A new application of plant virus nanoparticles as drug delivery in breast cancer

Nanoparticles based on non-pathogenic viruses have opened up a novel sector in nanotechnology. Viral nanoparticles based on plant viruses have clear advantages over any synthetic nanoparticles as they are biocompatible and biodegradable self-assembled and can be produced inexpensively on a large scale. From several such under-development platforms, only a few have been characterized in the target-specific drugs into the cells. Potato virus X is presented as a carrier of the chemotherapeutic drug Herceptin that is currently used as a targeted therapy in (HER2+) breast cancer patients. Here, we used nanoparticles formed from the potato virus X to conjugate the Herceptin (Trastuzumab) monoclonal antibody as a new option in specific targeting of breast cancer. Bioconjugation was performed by EDC/sulfo-N-hydroxysuccinimide (sulfo-NHS) in a two-step protocol. Then, the efficiency of conjugation was investigated by different methods, including sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blot, ELISA, Zetasizer, and transmission electron microscopy. SDS-PAGE and Western blot analysis confirmed an 82-kDa protein band that resulted from conjugation of potato virus X (PVX) coat protein (27 kDa) to heavy chain of Herceptin (55 kDa). Zeta potential values for conjugated particles, PVX, and HER were -7.05, -21.4, and -1.48, respectively. We investigated the efficiency of PVX-Herceptin to induce SK-OV-3 and SK-BR-3 cells (HER2 positive cell lines) apoptosis. We therefore counted cells and measured apoptosis by flow cytometry assay, then compared with Herceptin alone. Based on our data, we confirmed the conjugation of PVX and Herceptin. This study suggests that the PVX-Herceptin conjugates enable Herceptin to become more potential therapeutic tools.

MicroRNA-148b and microRNA-152 reactivate tumor suppressor genes through suppression of DNA methyltransferase-1 gene in pancreatic cancer cell lines

Overexpression of DNA methyltransferase 1 (DNMT-1) is observed mostly in pancreatic cancer and it can cause tumor suppressor genes silencing in this disease. Recent studies suggest that abnormal expressions of microRNAs (miRs) are involved in pathogenesis of different types of human cancers including pancreatic cancer. In this study we aimed to investigate the effect of miR-148b and -152 on reverting the tumorigenic phenotype of pancreatic cancer cell lines. In order to investigate whether miR-148b and -152 are involved in the regulation of DNMT-1, luciferase reporter assay was used and confirmed that the DNMT-1 mRNA could be a target for miR-148b and miR-152. Furthermore, overexpression of miR-148b and -152 in pancreatic cancer cell lines (MIA PaCa-2 and AsPC-1) decreased DNMT-1 expression (53% and 59% respectively), returned DNA methylation to normal patterns and induced re-expression of tumor suppressor genes, like BNIP3 (4.7- and 3.8-fold) and SPARC (5.3- and 2.9-fold) for miR-148b and -152 respectively. Moreover, the introduced miR-148b and -152 could inhibit the proliferation of MIA PaCa-2 (35% and 37% respectively) and AsPC-1 (39% and 40% respectively) cell lines. The apoptosis rates of MIA PaCa-1 after treatment with miR-148b and -152 were 10% and 8% respectively; while these rates in AsPC-1 were 16% and 11% respectively. Conclusively these findings mean that miRs that are targeting DNMT-1 and modifying methylation status of tumor suppressor genes such as BNIP3 and SPARC can be applied in killing the pancreatic cancer cells and decreasing the tumorigenicity of these cells.

Comparisons between RT-PCR, real-time PCR, and in vitro globin chain synthesis by α/β ratio calculation for diagnosis of α- from β-thalassemia carriers

BACKGROUND

Thalassemia, which may be due to point mutations, translocations, and deletions involving the α or βglobin gene, is the most prevalent single gene disorder in Iran.This study aims to calculate the α/β ratio in normal cases, α- and β-thalassemia carriers by RT-PCR, real-time PCR, and in vitro globin chain synthesis (GCS) in order to establish the most accurate technique to distinguish between α- and β-thalassemia carriers in suspicious cases.

METHODS

The α/β ratios were calculated in all samples by RT-PCR, real-time RT-PCR, and in vitro GCS.

RESULTS

Using RT-PCR, the ratios were 1.09 ± 0.07 in normal samples, 1.2 ± 0.17 in β-thalassemia, 1.08 ± 0.19 in mild α-thalassemia, and 0.96 ± 0.19 in severe α-thalassemia carriers. In real-time RT-PCR, the ratios were 2.21 ± 1.36 in normal samples, 5.12 ± 1.83 in β-thalassemia, 2.88 ± 0.81 in mild α-thalassemia, and 1.18 ± 0.52 in severe α-thalassemia carriers. With GCS, the ratios were 1.03 ± 0.1 in normal samples, 1.9 ± 0.37 in β-thalassemia, 0.8 ± 0.13 in mild α-thalassemia, and 0.59 ± 0.12 in severe α-thalassemia carriers.

CONCLUSION

To determine the most accurate technique, we statistically analyzed the α/β ratios obtained from the three standard methods. The ratio obtained by GCS and real-time PCR were helpful in distinguishing between α and β carriers in suspicious patients in whom the mutation detection was limited and the risk for offspring was not clear. The use of this technique is more obvious when time is restricted (i.e. during the pregnancy period).

Rapid low-cost detection of hepatitis C virus RNA in HCV-infected patients by real-time RT-PCR using SYBR Green I

BACKGROUND

We intend to design and validate a low-cost assay for the detection of hepatitis C virus (HCV) RNA using rapid-cycle RT-PCR. The procedure is performed in a closed system with little risk of contamination allowing PCR and product identification to be performed within one or two hours.

METHODS

A SYBR Green-based real-time RT-PCR for rapid detection of HCV. Amplicon synthesis was monitored continuously by SYBR Green I, which binds to double stranded DNA during PCR. The PCR products were identified by melting curve analysis. Standard sera with known concentrations of HCV RNA and 150 clinical samples were used to validate our assay.

RESULTS

The minimum detection level of our assay was less than 50 IU/mL. The results on 100 plasma samples were comparable with commercial assays.

CONCLUSIONS

This method is useful for rapid qualitative detection of HCV infection and particularly suitable for routine diagnostic applications.