Downregulation of survivin expression exerts antitumoral effects on mouse breast cancer cells in vitro and in vivo

Anti-EpCAM functionalized graphene oxide vector for tumor targeted siRNA delivery and cancer therapy

Graphene oxide (GO) has emerged as a potential drug delivery vector. For siRNA delivery, GO should be modified to endow it with gene delivery ability and targeting effect. However, the cationic materials used previously usually had greater toxicity. In this study, GO was modified with a non-toxicity cationic material (chitosan) and a tumor specific monoclonal antibody (anti-EpCAM) for the delivery of survivin-siRNA (GCE/siRNA). And the vector (GCE) prepared was proved with excellent biosafety and tumor targeting effect. The GCE exhibited superior performance in loading siRNA, maintained stability in different solutions and showed excellent protection effect for survivin-siRNA in vitro. The gene silencing results in vitro showed that the mRNA level and protein level were down-regulated by 48.24% ± 2.50% and 44.12% ± 3.03%, respectively, which was equal with positive control (P > 0.05). It was also demonstrated that GCE/siRNA had a strong antitumor effect in vitro, which was attributed to the efficient antiproliferation, and migration and invasion inhibition effect of GCE/siRNA. The results in vivo indicated that GCE could accumulate siRNA in tumor tissues. The tumor inhibition rate of GCE/siRNA 54.74% ± 5.51% was significantly higher than control 4.87% ± 8.49%. Moreover, GCE/siRNA showed no toxicity for blood and main organs, suggesting that it is a biosafety carrier for gene delivery. Taken together, this study provides a novel design strategy for gene delivery system and siRNA formulation.

PKM2-c-Myc-Survivin Cascade Regulates the Cell Proliferation, Migration, and Tamoxifen Resistance in Breast Cancer

The M2 isoform of pyruvate kinase (PKM2), as a key glycolytic enzyme, plays important roles in tumorigenesis and chemotherapeutic drug resistance. However, the intricate mechanism of PKM2 as a protein kinase regulating breast cancer progression and tamoxifen resistance needs to be further clarified. Here, we reported that PKM2 controls the expression of survivin by phosphorylating c-Myc at Ser-62. Functionally, PKM2 knockdown suppressed breast cancer cell proliferation and migration, which could be rescued by overexpression of survivin. Interestingly, we found that the level of PKM2 expression was upregulated in the tamoxifen resistant breast cancer cells MCF-7/TAMR, and knockdown of PKM2 sensitized the cells to 4-hydroxytamoxifen (4OH-T). In addition, the elevated level of PKM2 correlates with poor relapse-free survival in breast cancer patients treated with tamoxifen. Overall, our findings demonstrated that PKM2–c-Myc–survivin cascade regulated the proliferation, migration and tamoxifen resistance of breast cancer cells, suggesting that PKM2 represents a novel prognostic marker and an attractive target for breast cancer therapeutics, and that PKM2 inhibitor combined with tamoxifen may be a promising strategy to reverse tamoxifen resistance in breast cancer patients.

Biochemical and biophysical study of chemopreventive and chemotherapeutic anti-tumor potential of some Egyptian plant extracts

the present study the was done to evaluate chemopreventive and chemotherapeutic anti-tumor potential of some Egyptian plant extract (moringa, graviola, ginger garden cress and artemisinin) against 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinogenesis in Swiss albino mice. chemopreventive and chemotherapeutic evaluation was assessed by monitoring the tumor incidence and tumor volume as well as by analyzing the status of (a) biochemical markers (maspin, survivin, livin, caveolin-1, osteopontin and Fucosyltransferase 4 gene expressions), oxidative stress related profile including; total antioxidant capacity (TAC), glutathione reductase (GR) activity, glutathione-s-transferase (GST) activity assay, superoxide dismutase (SOD) activity, catalase (CAT) activity and lipid peroxidation (MDA), renal and hepatic toxicity markers (urea, creatinine, alanine transaminase (alt) activity, aspartate aminotransferase (ast) activity, alkaline phosphatase (ALP) Activity and γ-Glutamyltransferase (GGT) activity also study of (b) biophysical markers (trace and heavy metals (lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni), iron (Fe), selenium (Se), copper (Cu) and zinc (Zn)), dielectric properties and body water distribution) finally (c) histopathological examination oral administration of increasing dose of moringa, graviola, ginger garden cress and artemisinin extracts, respectively significantly prevented the tumor incidence and tumor volume as well as brought back the status of the above mentioned biochemical and biophysical variables. Histopathological changes also confirmed the formation of tumor tubules and neovascularization after the treatment. Overall, these results suggest that treatment with moringa, graviola, ginger garden cress and artemisinin extracts provided antioxidant defense with strong chemopreventive and chemotherapeutic activity against DMBA-induced mammary tumors.

Co-Delivery of Eugenol and Dacarbazine by Hyaluronic Acid-Coated Liposomes for Targeted Inhibition of Survivin in Treatment of Resistant Metastatic Melanoma

While melanoma remains a challenge for oncologists, possibilities are being continuously explored to fight resistant metastatic melanoma more effectively. Eugenol is reported to inhibit survivin protein in breast cancer cells. Survivin is also overexpressed by melanoma cells, and is known to impart resistance to them against chemotherapy-induced apoptosis. To be able to fight resistant melanoma, we formulated hyaluronic acid (HA)-coated liposomes loaded with an effective combination of anti-melanoma agents (Dacarbazine and Eugenol), using a solvent injection method. Quality-by-Design (QbD) was applied to optimize and obtain a final formulation with the desired quality attributes, and within an acceptable size range. The optimized formulation was then subjected to performance analysis in cell lines. Coated-Dacarbazine Eugenol Liposomes were found to possess 95.08% cytotoxicity at a dacarbazine concentration of 0.5 µg/mL, while Dacarbazine Solution showed only 10.20% cytotoxicity at the same concentration. The number of late apoptotic cells was also found to be much higher (45.16% vs. 8.43%). Furthermore, migration assay and proliferation study also revealed significantly higher inhibition of cell migration and proliferation by Coated-Dacarbazine Eugenol Liposomes, signifying its potential against metastasis. Thus, surface-functionalized dacarbazine- and eugenol-loaded liposomes hold great promise against resistant and aggressive metastatic melanoma, with much less unwanted cytotoxicity and reduced doses of the chemotherapeutic agent.

Growth inhibition and chemo-radiosensitization of esophageal squamous cell carcinoma by survivin-shRNA lentivirus transfection

Esophageal cancer is one of the most common types of cancer worldwide, and it has a poor prognosis. Chemo-radiotherapy resistance and cancer relapse are among the most difficult issues in its treatment. Identifying the underlying molecular mechanisms is critical for developing novel therapies. Survivin has been previously suggested to be overexpressed in esophageal cancer cells. The present study identified that down-regulation of survivin sensitized esophageal cancer cells to chemo-radiotherapy. Consistent with previous studies, the present study indicated that survivin was overexpressed in 4 esophageal squamous carcinoma cell lines. Short hairpin RNA delivered by lentivirus successfully knocked down survivin in these cancer cell lines. Consequently, down-regulation of survivin impaired their colony-forming, migratory and invasive capabilities, while the overexpression of survivin in normal human esophagus epithelial cells improved their resistance to cisplatin, paclitaxel and radiation. Survivin knockdown induced apoptosis in esophageal cancer KYSE-150 and ECA-109 cell lines when exposed to the aforementioned chemo-radiotherapy treatments. These results indicate that survivin expression sustains growth in esophageal cancer cells, and confers resistance to chemo-radiotherapy. Targeted survivin ablation may be a promising strategy against esophageal tumor relapse and chemo-radioresistance.

In vivo antitumor activity of liposome‑plasmid DNA encoding mutant survivin‑T34A in cervical cancer

The aim of the present study was to investigate the influence of liposome-plasmid encoding mutant survivin-T34A (PST34A) on tumor growth in cervical cancer in vivo. Liposome-plasmid DNA encoding mutant survivin-T34A was constructed and administered via an intraperitoneal injection in mice inoculated with cervical cancer cells. Following the establishment of the tumor model, the animals were randomly divided into four groups: i) The normal saline group (NS; 100 µl sterile saline once/3 days for 15 days); ii) the 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) control (100 µg DOTAP once/3 days for 15 days); iii) the plasmid PST34A (10 µg PST34A once/3 days for 15 days); and iv) the PST34A+DOTAP (10 µg PST34A+100 µg DOTAP once/3 days for 15 days). All treatments were administered via intraperitoneal injections. Tumor growth was evaluated following injection with liposome-plasmid DNA encoding mutant survivin-T34A. Apoptosis of cells in ascitic fluid was detected by flow cytometry. The expression of Ki67 and CD34 was detected by immunohistochemical staining. Administration of liposome-plasmid complexes encoding mutant survivin-T34A inhibited tumor growth, reduced the number of tumor nodules and the volume of ascitic fluid, and decreased abdomen circumference and tumor weight. The number of Ki67-positive cells was markedly reduced in the DOTAP+PST34A group compared with the remaining groups. Flow cytometry demonstrated that the number of cells in the sub-G1 phase (apoptosis) increased in the DOTAP+PST34A group compared with all other groups. In addition, tumors in the DOTAP+PST34A group exhibited lower microvessel density compared with all other groups. In the present study, liposome-plasmid DNA encoding mutant survivin-T34A could inhibit tumor growth of cervical cancer. This inhibition may be associated with an increase in the apoptosis rate of tumor cells and a reduction in angiogenesis.

Elucidating respective functions of two domains BIR and C-helix of human IAP survivin for precise targeted regulating mitotic cycle, apoptosis and autophagy of cancer cells

Survivin was the smallest member of the IAP family, which was over expressed in many different cancers, and considered to be a promising hot target for cancer therapy, and our previous study demonstrated that multiple dominant negative mutants from full-length survivin could have many complex effects on cancer cells, such as cell cycle, apoptosis, and autophagy. But it was not yet known what role the two main domains played in those functions, which would be very important for the design of targeted anticancer drugs and for the interpretation of their molecular mechanisms. In this study, based on preparation the two parts (BIR domain and CC domain) of survivin by genetic engineering and cell characterization assay, we discovered that BIR (T34A)-domain peptide could inhibit Bcap-37 cells growth in a dose- and time-dependent manner, increase the proportion of G2/M phase, and induce caspase-dependent apoptosis via the mitochondrial pathway. While CC (T117A)-domain peptide increased the proportion of S-phase cells and increased the level of the autophagy marker protein LC3B significantly. These further experiments confirmed that TAT-BIR (T34A) peptide could be used to inhibit cell proliferation, promote apoptosis, and block mitosis, and TAT-CC (T117A) peptide showed mainly to promote autophagy, process of DNA replication, and mitosis to breast cancer cells. This research will lay the foundation for interpreting the multifunction mechanism of survivin in cell fates, further make senses in developing the anticancer drugs targeting it precisely and efficiently.

Knockdown of PARP6 or survivin promotes cell apoptosis and inhibits cell invasion of colorectal adenocarcinoma cells

Colorectal adenocarcinoma is the third most common cancer worldwide. PARP6, a novel member of the poly(ADP-ribose) polymerases (PARPs) and survivin, a member of the family of inhibitor of apoptosis (IAP) proteins are associated with a poor prognosis in various types of cancers. However, limited evidence exists regarding the interaction between PARP6 and survivin in colorectal adenocarcinoma. In the present study, we used the paired samples of 20 patients with colorectal adenocarcinoma to detect the expression of PARP6 and survivin in both tumor and adjacent normal colorectal mucosa. Their interaction and roles in cell viability, cell cycle, cell apoptosis and cell invasion were further investigated. Our results showed that both PARP6 and survivin exhibited higher expression in colorectal adenocarcinoma tissues and SW620 cells when compared with levels in adjacent non-tumor tissues and a normal colon cell line FHC. Co-immunoprecipitation assay showed that a significant correlation existed between PARP6 and survivin. We also showed that sole treatment of PARP6 siRNA or survivin siRNA partially inhibited the cell survival and invasion, induced cell G0/G1 arrest, and cell apoptosis at the early and late stages. The combined treatment of PARP6 siRNA and survivin siRNA suppressed the cell survival and cell invasion, further induced cell cycle phase G0/G1 arrest, and cell apoptosis at the early and late stages. Taken together, knockdown of PARP6 or survivin promotes cell apoptosis and inhibits the cell invasion of colorectal adenocarcinoma cells. A significant correlation exists between PARP6 and survivin, and both are promising targets for the development of new strategies for the diagnosis and treatment of advanced or metastatic colorectal adenocarcinoma.

Biodegradable nanoparticles as siRNA carriers for in vivo gene silencing and pancreatic cancer therapy

Biodegradable charged polyester-based vectors (BCPVs) were utilized for efficiently delivering mutatedK-Ras-targeting siRNA and successfully inhibiting tumor growth in a pancreatic xenograft modelin vivo.