Tspan8 is expressed in breast cancer and regulates E-cadherin/catenin signalling and metastasis accompanied by increased circulating extracellular vesicles

Tspan8 exhibits a functional role in many cancer types including pancreatic, colorectal, oesophagus carcinoma, and melanoma. We present a first study on the expression and function of Tspan8 in breast cancer. Tspan8 protein was present in the majority of human primary breast cancer lesions and metastases in the brain, bone, lung, and liver. In a syngeneic rat breast cancer model, Tspan8⁺ tumours formed multiple liver and spleen metastases, while Tspan8⁻ tumours exhibited a significantly diminished ability to metastasise, indicating a role of Tspan8 in metastases. Addressing the underlying molecular mechanisms, we discovered that Tspan8 can mediate up-regulation of E-cadherin and down-regulation of Twist, p120-catenin, and β-catenin target genes accompanied by the change of cell phenotype, resembling the mesenchymal–epithelial transition. Furthermore, Tspan8⁺ cells exhibited enhanced cell–cell adhesion, diminished motility, and decreased sensitivity to irradiation. As a regulator of the content and function of extracellular vesicles (EVs), Tspan8 mediated a several-fold increase in EV number in cell culture and the circulation of tumour-bearing animals. We observed increased protein levels of E-cadherin and p120-catenin in these EVs; furthermore, Tspan8 and p120-catenin were co-immunoprecipitated, indicating that they may interact with each other. Altogether, our findings show the presence of Tspan8 in breast cancer primary lesion and metastases and indicate its role as a regulator of cell behaviour and EV release in breast cancer. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

Polymorphism of the thiopurine S-methyltransferase gene in African- Americans

The molecular basis for the genetic polymorphism of thiopurine S - methyltransferase (TPMT) has been estab-lished for Caucasians, but it remains to be elucidated in African populations. In the current study, we determined TPMT genotypes in a population of 248 African-Americans and compared it with allele frequencies in 282 Caucasian Americans. TPMT genotype was determined in all individuals with TPMT activity indicative of a heterozygous genotype (</=10.1 U/ml pRBC, n = 23African- Americans, n = 21 Caucasians) and a control group with TPMT activity indicative of a homozygous wild-type genotype (>10.2 U/ml pRBC, n = 23 African-Americans, n = 21 Caucasians). No mutant alleles were found in the high activity control groups. The overall mutant allele frequencies were similar in African-Americans and Caucasians (4.6 and 3.7% of alleles, respectively). However, while TPMT*3C was the most prevalent mutant allele in African-Americans (52.2% of mutant alleles), it represented only 4.8% of mutant alleles in Caucasians ( P < 0.001). In contrast, TPMT*3A and TPMT*2 were less common in African-Americans (17.4 and 8.7% of mutant alleles), whereas TPMT*3A was the most prevalent mutant allele in Caucasians (85.7% of mutant alleles). A novel allele ( TPMT*8 ), containing a single nucleotide transition (G644A), leading to an amino acid change at codon 215 (Arg-->His), was found in one African-American with intermediate activity. These data indicate that the same TPMT mutant alleles are found in American black and white populations, but that the predominant mutant alleles differ in these two ethnic groups.      

硝苯吡啶与格列本脲相互作用对正常大鼠和高血糖大鼠血糖水平的影响

目的 :研究硝苯吡啶以及硝苯吡啶与格列本脲合用对空腹大鼠和肾上腺素诱发高血糖大鼠血糖水平的影响。方法 :本实验采用葡萄糖氧化酶法测定血糖含量。结果 :硝苯吡啶 2 .5mg/kgig使空腹大鼠血糖水平显著升高(P <0 .0 1 ) ,并加重肾上腺素诱发的高血糖反应。而硝苯吡啶与降糖药格列本脲 0 .9mg/kg合用时不影响空腹大鼠的血糖水平 ,硝苯吡啶对肾上腺素诱发高血糖大鼠灌胃格列本脲后的降血糖作用亦无明显影响。结论 :尽管硝苯吡啶对空腹大鼠以及肾上腺素诱发高血糖大鼠有显著升高血糖的作用 ,但对格列本脲的降血糖作用无明显不良影响     

HPLC法同时测定注射用甲氧异腈中FSA和MIBI的含量

目的 :采用RP HPLC法同时测定了注射用甲氧异腈中两种主要成份二氧硫脲 (FSA)和四 (甲氧基异丁基异腈 )络铜 (I)氟硼酸盐 (MIBI)的含量。方法 :以甲醇、磷酸二氢铵 ( 80∶2 0 )为流动相 ,检测波长 2 1 5nm ,HPLC法测定含量。结果 :试验表明 ,FSA和MIBI在 2 5～ 1 2 5μg/ml,50～ 2 50 μg/ml范围内呈良好的线性关系 ,回归方程分别为Y =0 .2 3 0 .0 2X(r =0 .994 6) ,Y =-2 .1 9 0 .0 3X(r =0 .9998) ,相对标准偏差分别为 1 .2 5%和 0 .4 2 %。结论 :该方法简便、准确、可靠     

动脉功能不全与溃疡的诊断与治疗选择

多种全身疾病可以导致下肢溃疡,其中最常见的原因是诸如周围动脉和静脉的血管疾病。周围动脉疾病是一种进展缓慢的、隐匿的疾病进程,在美国大约800万~1 200万人受累于此病,而且每年的发病率还在不断增长。有20%的65岁以上的美国人患有周围动脉疾病,其中只有25%的人接受治疗。据估计,1 050万该病患者有症状,而另外1 650万的该病患者则无症状。有研究结果报道下肢溃疡的发病率为0·12%~1·8%。由于病人及初级治疗提供者不清楚周围动脉疾病的早期表现,并且几乎没有治疗方面的知识,因此常常不能做出正确诊断。动脉溃疡的病理生理学动脉血供不足…     

High Expression of Cathepsin D in Non-Hodgkin’s Lymphomas Negatively Impacts on Clinical Outcome

The lysosomal protease Cathepsin D (CD) has been implicated in the homeostasis of lymphatic tissues. We investigated whether the level of CD expression influences the progression and the clinical outcome in Non-Hodgkin’s Lymphomas (NHLs). The expression of CD was assessed by immunohistochemistry and immunofluorescence in biopsies of Diffuse Large B Cell Lymphomas (DLBCL, 35 cases), Follicular Lymphomas (FL, 9 cases of grade I-II plus 14 cases of grade IIIB), Chronic Lymphocytic Leukaemias (CLL, 17 cases) and Peripheral T-cell Lymphomas (PTCL, 5 cases). CD staining showed a cytoplasmic punctate pattern compatible with its lysosomal localization. Based on the level of CD expression and the proportion of positive cells, lymphomas were classified as ‘low expressing’ (< 20% of tumor cells) or ‘highly expressing’ (≥ 20% of tumor cells). Lymphomas highly expressing CD were associated with a worse stage (III-IV) at diagnosis (31/34 cases; p = 0.002) and with a poor clinical outcome (i.e., partial remission and death; 28/34 cases; p = 0.03). In the subgroup of aggressive/high grade of malignancy lymphomas (i.e., DLBCL, FL IIIB and PTCL), the Kaplan-Meier curve revealed a very low cumulative overall survival probability (~20% at 5 year) for patients bearing a NHL with > 40% CD-positive cells compared to that of patients bearing a NHL with < 20% CD-positive cells (~70% at 5 year). This correlation was statistically significant (log-rank test, p = 0.01). In Cox multivariate analysis CD failed to be a prognosticator independent of pathologic stage, though the hazard ratio confirmed the association of low expression with a better survival probability. These data indicate that the presence of a high percentage of CD-positive tumor cells negatively reflects on the progression of NHLs.     

Bile acids regulate intestinal antigen presentation and reduce graft-versus-host disease without impairing the graft-versus-leukemia effect

Acute graft-versus-host disease (GvHD) causes significant mortality in patients undergoing allogeneic hematopoietic cell transplantation. Immunosuppressive treatment for GvHD can impair the beneficial graft-versus-leukemia effect and facilitate malignancy relapse. Therefore, novel approaches that protect and regenerate injured tissues without impeding the donor immune system are needed. Bile acids regulate multiple cellular processes and are in close contact with the intestinal epithelium, a major target of acute GvHD. Here, we found that the bile acid pool is reduced following GvHD induction in a preclinical model. We evaluated the efficacy of bile acids to protect the intestinal epithelium without reducing anti-tumor immunity. We observed that application of bile acids decreased cytokine-induced cell death in intestinal organoids and cell lines. Systemic prophylactic administration of tauroursodeoxycholic acid (TUDCA), the most potent compound in our in vitro studies, reduced GvHD severity in three different murine transplantation models. This effect was mediated by decreased activity of the antigen presentation machinery and subsequent prevention of apoptosis of the intestinal epithelium. Moreover, bile acid administration did not alter the bacterial composition in the intestine suggesting that its effects are cell-specific and independent of the microbiome. Treatment of human and murine leukemic cell lines with TUDCA did not interfere with the expression of antigen presentation-related molecules. Systemic T-cell expansion and especially their cytotoxic capacity against leukemic cells remained intact. This study establishes a role for bile acids in the prevention of acute GvHD without impairing the graft-versus-leukemia effect. In particular, we provide a scientific rationale for the systematic use of TUDCA in patients undergoing allogeneic hematopoietic cell transplantation.