Long non-coding RNA00461 regulates apoptosis in triple-negative breast cancer cells by combining with the proto-oncogene c-Myc / 中华内分泌外科杂志

Objective:To investigate the effect of long non-coding RNA00461 (LINC00461) on apoptosis of triple negative breast cancer cells.Methods:RT-qPCR was used to detect the expression of LINC00461 in normal breast epithelial cells MCF-10A, TNBC cell lines MDA-MB-231 and MDA-MB-468. The apoptosis rate was detected by Annexin V-FITC/PI double staining cell apoptosis kit. Western blot was used to detect apoptosis-associated protein. The localization of LINC00461 in cells was detected by FISH. RNA pulldown and RIP were used to detect the interaction between LINC00461 and c-Myc. The effect of LINC00461 on TNBC apoptosis was verified by subcutaneous tumorigenesis in nude mice.Results:Compared with MCF-10A, LINC00461 expression in MDA-MB-231 and MDA-MB-468 cells was significantly increased. Interference with LINC00461 significantly reduced the expression of LINC00461 and c-Myc protein. Overexpression of LINC00461 significantly decreased the expression level of apoptosis-related protein. Overexpression of LINC00461 significantly reduced the apoptosis rate by 50%-70%, with a statistically significant difference. FISH results showed that LINC00461 was mainly localized in the cytoplasm. RNA pulldown results showed that LINC00461 interacted with c-Myc. RIP results showed that the concentration of LINC00461 in c-Myc group was more than 400%, and the difference was statistically significant. In addition, overexpression of c-Myc reduced the promotion effect of knockdown LINC00461 on the apoptosis rate of 30%-50%. In animal experiments, overexpression of LINC00461 significantly increased tumor volume (50%-80%) and tumor weight (30%-50%) .Conclusion:LINC00461, mainly located in the cytoplasm, regulates the apoptosis of TNBC cells, and its molecular mechanism may be that LINC00461 interacts with c-Myc protein to play an important role in regulating the apoptosis of TNBC cells.

High expression of MYH9 inhibits apoptosis of non-small cell lung cancer cells through activating the AKT/c-Myc pathway / 南方医科大学学报

OBJECTIVE@#To investigate the role of myosin heavy chain 9 (MYH9) in regulation of cell proliferation, apoptosis, and cisplatin sensitivity of non-small cell lung cancer (NSCLC).@*METHODS@#Six NSCLC cell lines (A549, H1299, H1975, SPCA1, H322, and H460) and a normal bronchial epithelial cell line (16HBE) were examined for MYH9 expression using Western blotting. Immunohistochemical staining was used to detect MYH9 expression in a tissue microarray containing 49 NSCLC and 43 adjacent tissue specimens. MYH9 knockout cell models were established in H1299 and H1975 cells using CRISPR/Cas9 technology, and the changes in cell proliferation cell were assessed using cell counting kit-8 (CCK8) and clone formation assays; Western blotting and flow cytometry were used to detect apoptosis of the cell models, and cisplatin sensitivity of the cells was evaluated using IC50 assay. The growth of tumor xenografts derived from NSCLC with or without MYH9 knockout was observed in nude mice.@*RESULTS@#MYH9 expression was significantly upregulated in NSCLC (P < 0.001), and the patients with high MYH9 expression had a significantly shorter survival time (P=0.023). In cultured NSCLC cells, MYH9 knockout obviously inhibited cell proliferation (P < 0.001), promoted cell apoptosis (P < 0.05), and increased their chemosensitivity of cisplatin. In the tumor-bearing mouse models, the NSCLC cells with MYH9 knockout showed a significantly lower growth rate (P < 0.05). Western blotting showed that MYH9 knockout inactivated the AKT/c- Myc axis (P < 0.05) to inhibit the expression of BCL2- like protein 1 (P < 0.05), promoted the expression of BH3- interacting domain death agonist and the apoptosis regulator BAX (P < 0.05), and activated apoptosis-related proteins caspase-3 and caspase-9 (P < 0.05).@*CONCLUSION@#High expression of MYH9 contributes to NSCLC progression by inhibiting cell apoptosis via activating the AKT/c-Myc axis.

The differential effect of AICAR on c-Myc expression and proliferation in specific tumor cell lines / 中国药理学通报

Aim To investigate the effect of AICAR on the expression of the proto-oncogene c-Myc and cell proliferation rates in specific cancer cell lines. Methods The mRNA levels of c-Myc were evaluated using fluorescence-based qRT-PCR to examine the effect of AICAR treatment on c-Myc mRNA expression levels. Western blot was used to evaluate the protein levels of c-Myc following AICAR treatment. RNA interference was employed to determine whether the regulatory effect of AICAR on c-Myc was dependent on AMPK and the downstream metabolic enzymes relating to AICAR. Actinomycin D and cycloheximide were used to assess the effect of AICAR on the stability of cMyc mR-NA and protein. Western blot was used to examine the regulatory effect of AICAR on c-Myc in various cancer cell lines. The MTT assay was used to determine the effect of AICAR on cell viability in these cell lines. Results AICAR significantly up-regulated c-Myc at both mRNA and protein levels. The protein level of c-Myc reached a plateau 12 h after the AICAR treatment. The up-regulatory effect of c-Myc induced by AICAR was not dependent on either the AMPK signaling pathway or the downstream metabolites of AICAR. AICAR could significantly enhance the mRNA stability of c-Myc but did not affect the protein stability. The up-regulation of c-Myc induced by AICAR was cell-type specific. AICAR up-regulated c-Myc in SW1990, 786-0, and A549, while down-regulated c-Myc in HepG2, MCF7, and U20S. In HepG2 cells, AICAR treatment decreased cell viability. However, in SW1990 and A549 cells, AICAR treatment did not lead to any significant difference in cell viability. AICAR decreased the cell viability only when c-Myc was knocked down in SW1990 and A549 cells. Conclusions AICAR directly up-regulates c-Myc expression in an AMPK-independent manner. The up-regulation effect is cell-type dependent. The regulation of c-Myc expression by AICAR is linked to the inhibitory effect of AICAR on tumor cell proliferation.

Prokaryotic expression, polyclonal antibody preparation, spatio-temporal expression profile and functional analysis of c-Myc of Helicoverpa armigera (Lepidoptera: Noctuidae) / 生物工程学报

c-Myc protein encoded by c-Myc (cellular-myelocytomatosis viral oncogene) gene regulates the related gene expression through the Wnt/β-catenin signaling pathway, and has received extensive attention in recent years. The purpose of this study was to express Helicoverpa armigera c-Myc gene (Ha-c-Myc) by using prokaryotic expression system, prepare the polyclonal antibody, examine the spatio-temporal expression profile of Ha-c-Myc, and investigate the possible function of Ha-c-Myc in regulating H. armigera sterol carrier protein-2 (SCP-2) gene expression. The Ha-c-Myc gene was amplified by PCR and cloned into a prokaryotic expression plasmid pET-32a(+). The recombinant plasmid pET-32a-Ha-c-Myc was transformed into Escherichia coli BL21. IPTG was used to induce the expression of the recombinant protein. Protein was purified by Ni2+-NTA column and used to immunize New Zealand rabbits for preparing the polyclonal antibody. The Ha-c-Myc expression levels in different developmental stages (egg, larva, prepupa, pupa, and adult) of H. armigera and different tissues (midgut, fat body, head, and epidermis) of the prepupa were determined by real-time quantitative reverse transcription PCR (qRT-PCR). Ha-c-Myc siRNA was synthesized and transfected into H. armigera Ha cells. The relative mRNA levels of Ha-c-Myc and HaSCP-2 in Ha cells were detected by qRT-PCR. Results showed that the pET-32a-Ha-c-Myc recombinant plasmid was constructed. The soluble Ha-c-Myc protein of about 65 kDa was expressed in E. coli. The polyclonal antibody was prepared. Western blotting analysis suggested that the antibody had high specificity. Enzyme linked immunosorbent assay (ELISA) showed that the titer of the antibody was high. Ha-c-Myc gene expressed at all developmental stages, with high levels in the early and late instars of larva, and the prepupal stage. Tissue expression profiles revealed that Ha-c-Myc expressed in various tissues of prepupa, with high expression level in the midgut, but low levels in the epidermis and fat body. RNAi results showed that the knockdown of Ha-c-Myc expression significantly affected transcription of HaSCP-2, leading to a 50% reduction in HaSCP-2 mRNA expression level. In conclusion, the Ha-c-Myc was expressed through a prokaryotic expression system, and the polyclonal anti-Ha-c-Myc antibody was obtained. Ha-c-Myc may promote the expression of HaSCP-2 and play an important role in the lipid metabolism of H. armigera. These results may facilitate further study on the potential role and function mechanism of Ha-c-Myc in H. armigera and provide experimental data for exploring new targets of green pesticides.

INHBA-AS1 affects ornithine metabolism and EMT process of cervical cancer HeLa cells through c-Myc/SCD pathway / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：探讨抑制素β亚基A反义RNA1（INHBA-AS1）对宫颈癌HeLa细胞EMT和鸟氨酸代谢途径的影响及其机制。方法：体外常规培养HeLa细胞，实验分为10组：对照组、阴性对照（NC）组、sh-INHBA-AS1组、PluriSIn 1[硬脂酰辅酶A去饱和酶（stearyl CoA desaturase，SCD）抑制剂]组、NC+PluriSIn 1组、sh-INHBA-AS1+PluriSIn 1组、10058-F4（c-Myc抑制剂）组、NC+10058-F4组、sh-INHBA-AS1+10058-F4组、sh-INHBA-AS1+OE-c-Myc组。平板克隆实验检测各组细胞的增殖能力，FCM检测各组细胞的凋亡情况，Transwell小室实验检测各组细胞的侵袭、迁移能力，qPCR法检测各组细胞中INHBA-AS1、c-Myc、SCD和EMT相关基因（N-cadherin、TGF-β、ZEB1）mRNA的表达，WB法检测各组细胞中c-Myc、SCD、EMT相关（N-cadherin、TGF-β、ZEB1）、S-腺苷-甲硫氨酸脱羧酶（SAMDC）和亚精胺/精胺N1-乙酰转移酶（SSAT）蛋白的表达，ELISA检测各组细胞上清液中鸟氨酸脱羧酶（ODC）的含量。结果：敲减INHBA-AS1表达使HeLa细胞的增殖、侵袭和迁移能力显著降低（均P<0.05）而细胞凋亡率显著升高（P<0.05），qPCR、WB法检测结果显示，敲减INHBA-AS1均可显著抑制HeLa细胞中c-Myc、SCD、N-cadherin、TGF-β、ZEB1和SAMDC的表达（均P<0.05），而促进SSAT的表达（P<0.05），并降低HeLa细胞上清液中ODC的含量（P<0.05）。与c-Myc抑制剂和SCD抑制剂单独处理相比，其联合敲减INHBA-AS1后上述作用更加显著（均P<0.05）；与sh-INHBA-AS1组相比，进一步过表达c-Myc后HeLa细胞的增殖能力显著升高（P<0.05）、SCD和N-cadherin蛋白表达水平显著升高（P<0.05）、细胞上清液中ODC含量显著升高（P<0.05）。结论：INHBA-AS1可通过c-Myc调控SCD的表达，从而影响HeLa细胞鸟氨酸代谢和EMT进程，进而促进HeLa细胞的增殖、侵袭和迁移能力。

Correlation between expression of Lin28B and C-myc in patients with laryngeal squamous cell carcinoma and clinicopathological features and prognosis / 中南大学学报(医学版)

OBJECTIVES@#Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumor of head and neck. Screening of target genes for malignant tumor therapy is one of the focuses of cancer research, with proto-oncogene and tumor suppressor gene as the breakthrough. It has become an urgent need to find the target gene related to the treatment and prognosis of LSCC.This study aims to explore the role of Lin28B and C-myc in LSCC by detecting the expressions of these two proteins and analyze the correlation between the expression of Lin28B and C-myc and clinicopathological features and prognosis of LSCC.@*METHODS@#We detected the expression of Lin28B and C-myc proteins in 102 specimens of LSCC and 90 specimens of adjacent tissues by immunochemistry, and analyzed the correlation between Lin28B and C-myc protein expressions in LSCC as well as the correlation between the expressions of the two proteins and the clinicopathological features of LSCC. At the same time, the Kaplan-Meier method was used to analyze the relation between Lin28B and C-myc protein levels with the postoperative survival rate of LSCC patients.@*RESULTS@#The protein levels of Lin28B and C-myc in the LSCC tissnes were significantly higher than those in the adjacent tissues (both P<0.05),and there was a positive correlation between the expression of Lin28B and C-myc in LSCC (r＝0.476, P<0.05). The expression of Lin28B protein was closely related to age, lymph node metastasis, clinical stage, tumor size, and pathological differentiation of LSCC patients (all P<0.05). while the expression of C-myc protein was closely related to lymph node metastasis, clinical stage, tumor size, and pathological differentiation of LSCC patients (all P<0.05). A relevant survival analysis showed that in patients with higher level of Lin28B (P＝0.001) or C-myc protein (P<0.001), the postoperative survival rate was relatively low.@*CONCLUSIONS@#Lin28B and C-myc proteins are highly expressed in LSCC with a positive correlation. Furthermore, they are closely related to lymph node metastasis, clinical stage, tumor size, pathological differentiation and prognosis, suggesting that both Lin28B and C-myc might be involved in the occurrence and development of LSCC.

Study on the Biological Function of Abemecilib in Inhibiting the Proliferation, Invasion and Migration of Small Cell Lung Cancer with High c-Myc Expression / 中国肺癌杂志

BACKGROUND@#Small cell lung cancer (SCLC) with high c-Myc expression is prone to relapse and metastasis, leading to extremely low survival rate. Cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor Abemaciclib plays a key role in the treatment of tumors, but the effects and mechanisms on SCLC remain unclear. This study was to analyze the effect and molecular mechanism of Abemaciclib in inhibiting proliferation, migration and invasion of SCLC with high c-Myc expression, with a view to expanding a new direction for reducing the recurrence and metastasis.@*METHODS@#Proteins interacting with CDK4/6 were predicted using the STRING database. The expressions of CDK4/6 and c-Myc in 31 cases of SCLC cancer tissues and paired adjacent normal tissues were analyzed by immunohistochemistry. The effects of Abemaciclib on the proliferation, invasion and migration of SCLC were detected by CCK-8, colony formation assay, Transwell and migration assay. Western blot was used to detect the expressions of CDK4/6 and related transcription factors. Flow cytometry was used to analyze the effects of Abemaciclib on the cell cycle and checkpoint of SCLC.@*RESULTS@#The expression of CDK4/6 was associated with c-Myc by STRING protein interaction network. c-Myc can directly modalize achaete-scute complex homolog 1 (ASCL1), neuronal differentiation 1 (NEUROD1) and Yes-associated protein 1 (YAP1). Moreover, CDK4 and c-Myc regulate the expression of programmed cell death ligand 1 (PD-L1). Immunohistochemistry showed that the expressions of CDK4/6 and c-Myc in cancer tissues were higher than those in adjacent tissues(P<0.0001). CCK-8, colony formation assay, Transwell and migration assay verified that Abemaciclib could effectively inhibit the proliferation, invasion and migration of SBC-2 and H446OE(P<0.0001). Western blot analysis further showed that Abemaciclib not only inhibited CDK4 (P<0.05) and CDK6 (P<0.05), but also affected c-Myc (P<0.05), ASCL1 (P<0.05), NEUROD1 (P<0.05) and YAP1 (P<0.05), which are related to SCLC invasion and metastasis. Flow cytometry showed that Abemaciclib not only inhibited the cell cycle progression of SCLC cells (P<0.0001), but also significantly increased PD-L1 expression on SBC-2 (P<0.01) and H446OE (P<0.001).@*CONCLUSIONS@#Abemaciclib significantly inhibits the proliferation, invasion, migration and cell cycle progression of SCLC by inhibiting the expressions of CDK4/6, c-Myc, ASCL1, YAP1 and NEUROD1. Abemaciclib can also increase the expression of PD-L1 in SCLC.

Effects of Decitabine Combined with Anlotinib on Proliferation and Apoptosis of Multiple Myeloma Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the biological effects and its relative mechanism of decitabine combined with anlotinib on multiple myeloma cells.@*METHODS@#The human MM cell lines and primary cells were treated with different concentrations of decitabine, anlotinib, and decitabine+anlotinib, respectively. The cell viability was detected and combination effect was calculated by CCK-8 assay. The apoptosis rate was measured by flow cytometry and the level of c-Myc protein was determined by Western blot.@*RESULTS@#Both decitabine and anlotinib could effectively inhibit the proliferation and induce the apoptosis of MM cell lines NCI-H929 and RPMI-8226. The effect of combined treatment on the inhibition of cell proliferation and induction of apoptosis was stronger than that of single-drug treatment. The combination of the two drugs also showed strong cytotoxicity in primary MM cells. Decitabine and anlotinib could down-regulate the level of c-Myc protein in MM cells and the c-Myc level in the combination group was the lowest.@*CONCLUSION@#Decitabine combined with anlotinib can effectively inhibit the proliferation and induce apoptosis of MM cells, which provides a certain experimental basis for the treatment of human MM.

Cancer Treatment Strategies by Targeting the Oncoprotein c-Myc / 中国生物化学与分子生物学报

c-Myc is a transcription factor involved in the Myc/Max/Mxd signal regulatory network. c-Myc plays important roles in human development and the oncogenesis or progression of different types of tumors. Current studies have shown that c-Myc mutations or expression changes are present in more than 70% of tumors. Therefore, c-Myc-targeted inhibitors might become a new strategy for tumor therapy. Currently, there is no clinical treatment for targeting c-Myc. With the continuous study aiming at the c-Myc targeted clinical application, Omomyc has become a representative c-Myc inhibitor by direct inhibition of c-Myc in tumors, which may be a feasible clinical treatment strategy. Although targeting c-Myc has broad prospects in cancer treatment, direct inhibition of c-Myc still has many risks and challenges. Therefore, in this review, firstly, we will summarize the regulatory network and biological functions of c-Myc in cells. Secondly, the potential significance of targeting c-Myc or its homologues in tumor therapy will be discussed. Additionally, the challenges faced by c-Myc as a potential therapeutic target in clinical application will be summarized. Finally, we will also discuss the advantages and disadvantages of some c-Myc inhibitors that have been discovered to date, such as small molecule inhibitors and protein and peptide inhibitors, therefore providing the theoretical basis for c-Myc targeted clinical therapy in cancer.

Juglone induces proliferation inhibition and apoptosis of cervical cancer cells via promoting c-Myc ubiquitination / 南方医科大学学报

OBJECTIVE@#To observe the expression of c-Myc protein in cervical cancer HeLa cells and explore the effect of juglone on the proliferation and apoptosis of HeLa cells by affecting c-Myc ubiquitination.@*METHODS@#HeLa cells treated with different concentrations (0, 10, 20, or 50 μmol/L) of juglone or with 20 μmol/L juglone for different time lengths were examined for expression of c-Myc protein with Western blotting. The half-life of c-Myc protein was determined using cycloheximide (CHX) and c-Myc protein degradation was detected using coimmunoprecipitation. We also assessed the effects of 20 μmol/L juglone combined with 0, 1.0 or 2.0 μmol/L MG132 (a proteasome inhibitor) on c-Myc expression. The effects of 20 μmol/L juglone on the proliferation and apoptosis of HeLa cells with RNA interference-mediated knockdown of c-Myc were evaluated with MTT assay and flow cytometry.@*RESULTS@#Treatment with juglone significantly lowered c-Myc protein expression in HeLa cells in a concentration-and time-dependent manner (P < 0.05). Juglone obviously shortened the half-life of c-Myc protein, and the addition of MG132 significantly up-regulated the expression level of c-Myc protein (P < 0.05). Juglone treatment also promoted ubiquitination of c-Myc protein in HeLa cells. Compared with the cells transfected with a negative control construct, the cells transfected with si-c-Myc showed significantly decreased proliferation inhibition and a lowered cell rate with early apoptosis after juglone treatment (P < 0.05).@*CONCLUSION@#Juglone inhibits proliferation and promotes apoptosis of HeLa cells by affecting the ubiquitination of c-Myc protein.

Expression Level and Correlation of miR-211, miR-155, C-myc in Acute T Lymphocytic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the expression and correlation of miR-211, miR-155, and C-myc in acute T lymphocytic leukemia (T-ALL), aiming to provide evidence for the diagnosis and treatment.@*METHODS@#A total of 96 T-ALL patients who were diagnosed and treated in People's Hospital of Zhengzhou from June 2014 to June 2017 were selected, and 69 healthy volunteers who had a physical examination were selected as control group in the same period. Real-time fluorescent quantitative PCR (RT-PCR) was used to determine the expression levels of miR-211, miR-155, and C-myc in peripheral blood mononuclear cells in each group. Kaplan-Meier was used to analyze the survival of T-ALL patients and correlation of miR-211, miR-155, and C-myc with prognosis. Pearson correlation analysis was used to evaluate the correlation of miR-211, miR-155, and C-myc with disease risk.@*RESULTS@#The expression levels of miR-211 mRNA, miR-155 mRNA, and C-myc mRNA in T-ALL group were higher than those in the control group (P<0.01), those in non-remission group were higher than those in remission group (P<0.01), and those in high-risk group were also higher than those in low-risk group and intermediate-risk group (P<0.01). The survival time of T-ALL patients with low miR-211 expression was longer than that with high miR-211 expression (P<0.01), that with low miR-155 expression was longer than that with high miR-155 expression (P<0.01), and that with low C-myc expression was also longer than that with high C-myc expression (P<0.01). The high expression of miR-211, miR-155, and C-myc was linearly positively correlated with high risk of disease (r=0.749, 0.781, 0.804).@*CONCLUSION@#The expressions of miR-211, miR-155, and C-myc are up-regulated in T-ALL patients, closely related to prognosis, and linearly positively correlated with disease risk.

c-MYC-mediated TRIB3/P62+ aggresomes accumulation triggers paraptosis upon the combination of everolimus and ginsenoside Rh2

The mammalian target of rapamycin (mTOR) pathway is abnormally activated in lung cancer. However, the anti-lung cancer effect of mTOR inhibitors as monotherapy is modest. Here, we identified that ginsenoside Rh2, an active component of Panax ginseng C. A. Mey., enhanced the anti-cancer effect of the mTOR inhibitor everolimus both in vitro and in vivo. Moreover, ginsenoside Rh2 alleviated the hepatic fat accumulation caused by everolimus in xenograft nude mice models. The combination of everolimus and ginsenoside Rh2 (labeled Eve-Rh2) induced caspase-independent cell death and cytoplasmic vacuolation in lung cancer cells, indicating that Eve-Rh2 prevented tumor progression by triggering paraptosis. Eve-Rh2 up-regulated the expression of c-MYC in cancer cells as well as tumor tissues. The increased c-MYC mediated the accumulation of tribbles homolog 3 (TRIB3)/P62+ aggresomes and consequently triggered paraptosis, bypassing the classical c-MYC/MAX pathway. Our study offers a potential effective and safe strategy for the treatment of lung cancer. Moreover, we have identified a new mechanism of TRIB3/P62+ aggresomes-triggered paraptosis and revealed a unique function of c-MYC.

Effects of MRE11 on Apoptosis and Proliferation of Esophageal Squamous Cancer Cells / 肿瘤防治研究

Objective To investigate the effect of MRE11 on the proliferation and apoptosis of esophageal squamous cancer cells and its molecular mechanism. Methods MRE11 expression was downregulated by MRE11 siRNA transfection in esophageal squamous cancer cells. The AKT agonist SC79 (0, 0.1, 0.5, 1, 1.5, 1.8, 2 μg/ml) were used to treat cells with MRE11 inhibition for 24 h. Overexpression vector pcDNA.3.1-c-myc was constructed and co-transfected cells with MRE11 siRNA. Western blot method was used to detect the protein expressions of MRE11, p-AKT and c-myc in esophageal squamous cancer cells Ec9706 and TE-1. The Annexin-V FITC/PI kit was used to detect the apoptosis of Ec9706 and TE-1 cells; the activity of caspase-3 was detected by the Caspase-3 activity detection kit; the proliferation of Ec9706 and TE-1 cells was tested by the BrdU method. Results The protein expressions of MRE11 in Ec9706 and TE-1 cells were significantly increased, compared with human esophageal epithelial Het-1A cells. After MRE11 siRNA transfection, AKT phosphorylation and the protein expressions of MRE11 and c-myc were significantly decreased in esophageal squamous cancer cells. MRE11 inhibition significantly promoted the apoptosis and caspase-3 activity in Ec9706 and TE-1 cells, while inhibited the proliferation of Ec9706 and TE-1 cells. SC79 (1.5, 1.8 and 2 μg/ml) significantly increased AKT phosphorylation in MRE11-suppressed esophageal squamous cancer cells, and reversed the inhibitory effects of MRE11 inhibition on c-myc protein expression and cell proliferation and the promoting effect on cell apoptosis. Overexpression of c-myc inhibited the inhibitory effect of MRE11 down-regulation on cell proliferation and the promotion on caspase-3 activity. Conclusion MRE11 inhibition could effectively inhibit the proliferation of esophageal squamous cancer cells and promote cell apoptosis by regulating AKT and c-myc.

Expressions of long non-coding RNA CASC11 and proto-oncogene c-myc in colorectal cancer and their correlation with recurrence and metastasis / 肿瘤研究与临床

Objective:To investigate the expressions of long non-coding RNA (lncRNA) CASC11 and proto-oncogene c-myc in colorectal cancer and their correlation with recurrence and metastasis.Methods:The cancer tissues and paracancerous tissues of 90 colorectal cancer patients in Tangshan Union Medical College Hospital of Hebei Province from February 2016 to July 2018 were collected. Normal colon epithelial cell lines CCD841 and colorectal cancer cell lines SW480, SW620, HCT116, HT29, DLD-1 were cultured in vitro. Separated by the average value of relative expression level of CASC11 or c-myc mRNA in cancer tissues, patients were divided into the high expression and low expression of CASC11 or c-myc. The protein expressions of CASC11 and c-myc mRNA and c-myc were detected by using real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) and Western blot. Cell lines with the highest protein expressions of CASC11, c-myc mRNA and c-myc were used to do the subsequent experiments. The association of the expression levels of CASC11 and c-myc mRNA with the clinicopathological features was analyzed. Pearson correlation test was used to analyze the relationship between CASC11 and c-myc mRNA of cancer tissues. JASPAR software was used to analyze whether there were binding sites of CASC11 and c-myc gene. The wild-type and mutant-type CASC11 recombinant plasmids were constructed, and the relationship between c-myc and CASC11 was confirmed by using dual luciferase reporter gene assay. Cell lines with the highest expressions of CASC11 and c-myc were transfected with c-myc interference sequence plasmid (Sh-c-myc group) or the negative control sequence plasmid (Sh-NC group), and the conventional cultured blank control group (NC group). The proliferation of cells was detected by using methyl thiazolyl tetrazolium (MTT) method, the invasion and migration abilities of cells were detected by using Tanswell test, and the protein expressions of CASC11, c-myc mRNA and c-myc in cells of all groups were detected by using qRT-PCR and Western blot.Results:The protein expression levels of CASC11, c-myc mRNA and c-myc protein in cancer tissues were increased compared with those in paracancerous tissues, and the differences were statistically significant (all P < 0.05). Compared with CCD841 cells, the protein expression levels of CASC11, c-myc mRNA and c-myc in all colorectal cancer cell lines were increased, and the differences were statistically significant (all P < 0.05); the highest protein expressions of CASC11, c-myc mRNA and c-myc were found in SW480 cell lines which were used to do the subsequent experiments. Pearson correlation analysis showed that there was a positive correlation between CASC11 mRNA and c-myc mRNA in cancer tissues ( r = 0.494, P < 0.05). The high expression rate of CASC11 and c-myc mRNA in cancer tissues for patients with lymph node metastasis was higher than that for those without lymph node metastasis [73.7% (28/38) vs. 26.9% (14/52), 84.2% (32/38) vs. 23.1% (12/52)], the high expression rate of CASC11 and c-myc mRNA in cancer tissues for patients with TNM stage Ⅲ-Ⅳ was higher than that for those with TNM stage Ⅰ-Ⅱ [76.0% (38/50) vs. 10.0% (4/40), 72.0% (36/50) vs. 20.0% (8/40)], and the differences were statistically significant (all P < 0.05). JASPAR software showed that the binding sites were detected in CASC11 promoter region and c-myc gene; dual luciferase reporter gene assay results showed that the relative activity of SW480 cells co-transfected with Sh-c-myc and wild-type CASC11 plasmid was lower compared with that of SW480 cells co-transfected with Sh-NC and wild-type CASC11 plasmid ( P < 0.05). Compared with NC group and Sh-NC group, the expression level of CASC11 mRNA, the number of invasive and migratory cells of SW480 cells in Sh-c-myc group were decreased, while cell proliferation inhibition rate was increased, and the differences were statistically significant (all P < 0.05). Conclusions:CASC11 and c-myc mRNA are highly expressed in colorectal cancer tissues and cell lines, and binding sites can be detected in CASC11 promoter region and c-myc gene. The expressions of both have a correlation, and the down regulation of c-myc can inhibit the invasion and migration of colorectal cancer cells by inhibiting the expression of CASC11.

Advances in the research on mechanism of tumor metabolism regulated by c-Myc / 中国药科大学学报

@#The transcription factor c-Myc regulates the proliferation, differentiation, metabolism and other key processes of normal cells extensively.The unleashed MYC oncogene frequently produces abundant c-Myc protein, which directly regulates the gene expression of key metabolic enzymes, or tumor-related metabolic pathways by inhibiting microRNA, leading to abnormal metabolism characterized by heightened nutrients uptake, enhanced glycolysis and glutaminolysis, and elevated fatty acid and nucleotide synthesis.This paper briefly summarizes how c-Myc regulated metabolism on glycolysis, glutamine metabolism, tricarboxylic acid cycle, lipid metabolism and nucleotide synthesis in cancer cell,which provides some theoretical reference for the development of antitumor targets and drugs involving c-Myc.

Targeting "undruggable" c-Myc protein by synthetic lethality / 医学前沿

Synthetic lethal screening, which exploits the combination of mutations that result in cell death, is a promising method for identifying novel drug targets. This method provides a new avenue for targeting "undruggable" proteins, such as c-Myc. Here, we revisit current methods used to target c-Myc and discuss the important functional nodes related to c-Myc in non-oncogene addicted network, whose inhibition may cause a catastrophe for tumor cell destiny but not for normal cells. We further discuss strategies to identify these functional nodes in the context of synthetic lethality. We review the progress and shortcomings of this research field and look forward to opportunities offered by synthetic lethal screening to treat tumors potently.

Regulatory effect of annexin A5 on glioma cell invasion andmigration and its mechanisms / 西安交通大学学报(医学版)

【Objective】 To investigate the regulatory effect of annexin A5 on glioma cell invasion and migration and its mechanism. 【Methods】 The expression of annexin A5 in 100 cases of glioma tissues and 20 cases of normal brain tissues was detected by immunohistochemistry. The expression of annexin A5 was downregulated by transfection with siRNA targeting annexin A5 (si-Annexin A5) in human glioma cell line (U251). The expression of annexin A5 was confirmed by RT-PCR and Western blot analysis. The proliferation ability of U251 cells was detected by MTT test and colony formation test, the apoptosis of U251 cells was detected by flow cytometry and Hoechst 33258 staining, and the migration and invasion ability of U251 cells was examined by wound healing test and Matrigel Transwell invasion test. The expressions of Raf, p-Raf, MEK1/2, p-MEK1/2, ERK1/2, p-ERK1/2, c-Myc and E-Cadherin in U251 cells were analyzed by Western blot. 【Results】 Compared with those of normal brain tissues, the mRNA and protein expression levels of Annexin A5 in glioma tissues increased by 2.45 times and 2.87 times, respectively (P<0.05). Pearson correlation analysis showed that with the increase of tumor grade, the positive rate of Annexin A5 gradually increased, and the tumor grade and positive rate were significantly positively correlated (r=1.000, P=0.000). The cell viability of U251 cells in the si-Annexin A5 group after 48 h and 72 h of culture was significantly reduced by 29.46% and 40.43%, respectively, compared with that in the control group (P<0.05). Compared with the control group, in the si-Annexin A5 group the colony formation rate was reduced by 68.58%, while the apoptosis rate was increased by 24.41 times (P<0.05); the cell migration rate and invasion rate were reduced by 65.35% and 68.80% (P<0.05). The protein expression of p-Raf, p-MEK1/2, p-ERK1/2 and c-Myc in the si-Annexin A5 group were significantly reduced by 54.67%, 70.37%, 60.26% and 54.95%, respectively, and that of E-Cadherin was increased by 3.58 times (P<0.05). 【Conclusion】 Downregulation of Annexin A5 inhibits the growth and motility of glioma cells and induces cell apoptosis by inhibiting the Raf/MEK/ERK signaling pathway.

Inhibition of YAP-c-Myc signaling pathway involved effect of ORI on anti-glioma / 中国药理学通报

Aim To investigate the effects of oridonin on proliferation, migration and apoptosis of U87 glioma cells and to explore the involvement of the mechanism in the inhibition of Yes-associated protein (YAP)-c - Myc signaling pathway. Methods The effect of oridonin on U87 viability was measured by MTT assay; the migration and invasiveness of cells were measured by transwell assays; the apoptotic rates of cells were assessed by flow cytometry; the caspase-3, B c l - 2, Bax, YAP, c - MycmRNA expression in U87 glioma cells was detected by real-time quantitative P C R; the caspase-3, Bcl-2, Bax, YAP, p-YAP (Seri 27), c-Myc protein expressions were detected by Western blot. Results The proliferation of U87 cells was significantly inhibited by oridonin in a dose-dependent manner (P < 0. 05), and the ability of cell migration and invasion was weakened (P <0. 01), cell apoptosis rate in flow cytometry analysis increased significantly (P <0. 01), the protein and mRNA expression of caspase-3 increased (P < 0. 05), the mRNA and protein expression of Bcl-2/Bax decreased (P < 0. 05), the mRNA and protein expression of Y A P and c-Myc decreased (P < 0. 05), and the protein expression of p - Y A P increased (P < 0. 05). Conclusions Oridonin can significantly inhibit the proliferation and migration of U87 glioma cells and promote the transformation apoptosis of glioma cells; the mechanism may be related to the inhibition of YAP-c-Myc signaling pathway.

Are stem cell marker expression and cd133 analysis relevant to differentiate colorectal cancer? / A expressão de marcadores de células-tronco e a análise do cd133 são relevantes na diferenciação do câncer colorretal?

ABSTRACT Background: CD133 and AXL have been described as cancer stem cell markers, and c-MYC as a key regulatory cellular mechanism in colorectal cancer (CRC). Aim: Evaluate the prognostic role of the biomarkers CD133, AXL and c-MYC and their association with clinicopathologic characteristics in colorectal adenocarcinomas and adenomas. Methods: A total of 156 patients with UICC stage I-IV adenocarcinomas (n=122) and adenomas (n=34) were analyzed. Tissue microarrays (TMA) from primary tumors and polyps for CD133, c-MYC and AXL expression were performed and analyzed for their significance with clinicopathologic characteristics. Results: Poorly differentiated adenocarcinomas and disease progression were independent risk factors for poor overall survival. The median overall survival time was 30 months. Positive CD133 expression (35.9% of all cases), particularly of right-sided CRCs (44.8% of the CD133+ cases), was negatively correlated with death in the univariate analysis, which did not reach significance in the multivariate analysis. c-MYC (15.4% of all cases) was predominantly expressed in advanced-stage patients with distant (non-pulmonary/non-hepatic) metastasis. AXL expression was found only occasionally, and predominantly dominated in adenomas, with less penetrance in high-grade dysplasia. Conclusions: CD133 expression was not associated with inferior overall survival in CRC. While AXL showed inconclusive results, c-MYC expression in primary CRCs was associated with distant metastasis.

RESUMO Racional: CD133 e AXL são descritos na literatura como marcadores de células-tronco tumorais, e c-MYC cumpre papel chave como mecanismo de regulação celular no câncer colorretal (CCR). Objetivo: Avaliar o papel prognóstico dos biomarcadores CD133, AXL e c-MYC e sua associação com características clinicopatológicas de adenocarcinomas e adenomas colorretais. Métodos: Um total de 156 pacientes com adenocarcinomas de estádio UICC I-IV (n=122) e adenomas (n=34) colorretais foram avaliados. Microarranjos teciduais (TMA) dos tumores primários e adenomas foram realizados em busca de expressão de CD133, c-MYC e AXL, com posterior análise de relação significativa com características clinicopatológicas. Resultados: Adenocarcinomas pobremente diferenciados e progressão de doença foram fatores de risco independentes para má sobrevida global. A taxa mediana de sobrevida global foi de 30 meses. Expressão positiva de CD133 (35,9% dos casos), particularmente em cânceres de cólon direito (44,8% dos casos CD133+), correlacionou-se negativamente com óbito na análise univariada, sem significância estatística na análise multivariada. c-MYC (15,4% dos casos) teve predomínio de expressão em pacientes com estádio avançado com metástases distantes (não-pulmonares/não-hepáticas). Expressão de AXL foi pouco encontrada, com predomínio em adenomas, com menor penetrância em displasia de alto grau. Conclusão: Expressão de CD133 não se associou com sobrevida global inferior em CCR. Enquanto AXL demonstrou resultados inconclusivos, expressão de c-MYC em tumores primários se associou-se à metástases à distância.

De novo double-hit B-cell precursor leukemia/lymphoma - an unusual presentation as peritoneal lymphomatosis

Peritoneal lymphomatosis (PL) is a rare presentation of extranodal precursor leukemia/lymphoma. The presentation is often non-specific, leading to delayed diagnosis and treatment. In this case, though the preliminary diagnosis was established on ascitic fluid cytology, the disease progressed rapidly, leading to demise before initiating chemotherapy. Immunophenotyping and molecular studies, performed later, established a diagnosis of de novo B-cell precursor leukemia/lymphoma with MYC, BCL2 rearrangements (Double-hit lymphoma). MYC, BCL2 rearrangements are rarely reported in precursor B-lymphoma/leukemia which carry dismal prognosis. In this report, we illustrate autopsy findings of PL in an elderly gentleman who presented with ascites for evaluation.