miRNA-633 and KAI1 as Potential Biomarkers of Malignant Melanoma with Gastric Cancer.

OBJECTIVE: Malignant melanoma with gastric cancer is one of the most malignant tumors. However, there have been no reports on the effects of KAI1 and miRNA-633 on the survival and prognosis of patients with malignant melanoma with gastric cancer. METHODS: Fifty patients with malignant melanoma and gastric cancer were collected from October 2017 to December 2019. The clinical parameters included clinical information, such as sex, age, tumor size, and tumor staging. RT-qPCR was used to detect the expression of KAI1 and miRNA- 633. The role of KAI1 and miRNA-633 on the overall survival of melanoma was explored by the Pearson chi-square test, Spearman-rho correlation test, Univariate and multivariate cox regression analyses, and Kaplan-Meier method. Furthermore, the bioinformatic analysis was used to verify the role of KAI1 and miRNA-633 on malignant melanoma with gastric cancer. RESULTS: The expression of KAI1 and miRNA-633 was significantly related with the tumor size and staging of tumor (p<0.05) based on the Pearson chi-square test. Spearman's correlation coefficient displayed that KAI1 was significantly correlated with the miRNA-633 (ρ=-0.439, p=0.001). The result of multivariate cox proportional regression analysis showed that KAI1 (HR =0.109, 95% CI: 0.031-0.375, p< 0.001), and miRNA-633 (HR = 13.315, 95% CI: 3.844-46.119, p<0.001) were significantly associated with overall survival. CONCLUSION: The low expression level of KAI1 and high expression of miRNA-633 are significantly correlated with the poor overall survival prognosis of malignant melanoma with gastric cancer, to provide a basis for KAI1 and miRNA-633 to become novel molecular targets for malignant melanoma with gastric cancer.

Lower expression of KAI1 as a biomarker of poor survival prognosis of melanoma combined with colorectal cancer metastasis.

OBJECTIVE: This study aimed to investigate the correlation between KAI1 (CD82) and miR-633 expression and prognosis and survival time of patients with melanoma combined with colorectal cancer (CRC). METHODS: Clinical and follow-up data of melanoma and CRC patients were recorded, and the expression levels of KAI1 and miR-633 were detected. Pearson chi-square tests and Spearman correlation coefficient were used to analyze the relationship between prognosis and related parameters in these patients. Cox proportional risk regression and receiver operating characteristic curve analyses were used. RESULTS: Overall, 195 patients were included. KAI1 and miR-633 expression levels were significantly correlated with the prognosis of patients with melanoma combined with CRC. Spearman correlation analysis showed that the expression levels of KAI1 and miR-633 were significantly correlated with the prognosis of patients. Multivariate Cox regression analysis suggested that low expression levels of KAI1 and high expression levels of miR-633 indicated shorter survival time for patients. CONCLUSIONS: KAI1 expression was significantly correlated with melanoma and CRC patient prognosis. When KAI1 expression levels were low, the patient survival time was poor.

CD82 and Gangliosides Tune CD81 Membrane Behavior.

Tetraspanins are a family of transmembrane proteins that form a network of protein-protein interactions within the plasma membrane. Within this network, tetraspanin are thought to control the lateral segregation of their partners at the plasma membrane through mechanisms involving specific lipids. Here, we used a single molecule tracking approach to study the membrane behavior of tetraspanins in mammary epithelial cells and demonstrate that despite a common overall behavior, each tetraspanin (CD9, CD81 and CD82) has a specific signature in terms of dynamics. Furthermore, we demonstrated that tetraspanin dynamics on the cell surface are dependent on gangliosides. More specifically, we found that CD82 expression increases the dynamics of CD81 and alters its localization at the plasma membrane, this has no effect on the behavior of CD9. Our results provide new information on the ability of CD82 and gangliosides to differentially modulate the dynamics and organization of tetraspanins at the plasma membrane and highlight that its lipid and protein composition is involved in the dynamical architecture of the tetraspanin web. We predict that CD82 may act as a regulator of the lateral segregation of specific tetraspanins at the plasma membrane while gangliosides could play a crucial role in establishing tetraspanin-enriched areas.

CD82 is a marker to isolate ß cell precursors from human iPS cells and plays a role for the maturation of ß cells.

Generation of pancreatic ß cells from pluripotent stem cells is a key technology to develop cell therapy for insulin-dependent diabetes and considerable efforts have been made to produce ß cells. However, due to multiple and lengthy differentiation steps, production of ß cells is often unstable. It is also desirable to eliminate undifferentiated cells to avoid potential risks of tumorigenesis. To isolate ß cell precursors from late stage pancreatic endocrine progenitor (EP) cells derived from iPS cells, we have identified CD82, a member of the tetraspanin family. CD82+ cells at the EP stage differentiated into endocrine cells more efficiently than CD82- EP stage cells. We also show that CD82+ cells in human islets secreted insulin more efficiently than CD82- cells. Furthermore, knockdown of CD82 expression by siRNA or inhibition of CD82 by monoclonal antibodies in NGN3+ cells suppressed the function of ß cells with glucose-stimulated insulin secretion, suggesting that CD82 plays a role in maturation of EP cells to ß cells.

Differential HLA Association of GAD65 and IA2 Autoantibodies in North Indian Type 1 Diabetes Patients.

The human leucocyte antigen (HLA) association with type 1 diabetes (T1D) is well known but there are limited studies investigating the association between ß-cell autoantibodies and HLA genes. We evaluated the prevalence of GAD65 and IA-2 autoantibodies (GADA and IA2A) in 252 T1D patients from North India and investigated the genetic association of GADA and IA2A with HLA class I and class II genes/haplotypes. GADA and IA2A were detected in 50.79% and 15.87% of T1D patients, respectively, while only 8.73% had both GADA and IA2A. HLA-DRB1∗03 was observed to be significantly higher in GADA+ T1D patients as compared to GADA- (91.41% vs. 66.13%, Bonferroni-corrected P (P c) = 1.11 × 10-5; OR = 5.45; 95% CI: 2.67-11.08). Similarly, HLA-DQB1∗02 was found to be significantly increased in GADA+ patients (94.53%, P c = 2.19 × 10-5; OR = 6.27; 95% CI: 2.7-14.49) as compared to GADA- (73.39%). The frequencies of HLA-DRB1∗04 and DQB1∗03 were increased in IA2A+ patients (45.0% and 52.5%, respectively) as compared to that in IA2A- (25.94% and 33.96%, respectively). Further, the frequency of DRB1∗03-DQB1∗02 haplotype was found to be significantly increased in GADA+ T1D patients as compared to GADA- (60.55% vs. 41.94%, P = 3.94 × 10-5; OR = 2.13; 95%CI = 1.49-3.03). Similarly, HLA-DRB1∗04-DQB1∗03 haplotype was found to be significantly increased in IA2A+ T1D patients compared to IA2A- patients (22.5% vs. 12.97%; P = 0.041; OR = 1.95; 95%CI = 1.08-3.52). None of the HLA class I genes (HLA-A, B, and Cw) was found to be associated with GADA or IA2A in people with T1D. Our findings suggest that HLA-DRB1∗03/DQB1∗02 and HLA-DRB1∗04/DQB1∗03 might play an important role in the development of GADA and IA2A, respectively.

Trophoblast-derived CXCL12 promotes CD56bright CD82- CD29+ NK cell enrichment in the decidua.

PROBLEM: Decidual natural killer (dNK) cells play key roles in maternal-fetal immune regulation, trophoblast invasion, and vascular remodeling, and most dNK cell populations are CD56bright CD16- NK cells. However, the enrichment and redistribution of dNK cells in the local decidua have not been clarified yet. METHOD OF STUDY: A total of 45 women with normal pregnancies and 8 unexplained recurrent spontaneous abortion (RSA) patients were included. We isolated primary human dNK (n = 53) and peripheral blood NK (pNK) cells (n = 5) from specimen and analyzed CD56, CD82, and CD29 by flow cytometry (FCM). We assessed their adhesion ability by cell counts of NK cells adhered to decidual stromal cells (DSCs) in a co-culture system. RESULTS: We found that RSA patients had more CD56dim dNK cells with lower CD82 and higher CD29 than women with normal pregnancies. There were negative correlations of CD82 to CD29 on CD56dim and CD56+ dNK cells. In normal pregnancies, dNK cells had lower CD82 and higher CD29 expression with a stronger adhesion ability than pNK cells. Blocking CD82 on dNK cells increased the adhesive ability and CD29 expression, while blocking CD29 decreased the adhesive ability. Co-culturing dNK cells with trophoblast cells decreased CD82 expression and increased the adhesive ability of dNK cells and the percentage of CD56bright NK cells, while blocking trophoblast-derived CXCL12 increased CD82 expression, decreased CD29 expression, and impaired the adhesive ability of NK cells. CONCLUSION: Trophoblast cells enhance the adhesive ability of NK cells to DSCs via the CXCL12/CD82/CD29 signaling pathway and contribute to CD56bright NK cell enrichment in the uterus.

Src/STAT3 signaling pathways are involved in KAI1-induced downregulation of VEGF-C expression in pancreatic cancer.

A previous study by our group demonstrated that overexpression of KAI1 was associated with lymphatic metastasis in pancreatic cancer. The present study further investigated the signaling pathways involved in KAI1­induced downregulation of vascular endothelial growth factor C (VEGF­C) and lymphatic metastasis in pancreatic cancer. Immunohistochemistry was performed to examine KAI1 and VEGF­C expression in 28 surgically resected pancreatic cancer tissues. MIA PaCa­2 and PCAN1 pancreatic cancer cell lines were transfected with KAI1 overexpression vector. VEGF­C expression as well as phosphorylation of Src and signal transducer and activator of transcription (STAT)3 were assessed by western blot analysis. Furthermore, the signal transduction inhibitors PP2 and AG490 were used to block the Src and STAT3 signaling pathways, respectively. KAI1 was negatively correlated with VEGF­C expression in pancreatic tumor samples. In MIA PaCa­2 cells, VEGF­C expression was more significantly inhibited by restoration of KAI1 than that in PCAN1 cells. In addition, Src and STAT3 phosphorylation was decreased by KAI1 in MIA PaCa­2 cells. Of note, pre­treatment with PP2 efficiently reversed the KAI1-induced enhancement of Src and STAT3 phosphorylation as well as VEGF­C expression. Pre­treatment with AG490 efficiently reversed the KAI1-induced enhancement of STAT3 phosphorylation and VEGF­C expression, but had no effect on the upregulation of Src phosphorylation. The present study identified the involvement of Src/STAT3 signaling pathways in KAI1­induced downregulation of VEGF­C expression and suggested the implication of these pathways in lymphatic metastasis of pancreatic cancer.

Fluorescent and chromogenic in situ hybridization of CEN17q as a potent useful diagnostic marker for Birt-Hogg-Dubé syndrome-associated chromophobe renal cell carcinomas.

Birt-Hogg-Dubé syndrome (BHD) is a familial disorder associated with a germline mutation of FLCN that is a tumor suppressor gene. Patients with BHD have high risks for developing multiple renal cell carcinomas (RCCs). The frequent histological types are hybrid oncocytic/chromophobe tumors (HOCTs) and chromophobe RCCs. The morphology of HOCTs could alert pathologists to the possibility of BHD. On the other hand, chromophobe RCCs occurring in BHD patients demonstrate positive immunostaining for cytokeratin-7, CD82, and Ksp-cadherin similar to their sporadic counterparts. Highly reliable markers for BHD-associated chromophobe RCCs have not been identified. In the present study, we analyzed the state of chromosome 17 in 18 renal tumors composed of 8 chromophobe RCCs, 7 HOCTs, and 3 papillary RCCs obtained from BHD patients using fluorescent and chromogenic in situ hybridization probes for the centromeric region of chromosome 17 long arm. All chromophobe RCCs and HOCTs were disomic except for 1 chromophobe RCC that showed monosomy. On the other hand, 12 of 14 sporadic chromophobe RCCs were monosomic (P = .0008). The state of chromosomes 2 and 6 were also statistically different (P = .0074 and P = .0007, respectively). Three BHD-associated papillary RCCs demonstrated either trisomy (n = 2) or disomy (n = 1). Three of 5 sporadic papillary RCCs showed trisomy. The results indicate that fluorescent and chromogenic in situ hybridization of the centromeric region of chromosome 17 long arm should be a potent useful marker for chromophobe RCCs in patients who have not been diagnosed with BHD and thereby help to determine whether the cases should be considered for genetic testing.

Evaluation of the correlation of KAI1/CD82, CD44, MMP7 and ß-catenin in the prediction of prognosis and metastasis in colorectal carcinoma.

BACKGROUND: To investigate the relationship of KAI1/CD82, CD44, matrix metalloproteinase 7 (MMP7) and ß-catenin, and examine its association with clinicopathological features, metastasis and prognosis in colorectal carcinoma (CRC). METHODS: Immunohistochemical (IHC) analysis was used to detect the expression of KAI1/CD82, CD44, MMP7 and ß-catenin in 174 archival surgical specimens of human CRC. Furthermore, clinicopathological features such as age, sex and so on were also collected retrospectively. RESULTS: CD44, MMP7 and ß-catenin expression was positively associated with distant metastasis, lymph node metastasis and tumor-node-metastasis (TNM) stage. However, decreased KAI1/CD82 expression correlated significantly with distant metastasis, lymph node metastasis and TNM stage. KAI1/CD82 expression showed a negative correlation with CD44, MMP7 and ß-catenin. Furthermore, ß-catenin expression showed a positive correlation with CD44 and MMP7. Multivariate logistic regression analysis showed that KAI1/CD82 and ß-catenin expression were significantly associated with lymph node metastasis and KAI1/CD82 was significantly associated with distant metastasis. Kaplan-Meier analysis revealed that CD44, MMP7 and ß-catenin expression was negatively correlated with overall survival (OS), while KAI1/CD82 expression was positively correlated with OS. Low KAI1/CD82 expression and high expression of CD44, MMP7 and ß-catenin was associated with a poor prognosis in CRC. Multivariate Cox regression analysis indicated that the expression of KAI1/CD82, MMP7 and ß-catenin were independent predictors of OS in CRC. CONCLUSION: The expression of KAI1/CD82, CD44, MMP7 and ß-catenin is related to tumor metastasis and prognosis in CRC. Combined detection of these factors may be of significant value in predicting the prognosis and metastasis in CRC patients.

The novel function of CD82 and its impact on BCL2L12 via AKT/STAT5 signal pathway in acute myelogenous leukemia cells.

The aim of this study was to explore the biological functions of a tetraspanin family protein CD82 expressed aberrantly in chemotherapy-resistant CD34(+)/CD38(-) acute myelogenous leukemia (AML) cells. Microarray analysis of patient-isolated CD34(+)/CD38(-) AML cells revealed that the levels of anti-apoptotic protein BCL2L12 were downregulated after CD82 depletion by specific short hairpin RNA (shRNA). Western blot analysis indicated that BCL2L12 was aberrantly expressed in patient-isolated AML cells and AML cell lines. Furthermore, CD82 blockade by a specific antibody downregulated BCL2L12 in parallel with dephosphorylation of signal transducer and activator of transcription 5 (STAT5) and AKT, whereas pharmacological inhibition of STAT5 and AKT activation decreased BCL2L12 expression in leukemia cells. In addition, shRNA-mediated downregulation of BCL2L12 increased the levels of cleaved caspase-3 and suppressed proliferation of leukemia cells, impairing their engraftment in immunodeficient mice. Taken together, our results indicate that CD82 regulated BCL2L12 expression via STAT5A and AKT signaling and stimulated proliferation and engrafting of leukemia cells, suggesting that CD82 and BCL2L12 may be promising therapeutic targets in AML.

Differential expression patterns of metastasis suppressor proteins in basal cell carcinoma.

BACKGROUND: Basal cell carcinomas (BCCs) are common malignant skin tumors. Despite having a significant invasion capacity, they metastasize only rarely. Our aim in this study was to detect the expression patterns of the NM23-H1, NDRG1, E-cadherin, RHOGDI2, CD82/KAI1, MKK4, and AKAP12 metastasis suppressor proteins in BCCs. METHODS: A total of 96 BCC and 10 normal skin samples were included for the immunohistochemical study. Eleven frozen BCC samples were also studied by quantitative real time polymerase chain reaction (qRT-PCR) to detect the gene expression profile. RESULTS: NM23-H1 was strongly and diffusely expressed in all types of BCC. Significant cytoplasmic expression of NDRG1 and E-cadherin was also detected. However, AKAP12 and CD82/KAI1 expression was significantly decreased. The expressions of the other proteins were somewhere between the two extremes. Similarly, qRT-PCR analysis showed down-regulation of AKAP12 and up-regulation of NM23-H1 and NDRG1 in BCC. Morphologically aggressive BCCs showed significantly higher cytoplasmic NDRG1 expression scores and lower CD82/KAI1 scores than non-aggressive BCCs. CONCLUSION: The relatively preserved levels of NM23-H1, NDRG1, and E-cadherin proteins may have a positive effect on the non-metastasizing features of these tumors.

KAI1/CD82 and cyclin D1 as biomarkers of invasion, metastasis and prognosis of laryngeal squamous cell carcinoma.

OBJECTIVE: This study aimed to investigate the expressions and significance of KAI1/CD82 and cyclin D1 in laryngeal squamous cell carcinoma (LSCC). METHODS: Real-time quantitative PCR (Q-PCR) and Western blot assay were employed to detect the expressions of KAI1/CD82 and cyclin D1 in the laryngeal tissues of 86 LSCC patients, 32 patients with laryngeal polyp and 38 patients with laryngeal leukoplakia, and the influence of both proteins on the clinicopathological features and survival of LSCC patients. RESULTS: The changes in mRNA and protein expressions of KAI1/CD82 and cyclin D1 were consistent in three groups, and the expressions of KAI1/CD82 and cyclin D1 were significantly different among three groups (P<0.01 or <0.05). The KAI1/CD82 expression in patients with TNM stage III-IV LSCC, poorly differentiated LSCC, clinical stage III-IV LSCC or lymph node metastasis was markedly lower than that in those with TNM stage I-II LSCC, well differentiated LSCC, clinical stage I-II LSCC or no lymph node metastasis (P<0.01 or <0.05). However, there was no marked difference in KAI1/CD82 expression between males and females and among patients in different age groups (P>0.05). In LSCC patients positive for KAI1/CD82 protein expression, the median survival time was 76 months, which was significantly longer than that in LSCC patients negative for KAI1/CD82 protein expression (48 months; X(2)=16.293, P=0.000). The Cyclin D1 expression in patients with TNM stage III-IV LSCC, poorly differentiated LSCC, or clinical stage III-IV LSCC was dramatically higher than that in patients with TNM stage I-II LSCC, well differentiated LSCC, or clinical stage I-II LSCC (P<0.01 or <0.05). However, no marked difference was noted in cyclin D1 expression between males and females, among patients in different age groups and between patients with and without lymph node metastasis (P>0.05). In LSCC patients positive for cyclin D1 protein expression, the median survival time was 40 months, which was markedly shorter than that in LSCC patients negative for cyclin D1 protein expression (X(2)=9.517, P=0.02). In LSCC patients, there was a negative correlation between KAI1/CD82 expression and cyclin D1 expression (X(2)=7.86, P<0.01). CONCLUSION: KAI1/CD82 affects cell cycle. Both KAI1/CD82 and cyclin D1 are involved in the occurrence and development of LSCC, and may provide clinical information for evaluation of invasiveness, metastasis and prognosis of LSCC. Thus, KAI1/CD82 and cyclin D1 may serve as markers for determination of invasiveness, metastasis and prognosis of LSCC.

Deteccion y características de células prostáticas circulantes primarias, asociación con la presencia de micrometástasis y las implicaciones para el tratamiento quirúrgico en hombres con cáncer prostático. El estudio ProTECT (Prostate Tumor Early Cancer Test) / Detection and characteristics of primary circulating prostate cells; association with micrometastasis and implications for surgical treatment of men with prostate cáncer

OBJETIVO: Determinar la frecuencia de células prostáticas circulantes (CPCs) primaria en hombres con cáncer de próstata en el momento del diagnóstico, la asociación con micrometástasis ósea y subclasificación por CD82. Determinar la relación con la estadio patológica y la eficacia para seleccionar pacientes para la prostatectomía radical.MÉTODOS: Se incluyeron hombres con diagnóstico de cáncer de próstata previo a tratamiento definitivo. Se obtuvieron muestras de sangre y de médula ósea, las células mononucleares separadas por centrifugación diferencial y células prostáticas identificadas con inmumocitoquímica con anti-APE, las muestras positivas fueron sub-clasificadas con anti-CD82. Se registraron también los detalles de APE sérico, Índice de Gleason y estadio patológica.RESULTADOS: De 77 hombres, 58 (75,3%) tuvieron 1° CPCs detectadas. Hubo una asociación con estadio pero no con el Índice de Gleason, 31 (40,3%) tuvieron micrometástasis. Hubo una asociación significativa con la estadio patológica y Índice de Gleason. Pacientes CPC negativa tuvieron una menor frecuencia de micrometástasis que los hombres CPC positiva 1/19 versus 30/58 (p<0,0003).Hubo una relación inversa significativa entre la expresión de CD82 en CPCs y el índice de Gleason y menor frecuencia de micrometástasis en comparación con hombres CPC CD82 positivos (p<0,0005).En el grupo de combinación de hombres CPC negativa y CPC positiva CD82 positivo la frecuencia de micrometastasis fue significativamente menor que el grupo CPC (+) CD82 (-) 5/39 versus 26/38 respectivamente(p<0,0000007), con una sensibilidad de 87% y especificidad de 73,9% para la ausencia de micrometástasis(AU)

CONCLUSIONES: La presencia de CPCs implica un riesgo mayor de desarrollar micrometástasis, la co-expresión del CD82 es asociada con tumores de bajo grado, un riesgo disminuido del desarrollo de micrometástasis óseas. Como consecuencia, el uso de la detección de CPCs primarias y su sub-clasificación podrían ser clínicamente útiles para identificar los pacientes los cuales beneficiarán de una prostatectomía radical como tratamiento de primera línea(AU)

OBJECTIVES: To determine the frequency of primary circulating prostate cells in men with prostate cancer at the time of diagnosis, the association with micrometastasis, sub-classification for CD82 and the relation with pathological stage. To determine their clinical usefulness to identify patients in whom radical prostatectomy would be first choice therapy.METHODS: Men with the diagnosis of prostate cancer before definitive therapy. Blood and bone marrow samples were taken, mononuclear cells separated by differential centrifugation and prostate cells identified with immunocytochemistry using anti-PSA. Positive samples were sub-classified with anti-CD82. Details of serum PSA, Gleason score and pathological stage were registered.RESULTS: Of 77 men 58 (75.3%) had primary CPCs detected, there was an association with stage but not Gleason. 31 (40.3%) had micrometastasis with an association with stage and Gleason score. CPC-negative patients had fewer micrometastasis detected, 1/19 versus 30/58 (p<0.003).There was an inverse relation between CD82 expression and Gleason score, men with CPCs expressing CD82 had fewer micrometastasis. The combined group of CPC negative and CPC positive CD82 positive men showed a sensitivity of 87% and specificity of 73.9% for the absence of micrometastasis.CONCLUSIONS: The detection of CPCs and sub-classification with CD82 could be clinically useful to identify men with a significantly lower risk of micrometastais and as a consequence to identify men in whom radical prostatectomy could be the best initial treatment(AU)

Gene expression profiling of chromophobe renal cell carcinomas and renal oncocytomas by Affymetrix GeneChip using pooled and individual tumours.

Due to overlapping morphology, malignant chromophobe renal cell carcinomas (RCC) and benign renal oncocytomas (RO) may pose a diagnostic problem. In the present study, we have applied different algorithms to evaluate the data sets obtained by hybridisation of pooled and also individual samples of renal cell tumours (RCT) onto two different gene expression platforms. The two approaches revealed high similarities in the gene expression profiles of chromophobe RCCs and ROs but also some differences. After identifying the differentially expressed genes by statistic analyses, the candidate genes were further selected by a real time and normal RT-PCR and their products were analysed by immunohistochemistry. We have identified CD82 and S100A1 as valuable markers for chromophobe RCC as well as AQP6 for ROs. However, these genes are expressed at the protein level in other types of RCTs as well albeit at a low frequency and low intensity. As none of the selected genes marks exclusively one type of RCTs, for the differential diagnosis of chromophobe RCCs and ROs, a set of markers such as CD82, S100A1 and AQP6 as well as some others would be an option in routine histological laboratories.

Expression and clinical significance of p53, JunB and KAI1/CD82 in human hepatocellular carcinoma.

BACKGROUND: The mechanism of regulation of KAI1, a specific tumor metastasis suppression gene, is controversial. A recent study showed that the synergism of wild-type p53 and JunB has the function of regulating the expression of KAI1, a metastasis inhibiting factor in prostate cancer cells. The wild-type p53 gene is an activator of apoptosis and is closely related to malignant tumor cell multiplication. JunB, a member of the fos/jun family, is a key component of activator protein transcription factor and a major target element in the transmission pathway of mitosis. This study aimed to evaluate the relationship between the expression of KAI1 and p53 combined with JunB in tumor tissues and clinical outcomes in hepatocellular carcinoma (HCC) patients. METHODS: Quantitative real-time RT-PCR, Western blotting techniques and immunohistochemistry were used to evaluate the expression of KAI1 mRNA, KAI1/CD82, p53 and JunB in HCC patients, and the relationship between their expression and the clinicopathological prognostic parameters was analyzed. RESULTS: In cancer tissues, the values for positive expression of KAI1 mRNA, KAI1/CD82, p53 and JunB were 31.25%, 26.25%, 48.75%, and 20.00%, respectively, while in adjacent non-tumor tissues, they were 100%, 94.74%, 2.63%, and 76.32%, respectively. There was no correlation between the expression levels of p53 or JunB and KAI1 mRNA or KAI1/CD82. However, there were significant correlations between the expression levels of p53 combined with JunB and not only KAI1 mRNA but also KAI1/CD82 proteins. CONCLUSIONS: When p53 dysfunction and low expression of JunB are simultaneous, they may play an important role in down-regulating the expression of KAI1 by synergism in HCC. But further studies in vivo and in vitro are needed to verify these results.

HIV-1 replication in dendritic cells occurs through a tetraspanin-containing compartment enriched in AP-3.

Dendritic cells (DC) are crucial components of the early events of HIV infection. Dendritic cells capture and internalize HIV at mucosal surfaces and efficiently transfer the virus to CD4+ T cells in trans through infectious synapses (trans-infection pathway). Alternatively, HIV-1 replicates in DC (R5-HIV-1) (cis-infection pathway). Here, we analyzed HIV trafficking in DC during the trans-infection pathway as well as the cis-infection pathway. Confocal immunofluorescence microscopy demonstrated that after capture by DC, R5-HIV-1 and HIV-1 pseudotyped with vesicular stomatitis virus protein G colocalized in a viral compartment enriched in tetraspanins including CD81, CD82 and CD9, although at different levels, indicating a role of the viral envelope in targeting to the tetraspanin-rich compartment. Replication of R5-HIV-1 in DC (cis-infection pathway) also led to the accumulation, in an envelope-independent manner, of mature viral particles in a tetraspanin-rich compartment. A fraction of the HIV-1-containing compartments appeared directly accessible from the cell surface. In sharp contrast with the trans-infection pathway, the delta-subunit of the adaptor protein 3 (AP-3) complex was enriched on the HIV-1-containing compartment during R5-HIV-1 replication in DC (cis-infection pathway). Downregulation of AP-3 delta-adaptin reduced significantly viral particle release from HIV-1-infected DC. Together, these studies demonstrate a role for AP-3 in HIV replication in a tetraspanin-rich compartment in DC and contribute to the elucidation of the trafficking pathways required for DC-T cell transfer of HIV-1 infection, a critical step during the early events of HIV infection.

Reduced protein expression of metastasis-related genes (nm23, KISS1, KAI1 and p53) in lymph node and liver metastases of gastric cancer.

PURPOSE: Metastasis remains an incurable common complication in patients with gastric cancer. A variety of theories have been proposed to explain the inefficiency of the metastatic process. To compare protein expression of metastasis-related genes (nm23, KISS1, KAI1 and p53) between primary tumours and metastatic tumours may be useful in illustrating these theories. METHODS: Metastasis-related tissue microarrays (including normal tissues, primary tumours, nodal metastases and liver metastases) were constructed. The protein expression of nm23, KISS1, KAI1 and p53 in lymph node and liver metastases from advanced gastric cancer specimens was mainly examined by immunohistochemical staining in relation to primary tumours. RESULTS: Immunohistochemical staining showed reduced protein expression of nm23, KISS1 and KAI1 in lymph node and liver metastases compared with primary tumours. Results for p53 were to the contrary. CONCLUSIONS: Our investigations revealed a tendency of reduced protein expression of metastasis suppressor genes nm23, KISS1 and KAI1 in gastric cancer with the progress of metastasis. This means that the progression theory is an important determinant of metastatic efficiency.

KAI-1 protein expression in odontogenic cysts.

The KAI-1 tumor suppressor gene is widely distributed in normal tissues and its down-regulation may be correlated with the invasive phenotype and metastases in several different epithelial tumors. The aim of the present study was an evaluation of KAI-1 expression in radicular cysts (RC), follicular cysts (FC), orthokeratinized keratocysts (OOKC), and parakeratinized keratocysts (POKC). Eighty-five odontogenic cysts, 28 RC, 22 FC, and 35 OKC (16 OOKC, 19 POKC) were selected. All the POKC were negative and only four of 16 of the OOKC were positive for KAI-1. On the contrary, all RC and FC cases were positive and immunoreactivity for KAI-1 was detected throughout all the layers of the cyst epithelium. The lack of KAI-1 expression in POKC could help to explain the differences in the clinical and pathologic behavior of OKC and, according to what has been reported for epithelial tumors, could be related to the increased aggressive behavior and invasiveness of OKC.

Characterization of an antibody that can detect the Kai1/CD82 murine metastasis suppressor.

BACKGROUND: Kai1, also known as CD82, is a member of the tetraspanin family (TM4SF). The human homolog, KAI1, is an activation antigen of T-cells and is a metastasis suppressor for prostate and other cancers. Little is known about the mouse protein because of the lack of antibody reagents. METHODS: Peptide immunized rabbits were used to generate polyclonal antibody to Kai1. The antibody was analyzed using immunoblotting, flow cytometry, and immunohistochemistry. RESULTS: This antibody specifically recognizes murine Kai1 protein, crossreacts with rat Kai1 but not with human KAI1. The normal tissue distribution of this protein in mice is shown to be similar to that of the human homolog. Interestingly, mouse prostatic epithelium showed differential expression within the lobes. CONCLUSION: This antibody, the first described that can specifically detect murine Kai1/CD82, should be very useful in addressing the mechanism of action of Kai1 in metastatic suppression.