Ferritin nanovehicle for targeted delivery of cytochrome C to cancer cells

In this work, we have exploited the unique properties of a chimeric archaeal-human ferritin to encapsulate, deliver and release cytochrome c and induce apoptosis in a myeloid leukemia cell line. The chimeric protein combines the versatility in 24-meric assembly and cargo incorporation capability of Archaeglobus fulgidus ferritin with specific binding of human H ferritin to CD71, the “heavy duty” carrier responsible for transferrin-iron uptake. Delivery of ferritin-encapsulated cytochrome C to the Acute Promyelocytic Leukemia (APL) NB4 cell line, highly resistant to transfection by conventional methods, was successfully achieved in vitro. The effective liberation of cytochrome C within the cytosolic environment, demonstrated by double fluorescent labelling, induced apoptosis in the cancer cells

Radiogenomics in clear cell renal cell carcinoma: correlations between advanced CT imaging (texture analysis) and microRNAs expression

Purpose: A relevant challenge for the improvement of clear cell renal cell carcinoma management could derive from the identification of novel molecular biomarkers that could greatly improve the diagnosis, prognosis, and treatment choice of these neoplasms. In this study, we investigate whether quantitative parameters obtained from computed tomography texture analysis may correlate with the expression of selected oncogenic microRNAs. Methods: In a retrospective single-center study, multiphasic computed tomography examination (with arterial, portal, and urographic phases) was performed on 20 patients with clear cell renal cell carcinoma and computed tomography texture analysis parameters such as entropy, kurtosis, skewness, mean, and standard deviation of pixel distribution were measured using multiple filter settings. These quantitative data were correlated with the expression of selected microRNAs (miR-21-5p, miR-210-3p, miR-185-5p, miR-221-3p, miR-145-5p). Both the evaluations (microRNAs and computed tomography texture analysis) were performed on matched tumor and normal corticomedullar tissues of the same patients cohort. Results: In this pilot study, we evidenced that computed tomography texture analysis has robust parameters (eg, entropy, mean, standard deviation) to distinguish normal from pathological tissues. Moreover, a higher coefficient of determination between entropy and miR-21-5p expression was evidenced in tumor versus normal tissue. Interestingly, entropy and miR-21-5p show promising correlation in clear cell renal cell carcinoma opening to a radiogenomic strategy to improve clear cell renal cell carcinoma management. Conclusion: In this pilot study, a promising correlation between microRNAs and computed tomography texture analysis has been found in clear cell renal cell carcinoma. A clear cell renal cell carcinoma can benefit from noninvasive evaluation of texture parameters in adjunction to biopsy results. In particular, a promising correlation between entropy and miR-21-5p was found

Fenretinide induces autophagic cell death in caspase-defective breast cancer cells

The elimination of tumor cells by apoptosis is the main mechanism of action of chemotherapeutic drugs. More recently, autophagic cell death has been shown to trigger a nonapoptotic cell death program in cancer cells displaying functional defects of caspases. Fenretinide (FenR), a synthetic derivative of retinoic acid, promotes growth inhibition and induces apoptosis in a wide range of tumor cell types. The present study was designed to evaluate the ability of fenretinide to induce caspase-independent cell death and to this aim we used the human mammary carcinoma cell line MCF-7, lacking functional caspase-3 activity. We demonstrated that in these cells fenretinide is able to trigger an autophagic cell death pathway. In particular we found that fenretinide treatment resulted in the increase in Beclin 1 expression, the conversion of the soluble form of LC3 to the autophagic vesicle-associated form LC3-II and its shift from diffuse to punctate staining and finally the increase in lysosomes/autophagosomes. By contrast, caspase-3 reconstituted MCF-7 cell line showed apoptotic cell death features in response to fenretinide treatment. These data strongly suggest that fenretinide does not invariably elicit an apoptotic response but it is able to induce autophagy when apoptotic pathway is deregulated. The understanding of the molecular mechanisms involved in fenretinide action is important for the future design of therapies employing this retinoid in breast cancer treatment

Reticulon1-C modulates protein disulphide isomerase function

Endoplasmic reticulum (ER) is the primary site for the synthesis and folding of secreted and membrane-bound proteins. Accumulation of unfolded and misfolded proteins in ER underlies a wide range of human neurodegenerative disorders. Hence, molecules regulating the ER stress response represent potential candidates as drug targets for tackling these diseases. Protein disulphide isomerase (PDI) is a chaperone involved in ER stress pathway, its activity being an important cellular defense against protein misfolding. Here, we demonstrate that human neuroblastoma SH-SY5Y cells overexpressing the reticulon protein 1-C (RTN1-C) reticulon family member show a PDI punctuate subcellular distribution identified as ER vesicles. This represents an event associated with a significant increase of PDI enzymatic activity. We provide evidence that the modulation of PDI localization and activity does not only rely upon ER stress induction or upregulation of its synthesis, but tightly correlates to an alteration in its nitrosylation status. By using different RTN1-C mutants, we demonstrate that the observed effects depend on RTN1-C N-terminal region and on the integrity of the microtubule network. Overall, our results indicate that RTN1-C induces PDI redistribution in ER vesicles, and concomitantly modulates its activity by decreasing the levels of its S-nitrosylated form. Thus RTN1-C represents a promising candidate to modulate PDI function

An approach to generating two zones of silence with application to personal sound systems

An application of current interest in sound reproduction systems is the creation of multizone sound fields which produce multiple independent sound fields for multiple listeners. The challenge in producing such sound fields is the avoidance of interference between sound zones, which is dependent on the geometry of the zone and the direction of arrival of the desired sound fields. This paper provides a theoretical basis for the generation of two zones based on the creation of sound fields with nulls and the positioning of those nulls at arbitrary positions. The nulls are created by suppressing low-order mode terms in the sound field expansion. Simulations are presented for the two-dimensional case which shows that suppression of interference is possible across a broad frequency audio range

Sequential valproic acid/all-trans retinoic acid treatment reprograms differentiation in refractory and high risk acute myeloid leukemia.

Epigenetic alterations of chromatin due to aberrant histone deacetylase (HDAC) activity and transcriptional silencing of all-trans retinoic acid (ATRA) pathway are events linked to the pathogenesis of acute myeloid leukemia (AML) that can be targeted by specific treatments. A pilot study was carried out in eight refractory or high-risk AML patients not eligible for intensive therapy to assess the biological and therapeutic activities of the HDAC inhibitor valproic acid (VPA) used to remodel chromatin, followed by the addition of ATRA, to activate gene transcription and differentiation in leukemic cells. Hyperacetylation of histones H3 and H4 was detectable at therapeutic VPA serum levels (>or=50 microg/mL) in blood mononuclear cells from seven of eight patients. This correlated with myelomonocytic differentiation of leukemic cells as revealed by morphologic, cytochemical, immunophenotypic, and gene expression analyses. Differentiation of the leukemic clone was proven by fluorescence in situ hybridization analysis showing the cytogenetic lesion +8 or 7q- in differentiating cells. Hematologic improvement, according to established criteria for myelodysplastic syndromes, was observed in two cases. Stable disease and disease progression were observed in five and one cases, respectively. In conclusion, VPA-ATRA treatment is well tolerated and induces phenotypic changes of AML blasts through chromatin remodeling. Further studies are needed to evaluate whether VPA-ATRA treatment by reprogramming differentiation of the leukemic clone might improve the response to chemotherapy in leukemia patients