Quality of life after postmastectomy radiotherapy in patients with intermediate-risk breast cancer (SUPREMO): 2-year follow-up results of a randomised controlled trial.

BACKGROUND: Postmastectomy radiotherapy in patients with four or more positive axillary nodes reduces breast cancer mortality, but its role in patients with one to three involved nodes is controversial. We assessed the effects of postmastectomy radiotherapy on quality of life (QOL) in women with intermediate-risk breast cancer. METHODS: SUPREMO is an open-label, international, parallel-group, randomised, controlled trial. Women aged 18 years or older with intermediate-risk breast cancer (defined as pT1-2N1; pT3N0; or pT2N0 if also grade III or with lymphovascular invasion) who had undergone mastectomy and, if node positive, axillary surgery, were randomly assigned (1:1) to receive chest wall radiotherapy (50 Gy in 25 fractions or a radiobiologically equivalent dose of 45 Gy in 20 fractions or 40 Gy in 15 fractions) or no radiotherapy. Randomisation was done with permuted blocks of varying block length, and stratified by centre, without masking of patients or investigators. The primary endpoint is 10-year overall survival. Here, we present 2-year results of QOL (a prespecified secondary endpoint). The QOL substudy, open to all UK patients, consists of questionnaires (European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23, Body Image Scale, Hospital Anxiety and Depression Scale [HADS], and EQ-5D-3L) completed before randomisation, and at 1, 2, 5, and 10 years. The prespecified primary outcomes within this QOL substudy were global QOL, fatigue, physical function, chest wall symptoms, shoulder and arm symptoms, body image, and anxiety and depression. Data were analysed by intention to treat, using repeated mixed-effects methods. This trial is registered with the ISRCTN registry, number ISRCTN61145589. FINDINGS: Between Aug 4, 2006, and April 29, 2013, 1688 patients were enrolled internationally and randomly assigned to receive chest wall radiotherapy (n=853) or not (n=835). 989 (79%) of 1258 patients from 111 UK centres consented to participate in the QOL substudy (487 in the radiotherapy group and 502 in the no radiotherapy group), of whom 947 (96%) returned the baseline questionnaires and were included in the analysis (radiotherapy, n=471; no radiotherapy, n=476). At up to 2 years, chest wall symptoms were worse in the radiotherapy group than in the no radiotherapy group (mean score 14·1 [SD 15·8] in the radiotherapy group vs 11·6 [14·6] in the no radiotherapy group; effect estimate 2·17, 95% CI 0·40-3·94; p=0·016); however, there was an improvement in both groups between years 1 and 2 (visit effect -1·34, 95% CI -2·36 to -0·31; p=0·010). No differences were seen between treatment groups in arm and shoulder symptoms, body image, fatigue, overall QOL, physical function, or anxiety or depression scores. INTERPRETATION: Postmastectomy radiotherapy led to more local (chest wall) symptoms up to 2 years postrandomisation compared with no radiotherapy, but the difference between groups was small. These data will inform shared decision making while we await survival (trial primary endpoint) results. FUNDING: Medical Research Council, European Organisation for Research and Treatment of Cancer, Cancer Australia, Dutch Cancer Society, Trustees of Hong Kong and Shanghai Banking Corporation.

Investigating impacts of the mycothiazole chemotype as a chemical probe for the study of mitochondrial function and aging.

Small molecule inhibitors of the mitochondrial electron transport chain (ETC) hold significant promise to provide valuable insights to the field of mitochondrial research and aging biology. In this study, we investigated two molecules: mycothiazole (MTZ) - from the marine sponge C. mycofijiensis and its more stable semisynthetic analog 8-O-acetylmycothiazole (8-OAc) as potent and selective chemical probes based on their high efficiency to inhibit ETC complex I function. Similar to rotenone (Rote), MTZ, a newly employed ETC complex I inhibitor, exhibited higher cytotoxicity against cancer cell lines compared to certain non-cancer cell lines. Interestingly, 8-OAc demonstrated greater selectivity for cancer cells when compared to both MTZ and Rote, which has promising potential for anticancer therapeutic development. Furthermore, in vivo experiments with these small molecules utilizing a C. elegans model demonstrate their unexplored potential to investigate aging studies. We observed that both molecules have the ability to induce a mitochondria-specific unfolded protein response (UPRMT) pathway, that extends lifespan of worms when applied in their adult stage. We also found that these two molecules employ different pathways to extend lifespan in worms. Whereas MTZ utilizes the transcription factors ATFS-1 and HSF1, which are involved in the UPRMT and heat shock response (HSR) pathways respectively, 8-OAc only required HSF1 and not ATFS-1 to mediate its effects. This observation underscores the value of applying stable, potent, and selective next generation chemical probes to elucidate an important insight into the functional roles of various protein subunits of ETC complexes and their regulatory mechanisms associated with aging.

Investigating impacts of marine sponge derived mycothiazole and its acetylated derivative on mitochondrial function and aging.

Small molecule inhibitors of the mitochondrial electron transport chain (ETC) hold significant promise to provide valuable insights to the field of mitochondrial research and aging biology. In this study, we investigated two molecules: mycothiazole (MTZ) - from the marine sponge C. mycofijiensis and its more stable semisynthetic analog 8-O-acetylmycothiazole (8-OAc) as potent and selective chemical probes based on their high efficiency to inhibit ETC complex I function. Similar to rotenone (Rote), a widely used ETC complex I inhibitor, these two molecules showed cytotoxicity to cancer cells but strikingly demonstrate a lack of toxicity to non-cancer cells, a highly beneficial feature in the development of anti-cancer therapeutics. Furthermore, in vivo experiments with these small molecules utilizing C.elegans model demonstrate their unexplored potential to investigate aging studies. We observed that both molecules have the ability to induce a mitochondria-specific unfolded protein response (UPRMT) pathway, that extends lifespan of worms when applied in their adult stage. Interestingly, we also found that these two molecules employ different pathways to extend lifespan in worms. Whereas MTZ utilize the transcription factors ATFS-1 and HSF-1, which are involved in the UPRMT and heat shock response (HSR) pathways respectively, 8-OAc only required HSF-1 and not ATFS-1 to mediate its effects. This observation underscores the value of applying stable, potent, and selective next generation chemical probes to elucidate an important insight into the functional roles of various protein subunits of ETC complexes and their regulatory mechanisms associated with aging.

Role of CYP2E1 in ketone-stimulated insulin release in pancreatic B-cells.

The role of CYP2E1 in ketone-stimulated insulin release was investigated using isolated pancreatic islets of Langerhans and two mammalian insulin secreting pancreatic beta-cell lines engineered to stably express human CYP2E1 (designated BRIN BD11h2E1 and INS-1h2E1). Isolated rat pancreatic islets were shown to express the CYP2E1 isoform which was inducible by pretreatment of animals with acetone. The cDNA encoded CYP2E1 was expressed and inducible in the engineered cells as shown by Western blotting. The transfected protein was enzymatically active in the heterologous cells as determined by p-nitrophenol hydroxylation rates (0.176 +/- 0.08 vs. 0.341 +/- 0.08 nmol/min/mg microsomal protein in BRIN BD11 control cells and BRIN BD11h2E1 cells respectively, P < 0.001; 0.204 +/- 0.03 vs. 0.633 +/- 0.102 nmol/min/mg microsomal protein in INS-1 and INS-1h2E1, respectively, P < 0.001). Cultivation of CYP2E1 expressing BRIN BD11h2E1 and INS-1h2E1 cells in 40 mM ethanol increased the rate of p-nitrophenol hydroxylation (0.968 +/- 0.09 nmol/min/mg microsomal protein, P < 0.001 and 0.846 +/- 0.103 nmol/min/mg microsomal protein, P < 0.001, respectively) providing further evidence that the heterologous protein is inducible. Cultivation of control cells with ethanol had no observable effect (0.186 +/- 0.05 and 0.195 +/- 0.03 in BRIN BD11 and INS-1, respectively). These cell lines also express NADPH-cytochrome P450 reductase protein which was enzymatically active (0.632 +/- 0.023 in parental BRIN BD11 vs. 0.657 +/- 0.066 without ethanol and 0.824 +/- 0.014 nmol/min/mg microsomal protein with ethanol in BRIN BD11h2E1, P < 0.05; and 1.568 +/- 0.118 in parental INS-1 vs. 1.607 +/- 0.093 without ethanol and 1.805 +/- 0.066 nmol/min/mg microsomal protein with ethanol in INS-1h2E1, P < 0.05) thereby providing a functional cytochrome P450 system. The insulin secretory response of control cell lines and islets was similar to cell lines and islets which had been chemically pretreated, to induce CYP2E1 expression, in response to known nutrient secretagogues. However, insulin output was significantly higher in pretreated islets (1.3-fold, P < 0.05) and CYP2E1 expressing cell lines (BRIN BD11h2E1 2.3-fold, P < 0.001; INS1-1h2E1 1.6-fold, P < 0.001) when stimulated with the ketone 3-hydroxybutyrate than control islets and parental cell lines respectively. Similar acute exposure to acetoacetate enhanced insulin secretion by 1.3-fold (P < 0.05) in pretreated islets, 2.6-fold (P < 0.001) in ethanol pretreated BRIN BD11h2E1 and 1.4-fold (P < 0.001) in ethanol pretreated INS-1h2E1 cells compared to the respective control islets or ethanol pretreated control parental cells. Therefore, these studies highlight a possible role for CYP2E1 in pancreatic cell dysfunction.

Acute wound closure.

As an A&E nurse, I care for clients requiring acute wound closure and I enjoy the challenge it presents. This article reviewed the rationale of wound closure. It enabled me to revise the principles and to discover new techniques.