Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) overexpression in pancreatic ductal adenocarcinoma correlates with poor survival
© Schaeffer et al; licensee BioMed Central Ltd. 2010
Received: 14 August 2009
Accepted: 23 February 2010
Published: 23 February 2010
Pancreatic ductal adenocarcinoma is a lethal disease with a 5-year survival rate of 4% and typically presents in an advanced stage. In this setting, prognostic markers identifying the more agrressive tumors could aid in managment decisions. Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3, also known as IMP3 or KOC) is an oncofetal RNA-binding protein that regulates targets such as insulin-like growth factor-2 (IGF-2) and ACTB (beta-actin).
We evaluated the expression of IGF2BP3 by immunohistochemistry using a tissue microarray of 127 pancreatic ductal adenocarcinomas with tumor grade 1, 2 and 3 according to WHO criteria, and the prognostic value of IGF2BP3 expression.
IGF2BP3 was found to be selectively overexpressed in pancreatic ductal adenocarcinoma tissues but not in benign pancreatic tissues. Nine (38%) patient samples of tumor grade 1 (n = 24) and 27 (44%) of tumor grade 2 (n = 61) showed expression of IGF2BP3. The highest rate of expression was seen in poorly differentiated specimen (grade 3, n = 42) with 26 (62%) positive samples. Overall survival was found to be significantly shorter in patients with IGF2BP3 expressing tumors (P = 0.024; RR 2.3, 95% CI 1.2-4.8).
Our data suggest that IGF2BP3 overexpression identifies a subset of pancreatic ductal adenocarcinomas with an extremely poor outcome and supports the rationale for developing therapies to target the IGF pathway in this cancer.
Pancreatic ductal adenocarcinoma is a lethal neoplasm with a 5-year survival rate of 4%. Patients typically present with advanced disease. Prognostic markers that identify the more aggressive tumors could aid in management and treatment decisions. The insulin-like growth factor-2 mRNA binding protein family comprises three proteins, IGF2BP1-3, that regulate mRNA transport, translation, and turnover by binding to the coding regions of target mRNAs such as IGF-2 (insulin-like growth factor 2), c-myc, and beta-actin [1–4]. IGF2BP3 was first cloned from a pancreatic tumor cDNA screen and was originally designated as KOC (KH-domain containing protein overexpressed in cancer) . It is known as an oncofetal protein because its expression is highest during embryogenesis [6–10], and is completely silenced in normal adult mouse tissues and is almost so in normal adult human tissues (with fibroblasts, lymphocytes, and the testes being the exceptions) [10, 11]. In a previous study, Mueller-Pillasch et al. provided evidence to suggest that IGF2BP3 may play a role in the differentiation of the human exocrine pancreas during embryogenesis . Although the function of IGF2BP3 in pancreatic ductal adenocarcinoma remains unclear, transgenic overexpression of the protein in mice was reported to induce abnormalities in the exocrine pancreas . In addition, recent reports have demonstrated high levels of IGF2BP3 mRNA transcript and protein in pancreatic cancer tissues but not in benign lesions of the pancreas, chronic pancreatitis and/or normal pancreatic tissues [14, 15]. The expression of IGF2BP3 has also been associated with an unfavorable outcome in renal clear cell carcinoma [16, 17] and more recently, in ovarian clear cell carcinoma . Collectively, these observations led us to postulate that IGF2BP3 expression could be a prognostic indicator for pancreatic ductal adenocarcinoma. The objective of the present study was to determine if expression of IGF2BP3 correlates with patient prognosis.
Patients and tumor specimens
Clinicopathological characteristics by tumor grade
Cohort by Grade
Mean ± SD
60.8 ± 11.5
19 ± 3.6
57.4 ± 12.3
13 ± 6.1
54.3 ± 14.2
7 ± 4.8
57.5 ± 12.6
13 ± 4.8
A tissue microarray (TMA) was constructed using duplicate 0.6-mm cores generated from representative areas of formalin-fixed, paraffin-embedded surgical excision blocks that had been reviewed by at least two pathologists with appropriate subspecialty expertise. Non-neoplastic pancreatic parenchyma (n = 14) served as control tissue.
Treatment and outcome
The majority of patients with ductal adenocarcinoma received surgical treatment with curative intent and did not receive adjuvant chemotherapy. If given, adjuvant chemotherapy was heterogeneous and included either 5FU alone, gemcitabine, or a combination of 5FU with cisplatin. At the time of data collection, generalized province wide treatment guidelines for this particular neoplasm were still in development. The study endpoint was defined as disease specific survival. This information was available for 127 patients. Mean follow-up time was 13 ± 4.8 months (Table 1).
Immunohistochemical staining and scoring
Four-micron sections from the arrays were stained with hematoxylin and eosin to confirm the presence of representative tumor in each core. Sections were stained using a mouse monoclonal antibody against IGF2BP3 (clone 69.1, 1:100 dilution, DAKO, Carpenteria, CA)  and an anti-IGF-2 rabbit polyclonal antibody (1:100 dilution, Abcam, Cambridge, MA) raised against a recombinant human IGF-2 protein. This specific IGF-2 antibody recognizes both the prohormone form of IGF-2 (also named 'big IGF-2, 15 kDa') and the smaller IGF-2 (7.5 kDa). Immunostaining was performed on a Ventana Discovery XT (Ventana, Tucson, AZ) using a standard CC1 heat-induced epitope retrieval protocol (Ventana, Tucson, AZ), and DABMap detection system (Ventana, Tucson, AZ). A cervical carcinoma was used as a positive control with every staining run, and normal pancreatic tissue, which was non-immunoreactive, was used as a negative control. To aid the analysis of the numerous tissue cores stained by immunohistochemistry, digital images were collected using a BLISS instrument (Bacus Laboratories, Lombard, IL). Tissue cores were scored on the basis of thepercentage of positive tumor cells staining above background intensity in a membranous and/or cytoplasmic pattern according to published methodology . In tumor cells, the staining intensity was designated as either non-existent (0), weak (1), moderate (2) or strong (3). The number of cells was scored as either no cells stained (0), <10% (1), 10-50% (2), 50-80% (3) or > 80% (4). The final score was calculated by multiplying these two variables. A score of 0-5 was considered negative (IGF2BP3 and IGF-2 not overexpressed), and a score of 6 and higher was considered positive (overexpression of IGF2BP3 and IGF-2) in accordance with Koebel et al. . Discrepant score results for duplicate cores, when present, were consolidated as the higher interpretable score . Cut-off point for positive cases was any convincing cytoplasmic expression in more than 5% of tumor cells. IGF2BP3 and IGF-2 staining on the tissue microarray was scored by two pathologists (DFS and DRO) blinded to clinical outcome. Discordant results were reviewed by a senior pathologist (DAO) and consensus was reached.
SPSS for Windows (Chicago, IL, USA; Version 14.0) was used for statistical analyses. Survival curves were plotted using the Kaplan-Meier method, with significance assessed using log-rank tests. Cox proportional hazard model was applied to perform multivariate analysis to determine the independent effects of IGF2BP3 expression, age, AJCC stage group, lymphovascular invasion, histological grade and perineural invasion. Statistical significance was declared if the P-value was < 0.05.
IGF2BP3 expression pattern and survival
Multivariable Cox regression analyses
1.921 - 8.963
1.002 - 1.0681
2.21e - 13
4.38e - 06
0.661 - 28.991
0.571 - 10.873
0.096 - 3.462
0.523 - 7.639
1.76e - 09
IGF-2 expression pattern and its correlation with IGF2BP3 expression
Since the most studied IGF2BP3-regulated mRNA transcript is IGF-2, we examined the protein expression of IGF-2 in relation to that of IGF2BP3. IGF-2, in comparison to IGF2BP3, was expressed not only in pancreatic ductal adenocarcinoma, but also in benign pancreatic tissue (Figure 2). However, the staining within benign tissue was exclusively located in acinar cells and, like IGF2BP3, absent in ductal cells, implying IGF2BP3-independent regulation of IGF-2 expression in the acinar cells. If present, the intensity of IGF-2 positive staining was almost 2-fold higher than that of IGF2BP3 and readily observable (Figure 2 and Figure 3b, c). While the expression of IGF-2 was slightly different between tumor grades, this was not statistical significant (P = 0.093; Figure 1). The expression of IGF2BP3 was significantly and positively correlated with that of IGF-2 in tumor cells (P = 0.02). Calculations for disease specific survival for IGF-2 expression alone did not show any difference between the cohorts (data not shown).
Discussion and Conclusions
Although IGF2BP3 is expressed in a variety of malignant neoplasms including pulmonary small cell , endometrial , and cervical carcinomas , the prognostic value has been demonstrated only in renal clear cell carcinomas [16, 17], low-stage urothelial carcinomas of the bladder , and more recently in ovarian clear cell carcinoma . The present study showed for the first time that IGF2BP3 overexpression correlates with poor survival in pancreatic ductal adenocarcinoma. We also demonstrated that the expression of IGF-2 significantly correlates with that of IGF2BP3, which has been previously reported to promote IGF-2 mRNA translation . An attractive feature of IGF2BP3 as a biomarker in pancreatic ductal adenocarcinoma is that its expression is only found in tumor tissue and is absent in normal adult pancreatic ductal tissue. This on-off pattern of expression makes staining interpretation very simple in practice. The expression of IGF2BP3 during embryogenesis  but not in adulthood suggests that IGF2BP3 is epigenetically silenced in adult tissues. In pancreatic ductal adenocarcinoma, re-expression of IGF2BP3 might be the result of promoter hypomethylation. The IGF2BP3 gene is located on chromosome 7p (at location 23,316,354-23,476,520), a region not subject to frequent perturbation in pancreatic ductal adenocarcinoma . It is therefore unlikely that gene amplification is responsible for the observed IGF2BP3 expression in pancreatic ductal adenocarcinoma. We are currently testing the hypothesis that the IGF2BP3 promoter is hypomethylated in pancreatic ductal adenocarcinoma, and that this correlates with expression levels. If this hypothesis holds true, IGF2BP3 could be regarded as a target for re-methylating enzymes.
The mechanisms by which IGF2BP3 and IGF-2 facilitate tumor progression in pancreatic ductal adenocarcinoma remain to be elucidated. However, IGF2BP3-mediated activation of IGF-2 translation has been shown to increase human leukemia cell proliferation . Vikesaa et al.  reported that IGF2BP3 modulates the expression of specific extracellular matrix and cell adhesion proteins (e.g., collagen V α1, ALCAM) and stabilizes CD44 mRNA, thereby promoting invadopodia formation in cervical cancer cells. Moreover, IGF2BP3 has been demonstrated to enhance the motility of human colorectal cancer cells . While less studied than its family member IGF-1, IGF-2 is also known to play a role in cancer progression. Corcoran et al.  recently noted that induction of IGF-2 expression in pre-malignant lesions coincides with progression to advanced medulloblastoma. In addition to its direct effect on tumor cells, IGF-2 was shown to promote tumor angiogenesis and lymphangiogenesis [30, 31]. Decreases in IGF-2 mRNA levels and IGF-2 secretion using growth hormone-releasing hormone antagonists were associated with decreased cancer cell proliferation in vitro  and tumor growth in vivo [33, 34]. Furthermore, IGF-2 deficient tumor cells were shown to be more sensitive to chemotherapy-induced apoptosis . It seems reasonable to speculate that the IGF2BP3/IGF-2 pathway may drive progression in pancreatic ductal adenocarcinoma by similar means, and that therapeutically targeting either or both of these proteins may result in tumor control. These possibilities are being investigated in our laboratory. Interestingly, Wang et al. reported that IGF2BP3 is immunogenic in lung cancer patients, suggesting that it may be a potential target for immunotherapy . In a recent Phase I trial, IGF2BP3 vaccine was shown to be safe and well tolerated .
In summary, this is a retrospective study of a post-surgical, heterogeneously treated cohort of patients with resected pancreatic adenocarcinoma. Thus, prognostic associations, defined as tumor behavior after primary surgery and uninfluenced by different regimens of adjuvant therapy, cannot be assessed. A strength of this study is the relatively large sample size (n = 127) of pancreatic ductal adenocarcinoma. Our data suggest that IGF2BP3 overexpression denotes a subset of pancreatic adenocarcinomas with an extremely poor outcome, and supports the rationale for developing therapies to target the IGF2BP3/IGF-2 pathway in pancreatic ductal adenocarcinoma.
The authors would like to thank Erika Mehl for her technical assistance with immunohistochemistry. This work was funded in part by the Terry Fox Foundation Grant for New Investigators awarded to SSWN through the Canadian Cancer Society Research Institute and the Betty Ergas Pancreatic Cancer Research Fund of the British Columbia Cancer Foundation.
- Nielsen FC, Nielsen J, Christiansen J: A family of IGF-II mRNA binding proteins (IMP) involved in RNA trafficking. Scand J Clin Lab Invest Suppl. 2001, 234: 93-9.View ArticlePubMed
- Liao B, Patel M, Hu Y, Charles S, Herrick DJ, Brewer G: Targeted knockdown of the RNA-binding protein CRD-BP promotes cell proliferation via an insulin-like growth factor II-dependent pathway in human K562 leukemia cells. J Biol Chem. 2004, 279: 48716-24. 10.1074/jbc.M405853200.View ArticlePubMed
- Ioannidis P, Mahaira LG, Perez SA, Gritzapis AD, Sotiropoulou PA, Kavalakis GJ, Antsaklis AI, Baxevanis CN, Papamichail M: CRD-BP/IMP1 expression characterizes cord blood CD34+ stem cells and affects c-myc and IGF-II expression in MCF-7 cancer cells. J Biol Chem. 2005, 280: 20086-93. 10.1074/jbc.M410036200.View ArticlePubMed
- Huttelmaier S, Zenklusen D, Lederer M, Dictenberg J, Lorenz M, Meng X, Bassell GJ, Condeelis J, Singer RH: Spatial regulation of beta-actin translation by Src-dependent phosphorylation of ZBP1. Nature. 2005, 438: 512-5. 10.1038/nature04115.View ArticlePubMed
- Müeller-Pillasch F, Lacher U, Wallrapp C, Micha A, Zimmerhackl F, Hameister H, Varga G, Friess H, Büchler M, Beger HG, Vila MR, Adler G, Gress TM: Cloning of a gene highly overexpressed in cancer coding for a novel KH-domain containing protein. Oncogene. 1997, 14: 2729-33. 10.1038/sj.onc.1201110.View ArticlePubMed
- Yaniv K, Yisraeli JK: The involvement of a conserved family of RNA binding proteins in embryonic development and carcinogenesis. Gene. 2002, 287: 49-54. 10.1016/S0378-1119(01)00866-6.View ArticlePubMed
- Yisraeli JK: VICKZ proteins: a multi-talented family of regulatory RNA-binding proteins. Biol Cell. 2005, 97: 87-96. 10.1042/BC20040151.View ArticlePubMed
- Mori H, Sakakibara S, Imai T, Nakamura Y, Iijima T, Suzuki A, Yuasa Y, Takeda M, Okano H: Expression of mouse igf2 mRNA-binding protein 3 and its implications for the developing central nervous system. J Neurosci Res. 2001, 64: 132-43. 10.1002/jnr.1060.View ArticlePubMed
- Brants JR, Ayoubi TA, Chada K, Marchal K, Ven Van de WJ, Petit MM: Differential regulation of the insulin-like growth factor II mRNA-binding protein genes by architectural transcription factor HMGA2. FEBS Lett. 2004, 569: 277-83. 10.1016/j.febslet.2004.05.075.View ArticlePubMed
- Hammer NA, Hansen TO, Byskov AG, Rajpert-De Meyts E, Grøndahl ML, Bredkjaer HE, Wewer UM, Christiansen J, Nielsen FC: Expression of IGF-II mRNA-binding proteins (IMPs) in gonads and testicular cancer. Reproduction. 2005, 130: 203-12. 10.1530/rep.1.00664.View ArticlePubMed
- Monk D, Bentley L, Beechey C, Hitchins M, Peters J, Preece MA, Stanier P, Moore GE: Characterisation of the growth regulating gene IMP3, a candidate for Silver-Russell syndrome. J Med Genet. 2002, 39: 575-81. 10.1136/jmg.39.8.575.PubMed CentralView ArticlePubMed
- Mueller-Pillasch F, Pohl B, Wilda M, Lacher U, Beil M, Wallrapp C, Hameister H, Knöchel W, Adler G, Gress TM: Expression of the highly conserved RNA binding protein KOC in embryogenesis. Mech Dev. 1999, 88: 95-9. 10.1016/S0925-4773(99)00160-4.View ArticlePubMed
- Wagner M, Kunsch S, Duerschmied D, Beil M, Adler G, Mueller F, Gress TM: Transgenic overexpression of the oncofetal RNA binding protein KOC leads to remodeling of the exocrine pancreas. Gastroenterology. 2003, 124: 1901-14. 10.1016/S0016-5085(03)00402-5.View ArticlePubMed
- Yantiss RK, Cosar E, Fischer AH: Use of IMP3 in identification of carcinoma in fine needle aspiration biopsies of pancreas. Acta Cytol. 2008, 52: 133-8.View ArticlePubMed
- Zhao H, Mandich D, Cartun RW, Ligato S: Expression of K homology domain containing protein overexpressed in cancer in pancreatic FNA for diagnosing adenocarcinoma of pancreas. Diagn Cytopathol. 2007, 35: 700-4. 10.1002/dc.20739.View ArticlePubMed
- Jiang Z, Chu PG, Woda BA, Rock KL, Liu Q, Hsieh CC, Li C, Chen W, Duan HO, McDougal S, Wu CL: Analysis of RNA-binding protein IMP3 to predict metastasis and prognosis of renal-cell carcinoma: a retrospective study. Lancet Oncol. 2006, 7: 556-64. 10.1016/S1470-2045(06)70732-X.View ArticlePubMed
- Hoffmann NE, Sheinin Y, Lohse CM, Parker AS, Leibovich BC, Jiang Z, Kwon ED: External validation of IMP3 expression as an independent prognostic marker for metastatic progression and death for patients with clear cell renal cell carcinoma. Cancer. 2008, 112: 1471-9. 10.1002/cncr.23296.PubMed CentralView ArticlePubMed
- Köbel M, Xu H, Bourne PA, Spaulding BO, Shih IeM, Mao TL, Soslow RA, Ewanowich CA, Kalloger SE, Mehl E, Lee CH, Huntsman D, Gilks CB: IGF2BP3 (IMP3) expression is a marker of unfavorable prognosis in ovarian carcinoma of clear cell subtype. Modern Pathol. 2009, 22 (3): 469-75. 10.1038/modpathol.2008.206.View Article
- Lüttges J, Schemm S, Vogel I, Hedderich J, Kremer B, Klöppel G: The grade of pancreatic ductal adenocarcinomas is an independent prognostic factor and is superior to the immunohistochemical assessment of prolifertion. J Pathol. 2000, 154-161. 10.1002/(SICI)1096-9896(200006)191:2<154::AID-PATH603>3.0.CO;2-C. 191
- Zheng W, Yi X, Fadare O, Liang SX, Martel M, Schwartz PE, Jiang Z: The oncofetal protein IMP3: a novel biomarker for endometrial serous carcinoma. Am J Surg Pathol. 2008, 32: 304-15. 10.1097/PAS.0b013e3181483ff8.View ArticlePubMed
- Köbel M, Weichert W, Crüwell K, Schmitt WD, Lautenschläger C, Hauptmann S: Epithelial hyaluronic acid and CD44v6 are mutually involved in invasion of colorectal adenocarcinomas and linked to patient prognosis. Virchows Arch. 2004, 445: 456-464. 10.1007/s00428-004-1095-0.View ArticlePubMed
- Liu CL, Montgomery KD, Natkunam Y, West RB, Nielsen TO, Cheang MC, Turbin DA, Marinelli RJ, Rijn van de M, Higgins JP: TMA-Combiner, a simple software tool to permit analysis of replicate cores on tissue microarrays. Mod Pathol. 2005, 18: 1641-1648.PubMed
- Xu H, Bourne PA, Spaulding BO, Wang HL: High-grade neuroendocrine carcinomas of the lung express K homology domain containing protein overexpressed in cancer but carcinoid tumors do not. Hum Pathol. 2007, 38: 555-63. 10.1016/j.humpath.2006.11.011.View ArticlePubMed
- Li C, Rock KL, Woda BA, Jiang Z, Fraire AE, Dresser K: IMP3 is a novel biomarker for adenocarcinoma in situ of the uterine cervix: an immunohistochemical study in comparison with p16(INK4a) expression. Mod Pathol. 2007, 20: 242-7. 10.1038/modpathol.3800735.View ArticlePubMed
- Sitnikova L, Mendese G, Liu Q, Woda BA, Lu D, Dresser K, Mohanty S, Rock KL, Jiang Z: IMP3 predicts aggressive superficial urothelial carcinoma of the bladder. Clin Cancer Res. 2008, 14: 1701-6. 10.1158/1078-0432.CCR-07-2039.View ArticlePubMed
- Shiraishi K, Okita K, Kusano N, Harada T, Kondoh S, Okita S, Ryozawa S, Ohmura R, Noguchi T, Iida Y, Akiyama T, Oga A, Fukumoto Y, Furuya T, Kawauchi S, Sasaki KA: comparison of DNA copy number changes detected by comparative genomic hybridization in malignancies of the liver, biliary tract and pancreas. Oncology. 2001, 60 (2): 151-61. 10.1159/000055313.View ArticlePubMed
- Vikesaa J, Hansen TV, Jønson L, Borup R, Wewer UM, Christiansen J, Nielsen FC: RNA-binding IMPs promote cell adhesion and invadopodia formation. EMBO J. 2006, 25: 1456-68. 10.1038/sj.emboj.7601039.PubMed CentralView ArticlePubMed
- Vainer G, Vainer-Mosse E, Pikarsky A, Shenoy SM, Oberman F, Yeffet A, Singer RH, Pikarsky E, Yisraeli JK: A role for VICKZ proteins in the progression of colorectal carcinomas: regulating lamellipodia formation. J Pathol. 2008, 215: 445-56. 10.1002/path.2376.PubMed CentralView ArticlePubMed
- Corcoran RB, Bachar Raveh T, Barakat MT, Lee EY, Scott MP: Insulin-like growth factor 2 is required for progression to advanced medulloblastoma in patched 1 heterozygous mice. Cancer Res. 2008, 68: 8788-95. 10.1158/0008-5472.CAN-08-2135.PubMed CentralView ArticlePubMed
- Kim KW, Bae SK, Lee OH, Bae MH, Lee MJ, Park BC: Insulin-like growth factor II induced by hypoxia may contribute to angiogenesis of human hepatocellular carcinoma. Cancer Res. 1998, 58: 348-51.PubMed
- Björndahl M, Cao R, Nissen LJ, Clasper S, Johnson LA, Xue Y, Zhou Z, Jackson D, Hansen AJ, Cao Y: Insulin-like growth factors 1 and 2 induce lymphangiogenesis in vivo. Proc Natl Acad Sci USA. 2005, 102: 15593-8. 10.1073/pnas.0507865102.PubMed CentralView ArticlePubMed
- Csernus VJ, Schally AV, Kiaris H, Armatis P: Inhibition of growth, production of insulin-like growth factor-II (IGF-II), and expression of IGF-II mRNA of human cancer cell lines by antagonistic analogs of growth hormone-releasing hormone in vitro. Proc Natl Acad Sci USA. 1999, 96: 3098-103. 10.1073/pnas.96.6.3098.PubMed CentralView ArticlePubMed
- Jungwirth A, Schally AV, Pinski J, Groot K, Armatis P, Halmos G: Growth hormone-releasing hormone antagonist MZ-4-71 inhibits in vivo proliferation of Caki-I renal adenocarcinoma. Proc Natl Acad Sci USA. 1997, 94: 5810-3. 10.1073/pnas.94.11.5810.PubMed CentralView ArticlePubMed
- Lamharzi N, Schally AV, Koppán M, Groot K: Growth hormone-releasing hormone antagonist MZ-5-156 inhibits growth of DU-145 human androgen-independent prostate carcinoma in nude mice and suppresses the levels and mRNA expression of insulin-like growth factor II in tumors. Proc Natl Acad Sci USA. 1998, 95: 8864-8. 10.1073/pnas.95.15.8864.PubMed CentralView ArticlePubMed
- Lamm GM, Christofori G: Impairment of survival factor function potentiates chemotherapy induced apoptosis in tumor cells. Cancer Res. 1998, 58: 8017-
- Wang T, Fan L, Watanabe Y, McNeill PD, Moulton GG, Bangur C, Fanger GR, Okada M, Inoue Y, Persing DH, Reed SG: L523S, an RNA-binding protein as a potential therapeutic target for lung cancer. Br J Cancer. 2003, 88: 887-94. 10.1038/sj.bjc.6600806.PubMed CentralView ArticlePubMed
- Nemunaitis J, Meyers T, Senzer N, Cunningham C, West H, Vallieres E, Anthony S, Vukelja S, Berman B, Tully H, Pappen B, Sarmiento S, Arzaga R, Duniho S, Engardt S, Meagher M, Cheever MA: Phase I Trial of sequential administration of recombinant DNA and adenovirus expression L523S protein in early stage non-small-cell lungcancer. Mol Ther. 2006, 13: 1185-91. 10.1016/j.ymthe.2006.01.013.View ArticlePubMed
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2407/10/59/prepub
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