LYAR promotes colorectal cancer cell mobility by activating galectin-1 expression

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. However, the molecular mechanisms of CRC pathogenesis are not fully understood. In this study, we report the characterization of LYAR (Ly-1 antibody reactive clone) as a key regulator of the migration and invasion of human CRC cells. Immunohistochemistry analysis demonstrated that LYAR is expressed at a higher level in metastatic CRC tissues. We found that LYAR promoted the migratory and invasive capabilities of CRC cells. Gene expression profile analysis of CRC cells showed that LGALS1, which encodes the galectin-1 protein, was a potential target of LYAR. The ChIP assay and gene reporter assays indicated that LYAR directly bound to the LGALS1 promoter. The ectopic expression of galectin-1 partially restored the mobile potential of LYAR knocked-down cells, which suggests that galectin-1 contributed to the LYAR-promoted cell migration and invasion of CRC cells. Thus, this study revealed a novel mechanism by which the transcription factor LYAR may promote tumor cell migration and invasion by upregulating galectin-1 gene expression in CRC.

Abstract 4929: UbcH10 may represent a potential marker of gastric carcinoma

Gastric cancer is a fatal disease with limited early diagnostic methods available. There is an urgent need to find more effective targets for early diagnosis and therapeutics. UbcH10 is an ubiquitin-conjugating enzyme with a high expression reported in some cancers. Several gastric tumor cell lines with high or low expression of UbcH10 were exploited to study the role of UbcH10 in gastric cancer. Knocking down of UbcH10 expression using siRNA in high expressing gastric cancer cell lines resulted in reduced proliferation, increased cisplatin-induced apoptosis and reduced serum-induced ERK, Akt and p38 phosphorylation signaling. In agreement, overexpression of UbcH10 expression in low-expression gastric cancer cell lines led to enhanced cell proliferation, resistance to cisplatin-induced apoptosis. Most importantly, IHC analyses showed that the UbcH10 protein expressed at a high level in patient gastric cancer tissues, but not in adjacent mesenchyme tissues. These data suggest that UbcH10 may promote gastric cancer growth and can serve as a biomarker for diagnosis or target for new therapeutics in gastric cancer.

Citation Format: Mengxuan Yang, Yingying Qu, Gang Hu, Shiwei Tu, RL Shi, XB Wu, ZQ Hu, QM Zhang, SQ Liu, GF Pan, Ziping Zhang, He Zhou. UbcH10 may represent a potential marker of gastric carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4929.

[Epidemiological analysis of hospitalized patients with femoral neck fracture in a first-class hospital of Beijing]

OBJECTIVE

To analyze the clinical parameters of the patients with femoral neck fracture such as general condition, therapy method, hospitalized expense so as to provide more effective management plan for the clinical work.

METHODS

The patients with femoral neck fracture above 50 years who received in-patient treatment from 2008 January to 2012 December were admitted into this study. We collected and analyzed the information, such as age, chronic medical disease, therapy method, hospitalized duration and expense and so on.

RESULTS

There were 1 794 femoral neck fracture patients above 50 years (male/female=1/2.06) in our hospital in recent 5 years and the annual average rate of increase was 7.3%. The average age of the patients was (69.9±10.7) years and the annual average rate of increase was 0.6%. The chronic medical disease diagnosis ratio was 55.0%. The average waiting time for operation was (6.8±4.2) days and the average hospitalized duration was (12.9±4.9) days which showed downward trend in recent years. The most popular operations were cannulated screw internal fixation (41.8%) and artificial femoral head replacement (34.1%). In the study, 146 cases (7.9%) received nonsurgical treatment which showed downward trend. The average hospitalized expense was (35 075.7±11 343.2) yuan which showed no obvious change in recent years. The cost for the females was more than that for the males. The expense for hemiarthroplasty and total hip arthroplasty increased while that for cannulated screw internal fixation decreased gradually.

CONCLUSION

The cannulated screw internal fixation and artificial femoral head replacement were the most important operations for the patients with femoral neck fracture. The number and the average age of the patients were on the rise while the expense showed no obvious change in recent years.

[Anterior dislocation of the fibula resulting from surgical malreduction: a case report]

Ankle joint fracture is one of the most common types of fracture. There are many researches on the injury mechanism, treatment principles and surgical techniques. A type of injury which combines posterior dislocation of fibula, known as the Bosworth injury, is relatively rare. In 1947, Bosworth first described this type of injury as an unusual ankle fracture dislocation with fixed posterior fracture dislocation of the distal part of the fibula. In this type of fracture, the proximal fibular shaft fragment locks behind the tibialis posterior tubercle. This rare ankle fracture variant is often not recognized in initial radiographs and requires a computed tomographic (CT) scan for verification. But there are already many reports, discussing the injury mechanism, treatment principles and surgical techniques. However, there are few reports of anterior dislocation of the fibula, caused by either injury or surgery. The mechanism of the injury is still not clear. This article reports a case of anterior dislocation of the fibula. We report a patient with left ankle open fracture (Lauge-Hansen pronation-external rotation stage III, Gustilo IIIA). Open reduction and internal fixation was done in the initial surgery, but ended up with poor reduction, resulting in fibula anterior dislocation, anterior dislocation of talus and tibia fibular dislocation. The fibula was dislocated anteriorly of the tibia, which rarely happened. The patient suffered severe ankle joint dysfunction. The second operation took out the original internal fixation, reduced the fracture, and reset the internal fixation. The function of ankle joint was improved obviously after operation. But because of the initial injury and the two operations, the soft tissue around the fracture was greatly damaged. 6 months after the second operation, and the fracture still not healed, so the bone graft was carried out in the third surgery. Two months after the third surgery, the function of the ankle was significantly better than before, but the fracture healing was poor, which needed further review. Through this case, we understand the rare type of ankle fracture with anterior dislocation of the fibula, and recognize that the timing and quality of initial surgery has a great impact on the patient's prognosis and rehabilitation period.

Cloning and sequence analysis of the coding sequence of β-actin cDNA from the Chinese alligator and suitable internal reference primers from the β-actin gene

β-Actin is an essential component of the cytoskeleton and is stably expressed in various tissues of animals, thus, it is commonly used as an internal reference for gene expression studies. In this study, a 1731-bp fragment of β-actin cDNA from Alligator sinensis was obtained using the homology cloning technique. Sequence analysis showed that this fragment contained the complete coding sequence of the β-actin gene (1128 bp), encoding 375 amino acids. The amino acid sequence of β-actin is highly conserved and its nucleotide sequence is slightly variable. Multiple alignment analyses showed that the nucleotide sequence of the β-actin gene from A. sinensis is very similar to sequences from birds, with 94-95% identity. Ten pairs of primers with different product sizes and different annealing temperatures were screened by PCR amplification, agarose gel electrophoresis, and DNA sequencing, and could be used as internal reference primers in gene expression studies. This study expands our knowledge of β-actin gene phylogenetic evolution and provides a basis for quantitative gene expression studies in A. sinensis.

[Management of pelvic injury associated with complete anterior sacroiliac joint dislocation]

OBJECTIVE

To investigate the management of pelvic injury associated with complete anterior sacroiliac joint dislocation.

METHODS

In the study, 6 cases of pelvic injury associated with complete anterior sacroiliac joint dislocation treated in Beijing Jishuitan Hospital from February 2008 to June 2014 were analyzed. We described the history and severity of injury, emergency treatment, and fracture radiology. In all the cases, the surgical treatment and postoperative functional exercise were performed. We followed up all the cases on an average of 1.6 years, assessed the postoperative recovery and summed up the treatment experience.

RESULTS

All the 6 patients with fractures recovered without infection and nerve symptoms after surgery. Their X-rays showed good reduction of sacroiliac joints. All the cases were followed up on an average of 1.6 years. Six months after surgery, the Majeed scores were perfect in 2 cases, good in 2, fair in 1, and poor in 1. The patients with poor scores suffered persistent pain, and decreased physical activity, and when walking long distances, they needed a walking stick. The 2 patients with low scores could not resume the original work.

CONCLUSION

Pelvic injury associated with complete anterior sacroiliac joint dislocation is a special type of the pelvic injury since the managements during the emergency phase are difficult.The surgery should be done as early as possible, and the anterior approach is available for the reduction and fixation.

[Pregnancy-related pelvic ring disease and its treatment]

Pregnancy-related pelvic ring disease brings great suffering to pregnant women, including the separation of the pubic symphysis and sacroiliac joint pain. Hormonal changes leading to ligamentous laxity is the main reason for Pregnancy-related pelvic ring disease. In normal pregnant cases, and the physiologic widening at the symphysis is about 3-7 mm. When the widening of the symphysis is more than 10 mm, it may lead to symptoms and need active treatment. Currently the diagnosis of the pubic symphysis separation is based on the clinical symptoms and signs. The treatment of acute pubic symphysis separation bases on conservative therapy, includes bed rest and physical therapy. But when the widening of the symphysis is more than 4 cm, the surgery intervention may be a good treatment. If the conservative treatment is not obviously effective, the surgery consists of plate fixation in the pubic symphysis and sacroiliac screw fixation. Other indications for the surgical intervention include inadequate reduction, recurrent diastasis, intractable symptoms, and open rupture.

The clinical significance and risk factors of solitary lymph node metastasis in gastric cancer

AIMS

To assess the clinical significance and risk factors of solitary lymph node metastasis (SLM) in gastric carcinoma and establish a more accurate method to evaluate the possibility of lymph node metastasis (LM).

METHODS

A total of 385 patients with gastric carcinoma who underwent D2 lymphadenectomy at the Cancer Center of Sun Yat-Sen University were included in this research. Then we used a group of data from Sun Yat-sen University Gastrointestinal Hospital (SYSUGIH) to validate the accuracy of our developed method. The χ2 test, Kaplan-Meier analysis, log-rank test, COX model, and discriminate analysis were used to analyze the data with SPSS13.0.

RESULTS

We found that the LM number and pathological T staging were independent prognostic risk factors. CEA grading, LN status by CT, and T staging by CT were independent risk factors for LM in gastric carcinoma. In addition, we developed the equation Y = -5.0 + X1 + 1.8X3 + 0.7X4 (X1 = CEA grading, X3 = LN status by CT, X4 = T staging by CT) to evaluate the situation of LM. The data from SYSUGIH shows this equation has a better accuracy compared with CT.

CONCLUSIONS

SLM is an independent risk factor in gastric cancer. And there was no survival difference between the skip metastasis group and the other SLM group (P = 0.659). It is inappropriate for the patient with SLM doing a standard D2 lymphadenectomy, due to the fact that LM rarely occurs in the splenic artery, splenic hilum. The risk factors for LM include CEA grading, LN status by CT, and T staging by CT. And we can use Y = -5.0 + X1 + 1.8X3 + 0.7X4 (X1, CEA grading, X3 = LN status by CT, X4 = T staging by CT, the critical value is 0.3) to estimate the possibility of LM, which has a better accuracy compared with CT.

MCPH1 Protein Expression in Normal and Neoplastic Lung Tissues

Lung cancer is the most common cause of cancer-related death in the world. The main types are small-cell lung carcinoma (SCLC) and non-small-cell lung carcinoma (NSCLC), the latter including squamous cell carcinoma (SCC), adenocarcinoma and large cell carcinoma. NSCLCs account for about 80% of all lung cancer cases. Microcephalin (MCPH1), also called BRIT1 (BRCT-repeat inhibitor of hTERT expression), plays an important role in the maintenance of genomic stability. Recently, several studies have provided evidence that the expression of MCPH1 gene is decreased in several different types of human cancers. We evaluated the expression of protein MCPH1 in 188 lung cancer and 20 normal lung tissues by immunohistochemistry. Positive MCPH1 staining was found in all normal lung samples and only some cancerous tissues. MCPH1-positive cells were significantly lower in lung carcinoma compared with normal tissues. Furthermore, we firstly found that MCPH1 expression in lung adenocarcinoma is higher than its expression in squamous cell carcinoma. Change in MCPH1 protein expression may be associated with lung tumorigenesis and may be a useful biomarker for identification of pathological types of lung cancer.

Pancreatic Insulinoma Misdiagnosed as Epilepsy for Eight Years: A Case Report and Literature Review

A 58-year-old Chinese man presented with intermittent seizure episodes after being misdiagnosed with epilepsy for eight years. MRI revealed an abnormally strong signal in the distal pancreas. The patient was subsequently diagnosed with pancreatic insulinoma based on the histological findings, and his symptoms improved following surgical removal of the tumor. The appearance of unusual manifestations of insulinoma makes it difficult to diagnose the condition. This disorder should be included in the differential diagnosis of epilepsy and mental illness.

[Bone marrow-derived dendritic cells rather than spleen-derived dendritic cells can generate regulatory T cells]

There are many evidences that dendritic cells (DC) can establish and maintain immunological tolerance through inducing the differentiation of regulatory T cells Treg. This study was purposed to explore the possibility to gene-rate Treg from bone marrow-derived DC (BM-DC) or spleen-derived DC (spDC) generated CD4(+) CD25(+) FOXP3(+) Treg by induction. Bone marrow immature DC (imDC) induced from bone marrow precursor cells of C57BL/6 mice by GM-CSF and IL-4; after culture for 6 day, imDC were stimulated by LPS for additional 16 hours and the mature DC (mDC) have been got; the spDC were collected from spleen of C57BL/6 mice by MACS. Co-culturing fresh BALB/c mouse CD4(+) T cells with these three sorts of DC above mentioned respectively was performed to generate CD4(+) CD25(+) FOXP3(+) Treg. The expression of FOXP3 in CD4(+) T cells was detected by flow cytometry, and the capacity of different DC generated CD4(+) CD25(+) FOXP3(+) Treg was evaluated. The results showed that stimulated by C57BL/6 immature or mature DC, the positive rate of FOXP3 in BALB/c CD4(+) T cells increased from (8.57 ± 1.14)% to (15.80 ± 1.35)%, (17.93 ± 1.45)% respectively (P < 0.01); while stimulated by spDC, the positive rate of FOXP3 in BALB/c CD4(+) T cells decreased from (8.57 ± 1.14)% to (3.95 ± 0.79)% (P < 0.05). It is concluded that the BM-DC but not spDC can generate Treg from CD4(+) T cells, BM-DC may mediate immune tolerance rather than the immune response.

Development and characterization of microsatellite markers for the endangered Chinese yew Taxus chinensis var. mairei (Taxaceae)

We isolated and characterized 11 microsatellite loci for the Chinese yew, Taxus chinensis var. mairei, an endangered tree species in China, by constructing a (CA)(12)-enriched library. The number of alleles per locus ranged from 5 to 10. The observed heterozygosities ranged from 0.2500 to 0.8333 and the expected heterozygosities ranged from 0.5196 to 0.8680. No significant linkage disequilibrium was detected at these loci. However, four loci significantly deviated from Hardy-Weinberg equilibrium. The null alleles were found to be present at locus Tach9 and locus Tach11 by the Micro-checker test (P < 0.001). These polymorphic loci could be employed in research of gene flow and spatial genetic patterns of T. chinensis var. mairei.

Empirical assessment of state-and-transition models with a long-term vegetation record from the Sonoran Desert

Resilience-based frameworks, including state-and-transition models (STM), are being increasingly called upon to inform policy and guide ecosystem management, particularly in rangelands. Yet, multiple challenges impede their effective implementation: (1) paucity of empirical tests of resilience concepts, such as alternative states and thresholds, and (2) heavy reliance on expert models, which are seldom tested against empirical data. We developed an analytical protocol to identify unique plant communities and their transitions, and applied it to a long-term vegetation record from the Sonoran Desert (1953-2009). We assessed whether empirical trends were consistent with resilience concepts, and evaluated how they may inform the construction and interpretation of expert STMs. Seven statistically distinct plant communities were identified based on the cover of 22 plant species in 68 permanent transects. We recorded 253 instances of community transitions, associated with changes in species composition between successive samplings. Expectedly, transitions were more frequent among proximate communities with similar species pools than among distant communities. But unexpectedly, communities and transitions were not strongly constrained by soil type and topography. Only 18 transitions featured disproportionately large compositional turnover (species dissimilarity ranged between 0.54 and 0.68), and these were closely associated with communities that were dominated by the common shrub (burroweed, Haplopappus tenuisecta); indicating that only some, and not all, communities may be prone to large compositional change. Temporal dynamics in individual transects illustrated four general trajectories: stability, nondirectional drift, reversibility, and directional shifts that were not reversed even after 2-3 decades. The frequency of transitions and the accompanying species dissimilarity were both positively correlated with fluctuation in precipitation, indicating that climatic drivers require more attention in STMs. Many features of the expert models, including the number of communities and participant species, were consistent with empirical trends, but expert models underrepresented recent increases in cacti while overemphasizing the introduced Lehmann's lovegrass (Eragrostis lehmanniana). Quantification of communities and transitions within long-term vegetation records presents several quantitative metrics such as transition frequency, magnitude of accompanying compositional change, presence of unidirectional trajectories, and lack of reversibility within various timescales, which can clarify resilience concepts and inform the construction and interpretation of STMs.

Tissue metabolomic fingerprinting reveals metabolic disorders associated with human gastric cancer morbidity

The principal way to improve the outcome of gastric cancer (GC) is to predict carcinogenesis and metastasis at an early stage. The aims of the present study were to test the hypothesis that distinct metabolic profiles are reflected in GC tissues and to further explore potential biomarkers for GC diagnosis. Gas chromatography/mass spectrometry (GC/MS) was utilized to analyze tissue metabolites from 30 GC patients. A diagnostic model for GC was constructed using orthogonal partial least squares discriminant analysis (OPLS-DA), and the metabolomic data were analyzed using the non-parametric Wilcoxon rank sum test to identify the metabolic tissue biomarkers for GC. Over 100 signals were routinely detected in one single total ion current (TIC) chromatogram, and the OPLS-DA model generated from the metabolic profile of the tissues adequately discriminated the GC tissues from the normal mucosae. Among the low-molecular-weight endogenous metabolites, a total of 41 compounds, such as amino acids, organic acids, carbohydrates, fatty acids and steroids, were detected, and 15 differential metabolites were identified with significant difference (p<0.05). A total of 20 variables were noted which contributed to a great extent in the discriminating OPLS-DA model (VIP value >1.0), among which 12 metabolites were identified using both VIP values (VIP >1) and the Wilcoxon test (p<0.05). In conclusion, the identification of the metabolites associated with GC morbidity potentially revealed perturbations of glycolysis, fatty acid β-oxidation, cholesterol and amino acid metabolism. These results suggest that tissue metabolic profiles have great potential in detecting GC and may aid in understanding its underlying mechanisms.

[Detection of single-walled carbon nanotube bundles by tip-enhanced Raman spectroscopy]

Raman spectroscopy is a powerful technique in the characterization of carbon nanotubes (CNTs). However, this spectral method is subject to two obstacles. One is spatial resolution, namely the diffraction limits of light, and the other is its inherent small Raman cross section and weak signal. To resolve these problems, a new approach has been developed, denoted tip-enhanced Raman spectroscopy (TERS). TERS has been demonstrated to be a powerful spectroscopic and microscopic technique to characterize nanomaterial or nanostructures. Excited by a focused laser beam, an enhanced electric field is generated in the vicinity of a metallic tip because of the surface plasmon polariton (SPP) and lightening rod effect. Consequently, Raman signal from the sample area illuminated by the enhanced field nearby the tip is enhanced. At the same time, the topography is obtained in the nanometer scale. The exact corresponding relationship between the localized Raman and the topography makes the Raman identification at the nanometer scale to be feasible. In the present paper, based on an inverted microscope and a metallic AFM tip, a tip-enhanced Raman system was set up. The radius of the Au-coated metallic tip is about 30 nm. The 532 nm laser passes through a high numerical objective (NA0.95) from the bottom to illuminate the tip to excite the enhanced electric field. Corresponding with the AFM image, the tip-enhanced near-field Raman of a 100 nm diameter single-walled carbon nanotube (SWNT) bundles was obtained. The SWNTs were prepared by arc method. Furthermore, the near-field Raman of about 3 SWNTs of the bundles was received with the spatial resolution beyond the diffraction limit. Compared with the far-field Raman, the enhancement factor of the tip-enhanced Raman is more than 230. With the super-diffraction spatial resolution and the tip-enhanced Raman ability, tip-enhanced Raman spectroscopy will play an important role in the nano-material and nano-structure characterization.

Correlation of APC MCR mutation with colorectal neoplasms

AIM: To explore relationship of codon 1493, 1367 and 1328 mutations in mutation cluster region (MCR) of exon 15 of Adenomatous polyposis coli (APC) gene in cases of colorectal neoplasm with the family history.

METHODS: The specimens were prepared for DNA extraction from 21 colorectal adenoma specimens, 16 colorectal carcinoma, 20 healthy germline groups with positive familial history and 8 healthy germline groups without family history. Then MCR of APC gene exon 15 were specifically amplified and sequenced by ABI3100 Genetic Analyzer, and the codon mutations were statistically analyzed among the 4 groups and variation genotypes, and then tested with Chi-square.

RESULTS: The codon mutations of APC MCR from total samples were three variations: 1493(ACG>ACA), 63/69(91.3%); 1367(CAG>TAG), 1/69(1.4%) and 1328(CAG>TAG), 5/69(7.2%)Four genotypes such as 4478 (G→A), 4478 (G/A), 4096 (C/T) and 3979 (C/T) were found out. Significant differences (P < 0.05) were noted between the adenoma group and non-family history group on the analysis of 4478 (G→A) and (G/A), also noted between family history group and no family history group on the analysis of 4478 (G→A). The significant differences (P < 0.05) in pathogenic mutant phenotypes were involved between 4478 (G→A) with 4478 (G/A), 4096 (C/T) and 3979 (C/T), respectively, also between 4478 (G/A) with 4096 (C/T) and 3979 (C/T), but not between 4096 (C/T) and 3979 (C/T).

CONCLUSION: The most frequently present 4478 (G→A) of 1493 (ACG>ACA) is the phenotype of positive history group and adenoma group. In researches, APC MCR codon 1367 and 1328 genotyping are significantly present only in somatic cells of the colorectal cancergenetic phenotypes.

Assessing the influence of field- and GIS-based inquiry on student attitude and conceptual knowledge in an undergraduate ecology lab

Combining field experience with use of information technology has the potential to create a problem-based learning environment that engages learners in authentic scientific inquiry. This study, conducted over a 2-yr period, determined differences in attitudes and conceptual knowledge between students in a field lab and students with combined field and geographic information systems (GIS) experience. All students used radio-telemetry equipment to locate fox squirrels, while one group of students was provided an additional data set in a GIS to visualize and quantify squirrel locations. Pre/postsurveys and tests revealed that attitudes improved in year 1 for both groups of students, but differences were minimal between groups. Attitudes generally declined in year 2 due to a change in the authenticity of the field experience; however, attitudes for students that used GIS declined less than those with field experience only. Conceptual knowledge also increased for both groups in both years. The field-based nature of this lab likely had a greater influence on student attitude and conceptual knowledge than did the use of GIS. Although significant differences were limited, GIS did not negatively impact student attitude or conceptual knowledge but potentially provided other benefits to learners.

[Application of near-field Raman spectroscopy to nano-structure characterization]

Near-field Raman spectroscopy is a novel technology in the near-field optics, and attracts much attention of scientists because of the realization of spectral characterization of nano-structure. The technical advantage of Raman spectroscopy is described in the present review. The principle and practical technical scheme of near-field Raman spectroscopy systems are introduced. Several applications of near-field Raman spectroscopy are mentioned in detail, including carbon nanotube characterization, biological specimen imaging, thermoelectric crystal characterization, dye single molecule detection etc., revealing a broad prospect of the development of near-field Raman spectroscopy in various scientific research fields.

[Transfection efficiency of adenoviral vector AD5/F35 to malignant hematopoietic cells of different origins]

This study was aimed to investigate the transfection efficiency of adenoviral vector AD5/F35 to hematopoietic malignant cells lines of various origins and AD5/F35 cytotoxicity. The hematologic malignant cell lines of various origins were transfected by AD5/F35-EGFP at different multiple of infection (MOI) and AD5-EGFP was used as control; the proportion of fluorescence positive cells was detected by flow cytometry; the killing effect of virus on infective target cells was assayed by MTT and observed by fluorescence microscopy. The results showed that the transfection efficiency of AD5/F35 vector to cell line of myeloid origin was > 99% at MOI = 30, the transfective efficiency of AD5 vector was 26.4% at MOI = 1,000; the transfection efficiency of AD5/F35 vector and AD5 vector to cell line of B cell origin were 11.7% and 5.7%, respectively, at MOI = 1,000. AD5/F35 and AD5 vectors could not effectively transfect cells of T cell origin, no fluorescence positive cells were detected at MOI = 1,000; no significant killing effect of AD5/F35 vector on infective target cells was observed at MOI = 1,000. It is concluded that AD5/F35 vector infection has definite selectivity to hematologic malignant cells of various origin, the infection ability of AD5/F35 vector to cells of myeloid origin is stronger than that to cells of B cell origin, the cytotoxicity of AD5/F35 vector to infective target cells is small. The AD5/F35 vector is preferable to AD5 vector in respect of infection ability and offers good prospects of application in gene therapy for myeloid leukemia cells as target cells.

[Construction of rAAV2-GPIIb/IIIa vector and test of its expression and function in vitro]

This study was aimed to explore the possibility of rAAV2 vector-mediating gene therapy for Glanzmann' s thrombasthenia. The rAAV2-GPIIb/IIIa vector was constructed. The GPIIb/IIIa gene expression in mammal cell were examined by different methods, such as: detection of mRNA expression in BHK-21 cells after 24 hours of infection (MOI = 1 x 10(5) v.g/cell) was performed by RT-PCR; the relation between MOI and quantity of GPII6/IIIa gene expression was detected by FACS after 48 hours of infection; GPIIb/IIIa protein expression in BHK-21 cells after 48 hours of infection (MOI = 10(5) v x g/cell) was assayed by Western blot, GPIIb/IIIa protein expression on cell surface was detected by immunofluorescence, and the biological function of expressing product was determined by PAC-1 conjunct experiments. The results showed that GPIIb/IIIa gene expression in mRNA level could be detected in BHK-21 cells after 24 hours of infection at MOI = 1 x 10(5) v x g/cell and the GPIIb/IIIa gene expression in protein level could be detected in BHK-21 cells after 48 hours of infection at MOI = 1 x 10(5) v x g/cell. In certain range, quantity of GPIIb/IIIa gene expression increased with MOI, but overdose of MOI decreased quantity of GPIIb/IIIa gene expression. Activated product of GPIIb/IIIa gene expression could combined with PAC-I, and possesed normal biological function. In conclusion, rAAV2 vactor can effectively mediate GPIIb and GPIIIa gene expressing in mammal cells, and the products of these genes exhibit biological function. This result may provide a basis for application of rAAV2 vector in Glanzmann's thrombasthenia gene therapy in furture.

C-terminus mutations of Acremonium chrysogenum deacetoxy/deacetylcephalosporin C synthase with improved activity toward penicillin analogs

Deacetoxy/deacetylcephalosporin C synthase (acDAOC/DACS) from Acremonium chrysogenum is a bifunctional enzyme that catalyzes both the ring-expansion of penicillin N to deacetoxycephalosporin C (DAOC) and the hydroxylation of the latter to deacetylcephalosporin C (DAC). Three residues N305, R307 and R308 located in close proximity to the C-terminus of acDAOC/DACS were each mutated to leucine. The N305L and R308L mutant acDAOC/DACSs showed significant improvement in their ability to convert penicillin analogs. R308 was identified for the first time as a critical residue for DAOC/DACS activity. Kinetic analyses of purified R308L enzyme indicated its improved catalytic efficiency is due to combined improvements of K(m) and k(cat). Comparative modeling of acDAOC/DACS supports the involvement of R308 in the formation of substrate-binding pocket.