Morinda citrifolia (Noni) Juice Suppresses A549 Human Lung Cancer Cells via Inhibiting AKT/Nuclear Factor-κ B Signaling Pathway.

OBJECTIVE: To study the mechanism of the anti-tumor effect of Morinda citrifolia (noni). METHODS: The influences of noni juice on cell proliferation, apoptosis, invasion, migration and the activity of AKT/nuclear factor- κ B (NF- κ B) signaling pathway in A549 human lung cancer cells were detected by MTT, cell counting kit-8, colony formation, Annexin V/PI double labeling, transwell, scratch test and immunoblotting assay, respectively. A549 cells were inoculated into the right axilla of nude mice, followed by noni juice treatment. The body weight of the nude mice was weighed, and the tumor volume and weight were measured. Cell proliferation and expression of apoptosis-related proteins were measured by immunohistochemistry, and the activity of NF- κ B signaling pathway was measured by immunoblotting. RESULTS: The in vitro studies showed that noni juice inhibited the A549 cells proliferation, migration and invasion. Noni juice also promoted cells apoptosis in A549 cells. Immunoblotting assay showed that the phosphorylation level of AKT, p50, and STAT3 proteins was inhibited to different extents after noni juice treatment. The in vivo studies showed that noni juice effectively suppressed tumor formation of A549 cells in nude mice. Noni juice treatment inhibited the expression of Ki67, PCNA, and Bcl-2 protein in the tumor; while promoted the expression of caspase-3 protein. Additionally, we also found that noni juice treatment could restrain the activity of AKT/NF- κ B signaling pathway in the tumor tissue. CONCLUSION: Noni juice inhibited the proliferation of A549 lung cancer cells, induced apoptosis, and inhibited cell invasion and migration via regulating AKT/NF- κ B signaling pathway.

Rapid mycoplasma culture for the early diagnosis of Mycoplasma pneumoniae infection.

Early diagnosis of Mycoplasma pneumoniae (Mp) plays a pivotal role in its management. We evaluated the role of rapid culture method in early diagnosis of Mp infection and discussed the potential impact factors. A total of 2,600 patients with acute respiratory infection were included, and their pharyngeal swab samples were prepared for Mp rapid culture based on selective Mp fluid culture medium. The clinical contributing factors related to Mp infection were also explored. The positive rate of Mp culture in females was 41.75%, which was higher than that for males (37.63%). Mp infections were incidental to the children and elderly. The positive rates of Mp culture were higher in children aged 3-5 years and adults older than 70 years (54.05 and 31.48%, respectively), compared with other ages. In addition, Mp infection frequently occurred in winter (December-February) and spring (March-May), with significantly higher positive rates of Mp culture by 40.02 and 42.89 vs. 32.15 and 33.50% in summer (June-August) and autumn (September-November), respectively. The positive rate of rapid culture for Mp was slightly higher than that by Mp antibody assay, but the diagnostic accordance was well between these two methods (P>0.05). Furthermore, clinical common symptoms of respiratory tract infection, such as fever, cough, and expectoration, were not found specific in Mp infection, suggesting that they were not independent prognostic predictors for Mp infection. Therefore, rapid culture based on the Mp pathogen detection would have important clinical application for the early diagnosis of Mp infection.

[Enhancing effect of matrine on the tumor-inhibition by TIM2 gene-modified hepatocarcinoma H22 cells in mice].

OBJECTIVE: To investigate the effects of matrine on the anti-tumor efficiency of TIM2 gene-modified murine hepatocarcinoma H22 cells. METHODS: A combined eukaryotic expression vector pIRES2-EGFP-TIM2 was constructed and transfected into H22 cells by lipofectamin. The monoclone of positive H22-TIM2 cells and negative control H22-EGFP cells transfected with pIRES2-EGFP vector were selected by G418 pressure and limited dilution method in turn and were inoculated to establish the tumor-bearing mouse model. Next, matrine was administered to the tumor-bearing mice and the inhibitory effect of matrine was determined. RESULTS: The co-expression of EGFP protein and TIM2 gene was detected in H22 cells selected after TIM2 gene transfecion. After subcutaneous injection of H22-TIM2 cells, the rate of tumor formation (41%) was lower than that of H22 cells and H22-EGFP cells injection (92%) in mice. The tumor growth was significantly inhibited in mice vaccinated with H22-TIM2 cells. After the experiment was completed, the volume of tumors in mice of H22-TIM2 group was 31.34 +/- 9.21 mm3, smaller than those in H22-EGFP group (98.25 +/- 25.23)mm3 and H22 cells group (114.08 +/- 36.45)mm3 (P < 0.01). Matrine dramatically enhanced the anti-tumor efficiency of TIM2 gene-modified H22 cells, with the highest tumor inhibitory rate (IR) 90.6% among the H22-TIM2 group, matrine treatment group and H22-EGFP cells combined with matrine treatment group (69.2%, 67.5% and 70.8%, respectively) in the experimental mice. CONCLUSION: The tumorigenesity of H22 cells has been markedly impaired after modification by TIM2 gene. Matrine can enhance its inhibitory effect on tumors of H22-TIM2 cells in vivo. These data indicate importance to further study on the biological role of TIM2 gene in tumor immunity and explore the molecular mechanism of matrine in suppressing of tumor growth.

[Effects of matrine on oncogenicity of H22 cells modified by TIM2 gene in vivo].

OBJECTIVE: To investigate the effects of matrine on the anti-tumor efficiency of H22 murine hepatocarcinoma cell-based vaccine modified by TIM2 gene in vivo. METHOD: The combinant eukaryotic expression vector pIRES2-EGFP-TIM2 was constructed and transfected into H22 cells by lipofectamin. The monoclone of the positive H22-TIM2 cells and negative control H22-EGFP cells were selected by G418 pressure and limited dilution method in turn. The H22 whole-cell-based vaccine were inoculated to establish the tumor-bearing mouse model, and its oncogenicity and immunogenicity were observed in vivo. Then the matrine was administered to the tumor-bearing mice inoculated by H22-TIM2 cells, H22-EGFP cells and H22 cells, and the inhibitory effect of matrine on tumor was studied. RESULT: The co-expression of EGFP protein and TIM2 mRNA were detected in H22-TIM2 cells. The rate of tumor formation in mice injected of H22-TIM2 cells was 41%, lower than that of H22 cells and H22-EGFP cells injection (92%) in mice. The growth of tumor were significantly inhibited vaccinated with H22-TIM2 cells in mice. The inhibitory rate of tumor (IR) was 69.2% in mice of H22-TIM2 group, higher than that of mice treated with matrine and H22 cells injection, the later was 67.5%. Matrine could dramatically strengthen the anti-tumor efficiency of H22 cells modified by TIM2 gene, with the highest tumor inhibitory rate (IR) (90.6%) in all the experimental mice. The spleen index, populations of CD4-positive lymphocytes and the ratio of CD4-positive to CD8-positive lymphocytes of spleen in mice vaccinated of H22-TIM2 cells were obviously higher than those in the other groups. CONCLUSION: The oncogenicity of H22 cells is markedly impaired after modified by TIM2 gene. Matrine can strengthen the inhibitory effect of H22-TIM2 cells on tumor in mice. These data give us important clues to further study the biological role of TIM2 gene in tumor immunity and explore the molecular mechanism of matrine in suppressing tumor.

[Inhibition of tumor growth in tumor-bearing mice treated with matrine].

OBJECTIVE: To investigate the inhibitory effect of matrine on tumor growth in tumor-bearing mice and explore its possible mechanisms of anti-tumor action in vivo. METHODS: Hepatocellular carcinoma cells H(22) were subcutaneously injected into BALB/c mice and matrine was administered to the tumor-bearing mice. The kinetics of tumor formation and tumor growth were measured, tumor growth inhibition rate (IR) was calculated, and tumor tissue samples were taken and examined by light and electron microscopy to assess the inhibitory effects of matrine on tumor growth in the mice. RESULTS: Marked inhibitory effect of matrine on the transplanted hepatocellular carcinoma H(22) was observed in the tumor-bearing mice. The inhibitory rates were 62.5% and 60.7% in the groups treated with high and low dosage of matrine, respectively (P < 0.01 vs. control group). The tumor formation was significantly retarded and tumor growth was inhibited in matrine-treated groups compared with those in control mice. Histopathological examination revealed widespread necrosis with massive accumulation of infiltrating lymphocytes and plasmacytes in the tumors. Numerous apoptotic cells and apoptotic bodies were observed in the tumors under the electron microscope. CONCLUSION: Matrine has marked inhibitory effects on tumor growth in vivo, which is probably related to inhibition of cell division and tumor cell proliferation, directly killing of tumor cells and/or induction of apoptosis and modulation of anti-tumor immune responses.

[Construction of eukaryotic expression vector of unknown KH gene and its effect on cell proliferation].

OBJECTIVE: To construct an eukaryotic expression vector of open reading frame of unknown KH gene (KH-ORF), and investigate its effect on cell proliferation. METHODS: The pCI-neo-KH-ORF expression vector was constructed by DNA recombinant technique and was introduced into COS-7 cells and K562 cells by lipofectactin-mediated DNA transfection. Expression of KH-ORF mRNA was detected by RT-PCR. The effect of KH-ORF on cell cycle of COS-7 cells and K562 cells was evaluated by flow cytometry (FCM). Effect on cell proliferation of COS-7 cells was tested by MTT assay and that on K562 cells was analyzed by growth curves and LDH activity measurement. RESULTS: (1) KH-ORF mRNA was expressed both in COS-7 cells and K562 cells. (2) The cell cycle and cell proliferation of COS-7 cells were unaffected significantly. (3) The proportion of cells in S phase was increased in pCI-neo-KH-ORF-transfected K562 cells; and growth curves and LDH activity indicated enhanced cell proliferation. CONCLUSION: KH gene may be a leukemia gene related to proliferation of K562 cells.

[Effects of matrine on the expression of NKG2D ligands in leukemia cells].

This study was aimed to analyze the expression of NKG2D ligands in human leukemic cells and to investigate the effects of matrine on NKG2D ligand expression. The expressions of NKG2D ligand MICA/B, ULBP1-3 in several human leukemia cell lines (K562, OUN-1, U937 and K562/AO2), as well as primary leukemic cells isolated from malignant leukemia patients were analyzed by flow cytometry. After treatment with different doses of matrine, the expression level of NKG2D ligands in these leukemic cells was detected by FCM. The results indicated that NKG2D ligand expression was detected in both the leukemia cell lines and primary malignant leukemic cells. Generally, the expression of ULBP was high or obviously higher than that of MICA/B in leukemia cell lines and primary leukemic cells. The expression pattern of NKG2D ligands was different among these cells, possibly due to the different types of leukemia. Not all the expression of NKG2D ligands was upregulated after matrine treatment. Much higher expressions of ULBP2 and ULBP3 were found in K562 cells, compared to the other cell lines, which partly contributes to the higher sensitivity of K562 cells to NK cytotoxicity as target cells. It is concluded that there is universal expression of NKG2D ligand in leukemia cells. The high ULBP expression is prevalent in human leukemia cells. Matrine has the potential to induce the expression of NKG2D ligands in leukemia cells.

[Enhanced cytotoxicity against leukemia cells of natural Killer cells from cord blood after expansion in vitro].

OBJECTIVE: To investigate the enhanced cytotoxicity against leukemia cells of natural Killer (NK) cells from cord blood (CB) after expansion in vitro. METHODS: NK cells was expanded on a layer of trophoblast cells with irradiated K562-mb15-41BBL cell line for 21 days. The levels of receptors on NK cells were detected by flow cytometry. Cytotoxicity of expanded NK cells against leukemia cells and specific ligand of immunoglobulin like(Ig- liKe)receptors were assessed using 51Cr released assay. RESULTS: There were no differences of inhibitory receptors expression between fresh NK cells and expanded NK cells [CD158a:(16.77±11.65)% vs(14.37±11.12)%, P>0.05; CD158b: (42.48±18.11)% vs (40.92±19.02)%, P>0.05; NKG2A: (70.20±18.43)% vs (78.90±13.69)%, P>0.05], but higher activated receptors expression on expanded NK cells [NKp30: (54.10±13.27)% vs (4.14±2.05)%, P<0.05; NKp44: (72.10±17.30)% vs (0.52±1.16)%, P<0.05; NKp46: (80.63±14.01)% vs (44.19±6.19)%, P<0.05; NKG2D: (97.50±2.55)% vs (72.25±14.35)%, P<0.05]. Expanded NK cells showed higher cytotoxicity against leuKemia cell lines than fresh NK cells [K562: (74.3±3.6)% vs (55.3±4.2)%, P<0.05; Raji: (60.6±5.0)% vs (12.0±3.6)%, P<0.05]. CD158a⁻ CD158b⁻ NK cells had higher cytotoxicity on four types of target cells, but CD158a⁺CD158b⁻ CB-NK cell had lower cytotoxicity on 221-Cw4 and 221-Cw3Cw4 cells. CD158a⁻ CD158b⁺ CB- NK cells had lower cytotoxicity on 221-Cw3 and 221-Cw3Cw4, but CD158a⁺CD158b⁺ CB-NK cells had higher cytotoxicity on 721- 221 cells. CONCLUSION: Expression of activated receptors of expanded NK cells were up-regulated, but no changes of inhibitory receptors. Expanded NK cells showed high cytotoxicity against leukemia cells and kept the specificity of ligand of Ig-like receptors, which could be beneficial to cell-therapy for tumor.

[Roles of NKG2D in cytokine-induced killer (CIK) against hematological malignant cells lines].

This study was purposed to investigate the CIK cell cytotoxicity to hematological malignant cell lines by interaction NKG2D receptors and corresponding ligands. The CIK cells was expanded from healthy individual with interferon (IFN)γ, CD3 monoclonal antibodies (mAb) and interleukin-2 (IL-2). The subset of lymphocyte and the expression of NK cell receptors on CIK cells was detected by flow cytometry; NKG2D ligand expression on hematological malignant cell lines was also analyzed by flow cytometry, the calcein acetoxymethyl ester (CAM) was used for labeling target cells, then the cytotoxicity of CIK cells to hematological malignant cell lines was detected by flow cytometry. The results showed that most of CIK cells expressed CD3 (97.85 ± 1.95%) , CD3(+)CD8(+) cells and CD3(+)CD56(+) cells increased significantly as compared with un-cultured cells (P < 0.001;P = 0.033). About 86% CIK cells expressed NKG2D receptor but no other NK receptors such as CD158a, CD158b and NCR. Different levels of NKG2D ligands were detected in hematological malignant cell lines U266, K562 and Daudi. CIK cells showed high cytotoxicity to these three different cell lines, and this cytotoxicity was partially blocked by treating CIK cells with anti-NKG2D antibody (U266 52.67 ± 4.63% vs 32.67 ± 4.81%, P = 0.008;K562 71.67 ± 4.91% vs 50.33 ± 4.91%, P = 0.007;Daudi 68.67 ± 5.04 vs 52.67 ± 2.60%, P = 0.024) . It is concluded that most of CIK cells express NKG2D receptor, interaction of NKG2D-NKG2D ligands may be one of the mechanisms, by which CIK cells kill hematological malignant cells.

[NKG2D-mediated natural killer cell cytotoxicity against myeloid leukemia cells OUN-1].

OBJECTIVE: To investigate NK cell cytotoxicity to leukemic cell by NKG2D receptors and NKG2D ligands interaction upregulated by hydroxyurea (HU). METHODS: Leukemic cell lines OUN-1 and primary leukemic cells were cultured for 24 hours in the presence of HU, then the NKG2D ligands expressions were analyzed by flow cytometry (FCM). Isolated NK cells from healthy individual cultured for 72 hours in presence of IL-2 were used as effect cell, and leukemic cell line OUN-1 treated with HU was used as target cell, NK cell cytotoxicity against leukemic cell line was assessed using chromium-51 release assay. RESULTS: Leukemic cell lines showed upregulation of MIC A/B (MFI: 8.9 ± 0.9 vs 23.5 ± 3.4, P = 0.01) and ULBP2 (MFI: 14.5 ± 0.6 vs 33.5 ± 4.8, P = 0.03) following incubation with HU. HU also upregulated the NKG2DLs on primary leukemia cells from patients with acute myeloid leukemia. Treatment of OUN-1 with HU significantly increased the cytotoxicity of NK cells isolated from healthy individual \[(62.0 ± 5.6)% vs (76.0 ± 5.3)%, P = 0.02\], and the enhancing effect of HU was partly blocked by anti-NKG2D Abs \[(76.0 ± 5.3)% vs (46.0 ± 4.5)%, P = 0.00\]. CONCLUSION: HU selectively upregulated NKG2D ligand expression on leukemic cell lines, and enhanced NK cell cytotoxicity against leukemic cells through NKG2D receptors and NKG2D ligands interaction.

Effects of STAT3 silencing on fate of chronic myelogenous leukemia K562 cells.

Signal transducer and activator of transcription 3 (STAT3), a transcription factor, is constitutively activated in various types of cancers. Previous investigations have demonstrated that this overexpression of STAT3 in human malignancies plays important roles in maintaining the characteristics of malignant tumors by having an effect on proliferation, differentiation, and/or immortalization. Thus, inhibition of STAT3 expression could be a potent therapeutic approach in cancer treatment. In this study, we introduced STAT3 siRNA into the human chronic myelogenous leukemia (CML) K562 cell line, which has constitutive activation of STAT3, to elucidate the role of STAT3 in CML. The cells were transducted with STAT3 siRNA using lentivirus. FACS, real-time PCR, and Western blot were used to study changes in STAT3 expression levels in transducted cells by comparing with negative control siRNA lentivirus transduction. Knockdown of STAT3 by STAT3 siRNA caused a decrease in STAT3 protein level, inhibition of growth and proliferation, cell cycle blockade, visible morphologic changes, and induction of apoptosis in K562 cells. These findings demonstrate that STAT3 does indeed play a critical role in the survival of K562 cells, which may have potential application in designing molecular therapies for CML treatment.

[Gene expression profile in early differentiation of K562 cells induced by matrine].

OBJECTIVE: To compare gene expression profile in K562 cells induced by matrine, so as to screen for differentiation related genes. METHODS: K562 cells were exposed to 0.1 mg/ml matrine for 3 hours, and gene expression profiles in matrine-treated and non-treated cells were studied by cDNA microarray. RESULTS: From 8465 screened genes, 30 differentially expressed genes were found. Among them 18 showed decreased expression including oncogene and proto-oncogene, signal transduction gene, DNA binding and transcription gene etc, 12 showed increased expression including cell receptor gene, immune-associated gene, metabolism-associated gene etc in matrine-treated K562 cells as compared with that in non-treated cell. CONCLUSION: The genes, that are closely associated with differentiation of can-cer cell, could be the potential targets for cancer treatment.