Changping Li

Lenalidomide induces complete and partial remissions in patients with relapsed and refractory chronic lymphocytic leukemia.

This study investigated the activity of lenalidomide in patients with relapsed/refractory chronic lymphocytic leukemia (CLL). Lenalidomide was given at 10 mg daily with dose escalation up to 25 mg daily. Three patients (7%) achieved a complete response (CR), one a nodular partial remission, and 10 patients a partial remission (PR), for an overall response (OR) rate of 32%. Treatment with lenalidomide was associated with an OR rate of 31% in patients with 11q or 17p deletion, of 24% in patients with unmutated V(H), and of 25% in patients with fludarabine-refractory disease. The most common toxicity was myelosuppression, and the median daily dose of lenalidomide tolerated was 10 mg. Plasma levels of angiogenic factors, inflammatory cytokines, and cytokine receptors were measured at baseline, day 7, and day 28. There was a dramatic increase in median interleukin (IL)-6, IL-10, IL-2, and tumor necrosis factor receptor-1 levels on day 7, whereas no changes were observed in median vascular endothelial growth factor levels (20 patients studied). According to our experience, lenalidomide given as a continuous treatment has antitumor activity in heavily pretreated patients with CLL.

Biologic and immunomodulatory events after CTLA-4 blockade with ticilimumab in patients with advanced malignant melanoma

T‐regulatory (TR) cells expressing cytotoxic T lymphocyte‐associated antigen‐4 (CTLA‐4) maintain peripheral immune tolerance and negatively affect host immune responses against cancer. The immunobiologic effects of ticilimumab, a human monoclonal antibody against CTLA‐4, was administered to patients with metastatic melanoma who participated in a Phase I/II clinical trial.

Expression of epithelial–mesenchymal transition-inducing transcription factors in primary breast cancer: The effect of neoadjuvant therapy†

Epithelial cancer cells are likely to undergo epithelial–mesenchymal transition (EMT) prior to entering the peripheral circulation. By undergoing EMT, circulating tumor cells (CTCs) lose epithelial markers and may escape detection by conventional methods. Therefore, we conducted a pilot study to investigate mRNA transcripts of EMT‐inducing transcription factors (TFs) in tumor cells from the peripheral blood (PB) of patients with primary breast cancer (PBC). PB mononuclear cells were isolated from 52 patients with stages I–III PBC and 30 healthy donors (HDs) and were sequentially depleted of EpCAM+ cells and CD45+ leukocytes, henceforth referred to as CD45−. The expression levels of EMT‐inducing TFs (TWIST1, SNAIL1, SLUG, ZEB1 and FOXC2) in the CD45− cells were determined using quantitative real‐time polymerase chain reaction. The highest level of expression by the CD45− cell fraction of HD was used as “cutoff” to determine if samples from patients with PBC overexpressed any EMT‐inducing TFs. In total, 15.4% of patients with PBC overexpressed at least one of the EMT‐inducing TF transcripts. Overexpression of any EMT‐inducing TF transcripts was more likely to be detected in patients with PBC who received neoadjuvant therapies (NAT) than patients who received no NAT (p = 0.003). Concurrently, CTCs were detected in 7 of 38 (18.4%) patients by CellSearch® and in 15 of 42 (35.7%) patients by AdnaTest™. There was no association between the presence of CTCs measured by CellSearch® or AdnaTest™. In summary, our results demonstrate that CTCs with EMT phenotype may occur in the peripheral circulation of patients with PBC and that NAT is unable to eliminate CTCs undergoing EMT.

Synthetic tumor-specific breakpoint peptide vaccine in patients with chronic myeloid leukemia and minimal residual disease: a phase 2 trial.

Imatinib is the current standard frontline therapy for chronic myelogenous leukemia (CML). In the majority of patients, imatinib induces a complete cytogenetic response (CCyR); however, complete molecular responses are infrequent. The Bcr‐Abl fusion creates a unique sequence of amino acids that could constitute a target for immunomodulation.

Degrasyn Potentiates the Antitumor Effects of Bortezomib in Mantle Cell Lymphoma Cells In vitro and In vivo: Therapeutic Implications

Mantle cell lymphoma (MCL) is an aggressive histotype of B-cell non–Hodgkin lymphoma that has increased in incidence over the past few decades and is incurable, usually poorly responsive to standard chemotherapy combinations, and associated with poor prognoses. Discovering new therapeutic agents with low toxicity that produce better outcomes in patients with MCL is an ongoing challenge. Recent studies showed that degrasyn, a novel small-molecule inhibitor of the Janus kinase/signal transducer and activation of transcription (JAK/STAT) pathway, exerts antitumor activity in lymphoid tumors by inhibiting key growth and survival signaling (JAK/STAT) pathways. In the present study, we found that treatment of both typical and blastoid-variant MCL cells with degrasyn in combination with bortezomib resulted in synergistic growth inhibition and apoptosis induction in vitro. The apoptosis in these cells was correlated with the downregulation of constitutive NF-κB and phosphorylated STAT3 activation, leading to the inhibition of c-Myc, cyclin D1, and bcl-2 protein expression and the upregulation of bax protein expression. In vivo, degrasyn and bortezomib interacted to synergistically prevent tumor development and prolong survival durations in a xenotransplant severe combined immunodeficient mouse model of MCL. These findings suggest that agents such as degrasyn that can pharmacologically target constitutively expressed NF-κB and STAT3 in MCL cells may be useful therapeutic agents for MCL when administered together with bortezomib. Mol Cancer Ther; 9(7); 2026–36. ©2010 AACR.

Circulating tumor cells and biomarkers: Implications for personalized targeted treatments for metastatic breast cancer

To the Editor:Metastatic breast cancer (MBC) is incurable andthe median survival of affected patients ranges from 2to 4 years with a few patients surviving for more than5 years (1–3). Palliation of metastatic disease can beachieved by considering pretreatment prognostic andpredictive factors, which can assist in choosing a ther-apy with the greatest likelihood of patient benefit (1).Another factor that may accurately predict prognosisand treatment efficacy in patients with MBC is thenumber of peripheral blood circulating tumor cells(CTC) (4), thereby providing a patient risk stratifica-tion tool.Recent studies confirmed the superiority of CTCover imaging assessment and other standard measures,such as hormone receptor status and tumor burden,for independently predicting survival (5). Thus, CTCmay indicate the existence of cancer cells that have aunique phenotype that distinguishes them from thepredominant population of cancer cells and raises thepossibility of resembling cancer-initiating stem cells.Hence, the characterization of CTC might provideinsights into the mechanisms of tumor developmentand metastases, and identify potential novel targetsfor therapy.In breast cancer, CD44(+)CD24()⁄low)Lineage())cancer-initiating cells are known to be highly tumori-genic in severe combined immunodeficient mice (6).Previous studies have shown that micrometastaticdisease detected in the bone marrow of patients withprimary breast cancer have CD44(+)CD24()⁄low)phenotype suggestive of putative cancer stem cells (7).The extension of these evaluations to cancer-initiatingcells is feasible and quite appealing for the possibletherapeutic implications. Gene expression profiles ofCTC would provide an opportunity for specific andindividualized treatment planning.We evaluated CTC from 20 women enrolled in aprospective clinical trial at The University of TexasM. D. Anderson Cancer Center for transcripts ofestrogen receptor (ER), progesterone receptor (PgR),and human epidermal growth factor receptor-2 (HER-2). Such biomarkers’ expression in CTC is currentlynot considered in the selection of treatment regimens,and hence we compared the expression patterns ofCTC with the expression of these proteins by the pri-mary tumor and metastatic lesions. Tumor character-istics, types of treatment, and responses for the 20women with MBC who contributed samples for thisanalysis are shown in Table 1. The median number ofCTC was 2.5 (range, 0–168). Four (20%) patients had0 CTC, eight (40%) patients had 1–4 CTC, and theother eight (40%) patients had ‡5 CTC. Of theprimary tumors, 16 (80%) were ER+ and 11 (55%)were PgR+, only three (15%) showed amplification ofHER-2⁄neu. Biopsies of metastatic lesions were avail-able in 15 of the 20 patients with recurrent disease(Table 1). Nine (60%) of the metastatic tumors wereER+, seven (47%) were PgR+, and three (20%)showed amplified HER-2⁄neu. Expression patterns ofER (kappa = 0.71; p = 0.004), PgR (kappa = 0.60;p = 0.02), and HER-2 (kappa = 0.61; p = 0.047) weresimilar in the primary and metastatic tumors.In addition to ER, PgR, and HER-2, we examinedthe expression of two other genes of interest, mamma-globin (MGB) and Notch-1 in CTC. MGB levels inprimary breast tumors inversely correlate with tumoraggressiveness and axillary node invasion (8). Notch-1can be aberrantly activated in human breast cancercells (9) and may regulate the self-renewal of tumori-genic stem cells. Therefore, Notch-1 may represent agenetic biomarker of a subset of breast cancer stem

An epigenetic chromatin remodeling role for NFATc1 in transcriptional regulation of growth and survival genes in diffuse large B-cell lymphomas

The nuclear factor of activated T cells (NFAT) family of transcription factors functions as integrators of multiple signaling pathways by binding to chromatin in combination with other transcription factors and coactivators to regulate genes central for cell growth and survival in hematopoietic cells. Recent experimental evidence has implicated the calcineurin/NFAT signaling pathway in the pathogenesis of various malignancies, including diffuse large B-cell lymphoma (DLBCL). However, the molecular mechanism(s) underlying NFATc1 regulation of genes controlling lymphoma cell growth and survival is still unclear. In this study, we demonstrate that the transcription factor NFATc1 regulates gene expression in DLBCL cells through a chromatin remodeling mechanism that involves recruitment of the SWItch/Sucrose NonFermentable chromatin remodeling complex ATPase enzyme SMARCA4 (also known as Brahma-related gene 1) to NFATc1 targeted gene promoters. The NFATc1/Brahma-related gene 1 complex induces promoter DNase I hypersensitive sites and recruits other transcription factors to the active chromatin site to regulate gene transcription. Targeting NFATc1 with specific small hairpin RNA inhibits DNase I hypersensitive site formation and down-regulates target gene expression. Our data support a novel epigenetic control mechanism for the transcriptional regulation of growth and survival genes by NFATc1 in the pathophysiology of DLBCL and suggests that targeting NFATc1 could potentially have therapeutic value.

Abstract 2854: Targeting constitutive NF-kB activation through Bruton's tyrosine kinase (Btk) and the proteasome in mantle cell lymphoma

Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin lymphoma (NHL) with poor prognoses; novel agents are needed for its therapy. Bruton9s tyrosine kinase (Btk) has been identified as an essential kinase for B-cell survival and it is activated through the B-cell receptor (BCR) pathway. Btk has recently emerged as a promising target in MCL, as demonstrated by recent clinical trials on the Btk inhibitor PCI-32765 (Pharmacyclics, Sunnyvale, CA), suggesting that elucidating critical signaling pathways emanating through Btk will hold an important key to deciphering the pathogenesis of MCL that can lead to the development of more effective targeted therapies. In this study, we showed that Btk is constitutively phosphorylated in most MCL cell lines except Rec1 and DB SP53 and is variable among primary cells from patients. We demonstrated that knockdown of Btk by siRNA diminished Btk expression, reduced constitutive NF-kB activation by luciferase assays, leading to the cell growth inhibition and induction of apoptosis in MCL cell lines. MCL cells treated with the Btk inhibitor PCI-32765 effectively inhibits Btk activity, leading to reduced MCL cell growth with IC 50 values range from 2-6 uM in Mino, Jeko1, Z138 and JMP1. Interestingly, the IC 50 value in DB SP53, which lacks both phosphorylated Btk and membrane immunoglobulins, is 35 uM, suggesting that BCR signaling is not active in these cell lines. PCI-32765 also induced caspase-dependent apoptosis in a dose- and time-dependent manner in representative MCL cell lines and in patient primary cells. We further demonstrated that PCI-32765 down-regulates NF-kB activity through both, the canonical and alternative NF-kB pathways. Since previous studies have indicated synergy between proteasome inhibitors and tyrosine kinase inhibitors, we evaluated whether there is synergism between PCI-32765 and the next generation proteasome inhibitor Carfilzomib (Onyx Pharmaceuticals, South San Francisco, CA). Our data suggest potential synergy between Carfilzomib and PCI-32765 in represented MCL cell lines in terms of inhibiting cell growth and induction of apoptosis. Both compounds also synergize to inhibit NF-kB activation in MCL cells. In summary, our data suggest that Btk is a key survival kinase in MCL and strategic targeting of growth/survival Btk-mediated NF-kB pathways with novel therapeutic agents such as PCI-32765 should provide a novel therapy regimen for MCL patients. Combining PCI-32765 with the proteasome inhibitor Carfilzomib can synergize its effect in MCL and may be a useful therapeutic strategy, particularly for patients with relapsed/refractory MCL. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2854. doi:1538-7445.AM2012-2854

Abstract 218: The hexosamine biosyntheic pathway and O-linked glycosylation for targeted therapy in diffuse large B-cell lymphoma

Mammalian cells fuel their growth and proliferation through the catabolism of two main substrates: glucose and glutamine. Both nutrients are required for the synthesis of glucosamine, the precursor substrate of the hexosamine biosynthetic pathway. The hexosamine signaling pathway terminating in O-linked N-acetyl glucosamine (O-GlcNAc) cycling has been implicated in cellular signaling cascades and regulation of transcription factors involved in cancer biology. Biological functions of the hexosamine biosynthetic signaling pathways need elucidation, to determine whether altered O-GlcNAc metabolism plays a significant role in hematologic tumors such as diffuse large B-cell lymphoma (DLBCL), and utilize this bifunctional pathway as a targeted therapeutic strategy in DLBCL. We have identified a key enzyme of the hexosamine biosynthetic pathways to be highly-expressed in DLBCL cell lines and patient tumor cells. In contrast to normal circulating and tonsillar B cells, DLBCL cells expressed high levels of the terminating enzyme O-GlcNAc transferase (OGT). OGT mRNA expression is highly expressed in DLBCL in comparaison to other cancers. We discovered that several key growth and survival transcription factors, such as NF-kB and NFAT, known to be highly-activated in DLBCL, are linked to the hexoasmine biosynthetic pathway. We demonstrated that both NF-kB (p65) and NFATc1 directly associated with OGT, and down-regulation of OGT by siRNA inhibits these transcription factors activation, suggesting that both NF-kB-p65 and NFATc1 require O-GlcNAc glycosylation by OGT for their activation. These results suggest that the hexosamine pathway is highly active and utilized in DLBCL, and that exploiting this bi-functional pathway(s) as a therapeutic approach is feasible. We have previously developed an imaging agent, 99mTc-ethylenedicysteine-glucosamine (99mTc-EC-G) because EC-G mimics phosphorylated N-acetylglucosamine. ECG treatment in DLBCL cells enhances p65 and NFATc1 nuclear translocation. For therapeutic strategies, we developed metallic unlabeled Platinum (Pt) derivatives-EC-G as potential therapeutic agents. Pre-clinical in vitro studies have shown that our two lead compounds, Pt-9 and Pt-DACH-EC-G effectively inhibit lymphoma cell growth and induce apoptosis. These lead compounds can also induce DNA damage in DLBCL cells, through the up-regulation of phosphorylated histone 2AX (pH2AX), leading to the disruption of p65 and NFATc1 binding to DNA. This data importantly demonstrates that the hexosamine biosynthetic pathway is linked to key growth and survival pathways involved in the pathophysiology of DLBCL. Targeting these pathways with novel platinum EC-G compounds as a theranostic approach should lead to new, more effective treatments and diagnosis for DLBCL, particularly for relapsed/refractory DLBCL. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 218. doi:1538-7445.AM2012-218

Abstract A129: Development of turmerax therapeutic compounds in aggressive, refractory B cell non-Hodgkin's lymphoma.

Acquired chemoresistance (ACR) is currently the most important cause of treatment failure and early mortality in DLBCL, arguably the most important but greatest unmet need in lymphoma therapy today. Diffuse Large B cell Lymphoma (DLBCL), the most common human lymphoma, comprises a genetically and clinically diverse group of aggressive B cell non-Hodgkin lymphomas (NHL-B), among a small group of important human cancers increasing in incidence in the US over the last four decades. NHL-B are the fifth most common cancers in the USA (>62,000 new cases/20,000 deaths) expected in 2011. The molecular biologic and genetic basis of the patho-physiology of these important lymphoid tumors is still mostly unresolved. Relapsed/refractory (r/rDLBCL) DLBCL is one of the most difficult scientific challenges and severe unmet therapeutic needs in clinical oncology today. This is due largely to 1.) very drug resistant tumor cells with very poor responses ( 1000x more effective than curcumin in inhibiting DLBCL growth and survival in vitro, and show no toxicities in normal peripheral blood lymphocytes. Liposomal-TMX (L-TMX) also targets multiple growth and survival signaling pathways, such as NF-kB and AKT, and key cellular regulatory proteins in drug resistance (MDR) in r/r DLBCL. We have also shown in vivo that L-TMX increases in survival time with decreases in lymphoma tumor burden in preliminary studies in SCID/MCL xeno-transplant (XT-SCID) models, without evidence of significant host toxicities. The development of our new agent nano-liposomal Turmerax, has provided a multi-targeted, non-toxic nano-therapeutic small molecule with the critical growth/survival (G/S) targeting specificities similar to natural product therapeutic agents (curcumin) but without the many foibles involving solubility, bioavailability, and poor in vivo potency problems, by providing a well-tolerated, well-delivered (in vivo) effective small molecule therapeutic agent, showing very promising preliminary activities on r/r DLBCL in xeno-transplant human DBLCL models, that appears to be an excellent candidate for future clinical trials. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A129.