Biomedical subjects

Alessandra Calabrese

Publications and source records attributed to Alessandra Calabrese.

7 recordsLinked to original sources

PubMed2026

Transcriptomic signatures of mind-body transformations therapy in breast cancer: Downregulation of the interferon signaling pathway.

BACKGROUND: Growing evidence has shown that Mind-Body Transformations-Therapies (MBT-T) are able to modulate chronic inflammation, a well-known driver of cancer progression and drug resistance. In our previous work, we showed that a specific MBT-T protocol was able to reduce the release of various pro-inflammatory cytokines and chemokines in the sera of patients with breast cancer that completed adjuvant chemotherapy. Despite these clinical observations, the underlying molecular pathways through which this therapy exerts its effects remain unclear. This study aims to address this gap by characterizing genome-wide transcriptional profiles in patients undergoing a novel MBT-T protocol. METHODS: In this proof-of-concept study, patients with breast cancer were randomized into two groups: Group 1 (CTL), receiving standard follow-up care, and Group 2 (MBT-T), receiving standard follow-up plus biweekly MBT-T for 4 months. Blood samples were collected at different timepoints during the treatment. After RNA extraction from whole blood, gene expression was analyzed on twenty-one patients (CTL, n = 7; MBT-T, n = 14) using the nCounter® Human Inflammation Panel (249 genes). RESULTS: Patients undergoing MBT-T showed a significant global downregulation of inflammatory gene expression compared to the control group. The analysis revealed that the Interferon (IFN) signaling pathway was the most significantly suppressed, by downregulation of key genes such as IFIT1, IFIT3, IFI44, MX1 and OASL in the MBT-T group. CONCLUSIONS: MBT-T acts as a biological modulator capable of downregulating key inflammatory pathways at the transcriptional level. These findings provide a genomic basis for the clinical benefits of mind-body interventions in oncology.

Breast cancer↗

PubMed2006

Combination of active and inactive siRNA targeting the mitotic kinesin Eg5 impairs silencing efficiency in several cancer cell lines.

Gene silencing by RNA interference (RNAi) has proven to be a powerful tool for investigating gene function in mammalian cells. Combination of several short interfering RNA (siRNA) targeting the same gene is commonly used to improve RNA interference. However, in contrary to the well-described mechanism of RNAi, efficiency of single siRNA compared to pool remains poorly documented. We addressed this issue using several active and inactive siRNA targeting Eg5, a kinesin-related motor involved in mitotic spindle assembly. These siRNA, used alone or in combination, were tested for their silencing efficiency in several cancer cell lines. Here we show that presence of inactive Eg5 siRNA in a pool dramatically decreases knockdown efficacy in a cell line- and dose-dependent manner. Lack of inhibition by unrelated siRNA suggests that a competition may occur during siRNA incorporation into RNA-induced silencing complexes (RISCs) along with the target mRNA. Altogether, our results, which need to be confirmed with additional inactive siRNA, indicate that combination of siRNA may not increase but instead decrease silencing efficiency.

Base Sequence↗

PubMed2004

Differentiating the effects of Cx36 and E-cadherin for proper insulin secretion of MIN6 cells.

Connexins have been implicated in many cell functions, even though in most cases it is still unclear whether these functions may actually be mediated by other proteins that are secondarily affected by connexin changes. Secretory systems provide useful models in which to tackle this central question. Primary pancreatic beta-cells and insulin-producing lines are connected by gap junction channels made of Cx36. Using stable transfection of an antisense Cx36 cDNA, we have previously obtained clones of MIN6 cells that featured a markedly reduced expression of Cx36 and impaired insulin secretion. Here, we first show that this change also resulted in loss of E-cadherin and occludin expression, thus preventing the attribution of the secretory defects to a specific type of membrane protein. To investigate this question, we have now restored the expression of either Cx36 or E-cadherin in the Cx36 antisense-transfected cells. We show that a lentivirus-mediated transduction efficiently restored Cx36 expression in MIN6 cells and allowed for expression of variable levels of this protein. We further document that adequate but not excessive levels of Cx36 allowed for recover of normal insulin secretion in response to various secretagogues. Finally, we demonstrate that restoration of normal E-cadherin expression was not able to achieve the same secretory correction. The data demonstrate that Cx36, but not E-cadherin, is necessary to control specific steps of beta-cell secretion.

Animals↗

PubMed2003

Lentivirus-mediated transduction of connexin cDNAs shows level- and isoform-specific alterations in insulin secretion of primary pancreatic beta-cells.

We have generated novel lentiviral vectors to integrate various connexin cDNAs into primary, non-dividing cells. We have used these vectors to test whether proper control of insulin secretion depends on a specific connexin isoform and/or on its level of expression. We have observed that transduced connexin32, connexin36 and connexin43 were expressed by primary adult beta-cells at membrane interfaces, were packed into typical gap junction plaques and formed functional channels that allowed a variable coupling, depending on the type and level of connexin expressed. The infected cells spontaneously reaggregated into three-dimensional pseudo-islet organs that could be maintained in culture. We have found that pseudo-islets made by cells transduced with either GFP- or connexin43-expressing lentivirus released insulin in response to various secretagogues similarly to controls. By contrast, pseudo-islets made by cells expressing connexin32, a connexin exogenous to pancreatic islets, or over-expressing connexin36, the endogenous islet connexin, featured a marked decrease in the secretory response to glucose. The data show: (1) that lentiviral vectors allow stable modulation of various connexin in primary, non-proliferating cells; (2) that specific connexin isoforms affect insulin secretion differently; and (3) that adequate levels of coupling via connexin36 channels are required for proper beta-cell function.

Animals↗

PubMed2003

Connexin 36 controls synchronization of Ca2+ oscillations and insulin secretion in MIN6 cells.

Cx36 is the predominant connexin isoform expressed by pancreatic beta-cells. However, little is known about the role of this protein in the functioning of insulin-secreting cells. To address this question, we searched for a cell line expressing Cx36 and having glucose-induced insulin secretion comparable to that of primary beta-cells. By evaluating Cx36 expression in MIN6, betaTC3, RIN2A, INS1, and HIT cell lines, which differ in their sensitivity to glucose, we found that wild-type MIN6 cells fit these requirements. Therefore, we stably transfected MIN6 cells with a cDNA coding for a Cx36 antisense sequence to study the role of Cx36 in these cells. Independent clones of MIN6 cells were obtained that had a markedly reduced Cx36 expression. Loss of Cx36 decreased functional gap junctional conductance in these clones. This alteration impaired the synchronization of glucose-induced [Ca(2+)](i) oscillations and insulin secretion in response to glucose, to secretagogues that increase [cAMP](i), and to depolarizing conditions. These data provide the first evidence that Cx36-made channels 1) mediate functional coupling in MIN6 cells, 2) provide for synchronous [Ca(2+)](i) oscillations, and 3) are necessary for proper insulin secretion in response to metabolizable and nonmetabolizable secretagogues.

Amphotericin B↗

PubMed2002

Cell coupling and Cx43 expression in embryonic mouse neural progenitor cells.

Embryonic neural progenitors isolated from the mouse striatal germinal zone grow in vitro as floating cell aggregates called neurospheres, which, upon adhesion, can be induced to differentiate into the three main cell types of the central nervous system (CNS), that is, astrocytes, neurons and oligodendrocytes. To study the possible role of connexins and junctional communication during differentiation of neural progenitors, we assessed cell-to-cell communication by microinjecting Lucifer Yellow into neurospheres at various times after adhesion. Cells located in neurospheres were strongly coupled, regardless of the differentiation time. Microinjections performed on the cell layers formed by differentiated cells migrating out of the neurosphere established that only astrocytes were coupled. These observations suggest the existence of at least three distinct communication compartments: coupled proliferating cells located in the sphere, uncoupled cells undergoing neuronal or oligodendrocytic differentiation and coupled differentiating astrocytes. A blockade of junctional communication by 18-beta-glycyrrhetinic acid (betaGA) reduced, in a concentration-dependent manner, the viability of undifferentiated neural progenitor cells. This effect appeared to be specific, inasmuch as it was reversible and that cell survival was not affected in the presence of the inactive analog glycyrrhyzic acid. Addition of betaGA to adherent neurospheres also decreased cell density and altered the morphology of differentiated cells. Cx43 was strongly expressed in either undifferentiated or differentiated neurospheres, where it was found both within the sphere and in astrocytes, the two cell populations that were dye coupled. Western blot analysis further showed that Cx43 phosphorylation was strongly increased in adherent neurospheres, suggesting a post-translational regulation during differentiation. These results point to a major role of cell-to-cell communication and Cx43 during the differentiation of neural progenitor cells in vitro.

Animals↗

PubMed2002

Connexins and secretion.

Connexin channels clustered at gap junctions are obligatory attributes of all macroscopic endocrine and exocrine glands investigated so far and also connect most types of cells which produce secretory products in other tissues. Increasing evidence indicates that connexins, and the cell-to-cell communications that these proteins permit, contribute to control the growth of secretory cells, their expression of specific genes and their differentiated function, including their characteristic ability to biosynthetize and release secretory products in a regulated manner. Since the previous reviews which have been published on this topic, several lines of evidence have been added in support of multiple regulatory roles of gland connexins. Here, we review this novel evidence, point to the many questions which are still open and discuss some interesting perspectives of the field.

Animals↗