Polyamine Metabolism as a Target for Growth Inhibition of Acanthamoeba culbertsoni

1987 ◽  
Vol 37 (3) ◽  
pp. 550-555 ◽  
Author(s):  
Sanjiv Gupta ◽  
Poornima Kishore ◽  
Onkar Prakash Shukla
1980 ◽  
Vol 188 (2) ◽  
pp. 491-501 ◽  
Author(s):  
L Alhonen-Hongisto ◽  
H Pösö ◽  
J Jänne

The anti-proliferative effects of 1,1′-[(methylethanediylidene)dinitrilo]diguanidine [methylglyoxal bis(guanylhydrazone)] and 1,1′-[(metHYLETHANEDIYLIDENE)dinitrilo]bis-(3-aminoguaNIDINE) HAVE BEEN STUDIED IN Ehrlich ascites carcinoma cells grown in suspension cultures. Both compounds are potent inhibitors of S-adenosyl-L-methionine decarboxylase from the tumour cells. In the presence of putrescine (but not in its absence), the inhibition produced by 1,1′-[methylethanediylidene)dinitrilo]bis-(3-aminoguanadine) was apparently irreversible, as judged by persistent depression of the enzyme activity even after extensive dialysis. The two compounds produced similar increases in adenosylmethionine decarboxylase activity, which resulted from a striking stabilization of the enzyme in cells grown in the presence of the drugs. The inhibitory effect of the two diguanidine derivatives on the synthesis of DNA and protein became evident after an exposure of 4–8 h. At that time, the only change seen in tumour polyamines in cells grown in the presence of the inhibitors was an increase in cellular putrescine. To find out whether the compounds initially interfered with the energy production of the tumour cells, the cultures were grown in the presence of uniformly labelled glucose, and the formation of lactate, as well as the oxidation of the sugar into CO2, were measured. The activation of glycolysis upon dilution of the tumour cells with fresh medium and the subsequent formation of labelled CO2 were siliar in control cells and in cells exposed to methylglyoxal bis(buanylhydrazone), 1,1′-[(methylethanediylidene)dinitrilo]bis-(3-aminoguanidine) or diaminopropanol. Only a marginal decrease in the cellular content of ATP was found in cells exposed to the inhibitors for 24 h. The diguanidine-induced growth inhibition was fully reversed by low concentrations of exogenous polyamines. However, the possibility remained that the reversal by polyamines was due to a decrease of intracellular diguanidine concentration. Our results indicate that the mode of action of 1,1′-[(methylethanediylidene)dinitrilo]bis-(3-aminoguanidine) is fully comparable to that of methylglyoxal bis(guanylhydrazone), as regards stabilization of adenosylmethionine decarboxylase and the appearance of growth inhibition in Ehrlich ascites cells. The data tend to support the view that both compounds apparently have an early anti-proliferative effect unrelated to polyamine metabolism.


1990 ◽  
Vol 136 (6) ◽  
pp. 985-992 ◽  
Author(s):  
T. A. Smith ◽  
T. A. Smith ◽  
J. H. A. Barker ◽  
M. Jung

1994 ◽  
Vol 92 (2) ◽  
pp. 350-355 ◽  
Author(s):  
Kensuke Miyamoto ◽  
Junichi Ueda ◽  
Satomi Takeda ◽  
Kazuko Ida ◽  
Takayuki Hoson ◽  
...  
Keyword(s):  

Author(s):  
Ahmad Z Al-Herrawy ◽  
Mohamed A Marouf ◽  
Mahmoud A. Gad

Genus Acanthamoeba causes 3 clinical syndromes amebic keratitis, granulomatous amebic encephalitis and disseminated granulomatous amebic disease (eg, sinus, skin and pulmonary infections). A total of 144 tap water samples were collected from Giza governorate, Egypt. Samples were processed for detection of Acanthamoeba species using non-nutrient agar (NNA) and were incubated at 30oC. The isolates of Acanthamoeba were identified to species level based on the morphologic criteria. Molecular characterization of the Acanthamoeba isolates to genus level was performed by using PCR. The obtained results showed that the highest occurrence percentage of Acanthamoeba species in water samples was observed in summer season (38.9%), then it decreased to be 30.6% in spring and 25% in each of autumn and winter. PCR analysis showed that 100% of 43 Acanthamoeba morphologically positive samples were positive by genus specific primer. In the present study eight species of Acanthamoeba can be morphologically recognized namely Acanthamoeba triangularis, Acanthamoeba echinulata, Acanthamoeba astronyxis, Acanthamoeba comandoni, Acanthamoeba griffini, Acanthamoeba culbertsoni, Acanthamoeba quina and Acanthamoeba lenticulata. In conclusion, the most common Acanthamoeba species in tap water was Acanthamoeba comandoni


Author(s):  
М.В. Филимонова ◽  
В.В. Южаков ◽  
А.С. Филимонов ◽  
В.М. Макарчук ◽  
Л.Н. Бандурко ◽  
...  

Цель исследования - изучение механизмов противоопухолевой активности ингибитора NOS Т1023 и оценка перспективности его дальнейшей разработки. Методика. В качестве опухолевой модели использована эпидермоидная КЛЛ, штамм которой получен из банка опухолевых материалов ФГБУ РОНЦ им. Н.Н. Блохина и поддерживался на самцах мышей C57BL6j. КЛЛ трансплантировали самцам мышей F1 (CBA´C57BL6j) путем подкожного введения 1,5×106 клеток карциномы в 0,1 мл суспензии на основе среды 199 в область латеральной поверхности правого бедра. Для сравнительной оценки противоопухолевой эффективности использовали ингибитор NOS под шифром Т1023, синтезированный в лаборатории радиационной фармакологии МРНЦ им. А.Ф. Цыба, и VEGF-ингибитор бевацизумаб (БВЗ). Животным первой опытной группы ежедневно, со 2 по 20 сутки вводили соединение Т1023 (60 мг/кг, в/б); второй опытной группы - трижды, на 2, 5 и 10 сут вводили БВЗ (12 мг/кг, в/б); третьей опытной группы - по этим схемам и в таких же дозах вводили и Т1023, и БВЗ (при комбинированном применении Т1023 вводили через 4 ч после введения БВЗ). Контрольным животным в качестве плацебо со 2 по 20 сутки вводили 0,9% раствор натрия хлорида (0,2 мл, в/б). Противоопухолевые эффекты оценивали, сравнивая размеры опухолевых узлов, длительность задержки роста и индекс торможения роста опухоли у контрольных и опытных животных. Гистологические методы исследования включали иммуноокрашивание на PCNA, CD31, пимонидазол и морфометрический анализ микроскопических изображений. Результаты сравнительных исследований показали, что соединение Т1023 и VEGF-ингибитор бевацизумаб (БВЗ) оказывают однонаправленное влияние на карциному легких Льюис (КЛЛ), сопровождающееся торможением роста и подавлением метастазирования неоплазии. Воздействие и Т1023, и БВЗ вызывало снижение содержания сосудов в перитуморальных зонах и в «горячих точках» ангиогенеза, усиливало гипоксию паренхимы КЛЛ и стимулировало апоптоз опухолевых клеток. При комбинированном применении Т1023 и БВЗ их антинеопластическая эффективность в отношении ингибирования ангиогенеза и девитализации опухолевых клеток соответствовала аддитивному действию. Заключение. Результаты позволяют предполагать, что основой противоопухолевой активности Т1023 является антиангиогенное действие и свидетельствуют о перспективности применения ингибиторов NOS в ангиостатической терапии солидных злокачественных новообразований в сочетании с имеющимися антинеоваскулярными средствами. The aim. Study of mechanisms of NOS inhibitor T1023 antitumor activity and estimation of its prospects for further development. Methods. Epidermoid Lewis lung carcinoma (LLC) from N.N. Blokhin NMRCO bank of tumor materials was used as a tumor model. Maintenance of tumor cell culture was provided by intramuscular injection of tumor cells suspension to C57BL6j mice every 14 days. Then LLC cells were transplanted to male F1 mice (CBA´C57BL6j) by subcutaneous injection of 1,5×106 cells in 0,1 ml of 199 medium into the lateral surface of the right hip. Comparative studies of antitumor efficacy were carried out using NOS inhibitor T1023, synthesized in the laboratory of radiation pharmacology of A.F. Tsyb MRRC, and VEGF inhibitor Bevacizumab (BVZ). Mice from the first experimental group were injected intraperitoneally (ip) with compound T1023 at dose 60 mg / kg from day 2 to 20; animals from the second experimental group were treated with BVZ at dose 12 mg / kg ip at days 2, 5 and 10; the third experimental group received T1023 in combination with BVZ according to these schemes and at the same doses (T1023 was administered 4 hours after administration of BVZ). Mice from the control group received 0,9% sodium chloride solution (0,2 ml, ip) as a placebo daily from 2 to 20 days. Antitumor effects were assessed by comparing the tumor size, duration of tumor growth delay and the index of tumor growth inhibition in control and experimental groups. Histological examination methods included immunostaining on PCNA, CD31, pimonidazole and morphometric analysis of microscopic images. Results. Comparative studies have shown that compound T1023 and VEGF inhibitor Bevacizumab (BVZ) have unidirectional effects on Lewis lung carcinoma (LLC), accompanied by growth inhibition and suppression of metastasis of neoplasia. The effect of both T1023 and BVZ caused a decrease in vascular content in the peritumoral zones and in the “hot spots” of angiogenesis, increased the hypoxia in the LLC parenchyma, and stimulated apoptosis of tumor cells. The combined use of T1023 and BVZ, caused the antineoplastic efficacy against inhibition of angiogenesis and devitalization of tumor cells which was estimated as additive effect. Conclusion. The results suggest that the basis of antitumor activity of T1023 is the anti-angiogenic effect and indicate the prospects of using NOS inhibitors in the angiostatic therapy of solid malignant neoplasms in combination with available anti-neovascular agents.


2018 ◽  
Vol 45 (2) ◽  
pp. 255-262
Author(s):  
A. Costas-Gil ◽  
M.J. Reigosa ◽  
A.M. Sánchez-Moreiras

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