Biomedical subjects

Chen Zhong

Publications and source records attributed to Chen Zhong.

9 recordsLinked to original sources

PubMed2026

Exploring shared biomarkers and their mechanisms in thyroid cancer and systemic lupus erythematosus via bioinformatics analysis.

BACKGROUND: Systemic lupus erythematosus (SLE), an autoimmune disorder, is linked to a heightened risk of multiple malignancies, including thyroid cancer. Thyroid cancer is the most prevalent malignancy of the endocrine system, and its autoimmune-related pathological features render it an optimal subject for investigating the mechanisms of their comorbidity. The molecular mechanisms underlying this comorbidity are still ambiguous. The accurate diagnosis and treatment of thyroid cancer urgently necessitate innovative molecular targets that extend beyond conventional pathological characteristics. This study seeks to employ integrated bioinformatics approaches to elucidate potential shared molecular mechanisms and immunological features between thyroid cancer and systemic lupus erythematosus (SLE), aiming to enhance understanding of their comorbidity and identify novel intervention targets. METHODS: This study initially acquired gene expression data for TC and SLE from the GEO database and subsequently screened and identified differentially expressed genes (DEGs) shared by both diseases. Subsequently, we conducted Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome functional enrichment analyses on these 46 shared differentially expressed genes (DEGs) and further assessed the activation status of pertinent pathways using Gene Set Enrichment Analysis (GSEA). Subsequently, we employed CIBERSORTx to examine immune infiltration patterns and developed protein-protein interaction networks utilising the STRING database. We identified hub genes utilising the MCODE and cytoHubba plugins and visualised the findings with Cytoscape software. We additionally assessed the diagnostic efficacy of these core hub genes in an independent dataset utilising ROC curves and investigated their prognostic relevance in thyroid cancer through Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression. Ultimately, we employed the Network Analyst platform to forecast transcription factor-gene and miRNA-gene regulatory networks and identified potential targeted therapeutic compounds utilising the DSigDB database. RESULTS: This study identified 46 differentially expressed genes (DEGs) commonly linked to thyroid cancer and systemic lupus erythematosus (SLE), which were significantly enriched in signalling pathways associated with immune-inflammatory activation, type I interferon responses, and complement pathway activation. Moreover, GSEA findings validated that immune-inflammatory and autoimmune-related pathways are markedly activated in both conditions. Twelve hub genes were discerned through protein-protein interaction networks. Analysis of immune infiltration indicated that thyroid cancer and systemic lupus erythematosus exhibit a shared characteristic of innate immune dysregulation, marked by the infiltration of myeloid cells (neutrophils, M0/M2 macrophages). Receiver operating characteristic (ROC) curve analysis identified six significant core hub genes with substantial diagnostic value: C1QB, LCN2, C1QC, LTF, VSIG4, and C3AR1. Univariate survival analysis indicated that elevated expression of C1QC and C3AR1 significantly enhances overall survival in thyroid cancer patients; however, multivariate COX regression analysis revealed that their independent prognostic significance necessitates further validation. This study predicted the interaction networks of transcription factors and miRNAs regulating key genes, with LCN2 demonstrating the highest connectivity to miRNAs, and identified candidate therapeutic compounds linked to it. CONCLUSION: This study employed bioinformatics analysis to identify critical shared hub genes and molecular pathways connecting thyroid cancer and systemic lupus erythematosus, offering novel insights into their shared pathogenesis and the advancement of targeted biomarkers and therapeutic strategies.

Bioinformatics analysis↗

PubMed2006

Crystal structures of human NUDT5 reveal insights into the structural basis of the substrate specificity.

Human NUDT5 (hNUDT5) is an ADP-ribose pyrophosphatase (ADPRase) belonging to the Nudix hydrolase superfamily. It presumably plays important roles in controlling the intracellular level of ADP-ribose (ADPR) to prevent non-enzymatic ADP-ribosylation by hydrolyzing ADPR to AMP and ribose 5'-phosphate. We report here the crystal structures of hNUDT5 in apo form, in complex with ADPR, and in complex with AMP with bound Mg2+. hNUDT5 forms a homodimer with substantial domain swapping and assumes a structure more similar to Escherichia coli ADPRase ORF209 than human ADPRase NUDT9. The adenine moiety of the substrates is specifically recognized by the enzyme via hydrogen-bonding interactions between N1 and N6 of the base and Glu47 of one subunit, and between N7 of the base and Arg51 of the other subunit, providing the molecular basis for the high selectivity of hNUDT5 for ADP-sugars over other sugar nucleotides. Structural comparisons with E. coli ADPRase ORF209 and ADPXase ORF186 indicate that the existence of an aromatic residue on loop L8 in ORF186 seems to be positively correlated with its enzymatic activity on APnA, whereas hNUDT5 and ORF209 contain no such residue and thus have low or no activities on APnA.

Adenosine Diphosphate Ribose↗

PubMed2006

Cooperation between FGF8b overexpression and PTEN deficiency in prostate tumorigenesis.

Two commonly occurring genetic aberrations of human prostate cancer [i.e., overexpression of a mitogenic polypeptide (fibroblast growth factor 8, isoform b or FGF8b) and loss of function of PTEN tumor suppressor] were recapitulated into a new combinatorial mouse model. This model harboring the Fgf8b transgene and haploinsufficiency in Pten, both in a prostate epithelium-specific manner, yielded prostatic adenocarcinoma with readily detectable lymph node metastases, whereas single models with each of the defects were shown earlier to progress generally only up to prostatic intraepithelial neoplasia (PIN). In addition to late age-related development of typical adenocarcinoma, the model also displayed a low incidence of mucinous adenocarcinoma, a rare variant type of human prostatic adenocarcinoma. The cooperation between FGF8b activation and PTEN deficiency must be linked to acquisition of additional genetic alterations for the progression of the lesions to primary adenocarcinoma. Here, we identified loss of heterozygosity at the Pten gene leading to bialleic loss, as a necessary secondary event, indicating that a complete loss of PTEN function is required in the development of invasive cancer in the model. Analyses of expression of downstream mediators phospho-AKT (p-AKT) and p27(KIP1), in various types of lesions, however, revealed a complex picture. Although PIN lesions displayed relatively strong expression of p-AKT and p27(KIP1), there was a notable heterogeneity with variable decrease in their immunostaining in adenocarcinomas. Together, the results further underscore the notion that besides activation of AKT by loss of PTEN function, other PTEN-regulated pathways must be operative for progression of lesions from PIN to adenocarcinoma.

Adenocarcinoma↗

PubMed2006

Increased expression of osteopontin contributes to the progression of prostate cancer.

Osteopontin is a secreted glycosylated phosphoprotein known to be involved in numerous physiologic functions and associated with the late stages of various cancers. We used preneoplastic and neoplastic mouse models of prostate cancer to determine the onset of elevated expression of osteopontin in the development of this disease. Osteopontin alterations occurred early in the disease with dysregulated expression observed in lesions of low-grade prostatic intraepithelial neoplasia (PIN). Over time, osteopontin expressing dysplastic cells seemed to increase in number in high-grade PIN and increased further in adenocarcinoma, and in metastasis, almost all of the cancer cells immunohistochemically stained positive for osteopontin overexpression. We examined the biological properties of human prostate cancer cell lines LNCaP and PC-3, in which osteopontin overexpression was achieved via lentiviral gene transduction. Evidence was obtained that osteopontin could contribute to a proliferative advantage in both cell types, although more significantly in LNCaP than PC-3. Osteopontin also influenced their in vitro invasive ability, and again, most strikingly in the weakly oncogenic LNCaP. Furthermore, excess osteopontin induced the LNCaP cells to acquire a strong intravasation potential in vivo in the chicken embryo chorioallantoic membrane assay for blood vessel penetration. These results establish a correlation between an increased gradient of osteopontin expression throughout the stages of murine prostate cancer, beginning from the preneoplastic lesions to distant metastases that suggests a proliferative and invasive advantages to those prostate tumor cells overexpressing osteopontin. Together, these findings support a strategy designed to target osteopontin in the context of prostate cancer therapy.

Adenocarcinoma↗

PubMed2005

Diverse biological effect and Smad signaling of bone morphogenetic protein 7 in prostate tumor cells.

We found that bone morphogenetic protein (BMP) 7, a member of the BMP family, was strikingly up-regulated during the development of primary prostatic adenocarcinoma in the conditional Pten deletion mouse model. To determine the relevance of this finding to human prostate cancer, we examined the expression of BMPs and BMP receptors (BMPR) as well as the responsiveness to recombinant human BMP7 in a series of human prostate tumor cell lines. All prostatic cell lines tested expressed variable levels of BMP2, BMP4, and BMP7 and at least two of each type I and II BMPRs. In all cases, BMP7 induced Smad phosphorylation in a dose-dependent manner, with Smad5 activation clearly demonstrable. However, the biological responses to BMP7 were cell type specific. BPH-1, a cell line representing benign prostatic epithelial hyperplasia, was growth arrested at G1. In the bone metastasis-derived PC-3 prostate cancer cells, BMP7 induced epithelial-mesenchymal transdifferentiation with classic changes in morphology, motility, invasiveness, and molecular markers. Finally, BMP7 inhibited serum starvation-induced apoptosis in the LNCaP prostate cancer cell line and more remarkably in its bone metastatic variant C4-2B line. Each of the cell lines influenced by BMP7 was also responsive to BMP2 in a corresponding manner. The antiapoptotic activity of BMP7 in the LNCaP and C4-2B cell lines was not associated with a significant alteration in the levels of the proapoptotic protein Bax or the antiapoptotic proteins Bcl-2, Bcl-xl, and X-linked inhibitor of apoptosis. However, in C4-2B cells but not in LNCaP cells, a starvation-induced decrease in the level of survivin was counteracted by BMP7. Taken together, these findings suggest that BMPs are able to modulate the biological behavior of prostate tumor cells in diverse and cell type-specific manner and point to certain mechanisms by which these secreted signaling molecules may contribute to prostate cancer growth and metastasis.

Adenocarcinoma↗

PubMed2005

EphB4 expression and biological significance in prostate cancer.

Prostate cancer is the most common cancer in men. Advanced prostate cancer spreading beyond the gland is incurable. Identifying factors that regulate the spread of tumor into the regional nodes and distant sites would guide the development of novel diagnostic, prognostic, and therapeutic targets. The aim of our study was to examine the expression and biological role of EphB4 in prostate cancer. EphB4 mRNA is expressed in 64 of 72 (89%) prostate tumor tissues assessed. EphB4 protein expression is found in the majority (41 of 62, 66%) of tumors, and 3 of 20 (15%) normal prostate tissues. Little or no expression was observed in benign prostate epithelial cell line, but EphB4 was expressed in all prostate cancer cell lines to varying degrees. EphB4 protein levels are high in the PC3 prostate cancer cell line and several folds higher in a metastatic clone of PC3 (PC3M) where overexpression was accompanied by EphB4 gene amplification. EphB4 expression is induced by loss of PTEN, p53, and induced by epidermal growth factor/epidermal growth factor receptor and insulin-like growth factor-I/insulin-like growth factor-IR. Knockdown of the EphB4 protein using EphB4 short interfering RNA or antisense oligodeoxynucleotide significantly inhibits cell growth/viability, migration, and invasion, and induces apoptosis in prostate cancer cell lines. Antisense oligodeoxynucleotide targeting EphB4 in vivo showed antitumor activity in murine human tumor xenograft model. These data show a role for EphB4 in prostate cancer and provide a rationale to study EphB4 for diagnostic, prognostic, and therapeutic applications.

Animals↗

PubMed2004

Retroperitoneoscopic subcapsular nephrectomy for infective nonfunctioning kidney with dense perinephric adhesions.

OBJECTIVE: To evaluate the feasibility and clinical efficacy of retroperitoneoscopic subcapsular nephrectomy for infective nonfunctioning kidneys with dense perinephric adhesions. PATIENTS AND METHODS: Twelve patients underwent retroperitoneoscopic subcapsular nephrectomy; the operative duration, blood loss, intestinal functional recovery time, complications during surgery and efficacy were recorded. Dissociation and ligation of the renal pedicle was the most important step, at which the renal capsule was cut near the renal hilum using a harmonic scalpel, and the fatty tissue around the renal hilum dissected carefully. The renal pedicle was then ligated and divided using an endoscopic linear stapler-cutter after the renal pedicle tissues had been separated to an adequate thickness. RESULTS: All 12 operations were successful and none required conversion to open surgery. The mean (SD, range) operative duration was 82.9 (22.3, 45-120) min, the blood loss 51.4 (12.2, 30-75) mL and the intestinal functional recovery time 12-48 h. There were no complications during or after the surgery, and in the follow-up of 1-15 months the short-term results were satisfactory. CONCLUSION: Retroperitoneoscopic subcapsular nephrectomy can be used safely to remove an infected and heavily adhesive nonfunctioning kidney, with minimal trauma and blood loss, and with faster recovery than after an open subcapsular nephrectomy.

Adult↗

PubMedDate not supplied

Aberration in the expression of the retinoid receptor, RXRalpha, in prostate cancer.

There is ample evidence for a role for retinoids in the development and maturation of prostatic epithelium. In recent experiments with conditional disruption of a specific retinoid receptor, namely, RXRalpha in the prostatic epithelium of the mouse, we observed that a major component of retinoid action in the prostate is indeed mediated by RXRalpha. The results clearly indicated that the inactivation of RXRalpha in the prostate epithelium leads to the development of preneoplastic lesions (Huang et al. Cancer Res 62: 4812-9, 2002). To determine the relation of this finding to human prostate cancer, we examined the expression of RXRalpha protein in human prostate cancer cell lines by western blotting and prostate cancer specimens by immunohistochemistry. Relative to the "normal" prostate epithelial cells, there was approximately two- to nine-fold decrease in the full-length 54 kD RXRalpha protein in each of the seven different prostate cancer cell lines tested. Similarly, while RXRalpha immunostaining was uniformly strong in the nuclei of most of the benign prostatic epithelial cells of the thirteen adenocarcinoma specimens tested, a highly heterogeneous pattern of expression was detected in the malignant epithelium, with some areas with low or no staining, others with mostly cytoplasmic staining, and some with both nuclear and cytoplasmic immunoreactivity. To evaluate the effect of RXRalpha modulation on the biologic properties of prostate cancer cell lines, we used a lentivirus expression system to overexpress RXRalpha in CWR22R prostate cancer cells that basally expressed a marginal level of the receptor. The sorted RXRalpha-transduced cells were compared to the corresponding vector control cells for proliferative and apoptotic properties. A correlation of reduction of cell growth or increased susceptibility to apoptosis with increases in the level of RXRalpha nuclear receptor was demonstrated. These effects were further enhanced when the cell culture medium was supplemented with a retinoid receptor panagonist, 9-cis retinoic acid. Together, these data support the notion that, like in mouse prostate, loss or reduction of RXRalpha activity might be a critical factor in prostate tumorigenesis in humans.

Alitretinoin↗

PubMedDate not supplied

A potential therapeutic strategy to combat leukemia virus infection.

To test the concept that a replication-competent retrovirus carrying a suicide gene could have potential utility in the control of the natural virus infection in mammalian species, we constructed derivatives of a feline leukemia virus (FeLV) that is commonly associated with leukemia-lymphomas in this species. The FeLV, Rickard strain, subgroup A (FRA) genome contained at the 3' end of the envgene, an insert of an internal ribosomal entry site (IRES) linked to cDNA sequence of either herpes simplex virus thymidine kinase (HSV-TK) or a truncated HSV-TK (HSV-ATK) or yeast cytosine deaminase (CD). These constructs were transfected into feline fibroblast cells (H927). The viruses produced were determined to be replication-competent. The stable propagation of the full-length transgene was, however, dependent on the size of the insert, IRES-CD being the smallest in size (1031 bp) exhibiting maximal stability for at least up to six months. The protein products of the transgenes could be detected, despite the appearance of deleted proviruses at late passages. The transduced cells were susceptible to cytotoxic killing when the appropriate prodrug, ganciclovir (GCV), acyclovir (ACV) or 5-fluorocytosine (5-FC) was added to the culture medium. H927 cells, infected with another subgroup of FeLV, namely, FeLV-B or FeLV-C, could be superinfected by the FRA-suicide gene viruses and thus, subjected to killing. Interestingly, at an early stage of infection by the parental FRA, H927 cells could also be reinfected by the same subgroup FRA constructs to induce the suicide effect. Among the three constructs, the vector with the CD gene was determined to be superior to others in terms of stability, therapeutic index and bystander effect in the cell culture test system. While the in vivo correlates of the therapeutic effect in the feline model remain to be determined, our results do encourage investigation of the same concept in the control of HTLV and, perhaps even, HIV infection in humans.

Acyclovir↗