Nanoparticle-delivered VEGF-silencing cassette and suicide gene expression cassettes inhibit colon carcinoma growth in vitro and in vivo

Abstract

The strategies for tumor-specific expression of suicide genes and target tumor angiogenesis have been tested in tumors. However, the anti-tumor efficacy of the combination of these two strategies, particularly, delivering suicide gene and anti-angiogenesis agent by nanoparticles, has not yet been evaluated in colon carcinoma. We constructed a cassette to silence VEGF-A expression and express a fused yCDglyTK gene driven by tumor-specific promoter (shVEGF-CDTK). The DNA carrying shVEGF-CDTK was delivered into colon carcinoma cells by calcium phosphate nanoparticles (CPNPs). Cell proliferation was measured by MTT assay, and apoptosis was detected by flow cytometry. The anti-tumor effect of the combined cassette was tested in xenograft animal model. With 5-fluorocytosine (5-FC), CPNP-delivered shVEGF-CDTK DNA (CPNP-shVEGF-CDTK) showed high expression of fused yCDglyTK gene and effectively silenced VEGF-A expression in vitro and in vivo, which significantly inhibited colon carcinoma cell proliferation and induced apoptosis in vitro. With 5-FC, the systemic delivery of CPNP-shVEGF-CDTK significantly inhibited tumor growth in the colon carcinoma xenograft animal model. The combined cassette is obviously effective in inhibiting tumor cell proliferation and inducing apoptosis in vitro and tumor growth in vivo than the CPNP-shVEGF or CPNP-CDTK alone. The combination of VEGF-A-silencing and tumor-specific expression of suicide gene is an effective strategy for colon carcinoma treatment.

The war against cancer: Suicide gene therapy

“…Mammalian cell vectors. Several mammalian cells exhibiting tumor tropism have been recently suggested as transporters for gene therapy, such as bone marrow stromal cells (MSC) [39] , neural stem cells (NSC) [40] , endothelial progenitor precursor, and blood outgrowth endothelial cells [41] . MSCs are pluripotent progenitor cells, which maintain and regenerate diverse tissues after injury and during chronic inflammation.…”

“…Several biomarkers including CEA, CD44, CD133, and hTERT are investigated on gastrointestinal cancer cells [80] . These biomarkers facilitate early diagnosis for the abovementioned cancer types and are targets for diagnostic molecular imaging and targeted therapies [41,81] . Gynecological and andrological cancers.…”

Frontiers in Suicide Gene Therapy of Cancer

“…Not only they facilitate early diagnosis due to shedding of these biomarkers into the patients' blood, but also they are targets for diagnostic molecular imaging and targeted therapies. The targeted therapies include cancer suicide gene therapies [73][74][75][76][77].…”

Suicide Gene Therapy for Cancer; Old Dog New Tricks

“…The suicide gene therapy has been investigated in several cancer types; a) colon [8,24,25], b) liver [9,26,27], c) lung [28,29], d) medulloblastomas [30], e) neuroendocrine [31], f) spinal cord tumors [32], g) prostate [33], h) breast [34,35], i) bladder [36], j) brain [37], k) gliomas [38-40], l) head and neck [41], m) sarcomas [42], and ovaries [108,111-112]. The suicide gene therapy has been investigated as; a) anti-vascular endothelial treatment [43,44], b) immune stimulation with interleukin- 7 (IL-7) [45] and interleukin-12 (IL-12) [46]. Furthermore, suicide gene therapy has been proven to be more efficient in chemotherapy resistant cancer cell lines [47] and to enhance radiotherapy [48].…”

“…Additional control of micrometastases, through the efficient local control of microenvironment, has also been achieved with suicide gene therapy [49]. Finally, suicide gene therapy has been explored by using the state of the art technology of nanoparticles, either as a mode to passively transport the suicide gene formulation, or as a mode to efficiently display the diffusion of the formulation [43,50,51]. …”