Excess of miRNA-378a-5p perturbs mitotic fidelity and correlates with breast cancer tumourigenesis in vivo.

BACKGROUND: Optimal expression and proper function of key mitotic proteins facilitate control and repair processes that aim to prevent loss or gain of chromosomes, a hallmark of cancer. Altered expression of small regulatory microRNAs is associated with tumourigenesis and metastasis but the impact on mitotic signalling has remained unclear. METHODS: Cell-based high-throughput screen identified miR-378a-5p as a mitosis perturbing microRNA. Transient transfections, immunofluorescence, western blotting, time-lapse microscopy, FISH and reporter assays were used to characterise the mitotic anomalies by excess miR-378a-5p. Analysis of microRNA profiles in breast tumours was performed. RESULTS: Overexpression of miR-378a-5p induced numerical chromosome changes in cells and abrogated taxol-induced mitotic block via premature inactivation of the spindle assembly checkpoint. Moreover, excess miR-378a-5p triggered receptor tyrosine kinase-MAP kinase pathway signalling, and was associated with suppression of Aurora B kinase. In breast cancer in vivo, we found that high miR-378a-5p levels correlate with the most aggressive, poorly differentiated forms of cancer. INTERPRETATION: Downregulation of Aurora B by excess miR-378a-5p can explain the observed microtubule drug resistance and increased chromosomal imbalance in the microRNA-overexpressing cells. The results suggest that breast tumours may deploy high miR-378a-5p levels to gain growth advantage and antagonise taxane therapy.

Variant Bernard-Soulier syndrome due to homozygous Asn45Ser mutation in the platelet glycoprotein (GP) IX in seven patients of five unrelated Finnish families.

Bernard-Soulier syndrome (BSS), a rare bleeding disorder with macrothrombocytopenia, is caused by a defect of the platelet glycoprotein (GP) Ib/IX/V complex. Here we report a variant form of BSS in eleven patients of five unrelated families who originate from a particular area of Finland. The differential diagnosis from idiopathic thrombocytopenic purpura was difficult. Bleeding symptoms were epistaxis and haematomas debuting in childhood, but no spontaneous, severe bleeding episodes were reported. The platelet count varied from 43 to 81x10(9)/l. Screening the entire GP Ibalpha, GP Ibbeta, GP IX and GP V genes revealed a recurrent homozygous Asn45Ser mutation in GP IX in all probands. Flow cytometry showed markedly reduced expression of GP Ib (<10%), and only moderately reduced expression of GP IX (24-36%) and GP V (38-49%). The expression of subunits seemed to vary independently from the normal polymorphisms. Heterozygotes did not differ significantly from controls by their GP Ib/IX/V expression. Since the Asn45Ser mutation has also been reported in three other kindreds of northern and central European origin, this study reveals that instead of being a mutation hot spot, it may be ancient and scattered in Europe. Moderate, chronic thrombocytopenia should be carefully studied to diagnose variant BSS correctly from treatment resistant idiopathic thrombocytopenia.

Corticosteroid is not beneficial in multiple-drug combination chemotherapy for multiple myeloma. Finnish Leukaemia Group.

In a randomised multicentre trial a combination of methylprednisolone, vincristine, lomustine, cyclophosphamide and melphalan (MOCCA) was compared with the same regimen omitting methylprednisolone after the first course (COLA) in previously untreated patients with multiple myeloma. The MOCCA arm showed a response rate of 72% among 79 patients and the COLA arm a response rate of 60% among 59 patients. This difference was not statistically significant. The median survival time was 56 months in the MOCCA arm and 61 months in the COLA arm. There was a slight increase of early deaths (within the first 6 months) in the MOCCA arm as compared with the COLA arm. We conclude that, in multidrug therapies, the continuation of corticosteroid at conventional dosage beyond the first course does not improve response rate or survival time in multiple myeloma.

Value of maintenance therapy with chemotherapy or interferon during remission of acute myeloid leukaemia.

108 consecutive patients with de novo acute myeloid leukaemia at ages 15 to 59 years were treated in a prospective controlled multicentre trial. Induction with combination TAD resulted in a complete remission in 85 cases (79%). After a cyclic consolidation programme for 6 months, 73% of the remissions continued. The maintenance therapy was at random either nothing, or alpha interferon, or monthly 5 day courses with thioguanine and cytarabine. The median duration of all remissions was 13 months; that of those in the control and interferon arms 15 months each, and in the chemotherapy arm 18 months. The median survival of all the 108 patients was 16 months; that of those in the control arm 20 months, in the interferon arm 33 months and in the chemotherapy arm 26 months. At 5 yr, 31%, 22% and 31%, respectively, were alive. The survival curves did not differ from each other significantly. Maintenance treatment after an intensive induction and a moderately intensive consolidation was of no benefit in this study. Interferon did not improve the prognosis.

Intensive chemotherapy with combinations containing anthracyclines for refractory and relapsing multiple myeloma. Finnish Leukaemia Group.

94 patients with refractory multiple myeloma were treated in a multicentre trial with combinations of cytotoxic drugs including anthracyclines. All were refractory to a 5-drug combination containing 3 alkylating agents, vincristine and methylprednisolone (MOCCA). With a combination of epirubicin and iphosphamide a 50% response was achieved in 9% of 22 patients. The response rate after schedule VAP (vincristine, doxorubicin and prednisolone) was 8% of 13 patients and that after schedule VAD (vincristine, doxorubicin and dexamethasone) 20% of 59 patients. The previous chemotherapy had lasted for less than 12 months in 13 cases from among all these patients, and 5 of these (38%) responded. In contrast, there were only 10 responders (12%) among the 81 patients with longer previous chemotherapy.

Effect of the Choice of Primary Chemotherapy on the Cumulative Length of Stay in Hospital for Multiple Myeloma.

The actual use of hospital beds for patients with multiple myeloma was calculated from a randomised trial of primary treatment with either melphalan and prednisone (MP, 66 patients) or intensive combination chemotherapy with vincristine, cyclophosphamide, lomustine, melphalan and methylprednisolone (MOCCA, 64 patients). The survival of the patients was similar in both arms, and the samples, 20 and 32 patients, respectively, were well representative for the whole arms. The average numbers of hospital days were similar fur both arms. For the first year MP 33.2 (SD 27.6) vs. MOCCA 32.1 (SD 19.0), and during the first to 4th years 78.5 (SD 45.9) vs. 67.8 (SD 34.1). For the year of death it was 50.4 (SD 33.1) vii. 36.3 (SD 27.0), respectivelly. Thus the choice of primary chemotherapy whether conventional or more aggressive had no influence on the actual number of in-patient hospital days concerned. When the combination chemotherapy schedule is well tolerated it can be administered just as well on an ambulatory basis or by using it with very short admissions. It seems that the need for inpatient care for patients with multiple myeloma is mostly related to the complications of the disease itself and to intercurrent disorders including infections.

Treatment of multiple myeloma in old patients. Finnish Leukaemia Group.

Patients aged 70 yr or older with multiple myeloma were treated, when suitable, according to concurrent trial protocols for younger patients, with the exception that the cytostatic regimen was not allocated at random. Intermittent melphalan and prednisone (MP) was given as the primary treatment to 42 patients and 5-drug combination MOCCA to 68 patients. The groups were comparable with each other, and the distribution of the clinical stages of the patients was similar to the younger patients in concurrent trials. An at least 50% response was achieved in 33% (SE 7.3) with MP and in 75% (SE 5.3) with MOCCA. The median survival times were 39 and 32 months, the relative age-adjusted survival times 45 and 41 months, respectively. Advanced age as such is thus no contraindication for active treatment of myeloma, and in suitable patients the results compare well with those achieved in younger patients.

Bronchiolo-alveolitis with pulmonary basal lamina injury in a rheumatoid patient during gold treatment.

A 47-year-old housewife presented with nonproductive cough, progressive breathlessness and intermittent fever during gold treatment, originally prescribed for seropositive polyarthritis, which later fulfilled the criteria for systemic lupus erythematosus (SLE). An open lung biopsy showed abundant interstitial edema with mononuclear inflammatory cells and some eosinophils, and slight bronchiolitis. The picture was nonspecific but suggestive of hypersensitivity pneumonitis. Electron microscopy revealed splitting and local disappearance of the basal laminae of the alveolar capillaries, venules and alveolar epithelium. This injury was confirmed by immunohistochemical staining for type IV collagen and laminin, the major components of basal laminae. In most macrophages there was lysosomal electron dense granular material, i.e. aurosomes, which gave the spectrum of gold in electron microprobe analysis. After the gold treatment was stopped the pulmonary symptoms gradually decreased during several months and no permanent lung disease remained. Whereas the pulmonary manifestation could have been due to her underlying disease we discuss in this study the possibility of its being gold induced.