SIRT7 knockdown promotes gemcitabine sensitivity of pancreatic cancer cell via upregulation of GLUT3 expression.

Gemcitabine serves as a first-line chemotherapeutic treatment for pancreatic cancer (PC), but it is prone to rapid drug resistance. Increasing the sensitivity of PC to gemcitabine has long been a focus of research. Fasting interventions may augment the effects of chemotherapy and present new options. SIRT7 is known to link metabolism with various cellular processes through post-translational modifications. We found upregulation of SIRT7 in PC cells is associated with poor prognosis and gemcitabine resistance. Cross-analysis of RNA-seq and ATAC-seq data suggested that GLUT3 might be a downstream target gene of SIRT7. Subsequent investigations demonstrated that SIRT7 directly interacts with the enhancer region of GLUT3 to desuccinylate H3K122. Our group's another study revealed that GLUT3 can transport gemcitabine in breast cancer cells. Here, we found GLUT3 KD reduces the sensitivity of PC cells to gemcitabine, and SIRT7 KD-associated gemcitabine-sensitizing could be reversed by GLUT3 KD. While fasting mimicking induced upregulation of SIRT7 expression in PC cells, knocking down SIRT7 enhanced sensitivity to gemcitabine through upregulating GLUT3 expression. We further confirmed the effect of SIRT7 deficiency on the sensitivity of gemcitabine under fasting conditions using a mouse xenograft model. In summary, our study demonstrates that SIRT7 can regulate GLUT3 expression by binding to its enhancer and altering H3K122 succinylation levels, thus affecting gemcitabine sensitivity in PC cells. Additionally, combining SIRT7 knockdown with fasting may improve the efficacy of gemcitabine. This unveils a novel mechanism by which SIRT7 influences gemcitabine sensitivity in PC and offer innovative strategies for clinical combination therapy with gemcitabine.

Citric Acid Inhibits Cd Absorption and Transportation by Improving the Antagonism of Essential Elements in Rice Organs.

Excessive cadmium (Cd) in rice is a global environmental problem. Therefore, reducing Cd content in rice is of great significance for ensuring food security and human health. A field experiment was conducted to study the effects of foliar application of citric acid (CA) on Cd absorption and transportation in rice under high Cd-contaminated soils (2.04 mg·kg-1). This study revealed that there was a negative correlation between Cd content in vegetative organs and CA content, and that foliar spraying of CA (1 mM and 5 mM) significantly increased CA content and reduced Cd content in vegetative organs. The Cd reduction effect of 5 mM CA was better than that of 1 mM, and 5 mM CA reduced Cd content in grains and spikes by 52% and 37%, respectively. CA significantly increased Mn content in vegetative organs and increased Ca/Mn ratios in spikes, flag leaves, and roots. CA significantly reduced soluble Cd content in vegetative organs and promoted the transformation of Cd into insoluble Cd, thus inhibiting the transport of Cd from vegetative organs to grains. The foliar field application of 1 mM and 5 mM CA could inhibit Cd absorption and transportation by reducing Cd bioactivity and increasing the antagonistic of essential elements in rice vegetative organs. These results provide technical support and a theoretical basis for solving the problem of excessive Cd in rice.

[SPARC Overexpression Enhances the Sensitivity of SKM-1 Cells to Ara-C by Regulating CPBP/MLKL].

OBJECTIVE: To investigate the effect of SPARC gene overexpression on the chemotherapeutic sensitivity of AML-MDS cell line SKM-1 to Ara-C and to further explore its mechanism. METHODS: Subjects were divided into 6 groups: SKM-1 cells (Control), Negative control (LV-NC), SPARC overexpression (LV-SPARC), SKM-1 cells+30 ng/ml Ara-C (30 ng/ml Ara-C), LV-NC+30 ng/ml Ara-C and LV-SPARC+30 ng/ml Ara-C. Cell activity was detected by CCK-8 assay, cell cycle distribution and apoptosis were detected by flow cytometry, mRNA expression levels of SPARC, CPBP and MLKL were detected by RT-qPCR, and the expression levels of related protein were detected by Western blot. RESULTS: After co-treatment with SPARC overexpression and Ara-C, the cell viability decreased and apoptosis increased significantly, with obvious up-regulation of Bax and down-regulation of BCL-2 (P<0.05). Compared with the control group, the cell cycle of LV-SPARC+30 ng/ml Ara-C group was significantly arrested in S phase with obvious down-regulation of CDK2 and up-regulation of p27KIP1 (P<0.05). Compared with LV-SPARC group and 30 ng/ml Ara-C group, the mRNA and protein expression levels of CPBP and MLKL (p-MLKL) were significantly elevated in LV-SPARC+30 ng/ml Ara-C group (P<0.05). In addition, after co-treatment with SPARC overexpression and Ara-C, the protein expression level of p-AKT decreased and the protein expression level of p53 increased (P<0.05). CONCLUSION: SPARC overexpression enhanced the sensitivity of SKM-1 cells to Ara-C and promoted cell cycle arrest and apoptosis, the mechanism of which may be related to the regulation of CPBP/MLKL pathway.

Network Pharmacology and Experimental Validation Reveal the Effects of Chidamide Combined With Aspirin on Acute Myeloid Leukemia-Myelodysplastic Syndrome Cells Through PI3K/AKT Pathway.

Chidamide (CDM), a novel histone deacetylase inhibitor, is currently used for patients with peripheral T-cell lymphoma. Aspirin (ASA), an anti-inflammatory drug, has been shown to exert anticancer activity. Herein, we investigated the effect of CDM combined with ASA on myelodysplastic syndromes-derived acute myeloid leukemia (AML-MDS) cells and explored the underlying mechanism. The putative targets of CDM and ASA were predicted by network pharmacology approach. GO functional and KEGG pathway enrichment analyses were performed by DAVID. Furthermore, experimental validation was conducted by Cell Counting Kit-8 assay, Flow cytometry and Western blotting. Network pharmacology analysis revealed 36 AML-MDS-related overlapping genes that were targets of CDM and ASA, while 10 hub genes were identified by the plug-in cytoHubba in Cytoscape. Pathway enrichment analysis indicated CDM and ASA significantly affected PI3K/AKT signaling pathway. Functional experiments demonstrated that the combination of CDM and ASA had a remarkable synergistic anti-proliferative effect by blocking the cell cycle in G0/G1 phase and inducing apoptosis. Mechanistically, the combination treatment significantly down-regulated the phosphorylation levels of PI3K and AKT. In addition, insulin-like growth factor 1 (IGF-1), an activator of PI3K/AKT pathway, reversed the effects of the combination treatment. Our findings suggested that CDM combined with ASA exerted a synergetic inhibitory effect on cell growth by inactivating PI3K/AKT pathway, which might pave the way for effective treatments of AML-MDS.

Chidamide Inhibits Cell Proliferation via the PI3K/AKT Pathway in K562 Cells Based on Network Pharmacology and Experimental Validation.

BACKGROUND: Chidamide, a novel benzamide-type histone deacetylase (HDAC) inhibitor, exerts antitumor effects on several types of cancer. However, the role of Chidamide in chronic myeloid leukemia (CML) remains elusive. Therefore, the present study aimed to investigate the effects of Chidamide on CML cell proliferation and explore its underlying mechanism. METHODS: Cell proliferation was assessed by CCK-8 assay, cell cycle distribution and apoptosis were detected by flow cytometry and the expression of related proteins was evaluated by western blot analysis. The potential mechanisms were systematically explored by the network-based pharmacological methods, including Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. RESULTS: The results revealed that Chidamide inhibited the proliferation of K562 cells in a dose- and time-dependent manner. In addition, Chidamide blocked cells in the G0/G1 phase via downregulating cyclin-dependent kinase 4, and induced apoptosis via upregulating Bax and downregulating of Bcl-2. Additionally, using network- based pharmacological methods, we found that PI3K/AKT signaling pathway is involved and significantly related to cell proliferation in CML. Intriguingly, cell treatment with Chidamide suppressed the activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway via decreasing the levels of phosphorylated (p)-PI3K and p-AKT. Moreover, insulin-like growth factor 1 (IGF-1), a PI3K/AKT activator, reversed the inhibitory effects of Chidamide on K562 cell proliferation. CONCLUSION: The study demonstrated that Chidamide may inhibit the proliferation of K562 cells by promoting cell cycle arrest and apoptosis via suppressing the PI3K/AKT pathway, suggesting that Chidamide could be a promising approach to the treatment of CML.

[Inhibitory Effects of Metformin on Proliferation of SKM-1 Cells and The Related Underlying Mechanisms].

OBJECTIVE: To investigate the effects of metformin on the proliferation of AML-MDS cells (SKM-1 cells) and its related mechanisms. METHODS: CCK-8 was used to test the cell proliferation; Flow cytometry was used to detect the cell apoptosis and cell cycle; Western blot was used to test the expression level of AMPK and cell cycle regulatory proteins. RESULTS: Metformin could inhibit the proliferation of SKM-1 cells, which may be attributed to metformin-induced cell cycle arrest in G0/G1 but not to metformin induced cell apoptosis. The expression levels of G1-related protein CyclinD1 and CDK4 were down-regulated, while the expression levels of P53, P21CIP1 and P27kIP1 were up-regulated. Moreover, the phosphorylation level of AMPK was up-regulated. CONCLUSION: Metformin inhibits the proliferation of SKM-1 cells, which may relate with AMPK-induced cell cycle arrest. However, future studies are necessary to further explore the related mechanisms.

HSPG2 overexpression independently predicts poor survival in patients with acute myeloid leukemia.

Heparan sulfate proteoglycan 2 (HSPG2), also known as perlecan, is a large multi-domain extracellular matrix proteoglycan, which contributes to the invasion, metastasis and angiogenesis of solid tumor. However, very little is known about the effect of HSPG2 on acute myeloid leukemia (AML). This study aims to investigate the prognostic value of the HSPG2 gene in terms of overall survival and leukemia-free survival in patients with AML. Bone marrow mononuclear cells (BMMCs) from 4 AML patients and 3 healthy controls were processed for RNA-Sequencing (RNA-seq). The mRNA expression level of HSPG2 in BMMCs and CD34+ hematopoietic stem/progenitor cells (HSPC) obtained from enrolled participants and human leukemic cell lines was detected by RT-qPCR. Then the correlations between the expression of HSPG2 and a variety of important clinical parameters, such as median white blood cell (WBC) count and bone marrow (BM) blasts, were further analyzed. The expression level of HSPG2 was significantly upregulated in AML patients at the time of diagnosis, downregulated after complete remission and then elevated again at relapse. Moreover, HSPG2 expression was associated with median WBC count (P < 0.001), median hemoglobin (P = 0.02), median platelet count (P = 0.001), and BM blasts (P < 0.001) in AML patients. Patients with high HSPG2 expression had both worse overall survival (OS) (P = 0.001) and poorer leukemia-free survival (LFS) (P = 0.047). In the multivariate analysis model, HSPG2 was identified as an independent prognostic biomarker of AML. Taken together, these results indicate that HSPG2 overexpression was associated with poor prognosis in AML patients, and may be a prognostic biomarker and therapeutic target of AML.

Metformin inhibits cell proliferation in SKM-1 cells via AMPK-mediated cell cycle arrest.

Metformin, a widely used antidiabetic drug, has previously been demonstrated to exert anti-cancer effects in certain hematological malignancies, but its effects on the transformation of myelodysplastic syndromes to acute myeloid leukemia (AML-MDS) remain unclear. The present study aimed to investigate the effects of metformin on SKM-1 cells (an AML-MDS cell line) and its underlying mechanisms. SKM-1 cells were treated with different concentrations of metformin. Cell proliferation was assayed by CCK-8. Apoptosis and cell cycle phases were detected by flow cytometry, while cell cycle related proteins and AMPK were tested by Western blot. SKM-1 cells were transfected with LV-AMPKα1-RNAi to reduce the expression of AMPK. Metformin inhibited cell proliferation in a dose and time dependent manner by inducing G0/G1 phase arrest rather than apoptosis induction. Metformin promoted the expression of p-AMPK, P53, P21CIP1 and P27KIP1, while inhibited the expression of CDK4 and CyclinD1. AMPK knockdown attenuated the effects of metformin on SKM-1 cells. These findings suggested that metformin inhibited proliferation of SKM-1 cells, potentially through an AMPK-mediated cell cycle arrest.

Prognostic value of DNMT3A mutations in myelodysplastic syndromes: a meta-analysis.

Objectives: Although DNA (cytosine-5)-methyltransferase 3 alpha (DNMT3A) gene mutations have been widely reported in myelodysplastic syndromes (MDS), the prognostic significance of DNMT3A mutations is still controversial. In this study, we conducted a meta-analysis to determine the prognostic effect of DNMT3A mutations in patients with MDS. Methods: Eligible studies from PubMed, Embase, Web of Science, Clinical Trials and the Cochrane Library were searched. Hazard ratios (HRs) and their 95% confidence intervals (CIs) for overall survival (OS) and leukemia-free survival (LFS) were pooled to assess the effect of DNMT3A mutations on the prognosis in MDS patients. Results: A total of 12 studies with 2236 patients were included in this meta-analysis. The pooled HRs for OS and LFS revealed that MDS patients with DNMT3A mutations had a significantly poor prognosis as compared with those without mutations (OS: HR = 1.654, 95% CI = 1.387-1.973, p < 0.001; LFS: HR = 4.624, 95% CI = 3.121-6.851, p < 0.001). Discussion and Conclusion: This meta-analysis showed an adverse prognostic effect of DNMT3A mutations in patients with MDS, which will contribute to risk stratification and prognostic assessment in the disease.

Clinical characteristics of young adult cataract patients: a 10-year retrospective study of the Zhongshan Ophthalmic Center.

AIM: To investigate the characteristics of young adult cataract (YAC) patients over a 10-year period. METHODS: This observational study included YAC patients aged 18-49 years who were treated surgically for the first time at the Zhongshan Ophthalmic Center in China. YAC patients were analysed and compared with patients with childhood cataract (CC) in January 2005 to December 2014. RESULTS: During the 10-year period, 515 YAC patients and 2421 inpatients with CC were enrolled. Among the YAC patients, 76.76% (109/142) of unilateral patients had a corrected distance visual acuity (CDVA) better than 20/40 in the healthy eye, whereas only 20.38% (76/373) of bilateral patients had a CDVA better than 20/40 in the eye with better visual acuity. Compared with the CC group, the YAC group had a higher proportion of rural patients (40.40% vs 31.60%, p=0.001). Furthermore, the prevalence of other ocular abnormalities in YAC patients was higher than that in patients with CC (29.71% vs 17.47%, p<0.001). CONCLUSIONS: A large proportion coming from rural areas and a high prevalence of complicated ocular abnormalities may be the most salient characteristics of YAC patients. Strengthening the counselling and screening strategy for cataract and health education for young adults are required especially for those in rural areas.

Height, weight and body mass index of children with congenital cataracts before surgical treatment.

BACKGROUND: To investigate the distribution of the height, weight and body mass index (BMI) of children with congenital cataracts (CC) before surgical treatment. METHODS: This prospective study included children with CC ≤14 years of age presenting at the Zhongshan Ophthalmic Center from Jan. 2013 to Aug. 2016. The height, weight, and BMI measurements of all participating children were obtained and compared with the World Health Organization Child Growth Reference (WHO Reference), matched by age and gender. The presence of a family history of CC or complicated systemic diseases as well as parental education levels and family income were also recorded. RESULTS: In total, 595 children with CC were included. The mean age was 52.75 ± 33.99 months, and 34.29% (204/595) of them were unilateral cases. Among all of the children, 6.72% (40/595) of cases were complicated by systemic diseases. More than 1/5 (21.01%, 125/595) of the children had a family history of CC and exhibited bilateral involvement. Less than 1/4 (23.2) of the mothers were highly educated, and more than half of the families had a family income below the city average. Height, weight, and BMI measurements of most children with CC were within the normal ranges (±95% CI of the WHO Reference). Compared to the WHO Reference, both girls and boys aged 2-5 years revealed shorter heights, and the girls aged 5-14 years exhibited a shorter height, lower body weight and lower BMI. The heights of the children with CC and systemic diseases were also shorter than the WHO Reference. The children with CC who had a family history of disease had shorter heights and lower BMIs than children with CC but no family history, and the measurements of both groups were lower than the WHO Reference values. CONCLUSIONS: The height, weight and BMI of most of the children with CC in this study were within the normal ranges of the WHO Reference. However, the children with CC and concomitant systemic diseases and those with a family history of CC had shorter heights and lower BMIs. This information aids in our understanding of the physical development of children with CC.

[Effect of vitamine A on mice immune response induced by specific periodontal pathogenic bacteria-immunization].

PURPOSE: The aim of this study was to investigate the effect of vitamine-A deficiency on the induction of specific periodontal pathogenic bacteria A. actinomycetetemcomitans(Aa) immunization. METHODS: BALB/c mice were fed with vitamine A-depleted diet or control regular diet throughout the whole experiment period. After 2 weeks, immunized formalin-killed Aa to build immunized models, 6 weeks later, sacrificed to determine specific antibody-IgG, IgM and sub-class IgG antibody titers in serum, and concentration of IL-10, IFN-γ, TNF-α and RANKL in T cell supernatant were measured by ELISA and T cell proliferation was measured by cintilography. SPSS 11.5 software package was used for statistical analysis. RESULTS: The levels of whole IgG and IgM antibody which were immunized by Aa significantly elevated, non-immune group was unable to produce any antibody. Compared with Aa immunized+RD group, the level of whole IgG in Aa immunized+VAD group was significantly higher (P<0.05); The levels of IgG2a increased obviously, whereas the levels of IgG1 subtype antibody conspicuous decreased, with a significant difference (P<0.05). Aa immunized group could induce body to produce a strong specific T-cell immune response, but Aa immunized+VAD group had a higher T cell proliferate response compared with Aa immunized+RD group, with a statistically significant difference (P<0.05); The expression of RANKL, IFN-γ and TNF-α supernatant increased, while the expression of IL-10 decreased (P<0.05). CONCLUSIONS: The lack of vitamin-A diet can increase the immunized mice's susceptibility to periodontal pathogenic bacteria and trigger or aggravate immune inflammatory response. Adequate vitamin A is an important factor in maintaining body health. Supported by Natural Science Foundation of Liaoning Province (Grant No.20092139) and Science and Technology Program of Shenyang Municipality (Grant No.F10-149-9-32).