Identification of the substrate recognition region in the Δ6-fatty acid and Δ8-sphingolipid desaturase by fusion mutagenesis.

Δ8-sphingolipid desaturase and Δ6-fatty acid desaturase share high protein sequence identity. Thus, it has been hypothesized that Δ6-fatty acid desaturase is derived from Δ8-sphingolipid desaturase; however, there is no direct proof. The substrate recognition regions of Δ6-fatty acid desaturase and Δ8-sphingolipid desaturase, which aid in understanding the evolution of these two enzymes, have not been reported. A blackcurrant Δ6-fatty acid desaturase and a Δ8-sphingolipid desaturase gene, RnD6C and RnD8A, respectively, share more than 80 % identity in their coding protein sequences. In this study, a set of fusion genes of RnD6C and RnD8A were constructed and expressed in yeast. The Δ6- and Δ8-desaturase activities of the fusion proteins were characterized. Our results indicated that (1) the exchange of the C-terminal 172 amino acid residues can lead to a significant decrease in both desaturase activities; (2) amino acid residues 114-174, 206-257, and 258-276 played important roles in Δ6-substrate recognition, and the last two regions were crucial for Δ8-substrate recognition; and (3) amino acid residues 114-276 of Δ6-fatty acid desaturase contained the substrate recognition site(s) responsible for discrimination between ceramide (a substrate of Δ8-sphingolipid desaturase) and acyl-PC (a substrate of Δ6-fatty acid desaturase). Substituting the amino acid residues 114-276 of RnD8A with those of RnD6C resulted in a gain of Δ6-desaturase activity in the fusion protein but a loss in Δ8-sphingolipid desaturase activity. In conclusion, several regions important for the substrate recognition of Δ8-sphingolipid desaturase and Δ6-fatty acid desaturase were identified, which provide clues in understanding the relationship between the structure and function in desaturases.

A new strategy to produce a defensin: stable production of mutated NP-1 in nitrate reductase-deficient Chlorella ellipsoidea.

Defensins are small cationic peptides that could be used as the potential substitute for antibiotics. However, there is no efficient method for producing defensins. In this study, we developed a new strategy to produce defensin in nitrate reductase (NR)-deficient C. ellipsoidea (nrm-4). We constructed a plant expression vector carrying mutated NP-1 gene (mNP-1), a mature α-defensin NP-1 gene from rabbit with an additional initiator codon in the 5'-terminus, in which the selection markers were NptII and NR genes. We transferred mNP-1 into nrm-4 using electroporation and obtained many transgenic lines with high efficiency under selection chemicals G418 and NaNO(3). The mNP-1 was characterized using N-terminal sequencing after being isolated from transgenic lines. Excitingly, mNP-1 was produced at high levels (approximately 11.42 mg/l) even after 15 generations of continuous fermentation. In addition, mNP-1 had strong activity against Escherichia coli at 5 µg/ml. This research developed a new method for producing defensins using genetic engineering.

The role of C-terminal amino acid residues of a Δ6-fatty acid desaturase from blackcurrant.

Δ6-fatty acid desaturase is an important enzyme in the catalytic synthesis of polyunsaturated fatty acids. Using domain swapping and a site-directed mutagenesis strategy, we found that the region of the C-terminal 67 amino acid residues of Δ6-fatty acid desaturase RnD6C from blackcurrant was essential for its catalytic activity and that seven different residues between RnD6C and RnD8A in that region were involved in the desaturase activity. Compared with RnD6C, the activity of the following mutations, V394A, K395I, F411L, S436P, VK3945AI and IS4356VP, was significantly decreased, whereas the activity of I417T was significantly increased. The amino acids N, T and Y in the last four residues also play a certain role in the desaturase activity.

Isolation and functional characterisation of the genes encoding Δ(8)-sphingolipid desaturase from Brassica rapa.

Δ(8)-Sphingolipid desaturase is the key enzyme that catalyses desaturation at the C8 position of the long-chain base of sphingolipids in higher plants. There have been no previous studies on the genes encoding Δ(8)-sphingolipid desaturases in Brassica rapa. In this study, four genes encoding Δ(8)-sphingolipid desaturases from B. rapa were isolated and characterised. Phylogenetic analyses indicated that these genes could be divided into two groups: BrD8A, BrD8C and BrD8D in group I, and BrD8B in group II. The two groups of genes diverged before the separation of Arabidopsis and Brassica. Though the four genes shared a high sequence similarity, and their coding desaturases all located in endoplasmic reticulum, they exhibited distinct expression patterns. Heterologous expression in Saccharomyces cerevisiae revealed that BrD8A/B/C/D were functionally diverse Δ(8)-sphingolipid desaturases that catalyse different ratios of the two products 8(Z)- and 8(E)-C18-phytosphingenine. The aluminium tolerance of transgenic yeasts expressing BrD8A/B/C/D was enhanced compared with that of control cells. Expression of BrD8A in Arabidopsis changed the ratio of 8(Z):8(E)-C18-phytosphingenine in transgenic plants. The information reported here provides new insights into the biochemical functional diversity and evolutionary relationship of Δ(8)-sphingolipid desaturase in plants and lays a foundation for further investigation of the mechanism of 8(Z)- and 8(E)-C18-phytosphingenine biosynthesis.

Enhanced tolerance to NaCl and LiCl stresses by over-expressing Caragana korshinskii sodium/proton exchanger 1 (CkNHX1) and the hydrophilic C terminus is required for the activity of CkNHX1 in Atsos3-1 mutant and yeast.

Sodium/proton exchangers (NHX antiporters) play important roles in plant responses to salt stress. Previous research showed that hydrophilic C-terminal region of Arabidopsis AtNHX1 negatively regulates the Na(+)/H(+) transporting activity. In this study, CkNHX1 were isolated from Caragana korshinskii, a pea shrub with high tolerance to salt, drought, and cold stresses. Transcripts of CkNHX1 were detected predominantly in roots, and were significantly induced by NaCl stress in stems. Transgenic yeast and Arabidopsisthalianasos3-1 (Atsos3-1) mutant over-expressing CkNHX1 and its hydrophilic C terminus-truncated derivative, CkNHX1-ΔC, were generated and subjected to NaCl and LiCl stresses. Expression of CkNHX1 significantly enhanced the resistance to NaCl and LiCl stresses in yeast and Atsos3-1 mutant. Whereas, compared with expression of CkNHX1, the expression of CkNHX1-ΔC had much less effect on NaCl tolerance in Atsos3-1 and LiCl tolerance in yeast and Atsos3-1. All together, these results suggest that the predominant expression of CkNHX1 in roots might contribute to keep C. korshinskii adapting to the high salt condition in this plant's living environment; CkNHX1 could recover the phenotype of Atsos3-1 mutant; and the hydrophilic C-terminal region of CkNHX1 should be required for Na(+)/H(+) and Li(+)/H(+) exchanging activity of CkNHX1.

[Therapeutic efficacy of three-dimensional conformal radiation therapy for patients with locally advanced non-small cell lung cancer].

OBJECTIVE: To compare the treatment results of three-dimensional conformal radiotherapy (3D-CRT) and conventional radiotherapy (2D) for patients with locally advanced non-small-cell lung cancer (NSCLC). METHODS: Five hundred and twenty seven patients with stage III NSCLC treated between Jan 2000 and Dec 2006 were included in this study. Among them, 253 cases were treated with 3D-CRT, and 274 with conventional radiotherapy. In the 3D group, 159 (62.8%) patients received chemoradiotherapy, 77 with total radiotherapy dose of > 60 Gy, 49 with 50 - 60 Gy. In the 2D group, 127 (46.4%) patients received chemoradiotherapy, 48 with total radiotherapy dose of > 60 Gy, 75 with 50 - 60 Gy. RESULTS: The 1-, 3-, 5-year overall survival rates (OS) and median survival time for patients treated with 3D-CRT were 73.3%, 26.1%, 14.4% and 20.1 months, respectively, and that of patients treated with 2D radiotherapy were 61.0%, 13.8%, 8.0% and 15.6 months, respectively (P = 0.002). The 1-, 3-, 5-year cause-specific survival rates (CSS) were 79.0%, 33.3%, and 20.8% for the 3D group and 65.1%, 16.7%, 11.2%, respectively, for the 2D group (P = 0.000). The 1-, 3-, and 5-year locoregional control rates were 71.6%, 34.3% and 31.0% for patients treated with 3D radiotherapy and 57.3%, 22.1% and 19.2%, respectively, for patients treated with 2D treatment (P = 0.002). The results of multivariate analysis showed that 3D-CRT, KPS, clinical tumor response and pretreatment hemoglobin level were independently associated with increased OS and CSS. No statistically significant differences were found between the radiation complications in the two groups. CONCLUSIONS: The results of our study demonstrate that 3D-conformal radiotherapy improves the survival rate in patients with stage III NSCLC compared with that of 2D radiation therapy.

Newly identified essential amino acid residues affecting Δ8-sphingolipid desaturase activity revealed by site-directed mutagenesis.

In order to identify amino acid residues crucial for the enzymatic activity of Δ(8)-sphingolipid desaturases, a sequence comparison was performed among Δ(8)-sphingolipid desaturases and Δ(6)-fatty acid desaturases from various plants. In addition to the known conserved cytb(5) (cytochrome b(5)) HPGG motif and three conserved histidine boxes, they share additional 15 completely conserved residues. A series of site-directed mutants were generated using our previously isolated Δ(8)-sphingolipid desaturase gene from Brassica rapa to evaluate the importance of these residues to the enzyme function. The mutants were functionally characterized by heterologous expression in yeast, allowing the identification of the products of the enzymes. The results revealed that residues H63, N203, D208, D210, and G368 were obligatorily required for the enzymatic activity, and substitution of the residues F59, W190, W345, L369 and Q372 markedly decreased the enzyme activity. Among them, replacement of the residues W190, L369 and Q372 also has significant influence on the ratio of the two enzyme products. Information obtained in this work provides the molecular basis for the Δ(8)-sphingolipid desaturase activity and aids in our understanding of the structure-function relationships of the membrane-bound desaturases.

Genes encoding the biotin carboxylase subunit of acetyl-CoA carboxylase from Brassica napus and parental species: cloning, expression patterns, and evolution.

Comparative genomics is a useful tool to investigate gene and genome evolution. Biotin carboxylase (BC), an important subunit of heteromeric acetyl-CoA carboxylase (ACCase) that is a rate-limiting enzyme in fatty acid biosynthesis in dicots, catalyzes ATP, biotin carboxyl carrier protein, and CO2 to form carboxybiotin carboxyl carrier protein. In this study, we cloned four genes encoding BC from Brassica napus L. (namely BnaC.BC.a, BnaC.BC.b, BnaA.BC.a, and BnaA.BC.b), and two were cloned from each of the two parental species Brassica rapa L. (BraA.BC.a and BraA.BC.b) and Brassica oleracea L. (BolC.BC.a and BolC.BC.b). Sequence analyses revealed that in B. napus the genes BnaC.BC.a and BnaC.BC.b were from the C genome of B. oleracea, whereas BnaA.BC.a and BnaA.BC.b were from the A genome of B. rapa. Comparative and cluster analysis indicated that these genes were divided into two major groups, BnaC.BC.a, BnaA.BC.a, BraA.BC.a, and BolC.BC.a in group-1 and BnaC.BC.b, BnaA.BC.b, BraA.BC.b, and BolC.BC.b in group-2. The divergence of group-1 and group-2 genes occurred in their common ancestor 13-17 million years ago (MYA), soon after the divergence of Arabidopsis and Brassica (15-20 MYA). This time of divergence is identical to the previously reported triplicated time of paralogous subgenomes of diploid Brassica species and the divergence date of group-1 and group-2 genes of α-carboxyltransferase, another subunit of heteromeric ACCase, in Brassica. Reverse transcription PCR revealed that the expression level of group-1 and group-2 genes varied in different organs, and the expression patterns of the two groups of genes were similar in different organs, except in flower. However, two paralogs of group-2 BC genes from B. napus could express differently in mature plants tested by generating BnaA.BC.b and BnaC.BC.b promoter-ß-glucuronidase (GUS) fusions. The amino acid sequences of proteins encoded by these genes were highly conserved, except the sequence encoding predicted plastid transit peptides. The plastid transit peptides on the BC precursors of Brassica (71-72 amino acid residues) were predicted based on AtBC protein, compared, and confirmed by fusion with green fluorescent protein. Our results will be helpful in elucidating the evolution and the regulation of ACCase in the genus Brassica.

Stereotactic body radiation therapy favors long-term overall survival in patients with lung metastases: five-year experience of a single-institution.

BACKGROUND: Metastatic lung cancer is one of the most common oncologic problems. This study aimed to evaluate the long-term clinical outcome of stereotactic body radiation therapy (SBRT) for metastatic lung tumors. METHODS: We retrospectively reviewed the 71 patients with lung metastases, who had 172 lesions treated with SBRT from January 2000 to December 2006. All patients were unfit or failed after surgery and/or chemotherapy. The median total dose was 48 Gy (range, 30 - 60) in 4 (range, 2 - 12) fractions. The median size of the irradiated lesions was 2.1 cm (range, 0.9 - 7.9 cm). RESULTS: All but two patients received follow up. The median follow-up time was 24.7 months (range, 2.9 - 114.4 months). The median follow-up time for living patients was 86.8 months (range, 58.1 - 114.4 months). The 1-, 3-, 5-year local control and overall survival rates were 88.8%, 75.4%, 75.4% and 78.9%, 40.8%, 25.2%. Multivariate analysis showed that the absence of extrapulmonary metastases (P = 0.024; hazard ratio (HR), 1.894; 95% confidence interval (CI), 1.086 - 3.303) and disease-free interval ≤ 12 months (P = 0.014; HR, 0.511; 95%CI, 0.299 - 0.873) were independent prognostic factors. No grade 3 or more acute and late toxicities occurred. Only one patient developed a non-symptomatic rib fracture. CONCLUSION: SBRT could be an alternative treatment to surgery for subsets of patients with lung metastases with favorable long-term survival and tolerable complications.

Genes encoding the alpha-carboxyltransferase subunit of acetyl-CoA carboxylase from Brassica napus and parental species: cloning, expression patterns, and evolution.

Heteromeric acetyl coenzyme A carboxylase (ACCase), a rate-limiting enzyme in fatty acid biosynthesis in dicots, is a multi-enzyme complex consisting of biotin carboxylase, biotin carboxyl carrier protein, and carboxyltransferase (alpha-CT and beta-CT). In the present study, four genes encoding alpha-CT were cloned from Brassica napus, and two were cloned from each of the two parental species, B. rapa and B. oleracea. Comparative and cluster analyses indicated that these genes were divided into two major groups. The major divergence between group-1 and group-2 occurred in the second intron. Group-2 alpha-CT genes represented the ancestral form in the genus Brassica. The divergence of group-1 and group-2 genes occurred in their common ancestor 12.96-17.78 million years ago (MYA), soon after the divergence of Arabidopsis thaliana and Brassica (15-20 MYA). This time of divergence is identical to that reported for the paralogous subgenomes of diploid Brassica species (13-17 MYA). Real-time reverse transcription PCR revealed that the expression patterns of the two groups of genes were similar in different organs, except in leaves. To better understand the regulation and evolution of alpha-CT genes, promoter regions from two sets of orthologous gene copies from B. napus, B. rapa, and B. oleracea were cloned and compared. The function of the promoter of gene Bnalpha-CT-1-1 in group-1 and gene Bnalpha-CT-2-1 in group-2 was examined by assaying beta-glucuronidase activity in transgenic A. thaliana. Our results will be helpful in elucidating the evolution and regulation of ACCase in oilseed rape.

Identification and functional analysis of the genes encoding Delta6-desaturase from Ribes nigrum.

Gamma-linolenic acid (gamma-linolenic acid, GLA; C18:3 Delta(6, 9, 12)) belongs to the omega-6 family and exists primarily in several plant oils, such as evening primrose oil, blackcurrant oil, and borage oil. Delta(6)-desaturase is a key enzyme involved in the synthesis of GLA. There have been no previous reports on the genes encoding Delta(6)-desaturase in blackcurrant (Ribes nigrum L.). In this research, five nearly identical copies of Delta(6)-desaturase gene-like sequences, named RnD8A, RnD8B, RnD6C, RnD6D, and RnD6E, were isolated from blackcurrant. Heterologous expression in Saccharomyces cerevisiae and/or Arabidopsis thaliana confirmed that RnD6C/D/E were Delta(6)-desaturases that could use both alpha-linolenic acids (ALA; C18:3 Delta(9,12,15)) and linoleic acid (LA; C18:2 Delta(9,12)) precursors in vivo, whereas RnD8A/B were Delta(8)-sphingolipid desaturases. Expression of GFP tagged with RnD6C/D/E showed that blackcurrant Delta(6)-desaturases were located in the mitochondrion (MIT) in yeast and the endoplasmic reticulum (ER) in tobacco. GC-MS results showed that blackcurrant accumulated GLA and octadecatetraenoic acids (OTA; C18:4 Delta(6,9,12,15)) mainly in seeds and a little in other organs and tissues. RT-PCR results showed that RnD6C and RnD6E were expressed in all the tissues at a low level, whereas RnD6D was expressed at a high level only in seeds, leading to the accumulation of GLA and OTA in seeds. This research provides new insights to our understanding of GLA synthesis and accumulation in plants and the evolutionary relationship of this class of desaturases, and new clues as to the amino acid determinants which define precise enzyme activity.

Advances in chloroplast engineering.

The chloroplast is a pivotal organelle in plant cells and eukaryotic algae to carry out photosynthesis, which provides the primary source of the world's food. The expression of foreign genes in chloroplasts offers several advantages over their expression in the nucleus: high-level expression, transgene stacking in operons and a lack of epigenetic interference allowing stable transgene expression. In addition, transgenic chloroplasts are generally not transmitted through pollen grains because of the cytoplasmic localization. In the past two decades, great progress in chloroplast engineering has been made. In this paper, we review and highlight recent studies of chloroplast engineering, including chloroplast transformation procedures, controlled expression of plastid transgenes in plants, the expression of foreign genes for improvement of plant traits, the production of biopharmaceuticals, metabolic pathway engineering in plants, plastid transformation to study RNA editing, and marker gene excision system.

[Effect of different chemotherapy regimens for concurrent chemoradiotherapy on locally advanced non-small cell lung cancer].

OBJECTIVE: To retrospectively analyze the effects of different chemotherapy regimens for concurrent chemoradiation on locally advanced non-small cell lung cancer (NSCLC). METHODS: The data from 106 patients diagnosed as locally advanced NSCLC (IIIa: 29, IIIb: 77), who received various chemotherapy regimens for concurrent chemoradiotherapy, were retrospectively analyzed. Paclitaxel-based chemotherapy regimen was administered in 55 patients, topotecan regimen in 21 patients, PE (cisplatin and etopside) regimen in 26 patients, and other regimens in the remaining 4 patients. The effect of different chemotherapy regimens on overall survival and toxicity was analyzed. RESULTS: The median survival time was 18.6 months, and the overall 1- and 3-year survival rates were 72.2% and 27.5%, respectively. The median survival time of 102 patients treated with paclitaxel-containing, topotecan-containing or PE regimens was 16.3, 27.3 and 29.1 months, respectively. The overall survival times of topotecan and PE groups were superior to that of paclitaxol-based group, but not significantly different (P = 0.32). Both univariate and multivariate analysis showed that paclitaxol-based chemotherapy regimen was significantly associated with a poorer survival (P < 0.05). N stage was another significant prognostic factor determined by COX multivariate regression model. Compared with the other regimens (10.6%), paclitaxel-based regimen (27.3%) had more acute radiation pneumonitis (grade >or= 2, P = 0.03), but no significant differences were observed in blood toxicity and esophagitis. CONCLUSION: There is a correlation between different chemotherapy regimens for concurrent chemoradiotherapy and the overall survival and acute radiation pneumonitis in patients with locally advanced NSCLC.

Isolation of expressed sequences from a specific chromosome of Thinopyrum intermedium infected by BYDV.

To map important ESTs to specific chromosomes and (or) chromosomal regions is difficult in hexaploid wheat because of its large genome size and serious interference of homoeologous sequences. Large-scale EST sequencing and subsequent chromosome localization are both laborious and time-consuming. The wheat alien addition line TAi-27 contains a pair of chromosomes of Thinopyrum intermedium (Host) Barkworth & D.R. Dewey that carry the resistance gene against barley yellow dwarf virus. In this research, we developed a modified technique based on chromosome microdissection and hybridization-specific amplification to isolate expressed sequences from the alien chromosome of TAi-27 by hybridization between the DNA of the microdissected alien chromosome and cDNA of Th. intermedium infected by barley yellow dwarf virus. Twelve clones were selected, sequenced, and analyzed. Three of them were unknown genes without any hit in the GenBank database and the other nine were highly homologous with ESTs of wheat, barley, and (or) other plants in Gramineae induced by abiotic or biotic stress. The method used in this research to isolate expressed sequences from a specific chromosome has the following advantages: (i) the obtained expressed sequences are larger in size and have 3' end information and (ii) the operation is less complicated. It would be an efficient improved method for genomics and functional genomics research of polyploid plants, especially for EST development and mapping. The obtained expressed sequence data are also informative in understanding the resistance genes on the alien chromosome of TAi-27.

Rapid EST isolation from chromosome 1R of rye.

BACKGROUND: To obtain important expressed sequence tags (ESTs) located on specific chromosomes is currently difficult. Construction of single-chromosome EST library could be an efficient strategy to isolate important ESTs located on specific chromosomes. In this research we developed a method to rapidly isolate ESTs from chromosome 1R of rye by combining the techniques of chromosome microdissection with hybrid specific amplification (HSA). RESULTS: Chromosome 1R was isolated by a glass needle and digested with proteinase K (PK). The DNA of chromosome 1R was amplified by two rounds of PCR using a degenerated oligonucleotide 6-MW sequence with a Sau3AI digestion site as the primer. The PCR product was digested with Sau3AI and linked with adaptor HSA1, then hybridized with the Sau3AI digested cDNA with adaptor HSA2 of rye leaves with and without salicylic acid (SA) treatment, respectively. The hybridized DNA fragments were recovered by the HSA method and cloned into pMD18-T vector. The cloned inserts were released by PCR using the partial sequences in HSA1 and HSA2 as the primers and then sequenced. Of the 94 ESTs obtained and analyzed, 6 were known sequences located on rye chromosome 1R or on homologous group 1 chromosomes of wheat; all of them were highly homologous with ESTs of wheat, barley and/or other plants in Gramineae, some of which were induced by abiotic or biotic stresses. Isolated in this research were 22 ESTs with unknown functions, probably representing some new genes on rye chromosome 1R. CONCLUSION: We developed a new method to rapidly clone chromosome-specific ESTs from chromosome 1R of rye. The information reported here should be useful for cloning and investigating the new genes found on chromosome 1R.

[Postoperative three-dimensional conformal radiotherapy for resected non-small cell lung cancer].

OBJECTIVE: To investigate the association between survival and postoperative three-dimensional conformal radiotherapy (3DCRT) in patients with resected non-small cell lung cancer (NSCLC). METHODS: Eighty-four patients were treated with surgery and postoperative 3DCRT for NSCLC. Sixty-five (77.4%) patients received lobectomy, and 19 (22.6%) received pneumonectomy. Fifty-four (64.3%) patients achieved R0 resection and 30 cases (35.8%) received R1/R2 resection. Fifty-two patients were of stage IIIA and 24 patients were of stage IIIB. Photon energy of 6 MV was used for all the patients. The median 3DCRT dose was 60 Gy (40 - 70 Gy) with a fraction size of 2 Gy. Thirty-seven patients received median 3 cycles of adjuvant chemotherapy. The median follow-up was 35.5 months for survivors. RESULTS: The overall 3-year survival rate was 58.6%, and the 4-year overall survival rate was 43.9%. Of the 43 patients who had treatment failure, only 8 (9.9%) patients showed intrathoracic recurrence, but 38 (46.9%) patients had distant metastasis. The univariate analysis for all patients showed that sex, age, weight loss, tumor size, pathology and stage were not correlated with prognosis. R1/R2 resection was associated with a significantly worse survival. Toxicities were acceptable, with 9 (11.1%) patients appeared higher than NCI CTC grade 2 radiation pneumonitis. CONCLUSION: In a population-based cohort, postoperative 3DCRT for NSCLC provides a good prognosis, and the radiation-related pneumonitis is acceptable.

[Function of the putative Na+/H+ antiporter gene PeNhaD1 from salt-resistant Populus euphratica Oliv].

Yeast complementation experiments were carried out to define the possible function of PeNhaD1, a Na(+)/H(+) antiporter gene from Populus euphratica Oliv., a salt resistant tree. PeNhaD1 was introduced to the Saccharomyces cerevisiae mutant strain ANT3 (Deltaena1-4::HIS3 Deltanha1::LEU2), which lacks the plasma membrane Na(+)/H(+) antiporter gene ScNHA1 or GX1 (Deltanhx1::TRP1), which lacks tonoplast Na(+)/H(+) antiporter gene ScNHX1. Our results showed that PeNhaD1 rescued the normal growth of ANT3 in the presence of high salt (80 mmol/L NaCl on solid medium or 400 mmol/L in liquid medium, pH 6.0), but not that of GX1, suggesting that PeNhaD1 may play a role in salt tolerance of Populus euphratica by maintaining the capacity for salt exclusion under saline condition.

[Prognosis of locally advanced non small cell lung cancer treated with three dimentional conformal radiotherapy].

OBJECTIVE: To summarize our experience and evaluate the prognostic factors of locally advanced non small cell lung cancer (LA-NSCLC) treated with three dimentional conformal radiotherapy (3D-CRT). METHODS: 118 patients with stage IIImA/IIIB non small cell lung cancer were treated with 3D-CRT from Nov. 2001 to Mar. 2005. 113 patients with complete clinical data were eligible for analysis, 45 of them received radiotherapy alone; 39 were treated by concurrent chemoradiation with paclitaxol plus carboplatin in 32 patients and topotecan in 7 patients, and 29 by sequential chemoradiation with platinum-based regiment in most of them. The dose of radiation for the thoracic field ranged from 26 Gy to 75 Gy with a median dose of 60 Gy. GTV and PTV were collected from the 3D treatment plans in 79 and 101 patients, respectively. Overall survival (OS) was calculated using the Kaplan-Meier method. Comparisons among the curves were made using a two-tailed long-rank test. The Cox model was used for multivariate analysis. RESULTS: The 1-, 2- and 3-year overall survival rate was 60.7%, 31.6% and 22.4%, respectively, with a median survival time of 17 months. In univariate analysis, the following characteristics were significantly associated with longer survival: absence of chest pain, good karnofsky performance status (KPS), albumin > 4.2 g/L, hemoglobin > or = 140 g/L (male) or 130 g/L (female), response to radiotherapy and GTV < 100 cm3. However, multivariate analysis revealed that only good KPS was an independent risk factor predicting the survival. CONCLUSION: Three-dimensional conformal radiotherapy is effective in the treatment of locally advanced non-small cell lung cancer with acceptable complications. Karnofsky performance status is the only independent prognositic factor.

[Three-dimensional conformal radiotherapy for locoregionally recurrent non-small cell lung cancer after initial radiotherapy].

OBJECTIVE: To evaluate the feasibility, therapeutic effects and normal tissue complications of three-dimensional conformal radiotherapy (3DCRT) for locoregionally recurrent non-small cell lung cancer after initial radiotherapy. METHODS: Between August 1999 and August 2003, 27 such patients were treated with 3DCRT after initial radiotherapy. This series consisted of 25 men and 2 women with a median age of 64 years. Radiotherapy was delivered at 2 Gy per fraction, 5 fractions per week, to a median dose of 50 Gy. Treatment results and normal tissue complications were assessed with WHO and RTOG/EORTC criteria. RESULTS: Based upon a median follow-up time of 20.6 months, 25 patients (92.6%) completed the planned 3DCRT treatment. Their clinical symptom relief rate was 79.1%, and the response rate was 59.3% with a complete remission rate of 14.8% (4/27), partial remission rate of 44.4% (12/27). The overall 1- and 2-year survival (OS) rates were 73.8% and 25.4% with a median survival time (MST) of 20 months. The 1- and 2-year local progression free survival (LPFS) rates were both 88.8%. Grade 2 and grade 3 acute radiation pneumonitis developed in 7.4% (2/27) and 11.1% (3/27). Grade 2 late radiation pneumonitis developed in 11.1% (3/27). CONCLUSION: 3DCRT is feasible and advisable for locoregionally recurrent non-small-cell lung cancer, giving a good immediate tumor response and acceptable normal tissue complications.

[SPECT lung perfusion scans in predicting radiation pneumonitis in lung cancer patients].

OBJECTIVE: To evaluate single photon emission computed tomography (SPECT) lung perfusion in predicting radiation pneumonitis in lung cancer patients. METHODS: From April 2003 to March 2004, 31 lung cancer patients treated with radical radiotherapy received SPECT lung perfusion scans, among whom, 23 had had perfusion scans both before and at the time of 40 Gy irradiation. The perfusion changes in the region of interest (ROI) after irradiation were obtained through comparing post-radiotherapy with pre-radiotherapy average proportion of SPECT counts within the ROI relative to average counts of the whole lung. Endpoint was defined as grade 2 and above radiation pneumonitis according to RTOG criteria. RESULTS: Lung perfusion defect was observed in all the patients at baseline. > or = grade 2 lung perfusion defect was found in 68.2% (15/22) of patients with central lesion and in 22.2% (2/9) of patients with peripheral lesions (P = 0.04). Seventy percent of the patients (16/23) experienced improved perfusion at 40 - 50 Gy. > or = grade 2 radiation pneumonitis was observed in 12 patients (38.7%) in the whole group, with 6 in those with grade 1 perfusion defects and another 6 in > or = grade 2 group, respectively; Of the 23 patients who had had both pre- and post-radiotherapy SPECT perfusion scan, 5 > or = grade 2 radiation pneumonitis occurred in the 16 perfusion-improved patients and 3 in the 7 unimproved patients. CONCLUSION: There is no significant correlation between radiation pneumonitis and the extent of perfusion defect either before or after 40 - 50 Gy irradiation based on our limited data analysis in this series.