CircRNA LDLR promotes proliferation and aerobic glycolysis of gastric cancer cells by targeting CHD1 with miR-449b-5p.

Background/aim: Circular RNAs can serve as detection biomarkers and therapeutic targets for tumors. Our study aimed to elucidate the mechanisms associated with circRNA LDLR (circLDLR) in gastric cancer (GC) proliferation and aerobic glycolysis. Materials and methods: Expression signatures of circLDLR, miR-449b-5p, and CHD1 were examined in GC samples using quantitative PCR. Proliferation ability of MKN-45 cells was assessed via CCK-8 and EdU assays, and cell apoptosis was measured by flow cytometry. Glucose uptake, lactate production, ATP/ADP ratios, and NAD+/NADH ratios in cell supernatants were quantified to evaluate aerobic glycolysis. Subcellular isolation assay, quantitative PCR, immunoblot analysis, RNA immunoprecipitation (RIP), and dual luciferase reporter assay were employed to investigate the relationship between genes. Results: Expression of circLDLR and CHD1 was elevated, while miR-449b-5p expression decreased in GC. Functionally, overexpression of circLDLR enhanced proliferation and aerobic glycolysis and hampered apoptosis of MKN-45 cells. However, upregulation of miR-449b-5p or downregulation of CHD1 reversed these effects. CircLDLR acted as an miRNA spongeand regulated the expression of miR-449b-5p, thereby affecting CHD1 and accelerating GC malignant progression. Conclusion: CircLDLR drives the proliferation and aerobic glycolysis of GC cells by targeting CHD1 with miR-449b-5p, which is an ideal potential target for early diagnosis and clinical treatment of GC.

Axl as a potential therapeutic target for adamantinomatous craniopharyngiomas: Based on single nucleus RNA-seq and spatial transcriptome profiling.

Craniopharyngiomas (CPs), particularly Adamantinomatous Craniopharyngiomas (ACPs), often exhibit a heightened risk of postoperative recurrence and severe complications of the endocrine and hypothalamic function. The primary objective of this study is to investigate potential novel targeted therapies within the microenvironment of ACP tumors. Cancer-Associated Fibroblasts (CAFs) were identified in the craniopharyngioma microenvironment, notably in regions characterized by cholesterol clefts, wet keratin, ghost cells, and fibrous stroma in ACPs. CAFs, alongside ghost cells, basaloid-like epithelium cells and calcifications, were found to secrete PROS1 and GAS6, which can activate AXL receptors on the surface of tumor epithelium cells, promoting immune suppression and tumor progression in ACPs. Additionally, the AXL inhibitor Bemcentinib effectively inhibited the proliferation organoids and enhanced the immunotherapeutic efficacy of Atezolizumab. Furthermore, neural crest-like cells were observed in the glial reactive tissue surrounding finger-like protrusions. Overall, our results revealed that the AXL might be a potentially effective therapeutic target for ACPs.

Comparison of prognostic outcomes between endoscopic submucosal dissection and surgical treatment for early gastric cancer: a retrospective cohort study.

BACKGROUND AND AIM: The optimal management strategy for early gastric cancer (EGC) a topic of contention. This study aims to compare the prognostic outcomes of endoscopic submucosal dissection (ESD) and surgical treatment in patients diagnosed with EGC. METHODS: In thisretrospective cohort study, we analyzed data from539 patients diagnosed with EGC between January 2012 and December 2020 from two centers. We compared Clinicopathological features, procedure-related complications, recurrence rate, overall survival, and disease specific survival between the 262 patients who underwent ESD and the 277 patients who underwent surgical treatment. ESD procedures were conducted using a dual knife by experienced endoscopists, while surgical treatments included laparoscopic or open gastrectomy. Regular ollow-up examinations were conducted post-treatment. RESULTS: The two groups exhibited comparable baseline characteristics. Multivariable Cox regression analysis identified vascular invasion as a risk factor for worse recurrence-free survival (RFS), and overall survival (OS) in patients with early gastric cancer. The ESD group experienced fewer overall postoperative complications compared to the surgical treatment group. Kaplan-Meier curves demonstrated no significant differences in recurrence rate or overall survival between the two groups. CONCLUSIONS: Both ESD and surgical treatment emerged as safe and effective approaches for managing EGC. The choice of treatment should be tailored to individual patient factors. ESD can be considered an alternative treatment option for selected patients who are not suitable candidates for surgery. Further studies are warranted to determine the long-term outcomes of ESD and surgical treatment for EGC.

Intraoperative direct venous puncture and embolization for arteriovenous shunt below the conus medullaris: a prospective cohort study.

BACKGROUND: Arteriovenous shunt below the conus medullaris (AVS-BC) is easily misdiagnosed and mistreated due to its rarity. Achieving an anatomical cure solely through endovascular or surgical means is challenging. This study aimed to summarize the clinical and radiological features of AVS-BC and evaluate the safety and efficacy of hybrid techniques represented by intraoperative direct venous puncture and embolization (IVPE). METHODS: The patients with AVS-BC were grouped into those with dural, intradural, and paravertebral shunts. The patients undergoing hybrid procedures were consecutively recruited between August 2016 and July 2022. The modified Aminoff and Logue's Scale (mALS) and the modified Denis Pain and Numbness Scale (mDS) were used to evaluate motor and sensation disturbances. RESULTS: A total of 42 patients (35 males, 83.3%) were included with an average age of 57.38±10.79 years. Most patients presented with lower limb weakness and sphincter disturbances. Their preoperative average mALS score was 7.17±2.61 and the preoperative average mDS score was 3.88±1.76. There were 28 patients (66.7%) who received IVPE. The mean clinical follow-up reached 41.30±21.10 months. All patients achieved anatomical cures without permanent neurological complications. It showed a significant improvement in mALS scores after the intervention in the spinal dural arteriovenous fistula only (P=0.026). No recurrences were reported. CONCLUSIONS: Differentiating AVS-BC mainly relied on identifying supplying arteries, shunt placements, and draining veins. The hybrid technique typified by IVPE conferred a safe anatomical cure for AVS-BC.

The role of intraoperative neurophysiological monitoring in intramedullary spinal cord tumor surgery.

Intramedullary tumors are a class of central nervous system tumors with an incidence of 2 to 4%. As they are located very deep and frequently cause postoperative neurological complications, surgical resection is difficult. In recent years, many surgeons have performed electrophysiological monitoring to effectively reduce the occurrence of postoperative neurological complications. Modern electrophysiological monitoring technology has advanced considerably, leading to the development of many monitoring methods, such as SSEPs, MEPs, DCM, and EMG, to monitor intramedullary tumors. However, electrophysiological monitoring in tumor resection is still being studied. In this article, we discussed the different monitoring methods and their role in monitoring intramedullary tumors by reviewing previous studies. Intratumorally tumors need to be monitored for a summary of the condition of the patient. Only by using various monitoring methods flexibly and through clear communication between surgeons and neurophysiological experts can good decisions be made during surgery and positive surgical results be achieved.

Breaking Bad: Autophagy Tweaks the Interplay Between Glioma and the Tumor Immune Microenvironment.

Though significant strides in tumorigenic comprehension and therapy modality have been witnessed over the past decades, glioma remains one of the most common and malignant brain tumors characterized by recurrence, dismal prognosis, and therapy resistance. Immunotherapy advance holds promise in glioma recently. However, the efficacy of immunotherapy varies among individuals with glioma, which drives researchers to consider the modest levels of immunity in the central nervous system, as well as the immunosuppressive tumor immune microenvironment (TIME). Considering the highly conserved property for sustaining energy homeostasis in mammalian cells and repeatedly reported links in malignancy and drug resistance, autophagy is determined as a cutting angle to elucidate the relations between glioma and the TIME. In this review, heterogeneity of TIME in glioma is outlined along with the reciprocal impacts between them. In addition, controversies on whether autophagy behaves cytoprotectively or cytotoxically in cancers are covered. How autophagy collapses from its homeostasis and aids glioma malignancy, which may depend on the cell type and the cellular context such as reactive oxygen species (ROS) and adenosine triphosphate (ATP) level, are briefly discussed. The consecutive application of autophagy inducers and inhibitors may improve the drug resistance in glioma after overtreatments. It also highlights that autophagy plays a pivotal part in modulating glioma and the TIME, respectively, and the intricate interactions among them. Specifically, autophagy is manipulated by either glioma or tumor-associated macrophages to conform one side to the other through exosomal microRNAs and thereby adjust the interactions. Given that some of the crosstalk between glioma and the TIME highly depend on the autophagy process or autophagic components, there are interconnections influenced by the status and well-being of cells presumably associated with autophagic flux. By updating the most recent knowledge concerning glioma and the TIME from an autophagic perspective enhances comprehension and inspires more applicable and effective strategies targeting TIME while harnessing autophagy collaboratively against cancer.

Effects of ß-carboline alkaloids from Peganum harmala on the FAK/PI3K/AKT/Mtor pathway in human gastric cancer cell line SGC-7901 and tumor-bearing mice.

This study investigates the effects of ß-carboline alkaloids from Peganum harmala on FAK/PI3K/AKT/mTOR pathway in gastric cancer cell line SGC-7901 and tumor-bearing mice. Western blot, immunohistochemistry and RT-PCR were performed to detect protein and mRNA expressions of BCL-2, Bax, FAK, PI3K, AKT and mTOR. Mice model of gastric tumor was established with SGC-7901 cells. TUNEL assay was used to detect apoptosis. HE staining was used to observe morphological changes. In vitro, the protein and mRNA expressions of FAK, PI3K, AKT and mTOR in ß-carboline alkaloids groups were significantly lower than those in control and fluorouracil groups (P<0.05). BCL-2 decreased while Bax increased. In vivo, the tumor weights of ß-carboline alkaloids and fluorouracil groups were significantly lower than those of control group (P<0.05). FAK, PI3K, AKT and mTOR proteins in tumor tissues of ß-carboline alkaloids and fluorouracil groups were significantly lower than control group (P<0.05). Additionally, ß-carboline alkaloids treatment in vivo caused obvious cell necrosis and apoptosis. Conclusively, ß-carboline alkaloids can reduce FAK, PI3K, AKT and mTOR expressions at both protein and mRNA levels in SGC-7901 cells and tumor tissues formed by SGC-7901 cells. They may be targets of ß-carboline in FAK/PI3K/AKT/mTOR pathway.

Comprehensive Analysis of HDAC Family Identifies HDAC1 as a Prognostic and Immune Infiltration Indicator and HDAC1-Related Signature for Prognosis in Glioma.

Background: The histone deacetylase (HDAC) family limited accessibility to chromatin containing tumor suppressor genes by removing acetyl groups, which was deemed a path for tumorigenesis. Considering glioma remained one of the most common brain cancers with a dichotomy prognosis and limited therapy responses, HDAC inhibitors were an area of intensive research. However, the expression profiles and prognostic value of the HDACs required more elucidation. Methods: Multiple biomedical databases were incorporated, including ONCOMINE, GEPIA, TCGA, CGGA, GEO, TIMER, cBioPortal, and Metascape, to study expression profiles, prognostic value, immune infiltration, mutation status, and enrichment of HDACs in glioma. STRING and GeneMANIA databases were used to identify HDAC1-related molecules. LASSO regression, Cox regression, Kaplan-Meier plot, and receiver operating characteristic (ROC) analyses were performed for HDAC1-related signature construction and validation. Results: HDAC1 was significantly overexpressed in glioma, while HDAC11 was downregulated in glioblastoma. Except for HDAC 6/9/10, the HDAC family expression was significantly associated with glioma grade. Most of the HDAC family also correlated with glioma genetic mutations. Higher HDAC1 expression level predicted more dismal overall survival (OS) (p < 0.0001) and disease-free survival (DFS) (p < 0.0001), but a higher level of HDAC11 held more favorable OS (p = 2.1e-14) and DFS (p = 4.8e-08). HDAC4 displayed the highest mutation ratio, at 2.6% of the family. The prognostic value of HDAC1 was validated with ROC achieving 0.70, 0.77, 0.75, and 0.80 as separability for 1-, 3-, 5-, and 10-years OS predictions in glioma, respectively. Moreover, HDAC1 expression positively correlated with neutrophil (r = 0.60, p = 2.88e-47) and CD4+ T cell infiltration (r = 0.52, p = 3.96e-35) in lower-grade glioma. The final HDAC1-related signature comprised of FKBP3, HDAC1 (Hazard Ratio:1.49, 95%Confidence Interval:1.20-1.86), PHF21A, RUNX1T1, and RBL1, and was verified by survival analysis (p < 0.0001) and ROC with 0.80, 0.84, 0.83, and 0.88 as separability for 1-, 3-, 5-, and 10-years OS predictions, respectively. The signature was enriched in chromatin binding. Conclusion: HDAC family was of clinical significance for glioma. Most of the HDAC family significantly correlated with the glioma grade, IDH1 mutation, and 1p/19q codeletion. HDAC1 was both a prognostic and immune infiltration indicator and a central component of the HDAC1-related signature for precise prognosis prediction in glioma.

Evaluation of Dry Eye after Implantable Collamer Lens Surgery.

OBJECTIVES: To evaluate dry eye (DE) and associated meibomian gland dysfunction parameters after Implantable Collamer Lens (ICL) surgery. METHODS: This is a prospective observational case series. Patients who underwent ICL implantation without previous ocular diseases or ophthalmic treatments were enrolled. Their Ocular Surface Disease Index (OSDI), noninvasive breakup time (NIBUT), meibography, slit-lamp examination of the lid margin, corneal fluorescein staining (CFS), and Schirmer test I were examined preoperatively and at 1 and 3 months postoperatively. RESULTS: A total of 117 eyes of 60 patients were enrolled, and 107 eyes completed 3-month follow-up period. OSDI, lid marginal abnormality, and meibomian gland (MG) secretion, and meibum quality score were significantly higher at 1 month postoperatively and recovered partially at 3 months after surgeries, while NIBUT was significantly decreased all the time. Patients with previous DE symptoms (OSDI score ≥12) showed not only lower Schirmer and TBUT values but also higher CFS, lid margin score, MG loss, MG secretion, and meibum quality scores compared with those in the control group after operations. Low Schirmer, NIBUT values, and high meibum quality score were determined as risk factors for DE symptoms after ICL surgery. CONCLUSIONS: ICL implantation has a bad influence on the ocular surface and MG functions. The influence may be more obvious in patients with existing DE.

Development of Autophagy Signature-Based Prognostic Nomogram for Refined Glioma Survival Prognostication.

The current glioma classification could be optimized to cover such a separate and individualized prognosis ranging from a few months to over ten years. Considering its highly conserved role and potential in therapies, autophagy might be a promising element to be incorporated as a refinement for improved survival prognostication. The expression and RNA-seq data of 881 glioma patients from the Gene Expression Omnibus and The Cancer Genome Atlas were included, mapped with autophagy-related genes. Weighted gene coexpression network analysis and Cox regression analysis were used for the autophagy signature establishment, which composed of MUL1, NPC1, and TRIM13. Validations were represented by Kaplan-Meier plots and receiver operating curves (ROC). Cluster analysis suggested the IDH1 mutant involved in the favorable prognosis of the signature clusters. The signature was also immune-related shown by the Gene Ontology analysis and the Gene Set Enrichment Analysis. The high signature risk group held a higher ESTIMATE score (p = 2.6e - 11) and stromal score (p = 1.8e - 10). CD276 significantly correlated with the signature (r = 0.51, p < 0.05). The final nomogram integrated with the autophagy signature, IDH1 mutation, and pathological grade was built with accuracy and discrimination (1-year survival AUC = 0.812, 5-year survival AUC = 0.822, and 10-year survival AUC = 0.834). Its prognostic value and clinical utility were well-defined by the superiority in the comparisons with the current World Health Organization glioma classification in ROC (p < 0.05) and decision curve analysis. The autophagy signature-based IDH1 mutation and grade nomogram refined glioma classification for a more individualized and clinically applicable survival estimation and inspired potential autophagy-related therapies.

[Mechanism of ß-carboline alkaloids inhibiting migration and invasion of SGC-7901 cells].

To explore the mechanism of ß-carboline alkaloids inhibiting the migration and invasion of SGC-7901 cells and its correlation with FAK gene expression,CCK-8 method was used to determine the inhibitory rate of ß-carboline alkaloids on the proliferation of gastric cancer SGC-7901 cells under different concentrations.The effect of ß-carboline alkaloids on the migration and invasion of SGC-7901 cells was used by Transwell compartment.Detection of mRNA and protein expression of FAK genes were used by qRT-PCR and Western blot.Then si-FAK-1051 recombinant plasmid was transfected into SGC-7901 cells.FAK gene silencing effect was identified by qRT-PCR and Western blot technique again.Finally,the effects of FAK gene silencing on proliferation and migration of gastric cancer SGC-7901 cells were detected by CCK-8 kit and Transwell chamber assay respectively.With the increase of the concentration ofß-carboline alkaloids,the inhibitory rate of SGC-7901 cells in human gastric cancer cells increased gradually,with IC5013.364 mg·L-1.The number of SGC-7901 cells of Transwell compartment in the positive experimental group(5-FU,5 mg·L-1) and the ß-carboline alkaloids group decreased significantly(P<0.01) and the number of SGC-7901 cells in the ß-carboline alkaloids group was significantly lower than that in the positive experimental group(P<0.01).Compared with the blank control group,the mRNA and protein expression level of FAK genes in the positive experimental group was significantly lower than that in the experimental group of ß-carboline alkaloids(P<0.05).After transfection of si-FAK-1051 into gastric cancer SGC-7901 cells,the expression of mRNA and protein of FAK gene was significantly down regulated(P<0.05).SGC-7901 cell proliferation and cell migration ability also decreased significantly(P<0.05).ß-carboline alkaloids are more effective than 5-FU in inhibiting migration and invasion of gastric cancer SGC-7901 cells,and the mechanism may be related to the inhibition of mRNA and protein expression of FAK gene by ß-carboline alkaloids.

High level of serum Cripto-1 in hepatocellular carcinoma, especially with hepatitis B virus infection.

BACKGROUND: Human Cripto-1 (CR-1), a member of the epidermal growth factor-Cripto-1/FRL-1/Cryptic protein family (EGF-CFC), is highly expressed in a variety of human cancers. We aimed to detect serum CR-1 level in liver diseases especially in hepatocellular carcinoma (HCC) patients. METHODS: Serum CR-1 level was Sandwich-type enzyme-linked immuno sorbent assay (ELISA) detected in 330 patients with liver diseases including HCC, cirrhosis, and chronic hepatitis and 50 volunteers without hepatitis B virus (HBV) or hepatitis C virus (HCV) infection as control. RESULTS: The serum CR-1 level was significantly higher in HCC patients than volunteer controls and it was also significantly higher in HBV-related HCC than HCV-related HCC. In addition, serum CR-1 level was correlated with serum alpha-feto-protein (AFP) in HBV-related HCC patients. The serum CR-1 was also higher in cirrhosis and chronic hepatitis than volunteer controls. The serum CR-1 in HBV-related cirrhosis was higher than chronic hepatitis B, but there was no significant difference between HCV-related cirrhosis and chronic hepatitis C. CONCLUSIONS: Serum CR-1 was higher in HCC patients and might serve as a complementary biomarker to clinical diagnosis of HBV-related HCC. The high level of serum CR-1 in HBV-related liver disease might be partly attributed to HBV infection.

HDAC3 Expression Correlates with the Prognosis and Grade of Patients with Glioma: A Diversification Analysis Based on Transcriptome and Clinical Evidence.

OBJECTIVE: This study aimed to clarify the relationship between histone deacetylase 3 (HDAC3) expression and the prognosis as well as the grade of patients with glioma. METHODS: The quantitative real-time polymerase chain reaction was profiled to examine the HDAC3 expression in glioma and normal glial cell lines. An Oncomine database analysis and prognosis analysis were performed. The correlation between World Health Organization (WHO) grade and HDAC3 was analyzed by Spearman rank correlation test. A meta-analysis was performed to confirm the conclusion. RESULTS: HDAC3 RNA overexpression in glioma cell lines was detected (P < 0.05). Four data sets were screened from the Oncomine database and showed that the expression level of HDAC3 was consistently higher in glioma than in normal tissue (P < 0.001). The prognostic analysis of 325 glioma samples from the Chinese Glioma Genome Atlas showed that patients with low HDAC3 expression had significantly better overall survival (OS) and progression-free survival (PFS) than did patients with high HDAC3 expression [hazard ratio [HR], 1.992; 95% confidence interval [CI], 1.490-2.662; P < 0.0001 and HR, 1.874; 95% CI, 1.412-2.487; P < 0.0001, respectively]. Both the WHO grade III group and the WHO grade IV group expressed significantly higher messenger RNA (mRNA) level than did the WHO grade II group (P < 0.05). Four cohort studies consisting of 490 patients were included in the meta-analysis. The pooled data of subgroup analysis showed significantly longer OS in low HDAC3 mRNA level [HR, 3.38; 95% CI, 1.80-6.37; P = 0.0002]. CONCLUSIONS: HDAC3 mRNA was expressed more in glioma than in the normal glial cell line. Low HDAC3 mRNA expression levels predicted better OS. HDAC3 expression could be a biomarker to discriminate glioma grade.

Ras GTPase-Activating-Like Protein IQGAP1 (IQGAP1) Promotes Breast Cancer Proliferation and Invasion and Correlates with Poor Clinical Outcomes.

BACKGROUND Breast cancer is one of the most common female cancers in the world. As a key integrator of cell signaling pathways, IQGAP1 contributes to the development and progression of several cancers. However, the exact effects and molecular mechanisms of IQGAP1 in breast cancer progression remain poorly understood. MATERIAL AND METHODS In the present study, IQGAP1 expression was measured in 96 paired breast cancer samples and the corresponding adjacent non-cancerous tissues by immunohistochemistry and quantitative polymerase chain reaction. To further explore the biological function of IQGAP1 in breast cancer cells, we knocked down IQGAP1 expression in MCF-7 cells and overexpressed it in SK-BR-3 cells. RESULTS IQGAP1 was specifically upregulated in breast cancer tissues compared with the corresponding adjacent non-cancerous tissues. Moreover, IQGAP1 expression was positively correlated with breast cancer survival rate. IQGAP1 also promoted breast cancer cell proliferation and cell cycle progression and suppressed apoptosis. CONCLUSIONS In conclusion, our results suggest that IQGAP1 plays an important role in the cell proliferation and invasion of human breast cancer cells, thus indicating that IQGAP1 may be a potential therapeutic target for the treatment of human breast cancer.

Effects of the Methylmalonyl-CoA Metabolic Pathway on Ansamitocin Production in Actinosynnema pretiosum.

Ansamitocins, which may have antitumor activity, are important secondary metabolites produced by Actinosynnema pretiosum sp. auranticum ATCC 31565. As one of the precursors for ansamitocin biosynthesis, methylmalonyl-CoA may be a critical metabolic node for secondary metabolism in A. pretiosum. In this study, we investigated two key enzymes related to the methylmalonyl-CoA metabolic pathway: methylmalonyl-CoA mutase (MCM) and propionyl-CoA carboxylase (PCC). For MCM, inactivation of the asm2277 gene (encoding the large subunit of MCM) resulted in 3-fold increase in ansamitocin P-3 (AP-3) production (reaching 70 mg/L) compared with that in wild-type A. pretiosum. The three genes responsible for PCC were asm6390, encoding propionyl-CoA carboxylase beta chain, and asm6229 and asm6396, which encoded biotin carboxylases, respectively. Heterogeneous overexpression of the amir6390 gene alone and concurrent overexpression of amir6390 with both amir6396 and amir6229 were carried out, and the resulting engineered strains could produce AP-3 at levels that were 1.6-fold and 3-fold (28.3 and 51.5 mg/L in flask culture, respectively) higher than that in the wild-type strain. These results suggested that eliminating the bypass pathways and favoring the precursor synthetic pathway could effectively increase ansamitocin production in A. pretiosum.

Enhancement of UDPG synthetic pathway improves ansamitocin production in Actinosynnem pretiosum.

Ansamitocin P-3 (AP-3), an amacrocyclic lactam compound, is produced by Actinosynnema pretiosum. As a group of maytansinoid antibiotics, ansamitocins have an extraordinary antitumor activity by blocking the assembly of tubulin forming into functional microtubules. The biosynthesis of ansamitocins is initialized by the formation of UDP-glucose (UDPG) which is converted from glucose-1-phosphate (G1P). In this study, we focused on the influence of enhancement of UDPG biosynthesis on the production of ansamitocins in A. pretiosum. The homologous overexpressions of phosphoglucomutase, starch phosphorylase, and UTP-G1P uridylyltransferase, respectively, could largely increase the pool sizes of G1P and UDPG and result in improved AP-3 production. The elevated intracellular glucose-6-phosphate (G6P) level provided by the enhanced glyconeogenesis had, however, no significant effects on the biosynthesis of AP-3. The G6P-G1P-UDPG pathway was therefore systematically engineered by multiple genetic modifications, and a significant increase in AP-3 production was achieved (168 mg/L of AP-3 in flask culture, 40 % higher than the control strain). We also found that the enhancement of starch assimilation pathway could also improve the assembly of AP-3 to some extent. In addition, heterologous gene overexpression from Actinosynnema mirum could result in more AP-3 biosynthesis in comparison to the corresponding homologous overexpression, suggesting an alternative and promising avenue of metabolic engineering strategy for improving AP-3 production.

Cytotoxic effects of ß-carboline alkaloids on human gastric cancer SGC-7901 cells.

To investigate the cytotoxic effects of ß-carboline alkaloids on human gastric cancer SGC-7901 cells. Human gastric cancer SGC-790s1 cells were treated with ß-carboline alkaloids at the concentration of 0, 10, 20, 30 and 40 µg/ml for 48 hr. Cell viability was measured by Cell Counting Kit-8 assay. Cell apoptosis was detected by Hoechst 33258 staining and DNA fragmentation analysis. The expression of phosphatase and tensin homolog (PTEN) and extracellular signal-regulated kinase (ERK) was examined by quantitative real-time PCR (qRT-PCR) assay and western blot analysis. ß-carboline alkaloids inhibited the growth of SGC-7901 cells concentration dependently. ß-carboline alkaloids treated SGC-7901 cells displayed apoptotic nuclei as detected using Hoechst 33258 staining. ß-carboline alkaloids also induced DNA ladder, indicative of apoptosis in SGC-7901 cells concentration-dependently. Furthermore, ß-carboline alkaloids increased PTEN and decreased ERK mRNA expression in SGC-7901 cells in a concentration dependent manner. They also increased PTEN and decreased ERK protein expression. ß-carboline alkaloids inhibit the growth and induce apoptosis of SGC-7901 cells. The cytotoxic effects of ß-carboline alkaloids might correlate with increased PTEN expression and decreased ERK expression in SGC-7901 cells.

Correlation between vascular endothelial growth factor levels and prognosis of hepatocellular carcinoma patients receiving radiofrequency ablation.

This study is aimed to investigate the effect of serum vascular endothelial growth factor (VEGF) levels on prognosis of hepatocellular carcinoma (HCC) patients receiving radiofrequency ablation (RFA). The 110 HCC patients who received computed tomography (CT) guided RFA were enrolled in this study. The levels of serum VEGF were determined before and after RFA by enzyme-linked immunosorbent assay (ELISA). According to the ELISA results, the patients were divided into the negative group and the positive group. The patient's progression-free survival time was determined. It was demonstrated that the serum VEGF had no significant correlation with ages, sex and tumour size. There were no significant peripheral blood supplies around tumour necrosis. The results showed that higher levels of serum VEGF had a worse prognosis when compared to the patients with lower levels of serum VEGF. The difference between the area under the receiver operating characteristic curve and those when area under curves equalled 0.5 was statistically significant (P < 0.05). The serum VEGF level in liver cancer patients can be used as a prognostic indicator for evaluating the efficacy of RFA treatments.

Improvement of ansamitocin P-3 production by Actinosynnema mirum with fructose as the sole carbon source.

Ansamitocin P-3 (AP-3) is an active and potent anti-tumor maytansinoid, which is usually produced by Actinosynnema spp. In this study, the effects of different carbon sources on biomass and AP-3 production by Actinosynnema mirum were investigated. The results showed great biomass production behavior of A. mirum in glucose medium comparatively to other carbon sources. Interestingly, when fructose was used as the sole carbon source, the highest yield of AP-3 was obtained, which was about fourfold than that of strain cultured in glucose after 168 h. Further analysis conducted in regard to better understanding of such observations in glucose and fructose defined media showed that fructose improves AP-3 production through the stimulation of the key genes of the secondary metabolism pathways. It was concluded that fructose could be a potential carbon source for cost-effective production of AP-3 from an industrial point of view.

Process optimization with alternative carbon sources and modulation of secondary metabolism for enhanced ansamitocin P-3 production in Actinosynnema pretiosum.

Ansamitocin P-3 (AP-3), synthesized by Actinosynnema pretiosum, is a microtubule disruptor with significant antitumor activity. Although efforts have been made for the study of ansamitocin biosynthetic gene clusters and its fermentation improvement, the yield and productivity of AP-3 are still limited. In this study, fructose was found to be more beneficial to AP-3 production than glucose, and the culture condition was optimized via single-factor experiments and response surface method. The AP-3 concentration in the Erlenmeyer flasks reached 144 mg/L with the optimized medium containing fructose 9.36 g/L, glycerol 26.79 g/L and soluble starch 3.03 g/L, increased by ninefold compared with that before optimization. The result of medium optimization showed that fructose was an important element for effective increase in AP-3 production. Transcription of genes involved in primary metabolism and ansamitocin biosynthetic pathway was investigated to elucidate metabolic responses of cell metabolism to the substitution of fructose for glucose. It was demonstrated that using fructose as the major carbon source could relieve glucose repression and therefore result in flux rearrangement in primary metabolism for better providing biosynthetic precursors and stimulating the secondary metabolism in A. pretiosum. The results obtained might be of particular benefit to further enhancement of ansamitocin productivity.