LncRNA DANCR promotes ATG7 expression to accelerate hepatocellular carcinoma cell proliferation and autophagy by sponging miR-222-3p.

OBJECTIVE: LncRNA differentiation antagonizing non-protein coding RNA (DANCR) is an oncogene in various malignant cancers, including hepatocellular carcinoma (HCC). Autophagy is an intracellular self-digestion mechanism that accelerates the progression of HCC via promoting cell survival. However, the role of lncRNA DANCR in HCC, and the mechanism of lncRNA DANCR in the regulation of autophagy in HCC remains unknown. Therefore, the aims of this study are the investigation of the role of lncRNA DANCR in HCC, and the exploration of the molecular mechanism of lncRNA DANCR in regulating autophagy of HCC cells. PATIENTS AND METHODS: In this study, the expression of lncRNA DANCR, miR-222-3p, and autophagy-related gene 7 (ATG7) was detected by qRT-PCR. The cell proliferation and colony formation were measured by Cell Counting Kit-8 (CCK-8) assay and colony formation assay. And the autophagic flux was evaluated by mRFP-GFP-LC3B reporter. The autophagy related proteins were analyzed by Western blotting. Besides, the relationship between lncRNA DANCR and miR-222-3p, as well as between miR-222-3p and ATG7, was determined by Dual-Luciferase reporter system. RESULTS: We found high expression of lncRNA DANCR and ATG7, and low expression of miR-222-3p in HCC tissues and cell lines. And lncRNA DANCR positively correlated with poor survival of HCC patients. Moreover, the knockdown of lncRNA DANCR inhibited cell proliferation and autophagy of HCC cells. And we predicted and proved that lncRNA DANCR induced cell proliferation, colony formation and autophagy by increasing ATG7 and suppressing miR-222-3p. CONCLUSIONS: Our study demonstrates the promoting role of lncRNA DANCR in HCC, and indicates the regulatory effects of lncRNA DANCR on regulating autophagy of HCC.

[Challenges and countermeasures in the treatment of luminal breast cancer].

Luminal breast cancer is the most common subtype of breast cancer, representing more than 60% of all breast cancers. Endocrine resistance and late recurrence are two challenges in the treatment of luminal breast cancer. To overcome endocrine resistance in multiple levels, high-dose-fulvestrant can inhibit estrogen-receptor (ER)-dependent pathways, while targeted drugs can block ER-independent pathways.To reduce the risk of late recurrence in luminal breast cancer, recurrence prediction model should be formed. For patients with high risk of late recurrence, extended endocrine therapy, combination of ovarian function suppression (OFS) or vascular endothelial growth factor (VEGF) inhibitor could be utilized. Based on the challenges of the treatment, scientific research achievements can be used in clinical practice, and finally optimize the clinical treatment strategy.

[Endoscopic reconstruction of the posterior nares for the treatment of 46 children with congenital posterior atresia].

Objective:The aim of this study is to explore the influencing factors of the posterior nostril re-atresia by analyzing the clinical data of endoscopic posterior nostril reconstruction in the children with posterior nostril atresia. Method:Retrospectively reviewed 46 pediatric patients with congenital choanal atresia who underwent endoscopic posterior nostril reconstruction. Randomly divided the cases into the atresia group（19 cases） and the non-atresia group（27 cases） according to whether the new posterior nostril re-atresia again. Compared the difference of the clinical data between the two groups and observed the influencing factors of the posterior nostril re-atresia. Result:The gender, age, unilateral/bilateral atresia or U-shaped stent had no significant differences between the two groups. However, the nature of the atresia and granulation hyperplasia were significant differences between the two groups. Further analysis of the nature of the atresia revealed osseous atresia had higher rate of re-atresia than membranous atresia. Conclusion:Endoscopic posterior nostril reconstruction was a good method for the treatment of the children with congenital posterior nostril atresia. However, the children with osseous atresia had higher re-atresia rate.

[MiR-222-3р Regulates the Proliferation and Differentiation of C2C12 Myoblasts by Targeting BTG2].

MiR-222-3р has been implicated in tumor cell proliferation and has an important role in the differentiation and maturation of myogenic cells. However, its role in skeletal myoblast proliferation is still unclear. In this study, we found that miR-222-3р expression increases initially and then decreases during C2C12 myoblast proliferation. Using synthetic miRNA mimics and inhibitors in gain- or loss-of-function experiments, we snowed that miR-222-3р overexpression in C2C12 cells promotes myoblast proliferation and represses myofiber formation, while miR-222-3р downregulation has the opposite effect. Using a prediction program, BTG2 was identified as a possible target gene of miR-222-3р. During myogenesis, miR-222-3р mimics repress BTG2 expression, while miR-222-3р inhibitors promote BTG2 expression. Using dual-luciferase reporter assay, we further demonstrated that miR-222-3р specifically targets BTG2. Additionally, we show that siRNA-mediated downregulation of BTG2 expression in C2C12 myoblasts promotes the proliferation and suppresses differentiation. In conclusion, we provide a novel insight into the mechanism by which miR-222-3р regulates the proliferation and differentiation of C2C12 myoblasts by targeting BTG2. This information contributes to our understanding of the role of miRNAs in skeletal muscle development.

[Effects of denatured collagen type â on differentiation of human fibroblasts into myofibroblasts].

Objective: To investigate the effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts. Methods: A small amount of normal skin donated by burn patients undergoing scar surgery was collected. Human fibroblasts were obtained by method of explant culture and then sub-cultured. The fourth passage of cells were used in the following experiments. (1) Fibroblasts were divided into normal collagen group and denatured collagen group according to the random number table, with 10 wells in each group. Fibroblasts in normal collagen group were cultured on normal collagen type Ⅰ coated coverslips. Fibroblasts in denatured collagen group were cultured on denatured type Ⅰ collagen coated coverslips. Expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemical method, and the percentage of PCNA positive cells was calculated. (2) Another batch of fibroblasts were grouped and treated as in (1), with 12 wells in each group. Proliferation activity of cells was determined with methyl-thiazolyl-tetrazolium colorimetry method. (3) Another batch of fibroblasts were grouped and treated as in (1), and the microfilament morphology of cells was observed by rhodamine-phalloidin staining. (4) Another batch of fibroblasts were grouped and treated as in (1). Expression of α smooth muscle actin (α-SMA) of cells was detected by immunohistochemical method, and expression of OB-cadherin of cells was detected by immunofluorescence method. (5) Another batch of fibroblasts were divided into normal collagen, denatured collagen, and common coverslips groups according to the random number table, with 6 wells in each group. Fibroblasts in normal collagen and denatured collagen groups were treated as in (1), while fibroblasts in common coverslips group were cultured on coverslips without collagen coating. Expressions of α-SMA and OB-cadherin of cells were determined with Western blotting. (6) Another batch of fibroblasts were grouped and treated as in (5), and then the mRNA expressions of collagen type Ⅰ, collagen type Ⅲ, and α-SMA of cells were determined with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with t test, one way analysis of variance, and least-significant difference test. Results: (1) The percentage of PCNA positive cells in denatured collagen group was (83±9)%, significantly higher than (29±9)% in normal collagen group (t=13.53, P<0.01). (2) The proliferation activity of fibroblasts in denatured collagen group was 0.32±0.06, significantly higher than 0.25±0.05 in normal collagen group (t=3.06, P<0.01). (3) The microfilament of fibroblasts in normal collagen group was arranged vertically and in parallel way, paralleling the long axis of cells. The microfilament of fibroblasts in denatured collagen group was denser and thicker. (4) Most fibroblasts in normal collagen group showed long shuttle-like shape typically. Morphology of fibroblasts in denatured collagen group changed, and cells were obviously spreading. Expressions of α-SMA and OB-cadherin of fibroblasts in denatured collagen group were stronger than those in normal collagen group. (5) Expressions of α-SMA of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 1.69±0.41, 0.89±0.27, and 1.46±0.42. Expression of α-SMA of fibroblasts in denatured collagen group was significantly higher than that in normal collagen group (P<0.01). Expressions of OB-cadherin of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 5.17±0.28, 2.21±0.10, and 4.01±0.56. Expression of OB-cadherin of fibroblasts in denatured group was significantly higher than that in normal collagen group (P<0.01). (6) There was no significant difference in mRNA expression of collagen type Ⅰ of fibroblasts in denatured collagen, normal collagen, and common coverslips groups (F=2.71, P>0.05). The mRNA expressions of collagen type Ⅲ and α-SMA of fibroblasts in normal collagen group were significantly lower than those in denatured collagen group (P<0.01). Conclusions: Denatured collagen type Ⅰ may influence the activity of fibroblasts, thus inducing fibroblasts differentiating into myofibroblasts.

Retrospective analysis of 20 cases of refractory Hodgkin's lymphoma.

We investigate the clinical characteristics, prognosis and treatment of relapsed and refractory Hodgkin's lymphoma. Twenty patients with relapsed and refractory Hodgkin lymphoma were treated by chemotherapy or autologous stem cell transplantation in our hospital from April 2006 to August 2012. The retrospective analysis of the records from the 20 patients reflected both 5-year overall survival (OS) and progression-free survival (PFS). The overall effectiveness was 80% for the 20 patients. The 5-year overall survival rate and 5-year progression-free survival rate were 73.5% and 62.7%, respectively. Therefore, comprehensive treatment should be actively utilized in the case of invalid second-line regimen for the refractory HL patients.

Circulating DNA for detection of gastric cancer.

OBJECTIVE: Gastric cancer (GC) is one of the most common malignant tumors worldwide, particularly, prevalent in China. Despite the decreasing incidence of GC in China, the 5-year survival rate is still not over 30% yet. Therefore, early diagnosis and therapeutic outcome evaluation of GC remains as the issue to be resolved in a clinical setting. MATERIALS AND METHODS: Recent studies have found the presence of a certain amount of circulating DNA in the peripheral blood of patients with malignant tumor and shown that these free DNA bear tumor-specific genetic information. The circulating DNA detection includes quantitative and qualitative methods and analysis. Combined monitoring of changes in circulating DNA levels and aberrant alteration of relevant tumor genes is likely to provide comprehensive real-time information to patients. RESULTS: Under normal conditions, oncogene presents in the form of proto-oncogene such as K-ras, which is in non-carcinogenic status under the influence of tumor suppressor gene. When tumor suppressor gene is damaged or mutated of oncogene itself is induced for instance P53, oncogene is then activated and induces tumorigenesis. However, compared to gene mutation detection, the detection of DNA methylation is relatively more well-developed and stable. CONCLUSIONS: This article reviews the current status of the research on circulating DNA in the diagnosis, assessment of response to therapy and prognostic evaluation in GC. In addition, the advantage, current issue and prospect of using circulating DNA as tumor marker are also analyzed.

Study on 256-slice spiral CT bronchial artery imaging of common pathological types of central-type lung cancer.

OBJECTIVE: In this study, we analyzed features of 256-slice spiral CT bronchial artery imaging in common pathological types of central-type lung cancer to provide a reference for clinical diagnosis. PATIENTS AND METHODS: 74 patients diagnosed as central-type lung cancer were selected. They included 34 cases of squamous carcinoma and 40 cases of non-squamous carcinoma. 256-slice spiral CT bronchial artery imaging examination was performed for patients in the two groups. The 3D reconstruction technique was used in a stand-alone workstation, using different rotation axis to observe space anatomical details of the bronchial artery and to compare development ratio of the bronchial artery, artery diameter, diameter of tumor and developing condition of the pulmonary artery. RESULTS: It was found that left side, right side and both sides developing ratios of a bronchial artery in the squamous carcinoma group were higher than the other group. Moreover, the average diameter of the artery and diameter of the tumor was significantly higher than non-squamous carcinoma group. The occurrence rates of compression and narrowing on the pulmonary arterial branch at tumor side were significantly increased (p<0.05). CONCLUSIONS: There were different 256-slice spiral CT bronchial artery imaging results for different pathological types of central-type lung cancer, which has a certain reference value for clinical diagnosis.

[Breast cancer research in the era of precision medicine].

Precision medicine is an emerging medical strategy that takes into account individual molecular variations of disease to guide accurate prevention and treatment.Tumor molecular markers closely related to aggressive behavior and treatment response will be identified by integrating clinical information and multiple-omics, and will be verified in well-designed clinical trials. Breast cancer is a highly heterogeneous disease. Its treatment based on molecular subtyping has achieved initial success. However, drug resistance and tumor heterogeneity are still major challenges. This review will focus on the recent progress and future prospects of clinical research on breast cancer in the era of precision medicine.

[Experience in children airway foreign bodies: an analysis of 220 cases].

Objective:To observe the clinical characteristics, pathogen infection and the diagnostic reliability of CT multiplanar reconstruction(CT MPR) in the children with airway foreign bodies.Method:We retrospectively reviewed 220 pediatric patients suspected with respiratory foreign bodies who were simultaneously examined by CT MPR, bronchoscopy and secretion culture.Then we summarized their characteristics from treatment process, age distribution, foreign body kinds, examination results of CT MPR, bronchoscopy and secretion culture. Result:Only 108 cases(49.09%) accepted bronchoscopy in 48 hours and the most risk age was 1 to 2 years old. We observed the commonest foreign bodies were peanuts, melon seeds and nuts. In addition, we found CT MPR was accurate in diagnostic airway foreign body with accuracy ratio was 94.09%. Furthermore, our secretion culture showed negative(64.09%) in 141 cases and positive(35.91%) in 79 patients. And the commonest pathogenic bacteria were staphylococcus aureus, streptococcus pneumoniae, haemophilus influenzae, pseudomonas aeruginosa,klebsiella pneumonia.Conclusion:Pediatric airway foreign bodies had its own clinical characteristics.When the medical units had no conditions to carry out bronchoscopy,CT MPR would be a good choice to rule out airway foreign body.Besides,most case only needed symptomatic treatment other than antibiotics after bronchoscopy.

Creation of experimental aneurysms at a surgically created arterial confluence.

OBJECTIVE: Complex vertebral confluence aneurysms remain clinically challenging despite the rapid technological advances in endovascular technology. Therefore, animal confluence aneurysm models are urgently needed for the preclinical development of related medical devices and training clinicians. This study aimed to establish canine confluence aneurysm model and evaluate hemodynamics in this model. MATERIALS AND METHODS: According to the shape and regional blood flow of vertebrobasilar junction (VBJ) aneurysms, confluence aneurysm was introduced in 9 dogs by microsurgical technique. We partially anastomosed right common carotid artery (CCA) and left CCA (end to side anastomosis) to create inverted Y-junction of arteries and, then, sutured a harvested segment of external jugular vein to the notch of anastomosis to simulate confluence aneurysm. These animals were examined by 3D digital subtraction angiography (DSA) 4 weeks after surgery. Geometry parameters of the aneurysm, surrounding vasculature and specific double inlet profiles were analyzed by simulating computational fluid dynamics (CFD) in these animals. RESULTS: Aneurysms were successfully established in all animals, including 8 complete and 1 partially thrombosed aneurysms. No neurological defects or death were observed. Geometric and hemodynamic parameters in these surgically introduced confluence aneurysm animals are similar to those reported for human VBJ aneurysms. CONCLUSIONS: This study documents a protocol to successfully establish confluence aneurysm models in dogs. This model may be useful in preclinical studies targeting various complex vertebral confluence aneurysms.

Effects of muscle fiber type on glycolytic potential and meat quality traits in different Tibetan pig muscles and their association with glycolysis-related gene expression.

The myosin heavy chain (MyHC) composition, glycolytic potential, mitochondrial content, and gene expression related to energy metabolism were analyzed in eight muscles from Tibetan pigs, to study how meat quality develops in different muscle tissues. The muscles were classified into three clusters, based on MyHC composition: masseter, trapezius, and latissimus dorsi as 'slow-oxidative-type'; psoas major and semimembranosus as 'intermediate-type'; and longissimus dorsi, obliquus externus abdominis, and semitendinosus as 'fast-glycolytic-type'. The 'slow-oxidative-type' muscles had the highest MyHC I and MyHC IIA content (P < 0.01); 'intermediate-type' muscles, the highest MyHC IIx content (P < 0.01); and 'fast-glycolytic-type' muscles, the highest MyHC IIb content (P < 0.01). The pH values measured in 'slow-oxidative-type' muscles were higher than those in the other clusters were; however, the color of 'fast-glycolytic-type' muscles was palest (P < 0.01). Mitochondrial content increased in the order: fast-glycolytic-type < intermediate-type < slow-oxidative-type. In the 'slow-oxidative-type' muscles, the expression levels of genes related to ATP synthesis were higher, but were lower for those related to glycogen synthesis and glycolysis. Mitochondrial content was significantly positively correlated with MyHC I content, but negatively correlated with MyHC IIb content. MyHC I and mitochondrial content were both negatively correlated with glycolytic potential. Overall, muscles used frequently in exercise had a higher proportion of type I fibers. 'Slow-oxidative-type' muscles, rich in type I fibers with higher mitochondrial and lower glycogen and glucose contents, had a higher ATP synthesis efficiency and lower glycolytic capacity, which contributed to their superior meat quality.

Hypoxia enhances FGF2- and VEGF-stimulated human placental artery endothelial cell proliferation: roles of MEK1/2/ERK1/2 and PI3K/AKT1 pathways.

Placental development occurs under a low oxygen (2-8% O(2)) environment, which is critical for placental development and angiogenesis. In this study, we examined if hypoxia affected fibroblast growth factor-2 (FGF2)- and vascular endothelial growth factor (VEGF)-stimulated cell proliferation via the mitogen-activated protein kinase kinase 1/2 (MEK1/2)/extracellular signal-regulated kinases 1/2 (ERK1/2) and phosphatidylinositol-3 kinase (PI3K)/v-akt murine thymomaviral oncogene homologue (AKT1) pathways in human placental artery endothelial (HPAE) cells. We observed that under normoxia (approximately 20% O(2)), FGF2 and VEGF dose-dependently stimulated cell proliferation. Hypoxia (3% O(2)) significantly promoted FGF2- and VEGF-stimulated cell proliferation as compared to normoxia. Under both normoxia and hypoxia, FGF2 rapidly induced ERK1/2 and AKT1 phosphorylation, while VEGF-induced ERK1/2, but not AKT1 phosphorylation. However, hypoxia did not significantly alter FGF2- and VEGF-induced ERK1/2 and AKT1 phosphorylation as compared to normoxia. PD98059 (a MEK1/2 inhibitor) at 20microM and LY294002 (a PI3K inhibitor) at 5microM attenuated FGF2- and VEGF-induced phosphorylation of ERK1/2 and AKT1, respectively. PD98059, even at doses that drastically inhibited FGF2-induced ERK1/2 phosphorylation (20microM) and caused cell loss (40microM), did not affect FGF2-stimulated cell proliferation, which was confirmed by U0126 (another potent MEK1/2 inhibitor). PD98059, however, dose-dependently inhibited VEGF-stimulated cell proliferation. Conversely, LY294002 dose-dependently inhibited FGF2-, but not VEGF-stimulated cell proliferation. These data suggest that in the MEK1/2/ERK1/2 and PI3K/AKT1 pathways differentially mediate FGF2- and VEGF-stimulated HPAE cell proliferation. These results also indicate that hypoxia promotes FGF2- and VEGF-stimulated cell proliferation without further activation of the PI3K/AKT1 and MEK1/2/ERK1/2, respectively.

Identification of a novel HLA-DRB1 allele (HLA-DRB1*111902*).

In this paper, we report a new HLA-DRB1 allele identified in a male acute myeloid leukaemia Chinese patient. This sample was initially typed as DRB1*11XX using commercial polymerase chain reaction-sequence-specific primers kit. When it was typed using a chip-based sequence-specific oligonucleotide technique, a novel hybridization pattern that does not match any known alleles was observed. Through sequencing, we have identified this allele as a new HLA-DRB1 allele, which was later named HLA-DRB1*111902 by the WHO Nomenclature Committee. The sequence of this new allele differs from DRB1*111901 by one nucleotide (from G to C) at 203nt of exon 2 but does not cause any amino acid substitution.

Human G-CSF-mobilized CD34-positive peripheral blood progenitor cells can stimulate allogeneic T-cell responses: implications for graft rejection in mismatched transplantation.

To investigate mechanisms of stem cell graft rejection we studied the allo-stimulatory potential of G-CSF mobilized peripheral blood progenitor cells (PBPC). CD34+ cells were purified (>95%) in a two-step procedure using immunoaffinity columns for CD34 selection and T-depletion. The capacity of CD34+ cells to stimulate allogeneic T-cell responses was compared with other cells from the same individual. CD34+ cells induced potent proliferative responses at stimulator:responder ratios of 1:20, but were approximately 50-fold less efficient compared to dendritic cells. Furthermore, CD34+ cells primed responses from partially matched allogeneic T cells in bulk cultures. Dual-colour flow cytometry showed that the co-stimulatory molecules B7.1, CD40 and ICAM-1 were absent on resting CD34-positive progenitor cells, but were induced during incubation with allogeneic lymphocytes due to a cytokine-mediated effect. Up-regulation of accessory molecules on CD34+ cells was reproduced by incubation with interferon-gamma or GM-CSF which enhanced the allo-stimulatory activity of CD34+ cells. Blocking studies with inhibitory antibodies suggested co-stimulatory functions for B7.2, ICAM-3, CD40 and LFA-3. CD34+ cells were more efficient in inducing allogeneic T-cell responses when compared to the unprocessed leukapheresis products. The reduced allo-stimulatory ability of G-CSF mobilized PBPC could be explained by the presence of CD3+ 4+ and CD3+ 8+ lymphocytes with suppressor activity. We conclude that current methods of stem cell selection for transplantation do not avoid allosensitization of the recipient and that further graft manipulation with add-back of lymphocytes or selection of subsets of CD34+ cells with reduced allo-stimulatory ability may reduce graft rejection.

A technique for dual determination of cytotoxic and helper lymphocyte precursor frequency by a miniaturized dye release method.

Helper (HTLPf) and cytotoxic (CTLPf) lymphocyte precursor frequency assays are increasingly used in bone marrow stem cell and organ transplant compatibility testing. Current techniques require large cell numbers and radioisotopes. To improve the technique, we developed a miniaturized fluorescent read-out combined HTLPf/CTLPf limiting dilution assay. The assay requires only 5 x 10(6) stimulators, 2 x 10(6) responders and 0.24 x 10(6) target cells in Terasaki plates (40 microl/well). For the HTLPf, culture supernatants from each well were assayed for IL-2 production. The IL-2-dependent proliferation of the mouse 9.12 cell line was detected by a semi-automated fluorescent dye technique. After addition of rhIL-2 (recombinant human IL-2) on days 3 and 7, CTLPs were detected on day 10 by measuring the lysis of dye-labeled targets. Results were comparable to standard radioisotope-based techniques. The assay had a coefficient of variation of approximately 30%. The assay detected helper CD4 cells, pure cytotoxic CD8, helper CD8 cells and helper/cytotoxic CD8 cells. Discrimination was demonstrated between HLA-matched related and non-related pairs. The ease of testing and small cell numbers required should facilitate further evaluation of HTLPf and CTLPf for compatibility testing in unrelated donor transplantation and monitoring immune responses following adoptive transfer of lymphocytes.

Haematological response of patients with myelodysplastic syndrome to antithymocyte globulin is associated with a loss of lymphocyte-mediated inhibition of CFU-GM and alterations in T-cell receptor Vbeta profiles.

We have demonstrated that 44% of myelodysplastic syndrome (MDS) patients with cytopenia have a haematological response to antithymocyte globulin (ATG). Three ATG responders and two non-responders with refractory anaemia were further studied for lymphocyte-mediated inhibition of bone marrow using a standard CFU-GM assay. In responders, peripheral blood lymphocytes (PBL) added at a 5:1 ratio suppressed CFU-GM by 54+/-9% (P=0.04) and was reversed by ATG treatment. Pre-treatment marrow depleted of CD3 lymphocytes, increased CFU-GM by 32% (P=0.02) in an ATG responder, but not in a non-responder. CD3 lymphocytes from 6-month post-treatment marrow did not inhibit pre-treatment CFU-GM, indicating ATG had affected the T cells. Pre-treatment marrow depleted of CD8 lymphocytes, increased CFU-GM by 60% (P=0.01) and 49% (P=0.03) in two ATG responders, but not in a non-responder. Inhibition required cell-cell interaction through MHCI. TCRVbeta families, analysed by SSCP, changed from clonal to polyclonal in one ATG responder after 6 months, but clones persisted in a non-responder. These results indicate patients with refractory anaemia who respond to ATG have CD8 T-cell clones that mediate MHCI-restricted suppression of CFU-GM which are replaced by polyclonal T cells that do not suppress CFU-GM after ATG treatment.

Specific depletion of alloreactive T cells in HLA-identical siblings: a method for separating graft-versus-host and graft-versus-leukaemia reactions.

Accumulating evidence indicates that alloreactive donor T cells confer both graft-versus-host (GVH) and graft-versus-leukaemia (GVL) reactivity following allogeneic bone marrow transplantation. We have developed a method to deplete alloreactive donor T cells with an immunotoxin targeting the alpha chain of the IL-2 receptor. In patients with chronic myeloid leukaemia and their HLA-identical sibling donors, we measured donor helper T-lymphocyte precursor frequencies (HTLPf) against recipient peripheral blood mononuclear cells (PBMNC; donor versus host), recipient leukaemia cells (donor versus leukaemia) and third-party PBMNC, before and after the depletion. In seven pairs there was a 4.3-fold reduction of donor-versus-host HTLPf (P=0.017), without a significant change in the donor frequencies against third party (P=0.96). In eight further donor-recipient pairs, immunotoxin-depleted donor versus patient PBMNC HTLPf 4.5-fold (mean 1/155,000 before and 1/839,000 after depletion, P=0.007). There was a smaller non-significant 1.8-fold reduction in donor-versus-leukaemia HTLPf from 1/192,000 to 1/334,000 (P=0.19). These results suggest that selective T-cell depletion can significantly deplete donor anti-host reactivity while conserving anti-leukaemia reactivity in HLA-matched donor-recipient pairs.

Transfection of interleukin-12 cDNAs into tumor cells induces cytotoxic immune responses against native tumor: implications for tumor vaccination.

Interleukin-12 (IL-12) is a heterodimeric cytokine that is central to the development of T helper 1-dependent cellular immunity. Although this cytokine has potential therapeutic application as an antineoplastic agent, the systemic infusion of IL-12 has led to toxic fatalities; hence, restriction of expression of IL-12 to the microenvironment of target tumor cells has obvious appeal. In this study, we examined whether tumor cells that were liposome-transfected with IL-12 could enhance the induction of cytolytic lymphocyte immunity to the native tumor. The plasmid expression vector that we used has several useful features including replication to high copy number as an episome and a polycistronic message enabling the production of both the p35 and p40 subunits of IL-12 without alternative splicing; up to 3 ng/mL/10(6)/48 hours of IL-12 was produced following transfection. Tumor cells transfected with IL-12 were superior to untransfected cells in the induction of lymphocyte-mediated cytolysis. IL-12 transfectants induced a heterogeneous population of natural killer, lymphokine activated killer, and cytolytic T lymphocytes, the latter of which exhibited tumor-specific activity. Our studies suggest that liposome-mediated transfection of tumor cells with an episomal, high copy number plasmid vector expressing both IL-12 subunits is a promising approach to cancer vaccination, a strategy that could be implemented ex vivo in treating malignancies such as metastatic ovarian cancer.