Regorafenib monotherapy as second-line treatment of patients with RAS-mutant advanced colorectal cancer (STREAM): an academic, multicenter, single-arm, two-stage, phase II study.

BACKGROUND: Maintaining angiogenesis inhibition and switching the chemotherapy backbone represent the current second-line therapy in patients with RAS-mutant metastatic colorectal cancer (mCRC). Regorafenib, an oral multikinase inhibitor, prolonged overall survival (OS) in the chemorefractory setting. MATERIALS AND METHODS: STREAM was an academic, multicenter, single-arm phase II trial, evaluating the activity of regorafenib in RAS-mutant mCRC, in terms of the rate of patients who were progression-free after 6 months from study entry (6mo-PF). Patients were pretreated with fluoropyrimidine, oxaliplatin, and bevacizumab. According to Simon's two-stage design, ≥18 patients 6mo-PF were needed in the overall population (N = 46). Secondary endpoints were safety, objective response rate (ORR), progression-free survival (PFS), and OS. Early metabolic response by [18F]2-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography ([18F]-FDG PET/CT) scan was an exploratory endpoint. EudraCT Number: 2015-001105-13. RESULTS: The number of patients 6mo-PF was 8/22 at the first stage and 14/46 in the overall population. The ORR was 10.9%, disease control rate was 54.6%, median (m)PFS was 3.6 months [95% confidence interval (CI) 1.9-6.7 months], mOS was 18.9 months (95% CI 10.3-35.3 months), and mPFS2 (from study entry to subsequent-line progression) was 13.3 months (95% CI 8.4-19.7 months). Long benefiter patients (>6mo-PF) significantly more often had a single metastatic site and lung-limited disease. No unexpected toxicity was reported. Grade ≥3 events occurred in 39.1% of patients, with hand-foot syndrome (13%), fatigue, and hyperbilirubinemia (6.5%) occurring mostly. Baseline metabolic assessment was associated with OS in the multivariate analysis, while early metabolic response was not associated with clinical outcomes. CONCLUSIONS: The study did not meet its primary endpoint. However, regorafenib was well tolerated and did not preclude subsequent treatments. Patients with good prognostic features (single metastatic site and lung-limited disease) reported clinical benefit with regorafenib. The exploratory metabolic analysis suggests that baseline [18F]-FDG PET/CT might be useful to select patients with a favorable outcome. A chemotherapy-free interval with regorafenib was associated with durable disease control in a selected group of patients with favorable clinical characteristics.

Pancreatic cancer detection and characterization: state of the art and radiomics.

Pancreatic ductal adenocarcinoma (PDAC) represents a challenge for a multidisciplinary oncology team. Diagnosis of PDAC remains challenging due to overlapping imaging features with benign lesions, notwithstanding great advances with computed tomography (CT) and magnetic resonance imaging (MRI). The term "Radiomics" has recently been introduced to define a mathematical process to extract countless quantitative features from medical images (including each diagnostic technique) with high throughput computing for diagnosis and prediction. This article is an updated overview of the imaging techniques to be employed during detection and characterization of pancreatic cancer diagnostic workup. Particularly, the limitations and advantages of the different imaging techniques are discussed, with a particular focus on functional imaging. This overview is the result of a self-study without protocol and registration number. Articles published in the English language from January 2000 to January 2021 were included. We analyzed 15 papers on radiomics. The possibility of functional imaging, such as CT, MRI, and radiomics has revolutionized pancreatic imaging, improving the detection and characterization of the lesions and allowing a prognosis related to radiological features, favoring the process of personalized medicine.

The value of lung scintigraphy in the management of airways foreign bodies in children.

AIM: A retrospective analysis was made to evaluate our experience in the management of tracheobronchial foreign bodies (TFB) in children (age

Central nervous system metastases in a cohort of metastatic breast cancer patients treated with trastuzumab.

BACKGROUND: Several analyses suggest an increase of brain metastases in HER2 over-expressing breast cancers treated with trastuzumab as compared to historical series of unselected patients. PATIENTS AND METHODS: We analyzed the incidence of central nervous system (CNS) metastases in 78 patients with HER2 over-expressing breast cancer treated with trastuzumab between July 2000 and June 2006 at the Oncology Department of University Federico II in Naples. We also characterized and compared patients with and without CNS involvement. RESULTS: The median follow-up was 35.3 months (95%CI 26.3-44); median overall survival was 56 months (95%CIs 46-nr); 5 patients showed CNS involvement before trastuzumab therapy while 31 developed CNS metastases during trastuzumab treatment. The median overall survival after CNS metastases was 25.4 months (95%CIs 15.2-nr); patients with CNS lesions showed worse overall survival than patients without CNS lesions (39.1 vs. 75 months, p = 0.005). CONCLUSION: CNS metastases are common events in patients with metastatic HER2 over-expressing breast cancer treated with trastuzumab; the impact on survival is detrimental even if survival after CNS metastases is longer than historical reports. Appropriate investigation of the role of CNS imaging screening and the prophylactic treatment strategies for CNS represents a priority research in this setting.

Ghrelin, motilin, insulin concentration in healthy infants in the first months of life: relation to fasting time and anthropometry.

AIMS: This study aimed to investigate: (i) the relation between fasting time and serum ghrelin, motilin and insulin concentrations and (ii) the correlations between these hormones and anthropometrical parameters of infants in the first 18 months of life. PATIENT AND METHODS: A cross-sectional study on 62 term infants was performed. Blood samples for hormonal assay were obtained at least 1 h after feeding. Weight, length and head circumference were recorded. Plasma ghrelin, motilin and insulin concentrations were determined by radioimmunoassay. RESULTS: Ghrelin and motilin had a significant direct correlation with fasting time (r = 0.447; P < 0.001 and r = 0.36; P = 0.004, respectively). We observed a negative influence of insulin on ghrelin levels (beta = -0.32; P = 0.036). Plasma ghrelin levels correlated significantly with age (r = 0.45, P < 0.001), weight (r = 0.31, P = 0.013), head circumference (r = 0.35, P = 0.006) and length (r = 0.39, P = 0.001). A significant correlation emerged between motilin and age (r = 0.45, P < 0.001), weight (r = 0.43, P = 0.001), head circumference (r = 0.47, P < 0.001) and length (r = 0.48, P < 0.001). CONCLUSIONS: Fasting influence on serum ghrelin concentration confirms the role of this hormone as a physiological meal initiator also in infancy. The correlation between ghrelin, anthropometrical parameters and age supports the hypothesis that this hormone could exert an important influence on growth in the first months of life. Considering motilin, age and weight might play a role in determining its secretion; motilin could be considered one of the numerous factors involved in long-term regulation of energy balance.

Serum ghrelin concentration and weight gain in healthy term infants in the first year of life.

OBJECTIVES: Ghrelin, a recently discovered hormone mainly secreted by the stomach, has several metabolic functions including regulation of food intake, energy homeostasis and body weight. There are few studies on this hormone in healthy infants during the first year of life. The aim of this study was to examine the correlations between ghrelin and weight gain in healthy term infants in the first year of life. METHODS: 104 healthy term infants aged 0 to 12 months were included in a cross-sectional study. Anthropometric measurements were assessed and mean weight gain was calculated. Serum ghrelin concentrations have been determined at least 3 hours after feeding by radioimmunoassay test. RESULTS: Ghrelin concentrations were correlated negatively to weight gain (r=-0.302; P=0.003) and positively to age (r = 0.412; P < 0.001), weight (r = 0.374; P < 0.001) and length (r=0.387; P<0.001). In breastfed infants a statistically significant negative correlation between ghrelin concentration and infant weight gain (r=-0.407; P=0.001) was observed, whereas in formula-fed infants this correlation was not statistically significant (r=-0.067; P=0.719). CONCLUSIONS: The negative correlation observed between ghrelin concentration and infant weight gain suggests that ghrelin might also play a role in the regulation of body weight in healthy infants with a physiologic energy balance. Further studies are needed to clarify how ghrelin might be involved in both short-term and long-term energy balance.

Targeting HER2 as a therapeutic strategy for breast cancer: a paradigmatic shift of drug development in oncology.

Targeted therapies are causing a dramatic change in cancer drug development. Trastuzumab, a humanized recombinant monoclonal antibody that recognizes the extracellular domain of HER2 trans-membrane protein, is among the first target-specific drugs that have been licensed for clinical use and its development represents a model of integration of new agents with classical treatment strategies. In preclinical models, trastuzumab has demonstrated a marked antiproliferative effect and a synergistic action with several chemotherapeutic agents. Monotherapy trials indicate that trastuzumab is active as a single agent in HER2 positive patients, is well tolerated, and is associated with preservation of quality of life (QoL). Furthermore, as first line therapy for metastatic breast cancer overexpressing HER2 receptor, the addition of trastuzumab to taxane-based chemotherapy significantly increased rate of objective response, time to disease progression and survival when compared with chemotherapy alone. Trastuzumab has shown important activity when used with many chemotherapeutic agents such as platinum salts, gemcitabine, vinorelbine and capecitabine and liposomal anthracyclines. Various trials are now ongoing to optimize the use of trastuzumab and to investigate its role in the adjuvant and in the neo-adjuvant setting.

Sentinel lymph node and breast cancer staging: final results of the Turin Multicenter Study.

AIM OF THE STUDY: Validation of the sentinel node (SN) technique in breast cancer by means of lymphoscintigraphy. MATERIALS AND METHODS: From December 1996 to January 1999 102 T1-T2 breast carcinoma cases were recruited in Turin. 99mTc-human serum albumin colloids were injected subdermally the day before surgery (mean activity, 5.2 +/- 2.5 MBq). Scintigraphic imaging was performed after injection. After identification of the SN during surgery by a hand-held gamma probe, the SN was excised and sent for histologic examination. SN histology was compared with that of other axillary nodes. RESULTS: The SN detection rate was 86.3%; among 88 cases with an identified SN, 37 (42%) had axillary metastases; the SN was metastatic in 35 cases (sensitivity, 94.6%); in 51.3% of pN+ cases (19/37) the SN was the only metastatic site. In two of the 53 negative SNs, SN histology did not match with that of the remaining axilla (negative predictive value, 96.2%; staging accuracy, 97.7%). CONCLUSIONS: Our results agree with those reported in the literature; however, except in clinical trials and experienced structures axillary lymph node dissection should not be abandoned when mandatory for prognostic purposes, considering that at present SN biopsy alone is not completely accurate for axillary staging, especially in the absence of an adequate learning period.

Membrane-induced folding of cecropin A.

Lipid membranes manifest a diverse array of surface forces that can fold and orient an approaching protein. To better understand these forces and their ability to influence protein function, we have used infrared spectroscopy with isotopic editing to characterize the 37-residue membrane-active antimicrobial polypeptide cecropin A as it approached, adsorbed onto, and finally penetrated various lipid membranes. Intermediate stages in this process were isolated for study by the use of internal reflection and Langmuir trough techniques. Results indicate that this peptide adopts well-ordered secondary structure while superficially adsorbed to a membrane surface. Its conformation is predominantly alpha-helical, although some beta structure is likely to be present. The longitudinal axis of the helical structure, and the transverse axes of any beta structure, are preferentially oriented parallel to the membrane surface. The peptide expands the membrane against pressure when it penetrates the membrane surface, but its structure and orientation do not change. These observations indicate that interactions between the peptide and deeper hydrophobic regions of the membrane provide energy to perform thermodynamic work, but separate and distinct interactions between the peptide and superficial components of the membrane are responsible for peptide folding. These results have broad implications for our understanding of the mechanism of action and the specificity of these antimicrobial peptides.

Antibacterial and antimembrane activities of cecropin A in Escherichia coli.

The ability of cecropin A to permeabilize and depolarize the membranes of Escherichia coli ML-35p bacteria has been compared to its bactericidal activity in an extension of earlier studies performed on synthetic lipid vesicle membranes (L. Silvestro, K. Gupta, J. H. Weiser, and P. H. Axelsen, Biochemistry 36:11452-11460, 1997). Our results indicate that differences in the concentration dependences of membrane permeabilization and depolarization seen in synthetic vesicles are not manifested in whole bacteria. The concentration dependences of both phenomena roughly correlate with bactericidal activity, suggesting that the bactericidal mechanism of cecropin A is related to membrane permeabilization.

Potential angiogenic role of platelet-activating factor in human breast cancer.

This study investigated the presence of platelet-activating factor (PAF) in the lipid extracts of 18 primary breast carcinomas and 20 control breast tissues. The amount of PAF detected in breast carcinomas was significantly higher than in controls. The mass spectrometric analysis of PAF-bioactive lipid extract from breast carcinomas showed the presence of several molecular species of PAF, including C16-alkylPAF, C18-lysophosphatidylcholine (LPC), C16-LPC, lyso-PAF, and C16-acylPAF. The amount of bioactive PAF extracted from breast specimens significantly correlated with tumor vascularization revealed by the number of CD34-and CD31-positive cells. As C16-alkylPAF was previously shown to induce angiogenesis in vivo, we evaluated whether the thin layer chromatography-purified lipid extracts of breast specimens elicited neoangiogenesis in a murine model of subcutaneous Matrigel injection. The lipid extracts from specimens of breast carcinoma containing high levels of PAF bioactivity, but not from breast carcinomas containing low levels of PAF bioactivity or from normal breast tissue, induced a significant angiogenic response. This angiogenic response was significantly inhibited by the PAF receptor antagonist WEB 2170. T47D and MCF7 breast cancer cell lines, but not an immortalized nontumor breast cell line (MCF10), released PAF in the culture medium. A significant in vivo neoangiogenic response, inhibited by WEB 2170, was elicited by T47D and MCF7 but not by MCF10 culture medium. These results indicate that an increased concentration of PAF is present in tumors with high microvessel density and that PAF may account for the neoangiogenic activity induced in mice by the lipid extracts obtained from breast cancer. A contribution of PAF in the neovascularization of human breast cancer is suggested.

Patients with Hashimoto's disease treated with L-thyroxine and followed for three years.

This study investigated the effectiveness of L-thyroxine management in 32 patients (mean age 11 years and 2 months; M:F = 1:5) with Hashimoto's disease followed annually for 3 years. One (8%) of the 12 patients, euthyroid at the onset, never required treatment; of the four (33%) who began treatment immediately, two were able to stop at the 1st or 2nd follow-up, whereas two had to continue. The other seven (59%) who did not begin treatment immediately had to start at the 1st, 2nd or 3rd follow-up. The findings in this small series suggest that hormone management may prove effective to a certain extent in euthyroid Hashimoto patients, primarily as a means of prevention.

Folding of beta-sheet membrane proteins: a hydrophobic hexapeptide model.

Beta-sheets, in the form of the beta-barrel folding motif, are found in several constitutive membrane proteins (porins) and in several microbial toxins that assemble on membranes to form oligomeric transmembrane channels. We report here a first step towards understanding the principles of beta-sheet formation in membranes. In particular, we describe the properties of a simple hydrophobic hexapeptide, acetyl-Trp-Leu5 (AcWL5), that assembles cooperatively into beta-sheet aggregates upon partitioning into lipid bilayer membranes from the aqueous phase where the peptide is strictly monomeric and random coil. The aggregates, containing 10 to 20 monomers, undergo a relatively sharp and reversible thermal unfolding at approximately 60 degreesC. No pores are formed by the aggregates, but they do induce graded leakage of vesicle contents at very high peptide to lipid ratios. Because beta-sheet structure is not observed when the peptide is dissolved in n-octanol, trifluoroethanol or sodium dodecyl sulfate micelles, aggregation into beta-sheets appears to be an exclusive property of the peptide in the bilayer membrane interface. This is an expected consequence of the hypothesis that a reduction in the free energy of partitioning of peptide bonds caused by hydrogen bonding drives secondary structure formation in membrane interfaces. But, other features of interfacial partitioning, such as side-chain interactions and reduction of dimensionality, must also contribute. We estimate from our partitioning data that the free energy reduction per residue for aggregation is about 0.5 kcal mol-1. Although modest, its aggregate effect on the free energy of assembling beta-sheet proteins can be huge. This surprising finding, that a simple hydrophobic hexapeptide readily assembles into oligomeric beta-sheets in membranes, reveals the potent ability of membranes to promote secondary structure in peptides, and shows that the formation of beta-sheets in membranes is more facile than expected. Furthermore, it provides a basis for understanding the observation that membranes promote self-association of beta-amyloid peptides. AcWL5 and related peptides thus provide a good starting point for designing peptide models for exploring the principles of beta-sheet formation in membranes.

Ectodermal dysplasia, primary hypothyroidism, and agenesis of the corpus callosum: variable expression of a single syndrome?

We present two unrelated children, a male and a female, with signs of ectodermal dysplasia, mental retardation, agenesis/ dysgenesis of the corpus callosum, and primary hypothyroidism. Reports of ectodermal dysplasia with CNS malformations or hypothyroidism or both are rare. We suggest that the condition we describe is a distinct entity within the large group of ectodermal dysplasia syndromes and that it has a variable clinical spectrum. As both males and females are affected and in a few reports some parents show minimal signs, the inheritance is likely to be autosomal dominant.

Paclitaxel plus doxorubicin in breast cancer: an Italian experience.

Based on preclinical data, phase I/II clinical trials were performed at Istituto Oncologico Romagnolo (IOR) Operative Units (Medical Oncology Departments of Forlì, Rimini, and Ravenna, Italy) to determine the efficacy and toxicity of sequential administration of doxorubicin followed by paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in the treatment of patients with advanced breast cancer that either had been previously untreated or that had relapsed after adjuvant therapy. In the phase I trial, 19 patients received bolus doxorubicin (50 mg/m2) followed after a 16-hour interval by paclitaxel (given at dose levels ranging from 130 to 250 mg/m2) by 3-hour infusion every 3 weeks, for a maximum of eight cycles. Paclitaxel doses were escalated in 30-mg/m2 increments if the maximum tolerated dose had not been reached in the previous dose level. Analysis of the 128 cycles assessable for toxicity demonstrated neutropenia (<500/microL) in 26 courses (20.3%), with no significant clinical events. No relevant clinical cardiotoxicity was observed. The paclitaxel maximum tolerated dose was not reached at the 250-mg/m2 dose level (no grade 3 or 4 extramedullary toxicity). In the IOR phase II trial, 13 patients were treated with fixed doses of both drugs (doxorubicin 50 mg/m2 and paclitaxel 220 mg/m2). Grade 4 neutropenia occurred in 39 of the 95 cycles, but was complicated by fever in only eight cycles (8.4%); three cycles required granulocyte colony-stimulating factor support. Peripheral neurotoxicity was the most common extramedullary side effect noted. Overall clinical responses in the IOR trials included 10 complete responses (31.3%) and 15 partial responses (46.9%), with an objective response rate of 78.1%. Comparison of these results with those obtained from a phase I trial using the opposite drug sequence showed comparable overall response rates, but IOR's sequence was associated with a higher complete response rate, as well as less frequent and less severe nonhematologic toxicity.

The concentration-dependent membrane activity of cecropin A.

Cecropin A is a naturally occurring, linear, cationic, 37-residue antimicrobial peptide. The precise mechanism by which it kills bacteria is not known, but its site of action is believed to be the cell membrane. To investigate the nature of its membrane activity, we examined the ability of cecropin A to alter membrane permeability in synthetic lipid vesicles and in Gram-negative bacteria. Cecropin A exerted distinctly different types of membrane activity depending on its concentration. In synthetic lipid vesicles, cecropin A dissipated transmembrane electrochemical ion gradients at relatively low concentrations, but much higher concentrations were required to release an encapsulated fluorescent probe. Cecropin A dissipated ion gradients whether or not the vesicle membranes contained anionic lipid, although the presence of anionic lipid dramatically increased peptide binding, and modestly increased the release of an encapsulated probe. Cholesterol did not prevent the dissipation of ion gradients by low concentrations of peptide, but it did inhibit release of the encapsulated probe by high concentrations of peptide. At the highest concentrations examined, cecropin A remained monomeric in solution, and did not aggregate, lyse, or otherwise alter vesicle size. In Gram-negative bacteria, cecropin A was potently bactericidal at concentrations which dissipated ion gradients in lipid vesicles, but much higher concentrations were required to cause the release of cytoplasmic contents. These findings point to the conclusion that cecropin A kills bacteria by dissipating transmembrane electrochemical ion gradients. They weigh against theories comparing the antimicrobial activity of cecropin A to the release of encapsulated probes from lipid vesicles, and against roles for cholesterol or anionic lipid headgroups in the selectivity of peptide action against bacteria.

Cytogenetics of pediatric central nervous system tumors.

A cytogenetic analysis was performed on short-term cultures of 43 previously untreated childhood central nervous system neoplasms of various histology. The cells were obtained from pediatric patients, none of whom had received therapy before karyotypic evaluation. Successful chromosome studies were performed on 24 tumors. The most commonly detected structural abnormalities involved chromosomes 1 and 17. Other structural chromosome abnormalities involved chromosomes 3, 6, 8, 9, 11, 12, and 20.

High-performance liquid chromatography/tandem mass spectrometry identification of salmon calcitonin degradation products in aqueous solution preparations.

Degradation impurities have been investigated, by means of high-performance liquid chromatography (HPLC)/ mass spectrometry, in commercial ampoules of salmon calcitonin, aqueous solution, stored for up to 2 years. Oxidation derivatives of the cysteine residues in positions 1 and 7, with cleavage of the disulfide bridge, were observed in all samples. Using our reversed-phase separation, these oxidation derivatives coeluted and presented an HPLC behavior identical to the derivative of salmon calcitonin with the disulfide bridge reduced. In a previous study this last compound was tentatively identified, without confirmation by mass spectrometry, as a major degradation product of salmon calcitonin in aqueous solution.

Involvement of a serine protease in the synthesis of platelet-activating factor by endothelial cells stimulated by tumor necrosis factor-alpha or interleukin-1 alpha.

It has been shown that production of platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) by endothelial cells (EC) stimulated with tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 alpha requires the synthesis of new proteins and is regulated by anti-proteinases. Here, we demonstrate that TNF-alpha and IL-1 alpha induce the expression by EC of a 34-kDa diisopropyl fluorophosphate-binding protein immunoprecipitated by an anti-human elastase antibody. This protein is released in the medium and cleaves the chromogenic substrate N-methoxysuccinyl- Ala-Ala-Pro-Val p-anilide, which is specific for elastase. The generation of this elastase-like protein seems to be important for the synthesis of PAF induced by TNF-alpha and IL-1 alpha, as suggested by the following observations: (a) it precedes the synthesis of PAF; (b) the inhibitors of serine protease and anti-human elastase antibody prevent the synthesis of PAF and the activation of 1-O-alkyl-2-lyso-glycerophosphocholine acetyl-CoA: acetyltransferase, which is a key enzyme of the PAF remodelling pathway; (c) elastase, at concentrations similar to that detectable in the medium of cytokine-activated EC, elicits a rapid synthesis of PAF by EC. High-performance liquid chromatography-tandem mass spectrometric analysis of bioactive PAF demonstrates that the molecular species produced after stimulation of EC with TNF-alpha, IL-1 alpha or elastase are similar, with a predominant synthesis of the alkyl species. These results indicate that TNF-alpha and IL-1 alpha stimulate the production of a serine protease which is critical in the activation of enzymes involved in PAF synthesis, suggesting the potential involvement of this mechanism in the regulation of EC functions.

A novel dimeric fluoropyrimidine molecule behaves as a remote precursor of 5-fluoro-2'-deoxyuridine in human erythrocytes.

A new dimeric fluoropyrimidine molecule (5-fluoro-2'-deoxyuridilyl-(5'-->3')-5-fluoro-2'-deoxy-5'-uridylic acid, Compound 1) was chemically synthesized from two separately deblocked 5-fluoro-2'-deoxyuridine mononucleotide moieties. Other structurally related nucleotides, 5-fluoro-2'-deoxyuridine-5'-diphosphate (FdUDP), 5-fluoro-2'-deoxyuridine-5'-triphosphate (FdUTP) and 5-fluoro-2'-deoxyuridine-3',5'-bisphosphate were also synthesized. The structures of all synthesized molecules were verified by mass spectrometric analyses and were consistent with expected molecular mass values. The metabolic patterns of conversion of Compound 1 were investigated both in human erythrocyte lysates and in intact erythrocytes previously loaded with this molecule according to a highly conservative encapsulation procedure. In hemolysates, Compound 1 was transformed to 5-fluoro-2'-deoxyuridine (FUdR) and to 5-fluorouracil (FU) through the intermediate formation of 5-fluoro-2'-deoxyuridine-5'-monophosphate (FdUMP). In intact red cells, Compound 1 still generated FUdR (and to a lesser extent FU), that was then released outside. The conversion pathway involves a phosphodiesterase-catalysed hydrolysis of Compound 1 into two FdUMP molecules, followed by further dephosphorylation to FUdR and by partial conversion to FU. Unlike hemolysates, Compound 1-loaded intact erythrocytes featured transient formation of FdUDP and FdUTP, both metabolites representing storage compounds for the final and sustained production of FUdR and FU. Therefore, human erythrocytes can behave as bioreactors ensuring the time-controlled production and delivery of the two powerful antitumor drugs FUdR and FU from encapsulated Compound 1. This new molecule and other compounds as well (e.g. FdUDP and FdUTP) can be viewed as useful pre-prodrugs, exploitable for intraerythrocytic bioconversion reactions.