Mechanisms mediating metabolic abnormalities in the livers of Ehrlich ascites tumor-bearing mice

A targeted nanoplatform co-delivering chemotherapeutic and antiangiogenic drugs as a tool to reverse multidrug resistance in breast cancer

Several obstacles are currently impeding the successful treatment of breast cancer, namely impaired drug accumulation into the tumor site, toxicity to normal cells and narrow therapeutic index of chemotherapy, multidrug resistance (MDR) and the metastatic spread of cancer cells through the blood and lymphatic vessels. In this regard, we designed a novel multifunctional nano-sized drug delivery system based on LyP-1 peptide-modified low-molecular-weight heparin-quercetin conjugate (PLQ). This nanosystem was developed for targeted co-delivery of multiple anticancer drugs to p32-overexpressing tumor cells and peritumoral lymphatic vessels, using LyP-1 peptide as active targeting ligand, with the aim to achieve a targeted combinatorial chemo/angiostatic therapy and MDR reversal. The cellular uptake of PLQ nanoparticles by p32-overexpressing breast cancer cells was significantly higher than nonfunctionalized nanoparticles. Besides, the anti-angiogenic activity of PLQ nanoparticles was proven by the effective inhibition of the bFGF-induced neovascularization in subcutaneous Matrigel plugs. More importantly, PLQ/GA nanoparticles with better targeting ability toward p32-positive tumors, displayed a high antitumor outcome by inhibition of tumor cells proliferation and angiogenesis. Immunohistochemistry and western blot assay showed that PLQ/GA nanoparticles significantly disrupted the lymphatic formation of tumor, and inhibited the P-glycoprotein (P-gp) expression in MCF-7 tumor cells, respectively. In conclusion, PLQ/GA nanoparticles provide a synergistic strategy for effective targeted co-delivery of chemotherapeutic and antiangiogenic agents and reversing MDR and metastasis in breast cancer.

STATEMENT OF SIGNIFICANCE

Herein, we successfully developed a novel amphiphilic nanomaterial, LyP-1-LMWH-Qu (PLQ) conjugate, consisting of a tumor-targeting moiety LyP-1, a hydrophobic quercetin (a multidrug resistance [MDR]-reversing drug) inner core, and a hydrophilic low-molecular-weight heparin (an antiangiogenic agent) outer shell for encapsulating and delivering a hydrophobic chemotherapeutic agent (gambogic acid). This versatile nanoplatform with multiple targeted features, i.e., dual chemo/angiostatic effects, destruction ability of the peritumoral lymphatic vessels, and reversal of MDR, resulted in a significantly stronger antitumor efficacy and lower toxic side effect than those of nontargeted nanoparticles and the free drug solution. Therefore, this versatile nanosystem might provide a novel insight for the treatment and palliation of breast cancer by targeted co-delivery of chemo/antiangiogenic agents and reversing MDR and metastasis.

Regression of murine Ehrlich ascites carcinoma using synthesized cobalt complex

Cisplatin as a chief chemotherapy has nephro-toxicity and so we have tried to develop a novel antitumor drug based on a combination of cobalt metal ion with an organic moiety. The antitumor activity of the complex was tested in vitro and in vivo against murine Ehrlich ascites carcinoma (EAC). Antioxidant capacity and nucleic acids content were determined. Cobalt(ii) diacetyl monoxime-2-hydrazinopyridine complex significantly diminished tumor load. It decreased the tumor proliferation rate and obviously increased the life span of EAC-bearing mice. It reversed the haematological parameters back towards normal, reduced liver enzymes and urea, and increased albumin and total protein. Antioxidant parameters levels were reversed towards normal. An assessment was conducted by comparing these results with those obtained using the standard drug, cisplatin. The results suggest that the cobalt complex can be considered as a potent anticancer agent as it showed appreciable antitumor activity in EAC-bearing mice that was almost analogous to that of the reference standard, cisplatin.

Effects of different extracts of the mushroom Agaricus blazei Murill on the hematologic profile of mice with Ehrlich tumor

The aim of this study was to investigate the effect of the mushroom Agaricus blazeii Murril (ABM) extracts on the hematological profile of Swiss mice bearing an Ehrlich solid tumor. Three fractions (total extract, polysaccharides, and supernatant) of ABM extracts obtained by four methods (ultrasonic or water bath, at pH 4 or pH 7) were administered to mice over 21 days. Polysaccharide solutions were analyzed by gas and liquid chromatography that showed both mannose and glucose concentrations. The method of extraction influenced the degree of glucose polymerization and the mannose/glucose relationship. The treatment with ABM supernatant at pH 7 and water bath was associated with reduced concentrations of leukocytes and lymphocytes and altered the percentage of CD4+ and CD8+ lymphocytes in Ehrlich tumor-bearing mice. The treatment with the ABM extract in water bath and ultrasound at pH 4 resulted in lower lymphocyte counts, regardless of tumor presence, and greater granulocyte values in mice with Ehrlich tumor than in controls. We concluded that different fractions and methods of extraction of A. blazei produced differing blood profiles in mice inoculated with the Ehrlich tumor.

Efeito do miriadenolídeo isolado de Alomia myriadenia (Asteraceae) sobre o tumor de Erlich ascítico no camundongo

Estudou-se atividade antineoplásica de um produto natural isolado de Alomia myriadenia (miriadenolídeo) no modelo do tumor de Ehrlich em camundongos. Dezoito fêmeas de camundongo Swiss foram inoculadas com 2x10(7) células viáveis de tumor de Ehrlich via intraperitoneal (0,3ml) e posteriormente distribuídas aleatoriamente em três grupos que receberam: grupo I (controle) - 0,3ml de solução de Hanks; grupo II - 31µg/kg de miriadenolídeo; e grupo III - 139µg/kg de miriadenolídeo. No oitavo dia de experimento, foram realizados exames hematológicos e perfil protéico sérico eletroforético. Coletou-se todo o líquido ascítico para avaliação do volume, aparência, pH, contagem de células viáveis e inviáveis, realização de esfregaços para contagem de células claras e escuras, leucócitos e avaliação das regiões organizadoras de nucléolos argentafins (AgNORs). Foram realizados exames macro e microscópicos do baço, fígado e rins e aspirado o conteúdo da medula óssea dos fêmures direito e esquerdo de cada animal para avaliação da relação mielóide:eritróide. Não houve diferença significativa no volume, pH, contagem de células viáveis e inviáveis entre os três grupos estudados, observando-se valores de 17,6 x 10(4) células tumorais viáveis no grupo III, 27,7 x 10(4) no grupo II e 21,1 x 10(4) no grupo I. As AgNORs apresentaram-se pequenas, com distribuição difusa e incontáveis no grupo I, e em menor quantidade no grupo III. Os animais do grupo III apresentaram a menor concentração protéica total sérica (4,7g/dl) (P<0,05) quando comparados com os do grupo II (5,3g/dl) e do grupo I (5,1g/dl). Os valores de albumina foram semelhantes nos três grupos (2,6g/dl), e as globulinas totais foram maiores (P<0,05) no grupo II (2,71g/dl) quando comparadas com os valores médios do grupo III (2,11g/dl) e semelhantes ao grupo I (2,43g/dl). Não houve diferença entre alfa e beta globulinas entre os três grupos estudados, porém as gamaglobulinas foram maiores (P<0,05) no grupo II (1,72g/dl) quando comparadas com as do grupo III (1,13g/dl). Com relação ao eritrograma e leucograma, não houve diferença significativa entre os grupos tratados. A relação mielóide:eritróide foi maior (P<0,05) no grupo III (1,40) quando comparada com a relação nos grupos I (0,92) e II (0,61). A contagem de reticulócitos também foi maior (P<0,05) (11,2) no grupo III, quando comparada com as dos grupos I (4,3) e II (3,6). Em todos os grupos, observou-se degeneração hepática.

Serine dehydratase expression decreases in rat livers injured by chronic thioacetamide ingestion

Serine dehydratase (SerDH) is a gluconeogenic enzyme involved in the catabolism of serine, which is regulated by the composition of their diet and their hormonal status in rats. This study examines how chronic injury caused to the liver of rats by the ingestion of thioacetamide (TAA) affects SerDH protein, mRNA levels, enzyme kinetics and its tissue location. After 97 days' oral intake of TAA, the activity of SerDH at all substrate concentrations assayed was about 60% lower than in controls. No significant differences in Km values were found between the treated group and controls. Immunoblotting and immunohistochemistry revealed a significant reduction in the level of SerDH protein in the livers of the treated rats. SerDH was detected specifically in the periportal zone of the hepatic acinus and this location did not change in response to TAA treatment. The level of SerDH mRNA, quantified by reverse transcription and polymerase chain reaction, was significantly lower in treated rats than in the controls. The present findings suggest that the SerDH expression is rendered to be down regulatory during chronic liver injury induced by TAA. These results enhance our understanding about the biochemical mechanisms implied in the control and integration of serine catabolism during liver injury in rat.