Cancer stem cells in lung cancer: Evidence and controversies

The cancer stem cell (CSC) model is based on a myriad of experimental and clinical observations suggesting that the malignant phenotype is sustained by a subset of cells characterized by the capacity for self‐renewal, differentiation and innate resistance to chemotherapy and radiation. CSC may be responsible for disease recurrence after definitive therapy and may therefore be functionally synonymous with minimal residual disease. Similar to other solid tumours, several putative surface markers for lung CSC have been identified, including CD133 and CD44. In addition, expression and/or activity of the cytoplasmic enzyme aldehyde dehydrogenase ALDH and capacity of cells to exclude membrane permeable dyes (known as the ‘side population’) correlate with stem‐like function in vitro and in vivo. Embryonic stem cell pathways such as Hedgehog, Notch and WNT may also be active in lung cancers stem cells and therefore may be therapeutically targetable for maintenance therapy in patients achieving a complete response to surgery, radiotherapy or chemotherapy. This paper will review the evidence regarding the existence and function of lung CSC in the context of the experimental and clinical evidence and discuss some ongoing controversies regarding this model.     

急性心肌缺血对原儿茶醛在大鼠体内药动学的影响

结扎大鼠冠状动脉左前降支造成急性心肌缺血模型。4 h后,模型组大鼠和正常组大鼠分别腹腔注射原儿茶醛（20 mg/kg）,在不同时间点眼眶采血。用HPLC方法测定血浆中原儿茶醛及其代谢物原儿茶酸和香草酸的浓度,并对实验数据进行分析,从代谢角度考察急性心肌缺血对原儿茶醛在大鼠体内药动学的影响。结果表明,原儿茶醛在大鼠体内迅速代谢为原儿茶酸,后者甲基化代谢生成香草酸。与正常状态相比,急性缺血状态下原儿茶酸的AUC_0-∞显著增大(22.31±4.96 μg·h/mL vs 14.01±3.11 μg·h/mL,P<0.01);香草酸的AUCAUC_0-∞也显著增大（38.76±5.75 μg·h/mL vs 19.64±4.36 μg·h/mL,P<0.01);两者的MRT均显著增加,分别为：0.43±0.08 h vs 0.27±0.04 h (P<0.01);0.61±0.11 h vs 0.38±0.05 h (P<0.01)。原儿茶酸甲基化代谢比率M/P明显提高(1.77±0.22 vs 1.43±0.31,P<0.05)。提示急性心肌缺血状态下,原儿茶醛的主要代谢物原儿茶酸和香草酸在血浆中的暴露显著增强,原儿茶酸甲基化生成香草酸的水平明显提高。     

双硫仑对人脂肪肉瘤细胞系SW872细胞的抑制作用及其机制

目的观察双硫仑(DSF)对人脂肪肉瘤细胞SW872的抑制作用,并探讨其相关分子机制。方法体外培养SW872细胞,设立正常细胞对照组及DSF 1,2.5,5和10μmol·L^-1组,采用CCK-8法检测药物处理24 h后对细胞增殖的抑制作用;光镜下观察DSF处理后SW872细胞形态变化;流式细胞术检测细胞凋亡;克隆形成实验检测DSF对SW872细胞克隆形成能力的影响;Western印迹法检测A20的表达;CCK-8法检测铁离子螯合剂Fer-1及炎症小体NLRP3抑制剂MCC950能否逆转DSF对SW872细胞的抑制作用;RT-PCR法检测DSF对SW872细胞中A20和醛脱氢酶(ALDH1)的mRNA水平。结果 DSF对SW872细胞增殖有显著抑制作用(P<0.01);DSF处理后使SW872细胞发生皱缩变圆且细胞间隙增大;DSF作用于SW872细胞24 h后,与正常细胞对照组相比,DSF 1μmol·L^-1组细胞早期凋亡率明显增加〔(32.6±1.82)%vs(3.50±0.64)%,P<0.05〕;DSF 0.1μmol·L     

HPLC法测定血浆中丹参脂质体的原儿茶醛浓度

丹参(Salvia miltiorrhiza)具有活血化瘀、理气开窍,扩张血管与增加冠动脉血流量的作用。其水溶性成分为丹参素,原儿茶醛等。丹参脂质体,临床上用于预防手术病人的肠粘连。为了解该制剂体内吸收、消除情况,我们用反相高效液相色谱法(RP-HPLC),采用离子抑制技术分离     

中药丹参类的质量研究

分别测定了17种鼠尾草属植物(包括变种、变型)根中脂溶性成分总丹参酮和丹参酮Ⅱ_A、次甲丹参醌,丹参酮Ⅰ、丹参酸甲酯、隐丹参酮、二氢丹参酮Ⅰ、紫丹参甲素、丹参酮Ⅱ_B等8种丹参酮的含量,以及水溶性总酚和原儿茶醛、原儿茶酸的含量,对各种丹参进行质量比较和评价。     

反相高效液相色谱法同时测定通脉口服液中丹参素和原儿茶醛的含量

目的建立同时测定通脉口服液中丹参素和原儿茶醛含量的方法。方法采用RP-HPLC对制剂中主要成分丹参素和原儿茶醛进行定量分析,色谱柱Suntek Krom asil C18(250 mm×4.6 mm,5μm),甲醇-0.5%冰醋酸溶液(16∶84)为流动相,检测波长281 nm。结果RP-HPLC结果稳定,精密度、重现性良好,丹参素和原儿茶醛分别在0.315 2~1.260 8μg和0.043 0~0.172 2μg范围内有较好的线性关系,加样回收率分别为101.81%和100.47%,RSD为2.13%和2.79%。结论可有效控制制剂质量。     

Aldehyde dehydrogenase 1 is associated with recurrence‐free survival but not stem cell‐like properties in hepatocellular carcinoma

Aim: It has been reported that aldehyde dehydrogenase 1 A1 (ALDH1) could be not only a normal stem cell marker but also a cancer stem cell marker. ALDH1 expression could be a predictor of poor prognosis in a wide range of cancers. However, the role of ALDH1 in hepatocellular carcinoma (HCC) remains unclear. Method: We conducted loss‐of‐function assays for ALDH1 by using short‐hairpin RNA in HCC cells and evaluated the correlation between ALDH1 expression and clinicopathological features based on immunohistochemical assessment of 49 primary HCC tissues. Results: Neither cell proliferation nor the anchorage‐independent sphere formation ability of HCC cells were altered after ALDH1 knockdown. Flow cytometric analyses revealed that ALDH1 knockdown showed no remarkable change in the proportion of epithelial cell adhesion molecule (EpCAM)⁺ tumor‐initiating cells. Although non‐tumor tissues in primary HCC samples diffusely and homogenously expressed ALDH1 at low levels, tumor tissues contained cells with high levels of ALDH1 expression at varying frequencies. Primary HCC samples were categorized as ALDH1‐high or ALDH1‐low based on the percentage of ALDH1‐overexpressing cells. ALDH1‐high HCC was characterized by low serum levels of α‐fetoprotein (P < 0.01) and well‐differentiated pathology (P = 0.03). Multivariate analysis showed that high ALDH1 expression was a favorable prognostic factor in recurrence‐free survival of HCC (P = 0.02). Conclusion: Our findings show that ALDH1 expression has little association with stem cell‐like features in HCC cells. ALDH1 might function as a differentiation marker rather than a stem cell marker in HCC.     

ALDH1A1增强乳腺癌细胞血管生成因子表达并促进共培养HUVEC细胞小管形成和侵袭能力

目的:探讨干细胞标志物醛脱氢酶1A1（ALDH1A1）对乳腺癌细胞血管生成因子表达的影响,以及对与乳腺癌细胞共培养的HUVEC细胞小管形成和侵袭能力的影响。方法:采用免疫组化检测了乳腺癌组织和乳腺增生组织中ALDH1A1的表达。使用ALDH1A1 shRNA或过表达ALDH1A1的pcDNA3.1质粒转染乳腺癌细胞（MCF-7和MDA-MB-231）,通过qRT-PCR和Western blot检测敲低或过表达ALDH1A1对乳腺癌细胞中血管内皮生长因子（VEGF）、缺氧诱导因子-1α（HIF-1α）和白细胞介素-12（IL-12）表达的影响。通过用1 μmol/L 的外源性RA和RAR阻断剂（AGN 193109）处理乳腺癌细胞48 h来考察视黄酸信号通路是否参与ALDH1A1对VEGF和HIF-1α的调控过程。将乳腺癌细胞（MCF-7和MDA-MB-231）和HUVEC细胞共培养来模拟肿瘤形成的微环境,并检测HUVEC的小管形成能力和细胞侵袭能力。结果:乳腺癌组织的ALDH1A1染色平均光密度显著高于乳腺增生组织,并且淋巴结转移的乳腺癌组织显著高于未淋巴结转移的乳腺癌组织（P＜0.05）。敲低ALDH1A1可显著降低MCF-7和MDA-MB-231细胞中VEGF和HIF-1α蛋白表达,并上调IL-12蛋白表达。然而,上调ALDH1A1表达则可逆转上述变化。外源性RA处理可显著上调MCF-7和MDA-MB-231细胞中VEGF和HIF-1α的表达,然而,RAR阻断剂处理可抑制MCF-7和MDA-MB-231细胞中VEGF和HIF-1α的上调。敲低乳腺癌细胞中ALDH1A1的表达可导致共培养的HUVEC细胞的小管形成能力和侵袭能力显著降低。而上调乳腺癌细胞中ALDH1A1的表达则可显著促进共培养的HUVEC细胞的小管形成能力和侵袭能力。结论:在乳腺癌细胞中,ALDH1A1通过激活HIF-1α和视黄酸信号通路来上调血管生成因子的表达并提高共培养的内皮细胞的血管生成能力,从而增加肿瘤的侵袭性。     

薄层层析-紫外分光光度法测定丹参注射液中原儿茶醛的含量

目的：建立薄层层析-紫外分光光度法测定丹参注射液中原儿茶醛的含量。方法：以原儿茶醛为对照品，二氯甲烷-乙酸乙酯-甲酸（8：5：0.8）为展开剂，分离得到原儿茶醛，采用紫外分光光度法，检测波长281nm，测定原儿茶醛的含量。结果：原儿茶醛在0.50-4.50μg／ml范围内线性关系良好，r=0.9997。平均含量为0.202mg／ml，加样回收率为98.0％～103.0％。结论：实验结果表明，薄层层析-紫外分光光度法测定丹参注射液中原儿茶醛的含量，方法操作简便、准确度高、精密度好，可用于丹参注射液的质量控制。     

基于传质数学模型研究丹参-枳实复方中成分存在状态与纳滤分离机制

目的基于传质数学模型,探索丹参-枳实复方中成分存在状态与纳滤分离机制。方法以原儿茶醛、迷迭香酸、丹酚酸B、辛弗林为指标,进行单体成分溶液及丹参-枳实复方溶液纳滤分离,收集膜通量与指标成分截留率,基于传质模型中传质系数与溶质浓度的幂值相关性,以单一成分为参照,拟合复方溶液中成分存在状态,探讨纳滤分离机制。结果分离压力与膜通量呈正性相关,指标成分在单体溶液和复方溶液中传质系数与浓度幂值相关性高,回归系数均大于0.98,纳滤传质模型成立。通过单一成分传质特征构建复方溶液中成分状态解析模式,丹参-枳实复方溶液中指标成分以复合态存在的比例为原儿茶醛26.17%、迷迭香酸79.87%、丹酚酸B89.15%,辛弗林96.92%。结论构建了复方溶液的成分存在状态解析模式,阐明了丹参-枳实复方提取液纳滤分离机制,为中药成分分离精制提供技术支撑。