Despite the release of anatomic site-specific staging systems for soft tissue sarcomas in the eighth edition of the American Joint Committee on Cancer (AJCC) Cancer Staging Manual, the algorithms for ...sarcomas arising in the extremities/trunk and retroperitoneum differ only in the staging of lymph node metastasis. The retroperitoneum not only provides a larger potential space for tumor growth before the clinical presentation, but its anatomic complexities complicate surgical resection and adversely affect disease-free survival. Here, we propose a new staging system for MDM2-amplified liposarcomas (well-differentiated and dedifferentiated subtypes) that properly emphasizes retroperitoneal localization, degree of differentiation (histologic subtype), and presence of distant metastasis. A retrospective cohort of 4146 adult patients with surgically resected liposarcoma was extracted from the SEER database to compare the natural history of MDM2-amplified liposarcomas arising in the extremities/trunk or retroperitoneum. Separate training and validation datasets were created, and Cox proportional hazard regression, multivariable nonlinear regression, and nomographic analyses determined the most significant parameters in predicting sarcoma-specific death. A new staging system was derived and its predictive accuracy was compared with the AJCC, eighth edition system using areas under receiver operating characteristic curves and multiple concordance indices. Multivariable analysis showed that dedifferentiation (hazard ratio HR=3.7±0.5; P<0.0005), retroperitoneal location (HR=3.2±0.5; P<0.0005), and distant metastasis (HR=2.4±0.6; P=0.002), but not categorized tumor size (pT category), had the largest effects on sarcoma-specific survival. A new staging system based on these predictive factors demonstrated better discrimination between tumor stages, higher concordance with clinical outcomes, and greater predictive accuracy than the AJCC eighth edition staging system (86±1% vs. 83±2%; P=0.005). Statistical analysis of a large national cohort failed to confirm that categorized tumor size is a useful criterion by which to stage MDM2-amplified liposarcoma. A simplified staging system based on anatomic location and dedifferentiation outperforms the current AJCC staging system. Anatomic localization and histologic grade, and not tumor size, should be included in any future liposarcoma-specific staging system.
There is increasing evidence that adipocytes play an active role in the cancer microenvironment. We have previously reported that adipocytes interact with acute lymphoblastic leukemia (ALL) cells, ...contributing to chemotherapy resistance and treatment failure. In the present study, we investigated whether part of this resistance is due to adipocyte provision of lipids to ALL cells.
We cultured 3T3-L1 adipocytes, and tested whether ALL cells or ALL-released cytokines induced FFA release. We investigated whether ALL cells took up these FFA, and using fluorescent tagged BODIPY-FFA and lipidomics, evaluated which lipid moieties were being transferred from adipocytes to ALL. We evaluated the effects of adipocyte-derived lipids on ALL cell metabolism using a Seahorse XF analyzer and expression of enzymes important for lipid metabolism, and tested whether these lipids could protect ALL cells from chemotherapy. Finally, we evaluated a panel of lipid synthesis and metabolism inhibitors to determine which were affected by the presence of adipocytes.
Adipocytes release free fatty acids (FFA) when in the presence of ALL cells. These FFA are taken up by the ALL cells and incorporated into triglycerides and phospholipids. Some of these lipids are stored in lipid droplets, which can be utilized in states of fuel deprivation. Adipocytes preferentially release monounsaturated FFA, and this can be attenuated by inhibiting the desaturating enzyme steroyl-CoA decarboxylase-1 (SCD1). Adipocyte-derived FFA can relieve ALL cell endogenous lipogenesis and reverse the cytotoxicity of pharmacological acetyl-CoA carboxylase (ACC) inhibition. Further, adipocytes alter ALL cell metabolism, shifting them from glucose to FFA oxidation. Interestingly, the unsaturated fatty acid, oleic acid, protects ALL cells from modest concentrations of chemotherapy, such as those that might be present in the ALL microenvironment. In addition, targeting lipid synthesis and metabolism can potentially reverse adipocyte protection of ALL cells.
These findings uncover a previously unidentified interaction between ALL cells and adipocytes, leading to transfer of FFA for use as a metabolic fuel and macromolecule building block. This interaction may contribute to ALL resistance to chemotherapy, and could potentially be targeted to improve ALL treatment outcome.
Fasting mimicking diets (FMDs) are effective in the treatment of many solid tumors in mouse models, but their effect on hematologic malignancies is poorly understood, particularly in combination with ...standard therapies. Here we show that cycles of a 3-day FMD given to high-fat-diet-fed mice once a week increased the efficacy of vincristine to improve survival from BCR-ABL B acute lymphoblastic leukemia (ALL). In mice fed a standard diet, FMD cycles in combination with vincristine promoted cancer-free survival. RNA seq and protein assays revealed a vincristine-dependent decrease in the expression of multiple autophagy markers, which was exacerbated by the fasting/FMD conditions. The autophagy inhibitor chloroquine could substitute for fasting/FMD to promote cancer-free survival in combination with vincristine. In vitro, targeted inhibition of autophagy genes
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strongly potentiated vincristine's toxicity. Moreover, anti-CD8 antibodies reversed the effects of vincristine plus fasting/FMD in promoting leukemia-free survival in mice, indicating a central role of the immune system in this response. Thus, the inhibition of autophagy and enhancement of immune responses appear to be mediators of the fasting/FMD-dependent cancer-free survival in ALL mice.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
It is becoming increasingly recognized that weight and nutritional status can impact cancer survival. We have previously shown that obese mice with syngeneic acute lymphoblastic leukemia (ALL) have ...poorer response to chemotherapy treatment than control mice. We therefore investigated whether dietary intervention could improve outcome from the most common pediatric cancer, ALL.
Diet-induced obese (DIO) mice raised on a 60% calories from fat diet and control mice were implanted with syngeneic ALL cells. Some DIO mice were switched to the low-fat control diet. Survival from ALL was assessed without or with chemotherapy treatment starting at the time of the diet switch. Cells from DIO mice before and after diet switch were assessed by FACS for BrdU incorporation and phosphorylation status of AKT, S6K, and EIF2a. Similar experiments were done with human ALL xenografts. Mouse and human ALL cells were cultured in media with 10% or 5% fetal bovine serum, and sensitivity to chemotherapies assessed.
DIO mice had poorer survival (17%) after vincristine monotherapy than control mice on a 10% low fat diet (42%;
= 12/group;
= 0.09, log rank). However, switching obese mice to the low-fat diet prior to initiation of vincristine led to dramatically improved survival (92%,
< 0.01 vs both other groups). In vitro, FBS restriction made murine and human ALL cells more sensitive to vincristine. Interestingly, while serum restriction enhanced ALL sensitivity to dexamethasone and l-asparaginase, dietary switch did not improve survival of DIO mice treated with either drug in monotherapy. Thus, it appears that dietary intervention has a unique effect to improve ALL cell sensitivity to vincristine in vivo.
We report herein that a dietary intervention can improve ALL outcome in a preclinical model. Further work is needed to identify the mechanisms of this effect and investigate potential impact on human leukemia in patients.
Chronic osteomyelitis can be difficult to diagnose given its similar radiographic appearance to other lesions. This case report describes a 48-year-old woman, who presented with left thigh pain and ...on radiography a large disorganized sclerotic lesion involving nearly the entire femoral diaphysis, concerning for Paget disease or malignancy. Biopsy suggested chronic osteomyelitis but did not identify a causative organism. Treatment with antibiotics led to resolution of pain and improvement of biochemical markers. This case exemplifies the role of radiographic imaging in the diagnosis of chronic osteomyelitis and the possible utility of antibiotics for culture-negative chronic osteomyelitis. We review imaging modalities for the diagnosis of chronic osteomyelitis and Paget disease.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Obesity is associated with poorer outcome for many cancers. Previously, we observed that adipocytes protect acute lymphoblastic leukemia (ALL) cells from the anthracycline, daunorubicin. In this ...study, it is determined whether adipocytes clear daunorubicin from the tumor microenvironment (TME). Intracellular daunorubicin concentrations were evaluated using fluorescence. Daunorubicin and its largely inactive metabolite, daunorubicinol, were analytically measured in media, cells, and tissues using liquid chromatography/mass spectrometry (LC/MS). Expression of daunorubicin-metabolizing enzymes, aldo-keto reductases (AKR1A1, AKR1B1, AKR1C1, AKR1C2, AKR1C3, and AKR7A2) and carbonyl reductases (CBR1, CBR3), in human adipose tissue, were queried using public databases and directly measured by quantitative PCR (qPCR) and immunoblot. Adipose tissue AKR activity was measured by colorimetric assay. Adipocytes absorbed and efficiently metabolized daunorubicin to daunorubicinol, reducing its antileukemia effect in the local microenvironment. Murine studies confirmed adipose tissue conversion of daunorubicin to daunorubicinol
Adipocytes expressed high levels of AKR and CBR isoenzymes that deactivate anthracyclines. Indeed, adipocyte protein levels of AKR1C1, AKR1C2, and AKR1C3 are higher than all other human noncancerous cell types. To our knowledge, this is the first demonstration that adipocytes metabolize and inactivate a therapeutic drug. Adipocyte-mediated daunorubicin metabolism reduces active drug concentration in the TME. These results could be clinically important for adipocyte-rich cancer microenvironments such as omentum, breast, and marrow. As AKR and CBR enzymes metabolize several drugs, and can be expressed at higher levels in obese individuals, this proof-of-principle finding has important implications across many diseases.
Adipocyte absorption and metabolism of chemotherapies can reduce cytotoxicity in cancer microenvironments, potentially contributing to poorer survival outcomes.
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Abstract
The regulation of oxidative stress is fundamental to cell survival and function. Oxidative stress is a result of accumulation of reactive oxygen species (ROS), which are produced by cell ...metabolism and in response to certain stressors. Cancer cells have higher than normal ROS levels and elevated antioxidant defense mechanisms. Daunorubicin (DNR), a widely used chemotherapy, is a topoisomerase II inhibitor that induces cell death through DNA double strand breaks and increased ROS. We have previously shown that adipocytes protect acute lymphoblastic leukemia (ALL) cells against DNR in vitro and that media cultured by both adipocytes and ALL cells together (ALCM) can protect ALL cells from DNR. We hypothesize that this protection is in part mediated by adipocytes alleviating oxidative stress in ALL cells.
Murine pre-B ALL cells isolated from a BCR/ABL transgenic mouse (8093) and human leukemia cell lines (BV173, Nalm6, REH, SEM, RS4;11, HL60, and Molt4) were used. The ALL cells were co-cultured with 3T3-L1 adipocytes using a transwell system. Cells were collected for gene expression analysis using qPCR. Intracellular ROS was measured by flow cytometry with 2′-7′-dichlorodihydrofluorescein (DCFH-DA). Four of the six human leukemia cell lines tested were protected by adipocytes against DNR treatment. Western blots showed that DNR induced a significant increase in the cleaved to procaspase-3 ratio, which was reversed by ALCM (No drug: 0.24±0.2, DNR: 0.83±0.14, ALCM+DNR: 0.24±0.19; p = 0.004 for DNR vs. ALCM+DNR, n = 4). Expression of the oxidative stress response genes gclc, gclm and p21 was upregulated in 8093 cells upon DNR treatment (fold change over baseline: 1.82±0.37, 2.35±0.73, 5.55±1.50; p<0.05, n = 3), while the presence of adipocytes prevented this upregulation (fold change over baseline: 0.83±0.11, 0.88±0.02, 1.75±0.57; p<0.05, n = 3). To investigate the oxidative stress induced by DNR, Nalm6 cells were treated with five doses of DNR for 6 hours alone or in the presence of pre-adipocytes or adipocytes. There was a dose-dependent increase in%ROShigh cells regardless of feeder type. At 200nM DNR, there were significantly fewer%ROShigh cells when co-cultured with adipocytes compared to no feeder or pre-adipocytes (p<0.05, n = 3). To test whether alleviating oxidative stress alone would cause DNR resistance, BV173, Nalm6 and REH cells were treated with DNR (100, 200 and 300nM, respectively) or a combination of DNR and the anti-oxidant, N-acetyl cysteine (NAC; 20mM). The addition of NAC significantly protected the cells from DNR (p<0.05, n = 3).
These findings demonstrate that adipocytes contribute to drug resistance by alleviating oxidative stress in ALL cells. Further research is required to identify the soluble factors responsible for these protective effects.
Citation Format: Xia Sheng, Jonathan Tucci, Steven D. Mittelman. Reduction of oxidative stress promotes daunorubicin resistance in acute lymphoblastic leukemia cells. abstract. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1247. doi:10.1158/1538-7445.AM2015-1247
Abstract
One of the new therapeutic strategy to promote cancer free survival is to combine dietary intervention like fasting or fasting mimicking diets (FMDs) with cancer treatments. FMDs enhance the ...efficacy of a wide variety of therapies ranging from chemotherapy to kinase inhibitors to immunotherapy, weakening cancer cells while protecting normal cells and tissues.
In this work we show that FMD in combination with vincristine (VC), enhance the death of acute lymphoblastic leukemia (ALL) by inhibition of autophagy and induction of apoptosis by p53 modulation and activation of caspase-3. Our data indicates that a periodic FMD increases the efficacy of VC and extends the cancer free survival of an in-vivo mouse syngeneic pre-B ALL model. We identify in human and mice leukemic cells that the autophagy inhibition is the mechanism used by FMD to potentiate the cytotoxic effect of VC. Finally, in vivo treatment of FMD+VC with an autophagy inhibitor shows a synergistic effect on increasing survival in ALL mice.
Furthermore, FMD induces activation of anticancer immunity. The gene expression profile consistent with anti-cancer immune responses resulting from VC plus FMD together with accelerated cancer progression when these treatments were combined with anti-CD8 antibodies indicate a central role of the immune system in these effects. Thus, the inhibition of autophagy and enhancement of immune responses are responsible for the ability of FMD to promote cancer free survival in ALL mice.
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