Elucidation of the 1-phenethylisoquinoline pathway from an endemic conifer Cephalotaxus hainanensis.

Cephalotaxines harbor great medical potential, but their natural source, the endemic conifer Cephalotaxus is highly endangered, creating a conflict between biotechnological valorization and preservation of biodiversity. Here, we construct the whole biosynthetic pathway to the 1-phenethylisoquinoline scaffold, as first committed compound for phenylethylisoquinoline alkaloids (PIAs), combining metabolic modeling, and transcriptome mining of Cephalotaxus hainanensis to infer the biosynthesis for PIA precursor. We identify a novel protein, ChPSS, driving the Pictet-Spengler condensation and show that this enzyme represents the branching point where PIA biosynthesis diverges from the concurrent benzylisoquinoline-alkaloids pathway. We also pinpoint ChDBR as crucial step to form 4-hydroxydihydrocinnamaldehyde diverging from lignin biosynthesis. The elucidation of the early PIA pathway represents an important step toward microbe-based production of these pharmaceutically important alkaloids resolving the conflict between biotechnology and preservation of biodiversity.

The Entropy of van der Waals Fluid.

Thermodynamic state functions are fundamental quantities in many fields. In this work, the van der Waals (vdW) equation of state and calculation formulas of state functions are derived with statistical thermodynamic method in three-dimensional (3D) and two-dimensional (2D) spaces. The heat capacity at constant volume (CV,m ) or area (CA,m ) is exactly the same as that of ideal gas, but the heat capacity at constant pressure (Cp,m ) and other state functions are different from those of ideal gas. The vdW equation of state is a cubic equation, which leads to the fact that the entropy and free energy changes of vdW fluid can be expressed as explicit expressions of volume rather than pressure. Therefore, the adsorbate entropy at constant area can still be theoretically proven to have a linear relationship with the gas-phase entropy at constant volume. However, the linear correlation between it and gas-phase entropy at constant pressure is no longer strictly true in theory. In addition, since the vdW equation of state is applicable to both gas and liquid, the linear correlation between adsorbate entropy and liquid-phase entropy can also be found. At last, the reference state for real gas or fluid at a constant molar volume is suggested.

The transcription factor ATF2 promotes gastric cancer progression by activating the METTL3/cyclin D1 pathway.

Globally, gastric cancer (GC) is a major cause of cancer death. This study is aimed at investigating the biological functions of activating transcription factor 2 (ATF2) and the underlying mechanism in GC. In the present work, GEPIA, UALCAN, Human Protein Atlas and StarBase databases were adopted to analyze ATF2 expression characteristics in GC tissues and normal gastric tissues, and its relationships with tumor grade and patients' survival time. Quantitative real-time polymerase chain reaction (qRT-PCR) method was employed to examine ATF2 mRNA expression in normal gastric tissues, GC tissues, and GC cell lines. Cell counting kit-8 (CCK-8) and EdU assays were utilized for detecting GC cell proliferation. Cell apoptosis was detected by flow cytometry. PROMO database was applied to predict the binding site of ATF2 with the METTL3 promoter region. The binding relationship between ATF2 and the METTL3 promoter region was verified through dual-luciferase reporter gene assay and chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) assay. Western blot was performed to evaluate the effect of ATF2 on METTL3 expression. METTL3-related signaling pathways were predicted using Gene Set Enrichment Analysis (GSEA) in the LinkedOmics database. It was found that, ATF2 level was elevated in GC tissues and cell lines in comparison with normal tissues and correlated with short patients' survival time. ATF2 overexpression facilitated GC cell growth and suppressed the apoptosis, whereas ATF2 knockdown suppressed GC cell proliferation and facilitated the apoptosis. ATF2 bound to the METTL3 promoter region, and ATF2 overexpression promoted the transcription of METTL3, and ATF2 knockdown restrained the transcription of METTL3. METTL3 was associated with cell cycle progression, and ATF2 overexpression enhanced cyclin D1 expression, and METTL3 knockdown reduced cyclin D1 expression. In summary, ATF2 facilitates GC cell proliferation and suppresses the apoptosis via activating the METTL3/cyclin D1 signaling pathway, and ATF2 is promising to be an anti-drug target for GC.

Functional characterization of a Colchicum autumnale L. double-bond reductase (CaDBR1) in colchicine biosynthesis.

MAIN CONCLUSION: An alkenal double-bond reductase enzyme (CaDBR1) was cloned from Colchicum autumnale L. The encoded enzyme catalysed 4-coumaraldehyde to 4-hydroxydihydrocinnamaldehyde (4-HDCA). Its functional characterization increased the understanding of colchicine biosynthesis. As a traditional medical plant, Colchicum autumnale L. is famous for producing colchicine, a widely used drug for alleviating gout attacks. The biosynthetic pathway of colchicine was revealed most recently, and 4-hydroxydihydrocinnamaldehyde (4-HDCA) has been verified as a crucial intermediate derived from L-phenylalanine. However, the functional gene that catalyses the formation of 4-HDCA remains controversial. In this study, the alkenal double-bond reductase (DBR) gene member CaDBR1 was cloned and characterized from C. autumnale. Bioinformatics analysis predicted and characterized the basic physicochemical properties of CaDBR1. Recombinant CaDBR1 protein was heterologously expressed in Escherichia coli and purified by a Ni-NTA column. In vitro enzyme assays indicated that CaDBR1 could catalyse 4-coumaraldehyde to form 4-HDCA but could not generate 4-HDCA by taking cinnamaldehyde as a substrate. Stable transformation into tobacco BY-2 cells revealed that CaDBR1 localized in the cytoplasm, and tissue-specific expression results showed that CaDBR1 had the highest expression in bulbs. All these results verify and confirm the participation and contribution of CaDBR1 in the biosynthesis pathway of 4-HDCA and colchicine alkaloids in C. autumnale.

Cell shape can be uncoupled from formononetin induction in a novel cell line from Callerya speciosa.

KEY MESSAGE: It is the first time that formononetin produced by cell culture and its accumulation was shown to be triggered by specific stress signalling linked jasmonate pathway. Callerya speciosa, an endangered traditional Chinese medicine plant, is intensively used in traditional folk medicine. To develop sustainable alternatives for the overexploitation of natural resources, a suspension cell line was created from C. speciosa. Ingredients of C. speciosa, for instance the isoflavone formononetin, are formed during a peculiar swelling response of the root, which is considered as a quality trait for commercial application. A cell strain with elongated cells was obtained by using synthetic cytokinin 6-benzylaminopurine (6-BA) and synthetic auxin picloram. Both, picloram and 6-BA, promote cell division, whereas picloram was shown to be crucial for the maintenance of axial cell expansion. We addressed the question, whether the loss of axiality observed in the maturating root is necessary and sufficient for the accumulation of formononetin. While we were able to mimic a loss of axiality for cell expansion, either by specific combinations of 6-BA and picloram, or by treatment with the anti-microtubular compound oryzalin, formononetin was not detectable. However, formononetin could be induced by the stress hormone methyl jasmonate (MeJA), as well as by the bacterial elicitor flagellin peptide (flg22), but not by a necrosis inducing protein. Combined the fact that none of these treatments induced the loss of axiality, we conclude that formononetin accumulates in response to basal defence and unrelated with cell swelling.

A modified pancreaticojejunostomy anastomotic technique using double U-sutures for laparoscopic pancreaticoduodenectomy.

Although recent advances in laparoscopic technology have popularized laparoscopic pancreatoduodenectomy (LPD), laparoscopic pancreaticojejunostomy anastomosis (PJA) still presents a major technical challenge. From February 2021 to January 2023, 42 patients underwent LPD with modified double U-suture PJA. Data on the demographic characteristics and clinical results of these patients were investigated. The median operation time was 316 min (249-596 min). The median PJA time was 32 min (25-40 min). The median intraoperative blood loss was 150 mL (50-500 mL). The median postoperative stay was 12 days (7-30 days). Complications occurred in 10 (23.8%) patients, including two cases (4.8%) of delayed gastric emptying and nine cases (21.4%) of postoperative pancreatic fistula (POPF). One patient presented delayed gastric emptying and POPF. Eight patients (19.0%) experienced biochemical leakage, and one patient (2.4%) had grade B POPF. Laparoscopic double U-suture PJA is a feasible and safe technique for performing LPD.

Establishing and Externally Validating a Hemoglobin, Albumin, Lymphocyte, and Platelet (HALP) Score-Based Nomogram for Predicting Early Recurrence in BCLC Stage 0/A Hepatocellular Carcinoma Patients After Radical Liver Resection: A Multi-Center Study.

Purpose: Early recurrence (ER) is associated with poor prognosis in hepatocellular carcinoma (HCC). In this study, we developed and externally validated a nomogram based on the hemoglobin, albumin, lymphocytes, and platelets (HALP) score to predict ER for patients with BCLC stage 0/A HCC who underwent radical liver resection. Patients and Methods: A total of 808 BCLC stage 0/A HCC patients from six hospitals were included in this study, and they were assigned to a training cohort (n = 500) and an external validation cohort (n = 308). We used univariate and multivariate Cox regression analysis to identify the independent risk factors for disease-free survival (DFS). We also established and externally validated a nomogram based on these risk predictors. The nomogram was evaluated using the area under the receiver operating characteristic curve (AUC), the concordance index (C-index), the calibration curve, decision curve analysis (DCA), and Kaplan‒Meier analysis. Results: Multivariate COX regression showed that HBV DNA ≥10,000 IU/mL (P < 0.001), HALP score ≤38.20 (P < 0.001), tumor size (P = 0.003), clinically significant portal hypertension (P = 0.001), Edmondson-Steiner grade (III-IV) (P = 0.007), satellite nodules (P < 0.001), and MVI (P = 0.001) were independent risk factors for post-operative tumor recurrence. The AUC of our nomogram for predicting the 2-year and 5-year DFS was 0.756 and 0.750, respectively, in the training cohort and 0.764 and 0.705, respectively, in the external validation cohort. We divided the patients into low-, intermediate- and high-risk groups according to the risk score calculated by the nomogram. There were statistically significant differences in the DFS and overall survival (OS) among the three groups of patients (P < 0.001). Conclusion: We developed and externally validated a new nomogram, which is accurate and can predict ER in BCLC stage 0/A HCC patients after curative liver resection.

Circ_0008234 regulates the biological process of gallbladder carcinoma by targeting the miR-204-5p/FGFR2 axis.

BACKGROUND: Gallbladder carcinoma (GBC) is a common cancer disease with high mortality. Circular RNA_0008234 (circ_0008234) has been shown to play a key role in many tumors, including GBC. However, the function between circ_0008234 and microRNA-204-5p (miR-204-5p) in the progression of GBC has not been clarified. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expressions of circ_0008234, miR-204-5p and fibroblast growth factor receptor-2 (FGFR2) in GBC cells and tissues. Western blot was used to detect the expression of relative proteins. Cell proliferation, apoptosis, invasion and migration were detected by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, thymidine analog 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, transwell assay and wound healing assay. Mechanically, the interaction of miR-204-5p with circ_0008234/FGFR2 was notarized by dual-luciferase reporter assay. A xenotransplantation model was established to study the role of circ_0008234 in vivo. RESULTS: Circ_0008234 and FGFR2 were highly expressed in GBC tissues and cells. Silencing circ_0008234 down-regulated cell proliferation, migration and invasion of NOZ and SGC-996 cells, while miR-204-5p inhibitors reversed these effects. In addition, overexpression of FGFR2 restored the cell malignant behavior of GBC cells inhibited by miR-204-5p mimic. Animal experiments confirmed the anti-tumor effect of silenced circ_0008234 in vivo. CONCLUSION: Circ_0008234 mediated GBC via the miR-204-5p/FGFR2 axis, providing a novel targeted therapy for gallbladder carcinoma.

Borealin Promotes Tumor Growth and Metastasis by Activating the Wnt/ß-Catenin Signaling Pathway in Hepatocellular Carcinoma.

Background and Aims: Hepatocellular carcinoma (HCC) is a common malignant disease with high morbidity and mortality throughout the world. While Borealin is a putative oncogene that is dysregulated in multiple tumors, its exact role in HCC remains less investigated. Methods: Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) assays were employed to examine the relative amount of Borealin. Gene set enrichment analysis (GSEA) and other bioinformatic analyses were implemented to probe into the potential functions of Borealin. The biological roles and mechanisms of Borealin in the tumorigenesis and development of HCC were further evaluated using a battery of functional assays in vivo and in vitro. Results: Borealin was enhanced in the HCC tissue samples and hepatoma cells when compared with the nontumor tissues and normal liver cells. Higher Borealin expression was positively linked with advanced pathological phenotypes and inferior overall survival. The overexpression of Borealin promoted the cells' abilities on proliferation, invasion and epithelial-mesenchymal transition (EMT) in vitro, facilitated tumor growth and lung metastasis in vivo, whereas the silencing of Borealin inhibited these capabilities in vitro. Furthermore, Borealin interacted with ß-catenin and further activated the Wnt/ß-catenin signaling pathway, which endowed HCC cells with highly aggressive and metastatic capabilities. Conclusion: Borealin was identified as an oncogene that could promote HCC growth and metastasis by activating the WNT/ß-catenin signaling pathway. These findings extended the understanding of Borealin in HCC tumorigenesis and development and highlighted the significance of Borealin in HCC diagnosis and treatment.

Pathogenicity and transmissibility of current H3N2 swine influenza virus in Southern China: A zoonotic potential.

Swine are considered as 'mixing vessels' of influenza A viruses and play an important role in the generation of novel influenza pandemics. In this study, we described that the H3N2 swine influenza (swH3N2) viruses currently circulating in pigs in Guangdong province carried six internal genes from 2009 pandemic H1N1 virus (pmd09), and their antigenicity was obviously different from that of current human H3N2 influenza viruses or recommended vaccine strains (A/Guangdong/1194/2019, A/Hong Kong/4801/2014). These swH3N2 viruses preferentially bonded to the human-like receptors, and efficiently replicated in human, canine and swine cells. In addition, the virus replicated in turbinate and trachea of guinea pigs, and efficiently transmitted among guinea pigs, and virus shedding last for 6 days post-infection (dpi). The virus replicated in the respiratory tract of pigs, effectively transmitted among pigs, and virus shedding last until 9 dpi. Taken together, these current swH3N2 viruses might have the zoonotic potential. Strengthening surveillance and monitoring the pathogenicity of such swH3N2 viruses are urgently needed.

[Detection and clinical significance of Notch1 methylation in breast cancer and intraductal proliferative breast lesions].

OBJECTIVE: To explore the relevance between the promoter methylation status of Notch1 gene and the invasive ductal carcinoma and ductal hyperplastic lesions of the breast. METHODS: Methylation status of Notch1 gene in human breast invasive ductal carcinoma (IDC, n = 89), ductal carcinoma in situ (DCIS, n = 20), atypical ductal hyperplasia (ADH, n = 11) and usual ductal hyperplasia (UDH, n = 20) were quantitatively evaluated by MALDI-TOF MS. The expression of Notch1 protein was detected by immunohistochemical stain (SP method). RESULTS: Positive expression rates of Notch1 protein in IDC and DCIS were 91.0% (81/89) and 75.0% (15/20), respectively, which were significantly higher than those of ADH (4/11) and UDH (30.0%, 6/20;P < 0.05). Notch1 protein expression was correlated significantly with lymph node metastasis, pathological grades and TNM stages of IDC. The mean methylation levels of Notch1 gene at CpG_3, CpG_4.5 and CpG_8 significantly decreased in IDC group compared with those of DCIS, ADH and UDH groups (P < 0.0083). In breast carcinomas, the mean methylation rates of Notch1 gene at CpG_4.5, CpG_10.11, and CpG_14.15.16 loci in cases with axillary node metastasis were significantly lower than those without axillary node metastasis (P < 0.05); and the methylation rates at CpG_14.15.16 and CpG_18 loci in stage Iwere lower than that in stage II, further lower than that in stage III (P < 0.05); and that in CpG_1.2, CpG_12.13 loci in grade I (highly-differentiated group) were higher than that in grade II (moderate-differentiated group) and grade III (poorly-differentiated group) (P < 0.05); and the methylation rates at CpG_3, CpG_8 and CpG_14.15.16 loci in ER(+) PR(+) HER2(-) group were lower than that in ER(-) PR(-) HER2(+) group (P < 0.05). CONCLUSIONS: There is an overall hypomethylation of Notch1 gene in breast invasive ductal carcinomas with corresponding over-expression of Notch1 protein. This inverse correlation show that the alteration of protein expression result from hypomethylation oncogene Notch1, and this change may have important significance in breast tumorigenesis and the development. Specific hypomethylation at CpG_3, CpG_ 4.5 and CpG_8 loci of Notch1 gene may play a role in the pathogenesis of breast carcinoma, suggesting the progression and/or malignant transformation from benign glandular lesions of the breast.

Cardamonin Promotes the Apoptosis and Chemotherapy Sensitivity to Gemcitabine of Pancreatic Cancer Through Modulating the FOXO3a-FOXM1 Axis.

Cardamonin (CAR), a flavone existing in the Alpinia plant, has been found to modulate multiple biological activities, including antioxidant, anti-inflammatory, and anti-tumor effects. Nevertheless, the influence of CAR on pancreatic cancer (PC) is less understood. Here, we conducted in vitro and in vivo experiments to explore the functions of CAR on PC cells' proliferation, apoptosis and chemosensitivity to gemcitabine (GEM). The growth of PC cells (including PANC-1 and SW1990) was evaluated by the cell counting kit-8 assay, colony formation assay and xenograft tumor experiment. Besides, the apoptosis was determined by flow cytometry and western blot (WB). Moreover, the FOXO3a-FOXM1 pathway expression was tested by reverse transcription-polymerase chain reaction and WB. Our data suggested that CAR restrained cell proliferation, growth and expedited apoptosis both in vitro and in vivo. Moreover, CAR sensitized PC cells to GEM. Mechanistically, CAR heightened FOXO3a while repressed FOXM1. Further loss-of-function assays revealed that down-regulating FOXO3a markedly dampened the anti-tumor effect induced by CAR and accelerated the FOXM1 expression. Our data confirmed that CAR exerted an anti-tumor function in PC dependently by modulating the FOXO3a-FOXM1 axis.

Prognostic Factors and Clinical Characteristics of Duodenal Adenocarcinoma With Survival: A Retrospective Study.

BACKGROUND: To evaluate the clinical risk factors that influence the overall survival in patients with duodenal adenocarcinoma (DA) after tumor resection. METHODS: This study retrospectively analyzed 188 patients who underwent tumor resection for DA between January 2005 and June 2020 at Xiangyang Central Hospital. RESULTS: The median survival of the patients who underwent resectional operation was 54 months, longer than of those who underwent palliative surgery (20.8 months) (2,916.17; 95% CI, 916.3-9,280.5; p < 0.001). Survival of non-ampullary duodenal carcinoma patients (50.3 months; 95% CI, 39.7-61.8) was similar to that of ampullary duodenal carcinoma patients (59.3 months; 95% CI, 38.6-66.7) but was significantly better than that of papillary adenocarcinoma patients (38.9 months; 95% CI, 29.8-54.8; p = 0.386). Those with intestinal-type ductal adenocarcinomas had a longer median overall survival than those with the gastric type (61.8 vs. 46.7 months; p < 0.01) or pancreatic type (32.2 months; p < 0.001). Clinical DA samples had significantly diverse expressions of ATG12, IRS2, and IGF2. Higher expressions of the ATG12 and IRS2 proteins were significantly correlated with worse survival. Multivariate Cox regression analysis revealed that lymph node metastasis (hazard ratio (HR), 6.44; 95% CI, 3.68-11.27; p < 0.0001), margin status (HR, 4.94; 95% CI, 2.85-8.54; p < 0.0001), and high expression of ATG12 (HR, 1.89; 95% CI, 1.17-3.06; p = 0.0099) were independent prognostic factors negatively associated with survival in patients undergoing curative resection. There was no survival difference between the groups with ampullary, non-ampullary, and papillary adenocarcinomas treated with adjuvant chemotherapy (p = 0.973). CONCLUSION: Gastric/pancreatic type, high expression of ATG12, lymph node metastases, and margin status were negative prognosticators of survival in patients with DAs than in those with tumor anatomical location. Curative resection is the best treatment option for appropriate patients.

Molecular Characteristics, Antigenicity, Pathogenicity, and Zoonotic Potential of a H3N2 Canine Influenza Virus Currently Circulating in South China.

Canine influenza viruses (CIVs) could be a source of influenza viruses which infect humans because canine are important companion pets. To assess the potential risk of H3N2 CIVs currently circulating in southern China to public health, biological characteristics of A/canine/Guangdong/DY1/2019 (CADY1/2019) were detected. CADY1/2019 bound to both avian-type and human-type receptors. CADY1/2019 had a similar pH value for HA protein fusion to human viruses, but its antigenicity was obviously different from those of current human H3N2 influenza viruses (IVs) or the vaccine strains recommended in the North hemisphere. CADY1/2019 effectively replicated in the respiratory tract and was transmitted by physical contact among guinea pigs. Compared to human H3N2 IV, CADY1/2019 exhibited higher replication in MDCK, A549, 3D4/21, ST, and PK15 cells. Sequence analysis indicated that CADY1/2019 is an avian-origin virus, and belongs to the novel clade and has acquired many adaptation mutations to infect other mammals, including human. Taken together, currently circulating H3N2 CIVs have a zoonotic potential, and there is a need for strengthening surveillance and monitoring of their pathogenicity.

Characterisation, expression and functional analysis of PAL gene family in Cephalotaxus hainanensis.

Phenylalanine ammonia lyase (PAL) is the first committed step in the formation of phenylpropanoids, and catalyses the deamination of L-phenylalanine (L-Phe) to yield cinnamic acid. While PALs are common in plants, PAL genes involved in alkaloid biosynthesis in Cephalotaxus hainanensis have never been described. To obtain better knowledge of PAL genes and their number and function involved in Cephalotaxus alkaloid biosynthesis four PAL genes were screened and cloned. In vitro enzymatic analysis showed that all four PAL recombinant proteins could convert L-Phe to product trans-cinnamic acid, and showed strict substrate specificity. Moreover, the expression profiles of four ChPALs were analysed using qRT-PCR, which showed that they had higher transcript levels in roots and stems, and that different ChPALs displayed different response sensitivities and change patterns in response to stimuli. Several metabolic compounds were measured in stimulated leaves using UPLC-MS, and indicating the concentration of Cephalotaxus alkaloids and cinnamic acid in leaves subjected to different conditions. These concentrations increased significantly after treatment with 100 mM NaCl, 100 mM mannitol, 100 µM SA and 10 µM ABA. The expression levels of four PAL genes showed indications of upregulation after treatment. These results supply an important foundation for further research on candidate genes involved in the biosynthesis of Cephalotaxus alkaloids.

Variation and Molecular Basis for Enhancement of Receptor Binding of H9N2 Avian Influenza Viruses in China Isolates.

Currently, H9N2 avian influenza viruses (H9N2 AIVs) globally circulate in poultry and have acquired some adaptation to mammals. However, it is not clear what the molecular basis is for the variation in receptor-binding features of the H9N2 AIVs. The receptor-binding features of 92 H9N2 AIVs prevalent in China during 1994-2017 were characterized through solid-phase ELISA assay and reverse genetics. H9N2 AIVs that circulated in this period mostly belonged to clade h9.4.2. Two increasing incidents occurred in the ability of H9N2 AIVs to bind to avian-like receptors in 2002-2005 and 2011-2014. Two increasing incidents occurred in the strength of H9N2 AIVs to bind to human-like receptors in 2002-2005 and 2011-2017. We found that Q227M, D145G/N, S119R, and R246K mutations can significantly increase H9N2 AIVs to bind to both avian- and human-like receptors. A160D/N, Q156R, T205A, Q226L, V245I, V216L, D208E, T212I, R172Q, and S175N mutations can significantly enhance the strength of H9N2 AIVs to bind to human-like receptors. Our study also identified mutations T205A, D208E, V216L, Q226L, and V245I as the key sites leading to enhanced receptor binding of H9N2 AIVs during 2002-2005 and mutations S119R, D145G, Q156R, A160D, T212I, Q227M, and R246K as the key sites leading to enhanced receptor binding of H9N2 AIVs during 2011-2017. These findings further illustrate the receptor-binding characteristics of avian influenza viruses, which can be a potential threat to public health.

Epithelial-mesenchymal transition induced by MyoD inhibits growth of high metastatic colorectal cancer.

OBJECTIVES: The study aimed to investigate the tumor-suppressing factor myogenicity differentiation factor (MyoD) against high metastatic colorectal cancer through its powerful transformation by which the tumor cells were converted into muscle cells or other cells to inhibit the malignant proliferation of tumor cells. METHODS: The roles of MyoD in colon cancer proliferation, invasion and migration were analyzed by CCK-8 assay and Transwell, and EMT by real-time PCR and Western blot. The secretion of TGFß1 was assayed by ELISA and activation of p-Smad2/3 were assayed by western blot. The effects of MyoD on intestinal cancer growth and EMT in vivo were also analyzed. RESULTS: We found MyoD inhibited the proliferation, invasion and migration of colon cancer cell. Moreover, MyoD inhibited the expression of E-cadherin and promoted the expression of vimentin and α-SMA. The secretion of TGFß1 increased and p-Smad2/3 was activated after MyoD expression. MyoD also inhibits intestinal cancer growth and promoted EMT in vivo. CONCLUSION: Our findings indicate that MyoD inhibited cancer progression and metastasis by promoting EMT through TGF-ß1/Smad2/3 activation, which provide new support for MyoD maybe as a novel anti-cancer method for the treatment of colon cancer in the future.

Evaluation of reference genes for normalizing RT-qPCR in leaves and suspension cells of Cephalotaxus hainanensis under various stimuli.

BACKGROUND: Reverse transcription quantitative real-time PCR (RT-qPCR) is a widely used approach for investigating gene expression levels in plants because of its high reproducibility, sensitivity, accuracy and rapidness. Evaluation of reference genes for normalizing RT-qPCR data is a necessary step, especially in new plant varieties. Cephalotaxus hainanensis is a precious medicinal plant belonging to the family of Cephalotaxaceae and no RT-qPCR studies have been reported on it. RESULTS: In this study, 9 candidate reference genes were selected from the transcriptome data of C. hainanensis; 3 statistical algorithms (geNorm, NormFinder, BestKeeper) were applied to evaluate their expression stabilities through 180 samples under 6 stimuli treatments in leaves and leaf-derived suspension cultured cells; a comprehensive stabilities ranking was also performed by RefFinder. The results showed that suitable reference genes in C. hainanensis should be selected for normalization relative to different experimental sets. 18S showed a higher stability than other candidate reference genes which ranked at the top two suitable genes under all experimental setups in this study. CONCLUSION: This study is the first to evaluate the stability of reference genes in C. hainanensis and supply an important foundation to use the RT-qPCR for an accurate and far-reaching gene expression analysis in C. hainanensis.

Glycinebetaine Biosynthesis in Response to Osmotic Stress Depends on Jasmonate Signaling in Watermelon Suspension Cells.

Glycinebetaine is an important non-toxic osmoprotectant, which is accumulated in higher plants under various stresses. The biosynthesis of glycinebetaine achieved via is a two-step oxidation from choline and betaine aldehyde, catalyzed by choline monooxygenase (CMO) and betaine aldehyde dehydrogenase (BADH), respectively. Up-regulated gene expression of BADH and CMO induced by stress is clearly observed, but the signal transduction is poorly understood. Here, glycinebetaine accumulation in response to osmotic stress and growth recovery induced by exogenous glycinebetaine were observed in a watermelon cell line. When tracing back to the genome sequence of watermelon, it shows that there exists only one member of ClCMO or ClBADH corresponding to glycinebetaine biosynthesis. Both genes harbor a CGTCA-motif in their promoter region which is involved in methyl jasmonate (MeJA)-responsiveness. Amongst MeJA, Ethephon, abscisic acid (ABA), and salicylic acid (SA), MeJA was most effective in gene inducing the expression of ClCMO and ClBADH, and the accumulation of glycinebetaine could also reach an amount comparable to that after osmotic stress by mannitol. Moreover, when ibuprofen (IBU), a JA biosynthesis inhibitor, was pre-perfused into the cells before osmotic stress, glycinebetaine accumulation was suppressed significantly. Interestingly, newly grown cells can keep a high content of glycinebetaine when they are sub-cultured from osmotic stressed cells. This study suggests that osmotic stress induced glycinebetaine biosynthesis occurs via JA signal transduction and not only plays a key role in osmotic stress resistance but also contributes to osmotic stress hardening.

MicroRNA-like RNAs in plant pathogenic fungus Fusarium oxysporum f. sp. niveum are involved in toxin gene expression fine tuning.

MicroRNA-like RNAs (milRNAs) are short non-coding regulatory sRNAs which play an important role in regulating gene expression at the post-transcriptional level by targeting mRNAs for degradation or inhibiting protein translation. To explore the presence of milRNAs in Fusarium oxysporum f. sp. niveum (Fon) and analyze their expression at different propagules, two categories of sRNAs were identified from Fon hyphae and microconidia using illumina sequencing. A total of 650,960 and 561,114 unique sRNAs were obtained from the hyphae and microconidia samples. With a previously constructed pipeline to search for microRNAs, 74 and 56 milRNA candidates were identified in hyphae and microconidia, respectively, based on the short hairpin structure analysis. Global expression analysis showed an extensively differential expression of sRNAs between the two propagules. Altogether, 78 significantly differently expressed milRNAs were identified in two libraries. Target prediction revealed two interesting genes involved in trichothecene production, necrosis and ethylene-inducing peptide 1 (NEP1) biosynthesis and in silico analysis indicated that they were down-regulated by Fon-miR7696a-3p and Fon-miR6108a. The expression levels of these two milRNAs were further validated by qRT-PCR and the results were consistent. The negative correlation of the expression levels between these two milRNAs and their potential target genes imply that they play a role in trichothecene and NEP1 biosynthesis. And this negative regulation for toxin-related gene expression is more specific in microconidia. The present study provides the first large-scale characterization of milRNAs in Fon and the comparison between hyphae and microconidia propagules gives an insight into how milRNAs are involve in toxin biosynthesis.