The genetic variation and phylogenetic relationships of Citrus tristeza virus （CTV） isolates collected from Chinese wild type citrus were analyzed by comparing the sequences of nine genomic regions （p23, p20, p13, ...The genetic variation and phylogenetic relationships of Citrus tristeza virus （CTV） isolates collected from Chinese wild type citrus were analyzed by comparing the sequences of nine genomic regions （p23, p20, p13, p18, p25, p27, POL, HEL and k17） with the CTV isolates of cultivated citrus from different countries. The results showed that the divergence pattern of genomic RNA of the CTV isolates from wild type citrus was similar to that of other isolates from cultivated citrus, the 3′ proximal region was relatively conserved, and the 5′ proximal region had greater variability. The nine genomic regions of CTV isolates analyzed were found to have been under purifying selection in the evolution process. Phylogenetic analysis showed that the eleven Chinese wild CTV isolates were located at different clades and did not relfect their geographical origins, suggesting genetic diversity among the Chinese wild CTV populations. These results will aid in the understanding of molecular evolution of the Chinese CTV populations.展开更多
AIM: To further elucidate the possible molecular biological activity of wild type K-ras2 gene by detecting changes in wild type K-ras2 gene-induced gene-expression profiles of colon carcinoma cells using cDNA microarr...AIM: To further elucidate the possible molecular biological activity of wild type K-ras2 gene by detecting changes in wild type K-ras2 gene-induced gene-expression profiles of colon carcinoma cells using cDNA microarray techniques. METHODS: Total RNA was isolated from peripheral blood of health volunteers. Reverse transcription of RNA and polymerase chain reaction were used to synthesize wild type K-ras2 cDNA. K-ras2 cDNA fragment was cloned into a T easy vector and sequenced. A eukaryotic expression vector pCI-neo-K-ras2 was constructed and transfected to Caco2 cell line using the liposome method. Finally, mRNA was isolated, reverse-transcribed to cDNA from pCI-neo-K-ras2 or pCI-neo blank vector-transfected Caco cells, and analyzed by cDNA microarray assay. RESULTS: Restriction enzyme analysis and DNA sequencing verified that the constructed expression vector was accurate. High-quality RNA was extracted and reverse transcribed to cDNA for microarray assay. Among the 135 genes, the expression was up-regulated in 24 and down-regulated in 121. All these differentially expressed genes were related to cell proliferation, differentiation, apoptosis and signal transduction. CONCLUSION: Differentially expressed genes can be successfully screened from wild type K-ras2-transfected colon carcinoma cells using microarray techniques. The results of our study suggest that wild type K-ras2 is related to the negative regulation of cell proliferation, metabolism and transcriptional control, and provide new clues to the further elucidation of its possible biological activity.展开更多
Sago mushrooms (SMs) are an edible fungus that is favorite food for community in Papua and West Papua, Indonesia in particular. This work aims to determine the morphological characteristics and nutritional value of SM...Sago mushrooms (SMs) are an edible fungus that is favorite food for community in Papua and West Papua, Indonesia in particular. This work aims to determine the morphological characteristics and nutritional value of SMs growing naturally in Manokwari. Morphological characteristic of SMs that grows wild in Manokwari has an average of pileus diameter 9.53 cm, pileus weight 21.53 grams, and pileus color. The pileus color is divided into three colors: outer circle color is RHS163D, middle circle color is RHS199B, and inner circle color is RHS199A. Average of stipe diameter, length, and weight is 1.00 cm, 10.43 cm, and 9.15 gram respectively. Stipe is a yellowish white color (RHS155B). SMs nutrient content that grows naturally in Manokwari is potassium 1394.02 milli-grams and calcium 13.37 milligrams per 1000 grams fresh weight. The others nutrient contents of SMs that are measured are fat 1.01 grams, protein 1.30 grams, carbohydrates 0.18 grams, phosphorus 0.34 milligrams, and energy 15.01 kilocalories per 100 grams of fresh weight.展开更多
Background: This study was performed to evaluate the efficacy and safety of switch maintenance therapy with oral vinorelbine in advanced non-small cell lung cancer (NSCLC) with adenocarcinoma limited to epidermal grow...Background: This study was performed to evaluate the efficacy and safety of switch maintenance therapy with oral vinorelbine in advanced non-small cell lung cancer (NSCLC) with adenocarcinoma limited to epidermal growth factor receptor (EGFR) wild type. Materials and Methods: In this single randomized trial, patients with advanced stage (IIIB and IV) NSCLC with adenocarcinoma EGFR wild-type status, treated with 6 cycles of platinum based chemotherapy. Patients did not show progression after first-line chemotherapy were randomly assigned to receive switch maintenance with vinorelbine (80 mg/m2, day 1, 8) (group I) or the best supportive care until disease progression (group II). Results: The median progression free survival (PFS) was 9.7 months for group I versus 5.7 months for group II with statistically significant difference between both groups [HR = 1.15;95% CI 1.19 to 1.49;P value = 0.002], while the median overall survival (OS) was 13.2 months for group I versus 11.9 months for group II with no statistically significant differences between both groups [HR = 1.24;95% CI 1.05 to 1.46;P value = 0. 3]. The patients who received oral vinorelbine had tolerable toxicity profile. Conclusion: Switch maintenance therapy with oral vinorelbine, though improve PFS, did not improve OS in patients with NSCLC with adenocarcinoma EGFR wild type.展开更多
BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of ...BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.展开更多
The reversing effect of wild-type PTEN gene on resistance of C 13K cells to cisplatin and its inhibitory effect on the phosphorylation of protein kinase B （AKT） were studied. The expression of PTEN mRNA and protein ...The reversing effect of wild-type PTEN gene on resistance of C 13K cells to cisplatin and its inhibitory effect on the phosphorylation of protein kinase B （AKT） were studied. The expression of PTEN mRNA and protein in OV2008 cells and C13K cells were semi-quantitatively detected by using RT-PCR and Western blotting. Recombinant eukaryotic expression plasmid containing human wild-type PTEN gene was transfected into C13K cells by lipofectamine2000. The expression of PTEN mRNA was monitored by RT-PCR and the expression of PTEN, Akt, p-Akt protein were ana- lyzed by Western blotting in PTEN-transfected and non-transfected C13K cells. Proliferation and chemosensitivity of cells to DDP were measured by MTT, and cell apoptosis was detected by flow cytometry after treatment with cisplatin. The expression of PTEN mRNA and protein in OV2008 cells were significantly higher than those in C13K cells. After transfection with PTEN gene for 48 h, the expression of PTEN mRNA and protein in C 13K cells were 2.04 ± 0.10, 0.94± 0.04 respectively and the expression of p-Akt protein （ 0.94± 0.07） was lower than those in control groups （1.68 ±0.14, 1.66± 0.10） （P〈 0.05）. The IC50 of DDP to C 13 K cells transfected with PTEN （7.2± 0.3 la mol/L） was obviously lower than those of empty-vector transfected cells and non-transfected cells （12.7±0.4 lamol/1, 13.0±0.3 lamol/L） （P〈0.05）. The apopototis ratio of wild-type PTEN-transfected, empty vector transfected and non-transfected C13K cells were （41.65___0.87）%, （18.61 ±0.70）% and （15.28±0.80）% respectively, and the difference was statistically significant （P〈0.05）. PTEN gene plays an important role in ovarian cancer multidrug resistance. Transfection of PTEN could increase the expression of PTEN and restore drug sensitivity to cisplatin in human ovarian cancer cell line C 13K with multidrug-resistance by decreasing the expression of p-Akt.展开更多
The goal of this study was to determine whether mutation of the Mn-binding site of wild-type recombinant Phlebia radiata manganese peroxidase 3 affected the pH-dependence kinetic parameters. pH range investigated was ...The goal of this study was to determine whether mutation of the Mn-binding site of wild-type recombinant Phlebia radiata manganese peroxidase 3 affected the pH-dependence kinetic parameters. pH range investigated was 2.5 – 12.0. The catalytic efficiency of the mutant enzymes at high and low pH in comparison to the wild-type was investigated using standard rPr-MnP3 protocol. Wild-type recombinant Phlebia radiata MnP3 enzyme showed optimal activity with Mn (II) as substrate at pH 5.0 and remained moderately active (approximately 40%) in the pH range of 6.0 - 9.0. The rPr-MnP3 mutants’ maximum activity ranged between 5.5 and 8.0. Wild-type and mutants rPr-MnP3 enzymes exhibited a similar pH profile with optimum pH of 3.0 for ABTS oxidation. Mutation has severely decreased the catalytic efficiency for Mn (II) oxidation at pH 5.0. The rPr-MnP3 enzymes showed enhanced affinity for Mn (II) at alkaline pH and a more alkaline range for catalysis than ever reported for any Manganese Peroxidase. This study reveals that at higher pH, rPr-MnP3 can function with alternative ligands in the Mn (II) site and does not have an absolutely obligate requirement for an all carboxylate ligand set. These results further strongly confirm that Mn<sup>2+</sup> binding site is the only productive catalytic site for Mn (II) oxidation.展开更多
K-ras wild-type carcinoma is a tumour that is sensitive to treatment with anti-cancer and anti-EGFR drugs: the combination of Cetuximab and Panitumumab with chemotherapy (Cetuximab) or as a single therapy (Panitumumab...K-ras wild-type carcinoma is a tumour that is sensitive to treatment with anti-cancer and anti-EGFR drugs: the combination of Cetuximab and Panitumumab with chemotherapy (Cetuximab) or as a single therapy (Panitumumab). Case Report: The clinical case presented here refers to a 68-year-old patient who had been diagnosed with adenocarcinoma of the recto sigmoid with pelvic recurrence three years after surgery. The patient had a severe co-morbidity: correlated B-type liver cirrhosis. First-line chemotherapy was begun with Oxaliplatin plus Capecitabine (CAPOXI) following a relapse, and this continued for six months (six cycles), when the treatment was interrupted because of the disease’s progression and hematological and gastrointestinal toxicity. Following an assessment of the K-ras, diagnosed as wild type, the patient was excluded from second-line chemotherapy treatment because of decompensated cirrhosis and the persistence of thrombocytopenia and leukopenia. The patient was put forward for biological treatment with an anti-EGFR monoclonal antibody (Panitumumab). Panitumumab was administered at a dosage of 6 mg/kg every 2 weeks for 17 months;the treatment was well tolerated, despite the cirrhosis, and the main toxicity was the skin rash. Conclusion: In patients with severe comorbidities such as cirrhosis of the liver and K-ras wild-type carcinomas, therapy with a monoclonal antibody such as Panitumumab is a treatment that is well tolerated, with few serious toxic side-effects;it also offers advantages in terms of survival and clinical benefits.展开更多
The effect of endosulfan, a hexachlorinated pesticide, on growth, inorganic nitrogenous nutrient uptake (NO3-, NO2- and NH4+), change in pigmentation and glycogen content on wild type and chemically mutagenised cells ...The effect of endosulfan, a hexachlorinated pesticide, on growth, inorganic nitrogenous nutrient uptake (NO3-, NO2- and NH4+), change in pigmentation and glycogen content on wild type and chemically mutagenised cells of Synechococcus cedrorum was investigated. The pattern of response to pesticide stress in wild and mutant type was the same. Growth reappeared in both after a period of initial lag in presence of endosulfan. The duration of lag increased with increasing doses of pesticide. Paradoxically, however, the rate of uptake of NO-3, NO-2 and NH+4 pigment and glycogen content progressively increased with increasing doses. The difference in the adaptation response between wild and mutant types was observed only in the concentration of pesticide that could be tolerated; with the mutant tolerating 2.5 fold more.展开更多
The coat protein （CP） genes were cloned and sequenced from viral particles of 11 isolates of citrus tristeza virus （CTV） collected from wild citrus plants in China and 4 Chinese isolates from cultivated sweet oran...The coat protein （CP） genes were cloned and sequenced from viral particles of 11 isolates of citrus tristeza virus （CTV） collected from wild citrus plants in China and 4 Chinese isolates from cultivated sweet orange and pummelo varieties, respectively. By analyzing and comparing the nucleotide and amino acid sequences of CP genes, the 11 wild CTV isolates were found over 92% identical with 4 Chinese CTV isolates and 21 exotic CTV isolates from cultivated citrus. From 91 to 100% of the CTV CP gene sequences in wild type citrus plants were generally well conserved. Genetic evolution analysis indicated that the GC% of the CP gene was less than AT%, and more transition were found in the CP genes than transversion with the transition/transversion ratio ranging from 6.3 to 7.0 among species. The substitution frequency was the highest at the third codon, followed by the first and second codon. The ratio of non-synonymous mutations （du） to synonymous mutations （ds） was far lower than 1, suggesting that the CP gene might have experienced purifying selection in the evolution. Phylogenetic analysis revealed that the 11 CTV isolates in Chinese wild type citrus belonged to different phylogenetic clusters, and shared higher homology and closer relationships with other cultivated citrus CTV isolates from different countries, which indicated complicated genetic relationships among the CTV isolates. In addition, CTV isolates with similar biological characteristics usually located into the same clusters. Therefore, the conclusion was drawn that pathogenicity was critical to evolution and origin of CTV.展开更多
More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but s...More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but second in mortality.More than half of the patients are in advanced stages at diagnosis.Treatment options are complex because of the heterogeneity of the patient population,including different molecular subtypes.Treatments have included conventional fluorouracil-based chemotherapy,targeted therapy,immunotherapy,etc.In recent years,with the development of genetic testing technology,more and more targeted drugs have been applied to the treatment of CRC,which has further prolonged the survival of metastatic CRC patients.展开更多
BACKGROUND Metastatic colorectal cancer(mCRC)treatment has been evolving and increasingly driven by tumor biology and gene expression analysis.Rechallenge with epidermal growth factor receptor(EGFR)inhibitors(anti-EGF...BACKGROUND Metastatic colorectal cancer(mCRC)treatment has been evolving and increasingly driven by tumor biology and gene expression analysis.Rechallenge with epidermal growth factor receptor(EGFR)inhibitors(anti-EGFR)represents a promising strategy for patients with RAS wild-type(RAS-wt)mCRC and circulating tumor DNA has emerged as a potential selection strategy.Herein,we report the case of a RAS-wt mCRC patient who had a successful response to cetuximab rechallenge.CASE SUMMARY Our patient was diagnosed with stage IV RAS-wt,microsatellite-stable rectosigmoid junction adenocarcinoma.He was started on first-line treatment with FOLFIRI and cetuximab and achieved partial response,allowing for a left hepatectomy(R0),followed by post-operative chemotherapy and an anterior resection;progression-free survival(PFS)of 16 months was obtained.Due to hepatic and nodal relapse,second-line treatment with FOLFOX and bevacizumab was started with partial response;metastasectomy was performed(R0),achieving a PFS of 11 months.After a 15 months anti-EGFR-free interval,FOLFIRI and cetuximab were reintroduced upon disease progression,again with partial response and a PFS of 16 months.Following extensive hepatic relapse,cetuximab was reintroduced and a marked clinical and analytical improvement was seen,after only one cycle.RASwt status was confirmed on circulating tumor DNA.The patient’s overall survival exceeded 5 years.CONCLUSION Our case provides real-world data to support cetuximab rechallenge in later lines of RAS-wt mCRC treatment.展开更多
基金supported by the National Natural Science Foundation of China (30900977)the Program for Changjiang Scholars and Innovative Research Team in Universities, China (PCSIRT, IRT0976)+1 种基金the Key Project 210111 of Ministry of Education of Chinathe Young Scientist Cultivation Program of Jiangxi, China (2010DQ02300)
文摘The genetic variation and phylogenetic relationships of Citrus tristeza virus （CTV） isolates collected from Chinese wild type citrus were analyzed by comparing the sequences of nine genomic regions （p23, p20, p13, p18, p25, p27, POL, HEL and k17） with the CTV isolates of cultivated citrus from different countries. The results showed that the divergence pattern of genomic RNA of the CTV isolates from wild type citrus was similar to that of other isolates from cultivated citrus, the 3′ proximal region was relatively conserved, and the 5′ proximal region had greater variability. The nine genomic regions of CTV isolates analyzed were found to have been under purifying selection in the evolution process. Phylogenetic analysis showed that the eleven Chinese wild CTV isolates were located at different clades and did not relfect their geographical origins, suggesting genetic diversity among the Chinese wild CTV populations. These results will aid in the understanding of molecular evolution of the Chinese CTV populations.
基金National Natural Science Foundation of China, No. 30200326
文摘AIM: To further elucidate the possible molecular biological activity of wild type K-ras2 gene by detecting changes in wild type K-ras2 gene-induced gene-expression profiles of colon carcinoma cells using cDNA microarray techniques. METHODS: Total RNA was isolated from peripheral blood of health volunteers. Reverse transcription of RNA and polymerase chain reaction were used to synthesize wild type K-ras2 cDNA. K-ras2 cDNA fragment was cloned into a T easy vector and sequenced. A eukaryotic expression vector pCI-neo-K-ras2 was constructed and transfected to Caco2 cell line using the liposome method. Finally, mRNA was isolated, reverse-transcribed to cDNA from pCI-neo-K-ras2 or pCI-neo blank vector-transfected Caco cells, and analyzed by cDNA microarray assay. RESULTS: Restriction enzyme analysis and DNA sequencing verified that the constructed expression vector was accurate. High-quality RNA was extracted and reverse transcribed to cDNA for microarray assay. Among the 135 genes, the expression was up-regulated in 24 and down-regulated in 121. All these differentially expressed genes were related to cell proliferation, differentiation, apoptosis and signal transduction. CONCLUSION: Differentially expressed genes can be successfully screened from wild type K-ras2-transfected colon carcinoma cells using microarray techniques. The results of our study suggest that wild type K-ras2 is related to the negative regulation of cell proliferation, metabolism and transcriptional control, and provide new clues to the further elucidation of its possible biological activity.
文摘Sago mushrooms (SMs) are an edible fungus that is favorite food for community in Papua and West Papua, Indonesia in particular. This work aims to determine the morphological characteristics and nutritional value of SMs growing naturally in Manokwari. Morphological characteristic of SMs that grows wild in Manokwari has an average of pileus diameter 9.53 cm, pileus weight 21.53 grams, and pileus color. The pileus color is divided into three colors: outer circle color is RHS163D, middle circle color is RHS199B, and inner circle color is RHS199A. Average of stipe diameter, length, and weight is 1.00 cm, 10.43 cm, and 9.15 gram respectively. Stipe is a yellowish white color (RHS155B). SMs nutrient content that grows naturally in Manokwari is potassium 1394.02 milli-grams and calcium 13.37 milligrams per 1000 grams fresh weight. The others nutrient contents of SMs that are measured are fat 1.01 grams, protein 1.30 grams, carbohydrates 0.18 grams, phosphorus 0.34 milligrams, and energy 15.01 kilocalories per 100 grams of fresh weight.
文摘Background: This study was performed to evaluate the efficacy and safety of switch maintenance therapy with oral vinorelbine in advanced non-small cell lung cancer (NSCLC) with adenocarcinoma limited to epidermal growth factor receptor (EGFR) wild type. Materials and Methods: In this single randomized trial, patients with advanced stage (IIIB and IV) NSCLC with adenocarcinoma EGFR wild-type status, treated with 6 cycles of platinum based chemotherapy. Patients did not show progression after first-line chemotherapy were randomly assigned to receive switch maintenance with vinorelbine (80 mg/m2, day 1, 8) (group I) or the best supportive care until disease progression (group II). Results: The median progression free survival (PFS) was 9.7 months for group I versus 5.7 months for group II with statistically significant difference between both groups [HR = 1.15;95% CI 1.19 to 1.49;P value = 0.002], while the median overall survival (OS) was 13.2 months for group I versus 11.9 months for group II with no statistically significant differences between both groups [HR = 1.24;95% CI 1.05 to 1.46;P value = 0. 3]. The patients who received oral vinorelbine had tolerable toxicity profile. Conclusion: Switch maintenance therapy with oral vinorelbine, though improve PFS, did not improve OS in patients with NSCLC with adenocarcinoma EGFR wild type.
基金Supported by National Natural Science Foundation of China,No.81601692Program of Liaoning Province Department of Education,No.LK2016002
文摘BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.
基金a grant from the National Natural Sciences Foundation of China (No. 30571950)National Key Basic Research Program Foundation (N0.2002CB513107).
文摘The reversing effect of wild-type PTEN gene on resistance of C 13K cells to cisplatin and its inhibitory effect on the phosphorylation of protein kinase B （AKT） were studied. The expression of PTEN mRNA and protein in OV2008 cells and C13K cells were semi-quantitatively detected by using RT-PCR and Western blotting. Recombinant eukaryotic expression plasmid containing human wild-type PTEN gene was transfected into C13K cells by lipofectamine2000. The expression of PTEN mRNA was monitored by RT-PCR and the expression of PTEN, Akt, p-Akt protein were ana- lyzed by Western blotting in PTEN-transfected and non-transfected C13K cells. Proliferation and chemosensitivity of cells to DDP were measured by MTT, and cell apoptosis was detected by flow cytometry after treatment with cisplatin. The expression of PTEN mRNA and protein in OV2008 cells were significantly higher than those in C13K cells. After transfection with PTEN gene for 48 h, the expression of PTEN mRNA and protein in C 13K cells were 2.04 ± 0.10, 0.94± 0.04 respectively and the expression of p-Akt protein （ 0.94± 0.07） was lower than those in control groups （1.68 ±0.14, 1.66± 0.10） （P〈 0.05）. The IC50 of DDP to C 13 K cells transfected with PTEN （7.2± 0.3 la mol/L） was obviously lower than those of empty-vector transfected cells and non-transfected cells （12.7±0.4 lamol/1, 13.0±0.3 lamol/L） （P〈0.05）. The apopototis ratio of wild-type PTEN-transfected, empty vector transfected and non-transfected C13K cells were （41.65___0.87）%, （18.61 ±0.70）% and （15.28±0.80）% respectively, and the difference was statistically significant （P〈0.05）. PTEN gene plays an important role in ovarian cancer multidrug resistance. Transfection of PTEN could increase the expression of PTEN and restore drug sensitivity to cisplatin in human ovarian cancer cell line C 13K with multidrug-resistance by decreasing the expression of p-Akt.
文摘The goal of this study was to determine whether mutation of the Mn-binding site of wild-type recombinant Phlebia radiata manganese peroxidase 3 affected the pH-dependence kinetic parameters. pH range investigated was 2.5 – 12.0. The catalytic efficiency of the mutant enzymes at high and low pH in comparison to the wild-type was investigated using standard rPr-MnP3 protocol. Wild-type recombinant Phlebia radiata MnP3 enzyme showed optimal activity with Mn (II) as substrate at pH 5.0 and remained moderately active (approximately 40%) in the pH range of 6.0 - 9.0. The rPr-MnP3 mutants’ maximum activity ranged between 5.5 and 8.0. Wild-type and mutants rPr-MnP3 enzymes exhibited a similar pH profile with optimum pH of 3.0 for ABTS oxidation. Mutation has severely decreased the catalytic efficiency for Mn (II) oxidation at pH 5.0. The rPr-MnP3 enzymes showed enhanced affinity for Mn (II) at alkaline pH and a more alkaline range for catalysis than ever reported for any Manganese Peroxidase. This study reveals that at higher pH, rPr-MnP3 can function with alternative ligands in the Mn (II) site and does not have an absolutely obligate requirement for an all carboxylate ligand set. These results further strongly confirm that Mn<sup>2+</sup> binding site is the only productive catalytic site for Mn (II) oxidation.
文摘K-ras wild-type carcinoma is a tumour that is sensitive to treatment with anti-cancer and anti-EGFR drugs: the combination of Cetuximab and Panitumumab with chemotherapy (Cetuximab) or as a single therapy (Panitumumab). Case Report: The clinical case presented here refers to a 68-year-old patient who had been diagnosed with adenocarcinoma of the recto sigmoid with pelvic recurrence three years after surgery. The patient had a severe co-morbidity: correlated B-type liver cirrhosis. First-line chemotherapy was begun with Oxaliplatin plus Capecitabine (CAPOXI) following a relapse, and this continued for six months (six cycles), when the treatment was interrupted because of the disease’s progression and hematological and gastrointestinal toxicity. Following an assessment of the K-ras, diagnosed as wild type, the patient was excluded from second-line chemotherapy treatment because of decompensated cirrhosis and the persistence of thrombocytopenia and leukopenia. The patient was put forward for biological treatment with an anti-EGFR monoclonal antibody (Panitumumab). Panitumumab was administered at a dosage of 6 mg/kg every 2 weeks for 17 months;the treatment was well tolerated, despite the cirrhosis, and the main toxicity was the skin rash. Conclusion: In patients with severe comorbidities such as cirrhosis of the liver and K-ras wild-type carcinomas, therapy with a monoclonal antibody such as Panitumumab is a treatment that is well tolerated, with few serious toxic side-effects;it also offers advantages in terms of survival and clinical benefits.
文摘The effect of endosulfan, a hexachlorinated pesticide, on growth, inorganic nitrogenous nutrient uptake (NO3-, NO2- and NH4+), change in pigmentation and glycogen content on wild type and chemically mutagenised cells of Synechococcus cedrorum was investigated. The pattern of response to pesticide stress in wild and mutant type was the same. Growth reappeared in both after a period of initial lag in presence of endosulfan. The duration of lag increased with increasing doses of pesticide. Paradoxically, however, the rate of uptake of NO-3, NO-2 and NH+4 pigment and glycogen content progressively increased with increasing doses. The difference in the adaptation response between wild and mutant types was observed only in the concentration of pesticide that could be tolerated; with the mutant tolerating 2.5 fold more.
基金supported by the National Natural Science Foundation of China (30900977)the Key Project 210111 of Chinese Ministry of Education and Natural Science Foundation Project of CQ CSTC (2009BB1310)
文摘The coat protein （CP） genes were cloned and sequenced from viral particles of 11 isolates of citrus tristeza virus （CTV） collected from wild citrus plants in China and 4 Chinese isolates from cultivated sweet orange and pummelo varieties, respectively. By analyzing and comparing the nucleotide and amino acid sequences of CP genes, the 11 wild CTV isolates were found over 92% identical with 4 Chinese CTV isolates and 21 exotic CTV isolates from cultivated citrus. From 91 to 100% of the CTV CP gene sequences in wild type citrus plants were generally well conserved. Genetic evolution analysis indicated that the GC% of the CP gene was less than AT%, and more transition were found in the CP genes than transversion with the transition/transversion ratio ranging from 6.3 to 7.0 among species. The substitution frequency was the highest at the third codon, followed by the first and second codon. The ratio of non-synonymous mutations （du） to synonymous mutations （ds） was far lower than 1, suggesting that the CP gene might have experienced purifying selection in the evolution. Phylogenetic analysis revealed that the 11 CTV isolates in Chinese wild type citrus belonged to different phylogenetic clusters, and shared higher homology and closer relationships with other cultivated citrus CTV isolates from different countries, which indicated complicated genetic relationships among the CTV isolates. In addition, CTV isolates with similar biological characteristics usually located into the same clusters. Therefore, the conclusion was drawn that pathogenicity was critical to evolution and origin of CTV.
文摘More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but second in mortality.More than half of the patients are in advanced stages at diagnosis.Treatment options are complex because of the heterogeneity of the patient population,including different molecular subtypes.Treatments have included conventional fluorouracil-based chemotherapy,targeted therapy,immunotherapy,etc.In recent years,with the development of genetic testing technology,more and more targeted drugs have been applied to the treatment of CRC,which has further prolonged the survival of metastatic CRC patients.
文摘BACKGROUND Metastatic colorectal cancer(mCRC)treatment has been evolving and increasingly driven by tumor biology and gene expression analysis.Rechallenge with epidermal growth factor receptor(EGFR)inhibitors(anti-EGFR)represents a promising strategy for patients with RAS wild-type(RAS-wt)mCRC and circulating tumor DNA has emerged as a potential selection strategy.Herein,we report the case of a RAS-wt mCRC patient who had a successful response to cetuximab rechallenge.CASE SUMMARY Our patient was diagnosed with stage IV RAS-wt,microsatellite-stable rectosigmoid junction adenocarcinoma.He was started on first-line treatment with FOLFIRI and cetuximab and achieved partial response,allowing for a left hepatectomy(R0),followed by post-operative chemotherapy and an anterior resection;progression-free survival(PFS)of 16 months was obtained.Due to hepatic and nodal relapse,second-line treatment with FOLFOX and bevacizumab was started with partial response;metastasectomy was performed(R0),achieving a PFS of 11 months.After a 15 months anti-EGFR-free interval,FOLFIRI and cetuximab were reintroduced upon disease progression,again with partial response and a PFS of 16 months.Following extensive hepatic relapse,cetuximab was reintroduced and a marked clinical and analytical improvement was seen,after only one cycle.RASwt status was confirmed on circulating tumor DNA.The patient’s overall survival exceeded 5 years.CONCLUSION Our case provides real-world data to support cetuximab rechallenge in later lines of RAS-wt mCRC treatment.
