PPAR-γ Activation Exerts an Anti-inflammatory Effect by Suppressing the NLRP3 Inflammasome in Spinal Cord-Derived Neurons.

Persistent inflammation disrupts functional recovery after spinal cord injury (SCI). Peroxisome proliferator-activated receptor gamma (PPAR-γ) activation promotes functional recovery in SCI rats by inhibiting inflammatory cascades and increasing neuronal survival. We sought to clarify the relationship between PPAR-γ activation and NACHT, LRR and PYD domain-containing protein 3 (NLRP3) inflammasome suppression, and the role of NF-κB in activating the NLRP3 inflammasome in neurons. In SCI rats, we found that rosiglitazone (PPAR-γ agonist) inhibited the expression of caspase-1. In in vitro neurons, G3335 (PPAR-γ antagonist) reversed the rosiglitazone-induced inhibition of caspase-1, interleukin 1 (IL-1ß), and interleukin 6 (IL-6). Rosiglitazone inhibited the expression of NLRP3, caspase-1, IL-1ß, and IL-6. However, the activator of NLRP3 could counteract this inhibition induced by PPAR-γ activation. NF-κB did not participate in the process of rosiglitazone-induced inhibition of NLRP3. Consistent with our in vitro results, we verified that locomotor recovery of SCI rats in vivo was regulated via PPAR-γ, NLRP3, and NF-κB. These results suggest that PPAR-γ activation exerts an anti-inflammatory effect by suppressing the NLRP3 inflammasome-but not NF-κB-in neurons and that PPAR-γ activation is a promising therapeutic target for SCI.

Treponema pallidum recombinant protein Tp47 activates NOD-like receptor family protein 3 inflammasomes in macrophages via glycolysis.

Glycolysis is a key pathway in cellular glucose metabolism for energy supply and regulates immune cell activation. Whether glycolysis is involved in the activation of NOD-like receptor family protein 3 (NLRP3) inflammasomes during Treponema pallidum (T. pallidum) infection is unclear. In this study, the effect of T. pallidum membrane protein Tp47 on NLRP3 inflammasome activation in rabbit peritoneal macrophages was analysed and the role of glycolysis in NLRP3 inflammasome activation was explored. The results showed that Tp47 promoted NLRP3, caspase-1, and IL-1ß mRNA expression in macrophages, enhanced glycolysis and glycolytic capacity of macrophage, and promoted the production of macrophage glycolytic metabolites citrate, phosphoenolpyruvate, and lactate. The M2 pyruvate kinase (PKM2) inhibitor shikonin down-regulated the Tp47-promoted NLRP3, caspase-1, and IL-1ß mRNA expression in macrophages, and suppressed the Tp47-enhanced glycolysis and glycolytic capacity. Similarly, si-PKM2 significantly inhibited Tp47-promoted NLRP3, caspase-1, and IL-1ß mRNA expression and the Tp47-enhanced glycolysis and glycolytic capacity in macrophages. In conclusion, Tp47 activated NLRP3 inflammasomes via PKM2-dependent glycolysis and provided a new perspective on the effect of T. pallidum infection on host macrophages, which would contribute to the understanding of the infection mechanism and host immune mechanism of T. pallidum.

Treponema pallidum protein Tp0136 promotes angiogenesis to facilitate the dissemination of Treponema pallidum.

The incompletely eliminated Treponema pallidum (T. pallidum) during primary syphilis chancre infection can result in the progression of secondary, tertiary, or latent syphilis in individuals, suggesting that T. pallidum has successfully evaded the immune response and spread to distant sites. The mechanism underlying the dissemination of T. pallidum is unclear. Here, a syphilitic rabbit model dorsal-injected with recombinant Tp0136 protein or Tp0136 antibody subcutaneously was used to demonstrate the role of Tp0136 protein in promoting the dissemination of T. pallidum to the testis and angiogenesis in vivo; vascular endothelial cell line HMEC-1 was employed to display that Tp0136 protein enhances the angiogenesis. Furthermore, the three-dimensional microfluidic angiogenesis system showed that the angiogenesis would heighten vascular permeability. Then transcriptome sequencing analysis, in conjunction with cell-level validation, elucidated the critical role of the PI3K-AKT signaling pathway in the promotion of angiogenesis by Tp0136 protein, resulting in heightened permeability. These findings elucidate the strategy employed by T. pallidum in evading immune clearance.

Evaluation of the diagnostic performance of an immunochromatographic test for Chlamydia trachomatis.

Objectives: To evaluate the diagnostic performance of different brands of immunochromatographic test (ICT) reagents for Chlamydia trachomatis using homogenized samples to provide a reference for reagent quality control. Methods: Eight commercially available ICT reagents were evaluated, of which three used the latex method and five used the colloidal gold method. Analytical performance evaluation using a pure culture broth of C. trachomatis, as well as clinical application validation using cervical epithelial cell samples acquired from the research subjects, were conducted. The concentration of C. trachomatis was quantified using a nucleic acid amplification test. Results: The limit of detection (LOD) of different ICT reagents in the analytical performance evaluation varied from 9.5 × 103 to 1 × 105 IFU/mL, and only one reagent met the LOD specified in the manufacturer's instructions. Likewise, only one reagent in the clinical application validation achieved the analytical LOD, four reagents were 2.1-4.2-fold of the analytical LODs, and three reagents failed to detect positive results in clinical samples. Conclusions: The diagnostic performance of different methods and different brands of ICT reagents in clinical practice was different from the manufacturer's instructions and the results of laboratory evaluation. The diagnostic performance of reagents should be evaluated before they are actually used in clinical practice.

Platelet-derived major histocompatibility complex class I coating on Treponema pallidum attenuates natural killer cell lethality.

The evasive tactics of Treponema pallidum pose a major challenge in combating and eradicating syphilis. Natural killer (NK) cells mediate important effector functions in the control of pathogenic infection, preferentially eliminating targets with low or no expression of major histocompatibility complex (MHC) class I. To clarify T. pallidum's mechanisms in evading NK-mediated immunosurveillance, experiments were performed to explore the cross-talk relations among T. pallidum, NK cells, and platelets. T. pallidum adhered to, activated, and promoted particle secretion of platelets. After preincubation with T. pallidum, platelets expressed and secreted high levels of MHC class I, subsequently transferring them to the surface of T. pallidum, potentially inducing an immune phenotype characterized by the "pseudo-expression" of MHC class I on the surface of T. pallidum (hereafter referred to a "pseudo-expression" of MHC class I). The polA mRNA assay showed that platelet-preincubated T. pallidum group exhibited a significantly higher copy number of polA transcript than the T. pallidum group. The survival rate of T. pallidum mirrored that of polA mRNA, indicating that preincubation of T. pallidum with platelets attenuated NK cell lethality. Platelets pseudo-expressed the MHC class I ligand on the T. pallidum surface, facilitating binding to killer cell immunoglobulin-like receptors with two immunoglobulin domains and long cytoplasmic tail 3 (KIR2DL3) on NK cells and initiating dephosphorylation of Vav1 and phosphorylation of Crk, ultimately attenuating NK cell lethality. Our findings elucidate the mechanism by which platelets transfer MHC class I to the T. pallidum surface to evade NK cell immune clearance.

Coexistence of diffuse large B-cell lymphoma, acute myeloid leukemia, and untreated lymphoplasmacytic lymphoma/waldenström macroglobulinemia in a same patient: A case report.

BACKGROUND: The Coexistence of myeloid and lymphoid malignancies is rare. Myeloid leukemia occurs more frequently as a secondary event in patients receiving chemotherapy agents for lymphoid malignancies. Synchronous diagnoses of diffuse large B-cell lymphoma (DLBCL), acute myeloid leukemia (AML), and untreated lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) in the same patient have not been reported. Here we report one such case. CASE SUMMARY: An 89-year-old man had a chest wall mass histopathologically diagnosed as DLBCL. The bone marrow and peripheral blood contained two groups of cells. One group of cells fulfilled the criteria of AML, and the other revealed the features of small B lymphocytic proliferative disorder, which we considered LPL/WM. Multiple chromosomal or genetic changes were detected in bone marrow mononuclear cells, including ATM deletion, CCND1 amplification, mutations of MYD88 (L265P) and TP53, WT1 overexpression, and fusion gene of BIRC2-ARAP1, as well as complex chromosomal abnormalities. The patient refused chemotherapy because of old age and died of pneumonia 1 mo after the final diagnosis. CONCLUSION: The coexistence of DLBCL, AML, and untreated LPL/WM in the same patient is extremely rare, which probably results from multiple steps of genetic abnormalities. Asymptomatic LPL/WM might have occurred first, then myelodysplastic syndrome-related AML developed, and finally aggressive DLBCL arose. Therefore, medical staff should pay attention to this rare phenomenon to avoid misdiagnoses.

[Expression and Clinical Significance of Cytokines and Lymphocyte Subsets in Patients with Diffuse Large B-Cell Lymphoma].

OBJECTIVE: To study the role of cytokines and lymphocyte subsets in the diagnosis, prognosis and efficacy evaluation of DLBCL patients, and the effects of Tislelizumab on immune function and cytokines in DLBCL patients. METHODS: Twenty-three patients with newly diagnosed DLBCL were selected as DLBCL group and 34 patients with megaloblastic anemia as the control group. The levels of peripheral blood cytokines IL-2, IL-4, IL-6, IL-10, TNF- α and IFN-γ by ELISA method. The levels of peripheral blood CD3+, CD4+, CD8+ T lymphocytes, B lymphocytes and NK cells， the ratio of CD4+/CD8+ were detected by flow cytometry. The levels of cytokins and lymphocyto subsets in DLBCL patients with different clinical data and different therapeutic effects were compared. RESULTS: The levels of cytokines IL-2, IL-6 and IL-10 in DLBCL group were significantly higher than those in control group, but there was no significant correlation between cytokine levels and age and gender. The higher IPI score, higher Ann Arbor stage, B symptoms, higher ß 2-MG, LDH and CRP levels, IL-6 and IL-10 levels were significantly higher, and IL-4 was also significantly higher in patients with high LDH levels. Compared with the ineffective group, the levels of IL-6 and IL-10 were significantly lower and the level of CD4+ T cells and the ratio of CD4+/CD8+ was significantly higher in the effective group before therapy. The levels of IL-6, IL-10 and B lymphocytes in the effective group decreased significantly after therapy compared to those before therapy. After 4 cycles of therapy, the level of IL-2 and the ratio of CD4+/CD8+ in the Tislelizumab group were significantly higher than those in the non-Tislelizumab group, and the level of CD8+ T cells was significantly lower than that in the non-Tislelizumab group(P<0.05). The level of B lymphocytes in both the Tislelizumab group and the non-Tislelizumab group after therapy was significantly lower than that before therapy. CONCLUSION: The expression of cytokines and lymphocyte subsets in peripheral blood of patients with DLBCL is abnormal, which is related to the severity, prognosis and therapeutic effect of the disease. Tislelizumab can improve the immune function of patients with DLBCL by affecting cytokines and lymphocyte subsets and strengthen anti-tumor immunity.

Kellerin from Ferula sinkiangensis exerts neuroprotective effects after focal cerebral ischemia in rats by inhibiting microglia-mediated inflammatory responses.

ETHNOPHARMACOLOGICAL RELEVANCE: Ferula sinkiangensis K. M. Shen is a traditional Chinese medicine that has a variety of pharmacological properties relevant to neurological disorders and inflammations. Kellerin, a novel compound extracted from Ferula sinkiangensis, exerts a strong anti-neuroinflammatory effect by inhibiting microglial activation. Microglial activation plays a vital role in ischemia-induced brain injury. However, the potential therapeutic effect of kellerin on focal cerebral ischemia is still unknown. AIM OF THE STUDY: To explore the effect of kellerin on cerebral ischemia and clarify its possible mechanisms, we applied the middle cerebral artery occlusion (MCAO) model and the LPS-activated microglia model in our study. MATERIALS AND METHODS: Neurological outcome was examined according to a 4-tiered grading system. Brain infarct size was measured using TTC staining. Brain edema was calculated using the wet weight minus dry weight method. Neuron damage and microglial activation were observed by immunofluorescence in MCAO model in rats. In in vitro studies, microglial activation was examined by flow cytometry and the viability of neuronal cells cultured in microglia-conditioned medium was measured using MTT assay. The levels of pro-inflammatory cytokines were measured by qRT-PCR and ELISA. The proteins involved in NF-κB signaling pathway were determined by western blot. Intracellular ROS was examined using DCFH-DA method and NADPH oxidase activity was measured using the NBT assay. RESULTS: We found that kellerin improved neurological outcome, reduced brain infarct size and decreased brain edema in MCAO model in rats. Under the pathologic conditions of focal cerebral ischemia, kellerin alleviated neuron damage and inhibited microglial activation. Moreover, in in vitro studies of LPS-stimulated BV2 cells kellerin protected neuronal cells from being damaged by inhibiting microglial activation. Kellerin also reduced the levels of pro-inflammatory cytokines, suppressed the NF-κB signaling pathway, and decreased ROS generation and NADPH oxidase activity. CONCLUSIONS: Our discoveries reveal that the neuroprotective effects of kellerin may largely depend on its inhibitory effect on microglial activation. This suggests that kellerin could serve as a novel anti-inflammatory agent which may have therapeutic effects in ischemic stroke.

Ketogenic Diet Suppressed T-Regulatory Cells and Promoted Cardiac Fibrosis via Reducing Mitochondria-Associated Membranes and Inhibiting Mitochondrial Function.

Ketogenic diet (KD) is popular in diabetic patients but its cardiac safety and efficiency on the heart are unknown. The aim of the present study is to determine the effects and the underlined mechanisms of KD on cardiac function in diabetic cardiomyopathy (DCM). We used db/db mice to model DCM, and different diets (regular or KD) were used. Cardiac function and interstitial fibrosis were determined. T-regulatory cell (Treg) number and functions were evaluated. The effects of ketone body (KB) on fatty acid (FA) and glucose metabolism, mitochondria-associated endoplasmic reticulum membranes (MAMs), and mitochondrial respiration were assessed. The mechanisms via which KB regulated MAMs and Tregs were addressed. KD improved metabolic indices in db/db mice. However, KD impaired cardiac diastolic function and exacerbated ventricular fibrosis. Proportions of circulatory CD4+CD25+Foxp3+ cells in whole blood cells and serum levels of IL-4 and IL-10 were reduced in mice fed with KD. KB suppressed the differentiation to Tregs from naive CD4+ T cells. Cultured medium from KB-treated Tregs synergically activated cardiac fibroblasts. Meanwhile, KB inhibited Treg proliferation and productions of IL-4 and IL-10. Treg MAMs, mitochondrial respiration and respiratory complexes, and FA synthesis and oxidation were all suppressed by KB while glycolytic levels were increased. L-carnitine reversed Treg proliferation and function inhibited by KB. Proportions of ST2L+ cells in Tregs were reduced by KB, as well as the production of ST2L ligand, IL-33. Reinforcement expressions of ST2L in Tregs counteracted the reductions in MAMs, mitochondrial respiration, and Treg proliferations and productions of Treg cytokines IL-4 and IL-10. Therefore, despite the improvement of metabolic indices, KD impaired Treg expansion and function and promoted cardiac fibroblast activation and interstitial fibrosis. This could be mainly mediated by the suppression of MAMs and fatty acid metabolism inhibition via blunting IL-33/ST2L signaling.

Combined Rosiglitazone and Forskolin Have Neuroprotective Effects in SD Rats after Spinal Cord Injury.

The peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist rosiglitazone inhibits NF-κB expression and endogenous neural stem cell differentiation into neurons and reduces the inflammatory cascade after spinal cord injury (SCI). The aim of this study was to explore the mechanisms underlying rosiglitazone-mediated neuroprotective effects and regulation of the balance between the inflammatory cascade and generation of endogenous spinal cord neurons by using a spinal cord-derived neural stem cell culture system as well as SD rat SCI model. Activation of PPAR-γ could promote neural stem cell proliferation and inhibit PKA expression and neuronal formation in vitro. In the SD rat SCI model, the rosiglitazone + forskolin group showed better locomotor recovery compared to the rosiglitazone and forskolin groups. MAP2 expression was higher in the rosiglitazone + forskolin group than in the rosiglitazone group, NF-κB expression was lower in the rosiglitazone + forskolin group than in the forskolin group, and NeuN expression was higher in the rosiglitazone + forskolin group than in the forskolin group. PPAR-γ activation likely inhibits NF-κB, thereby reducing the inflammatory cascade, and PKA activation likely promotes neuronal cell regeneration.

[Expression Level of S100A6 mRNA in MM and Its Clinical Significance].

OBJECTIVE: To investigate the expression level of S100A6 mRNA in MM and to its clinical significance, and to evaluate its significance. METHODS: The expression level of S100A6 mRNA in MM patients was determined by real time quantitative PCR(RQ-PCR), and its relationship with the clinical features and outcomes of patients was analyzed by statistic method. RESULTS: S100A6 mRNA was detected in 20 MM patients. Compared with normal persons, the S100A6 mRNA expression in MM patients was higher. In different groups, the S100A6 mRNA expression in MM patients of 3 stages was higer than that in patients of 1 and 2 stages. MM patients with higher S100A6 mRNA expression had poor prognosis and higer extramedullary metastasis rate. CONCLUSION: The high expression of S100A6 mRNA is associated with poor prognosis and may be a prognostic molecular marker of MM.

[Effect of free light chain ratio normalization after treatment on prognosis of patients with multiple myeloma].

This study was aimed to investigate the normalization of serum free light chain ratio (sPLCR) after treatment of multiple myeloma (MM) and its influence on the prognosis of MM patients. The clinical data of 42 patients with MM were analyzed retrospectively from January 2009 to November 2013 in out department. According to sPLCR consecutive normalization for more 4 weeks or not after treatment, the patients were classified in patients with mormalized sPLCR and patients with abnormalized sPLCR, then the influence of traditional prognostic factors of MM on sPLCR and effect of sPLCR on overall survival (OS) time of MM patients were analyzed. The results showed that the influence of age, ISS stage displayed statistical difference between sFLCR normalization group and abnormalization group, the age ≥ 65 years and ISS stage III negatively impacted on sFLCR normalization (P < 0.05). The response rates of patients with normalized sFLCR were as follows: CR - 60%, VGPR - 38.89%; PR - 28.57%; 17 patients (40.48%) with sFLCR normalization showed superior OS, as compared with patients with sPLCR abnormalization (P < 0.01). It is concluded that the sFLCR normalization is the independent prognostic factor for MM, suggesting that the MM patients with sPLCR normalization after treatment have superior prognosis.

[Myeloid/natural killer cell acute leukemia resembling acute promyelocytic leukemia].

In order to improve the recognition of myeloid/natural killer cell acute leukemia and to reduce misdiagnosis, one case of myeloid/natural killer cell acute leukemia resembling acute promyelocytic leukemia(APL) was reported and the related articles published were reviewed. A series of clinical tests, the morphologic and immunophenotypic analysis of leukemia cells, cytogenetic and molecular biological examinations were performed. The results indicated that the patient had anemia, thrombocytopenia and leucocytosis, but no evidence of lymphadenopathy and hepatosplenomegaly. The morphology of leukemia cells was similar to that of abnormal promyelocytic cells, especially the variant of M3 (M3v) leukemia cells. The leukemia cells expressed CD117, CD33, CD15, CD56 and cMPO, but did not express CD34, HLA-DR, CD13 and CD16. Abnormal cytogenetics with del (7) (q22q32) was found. Neither t(15;17) nor PML/RARα gene rearrangement was detected. The patient failed to show a differentiation-induction response to all-trans retinoic acid(ATRA). In conclusion, the myeloid/natural killer cell leukemia is extremely rare. It is very important to distinguish the disorder from APL/M3v. The patient with myeloid/natural kill cell acute leukemia should be treated with chemotherapy as acute myeloid leukemia.

[Apoptosis-inducing effect of annexin A2 on multiple myeloma cells and its related mechanisms].

This study was purposed to investigate the apoptosis-inducing effect of Annexin A2 gene (AnxA2) on multiple myeloma (MM) cells and its mechanisms. The human MM cell lines U266 and RPMI8226 were transfected by using siRNA targeting at AnxA2; the expressions of AnxA2 mRNA and protein in the siRNA-transfected cells were detected by real-time PCR and Western blot, respectively; the cell apoptosis was assayed by flow cytometry. The results showed that silencing AnxA2 gene by siRNA resulted in decreased expressions of AnxA2 gene and protein, increased apoptosis of U266 and RPMI8226 cell lines (P < 0.05), at the same time resulted in down-regulation of apoptosis-related gene expressions including p65NF-κB, IL-2, IL-6 (P < 0.05), and up-regulation of P53 gene expression (P < 0.05). It is concluded that the AnxA2 silence plays a promoting role in apoptosis of MM cell lines U266 and RPMI8226.

Rosiglitazone enhances the proliferation of neural progenitor cells and inhibits inflammation response after spinal cord injury.

It has been previously shown that peroxisome proliferators-activated receptor gamma (PPAR-γ) is beneficial for nervous system injury. In present study, we examined the effect of rosiglitazone, a PPAR-γ agonist, on spinal cord injury (SCI) in rats. SCI was induced by dropping a 10g weight rod at a height of 25mm. The animals were randomly divided into vehicle group, rosiglitazone treated group, and G3335 treated group. Locomotor function recovery was evaluated by the Basso-Beattie-Bresnahan locomotor rating scale (BBB scale), NF-κB expression and endogenous neural progenitor cells (NPCs) proliferation and differentiation was assessed by flow cytometry and immunohistochemistry. Compared with the vehicle groups, we found that the rosiglitazone could significantly ameliorate locomotor recovery, reduce NF-κB expression, and increase the proliferation of endogenous NPCs. when the PPAR-γ antagonist was use, these effects were abolished. However, neurons differentiating from endogenous NPCs were inhibited when PPAR-γ was activated. Our results suggest that the activation of PPAR-γ may be a potential alternative treatment for spinal cord injury.

[Angioimmunoblastic T-cell lymphoma with large granular lymphocytosis].

To improve the recognition of angioimmunoblastic T-cell lymphoma (AITL) and to reduce misdiagnosis, a case diagnosed as AITL with large granular lymphocytosis was reported and the related articles were reviewed. A series of clinical tests, pathologic examination and immunohistochemical test, TCR gene rearrangement detection by multiple PCR and assay of lymphocyte immunophenotypes were carried out. The results indicated that the patient was characterized by fever, skin rash, generalized lymphadenopathy, splenomegaly, pleural effusion, ascites, anemia and thrombocytopenia, increase of circulating large granular lymphocytes with CD3(-) and CD16(+), CD56(+) were detected, T-cell receptor γ-chain gene was rearranged. More large granular lymphocytes with abnormal mitosis were found in ascites. The histological and immunohistochemical changes observed by the lymph node biopsy were compatible with AITL, some cells of which were CD56-positive. In conclusion, AITL is characterized by aggressive progress and generally occurs in elderly patients, its clinical prognosis is poor, the large granular lymphocytosis may be an autoimmune response to the tumor cells or originate from tumor stem/progenitor cells.

[Antitumor effects of low-frequency ultrasound combined with adriamycin on human leukemia multidrug resistance cell line K562/A02].

BACKGROUND & OBJECTIVE: Researches have shown that ultrasound can enhance the sensitivity of tumor cells towards chemotherapy drugs, thus to inhibit cell proliferation. This study was to investigate the antitumor effect of low-frequency ultrasound combined with adriamycin on human leukemia multidrug resistance (MDR) cell line K562/A02. METHODS: K562/A02 cells were divided into four groups: blank control group, adriamycin group, ultrasound group, and adriamycin plus ultrasound group. The trypan blue dye exclusion assay and MTT assay were used to determine the viability and proliferation of K562/A02 cells, while Wright's stain and flow cytometry were used to determine the apoptosis and the concentration of adriamycin. The expression of P-glycoproteins (P-gp) was detected using immunocytochemistry. RESULTS: Ultrasound (20 kHz, 0.25 W/cm2, 60s) combined with adriamycin (7.5 microg/mL) induced more apoptosis of K562/A02 cells than adriamycin alone. Compared with the adriamycin group, ultrasound at a frequency of 20 kHz and an intensity of 0.5 W/cm2 exerted an acute killing effect on cells. Ultrasound increased the intracellular concentration of adriamycin and promoted apoptosis of K562/A02 cells, but did not change the expression of P-gp on the cell membrane. CONCLUSION: Ultrasound at a frequency of 20 kHz, an intensity of 0.25 W/cm2 and duration of 60s can enhance the killing effect of adriamycin on K562/A02 cells.

[Enhancement of reversing drug resistance of K562/A02 cells to adriamycin by ultrasound-induced cavitation].

This study was aimed to investigate the effects of low frequency and power ultrasound combined with adriamycin on apoptosis of drug-resistant leukemia cell line K562/A02 in vitro, to find out the parameters of optimal exposure, and to explore the possible mechanism reversing drug-resistance of K562/A02 cells. The K562/A02 cells in logarithmic growth phase were used in experiments. The experiments were divided into 4 groups: group control, group adriamycin (A02) alone, group ultrasound (US) alone and group A02+US. The trypan blue dye exclusion test and MTT assay were used to determine the cell viability; Wright's staining was used to detect the apoptosis; the flow cytometry was used to analyze the drug concentration, and the scanning electron microscopy was used to observe the changes of cell surface. The results showed that the significant differences in cell viability, intracellular adriamycin concentration and changes of cell membrane were found between ultrasound-treated and untreated cells in the presence of various concentration of adriamycin. The exposure to ultrasound at 20 kHZ, 0.25 W/cm2 for 60 seconds could obviously decrease LC50 of adriamycin to K562/A02 cells, while the exposure to ultrasound at 20 kHZ, 0.05 W/cm2 for 60 seconds could kill K562/A02 cells at once. After being treated by low frequency ultrasound, the small holes with diameter about 1-2 microm in the cell surface appeared. The ultrasound increased the adriamycin concentration in the cells, accelerated the formation of apoptotic bodies, and promoted apoptosis of adriamycin-resistant cells. It is concluded that the ultrasound at optimal parameters enhances inhibitory effect of adriamycin on drug-resistant cell line, thereby reverses drug-resistance of drug-resistant cell line through sound-hole effect in tumor cells resulting from ultrasound induced cavitation.