Sequential combination therapy with flavopiridol and autocatalytic caspase-3 driven by amplified hTERT promoter synergistically suppresses human ovarian carcinoma growth in vitro and in mice

Targeted co-delivery of protein and drug to a tumor in vivo by sophisticated RGD-modified lipid-calcium carbonate nanoparticles

Synchronized bio-distribution of combination therapies has several merits such as synergistic effects and reduced side-effects. Co-delivery of a protein and small molecule drug using a single nanocarrier is challenging because they possess totally different characteristics. Herein, we report the development of sophisticated nanoparticles composed of lipids, calcium carbonate and RGD peptide ligands for the co-delivery of a protein and small molecule drug combination via a simple preparation method. A 'one-step' ethanol injection method was employed to prepare the highly organized nanoparticles. The nanoparticles exhibited a spherical shape with ca. 130 nm diameter, and clearly had an integrated lipid layer covering the periphery. As a ligand, an RGD-modified lipid was post-inserted into the nanoparticles, which was important to overcome the 'PEG dilemma'. The pH-sensitivity of the targeted nanoparticles contributed to the efficient intracellular co-delivery of a protein and drug combination in Colon26 tumor cells, and noticeably improved their accumulation in the tumor region of xenograft mice. Synchronized bio-distribution of the protein and drug was achieved, which was the foundation for the synergistic effects of the combination. The targeting capability of the nanoparticles along with their pH-sensitive drug release and the synchronized bio-distribution of their cargos led to the significant antitumor activity of the SOD and paclitaxel combination in mice. This study provides novel information for the design and preparation of functionalized nanoparticles for the delivery of a protein/drug combination in vivo.

Therapeutic effect of targeted Fas-expressing adenoviruses method combining γδ T cells in a mouse model of human ovarian carcinoma

The present study aimed to investigate the therapeutic effect and safety of targeted use of Fas-expressing adenoviruses combined with γδ T cell-mediated killing to treat human ovarian cancer xenografts in BALB/c mice. Shuttle plasmids containing control elements of human telomerase reverse transcriptase promoter and two-step transcriptional amplification system were constructed and packaged into adenovirus-5 vectors to generate expression of an exogenous Fas gene. A mouse xenograft model of human ovarian carcinoma was constructed. A total of 35 BALB/c mice were randomly divided into five groups, which were injected with PBS, γδ T cells, Fas-expressing adenoviruses, taxol, or Fas-expressing adenovirus and γδ T cells. The weight and volume of tumors in mice in each group was monitored. Tissue sections of the various tissues of mice in the Fas-expressing adenovirus and γδ T cells group was compared with those in the PBS group to evaluate the safety of Fas-expressing adenovirus and γδ T cells in the treatment of human ovarian cancer xenograft tumors. The results of the present study indicated that mice in all treatment groups were alive at the end of the treatment course. Tumor weight and volume was the highest in the PBS group, followed successively by the adenovirus group, the γδ T cell group, the adenovirus and γδ T cell group, and the taxol group. The weight and volume inhibition rate in adenovirus and γδ T cell group were significantly higher compared with in the PBS group (P<0.05). Pathological observation of tissue samples revealed that none of vital organs in the adenovirus and γδ T cell group developed any evident morphological changes during treatment, when compared with healthy controls. In conclusion, the combined therapy with Fas-expressing adenoviruses and γδ T cells is efficient and safe for the treatment of mouse human ovarian carcinoma xenografts.

Construction of a novel vector expressing Survivin-shRNA and fusion suicide gene yCDglyTK and its application in inhibiting proliferation and migration of colon cancer cells

Despite progress achieved in cancer chemotherapy in recent decades, adverse effects remain a limiting factor for a number of patients with colorectal cancer, suggesting the requirement for novel therapeutic strategies. Gene therapy appears to be a promising strategy for treating cancer. The present study aimed to investigate the anti-tumor effect of a combined gene therapy, using Survivin downregulation by RNAi and a fusion suicide gene yCDglyTK therapy system. A triple-gene vector expressing Survivin-targeted small hairpin RNA (Survivin-shRNA) and fusion suicide gene yCDglyTK was constructed, and administered to HCT116 cells. Survivin expression decreased significantly and yCDglyTK fusion gene expression was confirmed by both reverse transcription-quantitative polymerase chain reaction and western blot analysis. Introduction of Survivin-shRNA into yCDglyTK/prodrug system eradicated colon cancer cells and induced apoptosis more effectively. Furthermore, this therapeutic system is able to inhibit the migration of HCT116 cells. These results indicate that the recombinant plasmid may serve as a novel gene therapy approach to treat colorectal carcinoma.

Targeting Cyclin-Dependent Kinases in Ovarian Cancer

Ovarian cancer is the most common gynecological malignancy in the United States, and prognosis is generally poor because the disease is often diagnosed at an advanced stage. Cyclin-dependent kinases (CDKs) are a family of serine/threonine kinases whose activity is regulated by CDK inhibitors (CKIs) and cyclins. Generally, cyclins and CKIs promote and inhibit CDK activation, respectively. Since cancer commonly involves dysregulation of cell cycle, cyclins and CDKs have been targeted in a variety of tumors using small molecules, peptides, immunotherapy, and CKIs. In this review we discuss the significance of cell cycle dysregulation in ovarian cancer as well as recent advances targeting CDKs in ovarian cancer and potential future directions. Although many of the studies assessing CDK-targeting therapies in ovarian cancer are at an early preclinical stage, there is significant evidence that targeting CDKs, particularly in combination with traditional platinum-based drugs, could have significant efficacy in ovarian cancer. Nevertheless, before these agents can be investigated in humans, additional preclinical development is needed, including using in vivo tumor models and additional studies into their mechanism of action.

Downregulation of SASH1 correlates with tumor progression and poor prognosis in ovarian carcinoma

SAM- and SH3-domain containing 1 (SASH1) is a recently identified tumor suppressor gene that is required in the tumorigenesis of breast and other solid carcinomas. The SASH1 protein contains SH3 and SAM domains, indicating that it may serve an important role in intracellular signal transduction. The purpose of the present study was to investigate the expression of SASH1 in ovarian carcinoma and the correlation between its expression with clinical pathological features and clinical significance, and the effect of SASH1 on cell proliferation, apoptosis and migration of ovarian SKOV3 cells. The human ovarian carcinoma tissues and adjacent normal tissues were collected following surgery. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to detect the expression levels of SASH1 mRNA and protein, respectively. The expression levels of SASH1 mRNA and protein in ovarian carcinoma tissues were significantly lower than that observed in adjacent normal tissues (P<0.05). The expression levels of SASH1 in samples from patients without lymph nodes metastasis and patients with early FIGO stage was lower than those with lymph nodes metastasis and patients with advanced FIGO stage (P<0.05). Flow cytometry analysis and Transwell invasion chamber experiments were used to investigate the effect of SASH1 on the cell proliferation, apoptosis and migration of SKOV3 cells. The recombinant plasmid pcDNA3.1-SASH1 was constructed and transfected into SKOV3 cells. In addition, the SKOV3 cells in the pcDNA3.1-SASH1 group exhibited significantly reduced cell growth, proliferation, and migration ability compared to the empty vector group and normal group (P<0.01). There were a greater number of apoptotic cells in the pcDNA3.1-SASH1 group compared to the empty vector group and normal group (P<0.01). Taken together, these results indicated that SASH1 may be a tumor suppressor gene in ovarian carcinoma, and SASH1 expression inhibited growth, proliferation and migration, and enhanced apoptosis of SKOV3 cells.