[Epidemiological characteristics and serum antibody detection of a COVID-19 aggregated outbreak in vaccinated population]

An epidemiological investigation was conducted on a cluster epidemic of COVID-19 in the vaccinated population in Beijing in 2022, and serum samples were collected from 21 infected cases and 61 close contacts (including 20 cases with positive nucleic acid in the isolation observation period). The results of antibody detection showed that the IgM antibody of two infected persons was positive, and the IgG antibody positive rates of patients who were converted, not converted to positive and infected persons were 36.84% (7/19), 63.41% (26/41) and 71.43% (15/21), respectively. About 98.78% of patients had been vaccinated with the SARS-CoV-2 inactivated vaccine. The positive rate of IgG antibody in patients immunized with three doses of vaccine was 86.00% (43/50), which was higher than that in patients with one or two doses [16.12% (5/31)]. The antibody level of M (Q₁, Q₃) in patients immunized with three doses was 4.255 (2.303, 7.0375), which was higher than that in patients with one or two doses [0.500 (0.500, 0.500)] (all P values<0.001). The antibody level of patients who were vaccinated less than three months [7.335 (1.909, 7.858)] was higher than that of patients vaccinated more than three months after the last vaccination [2.125 (0.500, 4.418)] (P=0.007). The positive rate and level of IgG antibody in patients who were converted to positive after three doses were 77.78% (7/9) and 4.207 (2.216, 7.099), respectively, which were higher than those in patients who were converted after one or two doses [0 and 0.500 (0.500, 0.500)] (all P values<0.05).

[Establishment and validation of prognostic risk score model for esophageal squamous cell carcinoma based on immune related genes]

Objective: To find the biomarkers that accurately predict the survival of patients with esophageal squamous cell carcinoma (ESCC). Methods: The immune related genes that were significantly related to the overall survival (OS) of patients with ESCC were screened from The Cancer Genome Atlas (TCGA) database to construct a prognostic risk score model. The prognoses of the high-risk and low-risk groups were compared by Kaplan-Meier method. The accuracy of the model was evaluated by the receiver operating characteristic (ROC) curve. Tumor tissue samples of 83 patients with pathological diagnosis of ESCC were collected from Anyang Cancer Hospital for external verification. Cox regression analysis was used to comprehensively evaluate the effects of prognostic risk score and various clinical characteristics on OS of patients with ESCC. Results: Seven immune-related genes that were significantly related to survival prognosis were selected from the TCGA database and included in the prognostic risk score model, which were S100A12, SLC40A1, FABP9, TNFSF10, IGHA2, IL1F10, and STC2. The 1- and 2-year survival rates of the low-risk group (40 cases) were 94.3% and 82.5%, respectively, while those of the high-risk group (40 cases) were 75.9% and 32.9%, respectively.The prognosis of the high-risk group was worse than that of the low-risk group (P<0.001). The 83 external validation samples obtained consistent results by using the prognostic risk score model. The prognostic risk score was positively correlated with the content of CD4(+) T lymphocytes in ESCC (r(s)=0.259, P=0.020), but not correlated with the content of B lymphocytes, CD8(+) T lymphocytes, neutrophils, macrophages or dendritic cells (P>0.05). Conclusions: S100A12, SLC40A1, FABP9, TNFSF10, IGHA2, IL1F10, and STC2 were risk genes significantly associated with OS of patients with ESCC. The prognostic risk score was an independent prognostic factor for the OS of patients with ESCC, and it was correlated with the content of CD4(+) T lymphocytes in ESCC tissue.

CircRNA_100782 promotes roliferation and metastasis of gastric cancer by downregulating tumor suppressor gene Rb by adsorbing miR-574-3p in a sponge form

OBJECTIVE

The aim of this study is to investigate the expression levels of circRNA_100782 in gastric cancer tissues, and its function of regulating tumor suppressor gene Rb by absorbing miR-574-3p in a sponge form.

PATIENTS AND METHODS

qRT-PCR was performed to detect the expressions of circRNA_100782 at different stages during gastric cancer tissues. CCK-8 assay was performed to evaluate the osteoclast proliferation and differentiation. The correlation between miR-574-3p and circRNA_100782 was detected by statistical analysis. Bioinformatics and Luciferase assay were performed to explore the interaction and binding site of circRNA_100782 and miR-574-3p. The mice Rb 3'-UTR were cloned into the Luciferase reporter vector and miR-574-3p binding mutants were constructed to validate the inhibited regulation of miR-574-3p to the expression of Rb.

RESULTS

In the current study, compared with adjacent non-cancerous normal tissues, the expressions of circRNA_100782 and Rb were both downregulated in human gastric cancer cells. Through qRT-PCR and CCK-8 assay, we found that the expression of circRNA_100782 is related to the proliferation of gastric cancer cells. Besides, we also found that circRNA_100782 regulated the migration ability of gastric cancer cells through transwell assay. The bioinformatics prediction and luciferase assay demonstrated that circRNA_100782 can serve as a molecular sponge to further regulate the expression of Rb by sponging with miR-574-3p; moreover, circRNA_100782 can serve as a ceRNA for miR-574-3p to further regulate the expression of Rb.

CONCLUSIONS

In this research, we discovered that circRNA_100782 was downregulated in gastric cancer cells and is associated with cell proliferation and invasion by inhibiting tumor suppressor gene Rb by interacting with miR-574-3p.

C/EBPβ promotes the viability of human bladder cancer cell by contributing to the transcription of bladder cancer specific lncRNA UCA1

Urothelial Carcinoma Antigen 1 (UCA1) is a cell and tissue specific long non-coding RNA (lncRNA) associated with the tumorigenesis and invasion of bladder cancer. However, the mechanism driving the over-transcription of UCA1 in bladder cancer cells remains unclear. It has been reported that C/EBPβ has a significant role of regulation in tumorigenesis. Here we report that the expression of UCA1 was dramatically inhibited in 5637 cells with C/EBPβ down-regulation. Additionally, the function tests indicated that C/EBPβ could promote 5637 cells growth and colony formation by inducing the expression level of UCA1. These data suggest that C/EBPβ was involved in transcriptional regulation of UCA1 and contributed substantially to its high expression and proliferation promoting in bladder cancer cells.

[Resistance mechanism of programmed death-1 antibody]

Accompanied with more elaborate and deeper exploration, immunotherapy has been considered one of the most important therapeutic manners for tumor treatment besides conventional operative, chemotherapeutic, radiotherapeutic and targeted-therapeutic strategies. The application of programmed death-1 (PD-1) antibody has provided a new therapeutic option for patients and becomes a research focus of immunotherapy field. PD-1 antibody has been permitted to apply to the treatment of different types of cancers such as melanoma. PD-1 has been demonstrated to be highly effective, including the steady tumor growth control, even complete remission acquired. Although the PD-1 antibody displays great therapeutic effectiveness and application prospects, an increasingly number of drug resistant phenomena have also occurred. Little has been known about the mechanisms of PD-1 antibody resistance by now. However, exploring this mechanism, innovating new treatment mode of drug combination, avoiding the occurrence of drug resistance and decreasing the adverse influence of drug resistance, even reversing it, will be useful to guide the adjustment of treatment strategies, continuously improve the effects of immunotherapy, and give patients long-term survival benefit.

Downregulation of miR-193a-3p inhibits cell growth and migration in renal cell carcinoma by targeting PTEN

Although miR-193a-3p has been found to be dysregulated in variety of human tumors, little is known about its role in renal cell carcinoma. This study was designed to investigate the function and underlying mechanism of miR-193a-3p in human renal cell carcinoma tissues and cell lines. Here, we demonstrated that the expression of miR-193-3p was increased in renal cell carcinoma tissues and cell lines. In addition, knockdown of miR-193a-3p significantly inhibited cell proliferation and colony formation and induced cells into G1 phase arrest. Meanwhile, the migration potential of 786-O cells was also decreased compared to control group. Furthermore, we identified PTEN as a direct and functional target of miR-193a-3p, at least partly responsible for promoting tumor effect of miR-193a-3p in renal cell carcinoma. Taken together, the findings indicated for the first time that miR-193a-3p functions as a tumor-promoting microRNA by directly targeting PTEN in renal cell carcinoma.

MicroRNA-142-5p promotes cell growth and migration in renal cell carcinoma by targeting BTG3

PURPOSE

Some microRNA (miRNA) levels have been found to be dysregulated in cancer patients, suggesting the potential usefulness of miRNAs in cancer therapies. The purpose of this study was to investigate the expression of miR-142-5p in human renal cell carcinoma (RCC) and its potential role in tumor growth and metastasis.

METHODS

The expression level of miR-142-5p in human RCC tissue and cell lines was determined by quantitative reverse transcription polymerase chain reaction analysis. MTT, colony formation, Transwell, and cell cycle assays were performed to explore the potential functions of miR-142-5p in human RCC cells. The potential target gene of miR-142-5p was identified and confirmed via luciferase reporter assays.

RESULTS

miR-142-5p expression was elevated in RCC tissues and cell lines. Overexpression of miR-142-5p significantly promoted cell proliferation and colony formation and could prevent G1 phase arrest among RCC 786-O cells. Meanwhile, the migration potential of 786-O cells was greater than that of control cells. BTG3 was identified as a direct target of miR-142-5p, and re-expression of BTG3 reversed the miR-142-5p-induced cell proliferation.

CONCLUSION

miR-142-5p promoted the proliferation and migration of RCC cells by targeting BTG3. With this potential onco-miRNA role in the progression of RCC, miR-142-5p may be a therapeutic target for the treatment of RCC.

PTTG1, A novel androgen responsive gene is required for androgen-induced prostate cancer cell growth and invasion

Androgens (AR) play an important role in initiation and progression of prostate cancer. It has been shown that AR exert their effects mainly through the androgen-activated AR which binds to androgen response elements (AREs) in the regulatory regions of target genes to regulate the transcription of androgen-responsive genes, thus, identification of AR downstream target gene is critical to understand androgen function in prostate cancer. In this study, our results showed that androgen treatment of LNCaP cells induced PTTG1 expression, which was blocked by the androgen receptor antagonist, Casodex. Bioinformatics analysis and experiments using PTTG1 promoter deletion mutants showed that the PTTG1 promoter contains a putative androgen response element (ARE), which localizes in the -851 to -836 region of the promoter. Androgen activated androgen receptor (AR) binding to this ARE was confirmed by Chromatin immunoprecipitation (ChIP) assay. Furthermore, Knockdown of PTTG1 expression using short hairpin RNA significantly reduced androgen-induced LNCaP cell growth and invasion. In addition, we showed PTTG1 is highly expressed in metastasis prostate cancer tissue. These results suggest that PTTG1 is a novel downstream target gene of androgen receptor and take part in prostate cancer proliferation and metastasis.

Effects of a proteasome inhibitor on the NF-κB signalling pathway in experimental osteoarthritis

OBJECTIVES

To evaluate the effects of the proteasome inhibitor MG-132 on the expression of nuclear factor (NF)-κB p65, inhibitor (I)-κB, tumour necrosis factor (TNF)-α, and interleukin (IL)-1β in the cartilage and synovial tissues of rats with osteoarthritis (OA), and to investigate the role that the ubiquitin/proteasome system (UPS) plays in the OA process.

METHOD

A total of 144 adult male Sprague Dawley rats were randomly assigned to four groups: anterior cruciate ligament transaction (ACLT) + MG-132 (ACLT/M), ACLT + dimethylsulfoxide (ACLT/D), sham surgery (Sham), and naïve + MG-132 (naïve/M). Pathological morphology was undertaken. mRNA expression levels of NF-κB p65, I-κB, TNF-α, and IL-1β were determined using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The activities of the 20S proteasome chymotrypsin-like and peptidylglutamyl-peptide hydrolase-like enzymes were measured using fluorospectrophotometry.

RESULTS

The Mankin scores at all time points in ACLT/M rats were significantly lower than those in ACLT/D rats (p < 0.05). Despite the NF-κB p65 in the synovial tissue at 2 weeks after surgery and IL-1β in the cartilage tissue at 12 weeks after surgery, mRNA expression levels of NF-κB p65, IL-1β, and TNF-α at other time points in ACLT/M were significantly lower than those in ACLT/D (p < 0.05). mRNA levels of I-κB in the cartilage tissue in ACLT/M were significantly higher than those in ACLT/D at 2 weeks after surgery (p < 0.05). mRNA levels of I-κB in the synovial tissue in ACLT/M were higher than those in ACLT/D at all time points, and the difference was significant at 4 weeks after surgery (p < 0.05). MG-132 decreased the activities of the 20S proteasome chymotrypsin-like and peptidylglutamyl-peptide hydrolase-like enzymes in the cartilage and synovial tissues of rats.

CONCLUSIONS

The proteasome inhibitor MG-132 delays the progress of OA by alleviating synovial inflammation and protecting the articular cartilage tissue.

ELL is an HIF-1alpha partner that regulates and responds to hypoxia response in PC3 cells

BACKGROUND

Eleven-nineteen lysine-rich leukemia (ELL) plays an important role in tumorigenesis and animal development. HIF-1 is a transcriptional factor that functions as a master regulator of O(2) homeostasis. Our previous studies showed that a binding partner of ELL, U19/Eaf2, can modulate HIF-1alpha activity and hypoxia response, suggesting that ELL may also influence HIF-1alpha pathway and hypoxia response.

METHODS

Co-localization and co-immunoprecipitation were performed to test the interaction between ELL and HIF-1alpha. PC3 cells with stable ELL knockdown and PC3 cells with stable ELL overexpression, along with their controls, were established using lentiviral expression system. Western blot and real-time PCR were performed to test the effect of ELL on HIF-1alpha protein and its down-stream gene transcription. To elucidate potential effect of hypoxia on ELL, cell growth and colony formation assays were performed using PC3 subline with stable ELL overexpression.

RESULTS

ELL is associated with HIF-1alpha in transfected cells. In PC3 prostate cancer cells, ELL inhibited HIF-1alpha protein level and down-stream gene expression. As expected, ELL inhibited cell growth and colony formation under normoxia. Interestingly, the inhibition was alleviated under hypoxia.

CONCLUSIONS

Our findings suggest that ELL and HIF-1alpha are binding partners and can modulate the functions of each other in hypoxia.

Phytoestrogens from Psoralea corylifolia reveal estrogen receptor-subtype selectivity

The seed of Psoralea corylifolia L. (PCL), a well-known traditional Chinese medicine, has been applied as a tonic or an aphrodisiac agent and commonly used as a remedy for bone fracture, osteomalacia and osteoporosis in China. In our study, the estrogen receptor subtype-selective activities of the extracts and compounds derived from PCL were analyzed using the HeLa cell assay. The different fractions including petroleum ether, CH(2)Cl(2) and EtOAc fractions of the EtOH extract of PCL showed significant activity in activating either ERalpha or ERbeta whereas the n-BuOH fraction showed no estrogenic activity. Further chromatographic purification of the active fractions yielded seven compounds including the two coumarins isopsoralen and psoralen, the four flavonoids isobavachalcone, bavachin, corylifol A and neobavaisoflavone, and the meroterpene phenol, bakuchiol. In reporter gene assay, the two coumarins (10(-8)-10(-5)M) acted as ERalpha-selective agonists while the other compounds (10(-9)-10(-6)M) activated both ERalpha and ERbeta. The estrogenic activities of all compounds could be completely suppressed by the pure estrogen antagonist, ICI 182,780, suggesting that the compounds exert their activities through ER. Only psoralen and isopsoralen as ERalpha agonists promoted MCF-7 cell proliferation significantly. Although all the compounds have estrogenic activity, they may exert different biological effects. In conclusion, both ER subtype-selective and nonselective activities in compounds derived from PCL suggested that PCL could be a new source for selective estrogen-receptor modulators.

Changes in the androgen levels in the ventral prostate of spontaneously hypertensive rats after castration

OBJECTIVE

To characterize the changes in androgen levels in the prostate after castration, as androgens are critical in the progression of prostate cancer after castration, but the time at which the androgen remaining in the prostatic cancer tissue after castration exerts its effects is poorly understood.

MATERIALS AND METHODS

The ventral prostate (VP) in adult male spontaneously hypertensive rats was excised at 2, 4 and 8 h, 1, 2, 4 and 7 days, and 2, 4 and 8 weeks after castration. The dihydrotestosterone (DHT), testosterone, dehydroepiandrosterone (DHEA) and androstenedione (4-dione) levels in the VP were measured simultaneously using gas chromatography/tandem mass spectrometry.

RESULTS

Within 2 days of castration, the DHT and testosterone levels in the VP decreased sharply, while there were no significant changes in the DHEA or 4-dione levels. From 2 days to 2 weeks after castration (2-7 days for 4-dione), there was a sharp peak in tissue androgen levels in the VP (P < 0.05 for all androgens); during the subsequent 6 weeks after castration, all of the tissue DHT, testosterone, DHEA and 4-dione levels gradually increased with time.

CONCLUSIONS

These data show the changes which occur in androgen levels in rat VP after castration and support the concept that the adrenal glands compensate for the loss of testicular androgen.

The important anti-apoptotic role and its regulation mechanism of PTTG1 in UV-induced apoptosis

Pituitary tumor transforming gene (PTTG1) is widely detected in many tumors. Increasing evidence reveals that PTTG1 is associated with cell proliferation, cellular transformation and apoptosis. However, the functions of PTTG1, especially its role in DNA damage-induced apoptosis, remain largely unclear. In this report, we used UV irradiation to induce apoptosis in HeLa cells to examine the role of PTTG1 in UV-induced apoptosis by RNAi-mediated knockdown and overexpression of PTTG1. RNAi-mediated knockdown of PTTG1 expression increased and overexpression of PTTG1 decreased the UV-induced apoptosis. Furthermore, UV irradiation decreased PTTG1 mRNA and protein expression. These effects were found to be mediated by JNK pathway. Therefore, PTTG1 had an important anti-apoptotic role in UV-induced apoptosis and this role was mediated by JNK pathway. These results may provide important information for understanding the exact role and the regulation mechanism of PTTG1 in UV-induced apoptosis.

Prognostic significance of Id-1 and its association with EGFR in renal cell cancer

AIMS

Epidermal growth factor receptor (EGFR) is suggested as one of the positive regulators in the invasive progression of renal cell cancer (RCC). Recently, Id-1 (inhibitor of differentiation or DNA binding), a helix-loop-helix transcription factor, has been identified as one of the key factors in the EGFR signalling pathway. The aim of this study was to investigate the significance of Id-1 expression in renal cell cancer and to study its relationship with EGFR.

METHODS AND RESULTS

Id-1 and EGFR expression was examined in tissue microarray (TMA) samples of 107 RCC and 32 normal kidney specimens by immunohistochemistry. Relative Id-1 and EGFR protein expression was quantified by estimating the staining intensity on a four-grade scale. We found that while negative to weak expression of Id-1 and EGFR was observed in non-malignant kidney tissues, most RCCs showed significant positive Id-1 and EGFR expression in tumour cells. In addition, Id-1 immunostaining intensity was positively associated with increased tumour staging, grading and EGFR expression.

CONCLUSION

Overexpression of Id-1 is a novel marker for advanced RCC which is positively correlated with EGFR expression. Our results suggest that Id-1 may play an important role in the development of RCC and indicate that Id-1 is a potential marker of patients with a poor prognosis.

Significance of TWIST expression and its association with E-cadherin in bladder cancer

Recently, TWIST, a basic helix-loop-helix transcription factor, has been reported to play a key role in the metastatic progression of several types of human cancer. The aim of this study was to investigate the significance of TWIST expression in bladder cancer using tissue microassays generated from 226 bladder tissue specimens. Using immunohistochemical staining, we studied TWIST expression levels in nonmalignant bladder tissues (n = 37), primary bladder cancer tissues (n = 164), and 25 cases of matched lymph node metastatic lesions. The association between TWIST expression levels and tumor staging and grading, as well as metastatic potential, was analyzed by statistical analysis. Our results showed that TWIST protein expression was significantly higher in bladder cancer specimens compared with nonmalignant tissues (P < .001), indicating its positive role in the development of bladder cancer. In addition, increased TWIST expression levels were associated with advanced-stage and high-grade tumors, suggesting its involvement in the progression of this cancer. Furthermore, TWIST expression was much higher in the metastatic lesion compared with its primary site (P < .05). More importantly, the increased TWIST expression in bladder cancer specimens was correlated with decreased membranous expression of E-cadherin, a cell adhesion molecule that plays a key role in the metastatic progression of human cancer. Our results demonstrate TWIST as a novel positive factor in the development and progression of bladder cancer and suggest a marker for advanced bladder cancer.

Aberrant methylation of the 8p22 tumor suppressor gene DLC1 in renal cell carcinoma

Epigenetic mechanisms involving DNA methylation and chromatin remodeling are important in silencing tumor suppressor genes (TSG) in various malignancies, including renal cell carcinoma (RCC). DLC1 (deleted in liver cancer 1)/ARHGAP7 is a recently identified 8p22 candidate TSG. Frequent methylation of the DLC1 promoter with resultant gene silencing has been reported in several tumors, but not in RCC yet. We examined DLC1 promoter methylation in 34 primary RCCs and the corresponding non-malignant tissues, and the correlation of DLC1 methylation with the clinicopathological characteristics of RCC patients. Although DLC1 methylation and downregulation were only detected in one of seven RCC cell lines using methylation-specific PCR (MSP) and semi-quantitative reverse-transcription PCR, we found that the DLC1 promoter was methylated in 35% (12/34) of primary RCC tumors, which was further confirmed by direct sequencing of MSP products and high-resolution bisulfite genomic sequencing. In contrast, only one of the 34 (3%) non-malignant renal tissues had weak methylation. Aberrant DLC1 methylation appeared to be a relatively early event during renal tumorigenesis since 33% of the RCC tumors with pT1 (TNM staging) showed methylation, which is similar to other late stage tumors. Thus, our results demonstrated that DLC1 methylation occurs in a subset of RCC tumors and may play a role in renal carcinogenesis.

The leader sequence triggers and enhances several functions of clusterin and is instrumental in the progression of human prostate cancer in vivo and in vitro

OBJECTIVE

To investigate the role of the leader sequence (which during clusterin biosynthesis facilitates its proper post-translational processing and secretion) in the functional activities of clusterin, a ubiquitous secretory glycoprotein with many biological functions, reported to be pro-apoptotic and anti-apoptotic in target cells, but for which the dual mechanism remains unclear.

MATERIALS AND METHODS

We designed an expression vector starting from the second in-frame ATG on the full-length human clusterin cDNA that was capable of driving the expression of both the full-length and the truncated isoforms of clusterin. We established stable expression clones of the androgen-dependent prostate cancer line LNCaP expressing clusterin with and without the leader sequence. This induced expression provided an opportunity to evaluate both the in vivo and in vitro actions of clusterin expression.

RESULTS

The LNCaP cells expressing clusterin with the leader sequence resisted apoptosis induced by tumour necrosis factor (TNF)-alpha, but clones with no leader sequence were highly susceptible to TNF-alpha-induced apoptosis. Furthermore, in the absence of the leader sequence, the expressed clusterin had a molecular weight consistent with that of the predicted holoprotein (40 kDa), suggesting a compromised post-translational processing with diffuse distribution throughout the cytoplasm. However, cells transfected with the full-length vector expressed clusterin of 60 and 35 kDa variants, and located exclusively in the Golgi apparatus. In vivo, only the overexpression of the full-length clusterin is anti-apoptotic and stimulates the proliferation of tumour.

CONCLUSION

The leader sequence is important in determining the functions of clusterin, which include anti-apoptotic and anti-necrotic properties. The lack of the leader sequence allowed the incompletely processed clusterin to induce apoptosis in target cells; without the leader sequence, clusterin functions differently. Thus, the leader sequence is a trigger for many functions of clusterin in the progression of human prostate cancer cells.

Significance of Id-1 up-regulation and its association with EGFR in bladder cancer cell invasion

Epidermal growth factor receptor (EGFR) is suggested to be one of the positive factors in the invasive progression of bladder cancer. Id-1 (inhibitor of differentiation or DNA binding), a helix-loop-helix (HLH) transcription factor, was recently identified as a key factor in the EGFR signalling pathway. The aim of this study was to investigate the role of Id-1 in bladder cancer progression and its relation-ship with EGFR. Using clinical specimens from different stages of bladder cancer, immunohistochemical staining was performed to determine if Id-1 expression was positively associated with tumour staging and EGFR expression. The direct role of Id-1 in cancer cell invasion was also investigated through ectopically expressing the Id-1 gene in a RT112 bladder cancer cell line by wound closure and collagen invasion assays. To explore the therapeutic potential of targeting the Id-1 gene in the treatment of invasive bladder cancer, we studied if inactivation of the Id-1 gene through small RNA interference could lead to the suppression of invasion in a MGHU1 bladder cancer cell line. Our results showed that the up-regulation of Id-1 was associated with increased EGFR expression, clinical staging and the invasion ability of bladder cancer cells. Inactivation of Id-1 may be a potential therapeutic target to inhibit the invasion by bladder cancer cells.

Significance of pituitary tumor transforming gene 1 (PTTG1) in prostate cancer

Recently, the pituitary tumor transforming gene 1 (PTTG1) has been suggested to be an oncogene. To investigate whether PTTG1 plays a positive role in the pathogenesis of prostate cancer, PTTG1 protein expression was examined in prostate tissue samples by immunohistochemistry. PTTG1 expression was detected in a high percentage of prostate cancer tissues (34/41, 82.9%), but to a much lesser extent in non-malignant tissues (5/14, 35.7%). To further confirm these results, the expression vectors containing either the PTTG1 or antisense-PTTG1 gene were transfected into a prostate cancer cell line, LNCaP, and the cell proliferation rate was studied, as well as tumorigenicity in the LNCaP cells expressing different levels of the PTTG1 protein. Ectopic PTTG1 gene expression promoted prostate cancer cell proliferation and tumorigenesis both in vitro and in nude mice. In contrast, down-regulation of PTTG1 led to suppression of tumor cell growth. These results suggest that PTTG1 may be a potential prognostic marker for prostate cancer and that the down-regulation of PTTG1 may be a therapeutic target in the suppression of prostate cancer growth.

HPtaa database-potential target genes for clinical diagnosis and immunotherapy of human carcinoma

Tumor-associated antigens (TAAs) have been the most actively employed targets in the clinical diagnosis and treatment of human carcinoma, such as PSA in the diagnosis of prostate cancer and NY-ESO-1 in the immunotherapy of melanoma and other cancers. However, identification of TAAs has often been hampered by the complicated and laborsome laboratory procedures. In order to accelerate the process of tumor antigen discovery, and thereby improve diagnosis and treatment of human carcinoma, we have made an effort to establish a publicly available Human Potential Tumor Associated Antigen database (HPtaa) with potential TAAs identified by in silico computing (). Tumor specificity was chosen as the core of tumor antigen evaluation, together with other relevant clues. Various platforms of gene expression, including microarray, expressed sequence tag and SAGE data, were processed and integrated by several penalty algorithms. A total of 3518 potential TAAs have been included in the database, which is freely available to academic users. As far as we know, this database is the first one addressing human potential TAAs, and the first one integrating various kinds of expression platforms for one purpose.

Androgen receptor coregulator ARA267-alpha interacts with death receptor-6 revealed by the yeast two-hybrid

ARA267-alpha is a newly identified androgen receptor coactivator. In order to further elucidate its precise role in cells, using the ARA267-alpha fragment containing four PHD and one SET conserved domains as bait we revealed an ARA267-alpha-PHD-SET-interacting protein, death receptor-6 (DR6), in the yeast two-hybrid screening. DR6 is the member of TNF receptor family and has a death domain in its intracellular cytoplasmic portion (DR6cp) to mediate the cell apoptosis. The interaction between ARA267-alpha-PHD-SET and DR6cp was confirmed in vitro and in vivo. Our finding implied that androgen signaling pathway might cross talk with apoptosis signaling pathway through the interaction between ARA267-alpha and DR6.

Identification of over-expressed genes in human renal cell carcinoma by combining suppression subtractive hybridization and cDNA library array

To isolate the over-expressed genes in human renal cell carcinoma (RCC) and analyze its molecular basis of carcinogenesis, we used the mRNA from human RCC tissues as tester and that from the matched normal kidney tissues as driver to construct the suppression subtractive hybridization library. 379 of the subtracted clones were arrayed onto a nylon membrane and the over-expressed genes were then screened by hybridizing the filter with radioactively labeled cDNA from RCC and matched normal kidney tissues. 67 clones over-expressed in RCC by a factor of 6 or more were sequenced and its identities were analyzed in GenBank database. 4 clones were previously unknown fragments and 2 clones represent KIAA genes. The rest clones were the known genes and some of them were RCC-related, including vascular endothelial growth factor, vimentin and tissue factor. Most of the known genes were the RCC-related genes previously unknown, including zinc ribbon domain-containing 1 protein (ZNRD1), pituitary tumor transforming gene1 (PTTG1). Northern blot and semi-quantitative RT-PCR confirmed that the mRNA levels of the 3 novel fragments and 1 KIAA and 3 known genes were significantly higher in RCC than in the matched normal kidney tissues. Immunohistochemical and Western blot analysis for PTTG1 and ZNRD1 revealed increased protein level in RCC. The over-expressed genes in RCC are the potential molecular targets for diagnosis and therapy and it is very important to understand the molecular mechanism of RCC through the profile of over-expressed genes.

Morphology and physiology of the polyaxonal amacrine cells in the rabbit retina

We examined the morphology and physiological response properties of the axon-bearing, long-range amacrine cells in the rabbit retina. These so-called polyaxonal amacrine cells all displayed two distinct systems of processes: (1) a dendritic field composed of highly branched and relatively thick processes and (2) a more extended, often sparsely branched axonal arbor derived from multiple thin axons emitted from the soma or dendritic branches. However, we distinguished six morphological types of polyaxonal cells based on differences in the fine details of their soma/dendritic/axonal architecture, level of stratification within the inner plexiform layer (IPL), and tracer coupling patterns. These morphological types also showed clear differences in their light-evoked response activity. Three of the polyaxonal amacrine cell types showed on-off responses, whereas the remaining cells showed on-center responses; we did not encounter polyaxonal cells with off-center physiology. Polyaxonal cells respected the on/off sublamination scheme in that on-off cells maintained dendritic/axonal processes in both sublamina a and b of the IPL, whereas processes of on-center cells were restricted to sublamina b. All polyaxonal amacrine cell types displayed large somatic action potentials, but we found no evidence for low-amplitude dendritic spikes that have been reported for other classes of amacrine cell. The center-receptive fields of the polyaxonal cells were comparable to the diameter of their respective dendritic arbors and, thus, were significantly smaller than their extensive axonal fields. This correspondence between receptive and dendritic field size was seen even for cells showing extensive homotypic and/or heterotypic tracer coupling to neighboring neurons. These data suggest that all polyaxonal amacrine cells are polarized functionally into receptive dendritic and transmitting axonal zones.

Suppression subtractive hybridization for identifying differentially expressed genes in renal cell carcinoma

OBJECTIVE

To construct a renal cell carcinoma (RCC) cDNA subtractive library using suppression subtractive hybridization.

METHODS

Polyadenylated RNA [Poly (A)+ RNA] was isolated from tissues of RCC and normal kidney, and single-strand cDNAs and double-strand cDNAs were synthesized in turn. RCC cDNAs were divided into two groups and ligated to the specific adaptors I and 2, and then hybridized with normal kidney cDNA twice with two rounds of suppression PCR. Second round PCR products were cloned to T/A plasmid vectors to set up the subtractive library. One hundred clones were randomly picked to perform enzyme digest analysis, and some underwent sequence analysis and Northern blot to identify RCC specifically expressed genes. SMART RACE procedure was operated to clone full length novel RCC specifically expressed genes.

RESULTS

A human RCC subtractive library with high subtractive efficiency was successfully set up. The amplified library contains 350 positive clones. Random analysis of 100 clones with enzyme restriction showed that 85 plasmids in the clones contained 50-400 bp inserts. Sequence analysis was performed for 10 clones. All the 10 sequences were unknown before and derived from 6 unique, novel genes among which the cDNA insert RCC18 had five copies. Northern blot analysis showed that RCC18 cDNA was highly expressed in RCC, but no signal could be detected in normal kidney. Using SMART RACE technique, we obtained the full length of the novel gene RCC18.

CONCLUSIONS

The constructed cDNA subtractive library of human RCC is a highly efficient one and lays a solid foundation for large scale screening and cloning new and specific oncogenes or tumor suppressor genes of RCC. The novel specifically expressed genes provided an important clue for studying the mechanisms of occurrence and development of RCC.

[Frequent somatic mutations of the von Hippel-Lindau tumor suppressor gene in primary sporadic human renal clear cell carcinomas]

OBJECTIVE

To investigate the mutation of Von Hippel-Lndau (VHL) tumor suppressor gene in patients with primary sporadic human renal cell carcinoma (RCC).

METHODS

DNA samples from 20 primary sporadic renal clear carcinoma patients were analyzed by polymerase chain reaction, single strand conformational polymorphism analyses (PCR-SSCP) and direct sequencing.

RESULTS

Somatic mutations of the VHL gene were detected in 11 (55%) of the 20 clear cell renal carcinomas, including 6 deletions, 2 insertions, and 3 missense mutations. These mutations mainly occurred in the last one-third region of exon 1, 2 and 3 of the VHL gene.

CONCLUSION

The VHL gene may frequently mutate in Chinese patients with primary sporadic renal clear cell carcinoma. The VHL gene may be useful as a marker gene for the diagnosis of RCC and as a target gene for molecular therapy.

Expression of beta-catenin in renal cell carcinoma

OBJECTIVE

To investigate the expression of beta-catenin and its mRNA in renal cell carcinoma.

METHODS

Twenty-six cases with renal cell carcinoma (RCC) were studied by immunohistochemistry, Western blot and RT-PCR.

RESULTS

We found the expression of beta-catenis is higher in cancer tissues than in normal kidney tissues and the level of beta-catenin is associated with the tumor stage. Its expression in tumor of pT3 and pT4 is obviously higher than pT1 and pT2 (P < 0.01). That is to say, there was an overexpression of beta-catenin protein in RCC and its level was related to the tumor stage, but the expression of beta-catenin mRNA had no difference between tumor tissue and normal tissue.

CONCLUSION

beta-catenin may be related to the occurrence and progress of RCC.

[Cloning and identifying of renal cell carcinoma differentially expressed genes]

OBJECTIVE

To clone and identify RCC specially expressed genes different with normal kidney tissue.

METHODS

A technique called suppression subtractive hybridization was used to construct the library which contains the differently expressing cDNAs between RCC and normal kidney. Then the RCC specially expressed genes were cloned from it.

RESULTS

Human RCC subtractive library with high subtractive efficiency was set up successfully. The amplified library contains 350 positive clones. Sequence analysis was performed in 5 clones. All of the sequences were unknown before and the cDNA inserting GYLZ-RCC18 had three copies. Northern blot analysis showed that GYLZ-RCC18 cDNA expressed highly in RCC, but there was no any signal could be detected in normal kidney. Using SMART RACE technique, we obtained the full length of novel gene of GYLZ-RCC18. We also identified that GYLZ-RCC18 family contains 3 subtype genes.

CONCLUSIONS

The highly efficient cDNA subtractive library lays a solid foundation for screening and cloning new and specific oncogenes or tumor suppressor genes of RCC. The novel differentially expressed genes provide an important clue to studying the mechanism of the occurrence and development of RCC.

Effects of nitric oxide on horizontal cells in the rabbit retina

Retinal horizontal cells display large receptive fields as a result of extensive electrical coupling via gap junctions. There is abundant evidence that these gap junctions are dynamically regulated by changes in the adaptational state of the retina. The neuromodulator dopamine appears to play a major role in regulating gap junctional conductances of horizontal cells. Emerging evidence indicates that nitric oxide (NO) also acts as a neuromodulator in the retina and, more specifically, regulates the coupling between horizontal cells. In the present study, we examined the effects of a nitric oxide, and its secondary messenger cGMP, on electrical and tracer coupling between A-type and between B-type horizontal cells in the rabbit retina. Application of the NO donors S-nitroso-N-acetylpenicillamine (SNAP) or sodium nitroprusside (SNP) significantly reduced the coupling between horizontal cells as evidenced by a decrease in their space constants, annulus-to-small spot response ratios, and the extent of tracer coupling following injection with Neurobiotin. Further, application of SNP eliminated the increase in coupling of horizontal cells normally seen with exposure to dim background illumination. Application of 8-bromo-cGMP produced effects similar to those of the NO donors, consistent with the idea that the uncoupling actions of NO were mediated via a cGMP cascade. In addition, the NO donors and cGMP augmented the responsiveness of A- and B-type cells to both small and large spots of light. This augmentation appeared to be due to secondary effects on photoreceptor transduction and/or photoreceptor-to-horizontal cell synaptic efficacy that were distinct from the actions on gap junctions. Our results suggest that NO may mediate changes in coupling between horizontal cells related to the adaptational state of the mammalian retina.

Different Wnt-5A gene expressions in the renal cell carcinoma GRC-1 cell line during the cell cycle

OBJECTIVE

To investigate the gene expression at transcription level of growth factor Wnt-5A in different phase during the cell cycle.

METHODS

We synchronized the renal cell carcinoma GRC-1 cell line by double thymidine blocks and high-pressure N2O gae methods and amplified Wnt-5A cDNAs from different phase using Semi-quantitative RT-PCR (reverse transcriptase polymerase chain reaction). The PCR products were electrophoresized on the agrose gel and detected by Gel Doc 1000 computer controlled system integrating the volumes of each band, representing the intensities of all pixels in a defined band.

RESULTS

The different mRNA expressions of growth factor Wnt-5A was detected in RCC GRC-1 cell line. In S phase, the highest level of Wnt-5A transcript was observed, and in G1 and M phase, medial and lowest, respectively. The differences between S and M stages were statistically significant (P < 0.05).

CONCLUSION

Growth factor Wnt-5A has the potential effect on tumorigenesis. It contributes to all phases during cell cycle but in S phase especially.

Surround inhibition of mammalian AII amacrine cells is generated in the proximal retina

1. Intracellular recordings were obtained from neurons in the superfused retina-eyecup preparation of the rabbit under dark-adapted conditions. Neurotransmitter agonists and antagonists were applied exogenously via the superfusate to dissect the synaptic pathways pharmacologically and thereby determine those pathways responsible for the generation of the on-centre/off-surround receptive fields of AII amacrine cells. 2. Application of the metabotropic glutamate receptor agonist, APB, reversibly blocked both the on-centre and off-surround responses of AII cells. These data were consistent with the idea that both the centre- and surround-mediated responses are derived from inputs from the presynaptic rod bipolar cells. 3. Whereas rod bipolar cells showed on-receptive fields approximately 100 microm across, we found no evidence for an antagonistic off-surround response using light stimuli which effectively elicited the off-surrounds of AII amacrine cells. These results indicated that the surrounds of AII cells are not derived from rod bipolar cell inputs. 4. Application of the ionotropic glutamate receptor antagonists CNQX or DNQX enhanced the on-centre responses of AII cells but attenuated the off-surround responses. These data indicated that the centre- and surround-mediated responses could not both be derived from signals crossing the rod bipolar-to-AII cell synapse. 5. Application of the glycine antagonist, strychnine, had only minor and variable effects on AII cell responses. However, the GABA antagonists picrotoxin and bicuculline enhanced the on-centre response but attenuated or completely blocked the off-surround response of AII cells. The GABA antagonists had no effect on the responses of horizontal cells indicating that their effects on AII cell responses reflected actions on inner retinal circuitry rather than feedback circuitry in the outer plexiform layer. 6. Application of the voltage-gated sodium channel blocker TTX enhanced the on-centre responses of AII cells but attenuated or abolished their off-surround responses. 7. Taken together, our results suggest that the on-centre responses of AII cells result from the major excitatory drive from rod bipolar cells. However, the surround receptive fields of AII cells appear to be generated by lateral, inhibitory signals derived from neighbouring GABAergic, on-centre amacrine cells. A model is presented whereby the S1 amacrine cells produce the surround receptive fields of AII amacrine cells via inhibitory, feedback circuitry to the axon terminals of rod bipolar cells.

[Beta-catenin and its mRNA in renal cell carcinoma]

OBJECTIVES

To investigate the role of beta-catenin in renal cell carcinoma.

METHODS

The expression of beta-catenin in 26 cases of renal cell carcinoma was studied by LSAB immunohistochemistry, Western blotting and RT-PCR.

RESULTS

The expression of beta-catenin was higher in cancer tissues than in normal kidney tissues in 25 cases and the level of beta-catenin was associated with tumor stage. The expression was obviously higher in pT3 and pT4 than in pT1 and pT2 (P < 0.01). The expression of its mRNA was not higher in tumor cells than in normal cells. Beta-catenin was expressed mainly in cytoplasm.

CONCLUSIONS

Beta-catenin might be related to the occurrence and development of kidney tumor.

Cloning and sequencing of the rat cDNAs encoding class I beta-tubulin

Two kinds of rat cDNA clones encoding class I beta-tubulin were isolated from the neonatal rat brain, and sequenced. They corresponded to mRNA species formed by the alternative usage of polyadenylation signals. The determined nucleotide sequence showed high (84.6%) identity to rat class II beta-tubulin, the only rat beta-tubulin sequence reported in the nucleotide database, in the coding region, but relatively low (47.3-50.7%) in the noncoding region. The Northern blot analysis using the 3'-noncoding fragment as a probe showed that both mRNA species of the class I beta-tubulin were down-regulated during brain development.

Comparison of the responses of AII amacrine cells in the dark- and light-adapted rabbit retina

We studied the light-evoked responses of AII amacrine cells in the rabbit retina under dark- and light-adapted conditions. In contrast to the results of previous studies, we found that AII cells display robust responses to light over a 6-7 log unit intensity range, well beyond the operating range of rod photoreceptors. Under dark adaptation, AII cells showed an ON-center/OFF-surround receptive-field organization. The intensity-response profile of the center-mediated response component followed a dual-limbed sigmoidal function indicating a transition from rod to cone mediation as stimulus intensities were increased. Following light adaptation, the receptive-field organization of AII cells changed dramatically. Light-adapted AII cells showed both ON- and OFF-responses to stimulation of the center receptive field, but we found no evidence for an antagonistic surround. Interestingly, the OFF-center response appeared first following rapid light adaptation and was then replaced gradually over a 1-4 min period by the emerging ON-center response component. Application of the metabotropic glutamate receptor agonist APB, the ionotropic glutamate blocker CNQX, 8-bromo-cGMP, and the nitric oxide donor SNAP all showed differential effects on the various center-mediated responses displayed by dark- and light-adapted AII cells. Taken together, these pharmacological results indicated that different synaptic circuits are responsible for the generation of the different AII cell responses. Specifically, the rod-driven ON-center responses are apparently derived from rod bipolar cell synaptic inputs, whereas the cone-driven ON-center responses arise from signals crossing the gap junctions between AII cells and ON-center cone bipolar cells. Additionally, the OFF-center response of light-adapted AII cells reflects direct synaptic inputs from OFF-center cone bipolar cells to AII dendritic processes in the distal inner plexiform layer.

Dark- and light-induced changes in coupling between horizontal cells in mammalian retina

Retinal horizontal cells exhibit large receptive fields derived from their extensive electrical coupling by means of gap junctions. The conductance of these gap junctions seems to be regulated by dopamine acting through a cAMP-mediated cascade. There is now abundant evidence that extracellular dopamine levels vary with changes in ambient light intensity, suggesting that changes in the dark/light adaptational state of the retina can modulate coupling between horizontal cells. We studied this question in the mammalian retina by determining the effects of ambient light levels, in the form of changing background light intensity, on the coupling profiles of A- and B-type horizontal cells in the rabbit. Changes in coupling were assessed by measurements of the space constants of the syncytium formed by horizontal cells and the intercellular spread of the biotinylated tracer Neurobiotin. Our results indicate that dark-adapted horizontal cells show relatively weak coupling. However, presentation of background lights as dim as one-quarter log unit above rod threshold resulted in increases in both the averaged extent of tracer coupling and space constants of A- and B-type horizontal cells. Coupling expanded further as background light intensities were increased by 1-1.5 log units, after which additional light adaptation brought about an uncoupling of cells. Coupling reached its minimum at light intensities about 3 log units above rod threshold, after which, with further light adaptation, it stabilized at levels close to those seen in dark-adapted retinas. Our results indicate that electrical coupling between mammalian horizontal cells is modulated dramatically by changes in the adaptational state of the retina: coupling is maximized under dim ambient light conditions and diminishes as the retina is dark or light adapted from this level.

Effect of verbascoside on decreasing concentration of oxygen free radicals and lipid peroxidation in skeletal muscle

AIM

To detect the effects of verbascoside on decreasing the concentration of oxygen free radicals (OFR) and lipid peroxidation in skeletal muscle resulting from exhaustive exercise.

METHODS

Electron spin resonance (ESR) technique and thiobarbituric acid reaction (TBAR) method were used to detect the concentration of OFR in intact gastrocnemius muscle and the contents of milondialdehyde (MDA) in muscle homogenate.

RESULTS

Verbascoside decreased the concentration of OFR (P < 0.05) and the level of lipid peroxidation (P < 0.05) in muscle caused by exercise.

CONCLUSION

Verbascoside has the effects of reducing oxidative stress in muscle caused by exhaustive exercise by decreasing the concentration of free radicals and the level of lipid peroxidation.

[Investigation of factors affecting the development of COPD]

OBJECTIVE

To investigate the factors which affect the development of COPD.

METHODS

88 patients with mPAP less than 20 mm Hg were followed up by 5 - 20 years. Pulmonary ventilation, blood gas analysis, ECG, pulmonary hemodynamic parameters and oxygen saturation at night were performed one time every 5 years.

RESULTS

The results showed that: 5 year, 10 year and 20 year's mortality is 6%, 25% and 43% respectively; MVV%, FEV(1)% and PaO(2) declined accompanied by the increase of PaCO(2); among 41 patients with mPAP 16 - 20 mm Hg, 20 patients' mPAP were more than 20 mm Hg and 15 patients died after 10 years' follow up. Among 16 patients with the declination of oxygen saturation, 8 patients' mPAP were more than 20 mm Hg and 6 patients died. 57 strains of infectious bacteria were found in 88 patients' sputum with 43 strains in the death group.

CONCLUSIONS

These results demonstrated that COPD is a kind of chronic diseases with high death rate; infection, decline of oxygen saturation at night and mPAP more than 16 mm Hg were high risk factors in COPD.