Injectable biodegradable polymeric system for preserving the active form and delayed-release of camptothecin anticancer drugs

One of the most challenging problems for camptothecin (CPT) family anticancer drugs (i.e. topotecan (TPT)) is the conversion of the active lactone ring into an inactive toxic carboxylate form under physiological conditions (pH = 7.4) in the body. Therefore, a simple platform based on thermosensitive PLLA-mPEG gels was designed to maintain TPT and CPT in lactone form, especially for brain tumor therapies. A high stabilization of the lactone species CPT and TPT within gel (>95%), efficient versatile homogenous drug loadings at 0.015%, 1%, and 10%, and the sustained-release of CPT and TPT over three weeks were all successful. The stabilization mechanism of drugs with gel was elucidated by ATR-FTIR, confocal and light microscopy. The cytotoxic efficacy of TPT in the PLLA-mPEG platform (PLLA-mPEG-TPT) was evaluated on LLC-1 and 4T1 cancer cell lines. In vivo, the administration of PLLA-mPEG-TPT to mice with breast tumors resulted in a significant reduction in tumor size and better survival percentages

Transcriptional splice variants of CD40 and its prognostic value in breast cancer

CD40 is an important tumor necrosis factor receptor (TNFR) family protein for the development of antitumor response against cancer cells, apart from its role in the regulation of the immune system as a costimulatory molecule. It is broadly expressed on the surface of immune cells and in diverse cancer types, including breast cancer. Here, we analyzed both CD40/CD40 ligand expression in breast cancer cells and tissues using public data sets and overall survival analysis in ungrouped breast cancer patients, as well as in the triple-negative breast cancer subtype. We detected CD40 gene expression along with its 3 different splice variants (variants 1-3), predominantly in the triple-negative subgroup of breast cancer cell lines. The results of the overall survival analysis showed that high CD40 gene expression, particularly in the triple-negative subgroup of breast cancer patients, is associated with better survival. In addition to the transcriptional levels of CD40 splice variants, investigation of protein levels of these variants will allow the categorization of breast cancer cells and reveal their potential as an immunotherapeutic target

Folic acid decoration of mesoporous silica nanoparticles to increase cellular uptake and cytotoxic activity of doxorubicin in human breast cancer cells

© 2021 Elsevier B.V.Breast cancer is the most frequent cancer among women and impacts over two million women each year. Although many different types of anticancer agents are available for breast cancer treatment, doxorubicin is one of the most widely used drug. However, doxorubicin related side effects such as heart failure and arrhythmia limit its usage. To overcome this limitation and improve doxorubicin effectiveness, pegylated liposomal doxorubicin formulation Doxil®/Caelyx® was developed. Although cardiotoxicity related side effects were reduced with liposomal doxorubicin formulations, a superior effect was not obtained and better approaches are still needed. In this study, it was aimed to develop a more effective doxorubicin formulation than Doxil® and to evaluate its anticancer activity. In order to achieve this goal, small sized mesoporous silica nanoparticles (MSNs) (~50 nm) were obtained, actively targeted with folic acid conjugation and loaded with doxorubicin. The obtained nanoparticles were fully characterized, conjugation was verified, and pH dependent drug release profile was shown. The nanoparticles’ anticancer activity was investigated in detail on the ZR-75-1 and T47-D breast cancer cell lines. Fluorescence microscope and flow cytometry studies revealed that the cellular uptake of doxorubicin could be enhanced with small sized MSNs. Moreover, folic acid conjugation made a tangible contribution to this effect. Additionally, similar results were also obtained in cytotoxicity studies on both cell lines. In conclusion, actively targeted small sized MSNs may be a promising approach to potentiate the anticancer effect of doxorubicin

Primary Tumor Resection For Initially Staged Iv Breast Cancer

Conventional therapy modalities for advanced breast cancer are problematic, whereas checkpoint blockade immunotherapy has been considered as a promising approach. This study aims to determine programmed death-ligand 1 (PD-L1) expression and methylation status of PD-L1 promoter in primary tumor tissue and metastatic foci of patients with stage IV breast cancer., Clinicopathological data and survival rates of 57 breast cancer patients, who were initially staged IV, and operated for intact tumors, were retrospectively analyzed. Immunohistochemical analysis of PD-L1 using 57 primary tumors, 33 paired metastatic lymph nodes, and 14 paired distant metastases was performed. Additionally, the methylation rate of the PD-L1 gene promoter region was determined with real-time polymerase chain reaction (PCR) analysis in 38 samples., Overall PD-L1 expression in primary tumors was 23.1% (12/52). PD-L1 positivity was reduced in lymph nodes by 15.2% (5/33) and in distant metastases by 21.4% (3/14). PD-L1 expression diverged between primary and metastatic foci in a subset of cases (18.2% for lymph node and 33.3% for distant metastasis). In general, the PD-L1 promoter was not methylated, and mean methylation rates were low (min. 0%–max. 21%). We observed no correlation between PD-L1 expression, promoter methylation, and survival., Neither the expression nor the methylation status of PD-L1 in patients, who were presented with stage IV breast cancer and operated for an intact primary tumor, had a statistically significant relation with survival. Discordance in PD-L1 expression between primary tumor and metastasis should be considered during pathological and clinical management of patients who would undergo checkpoint blockade therapy.PubMedWoSScopu

Evaluation of brain-targeted chitosan nanoparticles through blood-brain barrier cerebral microvessel endothelial cells

The blood-brain barrier (BBB) is the major problem for the treatment of central nervous system diseases. A previous study from our group showed that the brain-targeted chitosan nanoparticles-loaded with large peptide moieties can rapidly cross the barrier and provide neuroprotection. The present study aims to determine the efficacy of the brain-targeted chitosan nanoparticles' uptake by the human BBB cerebral microvessel endothelial cells (hCMECs) and to investigate the underlying mechanisms for enhanced cellular entry. Fluorescently labelled nanoparticles either conjugated with antibodies recognising human transferrin receptor (anti-TfR mAb) or not were prepared, characterised and their interaction with cerebral endothelial cells was evaluated. The antibody decoration of chitosan nanoparticles significantly increased their entry into hCMEC/D3 cell line. Inhibition of cellular uptake by chlorpromazine indicated that the anti-TfR mAb-conjugated nanoparticles were preferentially cell internalised through receptor-mediated endocytosis pathway. Alternatively, as primarily observed with control chitosan nanoparticles, aggregation of nanoparticles may also have induced macropinocytosis

Dual actions of the antioxidant chlorophyllin, a glutathione transferase P1-1 inhibitor, in tumorigenesis and tumor progression

Glutathione (GSH) and enzymes related to this antioxidant molecule are often overexpressed in tumor cells and may contribute to drug resistance. Blockade of glutathione transferases (GSTs) has been proposed to potentiate the efficacy of chemotherapeutic drugs in cancer. The aim of this study was to evaluate the effect of chlorophyllin that has antioxidant properties, and also interferes with the activity of GST P1-1, on breast cancers in vitro and in vivo. The in vivo studies were conducted using an N-methyl-N-nitrosourea (MNU)-induced chemical carcinogenesis model in laboratory rats. DNA damage, GST activity, and GSH levels were determined in liver and tumor tissues. Treatment with chlorophyllin increased the GSH levels in the liver and significantly decreased DNA damage in the blood, liver, and tumor tissues. Even though tumorigenesis was delayed in rats receiving chlorophyllin before MNU injections, once the tumors emerged, the progression of tumor appeared to be faster than in the animals that received the carcinogen only. Out of nine breast cell lines, GST P1-1 expression was detected in MCF-12A, MDA-MB-231, and HCC38. Concomitant incubation with chlorophyllin and docetaxel did not significantly affect cell proliferation and viability. Chlorophyllin displayed genoprotective effects that initially delayed tumorigenesis. However, once the tumors were established, it may act as a promoter that facilitates tumor growth, potentially by a mechanism independent of cell proliferation and viability. Our results underline the pros and cons of antioxidant treatment in cancer, even if it has a capacity to inhibit GST P1-1