Purpose: To determine the MTD, dose-limiting toxicities (DLT), pharmacokinetics, and biologic effects of cixutumumab administered in combination with temsirolimus to children with refractory solid tumors.
Experimental Design: Cixutumumab and temsirolimus were administered intravenously once every 7 days in 28-day cycles. Pharmacokinetic and biology studies, including assessment of mTOR downstream targets in peripheral blood mononuclear cells, were performed during the first cycle.
Results: Thirty-nine patients, median age 11.8 years (range, 1–21.5), with recurrent solid or central nervous system tumors were enrolled, of whom 33 were fully assessable for toxicity. There were four dose levels, which included two dose reductions and a subsequent intermediated dose escalation: (i) IMC-A12 6 mg/kg, temsirolimus 15 mg/m2; (ii) IMC-A12 6 mg/kg, temsirolimus 10 mg/m2; (iii) IMC-A12 4 mg/kg, temsirolimus 8 mg/m2; and (iv) IMC-A12 6 mg/kg, temsirolimus 8 mg/m2. Mucositis was the predominant DLT. Other DLTs included hypercholesterolemia, fatigue, thrombocytopenia, and increased alanine aminotransferase. Target inhibition (decreased S6K1 and PAkt) in peripheral blood mononuclear cells was noted at all dose levels. Marked interpatient variability in temsirolimus pharmacokinetic parameters was noted. At 8 mg/m2, the median temsirolimus AUC was 2,946 ng • h/mL (range, 937–5,536) with a median sirolimus AUC of 767 ng • h/mL (range, 245–3,675).
Purpose: CUDC-101 is a small molecule that simultaneously inhibits the epidermal growth factor receptor (EGFR), human growth factor receptor 2 (HER2), and histone deacetylase (HDAC) with preclinical activity in head and neck squamous cell cancer (HNSCC). The primary objective of this investigation is to determine the maximum tolerated dose (MTD) of CUDC-101 with cisplatin–radiotherapy in the treatment of HNSCC.
Experimental Design: CUDC-101 monotherapy was administered intravenously three times weekly (Monday, Wednesday, Friday) for a one-week run-in, then continued with concurrent cisplatin (100 mg/m2 every 3 weeks) and external beam radiation (70 Gy to gross disease) over 7 weeks.
Results: Twelve patients with intermediate or high-risk HNSCC enrolled. Eleven were p16INKa (p16)-negative. The MTD of CUDC-101–based combination therapy was established at 275 mg/m2/dose. Five patients discontinued CUDC-101 due to an adverse event (AE); only one was considered a dose-limiting toxicity (DLT), at the MTD. Pharmacokinetic evaluation suggested low accumulation with this dosing regimen. HDAC inhibition was demonstrated by pharmacodynamic analyses in peripheral blood mononuclear cells (PBMC), tumor biopsies, and paired skin biopsies. Paired tumor biopsies demonstrated a trend of EGFR inhibition. At 1.5 years of median follow-up, there has been one recurrence and two patient deaths (neither attributed to CUDC-101). The remaining nine patients are free of progression.
Purpose: Veliparib, a PARP inhibitor, demonstrated clinical activity in combination with oral cyclophosphamide in patients with BRCA-mutant solid tumors in a phase I trial. To define the relative contribution of PARP inhibition to the observed clinical activity, we conducted a randomized phase II trial to determine the response rate of veliparib in combination with cyclophosphamide compared with cyclophosphamide alone in patients with pretreated BRCA-mutant ovarian cancer or in patients with pretreated primary peritoneal, fallopian tube, or high-grade serous ovarian cancers (HGSOC).
Experimental Design: Adult patients were randomized to receive cyclophosphamide alone (50 mg orally once daily) or with veliparib (60 mg orally once daily) in 21-day cycles. Crossover to the combination was allowed at disease progression.
Results: Seventy-five patients were enrolled and 72 were evaluable for response; 38 received cyclophosphamide alone and 37 the combination as their initial treatment regimen. Treatment was well tolerated. One complete response was observed in each arm, with three partial responses (PR) in the combination arm and six PRs in the cyclophosphamide alone arm. Genetic sequence and expression analyses were performed for 211 genes involved in DNA repair; none of the detected genetic alterations were significantly associated with treatment benefit.
Purpose: We tested whether 18 polymorphisms in 16 genes (GSTP1, COX2, IL10, EGFR, EGF, FGFR4, CCDN1, VEGFR2, VEGF, CXCR2, IL8, MMP3, ICAM1, ERCC1, RAD51, and XRCC3) would predict disease-free survival (DFS), overall survival (OS), and toxicity in the INT0144 trial, which was designed to investigate different postoperative regimens of 5-fluorouracil (5-FU)–based chemoradiation (CRT) in locally advanced rectal cancers: Arm 1 consisted of bolus 5-FU followed by 5-FU protracted venous infusion (PVI) with radiotherapy; arm 2 was induction and concomitant PVI 5-FU with radiotherapy and arm 3 was induction and concomitant bolus 5-FU with radiotherapy.
Experimental Design: DNA from 746 stage II/III rectal patients enrolled in the Southwest Oncology Group (SWOG) S9304 phase III trial was analyzed. Genomic DNA was extracted from formalin-fixed, paraffin-embedded (FFPE) tumor tissue. The polymorphisms were analyzed using direct DNA-sequencing or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).
Results:GSTP1-Ile105Val (rs1695) was significantly associated with DFS and OS and its effect did not vary by treatment arm. The five-year DFS and OS were 53% and 58%, respectively, for G/G, 66% and 72% for G/A, and 57% and 66% for A/A patients. In arm 2, IL8-251A/A genotype (rs4073) was associated with a lower risk of toxicities (P = 0.04). The VEGFR2 H472Q Q/Q genotype (rs1870377) was associated with a higher risk of grade 3–5 proximal upper gastrointestinal tract (PUGIT) mucositis (P = 0.04) in arm 2. However, in arm 1, this genotype was associated with a lower risk of PUGIT mucositis (P = 0.004).
Purpose: Defective oxidative stress response may increase cancer susceptibility. In tumors, these rescue mechanisms may cause chemo- and radioresistance impacting patient outcome. We previously showed that genetic variation in the nuclear factor erythroid 2–related factor 2 (NFE2L2) is associated with breast cancer risk and prognosis. Here we further studied this pathway by investigating Kelch-like ECH-associated protein 1 (KEAP1).
Experimental Design: Five tagging SNPs in the KEAP1 gene were genotyped in 996 breast cancer cases and 880 controls from two Finnish case–control sets. KEAP1 protein expression was studied in 373 invasive breast cancer tumors.
Results: rs34197572 genotype TT was associated with increased risk of breast cancer in the KBCP samples [P = 1.8x10–4; OR, 7.314; confidence interval (CI), 2.185–24.478]. rs11085735 allele A was associated with lower KEAP1 protein expression (P = 0.040; OR,= 3.545) and high nuclear NRF2 expression (P = 0.009; OR, 2.445) and worse survival in all invasive cases (P = 0.023; HR, 1.634). When including treatment data, rs11085735 was associated with recurrence-free survival (RFS; P = 0.020; HR, 1.545) and breast cancer–specific survival (P = 0.016; HR, 1.683) and rs34197572 with overall survival (P = 0.045; HR, 1.304). rs11085735 associated with RFS also among tamoxifen-treated cases (P = 0.003; HR, 3.517). Among radiotherapy-treated cases, overall survival was associated with rs34197572 (P = 0.018; HR, 1.486) and rs8113472 (P = 0.025; HR, 1.455). RFS was associated with rs9676881 (P = 0.024; HR, 1.452) and rs1048290 (P = 0.020; HR, 1.468) among all invasive cases and among estrogen receptor (ER)-positive tamoxifen-treated cases (P = 0.018; HR, 2.407 and P = 0.015; HR, 2.476, respectively).
Purpose: This study was implemented to investigate the associations between SNP in mature microRNA (miRNA) sequence and lung cancer prognosis and to verify the function of those SNP.
Experimental Design: Eight SNPs (rs3746444T>C in hsa-mir-499, rs4919510C>G in hsa-mir-608, rs13299349G>A in hsa-mir-3152, rs12220909G>C in hsa-mir-4293, rs2168518G>A in hsa-mir-4513, rs8078913T>C in hsa-mir-4520a, rs11237828T>C in hsa-mir-5579, and rs9295535T>C in hsa-mir-5689) were analyzed in a southern Chinese population with 576 patients with lung cancer, and the significant results were validated in two additional cohorts of 346 and 368 patients, respectively. A series of experiments were performed to evaluate the relevancies of those potentially functional SNPs.
Results: We found that the microRNA-499 rs3746444T>C polymorphism exhibited a consistently poor prognosis for patients with lung cancer in the discovery set [HR, 1.24; 95% confidence interval (CI), 1.02–1.49; P = 0.028], in the validation set I (HR, 1.31; 95% CI, 1.01–1.71; P = 0.048) and in the validation set II (HR, 1.45; 95% CI, 1.12–1.86; P = 0.004). The adverse effect of CT/CC variants was more remarkable in patients receiving platinum-based chemotherapy. Further functional assays demonstrated that the rs3746444C variant allele influences the expression of several cancer-related genes and affects lung cancer cells' proliferation and tumor growth in vivo and in vitro via the cisplatinum resistance.
Purpose: DNA methyltransferase 3A (DNMT3A) is one of the commonly mutated genes in acute myelogenous leukemia (AML). Reports on the prognostic significance of DNMT3A mutations have been inconsistent, and most of the data are available only for patients 60 years of age or younger. We hypothesized that this inconsistency is due to an interaction between the dose of anthracycline used in induction therapy and DNMT3A status. We studied whether patients with DNMT3A-mutated AML treated with standard dose anthracyclines had an inferior survival compared with patients with other mutation profiles or those who received high-dose therapy.
Experimental Design: A total of 152 patients in this retrospective cohort study (median age, 54 years) with de novo AML underwent induction therapy and next-generation sequencing of 33 commonly mutated genes in hematologic malignancies, including DNMT3A, FLT3-ITD, NPM1, and IDH1/2. Cox regression was used to know whether those with DNMT3A mutations who were treated with standard dose anthracycline had inferior survival.
Results:DNMT3A mutations, found in 32% of patients, were not associated with an inferior survival. Dose escalation of anthracycline in the induction regimen was associated with improved survival in those with DNMT3A mutations but not those with wild-type DNMT3A. Patients with DNMT3A mutations who received standard dose induction had shorter survival time than other patient groups (10.1 months vs. 19.8 months, P = 0.0129). This relationship remained significant (HR, 1.90; P = 0.006) controlling for multiple variables.
Purpose: Gene fusions leading to androgen receptor–modulated ERG overexpression occur in up to 70% of metastatic castration-resistant prostate cancers (mCRPC). We assessed the association between ERG rearrangement status and clinical benefit from abiraterone acetate.
Experimental Design: COU-AA-302 is a phase III trial comparing abiraterone acetate and prednisone versus prednisone in chemotherapy-naïve mCRPC. ERG status was evaluated by FISH on archival tumors. End points included radiographic progression-free survival (rPFS), time to PSA progression (TTPP), rate of ≥50% PSA decline from baseline, and overall survival (OS). Cox regression was used to evaluate association with time-to-event measures and Cochran–Mantel–Haenszel for PSA response.
Results:ERG status was defined for 348 of 1,088 intention-to-treat patients. ERG was rearranged in 121 of 348 patients with confirmed ERG status (35%). Cancers with an ERG fusion secondary to deletion of 21q22 and increased copy number of fusion sequences (class 2+ Edel) had a greater improvement in rPFS after abiraterone acetate and prednisone [22 vs. 5.4 months; HR (95% confidence interval, CI), 0.31 (0.15–0.68); P = 0.0033] than cancers with no ERG fusion [16.7 vs. 8.3 months; 0.53 (0.38–0.74); P = 0.0002] or other classes of ERG rearrangement. There was also greater benefit in this subgroup for TTPP.
Purpose: In cancer cells, the epigenome is often deregulated, and inhibition of the bromodomain and extra-terminal (BET) family of bromodomain-containing proteins is a novel epigenetic therapeutic approach. Preliminary results of an ongoing phase I trial have reported promising activity and tolerability with the new BET bromodomain inhibitor OTX015.
Experimental Design: We assessed the preclinical activity of OTX015 as single agent and in combination in mature B-cell lymphoma models and performed in vitro and in vivo experiments to identify the mechanism of action and the genetic features associated with sensitivity to the compound.
Results: OTX015 showed antiproliferative activity in a large panel of cell lines derived from mature B-cell lymphoid tumors with median IC50 of 240 nmol/L, without significant differences among the different histotypes. In vitro and in vivo experiments showed that OTX015 targeted NFKB/TLR/JAK/STAT signaling pathways, MYC- and E2F1-regulated genes, cell-cycle regulation, and chromatin structure. OTX015 presented in vitro synergism with several anticancer agents, especially with mTOR and BTK inhibitors. Gene expression signatures associated with different degrees of sensitivity to OTX015 were identified. Although OTX015 was mostly cytostatic, the compound induced apoptosis in a genetically defined subgroup of cells, derived from activated B-cell–like diffuse large B-cell lymphoma, bearing wtTP53, mutations in MYD88, and CD79B or CARD11.
Purpose: To assess the immunologic effects of dabrafenib and trametinib in vitro and to test whether trametinib potentiates or antagonizes the activity of immunomodulatory antibodies in vivo.
Experimental Design: Immune effects of dabrafenib and trametinib were evaluated in human CD4+ and CD8+ T cells from healthy volunteers, a panel of human tumor cell lines, and in vivo using a CT26 mouse model.
Results: Dabrafenib enhanced pERK expression levels and did not suppress human CD4+ or CD8+ T-cell function. Trametinib reduced pERK levels, and resulted in partial/transient inhibition of T-cell proliferation/expression of a cytokine and immunomodulatory gene subset, which is context dependent. Trametinib effects were partially offset by adding dabrafenib. Dabrafenib and trametinib in BRAF V600E/K, and trametinib in BRAF wild-type tumor cells induced apoptosis markers, upregulated HLA molecule expression, and downregulated certain immunosuppressive factors such as PD-L1, IL1, IL8, NT5E, and VEGFA. PD-L1 expression in tumor cells was upregulated after acquiring resistance to BRAF inhibition in vitro. Combinations of trametinib with immunomodulators targeting PD-1, PD-L1, or CTLA-4 in a CT26 model were more efficacious than any single agent. The combination of trametinib with anti–PD-1 increased tumor-infiltrating CD8+ T cells in CT26 tumors. Concurrent or phased sequential treatment, defined as trametinib lead-in followed by trametinib plus anti–PD-1 antibody, demonstrated superior efficacy compared with anti–PD-1 antibody followed by anti–PD-1 plus trametinib.
Purpose: To investigate the roles of melanoma-associated macrophages in melanoma resistance to BRAF inhibitors (BRAFi).
Experimental Design: An in vitro macrophage and melanoma cell coculture system was used to investigate whether macrophages play a role in melanoma resistance to BRAFi. The effects of macrophages in tumor resistance were examined by proliferation assay, cell death assay, and Western blot analyses. Furthermore, two mouse preclinical models were used to validate whether targeting macrophages can increase the antitumor activity of BRAFi. Finally, the number of macrophages in melanoma tissues was examined by immunohistochemistry.
Results: We demonstrate that in BRAF-mutant melanomas, BRAFi paradoxically activate the mitogen-activated protein kinase (MAPK) pathway in macrophages to produce VEGF, which reactivates the MAPK pathway and stimulates cell growth in melanoma cells. Blocking the MAPK pathway or VEGF signaling then reverses macrophage-mediated resistance. Targeting macrophages increases the antitumor activity of BRAFi in mouse and human tumor models. The presence of macrophages in melanomas predicts early relapse after therapy.
Purpose: We decided to construct a novel oncolytic adenovirus whose replication was driven by the CDC25B promoter for its use in preclinical models of pancreatic cancer.
Experimental Design: We placed the essential E1A gene under control of the CDC25B promoter. Based on preliminary data, we pseudotyped the adenovirus with a chimeric fiber of serotypes 5/3. We investigated the in vitro lytic effect and the in vivo therapeutic efficacy in combination with gemcitabine on human pancreatic tumor xenografts orthotopically growing in nude mice and in tumors growing in Syrian hamsters. We also assessed biochemical markers of hepatic toxicity and CA19.9 levels.
Results: AV25CDC exhibited a strong in vitro lytic effect on pancreatic cancer cells. In vivo administration of AV25CDC combined with gemcitabine in mice harboring subcutaneously growing SW1990 pancreatic tumors almost abrogated tumor growth. Nude mice harboring 15-day-old orthotopic tumors, treated intratumorally or systemically with AV25CDC combined with gemcitabine, exhibited 70% to 80% reduction in tumor size compared with control mice that lasted for at least 60 days. Chemovirotherapy treatment induced a return to normal levels of biochemical parameters of hepatic toxicity; these mice exhibited more than 90% reduction in CA19.9 serum levels compared with control. Chemovirotherapy efficacy was confirmed in mice harboring Mia PaCa-2 tumors and in Syrian hamster harboring HaP-T1 tumors. We observed that viral treatment disrupted tumor architecture and induced an increase in MMP-9 activity that might facilitate gemcitabine penetrability.
Purpose: Enzalutamide (ENZ) is a potent androgen receptor (AR) antagonist with activity in castration-resistant prostate cancer (CRPC); however, progression to ENZ-resistant (ENZ-R) CRPC frequently occurs with rising serum PSA levels, implicating AR full-length (ARFL) or variants (AR-Vs) in disease progression.
Experimental Design: To define functional roles of ARFL and AR-Vs in ENZ-R CRPC, we designed 3 antisense oligonucleotides (ASO) targeting exon-1, intron-1, and exon-8 in AR pre-mRNA to knockdown ARFL alone or with AR-Vs, and examined their effects in three CRPC cell lines and patient-derived xenografts.
Results: ENZ-R-LNCaP cells express high levels of both ARFL and AR-V7 compared with CRPC-LNCaP; in particular, ARFL levels were approximately 12-fold higher than AR-V7. Both ARFL and AR-V7 are highly expressed in the nuclear fractions of ENZ-R-LNCaP cells even in the absence of exogenous androgens. In ENZ-R-LNCaP cells, knockdown of ARFL alone, or ARFL plus AR-Vs, similarly induced apoptosis, suppressed cell growth and AR-regulated gene expression, and delayed tumor growth in vivo. In 22Rv1 cells that are inherently ENZ-resistant, knockdown of both ARFL and AR-Vs more potently suppressed cell growth, AR transcriptional activity, and AR-regulated gene expression than knockdown of ARFL alone. Exon-1 AR-ASO also inhibited tumor growth of LTL-313BR patient-derived CRPC xenografts.
Purpose: Genomic profiling studies suggest that triple-negative breast cancer (TNBC) is a heterogeneous disease. In this study, we sought to define TNBC subtypes and identify subtype-specific markers and targets.
Experimental Design: RNA and DNA profiling analyses were conducted on 198 TNBC tumors [estrogen receptor (ER) negativity defined as Allred scale value ≤ 2] with >50% cellularity (discovery set: n = 84; validation set: n = 114) collected at Baylor College of Medicine (Houston, TX). An external dataset of seven publically accessible TNBC studies was used to confirm results. DNA copy number, disease-free survival (DFS), and disease-specific survival (DSS) were analyzed independently using these datasets.
Results: We identified and confirmed four distinct TNBC subtypes: (i) luminal androgen receptor (AR; LAR), (ii) mesenchymal (MES), (iii) basal-like immunosuppressed (BLIS), and (iv) basal-like immune-activated (BLIA). Of these, prognosis is worst for BLIS tumors and best for BLIA tumors for both DFS (log-rank test: P = 0.042 and 0.041, respectively) and DSS (log-rank test: P = 0.039 and 0.029, respectively). DNA copy number analysis produced two major groups (LAR and MES/BLIS/BLIA) and suggested that gene amplification drives gene expression in some cases [FGFR2 (BLIS)]. Putative subtype-specific targets were identified: (i) LAR: androgen receptor and the cell surface mucin MUC1, (ii) MES: growth factor receptors [platelet-derived growth factor (PDGF) receptor A; c-Kit], (iii) BLIS: an immunosuppressing molecule (VTCN1), and (iv) BLIA: Stat signal transduction molecules and cytokines.
Purpose: To identify tumor suppressor genes epigenetically silenced by promoter hypermethylation in extranodal natural killer cell lymphoma (NKCL).
Experimental Design: Promoter methylation was analyzed with global and locus-specific methylation assays in NKCL cases and NK cell lines. Gene expression profiles were used to identify genes for which aberrant promoter methylation was associated with transcriptional silencing. Selected DNA methylations were validated by RRBS, pyrosequencing, or q-MSP. Decitabine treatment was performed to evaluate reactivation of methylated genes. The tumor suppressor effect of silenced genes was evaluated functionally by reintroducing them into NK cell lines.
Results: We observed significant promoter hypermethylation in most NKCL samples compared with normal NK cells. Correlation of global promoter methylation with gene expression profiles identified 95 genes with strong evidence for being silenced because of promoter methylation, including BCL2L11 (BIM), DAPK1, PTPN6 (SHP1), TET2, SOCS6, and ASNS. Known tumor suppressor genes were significantly overrepresented in this set of genes. Decitabine treatment of NK cell lines was associated with reexpression of all 10 selected methylated and silenced genes. Ectopic expression of frequently silenced BIM in two BIM-nonexpressing NK cell lines led to increased apoptosis and eventual elimination of BIM-transduced cells. It also sensitized these cell lines to chemotherapy-induced apoptosis. Similarly, reintroduction of SOCS6 significantly inhibited growth in SOCS6-nonexpressing NK cell lines. NK cell lines lacking ASNS expression showed increased sensitivity to treatment with l-asparaginase. Reintroduction of ASNS reduced drug sensitivity.
Purpose: Cancer testis antigens (CTA) are immunotherapeutical targets aberrantly expressed on multiple myeloma cells, especially at later stages, when a concomitant immunoparesis hampers vaccination approaches.
Experimental Design: We assessed the expression of the multiple myeloma antigen HM1.24 (reported present in all malignant plasma cells) and the CTAs MAGE-A2/A3 and NY-ESO-1 (aberrantly expressed in a subset of patients with myeloma), in CD138-purified myeloma cells by qRT-PCR (n = 149). In a next step, we analyzed the antigen-specific T-cell responses against these antigens by IFN EliSpot assay (n = 145) and granzymeB ELISA (n = 62) in relation to stage (tumor load) and expression of the respective antigen.
Results: HM1.24 is expressed in all plasma-cell samples, whereas CTAs are significantly more frequent in later stages. HM1.24-specific T-cell responses, representing the immunologic status, significantly decreased from healthy donors to advanced disease. For the CTAs, the probability of T-cell responses increased in early and advanced stages compared with healthy donors, paralleling increased probability of expression. In advanced stages, T-cell responses decreased because of immunoparesis.
Purpose: Pancreatic cancer frequently causes diabetes. We recently proposed adrenomedullin as a candidate mediator of pancreatic β-cell dysfunction in pancreatic cancer. How pancreatic cancer–derived adrenomedullin reaches β cells remote from the cancer to induce β-cell dysfunction is unknown. We tested a novel hypothesis that pancreatic cancer sheds adrenomedullin-containing exosomes into circulation, which are transported to β cells and impair insulin secretion.
Experimental Methods: We characterized exosomes from conditioned media of pancreatic cancer cell lines (n = 5) and portal/peripheral venous blood of patients with pancreatic cancer (n = 20). Western blot analysis showed the presence of adrenomedullin in pancreatic cancer-exosomes. We determined the effect of adrenomedullin-containing pancreatic cancer exosomes on insulin secretion from INS-1 β cells and human islets, and demonstrated the mechanism of exosome internalization into β cells. We studied the interaction between β-cell adrenomedullin receptors and adrenomedullin present in pancreatic cancer-exosomes. In addition, the effect of adrenomedullin on endoplasmic reticulum (ER) stress response genes and reactive oxygen/nitrogen species generation in β cells was shown.
Results: Exosomes were found to be the predominant extracellular vesicles secreted by pancreatic cancer into culture media and patient plasma. Pancreatic cancer-exosomes contained adrenomedullin and CA19-9, readily entered β cells through caveolin-mediated endocytosis or macropinocytosis, and inhibited insulin secretion. Adrenomedullin in pancreatic cancer exosomes interacted with its receptor on β cells. Adrenomedullin receptor blockade abrogated the inhibitory effect of exosomes on insulin secretion. β cells exposed to adrenomedullin or pancreatic cancer exosomes showed upregulation of ER stress genes and increased reactive oxygen/nitrogen species.
Purpose: Skeletal muscle wasting and weight loss are characteristic features of cancer cachexia and contribute to impaired function, increased morbidity, and poor tolerance of chemotherapy. This study used a novel technique to measure habitual myofibrillar protein synthesis in patients with cancer compared with healthy controls.
Experimental design: An oral heavy water (87.5 g deuterium oxide) tracer was administered as a single dose. Serum samples were taken over the subsequent week followed by a quadriceps muscle biopsy. Deuterium enrichment was measured in body water, serum alanine, and alanine in the myofibrillar component of muscle using gas chromatography–pyrolysis–isotope ratio mass spectrometry and the protein synthesis rate calculated from the rate of tracer incorporation. Net change in muscle mass over the preceding 3 months was calculated from serial CT scans and allowed estimation of protein breakdown.
Results: Seven healthy volunteers, 6 weight-stable, and 7 weight-losing (≥5% weight loss) patients undergoing surgery for upper gastrointestinal cancer were recruited. Serial CT scans were available in 10 patients, who lost skeletal muscle mass preoperatively at a rate of 5.6%/100 days. Myofibrillar protein fractional synthetic rate was 0.058%, 0.061%, and 0.073%/hour in controls, weight-stable, and weight-losing patients, respectively. Weight-losing patients had higher synthetic rates than controls (P = 0.03).
Purpose: Pancreatic ductal adenocarcinoma (PDA) cells are known to produce excessive amounts of reactive oxygen species (ROS), particularly superoxide, which may contribute to the aggressive and refractory nature of this disease. Extracellular superoxide dismutase (EcSOD) is an antioxidant enzyme that catalyzes the dismutation of superoxide in the extracellular environment. This study tests the hypothesis that EcSOD modulates PDA growth and invasion by modifying the redox balance in PDA.
Experimental Design: We evaluated the prognostic significance of EcSOD in a human tissue microarray (TMA) of patients with PDA. EcSOD overexpression was performed in PDA cell lines and animal models of disease. The impact of EcSOD on PDA cell lines was evaluated with Matrigel invasion in combination with a superoxide-specific SOD mimic and a nitric oxide synthase (NOS) inhibitor to determine the mechanism of action of EcSOD in PDA.
Results: Loss of EcSOD expression is a common event in PDA, which correlated with worse disease biology. Overexpression of EcSOD in PDA cell lines resulted in decreased invasiveness that appeared to be related to reactions of superoxide with nitric oxide. Pancreatic cancer xenografts overexpressing EcSOD also demonstrated slower growth and peritoneal metastasis. Overexpression of EcSOD or treatment with a superoxide-specific SOD mimic caused significant decreases in PDA cell invasive capacity.
Purpose:BATF2, a novel IFN-stimulated gene, inhibits tumor cell proliferation, invasion, and migration. The objectives of this study were to determine how BATF2 expression is associated with colorectal cancer progression and patient outcome, to investigate how BATF2 overexpression inhibits hepatocyte growth factor (HGF)/MET signaling, and to elucidate the rationale for combining MET inhibitors with IFN.
Experimental Design: BATF2 expression in colorectal cancer tissues was determined and correlated with colorectal cancer patient prognosis. Cultured colorectal cancer cells were used to investigate the effects of BATF2 overexpression on the malignant phenotype of colorectal cancer cells and HGF/MET signaling. Tumor xenograft models were used to validate the effects of BATF2 on colorectal cancer xenograft growth and assess the efficacy of the combination of MET inhibitors with IFNs in colorectal cancer.
Results: In colorectal cancer tissues, BATF2 was found to be significantly downregulated, and its expression negatively correlated with MET expression. Decreased BATF2 expression was associated with progression and shorter patient survival in colorectal cancer. BATF2 overexpression promoted apoptosis and inhibited proliferation, migration, and invasion in colorectal cancer cells, as well as dramatically blunted tumor xenograft growth. In addition, MET inhibitors in combination with IFNβ produced synergistic cytotoxicity both in vitro and in vivo.
Purpose: Pancreatic ductal adenocarcinoma (PDA) is the fourth leading cause of cancer-related death in the United States, and its incidence is on the rise. Advanced disease is nearly uniformly lethal, emphasizing the need to identify PDA at its earliest stages. To discover early biomarkers of PDA, we evaluated the circulating proteome in murine preinvasive and invasive plasma samples and human prediagnostic and diagnostic samples.
Experimental Design: Using a customized antibody microarray platform containing >4,000 features, we interrogated plasma samples spanning preinvasive and invasive disease from a highly faithful mouse model of PDA. In parallel, we mined prediagnostic plasma from women in the Women's Health Initiative (WHI) who would later succumb to PDA together with matched, cancer-free control samples. Samples collected after an establishing diagnosis of PDA were also interrogated to further validate markers.
Results: We identified ERBB2 and TNC in our cross-species analyses, and multiple antibodies identified ESR1 in prediagnostic plasma from people that succumb to PDA. This 3-marker panel had an AUC of 0.86 (95% confidence interval [CI], 0.76–0.96) for the diagnostic cohort that increased to 0.97 (95% CI, 0.92–1.0) with CA19-9 included. The 3-marker panel also had an AUC of 0.68 (95% CI, 0.58–0.77) for the prediagnostic cohort.