.

Systems-level quantification of division timing reveals a common genetic architecture controlling asynchrony and fate asymmetry.

Coordination of cell division timing is crucial for proper cell fate specification and tissue growth. However, the differential regulation of cell division timing across or within cell types during metazoan development remains poorly understood. To elucidate the systems-level genetic architecture coordinating division timing, we performed a high-content screening for genes whose depletion produced a significant reduction in the asynchrony of division between sister cells (ADS) compared to that of wild-type during Caenorhabditis elegans embryogenesis. We quantified division timing using 3D time-lapse imaging followed by computer-aided lineage analysis. A total of 822 genes were selected for perturbation based on their conservation and known roles in development. Surprisingly, we find that cell fate determinants are not only essential for establishing fate asymmetry, but also are imperative for setting the ADS regardless of cellular context, indicating a common genetic architecture used by both cellular processes. The fate determinants demonstrate either coupled or separate regulation between the two processes. The temporal coordination appears to facilitate cell migration during fate specification or tissue growth. Our quantitative dataset with cellular resolution provides a resource for future analyses of the genetic control of spatial and temporal coordination during metazoan development.

A Genome-wide hybrid incompatibility landscape between Caenorhabditis briggsae and C. nigoni.

Systematic characterization of hybrid incompatibility (HI) between related species remains the key to understanding speciation. The genetic basis of HI has been intensively studied in Drosophila species, but remains largely unknown in other species, including nematodes, which is mainly due to the lack of a sister species with which C. elegans can mate and produce viable progeny. The recent discovery of a C. briggsae sister species, C. nigoni, has opened up the possibility of dissecting the genetic basis of HI in nematode species. However, the paucity of dominant and visible marker prevents the efficient mapping of HI loci between the two species. To elucidate the genetic basis of speciation in nematode species, we first generated 96 chromosomally integrated GFP markers in the C. briggsae genome and mapped them into the defined locations by PCR and Next-Generation Sequencing (NGS). Aided by the marker, we backcrossed the GFP-associated C. briggsae genomic fragments into C. nigoni for at least 15 generations and produced 111 independent introgressions. The introgression fragments cover most of the C. briggsae genome. We finally dissected the patterns of HI by scoring the embryonic lethality, larval arrest, sex ratio and male sterility for each introgression line, through which we identified pervasive HI loci and produced a genome-wide landscape of HI between the two nematode species, the first of its type for any non-Drosophila species. The HI data not only provided insights into the genetic basis of speciation, but also established a framework for the possible cloning of HI loci between the two nematode species. Furthermore, the data on hybrids confirmed Haldane's rule and suggested the presence of a large X effect in terms of fertility between the two species. Importantly, this work opens a new avenue for studying speciation genetics between nematode species and allows parallel comparison of the HI with that in Drosophila and other species.

[Target-resequencing to identify microRNA-associated SNP and predict the effect of SNP on microRNA function in colorectal cancer patients].

OBJECTIVE: To identify SNPs in the miRNA genes in colorectal cancer (CRC) patients and to investigate their association with CRC. METHODS: DNAs were isolated from 30 CRC tumor tissues and 30 tumor-adjacent tissues, and subjected to target capture using a custom miRNA chip covering 685 miRNA genes from NimbleGen. The captured DNAs were then sequenced using the Illumina's sequencing technology, and the data were analyzed. RESULTS: We identified 64 SNPs in 43 miRNA genes and most of these SNPs are novel SNPs not reported previously. Prediction of functional consequences of the SNPs using TargetScan and miRSNP showed that SNPs of hsa-mir-1273-G/A, hsa-mir-548h-3-C/U, hsa-mir-1290-A/G, and hsa-mir-1273-C/U resulted in reduction of their mature miRNA abundance. SNPs of hsa-mir-376b-C/G, hsa-mir-604-T/C, hsa-mir-1268-T/G and hsa-mir-146a-C/G resulted in changes in their targeted genes. Finally, we focused on the analysis of SNPs in mir-146a and we found that mir-146a rs1052918 C>G was predicted to promote tumorigenesis via the Wnt signaling pathway. CONCLUSIONS: SNPs in the miRNA genes are important for tumorigenesis. The changes by hsa-mir-146a rs1052918 C>G may result in loss of Wnt, constant activation of the Wnt signaling pathway, and uncontrolled cell proliferation and tumor progression.

Analysis of different strategies adapted by two cassava cultivars in response to drought stress: ensuring survival or continuing growth.

Cassava is one of the most drought-tolerant crops, however, the underlying mechanism for its ability to survive and produce under drought remains obscure. In this study, two cassava cultivars, SC124 and Arg7, were treated by gradually reducing the soil water content. Their responses to the drought stress were examined through their morphological and physiological traits and isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analysis. SC124 plants adapted a 'survival' mode under mild drought stress as evidenced by early stomatal closure and a reduction in the levels of various photosynthetic proteins and photosynthetic capacity, resulting in early growth quiescence. In contrast, Arg7 plants underwent senescence of older leaves but continued to grow, although at a reduced rate, under mild drought. SC124 plants were more capable of surviving prolonged severe drought than Arg7. The iTRAQ analysis identified over 5000 cassava proteins. Among the drought-responsive proteins identified in the study were an aquaporin, myo-inositol 1-phosphate synthases, and a number of proteins involved in the antioxidant systems and secondary metabolism. Many proteins that might play a role in signalling or gene regulation were also identified as drought-responsive proteins, which included several protein kinases, two 14-3-3 proteins, several RNA-binding proteins and transcription factors, and two histone deacetylases. Our study also supports the notion that linamarin might play a role in nitrogen reallocation in cassava under drought.