A gene transfer strategy for making bone marrow cells resistant to trimetrexate

Trimetrexate (TMTX) is an anticancer drug with potential advantages over the more commonly used antifolate, methotrexate (MTX); however, its use has been limited by severe myelosuppression. Retroviral vectors containing mutant dihydrofolate reductase (DHFR) genes have been used to protect bone marrow cells from MTX, suggesting a similar approach could be used for TMTX. We first screened six variants of human DHFR to determine which allowed maximal TMTX resistance in fibroblasts. A variant enzyme containing a Leu-to-Tyr mutation in the 22nd codon (L22Y) was best, allowing a 100-fold increase in resistance over controls. Murine hematopoietic progenitor cells transduced with an L22Y- containing retroviral vector also showed high-level TMTX resistance in vitro. Mice reconstituted with L22Y-transduced bone marrow cells were challenged with a 5-day course of TMTX to determine whether hematopoiesis could be protected in vivo. Transfer of the L22Y vector resulted in consistent protection from TMTX-induced neutropenia and reticulocytopenia at levels that correlated with the proviral copy number in circulating leukocytes. We conclude that the L22Y vector is highly effective in protecting hematopoiesis from TMTX toxicity and may provide a means for increasing the therapeutic utility of TMTX in certain cancers.     

Pulp revascularization for immature replanted teeth: a case report

Immature avulsed teeth are not usually treated with pulp revascularization because of the possibility of complications. However, this therapy has shown success in the treatment of immature teeth with periapical lesions. This report describes the case of an immature replanted tooth that was successfully treated by pulp revascularization. An 8‐year‐old boy suffered avulsion on his maxillary left lateral incisor. The tooth showed incomplete root development and was replanted after 30 minutes. After diagnosis, revascularization therapy was performed by irrigating the root canal and applying a calcium hydroxide paste and 2% chlorhexidine gel for 21 days. In the second session, the intracanal dressing was removed and a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate was placed as a cervical barrier at the entrance of the root canal and the crown was restored. During the follow‐up period, periapical repair, apical closure and calcification in the apical 4 mm of the root canal was observed. An avulsed immature tooth replanted after a brief extra‐alveolar period and maintained in a viable storage medium may be treated with revascularization.     

Flavocoxid,a dual inhibitor of cyclooxygenase and 5-lipoxygenase,blunts pro-inflammatory phenotype activation in endotoxin-stimulated macrophages

Background and purpose:

The flavonoids, baicalin and catechin, from Scutellaria baicalensis and Acacia catechu, respectively, have been used for various clinical applications. Flavocoxid is a mixed extract containing baicalin and catechin, and acts as a dual inhibitor of cyclooxygenase (COX) and 5-lipoxygenase (LOX) enzymes. The anti-inflammatory activity, measured by protein and gene expression of inflammatory markers, of flavocoxid in rat peritoneal macrophages stimulated with Salmonella enteritidis lipopolysaccharide (LPS) was investigated.

Experimental approach:

LPS-stimulated (1 µg·mL⁻¹) peritoneal rat macrophages were co-incubated with different concentrations of flavocoxid (32–128 µg·mL⁻¹) or RPMI medium for different incubation times. Inducible COX-2, 5-LOX, inducible nitric oxide synthase (iNOS) and inhibitory protein κB-α (IκB-α) levels were evaluated by Western blot analysis. Nuclear factor κB (NF-κB) binding activity was investigated by electrophoretic mobility shift assay. Tumour necrosis factor-α (TNF-α) gene and protein expression were measured by real-time polymerase chain reaction and enzyme-linked immunosorbent assay respectively. Finally, malondialdehyde (MDA) and nitrite levels in macrophage supernatants were evaluated.

Key results:

LPS stimulation induced a pro-inflammatory phenotype in rat peritoneal macrophages. Flavocoxid (128 µg·mL⁻¹) significantly inhibited COX-2 (LPS = 18 ± 2.1; flavocoxid = 3.8 ± 0.9 integrated intensity), 5-LOX (LPS = 20 ± 3.8; flavocoxid = 3.1 ± 0.8 integrated intensity) and iNOS expression (LPS = 15 ± 1.1; flavocoxid = 4.1 ± 0.4 integrated intensity), but did not modify COX-1 expression. PGE₂ and LTB₄ levels in culture supernatants were consequently decreased. Flavocoxid also prevented the loss of IκB-α protein (LPS = 1.9 ± 0.2; flavocoxid = 7.2 ± 1.6 integrated intensity), blunted increased NF-κB binding activity (LPS = 9.2 ± 2; flavocoxid = 2.4 ± 0.7 integrated intensity) and the enhanced TNF-α mRNA levels (LPS = 8 ± 0.9; flavocoxid = 1.9 ± 0.8 n-fold/β-actin) induced by LPS. Finally, flavocoxid decreased MDA, TNF and nitrite levels from LPS-stimulated macrophages.

Conclusion and implications:

Flavocoxid might be useful as a potential anti-inflammatory agent, acting at the level of gene and protein expression.     

Prognostic significance of DNA ploidy in Ta/Tl bladder cancer: A southwest oncology group study

While 80% of transitional cell carcinomas (TCC) present as Ta Tl lesions, they account for only 15% of deaths caused by TCC. We have evaluated the ability of DNA ploidy analysis to predict outcome in 228 patients with Ta Tl TCC. All patients were judged to be at increased risk for tumor recurrence due to having two occurrences of Stage TI tumor within 56 weeks, or three or more tumors presenting simultaneously within 16 weeks of registration. Concurrent carcinoma in situ was acceptable. All patients were treated with either bacillus Calmette Guerin (BCG) immunotherapy or mitomycin-C (MMC) intravesical chemotherapy. Patients with nondiploid tumors had higher hazard rates for both tumor progression and death (p = 0.007 and p = 0.016, respectively); however, the prognostic information of DNA ploidy was not additive to tumor grade.     

Immediate versus deferred androgen deprivation treatment in patients with node-positive prostate cancer after radical prostatectomy and pelvic lymphadenectomy

BACKGROUND: Appropriate timing of androgen deprivation treatment (ADT) for prostate cancer is controversial. Our aim was to determine whether immediate ADT extends survival in men with node-positive prostate cancer who have undergone radical prostatectomy and pelvic lymphadenectomy compared with those who received ADT only once disease progressed. METHODS: Eligible patients from 36 institutes in the USA were randomly assigned in 1988-93 to receive immediate ADT (n=47) or to be observed (n=51), with ADT to be given on detection of distant metastases or symptomatic recurrences. Patients were followed up every 3 months for the first year and every 6 months thereafter. The primary endpoint was progression-free survival; secondary endpoints were overall and disease-specific survival. Analysis was by intention to treat. To ensure that the treatment groups were comparable, we did a retrospective central pathology review of slides and regraded the Gleason scores for available samples. This trial predates the requirement for clinical trial registration. FINDINGS: At median follow-up of 11.9 years (range 9.7-14.5 for surviving patients), men assigned immediate ADT had a significant improvement in overall survival (hazard ratio 1.84 [95% CI 1.01-3.35], p=0.04), prostate-cancer-specific survival (4.09 [1.76-9.49], p=0.0004), and progression-free survival (3.42 [1.96-5.98], p<0.0001). Of 49 histopathology slides received (19 immediate ADT, 30 observation), 16 were downgraded from the original Gleason score (between groups < or = 6, 7, and > or = 8) and five were upgraded. We recorded similar proportions of score changes in each group (p=0.68), and no difference in score distribution by treatment (p=0.38). After adjustment for score, associations were still significant between treatment and survival (overall, p=0.02; disease-specific, p=0.002; progression-free survival, p<0.0001). INTERPRETATION: Early ADT benefits patients with nodal metastases who have undergone prostatectomy and lymphadenectomy, compared with those who receive deferred treatment. The beneficial effects of early ADT, rather than an imbalance in risk factors, are likely to explain the differences in outcomes between treatments.     

Neoadjuvant gemcitabine and cisplatin chemotherapy for locally advanced urothelial cancer of the bladder

BACKGROUND:

The purpose of this study was to investigate the effect of neoadjuvant chemotherapy with gemcitabine and cisplatin (GC) on pathologic down‐staging of patients with locally advanced urothelial cancer (UC) of the bladder.

METHODS:

This was a retrospective cohort study of patients treated with radical cystectomy (RC) for clinical stage cT2‐T4, N any, M0 bladder UC at Strong Memorial Hospital from 1999 to 2009. The primary exposure variable was use of neoadjuvant chemotherapy (GC vs none). The primary outcome was stage pT0 at RC. Secondary outcomes included other down‐staging end points in the bladder ( RESULTS: A total of 160 eligible patients were identified, of whom 25 were treated with neoadjuvant GC before RC (GC + RC) and 135 without neoadjuvant chemotherapy (RC only). Stage pT0 at cystectomy was found in 20% of patients in the GC + RC group and in 5% of patients in the RC group (adjusted risk difference [aRD] = 16%, P = .03). For other down‐staging end points, the estimated treatment effect was as follows (all point estimates favoring chemotherapy): P = .005); P = .004); P = .008); margins aRD = 8% (P = .41); nodes aRD = 4% (P = .74).

CONCLUSIONS:

Neoadjuvant GC was found to be capable of down‐staging UC in the bladder; however, no effect on disease in nodes was seen in this study. Cancer 2012;. © 2011 American Cancer Society.