Understanding the mechanisms that promote aberrant tumour cell survival is critical for the determination of novel strategies to combat colorectal cancer (CRC). We have recently shown that the ...anti-apoptotic protein BAG-1, highly expressed in pre-malignant and CRC tissue, can potentiate cell survival through regulating NF-κB transcriptional activity. In this study, we identify a novel complex between BAG-1 and the p50-p50 NF-κB homodimers, implicating BAG-1 as a co-regulator of an atypical NF-κB pathway. Importantly, the BAG-1-p50 complex was detected at gene regulatory sequences including the epidermal growth factor receptor (EGFR) and COX-2 (PTGS2) genes. Suppression of BAG-1 expression using small interfering RNA was shown to increase EGFR and suppress COX-2 expression in CRC cells. Furthermore, mouse embryonic fibroblasts derived from the NF-κB1 (p105/p50) knock-out mouse were used to demonstrate that p50 expression was required for BAG-1 to suppress EGFR expression. This was shown to be functionally relevant as attenuation of BAG-1 expression increased ligand activated phosphorylation of EGFR in CRC cells. In summary, this paper identifies a novel role for BAG-1 in modulating gene expression through interaction with the p50-p50 NF-κB complexes. Data presented led us to propose that BAG-1 can act as a selective regulator of p50-p50 NF-κB responsive genes in colorectal tumour cells, potentially important for the promotion of cell survival in the context of the fluctuating tumour microenvironment. As BAG-1 expression is increased in the developing adenoma through to metastatic lesions, understanding the function of the BAG-1-p50 NF-κB complexes may aid in identifying strategies for both the prevention and treatment of CRC.. PUBLICATION ABSTRACT
Understanding the mechanisms that promote aberrant tumour cell survival is critical for the determination of novel strategies to combat colorectal cancer (CRC). We have recently shown that the ...anti-apoptotic protein BAG-1, highly expressed in pre-malignant and CRC tissue, can potentiate cell survival through regulating NF-κB transcriptional activity. In this study, we identify a novel complex between BAG-1 and the p50-p50 NF-κB homodimers, implicating BAG-1 as a co-regulator of an atypical NF-κB pathway. Importantly, the BAG-1-p50 complex was detected at gene regulatory sequences including the epidermal growth factor receptor (EGFR) and COX-2 (PTGS2) genes. Suppression of BAG-1 expression using small interfering RNA was shown to increase EGFR and suppress COX-2 expression in CRC cells. Furthermore, mouse embryonic fibroblasts derived from the NF-κB1 (p105/p50) knock-out mouse were used to demonstrate that p50 expression was required for BAG-1 to suppress EGFR expression. This was shown to be functionally relevant as attenuation of BAG-1 expression increased ligand activated phosphorylation of EGFR in CRC cells. In summary, this paper identifies a novel role for BAG-1 in modulating gene expression through interaction with the p50-p50 NF-κB complexes. Data presented led us to propose that BAG-1 can act as a selective regulator of p50-p50 NF-κB responsive genes in colorectal tumour cells, potentially important for the promotion of cell survival in the context of the fluctuating tumour microenvironment. As BAG-1 expression is increased in the developing adenoma through to metastatic lesions, understanding the function of the BAG-1-p50 NF-κB complexes may aid in identifying strategies for both the prevention and treatment of CRC.
The aim was to determine whether Bcl-2-associated athanogene-1 (Bag-1) and/or its binding protein heat shock protein-70 (Hsp70) exhibit deregulated expression in epidermal squamous cell carcinoma ...(SCC) and whether Bag-1 confers apoptosis resistance.
Immunohistochemistry for Bag-1 and Hsp70 was performed on 60 epidermal SCC and 10 normal skin samples. The epidermal SCC cell line SCC-13 was treated with 5-fluorouracil (5-FU) after Bag-1 knockdown to determine whether high Bag-1 levels contribute to growth and/or apoptosis resistance.
Normal epithelium expressed primarily nuclear Bag-1. Most tumours showed reduced nuclear Bag-1 staining, but a subset exhibited strong Bag-1 staining, with cytoplasmic Bag-1 staining intensity correlating with cytoplasmic Hsp70 staining intensity (r(s)=0.462; P<0.001) and less differentiation (P<0.001). Bag-1 knockdown resulted in markedly reduced SCC-13 cell yield, increased spontaneous apoptosis and enhanced sensitivity to 5-FU-induced apoptosis. Apoptosis induced by 5-FU in the Bag-1-knockdown cells was significantly greater than the additive apoptotic effect of 5-FU or Bag-1 knockdown alone.
Overexpression of Bag-1 and Hsp70 in poorly differentiated SCC may confer both enhanced tumour cell growth and apoptosis resistance. Bag-1 may contribute to the resistance of more advanced epidermal SCC to chemotherapy.
Lumbar-disk surgery often is performed in patients who have sciatica that does not resolve within 6 weeks, but the optimal timing of surgery is not known.
We randomly assigned 283 patients who had ...had severe sciatica for 6 to 12 weeks to early surgery or to prolonged conservative treatment with surgery if needed. The primary outcomes were the score on the Roland Disability Questionnaire, the score on the visual-analogue scale for leg pain, and the patient's report of perceived recovery during the first year after randomization. Repeated-measures analysis according to the intention-to-treat principle was used to estimate the outcome curves for both groups.
Of 141 patients assigned to undergo early surgery, 125 (89%) underwent microdiskectomy after a mean of 2.2 weeks. Of 142 patients designated for conservative treatment, 55 (39%) were treated surgically after a mean of 18.7 weeks. There was no significant overall difference in disability scores during the first year (P=0.13). Relief of leg pain was faster for patients assigned to early surgery (P<0.001). Patients assigned to early surgery also reported a faster rate of perceived recovery (hazard ratio, 1.97; 95% confidence interval, 1.72 to 2.22; P<0.001). In both groups, however, the probability of perceived recovery after 1 year of follow-up was 95%.
The 1-year outcomes were similar for patients assigned to early surgery and those assigned to conservative treatment with eventual surgery if needed, but the rates of pain relief and of perceived recovery were faster for those assigned to early surgery. (Current Controlled Trials number, ISRCTN26872154 controlled-trials.com.).
Objectives To evaluate the effects of early lumbar disc surgery compared with prolonged conservative care for patients with sciatica over two years of follow-up.Design Randomised controlled ...trial.Setting Nine Dutch hospitals.Participants 283 patients with 6-12 weeks of sciatica.Interventions Early surgery or an intended six months of continued conservative treatment, with delayed surgery if needed.Main outcome measures Scores from Roland disability questionnaire for sciatica, visual analogue scale for leg pain, and Likert self rating scale of global perceived recovery.Results Of the 141 patients assigned to undergo early surgery, 125 (89%) underwent microdiscectomy. Of the 142 patients assigned to conservative treatment, 62 (44%) eventually required surgery, seven doing so in the second year of follow-up. There was no significant overall difference between treatment arms in disability scores during the first two years (P=0.25). Improvement in leg pain was faster for patients randomised to early surgery, with a significant difference between “areas under the curves” over two years (P=0.05). This short term benefit of early surgery was no longer significant by six months and continued to narrow between six months and 24 months. Patient satisfaction decreased slightly between one and two years for both groups. At two years 20% of all patients reported an unsatisfactory outcome.Conclusions Early surgery achieved more rapid relief of sciatica than conservative care, but outcomes were similar by one year and these did not change during the second year.Trial Registry ISRCT No 26872154.
Cyclooxygenase (COX) catalyzes the conversion of arachidonic acid to prostaglandin H2. The inducible isoform, COX-2, promotes colorectal tumorigenesis, and nonsteroidal anti-inflammatory drugs ...(NSAIDs) that selectively inhibit this isoform are chemopreventive in murine models of intestinal tumorigenesis. To establish a mechanism for their chemopreventive properties, we examined the effect of a COX-2-selective inhibitor, NS-398, on two colorectal carcinoma cell lines: HT29, which was found to express COX-2 protein constitutively; and S/KS, which did not express detectable levels of COX-2 protein. NS-398 had a dose-dependent antiproliferative effect on each cell line (IC50, 82.0 +/- 10.1 microM for HT29 and 78.6 +/- 11.1 microM for S/KS), and this was due to the induction of apoptosis. Cell cycle parameters were unaffected by NS-398 treatment. The ability of NS-398 to induce apoptosis provides a potential mechanism by which COX-2-selective inhibitors are chemopreventive and also indicates their potential as chemotherapeutic agents for colorectal cancer. That this effect was independent of COX-2 protein expression suggests that COX-2-selective NSAIDs may, like nonselective NSAIDs, be antineoplastic in the absence of COX-2.
The reference surgical procedure for the treatment of lumbar disc herniation is open microdiscectomy. Minimal invasive discectomy with tubular retractors is hypothesised to cause less tissue damage ...and result in lower blood loss, less postoperative pain and faster recovery. We previously reported our 1 and 2-year results, and found no better outcomes of tubular discectomy compared with open microdiscectomy. Until now, no studies on tubular discectomy have reported results with more than 2 years of follow-up. Studies with long-term follow-up are required to determine if clinical outcomes are sustained and to assess specific long-term outcomes such as reoperation rate and iatrogenic low back pain due to impaired spinal integrity. The aim of this study is to evaluate the 5-year results of tubular discectomy compared with conventional microdiscectomy.
The study was designed as a double-blind randomised controlled trial. 325 patients with a symptomatic lumbar disc herniation were randomly allocated to tubular discectomy (166 patients) or conventional microdiscectomy (159 patients). Repeated standardised follow-up measurements were performed at 2, 4, 6, 8, 12, 26, 38, 52, 78, 104, 156, 208 and 260 weeks after randomisation. Main outcomes are the Roland-Morris Disability Questionnaire for Sciatica (RDQ), Visual Analogue Scale for leg pain and low back pain, self-perceived recovery and reoperation incidence.
There was no clinically significant difference between tubular discectomy and conventional microdiscectomy regarding the main clinical outcomes at any time point during the 5 years of follow-up. RDQ scores at 5 years were 4.3 (95% CI 3.3 to 5.2) in the tubular discectomy group and 3.4 (95% CI 2.4 to 4.5) in the conventional microdiscectomy group. The mean difference of 0.9 (95% CI -0.6 to 2.2) was not significant. Mean differences for leg pain and back pain were 0.2 (95% CI -5.5 to 6.0) and 0.4 (95% CI -5.9 to 6.7), respectively. 77% of patients allocated to conventional discectomy reported complete or near-complete recovery of symptoms compared with 74% of patients allocated to tubular discectomy (p=0.79). The reoperation rate was 18% in the tubular discectomy group and 13% in the conventional discectomy group (p=0.29).
Long-term functional and clinical outcome did not differ between patients allocated to tubular discectomy and conventional microdiscectomy. Primary and secondary outcome measures did not support the hypothesised advantages of tubular discectomy over conventional microdiscectomy.
ISRCTN51857546.
The frequency dependent beampatterns of an active sonar projector filters the acoustic signal that is transmitted into the medium, also known as the transmit waveform. This filtering encodes ...information about the target's bearing relative to the main response axis. For any given projector and transmit waveform spectrum, there exists an optimal angle of operation which maximizes the Fisher Information (FI) of the target bearing estimate. Previous investigations into this phenomena show that for narrowband (i.e, high Q) Linear Frequency Modulated (LFM) waveforms, the angle of maximum FI is solely determined by its center frequency f c . Steering the region of maximum bearing estimation precision is then achieved by appropriate selection of the LFM waveform's center frequency f c . This fine bearing estimation is accomplished without steering the projector's main response axis. In addition to LFM waveforms, a wide variety of other active sonar waveform types exist that possess distinct spectral characteristics. These other waveforms possess different Ambiguity Function (AF) shapes from the LFM and are typically utilized to suite the range-Doppler resolution requirements of the active sonar system. This paper investigates the transmit waveform impact on off-axis bearing estimation performance and the spectral filtering impact on the waveform's AF shape. High Q waveforms perform similarly to the LFM for off-axis bearing estimation while the transducer's spectral filtering perturbs the waveform's AF shape.
OBJECTIVE: To report outcome of horses with femorotibial lesions (meniscal, cartilage or ligamentous) treated with surgery and intra‐articular administration of autologous bone marrow derived ...mesenchymal stem cells (BMSCs). STUDY DESIGN: Prospective case series. ANIMALS: Horses (n = 33). METHODS: Inclusion criteria included horses that had lameness localized to the stifle by diagnostic anesthesia, exploratory stifle arthroscopy and subsequent intra‐articular administration of autologous BMSCs. Case details and follow‐up were gathered from medical records, owner, trainer or veterinarian. Outcome was defined as returned to previous level of work, returned to work, or failed to return to work. RESULTS: Follow‐up (mean, 24 months) was obtained; 43% of horses returned to previous level of work, 33% returned to work, and 24% failed to return to work. In horses with meniscal damage (n = 24) a higher percentage in the current study (75%) returned to some level of work compared to those in previous reports (60–63%) that were treated with arthroscopy alone, which resulted in a statistically significant difference between studies (P = .038). Joint flare post injection was reported in 3 horses (9.0%); however, no long‐term effects were noted. CONCLUSIONS: Intra‐articular administration of BMSC postoperatively for stifle lesions appeared to be safe, with morbidity being similar to that of other biologic agents. Improvement in ability to return to work may be realized with BMSC treatment compared to surgery alone in horses with stifle injury.
PDF
