Antisense locked nucleic acids efficiently suppress BCR/ABL and induce cell growth decline and apoptosis in leukemic cells

Abstract

Chronic myeloid leukemia (CML) develops when a hematopoietic stem cell acquires the Philadelphia chromosome carrying the BCR/ABL fusion gene. This gives the transformed cells a proliferative advantage over normal hematopoietic cells. Silencing the BCR/ABL oncogene by treatment with specific drugs remains an important therapeutic goal. In this work, we used locked nucleic acid (LNA) -modified oligonucleotides to silence BCR/ABL and reduce CML cell proliferation, as these oligonucleotides are resistant to nucleases and exhibit an exceptional affinity for cognate RNA. The anti-BCR/ABL oligonucleotides were designed as LNA-DNA gapmers, consisting of end blocks of 3/4 LNA monomers and a central DNA stretch of 13/14 deoxyribonucleotides. The gapmers were complementary to the b2a2 and b3a2 mRNA junctions with which they form hybrid duplexes that have melting temperatures of 79°C and 75°C, respectively, in a 20 mmol/L NaCl-buffered (pH 7.4) solution. Like DNA, the designed LNA-DNA gapmers were capable of activating RNase H and promote cleavage of the target b2a2 and b3a2 BCR/ABL mRNAs. The treatment of CML cells with junction-specific antisense gapmers resulted in a strong and specific reduction of the levels of BCR/ABL transcripts (f20% of control) and protein p210 BCR/ABL

Ion trap collision-induced dissociation of locked nucleic acids

“…The sequence of the mixmer was chosen based on the work of Elmen et al [23]. The sequence of gapmer was chosen based on the work of Rapozzi et al [24]. The LNA samples were used without further purification.…”

“…Selection of the sequence of the LNA gapmer (5=-GGGcttcttccttattgATGG-3=) was inspired by the work of Rapozzi et al [24]. The LNA gapmer can reduce the transcript level of an oncogene leading to chronic myeloid leukemia.…”

“…The other class of LNA-modified oligonucleotide, called LNA gapmer, has a DNA sequence flanked by two short stretches of LNA on both termini. The design of the LNA gapmer sequence allows the RNaseH function to degrade target RNAs [23][24][25][26]. These two designs for effective therapeutic LNA-DNA chimeras hold significant biomedical value in that either the decrease or the increase of small noncoding RNA functions can be achieved.…”

Tumor-specific adenovirus-mediated PUMA gene transfer using the survivin promoter enhances radiosensitivity of breast cancer cells in vitro and in vivo

“…These promoters include some tumor-specific promoters such as hTERT promoter, E2F1 promoter and VEGF promoter [5][6][7]. Moreover, some tissue-specific promoters including alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) promoter have also been used as gene therapy tools [8,9]. However, most of these promoters are limited to specific tumor histologies or weaker transcriptional activity and cannot be used universally and efficiently in tumors of various origins.…”

Antiviral effect of hepatitis B virus S/C gene loci antisense locked nucleic acid on transgenic mice in vivo

“…When oligomers containing it are compared with other oligonucleotides, they have better thermal stability, higher molecular hybridization capability, and stronger resistance to nuclease degradation (Wengel et al, 2003;Inohara et al, 2004;Elmén et al, 2005;Castoldi et al, 2006;Rapozzi et al, 2006;Swayze et al, 2007). Therefore, it has broad application prospects.…”