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.

Overcoming immune tolerance against multiple myeloma with lentiviral calnexin-engineered dendritic cells.

The key to successful cancer immunotherapy is to induce an effective anticancer immunity that will overcome the acquired cancer-specific immune tolerance. In this study, we found that dendritic cells (DCs) from multiple myeloma (MM) patients suppressed rather than induced a cancer cell-specific immune response. We demonstrated that CD4(+)CD25(high) T cells from MM patients suppressed the proliferation of activated peripheral blood lymphocytes.

Heterogeneity of aldehyde dehydrogenase expression in lung cancer cell lines is revealed by Aldefluor flow cytometry-based assay.

Background: We have been interested in studying the roles of two aldehyde dehydrogenases in the biology of lung cancer. In this study, we seek to apply Aldefluor flow cytometry-based assay for the measurement of aldehyde dehydrogenase (ALDH) activity in lung cancer cell lines, which may become a new tool that will facilitate our continued research in this field.

Experimental Design: Several established lung cancer cell lines were used, including A549 cell line expressing siRNA against aldehyde dehydrogenase class-1A1 (ALDH1A1).

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.

Inhibition of simian immunodeficiency virus by foamy virus vectors expressing siRNAs.

Viral vectors available for gene therapy are either inefficient or suffer from safety concerns for human applications. Foamy viruses are non-pathogenic retroviruses that offer several unique opportunities for gene transfer in various cell types from different species. In this report, we describe the use of simian foamy virus type 1 (SFV-1) vector to examine the efficacy of therapeutic genes.

Retinoic acid down-regulates aldehyde dehydrogenase and increases cytotoxicity of 4-hydroperoxycyclophosphamide and acetaldehyde.

Multiple prior studies have identified aldehyde dehydrogenases (ALDH) that are capable of oxidizing retinal to retinoic acid. In this study, we test the hypothesis that the accumulation of intracellular retinoic acid may lead to the suppression of ALDH expression and thus increase cytotoxicity to 4-hydroperoxycyclophosphamide (4-HC) in vitro. Mainly A549, but also other lung cancer cell lines, were used in our experiments, with the former having high levels of two ALDH isozymes expressed.

Potent anti-tumor effects of an active site mutant of human manganese-superoxide dismutase. Evolutionary conservation of product inhibition.

Mn-SOD serves as the primary cellular defense against oxidative damage by converting superoxide radicals (O(2)(-)) to O(2) and H(2)O(2). A unique characteristic of this mitochondrial anti-oxidant enzyme is the conservation from bacteria to man of a rapidly formed product inhibited state. Using site-directed mutagenesis, we have generated an active site mutant (H30N) of human Mn-SOD, which exhibits significantly reduced product inhibition and increased enzymatic efficiency.

Overexpression of manganese superoxide dismutase promotes survival in cell lines after doxorubicin treatment.

Overexpression of manganese superoxide dismutase (MnSOD) has been postulated as one possible mechanism of protection from oxidative damage and free radicals. Doxorubicin treatment induces oxygen free radicals, leading to cytotoxicity and myelosuppression. The present study was performed to determine whether over-expression of MnSOD may play a role in resistance to doxorubicin.

Transduction of umbilical cord blood CD34+ NOD/SCID-repopulating cells by simian foamy virus type 1 (SFV-1) vector.

Foamy viruses are nonpathogenic retroviruses that offer unique opportunities for gene transfer into various cell types including hematopoietic stem cells. We used a simian foamy virus type 1 vector (SFV-1) containing a LacZ reporter gene with a titer of 1-5 x 10(6) viral particles/ml that was free of replication-competent retrovirus to transduce human umbilical cord blood CD34+ cells. Transduced CD34+ cord blood cells were transplanted into NOD/SCID mice and plated in serum-free methylcellulose culture to determine the transduction efficiency of human hematopoietic progenitor cells.