There is a higher incidence of hematological clonal stem cell disorders in elderly persons. Age-related alterations of hematopoietic stem and progenitor cells (HSC) may represent one factor ...underlying this observation. However, the molecular changes related to stem cell aging are largely unknown. Therefore, we scrutinized gene expression patterns of HSC from umbilical cord blood (CB) as well as bone marrow from young (BM-Y, mean age 32,8, SD 12,4) and old (BM-O, mean age 88,8, SD 4,4) healthy donors. CD34+ HSC were isolated via immuno-magnetic separation and CD34+ purity was evaluated by FACS analysis. Thereafter we performed cDNA array analyses on a first set of samples (n=18). We found that the BCL2-interacting killer gene (BIK) and the gene encoding KU Antigen 70kD (KU70) show age-related mRNA expression levels. BIK is a proapoptotic gene and its expression was positively correlated with donor's age, i.e. lowest in CB, 1.8-fold higher in BM-Y and 4.2-fold higher in BM-O. KU70 is a DNA repair gene and part of the DNA dependent protein kinase (DNA-PK). Its expression was negatively correlated with donor's age showing highest expression levels in CB, 2.2-fold lower levels in BM-Y and 5.3-fold lower levels in BM-O. These findings were confirmed with a second set of samples (n=16) by means of quantitative RT-PCR. Elucidation of age-dependent molecular alteration in healthy HSC might facilitate a better understanding of hematological malignancies in elderly persons.
Intensive chemotherapy achieves complete remission in about 75% of patients with acute myeloid leukaemia (AML). For patients refractory to intensive chemotherapy, prognosis is very poor and treatment ...options are limited. We report a case of AML which was refractory to induction chemotherapy as well as two salvage regimens. The patient then achieved CR through monotherapy with low-dose azacitidine.
The 57-year-old patient was admitted to our hospital with a diagnosis of AML M1. A bone marrow biopsy revealed a blast count of 88%. The karyotype was 48,XX,+8,+11 4/20. The patient received induction chemotherapy with idarubicin, cytarabine, and etoposide (ICE). Because her disease was refractory to treatment, with a bone marrow blast count of 66%, the patient received a salvage regimen with high-dose cytarabine, mitoxantrone, and all-trans retinoic acid (A-HAM). Still, AML blasts persisted, with a blast count of 52%. The patient then received FLAMSA (fludarabine, amsacrine, and high-dose cytarabine) as a second salvage regimen, but again failed to achieve remission (medullary blast count 50%). Pancytopenia persisted over a period of approximately 3 months (WBC <100/μl, Hb and platelets transfusion-dependent). We then decided to treat her with 5-azacitidine. During the first cycle, she received additional G-CSF because of fungal pneumonia. Azacitidine was given at a dose of 100mg/m2 subcutaneously for 5 days. Treatment was tolerated without side effects. The patient responded swiftly. After the first cycle, peripheral cell counts normalized and the peripheral blast count decreased to 1%. The bone marrow blast count was 3% after 3 cycles, and <1% after 5 cycles. Peripheral blood counts dropped only slightly during treatment cycles, and the patient required no further transfusions. Cytogenetic analysis, including FISH with a centromeric probe for chromosome 8, gave normal results. With the exception of the first cycle, azacitidine was administered in an outpatient setting. After completing the fifth cycle, the patient went on to receive allogeneic stem cell transplantation.
In the nineteen-seventies and -eighties, conventional (cytotoxic) dosages of 5-azacytidine showed some activity against AML, but did not achieve remission rates comparable to high-dose cytarabine. Treatment-related toxicity was considerable. Recently, low-dose azacitidine, supposedly acting as a demethylating agent, was approved for treatment of myelodysplastic syndromes in the U. S.. According to recent studies, methyltransferase inhibitors seem to achieve good response rates in patients with high-risk MDS. Cytogenetic remissions have been achieved in patients with poor risk karyotypes. Our case report confirms that 5-azacitidine can be effective in AML, even in patients who have a poor prognosis with conventional therapeutic approaches.
The NF-kappaB/IkappaB signaling pathway is a critical regulator of cell survival in cancer. Here, we report that combined down-regulation of growth arrest- and DNA-damage-inducible proteins ...(GADD)45alpha and gamma expression by NF-kappaB is an essential step for various cancer types to escape programmed cell death. We demonstrate that inhibition of NF-kappaB in cancer cells results in GADD45alpha- and gamma-dependent induction of apoptosis and inhibition of tumor growth. Inhibition of GADD45alpha and gamma in cancer cells by small interfering RNA abrogates apoptosis induction by the inhibitor of NF-kappaB and blocks c-Jun N-terminal kinase activation, whereas overexpression of GADD45alpha and gamma activates c-Jun N-terminal kinase and induces apoptosis. These results establish an unambiguous role for the GADD45 family as an essential mediator of cell survival in cancer cells with implications for cancer chemotherapy and novel drug discovery.
Surface enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF MS) has facilitated disease-specific serum protein profiles, which may become instrumental for diseases that ...are difficult to diagnose. The diagnosis of MDS can be very difficult since bone marrow dysplasia and peripheral cytopenia, the hallmarks of MDS, can be observed due to many reasons other than MDS. Moreover, cytomorphological evaluation of dysplasia requires extensive experience and is thus dependent on the examiner. Between 2–16% of the patients have a fibrotic bone marrow, which can impede appropriate bone marrow aspiration and smear. Finally, while cytogenetic examination can strongly support the diagnosis of MDS, only 40–50% of the patients have an abnormal karyotype. In the present study, we employed a SELDI-TOF MS-based procedure termed Pattern Track™ in order to analyze a total of 218 serum samples. We generated serum protein profiles from a first sample set comprising 74 patients with MDS, 39 control patients with cytopenia for reasons other than MDS, and 24 healthy persons. We fractionated their serum by means of anion exchange chromatography and applied the resulting serum fractions to weak cationic exchange as well as to reversed phase chromatography ProteinChip™ arrays. We randomly split this dataset into a learning (n=72) and a first independent validation set (n=41). Then, we used a k-nearest-neighbor algorithm to build a class predicting profile that consisted of 81 protein peaks. That profile was tested by leave-one-out cross validation and predicted the diagnosis MDS with an accuracy of 81.9% in the learning set (Fisher's test, P=0.0000003). Then, we tested the profile on our first independent validation set and obtained a similar accuracy of 80.5% (P=0.0002). Its diagnostic performance and long-term reproducibility were confirmed by successfully applying it to a prospectively collected second independent validation set consisting of 81 new samples (P=0.0000006). Eventually, following serial chromatography, 1D gel electrophoresis, and tryptic peptide fingerprinting, we discovered the identity of 2 members of the profile. We conclude that our predicting serum protein profile represents a novel, non-invasive aid in distinguishing patients with MDS from patients with cytopenia for reasons other than MDS.
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