Surfactant like peptides for targeted gene delivery to cancer cells

Surfactant like peptides (SLPs) are a class of amphiphilic peptides widely used for drug delivery and tissue engineering. However, there are very few reports on their application for gene delivery. The current study was aimed at development of two new SLPs, named (IA)₄K and (IG)₄K, for selective delivery of antisense oligodeoxynucleotides (ODNs) and small interfering RNA (siRNA) to cancer cells. The peptides were synthesized by Fmoc solid phase synthesis. Their complexation with nucleic acids was studied by gel electrophoresis and DLS. The transfection efficiency of the peptides was assessed in HCT 116 colorectal cancer cells and human dermal fibroblasts (HDFs) using high content microscopy. The cytotoxicity of the peptides was assessed by standard MTT test. The interaction of the peptides with model membranes was studied using CD spectroscopy. Both SLPs delivered siRNA and ODNs to HCT 116 colorectal cancer cells with high transfection efficiency which was comparable to the commercial lipid-based transfection reagents, but with higher selectivity for HCT 116 compared to HDFs. Moreover, both peptides exhibited very low cytotoxicity even at high concentrations and long exposure time. The current study provides more insights into the structural features of SLPs required for nucleic acid complexation and delivery and can therefore serve as a guide for the rational design of new SLPs for selective gene delivery to cancer cells to minimize the adverse effects in healthy tissues.

[Antisense oligodeoxynucleotides: the certain but limited efficacy and the uncovering mechanisms for the cure of chronic hepatitis B]

Recently, several phase I and phase II clinical trials of antisense oligodeoxynucleotides (ASOs) targeting to the commonly shared conserved sequences of HBV transcripts brought us some promising results. Particularly in the report of phase IIb clinical trial of Bepirovirsen (GSK3228836), approximately 9-10% patients with low baseline serum HBsAg (> 100 IU/ml & < 3 000 IU/ml) achieved functional cure after 24 weeks' of Bepirovirsen treatment. After reviewing the results of other clinical trials, one would be impressed to know that ALG-020572 (Aligos), RO7062931 (Roche) and GSK3389404 (GSK) all failed to sufficiently suppress serum HBsAg expression though the hepatocyte-targeted delivery of these ASOs were enhanced via N-acetyl galactosamine conjugation. Bepirovirsen enabled some patients to achieve sustained disappearance of serum HBsAg. The analysis of its distribution in different tissues of patients after drug administration showed that only a few fractions of ASOs entered liver tissues and far fewer eventually entered hepatocytes. Taking into consideration that only a few hepatocytes could be expected positive for HBsAg staining among these participants with low serum HBsAg level. We suspect that the mechanistic contribution of ASOs declining the serum HBsAg is not only via directly acting on the HBV transcripts in hepatocytes, but also via entering non-parenchymal cells such as Kupffer cells and resulting in stimulation and activation of innate immunity. Eventually the serum HBsAg declines in most participants and even disappears in a small fraction of patients with low baseline HBsAg level, via attack the infected hepatocytes evidenced by the aberrant elevation of ALT. Nevertheless, the functional cure of CHB remains a challenging issue and more efforts are needed.

Tankyrase1 antisense oligodeoxynucleotides suppress the proliferation, migration and invasion through Hippo/YAP pathway in human osteosarcoma cells

Osteosarcoma is the most common malignant tumor of bone with a high potential for metastasis and poor prognosis. This study intends to explore the effect of tankyrase1 (TANK1) in the development of osteosarcoma cells and the underlying mechanism. The osteosarcoma cell line MG-63 cells were cultured and transfected with tankyrase1 antisense oligodeoxynucleotides (TANK1-ASODN). Cell proliferation was detected with CCK-8 and immunofluorescence. Cell migration and invasion were examined by wound healing assay and Transwell assay, respectively. Reverse transcription-quantitative polymerase chain reaction was performed to detect the mRNA level of TANK1 and western blot was conducted to detect relative protein expression during the research. As a result, we demonstrated that TANK1 was upregulated in osteosarcoma. The TANK1-ASODN inhibited MG-63 cell proliferation, migration and invasion. The progress of epithelial-mesenchymal transition (EMT) was also suppressed in TANK1-ASODN transfected MG-63 cells compared to control group. Besides, the TANK1-ASODN activated and modulated the Hippo/YAP signaling which might be the pathway that TANK1 depended on. Overall, our finding supported that TANK1-ASODN slowed down the progress of osteosarcoma by suppressing cell proliferation, migration, invasion and EMT through Hippo/YAP pathway.

Systematic evaluation of oligodeoxynucleotide binding and hybridization to modified multi-walled carbon nanotubes

BACKGROUND

In addition to conventional chemotherapeutics, nucleic acid-based therapeutics like antisense oligodeoxynucleotides (AS-ODN) represent a novel approach for the treatment of bladder cancer (BCa). An efficient delivery of AS-ODN to the urothelium and then into cancer cells might be achieved by the local application of multi-walled carbon nanotubes (MWCNT). In the present study, pristine MWCNT and MWCNT functionalized with hydrophilic moieties were synthesized and then investigated regarding their physicochemical characteristics, dispersibility, biocompatibility, cellular uptake and mucoadhesive properties. Finally, their binding capacity for AS-ODN via hybridization to carrier strand oligodeoxynucleotides (CS-ODN), which were either non-covalently adsorbed or covalently bound to the different MWCNT types, was evaluated.

RESULTS

Pristine MWCNT were successfully functionalized with hydrophilic moieties (MWCNT-OH, -COOH, -NH2, -SH), which led to an improved dispersibility and an enhanced dispersion stability. A viability assay revealed that MWCNT-OH, MWCNT-NH2 and MWCNT-SH were most biocompatible. All MWCNT were internalized by BCa cells, whereupon the highest uptake was observed for MWCNT-OH with 40% of the cells showing an engulfment. Furthermore, all types of MWCNT could adhere to the urothelium of explanted mouse bladders, but the amount of the covered urothelial area was with 2-7% rather low. As indicated by fluorescence measurements, it was possible to attach CS-ODN by adsorption and covalent binding to functionalized MWCNT. Adsorption of CS-ODN to pristine MWCNT, MWCNT-COOH and MWCNT-NH2 as well as covalent coupling to MWCNT-NH2 and MWCNT-SH resulted in the best binding capacity and stability. Subsequently, therapeutic AS-ODN could be hybridized to and reversibly released from the CS-ODN coupled via both strategies to the functionalized MWCNT. The release of AS-ODN at experimental conditions (80 °C, buffer) was most effective from CS-ODN adsorbed to MWCNT-OH and MWCNT-NH2 as well as from CS-ODN covalently attached to MWCNT-COOH, MWCNT-NH2 and MWCNT-SH. Furthermore, we could exemplarily demonstrate that AS-ODN could be released following hybridization to CS-ODN adsorbed to MWCNT-OH at physiological settings (37 °C, urine).

CONCLUSIONS

In conclusion, functionalized MWCNT might be used as nanotransporters in antisense therapy for the local treatment of BCa.

Paeoniflorin inhibits excitatory amino acid agonist-and high-dose morphine-induced nociceptive behavior in mice via modulation of N-methyl-D-aspartate receptors

BACKGROUND

Pain, the most common reasons for physician consultation, is a major symptom in many medical conditions that can significantly interfere with a person's life quality and general functioning. Almost all painkillers have its untoward effects. Therefore, seeking for a safe medication for pain relieve is notable nowadays. Paeonia lactiflora is a well-known traditional Chinese medicine. Paeoniflorin is an active component found in Paeonia lactiflora, which has been reported to inhibit formalin-induced nociceptive behavior in mice. Aims of this present study were to investigate effects of paeoniflorin on excitatory amino acid agonist- or high-dose morphine-induced nociceptive behaviors in mice.

RESULTS

Paeoniflorin (100, 200, 500 nmol, i.c.v.) alone and combined with glutamatergic antagonists (MK-801 14.8 pmol, or NBQX 5 nmol, i.t.) inhibited nociception. Those agents also inhibited the clonic seizure-like excitation induced by high-dose morphine (250 nmol, i.t) in mice. Antisense oligodeoxynucleotides of NMDA receptor subunits NR1, NR2A, NR2B significantly enhanced the inhibition of paeoniflorin on excitatory amino acid-and high-dose morphine-induced nociception. Docking energy data revealed that paeoniflorin had stronger binding activity in NR2A and NR2B than NR2C of NMDA receptors.

CONCLUSIONS

Results of this study indicate that paeoniflorin-induced inhibition of excitatory amino acid agonist- and high-dose morphine-induced nociceptive behaviors might be due to modulation of NMDA receptors, specifically the NR2B subunit.

Differential contribution of Gαi/o subunits in the response to food deprivation

Behavioral responses to food deprivation are a fundamental aspect of nervous system function in all animals. Several signaling molecules in the mammalian brain act through G proteins of the Gi/o family to mediate response to food restriction. The present study examined whether food intake changes under a condition of little stimulation to eat, such as that elicited by 4h of food deprivation, was altered by Gi/o isoform silencing induced by intracerebroventricular (i.c.v.) administration of antisense oligodeoxynucleotides (aODN) against the α subunit of Gi1, Gi2, Gi3, Go1 and Go2. The effect of aODN pretreatments on food intake was evaluated 15, 30, 45, and 60min after food re-administration. Selective effects were noted on food intake with anti-Giα1 (3.12-25nmol), Giα3 (1.56-12.5nmol) and Goα2 (3.12-25nmol) aODN exerting increase in food consumption, while anti-Giα2 (3.12-25nmol) and Goα1 (3.12-25nmol) aODN exerting decrease in food consumption. We observed the effect of the α-subunit silencing on food consumption as soon as 15min after food readministration, that was still significant after 60min. At the highest effective doses, different for each anti-Gαi/o subunit, any treatment did not impair motor coordination, nor modified spontaneous mobility and exploratory activity. These results indicate a relevant distinction between Gαi/o subunits on feeding behavior, and suggest that Gi/o proteins are critical for the integrative modulation of normal feeding behavior. Changes in Gi/o protein activity may be associated with modifications of feeding.

Effect of c-myc antisense oligodeoxynucleotides on proliferation, apoptosis and chemosensitivity of colorectal cancer cell line HT-29

AIM: To investigate the effects of c-myc antisense oligodeoxynucleotides (ASODN) on the proliferation, apoptosis and chemosensitivity to human colorectal cancer cell line HT-29 in vitro.

METHODS: c-myc ASODN and scrambled oligodeoxynueleotide (SODN) were transfected with lipofectamineTM 2000 into human colorectal cancer cell line HT-29. The expression of c-myc mRNA and protein in human colorectal cancer cell line HT-29 was detected by semi quantitive reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively. The effects of the c-myc ASODN on the proliferation and sensitivity to oxaliplatin of HT-29 cell line were studied by MTT assay and flow cytometry (FCM).

RESULTS: The expression of c-myc mRNA level in HT-29 was down-regulated remarkably between the antisense group and control group (0.464 ± 0.029 vs 0.974 ± 0.027, 0.945 ± 0.012, both P < 0.01). Protein expression of c-myc in HT-29 cells was confirmed and it was clear that specific band on PVDF membrane in ASODN group was significantly weakened than those in control groups; MTT and FCM showed the proliferation of HT-29 transfected with c-myc ASODN was retarded obviously in contrast to control groups after 48 hours' transfection (P < 0.05). Compared with the control groups after 72 hours' transfection, the percentage of the survival cells significantly decreased in the presence of both oxaliplatin and c-myc ASODNs (P < 0.05).

CONCLUSION: The c-myc ASODN can inhibit c-myc expression and inhibit the proliferation of colonic cancer HT-29 cells. Combination of c-myc ASODN and oxaliplatin might improve the treatment outcome of colorectal carcinoma. c-myc may be a potential target of gene therapy for human colorectal cancer.

MUC2 antisense oligodeoxynucleotide inhibits proliferation of human gastric carcinoma cells in vitro

AIM: To investigate the inhibitory effect of mucin gene (MUC2) antisense oligodeoxynucleotides (ASODNs) on proliferation of gastric cancer cells SGC7901.

METHODS: Phosphorothioate MUC2 ASODNs were synthesized and then transfected into gastric carcinoma SGC7901 cells mediated by lipofectin. The inhibitory effects on cell proliferation were determined by MTT method, light and electronic microscopy, flow cytometry (FCM) and immunohistochemistry.

RESULTS: MUC2 ASODN at varied concentration significantly inhibited the growth of SGC7901 cells in a dose- and time-dependent manner. The inhibitory peak appeared at 48th hour after transfection, and the inhibition rate reached 55% when the concentration of MUC2 ASODN was 0.5 mol/L. After transfected with MUC2 ASODN, SGC7901 cells decreased in number, volume and karyokinesis, increased in necrosis under light microscopy. And most of the cells arrested in S phase. Swollen mitochondrion, increased liposomes, myelin figures, chromatin margination were found under electronic microscopy. Immunohistochemistry indicated that after transfected with MUC2 ASODN, the expression of MUC2 and nm23 protein were down-regulated, but the expression of p16 protein was up-regulated.

CONCLUSION: MUC2 ASODN transfection can significantly inhibit the proliferation of gastric carcinoma SGC7901 cells.

Antisense Deoxyoligonucleotides Inhibit Activities of Matrix Metalloproteinase-2 in Human Fibrosarcoma HT1080 Cells

PURPOSE

MMP-2, 72 kDa-type IV collagenase, plays a major role in the migration and growth of tumor cells, a process that requires the disintegration of basement membrane. Activation of MMP-2 is correlated with the invasiveness of various tumors. The aim of this study was to determine the sequence-specific phosphorothioated oligodeoxynucleotides (ODNs) inhibiting the translation of MMP-2 mRNA and the subsequent invasiveness of tumor cells.

MATERIALS AND METHODS

Eight types of antisense ODNs were designed and each (8micro gram/ml) were transfected into HT1080 cells. The effects of these antisense ODNs on MMP expression were examined by gelatin zymography, Western blot, Northern blot and matrigel assay.

RESULTS

Antisense-5 (+904~923), antisense-6 (+1274~+1293) and antisense-7 (+1646~+1665) reduced the MMP-2 activity of the culture supernatant in HT1080 fibrosarcoma cells. Treatment with antisense-6 showed inhibition of MMP-2 mRNA and protein, and in vitro invasion in a dose-dependent manner.

CONCLUSION

Antisense-6 might be one of the therapeutic candidates for tumor invasion and metastasis.