Identification of potential pharmacogenomic markers of clinical efficacy of 5-fluorouracil in colorectal cancer.

Although adjuvant chemotherapy has significantly increased overall survival in resected Stage III colorectal cancer, disease recurrence is still high (30-40%). 20-25% of Stage II patients also develop recurrent disease. Thus, high-risk patients may benefit from chemotherapy. As patient response to standard chemotherapy varies, the study of molecular differences in the expression of pharmacologically relevant genes may help clinicians to understand variability and tailor therapy. The expression of 5-fluorouracil (5-FU) pathway genes in tumors from 53 Stages II-III colorectal cancer patients who underwent 5-FU adjuvant chemotherapy was investigated by reverse transcription quantitative real-time polymerase chain reaction. Patients were dichotomized into high- and low-mRNA expression level groups using median values of gene mRNA levels. Then, a threshold analysis to identify a cut-off distinguishing recurrent- or nonrecurrent-disease was used. A high degree of interpatient variation in relative tumor expression of study genes was observed. Multiple gene correlations were found, which suggest possible coregulation mechanisms. No statistically significant relationship between experimental data and baseline clinical/pathological characteristics or clinical outcome was observed using gene expression median values. Threshold analysis indicated significant inverse relationships between deoxyuridine triphosphatase (DUT), ferrodoxin reductase (FDXR) or tumor protein p53 (TP53) and disease-free survival (DFS) in the entire case series and between DUT or NM23-H1 and DFS in Stage III patients: higher gene expression was associated with shorter DFS. This study provides data on relationships between expression of 5-FU pathway genes and clinical outcome of colorectal cancer patients undergoing 5-FU adjuvant chemotherapy and underscores the predictive role of specific genes. Validation in an independent case series is warranted.

Thymidylate synthase expression and genotype have no major impact on the clinical outcome of colorectal cancer patients treated with 5-fluorouracil.

BACKGROUND AND OBJECTIVES: Thymidylate synthase (TS) expression levels appear to be related to response to 5-fluorouracil-(5-FU)-based chemotherapy in colorectal cancer (CRC) patients. Three polymorphisms have been proposed as modulators of TS expression: a tandemly repeated sequence (2R/3R) in the 5' UTR, a SNP (G>C) within the 3R allele and a 6bp deletion in the 3' UTR. To evaluate the influence of TS expression and polymorphisms on clinical outcome of 5-FU-treated patients we performed a comprehensive genetic analysis on 63 CRC patients. METHODS: TS expression levels were analyzed in normal and tumor tissues. TS coding sequence and UTR polymorphisms were investigated on DNA from normal tissue. LOH analysis was performed to determine tumor genotype. RESULTS: A difference in disease-free survival (DFS), although not statistically significant, was observed between high and low mRNA expression levels: patients with low levels showed longer DFS. The 2R2R genotype showed significantly lower expression than the 3R3R and 2R3R genotypes in normal tissue. No other TS polymorphism was associated with mRNA expression or clinical outcome. CONCLUSIONS: The results obtained in this pilot study indicate that the number of 5' UTR repeats is the major genetic determinant of TS expression. The lack of association with other polymorphisms might be partially explained by the existence of linkage disequilibrium in the TS gene. Our data support the growing evidence that TS control may require multiple mechanisms acting in close coordination with one another and suggest that TS genotyping alone in tumor samples is not sufficient to accurately predict response to 5-FU.

Life-long individual planning in children with developmental disability: the active role of parents in the Italian experience.

Many young adults with neurodevelopmental disorders experience poor transition outcomes in key areas, including employment, health care, and independent living. Innovative welfare models highlight the importance of involving the local community, and in particular the parents, as important stakeholders capable to generate services and affect local economy. As indicated by the World Health Organization, the availability of person-centered responses, also providing a health budget, appears to be the basis for taking into account person's rights to self-determination. Health services and local stakeholders could play an important role to facilitate the implementation of support networks that are functional for an effective social inclusion. In order to improve current practices in transitioning to adulthood, it is of paramount importance to collect and learn from the living experience of people with neurodevelopmental disabilities and their families.

Analysis of gene expression profiles reveals novel correlations with the clinical course of colorectal cancer.

In order to discover potential markers of prognosis in colorectal cancer (CRC) we have determined gene expression profiles, using cDNA microarrays in CRC samples obtained from 19 patients in Dukes stages C and D, with favorable clinical course (Dukes C patients, survival >5 years after surgery, group A, n=7) or unfavorable clinical course (Dukes stage C and D patients, survival <5 years after surgery, group B, n=12). Gene expression was measured in RNA from each tumor, using a pool of equal amounts of RNA from all tumors as a reference. To identify and rank differentially expressed genes we used three different analytical methods: (i) Significance Analysis of Microarrays (SAM), (ii) Cox's Proportional Hazard Model, and (iii) Trend Filter (a mathematical method for the assessment of numerical trends). The level of expression of a gene in an individual tumor was regarded as of interest when that gene was identified as differentially expressed by at least two of these three methods. By these stringent criteria we identified eight genes (ITGB2, MRPS11, NPR1, TXNL2, PHF10, PRSS8, KCNK3, JAK3) that were correlated with prolonged survival after surgery. Pathway analysis showed that patients with favorable prognosis had several activated metabolic pathways (carbon metabolism, transcription, amino acid and nitrogen metabolism, signaling and fibroblast growth factor receptor pathways). To further validate individual gene expression findings, the RNA level of each gene identified as a marker with microarrays was measured by real-time RT-PCR in CRC samples from an independent group of 55 patients. In this set of patients the Cox Proportional Hazard Model analysis demonstrated a significant association between increased patient survival and low expression of ITGB2 (p = 0.011) and NPR1 (p = 0.023) genes.

Relationships between promoter polymorphisms in the thymidylate synthase gene and mRNA levels in colorectal cancers.

Thymidylate synthase (TS) intratumoural expression may be a prognostic marker and predict outcome of 5-fluorouracil (5-FU)-based chemotherapy in colorectal cancer patients. The TS gene promoter enhancer region contains two different polymorphisms which can influence TS mRNA transcriptional and translational efficiency: a polymorphic tandem repeat sequence (2 or 3 repeats; 2R and 3R) and a single nucleotide polymorphism (SNP), G > C, within the second repeat of the 3R alleles. We studied the relationship between tumoural TS mRNA expression levels and TS gene polymorphisms in the colonic mucosa of 48 colorectal cancer patients. The 3R/3R genotype was characterised by higher TS mRNA levels in the tumour than the 2R/2R-2R/3R genotypes (P = 0.071). Regarding the relationship with the SNP polymorphism, a statistically significant difference in TS gene expression between the 3RG/3RG genotype and 2R/2R-2R/3RC-2R/3RG genotype subset was observed (P = 0.017). No statistically significant correlation was observed between experimental data and baseline clinical-pathological characteristics as well as clinical outcome in the relatively small patient series investigated. This is the first study reporting an association between the TS intra-repeat SNP and gene expression levels in colorectal cancer patients. These results suggest that in 3R/3R patients, the G > C polymorphism may be an important factor in determining TS mRNA expression levels, and warrant further investigation of the role of TS promoter polymorphisms as predictors of sensitivity to 5-FU-based chemotherapy in larger case series.

Molecular characterization of established human colon carcinoma cell lines (HCT-8) made resistant to 5-fluorouracil by different selection schedules.

To provide some insight into molecular mechanisms of 5 fluorouracil (5-FU) clinical resistance in colorectal cancer, we hypothesized that different in vitro exposure schedules of human colorectal cancer cell lines mimicking clinical infusion or bolus regimens could lead to differential gene expression. Resistant HCT-8 colon cancer cell lines (HCT-8/FUI/15R and HCT-8/FUB/2R) were selected from parental sensitive HCT-8 cells by long-term and short-term exposure schedules, respectively. Expression levels of the 437 genes evaluated by the Atlas Select cDNA Expression Human Tumor Array were not substantially different between HCT-8/FUB/2R and HCT-8 cell lines except for three genes downregulated in the resistant subline. Several genes were differentially expressed in HCT-8/FUI/15R cells compared to the parental cell line: 43 genes, including three chemoresistance-related genes, were upregulated, and three genes were downregulated. HCT-8/FUB/2R cells were substantially more resistant to 5-FU in comparison to HCT-8/FUI/15R cells after both 4- and 72-h exposures. No substantial differences were observed among resistant and parental cells in sensitivity to SN-38, the active metabolite of irinotecan, and oxaliplatin. Analysis of the mRNA levels of thymidylate synthase, thymidine phosphorylase, and bcl-2 genes evaluated by reverse transcription and real time PCR (RT-PCR) assay showed comparable results in resistant sublines and sensitive parental cells, whereas expression of the dihydropyrimidine dehydrogenase gene was markedly increased in both resistant cell lines compared to parental cells.

Evaluación infectológica inicial y seguimiento prospectivo de una cohorte de pacientes sometidos a inmunosupresión inducida / Initial assessment and prospective follow-up of a cohort of patients with immunosuppressive therapy by an infectious diseases physician

El uso de inmunosupresores generó una población creciente de pacientes con defectos en el sistema inmune. Creamos un consultorio especializado en la atención infectológica de dichos pacientes. Objetivos: Describir los antecedentes clínicos y la prevalencia de infecciones latentes, evaluar el estado de vacunación, determinar la necesidad de profilaxis antimicrobiana. Describir la frecuencia de aparición infecciones oportunistas (IO). Materiales y métodos: estudio descriptivo, prospectivo de pacientes atendidos en un consultorio que estuvieran bajo tratamiento inmunosupresor (noviembre 2015-enero 2017). Se recolectaron datos demográficos, clínicos y factores de riesgo para IO. Se realizó pesquisa de tuberculosis (TB), serologías para HIV, hepatitis A, B y C, sífilis, toxoplasmosis, Chagas, búsqueda de Strongyloides spp. Se indicaron vacunas de acuerdo con las recomendaciones actuales. Se realizó seguimiento para detección de IO. Resultados: n=197, media de edad 50,7 años (DE 14), mujeres 79,7%. Enfermedades de base: artritis reumatoidea 52%, lupus 12%. Drogas inmunosupresoras: metotrexato 45%, corticoides 16%, biológicos anti-TNF 15%, micofenolato 10%, ciclofosfamida 4%. Se diagnosticaron 49 (25%) infecciones: 15 Chagas, 15 anti-HBc positivo aislado, 7 sífilis, 4 HIV, 4 TB latentes, 2 HBV, 1 HCV, 1 estrongiloidiosis. Se indicó profilaxis antimicrobiana en 27 (14%) pacientes. En todos se intervino indicando o completando los esquemas de vacunación. Se detectaron 7 IO. Conclusiones: En el 39% de los pacientes, la evaluación sistematizada arrojó hallazgos que motivaron intervenciones, ya sea terapéuticas o de monitoreo. En el 100% fue necesaria la prescripción de vacunas. Esto pone en evidencia la importancia de evaluar sistemáticamente en consultorios especializados a estos pacientes

Introduction: The extensive use of immunosuppressive drugs resulted in a growing population of patients with defects in the immune system. We opened an infectious diseases practice focused on the attention of these patients. Our objectives were to describe the clinical history and prevalence of latent infections, evaluate the vaccination status, determine the need for antimicrobial prophylaxis and describe the frequency of opportunistic infections (OI). Methods: We performed a descriptive and prospective study of patients seen at a medical practice who were under immunosuppressive therapy (November 2015-January 2017). Demographic and clinical history, as well as risk factors for OI were collected. Tuberculosis (TB) screening, serologies for HIV, hepatitis A, B and C, syphilis, toxoplasmosis, Chagas and Strongyloides spp. screening were performed. Vaccines were indicated according to current recommendations. Follow-up was performed for IO detection. Results: n=197. Mean age: 50.7 years (SD 14). Female 79.7%. Underlying diseases: rheumatoid arthritis 52%, 12% lupus. Immunosuppressive drugs: methotrexate 45%, corticoids 16%, biological anti-TNF agents 15%, mycophenolate 10%, cyclophosphamide 4%. Forty-nine (25%) infections were diagnosed: 15 Chagas, 15 anti-HBc positive isolated, 7 syphilis, 4 HIV, 4 latent TB, 2 HBV, 1 HCV, 1 strongyloidiosis. Antimicrobial prophylaxis was indicated in 27 (14%) patients. In all cases, vaccination schemes were indicated or completed. Seven IO were detected. Conclusions: In 39% of the patients, the systematized evaluation revealed findings that motivated interventions, either therapeutic or monitoring. In 100% the prescription of vaccines was necessary. These findings highlight the importance of a systematically evaluation of these patients in specialized care centers.

Apoptosis shifts to necrosis via intermediate types of cell death by a mechanism depending on c-myc and bcl-2 expression.

Hypoxic and chemical hypoxia (antimycin A) commits cultured rat fibroblasts (Rat-1) towards apoptosis, necrosis or an intermediate form of cell death (aponecrosis) depending on the degree of hypoxia. Aponecrosis also occurs in vivo. Here, we demonstrate that c-myc and bcl-2, two proto-oncogenes known to lower or to enhance, respectively, the apoptotic threshold, also affect the type of cell death: apoptosis shifts to aponecrosis and aponecrosis to necrosis, depending on c-myc or bcl-2 expression and the antimycin A concentration (100-400 microM). In cells with basal gene expression, apoptosis shifts to aponecrosis/necrosis at 300 microM antimycin A (middle hypoxia). Overexpression of c-myc markedly increases cumulative cell death in response to antimycin A and lowers the antimycin A concentration required to shift apoptosis to aponecrosis/necrosis from 300 microM to 100 microM (low hypoxia). Overexpression of bcl-2 elicits the opposite effect, decreasing cumulative cell death in response to antimycin A and raising the drug concentration required to shift apoptosis to aponecrosis/necrosis to 400 microM (high hypoxia). The passage from one to the other form of cell death involves various aponecrotic features with observed intermediate aspects between apoptosis and necrosis, a progressive increase in necrotic features being correlated with an increase in antimycin A concentration. The mechanism underlying the various effects of c-myc and bcl-2 on cell-death type has been related to the ability of these genes to counteract, to various extents, the ATP decrease occurring in response to different degrees of chemical hypoxia.