Manuela Marra
Verified @iss.it
Istitutto superiore di Sanita
Scopus Publications
Scopus Publications
Giulia Errico, Maria Del Grosso, Michela Pagnotta, Manuela Marra, Maria Carollo, Marina Cerquetti, Elena Fogato, Elisabetta Cesana, Flaminia Gentiloni Silverj, Dorjan Zabzuni,et al.
MDPI AG
Ceftazidime–avibactam (CAZ-AVI) is an active antibiotic combination of a β-lactam–β-lactamase inhibitor against carbapenemase-producing Enterobacterales. Reports of resistance to CAZ-AVI other than metallo-β-lactamases have increased in recent years. The aim of this study was to analyze KPC-Klebsiella pneumoniae (KP) isolates resistant to CAZ-AVI from the intestinal carriage of hospitalized elderly patients in Italy, in February 2018–January 2020. Characterization of CAZ-AVI-resistant KP isolates, including MLST, resistome, virulome and plasmid content, was performed by WGS analysis. Out of six CAZ-AVI-resistant KP isolates, three belonged to ST101 and three to ST512; two isolates produced KPC-3 (both ST512), four had mutated KPC-3 (KPC-31, in ST101 and ST512, and KPC-46, both ST101). All CAZ-AVI-resistant KP isolates were multidrug-resistant and carried several resistance genes. The yersiniabactin ybt9 gene cluster was present in all ST101 isolates, while, in ST512 isolates, no virulence genes were detected. Several plasmids were detected: IncF was present in all isolates, as well as IncR and Col440 in ST101 and IncX3 in ST512 isolates. In conclusion, it is important to monitor the circulation of K. pneumoniae resistant to CAZ-AVI to prevent the spread of clones causing difficult-to-treat infections. The presence of mutated KPC-3 in high-risk K. pneumoniae clones resistant to CAZ-AVI in hospitalized patients deserves attention.
Maria Giufrè, Rita Cardines, Manuela Marra, Maria Carollo, Marina Cerquetti, and Paola Stefanelli
MDPI AG
Haemophilus influenzae invasive disease is a severe infection that needs rapid antibiotic therapy. The aim of the study was to perform and evaluate the serotype distribution, antibiotic susceptibility and molecular characteristics of 392 H. influenzae invasive isolates collected during 2017–2021 in Italy. The majority of isolates were NTHi (305/392, 77.8%), followed by Hib (49/392, 12.5%). Ampicillin resistance was frequently detected (85/392, 21.7%): 12.2% were β-lactamase producers (all blaTEM except one blaROB), 9.4% were β-lactamase-negative ampicillin-resistant (BLNAR), with mutations in the ftsI gene. Six isolates were resistant to ciprofloxacin, with substitutions in GyrA and ParC. An MLST analysis revealed the occurrence of international resistant clones, such as ST103 and ST14, highlighting the importance of molecular surveillance.
Margherita Montalbano Di Filippo, Arianna Boni, Paola Chiani, Manuela Marra, Maria Carollo, Lucrezia Cristofari, Fabio Minelli, Arnold Knijn, and Stefano Morabito
Frontiers Media SA
Free-living amoebae (FLA) are widely distributed protozoa in nature, known to cause severe eye infections and central nervous system disorders. There is growing attention to the potential role that these protozoa could act as reservoirs of pathogenic bacteria and, consequently, to the possibility that, the persistence and spread of the latter may be facilitated, by exploiting internalization into amoebae. Shiga toxin-producing strains of Escherichia coli (STEC) are zoonotic agents capable of causing serious diseases, such as hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS). Cattle represent the main natural reservoir of STEC, which are frequently found also in other domestic and wild ruminants, often without causing any evident symptoms of disease. The aspects related to the ecology of STEC strains in animal reservoirs and the environment are poorly known, including the persistence of these microorganisms within niches unfavorable to survival, such as soils or waters. In this study we investigated the interaction between STEC strains of serotype O157: H7 with different virulence gene profiles, and a genus of a wild free-living amoeba, Acanthamoeba sp. Our results confirm the ability of STEC strains to survive up to 20 days within a wild Acanthamoeba sp., in a quiescent state persisting in a non-cultivable form, until they reactivate following some stimulus of an unknown nature. Furthermore, our findings show that during their internalization, the E. coli O157 kept the set of the main virulence genes intact, preserving their pathogenetic potential. These observations suggest that the internalization in free-living amoebae may represent a means for STEC to resist in environments with non-permissive growth conditions. Moreover, by staying within the protozoa, STEC could escape their detection in the vehicles of infections and resist to the treatments used for the disinfection of the livestock environment.
Maria Giufrè, Giulia Errico, Monica Monaco, Maria Del Grosso, Michela Sabbatucci, Annalisa Pantosti, Marina Cerquetti, Michela Pagnotta, Manuela Marra, Maria Carollo,et al.
MDPI AG
The spread of carbapenemase-producing (CP) Enterobacterales is currently a worldwide concern, especially in the elderly. Twelve CP-E. coli isolated from rectal swabs of colonized inpatients aged ≥65 years from four hospitals in two Italian cities (Milan and Rome) were analyzed by whole genome sequencing (WGS) to obtain multi-locus sequence typing (MLST), identification of carbapenemase-encoding genes, resistome, plasmid content, and virulence genes. MLST analysis showed the presence of 10 unrelated lineages: ST410 (three isolates from three different hospitals in two cities) and ST12, ST38, ST69, ST95, ST131, ST189, ST648, ST1288, and ST1598 (one isolate each). Most isolates (9/12, 75%) contained a serine-β-lactamase gene (5 blaKPC-3, 2 blaKPC-2, and 2 blaOXA-181), while three isolates harbored a metallo-β-lactamase gene (two blaNDM-5 and one blaVIM-1). In most CP-E. coli, the presence of more than one plasmid was observed, with the predominance of IncF. Several virulence genes were detected. All isolates contained genes enhancing the bacterial fitness, such as gad and terC, and all isolates but one, fimH, encoding type 1 fimbriae. In conclusion, CP-E. coli clones colonizing elderly patients showed heterogeneous genetic backgrounds. We recommend strict surveillance to monitor and prevent the spread of successful, high-risk clones in healthcare settings.
A. Lo Presti, F. Coghe, A. Di Martino, S. Fais, R. Cappai, M. Marra, M. Carollo, M. Crescenzi, G. Orrù, G. Rezza and P. Stefanelli
INTRODUCTION
Multiple variants of SARS-CoV-2, since the end of 2020 have emerged in many geographical areas and are currently under surveillance worldwide highlighting the continuing need for genomic monitoring to detect variants previously not yet identified.
METHODS
In this study, we used whole-genome sequencing (WGS) and phylogenetic analysis to investigate A.27 lineage SARS-CoV-2 from Sardinia, Italy.
RESULTS
The Italian A.27 lineage genomes from Sardinia appeared related in a clade with genomes from France. Among the key mutations identified in the spike protein, the N501Y and the L452R deserve attention as considered likely vaccine escape mutations. Additional mutations were also here reported.
CONCLUSION
A combination of features could explain our data such as SARS-CoV-2 genetic variability, viral dynamics, the human genetic diversity of Sardinian populations, the island context probably subjected to different selective pressures. Molecular and genomic investigation is essential to promptly identify variants with specific mutations with potential impact on public health and vaccine formulation.
Mario Falchi, Lilian Varricchio, Fabrizio Martelli, Manuela Marra, Orietta Picconi, Agostino Tafuri, Gabriella Girelli, Vladimir N. Uversky, and Anna Rita Migliaccio
Elsevier BV
M Zingariello, L Sancillo, F Martelli, F Ciaffoni, M Marra, L Varricchio, R A Rana, C Zhao, J D Crispino, and A R Migliaccio
Springer Science and Business Media LLC
Gerald J. Spangrude, Daniel Lewandowski, Fabrizio Martelli, Manuela Marra, Maria Zingariello, Laura Sancillo, Rosa Alba Rana, and Anna Rita Migliaccio
Oxford University Press (OUP)
Abstract Splenomegaly is a major manifestation of primary myelofibrosis (PMF) contributing to clinical symptoms and hematologic abnormalities. The spleen from PMF patients contains increased numbers of hematopoietic stem cells (HSC) and megakaryocytes (MK). These MK express high levels of P-selectin (P-sel) that, by triggering neutrophil emperipolesis, may cause TGF-β release and disease progression. This hypothesis was tested by deleting the P-sel gene in the myelofibrosis mouse model carrying the hypomorphic Gata1low mutation that induces megakaryocyte abnormalities that recapitulate those observed in PMF. P-selnullGata1low mice survived splenectomy and lived 3 months longer than P-selWTGata1low littermates and expressed limited fibrosis and osteosclerosis in the marrow or splenomegaly. Furthermore, deletion of P-sel disrupted megakaryocyte/neutrophil interactions in spleen, reduced TGF-β content, and corrected the HSC distribution that in Gata1low mice, as in PMF patients, is abnormally expanded in spleen. Conversely, pharmacological inhibition of TGF-β reduced P-sel expression in MK and corrected HSC distribution. Spleens, but not marrow, of Gata1low mice contained numerous cKITpos activated fibrocytes, probably of dendritic cell origin, whose membrane protrusions interacted with MK establishing niches hosting immature cKITpos hematopoietic cells. These activated fibrocytes were not detected in spleens from P-selnullGata1low or TGF-β-inhibited Gata1low littermates and were observed in spleen, but not in marrow, from PMF patients. Therefore, in Gata1low mice, and possibly in PMF, abnormal P-sel expression in MK may mediate the pathological cell interactions that increase TGF-β content in MK and favor establishment of a microenvironment that supports myelofibrosis-related HSC in spleen.
E. Heideveld, F. Masiello, M. Marra, F. Esteghamat, N. Ya c , M. von Lindern, A. R. F. Migliaccio, and E. van den Akker
Ferrata Storti Foundation (Haematologica)
Expansion of erythroblasts from human peripheral blood mononuclear cells is 4- to 15-fold more efficient than that of CD34+ cells purified from peripheral blood mononuclear cells. In addition, purified CD34+ and CD34− populations from blood do not reconstitute this erythroid yield, suggesting a role for feeder cells present in blood mononuclear cells that increase hematopoietic output. Immunodepleting peripheral blood mononuclear cells for CD14+ cells reduced hematopoietic stem and progenitor cell expansion. Conversely, the yield was increased upon co-culture of CD34+ cells with CD14+ cells (full contact or transwell assays) or CD34+ cells re-constituted in conditioned medium from CD14+ cells. In particular, CD14++CD16+ intermediate monocytes/macrophages enhanced erythroblast outgrowth from CD34+ cells. No effect of CD14+ cells on erythroblasts themselves was observed. However, 2 days of co-culturing CD34+ and CD14+ cells increased CD34+ cell numbers and colony-forming units 5-fold. Proliferation assays suggested that CD14+ cells sustain CD34+ cell survival but not proliferation. These data identify previously unrecognized erythroid and non-erythroid CD34− and CD34+ populations in blood that contribute to the erythroid yield. A flow cytometry panel containing CD34/CD36 can be used to follow specific stages during CD34+ differentiation to erythroblasts. We have shown modulation of hematopoietic stem and progenitor cell survival by CD14+ cells present in peripheral blood mononuclear cells which can also be found near specific hematopoietic niches in the bone marrow.
Alister P. W. Funnell, Paolo Prontera, Valentina Ottaviani, Maria Piccione, Antonino Giambona, Aurelio Maggio, Fiorella Ciaffoni, Sandra Stehling-Sun, Manuela Marra, Francesca Masiello,et al.
American Society of Hematology
Key Points Elevation of HbF in 3 patients heterozygous for distinct 2p15-p16.1 syndrome microdeletions affecting BCL11A. Identification of novel, putative regulatory elements downstream of BCL11A that govern its expression in erythroid cells.
F. Censi, F. Tosto, G. Floridia, M. Marra, M. Salvatore, A. M. Baffico, M. Grasso, M. A. Melis, E. Pelo, P. Radice,et al.
Hindawi Limited
Since 2001 the Istituto Superiore di Sanità established a quality assurance programme for molecular genetic testing that covers four pathologies: Cystic Fibrosis (CF), Beta Thalassemia (BT), Fragile X Syndrome (FX), and Familial Adenomatous Polyposis Coli (APC). Since 2009 this activity is an institutional activity and participation is open to both public and private laboratories. Seven rounds have been performed until now and the eighth is in progress. Laboratories receive 4 DNA samples with mock clinical indications. They analyze the samples using their routine procedures. A panel of assessors review the raw data and the reports; all data are managed through a web utility. In 2010 the number of participants was 43, 17, 15, 5 for CF, BT, FX, APC schemes respectively. Genotyping results were correct in 96%, 98.5%, 100%, and 100% of CF, BT, FX, and APC samples, respectively. Interpretation was correct in 74%, 91%, 88%, and 60% of CF, BT, FX, and APC reports, respectively; however in most of them it was not complete but a referral to genetic counseling was given. Reports were satisfactory in more than 60% of samples in all schemes. This work presents the 2010 results in detail comparing our data with those from other European schemes.
Vincenzo Falbo, Manuela Marra, Federica Censi, Fabrizio Neri, Maria P. Foschini, Giovanna Floridia, and Domenica Taruscio
SAGE Publications
with a polymorphous low-grade adenocarcinoma (PLGA). The clinical information regarding these patients is summarized in Table I. Cases 1, 2 and 3 have been the subject of another study (10). Normal tissue was obtained from surgical margins uninvolved by the tumor and was available only for cases 1, 2 and 4; tissue from lymph node metastasis was obtained in case 4. Genomic DNA was extracted and analyzed by PCR to amplify part of the SSU0054 gene (a 150-bp fragment) using the following primers: forward: 5’-GACAGTATGTAGGAGGTGGCTATG-3’, region: 59482-59505; reverse: 5’-GGTTCCAGCAACATGAATGA-3’, region: 5963159612 (GenBank accession number NC_012925); as a positive control we used Streptococcus suis strain 3504 serotype 2, isolated in northen Italy, kindly provided by Annalisa Pantosti, Istituto Superiore di Sanità, Rome, Italy. This strain was isolated from pigs in areas with intensive swine industry. S. suis DNA was detected in tissue belonging to 4 of the 8 cases analyzed. Specifically, positive samples included i) the normal and tumor tissues of case 2 (2 and 2a), ii) the tumor tissue of case 3, iii) the normal salivary gland tissue of case 4 (4a), iv) the tumor tissue of case 8 (Tab. I). A BLAST analysis of all sequences showed high identity and homology (>97%), in comparison with the reference S. suis strain P1/7 serotype 2 (GenBank accession number AM946016), (6) to the 1221-bp folylpolyglutamate synthase SSU0054 gene. Folylpolyglutamate synthase belongs to the Mur ligase family that transfers glutamate to folylpolyglutamate (GenBank accession number CAR44188). Sequence alignment showed that all positive samples contained 3 synonymous single nucleotide polymorphisms (SNPs) at codon 10 CAA>CAG/p.Q10Q, codon 40 GTC>GTT/p.V40V, and codon 43 ACT>ACC/p. T43T; in addition, case 2 displayed 2 missense SNPs at codon 23 (A>G) and at codon 29 (G>A), which alter the codon triplets TAT>TGT/p.Y23C and TAT>TGT/p.G29E, respectively. Case 3 showed a missense SNP at codon 35 that alters the codon triplet GTT>ATT. Synonymous SNPs at codon 40 and 43 were also present in the control strain 3504, which displayed an additional SNP at codon 13, GTG>GTT/p.V13V. As shown by SNP analysis, the S. suis strain involved in this infection was similar to the Italian strain 3504 seroSalivary gland tumors (SGTs) are rare tumors of the head and neck with an incidence lower than 1/100.000 worldwide (1); they account for <0.5% of all malignancies and for less than 10% of head and neck tumors (1). The etiology of most SGTs is mostly unknown even if several risk factors have been postulated, among which exposure to ionizing radiation. Furthermore, the detection of high-risk HPV genotypes in 7 out of 9 parotid lesions analyzed suggests the possible involvement of this virus in the disease (2). A clear association has been established between Streptococcus bovis and colorectal carcinoma; Streptococcus suis detection has been reported only once in a case of early-stage colorectal carcinoma (3, 4). Human infection with S. suis is a zoonosis related to occupational exposure to pigs or pork products; it causes severe infections in humans, including meningitis, in countries with an intensive swine industry (5). Worldwide S. suis serotype 2 is the most frequently isolated and the capsule polysaccharide is considered the essential virulence factor. To our knowledge no studies have been performed to investigate a possible association between Streptococcus suis and malignant SGTs. In a previous study we detected by serendipity S. suis in one case of adenoid cystic carcinoma (ACC) with high grade transformation (hgACC) (the propositus case in the present study); in particular, DNA analysis revealed the presence of the putative folylpolyglutamate synthase SSU0054 gene of S. suis (6). This finding was the basis of our study aimed at screening 7 more cases of SGT to detect DNA positivity of S. suis in DNA extracted from paraffin-embedded samples of a total of 8 patients with SGTs, and to find a possible association between the pathogen and this disease. All cases, obtained from the Section of Anatomic Pathology of the Department of Hematology and Oncology of the University of Bologna at Bellaria Hospital, were diagnosed according to the criteria established in the WHO Blue Book (7) and the AFIP Atlas of Tumor Pathology (8). In addition, ACCs with highgrade transformation were characterized on the basis of the criteria established by Seethala et al (9). The series comprised 2 patients with ACCs with highgrade transformation (hgACC), 2 patients with ACCs, 3 patients with hybrid tumors composed of ACC and epithelial-myoepithelial cell carcinoma (EMCC), and 1 patient Streptococcus suis: a potential risk factor for salivary gland tumors?
Vincenzo Falbo
Spandidos Publications
Salivary gland tumours are rare tumours characterized by histopathologic complexity and a wide variety of morphologic features. Studies on genetic changes in different histological subtypes of salivary gland tumours are important to better understand molecular pathogenetic mechanisms and to identify diagnostic and prognostic markers. Data are even more scanty dealing with unusual subtypes of these tumours. The aim of the present study was to analyse two high grade transformation adenoid cystic carcinomas (hgACC) and one hybrid tumour in order to identify, by mutational and microsatellite analysis, genetic alterations in TP53, CDKN2A/ARF, RAS, BRAF, PTEN, MAPK2 and EGFR genes. The two hgACCs showed snps missense in RAS genes and alterations with allelic instability in CDKN2A/ARF; moreover, a double mutation in TP53 was detected in one case. The hybrid tumour showed alterations in CDKN2A/ARF gene and snps missense in NRAS genes. Our data suggest that CDKN2A/ARF pathway might be involved in pathogenesis of the salivary gland tumours analysed. Further molecular analyses of these very rare tumours are necessary to better understand the role of other genetic alterations detected in our study.
Stefania Meschini, Maria Condello, Annarica Calcabrini, Manuela Marra, Giuseppe Formisano, Pasquale Lista, Angelo De Milito, Elena Federici, and Giuseppe Arancia
Informa UK Limited
In our previous studies, the bisindolic alkaloid voacamine (VOA), isolated from the plant Peschiera fuchsiaefolia, proved to exert a chemosensitizing effect on cultured multidrug resistant (MDR) osteosarcoma cells exposed to doxorubicin (DOX). In particular, VOA was capable of inhibiting P-glycoprotein action in competitive way, thus explaining the enhancement of the cytotoxic effect induced by DOX on MDR cells. Afterwards, preliminary observations suggested that such an enhancement did not involve the apoptotic process but was rather due to the induction of autophagic cell death. The results of the present investigation demonstrate that the plant alkaloid VOA is an autophagy inducer able to exert apoptosis-independent cytotoxic effect on both wild type and MDR tumor cells. In fact, under treatment condition causing about 50% of cell death, no evidence of apoptosis could be revealed by microscopical observations, Annexin V-FITC labeling and analysis of PARP cleavage, whereas the same cells underwent apoptosis when treated with apoptosis inducers, such as doxorubicin and staurosporine. Conversely, VOA-induced autophagy was clearly evidentiated by electron microscopy observations, monodansylcadaverine staining, LC3 expression and conversion. These results were confirmed by the analysis of the modulating effects of the pretreatment with autophagy inhibitors prior to VOA administration. In addition, transfection of osteosarcoma cells with siRNA against ATG genes reduced VOA cytotoxicity. In conclusion, considering the very debated dual role of autophagy in cancer cells (protective or lethal, pro- or anti-apoptotic) our findings seem to demonstrate, at least in vitro, that a natural product able to induce autophagy can be effective against drug resistant tumors, either used alone or in association with conventional chemotherapeutics.
S. Meschini, M. Condello, M. Marra, G. Formisano, E. Federici, and G. Arancia
Elsevier BV
Enzo Agostinelli, Francesca Belli, Agnese Molinari, Maria Condello, Paola Palmigiani, Laura Dalla Vedova, Manuela Marra, Nikolaus Seiler, and Giuseppe Arancia
Elsevier BV
Marzia B. Gariboldi, Francesca Terni, Raffaella Ravizza, Stefania Meschini, Manuela Marra, Maria Condello, Giuseppe Arancia, and Elena Monti
Elsevier BV
Enzo Agostinelli, Francesca Belli, Laura Dalla Vedova, Manuela Marra, Pasqualina Crateri, and Giuseppe Arancia
Spandidos Publications
Hyperthermia is currently receiving widespread attention when associated with other therapeutic modalities, such as irradiation or chemotherapy, in the treatment of cancer. The occurrence of resistance to cytotoxic pharmacological agents in tumor cells, associated with several phenotypic alterations, is one of the major obstacles to successful anticancer chemotherapy. We investigated a new strategy to overcome multidrug resistance (MDR) cancer cells, using bovine serum amine oxidase (BSAO), which forms toxic products from spermine (H2O2 and aldehydes). The cytotoxicity of the products was evaluated in drug-sensitive (LoVo WT) and multidrug-resistant (LoVo DX) colon adenocarcinoma cells at 37 and 42 degrees C, using a clonogenic cell survival assay. Cytotoxicity was considerably enhanced at 42 degrees C. Both toxic species contributed to the thermal enhancement of cytotoxicity induced by BSAO and spermine. Cytotoxicity was eliminated in the presence of catalase and aldehyde dehydrogenase (ALDH). An interesting finding was that BSAO and spermine at <1 microM, which were non toxic at 37 degrees C, became cytotoxic at 42 degrees C and resemble thermosensitizers. Cell survival results and electron microscopy investigations suggest that, at 42 degrees C, LoVo DX cells are not resistant to the cytotoxic enzymatic oxidation products of spermine, as was already demonstrated in these cells at 37 degrees C. Moreover, microscopy modifications caused by both toxic products were more pronounced in LoVo DX than in LoVo WT cells, where morphological cytoplasmatic alterations were shown. Our findings suggest that hyperthermia combined with the enzymatic toxic oxidation products of spermine might be a promising anticancer strategy, mainly against MDR tumor cells.
Cecilia Bombelli, Giulio Caracciolo, Pietro Di Profio, Marco Diociaiuti, Paola Luciani, Giovanna Mancini, Claudia Mazzuca, Manuela Marra, Agnese Molinari, Donato Monti,et al.
American Chemical Society (ACS)
Mixed cationic liposomes composed by different ratios of dimyristoyl-sn-glycero-phosphatidylcoline (DMPC) and a cationic gemini surfactant have been studied by various physicochemical tools as vehicles for m-tetrahydroxyphenylchlorin (m-THPC), a photosensitizer used in photodynamic therapy. Entrapment and location of m-THPC within the lipid double layer have been evaluated by different techniques and the new formulations have been tested on a stabilized cell line from a human colon tumor, COLO206. A correlation between the physicochemical features of formulations and their efficiency as photosensitizers vector was found.
E. Agostinelli, G. Arancia, L. Dalla Vedova, F. Belli, M. Marra, M. Salvi, and A. Toninello
Springer Science and Business Media LLC
F. Luciani, M. Spada, A. De Milito, A. Molinari, L. Rivoltini, A. Montinaro, M. Marra, L. Lugini, M. Logozzi, F. Lozupone,et al.
Oxford University Press (OUP)
BACKGROUND
Resistance to antitumor agents is a major cause of treatment failure in patients with cancer. Some mechanisms of tumor resistance to cytotoxic drugs may involve increased acidification of extracellular compartments. We investigated whether proton pump inhibitors (PPIs), currently used in the anti-acid treatment of peptic disease, could inhibit the acidification of the tumor microenvironment and increase the sensitivity of tumor cells to cytotoxic agents.
METHODS
We pretreated cell lines derived from human melanomas, adenocarcinomas, and lymphomas with the PPIs omeprazole, esomeprazole, or pantoprazole and tested their response to cytotoxic drugs in cell death assays. We also evaluated extracellular and intracellular pH and vacuolar-H+-ATPase (V-H+-ATPase) expression, distribution, and activity in PPI-pretreated cells by using western blot analyses, immunocytochemistry, laser scanning confocal analysis, and bioluminescence assays. Finally, we evaluated human melanoma growth and cisplatin sensitivity with or without omeprazole pretreatment in xenografted SCID/SCID mice.
RESULTS
PPI pretreatment sensitized tumor cell lines to the effects of cisplatin, 5-fluorouracil, and vinblastine, with an IC50 value reduction up to 2 logs. PPI pretreatment was associated with the inhibition of V-H+-ATPase activity and increases in both extracellular pH and the pH of lysosomal organelles. PPI pretreatment induced a marked increase in the cytoplasmic retention of the cytotoxic drugs, with clear targeting to the nucleus in the case of doxorubicin. In in vivo experiments, oral pretreatment with omeprazole was able to induce sensitivity of human solid tumors to cisplatin.
CONCLUSION
Our results open new possibilities for the treatment of drug-resistant tumors through combination strategies based on the use of well-tolerated pH modulators such as PPIs.
Annarica Calcabrini, Stefania Meschini, Manuela Marra, Loredana Falzano, Marisa Colone, Barbara De Berardis, Luigi Paoletti, Giuseppe Arancia, and Carla Fiorentini
Elsevier BV
G. Arancia, A. Calcabrini, M. Marra, P. Crateri, M. Artico, A. Martone, F. Martelli, and E. Agostinelli
Springer Science and Business Media LLC
Annarica Calcabrini, Annarita Stringaro, Laura Toccacieli, Stefania Meschini, Manuela Marra, Marisa Colone, Giuseppe Arancia, Agnese Molinari, Giuseppe Salvatore, and Francesca Mondello
Elsevier BV
The search for innovative therapeutic approaches based on the use of new substances is gaining more interest in clinical oncology. In this in vitro study the potential anti-tumoral activity of tea tree oil, distilled from Melaleuca alternifolia, was analyzed against human melanoma M14 WT cells and their drug-resistant counterparts, M14 adriamicin-resistant cells. Both sensitive and resistant cells were grown in the presence of tea tree oil at concentrations ranging from 0.005 to 0.03%. Both the complex oil (tea tree oil) and its main active component terpinen-4-ol were able to induce caspase-dependent apoptosis of melanoma cells and this effect was more evident in the resistant variant cell population. Freeze-fracturing and scanning electron microscopy analyses suggested that the effect of the crude oil and of the terpinen-4-ol was mediated by their interaction with plasma membrane and subsequent reorganization of membrane lipids. In conclusion, tea tree oil and terpinen-4-ol are able to impair the growth of human M14 melanoma cells and appear to be more effective on their resistant variants, which express high levels of P-glycoprotein in the plasma membrane, overcoming resistance to caspase-dependent apoptosis exerted by P-glycoprotein-positive tumor cells.