目的 构建带Flag标签的人溶质载体家族成员蛋白SLC25A39基因的真核表达载体,在获得Flag?SLC25A39融合蛋白表达后,研究SLC25A39表达对人乳腺癌细胞线粒体稳态的影响.方法 以人乳腺文库为模板采用PCR技术扩增出人SLC25A39的编码区序列,双酶切后将其插入到带Flag标签的pcDNA3.0载体上,转化大肠杆菌DH5α感受态细胞,菌液PCR鉴定阳性的克隆再进行质粒提取,测序正确后将重组质粒与空载体分别转染人乳腺癌细胞ZR75?1.Western印迹鉴定SLC25A39目的基因的表达;Mitotracker对乳腺癌细胞的线粒体进行染色,共聚焦显微镜对线粒体进行观察;Western印迹检测线粒体融合蛋白1(Mfn1)、线粒体分裂蛋白1(Fis1)的表达变化.结果 双酶切鉴定表明,Flag?SLC25A39真核表达载体构建成功;Western印迹验证SLC25A39基因表达成功;激光共聚焦显微镜下观察发现SLC25A39过表达的乳腺癌ZR75?1细胞分裂的线粒体较多;Western印迹证实SLC25A39基因过表达后线粒体分裂蛋白Fis1表达增高,线粒体融合蛋白Mfn1表达减弱.结论 成功构建带Flag标签的SLC25A39基因真核表达载体,该基因可促进人乳腺癌细胞的线粒体分裂,有望成为靶向线粒体治疗乳腺癌的潜在新靶点.

Phosphoglycerate kinase 1 (PGK1), a critical component of the glycolytic pathway, relates to the development of various cancers. However, the mechanisms of PGK1 inhibition and physiological significance of PGK1 inhibitors in cancer cells are unclear. Long non-coding RNAs (lncRNAs) play a vital role in tumor growth and progression. Here, we identify a lncRNA LINC00926 that negatively regulates PGK1 expression and predicts good clinical outcome of breast cancer. LINC00926 downregulates PGK1 expression through the enhancement of PGK1 ubiquitination mediated by E3 ligase STUB1. Moreover, hypoxia inhibits LINC00926 expression and activates PGK1 expression largely through FOXO3A. FOXO3A/LINC00926/PGK1 axis regulates breast cancer glycolysis, tumor growth, and lung metastasis both in vitro and in vivo. In breast cancer patients, LINC00926 expression is negatively correlated with PGK1 and positively correlated with FOXO3A expression. Our work established FOXO3A/LINC00926/PGK1 as a critical axis to regulate breast cancer growth and progression. Targeting PGK1 or supplement of LINC00926 or FOXO3A could be potential therapeutic strategies in breast cancer.

BACKGROUND AND AIMS:Oxaliplatin (OXA) is one of the most common chemotherapeutics in advanced hepatocellular carcinoma (HCC), the resistance of which poses a big challenge. Long noncoding RNAs (lncRNAs) play vital roles in chemoresistance. Therefore, elucidating the underlying mechanisms and identifying predictive lncRNAs for OXA resistance is needed urgently.METHODS:RNA sequencing (RNA-seq) and fluorescence in situ hybridization (FISH) were used to investigate the OXA-resistant (OXA-R) lncRNAs. Survival analysis was performed to determine the clinical significance of homo sapiens long intergenic non-protein-coding RNA 1134 (LINC01134) and p62 expression. Luciferase, RNA immunoprecipitation (RIP), chromatin immunoprecipitation (ChIP), and chromatin isolation by RNA purification (ChIRP) assays were used to explore the mechanisms by which LINC01134 regulates p62 expression. The effects of LINC01134/SP1/p62 axis on OXA resistance were evaluated using cell viability, apoptosis, and mitochondrial function and morphology analysis. Xenografts were used to estimate the in vivo regulation of OXA resistance by LINC01134/SP1/p62 axis. ChIP, cell viability, and xenograft assays were used to identify the demethylase for LINC01134 up-regulation in OXA resistance.RESULTS:LINC01134 was identified as one of the most up-regulated lncRNAs in OXA-R cells. Higher LINC01134 expression predicted poorer OXA therapeutic efficacy. LINC01134 activates anti-oxidative pathway through p62 by recruiting transcription factor SP1 to the p62 promoter. The LINC01134/SP1/p62 axis regulates OXA resistance by altering cell viability, apoptosis, and mitochondrial homeostasis both in vitro and in vivo. Furthermore, the demethylase, lysine specific demethylase 1 (LSD1) was responsible for LINC01134 up-regulation in OXA-R cells. In patients with HCC, LINC01134 expression was positively correlated with p62 and LSD1 expressions, whereas SP1 expression positively correlated with p62 expression.CONCLUSIONS:LSD1/LINC01134/SP1/p62 axis is critical for OXA resistance in HCC. Evaluating LINC01134 expression in HCC will be effective in predicting OXA efficacy. In treatment-naive patients, targeting the LINC01134/SP1/p62 axis may be a promising strategy to overcome OXA chemoresistance.

Lactate dehydrogenase A (LDHA), a critical component of the glycolytic pathway, relates to the development of various cancers, including thyroid cancer. However, the regulatory mechanism of LDHA inhibition and the physiological significance of the LDHA inhibitors in papillary thyroid cancer (PTC) are unknown. Long non-coding RNA (lncRNA) plays a vital role in tumor growth and progression. Here, we identified a novel lncRNA LINC00671 negatively correlated with LDHA, downregulating LDHA expression and predicting good clinical outcome in thyroid cancer. Moreover, hypoxia inhibits LINC00671 expression and activates LDHA expression largely through transcriptional factor STAT3. STAT3/LINC00671/LDHA axis regulates thyroid cancer glycolysis, growth, and lung metastasis both in vitro and in vivo. In thyroid cancer patients, LINC00671 expression is negatively correlated with LDHA and STAT3 expression. Our work established STAT3/LINC00671/LDHA as a critical axis to regulate PTC growth and progression. Inhibition of LDHA or STAT3 or supplement of LINC00671 could be potential therapeutic strategies in thyroid cancer.

目的 构建带Flag标签的肾小管间质性肾炎抗原样蛋白1(Tinagl1)基因真核表达载体,检测其对肝癌细胞HepG2 ERK/AKT磷酸化、生长和迁移的影响.方法 以人乳腺cDNA文库为模板,PCR扩增Tinagl1基因片段,将其插入pcDNA3.0载体,经双酶切和测序验证后,将重组质粒转染到肝癌HepG2细胞中,采用Western印迹检测重组蛋白对ERK和AKT磷酸化水平的影响,生长曲线和划痕实验检测其对肝癌细胞HepG2生长和迁移的影响.结果 双酶切和Western印迹结果表明,pcDNA3.0-Flag-Tinagl1真核表达质粒构建成功,Tinagl1可降低ERK和AKT的磷酸化水平;生长曲线和划痕实验表明Tinagl1抑制肝癌细胞HepG2生长和迁移.结论 构建了带Flag标签的Tinagl1真核表达载体,并能抑制肝癌细胞HepG2中ERK/AKT磷酸化、生长和迁移,为进一步研究Tinagl1在肝癌细胞中的功能奠定了基础.

BACKGROUND:Renal cell cancer (RCC) is one of the most lethal malignancies of the kidney in adults. mTOR (mammalian target of rapamycin) signaling pathway plays a pivotal role in RCC tumorigenesis and progression and inhibitors targeting the mTOR pathway have been widely used in advanced RCC treatment. Therefore, it is of great significance to explore the potential regulators of the mTOR pathway as RCC therapeutic targets.MATERIALS AND METHODS:Bioinformatics analysis was used to screen out the most significant differentially expressed genes in the RCC dataset of The Cancer Genome Atlas (TCGA). Real-time PCR and Western-blot analysis were utilized to examine the expression of inositol-1,4,5-trisphosphate-3-kinase-A (ITPKA) in four RCC cell lines and one human embryonic kidney cell line. Cell counting Kit-8 and colony formation assay were performed to estimate the effect of ITPKA on the proliferation ability of RCC cells. Wound healing and Transwell assays were used to test the effect of ITPKA on RCC cell migration and invasion. Xenograft formation assay was performed in nude mice to investigate the effect of ITPKA in vivo. mTORC1 pathway inhibitor was added to explore the mechanisms by which ITPKA regulates RCC cell growth and progression.RESULTS:Based on bioinformatics analysis, ITPKA is screened out as one of the most significant differentially expressed genes in RCC. ITPKA is upregulated and positively correlated with RCC malignancy and poorer prognosis. ITPKA promotes RCC growth, migration and invasion in cultured cells, and accelerates tumor growth in nude mice. Mechanistically, ITPKA stimulates the mTORC1 signaling pathway which is a requirement for ITPKA modulation of RCC cell proliferation, migration and invasion.CONCLUSION:Our data demonstrate a critical regulatory role of the ITPKA in RCC and suggest that ITPKA/mTORC1 axis may be a promising target for diagnosis and treatment of RCC.

1Department of Infectious Disease, Army No.82 Group Military Hospital, Baoding, People’s Republic of China; 2Department of Cellular Engineering Lab, Beijing Institute of Biotechnology, Beijing, People’s Republic of China; 3Department of Oncology, Second Medical Center of Chinese PLA General Hospital, Beijing, People’s Republic of China; 4Department of Radiation Oncology, Xijing Hospital, Air Force Medical University, Xi’an, Shaanxi, People’s Republic of China; 5Department of Urology, Beijing Luhe Hospital, Capital Medical University, Beijing, People’s Republic of China

目的 构建人AP2β基因慢病毒(lentivirus)表达载体,并检测其过表达对肝癌细胞HepG2生长的影响.方法 从人乳腺文库中采用PCR技术扩增出人AP2β基因编码序列,并将其插入pCDH载体,获得pCDH-AP2β真核表达载体;将其与包装载体转染293T,包装成Lenti-AP2β慢病毒并测定病毒滴度,感染肝癌HepG2细胞,Western印迹检测病毒载体介导的AP2β蛋白的表达情况,并进行生长曲线实验研究过量表达AP2β对HepG2细胞生长的影响.结果 双酶切和Western印迹表明,pCDH-AP2β真核表达质粒构建成功,包装成滴度为2.5×107 PFU/ml的Lenti-AP2β慢病毒载体;将此慢病毒载体感染HepG2细胞,Western印迹显示,慢病毒载体成功表达AP2β,生长曲线和克隆形成实验结果 表明,AP2β过表达可抑制肝癌细胞HepG2的生长.结论 构建了AP2β的慢病毒表达载体Lenti-AP2β,在HepG2细胞中过量表达AP2β可抑制细胞的生长,该实验为进一步研究AP2β在肝癌中的功能奠定了基础.

目的 通过构建慢病毒介导的靶向AP2β基因短发夹RNA(shRNA)重组质粒,观察AP2β低表达对肝细胞癌(HCC)细胞生物学功能的影响.方法 构建人AP2β慢病毒shRNA质粒,将重组质粒转染至人胚肾293T细胞.AP2βshRNA与4个包装质粒共同转染293T细胞包装成慢病毒后感染HepG2细胞,经嘌呤霉素筛选2周后,收集细胞,通过实时定量PCR(qRT-PCR)及Western印迹检测AP2βshRNA干扰效果;利用CCK-8法和细胞划痕实验检测沉默AP2β对HepG2细胞生长、增殖及侵袭迁移的影响.结果 AP2βshRNA能有效沉默AP2β基因;CCK-8法、细胞划痕实验提示,沉默AP2β可促进HepG2细胞生长、增殖及侵袭迁移.结论 慢病毒介导的AP2β敲减重组质粒构建成功,且沉默AP2β可促进HepG2细胞生长、增殖及侵袭迁移,因此AP2β可能是HCC治疗的一个潜在新靶点.

目的 构建带Flag标签pcDNA3.0载体的沉默信息调节因子2(Sirt2)真核表达载体,验证其表达蛋白与M2型丙酮酸激酶(PKM2)的相互结合.方法 利用聚合酶链反应(PCR)从人乳腺文库中扩增出人Sirt2的CDS编码序列,将扩增出的Sirt2基因片段插入双酶切后pcDNA3.0-Flag载体上,转化大肠杆菌感受态细胞DH5α后提取质粒,验证表达,测序正确后,分别转染pcDNA3.0-Flag/myc-PKM2和Flag-Sirt2/myc-PKM2共转染至人胚肾细胞(293T),通过免疫共沉淀实验证明Sirt2蛋白表与PKM2蛋白有相互结合.结果 重组质粒Flag-Sirt2的基因序列与目的序列完全一致,Western印迹检测蛋白表达成功;免疫共沉淀实验证实Sirt2蛋白与PKM2蛋白有相互结合.结论 成功构建了Flag-Sirt2真核表达载体,证实Sirt2蛋白与PKM2蛋白有相互结合,为进一步研究Sirt2在糖酵解中发挥的功能提供了基础.