Matrix stiffening related lncRNA SNHG8 regulates chemosensitivity of ovarian cancer / 生物医学工程学杂志

Extracellular matrix (ECM) has been implicated in tumor progress and chemosensitivity. Ovarian cancer brings a great threat to the health of women with a significant feature of high mortality and poor prognosis. However, the potential significance of matrix stiffness in the pattern of long non-coding RNAs (lncRNAs) expression and ovarian cancer drug sensitivity is still largely unkown. Here, based on RNA-seq data of ovarian cancer cell cultured on substrates with different stiffness, we found that a great amount of lncRNAs were upregulated in stiff group, whereas SNHG8 was significantly downregulated, which was further verified in ovarian cancer cells cultured on polydimethylsiloxane (PDMS) hydrogel. Knockdown of SNHG8 led to an impaired efficiency of homologous repair, and decreased cellular sensitivity to both etoposide and cisplatin. Meanwhile, the results of the GEPIA analysis indicated that the expression of SNHG8 was significantly decreased in ovarian cancer tissues, which was negatively correlated with the overall survival of patients with ovarian cancer. In conclusion, matrix stiffening related lncRNA SNHG8 is closely related to chemosensitivity and prognosis of ovarian cancer, which might be a novel molecular marker for chemotherapy drug instruction and prognosis prediction.

Correlation of OCTN2 with the chemosensitivity of prostate cancer cells to oxaliplatin / 中国药房

OBJECTIVE To study the correlation of novel organic cation transporter 2 （OCTN2） with the chemosensitivity of prostate cancer cells to oxaliplatin. METHODS Tumor samples of patients receiving radical prostatectomy were collected， and OCTN2 protein was detected with immunohistochemistry； the primary cells of the specimen were cultivated to obtain prostate cancer cell line. Inductively coupled plasma mass spectrometry was used to detect the uptake of low concentration （0.1 μmol/L） of oxaliplatin by cancer cells. Real-time PCR and Western blot were used to detect the mRNA and protein expressions of OCTN2 in cancer cells； the prostate cancer cells with the highest and lowest expression of OCTN2 protein were selected， and IC50 of oxaliplatin to prostate cancer cells was analyzed by ATP-TCA method. The inhibitory rate of plasma peak concentration of oxaliplatin （50 μmol/L） to prostate cancer cells was detected by MTT assay. Spearman method was used to analyze the relationship of the uptake of oxaliplatin by prostate cancer cells with inhibitory rate of oxaliplatin to prostate cancer cells and 505916443@qq.com mRNA expressions of OCTN2. RESULTS OCTN2 was located on the membrane of cancer cells， and the uptake of zjdtztougao@163.com oxaliplatin by cancer cells was 0.283±0.264 （n＝12）mRNA and protein expression of OCTN2 varied significantly among different cancer cells. The sensitivity of cancer cells with high expression of OCTN2 to oxaliplatin （IC50 of 4.61 μmol/L） was higher than that of cancer cells with lower expression of OCTN2 （IC50 of 26.23 μmol/L）. The inhibitory rate of oxaliplatin to cancer cells was （25.4±10.8）% （n＝12）. There was a correlation between the uptake of oxaliplatin by prostate cancer cells and the inhibition rate of oxaliplatin to prostate cancer cells and mRNA expression of OCTN2 （P＜0.05）. CONCLUSIONS High-expressed OCTN2 may promote the uptake of oxaliplatin by prostate cancer cells， and its expression can serve as a reference for predicting the sensitivity of prostate cancer cells to oxaliplatin chemotherapy.

FOXO1-miR-506 axis promotes chemosensitivity to temozolomide and suppresses invasiveness in glioblastoma through a feedback loop of FOXO1/miR-506/ETS1/FOXO1 / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

To explore the role of forkhead box protein O1 (FOXO1) in the progression of glioblastoma multiforme (GBM) and related drug resistance, we deciphered the roles of FOXO1 and miR-506 in proliferation, apoptosis, migration, invasion, autophagy, and temozolomide (TMZ) sensitivity in the U251 cell line using in vitro and in vivo experiments. Cell viability was tested by a cell counting kit-8 (CCK8) kit; migration and invasion were checked by the scratching assay; apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and flow cytometry. The construction of plasmids and dual-luciferase reporter experiment were carried out to find the interaction site between FOXO1 and miR-506. Immunohistochemistry was done to check the protein level in tumors after the in vivo experiment. We found that the FOXO1-miR-506 axis suppresses GBM cell invasion and migration and promotes GBM chemosensitivity to TMZ, which was mediated by autophagy. FOXO1 upregulates miR-506 by binding to its promoter to enhance transcriptional activation. MiR-506 could downregulate E26 transformation-specific 1 (ETS1) expression by targeting its 3'-untranslated region (UTR). Interestingly, ETS1 promoted FOXO1 translocation from the nucleus to the cytosol and further suppressed the FOXO1-miR-506 axis in GBM cells. Consistently, both miR-506 inhibition and ETS1 overexpression could rescue FOXO1 overactivation-mediated TMZ chemosensitivity in mouse models. Our study demonstrated a negative feedback loop of FOXO1/miR-506/ETS1/FOXO1 in GBM in regulating invasiveness and chemosensitivity. Thus, the above axis might be a promising therapeutic target for GBM.

Research of esomeprazole on inhibiting proliferation and chemosensitization of breast cancer cells / 国际外科学杂志

Objective:To investigate the inhibitory effect of esomeprazole on proliferation and chemosensitizing effect of breast cancer cells.Methods:Human MBA-MD-231, MCF-7 breast cancer cell line and human Huh7 liver cancer cell line were cultured by conventional methods; cells were treated with different concentrations of esomeprazole, and CCK8 kit was used to detect the proliferation of different tumor cells after stimulation. Cells were treated with different concentrations of esomeprazole, and the effects of esomeprazole on cell cycle of different cells were analyzed by flow cytometry. Cells were treated with different concentrations of paclitaxel and epirubicin combined with esomeprazole, and CCK8 kit was used to detect the proliferation of different tumor cells after stimulation. Measurement data were expressed as mean ± standard deviation ( ± s), and analysis of variance was used for comparison among multiple groups. Results:CCK8 results showed that esomeprazole could inhibit the proliferation of MBA-MD-231 cells, MCF-7 cells and Huh7 cells in a dose-dependent manner. Flow cytometry results showed that cells in G 0/G 1 phase were significantly increased by esomeprazole treatment. Esomeprazole can enhance the inhibitory effect of paclitaxel and epirubicin on the proliferation of MBA-MD-231 cells and MCF-7 cells, and improve the chemosensitivity. Conclusion:Esomeprazole blocks breast cancer cell MBA-MD-231, MCF-7 and liver cancer cell Huh7 in G 0/G 1 phase, thereby inhibiting cell proliferation. Esomeprazole can enhance the inhibitory effect of chemotherapeutic drugs on the proliferation of MBA-MD-231 and MCF-7 cells.

Preliminary study on polymerized human cord hemoglobin increasing the chemosensitivity of subcutaneous xenografts of breast cancer in nude mice / 中国输血杂志

【Objective】 To investigate the effect of polymerized human cord hemoglobin (PolyCHb) on the chemosensitivity of human breast cancer MCF-7 cell subcutaneous xenografts in nude mice and its mechanism. 【Methods】 The MCF-7 cells in exponential growth phase were collected and made into suspension cells at a density of 5×107 cells/mL.Subsequently, the cells were inoculated subcutaneously in the right limb of 18 BALB/c-nu nude mice with 0.2 mL cells per mouse to establish subcutaneous xenograft.When the tumor volume reached about 100 mm3, they were randomly divided into chemotherapy group: doxorubicin 5 mg·kg-1, once/week; chemotherapy + PolyCHb group: in addition to doxorubicin (chemotherapy group), PolyCHb 600 mg·kg-1, 3 times/week; the control group: normal saline 90 mg·kg-1, once/week; all were injected through tail vein continuously for 4 weeks.From the day of injection (d 0), the tumor volume of each group of nude mice was measured every 3 days, and the tumor growth curves were drawn accordingly.After 38 days, the tumor growth observation was completed.The tumor was removed and weighed to calculate the tumor inhibition rate.HE staining, immunohistochemistry and TUNEL method were used to observe the pathological changes of tumor tissue, detect the expression of HIF-1α, and detect tumor cell apoptosis respectively.The content of reactive oxygen species (ROS) of each group was determined by fluorescence staining. 【Results】 The tumor volume (mm3) of chemotherapy + PolyCHb group, chemotherapy group and the control group at day 38 were 196.35±103.45 vs 316.29±62.88 vs 519.42±177.33 (P<0.05), and the tumor inhibition rate (%) of chemotherapy + PolyCHb treatment group and chemotherapy group was 62.20 vs 39.11, respectively.HE staining and TUNEL detection showed that cell necrosis and apoptosis in the growth area of tumor tissue increased in chemotherapy + PolyCHb group.Immunohistochemistry and fluorescence staining showed that HIF-1α expression in chemotherapy + PolyCHb group decreased and reactive oxygen species (ROS) content increased. 【Conclusion】 PolyCHb increases the chemosensitivity of subcutaneous xenograft in nude mice with breast cancer, and its mechanism may be related to the increase of ROS in tumor tissue and the promotion of tumor cell apoptosis.

Effect of Hypoxia Inducible Factor-1α on Chemosensitivity of B-ALL Cells to Vincristine and Its Mechanism / 中国实验血液学杂志

OBJECTIVE@#To explore the effect of hypoxia on the chemosensitivity of B-acute lymphoblastic leukemia （B-ALL） cells to Vincristine (VCR) and the mechanisms.@*METHODS@#B-ALL cells SUP-B15, Nalm-6 and RS4;11 were selected as the research objects. The cells were divided into the control group and the hypoxia mimic group (CoCl2 pretreatment). The two groups were treated with VCR at different concentrations for 24 hours, CCK-8 was used to detect cell viability, flow cytometry was used to detect cell apoptosis, and Western bolt method was used to detect hypoxia inducible factor (HIF-1α), BAX, Bcl-2 and β-actin protein expression. Quantitative real-time fluorescent PCR (qRT-PCR) was used to detect BAX and β-actin mRNA levels.@*RESULTS@#CoCl2 could simulate hypoxic environment to induce the expression of HIF-1α. The cells SUP-B15 and RS4;11 of the hypoxia mimic group were lower sensitivity to VCR as compared with the control group; the apoptosis rate of the hypoxia mimic group was lower than that of the control group after 80 nmol/L VCR treatment. The expression levels of BAX protein and mRNA in the hypoxia mimic group were lower than those of the control group, and there was no significant difference in the expression levels of Bcl-2 protein between two groups.@*CONCLUSION@#Under hypoxic conditions, HIF-1α may mediate VCR resistance in B-ALL cells by downregulating the pro-apoptotic protein BAX.

Effects of RARS2 on cell proliferation, invasion, migration and chemotherapy resistance of pancreatic cancer / 中华肝胆外科杂志

Objective:To investigate the effects of mitochondrial arginyl-tRNA synthase (RARS2) on cell proliferation, invasion, migration and chemotherapy resistance of pancreatic cancer.Methods:Human pancreatic cancer cell lines AsPC-1 and PANC-1 were divided into negative control group, RARS2 interference group-1, RARS2 interference group-2, RARS2 overexpression control group and RARS2 overexpression group. Cell proliferation and sensitivity to gemcitabine were detected by CCK-8 assay, and cell invasion and migration were detected by Transwell assay. Western blot was used to detect the expression of RARS2 under different concentrations and different times of gemcitabine treatment. Western blot and PCR were used to detect the expression of RARS2 in gemcitabine-resistant AsPC cell.Results:Inhibition of RARS2 expression in AsPC-1 and PANC-1 cells significantly inhibited cell proliferation and enhanced sensitivity of gemcitabine to chemotherapy. Overexpression of RARS2 enhanced cell proliferation and decreased sensitivity to gemcitabine. In AsPC-1 cells, the number of migrated cells (100×) in negative control group, RARS2 interference group-1, RARS2 interference group-2, RARS2 overexpression control group and RARS2 overexpression group were (586.7±37.4) cells/field, (195.7±18.6) cells/field, (237.0±17.1) cells/field, (157.7±19.1) cells/field, (456.0±23.1) cells/field, the number of invasive cells were (87.7±13.2) cells/field, (24.7±6.5) cells/field, (31.7±6.1) cells/field, (29.3±4.5) cells/field, (94.3±9.3) cells/field, respectively. The migration and invasion ability of cells were decreased after the expression of RARS2 was decreased, and the migration and invasion ability of cells were enhanced after the expression of RARS2 was increased. PCR and Western blot assay showed that RARS2 expression in the gemcitabine-resistant AsPC-1 was higher than that in the common cell line. In AsPC-1 cells, the expression of RARS2 increased with increasing gemcitabine concentration and treatment time.Conclusion:RARS2 promotes cell proliferation, invasion, migration and chemoresistance of pancreatic cancer, and expression of RARS2 is positively correlated with gemcitabine concentration and treatment time.

Proton Pump Inhibitors Induce Cell Cycle Arrest and Enhance Chemosensitivity of Gastric Cancer Cells by Inhibiting Cell Cycle-related Genes / 胃肠病学

Background: Several studies have shown that proton pump inhibitors (PPIs) can enhance the sensitivity of gastric cancer (GC) cells to chemotherapy and inhibit tumor proliferation and invasion. Aims: To investigate whether PPI could enhance chemosensitivity by inhibition of cell cycle-related genes in GC cells. Methods: Two human GC cell lines, AGS and HGC27 were treated with pantoprazole in different concentrations, and the cell viability was detected by CCK-8 assay. Transcriptome sequencing combined with KEGG enrichment analysis were used to determine the effect of PPI on cell cycle of GC cells, and the changes of cell cycle and its related genes were validated by flow cytometry, real-time PCR and Western blotting, respectively. Bioinformatics websites were employed to analyze the major differentially expressed cell cycle-related genes in GCs and their relationship with patients' prognosis. After transfection with FOXM1 plasmid or control plasmid, the inhibitory effect of PPI combined with cisplatin on GC cells was determined by CCK-8 assay. Results: PPI inhibited the proliferation of GC cells effectively in vitro. Transcriptome sequencing showed that the expression levels of G2/M phase-related genes, including FOXM1, PLK1, and AURKB were down-regulated in PPI-treated GC cells, and G2/M arrest was suggested by KEGG enrichment analysis. All these changes were proved by flow cytometry, real-time PCR and Western blotting. Bioinformatics analysis revealed that FOXM1, PLK1, and AURKB genes were highly expressed in GCs and correlated with a poor prognosis. The inhibitory effect of PPI combined with cisplatin on GC cells was superior to that of cisplatin alone, but could be partially reversed by overexpression of FOXM1. Conclusions: PPI treatment can induce G2/M arrest in GC cells by inhibiting cell cycle-related genes, and subsequently enhance the sensitivity of GC cells to chemotherapy.

Enhanced Effect of miR-148a Targeting STAT3 on Chemosensitivity of Cervical Cancer HeLa Cells to Cisplatin / 肿瘤防治研究

Objective To investigate the effect of miR-148a on the chemosensitivity of cervical cancer HeLa cells to cisplatin and its related mechanism. Methods Cervical cancer HeLa cells were cultured in vitro and the concentration gradient of cisplatin was set to detect IC20 value. Control group, mimic control group, miR-148a mimic group, inhibitor control group and miR-148a inhibitor group were set up. qRT-PCR was used to detect the expression of miR-148a and STAT3 mRNA after transfection. After 4 μmol/L cisplatin treatment, the proliferation of HeLa cells was detected by MTT assay; the apoptosis and cell cycle distribution were detected by flow cytometry; Western blot was used to detect the protein expression of p-STAT3/STAT3, CyclinD1, Bcl-2, Bax and Cleaved caspase-3. Results The IC20 of cisplatin on HeLa cells was about 4 μmol/L. Compared with the mimic control group, the level of miR-148a in the miR-148a mimic group was significantly increased, and the level of STAT3 mRNA was significantly decreased (P < 0.05). Compared with the inhibitor control group, the level of miR-148a in HeLa cells in miR-148a inhibitor group was significantly decreased, and the level of STAT3 mRNA was significantly increased (P < 0.05). On the basis of cisplatin treatment, compared with the mimic control group, the apoptosis rate, G0/G1 phase cell ratio, the protein levels of Bax and Cleaved caspase-3 were significantly increased in miR-148a mimic group, while OD value, the proportions of cells in S and G2/M phase, the protein levels of p-STAT3/STAT3, CyclinD1, Bcl-2 were significantly decreased (P < 0.05); compared with the inhibitor control group, the above indicators of HeLa cells in miR-148a inhibitor group changed significantly in the opposite direction (P < 0.05). Conclusion MiR-148a could enhance the chemosensitivity of cervical cancer HeLa cells to cisplatin by targetedly inhibiting STAT3.

Coix seed oil enhances the chemosensitivity of colon cancer cells by inducing cell cycle arrest and apoptosis / 中国医师杂志

Objective:To investigate the effect of coix seed oil on chemosensitivity of colon cancer cells.Methods:HT29 cell line was cultured in vitro. Different concentrations of coix seed oil (1, 2, 4, 8 mg/ml) and 30 μg/ml 5-fluorouracil (5-FU) were incubated with HT29 cells for 24 hours to simulate chemotherapy. The cell proliferation inhibition rate, apoptosis rate and cell cycle ratio were measured by methyl thiazolyl tetrazolium (MTT) method and flow cytometry, and the protein expression of cleaved caspase-3 was measured by Western blot. Results:The inhibition rate of cell proliferation in 1, 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 5-FU group and coix oil group, and the inhibition rate in 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 1 mg/ml coix oil + 5-FU group ( P<0.05). The apoptosis rate in 5-FU group, coix oil group and 1, 2, 4, 8 mg/ml coix oil + 5-FU group was higher than that in the blank control group ( P<0.05). The apoptosis rate in 1, 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 5-FU group and coix oil group ( P<0.05). The apoptosis rate of 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that of 1 mg/ml coix oil + 5-FU group ( P<0.05). The expression of cleaved caspase-3 in each group was basically in line with the apoptosis rate of flow cytometry. The percentage of G1/M phase cells in 5-FU group, coix oil group and 1, 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in the blank control, and the percentage of S phase cells was lower comparing with blank control ( P<0.05). Besides, the percentage of G1/M phase cells in 1, 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 5-FU group and coix oil group, and the percentage of S phase cells was significantly lower than that in 5-FU group and coix oil group ( P<0.05). The percentage of G1/M phase cells in 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 1 mg/ml coix oil + 5-FU group, and the percentage of S phase cells was significantly lower than that in 1 mg/ml coix oil + 5-FU group ( P<0.05). Conclusions:Coix seed oil may enhance the chemosensitivity of colon cancer cells by inducing cell cycle arrest and apoptosis.

Effects of LncRNASNHG6 regulating miR-26a/EZH2 on proliferation, apoptosis and chemosensitivity of prostate cancer stem cells / 中华内分泌外科杂志

Objective:To investigate the effects and its mechanism of long non-coding RNA (LncRNA) small nucleolar RNA host gene 6 (SNHG6) on proliferation, apoptosis and chemosensitivity of prostate cancer stem cells.Methods:CD44 + CD24 - tumor stem cells and non-CD44 + CD24 - cells were selected from prostate cancer cell PC-3 by flow separation technology, and the expression level of SNHG6 and microRNA (miR) -26a were detected by real-time fluorescence quantitative PCR. Cell proliferation was detected by 5-bromodeoxyuridine (Br-dU) , the apoptosis was detected by flow cytometry, the chemosensitivity of cells to cisplatin was detected by methyl thiazolyl tetrazolium (MTT) , and Western blot was used to detect the protein expressions of proliferating cell nuclear antigen (Ki-67) , B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) ; moreover, the target relationships of SNHG6, miR-26a and zeste enhancer of zeste homolog 2 (EZH2) were detected by double luciferase reporter gene assay, and Western blot was used to detect the effect of miR-26a analog on EZH2 protein expression. Results:Compared with non-CD44 + CD24 - cells, the expression level of SNHG6 in CD44 + CD24 - cells was significantly higher ( P<0.05) ; compared with NC-siRNA group [ (1.00±0.06) %, (96.85±6.48) %, (0.72±0.06) %, (0.43±0.03) %, (5.32±0.15) %, (0.35±0.03) %], SNHG6 expression level (0.25±0.03) , cell proliferation activity [ (75.36±5.1) %], Ki67 (0.38±0.03) and Bcl-2 protein (0.21±0.02) expression levels in SNHG6-siRNA group were significantly lower, while miR-26a expression level, apoptosis rate [ (13.83±2.36) %] and Bax protein (0.48±0.03) expression level were significantly higher, and the sensitivity of the cells to cisplatin was significantly higher ( P<0.05) ; in addition, miR-26a was the target gene of SNHG6, EZH2 was the target gene of miR-26a, and miR-26a analog could reduce the expression level of EZH2 protein. Conclusions:SNHG6 is up-regulated in prostate cancer stem cells. Interfering SNHG6 expression can inhibit the proliferation of cancer stem cells, promote apoptosis, and enhance the sensitivity of cancer stem cells to cisplatin. The mechanism may be related to the targeting regulation of miR-26a/EZH2 axis.

Suppression of OCT2/MRP2 decreases kidney injury and enhances the chemosensitivity of co-administration of cisplatin and astragaloside IV / 药学学报

Kidney injury and decreased chemosensitivity of tumor cells are obstacles with cisplatin (CDDP) chemotherapy. Down-regulation of the organic cation transporter 2 (OCT2) and multidrug resistance-associated protein 2 (MRP2) is a key means to alleviate CDDP-induced kidney injury and increase chemosensitivity. Astragaloside IV (AS IV) is obtained from the well-known traditional Chinese herb Astragalus membranaceus. This study explored the role of AS IV in preventing kidney injury and enhancing the antitumor effect of CDDP by suppressing OCT2 expression in kidney and MRP2 in tumors. This project was reviewed and approved by the Animal Ethics Committee of the First Hospital of Jilin University. The effects of AS IV on CDDP inhibition of tumor growth and promotion of apoptosis were assessed in Lewis lung tumor (LLC)-bearing mice by H&E and TUNEL staining. Kidney injury was assessed by serum biochemical parameters and H&E staining. We used Western blotting and immunohistochemistry assays to detect OCT2 and MRP2 expression in kidney and tumor. The concentration of CDDP in kidney and tumor was measured by HPLC-MS/MS. AS IV enhanced CDDP chemosensitivity by increasing tumor cell apoptosis and slowing tumor growth, and decreased kidney injury as evidenced by lower blood creatinine (Cr) and blood urea nitrogen (BUN). Co-administration of AS IV suppressed MRP2 overexpression induced by CDDP in tumor tissues and may be an important mechanism for enhancing CDDP chemosensitivity. Moreover, AS IV reduced CDDP-induced kidney injury in mice along with suppression of OCT2 expression in kidney. The concentration of CDDP was increased in tumor but decreased in kidney. In total, AS IV not only enhanced the antitumor effect of CDDP by suppressing MRP2 expression in tumor cells, but also decreased kidney injury induced by CDDP. The results provide new insight into the combined use of a chemotherapy drug and natural ingredients to treat cancer.

Human esophageal fibroblast-derived exosomal miR-21 reduced the cisplatin sensitivity to esophageal carcinoma EC9706 cells

The objective of this study was to investigate the effect of human esophageal fibroblast-derived exosomal miR-21 on cisplatin sensitivity against esophageal squamous EC9706 cells. EC9706 cells were co-cultured indirectly with human esophageal fibroblasts (HEF) or miR-21 mimics transfected-HEF in the transwell system. The exosomes in HEF-culture conditioned medium were extracted by differential ultracentrifugation. EC9706 cells were co-cultured with HEF-derived exosomes directly. The cisplatin sensitivity against EC9706 cells was revealed via half maximal inhibitory concentration (IC50) values using MTT assay. The expressions of miR-21, programmed cell death 4 (PDCD4) mRNA, and gene of phosphate and tension homology deleted on chromosome ten (PTEN) mRNA were determined by qRT-PCR. The changes of the protein level were detected using western blot assay. IC50 values of cisplatin against EC9706 cells were increased after EC9706 cells were co-cultured with either HEF or exosomes derived from miR-21 mimics-transfected HEF. Following the increased level of miR-21, the mRNA expression and protein levels of PTEN and PDCD4 were decreased in EC9706 cells. The cisplatin sensitivity to EC9706 cells was reduced by HEF-derived exosomal miR-21 through targeting PTEN and PDCD4. This study suggested that non-tumor cells in the tumor micro-environment increased the tumor anti-chemotherapy effects through their exosomes.

The Influence of Bcl-3 Expression on Cell Migration and Chemosensitivity of Gastric Cancer Cells via Regulating Hypoxia-Induced Protective Autophagy

PURPOSE: Gastric cancer is a highly metastatic malignant tumor, often characterized by chemoresistance and high mortality. In the present study, we aimed to investigate the role of B-cell lymphoma 3 (Bcl-3) protein on cell migration and chemosensitivity of gastric cancer.MATERIALS AND METHODS: The gastric cancer cell lines, AGS and NCI-N87, were used for the in vitro studies and the in vivo studies were performed using BALB/c nude mice. Western blotting, wound healing assay, Cell Counting Kit-8 assay, immunohistochemistry, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were used to evaluate the role of Bcl-3 in gastric cancer.RESULTS: We found that the protein expression of hypoxia (HYP)-inducible factor-1α and Bcl-3 were markedly upregulated under hypoxic conditions in both AGS and NCI-N87 cells in a time-dependent manner. Interestingly, small interfering RNA-mediated knockdown of Bcl-3 expression affected the migration and chemosensitivity of the gastric cancer cells. AGS and NCI-N87 cells transfected with si-RNA-Bcl-3 (si-Bcl-3) showed significantly reduced migratory ability and increased chemosensitivity to oxaliplatin, 5-fluorouracil, and irinotecan. In addition, si-Bcl-3 restored the autophagy induced by HYP. Further, the protective role of si-Bcl-3 on the gastric cancer cells could be reversed by the autophagy inducer, rapamycin. Importantly, the in vivo xenograft tumor experiments showed similar results.CONCLUSIONS: Our present study reveals that Bcl-3 knockdown inhibits cell migration and chemoresistance of gastric cancer cells through restoring HYP-induced autophagy.

Effect and molecular mechanism of Lin28 on 5-Fu sensitivity of hepatocellular carcinoma HepG2 cells / 中国肿瘤生物治疗杂志

@# Objective: To investigate the effect and mechanism of RNA binding protein Lin28 on the 5-fluorouracil (5-Fu) sensitivity of HepG2 cells. Methods: HepG2 cells were transfected with plasmid pcDNA3.1-Lin28 or si-Lin28 (small interfering RNA of Lin28). qPCR and Western blotting were used to detect the expression of Lin28 in HepG2 cells after transfection. Changes of cell proliferation in transfected cells after 5-Fu treatment was detected by CCK8 assay and the 50% inhibitory concentration (IC50) was calculated. Flow cytometry was used to detect apoptotic rate after 5-Fu treatment and the expression of apoptosis-related protein was assayed by Western blotting. The mRNA expressions of drug-resistant miRNAs (let-7a and let-7b), as well as cancer stem cell markers (Oct4, Nanog and Sox2) after transfection were detected by qPCR. Results: As compared to the HepG2/Vector cells, the mRNA and protein expressions of Lin28 were significantly up-regulated in HepG2/Lin28 cells (P<0.05 or P<0.01). Over-expression of Lin28 significantly suppressed the sensitivity of HepG2 cells to 5-Fu (IC50elevated obviously, P<0.05) and significantly increased cell proliferation while decreased apoptotic rate and expression of apoptotic-related protein caspase-3 (all P<0.01). As compared to si-control group, expression of Lin28 in HepG2/si-Lin28 cells was significantly down-regulated (P<0.01). Lin28 knockdown significantly reduced cell proliferation and IC50 of 5-Fu (all P<0.01) but increased apoptotic rate and expression of apoptosis-related protein (P<0.01). Compared with HepG2/Vector group, expressions of let-7a and let-7b, as well as cancer stem cell markers (Oct4, Nanog and Sox2) were significantly increased in HepG2/Lin28 cells (all P<0.01); while these molecules were significantly decreased in HepG2/si-Lin28 cells as comparing to si-control group (all P<0.01). Conclusion: Lin28 can modulate the chemosensitivity of HepG2 cells by regulating the expression of miRNAs and the formation of cancer stem cells. Targeting Lin28 might be a promising approach to improve the chemotherapy efficacy in HCC.

MiR-142-3p enhances chemosensitivity of breast cancer cells and inhibits autophagy by targeting HMGB1

MiR-142-3p has been reported to act as a tumor suppressor in breast cancer. However, the regulatory effect of miR-142-3p on drug resistance of breast cancer cells and its underlying mechanism remain unknown. Here, we found that miR-142-3p was significantly downregulated in the doxorubicin (DOX)-resistant MCF-7 cell line (MCF-7/DOX). MiR-142-3p overexpression increased DOX sensitivity and enhanced DOX-induced apoptosis in breast cancer cells. High-mobility group box 1 (HMGB1) is a direct functional target of miR-142-3p in breast cancer cells and miR-142-3p negatively regulated HMGB1 expression. Moreover, overexpression of HMGB1 dramatically reversed the promotion of apoptosis and inhibition of autophagy mediated by miR-142-3p up-regulation. In conclusion, miR-142-3p overexpression may inhibit autophagy and promote the drug sensitivity of breast cancer cells to DOX by targeting HMGB1. The miR-142-3p/HMGB1 axis might be a novel target to regulate the drug resistance of breast cancer patients.

Expression of long non-coding RNA MTHFD2 and its biological role in human glioblastoma / 医学研究生学报

Objective The long non-coding RNA (lncRNA) MTHFD2 gene is expressed differentially in glioblastoma (GBM) and normal brain tissues, but its biological role in tumors, and particularly in GBM, remains unclear. This study aims to investigate the expression of lncRNA MTHFD2 in the GBM tissue and four GBM cell lines, and explore the effect of its down-regulated expression on the biological function of GBM cells. Methods Specimens of GBM and the paracancerous tissue (as normal control) were collected from 9 patients treated by surgical resection in our Department of Neurosurgery between September and December 2017 LV-MTHFD2-shRNA (U251 shRNA and U-87MG shRNA groups) and empty LV-control solution (U251 shRNA and U-87MG control groups) were transfected into the U251 and U-87MG cell lines. The expressions of lncRNA MTHFD2 in the GBM tissue and the GBM cell lines were detected by qRT-PCR, the chemosensitivity and proliferation of the cells after transfection measured by CCK-8 assay, and the changes in the cell migration ability determined by Transwell assay. Results The relative expression of lncRNA MTHFD2 was significantly higher in the GBM than in the normal tissue (5.13 ± 3.96 vs 1.27 ± 0.58, P < 0.05), while that of MTHFD2 was remarkably lower in the U251 shRNA than in the U251 control group (0.05 ± 0.01 vs 1.00 ± 0.00, P < 0.01), and so was that in the U-87MG shRNA than in the U-87MG control (P < 0.05). The number of cells penetrating the Transwell membrane was markedly lower in the U251 shRNA group than in the U251 control (41.4 ± 6.99 vs 125.8 ± 25.27 per field of view, P < 0.01), and so was that in the U-87MG shRNA than in the U-87MG control (P < 0.05). CCK-8 assay showed that, at 4 days after transfection, the A value was significantly decreased in the U251 shRNA and U-87MG shRNA groups as compared with the U251 control and U-87MG control groups (P < 0.05). Cellular drug resistance test manifested remarkably reduced fifty percent inhibitory concentrations (IC50) in the U251 shRNA and U-87MG shRNA groups as compared with the U251 control and U-87MG control groups (P < 0.05). Conclusion DDown-regulation of the expression of lncRNA MTHFD2 can inhibit the proliferation and migration of U251 and U-87MG cells and enhance the chemosensitivity of the cells to temozolomide, which suggests that lncRNA MTHFD2 could be a potential therapeutic target against GBM.

Over-expression of programmed cell death 5 gene enhances chemosensitivity of brain glioma cells to temozolomide / 中国肿瘤生物治疗杂志

@# Objective: To explore the role of tumor suppressor gene programmed cell death 5 gene (PDCD5) in the growth and temozolomide (TMZ) sensitivity of brain glioma cells. Methods:Atotal of 116 patients with cerebral glioma admitted to the Department of Neurosurgery, First Clinical Hospital of Jilin University from January 2009 to December 2014 were enrolled in this study. QPCR, WB and immunohistochemistry method were used to detect the mRNAand protein expressions of PDCD5 in glioma cell lines (U87, U251), U87 cell line with stable PDCD5 expression (U87-PDCD5), glioma cells with si-PDCD5 transfection and primary cerebral glioma tissues, respectively. MTT assay was used to detect the effect of over-expression or knockdown of PDCD5 on the growth and TMZ-sensitivity of glioma cells. The subcutaneous tumor-bearing model of glioma cell line U87 was established in nude mice, and then the experimental mice were randomly divided into control group, TMZ group, PDCD5 group and TMZ+exogenous PDCD5 recombinant expression vector group.After 20 days, the animals were sacrificed by cervical dislocation and the tumor tissue was excised to measure the tumor volume and weigh. The expression of PDCD5 in tumor tissues was detected by qPCR and WB methods, and the effects of PDCD5 combined with TMZ on the growth of gliomas were also analyzed. Results: The relative mRNA and protein expressions of PDCD5 in U87 cells were significantly lower than those in U251 cells (both P<0.05), and the mRNA and protein expressions of PDCD5 in high level glioma tissues were significantly lower than those in low level tissues (all P<0.05). The sensitivity of U87-PDCD5 cells and U251 cells to TMZ was higher than that of U87 cells (all P<0.05). The sensitivity of cells to TMZ in U87-PDCD5-siRNA group and U251siRNA group was significantly lower than that of the control group (both P<0.05). The tumor volume and weigh to fnudemicexenografts were compared,and the results showed control group>TMZ group>PDCD 5group>combined group(allP<0.05);however, the mRNA and protein expressions of PDCD5 in the transplanted tumor tissues of each group showed the opposite trend (all P<0.05). Conclusion: PDCD5 over-expression can enhance the chemosensitivity of braingliomato the chemotherapy drug TMZ, while silencing of PDCD5 expression exertsthe opposite effect.The combination of PDCD5 and TMZ can better inhibit the growth of xenografts in nude mice.

Establishment of an osimertinib-resistant human non-small cell lung cancer cell line and its subsequent sensitivity to themotherapeutic drugs / 实用医学杂志

Objective Establishment of an osimertinib-resistant PC-9/ZDOR cell line of human non-small cell lung cancer (NSCLC) , and exploration of its drug resistance mechanisms and the sensitivity of themotherapeutic drugs. Methods An osimertinib-resistant PC-9/ZDOR cell line was induced by increasing doses of osimertinib to gefitinib-resistant cells PC-9/ZD. Mutation analysis of EGFR genes was performed by NGS. Cell growth was measured by CCK-8 assay and the sensitivity of chemotherapy was determined via analysis of resistance index (RI).The expression of EGFR and its signal transduction protein was determined by western blot. Results (1) An osimertinib-resistant human NSCLC cell line PC-9/ZDOR was successfully established with resistance index of 44. (2) The evidence from NGS data showed the mutation and amplification of EGFR was eliminated in PC-9/ZDOR cells. (3) The data from Western blot showed that the expression of EGFR and its phosphorylated form protein such as P-AKT and P-ERK was significantly decreased in PC-9/ZDOR cells when compared with those in PC-9/ZD cells (P <0.05). (4) The sensitivity of PC-9/ZDOR cell lines to docetaxel, gemcitabine and paclitaxel was significantly higher than that of PC-9/ZD cell lines (P < 0.05) , while the sensitivity of PC-9/ZDOR cell lines to cisplatin and pemetrexed was similar to the one of PC-9/ZD cell lines (P> 0.05). Conclusions The PC-9/ZDOR cell lines is an osimertinibresistant human NSCLC cell line. Elimination of EGFR gene mutation and/or the decrease of protein expressions of EGFR, p-EGFR, p-ERK and p-AKT maybe serve as the mechanisms of acquired resistance to osimertinib. This osimertinib-resistant cell line, PC-9/ZDOR, showed a elevated level of sensitivity to taxanes and gemcitabine.

Predictive value of in vitro methyl thiazolyl tetrazolium assay chemosensitivity test of cytotoxic drug activity in breast cancer / 中国综合临床

Objective To investigate the value of methyl thiazolyl tetrazolium assay ( MTT) in predicting drug sensitivity of breast cancer cells in vitro. Methods From January 2010 to July 2016,one hundred and ninety-two patients with breast cancer who underwent modified radical mastectomy or breast conserving surgery (no preoperative radiotherapy or chemotherapy) in the Shanghai Fengxian District Central Hospital were selected. MTT method was used to determine the inhibitory level and sensitivity of 12 drugs and 3 chemotherapy regimens to primary cultured cancer cells of 192 patients with breast cancer. Results (1) The sensitivity of breast cancer cells to 12 drugs were in sequence from high to low as follows: Paclitaxel (PTX)＞ Epirubicin ( EPI )＞ Cisplatin ( DDP )＞ 5-Fluorouracil ( 5-FU )＞ Mitoxantrone ( MIT )＞Vincristine ( VCR )＞ Pirarubicin ( THP )＞ Isosophosphamide ( IFO )＞ Carboplatin ( CBP )＞Cyclophosphamide ( CTX)＞ Methotrexate ( MTX)＞ Changchun Rui bin ( NVB) . The sensitivity of chemotherapy regimens in the three groups from high to low was docetaxel/doxorubicin/cyclophosphamide (TAC )＞cyclophosphamide/epirubicin/fluorouracil ( CEF )＞cyclophosphamide/methotrexate/fluorouracil (CMF). The sensitivity rates of PTX,EPI and DDP were 54%(104/192),42%(81/192) and 37%(71/192) respectively. (2) The average inhibitory rates of DDP,CBP and MIT in stage III breast cancer was higher than those in stage I and II breast cancer,and the differences were statistically significant ( F＝11. 14,4. 303,3. 182,P＜0. 05). (3) HR-breast cancer is more sensitive than HR+breast cancer,PTX, EPI,THP,MIT in HER-2(+) breast cancer is more sensitive than in HER-2(－) breast cancer. Conclusion As a widely used drug sensitivity test method, MTT assay has a certain reference value for screening sensitive drugs and selecting clinical chemotherapy regimens in neoadjuvant chemotherapy of breast cancer. PTX,EPI and DDP are more sensitive to other breast cancer cells than other drugs. Chemotherapy based on in vitro susceptibility results improves the efficiency of chemotherapy and decreases the proportion of changes in chemotherapy schemes due to inefficiency.