Gut Bacteria of Columbia livia Are a Potential Source of Anti-Tumour Molecules

Objectives: The overall aim was to determine whether gut bacteria of Columbia livia are a potential source of antitumour molecules. Methods: Faecal and gut microbiota of Columbia livia were isolated, identified and conditioned media were prepared containing metabolites. Growth inhibition, lactate dehydrogenase cytotoxicity and cell survival assays were accomplished against cervical cancer cells. Next, liquid-chromatography mass spectrometry was conducted to elucidate the molecules present. Results: A plethora of bacteria from faecal matter and gastrointestinal tract were isolated. Selected conditioned media exhibited potent anticancer effects and displayed cytotoxicity to cervical cancer cells at IC50 concentration of 10.65 and 15.19 µg/ml. Moreover, cells treated with conditioned media exhibited morphological changes, including cell shrinking and rounding; indicative of apoptosis, when compared to untreated cells. A total of 111 and 71 molecules were revealed from these gut and faecal metabolites. The identity of 60 molecules were revealed including, dihydroxymelphalan. Nonetheless, 122 molecules remain unidentified and are the subject of future studies. Conclusion: These findings suggest that gut bacteria of Columbia livia possess molecules, which may have anticancer activities. Further in silico testing and/or high throughput screening will determine potential anticancer properties of these molecules.     

中草药抗癌的体外试验

以抑制细胞增殖为检测指标,用人体癌细胞株为供试体,比较了ＡｌａｍａｒＢｌｕｅＡｓｓａｙ（ＡＢＡ）检测方法,３Ｈ 胸苷标记（３Ｈ Ｔ）检测方法和５ 溴２ 脱氧尿苷标记（５ ＢｒｄＵ）酶联免疫检测方法的效果,对虎杖、穿心莲、仙鹤草和白花蛇舌草等４种中草药的抗癌活性进行了测试。结果显示ＡＢＡ作为一种检测细胞增殖的方法,具有快速、易操作和重复性好的特点。比较被测试的几种人体癌细胞株,以肠腺癌细胞株ＳＷ６２０对４种中草药提取物的反应最为敏感,而乳腺癌细胞株ＭＣＦ７的反应较弱。４种中草药提取物对肝癌细胞株ＨｅｐＧ２均有不同程度的明显的增殖抑制作用,而对肠腺癌细胞株ＬＳ１８０的增殖抑制作用只有在较高的浓度下才表现出来。仙鹤草和白花蛇舌草提取物对肠腺癌细胞株ＨＴ２９在实验浓度范围内无抑制作用,而仙鹤草提取物对肠腺癌另一细胞株ＳＷ６２０的增长抑制作用却很强,比其它３种中草药提取物的作用显著     

癌克利的抗癌作用实验研究

癌克利口服液是从中药提制的复方制剂，对小鼠肝癌Ｈ２２及小鼠白血病Ｐ３８８进行抑癌作用观察。经三次重复实验，结果表明对Ｈ２２及Ｐ３８８均显示明显的抑制效果，为进行临床应用和深入的基础研究提供了依据     

Synthesis of microtubule-interfering halogenated noscapine analogs that perturb mitosis in cancer cells followed by cell death

We have previously identified the naturally occurring non-toxic antitussive phthalideisoquinoline alkaloid, noscapine as a tubulin-binding agent that arrests mitosis and induces apoptosis. Here we present high-yield efficient synthetic methods and an evaluation of anticancer activity of halogenated noscapine analogs. Our results show that all analogs display higher tubulin-binding activity than noscapine and inhibit proliferation of human cancer cells (MCF-7, MDA-MB-231 and CEM). Surprisingly, the bromo-analog is ∼40-fold more potent than noscapine in inhibiting cellular proliferation of MCF-7 cells. The ability of these analogs to inhibit cellular proliferation is mediated by cell cycle arrest at the G₂/M phase, in that all analogs except 9-iodonoscapine, caused selective mitotic arrest with a higher efficiency than noscapine followed by apoptotic cell death as shown by immunofluorescence and quantitative FACS analyses. Furthermore, our results reveal the appearance of numerous fragmented nuclei as evidenced by DAPI staining. Thus, our data indicate a great potential of these compounds for studying microtubule-mediated processes and as chemotherapeutic agents for the management of human cancers.     

Quinoxaline 1,4-dioxides induce G2/M cell cycle arrest and apoptosis in human colon cancer cells

We have recently shown that quinoxaline 1,4-dioxide (QdNO) derivatives, namely 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide (DCQ), 2-benzoyl-3-phenyl-quinoxaline 1,4-dioxide (BPQ) and 2-acetyl-3-methyl-quinoxaline 1,4-dioxide (AMQ), suppress the growth of T-84 human colon cancer cells. Here we show that the growth-suppressive effects of QdNOs are due to their ability to induce cell cycle arrest and/or apoptosis. While AMQ blocked more than 60% of cells at the G₂/M phase without inducing apoptosis, DCQ caused a significant increase in apoptotic cells with no noticeable effects on the cycling of cells. Treatment with BPQ resulted in G₂/M cell cycle arrest and induction of apoptosis. With regard to the effects of QdNOs on molecules that regulate apoptosis and the G₂ to M transition, both BPQ and AMQ inhibited the expression of cyclin B, while DCQ significantly decreased the levels of Bcl-2 and increased Bax expression. Next, we investigated whether transforming growth factor-beta1 (TGF-1) and/or extracellular signal-regulated kinase (ERK) mediate the antiproliferative and apoptotic effects of QdNOs in colon cancer cells. Interestingly, the above QdNOs increased differentially total TGF1 mRNA expression and decreased TGF mRNA and ERK phosphorylation. None of these QdNOs induced changes in TGF-2 mRNA expression. The addition of a specific inhibitor of MEK greatly enhanced apoptosis in cells treated with DCQ, suggesting that the inhibition of ERK phosphorylation may explain, to an extent, the apoptogenic effects of this compound. Taken together, these findings provide insights into possible molecular mechanisms of growth inhibition by QdNOs that could aid in their evaluation for anticancer therapy.     

Structure-activity relationships of antineoplastic ring-substituted ether phospholipid derivatives

Purpose Previous studies have shown that alkylphosphocholines (APCs) exhibit strong antineoplastic activity against various tumour cell lines in vitro and in several animal models. The current study was designed to investigate the influence of cycloalkane rings on the antiproliferative activity of APCs against a panel of eight human and animal cell lines (PC3, MCF7, A431, Hela, PC12, U937, K562, CHO). Specifically, we explored the effect of the presence of 4-alkylidenecyclohexyl and cycloalkylidene groups in alkoxyethyl and alkoxyphosphodiester ether lipids, respectively. In addition, the haemolytic activity of the new ring-substituted ether phospholipids (EP) was evaluated.Methods Cells were exposed to various concentrations of the compounds for 72 h. The cytotoxicity was determined with the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] dye reduction assay. Similarly, red blood cells were distributed in 96-well microplates and treated with the test compounds at concentrations ranging from 100 to 6.25 M for 1 h. After centrifugation, the absorbance of the supernatants was measured at 550 nm.Results The majority of the compounds tested exhibited significant cytotoxic activity which depended on both the ring size and position with respect to the phosphate moiety, as well as the head group. Among the cycloalkylidene series the 11-adamantylideneundecyl-substituted N-methylmorpholino EP 13 was the most potent and exhibited broad-spectrum anticancer activity comparable to or superior to that of hexadecylphosphocholine (HePC). All the adamantylidene-substituted EPs were nonhaemolytic (concentration that exhibits 50% haemolytic activity, HC₅₀, >100 M). Furthermore, the cyclohexylidene-substituted analogues were more potent against the cell lines tested, with the exception of U937 and K562, than the cyclodecapentylidene-substituted compounds. Hydrogenation of the double bond in the cycloalkylidene-substituted EPs (compounds 14 and 15) resulted in improvement of anticancer activity. Among the 2-(4-alkylidenecyclohexyloxy)ethyl EPs, 2-(4-hexadylidenecyclohexyloxy)ethyl phosphocholine (22) possessed the highest broad-spectrum cytotoxic activity than all the other analogues of this series and was nonhaemolytic (HC₅₀ >100 M). In general, the 2-(4-alkylidenecyclohexyloxy)ethyl-substituted EPs were more active against the more resistant cell lines U937, K562 and CHO than HePC.Conclusions The presence of cycloalkane rings in the lipid portion of APCs reduces haemolytic effects compared to HePC and in several analogues results in improved antineoplastic activity.     

RNAi-mediated knockdown of pituitary tumor-transforming gene-1 (PTTG1) suppresses the proliferation and invasive potential of PC3 human prostate cancer cells

Pituitary tumor-transforming gene-1 (PTTG1) is a proto-oncogene that promotes tumorigenesis and metastasis in numerous cell types and is overexpressed in a variety of human tumors. We have demonstrated that PTTG1 expression was up-regulated in both human prostate cancer specimens and prostate cancer cell lines. For a more direct assessment of the function of PTTG1 in prostate tumorigenesis, RNAi-mediated knockdown was used to selectively decrease PTTG1 expression in PC3 human prostate tumor cells. After three weeks of selection, colonies stably transfected with PTTG1-targeted RNAi (the knockdown PC3 cell line) or empty vector (the control PC3 cell line) were selected and expanded to investigate the role of PTTG1 expression in PC3 cell growth and invasion. Cell proliferation rate was significantly slower (28%) in the PTTG1 knockdown line after 6 days of growth as indicated by an MTT cell viability assay (P < 0.05). Similarly, a soft agar colony formation assay revealed significantly fewer (66.7%) PTTG1 knockdown PC3 cell colonies than control colonies after three weeks of growth. In addition, PTTG1 knockdown resulted in cell cycle arrest at G1 as indicated by fluorescence-activated cell sorting. The PTTG1 knockdown PC3 cell line also exhibited significantly reduced migration through Matrigel in a transwell assay of invasive potential, and down-regulation of PTTG1 could lead to increased sensitivity of these prostate cancer cells to a commonly used anticancer drug, taxol. Thus, PTTG1 expression is crucial for PC3 cell proliferation and invasion, and could be a promising new target for prostate cancer therapy.     

Synthesis of some novel substituted purine derivatives as potential anticancer, anti-HIV-1 and antimicrobial agents

In search of novel purine antimetabolites, a series of 8-substituted methylxanthine derivatives was prepared in order to explore their in vitro anticancer, anti-HIV-1 and antimicrobial activities. The target compounds include: 8-[(3-substituted-4-oxo-thiazolidin-2-ylidene)hydrazino]-1,3-dimethyl (or 1,3,7-trimethyl)-3,7-dihydropurine-2,6-diones 5a-e, 8-[(3,4-disubstituted 2,3-dihydrothiazol-2-ylidene)hydrazino]-1,3,7-trimethyl-3,7-dihydropurine-2,6-diones 6a-d and 8-(5-amino-3-arylpyrazol-1-yl)-1,3-dimethyl- (or 1,3,7-trimethyl)-3,7-dihydropurine-2,6-diones 7a-g. The in vitro anticancer results revealed that compound 5d exhibited a super sensitivity profile towards leukemia K-562 with a GI(50) value of <0.01 microM. Compound 7c showed significant activity against colon cancer HCT-15 and renal cancer CAKI-1 (GI(50) values of 0.47 and 0.78 microM, respectively). Compound 7a displayed high activity against colon cancer HCT-15 (GI(50 )= 0.8 microM). The anti-HIV-1 results indicated that compound 6b displayed a good reduction of viral cytopathic effect (56.69%). The antimicrobial results showed that compound 5a was four times more active than ampicillin against P. aerugenosa (MIC =or< 25 microg/mL), compound 5b had twice the activity of ampicillin, while compounds 5d, 7c and 7f were equipotent to ampicillin. On the other hand, compound 7a was equipotent to ampicillin against P. vulgaris (MIC = 50 microg/mL).