Key Pathway Genes Research Articles

Abstract IA011: mTOR pathway gene expression in association with race and clinicopathological characteristics in Black and White breast cancer patients

Abstract Background Aberrant activation of the mammalian Target of Rapamycin (mTOR) pathway has been linked to obesity and endocrine therapy resistance, factors that may contribute to Black White disparities in breast cancer outcomes. We evaluated associations of race and clinicopathological characteristics with mRNA expression of key mTOR pathway genes in breast tumors. Methods Surgical tumor tissue blocks were collected from 367 newly diagnosed breast cancer patients (190 Black and 177 White). Gene expression of AKT1, EIF4EBP1, MTOR, RPS6KB2, and TSC1 were quantified by NanoString nCounter. Differential gene expression was assessed using linear regression on log2-transformed values. Gene expression and DNA methylation data from TCGA were used for validation and investigation of race-related differences. Results Compared to White women, Black women had relative under-expression of AKT1 (log2 fold-change = - 0.31, 95% CI - 0.44, - 0.18) and RPS6KB2 (log2 fold-change = - 0.11, 95% CI - 0.19, - 0.03). Higher vs. lower tumor grade was associated with relative over-expression of EIF4EBP1 and RPS6KB2, but with lower expression of TSC1. Compared to luminal tumors, triple-negative tumors had relative under-expression of TSC1 (log2 fold-change = - 0.42, 95% CI - 0.22, - 0.01). The results were similar in the TCGA breast cancer dataset. Post-hoc analyses identified differential CpG methylation within the AKT1 and RPS6KB2 locus between Black and White women. Conclusions Over-expression of RPS6KB2 and EIF4EBP1 and under-expression of TSC1 might be indicators of more aggressive breast cancer phenotypes. Differential expression of AKT1 and RPS6KB2 by race warrants further investigation to elucidate their roles in racial disparities of treatment resistance and outcomes between Black and White women with breast cancer. Citation Format: Mmadili N. Ilozumba, Song Yao, Adana A. M. Llanos, Angela R. Omilian, Weizhou Zhang, Susmita Datta, Chi Chen Hong, Warren Davis, Thaer Khoury, Elisa V. Bandera, Michael Higgins, Christine B. Ambrosone, Ting Yuan David Cheng. mTOR pathway gene expression in association with race and clinicopathological characteristics in Black and White breast cancer patients [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr IA011.

Exogenous melatonin treatment affects ascorbic acid metabolism in postharvest 'Jinyan' kiwifruit.

Ascorbic acid (AsA) is an important nutritious substance in fruits, and it also can maintain the biological activity of fruits during storage. This research investigated the effect of exogenous melatonin (MT) on AsA metabolism in postharvest kiwifruit. Our results indicated that exogenous MT delayed the decrease of fruit firmness and titratable acid (TA), inhibited the increase of soluble solids content (SSC), reduced the respiration rate and ethylene production, and maintained a higher AsA content in kiwifruit during storage. The high expression of L-galactose pathway key genes in the early storage and regeneration genes in the later storage maintained the AsA content in postharvest kiwifruit. MT treatment enhanced the expression levels of AsA biosynthesis (AcGME2, AcGalDH, and AcGalLDH) and regeneration (AcGR, AcDHAR, and AcMDHAR1) genes. Meanwhile, the expression of the degradation gene AcAO was inhibited in MT-treated kiwifruits.

Insufficient or excessive dietary carbohydrates affect gut health through change in gut microbiota and regulation of gene expression of gut epithelial cells in grass carp (Ctenopharyngodon idella)

Dietary carbohydrate levels can affect gut health, but the roles played by gut microbiota and gut epithelial cells, and their interactions remain unclear. In this experiment, we investigated gut health, gut microbiota, and the gene expression profiles of gut epithelial cells in grass carp consuming diets with different carbohydrate levels. Compared to the moderate-carbohydrate diet, low-carbohydrate diet significantly increased the relative abundance of pathogenic bacteria (Ralstonia and Elizabethkingia) and decreased the abundance of metabolism in cofactors and vitamins, implying a dysregulated gut microbiota and compromised metabolic function. Moreover, low-carbohydrate diet inhibited the expression levels of key genes in autophagy-related pathways in gut epithelial cells, which might directly lead to reduced clearance of defective organelles and pathogenic microorganisms. These aforementioned factors may be responsible for the imperfect organization of the intestinal tract. High-carbohydrate diet also significantly increased the abundance of pathogenic bacteria (Flavobacterium), which directly contributed to a decrease in the abundance of immune system of the microbiota. Furthermore, the active pathways of staphylococcus aureus infection and complement and coagulation cascades, as well as the inhibition of the glutathione metabolism pathway were observed. Above results implied that high-carbohydrate diet might ultimately cause severe gut damage by affecting immune function of microbiota, mentioned immune-related pathways, and the antioxidant capacity. Finally, the correlation network diagram revealed strong correlations of the differentially immune-related gene major histocompatibility complex class I antigen (MR1) with Enhydrobacter and Ruminococcus_gnavus_group in low-carbohydrate diet group, and Arenimonas in high-carbohydrate diet group, respectively, suggesting that MR1 might be a central target for immune responses in gut epithelial cells induced by gut microbiota at different levels of dietary carbohydrate. All these results provided insight in the development of antagonistic probiotics and target genes to improve the utilization of carbohydrate.

From Plant to Yeast-Advances in Biosynthesis of Artemisinin.

Malaria is a life-threatening disease. Artemisinin-based combination therapy (ACT) is the preferred choice for malaria treatment recommended by the World Health Organization. At present, the main source of artemisinin is extracted from Artemisia annua; however, the artemisinin content in A. annua is only 0.1–1%, which cannot meet global demand. Meanwhile, the chemical synthesis of artemisinin has disadvantages such as complicated steps, high cost and low yield. Therefore, the application of the synthetic biology approach to produce artemisinin in vivo has magnificent prospects. In this review, the biosynthesis pathway of artemisinin was summarized. Then we discussed the advances in the heterologous biosynthesis of artemisinin using microorganisms (Escherichia coli and Saccharomyces cerevisiae) as chassis cells. With yeast as the cell factory, the production of artemisinin was transferred from plant to yeast. Through the optimization of the fermentation process, the yield of artemisinic acid reached 25 g/L, thereby producing the semi-synthesis of artemisinin. Moreover, we reviewed the genetic engineering in A. annua to improve the artemisinin content, which included overexpressing artemisinin biosynthesis pathway genes, blocking key genes in competitive pathways, and regulating the expression of transcription factors related to artemisinin biosynthesis. Finally, the research progress of artemisinin production in other plants (Nicotiana, Physcomitrella, etc.) was discussed. The current advances in artemisinin biosynthesis may help lay the foundation for the remarkable up-regulation of artemisinin production in A. annua through gene editing or molecular design breeding in the future.

NXPH4 Used as a New Prognostic and Immunotherapeutic Marker for Muscle-Invasive Bladder Cancer.

Background One of the most common malignant tumors of the urinary system is muscle-invasive bladder cancer (MIBC). With the increased use of immunotherapy, its importance in the field of cancer is becoming abundantly evident. This study classifies MIBC according to GSVA score from the perspective of the GSEA immune gene set. Methods This study integrated the sequencing and clinical data of MIBC patients in TCGA and GEO databases, then scored the data using the GSVA algorithm, the CNMF algorithm was implemented to divide the subtypes of GEO and TCGA datasets, respectively, and finally screened and determined the key pathways in combination with clinical data. Simultaneously, LASSO Cox regression model was constructed based on key pathway genes to assess the model's predictive ability (ROC) and describe the immune landscape differences between high- and low-risk groups; key genes were further analyzed and verified in patient tissues. Results 404 TCGA and 297 GEO datasets were divided into C1-3 groups (TCGA-C1:120/C2:152/C3:132; GEO- C1:112/C2:101/C3:84), of which TCGA-C2 (n = 152) subtype and GEO-C1 (n = 112) subtype had the worst prognosis. LASSO Cox regression model with ROC (train set = 0.718, test set = 0.667) could be constructed. When combined with the Cancer Immunome Atlas database, it was found that patients with high-risk scores were more sensitive to PD-1 inhibitor and PD-1 inhibitor combined with CTLA-4. NXPH4, as a key gene, plays a role in MIBC with tissue validation results show that nxph4 is highly expressed in tumor. Conclusion The immune gene score of MIBC data in TCGA and GEO databases was successfully evaluated using GSVA in this research. The lasso Cox expression model was successfully constructed by screening immune genes, the high-risk group had a worse prognosis and higher sensitivity to immunotherapy, PD-1 inhibitors or PD-1 combined with CTLA-4 inhibitors can be preferentially used in high-risk patients who are sensitive to immunotherapy, and NXPH4 may be a molecular target to adjust the effect of immunotherapy.

Identification of key genes through the constructed CRISPR-dcas9 to facilitate the efficient production of O-acetylhomoserine in Corynebacterium glutamicum.

O-Acetylhomoserine (OAH) is an important platform chemical for the synthesis of L-methamidophos and l-methionine. It has been produced efficiently in Corynebacterium glutamicum. However, a wider range of key factors had not been identified, limiting further increases in OAH production. This study successfully identified some limiting factors and regulated them to improve OAH titer. Firstly, an efficient clustered regularly interspaced short palindromic repeats/dead CRISPR associated protein 9 (CRISPR-dCas9) system was constructed and used to identify the key genes in central metabolism and branch pathways associated with OAH biosynthesis. Then, the gltA gene involved in TCA cycle was identified as the most critical gene. A sequential promoter PNCgl2698, which showed different transcriptional intensity in different strain growth periods, was used to control the expression of gltA gene, resulting in OAH production of 7.0 g/L at 48 h. Finally, the OAH titer of the engineered strain reached 25.9 g/L at 72 h in a 5-L bioreactor. These results show that the identification and regulation of key genes are critical for OAH biosynthesis, which would provide a better research basis for the industrial production of OAH in C. glutamicum.

Stemness analysis in hepatocellular carcinoma identifies an extracellular matrix gene-related signature associated with prognosis and therapy response.

Background: Tumor stemness is the stem-like phenotype of cancer cells, as a hallmark for multiple processes in the development of hepatocellular carcinoma (HCC). However, comprehensive functions of the regulators of tumor cell’s stemness in HCC remain unclear. Methods: Gene expression data and clinical information of HCC samples were downloaded from The Cancer Genome Atlas (TCGA) dataset as the training set, and three validation datasets were derived from Gene Expression Omnibus (GEO) and International Cancer Genome Consortium (ICGC). Patients were dichotomized according to median mRNA expression–based stemness index (mRNAsi) scores, and differentially expressed genes were further screened out. Functional enrichment analysis of these DEGs was performed to identify candidate extracellular matrix (ECM)–related genes in key pathways. A prognostic signature was constructed by applying least absolute shrinkage and selection operator (LASSO) to the candidate ECM genes. The Kaplan–Meier curve and receiver operating characteristic (ROC) curve were used to evaluate the prognostic value of the signature. Correlations between signatures and genomic profiles, tumor immune microenvironment, and treatment response were also explored using multiple bioinformatic methods. Results: A prognostic prediction signature was established based on 10 ECM genes, including TRAPPC4, RSU1, ILK, LAMA1, LAMB1, FLNC, ITGAV, AGRN, ARHGEF6, and LIMS2, which could effectively distinguish patients with different outcomes in the training and validation sets, showing a good prognostic prediction ability. Across different clinicopathological parameter stratifications, the ECMs signature still retains its robust efficacy in discriminating patient with different outcomes. Based on the risk score, vascular invasion, α-fetoprotein (AFP), T stage, and N stage, we further constructed a nomogram (C-index = 0.70; AUCs at 1-, 3-, and 5-year survival = 0.71, 0.75, and 0.78), which is more practical for clinical prognostic risk stratification. The infiltration abundance of macrophages M0, mast cells, and Treg cells was significantly higher in the high-risk group, which also had upregulated levels of immune checkpoints PD-1 and CTLA-4. More importantly, the ECMs signature was able to distinguish patients with superior responses to immunotherapy, transarterial chemoembolization, and sorafenib. Conclusion: In this study, we constructed an ECM signature, which is an independent prognostic biomarker for HCC patients and has a potential guiding role in treatment selection.

Upregulation of PARG in prostate cancer cells suppresses their malignant behavior and downregulates tumor-promoting genes

Post-translational modification of nuclear proteins through the addition of poly(ADP-ribose) (pADPr) moieties is upregulated in many metastatic cancers, where the high levels of pADPr have often been associated with poor cancer prognosis. Although the inhibitors of poly(ADP-ribose) polymerases (PARPs) have been utilized as potent anti-cancer agents, their efficacy in clinical trials varied among patient groups and has often been unpredictable. Such outcome cannot be interpreted solely by the inability to keep PARP-driven DNA repair in check. The focus of studies on PARP-driven tumorigenesis have recently been shifted toward PARP-dependent regulation of transcription. Here we utilized the controlled overexpression of poly(ADP-ribose) glycohydrolase (PARG), a sole pADPr-degrading enzyme, to investigate pADPr-dependent gene regulation in prostate cancer PC-3 cells. We demonstrated that PARG upregulation reduces pADPr levels and inhibits the expression of genes in key tumor-promoted pathways, including TNFα/NF-kB, IL6/STAT3, MYC, and KRAS signaling, the genes involved in inflammation response, especially chemokines, and endothelial-mesenchymal transition. The observed effect of PARG on transcription was consistent across all tested prostate cancer cell lines and correlates with PARG-induced reduction of clonogenic potential of PC-3 cells in vitro and a significant growth inhibition of PC-3-derived tumors in nude mice in vivo.

Alteration of the Nucleotide Excision Repair (NER) Pathway in Soft Tissue Sarcoma.

Clinical responses to anticancer therapies in advanced soft tissue sarcoma (STS) are unluckily restricted to a small subgroup of patients. Much of the inter-individual variability in treatment efficacy is as result of polymorphisms in genes encoding proteins involved in drug pharmacokinetics and pharmacodynamics. The nucleotide excision repair (NER) system is the main defense mechanism for repairing DNA damage caused by carcinogens and chemotherapy drugs. Single nucleotide polymorphisms (SNPs) of NER pathway key genes, altering mRNA expression or protein activity, can be significantly associated with response to chemotherapy, toxicities, tumor relapse or risk of developing cancer. In the present study, in a cohort of STS patients, we performed DNA extraction and genotyping by SNP assay, RNA extraction and quantitative real-time reverse transcription PCR (qPCR), a molecular dynamics simulation in order to characterize the NER pathway in STS. We observed a severe deregulation of the NER pathway and we describe for the first time the effect of SNP rs1047768 in the ERCC5 structure, suggesting a role in modulating single-stranded DNA (ssDNA) binding. Our results evidenced, for the first time, the correlation between a specific genotype profile of ERCC genes and proficiency of the NER pathway in STS.

A Survey of the Metabolic Landscape of the Developing Cerebellum at Single-Cell Resolution

The use of cell-culture models to investigate development and disease of the cerebellum is a recent advance, facilitated by the discovery that patterning of precursors is capable of giving rise to cells with specific neuronal identity. Pluripotent stem cell-derived organoids, which exhibit self-organisational characteristics reminiscent of early cerebellar tissue, present a number of challenges including recapitulation of conditions resembling the mature brain. An understanding of the processes driving fetal and postnatal maturation is required to reproduce these conditions in vitro and advance the capability of the system to model adult-onset disease. A key tool for achieving this is single-cell RNA sequencing, which enables visualisation of key transcriptional features of subpopulations comprising tissues. Here, we explore and compare available single-cell RNA sequencing data derived from the developing human cerebellum and its synthetic, in vitro counterpart (stem cell-derived cerebellar organoids). We focus on performing a qualitative assessment of the expression of key metabolic pathway genes, given recent findings exemplifying tissue-specific metabolic activity, including hypoxia and metabolic shifts associated with neuronal expansion. Signatures indicative of known cell type-specific metabolic differences, such as the astrocyte-neuron lactate shuttle and glutamate-glutamine cycle were evident at a transcriptional level. Cerebellar tissue and cerebellar organoids showed a number of behavioural similarities, including HIF1 signalling, which may serve to drive expansion of granule cell progenitors in both settings. We further highlight numerous differences between cultured organoids and native tissue which may provide clarity on the state of metabolic state following differentiation of organoids, providing the future framework to test and further hypotheses regarding promoting maturation. Overall, this analysis provides insight into understanding the state of in vitro models of the cerebellum, a critical factor required for modelling susceptibility of various cell types to cerebellar disease.

A composite arctigenin/caffeine/glucose formulation enhances anti-fatigue effect

Fatigue is a comprehensive response to a variety of physiological and biochemical changes in the body. Combining strategies addressing relevant key factors simultaneously may enhance anti-fatigue efficiency. In this study, we aimed to develop new anti-fatigue agents with combining strategy based on bioinformatics analysis. Result indicated PI3k-Akt, cAMP, and p53 signaling pathway-related energy metabolism and antioxidant capacity were involved in exercise-induced physiological changes. A new representative complex agent (Z-005, containing arctigenin, caffeine, and glucose) addressing these key factors as well as central excitation was developed and tested. Z-005 showed a synergistic effect, greatly enhancing anti-fatigue efficiency than single components, in a mouse running wheel test. Mouse exhaustion distances were 2.40-fold greater than the control in the Z-005 group. Z-005 excited the central nervous system, increased the plasma superoxide dismutase and catalase concentrations, reduced lactic acid accumulation, maintained the glycogen content. Besides, the expression of key genes in PI3K, cAMP, and p53 pathways, as well as the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) were proved with enhancement by Z-005 administration. This composite formulation thus represents a new and practicable combined strategy for fatigue prevention, and the study findings can contribute to the development of treatments for fatigue-related sub-health.

BnKAT2 Positively Regulates the Main Inflorescence Length and Silique Number in Brassica napus by Regulating the Auxin and Cytokinin Signaling Pathways.

Brassica napus is the dominant oil crop cultivated in China for its high quality and high yield. The length of the main inflorescence and the number of siliques produced are important traits contributing to rapeseed yield. Therefore, studying genes related to main inflorescence and silique number is beneficial to increase rapeseed yield. Herein, we focused on the effects of BnKAT2 on the main inflorescence length and silique number in B. napus. We explored the mechanism of BnKAT2 increasing the effective length of main inflorescence and the number of siliques through bioinformatics analysis, transgenic technology, and transcriptome sequencing analysis. The full BnKAT2(BnaA01g09060D) sequence is 3674 bp, while its open reading frame is 2055 bp, and the encoded protein comprises 684 amino acids. BnKAT2 is predicted to possess two structural domains, namely KHA and CNMP-binding domains. The overexpression of BnKAT2 effectively increased the length of the main inflorescence and the number of siliques in B. napus, as well as in transgenic Arabidopsis thaliana. The type-A Arabidopsis response regulator (A-ARR), negative regulators of the cytokinin, are downregulated in the BnKAT2-overexpressing lines. The Aux/IAA, key genes in auxin signaling pathways, are downregulated in the BnKAT2-overexpressing lines. These results indicate that BnKAT2 might regulate the effective length of the main inflorescence and the number of siliques through the auxin and cytokinin signaling pathways. Our study provides a new potential function gene responsible for improvement of main inflorescence length and silique number, as well as a candidate gene for developing markers used in MAS (marker-assisted selection) breeding to improve rapeseed yield.

Establishing Komagataella phaffii as a Cell Factory for Efficient Production of Sesquiterpenoid α-Santalene.

Santalene, a major component of the sandalwood essential oil, is a typical representative of sesquiterpenes and has important applications in medicine, food, flavors, and other fields. Due to the limited supply of natural sandalwood resources, there is a growing interest in engineering microbial cell factories for the mass production of santalene. In the present study, Komagataella phaffii (also known as Pichia pastoris) was established as a cell factory for high-level production of α-santalene for the first time. The metabolic fluxes were rewired toward α-santalene biosynthesis through the optimization of promoters to drive the expression of the α-santalene synthase (SAS) gene, overexpression of the key mevalonate pathway genes (i.e., tHMG1, IDI1, and ERG20), and multi-copy integration of the SAS expression cassette. In combination with medium optimization and bioprocess engineering, the optimal strain (STE-9) was able to produce α-santalene with a titer as high as 829.8 ± 70.6 mg/L, 4.4 ± 0.3 g/L, and 21.5 ± 1.6 g/L in a shake flask, batch fermenter, and fed-batch fermenter, respectively. These represented the highest production of α-santalene ever reported, highlighting the advantages of K. phaffii cell factories for the production of terpenoids and other natural products.

Metabolomic and Transcriptomic Analyses of Quality Deterioration in Fusarium solani-Infected Sweet Potato (Ipomoea batatas (L.) Lam cv Xinxiang) Storage Roots.

Fusarium solani-induced quality deterioration in stored sweet potato is poorly characterized and understood. This study examined the effects of F. solani infection in Xinxiang sweet potato roots during storage. The results showed that while there were no external symptoms following F. solani infection, upon cutting the roots, the cut surface of the infected root rapidly turned black, whereas the untreated control roots remained unaffected. The metabolites and transcriptive differences between F. solani-infected and control sweet potato roots were investigated with high-performance liquid chromatography, metabolomic analysis, and an Illumina Novaseq platform. The results showed that levels of the toxic ipomeamarone accumulated as high as 2.36 mg/kg DW in tissue after F. solani inoculation and 6 days storage at 28 °C, where the control tissue sample did not accumulate any ipomeamarone. Metabolomic analysis showed that isochlorogenic acid and l-tyrosine significantly increased in the infected tissue and associated with the darkening cut surface of the infected sweet potato. In transcriptomic analysis, a total of 13, 14, and 6 key genes in ipomeamarone, isochlorogenic acid, and l-tyrosine biosynthesis pathways, respectively, were identified. A conceptual model elucidating the physiological and molecular mechanism of F. solani-induced quality deterioration in sweet potato is proposed.

Morphological and Molecular Analyses of the Interaction between Rosa multiflora and Podosphaera pannosa.

Powdery mildew disease caused by Podosphaera pannosa is the most widespread disease in global cut-rose production, as well as a major disease in garden and pot roses. In this study, the powdery mildew resistance of different wild rose varieties was evaluated. Rose varieties with high resistance and high sensitivity were used for cytological observation and transcriptome and expression profile analyses to study changes at the morphological and molecular levels during the interaction between Rosa multiflora and P. pannosa. There were significant differences in powdery mildew resistance among three R. multiflora plants; R. multiflora ‘13’ had high resistance, while R. multiflora ‘4’ and ‘1’ had high susceptibility. Cytological observations showed that in susceptible plants, 96 and 144 h after inoculation, hyphae were observed in infected leaves; hyphae infected the leaf tissue through the stoma of the lower epidermis, while papillae were formed on the upper epidermis of susceptible leaf tissue. Gene ontology enrichment analysis showed that the differentially expressed genes that were significantly enriched in biological process functions were related to the secondary metabolic process, the most significantly enriched cellular component function was cell wall, and the most significantly enriched molecular function was chitin binding. Changes in the transcript levels of important defense-related genes were analyzed. The results showed that chitinase may have played an important role in the interactions between resistant R. multiflora and P. pannosa. Jasmonic acid and ethylene (JA/ET) signaling pathways might be triggered in the interaction between susceptible R. multiflora and P. pannosa. In the resistant R. multiflora, the salicylic acid (SA) signaling pathway was induced earlier. Between susceptible plants and resistant plants, key phenylpropanoid pathway genes were induced and upregulated after P. pannosa inoculation, demonstrating that the phenylpropanoid pathway and secondary metabolites may play important and active roles in R. multiflora defense against powdery mildew infection.

Biocontrol yeast T-2 improves the postharvest disease resistance of grape by stimulation of the antioxidant system.

Table grapes are susceptible to external pathogens during postharvest storage. The resulting continuous oxidative stress causes damage and aging, thereby reducing the defense against disease. In this study, the effect of biocontrol yeast T‐2 on the storage performance of grapes was evaluated. After T‐2 treatment, the grapefruits rot rate and lesion diameter caused by Botrytis cinerea (B. cinerea) were significantly decreased at 2–5 days after inoculation (DAI). Additionally, the browning rate and shedding rate of grapefruit during storage were significantly reduced at 2–5 DAI, and the weight loss rate was significantly reduced at 3–5 DAI. The decreased malondialdehyde (MDA) content in grapefruits at 1–5 DAI with T‐2 indicated a reduction in oxidative damage. Furthermore, the activities of antioxidant enzymes such as peroxidase (POD), catalase (CAT), phenylalanin ammonia‐lyase (PAL) were significantly increased during most storage time after being treated with T‐2. Moreover, the contents of total phenolics and flavonoids and the expression levels of key enzyme genes in metabolic pathways were increased after T‐2 treatment during most postharvest storage time, providing evidence that T‐2 changed the biological process of phenolic flavonoid metabolism. The increase in enzymatic and nonenzymatic antioxidants after treatment with T‐2 reflected the strengthening of the antioxidant system, hence postponing fruit senescence and promoting storage performance under the stress of B. cinerea.

Transcriptomic and Metabolic Profiling of Kenaf Stems under Salinity Stress.

Kenaf (Hibiscus cannabinus L.) is an indispensable fiber crop that faces increasing salinity stress. In previous studies regarding the molecular mechanisms of how kenaf may respond to salt stress, no metabolic evidences have been reported. Meanwhile, studies regarding kenaf stems under adverse growth conditions have not been conducted. In the present study, multiple-layer evidences including physiological, transcriptomic, and metabolic data regarding how kenaf stems were affected by the salt stress are provided, wherein the stem growth, especially the lignification process, is retarded. Meanwhile, the transcriptomic data indicated genes involved in the photosynthesis are significantly repressed while the multiple flavonoid metabolism genes are enriched. As to the metabolic data, the content variation for the growth-promotion phytohormones such as IAA and the stress-responding ones including ABA are within or without expectations, implying these phytohormones played complicated roles when the kenaf stems encounter salt stress. However, the metabolite variations did not always agree with the expression levels of corresponding key pathway genes, possibly because the metabolite could be biosynthesized or catabolized in multiple pathways. Collectively, our data may enlighten, more specifically, downstream studies on kenaf responses against salinity and other adverse conditions.

Carbon supply and water status regulate fatty acid and triacylglycerol biosynthesis at transcriptional level in the olive mesocarp.

The relative contribution of carbon sources generated from leaves and fruits photosynthesis for triacylglycerol biosynthesis in the olive mesocarp and their interaction with water stress was investigated. With this aim, altered carbon source treatments were combined with different irrigation conditions. A higher decrease in mesocarp oil content was observed in fruits under girdled and defoliated shoot treatment compared to darkened fruit conditions, indicating that both leaf and fruit photosynthesis participate in carbon supply for oil biosynthesis being leaves the main source. The carbon supply and water status affected oil synthesis in the mesocarp, regulating the expression of DGAT and PDAT genes and implicating DGAT1‐1, DGAT2, PDAT1‐1, and PDAT1‐2 as the principal genes responsible for triacylglycerol biosynthesis. A major role was indicated for DGAT2 and PDAT1‐2 in well‐watered conditions. Moreover, polyunsaturated fatty acid content together with FAD2‐1, FAD2‐2 and FAD7‐1 expression levels were augmented in response to modified carbon supply in the olive mesocarp. Furthermore, water stress caused an increase in DGAT1‐1, DGAT1‐2, PDAT1‐1, and FAD2‐5 gene transcript levels. Overall, these data indicate that oil content and fatty acid composition in olive fruit mesocarp are regulated by carbon supply and water status, affecting the transcription of key genes in both metabolic pathways.

MTOR pathway gene expression in association with race and clinicopathological characteristics in Black and White breast cancer patients

BackgroundAberrant activation of the mammalian Target of Rapamycin (mTOR) pathway has been linked to obesity and endocrine therapy resistance, factors that may contribute to Black-White disparities in breast cancer outcomes. We evaluated associations of race and clinicopathological characteristics with mRNA expression of key mTOR pathway genes in breast tumors.MethodsSurgical tumor tissue blocks were collected from 367 newly diagnosed breast cancer patients (190 Black and 177 White). Gene expression of AKT1, EIF4EBP1, MTOR, RPS6KB2, and TSC1 were quantified by NanoString nCounter. Differential gene expression was assessed using linear regression on log2-transformed values. Gene expression and DNA methylation data from TCGA were used for validation and investigation of race-related differences.ResultsCompared to White women, Black women had relative under-expression of AKT1 (log2 fold-change = − 0.31, 95% CI − 0.44, − 0.18) and RPS6KB2 (log2 fold-change = − 0.11, 95% CI − 0.19, − 0.03). Higher vs. lower tumor grade was associated with relative over-expression of EIF4EBP1 and RPS6KB2, but with lower expression of TSC1. Compared to luminal tumors, triple-negative tumors had relative under-expression of TSC1 (log2 fold-change = − 0.42, 95% CI − 0.22, − 0.01). The results were similar in the TCGA breast cancer dataset. Post-hoc analyses identified differential CpG methylation within the AKT1 and RPS6KB2 locus between Black and White women.ConclusionsOver-expression of RPS6KB2 and EIF4EBP1 and under-expression of TSC1 might be indicators of more aggressive breast cancer phenotypes. Differential expression of AKT1 and RPS6KB2 by race warrants further investigation to elucidate their roles in racial disparities of treatment resistance and outcomes between Black and White women with breast cancer.

The effect of nutritional status on the synthesis ability, protein content and gene expression of mandibular glands in honey bee (Apis mellifera) workers

The mandibular glands (MGs) of honey bee workers are key exocrine glands responsible for the biosynthesis of multiple royal jelly acids, which have important functions within the colony. However, our knowledge about the nutrition requirement of MGs is quite limited. Here, we artificially manipulated the nutritional status of caged honey bee workers (pollen and sugar candy, sugar candy only, soybean meal and sugar candy, stearic acid supplemented sugar candy or citric acid supplemented sugar candy). Then we measured their impact on the 10-hydroxy-2-decanoic acid (10-HDA) and 10-hydroxydecanoic acid (10-HDAA) content in honey bee heads to evaluate the synthesis ability of workers’ MGs, and analyzed the protein content of MGs as well as gene expression in the MGs to reveal the possible physiological changes. Our result showed that nutrition strongly impacted the MGs acid synthesis, the 10-HDA and 10-HDAA contents were significantly higher in workers fed with pollen than with sugar candy only, while an additional supply of protein and organic acid showed no significant contribution. In addition, the 10-HDA/10-HDAA ratio was also significantly affected by the nutrition status. On the contrary, different diets showed no influence on the protein content or gene expressions of MGs, except that organic acid supplements could increase the expression of key genes in fatty acid β-oxidation pathways. Taken together, our study revealed that honey bee nutritional status is closely related to the function of worker MGs. The nutritional deficiency has a significant negative impact on the synthesis ability of worker MGs, but showed no effect on the physiology of MGs.