Clinical significance of S100A2 expression in gastric cancer.

Gastric carcinoma (GC) is one of the most common malignancies worldwide. To identify the candidate carcinoma-related biomarker in GC, comparative proteome technique was performed in resected GC tissues and matched adjacent non-cancerous gastric tissues (ANGT). As a result, S100A2 was successfully identified to be down-regulated significantly in GC compared with ANGT. Western blot analysis validated decreased expression of S100A2, and its expression level was related with the degree of tumor differentiation and status of lymph node metastasis in GC. Furthermore, immunohistochemistry analysis showed S100A2 down-expression was significantly associated with poor differentiation (P < 0.05), advanced depth of invasion (P < 0.05) and lymph node metastasis (P < 0.05) in GC. Kaplan-Meier curves showed that the relapse-free probability and the overall survival rate were significantly decreased with S100A2 expression decreasing (P < 0.05). Cox regression analysis indicated S100A2 down-expression was a negative independent prognostic biomarker for GC. A supplement of S100A2 protein by S100A2 expression vector significantly decreased the number of invaded cancer cells MGC-803. However, knockdown of S100A2 expression by siRNA interference compromised the invasion ability of MGC-803 cells. Moreover, S100A2 negatively regulated MEK/ERK signaling pathway, and activation of this signaling pathway by S100A2 down-regulation increased in vitro invasion of MGC-803 cells. In conclusion, this study demonstrated the clinical significance of S100A2 expression in GC, and loss of S100A2 expression contributes to GC development and progression. Therefore, the determination of S100A2 expression levels contributes to predict the outcome of GC patients.

MiR-15a-16 represses Cripto and inhibits NSCLC cell progression.

MicroRNAs (miRNAs) are small noncoding RNAs that have important roles in cancer. The altered expressions of miRNAs and their target genes are frequently detected in various tumors. In this study, downregulation of miR-15a-16 in nonsmall cell lung cancer (NSCLC) was found to be inversely correlated with Cripto. Results from the Luciferase reporter assay and Western blot analysis also confirmed that Cripto is a direct target of miR-15a-16. In addition, transfection of miR-15a-16 expression plasmid inhibited the invasion ability and promoted the apoptosis of NCI-H23 and NCI-H358 cells. Moreover, miR-15a-16 overexpression suppressed tumor growth in vivo. These findings clearly suggest that the downregulation of miR-15a-16 with Cripto amplification may be involved in the development of NSCLC.

Collagen/heparin sulfate scaffold combined with mesenchymal stem cells treatment for canines with spinal cord injury: A pilot feasibility study.

BACKGROUND: Due to endogenous neuronal deficiency and glial scar formation, spinal cord injury (SCI) often leads to irreversible neurological loss. Accumulating evidence has shown that a suitable scaffold has important value for promoting nerve regeneration after SCI. Collagen/heparin sulfate scaffold (CHSS) has shown effect for guiding axonal regeneration and decreasing glial scar deposition after SCI. The current research aimed to evaluate the utility of the CHSSs adsorbed with mesenchymal stem cells (MSCs) on nerve regeneration, and functional recovery after acute complete SCI. METHODS: CHSSs were prepared, and evaluated for biocompatibility. The CHSSs adsorbed with MSCs were transplanted into these canines with complete SCI. RESULTS: We observed that MSCs had good biocompatibility with CHSSs. In complete transverse SCI models, the implantation of CHSS co-cultured with MSCs exhibited significant improvement in locomotion, motor evoked potential, magnetic resonance imaging, diffusion tensor imaging, and urodynamic parameters. Meanwhile, nerve fibers were markedly improved in the CHSS adsorbed with MSCs group. Moreover, we observed that the implantation of CHSS combined with MSCs modulated inflammatory cytokine levels. CONCLUSIONS: The results preliminarily demonstrated that the transplantation of MSCs on a CHSS could improve the recovery of motor function after SCI. Thus, implanting the MSCs-laden CHSS is a promising combinatorial therapy for treatment in acute SCI.

Recovery of motor function in rats with complete spinal cord injury following implantation of collagen/silk fibroin scaffold combined with human umbilical cord-mesenchymal stem cells.

OBJECTIVE: This study aimed to assess the effect of the collagen/silk fibroin scaffolds seeded with human umbilical cord-mesenchymal stem cells on functional recovery after acute complete spinal cord injury. METHODS: The fibroin and collagen were mixed (mass ratio, 3:7), and the composite scaffolds were produced. Forty rats were randomly divided into the Sham group (without spinal cord injury), spinal cord injury group (spinal cord transection without any implantation), collagen/silk fibroin scaffolds group (spinal cord transection with implantation of the collagen/silk fibroin scaffolds), and collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group (spinal cord transection with the implantation of the collagen/silk fibroin scaffolds co-cultured with human umbilical cord-mesenchymal stem cells). Motor evoked potential, Basso-Beattie-Bresnahan scale, modified Bielschowsky's silver staining, and immunofluorescence staining were performed. RESULTS: The BBB scores in the collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group were significantly higher than those in the spinal cord injury and collagen/silk fibroin scaffolds groups (p<0.05 or p<0.01). The amplitude and latency were markedly improved in the collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group compared with the spinal cord injury and collagen/silk fibroin scaffolds groups (p<0.05 or p<0.01). Meanwhile, compared to the spinal cord injury and collagen/silk fibroin scaffolds groups, more neurofilament positive nerve fiber ensheathed by myelin basic protein positive structure at the injury site were observed in the collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group (p<0.01, p<0.05). The results of Bielschowsky's silver staining indicated more nerve fibers was observed at the lesion site in the collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group compared with the spinal cord injury and collagen/silk fibroin scaffolds groups (p<0.01, p< 0.05). CONCLUSION: The results demonstrated that the transplantation of human umbilical cord-mesenchymal stem cells on a collagen/silk fibroin scaffolds could promote nerve regeneration, and recovery of neurological function after acute spinal cord injury.

Quantitative proteomic analysis of differential proteins in the stroma of nasopharyngeal carcinoma and normal nasopharyngeal epithelial tissue.

The importance of stromal cells and the factors that they expressed during cancer initiation and progression have been highlighted by recent literature. To identify the stromal proteins involved in nasopharyngeal carcinoma (NPC) carcinogenesis, we assessed differences in protein expression of the stroma from NPC and normal nasopharyngeal epithelium tissues (NNET) using a quantitative proteomic approach combined with laser capture microdissection (LCM). LCM was performed to purify stromal cells from the NPC and NNET, respectively. The differential proteins between the pooled microdissected tumor and normal stroma were analyzed by two-dimensional difference gel electrophoresis (2D-DIGE) combined with mass spectrometry (MS). Twenty differential proteins were identified, and the expression and location of two differential proteins (L-plastin and S100A9) were further confirmed by Western blotting and immunohistochemical analysis. Our results will be helpful to study the role of stroma in the NPC carcinogenesis, as well as discover the interaction between NPC cells and their surrounding microenvironment.

miRNA array analysis of plasma miRNA alterations in rats exposed to a high altitude hypoxic environment.

In the present study, the microRNA (miRNA) expression profiles of rats exposed to high altitude hypoxia and normal conditions were obtained from miRNA array analysis. Bioinformatics analyses, including the use of the Gene Oncology and Kyoto Encyclopedia of Genes and Genomes databases, were used to identify the genes and pathways, which were specifically associated with high altitude hypoxic environment­associated miRNAs. A total of 26 miRNAs were differentially expressed in the two groups, comprising six upregulated and 20 downregulated miRNAs. In the present study, a novel pattern of upregulated miRNAs and their associated pathways were constructed, including proteoglycans in cancer, spliceosome, gluamatergic synapse, glycolysis/gluconeogenesis, Foxo, cGMP­PKG and p53 signaling pathways, which may provide novel targets for diagnosing and understanding the mechanism of high altitude hypoxia­induced disease.

Saikosaponin a increases interleukin-10 expression and inhibits scar formation after sciatic nerve injury.

Nerve scarring after peripheral nerve injury can severely hamper nerve regeneration and functional recovery. Further, the anti-inflammatory cytokine, interleukin-10, can inhibit nerve scar formation. Saikosaponin a (SSa) is a monomer molecule extracted from the Chinese medicine, Bupleurum. SSa can exert anti-inflammatory effects in spinal cord injury and traumatic brain injury. However, it has not been shown whether SSa can play a role in peripheral nerve injury. In this study, rats were randomly assigned to three groups. In the sham group, the left sciatic nerve was directly sutured after exposure. In the sciatic nerve injury (SNI) + SSa and SNI groups, the left sciatic nerve was sutured and continuously injected daily with SSa (10 mg/kg) or an equivalent volume of saline for 7 days. Enzyme linked immunosorbent assay results demonstrated that at 7 days after injury, interleukin-10 level was considerably higher in the SNI + SSa group than in the SNI group. Masson staining and western blot assay demonstrated that at 8 weeks after injury, type I and III collagen content was lower and nerve scar formation was visibly less in the SNI + SSa group compared with the SNI group. Simultaneously, sciatic functional index and nerve conduction velocity were improved in the SNI + SSa group compared with the SNI group. These results confirm that SSa can increase the expression of the anti-inflammatory factor, interleukin-10, and reduce nerve scar formation to promote functional recovery of injured sciatic nerve.

Transcriptome-derived stromal and immune scores infer clinical outcomes of patients with cancer.

The stromal and immune cells that form the tumor microenvironment serve a key role in the aggressiveness of tumors. Current tumor-centric interpretations of cancer transcriptome data ignore the roles of stromal and immune cells. The aim of the present study was to investigate the clinical utility of stromal and immune cells in tissue-based transcriptome data. The 'Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data' (ESTIMATE) algorithm was used to probe diverse cancer datasets and the fraction of stromal and immune cells in tumor tissues was scored. The association between the ESTIMATE scores and patient survival data was asessed; it was indicated that the two scores have implications for patient survival, metastasis and recurrence. Analysis of a colorectal cancer progression dataset revealed that decreased levels immune cells could serve an important role in cancer progression. The results of the present study indicated that trasncriptome-derived stromal and immune scores may be a useful indicator of cancer prognosis.

Exendin-4 inhibits high-altitude cerebral edema by protecting against neurobiological dysfunction.

The anti-inflammatory and antioxidant effects of exendin-4 (Ex-4) have been reported previously. However, whether (Ex-4) has anti-inflammatory and antioxidant effects on high-altitude cerebral edema (HACE) remains poorly understood. In this study, two rat models of HACE were established by placing rats in a hypoxic environment with a simulated altitude of either 6000- or 7000-m above sea level (MASL) for 72 hours. An altitude of 7000 MASL with 72-hours of hypoxia was found to be the optimized experimental paradigm for establishing HACE models. Then, in rats where a model of HACE was established by introducing them to a 7000 MASL environment with 72-hours of hypoxia treatment, 2, 10 and, 100 µg of Ex-4 was intraperitoneally administrated. The open field test and tail suspension test were used to test animal behavior. Routine methods were used to detect change in inflammatory cells. Hematoxylin-eosin staining was performed to determine pathological changes to brain tissue. Wet/dry weight ratios were used to measure brain water content. Evans blue leakage was used to determine blood-brain barrier integrity. Enzyme-linked immunosorbent assay (ELISA) was performed to measure markers of inflammation and oxidative stress including superoxide dismutase, glutathione, and malonaldehyde values, as well as interleukin-6, tumor necrosis factor-alpha, cyclic adenosine monophosphate levels in the brain tissue. Western blot analysis was performed to determine the levels of occludin, ZO-1, SOCS-3, vascular endothelial growth factor, EPAC1, nuclear factor-kappa B, and aquaporin-4. Our results demonstrate that Ex-4 preconditioning decreased brain water content, inhibited inflammation and oxidative stress, alleviated brain tissue injury, maintain blood-brain barrier integrity, and effectively improved motor function in rat models of HACE. These findings suggest that Ex-4 exhibits therapeutic potential in the treatment of HACE.

Augmented humoral and cellular immune responses induced by canine adenovirus type 1 DNA vaccine in BALB/c mice.

Infectious canine hepatitis (ICH) is caused by canine adenovirus type 1 (CAV-1), which severely harms infected animals. Vaccination provides an effective approach to preventing canine infectious diseases. With the objective of exploring a new vaccination strategy that may prevent or cure ICH, we constructed a DNA vaccine, pVAX1-CpG-Loop, and evaluated its immune efficacy. We found that vaccination of BALB/c mice with the DNA vaccine alone, or priming with DNA vaccine and boosting with the Loop protein, resulted in the following: (1) High-level specific antibody (IgG) against CAV-1 was induced; (2) T cell activation was elicited; and (3) neutralizing antibodies were detectable in immunized mice. Collectively, these data indicate that the availability of a DNA vaccine could prevent hepatitis contagiosa canis.

Annexin A3 Knockdown Suppresses Lung Adenocarcinoma.

Our previous study identified an elevated abundance of annexin A3 (Anxa3) as a novel prognostic biomarker of lung adenocarcinoma (LADC) through quantitative proteomics analysis. However, the biological functions of Anxa3 in LADC are not fully clear. In this study, in vitro and in vivo assays were performed to investigate the effects of Anxa3 downregulation on the growth, migration, invasion, metastasis, and signaling pathway activation of LADC cells. After Anxa3 downregulation, the growth of A549 and LTEP-a2 LADC cells was slowed and they showed decreased migration and invasion in vitro. Anxa3 knockdown significantly inhibited tumor formation by A549 cells in vivo; while many metastases were formed by control A549 cells, there were obvious reductions in the numbers of lung, liver, and brain metastases formed by Anxa3 knockdown in A549 cells. Furthermore, Anxa3 knockdown significantly decreased MMP-2 and N-cadherin expression and increased E-cadherin expression both in cell lines in vitro and in tumor nodules examined during in vivo tumorigenesis assays. Interestingly, Anxa3 downregulation reduced the phosphorylated levels of MEK and ERK. In summary, Anxa3 knockdown inhibited the growth, migration, invasion, and metastasis of LADC, decreased the activation of the MEK/ERK signaling pathway, and modulated the expression of MMP-2, E-cadherin, and N-cadherin.

Recovery of motor function in rats with complete spinal cord injury following implantation of collagen/silk fibroin scaffold combined with human umbilical cord-mesenchymal stem cells

SUMMARY OBJECTIVE: This study aimed to assess the effect of the collagen/silk fibroin scaffolds seeded with human umbilical cord-mesenchymal stem cells on functional recovery after acute complete spinal cord injury. METHODS: The fibroin and collagen were mixed (mass ratio, 3:7), and the composite scaffolds were produced. Forty rats were randomly divided into the Sham group (without spinal cord injury), spinal cord injury group (spinal cord transection without any implantation), collagen/silk fibroin scaffolds group (spinal cord transection with implantation of the collagen/silk fibroin scaffolds), and collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group (spinal cord transection with the implantation of the collagen/silk fibroin scaffolds co-cultured with human umbilical cord-mesenchymal stem cells). Motor evoked potential, Basso-Beattie-Bresnahan scale, modified Bielschowsky's silver staining, and immunofluorescence staining were performed. RESULTS: The BBB scores in the collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group were significantly higher than those in the spinal cord injury and collagen/silk fibroin scaffolds groups (p<0.05 or p<0.01). The amplitude and latency were markedly improved in the collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group compared with the spinal cord injury and collagen/silk fibroin scaffolds groups (p<0.05 or p<0.01). Meanwhile, compared to the spinal cord injury and collagen/silk fibroin scaffolds groups, more neurofilament positive nerve fiber ensheathed by myelin basic protein positive structure at the injury site were observed in the collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group (p<0.01, p<0.05). The results of Bielschowsky's silver staining indicated more nerve fibers was observed at the lesion site in the collagen/silk fibroin scaffolds + human umbilical cord-mesenchymal stem cells group compared with the spinal cord injury and collagen/silk fibroin scaffolds groups (p<0.01, p< 0.05). CONCLUSION: The results demonstrated that the transplantation of human umbilical cord-mesenchymal stem cells on a collagen/silk fibroin scaffolds could promote nerve regeneration, and recovery of neurological function after acute spinal cord injury.

Elastic modulus affects the growth and differentiation of neural stem cells.

It remains poorly understood if carrier hardness, elastic modulus, and contact area affect neural stem cell growth and differentiation. Tensile tests show that the elastic moduli of Tiansu and SMI silicone membranes are lower than that of an ordinary dish, while the elastic modulus of SMI silicone membrane is lower than that of Tiansu silicone membrane. Neural stem cells from the cerebral cortex of embryonic day 16 Sprague-Dawley rats were seeded onto ordinary dishes as well as Tiansu silicone membrane and SMI silicone membrane. Light microscopy showed that neural stem cells on all three carriers show improved adherence. After 7 days of differentiation, neuron specific enolase, glial fibrillary acidic protein, and myelin basic protein expression was detected by immunofluorescence. Moreover, flow cytometry revealed a higher rate of neural stem cell differentiation into astrocytes on Tiansu and SMI silicone membranes than on the ordinary dish, which was also higher on the SMI than the Tiansu silicone membrane. These findings confirm that all three cell carrier types have good biocompatibility, while SMI and Tiansu silicone membranes exhibit good mechanical homogenization. Thus, elastic modulus affects neural stem cell differentiation into various nerve cells. Within a certain range, a smaller elastic modulus results in a more obvious trend of cell differentiation into astrocytes.

Co-culture of oligodendrocytes and neurons can be used to assess drugs for axon regeneration in the central nervous system.

We present a novel in vitro model in which to investigate the efficacy of experimental drugs for the promotion of axon regeneration in the central nervous system. We co-cultured rat hippocampal neurons and cerebral cortical oligodendrocytes, and tested the co-culture system using a Nogo-66 receptor antagonist peptide (NEP1-40), which promotes axonal growth. Primary cultured oligodendrocytes suppressed axonal growth in the rat hippocampus, but NEP1-40 stimulated axonal growth in the co-culture system. Our results confirm the validity of the neuron-oligodendrocyte co-culture system as an assay for the evaluation of drugs for axon regeneration in the central nervous system.

TIPE2 Inhibits Lung Cancer Growth Attributing to Promotion of Apoptosis by Regulating Some Apoptotic Molecules Expression.

Recent studies found that TIPE2 was involved in cancer development. However, little is known about TIPE2 in lung cancer. Our study aims to clarify the role of TIPE2 in lung carcinogenesis. We examined the expression of TIPE2 in lung squamous cancer (LSC), small cell lung cancer and lung adenocarcinoma (AdC) tissues and found that TIPE2 expression was lost in small cell lung cancer, compared with adjacent non-tumor tissues. Overexpression of TIPE2 significantly inhibited the growth of lung cancer cell H446 in vitro and even suppressed tumor formation in vivo. Flow cytometry analysis found TIPE2 overexpression promoted apoptosis of H446. In TIPE2 over-expression cells, caspase-3, caspase-9, and Bax were significantly up-regulated while Bcl-2 was down-regulated. Moreover, coincident results were shown by immunohistochemistry in tumors from nude mice. TIPE2 inhibited the phosphorylation of Akt, while promoting the phosphorylation of P38, but had no effect on IκBα and ERK pathway. Taken together, TIPE2 promoted lung cancer cell apoptosis through affecting apoptosis-related molecules caspase-3, caspase-9, Bcl-2 and Bax, possibly via regulating P38 and Akt pathways, indicating that TIPE2 might be a novel marker for lung cancer diagnosis and therapy.

Quantitative proteomic analysis identifying three annexins as lymph node metastasis-related proteins in lung adenocarcinoma.

Lymph node status is a strong predictor of outcome for lung adenocarcinoma (AdC) patients. To explore novel potential protein markers for predicting lymph node metastasis of lung AdC, differential proteomic analysis on microdissected cancer cells from primary lung AdC and matched lymph node (LN) metastatic tissues by laser capture microdissection (LCM) was conducted using two-dimensional differential in-gel electrophoresis (2D-DIGE) coupled with mass spectrometry (MS). Annexins including annexin-1, annexin-2 and annexin-3 were identified and found to be overexpressed in matched LN metastatic tissues compared to primary lung AdC. Furthermore, differential expression levels of the three annexins were evaluated in paraffin-embedded 188 primary lung AdC tissues and 65 matched positive lymph node specimens using immunohistochemistry. High expression of annexin-1, annexin-2, and annexin-3 was all frequently observed in matched positive lymph node tissues compared to primary lung AdC. In primary lung AdC, expression levels of the three annexins in primary lymph node-positive AdC tissues were higher than primary lymph node-negative AdC tissues. Multivariate logistic regression analysis indicated annexin-1, annexin-2, and annexin-3 were all significant risk factors for lymph node metastasis. Furthermore, statistical analysis indicated that the concomitant expression of annexin-1/annexin-2, annexin-1/annexin-3, or annexin-2/annexin-3 and combined expression of all three markers had stronger correlation with lymph node metastasis. Our results suggest that annexin-1, annexin-2, and annexin-3 are identified as potential biomarkers associated with lymph node metastasis in lung AdC.

[Preparation and characterization of monoclonal antibody against HCCR protein].

AIM: Preparation of monoclonal antibody (mAb) to HCCR, which is a candidate biomarker for human hepatocellular carcinoma (HCC). METHODS: The recombinant protein HCCR-1(167-360); was expressed and was used as immunogen to immunize mouse for generation of mAb against HCCR. The protein Ep-HCCR, which displayed a epitope of HCCR, was also expressed and purified to use to detect serum antibody titer and to screen the positive clones of hybridmas. The properties of HCCR antibody were analyzed by ELISA, Western blot, immunofluorescence and immunohistochemistry. RESULTS: A hybridmas clone, which secreted anti-HCCR mAb, was obtained. The affinity constant (Kaff) of the mAb is 5.4×10(6); L/mol analyzed by ELISA; Western blot showed that the mAb could specifically recognize HCCR-1 and HCCR-2 expressed in HepG2 cells; The mAb was also used to detect the expression of HCCR proteins in hepatoma cells and HCC tissues. The results of immunofluorescence indicated that HCCR proteins mainly localized on the plasma membrane and cytoplasm of HepG2 cells. In addition, HCCR was found high-expressed in HCC tissues but not in normal liver tissue detected by Immunohistochemistry. CONCLUSION: A specific mAb against HCCR was successfully generated, which laid the foundation for establishing HCC detection method based on HCCR.

Identification of annexin A1 as a proinvasive and prognostic factor for lung adenocarcinoma.

Metastasis is the most common cause of death in lung cancer patients and is a major obstacle to the successful treatment. To discover novel metastasis-related proteins in lung adenorcinoma (AdC), quantitative proteomic analysis was performed between primary lung AdC tissues with (LNM AdC) and without lymph node metastasis (non-LNM AdC). In this study, annexin A1 was identified to be significantly up-regulated in LNM AdC compared with non-LNM AdC. Immunohistochemistry showed that annexin A1 over-expression was frequently observed in LNM AdCs and matched lymph node metastases compared with non-LNM AdCs. Annexin A1 over-expression was significantly associated with advanced clinical stage (P < 0.05) and lymph node metastasis (P < 0.05) and increased relapse rate (P < 0.05) and decreased overall survival (P < 0.05) in lung AdCs. Cox regression analysis indicated annexin A1 over-expression was an independent prognostic factor. Furthermore, suppression of annexin A1 expression by siRNA interference significantly inhibited the invasion ability of lung adenocarcinoma cell A549 in vitro. In conclusion, annexin A1 expression correlated with tumor stage, lymph node metastasis, relapse, and patient survival. Annexin A1 is proposed to function importantly in the progression of lung AdC.

[Generation of monoclonal antibody to GP73 based on antigen epitope].

AIM: Preparation of monoclonal antibody (mAb) against GP73 protein. METHODS: The N-terminal peptide (AAAERGAVELK) of GP73 protein was displayed on T7 phage, the recombinant phage was amplified and used as the immunogen to immunize mouse to produce antibody. The titer of the antiserum and the positive hybridoma clones which secreted the mAb against GP73 protein were detected by ELISA. The mAb specificity was assayed by ELISA and Western blot. RESULTS: The high specificity mAb against GP73 protein was selected from the mouse immunized with the recombinant T7 phages displaying the epitope of GP73 by cell fusion and screening. CONCLUSION: The appropriate protein epitope displayed on T7 phage could be used as alternative antigen to immunize animals to make specific antibody against the corresponding native protein.

[Production and identification of a monoclonal antibody against human HPPCn].

AIM: To make monoclonal antibody(mAb) against human HPPCn for the use in research on HPPCn's function and its relationship with liver diseases. METHODS: The female BALB/c mice were immunized with the recombinant HPPCn proteins. Splenocytes and Sp2/0 cells were fused with PEG-1500. The positive clone was identified through indirect ELISA and then subcloned by limited dilution. Indirect ELISA, Western blot and Ig sub-class identification kit were used to identify the mAb's properties. By immunofluorescence experiments, we studied the cellular localization of HPPCn. The mAb epitope was also analyzed using peptide phage display technology. RESULTS: An anti-HPPCn mAb, named W2-D5, was obtained. It belongs to IgG1 subclass. It could specially bind to human HPPCn. Furthermore, by immunofluorescence results, wo confirmed HPPCn located in the nucleus and our mAb could combined with the natural protein. With the mAb, the minimal detectable concentration was 0.1 µg/L for HPPCn; The peptide sequence of HPPCn7₋13;(IHLELRN)was identified as the epitope of the mAb. CONCLUSION: An anti-HPPCn mAb with high specificity and high affinity was successfully obtained.