Crosstalk between the nucleotide excision repair and Fanconi anemia/BRCA pathways

Cells have evolved multiple distinct DNA repair pathways to efficiently correct a variety of genotoxic lesions, and decades of study have led to an improved understanding of the mechanisms and regulation of these individual pathways. However, there is now an increasing appreciation that extensive crosstalk exists among DNA repair pathways and that this crosstalk serves to increase the efficiency and diversity of response to damage. The Fanconi anemia (FA)/BRCA and nucleotide excision repair (NER) pathways have been shown to share common factors, and often work in concert to repair damage. Genomic studies are now revealing that many tumors harbor somatic mutations in FA/BRCA or NER genes, which may provide a growth advantage, but which could also be exploited therapeutically.     

RNA interferences targeting the Fanconi anemia/BRCA pathway upstream genes reverse cisplatin resistance in drug-resistant lung cancer cells

Background

Cisplatin is one of the most commonly used chemotherapy agent for lung cancer. The therapeutic efficacy of cisplatin is limited by the development of resistance.In this study, we test the effect of RNA interference (RNAi) targeting Fanconi anemia (FA)/BRCA pathway upstream genes on the sensitivity of cisplatin-sensitive (A549 and SK-MES-1) and -resistant (A549/DDP) lung cancer cells to cisplatin.

Result

Using small interfering RNA (siRNA), knockdown of FANCF, FANCL, or FANCD2 inhibited function of the FA/BRCA pathway in A549, A549/DDP and SK-MES-1 cells, and potentiated sensitivity of the three cells to cisplatin. The extent of proliferation inhibition induced by cisplatin after knockdown of FANCF and/or FANCL in A549/DDP cells was significantly greater than in A549 and SK-MES-1 cells, suggesting that depletion of FANCF and/or FANCL can reverse resistance of cisplatin-resistant lung cancer cells to cisplatin. Furthermore, knockdown of FANCL resulted in higher cisplatin sensitivity and dramatically elevated apoptosis rates compared with knockdown of FANCF in A549/DDP cells, indicating that FANCL play an important role in the repair of cisplatin-induced DNA damage.

Conclusion

Knockdown of FANCF, FANCL, or FANCD2 by RNAi could synergize the effect of cisplatin on suppressing cell proliferation in cisplatin-resistant lung cancer cells through inhibition of FA/BRCA pathway.     

FANCD2, FANCJ and BRCA2 cooperate to promote replication fork recovery independently of the Fanconi Anemia core complex

Fanconi Anemia (FA) is an inherited multi-gene cancer predisposition syndrome that is characterized on the cellular level by a hypersensitivity to DNA interstrand crosslinks (ICLs). To repair these lesions, the FA pathway proteins are thought to act in a linear hierarchy: Following ICL detection, an upstream FA core complex monoubiquitinates the central FA pathway members FANCD2 and FANCI, followed by their recruitment to chromatin. Chromatin-bound monoubiquitinated FANCD2 and FANCI subsequently coordinate DNA repair factors including the downstream FA pathway members FANCJ and FANCD1/BRCA2 to repair the DNA ICL. Importantly, we recently showed that FANCD2 has additional independent roles: it binds chromatin and acts in concert with the BLM helicase complex to promote the restart of aphidicolin (APH)-stalled replication forks, while suppressing the firing of new replication origins. Here, we show that FANCD2 fulfills these roles independently of the FA core complex-mediated monoubiquitination step. Following APH treatment, nonubiquitinated FANCD2 accumulates on chromatin, recruits the BLM complex, and promotes robust replication fork recovery regardless of the absence or presence of a functional FA core complex. In contrast, the downstream FA pathway members FANCJ and BRCA2 share FANCD2''s role in replication fork restart and the suppression of new origin firing. Our results support a non-linear FA pathway model at stalled replication forks, where the nonubiquitinated FANCD2 isoform – in concert with FANCJ and BRCA2 – fulfills a specific function in promoting efficient replication fork recovery independently of the FA core complex.     

FANCD2, FANCJ and BRCA2 cooperate to promote replication fork recovery independently of the Fanconi Anemia core complex

Fanconi Anemia (FA) is an inherited multi-gene cancer predisposition syndrome that is characterized on the cellular level by a hypersensitivity to DNA interstrand crosslinks (ICLs). To repair these lesions, the FA pathway proteins are thought to act in a linear hierarchy: Following ICL detection, an upstream FA core complex monoubiquitinates the central FA pathway members FANCD2 and FANCI, followed by their recruitment to chromatin. Chromatin-bound monoubiquitinated FANCD2 and FANCI subsequently coordinate DNA repair factors including the downstream FA pathway members FANCJ and FANCD1/BRCA2 to repair the DNA ICL. Importantly, we recently showed that FANCD2 has additional independent roles: it binds chromatin and acts in concert with the BLM helicase complex to promote the restart of aphidicolin (APH)-stalled replication forks, while suppressing the firing of new replication origins. Here, we show that FANCD2 fulfills these roles independently of the FA core complex-mediated monoubiquitination step. Following APH treatment, nonubiquitinated FANCD2 accumulates on chromatin, recruits the BLM complex, and promotes robust replication fork recovery regardless of the absence or presence of a functional FA core complex. In contrast, the downstream FA pathway members FANCJ and BRCA2 share FANCD2's role in replication fork restart and the suppression of new origin firing. Our results support a non-linear FA pathway model at stalled replication forks, where the nonubiquitinated FANCD2 isoform – in concert with FANCJ and BRCA2 – fulfills a specific function in promoting efficient replication fork recovery independently of the FA core complex.     

MET inhibition enhances PARP inhibitor efficacy in castration-resistant prostate cancer by suppressing the ATM/ATR and PI3K/AKT pathways

Up to 30% of patients with metastatic castration-resistant prostate cancer (CRPC) patients carry altered DNA damage response genes, enabling the use of poly adenosine diphosphate–ribose polymerase (PARP) inhibitors in advanced CRPC. The proto-oncogene mesenchymal–epithelial transition (MET) is crucial in the migration, proliferation, and invasion of tumour cells. Aberrant expression of MET and its ligand hepatocyte growth factor is associated with drug resistance in cancer therapy. Here, we found that MET was highly expressed in human CRPC tissues and overexpressed in DU145 and PC3 cells in a drug concentration-dependent manner and is closely related to sensitivity to PARP inhibitors. Combining the PARP inhibitor olaparib with the MET inhibitor crizotinib synergistically inhibited CRPC cell growth both in vivo and in vitro. Further analysis of the underlying molecular mechanism underlying the MET suppression-induced drug sensitivity revealed that olaparib and crizotinib could together downregulate the ATM/ATR signaling pathway, inducing apoptosis by inhibiting the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway, enhancing the olaparib-induced antitumour effect in DU145 and PC3 cells. In conclusion, we demonstrated that MET inhibition enhances sensitivity of CRPC to PARP inhibitors by suppressing the ATM/ATR and PI3K/AKT pathways and provides a novel, targeted therapy regimen for CRPC.     

Evaluation of concentration and storage effects of mitomycin C in the diagnosis of Fanconi anemia among idiopatic aplastic anemia patients

BACKGROUND:

Fanconi anemia (FA) is a rare autosomal recessive genetic disorder that shows an increased sensitivity to the intercalating agents such as mytomycin C (MMC), measured as chromosomal aberrations. This study was conducted to differentiate between FA and “idiopathic” aplastic anemia on the basis of induced chromosomal breakage study with MMC.

MATERIALS AND METHODS:

MMC stress tests in different final concentrations of 20 and 50 ng/ml of MMC were conducted on peripheral blood lymphocytes from 32 patients with aplastic anemia and 13 healthy controls. Fifty nanograms per milliliter of MMC from old, fresh and frozen stocks was used to check the sensitivity of diagnosis on FA-diagnosed patients. Statistical analysis was used for the assessment of aberrations, including chromatid and chromosome breaks and exchanges.

RESULTS:

Eight patients (25%) with a very high percentage of chromosomal breakage were diagnosed as FA on the basis of the chromosomal breakage study. Six of these patients exhibited congenital anomalies at presentation, while another two lacked such anomalies or had minor physical problems. Freshly made MMC has shown more sensitivity to detect FA patients compared with frozen or 1-week-old MMC stock.

CONCLUSIONS:

The study indicates that freshly made MMC stress test provides an unequivocal means of differentiation between FA and “idiopathic” aplastic anemia. Further, the study, the first of its kind from Iran, stresses on the need for conducting this test in all aplastic anemia cases, even those without congenital anomalies, for accurate and timely diagnosis of FA to implement appropriate therapy.     

Mutations of the Fanconi Anemia Group A Gene (FAA) in Italian Patients

Fanconi anemia (FA) is an autosomal recessive disease characterized by progressive pancytopenia, congenital malformations, and predisposition to acute myeloid leukemia. At least five complementation groups (FA-A-FA-E) have been identified. The relative prevalence of FA-A has been estimated at an average of approximately 65% but may widely vary according to ethnic background. In Italy, 11 of 12 patients analyzed by cell-fusion studies were assigned to group FA-A, suggesting an unusually high relative prevalence of this FA subtype in patients of Italian ancestry. We have screened the 43 exons of the FAA gene and their flanking intronic sequences in 38 Italian FA patients, using RNA-SSCP. Ten different mutations were detected: three nonsense and one missense substitutions, four putative splice mutations, an insertion, and a duplication. Most of the mutations are expected to cause a premature termination of the FAA protein at various sites throughout the molecule. Four protein variants were also found, three of which were polymorphisms. The missense mutation D1359Y, not found in chromosomes from healthy unrelated individuals, was responsible for a local alteration of hydrophobicity in the FAA protein, and it was likely to be pathogenic. Thus, the mutations so far encountered in the FAA gene are essentially all different. Since screening based on the analysis of single exons by genomic DNA amplification apparently detects only a minority of the mutations, methods designed to detect alterations in the genomic structure of the gene or in the FAA polypeptide may be helpful in the identification of FAA mutations.     

Dynamics of the Artemis and DNA-PKcs Complex in the Repair of Double-Strand Breaks

Pathologic chromosome breaks occur in human dividing cells ～10 times per day, and physiologic breaks occur in each lymphoid cell many additional times per day. Nonhomologous DNA end joining (NHEJ) is the major pathway for the repair of all of these double-strand breaks (DSBs) during most of the cell cycle. Nearly all broken DNA ends require trimming before they can be suitable for joining by ligation. Artemis is the major nuclease for this purpose. Artemis is tightly regulated by one of the largest protein kinases, which tethers Artemis to its surface. This kinase is called DNA-dependent protein kinase catalytic subunit (or DNA-PKcs) because it is only active when it encounters a broken DNA end. With this activation, DNA-PKcs permits the Artemis catalytic domain to enter a large cavity in the center of DNA-PKcs. Given this remarkably tight supervision of Artemis by DNA-PKcs, it is an appropriate time to ask what we know about the Artemis:DNA-PKcs complex, as we integrate recent structural information with the biochemistry of the complex and how this relates to other NHEJ proteins and to V(D)J recombination in the immune system.     

基于CRISPR/Cas9技术的高通量筛选平台:发掘病毒复制相关宿主分子的新途径

病毒作为严格的细胞内寄生生物,需要多种宿主蛋白辅助其完成生命周期。寻找与病毒复制相关的宿主因子并揭示其作用机制,将有助于阐明病毒的感染机制,为疫病的防治提供新靶标。与RNA干扰技术相比,近年来兴起的CRISPR/Cas9技术能更特异、高效、准确地实现基因组编辑,因而在功能基因研究中得到更广泛应用。而基于CRISPR/Cas9系统的宿主全基因组sgRNA文库高通量筛选技术平台,可快速发现参与病毒侵入、复制等生物学过程的关键宿主因子,通过明确病毒-宿主分子相互作用进而揭示病毒的生命周期,为分子病毒学和免疫学提供了强大的研究工具。本文主要总结了基于CRISPR/Cas9技术的高通量筛选平台的具体筛选流程,归纳和讨论了该平台在筛选调控病毒复制相关宿主因子中的应用现状和发展前景。     

DNA2 and EXO1 in replication-coupled,homology-directed repair and in the interplay between HDR and the FA/BRCA network

During DNA replication, stalled replication forks and DSBs arise when the replication fork encounters ICLs (interstrand crosslinks), covalent protein/DNA intermediates or other discontinuities in the template. Recently, homologous recombination proteins have been shown to function in replication-coupled repair of ICLs in conjunction with the Fanconi anemia (FA) regulatory factors FANCD2-FANCI, and, conversely, the FA gene products have been shown to play roles in stalled replication fork rescue even in the absence of ICLs, suggesting a broader role for the FA network than previously appreciated. Here we show that DNA2 helicase/nuclease participates in resection during replication-coupled repair of ICLs and other replication fork stresses. DNA2 knockdowns are deficient in HDR (homology-directed repair) and the S phase checkpoint and exhibit genome instability and sensitivity to agents that cause replication stress. DNA2 is partially redundant with EXO1 in these roles. DNA2 interacts with FANCD2, and cisplatin induces FANCD2 ubiquitylation even in the absence of DNA2. DNA2 and EXO1 deficiency leads to ICL sensitivity but does not increase ICL sensitivity in the absence of FANCD2. This is the first demonstration of the redundancy of human resection nucleases in the HDR step in replication-coupled repair, and suggests that DNA2 may represent a new mediator of the interplay between HDR and the FA/BRCA pathway.     

DNA2 and EXO1 in replication-coupled,homology-directed repair and in the interplay between HDR and the FA/BRCA network

During DNA replication, stalled replication forks and DSBs arise when the replication fork encounters ICLs (interstrand crosslinks), covalent protein/DNA intermediates or other discontinuities in the template. Recently, homologous recombination proteins have been shown to function in replication-coupled repair of ICLs in conjunction with the Fanconi anemia (FA) regulatory factors FANCD2-FANCI, and, conversely, the FA gene products have been shown to play roles in stalled replication fork rescue even in the absence of ICLs, suggesting a broader role for the FA network than previously appreciated. Here we show that DNA2 helicase/nuclease participates in resection during replication-coupled repair of ICLs and other replication fork stresses. DNA2 knockdowns are deficient in HDR (homology-directed repair) and the S phase checkpoint and exhibit genome instability and sensitivity to agents that cause replication stress. DNA2 is partially redundant with EXO1 in these roles. DNA2 interacts with FANCD2, and cisplatin induces FANCD2 ubiquitylation even in the absence of DNA2. DNA2 and EXO1 deficiency leads to ICL sensitivity but does not increase ICL sensitivity in the absence of FANCD2. This is the first demonstration of the redundancy of human resection nucleases in the HDR step in replication-coupled repair, and suggests that DNA2 may represent a new mediator of the interplay between HDR and the FA/BRCA pathway.     

不同水平呼气末正压对老年腹腔镜下结直肠癌根治术患者脑氧供需平衡、炎症因子和脑损伤标志物的影响

摘要 目的：探讨不同水平呼气末正压（PEEP）对老年腹腔镜下结直肠癌根治术患者脑氧供需平衡、炎症因子和脑损伤标志物的影响。方法：选择我院2019年12月-2020年12月收治的90例行腹腔镜下结直肠癌根治术患者,根据随机数字表法分为A组（n=30）、B组（n=30）、C组（n=30）,每组均为压力控制容量保证（PCV-VG）模式联合小潮气量加滴定PEEP;其中C组的PEEP值为肺动态顺应性（Cdyn）滴定法下最适PEEP,B组的PEEP=5 cm H₂O,A组的PEEP=0 cm H₂O。对比三组脑氧供需平衡、炎症因子和脑损伤标志物,同时记录三组治疗期间不良反应发生率。结果：气腹后15 min（T1）、停气腹平卧位15 min（T2）时间点,B组、C组颈内静脉血氧饱和度（SjvO₂）、动脉-颈内静脉血氧含量差（AVDO₂）、局部脑组织氧饱和度（rScO₂）高于A组,且C组高于B组同时间点（P<0.05）。术后1 d,B组、C组血清白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）水平低于A组,且C组低于B组同时间点（P<0.05）。术后1 d,B组、C组血清神经元特异性烯醇化酶（NSE）、S100β低于A组,但C组低于B组同时间点,而脑源性神经营养因子（BDNF）水平高于A组,且C组高于B组同时间点（P<0.05）。三组不良反应发生率组间对比无统计学差异（P>0.05）。结论：Cdyn滴定法下最适PEEP可维持老年腹腔镜下结直肠癌根治术患者脑氧供需平衡,减轻炎症因子分泌,降低脑损伤标志物水平,安全性较好。     

The advancements,challenges, and future implications of the CRISPR/Cas9 system in swine research

Clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(CRISPR/Cas9) genome editing technology has dramatically influenced swine research by enabling the production of high-quality disease-resistant pig breeds, thus improving yields. In addition, CRISPR/Cas9 has been used extensively in pigs as one of the tools in biomedical research. In this review, we present the advancements of the CRISPR/Cas9 system in swine research, such as animal breeding, vaccine development, xenotransplantation, and disease modeling. We also highlight the current challenges and some potential applications of the CRISPR/Cas9 technologies.     

单孔与两孔胸腔镜下肺大疱切除手术治疗气胸的效果对比

目的:对比单孔与两孔胸腔镜下肺大疱切除手术治疗气胸的效果。方法:选取2015年9月～2018年10月我院收治的自发性气胸患者81例,采用随机数字表法将患者分为两组,观察组行单孔胸腔镜下肺大疱切除术,对照组行两孔胸腔镜下肺大疱切除术。比较两组患者的手术相关指标、术后疼痛评分、手术前后血清肿瘤坏死因子-α(Tumor necrosis factor-α, TNF-α)、白细胞介素1β(Interleukin-1β,IL-1β)和C反应蛋白(C-reactive protein,CRP)水平的变化及并发症的发生情况。结果:两组患者的手术时间比较无统计学差异(P0.05),观察组患者的术中出血量、术后引流量、引流管留置时间和切口长度均显著少于或短于对照组(P0.05);观察组患者术后3d和术后3个月的视觉模拟评分(Visual analogue scale,VAS)显著低于对照组(P0.05),两组术后1年VAS评分比较无统计学差异(P0.05)。术后7d,两组患者的血清TNF-α、IL-1β和CRP水平均较术前显著降低,且观察组显著低于对照组(P0.05)。两组患者并发症的发生率比较无统计学差异(P0.05)。结论:与两孔胸腔镜下肺大疱切除术相比,单孔胸腔镜下肺大疱切除术用于气胸患者的创伤更小,更有利于患者术后恢复,且安全性更高。     

妊娠期缺铁性贫血的影响因素及琥珀酸亚铁片的治疗效果研究

摘要 目的：研究妊娠期缺铁性贫血（IDA）的影响因素及琥珀酸亚铁片的治疗效果。方法：选取2017年5月~2019年6月期间我院收治的妊娠期IDA患者156例作为贫血组,选取同期于我院体检的健康妊娠期志愿者100例作为非贫血组。采用抽签法将贫血组患者分为对照组（常规治疗）和研究组（常规治疗基础上给予琥珀酸亚铁片治疗）,各78例,均治疗8周。对比贫血组各亚组患者的疗效、血象指标、铁代谢指标及不良反应发生情况。采用Logistic回归分析妊娠期IDA的影响因素。结果：治疗8周后,研究组的临床总有效率高于对照组（P<0.05）。治疗8周后,研究组的平均血红蛋白量（MCH）、血红蛋白（Hb）、平均红细胞体积（MCV）高于对照组,红细胞体积分布宽度（RDW）低于对照组（P<0.05）。治疗8周后,研究组的血清铁蛋白（SF）、血清铁（SI）高于对照组,血清转铁蛋白受体（sTFR）、总铁结合力（TIBC）低于对照组（P<0.05）。两组的不良反应发生率对比无统计学差异（P>0.05）。单因素分析发现,妊娠期IDA发病与年龄、文化程度、家庭月收入、是否存在不良饮食习惯、是否有慢性胃肠道疾病史、月经初潮年龄、初次性交年龄、初次妊娠年龄、人工流产次数、产次有关（P<0.05）,而与体质量指数无关（P>0.05）。Logistic 回归分析结果显示,年龄>30岁、文化程度为初中及以下、存在不良饮食习惯、伴有慢性胃肠道疾病史、月经初潮年龄<13岁、初次妊娠年龄<18岁、人工流产次数>3次是妊娠期 IDA发病的独立危险因素（P<0.05）。结论：引起妊娠期IDA发病的影响因素较多,应针对这些因素进行干预,以降低妊娠期 IDA 的发生率。琥珀酸亚铁片治疗妊娠期IDA,可有效调节铁代谢,改善红细胞形态,缓解贫血症状,且不增加不良反应发生率。     

药物干预和手术切除治疗儿童阻塞性睡眠呼吸暂停低通气综合征的疗效评估

目的:对比分析药物干预和手术切除治疗儿童阻塞性睡眠呼吸暂停低通气综合征(OSAHS)的临床疗效。方法:应用随机数字表法将2015年2月至2017年11月经本院确诊的100例OSAHS患儿分为药物组、手术组,每组50例。药物组采用孟鲁司特钠治疗6个月,手术组行腺样体和扁桃体切除术。6个月后比较两组患儿多导睡眠图监(PSG)的监测结果和生活质量情况,比较两组疗效评定情况,记录手术组无效及并发症的原因。结果:6个月后,药物组、手术组患儿呼吸暂停低通气指数(AHI)、阻塞性呼吸暂停指数(OAI)、微觉醒指数(MAI)和睡眠呼吸紊乱指数(RDI)较治疗前降低,且手术组患儿AHI低于药物(P0.05)。手术组患儿6个月后睡眠障碍、对监护人的影响、身体症状评分较治疗前降低,且低于药物组(P0.05),而药物组治疗前后OSA-18评分各指标比较差异无统计学意义(P0.05)。手术组患儿总有效率为90.00%(45/50),高于药物组的50.00%(25/50),差异有统计学意义(P0.05)。手术组患儿有出血现象的4例、伴舌后坠2例、上呼吸反复道感染6例和鼻炎5例,无效的5例患儿为伴有肥胖的重度OSAHS。结论:对于OSAHS患儿,药物干预和手术切除均可改善患儿PSG指标水平,但手术切除治疗可提高患儿生活质量和治疗有效率。     

PI3K/AKT/mTOR信号通路及其在卵巢癌治疗中的应用

卵巢癌是女性生殖系统常见的恶性肿瘤,发病率居于妇科恶性肿瘤第三位,死亡率居于妇科恶性肿瘤之首。目前对卵巢癌的标准治疗包括肿瘤细胞减灭术及卡铂和紫杉醇的联合化疗。PI3K/AKT/mTOR信号通路在卵巢癌的细胞增殖、侵袭、细胞周期进展、血管生成及耐药中发挥重要作用,是卵巢癌中最常发生改变的细胞内途径。本文对PI3K/AKT/mTOR信号通路及其在卵巢癌增殖和进展中的影响、PI3K/AKT/mTOR信号通路抑制剂在卵巢癌中的治疗应用做简要综述。     

宫腔镜子宫内膜电切术治疗功能失调性子宫出血的疗效及对患者性激素水平的影响

目的:探讨宫腔镜子宫内膜电切术治疗功能失调性子宫出血的疗效及对患者性激素水平的影响。方法:从本院2016年7月-2017年7月收治的围绝经期功能失调性子宫出血患者中选取94例,按随机数字表法分为对照组和观察组,各47例。对照组采用曼月乐进行治疗,观察组采用宫腔镜子宫内膜电切术治疗。比较两组治疗后3个月、6个月、12个月的治疗效果,检测两组治疗前、治疗后3个月、6个月、12个月血红蛋白(Hb)含量及血清垂体催乳素(PRL)、孕酮(P)、促卵泡生成素(FSH)、促黄体生成素(LH)、睾酮(T)、雌二醇(E2)水平。随访1年,观察两组患者的不良反应发生情况。结果:观察组治疗后3个月、6个月、12个月的总有效率分别为100.00%、95.74%、95.74%,均分别高于对照组的93.62%、89.36%、87.23%,但两组各时期比较差异无统计学意义(P0.05)。两组患者治疗后3个月、6个月、12个月的Hb含量均高于治疗前,且观察组治疗后3个月、6个月、12个月的Hb含量均明显高于对照组(P0.05)。治疗后6个月、12个月,对照组的PRL、P、FSH、LH、T水平均高于治疗前和观察组,而E2水平低于治疗前和观察组(P0.05)。观察组治疗后3个月、6个月、12个月的各项性激素指标水平与治疗前比较差异均无统计学意义(P0.05)。观察组不良反应发生率为4.26%,低于对照组的21.28%(P0.05)。结论:宫腔镜子宫内膜电切术治疗功能失调性子宫出血疗效确切,能明显改善患者贫血状况,且对性激素水平无明显影响,具有较好的安全性。     

右美托咪定对老年胸腔镜肺癌根治术患者拔管时血流动力学及术后疼痛的影响

目的:探讨右美托咪定对老年胸腔镜肺癌根治术患者拔管时血流动力学以及术后疼痛的影响。方法:选取67例择期行胸腔镜肺癌根治术的老年患者,根据随机数字表法分为对照组(n=33例)和研究组(n=34例),均予咪达唑仑、顺苯磺酸阿曲库铵、舒芬太尼、丙泊酚麻醉诱导,对照组同时予15 mL生理盐水静脉注射,研究组同时予0.5μg/kg右美托咪定静脉注射(15 min),术毕后均开启自控静脉镇痛(PCIA)泵。监测两组诱导前(T_0)、诱导后5 min(T_1)、入PACU时(T_2)、拔管即刻(T_3)、拔管后5 min(T_4)血流动力学指标,评估出PACU时(T_5)、术后2 h(T_6)、术后4 h(T_7)、术后6 h(T_8)、术后12 h(T_9)、术后24 h(T_10)疼痛视觉模拟量表(VAS)评分,检测T_0、T_8、T_9、T_10动脉血气评价肺功能,同时比较拔管时间、拔管质量评分、镇痛泵按压次数、24 h舒芬太尼用量及围术期不良反应。结果:与T0相比,对照组T_3、T_4时平均动脉压(MAP)、心率(HR)、中心静脉压(CVP)升高(P0.05),研究组T_3时MAP、HR、CVP升高(P0.05),与对照组相比,研究组T_3、T_4时MAP、HR、CVP较低(P0.05);与对照组相比,研究组T_6、T_7、T_8、T_9、T_10时VAS评分较低(P0.01);两组T_8、T_9、T_10时Qs/Qt升高(P0.05),OI、PaO_2/PAO_2降低(P0.05),与对照组相比,研究组T8、T9、T10时Qs/Qt较低(P0.05),OI、PaO_2/PAO_2较高(P0.05);与对照组相比,研究组拔管质量评分未见差异(P0.05),镇痛泵按压次数较少(P0.05),24 h舒芬太尼用量较少(P0.01)。结论:右美托咪定可明显稳定老年胸腔镜肺癌根治术拔管期血流动力学,并有较好的术后镇痛效果,一定程度上改善患者术后肺功能。     

Activities of multiple cancer-related pathways are associated with BRAF mutation and predict the resistance to BRAF/MEK inhibitors in melanoma cells

Drug resistance is a major obstacle in the targeted therapy of melanoma using BRAF/MEK inhibitors. This study was to identify BRAF V600E-associated oncogenic pathways that predict resistance of BRAF-mutated melanoma to BRAF/MEK inhibitors. We took in silico approaches to analyze the activities of 24 cancer-related pathways in melanoma cells and identify those whose activation was associated with BRAF V600E and used the support vector machine (SVM) algorithm to predict the resistance of BRAF-mutated melanoma cells to BRAF/MEK inhibitors. We then experimentally confirmed the in silico findings. In a microarray gene expression dataset of 63 melanoma cell lines, we found that activation of multiple oncogenic pathways preferentially occurred in BRAF-mutated melanoma cells. This finding was reproduced in 5 additional independent melanoma datasets. Further analysis of 46 melanoma cell lines that harbored BRAF mutation showed that 7 pathways, including TNFα, EGFR, IFNα, hypoxia, IFNγ, STAT3, and MYC, were significantly differently expressed in AZD6244-resistant compared with responsive melanoma cells. A SVM classifier built on this 7-pathway activation pattern correctly predicted the response of 10 BRAF-mutated melanoma cell lines to the MEK inhibitor AZD6244 in our experiments. We experimentally showed that TNFα, EGFR, IFNα, and IFNγ pathway activities were also upregulated in melanoma cell A375 compared with its sub-line DRO, while DRO was much more sensitive to AZD6244 than A375. In conclusion, we have identified specific oncogenic pathways preferentially activated in BRAF-mutated melanoma cells and a pathway pattern that predicts resistance of BRAF-mutated melanoma to BRAF/MEK inhibitors, providing novel clinical implications for melanoma therapy.