Previous studies demonstrated that the elevated expression and receptor binding of gastrin-releasing peptide (GRP) in various types of cancer suggest that GRP might be a putative target for immunotherapy in neoplastic diseases. DNA vaccine for hormone/growth factor immune deprivation represents a feasible and attractive approach for cancer treatment; nevertheless, there is still a need to increase the potency of the DNA vaccine. Here, based on six copies of the B cell epitope GRP18–27 in a linear alignment as an immunogen, we designed several anti-GRP DNA vaccines containing different combinations of immunoadjuvants, such as HSP65, tetanus toxoid830–844 (T), pan HLA-DR-binding epitope (PADRE) (P), and mycobacterial HSP70407–426 (M), on a backbone of pCR3.1 plasmid vector with eight 5′-GACGTT-3′ CpG motifs and the VEGF183 signal peptide (VS). The effects of these immunoadjuvants in enhancing GRP-specific humoral immune response were then evaluated by comparing the respective immunogenicity and antitumor effects. Immunization of mice with pCR3.1-VS-HSP65-TP-GRP6-M2 elicited much higher levels of specific anti-GRP antibodies and more effectively inhibited the growth of a GRP-dependent tumor RM-1 in vivo. Interestingly, plasmids encoding for 2HSP70407–426, but not the one with 1 or 3HSP70407–426 showed stronger immune stimulatory potential as well as impressive antitumor activity, suggesting that 2HSP70407–426 is an efficient molecular adjuvant for developing self-epitope vaccines. The highly immunogenic, potent anti-tumorigenic and antiangiogenesis activities of the anti-GRP DNA vaccine offered a novel immunotherapeutic approach in the treatment of GRP-dependent tumors and their complications.
Yong Lu, Didier J L Mekoo, Kedong Ouyang, Xiangbing Hu, Yanhua Liu, Ming Lin, Liang Jin, Rongyue Cao, Taiming Li, Yankai Zhang, Hao Fan and Jingjing Liu
Girish V Shah, Shibu Thomas, Anbalagan Muralidharan, Yong Liu, Paul L Hermonat, Jill Williams and Jaideep Chaudhary
Expression of calcitonin (CT) and its receptor (CTR) is elevated in advanced prostate cancer (PC). Although the significance of CT–CTR axis in PC cell growth, invasion, and epithelial to mesenchymal transition has been established, its role in tumor metastasis has not been examined. To examine the role of CT–CTR axis in tumor metastasis, we employed stable CT–CTR activated and silenced system of three PC cell lines, LNCaP cells that lack endogenous CT, PC-3 cells that lack endogenous CTR, and PC-3M cells that co-express CT and CTR. Enforced expression of CT in LNCaP cells and CTR in PC-3 cells increased their ability to form orthotopic tumors and distant metastases in multiple organs. By contrast, silencing of CT expression in PC-3M cells not only reduced their tumorigenicity, but also completely abrogated their metastatic potential. To investigate the effect of in vivo silencing of CT expression on tumor growth, we employed recombinant adeno-associated virus (rAAV) to deliver anti-CT ribozymes in preexisting tumors of nude mice and large probasin promoter (LPB)-Tag transgenic mice. rAAV-CT− treatment not only abrogated the growth of pre-implanted tumors in nude mice, but also significantly reduced the growth of spontaneous tumors in LPB-Tag mice. Analysis of CT upregulated and silenced PC-3M transcriptomes revealed 105 genes affected by the modulation of CT expression. These CT signature genes generated survival, adhesion, pro-inflammatory, and pro-metastatic pathways. Added together, these data indicate a pivotal role for CT–CTR axis in PC metastasis and may serve as a potential therapeutic target for advanced PC.
Su Liu, Shin-Jen Lin, Gonghui Li, Eungseok Kim, Yei-Tsung Chen, Dong-Rong Yang, M H Eileen Tan, Eu Leong Yong and Chawnshang Chang
Peroxisome proliferator-activated receptor γ (PPARγ, NR1C3) and testicular receptor 4 nuclear receptor (TR4, NR2C2) are two members of the nuclear receptor (NR) superfamily that can be activated by several similar ligands/activators including polyunsaturated fatty acid metabolites, such as 13-hydroxyoctadecadienoic acid and 15-hydroxyeicosatetraenoic acid, as well as some anti-diabetic drugs such as thiazolidinediones (TZDs). However, the consequences of the transactivation of these ligands/activators via these two NRs are different, with at least three distinct phenotypes. First, activation of PPARγ increases insulin sensitivity yet activation of TR4 decreases insulin sensitivity. Second, PPARγ attenuates atherosclerosis but TR4 might increase the risk of atherosclerosis. Third, PPARγ suppresses prostate cancer (PCa) development and TR4 suppresses prostate carcinogenesis yet promotes PCa metastasis. Importantly, the deregulation of either PPARγ or TR4 in PCa alone might then alter the other receptor's influences on PCa progression. Knocking out PPARγ altered the ability of TR4 to promote prostate carcinogenesis and knocking down TR4 also resulted in TZD treatment promoting PCa development, indicating that both PPARγ and TR4 might coordinate with each other to regulate PCa initiation, and the loss of either one of them might switch the other one from a tumor suppressor to a tumor promoter. These results indicate that further and detailed studies of both receptors at the same time in the same cells/organs may help us to better dissect their distinct physiological roles and develop better drug(s) with fewer side effects to battle PPARγ- and TR4-related diseases including tumor and cardiovascular diseases as well as metabolic disorders.
Xiao-Hua Jiang, Jie-Li Lu, Bin Cui, Yong-Ju Zhao, Wei-qing Wang, Jian-Min Liu, Wen-Qiang Fang, Ya-Nan Cao, Yan Ge, Chang-xian Zhang, Huguette Casse, Xiao-Ying Li and Guang Ning
Multiple endocrine neoplasia type 1 (MEN1) is an inherited tumour syndrome characterized by the development of tumours of the parathyroid, anterior pituitary and pancreatic islets, etc. Heterozygous germ line mutations of MEN1 gene are responsible for the onset of MEN1. We investigated the probands and 31 family members from eight unrelated Chinese families associated with MEN1 and identified four novel mutations, namely 373_374ins18, 822delT, 259delT and 1092delC, as well as three previously reported mutations, such as 357_360delCTGT, 427_428delTA and R108X (CGA>TGA) of MEN1 gene. Furthermore, we detected a loss of heterozygosity (LOH) at chromosome 11q in the removed tumours, including gastrinoma, insulinoma and parathyroid adenoma from two probands of MEN1 families. RT-PCR and direct sequencing showed that mutant MEN1 transcripts remained in the MEN1-associated endocrine tumours, whereas normal menin proteins could not be detected in those tumours by either immunohistochemistry or immunoblotting. In conclusion, MEN1 heterozygous mutations are associated with LOH and menin absence, which are present in MEN1-associated endocrine tumours.
Jian Chen, Qingyuan Hu, Hongwei Hou, Shuo Wang, Yunfei Zhang, Yanbo Luo, Huan Chen, Huimin Deng, Hongfu Zhu, Lirong Zhang, Hansong Liu, An Wang and Yong Liu
Thyroid cancer is the most frequent endocrine tumor with a growing incidence worldwide. However, common diagnostic strategy for thyroid cancer classification is hardly to make a proper diagnosis in some cases. To assist classical approach, this study used metabolomics to screen and validate biomarkers from serum and urinary for papillary thyroid cancer (PTC). Overall, 124 untreated PTC, 76 untreated benign thyroid nodule (BTN), and 116 healthy control (HC) were collected in this study. Thirty-six differential metabolites were screened from non-targeted metabolomics with a discovery sample set in comparison with HC and BTN. Serum β-hydroxybutyrate (BHB), docosahexaenoic acid (DHA), 1-methyladenosine (1-MedA), pregnanediol-3-glucuronide (PdG), urinary nicotinic acid mononucleotide (NAM) and xanthosine (Xan) were validated to be significantly differential by targeted metabolomics in validation set. The logistic regression model incorporating six biomarkers had excellent discrimination from receiver-operating characteristics (ROC) analysis, with area under the receiver-operating characteristic curve (AUC) of 0.943 (95% CI 0.902 to 0.983) and 0.952 (95% CI 0.921 to 0.983) for female alone and female + male samples, respectively. The prediction accuracy and false-negative rate in the real setting of one PTC to ten suspicious nodules were 84.7 and 17.7% with the threshold at probablity of 0.5. Results of a double-blind study for PTC and BTN had true positive value of 100% and true negative value of 91.7%. To conclude, BHB, DHA, 1-MedA, PdG, NAM and Xan are suitable biomarkers for PTC, and logistic regression models with the six biomarkers can be potentially used as clinical diagnosis.