Three patients with structurally abnormal X chromosomes, each with Xq13 breakpoints and a history of idiopathic acquired sideroblastic anemia

Structural abnormalities of the X chromosome are rarely found in neoplastic disorders. We describe three patients with a history of idiopathic acquired sideroblastic anemia (IASA); each one had an abnormal clone of cells in the bone marrow, characterized by a structurally abnormal X chromosome. In two of these patients, the predominant karyotype was 47,X,2idic(X)(q13); in the other patient, it was 46,X,t(X;11)(q13;p15). Inasmuch as all three of these cases involved chromosome band Xq13, as did two previously published cases, we suggest that band Xq13 may be more prone to structural rearrangement than other X chromosome bands in hematologic disorders. The common Xq13 chromosome breakpoint and clinical presentation (IASA) among these three patients and the occurrence of an X-linked type of sideroblastic anemia may suggest that an association exists between X chromosome abnormalities and IASA. Perhaps alteration of a gene or chromosome structure in or near band Xq13 predisposes to development of IASA. The fact that two of these patients had preleukemia and the third had overt acute leukemia may imply that patients with IASA and X chromosome abnormalities have a poor prognosis. Cases of IASA without associated X chromosome abnormalities are known; thus, if an association between IASA and an abnormal X chromosome does exist, most likely it involves only some patients with IASA.     

Activation of the CPP32 protease in apoptosis induced by 1-beta-D- arabinofuranosylcytosine and other DNA-damaging agents

The response of human myeloid leukemia cells to treatment with 1-beta- arabinofuranosylcytosine (ara-C) includes the induction of apoptosis. Ara-C induced apoptosis is associated with proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) and protein kinase C (PKC) delta. However, the signals involved in this response are unknown. The present studies show that ara-C treatment of U-937 cells is associated with induction of a protease activity that cleaves the tetrapeptides Ac-DEVD- pNA and Ac-DMOD-pNA found at the cleavage sites of PARP and PKC delta, respectively. The ara-C-induced protease activity was sensitive to overexpression of the anti-apoptotic protein Bcl-xL and the baculovirus protein p35. By contrast, overexpression of the cowpox virus protein CrmA blocked apoptosis induced by engagement of the Fas receptor but not that induced by ara-C. CrmA overexpression also had no detectable effect on ara-C-induced cleavage of PKC delta. The results further show that ara-C induces activation of the CPP32 protease by a CrmA- insensitive and p35-sensitive mechanism. Similar results were obtained with cisplatinum, etoposide, and camptothecin. These findings indicate that ara-C and other DNA-damaging agents activate a CrmA-insensitive apoptotic pathway involving CPP32 and that these signals differ from those associated with apoptosis induced by the Fas receptor.     

DNA aneuploidy and cell proliferation in breast tumors

The cellular DNA content of 30 benign and 180 malignant breast tumors was analyzed by means of flow cytometry (FCM). All benign tumors exhibited a normal DNA content (diploid), whereas 65% of the malignant tumors showed an abnormal DNA content (aneuploid). The ploidy distribution of malignant tumors was bimodal with an increasing frequency near diploid DNA index (DI), and a second group had a DI ranging from triploid to tetraploid. In estimating the degree of malignancy eight independent histomorphologic and cytologic criteria were introduced. A good correlation was observed between DNA content abnormalities and the grade of differentiation of breast carcinomas. The percentage of S-phase cells of DNA aneuploid cell lines was significantly higher than in the diploid ones. The highly differentiated breast carcinomas (Grade 1) indicated lower S-phase values as compared to the undifferentiated (Grade 3) ones. S-phase values estimated by FCM were about two times higher than the 3H-thymidine labeling index (LI) obtained by an in vitro procedure. The data estimated in this study showed that DNA determinations as an adjunct to conventional histopathologic assessment may provide objective clinically relevant information with respect to the degree of malignancy and prognosis of patients with breast carcinoma.     

Photodynamic therapy of experimental tumours with Zn(II)-phthalocyanine and pulsed laser irradiation

The effectiveness of a pulsed dye laser (673 nm) for photodynamic therapy (PDT) of tumours in the presence of Zn(II)-phthalocyanine (ZnPc) was evaluated using Lewis lung carcinoma-bearing mice. The tumours were irradiated with different pulse energies (from 0.4 to 10 mJ) at a constant fluence of 0.6 J cm^–2 at 24 h after administration of 0.25 mg kg^–1 body weight liposome-incorporated ZnPc. Maximal PDT effect, as evaluated by changes in mean tumour diameter, animal survival time and histological evaluation of tumour necrosis, was observed after 3.0 mJ pulse energy irradiation which appears to yield a deeper light penetration and a more efficient sensitizer excitation when compared with lower or higher pulse energies. Electron microscopic analysis of photo-treated tumour indicates preferential damage to malignant tissue as compared to endothelial cells.     

人ERRα基因小分子干扰RNA慢病毒载体构建及鉴定

目的构建并鉴定靶向人ERRα基因的小分子干扰RNA的慢病毒载体。方法针对ERRαmRNA设计了4条si RNA,并构建pGCSIL-GFP-siERRα慢病毒质粒,PCR扩增阳性克隆并测序鉴定。用pGCSIL-GFP-siERRα、pHelp-er1.0和pHelper2.0质粒共转染293T细胞包装产生慢病毒,测定病毒滴度。将慢病毒干扰RNA及含有ERRα过表达载体共转染293T细胞,Western-blot检测ERRα表达,观察蛋白表达抑制效果。结果 PCR和测序结果与设计的干扰序列一致,病毒滴度达2×109TU/ml。转染细胞中ERRα蛋白表达显著降低。结论成功构建高表达、高效率的人ERRα基因小分子干扰RNA慢病毒载体,为进一步研究ERRα在细胞核内转导中的作用机制和靶向ERRα治疗奠定基础。     

Association of CyclinD1 copy number changes with histological type in ovarian tumors

Literature data on the occurrence of CCND1 alterations in ovarian tumors are insufficient. The objective of this study was to assess the incidence of CCND1 copy number changes in a large number of ovarian tumors and its relation to the tumor phenotype: degree of malignancy, histological type, tumor stage, and grade. Fluorescence in situ hybridization (FISH) for analysis of CCND1 copy number changes was applied on a collection of 1 006 ovarian tumors--468 malignant, 48 with low malignant potency, and 490 benign tumors--arranged in tissue microarray. CCND1 amplification was found in 8.46% of the malignant cases and in 8.11% of those with low malignant potency. It was not found in benign ovarian tumors. CCND1 amplification was associated with the mucinous type of ovarian cancer (p<0.0001). CCND1 genetic gain was revealed in 9.06% of the malignant tumors, in 2.70% of the tumors with low malignant potency, and in 4.87% of the benign ovarian tumors. CCND1 gains and amplifications were not associated with the tumor grade and stage. Our results suggest that CCND1 gains are early events in ovarian tumorogenesis.     

The immunocompromised district: a unifying concept for lymphoedematous, herpes-infected and otherwise damaged sites

Systemic immunodeficiency is known to facilitate the onset of opportunistic infections, tumours and immune disorders in any district of the body. There are clinical events, such as chronic lymphoedema, herpetic infections, vaccinations and heterogeneous physical injuries which can selectively damage and immunologically mark the cutaneous district they act upon. After the causing event has disappeared, the affected district may appear clinically normal, but its immune behaviour is often compromised forever. An immunocompromised district becomes a site which is particularly susceptible to subsequent outbreaks of opportunistic infections, tumours and immune disorders confined to the district itself.
In this review, there is an ample case-report collection of opportunistic disorders (infectious, neoplastic, immune) which appeared in immunocompromised districts. The cases have been grouped according to the clinical settings responsible for the local immune imbalance: regional chronic lymphoedema; herpes-infected sites, which feature the well-known Wolf's isotopic response; and otherwise damaged areas, comprising sites of vaccination, ionizing or UV radiation, thermal burns and traumas.
Whatever the immunocompromising factor, a common denominator which facilitates the occurrence of tumours, infections and dysimmune reactions in an immunocompromised district may reside in locally hampered lymph drainage and/or locally altered neuromediator signalling. In fact, any obstacle to the normal trafficking of immunocompetent cells through lymphatic channels or any interference with the signals that the neuropeptides and neurotransmitters released by peripheral nerves send to cell membrane receptors of immunocompetent cells, can significantly alter the local immune response, thus paving the way for heterogeneous opportunistic disorders in the immunocompromised district.