Induction of Anoikis in Human Colorectal Cancer Cells by Fucoxanthinol

Fucoxanthin (Fx), one of the major xanthophylls in brown algae, is known to be effective for colorectal cancer (CRC) chemoprevention through inhibiting cell growth, cell cycle and caspase activation. Recently, we observed fucoxanthinol (FuOH), an anti-cancer active metabolite of Fx, treatment of human CRC cells resulted in plenty of living floating cells several hours after exposure, and induced apoptosis. In the present study, we investigated whether FuOH induced anchorage-dependent apoptosis, that is “anoikis”, along with integrin signal suppression in human CRC cells. We found that cells exposed to 2.5 μM FuOH clearly showed anti-proliferative and apoptotic effects to DLD-1 cells, human CRC cells. FuOH treatment of DLD-1 cells led to an increase in anoikis-like changes represented by Calcein AM negative/ethidium homodimer-1 positive cell and living floating cells. Moreover, FuOH decreased FAK activation, and altered integrin β1 expression and distribution after 6 h treatment. After 24 h, the cells decreased PPARγ expression and Akt activation and increased integrin β1 expression. Our findings suggested that FuOH can induce anoikis in CRC cells through suppression of integrin signals in human CRC cells.     

镉诱导PC-3细胞金属硫蛋白和锌转运体的基因表达

[目的]研究镉对前列腺癌PC-3细胞中金属硫蛋白(Metalllothionein,MT)和锌转运体(Zinctransporter,ZnT)基因表达的影响。[方法]0、10、20、40、80和100μmol/L氯化镉处理PC-3细胞,细胞存活率用噻唑蓝(MTT)方法检测;MT-1F、MT-1X、MT-2A和ZnT-1基因的mRNA表达用RT-PCR进行检测。[结果]氯化镉(≥40μmol/L)对PC-3细胞具有明显的抑制生长作用(P<0.05)。MT-1F和MT-2A的mRNA水平在5μmol/L氯化镉诱导时表达水平达最高,随着氯化镉浓度的增高mRNA的表达呈下降趋势。MT-1X的mRNA表达水平随氯化镉浓度增加呈不断上升趋势,在40μmol/L表达水平为最高。ZnT-1的mRNA在10μmol/L氯化镉诱导表达水平为最高,随着氯化镉浓度的增高mRNA表达呈下降趋势。[结论]镉可诱导PC-3细胞MT-1F、MT-1X、MT-2A和ZnT-1基因mRNA表达增高。     

Colorectal Cancer: Chemopreventive Role of Curcumin and Resveratrol

Colorectal cancer (CRC) is a second leading cause of cancer deaths in the Western world. Currently there is no effective treatment except resection at a very early stage with or without chemotherapy. Of various epithelial cancers, CRC in particular has a potential for prevention, since most cancers follow the adenoma-carcinoma sequence, and the interval between detection of an adenoma and its progression to carcinoma is usually about a decade. However no effective chemopreventive agent except COX-2 inhibitors, limited in their scope due to cardiovascular side effects, have shown promise in reducing adenoma recurrence. To this end, natural agents that can target important carcinogenic pathways without demonstrating discernible adverse effects would serve as ideal chemoprevention agents. In this review, we discuss merits of two such naturally occurring dietary agents—curcumin and resveratrol—for chemoprevention of CRC.     

Inhibition of Cell Growth and VEGF Expression in Ovarian Cancer Cells by Flavonoids

Dietary flavonoids have been shown to be protective against various types of cancers. Here we studied the effects of 12 different flavonoids and other substances on cell proliferation and VEGF expression in human ovarian cancer cells, OVCAR-3. Cell growth was determined to pinpoint the best time for drug treatment. By LDH assay, no cytotoxicity was observed for OVCAR-3 cells with all 12 chemicals except mevinolin. Six flavonoids, including apigenin, taxifolin, luteolin, quercetin, genistein, and kaempferol, were shown to inhibit the ovarian cancer cell growth in a dose-dependent manner. From both RT-qPCR and ELISA results, all flavonoids have shown varied degrees of inhibition in VEGF expression. Taxifolin and naringin showed the least inhibition effect. They both lack a double bond in the second ring structure that may be important in inhibiting VEGF expression. The rank order of VEGF protein secretion inhibitory potency was genistein > kaempferol > apigenin > quercetin > tocopherol > luteolin > cisplatin > rutin > naringin > taxifolin. Genistein, quercetin, and luteolin have shown strong inhibition to cell proliferation and VEGF expression of human ovarian cancer cells, and they show promising in the prevention of ovarian cancers.     

MACC1-Dependent Antitumor Effect of Curcumin in Colorectal Cancer

Metastasis is the main reason for the high mortality rate of colorectal cancer (CRC) patients. Despite the whole improvement in the field of cancer medicine, the treatment options for the patient in the late stages are very restricted. Our previous studies have elucidated metastasis-associated in colon cancer 1 (MACC1) as a direct link to metastasis formation. Therefore, we have aimed to inhibit its expression by using natural products, which are recently the center of most studies due to their low side effects and good tolerability. In this study, we have investigated the effect of one of the promising natural products, curcumin, on MACC1 expression and MACC1-induced tumor-promoting pathways. Curcumin reduced the MACC1 expression, restricted the MACC1-induced proliferation, and was able to reduce the MACC1-induced cell motility as one of the crucial steps for the distant dissemination of the tumor. We further showed the MACC1-dependent effect of curcumin on clonogenicity and wound healing. This study is, to our knowledge, the first identification of the effect of curcumin on the restriction of cancer motility, proliferation, and colony-forming ability by using MACC1 as a target.     

Reactivation of RASSF1A in Breast Cancer Cells by Curcumin

Reactivation of tumor suppressor genes (TSGs) involved in carcinogenesis by nontoxic bioactive food component represents a promising strategy for cancer chemoprevention. Recently, curcumin has been demonstrated to inhibit a bacterial DNA methyltransferase (M. Sss I) activity, induce global DNA hypomethylation in leukemia cells, and reactivate several hypermethylation silenced genes in lung and prostate cancer cells. Herein, we demonstrated that curcumin can enhance the mRNA and protein levels of ras-association domain family protein 1A (RASSF1A), 1 hypermethylation-silenced TSG, and decrease its promoter methylation in breast cancer cells. Mechanistic study demonstrated that curcumin can decrease DNA methylation activity of nuclear extract and downregulate the mRNA and protein levels of DNMT1 in MCF-7 cells, which may be associated with curcumin-induced disruption of NF-κB/Sp1 complex bound to the promoter region of DNMT1. Altogether, this study reveals a novel molecular mechanism of curcumin as a chemo-preventive agent for breast cancer through hypomethylation reactivation of RASSF1A.     

Synergetic Inhibition of Human Colorectal Cancer Cells by Combining Polyyne-Enriched Fraction from Oplopanax elatus and Irinotecan

Although irinotecan is an important anticancer drug for treating colorectal cancer, its dose-dependent side effects limited its clinical application. Thus, it’s important to develop low-toxic candidates to enhance the efficacy of irinotecan. Polyynes from genus Oplopanax were reported to possess potential anticancer effects on colorectal cancer. Hereby, we evaluated the synergetic inhibition of human colorectal cancer cells by combining polyyne-enriched fraction from Oplopanax elatus (the dichloromethane fraction of Oplopanax elatus, OED) and irinotecan. The results showed that 5 μg/ml of OED combined with 40 μM of irinotecan possessed significant synergetic inhibition on SW-480 cells with a combination index (CI) of 0.56. Besides, the percentage of apoptotic cells was significantly increased from 69.57% (40 μM of irinotecan) or 72.7% (5 μg/ml of OED) to 95.6% after treatment of OED combined with irinotecan (OCI), suggesting OED and irinotecan possess the synergistic apoptotic effect (P?P?相似文献   

肿瘤耐药基因（MDR1）表达的PCR定量分析

肺癌的耐药性是肺癌有效化疗的主要障碍，而耐药性的产生主要与ＭＤＲ１基因的过度表达导致其编码产物Ｐ－糖蛋白的增多有关。研究发现许多肿瘤在治疗前即有ＭＤＲ１ｍＲＮＡ水平的增高，在治疗后比例更高。因此检测肺癌的ＭＤＲ１基因表达情况对指导化疗非常重要。本文探索了一条对ＭＤＲ１基因进行定量分析的ＰＣＲ简单方法。此方法具有特异敏感的特点。并用此方法分析了２０例肺癌的ＭＤＲ１基因的表达情况。     

人Rb94基因联合γ-辐射抑制乳腺癌细胞生长的研究

目的 构建含有人类视网膜母细胞瘤94基因(Rb94基因)的腺病毒表达载体,研究其联合γ-辐射抑制人恶性肿瘤细胞生长的作用.方法 从人类胚胎中提取总RNA,经逆转录得到目的cDNA,用PCR技术扩增目的基因片段,将其连接入载体pENTRTM1A,然后经LR重组再转入到表达载体 pAd/CMV/V5-DESTTM中,对重组体进行鉴定.然后联合γ-辐射作用于乳腺癌细胞,观察细胞生长曲线的变化.结果 成功构建了含Rb94基因的腺病毒表达重组体并通过鉴定,联合γ-辐射作用于乳腺癌细胞后有更强的抑制效应.结论 本实验构建的人Rb94基因重组腺病毒表达质粒是成功的,与γ-辐射联合共同作用于肿瘤细胞有更强的抑制肿瘤细胞生长的作用.     

人肝细胞生长因子在CHO细胞中的高效表达

目的：建立高效表达人肝细胞生长因子（hHGF)的CHO细胞株。方法：将hHGF全长cDNA亚克隆到真核表达载体pTarget^TM上，构建出pTarget^TM-hHGF哺乳动物细胞表达质粒。通过该表达质粒和扩增质粒pSV2-dhfr对二氢叶酸还原酶基因缺失的CHO细胞（CHO－DG44）的共转染，经G418和MTX双筛选，建立稳定表达hHGF的CHO细胞株。该细胞株经MTX加压进行基因扩增，促使hHGF表达量显著提高。结果：获得的CHO细胞株hHGF表达量达到1．12μg/ml。结论；hHGF在CHO细胞中得到了高效表达，为制备hHGF开辟了新的途径。     

Polymethoxylated Flavones from Orange Peels Inhibit Cell Proliferation in a 3D Cell Model of Human Colorectal Cancer

Polymethoxylated flavones (PMFs) have been recognized to inhibit colorectal cancer proliferation through various mechanisms, however most of these studies have been performed on cells grown as monolayers that present limitations in mimicking the 3D tumor architecture and microenvironment. The main aim of this study was to investigate the anticancer potential of an orange peel extract (OPE) enriched in PMFs in a 3D cell model of colorectal cancer. The OPE was developed by supercritical fluid extraction and the anticancer effect was evaluated in HT29 spheroids cultures in a stirred-tank based system.

Results showed that OPE inhibited cell proliferation, induced cell cycle arrest (G2/M phase), promoted apoptosis, and reduced ALDH⁺ population on HT29 spheroids. The antiproliferative activity was significantly lower than that obtained for 2D model (EC50 value of 0.43 ± 0.02 mg/mL) and this effect was dependent on diameter and cell composition/phenotype of spheroids derived from different culture days (day 3 – 0.53 ± 0.05 mg/mL; day 5 – 0.55 ± 0.03 mg/mL; day 7 – 1.24 ± 0.15 mg/mL). HT29 spheroids collected at day 7 presented typical characteristics of in vivo solid tumors including a necrotic/apoptotic core, hypoxia regions, presence of cancer stem cells, and a less differentiated invasive front. Nobiletin, sinesentin, and tangeretin were identified as the main compounds responsible for the anticancer activity.     

肾和膀胱癌nm23基因表达的初步探讨

运用nm2 3基因的寡核苷酶探针 ,通过Northern印迹转移的方法 ,检测了 9例肾癌及 19例膀胱癌手术切除标本的nm2 3基因的表达产物mRNA的水平。结果显示 :⑴肾癌标本的nm2 3mRNA的水平增高(10 14± 3 4 6 ) ,与正常对照组相比 (3 4 6± 1 94 )差异有非常显著性 (t=3 172 ,P <0 0 1)。⑵膀胱癌标本nm2 3mRNA水平增高 (7 79± 3 4 1,n =19) ,与正常对照组相比 (3 0 8± 1 99,n =6 )差异有非常显著性 (t =2 90 4 ,P <0 0 1) ;膀胱肿瘤中不同的分期之间和肿瘤细胞的分级之间差异无显著性 (P >0 0 5) ,显示肾癌和膀胱癌中nm2 3基因mRNA表达量增高 ,且表达量与膀胱癌的分期和分级无关。     

人肺癌组织耐药基因（MDR1）表达及意义

应用ＰＣＲ定量分析技术对１０４例肺癌患者的ＭＤＲ１基因进行了前瞻性研究，结果发现，初治患者６９％（５５／８０）有ＭＤＲ１基因表达增高，而经过治疗的患者１００％（２４／２４）有ＭＤＲ１基因表达增高，其中小细胞肺癌（ＳＣＬＣ）的增高有显著意义（Ｐ＜０．０１），在没有经过治疗的患者，２１％（１８／８０）ＭＤＲ１表达量处于高水平，而经过治疗的患者，７５％（１８／２４）ＭＤＲ１表达量较高（Ｐ＜０．０１）。ＭＤＲ１基因高表达的患者化疗有效率明显低于ＭＤＲ１不表达或低表达的患者，其中以ＳＣＬＣ患者最为明显（Ｐ＜０．０１）。结果表明，检测肺癌患者尤其是ＳＣＬＣ患者的ＭＤＲ１基因的表达情况，对临床指导化疗非常重要。     

Effects of Selenomethionine on the Gene Expression Profile of Cloned Human Prostate Cancer Cells Representing a Phenotypic Continuum of Cancer Progression

The cutoff value of critical weight loss is still subject of discussion. In this pilot study, we investigated whether ≥5% weight loss in the past year predicts changes in nutritional status in patients with advanced cancer during treatment with palliative chemotherapy. In 20 patients with advanced cancer undergoing palliative (combination) chemotherapy, body weight, fat free mass (FFM), and cachexia were measured prior to the start and at 9 wk of treatment. History of weight loss was used to test differences in development of nutritional parameters during chemotherapy with use of independent sample t-tests. At baseline, 10 of 20 patients had lost ≥5% body weight during the past year and 5 patients were cachectic. The change in FFM in the first 9 wk of chemotherapy was significantly worse in patients with ≥5% weight loss compared to patients with <5% weight loss [mean difference: 3.5 kg (P = 0.001)]. Data also suggest that ≥5% weight loss predicts shorter survival (P = 0.03). We found that patients with ≥5% weight loss prior to chemotherapy have a deterioration in nutritional status during chemotherapy and may have a shorter survival. These results have to be confirmed in a larger study including a robust survival analysis.     

Synergistic Role of Curcumin With Current Therapeutics in Colorectal Cancer: Minireview

Despite the use of surgical resection and aggressive chemotherapy, nearly 50% of patients with colorectal carcinoma develop recurrent disease, highlighting the need for improved therapies. Curcumin (diferuloylmethane), the major active ingredient of turmeric (curcuma longa) with no discernable toxicity, has been shown to inhibit the growth of transformed cells and colon carcinogenesis at the initiation, promotion, and progression stages in carcinogen-induced rodent models. In a Phase I clinical trial, curcumin has been found to be extremely well tolerated and effective. In this review, we summarized the current status of our knowledge about the effectiveness of curcumin when given in combination with current chemotherapeutics such as 5-fluorouracil, oxaliplatin, and gemcitabine in treatment of gastrointestinal cancers with particular reference to colorectal cancer. Existing data suggest that curcumin in combination with chemotherapy is a superior strategy for treatment of gastrointestinal cancer.     

层粘素及其受体在人卵巢癌细胞中的表达和意义

目的探讨层粘素（laminin,LN）及其受体（laminin receptor, LNR）在人卵巢癌细胞黏附和转移中的作用。方法采用细胞黏附实验检测层粘素及其受体在5株卵巢癌细胞黏附中的作用;Boyden小室测定癌细胞侵袭能力;流式细胞技术检测层粘素及其受体在人卵巢癌细胞上的表达情况。结果抗层粘素及其受体抗体,可明显抑制人卵巢癌细胞的黏附作用,且随着稀释度的不同,其抗黏附能力各异。抗层粘素抗体侵袭力测定显示,A2780最弱,Skov-3最强,两者比较,差异有显著意义（P％0．01）。在5种卵巢癌细胞中,4株癌细胞有层粘素及其受体表达,l株癌细胞无表达。结论层粘素及其受体可通过诱导肿瘤细胞黏附和迁移,从而促进肿瘤细胞浸润和转移。     

异黄酮对前列腺癌细胞的激素受体基因表达的影响

[目的] 通过大豆异黄酮的活性物质染料木黄酮和大豆苷元抑制前列腺癌PG-3和LNCaP细胞增殖和对激素基因表达的影响，探讨大豆异黄酮治疗和预防前列腺癌的可能机制。[方法] 0、10、20、40、60、80和160μmol／L剂量组的染料木黄酮和大豆苷元处理前列腺癌细胞，细胞存活率用MTT方法检测，α雌激素受体(ERα)、β雌激素受体(ERβ)、雄激素受体(AR)和血管上皮生长因子(VEGF)等基因的mRNA表达用RT-PCR进行检测。[结果] 染料木黄酮和大豆苷元对PC-3、LNCaP细胞具有明显的抑制生长作用，在160μmol／L的浓度时，染料木黄酮、大豆苷元作用72h后，PC-3细胞的存活率分别为12．28％和44．88％，LNCaP细胞的存活率分别为25．48％和43．14％，其抑制效应具有时间和剂量依赖性，同时发现对．PC-3细胞的VEGF、ERα和ERβ基因表达下调，AR基因处理前后没有检测到；对LNCaP细胞的VEGF和AR基因表达下调，ERα和ERβ的表达并无影响。[结论] 大豆异黄酮能抑制前列腺癌细胞的增殖效应，存在时间和剂量效应关系，雌激素受体基因可能直接在大豆苷元抑制PC-3细胞的增殖中参与作用，而染料木黄酮抑制PC-3细胞和染料木黄酮及大豆苷元抑制LNCaP细胞可能主要是通过Akt通路影响VEGF和AR等基因而实现。