previous studies have shown that mTOR inhibition is of a fee

previous studies have shown that mTOR inhibition is associated with a feedback activation of AKT which might result in resistance to mTOR inhibition, no significant increase in the phosphorylation of AKT was observed in a reaction to RAD001 in these CCC cell lines. Growth amount of RAD001 treated mice was in contrast to that of placebo treated mice and analyzed by Wilcoxon exact test. Ibrutinib 936563-96-1 Immunoreactivity was analysed using Fisher s exact test. The frequency of solid phospho mTOR immunoreactivity was significantly greater, and frequency of tumors without any immunoreactivity was significantly lower in CCCs than in SACs. These results show that CCCs might be more highly dependent on mTOR for tumor progression than SACs. When analyzed by medical stage, phospho mTOR expression was noticed in 96-cell of early stage CCCs and in 76-year of advanced level stage CCCs. Thus, most patients with CCC could be candidates for therapy with a mTOR chemical. In contrast, in SACs, phospho mTOR term was uncommon in early stage tumors, even though it was considerably increased in advanced stage tumors. Neuroendocrine tumor Consequently, in SACs, mTOR inhibition might be a therapeutic alternative only in higher level stage infection. Collectively, these results suggest that pharmacologic inhibition of mTOR can be a promising therapeutic approach in the administration of CCCs, both in higher level stage infection and in early stage. In vitro expansion inhibitory influence of RAD001 on cisplatin sensitive CCC cell lines Given the repeated mTOR activation found in human CCC cancer types, we evaluated the expression of phospho mTOR in four human CCC cell lines by western blotting. As shown in Fig. 2A, under serum misery circumstances, mTOR was phosphorylated in all CCC cell lines tested, that will be consistent with immunohistochemical effects seen with cyst samples. We next examined the efficacy of mTOR Erlotinib ic50 route inhibition by RAD001 about the expansion of CCC cells in vitro. For this specific purpose, we executed a MTS assay using two of the CCC cell lines with activated AKT/mTOR signaling. As shown in Fig. 2B, RAD001 inhibited the expansion of KOC7C and RMG1 cells in vitro, with 25% inhibition at the best drug concentration tested. RAD001 attenuates phosphorylation of p70S6K in vitro To ascertain if the anti-proliferative effects of RAD001 result from inhibition of mTOR signaling, we examined the effect of RAD001 around the phosphorylation of downstream p70S6K in RMG1 and KOC7C cells. AKT, mTOR and p70S6K were phosphorylated in both cell lines, indicative of the hyperactivation of the AKT/mTOR pathway. Phosphorylation of the downstream effector p70S6K was considerably decreased in both cell lines by therapy with RAD001, revealing that RAD001 efficiently inhibits mTOR signaling in CCC cells, not surprisingly.

Different NMR spectra provided evidence for significant acti

Different NMR spectra provided evidence for considerable motion in this region. We observed the broadening of imino protons corresponding to guanines 1, 6, 10 and 14. Broadening was also observed for a few non exchangeable protons of those residues. Because every one of these guanines are located at the dimeric interface, this clearly confirms activity in this region. Possible kinds of motion include HDAC inhibitors list inter conversion between dimer and monomer or rotation of two sub-units concerning the main axis. . We could eliminate the stacking between the two G quadruplex monomers from the addition of two extra thymine bases at the 50 end. Serum electrophoresis experiments demonstrably showed the difference between two structures: the monomer migrated even faster compared to dimer.. The monomeric character of T30177 I11 TT and T30177 TT were supported by the independence of these melting temperature around the DNA concentration. Our unpublished NMR data established that T30177 TT forms a monomeric propeller kind parallel trapped Gary quadruplex within this condition. G rich oligonucleotide T30177 forms a dimeric structure involving two subunits Immune system of propeller type parallel stuck G quadruplexes, that are stacked at their 50 end. All guanines in the sequence participate in G tetrad formation and there’s a bulge of the T residue in each subunit. This work and also other structural studies. pointed to the synthesis of dimeric parallel stuck G quadruplexes containing a total of six G tetrad levels by different G rich oligonucleotides that get HIV 1 integrase inhibition activity. Several in vitro and in vivo models have unmasked the main element role of CXCR4/CXCL12 axis in tumor stroma interactions. Stromal cells present in the tumefaction micro-environment show high degrees of CXCL12 protein, immediately stimulating migration and proliferation of CXCR4 showing cancer cells. E2 conjugating This unique prosurvival impact of stromal cells on tumor cells is considered to . cancers defend them from cytotoxic chemotherapy and is postulated just as one explanation for the minimal residual illness in hematological and solid. Therefore, CXCR4/CXCL12 signaling is an appealing therapeutic goal in cancer, as proven in pre-clinical leukemia mouse styles, where CXCR4 inhibition sensitized cancer cells to traditional chemotherapy. This study investigates whether inhibition of CXCR4 using the specific chemical AMD3100 sensitizes human prostate cancer cells to docetaxel. We showed that both mouse and human stromal cell lines possess a protective impact on PC3 luc cells by endorsing their survival after chemotherapy. More over, we demonstrated that AMD3100 sensitizes PC3 luc cells to docetaxel. In a subcutaneous xenograft mouse model of human prostate carcinoma, we showed a mixture of docetaxel and AMD3100 puts increased anti-tumor effect in contrast to docetaxel alone.

qPCR studies were performed on components obtained at differ

qPCR analyses were performed on mobile components obtained at various time points after disease to measure the effect on early replication events and virus entry. HIVCX05045 Fingolimod supplier joined cells as efficiently as HIVDMSO in a synchronized infection as determined by quantification of gRNA by RT qPCR analysis at 2 hpi. . Needlessly to say, heat inactivation of herpes or inclusion of the access inhibitor DS10000, however not the RT inhibitor efavirenz, led to paid off gRNA copy number. We next examined the RT stage by profiling viral DNA synthesis kinetics using qPCR research. In comparison to HIVDMSO, we observed a five fold drop in the quantities of both early and late reverse transcripts in from HIVCX05045 infected cells ingredients at 12 hpi. As evidenced by back ground level of both early and late RT services and products, representing that HIVCX05045 bears useful RT efavirenz blocked reverse transcription of both viruses. Of note, CX05045 stops RT neither in vitro or in vivo. In comparison to HIVDMSO infected cells, background Organism degrees of 2 LTR sectors and built-in copies were shown in cells infected with HIVCX05045, suggesting that the disease displays additional defects at the nuclear import step. . Needlessly to say, the integration block borne by raltegravir during infection was accompanied by a rise in 2 LTR circles in cells infected with HIVDMSO. But, we observed a background level of 2 LTR groups in HIVCX05045 infected cells, which remained similar even after raltegravir treatment, indicating that there is little or no viral cDNA translocated to the nucleus. The reduced amount of 2 LTR communities raised the question whether HIVCX05045 can be defective for nuclear transfer of the PIC, a meeting considered to be at least partially dependent Dasatinib ic50 on the dynamic interaction between IN carried inside the PIC and karyopherins. To deal with this dilemma, we executed a nuclear PIC import assay using fluorescently labeled HIV 1 particles. We developed VSV. H pseudotyped particles, carrying fluorescently marked IN through Vpr mediated transincorporation, in the presence of CX05045 or DMSO. HeLaP4 cells were infected with either HIVCX05045 or HIVDMSO after normalizing for p24 antigen. The catalytically lazy IND64E encoded by the proviral construct was properly transcomplemented by the Vpr fused IN eGFP as determined by activity at 48 hpi. In two independent experiments, the cellular distribution of the PICs was assessed in cells at 7 hpi and the amount of total and nuclear PICs was quantified by confocal microscopy. Furthermore, an analysis of the final distribution chance unveiled a statistically significant variation between HIVCX05045 and HIVDMSO.

classes of antiretroviral drugs that attack HIV 1 at various

classes of anti-retroviral drugs that attack HIV 1 at various points in the viral replication cycle could be useful additions to the microbicide development pipeline. The reduced genital tract of women constitutes Ibrutinib price an important site for HIV invasion. For that reason, prevention of natural infection will be a important landmark in minimizing the global AIDS epidemic. While male condoms are very effective at stopping vaginal human immunodeficiency virus transmission, girls are frequently not empowered to negotiate their use by their sexual partners or may object to their use due to sociocultural norms or the want to conceive. The most reliable long term method of HIV prevention is a vaccine, since it would confer protection, but a successful HIV 1 vaccine is unlikely to emerge in the near future. Hence, alternative strategies are urgently required to slow the spread of HIV. Systemic anti-viral preexposure prophylaxis and vaginally or rectally provided as preventive tools topical microbicides are getting increased attention. Thus far, polyanion external microbicides, pHbuffering, and only soap have completed testing in large scale clinical trials. With one recently described potential exception, none of those nonspecific microbicides has demonstrated a protective effect against vaginal HIV transmission. An increased risk of HIV transmission was indeed noted for the soap nonoxynol 9. These disappointing Endosymbiotic theory results have experienced two major effects on the microbicide industry. . First, efforts have increased to develop and standardize pre-clinical and animal testing types with high predictive power for medical microbicide efficacy. The effective use of these models in appropriate screening formulas must have the capability to screen out compounds such as cellulose sulfate before they enter stage II and III clinical trials. Second, the emphasis has shifted to materials with certain antiretroviral activity. Like, the reverse transcriptase inhibitors tenofovir, that is currently used to treat HIV infection, and dapivirine CX-4945 price are currently entering as prophylactic vaginal gel formulations in phase III efficacy trials and phase IIb screening. There are concerns, nevertheless, the usage of as microbicides RTIs might boost the spread of HIV 1 resistance. They include more HIV certain fusion and entry inhibitors some of which may have already demonstrated protection of macaques from transmission of simian human immunodeficiency virus as well as integrase inhibitors. Recently, enhanced animal models using humanized and macaques rats have now been developed which could become a part of a consistent go/no go decision algorithm for candidate microbicides under development. But, these animal models have drawbacks.

Tissue sections were cut from blocks of formalin fixed paraf

Tissue sections were cut from blocks of formalin fixed paraffin tumefaction tissue from glioblastoma patients treated with lapatinib or rapamycin. These TMAs have now been used for other studies. TUNEL Staining Paraffin sections were deparaffinized buy Lenalidomide and subjected to graded rehydration much like the immunohistochemical method. Peroxidase activity was quenched with three full minutes hydrogen peroxide in water.. TUNEL staining was done utilizing digoxigenin conjugated dUTP and HRP conjugated anti digoxigenin antibodies following its protocol. Creation for staining was done with NovaRed substrate and areas were then counterstained with hematoxylin. For TUNEL immunofluoresence staining, tissue sections were stained for apoptosis utilising the In Situ Cell Death Detection Kit, TMR red and as a result of its protocol. ChIP assays were done on U87 EGFR cells 4 hours of EGF treatment. Cells in two 15 cm plates were pooled for each 8 repeat. Processor was done essentially as described. Fleetingly, cells were crosslinked for five minutes in 10 percent formaldehyde in PBS. After considerable Urogenital pelvic malignancy sonication, pre cleaning with protein G sepharose, and removal of a 50 uL portion for normalization, soluble chromatin from each copy was divided three ways for over night immunoprecipitations with 2 ug of these antibodies: Mouse IgG, anti Pol II, or anti SREBP1. DNA Protein buildings were pulled down by incubation for 2 hours with protein G sepharose, washed, and processed as previously described. gDNA was assayed by qPCR with primers augmenting the FAS transcription start site, and a fragment upstream of the Transcription Start Site. Isogenic human U87 malignant glioma cells were implanted into immunodeficient SCID/Beige mice for subcutaneous xenograft studies. SCID/Beige mice were bred and maintained under identified flora pathogen free conditions in the AALAC accepted Animal Facility of the Division of Experimental Radiation Oncology, UCLA. BAY 11-7082 BAY 11-7821 For s. . c. implantation, significantly growing tumefaction cells in culture were trypsinized, included by Trypan Blue exclusion, and re-suspended at 1 106 cells/ml in an answer of dPBS and Matrigel. Tumefaction growth was checked with calipers by measuring the perpendicular diameters of each and every s. H. Cyst. U87 and U87 EGFRvIII cell lines were inserted s. c. on opposite sides of the mouse belly for therapy with atorvastatin, C75 alone or in combination. Mice were euthanized if tumors reached 14 mm in maximum height, or animals showed signs of illness. All tests were conducted after approval from the Chancellors Animal Research Committee of UCLA. Tumor specimens were obtained based on a project accepted by the Institutional Review Board of UCLA. The first pair of paired pre and post treatment tumor tissues for lapatinib trial, and 9 sets of pre and post treatment tumor tissues for the rapamycin trial, were examined.

Receptor proteins were precipitated from mobile lysates with

Receptor proteins were precipitated from mobile lysates with a commercial antibody against HER2 or with a non commercial antibody against HER1/EGFR. Lapatinib blocks EGFR and HER2 service We’ve pan Aurora Kinase inhibitor shown previously that both lapatinib and erlotinib, an EGFR selective tyrosine kinase inhibitor, prevent the growth agar soft of many pancreatic cancer cell lines1. . Because EGFR 5 inhibition has been proven to radiosensitize other cancers, including head and neck squamous cell carcinomas and breast cancer, we sought to find out whether these substances could also radiosensitize pancreatic cancer cells and whether this radiosensitization correlated with EGFR and HER2 expression. We first evaluated by qRT PCR the relative expression levels of all four members of the family of receptors among a panel of four pancreatic cancer cell lines. EGFR levels were 10-17 fold greater in the PANC 1 and T3M4 cells relative to that seen in the Capan 2 and MIA PaCa 2 cells, while HER2 levels were similar among all four lines. Appearance of HER3, a member of family that lacks kinase activity, was approximately 10-fold higher in the T3M4 cells and Capan 2. HER4, the last relative, had really low mRNA expression levels across all four cell lines. All cell lines showed an anti proliferative effect in response to increasing concentrations of both lapatinib and erlotinib. The dual EGFR/HER2 messenger RNA (mRNA) inhibitor lapatinib demonstrated improved growth inhibitory activity in comparison to erlotinib in 2 and MIA PaCa 2 cell lines, a finding consistent with low levels of EGFR mRNA in these cell lines. T3M4 cells and PANC 1 had higher degrees of EGFR than HER2 expression, and exhibited equivalent growth inhibition by erlotinib and lapatinib. To show that lapatinib blocks ligand stimulated EGFR and HER2 activation in our pancreatic cells activation of receptors was assessed by immunoprecipitation adopted by western blot analysis. In keeping with what we Bicalutamide Cosudex and others have previously reported using in vitro, in vivo, and individual samples and reviewed in, lapatinib blocked activation of both EGFR and HER2 in every four pancreatic cell lines. . Pancreatic cancer cell lines harboring K ras mutations are resistant to lapatinib mediated radiosensitization Because of the improved anti proliferative and ligand triggered receptor inhibition of lapatinib inside the examined cell lines, we made a decision to examine whether lapatinib could radiosensitize pancreatic cancer cells. Clonogenic success assays were performed on our panel of cells that were both treated with lapatinib or vehicle alone for your 2 hours previous and 2 hours after irradiation. We chose this short duration of drug therapy since the clonogenic survival and cell cycle distribution of non irradiated cell lines that were pretreated in this style with either lapatinib or DMSO control weren’t statistically different, suggesting that the 4 hour exposure to lapatinib didn’t radiosensitize cells only by inhibiting proliferation or by redistributing cells to a more radiosensitive phase of the cell cycle.

The decrease in total retinal thickness was mainly due to a

The decrease in over all retinal breadth was primarily due to a thinning of the inner retina layers. Retinas were incubated in Extravidin BAY 11-7082 BAY 11-7821 solution at room temperature for 2 h in the dark. Following PBS washing, each retina was incubated utilizing a PharMingen DAB substrate Kit before the desired color intensity developed. microscopic images were captured, and cell counts were analyzed, like the DTMR described retina flatmounts. Scotopic ERG was used to assess potential injury to the outer retinal layer by the elevated IOP. Briefly, animals were dark adapted over night and anesthetized. The pupils were dilated with Mydfrin and corneas were anaesthetized with Alcain. White light flashes were made by a photostimulator placed 25 cm in front of the rats eye. The answers were recorded and analyzed by data wave electroretinogram selection computer software. Before IOP was elevated baselines of The and Bwave amplitudes were gathered. They were used as an assessment against the respective ERG values obtained DNA-dependent RNA polymerase at the indicated time position after IOP elevation. As previously reported, the suture pulley process creates rat ocular hypertension, the degree of which depends upon the weights connected to the ends of the suture. These photographs show a duration dependent reduction in GCL cell density and loss of the inner retinal layer after 7 h of IOP elevation. Quantification of those improvements demonstrated that overall retinal thickness did not alter significantly, except in the 7 h IOP level team. Ocular hypertension for up to 7 h did not influence the thicknesses of the ONL, OPL, or INL. ALK inhibitor Significant cell loss in the GCL was observed in all three experimental groups compared to the control group. These changes within the retina ensure the period dependent ON damages induced by elevated IOP. Loss in DTMR Labeled RGCs Induced by IOP Elevation: To corroborate the ocular hypertension induced reduction of cells in the GCL, DTMR labeled RGC counts were done on retina flatmounts derived from eyes where the IOP was elevated to 45 mmHg for 7 h. Figure 4A shows representative pictures of retinas at different time points, from 3 days to 28 days, following a 7 h, 45 mmHg IOP elevation. It’s obvious from these pictures that gradual RGC damage was obvious following the insult. Quantitative analysis of this information is presented in Figure 4B. Hence, the occurrence of DTMR labeled RGC in the get a grip on Figure 1. Intraocular pressure elevation utilising the suture pulley technique. These findings suggest the outer retina wasn’t functionally destroyed by the morphological findings are confirmed by this procedure, which shown in Figure 3. Time-dependent histological changes of rat optic nerves induced by ocular hypertension. Examination was performed one month after the injury.

Still another frequent alteration resulting in activation of

Yet another frequent modification resulting in activation of PI3K signaling in human cancers will be the inactivation of the phosphatase and tensin homolog cyst suppressor through somatic mutations that bring about protein truncation, homozygous or hemizygous deletions, or epigenetic silencing. The PI3K signaling pathway regulates various cellular processes, including proliferation, survival, and Dub inhibitors metabolic rate, and is aberrantly stimulated in human cancer. Therefore, numerous compounds targeting the PI3K pathway are being clinically evaluated for treating cancer, and several demonstrate some early signs of efficacy in breast cancer. But, resistance against these agents, both de novo and acquired, may possibly fundamentally limit the efficacy of these compounds. Here, we have taken a thorough functional method of uncovering potential elements of resistance to PI3K inhibitors and have identified many genes whose expression promotes survival under circumstances of PI3K/mammalian target of rapamycin blockade, such as the ribosomal S6 kinases RPS6KA2 and RPS6KA6. We show that overexpression of RSK3 or RSK4 supports growth upon PI3K inhibition both in vitro and in vivo, in part through the attenuation of the apoptotic response and upregulation of protein translation. Somewhat, the improvement of MEK or RSK specific inhibitors could over come these opposition phenotypes, both in breast cancer cell lines and individual derived xenograft types locomotor system with elevated levels of RSK activity. These observations provide a strong reason for the combined usage of PI3K and RSK path inhibitors to elicit favorable responses in breast cancer patients with activated RSK. The PI3Ks, PKB/AKT, and mammalian target of rapamycin axis is integral for various physical processes, including growth, growth, survival, and metabolic process. Strains of a few components of the PI3K pathway that cause constitutive ubiquitin conjugating activation of this pathway are observed in human cancer. . Specifically, members of the class IA PI3K family, which are heterodimers comprising a p85 regulatory and a p110 catalytic subunit, are often mutated in solid tumor types, including breast, lung, ovarian, prostate, colorectal, and pancreatic cancers. Additionally, other commonly mutated and/or amplified genes are upstream regulators of the PI3K pathway, including EGFR, HER2, IGFR, MET, and RAS, and are known to promote tumorigenicity, at the very least in part through the upregulation of PI3K signaling. Due to the significance of PI3K pathway activation in human cancer, a few small molecule inhibitors targeting the PI3K/AKT/ mTOR pathway are under clinical development for treatment of cancer.. The macrolide rapamycin and its analogs, such as for instance RAD001, particularly prevent mTORC1 and have powerful cytostatic activity in preclinical models.

Degrees of apoptosis after NGF withdrawal were measured by c

Levels of apoptosis after NGF withdrawal were measured by counting the amount of neuronal cell bodies staining positive using an antibody against the activated form of caspase 3, that is elevated during apoptosis in this cell population. Oprozomib Proteasome inhibitors Interestingly, the clear presence of activated caspase 3 in neuronal cell bodies was noticeably reduced in DLK neurons as compared with controls, indicative of a significant defense of DLK neurons from apoptosis induced by NGF withdrawal. . NGF deprivation has also been shown to cause axonal degeneration independent of cell death in NGF dependent cell populations, thus, we next explored whether DLK is also required for axon degeneration using DRG explant cultures. Interestingly, while axons produced from wt DRG explants totally degenerated by 18 h, DLK null neurons exhibited small degeneration at this time point. The axonal protection observed in explant cultures is actually a secondary consequence of the anti-apoptotic ramifications of DLK removal, so we next examined whether DLK affects regional axon degeneration using compartmentalized physical form and external structure chambers that distinct axons from cell bodies. Degeneration of axons proceeds over a similar timeline to that particular seen in explants, when NGF is removed only from the axonal compartment in this experimental setup, but no significant apoptosis does occur during this time period. Much like what was seen in explants, DLK axons exhibited somewhat paid down degeneration after NGF deprivation as weighed against axons from wt littermates. These data argue that DLK is important for both axon degeneration and cell death in response to growth factor deprivation. Significantly, lack of DLK can also be able to drive back local axon damage, arguing that it’s an essential role in this method even yet in conditions by which neuronal apoptosis does not occur. DLK activates a JNK mediated stress response pathway To identify Everolimus price pathways modulated by DLK inside the context of developmental degeneration in mouse, the activation of MAPK pathways was tested in cultured DRG neurons after 3 h of NGF deprivation. This early time point is before significant deterioration but is sufficient to cause a fourfold reduction in the levels of phosphorylated extracellular signal regulated kinase caused by the lack of NGF/TrkA based survival signaling. Levels of p ERK were similar in wt and DLK neurons, arguing that the removal of DLK does not protect neurons via maintaining ERK activity in the absence of NGF. Homeostasis and degrees of phosphorylated JNK and phosphorylated P38 were unchanged currently point, though development. Neurons contain high quantities of activated JNK even in the absence of stress but have the ability to discriminate this exercise from proapoptotic JNK signaling. Studies applying JNK null mice have demonstrated that every of the three mammalian JNK genes has certain characteristics, which explains at least partly how this selectivity is achieved.

The cells were incubated at 37 C in a CO2 incubator for 24 h

The cells were incubated at 37 C in a CO2 incubator for 24 h after transfection. IKK recombinant protein was pull down through the use of c-Met kinase inhibitor Flag tagged protein immunoprecipitation Kit in line with the information. . In quick, after transfection with Flag IKK wt for 24 h, HEK293T cells were washed and collected by PBS for twice. The mobile lysates were prepared by incubation with lysis buffer for 15min on ice and then centrifuged for 10 min at 12,000 g. Theresin was organized based on the manual, and the cell lysates were agitated for overnight at 4 C and put into the glue. The resin was then washed by wash buffer for three times and collected by centrifuging for 30 sec at 8200 g. Finally, the Flag IKK wt was eluted by opposition with 3 Flag peptide and stored in 80 C for performing IKK kinase assay. ribotide To determine the immediate result of shikonin on IKK action, the IKK kinase assay was performed. . In temporary, both GST IB substrate, FLAG IKK wt recombinant protein, and ATP were incubated with or without shikonin at 30 C for 30 min. The mixture was analyzed by 10 percent SDS polyacrylamide gel electrophoresis and then electrotransferred onto nitro-cellulose filters.. Thenitrocellulosemembraneswere blocked by 50-acre driedmilk for 60min and then incubated with P IB for overnight at 4 C.. Themembranes were washed with TBS T again and further incubated with HRP conjugated secondary antibodies for 60min, next-day. A proven way ANOVA or unpaired Students test was used to determine the importance of huge difference, a value of 0. 05 was considered statistically significant. 3. 3. 1. Shikonin Prevents Human T Lymphocyte Proliferation. Optimum T lymphocyte proliferation requires two signals, one is supplied by the antigen specific T cell receptor complex and the other may be the costimulatory receptor PF299804 solubility CD28. In today’s study, the immobilized OKT3 plus CD28 antibodies in 96 well plates or PMA plus ionomycin were employed to stimulate T cells, and the hallmarks of the cell activation could be observed, namely, cell proliferation and secretion of IL 2 and IFN. Thus, we firstly examined the effect of shikonin on human T cell proliferation, and the confirmed that shikonin could suppress the T cell proliferation induced by OKT 3/CD28 or PMA/ionomycin in a dose-dependent fashion and 1. To determine whether the suppressive influence of shikonin on human T lymphocyte proliferation is resulted from the cytotoxicity of the compound, MTT method was used to evaluate the stability of T cell in the research. To evaluate if the inhibitory effect of shikonin on human T cell growth was mediated by inhibition of IL 2 and IFN secretion, we examined the effect of shikonin on IL 2 and IFN secretion. As shown in Figure 2, IL 2 and IFN were notably released in the cells evoked by PMA/ionomycin, while this increased secretion could possibly be removed by treatment of shikonin in a dose dependent fashion.