[Trisomy of chromosome 8 in Ph-negative cells of the bone marrow in patients with chronic myeloid leukemia treated with inhibitors of BCR-ABL tyrosine kinases].

AIM: To analyse clinical implications of chromosome 8 trisomy in Ph-negative cells of the bone marrow in patients with chronic myeloid leukemia (CML) treated with inhibitors of tyrosinkinases (ITK). MATERIAL AND METHODS: A total of 386 patients with CML (chronic phase--288, acceleration phase--77) received imatinib (400-800 mg/day). Because of resistance and/or intolerance some patients were switched to ITK II (nilotinib, dasatinib, bozutinib). This study included 8 CML patients (7 in a chronic phase, 1 in acceleration phase) treated with BCR-ABL ITK inhibitors of the first (imatinib) and the second line (ITK-II). The standard cytogenetic examination, on demand--investigation of the interphase nuclei with FISH, in some cases morphological, cytochemical and histological examinations of the bone marrow were made. RESULTS: The existence of a Ph-negative clone with trisomy of chromosome 8 had no negative effect on the course of the disease. The patients showed a stable hematological and cytogenetic response and no need in changing treatment policy. In long-term follow-up Ph-negative clone with trisomy of the chromosome 8 persisted without a clear trend to rise in most patients. CONCLUSION: Detection of a Ph-negative clone with chromosome 8 trisomy at early stages suggests parallel existence of Ph-positive and Ph-negative clones. None of the patients had myelodisplasia.

[Cytogenetic response as a marker of efficacy of chronic myeloid leukemia therapy with a BCR-ABL thyrosine kinase inhibitor glivek].

AIM: Clinical practice with the drug glivek (imatinibe mesilate, ST1571) blocking activity of oncoprotein p210 shows that a cytogenetic response can be reached in 50-60% of patients with chronic myeloid leukemia (CML), in a late chronic phase (CP) in resistance to or intolerance of interferon alpha (IF-alpha) and in 24-43% of patients in the acceleration phase (AP). This study aimed at assessment of the rate and stability of a cytogenetic response (CR) and long-term results of survival in CML patients on glivek. MATERIAL AND METHODS: Glivek was given to 195 CML patients (median of the treatment duration was 42 months, 1-156 months, of the patients' age--46 years). 79 patients were in CP, 116--in AP. The doses were 400 mg/day and 116 mg/day, respectively. Karyotype was studied before the treatment and later after each 6 months. RESULTS: A considerable CR was achieved in 57% patients in CP and 44%--in AP. Of them complete CR was obtained in 48 and 35%, respectively. Marked CR is a favourable prognostic factor. Survival of patients with marked CR in CP (97% 0 and AP (89%) was significantly higher than without CR (58 and 47%, respectively, p < 0.05). Marked CR persisted in 95% cases in both phases of CML. In complete CR, a repeated study of karyotype revealed residual number of Ph+ cells both in CP and AP in 86% patients. This demonstrates necessity to take glivek continuously in achievement of a complete CR by karyotypic test. Glivek inhibits the disease progression, lowers annual lethality. 42-month (median of glivek treatment duration) overall survival reached 91 and 59% in CP and AP, respectively. CONCLUSION: CR is an integral index prognosticating CML course. Survival rose significantly in patients with marked CR both in CP and AP of CML. Marked CR is persistent in continuous glivek therapy. The rate of a CR depends much on the disease stage.

[Is leukemic transformation of donor cells possible?]. / Vozmozhna li leikemicheskaia transformatsiia donorskikh kletok?

AIM: To genotype tumor cells in the recurrence of leukemia after allogenic transplantation of bone marrow (TBM). MATERIAL AND METHODS: Standard cytogenetics and fluorescent hybridization in situ (FISH) with a probe to the centrometic sites of X/Y chromosomes were used in examination of 2 patients with acute promyelocytic and acute non-differentiated leukemia after allogenic TBM from donors of the opposite gender. Bone marrow was studied 1, 2, 3, 6, 9, 12, 15, 17, 18 months after the transplantation. RESULTS: One of the patient in leukemia recurrence there were 72% cells with one X chromosome with unknown origin. 28% donor cells were with genotype XX. The primary archival cytological sample of the recipient's bone marrow 68% cells did not contain Y chromosome. Thus, the clone with Y loss is the recipient's clone and leukemia after transplantation developed from the recipient's cells. The other patient had only 8% dividing cells with her karyotype XX with translocation t(10;11) while 92% metaphases were donor's ones; the interphase cells ratio was 75% of host cells and 25% donor cells. This confirms leukemia origin from the recipient's cells. CONCLUSION: High sensitive quantitative method FISH indicates a true correlation between the host and donor cells and is a method of choice for genotyping leukemic cells in recurrence after transplantation of bone marrow. While standard caryotyping depends on mytotic activity of donor and host cell populations, use of only one cytogenetic test for determination of leukemia origin after TBM may provoke diagnostic errors.

[Molecular-cytogenetic monitoring of different regimens of treatment in patients with chronic myeloid leukemia]. / Molekuliarno-tsitogeneticheskii monitoring razlichnykh rezhimov terapii u bol'nykh khronicheskim mieloleikozom.

AIM: To conduct molecular-cytogenetic monitoring of bone marrow cells in different regimens of chronic myeloid leukemia (CML) treatment. MATERIAL AND METHODS: A total of 651 samples of bone marrow from 319 CML patients were studied. 229 patients received polychemotherapy and 90 patients--interferon-alpha. Primary examination and monitoring of the treatment efficacy were performed using G-differential chromosome staining. Fluorescent in situ hybridization (FISH) was made in 75% cases. RESULTS: Interferon therapy resulted in a significant increase in the number of complete and significant cytogenetic responses. With aggravation of the disease the above responses occurred less frequently while minor and no response are encountered more often. Treatment with interferon-alpha in combination with chemotherapy is much more effective than monotherapy with interferon. CONCLUSION: G-differential chromosome staining karyotypes metaphases and detects clonal chromosome restructuring. Molecular-cytogenetic methods study chromosome restructuring at DNA level. FISH detects chimeric gene bcr/abl in cases when Ph-chromosome is not detectable by standard cytogenetic methods.

[Molecular cytogenetic monitoring of chimerism and minimal residual disease in patient with chronic myeloid leukemia after allogenic and syngenic bone marrow transplantation]. / Molekuliarno-tsitogeneticheskii monitoring khimerizma i minimal'noi ostatochnoi bolezni u bol'nykh khronicheskim mieloleikozom posle allogennoi i singennoi transplantatsii kostnogo mozga.

AIM: To study trends in restoration of normal and tumor hemopoiesis after transplantation of allogenic and syngenic hemopoietic cells. MATERIAL AND METHODS: The examination of bone marrow before transplantation and 1, 2, 3, 6, 9 months, 1, 2 and 3 years after bone marrow transplantation (BMT) was made in 25 patients with chronic myeloid leukemia (CML) after allogenic transplantation of the bone marrow (TBM) and 4 patients after syngenic TBM. The method of G-differential staining of chromosomes and fluorescent hybridization in situ (FISH) with DNA probe to centromeric sites X/Y of chromosomes and genes BCR/ABL was used. RESULTS: 56% of CML patients after allogenic BMT were in cytogenetic and clinicohematological remission, 16% developed early cytogenetic recurrence. Single metaphase with t(9;22) were identified in 28%; 14.3% developed late cytogenetic and hematological recurrence. In patients in posttransplantation remission there were from 0.1 to 5.8% cells of the host. The number of cells of the host and the number of BCR/ABL-positive cells correlated significantly. CONCLUSION: The results of 8-year monitoring of chimerism and minimal residual disease validate application of molecular-cytogenetic methods for assessing transplant condition.

[Study of the time course of mixed chimerism by fluorescent in situ hybridization in patients with chronic myeloid leukemia after allogenic transplantation of bone marrow]. / Izuchenie dinamiki smeshannogo khimerizma metodom fliuorestsentnoi gibridizatsii in situ u bol'nykh khronicheskim mieloleikozom posle allogennoi transplantatsii kostnogo mozga.

AIM: To determine the type of chimerism in patients with chronic myeloid leukemia (CML) in various periods after allogenic transplantation of bone marrow (TBM) and its association with subsequent relapse. MATERIALS AND METHODS: Ten patients were examined after allogenic TBM, which was performed during the chronic phase of CML in 9 patients and during acceleration phase in 1. Two patients received therapy with donor lymphocytes during relapse after transplantation. Time course of chimerism and minimum residual illness was studied by standard cytogenetic methods, fluorescent in situ hybridization (FISH) with DNA probes to centromer sites of X and Y chromosomes and BCR and ABL genes. The studies were carried out 30, 60, 90, 180 days, 9 months, 1 year, and then every 6 months after transplantation. RESULTS: Mixed chimerism was observed in all patients during 9 months after TBM. The count of host cells was 0.1-5.8% in 8 patients; later the count of autologous cells was less than 1% in 5 patients, and in 3 patients complete donor chimerism was observed. Clinical hematological remission was stable in these patients. Relapses of leukemia with 40 and 83.1% host cells occurred in 2 patients 13 and 23 months after transplantation, respectively. Donor lymphocytes were transfused in order to induce the graft versus host effect, and in patient No. 2 restoration of donor hemopoiesis was attained. CONCLUSION: Highly sensitive FISH method with DNA probe to centromer sites of X and Y chromosomes detects early relapse of the disease and demonstrates the time course of donor hemopoiesis recovery after transfusion of donor lymphocytes. The data indicate that 9 months after transplantation molecular cytogenetic studies should be carried out more often (once a month), particularly in patients with poor prognosis, for earlier detection of the relapse and beginning of immunotherapy.

Full-length cDNA cloning and determination of mRNA 5' and 3' ends by amplification of adaptor-ligated cDNA.

An efficient cDNA amplification procedure is described for determining of the 5' and 3' ends of mRNAs and cloning full-length cDNAs. In this approach, a double-stranded (ds) adaptor is ligated to both ends of a library of ds cDNA by T4 DNA ligase. This adaptor-ligated ds cDNA is then used to selectively amplify 5'- or 3'-cDNA fragments by PCR with a combination of gene-specific and adaptor-specific primers. This is a unified method for 5' and 3' rapid amplification of cDNA ends (RACE) from the same adaptor-ligated ds cDNA template. A specially designed adaptor combines features of "vectorette PCR" and "suppression PCR" technologies that significantly reduce background during amplification. The application of "long and accurate PCR" (LA PCR) technology makes possible the amplification of large RACE products and full-length cDNAs with high fidelity to the original mRNA. We investigated efficacy and limitations of this PCR-based approach for cDNA cloning by amplification of 5'- and 3'-RACE fragments and full-length cDNAs of three members of the abundant human actin gene family (1.3-1.9 kb), the medium abundance transferrin receptor mRNA (5.0 kb) and the low-medium abundance insulin-like growth factor II receptor mRNA (9.1 kb).

Combining the technique of RNA fingerprinting and differential display to obtain differentially expressed mRNA.

We have modified recently developed methods of RNA fingerprinting and differential display based on arbitrarily primed PCR which can be used for detection and cloning of differentially expressed mRNAs. Our protocol requires only a single cDNA synthesis for each different RNA sample, in contrast to the multiple cDNA reactions required for differential display method, followed by selective amplification of cDNA sequence fraction by arbitrary and oligo(dT) primers. We have shown that the longer primers (25-29-mers) allow the use of optimal dNTP concentration and higher stringency PCR. Further improvements include using TaqStart antibody for hot start PCR and thermostable enzyme mixes suitable for long-distance PCR. Long-distance PCR enables the method to display bands of up to 2 kb and should result in a higher fidelity of PCR products to the original RNA template. When these improvements are combined the resulting method is highly reproducible, and more than 85% of the differentially expressed bands can be confirmed by Northern blot analysis.

Application of poly(A)+RNA patterns method for searching of differentially expressed genes.

Poly(A)+RNA composition differences for normal, fetal and cirrhotic human liver before and after retinoic acid-induced differentiation of the F9 embryonal carcinoma cell line were analyzed by a novel poly(A)+RNA patterns method. The method is based on the polyacrylamide gel electrophoretic analysis of short cDNA termination products, synthesized by reverse transcriptase using poly(A)+RNA as a template, a set of short 5'-end labeled primers, three natural and one terminator deoxyribonucleotide. A number of known differentially expressed genes and some unknown ones were then identified by direct sequencing of the differentially represented bands excised from a gel and searching a complementary mRNA target sites in Genbank database.

Analysis of poly(A)+RNA patterns in human tissues.

A novel method for analysing and comparing the relative amounts of the most abundant (higher than 0.1% abundance) individual mRNAs present in different poly(A)+RNA preparations has been developed. This method is based on the synthesis of short (10-30 nucleotide) cDNA termination products, by reverse transcription of poly(A)+RNA primed with a 5'-labeled oligonucleotide. A set of 30 different oligonucleotides are used as primers in separate reactions, their length and sequences having been chosen to provide more than a 90% probability of initiating synthesis from any individual RNA present in the poly(A)+RNA. Each primer produces about 10-60 bands per track, following polyacrylamide gel electrophoresis under denaturing conditions. Data presented reveals poly(A)+RNA pattern differences for a number of human tissues and identifies changes in RNA patterns between normal tissues and neoplastic human tumors (myoma of the uterus) from several individuals.

[Analogs of nucleotides, modified by a sugar residue and pyrimidine base, in a DNA synthesis reaction, catalyzed by Thermus aquaticus DNA polymerase]. / Analogi nukleotidov, modifitsirovannye po sakharnomu ostatku i pyrimidinovomu osnovaniiu, v reaktsii sinteza DNK, kataliziruemogo DNK-polimerazoi Thermus aquaticus.

Substrate properties of dNTP analogues in the DNA synthesis reaction catalyzed by Thermus aquaticus DNA polymerase were studied. It was shown that most of dNTP analogues which were known as terminators of DNA synthesis of E. coli DNA polymerase I were able to terminate DNA synthesis catalyzed by Thermus aquaticus DNA polymerase. An interesting feature of Thermus aquaticus DNA polymerase was the ability to utilize 3'-azido-2',3'-dideoxythymidine triphosphate as terminating substrate. Relative efficiency of tested dNTP analogues incorporation into the DNA growing chain was estimated.

[Study of the DNA structure of peripheral blood leukocytes, proliferating lymphoid and tumor cells according to the rate of alkaline denaturation of DNA lysates]. / Izuchenie struktury DNK leikotsitov perifericheskoi krovi, proliferiruiushchikh limfoidnykh i opukholevykh kletok po skorosti shchelochnoi denaturatsii DNK lizatov.

Direct fluorometry was used to identify quantitative differences in the DNA structure of human peripheral blood leukocytes and proliferating lymphoid cells. The differences should be taken into account in the study of varied damaging actions.