Jan S. Moreb

Lenalidomide after stem-cell transplantation for multiple myeloma

BACKGROUND Data are lacking on whether lenalidomide maintenance therapy prolongs the time to disease progression after autologous hematopoietic stem-cell transplantation in patients with multiple myeloma. METHODS Between April 2005 and July 2009, we randomly assigned 460 patients who were younger than 71 years of age and had stable disease or a marginal, partial, or complete response 100 days after undergoing stem-cell transplantation to lenalidomide or placebo, which was administered until disease progression. The starting dose of lenalidomide was 10 mg per day (range, 5 to 15). RESULTS The study-drug assignments were unblinded in 2009, when a planned interim analysis showed a significantly longer time to disease progression in the lenalidomide group. At unblinding, 20% of patients who received lenalidomide and 44% of patients who received placebo had progressive disease or had died (P<0.001); of the remaining 128 patients who received placebo and who did not have progressive disease, 86 crossed over to lenalidomide. At a median follow-up of 34 months, 86 of 231 patients who received lenalidomide (37%) and 132 of 229 patients who received placebo (58%) had disease progression or had died. The median time to progression was 46 months in the lenalidomide group and 27 months in the placebo group (P<0.001). A total of 35 patients who received lenalidomide (15%) and 53 patients who received placebo (23%) died (P=0.03). More grade 3 or 4 hematologic adverse events and grade 3 nonhematologic adverse events occurred in patients who received lenalidomide (P<0.001 for both comparisons). Second primary cancers occurred in 18 patients who received lenalidomide (8%) and 6 patients who received placebo (3%). CONCLUSIONS Lenalidomide maintenance therapy, initiated at day 100 after hematopoietic stem-cell transplantation, was associated with more toxicity and second cancers but a significantly longer time to disease progression and significantly improved overall survival among patients with myeloma. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00114101.).

Late onset of invasive aspergillus infection in bone marrow transplant patients at a university hospital

Despite new antifungal treatment strategies, invasive aspergillosis (IA) remains a principal cause of infectious mortality after bone marrow transplantation (BMT). We reviewed the medical records of 93 allogeneic and 149 autologous transplant recipients during a 20 month period, with attention to cases of proven or probable IA. No autologous transplant recipient developed IA, whereas IA was seen in 15.1% of allogeneic recipients (including two of five patients with a prior history of IA despite prophylaxis), for an overall incidence of 5.8%. The median time to occurrence was 92 days post transplant, with no de novo cases developing prior to engraftment. Survival 100 days from diagnosis was 29%. Risk factors for the development of IA included ⩾21 days of corticosteroid therapy of ⩾1 mg/kg/day and post-transplant cytomegalovirus (CMV) infection. These two risk factors were statistically linked. Our data illustrate a shift toward a later occurrence of post-transplant IA, suggesting a need for close, prolonged surveillance in the outpatient environment. The contributory role of protracted corticosteroid use is also highlighted. These data have important implications in an era of alternate donor transplants and more intense immunosuppression. Established strategies implementing newer, less toxic antifungal agents as prophylaxis in high-risk patients are needed.Bone Marrow Transplantation (2002) 29, 15–19. doi:10.1038/sj.bmt.1703332

Aldehyde dehydrogenase as a marker for stem cells.

Multiple aldehyde dehydrogenase genes have been identified in many tissues. Aldehyde dehydrogenase class 1A1 (ALDH1A1) has been identified as highly expressed in embryonal tissue as well as in adult stem cells isolated from bone marrow, brain, breast and possibly other tissues. The recent interest in the idea of cancer stem cells (CSC) has resulted in renewed and vigorous interest in aldehyde dehydrogenase activity as a marker for those stem cells as well. It has been known that ALDH activity, which may reflect other ALDH isozymes in addition to ALDH1A1, is important for multiple biological activities including drug resistance, cell differentiation, and oxidative stress response. Purification of viable cells with high ALDH activity has become relatively easy with the availability of flow cytometry based assay. In this review, we examine the data available in regarding the importance of ALDH activity in normal and malignant stem cell functions, and the potential diagnostic and therapeutic implications. We review the available tools that can impact ALDH activity and may have the potential to be used therapeutically, specifically targeting the CSC. We raise questions that need to be investigated before a reasonable therapeutic strategy can be devised that will effectively inhibit ALDH activity.

Aldehyde dehydrogenase activity as a functional marker for lung cancer

Aldehyde dehydrogenase (ALDH) activity has been implicated in multiple biological and biochemical pathways and has been used to identify potential cancer stem cells. Our main hypothesis is that ALDH activity may be a lung cancer stem cell marker. Using flow cytometry, we sorted cells with bright (ALDH(br)) and dim (ALDH(lo)) ALDH activity found in H522 lung cancer cell line. We used in vitro proliferation and colony assays as well as a xenograft animal model to test our hypothesis. Cytogenetic analysis demonstrated that the ALDH(br) cells are indeed a different clone, but when left in normal culture conditions will give rise to ALDH(lo) cells. Furthermore, the ALDH(br) cells grow slower, have low clonal efficiency, and give rise to morphologically distinct colonies. The ability to form primary xenografts in NOD/SCID mice by ALDH(br) and ALDH(lo) cells was tested by injecting single cell suspension under the skin in each flank of same animal. Tumor size was calculated weekly. ALDH1A1 and ALDH3A1 immunohistochemistry (IHC) was performed on excised tumors. These tumors were also used to re-establish cell suspension, measure ALDH activity, and re-injection for secondary and tertiary transplants. The results indicate that both cell types can form tumors but the ones from ALDH(br) cells grew much slower in primary recipient mice. Histologically, there was no significant difference in the expression of ALDH in primary tumors originating from ALDH(br) or ALDH(lo) cells. Secondary and tertiary xenografts originating from ALDH(br) grew faster and bigger than those formed by ALDH(lo) cells. In conclusion, ALDH(br) cells may have some of the traditional features of stem cells in terms of being mostly dormant and slow to divide, but require support of other cells (ALDH(lo)) to sustain tumor growth. These observations and the known role of ALDH in drug resistance may have significant therapeutic implications in the treatment of lung cancer.

The enzymatic activity of human aldehyde dehydrogenases 1A2 and 2 (ALDH1A2 and ALDH2) is detected by Aldefluor, inhibited by diethylaminobenzaldehyde and has significant effects on cell proliferation and drug resistance.

There has been a new interest in using aldehyde dehydrogenase (ALDH) activity as one marker for stem cells since the Aldefluor flow cytometry-based assay has become available. Diethylaminobenzaldehyde (DEAB), used in the Aldeflour assay, has been considered a specific inhibitor for ALDH1A1 isoform. In this study, we explore the effects of human ALDH isoenzymes, ALDH1A2 and ALDH2, on drug resistance and proliferation, and the specificity of DEAB as an inhibitor. We also screened for the expression of 19 ALDH isoenzymes in K562 cells using TaqMan Low Density Array (TLDA). We used lentiviral vectors containing the full cDNA length of either ALDH2 or ALDH1A2 to over express the enzymes in K562 leukemia and H1299 lung cancer cell lines. Successful expression was measured by activity assay, Western blot, RT-PCR, and Aldefluor assay. Both cell lines, with either ALDH1A2 or ALDH2, exhibited higher cell proliferation rates, higher clonal efficiency, and increased drug resistance to 4-hydroperoxycyclophosphamide and doxorubicin. In order to study the specificity of known ALDH activity inhibitors, DEAB and disulfiram, we incubated each cell line with either inhibitor and measured the remaining ALDH enzymatic activity. Both inhibitors reduced ALDH activity of both isoenzymes by 65-90%. Furthermore, our TLDA results revealed that ALDH1, ALDH7, ALDH3 and ALDH8 are expressed in K562 cells. We conclude that DEAB is not a specific inhibitor for ALDH1A1 and that Aldefluor assay is not specific for ALDH1A1 activity. In addition, other ALDH isoenzymes seem to play a major role in the biology and drug resistance of various malignant cells.

ALDH isozymes downregulation affects cell growth, cell motility and gene expression in lung cancer cells

BackgroundAldehyde dehydrogenase isozymes ALDH1A1 and ALDH3A1 are highly expressed in non small cell lung cancer. Neither the mechanisms nor the biologic significance for such over expression have been studied.MethodsWe have employed oligonucleotide microarrays to analyze changes in gene profiles in A549 lung cancer cell line in which ALDH activity was reduced by up to 95% using lentiviral mediated expression of siRNA against both isozymes (Lenti 1+3). Stringent analysis methods were used to identify gene expression patterns that are specific to the knock down of ALDH activity and significantly different in comparison to wild type A549 cells (WT) or cells similarly transduced with green fluorescent protein (GFP) siRNA.ResultsWe confirmed significant and specific down regulation of ALDH1A1 and ALDH3A1 in Lenti 1+3 cells and in comparison to 12 other ALDH genes detected. The results of the microarray analysis were validated by real time RT-PCR on RNA obtained from Lenti 1+3 or WT cells treated with ALDH activity inhibitors. Detailed functional analysis was performed on 101 genes that were significantly different (P < 0.001) and their expression changed by ≥ 2 folds in the Lenti 1+3 group versus the control groups. There were 75 down regulated and 26 up regulated genes. Protein binding, organ development, signal transduction, transcription, lipid metabolism, and cell migration and adhesion were among the most affected pathways.ConclusionThese molecular effects of the ALDH knock-down are associated with in vitro functional changes in the proliferation and motility of these cells and demonstrate the significance of ALDH enzymes in cell homeostasis with a potentially significant impact on the treatment of lung cancer.

Acquired functional protein s deficiency, cerebral venous thrombosis, and coumarin skin necrosis in association with antiphospholipid syndrome: report of two cases

We report for the first time an association among lupus anticoagulant, coumarin skin necrosis, and cerebral venous thrombosis. We found that serum concentrations of free functional protein S were markedly depleted because of excessive binding of protein S to C4b binding protein in two patients at the time they experienced these unusual thromboses

Characterization and Outcome of “Hard to Mobilize” Lymphoma Patients Undergoing Autologous Stem Cell Transplantation

A “hard to mobilize” patient was defined as one in whom ≥ 1 × 106CD 34, cells/kg cannot be obtained after two consecutive large volume aphereses. Forty-four consecutive Hodgkins and non-Hodgkins lymphoma patients who underwent autologous peripheral blood stem cell (PBSC) transplant treatment between June 1996 and June 1998 were included in this study. Twenty-one patients (48%) met the definition of “hard to mobilize” (Group I). All the rest of the patients (n=23) were the good mobilizers (Group II). The initial mobilization protocol for most patients was 10 μg/kg of G-CSF alone for both groups. For Group 1. 7/21 (33%) patients were unable to achieve a minimal dose of ≥ 1 × 106 CD34+ cells/kg even after a second mobilization attempt and/or bone marrow (BM) harvest (n=5). Overall. 11/21 (52%) required an additional mobilization and/or BM harvest. Only 3/21 (14%) patients were able to meet the target cell dose of ≥ 2.5×106 CD34+ cells/kg (median of 4 apheresis). In contrast. 87% of Group II achieved the target dose with a median of 2 aphereses. Predictors of poor mobilization were greater than two prior treatment regimens (p=0.038) and the WBC count (24,000/μL) on the first day of apheresis (p=0.053). Nineteen patients in Group I and all Group 11 completed treatment with a median time to engraftment of ANC500/μl of 12 and 11 days, and platelet>20× 103/μl of 31 and 13 days, respectively. Outcome analysis revealed that 6/19 patients in Group I died of relapse within one year from transplant compared with only 2/23 of Group II who died of relapse (p=0.005. log rank test). There were no treatment related deaths in either group. Independent predictive features lor “hard to mobilize” patients are a lack of significant increase in WBC count on the first day of apheresis and the number of prior treatment regimens. Poor mobilization appears to predict a worse outconic after autografting for lymphoma patients.

RNAi-mediated knockdown of aldehyde dehydrogenase class-1A1 and class-3A1 is specific and reveals that each contributes equally to the resistance against 4-hydroperoxycyclophosphamide

Purpose: Aldehyde dehydrogenases class-1A1 (ALDH1A1) and class-3A1 (ALDH3A1) have been associated with resistance to cyclophosphamide (CP) and its derivatives. We have previously reported the downregulation of these enzymes by all-trans retinoic acid (ATRA). Methods: In this study, we used siRNA duplexes as well as retrovirally expressed siRNA to knockdown one or both enzymes together in A549 lung cancer cell line in order to investigate the role of each one in mediating the resistance and the effect of the addition of ATRA. Results: The results show that significant and specific knockdown of each enzyme can be achieved and that each one contributes similarly to cell resistance to 4-hydroperoxycyclophosphamide (4-HC), an active derivative of CP. Added effects were seen when both enzymes were inhibited. The addition of ATRA also exhibited additional inhibitory effects on ALDH activity and increased 4-HC toxicity when added to single siRNA aimed at one of the enzymes. On the other hand, ATRA had minimal and insignificant additional inhibitory effects on ALDH enzyme activity when added to a combination of siRNAs against both enzymes, but still increased 4-HC toxicity beyond that seen with RNAi-mediated inhibition of both enzymes together. Conclusions: We conclude that both enzymes, ALDH1A1 and ALDH3A1 will need to be blocked in order to achieve the highest sensitivity to 4-HC. Furthermore, ATRA increases 4-HC toxicity even when added to a combination of siRNAs against both enzymes, thus suggesting additional mechanisms by which ATRA can increase drug toxicity.

Poor mobilization of peripheral blood stem cells is a risk factor for worse outcome in lymphoma patients undergoing autologous stem cell transplantation

The effect of poor blood stem cells mobilization on the outcome of autologous stem cell transplantation (ASCT) has not been well studied. Our aim is to evaluate poor mobilization as a prognostic factor in lymphoma patients undergoing ASCT. We analyzed 90 consecutive patients with Hodgkins (HD) and non-Hodgkins lymphoma (NHL) who underwent ASCT. Poor mobilization was defined as the inability to obtain ≥ 1 × 10 6 CD34+ cells/kg ideal body weight with two large volume aphereses. Patients were divided into 2 groups: group 1=poor mobilizers, and group 2=good mobilizers. The poor mobilizers received lower median transplant CD34+ cell dose (2 × 10 6 vs. 4.5 × 10 6 /kg for good mobilizers, P =0.001 ), were more heavily pretreated (P =0.01), and required higher number of aphereses for PBSC collection (P =0.0006). The median progression-free survival (PFS) in groups 1 and 2 was 10 and 41 months (P =0.04), while the median overall survival (OS) was 38 months and not reached (P =0.02), respectively. Univariate analysis showed that ≥ 3 pre-transplant treatments, CD34+ cell dose ≤ 2 × 10 6, elevated LDH before transplant, and poor mobilization were significant prognostic factors for poor PFS, while only the first three were significant for worse OS. Multivariate analysis using these same four factors revealed that number of pre-transplant treatments (HR=6.03, P =0.001), CD34+ cell dose (HR=0.1, P =0.0007) were the only independent predictive factors for worse overall outcome. In conclusion, our data show that poor mobilization could indicate poor outcome in lymphoma patients undergoing ASCT, however, it is more likely to be a reflection of the heavy pre-transplant therapy and lower CD34+ cell dose re-infused in this group of patients.