Tetranectin expression in human colonic neoplasia

Insight into the function of tetranectin in human diseases: A review and prospects for tetranectin-targeted disease treatment

Tetranectin (TN), a serum protein, is closely associated with different types of cancers. TN binds plasminogen and promotes the proteolytic activation of plasminogen into plasmin, which suggests that TN is involved in remodeling the extracellular matrix and cancer tissues during cancer development. TN is also associated with other diseases, such as developmental disorders, cardiovascular diseases, neurological diseases, inflammation, and diabetes. Although the functional mechanism of TN in diseases is not fully elucidated, TN binds different proteins, such as structural protein, a growth factor, and a transcription regulator. Moreover, TN changes and regulates protein functions, indicating that TN-binding proteins mediate the association between TN and diseases. This review summarizes the current knowledge of TN-associated diseases and TN functions with TN-binding proteins in different diseases. In addition, potential TN-targeted disease treatment by inhibiting the interaction between TN and its binding proteins is discussed.

Identification of novel inhibitors of tetranectin-plasminogen interaction to suppress breast cancer invasion: an integrated computational and cell-based investigation

Tetranectin-plasminogen interaction plays a defining role in extracellular matrix degradation, enabling tumor cell invasion and metastasis. This interaction occurs via the carbohydrate recognition domain (CRD) and Kringle 4 domain of tetranectin and plasminogen, respectively, leading to activation of the plasminogen-cascade that triggers the proteolytic processes. Thus targeting this interaction represents an important strategy to suppress tumor cell migration and invasion. In this direction, we attempted to target the CRD of tetranectin to inhibit its interaction with the Kringle-4 domain of plasminogen using natural bioactive compounds. A cheminformatics pipeline for drug designing and screening was utilized to obtain lead compound(s) that exhibit conformationally and energetically viable CRD binding. Out of 206 compounds screened, diosgenin and scytonemin displayed the most favorable interactions with CRD. Short-term molecular dynamics simulations of 20 ns were employed to further study the conformational stability of both compounds with tetranectin CRD which reflected at the increased stability of diosgenin in the CRD binding pocket compared to scytonemin. Finally, an extended molecular dynamic simulation of 100 ns affirmed the robust and stable interaction of diosgenin with CRD. Furthermore, diosgenin was observed to exert a pronounced anti-proliferative effect on high tetranectin-expressing MDA-MB-231 breast cancer cells. The inhibitory effect of diosgenin on the tetranectin-plasminogen interaction was corroborated by the reduced migration and invasiveness of MDA-MB-231 cells under diosgenin treatment. Overall the study presents an alternate and safer approach to impede breast cancer metastasis and delineates the novel anti-metastatic activity of diosgenin.Communicated by Ramaswamy H. Sarma.

CLEC3B as a Potential Prognostic Biomarker in Hepatocellular Carcinoma

C-Type Lectin Domain Family 3 Member B (CLEC3B) encodes proteins associated with tumor invasion and metastasis. However, the interrelation between CLEC3B gene expression, tumor immunity, and prognosis of patients with hepatocellular carcinoma (HCC) is unclear. This study was conducted to investigate the prognostic potential of CLEC3B and its association with tumor tissue infiltration markers. CLEC3B expression was examined using the TIMER and Oncomine databases, with its prognostic potential assessed using the GEPIA and Kaplan–Meier plotter databases. The relationship between CLEC3B and tumor immune cell infiltration biomarkers was analyzed using TIMER. Here, we revealed that CLEC3B expression was decreased in HCC and was correlated with a poor survival rate in patients with HCC. Additionally, the expression of CLEC3B was negatively correlated with differential immune cell infiltration and various immune biomarkers. These results indicate a potential mechanism by which the expression of CLEC3B might adjust tumor immunity by modulating the infiltration of HCC immune cells. Our study demonstrated that CLEC3B could be a potential prognostic biomarker and might be involved in tumor immune cell infiltration in HCC.

Cancer-associated fibroblasts promote colorectal cancer progression by secreting CLEC3B

Nontumour cells in the tumour microenvironment, especially fibroblasts, contribute to tumour progression and metastasis. The occurrence and evolution of colorectal cancer (CRC) is closely related to cancer-associated fibroblasts (CAFs). The aim of this work was to evaluate the effects of the growth factors and cytokines secreted by CAFs on CRC progression. The secreted cytokines were examined in CAFs by Human Cytokine Antibody array. We screened 37 differentially secreted cytokines in the culture supernatants of CAFs and NFs. CLEC3B, attractin, kallikrein 5 and legumain were selected for further verification. CLEC3B was more highly expressed in the stroma of CRC tissues than the other 3 cytokines. Immunohistochemistry revealed that CLEC3B expression was associated with serosal invasion by CRC. Patients with co-expression of CLEC3B and α-SMA had worse survival outcomes than those with only CLEC3B or α-SMA expression. CLEC3B secreted from CAFs may promote tumour migration. Knockdown of endogenous CLEC3B in CAFs markedly decreased CRC cell migration, while recombinant human CLEC3B clearly promoted CRC cell migration and actin remodelling. In conclusion, our findings suggest that CAFs promote the CRC cell migration and skeletal reorganization by secreting CLEC3B. CLEC3B might be a potential therapeutic molecule for CRC treatment.

High Intratumoral Expression of Tetranectin Associates with Poor Prognosis of Patients with Gastric Cancer after Gastrectomy

Tetranectin, encoded by the clec3b gene, is a plasminogen kringle-4 binding protein that can be detected in the plasma and the extracellular matrix. In malignancies, tetranectin is thought to enhance proteolytic processes enabling tumor cells to invade and metastasize. Nevertheless, the prognostic value of tetranectin in gastric cancer remains elusive. In this study, we found the expression of tetranectin was decreased in gastric cancer. High intratumoral tetranectin level was positively associated with tumor invasion (P = 0.013), lymph node metastasis (P = 0.005), advanced TNM stage (P = 0.003) and shorter overall survival (OS) (P < 0.001) for patients with gastric cancer. Tetranectin expression was identified as an independent prognostic factor for poor OS, and combining tetranectin expression with other independent prognostic factors generated a predictive nomogram, which showed better prognostic efficiency for OS in patients with gastric cancer. In summary, our study suggests that intratumoral tetranectin is a potential independent unfavorable prognostic biomarker for OS of patients with gastric cancer after gastrectomy.

Expression and prognostic significance of Tetranectin in invasive and non-invasive bladder cancer

Tetranectin (TN) is a plasminogen kringle-4 binding protein that can be detected in the plasma and the extracellular matrix. In malignancies, TN is thought to enhance proteolytic processes enabling tumor cells to invade and metastasize. So far, TN expression has not been described in transitional cell bladder cancer (TCC), and there is no information on the prognostic significance of its in situ expression. TN expression was studied in 99 TCC patients diagnosed between 1994 and 1997. Immunohistochemistry was performed on a tissue microarray using a monoclonal antibody against TN (clone 11F1). Within the mean follow-up period of 60 months, pTa and pT2-4 TCC patients with stainable TN in the tumor stroma had a significant shorter recurrence-free survival and higher risk of recurrence compared to those without stainable TN (p = 0.0002 for both). TN expression in the tumor cells did not influence recurrence-free survival. In conclusion, TN is expressed in a subgroup of bladder cancer patients with a higher risk of recurrence who may take benefit from a closer follow-up.

Determination of serum tetranectin: technical and clinical evaluation of three sandwich immunoassays

The performance of two sandwich-type immunoassays for the determination of the tumour marker tetranectin using monoclonal antibodies Hyb 130-13 and 130-14 as catching layer was compared with the performance of a polyclonal assay. Sensitivities were 0.4-0.6 microg/l, and intra- and inter-assay coefficients of variation were < 10% in all assays. One-hundred-and-ten blood donors were examined, and women had higher concentrations of tetranectin in serum than men when measured with monoclonal assays (P < 0.05). In preoperative serum samples from 43 patients with ovarian cancer, tetranectin concentrations were reduced (P < 0.001), and the mean tetranectin concentration decreased with increasing FIGO stage of the patients (P < 0.05). In sera from patients with ovarian cancer, tetranectin concentrations were lower in the polyclonal assay than in the monoclonal assays. This could, hypothetically, be explained by ligand-binding or other conformational changes in tetranectin, influencing the antigenicity of the molecule.

Monoclonal antibodies against human tetranectin, epitope characterization and use in immunohistochemistry

Two IgG2a/kappa- and three IgG1/kappa monoclonal antibodies (MAbs) were produced against human tetranectin (TN): this is the first report of stable hybridomas producing MAbs against TN. All the MAbs reacted with non-conformational epitopes located within amino acid residues 50-181 of the primary sequence. In relative epitope mapping with enzyme immunoassay and isotachophoresis the five MAbs defined two independent epitope groups. One of them is suggested to be immunodominant in rabbits, since MAbs inhibited binding of a polyclonal rabbit antibody. Several combinations of MAbs were suitable for TN-ELISA and two MAbs could be used for immunohistochemical detection of TN in both fresh frozen and paraffin-embedded tissues. The MAbs will facilitate future studies on structure, function, clinical significance and immunolocalization of TN.

The plasminogen activation system in tumour invasion and metastasis

The involvement of proteases in the metastatic spread of tumour cells and in tumour related processes, such as angiogenesis and ulceration, has been known for many decades. This chapter reviews the involvement of one proteolytic system--the plasminogen activation system--in tumour progression. In recent years, many biochemical properties of the various components of the plasminogen activation system have become known. These properties and the functional relationship between the components are discussed in the first section. Since interfering with proteolysis by tumour cells and by newly formed endothelial cells can be an objective for future therapy, experimental tumour models have been used to study the effects of inhibitors of plasminogen activation. The second section deals with this issue. Finally, the presence of the various components of the plasminogen activation system in human tumours is reviewed. Following the availability of specific ELISAs, antibodies and molecular probes, the content and the cellular distribution of the components of the plasminogen activation system have recently been mapped in various human tumours.

Tetranectin and plasmin/plasminogen are similarly distributed at the invasive front of cutaneous melanoma lesions

The induction of expression of the components of the proteolytic plasminogen activation system in cutaneous melanocytic tumour progression has previously been reported. Plasminogen activators, their inhibitors, and the receptor for urokinase were present only in advanced primary melanomas and melanoma metastases. The present study reports on the presence of tetranectin and plasmin/ plasminogen, two proteins connected with plasminogen activation, in cutaneous melanocytic lesions. The distribution of tetranectin and plasminogen was studied by immunohistochemistry in 105 freshly frozen melanocytic lesions of common naevocellular naevi (n = 24), atypical naevi (n = 14), early (n = 12) and advanced (n = 20) primary melanomas, and melanoma metastases (n = 35). Both tetranectin and plasminogen were detected in a variety of tissue components. In all stages of melanocytic tumour progression, tetranectin was found in endothelium, perivascular dendritic cells, and leukocytes. Plasminogen was present in endothelium and in the basal layer of the normal skin. Tetranectin and plasminogen staining of fibroblastic cells at the invasive front and of extracellular matrix was, however, restricted to malignant lesions. Co-localization of tetranectin and plasminogen was found in 50 per cent of the early primary melanomas and in more than 75 per cent of the advanced melanomas and melanoma metastases. These results suggest a coordinated role for tetranectin and plasminogen at the invasive front of melanomas. Tetranectin-bound plasminogen may facilitate the migration of tumour cells.

Prognostic value of plasminogen activators and their inhibitors in colorectal cancer

Colorectal tumorigenesis is associated with remarkable changes in the plasminogen activation system at the tissue level. The sequence of normal mucosa-adenomatous polyp-adenocarcinoma-metastasis is accompanied by an increase in the urokinase-type of plasminogen activator, the urokinase receptor and the inhibitors type-1 and type-2, with a concurrent decrease in the tissue-type plasminogen activator. Overall survival analysis of colorectal cancer patients, with a follow-up of more than 5 years, revealed that several of these components, in both the carcinomas and their corresponding normal mucosa, are of prognostic value independent of major clinicopathological parameters. Therefore, the plasminogen activation cascade not only contributes to the invasive and metastatic growth of colorectal tumours, but might also have a clinical impact with respect to adjuvant and intervention therapy.