Expression analysis of genes involved in oxaliplatin response and development of oxaliplatin-resistant HT29 colon cancer cells

The interrelationship between platinum resistance and clinical response is not well established. The purpose of this study is to evaluate the expression of 14 genes involved in platinum resistance in a colon cancer cell line (HT29) and its oxaliplatin (OXA)-resistant sublines. Resistant cells exhibited lower expression of many of these genes suggesting that several pathways may be implicated in OXA resistance. Particularly, OXA resistance is accompanied by defects in drug uptake (downregulation of the hCTR1 transporter) and enhanced DNA repair (upregulation of the XPD gene). Our data also confirmed that copper transporters and chaperones are involved in OXA resistance in colorectal cancer cells as evidenced by the overexpression of ATP7A and CCS in response to OXA exposure. Moreover, increased CCS expression suggests a role for SOD1 in OXA detoxification. Whereas exposure to OXA in HT29 induced significant changes in expression of many of the genes analyzed, only ATP7A, XPD and SRPK1 gene expression was increased in OXA-treated HTOXAR3 resistant cells. To our knowledge, this is the first report of implicating SRPK1 in OXA resistance. This study provides the basis for further evaluation of these putative markers of OXA response and resistance in colorectal cancer patients who are candidates for treatment with OXA.

Phase II comparative study of capecitabine combined with oxaliplatin (XELOX) and CPT-11 (XELIRI) for advanced colorectal cancer patients (p) previously treated with 5-FU-based chemotherapy

14544

Background: Based on the results obtained with Capecitabine (XEL), Oxaliplatin (OX), and CPT-11 (IRI), we proposed this exploratory study to asses the efficacy of XELIRI and XELOX, for advanced colorectal cancer, after a first line treatment with 5 FU plus OX (FOLFOX) or IRI (FOLFIRI). Methods: P aged = 18 with histological diagnosis of metastatic colorectal adenocarcinoma, were assigned to XELOX arm (XEL, 1000 mg/m2 BID during 14 d; OX, 130 mg/m2 d1; q3w) or XELIRI arm (XEL 1000 mg/m2 BID during 14 d; IRI 240 mg/m2 d1; q3w), depending on previous treatment (FOLFIRI or FOLFOX, respectively). Although sample size was calculated for 115 p, recruitment was premature closed due to the low inclusion rate related with cetuximab + IRI approval for second line treatment. Results: Forty three p (25 p, XELOX; 18 p, XELIRI) were enrolled: median age 63.2 years; M/F, 40.5%/59.5%; ECOG PS 0–1, 79.1%. All p have been previously treated for metastatic disease and 65.1% had stage IV. Main sites of metastatic disease were liver (71.8%), lymph nodes (7.7%), pelvis (7.7 %) and lung (5.1%). XELOX/XELIRI treatment data: total number of administered cycles was 94/85 and median relative dose intensity 100%(XEL)/99%(OX) and 96%(XEL)/94%(IRI); disease control rate (PR+SD) was 28%/33.3%, median TTP 3.4/4.1 months, median OS 10.3/11.2 months and 1-year survival, 39.1%/44.3%, respectively. Twenty p (46.5%) received further antitumoral treatment. Most frequent G3–4 toxicities per p are detailed in table 1 . Conclusions: Capecitabine based combinations show an excellent toxicity profile and good efficacy results, in terms of disease control and survival rates, for advanced colorectal cancer patients previously treated with 5-FU schedules.

[Table: see text]

No significant financial relationships to disclose.

Weekly docetaxel with concomitant radiotherapy in patients with inoperable oesophageal cancer

INTRODUCTION

To evaluate the efficacy and tolerability of weekly docetaxel concurrent with radiotherapy in inoperable oesophageal cancer patients.

MATERIAL AND METHODS

Thirty-four oesophageal cancer patients with co-morbid medical conditions, locally advanced tumours (T4) or advanced age (older than 75 years) received docetaxel (20 mg/m2 weekly) plus concurrent radiotherapy (2 Gy daily, to a total dose of 66 Gy). Twenty-two patients (64%) were stage III, 19 of whom had T4 tumours.

RESULTS

Twenty-seven patients (79%) completed the planned chemoradiotherapy treatment. Nine patients (26%) achieved a complete response and 8 (24%) achieved a partial response, for an overall response rate of 50%. Median survival was 6 months, and 1-year survival was 35%. Patients with T4 tumours had significantly shorter survival than other patients: 5 months for T4 tumours vs. 11 months for T1-3 (p=0.04). Grade 3-4 oesophagitis occurred in 6 patients (17%). There were two treatment-related deaths due to radiation pneumonitis.

CONCLUSIONS

Docetaxel plus concurrent radiotherapy is active in poor-prognosis oesophageal cancer patients, with a lower incidence of severe oesophagitis than with cisplatin-based chemoradiotherapy regimens. This schedule can be considered, especially in patients with non-T4 tumours who are not candidates for oesophageal resection.

Composición corporal de cabras criollas neuquinas en distintas notas de condición corporal

Se evaluó la relación existente entre las notas de condición corporal (CC) y la composición corporal en 20 cabras adultas de la raza Criolla Neuquina. Previo al sacrificio se registró el peso y la condición corporal lumbar (CCL), condición corporal esternal (CCE) y condición corporal caudal (CCC). Luego del sacrificio y el desuello, se separaron la grasa omental y mesentérica, procediendo luego a separar la grasa pericárdica. Finalmente se pesaron por separado todos los componentes grasos extraídos. La canal se pesó fresca y a las 24 h, luego del oreo. Se separó la grasa de pélvico-renal (KKCF), luego se dividió la canal en dos mitades iguales con sierra eléctrica y se pesó la canal izquierda. Para finalizar se llevó a cabo la disección de la media canal izquierda en sus componentes grasa subcutánea, grasa intermuscular, hueso y magro. Los valores del presente trabajo confirman la deposición prematura de la grasa intermuscular y mesentérica y tardía de la KKCF, subcutánea y omental. La mayor correlación correspondió a la KKCF, confirmando la conveniencia de utilizar este parámetro en la estimación del grado de engrasamiento. La mejor correlación entre las distintas notas de CC y los depósitos grasos expresados como proporción del peso vivo prefaena se obtuvo entre CCL y grasa total.

Optimizing and modelling nitrogen removal in a new configuration of the moving-bed biofilm reactor process

A new configuration of the moving-bed biofilm reactor process with pre-denitrification and nitrification was investigated in a pilot plant, which is fed with urban raw wastewater, the primary settler is located between the anoxic and the aerobic reactors, and primary sludge is recycled to the anoxic reactor as a hybrid pre-denitrification. The carriers used in the experiments are made of high-density polyethylene, with a diameter of 10 mm and a specific surface area of 400 m(2)/m(3). The new process was compared with conventional pre-denitrification-nitrification using in-series reactors fed with settled wastewater. The new configuration achieved an increase of 45% for the denitrification rate and of 30% for the nitrification rate when compared with conventional configuration. These results were analysed in light of the calibration study of the mixed-culture biofilm (MCB) model and simulations in AQUASIM 2.1 platform. Regarding denitrification, the high values obtained in the new configuration were attributed to a higher removal of the slowly biodegradable substrate (Xs) in the anoxic reactor due to the use of raw wastewater and sludge recycle. Accordingly, the amounts of heterotrophic biomass (XH) and Xs obtained in simulations were higher in both the biofilm and the bulk liquid. Regarding nitrification, the higher values were attributed to a lower removal of Xs in the aerobic reactors and accordingly, a lower accumulation of heterotrophic biomass in the biofilm was found in the simulations.

Recent developments in clinimetric instruments

Assessment of impairment and function is essential in order to monitor joint status and evaluate therapeutic interventions in patients with haemophilia. The improvements in the treatment of haemophilia have required the development of more sensitive tools to detect the more minor dysfunctions that may now be apparent. This paper outlines some of the recent developments in this field. The Haemophilia Joint Health Score (HJHS) provides a systematic and robust measure of joint impairment. The MRI Scoring System has been designed to provide a comprehensive scoring system combining both progressive and additive scales. The Functional Independence Score for Haemophilia (FISH) has been developed to assess performance of functional activities and can be used in conjunction with the Haemophilia Activities List (HAL) which provides a self report measure of function. It is recommended that both measures are evaluated as these tools measure different constructs. Further refinement and testing of the psychometric properties of all of these tools is in progress. More widespread use of these tools will enable the sharing of data across the world so promoting best practice and ultimately enhancing patient care.

Gene expression profile related to oxaliplatin resistance in a panel of sensitive human colorectal cancer cell lines with acquired resistance to the drug

13143

Background: Platinum drugs resistance acquisition is a complex process based in the alteration of genes that belong to several pathways related to drug metabolism. To clarify the multifactoriality of these mechanisms, we analyzed gene expression profile in the four CCR cell lines HT29, LoVo, DLD1 and LS513, and their sublines HTOXAR, LOVOXAR, DLDOXAR y LSOXAR that we induced oxaliplatin resistance in our laboratory. The aim of this work consisted on comparing gene expression profile between resistant cells group (cluster R) and sensitive cells group (cluster S) to determine genes and pathways that could play a role in oxaliplatin resistance acquisition process. Methods: Resistance level determination by MTT assay. Gene expression profile analysis through microarray technology (Human 19K oligo): labeled with Genisphere 3DNA Array350 (Dye Swap), and data analysis using Imagene 4.1, ArrayNorm1.7.2 y Genesis 1.5.0 (ANOVA). Results: According to ANOVA analysis of cluster R versus cluster S, we obtained 32 genes that showed significant changes in expression. 15 of these genes were up regulated and 17 were down regulated. We emphasize genes that belong to pathways previously related to oxaliplatin metabolism (AKT1, TRIP and NLK), family of genes that does not expressed in the same chromosome (KIAA0232 and KIAA0256, SLC39A9 and SLC30A9), and family of genes that had previously related to carcinogenesis processes (KRT19, KRT18 and KRT8). Conclusions: It is possible to develop oxaliplatin resistant CCR cell lines. In our oxaliplatin acquired resistance model, 32 genes showed gene expression changes between groups. These genes belong to signal transduction pathways and cellular integrity mechanisms and they could be a future oxaliplatin resistance prediction profile in colorectal cancer patients.

No significant financial relationships to disclose.

Randomized phase III trial of the TTD Group comparing capecitabine and oxaliplatin (XELOX) vs. oxaliplatin and 5-fluorouracil in continuous infusion (FUFOX) as first line treatment in advanced or metastatic colorectal cancer (CRC)

3580

Background: OX plus CI 5-FU is one of the standard chemotherapy regimens for first-line treatment in patients (p) with advanced CRC. Phase II trials have shown XELOX as a convenient combination, with a high activity and a favourable safety profile. This study is a phase III trial comparing both schedules. Methods: Multicenter, randomized and open labeled study was designed to include p withadvanced/metastatic CRC adenocarcinoma, measurable disease, PS ≥70% and adequate bone marrow, renal and hepatic functions. Previous adjuvant chemotherapy was allowed. Primary endpoint is time to progression (TTP). The study was designed to determined non-inferiority when the median time to progression in the XELOX arm was not lower than 5.5 months (hazard ratio no larger than 1.27). A sample size of 348 p (174 per arm) was necessary (0.05 level test; 80% power). Treatment: P were randomly assigned to receive either Arm A: oral XEL 1000 mg/m2 twice daily from day 1 to day 15, plus OX 130 mg/m2, iv, 2h, day 1 (in 3-week treatment cycles) or Arm B: biweekly 85 mg/m2, OX, iv, 2h, plus weekly CI 5-FU 2250 mg/m2, in 48h (TTD schedule). Treatment was continued, until progressive disease, unacceptable toxicity or consent withdrawal. Results: 340 (170/170) p have been included in the interim analysis over 348 enrolled, (M/F, 61%/39%), median age: 65.6 years (32.3–81.6), PS 90–100%: 62%. Primary tumour sites were colon (66.4%), rectum (28.3%) and both (5.3%). Median relative dose intensity was 90% for XEL and 92% for OX in arm A and 78% for OX and 78% for 5-FU in arm B. Efficacy: overall response rate in each arm (A/B) was 37.1/43.0% (p=0.824). With a median follow up of 12.6 months, median TTP was 8.8/9.6 months (p=0.130). Main grade 3–4 toxicity per p in each arm (A/B) was: paresthesia (17.7/15.9%), asthenia (12.4/17.1%), diarrhea (14.1/23.6%), neutropenia (8.3/10.0%) and vomiting (4.1/7.6%). Mature data on TTP and OS will be presented at the meeting. Conclusions: Efficacy and safety results suggest a similar toxicity profile, response rate and TTP for both regimens.

No significant financial relationships to disclose.

Clinical and immunological characteristics of type 1 diabetes mellitus in a northwestern Colombian population

We underwent a project aimed to define the clinical and immunological characteristics of type 1 diabetes (T1D) in a Colombian population. This was a multicenter and cross-sectional study. Patients were systematically interviewed and their medical records reviewed, using a questionnaire that sought information about demographic, clinical and immunological characteristics. Glutamic acid decarboxylase antibodies (GADA), tyrosine phosphatase antibodies (IA-2A) and insulin antibodies (IAA) were examined by radioimmunoassay. There were 107 patients with T1D. Male:female ratio was 1:1. Half of the patients developed diabetes ketoacidosis at onset. GADA, IA-2A, and IAA were detected in 45%, 40%, and 69% of the cases, respectively. GADA positive patients were older and had a less duration of disease than patients without these autoantibodies (p<0.01). Association between breast feeding with the presence of antibodies or clinical characteristics was not observed. The results highlight some differences of T1D expression according to geographic location and ethnicity. Differences in age at onset and clinical variables may point to an environmental factor or deficient access to health care system. Genetic studies underway will provide important information in this population. These results might help to define public health policies in our population to improve T1D diagnosis, patients' quality of life and their outcome.

Determination of carbaryl in natural water samples by a surface plasmon resonance flow-through immunosensor

The analysis of carbaryl in natural water samples was accomplished using a portable immunosensor based on surface plasmon resonance (SPR) technology. The assay was based on a binding inhibition immunoassay format with the analyte derivative covalently immobilized on the sensor surface. An alkanethiol self-assembled monolayer (SAM) was formed onto the gold-coated sensor surface to allow the reusability of the same sensing surface during 220 regeneration cycles. Reproducibility was evaluated by performing three independent assays in triplicate on 3 different days. The batch-assay variability was also calculated using three different gold-coated sensor surfaces. The intra- and inter-day relative standard deviation were 8.6 and 15.3%, respectively, whilst a variation of 7.4% in assay sensitivity was obtained by employing different sensor chips. The lowest detection limit, calculated as the concentration providing a 10% decrease of the blank signal, was of 1.38 microg L(-1). Matrix effects were also evaluated in different water types, showing I50 values (carbaryl concentrations that produced a 50% decrease of the blank signal) within the range of carbaryl standard curves in distilled water (2.78-3.55 microg L(-1)). The carbaryl immunoassay performance was validated with respect to conventional high-performance liquid chromatography-mass spectrometry (HPLC-MS). The correlation between methods was in good agreement (r2 = 0.998, 0.999 and 0.999) for the three types of natural water samples tested. A complete assay cycle, including regeneration, is accomplished in 20 min. All measurements were carried out with the SPR sensor system (beta-SPR) commercialised by the company SENSIA, SL (Spain). The small size and low-time of response of the beta-SPR platform would allow its utilization in real contaminated locations.

Guides for adjuvant treatment of colon cancer

The choice of the most suitable chemotherapy schedule for the adjuvant treatment of colon cancer has been reviewed by the TTD group, as well as the principles of risk assessment for patients with stage II disease. In the light of data now available, oxaliplatin- based schedules (FOLFOX4 or FLOX) are recommended. Alternatives in special situations are monotherapy with capecitabine, UFT/LV, or 5- FU/LV in infusion. In patients with stage II disease, the indication of chemotherapy must be individualized and based on the patient's risk of recurrence (perforation, obstruction, peritumoral lymphovascular involvement, poorly differentiated histology, number of lymph nodes examined < or = 11, pre-surgical CEA), and comorbidities that can compromise the safety of treatment or survival of the patient.

Synthesis and cytotoxicity of hydrophobic esters of podophyllotoxins

Diverse norbornenecarboxylate esters of podophyllotoxin and its epimers and diastereoisomers have been prepared through Diels-Alder cycloaddition by treating the dienophilic acrylates of cyclolignans with cyclopentadiene. Their cytotoxicities against several cancer cell lines have been evaluated and the results compared with those found for other lignan esters. Podophyllotoxin adducts showed a one-fold increase in activity when compared to the natural product. The preparation of more hydrophobic esters, which showed less cytotoxicity, demonstrated that this activity is not primarily due to the lipophilic factor, but mainly to the spatial arrangement of the bulky moiety, which could contribute to increase the binding to the target site.

Phase I/II trial of irinotecan plus high-dose 5-fluorouracil (TTD regimen) as first-line chemotherapy in advanced colorectal cancer

BACKGROUND

We conducted a phase I/II study of weekly irinotecan [30 min intravenous (i.v.) infusion] combined with 5-fluorouracil (5-FU 3 g/m(2) weekly 48 h i.v. infusion, TTD regimen) as first-line chemotherapy for patients with advanced colorectal cancer (CRC).

PATIENTS AND METHODS

The maximum tolerated dose (MTD) and the dose-limiting toxicity (DLT) in the treatment of gastrointestinal solid tumors (in phase I), and the antitumor activity and toxicity of the recommended phase I dose (in phase II) were determined.

RESULTS

Diarrhea was the DLT, and irinotecan 80 mg/m(2) plus 5-FU 3 g/m(2) was the recommended phase I dose. In phase II, the confirmed response rate was 44% [95% confidence interval (CI) 29% to 59%] and the median overall survival was 23.8 months. However, grade 3/4 diarrhea affected 59% of patients and led to withdrawal of three patients. A second cohort of patients studied using the same schedule but with a reduced 5-FU starting dose of 2.25 g/m(2) showed improved tolerance (the incidence of grade 4 diarrhea decreased from 28% to 11% and overall grade 3/4 diarrhea to 56%, with no patient withdrawals) but the confirmed response rate was 28% (95% CI 14% to 45%) and median overall survival was 17.2 months.

CONCLUSIONS

We found weekly irinotecan 80 mg/m(2) plus TTD regimen (5-FU 2.25 g/m(2) given as 48-h i.v. infusion) to be a feasible and active combined chemotherapy for the first-line treatment of advanced colorectal cancer.