AKAP-9 promotes colorectal cancer development by regulating Cdc42 interacting protein 4.

Our previous studies have shown that PRKA kinase anchor protein 9 (AKAP-9) is involved in colorectal cancer (CRC) cell proliferation and migration in vitro. However, whether or not AKAP-9 is important for CRC development or metastasis in vivo remains unknown. In the present study, we found that AKAP-9 expression was significantly higher in human colorectal cancer tissues than the paired normal tissues. In fact, AKAP-9 level correlated with the CRC infiltrating depth and metastasis. Moreover, the higher AKAP-9 expression was associated with the lower survival rate in patients. In cultured CRC cells, knockdown of AKAP-9 inhibited cell proliferation, invasion, and migration. AKAP-9 deficiency also attenuated CRC tumor growth and metastasis in vivo. Mechanistically, AKAP-9 interacted with cdc42 interacting protein 4 (CIP4) and regulated its expression. CIP4 levels were interrelated to the AKAP-9 level in CRC cells. Functionally, AKAP-9 was essential for TGF-ß1-induced epithelial-mesenchymal transition of CRC cells, and CIP4 played a critical role in mediating the function of AKAP-9. Importantly, CIP4 expression was significantly up-regulated in human CRC tissues. Taken together, our results demonstrated that AKAP-9 facilitates CRC development and metastasis via regulating CIP4-mediated epithelial-mesenchymal transition of CRC cells.

NDRG1 attenuates epithelial-mesenchymal transition of nasopharyngeal cancer cells via blocking Smad2 signaling.

N-myc downstream-regulated gene 1 (NDRG1) has been implicated in tumorigenesis and metastasis in different cancers. However, its role in nasopharyngeal carcinoma remains unknown. We found that NDRG1 expression level was high in nasopharyngeal cancer 5-8F cells but low in 5-8F-LN cells with lymphatic metastasis potential. Knockdown of NDRG1 by shRNA promoted 5-8F cell proliferation, migration, and invasion in vitro and its tumorigenesis in vivo. Moreover, NDRG1 deficiency induced an epithelial-mesenchymal transition (EMT) of 5-8F cells as shown by an attenuation of E-cadherin and an induction of N-cadherin and vimentin expression. NDRG1 knockdown also enhanced Smad2 expression and phosphorylation. Smad2 signaling was attenuated in 5-8F cells but was significantly activated in 5-8F-LN cells. Knockdown of Smad2 restored E-cadherin but attenuated N-cadherin expression in NDRG1-deficient 5-8F cells, suggesting a reduction of EMT. Consistently, blockade of Smad2 in 5-8F-LN cells increased E-cadherin while diminishing N-cadherin and vimentin expression. These data indicate that Smad2 mediates the NDRG1 deficiency-induced EMT of 5-8F cells. In tumors derived from NDRG1-deficient 5-8F cells, E-cadherin expression was inhibited while vimentin and Smad2 were increased in a large number of cancer cells. Most importantly, NDRG1 expression was attenuated in human nasopharyngeal carcinoma tissues, resulted in a lower survival rate in patients. The NDRG1 was further decreased in the detached nasopharyngeal cancer cells, which was associated with a further reduced survival rate in patients with lymphatic metastasis. Taken together, these results demonstrated that NDRG1 prevents nasopharyngeal tumorigenesis and metastasis via inhibiting Smad2-mediated EMT of nasopharyngeal cells.

MALAT1 promotes colorectal cancer cell proliferation/migration/invasion via PRKA kinase anchor protein 9.

Our previous studies have shown that the 3' end of metastasis associated lung adenocarcinoma transcript 1 (MALAT1) is involved in colorectal cancer (CRC) cell proliferation and migration/invasion in vitro. The role and mechanism of MALAT1 in CRC metastasis in vivo, however, remain largely unknown. In the present study, we found that MALAT1 was up-regulated in human primary CRC tissues with lymph node metastasis. Overexpression of MALAT1 via RNA activation promoted CRC cell proliferation, invasion and migration in vitro, and stimulated tumor growth and metastasis in mice in vivo. Conversely, knockdown of MALAT1 inhibited CRC tumor growth and metastasis. MALAT1 regulated at least 243 genes in CRC cells in a genome-wide expression profiling. Among these genes, PRKA kinase anchor protein 9 (AKAP-9) was significantly up-regulated at both mRNA and protein levels. AKAP-9 was highly expressed in CRC cells with metastatic potential and human primary CRC tissues with lymph node metastasis, but not in normal cells or tissues. Importantly, knockdown of AKAP-9 blocked MALAT1-mediated CRC cell proliferation, migration and invasion. These data indicate that MALAT1 may promote CRC tumor development via its target protein AKAP-9.

A new method for predicting the prognosis of colorectal cancer patients through a combination of multiple tumor-associated macrophage markers at the invasive front.

Tumor-associated macrophages (TAMs) are closely related to tumorigenesis and metastasis of multiple cancer types. The infiltration of TAMs is used for predicting the prognosis of cancers, including colorectal cancer (CRC). However, the density and prognostic significance of M1 and M2 TAM phenotypes in the intratumor versus the invasive front (IF) are largely unknown in CRC. In this study, CD68 was selected as a general marker of TAMs, CD11c, NOS2 and CXCL10 as markers for M1 phenotype and CD163, CD206, CD115 as markers for M2 phenotype. Firstly, immunohistochemistry staining and double-labeling immunofluorescence staining showed that M1 molecular markers (NOS2, CXCL10, CD11c) were lowly expressed at both IF and intratumor, while M2 molecular markers (CD163, CD206, CD115) were highly expressed mainly at IF. Moreover, we also demonstrated that three M1 molecular markers including NOS2, CXCL10 and CD11c were correlated to each other. Meanwhile, three M2 molecular markers including CD163, CD206, and CD115 were also correlated to each other. Patients with low expression of three M1 molecular markers (NOS2/CXCL10/CD11c) exhibited low overall survival (OS) rate, whereas patients with high expression of three M2 molecular markers (CD163/CD206/CD115) exhibited low OS rate. We also observed that the prognostic value of treble markers combination (NOS2/CXCL10/CD11c or CD163/CD206/CD115) was superior to that of single marker. Together, our results reveal the combination of treble TAMs markers (NOS2/CXCL10/CD11c or CD163/CD206/CD115) could better evaluate the prognosis of CRC patients, which might be used as a more comprehensive method for predicting the prognosis of CRC patients.

Tumor bud-derived CCL5 recruits fibroblasts and promotes colorectal cancer progression via CCR5-SLC25A24 signaling.

BACKGROUND: Tumor budding is included in the routine diagnosis of colorectal cancer (CRC) and is considered a tumor prognostic factor independent of TNM staging. This study aimed to identify the fibroblast-mediated effect of tumor bud-derived C-C chemokine ligand 5 (CCL5) on the tumor microenvironment (TME). METHODS: Recruitment assays and a human cytokine array were used to detect the main cytokines that CRC tumor buds secrete to recruit fibroblasts. siRNA transfection and inhibitor treatment were used to investigate the role of fibroblast CCL5 receptors in fibroblast recruitment. Subsequently, transcriptome sequencing was performed to explore the molecular changes occurring in fibroblasts upon stimulation with CCL5. Finally, clinical specimens and orthotopic xenograft mouse models were studied to explore the contribution of CCL5 to angiogenesis and collagen synthesis. RESULTS: Hematoxylin-eosin staining and immunochemistry revealed a higher number of fibroblasts at the invasive front of CRC tissue showing tumor budding than at sites without tumor budding. In vitro experiments demonstrated that CCL5 derived from tumor buds could recruit fibroblasts by acting on the CCR5 receptors on fibroblasts. Tumor bud-derived CCL5 could also positively regulate solute carrier family 25 member 24 (SLC25A24) expression in fibroblasts, potentially activating pAkt-pmTOR signaling. Moreover, CCL5 could increase the number of α-SMAhigh CD90high FAPlow fibroblasts and thus promote tumor angiogenesis by enhancing VEGFA expression and making fibroblasts transdifferentiate into vascular endothelial cells. Finally, the results also showed that CCL5 could promote collagen synthesis through fibroblasts, thus contributing to tumor progression. CONCLUSIONS: At the invasive front of CRC, tumor bud-derived CCL5 can recruit fibroblasts via CCR5-SLC25A24 signaling, further promoting angiogenesis and collagen synthesis via recruited fibroblasts, and eventually create a tumor-promoting microenvironment. Therefore, CCL5 may serve as a potential diagnostic marker and therapeutic target for tumor budding in CRC.

Gene expression profile changes and possible molecular subtypes in differentiated-type nonkeratinizing nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a human malignant tumor with a high incidence and a poor prognosis in Southern China and South-eastern Asia. In this study, we comprehensively analyzed the gene expression profiles in 24 samples of primary differentiated-type nonkeratining NPC (DNK-NPC) tissues, 24 samples of normal nasopharyngeal tissues and 4 DNK-NPC cell lines using cDNA microarray technology and bioinformatics methods. We found expression level of some genes was wildly alerted in the DNK-NPC samples. In addition, our hierarchical clustering analysis revealed 2 distinctive subtypes of gene expression patterns in DNK-NPC tissue samples. The discriminator genes were identified using a signal-to-noise (S(2)N) algorithm by permuting of the data set 10,000 times. To further characterize the clinical relevance of the tumor subtypes, we evaluated a surrogate marker, CCND2, differentially expressed between the 2 tumor subgroups by using immunohistochemistry in an independent set of 137 DNK-NPC samples. CCND2 was highly expressed in the subgroups with "aggressive" features and was associated with T classification (p = 0.006) and clinical stage (p = 0.013). Patients with high level of CCND2 expression had poorer overall survival than those with low level (p = 0.034). Our results suggest that DNK-NPC can be classified into 2 subtypes based on gene expression patterns, which can be used in determining prognosis and treatment of the tumor.

MYH9-dependent polarization of ATG9B promotes colorectal cancer metastasis by accelerating focal adhesion assembly.

Tumour metastasis is a major reason accounting for the poor prognosis of colorectal cancer (CRC), and the discovery of targets in the primary tumours that can predict the risk of CRC metastasis is now urgently needed. In this study, we identified autophagy-related protein 9B (ATG9B) as a key potential target gene for CRC metastasis. High expression of ATG9B in tumour significantly increased the risk of metastasis and poor prognosis of CRC. Mechanistically, we further find that ATG9B promoted CRC invasion mainly through autophagy-independent manner. MYH9 is the pivotal interacting protein for ATG9B functioning, which directly binds to cytoplasmic peptide segments aa368-411 of ATG9B by its head domain. Furthermore, the combination of ATG9B and MYH9 enhance the stability of each other by decreasing their binding to E3 ubiquitin ligase STUB1, therefore preventing them from ubiquitin-mediated degradation, which further amplified the effect of ATG9B and MYH9 in CRC cells. During CRC cell invasion, ATG9B is transported to the cell edge with the assistance of MYH9 and accelerates focal adhesion (FA) assembly through mediating the interaction of endocytosed integrin ß1 and Talin-1, which facilitated to integrin ß1 activation. Clinically, upregulated expression of ATG9B in human CRC tissue is always accompanied with highly elevated expression of MYH9 and associated with advanced CRC stage and poor prognosis. Taken together, this study highlighted the important role of ATG9B in CRC metastasis by promoting focal adhesion assembly, and ATG9B together with MYH9 can provide a pair of potential therapeutic targets for preventing CRC progression.

Celecoxib enhances the inhibitory effect of cisplatin on Tca8113 cells in human tongue squamous cell carcinoma in vivo and in vitro.

BACKGROUND: Overexpression of cyclooxygenase-2 (COX-2) is associated with carcinogenesis, invasiveness, and metastasis of malignant tumors. Inhibition of COX-2 is one hot topic of research in prevention and treatment of malignant tumors. Because of the selective and specific inhibition on the activity of COX-2, the roles of celecoxib in prevention and treatment of tumors have attracted broad attention in recent years. In this study, we investigated the inhibitory effect of celecoxib combined with cisplatin on the proliferation of human tongue squamous cell carcinoma cell line Tca8113 in vivo and in vitro. METHODS: Human tongue squamous cell carcinoma tumor cells Tca8113 and a mouse model with Tca8113 cells were used to study the growth inhibition of cisplatin enhanced by celecoxib. Drug treatment of Tca8113 in vitro and mice bearing xenografts in vivo were used. The level of COX-2 expression was detected by Western blotting. Sensitivity of cells to drug treatment was analyzed by MTT assay. RESULTS: Treatment of Tca8113 cells with cisplatin (CDDP) had less effect on the expression of COX-2, whereas the COX-2 expression was significantly down-regulated after treatment with celecoxib alone or in combination with CDDP for 24 h. In addition, the combination of celecoxib with CDDP was also able to inhibit the Tca8113 line heterotransplanted in Balb/c nude mice. CONCLUSIONS: Those findings indicate that a low dose of celecoxib could augment CDDP-induced growth inhibition of Tca8113 cells and its xenograft in Balb/c nude mice.

Gastric aggressive fibromatosis: report of a case and review of the literature.

OBJECTIVES: To describe a rare case of aggressive fibromatosis of the stomach and discuss the differential diagnoses. METHODS: A 47-year-old man presented with nonspecific abdominal pain. Gastroscopy revealed stomach wall swelling. An antral gastrectomy was performed. Histological examination revealed spindle-shaped cells and morphology typical of aggressive fibromatosis. We performed a literature search to identify conditions with features similar to those of aggressive fibromatosis. RESULTS: Aggressive fibromatosis does not metastasize, but it is locally invasive and has a tendency to relapse; however, our patient has not had recurrence > 1 year after surgery. Aggressive fibromatosis of the stomach may be confused with an inflammatory fibroid polyp, a gastrointestinal stromal tumor, schwannoma, leiomyoma, inflammatory myofibroblastic tumor, scirrhous carcinoma of the stomach, follicular dendritic cell sarcoma, inflammatory malignant fibrous histiocytoma, myofibroma/myofibromatosis, and solitary fibrous tumor of the stomach. CONCLUSIONS: Aggressive fibromatosis of the stomach is a rare spindle cell tumor that must be differentiated from a variety of conditions.

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.

Role of TGFß3-Smads-Sp1 axis in DcR3-mediated immune escape of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a leading cause of tumour-associated mortality worldwide, but no significant improvement in treating HCC has been reported with currently available systemic therapies. Immunotherapy represents a new frontier in tumour therapy. Therefore, the immunobiology of hepatocarcinoma has been under intensive investigation. Decoy receptor 3 (DcR3), a member of the tumour necrosis factor receptor (TNFR) superfamily, is an immune suppressor associated with tumourigenesis and cancer metastasis. However, little is known about the role of DcR3 in the immunobiology of hepatocarcinoma. In this study, we found that overexpression of DcR3 in HCC is mediated by the TGFß3-Smad-Sp1 signalling pathway, which directly targets DcR3 promoter regions. Moreover, overexpression of DcR3 in HCC tissues is associated with tumour invasion and metastasis and significantly promotes the differentiation and secretion of Th2 and Treg cells while inhibiting the differentiation and secretion of Th1 cells. Conversely, knockdown of DcR3 expression in HCC significantly restored the immunity of CD4+ T cells. Inhibition of DcR3 expression may provide a novel immunotherapeutic approach to restoring immunity in HCC patients.

[Monitoring changes of serum protein markers in metastatic colorectal carcinoma model].

OBJECTIVE: To investigate the changes of several protein markers in a metastatic colorectal carcinoma model by serum proteomic analysis. METHODS: The pEGFP-N1 plasmid with enhanced expression of green fluorescence protein (EGFP) was transfected into human colon carcinoma cell line SW480 to obtain a stable SW480-EGFP cell line, the SW480-EGFP cells were then injected subcutaneously into nude mice. The harvested tumor cells were implanted orthotopically into the colon of the nude mice. Real-time tumor growth and metastasis formation were visualized by whole-body fluorescent imaging system. Serum samples at different metastatic stages were collected and differential proteomic profiles were investigated by two-dimensional gel electrophoresis (2DE) and matrix-assisted laser absorption/ionization time of flight mass spectrometry (MALDI-TOF MS). RESULTS: The SW480- EGFP cells enabled to express EGFP stably. The rates of subcutaneous and orthotropic tumor formation were 100%. The metastasis rates to local lymph nodes, liver and lung were 100%, 40% and 30%, respectively. Furthermore, 5 differentially expressed proteins were analyzed by serum proteome technologies, including haptoglobin alpha chain, apolipoprotein E, apolipoprotein A-IV, Ig kappa chain V region chain L and transferrin. CONCLUSIONS: Visualized metastatic model of colorectal carcinoma was successfully established. Several differentially expressed serum proteins collected at different stages after the occurrence of metastasis were identified. These differentially expressed proteins may be candidate serum biomarkers for diagnosis and therapeutic evaluation of colorectal carcinoma metastasis.

RGC32 induces epithelial-mesenchymal transition by activating the Smad/Sip1 signaling pathway in CRC.

Response gene to complement 32 (RGC32) is a transcription factor that regulates the expression of multiple genes involved in cell growth, viability and tissue-specific differentiation. However, the role of RGC32 in tumorigenesis and tumor progression in colorectal cancer (CRC) has not been fully elucidated. Here, we showed that the expression of RGC32 was significantly up-regulated in human CRC tissues versus adjacent normal tissues. RGC32 expression was significantly correlated with invasive and aggressive characteristics of tumor cells, as well as poor survival of CRC patients. We also demonstrated that RGC32 overexpression promoted proliferation, migration and tumorigenic growth of human CRC cells in vitro and in vivo. Functionally, RGC32 facilitated epithelial-mesenchymal transition (EMT) in CRC via the Smad/Sip1 signaling pathway, as shown by decreasing E-cadherin expression and increasing vimentin expression. In conclusion, our findings suggested that overexpression of RGC32 facilitates EMT of CRC cells by activating Smad/Sip1 signaling.

[Expression and diagnostic application of C4.4A protein in squamous cell carcinoma and adenocarcinoma].

OBJECTIVE: To investigate the diagnostic utility of C4.4A gene expression in discriminating a squamous cell carcinoma (SCC) from an adenocarcinoma by immunohistochemistry. METHODS: Immunohistochemical staining was performed to detect the expression of C4.4A protein in 157 cases of SCC and 177 cases of adenocarcinoma of various organs. RESULTS: Overall, 141 of 157 cases of SCC strongly expressed C4.4A protein. In contrast, only 8 of 177 adenocarcinomas showed partial or scattered cell expression of C4.4A protein. The statistic difference between the two groups was highly significant (chi(2) = 244.93, P = 0.000), and also when the tumors were stratified according to the degree of differentiation (P = 0.000). CONCLUSION: C4.4A protein expression may serve as a valuable tumor marker in discriminating a squamous cell carcinoma from an adenocarcinoma, and therefore, may greatly facilitate the differential diagnosis of an epithelial malignancy.

DcR3 induces epithelial-mesenchymal transition through activation of the TGF-ß3/SMAD signaling pathway in CRC.

Decoy receptor 3 (DcR3), a novel member of the tumor necrosis factor receptor (TNFR) family, was recently reported to be associated with tumorigenesis and metastasis. However, the role of DcR3 in human colorectal cancer (CRC) has not been fully elucidated. In this study, we found that DcR3 expression was significantly higher in human colorectal cancer tissues than in paired normal tissues, and that DcR3 expression was strongly correlated with tumor invasion, lymph node metastases and poor prognoses. Moreover, DcR3 overexpression significantly enhanced CRC cell proliferation and migration in vitro and tumorigenesis in vivo. Conversely, DcR3 knockdown significantly repressed CRC cell proliferation and migration in vitro, and DcR3 deficiency also attenuated CRC tumorigenesis and metastasis in vivo. Functionally, DcR3 was essential for TGF-ß3/SMAD-mediated epithelial-mesenchymal transition (EMT) of CRC cells. Importantly, cooperation between DcR3 and TGF-ß3/SMAD-EMT signaling-related protein expression was correlated with survival and survival time in CRC patients. In conclusion, our results demonstrate that DcR3 may be a prognostic biomarker for CRC and that this receptor facilitates CRC development and metastasis by participating in TGF-ß3/SMAD-mediated EMT of CRC cells.

Long non-coding RNA MALAT1 increases AKAP-9 expression by promoting SRPK1-catalyzed SRSF1 phosphorylation in colorectal cancer cells.

Our earlier findings indicate that the long non-coding RNA MALAT1 promotes colorectal cancer (CRC) cell proliferation, invasion and metastasis in vitro and in vivo by increasing expression of AKAP-9. In the present study, we investigated the molecular mechanism by which MALAT1 enhances AKAP9 expression in CRC SW480 cells. We found that MALAT1 interacts with both SRPK1 and SRSF1. MALAT1 increases AKAP-9 expression by promoting SRPK1-catalyzed SRSF1 phosphorylation. Following MALAT1 knockdown, overexpression of SRPK1 was sufficient to restore SRSF1 phosphorylation and AKAP-9 expression to a level that promoted cell proliferation, invasion and migration in vitro. Conversely, SRPK1 knockdown after overexpression of MALAT1 in SW480 cells diminished SRSF1 phosphorylation and AKAP-9 expression and suppressed cell proliferation, invasion and migration in vitro. These findings suggest MALAT1 increases AKAP-9 expression by promoting SRPK1-catalyzed SRSF1 phosphorylation in CRC cells. These results reveal a novel molecular mechanism by which MALAT1 regulates AKAP-9 expression in CRC cells.

Effects of KAI1/CD82 on biological behavior of human colorectal carcinoma cell line.

AIM: To investigate the effects of KAI1/CD82 on biological behavior of colorectal carcinoma cells. METHODS: KAI1 cDNA was transfected into highly malignant colorectal carcinoma cell line, LoVo, which had low level of endogenous KAI1 expression, and established stable transfectant clones with high KAI1/CD82 expression. The cell-cell adhesion, cell aggregation, cell-matrix adhesion and cell invasion assay were performed to determine whether KAI1 transfectant could have an effect on proliferation, adhesion and tumor metastasis in comparison with the control transfectant cells. RESULTS: KAI1 expression did not alter in vitro cell proliferation. But the KAI1 transfectant cells exhibited significantly increased homotypic cell-cell adhesion and cell aggregation in comparison with the control transfectant cells(P<0.05). Furthermore, KAI1 expression significantly suppressed the cell adhesion to extracellular matrix components and in vitro cell invasion in KAI1-transfected LoVo cells. The data indicated that KAI1 expression significantly suppressed the metastatic potential of KAI1-transfected LoVo cells. CONCLUSION: Our results suggest that KAI1 might function as a negative regulator of colorectal carcinoma metastasis.

[Association of dendritic cell infiltration with prognosis and lymph node metastasis of renal cell carcinoma].

OBJECTIVE: To investigate the relation of dendritic cell (DC) infiltration to the prognosis and lymph node metastasis of renal cell carcinoma. METHOD: The tissue specimens were obtained from 69 patients with renal cell carcinomas, who were treated surgically from 1994 to 2000 in our hospital and followed up for over 2 years. ABC immunohistochemical method using S-100 protein antibody was employed to examine the tumor tissues and the DCs was counted. RESULTS: The patients showing no signs of tumor recurrence within 2 years postoperatively had significantly greater number of S-100(+) DCs in the tumor tissues than that of patients with recurrence in 2 years (61.3 +/- 14.7/mm(2) vs 31.4 +/- 11.6/mm(2)). The number of S-100(+) DCs of the group with lymph node metastasis was much lower than that of the group without the metastasis (28.8 +/- 10.4/mm(2) vs 62.6 +/- 13.5/mm(2)). CONCLUSION: The density of DC infiltration is closely related to the prognosis and lymph node metastasis, which may be used as a good indicator for prognostic assessment of renal cell carcinoma.

[Effect of tumor suppressor gene KAI1 on the biological behaviors of human colorectal carcinoma].

OBJECTIVE: To determine whether the expression of tumor suppressor gene KAI1 can suppress the invasive or metastatic ability of colorectal carcinoma cells. METHODS: KAI1 cDNA was transfected into highly malignant colorectal carcinoma cell line LoVo, which had low levels of endogenous KAI1 expression. The expressions of KAI1 mRNA and protein were determined by immunohistochemistry and in situ hybridization, and the biological behaviors of the KAI1-transfected LoVo cells were investigated by cell-cell adhesion, cell-matrix adhesion and invasion assays. RESULTS: KAI1 expression significantly suppressed the metastatic potential of KAI1-transfected LoVo cells, whose metastasis suppression was correlated with the increased adhesion to homotypic cells and reduced tumor adhesion to extracellular matrix components. KAI1 expression significantly suppressed the in vitro cell invasion in KAI1-transfected LoVo cells. CONCLUSION: KAI1 might function as inhibitor of colorectal carcinoma metastasis.

[Changes of biological characteristics of colon carcinoma cell line - LoVo induced by Kai1/CD82 transfection].

OBJECTIVE: To study the influence of Kai1/CD82 transfection on the growth, adherence, separation and invasion potential of LoVo colon carcinoma cell line. METHODS: Kai1/CD82 cDNA was transfected into LoVo cells, and a stable expressing clone was established. In vitro methodology was used to obtain the growth curve and also to detect the adherence, separation and invasion potential of the transfected LoVo cells, in comparison with those of control cells without transfection. RESULTS: Compared with the control, no change was observed in the growth pattern of transfected LoVo cells. The numbers of adherent cells in the two groups were 0.08, 0.63, 0.83, 0.91 (x 10(5)) for the transfected cells and 0.04, 0.48, 0.71, 0.82 (x 10(5)) for the control cells respectively after 10, 20, 30, 40 minutes culture with shaking. The difference at 20, 30 and 40 minutes was statistically significant (P < 0.05). The separation rates of each group were 13%, 20%, 53% for the transfected cells and 11%, 28%, 60% for the control cells, respectively after 5, 10, 15 minutes culture with shaking. The difference at 10 and 15 minutes was statistically significant (P < 0.05). The aggregation rate of the transfected cells was higher than that of the control cells after culture with mild shaking for 5 hours (64.8% vs. 58.6%, P < 0.05). After co-incubation with endothelium cells ECV304, the number of invading cells decreased more in the transfected cells than that in the control cells (6.33/field and 17.67/field, P < 0.05). CONCLUSION: Transfection expression of Kail/CD82 into LoVo cell line results in an increase of cell adherence and aggregation, but a diminished capability of separation and invasion, suggesting that the expression of Kai1/CD82 gene may inhibit the metastatic potential of colon carcinoma.