Postoperative prognostic model for patients with clear cell renal cell carcinoma in a Chinese population.

OBJECTIVES: To develop a predictive model for the oncological outcomes of clear cell renal cell carcinoma in a Chinese population. METHODS: A retrospective study of 1108 patients with clear cell renal cell carcinoma who underwent nephrectomy or partial nephrectomy between January 2006 and December 2013 was carried out. Recurrence-free survival was calculated using Kaplan-Meier analysis. Differences between the groups were compared using the log-rank test. Cox proportional hazard regression was used to test associations between features and outcomes. The discriminative ability of the models was validated using Harrell's concordance index and bootstrapping. RESULTS: Overall, 942 patients who met the inclusion criteria had been followed. The median follow-up period was 72 months (range 1-143 months). Multivariate analysis showed that age, Eastern Cooperative Oncology Group performance status, preoperative platelet count, neutrophil-to-lymphocyte ratio, tumor size, 2010 tumor stage (pT3 and pT4) and Fuhrman nuclear grade were independent risk factors affecting recurrence-free survival in clear cell renal cell carcinoma patients (P < 0.05). These factors were assigned to develop a new model. The patients were divided into three groups based on the risk of recurrence. The difference among the prognoses of patients in the three groups was statistically significant (P < 0.05). The concordance index for our new model and that for Leibovich's 2018 model were 0.791 and 0.750, respectively. CONCLUSIONS: In the present study, the new model has a higher concordance index than does Leibovich's 2018 model of clear cell renal cell carcinoma in the Asian population, with no added pain for patients. This new model might be an appropriate risk stratification tool for clinical work.

[Clinicopathological features of primary seminal vesicle adenocarcinoma: A report of 4 cases and review of the literature].

OBJECTIVE: To investigate the clinicopathological characteristics, diagnosis, and treatment of primary seminal vesicle adenocarcinoma (SVAC). METHODS: We analyzed the clinical data and clinicopathological characteristics of 4 cases of primary SVAC treated in the Department of Urology of the Second Hospital of Tianjin Medical University and reviewed relevant literature. RESULTS: All the 4 patients were treated by open radical resection of the seminal vesicle and prostate and pathologically diagnosed with SVAC. Preoperative prostatic biopsy had shown 1 of the cases to be negative, while preoperative CT and transrectal ultrasound had revealed a huge pelvic cystic neoplasm in another patient. Immunohistochemistry manifested that the 4 cases were all negative for prostate-specific antigen (PSA), prostatic acid phosphatase (PAP), and cytokeratin 20 (CK20), but positive for cancer antigen 125 (CA125) and CK7. All the patients recovered smoothly after surgery and experienced no recurrence or metastasis during 154, 41, 20, and 12 months of follow-up. CONCLUSIONS: Primary seminal vesicle carcinoma is extremely rare and presents in an advanced stage. Immunohistochemistry plays a valuable role in its differential diagnosis. Various combinations of radical surgery, radiotherapy, androgen-deprivation therapy, and chemotherapy are recommended for the treatment of the disease.

Leiomyomas of the bilateral tunica albuginea of testes: a case report.

Leiomyoma of the bilateral testicular tunica albuginea is extremely rare. To our knowledge, there are only 3 definitely reported cases. This is the first report of bilateral testicular tunica albuginea leiomyomas as a potential cause of male infertility. Herein, we report a case of a 47-year-old man who presented with painless bilateral testicular masses for more than 30 years, besides he also suffered from unexplained infertility. The complete resection of the tumors was performed. The final pathological diagnosis was leiomyomas of the bilateral tunica albuginea. Postoperatively, the patient underwent testicular biopsy. Histopathology confirmed moderate atrophy of bilateral testes, and the number of spermatogenic cells in the seminiferous tubules were significantly decreased. In this case, bilateral testicular dysplasia is the root reason for the patient's infertility. Thus, despite the benign nature of bilateral testicular tunica albuginea leiomyomas, they may cause bilateral testicular hypoplasia and infertility in men. In the case of men with fertility requirements, early local mass excision is often necessary.

Neuroendocrine Prostate Cancer (NEPC) progressing from conventional prostatic adenocarcinoma: factors associated with time to development of NEPC and survival from NEPC diagnosis-a systematic review and pooled analysis.

PURPOSE: An often under-recognized late manifestation of prostate adenocarcinoma (PCa) is the development of treatment-related neuroendocrine prostate cancer (NEPC). The aim of this study is to identify the risk factors related to survival after NEPC diagnosis (NEPCS) and time from initial diagnosis of PCa to development of NEPC (TTNEPC). PATIENTS AND METHODS: A literature search on NEPC was performed using databases such as MEDLINE and EMBASE. Studies were eligible if outcomes data (NEPCS and/or TTNEPC) were reported in patients with a prior history of PCa and histopathologically confirmed NEPC. NEPCS and TTNEPC were evaluated using the Cox regression model with the robust sandwich estimates of the covariance matrix. RESULTS: There were 54 eligible publications, contributing 123 patients. The median TTNEPC was 20 months. In multivariable analyses, the Gleason score was significantly associated with shorter TTNEPC (hazard ratio [HR], 1.66; P = .032). The median NEPCS was 7 months. In multivariable analyses, the number of organs with metastatic disease at NEPC was significantly associated with shorter NEPCS (HR, 3.31; P = .001). Type of treatment after NEPC was significantly associated with longer NEPCS, with HRs of 0.66 (radiotherapy v palliative therapy; P = .034), 0.38 (chemotherapy v palliative therapy; P = .018), and 0.29 (chemoradiotherapy v palliative therapy; P = .012), respectively. CONCLUSION: Treatment-related NEPC is an often under-recognized late manifestation of PCa with poor prognosis. Our study found that Gleason score was the only independent factor contributing to TTNEPC. Once NEPC is diagnosed, type of treatment and the number of organs with metastatic disease were the most important factors related to survival.

[Application of urinary proteomics in early diagnosis of bladder urothelial carcinoma].

OBJECTIVE: To investigate the difference in urinary proteome between patients with bladder urothelial carcinoma (BUC) and healthy volunteers and to provide a basis for the early diagnosis of BUC. METHODS: The urine samples from BUC patients and healthy volunteers (controls) were treated by 25% ethanol precipitation and two-dimensional gel electrophoresis (2-DE), and the obtained urinary proteins were subjected to Coomassie brilliant blue staining and analysis by PDQuest 8.0 (2-DE image analysis software); the differentially expressed proteins were sequenced by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry and identified using the Swiss-Prot database; the differential expression of these proteins was verified by western blot. RESULTS: High-resolution and high-reproducibility 2-DE images were obtained from the urine samples of BUC patients and controls, with 789 ± 18 and 762 ± 14 protein spots, respectively. Compared with the control group, the BUC grouP had significantly decreased expression of 6 protein spots and significantly increased expression of 11 protein spots. The mass spectrometry revealed five proteins with increased expression in the BUC group, including fibrinogen, lactate dehydrogenase B, apolipoprotein A1, clusterin, and haptoglobin, and the results were confirmed by western blot. CONCLUSION: There is significant difference in urinary proteome between BUC patients and healthy volunteers; the identification of differentially expressed proteins in urine lays the foundation for identifying potential molecular markers in early diagnosis of BUC.

[Significance of apolipoprotein A1 as biomarker for early diagnosis and classification of bladder urothelial carcinoma].

OBJECTIVE: To investigate the significance of apolipoprotein (Apo)-A1 in urine as a biomarker for early diagnosis and classification of bladder urothelial carcinoma (BUC). METHODS: Urine samples were divided into four groups: normal control group, benign bladder disease group, low-grade malignant BUC group, and high-grade malignant BUC group. Apo-A1, which showed significantly different expression among the four groups, was selected according to the two-dimensional electrophoresis (2-DE) images of the four groups, and enzyme-linked immunosorbent assay (ELISA) was used to quantify Apo-A1 in the four groups. A receiver operating characteristic (ROC) curve was generated, and the optimal operating points on the ROC curve were found to determine the critical concentrations of Apo-A1 for early diagnosis of BUC and differentiation of low-grade and high-grade malignant BUC. The results were verified clinically, and the specificity and sensitivity were calculated. RESULTS: The 2-DE images showed that that the level of Apo-A1 increased from the normal control grouP to high-grade malignant BUC group. The ELISA showed that there was no significant difference in Apo-A1 level between the normal control grouP and benign bladder disease group, but the Apo-A1 level was significantly higher in the BUC groups than in the normal control grouP and benign bladder disease grouP (P < 0.01); the high-grade BUC grouP had a significantly higher Apo-A1 level than the low-grade BUC grouP (P < 0.01). The BUC patients and those without BUC could be differentiated with an Apo-A1 concentration of 18.22 ng/ml, while the low-grade and high-grade malignant BUC could be differentiated with an Apo-A1 concentration of 29.86 ng/ml. When used as a biomarker, Apo-A1 had a sensitivity of 91.6% (98/107) and a specificity of 85.7% (42/49) for diagnosis of BUC and had a sensitivity of 83.7% (41/49) and a specificity of 89.7% (52/58) for BUC classification. CONCLUSION: Apo-A1 may be a biomarker for early diagnosis and classification of BUC and shows promise for clinical application.

[Construction of human phage antibody library and screening for human monoclonal antibodies of amylin].

AIM: To screen monoclonal antibodies to amylin from a constructed human phage antibody library and identify their antigenic specificity and combining activities. METHODS: The heavy chain Fd fragment and light chain of human immunoglobulin genes were amplified from peripheral blood lymphocytes of healthy donors using RT-PCR, and then inserted into phagemid pComb3XSS to generate a human phage antibody library. The insertion of light chain or heavy chain Fd genes were identified by PCR after the digestion of Sac I, Xba I, Xho Iand Spe I. One of positive clones was analyzed by DNA sequencing. The specific anti-amylin clones were screened from antibody library against human amylin antigens and then the positive clones were determined by Phage-ELISA analysis. RESULTS: A Fab phage antibody library with 0.8×10(8); members was constructed with the efficacy of about 70%. DNA sequence analysis indicated V(H); gene belonged to V(H);3 gene family and V(λ); gene belonged to the V(λ); gene family. Using human amylin as panning antigen, specific anti-amylin Fab antibodies were enriched by screening the library for three times. Phage-ELISA assay showed the positive clones had very good specificity to amylin antigen. CONCLUSION: The successful construction of a phage antibody library and the identification of anti-amylin Fab antibodies provide a basis for further study and preparation of human anti-amylin antibodies.

[Correlation of histological prostatitis with PSA, prostate volume, PSAD, IPSS, Qmax and PVR in BPH patients].

OBJECTIVE: To explore the correlation of histologically proven prostatitis with the level of prostate specific antigen (PSA), prostate volume, PSA density (PSAD), international prostate symptom score (IPSS), maximum flow rate (Qmax) and post-void residual volume (PVR) in men with symptoms of benign prostate hyperplasia (BPH). METHODS: Totally 673 patients surgically treated for BPH were divided into Groups A and B in accordance with histological findings, the former including those with histological prostatitis, and the latter without it. Comparisons were made between the two groups in the PSA level, prostate volume, PSAD, IPSS, Qmax and PVR. RESULTS: The PSA level, prostate volume, IPSS and PVR were significantly higher in Group A ([5.64 +/- 2.48] microg/L, [43.66 +/- 13.11] ml, 24.72 +/- 5.39 and [124.90 +/- 49.80] ml) than in B ([4.97 +/- 1.99] microg/L, [40.41 +/- 11.44] ml, 23.40 +/- 6.21 and [112.73 +/- 50.03] ml) (P<0.05), while Qmax markedly lower in the former ([6.94 +/- 3.23] ml/s) than in the latter ([7.75 +/- 3.52] ml/s) (P<0.05), but PSAD showed no statistically significant difference between the two groups (0.129 +/- 0.048 vs 0.123 +/- 0.034, P>0.05). CONCLUSION: Histological prostatitis can significantly increase the PSA level, prostate volume, IPSS and PVR, and reduce the Qmax of the patient, but is not correlated with PSAD. It is an important factor influencing the clinical progression of BPH.

H-ras mutation detection in bladder cancer by COLD-PCR analysis and direct sequencing.

OBJECTIVE: A sensitive mutation detection method called co-amplification at lower denaturation temperature-polymerase chain reaction (COLD-PCR) was applied to improve the detection frequencies of expressive mutations in the H-ras gene, including exons 1 and 2, in a group of Chinese patients diagnosed with bladder cancer. MATERIALS AND METHODS: The expressive mutations in the H-ras gene in 86 fresh tissues of human bladder cancer were identified by COLD-PCR or conventional PCR, followed by direct sequencing. RESULTS: A high frequency of silent mutations of 29.1% (25 of 86) in exon 1 (c.81T>C, H27H) and activating mutations of 8.1% (7 of 86) were detected by COLD-PCR, yielding a 36% improvement in mutation detection compared with conventional PCR. No significant association was shown between activating mutations and clinicopathologic parameters, but the frequencies of silent mutations in recurrent tumors were higher than those in primary tumors (p = 0.034). CONCLUSIONS: COLD-PCR is a highly sensitive, reliable, and convenient clinical assay for mutation detection. The adoption of the method is straightforward and requires no additional reagents or instruments. Silent mutations might be important genomic alterations in bladder cancer, and play a role in bladder cancer recurrence.

[Expressions of integrinalpha2beta1 and CD133 in benign prostatic hyperplasia complicated by prostatitis and their significance].

OBJECTIVE: To study the expressions of Integrinalpha2beta1 and CD133 in benign prostatic hyperplasia (BPH) complicated by prostatitis and their significance. METHODS: Specimens were obtained from 56 BPH patients undergoing transvesical prostatectomy. Paraffin sections of the specimens were subjected to HE staining for pathological examination of inflammatory changes under the light microscope. Twenty-four patients with simple BPH were included in Group A, and the other 32 with BPH complicated with prostatitis in Group B. The expressions of Integrinalpha2beta1 and CD133 in the prostatic tissues of the two groups were determined by immunohistochemistry, Western blotting and IPP6.0 image analysis software. RESULTS: The expressions of Integrinalpha2beta1 and CD133 were significantly higher in Group B than in A (P < 0.05), and so were the mean relative value of the optical density of Integrinalpha2beta1 (0.29 +/- 0.18 vs 0.04 +/- 0.03) and that of CD133 (0.08 +/- 0.07 vs 0.0020 +/- 0.0018) (P < 0.05). CONCLUSION: Inflammation can up-regulate the expressions of Integrinalpha2beta1 and CD133 in BPH tissue.

[Undifferentiated prostate sarcoma with cartilage metaplasia: a case report and review of the literature].

OBJECTIVE: To investigate the clinical presentations and pathologic features of undifferentiated sarcoma of the prostate with cartilage metaplasia, and to clarify its category. METHODS: We analyzed the clinical data of a case of undifferentiated sarcoma of the prostate with cartilage metaplasia treated by surgical resection. The tumor tissue was subjected to routine HE and immunohistochemical staining, its histological structure and immunohistochemical expression were observed under the light microscope, and relevant literature on its manifestations was reviewed. RESULTS: The case was pathologically diagnosed as gray prostate tumor, with chondrosarcomatous and undifferentiated malignant mesenchymal components under the light microscope. Immunohistochemical staining revealed vimentin (+), local CD117 (+/-), SMA (-), Des (-), myoglobin (-), CD34 (-), CK7 (-), and CK8 (-). Tumor metastasis was found 2 months after the operation, and the patient died 4 months later. CONCLUSION: Undifferentiated sarcoma of the prostate with cartilage metaplasia is a very rare and highly malignant aggressive tumor, which can be diagnosed by biopsy and immunohistochemistry.

[Prostate cancer with five different histological features: a case report and review of the literature].

OBJECTIVE: To study the clinical manifestations, pathological characteristics and treatment methods of prostate cancer with five different histological features. METHODS: We reported 1 case of prostate cancer with five different histological features and further analyzed the diagnosis, pathology and treatment of the disease by reviewing the relevant literature. RESULTS: The patient was an 84-year-old male, admitted due to difficult urination and dribbling urine for 1 year, hematuria for 8 months and deterioration for 2 weeks. Prostate cancer was indicated by rectal examination, ultrasonography, CT, MRI and PSA, and confirmed by biopsy. Considering the general condition of the patient, we performed electrotransurethral resection under epidural anesthesia to alleviate his urinary symptoms and remove suspected tumor tissues. Postoperative pathology showed the case to be prostate adenocarcinoma, histologically characterized by cribriform carcinoma, acinar carcinoma, diffuse invasive carcinoma, ductal carcinoma, and mucinous adenocarcinoma, with a Gleason score of 9. Bicalutamide and goserelin were administered postoperatively. Systemic metastasis occurred 10 months later, and the patient died 1 year after the operation. CONCLUSION: Prostate cancer with five different histological features is extremely rare. Its early diagnosis is difficult and mainly depends on pathological and immunohistochemical examinations, and radical prostatectomy can be considered for its treatment.

Differences in shotgun protein expression profile between superficial bladder transitional cell carcinoma and normal urothelium.

This study was undertaken to identify differences in protein expression profiles between superficial bladder transitional cell carcinoma (BTCC) and normal urothelial cells. We used laser capture microdissection (LCM) to harvest purified cells, and used two-dimensional liquid chromatography (2D-LC) followed by electrospray ionization-tandem mass spectrometry (ESI-MS/MS) to separate and identify the peptide mixture. A total of 440/438 proteins commonly appeared in 4 paired specimens. Multi-step bioinformatic procedures were used for the analysis of identified proteins; 175/179 of the 293/287 proteins that were specific expressed in tumor/normal cells own gene ontology (GO) biological process annotation. Compared with the entire list of the international protein index (IPI), there are 52/46 GO terms exhibited as enriched and 6/10 exhibited as depleted, respectively. Significantly altered pathways between tumor and normal cells mainly include oxidative phosphorylation, focal adhesion, etc. Finally, descriptive statistics show that the shotgun proteomics strategy has practice directive significance for biomarker discovery by two-dimensional electrophoresis (2-DE) technology.

Quantitative risk stratification and individual comprehensive therapy for invasive bladder cancers in China.

BACKGROUND: To evaluate the risk factors for invasive bladder cancer and to develop a predictive model for the improvement of individual comprehensive therapy for invasive bladder cancers. MATERIALS AND METHODS: The records of 356 patients with invasive bladder cancer, operated on at three Chinese medical institutes, were reviewed. The Cox proportional hazards regression model was used to assess the clinical and pathological variables affecting disease-free survival (DFS). The regression coefficients determined by Cox regression analysis were used to construct a predictive index (PI). PI was used to categorize the patients into different risk groups. Kaplan-Meier survival curves followed with log-rank test were plotted to compare the difference. RESULTS: Tumor configuration (RR = 1.60, P = 0.01), multiplicity (RR = 1.41, P = 0.04), histological subtype (RR = 2.13, P < 0.01), tumor stage (RR = 2.50, P < 0.01), tumor grade (RR = 2.35, P < 0.01), node status (RR = 2.48, P < 0.01), and neoadjuvant chemotherapy (RR = 0.46, P = 0.02), had independent prognostic significance for DFS. PI = 0.47 x (configuration) + 0.34 x (multiplicity) + 0.76 x (tumor histological subtype) + 0.92 x (stage) + 0.86 x (grade) + 0.91 x (node status) - 0.79 x (neoadjuvant chemotherapy). The range of PI was -0.32 to 6.52, which was equally divided into three risk groups with significant differences on Kaplan-Meier curves and a log-rank test (P < 0.01). Meanwhile, the patient's probability of survival could be calculated by PI. CONCLUSIONS: Seven factors (tumor configuration, multiplicity, histological subtype, tumor stage, tumor grade, node status, neoadjuvant chemotherapy) affect the prognosis after radical cystectomy (RC) for invasive bladder cancer. PI can be used to optimize the individual comprehensive therapy. Given fewer perioperative complications, fast recovery from surgery and relatively satisfactory quality of life, ureterocutaneostomy, and ileal conduit are suitable for the patients with short expected life spans.

Shotgun proteome expression profile of microdissected superficial transitional cell carcinoma and biomarker discovery from urine.

The aim of this study was to globally characterize the expression profile of superficial transitional cell carcinoma using shotgun proteome strategy and to discuss the biomarker panel identified from urine. We identified 440 commonly expressed proteins from four samples of superficial transitional cell carcinoma using laser capture microdissection coupled with two-dimensional liquid chromatography tandem mass spectrometry. The identified proteins were further analyzed using bioinformatics tools and compared with the published literature. Compared with the entire list of the International Protein Index, there were 41/22 Gene ontology (GO) terms found to be enriched/depleted within the biological process annotation. GO biological process enrichment/depletion analysis was consistent with the results of urine proteome analysis. Proteins classified under the terms cell adhesion, cell proliferation and cell differentiation are good candidate biomarkers for cancer detection from urine. In conclusion, the present study identified an extensive expression profile in superficial transitional cell carcinoma of the bladder, providing information for the understanding of cancer cell biology and the discovery of a biomarker panel from urine.

[Expression and gene mutation of cluster of differentiation 9 in lung cancer cells induced by mineral powder in Gejiu].

OBJECTIVE: To investigate the expression and gene mutation of cluster of differentiation 9 (CD9) in the pathway of the mineral powder induced malignant transformation in immortalized human bronchial epithelial cells (BEAS-2B) in Gejiu. METHODS: BEAS-2B cells served as the control group and its malignant transformation cells induced by mineral powder in Gejiu were considered as experiment group. The expression of CD9 protein in 20 bottles of BEAS-2B cells and 20 bottles of malignant transformation cells was evaluated by immunocytochemistry. The mRNA expression of CD9 in 10 bottles of BEAS-2B cells and 10 bottles of malignant transformation cells was examined by reverse transcriptase polymerase chain reaction (RT-PCR). Gene mutation was detected in the products of RT-PCR by DNA sequencing. RESULTS: There was significant difference between the expression of CD9 protein in BEAS-2B cells (100%, 20/20) and that in its malignant transformation cells (35%, 7/20 P < 0.01). The expression of CD9 mRNA in BEAS-2B cells 0.91 +/- 0.09 was significantly higher than that in its malignant transformation cells (0.34 +/- 0.14) (P < 0.01). Two point mutation of CD9 gene was detected in the malignant transformation cells of BEAS-2B by DNA sequencing. The change of G-->T in the base of 231 led to the change of Gln-->His in the amino acids of 40. The change of T-->A in the base of 119 led to the change of Val-->Asp in the amino acids of 3. CONCLUSION: The absence or down-regulation of CD9 expression and point mutation in the malignant transformation cells of BEAS-2B may play a considerable role in the pathway of the malignant transformation in the BEAS-2B cells induced by mineral powder in Gejiu.

[Overexpression of PTEN gene inhibits proliferation of bladder transitional carcinoma cell line EJ].

OBJECTIVE: To evaluate the anticancer effects of exogenous human WT-PTEN overexpression on bladder transitional carcinoma cell line EJ. METHODS: The plasmid containing WT-PTEN or mutant PTEN was separately transfected into bladder transitional carcinoma cell line EJ, and the protein expression of PTEN in the EJ cells was detected by Western blot. Cell morphological changes were observed under the inverted microscope and transmission electron microscope. MTT test was used to assess the effect of PTEN on proliferation and anticancer effects for mitomycin and theraubicin. The change of bcl-2 expression in the cells was measured by Western blot. The empty plasmid was used as control. RESULTS: Western blot analysis showed that EJ cells expressed high level of PTEN protein after transfection with WT-PTEN or mutant PTEN plasmid. Abnormal morphological changes of the cells were observed in WT-PTEN transfected groups. The growth of EJ cells treated with WT-PTEN was significantly inhibited by 40.1% and anticancer effects were enhanced by mitomycin and theraubicin, but the cells transfected with mutant PTEN plasmid did not show such similar biological behavior. CONCLUSION: WT-PTEN gene transfection can suppress the in vitro growth and induce apoptosis of bladder transitional carcinoma cell line EJ cells. Mutant PTEN does not show similar biological behavior. Overexpression of WT-PTEN inhibits cancer cell proliferation by down-regulating bcl-2 expression in the cells.

In silico-initiated cloning and molecular characterization of cortexin 3, a novel human gene specifically expressed in the kidney and brain, and well conserved in vertebrates.

We report on the in silico-initiated cloning and molecular characterization of CTXN3 (cortexin 3), a new human gene that was specifically expressed in the kidney and brain due to tissue-specific alternative exon 1 usage, on chromosome 5q23.2 using digital gene expression displayer (DGED) and a novel in silico cloning approach based on both expressed sequence tags (ESTs) and genomic sequence. The gene CTXN3 included 3 exons and spanned an approximate 9.6-kb region of human chromosome 5q23. Two alternative transcript variants (GenBank accession nos. AB219764 and AB219832) were 1660 and 1458 bp long, respectively, encoding for an 81-amino acid protein with a predicted molecular weight of 8933.4 Da. The predicted human CTXN3 protein had 43% identity with function-unknown protein cortexin, which showed brain-specific expression. Further analysis of the encoded protein using PSORT II, TMpred, and PSIPRED programs demonstrated a putative single membrane-spanning domain in the middle of the CTXN3 amino acid sequence, indicating that it might be an integral membrane protein which may mediate extracellular or intracellular signaling of the kidney or brain. Analysis of the predicted CTXN3 orthologs from different species showed that these proteins are highly conserved in vertebrates. In conclusion, a combination of bioinformatics and molecular approaches is useful in the identification of genes expressed in specific tissues. Selective expression of CTXN3 in the kidney and brain, the amino acid identity to cortexin, and its high conservation among different species indicate that CTXN3 may be involved in a process specifically restricted to kidney and brain tissue function.

[Construction and primary identification of a naive Fab fragment phage library].

OBJECTIVE: To construct a naive human Fab fragment phage display library, provide a platform for human antibody preparation and a new therapy for the malignant tumors. METHODS: Peripheral blood lymphocytes were isolated from 200 ml blood, which was obtained from a healthy blood donor. The heavy chain Fd fragments and light chain cDNA synthesized from the total RNA of lymphocytes were amplified by PCR and the amplification products were ligated into the phagemid vector pComb3, then the ligated sample was transformed into competent E. coli XL1-Blue. The transformed cells were infected with VCSM13 helper phage to yield recombinant phage antibody of Fabs. The phagemids abstracted from amplified E. coli were cut with endonucleases such as Sac I, Xba I, Spe I and Xho I and amplified by PCR to monitor the insertion of the light chain or heavy chain Fd genes. Human albumin and interleukin-2 were utilized as antigens to conduct respectively three rounds of panning to the original Fab antibody library. RESULTS: By combination of light chain and heavy chain genes, an antibody library containing 1.2 x 10(6) clones was obtained, and both the cutting of enzymes and PCR showed that there were the light chain or heavy chain Fd genes of the phagemids. After the original antibody library having been panned respectively by two kinds of antigen proteins, it gained enrichment in different degree. CONCLUSION: Utilizing the technology of phage surface display, special antibody can be gained from the human naive Fab phage display library, which can be used as a new therapy for tumors.