MicroRNA-1 induces apoptosis by targeting prothymosin alpha in nasopharyngeal carcinoma cells.

BACKGROUND: MiR-1 (microRNA-1) has been used as a positive control in some microRNA experiments. We found that miR-1 transfection of nasopharyngeal carcinoma cells reveals a typical apoptotic process as shown by time-lapse microscopy so we investigated the mechanisms of miR-1 inducing apoptosis. METHODS: To confirm that miR-1 induces apoptosis, we used Annexin V and TUNEL staining and caspase assay. To determine that miR-1 directly targets genes that involve in apoptosis, we analyzed microRNA and pathway databases, and cDNA expression microarrays from miR-1 transfected cells. To demonstrate candidate miR-1 targeted genes, we used qRT-PCR analysis and luciferase reporter vector assays. To assess the miR-1 target gene PTMA (prothymosin alpha, ProTalpha) involves in apoptosis, we used PTMA siRNA to knock down PTMA. RESULTS: Annexin V and TUNEL staining and caspase assay confirm that miR-1 induces nasopharyngeal carcinoma cell apoptosis. MiR-1 transfection of HeLa, Cal-27, KYSE30 and NPC-TW06 cell lines which express low levels of endogenous miR-1 also induces apoptosis. However, miR-1 transfection of cell lines such as SW620, HepG2, HEK-293T, SAS and PC-13 which express high levels of endogenous miR-1 does not result in apoptosis. MiR-1 directly targets PTMA gene. PTMA siRNA and miR-1 accelerate the apoptotic process in cells treated with apoptosis inducers. CONCLUSIONS: The exogenous expression of miR-1 induces apoptosis in a number of cell lines. This is a model of microRNA-induced cell apoptosis. The PTMA is one of miR-1 target genes which involve in miR-1 inducing apoptosis. The apoptotic inducers including actinomycin D, camptothecin and etoposide are also the chemotherapeutic drugs in clinical cancer therapy and PTMA siRNA can accelerate apoptotic progression in cells treated with those apoptosis inducers. Therefore PTMA siRNA may have potential applications as an adjuvant in cancer chemotherapy.

Preclinical verification of the efficacy by targeting peptide-linked liposomal nanoparticles for hepatocellular carcinoma therapy.

The purpose of this study was to investigate the efficacy of targeting peptides chemotherapy to overcome adverse event in the conventional chemotherapy for human hepatocellular carcinoma. Previously we reported several cancer-targeting peptides that bind specifically to cancer cells and their vascular endothelia: L-peptide (anti-cancer cell membrane), RLLDTNRPLLPY; SP-94-peptide (anti-hepatoma cell membrane), SFSHHTPILP; PC5-52-peptide (anti-tumor endothelia), SVSVGMKPSPRP; and control peptide, RLLDTNRGGGGG. In this study, these peptides were linked to liposomal iron oxide nanoparticles to localize the targeted tumor cells and endothelia, and to dextran-coated liposomal doxorubicin (L-D) to treat nonobese diabetic severe combined immunodeficient mice bearing hepatoma xenografts. Our results showed that L-peptide-linked liposomal doxorubicin could inhibit tumor growth with very mild adverse events. Use of the control peptide led to a decrease in the xenograft size but also led to marked apoptotic change in the visceral organ. In conclusion, L-peptide-linked liposomal doxorubicin, SP-94-peptide, and PC5-52-peptide can be used for the treatment of hepatoma xenografts in nonobese diabetic severe combined immunodeficient mice with minimal adverse events.

Nucleolin antisense oligodeoxynucleotides induce apoptosis and may be used as a potential drug for nasopharyngeal carcinoma therapy.

Nucleolin (C23, NCL) mRNA was up-regulated in nasopharyngeal carcinoma (NPC) cells compared to that of normal nasomucosal (NNM) cells using a cDNA microarray approach. The level of nucleolin protein was also up-regulated in 13 NPC cell lines, 30 biopsy specimens and nine other cancer cell lines compared to five NNM cells or normal stromal cells, which were analyzed using immunoblotting or immunohistochemistry. We transfected nucleolin antisense oligodeoxynucleotides (phosphorothioate-modified oligodeoxynucleotides; S-ODNs) into NPC-TW01 cells to knockdown nucleolin expression to evaluate the function of nucleolin in cancer cells. Nucleolin knockdown induced NPC cells but not NNM cells to undergo apoptosis. Furthermore, treatment of NPC-TW01 xenograft tumors with nucleolin antisense oligodeoxynucleotides suppressed the growth of xenograft tumors without obvious side effects. Therefore, we suggest that nucleolin may be a potential cancer therapeutic target and that nucleolin antisense oligodeoxynucleotides may be used as a potential drug for therapy in NPC.