Luciferase expression and bioluminescence does not affect tumor cell growth in vitro or in vivo

Live animal imaging is becoming an increasingly common technique for accurate and quantitative assessment of tumor burden over time. Bioluminescence imaging systems rely on a bioluminescent signal from tumor cells, typically generated from expression of the firefly luciferase gene. However, previous reports have suggested that either a high level of luciferase or the resultant light reaction produced upon addition of D-luciferin substrate can have a negative influence on tumor cell growth. To address this issue, we designed an expression vector that allows simultaneous fluorescence and luminescence imaging. Using fluorescence activated cell sorting (FACS), we generated clonal cell populations from a human breast cancer (MCF-7) and a mouse melanoma (B16-F10) cell line that stably expressed different levels of luciferase. We then compared the growth capabilities of these clones in vitro by MTT proliferation assay and in vivo by bioluminescence imaging of tumor growth in live mice. Surprisingly, we found that neither the amount of luciferase nor biophotonic activity was sufficient to inhibit tumor cell growth, in vitro or in vivo. These results suggest that luciferase toxicity is not a necessary consideration when designing bioluminescence experiments, and therefore our approach can be used to rapidly generate high levels of luciferase expression for sensitive imaging experiments.     

组蛋白去乙酰化酶抑制剂SAHA体外抑制人卵巢癌SKOV3细胞的实验研究

  目的   目的: 观察组蛋白去乙酰化酶抑制剂辛二酰苯胺异羟肟酸(suberoylanilide hydroxamic acid, SAHA) 体外对人卵巢癌SKOV3细胞增殖和凋亡的作用, 并探讨其可能机制。   方法  体外应用SAHA作用于人卵巢癌SKOV3细胞, MTT法检测细胞增殖, 流式细胞术检测细胞凋亡率。Western blot法检测细胞内组蛋白H4乙酰化水平, 实时定量PCR方法检测p21、Bcl-2和Bax基因mRNA表达。   结果  经SAHA作用后的人卵巢癌SKOV3细胞生长受到抑制, 细胞凋亡增加(各实验组与对照组比较, 均P < 0.05), 呈剂量依赖性; 同时细胞内组蛋白H4乙酰化水平增加, p21基因和Bax基因mRNA表达增加(各实验组与对照组比较, 均P < 0.05), 呈剂量依赖性, Bcl-2基因表达无明显变化(各实验组与对照组比较, 均P > 0.05)。   结论  SAHA体外可抑制人卵巢癌SKOV3细胞增殖和诱导SKOV3细胞凋亡, 提高组蛋白乙酰化水平, 增加p21和Bax基因表达可能是其作用机制之一。      

Gonadotropin-releasing hormone type II antagonist induces apoptosis in MCF-7 and triple-negative MDA-MB-231 human breast cancer cells in vitro and in vivo

Introduction  

Triple-negative breast cancer does not express estrogen and progesterone receptors, and no overexpression/amplification of the HER2-neu gene occurs. Therefore, this subtype of breast cancer lacks the benefits of specific therapies that target these receptors. Today chemotherapy is the only systematic therapy for patients with triple-negative breast cancer. About 50% to 64% of human breast cancers express receptors for gonadotropin-releasing hormone (GnRH), which might be used as a target. New targeted therapies are warranted. Recently, we showed that antagonists of gonadotropin-releasing hormone type II (GnRH-II) induce apoptosis in human endometrial and ovarian cancer cells in vitro and in vivo. This was mediated through activation of stress-induced mitogen-activated protein kinases (MAPKs) p38 and c-Jun N-terminal kinase (JNK), followed by activation of proapoptotic protein Bax, loss of mitochondrial membrane potential, and activation of caspase-3. In the present study, we analyzed whether GnRH-II antagonists induce apoptosis in MCF-7 and triple-negative MDA-MB-231 human breast cancer cells that express GnRH receptors. In addition, we ascertained whether knockdown of GnRH-I receptor expression affects GnRH-II antagonist-induced apoptosis and apoptotic signaling.     

miRNA海绵在胃癌细胞EMT过程中调控作用的体外研究

  目的   探讨“miRNA海绵”在胃癌细胞系SGC7901上皮-间质转化（EMT）过程中的作用及机制。   方法   将人工合成的ZEB2 3'UTR质粒及siZEB2采用脂质体Lipofectamine 2000转染SGC7901细胞。qRT-PCR检测转染后miR-200a/b/c的表达;Transwell侵袭实验、划痕实验和克隆形成实验检测细胞侵袭迁移增殖能力;Western Blot检测目的蛋白的表达。   结果   与对照组相比,ZEB2 3'UTR转染组miR-200a/b/c的表达均下调,迁移、侵袭、增殖活性均增强;而转染siZEB2后miR-200a/b/c表达均升高,迁移、侵袭、增殖能力则下降。Western Blot显示ZEB2 3'UTR转染导致ZEB2表达升高,E-cadherin表达下降,而Vimentin表达上调;而转染siZEB2后,各项指标则表现出相反的表达趋势。   结论   ZEB2 3'UTR可以通过调控miR-200a/b/c的表达调控胃癌细胞EMT过程,调节肿瘤的侵袭与转移。      

Gain in cellular organization of inflammatory breast cancer: A 3D in vitro model that mimics the in vivo metastasis

Background  

The initial step of metastasis in carcinomas, often referred to as the epithelial-mesenchymal transition (EMT), occurs via the loss of adherens junctions (e.g. cadherins) by the tumor embolus. This leads to a subsequent loss of cell polarity and cellular differentiation and organization, enabling cells of the embolus to become motile and invasive. However highly malignant inflammatory breast cancer (IBC) over-expresses E-cadherin. The human xenograft model of IBC (MARY-X), like IBC, displays the signature phenotype of an exaggerated degree of lymphovascular invasion (LVI) in situ by tumor emboli. An intact E-cadherin/α, β-catenin axis mediates the tight, compact clump of cells found both in vitro and in vivo as spheroids and tumor emboli, respectively.     

In vivo stimulation by tamoxifen of cathepsin D RNA level in breast cancer

We have previously shown that 3 weeks of treatment with tamoxifen, of patients with primary breast carcinomas, increased cytosolic cathepsin D protein in oestrogen receptor (ER) positive tumours [Maudelonde et al., Cancer 1989, 63, 1265–1270]. In order to investigate the mechanism of this increase and to eliminate a transient flare-up effect, we semi-quantified cathepsin D RNA levels by in situ hybridisation in 32 breast carcinomas from patients treated with tamoxifen for 3 weeks prior to surgery and in 35 breast cancer patients receiving no tamoxifen. We found that tamoxifen increased cathepsin D RNA level regardless of the ER status of the tumours. In ER positive tumours, tamoxifen increased the cathepsin D RNA level to the same extent as cytosolic cathepsin D protein but not in ER negative tumours. The induction of cathepsin D RNA by tamoxifen in ER positive tumours was probably due to its agonist activity, also observed in vitro in breast cancer cell lines. These results suggest that the cathepsin D gene is inducible by oestrogens in ER positive breast cancer as it is in breast cancer cell lines.     

Vasohibin inhibits angiogenic sprouting in vitro and supports vascular maturation processes in vivo

Background  

The murine homologue of human vasohibin (mVASH1), a putative antiangiogenic protein, was investigated for its effects on in vitro and in vivo angiogenesis.     

Effect of radiation on the expression of E-cadherin and α-catenin and invasive capacity in human lung cancer cell line in vitro

Purpose: To investigate the effect of radiation on E-cadherin and α-catenin expression in a human lung cancer cell line, and also evaluate invasive capacity in the membrane invasion culture system using the Boyden Chamber.Materials and Methods: The immunoblot and immunofluorescence analyses were performed using the human lung cancer cell line A549 to examine altered expression of E-cadherin and α-catenin after irradiation. We also compared invasive capacity of untreated cells with that of irradiated cells.Results: Immunoblot analysis revealed that the expression of E-cadherin increased after irradiation. In a time-course analysis, the expression was increased 6 h after irradiation with 10 Gy and reached its peak level at 24 h, being 2.3 times the control value, whereas expression at 1 and 3 h after irradiation was almost equivalent to that of the control. A slight increase in expression was observed after irradiation of 2 Gy and the expression reached peak levels after 5 Gy. After fractionated irradiation, the increase in expression of both E-cadherin and α-catenin was observed, and the alteration of α-catenin was more prominent than that after a single irradiation of the same total dose. In the immunofluorescence study for E-cadherin antibody analyzed by confocal laser scanning microscopy, increased intensity in irradiated cells produced as a nondisrupted and continuous line at cell–cell contact sites. In an invasive assay, the number of migrated cells in irradiated cells after a dose of 5 and 10 Gy was reduced significantly compared to untreated cells.Conclusion: The results indicate that irradiation of A549 increased the expression of E-cadherin, possibly preserving their functional property.     

Schedule-dependent interaction between paclitaxel and doxorubicin in human cancer cell lines in vitro

The schedule-dependent interaction of paclitaxel and doxorubicin was evaluated in four human cancer cell lines. The cells were exposed simultaneously or sequentially to the two agents for 24 h, and were then incubated in drug-free medium for 4 and 3 days, respectively. The cell growth inhibitions were determined by the MTT assay. The cytotoxic interactions at the ₈₀ level were evaluated by the isobologram method of Steel and Peckham. In non-small cell lung cancer A549, breast cancer MCF7 and colon cancer WiDr cells, antagonistic effects were observed for the paclitaxel and doxorubicin combination on simultaneous exposure to the two agents and on sequential exposure to doxorubicin followed by paclitaxel, while additive effects were observed for the combination on sequential exposure to paclitaxel followed by doxorubicin. In ovarian cancer PA1 cells, additive effects were observed for all schedules. These findings suggest that sequential administration of paclitaxel followed by doxorubicin may be the most suitable sequence, while the simultaneous administration of the two agents and the sequential administration of doxorubicin followed by paclitaxel may result in less tumour cell kill than anticipated. Further preclinical and clinical studies are required to elucidate the relationship between paclitaxel and doxorubicin with regard to both antitumour activity and toxicity.     

Dynamic distribution and expression in vivo of the human interferon gamma gene delivered by adenoviral vector

Background  

We previously found that r-hu-IFNγ exerts a potent anti-tumor effect on human nasopharyngeal carcinoma xenografts in vivo. Considering the fact that the clinical use of recombinant IFNγ is limited by its short half-life and systemic side effects, we developed a recombinant adenovirus, Ad-IFNγ.     

In vitro and in vivo efficacy of 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) on human melanoma

6-(7-Nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) is a powerful inhibitor of the glutathione transferase P1-1 (GSTP1-1) and causes the disruption of the complex between GSTP1-1 and c-Jun N-terminal Kinase (JNK). This induces JNK activation and apoptosis in tumour cells. In the present work we assess the in vitro and in vivo effectiveness of NBDHEX on two human melanoma cell lines, Me501 and A375. NBDHEX shows IC₅₀ values in the low micromolar range (IC₅₀ of 1.2 ± 0.1 μM and 2.0 ± 0.2 μM for Me501 and A375, respectively) and is over 100 times more cytotoxic to these cell lines than temozolomide. Apoptosis is observed in Me501 cells within 3 h of the addition of NBDHEX, while in A375 cells the apoptotic event is rather late, and is preceded by a G2/M phase arrest. In both melanoma cell lines, JNK activity is required for the ability of NBDHEX to trigger apoptosis, confirming that the JNK pathway is an important therapeutic target for this tumour. NBDHEX is also both effective and well tolerated in in vivo tumour models. A tumour inhibition of 70% is observed in vivo against Me501 human melanoma and a similar result is obtained on A375 model, with 63% of tumour inhibition. These findings indicate that the activation of the JNK pathway, through a selective GSTP1-1 targeting, could prove to be a promising new strategy for treating melanoma, which responds poorly to conventional therapies.     

YAP调控人胶质瘤细胞生长的体外研究

  目的   研究YAP（Yes-associated protein）调控人脑胶质瘤细胞系LN229细胞生长的作用。   方法   采用YAP干扰RNA（siRNA）敲低LN229细胞中YAP的表达,Western Blot法鉴定肿瘤细胞中YAP是否已被敲低;MTT比色法测定YAP敲低后对肿瘤细胞增殖的影响;Transwell实验检测胶质瘤细胞侵袭能力的变化;流式细胞术和Annexin Ⅴ标记法分别检测胶质瘤细胞周期及凋亡的变化。Western Blot法检测相关蛋白。   结果   经Western Blot法检测证实转染YAP siRNA后LN229细胞中YAP被有效敲低;敲低LN229细胞中YAP表达,可以抑制胶质瘤细胞增殖,阻滞细胞周期于G₀/G₁期,并可抑制细胞侵袭能力,促使细胞凋亡数显著增加。促增殖蛋白Ki-67、促侵袭蛋白MMP-9、促周期进展蛋白Cyclin D1以及凋亡相关蛋白Bcl-2表达明显下调。   结论   敲低人胶质瘤细胞中YAP活性可以抑制肿瘤细胞增殖和侵袭,促进凋亡,为进一步探究Hippo-YAP信号通路在胶质瘤中的分子病理机制中的作用提供依据。      

In vitro toxicity of Pt-labeled cisplatin to a human cervical carcinoma cell line (ME-180)

Purpose: The aim of the present work was to examine the effect of ¹⁹¹Pt-cisplatin, and to study the manner in which radiation and cisplatin interact, in a human cervical carcinoma cell line (ME-180).

Methods and Materials: The cells were incubated for 1 hour with nonradioactive cisplatin or ¹⁹¹Pt-cisplatin with specific activities in the range 48–167 MBq/mg. The surviving fraction of the cells after 7 days’ growth was determined with a nonclonogenic tetrazolium-based (MTT) assay. The uptake of platinum into the cell and the amount of platinum bound to DNA was measured.

Results: The 50% inhibition concentration (IC₅₀) decreased with increasing specific activity of the ¹⁹¹Pt-cisplatin. For the specific activities 0 (nonradioactive), 48, 89, 143, 157, and 167 MBq/mg, IC₅₀ was found to be 3.24 ± 0.08, 2.77 ± 0.55, 2.17 ± 0.34, 1.15 ± 0.04, 1.02 ± 0.03, and 0.76 ± 0.13 respectively. Isobologram analysis showed a supra-additive (synergistic) interaction between the radiotoxicity and chemotoxicity for specific activities over 100 MBq/mg.

Conclusion: The cytotoxic effect of cisplatin may be enhanced by labeling the drug with the radionuclide ¹⁹¹Pt.     

Benzyl isothiocyanate inhibits murine WEHI-3 leukemia cells in vitro and promotes phagocytosis in BALB/c mice in vivo

Many evidences have shown that dietary intake of cruciferous vegetables could protect against the risk of various types of malignancies. Benzyl isothiocyanate (BITC), one of the compounds from cruciferous vegetables, had shown induced cell cycle arrest and apoptosis in cancer cells. However, there is no available information to address that BITC affects murine leukemia cells in vitro and in vivo. Here, we investigated in vitro effects of BITC on murine leukemia WEHI-3 cells. BITC decreased the percentage of viable cells via G0/G1 arrest and apoptosis in WEHI-3 cells. BITC induced apoptosis through the dysfunction of mitochondria (decreased the levels of mitochondria membrane potential) and activation of caspase-3. Then we investigated in vivo effects of BITC on murine leukemia WEHI-3 cells and the results indicated that BITC decreased the weights of liver and spleen and it also decreased the percentage of CD11b and Mac-3 markers, indicating that the differentiation of the precursor of macrophage and B cells was inhibited. BITC promoted the activity of macrophage phagocytosis in cells which are isolated from PBMC and peritoneal (i.p.). Taken together, BITC can affect WEHI-3 cells in vitro and in vivo.     

Myosin X对肺癌H1975细胞系放射敏感性调节及机制探讨

目的:探讨Myosin X对肺癌H1975细胞系放射敏感性调节及相关机制。方法:蛋白免疫印迹法检测肺癌细胞系中Myosin X表达量以获取实验对象。运用CRISPR/Cas9技术建立敲除Myosin X的H1975细胞系(KO组)和感染对照病毒的H1975细胞系(NC组),并进行敲除效率验证。克隆形成实验及多靶单击模型...     

Amiloride inhibits the growth of human colon cancer cells in vitro

Cytoplasmic alkalinization induced by activation of the antiport plays an essential role in the initiation of cell proliferation. In the present study we examined the effects of amiloride, a specific and reversible inhibitor of antiporter, on the growth of human colon cancer cells (HT-29). Amiloride (50–800 μm) inhibited the growth of HT-29 cells in a dose-dependent fashion. Forty-three percent inhibition of growth was found at an amiloride concentration of 400 μm after 4 days of treatment. The inhibitory effect of amiloride on growth of HT-29 cells was reversible since removal of amiloride by a media change after 48 h treatment lead to rapid regrowth to control levels. The reversibility of growth inhibition suggests that amiloride is not a non-specific cytotoxin for HT-29 cells. We examined the possible mechanisms for the inhibitory effects of amiloride. Amiloride (400 μM) completely abolished serum-stimulated ODC activity and inhibited difluoromethylornithine (DMFO)-stimulated putrescine uptake by 56%. We conclude that amiloride inhibits the in vitro growth of human colon cancer cells; since ODC-activity and polyamine transport were both inhibited, the inhibitory effects may be mediated in part by polyamine-dependent processes. Amiloride may be a useful agent in the treatment of colon cancer.     

The effect of low-level laser irradiation (In-Ga-Al-AsP - 660 nm) on melanoma in vitro and in vivo

Background  

It has been speculated that the biostimulatory effect of Low Level Laser Therapy could cause undesirable enhancement of tumor growth in neoplastic diseases. The aim of the present study is to analyze the behavior of melanoma cells (B16F10) in vitro and the in vivo development of melanoma in mice after laser irradiation.     

Adenovirus vector-mediated expression of TMEM166 inhibits human cancer cell growth by autophagy and apoptosis in vitro and in vivo

TMEM166 is a novel programmed cell death-related molecule. In this report, we constructed a recombinant adenovirus 5-TMEM166 vector (Ad5-TMEM166) and evaluated its expression and anti-tumor activities in vitro and in vivo. Cell viability analysis revealed that the adenovirus-mediated increase of TMEM166 inhibited tumor cell growth in a dose- and time-dependent manner. This inhibitory effect was mediated by both autophagy (via inhibition of mTOR and activation of p70S6K) and apoptosis (via caspase-3 activation), both of which contributed to cell death and suppression of tumorigenicity. Our data indicated that Ad5-TMEM166 may be a novel gene therapy candidate for cancer.