A variant of the HL-60 cell line expressing a high level of PTP1C exhibits increased susceptibility to differentiation by phorbol 12-myristate 13-acetate

A variant of the HL-60 cell line, HL-60/MCSFR4D2, has been found to express twice the amount of PTP1C as compared to the parental HL-60 cell line by immunoblotting and immunoprecipitation. Differentiation of the variant cells after phorbol 12-myristate 13-acetate (PMA) treatment was examined by the appearance of adherence. In 1% fetal calf serum (FCS), 20% of HL-60/MCSFR4D2 cells exhibited adherence after treatment with 0.5 ng/ml PMA for 48 h, 60% exhibited adherence after treatment with 1.0 ng/ml PMA and 80% exhibited adherence after treatment with 5.0 ng/ml PMA, while HL-60 cells exhibited only a slight response. Furthermore, antisense PTP1C oligonucleotides decreased the PMA-induced adherence of HL-60/MCSFR4D2 cells. These results suggest that the high-expression of PTP1C in HL-60 cells may be involved in the enhancement of susceptibility to macrophage-like differentiation by PMA.     

pp60c-src encoded by the proto-oncogene c-src is a product of sensory neurons

The advent of recombinant DNA technology has led to the identification in the DNA of normal animal cells of over 30 proto-oncogenes that are homologous to retroviral transforming genes. One of these encodes a protein kinase (pp60c-src) of unknown function, that is preferentially synthesized in brain and neural retina. Here the expression of pp60c-src in the peripheral nervous system was examined in sensory neurons from chick dorsal root ganglia with antisera raised against the transforming protein of Rous sarcoma virus (pp60v-src) expressed in Escherichia coli carrying the cloned v-src gene. This antiserum recognizes pp60c-src specifically in normal chicken cells. Western immunoblotting showed that dorsal root ganglia of stage 30 (day 6.5) chick embryos contained elevated levels of pp60c-src. Immunoperoxidase staining of neuron-enriched cultures prepared from chick dorsal root ganglia showed pp60c-src immunoreactivity in cells with neuronal morphology; flat, fibroblastic cells contained no detectable immunoreactivity. Indirect double immunofluorescence with pp60src antibodies and monoclonal antibodies against the 200-kD subunit of neurofilament protein confirmed that the cells expressing pp60c-src were neurons. Ninety-six percent of the neurofilament-positive cells were immunoreactive with pp60src antibodies, and conversely, all pp60c-src-positive cells were immunoreactive with neurofilament antibodies. pp60c-src immunofluorescence appeared to be distributed over the cell body, processes, and growth cones. These results clearly demonstrate that pp60c-src is a product of neurons and is expressed in sensory neurons in culture.     

氮芥抗药性人早幼粒白血病HL60细胞亚系的建立及其生物特性

用逐步递增药物浓度和软琼脂细胞克隆技术，药物连续作用１４个月后获得氮芥（ＨＮ２）抗药性人早幼粒白血病ＨＬ６０细胞亚系，抗件达５～７倍（ＨＬ６０／ＮＨ２６），在无ＨＮ２培养液中５倍以上抗性维持１０个月以上，抗性细胞亚系的生物学特性除倍增时间稍长和克隆形成率略低外其生长曲线，细胞周期细胞ＤＮＡ指数，形态学，组织化学和染色体分析均与亲代细胞相似。     

25-Hydroxyvitamin D3 metabolism in a human leukemia cell line

Summary 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) is a potent inducer of monocytic differentiation of the human promyelocytic leukemia cell line, HL-60. We have noted that 25-hydroxyvitamin D₃ (25(OH)D₃) in high doses is also capable of promoting monocytic differentiation of this cell line. To test the possibility that the latter activity is due to conversion of 25OHD₃ to 1,25(OH)₂D₃ by HL-60, we exposed HL-60 cells to 25OHD₃ and analyzed the products by HPLC and radioreceptor assay. When chromatographed in the traditional solvent system (isopropanol-hexane), a new peak appears which migrates with authentic 1,25(OH)₂D₃. However, in a solvent system containing dichloromethane, 90% of the peak migrates with another metabolite, 19-Nor-10-Keto-25OHD₃ (19-Nor-25OHD₃). Production of this metabolite is enhanced by living cells and is synthesized by both virgin HL-60 and those which have undergone differentiation. We next determined if authentic 19-Nor-25OHD₃ also promotes differentiation of this cell. As assessed by appearance of the monocyte-specific surface antigen (63D3) and macrophage-specific esterase activity, we find that this metabolite does, in fact, induce monocytic differentiation of HL-60 with a potency of approximately 1/200 that of 1,25(OH)₂D₃ and similar to that of 25OHD₃. In agreement with the effect upon cell maturation, 19-Nor-25OHD₃ displaces³H-1,25(OH)₂D₃ from its HL-60 receptor with an efficiency comparable to 25OHD₃. Hence, HL-60 cells convert 25OHD₃ to 19-Nor-25OHD₃, and 19-Nor-25OHD₃ induces monocytic differentiation of HL-60 with comparable efficiency to its precursor, 25OHD₃.     

几种抗癌药对HL—60细胞在小鼠肾囊膜下生长的抑制作用

以纤维蛋白凝块为HL-60细胞支持物,将其接种于正常和免疫抑制小鼠肾囊膜下,观察其增殖特性和生长特点。结果HL-60细胞纤维蛋白凝块在免疫排斥反应出现前的正常小鼠肾囊膜下,体积增殖5倍左右;在免疫抑制小鼠肾囊膜下,增殖15倍左右。组织切片发现,在肾囊膜下生长6d细胞密度明显增加,生长细胞沿肾囊膜向四周侵润,肿瘤细胞切面面积明显扩大,且生长细胞仍保持HL-60细胞的形态特点。维甲酸(RA)、维胺酸(RⅡ)及三尖杉酯碱等药物可明显抑制HL-60细胞的生长。     

Identification and characterization of a DR4-restricted T cell epitope within chlamydia heat shock protein 60

An epitope within the 60 kD Chlamydia trachomatis heat shock protein (hsp) 60, recognized by a HLA-DRB1*0401-restricted T cell clone from a reactive arthritis patient, has been characterized. Stimulatory peptides contained a nine amino acid sequence (residues 38–46) predicted by algorithm to confer strong binding to DRB1*0401, with valine in the P1 position. The overall length of the peptide was critical for efficient recognition; peptides with at least one residue N-terminal to the putative P1 position were markedly more stimulatory than a peptide whose N-terminal is the P1 valine. Optimal responses were seen with 14mer peptides having two to three amino acids N- and C-terminal to the core 9mer. The sequence of the defined epitope is identical in hsp60 from both C. trachomatis and C. pneumoniae. Since the latter is a common respiratory pathogen, patients infected with C. trachomatis may already be primed for responses to hsp60 by prior infection with C. pneumoniae. Such secondary responses are important in the pathogenesis of chlamydia-induced inflammatory diseases such as trachoma. Priming by infection with enteric organisms was considered because of the similarity of the epitope sequence in Escherichia coli hsp60. However, although an E. coli-related peptide was recognized, intact E. coli hsp60 was not, suggesting that the epitope is cryptic in E. coli hsp60. Human hsp60 has six amino acid differences from chlamydial hsp60 in the epitope sequence and was not recognized. Thus cross-reactive recognition of self hsp60 could not be implicated in the pathogenesis of chlamydia-induced reactive arthritis in this patient.     

对－苯二甲酸衍生物的合成及其诱导分化HL－60细胞的活性

作者合成了１３个对－苯二甲酸衍生物，其中有９个化合物尚未见文献报道。通过对ＨＬ－６０细胞诱导分化活性试验，发现有两个化合物在浓度为５×１０￣（－６）ｍｏｌ／Ｌ时，可使细胞分化率达５５％，低于维Ａ酸的分化率（７９％，１０￣（－７）ｍｏｌ／Ｌ）。     

蘑菇多糖对小鼠腹腔巨噬细胞作用的体外研究

目的 观察蘑菇多糖对小鼠腹腔巨噬细胞免疫调节作用及对体外培养的肿瘤细胞作用的影响。方法 采用比色法测定经蘑菇多糖处理的巨噬细胞内LDH的活性。MTT法观察蘑菇多糖与巨噬细胞的共同培养上清对HL-60细胞及K562细胞的抑制率。结果 （1）蘑菇多糖明显激活小鼠腹腔巨噬细胞的共同培养上清对HL-60细胞及K562细胞的抑制率。结果 （1）蘑菇多糖明显激活小鼠腹腔巨噬细胞，显著提高巨噬细胞的LDH活性；（2）蘑菇多糖作用下的巨噬细胞上清液可显著抑制HL-60细胞及K562细胞的增殖。结论 蘑菇多糖的抗肿瘤作用可能是通过激活小鼠腹腔巨噬细胞的活性实现的。     

Liposomal 1,25 (OH)2 vitamin D3 compounds block proliferation and induce differentiation in myelomonocytic leukaemia cells

The vitamin D₃ derived hormone 1,25 (OH)₂ vitamin D₃ (1,25 D₃) is able to induce growth arrest and differentiation in myelomonocytic leukaemia cells. In order to allow for specific delivery to leukaemic cells the lipophilic compound was incorporated into the lipid membranes of liposomes. Liposomal 1,25 D₃ reduced proliferation as measured by ³H-thymidine incorporation in HL60 leukaemia cells by up to 60%. When liposomes were prepared at different concentrations of 1,25 D₃ 65% inhibition was achieved at 48 n M . The MC 1288 stereoisomer of 1,25 D₃ was more potent and had the same activity at 48 n M .
The effect of the liposomal compounds was specific to myeloid cells as they reduced proliferation in myelomonocytic HL60, monoblastic U937 and monocytic Mono Mac 6 cells but not in the T-cell lines Jurkat and Molt 4.
The antiproliferative effect of liposomal 1,25 D₃ was associated with an induction of differentiation since treated HL60 cells showed a monocytic morphology, increased expression of CD14 and decreased expression of CD33.
When peripheral blood leukaemic cells from M4 and M5 acute myeloid leukaemia (AML) patients were admixed with liposomal compounds an antiproliferative effect was seen in all five cases, including the two cases where free compounds led to enhanced growth. Liposomal delivery of 1,25 (OH)₂ vitamin D₃ may offer a novel approach to treatment of myelomonocytic leukaemia.