Lipid phosphate phosphatase-2 promotes tumor growth through increased c-Myc expression.

LPP2 is one of three enzymes in the lipid phosphate phosphatase family (LPP1-3) that dephosphorylate extracellular and intracellular bioactive lipid phosphates and pyrophosphates. LPP2 increases cell growth and LPP2 expression is elevated in a variety of malignancies, implying that LPP2 is a pro-tumorigenic factor. Methods: LPP2 expression in human breast tumors and normal breast tissue was measured by qPCR. To understand the role of LPP2, we knocked out its expression in multiple cell lines using CRISPR/Cas9. Cell proliferation and migration were compared between wild type and LPP2 knockout cells. Cell cycle was measured by flow cytometry, and cell cycle proteins were determined by western blotting. Effects of LPP2 on tumor growth were investigated using syngeneic and xenograft mouse breast cancer models. Results: LPP2 mRNA levels were higher in ER/PR positive, ER/HER2 positive, and triple negative human breast tumors, relative to normal breast tissue. Higher levels of LPP2 in breast tumors, hepatocellular carcinoma, pancreatic adenocarcinoma, and melanomas were prognostic of poorer survival. LPP2 mRNA expression is also increased in Hs-578T, MDA-MB-231, MCF7 and MDA-MB-468 breast cancer cell lines, relative to non-malignant Hs-578Bst, MCF10A and MCF-12A cells. LPP2 knockout in breast cancer cells decreased cell growth by inhibiting G1/S transition, whereas, increasing LPP2 levels in Hs-578Bst and MCF10A cells promoted proliferation. The effects of LPP2 on cell cycle were associated with changes in cyclin A2, cyclin B1, and cell cycle inhibitors, p27 or p21. The level of c-Myc was downregulated by knocking out LPP2, and it was partly restored by re-expressing LPP2. The positive correlation between the expression of LPP2 and c-Myc exists in multiple cancer cell lines including breast, lung, upper aerodigestive tract and urinary tract cancer. LPP2 knockout in MDA-MB-231 or 4T1 cells suppressed tumor formation in mouse breast cancer models, and decreased the in vivo expression of Ki67 and c-Myc of the cancer cells. Conclusion: Targeting LPP2 could provide a new strategy for decreasing c-Myc expression and tumor growth.

Human Cytomegalovirus Seropositivity and Viral DNA in Breast Tumors Are Associated with Poor Patient Prognosis.

Human cytomegalovirus (HCMV) infects 40-70% of adults in developed countries. Detection of HCMV DNA and/or proteins in breast tumors varies considerably, ranging from 0-100%. In this study, nested PCR to detect HCMV glycoprotein B (gB) DNA in breast tumors was shown to be sensitive and specific in contrast to the detection of DNA for immediate early genes. HCMV gB DNA was detected in 18.4% of 136 breast tumors while 62.8% of 94 breast cancer patients were seropositive for HCMV. mRNA for the HCMV immediate early gene was not detected in any sample, suggesting viral latency in breast tumors. HCMV seropositivity was positively correlated with age, body mass index and menopause. Patients who were HCMV seropositive or had HCMV DNA in their tumors were 5.61 (CI 1.77-15.67, p = 0.003) or 5.27 (CI 1.09-28.75, p = 0.039) times more likely to develop Stage IV metastatic tumors, respectively. Patients with HCMV DNA in tumors experienced reduced relapse-free survival (p = 0.042). Being both seropositive with HCMV DNA-positive tumors was associated with vascular involvement and metastasis. We conclude that determining the seropositivity for HCMV and detection of HCMV gB DNA in the breast tumors could identify breast cancer patients more likely to develop metastatic cancer and warrant special treatment.

Depletion of essential fatty acids in muscle is associated with shorter survival of cancer patients undergoing surgery-preliminary report.

Emerging studies are reporting associations between skeletal muscle abnormalities and survival in cancer patients. Cancer prognosis is associated with depletion of essential fatty acids in erythrocytes and plasma in humans. However the relationship between skeletal muscle membrane fatty acid composition and survival is unknown. This study investigates the relationship between fatty acid content of phospholipids in skeletal muscle and survival in cancer patients. Rectus abdominis biopsies were collected during cancer surgery from 35 patients diagnosed with cancer. Thin-layer and gas chromatography were used for quantification of phospholipid fatty acids. Cutpoints for survival were defined using optimal stratification. Median survival was between 450 and 500 days when patients had arachidonic acid (AA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in muscle phospholipid below the cut-point compared to 720-800 days for patients above. Cox regression analysis revealed that low amounts of AA, EPA and DHA are risk factors for death. The risk of death remained significant for AA [HR 3.5 (1.11-10.87), p = 0.03], EPA [HR 3.92 (1.1-14.0), p = 0.04] and DHA [HR 4.08 (1.1-14.6), p = 0.03] when adjusted for sex. Lower amounts of essential fatty acids in skeletal muscle membrane is a predictor of survival in cancer patients. These results warrant investigation to restore bioactive fatty acids in people with cancer.

PDGFRα Enhanced Infection of Breast Cancer Cells with Human Cytomegalovirus but Infection of Fibroblasts Increased Prometastatic Inflammation Involving Lysophosphatidate Signaling.

Human cytomegalovirus (HCMV) infects 40-70% of adults in developed countries. HCMV proteins and DNA are detected in tumors and metastases, suggesting an association with increased invasion. We investigated HCMV infection in human breast cancer cell lines compared to fibroblasts, a component of tumors, and the role of platelet-derived growth factor receptor-α (PDGFRα). HCMV productively infected HEL299 fibroblasts and, to a lesser extent, Hs578T breast cancer cells. Infection of another triple-negative cell line, MDA-MB-231, and also MCF-7 cells, was extremely low. These disparate infection rates correlated with expression of PDGFRA, which facilitates HCMV uptake. Increasing PDGFRA expression in T-47D breast cancer and BCPAP thyroid cancer cells markedly increased HCMV infection. Conversely, HCMV infection decreased PDGFRA expression, potentially attenuating signaling through this receptor. HCMV infection of fibroblasts promoted the secretion of proinflammatory factors, whereas an overall decreased secretion of inflammatory factors was observed in infected Hs578T cells. We conclude that HCMV infection in tumors will preferentially target tumor-associated fibroblasts and breast cancer cells expressing PDGFRα. HCMV infection in the tumor microenvironment, rather than cancer cells, will increase the inflammatory milieu that could enhance metastasis involving lysophosphatidate.

Positron Emission Tomography Imaging of Autotaxin in Thyroid and Breast Cancer Models Using [18F]PRIMATX.

Autotaxin (ATX) is a secreted enzyme responsible for producing lysophosphatidic acid (LPA). The ATX/LPA signaling axis is typically activated in wound healing and tissue repair processes. The ATX/LPA axis is highjacked and upregulated in the progression and persistence of several chronic inflammatory diseases, including cancer. As ATX inhibitors are now progressing to clinical testing, innovative diagnostic tools such as positron emission tomography (PET) are needed to measure ATX expression in vivo accurately. The radiotracer, [18F]PRIMATX, was recently developed and tested for PET imaging of ATX in vivo in a murine melanoma model. The goal of the present work was to further validate [18F]PRIMATX as a PET imaging agent by analyzing its in vivo metabolic stability and suitability for PET imaging of ATX in models of human 8305C thyroid tumor and murine 4T1 breast cancer. [18F]PRIMATX displayed favorable metabolic stability in vivo (65% of intact radiotracer after 60 min p.i.) and provided sufficient tumor uptake profiles in both tumor models. Radiotracer uptake could be blocked by 8-12% in 8305C thyroid tumors in the presence of ATX inhibitor AE-32-NZ70 as determined by PET and ex vivo biodistribution analyses. [18F]PRIMATX also showed high brain uptake, which was reduced by 50% through the administration of ATX inhibitor AE-32-NZ70. [18F]PRIMATX is a suitable radiotracer for PET imaging of ATX in the brain and peripheral tumor tissues.

FOXQ1 is Differentially Expressed Across Breast Cancer Subtypes with Low Expression Associated with Poor Overall Survival.

PURPOSE: Forkhead box Q1 (FOXQ1) has been shown to contribute to the development and progression of cancers, including ovarian and breast cancer (BC). However, research exploring FOXQ1 expression, copy number variation (CNV), and prognostic value across different BC subtypes is limited. Our purpose was to evaluate FOXQ1 mRNA expression, CNV, and prognostic value across BC subtypes. MATERIALS AND METHODS: We determined FOXQ1 expression and CNV in BC patient tumors using RT-qPCR and qPCR, respectively. We also analyzed FOXQ1 expression and CNV in BC cell lines in the CCLE database using K-means clustering. The prognostic value of FOXQ1 expression in the TCGA-BRCA database was assessed using univariate and multivariate Cox's regression analysis as well as using the online tools OncoLnc, GEPIA, and UALCAN. RESULTS: Our analyses reveal that FOXQ1 mRNA is differentially expressed between different subtypes of BC and is significantly decreased in luminal BC and HER2 patients when compared to normal breast tissue samples. Furthermore, analysis of BC cell lines showed that FOXQ1 mRNA expression was independent of CNV. Moreover, patients with low FOXQ1 mRNA expression had significantly poorer overall survival compared to those with high FOXQ1 mRNA expression. Finally, low FOXQ1 expression had a critical impact on the prognostic values of BC patients and was an independent predictor of overall survival when it was adjusted for BC subtypes and to two other FOX genes, FOXF2 and FOXM1. CONCLUSION: Our study reveals for the first time that FOXQ1 is differentially expressed across BC subtypes and that low expression of FOXQ1 is indicative of poor prognosis in patients with BC.

Gene expression profile of epithelial-mesenchymal transition mediators in papillary thyroid cancer.

PURPOSE: Platelet derived growth receptor alpha (PDGFRA) promotes the epithelial-mesenchymal transition (EMT) in thyroid follicular cells and is linked to lymphatic metastases in papillary thyroid cancer (PTC). We probed the regulatory network of genes linked to PDGFRA and EMT, comparing matched patient primary tumor and metastatic specimens, as well as engineered cell lines and ex vivo primary cultures with and without PDGFRA. METHODS: Freshly isolated thyroid tumors with or without metastases, with matching neighboring benign or normal tissue, was isolated for comparative transcriptional analysis using a TaqMan Low Density array (TLDA) assay with genes representing important markers of EMT, cellular adhesion, apoptosis, differentiation, senescence, and signal transduction pathways in thyroid cancer. Transfected primary cultures and immortalized cell lines were also analyzed with respect to PDGFRA expression and cell phenotype. RESULTS: We reveal the consistent upregulation of serine protease DPP4 and structural protein SPP1 with the progression of PTC to metastatic disease, as well as with PDGFRA expression. Conversely, epithelial integrity gene TFF3 and transcription factor SOX10 were strongly down-regulated. This gene network also includes important mediators of EMT including DSG1, MMP3, MMP9, and BECN. We observed similar genomic changes in ex vivo normal thyroid cells transfected with PDGFRA that also exhibited a partially dedifferentiated phenotype. In particular, we observed lamellopodia with induction of PDGFRA and illustrate that DPP4 and SPP1 were upregulated in this process, with decreased TFF3 and SOX10 as seen in tissue specimens. PDGFRA did decrease nuclear protein levels of differentiation factor TTF1, but not the transcription of TTF1 and PAX8. CONCLUSIONS: We demonstrate that PDGFRA activates EMT pathways and decreases expression of genes favoring epithelial integrity, pushing follicular cells toward a dedifferentiated phenotype. SPP1 and DPP4, previously linked with adverse outcomes in thyroid cancer, appear to be regulated by PDGFRA. PDGFRA expression promotes metastatic disease through multiple EMT levers that favor formation of an invasive phenotype and increased metalloproteinase expression.

BIK drives an aggressive breast cancer phenotype through sublethal apoptosis and predicts poor prognosis of ER-positive breast cancer.

Apoptosis is fundamental to normal animal development and is the target for many anticancer therapies. Recent studies have explored the consequences of "failed apoptosis" where the apoptotic program is initiated but does not go to completion and does not cause cell death. Nevertheless, this failed apoptosis induces DNA double-strand breaks generating mutations that facilitate tumorigenesis. Whether failed apoptosis is relevant to clinical disease is unknown. BCL-2 interacting killer (BIK) is a stress-induced BH3-only protein that stimulates apoptosis in response to hormone and growth factor deprivation, hypoxia, and genomic stress. It was unclear whether BIK promotes or suppresses tumor survival within the context of breast cancer. We investigated this and show that BIK induces failed apoptosis with limited caspase activation and genomic damage in the absence of extensive cell death. Surviving cells acquire aggressive phenotypes characterized by enrichment of cancer stem-like cells, increased motility and increased clonogenic survival. Furthermore, by examining six independent cohorts of patients (total n = 969), we discovered that high BIK mRNA and protein levels predicted clinical relapse of Estrogen receptor (ER)-positive cancers, which account for almost 70% of all breast cancers diagnosed but had no predictive value for hormone receptor-negative (triple-negative) patients. Thus, this study identifies BIK as a biomarker for tumor recurrence of ER-positive patients and provides a potential mechanism whereby failed apoptosis contributes to cancer aggression.

Tyrosine kinase inhibitor therapy and metabolic remodelling in papillary thyroid cancer.

Targeted therapy is increasingly used to manage metastatic papillary thyroid cancer. The focus of the present study was to examine glucose metabolism and tumor responses for thyroid cancer xenografts expressing the glycolytic pathway modulators platelet-derived growth factor receptor (PDGFR) and BRAFV600E. Radiolabelled glucose derivative [18F]FDG was used to analyze the effects of PDGFR blockade with imatinib, BRAF blockade with vemurafenib, as well as combined PDGFR and BRAF blockade in vitro and in vivo with PET. Dynamic PET data was correlated with immunohistochemistry staining and kinetic analysis for facilitative glucose transporter 1 (GLUT1) and hexokinase-II (HK2). Vemurafenib decreased [18F]FDG uptake in BCPAP cells in vitro; however, it was increased by ~70% with imatinib application to BCPAP cells. This metabolic response to tyrosine kinase inhibition required BRAFV600E as it was not seen in cell lines lacking mutated BRAF (TPC1). In xenografts, imatinib therapy in BCPAP thyroid tumour-bearing mice significantly increased [18F]FDG uptake and retention (>30%) in BCPAP tumours with PDGFRß or both (α+ß) isoforms. Kinetic analysis revealed that the increased glucose uptake is a consequence of increased phosphorylation and intracellular trapping of [18F]FDG confirmed by an increase in HK2 protein expression and activity, but not GLUT1 activity. BRAF inhibition alone, or combined PDGFR and BRAF inhibition, reduced (~60%) [18F]FDG uptake in both types of BCPAP (ß or α+ß) tumours. In terms of tumour growth, combination therapy with imatinib and vemurafenib led to a near abolition of the tumors (~90% reduction), but single therapy for BCPAP with PDGFRα expression was much less effective. In summary, imatinib led to a paradoxical increase of [18F]FDG uptake in xenografts that was reversed through BRAFV600E inhibition. The present data show that metabolic reprogramming in thyroid cancer occurs as a consequence of BRAF-mediated upregulation of HK2 expression that may permit tumour growth with isolated blockade of upstream tyrosine kinase receptors.

Dexamethasone Attenuates X-Ray-Induced Activation of the Autotaxin-Lysophosphatidate-Inflammatory Cycle in Breast Tissue and Subsequent Breast Fibrosis.

We recently showed that radiation-induced DNA damage in breast adipose tissue increases autotaxin secretion, production of lysophosphatidate (LPA) and expression of LPA1/2 receptors. We also established that dexamethasone decreases autotaxin production and LPA signaling in non-irradiated adipose tissue. In the present study, we showed that dexamethasone attenuated the radiation-induced increases in autotaxin activity and the concentrations of inflammatory mediators in cultured human adipose tissue. We also exposed a breast fat pad in mice to three daily 7.5 Gy fractions of X-rays. Dexamethasone attenuated radiation-induced increases in autotaxin activity in plasma and mammary adipose tissue and LPA1 receptor levels in adipose tissue after 48 h. DEX treatment during five daily fractions of 7.5 Gy attenuated fibrosis by ~70% in the mammary fat pad and underlying lungs at 7 weeks after radiotherapy. This was accompanied by decreases in CXCL2, active TGF-ß1, CTGF and Nrf2 at 7 weeks in adipose tissue of dexamethasone-treated mice. Autotaxin was located at the sites of fibrosis in breast tissue and in the underlying lungs. Consequently, our work supports the premise that increased autotaxin production and lysophosphatidate signaling contribute to radiotherapy-induced breast fibrosis and that dexamethasone attenuated the development of fibrosis in part by blocking this process.

Lipid is heterogeneously distributed in muscle and associates with low radiodensity in cancer patients.

BACKGROUND: Low muscle radiodensity is associated with mortality in a variety of cancer types. Biochemical and morphological correlates are unknown. We aimed to evaluate triglyceride (TG) content and location as a function of computed tomography (CT)-derived measures of skeletal muscle radiodensity in cancer patients. METHODS: Rectus abdominis (RA) biopsies were collected during cancer surgery from 75 patients diagnosed with cancer. Thin-layer chromatography and gas chromatography were used for quantification of TG content of the muscle. Axial CT images of lumbar vertebra were used to measure muscle radiodensity. Oil Red O staining was used to determine the location of neutral lipids in frozen muscle sections. RESULTS: There was wide variation in RA radiodensity in repeated measures (CV% ranged from 3 to 55% based on 10 serial images) as well as within one slice (CV% ranged from 6 to 61% based on 10 subregions). RA radiodensity and total lumbar muscle radiodensity were inversely associated with TG content of RA (r = -0.396, P < 0.001, and r = -0.355, P = 0.002, respectively). Of the total percentage area of muscle staining positive for neutral lipid, 54 ± 17% was present as extramyocellular lipids (range 23.5-77.8%) and 46 ± 17% (range 22.2-76.5%) present as intramyocellular lipid droplets. CONCLUSIONS: Repeated measures revealed wide variation in radiodensity of RA muscle, both vertically and horizontally. Low muscle radiodensity reflects high level of TG in patients with cancer. Non-uniform distribution of intramyocellular and extramyocellular lipids was evident using light microscopy. These results warrant investigation of mechanisms resulting in lipid deposition in muscles of cancer patients.

Active surveillance of low-risk papillary thyroid cancer: A meta-analysis.

BACKGROUND: This study evaluates the safety and efficacy of active surveillance for low-risk papillary thyroid carcinoma. METHODS: MEDLINE, EMBASE, and PubMed were searched from inception for relevant studies of active surveillance for low-risk papillary thyroid carcinoma, defined as T1a or T1b, N0, M0 disease. Main outcomes of interest were growth of primary tumor, metastatic spread, thyroid cancer-related mortality, and disease recurrence after delayed thyroid surgery. RESULTS: Nine publications with 4,156 patients were included. Primary analysis of the 9 studies revealed pooled proportion of tumor growth during active surveillance to be 4.4% (95% confidence interval 3.2-5.8%). The pooled rate of metastatic spread to cervical nodes was 1.0% (95% confidence interval 0.7-1.4%), and pooled mortality due to thyroid cancer was 0.03% (95% confidence interval 0.0005-0.2%). Eight studies assessed incidence of delayed thyroid surgery with pooled proportion of 9.9% (95% confidence interval 6.4-14.0%). The main indication for surgery was patient preference, not disease progression, at 51.9% (95% confidence interval 44.9-58.9%). The pooled proportion of recurrence after delayed thyroid surgery was 1.1% (95% confidence interval 0.1-3.8%). CONCLUSION: Active surveillance appears to be a safe alternative to surgery for the management of low-risk papillary thyroid carcinoma, without increased risk of recurrence or death. This strategy allows for avoidance of exposure to surgical risk and need for subsequent thyroid replacement therapy.

Repeated Fractions of X-Radiation to the Breast Fat Pads of Mice Augment Activation of the Autotaxin-Lysophosphatidate-Inflammatory Cycle.

Breast cancer patients are usually treated with multiple fractions of radiotherapy (RT) to the whole breast after lumpectomy. We hypothesized that repeated fractions of RT would progressively activate the autotaxin-lysophosphatidate-inflammatory cycle. To test this, a normal breast fat pad and a fat pad containing a mouse 4T1 tumor were irradiated with X-rays using a small-animal "image-guided" RT platform. A single RT dose of 7.5 Gy and three daily doses of 7.5 Gy increased ATX activity and decreased plasma adiponectin concentrations. The concentrations of IL-6 and TNFα in plasma and of VEGF, G-CSF, CCL11 and CXCL10 in the irradiated fat pad were increased, but only after three fractions of RT. In 4T1 breast tumor-bearing mice, three fractions of 7.5 Gy augmented tumor-induced increases in plasma ATX activity and decreased adiponectin levels in the tumor-associated mammary fat pad. There were also increased expressions of multiple inflammatory mediators in the tumor-associated mammary fat pad and in tumors, which was accompanied by increased infiltration of CD45+ leukocytes into tumor-associated adipose tissue. This work provides novel evidence that increased ATX production is an early response to RT and that repeated fractions of RT activate the autotaxin-lysophosphatidate-inflammatory cycle. This wound healing response to RT-induced damage could decrease the efficacy of further fractions of RT.

Immunohistochemical phenotyping of T cells, granulocytes, and phagocytes in the muscle of cancer patients: association with radiologically defined muscle mass and gene expression.

BACKGROUND: Inflammation is a recognized contributor to muscle wasting. Research in injury and myopathy suggests that interactions between the skeletal muscle and immune cells confer a pro-inflammatory environment that influences muscle loss through several mechanisms; however, this has not been explored in the cancer setting. This study investigated the local immune environment of the muscle by identifying the phenotype of immune cell populations in the muscle and their relationship to muscle mass in cancer patients. METHODS: Intraoperative muscle biopsies were collected from cancer patients (n = 30, 91% gastrointestinal malignancies). Muscle mass was assessed histologically (muscle fiber cross-sectional area, CSA; µm2) and radiologically (lumbar skeletal muscle index, SMI; cm2/m2 by computed tomography, CT). T cells (CD4 and CD8) and granulocytes/phagocytes (CD11b, CD14, and CD15) were assessed by immunohistochemistry. Microarray analysis was conducted in the muscle of a second cancer patient cohort. RESULTS: T cells (CD3+), granulocytes/phagocytes (CD11b+), and CD3-CD4+ cells were identified. Muscle fiber CSA (µm2) was positively correlated (Spearman's r = > 0.45; p = < 0.05) with the total number of T cells, CD4, and CD8 T cells and granulocytes/phagocytes. In addition, patients with the smallest SMI exhibited fewer CD8 T cells within their muscle. Consistent with this, further exploration with gene correlation analyses suggests that the presence of CD8 T cells is negatively associated (Pearson's r = ≥ 0.5; p = <0.0001) with key genes within muscle catabolic pathways for signaling (ACVR2B), ubiquitin proteasome (FOXO4, TRIM63, FBXO32, MUL1, UBC, UBB, UBE2L3), and apoptosis/autophagy (CASP8, BECN1, ATG13, SIVA1). CONCLUSION: The skeletal muscle immune environment of cancer patients is comprised of immune cell populations from the adaptive and innate immunity. Correlations of T cells, granulocyte/phagocytes, and CD3-CD4+ cells with muscle mass measurements indicate a positive relationship between immune cell numbers and muscle mass status in cancer patients. Further exploration with gene correlation analyses suggests that the presence of CD8 T cells is negatively correlated with components of muscle catabolism.

Increasing the low lipid phosphate phosphatase 1 activity in breast cancer cells decreases transcription by AP-1 and expressions of matrix metalloproteinases and cyclin D1/D3.

Metastasis is the leading cause of mortality in breast cancer patients and lysophosphatidate (LPA) signaling promotes this process. LPA signaling is attenuated by lipid phosphate phosphatase-1 (LPP1) whose activity is decreased in cancers. Consequently, increasing LPP1 levels suppresses breast tumor growth and metastasis. This study shows that increasing LPP1 in breast cancer cells decreases transcription through cFos and cJun. This decreases production of cyclin D1/D3 and matrix metalloproteinases (MMPs), which provides new insights into the role of LPP1 in controlling tumor growth and metastasis. Methods: Invasiveness was determined by a Matrigel invasion assay. MMP expression was measured by qPCR, multiplex LASER bead technology and gelatin zymography. Levels of cJUN, cFOS, FRA1, cyclin D1, and cyclin D3 were determined by qPCR and western blotting. Collagen was determined by Picro-Sirius Red staining. Results: Increasing LPP1 expression inhibited invasion of MDA-MB-231 breast cancer cells through Matrigel. This was accompanied by decreases in expression of MMP-1, -3, -7, -9, -10, -12 and -13, which are transcriptionally regulated by the AP-1 complex. Increasing LPP1 attenuated the induction of mRNA of MMP-1, -3, cFOS, and cJUN by EGF or TNFα, but increased FRA1. LPP1 expression also decreased the induction of protein levels for cFOS and cJUN in nuclei and cytoplasmic fractions by EGF and TNFα. Protein levels of cyclin D1 and D3 were also decreased by LPP1. Although FRA1 in total cell lysates or cytoplasm was increased by LPP1, nuclear FRA1 was not affected. LPP1-induced decreases in MMPs in mouse tumors created with MDA-MB-231 cells were accompanied by increased collagen in the tumors and fewer lung metastases. Knockdown of LPP1 in MDA-MB-231 cells increased the protein levels of MMP-1 and -3. Human breast tumors also have lower levels of LPP1 and higher levels of cJUN, cFOS, MMP-1, -7, -8, -9, -12, -13, cyclin D1, and cyclin D3 relative to normal breast tissue. Conclusion: This study demonstrated that the low LPP1 expression in breast cancer cells is associated with high levels of cyclin D1/D3 and MMPs as a result of increased transcription by cFOS and cJUN. Increasing LPP1 expression provides a novel approach for decreasing transcription through AP-1, which could provide a strategy for decreasing tumor growth and metastasis.

Clinical and biological characterization of skeletal muscle tissue biopsies of surgical cancer patients.

BACKGROUND: Researchers increasingly use intraoperative muscle biopsy to investigate mechanisms of skeletal muscle atrophy in patients with cancer. Muscles have been assessed for morphological, cellular, and biochemical features. The aim of this study was to conduct a state-of-the-science review of this literature and, secondly, to evaluate clinical and biological variation in biopsies of rectus abdominis (RA) muscle from a cohort of patients with malignancies. METHODS: Literature was searched for reports on muscle biopsies from patients with a cancer diagnosis. Quality of reports and risk of bias were assessed. Data abstracted included patient characteristics and diagnoses, sample size, tissue collection and biobanking procedures, and results. A cohort of cancer patients (n = 190, 88% gastrointestinal malignancies), who underwent open abdominal surgery as part of their clinical care, consented to RA biopsy from the site of incision. Computed tomography (CT) scans were used to quantify total abdominal muscle and RA cross-sectional areas and radiodensity. Biopsies were assessed for muscle fibre area (µm2 ), fibre types, myosin heavy chain isoforms, and expression of genes selected for their involvement in catabolic pathways of muscle. RESULTS: Muscle biopsy occurred in 59 studies (total N = 1585 participants). RA was biopsied intraoperatively in 40 studies (67%), followed by quadriceps (26%; percutaneous biopsy) and other muscles (7%). Cancer site and stage, % of male participants, and age were highly variable between studies. Details regarding patient medical history and biopsy procedures were frequently absent. Lack of description of the population(s) sampled and low sample size contributed to low quality and risk of bias. Weight-losing cases were compared with weight stable cancer or healthy controls without considering a measure of muscle mass in 21 out of 44 studies. In the cohort of patients providing biopsy for this study, 78% of patients had preoperative CT scans and a high proportion (64%) met published criteria for sarcopenia. Fibre type distribution in RA was type I (46% ± 13), hybrid type I/IIA (1% ± 1), type IIA (36% ± 10), hybrid type IIA/D (15% ± 14), and type IID (2% ± 5). Sexual dimorphism was prominent in RA CT cross-sectional area, mean fibre cross-sectional area, and in expression of genes associated with muscle growth, apoptosis, and inflammation (P < 0.05). Medical history revealed multiple co-morbid conditions and medications. CONCLUSIONS: Continued collaboration between researchers and cancer surgeons enables a more complete understanding of mechanisms of cancer-associated muscle atrophy. Standardization of biobanking practices, tissue manipulation, patient characterization, and classification will enhance the consistency, reliability, and comparability of future studies.

Efficacy of 177Lu Peptide Receptor Radionuclide Therapy for the Treatment of Neuroendocrine Tumors: A Meta-analysis.

OBJECTIVE: The purpose of this study was to assess the efficacy of Lu-labeled peptide receptor radionuclide therapy (PRRT) induction treatments for patients with unresectable metastatic neuroendocrine tumors. METHODS: MEDLINE, EMBASE, and Ovid were systematically searched with keywords "lutetium," "Lu-177," "PRRT," "neuroendocrine," and "prognosis." Studies evaluating treatment with Lu-labeled PRRT were assessed for disease response and/or disease control rate by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 or 1.1, modified RECIST, Southwest Oncology Group (SWOG), or modified SWOG criteria. Pooled proportions of disease response and control rates were calculated for both fixed- and random-effects models. RESULTS: Eighteen studies with 1920 patients were included (11 with 1268 patients using RECIST and 6 with 804 patients using SWOG). By RECIST criteria, the pooled disease response rate by random-effects model was 29.1% (95% confidence interval [CI], 20.2%-38.9%), and disease control rate was 74.1% (95% CI, 67.8%-80.0%). By SWOG criteria, the pooled disease response rate by random-effects model was 30.6% (95% CI, 20.7%-41.5%), and disease control rate was 81.1% (95% CI, 76.4%-85.4%). CONCLUSIONS: Induction therapy, typically 4 treatments, with Lu PRRT is an effective method of treating unresectable metastatic neuroendocrine tumors with significant disease response and control rates.

Loss of nuclear localization of thyroid transcription factor 1 and adverse outcomes in papillary thyroid cancer.

Function of the thyroid follicular cell depends on nuclear expression of thyroid transcription factor 1 (TTF1). Regulation of this key protein regulating iodide transport is not well known, but its loss is linked to the most lethal of thyroid malignancies. We examined TTF1 nuclear expression in the context of adverse pathological features, disease recurrence, and BRAF status in papillary thyroid carcinomas with (n = 182) and without (n = 303) nodal metastases. Overall nuclear expression level of TTF1 was strong and diffuse in approximately 73%, whereas 27% exhibited lower levels or a paucity of nuclear staining. In the same cohort, approximately 59% exhibited the BRAF mutation. On univariate analysis, low levels of TTF1 nuclear expression was linked to vascular invasion, extrathyroidal extension, and nodal metastases. Multivariate analysis indicated that low levels of TTF1 were most strongly linked to nodal metastases and vascular invasion. Interestingly, TTF1 levels were not linked to the BRAF mutation. TTF1 staining alone predicted disease recurrence, but when combined with BRAF status, the 2 markers exhibited a more marked influence. Patients lacking the BRAF mutation and exhibiting normal levels of TTF1 exhibited very low levels of disease recurrence (11% at 10 years). Conversely, patient tumors with low levels of TTF1 and the BRAF mutation recurred in 31% of cases in the same time frame. The mixed expression of BRAF under varying levels of differentiation may explain, in part, the contradictory studies regarding the impact of BRAF mutations on patient prognosis and also indicates a complex genomic signature for dedifferentiated thyroid cancer.

Dexamethasone decreases the autotaxin-lysophosphatidate-inflammatory axis in adipose tissue: implications for the metabolic syndrome and breast cancer.

Lysophosphatidate (LPA) signaling through 6 receptors is regulated by the balance of LPA production by autotaxin (ATX) vs. LPA degradation by lipid phosphate phosphatases (LPPs). LPA promotes an inflammatory cycle by increasing the synthesis of cyclooxygenase-2 and multiple inflammatory cytokines that stimulate further ATX production. We aimed to determine whether the anti-inflammatory glucocorticoid (GC) dexamethasone (Dex) functions partly by decreasing the ATX-LPA inflammatory cycle in adipose tissue, a major site of ATX secretion. Treatment of human adipose tissue with 10-1000 nM Dex decreased ATX secretion, increased LPP1 expression, and decreased mRNA expressions of IL-6, TNF-α, peroxisome proliferator-activated receptor (PPAR)-γ, and adiponectin. Cotreatment with rosiglitazone (an insulin sensitizer), insulin, or both abolished Dex-induced decreases in ATX and adiponectin secretion, but did not reverse Dex-induced decreases in secretions of 20 inflammatory cytokines and chemokines. Dex-treated mice exhibited lower ATX activity in plasma, brain, and adipose tissue; decreased mRNA levels for LPA and sphingosine 1-phosphate (S1P) receptors in brain; and decreased plasma concentrations of LPA and S1P. Our results establish a novel mechanism for the anti-inflammatory effects of Dex through decreased signaling by the ATX-LPA-inflammatory axis. The GC action in adipose tissue has implications for the pathogenesis of insulin resistance and obesity in metabolic syndrome and breast cancer treatment.-Meng, G., Tang, X., Yang, Z., Zhao, Y., Curtis, J. M., McMullen, T. P. W., Brindley, D. N. Dexamethasone decreases the autotaxin-lysophosphatidate-inflammatory axis in adipose tissue: implications for the metabolic syndrome and breast cancer.

Low-Activity Radioactive Iodine Therapy for Thyroid Carcinomas Exhibiting Nodal Metastases and Extrathyroidal Extension May Lead to Early Disease Recurrence.

BACKGROUND: The application of radioactive iodine in differentiated thyroid carcinomas has become more selective in an attempt to decrease morbidity. While ablative success has been documented, it is less clear how changes in radioactive iodine treatment strategies will influence long-term recurrence rates for patients with larger tumors and adverse pathological features, including extrathyroidal extension and nodal metastases. METHODS: Patients diagnosed between 1995 and 2008 with differentiated thyroid carcinoma treated with thyroidectomy followed by radioactive iodine treatment were eligible. All patients were followed for a minimum of five years using a standardized follow-up protocol requiring both biochemical and imaging assessments for recurrent disease (n = 219). Patients were stratified by initial radioactive iodine activity, and disease-free survival was calculated using the Kaplan-Meier method, with significant differences defined by the log-rank test. RESULTS: In this cohort, 46% of patients had clinical metastases and 74% had primary tumors >1.5 cm. Patients who had recurrences were more likely to present with extrathyroidal extension (p = 0.002) and lymph node metastases at diagnosis (p < 0.001). Patients presenting with both extrathyroidal extension and lymph node metastases had a significantly worse time to progression if treated with <1850 MBq radioactive iodine compared to those patients treated with >1850 MBq (25 months vs. 121 months; p = 0.004). The use of lower-activity radioactive iodine ablative therapy was associated with more early recurrences (p = 0.003). Being aged younger or older than 45 years did not impact the time to recurrence nor did the use of level 6 dissection. On multivariate analysis, lymph node metastases at diagnosis and multiple applications of radioactive iodine were linked to increased risk of recurrence. Patients with neither, or only one, adverse pathologic feature had excellent outcomes, regardless of initial ablative activity, with <10% of patients recurring over a 10-year time span. CONCLUSIONS: Recurrent disease in differentiated thyroid carcinoma is more common in patients treated with low-activity radioactive iodine in patients with lymph node metastases and extrathyroidal extension. These recurrences typically occur within four years of initial treatment. Patients lacking both of these risk factors treated with low radioactive iodine activity (<1850 MBq) have excellent outcomes, even after 10 years.