Lack of consensus on post-operative radiotherapy (PORT) fields used in non-small cell lung cancer (NSCLC)

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Background: Survival in patients with a completely resected stage III-N2 NSCLC may be improved by PORT. LungART is a phase III trial for patients with resected N2 disease who will be randomized to between PORT and no PORT, irrespective of the use of chemotherapy. LungArt target volumes are based upon the post-surgical findings in each patient, and on the surgical literature. A ‘dummy run’ was performed to study PORT volumes used internationally and to evaluate the LungART protocol. Methods: A CD-rom based contouring program containing the planning CT scans of 2 patients (post-lobectomy and pneumonectomy, respectively) were mailed to 17 thoracic radiation oncologists from 4 continents. Relevant clinical, radiological and pathological reports were provided in order to allow clinicans to contour their ‘routine’ clinical target volumes (CTV). Contours were saved onto a CD-rom and mailed to the study center. The LungART protocol was then provided and ‘protocol’ CTVs were generated. Contours of each case were transferred to a template CT dataset of that patient, and nodal CTVs were jointly generated by two clinicians using published definitions. An optimised treatment plan was generated for all CTV's. Results: For each case, a total of 10 routine CTVs were received. Both routine and protocol CTVs were provided for each case by 6 clinicians. The routine CTVs varied up to 3-fold between clinicians and this was significantly decreased by use of the protocol (F test, p=0.00003 and p=0.00002 for cases 1 and 2, respectively). Coverage of nodal stations 2R and 4R improved when CTVs were defined using the protocol. Risks of lung toxicity, as defined by the lung volumes treated to 20 Gy and 5 Gy, varied between the smallest and second largest routine CTVs. For the post-lobectomy case, the V20 (range) was 11.8–19.3% and a V5 of 33.8–57.9%. The corresponding V20 and V5 values were 1.5–2.1% and 31.6–39.7% for the post-pneumonectomy case. Both cardiac volumes receiving 45 Gy and spinal doses were similar for both CTVs. Conclusions: The variations in PORT volumes generated by experts led to important differences in the risk of radiation-induced lung toxicity. Standardized target definitions are needed in order to optimize the survival benefits from PORT, and the LungArt protocol may serve this purpose.

No significant financial relationships to disclose.

Clinical outcome in patients with intramedullary spinal cord metastases from lung cancer

Intramedullary spinal cord metastases (ISCM) are uncommon and present with rapidly progressing neurological deficits. The objective of this study was to determine the rate, duration of neurological response and survival after radiation therapy. We have retrospectively reviewed the clinical outcome of six cases with a diagnosis of ISCM from primary lung cancer, non-small cell (NSCLC) (n=3) and small cell (SCLC) (n=3). Total radiation dose ranged from 27 Gy/5 fr to 40 Gy/20 fr. Ambulation was preserved in 3 patients and partially recovered in one. Five out of the six patients (83%) showed improvement in neurological signs/symptoms with a mean duration of 17.2 days (max: 40 days; min: 6 days). Median survival time was 5 months (confidence interval (CI) 95%: 0-12) for NSCLC and 5 months (CI 95%: 4-6) for SCLC. Although radiation response rate is high, the interval free of neurological progression is very short. A therapeutic approach should be considered for each individual.

[Radiation therapy in simultaneous choroidal and brain metastases]

Choroidal metastases from lung cancer can be the initial clinical manifestation of metastasic disease, although they generally coexist with at least two more metastasic sites. The most common symptom is decreased vision, however 20% of brain metastases can present with visual alterations. A differential diagnosis within brain metastases and/or choroidal is necessary. We present the case of a patient with lung cancer and decreased vision who was diagnosed as simultaneous choroidal and brain metastases. Radiation therapy (20Gy/5fractions) significantly improves decreased vision. This case shows that, although life expectancy of patients with metastasic lung cancer is short, an adequate diagnosis and treatment, can improve the quality of life of those patients.

Factors related to variability in long-term oxygen therapy prevalence

OBJECTIVE

To analyse the variability of long term oxygen therapy (LTOT) prevalence according to several organisational and population factors.

METHODS

Prospective multicentre survey in 29 public hospitals (population 6,796,964) recording data on the organisational structure of the participating centres and factors related to LTOT prevalence. Official figures were also obtained from local health authorities on the prevalence and cost of LTOT.

RESULTS

The overall prevalence of LTOT was 184 per 100000 population (range 71-473). There was a specific unit or staff member for LTOT supervision in 17 (58.6%) centres, giving a lower prevalence (169 vs. 237/ 100000; P = 0.03). The altitude of the participating centres (median 92 m, mean 275 m; range 4-848 m) was found to influence LTOT prevalence (r = 0.73; P = 0.005). In the linear regression analysis, the coefficient of determination for altitude was 0.504. Other factors, such as percentage of population aged over 65 years, the attitude of prescribers towards patients with low adherence, current smokers or those with a PaO2 = 61 mmHg, were not related to LTOT prevalence.

CONCLUSIONS

Altitude and the existence of a specific unit or staff member for LTOT supervision significantly influence LTOT prevalence.

Integrating concurrent navelbine and cisplatin to hyperfractionated radiotherapy in locally advanced non-small cell lung cancer patients treated with induction and consolidation chemotherapy: feasibility and activity results

OBJECTIVES

The purpose of this study was to determine the effectiveness and toxicity of a new combination schedule based on concurrent navelbine, cisplatin and hyperfractionated radiotherapy in patients with locally advanced NSCLC treated with platinum and gemcitabine induction and consolidation chemotherapy.

MATERIALS AND METHODS

The 37 patients with pathological confirmed advanced NSCLC (non-surgical stages IIIA and IIIB) were included in the study. All of them were assessable for survival and 32 for response. The treatment schedule consisted of cisplatin (100 mg/m2) or carboplatin (400 mg/m2) on day 1 with gemcitabine (1000 mg/m2) on days 1, 8 and 15. Treatment was given every 28 days for two courses, followed by concurrent administration of accelerated modified hyperfractionated radiotherapy, with concomitant boost, with a total dose of 61.64 Gy administered for 5 weeks, with cisplatin and navelbine, for two courses, finally followed by two courses of the same initial chemotherapy.

RESULTS

Four patients achieved complete response (12.5%) and 14 (44%) partial response, for an overall objective response rate of 56.5%. After a minimum follow-up duration of 35.5 months, median progression free survival was 12.2 months. The median survival was 15.4 months with actuarial 1-, 2- and 3-year survival of 67, 21 and 15%, respectively. The main toxicity was hematological. There was esophagitis (grades III and IV) in 30% of the patients and there were two treatment-related deaths.

CONCLUSION

Combined treatment with concurrent radiotherapy and chemotherapy in non-surgical NSCLC is an acceptable treatment modality. However, the toxicity was not negligible.

Comparative bioavailability of two oral formulations of bromazepam in healthy volunteers

The aim of this study was to assess the pharmacokinetic profile of two bromazepam (CAS 1812-30-2) formulations in 24 healthy volunteers. An open, randomised clinical trial designed as two-period crossover with 14-day washout between doses was employed. Plasma samples for assessments of their bromazepam concentration by HPLC-UV were obtained over 96 h after administration. No adverse effect was reported for any of the formulations administered. The following pharmacokinetics parameters were calculated: AUC(0-96 h), AUCinf, Cmax, Tmax, Ke and T1/2. The 90% confidence intervals (CI) for the mean test/reference individual ratios were 81-109 for AUC and 84-116 for Cmax. Since the 90% CI for both, AUC and Cmax ratios were within the 80-125% interval proposed by the Food and Drug Administration, it is concluded that the new bromazepam slow-release formulation is therapeutic equivalent to the conventional formulation for both, the extent and the rate of absorption after single dose administration in healthy volunteers.

Opposing functions of ATF2 and Fos-like transcription factors in c-Jun-mediated myogenin expression and terminal differentiation of avian myoblasts

With the aim to identify the oncoprotein partners implicated in the c-Jun myogenic influence, we carried out stable transfection experiments of c-Jun and/or ATF2, Fra2, c-Fos overexpression in avian myoblasts. Before induction of differentiation, c-Jun repressed myoblast withdrawal from the cell cycle, as did a TPA treatment. However, after serum removal, unlike TPA, c-Jun significantly stimulated myoblast differentiation. In search for specific partners involved in this dual influence, we found that a reduction in the amounts of c-Fos and Fra2 and an increase in c-Jun proteins occurred at cell confluence, a situation likely to favor cooperation between c-Jun and ATF2 during terminal differentiation. Whereas c-Fos and Fra2 cooperated with c-Jun to abrogate myoblast withdrawal from the cell cycle and terminal differentiation, ATF2 co-expression potentiated the positive myogenic c-Jun influence. In addition, myogenin expression was a positive target of this cooperation and this regulation occurred through a stimulation of myogenin promoter activity: (1) whereas c-Fos or Fra2 co-expression abrogated c-Jun stimulatory activity on this promoter, ATF2 co-expression potentiated this influence; (2) using a dominant negative ATF2 mutant, we established that c-Jun transcriptional activity required functionality of endogenous ATF2. These data suggest that through this dual myogenic influence due to cooperations with different partners, c-Jun is involved in the control of duration of myoblast proliferation and thereafter of fusion efficiency.

The triiodothyronine nuclear receptor c-ErbAalpha1 inhibits avian MyoD transcriptional activity in myoblasts

Thyroid hormone stimulates myoblast differentiation, through an inhibition of AP-1 activity occurring at the onset of differentiation. In this study we found that the T3 nuclear receptor c-ErbAalpha1 (T3Ralpha1) is involved in a mechanism preserving the duration of myoblast proliferation. Independently of the hormone presence, T3Ralpha1 represses avian MyoD transcriptional activity. Using several mutants of T3Ralpha1, we found that the hinge region plays a crucial role in the inhibition of MyoD activity. In particular, mutations of two small basic sequences included in alpha helices abrogate the T3Ralpha1/MyoD functional interaction. Similarly, the T3 receptor also represses myogenin transcriptional activity. Therefore, despite stimulating avian myoblast differentiation by a T3-dependent pathway not involving myogenic factors, T3Ralpha1 contributes to maintain an optimal myoblast proliferation period by inhibiting MyoD and myogenin activity.

Identification of functional domains involved in BTG1 cell localization

We have previously shown that BTG1 stimulates myoblast differentiation. In addition, this protein displays a major nuclear localization in confluent myoblasts, decreasing during the early steps of differentiation, and is essentially detected in the cytoplasm of mature myotubes. To identify the domains involved in the cellular trafficking of BTG1, we observed the localization of several BTG1 sequences fused to betaGalactosidase. The highly conserved B box among all members of the BTG family induces a significant nuclear localization of the betaGal moiety, enhanced by presence of the BTG1 carboxy-terminal sequence. In addition, a functional Nuclear Export Signal (NES) overlaps the B box. Moreover, presence of the first 43 NH(2)-terminal amino acids reduced the nuclear localization of each chimeric protein tested. Last, the BTG1 amino-terminal domain bears an LxxLL motif favouring nuclear accumulation, and another region encompassing the A box inhibiting nuclear localization. In contrast to a BTG1 mutant exclusively localized in the cytoplasm, transient expression of a mutant displaying a nuclear localization enhanced myoblasts withdrawal from the cell cycle and terminal differentiation, thus mimicking the myogenic influence of BTG1. In conclusion, several regions of BTG1 are implicated in its cellular localization, and BTG1 myogenic activity is induced at the nuclear level.

Thyroid hormone action in mitochondria

Triiodothyronine (T3) is considered a major regulator of mitochondrial activity. In this review, we show evidence of the existence of a direct T3 mitochondrial pathway, and try to clarify the respective importance of the nuclear and mitochondrial pathways for organelle activity. Numerous studies have reported short-term and delayed T3 stimulation of mitochondrial oxygen consumption. Convincing data indicate that an early influence occurs through an extra-nuclear mechanism insensitive to inhibitors of protein synthesis. Although it has been shown that diiodothyronines could actually be T3 mediators of this short-term influence, the detection of specific T3-binding sites, probably corresponding to a 28 kDa c-Erb Aalpha1 protein of the inner membrane, also supports a direct T3 influence. The more delayed influence of thyroid hormone upon mitochondrial respiration probably results from mechanisms elicited at the nuclear level, including changes in phospholipid turnover and stimulation of uncoupling protein expression, leading to an increased inner membrane proton leak. However, the involvement of a direct mitochondrial T3 pathway leading to a rapid stimulation of mitochondrial protein synthesis has to be considered. Both pathways are obviously involved in the T3 stimulation of mitochondrial genome transcription. First, a 43 kDa c-Erb Aalpha1 protein located in the mitochondrial matrix (p43), acting as a potent T3-dependent transcription factor of the mitochondrial genome, induces early stimulation of organelle transcription. In addition, T3 increases mitochondrial TFA expression, a mitochondrial transcription factor encoded by a nuclear gene. Similarly, the stimulation of mitochondriogenesis by thyroid hormone probably involves both pathways. In particular, the c-erb Aalpha gene simultaneously encodes a nuclear and a mitochondrial T3 receptor (p43), thus ensuring coordination of the expression of the mitochondrial genome and of nuclear genes encoding mitochondrial proteins. Recent studies concerning the physiological importance of the direct mitochondrial T3 pathway involving p43 led to the conclusion that it is not only involved in the regulation of fuel metabolism, but also in the regulation of cell differentiation. As the processes leading to or resulting from differentiation are energy-consuming, p43 coordination of metabolism and differentiation could be of significant importance in the regulation of development.

New molecular aspects of regulation of mitochondrial activity by fenofibrate and fasting

Fenofibrate and fasting are known to regulate several genes involved in lipid metabolism in a similar way. In this study measuring several mitochondrial enzyme activities, we demonstrate that, in contrast to citrate synthase and complex II, cytochrome c oxidase (COX) is a specific target of these two treatments. In mouse liver organelles, Western blot experiments indicated that mitochondrial levels of p43, a mitochondrial T3 receptor, and mitochondrial peroxisome proliferator activated receptor (mt-PPAR), previously described as a dimeric partner of p43 in the organelle, are increased by both fenofibrate and fasting. In addition, in PPAR alpha-deficient mice, this influence was abolished for mt-PPAR but not for p43, whereas the increase in COX activity was not altered. These data indicate that: (1) PPAR alpha is involved in specific regulation of mt-PPAR expression by both treatments; (2) fenofibrate and fasting regulate the mitochondrial levels of p43 and thus affect the efficiency of the direct T3 mitochondrial pathway.

A 45 kDa protein related to PPARgamma2, induced by peroxisome proliferators, is located in the mitochondrial matrix

Besides their involvement in the control of nuclear gene expression by activating several peroxisome proliferator-activated receptors (PPARs), peroxisome proliferators influence mitochondrial activity. By analogy with the previous characterization of a mitochondrial T3 receptor (p43), we searched for the presence of a peroxisome proliferator target in the organelle. Using several antisera raised against different domains of PPARs, we demonstrated by Western blotting, immunoprecipitation and electron microscopy experiments, that a 45 kDa protein related to PPARgamma2 (mt-PPAR) is located in the matrix of rat liver mitochondria. In addition, we found that the amounts of mt-PPAR are increased by clofibrate treatment. Moreover, in EMSA experiments mt-PPAR bound to a DR2 sequence located in the mitochondrial D-loop, by forming a complex with p43. Last, studies of tissue-specific expression indicated that mt-PPAR is detected in mitochondria of all tissues tested except the brain in amounts positively related to p43 abundance. Besides their involvement in the control of nuclear gene expression by activating several peroxisome proliferator-activated receptors (PPARs), peroxisome proliferators influence mitochondrial activity. By analogy with the previous characterization of a mitochondrial T3 receptor (p43), we searched for the presence of a peroxisome proliferator target in the organelle. Using several antisera raised against different domains of PPARs, we demonstrated by Western blotting, immunoprecipitation and electron microscopy experiments, that a 45 kDa protein related to PPARgamma2 (mt-PPAR) is located in the matrix of rat liver mitochondria. In addition, we found that the amounts of mt-PPAR are increased by clofibrate treatment. Moreover, in EMSA experiments mt-PPAR bound to a DR2 sequence located in the mitochondrial D-loop, by forming a complex with p43. Last, studies of tissue-specific expression indicated that mt-PPAR is detected in mitochondria of all tissues tested except the brain in amounts positively related to p43 abundance.

Acoustic analysis after radiotherapy in T1 vocal cord carcinoma: a new approach to the analysis of voice quality

PURPOSE

The study of acoustic voice parameters (fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio) in extended vowel production, oral reading of a standard paragraph, spontaneous speech and a song in irradiated patients for Tis-T1 vocal cord carcinoma.

METHODS AND MATERIALS

Eighteen male patients irradiated for Tis-T1 vocal cord carcinoma and a control group of 31 nonirradiated subjects of the same age were included in a study of acoustic voice analysis. The control group had been rigorously selected for voice quality and the irradiated group had previous history of smoking in two-thirds of the cases and a vocal cord biopsy. Radiotherapy patients were treated with a 6MV Linac receiving a total dose of 66 Gy, 2 Gy/day, with median treatment areas of 28 cm(2). Acoustic voice analysis was performed 1 year after radiotherapy, the voice of patients in extended vowel production, oral reading of a standard paragraph, spontaneous speech, and in a song was tape registered and analyzed by a Kay Elemetric's Computerized Speech Lab (model CSL# 4300). Fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio were obtained in each case. Mann Whitney analysis was used for statistical tests.

RESULTS

The irradiated group presented higher values of fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio. Mann-Whitney analysis showed significant differences for fundamental frequency and jitter in vowel production, oral reading, spontaneous speech, and song. Shimmer only showed differences in vowel production and harmonics-to-noise ratio in oral reading and song.

CONCLUSIONS

In our study only fundamental frequency and jitter showed significant increased values to the control group in all the acoustic situations. Sustained vowel production showed the worst values of the acoustic parameters in comparison with the other acoustic situations. This study seems to suggest that more work should be done in this field.

Mitochondrial activity is involved in the regulation of myoblast differentiation through myogenin expression and activity of myogenic factors

To characterize the regulatory pathways involved in the inhibition of cell differentiation induced by the impairment of mitochondrial activity, we investigated the relationships occurring between organelle activity and myogenesis using an avian myoblast cell line (QM7). The inhibition of mitochondrial translation by chloramphenicol led to a potent block of myoblast differentiation. Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone and oligomycin, which affect the organelle at different levels, exerted a similar influence. In addition, we provided evidence that this phenomenon was not the result of an alteration in cell viability. Conversely, overexpression of the mitochondrial T3 receptor (p43) stimulated organelle activity and strongly potentiated myoblast differentiation. The involvement of mitochondrial activity in an actual regulation of myogenesis is further supported by results demonstrating that the muscle regulatory gene myogenin, in contrast to CMD1 (chicken MyoD) and myf5, is a specific transcriptional target of mitochondrial activity. Whereas myogenin mRNA and protein levels were down-regulated by chloramphenicol treatment, they were up-regulated by p43 overexpression, in a positive relationship with the expression level of the transgene. We also found that myogenin or CMD1 overexpression in chloramphenicol-treated myoblasts did not restore differentiation, thus indicating that an alteration in mitochondrial activity interferes with the ability of myogenic factors to induce terminal differentiation.

A variant form of the nuclear triiodothyronine receptor c-ErbAalpha1 plays a direct role in regulation of mitochondrial RNA synthesis

In earlier research, we identified a 43-kDa c-ErbAalpha1 protein (p43) in the mitochondrial matrix of rat liver. In the present work, binding experiments indicate that p43 displays an affinity for triiodothyronine (T3) similar to that of the T3 nuclear receptor. Using in organello import experiments, we found that p43 is targeted to the organelle by an unusual process similar to that previously reported for MTF1, a yeast mitochondrial transcription factor. DNA-binding experiments demonstrated that p43 specifically binds to four mitochondrial DNA sequences with a high similarity to nuclear T3 response elements (mt-T3REs). Using in organello transcription experiments, we observed that p43 increases the levels of both precursor and mature mitochondrial transcripts and the ratio of mRNA to rRNA in a T3-dependent manner. These events lead to stimulation of mitochondrial protein synthesis. In transient-transfection assays with reporter genes driven by the mitochondrial D loop or two mt-T3REs located in the D loop, p43 stimulated reporter gene activity only in the presence of T3. All these effects were abolished by deletion of the DNA-binding domain of p43. Finally, p43 overexpression in QM7 cells increased the levels of mitochondrial mRNAs, thus indicating that the in organello influence of p43 was physiologically relevant. These data reveal a novel hormonal pathway functioning within the mitochondrion, involving a truncated form of a nuclear receptor acting as a potent mitochondrial T3-dependent transcription factor.