Structural Variability, Expression Profile, and Pharmacogenetic Properties of TMPRSS2 Gene as a Potential Target for COVID-19 Therapy

The human serine protease serine 2 TMPRSS2 is involved in the priming of proteins of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and represents a possible target for COVID-19 therapy. The TMPRSS2 gene may be co-expressed with SARS-CoV-2 cell receptor genes angiotensin-converting enzyme 2 (ACE2) and Basigin (BSG), but only TMPRSS2 demonstrates tissue-specific expression in alveolar cells according to single-cell RNA sequencing data. Our analysis of the structural variability of the TMPRSS2 gene based on genome-wide data from 76 human populations demonstrates that a functionally significant missense mutation in exon 6/7 in the TMPRSS2 gene is found in many human populations at relatively high frequencies, with region-specific distribution patterns. The frequency of the missense mutation encoded by rs12329760, which has previously been found to be associated with prostate cancer, ranged between 10% and 63% and was significantly higher in populations of Asian origin compared with European populations. In addition to single-nucleotide polymorphisms, two copy number variants were detected in the TMPRSS2 gene. A number of microRNAs have been predicted to regulate TMPRSS2 and BSG expression levels, but none of them is enriched in lung or respiratory tract cells. Several well-studied drugs can downregulate the expression of TMPRSS2 in human cells, including acetaminophen (paracetamol) and curcumin. Thus, the interactions of TMPRSS2 with SARS-CoV-2, together with its structural variability, gene–gene interactions, expression regulation profiles, and pharmacogenomic properties, characterize this gene as a potential target for COVID-19 therapy.

LncRNA RHPN1-AS1 accelerates proliferation, migration, and invasion via regulating miR-485-5p/BSG axis in hepatocellular carcinoma

It is reported that long noncoding RNA RHPN1-AS1 (lncRNA RHPN1-AS1) functions as an oncogene among multiple types of cancers; however, the effect of lncRNA RHPN1-AS1 in hepatocellular carcinoma (HCC) is left to be investigated. The main purpose of this work was to study the effects of lncRNA RHPN1-AS1/miR-485-5p system on proliferation, migration, and invasion in HCC and future investigate the latent mechanisms. Our work found that lncRNA RHPN1-AS1 was observably up-regulated in HCC tissues and cell lines, especially HCCLM3 and SMMC-7721 cells. LncRNA RHPN1-AS1 knockdown decreased the capacity of proliferation, invasion, and migration in HCCLM3 and SMMC-7721 cells, which could be crippled by miR-485-5p inhibitor. Besides, the expression of basigin (BSG) was decreased after lncRNA RHPN1-AS1 silence, indicating the function of lncRNA RHPN1-AS1/miR-485-5p/BSG axis in HCC progression. Our study opens novel insights to help understand the mechanisms of lncRNA RHPN1-AS1/miR-485-5p/BSG axis in HCC progression, which may provide a new therapeutic target for HCC treatment.

Physcion 8-O-β-glucopyranoside prevents hypoxia-induced epithelial-mesenchymal transition in colorectal cancer HCT116 cells by modulating EMMPRIN

Epithelial-mesenchymal transition (EMT) is considered as the most important mechanism that underlies the initiation of cancer metastasis. Here we report that Physicon 8-O-β-glucopyranoside (PG), a major active ingredient from a traditional Chinese herbal medicine Rumex japonicus Houtt, is capable of preventing human colorectal cancer cells from hypoxia-induced EMT. The treatment of the cells with PG reversed the EMT-related phenotype that has the morphological changes, down-regulation of E-cadherin, and hypoxia-induced cell migration and invasion. The effect was mediated at least in part by inhibiting the mRNA and protein expressions of EMMPRIN via modulation of PTEN/Akt/HIF-1α pathway. In addition, we found that PG-mediated prevention of EMT involved blockade of the hypoxia-induced up-regulation of Snail, Slug and Twist. In summary, this study showed that PG can prevent EMT induced by hypoxia, the environment that commonly exists in the center of a solid tumor. Given the low toxicity of PG to the healthy tissues, our study suggests that PG can serve as a safe therapeutic agent for suppressing cancer metastasis.

Expression of extracellular matrix metalloproteinase inducer and matrix metalloproteinase-2 and -9 in horses with chronic airway inflammation

OBJECTIVE To examine whether expression of extracellular matrix metalloproteinase inducer (EMMPRIN) can be detected in equine lungs and whether it correlates with matrix metalloproteinase (MMP)-2 and -9 expression in bronchoalveolar lavage fluid (BALF) of horses with chronic inflammation of the lungs (ie, lower airway inflammation [LAI]). ANIMALS 29 horses with signs of chronic respiratory tract disease, which were classified as the LAI (n = 17) and LAI with respiratory distress (RDLAI [12]) groups, and 15 control horses. PROCEDURES BALF, tracheal aspirate, and blood samples were obtained, and EMMPRIN expression was determined from BALF cells and RBCs by use of western blotting. Activities of MMP-2 and -9 were determined with zymography. RESULTS Expression of EMMPRIN protein was identified in BALF cells of all horses. Expression of EMMPRIN protein was highest for the RDLAI group and was correlated with MMP-2 and -9 protein expression, MMP-9 gelatinolytic activity, and airway neutrophilia. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that EMMPRIN was involved in the pathophysiologic processes of asthma in horses. However, additional studies of horses and other species are warranted to elucidate the regulation of EMMPRIN expression in asthmatic lungs.

Epidermal CD147 expression plays a key role in IL-22-induced psoriatic dermatitis

Psoriasis is a chronic inflammatory skin disease characterized by abnormal keratinocyte proliferation and terminal differentiation. Interleukin-22 (IL-22) and the transcription factor Stat3 play pivotal roles in the pathogenesis of psoriasis. CD147 is a transmembrane glycosylation protein that belongs to the immunoglobulin superfamily. Our previous studies have shown that CD147 is a marker of high keratinocyte proliferation and poor keratinocyte differentiation as well as a psoriasis susceptibility gene. The current study demonstrates that CD147 is highly expressed in psoriatic skin lesions. Specific CD147 over-expression in the epidermis of K5-promoter transgenic mice promotes imiquimod (IMQ)-induced psoriasis-like inflammation characterized by acanthosis, granular layer loss and inflammatory cell infiltration. We also found that IL-22 increases CD147 transcription in vitro and in vivo and that Stat3 binds directly to the CD147 promoter between positions -854 and -440, suggesting that CD147 expression is up-regulated in patients with psoriasis through Stat3 activation. In addition, CD147 knockdown dramatically blocks IL-22-mediated Stat3 activation as well as IL-22-induced cytokine, chemokine and antimicrobial factor expression. Together, these findings show that CD147 is a novel and key mediator of IL-22-induced psoriatic alterations in the epidermis and might be a therapeutic target in patients with psoriasis.

Interaction of KLF6 and Sp1 regulates basigin-2 expression mediated proliferation, invasion and metastasis in hepatocellular carcinoma

Accumulating evidence suggests that the tumor suppressor gene Krüppel-like factor 6 (KLF6) plays important roles in both development and progression of cancer. However, the role of KLF6 in hepatocellular carcinoma (HCC) remains unclear. Cancer-related molecule basigin-2 plays an important role in HCC progression and metastasis. Sp1, one of Sp/KLFs family members, regulates basigin-2 expression in HCC. The involvement of KLFs in basigin-2 regulation and HCC progression and metastasis has not been investigated. We first measured KLF6 expression levels in 50 pairs of HCC and adjacent normal tissues (ANTs) by immunohistochemistry. Specifically, low KLF6 expression but high Sp1 and basigin-2 expression were found in HCC tissues. By contrast, the ANTs showed high KLF6 expression but low Sp1 and basigin-2 expression. Kaplan-Meier analysis showed that higher expression of KLF6 was associated with better overall survival. The survival rate of KLF6-negative patients was lower than that of KLF6-positive patients (P = 0.015). We also found that KLF6 binds to the basigin-2 and Sp1 promoters and decreases their expression. Thus, we identified a microcircuitry mechanism in which KLF6 can repress basigin-2 expression directly by binding to its promoter or indirectly by inhibiting the expression of the transcription factor Sp1 to block gene expression. Additionally, overexpression of KLF6 suppressed the invasion, metastasis and proliferation of HCC cells in vitro and in vivo by targeting basigin-2. Our study provides new evidence that interaction of KLF6 and Sp1 regulates basigin-2 expression in HCC and that KLF6 represses the invasive and metastatic capacities of HCC through basigin-2.

Association Study between an SNP in CD147 and Its Expression With Acute Coronary Syndrome in a Jiangsu Chinese Population

CD147 is an important molecule in the inflammation and proteolysis process. This molecule crucially contributes to the initial and progression of atherosclerotic lesions. A single nucleotide polymorphism in CD147 gene, the rs8259 T/A in the 3'-untranslated region, is responsible for its expression in various cells. This study assessed whether the genetic variation rs8259 is associated with acute coronary syndrome (ACS) and CD147. A total of 943 ACS subjects and 439 stable angina subjects, and 851 controls were genotyped for rs8259 polymorphism by polymerase chain reaction restriction fragment length polymorphism and DNA-sequencing method. Plasma soluble CD147 (sCD147) level was measured by enzyme-linked immunosorbent assay. CD147 mRNA and protein expression in peripheral blood mononuclear cells were tested by real-time quantitative polymerase chain reaction and western blot, respectively. We found that TT genotype and T-allele frequency of CD147 rs8259 in ACS patients were much lower than the other patient groups. Significant difference was not observed between stable angina and controls. CD147 T allele was negatively related to ACS. ACS patients exhibited the highest CD147 expression in peripheral blood mononuclear cells and plasma sCD147 level. The plasma sCD147 levels in the culprit vessel were higher than those in the radial artery. In ACS patients, AA gene carriers had the highest CD147 levels, whereas TT gene carriers had the lowest CD147 levels. Linear regression analysis showed that genotypes and disease conditions contributed 49% to the change of the plasma CD147 level. These results suggested that the single nucleotide polymorphism of CD147 gene rs8259 T/A was associated with ACS susceptibility. Allele T gene may decrease the relative risk of suffering from ACS through downregulation of CD147 expression.

EMMPRIN in gynecologic cancers: pathologic and therapeutic aspects

The highly glycosylated transmembrane protein extracellular matrix metalloproteinase inducer (EMMPRIN) is associated with several pathological conditions, including various types of cancers. In different gynecological malignancies, such as ovarian, cervical, and endometrial cancers, EMMPRIN plays significant roles in cell adhesion modulation, tumor growth, invasion, angiogenesis, and metastasis by inducing the production of various molecules, including matrix metalloproteinases and vascular endothelial growth factor. Because of its high level of expression, EMMPRIN can possibly be used as a diagnostic marker of gynecological cancers. Recent studies have showed that targeting EMMPRIN, especially by RNA interference (RNAi) technology, has promising therapeutic potential in basic research on gynecological cancer treatments, which make a platform for the future clinical success. This review study focused on the association of EMMPRIN in gynecological cancers in the perspectives of pathogenesis, diagnosis, and therapeutics.

Expression of extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) in pancreatic neoplasm and pancreatic stellate cells

EMMPRIN (extracellular matrix metalloproteinase inducer, CD147) participates in the progression of various malignancies by stimulating the synthesis of specific matrix metalloproteinases (MMP) from peritumoral fibroblasts. In the present study, the expression and functional role of EMMPRIN was investigated in pancreatic neoplasm. QRT-PCR, immunohistochemistry, immunoblot, and ELISA analyses were used to analyze the expression, localization, and release of EMMRPIN. Silencing of EMMPRIN was performed using siRNA oligonucleotides, and functional consequences were assessed using growth assays, invasion assays, as well as MMP1/MMP2 and VEGF ELISA. EMMPRIN mRNA levels were 2.2-fold increased in pancreatic cancer (n = 52) and 2.0-3.5-fold increased in other pancreatic neoplasm (n = 105), but unchanged in chronic pancreatitis (n = 10) compared to normal pancreatic tissues (n = 9). Strong and predominantly membranous immunostaining was observed in the cancer cells and surrounding stromal cells. EMMPRIN serum levels were also significantly increased in pancreatic cancer patients (n = 44) (4.13 +/- 0.28 ng/ml) with an AUC of 0.97 compared to healthy volunteers (n = 29) (0.95 +/- 0.16 ng/ml; p < 0.0001) and with an AUC of 0.74 compared to chronic pancreatitis patients (n = 20) (2.98 +/- 0.5 ng/ml; p = 0.0021). EMMPRIN silencing did not significantly affect anchorage-dependent or -independent growth of pancreatic cancer cells. In contrast, EMMPRIN silencing in pancreatic stellate cells slightly repressed VEGF and MMP2 levels but strongly increased pro-MMP1 expression under coculture conditions. In conclusion, Increased EMMPRIN expression is present in different pancreatic neoplasm, likely representing a tumor-specific reaction with the potential to modulate the tumor microenvironment rather than a mere reflection of an activated stroma.

[CD147 expression level and rs8259 T/A polymorphism of CD147 in patients with acute coronary syndrome]

OBJECTIVE

To investigate the association between CD147 expression and its untranslated regions 3'UTR rs8259 T/A polymorphism and acute coronary syndrome (ACS).

METHODS

The genotypes of CD147 were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods in 182 ACS patients and 328 healthy controls. The plasma level of CD147 was determined by enzyme-linked immunosorbent assay (ELISA). CD147 mRNA and protein expression was detected by real-time fluorescent quantitative PCR (RT-qPCR) and Western blot.

RESULTS

The plasma CD147 level obtained from radial artery in ACS patients ((3.63 ± 0.70) pg/L) was significantly higher than in control ((2.45 ± 0.27) pg/L, P < 0.05), and highest in plasma obtained from the coronary artery ((4.28 ± 1.03) pg/L, P < 0.05) in ACS patients. Furthermore, the plasma CD147 level was higher in the ACS patients with rs8259 AA genotype than in the ACS patients with rs8259 TT genotype ((4.08 ± 0.41) pg/L vs. (3.05 ± 0.79) pg/L in radial artery and (5.29 ± 0.62) pg/L vs. (3.13 ± 0.52) pg/L in coronary artery, both P < 0.05). There are an enhanced expression of CD147 mRNA (2.45 times higher than control) and protein (3.66 ± 1.56 vs. 1.81 ± 1.29) in PBMCs from ACS patients than that from controls (both P < 0.05). The PBMCs CD147 mRNA and protein expression level were significantly higher in ACS patients with rs8259 AA genotype (mRNA:2.45 ± 0.35, protein:1.63 ± 0.16) compared to ACS patients with rs8259 TT genotype (mRNA:1.69 ± 0.15, protein: 0.88 ± 0.16, both P < 0.05). Multiple logistic analysis showed that CD147 T allele (AT+TT) was a protective factor to ACS (OR = 0.667, 95% CI 0.507-0.879, P < 0.05).

CONCLUSIONS

The over-expression of CD147 is involved in the pathogenesis of ACS. The CD147 3'UTR rs8259 T allele may be a protective factor for ACS, its polymorphism can affect the CD147 protein expression in ACS patients.

Prognostic significance of lactate/proton symporters MCT1, MCT4, and their chaperone CD147 expressions in urothelial carcinoma of the bladder

OBJECTIVE

To investigate the prognostic significance of lactate/proton monocarboxylate transporters MCT1, MCT4, and their chaperone CD147 expressions in urothelial carcinoma of the bladder (UCB).

METHODS

We examined the expressions of MCT1, MCT4, and CD147 proteins in a total of 360 cases of UCB by immunohistochemistry. The immunohistochemical expressions were quantified using an ImageJ-based analysis program.

RESULTS

MCT1, MCT4, and CD147 expressions were increased in 130 (36.1%), 168 (46.7%), and 228 (63.3%) UCB cases, respectively. Most tumor cells showed diffuse membranous staining, whereas normal urothelial cells showed negative or weak staining. High levels of MCT1 expression correlated with high World Health Organization grade (P<.001), advanced tumor node metastasis (TNM) stage (P<.001), nonpapillary growth type (P<.001), and lymphatic tumor invasion (P=.010), whereas high levels of MCT4 expression did not significantly correlate with any of these variables. High CD147 expression was associated with high World Health Organization grade (P<.001), advanced tumor node metastatis stage (P<.001), and nonpapillary growth type (P=.003). Univariate analyses revealed that high MCT1 (P<.001) and CD147 (P=.029) expressions were associated with poor overall survival and that high MCT4 expression was correlated with poor recurrence-free survival (P=.036). Multivariate analyses revealed that high MCT1 and MCT4 expressions were independent prognostic factors for poor overall survival and poor recurrence-free survival, respectively, in UCB patients.

CONCLUSION

Our results indicate that increased MCT1, MCT4, and CD147 expressions have prognostic implications in UCB and suggest their roles in urothelial cancer metabolism.

CD147 expression in uterine smooth muscle tumors, and its potential role as a diagnostic and prognostic marker in patients with leiomyosarcoma

OBJECTIVE

To investigate the role of CD147 expression in uterine smooth muscle neoplasms, as a potential diagnostic and prognostic marker in patients with leiomyosarcoma (LMS).

STUDY DESIGN

We investigated CD147 protein expression in uterine smooth muscle tumor samples from patients diagnosed with leiomyoma (n = 22), atypical leiomyoma (BLM) (n = 5), smooth muscle tumor of uncertain malignant potential (STUMP) (n = 14), and LMS (n = 22). The intensity and extensity of immunohistochemical staining were compared to determine its potential role in differential diagnosis. Spearman's rank correlation tests were performed to determine the relationship between CD147 expression and prognostic clinical and pathological criteria in the patients with LMS.

RESULTS

CD147 was strongly expressed in 81.8% (n = 18) of the LMS tissue samples. In fact expression of CD147 in LMS tissues was significantly higher than that of the three other uterine smooth muscle tumor types (p = 0.000). However, high CD147 expression was found in only one BLM sample and one STUMP sample. Furthermore, CD147 percent expression positively correlated with Ki67 percent expression (r = 0.466, p<0.05) and mitotic index (r = 0.554, p<0.05), respectively.

CONCLUSION

Our results suggest that immunohistochemistry may be a helpful tool in determining whether CD147 is a useful marker in the differential diagnosis of certain uterine smooth muscle tumors. CD147 may also have prognostic value for patients with LMS. Yet, in order to determine the extent of this potential marker's utility as a diagnostic and prognostic indicator, a larger randomized multicenter study must be performed.

Oxidized low-density lipoprotein-induced CD147 expression and its inhibition by high-density lipoprotein on platelets in vitro

INTRODUCTION

Matrix metalloproteinases (MMPs) are believed to progressively degrade the collagenous components of the protective fibrous cap, leading to atherosclerotic plaque rupture or destabilization. Oxidized low-density lipoprotein (ox-LDL) enhances the release of CD147, known as the extracellular MMP inducer, from coronary smooth muscle cells. However, whether ox-LDL can induce platelet CD147 expression is unknown. Therefore, we investigated the influence of ox-LDL and high-density lipoprotein (HDL) on CD147 expression on human platelets.

MATERIALS AND METHODS

Washed platelets were incubated with ox-LDL (or native LDL) and HDL or anti-LOX-1 monoclonal antibody prior to incubation with ox-LDL. In parallel, buffer (PBS) was added to washed platelets as a control. The expression levels of CD147, CD62P, CD63 and Annexin V were assessed by flow cytometry, and soluble CD147 from the platelets was assessed by an enzyme-linked immunosorbent assay. Laser scanning microscopy (LSM) and transmission electron microscopy (TEM) were used to visualize the morphological changes and granule release, respectively, from the platelets.

RESULTS

Platelets treated with ox-LDL exhibited a significant increase in the expression of CD147 (or Annexin V), followed by increases in CD62P and CD63, compared with the control group. In contrast, HDL or anti-LOX-1 monoclonal antibody decreased these effects. The expression of soluble CD147 increased as the concentration of ox-LDL used to treat the platelets increased. After exposure to ox-LDL, morphological changes and granule release in the platelets were visualized by LSM and TEM. Additionally, the TEM revealed that HDL inhibits alpha-granule release.

CONCLUSIONS

In platelets, ox-LDL stimulates the release of CD147 via binding to LOX-1, whereas HDL inhibits this effect. This finding could provide new insights concerning the influence of ox-LDL and HDL on plaque stability by the up-regulation of CD147 on platelets.

Reduction of CD147 surface expression on primary T cells leads to enhanced cell proliferation

BACKGROUND

CD147 is a ubiquitously expressed membrane glycoprotein that has numerous functional associations in health and disease. However, the molecular mechanisms by which CD147 participates in these processes are unclear. Establishing physiologically relevant silencing of CD147 in primary T cells could provide clues essential for elucidating some aspects of CD147 biology. To date, achieving the knockdown of CD147 in primary T cells has remained elusive.

OBJECTIVE

Utilizing RNA interference and the Nucleofector transfection system, we were able to reduce the expression of CD147 in primary T cells. Comparison of basic functions, such as proliferation and CD25 expression, were then made between control populations and populations with reduced expression.

RESULTS

Up-regulation of CD147 was found upon T-cell activation, indicating a role in T-cell responses. To better understand the possible importance of this up-regulation, we knocked down the expression of CD147 using RNA interference. When compared to control populations the CD147 knockdown populations exhibited increased proliferation. This alteration of cell proliferation, however, was not linked to a change in CD25 expression.

CONCLUSIONS

We achieved reduction of CD147 surface expression in primary T cells by siRNA-mediated gene silencing. Our results point to CD147 having a possible negative regulatory role in T cell-mediated immune responses.

In vitro and in vivo prostate cancer metastasis and chemoresistance can be modulated by expression of either CD44 or CD147

CD44 and CD147 are associated with cancer metastasis and progression. Our purpose in the study was to investigate the effects of down-regulation of CD44 or CD147 on the metastatic ability of prostate cancer (CaP) cells, their docetaxel (DTX) responsiveness and potential mechanisms involved in vitro and in vivo. CD44 and CD147 were knocked down (KD) in PC-3M-luc CaP cells using short hairpin RNA (shRNA). Expression of CD44, CD147, MRP2 (multi-drug resistance protein-2) and MCT4 (monocarboxylate tranporter-4) was evaluated using immunofluorescence and Western blotting. The DTX dose-response and proliferation was measured by MTT and colony assays, respectively. The invasive potential was assessed using a matrigel chamber assay. Signal transduction proteins in PI3K/Akt and MAPK/Erk pathways were assessed by Western blotting. An in vivo subcutaneous (s.c.) xenograft model was established to assess CaP tumorigenecity, lymph node metastases and DTX response. Our results indicated that KD of CD44 or CD147 decreased MCT4 and MRP2 expression, reduced CaP proliferation and invasive potential and enhanced DTX sensitivity; and KD of CD44 or CD147 down-regulated p-Akt and p-Erk, the main signal modulators associated with cell growth and survival. In vivo, CD44 or CD147-KD PC-3M-luc xenografts displayed suppressed tumor growth with increased DTX responsiveness compared to control xenografts. Both CD44 and CD147 enhance metastatic capacity and chemoresistance of CaP cells, potentially mediated by activation of the PI3K and MAPK pathways. Selective targeting of CD44/CD147 alone or combined with DTX may limit CaP metastasis and increase chemosensitivity, with promise for future CaP treatment.

Expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and its expected roles in the bovine endometrium during gestation

Extracellular matrix metalloproteinase inducer (EMMPRIN) and its induced matrix metalloproteinases (MMPs) play a crucial role in tissue remodeling during the peri-implantation period. However, the role of EMMPRIN in the bovine placenta is still unclear. We have postulated that EMMPRIN might play a regulatory role in trophoblastic cell functions during gestation by itself or through the regulation of MMP expression. In this study, EMMPRIN mRNA was detected in the bovine placentome and interplacentome throughout gestation, and its expression was significantly higher in the cotyledon during late gestation. In situ hybridization showed that EMMPRIN mRNA was expressed in the caruncular epithelium and the cotyledonary epithelium, including binucleate cells. Western blot analysis detected a band representing a protein of approximately 65 kDa in the caruncular and cotyledonary tissues, and the intensity of its expression was increased in both of these tissues during late gestation. The expression levels of MMP-2 and MMP-14 in the bovine placenta were higher during late gestation, as was observed for EMMPRIN. Therefore, EMMPRIN might regulate trophoblastic cell functions, especially those of binucleate cells, through MMP expression in the bovine placenta.

Quantitative proteomic analysis of cyclosporine-induced toxicity in a human kidney cell line and comparison with tacrolimus

The calcineurin-inhibitors (CNIs) cyclosporine (CsA) and tacrolimus (TAC) remain the pillars of modern immunosuppression regimens used in solid organ transplantation. Nephrotoxicity is an adverse effect that limits their successful use. The precise molecular mechanisms underlying this nephrotoxicity remain unclear. Using SILAC together with LC-MALDI-TOF/TOF, we investigated the CNIs-induced proteomic perturbations in renal cells. Among the 495 proteins quantifiable in both forward and reverse SILAC, 69 displayed CsA-induced perturbations: proteins involved in ER-stress/protein folding, apoptosis, metabolism/transport or cytoskeleton pathways were up-regulated, while cyclophilin B as well as nuclear and RNA-processing proteins were down-regulated. Co-administration of CsA with the antioxidant N-acetylcysteine significantly decreased lipid peroxidation and also partially corrected the CsA-induced unfolded protein response. TAC toxicity profile was apparently different from that of CsA, especially without perturbation of cyclophilins A and B, up-regulation of ER-chaperones nor down-regulation of a number of nuclear proteins. These results provide a new insight and are consistent with recent data regarding the molecular mechanisms of CNIs-induced nephrotoxicity. Our findings offer new directions for future research aiming to identify specific biomarkers of CsA nephrotoxicity.

CD147 overexpression is a prognostic factor and a potential therapeutic target in bladder cancer

CD147, also named extracellular matrix metalloproteinase inducer (EMMPRIN), has been shown to be involved in the progression of malignancy by regulating expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). The goal of this study was to evaluate the role of CD147 in the biology of bladder cancer and to determine its potential as a therapeutic target. CD147 protein expression was detected by immunohistochemistry in 108 bladder cancers using a tissue microarray annotated with patient follow-up. In immunohistochemistry, CD147 protein expression was associated with poor prognosis (P<0.001), lymph node status (P<0.001), tumor stage (P=0.003), histologic grade (P=0.011). Multivariate analysis showed that CD147 overexpression was an independent prognostic factor (P=0.019). Infection of T24 bladder cancer cells with an adenovirus that expressed a small interfering RNA (siRNA) against CD147 efficiently inhibited CD147 protein and mRNA expression. This resulted in decreased proliferation, soft agar colony formation, migration, and invasion of T24 cells in vitro. Moreover, downregulation of CD147 reduced secretion of MMP-2 and MMP-9 and expression of VEGF in these cells. Our findings suggest that CD147 overexpression plays an important role in progression of bladder cancer, and CD147 could be a potential target of bladder cancer therapy.

Expression of extracellular matrix metalloproteinase inducer (EMMPRIN) in healthy and inflamed human gingival

OBJECTIVE

To evaluate the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) in healthy and inflamed human gingiva.

METHOD AND MATERIALS

Tissue samples from 9 healthy specimens and 21 specimens with chronic periodontitis were collected. The expression of EMMPRIN protein was detected with immunohistochemical staining and Western blot analysis.

RESULTS

EMMPRIN was mainly localized in keratinocytes of healthy human gingival tissues; in inflamed gingival tissues, EMMPRIN protein could be detected in keratinocytes, fibroblasts, and inflammatory cells. In addition, EMMPRIN expression level in the inflamed gingiva was increased dramatically compared to that in healthy tissue (P < .05). Using Western blot analysis, EMMPRIN protein was also found to express in both healthy and inflamed gingiva, and the level of EMMPRIN in inflamed gingiva was significantly higher than that in healthy control subjects (P < .05).

CONCLUSION

EMMPRIN might be involved in the physiologic and pathologic states of periodontal tissues.

[Matrix metalloproteinase 2 and 9 as the factor of head and neck tumor metastasis]

The levels of metalloproteinases (MMP-2,-9), their tissue inhibitors (TIMP-1,-2) and extracellular matrix metalloproteinase inducer (EMMPRIN) were studied in tumor tissue and blood serum from patients with head and neck squamous sell carcinoma. Immunohistochemical investigation showed much higher expression of MMP-9 and TIMP-1 in tumor tissue than MMP-2 and TIMP-2. Different expression of the studied parameters (except TIMP-1) in cancer cells and stroma was observed. Enhanced level of MMP-2,-9 and TIMP-2 expression was revealed mainly in fibrocytes, leukocytes and stromal extracellular matrix. Expression of EMMPRIN in tumor cells was higher than in stromal cells. It is possible that carcinoma cells express EMMPRIN to increase MMP production by surrounding cells. Significant decrease of inhibitor expression was observed in cells of carcinomas with N1 grade of metastasis than in tumors without metastasis. Also the decrease in TIMP-1 level was determined in blood serum of patients with metastasis to regional lymph nodes compared with serum of patients without metastasis. Thus, MMP-9 and TIMP-1 play an important role in the development of head and neck squamous sell carcinoma and TIMP-1 level in blood serum and cancer tissues is linked to first grade of regional lymph node metastasis.

The role of extracellular matrix metalloproteinase inducer protein in prostate cancer progression

Extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) is a multifunctional membrane glycoprotein overexpressed in many solid tumors, and involved in tumor invasion and angiogenesis. We investigated EMMPRIN expression in human prostate cancer (CaP) tissues and cells, and evaluated whether EMMPRIN expression is related to tumor progression and matrix metalloproteinase (MMPs) expression in human CaP. An immunohistochemical study using tissue microarrays of 120 primary CaPs of different grades and 20 matched lymph node metastases from untreated patients was performed. The association of EMMPRIN expression with clinicopathological parameters was evaluated. Co-immunolocalization for EMMPRIN and MMP-1, MMP-2 or MMP-9 in primary tumors was examined using confocal microscopy. Flow cytometry and immunoblotting were used to examine EMMPRIN expression in 11 metastatic CaP cell lines. Heterogeneous expression of EMMPRIN was found in 78/120 (65%) CaPs, correlated significantly with progression parameters including pre-treatment PSA level (P < 0.05) and increased with progression of CaP (Gleason score, P < 0.05; pathological stage, P < 0.01; nodal involvement, P < 0.05 and surgical margin, P < 0.05). Heterogeneous cytoplasmic MMP-1, MMP-2 and MMP-9 associated with EMMPRIN immunolabeling was observed, particularly in tumors with Gleason scores >3 + 4. Metastatic CaP cell lines, except DuCaP, expressed abundant EMMPRIN protein, indicating highly ( approximately 45 to approximately 65 kDa) and less ( approximately 30 kDa) glycosylated forms, although with no relationship to cells being either androgen responsive or nonresponsive. Our results suggest that EMMPRIN may regulate MMPs and be involved in CaP progression, and as such, could provide a target for treating metastatic CaP disease.

EMMPRIN modulates migration and deposition of TN-C in oral squamous carcinoma

The extracellular matrix metalloproteinase inducer (EMMPRIN), found on the surface of many tumor cells, stimulates the production of matrix metalloproteinases (MMPs) by both fibroblasts and the tumor cells themselves. To evaluate its possible role as a tumor promoter, we first overexpressed EMMPRIN, by retroviral transduction, into poorly invasive squamous cell carcinoma (SCC) cells. Secondly, we knocked down its expression using small interfering RNA (siRNA) in invasive SCC cells. The cell lines were then re-evaluated for migration on fibronectin (FN). Overexpression of EMMPRIN, promoted motility, whereas the siRNA decreased migration. The MMP expression by these variant SCC cell lines was also manipulated by EMMPRIN. The expression of MMP-2, -3, and -9 coincided with the expression of EMMPRIN. Cocultures of SCC/peritumor fibroblasts (PTF) were used to investigate tenascin-C (TN-C) matrix deposition. The cocultures overexpressing EMMPRIN, deposited several fold greater levels of TN-C compared to the control cocultures. In addition, the siRNA cocultures deposited minimal amounts of TN-C. In the presence of the broad spectrum MMP inhibitor, GM6001, TN-C deposition by the EMMPRIN overexpressing cocultures was suppressed. Thus EMMPRIN regulates migration, MMP production by SCC cells and deposition of the TN-C matrix.

Kinetic analysis of butyrate transport in human colon adenocarcinoma cells reveals two different carrier-mediated mechanisms

Butyrate has antitumorigenic effects on colon cancer cells, inhibits cell growth and promotes differentiation and apoptosis. These effects depend on its intracellular concentration, which is regulated by its transport. We have analysed butyrate uptake kinetics in human colon adenocarcinoma cells sensitive to the apoptotic effects of butyrate (BCS-TC2, Caco-2 and HT-29), in butyrate-resistant cells (BCS-TC2.BR2) and in normal colonic cells (FHC). The properties of transport were analysed with structural analogues, specific inhibitors and different bicarbonate and sodium concentrations. Two carrier-mediated mechanisms were detected: a low-affinity/high-capacity (K(m)=109+/-16 mM in BCS-TC2 cells) anion exchanger and a high-affinity/low-capacity (K(m)=17.9+/-4.0 microM in BCS-TC2 cells) proton-monocarboxylate co-transporter that was energy-dependent and activated via PKCdelta (protein kinase Cdelta). All adenocarcinoma cells analysed express MCT (monocarboxylate transporter) 1, MCT4, ancillary protein CD147 and AE2 (anion exchanger 2). Silencing experiments show that MCT1, whose expression increases with butyrate treatment in butyrate-sensitive cells, plays a key role in high-affinity transport. Low-affinity uptake was mediated by a butyrate/bicarbonate antiporter along with a possible contribution of AE2 and MCT4. Butyrate treatment increased uptake in a time- and dose-dependent manner in butyrate-sensitive but not in butyrate-resistant cells. The two butyrate-uptake activities in human colon adenocarcinoma cells enable butyrate transport at different physiological conditions to maintain cell functionality. The high-affinity/low-capacity transport functions under low butyrate concentrations and may be relevant for the survival of carcinoma cells in tumour regions with low glucose and butyrate availability as well as for the normal physiology of colonocytes.

[Increased expression of extracellular matrix metalloproteinase inducer through interaction between fibroblasts and colonic cancer cells]

OBJECTIVE

To investigate the expression of extracellular matrix metalloproteinase inducer gene (EMMPRIN) regulated by the interactions between fibroblasts and colon cancer cells, and to study its role in the invasion and metastasis of colon cancer.

METHODS

Colon cancer cells (SW480) were co-cultured with fibroblasts (HELF) in RPMI 1640 media for 0, 12, 24 and 48 hours. The expression of EMMPRIN in SW480 cells and HELF cells was documented by RT-PCR and immunocytochemistry.

RESULTS

The mRNA and protein expressions of EMMPRIN in SW480 cells were remarkably increased by the co-culturing with HELF cells. Although without the endogenous expression, HELF cells began to express EMMPRIN in a time-dependent manner after being co-cultured with SW480 cells.

CONCLUSIONS

Intercellular interactions between colon cancer cells and fibroblasts not only up-regulate the EMMPRIN expression in SW480 cells, but also induce its expression in HELF cells. Such interactions may play a crucial role in the invasion and metastasis of colon cancer.

Characterization of 3 oral squamous cell carcinoma cell lines with different invasion and/or metastatic potentials

PURPOSE

Proteolytic enzymes may confer specific types of invasion and metastasis in patients with oral squamous cell carcinoma (OSCC). The purpose of this study was to determine if OSCC that invades adjacent bone has different proteolytic enzyme expression profiles than OSCC that metastasizes to lymph nodes or distant organs. Three OSCC cell lines, BHY, HSC-3, and HN, with known behavior regarding bone invasion and lymph node and distant metastatic profiles, were evaluated. The characteristics of a control, human normal nasal epithelial cell line (HNEC), and BHY, HSC-3 and HN were evaluated with regard to their expression of the matrix metalloproteinases and cathepsins.

MATERIALS AND METHODS

Expressions of proteolytic enzymes including matrix metalloproteinase, MMP-1, MMP-2, MMP-3, MMP-9, extracellular matrix metalloproteinase inducer (EMMPRIN), cathepsin B, and cathepsin L were compared using immunocytochemistry and flow cytometry in 3 OSCC cell lines and HNEC. The cell morphologies of these 4 cell lines were compared using transmission electron microscopy (TEM).

RESULTS

All OSCC cell lines showed higher expression of all the proteolytic proteins when compared with HNEC, except the HSC-3 cell line showed no difference in the expression of MMP-9. There was no detectable difference at the expression level of MMP-1, MMP-2, MMP-3, cathepsin B, and cathepsin L in any of the OSCC cell lines. However, MMP-9 and EMMPRIN levels were higher in the BHY cell line. According to electron microscopy, the cells of the HSC-3 cell line were the smallest and least differentiated among the 3 OSCC cell lines. The BHY cell line was the most highly differentiated showing interdigitation and numerous cell junctions.

CONCLUSIONS

MMPs play an important role in the invasion and metastasis of oral cancer. MMP-9 might play a more important role than MMP-2 during invasion. Increased expression of MMP-1, MMP-9, and EMMPRIN proteins might be involved in invasion of OSCC to adjacent bone, as they are necessary for the collagen matrix degradation. Increased expression of MMP-3, cathepsin B and L in OSCC might be associated with both invasion and a high incidence of metastasis.

Matrix metalloproteinase induction in the tumor stroma does not depend on CD147 expression in murine B16 melanoma

BACKGROUND

It was conclusively demonstrated that the cell surface glycoprotein CD147 on tumor cells mediates induction of matrix metalloproteinases (MMPs) by stromal cells in humans. However, for murine models such evidence remains elusive.

METHODS AND RESULTS

To address the impact of CD147 on MMP expression in the murine B16 melanoma model, we consequently stably knocked down CD147 expression in two B16 sublines. The CD147 knockdown remained stable under in vivo conditions as confirmed by immunohistochemistry. However, no differences in MMP-2, MMP-9 and MT1-MMP expression by stromal and tumor cells were detectable in CD147+ and CD147- tumors. Since the tumor microenvironment is a complex system, involving several cell types, the extracellular matrix and plethora soluble factors, we subsequently studied the role of murine CD147 in vitro. Coculture of melanoma cells with different fibroblast cell lines demonstrated that neither CD147+ nor CD147- B16 tumor cells altered the expression of MMP-2 or MMP-9 by the fibroblasts, although we could confirm the susceptibility of these fibroblasts for MMP induction.

CONCLUSIONS

At least for the murine B16 melanoma model, CD147 expression on tumor cells seems not to be crucial for MMP-2, MMP-9 and MT1-MMP induction on tumor-associated stromal cells.

Immunocytochemical and biochemical detection of EMMPRIN in the rat tooth germ: differentiation-dependent co-expression with MMPs and co-localization with caveolin-1 in membrane rafts of dental epithelial cells

In tooth development matrix metalloproteinases (MMPs) are under the control of several regulatory mechanisms including the upregulation of expression by inducers and downregulation by inhibitors. The aim of the present study was to monitor the occurrence and distribution pattern of the extracellular matrix metalloproteinase inducer (EMMPRIN), the metalloproteinases MMP-2 and MT1-MMP and caveolin-1 during the cap and bell stage of rat molar tooth germs by means of immunocytochemistry. Strong EMMPRIN immunoreactivity was detected on the cell membranes of ameloblasts and cells of the stratum intermedium in the bell stage of the enamel organ. Differentiating odontoblasts exhibited intense EMMPRIN immunoreactivity, especially at their distal ends. Caveolin-1 immunoreactivity was evident in cells of the internal enamel epithelium and in ameloblasts. Double immunofluorescence studies revealed a focal co-localization between caveolin-1 and EMMPRIN in ameloblastic cells. Finally, western blotting experiments demonstrated the expression of EMMPRIN and caveolin-1 in dental epithelial cells (HAT-7 cells). A substantial part of EMMPRIN was detected in the detergent-insoluble caveolin-1-containing low-density raft membrane fraction of HAT-7 cells suggesting a partial localization within lipid rafts. The differentiation-dependent co-expression of MMPs with EMMPRIN in the enamel organ and in odontoblasts indicates that EMMPRIN takes part in the induction of proteolytic enzymes in the rat tooth germ. The localization of EMMPRIN in membrane rafts provides a basis for further investigations on the role of caveolin-1 in EMMPRIN-mediated signal transduction cascades in ameloblasts.

Expression of CD147 and monocarboxylate transporters MCT1, MCT2 and MCT4 in porcine small intestine and colon

Lactate, formed mainly in the stomach and small intestines, and short-chain fatty acids (SCFAs) formed in the colon, are ionised and require transporter proteins such as monocarboxylate transporters (MCTs) for absorption. The amounts of MCT1, MCT2, MCT4 and CD147, an ancillary protein for MCT1 and MCT4, were measured by immunoblotting the small intestine and colon of 40 pigs (Landrace, Yorkshire and LandracexYorkshire). MCT1 and MCT4 were found in both small intestine and colon, but MCT2 only in the small intestine. In both small intestine and colon, Yorkshire pigs had more CD147 than Landrace pigs, while no interbreed differences were found in MCT isoforms. Since CD147 is essential for the activity of MCT1 and MCT4, the breed difference suggests that MCT activity is higher in Yorkshire than in Landrace pigs. The absence of MCT2 in the colon suggests that it is mainly a lactate transporter, while MCT1 and MCT4 facilitate the transport of both lactate and SCFA.

[Expression of matrix metalloproteinase (MMP-2) and extracellular matrix metalloproteinases inducer (EMMPRIN) in benign and advanced breast cancer tissue samples]

Tumor cell derived matrix metalloproteinases are a family of enzymes associated with the tumor invasion and metastasis. Extracellular matrix metalloproteinases inducer (EMMPRIN) stimulates synthesis of gelatinase A (MMP-2) in peritoneal fibroblasts. In the present study the role of MMP-2 and EMMPRIN in the progression of breast cancer has been investigated. Gelatinase-A and EMMPRIN were analyzed in benign and stage II and stage III breast cancer tissue samples by gelatin zymography assay, immunoprecipation analysis and Western blot analysis with a monoclonal primary antibody specific for EMMPRIN. Our results showed overexpression of EMMPRIN in advanced stages of breast cancer tissues compared with benign tumor tissue samples. The expression of MMP-2, the active and latent forms of the enzyme increased with tumor progression from Stage II to Stage III of breast cancer and it was not expressed in benign tissues. The expression MMP-2 correlates with tumor progression. This observation obviously indicates that EMMPRIN and MMP-2 are the major determinants of malignancy in cancers.

Monocarboxylate transporter 4 regulates maturation and trafficking of CD147 to the plasma membrane in the metastatic breast cancer cell line MDA-MB-231

Metastatic cancer cells increase glucose consumption and metabolism via glycolysis, producing large quantities of lactate. Recent work has shown that lactate efflux is mediated by monocarboxylate transporters (MCT), which are composed of a catalytic unit (MCT) and an accessory subunit (CD147), comprising the functional lactate transporter. CD147, an extracellular matrix metalloproteinase (MMP) inducer, is highly expressed in metastatic cancer cells. Because aerobic glycolysis is a hallmark of metastatic cancer, we examined whether increases in CD147 expression were linked to MCT expression in MDA-MB-231, a highly metastatic breast cancer cell line. MCT4 mRNA and protein expression were increased in MDA-MB-231 cells compared with cells derived from normal mammary tissue. MCT4 colocalized with CD147 in the plasma membrane and in membrane blebs shed from the cell surface. Small interfering RNA-mediated silencing of MCT4 impaired the maturation and trafficking of CD147 to the cell surface, resulting in accumulation of CD147 in the endoplasmic reticulum. Silencing MCT4 also resulted in fewer membrane blebs and decreased migration of MDA-MB-231 cells in vitro. Knockdown of CD147 resulted in loss of MCT4 in the plasma membrane and accumulation of the transporter in endolysosomes. These studies establish for the first time that increased expression of CD147 in metastatic cancer cells is coupled to the up-regulation of MCT4. The synergistic activities of the MCT/CD147 complex could facilitate migration of tumor cells by CD147-mediated MMP induction and lactate-stimulated angiogenesis and hyaluronan production. These data provide a molecular link between two hallmarks of metastatic cancer: the glycolytic switch and increased expression of CD147.

Tumor vesicle-associated CD147 modulates the angiogenic capability of endothelial cells

Matrix metalloproteinase (MMP) degradation of extracellular matrix is thought to play an important role in invasion, angiogenesis, tumor growth, and metastasis. Several studies have demonstrated that CD147/extracellular MMP inducer, a membrane-spanning molecule highly expressed in tumor cells, may be involved in the progression of malignancies by regulating expression of MMP in peritumoral stromal cells. In the present study we show that CD147 is expressed in microvesicles derived from epithelial ovarian cancer cells and that CD147-positive vesicles may promote an angiogenic phenotype in endothelial cells in vitro. Vesicles shed by human ovarian carcinoma cell lines OVCAR3, SKOV3, and A2780 expressed different levels of CD147 and stimulated proangiogenic activities of human umbilical vein endothelial cells (HUVECs) in a CD147-dependent fashion (OVCAR3 > SKOV3 > A2780). Moreover, vesicles shed by ovarian carcinoma cell line CABA I with low CD147 expression had no significant effect on the development of angiogenic phenotype in HUVECs. The treatment of OVCAR3 cells with small interfering RNA against CD147 suppressed the angiogenic potential of OVCAR3-derived microvesicles. However, transfection of CD147 cDNA into the CABA I cell line enabled CABA I-derived vesicles to induce angiogenesis and to promote MMP genes expression in HUVECs. We therefore conclude that vesicles shed by ovarian cancer cells may induce proangiogenic activities of HUVECs by a CD147-mediated mechanism.

The sterol carrier protein SCP-x/pro-SCP-2 gene has transcriptional activity and regulates the Alzheimer disease gamma-secretase

The sterol carrier protein SCP-x/pro-SCP-2 gene is a fusion gene having two initiation sites that generate a long (SCP-x; 58.9-kDa) and a short (pro-SCP-2; 15.4-kDa) product, both containing the common SCP-2 module at the C terminus. Here, we show that SCP-x is processed on the peroxisomal surface to liberate a short C-terminal product of 12.9 kDa. This fragment has DNA binding activity in vivo and in vitro, as assessed by chromatin immunoprecipitation analysis, DNA-protein pull-down, electrophoretic mobility shift assay, and luciferase reporter activity. In addition, it is preferentially found in the nucleus where it regulates the transcription of CD147, the regulatory subunit of the Alzheimer disease gamma-secretase. Overexpression of SCP-x increased, whereas antisense oligonucleotides against scp-x decreased, the generation of the above transcription factor. Both biochemical and genetic approaches indicate that pro-SCP-2 acts as a competitive inhibitor of SCP-x processing, thereby controlling the release of the 12.9-kDa transcriptionally active fragment. The transcription regulatory function of pro-SCP-2 requires a peroxisomal targeting sequence at the C terminus and a 20-amino acid leading sequence at the N terminus. Finally, pro-SCP-2 has also cholesterol carrier activity, which is functionally separated from the transcription regulatory one. In conclusion, we have identified two novel functions (transcriptional and transcription regulatory) of the SCP-x/pro-SCP-2 gene that have impact on gamma-secretase activity.

[CD147 and matrix metallo-proteinase (MMP) 2 and MMP9 expression in multidrug resistant breast cancer cells treated with P-glycoprotein substrate drugs]

OBJECTIVE

To investigate effects of P-glycoprotein (gp) substrate drugs on the expression of CD147 and MMP2 and 9 in multidrug resistant breast cancer cells.

METHODS

MDR human breast cancer cell line, MCF7/AdrR, and its sensitive parental line, MCF7, were treated with various concentrations of P-gp substrate drugs, including paclitoxel and vincristine, and P-gp nonsubstrate drugs, bleomycin, in serum-free media. At the end of the treatment, expressions of CD147 and MMP2 and 9 were determined by real-time PCR and western blot.

RESULTS

Increased expressions of CD147 and MMP2 and 9 were observed in multidrug resistant cancer cells compared with their parental MCF7 cells. After treatment with bleomycin, the expression of CD147 and MMP2 and 9 in both MCF7 and MCF7/AdrR cells remained unchanged (P > 0.05). However, treatment with paclitoxel and vincristine resulted in a remarkable over-expression of CD147 and MMP2 and 9 at both transcription and protein levels in MCF7/AdrR cell line (P < 0.05), while MCF7 cells failed to show similar response.

CONCLUSIONS

P-gp substrate drugs can greatly upregulate the expression of CD147 and MMP2 and 9 in multidrug resistant breast cancer cells, therefore enhancing the tumor metastatic capability.

Resveratrol inhibits macrophage expression of EMMPRIN by activating PPARγ

The effect of resveratrol on macrophage EMMPRIN expression and its potential mechanism was investigated. Both EMMPRIN expression and MMP-9 activity, respectively assayed by Western blot and zymography, were greatly up-regulated during PMA-induced macrophage differentiation from THP-1 monocytes. Both resveratrol and a PPARgamma agonist, pioglitazone, significantly inhibited EMMPRIN expression and MMP-9 activity in a concentration-dependent manner. The effects of pioglitazone and resveratrol were reversed by pretreatment of THP-1 cells with a PPARgamma antagonist, GW9662, prior to PMA induction. Thus, data suggest that resveratrol may down-regulate EMMPRIN and MMP-9 through PPARgamma activation. This possibility was further examined in resveratrol-or pioglitazone-treated U937 cells, which had been co-transfected with a PPARgamma expression vector and a luciferase reporter vector containing three tandem repeats of PPRE in cis. Results of the agonist-activated luciferase assay showed that resveratrol activated PPARgamma in a concentration-dependent manner. Since EMMPRIN and MMP-9 up-regulation is associated with activation of the NF-kappaB pathway, we investigated the effect of pioglitazone and resveratrol on TNF-alpha-induced NF-kappaB activation. Western blot results indicated that both pioglitazone and resveratrol markedly inhibited the NF-kappaB pathway through suppressing IkappaB protein phosphorylation in macrophages, although this effect of resveratrol was not reversed by GW9662. In conclusion, resveratrol can down-regulate EMMPRIN expression by macrophages via activating PPARgamma. This may be a primary mechanism of its inhibitory effect on MMP-9.

Increasing EMMPRIN and matriptase expression in hepatocellular carcinoma: tissue microarray analysis of immunohistochemical scores with clinicopathological parameters

AIMS

To examine the expression of extracellular matrix metalloprotease inducer (EMMPRIN) and matriptase in hepatocellular carcinoma (HCC) and to correlate this with tumour progression.

METHODS AND RESULTS

Immunohistochemical analysis of EMMPRIN and matriptase was performed on tissue microarrays of 122 cases of HCC with various histological grades and/or clinical parameters. The expression of EMMPRIN and matriptase was undetectable in normal liver parenchyma of all eight control cases. However, among the 122 HCC cases, EMMPRIN and matriptase immunoreactivity was seen on the cell membrane and in the cytoplasm. The average immunostaining scores of EMMPRIN were 88 for grade I HCC, 195 for grade II HCC and 293 for grade III HCC. Of 85 HCC cases in 122 with detailed clinical TNM stages, the average immunostaining scores of EMMPRIN were 75 for stage T1, 177 for stage T2, 260 for stage T3 and 313 for stage T4 cases of HCC. In addition, the average immunostaining scores of matriptase were 84 for grade I HCC, 187 for grade II HCC, 302 for grade III HCC, and 72 for stage T1, 181 for stage T2, 224 for stage T3 and 284 for stage T4 cases of HCC. More advanced M and N stages of HCC were associated with higher intensity, greater percentages of tumour staining and immunostaining scores of EMMPRIN and matriptase. Higher EMMPRIN and matriptase immunostaining scores in HCCs also correlated significantly with tumour grading and TNM stages.

CONCLUSIONS

Our findings demonstrate for the first time that EMMPRIN and matriptase are overexpressed in HCC. These may be novel biomarkers for the diagnosis and treatment of HCC.

Extracellular matrix metalloprotease inducer stimulates fibroblast-mediated tumor growth in vivo

HYPOTHESIS

Extracellular matrix metalloprotease inducer (EMMPRIN) is a molecule expressed on the cell surface of tumor cells that has been shown to induce both tumor cells and fibroblasts to express matrix metalloproteases in vitro. We hypothesize that fibroblasts are stimulated by EMMPRIN to create a microenvironment favorable to tumor growth.

STUDY DESIGN

Case series review of laryngeal cancer and assessment of tumor cell lines in vivo.

METHODS

EMMPRIN immunoreactivity in 33 pathologic specimens from patients with supraglottic laryngeal cancer was correlated with clinicopathologic features and survival. The CAL 27 cell line was transfected with EMMPRIN (CAL 27E) or a control vector (CAL 27). Cells were xenografted into the flank of severe combined immunodeficient (SCID) mice with or without a co-injection of normal dermal fibroblasts (NDFs).

RESULTS

Immunohistochemical detection of EMMPRIN in laryngeal cancer specimens demonstrated expression in all the tumors but not in adjacent, histologically normal mucosa. EMMPRIN membrane immunoreactivity (transmembrane EMMPRIN score) was associated with nodal positivity (P=.07), and it was associated with poorer survival (hazard ratio=2.4, 95% confidence interval 0.88, 6.55). As a categoric variable, higher EMMPRIN expression positively correlates with higher mortality. To determine whether EMMPRIN mediates tumor growth in vivo through fibroblast stimulation, EMMPRIN-expressing CAL 27 (CAL 27E) xenografted (n=20) onto the flank of SCID mice developed larger tumors than CAL 27 control vector transfected cells alone (n=20), but they were not significantly larger (P=.17). However, when CAL 27E cells were co-injected with NDFs, there was a statistically significant increase in tumor growth compared with the CAL 27 cells co-injected with NDFs (n=10, P=.0038).

CONCLUSIONS

As a cell surface expressed protein that promotes tumor growth and high expression in head and neck squamous cell carcinoma but not in normal tissue, EMMPRIN may be a good target for directed molecular therapy.

Inhibitory effect of PPAR on the expression of EMMPRIN in macrophages and foam cells

OBJECTIVE

Extracellular matrix metalloproteinase inducer (EMMPRIN) is a surface glycoprotein that can stimulate the production of several matrix metalloproteinases (MMPs), which are thought to play an important role in atherosclerotic plaque destabilization and rupture. In order to demonstrate the involvement of EMMPRIN in the process of atherosclerosis, we characterized its expression profile in macrophages and foam cells, as well as its potential modulation by peroxisome proliferator-activated receptors (PPARs) agonists.

METHODS AND RESULTS

Through TaqMan real-time RT-PCR and Western blotting, we found the expression of both EMMPRIN mRNA and protein was significantly increased during phorbol 12-myristate 13-acetate (PMA)-induced monocyte differentiation into macrophages. However, the same results were not observed when macrophages were further induced to become foam cells by oxidized low-density lipoproteins (oxLDL). Both known PPARalpha agonist clofibrate and gamma agonist pioglitazone potently and specifically inhibited EMMPRIN expression in macrophages and foam cells. Moreover, this inhibition was associated with a decrease of MMP-9 secretion and activity as determined by ELISA and zymography. In addition, PPARgamma antagonist GW9662 reversed the inhibitory effect of PPARgamma on EMMPRIN protein expression.

CONCLUSION

Our findings revealed an upregulation of EMMPRIN during monocyte differentiation into macrophages and foam cells. Both PPARalpha and gamma agonists inhibited EMMPRIN expression, which may contribute to their inhibition of MMP.

[Differential expression of extracellular matrix metalloproteinase inducer in normal placenta and preeclampsia placenta]

OBJECTIVE

To study the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) in preeclampsia placenta and the relation with preeclampsia attacks.

METHODS

Forty-four samples from pregnant women with preeclampsia (preeclampsia group), 38 samples from pregnant women with eclampsia, and 49 samples from normal pregnancies (control group) were obtained. We detected the expression of EMMPRIN in placenta by immunohistochemistry and the expression of EMMPRIN mRNA by RT-PCR.

RESULTS

(1) EMMPRIN positive expression: in preeclampsia group, the moderate expression rate was 18% (8/44) and the strong positive rate was 9% (4/44); in eclampsia group moderate positive rate was 21% (8/38) and strong positive rate 13% (5/38). The difference of the two groups was insignificant (P > 0.05). In control group the moderate positive rate was 12% (6/49) and strong positive rate 82% (40/49), the difference from the preeclampsia and the eclampsia groups was significant (P < 0.001). (2) EMMPRIN mRNA expression: in preeclampsia group EMMPRIN mRNA expression in term placenta (37 - 40 gestational weeks) was 0.342 +/- 0.002, and in eclampsia group 0.344 +/- 0.023; the difference between the two groups was insignificant (P > 0.05). In control group EMMPRIN mRNA expression in term placenta (37 - 40 gestational weeks) was 0.872 +/- 0.094, the differences between the control group and preeclampsia and eclampsia groups were both significant (P < 0.001).

CONCLUSION

The decrease in the expression of EMMPRIN in placenta is an important cause of preeclampsia onset; expression rate of EMMPRIN may serve as an indicator in predicting preeclampsia.

[Resveratrol inhibits expression of EMMPRIN from macrophages]

AIM

To investigate the effect of resveratrol on EMMPRIN expression of macrophages.

METHODS

Human monocytic cell line THP-1 cells were co-cultured with EMMPRIN-highly-expressed MCF-7 cells; MMP-9 production was assayed by zymography. THP-1 cells were induced by PMA, expression of EMMPRIN was assayed by Western blotting. Cells were treated with resveratrol or PPARgamma agonist--pioglitazone during differentiation, EMMPRIN expression and MMP-9 activity were assayed. U937 cells were co-transfected with PPARy expression and luciferase-coding reporter vector, then cultured with pioglitazone or resveratrol, the activating capability of resveratrol on PPARgamma was evaluated by measuring the luciferase activity. THP-1 cells were pretreated with PPARgamma antagonist--GW9662 before pioglitazone or resveratrol treatment, then assayed for EMMPRIN expression and MMP-9 production.

RESULTS

EMMPRIN expression was greatly increased during the differentiation from monocytes to macrophages; co-culturing with MCF-7 cells significantly increased MMP-9 production by monocytes. Both resveratrol and pioglitazone markedly inhibited EMMPRIN expression during monocytes differentiation. Resveratrol significantly activated PPARgamma and GW9662 greatly decreased the effect of resveratrol on EMMPRIN and MMP-9.

CONCLUSION

EMMPRIN expression is greatly up-regulated from monocytes to macrophages, which may play a role in inducing MMPs production by monocytes/macrophages. Resveratrol can significantly inhibit EMMPRIN expression via activating PPARgamma, which may be the underlying mechanism of its inhibitory effect on MMPs production by monocytes/macrophages.

Regulation of Matrix Metalloproteinase Production and Tumor Cell Invasion by Four Monoclonal Antibodies Against Different Epitopes of HAb18G/CD147 Extracellular Domain

HAb18G/CD147, a membrane spanning molecule and highly expressed in hepatocellular carcinoma (HCC) cells, was shown to stimulate the production of matrix metalloproteinases (MMPs) in the interaction of tumor cells and fibroblasts. Studies on the EMMPRIN/CD147 showed that CD147 extracellular domain is involved in the induction of MMPs. To study the biological molecular function of HAb18G/CD147 extracellular domain (HAb18G/CD147-ED) on production of MMPs following mediated tumor cell invasion, we isolated four novel monoclonal anibodies (MAbs)-1B3, 3B3, HAb18Gedomab1, and HAb18Gedomab2-against HAb18G/CD147-ED by immunization of BALB/c mice with purified HAb18G/CD147-ED fragments, which were efficiently expressed in Escherichia coli. Gelatin zymography and Boyden chamber assays were used to identify the production of MMPs in the co-cultured human fibroblast and HCC cells, and to quantify the migrated cells in the presence of the generated MAbs. The results showed that two MAbs (1B3 and 3B3) inhibited [corrected] the secretion of MMP-2 and [corrected] the HCC cell invasion, whereas the other two MAbs (HAb18Gedomab1 and HAb18Gedomab2) had reverse function [corrected] FCM additive assay showed that four MAbs recognized different epitopes of HAb18G/CD147-ED. Taken together, the results suggest that various regions of HAb18G/CD147-ED participated in the regulation of MMP secretion.

Extracellular Matrix Metalloproteinase Inducer (CD147) Confers Resistance of Breast Cancer Cells to Anoikis through Inhibition of Bim

Overexpression of extracellular matrix metalloproteinase inducer (EMMPRIN or CD147), a member of the immunoglobulin family and a glycoprotein enriched on the surface of tumor cells, promotes invasion, metastasis, and growth and survival of malignant cells and confers resistance to some chemotherapeutic drugs. However, the molecular mechanisms underlying the actions of EMMPRIN are not fully understood. In this study we sought to determine whether EMMPRIN contributes to the malignant phenotype of breast cancer by inhibiting anoikis, a form of apoptosis induced by loss or alteration of cell-cell or cell-matrix anchorage, and to explore the signaling pathways involved. We found that in the absence of attachment, human breast carcinoma cells expressing high levels of EMMPRIN formed less compact aggregates with larger surface area and less fibronectin matrix assembly, had higher viability, and were resistant to anoikis. Knockdown of EMMPRIN expression by RNA interference (small interfering RNA or short hairpin RNA) sensitized cancer cells to anoikis, as demonstrated by activation of caspase-3, increased DNA fragmentation, and decreased cellular viability. Furthermore, we observed that the accumulation of Bim, a proapoptotic BH3-only protein, was reduced in EMMPRIN-expressing cells and that silencing of EMMPRIN expression elevated Bim protein levels and enhanced cellular sensitivity to anoikis. Treatment of cells with a MEK inhibitor (U0126) or proteasome inhibitor (epoxomicin) also up-regulated Bim accumulation and rendered cells more sensitive to anoikis. These results indicated that expression of EMMPRIN protects cancer cells from anoikis and that this effect is mediated at least in part by a MAP kinase-dependent reduction of Bim. Because anoikis deficiency is a key feature of neoplastic transformation and invasive growth of epithelial cancer cells, our study on the role of EMMPRIN in anoikis resistance and the mechanism involved underscores the potential of EMMPRIN expression as a prognostic marker and novel target for cancer therapy.

MCT-4, A511/Basigin and EF5 expression patterns during early chick cardiomyogenesis indicate cardiac cell differentiation occurs in a hypoxic environment

We have identified the presence of the hypoxia marker EF5 in the stage 4/5 chick heart fields. This suggests that cardiac cell differentiation occurs in a relatively anaerobic environment. Monocarboxylate transporter (MCT) studies in adult cardiac myocytes have demonstrated that MCTs catalyze proton-linked pyruvate and lactate transport activity. 5A11/Basigin is an ancillary protein that targets MCTs to the plasma membrane for their function. MCT-4 expression is most evident in cells with a high glycolytic rate associated with hypoxic energy production. Subsequent to the immunohistochemical localization of EF5 in the early heart field, we continued in our analysis during stages 5 to 12 for the expression of indicators of cellular glycolytic metabolism in the developing heart, such as MCT-4, MCT-1, and 5A11 (Basigin/CD147). Our observations indicate that MCT-4 and 5A11/Basigin are expressed early, in a differential left-right pattern, in the bi-lateral plate mesoderm, as the cardiac compartment is forming. At stage 11, MCT-4/5A11 continues to be highly expressed in the myocardial wall of the looping heart, but not in the dorsal mesocardium. RT-PCR analyses for MCT-1, -4, and 5A11 indicate that MCT-4 and 5A11 are expressed throughout precardiac, embryonic, and fetal stages in the heart. MCT-1 is first detected in the heart on embryonic day 3 and then remains expressed throughout development to hatching. These results indicate that cardiac precursor cells are equipped for differentiating in a hypoxic environment using anaerobic metabolism for energy production.

Expression of emmprin and matrix metalloproteinases (MMPs) in peripheral nerve sheath tumors: emmprin and membrane-type (MT)1-MMP expressions are associated with malignant potential

BACKGROUND

Matrix metalloproteinases (MMPs), including membrane-type (MT)-MMPs, correlate with biological aggressiveness in many carcinomas. However, their roles in peripheral nerve sheath tumors (PNSTs) have rarely been investigated.

MATERIALS AND METHODS

In this study, the immunohistochemical expression of 6 MMPs, their 3 inhibitors and emmprin, an MMP inducer, was examined in 14 schwannomas, 14 neurofibromas and 12 malignant peripheral nerve sheath tumors (MPNSTs) in relation to malignant potentials.

RESULTS

Higher expression levels (>3+) of emmprin and MT1-MMP were noted in 83.3% and 16.7% of MPNSTs, respectively, versus none in schwannomas and neurofibromas (p<0.0001). The overall expression rate (1-4+) of MT1-MMP was 58.3% in MPNSTs versus 7.1% in both schwannomas and neurofibromas (p=0.0093). Gelatinase A (MMP-2) showed higher expression levels (>3+) in all the tumors without significant differencies. Moreover, the expression patterns of MMP-1 and gelatinase B (MMP-9) could divide PNSTs into two groups: schwannoma versus neurofibroma/MPNST. Higher expression levels (>3+) of MMP-9 were observed in 50% of schwannomas versus none in neurofibromas and MPNSTs, while those of MMP-1 were found in 35.7% of neurofibromas and 66.7% of MPNSTs versus none in schwannomas. RECK was the main inhibitor expressed in these 3 tumors, with no significant differences.

CONCLUSION

These results suggest that emmprin and MT1-MMP may be malignant potential-related proteins in PNSTs, and that MMP-1 and 9 may help differentiation between schwannoma and neurofibroma, especially in their plexiform types.

Red blood cell age determines the impact of storage and leukocyte burden on cell adhesion molecules, glycophorin A and the release of annexin V

The influence of the age of the red blood cell (RBC) within its 120-day lifecycle at the time of blood donation on the RBC storage lesion is not well understood. Expression of cell adhesion molecules (CAMs) (CD44, CD47, CD58 and CD147), glycophorin A (GPA) and phosphatidylserine (PS) on young and old RBCs density separated prior to storage of the RBC concentrate was determined by flow cytometry. Older RBCs showed significantly reduced expression of GPA throughout storage and CD44 and CD147 from Day 28 onwards compared to young RBCs. Storage in the presence of leukocytes caused a significant decline in the expression of CD44, CD58, CD147 and GPA, whereas RBCs that were pre-storage leukocyte depleted maintained a relatively consistent level of expression throughout storage. PS was not detected at the external RBC membrane of young or old RBCs during storage. Increased levels of annexin V were detected in the supernatant of RBCs stored in the presence of leukocytes, with significantly greater supernatant levels found for old RBCs compared to young RBCs. These findings provide new insight into the RBC storage lesion and indicate that RBC age at the time of donation impacts upon the quality of stored RBC concentrates.

C-reactive protein-induced upregulation of extracellular matrix metalloproteinase inducer in macrophages: inhibitory effect of fluvastatin

OBJECTIVE

Extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase (MMP)-9 were reported to be expressed at the macrophage-rich area in human coronary atherosclerotic plaque. We examined whether C-reactive protein (CRP) activates macrophages to express EMMPRIN and MMP-9 in vitro and whether statins inhibit it.

METHODS AND RESULTS

Rat peritoneal macrophages were collected by peritoneal lavage, and were incubated in the presence or absence of CRP. CRP at 5 microg/ml increased the gene expression of EMMPRIN relative to GAPDH, measured by RT-PCR, by 1.67+/-0.07 fold at 24 h and by 1.85+/-0.49 fold at 48 h (both p<0.05). The gene expression of MMP-9 in the presence of CRP at 5 microg/ml was followed by 1.36+/-0.11 fold increase at 24 h and by 3.95+/-0.81 fold at 48 h (both p<0.05). CRP at 5 microg/ml for 48 h increased by 6 fold MMP-9 activity, measured by zymography, without affecting tissue inhibitor of metalloproteinases-1. Boiled CRP at 5 mug/ml for 48 h unaffected MMP-9 activity. Fluvastatin blocked the CRP-induced increases in EMMPRIN and MMP-9 expression and activity. Diphenylene iodonium, an inhibitor of NADPH oxidase, had a similar effect on MMP-9 activity. Fluvastatin suppressed the CRP-induced increases in 8-epi-prostaglandin F(2alpha) levels in the condition media.

CONCLUSIONS

CRP is an activator for macrophages to enhance EMMPRIN and MMP-9 expression. Fluvastatin inhibits them presumably through its antioxidant effect.

Correlation of reversion-inducing cysteine-rich protein with kazal motifs (RECK) and extracellular matrix metalloproteinase inducer (EMMPRIN), with MMP-2, MMP-9, and survival in colorectal cancer

mRNA, and latent and active levels MMP-2 and -9 were higher in tumor tissue compared to normal tissue from 63 patients with colorectal cancer, whereas RECK and EMMPRIN levels were lower. Correlations between mRNA, latent, and active MMP were particular high for MMP-2 in tumor tissue (R(s)=0.6-0.8, P<0.001). For active MMP-2, but not for MMP-9, a significant negative partial correlation (R(p)=-0.440, P<0.001) for RECK was found in tumor tissue, which was confirmed by linear regression analysis. In exploratory survival analyses we found that in patients with localized disease the RECK level in normal or tumor tissue had a significant (P=0.017) association with overall survival.

Expression of CD147 on monocytes/macrophages in rheumatoid arthritis: its potential role in monocyte accumulation and matrix metalloproteinase production

Monocytes/macrophages play an important role in rheumatoid arthritis (RA) pathogenesis. They can activate fibroblasts through many molecules, including IL-1 and tumor necrosis factor-alpha, but there have been very few reports on the role of CD147 in RA. In our study, the results of flow cytometry reveal that the mean fluorescence intensity (MFI) of CD147 expression on CD14+ monocytes of peripheral blood from RA patients was higher than that in normal control and ankylosing spondylitis (AS) patients. The MFI of CD147 expression on the CD14+ monocytes in RA synovial fluid was higher than that in RA peripheral blood. Immunohistochemical staining shows that CD147 expression in RA synovium correlated with matrix metalloproteinase (MMP)-1 expression. A double immunofluorescent assay shows that CD147 was expressed on CD68+ cells in RA synovium. The potential role of CD147 in cyclophilin A (CyPA)-mediated cell migration was studied using a chemotaxis assay in vitro and it was found that the addition of anti-CD147 antibody or a CD147 antagonistic peptide significantly decreased the chemotactic index of the mononuclear cells. The role of CD147 in MMP production and cell invasion in vitro were studied through the co-culture of human CD14+ monocytes or monocytic line THP-1 cells and human fibroblasts, as well as by gel zymography and an invasion assay. Significantly elevated release and activation of MMP-9 and/or MMP-2 were seen in the co-culture of human monocytes/THP-1 cells and fibroblasts compared with cultures of the cells alone. An increased number of cells invading through the filters in the invasion assays was also observed in the co-cultured cells. The addition of CD147 antagonistic peptide had some inhibitory effect, not only on MMP production but also on cell invasion in the co-culture. Our study demonstrates that the increased expression of CD147 on monocytes/macrophages in RA may be responsible for elevated MMP secretion, cell invasion and CyPA-mediated cell migration into the joints, all of which may contribute to the cartilage and bone destruction of RA. These findings, together with a better understanding of CD147, CyPA and RA, will help in the development of innovative therapeutic interventions for RA.

[Expression of extracellular matrix metalloproteinase inducer in laryngeal squamous cell carcinoma]

OBJECTIVE

To study the expression of extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) in human laryngeal squamous cell carcinoma and the relationship between the expressions and the clinical features.

METHOD

The expressions of EMMPRIN were detected by the method of immunohistochemical SP in 42 specimens taken from the patients with laryngeal squamous cell carcinoma, 28 specimens from precancerous lesion and 20 specimens from normal laryngeal tissues.

RESULT

Positive expressions rates of EMMPRIN in the specimens from laryngeal squamous cell carcinoma, precancerous lesion and normal laryngeal tissues were 88.1%, 57.1% and 5.0%, the intensive expressions rates were 52.4%, 10.7% and 0%. There were significant differences among laryngeal squamous cell carcinoma, precancerous lesion and normal laryngeal tissues. In laryngeal squamous cell carcinoma, the expressions of EMMPRIN had a significant relevance to clinical phases and lymph node metastasis. The intense expressions rate in phase II-IV was much higher than that in phase I-II, while the intense expressions rate in cases with lymph node metastasis was higher than in those cases without lymph node metastasis.

CONCLUSION

The expression of EMMPRIN has relationship with the pathological type of laryngeal tumor and has relevance to clinical stage and lymph node metastasis of laryngeal carcinoma.

[Non-fused expression of HAb18GEF by reducing stability of translational initiation region in mRNA]

To express the extracellular fragement of hepatoma associated antigen HAbl8G(HAb18GEF) in E. coli efficiently in a non-fusing way, the cDNA of HAb18GEF gene was inserted into prokaryotic expression vector pET21a + . The secondary structure and codon adaptation of translational initiation region (TIR, from-30 to + 39) in mRNA of recombinant vector HAb18GEF/ pET21a + was predicted simultaneously by computer-aided design. Stable Stem-Loop structures and many low-usage codons were detected in mRNA-TIR of non-optimized recombinant HAb18GEF/pET21a + vector. The stability of mRNA-TIR in recombinant HAb18GEF/pET21a + vector was reduced with following methods: (1) optimization of secondary structure (2) optimization of codon adaptation. These optimization were realized by non-continual site-directed mutagenesis without changing any amino acid sequence in TIR. After being checked through restriction endonuclease digestion and confirmed through nucleotide sequencing, the pre-optimized and post-optimized recombinant vectors were transformed into competent E. coli JM109-DE3. The resulted recombinant clones were selected randomly and induced by IPTG at 37 degrees C. The induced production of these recombinants was analyzed by SDS-PAGE, indirect ELISA, Western blot, and cell fractionation assay. The amount of HAb18GEF mRNA was also detected by RNA dot blot between pre-optimized recombinant and post-optimized recombinant. The results revealed that recombinant non-fused vectors HAb18GEF/pET21a + were successfully constructed and optimized in the secondary structure and codon adaptation of TIR respectively. The HAb18GEF was expressed efficiently in a non-fusing way in recombinant E. coli by secondary structure optimization or codon adaptation optimization. Whereas, no expression of HAb18GEF was detected in pre-optimized recombinants. The non-fused expression products-HAb18GEF, mainly as inclusion body in E. coli, yielded highly above 29.3%. A trait of expression HAb18GEF was also detected both in intermembrane space and in culture medium due to over-expression and cell leakage. Difference in non-fused expression level of HAb18GEF between secondary structure optimization and codon adaptation optimization was negligible. No difference in amount of transcribed mRNA of HAb18GEF between the pre-optimized and the post-optimized recombinants was detected. To sum up, it's feasible to express hepatoma associated antigen HAb18GEF in a non-fusing way by reducing the stability of TIR in mRNA.