Aging of mesenchymal stem cell in vitro

BACKGROUND: A hot new topic in medical treatment is the use of mesenchymal stem cells (MSC) in therapy. The low frequency of this subpopulation of stem cells in bone marrow (BM) necessitates their in vitro expansion prior to clinical use. We evaluated the effect of long term culture on the senescence of these cells. RESULTS: The mean long term culture was 118 days and the mean passage number was 9. The average number of PD decreased from 7.7 to 1.2 in the 10th passage. The mean telomere length decreased from 9.19 Kbp to 8.7 kbp in the 9th passage. Differentiation potential dropped from the 6th passage on. The culture's morphological abnormalities were typical of the Hayflick model of cellular aging. CONCLUSION: We believe that MSC enter senescence almost undetectably from the moment of in vitro culturing. Simultaneously these cells are losing their stem cell characteristics. Therefore, it is much better to consider them for cell and gene therapy early on

Prognostic factors of survival time after hematopoietic stem cell transplant in acute lymphoblastic leukemia patients: Cox proportional hazard versus accelerated failure time models

<p>Abstract</p> <p>Background</p> <p>The aim of this study is to evaluate the prognostic factors of overall survival (OS) after haematopoietic stem cell transplant (HSCT) in acute lymphoblastic leukaemia (ALL) patients using accelerated failure time (AFT), Cox proportional hazard (PH), and Cox time-varying coefficient models.</p> <p>Methods</p> <p>206 patients were enrolled after HSCH in Shariati Hospital between 1993 and 2007. There was evidence of marked departures from the proportional hazards assumption with two prognostic factors, relapse and chronic graft-versus-host disease (cGVHD) (P < .001). Performance among AFT and Cox's models was assessed using explained variation and goodness of fit methods. Discrimination among the exponential, Weibull, generalized gamma (GG), log-logistic, and lognormal distributions was done using maximum likelihood and Akaike information criteria.</p> <p>Results</p> <p>The 5-year OS was 52% (95%CI: 47.3–56.7). Peak mortality hazard occurred at months 6–7 after HSCT followed by a decreasing trend. In univariate analysis, the data was better fitted by GG distribution than by other distributions. Univariate analysis using GG distribution showed a positive association between OS with acute graft-versus-host disease (aGVHD) (P = .021), no relapse (P < .001), cGVHD (P < .001), neutrophil recovery (P < .001) and platelet recovery (P < .001). Based on Cox PH models; however cGVHD and relapse were the predictive factors of OS (P < .001). Multivariate analysis indicated that, OS is related to relapse (P < .001) and platelet recovery (P = .037), where predictive power of Weibull AFT models was superior to Cox PH model and Cox with time-varying coefficient (R²= 0.46 for AFT, R²= .21 for Cox PH and R²= .34 for Cox time-varying coefficient). Cox-Snell residual shows Weibull AFT fitted to data better than other distributions in multivariate analysis.</p> <p>Conclusion</p> <p>We concluded that AFT distributions can be a useful tool for recognizing prognostic factors of OS in acute lymphoblastic leukemia patients.</p

Efficacy and Safety of the Irinotecan, Capecitabine, and Oxaliplatin (IOX) Regimen in Metastatic Gastric Cancer: A Single Arm Phase II Trial

Background: Gastric cancer is one of the most common malignancies worldwide with a high case mortality rate. In metastatic gastric cancer, a proper combination of chemotherapy could increase the survival rate. The goal of this study is to evaluate the efficacy and safety of the combination regimen of irinotecan, oxaliplatin, and Xeloda in metastatic gastric cancer. Methods: A total of 45 patients with metastatic gastric cancer and good performance status according to the Eastern Cooperative Oncology Group (score: 0-1) received the irinotecan, oxaliplatin, and Xeloda chemotherapy regimen. Demographic data, responses to treatment, and adverse effects were gathered for all cases. Overall survival and progression-free survival rates for patients were calculated using the Kaplan-Meier estimate. Results: Patients’ mean age was 58.3 ± 11.3 years (range: 24-81). There were 73.4% male patients and 26.6% female patients. Anorexia and weight loss were the most common symptoms. Overall response rate was 50%. The majority of toxicities were anemia, nausea and vomiting (grades 1 and 2), diarrhea (grades 1 and 2), neutropenia, alopecia, and hand and foot syndrome. The one-year progression-free survival rate was 31.5 ± 7.5%, whereas the twoyear progression-free survival rate was zero. The one-year overall survival rate was 34.91 ± 8.5%. Patients had a two-year overall survival rate of 7.7 ± 6.6%. Diffuse type cancer was linked to an inferior outcome. Conclusion: Regardless of our limited number of patients, this combination could be a suitable regimen for metastatic gastric cancer in terms of low toxicity, acceptable response rate, and survival results

Comparison of Prognostic Factors and Death Hazard Function of Acute Myeloid Leukemia (AML) and Acute Lymphoblastic Leukemia (ALL) Patients after Bone Marrow Transplantation

&quot;nIntroduction: The majority of leukemia patients are acute leukemia patients, so that about 70.8% lymphoblastic leukemia were acute lymphoblastic leukemia (ALL) patients and 66.4 % of myeloid leukemia patients were acute myeloid leukemia (AML) in Tehran metropolitan. During the last two decades, intensification of therapy by the use of high-dose Cytarabine allogeneic stem cell transplantation in selected cases, paralleled by improvement in supportive care may have contributed to the impotent. In this article we use parametric survival models for recognizing prognostic factors in acute leukemia patients. &quot;nPatients and methods: Data on patients who underwent bone marrow or peripheral blood transplantation were obtained from the Hematology- Oncology and bone marrow transplantation research center at Shariati hospital, Tehran, Iran. Transplantations were performed between Oct. 17, 1993 to Jan. 31, 2007. Written informed consents for hematopoietic cell collection and transplantation were obtained from patients and donors. The study included patients 2 to 56 years of age who had received either an HLA-matched marrow transplant or a marrow transplant with a single HLA mismatch from an unrelated donor. The mean follow- up period was about 2 years after transplantation. &quot;nResults: Five hundred and seven patients were included in the study. There were 301 with acute myeloid leukemia (AML) and 206 with acute lymphoblastic leukemia (ALL). The median ages of the AML and ALL patients were 27 (2-55) and 20 years (2-52), respectively. In ALL patients, Prior viral exposure- cytomegalovirus antibody was positive in 143 patients and negative in 30 patients. In AML patients&amp;rsquo; Prior viral exposure- cytomegalovirus antibody was positive in 220 patients and negative in 41patients. Table- 1 shows the characteristics of 507 patients who included in the study. &quot;nConclusion: In spite of no significant difference in follow-up time, serological status (CMV), donor-recipients sex match, bone marrow cell dose(WBC, CD34, MNC), donor type, source of stem cell, graft type, and conditioning regimen, (Busulfan- Oral, Cyclophosphamide, ALG/AIS/ATG, Stoposide)(Table- 1) in both AML and ALL patients, generalized gamma distribution shows that the mean of SBMT in AML patients is 2.52 times of ALL patients

The role of KIR-HLA combination in hematopoietic stem cells transplantation

Background : Allogeneic hematopoietic stem cells transplantation (HSCT) is a valuable therapy for refractory acute leukemias, leukemias with a high risk for relapse, myelodysplastic syndromes, and chronic myeloid leukemia. HSCT outcome is dependent on several factors, including the stage of disease, degree of human leukocyte antigen (HLA) identity between donor and recipient, conditioning regimen, and development of graft-versus-host disease (GVHD). Recent studies have indicated that another potential factor influencing transplantation outcome is the presence of donor-derived alloreactive natural killer (NK) cells. NK cell alloreactivity has been defined as a mismatch between the donor and recipient killer immunoglobulin-like receptor (KIR) ligands (ligand-ligand model), or as recipient lacking KIR ligands for donor inhibitory KIR (receptor-ligand model), or as a mismatch between the donor and recipient KIR genes (gene-gene model). The anti-leukemic effects of NK cell alloreactivity include lower rates of relapse, graft failure, and GVHD, ultimately translating into higher overall survival (OS). However, the effects of NK cell alloreactivity on the outcome of HSCT in malignant hematopoietic diseases is a topic of debatable

Detection of nucleophosmin and FMS-like tyrosine kinase-3 gene mutations in acute myeloid leukemia

Background and Objectives : Nucleophosmin gene mutations are frequently reported in acute myeloid leukemia (AML) patients with normal karyotype, which is also frequently associated with internal tandem duplication mutations in the FMS-like tyrosine kinase-3 gene. We sought to detect the nucleophosmin and FMS-like tyrosine kinase-3 (FLT3) internal tandem duplication (ITD) mutations among Iranian patients with AML and to assess the relationship between these mutations and the subtypes of the disease. Design and Setting : Cross-sectional study of patients referred during 2007 through 2009. Patients and Methods : Bone marrow and peripheral blood samples of 131 AML patients were randomly collected at the time of diagnosis and prior to treatment and the DNA extracted. After amplifying the nucleophosmin and FLT3 gene regions, positive cases were screened by conformation-sensitive gel electrophoresis and agarose gel electrophoresis techniques. Results : Of 131 patients, 23 (17.5&#x0025;) (0.95&#x0025; CI=0.107-0.244) had nucleophosmin gene mutations. The highest frequency of such mutations was found among the subtypes of M4 (30.4&#x0025;), M3 (21.7&#x0025;) and M5 (17.4&#x0025;). There was a high frequency of these mutations in the M3 subtype as well as a high frequency of allele D in all subtypes. Also, 21 (16.0&#x0025;) samples (0.95&#x0025; CI=0.092-0.229) had FLT3/ITD mutation, of which 8 samples had mutant nucleophosmin (8 of 23, 35&#x0025;), and another 13 samples had wild-type nucleophosmin gene (13 of 108, 12&#x0025;). There was a high degree of association between the occurrence of nucleophosmin and FLT3/ITD mutations (P=.012). Conclusion : Our data showed a high frequency of NPM1 mutations in the monocytic subtypes of AML, as well as a high degree of association between the occurrence of NPM1 and FLT3/ITD mutations

Expression of MRP1 gene in acute leukemia

CONTEXT AND OBJECTIVE: Overexpression of the multidrug resistance-associated protein 1 (MRP1) gene has been linked with resistance to chemotherapy in vitro, but little is known about its clinical impact on acute leukemia patients. Our aim was to investigate the possible association between MRP1 gene expression level and clinical outcomes among Iranian leukemia patients. DESIGN AND SETTING: This was an analytical cross-sectional study on patients referred to the Hematology, Oncology and Stem Cell Research Center, Sharyatee Public Hospital, whose diagnosis was acute myelogenous leukemia (AML) or acute lymphoblastic leukemia (ALL). All molecular work was performed at NIGEB (public institution). METHODS: To correlate with prognostic markers and the clinical outcome of acute leukemia, MRP1 gene expression was assessed in 35 AML cases and 17 ALL cases, using the quantitative real-time polymerase chain reaction and comparing this to the chemotherapy response type. RESULTS: Mean expression in AML patients in complete remission (0.032 ± 0.031) was significantly lower than in relapsed cases (0.422 ± 0.297). In contrast, no significant difference in MRP1 mRNA level was observed between complete remission and relapsed ALL patients. There was a difference in MRP1 expression between patients with unfavorable and favorable cytogenetic prognosis (0.670 ± 0.074 and 0.028 ± 0.013, respectively). MRP1 expression in M5 was significantly higher (p-value = 0.001) than in other subtypes. CONCLUSIONS: The findings suggest that high MRP1 expression was associated with poor clinical outcome and was correlated with the M5 subtype and poor cytogenetic subgroups among AML patients but not among ALL patients