Leucovorin and Fluorouracil With or Without Oxaliplatin as First-Line Treatment in Advanced Colorectal Cancer.

PURPOSE: In a previous study of treatment for advanced colorectal cancer, the LV5FU2 regimen, comprising leucovorin (LV) plus bolus and infusional fluorouracil (5FU) every 2 weeks, was superior to the standard North Central Cancer Treatment Group/Mayo Clinic 5-day bolus 5FU/LV regimen. This phase III study investigated the effect of combining oxaliplatin with LV5FU2, with progression-free survival as the primary end point. PATIENTS AND METHODS: Four hundred twenty previously untreated patients with measurable disease were randomized to receive a 2-hour infusion of LV (200 mg/m2/d) followed by a 5FU bolus (400 mg/m2/d) and 22-hour infusion (600 mg/m2/d) for 2 consecutive days every 2 weeks, either alone or together with oxaliplatin 85 mg/m2 as a 2-hour infusion on day 1. RESULTS: Patients allocated to oxaliplatin plus LV5FU2 had significantly longer progression-free survival (median, 9.0 v 6.2 months; P = .0003) and better response rate (50.7% v 22.3%; P = .0001) when compared with the control arm. The improvement in overall survival did not reach significance (median, 16.2 v 14.7 months; P = .12). LV5FU2 plus oxaliplatin gave higher frequencies of National Cancer Institute common toxicity criteria grade 3/4 neutropenia (41.7% v 5.3% of patients), grade 3/4 diarrhea (11.9% v 5.3%), and grade 3 neurosensory toxicity (18.2% v 0%), but this did not result in impairment of quality of life (QoL). Survival without disease progression or deterioration in global health status was longer in patients allocated to oxaliplatin treatment (P = .004). CONCLUSION: The LV5FU2-oxaliplatin combination seems beneficial as first-line therapy in advanced colorectal cancer, demonstrating a prolonged progression-free survival with acceptable tolerability and maintenance of QoL.

A modular spring-loaded actuator for mechanical activation of membrane proteins.

How cells respond to mechanical forces by converting them into biological signals underlie crucial cellular processes. Our understanding of mechanotransduction has been hindered by technical barriers, including limitations in our ability to effectively apply low range piconewton forces to specific mechanoreceptors on cell membranes without laborious and repetitive trials. To overcome these challenges we introduce the Nano-winch, a robust, easily assembled, programmable DNA origami-based molecular actuator. The Nano-winch is designed to manipulate multiple mechanoreceptors in parallel by exerting fine-tuned, low- piconewton forces in autonomous and remotely activated modes via adjustable single- and double-stranded DNA linkages, respectively. Nano-winches in autonomous mode can land and operate on the cell surface. Targeting the device to integrin stimulated detectable downstream phosphorylation of focal adhesion kinase, an indication that Nano-winches can be applied to study cellular mechanical processes. Remote activation mode allowed finer extension control and greater force exertion. We united remotely activated Nano-winches with single-channel bilayer experiments to directly observe the opening of a channel by mechanical force in the force responsive gated channel protein, BtuB. This customizable origami provides an instrument-free approach that can be applied to control and explore a diversity of mechanotransduction circuits on living cells.

An achiral ferromagnetic/chiral antiferromagnetic bilayer system leading to controllable size and density of skyrmions.

Magnetic skyrmions are topologically protected domain structures related to the Dzyaloshinskii-Moriya interaction (DMI). To understand how magnetic skyrmions occur under different circumstances, we propose a model for skyrmion formation in a bilayer system of ferromagnetic/antiferromagnetic (FM/AFM) films, in which the bulk DMI is only present in the AFM film. Micromagnetic simulations reveal that skyrmions are formed in this system due to the competition between the DMI and demagnetization energies. A critical interfacial exchange energy (Ai = 6.5 mJ/m2) is determined, above which the competition occurs at its full extent. More skyrmions are formed with increasing external magnetic field till a critical value above which the external field is too large and thus leading to the annihilation of skyrmions. The spacing between two skyrmions can be as small as 45 nm. Our results may give technological implications for future skyrmion applications.

5-year overall survival after early breast cancer diagnosed during pregnancy: A retrospective case-control multicentre French study.

BACKGROUND: Breast cancer diagnosed during pregnancy (BCP) is rare, but the prevalence is expected to rise. Long-term follow-up data regarding this clinically challenging condition are scarce. The main objective of this multicentre case-control French study was to compare the survival between pregnant patients and matched controls. METHODS: Patients from 27 centres diagnosed between 2000 and 2009 with histologically proven invasive breast cancer occurring during pregnancy were retrospectively included. Controls were matched to BCP patients on age, clinical T stage, hormone receptor, HER2, administration of neo-adjuvant chemotherapy and pathological node involvement in the absence of neo-adjuvant chemotherapy. Five-year overall survival (OS), disease-free survival (DFS) and metastasis-free survival (MFS) rates were estimated using the Kaplan-Meier method. RESULTS: One hundred and eleven BCP patients and 253 controls were included. Median age was 33 and 35 years, respectively. Both populations were managed similarly, except for less frequent sentinel node dissection (p = 0.026) and taxane administration (p = 0.03) among BCP patients. Median follow-up was 7.5 years. Survival rates were similar between both BCP and control patients: 5-year OS rates were 83.1% (95% CI: 74.5-89.0) vs 85.5% (95% CI: 80.4-89.4), respectively, p = 0.31; 5-year DFS rates 60.0% (95% CI: 50.1-68.6) vs 68.5% (95% CI: 62.3-73.9), respectively, p = 0.12 and 5-year MFS rates 71.0% (95% CI: 61.3-78.6) and 74.5% (95% CI: 68.6-79.5), respectively, p = 0.21. CONCLUSION: Our study showed that the survival outcomes of patients diagnosed with BCP were not significantly different as compared to those of matched non-pregnant controls. A proper management of women diagnosed with BCP is crucial.

Lipophilic pro-oligonucleotides are rapidly and efficiently internalized in HeLa cells.

Model t-Bu-SATE pro-dodecathymidines labeled with fluorescein and exhibiting various lipophilicities were evaluated for their uptake by cells in culture. Pro-oligonucleotides with appropriate lipophilicity were found to permeate across the HeLa cell membrane much more extensively than the control phosphorothioate oligo or than the hydrophilic pro-oligos. Fluorescence patterns of internalization were consistent with a diffusion mechanism resulting in the appearance of a uniform cytoplasmic distribution and nuclear accumulation, as confirmed by confocal microscopy.

Rapid determination of the affinity of 28- and 14-mer phosphorothioate oligonucleotides for HIV-1 reverse transcriptase by fluorescence spectroscopy.

Intrinsic fluorescence of human immunodeficiency virus type 1 reverse transcriptase (E.C. 2.7.7.49) and displacement experiments of a fluorescent template.primer probe were used to study the interaction of the enzyme with several types of 28- and 14-mer normal or phosphorothioate oligodeoxycytidinylates and their duplexes with poly(rI). The two methods gave convergent results and allowed in each case fast determinations of ligand affinities for the enzyme. The dissociation constants (Kd) obtained from intrinsic fluorescence changes were slightly lower than those determined from the less direct competitive displacement experiments. In all cases, the enzyme displayed better recognition of the hybrid than of the unannealed oligonucleotide. The Kd values of phosphorothioate oligomers and their hybrids were lower than those of the corresponding normal oligomers and hybrids, but the difference was not as significant as in the case of the Ki constants for (dC)28 and S(dC)28 (Majumdar et al. (1989) Biochemistry 28, 1340). The affinities of the annealed phosphorothioate oligodeoxycytidinylates for the enzyme were found to be larger than for any other compounds in this series (Kd of poly(rI).S(dC)28: 0.28 nM at 25 degrees C). Changing the beta stereochemistry of the oligomer bases to alpha did not alter the affinity of the oligodeoxycytidinylate and its hybrids for the enzyme.

Efficacy and tolerance of vinorelbine and fluorouracil combination as first-line chemotherapy of advanced breast cancer: results of a phase II study using a sequential group method.

PURPOSE: To assess the antitumor efficacy and safety profile of the combination of Fluorouracil (5FU) and vinorelbine given as first-line therapy to patients with advanced breast cancer. PATIENTS AND METHODS: As defined in the seven consecutive steps of a phase II group sequential design, 63 patients received 5FU 750 mg/m2/d for 5 consecutive days as a continuous infusion and vinorelbine 30 mg/ m2 on days 1 and 5 as a short intravenous (I/V) infusion every 3 weeks. RESULTS: Forty-one of 63 patients achieved an objective response, which allowed us to discontinue the study and reject a response rate less than 50% with a statistical power of 90%. The unbiased estimate of the response rate was 61.6%. Response rate did not differ significantly according to the following: (1) type of prior adjuvant therapy (none, n = 23; without anthracycline, n = 6; with anthracyline, n = 34); (2) site of metastatic disease; and (3) number of metastatic sites. The median time to progression was 8.4 months. The median response duration was 12.3 months, and the median duration of complete response (CR), from the first assessment of CR, was 7.3 months. The median overall survival time was 23 months (28.1 months for patients with a CR). The main toxicities (grades 3 and 4) were neutropenia (90% of patients), infection (12.7%), mucositis (37%), and constipation (9.5%). Nevertheless, treatment could be given on an outpatient basis to the majority of patients, and the median relative dose-intensity was 86%. CONCLUSION: This phase II study, which used a group-sequential design, shows that the combination of 5FU and vinorelbine is an active and tolerable regimen for the treatment of first metastatic progression of breast cancer. It provides an alternative regimen for patients who have previously received anthracycline-based adjuvant chemotherapy or in whom anthracyclines cannot be used.

Randomized trial comparing monthly low-dose leucovorin and fluorouracil bolus with bimonthly high-dose leucovorin and fluorouracil bolus plus continuous infusion for advanced colorectal cancer: a French intergroup study.

PURPOSE: This multicenter study compared the therapeutic ratio of a monthly schedule of low-dose leucovorin (LV) and fluorouracil (5-FU) bolus with a bimonthly schedule of high-dose LV and 5-FU bolus plus continuous infusion in patients with advanced colorectal cancer. PATIENTS AND METHODS: Of the 448 patients randomly assigned to treatment, 433 were assessable. Treatment A was a monthly regimen of intravenous (IV) LV 20 mg/m2 plus bolus 5-FU 425 mg/m2 for 5 days every 4 weeks. Treatment B was a bimonthly regimen of IV LV 200 mg/m2 as a 2-hour infusion followed by bolus 5-FU 400 mg/m2 and 22-hour infusion 5-FU 600 mg/m2 for 2 consecutive days every 2 weeks. Therapy was continued until disease progression. Second-line chemotherapy, which included 5-FU continuous infusion, was allowed in both arms. RESULTS: The response rates in 348 patients with measurable lesions were 14.4% (monthly regimen) and 32.6% (bimonthly regimen) (P = .0004). The median progression-free survival times were 22 weeks (monthly regimen) and 27.6 weeks (bimonthly regimen) (P = .0012). The median survival times were 56.8 weeks (monthly regimen) and 62 weeks (bimonthly regimen) (P = .067). Grade 3-4 toxicities occurred in 23.9% of patients in the monthly arm compared with 11.1% of those in the bimonthly arm (P = .0004). Patients in arm A more frequently experienced severe granulocytopenia (7.3% v 1.9%), diarrhea (7.3% v 2.9%), and mucositis (7.3% v 1.9%) than patients in arm B. CONCLUSION: The bimonthly regimen was more effective and less toxic than the monthly regimen and definitely increased the therapeutic ratio. However, there was no evidence of increased survival.

Epirubicin plus tamoxifen versus tamoxifen alone in node-positive postmenopausal patients with breast cancer: A randomized trial of the International Collaborative Cancer Group.

PURPOSE: To assess whether the addition of epirubicin (EPI) therapy to prolonged treatment with tamoxifen (TAM) improves relapse-free and overall survival in postmenopausal women with node-positive primary breast cancer. PATIENTS AND METHODS: Six hundred four patients entered onto a randomized clinical trial were allocated to receive TAM 20 mg/d for 4 years or TAM 20 mg/d for 4 years plus EPI 50 mg/m(2) intravenously on days 1 and 8 every 4 weeks for six cycles. Analysis was performed according to allocated treatment, with all randomized patients included (intention to treat), irrespective of eligibility status. RESULTS: After a median follow-up period of 5.7 years, an improvement in relapse-free survival (RFS) was observed for the TAM and EPI-treated patients, compared with those who received TAM alone. The unadjusted hazard ratio was 0.72 (95% confidence interval, 0.54 to 0.96), with a corresponding reduction in the odds of recurrence of 27.9% (SD, 12. 3), which was statistically significant (P =.023). Adjustment for prognostic and/or predictive factors did not materially affect the hazard ratio. No difference was observed in terms of overall survival (reduction in odds of death, 11.9% [SD, 16.3]; P =.46). Combined chemohormonal treatment was associated with a higher incidence of acute side effects but without a clear increase in long-term cardiotoxicity. Twelve nonbreast second malignancies, including five hematologic malignancies (two of which were cases of acute myelogenous leukemia), were observed. CONCLUSION: The data show that combined chemohormonal treatment reduces the risk of relapse in postmenopausal patients with node-positive breast cancer. No evidence was found, however, for an improvement in overall survival. The size of benefit observed for both outcomes was consistent with that reported in the Early Breast Cancer Trialists' Collaborative Group overview. The trial presented here, however, provides the first report of an improvement in RFS associated with the provision of a single cytotoxic drug in addition to prolonged TAM.

Concomitant chemoradiotherapy followed, where feasible, by surgery for cancer of the esophagus.

PURPOSE: To conduct a multicenter phase II study of a concomitant combination of chemotherapy and radiotherapy followed by surgery, where feasible, in patients with nonmetastatic esophageal tumor, stratified on operability at diagnosis. METHODS: Each cycle consisted of fluorouracil (5FU) 800 mg/m2/d by continuous intravenous (IV) infusion on days 1 to 5, cisplatin (CDDP) 50 mg/m2/d IV bolus on days 1 and 8, hydroxyurea (HU) 1.5 or 2 g/d orally on days 8 to 12 and concomitant radiotherapy 20 Gy in 10 fractions over 12 days. All patients were to receive two cycles on days 1 and 22. If feasible, surgery was performed 3 to 6 weeks after cycle two completion. Otherwise, a third cycle was administered. RESULTS: Eighty-eight patients were included between September 1990 and September 1993. Of the 47 operable patients, 41 (87%) underwent surgery and 38 (81%) had a complete resection. No residual primary tumor was found in the surgical specimen in 17 cases (36%), and only microscopic foci in 13 (28%). Two-year overall and disease-free survival probabilities were 51% (95% confidence interval [CI]; 37 to 65) and 43% (95% CI, 28 to 57), respectively. Among the 41 inoperable patients, 12 (29%) became operable. Seven (17%) had complete resection, two incomplete resection, and three exploratory surgery. Two-year overall and disease-free survival probabilities were 29% (95% CI, 15 to 43) and 27% (95% CI, 13 to 40), respectively. Five deaths occurred during chemoradiotherapy, six postoperatively and four in patients with evidence of cancer. Five late complications (one myelopathy) were observed. CONCLUSION: Despite a high histologic response rate in initially operable patients, overall survival was similar to that observed in other preoperative chemoradiation series because of substantial toxicity.

Multicenter phase II study of bimonthly high-dose leucovorin, fluorouracil infusion, and oxaliplatin for metastatic colorectal cancer resistant to the same leucovorin and fluorouracil regimen.

PURPOSE: To evaluate the objective tumor response rates and toxicities of leucovorin (LV) plus fluorouracil (5-FU) cancer regimen combined with oxaliplatin (85 mg/m(2)) every 2 weeks on metastatic colorectal cancer patients with documented proof of progression while on bimonthly LV and 5-FU alone. PATIENTS AND METHODS: One hundred patients were enrolled onto this study and 97 received the study drugs between October 1995 and December 1996. Eighty-nine patients were eligible for per-protocol efficacy analysis with documented proof of progression on one of the following two treatments: LV 500 mg/m(2) and continuous 5-FU infusion 1.5 to 2 g/m(2)/22 hours, days 1 through 2 every 2 weeks (FOLFUHD); or LV 200 mg/m(2), bolus 5-FU 400 mg/m(2), and continuous 5-FU infusion 600 mg/m(2)/22 hours, days 1 through 2 every 2 weeks (LV5FU2). In our study, 40 patients received FOLFUHD + 85 mg/m(2) of oxaliplatin day 1 (FOLFOX3) and 57 patients received LV5FU2 + 85 mg/m(2) of oxaliplatin day 1 (FOLFOX4). RESULTS: Of the 97 patients treated, 20 partial responses were observed (FOLFOX3/4: response rate, 20.6%; 95% confidence interval, 13% to 31.1%; FOLFOX3: response rate,18.4%; FOLFOX4: response rate, 23.5%). For patients treated with FOLFOX3/4, the median response duration for was 7.5 months, and the major toxicities were peripheral neuropathy and neutropenia. The incidence of grade 3 (National Cancer Institute common toxicity criteria) peripheral neuropathy was 20.6%; whereas the overall incidence of grade 3 to 4 neutropenia was 27.8%, 15%, and 36.9% for FOLFOX3/4, FOLFOX3, and FOLFOX4, respectively (P =.02). From the start of treatment, median progression-free survival was 4. 7, 4.6, and 5.1 months for FOLFOX3/4, FOLFOX3, FOLFOX4, respectively, and median overall survival was 10.8, 10.6, and 11.1 months, respectively. CONCLUSION: This phase II study of oxaliplatin at 85 mg/m(2) in combination with bimonthly LV plus 5-FU in patients with colorectal cancer resistant to LV plus 5-FU alone confirms the enhanced antitumor activity of oxaliplatin in combination with 5-FU.

Adjuvant cyclophosphamide, methotrexate, and fluorouracil versus fluorouracil, epirubicin, and cyclophosphamide chemotherapy in premenopausal women with axillary node-positive operable breast cancer: results of a randomized trial. The International Collaborative Cancer Group.

PURPOSE: To determine whether a combination chemotherapy regimen that contains epirubicin (fluorouracil, epirubicin, and cyclophosphamide [FEC]) is superior to the standard cyclophosphamide, methotrexate, and fluorouracil (CMF) combination in premenopausal women with axillary node-positive operable breast cancer. PATIENTS AND METHODS: The International Collaborative Cancer Group (ICCG) conducted a large randomized trial in which two alternative schedules were used according to participating center: CMF1 versus FEC1 and CMF2 versus FEC2. RESULTS: Seven hundred fifty-nine patients were entered onto the trial. At a median follow-up time of 4.5 years, no significant benefit for the anthracycline-containing regimen was observed in terms of relapse-free (P = .61) or overall survival (P = .13). FEC1 and CMF1 appear to be of similar efficacy, but there is a suggestion that FEC2 may be superior to CMF2, since patients who received FEC2 had improved overall (P = .02) and relapse-free survival (P = .03) rates. Nausea and vomiting and alopecia were more common in the epirubicin-containing regimen (P = .001). CONCLUSION: We conclude that the FEC2 regimen, in which epirubicin replaced the methotrexate in CMF, is the preferable adjuvant chemotherapy regimen for premenopausal patients with operable axillary node-positive breast cancer.

Leucovorin and fluorouracil with or without oxaliplatin as first-line treatment in advanced colorectal cancer.

PURPOSE: In a previous study of treatment for advanced colorectal cancer, the LV5FU2 regimen, comprising leucovorin (LV) plus bolus and infusional fluorouracil (5FU) every 2 weeks, was superior to the standard North Central Cancer Treatment Group/Mayo Clinic 5-day bolus 5FU/LV regimen. This phase III study investigated the effect of combining oxaliplatin with LV5FU2, with progression-free survival as the primary end point. PATIENTS AND METHODS: Four hundred twenty previously untreated patients with measurable disease were randomized to receive a 2-hour infusion of LV (200 mg/m(2)/d) followed by a 5FU bolus (400 mg/m(2)/d) and 22-hour infusion (600 mg/m(2)/d) for 2 consecutive days every 2 weeks, either alone or together with oxaliplatin 85 mg/m(2) as a 2-hour infusion on day 1. RESULTS: Patients allocated to oxaliplatin plus LV5FU2 had significantly longer progression-free survival (median, 9.0 v 6.2 months; P =.0003) and better response rate (50.7% v 22.3%; P =.0001) when compared with the control arm. The improvement in overall survival did not reach significance (median, 16.2 v 14.7 months; P =. 12). LV5FU2 plus oxaliplatin gave higher frequencies of National Cancer Institute common toxicity criteria grade 3/4 neutropenia (41. 7% v 5.3% of patients), grade 3/4 diarrhea (11.9% v 5.3%), and grade 3 neurosensory toxicity (18.2% v 0%), but this did not result in impairment of quality of life (QoL). Survival without disease progression or deterioration in global health status was longer in patients allocated to oxaliplatin treatment (P =.004). CONCLUSION: The LV5FU2-oxaliplatin combination seems beneficial as first-line therapy in advanced colorectal cancer, demonstrating a prolonged progression-free survival with acceptable tolerability and maintenance of QoL.

A new approach to treat tissue destruction in periodontitis with chemically modified dextran polymers.

Periodontitis are diseases of the supportive tissues of the teeth provoked by bacteria and characterized by gingival inflammation and bone destruction. We have developed a new strategy to repair tissues by administrating agents (RGTA) that mimic heparan sulfates by protecting selectively some of the growth factors naturally present within the injured tissue and interfering with inflammation. After periodontitis induction in hamsters, the animals were left untreated or received weekly i.m. injections of RGTA1507 at a dose of 100 microg/kg, 400 microg/kg, 1.5 mg/kg, or 15 mg/kg for 4 wk. RGTA treatment significantly reduced gingival tissue inflammation, thickened the pocket epithelium by increasing cell proliferation, and enhanced collagen accumulation in the gingiva. A marked reduction in bone loss was observed, resulting from depression of osteoclasia and robust stimulation of bone formation at the dose of 1.5 mg/kg. RGTA treatment for 8 wk at this dose reversed macroscopic bone loss, sharply contrasting with the extensive bone destruction in the untreated animals. RGTA treatment decreased gelatinase A (MMP-2) and B (MMP-9) pro-forms in gingival tissues. Our data indicate that a 4 wk treatment dose-dependently attenuated gingival and bone manifestations of the disease, whereas a longer treatment restored alveolar bone close to controls. By modulating and coordinating host responses, RGTA has unique therapeutic properties and is a promising candidate for the treatment of human periodontitis.

Deterioration of the coercivity due to the diffusion induced interface layer in hard/soft multilayers.

Hard/soft permanent magnets have aroused many interests in the past two decades because of their potential in achieving giant energy products as well as their rich variety of magnetic behaviors. Nevertheless, the experimental energy products are much smaller than the theoretical ones due to the much smaller coercivity measured in the experiments. In this paper, the deterioration of the coercivity due to the interface atomic diffusion is demonstrated based on a three dimensional (3D) micromagnetic software (OOMMF) and a formula derived for the pinning field in a hard/soft multilayer, which can be applied to both permanent magnets and exchange-coupled-composite (ECC) media. It is found that the formation of the interface layer can decrease the coercivity by roughly 50%, which is responsible for the observed smaller coercivity in both composite and single-phased permanent magnets. A method to enhance the coercivity in these systems is proposed based on the discussions, consistent with recent experiments where excellent magnetic properties are achieved.

Skyrmion-skyrmion and skyrmion-edge repulsions in skyrmion-based racetrack memory.

Magnetic skyrmions are promising for building next-generation magnetic memories and spintronic devices due to their stability, small size and the extremely low currents needed to move them. In particular, skyrmion-based racetrack memory is attractive for information technology, where skyrmions are used to store information as data bits instead of traditional domain walls. Here we numerically demonstrate the impacts of skyrmion-skyrmion and skyrmion-edge repulsions on the feasibility of skyrmion-based racetrack memory. The reliable and practicable spacing between consecutive skyrmionic bits on the racetrack as well as the ability to adjust it are investigated. Clogging of skyrmionic bits is found at the end of the racetrack, leading to the reduction of skyrmion size. Further, we demonstrate an effective and simple method to avoid the clogging of skyrmionic bits, which ensures the elimination of skyrmionic bits beyond the reading element. Our results give guidance for the design and development of future skyrmion-based racetrack memory.

Alpha-anomeric DNA: beta-RNA hybrids as new synthetic inhibitors of Escherichia coli RNase H, Drosophila embryo RNase H and M-MLV reverse transcriptase.

Nuclease-resistant alpha-anomeric DNA:beta-RNA hybrids are inhibitors of Escherichia coli RNase H, and Drosophila embryo RNase H. RNase H activities were measured by polyacrylamide gel electrophoresis, employing a short substrate, (A)12:d[G-G-(T)12-G-G], or by acid-solubility techniques, using a long substrate, poly(A):poly(dT). Strand exchanges which could be responsible for the observed inhibition have been ruled out by S1 nuclease experiments and by using inhibitors which do not allow strand exchange. Our results suggest that RNase H, for which DNA:RNA duplexes are the natural substrates, binds to non-physiological alpha-DNA:RNA hybrids and is consequently inhibited. These hybrids also inhibit the RNA-dependent DNA polymerase activity of M-MLV reverse transcriptase, therefore appearing as potential inhibitors of at least two reverse transcriptase activities. However, the inhibitory effect of these hybrids with respect to M-MLV reverse transcriptase is also observed with the single-stranded alpha-DNA itself. Unexpectedly, polymerase activity is highly stimulated by alpha-oligos, analogous in their sequence to the beta primer used at a concentration unable to generate a detectable synthesis. These results suggest that the inhibition of reverse transcriptase activity with the alpha:beta may occur at different levels.

5-Fluorouracil (5-FU) continuous intravenous infusion compared with bolus administration. Final results of a randomised trial in metastatic colorectal cancer.

The aim of this Phase III, balanced randomised trial was to compare continuous intravenous infusion (CVI) of 5-FU with bolus (B) administration for metastatic colorectal cancer (CRC). One hundred and fifty-five non-pretreated patients were randomised to receive CVI 5-FU at a dose of 750 mg/m2/day (d), 7 d every 21 d (n = 77), or bolus 5-FU 500 mg/m2/d x 5 d every 28 d (n = 78). Incremental dose escalation at 50 mg per step was recommended in the absence of toxicity. All the patients had measurable metastatic disease (M), particularly, liver and a good performance status (WHO grade 0-1). Dose intensity was significantly higher in CVI than in the bolus group: 1369 mg/m2/week versus 558 mg/m2/week (P = 0.0001). Grade II-IV stomatitis was more frequent in the CVI group (31% versus 9%; P < 0.0001) as was hand and foot syndrome (14% versus 3%; P < 0.001). Diarrhoea (22% versus 12%) and grade III granulocytopenia (2% versus 6%) were comparable. Responses were more frequent in the CVI (26%) than in the bolus group (13%) (P < 0.04); progression-free survival was higher for the CVI group (P = 0.04), but there was no statistical difference in overall survival (median: 10 months (m) compared to 9 m), and 1 year survival (SD) 42% (6%) versus 40% (6%). In the multivariate analysis, survival was better for patients with a good PS, well-differentiated adenocarcinomas and a primary tumour without serosal extension. In conclusion, with a higher dose intensity, CVI 5-FU improved tumour control, but not overall survival.

Alpha are more stable than beta anomer oligonucleotides in 3T3 cellular extracts.

We have compared the stability of alpha and beta anomeric oligonucleotides in NIH 3T3 cellular extracts. We had already shown that alpha are much more resistant than beta oligonucleotides towards purified nucleases. This result is confirmed when using cellular extracts although the difference is smaller. When alpha molecules are combined with an intercalating agent binding in the 3' position a synergistic increase of resistance to degradation is observed.

Phase II randomized study of paclitaxel versus mitomycin in advanced breast cancer.

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) has been shown to be an effective agent in the treatment of metastatic breast carcinoma. This multicenter randomized study compared paclitaxel 175 mg/m2 given as a 3-hour infusion every 3 weeks with mitomycin 12 mg/m2 given as an intravenous infusion every 6 weeks. Eighty-one patients have been randomized, and preliminary results of a planned analysis of the first 36 evaluable patients per arm are reported. Pretreatment characteristics were well balanced between the two groups. All patients previously have received chemotherapy for metastatic disease, and half had both adjuvant therapy and chemotherapy for metastatic disease. All but one patient previously had received anthracyclines. Of the first 81 randomized patients, 72 were evaluable for response and toxicity (four never treated, five concomitant hormonotherapy). Partial responses were seen in 17% of patients in the paclitaxel arm and 6% in the mitomycin arm (P = .14). Crossover to paclitaxel therapy following progression on mitomycin achieved an objective response rate of 24% (five of 21 patients). Responses to paclitaxel therapy lasted for a median duration of 9.1 months (range, 6.2 to 12+ months). Median time to progression was significantly longer in the paclitaxel arm (3.5 months v 1.6 months; P = .026). The quality-of-life-adjusted analysis confirmed the advantage of paclitaxel therapy, even when the delay of disease progression was adjusted for important adverse events. Adverse events, most importantly neutropenia and neuropathy, were more frequently observed in the paclitaxel arm. However, patients remained on paclitaxel therapy for many more courses than did those treated in the mitomycin arm. In conclusion, paclitaxel 175 mg/m2 given as a 3-hour intravenous infusion has been demonstrated to be an active agent in the treatment of chemotherapy-refractory advanced breast cancer, even after therapy with mitomycin has failed.