Does metformin reduce the risk of cancer in obesity and diabetes? A systematic review and meta-analysis.

AIM: To evaluate the effect of metformin on cancer incidence in subjects with overweight/obesity and/or prediabetes/diabetes. MATERIALS AND METHODS: We searched MEDLINE, Embase and CENTRAL for randomized controlled trials (RCTs) in adults with overweight/obesity and/or prediabetes/diabetes that compared metformin to other interventions for ≥24 weeks. Independent reviewers selected and extracted data including population and intervention characteristics and new diagnoses of cancer. We used the RoB 2.0 risk-of-bias tool and the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework to assess risk of bias and certainty of evidence. RESULTS: From 14 895 records after removal of duplicates, 27 trials were included, providing a total of 10 717 subjects in the metformin group and 10 003 in the control group, with 170 and 208 new cases of cancer, respectively. Using a random-effects model, the relative risk was 1.07 (95% confidence interval 0.87-1.31), with similar results in subgroup analyses by study duration or effect of control intervention on weight. Risk of bias in most studies was low, and no evidence of publication bias was found. Trial sequential analysis provided evidence that the cumulative sample size was large enough to exclude a significant effect of metformin on cancer incidence. CONCLUSIONS: Metformin did not reduce cancer incidence in RCTs involving subjects with overweight/obesity and/or prediabetes/diabetes.

Outcomes and Prognostic Factors of Patients with Metastatic Colorectal Cancer Who Underwent Pulmonary Metastasectomy with Curative Intent: A Brazilian Experience.

BACKGROUND: We aimed to identify clinicopathological and molecular features associated with progression-free survival (PFS) and overall survival (OS) after pulmonary metastasectomy for metastatic colorectal cancer in a retrospective cohort in Brazil. MATERIALS AND METHODS: We did a retrospective review of thoracic surgeries performed in a single large academic hospital in Brazil from January 1985 to September 2019. Demographics, previously described prognostic factors, and clinicopathological and molecular characteristics were abstracted. Univariate Cox regression was performed for each variable, and, when significant, data were dichotomized to provide clinically meaningful thresholds. RESULTS: Records from 698 patients were reviewed. Fifty-eight patients underwent pulmonary metastasectomy with curative intent. Of those, 53.4% had a single metastatic lesion. The median size of the largest lesion was 1.5 cm. Results of RAS, RAF, and mismatch repair testing and of cytokeratin 20 (CK20) and CDX2 testing were available for 13.8% and 58.6% of the sample, respectively. Median PFS was 14 months, median OS was 58 months, and 5-year survival was 49.8%. Unfavorable prognostic factors for OS included disease-free interval (DFI) <24 months, synchronous presentation, size of the largest lesion ≥2 cm, and loss of CK20 expression. Presenting with more than one lesion was prognostic for PFS but not for OS. CONCLUSION: In this Brazilian cohort, our findings corroborate existing data supporting DFI, synchronous presentation, and number and size of lesions as prognostic factors. Furthermore, we found that loss of CK20 expression may be associated with more aggressive disease and shorter OS. Additional molecular prognostic factors after pulmonary metastasectomy for colorectal cancer should be further explored. IMPLICATIONS FOR PRACTICE: This study consolidates disease-free interval, synchronous presentation, and number and size of lesions as clinically relevant data that may help guide therapy for patients with colorectal cancer and lung metastases who are candidates for curative-intent metastasectomy. Additionally, in this sample, lack of cytokeratin 20 expression in metastases was associated with shorter progression-free survival and overall survival, suggesting that biomarkers also may have a role in guiding therapy in this setting and that additional biomarkers should be further explored.

A quick UPLC-MS/MS method for therapeutic drug monitoring of abiraterone and delta(4)-abiraterone in human plasma.

Abiraterone acetate efficacy against prostate cancer is dependent on the circulating levels of abiraterone and its active metabolites, which present significant pharmacokinetic variability among patients. Thus, therapeutic drug monitoring can be performed to improve treatment outcomes. To support such studies, there are only a limited number of bioanalytical methods in current literature. This work presents a fast method to quantify abiraterone and D4A in plasma in 4 min by UPLC-MS/MS. Bioanalytical method validation was performed according to the recommendations of the US Food and Drug Administration. The method was linear within the range of 1-400 ng/ml for abiraterone and 0.2-20 ng/ml for D4A (r2 > 0.99). Based on the analysis of quality control samples at the lower limit of quantification, low, medium and high concentrations, the method was precise (CVabiraterone ≤ 9.72%; CVD4A ≤ 14.64%) and accurate (CVabiraterone 95.51-107.59%; CVD4A 98.04-99.89%). Application of the method to the quantification of abiraterone and D4A in 10 clinical samples revealed important variability in the conversion ratio of abiraterone to D4A (CV 90.85%). Considering the current literature, this is the fastest method to quantify abiraterone and D4A in plasma, allowing for optimization of the analytical routine.

Tropomyosin-Related Kinase Receptor and Neurotrophin Expression in Cutaneous Melanoma Is Associated with a Poor Prognosis and Decreased Survival.

OBJECTIVE: Normally, activation of tropomyosin-related kinase (TRK) receptors by neurotrophins (NTs) stimulates intracellular pathways involved in cell survival and proliferation. Dysregulation of NT/TRK signaling may affect neoplasm prognosis. Data on NT and TRK expression in melanomas are limited, and it is unclear whether NT/TRK signaling pathways are involved in the origin and progression of this neoplasm. METHODS: We examined whether NT/TRK expression differs across different cutaneous melanoma grades and subtypes, and whether it is associated with melanoma prognosis and survival. A cross-sectional study was performed in which the expression of TrkA, TrkB, nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) was analyzed by immunohistochemistry of 154 melanoma samples. We investigated NT/TRK expression associations with prognostic factors for melanoma, relapse-free survival (RFS), and overall survival (OS). RESULTS: Of the 154 melanoma samples, 77 (55.4%) were TrkA immunopositive, 81 (58.3%) were TrkB immunopositive, 113 (81.3%) were BDNF immunopositive, and 104 (75.4%) were NGF immunopositive. We found NT/TRK expression associated strongly with several clinical prognostic factors, including the tumor-node-metastasis stage (p < 0.001), histological subtype (p < 0.001), and Clark level (p < 0.05), as well as with a worse OS (p < 0.05 for all, except TrkB) and RFS (p < 0.05 for all). CONCLUSIONS: Our results show strong associations of NT/TRK expression with melanoma stage progression and a poor prognosis.

Determination of Endogenous Concentrations of Uracil and Dihydrouracil in Dried Saliva Spots by LC-MS/MS: Method Development, Validation, and Clinical Application.

BACKGROUND: The aim of this study was to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for the measurement of uracil (U) and dihydrouracil (UH2) concentrations in dried saliva spots (DSSs), for the evaluation of dihydropyrimidine dehydrogenase (DPD) enzyme activity. RESULTS: Nine 18-mm diameter DSS discs were extracted with acetate:isopropyl alcohol (85:15, vol/vol) and analyzed by LC-MS/MS. The assay was linear in the range of 10-1000 ng·mL, with accuracy between 89% and 112% and precision between 5.7% and 13%. The metabolic ratio [UH2]/[U] was stable in DSS for up to 9 days at 45°C. Concentrations of U and UH2, as well as the metabolic ratio, were highly concordant between matrices. Using a metabolic ratio classification cutoff of 1.16 for the identification of slow DPD metabolizers, 98.7% concordance was achieved between SS and saliva. CONCLUSIONS: DSS samples could be a useful alternative for DPD activity screening, particularly in locations with limited access to highly equipped laboratories.

Epidermal Growth Factor Receptor Regulation of Ewing Sarcoma Cell Function.

OBJECTIVE: Ewing sarcoma (ES) is a type of childhood cancer probably arising from stem mesenchymal or neural crest cells. The epidermal growth factor receptor (EGFR) acts as a driver oncogene in many types of solid tumors. However, its involvement in ES remains poorly understood. METHODS: Human SK-ES-1 and RD-ES ES cells were treated with EGF, the EGFR inhibitor tyrphostin (AG1478), or phosphoinositide 3-kinase (PI3K) or extracellular-regulated kinase (ERK)/mitogen-activated kinase (MAPK) inhibitors. Cell proliferation survival, cycle, and senescence were analyzed. The protein content of possible targets of EGFR manipulation was measured by Western blot. RESULTS: Cell proliferation and survival were increased by EGF and inhibited by AG1478. The EGFR inhibitor also altered the cell cycle, inducing arrest in G1 and increasing the sub-G1 population, reduced polyploidy and increased the population of senescent cells. In addition, AG1478 reduced the levels of phosphorylated AKT (p-AKT), ERK, p-ERK, cyclin D1, and brain-derived neurotrophic factor (BDNF), while enhancing p53 levels. Cell proliferation was also impaired by inhibitors of PI3K or ERK, alone or combined with AG1478. CONCLUSIONS: Our findings reveal novel aspects of EGFR regulation of ES cells and provide early evidence for antitumor activities of EGFR inhibitors in ES.

Nanoliposomal irinotecan with fluorouracil and folinic acid in metastatic pancreatic cancer after previous gemcitabine-based therapy (NAPOLI-1): a global, randomised, open-label, phase 3 trial.

BACKGROUND: Nanoliposomal irinotecan showed activity in a phase 2 study in patients with metastatic pancreatic ductal adenocarcinoma previously treated with gemcitabine-based therapies. We assessed the effect of nanoliposomal irinotecan alone or combined with fluorouracil and folinic acid in a phase 3 trial in this population. METHODS: We did a global, phase 3, randomised, open-label trial at 76 sites in 14 countries. Eligible patients with metastatic pancreatic ductal adenocarcinoma previously treated with gemcitabine-based therapy were randomly assigned (1:1) using an interactive web response system at a central location to receive either nanoliposomal irinotecan monotherapy (120 mg/m(2) every 3 weeks, equivalent to 100 mg/m(2) of irinotecan base) or fluorouracil and folinic acid. A third arm consisting of nanoliposomal irinotecan (80 mg/m(2), equivalent to 70 mg/m(2) of irinotecan base) with fluorouracil and folinic acid every 2 weeks was added later (1:1:1), in a protocol amendment. Randomisation was stratified by baseline albumin, Karnofsky performance status, and ethnic origin. Treatment was continued until disease progression or intolerable toxic effects. The primary endpoint was overall survival, assessed in the intention-to-treat population. The primary analysis was planned after 305 events. Safety was assessed in all patients who had received study drug. This trial is registered at ClinicalTrials.gov, number NCT01494506. FINDINGS: Between Jan 11, 2012, and Sept 11, 2013, 417 patients were randomly assigned either nanoliposomal irinotecan plus fluorouracil and folinic acid (n=117), nanoliposomal irinotecan monotherapy (n=151), or fluorouracil and folinic acid (n=149). After 313 events, median overall survival in patients assigned nanoliposomal irinotecan plus fluorouracil and folinic acid was 6.1 months (95% CI 4.8-8.9) vs 4.2 months (3.3-5.3) with fluorouracil and folinic acid (hazard ratio 0.67, 95% CI 0.49-0.92; p=0.012). Median overall survival did not differ between patients assigned nanoliposomal irinotecan monotherapy and those allocated fluorouracil and folinic acid (4.9 months [4.2-5.6] vs 4.2 months [3.6-4.9]; 0.99, 0.77-1.28; p=0.94). The grade 3 or 4 adverse events that occurred most frequently in the 117 patients assigned nanoliposomal irinotecan plus fluorouracil and folinic acid were neutropenia (32 [27%]), diarrhoea (15 [13%]), vomiting (13 [11%]), and fatigue (16 [14%]). INTERPRETATION: Nanoliposomal irinotecan in combination with fluorouracil and folinic acid extends survival with a manageable safety profile in patients with metastatic pancreatic ductal adenocarcinoma who previously received gemcitabine-based therapy. This agent represents a new treatment option for this population. FUNDING: Merrimack Pharmaceuticals.

CXCR2 +1208 CT genotype may predict earlier clinical stage at diagnosis in patients with prostate cancer.

Interleukin-8 (IL-8) is an angiogenic CXC chemokine that plays an important role in both the development and progression of several human malignancies including prostate cancer (PC). A single nucleotide polymorphism (SNP) at -251 upstream of the transcriptional start site of the IL-8 gene has been shown to influence its production. The effects of IL-8 are mediated by two highly related chemokine receptors, CXCR1 and CXCR2. The present study investigated the influence of the IL-8 and CXCR2 gene variation on susceptibility and clinicopathological characteristics of PC in a group of Brazilian subjects. METHODS: Two hundred and one patients and 185 healthy controls were enrolled in a case-control study. Blood was collected for DNA extraction; typing of IL-8 -251 T/A and CXCR2 +1208 C/T genes was performed by polymerase chain reaction with sequence-specific primers (PCR-SSP), followed by agarose gel electrophoresis. Risk association between the genotypes, PC susceptibility and tumor characteristics was estimated by odds ratio (OR) and 95% confidence intervals (95% CI) using logistic regression analysis, after adjusting for age at diagnosis. RESULTS: A significant association was found between the heterozygous CXCR2 +1208 CT genotype and stage of PC. The CXCR2 +1208 CT genotype was significantly less frequent in patients with clinical stage T3-T4 compared to T1-T2 (56.7 versus 80.5%). Our findings suggest that carriers of the CXCR2 +1208 CT genotype had a protective effect for advanced PC (CT versus CC: adjusted OR=0.25; P=0.02). No association was observed between the SNP for IL-8 -251 T/A and clinicopathological parameters of PC. CONCLUSION: These results indicated that the CXCR2 +1208 CT genotype is less frequent in advanced stages of PC, suggesting that this chemokine receptor plays a role in the pathogenesis of this disease.

The anticancer estrogen receptor antagonist tamoxifen impairs consolidation of inhibitory avoidance memory through estrogen receptor alpha.

Over two-thirds of women with breast cancer have positive tumors for hormone receptors, and these patients undergo treatment with endocrine therapy, tamoxifen being the most widely used agent. Despite being very effective in breast cancer treatment, tamoxifen is associated with side effects that include cognitive impairments. However, the specific aspects and mechanisms underlying these impairments remain to be characterized. Here, we have investigated the effects of tamoxifen and interaction with estrogen receptors on formation of memory for inhibitory avoidance conditioning in female rats. In the first experiment, Wistar female rats received a single oral dose of tamoxifen (1, 3, or 10 mg/kg) or saline by gavage immediately after training and were tested for memory consolidation 24 h after training. In the second experiment, rats received a single dose of 1 mg/kg tamoxifen or saline by gavage 3 h after training and were tested 24 h after training for memory consolidation. In the third experiment, rats received a subcutaneous injection with estrogen receptor α agonist or estrogen receptor beta agonist 30 min before the training. After training, rats received a single oral dose of tamoxifen 1 mg/kg or saline and were tested 24 h after training. In the fourth experiment, rats were trained and tested 24 h later. Immediately after test, rats received a single dose of tamoxifen (1 mg/kg) or saline by gavage and were given four additional daily test trials followed by a re-instatement. Tamoxifen at 1 mg/kg impaired memory consolidation when given immediately after training and the estrogen receptor alpha agonist improved the tamoxifen-related memory impairment. Moreover, tamoxifen impairs memory consolidation of the test. These findings indicate that estrogen receptors regulate the early phase of memory consolidation and the effects of tamoxifen on memory consolidation.

Viability of D283 medulloblastoma cells treated with a histone deacetylase inhibitor combined with bombesin receptor antagonists.

PURPOSE: Medulloblastoma (MB) comprises four distinct molecular subgroups, and survival remains particularly poor in patients with Group 3 tumors. Mutations and copy number variations result in altered epigenetic regulation of gene expression in Group 3 MB. Histone deacetylase inhibitors (HDACi) reduce proliferation, promote cell death and neuronal differentiation, and increase sensitivity to radiation and chemotherapy in experimental MB. Bombesin receptor antagonists potentiate the antiproliferative effects of HDACi in lung cancer cells and show promise as experimental therapies for several human cancers. Here, we examined the viability of D283 cells, which belong to Group 3 MB, treated with an HDACi alone or combined with bombesin receptor antagonists. METHODS: D283 MB cells were treated with different doses of the HDACi sodium butyrate (NaB), the neuromedin B receptor (NMBR) antagonist BIM-23127, the gastrin releasing peptide receptor (GRPR) antagonist RC-3095, or combinations of NaB with each receptor antagonist. Cell viability was examined by cell counting. RESULTS: NaB alone or combined with receptor antagonists reduced cell viability at all doses tested. BIM-23127 alone did not affect cell viability, whereas RC-3095 at an intermediate dose significantly increased cell number. CONCLUSION: Although HDACi are promising agents to inhibit MB growth, the present results provide preliminary evidence that combining HDACi with bombesin receptor antagonists is not an effective strategy to improve the effects of HDACi against MB cells.

[Recommendations for the management of pancreatic cancer type adenocarcinoma: A consensus statement reached during the 2015 Latin American Symposium on Gastroenterological Oncology]. / Recomendaciones sobre el manejo del cáncer de páncreas tipo adenocarcinoma en Latinoamérica: Reunión del Consenso del Simposio Latinoamericano de Gastroenterología Oncológica (SLAGO) y de la Asociación Ibero Latinoamericana de Terapia Radiante (ALATRO), Viña del Mar, Chile 2015.

Pancreatic cancer is a malignancy of great impact in developed countries and is having an increasing impact in Latin America. Incidence and mortality rates are similar for this cancer. This is an important reason to offer to the patients the best treatments available. During the Latin American Symposium of Gastroenterology Oncology (SLAGO) held in Viña del Mar, Chile, in April 2015, a multidisciplinary group of specialists in the field met to discuss about this disease. The main conclusions of this meeting, where practitioners from most of Latin American countries participated, are listed in this consensus that seek to serve as a guide for better decision making for patients with pancreatic cancer in Latin America.

Influence of CYP2D6 and CYP3A4 Phenotypes, Drug Interactions, and Vitamin D Status on Tamoxifen Biotransformation.

OBJECTIVE: In view of the large variability on therapeutic response and the multiple factors associated to tamoxifen (TAM) metabolic activation, this study aimed to evaluate the effect of CYP2D6 and CYP3A4 phenotypes, drug interactions, and vitamin D exposure on TAM metabolism in a group of breast cancer patients. METHODS: Trough blood samples were collected from 116 patients. TAM and metabolites endoxifen (EDF), N-desmethyltamoxifen, and 4-hydroxytamoxifen (HTF) were measured in plasma by liquid chromatography-tandem mass spectrometry. CYP2D6 and CYP3A4 phenotyping were obtained according to [dextromethorphan]/[dextrorphan] and [omeprazole]/[omeprazole sulfone] metabolic ratios, measured by high-performance liquid chromatography in plasma collected 3 hours after oral administration of 33 mg of dextromethorphan and 20 mg of omeprazole. Vitamin D3 was measured in plasma by high-performance liquid chromatography-ultraviolet. Data on concomitant use of drug considered as CYP2D6 and CYP3A4 inhibitor or inducer and vitamin D supplementation were recorded. RESULTS: About 20% of patients had reduced CYP2D6 metabolic activity and 7% CYP3A4 impaired metabolism. EDF levels diminished proportionally to the reduction of CYP2D6 metabolic activity (poor metabolizer 2.79 ng·mL, intermediate metabolizer (IM) 5.36 ng·mL, and extensive metabolizer 10.65 ng·mL, P < 0.01). Median plasma levels of TAM (161.50 ng·mL) and HTF (1.32 ng·mL) in CYP2D6 IM/CYP3A4 poor metabolizer patients were higher (P < 0.05) than those from CYP2D6 IM/CYP3A4 extensive metabolizer patients (122.07 ng·mL and 0.61 ng·mL, respectively). Seasons contributed to the interpatient variability of EDF and HTF levels; summer concentrations were 24% and 42% higher compared with winter. Vitamin D3 was not associated to CYP3A4 metabolic activity, indicating that other mechanisms might be involved in the relation between TAM metabolism and vitamin D exposure. CONCLUSIONS: CYP3A4 contributes to the bioactivation of TAM through formation of HTF and becomes increasingly important in case of reduced or absent CYP2D6 activity. EDF and HTF exposure were associated to seasonal variations, with considerable higher plasma concentrations during summer.

Gastrin-releasing peptide receptor (GRPR) mediates chemotaxis in neutrophils.

Neutrophil migration to inflamed sites is crucial for both the initiation of inflammation and resolution of infection, yet these cells are involved in perpetuation of different chronic inflammatory diseases. Gastrin-releasing peptide (GRP) is a neuropeptide that acts through G protein coupled receptors (GPCRs) involved in signal transmission in both central and peripheral nervous systems. Its receptor, gastrin-releasing peptide receptor (GRPR), is expressed by various cell types, and it is overexpressed in cancer cells. RC-3095 is a selective GRPR antagonist, recently found to have antiinflammatory properties in arthritis and sepsis models. Here we demonstrate that i.p. injection of GRP attracts neutrophils in 4 h, and attraction is blocked by RC-3095. Macrophage depletion or neutralization of TNF abrogates GRP-induced neutrophil recruitment to the peritoneum. In vitro, GRP-induced neutrophil migration was dependent on PLC-ß2, PI3K, ERK, p38 and independent of Gαi protein, and neutrophil migration toward synovial fluid of arthritis patients was inhibited by treatment with RC-3095. We propose that GRPR is an alternative chemotactic receptor that may play a role in the pathogenesis of inflammatory disorders.

PRIMA-1, a mutant p53 reactivator, induces apoptosis and enhances chemotherapeutic cytotoxicity in pancreatic cancer cell lines.

TP53 mutation is a common event in many cancers, including pancreatic adenocarcinoma, where it occurs in 50-70 % of cases. In an effort to reactivate mutant p53 protein, several new drugs are being developed, including PRIMA-1 and PRIMA-1(Met)/APR-246 (p53 reactivation and induction of massive apoptosis). PRIMA-1 has been shown to induce apoptosis in tumor cells by reactivating p53 mutants, but its effect in pancreatic cancer remains unclear. Here we investigated the effects of PRIMA-1 on cell viability, cell cycle and expression of p53-regulated proteins in PANC-1 and BxPC-3 (mutant TP53), and CAPAN-2 (wild-type TP53) pancreatic cell lines. Treatment with PRIMA-1 selectively induced apoptosis and cell cycle arrest in p53 mutant cells compared to CAPAN-2 cells. The growth suppressive effect of PRIMA-1 was markedly reduced in p53 mutant cell lines transfected with p53 siRNA, supporting the role of mutant p53 in PRIMA-1 induced cell death. Moreover, treatment with the thiol group donor N-acetylcysteine completely blocked PRIMA-1-induced apoptosis and reinforced the hypothesis that thiol modifications are important for PRIMA-1 biological activity. In combination treatments, PRIMA-1 enhanced the anti-tumor activity of several chemotherapic drugs against pancreatic cancer cells and also exhibited a pronounced synergistic effect in association with the Mdm2 inhibitor Nutlin-3. Taken together, our data indicate that PRIMA-1 induces apoptosis in p53 mutant pancreatic cancer cells by promoting the re-activation of p53 and inducing proapoptotic signaling pathways, providing in vitro evidence for a potential therapeutic approach in pancreatic cancer.

Gastrin-releasing peptide receptor signaling in the integration of stress and memory.

Neuropeptides act as signaling molecules that regulate a range of aspects of brain function. Gastrin-releasing peptide (GRP) is a 27-amino acid mammalian neuropeptide, homolog of the amphibian peptide bombesin. GRP acts by binding to the GRP receptor (GRPR, also called BB2), a member of the G-protein coupled receptor (GPCR) superfamily. GRP produced by neurons in the central nervous system (CNS) plays a role in synaptic transmission by activating GRPRs located on postsynaptic membranes, influencing several aspects of brain function. Here we review the role of GRP/GRPR as a system mediating both stress responses and the formation and expression of memories for fearful events. GRPR signaling might integrate the processing of stress and fear with synaptic plasticity and memory, serving as an important component of the set of neurobiological systems underlying the enhancement of memory storage by aversive information.

Antiproliferative activity of the dimeric phloroglucinol and benzophenone derivatives of Hypericum spp. native to southern Brazil.

A large number of plants are known to possess strong antitumor properties. Previous studies have verified the antiproliferative activity of the extracts and fractions from six species of Hypericum spp. growing in southern Brazil. In the present study, the in-vitro antiproliferative effects of two dimeric phloroglucinols (japonicin A and uliginosin B, isolated from Hypericum myrianthum) and two benzophenones (cariphenone A and cariphenone B, isolated from H. carinatum) were investigated against three tumor cell lines (HT-29 - human colon carcinoma cells; U-251 - human glioma cell line, and OVCAR-3 - human ovarian carcinoma cells). In addition, different doses of these compounds were associated with cytotoxic drugs commonly used as chemotherapy in the clinic. Cariphenone A and cariphenone B showed moderate antiproliferative activity against all tumor cell lines at a dose of 100 µg/ml. Unlike benzophenones, japonicin A and uliginosin B exerted antiproliferative effects only in the OVCAR-3 cell line. Moreover, a very strong synergistic effect was demonstrated by the association of subeffective doses of japonicin A with the chemotherapeutic drug paclitaxel, decreasing cellular proliferation of the OVCAR-3 cell line. These preliminary results provide a scientific basis to further pursue these compounds as potential combined therapy for certain tumor types.

Anti-EGFR therapy combined with neuromedin B receptor blockade induces the death of DAOY medulloblastoma cells.

PURPOSE: Medulloblastoma is the most common malignant childhood brain tumor for which the development of new molecularly targeted therapies is needed. Novel therapeutic targets under investigation include growth factor receptors. Here, we show that the combined inhibition of the epidermal growth factor receptor (EGFR) and neuromedin B receptor (NMBR, BB1) results in increased cell death in human medulloblastoma cell lines. METHODS: DAOY and D283 human medulloblastoma cells were treated with human recombinant neuromedin B (NMB, an NMBR agonist), the NMBR antagonist BIM-23127, the anti-EGFR monoclonal antibody cetuximab, or BIM-23127 combined with cetuximab. Cell death was examined with trypan blue cell counting. RESULTS: Both cell lines expressed mRNA for EGFR, NMB, and NMBR detected by reverse transcriptase polymerase chain reaction. Cetuximab at 10 µg/ml significantly reduced the number of DAOY cells, but did not affect D283 cells. NMB and BIM-23127 did not change cell number when used alone. However, cetuximab, at a dose that did not have an effect by itself, was able to reduce the number of DAOY cells when combined with BIM-23127. CONCLUSION: These results provide preliminary evidence that NMBR blockade can potentiate the antitumor effect of anti-EGFR therapy in medulloblastoma.

Obesity, diabetes, and cancer: epidemiology, pathophysiology, and potential interventions.

The proportion of deaths attributable to cancer is rising, and malignant neoplasms have become the leading cause of death in high-income countries. Obesity and diabetes are now recognized as risk factors for several types of malignancies, especially endometrial, colorectal, and postmenopausal breast cancers. Mechanisms implicated include disturbances in lipid-derived hormone secretion, sex steroids biosynthesis, hyperinsulinemia, and chronic inflammation. Intentional weight loss is associated with a mitigation of risk for obesity-related cancers, a phenomenon observed specially with bariatric surgery. The impact of pharmacological interventions for obesity and diabetes is not uniform: while metformin seems to protect against cancer, other agents such as lorcaserin may increase the risk of malignancies. However, these interpretations must be carefully considered, since most data stem from bias-prone observational studies, and high-quality randomized controlled trials with appropriate sample size and duration are needed to achieve definite conclusions. In this review, we outline epidemiological and pathophysiological aspects of the relationship between obesity, diabetes, and malignancies. We also highlight pieces of evidence regarding treatment effects on cancer incidence in these populations.

Evaluation of UGT1A1 and CYP3A Genotyping and Single-Point Irinotecan and Metabolite Concentrations as Predictors of the Occurrence of Adverse Events in Cancer Treatment.

PURPOSE: The variability on irinotecan (IRI) pharmacokinetics and toxicity has been attributed mostly to genetic variations in the UGT1A1 gene, responsible for conjugation of the active metabolite SN-38. Also, CYP3A mediates the formation of inactive oxidative metabolites of IRI. The association between the occurrence of severe adverse events, pharmacokinetics parameters, and UGT1A1 and CYP3A4 predicted phenotypes was evaluated, as the evaluation of [SN-38]/IRI dose ratio as predictor of severe adverse events. METHODS: Forty-one patients undergoing IRI therapy were enrolled in the study. Blood samples were collected 15 min after the end of drug the infusion, for IRI, SN-38, SN-38G, bilirubin concentrations measurements, and UGT1A1 and CYP3A genotype estimation. Data on adverse event was reported. RESULTS: Fifteen patients (36.5%) developed grade 3/4 adverse events. A total of 9.8% (n = 4) of the patients had UGT1A1 reduced activity phenotype, and 48.7% (n = 20) had UGT1A1 and 63.4% (n = 26) CYP3A intermediary phenotypes. Severe neutropenia and diarrhea were more prevalent in patients with reduced UGT1A1 in comparison with functional metabolism (50% and 75% versus 0% and 13%, respectively). SN-38 levels and its concentrations adjusted by IRI dose were significantly correlated to toxicity (rs = 0.31 (p = 0.05) and rs = 0.425 (p < 0.01)). The [SN-38]/IRI dose ratio had a ROC curve of 0.823 (95% CI 0.69-0.956) to detect any severe adverse event and 0.833 (95% CI 0.694-0.973) to detect severe diarrhea. The cut-off of 0.075 ng mL-1 mg-1 had 100% sensitivity and 65.7% specificity to predict severe diarrhea. CONCLUSION: Our data confirmed the relevance of the pre-emptive genotypic information of UGT1A1. The [SN-38]/IRI ratio, measured 15 min after the end of the IRI infusion, was a strong predictor of severe toxicity and could be applied to minimize the burden of patients after IRI administration.