Biomedical subjects

Shantaram S Joshi

Publications and source records attributed to Shantaram S Joshi.

11 recordsLinked to original sources

PubMed2007

Bulky lymphadenopathy with poor clinical outcome is associated with ATM downregulation in B-cell chronic lymphocytic leukemia patients irrespective of 11q23 deletion.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common B-cell leukemia among older populations in Western countries. The clinical course of B-CLL is heterogeneous: in some patients the disease course is indolent, in others it is aggressive. The B-CLL subgroups with chromosome 11q23 deletion have been associated with aggressive disease course involving ATM deletion, extensive bulky lymphadenopathy (BLA), and inferior clinical outcome. Using real-time reverse transcriptase-polymerase chain reaction, we found that ATM was consistently underexpressed in B-CLL patients with BLA, irrespective of 11q23 deletion status. In addition, B-CLL patients who presented with BLA had a significantly shorter time to treatment (2 months) than did patients without BLA (74 months). Moreover, gene expression analysis in B-CLL patients with and without BLA revealed differences in expression for genes involved in apoptosis, cell cycle, and cell adhesion. These results indicate an association between BLA and reduced expression of ATM, suggesting a role for ATM in disease progression in B-CLL.

Ataxia Telangiectasia Mutated Proteins↗

PubMed2006

11q22.3 deletion in B-chronic lymphocytic leukemia is specifically associated with bulky lymphadenopathy and ZAP-70 expression but not reduced expression of adhesion/cell surface receptor molecules.

The presence of chromosome abnormalities promotes tumor progression in B-chronic lymphocytic leukemia (CLL). However, the molecular pathways that are relevant to tumor progression remain unclear. In this study, we screened for common chromosome abnormalities [13q14 del, 11q22.3 (ATM) del, 17p13 (p53) del and trisomy 12] by fluorescent in situ hybridization in 40 B-CLL patients. Each of the four chromosome abnormality groups was compared to several clinical factors related to lymphocyte behaviour in CLL. The 11q22.3 (ATM) deletion group was significantly associated with the presence of bulky abdominal/mediastinal lymphadenopathy (P = 0.014). We hypothesized that this phenotype would be associated with an altered transcription pattern of genes. Class comparison analysis by significance analysis of microarrays on a subset of CLL samples (n = 14) indicated that a number of cell surface receptor and adhesion related genes were under-expressed in the 11q22.3 deletion group (CD44, CD11a, PTPRC, CD79a, chemokine ligand 17 and chemokine receptor type 6). The presence of additional prognostic factors, such as CD38 and immunoglobulin heavy chain variable region mutational status, may also influence the transcriptional pathways between the two groups. Therefore, we employed a novel analysis technique for the correlation of log(2) gene expression ratios with the percentage of each tumor that carried the 11q22.3 deletion. Using Spearman's correlation, ZAP-70, chemokine ligand 17, BSAP (PAX5), CD7, LAG3 and PTPR6 were significantly correlated with the percentage of cells with the 11q22.3 deletion. However, the down-regulation of cell surface receptors and adhesion molecules observed by class comparison could not be confirmed to be specific for the 11q22.3 deletion by this method.

Cell Adhesion Molecules↗

PubMed2006

Ortho-quinones of benzene and estrogens induce hyperproliferation of human peripheral blood mononuclear cells.

Benzene is a known leukemogen. It has been hypothesized that benzene and natural estrogens initiate cancer by forming ortho-quinones (catechol quinones) that react with DNA in cells. These quinones form depurinating DNA adducts that generate the mutations leading to cancer. This study examined whether the treatment of normal human peripheral blood mononuclear cells with the ortho-quinones of benzene or estradiol would form DNA adducts and elicit an alteration in the proliferation of these cells. Both estradiol-3,4-quinone and benzene ortho-quinone formed depurinating DNA adducts and significantly increased the mitogen-induced proliferation of normal blood mononuclear cells. Immunophenotyping of the estradiol-3,4-quinone-treated blood cells indicated that monocyte/macrophage, natural killer and T-cells were particularly prone to hyperproliferation. Thus, DNA damage induced by the ortho-quinones of benzene and estradiol may promote the growth of human blood mononuclear cells, including those that appear in large numbers in leukemia and lymphoma.

Benzene↗

PubMed2006

Genomic abnormalities in chronic lymphocytic leukemia influence gene expression by a gene dosage effect.

This work describes the identification and impact of somatic genomic abnormalities in human chronic lymphocytic leukemia (CLL). Using molecular cytogenetics (FISH) and G-banding cytogenetic analysis, chromosome abnormalities were detected in 37 of 46 (80.4%) CLL patients. 13q14 deletion was the most common finding followed by trisomy 12 and 11q22.3 deletion. 17p13 deletion was also detected as were several less frequent chromosome abnormalities. The presence of these abnormalities significantly influenced the period of treatment-free survival as well as other clinical characteristics. In particular, CLL samples with trisomy 12 and 11q22.3 deletion were associated with shorter treatment-free survival. In order to identify the under-lying molecular differences among CLL subgroups with different chromosome abnormalities, gene expression profiling was performed on a custom DNA microarray consisting of 10,000 human gene-specific oligonucleotides. A gene dosage effect was observed where the expression of genes at the genetic loci of the sites of the somatic genomic abnormality was altered in a fashion according to the type of genomic change. This phenomenon was particularly evident in CLL samples with trisomy 12 and 17p13 deletion. Thus, this study demonstrates that genomic abnormalities influence gene expression in CLL by a dosage effect.

Adult↗

PubMed2006

Dendritic cell-based therapy for mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a B cell malignancy that is resistant to conventional therapies. High-dose therapy (HDT) followed by stem cell transplantation is effective in inducing remission. However, residual lymphoma cells are eventually responsible for the subsequent relapse. Effective therapeutic strategies to eliminate the residual lymphoma is required. In this study, we have examined the in vitro and in vivo anti-lymphoma effects of MCL-specific cytotoxic T lymphocytes (CTLs) that were generated using dendritic cells (DCs) fused with MCL cells for immunostimulation. Dendritic cells were generated in vitro using dendritic cell-specific medium, cytomorphology, immunophenotypes and functional capabilities of the generated DCs were studied. Such DCs were then used for the preparation of DC-MCL hybrids and the DC-MCL hybrids were used to generate CTLs against MCL cells and tested for their MCL-specific cytotoxicity in vitro and in vivo. The CTLs demonstrated MCL-specific cytotoxicity in vitro against GRANT-519, a human MCL cell line. These CTLs did not show significant effect against an irrelevant target. To test the in vivo therapeutic effect of DC-MCL hybrid-stimulated CTLs, a preclinical model consisting of NOD-SCID mice bearing Granta 519 was developed. The NOD-SCID mice bearing Granta-519 MCL tumors were treated with DC-MCL hybrids and the same donor T lymphocytes. There was an increase in survival (60% in mice treated with DC-MCL hybrid approach compared to 20% in the untreated group). Histological analysis of liver from control and treated mice displayed a decrease in the number of the tumor nodules in the treatment group. These results indicate the potential of DC-based therapy for the treatment of MCL.

Animals↗

PubMed2005

Unique gene expression and clinical characteristics are associated with the 11q23 deletion in chronic lymphocytic leukaemia.

Chromosome abnormalities influence prognosis and tumour progression in B-cell Chronic Lymphocytic Leukaemia (CLL). This study sought to determine whether these different disease subgroups were associated with unique gene expression patterns. Thirty-four cases of CLL were screened for the 11q23, 13q14, 17p13 deletions, and trisomy 12 by fluorescence in situ hybridization (FISH). Expression of 205 cell signalling and apoptosis genes were compared by cDNA array among cases with different chromosome abnormalities. A majority of the statistically differentially expressed genes were present in the 11q23 deletion group by hierarchical clustering. CDC2, a serine/threonine kinase, was overexpressed in the 11q23 deletion group (P = 0.0004) and confirmed by Taqman real-time polymerase chain reaction. Several other genes associated with cell signalling were overexpressed in the 11q23 deletion group. A strong overall correlation existed between the presence of different chromosome abnormalities and a number of prognostic factors including immunoglobulin heavy chain variable region mutation status (P = 0.011), time to treatment (P = 0.025) and lymphocyte doubling time (P = 0.034). This study confirmed the prognostic impact of chromosome abnormalities identified by FISH in CLL, particularly the 11q23 deletion and trisomy 12. In addition, the 11q23 deletion group was associated with a unique gene expression pattern involving cell signalling and apoptosis genes.

Adult↗

PubMed2004

Cytotoxicity of cord blood derived Her2/neu-specific cytotoxic T lymphocytes against human breast cancer in vitro and in vivo.

The Her2/neu oncogene encodes a transmembrane protein with homology to the epidermal growth factor receptor. Overexpression of this gene contributes to the aggressiveness of breast cancer and poor prognosis. Therefore, Her2/neu is an ideal target molecule for generating effective cytotoxic T lymphocytes (CTLs) against breast cancers. This study reports on the generation of Her2/neu-specific CTL from umbilical cord blood mononuclear cells (UCBC) using dendritic cells primed with Her2/neu-derived peptide (KIFGSLAFL, E75) for immunostimulation. The CTLs showed specific cytotoxicity to Her2/neu high expressing MDA-453 but not toward Her2/neu low expressing MDA-231 human breast cancer cells. Similarly generated CTLs stimulated with irrelevant peptide pulsed dendritic cells did not show significant cytotoxicity towards breast cancer targets. The phenotypes of cells in culture showed high percentage of CD3+, CD4+ and CD8+T cells as determined by flow cytometry. However, the antibody mediated blocking assay demonstrated that only HLA-Class I restricted CD8+ cells are involved in the cytotoxicity. Furthermore, in vivo studies showed that treatment of SCID mice bearing MDA-453 tumor with Her2/neu-specific CTLs resulted in significant inhibition of tumor growth compared to untreated tumor bearing control mice. These results demonstrate that human umbilical cord blood mononuclear cells are a good source for generating Her2/neu-specific CTLs against human breast cancer both in vitro and in vivo.

Antigens, Neoplasm↗

PubMed2003

Lymphodepleting effects and safety of pentostatin for nonmyeloablative allogeneic stem-cell transplantation.

Nonmyeloablative allogeneic stem-cell transplantation (alloNST) is the focus of investigations searching for less-toxic transplantation regimens. We report studies on the kinetics of lymphodepletion and safety of pentostatin (PT) conditioning in alloNST. Patients with hematologic malignancy received mobilized blood from human leukocyte antigen-matched related (n=4) or unrelated (n=8) donors. PT 4 mg/m2 was administered on days -21, -20, and -19 and 200 cGy of total-body irradiation was administered on day -1, followed by cyclosporine A and mycophenolate mofetil. Mononuclear cell adenosine deaminase after PT was inhibited 84%. The absolute CD3+ cells decreased significantly by day -7 (49%) and CD19+ cells declined 92% by day -1. CD4+ cells were depressed more than CD8+ cells. Neutrophils and monocytes were minimally affected by PT. Median posttransplant peripheral blood chimerism on day 70 showed 95% donor leukocytes and 82.5% donor CD3 lymphocytes. PT demonstrated lymphodepleting effects and promising safety, supporting alloNST as early as 7 days after initiation of PT.

Adult↗

PubMed2002

Increased apoptosis in B-chronic lymphocytic leukemia cells as a result of cyclin D3 down regulation.

B-cell chronic lymphocytic leukemia (CLL) is a clonal B cell malignancy of morphologically mature, functionally immature B cells. B-cell CLL cells are known to be resistant to killing by anticancer and other agents. This resistance is associated with alterations in apoptosis and cell cycle regulated genes. In our earlier studies, we have demonstrated that CLL cells have differential expression of genes that are associated with apoptosis and cell cycle regulation, including elevated expression of Bcl-2, DAD-1, Cyclin D3 and cyclin dependent kinase 4 inhibitor. Therefore, in this study, in an attempt to study the role of Cyclin D3 in the resistant behavior of CLL cells, Cyclin D3 was down regulated using antisense oligonucleotide (AS-ODN) in WSU-CLL, a human CLL cell line. The down regulation of Cyclin D3 was confirmed by RT-PCR and flow cytometry techniques. The Cyclin D3 expression down-regulated WSU-CLL cells were then tested for their susceptibility to fludarabine, a chemotherapeutic agent. Our results showed that the Cyclin D3 expression down-regulated WSU-CLL cells were more susceptible to fludarabine mediated killing. Following treatment with fludarabine, there was a significant increase in the number of cells undergoing apoptosis in Cyclin D3 expression down-regulated WSU-CLL cells as determined by Annexin-V assay, cell cycle analysis for DNA content, and cytomorphology. Thus, our results indicate Cyclin D3 down regulation increases the killing of WSU-CLL cells with fludarabine by increasing the number of cells undergoing apoptosis.

Annexin A5↗

PubMed2002

Comparison of phenotypic and functional dendritic cells derived from human umbilical cord blood and peripheral blood mononuclear cells.

Dendritic cells (DC) are important accessory cells that are capable of initiating an immune response. Generation of functional DC has potential clinical use in treating diseases such as cancer. In this report, we have demonstrated the generation of functional DC from mononuclear cells isolated from human umbilical cord blood cells (UCBC) and peripheral blood cells (PBC) using a defined medium Prime Complete Growth Medium (PCGM) (GenePrime LLC, Gaithersburg, MD). DC generated using PCGM showed the typical phenotype of DC as determined by flow cytometry and electron microscopy. Further analysis of the DC using confocal microscopy showed localization of the antigen and major histocompatibility complex (MHC) molecules in the cytoplasm 3-5 days following tumor antigen loading into DC. Subsequently, the tumor antigen-MHC complex was localized on the surface of DC. DC generated from UCBC or PBC also increased (p < 0.001) the allogeneic mixed lymphocyte reaction, confirming their immune accessory functions compared to a control mixed lymphocyte reaction (MLR) without DC added. Interestingly, DC generated using PCGM medium also significantly enhanced the hematopoietic colony (CFU-C)-forming ability. Furthermore, addition of 5% DC derived from cord blood loaded with tumor antigen also significantly (p < 0.001) increased peripheral and cord blood-derived antigen-specific cytotoxic T lymphocyte (CTL)-mediated killing of human leukemic cells (K562) and breast cancer cells (MDA-231). Thus, these results show that functional DC generated from cord blood using a defined medium are a useful source of accessory cells for augmenting CTL-mediated cytotoxicity and have potential use in cellular therapy for human leukemia and breast cancer.

Antigen Presentation↗

PubMedDate not supplied

Enhanced in vitro and in vivo cytotoxicity of umbilical cord blood cells against human breast cancer following activation with IL-15 and colony stimulating factors.

BACKGROUND: Cord blood mononuclear cells (MNC) are a rich source of precursor cytotoxic effector cells. Earlier we have shown that interleukin-2 (IL-2)-activated MNC from cord blood have significant cytotoxic activity against human leukemia and breast cancer cells in vitro and in vivo, compared to MNC from peripheral blood. MATERIALS AND METHODS: In order to further improve the antitumor cytotoxic ability of cord blood MNC, IL-2 was combined with IL-15 and colony stimulating factors GMCSF, G-CSF and M-CSF for the activation. The activated cells were examined for their cytotoxic effects in vitro against human breast cancer cell lines MDA-231, MDA453 and SKB43 and in vivo against MDA-231 grown in SCID mice. Phenotypes of these activated cells were determined using flow cytometry. The expression of immune response related genes in activated cells was measured using RT-PCR techniques. RESULTS: There was a significant increase in cytotoxicity of the effector cells activated with IL-2, IL-15 and some colony stimulating factors compared to cells activated with each of these cytokines alone or other combinations. Our results demonstrated the increase in cytotoxicity appears to be due to: 1) increase in CD56-positive cytotoxic cells; 2) cytokine/cytotoxic factors produced by the effector cells, such as Interferon-7 and Perforin; 3) stimulation by accessory cells, such as dendritic cells. In vivo administration of in vitro-activated cord blood cells into SCID mice bearing MDA-231 tumors reduced the number of metastases and increased survival compared to untreated tumor bearing controls. CONCLUSION: The combination of IL-2 with IL-15 and CSF is better for the activation of cord blood effector cells than to IL-2 alone.

Animals↗