Altered Elemental Distribution in Male Rat Brain Tissue as a Predictor of Glioblastoma Multiforme Growth : Studies Using SR-XRF Microscopy

Glioblastoma multiforme (GBM) is a particularly malignant primary brain tumor. Despite enormous advances in the surgical treatment of cancer, radio- and chemotherapy, the average survival of patients suffering from this cancer does not usually exceed several months. For obvious ethical reasons, the search and testing of the new drugs and therapies of GBM cannot be carried out on humans, and for this purpose, animal models of the disease are most often used. However, to assess the efficacy and safety of the therapy basing on these models, a deep knowledge of the pathological changes associated with tumor development in the animal brain is necessary. Therefore, as part of our study, the synchrotron radiation-based X-ray fluorescence microscopy was applied for multi-elemental micro-imaging of the rat brain in which glioblastoma develops. Elemental changes occurring in animals after the implantation of two human glioma cell lines as well as the cells taken directly from a patient suffering from GBM were compared. Both the extent and intensity of elemental changes strongly correlated with the regions of glioma growth. The obtained results showed that the observation of elemental anomalies accompanying tumor development within an animal’s brain might facilitate our understanding of the pathogenesis and progress of GBM and also determine potential biomarkers of its extension. The tumors appearing in a rat’s brain were characterized by an increased accumulation of Fe and Se, whilst the tissue directly surrounding the tumor presented a higher accumulation of Cu. Furthermore, the results of the study allow us to consider Se as a potential elemental marker of GBM progression

The role of Snail-1 and Cx43 in the regulation of glioblastoma multiforme cells resistance to temozolomide therapy

Oporność komórek nowotworowych na dotychczas stosowaną terapię stanowi główną przyczynę niepowodzeń w walce z glejakiem wielopostaciowym (GBM). Obecnie terapia pacjentów ze zdiagnozowanym GBM oparta jest o związek alkilujący-temozolomid (TMZ). Wiadomo, że zarówno zjawisko heterogenności fenotypowej komórek jak i proces podobny do przejścia epitelialno-mezenchymalnego (EMT) typu III mają wpływ na wykształcenie oporności komórek na leczenie TMZ. Ważnym białkiem biorącym udział w regulacji procesu EMT jest czynnik transkrypcyjny Snail-1, którego rolą jest hamowanie ekspresji genów związanych z fenotypem epitelialnym. Funkcje jak również poziom Snail-1 może regulować białko Cx43 co wskazuje na zaangażowanie tego białka w proces EMT. Celem niniejszej pracy było określenie powiązań między funkcjami białek Snail-1 i Cx43 a opornością komórek glejaka wielopostaciowego na terapię temozolomidem. Przeprowadzone analizy wskazują na cytotoksyczne działanie TMZ względem komórek glejaka wielopostaciowego. Jednocześnie komórki GBM wykształcają oporność na stosowany cytostatyk. Ponadto, wyniki analiz morfologii komórek, ich ruchliwości oraz potencjału transmigracyjnego jednoznacznie wskazują na zmianę fenotypu komórek w kierunku mezenchymalnym. Dodatkowe analizy pod kątem poziomu białek Snail-1 i Cx43 w komórkach GBM pokazały, iż temozolomid wpływa na podniesienie poziomu obu białek. Wnioskować więc można, że temozolomid może promować przejście podobne do EMT typu III podczas, którego komórki nabywają bardziej inwazyjny fenotyp. Uzyskane wyniki potwierdzają zaangażowanie procesu przejścia epitelialno-mezenchymalnego w zjawisko oporności komórek glejaka wielopostaciowego na obecnie stosowaną terapię temozolomidem. Głębsze poznanie oraz zrozumienie procesów wpływających na oporność komórek nowotworowych umożliwi opracowanie nowych efektywniejszych strategii terapeutycznych.Cancer cell resistance to the previously used therapy is the main reason for failure to combat glioblastoma multiforme (GBM). The current therapy for patients with GBM is based on alkylating agent­ temozolomide (TMZ). It is known that both phenotypic heterogeneity of cells and a process similar to type III epithelial-mesenchymal transition (EMT) impact TMZ resistance development in cells. Transcription factor Snail-1 is an important protein taking part in regulation of EMT process and is responsible for regulation of gene expression related to epithelial phenotype. Functions and level of Snail-1 can be regulated by Cx43 protein which suggests that the protein take part in EMT process. The aim of the study was to determine the link between functions of Snail-1 and Cx43 and temozolomide resistance in glioblastoma multiforme cells. The analyses conducted show cytotoxic activity of TMZ against glioblastoma multiforme cells. At the same time, GBM cells develop resistance to the cytostatic agent used. Moreover, results of analyses of cell morphology, cell motility and potential for transmigration indicate a clear change in phenotypes of cells into a mesenchymal phenotype. Additional analyses for level of Snail-1 and Cx43 in GBM cells showed that temozolomide increases the level of both the proteins. Therefore, it can be concluded that temozolomide may stimulate a transition similar to type III EMT during which cells acquire the more invasive phenotype

Experimental therapies in the treatment of melanoma

Czerniak jest nowotworem złośliwym skóry, który wywodzi się z komórek barwnikowych grzebienia nerwowego, czyli melanocytów. Charakteryzuje się szybką dynamiką wzrostu, a jego wykrycie we wczesnym stadium daje ponad 90% szans na przeżycie. W Polsce występuje stosunkowo rzadko, w porównaniu z innymi krajami Europy, jednak co roku odnotowuje się systematyczny wzrost współczynnika zachorowalności. W niniejszej pracy na podstawie dostępnej literatury zostały przedstawione klasyczne metody leczenia, takie jak chirurgia, radioterapia i chemioterapia. Jednak głównym celem było omówienie eksperymentalnych metod leczenia czerniaka, które stanowią alternatywę dla klasycznej terapii. Obecnie prowadzi się badania eksperymentalne, z którymi wiąże się duże nadzieje i mogą one stać się w przyszłości skuteczne w walce z tym nowotworem. Innowacyjne metody terapeutyczne stosowane do leczenia czerniaka w stadium zaawansowanym wpływają na odpowiedź immunologiczną, bądź wewnątrzkomórkowe szlaki sygnałowe. W III fazie badań klinicznych, których celem jest ostateczne potwierdzenie skuteczności badanych leków, wykazano pozytywne działanie ipilimumabu (przeciwciało anty-CTLA-4) oraz wemurafenibu (inhibitor białka BRAF), które przyczyniły się do wydłużenia życia chorych. W Stanach Zjednoczonych do leczenia czerniaka przerzutowego zastosowanie znalazły nowoczesne leki takie jak dabrafenib (inhibitor białka BRAF) i trametynib (inhibitor białka MEK). Duże nadzieje wiąże się z immunoterapeutykami (anty-PD-1, anty-PD-1L) oraz szczepionkami czerniakowymi, nad którymi prowadzone są obecnie badania. Interferon alfa, interleukina-2, które wykorzystywane są w praktyce klinicznej w monoterapii znalazły zastosowanie również w biochemioterapii, która łączy chemioterapię z cytokinami. Nadal prowadzi się badania z wykorzystaniem biochemioterapii do leczenia czerniaka w IV stopniu zaawansowania. Przyszłość w leczeniu czerniaka uogólnionego może stanowić, także terapia celowana obejmująca inhibitory kinaz, przeciwciała monoklonalne.Melanoma is a malignant skin tumor which originates from pigment cells of neural crest, called melanocytes. It is characterized by fast growth rate and its detection at an early stage gives over 90% chance of survival. In Poland it occurs relatively rarely in comparison to other countries of Europe. However, every year a systematic increase in the incidence is noted. In this work, on the basis of available literature, classical methods of treatment, like surgery, radiotherapy and chemotherapy have been presented. However, the main aim was to discuss experimental methods of treatment of melanoma, methods which are alternatives to a classical therapy. Currently, experimental studies are carried out, there are high hopes for them, and they may become effective in fighting against this cancer in the future. Innovative therapeutic methods used in treatment of melanoma in advanced stage affect the immune response or intracellular signaling pathways. In the III phase of clinical research, which aim to definitively confirm the effectiveness of studied medicines, a positive effect of ipilimumab (antibody anti-CTLA-4) and vemurafenib (protein inhibitor BRAF), which contributed to prolongation of life of patients. In the United States, modern medicines like dabrafenib (protein inhibitor BRAF) and trametinib (protein inhibitor MEK) were used in treatment of metastatic melanoma. There are high hopes for immunotherapeutics (anti-PD-1, anti-PD-1L) and melanoma vaccines, which are being researched contemporarily. Interferon alpha, interleukin 2, which are used in clinical practice in monotherapy, were also used in biochemotherapy which combines chemotherapy with cytokines. Researches are still carried out with the use of biochemotherapy in treatment of stage IV melanoma. The future in treatment of generalized melanoma may be also in targeted therapy which comprises kinase inhibitors, monoclonal antibodies

Altered elemental distribution in male rat brain tissue as a predictor of glioblastoma multiforme growth : studies using SR-XRF microscopy

Glioblastoma multiforme (GBM) is a particularly malignant primary brain tumor. Despite enormous advances in the surgical treatment of cancer, radio- and chemotherapy, the average survival of patients suffering from this cancer does not usually exceed several months. For obvious ethical reasons, the search and testing of the new drugs and therapies of GBM cannot be carried out on humans, and for this purpose, animal models of the disease are most often used. However, to assess the efficacy and safety of the therapy basing on these models, a deep knowledge of the pathological changes associated with tumor development in the animal brain is necessary. Therefore, as part of our study, the synchrotron radiation-based X-ray fluorescence microscopy was applied for multi-elemental micro-imaging of the rat brain in which glioblastoma develops. Elemental changes occurring in animals after the implantation of two human glioma cell lines as well as the cells taken directly from a patient suffering from GBM were compared. Both the extent and intensity of elemental changes strongly correlated with the regions of glioma growth. The obtained results showed that the observation of elemental anomalies accompanying tumor development within an animal's brain might facilitate our understanding of the pathogenesis and progress of GBM and also determine potential biomarkers of its extension. The tumors appearing in a rat's brain were characterized by an increased accumulation of Fe and Se, whilst the tissue directly surrounding the tumor presented a higher accumulation of Cu. Furthermore, the results of the study allow us to consider Se as a potential elemental marker of GBM progression

The influence of IONPs core size on their biocompatibility and activity in in vitro cellular models

Although the key factor affecting the biocompatibility of IONPs is the core size, there is a lack of regular investigation concerning the impact of the parameter on the toxicity of these nanomaterials. Therefore, such studies were carried out in this paper. Their purpose was to compare the influence of PEG-coated-magnetite NPs with the core of 5, 10 and 30 nm on six carefully selected cell lines. The proliferation rate, viability, metabolic activity, migration activity, ROS levels and cytoskeleton architecture of cells have been evaluated for specified incubation periods. These were 24 and 72-h long incubations with IONPs administered in two doses: 5 and 25 mu g Fe/ml. A decrease in viability was observed after exposure to the tested NPs for all the analyzed cell lines. This effect was not connected with core diameter but depended on the exposure time to the nanomaterials. IONPs increased not only the proliferation rate of macrophages-being phagocytic cells-but also, under certain conditions stimulated tumor cell divisions. Most likely, the increase in proliferation rate of macrophages contributed to the changes in the architecture of their cytoskeleton. The growth in the level of ROS in cells had been induced mainly by the smallest NPs. This effect was observed for HEK293T cells and two cancerous lines: U87MG (at both doses tested) and T98G (only for the higher dose). This requires further study concerning both potential toxicity of such IONPs to the kidneys and assessing their therapeutic potential in the treatment of glioblastoma multiforme