Towards in vivo photomediated delivery of anticancer peptides: Insights from pharmacokinetic and -dynamic data.

An in vivo study of a photoswitchable cytotoxic peptide LMB040 has been undertaken on a chemically induced hepatocellular carcinoma model in immunocompetent rats. We analysed the pharmacokinetic profile of the less toxic photoform ("ring-closed" dithienylethene) of the compound in tumors, plasma, and healthy liver. Accordingly, the peptide can reach a tumor concentration sufficiently high to exert a cytotoxic effect upon photoconversion into the more active ("ring-open") photoform. Tissue morphology, histology, redox state of the liver, and hepatic biochemical parameters in blood serum were analysed upon treatment with (i) the less active photoform, (ii) the in vivo light-activated alternative photoform, and (iii) compared with a reference chemotherapeutic 5-fluorouracil. We found that application of the less toxic form followed by a delayed in vivo photoconversion into the more toxic ring-open form of LMB040 led to a higher overall survival of the animals, and signs of enhanced immune response were observed compared to the untreated animals.

C60 fullerene and its nanocomplexes with anticancer drugs modulate circulating phagocyte functions and dramatically increase ROS generation in transformed monocytes.

BACKGROUND: C60 fullerene-based nanoformulations are proposed to have a direct toxic effect on tumor cells. Previous investigations demonstrated that C60 fullerene used alone or being conjugated with chemotherapeutic agents possesses a potent anticancer activity. The main aim of this study was to investigate the effect of C60 fullerene and its nanocomplexes with anticancer drugs on human phagocyte metabolic profile in vitro. METHODS: Analysis of the metabolic profile of phagocytes exposed to C60 fullerene in vitro revealed augmented phagocytic activity and down-regulated reactive nitrogen species generation in these cells. Additionally, cytofluorimetric analysis showed that C60 fullerene can exert direct cytotoxic effect on normal and transformed phagocytes through the vigorous induction of intracellular reactive oxygen species generation. RESULTS: Cytotoxic action as well as the pro-oxidant effect of C60 fullerene was more pronounced toward malignant phagocytes. At the same time, C60 fullerenes have the ability to down-regulate the pro-oxidant effect of cisplatin on normal cells. These results indicate that C60 fullerenes may influence phagocyte metabolism and have both pro-oxidant and antioxidant properties. CONCLUSIONS: The antineoplastic effect of C60 fullerene has been observed by direct toxic effect on tumor cells, as well as through the modulation of the functions of effector cells of antitumor immunity.

MAPK/ERK signal pathway alterations in patients with Langerhans Cell Histiocytosis.

BACKGROUND: Clinical outcomes of Langerhans cell histiocytosis (LCH) are highly variable. It has been suggested that mitogen-activated protein kinase (MAPK) /extracellular signal-regulated kinases (ERK) signaling pathway might be activated in LCH patients. MATERIALS AND METHODS: We investigated KRAS, BRAF and NRAS mutations in patients with LCH by qPCR. RESULTS: Eight adult patients with LCH were treated at the National Cancer Institute, Kiev, Ukraine. Five patients received chemo plus radiation therapy and three patients received only chemotherapy, resp. (p < 0.05). All patients received LCH-I study protocol, six cycles in average. A BRAF c.1799T > A, p. V600E mutation was detected in 25% (2/8) of cases - 1 patient had an early relapse in 6 months, and 1 patient - stable disease. We did not find any BRAF, KRAS or NRAS mutations in three patients with late relapses (in 15, 24 and 46 months). Notably, KRAS mutations were not revealed in any LCH samples. The NRAS c.182A > G, p. Q61R mutation was found in two cases - one patient had LCH transformed to Hodgkins lymphoma, one patient had a refractory disease. Time to relapse rate (TTR) in patients with and without BRAF V600E gene mutation was 13 vs. 28 months, resp. (p < 0.05). TTR was 31.3 vs. 6.41 months in patients with absence and presence of NRAS mutation, p < 0.05. Multivariate analysis showed the presence of NRAS Q61R mutation was associated with poor event-free survival in LCH patients with HR of 6.1 (95% CI 0.2-12.6; p = 0.008). CONCLUSION: BRAF and NRAS mutations in LCH suggest a possibility of the disease being driven by the activation of the MAPK/ERK pathway. These oncogenic mutations provide new opportunities in understanding LCH pathogenesis and may be a potential target of therapy.Key words: Langerhans cell histiocytosis - mutations - prognostic factors - relapse - survival.

Sex-based differences in phagocyte metabolic profile in rats with monosodium glutamate-induced obesity.

The important component of obesity pathogenesis is inflammatory activation of innate immune cells within adipose tissue and in other body locations. Both the course of obesity and innate immune reactivity are characterized by sex-associated differences. The aim of the work was a comparative investigation of metabolic profiles of phagocytes from different locations in male and female rats with MSG-induced obesity. The administration of monosodium glutamate (MSG) caused obesity, with sex-associated differences, that was more severe in male rats. Obesity was associated with pro-inflammatory activation of CD14+ phagocytes from adipose tissue in female, but not in male rats, which was demonstrated by decreased phagocytosis activity along with increased ROS generation. Phagocytes from the peritoneal cavity and peripheral blood of obese female rats exhibited neutral metabolic profile, whereas those cells from obese male rats displayed a pro-inflammatory metabolic profile. Thus, the manifestation of obesity-induced inflammation was characterized by different patterns of metabolic profile of phagocytes in male and female rats. Identified immune cell characteristics expand our knowledge of obesity immunobiology and may help to develop more effective preventive and therapeutic interventions for obese patients of different sexes.

Immunological hallmarks of cis-DDP-resistant Lewis lung carcinoma cells.

PURPOSE: Tumor cell resistance to platinum-based chemotherapeutic agents is one of the major hurdles to successful cancer treatment with these drugs, and is associated with alterations in tumor cell immune evasion and immunomodulatory properties. Immunocyte targeting is considered as a relevant approach to fight drug-resistant cancer. In this study, immunological hallmarks of cis-DDP-resistant Lewis lung carcinoma cells (LLC/R9) were investigated. METHODS: Immunological features of LLC/R9 cells cultured in vitro in normoxic and hypoxic conditions as well as of those that were grown in vivo were examined. The expression of immunologically relevant genes was evaluated by RT-PCR. Tumor cell susceptibility to the macrophage contact tumoricidal activity and NK-mediated cytolysis was investigated in MTT test. TNF-α-mediated tumor cell apoptosis as well as macrophage phagocytosis, oxidative metabolism, and CD206 expression after the treatment with conditioned media from normoxic and hypoxic tumor cells were studied by flow cytometry. Flow cytometry was also used to characterize dendritic cell maturity. RESULTS: When growing in vitro, LLC/R9 were characterized by slightly increased immunosuppressive cytokine gene expression. Transition to in vivo growth was associated with the enhancement of transcription of these genes in tumor cells. LLC/R9 cells had lowered sensitivity to contact-dependent macrophage-mediated cytotoxicity and to the TNFα-mediated apoptosis in vitro. Conditioned media from hypoxic LLC/R9 cells stimulated reactive oxygen species generation and CD206 expression in non-sensitized macrophages. Acquisition of drug resistance by LLC/R9 cells was associated with their increased sensitivity to NK-cell-mediated cytolysis. Meanwhile, the treatment of LLCR/9-bearing animals with generated ex vivo and loaded with LLC/R9 cell-lysate dendritic cells (DCs) resulted in profoundly enhanced tumor metastasizing. CONCLUSION: Decreased sensitivity to macrophage cytolysis, polarizing effect on DCs maturation along with increased susceptibility to NK-cell cytotoxic action promote extensive local growth of chemoresistant LLC/R9 tumors in vivo, but hamper their metastasizing.