Therapeutic effects of survivin dominant negative mutant in a mouse model of prostate cancer.
ABSTRACT Patients with localized prostate cancer can usually achieve initial response to conventional treatment. However, most of them will inevitably progress to advanced disease stage. There is a clear need to develop innovative and effective therapeutics for prostate cancer. Mouse survivin T34A (mS-T34A) is a phosphorylation-defective Thr34 → Ala dominant negative mutant, which represents a potential promising target for cancer gene therapy. This study was designed to determine whether mS-T34A plasmid encapsuled by DOTAP-chol liposome (Lip-mS) has the anti-tumor activity against prostate cancer, if so, to further investigate the possible mechanisms.
In vitro, TRAMP-C1 cells were transfected with Lip-mS and examined for apoptosis by PI staining and flow cytometric analysis. In vivo, subcutaneous prostate cancer models were established in C57BL/6 mice, which were randomly assigned into three groups to receive i.v. administrations of Lip-mS, pVITRO2-null plasmid complexed with DOTAP-chol liposome (Lip-null) or normal saline every 2 days for eight doses. Tumor volume was measured. Tumor tissues were inspected for apoptosis by TUNEL assay. Microvessel density (MVD) was determined by CD31 immunohistochemistry. Alginate-encapsulated tumor cell test was conducted to evaluate the treatment effect on angiogenesis.
Administration of Lip-mS resulted in significant inhibition in the growth of mouse TRAMP-C1 tumors. The anti-tumor response was associated with increased tumor cell apoptosis and decreased microvessel density.
The present study may be of importance in the exploration of the potential application of Lip-mS in the treatment of a broad spectrum of tumors.
SourceAvailable from: Subramanian Krishnakumar[Show abstract] [Hide abstract]
ABSTRACT: The recurrence and metastatic spread of cancer are major drawbacks in cancer treatment. Although chemotherapy is one of the most effective methods for the treatment of metastatic cancers, it is nonspecific and causes significant toxic damage. The development of drug resistance to chemotherapeutic agents through various mechanisms also limits their therapeutic potential. However, as we discuss here, the use of nanodelivery systems that are a combination of diagnostics and therapeutics (theranostics) is as relatively novel concept in the treatment of cancer. Such systems are likely to improve the therapeutic benefits of encapsulated drugs and can transit to the desired site, maintaining their pharmaceutical properties. The specific targeting of malignant cells using multifunctional nanoparticles exploits theranostics as an improved agent for delivering anticancer drugs and as a new solution for overriding drug resistance.Drug discovery today 09/2013; DOI:10.1016/j.drudis.2013.09.009 · 5.96 Impact Factor
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ABSTRACT: LKB1 and FUS1 are two kinds of new tumor suppressor genes as well as early-stage genes in lung cancer. Recent studies showed that LKB1 and FUS1 play important roles in lung carcinogenesis process. We hypothesized that combined gene therapy with LKB1 and FUS1 could inhibit lung cancer growth and development synergistically. In this study, two kinds of tumor suppressor genes, LKB1 and FUS1, were constructed in an eukaryotic coexpression plasmid pVITRO2, and then, we evaluated the synergistic effects of the two genes on anticancer activity and explored the relevant molecular mechanisms. We defined coexpression of LKB1 and FUS1 could synergistically inhibited lung cancer cells growth, invasion and migration and induced the cell apoptosis and arrested cell cycle in vitro. Intratumoral administration of liposomes: pVITRO2-LKB1-FUS1 complex (LPs-pVITRO2-LKB1-FUS1) into subcutaneous lung tumor xenograft resulted in more significant inhibition of tumor growth. Furthermore, intravenous injection of LPs-pVITRO2-LKB1-FUS1 into mice bearing experimental A549 lung metastasis demonstrated synergistic decrease in the number of metastatic tumor nodules. Finally, combined treatment with LKB1 and FUS1 prolonged overall survival in lung tumor-bearing mice. Further study showed that the synergistic anti-lung cancer effects of coexpression of LKB1 and FUS1 might be related to upregulation of p-p53, p-AMPK and downregulation of p-mTOR, p-FAK, MMPs, NEDD9, VEGF/R and PDGF/R. Our results suggest that combined therapy with eukaryotic coexpression plasmid carrying LKB1 and FUS1 genes may be a novel and efficient treatment strategy for human lung cancer.Journal of Cancer Research and Clinical Oncology 03/2014; DOI:10.1007/s00432-014-1607-5 · 3.01 Impact Factor
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ABSTRACT: Abnormal expression of Baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5, also called as survivin), a novel member of the inhibitor of apoptosis protein (IAP) family, has implications in many types of cancer and is considered as a new therapeutic target. We suppose that genetic variant rs9904341 in the 5[prime] UTR region of survivin gene may be associated with the development and progression of prostate cancer (PCa) in Chinese population. TaqMan assay method was used to genotype the polymorphism in the hospital-based case--control analysis of 665 patients with PCa and 710 age-matched cancer-free controls. The genetic associations with the occurrence and progression of PCa were calculated by logistic regression. Our results indicated that compared with GG genotypes, there was a statistically significant increased risk of PCa associated with those with CC genotypes [odds ratios (ORs) = 1.57, 95%confidence intervals (CIs) = 1.17-2.13, P = 0.004]. Moreover, stratification analysis revealed that the association was more pronounced in subgroups of nondrinkers, nonsmokers and those without a family history of cancer (all P < 0.05). In addition, we observed that PSA >= 20 was more frequent in patients carrying GC/CC genotypes than in those with a wild type genotype. The functional survivin rs9904341 genetic variant may have a substantial influence on the PCa susceptibility and evolution.BMC Cancer 07/2013; 13(1):356. DOI:10.1186/1471-2407-13-356 · 3.32 Impact Factor