SUMO-specific protease 6 promotes gastric cancer cell growth via deSUMOylation of FoxM1.

SUMOylation is a post-translational modification exerted various effects on the target proteins. SUMOylation is a highly dynamic and reversible process, which has been shown to play an important role in tumorigenesis. However, the roles of sentrin/SUMO-specific proteases (SENPs), which mediate the reverse process of SUMOylation, in tumorigenesis remains largely unexplored. Here, we uncover a critical role of SENP6 in promoting gastric cancer cells growth via regulating the deSUMOylation of a transcription factor forkhead box protein M1 (FoxM1). We demonstrated that the mRNA and protein levels were elevated in gastric cancer tissues. Overexpression of SENP6 promoted, while RNA interference depletion of endogenous SENP6 inhibited gastric cancer cells growth and the ability of colony formation. By using biochemical assays, we identified FoxM1 as a novel substrate of SENP6 in gastric cancer cells. Thus, our data suggest that SENP6, which is highly expressed in gastric cancer cells, regulates the transcriptional activity and stability of FoxM1 through deSUMOylation.

MicroRNA-501 promotes HBV replication by targeting HBXIP.

MicroRNAs (miRNAs) can negatively regulate gene expression and also induce or inhibit viral replication. In the present study, we found 10 miRNAs were differentially expressed in a stable HBV-producing cell line (HepG2.2.15) compared with its control cell line (HepG2) by miRNA array analysis. miR-501 was significantly up-regulated in HepG2 cells and tissues with high-HBV replication. miR-501 expression was significantly up-regulated in hepatocellular carcinoma tissues, where HBV replication kept high. Down-regulating miR-501 could significantly inhibit HBV replication, but not influence the growth of HepG2.2.15 cells. Luciferase reporter and western blot assays revealed that HBXIP, an inhibitor of HBV replication, was a potential target of miR-501. Moreover, knockdown of HBXIP rescued the inhibition of HBV that occurred after the loss of miR-501 in HepG2.2.15 cells, suggesting that miR-501 induced HBV replication partially by targeting HBXIP. Thus, knockdown of miR-501 might provide a new mechanism and therapeutic target for inhibiting HBV replication.

Mass-forming immunoglobulin G4-related cholangitis with atypical pancreatic lesions: a case report of difficult diagnosis.

BACKGROUND: Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a systemic immune-mediated fibroinflammatory disease that results in the tissue destruction of multiple organs. IgG4-RD is often underdiagnosed or misdiagnosed as malignant, infectious, or other inflammatory disorder. CASE PRESENTATION: We describe a 56-year-old woman presented with jaundice and weight loss. Radiological imaging showed common hepatic duct wall thickening and nodular lesions in the pancreas, which was highly suspicious of malignancy. However, she was contraindicated for biopsy; hence, the diagnosis of IgG4-RD was made based on her high serum IgG4 level, multiorgan involvement, and steroid response. The effect of steroid therapy was significant, although the disease relapsed during the maintenance treatment. The dosage of steroid was re-increased, and the patient was under close follow-up. CONCLUSIONS: The diagnosis of IgG4-RD is challenging due to its diverse manifestations. Therefore, a careful systematic assessment is necessary to improve the accuracy of IgG4-RD diagnosis, and a close follow-up is important to monitor the disease development as well as adjust the treatment strategy accordingly.

Case report: Coexistence of sigmoid tumor with unusual pathological features and multiple colorectal neuroendocrine tumors with lymph node metastases.

The coexistence of adenocarcinoma and neuroendocrine neoplasm (NEN) in the same tumor is rare. What is rarer is that the neuroendocrine component is a well-differentiated neuroendocrine tumor (NET) Grade (G) 1. Most colorectal NETs are single, but multiple neuroendocrine tumors (M-NETs) are rare. Well-differentiated NETs rarely metastasize. Here, we present a unique case of a synchronous sigmoid tumor and multiple colorectal NETs with lymph node metastases. The sigmoid tumor consisted of adenocarcinoma and NET G1. The metastatic component was NET G1. A 64-year-old man underwent a colonoscopy for persistent changes in bowel habits and positive fecal occult blood for 1 year. An ulcerative lesion, which was diagnosed as colon cancer, was seen in the sigmoid colon. In addition, scattered lesions could be seen in the colon and rectum. Surgical resection was performed. Pathological findings suggested that the ulcerative lesion was composed of 80% adenocarcinoma and 20% neuroendocrine component (NET G1), while the remaining lesions were consistent with NET G1. At the same time, 11 lymph nodes around the resected intestinal segment were invaded by NET G1. The prognosis of the patient was good. After 13 months of follow-up, no recurrence and no metastasis were found. We hope to provide a reference and improve our understanding of the clinicopathological features and biological behavior of these unique tumors. We also aim to emphasize the importance of radical surgery and individualized treatment.

High-grade B-cell lymphoma with gastroduodenal involvement showing paraneoplastic cerebellar degeneration: a case report.

Background: Paraneoplastic cerebellar degeneration (PCD), which displays ataxia and other cerebellar symptoms, is the most common paraneoplastic neurological syndrome (PNS). PCD is more likely to occur in individuals with small cell lung cancer (SCLC), gynecological malignancies, and Hodgkin disease, but it is rarely associated with non-Hodgkin lymphoma (NHL). Case Description: We report a case of PCD accompanying high-grade B-cell lymphoma embedded in an individual's stomach and duodenum, who also presented with acute onset of gait ataxia and slurred speech. The results of the common laboratory tests for neurological disorders, including the paraneoplastic antibody test, were negative. The key to the accurate diagnosis was the positron emission tomography/computed tomography findings. The final diagnosis of high-grade B-cell lymphoma was unclear until the performance of repeated esophagogastroscopy with multipoint deep excavation biopsies. After standard chemotherapy, the patient's gastric tumor was significantly alleviated and cerebellar syndrome was significantly improved. Conclusions: This case highlights the challenges of diagnosing PNS associated with occult malignancy. PNS patients may present with a variety of neurological disorders; Thus, if any unexplained neurological symptoms appear after a series of specific laboratory and imaging tests, a diagnosis of PNS should be taken into consideration in the differential diagnosis list, as it may help clinicians identify asymptomatic malignancies and ensure patients receive correct treatments in a timely manner. A high-quality endoscopic biopsy is essential, as it helps hematologists make an accurate diagnosis of lymphoma with gastroduodenal involvement based on pathology.

URG11 promotes gastric cancer growth and invasion by activation of beta-catenin signalling pathway.

Upregulated gene 11 (URG11), a new gene upregulated by Hepatitis B Virus X protein (HBx), was previously shown to activate beta-catenin and promote hepatocellular growth and tumourigenesis. Although the oncogenic role of URG11 in the development of hepatocellular carcinoma has been well documented, its relevance to other human malignancies and the underlying molecular mechanisms remain largely unknown. Here we reported a novel function of URG11 to promote gastric cancer growth and metastasis. URG11 was found to be highly expressed in gastric cancer tissues compared with adjacent nontumourous ones by immunohistochemical staining and western blot. Knockdown of URG11 expression by small interfering RNA (siRNA) effectively attenuated the proliferation, anchorage-independent growth, invasiveness and metastatic potential of gastric cancer cells. URG11 inhibition led to decreased expression of beta-catenin and its nuclear accumulation in gastric cancer cells and extensive costaining between URG11 and beta-catenin was observed in gastric cancer tissues. Transient transfection assays with the beta-catenin promoter showed that it was inhibited by URG11-specific small inhibitory RNA. Moreover, suppression of endogenous URG11 expression results in decreased activation of beta-catenin/TCF and its downstream effector genes, cyclinD1 and membrane type 1 matrix metallopeptidase (MT1-MMP), which are known to be involved in cell proliferation and invasion, respectively. Taken together, our data suggest that URG11 contributes to gastric cancer growth and metastasis at least partially through activation of beta-catenin signalling pathway. These findings also propose a promising target for gene therapy in gastric cancer.

Ribosomal protein L6 promotes growth and cell cycle progression through upregulating cyclin E in gastric cancer cells.

Our previous study revealed that human ribosomal protein L6 (RPL6) was upregulated in multidrug-resistant gastric cancer cells and over-expression of RPL6 could protect gastric cancer cells from drug-induced apoptosis. The present study was designed to explore the role of RPL6 in tumorigenesis and development of gastric cancer. The expression of RPL6 in gastric cancer tissues and normal gastric mucosa was evaluated by immunohistochemical staining. It was found RPL6 was expressed at a higher level in gastric cancer tissues than that in normal gastric mucosa. RPL6 was then genetically overexpressed or knocked down in human immortalized gastric mucosa epithelial GES cells. It was demonstrated that upregulation of RPL6 accelerated the growth and enhanced in vitro colony forming ability of GES cells whereas downregulation of RPL6 showed adverse effects. Moreover, over-expression of RPL6 could promote G1 to S phase transition of GES cells. It was further evidenced that upregulation of RPL6 resulted in elevated cyclin E expression while downregulation of RPL6 caused decreased cyclin E expression in GES cells. Taken together, these data indicated that RPL6 was overexpressed in human gastric cancer and its over-expression could promote cell growth and cell cycle progression at least through upregulating cyclin E expression.

Potent cell growth inhibitory effects in hepatitis B virus X protein positive hepatocellular carcinoma cells by the selective cyclooxygenase-2 inhibitor celecoxib.

Hepatitis B virus (HBV) X protein (HBx) and cyclooxygenase-2 (COX-2) are all playing roles in hepatocellular carcinoma (HCC), but the reversing effects of COX-2 inhibitors on the neoplastic features caused by HBx protein is still unclear. To further evaluate the therapeutic potential of celecoxib on HBx mediated transformation, HCC cells transfected with HBx gene were treated with COX-2 selective inhibitor, celecoxib. The amount the main metabolite of COX-2, prostaglandin E2 (PGE2), was determined by using high sensitivity ELISA. Electron microscope and flow cytometry was used to analyze cell apoptosis and cell cycle distribution. RT-PCR and Western blot were used to identify the molecules involved in celecoxib induced cell apoptosis. The results showed that celecoxib inhibited cell growth more significantly and also induced more cell apoptosis in HBx over-expression cells than in control cells. Celecoxib could selectively inhibited COX-2 expression and PGE2 production. Celecoxib also inhibited p(473Ser)Akt, raf and p53 expression, and induced apoptosis by release of cytochrome c and activation of caspase 9, 3, and 6, which were more remarkably in HBx positive cells than in control cells. These results suggest that celecoxib had potent cell growth inhibitory effects on HBx positive HCC cells mainly through inducing more cell apoptosis, and these findings provide a new insight into the anticancer effects of celecoxib against HBx related HCC.

p75 neurotrophin receptor inhibits invasion and metastasis of gastric cancer.

The p75 neurotrophin receptor (p75NTR) is a focus for study at present. However, its function in gastric cancer was not elucidated. Here, we investigated its relation with metastasis of gastric cancer. By immunohistochemistry, we found that the positive rate of p75NTR expression in metastatic gastric cancer was 15.09% (16 of 106), which was lower compared with nonmetastatic gastric cancer (64.15%; 68 of 106). The average staining score in nonmetastatic gastric cancer was significantly higher than in metastatic gastric cancer (1.21 +/- 0.35 versus 0.23 +/- 0.18; P<0.01). p75NTR protein level was also lowly expressed in the highly liver-metastatic gastric cancer cell line XGC9811-L compared with other gastric cancer cell lines by Western blotting. It could also significantly inhibit the in vitro adhesive, invasive, and migratory and in vivo metastatic abilities of gastric cancer cell lines SGC7901 and MKN45 by reducing urokinase-type plasminogen activator (uPA) and matrix metalloproteinase (MMP)-9 proteins and by increasing tissue inhibitor of matrix metalloproteinase (TIMP)-1 protein. Further studies showed that p75NTR could suppress the nuclear factor-kappaB (NF-kappaB) signal. SN50, a specific inhibitor of NF-kappaB, which could inhibit in vitro invasive and migratory abilities of gastric cancer cells, reduced expression of uPA and MMP9 proteins and increased expression of TIMP1 protein. Taken together, p75NTR had the function of inhibiting the invasive and metastatic abilities of gastric cancer cells, which was mediated, at least partially, by down-regulation of uPA and MMP9 proteins and up-regulation of TIMP1 protein via the NF-kappaB signal transduction pathway. Our studies suggested that p75NTR may be used as a new potential therapeutic target in metastatic gastric cancer.

[Expression and significance of glypican-3 in colorectal cancer].

OBJECTIVE: To investigate the expression and significance of Glypican-3 in colorectal cancer. METHODS: Immunohistochemistry was used to detect the expression of Glypican-3 in 200 specimens of colorectal cancer and adjacent non-cancerous tissues resected during operation. RESULTS: Glypican-3 immunoreactivity was recognized in both the cytoplasm and cellular membrane. The Glypican-3 positive expression rate in the tumor samples was 66.0% (132/200), significantly higher than that in the adjacent nontumor tissues (24%, 48/200, P = 0.019). The Glypican-3 expression rate was significantly correlated with the carcinoma invasion (P = 0.023) and lymph node metastasis (P = 0.015), but not associated with gender, age, tumor size, and differentiation grade (all P > 0.05). CONCLUSION: Over-expression of Glypican-3 may play an important role in the genesis and development of colorectal cancer, and may be used as a new biological parameter in predicting invasion and metastasis of colorectal carcinoma.

MicroRNA-155-enhanced autophagy in human gastric epithelial cell in response to Helicobacter pylori.

BACKGROUND/AIM: MicroRNAs (miRNAs) are a class of small noncoding RNAs acting as posttranscriptional gene expression regulators in many physiological and pathological conditions. MiR-155 is one kind of miRNAs that plays an important role in causing various diseases. However, the precise molecular mechanism of the ectopic expression of miR-155 in Helicobacter pylori infection remains poorly understood. Autophagy has recently been identified as an effective way to control the intracellular bacterium survival. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-H. pylori response. PATIENTS AND METHODS: Totally 86 H. pylori-positive patients together with 10 H. pylori-negative, healthy control subjects were included in the study. Correlation between immunohistochemical grades and miR-155 expression were determined. Molecular mechanism of miR-155 on regulation of autophagy and elimination of intracellular H. pylori were determined using the GES-1 cell model. RESULTS: We found that overexpression of miR-155 by transfecting miR-155 mimics could significantly decrease the survival of intracellular H. pylori, and this process was through induction of autophagy. Furthermore, there was a significant correlation between miR-155 and immunohistochemical grades in H. pylori-positive patients, and miR-155 expression were decreased in the intestinal metaplasia group. CONCLUSIONS: The results have indicated that the miR-155 expression level plays a key role in immunity response against H. pylori and this might provide potential targets for the future treatment of H. pylori-related diseases.

MiR-199a regulates cell proliferation and survival by targeting FZD7.

A growing amount of evidence indicates that miRNAs are important regulators of multiple cellular processes and, when expressed aberrantly in different types of cancer such as hepatocellular carcinoma (HCC), play significant roles in tumorigenesis and progression. Aberrant expression of miR-199a-5p (also called miR-199a) was found to contribute to carcinogenesis in different types of cancer, including HCC. However, the precise molecular mechanism is not yet fully understood. The present study showed that miR-199a is frequently down-regulated in HCC tissues and cells. Importantly, lower expression of miR-199a was significantly correlated with the malignant potential and poor prognosis of HCC, and restoration of miR-199a in HCC cells led to inhibition of the cell proliferation and cell cycle in vitro and in vivo. Furthermore, Frizzled type 7 receptor (FZD7), the most important Wnt receptor involved in cancer development and progression, was identified as a functional target of miR-199a. In addition, these findings were further strengthened by results showing that expression of FZD7 was inversely correlated with miR-199a in both HCC tissues and cells and that over-expression of miR-199a could significantly down-regulate the expression of genes downstream of FZD7, including ß-catenin, Jun, Cyclin D1 and Myc. In conclusion, these findings not only help us to better elucidate the molecular mechanisms of hepatocarcinogenesis from a fresh perspective but also provide a new theoretical basis to further investigate miR-199a as a potential biomarker and a promising approach for HCC treatment.

Optimal caliper width for propensity score matching of three treatment groups: a Monte Carlo study.

Propensity score matching is a method to reduce bias in non-randomized and observational studies. Propensity score matching is mainly applied to two treatment groups rather than multiple treatment groups, because some key issues affecting its application to multiple treatment groups remain unsolved, such as the matching distance, the assessment of balance in baseline variables, and the choice of optimal caliper width. The primary objective of this study was to compare propensity score matching methods using different calipers and to choose the optimal caliper width for use with three treatment groups. The authors used caliper widths from 0.1 to 0.8 of the pooled standard deviation of the logit of the propensity score, in increments of 0.1. The balance in baseline variables was assessed by standardized difference. The matching ratio, relative bias, and mean squared error (MSE) of the estimate between groups in different propensity score-matched samples were also reported. The results of Monte Carlo simulations indicate that matching using a caliper width of 0.2 of the pooled standard deviation of the logit of the propensity score affords superior performance in the estimation of treatment effects. This study provides practical solutions for the application of propensity score matching of three treatment groups.

The expression of hypoxia-inducible factor-1alpha in hepatitis B virus-related hepatocellular carcinoma: correlation with patients' prognosis and hepatitis B virus X protein.

Hypoxia inducible factor-1alpha (HIF-1alpha) was well correlated with carcinogenesis and tumor progression in many kinds of cancer. In this study, high expression of HIF-1alpha was found in 37 of the 72 (51.39%) tumor specimens, and significantly correlated with venous invasion and lymphonode invasion. Patients with high expression of HIF-1alpha had a significantly shorter overall survival rate and disease-free survival rate than those with low expression. Multivariate analysis showed high HIF-1alpha expression was a borderline independent factor of overall survival. HIF-1alpha expression was also found to be significantly correlated with the expression of hepatitis B virus X protein (HBx), and over-expressed HBx upregulated HIF-1alpha protein expression in vitro. These results suggested that HIF-1alpha, which was partially regulated by HBx, might be a prognostic marker of HBV-related HCC patients.

Expression of Jagged1 and its association with hepatitis B virus X protein in hepatocellular carcinoma.

Jagged1 is one of the ligands of Notch signaling pathway, which controls cellular proliferation and differentiation, and also plays important roles in various malignant tumors. However, the expression of Jagged1 in hepatocellular carcinoma (HCC) has not been elucidated, nor whether it is associated with hepatitis B virus X protein (HBx). In this study, we found that Jagged1 was highly expressed in 79.2% (42/53) of HCC tissues compared with adjacent nontumor liver (P <0.05), and its expression was found to be closely related with HBx (rs=0.522, P <0.001) in HCC tissues. Our in vitro study also showed that alteration of HBx expression in HCC cell lines led to a consistent change of Jagged1. Moreover, Jagged1 was found to co-localize and directly interact with HBx in HCC tissues and HBx expressed HCC cell lines. Our results reveal that Jagged1, which is regulated by HBx, may contribute to the development of HCC.

Preparation and characterization of a specific monoclonal antibody against a new gene product: URG11.

As a new gene, the monoclonal antibody against URG11 protein is not currently available. In this study, one monoclonal antibody (MAb) against URG11 was obtained with standard cell fusion technique and enzymelinked immunosorbent assay (ELISA) screening. The peptide of URG11 used in making the MAb in this study was synthesized as described. One of the newly developed MAbs is named MAb 3D2, the isotype of which is IgG2a. Immunohistochemistry and Western blot showed that MAb 3D2 could recognize URG11 protein in both native and denatured forms. MAb 3D2 will be a useful tool for the functional research of URG11 in future studies.

[Construction of eukaryotic expression vector of siRNA specific for MAD2 and its effect on the growth of gastric cell line SGC7901].

AIM: To construct the RNA interference eukaryotic expression vector specific for human MAD2 gene and to observe its effect on the growth of gastric cancer cell line SGC7901. METHODS: The expression vectors of pSilencer3.1/MAD2-siRNA1 and pSilencer3.1/MAD2-siRNA2 were constructed by gene recombination and then were stably transfected into the gastric carcinoma cell line SGC7901 by liposome mediation. The expression of MAD2 on the levels of protein and mRNA was detected by Western blot and RT-PCR, and the monoclone with the highest inhibition efficiency was selected. The growth of the transfected cells was assessed by MTT. And the cells treated with 1.0 mg/L vincristine (VCR) for 24 h were analyzed by FCM for cell cycle. RESULTS: Sequence-specific siRNAs targeting MAD2 significantly down regulated the expression of MAD2 in SGC7901 cells. In MAD2-siRNA transfected cells, the rate of cell growth increased markedly and cell cycle couldn't be arrested in M phase induced by VCR, while the cells transfected with the mock vector could. CONCLUSION: Down regulation of MAD2 expression of SGC7901 bv sequence-specific siRNA could accelerate the cell growth and impair the mitosis arrest of SGC7901 induced by VCR.

Enhanced cell survival of gastric cancer cells by a novel gene URG4.

Upregulated gene 4 (URG4), a novel gene located on 7 chromosome (7p13), was found to contribute to hepatocarcinogenesis. However, the role of URG4 in the gastric carcinogenesis still remains unclear. In the present study, URG4 was found by immunohistochemistry to be upregulated in human gastric cancer tissues compared with matched adjacent nonneoplastic tissues. The proliferating cell nuclear antigen index is higher in gastric cancer tissues with high URG4 expression than in those with low URG4 expression. The growth of GES-1 cells, which are immortalized human gastric epithelial mucosa cells with baseline URG4 expression, was accelerated by URG4 induction. Downregulation of URG4 through URG4 small interfering RNA (siRNA) in SGC7901 and MKN28 cells, which had high endogenous URG4 expression, suppressed cell proliferation in both of these cells. URG4-siRNA also inhibited the proliferation of SGC7901 and MKN28 cells in soft agar and tumor formation in nude mice. Overexpression of URG4 in GES cells upregulated cyclin D1, whereas repression of URG4 in SGC7901 and MKN28 cells downregulated cyclin D1. The data suggested that URG4 played an important role in the development of human gastric cancer by regulating the expression of cyclin D1 and might be used as a potential therapeutic target for gastric cancer.

[Modulation of the rate of CD158a+/b+ cells by Th1-and Th2-like cytokines].

AIM: To explore modulation of CD158+ cells in human peripheral blood by Th1-and Th2-like cytokines and provide basic data for inducing immune tolerance and preventing graft-versus-host disease (GVHD) in stem cells transplantation. METHODS: Peripheral blood mononuclear from healthy adults were cultured with Th1-like cytokines IL-2, IFN-gamma and Th2-like cytokines IL-4, IL-6 for 72 hours, rates of CD3+, CD4+, CD8+ cells, CD16+ CD56+ cells and CD158a+/b+ cells were analyzed by FACS. RESULTS: (1) The effects of cytokines on CD3+, CD4+, CD8+ and CD16+ CD56+ cells: the rates of above cells were greatly increased after being treated with IL-2 or IFN-gamma(P< 0.05), but efficacy of IL-2 was higher than that of IFN-gamma(P< 0.05). The rates of above cells in IL-2+IFN-gamma treated cells were higher than that in IL-2 or IFN-gamma treated alone. The rates of above cells were greatly decreased after being treated with IL-4+IL-6(P< 0.05), but efficacy of combination of IL-2+IL-4 was higher than that of IL-4 alone, lower than that of IL-2 alone (P< 0.05). (2) The effects of cytokines on CD158a+/b+ cells: the rates of CD158a+/b+ cells in total mononuclear and in CD3+, CD4+, CD8+ and CD16+ CD56+ cells were significantly raised after being treated with IL-2 (P< 0.01), but had no significance changes after being treated with IFN-gamma. The rates of CD158a+/b+ cells were decreased after being treated with IL-4+IL-6, whereas increased after being treated with IL-2+IFN-gamma(P< 0.05), but efficacy of being treated with IL-2+IL-4 was lower than that with IL-2(P< 0.05). CONCLUSION: IL-2 plays an important role in the regulation of CD158a/b expression or proliferation of CD158a+/b+ cells. It may involve in controlling NK cells and T cells activity via expression of regulating these molecules or stimulating proliferating of CD158a+/b+ cells. IL-4 and IL-6 have a slight ability to decrease the rates of CD158a+/b+ cells and IL-4 can partially reverse the effect of IL-2 on CD158a+/b+ cells.

[Effect of activation of cellular immunity on p58+ cells expressing killer-cell-inhibitory receptor cells].

UNLABELLED: The purpose of this study was to evaluate the effects of cellular immunity activation on P58(+) cells expressing killer cell inhibitory receptor (KIR) and their regulatory function on cellular immunity, and provid theoretical data for preventing graft-vers-host disease (GVHD) in stem cell transplantation therapy. The mononuclear cells from human peripheral blood were incubated with IL-2, Con A and Lipostin (LP) for 72 hours. The KIR expressing cells, P58.1(+) and P58.2(+) cells, were analyzed by flow cytometry. The results showed that the percentages of CD3(+), CD4(+), CD8(+), CD16(+)CD56(+), P58.1(+) and P58.2(+) cells were greatly increased after treated with IL-2, Con A and LP, separately or in combination, and the percentages of above cells in combined treatment groups were higher than those of single stimulated groups, especially the percentage of cells in the IL-2 + LP group was significantly higher than those in IL-2 and LP singly treated groups. IN CONCLUSION: IL-2, Con A and LP possess the ability to induce the expression of KIR and stimulate proliferation of P58.1(+) and P58.2(+) cells while to activate the celluar immunity response, the expression of P58 gene may be regulated by the activation of cellular immunity.