The treatment of Hodgkin lymphoma continues to be based on combination chemotherapy and radiation therapy. Although this treatment strategy produces a high cure rate, short- and long-term toxic ...effects continue to be problematic for young cured patients. In this review we focus on emerging novel therapies using small molecules that target specific survival pathways in the cancer cells. This approach is aimed at improving the cure rate while reducing treatment-related toxicity.
Cancer cells exhibit a high rate of glycolysis, which leads to a stringent dependence on extracellular glucose for maintaining intracellular ATP levels. Leukemic cells infiltrating bone marrow have ...been shown to be markedly hypoxic compared to normal bone marrow cells, and stimulation of glycolysis is thought to be an adaptive mechanism to hypoxia. The serine/threonine kinase AKT promotes continued cell growth and metabolism by increasing glucose uptake, stimulating glycolysis and ATP production, at least in part via mTOR-dependent stabilization of HIF1-α. The purpose of this study was to investigate the role of mTOR signaling in the regulation of glycolytic activity of leukemic cells growing under high glucose or hypoxic conditions. Culture of Jurkat cells or primary ALL lymphoblasts in hypoxia (1% O2) resulted in robust induction of HIF-1α protein level which was significantly higher in high glucose conditions. This induction was blocked by inhibition of mTOR signaling, in association with decreased HK-2 mRNA and Glut-1 mRNA/protein expression. Likewise, hypoxia induced lactic acid production, a surrogate marker of glycolysis, and this induction was prevented by RAD001 (p=0.01). This data suggest that PI3K/AKT/mTOR pathway critically controls HIF-1α-dependent upregulation of glucose transport and glycolysis under in leukemic cells growing under pro-glycolytic conditions. We next examined the relationship between enhanced glycolytic activity and chemosensitivity to Doxorubicin. Doxorubicin (25ng/ml) efficiently inhibited growth of Jurkat cells under normoxic conditions supplemented with 4 mM glucose (equivalent of 72mg/dl). In contrast, Doxorubicin was approximately 50% less effective when cells were cultured either in high (14mM, equivalent of 252mg/dl) glucose or under hypoxia with low- or high-glucose supplementation. Inhibition of mTOR signaling strikingly enhanced effects of Doxorubicin resulting in complete inhibition of growth, and this effect was apparent only under high glucose conditions. We next examined effects of RAD001 in samples from 11 patients' samples from newly diagnosed B-ALL patients growing under high/low glucose in hypoxic or normoxic conditions. RAD001 alone did not induce apoptosis in ALL cells (p>0.05). In contrast, inhibition of mTOR signaling significantly enhanced Doxorubicin-induced apoptosis in 8 samples, with highest sensitization observed in high glucose environment (specific apoptosis, Doxorubicin alone, 5.6%, RAD001 7.7%, RAD001+Doxorubicin 22.4%, p<0.02). In conclusion, blockade of mTOR-dependent HIF-1α and its downstream target Glut-1 efficiently promotes chemosensitivity of ALL cells under pro-glycolytic conditions. Hence, mTOR inhibition or blockade of HIF-1α-mediated glycolysis may play an important role in chemosensitization and improved outcomes in ALL.
Purpose: HL patients (pts) with recurrent refractory disease after stem cell transplant have poor prognosis and are considered not curable with currently available salvage therapy. Novel therapeutic ...agents are needed for this pt population. MGCD0103 is an oral isotype-selective inhibitor of histone deacetylases (HDACS) with significant biological activity in preclinical models of hematopoietic cancers. Thymus- and activation-regulated chemokine (TARC) which is highly expressed by Reed-Sternberg cells in HL was one of the biomarkers assessed in this study.
Methods: A phase II trial of MGCD0103 is ongoing in pts with relapsed/refractory classical HL. MGCD0103 was dosed at 110 mg 3×/week in 4-week cycles, with dose reductions to 85 and 60 mg in case of toxicities. Eligibility criteria included prior treatment with autologous and/or allogeneic stem cell transplant, at least one target lesion ≥ 2 cm, ECOG performance status of 0–1 and platelet counts of at least 25,000/mL. Tumor responses were determined every 8 weeks. Serum TARC levels were determined by ELISA using blood samples that were obtained prior to starting therapy and 8 days after therapy.
Results: To date, 27 pts of a planned 12–35 have been enrolled (median age, 29 yrs; range, 20–62 yrs). Among 20 evaluable pts, 2 (10%) had CRs and 6 (30%) had PRs, for an OR rate of 40% (median time to response, 2 cycles). In addition, one pt (5%) had SD (<50% reduction) for ≥ 6 m. The rate of disease control (CR + PR + SD ≥ 6 m) was 45%. As assessed by CT scans, 15 pts (75%) exhibited tumor reductions: 12 (60%) had reductions of > 30%, and 8 (40%) had reductions of ≥ 50%. Serum TARC levels were determined in 15 paired samples. After one week of therapy serum TARC levels were decreased by at least 40% in 5 pts, and all achieved major clinical responses (PR+CR). Seventeen of 25 pts required dose reductions for management of toxicities. The most common drug-related non-hematological toxicities were nausea (11/25), fatigue (10/25), vomiting (8/25), diarrhea (7/25), anorexia (4/25), pneumonia (3/25), abdominal pain (3/25) and weight loss (3/25). There were 2 deaths on study, both in heavily pretreated pts, one of unknown cause in a woman with h/o mantle XRT, BMT, suffering from significant GI AEs and the other of neutropenic fever, pneumonia and sepsis in a man with severe marrow compromise at baseline. Six pts experienced grade 3 or 4 toxicity. Of these, only pneumonia occurred in > 1 pt. Dose modification was effective in managing most toxicities. HDAC inhibition was observed in PBMCs from the majority of evaluable pts. By using microarray expression analysis, transcriptional profiles of PBMCs from limited pts with/without clinical response were compared.
Conclusions: Interim results from this ongoing trial suggest that single-agent MGCD0103 demonstrates significant anti-tumor activity in relapsed/refractory classical HL and is well tolerated, with dose modifications used as necessary to manage toxicities. Preliminary data also suggests that early decrease in serum TARC levels may predict response to therapy.
Alemtuzumab, a monoclonal anti-CD52 antibody, has shown high efficacy against lymphoproliferative disorders such as B-cell chronic lymphocytic leukemia (B-CLL). However, its use results in a profound ...immunosuppression with decrease of T lymphocytes leading to increased susceptibility to infections. The aim of our study was to assess the in vitro cytotoxic effect of alemtuzumab on normal T and neoplastic B lymphocytes obtained from B-CLL patients.
Peripheral blood mononuclear cells (PBMC) from 12 B-CLL patients (5 at diagnosis and 7 previously treated) were collected and treated in vitro with alemtuzumab (10 μg/ml) and autologous serum in the culture as complement source. Spontaneous and alemtuzumab-induced apoptosis were quantified in T (CD3+) and B (CD20+) lymphocytes after 24 hours using an annexin-V flow cytometry based asssay.
Alemtuzumab was able to induce apoptosis on both B and T lymphocytes of CLL patients. However, the cytotoxic activity on neoplastic B cells was comparable in all cases analyzed, irrespective of stage or previous treatments. Spontaneous apoptosis of B CLL cells was also comparable in all studied samples.
On the contrary, the activity of alemtuzumab on normal T lymphocytes varied according to stage of disease and previous treatment. In early stages (0–I) alemtuzumab induced apoptosis in 19 % of T cells vs 60% of advanced stages (II–IV) (p=0,009). Differences were also relevant when patients were split by treatment: in fact, alemtuzumab induced apoptosis in 15% of T cells of untreated patients vs 52% of T cells of previously treated patients (p=0,005). Moreover, spontaneous apoptosis of T cells was more pronounced in treated vs. untreated patients (15% vs 2%, p=0.03) while the difference was not statistically significant in early vs advanced stage (p=0.06).Our in vitro data confirm that alemtuzumab is active against B-CLL cells in all stage of disease. However, in advanced stages and in previously treated patients, T cell compartment seems to be more fragile and susceptible to both spontaneous and alemtuzumab-induced apoptosis. This observation supports the hypothesis that using Alemtuzumab earlier in the treatment of B-CLL might result in less immunosuppression. The study is still ongoing with accrual of more patients samples.
Background: Imatinib is a potent tyrosine kinase inhibitor that is highly effective in the treatment of chronic myeloid leukemia. However, some patients are resistant to imatinib. Some of the ...mechanisms leading to imatinib resistance include amplification of the BCR-ABL gene, determining overexpression of the protein, and mutations in the BCR-ABL protein with alteration of imatinib binding sites. Imatinib uptake is an active process mediated by a group of transporters that includes the organic cation transporters (hOCT) and it has been shown that different expression of OCT1 may play a critical role on intracellular drug levels and, hence, resistance to imatinib. Hypoxia is another important factor that may contribute to drug resistance. Hypoxia-Inducible Factor (HIF-1α) and its downstream target, Vascular endothelial Growth Factor (VEGF), have been shown to be overexpressed in leukemic bone marrow specimens compared to normal bone marrow. The purpose of this study is to determine if the hypoxic conditions and OCT1 inhibition affect imatinib sensitivity.
Methods: Chronic myeloid leukemic cell line K562 and LAMA84 were cultured in 10% serum RPMI medium under hypoxic (3% O2) or normoxic (21% O2) conditions. All samples were treated with imatinib 1μM ± prazosin 13 μM (OCT1 reversible inhibitor) for 24 hs.
Results: Cells treated with imatinib and cultured under hypoxic conditions demonstrated decreased apoptosis and increased cell viability compared to normoxic conditions (K562 Annexin + cells 62% vs 94%, p= 0.003, LAMA84 Annexin + cells 61% vs 92%, p=0.0028). The addition of prazosin almost abrogated imatinib efficacy in normoxic environment but did not modify the effect of imatinib under hypoxic conditions.
Conclusions: Our data confirm that OCT1 is the most important imatinib carrier. Exposure of CML cell lines to an hypoxic environment results in reduced sensitivity to imatinib and this effect wasn't affected by OCT1 inhibition. Search for underlying mechanisms of these findings are in progress.
Background: The serine/threonine kinase AKT, a major downstream PI3K target, promotes continued cell growth and metabolism by increasing glucose uptake, stimulating glycolysis and ATP production. It ...has been proposed that cancer cells with a high level of constitutively active AKT depend on glucose for survival. Recent data in transgenic models demonstrated that AKT activation results in mTOR dependent transcriptional upregulation of the glycolytic enzyne HK2 and glucose transporter Glut1 via induction of HIF1-α (Nature Med 2004; 10:594). The purpose of this study was to determine the frequency and prognostic significance of increased expression of HK2 in patients with ALL, to determine if proglycolytic conditions, high glucose (HG) or hypoxia, promote chemoresistance in ALL blast cells, and if chemoresistance is affected by mTOR inhibition.
Methods: HK2 mRNA expression was measured by quantitative Taqman PCR in 28 primary ALL samples (14 newly diagnosed and 14 relapsed). Primary bone marrow samples (N=5) were co-cultured on either MS-5 or HS-5 stroma supplemented with 4 or 14 mM glucose for 24–48 hours. Jurkat cells were cultured in serum-free medium supplemented with 4 or 14 mM glucose under hypoxic (3% O2) or normoxic (21% O2) conditions. All samples were treated with doxorubicin (DOX - 25–50 ng/mL) +/− RAD001 (10–20 nM) or CCI779 (2.5–5 mg/mL).
Results: Increased expression of HK2 (≥ 2-fold relative to normal samples) occurred in 5/28 samples (18%). Patients with HK2 levels above the median (0.43) had a worse failure free survival (FFS) (HR 2.95; CI 0.89–9.81; P=0.08) and a significantly worse overall survival (OS) (HR 5.01; CI 1.21–20.7; P=0.03). In 4/5 (80%) of primary ALL samples, exposure to HG (14 mM) resulted in decreased apoptosis with DOX compared to normal glucose (4 mM) (mean % Ann+ 32.0 vs 42.0; P=0.047). This effect was reversed with addition of RAD001 or CCI779 (mean % Ann+ 49.36 vs 54.02; P=0.11). Jurkat cells cultured under hypoxic conditions and treated with DOX demonstrated decreased apoptosis and increased cell viability compared to normoxic conditions mean % Ann (+) cells 39.85 (Hypoxic) vs 55.00 (Normoxic); P=0.016). This effect was reversed with addition of RAD001 under hypoxic conditions mean % Ann (+) cells 39.85 (DOX) vs 51.92 (DOX+RAD); P=0.009 in association with decreased expression of HK2 mRNA (RE to DMSO mean 62 vs 47; P=0.26).
Conclusions: Overexpression of HK2 is associated with worse OS in pts with newly diagnosed or relapsed ALL. Exposure of ALL blast cells to high glucose or hypoxic environment results in chemoresistance to DOX. This effect is abrogated by mTOR inhibition in association with decreased expression of HK2 mRNA, suggesting that upregulation of glycolysis via the AKT/mTOR/HIF1a pathway may be an important mechanism of chemoresistance in ALL and that mTOR inhibition or glucose normalization may play an important role in chemosensitization and improved outcomes in ALL.
Background: Hyperglycemia represents a common side effect of steroid therapy and is not uncommon during treatment of patients with acute lymphocytic leukemia (ALL). Our recent retrospective study in ...278 adult patients with ALL demonstrated that hyperglycemia during induction chemotherapy occurred in up to 37% of patients and was associated with a shorter median complete remission duration and a shorter median survival (Cancer 2004 Mar 15;100(6):1179–85). The serine/threonine AKT, a major downstream PI3K target, promotes continued cell growth and metabolism by increasing glucose uptake, stimulating glycolysis and ATP production. Recent data in transgenic models demonstrated that AKT activation resulted in transcriptional upregulation of enzymes essential for glycolysis including hexokinase (HK) and Glut-1 (Nature Med., 2004, 10:594). The purpose of this study was to determine whether high AKT activity in leukemic blasts in the setting of hyperglycemia promotes survival and chemoresistance of leukemic cells by stimulation of glycolysis.
Methods and Results: A 24-hour culture of REH cells in serum-free medium supplemented with 14mM glucose resulted in induction of AKT phosphorylation (by Western blot analysis) and increase in mRNA levels of Glut-1 and HK-2 (by quantitative TaqMan PCR). PI3K inhibitor LY294002 (15 μM) prevented AKT phosphorylation and decreased mRNA expression of Glut-1 and HK-2 in high-glucose conditions and enhanced doxorubicin- and dexamethasone-induced killing. We next investigated expression of AKT 1, Glut1, and HK2 mRNA in bone marrow samples from 14 adult patients with ALL (9 pre-B-, 2 B-, 3 pre-T-ALL). The results demonstrated elevated (> 2-fold compared with normal bone marrow or peripheral blood) levels of AKT in 7/14 patients, 6 of those showed increased levels of Glut1 and 5 of HK2. In addition, in samples from 2 patients with low baseline AKT expression high HK-2 mRNA levels were observed.
Conclusions: High expression of AKT, glucose transporter Glut-1 and the glycolytic enzyme HK-2 is prevalent in primary ALL blast cells. Our results suggest that high glucose further stimulates AKT signaling in ALL blast cells resulting in upregulation of glucose transporter Glut-1 and of the glycolytic enzyme HK-2. This effect was abrogated by inhibition of PI3K/AKT signaling, resulting in chemosensitization. These data provide rationale for use of PI3K/AKT inhibitors in the therapy of ALL. The hypothesis that tight blood glucose control improves outcome in ALL patients is currently being tested in a Phase III clinical trial at M.D. Anderson Cancer Center.
The Controlling Nutritional Status (CONUT) score has demonstrated its ability to identify patients with poor nutritional status and predict various clinical outcomes. Our objective was to assess the ...association between the CONUT score, inflammatory status, and body composition, as well as its ability to identify patients at risk of frailty in hospitalized elderly patients.
a total of 361 patients were retrospectively recruited and divided into three groups based on the CONUT score.
patients with a score ≥5 exhibited significantly higher levels of inflammatory markers, such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Neutrophil/Lymphocytes ratio (NLR), main platelet volume (MPV), and ferritin, compared to those with a lower score. Furthermore, these patients showed unfavorable changes in body composition, including a lower percentage of skeletal muscle mass (MM) and fat-free mass (FFM) and a higher percentage of fatty mass (FM). A positive correlation was found between the CONUT score and inflammatory markers, Geriatric Depression Scale Short Form (GDS-SF), and FM. Conversely, the Mini Nutritional Assessment (MNA), Mini-Mental Status Examination, activity daily living (ADL), instrumental activity daily living (IADL), Barthel index, FFM, and MM showed a negative correlation. Frailty was highly prevalent among patients with a higher CONUT score. The receiver operating characteristic (ROC) curve demonstrated high accuracy in identifying frail patients (sensitivity).
a high CONUT score is associated with a pro-inflammatory status as well as with unfavorable body composition. Additionally, it is a good tool to identify frailty among hospitalized elderly patients.
